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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.
241

Effets cardioprotecteurs du glutamate contre les lésions d'ischémie-reperfusion myocardique chez la souris. Evaluation échocardiographique. / Cardioprotective effects of glutamate against ischemia-reperfusion injury in the mouse heart. Echocardiographic evaluation

Sportouch-Dukhan, Catherine 30 November 2012 (has links)
L'infarctus du myocarde est la première cause de mortalité cardiovasculaire dans les pays occidentaux. La reperfusion la plus précoce possible est actuellement le seul traitement validé pour réduire la taille d'infarctus, facteur pronostique fondamental de morbi-mortalité. Cependant, la reperfusion engendre des lésions d'ischémie-reperfusion (IR) irréversibles qui précipitent la mort par apoptose des cardiomyocytes. Une approche transcriptomique nous a permis d'identifier les gènes spécifiques du postconditionnement ischémique (PostC) dans le cœur de souris. Parmi ceux-ci, l'expression du gène codant pour le récepteur métabotrope de type 1 du glutamate (mGluR1) est augmentée par le PostC. L'objectif de mon travail de thèse a été d'étudier le rôle de mGluR1 au cours de l'IR myocardique. Notre stratégie, basée sur l'utilisation de souris knock-out, a permis de confirmer l'implication de mGluR1 dans la cardioprotection. L'injection de glutamate au moment de la reperfusion myocardique permet de diminuer significativement la taille de l'infarctus par inhibition de l'apoptose. Cet effet cardioprotecteur est diminué en présence de l'antagoniste spécifique YM 298198 ou en présence de wortmannin, inhibiteur de la PI3-kinase, activée dans la cascade de signalisation du récepteur. La réduction de la taille d'infarctus par le glutamate semble associée à une amélioration de la fonction contractile du ventricule gauche en échocardiographie (par speckle tracking, méthode de quantification de la déformation myocardique) dans un modèle murin d'IR myocardique. Ces résultats, bien que préliminaires, semblent prometteurs et nous permettent d'envisager une application clinique chez le patient coronarien. / Myocardial infarction is the major cause of cardiovascular mortality in western countries. Reperfusion as early as possible is the only treatment recognized to reduce infarct size, crucial prognostic factor of morbidity and mortality. However, reperfusion leads to ischemia-reperfusion (IR) injury leading to irreversible apoptotic death of cardiomyocytes. A transcriptomic approach has allowed us to identify genes specifically regulated upon ischemic postconditioning (PostC) in the mouse heart. Among them, the expression of the metabotropic glutamate receptor type 1 (mGluR1) gene is up-regulated by PostC. The aim of my thesis work was to study the role of mGluR1 during myocardial IR. Our strategy, based on the use of knockout mice, confirmed the involvement of mGluR1 in cardioprotection. Injection of glutamate at the time of reperfusion significantly reduced infarct size via apoptosis inhibition. This cardioprotective effect was reduced in presence of the specific antagonist YM 298198 or in presence of wortmannin, an inhibitor of PI3-kinase, which is activated downstream mGluR1. In our mouse model of myocardial IR injury, decrease in infarct size after glutamate treatment seems to be associated to an improved left ventricular contractile function assessed by echocardiography (speckle tracking method quantifying myocardial strain). These preliminary results are promising and allow us to consider a clinical trial for coronary patients.
242

Etude de la cardioprotection contre l'infarctus du myocarde au cours de l'obésité expérimentale / Study of the cardioprotection against myocardial infarction during experimental obesity

