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The Low Level Laser Therapy -
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New reports will be added every months. If you have published a scientific report  recently or have it in the pipeline, why not make a personal abstract and mail it to us? SLMS (Swedish Laser-Medical Society) has 1500 lllt - laser therapy studies in its library, but we certainly don’t have everything.


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LaserWorld Science: 31 new abstracts, July 2005.

 
Selected laser therapy abstracts from Aug 2004.
Effects of Low-Intensity Polarized Visible Laser Radiation on Skin Burns: A Light Microscopy Study. Effects of Pulse Frequency of Low-Level Laser Therapy (LLLT) on Bone Nodule Formation in Rat Calvarial Cells
Laser therapy of duodenal ulcers: effect on indices of microcirculation, cell membrane permeability and homeostasis of trace elements Effects of Low-Level Laser Therapy (LLLT) of 810 nm upon in Vitro Growth of Bacteria: Relevance of Irradiance and Radiant Exposure
Photostimulation of coronary arteries with low power laser radiation: preliminary results for a new method in invasive cardiology therapy Effect of the Clinical Application of the GaAlAs Laser in the Treatment of Dentine Hypersensitivity
[Low power laser biostimulation in the treatment of bronchial asthma]. Effect of Low-Power Radiation (Helium/Neon) upon Submandibulary Glands
Effects of the 650 nm laser stimulation, utilizing clinical doses for proliferation of cultured human fibroblasts. Low-Level Laser Irradiation Attenuates Production of Reactive Oxygen Species by Human Neutrophils
Transmeatal cochlear laser (TCL) treatment of cochlear dysfunction: a feasibility study for chronic tinnitus Effect of NASA Light-Emitting Diode Irradiation on Molecular Changes for Wound Healing in Diabetic Mice

Effects of Low-level Laser Therapy in HIV/AIDS-positive Patients After Exodontic Procedures.

Influence of Linearly Polarized Near-Infrared Irradiation on Deformability of Human Stored Erythrocytes
Role of Gallium Arsenide Laser Irradiation at 890 nm as an Adjunctive to Anti-tuberculosis Drugs in the Treatment of Pulmonary Tuberculosis The Comparison of Effects between Pulsed and CW Lasers on Wound Healing

Usefulness of Low-Level Laser for Control of Painful Stomatitis in Patients with Hand-Foot-and-Mouth Disease.

NASA Light-Emitting Diodes for the Prevention of Oral Mucositis in Pediatric Bone Marrow Transplant Patients
Low-Intensity Near-Infrared Laser Radiation-Induced Changes of Acetylcholinesterase Activity of Human Erythrocytes. Effects of 630-, 660-, 810-, and 905-nm Laser Irradiation Delivering Radiant Exposure of 1-50 J/cm2 on Three Species of Bacteria in Vitro

Effect of 830-nm Laser Light on the Repair of Bone Defects Grafted with Inorganic Bovine Bone and Decalcified Cortical Osseous Membrane.

Contraindications in Noninvasive Laser Therapy: Truth and Fiction
Low Level Laser Therapy-a conservative approach to the burn scar? Low-Intensity Laser Therapy/Combined Phototherapy in the Management of Chronic Venous Ulceration: A Placebo-Controlled Study
Low-level laser therapy stimulates bone-implant interaction: an experimental study in rabbits. TI Therapeutic photobiomodulation for methanol-induced retinal toxicity.
Dose and Wavelength of Laser Light Have Influence on the Repair of Cutaneous Wounds. Polychromatic LED Therapy in Burn Healing of Non-diabetic and Diabetic Rats
Selected laser therapy abstracts from April 2004.
Effects of Low-level Laser Therapy in HIV/AIDS-positive Patients After Exodontic Procedures. Effectiveness of low-level laser therapy in temporomandibular disorder.
Effects of infrared and low-power laser irradiation on cell viability, glutathione and glutathionerelated enzyme activities in primary rat hepatocytes. Laser photostimulation accelerates wound healing in diabetic rats.
Laser light prevents apoptosis in Cho K-1 cell line. Comparison of the photostimulatory effects of visible HeNe and infrared GaAs lasers on healing impaired diabetic rat wounds.
Non-pharmacological approaches to chronic headaches: transcutaneous electrical nerve stimulation, laser therapy and acupuncture in transformed migraine treatment.  Efficacy of 300 mW, 830 nm laser in the treatment of chronic pain: a survey in a general practice setting.
Efficacy of low level laser therapy in myofascial pain syndrome: an algometric and thermographic evaluation. Photobiological modulation of cell attachment via cytochrome c Oxidase.
The clinical efficacy of low-power laser therapy on pain and function in cervical osteoarthritis. Effects of low-power laser exposure on masseter muscle pain and microcirculation.
cDNA microarray analysis of gene expression profiles in human fibroblast cells irradiated with red light. Effects of infrared and low-power laser irradiation on cell viability, glutathione and glutathionerelated enzyme activities in primary rat hepatocytes.
Non-pharmacological approaches to chronic headaches: transcutaneouselectrical nerve stimulation, lasertherapy and acupuncture in transformed migraine treatment Efecto de la estimulación láser de 650 nm, utilizando dosis de uso clínico, sobre la proliferación de fibroblastos humanos cultivados.
Transmeatal cochlear laser (TCL) treatment of cochlear dysfunction: a feasibility study for chronic tinnitus. [Low power laser biostimulation in the treatment of bronchial asthma]
Photostimulation of coronary arteries with low power laser radiation: preliminary results for a new method in invasive cardiology therapy. Usefulness of Low-Level Laser for Control of Painful Stomatitis in Patients with Hand-Foot-and-Mouth Disease.
Effect of 830-nm Laser Light on the Repair of Bone Defects Grafted with Inorganic Bovine Bone and Decalcified Cortical Osseous Membrane Low-Intensity Near-Infrared Laser Radiation-Induced Changes of Acetylcholinesterase Activity of Human Erythrocytes.
 

 

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Selected abstracts from August 2004


Effects of Low-Intensity Polarized Visible Laser Radiation on Skin Burns: A Light Microscopy Study. Journal of Clinical Laser Medicine and Surgery. 2004; 22 (1): 59-66.
Simoes-Ribeiro M, Teixeira Da Silva D, Nabuco De Araujo C E et al.

This study was carried out to investigate the influence of low-intensity polarized visible laser radiation on the acceleration of skin wound healing. Low-level laser therapy at adequate wavelength, intensity, and dose can accelerate tissue repair. However, there is still unclear information about light characteristics, such as coherence and polarization. Some studies indicate that linearly polarized light can survive through long propagation distance in biological tissue. Three burns about 6 mm in diameter were created on the back of rats with liquid N(2). Lesion "L(//)" was irradiated by He-Ne laser (X= 632.8 nm), D= 1.0 J/cm(2), with linear polarization parallel to the spinal column of the rat. Lesion "L(//)" was irradiated using the same laser and dose, but the light polarization was aligned perpendicularly to the relative orientation. Lesion "C" was not irradiated in order to be considered as control. The animals were sacrificed at day 3-17 after lesion creation. Samples were collected and prepared for histological analysis. Results: Histological analysis showed that the healing of irradiated wounds was faster than that of non-irradiated wounds. Moreover, it was observed that skin wound repair is dependent on polarization orientation with respect to a referential axis as the animal's spinal column. Consequently, "L(//)" was completely healed after 17 days, whereas "L((perpendicular))" showed a moderate degree of healing after the same period. These results indicate that the relative direction of the laser polarization plays an important role in the wound healing process when highly coherent He-Ne laser is used.

[Laser therapy of duodenal ulcers: effect on indices of microcirculation, cell membrane permeability and homeostasis of trace elements]. Lazernaia terapiia iazvennoibolezni: vliianie na pokazateli mikrotsirkuliatsii, pronitsaemosti kletochnykh membran i mikroelementnogo gomeostaza. Eksperimental'naeiia i klinicheskaeiia gastrocenterologieiia. 2003; (5): 45-50.
Amirov N B.

123 patients with duodenal ulcer were examined. Laser therapy (LT) was included in the complex therapy for 89 of the patients. 34 patients underwent only traditional drug therapy and formed a control group. LT was carried out by 2 ways: intracavitary - by ulcer defect irradiation with the light guide through the gastroscope biopsy canal and helium-neon laser (HNL), and non-invasive--through the front abdominal wall in the corresponding areas, which was made by infrared laser (IRL). The comparison of two groups established that by including LT in the complex therapy for DU patients, the dynamics of clinical and laboratorial data is essential better than during traditional drug treatment (TMT). It was established that the inclusion of LT in the duodenal ulcer treatment has a positive impact on the course of the disease. This impact was displayed as faster reverse development of clinical symptoms, positive laboratory and instrumental data dynamics, blood serum microelements content normalization, membrane permeability increase by indicators of Na-Li counter-transport in the erythrocytes membrane and microcirculation improvement, mainly in the intravascular section.

Photostimulation of coronary arteries with low power laser radiation: preliminary results for a new method in invasive cardiology therapy.
Medical Science Monitor. 2003; 9 (7): 335-339.
Derkacz A,Bialy D, Protasiewicz Marcin et al.

The main problem after percutaneous coronary intervention (PCI) is restenosis affecting the site where dilatation is performed. In order to minimize its occurrence, the method of intravascular laser photostimulation (LP) with low power irradiation has been developed. The new procedure is carried out during PCI. A special setup was prepared for intravascular photostimulation with 808 nm wavelength laser diode and special diffuser, delivering the laser light into the coronary artery. The construction of the device makes it possible to irradiate the coronary artery in the place of previously performed of dilatation, in a satisfactory and programmable manner and with uniform intensity. We describe our own, unique LP procedure. Two pilot LP procedures carried out in our clinic are described here. The patients were diagnosed before treatment and followed up three and six months after the LP procedure with non invasive tests. After six months, a control angiography was also performed. The procedures were well tolerated. In both cases the follow-up examinations showed no evidence of restenosis. The new, innovative technique of intravascular low power laser photostimulation is a relatively inexpensive and easy to use treatment method. No negative side effects were observed after two procedures. The results obtained are very promising. Because the group of treated patients is still too small, the results cannot yet be subjected to statistical analysis.

[Low power laser biostimulation in the treatment of bronchial asthma]. Biostimulacija laserom niske snage u lecenju bronhijalne astme.
Medicinski pregled. 2003; 56 (9-10): 413-418.
Milojevic M, Kuruc V.

The investigation was aimed at defining therapeutic effects of low power laser irradiation by stimulating acupuncture points or local treatment of asthma. A prospective analysis included 50 patients treated during 2000, 2001 and 2002. Together with conservative treatment of present disease, these patients were treated with laser stimulation of acupuncture points in duration of ten days. During treatment changes of functional respiratory parameters were recorded. Results were compared with those in the control group. The control group consisted of the same number of patients and differed from the examination group only by not using laser stimulation. Patients with bronchial asthma presented with significant improvement of all estimated lung function parameters just 30 minutes after laser stimulation. Improvements achieved on the third and the tenth day of treatment were significantly higher) in the examination group in comparison with the control group. Further investigation confirmed that improvement of measured lung function parameters was significantly higher in younger patients, in patients whose disease lasted shorter, as well as in women. Patients with asthma, who were treated every three months for a one year period, presented with significantly lower frequency and intensity of attacks. The mechanism of laser stimulation activity in treatment of bronchial asthma is explained in detail, correlating our results to those obtained by other authors. A ten-day course of low-power laser stimulation of acupuncture points in patients with bronchial asthma improves both the lung function and gas exchange parameters. Positive effects of laser treatment inpatients with bronchial asthma are achieved in a short time and they last long, for several weeks, even months. Successive laser stimulation in asthmatics prolongs periods of remission and decreases the severity of asthmatic attacks. Better positive effects of laser stimulation are achieved in younger asthmatics, in those with shorter disease history and in female patients. There is a negative correlation between effects of laser stimulation and patients' age and disease history. However, these characteristics do not affect response rate and speed but positive laser stimulation effects are achieved in a shorter period in female asthmatics.

Effects of the 650 nm laser stimulation, utilizing clinical doses for proliferation of cultured human fibroblasts. (Efecto de la estimulación láser de 650 nm, utilizando dosis de uso clínico, sobre la proliferación de fibroblastos humanos cultivados.)
Lomelí-Rivas A, Krötzsch E, Michtchenko A.

Low-level laser stimulation has been used successfully in the treatment of wound healing, and other diseases. Fibroblasts are cells involved in tissue repair, it is needed adequate laser doses for fibroblasts stimulation. The objective of this study is to know the effects of ? = 650 nm laser in proliferation of human cultivated fibroblasts, utilizing clinical doses. Human fibroblasts were synchronized in G0 stage, and irradiated with continuous wave of a 650 nm low-level laser at doses of 0.5, 1, 3, 5 and 7 J/cm2, with power density of 30 mW/cm2. Fibroblast proliferation was measured with a [3H]-tymidine incorporation method. The results were measured at 24, 48, 72 and 96 hours. Fibroblast proliferation showed no statistical differences between controls, but it was observed some structure changes. It is probably that clinical doses are not appropriated for culture stimulation, or maybe, it is needed another power density.

Transmeatal cochlear laser (TCL) treatment of cochlear dysfunction: a feasibility study for chronic tinnitus. Lasers in Medical Science. 2003, 18 (3): 154-161.
Tauber S, Schorn K, Beyer W, Baumgartner R.

