Evidence for a protective role of tumor necrosis factor in the acute phase of Trypanosoma cruzi infection in mice.

A possible role for tumor necrosis factor (TNF) alpha during Trypanosoma cruzi infection was explored by using transgenic mice expressing in blood high levels of a soluble TNFR1-FcIgG3 fusion protein, which neutralizes the effects of TNF in vivo. Nontransgenic littermates were used as controls. The transgenic mice showed high susceptibility to T. cruzi infection. Inocula sublethal for control mice resulted in over 80% mortality associated with higher levels of parasites in the blood. In histological sections of the hearts of transgenic mice, large parasitic clusters without inflammatory cell infiltrates around the parasites were seen, while smaller parasitic clusters associated with leukocytes were seen in control mice. No difference in specific antibody response or lymphocyte composition of the spleen was found between transgenic and control mice, although the unresponsiveness of spleen cells to concanavalin A stimulation in vitro, typical of the acute phase of T. cruzi infection, was less pronounced in transgenic mice. Infected transgenic mice produced higher levels of gamma interferon than did control mice. These results confirm that TNF is involved in mechanisms leading to parasite clearance and protection from death in the acute phase of T. cruzi infection. More importantly, the data reveal that TNF is necessary for the establishment of effective tissue inflammation and parasite load control in acute experimental Chagas' disease myocarditis

Uso de estratégias de leitura por alunos do ensino médio

O presente estudo verificou o uso de estratégias metacognitivas de leitura por alunos do ensino médio. Participaram 487 alunos do ensino médio de escolas públicas, 55,7%, e particulares ,44,3%, sendo 58,3% do sexo feminino. A idade variou de 14 a 21 anos com média de 16,2 anos e desvio padrão de 1,27. O procedimento utilizado foi a aplicação coletiva por classe de uma escala de estratégias metacognitivas de leitura. Os resultados revelaram que as mais utilizadas pelos participantes foram as de solução de problemas, especialmente durante a leitura. Os participantes do sexo feminino (M=46,10; DP=12,42) demonstraram utilizar estratégias de leitura mais freqüentemente que os do masculino (M=39,13; DP=13,94). Houve diferenças estatisticamente significativas quanto ao uso de estratégias metacognitivas de leitura entre 15 e 17 anos [F(7,480)=2,33; p<0,02]. Verificou-se diferença de uso também entre a primeira série do ensino médio em relação a terceira e habilitação ao magistério [F(3,484)=12,36; p<0,00]

Everolimus-Eluting Stents or Bypass Surgery for Left Main Coronary Artery Disease

BACKGROUND Patients with obstructive left main coronary artery disease are usually treated with coronary-artery bypass grafting (CABG). Randomized trials have suggested that drug-eluting stents may be an acceptable alternative to CABG in selected patients with left main coronary disease.METHODS We randomly assigned 1905 eligible patients with left main coronary artery disease of low or intermediate anatomical complexity to undergo either percutaneous coronary intervention (PCI) with fluoropolymer-based cobalt-chromium everolimus-eluting stents (PCI group, 948 patients) or CABG (CABG group, 957 patients). Anatomic complexity was assessed at the sites and defined by a Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score of 32 or lower (the SYNTAX score reflects a comprehensive angiographic assessment of the coronary vasculature, with 0 as the lowest score and higher scores [ no upper limit] indicating more complex coronary anatomy). The primary end point was the rate of a composite of death from any cause, stroke, or myocardial infarction at 3 years, and the trial was powered for noninferiority testing of the primary end point (noninferiority margin, 4.2 percentage points). Major secondary end points included the rate of a composite of death from any cause, stroke, or myocardial infarction at 30 days and the rate of a composite of death, stroke, myocardial infarction, or ischemia-driven revascularization at 3 years. Event rates were based on Kaplan-Meier estimates in time-to-first-event analyses.RESULTS At 3 years, a primary end-point event had occurred in 15.4% of the patients in the PCI group and in 14.7% of the patients in the CABG group (difference, 0.7 percentage points; upper 97.5% confidence limit, 4.0 percentage points; P = 0.02 for noninferiority; hazard ratio, 1.00; 95% confidence interval, 0.79 to 1.26; P = 0.98 for superiority). The secondary end-point event of death, stroke, or myocardial infarction at 30 days occurred in 4.9% of the patients in the PCI group and in 7.9% in the CABG group (P< 0.001 for noninferiority, P = 0.008 for superiority). The secondary end-point event of death, stroke, myocardial infarction, or ischemia-driven revascularization at 3 years occurred in 23.1% of the patients in the PCI group and in 19.1% in the CABG group (P = 0.01 for noninferiority, P = 0.10 for superiority).CONCLUSIONS In patients with left main coronary artery disease and low or intermediate SYNTAX scores by site assessment, PCI with everolimus-eluting stents was noninferior to CABG with respect to the rate of the composite end point of death, stroke, or myocardial infarction at 3 years. (Funded by Abbott Vascular; EXCEL ClinicalTrials.gov number, NCT01205776.