Effect of low-level laser irradiation on in vitro function of pancreatic islets.

INTRODUCTION: Although islet isolation and transplantation techniques have improved extensively in recent years, the loss of healthy functional islets is one of the major obstacles in this enterprise. A biostimulatory effect of low-level laser irradiation has been proven on proliferation of some kinds of cells. The aim of this study was to evaluate the effect of low-level laser irradiation on the function of isolated rat pancreatic islets after 24 hours of preculture. METHODS: Pancreatic islets isolated from male rats (250 to 300 g) were cultured for 24 hours in RPMI 1640 media. Groups of islets then received different energy densities (1, 3, 5 joules/cm(2) or silent) at 2 wavelengths (810 nm and 630 nm) using laser devices. Insulin concentrations in buffer media were measured as indices of islet function. RESULTS: Irradiation of incubated islets with 830 nm low-level laser significantly increased insulin secretion after a glucose challenge test (P < .05). There was a significant increase in insulin secretion after irradiation with joules/cm(2) 630 nm energy density (P < .001). CONCLUSION: These findings suggest that low-level laser irradiations improved islet cell function before transplantation.

Low level laser therapy for nonspecific low-back pain.

BACKGROUND: Low-back pain (LBP) is a major health problem and a major cause of medical expenses and disablement. Low level laser therapy (LLLT) can be used to treat musculoskeletal disorders such as back pain. OBJECTIVES: To assess the effects of LLLT in patients with non-specific LBP. SEARCH STRATEGY: We searched CENTRAL (The Cochrane Library 2005, Issue 2), MEDLINE, CINAHL, EMBASE, AMED and PEDro from their start to November 2007 with no language restrictions. We screened references in the included studies and in reviews and conducted citation tracking of identified RCTs and reviews using Science Citation Index. We also contacted content experts. SELECTION CRITERIA: Randomised controlled clinical trials (RCTs) investigating LLLT to treat non-specific low-back pain were included. DATA COLLECTION AND ANALYSIS: Two authors independently assessed methodological quality using the criteria recommended by the Cochrane Back Review Group and extracted data. Studies were qualitatively and quantitatively analysed according to Cochrane Back Review Group guideline. MAIN RESULTS: Seven heterogeneous English language RCTs with reasonable quality were included. Three small studies (168 people) separately showed statistically significant but clinically unimportant pain relief for LLLT versus sham therapy for sub-acute and chronic low-back pain at short-term and intermediate-term follow-up (up to six months). One study (56 people) showed that LLLT was more effective than sham at reducing disability in the short term. Three studies (102 people) reported that LLLT plus exercise were not better than exercise, with or without sham in the short-term in reducing pain or disability. Two studies (90 people) reported that LLLT was not more effective than exercise, with or without sham in reducing pain or disability in the short term. Two small trials (151 people) independently found that the relapse rate in the LLLT group was significantly lower than in the control group at the six-month follow-up. No side effects were reported. AUTHORS' CONCLUSIONS: Based on the heterogeneity of the populations, interventions and comparison groups, we conclude that there are insufficient data to draw firm conclusions on the clinical effect of LLLT for low-back pain. There is a need for further methodologically rigorous RCTs to evaluate the effects of LLLT compared to other treatments, different lengths of treatment, wavelengths and dosages.

WITHDRAWN: Low level laser therapy for nonspecific low-back pain.