Low-level-laser-therapy (LLLT) targeting the inner ear has been discussed as a therapeutic procedure for cochlear dysfunction such as chronic cochlear tinnitus or sensorineural hearing loss. Former studies demonstrate dose-dependent biological and physiological effects of LLLT such as enhanced recovery of peripheral nerve injuries, which could be of therapeutic interest in cochlear dysfunction. To date, in patients with chronic tinnitus mastoidal and transmeatal irradiation has been performed without systematic dosimetric assessment. However, light-dosimetric studies on human temporal bones demonstrated that controlled application of laserlight to the human cochlea depends on defined radiator position within the external auditory meatus. This feasibility study first presents a laser application system enabling dose-controlled transmeatal cochlear laser-irradiation (TCL), as well as preliminary clinical results in patients with chronic cochlear tinnitus. The novel laser TCL-system, consisting of four diode lasers (lambda=635 nm-830 nm) and a new specific head-set applicator, was developed on the basis of dosimetric data from a former light-dosimetric study. In a preliminary clinical study, the TCL-system was applied to 35 patients with chronic tinnitus and sensorineural hearing loss. The chronic symptoms persisted after standard therapeutic procedures for at least six months, while retrocochlear or middle-ear pathologies have been ruled out. The patients were randomised and received five single diode laser treatments (lambda=635 nm, 7.8 mW cw, n=17 and lambda=830 nm, 20 mW cw, n=18) with a space irradiation of 4 J/cm2 site of maximal cochlear injury. For evaluation of laser-induced effects complete otolaryngologic examinations with audiometry, tinnitus masking and matching, and a tinnitus-self-assessment were performed before, during and after the laser-irradiation. The first clinical use of the TCL-system has been well tolerated without side-effects and produced no observable damage to the external, middle or inner ear. Changes of tinnitus loudness and tinnitus matching have been described. After a follow-up period of six months tinnitus loudness was attenuated in 13 of 35 irradiated patients, while two of 35 patients reported their tinnitus as totally absent.

Effects of Low-level Laser Therapy in HIV/AIDS-positive Patients After Exodontic Procedures.
Journal of Oral Laser Applications. 2003; 3 (2): 109-115.
Giovanni E M, Ferreira M C D, Souza R S et al.

The purpose of this study was to verify the efficiency of the GaAlAs laser in the stimulation of tissue repair and analgesic effect after tooth extractions in HIV/AIDS-positive patients. A low-level (790 nm, 30 mw) laser was applied in 15 HIV/AIDS-positive patients who required extractions totalling 36 teeth. Platelet count, T-CD4 lymphocytes, and the viral load of each patient were examined. After extraction and suturing, the low-potency laser beam was applied to the surgical area parallel to the long axis of the alveolus for a period of 2 min. All the patients were instructed not to use any medications or supplementary treatments. The postoperative exam was performed 8 days after surgery, including the suture removal, periapical radiograph, area wound healing evaluation, and a questionnaire to evaluate postoperative pain. The patients generally reported a comfortable postoperative period. If pain was present, it was very slight and required no medication or other therapy. The process of tissue regeneration and surgical wound healing took less time than with conventional procedures. Although the patients presented various degrees of immune suppression as measured by the T-CD4 lymphocyte count, and some had a high viral load, all responded satisfactorily in the postoperative period.

Role of Gallium Arsenide Laser Irradiation at 890 nm as an Adjunctive to Anti-tuberculosis Drugs in the Treatment of Pulmonary Tuberculosis
Indian J Chest Dis Allied Sci. 2003; 45: 13 – 19.
M.M. Puri and V.K. Arora

The present study was carried out to explore whether any benefit could be achieved by the addition of low level energy laser therapy (LLLT) to the conventional anti-tubercular chemotherapy. One-hundred-thirty new sputum smear positive patients of pulmonary tuberculosis were enrolled to evaluate the bio-stimulatory effects of Gallium Arsenide laser irradiation at 890 nm, as an adjuvant therapy. These patients were randomly divided into two groups to receive either LLLT or sham irradiation (control) concomitantly with anti-tuberculosis chemotherapy. The patients treated with semiconductor laser as an adjuvant therapy along with anti-tuberculosis drugs had a faster clearance of tubercle bacilli from the sputum as compared to the control group (P value at : 45 days=0.1392, 60 days=0.0117, 75 days=0.00805, 90 days=0.00739). These findings provide preliminary evidence that low level laser therapy with Gallium Arsenide laser may be a promising adjunctive therapy for patients with tuberculosis. Faster conversion of sputum should prevent the development of resistant mutants.

Usefulness of Low-Level Laser for Control of Painful Stomatitis in Patients with Hand-Foot-and-Mouth Disease.

Journal of Clinical Laser Medicine & Surgery. 21 (6): 363–367.
Toida M; Watanabe F; Kazumi Goto K; Shibata T.

The aim of this study was to evaluate the usefulness of low-level laser therapy (LLLT) for the control of painful stomatitis in patients with hand-foot-and-mouth disease (HFMD). Through a randomized double-blind placebo controlled trial, the painful period of HFMD stomatitis was compared between the LLLT group (n = 11) and the placebo LLLT one (n = 9), which had similar clinical backgrounds. The LLLT parameters supplied were as follows: wavelength of 830 nm, power of 30 mW, frequency of 30 Hz, and energy output of 1.1 J/cm2. Acceptability and safety of the treatment were also evaluated. The painful period was shorter in the LLLT group (4.0 ± 1.3 days) than in the placebo LLLT one (6.7 ± 1.6 days) with a statistically significant difference (p < 0.005). The treatment was judged acceptable for 90.0% (18 of 20) of patients. No adverse events were observed in any cases:


Low-Intensity Near-Infrared Laser Radiation-Induced Changes of Acetylcholinesterase Activity of Human Erythrocytes.
Journal of Clinical Laser Medicine & Surgery. 21 (6):351–355.
Kujawa J; Zavodnik L; Zavodnik I.

Suspensions of human erythrocytes in PBS (10% hematocrit) were irradiated with near-infrared (810 nm) therapy laser at different light doses (0-20 J) and light power (fluence rate; 200 or 400 mW) at 37°C. As the parameters characterizing the cell structural and functional changes membrane acetylcholinesterase (AchEase) activity, the membrane potential, the level of intracellular glutathione, the level of products of membrane lipid peroxidation, and the cell osmotic stability were measured. It was found that near-infrared low-intensity laser radiation produced complex biphasic dose-dependent changes of the parameters of AchEase reaction in the dose-dependent manner: at smaller doses of radiation (6 J) the maximal reaction rate and Michaelis-Menten constant value decreased, and at higher radiation doses these parameters increased. No significant changes of erythrocyte stability, cellular redox state (reduced glutathione or lipid peroxidation product levels), or cell membrane electrochemical potential were observed. Low-intensity near-infrared laser radiation (810 mn) produced AchEase activity changes, reflecting the effect of light on the enzyme due to energy absorption. Protein molecule conformational transitions and enzyme activity modifications in cells have been suggested as laser radiation-induced events.

Effect of 830-nm Laser Light on the Repair of Bone Defects Grafted with Inorganic Bovine Bone and Decalcified Cortical Osseous Membrane.
Journal of Clinical Laser Medicine & Surgery. 21 (6): 383–388.
Pinheiro A; De Assis Limeira Júnior F, Márquez Gerbi M E.

