Federal University of São Paulo

About: Federal University of São Paulo is a education organization based out in São Paulo, Brazil. It is known for research contribution in the topics: Population & Transplantation. The organization has 27971 authors who have published 49365 publications receiving 935536 citations. The organization is also known as: Universidade Federal de São Paulo & Universidade Federal de Sao Paulo.

High Prevalence of BRAF Mutation in a Brazilian Cohort of Patients With Sporadic Papillary Thyroid Carcinomas Correlation With More Aggressive Phenotype and Decreased Expression of Iodide-Metabolizing Genes

Abstract: BACKGROUND: Although several studies undoubtedly demonstrated that BRAF mutation is an important genetic event in the pathogenesis of papillary thyroid carcinoma (PTC), its prognostic significance and correlation with less differentiated states remains unclear. It has been suggested that the discrepancy may be at least partially due to the insufficient number of cases analyzed, epidemiologic factors, and a combination of different variants of PTC included in these studies. METHODS: In this context, the prevalence of the BRAF mutation in a Brazilian cohort of PTCs (n = 120) was first assessed and correlated with clinicopathologic features. The BRAF exon 15 mutation was evaluated by direct sequencing. Furthermore, using quantitative polymerase chain reaction, the issue of whether the expression level of the iodide-metabolizing genes (NIS and TSHR) was correlated with BRAF mutational status was investigated. RESULTS: A high prevalence of the BRAF mutation was found in PTC cases (48%). The BRAF mutation was found to be significantly associated with the classic variant of PTC (66%; P < .0001), although it was found in the follicular variant as well (21%). Subtype stratification demonstrated that the BRAF V600E mutation was associated with tumor size, extrathyroid invasion, the presence of lymph node metastasis and risk of disease recurrence, and mortality in patients with the classic variant of PTC. Moreover, the expression levels of NIS and TSHR were remarkably lower in PTCs harboring the BRAF V600E mutation. CONCLUSIONS: These findings provide further evidence that BRAF might be associated with a more aggressive phenotype and less differentiated state due to decreased expression of iodide-metabolizing genes. The search for a BRAF mutation in the current study population appears to be valuable for predicting prognosis and guiding management in patients with PTC. Cancer 2009. © 2009 American Cancer Society.

Reference Values for Dynamic Responses to Incremental Cycle Ergometry in Males and Females Aged 20 to 80

Abstract: Interpretation of incremental cardiopulmonary exercise tests (CPET) might be enhanced by considering the simultaneous rates of change of certain key variables, e.g., Δ oxygen uptake/ Δ work rate ( ΔV˙ o 2/ Δ WR), Δ heart rate/ ΔV˙ o 2 ( Δ HR/ ΔV˙ o 2), Δ ventilation/ Δ carbon dioxide production ( ΔV˙ e/ ΔV˙ co 2), and the linearized Δ tidal volume/ ΔV˙ e ( Δ Vt/ Δ lnV˙ e) relationships. However, there are no published age- and sex-dependent reference values for these relationships that were appropriately obtained in randomly selected subjects. We therefore prospectively evaluated 120 sedentary individuals (60 male, 60 female, age 20 to 80 yr) who were randomly selected from more than 8,000 subjects, and submitted to standard ramp-incremental CPET on an electronically braked cycle ergometer. We found that sex and age significantly influenced several of the dynamic relationships, in addition to anthropometric attributes (p < 0.05). A comprehensive set of linear prediction equations is provided; the limits o...