Latest LLLT / Cold Laser Literature watch with abstracts Jan 09

Our latest LLLT literature review with 20 abstracts including another muscle fatigue paper from Brazil, two Oral Mucositis papers, a “strong” rating for laser on myofascial trigger points in a Chiropractic systematic review and a Carpal Tunnel Syndrome clinical trial paper.

Low-level infrared laser therapy in chemotherapy-induced oral mucositis: a randomized placebo-controlled trial in children.

Kuhn A, Porto FA, Miragliaz P, Brunetto AL

Pediatric Oncology Unit, Hospital de Clinicas de Porto Alegre, Federal University of Rio Grande do Sul, Brazil.

BACKGROUND: Oral mucositis (OM) is one of the most frequent complications of chemotherapy for which there is no standard therapy; treatment is mostly conservative. This study was conducted to determine whether low-intensity laser therapy (LLLT) can reduce the duration of chemotherapy-induced OM. PROCEDURE: A placebo-controlled randomized trial was carried out using LLLT or placebo (sham treatment). Children and adolescents with cancer receiving chemotherapy or hematopoietic stem-cell transplantation between October 2005 and May 2006 were eligible as soon as they developed OM. Patients received intervention for 5 days. The LLLT group was treated with laser GaAlAs, wavelength (lambda): 830 nm (infrared), power: 100 mW, dose: 4 J/cm, and placebo group underwent sham treatment. The grade of OM was clinically assessed by the National Cancer Institute, Common Toxicity Criteria scale. RESULTS: Twenty-one patients developed OM and were evaluable for analysis; 18 (86%) patients had a diagnosis of leukemia or lymphoma and 3(14%) had solid tumors. The mean age was 8.2 (+/-3.1) years. Nine patients were randomized in the laser group and 12 in the placebo-control group. Once OM was diagnosed, the patients had daily OM grading assessments before laser or sham application and thereafter until complete healing of the lesions. On day 7 after OM diagnosis, 1/9 of patients remained with lesions in laser group and 9/12 of patients in the placebo-control group (P=0.029). In the laser group, the mean of OM duration was 5.8+/-2 days and in the placebo group was 8.9+/-2.4 days (P=0.004). CONCLUSIONS: Our study has shown evidence that laser therapy in addition to oral care can decrease the duration of chemotherapy-induced OM. Our results confirm the promising results observed in adult cancer patients and should encourage pediatric oncologists to use laser therapy as first-line option in children with chemotherapy-induced OM.

J Pediatr Hematol Oncol 2009 Jan 31(1) 33-7

Chiropractic management of myofascial trigger points and myofascial pain syndrome: a systematic review of the literature.

Vernon H, Schneiderz M

Canadian Memorial Chiropractic College, Ontario, Canada.

OBJECTIVES: Myofascial pain syndrome (MPS) and myofascial trigger points (MTrPs) are important aspects of musculoskeletal medicine, including chiropractic. The purpose of this study was to review the most commonly used treatment procedures in chiropractic for MPS and MTrPs. METHODS: The Scientific Commission of the Council on Chiropractic Guidelines and Practice Parameters (CCGPP) was charged with developing literature syntheses, organized by anatomical region, to evaluate and report on the evidence base for chiropractic care. This article is the outcome of this charge. As part of the CCGPP process, preliminary drafts of these articles were posted on the CCGPP Web site (2006-8) to allow for an open process and the broadest possible mechanism for stakeholder input. PubMed, Excerpta Medica Database, Cumulative Index to Nursing and Allied Health Literature, and databases for systematic reviews and clinical guidelines were searched. Separate searches were conducted for (1) manual palpation and algometry, (2) chiropractic and other manual therapies, and (3) other conservative and complementary/alternative therapies. Studies were screened for relevance and rated using the Oxford Scale and Scottish Intercollegiate Guidelines Network rating system. RESULTS: A total of 112 articles were identified. Review of these articles resulted in the following recommendations regarding treatment: Moderately strong evidence supports manipulation and ischemic pressure for immediate pain relief at MTrPs, but only limited evidence exists for long-term pain relief at MTrPs. Evidence supports laser therapy (strong), transcutaneous electrical nerve stimulation, acupuncture, and magnet therapy (all moderate) for MTrPs and MPS, although the duration of relief varies among therapies. Limited evidence supports electrical muscle stimulation, high-voltage galvanic stimulation, interferential current, and frequency modulated neural stimulation in the treatment of MTrPs and MPS. Evidence is weak for ultrasound therapy. CONCLUSIONS: Manual-type therapies and some physiologic therapeutic modalities have acceptable evidentiary support in the treatment of MPS and TrPs.

J Manipulative Physiol Ther 2009 Jan 32(1) 14-24

Effect of 830 nm low-level laser therapy applied before high-intensity exercises on skeletal muscle recovery in athletes.