The aim of this study was to assess histologically the effect of LLLT (?830 nm) on the repair of standardized bone defects on the femur of Wistar albinus rats grafted with inorganic bovine bone and associated or not to decalcified bovine cortical bone membrane. Bone loss may be a result of several pathologies, trauma or a consequence of surgical procedures. This led to extensive studies on the process of bone repair and development of techniques for the correction of bone defects, including the use of several types of grafts, membranes and the association of both techniques. There is evidence in the literature of the positive effect of LLLT on the healing of soft tissue wounds. However, its effect on bone is not completely understood. Five randomized groups were studied: Group I (Control); Group IIA (Gen-ox®); Group IIB (Gen-ox® + LLLT); Group IIIA (Gen-ox® + Gen-derm®) and Group IIIB (Gen-ox® + Gen-derm® + LLLT). Bone defects were created at the femur of the animals and were treated according to the group. The animals of the irradiated groups were irradiated every 48 h during 15 days; the first irradiation was performed immediately after the surgical procedure. The animals were irradiated transcutaneously in four points around the defect. At each point a dose of 4 J/cm2 was given ( ~ 0.6 mm, 40 mW) and the total dose per session was 16 J/cm2. The animals were humanely killed 15, 21, and 30 days after surgery. The specimens were routinely processed to wax, serially cut, and stained with H&E and Picrosirius stains and analyzed under light microscopy. The results showed evidence of a more advanced repair on the irradiated groups when compared to non-irradiated ones. The repair of irradiated groups was characterized by both increased bone formation and amount of collagen fibers around the graft within the cavity since the 15th day after surgery, through analysis of the osteoconductive capacity of the Gen-ox® and the increment of the cortical repair in specimens with Gen-derm® membrane. It is concluded that LLLT had a positive effect on the repair of bone defect submitted the implantation of graft.

Low Level Laser Therapy-a conservative approach to the burn scar?
Burns. 2004 30(4):362-367.
Gaida K, Koller R, Isler C, Aytekin O et al.

Burn scars are known to be difficult to treat because of their tendency to worsen with hypertrophy and contracture. Various experimental and clinical efforts have been made to alleviate their effects but the problem has not been solved. Since patients keep asking for Low Level Laser Therapy (LLLT) and believe in its effectiveness on burn scars, and since former studies show contradictory results of the influence of LLLT on wound healing, this prospective study was designed to objectify the effects of LLLT on burn scars. Nineteen patients with 19 burn scars were treated with a 400mW 670nm Softlaser twice a week over 8 weeks. In each patient a control area was defined, that was not irradiated. Parameters assessed were the Vancouver Scar Scale (VSS) for macroscopic evaluation and the Visual Analogue Scale (VAS) for pruritus and pain. Photographical and clinical assessments were recorded in all the patients. Seventeen out of 19 scars exhibited an improvement after treatment. The average rating on the VSS decreased from [Formula: see text] to [Formula: see text] points in the treated areas, whereas the VSS in the control areas decreased from [Formula: see text] to [Formula: see text]. A correlation between scar duration and improvement through LLLT could be found. No negative effects of LLLT were reported. The present study shows that the 400mW 670nm softlaser has a positive, yet sometimes limited effect on burn scars concerning macroscopic appearance, pruritus, and pain.


Low-level laser therapy stimulates bone-implant interaction: an experimental study in rabbits.
Clin Oral Implants Res. 2004; 15 (3): 325-332.
Khadra M, Ronold H J, Lyngstadaas S P, Ellingsen J E, Haanaes H R.

This study was performed as an animal trial of 8 weeks duration with a blinded, placebo-controlled design. Two coin-shaped titanium implants with a diameter of 6.25 mm and a height of 1.95 mm were implanted into cortical bone in each proximal tibia of twelve New Zealand white female rabbits (n=48). The animals were randomly divided into irradiated and control groups. The LLLT was used immediately after surgery and carried out daily for 10 consecutive days. The animals were killed after 8 weeks of healing. The mechanical strength of the attachment between the bone and 44 titanium implants was evaluated using a tensile pullout test. Histomorphometrical analysis of the four implants left in place from four rabbits was then performed. Energy-dispersive X-ray microanalysis was applied for analyses of calcium and phosphorus on the implant test surface after the tensile test. The mean tensile forces, measured in Newton, of the irradiated implants and controls were 14.35 (SD+/-4.98) and 10.27 (SD+/-4.38), respectively, suggesting a gain in functional attachment at 8 weeks following LLLT (P=0.013). The histomorphometrical evaluation suggested that the irradiated group had more bone-to-implant contact than the controls. The weight percentages of calcium and phosphorus were significantly higher in the irradiated group when compared to the controls (P=0.037) and (P=0.034), respectively, suggesting that bone maturation processed faster in irradiated bone. These findings suggest that LLLT might have a favourable effect on healing and attachment of titanium implants.


Dose and Wavelength of Laser Light Have Influence on the Repair of Cutaneous Wounds.
Journal of Clinical Laser Medicine & Surgery. 2004; 22 (1):19-25.
Mendez T; Pinheiro A; Pacheco M; Nascimento P;Ramalho L.

The objective of the present study was to compare histologically the effect of GaAlAs (? 830 nm, ~ 2 mm2, 35 mW) and InGaAlP (? 685 nm, ~ 2 mm2, 35 mW) lasers, alone or in association with doses of 20 or 50 J/cm2 on cutaneous wounds in the dorsum of the Wistar rat. The healing time of surgical wounds is of extreme importance and it is usually associated with a post-operative period free of infection and with less pain and inflammation. Sixty Wistar rats were divided into seven groups: Group I - control (non-irradiated); Group II - ? 685 nm, 20 J/cm2; Group III - ? 830 nm, 20 J/cm2; Group IV - ? 685 nm and ? 830 nm, 20 J/cm2; Group V - ? 685 nm, 50 J/cm2); Group VI - ? 830 nm, 50 J/cm2; and Group VII - ? 685 nm and 830 nm, 50 J/cm2. The animals were sacrificed 3, 5, and 7 days after surgery. Light microscopic analysis using H&E and Picrosírius stains showed that, at the end of the experimental period, irradiated subjects showed increased collagen production and organization when compared to non-irradiated controls. Inflammation was still present in all groups at this time. Group IV (? 830 nm and ? 685 nm, 20 J/cm2) presented better results at the end of the experimental period. It is concluded that low-level light therapy (LLLT) can have a positive biomodulatory effect on the repair of cutaneous wounds.


Polychromatic LED Therapy in Burn Healing of Non-diabetic and Diabetic Rats
Author(s): Farouk A. H. Al-Watban MSc, PhD ; Bernard L. Andres RMT, MT(AMT)
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21 Number: 5 Page: 249 -- 258
DOI: 10.1089/104454703322564451

Abstract: Objective: We determined the effect of polychromatic light-emitting diodes (LED) in burn healing of non-diabetic and streptozotocin-induced diabetic rats. Background Data: LEDs were used as the light source for phototherapy. Materials and Methods: The polychromatic LED is a cluster of 25 diodes emitting photons at wavelengths of 510-543, 594-599, 626-639, 640-670, and 842-879 nm with 272-mW output power. Age-matched, male Sprague-Dawley rats (n = 30) were used. Streptozotocin (70 mg/kg) was used for diabetes induction. Rat weight, hyperglycemia, and glycosuria were monitored for the first 3 days and weekly thereafter. Rats were anesthetized and shaved after 1 week of diabetes. Burn areas of 1.5 ± .03 cm2 were created using a metal rod pre-heated up to 600°C that was applied for 2 sec. Diabetic and non-diabetic rats were randomized into the following treatment groups: control, 5, 10, 20, and 30 J/cm2. Light treatment commenced after burn infliction and was repeated three times per week. Burn areas were measured daily. Results: Burn healing was impaired significantly during diabetes by -46.17%. Polychromatic LED treatment using 5, 10, 20, and 30 J/cm2 incident doses influenced healing by 6.85%, 4.93%, -4.18%, and -5.42% in the non-diabetic rats; and 73.87%, 76.77%, 60.92%, and 48.77% in the diabetic rats, relative to their controls, respectively. Conclusion: The effect of polychromatic LED in non-diabetic rats was insignificant; however, it simulated the trend of stimulation and inhibition seen using low-level lasers. Significant stimulation observed in the diabetic rats demonstrated the usefulness of polychromatic LED in diabetic burn healing.


