Literature Watch April 2008

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

Institute of Physiotherapy, Faculty of Health and Social Sciences, Bergen University College, Moellendalsvn, 6, 5009 Bergen, Norway.
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 doses.

BMC Musculoskelet Disord 2008 9 75

Electrophysiologic Effects of a Therapeutic Laser on Myofascial Trigger Spots of Rabbit Skeletal Muscles.

Chen KH, Hong CZ, Kuo FC, Hsu HC, Hsieh YL

From the Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Chiayi, Taiwan (K-HC, H-CH); College of Medicine, Chang Gung University, Taoyuan, Taiwan (K-HC, H-CH); and Department of Physical Therapy, HungKuang University, Taichung, Taiwan (C-ZH, F-CK); and the Department of Physical Therapy, Graduate Institute of Rehabilitation Science, China Medical University, Taichung, Taiwan (Y-LH).

OBJECTIVE:: To better understand the mechanisms of therapeutic lasers for treating human myofascial trigger points, we designed a blinded controlled study of the effects of a therapeutic laser on the prevalence of endplate noise (EPN) recorded from the myofascial trigger spot (MTrS) of rabbit skeletal muscle. DESIGN:: In eight rabbits, one MTrS in each biceps femoris muscle was irradiated with a 660-nm, continuous-wave, gallium-aluminum-arsenate (GaAlAs) laser, at 9 J/cm. The contralateral side of muscle was treated with a sham laser. Each rabbit received six treatments. The immediate and cumulative effects were assessed by the prevalence of EPN with electromyographic (EMG) recordings after the first and last treatments. RESULTS:: Compared with pretreatment values, the percentages of EPN prevalence in the experimental side after the first and last treatments were significantly reduced (P < 0.01 for both). The change in EPN prevalence in the experimental side was significantly greater than in the control side immediately after the first and last treatments (P < 0.05). However, no significant differences were noted between the first and last treatments (P > 0.05). CONCLUSIONS:: In our study, immediate and cumulative effects of a GaAlAs laser applied on MTrS were demonstrated on the basis of the assessment of EPN prevalence. It seems that laser irradiation may inhibit the irritability of an MTrS in rabbit skeletal muscle. This effect may be a possible mechanism for myofascial pain relief with laser therapy.

Am J Phys Med Rehabil 2008 Jul 9

Effect of laser phototherapy on the release of fibroblast growth factors by human gingival fibroblasts.

Damante CA, De Micheli G, Miyagi SP, Feist IS, Marques MM

Departamento de Periodontia, Faculdade de Odontologia, Universidade de Sao Paulo, Sao Paulo, Brazil.

The effects of laser phototherapy on the release of growth factors by human gingival fibroblasts were studied in vitro. Cells from a primary culture were irradiated twice (6 h interval), with continuous diode laser [gallium-aluminum-arsenium (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP),_660 nm] in punctual and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). Positive [10% fetal bovine serum (FBS)] and negative (1%FBS) controls were not irradiated. Production of keratinocyte growth factor (KGF) and basic fibroblast growth factor (bFGF) was quantified by enzyme-linked immunosorbent assay (ELISA). The data were statistically compared by analysis of variance (ANOVA) followed by Tukey’s test (P </= 0.05). The characterization of the cell line indicated a mesenchymal nature. KGF release was similar in all groups, while that of bFGF was significantly greater (1.49-times) in groups treated with infra-red laser. It was concluded that increased production of bFGF could be one of the mechanisms by which infra-red laser stimulates wound healing.

Lasers Med Sci 2008 Jul 4

Low-level laser therapy improves vision in patients with age-related macular degeneration.

Ivandic BT, Ivandic T

University of Heidelberg, Otto-Meyerhof Centre, Heidelberg.

GermanyAbstract Objective: The objective of this study of a case series was to examine the effects of low-level laser therapy (LLLT) in patients with age-related macular degeneration (AMD). Background Data: AMD affects a large proportion of the elderly population; current therapeutic options for AMD are limited, however. Patients and Methods: In total, 203 patients (90 men and 113 women; mean age 63.4 +/- 5.3 y) with beginning (dry) or advanced (wet) forms of AMD (n = 348 eyes) were included in the study. One hundred ninety-three patients (mean age 64.6 +/- 4.3 y; n = 328 eyes) with cataracts (n = 182 eyes) or without cataracts (n = 146 eyes) were treated using LLLT four times (twice per week). A semiconductor laser diode (780 nm, 7.5 mW, 292 Hz, continuous emission) was used for transconjunctival irradiation of the macula for 40 sec (0.3 J/cm(2)) resulting in a total dose of 1.2 J/cm(2). Ten patients (n = 20 eyes) with AMD received mock treatment and served as controls. Visual acuity was measured at each visit. Data were analyzed retrospectively using a t-test. Results: LLLT significantly improved visual acuity (p < 0.00001 versus baseline) in 162/182 (95%) of eyes with cataracts and 142/146 (97%) of eyes without cataracts. The prevalence of metamorphopsia, scotoma, and dyschromatopsia was reduced. In patients with wet AMD, edema and bleeding improved. The improved vision was maintained for 3-36 mo after treatment. Visual acuity in the control group remained unchanged. No adverse effects were observed in those undergoing therapy. Conclusion: In patients with AMD, LLLT significantly improved visual acuity without adverse side effects and may thus help to prevent loss of vision.

Photomed Laser Surg 2008 Jun 26(3) 241-5

Influence of laser photobiomodulation upon connective tissue remodeling during wound healing.

