601 resultados para mamíferos


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The occurrence of bioactive compounds in marine organisms comes awaking the interest of the pharmaceutical industry. Heparin, a sulfated polysaccharide which presence was already identified in several marine invertebrates, is very attractive due its remarkable functional versatility. Besides to intervene in blood coagulation, this molecule has a great anti-inflammatory potential. However, its strong anticoagulant activity difficult the clinical exploitation of its anti-inflammatory properties. Thus, the aims of this work were to evaluate the effect of a heparin-like compound (heparinoid), isolated from the cephalotorax of the Litopenaeus vannamei shrimp, on the inflammatory response, hemostasia and synthesis of antithrombotic heparan sulfate by endothelial cells, besides studying some aspects concerning its structure. The purified heparinoid was structurally characterized following an analytical boarding, involving electrophoresis and chromatography. The structural analysis have shown that this compound possess a high content of glucuronic acid residues and disulfated disaccharide units. In contrast to mammalian heparin, the heparinoid was incapable to stimulate the synthesis of heparan sulfate by endothelial cells in the tested concentrations, beyond to show reduced anticoagulant activity and hemorrhagic effect. In a model of acute inflammation, the compound isolated from the shrimp reduced more than 50% of the cellular infiltration. Besides reduce the activity of MMP-9 and proMMP-2 of the peritoneal lavage of inflamed animals, the heparinoid also reduced the activity of MMP-9 secreted by activated human leukocytes. These results demonstrate the potential of heparinoid from L. vannamei to intervene in the inflammatory response. For possessing reduced anticoagulant activity and hemorrhagic effect, this compound can serve as a structural model to direct the development of more specific therapeutical agents to the treatment of inflammatory diseases

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Linseed is an important oilseed consumed raw as nutritional supplement, that although represents a rich source of nutrients, its nutritional value could be impaired due to the presence of antinutritional factors. In this study, protein fractions from raw linseed flour were extracted and isolated being obtained 12% of albumins, 82% of globulins, 5% of glutelins and 1% of prolamins. These proteins were visualized by SDS-PAGE and albumins showed low molecular mass protein bands around 21 kDa and minor bands, similar to that of trypsin inhibitor; Globulins presented protein bands with high molecular masses, which possibly are constituents of multimeric proteins, such as legumins. After determination of the centesimal composition of raw linseed, it was used as exclusive protein source for young rats to evaluate its effect on animal growth. The results showed negative effects on rat growth (weight gain 73% less than the control group) and reduction of intestinal villus (35%), that could be related with in vitro and in vivo globulin digestibility and proteinaceous antinutritional factors (mammalian digestive enzymes inhibitors and lectins) in albumin fraction. Native globulins showed, by SDS-PAGE, low susceptibility in vitro to trypsin and chymotrypsin, however presented high degradation by pancreatin. Thermal treatment of globulins for 5 and 15 minutes at 100ºC improved considerably its digestibility by trypsin and pancreatin. Globulins presented 93.2% in vivo digestibility, similar to the control protein. Albumin fraction had high trypsin inhibition activity (100%) and chymotrypsin inhibition of 28.3%; haemagglutinating activity was not detected. The results of this study indicate the negative action of trypsin inhibitors on animal growth, but can not be discarded its combined action with other antinutritional factors, which could compromise the raw linseed utilization as an alternative food

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Proteinases are enzymes distributed widely founded in several organisms and perform many different functions, from maintaining homeostasis to the worsening of some diseases such as cancer, autoimmune diseases and infections. The proteins responsible of controlling the action of these enzymes are the inhibitors, that are classified based on their target proteases and are founded since simple organisms, such as bacteria, to higher organisms, such as larger plants and mammals. Plant proteinase inhibitors act by reducing or inactivating the activity of target proteases, thus, these proteins have been studied as potential tools in the treatment of diseases related to protease activities. In this context, an inhibitor of chymotrypsin from Erythrina velutina, called EvCI was previously purified and it was observed that this protein plays in vitro anticoagulant activity and anti-inflammatory activity in in vivo model. Aiming to reduce the environmental impact caused by the purification EvCI in high amounts and to facilitate the process of obtaining this protein, the recombinant chymotrypsin inhibitor from Eryhrina velutina was produced after cloning and expression in Escherichia coli. The bacteria were grown in LB medium and after induction of the expression this material was subjected to procedures for cell lysis and the product was applied on Nickel-affinity column. The proteins adsorbed were digested by thrombin and applied on Chymotrypsin-Sepharose affinity column, obtaining the purified inhibitor, named recEvCI. After electrophoresis, the recombinant inhibitor showed an approximately molecular mass of 17 kDa, and reduced the chymotrypsin and elastase activities in vitro. The recombinant inhibitor was sequenced and was found similar amino acids residues when compared to other inhibitors deposited in the database, with some modifications. recEvCI showed high stability under pH variations and reducing conditions, maintaining its activity around 80%. This protein increased the blood coagulation time in vitro by acting on the intrinsic pathway and did not show cytotoxicity against strains of mouse 3T3 fibroblasts and RAW 264.7 macrophages. recEvCI showed microbicide activity related to release of nitric oxide and consequently the activation of macrophages, futhermore having proinflammatory effects assessed by increased release of TNF-α. These results indicate that recEvCI can be biotechnologically used as a new tool in the control of coagulation-related diseases as well as can be an activating agent of the immune system in immunosuppressed individuals