Leal Junior EC, Lopes-Martins RA, Baroni BM, De Marchi T, Taufer D, Manfro DS, Rech M, Danna V, Grosselli D, Generosi RA, Marcoz RL, Ramos L, Bjordal JM

Laboratory of Human Movement (LMH), Sports Medicine Institute (IME), University of Caxias do Sul (UCS), Rua Francisco Getulio Vargas, 1130, 95070-560, Caxias do Sul, RS, Brazil,

Our aim was to investigate the immediate effects of bilateral, 830 nm, low-level laser therapy (LLLT) on high-intensity exercise and biochemical markers of skeletal muscle recovery, in a randomised, double-blind, placebo-controlled, crossover trial set in a sports physiotherapy clinic. Twenty male athletes (nine professional volleyball players and eleven adolescent soccer players) participated. Active LLLT (830 nm wavelength, 100 mW, spot size 0.0028 cm(2), 3-4 J per point) or an identical placebo LLLT was delivered to five points in the rectus femoris muscle (bilaterally). The main outcome measures were the work performed in the Wingate test: 30 s of maximum cycling with a load of 7.5% of body weight, and the measurement of blood lactate (BL) and creatine kinase (CK) levels before and after exercise. There was no significant difference in the work performed during the Wingate test (P > 0.05) between subjects given active LLLT and those given placebo LLLT. For volleyball athletes, the change in CK levels from before to after the exercise test was significantly lower (P = 0.0133) for those given active LLLT (2.52 U l(-1) +/- 7.04 U l(-1)) than for those given placebo LLLT (28.49 U l(-1) +/- 22.62 U l(-1)). For the soccer athletes, the change in blood lactate levels from before exercise to 15 min after exercise was significantly lower (P < 0.01) in the group subjected to active LLLT (8.55 mmol l(-1) +/- 2.14 mmol l(-1)) than in the group subjected to placebo LLLT (10.52 mmol l(-1) +/- 1.82 mmol l(-1)). LLLT irradiation before the Wingate test seemed to inhibit an expected post-exercise increase in CK level and to accelerate post-exercise lactate removal without affecting test performance. These findings suggest that LLLT may be of benefit in accelerating post-exercise recovery.

Lasers Med Sci 2008 Dec 5

LED phototherapy to prevent mucositis: a case report.

Lang-Bicudo L, Eduardo Fde P, Eduardoz Cde P, Zezell DM

Mestre Profissional em Lasers em Odontologia IPEN/USP, Universidade de Sao Paulo, Sao Paulo, Brazil.

OBJECTIVE: The purpose of this case report was to evaluate the efficacy of phototherapy using light-emitting diodes (LEDs) to prevent oral mucositis in a Hodgkin’s disease patient treated with the ABVD (doxorubicin [Adriamycin], bleomycin, vinblastine, and dacarbazine) chemotherapy regimen. BACKGROUND DATA: Mucositis is a common dose-limiting complication of cancer treatment, and if severe it can lead to alterations in treatment planning or suspension of cancer therapy, with serious consequences for tumor response and survival. Therefore, low-power lasers and more recently LEDs, have been used for oral mucositis prevention and management, with good results. MATERIALS AND METHODS: In this study, a 34-year-old man received intraoral irradiation with an infrared LED array (880 nm, 3.6 J/cm2, 74 mW) for five consecutive days, starting on chemotherapy day 1. In each chemotherapy cycle, he received the ABVD protocol on days 1 and 15, and received LED treatment for 5 d during each cycle. To analyze the results, the World Health Organization (WHO) scale was used to grade his mucositis, and a visual analogue scale (VAS) was used for pain evaluation, on days 1, 3, 7, 10, and 13 post-chemotherapy. RESULTS: The results showed that the patient did not develop oral mucositis during the five chemotherapy cycles, and he had no pain symptoms. CONCLUSION: LED therapy was a safe and effective method for preventing oral mucositis in this case report. However, further randomized studies with more patients are needed to prove the efficacy of this method.

Photomed Laser Surg 2008 Dec 26(6) 609-13

Carpal tunnel syndrome treated with a diode laser: a controlled treatment of the transverse carpal ligament.

Chang WD, Wu JH, Jiang JA, Yehz CY, Tsai CT

Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei, Taiwan.

