117,441 research outputs found
Contribution of NK3 tachykinin receptors to propulsion in the rabbit isolated distal colon
No full textThe role of NK3 receptors in rabbit colonic propulsion has been investigated in vitro with the selective agonist, senktide, and two selective antagonists, SR142801 and SB222200. Peristalsis was elicited by distending a rubber balloon with 0.3 and 1.0 mL of water leading to a velocity of 2.2 and 2.8 mm s(-1), respectively. At concentrations of 1 nM, senktide inhibited propulsion evoked by both distensions (range 25-40%), whereas at 6 and 60 nmol L-1 facilitated 'submaximal' propulsion by 30%. In the presence of N omega -nitro-L-arginine (L-NNA, 200 mu mol L-1), which per se caused a slight prokinetic effect, 1 nmol L-1 senktide markedly accelerated propulsion (range 35-50%). Hexamethonium (200 mu mol L-1) had minor effects on propulsion. In its presence, 60 nmol L-1 senktide significantly inhibited propulsion induced by both stimuli (range 20-50%). SR142801 (0.3, 3 nmol L-1) and SB222200 (30, 300 nmol L-1) facilitated 'submaximal' propulsion (range 20-40%). Conversely, higher antagonist concentrations (SR142801: 30, 300 nM; SB222200: 1, 10 mu mol L-1) inhibited propulsion to both distensions by 20%. A combination of SR142801 (300 nmol L-1) plus hexamethonium (200 mu mol L-1) induced an approximately four-fold greater inhibition of propulsion than that induced by SR142801 alone. In conclusion, in the rabbit-isolated distal colon, a subset of NK3 receptors located on descending pathways mediates an inhibitory effect on propulsion by activating a NO-dependent mechanism. Another subset of NK3 receptors, located on ascen ding pathways mediates a facilitative effect involving a synergistic interaction with cholinergic nicotinic receptors
Pesca artesanal na Baía Norte de Florianópolis: capturas, esforço de pesca, problemática e possíveis soluções.
No full textTCC(graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Biológicas. Biologia.A Baía Norte de Florianópolis se localiza no litoral central do Estado de Santa Catarina (27° 23 ' - 27° 25S, 48° 33 ' - 48° 30'O) e se caracteriza como um ambiente estuarino de alta produtividade. É uma região utilizada por diversas espécies que se encontram em período reprodutivo e abriga espécies ameaçadas de extinção como a tartaruga Chelonia mydas e uma população residente de golfinhos da espécie Sotalia guianensis. Acompanhamos o trabalho de 8 pescadores, distribuídos em diferentes comunidades pesqueiras da ilha de Santa Catarina e do continente (Sambaqui, Saco Grande, Caieira e Fazenda da Armação), com o objetivo geral de analisar a pesca artesanal nessa região com ênfase nas capturas, esforço de pesca, problemática da atividade e possíveis soluções. Através de saídas embarcadas e entrevistas realizadas no período de junho de 2006 até junho de 2008, buscamos conhecer a estrutura organizacional das instituições envolvidas na pesca artesanal, as características sócioeconômicas e operacionais dos pescadores, o esforço pesqueiro aplicado à Baía Norte, sua produção pesqueira e o comportamento destes em relação a ocupação do espaço e otimização dos processos pesqueiros. A Captura por Unidade de Esforço (CPUE) foi utilizada para as análises da produção pesqueira. Através da teoria de forrageamento ótimo, buscamos identificar o comportamento e a percepção dos pescadores em relação às estratégias de pesca e sua otimização. Após consultas a diversas instituições governamentais e não governamentais, verificamos que o governo terceirizou serviços administrativos ligados a pesca e os custos foram repassados aos pescadores artesanais. Entrevistas com 43 pescadores mostraram que a idade média é de 41 anos (d.p.=12,67 anos) e estes começam a pescar com idades entre 7 e 12 anos. Possuem em média 1,53 filhos (d.p.=1,35 filhos) e renda variando entre 1 e 3 salários mínimos (média de R$522,49 e d.p.=226,89). Porém, a variação desta renda é grande e 65% dos pescadores analisados possuem outra fonte de renda. Identificamos junto a SEAP/PR 156 embarcações (Bateiras, Botes e Baleeiras) atuando na Baía Norte e cerca de 500 pescadores artesanais executando as artes de pesca de Cerco, Caceio, Fundeio e Arrasto. Nas 52 saídas realizadas, acompanhamos a captura de 4912Kg de pescado, onde para isso foram utilizados um total de 581306m2 de rede durante 628 horas. O Caceio foi a arte mais executada, 58,18% das pescarias, o Arrasto a arte que apresentou a maior CPUE (642,52g/m2/hora), o Cerco a arte com a maior média de captura (105,91kg e d.p.=470,61kg) e o Fundeio a arte de pesca que capturou as espécies não-alvo mais ameaçadas. Na composição do pescado estão 34 espécies de peixes, 3 de crustáceos e 1 de réptil, sendo as principais espécies capturadas Litopenaeus schimitii, Trichiurus lepturus, Micropogonias furnieri, Mugil platanus. e Menticirrhus americanus. Entre as espécies não alvo capturadas estão 5 indivíduos de Chelonia mydas. Através da análise comportamental dos pescadores e a aplicação do modelo de forrageamento ótimo, verificamos que existe um revezamento de artes de pesca e uma forte relação entre a distância dos pontos de pesca e o tempo gasto nos processos pesqueiros. Assim, verificamos que os pescadores da Baía Norte possuem Raphael B. M. Aggio X um comportamento funcional e estratégico em busca de maiores capturas e, conseqüentemente, maior retorno financeiro. A crise na qual o setor pesqueiro mundial se encontra aumenta a importância da pesca artesanal como principal fonte de pescado e dependente de novas medidas conservacionistas. Além disso, estudos recentes deixam cada vez mais clara a interdependência entre diferentes ecossistemas, mostrando que os resultados locais podem e devem ser levados para o nível global. Sendo assim, os resultados apresentados neste estudo devem receber grande atenção dos órgãos competentes para o desenvolvimento de práticas conservacionistas participativas que solucionem a problemática aqui apresentada
