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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.
1

COPLANAR PCB77 AND ANGII INDUCED VASCULAR DISORDERS

Parulkar, Madhura 01 January 2012 (has links)
Previous studies demonstrated that coplanar PCBs promote inflammation by release of pro-inflammatory cytokines like TNF, MCP-1, and VCAM-1 from endothelial cells as well as adipocytes. Also these PCBs at small doses may contribute to the development of obesity by inducing adipocyte differentiation. Obesity is a known risk factor that promotes cardiovascular disorders like atherosclerosis and AAAs. Evidence shows Ang II, a component of the RAS, leads to the formation of atherosclerosis and AAAs in both normal as well as hyperlipidemic mice. Earlier studies in our laboratory have also shown that coplanar PCB-77 promotes atherosclerotic lesion formation in ApoE-/- mice. The purpose of this study was to define the effects of PCB77 on Ang II induced vascular diseases like atherosclerosis and AAAs. Two different hyperlipidemic mouse models, which require different diets to get atherosclerosis, the ApoE deficient mice (ApoE-/-) requiring the normal mouse diet (Chow diet) and the Low Density Lipoprotein Receptor deficient mice (LDLr-/-) requiring the Western diet, were used for this study as both are susceptible to Ang II induced vascular disorders. The timing of PCB administration was also studied in LDLr-/- mice to see the profound effects of PCB77 on atherosclerosis and AAAs.
2

Efecto de la atorvastatina sobre la enfemedad grasa del hígado inducida en pollos mediante una dieta aterogénica

Martín Castillo, Antonia 27 February 2008 (has links)
Este trabajo valora el efecto de la dieta y el tratamiento con atorvastatina sobre la EGHNA inducida en pollos mediante una dieta hiperlipémica, empleando técnicas de análisis bioquímico, histológico, microscopía electrónica, técnicas inmunocitoquímicas y cuantificaciones histológicas. Utilizamos 100 pollos de la raza White Leghorn, se dividieron al azar en dos grupos control e hiperlipémico en una primera fase de inducción de hígado graso (3 meses) y en una segunda fase de otros 3 meses los animales hiperlipémicos fueron divididos en los grupos de progresión con dieta hiperlipémica, regresión, regresión farmacológica y progresión farmacológica. La retirada de la dieta y/o el tratamiento con atorvastatina reduce la esteatosis hepática, la inflamación y la lesión hepatocelular. Se constata una mayor actividad de la enfermedad en los grupos de progresión respecto a los de regresión y una menor actividad en los animales tratados respecto a los no tratados. / The aim of the present study was to determinate the effect of diet and atorvastatin on NAFLD induced by hyperlipidemic diet in experimental animals. We carried out serum biochemical analysis, histology, electron microscopy and immunohistochemical techniques and histological quantifications. We used one-hundred white Leghorn chickens. The chickens were randomly assigned to 2 Kinds of diet: a standard diet and a hyperlipidemic diet. After a three-month induction period the chickens were randomly divided in four groups and were breeding for another three-month period with different diets. Thus, the groups of our study were as follows: healthy control, hyperlipidemic progression, spontaneous regression, pharmacological regression and pharmacological progression.The removal diet and/or atorvastatin treatment decreased the steatosis, inflammation and hepatocelular lesion grade in the liver. We have observed a greater NASH Activity Score in progression groups than regression groups and lower activity in the treatment groups with regard to non-treated groups.
3

Efeitos do ômega-3 na parede arterial de coelhos albinos (Oryctolagus cuniculus) submetidos à aterosclerose experimental / Effects of omega-3 in the arterial wall of rabbits (Oryctolagus cuniculus) underwent experimental atherosclerosis