OBJECTIVE: The purpose of this placebo-controlled study was to investigate the therapeutic effects of the 830-nm diode laser on carpal tunnel syndrome (CTS). BACKGROUND DATA: Many articles in the literature have demonstrated that low-level laser therapy (LLLT) may help to alleviate various types of nerve pain, especially for CTS treatment. We placed an 830-nm laser directly above the transverse carpal ligament, which is between the pisiform and navicular bones of the tested patients, to determine the therapeutic effect of LLLT. MATERIALS AND METHODS: Thirty-six patients with mild to moderate degree of CTS were randomly divided into two groups. The laser group received laser treatment (10 Hz, 50% duty cycle, 60 mW, 9.7 J/cm(2), at 830 nm), and the placebo group received sham laser treatment. Both groups received treatment for 2 wk consisting of a 10-min laser irradiation session each day, 5 d a week. The therapeutic effects were assessed on symptoms and functional changes, and with nerve conduction studies (NCS), grip strength assessment, and with a visual analogue scale (VAS), soon after treatment and at 2-wk follow-up. RESULTS: Before treatment, there were no significant differences between the two groups for all assessments (p > 0.05). The VAS scores were significantly lower in the laser group than the placebo group after treatment and at follow-up (p < 0.05). After 2 wk of treatment, no significant differences were found in grip strengths or for symptoms and functional assessments (p > 0.05). However, there were statistically significant differences in these variables at 2-wk follow-up (p < 0.05). Regarding the findings of NCS, there was no statistically significant difference between groups after treatment and at 2-wk follow-up. CONCLUSIONS: LLLT was effective in alleviating pain and symptoms, and in improving functional ability and finger and hand strength for mild and moderate CTS patients with no side effects.

Photomed Laser Surg 2008 Dec 26(6) 551-7

810 nm Wavelength light: An effective therapy for transected or contused rat spinal cord.

Wu X, Dmitriev AE, Cardoso MJ, Viers-Costello AG, Borke RC, Streeter J, Anders JJ

Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814.

BACKGROUND AND OBJECTIVES: Light therapy has biomodulatory effects on central and peripheral nervous tissue. Spinal cord injury (SCI) is a severe central nervous system trauma with no effective restorative therapies. The effectiveness of light therapy on SCI caused by different types of trauma was determined. STUDY DESIGN/MATERIALS AND METHODS: Two SCI models were used: a contusion model and a dorsal hemisection model. Light (810 nm) was applied transcutaneously at the lesion site immediately after injury and daily for 14 consecutive days. A laser diode with an output power of 150 mW was used for the treatment. The daily dosage at the surface of the skin overlying the lesion site was 1,589 J/cm(2) (0.3 cm(2) spot area, 2,997 seconds). Mini-ruby was used to label corticospinal tract axons, which were counted and measured from the lesion site distally. Functional recovery was assessed by footprint test for the hemisection model and open-field test for the contusion model. Rats were euthanized 3 weeks after injury. RESULTS: The average length of axonal re-growth in the rats in the light treatment (LT) groups with the hemisection (6.89+/-0.96 mm) and contusion (7.04+/-0.76 mm) injuries was significantly longer than the comparable untreated control groups (3.66+/-0.26 mm, hemisection; 2.89+/-0.84 mm, contusion). The total axon number in the LT groups was significantly higher compared to the untreated groups for both injury models (P<0.05). For the hemisection model, the LT group had a statistically significant lower angle of rotation (P<0.05) compared to the controls. For contusion model, there was a statistically significant functional recovery (P<0.05) in the LT group compared to untreated control. CONCLUSIONS: Light therapy applied non-invasively promotes axonal regeneration and functional recovery in acute SCI caused by different types of trauma. These results suggest that light is a promising therapy for human SCI. Lasers Surg. Med. 41:36-41, 2009. (c) 2008 Wiley-Liss, Inc.

Lasers Surg Med 2009 Jan 13 41(1) 36-41

Low-level laser therapy improves bone repair in rats treated with anti-inflammatory drugs.

Ribeiro DA, Matsumoto MA

Department of Biosciences, Federal University of Sao Paulo, UNIFESP, Santos, SP, Brazil.

Nowadays, selective cyclooxygenase-2 non-steroidal anti-inflammatory drugs have been largely used in surgical practice for reducing oedema and pain. However, the association between these drugs and laser therapy is not known up to now. Herein, the aim of this study was to evaluate the action of anti-COX-2 selective drug (celecoxib) on bone repair associated with laser therapy. A total of 64 rats underwent surgical bone defects in their tibias, being randomly distributed into four groups: Group 1) negative control; Group 2) animals treated with celecoxib; Group 3) animals treated with low-level power laser and Group 4) animals treated with celecoxib and low-level power laser. The animals were killed after 48 h, 7, 14 and 21 days. The tibias were removed for morphological, morphometric and immunohistochemistry analysis for COX-2. Statistical significant differences (P < 0.05) were observed in the quality of bone repair and quantity of formed bone between groups at 14 days after surgery for Groups 3 and 4. COX-2 immunoreactivity was more intense in bone cells for intermediate periods evaluated in the laser-exposed groups. Taken together, such results suggest that low-level laser therapy is able to improve bone repair in the tibia of rats as a result of an up-regulation for cyclooxygenase-2 expression in bone cells.

J Oral Rehabil 2008 Dec 35(12) 925-33

Low-level laser efficiency in the therapy of chronic gingivitis in children

Igic M, Kesic L, Apostolovic M, Kostadinovic L

Medicinski fakultet, Klinika za stomatologiju, Nis, Srbija.