Contribution of NK(2) tachykinin receptors to propulsion in the rabbit distal colon
No full textThe role of the tachykinin neurokinin (NK)(2) receptors on rabbit distal colon propulsion was investigated by using two selective NK(2)-receptor antagonists, MEN-10627 and SR-48968. Experiments on colonic circular muscle strips showed that contractile responses to [beta-Ala(8)]NKA-(4-10) (1 nM-1 microM), a selective NK(2)-receptor agonist, were competitively antagonized by MEN-10627 (1-100 nM), whereas SR-48968 (0.1-10 nM) caused an insurmountable antagonism, thus confirming the difference in the mode of action of the two compounds. Colonic propulsion was elicited by distending a mobile rubber balloon with 0.3 ml (submaximal stimulus) or 1.0 ml (maximal stimulus) of water. The velocity of anal displacement of the balloon (mm/s) was considered the main propulsion parameter. At low concentrations (1.0-100 nM and 0.1-10 nM, respectively), MEN-10627 and SR-48968 facilitated the velocity of propulsion, whereas at high concentrations (100 nM and 1 microM, respectively) they decelerated propulsion. The excitatory and inhibitory effects of both antagonists were observed only with submaximal stimulus. We focused on the hypothesis that the facilitatory effect on propulsion may result from blockade of neuronal NK(2) receptors and the inhibitory effect from suppression of the excitatory transmission mediated by NK(2) receptors on smooth muscle cells. In the presence of N(G)-nitro-L-arginine (300 microM), a nitric oxide synthase inhibitor, MEN-10627, at a concentration (10 nM) that was found to accelerate propulsion in control experiments inhibited the velocity of propulsion. In the presence of threshold (1-10 nM) or full (1 microM) concentration of atropine, which inhibited to a great extent the velocity of propulsion, the inhibitory effect of MEN-10627 (1 microM) was markedly increased. In conclusion, in the rabbit distal colon NK(2) receptors may decelerate propulsion by activating a nitric oxide-dependent neuronal mechanism and may accelerate it by a postjunctional synergistic interaction with cholinergic muscarinic receptor
A novel polymerase chain reaction (PCR) - Denaturing Gradient Gel Electrophoresis (DGGE) for the identification of Micrococcaceae strains involved in meat fermentations. Its application to naturally fermented Italian sausages
No full textnew molecular method consisting of polymerase chain reaction (PCR) amplification and denaturing gradient gel electrophoresis (DGGE) of a small fragment from the 16S rRNA gene identified the Micrococcaceae strains isolated from natural fermented Italian sausages. Lactic acid bacteria, total aerobic mesophilic flora, Enterobacteriaceae and faecal enterococci were also monitored. Micrococcaceaea control strains from international collections wereused to optimise the method and 90 strains, isolated from fermented sausages, were identified by biochemical tests and PCR-DGGE. No differences were observed between the methods used. The results reported in this paper provethat Staphylococcus xylosus is the main bacterium involved in fermented sausage production, representing, from the tenth day of ripening, the only Micrococcaceaea species isolated. (C) 2001 Elsevier Science Ltd. All rights reserved
Psychosomatic factors and peptic ulcer disease
No full textThe authors present a review of the role of psychological factors in peptic ulcer disease (PU). Three lines of research have been identified: - personality, psychological factors and PU; - stressful life events and their relationship to PU; - possible interactions between biological parameters, the CNS and psychosocial aspects. The analysis of the studies presented shows that there is a certain level of agreement with regard to personality and psychological aspects; PU patients present a personality with dependence/independence problems and high level of anxiety. Data concerning the role of stress appear to be far from unform and often even contradictory. Much remains to be done with respect to the possible links between psychological and biological parameters; there have been only few studies in man - which have not been duplicated and were performed on a limited number of patients - but a fair number in animals. However, the results concerning the relationship between psyche and secretory patterns are very interesting, and represent one of the most important lines of future research
An application of PCR-DGGE analysis to profile the yeast populations in raw milk
No full textFour different zones from the Friuli Venezia Giulia region, North East of Italy, were sampled for the study of the yeast biodiversity in raw milk. Samples were analysed by traditional methods to isolate different yeast strains that were subjected to identification by sequencing the D1-D2 domains of the 26S rRNA gene. Twelve different species of yeast were identified, six of them belonging to the genera Candida and two to the genera Kluyveromyces. The identified strains were then used for the optimization of a method based on polymerase chain reaction and denaturing gradient gel electrophoresis that was used for a direct monitoring of the populations in the samples. Applying the method to the DNA extracted directly from the raw milk samples, new bands appeared in the gel underlining a different bio-diversity in respect to the traditional method. The approach described is a powerful and reliable tool to monitor directly yeast ecology in milk and milk products without the need of traditional isolation and it could be used to follow specific populations to prevent spoilage or to control contamination. © 2002 Published by Elsevier Science Ltd
Studio dell’evoluzione della flora microbica durante la fermentazione di salami mediante l’impiego della tecnica elettroforetica DGGE (Denaturing Gradient Gel Electrophoresis)
No full textInterventi riabilitativi negli esordi psicotici e nelle popolazioni “a rischio” di psicosi
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