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This report shows 2232 times purification of a βNAcetylhexosaminidase from hepatic extracts from the sea mammal Sotalia fluviatilis homogenate with final recovery of 8,4%. Sequenced steps were utilized for enzyme purification: ammonium sulfate fractionation, Biogel A 1.5 m, chitin, DEAESepharose and hydroxyapatite chromatographies. The protein molecular mass was estimated in 10 kDa using SDSPAGE and confirmed by MALDITOF. It was found to have an optimal pH of 5.0 and a temperature of 60°C. Using pnitrophenylNAcetylβDglycosaminide apparent Km and Vmax values were of 2.72 mM and 0.572 nmol/mg/min, respectively. The enzyme was inhibited by mercury chloride (HgCl2) and sodium dodecil sulfate (SDS)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Human Papillomavirus (HPV) infection is the major sexually transmitted disease all over the world. There are many factors associated to infection and the virus persistency in the organism. This study aims to evaluate the women's knowledge, attitudes and practice about the Papanicolaou test (Pap), as well as analyze the HPV and Chlamydia trachomatis infections prevalences in sexually active women from the city of São José do Mipibu/RN/Brazil. This research was divided in two steps (step I and step II), using different methodologies and samples each. The samples collected in each step, even socio-demographic or from uterus cervix, are from different patients e were analyzed separated. In step I was evaluated 267 rural and urban zone women s knowledge, attitudes and practices about the Pap by home interview. In the step II were included 605 women with age ranged from 15 to 71 years old, with mean of 33,5 years old and from each one were collected two cervical samples, one for Pap and other for molecular biology, beside the epidemiological interview to investigate the correlation between prevalence of HPV infection and risk factors. To molecular analyses, the samples were processed using a mammal rapid DNA extraction technique protocol. For C. trachomatis DNA detection were used the CP24/27 primers, and GP5+/GP6+ to HPV. PCR products were analyzed by electrophoresis on 8% polyacrylamide gels, followed by silver staining. The results of the step I showed that, in spite of only 46,1% of the interviewed women they have demonstrated to possess appropriate knowledge on the Pap test, the attitude and practice proportions were significantly larger, 63,3% and 64,4% respectively. The largest education degree presented association with adaptation of the knowledge, attitudes and practice, while neglect, lack of solicitation of the exam for the doctor and shame, came as main barriers for the accomplishment of the exam. In the stage II the HPV general prevalence was 28,9%, being 26,7% in the women with normal cytology or benign alterations, 26,7% in the ones that had atypical squamous cells of undetermined significance (ASC-US) and 80% in those with Low grade squamous intraepithelial lesion (LSIL). the HPV infection prevalence was larger in the patients with up to 30 years of age and in the unmarried women, and those that had more than one sexual partner presented larger infection risk. The results show that the sexual relationship with multiple partners increased the infection risk for HPV and consequently the possibility of the occurrence of lesions uterine cervix

Relevância:

10.00% 10.00%

Publicador:

Resumo:

