Foreign body granulomas after all injectable dermal fillers: part 2. Treatment options. Lemperle G, Gauthier-Hazan N. Plast Reconstr Surg. 2009 Jun;123(6):1864-73.
SUMMARY: Foreign body granulomas occur at certain rates with all injectable
dermal fillers. They have to be distinguished from early implant nodules, which
usually appear 2 to 4 weeks after injection. In general, foreign body granulomas
appear after a latent period of several months at all injected sites at the same
time. If diagnosed early and treated correctly, they can be diminished within a
few weeks. The treatment of choice of this hyperactive granulation tissue is the
intralesional injection of corticosteroid crystals (triamcinolone, betamethasone,
or prednisolone), which may be repeated in 4-week cycles until the right dose is
found. To lower the risk of skin atrophy, corticosteroids can be combined with
antimitotic drugs such as 5-fluorouracil and pulsed lasers. Because foreign body
granulomas grow fingerlike into the surrounding tissue, surgical excision should
be the last option. Surgery or drainage is indicated to treat normal lumps and
cystic foreign body granulomas with little tissue ingrowth. In most patients, a
foreign body granuloma is a single event during a lifetime, often triggered by a
systemic bacterial infection.
Endovenous laser treatment for uncomplicated varicose veins. Darwood RJ, Gough MJ. Phlebology. 2009;24 Suppl 1:50-61.
OBJECTIVE: Endovenous laser ablation (EVLA) of incompetent truncal veins has been
proposed as a minimally invasive alternative to conventional surgery for varicose
veins. Various strategies have been proposed for successful treatment and this
study reviews the evidence for these. METHOD: A Medline and ‘controlled trials
online database’ search was performed to identify original articles and
randomized controlled trials (RCTs) reporting outcomes for EVLA. Information on
patient selection, equipment, technique and outcomes were recorded. RESULTS:
Ninety-eight original studies, including five RCTs, were identified. RCT data
indicate short-term outcomes (abolition of reflux, improvement in quality of life
[QOL], patient satisfaction) were equivalent to those for surgery. Long-term
follow-up is not available. A further RCT showed superior outcomes for ablation
commencing at the lowest point of superficial venous reflux rather than at an
arbitrary point (fewer residual varicosities, greater improvement in QOL).
Non-randomized series suggest that laser energy of >60 J/cm results in reliable
truncal vein occlusion and that longer wavelength lasers may be associated with
less post-treatment discomfort. CONCLUSION: In the short-term EVLA is a safe and
effective treatment for patients with varicose veins. Long-term follow-up is
[Esthetic and corrective dermatology: clinical applications and social role] [Article in French] Noël B. Rev Med Suisse. 2009 Apr 22;5(200):895-9.
Skin diseases may have severe aesthetic and psychological repercussions leading
sometimes to discriminations and social isolation. Dermatologists have
contributed to the development of many cosmetic procedures: peelings, botulinum
toxin or hyaluronic acid injections, lasers, blepharoplasty, facelift, etc. Many
of these treatments have interesting clinical applications and may help numerous
patients with skin diseases to return to a normal social life.
[Thermal lasers and wound healing] [Article in French] Mordon S. Rev Med Suisse. 2009 Apr 22;5(200):890-2, 894.
The wound healing is a complex biological process, which induces a dermal
remodelling leading at minimum to a visible scar to an hypertrophic scar. In
opposition, regeneration of a tissue or organ is the reconstitution ad integro of
this organ. Recent studies suggest that by using laser, which generates a
precisely defined thermal effect in the skin, it became possible to improve the
wound healing process to become closer to tissue regeneration.
Nanoparticles for cancer treatment: role of heat transfer. Avedisian CT, Cavicchi RE, McEuen PL, Zhou X. Ann N Y Acad Sci. 2009 Apr;1161:62-73.
An overview is presented of an approach for treating cancer that uses
nanoparticles to deliver heat to diseased areas after absorbing energy from a
laser of the appropriate wavelength. The implications are discussed of the
relationship of parameters necessary to raise the temperature to therapeutically
beneficial levels. Tight focusing is required for a continuous-wave laser to
sufficiently heat individual nanoparticles because of heat loss to the
surrounding fluid during the period of exposure. The natural thermal confinement
of pulse lasers minimizes this effect because of the finite thermal diffusion
time, which restricts the absorbed energy to a region around the particle, that
offers the potential for achieving high temperatures that can promote phase
change on the surface of a nanoparticle or even melting of the particle. A
discussion of a way to potentially measure temperature on the scale of an
individual nanoparticle is included based on using a single-walled nanotube
(SWNT) of carbon as a thermistor. The challenges of this undertaking are that
SWNTs do not always follow Ohm’s law, they may exhibit metallic or semiconductor
behavior with an often unpredictable result in manufacturing, and no two SWNTs
behave identically, which necessitates calibration for each SWNT. Some results
are presented that show the electrical characteristics of SWNTs and their
potential for exploitation in this application.
Enhanced operation of femtosecond lasers and applications in cell transfection. Brown CT, Stevenson DJ, Tsampoula X, McDougall C, Lagatsky AA, Sibbett W, Gunn-Moore FJ, Dholakia K. J Biophotonics. 2008 Aug;1(3):183-99.
In this work we present a review and discussion on the enhancement of femtosecond
(fs) lasers for use within biophotonics with a particular focus on their use in
optical transfection techniques. We describe the broad range of source options
now available for the generation of femtosecond pulses before briefly reviewing
the application of fs laser in optical transfection studies. We show that major
performance enhancements may be obtained by optimising the spatial and temporal
performance of the laser source before considering possible future directions in
this field. In relation to optical transfection we describe how such laser
sources initiate a multiphoton process to permeate the cell membrane in a
transient fashion. We look at aspects of this technique including the ability to
combine transfection with optical trapping. For future implementation of such
transfection we explore the role of new sources and “nondiffracting” light
New insights into the management of acne: an update from the Global Alliance to Improve Outcomes in Acne group. Thiboutot D, Gollnick H, Bettoli V, Dréno B, Kang S, Leyden JJ, Shalita AR, Lozada VT, Berson D, Finlay A, Goh CL, Herane MI, Kaminsky A, Kubba R, Layton A, Miyachi Y, Perez M, Martin JP, Ramos-E-Silva M, See JA, Shear N, Wolf J Jr; Global Alliance to Improve Outcomes in Acne. J Am Acad Dermatol. 2009 May;60(5 Suppl):S1-50.
The Global Alliance to Improve Outcomes in Acne published recommendations for the
management of acne as a supplement to the Journal of the American Academy of
Dermatology in 2003. The recommendations incorporated evidence-based strategies
when possible and the collective clinical experience of the group when evidence
was lacking. This update reviews new information about acne pathophysiology and
treatment-such as lasers and light therapy-and relevant topics where published
data were sparse in 2003 but are now available including combination therapy,
revision of acne scarring, and maintenance therapy. The update also includes a
new way of looking at acne as a chronic disease, a discussion of the changing
role of antibiotics in acne management as a result of concerns about microbial
resistance, and factors that affect adherence to acne treatments. Summary
statements and recommendations are provided throughout the update along with an
indication of the level of evidence that currently supports each finding. As in
the original supplement, the authors have based recommendations on published
evidence as much as possible.
Quantitative in vivo imaging of entire embryos with Digital Scanned Laser Light Sheet Fluorescence Microscopy. Keller PJ, Stelzer EH. Curr Opin Neurobiol. 2008 Dec;18(6):624-32. Epub 2009 Apr 15.
The observation of biological processes in their natural in vivo context is a key
requirement for quantitative experimental studies in the life sciences. In many
instances, it will be crucial to achieve high temporal and spatial resolution
over long periods of time without compromising the physiological development of
the specimen. Here, we discuss the principles underlying light sheet-based
fluorescence microscopes. The most recent implementation DSLM is a tool optimized
to deliver quantitative data for entire embryos at high spatio-temporal
resolution. We compare DSLM to the two established light microscopy techniques:
confocal and two-photon fluorescence microscopy. DSLM provides up to 50 times
higher imaging speeds and a 10-100 times higher signal-to-noise ratio, while
exposing the specimens to at least three orders of magnitude less light energy
than confocal and two-photon fluorescence microscopes. We conclude with a
perspective for future development.
Evidence-based dentistry on laser paediatric dentistry: review and outlook. Olivi G, Genovese MD, Caprioglio C. Eur J Paediatr Dent. 2009 Mar;10(1):29-40.
AIM: The goal of paediatric dentistry is to provide preventive education to
parents and patients as well as interception and therapy of dental diseases in a
minimally invasive way using a stress-free approach. Different laser wavelengths
are used for different applications following these minimally invasive concepts:
argon, KTP, diode, Nd:YAG, and CO2 lasers are used for soft tissue applications
and the erbium family is used for both soft and hard tissue procedures. This
paper offers a revision and a discussion of the international literature, showing
also some clinical procedures. related to these scientific studies. Soft tissues
laser applications in Pediatric Dentistry include application in oral surgery as
well as in periodontics and orthodontics. Laser applications on hard tissues
include caries prevention and detection and application for sealing of pits and
fissures. Also application for cavity preparation, carious removal and pulp
therapy are discussed.
Molecular mechanism of protein assembly on DNA double-strand breaks in the non-homologous end-joining pathway. Yano K, Morotomi-Yano K, Adachi N, Akiyama H. J Radiat Res (Tokyo). 2009 Mar;50(2):97-108.
Non-homologous end-joining (NHEJ) is the major repair pathway for DNA
double-strand breaks (DSBs) in mammalian species. Upon DSB induction, a living
cell quickly activates the NHEJ pathway comprising of multiple molecular events.
However, it has been difficult to analyze the initial phase of DSB responses in
living cells, primarily due to technical limitations. Recent advances in
real-time imaging and site-directed DSB induction using laser microbeam allow us
to monitor the spatiotemporal dynamics of NHEJ factors in the immediate-early
phase after DSB induction. These new approaches, together with the use of cell
lines deficient in each essential NHEJ factor, provide novel mechanistic insights
into DSB recognition and protein assembly on DSBs in the NHEJ pathway. In this
review, we provide an overview of recent progresses in the imaging analyses of
the NHEJ core factors. These studies strongly suggest that the NHEJ core factors
are pre-assembled into a large complex on DSBs prior to the progression of the
biochemical reactions in the NHEJ pathway. Instead of the traditional
step-by-step assembly model from the static view of NHEJ, a novel model for
dynamic protein assembly in the NHEJ pathway is proposed. This new model provides
important mechanistic insights into the protein assembly at DSBs and the
regulation of DSB repair.
Laser tissue welding in ophthalmic surgery. Rossi F, Matteini P, Ratto F, Menabuoni L, Lenzetti I, Pini R. J Biophotonics. 2008 Sep;1(4):331-42.
Laser welding of ocular tissues is an alternative technique or adjunct to
conventional suturing in ophthalmic surgery. It is based on the photothermal
interaction of laser light with the main components of the extracellular matrix
of connective tissues. The advantages of the welding procedure with respect to
standard suturing and stapling are reduced operation times, lesser inflammation,
faster healing and increased ability to induce tissue regeneration. The procedure
we set up is based on the use of an infrared diode laser in association with the
topical application of the chromophore Indocyanine Green. Laser light may be
delivered either continuously or in pulses, thus identifying two different
techniques that have been applied clinically in various types of transplants of
Laser applications in endodontics: an update review. Mohammadi Z. Int Dent J. 2009 Feb;59(1):35-46.
The search for new devices and technologies for endodontic procedures always has
been challenging. Since the development of the ruby laser by Maiman in 1960 and
the application of the laser for endodontics by Weichman in 1971, a variety of
potential applications for lasers in endodontics have been proposed. With the
development of thinner, more flexible and durable laser fibres, laser
applications in endodontics have increased. Since laser devices are still
relatively costly, access to them is limited. The purpose of this paper is to
summarise laser applications in endodontics, including their use in pulp
diagnosis, dentinal hypersensitivity, pulp capping and pulpotomy, sterilisation
of root canals, root canal shaping and obturation and apicectomy. The effects of
lasers on root canal walls and periodontal tissues are also reviewed.
Transcanalicular approach to adult lacrimal duct obstruction: a review of instruments and methods. Athanasiov PA, Prabhakaran VC, Mannor G, Woog JJ, Selva D. Ophthalmic Surg Lasers Imaging. 2009 Mar-Apr;40(2):149-59.
Developments in fiberoptic technology and increasing interest in minimally
invasive surgery have fueled advances in transcanalicular surgery. This article
presents a review of instruments and methods for diagnostic and therapeutic
approaches to adult lacrimal drainage obstruction. Available endocanalicular
probes, microendoscopes, lasers, microdrills, trephines, and antegrade lacrimal
balloon catheters are discussed and compared. Developments in microendoscopy,
laser transcanalicular dacryocystorhinostomy, laser canaliculoplasty,
transcanalicular drilling and trephination, and transcanalicular balloon
dacryoplasty are also discussed in detail. Transcanalicular surgery provides a
minimally invasive approach to adult lacrimal drainage obstruction that may also
address the pathology causing the obstruction. Long-term success rates of
transcanalicular dacryocystorhinostomy appear to be improving, but cost and a
paucity of data on long-term results continue to limit the use of
[Review of literature concerning the use of laser treatment for symptomatic BPH] [Article in French] Fourmarier M, Azzouzi AR, Robert G, Saussine C, Devonec M, Haillot O, Ballereau C, Lukacs B, de la Taille A; le Comité des troubles mictionnels de l’homme (CTMH) de l’Association française d’urologie. Prog Urol. 2009 Mar;19(3):153-7. Epub 2008 Dec 30.
Even if transurethral resection of the prostate (TURP) today remains the
referential surgery in the treatment of symptomatic benign prostatic hyperplasia
(BPH), the last decade has seen the emergence of considerable improvements in
light amplification by stimulated emission of radiation (LASER) technology.
Better understanding of the interaction between the different wavelengths of
these lasers and tissue has enabled the development of new and promising types of
treatment. This article, through a review of published literature, attempts first
of all to retrace the history of this technique in the treatment of symptomatic
BPH and then goes on to give an update on results and new aspects of the
different types of laser used.
The pseudoaccommodative cornea multifocal ablation with a center-distance pattern: a review. Telandro A. J Refract Surg. 2009 Jan;25(1 Suppl):S156-9.
PURPOSE: To describe an excimer laser ablation architecture called the
pseudoaccommodative cornea (PAC) that uses ocular aberrometry and aspheric
ablation profiles to create a multifocal cornea. METHODS: A descriptive article
outlining the theory of the PAC algorithm. RESULTS: The topographic changes
induced by PAC produce corneal multifocality. CONCLUSIONS: PAC-treated eyes have
progressive concentric rings of center-distance and midperipheral-near power that
enable functional vision at near, intermediate, and distance.
Ultraviolet photofragmentation of biomolecular ions. Reilly JP. Mass Spectrom Rev. 2009 May-Jun;28(3):425-47.
Mass spectrometric identification of all types of molecules relies on the
observation and interpretation of ion fragmentation patterns. Peptides, proteins,
carbohydrates, and nucleic acids that are often found as components of complex
biological samples represent particularly important challenges. The most common
strategies for fragmenting biomolecular ions include low- and high-energy
collisional activation, post-source decay, and electron capture or transfer
dissociation. Each of these methods has its own idiosyncrasies and advantages but
encounters problems with some types of samples. Novel fragmentation methods that
can offer improvements are always desirable. One approach that has been under
study for years but is not yet incorporated into a commercial instrument is
ultraviolet photofragmentation. This review discusses experimental results on
various biological molecules that have been generated by several research groups
using different light wavelengths and mass analyzers. Work involving
short-wavelength vacuum ultraviolet light is particularly emphasized. The
characteristics of photofragmentation are examined and its advantages summarized.
(c) 2009 Wiley Periodicals, Inc.
Vibrational spectroscopy of bare and solvated ionic complexes of biological relevance. Polfer NC, Oomens J. Mass Spectrom Rev. 2009 May-Jun;28(3):468-94.
The low density of ions in mass spectrometers generally precludes direct infrared
(IR) absorption measurements. The IR spectrum of an ion can nonetheless be
obtained by inducing photodissociation of the ion using a high-intensity tunable
laser. The emergence of free electron lasers (FELs) and recent breakthroughs in
bench-top lasers based on nonlinear optics have now made it possible to routinely
record IR spectra of gas-phase ions. As the energy of one IR photon is
insufficient to cause dissociation of molecules and strongly bound complexes, two
main experimental strategies have been developed to effect photodissociation. In
infrared multiple-photon dissociation (IR-MPD) many photons are absorbed
resonantly and their energy is stored in the bath of vibrational modes, leading
to dissociation. In the “messenger” technique a weakly bound van der Waals atom
is detached upon absorption of a single photon. Fundamental, historical, and
practical aspects of these methods will be presented. Both of these approaches
make use of very different methods of ion preparation and manipulation. While in
IR-MPD ions are irradiated in trapping mass spectrometers, the “messenger”
technique is generally carried out in molecular beam instruments. The main focus
of this review is the application of IR spectroscopy to biologically relevant
molecular systems (amino acids, peptides, proteins). Particular issues that will
be addressed here include gas-phase zwitterions, the (chemical) structures of
peptides and their collision-induced dissociation (CID) products, IR spectra of
gas-phase proteins, and the chelation of metal-ligand complexes. Another growing
area of research is IR spectroscopy on solvated clusters, which offer a bridge
between the gas-phase and solution environments. The development of
state-of-the-art computational approaches has gone hand-in-hand with advances in
experimental techniques. The main advantage of gas-phase cluster research, as
opposed to condensed-phase experiments, is that the systems of interest can be
understood in detail and structural effects can be studied in isolation. It will
be shown that IR spectroscopy of mass-selected (bio)molecular systems is now
well-placed to address specific questions on the individual effect of charge
carriers (protons and metal ions), as well as solvent molecules on the overall
structure. (c) 2009 Wiley Periodicals, Inc.
Treatment of nodules associated with port wine stains with CO2 laser: case series and review of the literature. Tierney EP, Hanke CW. J Drugs Dermatol. 2009 Feb;8(2):157-61.
BACKGROUND: Port wine stains (PWS) are congenital malformations of capillaries,
where with progression, blood vessels become ectatic and result in disfiguring
nodules. OBJECTIVE: To search the MEDLINE database and review literature on the
treatment of PWS and present 2 cases of adults with PWS, complicated by
hypertrophic and nodular lesions, treated successfully with CO2 laser. RESULTS:
Two patients with PWS, with nodular and hypertrophic areas, were treated with CO2
laser. With the first patient, improvement of 90% or greater was noted in the 14
discrete nodules present within the PWS in a V2 distribution. At baseline,
ectropion of the lower eyelid was noted which resolved completely after CO2
laser. With the second patient, improvement was noted as 90% or greater in the 40
of 51 discrete nodules present within the PWS extending across the right V1-V2
distribution. CONCLUSION: Carbon dioxide ablative laser resurfacing is safe and
highly effective in the treatment of the nodular and hypertrophic components of
PWS. Future treatment of PWS will likely involve a hybrid approach of utilizing
nonablative lasers of varying wavelengths and pulse durations and treatment with
novel laser devices, with the goal of early treatment to prevent progression of
PWS to disfiguring lesions.
Laser microdissection and its application to analyze gene expression in arbuscular mycorrhizal symbiosis. Gomez SK, Harrison MJ. Pest Manag Sci. 2009 May;65(5):504-11.
Phosphorus is essential for plant growth, and in many soils phosphorus
availability limits crop production. Most plants in natural ecosystems obtain
phosphorus via a symbiotic partnership with arbuscular mycorrhizal (AM) fungi.
While the significance of these associations is apparent, their molecular basis
is poorly understood. Consequently, the potential to harness the mycorrhizal
symbiosis to improve phosphorus nutrition in agriculture is not realized.
Transcript profiling has recently been used to investigate gene expression
changes that accompany development of the AM symbiosis. While these approaches
have enabled the identification of AM-symbiosis-associated genes, they have
generally involved the use of RNA from whole mycorrhizal roots. Laser
microdissection techniques allow the dissection and capture of individual cells
from a tissue. RNA can then be isolated from these samples and cell-type specific
gene expression information can be obtained. This technology has been applied to
obtain cells from plants and more recently to study plant-microbe interactions.
The latter techniques, particularly those developed for root-microbe
interactions, are of relevance to plant-parasitic weed research. Here, laser
microdissection, its use in plant biology and in particular plant-microbe
interactions are discussed. An overview of the AM symbiosis is then provided,
with a focus on recent advances in understanding development of the
arbuscule-cortical cell interface. Finally, the recent applications of laser
microdissection for analyses of AM symbiosis are discussed.
[Dental caries--therapeutic possibilities] [Article in Serbian] Perić T, Marković D, Zivković S. Srp Arh Celok Lek. 2008 Nov-Dec;136(11-12):662-6.
Contemporary tendencies in dentistry are based on the concept of maximal
protection of healthy tooth tissues. Caries removal has been done traditionally
with mechanical rotary instruments that are fast and precise. However,
conventional cavity preparation has potential adverse effects to the pulp due to
heat, pressure and vibrations. Moreover, drilling often causes pain and requires
local anaesthesia, and these procedures are frequently perceived as unpleasant.
Etiology, development and prevention of dental caries are better understood today
and new restorative materials that bond micromechanically and/or chemically to
dental tissues have been introduced. Thus, development of a new, less destructive
caries removal technique is allowed. In the last decades, many alternative
methods have been introduced in an attempt to replace rotary instruments. These
are claimed to be efficient and selective for diseased tissues and to offer
comfortable treatment to the patients. New methods include air abrasion, air
polishing, ultrasonic, polymer burs, enzymes, systems for chemo-mechanical caries
removal, and lasers. The aim of this paper was to discuss various caries removal
techniques and possibilities of their use in clinical practice. Based on the
literature review it can be concluded that none of the new caries removal methods
can completely replace conventional rotary instruments.
Application of nonlinear optical microscopy for imaging skin. Hanson KM, Bardeen CJ. Photochem Photobiol. 2009 Jan-Feb;85(1):33-44.
Recent advances in the use of nonlinear optical microscopy (NLOM) in skin
microscopy are presented. Nonresonant spectroscopies including second harmonic
generation, coherent anti-Stokes Raman and two-photon absorption are described
and applications to problems in skin biology are detailed. These nonlinear
techniques have several advantages over traditional microscopy methods that rely
on one-photon excitation: intrinsic 3D imaging with <1 microm spatial resolution,
decreased photodamage to tissue samples and penetration depths up to 1,000 microm
with the use of near-infrared lasers. Thanks to these advantages, nonlinear
optical spectroscopy has become a powerful tool to study the physical and
biochemical properties of the skin. Structural information can be obtained using
the response of endogenous chemical species in the skin, such as collagen or
lipids, indicating that optical biopsy may replace current invasive,
time-consuming traditional histology methods. Insertion of specific probe
molecules into the skin provides the opportunity to monitor specific biochemical
processes such as skin transport, molecular penetration, barrier homeostasis and
ultraviolet radiation-induced reactive oxygen species generation. While the field
is quite new, it seems likely that the use of NLOM to probe structure and
biochemistry of live skin samples will only continue to grow.
Revival of extra-intracranial bypass surgery. Vajkoczy P. Curr Opin Neurol. 2009 Feb;22(1):90-5.
PURPOSE OF REVIEW: Extra-intracranial bypass surgery has regained significant
relevance over the past years. The aim of this review is to highlight the current
indications and recent developments in this field. RECENT FINDINGS: One main
indication today is stroke prevention by flow augmentation in the setting of
chronic cerebral hemodynamic ischemia which is defined as a combination of
steno-oclusive cerebrovascular disease, inadequate collateralization, and loss of
cerebrovascular reserve capacity. Another indication is flow replacement in the
context of therapy of complex aneurysms and skull base tumors. The herein
proposed revival of bypass surgery is due to the progress in individualized,
tailored therapeutic strategies as well as patient selection. Furthermore, we
witness a dramatic improvement in the surgical technique as well as the
development of a broad armamentarium of different bypass types, which today allow
tailored revascularization strategies for our patients. Finally, the revival of
bypass surgery is also explained by significant technical progress. One of the
major developments within the last years is the Excimer laser-assisted
nonocclusive anastomosis technique which allows performance of an anastomosis
without the need for temporary clipping, thus dramatically reducing the risk for
perioperative ischemia in bypass surgery. SUMMARY: Extra-intracranial bypass
surgery has become a central part of a highly specialized, interdisciplinary
strategy for the therapy of complex aneurysms and skull base tumors.
Complications of nonphysician-supervised laser hair removal: case report and literature review. Vano-Galvan S, Jaen P. Can Fam Physician. 2009 Jan;55(1):50-2.
Department of Dermatology, Ramón y Cajal University Hospital, Carretera Colmenar
Viejo, Madrid, Spain. firstname.lastname@example.org
[Photodynamic therapy: principles and therapeutic indications] [Article in French] Ficheux H. Ann Pharm Fr. 2009 Jan;67(1):32-40. Epub 2008 Dec 13.
Photodynamic therapy consists in destroying a tumoral or a non tumoral tissue by
the effect of both a photosensitizing molecule and a laser light. This simple
concept has needed numerous years in order to be used in routine treatments with
both photosensitizers and laser light delivered optimally. Researches in
chemistry lead to new porphyrin and bacteriochlorophyl derivatives which
alleviate the decrease of light absorption by endogenous molecules and in
consequence allow a deeper light penetration. Short half-life of these compounds
allows an easier treatment monitoring. In parallel, improvements in both laser
technology and fibers allow new indications in various pathologies. First
applications took place in treatment of respiratory, digestive and urologic
cancers. The biggest success to date is recorded in ophthalmology with the
treatment of age related macular degeneration. New approaches are explored and
clinical studies are ongoing.
Update on lasers and light devices for the treatment of vascular lesions. Galeckas KJ. Semin Cutan Med Surg. 2008 Dec;27(4):276-84.
Patients frequently present to dermatologists for the treatment of vascular
lesions, including facial telangiectases, diffuse redness, port wine stains
(PWS), hemangiomas, and leg veins. There are many laser and light devices that
can be used with excellent results. This article summarizes the available
platforms that are commonly used for the treatment of superficial vascular
lesions. Newer devices and techniques are highlighted with respect to the unique
characteristics of individual lesions.
[Glaucoma--strategy of treatment] [Article in Romanian] Stefan C, Selaru D, Stefaniu I, Dumitrică DM. Oftalmologia. 2008;52(3):3-6.
Evaluation of plasma skin regeneration technology for cutaneous remodeling. Elsaie ML, Kammer JN. J Cosmet Dermatol. 2008 Dec;7(4):309-11.
Plasma skin regeneration is a novel type of skin rejuvenation technology
developed over the last 3 years. Plasma is the fourth state of matter in which
electrons are stripped from atoms to form an ionized gas. Although
high-temperature plasmas have been used in surgery for over a decade, plasma had
previously been used as a conduction medium for electric current. Unlike lasers,
which rely on the principle of selective photothermolysis to deliver heat to
specific targets in the skin, plasma technology delivers heat energy directly to
tissue upon contact without reliance on skin chromophores. The plasma itself
produces controlled thermal damage to the skin surface to elicit changes such as
new collagen formation and improvement in photodamaged skin. The technology can
be used at varying energies for different depths of effect, from superficial
epidermal effects to deeper dermal heating.
[New perspectives for laser therapy] [Article in Spanish] Amón Sesmero JH. Arch Esp Urol. 2008 Nov;61(9):1163-9.
We review the current trends and new perspectives of the use of laser in urology,
analyzing different fields in which this energy has been used. In lithotripsy,
the laser has modified the therapeutic algorithms for ureteral lithiasis.
Moreover, the possibility of using laser with flexible ureteroscopes is enabling
the performance of intracorporeal in situ renal lithotripsy. New lasers such as
Erbium:yag, more effective and more innocuous than holmium are currently under
development. The research in new fibers, more flexible, economic and long-lasting
is the next challenge in this field. In BPH, although the KTP laser has obtained
and extraordinary diffusion for a certain type of prostate volume, new lasers
such as thulium and diode, are in competition with holmium laser in the field of
prostatic enucleation due to their precise cut. The application of laser in
photodynamic therapy for urological cancers and tissue welding are currently new
promising objectives of research.
[Robotic surgery and laser technology: an opportunity for discovery] [Article in Spanish] Martínez-Salamanca JI, Martínez Ballesteros C, Tewari A, Carballido JA. Arch Esp Urol. 2008 Nov;61(9):1157-62.
The use of laser technology in the field of urologic surgery has experienced
great advances over the past 20 years. Since the beginning of this century
robotic technology has landed in a determined manner in our specially and every
day will be more and more indications on what is going to have a final
deployment. The current combination of laser and surgical robots, can be focused
on two distinct areas, but possibly complementary, the use of lasers to guide the
surgical procedure, what we might call "landmarks and structures recognition" or
"positioning" and laser use because of its ablative ability minimizing blood loss
and increasing the resection accuracy. This paper reviews most recent articles
and contributions on the combination of these two technologies.
[Prostate and KTP laser] [Article in Spanish] Hernández Fernández C, Subirá Rios D, Bueno Chomón G, Tabares Jiménez J. Arch Esp Urol. 2008 Nov;61(9):1023-7.
OBJECTIVES: To analyze safety and efficacy of KTP green laser photovaporization
for the treatment of lower urinary tract obstruction caused by benign prostatic
hyperplasia based on data from the medical literature. RESULTS: Most articles
consulted emphasize its low complication rate, efficacy, and short learning
curve. They have the limitation that most papers are not comparative, the number
of patients included is low, and follow-up in many of them short. CONCLUSIONS:
Prostatic vaporization with KTP laser is today an alternative to TUR, more in
patients with comorbidities, due to its low complication rate. Nevertheless, we
accept it is an expensive technology and more follow-up is required to confirm
the results remain.
Current techniques for laser prostatectomy--PVP and HoLEP. Aho TF, Gilling PJ. Arch Esp Urol. 2008 Nov;61(9):1005-13.
OBJECTIVES: The objective of this review is to provide an evidence-based update
on laser surgery for BPH with a focus on comparing Greenlight Photoselective
Vaporisation of the Prostate (PVP) to Holmium Laser Enucleation of the Prostate
(HoLEP). METHODS: We reviewed all HoLEP and PVP papers identified by a Pubmed
search using the keywords: laser, prostate, BPH, holmium, HoLE, PVP and
greenlight. The published randomised trials investigating HoLEP and PVP are
summarised. As there are no head to head randomised trials comparing HoLEP to
PVP, we compare data from individual HoLEP and PVP papers. Data on multiple
aspects of laser surgery for BPH are summarised and contrasted for the 2
procedures including: Perioperative management, subjective and objective measures
of success, complications, sexual function, prostate volume reduction,
durability, and surgery for men with large prostates and those in urinary
retention. RESULTS/CONCLUSIONS: PVP and HoLEP are very different laser
techniques. An important difference between the Greenlight laser and holmium and
thulium is that its only urological application is prostate ablation. HoLEP is
the most advanced laser technique currently available. In contrast to PVP, it has
been rigorously evaluated in 8 randomised trials. It is a size independent
procedure suitable for any prostate, and highly effective at treating urinary
retention. HoLEP has been reported to be durable to periods up to 6 years. More
tissue is removed with HoLEP than PVP and this raises concerns regarding the long
term durability of PVP for which there is no comparable data. The increase in
HoLEP expertise worldwide and the development of lasers that are faster at
ablating tissue and have other urological uses (eg thulium) may threaten the
longevity of Greenlight PVP.
Urologic laser types and instrumentation. Natalin RA, Phillips CK, Clayman RV, Landman J. Arch Esp Urol. 2008 Nov;61(9):971-7.
Though the primary role of lasers in urology has always been in the treatment of
urolithiasis, there are several other indications for their use. There are many
different types of lasers currently available, each with unique properties
conducive to treating certain disorders. As such, it is critical that today's
urologist understands each laser's characteristics in order to optimize patient
selection and treatment. The lasers which are primarily used in urologic
applications include the carbon dioxide (CO2) laser; the
Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG); the Potassium Titanyl Phosphate (KTP)
laser and the Holmium:YAG (Ho:YAG) laser. This review focuses on the unique
characteristics of each of these lasers as well as the instrumentation needed
utilize and deploy these tools in the urinary tract.
Chloasma--the mask of pregnancy. Bolanca I, Bolanca Z, Kuna K, Vuković A, Tuckar N, Herman R, Grubisić G. Coll Antropol. 2008 Oct;32 Suppl 2:139-41.
Chloasma is a required hypermelanosis of sun-exposed areas occurred during
pregnancy and it can affect 50-70% of pregnant women. It presents as symmetric
hyperpigmented macules, which can confluent or punctuate. The most common
locations are the cheeks, the upper lip, the chin and the forehead. The exact
mechanism by which pregnancy affects the process of melanogenesis is unknown.
Estrogen, progesterone, and melanocyte-stimulating hormone (MSH) levels are
normally increased during the third trimester of pregnancy. However, nulliparous
patients with chloasma have no increased levels of estrogen or MSH. In addition,
the occurrence of melasma with estrogen- and progesterone-containing oral
contraceptive pills has been reported. The observation that postmenopausal woman
who are given progesterone develop melasma, while those who are given only
estrogen do not, implicates progesterone as playing a critical role in the
development of melasma. UV-B, UV-A, and visible light are all capable of
stimulating melanogenesis. The condition is self-limited; however spontaneous
resolution is time-consuming and may take months to resolve normal pigmentation.
Therefore, it is worthwhile to prevent the onset of chloasma, by strict
photoprotection. Prudent measures to avoid sun exposure include hats and other
forms of shade combined with the application of a broad-spectrum sunscreen at
least daily. Sunscreens containing physical blockers, such as titanium dioxide
and zinc oxide, are preferred over chemical blockers because of their broader
protection. Chloasma can be difficult to treat. Quick fixes with destructive
modalities (eg, cryotherapy, medium-depth chemical peels, lasers) yield
unpredictable results and are associated with a number of potential adverse
effects. The mainstay of treatment remains topical depigmenting agents.
Hydroquinone (HQ) is most commonly used.
Macular and retinal nerve fibre layer thickness in strabismus and anisometropic amblyopia. Leone J, Koklanis K, Georgievski Z, Wilkinson R. Binocul Vis Strabismus Q. 2008;23(4):227-34.
Electrophysiological studies investigating the relationship between amblyopia and
retinal function have in the past produced conflicting findings, leaving the
retinal correlates of amblyopia, if they exist, unknown. Recent advances in
technology, and in particular the emergence of optical coherence tomography, has
resulted in further investigations of the retinal nerve fibre layer and macula of
amblyopia patients using these instruments. This review summarises the recent
literature in this area and discusses various issues relating to this research.
Light at work: the use of optical forces for particle manipulation, sorting, and analysis. Jonás A, Zemánek P. Electrophoresis. 2008 Dec;29(24):4813-51.
We review the combinations of optical micro-manipulation with other techniques
and their classical and emerging applications to non-contact optical separation
and sorting of micro- and nanoparticle suspensions, compositional and structural
analysis of specimens, and quantification of force interactions at the
microscopic scale. The review aims at inspiring researchers, especially those
working outside the optical micro-manipulation field, to find new and interesting
applications of these methods.
Pathophysiology of selective laser trabeculoplasty. Murthy S, Latina MA. Int Ophthalmol Clin. 2009 Winter;49(1):89-98.
Chiropractic management of tendinopathy: a literature synthesis. Pfefer MT, Cooper SR, Uhl NL. J Manipulative Physiol Ther. 2009 Jan;32(1):41-52.
OBJECTIVE: Chronic tendon pathology is a soft tissue condition commonly seen in
chiropractic practice. Tendonitis, tendinosis, and tendinopathy are terms used to
describe this clinical entity. The purpose of this article is to review
interventions commonly used by doctors of chiropractic when treating
tendinopathy. METHODS: The Scientific Commission of the Council on Chiropractic
Guidelines and Practice Parameters (CCGPP) was charged with developing literature
syntheses, organized by anatomical region, to evaluate and report on the evidence
base for chiropractic care. This article is the outcome of this charge. As part
of the CCGPP process, preliminary drafts of these articles were posted on the
CCGPP Web site www.ccgpp.org (2006-8) to allow for an open process and the
broadest possible mechanism for stakeholder input. A literature search was
performed using the PubMed; Cumulative Index to Nursing and Allied Health
Literature; Index to Chiropractic Literature; Manual, Alternative, and Natural
Therapy Index System; National Guidelines Clearinghouse; Database of Abstracts of
Reviews of Effects; and Turning Research Into Practice databases. The inclusion
criteria were manual therapies, spinal manipulation, mobilization, tendonitis,
tendinopathy, tendinosis, cryotherapy, bracing, orthotics, massage, friction
massage, transverse friction massage, electrical stimulation, acupuncture,
exercise, eccentric exercise, laser, and therapeutic ultrasound. RESULTS: There
is evidence that ultrasound therapy provides clinically important improvement in
the treatment of calcific tendonitis. There is limited evidence of the benefit of
manipulation and mobilization in the treatment of tendinopathy. Limited evidence
exists to support the use of supervised exercise, eccentric exercise, friction
massage, acupuncture, laser therapy, use of bracing, orthotics, and cryotherapy
in the treatment of tendinopathy. CONCLUSION: Chiropractors often provide a
number of conservative interventions commonly used to treat tendinopathy.
Chiropractic management of myofascial trigger points and myofascial pain syndrome: a systematic review of the literature. Vernon H, Schneider M. J Manipulative Physiol Ther. 2009 Jan;32(1):14-24.
OBJECTIVES: Myofascial pain syndrome (MPS) and myofascial trigger points (MTrPs)
are important aspects of musculoskeletal medicine, including chiropractic. The
purpose of this study was to review the most commonly used treatment procedures
in chiropractic for MPS and MTrPs. METHODS: The Scientific Commission of the
Council on Chiropractic Guidelines and Practice Parameters (CCGPP) was charged
with developing literature syntheses, organized by anatomical region, to evaluate
and report on the evidence base for chiropractic care. This article is the
outcome of this charge. As part of the CCGPP process, preliminary drafts of these
articles were posted on the CCGPP Web site www.ccgpp.org (2006-8) to allow for an
open process and the broadest possible mechanism for stakeholder input. PubMed,
Excerpta Medica Database, Cumulative Index to Nursing and Allied Health
Literature, and databases for systematic reviews and clinical guidelines were
searched. Separate searches were conducted for (1) manual palpation and
algometry, (2) chiropractic and other manual therapies, and (3) other
conservative and complementary/alternative therapies. Studies were screened for
relevance and rated using the Oxford Scale and Scottish Intercollegiate
Guidelines Network rating system. RESULTS: A total of 112 articles were
identified. Review of these articles resulted in the following recommendations
regarding treatment: Moderately strong evidence supports manipulation and
ischemic pressure for immediate pain relief at MTrPs, but only limited evidence
exists for long-term pain relief at MTrPs. Evidence supports laser therapy
(strong), transcutaneous electrical nerve stimulation, acupuncture, and magnet
therapy (all moderate) for MTrPs and MPS, although the duration of relief varies
among therapies. Limited evidence supports electrical muscle stimulation,
high-voltage galvanic stimulation, interferential current, and frequency
modulated neural stimulation in the treatment of MTrPs and MPS. Evidence is weak
for ultrasound therapy. CONCLUSIONS: Manual-type therapies and some physiologic
therapeutic modalities have acceptable evidentiary support in the treatment of
MPS and TrPs.
Laser microbeams and optical tweezers in ageing research. Grigaravicius P, Greulich KO, Monajembashi S. Chemphyschem. 2009 Jan 12;10(1):79-85.
We show how a technique developed within the framework of physics and physical
chemistry-in a true interdisciplinary approach-can answer questions in life
sciences that are not solvable by using other techniques. Herein, we focus on
blood-pressure regulation and DNA repair in ageing studies. Laser microbeams and
optical tweezers are now established tools in many fields of science,
particularly in the life sciences. A short glimpse is given on the wide field of
non-age-research applications in life sciences. Then, optical tweezers are used
to show that exerting a vertical pressure on cells representing the inner lining
of blood vessels results in bursts of NO liberation concomitant with large
changes in cell morphology. Repeated treatment of such human umbilical vein
endothelial cells (HUVEC) results in stiffening, a hallmark of manifest high
blood pressure, a disease primarily of the elderly. As a second application in
ageing research, a laser microbeam is used to induce, with high spatial and
temporal resolution, DNA damages in the nuclei of U2OS human osteosarcoma cells.
A pairwise study of the recruitment kinetics of different DNA repair proteins
reveals that DNA repair starts with non-homologous end joining (NHEJ), a repair
pathway, and may only after several minutes switch to the error-free homologous
recombination repair (HRR) pathway. Since DNA damages-when incorrectly
repaired-accumulate with time, laser microbeams are becoming well-used tools in
Current use and future perspectives of diagnostic and therapeutic lasers in Oral Medicine. Maia AM, Barkokebas A, Pires AP, Barros LF, Carvalho AA, Leão JC. Minerva Stomatol. 2008 Oct;57(10):511-7.
Several diagnostic and therapeutic methods are based on the optical properties of
lasers. In therapeutic applications, laser light is absorbed in a specific
manner, whereas light is scattered, reflected, or transmitted from different
structures. Improvements in laser technology allow new procedures and broaden the
scope of applications for both diagnosis and therapy. The focus of laser
application in Oral Medicine diagnosis should be early detection of oral squamous
cell carcinoma. Novel modalities for the detection of oral malignancy are
urgently needed, while others must be continuously improved. Optical coherence
tomography and laser-induced fluorescence spectroscopy are currently being
studied. In addition to diagnosis of non-malignant lesions, laser therapy has
been used based upon the biological reactions and molecular wound healing
mechanisms as an alternative for the treatment of a variety of oral soft tissue
lesions. The aim of the present article is to review current knowledge and future
perspectives of lasers in Oral Medicine.
Argon plasma coagulation, bipolar cautery, and cryotherapy: ABC's of ablative techniques. Dumot JA, Greenwald BD. Endoscopy. 2008 Dec;40(12):1026-32. Epub 2008 Dec 8.
A variety of endoscopic ablation modalities are available for the treatment of
Barrett's esophagus. Multiple studies have evaluated the use of argon plasma
coagulation, mostly in nondysplastic Barrett's esophagus. Significant variations
in technique, end points, and follow-up exist between studies, but in most cases
argon plasma coagulation is associated with unacceptable rates of persistent
intestinal metaplasia and recurrence after completion of treatment. In addition,
serious adverse events including perforation and stricture formation are
reported. Multipolar electrocoagulation has been studied less thoroughly, but in
prospective trials significant rates of persistent and recurrent intestinal
metaplasia have also been reported. Lasers and heater probes have been tried in
small numbers. Endoscopic cryotherapy ablation is a relatively new technique with
studies focusing on high-grade dysplasia and early-stage cancer in high-risk
patients. It has an acceptable safety profile, and early results show response in
a significant number of patients in whom other modalities have failed.
Holmium laser enucleation of the prostate and holmium laser ablation of the prostate: indications and outcome. Suardi N, Gallina A, Salonia A, Briganti A, Dehò F, Zanni G, Abdollah F, Naspro R, Cestari A, Guazzoni G, Rigatti P, Montorsi F. Curr Opin Urol. 2009 Jan;19(1):38-43.
PURPOSE OF REVIEW: Holmium laser enucleation of the prostate (HoLEP) has been
proposed as an alternative to transurethral resection of the prostate and to open
prostatectomy for patients with lower urinary tract symptoms because of large
benign prostatic enlargement. The aim of this review is to critically analyze
currently available evidence-based reports regarding HoLEP, with particular
interest in long-term follow-up results. RECENT FINDINGS: The use of holmium
laser for the treatment of benign prostatic hyperplasia was first reported in
1996. HoLEP seems to represent a valid alternative to both transurethral
resection of the prostate and open prostatectomy, with valid long-term functional
results, a low rate of short-term and long-term complications, and very low rates
of reintervention. SUMMARY: HoLEP represents a valid alternative to both
transurethral resection of the prostate and open prostatectomy for treatment of
patients suffering from lower urinary tract symptoms due to benign prostatic
enlargement. The recently published long-term follow-up data demonstrate the
durability of functional results. HoLEP can be offered as the size-independent
gold standard treatment of patients with lower urinary tract symptoms because of
benign prostatic enlargement.
Systematic review and economic modelling of effectiveness and cost utility of surgical treatments for men with benign prostatic enlargement. Lourenco T, Armstrong N, N'Dow J, Nabi G, Deverill M, Pickard R, Vale L, MacLennan G, Fraser C, McClinton S, Wong S, Coutts A, Mowatt G, Grant A. Health Technol Assess. 2008 Nov;12(35):iii, ix-x, 1-146, 169-515.
OBJECTIVES: To determine the clinical effectiveness and cost utility of
procedures alternative to TURP (transurethral resection of the prostate) for
benign prostatic enlargement (BPE) unresponsive to expectant, non-surgical
treatments. DATA SOURCES: Electronic searches of 13 databases to identify
relevant randomised controlled trials (RCTs). REVIEW METHODS: Two reviewers
independently assessed study quality and extracted data. The International
Prostate Symptom Score/American Urological Association (IPSS/AUA) symptom score
was the primary outcome; others included quality of life, peak urine flow rate
and adverse effects. Cost-effectiveness was assessed using a Markov model
reflecting likely care pathways. RESULTS: 156 reports describing 88 RCTs were
included. Most had fewer than 100 participants (range 12-234). TURP provided
consistent, high-level, long-term symptomatic improvement. Minimally invasive
procedures resulted in less marked improvement. Ablative procedures gave
improvements equivalent to TURP. Holmium laser enucleation of the prostate
(HoLEP) additionally resulted in greater improvement in flow rate. HoLEP is
unique amongst the newer technologies in offering an advantage in urodynamic
outcomes over TURP, although long-term follow-up data are lacking. Severe blood
loss was more common following TURP. Rates of incontinence were similar across
all interventions other than transurethral needle ablation (TUNA) and laser
coagulation, for which lower rates were reported. Acute retention and reoperation
were commoner with newer technologies, especially minimally invasive
interventions. The economic model suggested that minimally invasive procedures
were unlikely to be cost-effective compared with TURP. Transurethral vaporisation
of the prostate (TUVP) was both less costly and less effective than TURP. HoLEP
was estimated to be more cost-effective than a single TURP but less effective
than a strategy involving repeat TURP if necessary. The base-case analysis
suggested an 80% chance that TUVP, followed by HoLEP if required, would be
cost-effective at a threshold of 20,000 pounds per quality-adjusted life-year. At
a 50,000 pounds threshold, TUVP, followed by TURP as required, would be
cost-effective, although considerable uncertainty surrounds this finding. The
main limitations are the quantity and quality of the data available, in the
context of multiple comparisons. CONCLUSIONS: In the absence of strong evidence
in favour of newer methods, the standard--TURP--remains both clinically effective
and cost-effective. There is a need for further research to establish (i) how
many years of medical treatment are necessary to offset the cost of treatment
with a minimally invasive or ablative intervention; (ii) more cost-effective
alternatives to TURP; and (iii) strategies to improve outcomes after TURP.
Laser-assisted management of congenital and acquired pediatric airway disorders: case reports and review of the literature. Ho KH, Ulualp SO. Photomed Laser Surg. 2008 Dec;26(6):601-7.
OBJECTIVES: As laser surgery advances are made in the treatment of adult
disorders, lasers are likewise increasingly being used in the treatment of
pediatric otolaryngologic disorders. We evaluated outcomes of laser surgery in a
group of infants and children with congenital and acquired airway disorders.
MATERIALS AND METHODS: The medical charts of infants and children who were
treated for airway disorders between July 2005 and January 2007 at a tertiary
care children's hospital were reviewed. Data included relevant history and
physical examination, diagnostic work-up, management, and follow-up assessment.
RESULTS: Seven patients who had laser surgery for airway lesions were identified.
Two infants aged 3-12 wk had laryngomalacia, failure to thrive, and apnea. In one
infant, CO(2) laser-assisted supraglottoplasty, in combination with
microlaryngeal scissors, resulted in continuing weight gain in one infant at 15
mo after surgery, and no apnea episodes at 4 wk in the other infant. A
2-month-old infant underwent laser-assisted laryngeal cleft repair. Two patients
diagnosed with recurrent respiratory papillomatosis at age 6-15 mo underwent
multiple CO(2) and KTP laser ablations of laryngotracheal papillomas.
Microdebrider removal of papillomas was initiated due to the large size of the
papillomas. Two patients aged 5-11 y were burn victims with stridor, hoarseness,
or difficulty breathing. After CO(2) ablation of subglottic stenosis and
posterior glottic webs, voice and breathing improved and stridor resolved.
CONCLUSION: Congenital and acquired airway lesions in ;infants and children can
be treated with the laser. A combined approach with other techniques may be
considered to decrease the duration of the procedure when applicable.
Lasers and optical technologies in facial plastic surgery. Wu EC, Wong BJ. Arch Facial Plast Surg. 2008 Nov-Dec;10(6):381-90.
Lasers and optical technologies play a significant role in aesthetic and
reconstructive surgery. The unique ability of optical technologies to target
specific structures and layers in tissues to effect chemical, mechanical, or
thermal changes makes them a powerful tool in cutaneous rejuvenation, hair
removal, fat removal, and treatment of vascular lesions such as port-wine stains,
among many other procedures. With the development of adjunct techniques such as
epidermal cooling, lasers and optical technologies have become more versatile and
safe. The constant improvement of existing applications and the emergence of
novel applications such as photodynamic therapy, nanoparticles, spectroscopy, and
noninvasive imaging continue to revolutionize aesthetic medicine by offering a
minimally invasive alternative to traditional surgery. In the future, therapies
will be based on individualized, maximum, safe radiant exposure to deliver
optimal dosimetry. Lasers and optical technologies are headed toward safer,
easier, more quantifiable, and more individualized therapy.
Clinical and research applications of anterior segment optical coherence tomography - a review. Ramos JL, Li Y, Huang D. Clin Experiment Ophthalmol. 2009 Jan;37(1):81-9. Epub 2008 Nov 5.
Optical coherence tomography (OCT) is being employed more and more often to image
pathologies and surgical anatomy within the anterior segment, specifically in
anterior chamber biometry, corneal pachymetric mapping, angle evaluation and
high-resolution cross-sectional imaging. The cross-sectional imaging capability
of OCT is similar to ultrasound, but its higher resolution allows OCT to measure
and visualize very fine anatomic structures. No contact is required. In this
review, we describe the utility and limitations of anterior segment OCT.
Current status of clinical laser applications in periodontal therapy. Aoki A, Mizutani K, Takasaki AA, Sasaki KM, Nagai S, Schwarz F, Yoshida I, Eguro T, Zeredo JL, Izumi Y. Gen Dent. 2008 Nov-Dec;56(7):674-87; quiz 688-9, 767.
Periodontal disease is a chronic inflammatory disorder caused by bacterial
infection. Laser treatment demonstrates specific characteristics that may be
valuable in managing periodontal disease. In addition, lasers reduce stress and
uncomfortable conditions for patients during and after treatment compared to
other conventional tools. This article reviews the literature to describe the
current clinical applications of lasers for gingival tissue management-including
esthetic treatment, non-surgical and surgical periodontal pocket therapy, osseous
surgery, and implant therapy.
Clinical, morphological, and ultrastructural aspects with the use of Er:YAG and Er,Cr:YSGG lasers in restorative dentistry. Iaria G. Gen Dent. 2008 Nov-Dec;56(7):636-9.
The Er:YAG laser has an active medium of Yttrium-Aluminium-Garnet doped with
Erbium ions and emits free-running pulsed laser energy at a wavelength of 2940
nm. The Er,Cr:YSGG laser has an active medium of Yttrium-Scandium-Gallium-Garnet
doped with Erbium and Chromium ions and emits free-running pulsed laser energy at
a wavelength of 2780 nm. These wavelengths have a high absorption in water, which
makes their application appropriate for ablating oral soft tissue as well as
dental hard tissue. This article examines the principles of use for the Er:YAG
and Er,Cr:YSGG lasers in clinical restorative dentistry and reviews the
literature regarding different aspects of the use of laser energy on hard
The use of lasers in periodontal therapy. Coleton S. Gen Dent. 2008 Nov-Dec;56(7):612-6.
In the same way that new, more advanced surgical procedures such as implant
placement and sinus augmentation have allowed periodontal surgeons to restore the
dental health of patients who, until now, have been destined for a lifetime of
complete dentures, the laser has provided dentists with the instrument needed to
produce an essentially bloodless and bacteria-free surgical field, allowing for
deeper surgical procedures within the oro-nasal cavity. The article is meant to
help dentists determine which lasers are suitable for various periodontal
Eating disorders part II: clinical strategies for dental treatment. Aranha AC, Eduardo Cde P, Cordás TA.
J Contemp Dent Pract. 2008 Nov 1;9(7):89-96.
AIM: To present the strategies of treatment for dental implications of eating
disorders. METHODS AND MATERIALS: A comprehensive review of the literature was
conducted with special emphasis on the treatment of the oral implications of
anorexia nervosa and bulimia nervosa, dividing the treatment into different
parts. RESULTS: Oral manifestations of eating disorders represent a challenge to
the dental practitioner. Dental erosion, caries, xerostomia, enlargement of
parotide glands, traumatized oral mucosa, and other oral manifestations may
present in anorexic and bulimic patients. CONCLUSION: Often the dentist is the
first healthcare provider to observe the clinical symptoms of an eating disorder.
Dental treatment should be carried out simultaneously with the medical treatment.
However, dentists are not aware of the fundamental importance of the dentist's
participation in the multidisciplinary treatment and no training is provided with
regard to the strategies involved in the dental treatment. CLINICAL SIGNIFICANCE:
Oral complications of eating disorders are a major concern. The difficulties of
recognizing the oral manifestations, and the failure to do so, may lead to
serious systemic problems in addition to progressive and irreversible damage to
the oral hard tissues. Considering the increasing incidence and prevalence rates
of eating disorders, the dentist's participation and dental treatment should be
Fire safety in the operating room. Rinder CS. Curr Opin Anaesthesiol. 2008 Dec;21(6):790-5.
PURPOSE OF REVIEW: Elimination of flammable anesthetic gases has had little
effect on operating-room fires except to change their etiology. Electrocautery
and lasers, in an oxygen-enriched environment, can ignite even the most
fire-resistant materials, including the patient, and the fire triad possibilities
in the operating room are nearly limitless. This review will: identify operating
room contents capable of acting as ignition/oxidizer/fuel sources, highlight
operating room items that are uniquely potent fire triad contributors, and
operating room identify settings where fire risk is enhanced by proximity of
triad components in time or space. RECENT FINDINGS: Anesthesiologists are
cognizant of the risk of airway surgery fires due to laser ignition of the
endotracheal tube and/or its contents. Recently, however, head/neck surgery under
monitored anesthesia care has emerged as a high-risk setting for operating room
fires; burn injuries represent 20% of monitored anesthesia care-related
malpractice claims, 95% of which involved head/neck surgery. SUMMARY: Operating
room fires are infrequent but catastrophic. Operating room fire prevention
depends on: (a)understanding how fire triad elements interact to create a fire,
(b) recognizing how standard operating-room equipment, materials, and
supplemental oxygen can become one of those elements, and (c) vigilance for
circumstances that bring fire triad elements into close proximity.
Laser capture microdissection of mammalian tissue. Edwards RA. J Vis Exp. 2007;(8):309. Epub 2007 Oct 1.
Laser capture microscopy, also known as laser microdissection (LMD), enables the
user to isolate small numbers of cells or tissues from frozen or formalin-fixed,
paraffin-embedded tissue sections. LMD techniques rely on a thermo labile
membrane placed either on top of, or underneath, the tissue section. In one
method, focused laser energy is used to melt the membrane onto the underlying
cells, which can then be lifted out of the tissue section. In the other, the
laser energy vaporizes the foil along a path "drawn" on the tissue, allowing the
selected cells to fall into a collection device. Each technique allows the
selection of cells with a minimum resolution of several microns. DNA, RNA,
protein, and lipid samples may be isolated and analyzed from micro-dissected
samples. In this video, we demonstrate the use of the Leica AS-LMD laser
microdissection instrument in seven segments, including an introduction to the
principles of LMD, initializing the instrument for use, general considerations
for sample preparation, mounting the specimen and setting up capture tubes,
aligning the microscope, adjusting the capture controls, and capturing tissue
specimens. Laser-capture micro-dissection enables the investigator to isolate
samples of pure cell populations as small as a few cell-equivalents. This allows
the analysis of cells of interest that are free of neighboring contaminants,
which may confound experimental results.
Laser-induced chronic ocular hypertension model on SD rats. Chiu K, Chang R, So KF. J Vis Exp. 2007;(10):549. Epub 2007 Dec 4.
Glaucoma is one of the major causes of blindness in the world. Elevated
intraocular pressure is a major risk factor. Laser photocoagulation induced
ocular hypertension is one of the well established animal models. This video
demonstrates how to induce ocular hypertension by Argon laser photocoagulation in
Pregnancy management after cervical surgery. Jolley JA, Wing DA. Curr Opin Obstet Gynecol. 2008 Dec;20(6):528-33.
PURPOSE OF REVIEW: An amplified risk of adverse pregnancy outcomes after
excisional cervical surgery has been identified. Procedures such as cold-knife
conization, laser conization, loop electrosurgical excision procedure, and
trachelectomy increase the risk of preterm delivery and preterm premature rupture
of membranes. Few studies have evaluated prenatal care considerations after these
procedures. This review discusses pregnancy management after cervical surgery.
RECENT FINDINGS: Data showing an association between excisional and ablative
procedures of the cervix and subsequent preterm delivery or preterm premature
rupture of membranes are increasing and include more recent information from
larger case series and meta-analyses. The need for appropriate and evidence-based
management strategies during subsequent pregnancy has arisen. Screening for
genital tract infection, sonographic cervical length surveillance, and
progesterone administration for cervical shortening may lead to improved
pregnancy outcomes in women at high risk for preterm delivery, including women
who have undergone cervical surgery. Modifiable risk factors such as depth of
conization and procedure-to-pregnancy time interval should be recognized and
clinicians should avoid overtreatment for preinvasive cervical lesions. SUMMARY:
A number of procedures performed for a variety of indications can be considered
excisional cervical surgery. As a result, no standard recommendations for
pregnancy management following cervical surgery exist. Given the increased risk
of pregnancy complications, certain screening tests or interventions may be
appropriate for these women.
Quantitative analysis in medicine using photoacoustic tomography. Haisch C. Anal Bioanal Chem. 2009 Jan;393(2):473-9. Epub 2008 Nov 5.
Photoacoustic imaging, or photoacoustic tomography, is a 2D or 3D optical imaging
method based on localized optical absorption of pulsed laser radiation. By a
spatially resolved detection of the following thermoelastic expansion, the local
distribution of the absorption can be determined. The technique has been proven
to have significant potential for the imaging of human and animal organs and
single blood vessels, combining high contrast with good spatial resolution. The
contrast is based on the specific optical absorption of certain components in the
visible and near-infrared spectral range, for most applications of blood.
Generally, the images represent the local distribution of blood in a qualitative
or semiquantitative way. Although photoacoustic imaging is capable of revealing
absolute and spatially resolved concentrations of endogenous (such as
oxyhemoglobin and deoxyhemoglobin) or artificial (such as tumor markers)
chromophores, only a very limited number of publications have dealt with this
demanding task. In this report, the problems involved and possible solutions are
reviewed and summarized.
Enhancing the nail permeability of topically applied drugs. Murdan S. Expert Opin Drug Deliv. 2008 Nov;5(11):1267-82.
The topical therapy of nail diseases, especially of onychomycosis, and to a
smaller extent, of nail psoriasis, is desirable to avoid the side effects
associated with their systemic therapy, to increase patient compliance and reduce
the cost of treatment. Systemic therapy is however the mainstay of treatment due
to the poor permeability of the nail plate to topically applied drugs. For
effective topical therapy, ungual drug permeation must be enhanced. This can be
achieved by disrupting the nail plate using physical techniques or chemical
agents. Alternatively, drug permeation into the intact nail plate may be
encouraged, for example, by iontophoresis or by formulating the drug within a
vehicle which enables high drug partition out of the vehicle and into the nail
plate. The physical techniques (manual and electrical nail abrasion, acid
etching, ablation by lasers, microporation, application of low-frequency
ultrasound and electric currents) and chemicals (thiols, sulphites, hydrogen
peroxide, urea, water, enzymes) that have shown ungual enhancer activity are
discussed in this review. Optimal drug formulation, while crucial to ungual drug
delivery, is only briefly reviewed due to the limited literature.
Photodynamic therapy in skin rejuvenation. Goldberg DJ. Clin Dermatol. 2008 Nov-Dec;26(6):608-13.
Photodynamic therapy is a noninvasive technique used in the treatment of various
skin disorders. This article will provide readers with an extensive review of the
popular chosen topical photosensitizers, varied used light sources and lasers,
and medical and cosmetic indications treated with photodynamic therapy.
Laser: a review. Rinaldi F. Clin Dermatol. 2008 Nov-Dec;26(6):590-601.
Lasers and light-based treatments are extremely useful and now standardized
techniques in the management of different stages of photoaging. To obtain the
most successful results, protocols involving single or combination systems can be
used, depending on skin photodamage. In the last years, the trend is to choose
noninvasive or minimally invasive treatments, with the aim of reducing the risk
of side effects, complications, and downtime. Selective photothermolysis obtained
with lasers and with intense pulse light, which is presently considered the most
suitable technique by a growing number of authors, is an extremely valid
procedure, in particular in types I and II, according to the Glogau
classification. Photodynamic therapy is another effective tool in photoaging
treatment, especially in the presence of precancerous conditions. In mild and
severe photoaging, ablative laser resurfacing is a particularly successful
technique, although requiring a very skilled hand. The new systems, such as
fractional photothermolysis, seem to be the very next future to face up to
resurfacing procedure with high efficacy and less risks. Obviously, lasers and
light-based treatments alone might not be sufficient to control all aging
symptoms. For this reason, any another treatment (botulinum toxin, filling
agents, chemical peels, systemic and topic antioxidants) can be used in
combination to improve the final clinical outcome.
