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Recent Raman and Raman optical activity (ROA) results have demonstrated that dimethyl sulfoxide (DMSO) induces the selective conversion of α-helix motifs into the poly(L-proline) II (PPII) helix conformation in an array of proteins, while β-sheets remain mostly unaffected. Human serum albumin (HSA), a highly α-helical protein, underwent the most dramatic changes and, therefore, was selected as a model for further investigations into the mechanism of this conformational change. Herein we report the use of two-dimensional ROA correlation analysis applying synchronous, autocorrelation, and moving windows approaches in order to understand the conformational transitions in HSA as a function of DMSO concentration. Our results indicate that the destabilization of native α-helix starts at DMSO concentrations as little as 20% in water (v/v), with the transition to PPII helix being complete at ~80% DMSO. These results clearly indicate that any protein preparation containing relatively low concentrations of DMSO should consider possible disruptions in α-helical domains.

Phyllanthus niruri L., commonly known in Brazil as 'quebra-pedra', has long been used in the treatment of diverse diseases and especially urolithiasis. The therapeutic effects of P. niruri are attributed to various compounds present in the plant, including the hydrolysable tannin corilagin. In the present study, high-performance liquid chromatography (HPLC-/PAD) profiles of leaves and commercial extracts of P. niruri were examined and three compounds, found to be present in all of the samples studied, were isolated by open column chromatography over C18)silica gel followed by preparative HPLC. These compounds were identified by nuclear magnetic resonance as corilagin, rutin and ethyl 3,4,5-trihydroxybenzoate. Corilagin, which has been proposed as a phytochemical marker for P. niruri, was employed as an external standard in the development and validation of a rapid and efficient qualitative and quantitative HPLC assay for the analyte. The method may be applied in the standardization of herbs and phytomedicines commercialized in Brazil as quebra-pedra.

Chronic inflammation presented in rheumatoid arthritis (RA) is associated with systemic manifestations, that include micronutrient deficiency, changes in body composition and cardiac morphofunctional alterations. The aim of this study is to evaluate the association of serum vitramin D and body composition with cardiac geometric pattern in patients with RA. Methods: 30 patients with RA were submitted to clinical, nutritional and biochemical evaluation. Bioimpedance analysis and dual-energy X-ray absorptiometry (DEXA) was performed to evaluate body composition. Transthoracic dopller- echocardiography was performed to evaluate left ventricle mass and relative wall thickness (RWT) in order to find cardiac geometry patterns. Patients were divided in Normal or abnormal pattern (concentric remodeling or concentric hypertrophy.) Results: The mean age was 53±9 years; 70% were woman, 43% presented with hypertension. All patients have been treated with methotrexate and a biological agent and presented with Disease a...