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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.
41

Développement et valorisation d'un modèle animal de gale sarcoptique. Evaluation de molécules acaricides / Use of an animal model for study of human scabies and animal sarcoptic mange. Evaluation of acaricide molecules

Fang, Fang 15 April 2016 (has links)
Sarcoptes scabiei est un acarien ectoparasite obligatoire. Sa présence dans la couche cornée de l’épiderme est à l’origine d’une gale dite sarcoptique. Cette ectoparasitose a été décrite chez 104 espèces de mammifères représentant 27 familles distinctes. Les traitements actuels de la gale sarcoptique ne sont pas toujours satisfaisants et il n’existe pas de produits qui permettent d’éliminer S. scabiei dans l’environnement. Par ailleurs, la diversité génétique de S. scabiei n’est pas clairement définie et l’unicité de l’espèce fait toujours l’objet de controverses.L’objectif de cette thèse a été d’évaluer l’efficacité d’acaricides vis-à-vis de S. scabiei en utilisant un modèle animal ou par le biais de tests in vitro. La diversité génétique d’isolats d’origine animale a également été étudiée. La première partie du travail de thèse a concerné un essai thérapeutique L’efficacité d’une administration orale unique d’afoxolaner, une molécule du groupe des isoaxazolines, a été évaluée sur des porcs expérimentalement infestés. Le critère principal d’évaluation a été la réduction du nombre de sarcoptes mis en évidence dans les raclages cutanés. Huit jours après le traitement, aucun sarcopte n’a été détecté sur les 4 porcs ayant reçu l’afoxolaner alors que des sarcoptes étaient toujours présents sur les 3 porcs ayant reçu de l’ivermectine. Tous les porcs traités étaient guéris à la fin de l’essai (J35) alors que les animaux non traités sont demeurés infestés. Les autres critères d’évaluation étaient l’évolution du score clinique et de prurit. Les lésions cutanées ont rapidement régressé dans le groupe traité par l’afoxolaner alors qu’elles étaient encore présentes à J14 dans le groupe traité avec l’ivermectine. La deuxième partie du travail de thèse a porté sur l’évaluation in vitro de différentes molécules ou produits acaricides. Plusieurs concentrations d’une solution d’ivermectin ou de moxidectine ainsi 11 huiles essentielles ont été testées. Après 24h de contact avec l’ivermectine et la moxidectine, la dose létale 50% étaient de 150,2±31,4 µg/mL et 608,3±88,0 µg/mL, respectivement. Une concentration inférieure à 1 ng/mL (pour l’ivermectine) ou à 10 ng/mL (pour la moxidectine) n’a aucune activité acaricide. Pour les huiles essentielles, des tests par fumigation et par immersion ont été réalisés. Parmi Lavandula augustifolia, Melaleuca altenifolia, Pelargonium asperum, Eucalyptus radiate, Leptospermum scoparium, Cryptomeria japonica, Citrus aurantium ssp amara et 3 l’huile essentielle identifiée (BOB4, BOB5, BOB9) testés par immersion, l’huile essentielle identifiée BOB4 s’est révélée la plus efficace (une solution à 1% tue tous les acariens en 20 min). Parmi les 10 huiles essentielles énumérées avant, plus Juniperus oxycedrus testés par immersion, l’huile essentielle de Melaleuca altenifolia s’est révélée la plus efficace (tous les acariens sont morts en 4 min). Pour le contrôle de S. scabiei dans l’environnement, différents biocides ou répulsifs ont été examinés. La durée moyenne de survie a été calculée pour les produits comportant de la perméthrine, de l’esdépallethrine et de la bioresmethrine, de la bifenthrine, de la cyperméthrine et de l’imiprothrine, de la cyfluthrine, de la tétramethrine et de la sumithrine, du DEET, de