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PubMed2000

Low level laser therapy (classes I, II and III) for the treatment of osteoarthritis.

BACKGROUND: Osteoarthritis (OA) affects a large proportion of the population. Low Level Laser Therapy (LLLT) is a light source that generates extremely pure light, of a single wavelength. The effect is not thermal, but rather related to photochemical reactions in the cells. LLLT was introduced as an alternative non-invasive treatment for OA about 10 years ago, but its effectiveness is still controversial. OBJECTIVES: To assess the effectiveness of LLLT in the treatment of OA. SEARCH STRATEGY: We searched MEDLINE, EMBASE, the Cochrane Musculoskeletal registry, the registry of the Rehabilitation and Related Thereapies field and the Cochrane Controlled Trials Register up to January 30, 2000. SELECTION CRITERIA: Following an a priori protocol, only controlled clinical trials of LLLT for the treatment of patients with a clinical diagnosis of OA were eligible. Abstracts were excluded unless further data could be obtained from the authors. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected trials and abstracted data using predetermined forms. Heterogeneity was tested with Cochran's Q test. A fixed effects model was used throughout for continuous variables, except where heterogeneity existed, in which case, a random effects model was used. Results were analyzed as weighted mean differences (WMD) with 95% confidence intervals (CI), where the difference between the treated and control groups was weighted by the inverse of the variance. Standardized mean differences (SMD) were calculated by dividing the difference between treated and control by the baseline variance. SMD were used when different scales were used to measure the same concept (e.g. pain). Dichotomous outcomes were analyzed with odds ratios. MAIN RESULTS: Five trials were included, with 112 patients randomized to laser, 85 patients to placebo laser. Treatment duration ranged from 4 to 10 weeks. Pain was assessed by four trials. The pooled estimate (random effects) of three trials showed no effect on pain measured using a scale (SMD: -0.2, 95% CI: -1.0, +0.6), but there was statistically significant heterogeneity (p>0,05). Two of the trials showed no effect and one demonstrated very beneficial effects with laser. In another trial, with no scale-based pain outcome, significantly more patients reported pain relief (yes/no) with laser with an odds ratio of 0.05, (95% CI: 0.0 to 1.56). Other outcomes of joint tenderness, joint mobility and strength were not significant. REVIEWER'S CONCLUSIONS: For OA, the results are conflicting in different studies and may depend on the method of application and other features of the LLLT application. Clinicians and researchers should consistently report the characteristics of the LLLT device and the application techniques used. New trials on LLLT should make use of standardized, validated outcomes. Despite some positive findings, this meta-analysis lacked data on how LLLT effectiveness is affected by four important factors: wavelength, treatment duration of LLLT, dosage and site of application over nerves instead of joints. There is clearly a need to investigate the effects of these factors on LLLT effectiveness for OA in randomized controlled clinical trials.

Humans↗
PubMed2006

The effect of HLA class I (A and B) and class II (DR) compatibility on liver transplantation outcomes: an analysis of the OPTN database.

The purpose of this study was to explore the relationship between human leukocyte antigen (HLA) compatibility and liver transplantation outcomes by analyzing the effect of HLA compatibility on 5-year graft survival. We analyzed first liver transplants between 1987 and 2002 in the Organ Procurement and Transplantation Network (OPTN) database, where A, B, or DR loci data were available. Graft failure was defined as retransplantation or death from transplant-related cause. We evaluated associations between total and locus-specific match levels and 5-year graft survival. Multivariable Cox proportional-hazard models were used to evaluate statistical interactions and adjust for the effect of potential confounders. Among 29,675 first-time transplants, the overall degree of HLA match had no effect on 5-year graft survival, even after controlling for potential confounders. Univariate and multivariable analyses showed that the 0 HLA antigen mismatch cohort of patients had higher 5-year graft failure rates than the other 6 antigen mismatch groups. However, this occurred in a small group with a disproportionately large number of live donors and split-liver recipients. When these recipients were excluded from the analysis, the effect was no longer seen. Finally, multivariable, locus-specific analyses showed no association between 5-year graft survival and degree of match/mismatch and the A, B, or DR loci. In conclusion, this careful examination of the OPTN database, with respect to HLA match or mismatch and liver graft survival, reaffirms that HLA matching has no clinically significant impact on this outcome.

Cohort Studies↗
PubMed2002

Different functions of the class I and class II chitin synthase genes, chsC and chsA, are revealed by repression of chsB expression in Aspergillus nidulans.

The filamentous fungus, Aspergillus nidulans, genome contains at least five chitin synthase-encoding genes. chsB is essential for normal hyphal growth. chsA and chsC are likely to be cooperatively required for hyphal wall integrity. In this study, we constructed chsA chsB and chsC chsB double mutants, in which chsB expression was under a repressible promoter [ alcA(p)]. While chsA or chsC single mutants did not show obvious growth defects, the chsA chsB and chsC chsB double mutants showed different phenotypes from the chsB single mutant and from each other under alcA(p)-repressing conditions. The chsA chsB double mutant produced fewer aerial hyphae and the chsC chsB double mutant showed reduced cell mass. These observations support the idea that chsA and chsC each play a different role in hyphal morphogenesis. In addition, the chitin contents of these double mutants were higher than those of the chsB single mutant. When chsA was expressed ectopically under the chsB promoter in the chsB mutant, the growth defects caused by chsB repression were not remedied at all, although an increased level of chsA mRNA was observed. Thus, it is suggested that the gene products of chsA and chsB themselves have different functions in hyphal morphogenesis.

Aspergillus nidulans↗