RESUMO
Leptospirosis is a world-wide zoonotic disease caused by pathogenic Leptospira and can be asymptomatic or can cause clinical signs ranging from influenza-like to multi-organ failure and death in severe cases. While species and strain specificity can play a major role in disease presentation, the hamster is susceptible to most leptospiral infections and is the model of choice for vaccine efficacy testing. During evaluation of blood smears from hamsters challenged with different species and strains of Leptospira, a circulating population of large, mononuclear, lipid-filled cells, most similar to foamy macrophages (FMs), was detected. Circulating FMs were identified by Giemsa staining and verified by scanning and transmission electron microscopy. FMs were found in the circulating blood of all Leptospira-challenged hamsters, indicating that the finding was not species or strain specific, although higher numbers of FMs tended to correlate with severity of disease. The unique finding of circulating FMs in the hamster model of leptospirosis can yield additional insights into the pathogenesis of leptospirosis and other diseases that induce circulating FMs.
RESUMO
A 15-year retrospective review of neonates ventilated in the main intensive care unit at the University Hospital of the West Indies was conducted. During the study period, 153 neonates were ventilated, of whom 80 (52%) survived. The most common reason for admission was respiratory distress syndrome, which accounted for 67% (102/153) of admissions, 53 (52%) of these infants survived. Improving outcome will require strategies directed at improving neonatal intensive care.
Assuntos
Hospitais Universitários , Doenças do Prematuro , Unidades de Terapia Intensiva , Respiração Artificial/métodos , Síndrome do Desconforto Respiratório do Recém-Nascido , Feminino , Mortalidade Hospitalar , Humanos , Mortalidade Infantil , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Recém-Nascido de Baixo Peso , Recém-Nascido , Doenças do Prematuro/mortalidade , Doenças do Prematuro/terapia , Recém-Nascido de muito Baixo Peso , Tempo de Internação , Masculino , Síndrome do Desconforto Respiratório do Recém-Nascido/mortalidade , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Taxa de Sobrevida , Resultado do Tratamento , Índias Ocidentais/epidemiologiaRESUMO
Photosynthetic responses of sunflower plants grown for 52 d in ambient and elevated CO(2) (A=350 or E=700 micromol mol(-1), respectively) and subjected to no (control), mild or severe water deficits after 45 d were analysed to determine if E modifies responses to water deficiency. Relative water content, leaf water potential (Psi(w)) and osmotic potential decreased with water deficiency, but there were no effects of E. Growth in E decreased stomatal conductance (g(s)) and thereby transpiration, but increased net CO(2) assimilation rate (P(n), short-term measurements); therefore, water-use efficiency increased by 230% (control plants) and 380% (severe stress). Growth in E did not affect the response of P(n) to intercellular CO(2) concentration, despite a reduction of 25% in Rubisco content, because this was compensated by a 32% increase in Rubisco activity. Analysis of chlorophyll a fluorescence showed that changes in energy metabolism associated with E were small, despite the decreased Rubisco content. Water deficits decreased g(s) and P(n): metabolic limitation was greater than stomatal at mild and severe deficit and was not overcome by elevated CO(2). The decrease in P(n) with water deficiency was related to lower Rubisco activity rather than to ATP and RuBP contents. Thus, there were no important interactions between CO(2) during growth and water deficit with respect to photosynthetic metabolism. Elevated CO(2 )will benefit sunflower growing under water deficit by marginally increasing P(n), and by slowing transpiration, which will decrease the rate and severity of water deficits, with limited effects on metabolism.