BACKGROUND/AIM: Gingivitis is a frequent phenomenon in children considered to be a risk factor for the occurrence and progression of paradontal tissue disease. So, it is necessary not only to identify inflammation, but also to react in due time and adequately in order to avoid further disease spread and the beginning of periodontitis. The aim of this study was to determine the efficiency of a low-level laser application in the therapy of chronic gingivitis in children. METHODS: The study a included hundred of children with permanent dentition suffering from chronic gingivitis. All the examinees were divided into two groups: group I–50 examinees with chronic gingivitis, who underwent the basic therapy; group II–50 examinees with chronic gingivitis, who underwent the basic therapy and also a therapy with a low-level laser. Evaluation of the condition of oral hygiene, the health of gingiva and periodontium were done using appropriate index before and after the therapy. RESULTS: For the plaque index (PI) following results were obtained: in the group I PI = 1.94, and in the group II PI = 1.82. After the therapy in both groups PI was 0. In the group I sulcus plaque index (SPI) was 2.02 before the therapy and 0.32 after the therapy. In the group II SPI was 1.90 before the therapy, and 0.08 after the therapy. In the group I Community Periodontal Index of Treatment Needs (CPITN) was 1.66 before the therapy, and 0.32 after the therapy, and in the group II CPITN was 1.60 before the therapy, and 0.08 after the therapy. CONCLUSION: Chronic gingivitis in children can be successfully cured by the basic treatment. The use of a low-level laser can significantly improve this effect.

Vojnosanit Pregl 2008 Oct 65(10) 755-7

Low level laser therapy (LLLT): Attenuation of cholinergic hyperreactivity, beta(2)-adrenergic hyporesponsiveness and TNF-alpha mRNA expression in rat bronchi segments in E. coli lipopolysaccharide-induced airway inflammation by a NF-kappaB dependent mechanism.

Mafra de Lima F, Costa MS, Albertini R, Silva JA Jr, Aimbire F

Institute of Research and Development (IP&D), Av. Shishima Hifumi, 2911, Urbanova, Sao Jose dos Campos, Sao Paulo 12244-000, Brazil.

BACKGROUND AND OBJECTIVES: It is unknown if the decreased ability to relax airways smooth muscles in asthma and other inflammatory disorders, such as acute respiratory distress syndrome (ARDS), can be influenced by low level laser therapy (LLLT) irradiation. In this context, the present work was developed in order to investigate if LLLT could reduce dysfunction in inflamed bronchi smooth muscles (BSM) in rats. STUDY DESIGN/MATERIALS AND METHODS: A controlled ex vivo study was developed where bronchi from Wistar rat were dissected and mounted in an organ bath apparatus with or without a TNF-alpha. RESULTS: LLLT administered perpendicularly to a point in the middle of the dissected bronchi with a wavelength of 655 nm and a dose of 2.6 J/cm(2), partially decreased BSM hyperreactivity to cholinergic agonist, restored BSM relaxation to isoproterenol and reduced the TNF-alpha mRNA expression. An NF-kappaB antagonist (BMS205820) blocked the LLLT effect on dysfunction in inflamed BSM. CONCLUSION: The results obtained in this work indicate that the LLLT effect on alterations in responsiveness of airway smooth muscles observed in TNF-alpha-induced experimental acute lung inflammation seems to be dependent of NF-kappaB activation. Lasers Surg. Med. 41:68-74, 2009. (c) 2008 Wiley-Liss, Inc.

Lasers Surg Med 2009 Jan 13 41(1) 68-74

Light therapy and supplementary riboflavin in the SOD1 transgenic mouse model of familial amyotrophic lateral sclerosis (FALS).

Moges H, Vasconcelos OM, Campbell WW, Borke RC, McCoy JA, Kaczmarczyk L, Feng J, Anders JJ

Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814.

BACKGROUND AND OBJECTIVE: Familial amyotrophic lateral sclerosis (FALS) is a neurodegenerative disease characterized by progressive loss of motor neurons and death. Mitochondrial dysfunction and oxidative stress play an important role in motor neuron loss in ALS. Light therapy (LT) has biomodulatory effects on mitochondria. Riboflavin improves energy efficiency in mitochondria and reduces oxidative injury. The purpose of this study was to examine the synergistic effect of LT and riboflavin on the survival of motor neurons in a mouse model of FALS. STUDY DESIGN/MATERIALS AND METHODS: G93A SOD1 transgenic mice were divided into four groups: Control, Riboflavin, Light, and Riboflavin+Light (combination). Mice were treated from 51 days of age until death. A single set of LT parameters was used: 810 nm diode laser, 140-mW output power, 1.4 cm(2) spot area, 120 seconds treatment duration, and 12 J/cm(2) energy density. Behavioral tests and weight monitoring were done weekly. At end stage of the disease, mice were euthanized, survival data was collected and immunohistochemistry and motor neuron counts were performed. RESULTS: There was no difference in survival between groups. Motor function was not significantly improved with the exception of the rotarod test which showed significant improvement in the Light group in the early stage of the disease. Immunohistochemical expression of the astrocyte marker, glial fibrilary acidic protein, was significantly reduced in the cervical and lumbar enlargements of the spinal cord as a result of LT. There was no difference in the number of motor neurons in the anterior horn of the lumbar enlargement between groups. CONCLUSIONS: The lack of significant improvement in survival and motor performance indicates study interventions were ineffective in altering disease progression in the G93A SOD1 mice. Our findings have potential implications for the conceptual use of light to treat other neurodegenerative diseases that have been linked to mitochondrial dysfunction. Lasers Surg. Med. 41:52-59, 2009. (c) 2008 Wiley-Liss, Inc.