Bouhidel, Jalaleddinne Omar 16 December 2010 (has links)
L'infarctus du myocarde (IDM) est l'une des principales causes de morbi-mortalité dans les pays développés et ce malgré l'amélioration enregistrée ces dernières années dans sa prise en charge thérapeutique. L'obésité est classée comme étant un facteur de risque majeur pour les maladies coronaires par l'American Heart Association, et concerne 14,5 % de la population française (enquête ObEpi-Roche/INSERM, 2009). En utilisant un modèle expérimental d'obésité, la souris ob/ob génétiquement dépourvue en leptine, l'objectif du présent travail de thèse a été d'étudier l'efficacité de stratégies cardioprotectrices comme le postconditionnement (PCD) ischémique ou l'exercice physique chronique contre l'IDM. La première partie de ce travail de thèse a mis en évidence une perte de la cardioprotection par PCD ischémique au cours de l'obésité. L'étude des voies de signalisation aura permis de mettre en évidence l'implication des protéines phosphatases PTEN, MKP3 et PP2C dans l'inefficacité du PCD. La seconde partie de ce travail de thèse a montré un effet cardioprotecteur de l'exercice physique chronique contre l'IDM dans un contexte expérimental d'obésité. Cet effet est associé à une augmentation des défenses enzymatiques antioxydantes, à une amélioration des fonctions mitochondriales, à une activation des voies de signalisation cardioprotectrices RISK et SAFE et enfin à une diminution des protéines phosphatases impliquées dans la régulation négative des acteurs des voies de signalisation cardioprotectrices. La preuve scientifique des bienfaits de l'exercice est aujourd'hui un argument de poids pour poursuivre les efforts entrepris par les pouvoirs publics ces dernières années à travers le Programme National Nutrition Santé pour favoriser la pratique d'une activité physique et sportive et en particulier chez les obèses. / Myocardial infarction (MI) remains the leading cause of morbidity and mortality in the developing countries despite significant therapeutic advances over these last years. Obesity is a major risk factor for coronary heart disease according to the American Heart Association and concern 14.5% of the French population (ObEpi-Roche/INSERM survey, 2009). Using the leptin-deficient ob/ob mice, an animal model of obesity, the aim of the present thesis was to investigate the efficacy of cardioprotective strategies such as ischemic postconditioning (PCD) or chronic physical exercise against MI. In the first part of this thesis, we have found that the cardioprotective effects of PCD vanish with obesity. The investigation of the cardioprotective pathways has revealed that protein phosphatases such as PTEN, MKP3 and PP2C are involved in the inability of PCD to protect the heart. The second part of this thesis has demonstrated for the first time a cardioprotective effect of chronic physical exercise against MI in an experimental model of obesity. This effect was associated with increased antioxidant enzymes, improved mitochondrial function, activation of the cardioprotective RISK and SAFE pathways and finally a decrease in the related protein phosphatases levels. The scientific proofs given by this work underlines the “Programme National Nutrition Santé” developed by the French government to encourage all people and especially obese people to observe physical and sport activities.
243

Influência da Miostatina na Função Muscular, Tempo de Internação e Mortalidade de Pacientes com Infarto Agudo do Miocárdio com Supradesnivelamento de Segmento ST

Oliveira, Paula Gabriela Sousa de January 2019 (has links)
Orientador: Marcos Ferreira Minicucci / Resumo: Introdução: As doenças cardiovasculares são as principais causas de mortalidade em todo o mundo. O infarto agudo do miocárdio com supradesnivelamento de segmento ST (IAMCSST) vem apresentando redução da mortalidade após a introdução das terapias de reperfusão. Diversos fatores estão associados a pior prognóstico e foi evidenciado que massa e função muscular podem estar associadas a comorbidades como hipertensão arterial sistêmica, síndrome metabólica, diabetes mellitus, obesidade e morte precoce. A força e massa muscular são regulados por diversos fatores entre os quais podemos destacar a miostatina. A miostatina, conhecida classicamente como regulador negativo da musculatura tem apresentado papel controverso na literatura, sendo por vezes relacionada a perda de massa muscular. Até o presente momento não há estudos investigando o papel da miostatina nas síndromes coronarianas agudas. Objetivo: O objetivo do presente estudo é avaliar a associação dos valores séricos de miostatina, com a massa e função muscular, tempo de internação e mortalidade hospitalar de pacientes com IAMCSST admitidos no Hospital das Clínicas da Faculdade de Medicina de Botucatu. Materiais e métodos: Trata-se de um estudo prospectivo observacional com pacientes admitidos com diagnóstico de IAMCSST no Hospital das Clínicas da Faculdade de Medicina de Botucatu, no período de maio de 2018 a fevereiro de 2019. Foram incluídos pacientes com IAMCSST, que aceitaram participar e foram recrutados nas primeiras 48 ... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
244

Participação da resposta inflamatória induzida por Chlamydophila pneumoniae e Mycoplasma pneumoniae no infarto agudo do miocárdio / Participation of the inflammatory response induced by Chlamydophila pneumoniae and Mycoplasma pneumoniae in acute myocardial infarction