Effects of Pulse Frequency of Low-Level Laser Therapy (LLLT) on Bone Nodule Formation in Rat Calvarial Cells
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21 Number: 5 Page: 271 -- 277
DOI: 10.1089/104454703322564479
Author(s): Yuji Ueda ; Noriyoshi Shimizu

Abstract: Objective: The purpose of this study was to determine the effect of pulse frequencies of low-level laser therapy (LLLT) on bone nodule formation in rat calvarial cells in vitro. Background Data: Various photo-biostimulatory effects of LLLT, including bone formation, were affected by some irradiation factors such as total energy dose, irradiation phase, laser spectrum, and power density. However, the effects of pulse frequencies used during laser irradiation on bone formation have not been elucidated. Materials and Methods: Osteoblast-like cells isolated from fetal rat calvariae were irradiated once with a low-energy Ga-Al-As laser (830 nm, 500 mW, 0.48-3.84 J/cm2) in four different irradiation modes: continuous irradiation (CI), and 1-, 2-, and 8-Hz pulsed irradiation (PI-1, PI-2, PI-8). We then investigated the effects on cellular proliferation, bone nodule formation, alkaline phosphatase (ALP) activity, and ALP gene expression. Results: Laser irradiation in all four groups significantly stimulated cellular proliferation, bone nodule formation, ALP activity, and ALP gene expression, as compared with the non-irradiation group. Notably, PI-1 and -2 irradiation markedly stimulated these factors, when compared with the CI and PI-8 groups, and PI-2 irradiation was the best approach for bone nodule formation in the present experimental conditions. Conclusion: Since low-frequency pulsed laser irradiation significantly stimulates bone formation in vitro, it is most likely that the pulse frequency of LLLT an important factor affecting biological responses in bone formation.

Effects of Low-Level Laser Therapy (LLLT) of 810 nm upon in Vitro Growth of Bacteria: Relevance of Irradiance and Radiant Exposure
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21 Number: 5 Page: 283 -- 290
DOI: 10.1089/104454703322564497
Author(s): Ethne L. Nussbaum PhD, MEd, BScPT ; Lothar Lilge PhD ; Tony Mazzulli MD, FRCPC

Abstract: Objective: The aim of this study was to investigate the irradiance-dependency of low-level laser therapy (LLLT) effects on bacterial growth. Background: LLLT is applied to open wounds to improve healing; however, its effect on wound bacteria is not well understood. Materials and Methods: Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were irradiated using a wavelength of 810 nm at irradiances of 0.015 W/cm2 (0-50 J/cm2) and 0.03 W/cm2 (0-80 J/cm2). Bacteria were counted after 20 h of incubation. Results: LLLT effects varied significantly with species. P.aeruginosa growth decreased overall dependent on an interaction of irradiance and radiant exposure; greatest inhibition was produced using high irradiance delivering radiant exposures in the range of 1-20 J/cm2 (p = 0.001-0.04). In contrast, E. coli growth increased overall (p = 0.01), regardless of irradiance; greatest effects were produced using low radiant exposures (1-20 J/cm2). There was a main effect for irradiance (p = 0.03) on S. aureus growth; however, growth was not different compared with controls. Additional analysis showed that there were differences in growth of P.aeruginosa when comparing samples that were matched by exposure times (66, 329, 658, 1316, 1974, and 2632 sec) rather than radiant exposure; this suggests that irradiance rather than exposure time was the significant factor in P. aeruginosa inhibition. Conclusion: These findings have immediate relevancy in the use of LLLT for infected wounds. Exposure to 810-nm irradiation (0.03 W/cm2) could potentially benefit wounds infected with P. aeruginosa. However, increased E. coli growth could further delay recovery.

Effect of the Clinical Application of the GaAlAs Laser in the Treatment of Dentine Hypersensitivity
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21 Number: 5 Page: 291 -- 296
DOI: 10.1089/104454703322564505
Author(s): Ana Lucia Marsilio DDS, MS, PhD ; José Roberto Rodrigues DDS, MS, PhD ; Alessandra Bühler Borges DDS, MS, PhD

Abstract: Objective: The aim of this study was to evaluate the effectiveness of the clinical use of the gallium-aluminum-arsenium (GaAlAs) laser at the maximum and minimum energies recommended by the manufacturer for the treatment of dentine hypersensitivity. Background Data: Dentine hypersensitivity (DH) is a response to a stimulus that would not usually cause pain in a healthy tooth. It is characterized by sharp pain of short duration from the denuded dentin. Its etiology is unknown. The dentin only begins to show sensitivity when exposed to the buccal environment. This exposure can result after removal of the enamel and/or dental cement, or after root denudation. Different treatments are proposed for this disorder. Materials and Methods: In this study, 25 patients, with a total number of 106 cases of DH, were treated with GaAlAs low-level laser therapy (LLLT). 65% of the teeth were premolars; 14% were incisors and molars; 6.6% were canines. The teeth were irradiated with 3 and 5 J/cm2 for up to six sessions, with an interval of 72 h between each application, and they were evaluated initially, after each application, and at 15 and 60 days follow-up post-treatment. Results: The treatment was effective in 86.53% and 88.88% of the irradiated teeth, respectively, with the minimum and maximum energy recommended by the manufacturer. There was a statistically significant difference between DH and after a follow-up of 60 days for both groups. The difference among the energy maximum and minimum was not significant. Conclusion: The GaAlAs low-level laser was effective in reducing initial DH. A significant difference was found between initial values of hypersensitivity and after 60 days follow-up post-treatment. No significant difference was found between minimum (3 J/cm2) and maximum (5 J/cm2) applied energy.

Effect of Low-Power Radiation (Helium/Neon) upon Submandibulary Glands
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21 Number: 4 Page: 219 -- 225
DOI: 10.1089/104454703768247792
Author(s): Luis M. Plavnik DDM ; Marta E. De Crosa DDM ; Alicia I. Malberti PhD

Abstract: Objective: The aim of this work was to study the effect of low-power laser radiation on guinea pig salivary glands. Background Data: Low-power laser radiation changes some cellular functions. The effect on salivary glands has not been sufficiently studied. Materials and Methods: One hundred and forty-four male guinea pigs (150 ± 30 g body weight) were used. The animals were divided into two groups: control group (fed animals and those undergoing 2, 4, 8, 10, and 12 h of fasting) and experimental group (irradiated). Both the right and left submandibular glands were later irradiated with helium-neon laser at 7-mW power, with a 0.75-mm spot, under continuous pulse for 2 min in a one-session exposure; a 11.2 J/cm2 energy density was applied. Then, the irradiated animals were fed, or underwent 2, 4, 8, 10 and 12 h of fasting. Samples of submandibular glands were taken with a punch (5 mm diameter) and were used for optic and transmission electron microscopy studies. Results: The structural observations showed that the irradiation effect was progressive; and showed a trophic stimulant effect at 2 h following irradiation, with vasodilatation, vascular congestion, perivascular infiltrate, and a necrotic picture of glandular parenchyma at longer times. The ultrastructural observations showed alterations of rough endoplasmic reticulum. Conclusion: We propose that low-power laser radiation with the doses applied in this study disturbs protein synthesis and secretion of guinea pig submandibulary glands.

Low-Level Laser Irradiation Attenuates Production of Reactive Oxygen Species by Human Neutrophils
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21 Number: 3 Page: 165 -- 170
DOI: 10.1089/104454703321895635
Author(s): Yuji Fujimaki MD ; Tadashi Shimoyama PhD ; Qiang Liu PhD ; Takashi Umeda PhD ; Shigeyuki Nakaji PhD ; Kazuo Sugawara PhD

Abstract: Objective: The aim of this study was to examine the effects of low-level laser therapy (LLLT) on production of reactive oxygen (ROS) species by human neutrophils. Background Data: LLLT is an effective therapeutic modality for inflammatory conditions. Materials and Methods: The laser device used was the infrared diode laser (GaAlAs), 830-nm continuous wave (150 mW/cm2). After irradiation, ROS production by neutrophils was measured using luminol-dependent chemiluminescence (LmCL) and expression of CD11b and CD16 on neutrophil surface was measured by flow cytometry. Results: The LmCL response of neutrophils was reduced by laser irradiation at 60 min prior to the stimulation with opsonized zymosan and calcium ionophore. The attenuating effect of LLLT was larger in neutrophils of smokers than non-smokers, while the amount of produced ROS was larger in neutrophils of smokers. Expression of CD11b and CD16 on neutrophil surface was not affected by LLLT. Conclusion: Attenuation of ROS production by neutrophils may play a role in the effects of LLLT in the treatment of inflammatory tissues. There is a possible usage of LLLT to improve wound healing in smokers.

Effect of NASA Light-Emitting Diode Irradiation on Molecular Changes for Wound Healing in Diabetic Mice
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21 Number: 2 Page: 67 -- 74
DOI: 10.1089/104454703765035484
Author(s): Harry T. Whelan MD ; Ellen V. Buchmann BS ; Apsara Dhokalia PhD ; Mary P. Kane BS ; Noel T. Whelan BS ; Margaret T.T. Wong-Riley PhD ; Janis T. Eells PhD ; Lisa J. Gould MD, PhD ; Rasha Hammamieh PhD ; Rina Das PhD ; Marti Jett PhD

Abstract: Objective: The purpose of this study was to assess the changes in gene expression of near-infrared light therapy in a model of impaired wound healing. Background Data: Light-Emitting Diodes (LED), originally developed for NASA plant growth experiments in space, show promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. In this paper we present the effects of LED treatment on wounds in a genetically diabetic mouse model. Materials and Methods: Polyvinyl acetal (PVA) sponges were subcutaneously implanted in the dorsum of BKS.Cg-m +/+ Leprdb mice. LED treatments were given once daily, and at the sacrifice day, the sponges, incision line and skin over the sponges were harvested and used for RNA extraction. The RNA was subsequently analyzed by cDNA array. Results: Our studies have revealed certain tissue regenerating genes that were significantly upregulated upon LED treatment when compared to the untreated sample. Integrins, laminin, gap junction proteins, and kinesin superfamily motor proteins are some of the genes involved during regeneration process. These are some of the genes that were identified upon gene array experiments with RNA isolated from sponges from the wound site in mouse with LED treatment. Conclusion: We believe that the use of NASA light-emitting diodes (LED) for light therapy will greatly enhance the natural wound healing process, and more quickly return the patient to a preinjury/illness level of activity. This work is supported and managed through the Defense Advanced Research Projects Agency (DARPA) and NASA Marshall Space Flight Center-SBIR Program.


Influence of Linearly Polarized Near-Infrared Irradiation on Deformability of Human Stored Erythrocytes
Source: Journal of Clinical Laser Medicine & Surgery Volume: 21 Number: 1 Page: 19 -- 22
DOI: 10.1089/10445470360516699
Author(s): Kozo Yokoyama DDS, PhD ; Kazuna Sugiyama DDS, PhD

Abstract: Objective: To investigate the influence of linearly polarized near-infrared irradiation using the Super Lizer™ on deformability of human erythrocytes. Background Data: Not only low-powered laser but also linearly polarized near-infrared beams have some biostimulation effects on various tissues. There were some reports of erythrocyte deformability improved by low-powered He-Ne laser irradiation. Materials and Methods: Human erythrocyte samples stored for three weeks were adjusted to 30% hematocrit. Erythrocyte deformability presented as the filter filtration rate was measured. Results: There was no difference of the filter filtration rate between control group without irradiation and the group of 125 mJ/cm2 exposure level at a wavelength of 830 nm. However, the groups of 625 and 1,250 mJ/cm2 exposure levels at a wavelength of 830 nm showed higher filter filtration rates compared to the control group. Conclusion: Linearly polarized near-infrared irradiation in a range of 625-1,250 mJ/cm2 exposure level at a wavelength of 830 nm improved deformability of human stored erythrocytes.

The Comparison of Effects between Pulsed and CW Lasers on Wound Healing
Source: Journal of Clinical Laser Medicine & Surgery Volume: 22 Number: 1 Page: 15 -- 18
DOI: 10.1089/104454704773660921
Author(s): Farouk A.H. Al-Watban MSc, PhD ; X.Y. Zhang MD

Abstract: Objective: In order to evaluate the effects of pulsed continuous wave (CW) laser and detect the role of wound healing in rats using both pulsed and CW 635-nm low-level laser therapy (LLLT), a pilot study was undertaken. Background Data: Some acceleration effects of wound healing on animals were found after treatment using various lasers with CW. There are other reports, however, using pulsed CW laser to evaluate the effects of wound healing in rats. Materials and Methods: An elliptic wound was created aseptically with a scalpel on the shaved back of the rats after anesthesia. The rats treated were restrained in a Plexiglas cage without anesthesia during the laser irradiation period. An Erchonia pulse laser (635 nm) was used in the experiment. The laser beam was delivered through an expander. The percentage of relative wound healing was calculated. Results: The percentage of relative wound healing was 4.32 in 100 Hz, 3.21 in 200 Hz, 3.83 in 300 Hz, 2.22 in 400 Hz, 1.73 in 500 Hz and 4.81 in CW. Conclusion: LLLT using pulsed, CW laser at the appropriate dosimetry and frequency can provide acceleration in wound healing in rats. The 100-Hz frequency had a better effect than other pulse frequencies used in the study. The effects of treatment using CW laser was higher than pulse frequency. The frequency of pulsed CW laser was not found to increase wound healing in rats compared with normal CW laser, as reported in our previous studies