Lasers Surg Med 2009 Jan 13 41(1) 52-59

Low-power laser irradiation promotes cell proliferation by activating PI3K/Akt pathway.

Zhang L, Xing D, Gao X, Wu S

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

Low-power laser irradiation (LPLI) can stimulate cell proliferation through a wide network of signals. Akt is an important protein kinase in modulating cell proliferation. In this study, using real-time single-cell analysis, we investigated the activity of Akt and its effects on cell proliferation induced by LPLI in African green monkey SV40-transformed kidney fibroblast cells (COS-7). We utilized a recombinant fluorescence resonance energy transfer (FRET) Akt probe (BKAR) to dynamically detect the activation of Akt after LPLI treatment. Our results show that LPLI induced a gradual and continuous activation of Akt. Moreover, the activation of Akt can be completely abolished by wortmannin, a specific inhibitor of PI3K, suggesting that the activation of Akt caused by LPLI is a PI3K-dependent event. Src family is involved in Akt activation as demonstrated by the part inhibition of Akt activity in samples treated with PP1 (an inhibitor of Src family). In contrast, loading Go 6983, a PKC inhibitor, did not affect this response. Further experiments performed using GFP-Akt fluorescence imaging and Western blot analysis demonstrate that, the activation of Akt is a multi-step process in response to LPLI, involving membrane recruitment, phosphorylation, and membrane detachment. LPLI promotes cell proliferation through PI3K/Akt activation since the cell viability was significantly inhibited by PI3K inhibitor. All these studies create a concernful conclusion that PI3K/Akt signaling pathway is well involved in LPLI triggered cell proliferation that acts as a time- and dose-dependent manner. J. Cell. Physiol. (c) 2009 Wiley-Liss, Inc.

J Cell Physiol 2009 Jan 13

H-Ras and PI3K are required for the formation of circular dorsal ruffles induced by low-power laser irradiation.

Gao X, Xing D, Liu L, Tang Y

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

The formation of circular dorsal ruffles upon growth factor stimulation facilitates the static cells for subsequent motility. Low-power laser irradiation (LPLI) has been shown to exert some promotive effects on migration and proliferation in various cell types. It is unclear whether LPLI could induce the formation of circular ruffles. In this study, using confocal fluorescence microscope, we for the first time demonstrated that LPLI could induce the production of circular ruffle structures in COS-7 cells. These structures were proved to be actin-based and originated from membrane microdomains enriched in cholesterol. Ras was shown to be activated by LPLI and expression of YFP-H-Ras (N17), a dominant negative H-Ras, blocked the generation of circular ruffles induced by LPLI. Wortmannin, PI3K inhibitor, potently suppressed the formation of LPLI-induced circular ruffles in a dose-dependent manner. However, blocking the activation of PKC, which was activated during LPLI-induced cell proliferation in our previous study, had no effect on the formation of circular ruffles. Thus, both H-Ras and PI3K were required for the formation of circular ruffles induced by LPLI and the generation of circular ruffles provides new information for the mechanisms of biological effects of LPLI. J. Cell. Physiol. (c) 2009 Wiley-Liss, Inc.

J Cell Physiol 2009 Jan 13

Effects of linear polarized infrared light irradiation on the transcriptional regulation of IL-8 expression in IL-1beta-stimulated human rheumatoid synoviocytes involves phosphorylation of the NF-kappaB RelA subunit.

Shibata Y, Araki H, Oshitani T, Imaoka A, Matsui M, Miyazawa K, Abiko Y

Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, 2-870-1, Sakaecho-Nishi, Matsudo, Chiba 271-8587, Japan.

Although recent clinical studies have shown that laser therapy acts as an anti-inflammatory effector in the treatment of some diseases, little is known about the mechanism by which it acts in rheumatoid arthritis (RA) patients. The purpose of our work was to examine how irradiation with linear polarized infrared light (LPIL) suppresses inflammatory responses in the MH7A rheumatoid fibroblast-like synoviocyte cell line. We initially confirmed the effects of two disease-modifying anti-rheumatic treatments, LPIL irradiation and dexamethasone (Dex) administration, under experimental inflammatory conditions using gene chip technology. We found that LPIL exerted a smaller effect on gene transcription than Dex; however, IL-1beta-inducible target genes such as the CXCL type chemokines IL-8, IL-1beta and IL-6 were all clearly suppressed by LPIL to the same degree as by Dex. We also found that IL-1beta-induced release of IL-8 from MH7A cells was completely blocked by pretreatment with the (IL-8) inhibitor Bay11-7085, indicating that activation of NF-kappaB signaling plays an important role in the secretion of IL-8. Although the levels of NFKB1 and RELA transcription were unaffected by IL-1beta stimulation, phosphorylation of RelA S276 was suppressed by both LPIL and Dex. Thus LPIL likely exerts its anti-inflammatory effects by inhibiting the release of the inflammatory chemokine IL-8. A fuller understanding of the anti-inflammatory mechanism of LPIL in rheumatoid synoviocytes could serve as the basis for improved treatment of RA patients in the future.