Lima Neto, Lídio Gonçalves 03 June 2011 (has links)
Os agentes infecciosos têm sido considerados iniciadores da desestabilização da placa de ateroma. Este mecanismo pode estar relacionado a uma intensificação do processo inflamatório através da interação dos receptores de membrana CD14 e TLR com os microorganismos. Para avaliar esta hipótese, estudou-se a participação da resposta inflamatória induzida por Chlamydophila pneumoniae (Cp) e Mycoplasma pneumoniae (Mp) em indivíduos com infarto agudo do miocárdio (IAM). Avaliou-se também, a possível associação entre polimorfismos dos genes CD14, TLR2, TLR4 e TNFA e a expressão dos genes IL6, TLR2, TLR4 e TNFA em leucócitos do sangue periférico, assim como a sua associação com o IAM. Para isso, foi realizado um estudo caso-controle constituído por pacientes com IAM e por indivíduos sem evidência de doença cardiovascular (grupo controle). As imunoglobulinas IgM e IgG séricas anti-Cp foram detectadas por imunofluorescência indireta. O DNA dos agentes infecciosos foi detectado no sangue periférico pela PCR em tempo real. A genotipagem dos polimorfismos TNFA -308G>A, IL6 -174G>C, CD14 -260C>T, TLR4 (Asp299Gli e Thr39911e) e TLR2 Arg753Gln e a quantificação relativa da expressão gênica nas células sanguíneas foram analisados pela PCR em tempo real. A porcentagem de positividade para DNA de Cp foi de 18,0% e 8,1% nos grupos IAM e controle (p=0,071), respectivamente, (p=0,071). Foram positivos para DNA de Mp, 5,0% e 11,2% dos indivíduos nos grupos IAM e controle, respectivamente (p=0,318). Sete indivíduos (7,1%) do grupo IAM tiveram títulos anti-Cp IgG positivos (1:512) e 3,9% dos indivíduos do grupo controle (p=0,718). A expressão do TLR4 foi significantemente menor no grupo IAM (0,00113±0,00102) comparado ao grupo controle (0,00144±0,000806; p=0,003). As frequências genotípicas e alelicas dos polimorfismos TNFA -308G>A, CD14 -260C>T, TLR4 (Asp299GIi e Thr39911e) e TLR2 Arg753Gln foram similares entre os grupos estudados (p>0,05) sugerindo que esses polimorfismos não estão associados com IAM nesta amostra populacional. No grupo IAM, houve associação entre o genótipo -260CT+TI CD14 com títulos IgG anti-Cp detectados na diluição 1:16 (p=0,042). Da mesma forma, o alelo A do polimorfismo -308G>A TNF-α foi associado com títulos positivos de IgG anti-Cp na diluição 1:512 (p=0,0058). No grupo IAM, pacientes positivos para DNA de Cp tiveram maiores concentrações de fibrinogênio do que pacientes negativos para este agente infeccioso (541,8±161,5mg/dL e 450,5±196,8mg/dL, respectivamente; p=0.043). Os agentes infecciosos Chlamydophila pneumoniae e Mycoplasma pneumoniae não foram significantemente mais frequentes em indivíduos que tiveram infarto agudo do miocárdio em relação ao grupo controle, porém houve uma associação, no grupo IAM, entre positividade para DNA de C. pneumoniae e concentrações mais elevadas de fibrinogênio. / Atheroma plaque instability has been attributed to the presence of some infectious agents. This mechanism may be related with increased stimulus of inflammatory process through interactions of CD14 and TLR with infectious agents. In this present study, it was evaluated the association of the presence of Chlamydophila pneumoniae and Mycoplasma pneumonia with acute myocardial infarction (AMI). A case-control study was conducted with AMI patients and non-AMI individuais as controls. Immunoglobulin G (lgG) and IgM antibodies anti-Chlamydophila pneumoniae were detected by indirect immunifluorescent assay and the Cp DNA and Mp DNA were detected by real time PCR (RT-PCR) in peripheral blood cells. Using the same method, the individuals were genotyped and the gene expressions of TLR2, TLR4, IL-6 e TNF-α were evaluated by RT-qPCR. In AMI patients, Cp DNA and Mp DNA were positive in 18,0% and 5,0% samples, respectively. In controls, 8,1% and 11,2% were positive for Cp DNA and Mp DNA, respectively. TLR4 expression was significantly decreased in AMI patients (0.00113±0.001 02) compared with controls (0.00144±0.000S06; p=0.003). The frequencies of -308G>A TNF-α., -260C>T CD14, Asp299Gli TLR4, Thr39911e TLR4e Arg753Gln TLR2 SNPs in AMI group were similar to those found in controls. On the other hand, In AMI group, the -260CT+TT CD14 genotype was associated with anti-CP IgG antibody titer of 1/16. Likewise, the rare allele of -308G>A TNF-α was associated with anti-CP IgG antibody titer of 1/16. Cp DNA positive patients had high concentration of fibrinogen when compared with negative patients. In conclusion, Cp DNA and Mp DNA positivity were not associated with AMI.
245