Martins, Josefa Sileda 17 June 2011 (has links)
The nutraceutical omega 3 fatty acid, which has been used to prevent cardiovascular disease; on the other hand, atherosclerosis is the leading cause of morbidity and mortality, becoming myocardial infarction and strokes the main consequences. Objective: This study aimed to verify the preventive effects of omega-3 in the formation of atherosclerosis, inducing hyperlipidemic diet in rabbits to quantify the atherosclerotic involvement of the arterial lumen and to evaluate serum lipid levels (total cholesterol, fractions, triglycerides and HDL). Methods: 21 male rabbits New Zealand white race were randomized into three groups with seven animals, namely: control group (G1) where the animals received food and water ad labium; group hyperlipidemic (G2) food and water ad labium, 20 ml of chicken egg yolk divided in two doses and treated group (G3) that in addition to 20 ml of yolk, ingested 221 mg / kg body weight of omega-3 as well as food and water ad labium. The blood was collected to determine serum and after 99 days of the experiment, animals were euthanized for removal of debris following: aortic arch, right common carotid artery and right femoral artery. The results were compared using statistical methods of ANOVA, and Kolmogorov-Smirnorv. Results: There was no decrease in serum total cholesterol and fractions, and triglyceride did not increase HDL. There was thickening of the sub endothelial layer and formation of foam cells in G1 and G2. Conclusion: The Omega has no preventive effect in reducing atherosclerotic plaques; there was increased in the arterial lumen at 57.55%. / Fundação de Amparo a Pesquisa do Estado de Alagoas / O ômega-3 é um ácido graxo nutracêutico, que tem sido utilizado para prevenir as doenças cardiovasculares, das quais a aterosclerose é a principal causa de morbidade e mortalidade, tornando o infarto do miocárdio e o acidente vascular encefálico suas principais consequências. Objetivo: Este trabalho teve como objetivos verificar a existência de efeitos preventivos do ômega-3 na formação da doença aterosclerótica, através da indução de dieta hiperlipidêmica em coelhos, quantificar o comprometimento aterosclerótico da luz arterial bem como, analisar os níveis lipídicos séricos (colesterol total, frações, triglicerídeo e HDL). Material e Método: 21 coelhos albinos, machos da raça Nova Zelândia foram distribuídos aleatoriamente em três grupos com sete animais, a saber: Grupo Controle (G1) cujos animais receberam ração e água ad libitum; Grupo Hiperlipidêmico (G2) ração e água ad libitum, mais 20 ml de gema de ovo de galinha em dividida em duas tomadas e o Grupo Tratado (G3) que além dos 20 ml de gema, ingeriu 221 mg/kg/peso de ômega-3, bem como ração e água ad libitum. O sangue foi coletado para verificar os níveis séricos e após 99 dias de experimento, os animais foram submetidos à eutanásia para retirada dos seguintes fragmentos: arco aórtico, artéria carótida comum direita e artéria femoral direita. Os resultados foram comparados pelos métodos estatísticos ANOVA, e teste de Kolmogorov-Smirnorv. Resultados: Não houve diminuição dos níveis séricos do colesterol total, e frações, o triglicerídeo e não aumentou o HDL. Houve espessamento da camada subendotelial e formação de células espumosas, nos grupos G1 e G2. Conclusão: O ômega não tem efeito preventivo na redução das placas ateromatosas, houve aumento do comprometimento da luz arterial em 57,55%.
4

Des lapins watanabe au syndrome hyper IgE humain : caractérisation précoce de l'athérosclérose utilisant une probe optique ciblant l'integrin aVb3 / From Watanabe Rabbits to Human Hyper IgE Syndrome : Characterization of Early Atherosclerosis Using a High Affinity αvβ3 Integrin Targeted Optical Probe