J Photochem Photobiol B 2008 Dec 7

Effect of laser therapy (660 nm) on recovery of the sciatic nerve in rats after injury through neurotmesis followed by epineural anastomosis.

Dos Reis FA, Belchior AC, de Carvalho PD, da Silva BA, Pereira DM, Silva IS, Nicolau RA

Universidade para o Desenvolvimento do Estado e da Regiao do Pantanal (UNIDERP), Campo Grande, Mato Grosso do Sul, Brazil,

The aim of this study was to analyze the influence of aluminum gallium arsenide (AlGaAs) laser (660 nm) on the myelin sheath and functional recovery of the sciatic nerve in rats. The sciatic nerves of 12 Wistar rats were subjected to injury through neurotmesis and epineural anastomosis, and the animals were divided into two groups: group 1 was the control and group 2, underwent low-level laser therapy (LLLT). After the injury, AlGaAs laser at 660 nm, 4 J/cm(2), 26.3 mW and beam area of 0.63 cm(2) was administered to three equidistant points on the injury for 20 consecutive days. In the control group the mean area of the myelin impairment was 0.51 (+/- 0.11) on day 21 after the operation, whereas this value was 1.31 (+/- 0.22) in the LLLT group. Student’s t-test revealed a P value = 0.0229 for the mean area values of the myelin sheath between the LLLT and control groups. Comparison of the sciatic functional index (SFI) showed that there was no significant difference between the pre-lesion value in the laser therapy group and the control group. The use of AlGaAs laser (660 nm) provided significant changes to the morphometrically assessed area of the myelin sheath, but it did not culminate in positive results for functional recovery in the sciatic nerve of the rats after injury through neurotmesis.

Lasers Med Sci 2008 Dec 23

DNA damage after phototherapy in wounded fibroblast cells irradiated with 16J/cm(2).

Mbene AB, Houreld NN, Abrahamse H

Laser Research Group, Faculty of Health Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein, Johannesburg 2028, South Africa.

BACKGROUND AND OBJECTIVE: Phototherapy or biomodulation is a remarkable therapy that has become more popular and widely used in the treatment of a variety of medical conditions, such as slow to heal wounds, pain, soft tissue injuries and skin trauma. It has been shown to induce DNA damage; however this damage appears to be repairable. This study aimed to determine the effects of phototherapy induced DNA damage and activation of the DNA repair gene methylpurine DNA glycosylase (MPG). MATERIALS AND METHODS: DNA integrity was assessed using the comet assay, with and without formamidopyrimidine glycosylase (Fpg). For the comet assay, wounded human skin fibroblast cells (WS1) were irradiated twice, once at 30min and again at 72h with 5 or 16J/cm(2) using a diode laser at 636nm and cellular responses were assessed 1 or 24h post-irradiation. Real time reverse transcriptase polymerase chain reaction (RT-PCR) assessed MPG expression and three reference genes namely; beta Actin (ACTB), Glyceraldehyde three phosphate dehydrogenase (GAPDH) and Ubiquitin c (UBC). Wounded cells were irradiated once (30min) with 16J/cm(2), and MPG expression was assessed at 0, 3 and 8h post-laser irradiation. RESULTS: At both 1 and 24h, wounded cells irradiated with 5J/cm(2) showed insignificant DNA damage compared to control cells, while irradiation with 16J/cm(2) showed significant damage. However, 24h post-irradiation these cells showed a significant decrease in damage compared to cells left to incubate for 1h. This observation was attributed to activation of DNA repair mechanisms. Real time RT-PCR showed that ACTB was not influenced by cell culture conditions or laser irradiation, and MPG expression was not detected. CONCLUSION: In conclusion, irradiation with 5J/cm(2) did not produce additional DNA damage, while damage to cells irradiated with 16J/cm(2) was repairable by mechanisms other than MPG. This study also showed that ACTB can be used as a reference gene in laser experiments, using parameters set out in this study.

J Photochem Photobiol B 2008 Nov 21

Absorption measurements of cell monolayers relevant to mechanisms of laser phototherapy: reduction or oxidation of cytochrome c oxidase under laser radiation at 632.8 nm.