Medrado AP, Soares AP, Santos ET, Reis SR, Andrade ZA

Laboratory of Experimental Pathology, Oswaldo Cruz Foundation, Rua Waldemar Falcao, 121, Salvador, Bahia 40.296-710, Brazil.

The modulation of collagen fibers during experimental skin wound healing was studied in 112 Wistar rats submitted to laser photobiomodulation treatment. A standardized 8mm-diameter wound was made on the dorsal skin of all animals. In half of them, 0.2ml of a silica suspension was injected along the border of the wound in order to enhance collagen deposition and facilitate observation. The others received saline as vehicle. The treatment was carried out by means of laser rays from an aluminum-gallium arsenide diode semiconductor with 9mW applied every other day (total dose=4J/cm(2)) on the borders of the wound. Tissue sections obtained from four experimental groups representing sham-irradiated animals, laser, silica and the association of both, were studied after 3, 7, 10, 15, 20, 30 and 60 days from the laser application. The wounded skin area was surgically removed and submitted to histological, immunohistochemical, ultrastructural, and immunofluorescent studies. Besides the degree and arrangement of collagen fibers and of their isotypes, the degree of edema, the presence of several cell types especially pericytes and myofibroblasts, were described and measured. The observation of Sirius-red stained slides under polarized microscopy revealed to be of great help during the morphological analysis of the collagen tissue dynamic changes. It was demonstrated that laser application was responsible for edema regression and a diminution in the number of inflammatory cells (p<0.05). An evident increase in the number of actin-positive cells was observed in the laser-treated wounds. Collagen deposition was less than expected in silica-treated wounds, and laser treatment contributed to its better differentiation and modulation in all irradiated groups. Thus, laser photobiomodulation was able to induce several modifications during the cutaneous healing process, especially in favoring newly-formed collagen fibers to be better organized and compactedly disposed.

J Photochem Photobiol B 2008 Jul 3

Influence of low-level laser therapy on biomaterial osseointegration: a mini-review.

Obradovic RR, Kesic LG, Pesevska S

Department of Oral Medicine and Periodontology, Dental Clinic, Faculty of Medicine, University of Nis, Bul. Nikole Tesle 45/19, 18000, Nis, Serbia,

The aim of this paper is to provide an overview of the available literature on low-level laser therapy (LLLT) and its influence on bone repair and the osseointegration of biomaterials. Extensive studies of alveolar bone repair, a common problem in periodontal therapy, have been conduced worldwide. The utility of LLLT in biomaterial osseointegration is still unanswered, due to lack of literature and poorly understood mechanisms. It is still difficult for one to compare studies about the action of LLLT on the osseointegration of biomaterials because the experimental models and duration of treatments are very distinct. However, it could be concluded that LLLT may offer advantages in terms of periodontal and bone functional recovery and biomaterial osseointegration.

Lasers Med Sci 2008 Jun 20

Low-Intensity Laser Irradiation Improves the Mitochondrial Dysfunction of C2C12 Induced by Electrical Stimulation.

Xu X, Zhao X, Liu TC, Pan H

Laboratory of Laser Sports Medicine, College of Sports Sciences, South China Normal University, Guangzhou, China.

Abstract Objective: We investigated the effects of electrical stimulation and low-intensity laser (LIL) energy on the mitochondrial function of cultured C2C12 myotubes in order to find a dosage that could be used to improve the function of mitochondria, and then rehabilitate exercise-induced damage and fatigue. Background Data: Many other studies in the past demonstrated that LIL had a cytoprotective effect, and a recent study also found that LIL could reduce muscular fatigue during tetanic contractions in rats. Methods: Cultured C2C12 myotubes were subjected to electrical stimulation or/and LIL irradiation at various intensities. Reactive oxygen species (ROS) were detected with a fluorescent probe (DCFH-DA) and mitochondrial function was assessed with an MTT assay. Results: The results showed that electrical stimulation at 20 ms, 5 Hz, and 45 V for 75 min can induce mitochondrial dysfunction in cultured C2C12 myotubes. Electrical stimulation-induced mitochondrial dysfunction was improved, but degeneration occurred with LIL at doses of 0.33-8.22 and 11.22-14.16 J/cm(2), respectively, and these changes were markedly increased with LIL at 0.33 and 1.34 J/cm(2), respectively. Conclusions: We conclude that treatment of myotubes with the proper dosage of LIL irradiation significantly diminished production of ROS and restored mitochondrial function, and this may provide a foundation for the use of photobiomodulation to treat exercise-induced mitochondrial dysfunction or skeletal muscular fatigue.

Photomed Laser Surg 2008 Jun 26(3) 197-202

Low-power laser irradiation activates Src tyrosine kinase through reactive oxygen species-mediated signaling pathway.

Zhang J, Xing D, Gao X

MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou, China.