Technology-enhanced caries detection and diagnosis. Strassler HE, Sensi LG. Compend Contin Educ Dent. 2008 Oct;29(8):464-5, 468, 470 passim.
The prevalence of dental caries in children and adults in the United States has
been declining the past 40 years primarily because of increased use of fluoride,
improved oral hygiene and better oral hygiene devices, a greater emphasis on
disease prevention and control, and better access to dental care made available
by the dental profession. Caries diagnosis and detection for pit-and-fissure
lesions has changed dramatically in the past 25 years. Research has confirmed
that the carious process is bacterially mediated and is accompanied by changes in
salivary flow and pH and the intake of refined carbohydrates. In recent years a
number of new technologies have become available as adjuncts to traditional
methods of diagnosing carious lesions. While using these new technologies, the
clinician still needs to understand the concepts of caries risk, diagnosis,
detection, and assessment. Working from the evidence, dental practitioners can
decide on a sound clinical diagnosis and treatment plan.
Dental laser technology. Fasbinder DJ. Compend Contin Educ Dent. 2008 Oct;29(8):452-4, 456, 458-9; quiz 460, 462.
Dental technology is rapidly affecting the treatment options available to
patients. Dental lasers are an innovative technology for both hard- and
soft-tissue treatment applications. The ability to recontour soft tissues
efficiently and predictably with immediate hemostatsis and minimal postoperative
sequelae is of value to both the dentist and the patient. This article reviews
the principles of dental lasers, criteria to consider when selecting a dental
laser, and some of their clinical applications.
Femtosecond lasers in ophthalmology. Soong HK, Malta JB. Am J Ophthalmol. 2009 Feb;147(2):189-197.e2. Epub 2008 Oct 18.
PURPOSE: To provide an update and review of femtosecond (FS) lasers in clinical
ophthalmology. DESIGN: Perspective, literature review, and commentary. METHODS:
Selected articles from the literature and the authors' clinical and laboratory
studies. RESULTS: The FS laser employs near-infrared pulses to cut tissue with
minimal collateral tissue damage. Although its major use at present is in the
cutting of laser in situ keratomileusis flaps, the laser has proven its
versatility in laser-assisted anterior and posterior lamellar keratoplasty,
cutting of donor buttons in endothelial keratoplasty, customized trephination in
penetrating keratoplasty, tunnel creation for intracorneal ring segments,
astigmatic keratotomy, and corneal biopsy. Current laboratory studies include
all-FS laser refractive keratomileusis sans flap, cutting corneal pockets for
insertion of biopolymer keratoprostheses, noninvasive transscleral glaucoma
surgery, retinal imaging and photodisruption, presbyopia surgery, and anterior
lens capsulorrhexis. CONCLUSIONS: Advances in ultra-fast laser technology
continue to improve the surgical safety, efficiency, speed, and versatility of FS
lasers in ophthalmology.
Chemical calcium indicators. Paredes RM, Etzler JC, Watts LT, Zheng W, Lechleiter JD. Methods. 2008 Nov;46(3):143-51. Epub 2008 Oct 16.
Our understanding of the underlying mechanisms of Ca2+ signaling as well as our
appreciation for its ubiquitous role in cellular processes has been rapidly
advanced, in large part, due to the development of fluorescent Ca2+ indicators.
In this chapter, we discuss some of the most common chemical Ca2+ indicators that
are widely used for the investigation of intracellular Ca2+ signaling.
Advantages, limitations and relevant procedures will be presented for each dye
including their spectral qualities, dissociation constants, chemical forms,
loading methods and equipment for optimal imaging. Chemical indicators now
available allow for intracellular Ca2+ detection over a very large range (<50 nM
to >50 microM). High affinity indicators can be used to quantify Ca2+ levels in
the cytosol while lower affinity indicators can be optimized for measuring Ca2+
in subcellular compartments with higher concentrations. Indicators can be
classified into either single wavelength or ratiometric dyes. Both classes
require specific lasers, filters, and/or detection methods that are dependent
upon their spectral properties and both classes have advantages and limitations.
Single wavelength indicators are generally very bright and optimal for Ca2+
detection when more than one fluorophore is being imaged. Ratiometric indicators
can be calibrated very precisely and they minimize the most common problems
associated with chemical Ca2+ indicators including uneven dye loading, leakage,
photobleaching, and changes in cell volume. Recent technical advances that permit
in vivo Ca2+ measurements will also be discussed.
Assessment of neuroprotection in the retina with DARC. Guo L, Cordeiro MF. Prog Brain Res. 2008;173:437-50.
Currently, assessment of new drug efficacy in glaucoma relies on conventional
perimetry to monitor visual field changes. However, visual field defects cannot
be detected until 20-40% of retinal ganglion cells (RGCs), the key cells
implicated in the development of irreversible blindness in glaucoma, have been
lost. We have recently developed a new, noninvasive real-time imaging technology,
which is named DARC (detection of apoptosing retinal cells), to visualize single
RGC undergoing apoptosis, the earliest sign of glaucoma. Utilizing fluorescently
labeled annexin 5 and confocal laser scanning ophthalmoscopy, DARC enables
evaluation of treatment effectiveness by monitoring RGC apoptosis in the same
living eye over time. Using DARC, we have assessed different neuroprotective
therapies in glaucoma-related animal models and demonstrated DARC to be a useful
tool in screening neuroprotective strategies. DARC will potentially provide a
meaningful clinical end point that is based on the direct assessment of the RGC
death process, not only being useful in assessing treatment efficacy, but also
leading to the early identification of patients with glaucoma. Clinical trials of
DARC in glaucoma patients are due to start in 2008.
Physical means of treating unwanted hair. Wanitphakdeedecha R, Alster TS. Dermatol Ther. 2008 Sep-Oct;21(5):392-401.
Unwanted facial and body hair is a common problem, generating a high level of
interest for treatment innovations. A wide range of modalities for the management
of unwanted hair have been advocated over the years with varying degrees of
clinical success. Most recently, lasers and light sources have been used to
address this problem with improved clinical success rates in properly selected
patients. The full range of temporary and permanent hair removal techniques will
be outlined in this review of physical means of treating unwanted hair.
308 nm monochromatic excimer light in dermatology: personal experience and review of the literature. Mavilia L, Mori M, Rossi R, Campolmi P, Puglisi Guerra A, Lotti T. G Ital Dermatol Venereol. 2008 Oct;143(5):329-37.
For over five years, we have been using a new ultraviolet B ray source, a
Xenon-Chloride lamp emitting non-coherent, monochromatic 308-nm light that
represents the natural evolution of the excimer laser. A source of monochromatic
excimer light (MEL) produces 50 mW/cm(2) power density at a distance of 15 cm
from the source and has a maximum irradiating area of 504 cm(2), this feature
representing the greatest therapeutic advantage offered by 308 nm sources. On the
other hand, the benefits offered by the MEL compared to traditional
phototherapies are essentially correlated to the fact that there is no need to
administer oral psoralens (PUVA therapy) and that sessions need to be repeated
only every 7-15 days, an important condition for the improvement of the patient’s
quality of life (since at least 2-3 weekly sessions are required with the
traditional UVB therapy). Using MEL, UV B light can be applied on the entire
body, with partial subintrant skin irradiations, or on one or just a few
individual patches, taking care to accurately protect the healthy surrounding
skin and allowing for a phototherapy exclusively targeted onto the lesion to be
treated. Clinical indications and the reasons for choosing MEL for the treatment
of photosensitive skin disorders are virtually identical to those stated for PUVA
therapy or narrowband UV B light. Due to the absence of photosensitizing
substances and drug-induced toxicity, patients who work in the open air, pregnant
women and patients suffering from liver or kidney failure can also be treated.
Furthermore, the short time required for sessions, the duration of cycles and the
selective exposure of the skin areas to be treated undoubtedly represent
significant benefits for patients in terms of safety and efficacy. In addition to
psoriasis, the use of MEL can also be extended to other pathologies such as
vitiligo, alopecia areata, atopic dermatitis and patch-stage IA mycosis fungoides
with encouraging RESULTS:
Tissue proteomics for cancer biomarker development: laser microdissection and 2D-DIGE. Kondo T. BMB Rep. 2008 Sep 30;41(9):626-34.
Novel cancer biomarkers are required to achieve early diagnosis and optimized
therapy for individual patients. Cancer is a disease of the genome, and tumor
tissues are a rich source of cancer biomarkers as they contain the functional
translation of the genome, namely the proteome. Investigation of the tumor tissue
proteome allows the identification of proteomic signatures corresponding to
clinico-pathological parameters, and individual proteins in such signatures will
be good biomarker candidates. Tumor tissues are also a rich source for plasma
biomarkers, because proteins released from tumor tissues may be more cancer
specific than those from non-tumor cells. Two-dimensional difference gel
electrophoresis (2D-DIGE) with novel ultra high sensitive fluorescent dyes (CyDye
DIGE Fluor satulation dye) enables the efficient protein expression profiling of
laser-microdissected tissue samples. The combined use of laser microdissection
allows accurate proteomic profiling of specific cells in tumor tissues. To
develop clinical applications using the identified biomarkers, collaboration
between research scientists, clinicians and diagnostic companies is essential,
particularly in the early phases of the biomarker development projects. The
proteomics modalities currently available have the potential to lead to the
development of clinical applications, and channeling the wealth of produced
information towards concrete and specific clinical purposes is urgent.
Endovenous laser ablation: mechanism of action. Fan CM, Rox-Anderson R. Phlebology. 2008;23(5):206-13.
OBJECTIVES: The objective of this study is to review the basics of laser and
established tissue response patterns to thermal injury, with specific reference
to endovenous laser ablation (EVLA). This study also reviews the current theories
and supporting aspects for the mechanism of action of EVLA in the treatment of
superficial venous reflux. METHODS: The method involves the review of published
literature and original investigation of histological effects of 810 nm and 980
nm wavelength EVLA on explanted blood-filled bovine saphenous vein in an in vitro
system. RESULTS: The existing histological reports confirm that EVLA produces a
transmural vein wall injury, typically associated with perforations and
carbonization. The pattern of injury is eccentrically distributed, with maximum
injury occurring along the path of laser contact. Intravenous temperature
monitoring studies during EVLA have confirmed that the peak temperatures at the
fibre tip exceed 1000 degrees C, and continuous temperatures of at least 300
degrees C are maintained in the firing zone for the majority of the procedure.
Steam production during EVLA, which occurs early in the photothermolytic process
when temperatures reach 100 degrees C, accounts for only 2% of applied energy
dose, and is therefore unlikely to be the primary mechanism of action of thermal
injury during the procedure. CONCLUSION: EVLA causes permanent vein closure
through a high-temperature photothermolytic process at the point of contact
between the vein and the laser.
Advances in technologies for the measurement of uranium in diverse matrices. Rathore DP. Talanta. 2008 Oct 19;77(1):9-20. Epub 2008 Jun 25.
An overview of the advances in technologies, which can be used in the field as
well as in a laboratory for the measurement of uranium in diverse matrices like,
waters, minerals, mineralized rocks, and other beneficiation products for its
exploration and processing industries is presented. Laser based technologies, ion
chromatography, microsample X-ray analysis method followed by energy dispersive
X-ray fluorescence technique (MXA-EDXRF), sensors for electrochemical detection
followed by cyclic voltammogram and alpha liquid scintillation counting
techniques are the most promising techniques. Among these techniques, laser
fluorimetry/spectrofluorimetry, in particular, is the technique of choice because
of its high performance qualification (PQ), inherent sensitivity, simplicity,
cost effectiveness, minimum generation of analytical waste, rapidity, easy
calibration and operation. It also fulfills the basic essential requirements of
reliability, applicability and practicability (RAPs) for the analysis of uranium
in solution of diverse matrices in entire nuclear fuel cycle. A very extensive
range of uranium concentrations may be covered. Laser fluorimetry is suitable for
direct determination of uranium in natural water systems within the microg L(-1)
and mg L(-1) range while differential technique in laser fluorimetry (DT-LIF) is
suitable for mineralized rocks and concentrates independent of matrix effects
(uranium in samples containing >0.01% uranium). The most interesting feature of
TRLIF is its capability of performing speciation of complexes directly in
solution as well as remote determination via fiber optics and optrode. Future
trend and advances in lasers, miniaturization and automation via flow injection
analysis (FIA) has been discussed.
[Laser therapy for benign prostate hyperplasia] [Article in German] Muschter R. Aktuelle Urol. 2008 Sep;39(5):359-68. Epub 2008 Sep 16.
Various procedures operating with different laser systems and application
techniques are available for laser treatment of benign prostate hyperplasia
(BPH). They generate differing qualitative and quantitative effects in tissue
such as coagulation, vaporisation or, respectively, ablation as well as incisions
leading according to technique to a resection or enucleation. Since these
procedures are considered as alternatives to transurethral resection of the
prostate (TURP), the objective of laser therapy is not only to achieve, in
comparison to TURP, an equivalent improvement of the symptoms and quality of life
but also a maximal urinary flow strength or, respectively, a reduction of
obstruction to bladder emptying with lower accompanying morbidity and shorter
hospitalisation. Most of the published case control and randomised studies on
laser therapy for BPH show heterogeneous results both with regard to the
improvement of subjective and objective urination parameters as well to
complications. This is due, on the one hand, to the laser or its qualitative
action and, on the other hand, to the operator and the resulting specific
quantitative effect. The biophysical relationships between the laser parameters
and the tissue effects are a topic of current discussion. The biological effect
depends not only on the depth of penetration and the scattering but also on other
parameters of the laser. For the generation of voluminous coagulation necrosis
with a laser in the ca. 800 to 1100 nm wavelength region, a carbonisation of the
surface must be avoided. For thermal vaporisation, for example, the Nd:YAG laser
with contract-free application or contact tips as well as diode lasers of varying
wavelengths are suitable. Especially suitable are the potassium titanyl phosphate
(KTP) laser and the lithium triboride (LBO) laser. Ablation is also possible with
the Ho:YAG laser. An incision and thus resection or enucleation is also possible
with various laser systems including thermal ones, but is more effective with a
continuous beam laser of ca. 2000 nm. The Ho:YAG laser achieves an athermal
incision the quality of which depends on the pulse energy and the time behaviour
of the laser impulse.
Selective laser trabeculoplasty: a review. Realini T. J Glaucoma. 2008 Sep;17(6):497-502.
The introduction of selective laser trabeculoplasty (SLT) has renewed interest in
laser trabeculoplasty for the reduction of intraocular pressure (IOP) in eyes
with glaucoma. This review was undertaken to address frequently raised issues
pertinent to SLT in clinical practice. On the basis of the peer-reviewed medical
literature, SLT demonstrates equivalent efficacy and comparable safety to argon
laser trabeculoplasty, and is also equally as effective as topical medical
therapy. SLT’s safety profile includes mild and transient inflammation, ocular
pain, and a small risk of moderate IOP elevations after the procedure. The
mechanism of action of SLT is not known. SLT delivers less energy to the
trabecular meshwork and generates less damage to angle tissues. Whether this
renders SLT more repeatable than argon laser trabeculoplasty has not been
evaluated in published data. SLT seems to be a safe and effective means of IOP
reduction in eyes with glaucoma, and can reasonably be applied as primary or
Advances in plasma skin regeneration. Foster KW, Moy RL, Fincher EF. J Cosmet Dermatol. 2008 Sep;7(3):169-79.
Plasma skin regeneration (PSR) is a novel method of resurfacing that uses plasma
energy to create a thermal effect on the skin. PSR is different from lasers,
light sources, and ablative lasers in that it is not chromophore dependent and
does not vaporize tissue, but leaves a layer of intact, desiccated epidermis that
acts as a natural biologic dressing and promotes wound healing and rapid
recovery. Histological studies performed on plasma resurfacing patients have
confirmed continued collagen production, reduction of elastosis, and progressive
skin rejuvenation beyond 1 year after treatment. PSR has received US Food and
Drug Administration 510 (k) clearance for treatment of rhytides of the body,
superficial skin lesions, actinic keratoses, viral papillomata, and seborrheic
keratoses. PSR also has beneficial effects in the treatment of other conditions
including dyschromias, photoaging, skin laxity, and acne scars. The safety
profile of PSR is excellent, and there have been no reports of demarcation lines
in perioral, periorbital, or jawline areas, as can sometimes be observed
following CO2 resurfacing. PSR is effective in improving facial and periorbital
rhytides and can be used on nonfacial sites, including the hands, neck, and
chest. Numerous treatment protocols with variable energy settings allow for
individualized treatments and provide the operator with fine control over the
degree of injury and length of subsequent recovery time.
Laser photorejuvenation of Asian and ethnic skin. Izikson L. J Cosmet Laser Ther. 2008 Sep;10(3):161-6.
Laser therapy of Asian and ethnic skin has been relatively poorly studied in the
literature. Owing to particular physiologic aspects of darker skin, the physical
properties of currently available lasers, and the nature of laser-tissue
interactions, the use of lasers to treat chronological and photodamage in such
patients may be challenging and fraught with complications. Nevertheless, both
ablative and non-ablative technologies have been used successfully to address
various cosmetic concerns. This article is a review of skin physiology and
laser-tissue interactions in Asian and ethnic skin, particular aesthetic concerns
and medical pre- and postoperative considerations in such patients, and a summary
of the past 20 years of experience with ablative and non-ablative technologies
for effective and safe photorejuvenation.
Evidence for laser- and light-based treatment of acne vulgaris. Munavalli GS, Weiss RA. Semin Cutan Med Surg. 2008 Sep;27(3):207-11.
Dermatology, Laser, and Vein Specialists of the Carolinas, Charlotte, NC 28207,
Acne is a very prevalent skin disorder, affecting more than 85% of adolescents
and often continuing into adulthood. Active acne and its sequelae, especially
permanent scarring, may cause longstanding psychological or emotional harm in
patients. Novel and promising treatments with laser/light devices (such as blue
light, red light, pulsed dye laser, infrared lasers, light-emitting diodes, and
pulsed light) have been reported to have varying degrees of efficacy for
treatment. The authors compiled a summary of evidence-based literature on
laser/light treatment for acne to assist clinicians to more appropriately
identify treatment options, should they choose to supplement current medical
Decreasing systemic toxicity via transdermal delivery of anticancer drugs. Fang JY, Liu PF, Huang CM. Curr Drug Metab. 2008 Sep;9(7):592-7.
When used at a high dose, many anticancer drugs produce undesirable side effects
including hepatotoxicity. Transdermal delivery bypasses first-pass metabolism,
allowing the use of a lower dose of drug while decreasing systemic toxicity. In
this review, we summarize various advanced technologies for improving anticancer
drug delivery via the skin. This technology is discussed in the context of three
anticancer drugs, 5-fluorouracil (5-FU), methotrexate (MTX) and 5-aminolevulinic
acid (5-ALA). The use of a erbium:YAG (Er:YAG) laser for transdermal delivery of
anticancer drugs is specifically highlighted in this review.
Application of high pressure laser flash photolysis in studies on selected hemoprotein reactions. Brindell M, Stawoska I, Orzeł L, Labuz P, Stochel G, van Eldik R. Biochim Biophys Acta. 2008 Nov;1784(11):1481-92. Epub 2008 Aug 20.
This article focuses on the application of high pressure laser flash photolysis
for studies on selected hemoprotein reactions with the objective to establish
details of the underlying reaction mechanisms. In this context, particular
attention is given to the reactions of small molecules such as dioxygen, carbon
monoxide, and nitric oxide with selected hemoproteins (hemoglobin, myoglobin,
neuroglobin and cytochrome P450(cam)), as well as to photo-induced electron
transfer reactions occurring in hemoproteins (particularly in various types of
cytochromes). Mechanistic conclusions based on the interpretation of the obtained
activation volumes are discussed in this account.
Surgical treatment of peri-implantitis. Claffey N, Clarke E, Polyzois I, Renvert S. J Clin Periodontol. 2008 Sep;35(8 Suppl):316-32.
OBJECTIVES: To review the literature on surgical treatment of peri-implantitis.
MATERIAL AND METHODS: A search of PubMed and as well as a hand search of articles
were conducted. Publications and articles accepted for publication up to November
2007 were included. RESULTS: A total of 43 studies were selected for the review.
Only 13 of these were studies in humans and only one study directly addressed
disease resolution. Thus the available evidence for surgical treatment of
peri-implantitis is extremely limited. ANIMAL STUDIES: Re-osseointegration can
occur on previously contaminated surfaces. The surface characteristics are
decisive for regeneration and re-osseointegration. No single surface
decontamination method appears to be distinctly superior. Open debridement with
surface decontamination can achieve resolution. HUMAN STUDIES: Access surgery has
been investigated in one study demonstrating that resolution occurred in 58% of
the lesions. No single method of surface decontamination (chemical agents, air
abrasives and lasers) was found to be superior. The use of regenerative
procedures such as bone graft techniques with or without the use of barrier
membranes has been reported with various degrees of success. However, it must be
stressed that such techniques do not address disease resolution but rather merely
attempt to fill the osseous defect.
Laser application in non-surgical periodontal therapy: a systematic review. Schwarz F, Aoki A, Becker J, Sculean A. J Clin Periodontol. 2008 Sep;35(8 Suppl):29-44.
OBJECTIVES: The primary aim was to address the following focused question: What
is the clinical effect of laser application compared with mechanical debridement
in non-surgical periodontal therapy in patients with chronic periodontitis? A
secondary aim was to survey the relevant literature in relation to safety of
laser applications. MATERIAL AND METHODS: Electronic databases of the PubMed and
the Cochrane Library were searched and completed by manual searches up to
December 2007. RESULTS: Following screening, 12 publications (11 studies) were
eligible for the review. A meta-analysis could not be performed due to the
heterogeneity of the studies. The results from a narrative synthesis indicate
that Er:YAG laser monotherapy resulted in similar clinical outcomes, both in the
short and the long term (up to 24 months), compared with mechanical debridement.
There is insufficient evidence to support the clinical application of either
CO(2), Nd:YAG, Nd:YAP, or different diode laser wavelengths. CONCLUSIONS: The
Er:YAG laser seems to possess characteristics most suitable for the non-surgical
treatment of chronic periodontitis. Research conducted so far has indicated that
its safety and effects might be expected to be within the range reported for
conventional mechanical debridement. However, the evidence from the evaluated
studies is weak.
Laser-evoked potentials in primary headaches and cranial neuralgias. de Tommaso M. Expert Rev Neurother. 2008 Sep;8(9):1339-45.
Using neurophysiological methods to explore nociceptive pathways may improve
knowledge of the functional changes subtending pain processing in the different
forms of headache and facial pain. Laser-evoked potentials (LEPs) are a reliable
neurophysiological assay for the clinical assessment of pain syndromes. Reduced
amplitude of LEPs seems to characterize trigeminal neuralgia and painful
temporomandibular disorders, suggesting the neuropathic origin of pain. In
tension-type headache, as well as in fibromyalgia, enhanced pericranial LEP
amplitude suggests the psychogenic origin of pain. In migraine, a normal
amplitude of basal LEPs with reduced habituation and altered attentive modulation
seems to express a general dysfunction of cortical pain processing, which may
also contribute, other than to predispose, to the persistence of migraine. LEPs
may be employed in the clinical evaluation of the neurophysiological and
psychophysiological aspects of pain in the different forms of headaches and
facial pain to improve the therapeutic approach and provide an objective measure
of treatment efficacy.
[Laser procedures for fistular formation in different modes of dacryocystorhinostomy] [Article in Russian] Iusipova ER, Davydov DV, At’kova EL. Vestn Oftalmol. 2008 Jul-Aug;124(4):56-8.
Time-resolved methods in biophysics. 7. Photon counting vs. analog time-resolved singlet oxygen phosphorescence detection. Jiménez-Banzo A, Ragàs X, Kapusta P, Nonell S. Photochem Photobiol Sci. 2008 Sep;7(9):1003-10. Epub 2008 Jun 25.
Two recent advances in optoelectronics, namely novel near-IR sensitive
photomultipliers and inexpensive yet powerful diode-pumped solid-state lasers
working at kHz repetition rate, enable the time-resolved detection of singlet
oxygen (O2(a1Deltag)) phosphorescence in photon counting mode, thereby boosting
the time-resolution, sensitivity, and dynamic range of this well-established
detection technique. Principles underlying this novel approach and selected
examples of applications are provided in this perspective, which illustrate the
advantages over the conventional analog detection mode.
Research Support, Non-U.S. Gov’t
PMID: 18754045 [PubMed - indexed for MEDLINE]
81: Anal Bioanal Chem. 2009 Jan;393(1):51-6. Epub 2008 Aug 22.
Optimal coherent control of sensitivity and selectivity in spectrochemical
Los Alamos National Laboratory, Los Alamos, NM 87545, USA. email@example.com
The number and breadth of coherently controlled chemical processes are escalating
exponentially since the recent convergence of stable broadband ultrafast laser
sources, robust pulse shaping devices, and closed-loop optimization routines. We
show here how these methods can also be applied to spectrochemical analysis. We
discuss the basics of optimal coherent control and describe their use, both
present and future, to enhance the sensitivity and/or selectivity of several
different spectroscopic analytical methods.
308-nm excimer laser in psoriasis vulgaris, scalp psoriasis, and palmoplantar psoriasis. Gattu S, Rashid RM, Wu JJ. J Eur Acad Dermatol Venereol. 2009 Jan;23(1):36-41. Epub 2008 Aug 19.
BACKGROUND: The 308-nm excimer laser is a recent development in the treatment of
psoriasis vulgaris, palmoplantar psoriasis, and psoriasis of the scalp. The XeCl
excimer emits a 308-nm wavelength beam of light that is monochromatic and
coherent. These properties allow selectivity when used as phototherapy against a
psoriatic lesion while sparing healthy surrounding tissue. OBJECTIVE: In this
manuscript, we review recent updates on the efficacy of excimer and its most
recent trials in psoriasis. METHODS: A review of the medical literature in Pubmed
database was performed using the terms ‘psoriasis’ and ’308 nm excimer laser’.
All trials to date that studied the 308-nm excimer including those that compared
the excimer with other modalities were included. RESULTS: Eighteen trials show
positive results surrounding the efficacy of the excimer. Selectivity of the
308-nm excimer, when compared with non-selective narrowband UVB (NB-UVB)
phototherapy allows one to adjust the fluency to the lesion. The excimer may also
stand superior to NB-UVB in its efficacy of mechanism. CONCLUSION: Excimer is a
useful and effective treatment for psoriasis that may be used as a compliment to
topical medications as well as NB-UVB. However, large randomized trials with
long-term follow-up are needed to further support this.
Chromophore-assisted laser inactivation in cell biology. Jacobson K, Rajfur Z, Vitriol E, Hahn K. Trends Cell Biol. 2008 Sep;18(9):443-50. Epub 2008 Aug 14.
Chromophore-assisted laser inactivation (CALI) is a technique whereby engineered
proteins and dye molecules that produce substantial amounts of reactive oxygen
species upon absorption of light are used to perturb biological systems in a
spatially and temporally defined manner. CALI is an important complement to
conventional genetic and pharmacological manipulations. In this review, we
examine the applications of CALI to cell biology and discuss the underlying
photochemical mechanisms that mediate this powerful technique.
Pathophysiological and pharmacological implications of mitochondria-targeted reactive oxygen species generation in astrocytes. Jou MJ. Adv Drug Deliv Rev. 2008 Oct-Nov;60(13-14):1512-26. Epub 2008 Jul 5.
Astrocytes, in addition to passively supporting neurons, have recently been shown
to be actively involved in synaptic transmission and neurovascular coupling in
the central nervous system (CNS). This review summarizes briefly our previous
observations using fluorescent probes coupled with laser scanning digital imaging
microscopy to visualize spatio-temporal alteration of mitochondrial reactive
oxygen species (mROS) generation in intact astrocytes. mROS formation is enhanced
by exogenous oxidants exposure, Ca2+ stress and endogenous pathological defect of
mitochondrial respiratory complexes. In addition, mROS formation can be
specifically stimulated by visible light or visible laser irradiation and can be
augmented further by photodynamic coupling with photosensitizers, particularly
with mitochondria-targeted photosensitizers. “Severe” oxidative insult often
results in massive and homogeneous augmentation of mROS formation which causes
cessation of mitochondrial movement, pathological fission and irreversible
swelling of mitochondria and eventually apoptosis or necrosis of cells.
Mitochondria-targeted antioxidants and protectors such as MitoQ, melatonin and
nanoparticle C(60) effectively prevent “severe” mROS generation. Intriguingly,
“minor” oxidative insults enhance heterogeneity of mROS and mitochondrial
dynamics. “Minor” mROS formation-induced fission and fusion of mitochondria
relocates mitochondrial network to form a mitochondria free gap, i.e.,
“firewall”, which may play a crucial role in mROS-mediated protective
“preconditioning” by preventing propagation of mROS during oxidative insults.
These mROS-targeted strategies for either enhancement or prevention of
mitochondrial oxidative stress in astrocytes may provide new insights for future
development of therapeutic interventions in the treatment of cancer such as
astrocytomas and gliomas and astrocyte-associated neurodegeneration,
mitochondrial diseases and aging.
Endovascular therapy for critical limb ischemia. Arain SA, White CJ. Vasc Med. 2008 Aug;13(3):267-79.
Chronic critical limb ischemia (CLI) occurs when arterial perfusion is reduced
below a threshold level that results in rest pain and/or tissue breakdown in the
lower extremities. Importantly, it is associated with high cardiovascular
morbidity and mortality. Without prompt revascularization, CLI may result in loss
of a limb (i.e. amputation) and/or life. The goal of endovascular therapy is the
re-establishment of pulsatile, straight-line flow to the distal extremity.
Percutaneous transluminal angioplasty (PTA) has been shown to be effective and
safe in the setting of CLI, with limb salvage rates that compare favorably with
surgical procedures. Stents are indicated for failed PTA, while adjunctive
therapies such as lasers, thermal angioplasty and atherectomy devices lack data
demonstrating improved efficacy compared with conventional lower extremity
interventions. In addition to successful revascularization, the institution of
lifestyle changes, atherosclerotic risk factor modification, and pharmacologic
therapies are indicated to reduce cardiovascular morbidity and mortality.
Light curing of resin-based composites in the LED era. Krämer N, Lohbauer U, García-Godoy F, Frankenberger R. Am J Dent. 2008 Jun;21(3):135-42.
This review thoroughly accumulated information regarding new technologies for
state-of-the-art light curing of resin composite materials. Visible light cured
resin-based composites allow the dentist to navigate the initiation of the
polymerization step for each layer being applied. Curing technology was regularly
subjected to changes during the last decades, but meanwhile the LED era is fully
established. Today, four main polymerization types are available, i.e. halogen
bulbs, plasma are lamps, argon ion lasers, and light emitting diodes.
Additionally, different curing protocols should help to improve
photopolymerization in terms of less stress being generated. Conclusions were:
(1) with high-power LED units of the latest generation, curing time of 2 mm thick
increments of resin composite can be reduced to 20 seconds to obtain durable
results; (2) curing depth is fundamentally dependent on the distance of the resin
composite to the light source, but only decisive when exceeding 6 mm; (3)
polymerization kinetics can be modified for better marginal adaptation by
softstart polymerization; however, in the majority of cavities this may not be
the case; (4) adhesives should be light-cured separately for at least 10 seconds
when resin composite is applied directly; (5) photocuring through indirect
restorations such as ceramics is still a problem, therefore, both dual-cured
adhesives and dual-cured composites and resin coating in any way are recommended;
and (6) heat generation with high-power photopolymerization units should not be
underestimated as a biological problem for both gingival and pulpal tissues.
Skin directed therapy for mycosis fungoides: a review. Berthelot C, Rivera A, Duvic M. J Drugs Dermatol. 2008 Jul;7(7):655-66.
Mycosis fungoides (MF) is a rare neoplasm of epidermotropic CD4+ lymphocytes and
represents a majority of all cutaneous T cell lymphomas. Early stage MF is
limited to cutaneous patches and plaques that can be treated with topical
modalities with high response rates. More aggressive systemic treatment of early
disease does not alter survival or cure the disease and could accelerate
progression by causing immunosuppression. Topical corticosteroids,
mechlorethamine, and carmustine have been the mainstays of early treatment of MF
for more than 30 years. More recently, topical formulations of retinoids, novel
rexinoids, methotrexate, immunomodulators, and photodynamic compounds have been
investigated for their potential roles in treating early ME The future of topical
treatments for MF is promising both as primary and adjunctive therapy.
A new modality for minimally invasive CO2 laser surgery: flexible hollow-core photonic bandgap fibers. Shurgalin M, Anastassiou C. Biomed Instrum Technol. 2008 Jul-Aug;42(4):318-25.
Carbon dioxide (CO2) lasers have become one of the most common surgical lasers
due to excellent tissue interaction properties that offer precise control of
cutting and ablation depth, minimal thermal damage to surrounding tissue, and
good hemostasis. However, realization of the benefits offered by using surgical
CO2 lasers in many endoscopic, minimally invasive surgical procedures has been
inhibited by the absence of reliable, flexible fiber laser beam delivery systems.
Recently, novel hollow-core photonic bandgap optical fibers for CO2 lasers were
developed that offer high flexibility and mechanical robustness with good optical
performance under tight bends. These fibers can be used through rigid and
flexible endoscopes and various handpieces and will allow surgeons to perform
delicate and precise laser surgery procedures in a minimally invasive manner.
This paper describes the basic design of laser beam delivery system, different
surgical fiber designs and their characteristics, and usage with existing
surgical CO2 laser models. A few examples of successful CO2 laser surgeries
performed with these fibers are presented.
[Femtosecond laser application in keratoplasty--current view] [Article in Polish] Wylegała E, Milka M, Tarnawska D, Dobrowolski D. Klin Oczna. 2008;110(4-6):207-10.
Main purpose of this article is to present an actual review of application
femtosecound laser in keratoplasty. Femtosecound laser keratome is a new option
in corneal surgery that provides depth and diameter accuracy even at increased
depth settings. It seems to be an ideal instrument to carry out stromal tissue
cuttings in penetrating and lamellar keratoplasty as well as in refractive
surgery. In this paper we also paid attention on adventages and disadventages of
use FL, as well we compare this new technology with mechanical handheld
Surgical atrial fibrillation ablation: a review of contemporary techniques and energy sources. Aktas MK, Daubert JP, Hall B. Cardiol J. 2008;15(1):87-94.
Prevention and management of hypertrophic scars and keloids after burns in children. Berman B, Viera MH, Amini S, Huo R, Jones IS. J Craniofac Surg. 2008 Jul;19(4):989-1006.
Hypertrophic scars and keloids are challenging to manage, particularly as
sequelae of burns in children in whom the psychologic burden and skin
characteristics differ substantially from adults. Prevention of hypertrophic
scars and keloids after burns is currently the best strategy in their management
to avoid permanent functional and aesthetical alterations. Several actions can be
taken to prevent their occurrence, including parental and children education
regarding handling sources of fire and flammable materials, among others.
Combination of therapies is the mainstay of current burn scar management,
including surgical reconstruction, pressure therapy, silicon gels and sheets, and
temporary garments. Other adjuvant therapies such as topical imiquimod,
tacrolimus, and retinoids, as well as intralesional corticosteroids,
5-fluorouracil, interferons, and bleomycin, have been used with relative success.
Cryosurgery and lasers have also been reported as alternatives. Newer treatments
aimed at molecular targets such as cytokines, growth factors, and gene therapy,
currently in developing stages, are considered the future of the treatment of
postburn hypertrophic scars and keloids in children.
Non-invasive study of nerve fibres using laser interference microscopy. Brazhe AR, Brazhe NA, Rodionova NN, Yusipovich AI, Ignatyev PS, Maksimov GV, Mosekilde E, Sosnovtseva OV. Philos Transact A Math Phys Eng Sci. 2008 Oct 13;366(1880):3463-81.
This paper presents the results of a laser interference microscopy study of the
morphology and dynamical properties of myelinated nerve fibres. We describe the
principles of operation of the phase-modulated laser interference microscope and
show how this novel technique allows us to obtain information non-invasively
about the internal structure of different regions of a nerve fibre. We also
analyse the temporal variations in the internal optical properties in order to
detect the rhythmic activity in the nerve fibre at different time scales and to
shed light on the underlying biological processes. We observe pronounced
frequencies in the dynamics of the optical properties and suggest that the
oscillatory modes have similar origin in different regions, but different
strengths and mutual modulation properties.
Why wavelength and delivery systems are the most important factors in using a dental hard-tissue laser: a literature review. Bornstein ES. Compend Contin Educ Dent. 2003 Nov;24(11):837-8, 841, 843 passim; quiz 848.
Various lasers have been investigated in the dental clinic as an alternative to
the dental drill for the treatment of dental hard tissues. Among the lasers, the
erbium-based solid-state infrared lasers, operating at approximately 3 microm,
have demonstrated they are effective in dental applications because of their high
affinity for water in the hydroxyapatite of the tooth structure. Water is the
dominant chromophore that absorbs the laser energy during hard-tissue treatment;
this leads to well-established, mechanical, thermally driven, and explosive
ablation, which is the basis for the erbium laser-tissue interaction. A review of
the literature presents a number of studies in which the superior qualities of
the Er:YAG laser, in particular, are demonstrated. Er:YAG irradiation results in
the least amount of temperature increase at the laser-tooth interface. The Er:YAG
laser generates photons with the strongest absorption by water in the enamel and
dentin and, when combined with a water cooling spray, produces extremely minor
zones of carbonization, debris, and necrosis after irradiation. Furthermore, the
Er:YAG laser wavelength can be easily delivered with a hollow waveguide delivery
system and contact sapphire tip, resulting in a more precise cavity preparation
than other delivery systems. The Er:YAG laser system offers the optimal
wavelength and the ability to be transmitted in the most efficient manner for
successful dental hard-tissue ablation.
Two-photon excitation fluorescence bioassays. Hänninen P, Soukka J, Soini JT. Ann N Y Acad Sci. 2008;1130:320-6.
Application of two-photon excitation of fluorescence in microscopy is one of the
major discoveries of the “renaissance” of light microscopy that started in the
1980s. The technique derives its advantages from the biologically “smooth”
wavelength of the excitation light and the confinement of the excitation.
Difficult, and seemingly nontransparent, samples may be imaged with the technique
with good resolution. Although the bioresearch has been concentrating mostly on
the positive properties of the technique for imaging, the same properties may be
applied successfully to nonimaging bioassays. This article focuses on the
development path of two-photon excitation-based assay system.
Characterization of water-soluble luminescent quantum dots by fluorescence correlation spectroscopy. Dong C, Huang X, Ren J. Ann N Y Acad Sci. 2008;1130:253-61.
Quantum dots (QDs) are nanoscale inorganic particles generally composed of II-VI
and III-V elements. Recently, QDs have received great interest in biological
applications because of their unique and fascinating optical properties. In this
short review, we introduce the synthesis of luminescent QDs in the aqueous phase
and characterize certain fundamental parameters of luminescent QDs synthesized in
the aqueous phase by fluorescence correlation spectroscopy (FCS), which include,
for example, their dynamic diameters and surface charges. Meanwhile, combining
with some ensemble spectroscopy techniques, we applied FCS to investigate the
quenching process and mechanism of heavy metal ions (e.g., Ag(+)) on CdTe QDs, as
well as the aggregation and subsequent photoactivation process of
3-mercaptopropionic acid-capping CdTe QDs induced by laser irradiation. Our
preliminary results demonstrate that FCS is a sensitive and efficient tool to
characterize fluorescent nanoparticles, such as QDs, at the single-molecule
Time-gated luminescence microscopy. Connally RE, Piper JA. Ann N Y Acad Sci. 2008;1130:106-16.
Autofluorescent algal samples were spiked with europium beads for analysis on a
novel all-solid-state, time-gated luminescence (TGL) microscope. Pulsed UV
excitation (365 nm) was provided by a high-power UV-LED source fitted to an
Olympus BX51 microscope. An “Impactron” electron multiplying
charge-coupled-device (CCD) camera acquired images in delayed luminescence mode.
Second, we evaluated sensitivity of the instrument by acquiring images of
immunofluorescently labeled Giardia cysts with a single-exposure period of 3 ms.
The camera was triggered 3 micros after the LED had extinguished to yield a
14-fold increase in signal-to-noise ratio within a single 33 ms capture cycle.
This novel instrument could be switched instantly from prompt epifluorescence
mode to TGL mode for suppression of short-lived fluorescence.
Frequency domain fluorometry with pulsed light-emitting diodes. Herman P, Vecer J. Ann N Y Acad Sci. 2008;1130:56-61.
We present a simple way to extend the time resolution of a standard frequency
domain (FD) fluorometer by use of pulsed light-emitting diodes (LEDs) as an
excitation source. High temporal resolution of the multifrequency FD method
requires the excitation light to be modulated up to the highest possible
frequencies with high modulation depth. We used harmonic content of
subnanosecond-pulsed LEDs for generation of modulated excitation light. By a
replacement of the light source, the upper frequency limit increased to 500-600
MHz, which is almost triple the frequency limit of the standard FD fluorometer
equipped with an ordinary photomultiplier tube and an electro-optical modulator.
Besides the increased time resolution, this approach allowed for elimination of a
light modulator with an associated synthesizer and radio frequency power
amplifier that are normally required for FD measurements with continuous wave
light sources. Performance of the instrument with pulsed LED excitation is
demonstrated on several examples of ultraviolet-excited fluorescence decays. We
show that pulsed LEDs can serve as an inexpensive alternative to pulsed laser
sources for FD fluorescence spectroscopy.
Treatment options for benign prostatic hyperplasia in older men. Miano R, De Nunzio C, Asimakopoulos AD, Germani S, Tubaro A. Med Sci Monit. 2008 Jul;14(7):RA94-102.
BACKGROUND: Benign prostatic enlargement (BPE) is one of the most common diseases
in ageing men; it is associated with bothersome lower urinary tract symptoms that
affect the individual’s quality of life. This review focuses on the different
available options for treating benign prostatic hyperplasia (BPH) in older men
and on how to choose the right treatment. MATERIAL/METHODS: A literature search
was done to review relevant papers. Relatively recent papers, as well as those in
a series or papers from expert centers, are included in the reference list.
RESULTS: Treatment options for BPE in older men include medical therapy,
transurethral resection of the prostate (TURP), minimally invasive treatments
(ie, transurethral microwave thermotherapy, transurethral needle ablation, and
laser surgery) and prostatic stenting. Age, individual anesthesiologic risk,
grade of obstruction, prostate volume, serum prostate specific antigen (PSA)
value, treatment-related complication rate, presence of an indwelling catheter,
and neurologic disorders are factors that should be taken into consideration in
choosing an appropriate treatment. CONCLUSIONS: Given the wealth of treatment
options available, physicians must take care to choose the right treatment for
each patient, depending on the patient’s needs and medical history.
Laser-based gene transfection and gene therapy. Yao CP, Zhang ZX, Rahmanzadeh R, Huettmann G. IEEE Trans Nanobioscience. 2008 Jun;7(2):111-9.
The plasma membrane of mammalian cells can be transiently permeablized by optical
means and exogenous materials or genes can be introduced into the cytoplasm of
living cells. Until now, few mechanisms were exploited for the manipulation:
laser is directly and tightly focused on the cells for optoinjection,
laser-induced stress waves, photochemical internalization, and irradiation of
selective cell targeting with light-absorbing particles. During the past few
years, extensive progress and numerous breakthroughs have been made in this area
of research. This review covers four different laser-assisted transfection
techniques and their advantages and disadvantages. Universality towards various
cell lines is possibly the main advantage of laser-assisted optoporation in
comparison with presently existing methods of cell transfection.
Refractive surgery for children: excimer laser, phakic intraocular lens, and clear lens extraction. Tychsen L. Curr Opin Ophthalmol. 2008 Jul;19(4):342-8.
Department of Ophthalmology, St Louis Children’s Hospital at Washington
University Medical Center, St Louis, Missouri 63110, USA.
PURPOSE OF REVIEW: The article summarizes current recommendations for refractive
surgery and outcomes in ametropic children who are spectacle noncompliant and
unsuitable for contact lens wear. RECENT FINDINGS: The majority of those treated
have anisometropic amblyopia. The most common method employed is advanced surface
ablation using the excimer laser, such as photorefractive keratectomy or
laser-assisted subepithelial keratomileusis. Surface ablation is safe in
children; the drawback is the high rate of refractive regression, which is most
pronounced in children with myopia beyond 10.0 D and hyperopia beyond 4.5 D.
Those with more extreme ametropia–beyond the effective range for surface
ablation–need phakic intraocular lens implantation or clear lens extraction,
with or without implantation of a posterior chamber intraocular lens (refractive
lens exchange). Children with neurobehavioral disorders and high bilateral
ametropia may be functionally blind without the surgery. The prevalence of
complications with each of these techniques–over follow-up generally less than 5
years–has been low. Longer follow-up will be more revealing. SUMMARY: The
majority of children with ametropia–unilateral or bilateral–do well with
glasses or contact lenses, but a minority do not. Pediatric refractive surgery
meets an important need for this minority.
Postrefractive surgery dry eye. Quinto GG, Camacho W, Behrens A. Curr Opin Ophthalmol. 2008 Jul;19(4):335-41.
PURPOSE OF REVIEW: To report the recently published literature on ocular surface
changes after refractive surgery, as well as the outcomes of treatment modalities
on postrefractive surgery dry eye. RECENT FINDINGS: Cyclosporine, the first US
Food and Drug Administration approved agent to treat the underlying pathological
mechanism of chronic dry eye, has demonstrated promising results in dry eye
patients. Further, there may be an additive effect of topical cyclosporine and
punctal occlusion. Femtosecond lasers for corneal flaps in laser in-situ
keratomileusis seem to induce fewer signs and symptoms of dry eye and may be
attributed to the creation of thinner flaps. SUMMARY: Dry eye is one of the most
common complications after photorefractive keratectomy and laser in-situ
keratomileusis. Keratorefractive surgery is known to cause damage to the corneal
sensory nerves. Several studies have demonstrated a decrease in corneal
sensation, tear secretion, and tear film stability several months after
keratorefractive surgery. For patients with preoperative dry eye, the ocular
surface must be treated accordingly prior to surgery.
Laser refractive surgery in the United States Navy. Stanley PF, Tanzer DJ, Schallhorn SC. Curr Opin Ophthalmol. 2008 Jul;19(4):321-4.
PURPOSE OF REVIEW: The aim of this article is to highlight the numerous
contributions the US Navy has made to the field of laser refractive surgery. It
summarizes and draws together published papers, national meeting presentations,
and unpublished data of clinical and laboratory studies involving the excimer
laser and the laser-assisted in-situ keratomileusis (LASIK) flap. RECENT
FINDINGS: Photorefractive keratectomy (PRK) is the most widely performed
refractive procedure in the US Navy, but this trend is slowly changing as
femtosecond laser-assisted LASIK becomes more widely performed. Based on the
results of recent studies, PRK is approved for designated Naval aviators and
flight officers; post-PRK students are now allowed into flight training.
Wavefront-guided PRK and LASIK are more predictable and provided better results
than conventional PRK and LASIK. Femtosecond laser-assisted LASIK is now a
waiverable procedure for US military personnel and US Astronauts (excluding Naval
aviators, as of this writing). SUMMARY: Since its personnel must meet strict
visual requirements to accomplish their mission in a variety of environments, the
US Navy places particular emphasis on safety and quality of vision after laser
refractive surgery. The US Navy has been evaluating the safety and efficacy of
laser refractive surgery since 1993 and will continue to do so.
Optical Phase locking techniques: an overview and a novel method based on single side sub-carrier modulation. Ferrero V, Camatel S. Opt Express. 2008 Jan 21;16(2):818-28.
A short overview on Optical Phase locking techniques and a detailed description
of the Phase Locking technique based on Sub-Carriers modulation is presented.
Furthermore, a novel Single Side Sub-Carrier-based Optical Phase Locked Loop
(SS-SC-OPLL), with off the shelf optical components, is also presented and
experimentally demonstrated. Our new method, based on continuous wave
semiconductor lasers and optical single side sub-carrier modulation using QPSK
LiNbO(3) modulator, allows a practical implementation with better performance
with respect to the previously proposed OPLL circuits, and permits an easy use in
real time WDM signal coherent demodulation.
Optical methods for measurements of skin penetration. Gotter B, Faubel W, Neubert RH. Skin Pharmacol Physiol. 2008;21(3):156-65. Epub 2008 Jun 3.
Fourier transform infrared photoacoustic (PAS), photothermal deflection (PDS) and
Raman spectroscopy belong to the modern innovative noninvasive analytical tools
that are beginning to be recognized as highly potential techniques for the
noninvasive study of biological tissues and human skin under in vivo conditions.
They can be applied to obtain information regarding the molecular composition of
the skin down to several hundred micrometers below the skin surface. All three
methods allow depth-resolved investigations. While PAS and PDS use a frequency
modulation of the excitation beam to reach deeper regions in the sample, the
principle of confocal Raman microspectroscopy (CRM) is a movement of the specimen
in the focal plane. In consideration of depth measurements PAS and PDS complete
the applicable spectrum of CRM, since Raman microscopy requires particular
transparent materials. (c) 2008 S. Karger AG, Basel.
Bioimaging of cells and tissues using accelerator-based sources. Petibois C, Cestelli Guidi M. Anal Bioanal Chem. 2008 Jul;391(5):1599-608. Epub 2008 Jun 3.
A variety of techniques exist that provide chemical information in the form of a
spatially resolved image: electron microprobe analysis, nuclear microprobe
analysis, synchrotron radiation microprobe analysis, secondary ion mass
spectrometry, and confocal fluorescence microscopy. Linear (LINAC) and circular
(synchrotrons) particle accelerators have been constructed worldwide to provide
to the scientific community unprecedented analytical performances. Now, these
facilities match at least one of the three analytical features required for the
biological field: (1) a sufficient spatial resolution for single cell (< 1 mum)
or tissue (<1 mm) analyses, (2) a temporal resolution to follow molecular
dynamics, and (3) a sensitivity in the micromolar to nanomolar range, thus
allowing true investigations on biological dynamics. Third-generation
synchrotrons now offer the opportunity of bioanalytical measurements at nanometer
resolutions with incredible sensitivity. Linear accelerators are more specialized
in their physical features but may exceed synchrotron performances. All these
techniques have become irreplaceable tools for developing knowledge in biology.
This review highlights the pros and cons of the most popular techniques that have
been implemented on accelerator-based sources to address analytical issues on
Physics and applications of atmospheric nonlinear optics and filamentation. Kasparian J, Wolf JP. Opt Express. 2008 Jan 7;16(1):466-93.
We review the properties and applications of ultrashort laser pulses in the
atmosphere, with a particular focus on filamentation. Filamentation is a
non-linear propagation regime specific of ultrashort and ultraintense laser
pulses in the atmosphere. Typical applications include remote sensing of
atmospheric gases and aerosols, lightning control, laser-induced spectroscopy,
coherent anti-stokes Raman scattering, and the generation of sub-THz radiation.
Vascular birthmarks. Willenberg T, Baumgartner I. Vasa. 2008 Feb;37(1):5-17.
Vascular birthmarks can be classified into hemangioma and vascular malformations.
Hemangioma are frequent tumours of early infancy demonstrating endothelial
hyperplasia, a history of rapid neonatal growth and slow involution during later
childhood. Treatment of hemangioma is dependent of stage and type of the lesion.
Given the current availability of drugs, lasers, and other techniques to treat
hemangioma safely, philosophy of "benign neglect" should not be considered
anymore. Vascular malformations show a normal endothelial turnover, being present
at birth and growing commensurately with the child. Exact diagnosis by employing
modern diagnostic means,which are able to differentiate low-flow from high flow
lesions is important for further therapeutic management. Beside conservative
treatment strategies, use of laser, sclerotherapy, interventional embolization
and surgical treatment are possible management options. Patients should receive
multidisciplinary care in qualified vascular centres.
A systematic review with procedural assessments and meta-analysis of low level laser therapy in lateral elbow tendinopathy (tennis elbow). Bjordal JM, Lopes-Martins RA, Joensen J, Couppe C, Ljunggren AE, Stergioulas A, Johnson MI. BMC Musculoskelet Disord. 2008 May 29;9:75.
BACKGROUND: Recent reviews have indicated that low level level laser therapy
(LLLT) is ineffective in lateral elbow tendinopathy (LET) without assessing
validity of treatment procedures and doses or the influence of prior steroid
injections. METHODS: Systematic review with meta-analysis, with primary outcome
measures of pain relief and/or global improvement and subgroup analyses of
methodological quality, wavelengths and treatment procedures. RESULTS: 18
randomised placebo-controlled trials (RCTs) were identified with 13 RCTs (730
patients) meeting the criteria for meta-analysis. 12 RCTs satisfied half or more
of the methodological criteria. Publication bias was detected by Egger's
graphical test, which showed a negative direction of bias. Ten of the trials
included patients with poor prognosis caused by failed steroid injections or
other treatment failures, or long symptom duration or severe baseline pain. The
weighted mean difference (WMD) for pain relief was 10.2 mm [95% CI: 3.0 to 17.5]
and the RR for global improvement was 1.36 [1.16 to 1.60]. Trials which targeted
acupuncture points reported negative results, as did trials with wavelengths 820,
830 and 1064 nm. In a subgroup of five trials with 904 nm lasers and one trial
with 632 nm wavelength where the lateral elbow tendon insertions were directly
irradiated, WMD for pain relief was 17.2 mm [95% CI: 8.5 to 25.9] and 14.0 mm
[95% CI: 7.4 to 20.6] respectively, while RR for global pain improvement was only
reported for 904 nm at 1.53 [95% CI: 1.28 to 1.83]. LLLT doses in this subgroup
ranged between 0.5 and 7.2 Joules. Secondary outcome measures of painfree grip
strength, pain pressure threshold, sick leave and follow-up data from 3 to 8
weeks after the end of treatment, showed consistently significant results in
favour of the same LLLT subgroup (p < 0.02). No serious side-effects were
reported. CONCLUSION: LLLT administered with optimal doses of 904 nm and possibly
632 nm wavelengths directly to the lateral elbow tendon insertions, seem to offer
short-term pain relief and less disability in LET, both alone and in conjunction
with an exercise regimen. This finding contradicts the conclusions of previous
reviews which failed to assess treatment procedures, wavelengths and optimal
LASIK-associated dry eye and neurotrophic epitheliopathy: pathophysiology and strategies for prevention and treatment. Ambrósio R Jr, Tervo T, Wilson SE. J Refract Surg. 2008 Apr;24(4):396-407.
PURPOSE: To review the pathophysiology of LASIK-associated dry eye conditions and
provide insights into prophylaxis to decrease the incidence of dry eye after
LASIK and to treat the condition when it occurs. METHODS: A review of the
literature was performed on LASIK-associated dry eye and the experience of the
authors was summarized. RESULTS: LASIK has a neurotrophic effect on the cornea,
along with other changes in corneal shape, that affect tear dynamics causing
ocular surface desiccation. Dry eye is one of the most common complications of
LASIK surgery. Symptoms of dryness may occur in more than 50% of patients, with
other complications such as fluctuating vision, decreased best
spectacle-corrected visiual acuity, and severe discomfort occurring in
approximately 10% of patients. Preoperative dry eye condition is a major risk
factor for more severe dry eye after surgery and should be identified prior to
surgery. Optimization with artificial tears, nutrition supplementation, punctal
occlusion, and topical cyclosporine A in patients with symptoms or signs of dry
eye prior to LASIK decreases the incidence of more bothersome symptoms following
surgery. Patients with LASIK-induced neurotrophic epitheliopathy often respond to
topical cyclosporine A treatment, which treats the underlying inflammation and
may benefit nerve regeneration. CONCLUSIONS: LASIK-induced dry eye and
neurotrophic epitheliopathy are common complications of LASIK surgery.
Optimization of the ocular surface prior to surgery decreases the incidence and
severity of postoperative symptoms of the condition.
Fractional photothermolysis: a review and update. Jih MH, Kimyai-Asadi A. Semin Cutan Med Surg. 2008 Mar;27(1):63-71.
Fractional resurfacing is a new laser treatment modality that creates numerous
microscopic thermal injury zones of controlled width, depth, and density that are
surrounded by a reservoir of spared epidermal and dermal tissue, allowing for
rapid repair of laser-induced thermal injury. This unique modality, if
implemented with proper laser-delivery systems, enables high-energy treatments
while minimizing risks. In this article, we review the various fractional laser
devices, including the new fractional ablative devices, as well as the results of
studies on the clinical efficacy of fractional photothermolysis. This technology
offers patients significant clinical improvement in photodamage, melasma, and
scarring with modest treatment-related downtime and minimal risk of
The hazards of surgical smoke. Ulmer BC. AORN J. 2008 Apr;87(4):721-34; quiz 735-8.
Surgical smoke is a part of the environment during operative and invasive
procedures. As lasers and electrosurgery have become commonplace, perioperative
practitioners are at increased risk for health concerns associated with exposure
to surgical smoke. Since the mid 1970s, the body of evidence documenting the
hazardous components of surgical smoke has continued to grow. Despite the
evidence and recommendations of a variety of organizations, there are no uniform
requirements mandating surgical smoke evacuation. This article reviews current
research to identify the potential health hazards as well as the current
recommendations related to the filtration and evacuation of surgical smoke. (c)
AORN, Inc, 2008.
Lasers in endodontics: an online study guide. JOE Editorial Board. J Endod. 2008 May;34(5 Suppl):e33-6.
The Editorial Board of the Journal of Endodontics has developed a
literature-based study guide of topical areas related to endodontics. This study
guide is intended to give the reader a focused review of the essential endodontic
literature and does not cite all possible articles related to each topic.
Although citing all articles would be comprehensive, it would defeat the idea of
a study guide. This section will focus on the use of lasers in endodontics.
[Laser hair removal] [Article in French] Michaud T, Tack B. Ann Dermatol Venereol. 2008 Feb;135 Suppl 3:S200-4.
The theory behind laser hair removal and pulsed flashlamps is briefly reviewed,
as are the devices currently available for this indication. Today, the treatment
procedure has been firmly established so that clear and precise information can
be provided to patient on the results obtained with these techniques, both for
medical and esthetic indications. The potential complications are discussed with
respect to the treatment procedures and a thorough understanding of the
Methods for nitric oxide detection during plant-pathogen interactions. Vandelle E, Delledonne M. Methods Enzymol. 2008;437:575-94.
Nitric oxide (NO) is involved in the transduction of numerous signals in living
organisms, and its biological effects are often influenced by its concentration.
Therefore, the ability to reliably detect and quantify NO is crucial to
understanding its role in cellular processes. Many techniques are available to
detect and quantify NO, but depending on the material and the aim of the
analysis, specific adaptations are often required because its high chemical
reactivity leads to the formation of numerous reactive nitrogen species that make
the accurate determination of NO levels difficult. Moreover, the pathogen-induced
hypersensitive response leads to high rates of reactive oxygen species production
that react with NO and lead to the formation of its oxidized derivates. The aim
of this chapter is to provide an overview of the methods that have so far been
employed to detect and measure NO in plants during the hypersensitive disease
Efficacy of low-level laser therapy for chronic cutaneous ulceration in humans: a review and discussion. Sobanko JF, Alster TS. Dermatol Surg. 2008 Aug;34(8):991-1000. Epub 2008 Apr 22.
Chronic wounds, particularly venous ulcerations, are notoriously difficult to
heal. Because current therapies are variable in their ability to induce complete
healing, there remains a need to develop adjunctive treatments that can improve
or accelerate the healing process. The use of low-energy lasers to stimulate
wound healing has been pursued over many decades in studies of varying quality.
This form of treatment has had high appeal due to its novelty, relative ease, and
low morbidity profile. The authors reviewed the available published literature on
low-level laser technology in an attempt to provide cumulative insight on the
effect of this treatment for wound healing.
Safety and efficacy of PRK and LASIK in pediatric patients. Qian Y, Pineda R. Int Ophthalmol Clin. 2008 Spring;48(2):193-208.
Current techniques for single-cell lysis. Brown RB, Audet J. J R Soc Interface. 2008 Oct 6;5 Suppl 2:S131-8.
Owing to the small quantities of analytes and small volumes involved in
single-cell analysis techniques, manipulation strategies must be chosen
carefully. The lysis of single cells for downstream chemical analysis in
capillaries and lab-on-a-chip devices can be achieved by optical, acoustic,
mechanical, electrical or chemical means, each having their respective strengths
and weaknesses. Selection of the most appropriate lysis method will depend on the
particulars of the downstream cell lysate processing. Ultrafast lysis techniques
such as the use of highly focused laser pulses or pulses of high voltage are
suitable for applications requiring high temporal resolution. Other factors, such
as whether the cells are adherent or in suspension and whether the proteins to be
collected are desired to be native or denatured, will determine the suitability
of detergent-based lysis methods. Therefore, careful selection of the proper
lysis technique is essential for gathering accurate data from single cells.
Update on photoselective vaporization of the prostate. Sountoulides P, de la Rosette JJ. Curr Urol Rep. 2008 Mar;9(2):106-12.
