Blocking central leukotrienes synthesis affects vasopressin release during sepsis

Recent studies revealed that vasopressinergic neurons have a high content of cys-leukotriene C(4) (LTC(4)) synthase, a critical enzyme in cys-leukotriene synthesis that may play a role in regulating vasopressin secretion. This study investigates the role of this enzyme in arginine vasopressin (AVP) release during experimentally induced sepsis. Male Wistar rats received an i.c.v. injection of 3-[1-(p-chlorobenzyl)-5-(isopropyl)-3-tert-butylthioindol-2-yl]-2, 2-dimethylpropanoic acid (MK-886) (1.0 mu g/kg), a leukotrienes (LTs) synthesis inhibitor, or vehicle, 1 h before cecal ligation and puncture (CLP) or sham operation. In one group of animals the survival rate was monitored for 3 days. In another group, the animals were decapitated at 0, 4, 6, 18 and 24 h after CLP or sham operation, and blood was collected for hematocrit, serum sodium and nitrate, plasma osmolality, protein and AVP determination. A third group was used for blood pressure measurements. The neurohypophysis was removed for quantification of AVP content, and the hypothalamus was dissected for LTC4 synthase analysis by Western blot. Mortality after CLP was reduced by the central administration of MK-886. The increase in plasma AVP levels and hypothalamus LTC4 synthase content in the initial phase of sepsis was blocked, whereas the decrease in neurohypophyseal AVP content was partially reversed. Also the blood pressure drop was abolished in this phase. The increase of serum nitric oxide and hematocrit was reduced, and the decrease in plasma protein and osmolality was not affected by the LTs blocker. In the final phase of sepsis, the plasma AVID level and the hypothalamic LTC4 synthase content were at basal levels. The central administration of MK-886 increased the hypothalamic LTC4 synthase content but did not alter the plasma and neurohypophysis AVID levels observed, or the blood pressure during this phase. These results suggest that the central LTs are involved in the vasopressin release observed during sepsis. (C) 2009 IBRO. Published by Elsevier Ltd. All rights reserved

Metabolic rates of the antarctic amphipod Gondogeneia antarctica at different temperatures and salinities

Changes in environmental factors may deeply affect the energy budget of Antarctic organisms as many of them are stenothermal and/or stenohaline ectotherms. In this context, the aim of this study is to contribute to knowledge on variations in the energy demand of the Antarctic amphipod, Gondogeneia antarctica as a function of temperature and salinity. Experiments were held at the Brazilian Antarctic Station "Comandante Ferraz", under controlled conditions. Animals collected at Admiralty Bay were acclimated to temperatures of 0ºC; 2.5ºC and 5ºC and to salinities of 35, 30 and 25. Thirty measurements were made for each of the nine combinations of the three temperatures and three salinities, totalling 270 measurements. Metabolic rates were assessed by oxygen consumption and total nitrogenous ammonia excretion, in sealed respirometers. When acclimated to salinities 30 or 35, metabolic rates at 0ºC and 2.5ºC were very similar indicating a possible mechanism of metabolic compensation for temperature. At 5.0ºC, however, metabolic rates were always higher. Lower salinities enhanced the effects of temperature on metabolism and ammonia excretion rates. The physiological adaptations of individuals of G. antarctica suggest adaptive mechanisms for energy saving, adjusted to an environment with stable conditions of temperature and salinity. Little is known about the joint effects of salinity and temperature and this study is an important contribution to the understanding of the mechanism of polar organisms in their adaptation to both factors.Alterações ambientais podem modificar a alocação de energia dos organismos, principalmente dos ectotermos estenotérmicos e/ou estenohalinos. Nesse contexto, este trabalho contribui com o conhecimento da demanda de energia do anfípode antártico Gondogeneia antarctica em função da temperatura e da salinidade. Experimentos foram realizados na Estação Antártica Brasileira "Comandante Ferraz", em condições laboratoriais controladas. Animais coletados na Baía do Almirantado foram aclimatados a temperaturas de 0ºC; 2.5ºC e 5ºC e salinidades de 35, 30 and 25. Foram realizadas trinta medições para cada uma das nove combinações das três temperaturas com as três salinidades, totalizando 270 medições. As taxas metabólicas foram estimadas por meio do consumo de oxigênio e excreção de amônia, em câmaras respirométricas seladas. Quando aclimatados a salinidades 30 ou 35, as taxas metabólicas a 0ºC e 2.5ºC foram semelhantes indicando possível mecanismo de compensação térmica, nessa faixa de variação dos fatores. A 5.0ºC, no entanto, as taxas metabólicas foram sempre mais elevadas. Baixas salinidades potencializaram os efeitos da temperatura no consumo de oxigênio e na excreção de produtos nitrogenados. Os resultados estão relacionados a mecanismos adaptativos para economia de energia em indivíduos G. antarctica, ajustados a um ambiente que tem condições estáveis de temperatura e de salinidade. Pouco se sabe sobre os efeitos conjugados da salinidade e temperatura nos organismos e este trabalho é uma importante contribuição para esse conhecimento.CNPq-PROANTA

Xenograft Transplantation of Human Malignant Astrocytoma Cells Into Immunodeficient Rats: An Experimental Model of Glioblastoma

INTRODUCTION: Astrocytic gliomas are the most common intracranial central nervous system neoplasias, accounting for about 60% of all primary central nervous system tumors. Despite advances in the treatment of gliomas, no effective therapeutic approach is yet available; hence, the search for a more realistic model to generate more effective therapies is essential. OBJECTIVE: To develop an experimental malignant astrocytoma model with the characteristics of the human tumor. METHOD: Primary cells from subcutaneous xenograft tumors produced with malignant astrocytoma U87MG cells were inoculated intracerebrally by stereotaxis into immunosuppressed (athymic) Rowett rats. RESULTS: All four injected animals developed non-infiltrative tumors, although other glioblastoma characteristics, such as necrosis, pseudopalisading cells and intense mitotic activity, were observed. CONCLUSION: A malignant astrocytoma intracerebral xenograft model with poorly invasive behavior was achieved in athymic Rowett rats. Tumor invasiveness in an experimental animal model may depend on a combination of several factors, including the cell line used to induce tumor formation, the rat strains and the status of the animal's immune system

AS POLÍTICAS PÚBLICAS DE EDUCAÇÃO: AVALIAÇÃO, CURRÍCULO E FORMAÇÃO DE PROFESSORES DE MATEMÁTICA

This article aims to present the public policies of education, evaluation, curriculum and teacher training of mathematics for the use of Digital Technologies of Information and Communication in classes. To this end, bibliographic research of a qualitative and descriptive nature was carried out to elaborate the content of the study. To achieve a better understanding, the research begins with a brief history of the concept of "Mathematics". Therefore, the teaching of Mathematics in the educational context will be presented; consequently, teacher training in the current scenario. Finally, the use of digital technologies in the teaching of mathematics. It is concluded that ICTs are essential learning instruments today and, for teachers to correctly perform these tools in educational practice, it is necessary to seek continuing education.Este artículo tiene como objetivo presentar las políticas públicas de educación, evaluación, currículo y formación docente de matemáticas para el uso de las Tecnologías Digitales de la Información y la Comunicación en las clases. Con este fin, se realizó una investigación bibliográfica de carácter cualitativo y descriptivo para preparar el contenido de la misma. Para lograr una mejor comprensión, la investigación comenzará con una breve historia del concepto de "Matemáticas". Por lo tanto, se presentará la enseñanza de las Matemáticas en el contexto educativo; En consecuencia, la formación del profesorado en el escenario actual. Finalmente, el uso de tecnologías digitales en la enseñanza de las matemáticas. Se concluye que las TIC son instrumentos esenciales de aprendizaje hoy en día y, para que los profesores hagan el uso correcto de estas herramientas en la práctica educativa, es necesario buscar la educación continua.O presente artigo tem como objetivo apresentar as políticas públicas de educação, avaliação, currículo e formação docente de matemática para o uso de Tecnologias Digitais de Informação e Comunicação nas aulas. Para tanto, foram realizadas pesquisas bibliográficas de cunho qualitativo e caráter descritivo para elaborar o conteúdo do estudo. Para o alcance de um melhor entendimento, a pesquisa inicia com um breve histórico do conceito de “Matemática”. Logo, apresentar-se-á o ensino da Matemática no contexto educacional; consequentemente, a formação docente no cenário atual. Por fim, o uso das tecnologias digitais no ensino da Matemática. Conclui-se que as TIC’s são instrumentos de aprendizagens essenciais atualmente e, para que os professores desempenhem corretamente estas ferramentas na prática educativa, é necessário buscar a formação continuada.  O presente artigo tem como objetivo apresentar as políticas públicas de educação, avaliação, currículo e formação docente de matemática para o uso de Tecnologias Digitais de Informação e Comunicação nas aulas. Para tanto, foram realizadas pesquisas bibliográficas de cunho qualitativo e caráter descritivo para elaborar o conteúdo do estudo. Para o alcance de um melhor entendimento, a pesquisa inicia com um breve histórico do conceito de “Matemática”. Logo, apresentar-se-á o ensino da Matemática no contexto educacional; consequentemente, a formação docente no cenário atual. Por fim, o uso das tecnologias digitais no ensino da Matemática. Conclui-se que as TIC’s são instrumentos de aprendizagens essenciais atualmente e, para que os professores desempenhem corretamente estas ferramentas na prática educativa, é necessário buscar a formação continuada.

Mineral and organomineral sources of nitrogen to maize agronomic performance

Nitrogen (N) is one of the nutrients absorbed in great quantity by maize crop. Also, N fertilizers are of high costs and subject to large losses into the agricultural environment. There are various categories of fertilizers known as fertilizers of improved efficiency that can minimize such N losses. The objective of this study was to evaluate the effect of different sources and doses of N in maize agronomic performance. The experiment was installed in randomized blocks, with four replications, designed as a factorial 5 x 5 + 1, constituted by five N sources (urea, urea polymerized, urea with NBPT, organomineral with and without NBPT), five N doses (40, 80, 120, 160, 200 kg ha-1) plus a control (no N supply). The chlorophyll contents and grain yield were evaluated. The results showed no differences for the different N sources, indicating that the organomineral sources are as efficient as the mineral sources. The addition of N fertilizers in increasing doses, regardless of the source tested, has increased the levels of chlorophylls and grain yiled

Incidence and risk factors for preeclampsia in a cohort of healthy nulliparous pregnant women : a nested case-control study

The objective of this study is to determine the incidence, socio-demographic and clinical risk factors for preeclampsia and associated maternal and perinatal adverse outcomes. This is a nested case-control derived from the multicentre cohort study Preterm SAMBA, in fve diferent centres in Brazil, with nulliparous healthy pregnant women. Clinical data were prospectively collected, and risk factors were assessed comparatively between PE cases and controls using risk ratio (RR) (95% CI) plus multivariate analysis. Complete data were available for 1,165 participants. The incidence of preeclampsia was 7.5%. Body mass index determined at the frst medical visit and diastolic blood pressure over 75mmHg at 20 weeks of gestation were independently associated with the occurrence of preeclampsia. Women with preeclampsia sustained a higher incidence of adverse maternal outcomes, including C-section (3.5 fold), preterm birth below 34 weeks of gestation (3.9 fold) and hospital stay longer than 5 days (5.8 fold) than controls. They also had worse perinatal outcomes, including lower birthweight (a mean 379g lower), small for gestational age babies (RR 2.45 [1.52–3.95]), 5-minute Apgar score less than 7 (RR 2.11 [1.03–4.29]), NICU admission (RR 3.34 [1.61–6.9]) and Neonatal Near Miss (3.65 [1.78–7.49]). Weight gain rate per week, obesity and diastolic blood pressure equal to or higher than 75mmHg at 20 weeks of gestation were shown to be associated with preeclampsia. Preeclampsia also led to a higher number of C-sections and prolonged hospital admission, in addition to worse neonatal outcomes

Metabolomics applied to maternal and perinatal health : a review of new frontiers with a translation potential

The prediction or early diagnosis of maternal complications is challenging mostly because the main conditions, such as preeclampsia, preterm birth, fetal growth restriction, and gestational diabetes mellitus, are complex syndromes with multiple underlying mechanisms related to their occurrence. Limited advances in maternal and perinatal health in recent decades with respect to preventing these disorders have led to new approaches, and “omics” sciences have emerged as a potential field to be explored. Metabolomics is the study of a set of metabolites in a given sample and can represent the metabolic functioning of a cell, tissue or organism. Metabolomics has some advantages over genomics, transcriptomics, and proteomics, as metabolites are the final result of the interactions of genes, RNAs and proteins. Considering the recent “boom” in metabolomic studies and their importance in the research agenda, we here review the topic, explaining the rationale and theory of the metabolomic approach in different areas of maternal and perinatal health research for clinical practitioners. We also demonstrate the main exploratory studies of these maternal complications, commenting on their promising findings. The potential translational application of metabolomic studies, especially for the identification of predictive biomarkers, is supported by the current findings, although they require external validation in larger datasets and with alternative methodologies

Mean arterial blood pressure : potential predictive tool for preeclampsia in a cohort of healthy nulliparous pregnant women

Background: Prediction of preeclampsia is a challenge to overcome. The vast majority of prospective studies in large general obstetric populations have failed in the purpose of obtain a useful and effective model of prediction, sometimes based on complex tools unavaible in areas where the incidence of preeclampsia is the highest. The goal of this study was to assess mean arterial blood pressure (MAP) levels at 19–21, 27–29 and 37–39 weeks of gestation and performance of screening by MAP for the prediction of preeclampsia in a Brazilian cohort of healthy nulliparous pregnant women. Methods: This was a cohort approach to a secondary analysis of the Preterm SAMBA study. Mean arterial blood pressure was evaluated at three different time periods during pregnancy. Groups with early-onset preeclampsia, late-onset preeclampsia and normotension were compared. Increments in mean arterial blood pressure between 20 and 27 weeks and 20 and 37 weeks of gestation were also calculated for the three groups studied. The accuracy of mean arterial blood pressure in the prediction of preeclampsia was determined by ROC curves. Results: Of the 1373 participants enrolled, complete data were available for 1165. The incidence of preeclampsia was 7.5%. Women with early-onset preeclampsia had higher mean arterial blood pressure levels at 20 weeks of gestation, compared to the normotensive group. Women with late-onset preeclampsia had higher mean arterial blood pressure levels at 37 weeks of gestation, than the normotensive groups and higher increases in this marker between 20 and 37 weeks of gestation. Based on ROC curves, the predictive performance of mean arterial blood pressure was higher at 37 weeks of gestation, with an area under the curve of 0.771. Conclusion: As an isolated marker for the prediction of preeclampsia, the performance of mean arterial blood pressure was low in a healthy nulliparous pregnant women group. Considering that early-onset preeclampsia cases had higher mean arterial blood pressure levels at 20 weeks of gestation, future studies with larger cohorts that combine multiple markers are needed for the development of a preeclampsia prediction model