l’icaridine et le produit IR3535. La deuxième partie du travail de thèse a porté sur la diversité génétique d’isolats de S. scabiei provenant d’animaux. Une partie du gène cox1 a été amplifiée. L’analyse des séquences ainsi obtenues semble montrer que les sarcoptes circulant chez le Chien sont issus de population de sarcoptes d’origine humaine. / Sarcoptes scabiei is an ectoparasite responsible for the emerging/re-emerging disease called scabies in humans or mange in animals. It was reported in 104 species across 27 families of domestic and wild animals. Current treatments for scabies/mange are limited and there are no efficient products for the environment control of S. scabiei. Moreover, the taxonomic status of S. scabiei is still under controversy and the question remains that whether it represents a single species or several taxa.The objectives of the thesis were to assess the susceptibility to acaricides and analyse the genetic diversity of S. scabiei from animals. In the first part of the thesis, an animal model was used to evaluate the efficacy of afoxolaner, a new acaricide from the isoaxazoline family. The primary outcome of efficacy was based on the reduction in the number of live mites counted in skin scrapings following treatment. At day 8, four afoxolaner-treated pigs (out of four) were mite-free, while mites were still found in three (out of three) ivermectin-treated pigs. All treated pigs were cured at the end of the study (day 35) and all pigs in the control group remained infected. Secondary outcomes included measures on the reduction of skin lesions and pruritus. The clinical lesions of scabies infection were allowed to disappear completely for all the pigs in the afoxolaner group but not in the ivermectin group at 14 days after the treatment. An increase of the pruritus was observed right after treatment, followed by a decrease of the pruritus score in both treated groups. The second part of the thesis was to evaluate the scabicidal effect of molecules or products using an in vitro test. A gradient of concentrations of ivermectin and moxidectin as well as 11 essential oils have been evaluated in vitro against S. scabiei. After 24h of exposure to ivermectin and moxidectin, the median lethal concentrations were 150.2±31.4 µg/mL and 608.3±88.0 µg/mL, respectively. Doses of ivermectin under 1 ng/mL and moxidectin under 10 ng/mL showed no scabicidal effect. Fumigation and contact bioassays were used for the assessment of essential oils efficacy. Among Lavandula augustifolia, Melaleuca altenifolia, Pelargonium asperum, Eucalyptus radiate, Leptospermum scoparium, Cryptomeria japonica, Citrus aurantium ssp amara and 3 other unknown oils (BOB4, BOB5, BOB9) tested with the contact bioassay, the essential oil identified as BOB4 demonstrated the best scabicidal effect (1% solution killed all the mites in 20 min). Among the 10 essential oils listed before plus Juniperus oxycedrus with the fumigation bioassay, the oil Melaleuca altenifolia demonstrated the best scabicidal effect (all the mites died in only 4 min). For environmental control of S. scabiei, the efficacy of biocides or repellents was assessed. The median survival time was calculated for permethrin (4% and 0.6%), esdepallethrin and bioresmethrin, bifenthrin, cypermethrin and imiprothrin, cyfluthrin, tetramethrin and sumithrin, DEET (25% and 50%), icaridin and IR3535. The third part of the thesis included the study of the genetic diversity of populations of S. scabiei from animals. A part of cox1 was used for phylogenetic analyses. The results showed that Sarcoptes mites from dogs seem to derive from humans.
42

