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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
721

AVALIAÇÃO DO EFEITO COMPORTAMENTAL E NEUROPROTETOR DO ÔMEGA-3 ADMINISTRADO DURANTE O PERÍODO PRÉ-NATAL EM UM MODELO ANIMAL DA DOENÇA DE PARKINSON.

Pochapski, José Augusto 22 February 2016 (has links)
Made available in DSpace on 2017-07-21T14:35:54Z (GMT). No. of bitstreams: 1 JOSE AUGUSTO POCHAPSKI.pdf: 2266023 bytes, checksum: e6666fece9c726545eef3a5015509386 (MD5) Previous issue date: 2016-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Parkinson's disease (PD) is the second most common neurodegenerative disease in the world population. However, its current treatment comes down to symptomatic relief. The omega-3 (-3) being an essential fatty acid for brain development, has been showing beneficial effects in PD. Therefore, the aim of this study was to evaluate whether treatment with -3 during early neurodevelopment periods provides a nootropic, antidepressant and/or neuroprotective effect in an animal model of PD. For this, female rats were treated with -3 during pregnancy (150, 300, 600 mg/Kg/day) and during pregnancy + lactation (300 mg/Kg /day). After completing two months of age the male offspring were submitted to the tests of sucrose preference, social recognition, object recognition and open field. Completing three months of age, the animals received in the prosencefalic unilateral 6-OHDA infusion and subsequent test of the rotational behavior or bilateral 6-OHDA infusion and subsequent tests of sucrose preference, social recognition and open field. A nootropic effect of -3 was observed from the results obtained on the tests of social recognition (-3 600) and object recognition (all groups -3). Regarding the animal model of PD, the -3 (all -3 groups) showed a reduction of the cognitive deficits induced by 6-OHDA, but without na antidepressive effect, although there was no demonstration of neuroprotection after unilateral lesion with 6-OHDA. Thus, this study the -3 demonstrated an nootropic and a possible neuroprotective effect of the -3 administration during the pregnancy period. / A doença de Parkinson (DP) é a segunda doença neurodegenerativa mais comum na população mundial, entretanto, seu atual tratamento resume-se a alívios sintomáticos. O ômega-3 (-3) sendo um ácido graxo essencial no neurodesenvolvimento, também vem apresentando efeitos benéficos na DP. Assim sendo, o objetivo deste trabalho foi avaliar se o tratamento com -3 durante os períodos iniciais do neurodesenvolvimento proporciona um efeito nootrópico, antidepressivo e/ou neuroprotetor em um modelo animal da DP. Para isso, ratas foram tratadas com -3 durante a gestação (150 ou 300 ou 600 mg/Kg/dia) e durante a gestação+lactação (300 mg/Kg/dia). Após terem completado dois meses de idade, os filhotes machos foram submetidos aos testes de preferência à sacarose, reconhecimento social, reconhecimento de objetos e campo aberto. Completando 3 meses de idade, estes animais receberam no feixe prosencefálico medial infusão unilateral de 6-OHDA e posterior teste do comportamento rotatório ou infusão bilateral de 6-OHDA e subsequentes testes de preferência à sacarose, reconhecimento social e campo aberto. Foi observado um efeito nootrópico do -3 a partir dos resultados obtidos aos dois meses nos testes de reconhecimento social (-3 600mg/Kg) e reconhecimento de objetos (todos grupos -3). Em relação ao modelo animal da DP, o tratamento com -3 (todos os grupos ω-3) reduziu os prejuízos cognitivos induzidos pela 6-OHDA, porém sem apresentar efeito antidepressivo nestes,além de não reduzir o número de rotações contralaterais após a lesão unilateral com a 6-OHDA. Com isso, demonstramos neste trabalho um efeito nootrópico e,possivelmente neuroprotetor, da administração do -3 durante o período da gestação. Palavras chave: Ômega-3. Neurodesenvolvimento. Doença de Parkinson.
722

Modelo para segmentação por benefícios de consumidores bancários pessoas físicas: uma aplicação em São Paulo – SP / Model of segmentation of individual banking consumers using customer desired benefits: a study in São Paulo – SP