BACKGROUND: Low-back pain (LBP) and related disabilities are major public health problems and a major cause of medical expenses, absenteeism and disablement. Low level laser therapy (LLLT) can be used as a therapeutic intervention for musculoskeletal disorders such as back pain. OBJECTIVES: To assess the effects of LLLT in patients with non-specific low-back pain and to explore the most effective method of administering LLLT for this disorder. SEARCH STRATEGY: We searched CENTRAL (The Cochrane Library 2005, Issue 2), MEDLINE and CINAHL from their start to January 2007 and EMBASE, AMED and PEDro from their start to 2005 with no language restrictions. We screened references in the included studies and in reviews of the literature and conducted citation tracking of identified RCTs and reviews using Science Citation Index. We also contacted content experts. SELECTION CRITERIA: Only randomised controlled clinical trials (RCTs) investigating low level laser therapy as a light source treatment for non-specific low-back pain were included. DATA COLLECTION AND ANALYSIS: Two authors independently assessed methodological quality using the criteria recommended by the Cochrane Back Review Group and extracted data. Consensus was used to resolve disagreements. Clinically and statistically homogeneous studies were pooled using the fixed-effect model; clinically homogeneous and statistically heterogeneous studies were pooled using the random-effects model. MAIN RESULTS: Six RCTs with reasonable quality were included in the review. All of them were published in English. Because of clinical heterogeneity in study populations, interventions used and reported outcomes, meta-analysis was not possible to determine an overall effect for pain, disability and range of motion. Three studies (n=168) separately showed a significant pain relief effect of LLLT compared to sham therapy for sub-acute and chronic low-back pain. These effects were only observed at short-term and intermediate-term follow-ups. Long-term follow-ups were not reported. There was insufficient evidence to investigate the difference between LLLT and comparison groups for pain-related disability. There is insufficient evidence to determine the effectiveness of LLLT on anterior-posterior lumbar range of motion compared to control group in short-term follow-up. The relapse rate in the LLLT group was significantly lower than in the control group at six months follow-up period according to the findings of two trials. One study (n=50) reported a significant improvement in pain in LLLT group versus exercise therapy. AUTHORS' CONCLUSIONS: No side effects were reported. However, we conclude that there are insufficient data to draw firm conclusions. There is a need for further methodologically rigorous RCTs to evaluate the effects of LLLT compared to other treatments, different lengths of treatment, different wavelengths and different dosages. Comparison of different LLLT treatments will be more reasonable if dose calculation methods are harmonized.

Low level laser therapy for nonspecific low-back pain.

BACKGROUND: Low-back pain (LBP) and related disabilities are major public health problems and a major cause of medical expenses, absenteeism and disablement. Low level laser therapy (LLLT) can be used as a therapeutic intervention for musculoskeletal disorders such as back pain. OBJECTIVES: To assess the effects of LLLT in patients with non-specific low-back pain and to explore the most effective method of administering LLLT for this disorder. SEARCH STRATEGY: We searched CENTRAL (The Cochrane Library 2005, Issue 2), MEDLINE and CINAHL from their start to January 2007 and EMBASE, AMED and PEDro from their start to 2005 with no language restrictions. We screened references in the included studies and in reviews of the literature and conducted citation tracking of identified RCTs and reviews using Science Citation Index. We also contacted content experts. SELECTION CRITERIA: Only randomised controlled clinical trials (RCTs) investigating low level laser therapy as a light source treatment for non-specific low-back pain were included. DATA COLLECTION AND ANALYSIS: Two authors independently assessed methodological quality using the criteria recommended by the Cochrane Back Review Group and extracted data. Consensus was used to resolve disagreements. Clinically and statistically homogeneous studies were pooled using the fixed-effect model; clinically homogeneous and statistically heterogeneous studies were pooled using the random-effects model. MAIN RESULTS: Six RCTs with reasonable quality were included in the review. All of them were published in English. There is some evidence of pain relief with LLLT, compared to sham therapy for subacute and chronic low-back pain. These effects were only observed at short-term and intermediate-term follow-ups. Long-term follow-ups were not reported. There was no difference between LLLT and comparison groups for pain-related disability. There is insufficient evidence to determine the effectiveness of LLLT on antero-posterior lumbar range of motion compared to control group in short-term follow-up. The relapse rate in the LLLT group was significantly lower than in the control group at six months follow-up period according to the findings of two trials. AUTHORS' CONCLUSIONS: No side effects were reported. However, we conclude that there are insufficient data to draw firm conclusions. There is a need for further methodologically rigorous RCTs to evaluate the effects of LLLT compared to other treatments, different lengths of treatment, different wavelengths and different dosages. Comparison of different LLLT treatments will be more reasonable if dose calculation methods are harmonized.