Karu TI, Pyatibrat LV, Kolyakov SF, Afanasyeva NI

Institute of Laser and Information Technologies of Russian Academy of Sciences, Troitsk, Moscow Region 142190, Russian Federation.

OBJECTIVE: The objective of this work was a further investigation of redox mechanisms of laser phototherapy on the cellular level. BACKGROUND DATA: Cytochrome c oxidase, the terminal enzyme of the mitochondrial respiratory chain, is believed to work as the photoacceptor to modulate cellular metabolism in laser phototherapy. MATERIALS AND METHODS: The changes in the absorption spectra of HeLa-cell monolayers before and after irradiation at 632.8 nm using fast multi-channel recording were evaluated by the intensity ratio between the peaks at 770 and 670 nm (intensity ratio criterion). RESULTS: By the intensity ratio criterion, the irradiation effects (reduction or oxidation of the photoacceptor) depended on the initial redox status of cytochrome c oxidase. The irradiation (three times at 632.8 nm, dose = 6.3 x 103 J/m(2), tau(irrad.) = 10 sec, tau(record.) = 600 msec) of cells initially characterized by relatively oxidized cytochrome c oxidase caused first a reduction of the photoacceptor, and then its oxidation (a bell-shaped curve). The irradiation by the same scheme of the cells with initially relatively reduced cytochrome c oxidase caused first oxidation and then a slight reduction of the enzyme (a curve opposite to the bell-shaped curve). CONCLUSION: The experimental results of our work demonstrate that irradiation at 632.8 nm causes either a (transient) relative reduction of the photoacceptor, putatively cytochrome c oxidase, or its (transient) relative oxidation, depending on the initial redox status of the photoacceptor. The maximum in the bell-shaped dose-dependence curve or the minimum of the reverse curve is the turning point between the prevailing of oxidation or reduction processes. Our results are evidence that the bell-shaped dose dependences recorded for various cellular responses are characteristic also for redox changes in the photoacceptor, cytochrome c oxidase.

Photomed Laser Surg 2008 Dec 26(6) 593-9

IEX-1 targets mitochondrial F1Fo-ATPase inhibitor for degradation.

Shen L, Zhi L, Hu W, Wu MX

1Wellman Center of Photomedicine, Massachusetts General Hospital, and Department of Dermatology, Harvard Medical School, Boston, MA 02114, USA.

IEX-1 (Immediate Early response gene X-1) is a stress-inducible gene. It suppresses production of reactive oxygen species (ROS) and protects cells from apoptosis induced by a wide range of stimuli, but the underlying mechanism is not known. This study reveals that IEX-1 targets the mitochondrial F1Fo-ATPase Inhibitor (IF1) for degradation, resulting in acceleration of ATP hydrolysis, concomitant with reduction in ROS production. A prominent role for IF1 degradation in the function of IEX-1 was corroborated by siRNA-mediated gene silencing of IF1 that recapitulated the effects of IEX-1 on ATP hydrolysis and ROS production. Moreover, progressive C-terminal truncation studies demonstrated that IEX-1 interacted with the C terminus of IF1 and the interaction might render IF1 prone to degradation by an as yet unidentified mitochondrial protease. In support of a physiological importance of IEX-1 in the modulation of IF1 expression, gene-targeted deletion of IEX-1 stabilized IF1 and reduced mitochondrial F1Fo-ATPase activity in vivo. The altered activity of the F1Fo enzyme may account for a metabolic switch from oxidative phosphorylation toward glycolysis in IEX-1 deficient cells. Thus, IEX-1 deficient cells were more susceptible to glucose deprivation than wild type counterparts and displayed increased glucose uptake and lactate production in hypoxic conditions. The cells were also relatively refractory to oligomycin-mediated inhibition of ATP production. The studies offer novel insights into the primary role of IEX-1 in regulating a balance between energy provision and ROS production.Cell Death and Differentiation advance online publication, 19 December 2008; doi:10.1038/cdd.2008.184.

Cell Death Differ 2008 Dec 19

The histological and clinical effects of 630 nanometer and 860 nanometer low-level laser on rabbits’ ear punch holes.

Kamrava SK, Farhadi M, Rezvan F, Sharifi D, Ashrafihellan J, Shoaee S, Rezvan B

ENT, Head & Neck Surgery Research Center, Iran University of Medical Sciences, Tehran, Iran.

Low-level laser therapy (LLLT) studies on the musculoskeletal and cartilage tissues of rabbits have reported conflicting results. We aimed to investigate the effects of 630 nm and 860 nm low-level laser on injured rabbit cartilage. After punching 5 mm holes in both ears of ten rabbits, we grouped the rabbits randomly. The punched holes of the laser-treated group were irradiated with 630 nm and 860 nm diode laser on days 3-5 and then every other day until day 20. In both laser and control groups, the hole diameters were measured weekly. Histological evaluation was carried out on day 30. The inter-group difference in hole diameters was not significant. Mann-Whitney U tests showed significant inter-group differences in histological variables related to chondrocyte production and organization, growth rate, granulation tissue and pseudocarcinomatosis. LLLT improved cartilage formation and reduced inflammation and formation of granulation tissue. More accurate results on its healing effects warrant studies with larger sample sizes.