Low-power laser therapy in medicine is widespread but the mechanisms are not fully understood. It has been suggested that low-power laser irradiation (LPLI) could induce photochemical reaction and activate several intracellular signaling pathways. Reactive oxygen species (ROS) are considered to be the key secondary messengers produced by LPLI. Here, we studied the signaling pathway mediated by ROS upon the stimulation of LPLI. Src tyrosine kinases are well-known targets of ROS and can be activated by oxidative events. Using a Src reporter based on fluorescence resonance energy transfer (FRET) and confocal laser scanning microscope, we visualized the dynamic Src activation in Hela cells immediately after LPLI. Moreover, Src activation by LPLI was in a dose-dependent manner. The increase of Src phosphorylation at Tyr416 was detected by Western blotting. In the presence of vitamin C, catalase alone, or the combination of catalase and superoxide dismutase (SOD), the activation of Src by LPLI is significantly abolished. In contrast, Go6983 loading, a PKC inhibitor, did not affect this response. Treatment of Hela cells with exogenous H(2)O(2) also resulted in a concentration-dependent activation of Src. These results demonstrated that it was ROS that mediated Src activation by LPLI. Cellular viability assay revealed that laser irradiation of low doses (</=25 J/cm(2)) promoted Hela cells viability while high doses impaired. Therefore, LPLI induces ROS-mediated Src activation which may play an important role in biostimulatory effect of LPLI. J. Cell. Physiol. (c) 2008 Wiley-Liss, Inc.

J Cell Physiol 2008 Jul 9

Low-power laser treatment in patients with frozen shoulder: preliminary results.

Stergioulas  A

Laboratory of Health, Fitness, and Rehabilitation Management, Faculty of Humam Movement and Quality of Life, Peloponnese University, Sparta, Greece, and Peania Physical Therapy Center, Attica, Greece.

ABSTRACT Objective: In this study I sought to test the efficacy of low-power laser therapy (LLLT) in patients with frozen shoulder. Background Data: The use of low-level laser energy has been recommended for the management of a variety of musculoskeletal disorders. Materials and Methods: Sixty-three patients with frozen shoulder were randomly assigned into one of two groups. In the active laser group (n = 31), patients were treated with a 810-nm Ga-Al-As laser with a continuous output of 60 mW applied to eight points on the shoulder for 30 sec each, for a total dose of 1.8 J per point and 14.4 J per session. In the placebo group (n = 32), patients received placebo laser treatment. During 8 wk of treatment, the patients in each group received 12 sessions of laser or placebo, two sessions per week (for weeks 1-4), and one session per week (for weeks 5-8). Results: Relative to the placebo group, the active laser group had: (1) a significant decrease in overall, night, and activity pain scores at the end of 4 wk and 8 wk of treatment, and at the end of 8 wk additional follow-up (16 wk post-randomization); (2) a significant decrease in shoulder pain and disability index (SPADI) scores and Croft shoulder disability questionnaire scores at those same intervals; (3) a significant decrease in disability of arm, shoulder, and hand questionnaire (DASH) scores at the end of 8 wk of treatment, and at 16 wk posttreatment; and (4) a significant decrease in health-assessment questionnaire (HAQ) scores at the end of 4 wk and 8 wk of treatment. There was some improvement in range of motion, but this did not reach statistical significance. Conclusions: The results suggested that laser treatment was more effective in reducing pain and disability scores than placebo at the end of the treatment period, as well as at follow-up.

Photomed Laser Surg 2008 Apr 26(2) 99-105

Effect of low-level laser therapy in the inflammatory response induced by Bothrops jararacussu snake venom.

Barbosa  AM, Villaverde  AB, Guimaraes-Souza  L, Ribeiro  W, Cogo  JC, Zamuner  SR

Laboratory of Inflammation, Institute of Research and Development, University of Vale do Paraiba, Av. Shishima Hifumi, 2911, Urbanova, CEP 12244-000, Sao Jose dos Campos, SP, Brazil.

This article reports the effect of low-level laser therapy (LLLT) on the edema formation and leukocyte influx caused by Bothrops jararacussu snake venom as an alternative treatment for Bothrops snakebites. The inflammatory reaction was induced by injection of 0.6mg/kg of B. jararacussu venom, in gastrocnemius muscle. Cell influx and edema were evaluated at 3 or 24h after venom injection. Mice were irradiated at the site of injury by a low-level laser (685nm) with a dose of 4.2J/cm(2). A therapy that combines LLLT and antivenom was also studied. B. jararacussu venom caused a significant edema formation 3 and 24h after its injection, and a prominent leukocyte infiltrate composed predominantly of neutrophils at 24h after venom inoculation. LLLT significantly reduced edema formation by 53% and 64% at 3 and 24h, respectively, and resulted in a reduction of neutrophils accumulation (P<0.05). The combined therapy showed to be more efficient than each therapy acting separately. In conclusion, LLLT significantly reduced the edema and leukocyte influx into the envenomed muscle, suggesting that LLLT should be considered as a potentially therapeutic approach for the treatment of the local effects of Bothrops species.

Toxicon 2008 Mar 10

Comparison of 3 physical therapy modalities for acute pain in lumbar disc herniation measured by clinical evaluation and magnetic resonance imaging.

Unlu  Z, Tasci  S, Tarhan  S, Pabuscu  Y, Islak  S

Department of Physical Medicine and Rehabilitation, Medical Faculty, Celal Bayar University, Manisa, Turkey.

OBJECTIVE: This study measures and compares the outcome of traction, ultrasound, and low-power laser (LPL) therapies by using magnetic resonance imaging and clinical parameters in patients presenting with acute leg pain and low back pain caused by lumbar disc herniation (LDH). METHODS: A total of 60 patients were enrolled in this study and randomly assigned into 1 of 3 groups equally according to the therapies applied, either with traction, ultrasound, or LPL. Treatment consisted of 15 sessions over a period of 3 weeks. Magnetic resonance imaging examinations were done before and immediately after the treatment. Physical examination of the lumbar spine, severity of pain, functional disability by Roland Disability Questionnaire, and Modified Oswestry Disability Questionnaire were assessed at baseline, immediately after, and at 1 and 3 months after treatment. RESULTS: There were significant reductions in pain and disability scores between baseline and follow-up periods, but there was not a significant difference between the 3 treatment groups at any of the 4 interview times. There were significant reductions of size of the herniated mass on magnetic resonance imaging after treatment, but no differences between groups. CONCLUSIONS: This study showed that traction, ultrasound, and LPL therapies were all effective in the treatment of this group of patients with acute LDH. These results suggest that conservative measures such as traction, laser, and ultrasound treatments might have an important role in the treatment of acute LDH.

