Tissue-specific regulation of IRS-2/PI 3-kinase association in aged rats.

We have examined the insulin-stimulated IRS-2 association with PI 3-kinase and the phosphorylation of AKT/PKB, which is functionally located downstream of the PI 3-kinase, in aged (obese) rats. The IRS-2 protein levels were similar in 2 and 20 month-old rats in both tissues, liver and muscle. There were reductions in insulin-induced IRS-2 tyrosine phosphorylation in liver and muscle, accompanied by a decrease in IRS-2/PI 3-kinase association and in AKT/PKB phosphorylation only in muscle tissue of aged rats. This regulation may be important in the altered glucose metabolism observed in aged (obese) rats.

Defects in insulin signal transduction in liver and muscle of pregnant rats.

Pregnancy is known to induce resistance, but the exact molecular mechanism involved is unknown. In the present study, we have examined the levels and phosphorylation state of the insulin receptor and of insulin receptor substrate 1 (IRS-1), as well as the association between IRS-1 and phosphatidylinositol 3-kinase (PI 3-kinase) in the liver and muscle of pregnant rats (day 20 of gestation) by immunoprecipitation and immunoblotting with anti-insulin receptor, anti-IRS-1, anti-PI 3-kinase and anti-phosphotyrosine antibodies. There were no changes in the insulin receptor concentration in the liver and muscle of pregnant rats. However, insulin stimulation of receptor autophosphorylation, as determined by immunoblotting with antiphosphotyrosine antibody, was reduced by 30 +/- 6% (p < 0.02) in muscle and 36 +/- 5% (p < 0.01) in liver at day 20 of gestation. IRS-1 protein levels decreased by 45 +/- 6% (p < 0.002) in liver and by 56 +/- 9% (p < 0.002) in muscle of pregnant rats. In samples previously immunoprecipitated with anti-IRS-1 antibody and blotted with antiphosphotyrosine antibody, the insulin-stimulated IRS-1 phosphorylation levels in the muscle and liver of pregnant rats decreased by 70 +/- 9% (p < 0.01) and 75 +/- 8% (p < 0.01), respectively. The insulin-stimulated IRS-1 association with PI 3-kinase decreased by 81 +/- 6% in muscle (p < 0.01) and 79 +/- 11% (p < 0.01) in the liver during pregnancy. These data suggest that changes in the early steps of insulin signal transduction may have a role in the insulin resistance observed in pregnancy.

[Evaluation of medical teaching of clinical medicine in 6th year internship-Medical School of USP]. / Avaliação do ensino médico de clínica médica no internato de sexto ano--Faculdade de Medicina da USP.

The authors analyzed the performance of student's during their stay at the University Hospital of São Paulo. The study was based on: theoretical evaluation (tests), number of hours dispensed on standard textbook study, and participation in seminars and/or classes. The opinion of the students about the quality of the study of the internal medicine was also analyzed. The average number of hours designated to study the textbook's was 5.8 +/- hours/week. There was an increase in the presence at seminars from 10% to 72%.

Vasculite urticariforme.Relato de caso e revisao de literatura. / Urticarial vasculitis. A case report and review of the literature

Relatamos o caso do paciente do sexo masculino, de 27 anos, com urticaria cronica como manifestacao de vasculite necrosante cutanea, associada a artrite, febre, emagrecimento e hipocomplementemia. A sindrome caracterizada neste paciente e semelhante aos casos previamente relatados como "vasculite hipocomplementemica", "vasculite necrosante associada a urticaria cronica" e "vasculite urticariforme". Apresentamos revisao de literatura e discussao do diagnostico diferencial e tratamento. Acreditamos que essa nova sindrome constitui uma subpopulacao distinta de patologia colageno-vascular