Lasers Med Sci 2008 Dec 3

Enhancement of light propagation depth in skin: cross-validation of mathematical modeling methods.

Kwon K, Son T, Lee KJ, Jung B

Department of Biomedical Engineering, Yonsei University, 234 Maeji-Ri, Heungup-Myeon, Wonju-Si, Gangwon-Do, 220-710, Korea.

Various techniques to enhance light propagation in skin have been studied in low-level laser therapy. In this study, three mathematical modeling methods for five selected techniques were implemented so that we could understand the mechanisms that enhance light propagation in skin. The five techniques included the increasing of the power and diameter of a laser beam, the application of a hyperosmotic chemical agent (HCA), and the whole and partial compression of the skin surface. The photon density profile of the five techniques was solved with three mathematical modeling methods: the finite element method (FEM), the Monte Carlo method (MCM), and the analytic solution method (ASM). We cross-validated the three mathematical modeling results by comparing photon density profiles and analyzing modeling error. The mathematical modeling results verified that the penetration depth of light can be enhanced if incident beam power and diameter, amount of HCA, or whole and partial skin compression is increased. In this study, light with wavelengths of 377 nm, 577 nm, and 633 nm was used.

Lasers Med Sci 2008 Nov 22

Effect of Application Site of Low-Level Laser Therapy in Random Cutaneous Flap Viability in Rats.

Prado RP, Pinfildi CE, Liebano RE, Hochman BS, Ferreira LM

Master of Basic Sciences in Plastic Surgery, Sao Paulo Federal University, Sao Paulo, Brazil.

Abstract Objective: This study aimed to investigate the effect of diode laser (830 nm) irradiation on the viability of ischemic random skin flaps in rats, as well as to determine the most effective site for applying laser radiation to speed healing. Background Data: Low-level laser therapy (LLLT) has recently been used to improve the viability of ischemic random skin flaps in rats. Materials and Methods: Seventy Wistar rats were used and divided into seven groups of 10 rats each: group 1, sham laser treatment; group 2, which received irradiation at 1 point 5 cm from the flap’s cranial base; group 3, which received irradiation at 2 points (5 and 7.5 cm from the flap’s base); group 4, which received irradiation at 3 points (2.5, 5 and 7.5 cm from the flap’s base); group 5, which received irradiation at 1 point 2.5 cm from the flap’s base; group 6, which received irradiation at 2 points (2.5 and 5 cm from the flap’s base); and group 7, which received irradiation at 1 point 7.5 cm from the flap’s base. The animals were subjected to laser therapy at an energy density of 36 J/cm(2) for 72 sec immediately after surgery, and one time on each of the four subsequent days. The percentage of necrotic skin flap area was calculated on the seventh postoperative day using a paper template. Results: The results showed that the rats in group 5 had the highest increase in skin flap viability, with a statistically significant difference compared to the other groups. Statistically significant differences were not seen between any of the other groups. Conclusion: The diode laser was effective in increasing skin flap viability in rats, and laser irradiation of a point 2.5 cm from the cranial base flap was found to be the most effective.

Photomed Laser Surg 2008 Nov 23

Effect of low-level laser therapy after implantation of poly-L: -lactic/polyglycolic acid in the femurs of rats.

Freddo AL, Rodrigo SM, Massotti FP, Etges A, de Oliveira MG

School of Dentistry, Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, Rio Grande do Sul, Brazil.

This study evaluated the use of red and infrared lasers on tissue surrounding the femurs of 60 rats randomly divided into three groups after implantation of bioabsorbable plates. The control group were not subjected to laser irradiation; group A was treated with red laser [indium-gallium-aluminum-phosphide (InGaAlP) laser, wavelength 685 nm, 35 mW, continuous wave (CW), O = 0.06 cm, 2.23 min], and group B was subjected to infrared laser [gallium-aluminum-arsenium (GaAlAs) laser, wavelength 830 nm, 50 mw, CW, O = 0.06 cm, 1.41 min], both at 10 J/cm(2). Samples were stained with hematoxylin and eosin (H&E) and examined microscopically. Results showed that the laser irradiation had had a positive photobiomodulation effect on inflammation, confirmed by a better histologic pattern than that of the control group at 3 days and 7 days. Semiquantitative analysis revealed that groups A and B had a histologic score significantly greater than that of the control group at 3 days. At 21 days, histomorphometric analysis revealed a more intense inflammation in the red laser group than in the other groups. We concluded that low-level laser therapy (LLLT) has positive effects on the photobiomodulation of inflammation in the tissues surrounding the poly-L: -lactic/polyglycolic acid (PLLA/PGA) bioabsorbable plate. It stimulated vascularization, fibroblast proliferation, and collagen deposition.

Lasers Med Sci 2008 Nov 15

About James Carroll

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