Efficacy of Low-Level Laser Therapy for Chronic Cutaneous Ulceration in Humans: A Review and Discussion.

Sobanko  JF, Alster  TS

Departments of Dermatology, Georgetown University Hospital and Washington Hospital Center, Washington, DC, USA.

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.

Dermatol Surg 2008 Apr 22

Biophysics behavior of acupuncture points irradiated with low energy lasers.

Moldovan  C

National Acupuncture & Homeopathy Centre, Bucharest, Romania.

This work describes the Low Energy Laser (LEL) coherent light interaction with the skin cover on acupuncture loci for the purpose of detecting and measuring the spatial and temporal alteration of the thermal, electric and optical properties of the LI4 (HEGU) acupoint, irradiated with a 685 nm, 30 mW, III.B Laser. Novel electrostatic imaging technique, an original Acupuncture 3-D Thermal and Electric Mapping Technique and an original Method for Laser-Skin Reflectance, were used in the study. The results indicate that the visible laser light, with low frequency and low power, specifically modify the 3-D pattern of the temperature, electric potential and electric impedance outline of an acupuncture point, meanwhile with a significant decrease of the laser reflectance index, all measured on a 27 apparently healthy subject lot (48 years mean age, 54% male), when comparing with a non-active, non-acupunctural skin area, placed on the volar side of the same hand. The biophysical method presented, combines in a complex way and reproducible the electro stasis exploration (bioelectric homeostasis), with cutaneous thermodynamic exploration and photo-optical exploration of the derma and provides information that can be appreciated in dynamics and compared depending on the exploration target.

Rom J Intern Med 2007 45(3) 281-5

The combined treatment effects of therapeutic laser and exercise on tendon repair.

Ng  GY, Fung  DT

Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.

ABSTRACT Objective: In this study we investigated the effects of different intensities of therapeutic laser energy and running exercise, and their combined effects on the repair of Achilles tendons in rats. Materials and Methods: Thirty-six mature Sprague-Dawley rats that received surgical hemi-transection of their right Achilles tendon were tested. Three laser dosages (4 J/cm(2), 1 J/cm(2) and 0 J/cm(2)) and three running periods (30 min, 15 min, and 0 min) resulting in nine different dosage and time groups were studied with four rats in each group. The treatments were given on alternate days starting on day 5 post-injury. On day 22, the tendons were tested for load-relaxation, stiffness, and ultimate strength. Results: There was a significant effect of laser energy on normalized load-relaxation, the rats receiving 4 J/cm(2) had less load-relaxation than those receiving no laser treatment (p = 0.05). Results of stiffness testing revealed a significant effect, and rats that ran for 30 min had more stiffness than those that did not run (p = 0.015). For ultimate strength, due to a significant interaction (p = 0.05), the two factors were analyzed separately, and the results showed that for rats receiving no laser therapy, those that had run for 15 min and 30 min had more strength than those that did not run (p = 0.02 and 0.04, respectively). Conclusions: Both laser therapy and running were found to hasten Achilles tendon repair In general, the rats that received higher dosages of laser energy (4 J/cm(2)) and ran for longer periods (30 min) performed better than those that received lower dosages of laser energy and ran for shorter periods.

Photomed Laser Surg 2008 Apr 26(2) 137-41

Bone repair following bone grafting hydroxyapatite guided bone regeneration and infra-red laser photobiomodulation: a histological study in a rodent model.

Pinheiro  AL, Martinez Gerbi  ME, de Assis Limeira  F Jr, Carneiro Ponzi  EA, Marques  AM, Carvalho  CM, de Carneiro Santos  R, Oliveira  PC, Noia  M, Ramalho  LM

Department of Propedeutica and Clinica Integrada, Laser Center, School of Dentistry, Federal University of Bahia, Salvador, BA, Brazil,

The aim of the investigation was to assess histologically the effect of laser photobiomodulation (LPBM) on a repair of defects surgically created in the femurs of rats. Forty-five Wistar rats were divided into four groups: group I (control); group II (LPBM); group III (hydroxyapatite guided bone regeneration; HA GBR); group IV (HA GBR LPBM). The animals in the irradiated groups were subjected to the first irradiation immediately after surgery, and it was repeated every day for 2 weeks. The animals were killed 15 days, 21 days and 30 days after surgery. When the groups irradiated with implant and membrane were compared, it was observed that the repair of the defects submitted to LPBM was also processed faster, starting from the 15th day. At the 30th day, the level of repair of the defects was similar in the irradiated groups and those not irradiated. New bone formation was seen inside the cavity, probably by the osteoconduction of the implant, and, in the irradiated groups, this new bone formation was incremental. The present preliminary data seem to suggest that LPMB therapy might have a positive effect upon early wound healing of bone defects treated with a combination of HA and GBR.

Lasers Med Sci 2008 Apr 17

Effect of laser radiation on production of reactive oxygen species in the blood of patients with chronic obstructive pulmonary disease.