"Fatores de risco em pacientes com infarto agudo do miocárdio em um hospital privado de Ribeirão Preto-SP" / Risk factors in patients with myocardial infarction in a Ribeirão Preto’s private hospital

Oliveira, Kelli Cristina Silva de 27 April 2004 (has links)
No Brasil, as doenças cardiovasculares constituem-se nas principais causas de mortalidade, sendo o infarto agudo do miocárdio a entidade nosológica mais freqüente dentre as doenças isquêmicas do coração. Os fatores de risco que predispõem as pessoas a essa doença estão relacionados a hábitos do estilo de vida e história familiar. Assim, esta investigação, de natureza descritiva, pretende identificar os fatores de risco relacionados ao meio ambiente, à biologia humana, estilo de vida, e sistema de saúde de pacientes internados em um hospital privado, até 48 horas após a ocorrência de infarto agudo do miocárdio, identificar o conhecimento quanto aos fatores de risco para o desenvolvimento de novos problemas de saúde e verificar se algumas variáveis, relacionadas aos fatores de risco de pacientes infartados em hospital público e privado, são semelhantes. O referencial teórico foi o Modelo de Campo de Saúde que compõe elementos relacionados ao meio ambiente, biologia humana, estilo de vida e sistema de saúde. Foram entrevistados 31 pacientes internados, em um hospital privado de uma cidade do interior do Estado de São Paulo, no período de janeiro a julho de 2003, após assinatura do termo de consentimento informado. Os resultados revelam que, quanto ao meio ambiente, a maioria dos pacientes era alfabetizada, 11 (35,5%) tinha o primeiro grau completo, 10 (32,2%) eram aposentados e donas-de-casa, 24 (77,4%) trabalhavam em torno de 8 a 10 horas por dia e tinham somente um emprego, e a renda familiar mensal, para 19 (61,3%), encontrava-se na faixa de 5 a 15 ou mais salários-mínimos, 22 (70,9%) eram casados e 15 (48,3%) tinham três ou mais filhos, 21 (67,7%) eram procedentes de Ribeirão Preto e região e todos residiam em zona urbana. Em relação à biologia humana, 19 (61,3%) eram do sexo masculino, aproximadamente metade 17 (54,8%) encontrava-se na faixa etária de 40 a 59 anos, 18 (58,1%) encontravam-se com sobrepeso ou obesidade classes I e II. Quanto aos antecedentes familiares, os dados mais expressivos apontam que 23 (74,2%) apresentavam hipertensão arterial sistêmica, 15 (48,3%) diabetes melittus, 17 (54,8%) infarto agudo do miocárdio e 6 (19,3%) acidente vascular cerebral. Das mulheres entrevistadas, 7 (22,6%) faziam uso algum tipo de terapia de reposição hormonal. No tocante ao estilo de vida relacionado aos hábitos alimentares, 29 (93,6%) utilizavam frituras nas refeições, 14 (45,2%) ingeriam doces e refrigerantes diariamente e 13 (41,9%) tomavam três xícaras ou mais de café ao dia, 18 (58,1%) faziam uso de bebidas alcoólicas, 10 (32,2%) eram fumantes, 9 (29,0%) ex-fumantes e 18 (58,1%) sedentários. Quanto ao estresse, 12 (38,7%) sentiam-se estressados no local de trabalho e 19 (61,3%) dormiam menos que oito horas por noite. Em relação ao sistema de saúde, 16 (51,6%) conheciam o diagnóstico, 12 (38,7%) apresentaram dúvidas acerca da doença, 21 (67,7%) utilizavam os serviços de saúde oferecidos pelo plano de saúde e 17 (54,8%) realizavam tratamento de hipertensão arterial sistêmica e diabetes melittus. Os dados revelam que os pacientes infartados estão expostos a hábitos autocriados que são passiveis de modificação havendo a necessidade de iniciar este processo educativo inclusive no período de internação hospitalar. / The cardiovascular diseases in Brazil, constitute nowadays death’s first cause and myocardial infarction is the most frequent nosological entity amonmg heart isquemical diseases. Among risk factors which predispose people committed by this disease are their life style’s and familiar history’s habits. This descriptive investigation intended to identify the risk factors related to the environment, human biology, life style and health systems of patients admitted in a private hospital, until 48 hours after the myocardial infarction; identify the knowledge’s blanket concerning to the risk factors related to new health problems’ development and verify if some variables are related to the risk factors which are similar to those of admitted patients in private and public hospitals. The theoretical referential used was the Health Model Field which constitutes the elements linked to the environment, human biology, life style an health system. We interviewed 31 internee patients in a private hospital in São Paulo’s interior, from January through July, 2003. Concerning to the environment 93,5% of the patients were literate; among them 11 (35,5%) had completed high school; related to their occupation 10 (32,2%) were retired and housewives; concerning to their working hours and job numbers, 24 (77,4%) work around 8 or 10 hours a day and have only one job; when referring to their familiar monthly income, 19 (61,3%) obtained from 5 to or more minimum salaries; 22 (70,9%) were married and 15 (48,3%) had three or more children; 21 (67,7%) were from Ribeirão Preto and its region and all of them lived in urban areas. When referring to the human biology, 19 (61,3%) were masculine and their ages varied between 40 and 59 years old; 18 (58,1%) were over weighted or fat, belonging to classes I and II; concerned to the familiar preceding, the most expressive data showed that 23 (74,2%) presented systemic arterial hypertension; 15 (48,3%) mellitus diabetes; 17 (54,8%) myocardial infarction and 6 (19,3%) cerebral vascular accident; 7 (22,6%) were feminine and were using hormones. Concerned to their life style, related to the feeding habits, 29 (93,6%) were accustomed to eat fried food; 14 (45,2%) used to eat sweeties and drink soft drinks daily; 13 (41,9%) used to drink 3 or more cups of coffee a day. When referring to the use of alcoholic drinks, 18 (58,1%) used to drink it; 10 (32,2%) were smokers and 9 (29,0%) were ex-smokers; 18 (58,1%) were sedentary. When referring to the stressing environment and sleeping patterns, 12 (38,7%) mention the work place and 19 (61,3%) sleep less than 8 hours a day. Concerning to the health system, 16 (51,6%) knew their diagnosis; 12 (38,7%) presented doubts about their diseases; 21 (67,7%) used the health services offered by their health insurance and 17 (54,8%) were under arterial hypertension and mellitus diabetes treatment. The data showed the patients who suffered by myocardial infarction are exposed to “selfcreated" habits, which may be modified and it is important to mention the necessity of raising educative programs including the patient’s permanence at the hospital.
246

Mapeamento do sítio de produção do microRNA-423-5P em modelo animal de remodelamento cardíaco após insulto isquêmico

Medeiros, Niara da Silva January 2018 (has links)
O objetivo desta tese é avaliar a expressão do miRNA-423-5p, em diferentes sítios, em modelo experimental de remodelamento cardíaco após insulto isquêmico em ratos. Os animais foram randomizados em grupos SHAM (cirurgia sem oclusão da artéria coronária descendente anterior esquerda) ou IAM (cirurgia com ligadura da artéria coronária descendente anterior esquerda) e acompanhados por 1, 7, 28 e 90 dias. Após o tempo de seguimento, os animais foram submetidos ao ecocardiograma e eutanasiados. Foi retirado sangue do plexo retroorbital, sangue venoso e arterial e coletado tecido do músculo gastrocnêmio e do ventrículo esquerdo separando as áreas remota (REM), infartada (INF) e peri-infartada (PERI). A partir da homogeneização dos tecidos, foi realizada a extração de miRNA e sua expressão quantificada pelo método de PCR em tempo real. Também foi mensurado os níveis plasmáticos do peptídeo natriurético cerebral (BNP). Os dados foram analisados pela teste de ANOVA de uma e duas vias e correlações através do programa estatístico SPSS 21.0. Quanto a caracterização do modelo utilizado, podemos verificar que a fração de ejeção do ventrículo esquerdo dos ratos IAM foram menores que os do grupo SHAM e os percentuais de área acinética foram iguais em todos os grupos IAM, como esperado. Também observamos que o miRNA-423-5p é expresso no coração, nos diferentes segmentos analisados, apresentando variação significativa nos tempos avaliados, correlacionado-se positivamente com o tamanho do infarto e negativamente com a fração de ejeção do ventrículo esquerdo. Diante deste cenário, nossos achados solidificam o conceito de que a expressão do miRNA-423-p se altera ao longo do tempo após insulto isquêmico e pode ter papel relevante no remodelamento cardíaco de origem isquêmica. / The objective of this project was to evaluate the expression of miRNA-423-5p in an experimental model of cardiac remodeling after ischemic injury in rats. Animals were randomized to SHAM group (surgery without occlusion of the left anterior descending coronary artery) or acute myocardial infaction (AMI) group (surgery with ligation of the left anterior descending coronary artery) and followed for 1, 7, 28 and 90 days. After the follow-up period, the animals were submitted to echocardiography and euthanized. Blood from the retroorbital plexus, venous and arterial blood was collected; and gastrocnemius and left ventricle tissue was collected, separating the remote (REM), infarcted (INF) and peri-infarcted (PERI) areas. From the homogenization of tissues, miRNA was extracted and its expression quantified by real-time PCR. Plasma levels of brain natriuretic peptide (BNP) were also measured by ELISA. Data were analyzed by one-way and two-way ANOVA and coefficient correlations were calculated using the statistical package SPSS 21.0. Regarding the experimental model, we could verify that the left ventricular ejection fraction of the AMI rats were reduced compared to the SHAM group and the percentages of akinetic area were the same in all AMI groups, as expected. We also observed that miRNA-423-5p is expressed in the heart in the different segments analyzed, showing significant variation in the different periodos that were evaluated, is positively correlated with infarct size and negatively with left ventricular ejection fraction. In this scenario, our findings solidify the concept that miRNA-423-p expression changes over time after an ischemic insult and may play a relevant role in the cardiac remodeling of ischemic origin.
247

Ischaemic and pharmacological preconditioning of the uraemic heart

Byrne, Conor James January 2011 (has links)
The incidence and mortality from cardiovascular disease (CVD) in patients with chronic kidney disease (CKD) far exceeds that seen in the general population. Whilst a number of risk factors and associations have been identified in patients with CKD that may contribute to the increased risk of CVD, our understanding of the underlying pathophysiology remains poor. It has previously been reported that uraemic animals sustain larger myocardial infarcts and that this ‘reduced ischaemia tolerance’ may in part explain the excess mortality from CVD seen in CKD patients. The aim of this work was to establish an in vivo model of uraemic myocardial infarction in order to further explore the pathophysiology of uraemic CVD with particular focus on ameliorating myocardial ischaemia-reperfusion injury using ischaemic and pharmacological preconditioning. An increase in myocardial infarct size was demonstrated in the sub-total nephrectomy model of chronic uraemia, confirming previous reports in the literature. However, infarct size was not found to be increased in adenine diet induced renal failure. In addition, it was demonstrated for the first time, that the techniques of ischaemic preconditioning (IPC) and remote ischaemic preconditioning (RIPC) are both efficacious and not attenuated by chronic uraemia induced by sub-total nephrectomy or adenine diet (IPC only). Investigations were undertaken using an agent (a HIF stabiliser, FG4497) to induce pharmacological preconditioning in both animals with renal insufficiency and those without. These studies demonstrate that stabilisation of hypoxia inducible factor (HIF) may be a promising strategy to induce pharmacological preconditioning. It is hoped that this work may lay the foundations for future investigations to determine why sub-totally nephrectomised rats have larger infarcts whilst those with adenine induced renal failure, with a substantially greater degree of renal dysfunction, do not. Moreover, it is hoped that; by demonstrating that uraemia 3 does not prevent or attenuate the myocardial protection afforded by ischaemic preconditioning, the recruitment of patients with CKD will be encouraged to clinical trials of both ischaemic preconditioning and other therapies to limit myocardial infarction.
248