Moura, Mauricio Costa de 29 September 2005 (has links)
O presente estudo desenvolve e testa um modelo de segmentação por benefícios de consumidores bancários pessoas físicas. Para isso, investiga os atributos determinantes na escolha de bancos múltiplos para a abertura de novas contas-corrente a partir de uma extensa revisão da literatura sobre o tema. A identificação da determinância dos atributos no modelo é feita pela combinação entre a importância do atributo ao respondente e seu grau de diferenciação percebida entre as ofertas de mercado. A metodologia de pesquisa utilizada na aplicação do modelo tem por base uma abordagem quantitativa de levantamento de dados primários junto a uma amostra não-probabilística de clientes bancários da cidade de São Paulo. A análise de dados prevista no modelo e aplicada à pesquisa utiliza a técnica estatística de Análise Fatorial para reduzir o conjunto de atributos de pesquisa a fatores representativos dos benefícios procurados, seguida de Análises de Conglomerados dos tipos hierárquica e K-Means para agrupar os respondentes em relação aos benefícios procurados e às suas características demográficas. Conforme considerado no modelo, devido à impossibilidade de caracterização demográfica direta dos integrantes dos segmentos por benefícios, a análise estatística dos dados da pesquisa resulta finalmente em segmentos de 1a e 2a ordem do tipo post hoc e a priori, respectivamente. As considerações finais do estudo validam o modelo proposto à luz dos objetivos estabelecidos e dos requisitos geralmente aceitos para um processo de segmentação eficaz e conclui por sua aplicabilidade e sua utilidade aos profissionais de marketing de instituições financeiras e aos membros da Academia. / This study develops and tests a model of segmentation of individual banking consumers using customer desired benefits. For that purpose, it first investigates the determinant attributes used by individuals when choosing a commercial bank to open a new current account, from an extensive review of literature on the subject. The identification of the determinance of the attributes in the model is obtained from a combination of its perceived importance and its degree of differentiation perceived among market offers. The research methodology used in the application of the model uses a quantitative approach based on a collection of primary data within a non-probabilistic sample of banking customers in São Paulo. The analysis of data foreseen in the model and applied to this research uses the statistical technique of Factor Analysis to reduce the set of researched attributes to factors that stand for desired benefits, followed by Hierarquical and K-Means Cluster Analysis to group the respondents in terms of benefits and demography. As considered in the model, due to impossibility of direct demographic description of respondents within benefit segments, the analysis of data finally results in segments of 1st and 2nd order, a priori and post hoc respectively. The final study analysis validates the model in the light of its objectives and the generally accepted requirements for an efficient segmentation process and concludes for its applicability and utility to marketing practitioners of financial sector and to the Academy members.
723

Detecção molecular de Ranavirus em espécies de anfíbios anuros selvagens da região centro-leste do estado de São Paulo / Molecular detection of Ranavirus in wild anuran species of the central-eastern region of the state of São Paulo

Reis, Marcelo Felisberto dos 01 March 2018 (has links)
O objetivo do trabalho foi realizar investigação sobre ocorrência de ranavirose, infecção causada por vírus do gênero Ranavirus, família Iridoviridiae, em anfíbios anuros silvestres nos municípios de Porto Ferreira e Pirassununga, cidades da região centro-leste do estado de São Paulo, Brasil, utilizando diagnóstico molecular. Ao todo, 40 anuros adultos silvestres da espécie Leptodactylus fuscus foram capturados nos municípios citados, sendo coletados três órgãos alvos (fígado, baço e rins) de replicação viral, com registro de eventuais alterações macroscópicas nesses órgãos, e dos quais extraiu-se DNA. Na sequência, realizou a reação em cadeia pela polimerase (PCR), utilizando-se primers específicos para o gene MCP (major capsid protein) de Frog Virus 3 (FV3), ranavírus circulante no Brasil, com isolado de FV3 pertencente ao biobanco do Laboratório de Higiene Zootécnica da FZEA-USP empregado como controle positivo e água livre de nuclease como controle negativo. Como resultados, em relação às alterações macroscópicas, somente um espécime apresentou hepatoesplenomegalia e hipopigmentação do coração. No entanto, ao diagnóstico molecular, nenhum dos 40 animais amostrados foi positivo à ranavirose. Tal resultado pode estar associado tanto a fatores intrínsecos (espécie, idade, resposta imune) como extrínsecos ao hospedeiro (alterações ambientais, patogenicidade viral). Em paralelo, em rãs de criação comercial, surtos por FV3 já foram detectados em vários ranários do país; contudo, essa é a primeira vez que uma prospecção para ranavirose é realizada especificamente com representantes da espécie Leptodactylus fuscus, em municípios da região centro-leste do estado de São Paulo. Assim, são necessárias mais pesquisas com espécies silvestres de rãs, particularmente no entorno de ranários com histórico de animais positivos para FV3, para melhor conhecimento da epidemiologia e dinâmica de transmissão da ranavirose entre rãs silvestres. / The objective of this study was to investigate the occurrence of ranavirus infection caused by virus belonging to genus Ranavirus, Iridoviridiae family, in wild anuran amphibians from Porto Ferreira and Pirassununga municipalities, located in the central-eastern region of the state of São Paulo, Brazil, using molecular diagnostics. In all, 40 wild adult anurans of the species Leptodactylus fuscus were captured in the mentioned municipalities, and three target organs (liver, spleen and kidneys) of the viral replication were collected, being possible macroscopic changes in these organs recorded, and from which DNA was extracted. In the sequence, the polymerase chain reaction (PCR) was carried out using primers specific for the MCP (major capsid protein) gene of Frog Virus 3 (FV3), a circulating ranavirus in Brazil, with a FV3 isolate belonging to the biobank of the Laboratory of Zootechnical Hygiene of FZEA-USP employed as positive control and nuclease-free water as negative control. As a result, in relation to macroscopic alterations, only one specimen showed hepatosplenomegaly and heart hypopigmentation. However, for molecular diagnostics, none of the 40 animals sampled were positive for ranavirus. This result may be associated to both intrinsic (species, age, immune response) and extrinsic (environmental changes, viral pathogenicity) factors to the host. In parallel, FV3 outbreaks have already been detected in several frog farms in the country. However, this is the first time that a prospection for ranavirus infection is performed specifically with specimens of the Leptodactylus fuscus from municipalities in the central-eastern region of the state of São Paulo. Thus, more studies on wild-type frogs are needed, particularly in the settings of frog farms with positive animal history for FV3, to better understand the epidemiology and dynamics of ranavirus transmission among wild frogs.
724

Exploração funcional do processo de glicosilação aberrante em tumores: mecanismos envolvidos na atividade pró-migratória de galectina-3 / Exploiting the functional significance of aberrant glycosylation in tumors: mechanisms involved in the promigratory activity of galectin-3

Melo, Fabiana Henriques Machado de 23 February 2006 (has links)
Ao longo do processo de progressão tumoral, se observa alteração na expressão de glicoconjugados contendo oligossacarídeos N-ligados. Uma das formas mais comuns de glicosilação aberrante observada em células transformadas e em tumores humanos é representada por (poli)lactosaminas presentes em oligossacarídeos N-ligados. Estes glicanos são ligantes de galectina-3. Com o objetivo de identificar a expressão e distribuição dos ligantes de galectina-3 associados a processos fisiopatológicos, como a transformação maligna, desenvolvemos uma proteína quimérica, a galectina-3 conjugada a fosfatase alcalina (Gal-3/FA). Observamos que a Gal-3/FA possui a mesma especificidade de galectina-3 e que pode ser usada como sonda em ensaios de overlay e ensaios de imunoistoquímica. Entre os ligantes de galectina-3 identificamos a ?1 integrina, mediador de processos biológicos dependentes da interação célula-matriz como a migração celular. Linhagens de células de origem mesenquimal derivadas de tumores induzidos com metilcolantreno de animais selvagens (linhagens S11 e S12) e nulizigoto (linhagem ?12) para o gene da galectina-3 foram estabelecidas. Avaliamos a capacidade migratória dessas células e os nossos resultados mostraram que células que expressam galectina-3 são mais migratórias em superfícies de laminina-1. Este dado sugere que a galectina-3 seja um modulador positivo do processo de migração celular em superfícies de laminina-1. No entanto, o mecanismo pelo qual a galectina-3 medeia esse processo não é conhecido. Células que possuem fenótipo mais migratório apresentam um estado intermediário de adesão. Nós observamos que a galectina-3 se encontra nos complexos focais. Na presença de galectina-3 observamos diminuição de FAK fosforilado e recrutamento da fosfatase SHP-2 para os complexos focais. A diminuição de FAK fosforilado no lamelipódio leva ao turnover dos complexos focais e ao aumento da migração celular. Analisamos também a via de sinalização e observamos que a galectina-3 não ativa PAK. Contudo, o inibidor de PI3quinase, wortmanina, inibiu o efeito pró-migratório de galectina-3. Esses dados reforçam a noção do papel de galectina-3 na modulação do processo de migração de fibroblastos transformados, funcionando como uma molécula / Altered expression of cell surface N-linked oligosaccharides are often associated with malignant transformation of cells. One of the most common forms of aberrant glycosylation in transformed cells and human tumors is the highly elevated ?1,6 branching of N-linked oligosaccharides caused by increased expression of N-acetylglucosaminytransferase V (Mgat5). Galectin-3, a ?-galactoside binding protein, binds preferentially to poly-N-acetyllactosamines, which are the products of Mgat5. In order to exploit this hallmark of cancer cells, we have developed a tool for in situ identification of these tumors associated glycoconjugates. Human galectin-3 was fused to bacterial alkaline phosphatase, generating a hybrid molecule displaying both the carbohydrate binding properties of galectin-3 and enzymatic activity of alkaline phosphatase (Gal-3/FA). Gal-3/FA has the same fine of galectin-3 which was confirmed in direct binding assays. The tool presented herein was therefore useful for several immunoenzymatic assays, and will allow to establish whether the expression pattern of galectin-3 ligands have any physiological or clinical significance. We have identified ?1 integrin as a galectin-3 ligand. ?1 integrins are the actual effector of cell adhesion and migration. We have established cell lines from methylcholantrene-induced sarcomas from both wild type and galectin-3 null mice. In this system, galectin-3 null cells were less migratory than control cells in laminin-1. When galectin-3 was transiently expressed in galectin-3 null sarcoma cells, it inhibited cell adhesion to laminin-1 and stimulate the migratory response to laminin-1. The addition of exogenous galectin-3 also enhanced the migratory capacity of ?12 cells in a carbohydrate dependent way. Galectin-3 was found in focal contacts of ?12 cells where it may interact with many glycoproteins containing polyllactosamines on the cell surface. Here we showed that ?1 integrins are among them. Exogenously added galectin-3 led to a decrease in phosphorylated-FAK in lamellipodia and increased the recruitment of Shp-2 phosphatase of migrating cells. The effect of galectin-3 in migration was not dependent on the activation of the p21-activated kinase (PAK). Wortmannin inhibited the increased migration elicited by galectin-3, suggesting the involvement of the PI3-kinase signaling in the galectin-3 pathway. We propose that extracellular galectin-3 bound ?1integrins and disrupted the focal adhesion plaque, thus favoring cell migration.
725

Aspectos celulares e moleculares da ranavirose experimental em tilápias do Nilo (Oreochromis niloticus) / Cellular and molecular aspects of the experimental ranavirus infection in Nile tilapias (Oreochromis niloticus).

Marcelo Candido 10 December 2018 (has links)
Algumas doenças associadas à piscicultura de tilápias trazem enormes prejuízos aos criadores, resultando em expressivos coeficientes de morbidade e mortalidade entre animais de todas as idades. Nesse sentido, exigências para o aprimoramento do diagnóstico laboratorial de doenças de natureza infecto-contagiosa tornaram-se constantes, face às perdas vinculadas. Os Ranavirus são vírus que infectam vertebrados ectotérmicos causando necrose generalizada, hemorragias focais e apoptose celular nos animais infectados. O presente estudo objetivou a realização de infecções experimentais em larvas e alevinos de tilápia do Nilo (Oreochromis niloticus), através de 3 diferentes modelos de infecção, utilizando estirpe de Ranavirus Frog vírus 3-like; recentemente detectada e isolada no Brasil, para avaliação das patologias associadas, incluindo o sequenciamento e análise do genoma da cepa viral. Vários sinais clínicos macroscópicos e microscópicos foram observados, hemólise, hemácias com anisocitose e policromasia, alterações relacionadas a média dos volumes das hemácias e hemoglobina, índices hepato-somáticos e espleno-somáticos com interações estatisticamente significantes, linfócitos reativos, alterações nos níveis das enzimas alanina aminotransferase e corpúsculos de inclusão basofílicos em diferentes tecidos dos animais experimentados com Ranavirus FV3-like foram observados dentro do período de 60 dias pós-infecção. Além disso, animais experimentalmente infectados foram positivos ao Ranavirus através de qPCR. O genoma de cepa brasileira de Ranavirus FV3-like apresentou 105 kilobases, contendo 54,98% de guanina + citosina, sendo 94 potenciais ORFs anotadas. A reconstrução filogenética, baseada em sequencias nucleotídicas, agrupou a amostra brasileira de Ranavirus no clado dos Frog vírus 3-like e as maiores identidades do genoma se deram com cepas norte-americanas de FV3-like. Doze potenciais eventos de recombinação, estatisticamente significantes (p < 0,05), foram identificados entre a cepa brasileira e amostras de referência de Ranavirus FV3-like. Nesse sentido, o presente trabalho contribui para o melhor entendimento da infecção causada por estirpe brasileira de Ranavirus FV3-like em tilápias do Nilo (Oreochromis niloticus). Além disso, adiciona e reforça a potencial recombinação entre diferentes estirpes de Ranavirus, colaborando para uma melhor compreensão das características de agentes virais associados a graves surtos em vertebrados ectotérmicos no país. / Some diseases associated with tilapia fish farming cause enormous losses to breeders, resulting in significant morbidity and mortality rates among animals of all ages. In this sense, requirements for the improvement of the laboratory diagnosis of diseases of infectious-contagious nature, became constant, in view of the related losses. Ranaviruses are viruses that infect ectothermal vertebrates causing widespread necrosis, focal haemorrhages and cell apoptosis in infected animals. The present study aimed to perform experimental infections in Nile tilapia (Oreochromis niloticus) fry and larvae through 3 different infection models, using Ranavirus Frog virus 3-like strain recently detected and isolated in Brazil, to evaluate the associated pathologies, including sequencing and genome analysis of the viral strain. Several macroscopic and microscopic clinical signs were observed, hemolysis, red blood cells presenting anisocytosis and polychromasia, alterations related to the mean red blood cell volumes and hemoglobin present in the red blood cells, hepato-somatic and spleno-somatic indexes showing statistically significant interactions, reactive lymphocytes, alterations in the levels of the enzymes alanine aminotransferase and basophilic inclusion corpuscles in different tissues of animals tested with Ranavirus FV3-like were observed within the 60-day post-infection period. In addition, experimentally infected animals were positive to Ranavirus through qPCR. The genome of the Ranavirus FV3-like Brazilian strain presented 105 kilobases, containing 54.98% of guanine + cytosine, with 94 potential ORFs annotated. The phylogenetic reconstruction, based on nucleotide sequences, grouped the Brazilian sample of Ranavirus in the clade of Frog virus 3-like, the greater identities of the genome were with North American strains of FV3-like. Twelve potential recombination events, statistically significant (p <0.05), were identified between the Brazilian strain and reference samples of Ranavirus FV3-like. The present work contributes to a better understanding of the infection caused by the Brazilian strain of Ranavirus FV3-like in Nile tilapia (Oreochromis niloticus). In addition, it adds and reinforces the potential recombination between different strains of Ranavirus, contributing to a better understanding of the characteristics of viral agents associated with severe outbreaks in ectothermic vertebrates.
726

Imagerie quantitative du dépot d'aérosols dans les voies aériennes par résonance magnétique de l'hélium-3 hyperpolarisé / Hyperpolarized helium-3 MRI for detection and quantification of aerosol deposition in the airways

Sarracanie, Matthieu 06 July 2011 (has links)
Le paysage des thérapies inhalées connaît de profondes évolutions depuis les deux dernières décennies, avec pour objet la considération nouvelle du poumon comme un site de transfert des agents thérapeutiques vers le compartiment sanguin. Cette approche originale est apparue par la combinaison de développements théoriques et pratiques multiples impliqués dans la mise au point de nombreux médicaments, depuis le traitement de la douleur et du diabète jusqu'à la vaccination et le traitement de certains cancers. La quantité effective de médicament délivrée par aérosols est pondérée par de nombreux facteurs dont le mode et les conditions d’inhalation, les propriétés physiques des gaz en jeu, la morphologie des voies respiratoires ou encore les propriétés physico-chimiques des particules véhiculées. Les développements en cours ces quatre dernières années ont été conditionnés par des résultats encore mal compris, soulignant les limites des connaissances sur le transport et le dépôt d'aérosols dans le poumon. Ces manques mettent en avant le besoin d'outils performants pour l'évaluation du dépôt de particules dans les voies respiratoires.Les techniques d’imagerie permettent à la fois l’évaluation spatiale et quantitative du dépôt, avec pour seules références aujourd’hui, les techniques de médecine nucléaire. Outre l’aspect ionisant de ces techniques, elles bénéficient d’une sensibilité de détection encore inégalée. Elles demeurent néanmoins limitées par des résolutions spatiale et temporelle faibles, rendant le plus souvent difficile tant l’interprétation du dépôt que le rôle joué par les principaux mécanismes de clairance dans les voies aériennes. Depuis la fin des années 1990, les techniques de résonance magnétique imagent des noyaux hyperpolarisés (hélium-3 et xenon-129) et établissent de nouveaux standards dans l’exploration de la fonction pulmonaire.Cette thèse établit, sur la base de l’IRM de l’hélium-3 hyperpolarisé, une nouvelle modalité d’imagerie pour détecter et quantifier le dépôt d’aérosols dans les voies aériennes.Dans un premier temps, et dans un contexte où l’imagerie par résonance magnétique ne s’était pas encore penchée sur la problématique des aérosols thérapeutiques, un vaste travail d’investigation a été mené pour évaluer la sensibilité de l’IRM de l’hélium-3 hyperpolarisé au dépôt d’aérosols marqués à base d’oxyde de fer superparamagnétique. Le second volet de ce travail s’est porté sur la validation de notre méthode d’évaluation, et sur le développement de la quantification du dépôt d’aérosols. Nous avons enfin pu tester la reproductibilité de notre méthode d’évaluation du dépôt in vivo chez le rat, grâce à la réalisation d’une plateforme de ventilation et d’administration de gaz et d’aérosols dédiée, SAGAS. / Inhalation therapy has broadened its field of application over the last two decades by considering the lung not only as an organ to cure, but also as a portal toward systemic circulation. This new approach is being made possible by the emergence of biotherapeutics and a greater understanding of the absorption properties of the lung. Systemic delivery across the oronasal route was then investigated for a number of indications including migraine, diabetes, pain, and cancer. However, progress into the market of systemic aerosolized drug delivery has been slowed down to-date by a number of confounding factors including rapid clearance, instability, long-term toxicity, and dosing issues. Final drug distribution in such complex geometries strongly depends on a variety of parameters like the aerosol administration protocol, particle size, density, and physicochemical properties, as well as the airway geometry. Independently of drug formulation and pharmacokinetic considerations, these parameters determine the deposition distribution throughout the lung. Quantification and spatial localization are primordially needed to better control and optimize drug concentration at specific or less- and nonspecific sites. Nuclear medicine techniques are currently the only available modalities that combine both aerosol quantification and regional localization. They are considered as reference techniques even though they remain limited by their spatial and temporal resolutions as well as by patient exposure to radiations. With regard to lung imaging, hyperpolarized helium-3 MRI has been developed as a powerful tool to quantitatively characterize the parenchyma and the organ function and morphology. The technique is innocuous and provides millimeter and sub-second resolutions with rather high signal to noise ratios. In this thesis, a new imaging modality was developed on the grounds of hyperpolarized helium-3 MRI to probe and quantify aerosol deposition in the airways. In the first part of the thesis, I describe the potential of helium-3 MRI to probe aerosol deposition by using superparamagnetic contrast agents. The second part mainly focuses on the validation of this new modality by comparing it to a reference technique, single photon emission computed tomography (SPECT), and computational fluid dynamics. The last part of the manuscript is dedicated to aerosol administration and in vivo measurements in rat lungs. This experiment was possible by designing and building an MR compatible gas administrator and ventilator dedicated to small animals, SAGAS (Small Animal Gas Administration System). Its complete hardware and software description is presented in the same chapter.
727

Influence des Acides Gras Poly-Insaturés n-3 (oméga3) sur les intéractions Neurones/Astrocytes au cours du vieillissement cérébral : aspects cognitifs et cellulaires / Impact of omega 3 fatty acids on the interaction between astrocyte and neurone during brain aging : cognitive and cellular aspects

Latour, Alizée 06 June 2013 (has links)
Un statut pauvre en Acides Gras Poly-Insaturés ω3 (AGPI ω3), favorisé par une alimentation occidentale comportant un faible ratio en ω3/ω6, semble contribuer au déclin cognitif chez les personnes âgées, mais les mécanismes cellulaires impactés sont encore mal connus. Nous avons donc étudié l’influence du statut en ω3 sur l’évolution de la neurotransmission glutamatergique et des fonctions astrocytaires au cours du vieillissement dans l’hippocampe de rats. Ces processus sont impliqués dans la formation de la mémoire et leurs dérégulations participent aux dommages cérébraux conduisant au déclin cognitif. Nous avons comparé 6 groupes de rats agés de 6 et 22 mois nourris avec un régime déficient en ω3, équilibré en ω3/ω6 ou supplémenté en ω3 (huile de poisson) : Jeunes équilibrés (JEq), déficients (JDef) ou supplémentés (JSup) et Agés équilibrés (AEq), déficients (ADef) ou supplémentés (ASup). Nous avons évalué l’efficacité synaptique et la plasticité (enregistrements électrophysiologiques), les fonctions astrocytaires (capture de glutamate et expression de la GFAP), les marqueurs neuronaux (transporteurs et récepteurs du glutamate), les capacités cognitives (Openfield et Labyrinthe de Barnes) et analysé la composition lipidique cérébrale. Les manipulations nutritionnelles d’apport en ω3 modifient efficacement l’incorporation de l’acide docosahexaénoïque (DHA, principale ω3 des membranes cellulaires) dans le cerveau (-50% deficient vs équilibré, +10% supplementé vs équilibré). Le vieillissement induit une diminution de 35% de l’efficacité synaptique en raison d’une baisse de la libération de glutamate pré-synatique, et une diminution de 30% de la capture de glutamate associé à une astrogliose conséquente (+100% GFAP). La déficience en ω3 acentue les effets du vieillissement (rats ADef vs AEq: -35% efficacité synaptique, -15% capture de glutamate, +30% GFAP). Al’inverse, la supplémentation en ω3 améliore l’efficacité synaptique (rats ASup vs AEq +25%) et semble inhiber l’astrogliose chez le rat âgé (ASup vs JEq : pas de modification de la GFAP). Les tests comportementaux montrent que le vieillissement a des effets plus marqués chez les déficients en ω3 et au contraire atténués chez les supplémentés. Nos résultats révèlent des altérations de la synapse glutamatergique de l’hippocampe au cours du vieillissement aggravées par la déficience en ω3 et atténuées par la supplémentation en ω3. Afin d’évaluer l’influence du statut en ω3 sur l’activation astrocytaire, des modèles in vitro d’astrocytes « âgés » et « activés » par des cytokines inflammatoires dont l’augmentation à bas bruit est caractéristique du vieillissement cérébral, ont été développés. / A poor ω3 polyunsaturated fatty acids (ω3 PUFA) status, favored by the low ω3/ω6 ratio in western diets, seems to contribute to cognitive decline in the elderly, but mechanistic evidence is lacking. We therefore explored the impact of ω3 status on the evolution of glutamatergic transmission and astrocytic functions in the hippocampus during ageing in rats. These processes are involved in memory formation and their dysregulation participates to the age-related brain damage leading to cognitive decline. We have compared 6 groups of rats aged 6 to 22 months fed ω3-deficient, ω3/ω6-balanced, or ω3 (fish oil) supplemented diets: Young ω3 Balanced (YB), Deficient (YD) or Supplemented (YS), and Old ω3 Balanced (OB), Deficient (OD) or Supplemented (OS) rats. We have evaluated synaptic efficacy and plasticity (electrophysiological recording), astroglial regulations (glutamate uptake and GFAP expression), neuronal markers (glutamate transporters and receptors), cognitive abilities (Barnes maze and Openfield) and analyzed brain fatty acids composition. Dietary modulation of ω3 intakes efficiently modified the incorporation of docosahexaenoic acid (DHA, the main ω3 in cell membranes) in brain (-50% deficient vs balanced, +10% supplemented vs balanced). Ageing induced a 35% reduction of synaptic efficacy due to decreased pre-synaptic glutamate release, and a 30% decrease in the astroglial glutamate uptake associated to a marked astrogliosis (+100% GFAP). ω3 deficiency further decreased these hallmarks of ageing (OD vs OB rats: -35% synaptic efficacy, -15% glutamate uptake, +30% GFAP). On the opposite, ω3 supplementation increased synaptic efficacy (+25% OS vs OD) and seems to abolish astrogliosis (OS vs YS : no change in GFAP). Behavioural tests showed some increased effects of age in deficient rats and attenuated effects in supplemented ones. Our results characterize some specific age-related alterations of the glutamatergic synapse in the hippocampus that are aggravated by a dietary deficit in ω3 and attenuated by ω3 supplementation. In order to explore ω3 status on astrocytic activation, in vitro models of “old” astrocytes and “activated” by inflammatory cytokines which characterize the low-grade inflammation in brain aging, have been developed.
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Determinantes do consumo de pescado na população que freqüenta feiras livres do município de Santo André, SP / Determinants of fish choosing in street markets from Santo André, SP

Vasconcellos, Juliana Parreira 01 October 2010 (has links)
O objetivo deste estudo foi identificar os determinantes de consumo de peixe na população que freqüenta feiras livres do município de Santo André, SP. Foram entrevistadas 482 pessoas em 49 feiras-livres. Aplicou-se um questionário constituído de questões abertas, semi abertas e fechadas destinadas a identificação e avaliação das características sócio-econômicas, fatores que facilitam e dificultam o consumo de peixe e os aspectos considerados para avaliar o frescor do produto. Foi realizada análise descritiva dos dados e posteriormente foram aplicados testes para verificar associação e linearidade entre as variáveis com o consumo, com nível de significância de 5%. Os fatores que facilitam o consumo de peixe foram: renda, escolaridade completa, forma de apresentação do produto, aquisição em feiras livres, sabor, aparência, firmeza da carne e presença de crianças na família. Já os fatores que limitam o consumo foram: preço e espinhos. A perecibilidade, odor, etnia, proximidade dos pontos de venda da residência e do trabalho, sexo, idade, número de pessoas no lar e aquisição em supermercado não foram características que influenciaram a decisão de compra e consumo de peixe. Os aspectos considerados para avaliar o frescor do peixe foram predominantemente visuais. / The objective of this study was to identify the determinants of fish consumption in the population that frequents the street markets of the Santo André municipality, State of São Paulo, by interviewing a total of 482 persons in 49 markets. A questionnaire constituted of open, semi-open and closed questions was applied in order to identify and evaluate the socio-economic characteristics of the population, factors that make easy or difficult the fish consumption, and the aspects considered for the evaluation of the freshness of the products. Descriptive analysis of the data was carried out and subsequently statistical tests were applied to check the existence of association and linearity between the variables and the consumption, using a level of significance of 5 %. The factors that make easy the consumption of fish were: income, complete schooling, and presentation of the product, acquisition in free markets, taste, appearance, firmness of the flesh, and the presence of children in the families. On the other side, the factors that limit the consumption were the price and the fish thorns. The fact of being easily perishable, odor, ethnic, proximity of the points of sale from the residence and of the work, sex, age, number of persons in the home, and acquisition in supermarkets were not characteristics influencing the decision of purchase and consumption of fish. The aspects considered to evaluate the freshness of the fish were predominantly visual.
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Glimepirida melhora a sensibilidade à insulina em ratos obesos (MSG), sem exacerbar a obesidade. Mecanismos moleculares envolvidos nos tecidos muscular, adiposo e hepático. / Glimeiride improves insulin sensitivity in MSG obese rats, without aggravating the obesity. Molecular mechanisms involved in muscular, adipose and hepatic tissues.

Mori, Rosana Cristina Tieko 28 August 2007 (has links)
O estudo investigou a ação sensibilizadora à insulina da glimepirida (Gp), em ratos MSG, resistentes à insulina. Animais controle (C) e MSG, e tratados (CG e MSG/G) ou não com Gp, foram submetidos a ITT; análise do GLUT4 no tecido adiposo (TAB), EDL, sóleo e coração; ensaios de translocação e captação de glicose/incorporação ao glicogênio no sóleo; dosagem do glicogênio e p-GSK3 no fígado. No TAB, mRNA e proteína GLUT4 se elevaram nos MSG, o que foi revertido pela Gp, efeito importante para não agravar a obesidade. No sóleo, o mRNA aumentou nos MSG, mas a proteína GLUT4 foi igual a C, e se elevou com a Gp. Sob estímulo insulínico, GLUT4 em membranas plasmáticas aumentou em ratos C e MSG/G. Captação de glicose e incorporação ao glicogênio muscular no sóleo, conteúdo de glicogênio e de p-GSK3 no fígado foram menores nos MSG. A Gp aumentou a expressão/translocação de GLUT4 em músculo de ratos MSG, melhorando a captação de glicose e glicogeniogênese neste tecido. Estes efeitos, mais o aumento da glicogeniogênese hepática, conferem à Gp ação sensibilizadora à insulina. / The study investigated the insulin sensitizer action of the glimepiride (Gp) in insulin- resistant MSG rats. Control (C) and MSG animals, non-treated or treated with Gp (CG and MSG/G) were submitted to ITT; GLUT4 analysis in adipose tissue (WAT), EDL, soleus and heart; GLUT4 translocation assays and glucose uptake/glycogen incorporation in soleus; glycogen and p-GSK3 analysis in the liver. In WAT, GLUT4 mRNA and protein increase in MSG rats was abolished by Gp, an effect important to avoid the aggravation of the obesity. In MSG soleus, GLUT4 mRNA increased but protein was similar to C, elevating after Gp. Under insulin stimulation, GLUT4 in plasma membrane increased in C and MSG/G only. Glucose uptake and incorporation to muscular glycogen in soleus, and glycogen/p-GSK-3 content in the liver were all lower in MSG rats. Gp increased GLUT4 expression/translocation in MSG muscle, improving glucose uptake and glycogenesis in this tissue. These effects, added to the higher hepatic glycogenesis confer the Gp its insulin sensitizer action.
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Caracterização imuno-histoquímica da Galectina-3 como ferramenta prognóstica em melanomas orais caninos / Immunohistochemical characterization of Galectin-3 as prognostic tool in canine oral melanomas