Farkhutdinov  UR, Farkhutdinov  ShU

Department of Pulmonology, Clinical Hospital No. 21, Ufa.

RussiaThe effect of laser radiation on generation of reactive oxygen species in the whole blood from patients with chronic obstructive pulmonary disease was studied by in vitro recording of luminol-dependent chemiluminescence. Laser irradiation of the blood from patients with increased production of reactive oxygen species decreased the microbicidal potential of cells. In patients with low generation of reactive oxygen species and normal potential of cells, laser exposure increased production of O2 metabolites. Laser radiation had little effect on chemiluminescence of the blood in patients with low generation of reactive oxygen species and decreased functional activity of cells.

Bull Exp Biol Med 2007 Aug 144(2) 238-40

A comparative study of the effects of laser photobiomodulation on the healing of third-degree burns: a histological study in rats.

Meirelles  GC, Santos  JN, Chagas  PO, Moura  AP, Pinheiro  AL

Laser Center, School of Dentistry, Department of Propedeutics and Integrated Clinics, Universidade Federal da Bahia, Salvador.

ABSTRACT Objective: The aim of this investigation was to compare by light microscopy the effects of laser photobiomodulation at wavelengths of 660 and 780 nm on third-degree burns in Wistar rats. Background Data: Burns are severe injuries that result in the loss of fluid and destruction of tissue, infection, and shock that may result in death. Laser energy has been suggested as an effective method to improve wound healing. Materials and Methods: Fifty-five animals were used in this study. A third-degree burn measuring 1.5 x 1.5 cm was created on the dorsum of each animal. The animals were divided into three subgroups according the type of laser photobiomodulation they received (wavelength of 660 or 780 nm, 35 mW, theta = 2 mm, and 20 J/cm(2)). In the animals receiving treatment, it was begun immediately post-burn at four points around the burn (5 J/cm(2)) and repeated at 24-h intervals for 21 d. The animals were humanely killed after 3, 5, 7, 14, and 21 d by an intraperitoneal overdose of general anesthetic. The specimens were routinely cut and stained, and then were analyzed by light microscopy. Results: The results showed more deposition of collagen fibers, larger amounts of granulation tissue, less edema, a more vigorous inflammatory reaction, and increased revascularization on all laser-treated animals. These features were more evident at early stages when the 660-nm laser was used, and were more evident throughout the experimental period for the animals receiving 780-nm laser therapy. Conclusion: We concluded that laser photobiomodulation using both wavelengths improved healing of third-degree burns on Wistar rats.

Photomed Laser Surg 2008 Apr 26(2) 159-66

Infrared Laser Light Further Improves Bone Healing When Associated with Bone Morphogenetic Proteins and Guided Bone Regeneration: An in Vivo Study in a Rodent Model.

Pinheiro  AL, Gerbi  ME, Ponzi  EA, Ramalho  LM, Marques  AM, Carvalho  CM, Santos  RD, Oliveira  PC, Noia  M

Laser Center, School of Dentistry, Department of Propedeutica and Clinica Integrada, Universidade Federal da Bahia, Salvador, and Instituto de Pequisa e Desenvolvimento (IPD), Vale do Paraiba University, Sao Jose dos Campos, Salvador, Brazil.

ABSTRACT Objective: This study assessed histologically the effect of laser photobiomodulation on the repair of surgical defects created in the femurs of Wistar rats treated or not treated with bone morphogenetic proteins (BMPs) and organic bovine bone graft. Background Data: This paper is part of an ongoing series of works in which biomaterials and/or guided bone regeneration (GBR) are used in association with laser photobiomodulation. Several previous reports from our group have shown that the use of laser photobiomodulation improves the treatment of bone defects. Materials and Methods: Forty-eight adult male Wistar rats were divided into four randomized groups: group 1 (controls, n = 12); group 2 (laser photobiomodulation, n = 12); group 3 (BMPs + organic bovine bone graft + GBR, n = 12); and group 4 (BMPs + organic bovine bone graft + GBR + laser photobiomodulation, n = 12). The irradiated groups received seven irradiations every 48 h, the first immediately after the surgical procedure. Laser photobiomodulation (830 nm, 40 mW, CW, phi approximately 0.6 mm) consisted of a total of 16 J/cm(2) per session at four points (4 J/cm(2) each) equally spaced around the periphery of the defect. The animals were sacrificed after 15, 21, and 30 d, and the specimens were routinely embedded in wax and stained with hematoxylin and eosin and Sirius red stains and analyzed under light microscopy. Results: The results showed histological evidence of increased deposition of collagen fibers (at 15 and 21 d), as well as an increased amount of well-organized bone trabeculi at the end of the experimental period (30 d) in irradiated animals compared to non-irradiated controls. Conclusion: We concluded that the use of laser photobiomodulation in association with BMPs, organic bovine bone grafts, and GBR increases the positive biomodulating effects of laser energy.

Photomed Laser Surg 2008 Mar 16

Initial effects of low-level laser therapy on growth and differentiation of human osteoblast-like cells.

Stein  E, Koehn  J, Sutter  W, Wendtlandt  G, Wanschitz  F, Thurnher  D, Baghestanian  M, Turhani  D

Department of Cranio-Maxillofacial and Oral Surgery, Medical University of Vienna, Austria.

