Inducible Nitric Oxide Synthase in Heart Tissue and Nitric Oxide in Serum of Trypanosoma cruzi-Infected Rhesus Monkeys: Association with Heart Injury

Chagas disease, a neglected tropical disease caused by the protozoan Trypanosoma cruzi, afflicts from 8 to 15 million people in the Latin America. Chronic chagasic cardiomyopathy (CCC) is the most frequent manifestation of Chagas disease. Currently, patient management only mitigates CCC symptoms. The pathogenic factors leading to CCC remain unknown; therefore their comprehension may contribute to develop more efficient therapies. In patients, high nitric oxide (NO) levels have been associated with CCC severity. In T. cruzi-infected mice, NO, mainly produced via inducible nitric oxide synthase (iNOS/NOS2), is proposed to work in parasite control. However, the participation of iNOS/NOS2 and NO in T. cruzi control and heart injury has been questioned. Here, infected rhesus monkeys and iNOS/NOS2-deficient mice were used to explore the participation of iNOS/NOS2-derived NO in heart injury in T. cruzi infection. Chronically infected monkeys presented electrical abnormalities, myocarditis and fibrosis, resembling the spectrum of human CCC. Moreover, cardiomyocyte lesion correlated with iNOS/NOS2+ cells infiltrating the cardiac tissue. Our findings support that parasite-driven iNOS/NOS2+ cells accumulation in the cardiac tissue and NO overproduction contribute to cardiomyopathy severity, mainly disturbing the pathway involved in electrical synchrony in T. cruzi infection

Fatores associados à amamentação na primeira hora de vida

OBJETIVO: Identificar fatores associados à amamentação na primeira hora de vida (Passo 4 da Iniciativa Hospital Amigo da Criança). MÉTODOS: Foi realizado estudo transversal com amostra representativa de parturientes em maternidades do Rio de Janeiro, RJ, entre 1999 e 2001. Foram excluídos recém-nascidos ou mães com restrição ao aleitamento materno, resultando em amostra de 8.397 binômios. Foi adotado modelo Poisson com efeitos aleatórios ao nível das maternidades, em abordagem hierarquizada com três níveis: distal, intermediário e proximal para características maternas, do recém-nascido, e de assistência ao pré-natal e hospitalar. RESULTADOS: Amamentaram na primeira hora de vida 16% das mães. O aleitamento materno nesse período foi menos prevalente entre os recém-nascidos com intercorrências imediatas após o parto (RP = 0,47; IC99% 0,15;0,80); entre as mães que não tiveram contato com os recém-nascidos na sala de parto (RP = 0,62; IC99% 0,29;0,95), as que tiveram parto cesariano (RP = 0,48; IC99% 0,24;0,72); e cujo parto ocorreu em maternidade privada (RP = 0,06; IC99% 0,01;0,19) ou conveniada com o Sistema Único de Saúde (RP = 0,16; IC99% 0,01;0,30). O efeito de contexto das maternidades foi estatisticamente significativo. CONCLUSÕES: Em nível individual, a amamentação na primeira hora de nascimento foi prejudicada por práticas inadequadas nas maternidades, em particular as privadas e conveniadas com o Sistema Único de Saúde. O efeito de grupo das maternidades e a ausência de fatores individuais maternos que expliquem o desfecho sugerem que as mães têm pouco ou nenhum poder de decisão sobre essa amamentação e dependem das práticas institucionais vigentes nas maternidades

Study of ordered hadron chains with the ATLAS detector

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A search for resonances decaying into a Higgs boson and a new particle X in the XH→qqbb final state with the ATLAS detector

A search for heavy resonances decaying into a Higgs boson ($H$) and a new particle ($X$) is reported, utilizing 36.1 fb$^{-1}$ of proton-proton collision data at $\sqrt{s} =$ 13 TeV collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle $X$ is assumed to decay to a pair of light quarks, and the fully hadronic final state $XH \rightarrow q\bar q'b\bar b$ is analysed. The search considers the regime of high $XH$ resonance masses, where the $X$ and $H$ bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of $XH$ mass versus $X$ mass is scanned for evidence of a signal, over a range of $XH$ resonance mass values between 1 TeV and 4 TeV, and for $X$ particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of $XH$ and $X$ masses, on the production cross-section of the $XH\rightarrow q\bar q'b\bar b$ resonance

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements