Erythropoietin Attenuates Apoptosis After Ischemia-Reperfusion–Induced Renal Injury in Transiently Hyperglycemic Wister Rats

AbstractBackgroundHyperglycemia is associated with a decreased tolerance to ischemia and an increased severity of renal ischemia reperfusion (I/R) injury. It has been suggested that erythropoietin (EPO) attenuates this effect in normoglycemic animals. This study sought to examine the effects of EPO on treatment renal I/R injury (IRI) in transiently hyperglycemic rats.Material and MethodsTwenty-eight male Wister rats anesthetized with isoflurane received glucose (2.5 g.kg−1 intraperitoneally) before right nephrectomy. They were randomly assigned to four groups: sham operation (S); IRI (ISO); IRI+EPO, (600 UI kg−1 low-dose EPO [EL]); and IRI+EPO 5000 UI kg−1 (high-dose EPO [EH]). IRI was induced by a 25-minute period of left renal ischemia followed by reperfusion for 24 hours. Serum Creatinine and glucose levels were measure at baseline (M1), immediately after the ischemic period (M2), and at 24 hours after reperfusion (M3). After sacrificing the animals, left kidney specimens were submitted for histological analysis including flow cytometry to estimate tubular necrosis and the percentages of apoptotic, dead or intact cells.ResultsScr in the ISO group was significantly higher at M3 than among the other groups. Percentages of early apoptotic cells in ISO group were significantly higher than the other groups. Percentages of late apoptotic cells in S and ISO groups were significantly greater than EL and EH groups. However, no significant intergroup differences were observed regarding the incidence of tubular necrosis.ConclusionsOur results suggested that, although not preventing the occurrence of tubular necrosis, EPO attenuated apoptosis and glomerular functional impairment among transiently hyperglycemic rats undergoing an ischemia/reperfusion insult

Identificação e mapeamento de áreas de milho na região sul do Brasil utilizando imagens MODIS Identification and mapping of maize areas in the south region of Brazil using MODIS images

O presente trabalho teve como proposta avaliar a identificação e o mapeamento das áreas de milho da região noroeste do Estado do Rio Grande do Sul a partir de dados multitemporais do sensor MODIS (Moderate Resolution Imaging Spectroradiometer) a bordo do satélite Earth Observing System - EOS-AM (Terra). O algoritmo de classificação supervisionada Spectral Angle Mapper (SAM) foi aplicado com sucesso em uma série multitemporal de imagens EVI pré-processadas. Verificou-se que as áreas classificadas como milho na imagem coincidiam plenamente com áreas mais extensas ou contínuas (> 90 ha) de milho. Áreas de menor extensão ou localizadas em encostas de morros, ao lado de vegetação arbórea, não foram detectadas pelo classificador devido à baixa resolução espacial das imagens. A maior utilidade prática da identificação e da classificação digital das áreas de milho obtidas das imagens MODIS está na sua aplicação para isolar ou complementar o mapeamento das áreas agrícolas visando ao seu monitoramento a partir de diferentes índices de vegetação, derivados de imagens de alta resolução temporal e baixa resolução espacial.<br>The present work had the proposal of evaluating the identification and mapping of maize areas in the northwestern region of the State of Rio Grande do Sul using multi-temporal data from MODIS (Moderate Resolution Imaging Spectroradiometer) sensor on board of the Earth Observing System satellite - EOS-AM (Terra). The supervised classification algorithm Spectral Angle Mapper (SAM) was successfully applied in a multi-temporal series of pre-processed EVI images. It was verified that the areas classified as maize in the image fully agree with more extensive or continuous maize areas (> 90 ha). Small or hillsides maize areas having close to shrub and wood vegetation were not detected by the classifier mainly due low spatial resolution of images. The main practical utility of maize’s areas digital classification and identification using MODIS images is in its application to isolate or to complement the crop areas mapping, in order to monitor these areas, using different vegetation indices derived from high temporal and low spatial resolution images