Immunohistochemical identification of nail matrix melanocytes.

BACKGROUND: No previous studies have been conducted to determine the normal number of nail matrix melanocytes in Latin American individuals. The objective of this work was to determine the number of melanocytes per linear millimetre present in the nail matrix and the nail bed in samples obtained from Colombian individuals. METHODS: Twenty-six unilateral biopsies were taken from 19 cadavers subjected to clinical and medico-legal autopsies. These biopsy samples were processed with conventional histotechnology and immunohistochemistry (IHC) with anti-HMB-45 and anti-MiTF. Three sets of photographs (HE, HMB-45 and MiTF) were taken of each biopsy sample and independently assessed by three pathologists. Each observer counted the number of melanocytes present in 1 linear mm of the nail matrix or bed. RESULTS: We found an average of 4.6 melanocytes x linear mm with H & E staining, 9.8 with HMB-45 and 12.4 with MiTF. CONCLUSIONS: The use of IHC significantly increases and facilitates the identification of melanocytes in unilateral biopsies. Our IHC counts exceed the averages found in the literature. This finding warrants new studies to verify whether the Colombian population presents higher numbers of melanocytes in the nail matrix than other populations or whether the observed increase is a result of the use of MiTF.

Efficiency of tranexamic acid in perioperative blood loss in hip arthroplasty: a systematic literature review and meta-analysis.

INTRODUCTION AND OBJECTIVE: Tranexamic acid (TXA) is an antifibrinolytic drug used to reduce bleeding in mortality risk situations such as trauma. Our objective was to conduct a systematic literature review to evaluate the effectiveness and safety of TXA in reducing bleeding in hip arthroplasty. MATERIAL AND METHODS: A systematic literature review and meta-analysis of primary studies similar to controlled trials was performed. Literature was searched in MEDLINE, Embase, Cochrane, LILACS, SciELO and Google Scholar. The review was proposed and undertaken by 2 reviewers and the inclusion criteria were: a) patients undergoing arthroplasty for primary unilateral hip replacement; b) comparison of a treatment group with TXA to a control group that received a placebo or no treatment at all, and c) outcome measures, total blood loss, number of patients receiving allogeneic transfusion and/or incidence of thromboembolic complications. The search was restricted to studies published from 1966 to June 2013. RESULTS: A total of 16 studies with 246 patients were retrieved for this review. The total blood loss outcome evidenced a weighted mean difference in favor of TXA vs. controls undergoing hip arthroplasty (-0.45 [P<0.001, 95% CI -0.65 to -0.24]). Weighted relative risk was estimated for the allogeneic transfusion requirement outcome, showing a trend in favor the TXA arm, with fewer patients requiring allogeneic transfusion in hip surgery (0.8 [P<0.02, 95% CI 0.57 to 1.11]); however, this trend was not statistically significant. LIMITATIONS: There is a noticeable difference in methods for quantifying total blood loss across the studies reviewed. The need for transfusion outcomes are probably not significant taking into account the number of events in the TXA group. CONCLUSIONS: TXA can be routinely used to reduce intra- and post-operative blood loss in primary hip arthroplasty.