Low-level laser therapy is a clinically well established tool for enhancement of wound healing. In vitro studies have also shown that low level laser therapy has a biostimulatory effect on cells of different origin. The aim of this in vitro study was to investigate the initial effect of low-level laser therapy on growth and differentiation of human osteoblast-like cells. SaOS-2 cells were irradiated with laser doses of 1 J/cm(2) and 2 J/cm(2) using a diode laser with 670 nm wave length and an output power of 400 mW. Untreated cells were used as controls. At 24 h, 48 h and 72 h post irradiation, cells were collected and assayed for viability of attached cells and alkaline phosphatase specific activity. In addition, mRNA expression levels of osteopontin and collagen type I were assessed using semi-quantitative RT-PCR. Over the observation period, cell viability, alkaline phosphatase activity and the expression of osteopontin and collagen type I mRNA were slightly enhanced in cells irradiated with 1 J/cm(2) compared with untreated control cells. Increasing the laser dose to 2 J/cm(2) reduced cell viability during the first 48 h and resulted in persistently lower alkaline phosphatase activity compared with the other two groups. The expression of osteopontin and collagen type I mRNA slightly decreased with time in untreated controls and cells irradiated with 1 J/cm(2), but their expression was increased by treatment with 2 J/cm(2) after 72 h. These results indicate that low-level laser therapy has a biostimulatory effect on human osteoblast-like cells during the first 72 h after irradiation. Further studies are needed to determine the potential of low-level laser therapy as new treatment concept in bone regeneration.

Wien Klin Wochenschr 2008 Feb 120(3-4) 112-117

Low-energy helium-neon laser therapy induces repigmentation and improves the abnormalities of cutaneous microcirculation in segmental-type vitiligo lesions.

Wu  CS, Hu  SC, Lan  CC, Chen  GS, Chuo  WH, Yu  HS

Department of Dermatology, Kaohsiung Medical University Hospital, and Department of Dermatology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.

Segmental vitiligo (SV) is a special form of vitiligo occurring in a dermatomal distribution, and an abnormality involving the sympathetic nerves supplying the affected dermatome is known to underlie this disorder. Previously, we have shown that SV is associated with an abnormal increase in cutaneous blood flow and adrenoceptor responses in the affected areas. Since SV is resistant to conventional forms of therapy, its management represents a challenge for dermatologists. Low energy helium-neon lasers (He-Ne laser, wavelength 632.8 nm) have been employed as a therapeutic instrument in many clinical situations, including vitiligo management and repair of nerve injury. The purpose of this study was to evaluate the effectiveness and safety of He-Ne lasers in treating SV, and determine their effects on the repair of sympathetic nerve dysfunction. Forty patients with stable-stage SV on the head and/or neck were enrolled in this study. He-Ne laser irradiation was administered locally at 3.0 J/cm2 with point stimulation once or twice weekly. Cutaneous microcirculatory assessments in six SV patients were performed using a laser Doppler flowmeter. The sympathetic adrenoceptor response of cutaneous microcirculation was determined by measuring cutaneous blood flow before, during and after iontophoresis with sympathomimetic drugs (phenylephrine, clonidine and propranolol). All measurements of microcirculation obtained at SV lesions were simultaneously compared with contralateral normal skin, both before and after He-Ne laser treatment. After an average of 17 treatment sessions, initial repigmentation was noticed in the majority of patients. Marked repigmentation (> 50%) was observed in 60% of patients with successive treatments. Cutaneous blood flow was significantly higher at SV lesions compared with contralateral skin, but this was normalized after He-Ne laser treatment. In addition, the abnormal decrease in cutaneous blood flow in response to clonidine was improved by He-Ne laser therapy. Our study showed that He-Ne laser therapy is an effective treatment for SV by normalizing dysfunctions of cutaneous blood flow and adrenoceptor responses in SV patients. Thus, the beneficial effects of He-Ne laser therapy may be mediated in part by a reparative effect on sympathetic nerve dysfunction.

Kaohsiung J Med Sci 2008 Apr 24(4) 180-9

Low Level Laser Therapy (LLLT) Decreases Pulmonary Microvascular Leakage, Neutrophil Influx and IL-1beta Levels in Airway and Lung from Rat Subjected to LPS-Induced Inflammation.

Aimbire  F, Ligeiro de Oliveira  AP, Albertini  R, Correa  JC, Ladeira de Campos  CB, Lyon  JP, Silva  JA Jr, Costa  MS

Instituto de Pesquisa & Desenvolvimento-IP&D, Universidade do Vale do Paraiba-UNIVAP, Av. Shishima Hifumi, 2911, CEP: 12244-000, Sao Jose dos Campos, Sao Paulo

BrazilBACKGROUND AND OBJECTIVE: Low level laser therapy (LLLT) is a known anti-inflammatory therapy. Herein we studied the effect of LLLT on lung permeability and the IL-1beta level in LPS-induced pulmonary inflammation. STUDY DESIGN/METHODOLOGY: Rats were divided into 12 groups (n = 7 for each group). Lung permeability was measured by quantifying extravasated albumin concentration in lung homogenate, inflammatory cells influx was determined by myeloperoxidase activity, IL-1beta in BAL was determined by ELISA and IL-1beta mRNA expression in trachea was evaluated by RT-PCR. The rats were irradiated on the skin over the upper bronchus at the site of tracheotomy after LPS. RESULTS: LLLT attenuated lung permeability. In addition, there was reduced neutrophil influx, myeloperoxidase activity and both IL-1beta in BAL and IL-1beta mRNA expression in trachea obtained from animals subjected to LPS-induced inflammation. CONCLUSION: LLLT reduced the lung permeability by a mechanism in which the IL-1beta seems to have an important role.