Photoselective vaporization of the prostate (PVP) with a potassium titanyl
phosphate (KTP) laser may be the most promising new technology applied to the
treatment of benign prostatic hyperplasia (BPH). The specific laser light
characteristics and the ideal interactions between KTP lasers and prostatic
tissue result in an even and efficient vaporization of the prostate and the
formation of a clearly deobstructed prostate cavity. PVP can be a day-care
procedure, with few hours of catheterization and minimal postoperative
discomfort, offering outcomes at least equivalent to the reference standard
transurethral resection of the prostate. Although larger studies are necessary to
further define where PVP stands in the management of BPH, this review focuses on
contemporary treatment techniques and their limitations, and comments on the
outcomes of its current use.
Endoscopic and transscleral cyclophotocoagulation for the treatment of refractory glaucoma. Lin SC. J Glaucoma. 2008 Apr-May;17(3):238-47.
PURPOSE: Cyclophotocoagulation (CPC) is traditionally used in cases of glaucoma
that are refractory to medical and surgical therapy. The goal of this review is
to provide an update on the methods, efficacy, complications, indications, and
histopathology of transscleral and endoscopic CPC. METHODS: A literature review
was conducted for transscleral and endoscopic CPC. Relevant studies were included
for evaluation of the procedures. RESULTS: For transscleral CPC (TCP), there is a
wide range of success rates reported in the literature, depending on energy
settings, follow-up period, and definitions of success. Repeat TCP is often
required. Serious complications have included significant vision loss, hypotony,
and phthisis. TCP has mostly been performed in very severe forms of glaucoma, in
eyes with limited visual potential, or after filtration surgery has failed,
although more recently TCP has been used as a primary surgery in eyes with good
visual potential. There are more limited published results on endoscopic CPC
(ECP), which have demonstrated overall good success. Complication rates are
relatively low with ECP, however, large studies with long-term follow-up are
lacking. ECP has also been used in difficult, refractory cases, but often used
earlier when combined with cataract surgery. CONCLUSIONS: Both TCP and ECP are
effective surgeries with potential for serious complications. Recent studies
suggest they may be used increasingly as the primary surgery for various stages
Photodynamic therapy in dermatology--an update 2008. [Article in English, German] Klein A, Babilas P, Karrer S, Landthaler M, Szeimies RM. J Dtsch Dermatol Ges. 2008 Oct;6(10):839-45, 839-46. Epub 2008 Apr 9.
SUMMARY: Photodynamic therapy (PDT) is used for the prevention and treatment of
non-melanoma skin cancer. Until recently, clinically approved indications have
been restricted to actinic keratoses, nodular and superficial basal cell
carcinoma, and--since 2006--Bowen disease. However, the range of indications has
been expanding continuously. PDT is also used for the treatment of non-malignant
conditions such as acne vulgaris and leishmaniasis, as well as for treating
premature skin aging due to sun exposure. Here, PDT is used for the stimulation
of immunomodulatory effects in contrast to the induction of necrosis and
apoptosis as produced in the treatment of skin tumors. The porphyrin precursor
5-aminolevulinic acid (ALA) or its methyl ester (MAL, so far the only approved
formulation in Europe) is applied topically as photosensitizer to exclude
systemic reactions. Possible light sources include lasers as well as incoherent
light sources; irradiation with incoherent light sources is cheaper and more
appropriate for large treatment areas. The main advantages of PDT in comparison
to other treatment modalities are its excellent cosmetic results and its high
remission rates despite low invasiveness.This article provides up-to-date
information about PDT with focus on recently published studies.
Restoration of accommodation: surgical options for correction of presbyopia. Glasser A. Clin Exp Optom. 2008 May;91(3):279-95.
Accommodation is a dioptric change in the power of the eye to see clearly at
near. Ciliary muscle contraction causes a release in zonular tension at the lens
equator, which permits the elastic capsule to mould the young lens into an
accommodated form. Presbyopia, the gradual age-related loss of accommodation,
occurs primarily through a gradual age-related stiffening of the lens. While
there are many possible options for relieving the symptoms of presbyopia, only
relatively recently has consideration been given to surgical restoration of
accommodation to the presbyopic eye. To understand how this might be achieved, it
is necessary to understand the accommodative anatomy, the mechanism of
accommodation and the causes of presbyopia. A variety of different kinds of
surgical procedures has been considered for restoring accommodation to the
presbyopic eye, including surgical expansion of the sclera, using femtosecond
lasers to treat the lens or with so-called accommodative intraocular lenses
(IOLs). Evidence suggests that scleral expansion cannot and does not restore
accommodation. Laser treatments of the lens are in their early infancy.
Development and testing of accommodative IOLs are proliferating. They are
designed to produce a myopic refractive change in the eye in response to ciliary
muscle contraction either through a movement of an optic or through a change in
surface curvature. Three general design principles are being considered. These
are single optic IOLs that rely on a forward shift of the optic, dual optic IOLs
that rely on an increased separation between the two optics, or IOLs that permit
a change in surface curvature to produce an increase in optical power in response
to ciliary muscle contraction. Several of these different IOLs are available and
being used clinically, while many are still in research and development.
Epidermal nevus syndromes. Sugarman JL. Semin Cutan Med Surg. 2007 Dec;26(4):221-30.
The term "epidermal nevus syndrome" (ENS) has been used to describe the
association of epidermal hamartomas and extra-cutaneous abnormalities. Epidermal
nevi follow the lines of Blaschko. The majority of the extra-cutaneous
manifestations involve the brain, eye, and skeletal systems. Several subsets with
characteristic features have been delineated including the nevus sebaceous
syndrome, Proteus syndrome, CHILD syndrome, Becker nevus syndrome, nevus
comedonicus syndrome, and phakomatosis pigmentokeratotica. Epidermal nevi have
been associated with benign and malignant neoplasms. Advances in molecular
biology have revealed that the manifestations of ENS are due to genomic
mosaicism. It is likely that the varied clinical manifestations of ENS are due in
great part to the functional effects of specific genetic defects. Optimal
management of the patient with ENS involves an interdisciplinary approach.
Amelioration of the cutaneous features of ENS has been difficult but there have
been advances, especially in the use of lasers.
[Recent advances in laser therapy and other technologies] [Article in Spanish] Boixeda P, Calvo M, Bagazgoitia L. Actas Dermosifiliogr. 2008 May;99(4):262-8.
Laser technology and other energy sources are rapidly finding a place in
dermatology clinics. In the field of skin rejuvenation by fractional
photothermolysis, although few controlled studies have been undertaken, several
devices have emerged in recent years that appear less effective than laser
ablation techniques but that are safer. The aim of this short article is to
provide an introduction, though not treat in depth, the different emerging
technologies in dermatology. We will focus particularly on lasers and light
sources in improving applications such as the treatment of vascular lesions,
acne, and encapsulated ink tattoos; light-emitting diodes; developments in the
treatment of cellulitis; photodynamic therapy; suction methods; scarring; and
finally the recent and doubtlessly future introduction of home devices for use in
a range of dermatologic applications (depilation, rejuvenation, treatment of
Image guided radiotherapy for prostate cancer. Soete G, Verellen D, Storme G. Bull Cancer. 2008 Mar;95(3):374-80.
The purpose of external beam radiotherapy is to sterilize malignant tumours and
at the same time to avoid complications by radiation injury to the surrounding
healthy tissues. Modern radiation techniques in recent years have allowed to
safely escalate the dose by approximately 10% for the treatment of prostate
cancer, resulting in a disease control that is nowadays comparable to surgery or
permanent seed implant brachytherapy. Two recent technical developments have
dramatically increased the precision of radiation dose delivery: conformal
radiotherapy and image guided radiotherapy (IGRT). Conformal radiotherapy aims to
shape the dose distribution to the shape of the target. At least equally
important as conformality is the accurate spatial delivery of the conformal dose
distribution to the target. Conventional patient positioning by skin drawings and
lasers is an imprecise way to target the prostate within the pelvis. The need for
adequate patient/target setup led in recent years to the development of a variety
of solutions. They bear in common that setup is no longer guided by skin marks
but by some imaging modality. An ideal IGRT system would allow for daily prostate
imaging without possible introduction of errors due to image-acquisition itself,
do so within a reasonable time frame, without the necessity for implanted
radio-opaque markers and preferentially without exposing the patient to
radiation. A solution that combines all these features is inexistent so far.
[New progress in crystallization technology of membrane protein and introduction of pharamaceutical innovation value chain] [Article in Japanese] Inoue T, Adachi H, Murakami S, Takano K, Matsumura H, Mori Y, Fukunishi Y, Nakamura H, Kinoshita T, Nakanishi I, Okuno Y, Minakata S, Shimojo S, Sakata T. Yakugaku Zasshi. 2008 Apr;128(4):497-505.
We have recently established a Pharamaceutical Innovation Value Chain in
collaboration with the SOSHO project (http://www.so-sho.jp) and BioGrid Project
(http://www.biogrid.jp/) to accelerate new drug development. The SOSHO project
provides novel crystallization technology with laser-irradiation and stirring
growth methods, and the BioGrid Project is developing the software necessary for
the in silico screening of promising drugs and the simulation of biological
responses to proteins. In this paper, we report the recent research work on the
crystallization of membrane proteins and the development of a method for in
silico drug discovery.
[Laser information technologies in oncosurgery] [Article in Russian] Chissov VI, Panchenko VIa, Reshetov IV, Evseev AV, Poliakov AP, Filiushin MM. Vestn Ross Akad Med Nauk. 2008;(2):3-6.
The introduction of laser information technologies to medical practice has
improved the results of reconstructive and plastic operations in oncology thanks
to a possibility to plan the surgery beforehand. Sixty-eight patients were
operated on at Gertsen Moscow Research Oncology Institute between 2001 and 2006;
99 stereolithographic models were used to plan different stages of the surgical
intervention. The tasks fulfilled with an individual stereolithographic model,
may be relatively divided into three groups: 1) planning the resection stage; 2)
planning the reconstructive surgery; 3) assessing the necessity to correct the
complex autograft after the reconstructive surgery. The use of laser
stereolithographic modelling in surgical treatment of patients with locally
advanced malignancies made it possible to complete the reconstructive operation
successfully in 98.4% of the patients, and rehabilitate functionally 88.6% of the
Overview of drug delivery and alternative methods to electroporation. Hui SW. Methods Mol Biol. 2008;423:91-107.
This chapter provides an overview of the application of electroporation to areas
other than gene delivery. These areas include the delivery of drugs and vaccines
to tissues and tumors as well as into and through the skin. Achievements and
limitations of electroporation in these areas are presented. Alternative physical
methods for gene and drug delivery besides electroporation are described. The
advantages and drawbacks of electroporation, compared with these methods, are
Hemostatic agents and instruments in laparoscopic renal surgery. Msezane LP, Katz MH, Gofrit ON, Shalhav AL, Zorn KC. J Endourol. 2008 Mar;22(3):403-8.
Control of bleeding is one of the most technically challenging steps in
laparoscopic renal surgery, especially partial nephrectomy. Although there is no
consensus on how best to approach hemostasis, the options continue to expand. The
original method of sutured renorrhaphy is, perhaps, the most effective; however,
great skill is needed to avoid prolonged warm ischemia. Tissue sealants and
adhesives serve as a barrier to leakage and as a hemostat. The four classes are
fibrin sealants, collagen-based adhesives, hydrogel, and glutaraldehyde-based
adhesive. Additionally, oxidized cellulose can be applied to the surface of
kidney or used as a bolster. Fibrin sealants are self-activating and work best on
a dry field. The gelatin matrix agent consists of human-derived thrombin with a
calcium chloride solution and bovine-derived gelatin matrix. The fibrinogen
required to form a clot comes from autologous blood. Another product is
polyethylene glycol-based hydrogel, which acts as a mechanical sealant. The
tissue glue consists of bovine serum albumin and glutaraldehyde, which cross-link
to each other, as well as to other tissue proteins. Excessive use or spillage
around the renal pelvis and ureter may compromise urinary flow. The
methylcellulose products, consisting of oxidized cellulose sheets, usually are
positioned within a sutured bolster and act in part by providing direct pressure.
A number of energy-based technologies also have been utilized. Monopolar cautery
consists of a high-frequency electrical current delivered from a single
electrode. Care must be taken to avoid injurious current transfer to surrounding
structures. With bipolar cautery, hemostasis occurs only between the electrodes.
In the argonbeam coagulator, argon, an inert non-flammable gas that clears from
the body rapidly, is coupled with an electrosurgical generator. The gas creates a
more even distribution of the energy and better sealing of the tissues. There
have been a few reports of serious complications, including gas embolism and
tension pneumothorax. The holmium:YAG laser simultaneously dissects and
coagulates tissue. However, its use may be limited by smoke and by blood
splashing onto the camera lens, and the tissue vaporization and liquid could
promote tumor-cell spillage. The potassium-titanyl-phosphate (KTP) and diode
lasers have shown promise in animal studies. The saline-coupled radiofrequency
tool uses a standard electrosurgical generator to deliver energy through the
conductive fluid. The fluid keeps the surface temperature much lower, increases
the contact area, and reduces char and eschar formation. One caveat for the use
of instruments that coagulate and ablate tissue is that they can damage the
collecting system. Furthermore, the char can make it difficult to assess margin
status. In practice, a combination of instruments, sealants, or both generally is
utilized to obtain hemostasis. These multimodality efforts may be especially
useful in the patient with compromised renal function. On the other hand, the
cost can rise quickly when multiple agents are employed. Combining suturing and
hemostatic technology may be the best strategy.
[Laser-based resecting techniques in the treatment of benign prostatic obstruction] [Article in German] Gross AJ, Bach T. Urologe A. 2008 Apr;47(4):455-60.
A brought variety of options are at hand in the treatment of benign prostatic
obstruction. During the last decades multiple therapeutic approaches have been
pushed on the market to compete with the known Gold-Standard, the monopolar
TUR-P. Only few have stood the test of time. The first wave of laser-based
prostate surgery took place, when the Nd:YAG laser was introduced into clinical
urology. However, operating time was long, surgical outcome often poor and the
risk of serious complications was high. This lead to the vanishing of Nd:YAG
lasers in clinical routine.During the last years, with growing experience in
laser physics and the development of new laser types, the laser-based prostatic
surgery gained importance. In clinical routine different vaporizing or resecting
techniques are established and compete on the market. Aim of this article is to
review those lasers, which are currently used in resection techniques and to
highlight advantages, but also disadvantages of the different systems.
Intravascular lead extraction using the excimer laser: pitfalls and tips for success. Feldtman RW. Semin Vasc Surg. 2008 Mar;21(1):54-6.
Removal of retained pacemaker and defibrillator leads is often indicated in the
face of infection, venous obstruction, or lead malfunction with the need to
upgrade to a newer lead. While simple traction is often successful in newly
placed or infected leads, chronic leads can be problematic in their removal. The
laser extraction sheath offers a method for removal by "cutting" through scar
tissue. This device can be potentially hazardous, so the laser lead extraction
procedures should be performed in a properly equipped operating room for
immediate cardiothoracic surgical intervention should massive bleeding occur.
This article outlines a few suggestions for avoiding severe complications with
this useful procedure.
[Hypertrichosis] [Article in German] Trüeb RM. Hautarzt. 2008 Apr;59(4):325-37; quiz 338.
Hypertrichosis denotes growth of hair on any part of the body in excess of the
amount usually present in persons of the same age, race, and sex, excluding
androgen-dependent hair growth. Hypertrichosis may be an isolated finding or
associated with a syndrome, be associated with additional congenital anomalies or
a marker for systemic disease. In order to diagnose it accurately, the age of
onset, type, localization and pattern of hair growth, associated disorders,
medications and perhaps associated anomalies and family history should be
considered. Even though hypertrichosis usually has limited medical significance,
it often causes cosmetic embarrassment, often resulting in a significant
emotional burden. Treatment options are available, though limited in terms of
efficacy and patient satisfaction. No single method of hair removal is
appropriate for all body locations and patients, and the one adopted will depend
on the type, area, and amount of excessive hair growth, as well as on the age,
sex, and personal preference of the patient. Patients with hypertrichosis should
be adequately advised of the treatment modalities. These include cosmetic
procedures (bleaching, trimming, shaving, plucking, waxing, chemical epilatories,
electrosurgical epilation), and hair removal using light sources and lasers.
Single molecule measurements and molecular motors. Yanagida T, Iwaki M, Ishii Y. Philos Trans R Soc Lond B Biol Sci. 2008 Jun 27;363(1500):2123-34.
Single molecule imaging and manipulation are powerful tools in describing the
operations of molecular machines like molecular motors. The single molecule
measurements allow a dynamic behaviour of individual biomolecules to be measured.
In this paper, we describe how we have developed single molecule measurements to
understand the mechanism of molecular motors. The step movement of molecular
motors associated with a single cycle of ATP hydrolysis has been identified. The
single molecule measurements that have sensitivity to monitor thermal fluctuation
have revealed that thermal Brownian motion is involved in the step movement of
molecular motors. Several mechanisms have been suggested in different motors to
bias random thermal motion to directional movement.
[Laser vaporization of the prostate: all as it should be?] [Article in German] Reich O, Seitz M. Urologe A. 2008 Apr;47(4):461-2, 464-6.
Laser vaporization of the prostate currently occupies a prominent place among the
surgical options for treatment of benign prostatic syndrome. Particularly the
so-called GreenLight laser vaporization with the KTP (80 W) or LBO (120 W) laser
has become remarkably widespread throughout the world. There are already 100 of
these GreenLight laser systems in use in Germany alone. The introduction of a
separate DRG for "laser vaporization" is expected to further increase the
significance of this surgical technique. The aim of this study is to evaluate
laser vaporization as a whole and to identify possible differences between the
Clinical application of erbium:YAG laser in periodontology. Ishikawa I, Aoki A, Takasaki AA. J Int Acad Periodontol. 2008 Jan;10(1):22-30.
Various lasers have been introduced for the treatment of oral diseases and their
applications in dental clinics have become a topic of much interest among
practitioners. Technological advances and improvements have increased the choices
of the available laser systems for oral use. Among them, a recently developed
erbium-doped:yttrium aluminum garnet (Er:YAG) laser system possesses suitable
characteristics for oral soft and hard tissue ablation. Due to its high
absorption in water, an effective ablation with a very thin surface interaction
occurs on the irradiated tissues without any major thermal damage to the
irradiated and surrounding tissues. In the field of periodontics, the application
of Er:YAG laser for periodontal hard tissue has begun with studies from Japanese
and German researchers. Several in vitro and clinical studies have already
demonstrated an effective application of the Er:YAG laser for calculus removal
and decontamination of the diseased root surface in periodontal non-surgical and
surgical procedures. However, further studies are required to better understand
the various effects of Er:YAG laser irradiation on biological tissues for its
safe and effective application during periodontal and implant therapy. Randomized
controlled clinical trials and more basic studies have to be encouraged and
performed to confirm the status of Er:YAG laser treatment as an adjunct or
alternative to conventional mechanical periodontal therapy. In this paper, the
advantages and current clinical applications of this laser in periodontics and
implant dentistry are summarized based on current scientific evidence.
Guidelines for laser hair removal. Casey AS, Goldberg D. J Cosmet Laser Ther. 2008 Mar;10(1):24-33.
Requests for removal of unwanted body hair are common in dermatologic and
surgical practices. Technology continues to improve the achievement of a more
permanent reduction through the use of lasers. Despite the increased use of
lasers, to date, few guidelines exist in terms of how to approach laser hair
removal. Specifically, one must understand the mechanism of hair growth and how
lasers work to target the hair follicle. There is significant variation among
practitioners in pre-and post-laser recommendations to patients as well as
intervals between treatment sessions. We performed a thorough review of the
literature in order to determine evidence for the ideal interval between
treatment sessions and the ideal number of sessions. We also sought to establish,
based on published reports, the recommendations for shaving, plucking, waxing or
other hair removal methods prior to laser hair removal and the guidelines for sun
exposure before and after laser treatments. Finally, we searched the literature
to find out whether there are areas that should not be treated with laser hair
removal. The evidence and recommendations in this article aim to help guide
practitioners in their approach to laser hair removal.
Laser hair removal pearls. Tierney EP, Goldberg DJ. J Cosmet Laser Ther. 2008 Mar;10(1):17-23.
A number of lasers and light devices are now available for the treatment of
unwanted hair. The goal of laser hair removal is to damage stem cells in the
bulge of the follicle through the targeting of melanin, the endogenous
chromophore for laser and light devices utilized to remove hair. The competing
chromophores in the skin and hair, oxyhemoglobin and water, have a decreased
absorption between 690 nm and 1000 nm, thus making this an ideal range for laser
and light sources. Pearls of laser hair removal are presented in this review,
focusing on four areas of recent development: 1 treatment of blond, white and
gray hair; 2 paradoxical hypertrichosis; 3 laser hair removal in children; and 4
comparison of lasers and IPL. Laser and light-based technologies to remove hair
represents one of the most exciting areas where discoveries by dermatologists
have led to novel treatment approaches. It is likely that in the next decade,
continued advancements in this field will bring us closer to the development of a
more permanent and painless form of hair removal.
Fundus autofluorescence imaging: review and perspectives. Schmitz-Valckenberg S, Holz FG, Bird AC, Spaide RF. Retina. 2008 Mar;28(3):385-409.
Fundus autofluorescence (FAF) imaging is a novel imaging method that allows
topographic mapping of lipofuscin distribution in the retinal pigment epithelium
cell monolayer as well as of other fluorophores that may occur with disease in
the outer retina and the subneurosensory space. Excessive accumulation of
lipofuscin granules in the lysosomal compartment of retinal pigment epithelium
cells represents a common downstream pathogenetic pathway in various hereditary
and complex retinal diseases, including age-related macular degeneration. FAF
imaging has been shown to be useful with regard to understanding of
pathophysiologic mechanisms, diagnostics, phenotype-genotype correlation,
identification of predictive markers for disease progression, and monitoring of
novel therapies. FAF imaging gives information above and beyond that obtained by
conventional imaging methods, such as fundus photography, fluorescein
angiography, and optical coherence tomography. Its clinical value coupled with
its simple, efficient, and noninvasive nature is increasingly appreciated. This
review summarizes basic principles and FAF findings in various retinal diseases.
[Safety problems of modern laser medical equipment] [Article in Russian] Pal'tsev IuP, Kravchenko OK, Levina AV. Med Tr Prom Ekol. 2007;(12):12-6.
The authors consider topics connected with improvement of hygienic regulation of
laser radiation, define most important problems associated with safety of modern
laser medical devices.
Spindle cell carcinoma of the palatine tonsil: report of a diagnostic pitfall and literature review. Minami SB, Shinden S, Yamashita T. Am J Otolaryngol. 2008 Mar-Apr;29(2):123-5.
Spindle cell carcinomas of the tonsil are very rare tumors. We present an
additional case that occurred in a 58-year-old woman. She presented with a tumor
of the right tonsil. Histologic sections of tonsillar biopsies suggested that
this tumor was a squamous cell carcinoma. She underwent a transoral resection of
the right oropharynx. The final diagnosis was spindle cell carcinoma. We
emphasize the difficulties in diagnosing this type of tumor and discuss
therapeutic approaches to this rare tumor, which shows little response to
radiotherapy; the literature is reviewed. We offer this case study in an effort
to increase awareness of this rare malignancy.
Nonviral gene transfection nanoparticles: function and applications in the brain. Roy I, Stachowiak MK, Bergey EJ. Nanomedicine. 2008 Jun;4(2):89-97. Epub 2008 Mar 3.
In vivo transfer and expression of foreign genes allows for the elucidation of
functions of genes in living organisms and generation of disease models in
animals that more closely resemble the etiology of human diseases. Gene therapy
holds promise for the cure of a number of diseases at the fundamental level.
Synthetic "nonviral" materials are fast gaining popularity as safe and efficient
vectors for delivering genes to target organs. Not only can nanoparticles
function as efficient gene carriers, they also can simultaneously carry
diagnostic probes for direct "real-time" visualization of gene transfer and
downstream processes. This review has focused on the central nervous system (CNS)
as the target for nonviral gene transfer, with special emphasis on organically
modified silica (ORMOSIL) nanoparticles developed in our laboratory. These
nanoparticles have shown robust gene transfer efficiency in brain cells in vivo
and allowed to investigate mechanisms that control neurogenesis as well as
[Application of brilliant x-rays in mammography. Development and perspectives of phase contrast techniques] [Article in German] Schneider T, Coan P, Habs D, Reiser M. Radiologe. 2008 Apr;48(4):345-50.
The early and reliable detection of breast cancer is often difficult with
conventional mammography, especially within dense breast parenchyma. An
alternative approach using x-rays are phase-sensitive imaging techniques, which
are able to visualize the borders of tissues with different refraction indices
with very high contrast. These phase contrast imaging techniques can generate
projection images with much less glandular dose than conventional mammography.
Even the acquisition of phase contrast CT data sets with an acceptable exposure
dose is possible. As brilliant x-ray beams are required for phase contrast
imaging, which up to now were only available at synchrotron facilities, these
methods were restricted to only a few laboratories. However, with the advent of
newly developed high intensity lasers which are also able to produce such
radiation, a widespread and affordable use of this technique seems realistic. The
further development of phase contrast imaging is funded by the excellence cluster
MAP of the Munich universities.
Use of CO2 laser as an adjunctive treatment for caudal stomatitis in a cat. Lewis JR, Tsugawa AJ, Reiter AM. J Vet Dent. 2007 Dec;24(4):240-9.
Lasers have become a popular tool in veterinary practice, particularly the carbon
dioxide (CO2) laser. In humans, the CO2 laser is used most commonly in oral and
maxillofacial soft tissue surgery due to its favorable interactions with oral
soft tissues. Other types of lasers are better suited for use on hard tissues
such as enamel and dentin. This article reviews the history of laser use, physics
of laser-tissue interaction, delivery systems, and laser types used in dentistry
and oral surgery. This is followed by a case report describing the use of CO2
laser as an adjunctive treatment for therapy of refractory caudal stomatitis in a
Recurrent corneal erosion: characteristics and management options. Kirkwood BJ. Insight. 2007 Oct-Dec;32(4):14-7; quiz 18-9.
Recurrent corneal erosion is a relatively common condition characterized by one
or more episodes of spontaneous breakdown of the corneal epithelium. It
classically occurs at the time of awakening and individual episodes may vary in
severity and duration of symptoms. Classification as either primary or secondary
depends on whether the defect in the epithelial basement membrane is intrinsic or
acquired. The characteristics of this condition will be discussed and various
medical and surgical management strategies will be reviewed. This will provide
greater understanding in the care of patients with this condition as ophthalmic
nurses and technicians.
Ultraviolet femtosecond laser ionization mass spectrometry. Imasaka T. Chem Rec. 2008;8(1):23-32.
For this study, multiphoton ionization/mass spectrometry using an ultraviolet
(UV) femtosecond laser was employed for the trace analysis of organic compounds.
Some of the molecules, such as dioxins, contain several chlorine atoms and have
short excited-state lifetimes due to a "heavy atom" effect. A UV femtosecond
laser is, then, useful for efficient resonance excitation and subsequent
ionization. A technique of multiphoton ionization using an extremely short laser
pulse (e.g., <10 fs), referred to as "impulsive ionization," may have a potential
for use in fragmentation-free ionization, thus providing information on molecular
weight in mass spectrometry. 2008 The Japan Chemical Journal Forum and Wiley
New developments in scanning laser polarimetry for glaucoma. Lemij HG, Reus NJ. Curr Opin Ophthalmol. 2008 Mar;19(2):136-40.
PURPOSE OF REVIEW: Scanning laser polarimetry is a technique that is used to
evaluate the thickness of the retinal nerve fiber layer. It has been shown to
have a high accuracy for diagnosing glaucoma. In a subset of eyes, atypical
retardation patterns may be present that do not match the expected retinal nerve
fiber layer appearance. This review summarizes recent advances made to reduce the
frequency and severity of these patterns. In addition, recent progress in the
development of algorithms for detecting progression is discussed. RECENT
FINDINGS: A new measurement algorithm--enhanced corneal compensation--has been
developed to improve the instrument's signal-to-noise ratio. Enhanced corneal
compensation has been shown to improve the accuracy of scanning laser polarimetry
for diagnosing glaucoma. In addition, enhanced corneal compensation improves the
relationship between standard automated perimetry and scanning laser polarimetry
measurements. Furthermore, research is being done on detecting progression in
glaucoma. Recently, a method for simulating progression has been proposed,
thereby diminishing the need for long-term studies to validate numerous
measurement algorithms. SUMMARY: With enhanced corneal compensation, the
diagnostic accuracy of scanning laser polarimetry has been further improved for
glaucoma. Newly developed algorithms for detecting any progressive retinal nerve
fiber layer thinning await clinical validation.
Combining laser capture microdissection and proteomics techniques. Mustafa D, Kros JM, Luider T. Methods Mol Biol. 2008;428:159-78.
Laser microdissection is an effective technique to harvest pure cell populations
from complex tissue sections. In addition to using the microdissected cells in
several DNA and RNA studies, it has been shown that the small number of cells
obtained by this technique can also be used for proteomics analysis. Combining
laser capture microdissection and different types of mass spectrometers opened
ways to find and identify proteins that are specific for various cell types,
tissues, and their morbid alterations. Although the combination of
microdissection followed by the currently available techniques of proteomics has
not yet reached the stage of genome wide representation of all proteins present
in a tissue, it is a feasible way to find significant differentially expressed
proteins in target tissues. Recent developments in mass spectrometric detection
followed by proper statistics and bioinformatics enable to analyze the proteome
of not more than 100-200 cells. Obviously, validation of result is essential. The
present review describes and discusses the various methods developed to target
cell populations of interest by laser microdissection, followed by analysis of
Biological activity of hemoprotein nitrosyl complexes. Osipov AN, Borisenko GG, Vladimirov YA. Biochemistry (Mosc). 2007 Dec;72(13):1491-504.
Chemical and biological functions of hemoprotein nitrosyl complexes as well as
their photolysis products are discussed in this review. Chemical properties of
nitric oxide are discussed, and major chemical reactions such as interaction with
thiols, free radicals, and transition metals are considered. Specific attention
is paid to the generation of hemoprotein nitrosyl complexes. The mechanisms of
nitric oxide reactions with hemoglobin and cytochrome c and physicochemical
properties of their nitrosyl complexes are discussed. A review of photochemical
reactions of nitrosyl complexes with various ligands is given. Finally, we
observe physiological effects of visible radiation on hemoprotein nitrosyl
complexes: smooth muscle relaxation and reactivation of mitochondrial
Permanent makeup: indications and complications. De Cuyper C. Clin Dermatol. 2008 Jan-Feb;26(1):30-4.
Cosmetic tattoos, simulating makeup, have become very popular in the last
decades; the technique of micropigmentation consists of implantation of pigment
into the skin using a tattoo pen. The procedure can also be used to camouflage
vitiligo, to mask scars, and as an adjunct to reconstructive surgery. Risks and
complications include infections, allergic reactions, scarring, fanning, fading,
and dissatisfaction about color and shape. Lasers offer the best cosmetic result
for removal of unwanted tattoos.
Excimer laser-assisted nonocclusive anastomosis. An emerging technology for use in the creation of intracranial-intracranial and extracranial-intracranial cerebral bypass. Langer DJ, Van Der Zwan A, Vajkoczy P, Kivipelto L, Van Doormaal TP, Tulleken CA. Neurosurg Focus. 2008;24(2):E6.
Excimer laser-assisted nonocclusive anastomosis (ELANA) has been developed over
the past 14 years for assistance in the creation of intracranial bypasses. The
ELANA technique allows the creation of intracranial-intracranial and
extracranial-intracranial bypasses without the need for temporary occlusion of
the recipient artery, avoiding the inherent risk associated with occlusion time.
In this review the authors discuss the technique and its indications, while
reviewing the clinical results of the procedure. The technique itself is
explained using cartoon drawings and intraoperative photographs. Advantages and
disadvantages of the technique are also discussed.
[Medical apparatuses based on gas lasers] [Article in Russian] Grachev VA, Kernosov MIu, Kondrakhin AA, Solov'eva LI, Trusov VS, Chuliaeva EG. Med Tekh. 2007 Nov-Dec;(6):27-30.
Medical laser apparatuses available from Plasma, Ltd., are reviewed. The effects
of therapeutic physical factors provided by these apparatuses on the pathological
processes in human body are concisely described. Technical characteristics of the
apparatuses are specified.
Endoscopic management of adult orthotopic ureterocele and associated calculi with holmium laser: experience with 16 patients over 4 years and review of literature. Shah HN, Sodha H, Khandkar AA, Kharodawala S, Hegde SS, Bansal M. J Endourol. 2008 Mar;22(3):489-96.
PURPOSE: To retrospectively evaluate the safety and effectiveness of holmium
laser endoscopic incision and laser lithotripsy in adults with orthotopic
ureterocele and associated calculi. PATIENTS AND METHODS: From May 2003 to August
2007 at our center, 16 adults underwent transurethral incision of an ureterocele
and intracorporeal holmium laser lithotripsy for associated calculi. The
perioperative data of these patients were retrospectively analyzed. The
literature was reviewed to identify all the reported options for management of
this relatively rare condition. RESULTS: Ureterocele was associated with a single
system in 13 patients. Two patients had bilateral ureteroceles. Four patients had
associated upper tract stones. The procedure was uneventful in all patients. The
average postoperative hospital stay was 19.3 hours. All patients were stone free
after the procedure. Eleven patients were available for follow-up at 3 and 6
months. None of these patients had any evidence of residual ureterocele and/or
hydronephrosis when evaluated with intravenous urography at 3 months. Micturating
cystourethrography (MCU) at 3 months revealed low-grade vesicoureteral reflux
(VUR) in four patients; no reflux was found with MCU at 6 months. CONCLUSIONS:
Laser endoscopic management of adult orthotopic ureterocele and associated
calculi effectively decompressed ureterocele and removed stones in all patients
without any significant postoperative morbidity. Low-grade VUR that may occur
postoperatively resolved at 6 months. A literature review suggests that the
ability of the holmium laser to manage both ureterocele and calculi
simultaneously should make holmium laser management a procedure of choice at
centers that possess the equipment.
Physiological heterogeneity in biofilms. Stewart PS, Franklin MJ. Nat Rev Microbiol. 2008 Mar;6(3):199-210.
Biofilms contain bacterial cells that are in a wide range of physiological
states. Within a biofilm population, cells with diverse genotypes and phenotypes
that express distinct metabolic pathways, stress responses and other specific
biological activities are juxtaposed. The mechanisms that contribute to this
genetic and physiological heterogeneity include microscale chemical gradients,
adaptation to local environmental conditions, stochastic gene expression and the
genotypic variation that occurs through mutation and selection. Here, we discuss
the processes that generate chemical gradients in biofilms, the genetic and
physiological responses of the bacteria as they adapt to these gradients and the
techniques that can be used to visualize and measure the microscale physiological
heterogeneities of bacteria in biofilms.
Photoepilation: a growing trend in laser-assisted cosmetic dermatology. Nouri K, Vejjabhinanta V, Patel SS, Singh A. J Cosmet Dermatol. 2008 Mar;7(1):61-7.
Excess hair is an age-old condition plaguing both men and women alike, of all
races. Conditions such as hirsutism or hypertrichosis, procedures that involve
grafted donor sites, transsexual transformations from male to female, and
genetics are all responsible for excess or unwanted hair. Previous options for
people seeking to remove or lessen the presence of hair have either been painful
or resulted in short-term hair removal. With the recent advent of laser
technology, hair removal has been added to the many capabilities of the new
generation nonablative lasers and light systems. Lasers are not yet a permanent
solution for hair removal, but they are able to provide a safe, fast, and
effective method of hair reduction.
Effects of visible light on the skin. Mahmoud BH, Hexsel CL, Hamzavi IH, Lim HW. Photochem Photobiol. 2008 Mar-Apr;84(2):450-62. Epub 2008 Jan 29.
Electromagnetic radiation has vast and diverse effects on human skin. Although
photobiologic studies of sunlight date back to Sir Isaac Newton in 1671, most
available studies focus on the UV radiation part of the spectrum. The effects of
visible light and infrared radiation have not been, until recently, clearly
elucidated. The goal of this review is to highlight the effects of visible light
on the skin. As a result of advances in the understanding of skin optics, and
comprehensive studies regarding the absorption spectrum of endogenous and
exogenous skin chromophores, various biologic effects have been shown to be
exerted by visible light radiation including erythema, pigmentation, thermal
damage and free radical production. It has also been shown that visible light can
induce indirect DNA damage through the generation of reactive oxygen species.
Furthermore, a number of photodermatoses have an action spectrum in the visible
light range, even though most of the currently available sunscreens offer, if
any, weak protection against visible light. Conversely, because of its cutaneous
biologic effects, visible light is used for the treatment of a variety of skin
diseases and esthetic conditions in the form of lasers, intense pulsed light and
Application of laser-capture microdissection to analysis of gene expression in the testis. Sluka P, O'Donnell L, McLachlan RI, Stanton PG. Prog Histochem Cytochem. 2008;42(4):173-201.
The isolation and molecular analysis of highly purified cell populations from
complex, heterogeneous tissues has been a challenge for many years.
Spermatogenesis in the testis is a particularly difficult process to study given
the unique multiple cellular associations within the seminiferous epithelium,
making the isolation of specific cell types difficult. Laser-capture
microdissection (LCM) is a recently developed technique that enables the
isolation of individual cell populations from complex tissues. This technology
has enhanced our ability to directly examine gene expression in enriched
testicular cell populations by routine methods of gene expression analysis, such
as real-time RT-PCR, differential display, and gene microarrays. The application
of LCM has however introduced methodological hurdles that have not been
encountered with more conventional molecular analyses of whole tissue. In
particular, tissue handling (i.e. fixation, storage, and staining), consumables
(e.g. slide choice), staining reagents (conventional H&E vs. fluorescence),
extraction methods, and downstream applications have all required re-optimisation
to facilitate differential gene expression analysis using the small amounts of
material obtained using LCM. This review will discuss three critical issues that
are essential for successful procurement of cells from testicular tissue
sections; tissue morphology, capture success, and maintenance of molecular
integrity. The importance of these issues will be discussed with specific
reference to the two most commonly used LCM systems; the Arcturus PixCell IIe and
PALM systems. The rat testis will be used as a model, and emphasis will be placed
on issues of tissue handling, processing, and staining methods, including the
application of fluorescence techniques to assist in the identification of cells
of interest for the purposes of mRNA expression analysis.
Review of methodological developments in laser Doppler flowmetry. Rajan V, Varghese B, van Leeuwen TG, Steenbergen W. Lasers Med Sci. 2009 Mar;24(2):269-83. Epub 2008 Jan 31.
Laser Doppler flowmetry is a non-invasive method of measuring microcirculatory
blood flow in tissue. In this review the technique is discussed in detail. The
theoretical and experimental developments to improve the technique are reviewed.
The limitations of the method are elaborated upon, and the research done so far
to overcome these limitations is critically assessed.
Evidence-based review of lasers, light sources and photodynamic therapy in the treatment of acne vulgaris. Haedersdal M, Togsverd-Bo K, Wulf HC. J Eur Acad Dermatol Venereol. 2008 Mar;22(3):267-78. Epub 2008 Jan 23.
Background There is a considerable need for effective and safe treatment for acne
vulgaris. Objective In a systematic review with an evidence-based approach to
assess the effects of optical treatments for acne vulgaris. Methods Original
publications of controlled clinical trials were identified through searches in
PubMed and the Cochrane Library. Results A total of 16 randomized controlled
trials (RCT) and 3 controlled trials (CT) were identified, involving a total of
587 patients. Interventions included photodynamic therapy (PDT; 5 RCTs), infrared
lasers (4 RCTs), broad-spectrum light sources (3 RCTs, 1 CT), pulsed dye lasers
(PDL; 2 RCTs, 1 CT), intense pulsed light (IPL; 1 RCTs, 2 CTs), and potassium
titanyl phosphate laser (1 RCT). The randomization method was mentioned in 6 of
16 RCTs, and one trial described adequate allocation concealment. Most trials
were intraindividual trials (12 of 19), which applied blinded response
evaluations (12 of 19) and assessed a short-term efficacy up to 12 weeks after
treatment (17 of 19). Based on the present best available evidence, we conclude
that optical treatments possess the potential to improve inflammatory acne on a
short-term basis with the most consistent outcomes for PDT [up to 68%
improvement, aminolevulinic acid (ALA), methyl-aminolevulinic acid (MAL) and red
light]. IPL-assisted PDT seems to be superior to IPL alone. Only two trials
compare optical vs. conventional treatments, and further studies are needed.
Side-effects from optical treatments included pain, erythema, oedema, crusting,
hyperpigmentation, pustular eruptions and were more intense for treatments
combined with ALA or MAL. Conclusion Evidence from controlled clinical trials
indicates a short-term efficacy from optical treatments for acne vulgaris with
the most consistent outcomes for PDT. We recommend that patients are
preoperatively informed of the existing evidence, which indicates that optical
treatments today are not included among first line treatments.
[Laser treatment of warts] [Article in German] Ockenfels HM, Hammes S. Hautarzt. 2008 Feb;59(2):116-23.
Human papilloma viruses (HPV) lead to common warts in 5% of the population and
genital warts in 1% of sexually-active individuals. Although about 50% of HPV
infections regress spontaneously, the course is uncertain. Expectant waiting
often leads to progression and dissemination. Plantar warts may cause pain on
walking, while palmar and genital warts may impair social contacts. There are
many treatments for warts, including a variety of laser systems. The CO(2) laser
is the best ablative approach, producing cure rates of up to 75% for
therapy-resistant common warts in cohort and case-control studies. Side effects
such as bleeding, pain and reduced function over weeks must be weighed against
the likelihood of success. Considering non-ablative approaches, pulsed dye lasers
can be used for a selective, non-bloody destruction of extragenital and genital
warts and may become the treatment of choice. In prospective randomized studies,
they produced cure rates of up to 82% for therapy-resistant warts with few side
[Side effects of therapy with flashlamps and lasers] [Article in German] Stangl S, Kimmig W. Hautarzt. 2008 Feb;59(2):108-15.
Dermatologic flashlamp and laser therapy involves photochemical, thermal,
photoablative, photoacoustic and phtoodisruptive effects, depending on the wave
length, energy density and pulse duration. All of these effects when properly
employed can lead to optimal dermatologic and cosmetic results. They also carry a
high risk for side effects and damage when not properly used. The risk of side
effects depends greatly on the training and experience of the treating physician.
Both a solid dermatologic training in order to correctly diagnosis skin changes
and knowledge of laser principles are required.
Corneal ectasia after laser vision correction. Caster AI, Trattler W. Int Ophthalmol Clin. 2008 Winter;48(1):73-81.
LASIK flap revision using the IntraLase femtosecond laser. Tran DB, Binder PS, Brame CL. Int Ophthalmol Clin. 2008 Winter;48(1):51-63.
Femtodynamics: optimizing femtosecond laser settings and procedure techniques to optimize outcomes. Faktorovich EG. Int Ophthalmol Clin. 2008 Winter;48(1):41-50.
Prevention and treatment of haze in refractive surgery. Parekh P, Davis EA. Int Ophthalmol Clin. 2008 Winter;48(1):29-40.
Surface ablation. Lacayo GO 3rd, Randleman JB. Int Ophthalmol Clin. 2008 Winter;48(1):17-28.
The optimization of LASIK. Probst LE. Int Ophthalmol Clin. 2008 Winter;48(1):9-16.
Update on flexible ureteroscopy. Buscarini M, Conlin M. Urol Int. 2008;80(1):1-7. Epub 2008 Jan 18.
OBJECTIVE: An update on ureteroscopy with focus on current technology and newer
instrumentation is presented. METHODS: A literature search through
Medline-indexed journals as well as personal comments are included in this
review. Topics such as new semirigid and flexible ureteroscopes, lasers, ureteral
access sheats, wires and stone extraction devices are outlined. RESULTS: Thanks
to the continuous advances of technology and miniaturization of instruments,
ureteroscopy is an ever-expanding field. A clear outline of the available
instruments and techniques with reference to published results catches the status
of this dynamic field. CONCLUSIONS: Urologists are faced with a host of new
products related to ureteroscopy every year. This review serves to identify the
most useful and proven advances in the field and helps in selecting the equipment
needed for a successful minimally invasive approach to upper urinary tract
pathologies. (c) 2008 S. Karger AG, Basel.
Adult keratoplasty: has the prognosis improved in the last 25 years? Price FW, Price MO. Int Ophthalmol. 2008 Jun;28(3):141-6.
Adult keratoplasty outcomes have significantly improved in the past quarter
century as a result of new pharmaceuticals, advanced surgical devices, better
understanding of what causes graft failure, and targeted techniques for selective
replacement of only diseased corneal layers. Prevention and treatment of graft
rejection, which has long been a leading cause of graft failure, has improved
with the development of innovative topical and systemic immuno-suppressants. New
methods for preventing and treating ocular surface complications have been
devised, and limbal stem cell grafts have significantly improved management of
severe ocular surface disease. Improved intraocular lens designs cause less
corneal damage and have increased corneal graft survival. Non-steroidal
anti-inflammatory (NSAID) eyedrops and more complete vitrectomies have reduced
the incidence of chronic cystoid macular edema, which could prevent eyes with
clear grafts from regaining useful vision. Patients with keratoconus or corneal
scars can now benefit from advanced anterior lamellar keratoplasty techniques,
which reduce the risk of immunologic rejection and endothelial failure, while
matching the visual outcomes achieved with penetrating keratoplasty. Patients
with endothelial dysfunction can now benefit from advanced endothelial
keratoplasty techniques, which provide more rapid visual recovery, minimize
induced astigmatism and ocular surface problems, and virtually eliminate the risk
of wound rupture from minor trauma. Finally, femtosecond lasers now provide
transplant surgeons with a precise tool for creating complex, interlocking
corneal incisions that may facilitate wound healing.
Laser lead extraction and baffle stenting to facilitate dual chamber implantable defibrillator upgrade in a patient with L-transposition of the great arteries status-post Senning/Rastelli repair: a case report and review of literature. Undavia M, Love B, Gomes JA, Epstein LM, Mehta D, Fischer A. Pacing Clin Electrophysiol. 2008 Jan;31(1):131-4.
A case of successful laser extraction of a defibrillator lead with baffle
stenting in a 15-year-old boy with dextrocardia, L-transposition, ventricular
septal defect, and pulmonic stenosis status-post Senning/Rastelli repair is
presented. Six-month follow-up revealed a significant increase in exercise
tolerance and maximum oxygen consumption (VO(2)max).
Detection of cancer-related proteins in fresh-frozen ovarian cancer samples using laser capture microdissection. Silasi DA, Alvero AB, Mor J, Chen R, Fu HH, Montagna MK, Mor G. Methods Mol Biol. 2008;414:35-45.
Tumors are heterogeneous structures that contain different cell populations.
Laser capture microdissection (LCM) can be used to obtain pure cancer cells from
fresh-frozen cancer tissue and the surrounded environment, thus providing an
accurate snapshot of the tumor and its microenvironment in vivo. We describe a
new approach to isolate pure cancer cell population and evaluate protein
expression. The process includes immunocytochemistry, laser microdissection, and
western blot analysis. Using this technique, we can detect proteins such as
X-linked inhibitor of apoptosis protein (XIAP) and Fas ligand (FasL) with as
little as 1000 cells.
Photodynamic therapy--indications and limits in malignant tumors treatment. Filip AG, Clichici S, Daicoviciu D, Olteanu D, Mureşan A, Dreve S. Rom J Intern Med. 2008;46(4):285-93.
Photodynamic therapy (PDT) is a very promising technique used for the treatment
of a variety of solid neoplasms, based on the formation of singlet oxygen induced
by a photosensitizer after irradiation with visible light. The mechanism of
interaction of the photosensitizers and light is discussed, along with the
effects produced in the target tissue. PDT has been approved in many countries
for the treatment of lung, esophageal, bladder, skin and head and neck cancers.
The antitumor effects of this treatment result from the combination of direct
tumor cell photodamage, destruction of tumor vasculature and activation of an
immune response. The present status of clinical PDT is discussed along with the
newer photosensitizers being used and their clinical roles. Despite the promising
results from earlier clinical trials of PDT considerable additional work is
needed to bring this new modality of treatment into modern clinical practice.
A fibrin-related line of research and theoretical possibilities for the use of fibrin glue as a temporary basal membrane in non-perforated corneal ulcers and in photorefractive keratectomy (PRK)-operated corneas. Bonatti JA, Bechara SJ, Dall'Col MW, Cresta FB, Carricondo PC, Kara-José N. Arq Bras Oftalmol. 2007 Sep-Oct;70(5):884-9.
PURPOSE: To report a specific line of research developed at the University of São
Paulo/Brazil on fibrin glue used for sealing corneal perforations and the
perspectives of use on non-perforated corneal ulcers and photorefractive
keratectomy-operated corneas. METHODS: To describe fibrin glue manufacture,
development of a device to test the glued perforated corneal area resistance,
subsequent experimental investigations of the use of the fibrin glue in corneal
perforations, reporting its efficacy, mechanical resistance experiments and
histological study. Finally, the medical literature basis is searched to propose
studies on the use of fibrin as a temporary basal membrane on non-perforated
corneal surfaces like non-infectious corneal ulcers and on post-photorefractive
keratectomy corneal surfaces. RESULTS: The development of fibrin glue, the device
for resistance experiments, the efficacy, resistance and histological studies on
fibrin glue used for sealing corneal perforations are reported as well as the
scientific literature basis for the proposed studies on the use of fibrin as a
temporary basal membrane on non-perforated corneas like non-perforated corneal
ulcers and photorefractive keratectomy corneal surfaces. CONCLUSION: A specific
line of research was reported on fibrin glue to seal corneal perforations at the
University of São Paulo/Brazil and the theoretical perspectives for the use of
fibrin in non-perforated corneal ulcers and on photorefractive
keratectomy-operated corneas in an attempt to reduce corneal haze.
Refractive enhancement following presbyopia-correcting intraocular lens implantation. Macsai MS, Fontes BM. Curr Opin Ophthalmol. 2008 Jan;19(1):18-21.
PURPOSE OF REVIEW: Presbyopia-correcting intraocular lenses are widely available.
Residual ametropia is one of the most common issues that can result in patient
dissatisfaction. Options for correcting refractive surprises include piggyback
intraocular lens implantation, corneal incisional surgery and laser correction.
Excimer laser surgery is a safe and predictable method to correct residual
amounts of ametropia in pseudophakic patients with monofocal intraocular lenses;
however, there is scant published literature regarding this technique. RECENT
FINDINGS: Presbyopia-correcting intraocular lenses require emmetropia for the
best visual outcome, as small amounts of astigmatism or residual refractive
errors can limit their visual performance. Laser-assisted in-situ keratomileusis
and photorefractive keratectomy are safe and effective results in pseudophakic
patients. Surgeons can refine the refractive outcome after intraocular lens
implantation with the excimer laser to achieve better results and higher patient
satisfaction. SUMMARY: Excimer laser corneal surgery for fine-tuning residual
ametropia after presbyopia-correcting intraocular lenses is a safe adjunct
treatment to increase patient satisfaction. Which technique (photorefractive
keratectomy or laser-assisted in-situ keratomileusis) to use depends on surgeon
preference and patient characteristics, as both demonstrate similar results in
published literature. Knowledge of all available refractive methods and
technologies are crucial for improving outcomes in these patients.
Greenlight laser in benign prostatic hyperplasia: turning green into gold. Alivizatos G, Skolarikos A. Curr Opin Urol. 2008 Jan;18(1):46-9.
PURPOSE OF REVIEW: The purpose of this review is to present recent clinical data
published upon the photoselective vaporization of the prostate procedure and
introduce new ideas about the future influence of this new technology upon the
treatment of benign prostatic hyperplasia. RECENT FINDINGS: Published studies
have provided significant evidence that the photoselective vaporization of the
prostate laser procedure is efficient, safe, easy to learn and early results show
that it can compete with transurethral resection of the prostate. The major
advantages of this technique are that it is a bloodless procedure, the patient
goes home after a few hours and it can be applied to all patient categories. The
cost of the photoselective vaporization of the prostate procedure is being
investigated and a few studies addressing this issue seem to conclude that this
surgical option is a cost effective decision. Lately, thoughts about early
surgical intervention with the photoselective vaporization of the prostate laser
are being expressed but properly designed studies are needed. SUMMARY: The
photoselective vaporization of the prostate laser procedure is getting worldwide
fast recognition and it is the first time that transurethral resection of the
prostate and open prostatectomy are being threatened. The cost of this procedure
is being examined but it is difficult to draw solid conclusions since
reimbursement strategies differ between various countries.
Holmium laser for benign prostatic hyperplasia. Seki N, Naito S. Curr Opin Urol. 2008 Jan;18(1):41-5.
PURPOSE OF REVIEW: The following review provides an overview of the current
status, while focusing on the surgical techniques associated with the holmium
laser for the treatment of benign prostatic hyperplasia. RECENT FINDINGS: A
systematic Medline database search, with a focus on articles about surgical
treatment with holmium laser for benign prostatic hyperplasia, provided some new
data concerning holmium laser enucleation of the prostate. On the other hand, new
interesting data concerning both resection and ablation techniques using the
holmium laser have only been sparsely reported during this review period.
SUMMARY: Holmium laser enucleation of the prostate is a safe procedure for
treating not only patients without co-morbidities but also patients with urinary
retention or who are on anticoagulants. Holmium laser enucleation of the prostate
can be performed on prostates of all sizes with significantly less morbidity.
Although holmium laser enucleation of the prostate represents a state-of-the-art
procedure, a prolonged learning curve has still prevented the widespread adoption
of this device in the urological community.
Open adenomectomy: past, present and future. Noguera RS, Rodríguez RC. Curr Opin Urol. 2008 Jan;18(1):34-40.
PURPOSE OF REVIEW: Open surgery has been the gold standard for the treatment of
benign, symptomatic, large volume prostatic hyperplasia. Recent data series,
however, have demonstrated that a minimally invasive approach can be used for the
treatment of this pathology while duplicating the results of the open technique.
This review will describe the different surgical techniques that have been used
through the last century for the treatment of benign prostatic hyperplasia,
highlighting the advantages and disadvantages of each approach. RECENT FINDINGS:
Surgical management for symptomatic benign prostatic hyperplasia has made a
journey from an open approach to robotic surgery. Modifications of the gold
standard transurethral resection have been incorporated into clinical practice
and include bipolar transurethral resection as well as holmium laser resection
and potassium titanyl phosphate laser vaporization. Minimally invasive ablative
techniques have also been popularized and include transurethral needle ablation
and thermotherapy. Most recently, laparoscopy has demonstrated to be a feasible,
safe, reproducible technique that can create similar outcomes to an open
technique whilst maintaining the advantages of a minimally invasive approach.
Although the future will see greater use of robotics, larger series are needed to
prove the advantages of this technology. SUMMARY: Minimally invasive approaches
for the treatment of symptomatic benign giant prostatic hyperplasia are replacing
open surgery, which has been the gold standard for the surgical treatment of this
pathology, duplicating its results with a lower morbidity. Recently we have seen
a growing amount of experience treating this disease state with
laparoscopic/robotics and the advantages it provides may permit the
popularization of this technique.
Holmium laser enucleation of the prostate (HoLEP). Gilling P. BJU Int. 2008 Jan;101(1):131-42.
Dynamic imaging of molecules using high order harmonic generation. Marangos JP, Baker S, Kajumba N, Robinson JS, Tisch JW, Torres R. Phys Chem Chem Phys. 2008 Jan 7;10(1):35-48. Epub 2007 Nov 14.
We review recent progress towards imaging the electronic wavefunctions and
nuclear dynamics of small molecules using the high order harmonics emitted when a
molecule experiences an intense laser field. We illustrate that the essence of
high harmonic emission is contained in the recombination amplitude between the
continuum portion of the electronic wavefunction, that is formed through field
ionization and which is accelerated and driven back to recollide in the laser
field, and the bound electronic state. We review for the non-specialist some
recent experimental and theoretical work dealing with high harmonic generation
(HHG) in molecules. Particular attention is paid to two types of experiment
recently performed in our group. The first of these types of experiment is the
measurement of signatures of molecular electronic structure using HHG from
molecules with a fixed orientation in space. The second is the use of HHG to
track extremely fast proton rearrangement following ionization in light
molecules, using the intrinsic temporal variation of the recolliding electron
energy to extract these dynamics from measurements of the high harmonics.
"Imaging" combustion chemistry via multiplexed synchrotron-photoionization mass spectrometry. Taatjes CA, Hansen N, Osborn DL, Kohse-Höinghaus K, Cool TA, Westmoreland PR. Phys Chem Chem Phys. 2008 Jan 7;10(1):20-34. Epub 2007 Nov 6.
The combination of multiplexed mass spectrometry with photoionization by
tunable-synchrotron radiation has proved to be a powerful tool to investigate
elementary reaction kinetics and the chemistry of low-pressure flames. In both of
these applications, multiple-mass detection and the ease of tunability of
synchrotron radiation make it possible to acquire full sets of data as a function
of mass, photon energy, and of the physical dimension of the system, e.g.
distance from the burner or time after reaction initiation. The data are in
essence an indirect image of the chemistry. The data can be quantitatively
correlated and integrated along any of several dimensions to compare to
traditional measurements such as time or distance profiles of individual chemical
species, but it can also be directly interpreted in image form. This perspective
offers an overview of flame chemistry and chemical kinetics measurements that
combine tunable photoionization with multiple-mass detection, emphasizing the
overall insight that can be gained from multidimensional data on these systems.
The low-pressure flame apparatus is capable of providing isomer-resolved mass
spectra of stable and radical species as a function of position in the flame. The
overall chemical structure of the flames can be readily seen from images of the
evolving mass spectrum as distance from the burner increases, with
isomer-specific information given in images of the photoionization efficiency.
Several flames are compared in this manner, with a focus on identification of
global differences in fuel-decomposition and soot-formation pathways. Differences
in the chemistry of flames of isomeric fuels can be discerned. The application of
multiplexed synchrotron photoionization to elementary reaction kinetics permits
identification of time-resolved isomeric composition in reacting systems. The
power of this technique is illustrated by the separation of direct and
dissociative ionization signals in the reaction of C(2)H(5) with O(2); by the
resolution of isomeric products in reactions of the ethynyl (C(2)H) radical; and
by preliminary observation of branching to methyl + propargyl products in the
self-reaction of vinyl radicals. Finally, prospects for future research using
multiplexed photoionization mass spectrometry are explored.
Laser treatment of pediatric vascular lesions: Port wine stains and hemangiomas. Stier MF, Glick SA, Hirsch RJ. J Am Acad Dermatol. 2008 Feb;58(2):261-85.
Pediatric vascular lesions can be medically threatening and psychologically
distressing to patients. This article reviews literature on the laser treatment
of two common pediatric vascular lesions, port wine stains and hemangiomas. The
purpose of this report was to distinguish the lesions from one another and to
present the advantages, disadvantages, complications, and limitations of laser
treatment for each lesion type. This review is not a comprehensive inventory but
instead highlights the studies that best show promising results or the
limitations of laser treatment for the lesions. Overall, port wine stain laser
treatment promoted notable clearing with low side effects, whereas hemangioma
laser treatment provided inconsistent benefits and severe side effects
occasionally. Laser treatment of port wine stains is safe and effective, but
laser treatment of hemangiomas remains controversial and is best for lesions
without deeper components.
Surface photochemistry: organic molecules within nanocavities of calixarenes. Vieira Ferreira LF, Ferreira Machado IL. Curr Drug Discov Technol. 2007 Dec;4(4):229-45.
In order to gain more information regarding photochemical processes in
heterogeneous environments (opaque or powdered samples) laser induced time
resolved luminescence and diffuse reflectance transient absorption spectroscopies
were used for the study of benzophenone (and other neutral organic molecules) as
guests and p-tert-butylcalix[n]arenes with n = 4, 6 and 8 (H(n)CLX[n]) and
partially or totally O-propylated p-tert-butylcalixarenes (H(n)Pr(m)CLX, n
= 2, 1 and 0; m = 2, 3 and 4, respectively) were used as hosts. One of the main
conclusions was that the solid support can deeply affect or even control the
photochemistry of an adsorbed probe. A simple new methodology for lifetime
distribution analysis of the decay of the probes included into calixarenes and
other nanocavities was applied with success for decay data obtained with the use
of intensified charge couple devices, i.e. intensified charge couple devices,
ICCDs. Diffuse reflectance laser flash photolysis and gas chromatography - mass
spectrometry techniques also provided complementary information, the former about
transient species and the latter regarding the final products formed after light
Peripheral atherectomy: a critical review. Bunting TA, Garcia LA. J Interv Cardiol. 2007 Dec;20(6):417-24.
Atherectomy is experiencing increased interest from endovascular specialists as a
therapeutic treatment in the peripheral arteries. Long studied in the coronary
vasculature, atherectomy has several theoretical advantages that make it uniquely
suited for the peripheral circulation. In particular, infra-inguinal peripheral
arterial disease experiences physiologic stresses and forces that have made
traditional percutaneous coronary treatments such as angioplasty and stenting not
as successful. Restenosis has been a major problem for angioplasty and stenting
alone. The SilverHawk atherectomy device has favorable short-term data but
important longer-term data are limited and need further study. Laser atherectomy
also has favorable applications in niche patients but the number of studies is
limited. Unfortunately, athero-ablative technologies for peripheral arterial
disease require more definitive objective data regarding 12-month and longer-term
outcomes in order to obtain widespread scientific acceptance.
Acne vulgaris: lasers, light sources and photodynamic therapy--an update 2007. Gold MH. Expert Rev Anti Infect Ther. 2007 Dec;5(6):1059-69.