The trajectory of functional status before and after vascular events

Dhamoon, Mandip Singh January 2016 (has links)
Background: Previous studies that have examined functional status in relation to vascular events have focused on the short term after events and have measured functional status a limited number of times. The trajectories of functional status before and after vascular events are not well characterized, and the factors influencing these trajectories are not well known. Methods: A comprehensive, structured, narrative review was performed on the topic of trajectories of disability and cognition surrounding vascular events. Then using 2 large population-based epidemiologic cohorts, the Northern Manhattan Study (NOMAS) and the Cardiovascular Health Study (CHS), trajectories of functional status were examined. In Analysis A, in NOMAS, the effect of inflammatory biomarkers (interleukin-6 [IL6], tumor necrosis factor receptor-1 [TNFR1], C-reactive protein [CRP], and lipoprotein-associated phospholipase-A2 [LpPLA2]) on the intercept and slope of functional status was determined over a median of 13 years, measured with yearly assessments by the Barthel index. In Analysis B, in NOMAS, a similar modeling strategy was used to examine whether subclinical ischemic disease on brain MRIs, measured by subclinical brain infarct (SBI) and white matter hyperintensity volume (WMHV), was associated with functional trajectories. In Analysis C, in CHS, participants had yearly assessments of disability with a combined activities of daily living (ADL) and instrumental ADL scale. The slope of change in disability was compared before and after vascular events (stroke and myocardial infarction [MI]). Results: In Analysis A, CRP (-0.41 BI points per 1 SD increase, 95% CI -0.82 to 0.002) and LpPLA2 (-0.40, 95% CI -0.75 to -0.04) were associated with baseline BI but not change over time. TNFR1 was associated with baseline BI (-0.93, 95% CI -1.59 to -0.26) and change over time (-0.36 BI points per year, 95% CI -0.69 to -0.03). In Analysis B, functional change was -0.85 BI points per year (95%CI -1.01 to -0.69); among those with SBI there were -0.88 additional points annually (-1.44 to -0.32). In WMHV models, annual functional change was -1.04 points (-1.2 to -0.88), with -0.74 additional points annually per SD WMHV increase (-0.99 to -0.49). In Analysis C, stroke (0.88, 95% CI 0.57-1.20, p<0.0001) was associated with a greater acute increase in disability than MI (0.20, 0.06-0.35, p=0.006). The annual increase in disability before stroke (0.06 points per year, 0.002-0.12, p=0.04) more than tripled after stroke (0.15 additional points per year, 0.004-0.30, p=0.04). The annual increase in disability before MI (0.04 points per year, 0.004-0.08, p=0.03) did not change significantly after MI (0.02 additional points per year, -0.07-0.11, p=0.7). Conclusions: In these large population-based studies with repeated measures of functional status and disability over long-term follow-up, several trajectories were found. In Analysis A, TNFR1 predicted worse overall functional status as well as accelerated decline over time. In Analysis B, both SBI and WMHV were associated with accelerated decline. In Analysis C, there was a steeper decline in function after stroke but not MI. These findings help to elucidate the course and potential etiologies of long-term functional decline related to vascular events, and they suggest directions for future research in this area.
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Community reintegration among Latino stroke survivors: An ecological framework

Aguirre, Alejandra Nicole January 2018 (has links)
Purpose: In the United States, stroke is the leading cause of disability. The majority of survivors sustain permanent physical and/or cognitive impairments. Stroke survivors with impairments experience depression, loss of functional independence, and poor quality of life (QOL). Stroke disparities exist among different racial and ethnic groups of the US population. Latinos experience a first time stroke at a younger age compared to non-Latino Whites. As a result, Latinos live with impairments for a greater number of years. The vast majority of stroke survivors return to live in their communities. Reintegrating into home and social activities is key to survivors’ perceived QOL. This dissertation project sought to understand from an ecological framework the post-stroke community reintegration experiences of Latino older adults in an urban New York City neighborhood. The study also sought to examine the viewpoints of health and social service providers, whose opinions, actions, and programs can support stroke survivors’ reintegration into community. Methods: Qualitative in-depth interviews were conducted with 30 Latino stroke survivors 50 years of age and older who had experienced a disabling stroke within 36 months. In addition, 20 health and social service providers based in a large medical center, and multiple senior centers in the northern Manhattan section of New York City were interviewed. The stroke survivor data was analyzed using a phenomenological approach. A thematic analysis approach was used to analyze the data from the health and social service informants. Data analysis identified physical, psychological, social, and environmental factors pertinent to stroke survivors’ community integration experiences. These identified factors were categorized into macro-, exo-, meso-, and micro-levels to capture the psycho, social, and environmental ecology in which community reintegration takes place for Latino stroke survivors. Results: Qualitative accounts of survivors revealed several microsystem factors, including a struggle to maintain a positive self-concept and to engage in activities associated with valued identities and roles, while simultaneously suffering chronic pain, fatigue, and functional limitations. Changes in their affect lead survivors to socially isolate themselves. In addition, they relied more on women than men for social support, a salient mesosystem factor. Survivors encountered significant exosystem level barriers in the environment that limited their ability to travel and access activities. For some, these barriers inadvertently left survivors homebound. Survivors also encountered a societal culture, a macrosystem factor, which stigmatized them due to their impairments. Interviews with health and social service professionals revealed various factors that influenced community reintegration of people with stroke. At the macrosystem level, funding for programs and healthcare financing dictated services and eligibility criteria. In the exosystem, a segmented medical model of care postponed the conversation on community integration. Professional practices, organizational level constraints and culture were mesosystem level factors that influenced community reintegration. The confluence of these factors created an ecological system that influenced stroke survivors’ opportunities to socially engage in their home and community life. Conclusion: An ecological approach provides a useful framework to understand the complexity and potential interplay of factors that contribute to community integration post-stroke for Latino older adults in an urban area.
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Can promotion of neutrophil apoptosis enhance repair in the infarcted myocardium and resolution of sterile peritonitis?