NASA Light-Emitting Diodes for the Prevention of Oral Mucositis in Pediatric Bone Marrow Transplant Patients
Source: Journal of Clinical Laser Medicine & Surgery Volume: 20 Number: 6 Page: 319 -- 324
DOI: 10.1089/104454702320901107
Author(s): Harry T. Whelan MD ; James F. Connelly MD ; Brian D. Hodgson DDS ; Lori Barbeau DDS ; A. Charles Post DDS ; George Bullard DDS ; Ellen V. Buchmann BS ; Mary Kane BS ; Noel T. Whelan BS ; Ann Warwick MD ; David Margolis MD

Abstract: Objective: The purpose of this study was to determine the effects of prophylactic near-infrared light therapy from light-emitting diodes (LEDs) in pediatric bone marrow transplant (BMT) recipients. Background Data: Oral mucositis (OM) is a frequent side effect of chemotherapy that leads to increased morbidity. Near-infrared light has been shown to produce biostimulatory effects in tissues, and previous results using near-infrared lasers have shown improvement in OM indices. However, LEDs may hold greater potential for clinical applications. Materials and Methods: We recruited 32 consecutive pediatric patients undergoing myeloablative therapy in preparation for BMT. Patients were examined by two of three pediatric dentists trained in assessing the Schubert oral mucositis index (OMI) for left and right buccal and lateral tongue mucosal surfaces, while the patients were asked to rate their current left and right mouth pain, left and right xerostomia, and throat pain. LED therapy consisted of daily treatment at a fluence of 4 J/cm2 using a 670-nm LED array held to the left extraoral epithelium starting on the day of transplant, with a concurrent sham treatment on the right. Patients were assessed before BMT and every 2-3 days through posttransplant day 14. Outcomes included the percentage of patients with ulcerative oral mucositis (UOM) compared to historical epidemiological controls, the comparison of left and right buccal pain to throat pain, and the comparison between sides of the buccal and lateral tongue OMI and buccal pain. Results: The incidence of UOM was 53%, compared to an expected rate of 70-90%. There was also a 48% and 39% reduction of treated left and right buccal pain, respectively, compared to untreated throat pain at about posttransplant day 7 (p < 0.05). There were no significant differences between sides in OMI or pain. Conclusion: Although more studies are needed, LED therapy appears useful in the prevention of OM in pediatric BMT patients.

Effects of 630-, 660-, 810-, and 905-nm Laser Irradiation Delivering Radiant Exposure of 1-50 J/cm2 on Three Species of Bacteria in Vitro
Author(s): Ethne L. Nussbaum MEd, PhD ; Lothar Lilge PhD ; Tony Mazzulli MD, FRCPC
Source: Journal of Clinical Laser Medicine & Surgery Volume: 20 Number: 6 Page: 325 -- 333
DOI: 10.1089/104454702320901116

Abstract: Objective: To examine the effects of low-intensity laser therapy (LILT) on bacterial growth in vitro. Background Data: LILT is undergoing investigation as a treatment for accelerating healing of open wounds. The potential of coincident effects on wound bacteria has received little attention. Increased bacterial proliferation could further delay recovery; conversely inhibition could be beneficial. Materials and Methods: Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus were plated on agar and then irradiated with wavelengths of 630, 660, 810, and 905 nm (0.015 W/cm2) and radiant exposures of 1-50 J/cm2. In addition, E. coli was irradiated with 810 nm at an irradiance of 0.03 W/cm2 (1-50 J/cm2). Cells were counted after 20 h of incubation post LILT. Repeated measures ANOVA and Tukey adjusted post hoc tests were used for analysis. Results: There were interactions between wavelength and species (p = 0.0001) and between wavelength and radiant exposure (p = 0.007) in the overall effects on bacterial growth; therefore, individual wavelengths were analyzed. Over all types of bacteria, there were overall growth effects using 810- and 630-nm lasers, with species differences at 630 nm. Effects occurred at low radiant exposures (1-20 J/cm2). Overall effects were marginal using 660 nm and negative at 905 nm. Inhibition of P. aeruginosa followed irradiation using 810 nm at 5 J/cm2 (-23%; p = 0.02). Irradiation using 630 nm at 1 J/cm2 inhibited P. aeruginosa and E. coli (-27%). Irradiation using 810 nm (0.015 W/cm2) increased E. coli growth, but with increased irradiance (0.03 W/cm2) the growth was significant (p = 0.04), reaching 30% at 20 J/cm2 (p = 0.01). S. aureus growth increased 27% following 905-nm irradiation at 50 J/cm2. Conclusion: LILT applied to wounds, delivering commonly used wavelengths and radiant exposures in the range of 1-20 J/cm2, could produce changes in bacterial growth of considerable importance for wound healing. A wavelength of 630 nm appeared to be most commonly associated with bacterial inhibition. The findings of this study might be useful as a basis for selecting LILT for infected wounds.

Contraindications in Noninvasive Laser Therapy: Truth and Fiction
Author(s): Leos Navratil MD, PhD ; Jaroslava Kymplova MD, PhD
Source: Journal of Clinical Laser Medicine & Surgery Volume: 20 Number: 6 Page: 341 -- 343
DOI: 10.1089/104454702320901134

Abstract: Objective: Noninvasive laser therapy is a treatment method employed in many disciplines. This review article points out instances when it appears to be effective to administer such therapy. Materials and Methods: Noninvasive laser therapy has a number of suitable applications that cause minimal damage to the patient. Many patients are not sent to institutions equipped with relevant instruments, since physicians are burdened by a number of contraindications, many of which are incorrect. The purpose of this article was to divide these contraindications into the following three groups: correct indications, indications doubtful under certain conditions, and incorrect indications. Discussion: We consider the following contraindications as correct: history of a histologically demonstrated malignant carcinoma; irradiation of the neck region in hyperthyreosis; epilepsy; exposure of the retina; and exposure of the abdomen during pregnancy. The contraindications that are doubtful under certain conditions are as follows: fever and infectious diseases; certain blood diseases; heavy blood losses; neuropathies; and irradiation in the region of gonads. The other contraindications reported in the literature are considered to be incorrect.