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

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O Óxido Nítrico (ON) é gerado por uma família de isoenzimas, através da catálise enzimática do aminoácido essencial L-arginina, que resulta na formação de L-citrulina e ON. O on está envolvido em muitos processos fisiológicos dos mamíferos, que incluem a neurotransmissão, controle da pressão sangüínea, inflamação, reações imunológicas e nos mecanismos de defesa contra microorganisnos e tumores. O descontrole na síntese de on está implicado na patogênese de doenças cardiovasculares, autoimunidade, rejeição de transplantes, doenças degenerativas, na sépsis, na genotoxicidade e no surgimento de neoplasias. O on também foi incriminado como agente de iniciação da carcinogênese, que, associado a outros fatores, poderia levar ao descontrole da citoestase e da diferenciação celular. A diversidade de efeitos do on parece estar relacionada às concentrações de on gerados, à sensibilidade individual das células e à duração do fenômeno.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Muitos países subdesenvolvidos são caracterizados por uma significativa diversidade sociocultural e por uma acentuada pobreza em grande parte da população, que fazem uso da caça de animais como uma fonte alternativa de alimento e para outros fins. O estudo objetivou investigar se a distância das populações humanas da zona rural em relação à zona urbana e fatores socioeconômicos podem ser preditores de um maior conhecimento sobre as espécies da fauna utilizadas. Além disso, o estudo objetivou também testar uma ferramenta capaz de gerar uma lista da fauna prioritária para a conservação local a partir do conhecimento local. Os dados foram coletados por meio de 30 entrevistas utilizando formulários semi-estruturados em quatro comunidades rurais no município de Pedro Avelino, RN. Foram calculados o fator de consenso dos informantes (ICF), a importância relativa (IR) e o nível de fidelidade (FL). Adicionalmente, foi calculado o índice de Shannon-Wiener para as categorias de uso: estimação, alimentar, medicinal e para a multiplicidade de uso por informante. Os entrevistados reconhecem 83 espécies pertencentes a 45 famílias de animais. As espécies citadas pertencem a seis grandes grupos taxonômicos: aves, mamíferos, répteis, anfíbios, peixes e insetos. O conhecimento sobre a utilização de animais para as categorias de uso definidas neste trabalho não mostrou relação significativa com os fatores socioeconômicos e nem com a distância das comunidades da zona rural para a zona urbana de Pedro Avelino. Os resultados sugerem, portanto, que a pobreza nivela o conhecimento sobre o uso da fauna independente da distância que as comunidades encontram-se da zona urbana. As listas geradas permitirão direcionar estudos ecológicos mais aprofundados visando à conservação das espécies do bioma Caatinga. Desta forma, é importante considerar as interações existentes entre as pessoas e os animais para melhor entender a dinâmica de utilização e fornecer, assim, subsídios para a conservação das espécies.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O monitoramento endócrino pela mensuração de metabólitos urinários e fecais de hormônios esteróides tem se mostrado uma alternativa viável na investigação da fisiologia reprodutiva e do estresse em uma grande variedade de aves e mamíferos, domésticos e selvagens. Esta abordagem tem contribuído para uma maior integração da endocrinologia com estudos comportamentais e ecológicos, gerando informações mais detalhadas em diversas áreas tais como bem-estar animal, comportamento social, reprodução, biologia da conservação, biomedicina, entre outros. Todavia, o emprego desta metodologia no Brasil tem sido limitado principalmente à pesquisa de parâmetros reprodutivos e de estresse em espécies selvagens, não havendo até o momento trabalhos publicados utilizando a quantificação urinária ou fecal de glucocorticóides ou esteróides sexuais em animais domésticos. Desta forma, esta palestra tem como objetivo ilustrar alguns exemplos de estudos conduzidos no país envolvendo técnicas de monitoramento endócrino não-invasivo, assim como expor possíveis áreas de aplicação desta ferramenta em pesquisas com espécies domesticas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

O mercado demanda, desde final da década de 20, uma tecnologia para a sexagem de espermatozóides que possa ser inserida na indústria de produção de sêmen congelado e que tenha as seguintes características: a) não altere a viabilidade espermática; b) seja compatível com a congelação do espermatozóide sexado; c) permita a sexagem de espermatozóides previamente congelados e descongelados; d) permita a produção de várias doses de sêmen sexado congelado por dia, com custo compatível ao mercado. A importância dessa tecnologia para maximizar a produção animal a um custo baixo tem sido um desafio da pesquisa a vários anos. A possibilidade de produzir, em escala comercial, doses de sêmen enriquecidas com espermatozóides X ou Y aumentará os benefícios do uso da inseminação artificial no seu papel de maximizar o progresso genético entre gerações de acordo com os requerimentos de cada programa de melhoramento animal. Diferentes rotas tecnológicas são percorridas na tentativa de selecionar-se o sexo em mamíferos, tanto nas espécies de interesse zootécnico quanto em espécies ameaçadas de extinção, animais de companhia. Neste sentido, existem duas alternativas: a separação de espermatozóides portadores do cromossomo X, daqueles portadores do cromossomo Y; ou a sexagem de embriões pré-implantados. A viabilidade da sexagem de espermatozóides em bovinos é esperada por muitos anos e os desenvolvimentos recentes tornaram essa tecnologia de aplicação commercial. Entretanto, muitas limitações ainda existem, principalmente, referente à taxa de gestação em condições de campo. Isso restringe a utilização dessa tecnologia no melhoramento genético e produção animal. Nessa palestra abordaremos os potenciais sistemas de criação e produção que poderão beneficiar-se com a sexagem de espermatozóides, quando essas limitações forem solucionadas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