Thiago Henrique Moroni Vargas 02 February 2018 (has links)
Os melanomas correspondem a 7% de todas as neoplasias malignas em cães e são principalmente encontrados em cavidade oral e lábios, correspondendo a 33% dos tumores de boca, possuem um prognóstico ruim devido ao fato de serem diagnosticados tardiamente, por sua grande capacidade de invasão local e formação de metástases, além de altas taxas de recidiva após o tratamento cirúrgico. A Galectina-3 (Gal-3) é uma proteína responsável por diversas funções fisiológicas como adesão, apoptose, angiogênese, proliferação e diferenciação. Em medicina veterinária existem poucos estudos relacionando à expressão da Gal-3 com prognóstico e a progressão da neoplasia. Realizamos imuno-histoquímica para Gal-3 em 27 melanomas orais caninos que foram avaliados de maneira semiquantitativa e quantitativa, e comparamos os resultados obtidos com a sobrevida, outros marcadores prognósticos (Ki67, índice mitótico e atipia nuclear), expressão de proteínas relacionadas à apoptose (BCL2 e CASP3) e parâmetros histopatológicos (grau de pigmentação e tipo histológico). Detectamos alta expressão de Gal-3 em melanomas com maior sobrevida pós-cirúrgica e uma alta expressão nuclear de Gal-3 em melanomas com menor sobrevida pós-cirúrgica. Além disso, houve correlação entre as expressões de Gal-3 e BCL2, assim como entre atipia nuclear e sobrevida pós-cirúrgica. É sabido que a Gal-3 é capaz de formar heterodímeros com a BCL2 no citoplasma para atuar na evasão da morte por apoptose, impedindo a liberação da citocromo C. Já no núcleo, a Gal-3 induz à parada do ciclo celular, reduzindo a taxa da proliferação. Apesar do reduzido número amostral devido à dificuldade nos acompanhamentos clínicos nossos dados permitem sugerir que a Gal-3 é possui potencial para ser um marcador prognóstico de sobrevida em casos de melanomas orais caninos. Novos estudos devem ser realizados afim de confirmar nossas observações e elucidar o papel da Gal-3 nesta neoplasia. / Melanomas are almost 7% of all malignant neoplasms in dogs. They are mainly found in the oral cavity and lips, corresponding to 33% of tumors of the oral cavity. They carry a poor prognosis because of late diagnoses, local invasiveness, high metastatic and recurrence rates after surgical treatment. Galectin-3 (Gal-3) is a protein with a variety of biological roles such as in adhesion, apoptosis, angiogenesis, proliferation and differentiation. In veterinary medicine, there are few studies comparing the expression of Gal-3 with prognosis and tumor progression. We performed immunohistochemistry for Gal-3 in 27 canine oral melanomas and evaluated the immunolabelling both semi-quantitatively and quantitatively. The results were compared with survival, other prognostic markers (Ki67, mitotic index and nuclear atypia), expression of proteins related to apoptosis (BCL2 and CASP3) and histopathological parameters (degree of pigmentation and histological type). We detected higher expression of Gal-3 in cases of melanoma that presented longer post-surgical survival and a higher nuclear expression of Gal-3 in dogs with melanoma that had shorter post-surgical survival. In addition, there was correlation between the Gal-3 and BCL2 expressions, as well as between nuclear atypia and post-surgical survival. It is known that Gal-3 is able to form heterodimers with BCL2 in the cytoplasm leading to evasion of apoptosis, through preventing mitochondrial cytochrome C release. Nuclear Gal-3 induces the cell cycle arrest, reducing the proliferation rate. Despite the small sample size due to the difficulty in clinical follow-up, our data suggest that Gal-3 has the potential to be a prognostic marker for survival in cases of canine oral melanomas. Further studies should be performed to confirm our observations and elucidate the role of Gal-3 in this neoplasm.

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