Inflammation 2008 Jun 31(3) 189-97

Low-level laser therapy decreases levels of lung neutrophils anti-apoptotic factors by a NF-kappaB dependent mechanism.

Aimbire  F, Santos  FV, Albertini  R, Castro-Faria-Neto  HC, Mittmann  J, Pacheco-Soares  C

Institute of Research and Development – IP&D – UNIVAP. Av. Shishima Hifumi, 2911, CEP: 12244-000, Sao Jose dos Campos – SP, Brazil.

BACKGROUND AND OBJECTIVE: Low-level laser therapy (LLLT) is a known modulator of inflammatory process. Herein we studied the effect of 660 nm diode laser on mRNA levels of neutrophils anti-apoptotic factors in lipopolysaccharide (LPS)-induced lung inflammation. STUDY DESIGN/METHODOLOGY: Mice were divided into 8 groups (n=7 for each group) and irradiated with energy dosage of 7.5 J/cm(2). The Bcl-xL and A1 mRNA levels in neutrophils were evaluated by Real Time-PCR (RT-PCR). The animals were irradiated after exposure time of LPS. RESULTS: LLLT and an inhibitor of NF-kappaB nuclear translocation (BMS 205820) attenuated the mRNA levels of Bcl-xL and A1 mRNA in lung neutrophils obtained from mice subjected to LPS-induced inflammation. CONCLUSION: LLLT reduced the levels of anti-apoptotic factors in LPS inflamed mice lung neutrophils by an action mechanism in which the NF-kappaB seems to be involved.

Int Immunopharmacol 2008 Apr 8(4) 603-5

Clinical Evaluation of a 1,450-nm Diode Laser as Adjunctive Treatment for Refractory Facial Acne Vulgaris.

Astner  S, Tsao  SS

Department of Dermatology, Wellman Center of Photomedicine, Massachusetts Generasl Hospital, Boston, MA, USA.

BACKGROUND Despite aggressive multitreatment medical acne regimens, many patients demonstrate modest benefit. The 1,450-nm diode laser has been shown to improve acne in a study setting. OBJECTIVE Herein we evaluate the use of this laser as an adjunctive tool in the management of refractory facial acne vulgaris. MATERIALS AND METHODS Thirteen patients were treated. Lesion counts, clinical evaluation, and digital photography were performed at baseline and at all follow-up visits. Patients received an average of three treatments. Acne severity index and patient satisfaction were assessed. Patients continued their medical acne regimen where applicable. RESULTS Mean total lesion and inflammatory lesion counts decreased from 66 +/- 14 and 23 +/- 5 at baseline to 34 +/- 12.9 and 14 +/- 7 after three treatments (p<.05). Side effects were mild, including erythema lasting up to 24 hours. CONCLUSION The 1,450-nm diode laser provides moderate improvement of refractory acne vulgaris. Our findings support the use of this device as an adjunctive treatment for acne management.

Dermatol Surg 2008 May 6

Low-level laser therapy (670 nm) on viability of random skin flap in rats.

Bossini  PS, Fangel  R, Habenschus  RM, Renno  AC, Benze  B, Zuanon  JA, Neto  CB, Parizotto  NA

Department of Physiotherapy, Federal University of Sao Carlos, Sao Carlos, SP, Brazil.

This study investigated the effects of 670 nm laser, at different fluences, on the viability of skin flap in rats. One hundred male animals were used. The animals were divided into control group; group treated with 3 J/cm(2); group treated with 6 J/cm(2); group treated with 12 J/cm(2) and group treated with 24 J/cm(2). The skin flap was made on the backs of all animals studied, with a plastic sheet interposed between the flap and the donor site. Laser irradiation was done immediately after the surgery and on days 1, 2, 3 and 4 after surgery. The percentage of necrosis of the flap was calculated at the 7th postoperative day. Additionally, a sample of each flap was collected to enable us to count the blood vessels. Treated animals showed a statistically significant smaller area of necrosis than did the control group. The necrosis in the treated groups was 41.82% (group 2), 36.51% (group 3), 29.45% (group 4) and 20.37% (group 5). We also demonstrated that laser irradiation at 670 nm, at all doses used, had a stimulatory effect on angiogenesis. Our study showed that the 670 nm laser was efficient to increase the viability of the skin flap, at all fluences used, with a tendency of reaching better results at higher doses.

Lasers Med Sci 2008 Mar 20

Histological and clinical studies on the effects of low to medium level infrared light therapy on human and mouse skin.

Kameyama  K

Aoyama Dermatology Clinic, Tokyo, Japan

BACKGROUND AND OBJECTIVE: Deep heating or denaturation of collagen has been reported to be necessary for nonablative skin rejuvenation. The purpose of this study was to examine whether thermally damaged collagen is an indispensable factor to increase the amount of collagen in vivo. Epidermal and dermal responses to infrared light therapy using a Titan source were examined with the aim of correlating histological and clinical responses in human and amelanotic mouse skin. STUDY DESIGN/MATERIALS AND METHODS: Ten, 20, or 30 J/cm2 infrared light were irradiated on the human subject’s skin (thigh), while 5, 10, 20, or 30 J/cm2 were used on amelanotic mouse skin. Biopsies were taken and analyzed using hematoxylin and eosin (H&E) and Elastica von Gieson stain. RESULTS: Ten or 20 J/cm2 infrared light increased the amount of both collagen and elastin in all layers of the dermis without denaturing the collagen in human skin. A higher dose of 30 J/cm2 also increased the amount of collagen and elastin, but denatured the collagen in human skin. (In addition to the thigh, 2 treatments of 10 J/cm2 infrared light improved skin toning and texture on the subject’s face). In mouse skin, 5 or 10 J/cm2 remarkably increased the amount of both collagen and elastin, and of epidermal cells. Twenty or 30 J/cm increased the amount of collagen and elastin and the number of keratinocytes, but caused some vacuolated degeneration of keratinocytes. The presence of denatured collagen was not evident due to the high density of collagen. CONCLUSIONS: This study shows that the denaturation of collagen is not required to increase the amounts of collagen or elastin in vivo in human skin. The activation of the mitochondria as well as the denaturation of collagen may play important roles in infrared phototherapy.