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

Relevância:

10.00% 10.00%

Publicador:

Resumo:

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

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The cerebral cortex of mammals is histologically organized into different layers of excitatory neurons that have distinct patterns of connections with cortical or subcortical targets. During development, these cortical layers are established through an intricate combination of neuronal specification and migration in a radial pattern known as "insideout": deep-layer neurons are generated prior to upper-layer neurons. In the last few decades, several genes encoding transcription factors involved in the sequential specification of neurons destined to different cortical layers have been identified. However, the influence of early-generated neurons in the specification of subsequent neuronal cohorts remains unclear. To investigate this possible influence, we induced the selective death of cortical neurons from layer V and VI before the generation of layer II, III and IV neurons. Thus, we can evaluate the effects of ablation of early born neurons on the phenotype of late born neurons. Our data shows that one-day after ablation, layer VI neurons expressing the transcription factor TBR1 are newly generated while virtually no neuron expressing TBR1 was generated in the same age in control animals. This suggests that progenitors involved in the generation of neurons destined for superficial layers suffer interference from the selective death of neurons in deep layers, changing their specification. We also observed that while TBR1-positive neurons are located exclusively in deep cortical layers of control animals, many TBR1-positive neurons are misplaced in superficial layers of ablated animals, suggesting that the migration of cortical neurons could be controlled independently of neuronal phenotypes. Furthermore, we observed an increase in layer V neurons expressing CTIP2 and neurons expressing SATB2 and that these cells have changed their distributions. As a conclusion, our data indicate the existence of a mechanism of control exercised by the early-generated neurons in the cerebral cortex on the fate of the progenitors involved in the generation of the following cortical neurons. This mechanism could help to control the number of neurons in different layers and contribute to the establishment of different cortical areas

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The use of non-human primates in scientific research has contributed significantly to the biomedical area and, in the case of Callithrix jacchus, has provided important evidence on physiological mechanisms that help explain its biology, making the species a valuable experimental model in different pathologies. However, raising non-human primates in captivity for long periods of time is accompanied by behavioral disorders and chronic diseases, as well as progressive weight loss in most of the animals. The Primatology Center of the Universidade Federal do Rio Grande do Norte (UFRN) has housed a colony of C. jacchus for nearly 30 years and during this period these animals have been weighed systematically to detect possible alterations in their clinical conditions. This procedure has generated a volume of data on the weight of animals at different age ranges. These data are of great importance in the study of this variable from different perspectives. Accordingly, this paper presents three studies using weight data collected over 15 years (1985-2000) as a way of verifying the health status and development of the animals. The first study produced the first article, which describes the histopathological findings of animals with probable diagnosis of permanent wasting marmoset syndrome (WMS). All the animals were carriers of trematode parasites (Platynosomum spp) and had obstruction in the hepatobiliary system; it is suggested that this agent is one of the etiological factors of the syndrome. In the second article, the analysis focused on comparing environmental profile and cortisol levels between the animals with normal weight curve evolution and those with WMS. We observed a marked decrease in locomotion, increased use of lower cage extracts and hypocortisolemia. The latter is likely associated to an adaptation of the mechanisms that make up the hypothalamus-hypophysis-adrenal axis, as observed in other mammals under conditions of chronic malnutrition. Finally, in the third study, the animals with weight alterations were excluded from the sample and, using computational tools (K-means and SOM) in a non-supervised way, we suggest found new ontogenetic development classes for C. jacchus. These were redimensioned from five to eight classes: infant I, infant II, infant III, juvenile I, juvenile II, sub-adult, young adult and elderly adult, in order to provide a more suitable classification for more detailed studies that require better control over the animal development

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this study, two circadian related centres, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) were evaluated in respect to their cytoarchitecture, retinal afferents and chemical content of major cells and axon terminals with a tract tracer and immunohistochemical techniques in the rock cavy (Kerodon rupestris), a Brazilian caviidae rodent species. The rock cavy SCN is innervated in its ventral portion by terminals from the predominantly contralateral retina. It also contains neurophisin and vasoactive intestinal polypeptide immunoreactive cell bodies and neuropeptide Y and enkephalin immunopositive fibres and terminals and is marked by intense GFAP immunoreactivity. The IGL receives a predominantly contralateral retinal projection, contains neuropeptide Y and nitric oxide synthase producing neurons and enkephalin immunopositive terminals and is characterized by dense GFAP immunoreactivity. This is the first report examining the neural circadian system in a crepuscular rodent species for which circadian properties have been described. The results are discussed comparing with what has been described for other species and in the context of the functional significance of these centres