Inflammatory acne vulgaris remains one of the most common dermatologic disorders
seen in clinical practice. Medical therapy remains the gold standard for therapy
but recent advances have shown that a variety of lasers and light sources may be
useful in the treatment of inflammatory acne vulgaris. In addition, the use of
20% 5-aminolevulinic acid has found a useful niche in the treatment of
moderate-to-severe inflammatory acne vulgaris.
Fractionated delivery systems for difficult to treat clinical applications: acne scarring, melasma, atrophic scarring, striae distensae, and deep rhytides. Taub AF. J Drugs Dermatol. 2007 Nov;6(11):1120-8.
Fractional resurfacing or laser therapy (FLT) represents a technology that seeks
to address the limitations of both ablative resurfacing and nonablative
treatments. Many companies now offer versions of fractionated erbium or carbon
dioxide lasers. The purpose of this paper is to examine FLT for difficult to
treat applications such as melasma, acne scarring, atrophic scarring, striae
distensae, and deep rhytides. Fractional laser therapy is a truly novel approach
to many conditions, especially those with dermal pathology. Although published
peer review data is limited, the ability to effectively and safely treat these
conditions in all skin types appears to have been significantly enhanced with
this new modality. We are early in our scientific explorations of what is
possible with FLT.
Plasma skin regeneration technology. Bogle MA, Arndt KA, Dover JS. J Drugs Dermatol. 2007 Nov;6(11):1110-2.
Plasma skin regeneration is a novel type of skin rejuvenation technology
developed over the last 3 years. Plasma is the fourth state of matter in which
electrons are stripped from atoms to form an ionized gas. Although high
temperature plasmas have been used in surgery for over a decade, plasma had
previously been used as a conduction medium for electric current. Unlike lasers
which rely on the principle of selective photothermolysis to deliver heat to
specific targets in the skin, plasma technology delivers heat energy directly to
tissue upon contact without reliance on skin chromophores. The plasma itself
produces controlled thermal damage to the skin surface to elicit changes such as
new collagen formation and improvement in photodamaged skin. The technology can
be used at varying energies for different depths of effect, from superficial
epidermal effects to deeper dermal heating.
Juvéderm: a hyaluronic acid dermal filler. Monheit GD, Prather CL. J Drugs Dermatol. 2007 Nov;6(11):1091-5.
Over the past decade, the use of nonsurgical products and devices to correct
facial contour defects and signs of skin aging has exploded with new lasers,
toxins for muscle relaxation, and dermal fillers revolutionizing aesthetic
medicine. Of all the nonsurgical modalities employed during this period, the
dermal filler industry has seen the most growth in demand. In 2006, the worldwide
market for dermal fillers increased by 19%; and the US market is expected to
increase a further 20% to 25%. This is due in large part to new products,
particularly the hyaluronic acids such as Juvéderm, which now promise greater
longevity, fewer side effects, a more natural appearance, and easier
Attosecond electron dynamics. Kling MF, Vrakking MJ. Annu Rev Phys Chem. 2008;59:463-92.
We describe the recent emergence of attosecond science, assessing the present
state of the art and discussing several recent examples where attosecond electron
dynamics has been studied in atomic and molecular systems. After introducing the
generation and characterization of attosecond laser pulses, we describe the use
of isolated attosecond pulses in a pump-probe experiment revealing the subcycle
time dependence of a multiphoton ionization process and an experiment using the
interference from a train of attosecond pulses to extract amplitude and phase
information for electronic wave functions. We furthermore discuss experiments
where ultrashort laser pulses with a reproducible waveform control electron
dynamics in the D(2)(+) molecular ion on attosecond timescales. Attosecond
science is coming of age and presently is reaching a level of maturity and
sophistication that allows detailed investigations of the role of multielectron
dynamics in physics and chemistry.
Clinical applications of molecular haematology: flow cytometry in leukaemias and myelodysplastic syndromes. Dalal BI. J Assoc Physicians India. 2007 Aug;55:571-3.
Flow cytometry is semi-automated study of antigen profile of cells using the
Scatchard principle of antigen-antibody binding and fluorochrome-based detection
systems. Flow cytometric evaluation of cellular proteomics has become an integral
part of the laboratory diagnosis and classification of haematopoietic neoplasms.
Recent technical advances in lasers, monoclonal antibodies, fluorochromes, and
computer-based color compensation algorithms have expanded the usefulness of flow
cytometry. Detection of minimal residual disease by flow cytometry in leukaemias
and lymphomas is incorporated in many treatment protocols. Finding of aberrant
maturation pattern of granulocytes offers a sensitive screening tool for early
diagnosis of myelodysplastic syndromes. Detailed proteomic analysis of leukemias
is helping more precise prognostic and biological stratification.
A different look: 3-dimensional facial imaging of a child with Binder syndrome. Kau CH, Hunter LM, Hingston EJ. Am J Orthod Dentofacial Orthop. 2007 Nov;132(5):704-9.
Binder syndrome, or maxillonasal dysplasia, is an uncommon developmental anomaly
characterized by an unusually flat, underdeveloped midface, with an abnormally
short nose and a flat nasal bridge. In this article, we review the literature and
describe how 3-dimensional laser scanning was used to evaluate the facial
morphology of a 12-year-old boy with this syndrome.
Office-based laryngeal laser surgery with the 532-nm pulsed-potassium-titanyl-phosphate laser. Zeitels SM, Burns JA. Curr Opin Otolaryngol Head Neck Surg. 2007 Dec;15(6):394-400.
PURPOSE OF REVIEW: Office-based laryngeal laser surgery is a recent innovation.
It is emerging as a reliable and practical method of treating a number of
laryngeal lesions, which is increasingly popular in the US and abroad. The 532-nm
pulsed-potassium-titanyl-phosphate laser has become our laser of choice in
treating vocal-fold lesions and diseases for a number of transparent and
practical reasons. RECENT FINDINGS: Fiber-based lasers and distal-chip flexible
endoscopy have facilitated a new style of surgery. Epithelial diseases such as
dysplasia and papillomatosis are well suited for this treatment. Although the
initial angiolytic laser used in the larynx was a 585-nm pulsed-dye laser, the
solid-state 532-nm pulsed-potassium-titanyl-phosphate laser has been demonstrated
to be more effective clinically, more reliable structurally and less expensive.
SUMMARY: Technologies to enhance laryngoscopic imaging and lasers, along with
socioeconomic forces, should lead to increasing numbers of laryngeal procedures
being done in the office with local anesthesia. The 532-nm
pulsed-potassium-titanyl-phosphate laser has emerged thus far as the optimal
technology for treating phonatory mucosa although further development is likely.
In-office laryngeal surgery with the 585-nm pulsed dye laser. Franco RA Jr. Curr Opin Otolaryngol Head Neck Surg. 2007 Dec;15(6):387-93.
PURPOSE OF REVIEW: To describe the current support in the literature for
in-office surgery using the 585-nm pulsed dye laser. RECENT FINDINGS: There are
substantial cost savings (US$5000) and patient comfort when in-office surgery is
performed with the pulsed dye laser. The pulsed dye laser can be used in the
office and operating room to activate aminolevulinic acid for photodynamic
treatment of recalcitrant laryngeal keratosis, with long-term eradication of
keratosis without the prolonged photosensitivity of previous photodynamic agents.
The site of the cleavage plane created in the true vocal fold mucosa has now been
elucidated. SUMMARY: The 585-nm pulsed dye laser allows safe, medically effective
and cost-effective in-office surgery for a host of laryngeal lesions such as
papillomatosis, keratosis, Reinke's edema, granulomas and other vascular lesions.
The pulsed dye laser can activate aminolevulinic acid for laryngeal photodynamic
therapy. Of the lasers currently in use it has the longest track record of safety
and, to the satisfaction of many, continues in service at 23 centers around the
Examination of fly motion vision by functional fluorescence techniques. Kurtz R, Kalb J, Spalthoff C. Front Biosci. 2008 Jan 1;13:3009-21.
Over the past years, classical electrophysiological approaches to elucidate the
functioning of nerve cells have been complemented by functional optical methods,
in particular fluorescence imaging. This review illustrates how optical methods
have proved helpful in the analysis of the neuronal principles underlying visual
motion processing in the fly, a model system which allows physiological
investigation under in vivo conditions. Many aspects of dendritic processing in
large-field motion-sensitive neurons of Calliphora have been investigated by Ca2+
imaging. In addition, the function of Ca2+ can be addressed directly by
manipulating its concentration via UV photolysis of caged Ca2+. The extraction of
specific motion information from visual stimuli depends on interactions between
individual neurons. A powerful technique to dissect the motion-vision circuit is
the photoablation of single neurons. By selective photoablation the role of
individual neurons within synaptic networks has been clarified. Further advances
in the disclosure of visual motion processing may in the future be achieved by
imaging the activity of single neurons during the processing of natural inputs.
Moreover, the combination of genetic tools with functional fluorescence
approaches will help elucidate the role of classes of neurons in the visual
motion pathway of the blowfly's smaller companion, the fruitfly Drosophila.
What's new with hyaluronic acid fillers. Gold MH. J Drugs Dermatol. 2007 Oct;6(10):1050-3.
Aesthetic Practice Trends is a periodic feature that will give readers updates on
topics involving everyday clinical practice issues from how to run a successful
dermatology practice to marketing and advertising ideas, and trends. It will also
provide additional coverage on lasers, light sources, and other energy-based
devices as well as fillers, toxins, and the latest in skin care needs for your
patients. Each column will have a central topic relevant to aesthetic dermatology
and ideas to help improve your daily practice.
Basics of laser application to dermatology. Watanabe S. Arch Dermatol Res. 2008 Apr;300 Suppl 1:S21-30.
Q-switched lasers, with a pulse of light sufficiently short (nanosecond-domain)
is demonstrated to be useful for treatment of dermal melanocytosis, blue-black
tattoos, melanocytic nevi, and solar lentigines, although transient
postinflammatory hyperpigmentation usually developed in the irradiated area
during the following 3-4 months. If the postinflammatory pigmentation does not
disappear after 1 year, incontinentia pigmenti histologica is a possibility.
However, the pigment in café-au-lait macules responds variably to treatment.
Melasma shows no response to laser. Therefore, accurate diagnosis is the key to
success in the laser treatment. Laser treatment of vascular lesions is based on
selective absorption by blood with thermal injury to the vessel wall. Therefore,
the pulse-width of the vascular-specific lasers must be longer
(microsecond-domain) than that of pigment-specific lasers. Because the wavelength
of the lasers for vascular lesions, however, cannot penetrate into the deep areas
of the skin, not all vascular lesions can be treated. Laser or light-assisted
hair removal offers an efficient way to permanently reduce excessive hair growth.
Skin rejuvenation is possible by laser or pulsed light with millisecond-domain
pulse-width. Because these light sources, however, cause severe damage to the
skin surface, the exposure energy must be reduced and the treatment must be
combined with cooling devices. Therefore, the clinical results of light-assisted
skin rejuvenation are not prominent. In conclusion, the pulse-width and
wavelength of the laser light are critical parameters for laser treatments. If we
obtain information about these parameters for specific lasers, we can expect the
results of the treatment to be positive.
Future directions in lamellar corneal transplantation. Tan DT, Mehta JS. Cornea. 2007 Oct;26(9 Suppl 1):S21-8.
The concept of lamellar keratoplasty (LK) is that of targeted lamellar
replacement of corneal tissue while retaining normal cornea. It involves
replacing either anterior stroma [anterior lamellar keratoplasty (ALK)] or
posterior replacement of deep stromal and endothelial layers [posterior lamellar
keratoplasty (PLK) or endothelial keratoplasty]. Despite the distinct advantages
of ALK surgery, penetrating keratoplasty (PK) remains the most common
procedure-largely because lamellar surgery is more technically demanding and time
consuming, and interface irregularity arising from manual lamellar dissection
often results in suboptimal visual outcomes. Recent improvements of surgical
technique and advances in instrumentation such as microkeratome-assisted lamellar
transplantation have contributed to improved visual quality with LK surgery.
Long-term graft survival rates and endothelial cell counts after PK continue to
drop for many years after surgery, clearly showing the disadvantage of
unnecessary replacement of healthy endothelium in anterior-stromal disorders. The
aim of this review is to evaluate the shifting emphasis from penetrating to
lamellar forms of corneal transplantation and to highlight some future directions
in lamellar surgery including new techniques in both ALK and PLK and the use of
microkeratomes and femtosecond lasers to enhance outcomes.
Laser tweezer deformation of giant unilamellar vesicles. Poole C, Losert W. Methods Mol Biol. 2007;400:389-404.
Two methods are presented for deforming giant unilamellar vesicles with
holographic optical tweezers. The first allows ultrahigh spatial- and
temporal-resolution optical tracking of membrane deformations, by using embedded
silica microspheres in a giant unilamellar vesicle as tracers. The vesicles are
stretched by moving several beads with multiple optical tweezers and then are
released from an elongated shape. Time constants of relaxation can be extracted
by tracking the beads with 0.5-ms time resolution and 10 nm or better spatial
resolution. The second method allows for direct deformation of the membrane into
complex shapes using two solutions with different indices of refraction and
holographic optical tweezer. Vesicle shapes are extracted directly with an active
contour algorithm. Fourier analysis of the relaxation of the vesicle shape back
to an equilibrium shape demonstrates a possible application of this technique.
Optical coherence tomography using rapidly swept lasers. Yun SH. Conf Proc IEEE Eng Med Biol Soc. 2006;1:125-8.
Optical coherence tomography (OCT) has proven to be a useful diagnostic tool in
several medical areas. An emerging second-generation OCT technology, termed
optical frequency domain imaging, is expected to increase the clinical
applications of OCT significantly.
Laser capture sampling and analytical issues in proteomics. Gutstein HB, Morris JS. Expert Rev Proteomics. 2007 Oct;4(5):627-37.
Proteomics holds the promise of evaluating global changes in protein expression
and post-translational modification in response to environmental stimuli.
However, difficulties in achieving cellular anatomic resolution and extracting
specific types of proteins from cells have limited the efficacy of these
techniques. Laser capture microdissection has provided a solution to the problem
of anatomical resolution in tissues. New extraction methodologies have expanded
the range of proteins identified in subsequent analyses. This review will examine
the application of laser capture microdissection to proteomic tissue sampling,
and subsequent extraction of these samples for differential expression analysis.
Statistical and other quantitative issues important for the analysis of the
highly complex datasets generated are also reviewed.
The use of naphthalene-2,3-dicarboxaldehyde for the analysis of primary amines using high-performance liquid chromatography and capillary electrophoresis. Rammouz G, Lacroix M, Garrigues JC, Poinsot V, Couderc F. Biomed Chromatogr. 2007 Dec;21(12):1223-39.
This paper reviews analytical methods, instrumental developments and applications
for derivatization of primary amines with naphthalene-2,3-dicarboxaldehyde using
fluorescence and chemiluminescence detection with capillary electrophoresis (CE)
and high performance liquid chromatography (HPLC). The use of lasers as well as
lamps as the excitation source for fluorescence detection is discussed. The
detection limit observed with naphthalene-2,3-dicarboxaldehyde derivatization is
often lower and better than those obtained with other analytical separations and
other fluorescent dyes. In addition, this paper describes the crucial points that
influence the stability of NDA primary amine derivatives, and summarize the
separation, derivatization and migration conditions of the different techniques,
with their advantages and drawbacks.
Optical amplification from single excitons in colloidal quantum dots. Doose S. Small. 2007 Nov;3(11):1856-8.
Targeted UV therapy in the treatment of psoriasis. Stein KR, Pearce DJ, Feldman SR. J Dermatolog Treat. 2008;19(3):141-5.
Ultraviolet (UV) light is an effective treatment for extensive psoriasis and some
other inflammatory skin conditions. Because the predominant effect of UV is a
local one (as opposed to a systemic effect on immunity), localized delivery of
ultraviolet B radiation (UVB) may be a useful treatment for localized variants of
psoriasis and other conditions. The article reviews the literature regarding use
of localized UV therapy. A theoretical benefit of localized UV therapy is reduced
toxicity compared with whole-body therapy. Practical benefits in psoriasis
treatment include higher efficacy and more appealing cosmesis compared with
topicals. The 308-nm excimer laser is effective for psoriasis with fewer UVB
treatments and lower total UVB exposure than needed for total body UV treatment.
Other methods of localized UV delivery include quartz lamps, hand-held home UV
devices, and non-laser intense photo sources. Other conditions treated with
localized UV include vitiligo and lichen planus. Localized UV therapy is a useful
modality for the treatment of localized variants of psoriasis with growing use
for other dermatologic diseases.
Tattoo removal--state of the art. [Article in English, German] Pfirrmann G, Karsai S, Roos S, Hammes S, Raulin C. J Dtsch Dermatol Ges. 2007 Oct;5(10):889-97.
Tattooing has been around since the early beginnings of modern civilization. The
discovery of selective photothermolysis at last has made it possible to remove
tattoos without leaving a scar. Q-switched neodymium: yttrium-aluminum-garnet,
alexandrite, and ruby lasers with pulse durations in the nanosecond domain
fulfill this need. Argon or cw-CO(2) lasers as well as intense pulsed light
sources should not be used since they often produce significant scarring. This
article provides an overview of current laser systems. Developments leading to
new tattoo inks, feedback systems to detect the absorbance characteristics of
tattoo inks, dermal clearing agents, and perhaps even lasers with shorter
pulse-durations might improve the results in the future.
Argon laser: a light source alternative for photopolymerization and in-office tooth bleaching. Cassoni A, Rodrigues JA. Gen Dent. 2007 Sep-Oct;55(5):416-9.
The argon laser is an alternative light source that can be used for the
photopolymerization of resin-based dental materials and for tooth bleaching. The
argon laser emits specific laser lines with wavelengths that correspond to the
absorption peak of camphoroquinone, the initiator of polymerization for the
adequate photocuring of resin composite. The collimated beam of the argon laser
does not decrease with distance and an optical fiber has access to all cavity
areas. In addition, the temperatures produced by an argon laser when curing
resin-based materials and performing in-office tooth bleaching are significantly
lower than those of conventional photocuring units. Argon is one of the three
dental laser wavelengths that have been cleared by the FDA for tooth whitening.
This article reviews the literature to examine the role that argon lasers can
play in dental treatment.
Separation-based glycoprofiling approaches using fluorescent labels. Domann PJ, Pardos-Pardos AC, Fernandes DL, Spencer DI, Radcliffe CM, Royle L, Dwek RA, Rudd PM. Proteomics. 2007 Sep;7 Suppl 1:70-6.
Glycoprotein analysis is essential within the biopharmaceutical industry, as the
structure of the different glycans present can affect the safety and efficacy of
products. However analysis of cleaved glycans presents a major analytical
challenge, due to their inherent complexity, lack of chromophore and the
existence of various isoforms (both position and linkage). In addition, almost
all glycoproteins consist of a heterogeneous collection of differently
glycosylated variants, so the released glycan pool contains a range of
structures. Both normal phase chromatography and capillary gel electrophoresis
offer excellent selectivity for the analysis of fluorescently labelled glycans.
The normal phase (NP) chromatographic approach is sensitive, reliable and well
established, with databases available for searching structures assigned relative
to retention times. Capillary gel electrophoresis with laser induced fluorescence
(CGE-LIF) offers faster analysis times, though currently no databases are
available to search mobilities against structures, therefore data has to be
cross-correlated with either normal phase chromatography or mass spectrometry
approaches when developing and validating methods. The principles of both methods
are described and a review is presented that includes evaluation against a set of
criteria established through consultation with the biopharmaceutical industry.
Laser capture microdissection technology. Espina V, Heiby M, Pierobon M, Liotta LA. Expert Rev Mol Diagn. 2007 Sep;7(5):647-57.
Deciphering the cellular and molecular interactions that drive disease within the
tissue microenvironment holds promise for discovering drug targets of the future.
In order to recapitulate the in vivo interactions through molecular analysis, one
must be able to analyze specific cell populations within the context of their
heterogeneous tissue microecology. Laser capture microdissection is a method to
procure subpopulations of tissue cells under direct microscopic visualization.
Laser capture microdissection technology can harvest the cells of interest
directly or can isolate specific cells by cutting away unwanted cells to give
histologically pure enriched cell populations. A variety of downstream
applications exist: DNA genotyping and loss-of-heterozygosity analysis, RNA
transcript profiling, cDNA library generation, mass spectrometry proteomics
discovery and signal pathway profiling.
Shedding some light on laser pointer eye injuries. Ajudua S, Mello MJ. Pediatr Emerg Care. 2007 Sep;23(9):669-72.
OBJECTIVES: Laser use has become common in the home and workplace. We present a
review of laser eye injuries and guidance for the emergency medicine physician on
evaluation of laser eye injury-related complaints. METHODS: A review of the
literature on the potential for injury, concerning signs and symptoms,
evaluation, and referral recommendations is discussed. RESULTS: The scientific
literature finds that laser eye injuries are uncommon from use of nonindustrial
lasers. Furthermore, an eye injury from a regulated Class 2 or Class 3A by a
transient sweep across the line of vision does not result in injury, but injury
can occur with a direct intentional prolonged exposure. CONCLUSIONS: Patient's
history of the length and type of laser exposure is important. A significant
direct eye exposure to a laser, persistent after images, and decreased visual
acuity should initiate urgent referral to an ophthalmologist for further
ophthalmologic testing. Brief laser exposure or indirect exposures with
complaints of headaches or blurry vision require other diagnostic explanations.
Recent advances in fluorescence cross-correlation spectroscopy. Hwang LC, Wohland T. Cell Biochem Biophys. 2007;49(1):1-13.
Fluorescence cross-correlation spectroscopy (FCCS) is a method that measures the
temporal fluorescence fluctuations coming from two differently labeled molecules
diffusing through a small sample volume. Cross-correlation analysis of the
fluorescence signals from separate detection channels extracts information of the
dynamics of the dual-labeled molecules. FCCS has become an essential tool for the
characterization of diffusion coefficients, binding constants, kinetic rates of
binding, and determining molecular interactions in solutions and cells. By
cross-correlating between two focal spots, flow properties could also be
measured. Recent developments in FCCS have been targeted at using different
experimental schemes to improve on the sensitivity and address their limitations
such as cross-talk and alignment issues. This review presents an overview of the
different excitation and detection methodologies used in FCCS and their
biological applications. This is followed by a description of the fluorescent
probes currently available for the different methods. This will introduce
biological readers to FCCS and its related techniques and provide a starting
point to selecting which experimental scheme is suitable for their type of
Nonablative tissue remodeling and photorejuvenation. DeHoratius DM, Dover JS. Clin Dermatol. 2007 Sep-Oct;25(5):474-9.
Nonablative facial resurfacing is a noninvasive approach to tissue remodeling and
skin rejuvenation. These procedures are considered an alternative to the more
traditional laser resurfacing with less dramatic effects, but also with
significantly less downtime. Results vary based on the lasers and light sources
used. In general, the infrared lasers improve texture, visible light lasers
somewhat improve texture but greatly reduce redness and telangiectasias, and
intense pulsed light devices improve both red targets and brown discoloration, as
well as skin texture. Lastly, low-energy devices may improve redness and texture
modestly. Patient selection, as well as device selection, is based on the outcome
desired. Side effects are uncommon and preventable.
Ablative laser resurfacing: high-energy pulsed carbon dioxide and erbium:yttrium-aluminum-garnet. Riggs K, Keller M, Humphreys TR. Clin Dermatol. 2007 Sep-Oct;25(5):462-73.
The development of the short-pulsed high-energy carbon dioxide laser in the mid
1990's led to the emergence of laser skin resurfacing. Used in the continuous
mode, the CO(2) laser can cut and coagulate simultaneously. Used in the pulsed
mode, the CO(2) laser is a powerful tool for epidermal ablation in many different
contexts both therapeutic and cosmetic. Both the CO(2) and Erbium YAG lasers emit
light in the infrared spectrum. Energy is preferentially absorbed by
intracellular water creating rapid heating and vaporization of tissue. Because of
the wavelength of the Er:YAG laser (2940 nm) more closely approximates the
absorption peak of water (3000 nm) the target chromophore than the CO(2) laser
(10,600 nm) nearly all of the energy is absorbed in the epidermis and papillary
dermis yielding superficial ablation and less underlying thermal damage. The
advantages, disadvantages, and applications of each type of laser resurfacing
will be discussed. Despite proven efficacy, the public acceptance of laser
resurfacing has declined with the emergence of new laser systems that cause
dermal remodeling without ablating the overlying epidermis dramatically reducing
recovery time. In the absence of blinded comparison studies, it remains unclear
whether the clinical results of the newer 'nonablative' laser systems compare
with their ablative predecessors.
Laser therapy for leg veins. Kunishige JH, Goldberg LH, Friedman PM. Clin Dermatol. 2007 Sep-Oct;25(5):454-61.
Visible veins on the leg are a common cosmetic concern affecting approximately
80% of women in the United States (Engel A, Johnson MI, Haynes SG. Health effects
of sunlight exposure in the United States: results from the first national health
and nutrition examination survey, 1971-1974. Arch Dermatol 1988;124:72-9).
Without a quick and noninvasive treatment available, leg veins present a
therapeutic challenge. This challenge has been tackled by the design of lasers
with longer pulse durations, and the use of lasers with longer wavelengths and
cooling devices. Recent studies show the efficacy of laser treatment beginning to
approach that of sclerotherapy, the gold standard. This review outlines the
principles guiding laser treatment, the current available options, and a
clinically oriented approach to treating leg veins.
Lasers and light sources for the removal of unwanted hair. Gold MH. Clin Dermatol. 2007 Sep-Oct;25(5):443-53.
The long-term removal of unwanted hair has become one of the most common and
popular cosmetic laser treatments being performed around the world. This
manuscript will review a variety of lasers and light sources that have been and
are currently being used for epilation of the skin. All of the lasers and light
systems currently available do work for long-term hair removal; it is the
responsibility of the treating clinician to understand the varying technologies
and what the limits of each device is and, most importantly, to be able to handle
any untoward effects that might arise during the coarse of treatment. Then, hair
removal can be successful for both the patient and the physician using their
particular medical device.
Masers to magic bullets: an updated history of lasers in dermatology. Houk LD, Humphreys T. Clin Dermatol. 2007 Sep-Oct;25(5):434-42.
Laser therapy is one of the fastest expanding and most exciting fields in
dermatology. From its theoretical beginnings in Einstein's imagination, lasers
have come to be used in treatments for conditions ranging from skin malignancy
and acne to hirsutism and photoaging. We will briefly review the evolution of
laser treatment, with a focus on the recent developments surrounding the new
[Diagnostic techniques in breast cancer detection. Part I: imaging methods and their modifications] [Article in Polish] Slubowski T, Slubowska M, Wojciechowski A. Ginekol Pol. 2007 May;78(5):388-92.
This publication contains an overview of the imaging techniques and the related
technologies utilized in breast cancer diagnosis. It describes both those known
for tens of years as well as the ones developed recently thanks to the new
technological developments. An integration and coexistence of the diagnostic
methods from classical mammography to the computerized laser mammography has
become essential in order to cope with the requirements of early detection of
breast tumours, which is a precondition of successful treatment and longer
survival periods upon which patients rely.
Nurse-administered laser in dermatology. Jones H. Nurs Clin North Am. 2007 Sep;42(3):393-406, vi.
Nurses have become an essential part of patient care in laser therapy. In
dermatology, the potential for helping patients achieve excellent results for
individual skin needs is exponential when combined with appropriate technology,
evidence-based care, and a competent, conscientious nurse. This article explains
how a laser functions, outlines the use of lasers in treating particular
dermatologic conditions, provides guidelines for posttreatment care, and
discusses the nurse's role in providing laser treatment.
Oral mucosal disease: Lichen planus. Scully C, Carrozzo M. Br J Oral Maxillofac Surg. 2008 Jan;46(1):15-21. Epub 2007 Sep 5.
Lichen planus (LP) is a common disorder in which auto-cytotoxic T lymphocytes
trigger apoptosis of epithelial cells leading to chronic inflammation. Oral LP
(OLP) can be a source of severe morbidity and has a small potential to be
malignant. The diagnosis of OLP can be made from the clinical features if they
are sufficiently characteristic, particularly if typical skin or other lesions
are present, but biopsy is recommended to confirm the diagnosis and to exclude
dysplasia and malignancy. OLP is treated with anti-inflammatory agents, mainly
the topical corticosteroids, but newer agents and techniques are becoming
Meta-analysis of holmium laser enucleation versus transurethral resection of the prostate for symptomatic prostatic obstruction. Tan A, Liao C, Mo Z, Cao Y. Br J Surg. 2007 Oct;94(10):1201-8.
BACKGROUND: Holmium laser enucleation (HoLEP) is an alternative to transurethral
resection (TURP) of the prostate for symptomatic prostatic obstruction. METHODS:
Randomized controlled trials comparing HoLEP and TURP were identified
systematically using Medline, Embase and The Cochrane Library. Primary outcomes
were peak urinary flow rate (Qmax), postvoid residual volume, symptom score and
quality of life. Secondary outcomes were duration of operation, hospital stay,
blood loss, catheterization time and adverse events. RESULTS: There was no
statistically significant difference between HoLEP and TURP in terms of Qmax at 6
and 12 months' follow-up. HoLEP was associated with significantly less blood
loss, a shorter catheterization time and a shorter hospital stay. TURP was
associated with reduced operating time. The techniques were similar in terms of
urethral stricture, stress incontinence, transfusion requirement and rate of
reintervention. CONCLUSION: HoLEP and TURP provide a similar improvement in Qmax.
HoLEP, however, has several advantages over TURP, despite requiring more
operating time. It is at least as safe as TURP in terms of adverse events.
Copyright (c) 2007 British Journal of Surgery Society Ltd.
[Lasers in plastic surgery--vascular lasers] [Article in Polish] Siewiera IP, Wysocki MS, Latkowski IT. Wiad Lek. 2007;60(3-4):178-84.
Laser treatment of the cutaneous vascular lesions gained approbation and
well-established position among plastic surgery techniques. Rapidly evolving
laser market delivers us modem and safer devices. In the paper we discuss the
most common vascular lesions and available lasers used to treat them. Described
indications and safety rules might be useful for many specialists for their
patient therapy choice.
Photodynamic treatment of oral lesions. Kvaal SI, Warloe T. J Environ Pathol Toxicol Oncol. 2007;26(2):127-33.
Photodynamic treatment (PDT) was first started in the oral cavity in the mid
1980s. Hematoporphyrins were rapidly replaced by Photofrin and
meta-tetrahydroxyphenylchlorin (mTHPC) as photosensitisers of choice, and over
the years these two have been approved by several health authorities for PDT.
5-aminolevulinic acid (ALA) and some dyes (e.g., toluidine and methyene blue)
have also been tested. Several different nonthermal lasers have been used and
lately light-emitting diodes (LEDs) have been tried. Most of the clinical
treatments have been carried out on oral squamous cell carcinoma (OSSC), either
primary or metastatic lesions, with good results. The treatment leaves little
scarring and can be used before, in conjunction with, and adjunctive to other
treatment modalities. The greatest disadvantage is that the patients are
photosensitive for several weeks following systemic administration of the
photosensitiser. PDT is now an accepted palliative treatment. Systemic
administration of ALA has been more successful than local application in the
treatment of precancerous lesions such as oral leukoplakia. PDT following topical
application of photosensitiser (metylene blue and methyl-ALA) has shown
improvement in cutaneous diseases of the oral mucous membrane such as oral lichen
planus. The bactericidal effect of PDT has also been tested on oral plaque, but
little clinical work has been performed so far. Instead of mechanical cleaning or
antibiotic therapy, PDT may also play a role in dental diseases.
New trends in telescopic remote Raman spectroscopic instrumentation. Sharma SK. Spectrochim Acta A Mol Biomol Spectrosc. 2007 Dec 15;68(4):1008-22. Epub 2007 Aug 2.
Raman spectroscopy is a powerful analytical technique in many areas of research
for several reasons. These include the sensitivity to small structural changes,
non-invasive sampling capability, minimal sample preparation, narrow line widths
of Raman lines, and high spatial resolution in the case of micro-Raman
spectroscopy. Advancements in lasers, spectrographs and holographic optical
components have made Raman spectroscopy an effective tool for analyzing natural
and synthetic materials. These advances have led to the development of both in
situ Raman spectroscopy and telescopic remote Raman spectroscopy for a lander or
rover for planetary exploration. A telescopic Raman spectroscopic system capable
of measuring Raman spectra of minerals, inorganic and organic chemicals, and
biogenic materials to radial distances in the range 10-100 m has been developed.
In this work, the author reviews the current status of telescopic remote Raman
spectroscopic instrumentation and examines new trends in the field of remote
Raman spectroscopy and its combination with time-resolved remote laser-induced
native fluorescence (LINF) and laser-induced breakdown spectroscopy (LIBS), and
their applications in earth and planetary science.
Established treatments of skin hypermelanoses. Nikolaou V, Stratigos AJ, Katsambas AD. J Cosmet Dermatol. 2006 Dec;5(4):303-8.
Cutaneous hypermelanoses are frequently encountered conditions that can have
severe adverse psychosocial and emotional effects on affected patients. Melasma,
postinflammatory hyperpigmentation, drug-induced pigmentation, and erythema
dischromicum perstans are among the most common cutaneous disorders leading to
acquired skin hyperpigmentation. The treatment of these disorders is often
challenging and requires a great deal of patience from the patient and a wealth
of experience and knowledge from the dermatologist. Current treatments include
depigmenting agents, chemical peels, and lasers. The ideal bleaching agent has to
fulfill certain pharmacologic criteria. It should have a potent bleaching effect
with a rapid time of onset, carry no side effects, and lead to a permanent
removal of undesired pigment. We review the established treatment approaches of
cutaneous hyperpigmentation based on literature review and our personal
Paradoxical effects of hair removal systems: a review. Lolis MS, Marmur ES. J Cosmet Dermatol. 2006 Dec;5(4):274-6.
Although a variety of lasers have proven to be clinically effective for long-term
hair removal, the use of these lasers has also been associated with undesirable
side effects, such as hyper- and hypopigmentation, crusting, erythema, and edema.
One notable side effect that seems to be underreported in the literature is the
growth of fine dark hair in untreated areas close to the treated ones. This
contradictory hypertrichosis is known as the paradoxical effect. In this paper,
we review the published reports of the paradoxical effect and offer some possible
explanations for this effect. The paradoxical effect has been documented most
commonly after the use of induced pulse light and alexandrite lasers. One
possible explanation is the activation of dormant hair follicles by suboptimal
fluences. Another mechanism may be the synchronization of hair growth cycles by
direct light stimulation.
Laser diffractometry and cascade impaction for nebulizer product characterization. Mitchell JP, Tservistas M. Pharmeur Sci Notes. 2006 Dec;2006(2):49-52.
The techniques of laser diffractometry and multi-stage cascade impaction are
widely used in the in vitro characterization of liquid droplet aerosols generated
from nebulizing systems. This position paper is a concise summary of key aspects
relating to both techniques and is intended to inform the development of the
proposed general chapter 2.9.44 "Preparations for Nebulization" for the European
Pharmacopeia, as well as assist in the development of a proposed International
Standard (ISO 27427) for nebulizing systems.
Plasmonic photothermal therapy (PPTT) using gold nanoparticles. Huang X, Jain PK, El-Sayed IH, El-Sayed MA. Lasers Med Sci. 2008 Jul;23(3):217-28. Epub 2007 Aug 3.
The use of lasers, over the past few decades, has emerged to be highly promising
for cancer therapy modalities, most commonly the photothermal therapy method,
which employs light absorbing dyes for achieving the photothermal damage of
tumors, and the photodynamic therapy, which employs chemical photosensitizers
that generate singlet oxygen that is capable of tumor destruction. However,
recent advances in the field of nanoscience have seen the emergence of noble
metal nanostructures with unique photophysical properties, well suited for
applications in cancer phototherapy. Noble metal nanoparticles, on account of the
phenomenon of surface plasmon resonance, possess strongly enhanced visible and
near-infrared light absorption, several orders of magnitude more intense compared
to conventional laser phototherapy agents. The use of plasmonic nanoparticles as
highly enhanced photoabsorbing agents has thus introduced a much more selective
and efficient cancer therapy strategy, viz. plasmonic photothermal therapy
(PPTT). The synthetic tunability of the optothermal properties and the
bio-targeting abilities of the plasmonic gold nanostructures make the PPTT method
furthermore promising. In this review, we discuss the development of the PPTT
method with special emphasis on the recent in vitro and in vivo success using
gold nanospheres coupled with visible lasers and gold nanorods and silica-gold
nanoshells coupled with near-infrared lasers.
[Excimer laser trabeculotomy: minimally invasive glaucoma surgery] [Article in German] Herdener S, Pache M. Ophthalmologe. 2007 Aug;104(8):730-2.
Excimer laser trabeculotomy (ELT) is a minimally invasive method for reducing
intraocular pressure. It can be performed as a stand-alone procedure or in
combination with cataract surgery in just a few minutes. Laser spots are applied
in the anterior chamber angle via an endoscopic camera or a gonio lens. In
contrast to argon laser trabeculoplasty, shunts between the anterior chamber and
Schlemm's canal are prepared by a photoablative laser, thus improving the outflow
of aqueous humour. Best results can be expected in patients with moderately
elevated intraocular pressure and cataract undergoing the combined procedure.
Multiphoton microscopy: a new paradigm in dermatological imaging. Lin SJ, Jee SH, Dong CY. Eur J Dermatol. 2007 Sep-Oct;17(5):361-6. Epub 2007 Aug 2.
In recent years, the non-linear optical imaging technique of multiphoton
microscopy has gained significant popularity in biomedical imaging. Since optical
imaging can provide detailed morphological information of biological structures,
multiphoton microscopy holds great promise as a potential clinical diagnostic
tool of dermatological conditions. In this review, we will begin by discussing
the basic principles of multiphoton microscopy, including the process of
fluorescence and second harmonic generation. In addition, we will present the
dermatological applications of multiphoton imaging, including the diagnosis of
basal cell carcinoma and the evaluation of skin photoaging. We also describe
applications of this technique to transcutaneous drug delivery, melanoma imaging,
skin diseases associated with extracellular matrix alterations and cutaneous
microvascular observation. Finally, we will discuss the additional issues that
need to be resolved before multiphoton imaging can become a major diagnostic tool
in clinical dermatology.
How to make big molecules fly out of liquid water: applications, features and physics of laser assisted liquid phase dispersion mass spectrometry. Charvat A, Abel B. Phys Chem Chem Phys. 2007 Jul 14;9(26):3335-60. Epub 2007 Mar 27.
Applications, features, and mechanistic details of laser assisted liquid phase
dispersion mass spectrometry are highlighted and discussed. It has been used in
the past to directly isolate charged molecular aggregates from the liquid phase
and to determine their molecular weight employing sensitive time-of-flight mass
spectrometry. The liquid matrix in this MALDI (matrix assisted laser desorption
and ionization) type approach consists of a 10 microm diameter free liquid
filament in vacuum (or a free droplet) which is excited with a focused infrared
laser pulse tuned to match the absorption frequency of the OH-stretch vibration
of bulk water near 2.8 microm. Due to these features we will refer to the
approach as free liquid matrix assisted laser dispersion of ions or ionic
aggregates (IR-FL-MALDI), although also LILBID ("laser induced liquid beam (bead)
desorption and ionization") has been proposed early as a descriptive acronym for
the technique and may be used alternatively. Low-charge-state macromolecular
adducts are isolated in the gas phase from solution via a yet poorly
characterized mechanism which sensitively depends upon the laser intensity and
wavelength, and after the gentle liquid-to-vacuum transfer the aggregates are
analyzed via time-of-flight (TOF) mass spectrometry (MS). Possible mechanisms for
the isolation and charging of biomolecules directly from liquid solution are
discussed in the present contribution. Recent technical advances such as
minimizing the sample consumption, strategies for high throughput mass
spectrometry, and coupling of liquid beam MS with HPLC will be highlighted as
well. An interesting feature of IR-FL-MALDI is what we call the linear response,
i.e., a surprising linearity of the gas phase mass signal on the solution
concentration over many orders of magnitude for a large number of biomolecular
systems as well as ions. Due to these features the approach may be regarded as a
true solution probing spectroscopy, which enables elegant biokinetic studies.
Several experiments in which time resolved IR-FL-MALDI-MS has recently been
employed successfully are given. A particular highlight is the possibility to
quantitatively detect oxidation states in solution, which clearly distinguishes
the present approach from other established MS source concepts. Due to the good
matrix tolerance also proteins in complex mixtures can be monitored
New and experimental treatments of cloasma and other hypermelanoses. Picardo M, Carrera M. Dermatol Clin. 2007 Jul;25(3):353-62, ix.
In clinical practice, acquired hyperpigmentations represent the most common
disorders of pigmentation the dermatologist has to treat. Despite the large
number of depigmenting agents available, the treatment of hyperpigmentations is
often unsuccessful and disappointing and is still a challenge for dermatologists.
This article focuses on the chemical compounds reported to be in depigmenting or
skin lightening agents, their proposed mechanism of action, and their clinical
efficacy in the treatment of melasma and hypermelanoses, mainly based on
randomized clinical trials. It also reviews chemical peels and their indications,
together with the possible uses of laser and intense pulsed light.
Treatment of pulsed dye laser-resistant port wine stain birthmarks. Jasim ZF, Handley JM. J Am Acad Dermatol. 2007 Oct;57(4):677-82. Epub 2007 Jul 19.
The concept of selective photothermolysis with the 577-/585-nm pulsed dye laser
(PDL) revolutionized treatment of relatively common port wine stain (PWS)
birthmarks. The majority of PWS can be significantly lightened with the PDL.
However, few PWS are lightened completely with PDL and up to 20% hardly lighten
at all. PDL-resistant PWS exist in any large cutaneous laser practice and
constitute a difficult management problem. This article discusses the proposed
cause, and currently available and emerging options for PDL-resistant PWS. These
include higher power, longer wavelength, variable pulse width lasers with
selective epidermal cooling such as 595-nm PDL, 755-nm alexandrite, 810-nm diode,
1064-nm neodymium:yttrium-aluminum-garnet, and intense pulse light systems. Other
promising modalities include topical and systemic photodynamic therapy,
electrical optical synergy technology, pulse stacking of similar or differing
wavelengths, use of optical clearing agents in conjunction with laser, and erbium
laser epidermal stripping before laser treatment.
[Current methods of treatment and prevention of pathologic scars] [Article in Hungarian] Kelemen O, Kollár L. Magy Seb. 2007 Apr;60(2):63-70.
The aetiology of pathologic scarring is unknown today regarding the keloids. The
authors have analyzed the literature and own experience retrospectively according
to the evidence based treatments and prevention of the hypertrophic and keloid
scars. The corticosteroids have been used intralesionally since the beginning of
the 1960-ies. It was followed by the pressure garment therapy in order to treat
the widespread burns scars in the early 1970-ies. The silicone gel sheeting is
being used since the 1980-ies. The basic treatment of keloids changed,
radiotherapy was combined with the above mentioned methods because of its high
recurrence rate. Newer methods, cryosurgery as well as lasers were used to treat
keloids. The number of effective topical agents was increased. The researchers
have been looking for other, intralesionally usable medicine and genetic causes
for more than ten years. The clinicians have had the standard protocols of the
adjunct and alternative methods too. After having the standard and
internationally accepted scar assessment system (Vancouver-scar scale and score),
the controlled, randomized trials were practicable. The prospective evaluation of
the efficacy of different protocols with adequate follow-up became performable.
The comparison of different methods is difficult because of the lack of its
Laser resection of the prostate: implications for anesthesia. Hanson RA, Zornow MH, Conlin MJ, Brambrink AM. Anesth Analg. 2007 Aug;105(2):475-9.
Holmium:yttrium-aluminum-garnet and potassium-titanyl-phosphate lasers make it
possible to perform transurethral prostate resection with almost no absorption of
irrigant and minimal blood loss. Subarachnoid block is usually administered for
classical transurethral resection of the prostate, so that the patient can be
monitored for the onset of transurethral resection of the prostate syndrome
secondary to irrigant absorption. New laser resection techniques may allow the
patient and anesthesiologist to choose options most appropriate for the patient's
medical conditions and preference. In this study, we review the urologic
literature to provide an overview of current laser technology for prostate
reduction surgery. We also screened this literature for evidence of potential
effects on anesthesia care for special patient groups as well as for overall
perioperative management. Our findings suggest that the anesthesiologist may now
safely offer general anesthesia for endourologic laser surgery, even on an
ambulatory basis. This includes patients with cardiovascular disease or receiving
continuous anticoagulation therapy. We found no studies specifically aimed at
evaluating best anesthetic practices for patients undergoing laser procedures.
Therefore, clinical research is needed to better define the risks and benefits of
the various anesthetic alternatives.
Laser photocoagulation for neovascular age-related macular degeneration. Virgili G, Bini A. Cochrane Database Syst Rev. 2007 Jul 18;(3):CD004763.
BACKGROUND: Laser photocoagulation was the first treatment introduced to try to
halt the progression of neovascular age-related macular degeneration (AMD), in
which newly formed vessels or choroidal neovascularisation (CNV) grow under the
macula leading to the occurrence of a scotoma or blind spot in the central visual
field. OBJECTIVES: The aim of this review was to examine the effects of laser
photocoagulation for neovascular AMD. SEARCH STRATEGY: We searched the CENTRAL,
MEDLINE, EMBASE, LILACS, NRR and ZETOC in March 2007. SELECTION CRITERIA: We
included randomised trials of laser photocoagulation in people with CNV due to
AMD. DATA COLLECTION AND ANALYSIS: Two authors independently extracted the data.
The risk ratio (RR) of severe visual loss (loss of six or more lines of visual
acuity) was estimated at three months and two years after treatment. MAIN
RESULTS: Fifteen trials were included in the review (2064 participants). Three
types of photocoagulation were used in the trials: direct photocoagulation of the
entire CNV (11 trials), perifoveal photocoagulation (one trial) and grid
photocoagulation (three trials). In 12 trials the control group was observation
only. One trial compared photocoagulation to submacular surgery and two trials
compared different lasers. Data on the progression of visual loss could be
extracted from five of the eight trials of direct photocoagulation of the CNV
versus observation. The treatment effect was in the direction of harm in all
studies at three months follow up (RR 1.41, 95% confidence intervals (CI) 1.08 to
1.82). After two years the treatment effect was in the direction of benefit (RR
0.67, 95% CI 0.53 to 0.83). These studies were clinically heterogeneous with
participants having CNV lesions in different locations and different baseline
visual acuities. There was little evidence of statistical heterogeneity at three
months but substantial statistical heterogeneity at two years. However, all
treatment effects in the individual trials were in the direction of benefit. One
study comparing perifoveal photocoagulation or observation of subfoveal CNV found
benefits that were statistically significant only at two years (RR 0.36, 95% CI
0.18 to 0.72). Other comparisons did not demonstrate differences. AUTHORS'
CONCLUSIONS: In the medium to long term laser photocoagulation of CNV slows the
progression of visual loss in people with neovascular AMD. However, it is
associated with an increased risk of visual loss immediately after treatment and
this period may be longer in people with subfoveal AMD. With the advent of modern
pharmacological therapies, and concern for the impact of iatrogenic scotoma in
subfoveal CNV, laser photocoagulation of subfoveal CNV is not recommended. No
studies have compared photocoagulation with modern pharmacological agents for AMD
for non-subfoveal CNV.
[KTP laser photovaporization of the prostate] [Article in French] Bruyere F, Traxer O. Prog Urol. 2007 Jun;17(4):783-8.
Transurethral resection of the prostate (TURP) is the operation most frequently
performed in urology. In view of the morbidity associated with this procedure,
technological research has been conducted to propose an endoscopic alternative to
TURP The most promising studies concern application of high energy lasers,
including KTP (potassium-titanyl phosphate) laser. The objective of this study
was to conduct a review of the literature concerning the use of KTP laser for the
endoscopic treatment of BPH (benign prostatic hyperplasia). Preliminary results
published in the international literature concerning KTP laser photovaporization
of the prostate confirm that this technique is effective with decreased
morbidity. This review of the literature appears to reveal several advantages
related to the PVP technique: shorter duration of catheterization and decreased
postoperative bleeding, no irrigation fluid absorption syndrome, short learning
curve and possibility to treat patients on anticoagulant therapy or presenting a
high operative risk, but histological examination of the resected tissue cannot
be performed. Although these results are encouraging, the PVP technique cannot be
proposed as an alternative to TURP in the absence of a multicentre, prospective,
randomized trial. TURP currently remains the reference endoscopic treatment for
BPH and the PVP technique represents an emergent technology that requires
multicentre medico-economic evaluation.
Electrosurgery--have we forgotten it? Buzina DS, Lipozencić J. Acta Dermatovenerol Croat. 2007;15(2):96-102.
The recent appearance of lasers has made electrosurgical methods almost obsolete.
They seem to be routinely avoided by both dermatologists and their patients. In
this paper, the benefits of electrosurgery are emphasized, pointing out that
these are easy to master, efficient and low-cost procedures. An overview of the
five types of cutaneous electrosurgery (electrodesiccation, electrofulguration,
electrocoagulation/electrocutting, electrocautery, and electrolysis) is provided.
Special attention is given to the use of electrosurgery in patients with
electromedical implants. When performed with care, electrosurgery remains a safe,
efficient and low-cost treatment option.
Topical vaccination: the skin as a unique portal to adaptive immune responses. Huang CM. Semin Immunopathol. 2007 Apr;29(1):71-80.
Skin is an ideal tissue for vaccine administration, as it is comprised of
immunocompetent cells such as keratinocytes and Langerhans cells and elicits both
innate and adaptive immune responses. In this paper, we summarize the immune
responses induced by topical vaccination of the skin and review the effects of
adjuvants on skin vaccination. We also summarize the existing techniques for skin
vaccination. New techniques such as the use of lasers to enhance skin
permeability are also discussed, as well as the role of the stratum corneum in
skin vaccination. A recent study demonstrating enhanced skin vaccination by using
surfactants to extract partial lamellar lipids of the stratum corneum will also
be introduced in this review.
Chained lightning, part I: Exploitation of energy and radiobiological principles for therapeutic purposes. Hoh DJ, Liu CY, Pagnini PG, Yu C, Wang MY, Apuzzo ML. Neurosurgery. 2007 Jul;61(1):14-27; discussion 27-8.
The fundamental principle of radiosurgery is the focusing of energy within a
restricted target volume. In examining the history of radiosurgery, various
strategies for addressing this issue of energy containment become apparent. This
is the first in a series of articles that reviews the evolution of radiosurgery
through the development of instruments for beam generation and delivery for
improved conformal therapy. In this first part of the series, we focus
specifically on beam generation and the development of particle beams as the
initial approach in radiosurgery for focused radiation treatment. We examine the
physical characteristics and biological effects of particles and the unique
advantage they confer for radiosurgery. We consider clinical studies and
treatment of neurological diseases with particles and also assess boron neutron
capture therapy as a strategy for selectively targeting neutron beams. Later in
this series, we explore methods of beam delivery with the development of
stereotactic radiosurgery. Finally, we introduce new concepts and applications in
radiosurgery such as nanotechnology, radiation enhancement, ultrasound, near
infrared, and free electron lasers. The elaboration of these efforts sets the
stage for neurosurgeons to further explore new ideas, develop innovative
technology, and advance the practice of radiosurgery.
[Complication of excimer laser refractive surgery] [Article in Romanian] Tudosie M, Burcea M, Tătaru C, Celea C. Oftalmologia. 2007;51(1):29-34.
The success of the refractive surgery depends of the absence of the incidents
during and after the surgery. Any complication can compromise more or less the
result of the intervention and make it inefficient or even injurious.
[How to select patients for excimer laser refractive surgery] [Article in Romanian] Tudosie M, Burcea M, Tătaru C, Celea C. Oftalmologia. 2007;51(1):3-6.
The first very important step for the refractive surgery is the selection of the
patients, because there are situations when the surgery for reducing the diopters
can produce complications which are difficult to solve. The investigation of the
patients who come for a refractive surgery has many steps and each step has his
Murine models of vascular thrombosis (Eitzman series). Westrick RJ, Winn ME, Eitzman DT. Arterioscler Thromb Vasc Biol. 2007 Oct;27(10):2079-93. Epub 2007 Jun 28.
Thrombotic complications of vascular disease are the leading cause of morbidity
and mortality in most industrialized countries. Despite this, safe and effective
drugs targeting these complications are limited, especially in the chronic
setting. This is because of the complexity of thrombosis in both arteries and
veins, which is becoming increasingly evident as numerous factors are now known
to affect the fate of a forming thrombus. To fully characterize thrombus
formation in these settings, in vivo models are necessary to study the various
components and intricate interactions that are involved. Genetic manipulations in
mice are greatly facilitating the dissection of relevant pro- and antithrombotic
influences. Standardized models for the study of thrombosis in mice as well as
evolving techniques that allow imaging of molecular events during thrombus
formation are now available. This review will highlight some of the recent
developments in the field of thrombosis using mouse models and how these studies
are expanding our knowledge of thrombotic disease.
In vivo imaging in experimental preclinical tumor research--a review. Wessels JT, Busse AC, Mahrt J, Dullin C, Grabbe E, Mueller GA. Cytometry A. 2007 Aug;71(8):542-9.
The multiparametric molecular cell and tissue analysis in vitro and in vivo is
characterized by rapid progress in the field of image generation technologies,
sensor biotechnology, and computational modeling. Fascinating new potentials in
unraveling the detailed functions of single cells, organs, and whole organisms
are presently emerging and permit the close monitoring i.e. tumor development or
basic cell development processes with an unprecedented multiplicity of promising
investigative possibilities. To answer basic questions of in vivo tumor
development and progression fluorescence based imaging techniques provide new
insights into molecular pathways and targets. Genetic reporter systems (eGFP,
DsRED) are available and high sensitive detection systems are on hand. These
techniques could be used for in vitro assays and quantified e.g. by microscopy
and CCD based readouts. The introduction of novel fluorescent dyes emitting in
the near infrared range (NIR) combined with the development of sensitive detector
systems and monochromatic powerful NIR-lasers for the first time permits the
quantification and imaging of fluorescence and/or bioluminescence in deeper
tissues. Laser based techniques particularly in the NIR-range (like two-photon
microscopy) offer superb signal to noise ratios, and thus the potential to detect
molecular targets in vivo. In combination with flat panel volumetric computed
tomography (fpVCT), questions dealing e.g. with tumor size, tumor growth, and
angiogenesis/vascularization could be answered noninvasively using the same
animal. The resolution of down to 150 microm/each direction can be achieved using
fpVCT. It is demonstrated by many groups that submillimeter resolutions can be
achieved in small animal imaging at high sensitivity and molecular specificity.
Since the resolution in preclinical small animal imaging is down to approximately
10 microm by the use of microCT and to subcellular resolutions using (
approximately 1 microm) microscope based systems, the advances of different
techniques can now be combined to "multimodal" preclinical imaging and the
possibilities for in vivo intravital cytometry now become within one's reach.
Copyright 2007 International Society for Analytical Cytology.
Laser technology: its application in the management of hemangiomas and vascular malformations of the head and neck. Lang PG Jr. Facial Plast Surg Clin North Am. 2001 Nov;9(4):577-83.
Lasers have added greatly to our armamentarium for managing vascular lesions. The
ideal laser, however, has not yet been built that can effectively treat vessels
of all sizes and depths. As knowledge of vascular lesions grow and laser
technology advances, it may be possible to create such a laser. Until then, it
will be necessary to use a combination of lasers and to combine lasers with other
modalities to effectively manage the broad spectrum of vascular lesions.
Intracorneal rings for keratoconus and keratectasia. Ertan A, Colin J. J Cataract Refract Surg. 2007 Jul;33(7):1303-14.
Intrastromal corneal ring segments were designed to achieve refractive adjustment
by flattening the cornea. Recently, they have been used to reshape keratoconic
corneas to improve uncorrected visual acuity, best corrected visual acuity, and
contact lens tolerance and to delay or prevent the need for keratoplasty.
Intracorneal ring segments have several distinct and important advantages. New
thicknesses and different ring sizes and the use of femtosecond lasers to dissect
channels inside the cornea will likely improve the surgical outcomes. This
article reviews the latest data published or presented at meetings on the
correction of keratoconus and keratectasia by intracorneal ring segments.
Investigating relaxation processes in cells and developing organisms: from cell ablation to cytoskeleton nanosurgery. Colombelli J, Reynaud EG, Stelzer EH. Methods Cell Biol. 2007;82:267-91.
Dynamic microscopy of living cells and organisms alone does not reveal the high
level of complexity of cellular and subcellular organization. All observable
processes rely on the activity of biochemical and biophysical processes and many
occur at a physiological equilibrium. Experimentally, it is not trivial to apply
a perturbation that targets a specific process without perturbing the overall
equilibrium of a cell. Drugs and more recently RNAi certainly have general and
undesired effects on cell physiology and metabolism. In particular, they affect
the entire cell. Pulsed lasers allow to severe biological tissues with a
precision in the range of hundreds of nanometers and to achieve ablation on the
level of a single cell or a subcellular compartment. In this chapter, we present
an efficient implementation of a picosecond UV-A pulsed laser-based nanosurgery
system and review the different mechanisms of ablation that can be achieved at
different levels of cellular organization. We discuss the performance of the
ablation process in terms of the energy deposited onto the sample and compare our
implementation to others recently employed for cellular and subcellular surgery.
Above the energy threshold of ionization, we demonstrate how to achieve
single-cell ablation through the induction of mechanical perturbation and
cavitation in living organisms. Below this threshold, we induce cytoskeleton
severing inside live cells. By combining nanosurgery with fast live-imaging
fluorescence microscopy, we show how the apparent equilibrium of the cytoskeleton
can be perturbed regionally inside a cell.
Laser microsurgery in the GFP era: a cell biologist's perspective. Magidson V, Loncarek J, Hergert P, Rieder CL, Khodjakov A. Methods Cell Biol. 2007;82:239-66.
Modern biology is based largely on a reductionistic "dissection" approach-most
cell biologists try to determine how complex biological systems work by removing
their individual parts and studying the effects of this removal on the system. A
variety of enzymatic and mechanical methods have been developed to dissect large
cell assemblies like tissues and organs. Further, individual proteins can be
inactivated or removed within a cell by genetic manipulations (e.g., RNAi or gene
knockouts). However, there is a growing demand for tools that allow intracellular
manipulations at the level of individual organelles. Laser microsurgery is
ideally suited for this purpose and the popularity of this approach is on the
rise among cell biologists. In this chapter, we review some of the applications
for laser microsurgery at the subcellular level and describe practical
requirements for laser microsurgery instrumentation demanded in the field. We
also outline a relatively inexpensive but versatile laser microsurgery
workstation that is being used in our laboratory. Our major thesis is that the
limitations of the technology are no longer at the level of the laser,
microscope, or software, but instead only in defining creative questions and in
visualizing the target to be destroyed.
Principles of laser microdissection and catapulting of histologic specimens and live cells. Vogel A, Horneffer V, Lorenz K, Linz N, Hüttmann G, Gebert A. Methods Cell Biol. 2007;82:153-205.
Rapid contact- and contamination-free procurement of specific samples of
histologic material for proteomic and genomic analysis as well as separation and
transport of living cells can be achieved by laser microdissection (LMD) of the
sample of interest followed by a laser-induced forward transport process [laser
pressure "catapulting," (LPC)] of the dissected material. We investigated the
dynamics of LMD and LPC with focused and defocused laser pulses by means of
time-resolved photography. The working mechanism of microdissection was found to
be plasma-mediated ablation. Catapulting is driven by plasma formation, when
tightly focused pulses are used, and by ablation at the bottom of the sample for
moderate and strong defocusing. Driving pressures of several hundred megapascals
accelerate the specimen to initial velocities of 100-300 m/s before it is rapidly
slowed down by air friction. With strong defocusing, driving pressure and initial
flight velocity decrease considerably. On the basis of a characterization of the
thermal and optical properties of the histologic specimens and supporting
materials used, we calculated the temporal evolution of the heat distribution in
the sample. After laser microdissection and laser pressure catapulting (LMPC),
the samples were inspected by scanning electron microscopy. Catapulting with
tightly focused or strongly defocused pulses results in very little collateral
damage, while slight defocusing involves significant heat and UV exposure of up
to about 10% of the specimen volume, especially if samples are catapulted
directly from a glass slide. Time-resolved photography of live-cell catapulting
revealed that in defocused catapulting strong shear forces originate from the
flow of the thin layer of culture medium covering the cells. By contrast, pulses
focused at the periphery of the specimen cause a fast rotational movement that
makes the specimen wind its way out of the culture medium, thereby undergoing
much less shear stresses. Therefore, the recultivation rate of catapulted cells
was much higher when focused pulses were used.
Mechanisms of laser cellular microsurgery. Quinto-Su PA, Venugopalan V. Methods Cell Biol. 2007;82:113-51.
This chapter reviews the optics of pulsed laser microbeams and the use of basic
instrumentation to provide pulsed laser microbeam capabilities within a
microscope platform. Moreover, we review the principal mechanisms by which laser
microbeams produce microsurgical effects in cellular targets. We discuss the
principal photothermal, photomechanical, and photochemical damage mechanisms as
well as their relationship to critical laser microbeam parameters, including
wavelength, pulse duration, and numerical aperture. We relate this understanding
of damage mechanisms to laser microbeam applications reported in the literature.
Laser-based measurements in cell biology. Botvinick EL, Shah JV. Methods Cell Biol. 2007;82:81-109.
In this chapter, we review the imaging techniques and methods of molecular
interrogation made possible by integrating laser light sources with microscopy.
We discuss the advantages of exciting fluorescence by laser illumination and
review commonly used laser-based imaging techniques such as confocal,
multiphoton, and total internal reflection microcopy. We also discuss emerging
imaging modalities based on intrinsic properties of biological macromolecules
such as second harmonic generation imaging and coherent anti-Raman resonance
spectroscopy. Super resolution techniques are presented that exceed the
theoretical diffraction-limited resolution of a microscope objective. This
chapter also focuses on laser-based techniques that can report biophysical
parameters of fluorescently labeled molecules within living cells. Photobleaching
techniques, fluorescence lifetime imaging, and fluorescence correlation methods
can measure kinetic rates, molecular diffusion, protein-protein interactions, and
concentration of a fluorophore-bound molecule. This chapter provides an
introduction to the field of laser-based microscopy enabling readers to determine
how best to match their research questions to the current suite of techniques.
Selected applications of laser scissors and tweezers and new applications in heart research. Greulich KO. Methods Cell Biol. 2007;82:59-80.
This contribution bridges the gap from early European contributions via laser
micromanipulation to recent work on the use of laser microbeams and optical
tweezers in studies of basic aspects of heart infarction. Laser transfection,
particularly of plant cells and their chloroplasts, and laser microdissection of
chromosomes with subsequent generation of chromosome segment-specific DNA
libraries and laser-induced cell fusion are reported. With optical tweezers,
microgravity can be simulated in roots of the alga Chara. Surprisingly,
microgravity reduces growth. In some plant cells, CW lasers, in principle suited
primarily for optical tweezers, can be used as microbeam. Also, it is shown that
natural killer cells mount an attack on leukemia cells even in the absence of
specificity, just induced by exerting force with optical tweezers. Finally, with
the help of a laser microbeam, lesions can be induced to study wound healing
after heart infarction. A modification of optical tweezers, the
erythrocyte-mediated force application (EMFA) technique can be used to induce
calcium waves not only in tissue reconstituted from excitable heart muscle cells
but also from nonexcitable fibroblasts.
A history of laser scissors (microbeams). Berns MW. Methods Cell Biol. 2007;82:1-58.
This introductory chapter reviews the history of microbeams starting with the
original UV microbeam work of Tchakhotine in 1912 and covers the progress and
application of microbeams through 2006. The main focus of the chapter is on laser
"scissors" starting with Marcel Bessis' and colleagues work with the ruby laser
microbeam in Paris in 1962. Following this introduction, a section is devoted to
describing the different laser microbeam systems and then the rest of the chapter
is devoted to applications in cell and developmental biology. The approach is to
focus on the organelle/structure and describe how the laser microbeam has been
applied to studying its structure and/or function. Since considerable work has
been done on chromosomes and the mitotic spindle (Section V.A and C), these
topics have been divided in distinct subsections. Other topics discussed are
injection of foreign DNA through the cell membrane (optoporation/optoinjection),
cell migration, the nucleolus, mitochondria, cytoplasmic filaments, and embryos
fate-mapping. A final technology section is devoted to discussing the pros and
cons of building/buying your own laser microbeam system and the option of using
the Internet-based RoboLase system. Throughout the chapter, reference is made to
other chapters in the book that go into more detail on the subjects briefly
Greenlight prostatectomy: a challenge to the gold standard? A review of KTP photoselective vaporization of the prostate. Ahmed HU, Thwaini A, Shergill IS, Hammadeh MY, Arya M, Kaisary AV. Surg Laparosc Endosc Percutan Tech. 2007 Jun;17(3):156-63.
The use of lasers to carry out resection of the prostate gland is an
ever-evolving field which has seen several different modalities of laser light
used with varying success. This review looks at what makes the traditional
transurethral resection of prostate the gold standard and provides the evidence
on the evolution of the laser prostatectomy in trying to usurp it as the favored
procedure for symptomatic benign prostatic hyperplasia. In particular, we show
how the latest laser technology in the form of the Greenlight laser is
challenging not only other lasers such as the holmium laser, but may form a
strong contender to replace the transurethral resection of prostate.
The future of lasers in urology. Pierre SA, Albala DM. World J Urol. 2007 Jun;25(3):275-83. Epub 2007 Jun 14.
The use of laser applications in urology has undergone significant advances over
the past 20 years. Laser technology is now used in a wide variety of procedures,
and has become the primary treatment modality or standard of care for many
urologic conditions. Despite these advances, a number of challenges still face
laser utilization in urologic practice. Recent work has illuminated the potential
improvement and further optimization of this field. Improvements in types of
lasers, the wavelength of energy used, optical fiber delivery systems, precision
of laser application and cost reduction have served to further improve laser
technology and extend the potential applications.
Lasers in the upper urinary tract for non-stone disease. Phillips CK, Landman J. World J Urol. 2007 Jun;25(3):249-56. Epub 2007 Jun 12.
Though the most common use for lasers in the genitourinary tract is for
urolithiasis, a number of other urologic conditions can be treated with lasers
because of their unique ablative, destructive and hemostatic properties. This
paper reviews the advantages and disadvantages of laser technology for a number
of non-stone indications.
Correlating purity by microdissection with gene expression in gastric cancer tissue. Otsuka Y, Ichikawa Y, Kunisaki C, Matsuda G, Akiyama H, Nomura M, Togo S, Hayashizaki Y, Shimada H. Scand J Clin Lab Invest. 2007;67(4):367-79.
Microdissection is a feasible tool for the purification of target cells from
heterogeneous tissue components. However, the extent to which cells need to be
purified by microdissection for use in gene expression analysis has not been
determined. In the present study, we obtained diffuse-type gastric cancer tissues
at varying purities, and evaluated the corresponding expression of a
cancer-specific gene, KRT19, by quantitative real-time PCR. The relationship
between the degree of purity and gene expression was confirmed by using 60-mer
oligonucleotide microarray analysis. Cancer-specific gene expression was stable
in tissues of 10-50% purity, but at 60% or greater purity the slope of the graph
was much steeper, indicating a correlation between tissue purity and increased
gene expression. Tissues of 70% purity for cancer cells, acquired by
microdissection, were therefore deemed to be of sufficient quality to distinguish
between gene expression profiles from microdissected and non-microdissected
Vascular lasers and IPLS: guidelines for care from the European Society for Laser Dermatology (ESLD). Adamic M, Troilius A, Adatto M, Drosner M, Dahmane R. J Cosmet Laser Ther. 2007 Jun;9(2):113-24.
Dermatology and dermatologic surgery have rapidly evolved during the last two
decades thanks to the numerous technological and scientific acquisitions focused
on improved precision in the diagnosis and treatment of skin alterations. Given
the proliferation of new devices for the treatment of vascular lesions, we have
considerably changed our treatment approach. Lasers and non-coherent intense
pulse light sources (IPLS) are based on the principle of selective
photothermolysis and can be used for the treatment of many vascular skin lesions.
A variety of lasers has recently been developed for the treatment of congenital
and acquired vascular lesions which incorporate these concepts into their design.
The list is a long one and includes pulsed dye (FPDL, APDL) lasers (577 nm, 585
nm and 595 nm), KTP lasers (532 nm), long pulsed alexandrite lasers (755 nm),
pulsed diode lasers (in the range of 800 to 900 nm), long pulsed 1064 Nd:YAG
lasers and intense pulsed light sources (IPLS, also called flash-lights or pulsed
light sources). Several vascular lasers (such as argon, tunable dye, copper
vapour, krypton lasers) which were used in the past are no longer useful as they
pose a higher risk of complications such as dyschromia (hypopigmentation or
hyperpigmentation) and scarring. By properly selecting the wavelength which is
maximally absorbed by the target--also called the chromophore (haemoglobin in the
red blood cells within the vessels)--and a corresponding pulse duration which is
shorter than the thermal relaxation time of that target, the target can be
preferentially injured without transferring significant amounts of energy to
surrounding tissues (epidermis and surrounding dermal tissue). Larger structures
require more time for sufficient heat absorption. Therefore, a longer laser-pulse
duration has to be used. In addition, more deeply situated vessels require the
use of longer laser wavelengths (in the infrared range) which can penetrate
deeper into the skin. Although laser and light sources are very popular due to
their non-invading nature, caution should be considered by practitioners and
patients to avoid permanent side effects. These guidelines focus on patient
selection and treatment protocol in order to provide safe and effective
treatment. Physicians should always make the indication for the treatment and are
responsible for setting the machine for each individual patient and each
individual treatment. The type of laser or IPLS and their specific parameters
must be adapted to the indication (such as the vessel's characteristics, e.g.
diameter, colour and depth, the Fitzpatrick skin type). Treatments should start
on a test patch and a treatment grid can improve accuracy. Cooling as well as a
reduction of the fluence will prevent adverse effects such as pigment alteration
and scar formation. A different number of repeated treatments should be done to
achieve complete results of different vascular conditions. Sunscreen use before
and after treatment will produce and maintain untanned skin. Individuals with
dark skin, and especially tanned patients, are at higher risk for pigmentary
changes and scars after the laser or IPLS treatment.
[Treatment of varicose veins and telangiectasias] [Article in French] Noël B. Rev Med Suisse. 2007 May 2;3(109):1124-9.
Dermatologic surgery has evolved enormously within the past few years especially
for the treatment of varicose veins and telangiectasias. New minimally-invasive
techniques have been developed: lasers, echo-sclerosis, surgery with tumescent
anesthesia and endovascular treatment of saphenous veins. Most interventions can
be performed with local anesthesia in the office setting. These new treatments
are intended to decrease the risks of surgery, reduce medical costs and the
necessity for hospitalization, and improve functional and esthetic results.
Photodynamic therapy with lasers and intense pulsed light. Gold MH. Facial Plast Surg Clin North Am. 2007 May;15(2):145-60, v.
For many physicians, photodynamic therapy has become a routine part of using
lasers and light sources to improve the outcomes of photorejuvenation therapies.
Aminolevulinic acid photodynamic therapy (ALA-PDT) was first used in the
treatment of actinic keratoses in the United States. It quickly became evident
that PDT therapy for actinic keratoses had an additional cosmetic benefit, and
clinical trials have confirmed the effectiveness of ALA-PDT in treating
photorejuvenation with or without associated actinic keratoses. This article
reviews the peer-reviewed literature regarding ALA-PDT in photorejuvenation and
also summarizes the author's own techniques in using this new and exciting
What have we learnt about heavy carbenes through laser flash photolysis studies? Becerra R, Walsh R. Phys Chem Chem Phys. 2007 Jun 14;9(22):2817-35. Epub 2007 Mar 14.
Time resolved gas-phase kinetic studies have contributed a great deal of
fundamental information about the reactions and reactivity of heavy carbenes
(silylenes, germylenes and stannylenes) during the past two decades. In this
article we trace the development of our understanding through the mechanistic
themes of intermediate complexes, third body assisted associations, catalysed
reactions, non-observed reactions and substituent effects. Ab initio (quantum
chemical) calculations have substantially assisted mechanistic interpretation and
are discussed where appropriate. Trends in reactivity are identified and some
signposts to future studies are indicated. This review, although detailed, is not
Technical aspects of lasers in urology. Teichmann HO, Herrmann TR, Bach T. World J Urol. 2007 Jun;25(3):221-5. Epub 2007 May 30.
During the course of history a variety of laser principles have been introduced
in surgery. Some erroneous developments probably could have been kept out of the
market place if not for the magic which accompanies the acronym LASER and with
more understanding for the underlying principles governing the process when light
meets tissue. The interaction of light with tissue is exemplified on the basis of
natural body chromophores when compared with available lasers at different
wavelengths and operational modes. Furthermore the meaning of fibre flexibility
and durability is elucidated.
Laser treatment of benign prostatic hyperplasia. Kuntz RM. World J Urol. 2007 Jun;25(3):241-7. Epub 2007 May 25.
To evaluate the role of lasers that allow acute removal of obstructing tissue in
the surgical treatment of benign prostatic hyperplasia (BPH). A MEDLINE search
over the last 6 years focused on randomized trials, large case series and review
articles. A total of more than 4,000 patients were analyzed with respect to the
morbidity and outcome, and the advantages and disadvantages of the various
lasers. Laser treatment of BPH has evolved from coagulation to enucleation. Blood
loss is significantly reduced as compared to transurethral resection and open
prostatectomy. Ablative/vaporizing techniques have recently become popular again
with the marketing of new high-powered 80 W potassium-titanyl-phosphate (KTP) and
100 W holmium lasers. Vaporization immediately removes obstructing tissue, but
tissue specimen cannot be obtained. KTP short-term results are promising, but
long-term results and randomized trials are lacking. Postoperative volume
reduction is less than with holmium laser enucleation of the prostate (HoLEP),
and the KTP laser can be used for BPH treatment only. HoLEP allows whole lobes of
the prostate to be removed. Prostates of all sizes can be operated on. It is at
least as safe and effective as TURP and open prostatectomy, with significantly
lower morbidity, as shown by several well-designed randomized clinical trials. It
provides specimen for histological evaluation. In addition, the holmium laser can
be used for the endourological treatment of stones, strictures and tumors. HoLEP
appears to be a size-independent new "gold standard" in the surgical treatment of
Robots and lasers: the future of cardiac tissue ablation? Smith JM. Int J Med Robot. 2006 Dec;2(4):329-32.
BACKGROUND: The future of medicine is tied-up in robotics and lasers. We've heard
the hype for years, but only in the last 10 years has it actually started to come
to fruition that robotic systems are beginning to play a role in surgery.
METHODS: Multiple groups have reported over the past 10 years on increasingly
complex cardiac surgical procedures being performed with the aid of robotic
systems. With an increasing percentage of atrial fibrillation and with insight
that atrial fibrillation results in poor long-term survival, attempts have been
made to create a surgical cure. RESULTS: Much work has been done in the past
several years to develop a less-invasive surgical option than the standard
cut-and-sew Maze to achieve pulmonary vein ablation. Laser is a unique energy
source for tissue ablation because it is a form of light. CONCLUSION: While
traditional energy sources focus on applying heat-based elements to the tissue's
surface allowing temperature to propagate across the thickness of the tissue
laser is an innovative, tissue-specific energy for creating tissue ablation.
Copyright 2006 John Wiley & Sons, Ltd.
Fluorescence correlation spectroscopy: molecular complexing in solution and in living cells. Bulseco DA, Wolf DE. Methods Cell Biol. 2007;81:525-59.
Femtosecond quantum control of molecular dynamics in the condensed phase. Nuernberger P, Vogt G, Brixner T, Gerber G. Phys Chem Chem Phys. 2007 May 28;9(20):2470-97. Epub 2007 Mar 13.
We review the progress in controlling quantum dynamical processes in the
condensed phase with femtosecond laser pulses. Due to its high particle density
the condensed phase has both high relevance and appeal for chemical synthesis.
Thus, in recent years different methods have been developed to manipulate the
dynamics of condensed-phase systems by changing one or multiple laser pulse
parameters. Single-parameter control is often achieved by variation of the
excitation pulse's wavelength, its linear chirp or its temporal subpulse
separation in case of pulse sequences. Multiparameter control schemes are more
flexible and provide a much larger parameter space for an optimal solution. This
is realized in adaptive femtosecond quantum control, in which the optimal
solution is iteratively obtained through the combination of an experimental
feedback signal and an automated learning algorithm. Several experiments are
presented that illustrate the different control concepts and highlight their
broad applicability. These fascinating achievements show the continuous progress
on the way towards the control of complex quantum reactions in the condensed
Laser welding thermoplastics. [No authors listed] Med Device Technol. 2007 Mar-Apr;18(2):54-5.
The use of infrared absorbers is advised for successful laser transmission
welding of thermoplastics.
[Laser capture microdissection: a new tool for the study of cerebral ischemia] [Article in Spanish] Cuadrado E, Rosell A, Alvarez-Sabín J, Montaner J. Rev Neurol. 2007 May 1-15;44(9):551-5.
AIM: To review studies using microscopy techniques of laser capture
microdissection on cerebral tissue and the possible applications of this
methodology for the study of cerebral ischemia. DEVELOPMENT: Since ischemic
stroke induces neuronal death following the occlusion of a brain artery,
reperfusion and neuroprotective treatments are the only therapeutic strategies
used so far. However, the relevant role of other brain cells such as astrocytes,
oligodendrocytes, microglial and endothelial cells, or even the extracellular
matrix itself, in several steps of the ischemic cascade, adds a huge complexity
to stroke. In this scenario lesser simplistic approaches will be required.
Therefore, the individual study of all cellular populations involved in cerebral
ischemia seems mandatory to determine the cellular source of all participant
molecules. Laser capture microdissection appears as a rapid, efficient and
precise technique to isolate cell populations for further analysis of gene
expression or proteomics. CONCLUSIONS: Laser capture microdissection is a useful
and reliable technique to obtain specific cell groups that might guide us to
distinguish the cellular origin of the main molecules that are involved in the
different steps of the ischemic cascade.
[Myopia and glaucoma] [Article in German] Faschinger C, Mossböck G. Wien Med Wochenschr. 2007;157(7-8):173-7.
The question is whether there is an increased risk to develop glaucoma in
co-existing myopia. The different kinds of glaucoma dealing with this problem are
described. The highly myopic eye with increased axial length shows many
structural changes. Especially the changes of the optic nerve head in a highly
myopic eye make it very difficult to differentiate between a beginning glaucoma
and a normal structure or to define a progression of glaucomatous changes. The
visual field defects are often close to fixation and may reduce visual acuity and
therefore the quality of life of these usually younger patients. An increase of
the thickness of the lens induced by senile cataract, drugs or diabetes mellitus,
a forward shift of the lens or the iris-lens-diaphragm will lead to refractive
myopia and may provoke an angle closure glaucoma. Pigmentary glaucoma occurs in
younger patients in connection with low or medium myopia and more rapidly
destroys the optic nerve head due to higher intraocular pressure values in
comparison to the primary open-angle glaucoma. After refractive surgeries of
myopic eyes one has to expect different kinds of glaucoma (steroid induced,
pupillary block, angle closure). Due to the increased risk to develop glaucoma
patients especially with high myopia are advised to consult their ophthalmologist
on a regular basis.
Ultrafast dynamics in complex fluids observed through the ultrafast optically-heterodyne-detected optical-Kerr-effect (OHD-OKE). Hunt NT, Jaye AA, Meech SR. Phys Chem Chem Phys. 2007 Jun 14;9(18):2167-80. Epub 2007 Feb 7.
The ultrafast molecular dynamics of complex fluids have been recorded using the
optically-heterodyne-detected optical-Kerr-effect (OHD-OKE). The OHD-OKE method
is reviewed and some recent refinements to the method are described. Applications
to a range of complex fluids, including microemulsions, polymer melts and
solutions, liquid crystal and ionic liquids are surveyed. The level of detail
attainable with the OHD-OKE method in these complex fluids is discussed. The
prospects for future experiments are discussed.
Using lasers for phase one periodontal therapy. Coluzzi DJ. Dent Today. 2007 Apr;26(4):124, 126-9; quiz 129.
Office-based laryngeal laser surgery with local anesthesia. Zeitels SM, Burns JA. Curr Opin Otolaryngol Head Neck Surg. 2007 Jun;15(3):141-7.
PURPOSE OF REVIEW: Office-based laryngeal laser surgery was created recently and
is emerging as a reliable and practical method of treating a number of laryngeal
lesions. This style of minimally invasive surgery is becoming increasingly
popular in the United States and abroad. RECENT FINDINGS: Fiber-based lasers and
distal-chip flexible endoscopy have facilitated a new style of surgery.
Epithelial diseases such as dysplasia and papillomatosis are well suited for
treatment. Although the initial angiolytic laser used was a 585-nm pulsed-dye
laser, the 532-nm pulsed-potassium-titanyl-phosphate laser has been demonstrated
to be more effective. The 2013-nm Thulium laser shows promise as an office-based
laser that simulates the properties of the carbon dioxide laser. SUMMARY:
Evolving technologies to enhance laryngoscopic imaging and lasers along with
socioeconomic forces should lead to increasing numbers of laryngeal procedures
being performed in the office with local anesthesia.
Combined Raman spectrometer/laser-induced breakdown spectrometer for the next ESA mission to Mars. Bazalgette Courrèges-Lacoste G, Ahlers B, Pérez FR. Spectrochim Acta A Mol Biomol Spectrosc. 2007 Dec 15;68(4):1023-8. Epub 2007 Mar 24.
Among the different instruments that have been pre-selected to be on-board the
Pasteur payload on ExoMars is the Raman/laser induced breakdown spectroscopy
(LIBS) instrument. Raman spectroscopy and LIBS will be integrated into a single
instrument sharing many hardware commonalities. An international team under the
lead of TNO has been gathered to produce a design concept for a combined Raman
spectrometer/LIBS elegant bread-board (EBB). The instrument is based on a
specially designed, extremely compact, spectrometer with high resolution over a
large wavelength range, suitable for both Raman spectroscopy and LIBS
measurements. Low mass, size and power consumption are the main drivers of the
instrument's design concept. In this paper, science objectives for the combined
instrument are detailed. Background information on Raman spectroscopy and LIBS
are presented, focussing on the synergy of these two techniques. In the last
section, the instrument concept resulting from the assessment of the feasibility
of the combined Raman/LIBS EBB is presented.
An overview of laser microdissection technologies. Murray GI. Acta Histochem. 2007;109(3):171-6. Epub 2007 Apr 25.
The development of laser-based tissue microdissection systems has provided the
basis for the rapid acquisition of specific morphologically and/or phenotypically
distinct types of cells for many types of molecular analysis. Two laser
microdissection technologies based on distinct principles have been developed,
namely: laser capture microdissection and laser cutting microdissection. This
commentary will outline the principles of each system and indicate their main
advantages and potential drawbacks. Also discussed will be methods of cell and
tissue preparation with particular reference to fixation and staining, which are
crucial to both successful laser-based microdissection and also downstream
molecular studies. Laser microdissection techniques are powerful technologies
which combine morphology and histochemistry with sophisticated molecular
analysis. Through their appropriate application they have provided significant
new insights into cell biology and pathology.
An introduction into proteomics and its clinical applications. Ahram M. Saudi Med J. 2007 Apr;28(4):499-507.
The completion of the human genome project has marked the official start of the
post-genomic era. Due to limitations in DNA and RNA studies, the advent of
proteomics, or large-scale analysis of proteins, is considered a crucial
consequence and a chief player of post-genomic initiatives. An immediate goal of
proteomic studies is the understanding of proteins including their expression,
function, interaction, and structure with an endpoint of discovery of protein
biomarkers. Such biomarkers can be used in detection, prognostication, and
treatment of diseases. However, the challenge of studying complete sets of
cellular proteins, or proteomes, is driving the development of newer
technologies. In this review, a discussion of proteomic biotechnologies and their
clinical applications is offered. The main techniques covered are the
2-dimensional polyacrylamide gel electrophoresis, mass spectrometry,
surface-enhanced laser desorption ionization mass spectrometry, and protein
microarrays. These tools have been successfully utilized in analyzing human and
other biological samples in discovery of biomarkers. Recent advancement in
proteomics has added and will continue to add valuable information to our
knowledge-base of the human biological system.
Enhancing cosmetic outcomes by combining superficial glycolic acid (alpha-hydroxy acid) peels with nonablative lasers, intense pulsed light, and trichloroacetic acid peels. Effron C, Briden ME, Green BA. Cutis. 2007 Jan;79(1 Suppl Combining):4-8.
Nonablative lasers, intense pulsed light (IPL), and trichloroacetic acid (TCA)
peels are cosmetic rejuvenation techniques used to remodel skin and provide
improved skin texture, firmness, and even pigmentation. Glycolic acid is an
alpha-hydroxy acid that can be used as a topical skin peel to provide important
complementary benefits to nonablative lasers, IPL, and TCA peels. Superficial
glycolic acid peels provide both epidermal and dermal antiaging benefits, can be
used to smooth the stratum corneum to reduce light scattering, and can enable the
use of lower concentrations of TCA during a peel procedure. When used with these
procedures, glycolic acid peels can enhance skin benefits and perceived patient
outcomes. Methods of combining nonablative lasers, IPL, and TCA peels with
glycolic acid peels were discussed at a dermatologist roundtable event and are
summarized in this article.
Application of femtosecond-laser induced nanostructures in optical memory. Shimotsuma Y, Sakakura M, Miura K, Qiu J, Kazansky PG, Fujita K, Hirao K. J Nanosci Nanotechnol. 2007 Jan;7(1):94-104.
The femtosecond laser induced micro- and nanostructures for the application to
the three-dimensional optical data storage are investigated. We have observed the
increase of refractive index due to local densification and atomic defect
generation, and demonstrated the real time observation of photothermal effect
after the femtosecond laser irradiation inside a glass by the transient lens
(TrL) method. The TrL signal showed a damped oscillation with about an 800 ps
period. The essential feature of the oscillation can be reproduced by the
pressure wave creation and propagation to the outward direction from the
irradiated region. The simulation based on elastodynamics has shown that a large
thermoelastic stress is relaxed by the generation of the pressure wave. In the
case of soda-lime glass, the velocity of the pressure wave is almost same as the
longitudinal sound velocity at room temperature (5.8 microm/ns). We have also
observed the localized photo-reduction of Sm3+ to Sm2+ inside a transparent and
colorless Sm(3+)-doped borate glass. Photoluminescence spectra showed that some
the Sm3+ ions in the focal spot within the glass sample were reduced to Sm2+ ions
after femtosecond laser irradiation. A photo-reduction bit of 200 nm in
three-dimensions can be recorded with a femtosecond laser and readout clearly by
detecting the fluorescence excited by Ar+ laser (lambda = 488 nm). A
photo-reduction bit can be also erased by photo-oxidation with a cw Ar+ laser
(lambda = 514.5 nm). Since photo-reduction bits can be spaced 150 nm apart in a
layer within glass, a memory capacity of as high as 1 Tbit can be achieved in a
glass piece with dimensions of 10 mm x 10 mm x 1 mm. We have also demonstrated
the first observation of the polarization-dependent periodic nanostructure
formation by the interference between femtosecond laser light and electron
acoustic waves. The observed nanostructures are the smallest embedded structures
ever created by light. The period of self-organized nanostructures can be
controlled from approximately 140 to 320 nm by the pulse energy and the number of
irradiated pulses. Furthermore, we have also observed the self-assembled
sub-wavelength periodic structures created in silica glass by femtosecond pulses
on the plane of the propagation of light.
Nanophase change for data storage applications. Shi LP, Chong TC. J Nanosci Nanotechnol. 2007 Jan;7(1):65-93.
Phase change materials are widely used for date storage. The most widespread and
important applications are rewritable optical disc and Phase Change Random Access
Memory (PCRAM), which utilizes the light and electric induced phase change
respectively. For decades, miniaturization has been the major driving force to
increase the density. Now the working unit area of the current data storage media
is in the order of nano-scale. On the nano-scale, extreme dimensional and
nano-structural constraints and the large proportion of interfaces will cause the
deviation of the phase change behavior from that of bulk. Hence an in-depth
understanding of nanophase change and the related issues has become more and more
important. Nanophase change can be defined as: phase change at the scale within
nano range of 100 nm, which is size-dependent, interface-dominated and
surrounding materials related. Nanophase change can be classified into two
groups, thin film related and structure related. Film thickness and clapping
materials are key factors for thin film type, while structure shape, size and
surrounding materials are critical parameters for structure type. In this paper,
the recent development of nanophase change is reviewed, including crystallization
of small element at nano size, thickness dependence of crystallization, effect of
clapping layer on the phase change of phase change thin film and so on. The
applications of nanophase change technology on data storage is introduced,
including optical recording such as super lattice like optical disc,
initialization free disc, near field, super-RENS, dual layer, multi level, probe
storage, and PCRAM including, superlattice-like structure, side edge structure,
and line type structure. Future key research issues of nanophase change are also
Integrated microfluidic platform for oral diagnostics. Herr AE, Hatch AV, Giannobile WV, Throckmorton DJ, Tran HM, Brennan JS, Singh AK. Ann N Y Acad Sci. 2007 Mar;1098:362-74.
While many point-of-care (POC) diagnostic methods have been developed for
blood-borne analytes, development of saliva-based POC diagnostics is in its
infancy. We have developed a portable microfluidic device for detection of
potential biomarkers of periodontal disease in saliva. The device performs rapid
microfluidic chip-based immunoassays (<3-10 min) with low sample volume
requirements (10 microL) and appreciable sensitivity (nM-pM). Our microfluidic
method facilitates hands-free saliva analysis by integrating sample pretreatment
(filtering, enrichment, mixing) with electrophoretic immunoassays to quickly
measure analyte concentrations in minimally pretreated saliva samples. The
microfluidic chip has been integrated with miniaturized electronics, optical
elements, such as diode lasers, fluid-handling components, and data acquisition
software to develop a portable, self-contained device. The device and methods are
being tested by detecting potential biomarkers in saliva samples from patients
diagnosed with periodontal disease. Our microchip-based analysis can readily be
extended to detection of biomarkers of other diseases, both oral and systemic, in
saliva and other oral fluids.
[Development of optical introscopy in medical engineering] [Article in Russian] Podgaetskiĭ VM, Potapov DA, Selishchev SV, Tereshchenko SA. Med Tekh. 2007 Jan-Feb;(1):4-9.
The basic features of the process of development of medical optical introscopes
are considered. Design characteristics of preproduction and production models of
devices for diagnosis of the brain and the mammary gland are described.
Neurosurgical management of intramedullary spinal cord tumors in children. Kothbauer KF. Pediatr Neurosurg. 2007;43(3):222-35.
The majority of intramedullary spinal cord tumors in children are low-grade glial
tumors. They become symptomatic with pain, neurologic deficits or spinal
deformity. The diagnosis is most readily obtained using magnetic resonance
imaging. The natural history is significant for slow progression of symptoms.
Surgery is the best treatment and is also indicated to confirm the histological
diagnosis. In case of a low-grade tumor or a vascular lesion such as
hemangioblastoma or cavernoma, a total or near-total resection is attempted. For
astrocytomas the resection almost always remains biologically incomplete, but a
near-total resection is still associated with a long progression-free survival.
Neurologic morbidity is relatively low during long-term follow-up but can be up
to 30% for transient motor deficits. The risk for neurologic deterioration is
higher for patients with pronounced dysfunction preoperatively. This is an
important argument for early surgical resection. Surgery is performed using the
spectrum of microsurgical techniques as well as advanced technology, e.g. lasers
and intraoperative neurophysiological monitoring with motor evoked potentials.
High-grade tumors are resected conservatively and treated with radiation and
chemotherapy. The prognosis of high-grade glial tumors remains poor.
An overview of energy sources in clinical use for the ablation of atrial fibrillation. Comas GM, Imren Y, Williams MR. Semin Thorac Cardiovasc Surg. 2007 Spring;19(1):16-24.
Recent years have seen many developments in the field of alternative energy
sources for arrhythmia surgery. The impetus behind these advances is to replace
the traditional, "cut-and-sew" Cox maze III procedure with lesion sets that are
simpler, shorter, and safer but just as effective. There is demand for technology
to make continuous, linear, transmural ablations reliably with a versatile energy
source via an epicardial approach. This would make minimally invasive endoscopic
surgical ablation of atrial fibrillation (AF) without cardiopulmonary bypass and
with a closed chest feasible. These advances would shorten cardio-pulmonary
bypass and improve outcomes in patients having surgical ablation and concomitant
cardiac surgery. This review summarizes the technology behind alternative energy
sources used to treat AF. Alternative energy sources include hypothermic sources
(cryoablation) and hyperthermic sources (radiofrequency, microwave, laser,
ultrasound). For each source, the biophysical background, mode of tissue injury,
factors affecting lesion size, and advantages and complications are discussed.
Lasers in clinical urology: state of the art and new horizons. Marks AJ, Teichman JM. World J Urol. 2007 Jun;25(3):227-33. Epub 2007 Mar 28.
We present an overview of current and emerging lasers for Urology. We begin with
an overview of the Holmium:YAG laser. The Ho:YAG laser is the gold standard
lithotripsy modality for endoscopic lithotripsy, and compares favorably to
standard electrocautery transurethral resection of the prostate for benign
prostatic hyperplasia (BPH). Available laser technologies currently being studied
include the frequency doubled double-pulse Nd:Yag (FREDDY) and high-powered
potassium-titanyl-phosphate (KTP) lasers. The FREDDY laser presents an affordable
and safe option for intracorporeal lithotripsy, but it does not fragment all
stone compositions, and does not have soft tissue applications. The high power
KTP laser shows promise in the ablative treatment of BPH. Initial experiments
with the Erbium:YAG laser show it has improved efficiency of lithotripsy and more
precise ablative and incisional properties compared to Ho:YAG, but the lack of
adequate optical fibers limits its use in Urology. Thulium:YAG fiber lasers have
also demonstrated tissue ablative and incision properties comparable to Ho:YAG.
Lastly, compact size, portability, and low maintenance schedules of fiber lasers
may allow them to shape the way lasers are used by urologists in the future.
Lasers and soft tissue: periodontal therapy. Parker S. Br Dent J. 2007 Mar 24;202(6):309-15.
Periodontology exists as a major specialty within clinical dentistry that has
developed through the extensive research carried out into all parameters
pertaining to a 'best practice' approach. With the advent of surgical lasers into
clinical dentistry, considerable interest has been shown in the possible benefits
that might be derived from the adjunctive effects of bacterial control and
haemostasis that are associated with laser use. Despite the number of
publications on the subject, there is still controversy over the use of lasers in
periodontology. The following paper will outline the procedures that have been
advocated for laser use and provide a review of the literature.
Comparison of adverse events of laser and light-assisted hair removal systems in skin types IV-VI. Breadon JY, Barnes CA. J Drugs Dermatol. 2007 Jan;6(1):40-6.
Photoepilation, utilizing lasers and noncoherent light sources, is designed to
irradiate as much of the follicular unit as possible, with melanin as the target
chromophore. Wavelength absorption should generate energy sufficient to heat and
destroy the hair follicle, while preserving the surrounding tissue. When
performing photoepilation on African-American skin (Fitzpatrick skin types IV-VI)
a greater risk of potential epidermal adverse events, such as dyspigmentation,
blistering, crusting, edema, and subsequent scarring, is possible. To reduce
epidermal melanin absorption of energy longer wavelengths are considered safer
for use on Fitzpatrick skin types IV to VI. This article reviews and compares the
reported incidences of adverse events in African-American skin, utilizing lasers
and noncoherent light sources for assisted hair removal.
The KTP-(greenlight-) laser--principles and experiences. Bachmann A, Ruszat R. Minim Invasive Ther Allied Technol. 2007;16(1):5-10.
The most recent advance in laser technology for transurethral prostatectomy is
represented by the KTP laser. A potassium-titanyl-phosphate-(KTP-) crystal
doubles the frequency of pulsed Neodymium: Yttrium-Aluminum-Garnet (Nd:YAG) laser
energy to a 532 nm wavelength, which is in the green electromagnetic spectrum
(Greenlight-laser) and is selectively absorbed by hemoglobin and not at all by
water. Reducing the wavelength leads to a completely different interaction
between laser beam and prostatic tissue. In contrast to the early clinical
experiences with the Nd:YAG lasers in which vaporization was observed as a
side-effect during the procedure, the new KTP laser offers an immediate and
efficient vaporization, leading to real tissue ablation. Because of the instant
and nearly complete absorption in blood, the depth in vascularized tissue such as
prostate is only 0.8 mm. The superficial coagulation prevents the large tissue
necrosis that is seen with the Nd:YAG laser, leading to long lasting irritative
symptoms due to sloughing of necrotic tissue. Initial experiences, made with a
60W KTP system, demonstrated that the procedure was as effective as conventional
transurethral resection of the prostate (TURP) with a lower intraoperative
complication rate. In order to speed up vaporization of the prostate laser power
has been increased to 80W. The 80W KTP laser combines the tissue debulking
properties of TURP and the favourable safety profile of laser surgery. With the
new 120W High Performance System, introduced in 2006, vaporization will become
more powerful and faster. Initial reports are awaited.
Percutaneous laser disc decompression for the treatment of lumbar disc herniation: a review. Goupille P, Mulleman D, Mammou S, Griffoul I, Valat JP. Semin Arthritis Rheum. 2007 Aug;37(1):20-30. Epub 2007 Mar 23.
BACKGROUND: Discontinuation of the marketing of chymodactin has reawakened
interest in other percutaneous techniques for treating lumbar disc herniation.
Developed in the 1980s, the concept of laser disc decompression is based on the
percutaneous introduction of an optical fiber into the intervertebral disc and
administering laser energy. The procedure allows for the vaporization of a small
amount of the nucleus pulposus and hence a reduction in the intradisc pressure
and relief of radicular pain. OBJECTIVES: To review of the literature and
summarize the technical modalities, mechanism, indications for, and results of
percutaneous laser disc decompression for treating lumbar disc herniation.
METHODS: We identified studies of percutaneous laser disc decompression published
between January 1980 and June 2006 in the MEDLINE, EMBASE, and Cochrane Library
databases. The search terms used were percutaneous laser disc decompression,
laser, and spine or lumbar, disc or disk. The articles underwent a stepwise
selection process on the basis of their title, abstract, and full text. RESULTS:
Experimental and clinical studies have investigated the modality of percutaneous
laser disc decompression, but no consensus exists on the type of laser to use,
the wavelength, duration of application, or appropriate energy applied. Studies
have evaluated the impact of different techniques on the amount of disc removed,
intradisc pressure, and damage to neighboring tissue. Several open studies have
been published, but their methodology and conclusions are questionable, and no
controlled study has been performed. CONCLUSIONS: Although the concept of laser
disc nucleotomy is appealing, this treatment cannot be considered validated for
disc herniation-associated radiculopathy resistant to medical treatment.
Laser- and light-based hair removal: an update. Goldberg DJ. Expert Rev Med Devices. 2007 Mar;4(2):253-60.
A variety of laser technologies are now able to successfully remove unwanted
hair. Successful removal is based on an understanding of laser physics and
appropriate wavelengths, pulse durations and cooling of the skin. Although ruby
lasers were among the first to be used, alexandrite, diode and neodymium-doped
yttrium aluminium garnet (Nd:YAG) lasers, as well as a variety of broad-spectrum
intense pulsed light sources, are currently more commonly used for the treatment
of unwanted hair. Darker skin types are more difficult to treat but can also be
treated. Complications can occur after laser hair removal but can be reduced
through an understanding of the fundamentals of laser removal. These
complications include the obvious, such as scarring and pigmentary changes, and
the not so obvious, such as reticulate erythema and uveitis. Laser hair removal
is now widely accepted as a successful approach to remove unwanted hair in both
men and women. The future will involve office-based laser and light source hair
removal, as well as a variety of laser and light-based home devices.
[Mitomycin C and excimer laser] [Article in Portuguese] Wallau AD, Leoratti MC, Campos M. Arq Bras Oftalmol. 2005 Nov-Dec;68(6):867-72.
Mitomycin C is an antimetabolite agent that blocks DNA and RNA replication and
protein synthesis. It has been used in several ophthalmologic areas, and recently
as a modulator of corneal wound healing in excimer laser surgeries. A single
application of mitomycin C during surface corneal photoablative surgery seems a
safe and efficient therapeutic option for eyes with corneal opacity and/or as
prophylaxis in eyes with high risk for corneal opacity development. The use of
this drug in photoablative surgery should be cautious until long-term safety
results have been reported. The present text presents a review about corneal
wound healing with the use of mitomycin C.
Photodynamic therapy and cancer: a brief sightseeing tour. Palumbo G. Expert Opin Drug Deliv. 2007 Mar;4(2):131-48.
Photodynamic therapy (PDT) combines a drug (a photosensitiser or photosensitising
agent) with a specific type of light to kill cancer cells. It is a minimally
invasive treatment, with great potential in malignant disease and premalignant
conditions. Following the administration of the photosensitiser, light of the
appropriate wavelength is directed onto the abnormal tissue where the drug has
preferentially accumulated. Upon light activation, the photosensitiser transfers
its excess energy to molecular oxygen to produce an excited state (i.e., the
highly reactive singlet oxygen) that causes oxidative damage at the site of its
generation. The energy transfer occurs either directly to oxygen or through an
indirect mechanism that requires the formation of intermediate radical species.
Many photosensitisers have been developed, but only a few have been approved for
therapy in humans. Basic research in model systems (animals, cell lines) has
unravelled some fundamental cellular processes involved in the cell response to
PDT. The exploitation of relevant molecular observations, the discovery and
introduction of new sensitisers, the progress in the light delivery systems and
light dosimetry are all concurring to the increase of PDT therapeutic efficacy.
However, this field has not yet reached maturity. This review briefly analyses
the relevant properties of most photosensitisers and their field of application.
Special attention is dedicated to the effects observed in model cancer systems;
speculation and suggestions of possible future research directions are also
[Laser treatment of wrinkles. Update] [Article in German] Borelli C. Hautarzt. 2007 Mar;58(3):210-5.
Prolonged exposure to UV-radiation induces a variety of visible skin changes such
as lentigines, actinic keratoses and solar elastosis. Laser skin resurfacing
using ablative lasers (CO(2) or Erbium:YAG) is a popular procedure to reduce
these marks and improve the aesthetic appearance of photoaged facial skin. Skin
resurfacing is defined as an ablation of the upper layers of facial skin.
Possible side effects are hyperpigmentation, hypopigmentation and, at worst,
scarring. The"down time" after the skin resurfacing procedure is about 7 to 10
days. This is the major drawback of resurfacing and the main reason why
subsurfacing/skin rejuvenation is becoming even more popular. The literature is
not clear on whether this newer approach is as effective as resurfacing.
Mechanisms of action and efficacy of argon laser trabeculoplasty and selective laser trabeculoplasty. Stein JD, Challa P. Curr Opin Ophthalmol. 2007 Mar;18(2):140-5.
PURPOSE OF REVIEW: Since the 1980s, laser trabeculoplasty has served as an
effective way to lower intraocular pressure in patients with primary or secondary
open angle glaucomas, both as an initial therapy or in conjunction with
hypotensive medications. This manuscript will describe the proposed mechanisms of
action of argon laser trabeculoplasty and selective laser trabeculoplasty, as
well as review current studies of the therapeutic effect of these interventions.
RECENT FINDINGS: The exact mechanisms by which argon laser and selective laser
trabeculoplasty lower intraocular pressure are not known. There are several
theories, however, and we discuss the three most common ones: the mechanical
theory, the cellular (biologic) theory, and the cell division theory. Since both
lasers are applied to the same tissue and produce similar results, they most
likely produce their effects in comparable ways. We also describe the results of
several studies comparing these devices. Most show them to be equally effective
at lowering intraocular pressure; however, there are a few circumstances when
selective laser trabeculoplasty may be a better option than argon laser
trabeculoplasty. SUMMARY: Argon laser and selective laser trabeculoplasty are
safe and effective procedures for lowering intraocular pressure. The results of
ongoing clinical trials will help further define their role in the management of
patients with open angle glaucoma.
Contemporary in vivo confocal microscopy of the living human cornea using white light and laser scanning techniques: a major review. Patel DV, McGhee CN. Clin Experiment Ophthalmol. 2007 Jan-Feb;35(1):71-88.
In vivo confocal imaging of the cornea has evolved exponentially over the last
few decades and it has increasingly emerged from the laboratory to be used in the
clinical setting in relation to inherited corneal diseases, corneal infections,
contact lens wear and the effects of corneal surgery. This evolution has led to
significant enhancement of our knowledge of the living cornea in both its
physiological and pathological states. A number of in vivo confocal microscope
devices using white, and more recently coherent, light sources have been
developed to provide non-invasive assessment of the corneal microstructure at a
lateral resolution of 1-2 microm. The fundamental principles of in vivo confocal
microscopy and the key differences between these devices are highlighted in this
review. By providing a systematic review of the extensive literature on the human
cornea, this perspective paper aims to provide an overview of how in vivo
confocal microscopy has contributed to our greater understanding of the human
cornea in health, in disease, and following surgery, with a particular emphasis
on quantitative data. The utility and limitations of available data are
highlighted as are possibilities for the future development of this innovative
Laser applications in oral surgery and implant dentistry. Deppe H, Horch HH. Lasers Med Sci. 2007 Nov;22(4):217-21. Epub 2007 Feb 1.
Lasers have been used for many years in oral surgery and implant dentistry. In
some indications, laser treatment has become state of the art as compared to
conventional techniques. This article is a comprehensive review of new laser
applications in oral surgery and implant dentistry. One of the most interesting
developments over the last years was the introduction of the 9.6-microm CO(2)
laser. It has been shown in the recent literature that the use of this new device
can preserve tissue with almost no adverse effects at the light microscopic
level. In contrast, modifications of approved CO(2) laser therapies of
premalignant lesions resulted in higher recurrence rates than the conventional
defocused laser technique. However, several studies indicate that other
wavelengths such as Nd-YAG (lambda = 1,064 nm) or diode lasers (lambda = 810 nm)
may be also of value in this field. In many other indications, the use of lasers
is still experimental. Intraoperatively used photodynamic therapy or peri-implant
care of ailing implants with the CO(2) laser seems to be more of value than
conventional methods. However, further studies are required to assess standard
protocols. Over the past years, research identified some new indications for
laser treatment in oral surgery and implant dentistry. Moreover, well-known laser
applications were defined as state of the art. Nevertheless, further studies are
required for laser treatment in oral surgery and implant dentistry.
Complementary techniques: laser capture microdissection--increasing specificity of gene expression profiling of cancer specimens. Esposito G. Adv Exp Med Biol. 2007;593:54-65.
Recent developments in sensitive genome characterization and quantitative gene
expression analyses that permit precise molecular genetic fingerprinting of
tumoral tissue are having a huge impact on cancer diagnostics. However, the
significance of the data obtained with these techniques strictly depends on the
composition of the biological sample to be analyzed and is greatly enhanced by
including a preprocessing step that allows the researcher to distinguish and
isolate selected cell populations from surrounding undesired material. This may
represent a remarkable problem: indeed, genomic and proteomic analysis in the
context of cancer investigation is susceptible to contamination by nonneoplastic
cells, which can mask some tumor-specific alterations. Moreover, the
heterogeneity of the tissues of a histological section, in which the cell
population of interest may constitute only a small fraction, can represent an
insurmountable difficulty for the use of quantitative techniques that absolutely
depend on genomic material strictly derived from the cells that require analysis.
This is obviously not possible if DNA or RNA is extracted from entire biopsies.
In the past, this obstacle was partially overcome by manual dissection from
slides with a needle or scalpel; however, this method is feasible only if there
is a clear demarcation between the tissue under consideration and its
surroundings and moreover, allows only an approximate separation of tissues. The
recent development of microdissection systems based on laser technology has
largely solved this important problem. Laser microdissection is a powerful tool
for the isolation of specific cell populations (or single cells) from stained
sections of both formalin-fixed, paraffin-embedded and frozen tissues, from cell
cultures and even of a single chromosome within a metaphase cell. Resulting
material is suitable for a wide range of downstream assays such LOH (loss of
heterozygosity) studies, gene expression analysis at the mRNA level and a variety
of proteomic approaches such as 2D gel analysis, reverse phase protein array and
SELDI protein profiling. This chapter describes the characteristics of the most
widely utilized laser microdissection systems and their current applications.
Mesopic vision following keratorefractive surgery. Kirkwood BJ. Insight. 2006 Jul-Sep;31(3):7-8.
Laser photocoagulation: ocular research and therapy in diabetic retinopathy. Graham CE, Binz N, Shen WY, Constable IJ, Rakoczy EP. Adv Exp Med Biol. 2006;572:195-200.
Physical characteristics of various lasers used in stapes surgery. Frenz M. Adv Otorhinolaryngol. 2007;65:237-49.
The invention of modern small-fenestra stapedotomy procedures using a piston-type
prosthesis resulted in a remarkable hearing improvement and at the same time in a
reduction of complications compared to conventionally performed stapedectomies.
These procedures, however, still contain unpredictable risks such as uncontrolled
stapes fracturing, luxation of the stapes or creating a floating footplate, which
all can cause hearing loss or even deafness. The worldwide use of the
small-fenestration techniques led to the observation that most cases of
sensorineural hearing loss occurring after surgery were due to intraoperative
trauma to the inner ear, most commonly during footplate manipulation. This led to
the use of lasers in otological surgery as a possible tool for precise noncontact
cutting of bone without any drill vibration. Today, argon, KTP, CO(2) and Er:YAG
lasers are clinically used in middle ear surgery. Each laser has its
characteristic interaction process with bone with its specific advantages and
disadvantages. Therefore, it is not surprising that there are conflicting and
controversially discussed experimental and clinical reports. The purpose of this
study was to comprehensively compare the physical processes underlying the
laser-tissue interaction of the different laser systems in view of safety and
efficacy in order to enhance the ability to perform safe minimally invasive
surgery on the stapes footplate.
New laser treatment approaches for benign prostatic hyperplasia. Fried NM. Curr Urol Rep. 2007 Jan;8(1):47-52.
The recent introduction of higher power 100 W holmium:yttrium-aluminum-garnet
(Ho:YAG) and 80 W potassium titanyl phosphate lasers for rapid incision and
vaporization of the prostate has resulted in renewed interest in the use of
lasers for treatment of benign prostatic hyperplasia (BPH). Although long-term
studies are still lacking, short-term results demonstrate that these procedures
are at least as safe and effective in relieving BPH symptoms as transurethral
resection of the prostate and may provide reduced morbidity. Other laser
techniques, such as interstitial laser coagulation and contact laser vaporization
of the prostate, have lost popularity due to complications with increased
catheterization time, irritative symptoms, and infection rates. Although Ho:YAG
laser enucleation of the prostate is more difficult to learn and a slower
procedure than potassium titanyl phosphate laser vaporization, the Ho:YAG laser
is currently the most proven laser technique for BPH treatment. This article
reviews the latest developments in laser treatment of BPH over the past 2 years
and provides a view toward the future of lasers in the treatment of BPH.
Minimally invasive approaches for diagnosis and treatment of early-stage breast cancer. Vlastos G, Verkooijen HM. Oncologist. 2007 Jan;12(1):1-10.
Breast cancer management has been evolving toward minimally invasive approaches.
Image-guided percutaneous biopsy techniques provide accurate histologic diagnosis
without the need for surgical biopsy. Breast conservation therapy has become the
treatment standard for early-stage breast cancer. Sentinel lymph node biopsy is a
new procedure that can predict axillary lymph node status without the need of
axillary lymph node dissection. The next challenge is to treat primary tumors
without surgery. For this purpose, several new minimally invasive procedures,
including radiofrequency ablation, interstitial laser ablation, focused
ultrasound ablation, and cryotherapy, are currently under development and may
offer effective tumor management and provide treatment options that are
psychologically and cosmetically more acceptable to the patients than are
traditional surgical therapies. In this review, we give an overview of minimally
invasive approaches for the diagnostic and therapeutic management of early-stage
Advances in small animal mesentery models for in vivo flow cytometry, dynamic microscopy, and drug screening. Galanzha EI, Tuchin VV, Zharov VP. World J Gastroenterol. 2007 Jan 14;13(2):192-218.
Using animal mesentery with intravital optical microscopy is a well-established
experimental model for studying blood and lymph microcirculation in vivo. Recent
advances in cell biology and optical techniques provide the basis for extending
this model for new applications, which should generate significantly improved
experimental data. This review summarizes the achievements in this specific area,
including in vivo label-free blood and lymph photothermal flow cytometry,
super-sensitive fluorescence image cytometry, light scattering and speckle flow
cytometry, microvessel dynamic microscopy, infrared (IR) angiography, and
high-speed imaging of individual cells in fast flow. The capabilities of these
techniques, using the rat mesentery model, were demonstrated in various studies;
e.g., real-time quantitative detection of circulating and migrating individual
blood and cancer cells, studies on vascular dynamics with a focus on lymphatics
under normal conditions and under different interventions (e.g. lasers, drugs,
nicotine), assessment of lymphatic disturbances from experimental lymphedema,
monitoring cell traffic between blood and lymph systems, and high-speed imaging
of cell transient deformability in flow. In particular, the obtained results
demonstrated that individual cell transportation in living organisms depends on
cell type (e.g., normal blood or leukemic cells), the cellos functional state
(e.g., live, apoptotic, or necrotic), and the functional status of the organism.
Possible future applications, including in vivo early diagnosis and prevention of
disease, monitoring immune response and apoptosis, chemo- and radio-sensitivity
tests, and drug screening, are also discussed.
Acne and PDT: new techniques with lasers and light sources. Gold MH. Lasers Med Sci. 2007 Jun;22(2):67-72. Epub 2007 Jan 16.
Acne vulgaris is one of the most common dermatologic disorders encountered in
everyday practice. Treatment options for this often psychologically scarring
disease are numerous and, for many individuals, provide relief from the disorder.
However, factors such as antibiotic resistance and slow onset of action from many
topical therapies have led researchers to seek out alternative therapies,
especially for those suffering from moderate to severe inflammatory acne
vulgaris. Lasers and light sources are finding increased usage in the treatment
of inflammatory acne vulgaris. Light sources including blue lights and intense
pulsed lights are becoming regular additions to routine medical management to
enhance the therapeutic response. Finally, photodynamic therapy may change many
of the acne vulgaris paradigms, as its place is being defined in the treatment of
moderate to severe inflammatory acne vulgaris. More and more clinical trials are
showing the effectiveness of 5-aminolevulinic acid and photodynamic therapy in
the treatment of moderate to severe inflammatory acne vulgaris.
Laser treatment of keloids and hypertrophic scars. Bouzari N, Davis SC, Nouri K. Int J Dermatol. 2007 Jan;46(1):80-8.
BACKGROUND: Lasers have been used in the treatment of hypertrophic scars and
keloids for more than 20 years. Different laser systems have been examined; among
them pulsed dye lasers are currently considered the laser of choice in these
settings. OBJECTIVES: The purpose of this study is to review the pertinent
literature and provide updated information on different laser therapies available
for treatment of keloids and hypertrophic scars. METHODS: A Medline literature
search was performed for relevant publications. RESULTS: In this review the
results of published studies in the treatment and prevention of hypertrophic
scars and keloids are presented. Suggested mechanisms of action are reviewed. A
review of the optimal laser parameters to modulate treatment outcome will be
discussed. Different lasers are effective in not only the treatment but also the
prevention of hypertrophic scars and keloids, among them PDL is more promising.
Most of the suggested theories are based on the selective photothermolysis in
which the light energy emitted from a vascular laser is absorbed by hemoglobin,
generating heat and leading to coagulation necrosis, neocollagenesis, collagen
fiber heating with dissociation of disulfide bonds and subsequent collagen fiber
realignment. CONCLUSION: The optimal laser is currently 585 nm PDL, although the
recent results of Q-switched 532 nm frequency-doubled Nd:YAG are promising. Early
use of lasers are beneficial, especially in those who are prone to develop these
[Nucleotide sequence variants of the glucocorticoid receptor gene and their significance in determining glucocorticoid sensitivity] [Article in Hungarian] Majnik J, Patócs A, Balogh K, Luczay A, Török D, Szabó V, Borgulya G, Gergics P, Szappanos A, Bertalan R, Belema B, Toke J, Sereg M, Nagy ZZ, Sólyom J, Tóth M, Gláz E, Rácz K, Németh J, Fekete G, Tulassay Z. Orv Hetil. 2006 Nov 5;147(44):2107-15.
Nucleotide sequence variants of the glucocorticoid receptor gene and their
significance in determining glucocorticoid sensitivity. The physiologic response
and sensitivity to glucocorticoids may significantly differ among species,
individuals, tissues and cell types. The variability of the effect of endogenous
and exogenous glucocorticoids is largely determined by genetic components, of
which the authors review the knowledge on the glucocorticoid receptor gene. The
authors describe the genomic and non-genomic pathways of receptor function, the
significance of isoforms produced during receptor protein formation, the
pathomechanism of glucocorticoid resistance syndrome and the results of clinical
investigations related to receptor gene polymorphisms. Through subtle alteration
of receptor function, the gene polymorphisms may increase or diminish sensitivity
to glucocorticoids and may play a role in the pathogenesis of metabolic
disorders. In their own studies the authors found, that the N363S polymorphism,
which increases glucocorticoid sensitivity, may play a role in the pathogenesis
of bilateral adrenal adenomas, it may modify the clinical phenotype of patients
with congenital adrenal hyperplasia, and may have an impact on steroid-induced
ocular hypertension. It is presumed that further research in other diseases will
continue to complete our knowledge on the pathophysiology of glucocorticoid
receptor gene polymorphisms.
Laser diffractometry as a technique for the rapid assessment of aerosol particle size from inhalers. Mitchell JP, Nagel MW, Nichols S, Nerbrink O. J Aerosol Med. 2006 Winter;19(4):409-33.
The rapid assessment of aerosols produced by medicinal inhalers is highly
desirable from several standpoints, including the assurance of product quality,
the development of new delivery systems, and the need to meet an increasing
requirement by regulatory bodies for reliable in vitro performance data. Particle
size analysis has traditionally been undertaken by cascade impactor on account of
the direct assessment of active pharmaceutical ingredient(s) (APIs) that is
possible by this method. However, laser diffractometry is less labor-intensive,
more rapid, and can be a less invasive procedure. The technique provides
meaningful results; as long as precautions are taken to validate that the
measurements are an accurate reflection of the distribution of API mass as a
function of particle or droplet size. We begin the review by examining the
underlying theory of the laser diffraction method. After a brief description of
current laser diffractometers used in inhaler measurements, we continue by
examining the range of applications by inhaler class. We then examine the basis
upon which inhaler measurements made by laser-diffractometry can be compared with
equivalent particle size distribution data from compendial techniques. We
conclude the assessment of the technique by developing guidelines for its valid
application as a component of the range of in vitro methods that are available
for inhaler performance assessment.
Combination therapies in oculofacial rejuvenation. Bosniak S, Cantisano-Zilkha M, Purewal BK, Zdinak LA. Orbit. 2006 Dec;25(4):319-26.
The oculo-facial surgeon's quest for non-invasive procedures is a response to
increasing patient demands for enhanced results without any downtime. Technology
has obliged us with multiple injectable and light therapeutic modalities that
tighten skin, relax and fill in wrinkles, and improve skin dyspigmentation and
texture. When these techniques are combined, the results are superior to the use
of individual therapies alone. The foundation for combination therapies are:
botulinum toxin, filling agents, chemical peels, intense pulsed light,
non-ablative and ablative lasers.
Review editorial comments. Mantz AW. Spectrochim Acta A Mol Biomol Spectrosc. 2007 May;67(1):1-3. Epub 2006 Nov 9.
Laser removal of pigmented and vascular lesions. Goldberg DJ. J Cosmet Dermatol. 2006 Sep;5(3):204-9.
Twenty years of laser dermatology has resulted in current technology which allows
variable spot sizes, different wavelengths, and a variety of effective cooling
devices. These developments have made the treatment of cutaneous pigmented and
vascular lesions safe and efficacious by targeting selected chromophores while
minimizing damage to the surrounding tissue. Vascular lesions are targeted by a
variety of wavelength lasers including the KTP (532 nm), pulsed dye (585-595 nm),
and the Nd:YAG (1064 nm) laser systems. Pigmented lesions may be treated with a
wide variety of lasers due to the broad absorption spectrum of melanin. Intense
pulsed light (IPL), with its widely adjustable parameters, has established itself
as a useful adjunctive for the treatment of a variety of pigmented and vascular
lesions. The purpose of this review article is to present the current treatment
options for the common aesthetic complaints of pigmented and vascular lesions.
[Lasers in urology] [Article in Spanish] Vicente Rodríguez J, Fernández González I, Hernández Fernández C, Santos García-Vaquero I, Rosales Bordes A. Actas Urol Esp. 2006 Oct;30(9):879-95.
The objective of this article is to quote under the form of a document the
opinions expressed by the participants of the round table "Lasers in Urology
Today" (january 2006). The material and method used is the compilation of
critical and updated notions on the usefulness of lasers in urology, supplemented
by bibliographic references, a limited iconography. The results achieved by
lasers today enable us to state that: Holmium laser is the choice treatment for
in situ lithotripsy; however, it has not significantly improved previous results
when treating urologic tumours and stenoses. Nowadays we have two types of
lasers: KTP and HoL, which obtain results similar to surgery regarding BPH, but
with reduced morbidity. The usefulness of laser in laparoscopic surgery is still
under development. CONCLUSION: Lasers in Urology Today play an active role in in
situ lithotripsy (HoL), and a competitive one in BPH surgery (KTP and HoL).
Regarding the rest of indications, i.e. tumours, stenoses, laparoscopic surgery,
etc., further studies and enough follow-up times are still needed.
Nonablative lasers. Nouri K, Rivas MP, Bouzari N, Faghih S. J Cosmet Dermatol. 2006 Jun;5(2):107-14.
The trend toward minimally invasive rejuvenation techniques has led to the
widespread use of nonablative lasers. Nonablative lasers can be classified in two
groups based on their wavelengths: lasers emitting light in the visible range,
and those emitting in the infrared range. In this review, different laser and
intense pulsed light (IPL) systems are presented and critically discussed along
with findings of the studies in the literature.
Lasers for scars: a review. Nouri K, Vidulich K, Rivas MP. J Cosmet Dermatol. 2006 Mar;5(1):14-22.
Many articles have been published on improving the appearance of scars; however,
there are no definitive management protocols. Our objective was to review the
literature on laser therapy for various types of scars. There are multiple laser
modalities that have been studied with certain features that may be indicated for
specific scar types. Suggestions are given for further studies.
Laser treatment for pigmented lesions: a review. Jones CE, Nouri K. J Cosmet Dermatol. 2006 Mar;5(1):9-13.