Zhao, Xiaofeng January 2016 (has links)
Efferocytosis, the clearance of apoptotic cells including apoptotic neutrophils by macrophage phagocytosis, is a key cellular mechanism for resolution of inflammation and tissue repair. Cyclin-dependent kinases (CDKs) 7 and 9 phosphorylate RNA polymerase II that is vital for neutrophil transcriptional capacity. CDK inhibitors such as R-roscovitine, and the more selective inhibitor AT7519, induce neutrophil apoptosis and promote resolution of several mouse models of inflammation including acute lung inflammation. The hypothesis investigated here was that AT7519 would promote neutrophil apoptosis (i) in the infarcted heart, leading to macrophage polarisation, angiogenesis, reduced infarct expansion and retention of cardiac function and (ii) in the peritoneum, enhancing resolution of sterile peritonitis. AT7519 (1μM) induced apoptosis of mouse unstimulated-bone marrow derived neutrophils and thioglycollate-stimulated neutrophils in vitro in a time- and caspase-dependent manner, but did not alter activation assessed by calcium flux in response to the synthetic formyl peptide (fMLF) or platelet-activating factor (PAF). Only high concentrations of AT7519 (10 μM) induced monocyte/macrophage apoptosis and this was likely due to saturated phagocytosis of apoptotic neutrophils induced by high concentration of AT7519. Myocardial infarction (MI) was induced by coronary artery ligation in adult male mice and infarct volume was assessed 7 or 21 days later by in vitro optical projection tomography (OPT). The novel use of OPT for this purpose was validated by demonstrating correlation with infarct volume obtained by late-gadolinium enhanced magnetic resonance imaging in vivo and with infarct area assessed by histological staining (Masson’s Trichrome) in tissue sections. AT7519 (30 mg/kg i.p.) increased the number of apoptotic neutrophils (cleaved caspase-3 and Ly6G +ve) in the heart when administered after MI, but this was not associated with any subsequent alteration in macrophage polarisation, vessel density, infarct expansion or structural and functional remodelling of the left ventricle. In contrast, induction of neutrophil apoptosis by AT7519 (30mg/kg i.p.) successfully promoted macrophage polarisation and the resolution of inflammation associated with peritonitis elicited by either 10% thioglycollate or by 1mg zymosan. AT7519 treatment also reduced the number of CD19+ B cells, Foxp3+CD4+ T cells and eosinophils in peritoneal lavage, and prolonged the phase of monocyte recruitment in zymosan-induced peritonitis. In conclusion, AT7519 successfully induced mouse neutrophil apoptosis in vitro, as well as in vivo in experimental MI and peritonitis. Subsequent promotion of inflammation resolution in peritonitis was not matched by improved outcome following MI. Unexpected effects of CDK inhibition on monocytes, T cells and eosinophils that are necessary for myocardial infarct repair may have compromised any beneficial effects resulting from promotion of in situ neutrophil apoptosis. CDK inhibition may therefore have therapeutic potential for the treatment of peritonitis, but not for prevention of infarct expansion and detrimental ventricular remodelling after MI.

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