617 resultados para Polysaccharides


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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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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The aim of the present study was to characterize biopsied and stripped oocytes from the Brazilian endangered teleost pirapitinga (Brycon nattereri) using histochemical and morphological analyses. Biopsied oocytes had a mean diameter of 2.225 mm (modal diameter: 2.312 mm), complete vitellogenesis and a central or slightly eccentric nucleus. Neutral polysaccharides were detected in the follicular cells, zona radiata and yolk globules, while acidic polysaccharides were detected in the follicular cells and cortical alveoli. Ten out of the 19 females treated with two doses of carp pituitary extract (cPE) released oocytes, which were also analysed. Stripping occurred 292 +/- 39 degree-hours after the second dose of cPE and led to a mean spawning weight of 36.2 g, 10% spawning index, 241 oocytes/g of ova, 8222 oocytes/female and 23 oocytes/g of body weight. Stripped oocytes had a mean diameter of 2.33 mm and a mode at 2.375 mm, were weakly adhesive and coloration ranged from wine to brown. Under scanning electron microscopy, stripped oocytes exhibited a single funnel-shaped micropyle located at the animal pole and a zona radiata that measured 7.7 m in thickness with eight pore canals/m(2). Oocyte morphology in Brycon nattereri is similar to that found in other species of the genus, except for the larger size and weaker adhesiveness. These findings provide essential information for a better understanding of the reproductive biology of B. nattereri and the establishment of conservation measures for this threatened species.

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The effect of inulin and/or okara flour on Lactobacillus acidophilus La-5 and Bifidobacterium animalis Bb-12 viability in a fermented soy product (FSP) and on probiotic survival under in vitro simulated gastrointestinal conditions were investigated throughout 28 days of storage at 4 °C. Employing a 22 design, four FSP trials were produced from soymilk fermented with ABT-4 culture (La-5, Bb-12, and Streptococcus thermophilus): FSP (control); FSP-I (with inulin, 3 g/100 mL of soymilk); FSP-O (with okara, 5 g/100 mL); FSP-IO (with inulin + okara, ratio 3:5 g/100 mL). Probiotic viabilities ranged from 8 to 9 log cfu/g during the 28 days of storage, and inulin and/or okara flour did not affect the viability of La-5 and Bb-12. Bb-12 resistance to the artificial gastrointestinal juices was higher than for La-5, since the Bb-12 and La-5 populations decreased approximately 0.6 log cfu/g and 3.8 log cfu/g, respectively, throughout storage period. Even though the protective effect of inulin and/or okara flour on probiotic microorganisms was not significant, when compared to a fresh culture, the FSP matrix improved Bb-12 survival on day 1 of storage and may be considered a good vehicle for Bb-12 and could play an important role in probiotic protection against gastrointestinal juices. © 2013 Elsevier Ltd.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Microbiologia Agropecuária - FCAV

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The action of man has led, over the years, major impacts on the environment, especially in aquatic ecosystems, leading to an impairment of water quality, considered one of the essential factors for the maintenance of vital functions and consequently the life of the planet. Among the activities considered a risk for the environment are linked to pollution from many sources and even entire watersheds, whether by industrial waste, sewage, or for substances used in agriculture, such as pesticides, herbicides and fertilizers. The (2,4-D) 2,4- dichlorophenoxyacetic acid is used worldwide, and the fact that its genotoxicity is proven by several studies and by its long persistence in soil, which enables the leaching and percolation of compounds affecting water bodies, toxicity studies are relevant and justifiable. Thus, this study aimed to evaluate the toxicity of 2,4-D by examining the liver of the fish Oreochromis niloticus exposed to different dilutions. Portions of liver were collected and fixed for histological and histochemical techniques to detect total proteins, polysaccharides and lipids. lipids. Treatment with 2,4-D herbicide apparently did not alter the lipid profiles, the accumulation of polysaccharides, and the presence of total proteins. The 2.5 and 5.0% were lethal to fish. These mortalities are probably of high toxic and cytotoxic potential of 2,4-D herbicide results. Several histopathological changes were found, such as: loss of cytoplasmic integrity, loss of cell limit, nuclear deformation, vacuolated cytoplasm, tissue disorganization and hydropic degeneration. Statistically significant changes were: hydropic degeneration and vacuolated cytoplasm. It is concluded, therefore, that the qualitative morphological analysis is an important method for observing changes in liver toxicology studies. As the O. niloticus species is an efficient biological indicator of water pollution by 2,4-D

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The action of man has led, over the years, major impacts on the environment, especially in aquatic ecosystems, leading to an impairment of water quality, considered one of the essential factors for the maintenance of vital functions and consequently the life of the planet. Among the activities considered a risk for the environment are linked to pollution from many sources and even entire watersheds, whether by industrial waste, sewage, or for substances used in agriculture, such as pesticides, herbicides and fertilizers. The (2,4-D) 2,4- dichlorophenoxyacetic acid is used worldwide, and the fact that its genotoxicity is proven by several studies and by its long persistence in soil, which enables the leaching and percolation of compounds affecting water bodies, toxicity studies are relevant and justifiable. Thus, this study aimed to evaluate the toxicity of 2,4-D by examining the liver of the fish Oreochromis niloticus exposed to different dilutions. Portions of liver were collected and fixed for histological and histochemical techniques to detect total proteins, polysaccharides and lipids. lipids. Treatment with 2,4-D herbicide apparently did not alter the lipid profiles, the accumulation of polysaccharides, and the presence of total proteins. The 2.5 and 5.0% were lethal to fish. These mortalities are probably of high toxic and cytotoxic potential of 2,4-D herbicide results. Several histopathological changes were found, such as: loss of cytoplasmic integrity, loss of cell limit, nuclear deformation, vacuolated cytoplasm, tissue disorganization and hydropic degeneration. Statistically significant changes were: hydropic degeneration and vacuolated cytoplasm. It is concluded, therefore, that the qualitative morphological analysis is an important method for observing changes in liver toxicology studies. As the O. niloticus species is an efficient biological indicator of water pollution by 2,4-D

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Previous studies have shown that heparin induces vascular relaxation via integrin-dependent nitric oxide (NO)-mediated activation of the muscarinic receptor. The aim of this study was to identify the structural features of heparin that are necessary for the induction of vasodilatation. To address this issue, we tested heparin from various sources for their vasodilatation activities in the rat aorta ring. Structural and chemical characteristics of heparin, such as its molecular weight and substitution pattern, did not show a direct correlation with the vasodilation activity. Principal component analysis (PCA) of circular dichroism (CD), 1H-nuclear magnetic resonance (NMR) and vasodilation activity measurements confirmed that there is no direct relationship between the physico-chemical nature and vasodilation activity of the tested heparin samples. To further understand these observations, unfractionated heparin (UFH) from bovine intestinal mucosa, which showed the highest relaxation effect, was chemically modified. Interestingly, non-specific O- and N-desulfation of heparin reduced its anticoagulant, antithrombotic, and antihemostatic activities, but had no effect on its ability to induce vasodilation. On the other hand, chemical reduction of the carboxyl groups abolished heparin-induced vasodilation and reduced the affinity of heparin toward the extracellular matrix (ECM). In addition, dextran and dextran sulfate (linear non-sulfated and highly sulfated polysaccharides, respectively) did not induce significant relaxation, showing that the vasodilation activity of polysaccharides is neither charge-dependent nor backbone unspecific. Our results suggest that desulfated heparin molecules may be used as vasoactive agents due to their low side effects. J. Cell. Biochem. 113: 13591367, 2012. (c) 2011 Wiley Periodicals, Inc.

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Calcium carbonate is one of the most important biominerals, and it is the main constituent of pearls, seashells, and teeth. The in vitro crystallization of calcium carbonate using different organic matrices as templates has been reported. In this work, the growth of calcium carbonate thin films on special organic matrices consisting of layer-by-layer (LbL) polyelectrolyte films deposited on a pre-formed phospholipid Langmuir-Blodgett (LB) film has been studied. Two types of randomly coiled polyelectrolytes have been used: lambda-carrageenan and poly(acrylic acid). A precoating comprised of LB films has been prepared by employing a negatively charged phospholipid, the sodium salt of dimyristoilphosphatidyl acid (DMPA), or a zwitterionic phospholipid, namely dimyristoilphosphatidylethanolamine (DMPE). This approach resulted in the formation of particulate calcium carbonate continuous films with different morphologies, particle sizes, and roughness, as revealed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The crystalline structure of the calcium carbonate particles was analyzed by Raman spectroscopy. The randomly coiled conformation of the polyelectrolytes seems to be the main reason for the formation of continuous films rather than CaCO3 isolated crystals. (C) 2012 Elsevier B.V. All rights reserved.