BACKGROUND: Just a few decades ago, before lasers were introduced into
dermatologic practice, many cutaneous lesions were untreatable. Since the
introduction of lasers in dermatology in the 1960s and its revolution by Anderson
and Parrish in the 1980s based on the selective photothermolysis theory, lasers
have become a main component of many dermatology practices. With the advent of
these selective lasers and their constant technological advancements, many
lesions can now be easily removed with a low incidence of complications, creating
a high demand for laser surgery. Aims This paper will review current laser
systems used for pigmented lesions. METHODS: An English-language literature
search and review through Medline from January 1994 to October 2004. Review of
the latest techniques and lasers used in treating pigmentary disorders and
possible future applications and treatment options. CONCLUSIONS: Laser technique
and technology has greatly advanced producing more effacious treatment with
Lasers, lights and related technologies: a review of recent journal highlights. Ee HL, Barlow RJ. Clin Exp Dermatol. 2007 Jan;32(1):135-7. Epub 2006 Nov 30.
Confocal laser endomicroscopy: technical status and current indications. Hoffman A, Goetz M, Vieth M, Galle PR, Neurath MF, Kiesslich R. Endoscopy. 2006 Dec;38(12):1275-83.
Confocal laser endomicroscopy is a newly introduced endoscopic tool that makes it
possible to carry out confocal microscopic examination of the mucosal layer
during ongoing endoscopy. Different types of tissue and diseases can be diagnosed
immediately, facilitating early diagnosis of gastrointestinal cancer. Analysis of
the in vivo microarchitecture is helpful in targeting biopsies to relevant areas.
In addition, subsurface imaging can unmask microscopic diseases - (microscopic
colitis) or bacterial infection ( HELICOBACTER PYLORI), for example. Molecular
imaging is becoming feasible, and this will shortly open the door to new
indications in gastrointestinal endoscopy (e.g., in vivo receptor analysis).
Laser treatment of rosacea. Laube S, Lanigan SW. J Cosmet Dermatol. 2002 Dec;1(4):188-95.
Rosacea is a common condition often resulting in persistent erythema and
telangiectasia as well as rhinophyma in a number of patients. Over the last two
decades lasers have been increasingly used in the treatment of these permanent
changes. The literature is reviewed in terms of the different laser systems,
side-effects and comparison with other surgical techniques. Laser studies on
rosacea-associated telangiectasia and erythema are limited. Copper-bromide,
krypton and KTP lasers have been used with good to excellent results. However,
the most commonly applied system is the flash lamp-pumped pulsed dye laser.
Rhinophyma can be treated with a variety of different surgical methods, including
laser resurfacing. CO(2) lasers are the most widely used lasers, others are the
Er:YAG and Nd:YAG lasers. Cosmetic end results are comparable to partial excision
with a scalpel or electrosurgery. There does not appear to be an increased risk
of infection or scarring, but the conventional surgical methods are quicker to
perform and more cost effective.
Excimer laser phototherapeutic keratectomy. Ayres BD, Rapuano CJ. Ocul Surf. 2006 Oct;4(4):196-206.
Anterior corneal pathology, such as corneal scars and corneal stromal
dystrophies, can be visually devastating. Over the past decade, there was a shift
in treatment of these conditions from corneal transplantation to phototherapeutic
keratectomy (PTK) using the 193 nm excimer laser for visual restoration. We have
reviewed the recent literature on techniques for performing and refining PTK and
also on various pathologic conditions that can be treated with PTK. The primary
indications for PTK include anterior corneal dystrophies, such as lattice,
granular, and Reis-Bückler's dystrophy. PTK can produce significant visual
improvement in these patients, and corneal transplantation or retransplantation
can be delayed. Corneal degenerations, such as Salzmann's nodular degeneration,
keratoconus nodules, and climatic droplet keratopathy, also can be successfully
treated with PTK. Additionally, anterior corneal scars from such etiologies as
trauma, corneal ulcers, and prior refractive surgery can have visual improvement
with PTK. In summary, PTK is a powerful tool for the management of anterior
corneal pathology. In a properly selected and well-counseled patient, PTK can
significantly improve vision and quality of life.
Intra-puff CO and CO2 measurements of cigarettes with iron oxide cigarette paper using quantum cascade laser spectroscopy. Crawford DR, Parrish ME, Gee DL, Harward CN. Spectrochim Acta A Mol Biomol Spectrosc. 2007 May;67(1):4-15. Epub 2006 Oct 25.
The objective of this research was to apply Fourier transform infrared
spectroscopy (FTIR) and tunable infrared laser differential absorption
spectroscopy (TILDAS) for measuring selected gaseous constituents in mainstream
(MS) and sidestream (SS) smoke for experimental cigarettes designed to reduce MS
CO using iron oxide cigarette papers. These two complimentary analytical
techniques are well suited for providing per puff smoke deliveries and intra-puff
evolution profiles in cigarette smoke respectively. The quad quantum cascade (QC)
laser high resolution infrared spectroscopy system has the necessary temporal and
spectral resolution and whole smoke analysis capabilities to provide detailed
information for CO and CO(2) as they are being formed in both MS and SS smoke.
The QC laser system has an optimal data rate of 20 Hz and a unique puffing
system, with a square wave shaped puff, that allows whole smoke to enter an 18 m,
0.3 L multi-pass gas cell in real time (0.1s cell response time) requiring no
syringe or Cambridge filter pad. Another similar multi-pass gas cell with a 36 m
pathlength simultaneously monitors the sidestream cigarette smoke. The smoke from
experimental cigarettes manufactured with two types of iron oxide papers were
compared to the smoke from cigarettes manufactured similarly without iron oxide
in the paper using both instrument systems. The delivery per puff determined by
the QC laser method agreed with FTIR results. MS CO intra-puff evolution profiles
for iron oxide prototype cigarettes demonstrated CO reduction when compared to
cigarettes without iron oxide paper. Additionally, both CO and CO(2) intra-puff
evolution profiles of the cigarettes with iron oxide paper showed a significant
reduction at the initial portion of the 2 s puff not observed in the non-iron
oxide prototype cigarettes. This effect also was observed for ammonia and
ethylene, suggesting that physical parameters such as paper porosity and burn
rate are important. The SS CO and CO(2) deliveries for the experimental
cigarettes evaluated remained unaffected. The iron oxide paper technology remains
under development and continues to be evaluated.
Measurement of acrolein and 1,3-butadiene in a single puff of cigarette smoke using lead-salt tunable diode laser infrared spectroscopy. Thweatt WD, Harward CN Sr, Parrish ME. Spectrochim Acta A Mol Biomol Spectrosc. 2007 May;67(1):16-24. Epub 2006 Oct 25.
Acrolein and 1,3-butadiene in cigarette smoke generally are measured using two
separate analytical methods, a carbonyl derivative HPLC method for acrolein and a
volatile organic compound (VOC) GC/MS method for 1,3-butadiene. However, a single
analytical method having improved sensitivity and real-time per puff measurement
will offer more specific information for evaluating experimental carbon filtered
cigarettes designed to reduce the smoke deliveries of these constituents. This
paper describes an infrared technique using two lead-salt tunable diode lasers
(TDLs) operating with liquid nitrogen cooling with emissions at 958.8 cm(-1) and
891.0 cm(-1) respectively for the simultaneous measurement of acrolein and
1,3-butadiene, respectively, in each puff of mainstream cigarette smoke in real
time. The dual TDL system uses a 3.1l volume, 100 m astigmatic multiple pass
absorption gas cell. Quantitation is based on a spectral fit that uses previously
determined infrared molecular line parameters generated in our laboratory,
including line positions, line strengths and nitrogen-broadened half-widths for
these species. Since acrolein and ethylene absorption lines overlap and
1,3-butadiene, ethylene and propylene absorption lines overlap, the per puff
deliveries of ethylene and propylene were determined since their overlapping
absorption lines must be taken into account by the spectral fit. The acrolein and
1,3-butadiene total cigarette deliveries for the 1R5F Kentucky Reference
cigarette were in agreement with the HPLC and GC/MS methods, respectively. The
limit of detection (LOD) for 1,3-butadiene and acrolein was 4 ng/puff and 24
ng/puff, respectively, which is more than adequate to determine at which puff
they break through the carbon filter. The retention and breakthrough behavior for
the two primary smoke constituents depend on the cigarette design and
characteristics of the carbon filter being evaluated.
LIF detection of peptides and proteins in CE. García-Campaña AM, Taverna M, Fabre H. Electrophoresis. 2007 Jan;28(1-2):208-32.
CE- and microchip-based separations coupled with LIF are powerful tools for the
separation, detection and determination of biomolecules. CE with certain
configurations has the potential to detect a small number of molecules or even a
single molecule, thanks to the high spatial coherence of the laser source which
permits the excitation of very small sample volumes with high efficiency. This
review article discusses the use of LIF detection for the analysis of peptides
and proteins in CE. The most common laser sources, basic instrumentation,
derivatization modes and set-ups are briefly presented and special attention is
paid to the different fluorogenic agents used for pre-, on- and postcapillary
derivatization of the functional groups of these compounds. A table summarizing
major applications of these derivatization reactions to the analysis of peptides
and proteins in CE-LIF and a bibliography with 184 references are provided which
covers papers published to the end of 2005.
Sub-5-fs real-time spectroscopy of transition states in bacteriorhodopsin during retinal isomerization. Kobayashi T, Yabushita A, Saito T, Ohtani H, Tsuda M. Photochem Photobiol. 2007 Mar-Apr;83(2):363-8.
By using a sub-5-fs visible laser pulse, we have made the first observation of
the vibrational spectra of the transition state during trans-cis isomerization in
the retinal chromophore of bacteriorhodopsin (bR(S68). No instant isomerization
of the retinal occurs in spite of electron promotion from the bonding pi-orbital
to the anti-bonding pi*-orbital. The difference between the in-plane and
out-of-plane vibrational frequencies (about 1150-1250 and 900-1000 cm(-1),
respectively) is reduced during the first time period. The vibrational spectra
after this period became very broad and weak and are ascribed to a "silent
state." The silent state lasts for 700-900 fs until the chromophore isomerizes to
the cis-C13 = C14 conformation. The frequency of the C = C stretching mode was
modulated by the torsion mode of the C13 = C14 double bond with a period of 200
fs. The modulation was clearly observed for four to five periods. Using the
empirical equation for the relation between bond length and stretching frequency,
we determined the transitional C = C bond length with about 0.01 angstroms
accuracy during the torsion motion around the double bond with 1-fs time
Treatment of severe male infertility by micromanipulation-assisted fertilization: an update. Tesarik J, Mendoza C. Front Biosci. 2007 Jan 1;12:105-14.
In the past 5-10 years the evolution of micromanipulation-assisted fertilization
for the treatment of severe male infertility was marked by the introduction of
new technical support, refinement of diagnostic methods for the evaluation of
sperm developmental potential, and development of new treatment regimens for the
newly discovered abnormalities. The new technical support involves the use of
non-contact laser technology to assist micromanipulation for fertilization, the
evolution of polarized microscopy-based optical systems to non-invasively detect
the position of the meiotic spindle in living human oocytes, and the development
of high-magnification optical systems for a better morphological selection of
spermatozoa to be used for fertilization. Diagnostic approaches were enriched by
commercial availability of kits for the analysis of sperm DNA integrity, leading
to the definition of sperm nuclear DNA damage as a distinct cause of male
infertility, and by the development of tests, based on heterologous ICSI, for
detection of sperm failure to activate oocytes. Several treatment options for
these conditions have been proposed and are currently being tested in
larger-scale trials. Some technical improvement was also achieved in the field of
in vitro maturation of germ cells from men with in vivo maturation arrest, but
only a modest clinical improvement resulted from their application. As to the
risk for the offspring, recent data are rather reassuring. Except for the risk of
transmission of genetically based infertility, no straightforward evidence for a
health risk derived from these techniques has been provided. Nevertheless,
caution is necessary, particularly concerning the eventual increase in
Treatment of verrucae vulgaris and molluscum contagiosum with photodynamic therapy. Gold MH, Moiin A. Dermatol Clin. 2007 Jan;25(1):75-80.
The use of 5-aminolevulinc acid photodynamic therapy in the treatment of
recalcitrant verrucae vulgaris and in the treatment of recalcitrant molluscum
contagiosum has been shown to substantially reduce the lesion count and severity.
Clinical research published in the medical literature and personal experience of
both of the authors support the use of 5-aminolevulinc acid photodynamic therapy
in appropriate individuals with recalcitrant verrucae vulgaris and molluscum
contagiosum lesions. This article reviews the medical literature and identifies
the various lasers and lights sources used to treat these conditions.
Aminolevulinic acid photodynamic therapy for actinic keratoses/actinic cheilitis/acne: vascular lasers. Alexiades-Armenakas M. Dermatol Clin. 2007 Jan;25(1):25-33.
The combination of newer laser and light sources, the long-pulsed pulsed dye
laser (LP PDL) and intense pulsed light, with topical aminolevulinic acid
photodynamic therapy (PDT) has achieved enhanced efficacy and rapid treatment and
recovery, while diminishing unwanted side effects. In particular, LP PDL PDT has
been shown to be safe and effective in the treatment of actinic keratoses,
actinic cheilitis, photodamage, and acne vulgaris with minimal discomfort, rapid
treatment and recovery, and excellent posttreatment cosmesis.
Facial rejuvenation and light: our personal experience. Trelles MA, Mordon S, Calderhead RG. Lasers Med Sci. 2007 Jun;22(2):93-9. Epub 2006 Nov 23.
The treatment of ageing skin remains a very hot topic, and many systems have been
reported as having varying degrees of success. Nonablative lasers were developed
to avoid the problematic and uncomfortable sequelae following laser ablative
resurfacing, and while there was no downtime, there was also poor patient
satisfaction. The same was true of the intense pulsed light systems. The use of
different modalities in various combinations was found to offer much better
results, however, such as a 595-nm pulsed dye laser followed by a 1,450-nm diode
laser, and so on, all used at subablative thresholds. The recent entry of blue
and infrared tunable plasma light and light-emitting diodes into the skin
rejuvenation arena has attracted a great deal of attention. The authors suggest
that no single modality can accomplish all the complex events required for
effective skin rejuvenation, suggest that combination phototherapy is the best
approach combined with an adjunctive epidermal care regimen, and demonstrate
their development of this methodology.
High-content screening: emerging hardware and software technologies. Lee S, Howell BJ. Methods Enzymol. 2006;414:468-83.
The field of high-content screening has flourished since 2000 with advancements
in automated fluorescence microscopy technologies, fluorescent labeling
techniques, and sophisticated image analysis software. Through the use of these
technologies, researchers can now monitor cellular and molecular events in
individual cells in vitro following drug treatment or RNAi and rapidly screen
compound and siRNA libraries. This chapter discusses current and next-generation
hardware and software features and capabilities.
Laser therapy of vascular lesions. Landthaler M, Hohenleutner U. Photodermatol Photoimmunol Photomed. 2006 Dec;22(6):324-32.
Since the first construction of a laser by Maiman in 1960 and the first clinical
application of a laser in the therapy of skin lesions by Leon Goldman, laser
therapy has become an important therapeutic modality in dermatology. Various
lasers can be used for the treatment of different vascular and non-vascular
lesions. According to our results, vascular lesions constitute the most important
indication for laser therapy in dermatology.
Evidence for superior efficacy and safety of LASIK over photorefractive keratectomy for correction of myopia. Shortt AJ, Bunce C, Allan BD. Ophthalmology. 2006 Nov;113(11):1897-908.
PURPOSE: To examine possible differences in efficacy and safety between LASIK and
photorefractive keratectomy (PRK) for correction of myopia. DESIGN:
Meta-analysis/systematic review. PARTICIPANTS: Patient data from previously
reported prospective randomized controlled trials (PRCTs) and a systematic review
of prospective case series in the Food and Drug Administration (FDA) clinical
trials database. METHODS: A comprehensive literature search was performed using
the Cochrane Collaboration methodology to identify PRCTs comparing LASIK and PRK
for correction of myopia. A meta-analysis was performed on the results of PRCTs.
In parallel, a systematic review of prospective data from FDA case series of
LASIK and PRK for correction of myopia was undertaken. MAIN OUTCOME MEASURES: Key
efficacy outcomes (uncorrected visual acuity [UCVA] > or = 20/20, +/-0.50
diopters [D] of the target mean refractive spherical equivalent) and safety
outcomes (loss of > or =2 lines of best spectacle-corrected visual acuity
[BSCVA], final BSCVA > or = 20/40, and final BSCVA < 20/25 where preoperative
BSCVA was > or =20/20). RESULTS: Seven PRCTs were identified comparing PRK (683
eyes) and LASIK (403 eyes) for correction of myopia. More LASIK patients achieved
UCVA > or = 20/20 at 6 months (odds ratio, random effects model [95% confidence
interval], 1.72 [1.14-2.58]; P = 0.009) and 12 months (1.78 [1.15-2.75], P =
0.01). Loss of > or =2 lines of BSCVA at 6 months was less frequent with LASIK
(2.69 [1.01-7.18], P = 0.05). Data from 14 LASIK (7810 eyes) and 10 PRK (4414
eyes) FDA laser approval case series showed that more LASIK patients achieved
UCVA of 20/20 or better at 12 months (1.15 [1.03-1.29], P = 0.01), significantly
more LASIK patients were within +/-0.50 D of target refraction at 6 months (1.38
[1.26-1.50], P<0.00001) and 12 months (1.21 [1.08-1.36], P = 0.0009) after
treatment, and loss of > or =2 lines of BSCVA at 6 months was less frequent with
LASIK (2.91 [2.22-3.83], P<0.00001). CONCLUSIONS: LASIK appears to have efficacy
and safety superior to those of PRK. However, the data examined are from studies
conducted > or =5 years ago. It is therefore unclear how our findings relate to
present-day methods and outcomes. Further trials comparing contemporary equipment
and techniques are needed to reevaluate the relative merits of these procedures.
Lasers, light sources, and radiofrequency devices for skin rejuvenation. Narurkar VA. Semin Cutan Med Surg. 2006 Sep;25(3):145-50.
Update on botulinum toxin. Flynn TC. Semin Cutan Med Surg. 2006 Sep;25(3):115-21.
Botulinum toxin for facial enhancement is currently the most popular aesthetic
procedure performed in the United States. New developments have occurred within
the last few years. Patients prefer having multiple areas of the upper face
treated which increases patient satisfaction. Treatment of the forehead is now
being accomplished with fewer units of botulinum toxin. This helps preserve the
natural look of some movement of the forehead. Men require more units of
botulinum toxin than women. Combination therapy using botulinum toxin along with
lasers or filler substances is ideal. Aesthetic medicine knowledge has
progressed, contributing a greater understanding of botulinum treatment for
advanced areas of the face. The orbicularis oris, mentalis, and depressor anguli
oris are now routinely treated and help improve overall facial appearance. Other
forms of botulinum toxins (additional type A or type B toxins) are available,
each with advantages and disadvantages.
Laser and photoepilation for unwanted hair growth. Haedersdal M, Gøtzsche PC. Cochrane Database Syst Rev. 2006 Oct 18;(4):CD004684.
BACKGROUND: Unwanted hair growth is a therapeutic challenge and considerable
resources are spent to achieve a hair-free appearance. Epilation with laser
devices (alexandrite, diode, neodymium:YAG, and ruby lasers) and intense pulsed
light are commonly used although the long-term effect is uncertain. OBJECTIVES:
To assess the effects of epilation with lasers and light sources. SEARCH
STRATEGY: We searched the Cochrane Skin Group’s Specialised Register in February
2004; MEDLINE (from 1966) and EMBASE (from 1980) in April 2005. We searched
reference lists of collected trials and contacted trial authors. SELECTION
CRITERIA: Randomised controlled trials of laser or photoepilation. DATA
COLLECTION AND ANALYSIS: Primary outcomes were objective reduction in hair
counts, adverse effects and subjective reduction in hairiness. Secondary outcomes
were participants satisfaction and personal observations such as softer, finer,
or paler hairs. Two authors independently extracted data and assessed trial
quality. MAIN RESULTS: We included eleven randomised controlled trials involving
444 people, none of which were of high methodological quality. A large number of
trials were excluded, mainly because of their non-randomised design. The
randomisation procedures were either unclear or inadequate, using coin tossing,
alternation, drawing lots or cards, or open tables of random numbers. The
interventions and outcomes were too heterogeneous to be entered in a
meta-analysis. Most trials examined a short-term effect up to six months after
final treatment. There appeared to be a short-term effect of approximately 50%
hair reduction with alexandrite and diode lasers up to six months after
treatment, whereas little evidence was obtained for an effect of intense pulsed
light, neodymium:YAG or ruby lasers. Long-term hair removal was not documented
with any treatment. Pain, skin redness, swelling, burned hairs and pigmentary
changes were infrequently reported adverse effects. AUTHORS’ CONCLUSIONS: Some
treatments lead to temporary short-term hair removal. High quality research is
needed on the effect of laser and photoepilation.
Merger of laser capture microdissection and mass spectrometry: a window into the amyloid plaque proteome. Gozal YM, Cheng D, Duong DM, Lah JJ, Levey AI, Peng J. Methods Enzymol. 2006;412:77-93.
The occurrence of protein accumulation and aggregation in the brain is one of the
pathological hallmarks of neurodegenerative diseases such as Alzheimer’s disease
(AD). Although it is instructive to analyze the aggregated proteins in the brain,
biochemical purification and identification of these proteins have been
challenging. Recent developments in laser capture microdissection (LCM) and mass
spectrometry (MS) enable large-scale protein profiling of captured tissue
samples. We present here the method of analyzing senile plaques from postmortem
AD brains by coupling LCM and highly sensitive liquid chromatography-tandem mass
spectrometry (LC-MS/MS). First, the senile plaques were stained with thioflavin-S
and precisely isolated by adjusted laser beams under a microscope. Total proteins
in the isolated tissues were extracted and resolved on an SDS gel. To identify
all proteins in the samples, the gel was excised into multiple pieces followed by
trypsin digestion. The resulting peptides were further separated by reverse-phase
chromatography and analyzed by tandem mass spectrometry. A database search of
acquired MS/MS spectra allowed the identification of hundreds to thousands of
peptides/proteins in the original samples. Moreover, quantitative comparison of
protein composites in different LCM samples could be achieved by MS strategies.
For instance, the comparison between plaques and surrounding nonplaque tissues
from the same specimen revealed tens of proteins specifically enriched in the
plaques. Finally, the data were corroborated by independent experiments using the
approach of immunohistochemistry. Taken together, the merger of LCM and MS is a
powerful tool to probe the proteome of any given pathological lesions.
The design of single particle laser mass spectrometers. Murphy DM. Mass Spectrom Rev. 2007 Mar-Apr;26(2):150-65.
This review explores some of the design choices made with single particle mass
spectrometers. Different instruments have used various configurations of inlets,
particle sizing techniques, ionization lasers, mass spectrometers, and other
components. Systematic bias against non-spherical particles probably exceeds a
factor of 2 for all instruments. An ionization laser tradeoff is the relatively
poor beam quality and reliability of an excimer laser versus the longer
wavelengths and slower response time of an Nd-YAG laser. Single particle
instruments can make special demands on the speed and dynamic range of the mass
spectrometers. This review explains some of the choices made for instruments that
were developed for different types of measurements in the atmosphere. Some
practical design notes are also given from the author’s experience with each
section of the instrument. Published 2006 Wiley Periodicals, Inc.
Determination of thermodynamics and kinetics of RNA reactions by force. Tinoco I Jr, Li PT, Bustamante C. Q Rev Biophys. 2006 Nov;39(4):325-60. Epub 2006 Oct 16.
Single-molecule methods have made it possible to apply force to an individual RNA
molecule. Two beads are attached to the RNA; one is on a micropipette, the other
is in a laser trap. The force on the RNA and the distance between the beads are
measured. Force can change the equilibrium and the rate of any reaction in which
the product has a different extension from the reactant. This review describes
use of laser tweezers to measure thermodynamics and kinetics of
unfolding/refolding RNA. For a reversible reaction the work directly provides the
free energy; for irreversible reactions the free energy is obtained from the
distribution of work values. The rate constants for the folding and unfolding
reactions can be measured by several methods. The effect of pulling rate on the
distribution of force-unfolding values leads to rate constants for unfolding.
Hopping of the RNA between folded and unfolded states at constant force provides
both unfolding and folding rates. Force-jumps and force-drops, similar to the
temperature jump method, provide direct measurement of reaction rates over a wide
range of forces. The advantages of applying force and using single-molecule
methods are discussed. These methods, for example, allow reactions to be studied
in non-denaturing solvents at physiological temperatures; they also simplify
analysis of kinetic mechanisms because only one intermediate at a time is
present. Unfolding of RNA in biological cells by helicases, or ribosomes, has
similarities to unfolding by force.
[Application of laser capture microdissection in plant genomic research] [Article in Chinese] Cai MH, Hu YK, Li YX, Yan YM. Yi Chuan. 2006 Oct;28(10):1325-9.
To a large degree, the growth and development of plants depend on the organ
and/or cell type-specific expression of genes. However, it can be difficult to
obtain sufficient number of specific cells from any developmental stage to
analyze expression of genes. Laser capture microdissection (LCM) is a novel
technique that allows us to collect pure targeted cell subgroup or even a single
cell quickly and precisely, thus the problem of tissue heterogeneity in molecular
analysis can be resolved successfully. In this paper, the principles of LCM were
introduced and the application of LCM in plant was summarized in gene expression
analysis, proteomics and plant-microbe interaction. Meanwhile, possible
directions of LCM in plant were put forward.
Photochemistry on metal nanoparticles. Watanabe K, Menzel D, Nilius N, Freund HJ. Chem Rev. 2006 Oct;106(10):4301-20.
Coherent vibrations of adsorbates induced by femtosecond laser excitation. Matsumoto Y, Watanabe K. Chem Rev. 2006 Oct;106(10):4234-60.
[Two-photon laser scanning fluorescence microscopy for functional cellular imaging: Advantages and challenges or One photon is good... but two is better!] [Article in French] Dufour P, Dufour S, Castonguay A, McCarthy N, De Koninck Y. Med Sci (Paris). 2006 Oct;22(10):837-44.
One of the main challenges of modern biochemistry and cell biology is to be able
to observe molecular dynamics in their functional context, i.e. in live cells in
situ. Thus, being able to track ongoing molecular events with maximal spatial and
temporal resolution (within subcellular compartments), while minimizing
interference with tissue biology, is key to future developments for in situ
imaging. The recent use of non-linear optics approaches in tissue microscopy,
made possible in large part by the availability of femtosecond pulse lasers, has
allowed major advances on this front that would not have been possible with
conventional linear microscopy techniques. Of these approaches, the one that has
generated most advances to date is two-photon laser scanning fluorescence
microscopy. While this approach does not really provide improved resolution over
linear microscopy in non absorbing media, it allows us to exploit a window of low
absorbance in live tissue in the near infrared range. The end result is much
improved tissue penetration, minimizing unwanted excitation outside the focal
area, which yields an effective improvement in resolution and sensitivity. The
optical system is also simplified and, more importantly, phototoxicity is
reduced. These advantages are at the source of the success of two-photon
microscopy for functional cellular imaging in situ. Yet, we still face further
challenges, reaching the limits of resolution that conventional optics can offer.
Here we review some recent advances in optics/photonics approaches that hold
promises to improve our ability to probe the tissue in finer areas, at faster
speed, and deeper into the tissue. These include super-resolution techniques,
introduction of non paraxial optics in microscopy and use of amplified
femtosecond lasers, yielding enhanced spatial and temporal resolution as well as
Pigmentary disorders in Asian skin: treatment with laser and intense pulsed light sources. Lin JY, Chan HH. Skin Therapy Lett. 2006 Oct;11(8):8-11.
The development of selective photothermolysis has enabled removal of targets such
as melanin. Both lasers and intense pulsed light (IPL) sources have been used in
the treatment of pigmented lesions, however careful selection is important to
ensure success. This is especially true in darker skinned individuals where the
risk of postinflammatory hyperpigmentation (PIH) is high. The advent of the
Q-switched laser, IPL, and now fractional photothermolysis (Fraxel, Reliant
Technologies) offers a variety of ways to treat epidermal and dermal pigmentary
Risks of occupational exposure to optical radiation. Sliney DH. Med Lav. 2006 Mar-Apr;97(2):215-20.
During the past 40 years a wide body of biomedical research has been conducted to
understand the factors which influence injury to optical radiation-particularly
with respect to the eye. A primary motivation for much of this research has been
the advent of lasers, since focal damage of the retina from a collimated beam
exposure is possible at some distance. A wide range of research studies provided
the basis for establishing human exposure limits for ultraviolet and infrared
radiation as well as for intense visible light. The International Commission on
Non-Ionizing Radiation Protection (ICNIRP) has published guidelines for human
exposure, and these are available at no cost from the ICNIRP website (http://www.
icnirp.org). Laser Maximum Permissible Exposure (MPE) limits used in
international safety standards, such as those of the International
Electrotechnical Commission (IEC) are based upon ICNIRP guidelines. Practical
laser safety standards and regulations have evolved to promote the safe design
and use of laser products. As a result of newer laser applications and increased
knowledge of the biological effects, MPEs have been revised a number of times.
Despite the existence of safety standards and regulations, accidental eye
injuries from lasers still occur. Accidental exposure to welding arcs and intense
lights occur more fequently, but the consequential loss of vision is much less,
with permanent effects rare. Accidental human exposure information also adds to
our understanding of ultraviolet, blue-light and laser induced retinal injury.
Accidents are most frequently attributed to the lack of understanding of hazards
and a failure to follow established safe work practices.
Laser-assisted microdissection (LAM) in developmental biology. Chimge NO, Ruddle F, Bayarsaihan D. J Exp Zoolog B Mol Dev Evol. 2007 Mar 15;308(2):113-8.
The analysis of gene expression in developing organs is a valuable tool for the
assessment of genetic fingerprints during the various stages of differentiation.
Complex processes in developing tissues are particularly difficult to understand
in terms of biochemical phenomena. Laser-assisted microdissection (LAM) allows
the efficient and precise capture of cells or groups of cells from developing
tissues in sufficient quantities and within the context of time and space to
permit the subsequent molecular characterization of the targeted tissue. The
technique development has dramatically increased the ease of isolating specific
cells which, together with progress in tissue preparation and microextraction
protocols, allows for broad-range down-stream applications in the fields of
genomics, transcriptomics and proteomics. This review gives an overview of the
LAM technology and its application in developmental biology. (c) 2006 Wiley-Liss,
Nonablative skin resurfacing: the role of PDT. Ruiz-Rodriguez R, López-Rodriguez L. J Drugs Dermatol. 2006 Sep;5(8):756-62.
As demand for less invasive, highly effective cosmetic procedures grows,
dermatologists must continue to explore and develop new treatment options.
Nonablative skin resurfacing techniques offer an effective and noninvasive
treatment for photorejuvenation. Several studies have shown improvement of
photodamaged skin and increased collagen production after nonablative treatments
using vascular lasers, mid-infrared lasers, intense pulsed light, radiofrequency
devices, fractional resurfacing, and plasma skin rejuvenation. Among the novel
methods for maximizing the efficacy of nonablative treatment is the concurrent
use of a photosensitizing agent. The light sources currently most used for
photodynamic rejuvenation are intense pulsed light and pulsed dye laser. We
present some preliminary results on rejuvenation using Metvix and red light. We
are still far from a thorough understanding of the molecular mechanism of
rejuvenation with this technique, although a nonspecific immune response could be
involved. Understanding the laser-tissue interactions associated with
photodynamic therapy is crucial in selecting patients that will most likely
Treatment of cellulite with optical devices: an overview with practical considerations. Alster TS, Tehrani M. Lasers Surg Med. 2006 Sep;38(8):727-30.
Cellulite is a common condition in women for which treatment is frequently
requested. Its etiology is unknown, but a myriad of factors including genetics,
hormones, and inflammation appear to contribute to its formation. Despite the
popularity of therapies touting their effectiveness for this pervasive condition,
few have proven long-lasting benefits. Lasers and light sources are the latest
devices to have entered the cellulite therapeutic market. This paper describes
these optical devices and provides an overview of their published effectiveness.
(c) 2006 Wiley-Liss, Inc.
New developments in radiochromic film dosimetry. Soares CG. Radiat Prot Dosimetry. 2006;120(1-4):100-6.
NIST has been a pioneer in the use of radiochromic film for medical dosimetry
applications. Beginning in 1988 with experiments with (90)Sr/Y ophthalmic
applicators, this work has continued into the present. A review of the latest
applications is presented, which include high activity low-energy photon source
dosimetry and ultra-high resolution film densitometry for dose enhancement near
stents and microbeam radiation therapy dosimetry. An exciting recent development
is the availability of a new radiochromic emulsion which has been developed for
IMRT dosimetry. This emulsion is an order of magnitude more sensitive than was
previously available. Measurements of the sensitivity and uniformity of samples
of this new film are reported, using a spectrophotometer and two scanning laser
densitometers. A unique feature of the new emulsion is that the peak of the
absorbance spectrum falls at the wavelength of the HeNe lasers used in the
densitometer, maximising sensitivity. When read at a wavelength of 633 nm,
sensitivities on the order of 900 mAU Gy(-1) were determined for this new film
type, compared with about 40 mAU Gy(-1) for type HS film, 20 mAU Gy(-1) for type
MD-55-2 film, and 3 mAU Gy(-1) for type HD-810. Film uniformities were found to
be good, on the order of 6% peak to peak. However, there is a strong polarisation
effect in the samples examined, requiring care in film orientation during
Past, present, and future: vascular lasers/light devices. Bucci J, Goldberg D. J Cosmet Laser Ther. 2006 Sep;8(3):149-53.
Vascular lasers were among the first available cutaneous light-based
technologies. The past 20 years has seen a variety of safe and effective laser
and light-based vascular treatment devices. This article provides a review of the
medical and scientific literature, which concludes that newer lasers have led to
increasing success and safety in the treatment of cutaneous vascular lesions.
Managing acne vulgaris effectively. Goodman G. Aust Fam Physician. 2006 Sep;35(9):705-9.
The management of acne is a gratifying experience. Available treatments are
effective, relatively nontoxic and generally safe. However, there is no quick
fix. Antibiotics, hormone therapies and topical therapies are maintenance
treatments. Isotretinoin can induce remission, as can some of the newer physical
modalities of lights, lasers and radiofrequency devices. Effective management of
acne often requires using a combination of treatments that act on different parts
of the pathogenic process of acne development.
Avoiding and treating dermal filler complications. Lemperle G, Rullan PP, Gauthier-Hazan N. Plast Reconstr Surg. 2006 Sep;118(3 Suppl):92S-107S.
All fillers are associated with the risk of both early and late complications.
Early side effects such as swelling, redness, and bruising occur after
intradermal or subdermal injections. The patient has to be aware of and accept
these risks. Adverse events that last longer than 2 weeks can be attributable to
technical shortcomings (e.g., too superficial an implantation of a long-lasting
filler substance). Such adverse events can be treated with intradermal
5-fluorouracil, steroid injections, vascular lasers, or intense pulsed light, and
later with dermabrasion or shaving. Late adverse events also include immunologic
phenomena such as late-onset allergy and nonallergic foreign body granuloma. Both
react well to intralesional steroid injections, which often have to be repeated
to establish the right dose. Surgical excisions shall remain the last option and
are indicated for hard lumps in the lips and visible hard nodules or hard
granuloma in the subcutaneous fat.
Laser in dermatology. Boord M. Clin Tech Small Anim Pract. 2006 Aug;21(3):145-9.
The laser is a tool that will augment the surgical techniques available to the
veterinarian. When using the laser compared with traditional surgery there are
multiple procedures that can be performed with much greater ease, and some
procedures that previously could not be performed. Specialty and academic
practices have used lasers for photodynamic therapy, lithotripsy of urinary
calculi, and percutaneous disk ablation. This article will focus on the lasers
use in dermatology. It is essential that the surgeon learn the basics of laser
physics, how the laser interacts with tissue and the safety issues one needs to
consider during its use. On deciding to use the laser the surgical techniques
chosen should always be based on considering the advantages and disadvantages the
laser has to offer. The use of biomedical lasers is a “cutting edge” technique
now available to our veterinary field.
New techniques in linear and non-linear laser optics in muscle research. Vanzi F, Capitanio M, Sacconi L, Stringari C, Cicchi R, Canepari M, Maffei M, Piroddi N, Poggesi C, Nucciotti V, Linari M, Piazzesi G, Tesi C, Antolini R, Lombardi V, Bottinelli R, Pavone FS. J Muscle Res Cell Motil. 2006;27(5-7):469-79. Epub 2006 Aug 24.
This review proposes a brief summary of two applications of lasers to muscle
research. The first application (laser tweezers), is now a well-established
technique in the field, adopted by several laboratories in the world and
producing a constant stream of original data, fundamental for our improved
understanding of muscle contraction at the level of detail that only single
molecule measurements can provide. As an example of the power of this technique,
here we focus on some recent results, revealing the performance of the working
stroke in at least two distinct steps also in skeletal muscle myosin. A second
laser-based technique described here is second-harmonic generation; the
application of this technique to muscle research is very recent. We describe the
main results obtained thus far in this area and the potentially remarkable impact
that this technology may have in muscle research.
Surface ablation over LASIK flaps. Trattler W, Salz JJ. Int Ophthalmol Clin. 2006 Summer;46(3):117-22.
Tattoos: a review of tattoo practices and potential treatment options for removal. Sweeney SM. Curr Opin Pediatr. 2006 Aug;18(4):391-5.
PURPOSE OF REVIEW: The purpose of this review is to present an overview of tattoo
practices, complications and treatment options relevant to the pediatric
population. RECENT FINDINGS: Tattoos are popular among adolescents for a variety
of reasons and may be associated with other high-risk behaviors. Research
indicates that adolescents may not comprehend potential health risks and
complications that are related to tattooing. Case reports of infection,
tattoo-associated dermatoses, and allergic reactions to tattoos continue to be
reported in the literature. Additional cases of allergic contact dermatitis are
being reported with temporary henna tattooing and cosmetic tattoos. As the desire
for tattoo removal increases, researchers continue to explore safe, innovative
and efficacious methods of tattoo removal. SUMMARY: As the popularity of
tattooing continues to rise, so do the potential complications and adverse
effects. Treatment options for tattoos are well described and must be
individualized to each patient. Lasers continue to be a reliable and efficacious
tool in treating amateur, professional, cosmetic and traumatic tattoos.
Adverse events associated with nonablative cutaneous visible and infrared laser treatment. Handley JM. J Am Acad Dermatol. 2006 Sep;55(3):482-9.
Since the theory of selective thermolysis was developed in the early 1980s, there
have been numerous advances in both laser technology and the understanding of
laser-tissue interaction. Nonablative dermatologic treatments involving laser
light continue to be increasingly used for a number of diverse applications such
as skin remodeling, the treatment of cutaneous melanocytic and vascular lesions,
and the removal of undesired hair and tattoo pigment. Although these techniques
are regarded as safe, both temporary and permanent adverse reactions do occur,
many of which are thermally mediated. Little has been published on the frequency
of adverse events in nonablative cutaneous laser treatments, or on the
comparative efficacy of the various strategies commonly used to minimize them.
Through reviewing relevant publications from the last 5 years, this article will
address both these issues.
Hemostatic techniques during laparoscopic partial nephrectomy. Walters RC, Collins MM, L’Esperance JO. Curr Opin Urol. 2006 Sep;16(5):327-31.
PURPOSE OF REVIEW: To review the current techniques and technologies being used
for hemostatic control during laparoscopic partial nephrectomy. RECENT FINDINGS:
Laparoscopic nephron-sparing surgery has become more common for the treatment of
renal masses. With increasing experience, the indications for nephron sparing are
increasing. Despite the increased use of these techniques in high-volume centers,
however, more widespread application has been limited because of the need for
advanced laparoscopic skills including the laparoscopic control of intraoperative
renal bleeding. As a result, many techniques have been developed to achieve
hemostasis, including conventional suture repair, tissue sealants, radiofrequency
ablation, lasers, water dissection, and microwave tissue coagulation. SUMMARY:
Laparoscopic partial nephrectomy is a technically challenging procedure. Many
promising techniques are being developed currently, most geared toward improved
hemostasis and collecting system repair. These techniques and products have made,
and will continue to make, the procedure less demanding and more universally
Caries detection and diagnosis: novel technologies. Pretty IA. J Dent. 2006 Nov;34(10):727-39. Epub 2006 Aug 9.
Recent years have seen an increase in research activity surrounding diagnostic
methods, particularly in the assessment of early caries lesions. The drive for
this has come from two disparate directions. The first is from the dentifrice
industry who are keen to develop techniques that would permit caries clinical
trials (CCTs) to be reduced in duration and subject numbers to permit the
investigation of novel new anti-caries actives. The second is from clinicians
who, armed with the therapies to remineralise early lesions are now seeking
methods to reliably detect such demineralised areas and implement true
preventative dentistry. This review examines novel technologies and the research
supporting their use. Techniques based on visual, optical, radiographic and some
emerging technologies are discussed. Each have their benefits although systems
based on the auto-fluorescence (such as QLF) of teeth and electrical resistance
(such as ECM) seem to offer the most hope for achieving reliable, accurate
detection of the earliest stages of enamel demineralisation.
Bioptics: where do things stand? Leccisotti A. Curr Opin Ophthalmol. 2006 Aug;17(4):399-405.
PURPOSE OF REVIEW: Bioptics treats complex refractive errors by combining
refractive techniques with different mechanisms of action, usually using an
intraocular implant (a phakic or pseudophakic intraocular lens) followed by a
corneal procedure (laser ablation, intrastromal implant). RECENT FINDINGS: In
myopia and hyperopia, bioptics with phakic intraocular lenses or refractive lens
exchange and subsequent excimer laser yields improved predictability and
unchanged safety, compared with sole intraocular lens surgery. Complications are
related mainly to intraocular lenses. In keratoconus and pellucid marginal
degeneration, intracorneal rings have been successfully combined with
phacoemulsification or with phakic intraocular lenses in a limited number of
eyes. In the author’s series, angle-supported phakic intraocular lenses were
implanted in 12 eyes to correct a mean regression of -8 D after excimer laser
(reverse bioptics), achieving a mean spherical equivalent of -0.3 D, mean best
spectacle-corrected visual acuity of 0.7, and mean uncorrected visual acuity of
0.5, with 83% of eyes within 0.5 D of spherical equivalent. SUMMARY: Bioptics
improves vision and halos and adds no particular risks to phakic or pseudophakic
intraocular lens implantation in either myopia or hyperopia. Reverse bioptics,
with phakic intraocular lenses or refractive lens exchange, can be used to
correct regressed corneal surgery.
Advances in time-resolved approaches to characterize the dynamical nature of enzymatic catalysis. Callender R, Dyer RB. Chem Rev. 2006 Aug;106(8):3031-42.
Jet-based methods to print living cells. Ringeisen BR, Othon CM, Barron JA, Young D, Spargo BJ. Biotechnol J. 2006 Sep;1(9):930-48.
Cell printing has been popularized over the past few years as a revolutionary
advance in tissue engineering has potentially enabled heterogeneous 3-D scaffolds
to be built cell-by-cell. This review article summarizes the state-of-the-art
cell printing techniques that utilize fluid jetting phenomena to deposit 2- and
3-D patterns of living eukaryotic cells. There are four distinct categories of
jetbased approaches to printing cells. Laser guidance direct write (LG DW) was
the first reported technique to print viable cells by forming patterns of
embryonic-chick spinal-cord cells on a glass slide (1999). Shortly after this,
modified laser-induced forward transfer techniques (LIFT) and modified ink jet
printers were also used to print viable cells, followed by the most recent
demonstration using an electrohydrodynamic jetting (EHDJ) method. The low cost of
some of these printing technologies has spurred debate as to whether they could
be used on a large scale to manufacture tissue and possibly even whole organs.
This review summarizes the published results of these cell printers (cell
viability, retained genotype and phenotype), and also includes a physical
description of the various jetting processes with a discussion of the stresses
and forces that may be encountered by cells during printing. We conclude the
review by comparing and contrasting the different jet-based techniques, while
providing a map for future experiments that could lead to significant advances in
the field of tissue engineering.
Are the processes reflected by late and ultra-late laser evoked potentials specific of nociception? Mouraux A, Plaghki L. Suppl Clin Neurophysiol. 2006;59:197-204.
Event-related components of laser evoked potentials (LEPs) in pain stimulation: recognition of infrequency, location, and intensity of pain. Kanda M. Suppl Clin Neurophysiol. 2006;59:61-6.
Cell delivery in regenerative medicine: the cell sheet engineering approach. Yang J, Yamato M, Nishida K, Ohki T, Kanzaki M, Sekine H, Shimizu T, Okano T. J Control Release. 2006 Nov 28;116(2):193-203. Epub 2006 Jun 27.
Recently, cell-based therapies have developed as a foundation for regenerative
medicine. General approaches for cell delivery have thus far involved the use of
direct injection of single cell suspensions into the target tissues.
Additionally, tissue engineering with the general paradigm of seeding cells into
biodegradable scaffolds has also evolved as a method for the reconstruction of
various tissues and organs. With success in clinical trials, regenerative
therapies using these approaches have therefore garnered significant interest and
attention. As a novel alternative, we have developed cell sheet engineering using
temperature-responsive culture dishes, which allows for the non-invasive harvest
of cultured cells as intact sheets along with their deposited extracellular
matrix. Using this approach, cell sheets can be directly transplanted to host
tissues without the use of scaffolding or carrier materials, or used to create in
vitro tissue constructs via the layering of individual cell sheets. In addition
to simple transplantation, cell sheet engineered constructs have also been
applied for alternative therapies such as endoscopic transplantation,
combinatorial tissue reconstruction, and polysurgery to overcome limitations of
regenerative therapies and cell delivery using conventional approaches.
Optimal parameters for the treatment of leg veins using Nd:YAG lasers at 1064 nm. Bäumler W, Ulrich H, Hartl A, Landthaler M, Shafirstein G. Br J Dermatol. 2006 Aug;155(2):364-71.
BACKGROUND: The treatment of large vessels such as leg veins is successfully
performed in clinical practice using pulsed Nd:YAG lasers. However, it is still
unclear how laser parameters such as wavelength, fluence and pulse duration
influence vessel destruction in leg veins. OBJECTIVES: To elucidate the governing
parameters in selective photothermolysis of large vessels. METHODS: A recently
developed mathematical model for photothermolysis has been adapted for the
treatment of leg veins. The model was used to analyse the effectiveness of the
selective photothermolysis process in laser treatment of leg veins by Nd:YAG at
1064 nm. The efficiency of laser-induced vessel heating was defined as a ratio
between the absorbed and delivered energy. RESULTS: The efficiency improved with
increasing vessel diameter, in agreement with clinical findings in various
studies. The pulse duration made a minor contribution for laser fluences of
100-400 J cm(-2), whereas the efficiency was better for a small spot. The use of
moderate fluences of 100-200 J cm(-2) reduced excess dermis heating and pain.
CONCLUSIONS: We provide reference parameters for optimal treatment of leg veins
using Nd:YAG lasers at 1064 nm. Our model predicts a maximal efficiency of a
range of fluences (100-200 J cm(-2)) and pulse durations (10-100 ms).
Developing optofluidic technology through the fusion of microfluidics and optics. Psaltis D, Quake SR, Yang C. Nature. 2006 Jul 27;442(7101):381-6.
We describe devices in which optics and fluidics are used synergistically to
synthesize novel functionalities. Fluidic replacement or modification leads to
reconfigurable optical systems, whereas the implementation of optics through the
microfluidic toolkit gives highly compact and integrated devices. We categorize
optofluidics according to three broad categories of interactions: fluid-solid
interfaces, purely fluidic interfaces and colloidal suspensions. We describe
examples of optofluidic devices in each category.
Laser therapy for solar lentigines: review of the literature and case report. Bukvić Mokos Z, Lipozencić J, Pasić A, Fattorini I. Acta Dermatovenerol Croat. 2006;14(2):81-5.
Solar lentigines are benign, brownish lesions that occur on light exposed skin
surfaces from age 30 onwards, as a sign of photoaging. As they are of cosmetic
importance to many patients, different therapeutic modalities have been tried to
remove these unwanted spots. The recent development of short-pulsed,
pigment-specific lasers has enabled physicians to selectively destroy the pigment
within the solar lentigo lesions with significant clinical improvement, low risk
of adverse effects, and high patient acceptance. Therefore this therapeutic
option is superior to traditional treatment modalities and represents the
treatment of choice in the management of solar lentigines. A case is reported of
the successful use of Q-switched ruby laser in the treatment of solar lentigo on
[PresbyLASIK: treatment approaches with the excimer laser] [Article in German] Becker KA, Jaksche A, Holz FG. Ophthalmologe. 2006 Aug;103(8):667-72.
Presbyopia represents the most common refractive error. There is currently no
surgical treatment for presbyopia, which is effective, reliable, and safe.Excimer
laser surgery has become a routine procedure for the correction of myopia,
hyperopia, and astigmatism for years. Various treatment strategies for presbyopia
have been brought forward using the excimer lasers. Besides monovision, creation
of a multifocal cornea represents an attractive option. This procedure is also
called “PresbyLASIK.” Different ablation profiles to form a multifocal cornea are
reviewed here and first clinical results are summarized.”PresbyLASIK” is a new,
interesting treatment strategy, with a huge potential for the future. At the
present it should be used in controlled studies only because of some unsolved
Current developments using emerging transdermal technologies in physical enhancement methods. Nanda A, Nanda S, Ghilzai NM. Curr Drug Deliv. 2006 Jul;3(3):233-42.
Transdermal drug delivery using patches offers many advantages, but is limited
primarily by the stratum corneum barrier. Amongst the various methods to overcome
this barrier, physical methods are gaining in popularity and commercial devices
development. Macroflux, MTS and Silex are based on microporation, involving use
of microneedles that pierce thereby bypassing the stratum corneum. Intraject ,
Powderject and Helios are based on needleless jet injectors wherein very fine,
solid particulate drug, is fired directly into the skin, using high-pressure gas.
Med- Tats incorporate use of modified drug-containing tattoos, which bind to the
skin, wherein the drug is absorbed. CHADD is based on use of heat, which
increases skin – permeation of drugs. High-power, pulsed lasers transmit positive
mechanical forces to the skin and create intercellular channels into the skin
transiently. Sonophoresis involves use of ultrasound, which transiently disrupts
the stratum corneum barrier. This technique offers a non-invasive transdermal
extraction of interstitial fluids of sampling body fluids. Modified Liposomes
include Ethosomes (containing alcohol) and Transferosomes (containing
surfactants), which have enhanced skin permeability. Pulsed magnetic fields may
create transient pores in cell membranes, including skin, resulting in increased
permeation. Iontophoresis is based on application of electric potential for
enhancing the movement of substances to and from the body. Dupel, Ionzyme,
Liposite, ETrans, Phoresor and Drionic are based on iontophoresis. GlucoWatch
offers non-invasive blood glucose monitoring, based on reverse iontophoresis.
This review outlines recent commercial developments in physical transdermal drug
delivery technology and the specific devices and applications being targeted by
the pharmaceutical industry.
Indications and limitations of Er:YAG laser applications in dentistry. Bader C, Krejci I. Am J Dent. 2006 Jun;19(3):178-86.
PURPOSE: To describe the development, indications, and limitations of Er:YAG
lasers in the dental field. METHODS: A review based on the literature search in
PubMed and completed by other documents was performed. RESULTS: Based on the
synthesis of the reviewed literature different topics concerning the Er:YAG
effects and applications in dentistry are discussed and recommendations for the
use of this type of laser are given.
[Laser capture microdissection and its application in andrology] [Article in Chinese] Wang M, Xu C. Zhonghua Nan Ke Xue. 2006 Jun;12(6):545-7.
Laser capture microdissection (LCM) is a novel technique developed in the recent
years. Under direct microscopic visualization, LCM permits rapid one-step
procurement of the selected pure target cell subgroup, even a single cell from a
section of the complex, heterogeneous tissue. This technique has rapidly been
introduced in the researches for the cellular and molecular mechanisms of
diseases. It helps improve diagnosis, therapy and prognosis. This article reviews
the progress in the application of LCM in andrology.
[Laser nanosurgery in cell biology] [Article in French] Colombelli J, Pepperkok R, Stelzer EH, Reynaud EG. Med Sci (Paris). 2006 Jun-Jul;22(6-7):651-8.
Since their first use in the early 60′s, pulsed lasers have become increasingly
popular for their ability to ablate biological tissue. Short laser pulses allow
high precision surgery for biological and medical applications with minimal
invasiveness. Performing highly targeted manipulation and ablation allows
experiments impossible so far in development biology, cellular biology or even
assisted reproductive technologies and laser surgery has been increasingly used
over the last five years to answer key questions in Biology. Recently, picosecond
UV and femtosecond IR laser pulses have been used to cleave microtubules and to
severe actin stress fibers in vivo with a spatial precision in the submicrometer
range to study their dynamics without affecting cell viability. We review recent
findings on the underlying principles of pulsed laser nanosurgery mechanisms
showing how the use of ultra short laser pulses increases precision and
non-invasiveness of laser surgery. We show how the understanding of the surgical
process allows one to distinguish between single cell ablation in living
organisms or intracellular nanosurgery in living cells and we review recent
applications to the study of forces and the quantification of cytoskeleton
Biologically active molecules with a “light switch”. Mayer G, Heckel A. Angew Chem Int Ed Engl. 2006 Jul 24;45(30):4900-21.
Biologically active compounds which are light-responsive offer experimental
possibilities which are otherwise very difficult to achieve. Since light can be
manipulated very precisely, for example, with lasers and microscopes rapid jumps
in concentration of the active form of molecules are possible with exact control
of the area, time, and dosage. The development of such strategies started in the
1970s. This review summarizes new developments of the last five years and deals
with “small molecules”, proteins, and nucleic acids which can either be
irreversibly activated with light (these compounds are referred to as “caged
compounds”) or reversibly switched between an active and an inactive state.
Manual versus laser micro-dissection in molecular biology. Hernández S, Lloreta J. Ultrastruct Pathol. 2006 May-Jun;30(3):221-8.
Molecular studies on whole samples of fresh or frozen tissue do not take into
account the heterogeneity of these tissues. In addition to normal cells,
precursor lesions and different progression stages may be mixed within a given
sample. Usually, the dominant cell population will determine the results and may
sometimes mask biologically relevant abnormalities. To obtain more specific
information and knowledge on changes within different cell compartments, many
techniques have been developed that combine morphological observation and
selection with different strategies for specific cell dissection. In this review,
the most important micro-dissection methods are put into perspective, and some
requirements and limitations are discussed with regard to sample fixation,
staining, dissection and molecular analysis.
The use of lasers for decorative tattoo removal. Mariwalla K, Dover JS. Skin Therapy Lett. 2006 Jun;11(5):8-11.
As the incidence of tattoo placement continues to increase, so does the demand
for tattoo removal, with more than 10 million people in the US alone with a
tattoo. Used in an appropriate clinical setting, Q-switched lasers provide
relatively efficacious clearance of decorative tattoo pigment with minimal
side-effects. We present our clinical experience along with literature findings
on decorative tattoo removal and the important issues practitioners should
consider in the management of tattoos.
External bleaching therapy with activation by heat, light or laser–a systematic review. Buchalla W, Attin T. Dent Mater. 2007 May;23(5):586-96. Epub 2006 Jul 3.
OBJECTIVE: External bleaching procedures utilizing highly concentrated 30-35%
hydrogen peroxide solutions or hydrogen peroxide releasing agents can be used for
tooth whitening. To enhance or accelerate the whitening process, heat-activation
of the bleaching agent by light, heat or laser is described in the literature.
The aim of the present review article was to summarize and discuss the available
information concerning the efficacy, effects and side effects of activated
bleaching procedures. SOURCES: Information from all original scientific full
papers or reviews listed in PubMed or ISI Web of Science (search term: (bleaching
OR brightening OR whitening OR colour) AND (light OR laser OR heat OR
activation)) were included in the review. DATA: Existing literature reveals that
activation of bleaching agents by heat, light or laser may have an adverse effect
on pulpal tissue due to an increase of intra-pulpal temperature exceeding the
critical value of 5.5 degrees C. Available studies do not allow for a final
judgment whether tooth whitening can either be increased or accelerated by
additional activation. CONCLUSION: Therefore, application of activated bleaching
procedures should be critically assessed considering the physical, physiological
and patho-physiological implications.
Screening oocytes by polar body biopsy. Dawson A, Griesinger G, Diedrich K. Reprod Biomed Online. 2006 Jul;13(1):104-9.
Preimplantation genetic aneuploidy screening performed by polar body biopsy has
become a frequently used method, especially as in several countries only
preconceptional genetic diagnosis is allowed. To penetrate the zona pellucida,
mechanical, chemical and laser-assisted techniques have been introduced. In this
paper, the advantages, disadvantages, efficacy and safety of these techniques are
A review of the adverse effects of laser hair removal. Lim SP, Lanigan SW. Lasers Med Sci. 2006 Sep;21(3):121-5. Epub 2006 Jul 1.
Laser hair removal is ever increasing in popularity. Technology is fast
advancing, and there are increasingly excessive commercial claims that laser hair
removal in all skin types is free of side effects. The aim of this study is to
review the evidence from published literature regarding the incidence of adverse
effects after laser and light systems for hair removal. A review of the current
published literature on the ill effects reported after laser/light-assisted
depilation was conducted. Overall incidence of adverse effects after laser/light
hair removal appears to be low, with very uncommon permanent sequelae. The two
largest studies to date have shown that acute and transient side effects do
occur. Higher incidence of pigmentary alterations is associated with the shorter
wavelength lasers (up to 19%), particularly with darker skin types, compared with
lower incidence using the neodymium-yttrium-aluminium-garnet laser (2-3%). Both
studies did not show any long-term side effects or scarring. Laser/light hair
removal, carried out by trained professionals, is a safe procedure with a very
low incidence of permanent sequelae. The majority of adverse effects are
transient and minor. They are more common in darker skin. Longer wavelength
devices reduce the risk in darker skin.
Recent advances in laser synthesis of single-walled carbon nanotubes. Kingston CT, Simard B. J Nanosci Nanotechnol. 2006 May;6(5):1225-32.
Very shortly following the discovery of single-walled carbon nanotubes
laser-based methods emerged as reliable ways to produce moderate quantities with
very consistent composition and properties. They have also proven to be good
platforms for the systematic investigation of various synthesis parameters in the
hope of better understanding the growth process. Several variations exist with
differences such as laser wavelength, number of lasers, background temperature,
and target composition. A number of common elements have emerged for the
production of both high quality and high yields of SWNT, such as the
effectiveness of bimetal catalysts like CoNi and NiY, and the need for high
process temperatures and controlling the rate of cooling. Combined with the
growing amount of in situ diagnostic and computational modelling data we are
slowly making progress towards understanding the growth process. This article
will present an overview of recent advancements in laser-based synthesis methods
and what information can be extracted about the growth process.
Proteomics and laser microdissection. McGregor E, De Souza A. Methods Mol Biol. 2006;333:291-304.
Two-dimensional gel electrophoresis (2-DE) combined with protein identification
by mass spectrometry (MS) is currently the method of choice in the majority of
proteomic projects. Novel gel-free technologies have been developed but 2-DE
remains the technique of choice for quantitative expression profiling of large
sets of complex protein mixtures such as whole cell/tissue lysates. Solubilized
proteins are separated in the first dimension according to their charge
properties (isoelectric point, pI) by isoelectric focusing (IEF) under denaturing
conditions, followed by their separation in the second dimension by sodium
dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), according to their
relative molecular mass (Mr). 2-DE can resolve more than 5000 proteins
simultaneously (approximately 2000 proteins routinely) and can detect less than 1
ng of protein per spot. Furthermore, it delivers a map of intact proteins, which
reflects changes in protein expression level, isoforms or posttranslational
modifications. In this chapter we describe the various steps in the 2-DE
proteomics workflow, namely sample preparation, solubilization, 2-D gel
electrophoresis, protein detection and visualization, and protein identification
by mass spectrometry. The use of 2-DE in conjunction with laser microdissection
microscopy is presented and discussed.
Age-related macular degeneration. Arden GB. J Br Menopause Soc. 2006 Jun;12(2):64-70.
Age-related macular degeneration is a common cause of blindness. Its incidence is
increasing, partly due to the advancing age of the population in North America
and Europe, but there is no doubt that the age-adjusted rates are also
increasing, which points to some environmental influence. The condition is
characterized by the appearance of retinal deposits called drusen. These and
other changes form a barrier between the retinal pigment epithelium and the
choroidal circulation. As a result, new vessels may grow from the choroid and
penetrate the retina. These new vessels are delicate and can leak or bleed. Such
episodes occur in the “wet” form of age-related macular degeneration and cause
the well known disciform degeneration, which in turn leads to distortion of the
image and rapid loss of vision. Even when this does not happen, areas of retina
may atrophy, probably due to anoxia: this is the “dry” form of the disease, also
called geographic atrophy. In trials, scattered laser burns have been applied to
the retina but the long-term benefits of this are as yet uncertain. New
micro-pulse lasers are coming into use which may be more effective. Surgical
treatments include translocation of the retina and photodynamic therapy. Medical
therapies attracting attention are intraocular injections of anti-angiogenic
drugs, such as ranibizumab. These need further evaluation, as does the role of
diet. Within a few years blindness due to age-related macular degeneration may be
reduced by combining dietary control, screening for visual loss, and medical and
surgical methods of treatment.
[Refractive surgery--possibilities to maximize postoperative visual acuity] [Article in Romanian] Tudor C, Hubert C. Oftalmologia. 2006;50(1):5-9.
Laser refractive surgery has an ascendant evolution on the context of the
progress in the medical field. The functional result can be negatively influenced
by residual errors, irregular astigmatism or anisometropia, situations in which
rigid gas permeable (RGP) contact lenses are a successful alternative in
optimizing visual acuity. The paper presents the particularities and the protocol
of RGP fitting, outlining the contribution of the corneal topography in the
ocular pre and post-operative evaluation.