J Drugs Dermatol 2008 Mar 7(3) 230-5

Laser in the treatment of hypertrophic burn scars.

Kawecki  M, Bernad-Wisniewska  T, Sakiel  S, Nowak  M, Andriessen  A

Burn Center, Jana Pawla II 2, 41-100, Siemianowice Slaskie, Poland.

This prospective study looked at the outcome of laser (light amplification by stimulated emission of radiation) treatment for hypertrophic scarring. Dermatrade mark K laser (a set of combined lasers erbium:yttrium aluminium garnet/carbon dioxide, qualified as a class IV laser) was used. Between 21 June 2000 and 19 November 2002, at the Siemianowice Burn Center, Poland, 592 interventions, using laser, were performed on N= 327 patients (220 women and 107 men, aged between 3 and 80 years). The majority of cases [N= 223 (68.9%)] were patients with post-burn hypertrophic scars, and 104 cases (31.8%) had various types of hypertrophic scars. Evaluation took place using an adapted Vancouver Scar Scale and digital photographs as well as the patient’s opinion. It was noted that after laser treatment, satisfactory results were achieved in 72% of cases. The scars had become less red (192/327 scored no redness at the end of the study versus 92/327 upon initial), less raised (272/327 scored a flat scar versus 72/327 upon initial) and demonstrated an improved viscoelasticity (192/327 scored a soft skin versus 62/327 upon initial). Laser treatment did not improve contractures in post-burn hypertrophic scars. Results were not confirmed using objective measurement tools, as these were not available to us.

Int Wound J 2008 Mar 5(1) 87-97

Acne phototherapy with a 1450-nm diode laser: an open study.

Konishi  N, Endo  H, Oiso  N, Kawara  S, Kawada  A

Department of Dermatology, Kinki University School of Medicine Ohno-Higashi 377-2, Osaka-Sayama city, Osaka 589-8511, Japan.

The purpose of this study was to investigate the efficacy of phototherapy with a newly-developed 1450-nm diode laser in patients with mild to moderate acne. An open study was performed in acne patients who were treated up to five times with a two week interval. Acne lesions were reduced by 63%. Only one patient discontinued treatment due to vesicle formation as an adverse effect. Phototherapy using this diode laser source was effective and well tolerated in acne patients, suggesting that this phototherapy may be a new modality for the treatment of acne.

Ther Clin Risk Manag 2007 Mar 3(1) 205-9

Handheld LED array device in the treatment of acne vulgaris.

Sadick  NS

Weill Medical College of Cornell University, Department of Dermatology, New York, NY, USA

The successful treatment of acne still remains problematic. Conventional therapies often prove inconsistent with unacceptable side effects and recurrence rates, leading to patient noncompliance. A thermal phototherapy treatment using a combination of blue light and red light has recently attracted much attention and seems to offer an effective alternative. The objective of this study was to evaluate the efficacy of blue light (415 nm) in combination with red light (633 nm) in the reduction of inflammatory lesions on the face of subjects (n=21) with mild to moderate acne vulgaris after a course of 8 20-minute (blue) or 30-minute (red) alternated light treatments, self-administered by a handheld unit over a period of 4 weeks. Lesion counts progressively reduced throughout the 4-week light therapy period and continued to reduce up to 8 weeks posttherapy, with a final average reduction of 69% seen 8 weeks after the treatment course (P>.001). This pattern is similar to previously reported studies.

J Drugs Dermatol 2008 Apr 7(4) 347-50

Literature news.

Sardella  A

Dipartimento di Medicina, Chirurgia e Odontoiatria, Via Beldiletto 1, 20142 Milano, Italy.

AIM: To evaluate the clinical effects of laser therapy on the prevention and reduction of oral mucositis in patients who underwent hematopoietic stem cell transplantation (HSCT).Patients and methods: From January 2003 to September 2004, 24 patients received prophylactic laser therapy (L+ group). The applications started from the beginning of the conditioning regimen up to day +2. The oral assessment was performed daily until day +30. This group was compared with historical controls, namely 25 patients, who did not receive laser therapy (L? group). RESULTS: All patients developed some grade of mucositis. However, the L? group presented initial mucositis by 4.36 days, whereas the L+ group presented it in 6.12 days (P = 0.01). The maximum mucositis occurred between day +2 and day +6 with healing by day +25 in the L? group and between day +2 and day +7 with healing by day +14 for the L+ group (P = 0.84). Laser therapy also reduced the time of oral pain from 5.64 to 2.45 days (P = 0.04), and decreased the consumption of morphine (P = 0.07). CONCLUSION: This study suggests that laser therapy can be useful in oral mucositis to HSCT patients and improve the patient’s quality of life. However, controlled randomized trials should be performed to confirm the real efficacy of laser therapy.

Minerva Stomatol 2008 Jan-Feb 57(1-2) 77-8

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