157 resultados para 393
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The ultrastructural features of the ganglia of the myenteric plexus exhibit changes according to the animal species. These myenteric ganglia in the duodenum of adult rats of the Wistar strain were characterized ultrastructurally in this work. Those ganglia were depicted as compact structures, composed of neurones and glial cells, forming a dense neuropil surrounded by a continuous basal lamina and collagen fibrils. Glial cell bodies were smaller and apparently more frequent than neuronal cell bodies, being morphologically distinguished by nuclear features. In the neuronal extensions granular and agranular synaptic vesicles of different sizes predominate, in addition to mitochondria and myelinized profiles. Gliofilaments were not observed on the glial extensions of the rats.
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Crystals of a myotoxic phospholipase A(2) from Bothrops neuwiedi pauloensis have been obtained. They diffracted at 2.5 Angstrom resolution using a synchrotron radiation source and belong to space group P3(1)21. Preliminary analysis shows that there are two molecules in the asymmetric unit. (C) 1999 Elsevier B.V. B.V. All rights reserved.
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Since the nineteenth century ships have been using ballast water (BW) for safety, stability, propulsion and maneuverability, as well as to redress loss of fuel weight and water consumption, and to maintain structural stress at acceptable levels. Ballast water has been spreading many non-native species around the globe, but little is known about the extent and potential significance of ship-mediated transfer of microorganisms. The global movements of ballast water by ships create a long-distance dispersal mechanism for human pathogens that may be important in the worldwide distribution of microorganisms, as well as for the epidemiology of waterborne diseases. Only a few studies have been carried out on this subject, most of them involving ballast water containing crustacean larvae and phytoplankton. Specialized microbiological studies on these waters are necessary to avoid a repeat of what happened in 1991, when epidemic cholera was reported in Peru and rapidly spread through Latin America and Mexico. In July of 1992, Vibrio cholerae was found in the USA and the Food and Drug Administration (FDA) determined that it came from ballast water of ships whose last port of call was in South America. In Brazil, just a few studies about the subject have been performed. An exploratory study by the Brazilian National Health Surveillance Agency (Agencia Nacional de Vigilancia Sanitaria - ANVISA) found in ballast water different microorganisms, such as fecal coliforms, Escherichia coli, Enterococcus faecalis, Clostridium perfringens, coliphages, Vibrio cholerae O1 and Vibrio cholerae non-O1. Until now, Brazil has been focusing only on organisms transported to its territory from other countries by ballast water, to avoid their establishment and dissemination in Brazilian areas. Studies that can assess the probability that water ballast carries pathogenic microorganisms are extremely important, as is the examination of ships that arrive in the country. Treatment of the human infections caused by BW exists but none is completely safe and efficient.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pentastomida é um táxon de organismos parasitas obrigatórios de sistema respiratório de vertebrados, principalmente répteis. Embora esse táxon seja muito importante para a compreensão da filogenia dos Metazoa, tem recebido pouca atenção. No Brasil, existem poucas coleções que abrigam espécies de pentastomídeos, quais sejam: a Coleção Helmintológica do Instituto Oswaldo Cruz (CHIOC), a Coleção de Invertebrados do Laboratório de Zoologia da Universidade Regional do Cariri (LAZ-URCA) e a Coleção Helmintológica do Laboratório de Parasitologia de Animais Silvestres (LAPAS). O presente trabalho descreve as espécies de pentastomídeos depositados na Coleção Helmintológia do LAPAS. O trato respiratório e as cavidades do corpo dos répteis foram removidos e analisados sob Microscópio Esteroscópico; quando encontrados os pentastomídeos, foram montados slides em meio Hoyer e identificados. Foram identificadas quatro espécies e outras três ficaram identificadas no nível de gênero, tendo sido registrados quatro novos hospedeiros para as espécies de pentastomídeos.
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The occurrence of 62 specimens of Agelaia pallipes caught in carrion traps using three types of baits (fish, cow liver and poultry viscera) in three different types of environments (rural, urban and forest area) in seven municipalities in Southeastern Brazil is reported here. This specific necrophagic behavior is discussed, since investigations concerning carrion wasps are scant in literature.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The xylanolytic system of Aspergillus versicolor is controlled by induction and carbon catabolite repression. Carboxymethylcellulose and wheat bran were the best inducers of xylanolytic activity. When the fungus was grown for 5 days on VOGEL's liquid medium with wheat bran, the optimal pH and temperature for xylanase production were 6.5 and 30 degrees C, respectively. Optimal conditions for the xylanolytic activity assay were at pH 6.0 and 55 degrees C. The half-life at 60 degrees C of the crude enzyme was 6.5 and 21 minutes, in the absence or presence of substrate, respectively.Xylan is the main hemicellulosic component of plant biomass being present in appreciable quantities in agricultural and several agroindustrial wastes. From the products of xylan enzymatic hydrolysis it is possible to obtain cell protein, fuels and other chemicals. Xylanases combined with cellulase could have applications in food processing. Cellulase-free xylanases can be also utilized for preparation of cellulose pulps and liberation of textile fibres (WOODWARD 1984; BIELY 1985, WONG et al. 1988). In view of the potential applications of xylanases, a study of these enzymes from various sources and their multiplicity is desirable.Among xylanolytic microorganisms, filamentous fungi have been more extensively studied and the genus Aspergillus has been shown to be an efficient producer of xylanases. Preliminary observations from our laboratory have demonstrated that a strain of Aspergillus versicolor, isolated from Brazilian soil, produced high xylanase and low cellulase levels, which is an interesting characteristic for some industrial applications. In this report we describe the production and some properties of xylanase obtained from this fungus.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)