Laser processing for bio-microfluidics applications (part I). Khan Malek CG. Anal Bioanal Chem. 2006 Aug;385(8):1351-61. Epub 2006 Jun 14.
This paper reviews applications of laser-based techniques to the fabrication of
microfluidic devices for biochips and addresses some of the challenges associated
with the manufacture of these devices. Special emphasis is placed on the use of
lasers for the rapid prototyping and production of biochips in particular for
applications in which silicon is not the preferred material base. Part I of this
review addresses applications and devices using UV lasers for laser ablation and
surface treatment of microchannels, in particular in polymers.
Laser processing for bio-microfluidics applications (part II). Khan Malek CG. Anal Bioanal Chem. 2006 Aug;385(8):1362-9. Epub 2006 Jun 14.
This paper reviews applications of laser-based techniques to the fabrication of
microfluidic devices for biochips and addresses some of the challenges associated
with the manufacture of these devices. Special emphasis is placed on the use of
lasers for the rapid prototyping and production of biochips, in particular for
applications in which silicon is not the preferred material base. This review
addresses applications and devices based on ablation using femtosecond lasers,
infrared lasers as well as laser-induced micro-joining, and the laser-assisted
generation of micro-replication tools, for subsequent replication of polymeric
chips with a technique like laser LIGA.
Antiaging therapies. Vedamurthy M. Indian J Dermatol Venereol Leprol. 2006 May-Jun;72(3):183-6.
[Phototherapeutic keratectomy. Basic principles, techniques and indications] [Article in German] Sekundo W, Geerling G. Ophthalmologe. 2006 Jul;103(7):563-9.
Phototherapeutic keratectomy (PTK) involves the removal of corneal tissue with an
excimer laser for therapeutic and/or functional purposes. In contrast to
photorefractive keratectomy, a change in manifest refraction is not the primary
goal of the treatment. The main indications are poor epithelial adherence,
corneal opacities or an irregular corneal surface, as well as combinations of
these. We describe the basic techniques, such as large area and focal PTK and
provide recommendations on use of different masking agents. Numerous well
established and rare clinical examples are described in terms of achievable PTK
Endonasal laser surgery: an update. Levine HL. Otolaryngol Clin North Am. 2006 Jun;39(3):493-501, viii.
Although surgical lasers were introduced more than 30 years ago,their use and
popularity in nasal and sinus disease have been limited. Even so, there are many
practitioners who find the laser a valuable surgical tool for nasal and sinus
disease, either alone or in combination with other treatment modalities. Those
who do not use lasers probably do not because of a lack of skill, knowledge,or
understanding of the role and availability of the technology. This article
reviews the history and current role of lasers in nasal and sinus surgery.
Coherent anti-stokes Raman scattering microscopy: a biological review. Rodriguez LG, Lockett SJ, Holtom GR. Cytometry A. 2006 Aug 1;69(8):779-91.
Microscopic imaging of cells and tissues are generated by the interaction of
light with either the sample itself or contrast agents that label the sample.
Most contrast agents, however, alter the cell in order to introduce molecular
labels, complicating live cell imaging. The interaction of light from multiple
laser sources has given rise to microscopy, based on Raman scattering or
vibrational resonance, which demonstrates selectivity to specific chemical bonds
while imaging unmodified live cells. Here, we discuss the nonlinear optical
technique of coherent anti-Stokes Raman scattering (CARS) microscopy, its
instrumentation, and its status in live cell imaging. (c) 2006 International
Society for Analytical Cytology.
Making sense of lanthanide luminescence. Werts MH. Sci Prog. 2005;88(Pt 2):101-31.
The luminescence of trivalent lanthanide ions has found applications in lighting,
lasers, optical telecommunications, medical diagnostics, and various other
fields. This introductory review presents the basics of organic and inorganic
luminescent materials containing lanthanide ions, their applications, and some
recent developments. After a brief history of the discovery, purification and
early spectroscopic studies of the lanthanides, the radiative and nonradiative
transitions of the 4f electrons in lanthanide ions are discussed.
Lanthanide-doped phosphors, glasses and crystals as well as luminescent
lanthanide complexes with organic ligands receive attention with respect to their
preparation and their applications. Finally, two recent developments in the field
of luminescent materials are addressed: near-infrared luminescent lanthanide
complexes and lanthanide-doped nano-particles.
Multiphoton laser scanning microscopy as a tool for Xenopus oocyte research. Prouty AM, Wu J, Lin DT, Camacho P, Lechleiter JD. Methods Mol Biol. 2006;322:87-101.
Multiphoton laser scanning microscopy (MPLSM) has become an increasingly
invaluable tool in fluorescent optical imaging. There are several distinct
advantages to implementing MPLSM as a Xenopus oocyte research tool. MPLSM
increases signal-to-noise ratio and therefore increases image quality because
there is no out-of-focus fluorescence as would be created in conventional or
confocal microscopy. All the light that is generated can be collected and used to
generate an image because point detection of descanned fluorescence is not
required. This is particularly useful when imaging deep into tissue sections, as
is necessary for Xenopus oocytes, which are notoriously large (approximately 1-mm
diameter). Because multiphoton lasers use pulsed energy in the infrared
wavelengths, the energy can also travel further into tissues with much less light
scattering. Because there is no out-of-focus excitation, phototoxicity,
photodamage, and photobleaching are significantly reduced, which is particularly
important for long-term experiments that require the same region to be scanned
repeatedly. Finally, multiple fluorophores can be simultaneously excited because
of the broader absorption spectra of multiphoton dyes. In this chapter, we
describe the advantages and disadvantages of using MPLSM to image Xenopus oocytes
as compared to conventional and confocal microscopy. The practical application of
imaging oocytes is demonstrated with specific examples.
[Phototherapeutic keratectomy. Undesirable effects, complications, and preventive strategies] [Article in German] Geerling G, Sekundo W. Ophthalmologe. 2006 Jul;103(7):576-82.
The conceptual advantage of phototherapeutic keratectomy (PTK) include the option
to remove diseased tissue on a micrometer scale. Although less invasive than
other forms of corneal surgery, it remains a surgical procedure which carries
inherent risks. In phototherapeutic indications this risk is higher than in
otherwise healthy eyes undergoing photorefractive surgery. Potential general
complications include wound-healing problems, infection, inflammation, or a
recurrence of the underlying disease. More specifically, PTK is associated with
unwanted refractive changes, such as a hyperopic shift or an irregular
astigmatism. In this review, we discuss these problems along with prevention and
treatment strategies in detail.
Towards a more specific therapy: targeting nonmelanoma skin cancer cells. Szeimies RM, Karrer S. Br J Dermatol. 2006 May;154 Suppl 1:16-21.
Epithelial cancers of the skin, e.g. basal cell carcinoma and squamous cell
carcinoma, are the most common tumours in humans with increasing incidence. Hence
the development of new therapeutic strategies is of utmost interest. For many
years the most often used conventional therapies for these diseases were surgical
procedures such as curettage and electrodesiccation, excision or, with so far the
best outcome in terms of remission rates, micrographic surgery. Other ablative
treatment modalities are cryotherapy, radiation therapy or the use of lasers
(Er:YAG, CO(2)). All those above-mentioned treatments have in common that they
are quite unspecific and do not target the tumour itself or its environment, thus
leading to unwanted effects in the surrounding tissue such as scar formation or
other cosmetically disfiguring events. Therefore, the development of novel, more
pathogenesis-based therapies such as the use of retinoids, cyclooxygenase
inhibitors, topical immunomodulators, inhibitors of the sonic-hedgehog signalling
pathway or photodynamic therapy are challenging new approaches.
Two-photon singlet oxygen microscopy: the challenges of working with single cells. Skovsen E, Snyder JW, Ogilby PR. Photochem Photobiol. 2006 Sep-Oct;82(5):1187-97.
A microscope is described in which singlet molecular oxygen, O2(a1deltag), is
produced in a femtoliter focal volume via a nonlinear two-photon photosensitized
process, and the 1270 nm phosphorescence from this population of O2(a1deltag) is
detected in a photon counting experiment. Although two-photon excitation of a
sensitizer is less efficient than excitation by a one-photon process, nonlinear
excitation has several distinct advantages with respect to the spatial resolution
accessible. Pertinent aspects of this two-photon O2(a1deltag) microscope were
characterized using bulk solutions of photosensitizers. These data were compared
to those obtained from a single biological cell upon linear one-photon excitation
of a sensitizer incorporated in the cell. On the basis of the results obtained,
we outline the challenges of using nonlinear optical techniques to create
O2(aldeltag) at the single cell level and to then optically detect the
O2(aldeltag) thus produced in a time-resolved experiment.
Refractive issues in pregnancy. Sharma S, Rekha W, Sharma T, Downey G. Aust N Z J Obstet Gynaecol. 2006 Jun;46(3):186-8.
Pregnancy is known to cause refractive changes as a result of various hormonal
changes occurring during pregnancy. These changes may persist for a few weeks
post-partum and during lactation. In this article we discuss various refractive
issues in pregnancy that have an effect on contact lens use, myopia and the
outcome of refractive surgery.
Art and science of photodynamic therapy. Pervaiz S, Olivo M. Clin Exp Pharmacol Physiol. 2006 May-Jun;33(5-6):551-6.
1. Photodynamic therapy is an established modality for the treatment of solid
tumours and other accessible lesions. Although the concept and practice of
combining light with a photosensitizing agent for the treatment of disease states
has been around for almost a century, the understanding of the art and science
therein has been tremendously enhanced over the past few years. 2.
Photosensitized reactions are dependent on the generation of reactive oxygen
species, in particular singlet oxygen, which accounts for the damaging effects on
biological macromolecules, such as membrane lipids and proteins. Therefore,
compounds that give a good yield of (1)O(2) are used as photosensitizers. 3. The
main photosensitizers used in the clinical setting belong to the photofrin
family; however, newer and more effective sensitizers are being evaluated for
their potential clinical effectiveness. 4. Light sources have moved from the use
of white light with specific filters in the old days to the more recent use of
monochromatic light sources, such as lasers, to more sophisticated light-emitting
diodes. However, dosimetry remains a big issue mainly because of difficulties in
establishing the optimum treatment conditions for an approach that requires the
fine-tuning of several variables, such as sensitizer and light doses and
drug-to-light interval, as well as the issues of skin photosensitivity and low
selectivity. A newer development to circumvent these and provide a broader
application for this concept has been the phenomenon of photo-activation, whereby
photo-exposure of chromophores to generate novel, small biologically active
compounds has been demonstrated successfully. 5. The aim of the present review
was to provide a general overview of the art and science of photodynamic therapy
and to highlight some of the issues and recent developments in further advancing
this modality of treatment.
Lentigo maligna/lentigo maligna melanoma: current state of diagnosis and treatment. McKenna JK, Florell SR, Goldman GD, Bowen GM. Dermatol Surg. 2006 Apr;32(4):493-504.
BACKGROUND: Lentigo maligna (LM) is a subtype of melanoma in situ that typically
develops on sun-damaged skin. Presentation may be quite subtle and delayed
diagnosis is common. Clinical margins are often ill defined. Histologic
evaluation can be difficult due to the widespread atypical melanocytes that are
present in the background of long-standing sun damage. Recurrence following
standard therapies is common. OBJECTIVE: To review the clinical features,
histopathology, and treatment options for LM. Emphasis is placed on recent
advances in the treatment of LM. METHODS AND MATERIALS: Literature review.
RESULTS: The estimated lifetime risk of LM progressing to LM melanoma is 5%.
Standard excision of LM with 5 mm margins is insufficient in 50% of cases. The
recurrence rate with standard excision ranges from 8 to 20%. Mohs surgery and
staged excision may offer better margin control and lower recurrence rates
(4-5%). Estimates of recurrence rates following nonsurgical therapies such as
cryosurgery, radiotherapy, electrodessication and curettage, laser surgery, and
topical medications range from 20 to 100% at 5 years. CONCLUSIONS: Adequate
treatment of LM requires a comprehensive knowledge of the diagnostic features,
histopathology, and treatment options. Surgical modalities with meticulous
evaluation of tissue margins appears to offer the lowest rates of disease
Laser microdissection of plant tissue: what you see is what you get. Nelson T, Tausta SL, Gandotra N, Liu T. Annu Rev Plant Biol. 2006;57:181-201.
Laser microdissection (LM) utilizes a cutting or harvesting laser to isolate
specific cells from histological sections; the process is guided by microscopy.
This provides a means of removing selected cells from complex tissues, based only
on their identification by microscopic appearance, location, or staining
properties (e.g., immunohistochemistry, reporter gene expression, etc.). Cells
isolated by LM can be a source of cell-specific DNA, RNA, protein or metabolites
for subsequent evaluation of DNA modifications, transcript/protein/metabolite
profiling, or other cell-specific properties that would be averaged with those of
neighboring cell types during analysis of undissected complex tissues. Plants are
particularly amenable to the application of LM; the highly regular tissue
organization and stable cell walls of plants facilitate the visual identification
of most cell types even in unstained tissue sections. Plant cells isolated by LM
have been the starting point for a variety of genomic and metabolite studies of
specific cell types.
Laser eye surgery for refractive errors. Sakimoto T, Rosenblatt MI, Azar DT. Lancet. 2006 Apr 29;367(9520):1432-47.
Several laser and non-laser refractive surgical procedures have been used to
modify the shape of the cornea and correct myopia, hyperopia, astigmatism, and
presbyopia. Introduction of the excimer laser to reshape the cornea has resulted
in remarkable developments in the correction of these refractive errors. Combined
with other advanced ophthalmological instruments, laser refractive eye surgery
has resulted in a substantial rise in the safety, efficacy, and predictability of
surgical outcomes. Despite these advances, certain limitations and complications
persist. In this review, we describe the history, preoperative assessment,
surgical techniques, outcomes, and complications of laser refractive surgery.
Current role of lasers in the treatment of benign prostatic hyperplasia (BPH). Kuntz RM. Eur Urol. 2006 Jun;49(6):961-9. Epub 2006 Mar 31.
OBJECTIVE: Evaluate the current role of lasers in the treatment of benign
prostatic hyperplasia (BPH). METHODS: The results of a MEDLINE search for
randomised trials and case series of the last 5 yr and published review articles
were analysed for the safety and efficacy of neodymium:yttrium aluminum garnet
(Nd:YAG), potassium-titanyl-phosphate (KTP), and holmium (Ho):YAG laser
prostatectomy. The analysis includes 12 reports on randomised clinical trials, 2
comparative studies, 10 review articles, and a total of >5000 patients. RESULTS:
Laser treatment of BPH has evolved from coagulation to enucleation. Blood loss is
significantly reduced compared with transurethral resection and open
prostatectomy. Visual laser ablation of the prostate and interstitial laser
coagulation cause coagulative necrosis with secondary ablation. Long
postoperative catheterisation, unpredictable outcomes, and high reoperation rates
have restricted the use of these techniques. Ablative/vaporising techniques have
become popular again with the marketing of new high-powered 80-W KTP and 100-W Ho
lasers. Vaporisation immediately removes obstructing tissue. Short-term results
are promising, but large series, long-term results, and randomised trials are
lacking. Holmium laser enucleation (HoLEP) allows whole lobes of the prostate to
be removed, mimicking the action of the index finger in open prostatectomy.
Prostates of all sizes can be operated on. It is at least as safe and effective
as transurethral resection of the prostate and open prostatectomy, with
significantly lower morbidity. It is the only laser procedure that provides a
specimen for histologic evaluation. CONCLUSIONS: HoLEP appears to be a
size-independent new “gold standard” in the surgical treatment of BPH.
Treatment of melasma. Rendon M, Berneburg M, Arellano I, Picardo M. J Am Acad Dermatol. 2006 May;54(5 Suppl 2):S272-81.
Treatment of melasma involves the use of a range of topical depigmenting agents
and physical therapies. Varying degrees of success have been achieved with these
therapies. The Pigmentary Disorders Academy (PDA) undertook to evaluate the
clinical efficacy of the different treatments of melasma in order to generate a
consensus statement on its management. Clinical papers published during the past
20 years were identified through MEDLINE searches and methodology and outcome
assessed according to guidelines adapted from the US Preventive Services Task
Force (USPSTF). The consensus of the group was that first-line therapy for
melasma should consist of effective topical therapies, mainly fixed triple
combinations. Where patients have either sensitivity to the ingredients or a
triple combination therapy is unavailable, other compounds with dual ingredients
(hydroquinone plus glycolic acid) or single agents (4% hydroquinone, 0.1%
retinoic acid, or 20% azelaic acid) may be considered as an alternative. In
patients who failed to respond to therapy, options for second-line therapy
include peels either alone or in combination with topical therapy. Some patients
will require therapy to maintain remission status and a combination of topical
therapies should be considered. Lasers should rarely be used in the treatment of
melasma and, if applied, skin type should be taken into account.
Treatment of solar lentigines. Ortonne JP, Pandya AG, Lui H, Hexsel D. J Am Acad Dermatol. 2006 May;54(5 Suppl 2):S262-71.
Therapy for solar lentigines is diverse but can be divided into two broad
categories: physical therapy and topical therapy. Physical therapies are
frequently used with excellent clinical success rates, but this has to be
balanced against associated side effects and recurrence rates with certain
therapies. A range of topical therapies have been used and, more recently, fixed
combinations of topical agents have been investigated. The Pigmentary Disorders
Academy undertook to evaluate the clinical efficacy of the different treatments
of solar lentigines in order to generate a consensus statement on their
management. Clinical papers published during the past 20 years were identified
through MEDLINE searches and methodology and outcome were assessed according to
guidelines adapted from the US Preventive Services Task Force (USPSTF) on health
care. The consensus of the group was that first-line therapy for solar lentigines
was ablative therapy with cryotherapy. Although no large-scale studies have been
completed, there is also good evidence to suggest that lasers are an effective
treatment. An alternative to ablative therapy is topical therapy and there is
good evidence to support the use of a fixed double combination, as well as
retinoids, such as adapalene and tretinoin. Topical therapy can also be
considered as maintenance therapy after the primary therapy has been applied.
Because of the diversity of scoring systems used in the assessment of treatment
outcome, the group recommends the development of treatment guidelines.
Fifteen years ago laser was supposed to open arteries, now it is supposed to close veins: what is the reality behind the tool? Kalra M, Gloviczki P. Perspect Vasc Surg Endovasc Ther. 2006 Mar;18(1):3-8.
Laser first emerged as a technology for use in the vascular arena nearly 20 years
ago. The ability of laser to evaporate atherosclerotic plaque was extensively
studied; however, the goal of creation of an adequate channel without arterial
wall perforation proved to be elusive, and the technique fell into disfavor. More
than a decade later, interest in lasers was sparked again with its application to
endovenous thermal ablation of axial superficial venous reflux. The mechanism of
action of endovenous laser therapy involves thermal damage of the vein wall,
resulting in destruction of the intima and collagen denaturation of the media
with eventual fibrotic occlusion of the vein. Apart from the obvious attraction
of a minimally invasive procedure to ablate superficial venous reflux with its
attendant benefits, another advantage of laser ablation includes a potentially
decreased incidence of neovascularization in the groin secondary to preservation
of superficial venous drainage of the abdominal wall. Early success in terms of
ablation of the refluxing saphenous vein has been reported as 90% to 95%. Minor
complications are reported in 3% to 10% of patients and include bruising around
the puncture site, transient paresthesias, superficial phlebitis, and skin burns
or pigmentation. The more serious complications of deep venous thrombosis or
extension of thrombus into the femoral vein have been variously reported in 0% to
2.3% of limbs treated. Pulmonary embolism is extremely rare. There is a learning
curve, with a decrease in the incidence of all complications with experience. The
importance of detailed preoperative and intraoperative duplex ultrasound
examination cannot be overemphasized. The identification of all refluxing venous
segments and their ablation is the key to optimizing the rate of successful
ablation to 97% at 1 year and minimizing recurrence of varicose veins. With
encouraging early and mid-term results with endovenous laser therapy, future
developments in this field must mandate standardization of technical aspects,
follow-up imaging, and reporting.
Photorefractive keratectomy (PRK) versus laser-assisted in-situ keratomileusis (LASIK) for myopia. Shortt AJ, Allan BD. Cochrane Database Syst Rev. 2006 Apr 19;(2):CD005135.
BACKGROUND: Myopia (also known as short-sightedness or near-sightedness) is an
ocular condition in which the refractive power of the eye is greater than is
required, resulting in light from distant objects being focused in front of the
retina instead of directly on it. The two most commonly used surgical techniques
to permanently correct myopia are photorefractive keratectomy (PRK) and
laser-assisted in-situ keratomileusis (LASIK). OBJECTIVES: The aim of this review
was to compare the effectiveness and safety of PRK and LASIK for correction of
myopia. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled
Trials (CENTRAL) in The Cochrane Library (2005, Issue 3), MEDLINE (1966 to
September 2005), EMBASE (1980 to September 2005) and LILACs (1982 to 3 November
2005). We also searched the reference lists of the studies and the Science
Citation Index. SELECTION CRITERIA: We included randomised controlled trials
comparing PRK and LASIK for correction of any degree of myopia. We also included
data on adverse events from prospective multicentre consecutive case series in
the Food and Drugs Administration (FDA) trials database
(http//www.fda.gov/cdrh/LASIK/lasers.htm). DATA COLLECTION AND ANALYSIS: Two
authors independently assessed trial quality and extracted data. Data were
summarised using odds ratio and mean difference. Odds ratios were combined using
a random-effects model after testing for heterogeneity. MAIN RESULTS: This review
included six randomised controlled trials involving a total of 417 eyes, of which
201 were treated with PRK and 216 with LASIK. We found that although LASIK gives
a faster visual recovery than PRK, the effectiveness of these two procedures is
comparable. We found some evidence that LASIK may be less likely than PRK to
result in loss of best spectacle-corrected visual acuity. AUTHORS’ CONCLUSIONS:
LASIK gives a faster visual recovery than PRK but the effectiveness of these two
procedures is comparable. Further trials using contemporary techniques are
required to determine whether LASIK and PRK are equally safe.
Low level laser therapy for treating tuberculosis. Vlassov VV, MacLehose HG. Cochrane Database Syst Rev. 2006 Apr 19;(2):CD003490.
BACKGROUND: The main treatment for tuberculosis is antituberculous drugs. Low
level laser therapy is used as an adjunct to antituberculous drugs, predominantly
in the former Soviet Union and India. OBJECTIVES: To compare low level laser
therapy plus antituberculous drugs with antituberculous drugs alone for treating
tuberculosis. SEARCH STRATEGY: We searched the Cochrane Infectious Diseases Group
Specialized Register (December 2005), CENTRAL (The Cochrane Library 2005, Issue
4), MEDLINE (1966 to December 2005), EMBASE (1974 to December 2005), CINAHL (1982
to December 2005), Science Citation Index (1945 to December 2005), PEDro (1929 to
December 2005), the Central Medical Library of Moscow catalogue (1988 to June
2005), the internet, and reference lists of articles. We contacted relevant
organizations and researchers for the original version. SELECTION CRITERIA:
Randomized trials comparing low level laser therapy plus antituberculous drugs
with antituberculous drugs alone in people with tuberculosis. DATA COLLECTION AND
ANALYSIS: Two authors independently assessed trial quality and extracted data,
including adverse events. MAIN RESULTS: One randomized controlled trial (130
participants) conducted in India met the inclusion criteria. This trial was
poorly reported, with no information on the generation of allocation sequence or
allocation concealment. The trial report did not provide details on the group
that each of the participants were randomized into or which group those
participants that left the trial were from. This precluded the use of its data on
time to sputum conversion and other outcome measures for analysis. AUTHORS’
CONCLUSIONS: The use of low level laser therapy for treating tuberculosis is
still not supported by reliable evidence. Researchers need to focus on conducting
well-designed randomized controlled trials to justify the continued participation
of volunteers for studies of this experimental intervention.
Techniques for pelvic surgery in subfertility. Ahmad G, Watson A, Vandekerckhove P, Lilford R. Cochrane Database Syst Rev. 2006 Apr 19;(2):CD000221.
BACKGROUND: Since the introduction of in-vitro fertilisation (IVF) tubal surgery
has been less frequently undertaken as a technique to improve fertility in women
with damaged fallopian tubes. There are various surgical techniques that can be
used to repair blocked or damaged fallopian tubes. OBJECTIVES: To evaluate the
role of tubal surgery in the management of tubal infertility and to evaluate
surgical techniques for the treatment of tubal infertility. SEARCH STRATEGY: This
review has drawn on the search strategy developed for the Menstrual Disorders and
Subfertility Group. We identified relevant trials from the Cochrane Menstrual
Disorders and Subfertility Group Specialised Register (searched up to July 2005)
and Cochrane Central Register of Controlled Trials (CENTRAL). The following
databases were searched using the OVID platform: 1. MEDLINE (1966 to July 2005);
2. EMBASE (1980 to July 2005). SELECTION CRITERIA: All randomised controlled
trials investigating the following topics on infertility surgery technique as
follows were included.1) The role of infertility surgery versus no treatment.2)
The role of infertility surgery versus alternative treatments.3) The role of
magnification.4) The role of the CO2 laser at infertility surgery. 5) The role of
operative laparoscopy to perform infertility surgery. 6) Any other intervention
regarding surgical technique investigated by RCT. DATA COLLECTION AND ANALYSIS:
Data were extracted independently by the first two authors. Differences of
opinion were recognised and resolved by consensus.Two by two tables were
generated for each trial for the dichotomous outcome of pregnancy and the effects
on pregnancy rate of each study is expressed as an odds ratio with 95% confidence
intervals. MAIN RESULTS: Seven randomised control trials were identified. No RCTs
comparing infertility surgery versus no treatment or alternative treatments were
found. There was no RCT found investigating the use of magnification for tubal
surgery. There was no evidence for or against the use of a CO2 laser compared
with standard techniques for adhesiolysis (OR for pregnancy 1.07, 95% CI 0.40 to
2.87) or salpingostomy (OR for pregnancy 1.38, 95% CI 0.47 to 4.05) from two
RCTs. One RCT randomised women for salpingostomatolysis by laparotomy and
laparoscopy using the classic approach or the one suture technique. There was no
evidence of benefit or disadvantage when laparoscopy was compared to laparotomy.
The OR for bilateral tubal patency was 1.32 (95% CI 0.55 to 3.22) and unilateral
tubal patency OR was 0.82 (95% CI 0.29 to 2.29). The pregnancy rate was not
reported. There was no evidence of benefit or disadvantage from two RCTs
assessing the use of a prosthesis at salpingostomy compared with non-use
(combined odds of pregnancy (term) in group using the prosthesis as compared to
the control (OR for pregnancy at term 1.17, 95% CI 0.47 to 2.93). There was no
evidence of benefit or disadvantage difference in one RCT comparing Cuff versus
Bruhat technique for salpingostomy One RCT compared two methods of salpingostomy
(OR for pregnancy rate ( intrauterine) 1.02, 95% CI 0.22 to 4.61). One RCT showed
no evidence of benefit or disadvantage for the use of thermocoagulation or
electrocoagulation at adhesiolysis, odds for pregnancy rate between the two
groups OR 0.87 (95% CI 0.51 to 1.46). AUTHORS’ CONCLUSIONS: From these limited
data there is no evidence of benefit or disadvantage of tubal surgery versus no
treatment or alternative treatments. Likewise there is no evidence of advantage
or disadvantage of using microsurgery over standard techniques; laparoscopic
approach over laparotomy; the use of CO2 laser; or electrocoagulation over
thermocoagulation. Randomised controlled trials should be undertaken to determine
the role of tubal surgery versus no treatment or alternative treatments.
Randomised controlled trials should be undertaken to determine the role at tubal
surgery of magnification, laparoscopic approach, the use of lasers or
Laser evoked potentials in primary headaches: a possible clinical or research tool? Valeriani M, Le Pera D, Vigevano F. Suppl Clin Neurophysiol. 2006;58:209-20.
Coherent excitation of vibrational modes in metallic nanoparticles. Hartland GV. Annu Rev Phys Chem. 2006;57:403-30.
Excitation of metal nanoparticles with subpicosecond laser pulses causes a rapid
increase in the lattice temperature, which can impulsively excite the phonon
modes of the particle that correlate with the expansion coordinates. The
vibrational periods depend on the size, shape, and elastic constants of the
particles. Thus, time-resolved spectroscopy can be used to examine the material
properties of nanometer-sized objects. This review provides a brief overview of
the steady-state and time-resolved electronic spectroscopy of metal particles,
which is important for understanding why vibrational motion appears in transient
absorption traces. I also describe how the vibrational modes observed in the
experiments are assigned, and what information can be obtained from the
measurements. Our work has been mainly concerned with noble metal particles (gold
and silver) in aqueous solution. The different shapes that have been examined to
date include spheres, rods, and triangles, all with different sizes.
The role of assisted hatching in in vitro fertilization: a review of the literature. A committee opinion. Practice Committee of the Society for Assisted Reproductive Technology; Practice Committee of the American Society for Reproductive Medicine. Fertil Steril. 2006 Feb;85(2):544-6.
Laser versus intense pulsed light: Competing technologies in dermatology. Ross EV. Lasers Surg Med. 2006 Apr;38(4):261-72.
Lasers have been competing with non-laser intense pulsed light (IPL) sources in
the cosmetic arena over the past 10 years. Initially IPLs were somewhat
cumbersome and accepted by a minority of “serious” practitioners. Recently,
however, the popularity of full-face visible light skin rejuvenation, enhanced
engineering of IPLs, and favorable cost versus many lasers, have lead to a
proliferation of IPL devices. No longer a stepchild in the rejuvenation market,
IPLs may overtake lasers as the devices of choice among most physicians. We
review the pros and cons of lasers and IPLs within the context of design, cost,
and other practical concerns for a typical office-based practice. Copyright 2006
Recent progress in ultrafast X-ray diffraction. Bargheer M, Zhavoronkov N, Woerner M, Elsaesser T. Chemphyschem. 2006 Apr 10;7(4):783-92.
X-ray diffraction with femtosecond time-resolution represents a direct probe of
ultrafast structural changes in condensed matter. The generation of ultrashort
X-ray pulses in laser-driven plasma and/or accelerator-based sources has made
substantial progress, and has allowed for studies of transient structures with an
unprecedented accuracy. Herein, recent work on transient crystalline structures
is reviewed, with the focus on laser-based experiments.
Lasers in periodontics: a review of the literature. Cobb CM. J Periodontol. 2006 Apr;77(4):545-64.
BACKGROUND: Despite the large number of publications, there is still controversy
among clinicians regarding the application of dental lasers to the treatment of
chronic periodontitis. The purpose of this review is to analyze the peer-reviewed
research literature to determine the state of the science concerning the
application of lasers to common oral soft tissue problems, root surface
detoxification, and the treatment of chronic periodontitis. METHODS: A
comprehensive computer-based search combined the following databases into one
search: Medline, Current Contents, and the Cumulated Index of Nursing and Allied
Health. This search also used key words. In addition, hand searches were done for
several journals not cataloged in the databases, and the reference lists from
published articles were checked. All articles were considered individually to
eliminate non-peer-reviewed articles, those dealing with commercial laser
technology, and those considered by the author to be purely opinion articles,
leaving 278 possible articles. RESULTS: There is a considerable conflict in
results for both laboratory studies and clinical trials, even when using the same
laser wavelength. A meaningful comparison between various clinical studies or
between laser and conventional therapy is difficult at best and likely impossible
at the present. Reasons for this dilemma are several, such as different laser
wavelengths; wide variations in laser parameters; insufficient reporting of
parameters that, in turn, does not allow calculation of energy density;
differences in experimental design, lack of proper controls, and differences in
severity of disease and treatment protocols; and measurement of different
clinical endpoints. CONCLUSIONS: Based on this review of the literature, there is
a great need to develop an evidence-based approach to the use of lasers for the
treatment of chronic periodontitis. Simply put, there is insufficient evidence to
suggest that any specific wavelength of laser is superior to the traditional
modalities of therapy. Current evidence does suggest that use of the Nd:YAG or
Er:YAG wavelengths for treatment of chronic periodontitis may be equivalent to
scaling and root planing (SRP) with respect to reduction in probing depth and
subgingival bacterial populations. However, if gain in clinical attachment level
is considered the gold standard for non-surgical periodontal therapy, then the
evidence supporting laser-mediated periodontal treatment over traditional therapy
is minimal at best. Lastly, there is limited evidence suggesting that lasers used
in an adjunctive capacity to SRP may provide some additional benefit.
Laser-microdissection for cell type- and compartment-specific analyses on genomic and proteomic level. Fink L, Kwapiszewska G, Wilhelm J, Bohle RM. Exp Toxicol Pathol. 2006 Jun;57 Suppl 2:25-9. Epub 2006 Apr 11.
Morphological study and identification of cell differentiation within tissues are
the basis for assessment of physiological and pathological processes. Applying
molecular techniques, the analysis of tissue homogenates may lead to masking of
genetic deviations or expression changes of an individual cell type by the bulk
of surrounding cells. To overcome the tissue heterogeneity, cells have to be
isolated selectively. Therefore, microdissection techniques were developed making
retrieval of target cells simple, rapid and precise. Presenting an overview of
our approaches, it is demonstrated that single cell isolation is often
preconditional for the investigation of splicing isoform expression. To reveal
gene regulation combining microdissection of few cells and real-time RT-PCR
allows to determine relative mRNA expression in a cell type-specific manner, even
after immunofluorescence staining of target cells. Combination with RNA
preamplification techniques and micro arrays results in cell type- or
compartment-specific expression profiles that especially differ from those of
tissue homogenates when minor represented cell types are investigated. For
proteomic biomarker screening, the application of mass spectrometry techniques
(SELDI/MALDI TOF) turned out to be feasible in combination with microdissected
minute amounts of tissues. However, further identification of marker peaks still
needs a remarkable effort. Strategies to deal with this problem are presented. In
consequence, the isolation of cells or cell types allows a more accurate
investigation of complex tissues and gives deeper insight to regulation processes
and crosstalk of the respective cells.
The role of alternative and natural agents, cryotherapy, and/or laser for management of alimentary mucositis. Migliorati CA, Oberle-Edwards L, Schubert M. Support Care Cancer. 2006 Jun;14(6):533-40. Epub 2006 Mar 30.
GOALS OF WORK: To review the literature and update the current guidelines of
alternative/natural agents, cryotherapy, and/or laser therapy in the management
of alimentary mucositis (AM). MATERIALS AND METHODS: The original guidelines
developed by the Multinational Association for Supportive Care in Cancer
(MASCC)/International Society for Oral Oncology (ISOO) mucositis study group were
the basis for this study. A medical librarian conducted an initial Medline search
to identify research articles published between 2002 and 2005 in English
language. A search term combination that included stomatitis, mucositis, mucous
membrane, neoplasm, lasers, complimentary therapies, amino acids, antioxidants,
vitamins, minerals, plant extracts, and cryotherapy was conducted. This initial
search identified articles with a strong scientific methodology that included
both preclinical and clinical research. Using standardized scoring forms, authors
reviewed and scored individual articles. A consensus result of the review was
achieved in a meeting of reviewers in June of 2005. RESULTS: The initial search
identified a total of 167 new articles. Of these, 14 were selected and reviewed:
alternative/natural therapy (one preclinical study); cryotherapy (four clinical
studies); lasers (two clinical studies); and alternative/natural agents (seven
clinical studies). A new guideline could be established for the use of
cryotherapy in the management of AM in hematopoietic stem cell transplant (HSCT)
patients receiving melphalan in the conditioning phase. CONCLUSION: The rapid
progress in the understanding of AM created a need for new prevention and
management protocols. Frequent literature review is now necessary to identify
agents and protocols being developed in this important area of supportive care in
A review of lasers and light sources in the treatment of acne vulgaris. Ortiz A, Van Vliet M, Lask GP, Yamauchi PS. J Cosmet Laser Ther. 2005 Jun;7(2):69-75.
There are various treatment modalities for acne vulgaris including topical and
oral therapy as well as microdermabrasion and chemical peels. Recently, there has
been an emergence of novel laser and light sources as a means for treating acne
vulgaris. This article will review the advances of laser and light sources in the
treatment of acne vulgaris.
[Structure of mitochondria and activity of their respiratory chain in subsequent generations of yeast cells exposed to He-Ne laser light] [Article in Russian] Manteĭfel’ VM, Karu TI. Izv Akad Nauk Ser Biol. 2005 Nov-Dec;(6):672-83.
The data on the effect of He-Ne laser light (lambda = 632.8 nm) on mitochondria
of yeasts in late log phase were reviewed. The qualitative analysis of the
ultrathin sections of cells demonstrated a nonuniform thickness of the giant
branched mitochondria typical for budding yeasts. Exposure to a dose of 460 J/m@2
accelerated cell proliferation, activated respiratory chain enzymes (cytochrome c
oxidase and NADH dehydrogenase), and also changed the microstructure of the giant
mitochondria–much of the narrow regions of the mitochondrial tube with sections
< or = 0.06 microm2 were dilated (while no signs of organelle damage were
observed). Relative surface area of the cristae increased in such mitochondria,
which can be due to the activation of their respiration and ATP synthesis. The
number of associations between mitochondria and endoplasmic reticulum increased
in cells in early log phase, which reflects high capacity of mitochondria to
absorb Ca2+. Altered giant mitochondria configuration can increase the efficiency
of both energy transfer and Ca2+ distribution in the cytoplasm.
Thermally induced injury and heat-shock protein expression in cells and tissues. Rylander MN, Feng Y, Bass J, Diller KR. Ann N Y Acad Sci. 2005 Dec;1066:222-42.
Heat-shock proteins (HSPs) are critical components of a cell's defense mechanism
against injury associated with adverse stresses. Initiating insults, such as
elevated or depressed temperature, diminished oxygen, and pressure, increase HSP
expression and can protect cells against subsequent, otherwise lethal, insults.
Although HSPs are very beneficial to the normal cell, cancer cells can also use
HSPs in response to stresses associated with various therapies (hyperthermia,
chemotherapy, radiation), mitigating injury incurred by these treatments.
Hyperthermia is a common treatment option for prostate cancer. HSPs can be
induced in regions of the tumor where temperatures are insufficient to cause
lethal thermal necrosis. Elevated HSP expression can enhance tumor cell viability
and impart increased resistance to subsequent chemotherapy and radiation
treatments, thereby promoting tumor recurrence. An understanding of the
structure, function, and thermally stimulated HSP kinetics and cell injury for
prostate cancer cells is essential to designing effective hyperthermia protocols.
Measured thermally induced cellular HSP expression and injury data can be
employed to develop a treatment planning model for optimization of the tissue
response to therapy based on accurate prediction of the HSP expression and cell
Laser treatment of symptomatic benign prostatic hyperplasia. Elzayat EA, Elhilali MM. World J Urol. 2006 Sep;24(4):410-7. Epub 2006 Mar 4.
The treatment of lower urinary symptoms secondary to benign prostatic hyperplasia
(BPH) after failure of medical therapies remains controversial for most urologic
surgeons. The complications of traditional surgery are the driving force behind
the development of several minimally invasive treatments of symptomatic BPH.
Laser prostatectomy is one of the most investigated such modalities. In this
article we reviewed the results of the most common types of lasers used in
Laser imaging and computer-aided design and computer-aided manufacture in prosthetics and orthotics. Spaeth JP. Phys Med Rehabil Clin N Am. 2006 Feb;17(1):245-63.
Although Hanger Orthopedic Group, Inc., has been developing clinical protocols
for its INSIGNIA scanner for more than 2 years, there are many applications that
are currently in development and will be released over the next 2-year period
after this publication. It is the goal of Hanger Orthopedic Group, Inc., to
replace all plaster casting procedures with the laser scan and move toward a
paperless environment where all images and documents are passed through its
virtual network. INSIGNIA currently has five major production centers throughout
the United States, which support more than 600 INSIGNIA certified clinicians.
These clinicians staff more than 600 clinics in North America, all under the
Hanger company name. The central fabrication service and the central design
center processes hundreds of shapes per day (Fig. 27). So that any clinician in
the field can use the expertise of the central designers and central fabricators
to help with overflow or problems they might be having, the network that exists
within Hanger is tied together and enhanced by INSIGNIA. Through virtual
modification and centralization of these services, each patient receives the
virtual collaboration of several clinicians with a total of years of experience.
INSIGNIA has enhanced the patient experience. The enhancement is not only in
removing the plaster from the process, but also in exposing each patient to the
team of prosthetic experts working collaboratively behind the scenes. The
rehabilitation industry continues to be bombarded with compliance paperwork and
justifications. The INSIGNIA scan and resulting measurement reports give inherent
strength to justifications based on volume change, surgical revisions, or tissue
change. The files are kept in a data warehouse where they are vaulted and
preserved presumably forever. Also, any of the shape graphics or measurement
instruments can be printed into a discrete report that can become part of the
patient's permanent record. Many physicians receive update letters from their
orthotic and prosthetic clinician with a status update before and after treatment
of their patient. This update includes a descriptive narrative, a printout of the
pertinent metrics, a printout of the scan graphic, and often a digital image of
the patient wearing the device (Fig. 28). The network is HIPAA compliant, and all
private health information is held in tight security. If a practitioner does not
have a HIPAA agreement in place with Hanger Orthopedic Group, Inc., and would
like one, or ifa practitioner would like to have an INSIGNIA representative call
or visit with more information, the practitioner is encouraged to call
1-800-4-HANGER and request an INSIGNIA in-service or visit INSIGNIA on the web at
Raman microspectroscopy: a noninvasive tool for studies of individual living cells in vitro. Notingher I, Hench LL. Expert Rev Med Devices. 2006 Mar;3(2):215-34.
There is an increasing need for noninvasive methods that are able to monitor
individual live cells in vitro, including in vitro testing of chemicals and
pharmaceuticals, monitoring the growth of engineered tissues and the development
of cell-based biosensors. Raman spectroscopy is a pure optical technique based on
inelastic scattering of laser photons by molecular vibrations of biopolymers,
which provide a chemical fingerprint of cells or organelles without fixation,
lysis or the use of labels and other contrast-enhancing chemicals. Changes in
cells during the cell cycle, cell death, differentiation or during the
interaction with various chemicals or materials involve biochemical changes that
can be measured with high spatial ( approximately 300 nm) and temporal (seconds
to minutes) resolution. The latest technological developments, especially
high-sensitivity charged coupled detectors and high-power near-infrared lasers,
have spurred the growth of Raman microspectroscopy towards being a well
established analytical tool. This review covers the recent applications of this
technique, including studies of individual cells, both pro- and eukaryotes, and
emphasizes the potential impact on modern scientific endeavors, such as tissue
engineering and drug discovery.
Light scattering studies of proteins under compression. Banachowicz E. Biochim Biophys Acta. 2006 Mar;1764(3):405-13. Epub 2006 Feb 9.
The scattering techniques are very convenient and effective in investigation of
the shape, size and interactions of biological molecules close to their natural
states in solution. However, it seems that from among a wide spectrum of
scattering techniques, the light scattering ones have been relatively rarely used
for the study of proteins under elevated hydrostatic pressure. This paper gives a
brief description of the well developed possibilities of this technique for
potential applications in the study of dissociation, aggregation and structural
changes in proteins under compression. A short review of the already known
applications is also given. Finally, the high-pressure dynamic light scattering
results obtained by author on the lysozyme solution are shown and discussed.
[CO2 laser therapy of verrucous epidermal nevus] [Article in French] Thual N, Chevallier JM, Vuillamie M, Tack B, Leroy D, Dompmartin A. Ann Dermatol Venereol. 2006 Feb;133(2):131-8.
INTRODUCTION: Verrucous epidermal nevus are benign epidermal hyperplasias. Their
treatments are disappointing because of recurrences and anaesthetic scars. The
aim of this study was to evaluate the efficacy of continuous carbon dioxide laser
in the treatment of verrucous epidermal nevus. MATERIAL AND METHODS: It was a
retrospective study concerning all patients treated for epidermal verrucous nevus
by carbon dioxide laser from 1991 to 2003. Several criteria were evaluated by the
patients, a dermatologist and a staff (external observers). Aesthetic result,
recurrences, pain due to treatment and global result were evaluated by the
patients when they came back. RESULTS: Twenty-one patients (12 F and 9 M), medium
age 20.4, were evaluated with a 40.4 months follow-up (7 to 165 months). The
epidermal verrucous nevus was situated on the neck or on the head for 62% of them
(n = 13). Among these 21 patients, 86% (n = 19) estimated their skin as "cured"
or "nearly normal" or "much improved". The rate was the same for the
dermatologist. As for the staff, thanks to photos, only 53% of results were
satisfying. The recurrences were never complete, but moderate in 38% of patients.
Five patients, medium age 12,5, had hypertrophic scars. Among them, three were
only partially hypertrophic. DISCUSSION: A literature review has been made. Our
satisfaction rates (nearly 90%) were slightly higher than other studies rates
using carbon dioxide laser (74%) or other types of lasers (87%). The medium
follow-up was longer than the one of other laser CO2 studies (26.7 months) or
other lasers studies' (15.8 months). This study shows that continuous wave carbon
dioxide laser is an easy and effective treatment of verrucous epidermal nevus.
Aesthetic results are satisfying but moderate recurrences often occur. To prevent
hypertrophic scars, we suggest to exclude teenagers.
Characteristics of several NIR tuneable diode lasers for spectroscopic based gas sensing: a comparison. Weldon V, McInerney D, Phelan R, Lynch M, Donegan J. Spectrochim Acta A Mol Biomol Spectrosc. 2006 Apr;63(5):1013-20. Epub 2006 Feb 21.
Tuneable laser diodes were characterized and compared for use as tuneable sources
in gas absorption spectroscopy. Specifically, the characteristics of monolithic
widely tuneable single frequency lasers, such as sampled grating distributed
Bragg reflector laser and modulated grating Y-branch laser diodes, recently
developed for optical communications, with operating wavelengths in the 1,520
emitting at 935 nm. Characteristics investigated include side-mode suppression
ratio, ease of tuning, tuning range, spectral emission linewidth, frequency
stability and wavelength modulation. While some characteristics differ
significantly across the range of lasers, each device has a number of useful
intrinsic qualities for gas sensing. Specifically, the modulated grating Y laser
and the sampled grating DBR laser have wide quasi-continuous tuneability (30-40
nm) and display relatively low residual amplitude noise when grating-modulated in
a harmonic detection scheme. They are particularly suitable for multi-gas
sensing. ECLs are also capable of wide quasi-continuous tuneability (100 nm) but
their architecture renders them unsuitable for gas sensing application outside a
controlled laboratory environment. DFB devices are by far the easiest with which
to work but their modest tuneability (4 nm maximum by temperature) almost
invariably limits their use to single gas sensing applications.
[Scanning laser polarimetry using the GDx VCC apparatus as a promising method in glaucoma screening] [Article in Czech] Rozprávková A. Cesk Slov Oftalmol. 2006 Jan;62(1):59-69.
Age-related macular disease: how to assess the retina using scanning laser techniques? Bellmann C, Kabanarou SA, Sahel JA, Rubin GS, Fitzke FW. Aging Clin Exp Res. 2005 Dec;17(6):435-44.
Age-related macular disease (AMD) is the leading cause of legal blindness among
the elderly in Western nations. The magnitude of the problem will undoubtedly
grow, as age is a significant risk factor and the number of people aged 65 and
over is projected to increase. The most frequent cause of severe visual loss
associated with AMD is irreversible degeneration of the overlying neurosensory
retina, caused by the growth of choroidal neovascularization or, alternatively,
the development of geographic atrophy of the retinal pigment epithelium. Today,
we are able to image the human retina in vivo. Recently developed imaging
techniques provide better assessment of retinal pathology than conventional
ophthalmoscopy alone. This overview presents the most recent devices available
for retinal imaging, which mainly exploit laser technology such as scanning laser
ophthalmoscopy. Its basic principles, as well as its characteristics for imaging
and functional assessment of the retina, are described. Lastly, potential
benefits for clinical routine, rehabilitation strategies in AMD, and future
research aspects are discussed.
Basic concepts in plasma accelerators. Bingham R. Philos Transact A Math Phys Eng Sci. 2006 Mar 15;364(1840):559-75.
In this article, we present the underlying physics and the present status of high
gradient and high-energy plasma accelerators. With the development of compact
short pulse high-brightness lasers and electron and positron beams, new areas of
studies for laser/particle beam-matter interactions is opening up. A number of
methods are being pursued vigorously to achieve ultra-high-acceleration
gradients. These include the plasma beat wave accelerator (PBWA) mechanism which
uses conventional long pulse ( approximately 100 ps) modest intensity lasers (I
approximately 10(14)-10(16) W cm(-2)), the laser wakefield accelerator (LWFA)
which uses the new breed of compact high-brightness lasers (<1 ps) and
intensities >10(18) W cm(-2), self-modulated laser wakefield accelerator (SMLWFA)
concept which combines elements of stimulated Raman forward scattering (SRFS) and
electron acceleration by nonlinear plasma waves excited by relativistic electron
and positron bunches the plasma wakefield accelerator.In the ultra-high intensity
regime, laser/particle beam-plasma interactions are highly nonlinear and
relativistic, leading to new phenomenon such as the plasma wakefield excitation
for particle acceleration, relativistic self-focusing and guiding of laser beams,
high-harmonic generation, acceleration of electrons, positrons, protons and
photons. Fields greater than 1 GV cm(-1) have been generated with monoenergetic
particle beams accelerated to about 100 MeV in millimetre distances recorded.
Plasma wakefields driven by both electron and positron beams at the Stanford
linear accelerator centre (SLAC) facility have accelerated the tail of the beams.
Are CO2 laser evoked potentials a specific marker of migraine? Valeriani M. Funct Neurol. 2005 Oct-Dec;20(4):201-7.
Although neurophysiological studies have made a considerable contribution to
understanding of migraine pathophysiology, the diagnosis of migraine continues to
be based on clinical examination of the patient, which also includes careful
history taking and a search for neurological signs. Indeed, no instrumental
technique has ever disclosed specific features in migraineurs, able to
distinguish them from healthy subjects or from patients with non-migraine
headache. CO2 laser evoked potentials (LEPs) have been used in migraine research
in the past three years, proving very useful for demonstrating functional
abnormalities of the central nociceptive system which might be linked to the
pathophysiological mechanisms of this disease. However, like other
neurophysiological methods, LEP recording in migraineurs has not revealed
abnormalities specific enough to allow diagnosis of migraine in individual
From coagulation to enucleation: the use of lasers in surgery for benign prostatic hyperplasia. Wilson LC, Gilling PJ. Nat Clin Pract Urol. 2005 Sep;2(9):443-8.
The application of lasers for the treatment of benign prostatic hyperplasia has
evolved over the past 15 years. Early-generation neodymium:yttrium aluminum
garnet lasers were used to coagulate and ablate prostatic tissue, but significant
postoperative irritative symptoms and high reoperation rates meant that this
approach did not seriously challenge the status quo for long. Ablative techniques
have recently become popular again with the marketing of the newer-generation,
higher-power potassium titanyl phosphate and holmium lasers. Although short-term
data are encouraging, there are no comparative trials of significant duration, so
it is not yet possible to draw conclusions with regard to efficacy and
durability. The holmium laser can also be used as an incisional and dissecting
tool that allows resection or enucleation of whole lobes of the prostate,
mimicking the action of the index finger in open prostatectomy. The safety,
efficacy, durability and cost-effectiveness of the holmium laser have been shown
in well-designed randomized controlled trials.
Photorefractive effect of ferroelectric liquid crystals. Sasaki T. Chem Rec. 2006;6(1):43-51.
This paper reviews our recent work on the photorefractive effect of ferroelectric
liquid crystals (FLCs). The photorefractive effect is defined as the optical
modulation of the refractive index of a medium as a result of a variety of
processes. The interference of two laser beams in a photorefractive material
establishes a refractive index grating. This phenomenon enables the creation of
different types of photonic applications. FLCs exhibit fast electric field
response, and the orientation of the molecular axis of FLCs changes its direction
according to the change in direction of the spontaneous polarization (Ps). When
two laser beams interfere in a photoconductive FLC, an orientational grating is
formed. The mechanism of the formation of the grating is based on the response of
the Ps to the photoinduced internal electric field. The time of formation of the
refractive index grating is significantly shorter in FLC materials. (c) 2006 The
Japan Chemical Journal Forum and Wiley Periodicals, Inc.
Laser and light therapies for acne rosacea. Butterwick KJ, Butterwick LS, Han A. J Drugs Dermatol. 2006 Jan;5(1):35-9.
Acne rosacea is a multifactorial, somewhat mercurial disorder that can be a
challenge to control with standard pharmacologic agents. Laser and light sources
have been increasingly utilized, particularly for control of the generalized
erythema, flushing, and telangiectasia of rosacea. This paper will review the
clinical studies presented in the literature specifically treating patients with
rosacea. Long-pulsed dye lasers and intense pulsed light devices can offer
patients effective treatment without the purpura of short-pulsed dye lasers.
Long-term efficacy has not been studied but maintenance therapy may be necessary
to control the vascular manifestations of this disease.
[Complications of refractive excimer laser surgery] [Article in German] Knorz MC. Ophthalmologe. 2006 Mar;103(3):192-8.
In surface ablation, haze is the most frequent complication.After LASIK,
microkeratome-related complications are rare today and usually resolve without
sequelae, provided no ablation was done. Postoperative flap complications such as
flap slippage usually occur during the first few days after surgery and should be
treated as early whenever present.Interface complications are a new diagnostic
entity as the interface between flap and stroma presents a space where fluid or
cells can accumulate. Diffuse lamellar keratitis usually occurs within the first
few postoperative days and should be treated aggressively to avoid scarring.
Epithelial ingrowth is another rare complication usually requiring treatment.
Corneal hydrops with fluid accumulation in the interface is a very rare but
important phenomenon related to steroid-induced glaucoma but presenting with
false low tonometry readings.Corneal ectasia is extremely rare and in most cases
related to thin stromal beds. However, its pathogenesis is not yet completely
understood, and it may occur in “normal” eyes, too. Dry eye syndrome is the most
frequent complication after LASIK. It is usually benign but may cause significant
visual impairment in rare cases.
[Glaucoma - structural imagery: HRT, GDX, OCT] [Article in French] Renard JP, Giraud JM. J Fr Ophtalmol. 2006 Jan;29(1):64-73.
Confocal scanning laser tomography (HRT), scanning laser polarimetry (GDx VCC),
and optical coherence tomography provide quantitative data of the retinal fiber
layer and optic nerve head. They have become good complementary evaluation tools
for glaucomatous optic neuropathy and their results should be analyzed with
clinical data. Good knowledge of the parameters they analyze and their
limitations are indispensable. To monitor progression of structural involvement,
the analysis programs used need to be validated with prospective clinical
Advances in light curing units and curing techniques: a literature review. Oberholpez G, Botha CT, du Preez IC. SADJ. 2005 Nov;60(10):451-4.
There exists a constant need for a dental curing light that works reliably and
conveniently in the general practitioner’s office and can be used effectively for
all the different curing procedures. Due to the need for improved physical
properties of resin based composites (RBCs) and less stress at the marginal
interface, light curing units (LCUs) experienced significant advances in the past
years. The dental industry has focused on reducing the curing time by developing
higher intensity curing lights and by altering the resin composition and
photo-initiator concentration. As a result the dentist can now choose from a vast
variety of curing lights, light intensities and curing methods. This article
presents a review of the advances in light curing units and curing techniques, as
well as the scientific principles that guided past developments and that will
influence future advances.
Laser treatment of tattoos. Bernstein EF. Clin Dermatol. 2006 Jan-Feb;24(1):43-55.
Tattooing has been around since the early beginnings of modern civilization.
Modern tattoo artists use a myriad of colors to produce striking designs,
resulting in permanent works of body art; however, we humans have been changing
our minds since the beginning of time. Our fickle nature results in the desire to
change what has been placed as a permanent reminder of a friend, spouse, or work
of art. Removing tattoos began with abrasive and destructive measures to destroy
the tattoo, and unfortunately, the skin it was contained in. The discovery of
selective photothermolysis, the ability to selectively remove target structures
without disrupting the surrounding skin, made it at least possible to remove
tattoos without destroying the surrounding skin leaving a scar. Theory predicted
that pulse durations in the nanosecond domain would be optimal for tattoo
removal, and the Q-switched neodymium:yttrium-aluminum-garnet, alexandrite, and
ruby lasers fulfilled this need. Too often, older lasers or intense pulsed light
sources are used to treat tattoos, often with significant scarring. Since the
advent of the Q-switched lasers more than a decade ago, improvement in
tattoo-removal lasers has been incremental. Developments leading to new tattoo
inks, feedback systems to detect the absorbance characteristics of tattoo inks,
dermal clearing agents, and perhaps even shorter pulse-duration lasers should
result in improved results for the future.
Laser therapy for acne. Nouri K, Ballard CJ. Clin Dermatol. 2006 Jan-Feb;24(1):26-32.
Considered the most common skin disorder, acne affects millions of people every
year. This multifactorial condition of the pilosebaceous follicle is a
combination of at least four different primary pathogeneses. In recent years,
acne therapies have been improving, becoming more effective, and targeting one or
more of these causes. Many current therapies have drawbacks involving patient
compliance, systemic toxicities, and bacterial resistance. Lasers are now
established options in the armamentarium to treat acne. The 532-nm potassium
titanyl phosphate laser, 585- and 595-nm pulsed dye lasers, 1450-nm diode laser,
and 1540-nm erbium glass laser have been used with variable efficacy. Lasers may
be best used in combination with other therapies to enhance their results.
Photodynamic therapy has been successful with substances such as 5-aminolevulinic
acid and indocyanine green. Lasers remain viable alternatives for people who may
not desire or be able to use topical or systemic formulations. Drawbacks
associated with lasers include potential pain, skin discoloration, and cost of
treatment. Typically, multiple sessions are required to achieve the desired
results, with future maintenance treatments possible to maintain the outcomes.
With additional clinical trials underway, laser treatment of acne will surely
advance and continue to be optimized in the future.
Laser-mediated photodynamic therapy. Alexiades-Armenakas M. Clin Dermatol. 2006 Jan-Feb;24(1):16-25.
Photodynamic therapy (PDT) has evolved since its inception at the beginning of
the 20th century, when it was defined as an oxygen-dependent reaction between a
photosensitizing dye and light. Photosensitizers and light sources have since
been continually optimized for distinct applications and tissues. Systemic
porphyrins, such as hematoporphyrin, were the first photosensitizers to be used,
mostly to treat tumors. The first light sources used were broad-band, noncoherent
lights, such as quartz, xenon, tungsten, or halogen lamps. The wavelengths of
light chosen were based upon the absorption spectrum of porphyrins: blue because
the largest peak is at 400 nm (the Soret band) and red because of its greater
penetration depth but lesser absorption at 650 nm (a Q band). Systemic
photosensitizers caused prolonged photosensitivity, and broad-band light sources
had limitations and side effects. The development of topical photosensitizers,
such as 5-aminolevulinic acid, and the advent of lasers in recent years have
advanced PDT for cutaneous use. In the 1990s, red lasers were applied to PDT
because of their increased skin penetration despite lesser absorption by
porphyrins. Broad-band blue light and red light have been studied extensively,
the former achieving Food and Drug Administration approval in combination with
topical aminolevulinic acid for the treatment of actinic keratosis in 1997. These
lasers and light sources caused significant side effects, such as discomfort,
erythema, crusting, blistering, and dyspigmentation. The recent application of
the long-pulsed pulsed dye laser (595 nm) after topical aminolevulinic acid
greatly minimized side effects without compromising efficacy. Long-pulsed pulsed
dye laser-mediated PDT has since been shown to be effective in treatment of
actinic keratosis, actinic cheilitis, sebaceous hyperplasia, lichen sclerosus,
and, most recently, acne vulgaris. Finally, intense pulsed light sources have
been introduced to PDT for the treatment of photodamage and acne, offering
advantages of versatility in wavelengths and applications.
Laser treatment of vascular lesions. Railan D, Parlette EC, Uebelhoer NS, Rohrer TE. Clin Dermatol. 2006 Jan-Feb;24(1):8-15.
Laser treatment of vascular lesions remains one of the more common applications
of lasers in dermatology. In fact, lasers have largely become the treatment of
choice for vascular birthmarks such as hemangiomas and port-wine stains and the
definitive treatment of the telangiectatic form of rosacea. The range of
congenital and acquired vascular lesions effectively treated with lasers
continues to expand.
LASER-tissue interactions. Carroll L, Humphreys TR. Clin Dermatol. 2006 Jan-Feb;24(1):2-7.
As new laser devices continue to emerge, it becomes increasingly important for
the clinical dermatologist to understand the basic principles behind their
operation. A fundamental understanding of how lasers interact with tissue will
enable the physician to choose the most appropriate laser for a given clinical
situation. Although the physical laws guiding laser design are vastly complex,
the fundamental principles of laser-tissue interaction can be summarized as they
are applicable to the clinician.
[Fundus autofluorescence examination using a confocal scanning laser ophthalmoscope HRA (Heidelberg Retina Angiograph)] [Article in Polish] Dolar-Szczasny J, Mackiewicz J, Bindewald A, Holz FG, Zagórski Z. Klin Oczna. 2005;107(7-9):544-7.