Famille des Marseilleviridae : étude de la pathogénicité potentielle et description du pan-génome / Family of Marseilleviridae : study of potential pathogenicity and description of pangenome

Aherfi, Sarah 16 September 2016 (has links)
Marseilleviridae est une famille de virus géants isolés initialement à partir de prélèvements environnementaux, dont Marseillevirus est le membre fondateur. La présence des marseillevirus chez l’Homme a été démontrée dans quelques études. Les objectifs sont de mieux documenter la présence des marseillevirus chez l’Homme, de modéliser l’infection par Marseillevirus chez la souris, et enfin, de décrire les génomes des marseillevirus. Nous rapportons un cas d’infection par Marseillevirus chez une patiente atteinte d’un cancer des ganglions, soulevant la question d’un éventuel lien entre Marseillevirus et cancer, à l’instar de l’association existant entre d’autres virus et les cancers. L’infection des souris par Marseillevirus montre que celui-ci persiste un mois au niveau des «amygdales», confirmant le portage pharyngé chronique observé chez un deuxième patient. Enfin, nous identifions deux nouveaux groupes au sein de la famille, soulignant l’importante diversité génétique de la famille. / Marseilleviridae is a new family of giant viruses primarily isolated from environmental samples and whose Marseillevirus is the founding member. The presence of marseilleviruses in humans has been demonstrated in few studies. The aims are to better document the presence of marseilleviruses in humans, to develop a model of infection of mice with Marseillevirus, and to describe the genomes of marseilleviruses. We report a first caes of infection by Marseillevirus in apatient with a lymph nodes cancer, raising the question of a potential link between Marseillevirus and cancer, as the well established association between some viruses and cancers. The infection of miceshows that Marseillevirus persist one month in the “tonsils”, confirming the chronic pharyngeal carriage reported in a second patient. Finally, we identify two new subgroups in the family, highlighting the considerable genetic diversity of the family.
43

Tipos celulares no córtex medial do lagarto Tropidurus hispidus

Almeida, Fabríco Tavares Cunha de 30 March 2007 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to characterize the ependymal cells and neural population in the Tropidurus hispidus medial cortex. It s well known nowadays that the nervous system isn t so constant the way was believed and detains morphological and functional properties that was influenced by environmental, sexual, age alterations and origin of the lesion like others. There s a vast literature about studies of amphibians, birds, reptiles even mammals brains, but one of the major difficulties found in the nervous system s plasticity research area is the appropriated experimental model. The medial cortex of Tropidurus hispidus specimens was studied by several techniques as TIMM, Nissl, immunostainings to BrDU, GABA, EC40, by Lectin and mainly the Golgi method. The test results showed the existence of 17 neuronal types in the T. hispidus medial cortex, with the major prevalence of the unipolar granular neuron, showed 12 ependymal cells, showed the positive reactivity to the GABA, BrDU and EC40 immunostainings too, the two lasts shows a post-natal neurogenic activity in the cortical region of this animal. Also was positive reactivity to the Lectin utilization in the microglia visualization. With the analysis of all this aspects, the study in the Tropidurus hispidus medial cortex showed a structural complexity as other characteristics that turn this animal a viable experimental model to the neurogenic processes studies. / O objetivo deste trabalho foi caracterizar a população neural e de células ependimárias no córtex medial do lagarto Tropidurus hispidus. Sabe-se atualmente que o sistema nervoso não é tão constante como se pensava e que detêm propriedades morfológicas e funcionais que são influenciadas por alterações ambientais, sexuais, etárias, da natureza da lesão dentre outras. Toda essa problemática vem sendo analisada tendo como base a regeneração do sistema nervoso. Há vasta literatura sobre estudo dos cérebros desde anfíbios, aves répteis até mamíferos e mesmo humanos, mas uma das maiores dificuldades para a pesquisa na área de plasticidade do sistema nervoso é um modelo experimental adequado. Para isto, no presente estudo o córtex medial dos espécimes de Tropidurus hispidus foi estudado por diversas técnicas como TIMM, Nissl, imunohistoquímicas para BrDU, GABA, EC40, pela Lectina e principalmente pelo método de Golgi. Os resultados dos testes demonstraram a existência de 17 tipos de neurônios no córtex medial do cérebro do T. hispidus, sendo que o tipo de maior prevalência foi o do neurônio granular unipolar, o teste de Golgi também mostrou 12 tipos de ependimócitos, verificando-se reatividade positiva à imunohistoquímica para GABA, para BrDU e para EC40, esses dois últimos demonstraram uma atividade neurogênica pós-natal na região cortical desse animal. Também houve uma reatividade positiva à utilização da Lectina na visualização da micróglia. Haja vista aos aspectos analisados, o estudo no córtex medial do T. hispidus denotou uma complexidade estrutural bem como características que o tornam um modelo experimental viável para os estudos dos processos neurogênicos.
44

Three-dimensional Modeling and Simulation of a Tuning Fork

Larisch, Lukas 16 September 2018 (has links)
The mathematical characterization of the sound of a musical instrument still follows Schumann’s laws [1]. According to this theory, the resonances of the instrument body, “the formants”, filter the oscillations of the sound generator (e.g., strings) and produce the characteristic “timbre” of an instrument. This is a strong simplification of the actual situation. It applies to a point source and does not distinguish between a loudspeaker and a three-dimensional instrument. In this work we investigate Finite-Element-based numerical simulations of eigenfrequencies and eigenmodes of a tuning fork in order to capture the oscillation behavior of its eigenfrequencies. We model the tuning fork as an elastic solid body and solve an eigenvalue equation derived from a system of coupled equations from linear elasticity theory on an unstructured three-dimensional grid. The eigenvalue problem is solved using the preconditioned inverse iteration (PINVIT) method with an efficient geometric multigrid (GMG) preconditioner. The latter allows us to resolve the tuning fork with a high resolution grid, which is required to capture fine modes of the simulated eigenfrequencies. To verify our results, we compare them with measurement data obtained from an experimental modal analyses of a real reference tuning fork. It turns out that our model is sufficient to capture the first eight eigenmodes of a reference tuning fork, whose identification and reproduction by simulation is novel to the knowledge of the author.
45

Remodelage vasculaire dans les modèles expérimentaux d'anévrysme de l'aorte abdominale / Vascular remodeling in experimental models of abdominal aortic aneurysms

Coscas, Raphaël 19 May 2017 (has links)
La physiopathologie de l’anévrysme de l’aorte abdominale (AAA) est complexe. Elle implique notamment des facteurs hémodynamiques, une protéolyse matricielle, un stress oxydatif et une réaction immune. Des modèles expérimentaux ont été mis au point pour explorer les mécanismes impliqués dans la genèse et la croissance des AAAs. Dans ce travail, nous explorons le rôle de ces modèles dans la compréhension du remodelage vasculaire des AAAs. Dans une première partie, une revue de la littérature sur les modèles expérimentaux d’AAA est menée. Dans une seconde partie, nous explorons l’origine et le rôle des calcifications des AAAs expérimentaux. Dans une troisième partie, le modèle de xénogreffe aortique décellularisée est utilisé pour étudier le rôle de l’immunité adaptative dans la rupture. Notre revue identifie les principaux modèles d’AAA. Leur limite majeure est la survenue d’une cicatrisation empêchant l’évolution vers la rupture. Notre exploration des calcifications anévrysmales retrouve une co-localisation des calcifications avec de l’ADN libre et un modèle expérimental démontre la capacité de l’ADN libre à induire des calcifications. La croissance anévrysmale est toutefois ralentie par les calcifications. Notre étude sur le modèle de xénogreffe décellularisée retrouve la possibilité d’induire une rupture lorsqu’une pré-sensibilisation contre la matrice extracellulaire est réalisée. Les glycoprotéines de structure et les protéoglycanes semblent être les composants matriciels en cause dans ces ruptures. Les modèles expérimentaux constituent des outils majeurs pour l’étude des mécanismes impliqués dans le remodelage vasculaire des AAAs. / Pathophysiology of abdominal aortic aneurysms (AAA) is complex. It mainly involves hemodynamics, matrix proteolysis, oxidative stress and an immune reaction. Several experimental models have been described to explore mechanisms involved in this disease. In the present work, we explore the role of experimental models in AAA vascular remodeling. First, a literature review regarding experimental models of AAA is performed. Second, we explore the origin and the role of calcifications observed in experimental models. Third, the decellularized xenograft model is used to study the role of adaptive immunity in triggering rupture. Our review identifies main AAA models. Their major limit is aortic healing, preventing evolution toward rupture. We find that AAA calcifications co-localized with free DNA and that free DNA could induce calcifications experimentally. However, AAA growth is decreased by calcifications. The decellularized xenograft model can evolve toward rupture when pre-sensitization against the extracellular matrix is performed. Structural glycoproteins and proteoglycans seems to be the main matrix component involved in these ruptures. Experimental AAA models are major tools to study mechanisms involved in vascular remodeling.
46

A non-isothermal experimental and simulation study of residual wall thickness in Gas Assisted Injection Moulding

Olley, Peter, Mulvaney-Johnson, Leigh, Coates, Philip D. January 2006 (has links)
Yes / A methodical 'design of experiment' approach is used to assess the effect of key control parameters on residual wall thickness (RWT) in Gas Assisted Injection Moulding. An empirical model is produced from which the experimental RWT can be determined at any interpolated point. This model includes only those terms with proven statistical significance. The 'true' thermal boundary conditions are determined for a 1-D approximation to the system, this is sufficient to determine the error in a simulation method that enforces coolant temperature as the mould boundary condition for temperature. It is shown that errors in heat-flux and wall temperature are small. A 3-D finite element, pseudo-concentration implementation is presented, with a novel method for simulation of internal gas injection. The simulation is shown to give good agreement with the experimental rate of growth of wall thickness as gas delay is increased; good qualitative agreement is shown for other control parameters.
47

Progression of retinal ganglion cell loss observed as a result of anterior segment dysgenesis following conditional deletion of activating protein-2 in cranial neural crest cells

Saraco, Anthony January 2019 (has links)
Our lab has shown that conditionally disrupting the tcfap2beta gene, responsible for the activating protein-2beta (AP-2beta) transcription factor, exclusively in the craniofacial neural crest cells, leads to anterior segment dysgenesis. Subsequent loss of the corneal endothelium results in the adherence of the iris to the corneal stroma, causing closure of the iridocorneal angle. The activating protein-2beta neural crest cell knockout (AP-2beta NCC KO) model involves a complete blockage of the both the conventional (through the trabecular meshwork) and non-conventional (uveoscleral) pathways for aqueous humor drainage, and therefore it could be used as a powerful experimental model for glaucoma. As shown by our previous work, elevated intraocular pressure (IOP) and a 35% decrease in the number of cells in the retinal ganglion cell (RGC) layer was observed in AP-2beta NCC KO mice by 2 months; 6 to 11 months sooner than other reported mouse models of glaucoma. These observations suggested that the AP-2beta NCC KO mouse could be a novel and cost-effective experimental model for glaucoma if the RGC loss occurred progressively rather than due to a congenital defect. The purpose of this research project was to investigate how the retinal ganglion cell layer and macroglial activity changes with respect to age in the AP-2beta NCC KO mutant through immunofluorescence. Specifically, it was investigated whether the loss of RGCs was progressive and due to the increased IOP caused by the blockage of the uveoscleral drainage pathway. A significant decrease in the number of RGCs was observed between P4 and P10 in the retinal periphery of both WT and AP-2beta NCC KO mice (p<0.05), which is indicative of the programmed cell death that occurs due to retinal pruning during development. No statistical difference between WT and AP-2beta NCC KO mice phenotypes was observed at postnatal day 4 (P4), suggesting that no developmental defect resulted in the significant loss of RGCs at 2 months. In all other time points investigated, while no statistical difference was found between WT and the AP-2 NCC KO mutant, a clear downward trend was present in the AP-2 NCC KO mutant retinal ganglion cell layer from P10 to P40. There was also an expression of glial fibrillary acidic protein (GFAP) by Müller cells, indicating the presence of neuroinflammation at P35 and P40. This substantiates the potential P42 starting point of neurodegeneration our lab previously observed. This was further corroborated with Müller cell-associated expression of GFAP at P35 and P40 exclusively in the AP-2beta NCC KO mouse. Overall, we have shown that the retinal damage observed in our AP-2beta NCC KO mouse is not due to a developmental defect, but rather occurs over time. Thus, this mouse model, which appears to block both the conventional and unconventional uveoscleral pathways, has a profound effect on aqueous humor drainage. As a result, the model requires relatively little time to observe an increase in IOP and subsequent RGC loss. Our findings suggest that the AP-2beta NCC KO mouse can be a novel, powerful, and extremely cost-effective experimental model for glaucoma. / Thesis / Master of Science (MSc)
48

Aspectos morfológicos e moleculares do modelo experimental da tioacetamida no estudo da hepatocarcinogênese. / Morphological and molecular aspects of the experimental model of thioacetamide in the study of hepatocarcinogenesis.

Portela, Tânia Cristina Lima 17 April 2015 (has links)
O carcinoma hepatocelular (CHC) é a principal causa de morte em pacientes com cirrose hepática. O prognóstico para o CHC é muito pobre; trata-se de um tumor agressivo que progride rapidamente e, portanto, o diagnóstico precoce é o único meio de aumentar a sobrevida dos pacientes. O presente estudo sugere a tioacetamida (TAA) como modelo experimental de carcinogênese no microambiente cirrótico e busca identificar os mecanismos iniciais do desenvolvimento tumoral durante a cirrose. Neste trabalho, ratos Wistar machos foram injetados com TAA i.p. 3 vezes/semana por 14, 21 e 35 semanas. Foram examinados os efeitos sobre a função hepática, morfologia, desenvolvimento e características de lesões pré-neoplásicas (LPNs), bem como expressão tecidual e gênica dos marcadores tumorais mais comuns no CHC. O tratamento com TAA promoveu alterações que compreenderam a deposição de tecido cicatricial com desenvolvimento de cirrose hepática, inflamação, aumento da proliferação celular e da apoptose, desenvolvimento de LPNs e modificações na expressão dos marcadores tumorais. As alterações celulares e estruturais do tecido hepático resultaram em redução do ganho de peso dos animais e aumento do peso e do volume do fígado, proporcional ao tempo de tratamento. O índice de atividade histológica foi maior no fígado cirrótico e alcançou maior valor após 35 semanas de tratamento. Marcadores sanguíneos de lesão hepática aumentaram nos animais tratados ao passo que os marcadores de função mostraram melhora com o passar do tempo. Os níveis de alfa-fetoproteína foram maiores após 14 semanas de tratamento. A administração de TAA por 21 semanas resultou em maior número de LPNs, com predomínio de lesões persistentes sobre remodelantes em número e tamanho. A proliferação celular foi exacerbada nos fígados cirróticos sendo mais elevada em 14 semanas e apresentando redução significativa após 35 semanas. O número de corpúsculos apoptóticos foi maior no tecido cirrótico e a apoptose foi mais pronunciada em 21 semanas. O painel imuno-histoquímico composto por GPC3, HSP70 e GS demonstrou maior positividade para a combinação HSP70+GS, uma vez que a expressão de GPC3 foi baixa em todos os grupos. A análise dos marcadores moleculares GPC3, survivina e LYVE1 concordou com os resultados das LPNs. A expressão gênica de survivina foi maior em 14 semanas, quando foi observada também maior proliferação, e diminuiu ao longo do tratamento. A expressão de LYVE1 diminuiu nos grupos de 14 e 21 semanas, porém, foi significativamente elevada em 35 semanas. A partir desses resultados, concluímos que o modelo da TAA foi adequado para a indução de cirrose e para o desencadeamento da hepatocarcinogênese. As fases de iniciação e promoção foram identificadas em todos os períodos avaliados, entretanto, a TAA mostrou-se uma importante ferramenta para a fase de promoção aumentando a proliferação celular e o tamanho das LPNs. O tratamento por 21 semanas foi o mais eficaz em aliar a iniciação e promoção da hepatocarcinogênese, como mostrado pelo número e pelo tamanho das lesões. Contudo, nenhum grupo desenvolveu CHC indicando que a TAA, provavelmente, necessita ser associada com outras substâncias tendo em vista seu principal efeito como agente promotor. / Hepatocellular carcinoma (HCC) is the main cause of death in patients with liver cirrhosis. The prognosis for HCC is very poor; it is an aggressive tumor that progresses rapidly and therefore early diagnosis is the only way to increase the survival of these patients. This study suggests the thioacetamide (TAA) as experimental model of carcinogenesis in cirrhotic microenvironment and seeks to identify the initial mechanisms of tumor development during cirrhosis. In this study, male Wistar rats were injected ip with TAA 3 times / week for 14, 21 to 35 weeks. We examined the effects on liver function, morphology, characteristics and development of preneoplastic lesions (PNLs), as well as tissue gene expression and the most common tumor markers in HCC. Treatment with TAA made changes that comprised the deposition of scar tissue in the liver cirrhosis, inflammation, increased cell proliferation and apoptosis, PNLs development and changes in the expression of tumor markers. The cellular and structural changes of the liver tissue resulted in reduced weight gain of the animals and an increase in liver weight and volume proportional to the treatment time. The histological activity index was higher in cirrhotic liver and achieved greater value after 35 weeks of treatment. Blood markers of liver damage in the treated animals increased while the function markers showed improvement over time. The alpha-fetoprotein levels were higher after 14 weeks of treatment. The administration of TAA for 21 weeks resulted in a greater number of PNLs, with a predominance of persistent lesions over remodeling lesions in number and size. Cell proliferation was exacerbated in cirrhotic livers and was higher in 14 weeks with a significant reduction after 35 weeks. The number of apoptotic corpuscles was higher in cirrhotic tissue and apoptosis was more pronounced in 21 weeks. Immunohistochemical panel of GPC3, HSP70 and GS showed higher rates of HSP70 + GS combination, since GPC3 expression was low in all groups. The analysis of molecular markers GPC3, surviving, and LYVE1 agreeded with the results obtained in the PNLs. Survivin gene expression was higher in 14 weeks, when it was observed also increased proliferation and decreased during treatment. The expression of LYVE1 decreased in groups of 14 and 21 weeks, however, was significantly higher in 35 weeks. From the results obtained, we conclude that the TAA model was suitable for induction of cirrhosis and the onset of hepatocarcinogenesis. The stages of initiation and promotion were identified in all periods, however, the TAA proved to be an important tool for the promotion phase increasing cell proliferation and size of PNLs. Treatment for 21 weeks was more effective in combining the initiation and promotion of hepatocarcinogenesis, as shown by the number and size of the lesions. However, no group has developed HCC indicating that the TAA probably needs to be associated with other substances because its primary effect is like promoting agent.
49

Modulação do óxido nítrico no choque séptico: estudo experimental dos efeitos hemodinâmicos e inflamatórios do tratamento com doador de óxido nítrico (nitroprussiato) e inibidor da enzima óxido nítrico sintase induzida (1400W) em suínos submetidos ao choque séptico / Modulation of nitric oxide in septic shock: an experimental study of hemodynamic and inflammatory effects of treatment with nitric oxide donor (nitroprusside) and inducible nitric oxide synthase enzyme inhibitor (1400W) in pigs subjected to septic shock

Monteiro Filho, Adalberto 27 January 2011 (has links)
Introdução: Apesar de todos os esforços, as taxas de mortalidade na sepse ainda são inaceitavelmente altas, por isso, é importante a busca por novos tratamentos. O óxido nítrico tem um papel fundamental na fisiopatologia da sepse e sua modulação poderia ser uma alternativa de tratamento para algumas das complicações hemodinâmicas, de perfusão tecidual e inflamatórias desta síndrome. Objetivos: Avaliar o efeito do nitroprussiato e do inibidor da iNOs (1400W) nos parâmetros hemodinâmicos, de perfusão tecidual e na inflamação, em modelo experimental de choque séptico. Métodos: Utilizou-se 20 suínos anestesiados e monitorados através do cateter de artéria pulmonar, cateter de tonometria e cateter de artéria femoral. Eles foram randomizados e tratados da seguinte maneira. Sham - somente anestesia; Choque - anestesia, infusão de bactérias (E.coli, 4,5x109ufc/mL) e tratamento padrão (fluidos e noradrenalina, guiados pela PVC, PAM e SvO2); NO/iNOs mesmos tratamentos do Choque, associado ao tratamento específico com nitroprussiato e inibidor da iNOs. Foram avaliados parâmetros hemodinâmicos, de perfusão tecidual, ventilatórios, gasométricos e inflamatórios a cada 1 hora, a partir do Tbasal até 240 minutos. Resultados: Verificou-se alterações clínicas características da sepse, após a infusão de bactérias, como taquicardia, hipotensão arterial, depressão miocárdica, hipertensão pulmonar, aumento do lactato, comprometimento da perfusão tecidual regional e indução das citocinas pró-inflamatórias. A administração do nitroprussiato associado ao inibidor da iNOs ao grupo NO/iNOs, promoveu melhora significante em relação ao grupo Choque, com aumento do IC (6,0 ± 1,9 vs 4,1 ± 2,3 e p<0,024), da FE (31 ± 13 vs 17 ± 6 e p<0,001), do ITSVE (30 ± 8 vs 20 ± 9 e p<0,026) e do IVS (35 ± 13 vs 24 ± 11 p< 0,033) e diminuição da PAP (40 ± 6 vs 48 ± 6 p<0,001) e do IRVP (460 ± 148 vs 906 ± 405 p<0,001). A perfusão tecidual melhorou, com diminuição do PCO2 intestinal (83 ± 11 vs 94 ± 16 p<0,041), diferença entre o PCO2 intestinal/ arterial (38 ± 8 vs 55 ± 27 e p< 0,039) e aumento do pH intestinal (7,07 ± 0,06 vs 6,99 ± 0,09 p< 0,032), SvO2 (79 ± 6 vs 65 ± 12 p<0,002) e DU (167 ± 89 vs 66 ± 45 p<0,001). Houve melhora da são2 (97 ± 2 vs 93 ± 7 p< 0,027) e da IL1-&beta; (340 ± 147 vs 1306 ± 238 e p< 0,001).Discussão: o tratamento proposto melhorou a função cardíaca, oxigenação, perfusão tecidual e inflamação sem apresentar efeitos adversos. Conclusão: O modelo proposto foi representativo da sepse clínica e o tratamento com nitroprussiato e inibidor da iNOs melhorou a função do miocárdio, a hemodinâmica pulmonar, a perfusão tecidual e modulou a resposta inflamatória. / Introduction: Despite all efforts, the mortality rates in sepsis are still unacceptably high, so it is important to search for new treatments. Nitric oxide plays a key role in the pathophysiology of sepsis and its modulation could be an alternative treatment for some hemodynamic, tissue perfusion and inflammatory complications of this syndrome. Objectives: Evaluate the effect of nitroprusside and iNOs inhibitor (1400W) on hemodynamic, tissue perfusion and inflammation parameters, in an experimental model of septic shock. Methods: We used 20 anesthetized pigs and monitored them via the pulmonary artery catheter, tonometry catheter and the femoral artery catheter. They were randomized and treated as follows. Sham - anesthesia only; Shock - anesthesia, infusion of bacteria (E.coli, x109ufc/mL 4.5) and standard treatment (fluids and norepinephrine, guided by CVP, MAP and SvO2) NO/iNOs - same treatments of Shock, associated to specific treatment with iNOs inhibitor and nitroprusside. We evaluated hemodynamic, tissue perfusion, ventilation, blood gas and inflammatory parameters every 1 hour from Tbasal up to 240 minutes. Results: There were clinical changes typical of sepsis, after the infusion of bacteria, such as tachycardia, hypotension, myocardial depression, pulmonary hypertension, increase of lactate, impairment of regional tissue perfusion and induction of pro inflammatory cytokines. The administration of nitroprusside associated with the iNOs inhibitor to the NO/iNOs group, caused a significant improvement in relation to the Shock group, with increase of CI (6.0 ± 1.9 vs. 4.1 ± 2.3 p <0.024), EF (31 ± 13 vs 17 ± 6 p <0.001), LVSWI (30 ± 8 vs 20 ± 9 p <0.026) and SVI (35 ± 13 vs 24 ± 11 p <0.033) and decrease of PAP (40 ± 6 vs 48 ± 6 p <0.001) and PVRI (460 ± 148 vs 906 ± 405 p <0.001). The tissue perfusion improved, with a decrease of intestinal PCO2 (83 ± 11 vs 94 ± 16 p <0.041), intestinal/arterial PCO2 gap (38 ± 8 vs 55 ± 27 p <0.039) and increase of intestinal pH (7.07 ± 0.06 vs 6, 99 ± 0.09, p <0.032), SvO2 (79 ± 6 vs 65 ± 12 p <0.002) and urinary output (167 ± 89 vs 66 ± 45 p <0.001). There was improvement in SaO2 (97 ± 2 vs 93 ± 7 p <0.027) and IL1-&beta; (340 ± 147 vs. 1306 ± 238 p <0.001). Discussion: The proposed treatment improved cardiac function, oxygenation, tissue perfusion and inflammation without producing adverse effects. Conclusion: The proposed model was representative of clinical sepsis and the treatment with nitroprusside and iNOs inhibitor improved myocardial function, pulmonary hemodynamics, tissue perfusion and modulated the inflammatory response.
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Efeitos do esquema de intervalo variável na preferência e no consumo de líquidos apresentados por ratos submetidos ao chronic mild stress / The effects of variable interval schedule on preference and liquid consumption by rats subjected to chronic mild stress

Cardoso, Luciana Roberta Donola 14 May 2008 (has links)
Made available in DSpace on 2016-04-29T13:18:08Z (GMT). No. of bitstreams: 1 Luciana Roberta Donola Cardoso.pdf: 1323389 bytes, checksum: 152237ce34951aabd58677f712755d06 (MD5) Previous issue date: 2008-05-14 / The Chronic Mild Stress (CMS) is an experimental animal model of depression induced by the exposure of rats to a set of moderate and uncontrollable aversive stimuli in a long and uninterrupted period of time. The purpose of this study was to investigate the relationship between performance in variable interval schedule of behavior and exposure to the protocol of stress (daily consumption of food and water, changes in body weight, frequency of answers issued in each bar and the frequency of reinforcements obtained when submitted to the same scheme competitor). The study design was composed of three experimental conditions: test consumption and preferably liquid; sessions operating on schedule competitor VI 10 (water) VI 10 (sucrose) and protocol of stress (CMS). Six male rats were used. One subject was used to control weight, not involved in any of the three experimental conditions. Five subjects were submitted to the protocol of stress and tests of consumption and preference of liquids throughout the experiment. Two subjects were submitted to the working sessions (VI competitor VI) before and after CMS and two subjects were submitted to the working sessions before, during and after the CMS. The results were: 1) all subjects showed loss of body weight during the exposure to stressors. 2) The four subjects submitted to the working sessions showed recovery of body weight after the suspension of the protocol. 3) All subjects showed an increase in daily consumption of water and feed during the CMS, despite the loss of weight in this period. 4) Liquid consumption and the percentage of sucrose intake was higher during the CMS for the four subjects submitted to the working sessions, featuring a reduction in the last week of exposure to the protocol of stress. 5) All subjects expressed a greater number of responses in the bar corresponding to sucrose before exposure to CMS. Meanwhile, during and after CMS, a preference for water became outstanding. 6) The subjects received almost all of the planned reinforcements of both magnitudes (sucrose solution or pure water) in the three periods of assessment. We conclude that: 1) the loss of weight during the CMS seems to be related to the combination of aversive stimuli compound by the Protocol of stress and deprivation of water and food intermittent making up this protocol 2) the increase in the total consumption of liquids during the CMS appear to be related to the submission to the working sessions in variable interval before submission to the Protocol 3) the exposure of the subject to a scheme of variable interval, before CMS, slows the decline in the consumption of liquid and increases consumption of fluids during the CMS / O Chronic Mild Stress (CMS) é um modelo animal experimental de depressão induzida por meio da exposição de ratos a um conjunto de estímulos aversivos moderados e incontroláveis, apresentados por um longo e ininterrupto período de tempo. O objetivo deste estudo foi investigar a possível relação entre o desempenho em esquema de intervalo variável e a exposição ao protocolo de estresse, quanto ao consumo diário de ração e água e as subseqüentes alterações no peso corporal; no consumo e na preferência de líquidos; na freqüência de respostas emitidas em cada barra e na freqüência de reforços obtidos nas mesmas quando submetidos ao esquema concorrente. O delineamento foi composto por três condições experimentais: teste de consumo e de preferência de líquidos; sessões operantes em esquema concorrente VI 10 (água) VI 10 (sacarose) e protocolo de estresse (CMS). Foram utilizados seis ratos machos, sendo que um sujeito foi utilizado para controle de peso, não submetido a nenhuma das três condições experimentais. Cinco sujeitos foram submetidos ao protocolo de estresse e aos testes de consumo e preferência de líquidos durante todo o experimento. Dois sujeitos foram submetidos às sessões operantes (concorrente VI VI) antes e depois do CMS e dois sujeitos foram submetidos às sessões operantes, antes, durante e depois do CMS. Os resultados obtidos foram: 1) todos os sujeitos apresentaram perda de peso corporal durante a exposição aos estressores. 2) Os quatro sujeitos submetidos às sessões operantes apresentaram recuperação do peso corporal após a suspensão do protocolo; 3) todos os sujeitos apresentaram aumento no consumo diário de água e ração durante o CMS, apesar da perda de peso neste período; 4) consumo total de líquidos e a porcentagem de sacarose ingerida foi maior durante o CMS para os quatro sujeitos submetidos as sessões operantes, apresentando uma redução na última semana de exposição ao protocolo de estresse; 5) todos os sujeitos emitiram um maior número de respostas na barra correspondente a sacarose antes da exposição ao CMS. Entretanto, durante e depois do CMS a preferência por água se tornou sobressalente; 6) os sujeitos obtiveram a quase totalidade de reforços programados de ambas as magnitudes (solução de sacarose ou água pura ) nos três períodos de avaliação. Conclui-se que: 1) a perda de peso corporal durante o CMS parece estar relacionada à combinação dos estímulos aversivos compostos pelo protocolo de estresse e à privação de água e ração intermitente que compõem este protocolo 2) o aumento no consumo total de líquidos durante o CMS parecem estar relacionados à submissão às sessões operantes em intervalo variável antes da submissão ao protocolo 3) a exposição dos sujeitos a um esquema de intervalo variável, antes do CMS, não só teria um efeito de retardar a diminuição no consumo de líquidos, como aumentar o consumo de líquidos durante o CMS

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