Low-Intensity Laser Therapy/Combined Phototherapy in the Management of Chronic Venous Ulceration: A Placebo-Controlled Study
Author(s): Katie M. Lagan DPhil ; Toni McKenna BSc ; Anne Witherow RGN, PgDip(wound healing) ; Jean Johns BSc ; Suzanne M. McDonough PhD ; G. David Baxter DPhil
Source: Journal of Clinical Laser Medicine & Surgery Volume: 20 Number: 3 Page: 109 -- 116
DOI: 10.1089/104454702760090173

Abstract: Objective: The current placebo-controlled study was undertaken to investigate the efficacy of combined phototherapy and low-intensity laser therapy (LILT) in the management of chronic venous ulceration when used in conjunction with standardized nursing intervention. Materials and Methods: Approval was granted by Research Ethical Committees at the University of Ulster and Altnagelvin Hospitals Health and Social Services Trust. Patients (n = 15; 10 female/5 male; age ± SD = 69.9 ± 13.8 years) were recruited from an outpatient "leg ulcer clinic," where they attended once per week for irradiation/sham treatments for 4 weeks. Treatment was withheld for a total of 8 weeks, and patients were reviewed during this time (weeks 8 and 12) for ulcer and pain assessment only. A multisource diode array (660-950 nm) was used for irradiation; parameters were kept constant for the duration of the study (532 mW; 5 kHz; 12 J/cm2). Wound and pain assessment were carried out by an independent investigator. Digitizing was used to quantify surface areas from wound tracings. Results: Although there was no statistically significant difference between Treatment and Placebo groups, an apparent clinical difference in wound healing rate was noted; at postirradiation, a continued reduction in wound size was evident for the treatment group. These effects were believed to be due to an apparent delayed effect. There was no statistically significant difference between groups for pain. Conclusion: These findings provide only limited evidence for the use of this modality as an adjunctive therapy with current nursing intervention. Further group studies are indicated to investigate the apparent delayed effect reported here for various etiologies of ulceration.

TI Therapeutic photobiomodulation for methanol-induced retinal toxicity.
AU Eells-J-T, Henry-M-M, Summerfelt-P, Wong-Riley-M-T-T, Buchmann-E-V,
Kane-M, Whelan-N-T, Whelan-H-T.
IN J.T. Eells, Department of Pharmacology, Medical College of Wisconsin,
8701 Watertown Plank Road, Milwaukee, WI 53226, United States
e-mail: jeells@mcw.edu.
SO Proceedings of the National Academy of Sciences of the United States
of America {PROC-NATL-ACAD-SCI-U-S-A}, 18 MAR 2003, Vol/Iss/Pg. 100/6
(3439-3444), ISSN: 0027-8424.

AB Methanol intoxication produces toxic injury to the retina and optic nerve, resulting in blindness. The toxic metabolite in methanol intoxication is formic acid, a mitochondrial toxin known to inhibit
the essential mitochondrial enzyme, cytochrome oxidase. Photobiomodulation by red to near-IR radiation has been demonstrated to enhance mitochondrial activity and promote cell survival in vitro
by stimulation of cytochrome oxidase activity. The present studies were undertaken to test the hypothesis that exposure to monochromatic red radiation from light-emitting diode (LED) arrays would protect the retina against the toxic actions of methanol-derived formic acid in a rodent model of methanol toxicity. Using the electroretinogram as a sensitive indicator of retinal function, we demonstrated that three brief (2 min, 24 s) 670-nm LED treatments (4 J/cm(2)), delivered at 5, 25, and 50 h of methanol intoxication, attenuated the retinotoxic effects of methanol-derived formate. Our studies document a significant recovery of rod- and cone-mediated function in LED-
treated, methanol-intoxicated rats. We further show that LED treatment protected the retina from the histopathologic changes induced by methanol-derived formate. These findings provide a link
between the actions of monochromatic red to near-IR light on mitochondrial oxidative metabolism in vitro and retinoprotection in vivo. They also suggest that photobiomodulation may enhance recovery from retinal injury and other ocular diseases in which mitochondrial dysfunction is postulated to play a role.

 

Selected abstracts from April 2004

Effects of Low-level Laser Therapy in HIV/AIDS-positive Patients After Exodontic
Procedures. Journal of Oral Laser Applications. 2003; 3 (2): 109-115.
Giovanni E M, Ferreira M C D, Souza R S et al

The purpose of this study was to verify the efficiency of the GaAlAs laser in the stimulation of tissue repair and analgesic effect after tooth extractions in HIV/AIDS-positive patients. A low-level (790 nm, 30 mw) laser was applied in 15 HIV/AIDS-positive patients who required extractions totalling 36 teeth. Platelet count, T-CD4 lymphocytes, and the viral load of each patient were examined. After extraction and suturing, the low-potency laser beam was applied to the surgical area parallel to the long axis of the alveolus for a period of 2 min. All the patients were instructed not to use any medications or supplementary treatments. The postoperative exam was performed 8 days after surgery, including the suture removal, periapical radiograph, area wound healing evaluation, and a questionnaire to evaluate postoperative pain. The patients generally reported a comfortable postoperative period. If pain was present, it was very slight and required no medication or other therapy. The process of tissue regeneration and surgical wound healing took less time than with conventional procedures. Although the patients presented various degrees of immune suppression as measured by the T-CD4 lymphocyte count, and some had a high viral load, all responded satisfactorily in the postoperative period.


Effects of infrared and low-power laser irradiation on cell viability, glutathione and glutathionerelated enzyme activities in primary rat hepatocytes.
J Formos Med Assoc. 2003; 102 (7): 486-491.
Kao M J, Sheen L Y.

Both infrared and low-power laser have been applied to improve circulation, wound repair, and pain control. Infrared and low-power laser therapies have the potential for stimulating enzyme activities which might contribute to increased glutathione (GSH) concentration and provide protection against oxidative damage. This study investigated cell viability, and GSH and its related enzyme activities in rat hepatocytes after irradiation. Hepatocytes were isolated from 8-week-old male Sprague-Dawley rats and the cultures were divided into infrared, laser, and control groups. The cells were treated with infrared and low-power laser at a distance of 35 cm for 20 minutes. The cell morphology, lactate dehydrogenase (LDH) leakage, lipid peroxidation, GSH concentration, GSH peroxidase, GSH reductase (GRd), and GSH S-transferase activities were measured after irradiation. The morphology and LDH leakage of hepatocytes in the irradiation groups did not differ significantly from those of the control group. After infrared irradiation, a significant decrease in thiobarbituric acid-reactive substances and an increase in GSH concentration were found after 48 hours of incubation compared to the control group (p < 0.05). Furthermore, laser irradiation resulted in a significant increase in GRd activity after 48 hours of incubation compared to the control group (p < 0.05). A 48-hour incubation period produced greater GRd activity in all groups compared to a 24-hour period (p < 0.05).: Irradiation did not damage rat hepatocytes in this study. Infrared was shown to stimulate GSH production, while laser irradiation increased GRd activity.

Laser light prevents apoptosis in Cho K-1 cell line.
J Clin Laser Med Surg. 2003; 21 (4): 193-196.
Carnevalli CM, Soares CP, Zangaro RA, Pinheiro AL, Silva NS.

The present study investigated the effects of low-level laser therapy (LLLT) on the mitochondria, nucleus, and cytoskeleton of CHO K-1 cells by the use of specific fluorescent probes. The use of LLLT has been recommended by several authors for acceleration of the healing process. The literature on the effects of LLLT in this process is highly contradictory because of difficulties in identifying its effects on cells. CHO K-1 cells were cultivated using MEM containing 5% FBS and were irradiated or not with a semiconductor laser (lambda = 830 nm; phi approximately 0.8 mm; 10 mW; 2 J/cm2). The cells were incubated with specific fluorescent