PURPOSE: To present application of a confocal Scanning Laser Ophthalmoscope
(cSLO) for fundus autofluorescence examination, as a new method of visualization
of retinal pigment epithelium and its possible significance in the diagnosis of
different retinal diseases. MATERIAL AND METHODS: Typical autofluorescence images
in age-related macular degeneration (AMD), Stargardt disease, Best disease and
pattern dystrophies are presented, based on the own experience and literature
data. Autofluorescence images were obtained with a cSLO using an argon laser for
generation of excitation light at 488 nm and a barrier filter >500 nm for the
detection of the emitted signals. RESULTS: A variety of autofluorescence
patterns, associated with the accumulation of lipofuscin in RPE cells, was found
in the above entities. CONCLUSIONS: Presented method of fundus autofluorescence
examination gives new possibilities in studying the pathogenetic mechanisms in
various retinal diseases and may be useful in monitoring the follow-up and the
effects of the treatment.
[Yttrium- Aluminium Garnet Crystal (I)] [Article in Romanian] Cârstocea B, Pascu RA. Oftalmologia. 2005;49(3):3-9.
The Yttrium- Aluminum Garnet Crystal is synthetically obtained and represents the
active medium of the Nd: YAG, Ho: YAG, Er: YAG lasers. These solid state lasers
showed very good results in Ophthalmology, due to their emission in different
regimes (continuous wave or giant short pulses), at different wavelengths (near
IR and starting from it in UV or visible spectre), the ability to focus the
radiation through simple optic systems or the transmission to narrow, hard
accessible spaces using flexible optic fibers. The high efficiency of these
lasers reported in ophthalmology is obtained by the photo-disruptive or thermic
mechanism of the laser beams. This paper introduces the properties of the laser
radiation, the structure and the way the YAG laser works and the applications of
these lasers in Ophthalmology (such as posterior capsulotomy, iridotomy or
trabeculoplasty) as well.
Treatments for unwanted facial hair. Shapiro J, Lui H. Skin Therapy Lett. 2005 Dec-2006 Jan;10(10):1-4.
Twenty-two percent of women in North America have unwanted facial hair, which can
cause embarrassment and result in a significant emotional burden. Treatment
options include plucking, waxing (including the sugar forms), depilatories,
bleaching, shaving, electrolysis, laser, intense pulsed light (IPL), and
eflornithine 13.9% cream (Vaniqa, Barrier Therapeutics in Canada and Shire
Pharmaceuticals elsewhere). Eflornithine 13.9% cream is a topical treatment that
does not remove the hairs, but acts to reduce the rate of growth and appears to
be effective for unwanted facial hair on the mustache and chin area. Eflornithine
13.9% cream can be used in combination with other treatments such as lasers and
IPL to give the patient the best chance for successful hair removal.
Evidence-based review of hair removal using lasers and light sources. Haedersdal M, Wulf HC. J Eur Acad Dermatol Venereol. 2006 Jan;20(1):9-20.
BACKGROUND: Unwanted hair growth remains a therapeutic challenge and there is a
considerable need for an effective and safe treatment modality. OBJECTIVE: From
an evidence-based view to summarize efficacy and adverse effects from hair
removal with ruby, alexandrite, diode, and Nd:YAG lasers and intense pulsed light
(IPL). METHODS: Original publications of controlled clinical trials were
identified in Medline and the Cochrane Library. RESULTS: A total of 9 randomized
controlled (RCTs) and 21 controlled trials (CTs) were identified. The best
available evidence was found for the alexandrite (three RCTs, eight CTs) and
diode (three RCTs, four CTs) lasers, followed by the ruby (two RCTs, six CTs) and
Nd:YAG (two RCTs, four CTs) lasers, whereas limited evidence was available for
IPL sources (one RCT, one CT). Based on the present best available evidence we
conclude that (i) epilation with lasers and light sources induces a partial
short-term hair reduction up to 6 months postoperatively, (ii) efficacy is
improved when repeated treatments are given, (iii) efficacy is superior to
conventional treatments (shaving, wax epilation, electrolysis), (iv) evidence
exists for a partial long-term hair removal efficacy beyond 6 months
postoperatively after repetitive treatments with alexandrite and diode lasers and
probably after treatment with ruby and Nd:YAG lasers, whereas evidence is lacking
for long-term hair removal after IPL treatment, (v) today there is no evidence
for a complete and persistent hair removal efficacy, (vi) the occurrence of
postoperative side-effects is reported low for all the laser systems. CONCLUSION:
The evidence from controlled clinical trials favours the use of lasers and light
sources for removal of unwanted hair. We recommend that patients are
pre-operatively informed of the expected treatment outcome.
Laser treatment of leg veins. Kauvar AN, Khrom T. Semin Cutan Med Surg. 2005 Dec;24(4):184-92.
The development of lasers using deeper-penetrating, near-infrared wavelengths
with millisecond pulse durations and skin-cooling methods has produced safer and
more predictable results for the treatment of leg veins less than 1 mm in
diameter and depth. Recent prospective studies of the near-infrared lasers show
comparable efficacy and side effect profiles to those observed with
sclerotherapy. Treatment of reticular and varicose veins is effective with these
wavelengths but is limited by patient discomfort when compared with
sclerotherapy. Visible light lasers (such as the pulsed dye and KTP) and intense
pulsed-light sources are reproducibly effective only for superficial,
nonarborizing pink-to-red telangiectasia, in the absence of points of proximal
reflux. Because most lower-extremity vascular ectasias comprise a heterogeneous
group of vessel sizes and depths, many patients achieve the best results using a
combination of techniques. This article reviews the fundamentals of laser tissue
interactions for the treatment of leg veins and details the recent clinical
experience with the newer near-infrared devices.
Retinopathy of prematurity: the life of a lifetime disease. Tasman W, Patz A, McNamara JA, Kaiser RS, Trese MT, Smith BT. Am J Ophthalmol. 2006 Jan;141(1):167-74.
PURPOSE: To provide information on retrolental fibroplasias (RLF), later known as
retinopathy of prematurity. DESIGN: Review of the literature on the subject and a
first-person account of what was then RLF by one of the authors (A.P.) who was
involved in the earliest days in research regarding RLF. METHODS: MEDLINE search
on the topics of RLF and retinopathy of prematurity plus a first-person historic
review of original work that dealt with RLF. RESULTS: In 1942, elevated levels of
oxygen were thought to play a major role in the development of the disease; at
that time, no treatment was available. During the lifetime of this disease, other
possible causes have been investigated. These include vitamin E as a prophylaxis
against retinopathy of prematurity and the efficacy of light reduction to prevent
retinopathy of prematurity. It has been shown that the light reduction does not
play a role in reducing the progression of retinopathy of prematurity. Vitamin E
studies were inconclusive; some studies show a positive effect and others do not.
A major advance occurred with the development of the International Classification
of Ophthalmology in 1984, which laid the groundwork for collaborative studies to
determine whether cryotherapy of the avascular zone of retina would reduce the
incidence of blindness in newborn infants, when compared with control subjects.
The study showed that cryotherapy was effective; this was followed by laser
photocoagulation when lasers became portable enough to take to the neonatal
intensive care unit. At the same time, improved surgical techniques moved from
scleral buckling for retinal detachment to vitrectomies (some lens sparing) for
more desperate cases that had progressed to stage 4 and stage 5 retinopathy of
prematurity. Late changes in adults who were born before any treatment and are
now baby boomers ran the gamut from the dragging of the retina in the posterior
pole to retinal detachment, cataract, and myopia. CONCLUSION: Retinopathy of
prematurity is a lifetime disease for which preventive and better treatment
modalities continue to evolve.
[Emerging endoscopic techniques. The arrival of virtual histology] [Article in Spanish] Pellisé M, Llach J, Bordas JM. Gastroenterol Hepatol. 2005 Dec;28(10):641-8.
Endoscopic technology has evolved in such a way that gastroenterologists can now
visualize and store high-resolution images of the gastrointestinal tract. This
has improved the approach to precancerous and cancerous lesions of the
gastrointestinal tract and biliary tree. However, certain difficulties remain,
especially in relation to diagnosis. In the last few years, multiple techniques
have been developed that, using the properties of light, enable an instantaneous
histologic diagnosis to be made while endoscopy is being performed. What has been
called the “optical biopsy” allows highly exact information to be obtained, both
from the morphological and functional point of view. Some of these techniques,
such as chromoendoscopy and magnification, are already being performed in
clinical practice while others are still under investigation. The aim of the
present article is to review the underlying principles and applications of these
Use of lasers and light-based therapies for treatment of acne vulgaris. Mariwalla K, Rohrer TE. Lasers Surg Med. 2005 Dec;37(5):333-42.
Over the last two decades, lasers and light-based therapies have been developed
to treat a wide variety of cutaneous maladies. Given the prevalence and number of
patients who suffer from refractory acne, alternatives to existing care are
constantly sought after. In this review, we discuss the evidence currently
available to justify the use of laser and light-based modalities and conclude
that in combination therapy, such approaches provide a safe and effective
treatment for acne vulgaris. (c) 2005 Wiley-Liss, Inc.
Lasers in veterinary dermatology. Duclos D. Vet Clin North Am Small Anim Pract. 2006 Jan;36(1):15-37, v.
Therapeutic applications of lasers in urology: an update. Fried NM. Expert Rev Med Devices. 2006 Jan;3(1):81-94.
There has been renewed interest in the use of lasers for minimally invasive
treatment of urologic diseases in recent years. The introduction of more compact,
higher power, less expensive and more user-friendly solid-state lasers, such as
the holmium:yttrium-aluminum-garnet (YAG), frequency-doubled neodymium:YAG and
diode lasers has made the technology more attractive for clinical use. The
availability of small, flexible, biocompatible, inexpensive and disposable silica
optical fiber delivery systems for use in flexible endoscopes has also promoted
the development of new laser procedures. The holmium:YAG laser is currently the
workhorse laser in urology since it can be used for multiple soft- and
hard-tissue applications, including laser lithotripsy, benign prostate
hyperplasia, bladder tumors and strictures. More recently, higher power
potassium-titanyl-phosphate lasers have been introduced and show promise for the
treatment of benign prostatic hyperplasia. On the horizon, newer and more
effective photosensitizing drugs are being tested for potential use in
photodynamic therapy of bladder and prostate cancer. Additionally, new
experimental lasers such as the erbium:YAG, Thulium and Thulium fiber lasers, may
provide more precise incision of soft tissues, more efficient laser lithotripsy
and more rapid prostate ablation. This review provides an update on the most
important new clinical and experimental therapeutic applications of lasers in
urology over the past 5 years.
The use of diode lasers in periodontal therapy: literature review and suggested technique. Andreana S. Dent Today. 2005 Nov;24(11):130, 132-5.
Acne, lasers, and light. Ross EV. Adv Dermatol. 2005;21:1-32.
Global gene expression profiling: a complement to conventional histopathologic analysis of neoplasia. Nambiar PR, Boutin SR, Raja R, Rosenberg DW. Vet Pathol. 2005 Nov;42(6):735-52.
Transcriptional profiling of entire tumors has yielded considerable insight into
the molecular mechanisms of heterogeneous cell populations within different types
of neoplasms. The data thus acquired can be further refined by microdissection
methods that enable the analyses of subpopulations of neoplastic cells.
Separation of the various components of a neoplasm (i.e., stromal cells,
inflammatory infiltrates, and blood vessels) has been problematic, primarily
because of a paucity of tools for accurate microdissection. The advent of laser
capture microdissection combined with powerful tools of linear amplification of
RNA and high-throughput microarray-based assays have allowed the transcriptional
mapping of intricate and highly complex networks within pure populations of
neoplastic cells. With this approach, specific “molecular signatures” can be
assigned to tumors of distinct or even similar histomorphology, thereby aiding
the desired objective of pattern recognition, tumor classification, and
prognostication. This review highlights the potential benefits of global gene
expression profiling of tumor cells as a complement to conventional
Lasers in cancer detection and diagnosis research: enabling characteristics with illustrative examples. Alfano S, Wang WB, Gayen SK. Technol Cancer Res Treat. 2005 Dec;4(6):663-73.
The salient properties of laser light and the way light interacts with biological
tissues and molecular constituents of tissues offer possibilities for detection
and diagnosis of cancer. In particular, the wavelength selectivity of tunable
lasers, narrow bandwidth around the selected wavelength, and spectral brightness
enable probing of key molecular constituents of tissues, and endow laser-based
techniques with much desired diagnostic potential. This article presents an
overview of some recent developments in optical imaging and optical biopsy of
different types of cancers, and illustrates the diagnostic role of the color of
Mitochondrial correlation microscopy and nanolaser spectroscopy – new tools for biophotonic detection of cancer in single cells. Gourley PL, Hendricks JK, McDonald AE, Copeland RG, Barrett KE, Gourley CR, Singh KK, Naviaux RK. Technol Cancer Res Treat. 2005 Dec;4(6):585-92.
Currently, pathologists rely on labor-intensive microscopic examination of tumor
cells using century-old staining methods that can give false readings. Emerging
BioMicroNano-technologies have the potential to provide accurate, realtime,
high-throughput screening of tumor cells without the need for time-consuming
sample preparation. These rapid, nano-optical techniques may play an important
role in advancing early detection, diagnosis, and treatment of disease. In this
report, we show that laser scanning confocal microscopy can be used to identify a
previously unknown property of certain cancer cells that distinguishes them, with
single-cell resolution, from closely related normal cells. This property is the
correlation of light scattering and the spatial organization of mitochondria. In
normal liver cells, mitochondria are highly organized within the cytoplasm and
highly scattering, yielding a highly correlated signal. In cancer cells,
mitochondria are more chaotically organized and poorly scattering. These
differences correlate with important bioenergetic disturbances that are hallmarks
of many types of cancer. In addition, we review recent work that exploits the new
technology of nanolaser spectroscopy using the biocavity laser to characterize
the unique spectral signatures of normal and transformed cells. These optical
methods represent powerful new tools that hold promise for detecting cancer at an
early stage and may help to limit delays in diagnosis and treatment.
The use of lasers in the pediatric population. Mariwalla K, Dover JS. Skin Therapy Lett. 2005 Oct;10(8):7-9.
Over the past 2 decades, there have been numerous advances in laser therapy of
birth-marks in the pediatric population. Concerns regarding efficacy, overall
benefit, and side-effects linger. We present our opinion, based upon decades of
clinical experience, on the role of lasers to treat port wine stains, superficial
hemangiomas, and café au lait macules in children.
Anti-infective therapy with an Er:YAG laser: influence on peri-implant healing. Sculean A, Schwarz F, Becker J. Expert Rev Med Devices. 2005 May;2(3):267-76.
In addition to conventional treatment modalities (mechanical and chemical), the
use of lasers has been increasingly proposed for the treatment of periodontal and
peri-implant infections (i.e., cleaning and detoxification of implant surfaces).
Preliminary results from basic studies have pointed to the high potential of the
Erbium-doped: Yttrium, Aluminum and Garnet (Er:YAG) laser. Furthermore,
preliminary clinical data indicate that treatment with this kind of laser may
positively influence peri-implant healing. The aim of this research update is to
evaluate, based on the currently available evidence, the use of an Er:YAG laser
for the treatment of peri-implant infections and to indicate its potential as a
new treatment modality.
Taking advantage of luminescent lanthanide ions. Bünzli JC, Piguet C. Chem Soc Rev. 2005 Dec;34(12):1048-77. Epub 2005 Sep 20.
Lanthanide ions possess fascinating optical properties and their discovery, first
industrial uses and present high technological applications are largely governed
by their interaction with light. Lighting devices (economical luminescent lamps,
light emitting diodes), television and computer displays, optical fibres, optical
amplifiers, lasers, as well as responsive luminescent stains for biomedical
analysis, medical diagnosis, and cell imaging rely heavily on lanthanide ions.
This critical review has been tailored for a broad audience of chemists,
biochemists and materials scientists; the basics of lanthanide photophysics are
highlighted together with the synthetic strategies used to insert these ions into
mono- and polymetallic molecular edifices. Recent advances in NIR-emitting
materials, including liquid crystals, and in the control of luminescent
properties in polymetallic assemblies are also presented. (210 references.).
[Controversy in dermatology--laser therapy and melanocytic nevi] [Article in German] Kerl H, Raulin C, Landthaler M. J Dtsch Dermatol Ges. 2004 Aug;2(8):681-3.
Application of soft tissue modelling to image-guided surgery. Carter TJ, Sermesant M, Cash DM, Barratt DC, Tanner C, Hawkes DJ. Med Eng Phys. 2005 Dec;27(10):893-909. Epub 2005 Nov 3.
The deformation of soft tissue compromises the accuracy of image-guided surgery
based on preoperative images, and restricts its applicability to surgery on or
near bony structures. One way to overcome these limitations is to combine
biomechanical models with sparse intraoperative data, in order to realistically
warp the preoperative image to match the surgical situation. We detail the
process of biomechanical modelling in the context of image-guided surgery. We
focus in particular on the finite element method, which is shown to be a
promising approach, and review the constitutive relationships which have been
suggested for representing tissue during surgery. Appropriate intraoperative
measurements are required to constrain the deformation, and we discuss the
potential of the modalities which have been applied to this task. This technology
is on the verge of transition into clinical practice, where it promises to
increase the guidance accuracy and facilitate less invasive interventions. We
describe here how soft tissue modelling techniques have been applied to
image-guided surgery applications.
Periorbital ablative and nonablative resurfacing. Shook BA, Hruza GJ. Facial Plast Surg Clin North Am. 2005 Nov;13(4):571-82, vii.
Ablative resurfacing using laser systems for facial rejuvenation, especially in
the periorbital areas, has effectively replaced chemical peels. Refined methods
yield outstanding efficacy with significantly fewer side effects as compared with
the prototypical lasers of decades past. Despite these technologic refinements,
the trend toward minimally invasive rejuvenation techniques has placed a
substantial emphasis on the many nonablative modalities available to the
practitioner. Although the clinical efficacy to date has been less with the
nonablative devices, the lack of substantial morbidity has made the devices
marketable to a large population of patients despite their modest results at best
and highly unpredictable results at worst. Numerous options, ablative and
nonablative, are now available for the patient desiring improvement in
Femtosecond lasers in gas phase chemistry. Carley RE, Heesel E, Fielding HH. Chem Soc Rev. 2005 Nov;34(11):949-69. Epub 2005 Sep 29.
This critical review is intended to provide an overview of the state-of-the-art
in femtosecond laser technology and recent applications in ultrafast gas phase
chemical dynamics. Although “femtochemistry” is not a new subject, there have
been some tremendous advances in experimental techniques during the last few
years. Time-resolved photoelectron spectroscopy and ultrafast electron
diffraction have enabled us to observe molecular dynamics through a wider window.
Attosecond laser sources, which have so far only been exploited in atomic
physics, have the potential to probe chemical dynamics on an even faster
timescale and observe the motions of electrons. Huge progress in pulse shaping
and pulse characterisation methodology is paving the way for exciting new
advances in the field of coherent control.
Photoelectron spectroscopy without photoelectrons: twenty years of ZEKE spectroscopy. Cockett MC. Chem Soc Rev. 2005 Nov;34(11):935-48. Epub 2005 Sep 5.
Zero Kinetic Energy (ZEKE) spectroscopy, originally developed as a high
resolution form of photoelectron spectroscopy, promised a means to the
unambiguous determination of ionic (ro)vibrational states. Since its original
development, it has spawned numerous methodological offshoots and has become one
of the default methods of choice for high resolution spectroscopy of the ion.
This tutorial review describes the historical development of the method, provides
some insight into how it works and assesses the impact of the technique by
reviewing some of the highlights of the past 20 years as well as some of the more
recent developments and applications.
Quantum cascade semiconductor infrared and far-infrared lasers: from trace gas sensing to non-linear optics. Duxbury G, Langford N, McCulloch MT, Wright S. Chem Soc Rev. 2005 Nov;34(11):921-34. Epub 2005 Apr 19.
The Quantum cascade (QC) laser is an entirely new type of semiconductor device in
which the laser wavelength depends on the band-gap engineering. It can be made to
operate over a much larger range than lead salt lasers, covering significant
parts of both the infrared and submillimetre regions, and with higher output
power. In this tutorial review we survey some of the applications of these new
lasers, which range from trace gas detection for atmospheric or medical purposes
to sub-Doppler and time dependent non-linear spectroscopy.
Laser microdissection in clinical cardiovascular research. Chimenti C, Pieroni M, Russo A, Sale P, Russo MA, Maseri A, Frustaci A. Chest. 2005 Oct;128(4):2876-81.
Laser microdissection (LMD) is an accurate and fast method to procure pure
populations of cells from complex, heterogeneous tissues under direct microscopic
visualization. It can be applied to a wide range of cell preparation, including
paraffin-embedded material. The morphology of the captured cells is retained, and
DNA, RNA, and proteins can be extracted for molecular analysis. The potential
applications of LMD to human cardiovascular research are multiple, including
viral/autoimmune myocarditis and arteritis, atherosclerotic lesions, and
myocardial and vascular cell proliferation and death. Molecular and genetic
analysis of LMD-procured cells in cardiac and vascular tissues may provide a
better understanding of several cardiac diseases.
Treating vascular lesions. Astner S, Anderson RR. Dermatol Ther. 2005 May-Jun;18(3):267-81.
The treatment of acquired vascular lesions is one of the most commonly requested
and performed cutaneous laser procedures. Furthermore, every year, 40,000
children are born in the United States each with congenital vascular lesions and
malformations. Laser treatment of vascular lesion is based on the principle of
selective photothermolysis, conceived in the 1980s. A variety of different lasers
and light sources have since been used in the treatment of vascular lesions:
lasers with wavelengths between green and yellow, near infrared lasers, and
broadband light sources. Despite limitations, this remains the treatment of
choice today. This publication addresses acquired and congenital vascular lesions
as different entities and proposes a separation of vascular lesions into those
that can easily be treated from those where clearance is difficult. Different
treatment modalities and the various endpoints of individual vascular lesions
will be discussed.
Ablative treatment of photoaging. Railan D, Kilmer S. Dermatol Ther. 2005 May-Jun;18(3):227-41.
Despite the burgeoning options available for skin rejuvenation, the benefits of
laser skin resurfacing in trained hands remains unequaled. This article will
review the preoperative evaluation, lasers and techniques used, postoperative
course, and possible complications.
Laser hair removal. Wanner M. Dermatol Ther. 2005 May-Jun;18(3):209-16.
Since 1996, there have been numerous advances in hair laser removal that utilize
melanin as a chromophore. All of the devices on the market may be used in
patients with light skin (phototypes I-III) and yield hair reduction near 75%.
The ruby (694 nm) laser, alexandrite (755 nm) laser, and diode (810 nm) laser, as
well as intense pulsed light are commonly used devices for hair laser removal.
The long-pulsed Nd:YAG (1064 nm) laser represents the safest device for hair
removal in dark-skinned patients because of its long wavelength, although the
diode laser, alexandrite laser, and intense pulse light may be used. For
treatment of light hair, combination radiofrequency and optical devices as well
as photodynamic therapy are under investigation.
Visible light treatment of photoaging. Dierickx CC, Anderson RR. Dermatol Ther. 2005 May-Jun;18(3):191-208.
Recently, a number of new devices have been developed specifically to improve the
visible signs of aging in a noninvasive way. These include visible or
near-infrared lasers, intense pulsed light sources (IPL), light-emitting diode
(LED), and radiofrequency devices. This paper reviews the use of visible light
sources and examines the attributes of specific systems for noninvasive skin
The choroidal circulation assessed by laser-targeted angiography. Hirata Y, Nishiwaki H. Prog Retin Eye Res. 2006 Mar;25(2):129-47. Epub 2005 Oct 12.
The choroid plays an important role in supplying nutrients to and removing waste
products from the outer region of the retina. Abnormal choroidal blood flow can
disrupt normal retinal function and lead to alterations in visual function.
Visualization of the choriocapillaris in vivo is a great challenge to
understanding its normal physiology and involvement in the disease process.
Laser-targeted angiography (LTA) is a relatively new method used to visualize and
analyze the choroidal circulation. Carboxyfluorescein (CF), encapsulated in
heat-sensitive liposomes, is released locally in the choroid through the
application of a heat beam provided by an infrared laser. Video angiograms are
generated with excitation illumination provided by an argon laser. Obtained
images are highly selective to the choriocapillaris and are sharply contrasted
against underlying and overlying structures. The images can be obtained
repetitively, during which period the circulating liposome concentration is
sufficient to generate adequate angiograms. These high-quality images have
revealed three distinct phases (filling, plateau, and draining) of the
choriocapillaris. In the plateau phase, a cluster of lobules fed by a common
arteriole has been uniformly illuminated. This defined cluster area does not
change in size while an infrared laser is continuously applied to the same spot,
which demonstrates that each cluster is functionally independent and no
physiological communication exists between them. Only in posterior regions do the
angiograms demonstrate during the filling and draining phases that each lobule is
filled from a central spot and drained along a peripheral ring, showing honeycomb
flow patterns. The regional differences in choriocapillaris flow patterns
revealed by LTA suggests that the choriocapillaris provides a more highly
efficient system of outflow in posterior regions than in peripheral regions. LTA
is useful in analyzing choroidal circulation in vivo and has the potential for
clinical application in the future. Additionally, LTA has a unique capability to
image choroidal neovascularization in animal models and it promises potential
application in age-related macular degeneration (AMD).
[Vaniqa and laser depilation in practice] [Article in French] Dahan S. Ann Dermatol Venereol. 2005 Jun-Jul;132(6-7 Pt 2):3S15-3S16.
[Excess facial hair and quality of life] [Article in French] Beylot C. Ann Dermatol Venereol. 2005 Jun-Jul;132(6-7 Pt 2):3S3-3S5.
Optimized prolate ablations with the NIDEK CXII excimer laser. Holladay JT, Bains HS. J Refract Surg. 2005 Sep-Oct;21(5 Suppl):S595-7.
PURPOSE: To describe a novel excimer laser ablation algorithm, termed optimized
prolate ablation (OPA), that uses both topography and ocular aberrometry and
maintains or improves the natural corneal shape postoperatively. METHODS: A
descriptive article outlining the theory behind this OPA algorithm. RESULTS: The
theoretical changes to the ablation algorithm described in this article will
produce a prolate cornea postoperatively. CONCLUSIONS: OPA treated eyes will have
equal or better visual quality than preoperatively because age-related changes
from lenticular spherical aberration are measured and treated.
The pitfalls of treating all actinic keratoses as squamous cell carcinomas. Wheeland RG. Semin Cutan Med Surg. 2005 Sep;24(3):152-4.
The greatest difficulties in managing a patient with numerous actinic keratoses
is deciding the order in which to treat the specific lesions and what modality to
use. The patient with a small number of lesions is probably most conveniently and
cost effectively treated using destructive techniques like cryosurgery,
electrodesiccation or photodynamic therapy with lasers. However, patients with
large numbers of lesions are probably best managed using a topical chemotherapy
agent, like 5-florouracil or imiquimod. If the patient’s health insurance company
limits coverage for the treatment of a specific number AK’s per visit, it may be
most prudent and logical to begin treatment of the largest or most rapidly
growing AK’s first and continue treatment of remaining lesions at subsequent
visits until all lesions have been eradicated.
[Light, laser and PDT therapy for acne] [Article in German] Borelli C, Merk K, Plewig G, Degitz K. Hautarzt. 2005 Nov;56(11):1027-32.
In recent years, a number of studies have evaluated the treatment of acne using
electromagnetic waves, such as lasers, photodynamic therapy, visible light or
radio waves. While the efficacy of laser treatment is still uncertain,
photodynamic therapy shows promising results, but with marked side-effects, as
destruction of sebaceous glands. Treatment with blue light (405-420 nm
wavelength) also appears effective and can be regarded as an treatment option for
Fabrication of DNA microarrays onto polymer substrates using UV modification protocols with integration into microfluidic platforms for the sensing of low-abundant DNA point mutations. Soper SA, Hashimoto M, Situma C, Murphy MC, McCarley RL, Cheng YW, Barany F. Methods. 2005 Sep;37(1):103-13. Epub 2005 Sep 29.
We describe the microfabrication and operational characteristics of a simple
flow-through biochip sensor capable of detecting low abundant point mutations in
K-ras oncogenes from genomic DNA, which carry high diagnostic value for
colorectal cancers. The biochip consisted of an allele-specific ligase detection
reaction (LDR) coupled to a universal array for interrogating multiple mutations
simultaneously from a clinical sample. The integrated sensing platform was
micro-manufactured from two different polymers, polycarbonate, PC, which was used
for the LDRs, and poly(methyl methacrylate), PMMA, which was used to build the
microarray. Passive elements were hot embossed into the PC and PMMA microchips
and then, the chips assembled into a three-dimensional architecture with the
interconnect fabricated from an elastomer, poly(dimethylsiloxane), PDMS, to
produce a leak-free connection between the biochips. The array in PMMA was
produced using a photomodification process, which involved three steps; (1) UV
(254 nm) exposure of the polymer surface; (2) EDC coupling of amine-terminated
oligonucleotide probes to the surface (via an amide bond) and; (3) washing of the
surface. The LDR/hybridization flow-through biochip performed the entire assay at
a relatively fast processing speed: 6.5 min for on-chip LDR, 10 min for washing,
and 2.6 min for fluorescence scanning (total processing time=19.1 min) and could
screen multiple mutations simultaneously for high throughput applications at a
level of one mutant sequence in 100 wild-type sequences.
[Confocal microscopy of the cornea in photorefractive surgery] [Article in Spanish] Javaloy J, Vidal MT, Ruiz-Moreno JM, Alió JL. Arch Soc Esp Oftalmol. 2005 Sep;80(9):497-509.
OBJECTIVE: Corneal refractive surgery involves a range of techniques which have
assumed a growing importance during the last few years. The advances of very
different surgical methods and the early age of the majority of the patients
subjected to surgery, limits our knowledge of the histopathologic changes in the
operated corneas. For this reason, the development of any diagnostic tool which
can permit us to improve our knowledge of the wound healing process would be of
significant value. As we describe in our paper, confocal microscopy enables the
assessment of the more important advantages for the study of corneal wound
healing after refractive surgery: high magnification, harmless, and “in vivo”,
providing pathogenic information and lateral and axial definition not achievable
with other exploration techniques. CONCLUSION: Confocal microscopy appears to be
an essential tool for creating a global concept of quality in corneal refractive
Nonablative laser surgery for pigmented skin. Goldberg DJ. Dermatol Surg. 2005 Oct;31(10):1263-7.
BACKGROUND: Nonablative laser surgery has been proven to improve early
photodamaged skin and acne scars. These techniques include treatments with
lasers, light sources, and/or radiofrequency devices. OBJECTIVES: To review the
history of nonablative technology and its applicability to darker skin types and
to provide an objective look at the various published studies documenting the
efficacy of nonablative technology. CONCLUSION: Nonablative laser surgery can
improve skin quality and acne scars in all skin types. Complications are rare but
can occur. Future studies are required to compare the efficacy of the various
Laser microdissection in CNS research. Böhm C, Newrzella D, Sorgenfrei O. Drug Discov Today. 2005 Sep 1;10(17):1167-74.
The complexity of the brain makes the investigation of anatomically defined
regions using manual dissection techniques problematic. With these manual
dissection techniques, only a mixture of many different cell types can be
obtained. This leads to averaging the contents of all the different cell types,
making it nearly impossible to observe effects that are specific to one type of
cell. Laser microdissection enables individual cell-types to be dissected
accurately from the brain for subsequent analysis of the genome, proteome or,
most frequently, the transcriptome. Investigating only functionally relevant
cells with high specificity provides unambiguous data, resulting in faster
identification of potential targets, the elucidation of drug mode-of-action, as
well as aiding identification of biomarkers for diagnostics use.
Intense pulsed light and laser treatment of facial telangiectasias and dyspigmentation: some theoretical and practical comparisons. Ross EV, Smirnov M, Pankratov M, Altshuler G. Dermatol Surg. 2005 Sep;31(9 Pt 2):1188-98.
BACKGROUND AND OBJECTIVE: A comparative overview is presented, both theoretical
and clinical, for intense pulsed light (IPL) and laser treatment of facial
telangiectasias and pigmented lesions. MATERIALS AND METHODS: A narrative
approach describes light penetration into the epidermis, dermis, dermal-epidermal
junction, and facial ectasias. Based on mathematical models, we examine some
temperature profiles for monochromatic and broadband light sources. Specifically,
temperature elevations of representative vascular targets are discussed. Also,
clinical scenarios are reviewed for both IPL and laser. Although multiple
monochromatic devices are reviewed, only the 532 and 595 nm wavelengths are
emphasized. RESULTS: In theory, an IPL can be filtered to simulate 532 and 595 nm
laser light in the treatment of telangiectasias and dyschromias. In comparing our
experiences with the different devices, all three (IPL, 532 nm laser, and 595 nm
laser) are capable of achieving a reduction in ectasias and hyperpigmented
macules. CONCLUSIONS: With an optimal set of parameters, IPLs and lasers are
comparable in the treatment of vascular and pigmented lesions with respect to
treatment efficiency and safety.
Review of photorejuvenation: devices, cosmeceuticals, or both? Rokhsar CK, Lee S, Fitzpatrick RE. Dermatol Surg. 2005 Sep;31(9 Pt 2):1166-78; discussion 1178.
BACKGROUND: Both the public and the medical profession have placed a lot of
attention on reversal of signs of aging and photodamage, resulting in numerous
cosmeceutical products and nonablative laser techniques designed to achieve these
results. OBJECTIVE: The purpose of this report is to briefly review both the
cosmeceutical products and nonablative laser techniques that appear to be most
promising based on published studies. After this review, recommendations for
potential enhancement of benefits by combining cosmeceuticals and laser
treatments will be explored. RESULTS: Pulsed dye lasers targeting microvessels,
intense pulsed light targeting both melanin and microvessels, and midinfrared
lasers targeting dermal water and collagen all appear to have some ability to
improve skin texture, color, and wrinkling. Retinoids, vitamin C, alpha-hydroxy
acids, and topical growth factors may also stimulate repair mechanisms that
result in similar improvements in photodamaged skin. CONCLUSION: Although
supported only by theoretic considerations and anecdotal reports, it seems
logical that the concurrent use of appropriate cosmeceuticals with nonablative
laser photorejuvenation should result in enhanced benefits.
Effective and safe use of lasers, light sources, and radiofrequency devices in the clinical management of Asian patients with selected dermatoses. Chan HH. Lasers Surg Med. 2005 Sep;37(3):179-85.
BACKGROUND AND OBJECTIVES: The use of lasers, light sources, and radiofrequency
devices in Asian patients differs from their use in Caucasians in several
respects. STUDY DESIGN/MATERIALS AND METHODS: The disease spectrum is very
different with pigmentary disorders being more commonly encountered in Asian
populations. Asian skin, with its higher epidermal melanin content, is more
likely to develop adverse reactions, especially post-inflammatory
hyperpigmentation (PIH), following treatment. RESULTS AND CONCLUSIONS: The
purpose of this article is to discuss the effective and safe use of lasers, light
sources, and radiofrequency devices in the clinical management of Asian patients
with selected dermatoses. Copyright 2005 Wiley-Liss, Inc.
Management of nasal hemangiomas. Hochman M, Mascareno A. Arch Facial Plast Surg. 2005 Sep-Oct;7(5):295-300.
Infantile hemangiomas commonly involve the nose. Because of the nose’s prominence
as an aesthetically and functionally sensitive area, management of these lesions
has important implications. The available options including medical therapy,
lasers, and surgery are reviewed with recommendations specific to nasal tip and
lobule lesions based on the senior author’s (M.H.) experience.
Description and analysis of treatments for port-wine stain birthmarks. Kelly KM, Choi B, McFarlane S, Motosue A, Jung B, Khan MH, Ramirez-San-Juan JC, Nelson JS. Arch Facial Plast Surg. 2005 Sep-Oct;7(5):287-94.
Port-wine stain (PWS) birthmarks are congenital, low-flow vascular malformations
of the skin. Lasers are the modality of choice for the treatment of PWS
birthmarks, and for most patients the pulsed-dye laser in conjunction with
epidermal cooling offers the greatest efficacy and safety. Other light devices,
including the 532-nm frequency-doubled Nd:YAG laser, intense pulsed light,
1064-nm Nd:YAG laser, and combined 1064/532-nm system, may be useful during a
treatment course for resistant PWS. Laser treatment results in blanching of most
lesions, although complete resolution may not occur and some resistant PWS
birthmarks respond minimally, if at all. Factors limiting laser treatment include
variable vascular geometry, inadequate damage of some vessels, and lesional
posttreatment recurrence as a result of neovascularization. Alternative or
adjunct treatment options that address these limitations should be explored,
including noninvasive real-time imaging to optimize the selection of treatment
settings, photodynamic therapy, and perioperative use of antiangiogenic
cDNA microarray analysis after laser microdissection in proliferating islets of partially pancreatectomized mice. Katsuta H, Koyanagi-Katsuta R, Shiiba M, Anzai K, Irie T, Aida T, Akehi Y, Nakano M, Yasunami Y, Harada M, Nagafuchi S, Ono J, Tachikawa T. Med Mol Morphol. 2005 Mar;38(1):30-5.
With islet transplantation having grown in popularity since the introduction of
the Edmonton protocol, how to secure an unlimited source of islets has become an
urgent problem. To resolve this problem, techniques to induce or proliferate
islets are urgently required. To achieve this goal, gene expression analysis
using a cDNA microarray in islets of partially pancreatectomized mice, in which
the remaining islets regenerate and proliferate with insulin secretion and
glucose responsiveness, provides us with valuable information. However, those
experiments have two critical problems: first, how to selectively collect the
regenerating or proliferating islets, and second, the shortage of total RNA
extracted from one islet for a microarray analysis. A useful system was thus
designed which combined laser microdissection, cDNA amplification by SMART PCR,
which can maintain the relative expression profile of transcripts throughout
reactions, and a cDNA microarray. Furthermore, this system is expected to
contribute to future studies regarding not only islet regeneration but also the
function of the islet itself, and this system may also be applicable to many
other types of endocrine tissue. In this review, the details of this system are
presented and discussed.
Quantitative light fluorescence: a technology for early monitoring of the caries process. Stookey GK. Dent Clin North Am. 2005 Oct;49(4):753-70, vi.
Quantitative light fluorescence (QLF) can detect about twice as many
demineralized precavitated enamel areas a conventional visual examination or any
other caries detection instrument. This technology has been used in several
controlled clinical trials with the consistent observation that it is capable of
monitoring and quantifying changes in the mineral content and size of clinically
visible noncavitated white spot lesions; therefore, it can be used to assess the
impact of preventive measures on the remineralization and reversal of the caries
process. The anticipated future use of QLF with dehydration to identify active
areas of demineralization will markedly enhance the utility of this technology in
clinical dental research and dental practice.
Utility of radiology, laser fluorescence, and transillumination. Yang J, Dutra V. Dent Clin North Am. 2005 Oct;49(4):739-52, vi.
This article provides readers with an overview of the latest developments in
caries detection using radiology, laser fluorescence, and transillumination.
Different imaging techniques, methods to assess diagnostic accuracy, and factors
affecting the diagnostic accuracy of imaging in film and digital receptors are
discussed. In addition, the DIAGNOdent and DIFOTI devices are introduced as
possible supplemental techniques for detecting incipient and hidden carious
Base units of the SI, fundamental constants and modern quantum physics. Bordé CJ. Philos Transact A Math Phys Eng Sci. 2005 Sep 15;363(1834):2177-201.
Over the past 40 years, a number of discoveries in quantum physics have
completely transformed our vision of fundamental metrology. This revolution
starts with the frequency stabilization of lasers using saturation spectroscopy
and the redefinition of the metre by fixing the velocity of light c. Today, the
trend is to redefine all SI base units from fundamental constants and we discuss
strategies to achieve this goal. We first consider a kinematical frame, in which
fundamental constants with a dimension, such as the speed of light c, the Planck
constant h, the Boltzmann constant k(B) or the electron mass m(e) can be used to
connect and redefine base units. The various interaction forces of nature are
then introduced in a dynamical frame, where they are completely characterized by
dimensionless coupling constants such as the fine structure constant alpha or its
gravitational analogue alpha(G). This point is discussed by rewriting the Maxwell
and Dirac equations with new force fields and these coupling constants. We
describe and stress the importance of various quantum effects leading to the
advent of this new quantum metrology. In the second part of the paper, we present
the status of the seven base units and the prospects of their possible
redefinitions from fundamental constants in an experimental perspective. The two
parts can be read independently and they point to these same conclusions
concerning the redefinitions of base units. The concept of rest mass is directly
related to the Compton frequency of a body, which is precisely what is measured
by the watt balance. The conversion factor between mass and frequency is the
Planck constant, which could therefore be fixed in a realistic and consistent new
definition of the kilogram based on its Compton frequency. We discuss also how
the Boltzmann constant could be better determined and fixed to replace the
present definition of the kelvin.
Precision spectroscopy of hydrogen and femtosecond laser frequency combs. Hänsch TW, Alnis J, Fendel P, Fischer M, Gohle C, Herrmann M, Holzwarth R, Kolachevsky N, Udem T, Zimmermann M. Philos Transact A Math Phys Eng Sci. 2005 Sep 15;363(1834):2155-63.
Precision spectroscopy of the simple hydrogen atom has inspired dramatic advances
in optical frequency metrology: femtosecond laser optical frequency comb
synthesizers have revolutionized the precise measurement of optical frequencies,
and they provide a reliable clock mechanism for optical atomic clocks. Precision
spectroscopy of the hydrogen 1S-2S two-photon resonance has reached an accuracy
of 1.4 parts in 10(14), and considerable future improvements are envisioned. Such
laboratory experiments are setting new limits for possible slow variations of the
fine structure constant alpha and the magnetic moment of the caesium nucleus
mu(Cs) in units of the Bohr magneton mu(B).
Photo-infrared pulsed bio-modulation (PIPBM): a novel mechanism for the enhancement of physiologically reparative responses. Santana-Blank LA, Rodríguez-Santana E, Santana-Rodríguez KE. Photomed Laser Surg. 2005 Aug;23(4):416-24.
OBJECTIVE: The present manuscript describes the non-invasive, long-range, energy
transport of a singular infrared pulsed laser device (IPLD) and the upstream
components of the original action mechanism, designated photo-infrared pulsed
bio-modulation (PIPBM). BACKGROUND DATA: Major strides have been taken in recent
years towards scientifically acceptable clinical applications of low-energy
lasers. Nevertheless, challenges still abound. For instance, the range of
potential target tissues for laser therapy in medicine has been, until now,
limited by the optical penetration of the beam or to sites accessible by
fiberoptics. In addition, much needs to be learned about the action mechanisms of
pulsed lasers, which can induce unique biological effects. METHODS: We present a
review of the IPLD laser technology and the PIPBM mechanism. RESULTS: The studies
reviewed suggest that the PIPBM enhances physiologically reparative processes in
a non-toxic and selective manner through the activation and modulation of chaotic
dynamics in water. These, in turn, lead not only to local, but also long-distance
(systemic) effects. CONCLUSIONS: Though additional studies are necessary to fully
explore the biological effects of the PIPBM induced by the IPLD, this mechanism
may have multiple potential applications in medicine that are the subject of
active current and future investigations.
Intradiscal therapy: a review of current treatment modalities. Singh K, Ledet E, Carl A. Spine. 2005 Sep 1;30(17 Suppl):S20-6.
STUDY DESIGN: A systematic review of the medical literature regarding current
intradiscal therapeutic methods. OBJECTIVES: To establish an understanding of the
current intradiscal treatment options for the management of low back pain.
SUMMARY OF BACKGROUND DATA: Current treatment of intradiscal disease is rapidly
evolving and as such should be a multidisciplinary effort that follows a logical,
orderly algorithm. Minimally invasive techniques, namely, intradiscal
electrothermal therapy (IDET), radiofrequency ablation (RFA), percutaneous
endoscopic laser discectomy (PELD), and cryoablation have challenged the
conventional surgical management of back pain. METHODS: Thirty-eight research
reports, published between 1986 and 2005, were systematically reviewed for
disease classification, surgical intervention, and treatment outcomes (neurologic
status, pain scores, and ambulation). RESULTS: The surgical literature on the
management of intradiscal disease continues to be limited to large series with
short clinical follow-ups. Arthrodesis continues to be the primary treatment
modality in the majority of patients. Newer treatment options including IDET,
RFA, PELD, and cryoablation have shown promising results with regards to
symptomatic relief and early return to function. CONCLUSION: Low back pain is an
extremely common and potentially debilitating problem. Adding biophysical methods
to well-tested biomechanical and newly investigated biomolecular solutions allows
for multiple avenues of therapeutic interventions. With future clinical and basic
science studies regarding intradiscal therapies forthcoming, we may soon alter
our current treatment algorithms for the management of discogenic back pain.
Laser treatment of vascular lesions. Schmults CD. Dermatol Clin. 2005 Oct;23(4):745-55.
Lasers and other light sources have been developed that remove or improve many
vascular lesions that were previously untreatable. Port-wine stains are the most
notable example. Vascular lasers and light sources represent a major advance in
dermatology for cosmetic and non-cosmetic applications. This article reviews the
common vascular conditions amenable to laser therapy and the approaches and
Clinical utility of pain–laser evoked potentials. Cruccu G, García-Larrea L. Suppl Clin Neurophysiol. 2004;57:101-10.
The role of secondary somatosensory cortex and insula in pain. Mauguière F. Suppl Clin Neurophysiol. 2004;57:62-71.
[Analysis of intracellular membrane protein function by small molecule-based chromophore-assisted laser inactivation] [Article in Japanese] Kikuchi K, Hirose K, Iino M, Nagano T.
Lasers and light therapy for acne vulgaris. Bhardwaj SS, Rohrer TE, Arndt K. Semin Cutan Med Surg. 2005 Jun;24(2):107-12.
Acne vulgaris remains an emotionally and debilitating dermatologic disease, and
is conventionally treated with a variety of oral and topical therapies with a
number of significant side effects. An evolving understanding of laser-tissue
interactions involving Propionibacterium acnes-produced porphyrins, and the
development of infrared nonablative lasers to target sebaceous glands, has lead
to the development of an escalating number of laser, light and radiofrequency
devices for acne. Used as monotherapy or in combination, these devices are
showing promise as a method to clear acne in a convenient, non-invasive manner,
though there remains a clear need for long-term data and randomized, blinded
Retinal damage by optical radiation. An alternative to current, ACGIH-inspired guidelines. Vos JJ, van Norren D. Clin Exp Optom. 2005 Jul;88(4):200-11.
BACKGROUND: The ACGIH guidelines for protection against retinal damage by optical
radiation are often difficult to apply due to their lack of transparency. The
less known guidelines by the Netherlands Health Council (HCN), dating from 1978
and updated in 1993, might offer a way out in many cases. METHODS: A comparison
is made of these guidelines, embedded in a short sketch of the history. They are
illustrated by examples of applications. RESULTS: In most cases the HCN
guidelines produce results that hardly deviate from those obtained with the ACGIH
guidelines but in some cases the results diverge and in other cases HCN gives an
answer where ACGIH seems to fall short. CONCLUSIONS: The HCN guidelines form a
good alternative to those of ACGIH.
[LASER applications in endodontics] [Article in French] De Moor R, Roeykens H, Meire M, Depraet F. Rev Belge Med Dent. 2005;60(2):115-45.
Since the development of the ruby laser by Maiman in 1960 and the application of
the laser for endodontics by Weichman in 1971, a variety of lasers with a wide
range of characteristics are now being used in endodontic therapy. In the past
two decades much experience and knowledge has been gained The first purpose of
the present paper is to provide an understanding of the essential physical
science behind laser technology and information on the effects of laser beams on
tissue (tissue interaction). A second purpose is to summarize laser applications
in endodontics, including their use in pulp diagnosis, dentinal hypersensitivity,
pulp capping and pulpotomy, modification of the root canal walls, sterilization
of the root canal system, cleaning–shaping–obturation of the root canal, and
endodontic surgery. It will be clear that a number of endodontic procedures with
conventional treatments cannot provide comparable results or are less effective.
Pulsed dye laser treatment, a review of indications and outcome based on published trials. Smit JM, Bauland CG, Wijnberg DS, Spauwen PH. Br J Plast Surg. 2005 Oct;58(7):981-7.
INTRODUCTION: Pulsed dye laser (PDL) treatment is based on the principle of
selective photothermolysis and is widely considered to be the treatment of choice
for a variety of cutaneous vascular lesions. OBJECTIVE: To review the indications
and outcome of PDL treatment and summarise new developments. METHOD: A
literature-based study has been conducted entailing the review of publications
over the period January 1993-December 2003 using the databases Medline and
Cochrane CENTRAL. RESULTS: The PDL was found to be effective in port wine stain,
facial telangiectasia, leg telangiectasia <0.5 mm, scars, hypertrophic scars and
ulcerated haemangioma. DISCUSSION: Essential characteristics of lesions suitable
for PDL treatment are discussed and guidelines are presented for future research.
Rejuvenation of the aging hand. Butterwick KJ. Dermatol Clin. 2005 Jul;23(3):515-27, vii.
This article reviews aging of the hand and the treatment options for cosmetic
rejuvenation. Options available for cutaneous rejuvenation include
microdermabrasion, chemical peeling, intense light sources, and laser therapy,
including pigment lasers, ablative resurfacing, and noninvasive rejuvenation.
Protuberant veins of the aging hand can be treated effectively with
sclerotherapy. The soft tissue atrophy of the aging hand is best treated with fat
augmentation. The article concludes with a mention of new fillers that are just
beginning to be used for soft tissue atrophy of the hand.
Nanotechnology-based drug delivery for cancer. Jain KK. Technol Cancer Res Treat. 2005 Aug;4(4):407-16.
Nanobiotechnologies have been applied to improve drug delivery and to overcome
some of the problems of drug delivery in cancer. These can be classified into
many categories that include use of various nanoparticles, nanoencapsulation,
targeted delivery to tumors of various organs, and combination with other methods
of treatment of cancer such as radiotherapy. Nanoparticles are also used for gene
therapy for cancer. Some of the technologies enable combination of diagnostics
with therapeutics which will be important for the personalized management of
cancer. Some of the limitations of these technologies and prospects for future
development are discussed.
Laser capture microdissection of hepatic stages of the human parasite Plasmodium falciparum for molecular analysis. Semblat JP, Silvie O, Franetich JF, Mazier D. Methods Mol Biol. 2005;293:301-7.
Despite the sequencing of parasite genomes and development of DNA microarray
technology, gene profiling of parasites remains a difficult task. For example,
transcriptome analysis cannot currently be applied to the hepatic stages of the
malaria parasite Plasmodium falciparum due to difficulties in obtaining
sufficient amounts of parasite material that lies among the large excess of host
cell RNA. Here, we describe the isolation of P. falciparum-infected human
hepatocytes by a laser capture microdissection approach. Reverse transcriptase
polymerase chain reaction amplification of several P. falciparum transcripts
demonstrates the high quality of the RNA recovered after microdissection. This
approach should enable analysis of P. falciparum transcriptome during its hepatic
development, a major step toward the identification of new therapeutic and
Laser capture microdissection and PCR for analysis of human papilloma virus infection. Chew K, Rooney PH, Cruickshank ME, Murray GI. Methods Mol Biol. 2005;293:295-300.
Human papilloma virus (HPV) infection is considered one of the main factors
involved in the pathogenesis of endocervical adenocarcinoma. However, the
cellular location of HPV in this type of tumor is controversial. We have
developed a method to determine the presence of HPV type 16 in endocervical
cancer cells using laser capture microdissection followed by DNA extraction and
qualitative polymerase chain reaction. Our results show that HPV type 16 is
present in endocervical adenocarcinoma cells.
Use of laser capture microdissection together with in situ hybridization and real-time PCR to study distribution of latent herpes simplex virus genomes in mouse trigeminal ganglia. Chen XP, Mata M, Fink DJ. Methods Mol Biol. 2005;293:285-93.
The herpes simplex virus (HSV) frequently establishes a latent state in neurons,
which can then be reactivated from the infected neurons. Quantifying the
single-cell viral load is essential for understanding latency and reactivation of
this virus. In this chapter the methods of laser capture microdissection and
quantitative real-time polymerase chain reaction with in situ hybridization have
been combined to determine the HSV copy number per neuron in latently infected
trigeminal ganglia. The distribution of latent herpes simplex genomes at the
individual cell level has been deteremined and the relationship of the number of
latent genomes to the expression of latency-associated transcripts established.
Genetic analysis of HIV by in situ PCR-directed laser capture microscopy of infected cells. Marras D. Methods Mol Biol. 2005;293:271-83.
Behind the exponential expansion of the acquired immunodeficiency syndrome (AIDS)
epidemic, there is a continuous and progressive molecular evolution of human
immunodeficiency virus (HIV)-1. In this regard, the molecular analysis of viral
strains infecting several anatomic compartments in humans has become critical to
understanding AIDS-related pathologies and to improving emerging therapeutic
protocols. Laser capture microdissection provides outstanding results in the
genetic analysis of HIV-1 variants detectable in AIDS patients. The ability of
the instrument to microdissect infected cells from a heterogeneous tissue
compartment allows the investigator to obtain critical information regarding the
genetic nature of a specific viral strain. To perform laser capture
microdissection with better accuracy, a priori detection techniques may provide
useful information about HIV distribution in the tissue specimen. An in situ
polymerase chain reaction (PCR) assay on a serial slide results in a detailed map
of the viral infection specific for the case under analysis. The knowledge of HIV
distribution in the tissue section is critical for improving the dissection of
infected cells by laser capture microscopy. This chapter describes laser capture
microdissection and in situ PCR and its role in the analysis of the genetic
nature of HIV-1 variants and quasispecies.
Proteomic analysis of human bladder tissue using SELDI approach following microdissection techniques. Krieg RC, Gaisa NT, Paweletz CP, Knuechel R. Methods Mol Biol. 2005;293:255-67.
Lysing of a complete biopsy sample results in a mixture of desired and undesired
proteins, reflecting the originating cell types. Therefore microdissecting tissue
material is mandatory prior to sample lysis and all downstream applications of
protein analysis (proteomics). The two most important dissecting methods for
bladder tissue specimens are manual microdissection and laser microdissection.
Sample transfer can further be separated into manual laser pressure catapulting
(LPC) and laser capture microdissection (LCM). One of the possible downstream
applications of protein analysis is surface-enhanced laser desorption ionization
(SELDI) time-of-flight mass spectrometry. The small quantities of tissue obtained
by microdissection are sufficient for use in the SELDI technique.
Laser capture microdissection and colorectal cancer proteomics. Lawrie LC, Curran S. Methods Mol Biol. 2005;293:245-53.
The ability to define protein profiles of normal and diseased cells is important
in understanding cell function. Laser capture microdissection permits the
isolation of specific cell types for subsequent molecular analysis. In this study
we have established conditions for obtaining proteomic information from laser
capture microdissected colorectal cancer cells. Laser capture microdissection was
performed on toluidine blue-stained frozen sections of colorectal cancer.
Proteins were solubilized from microdissected cells and the solubilized proteins
were separated by two-dimensional gel electrophoresis: protein spots were
characterized by peptide mass mapping using matrix assisted laser desorption
ionization-time of flight mass spectrometry. Proteins isolated from laser capture
microdissected tissue retained their expected electrophoretic mobility and
peptide mass mapping was also unaffected. The ability to study the protein
expression profile of specific cell types will allow for the identification of
novel disease markers and therapeutic targets and also provide for the enhanced
understanding of pathogenetic mechanisms.
Analysis of pituitary cells by laser capture microdissection. Lloyd RV, Qian X, Jin L, Ruebel K, Bayliss J, Zhang S, Kobayashi I. Methods Mol Biol. 2005;293:233-41.
The anterior pituitary gland consists of a heterogeneous population of various
cell types. To study a single cell type with a homogeneous cell population, one
can perform laser capture microdissection (LCM). Because different pituitary
cells have unique immunophenotypic profiles, it is possible to perform
immunohistochemical staining before LCM (immuno-LCM) for the collection of a
phenotypically homogeneous cell population. These techniques were developed and
applied to dissociated anterior pituitary cells and cultured pituitary cells.
When combined with reverse transcriptase polymerase chain reaction, it is
possible to analyze gene expression in as few as one to 10 pituitary cells. We
have used the immuno-LCM technique to prepare homogeneous populations of
folliculostellate cells. These cells were analyzed for expression of peptides and
receptors. Anterior pituitary hormones were not expressed by these cells. These
results show the utility of immuno-LCM for cellular and molecular studies of gene
Laser capture microdissection for analysis of macrophage gene expression from atherosclerotic lesions. Trogan E, Fisher EA. Methods Mol Biol. 2005;293:221-31.
Macrophage foam cells are critical mediators in atherosclerosis plaque
development. A better understanding of the in vivo transcript profile of foam
cells during the formation and progression of lesions may lead to novel
therapeutic interventions. Toward this goal, we demonstrate for the first time
that foam cell-specific RNA can be purified from atherosclerotic arteries, a
tissue of mixed cellular composition. Foam cells from apolipoprotein (apo) E-/-
mice were isolated by laser capture microdissection (LCM); RNA was extracted and
used for molecular analysis by real-time quantitative polymerase chain reaction.
Compared to whole tissue, a significant enrichment of foam cell-specific RNA
transcripts was achieved. Furthermore, to test the ability to quantify
differences in gene expression in response to an inflammatory stimulus, apoE-/-
mice were injected with lipopolysaccharide, after which the transcriptional
induction of the inflammatory mediators, VCAM, ICAM, and MCP-1, was observed in
lesional macrophage foam cell RNA. These approaches will facilitate the study of
macrophage gene expression under various conditions of plaque formation,
regression, and response to genetic and environmental perturbations.
Quantification of gene expression in mouse and human renal proximal tubules. Kaimori JY, Takenaka M, Okubo K. Methods Mol Biol. 2005;293:209-19.
The kidney consists of many functional modules called nephrons. Each nephron has
a tubular structure made up of several structurally and functionally distinct
segments. The analysis of individual segments requires the use of microdissection
techniques. We describe protocols that have been used to successfully isolate
messenger RNA from proximal tubules of both freshly prepared and archival samples
using laser capture microdissection and laser-manipulated microdissection.
Gene expression profiling of primary tumor cell populations using laser capture microdissection, RNA transcript amplification, and GeneChip microarrays. Luzzi VI, Holtschlag V, Watson MA. Methods Mol Biol. 2005;293:187-207.
Gene expression profiling from microdissected cell populations is a powerful
approach to explore molecular processes involved in development and solid tumor
biology. In this chapter, we detail robust and validated methods for tissue
preparation and isolation of high-quality RNA from microdissected cell
populations. A protocol is also provided for linear transcript amplification
using as little as 10 ng of total RNA to produce labeled cRNA targets for
hybridization to GeneChip high-density oligonucleotide microarrays. Particular
emphasis is placed on troubleshooting each technical step in the protocol and
measures of quality assurance for both RNA isolation and resulting microarray
Laser microdissection and RNA analysis. Fink L, Bohle RM. Methods Mol Biol. 2005;293:167-85.
Microdissection techniques have become an important tool to link histomorphology
and pathophysiological events using modern methods of molecular biology. They
allow isolation of cell clusters or even single cells precisely under optical
control from complex tissue structures for further analysis of DNA, RNA, and
proteins. In particular, the fragile RNA molecules can be preserved during
microdissection so that gene expression and regulation measurement become
feasible in a cell type-specific manner within complex tissues. This report
focuses on and outlines the procedures for RNA investigation, from tissue
fixation, sectioning, and staining to downstream applications (RT-PCR, mRNA
quantification, and mRNA preamplification). Standards for the preparation of RNA
from frozen and formalin-fixed tissues are presented. Specific protocols are
given for both the isolation of RNA from small numbers of cells (50 cells) as
well as for larger cell numbers. While most of the procedures are identical for
the microdissection systems, special features of each technique are mentioned.
Laser-assisted cell microdissection using the PALM system. Micke P, Ostman A, Lundeberg J, Ponten F. Methods Mol Biol. 2005;293:151-66.
Laser-assisted microdissection has enabled the collection of morphologically
defined cell populations from a tissue section. The PALM Robot MicroBeam laser
microdissection system provides a robust system for the retrieval of specified
cells (including single cells). Due to the fragile nature of DNA, and in
particular RNA, robust protocols are required to obtain reliable data from a
limited number of cells (1-10.000 cells). This chapter describes the application
of the PALM MicroBeam system to isolate RNA and DNA from cells in a complex
tissue for subsequent molecular analysis. Protocols for successful analysis of
RNA from 500 to 1000 cells, including steps to produce cDNA for subsequent
polymerase chain reaction analysis, are given. The cDNA could also be used as a
template for linear amplification in order to perform gene array analysis.
Furthermore, a protocol for genomic analysis of p53 mutations from single cells
is given. The described procedures emphasize preparation of tissue, laser
microdissection including catapulting of cells, and extraction of RNA and DNA.
Downstream experiments for validation are also shown.
Laser-assisted microdissection of membrane-mounted sections following immunohistochemistry and in situ hybridization. Gjerdrum LM, Hamilton-Dutoit S. Methods Mol Biol. 2005;293:139-49.
Laser microbeam microdissection (LMM) is an increasingly important histological
technique for obtaining homogeneous cell populations and tissue components in
order to analyze target-specific changes in genes, gene expression, and proteins.
The quality of data obtained with LMM is heavily dependent on the precision with
which the target for microdissection can be identified. Since no cover slip is
used during LMM, tissue morphology is poor compared with traditional light
microscopy. This hampers morphological recognition of targets for microdissection
in routinely stained sections and can be a limiting factor in the use of this
technique. Immunohistochemistry (IHC) and in situ hybridization (ISH) can improve
the identification of specific cell populations in situ in tissue sections, but
there are a number of problems in applying these methods to slides prepared for
LMM. In this chapter, we present optimized protocols that allow IHC to be
performed for detecting a wide range of antigens in conjunction with LMM, both on
formalin-fixed paraffin-embedded and on frozen sections. In addition, we present
a quick, versatile protocol for performing ISH on archival material suitable for