Héroux, Julie 20 December 2012 (has links)
La détection précoce de l’athérosclérose, avant le développement de ses séquellespathologiques, comme l’infarctus du myocarde, l’angine ou l’accident cérébrauxvasculaire(ACV), représente un important défi au niveau de la médecine diagnostiqueactuelle. Malgré les récentes avances technologiques, les maladies cardiovasculairesdemeurent la principale cause de décès dans les pays occidentaux et la détection à unstage plus précoce s’avère nécessaire pour permettre une intervention thérapeutiqueadéquate. Notre étude se concentre sur la détection de l’athérosclérose, plusspécifiquement la vulnérabilité de la plaque, grâce à l’imagerie moléculaire combinée àl’observation pathologique. Afin de prédire la rupture de la plaque, l’imageriemoléculaire a émergé comme outil diagnostique puissant suite au développementcroissant de sondes ayant de l’affinité pour les molécules cibles du processusd’athérosclérose. Comme résultantes, ces molécules sélectives possédant une forteaffinité pour des cibles surexprimées durant le processus de formation de la plaque,comme l’αvβ3 par exemple, devrait représentées des sondes prometteuses pour ladétection de l’athérosclérose.Objectif L’objectif global de notre étude était d’évaluer et de prédire lavulnérabilité de la plaque d’athérome à l’aide de différents marqueurs moléculaires. Leprincipal objectif de notre recherche était d’évaluer la possibilité de détecter précocementla plaque en utilisant une ITOP (integrin targeted optical probe). Cette sonde synthétiquenouvellement développée et ciblant l’intégrine αvβ3 avait déjà démontré une affinité etspécificité particulièrement élevée pour le récepteur de l’αvβ3 dans le cancer. Nousavons également exploré la relation entre cette sonde et l’observation pathologique desplaques d’athéromes sur le modèle animale WHHL et sur des plaques humainesprovenant de différents patients.Procédure et Résultats Les expériences ont été réalisées sur un total de 12 lapinsWatanabe hyperlipidémiques de souche WHHL (Watanabe heritable hyperlipidemic) et 1lapin contrôle NZW (New Zealand White). Premièrement, notre ITOP, marquée avec lafluorescéine isothiocyanate (FITC), a été utilisée pour détecter in vitro et ex vivo laprésence du récepteur de l’αvβ3. La microscopie à fluorescence a révélé un importantmarquage de la plaque d’athérome, lequel était absent dans les tissus provenant des lapinscontrôles NZW. Le marquage a été détecté au niveau de segments de plaques provenantde deux régions distinctes de l’aorte ascendante et descendante dans chaque lapin. Lesignal a été détecté principalement au niveau de l’adventitia et de l’intima proximale desvaisseaux aortiques, correspondant directement à l’expression de l’intégrine αvβ3,déterminée par essai immunochimique avec un anticorps contre l’αvβ3. De plus, uneforte association s’est révélée entre le niveau de marquage de la sonde ciblant l’αvβ3 etl’épaisseur de l’adventitia. Deuxièmement, nous avons évalué notre sonde sur deséchantillons humains affectés par l’athérosclérose et comparé les résultats avec uneévaluation morphologique. Nous avons remarqué la même tendance que chez le lapin, soiun marquage plus important lorsque l’adventitia s’épaissi. Finalement, nous avons testé lasonde sur des artères coronaires provenant d’une autopsie d’un patient affecté par le ADHIESet comparé les résultats avec l’évaluation morphologique de leurs artèrescoronaires. Nous avons trouvé un lien entre la morphologie de la plaque et la prévalenced’anévrysmes coronaires chez ces patients.Conclusion L’expression de l’αvβ3 est reliée à la foi aux processus inflammatoires età la sténose. Notre ITOP à marqué efficacement in vitro le premier type de plaqued’athérome classé comme avancé (type IV) et pouvant produire des manifestationscliniques. En combinaison avec l’imagerie noninvasive détectant la sténose, il pourraits’avéré utile dans la détection de la plaque vulnérable. / Purpose The detection of early atherosclerosis, before the development of its later sequelae of myocardial infarction, angina or stroke, constitutes an important challenge in current diagnostic medicine. Despite all the recent technological advances, cardiovascular disease remains the leading cause of death in the Western World and needs to be detected at an earlier stage to allow for more timely therapeutic intervention. This study is focusing on the detection of atherosclerosis or more specifically plaque vulnerability with the help of molecular imaging and pathological observation. Effectively, to predict plaque rupture, molecular imaging has emerged as a powerful diagnostic tool, consequent to the development of a growing number of new probes with affinity for key molecular targets. As a result, such selective molecule with high affinity for overexpressed target in plaque formation, as αvβ3 integrin, should have promise as a probe for imaging atherosclerosis. With the help of molecular imaging combined with pathological observations, we can better comprehend, predict, and detect plaque vulnerability and rupture. Objectives The overall objective of this study is to evaluate different molecular tools to predict the vulnerability of the atheromatous plaque. The major objective of the research was to investigate the possibility of detecting atherosclerotic plaque by using a newly developed synthetic αvβ3 integrin targeted optical probe (ITOP) showing particularly high affinity and specificity for the αvβ3 receptor. We also investigate the relation between this probe and pathological observation of atherosclerotic plaques from WHHL animal model and different human samples. Procedures and Results For this study, experiments were performed on 12 Watanabe heritable hyperlipidemic (WHHL) rabbits and 1 New Zealand White (NZW) rabbits for control. First, our ITOP labeled with fluorescein isothiocyanate was used for detecting the presence of αvβ3 receptors in vitro and ex vivo on a Watanabe rabbit model. Fluorescence microscopy demonstrated a strong labeling of atherosclerotic plaques, which was absent in tissue from normal NZW rabbits. Segments of plaque accumulation from two distinct regions of ascending and descending aortas were labeled in each rabbit. The signal was found principally in the adventitia and proximal intima of the aortic vessel, corresponding directly to the expression of integrin αvβ3 as determined by antibody assay. Moreover, there was a close association between the level of labeling with the αvβ3 targeted probe and the thickness of the adventitia. Secondly, the ITOP was evaluated on human atherosclerotic samples, and was found to efficiently labeled atherosclerotic plaques. Moreover, we observed the same tendency as in the Watanabe rabbit: the ITOP intensity correlated with the degree of adventitial thickening. Finally, we tested the ITOP on Job's Syndrome coronary arteries, and have been able to detect a plaque corresponding to the first type of advanced atherosclerosis (type IV). We also found a relationship between plaque morphology and predisposition to aneurysms in Job's syndrome. Conclusions αvβ3 expression is related to inflammatory and stenotic processes. Our ITOP can efficiently label in vitro the first type of advanced atherosclerotic plaque. In combination with noninvasive imaging techniques that evaluate stenosis, it has great potential for the detection of vulnerable plaque.

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