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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.
11

Cellular responses to respiratory chain dysfunction /

Hansson, Anna, January 2005 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 3 uppsatser.
12

Hypertension and diabetic cardiomyopathy

Rodrigues, Brian Baltzar January 1985 (has links)
The isolated perfused working heart was used to study hypertensive- diabetes induced alterations in cardiac function at 6 and 12 weeks after the induction of diabetes. There was no difference in cardiac function between normotensive Wistar and spontaneously hypertensive (SHR) diabetic rats at 6 weeks after diabetes induction. Wistar-Kyoto (WKY) rats were also included as normotensive controls in our 12-week study. Successful induction of diabetes was confirmed by the presence of hyperglycemia, hypoinsulinemia, glycosuria and increased haemoglobin glycosylation in all three diabetic groups. However, quantitation of various parameters of heart function revealed highly significant differences between SHR diabetic animals and all other groups, associated with an increased mortality. Serum lipids were elevated in SHR and Wistar and unaffected in WKY diabetic rats. Furthermore, thyroid hormone levels were not depressed in WKY diabetic rats and could explain the lack of cardiac dysfunction in these animals. The data provide further evidence that the combination of hypertension and diabetes mellitus produces greater myocardial dysfunction than is seen with either disease alone and is associated with a significant mortality. The effects of hydralazine on blood lipids, systolic pressure and cardiac performance were assessed in male Wistar rats, 6 weeks after they were made diabetic with streptozotocin (STZ). When hydralazine was administered for a 6-week period to the diabetic rats, their blood lipids were not significantly different from that of non-diabetic rats despite a low serum insulin. In contrast, blood lipids were elevated in the diabetic rats that were not treated with hydralazine; these animals also had low insulin levels. Cardiac performance was depressed in the untreated diabetic animals, but the cardiac performance of the hydralazine-treated diabetic animals showed a definite improvement which could be partly explained by their normal thyroid status in contrast to the untreated diabetic animals which were slightly hypothyroid. Blood pressure was elevated only in the untreated diabetic animals. Thus hydralazine controlled the high serum lipids and blood pressure and improved cardiac performance in STZ diabetic rats. To examine the influence of sex differences in the STZ model of diabetes, we studied left ventricular function in hearts from 6 week male and female rats. Significantly lower values for +dP/dt occurred in male diabetic rats compared with their own controls or female diabetics at most left atrial filling pressures. Decreases in this value for female diabetic rats compared to their own controls occurred only at high left atrial pressures. It appears that diabetes mellitus produces greater myocardial dysfunction in male diabetic rats. / Pharmaceutical Sciences, Faculty of / Graduate
13

Polimorfismo de inserção/deleção do gene da enzima de conversão da angiotensina I em portadores de insuficiência cardíaca / Insertion/deletion polymorphism of the angiotensin I-converting enzyme gene in patients with heart failure

Cuoco, Marco Antonio Romeo 03 November 1998 (has links)
O polimorfismo de inserção/deleção (I/D) do gene da enzima de conversão da angiotensina I foi estudado em coorte de sobreviventes de 333 portadores de insuficiência cardíaca, de idades entre 13 e 68 (43,3 ± 10,5) anos, 262 (78,7%) dos quais eram homens e 71 (21,3%) mulheres. O grupo controle foi constituído de 807 doadores voluntários de sangue com idades entre 18 e 60 (31,5 ± 9,3) anos, 557 (69%) dos quais eram homens e 250 (31%) mulheres. A insuficiência cardíaca foi atribuída à cardiomiopatia dilatada idiopática em 125 (37,6%) pacientes. Nos demais pacientes as etiologias foram: a cardiomiopatia insquêmica em 63 (18,9%), a cadriomiopatia da doença de Chagas em 58 (17,4%), a cardiomiopatia hipertensiva em 41 (12,3%), a cardiomiopatia alcoólica 24 (7,2%), a cardiomiopatia valvar em 11 (3,3%) e a cardiomiopatia periparto em 11 (3,3%). A determinação dos genótipos associados ao polimorfismo I/D foi realizada pela reação em cadeia da polimerase. Foram estudadas a distribuição dos genótipos entre os indivíduos do grupo controle e os pacientes e as prováveis associações do polimorfismo I/D com diferentes variáveis clínicas e com a evolução. Essas análises foram realizadas de acordo com o padrão de herança genética atribuído ao alelo D (co-dominante, recessivo ou dominante). Na análise estatística foram utilizados o teste do qui-quadrado, o teste t-Student, a análise de variância (ANOVA), o método de Kaplan-Meier, o teste log-rank e a regressão de Cox. A freqüência do genótipo DD foi menor no grupo de pacientes, considerando-se o caráter recessivo atribuído ao alelo D (p=0,034). Os portadores do genótipo DD apresentaram maior média de valores do diâmetro sistólico do ventrículo esquerdo determinado pelo ecocardiograma, quando foi atribuído caráter recessivo ao alelo D (p=0,031). O intervalo decorrido do nascimento até o aparecimento dos sintomas foi menor nos portadores do genótipo DD com cardiomiopatia alcoólica, ao ser atribuído caráter recessivo ao alelo D (p=0,033). O intervalo entre o nascimento e o aparecimento dos sintomas foi menor nos portadores do genótipo DD com cardiomiopatia hipertensiva, quando foi atribuído caráter co-dominante (p=0,048) ou recessivo (p=0,024) ao alelo D. Os portadores do genótipo DD apresentaram maior mortalidade após os 50 anos, ao ser atribuído caráter co-dominante (p=0,007) ou recessivo (p=0,002) ao alelo D. As variáveis independentes relacionadas com a maior mortalidade após os 50 anos de idade, ao ser atribuído caráter recessivo ao alelo D, foram: a idade (p<0,001), o genótipo DD (p=0,003), o diabetes melito (p=0,003) e a doença de Chagas (p=0,005). Atribuindo-se caráter co-dominante ao alelo D, as variáveis independentes relacionadas com maior mortalidade foram: a idade (p<0,001), a doença de Chagas (p=0,004), o diabetes melito (p=0,005) e o genótipo DD (p=0,015). Os resultados obtidos permitem sugerir que o genótipo DD está associado com maior morbidade e mortalidade em determinados grupos de pacientes com insuficiência cardíaca. / Insertion/deletion (I/D) polymorphism of the angiotensin I- converting enzyme gene was studied in a cohort of survivors of 333 patients with heart failure of different etiologies and in a control group of 807 volunteer blood donors. The age of the patients ranged from 13 to 68 (43,3 ± 10,5) years, 262 (78.7%) were men and 71 (21.3%) women. The age of the control group ranged from 18 to 60 (31,5 ± 9,3) years, 557 (69%) were men and 250 (31%) women. Idiopathic dilated cardiomyopathy was diagnosed in 125 (37.6%), ischemic cardiomyopathy in 63 (18.9%), Chagas\' disease cardiomyopathy in 58 (17.4%), hypertensive cardiomyopathy in 41 (12.3%), alcoholic cardiomyopathy in 24 (7.2%), valvular cardiomyopathy in 11 (3.3%) and peripartum cadiomyopathy in 11 (3.3%). The genotypes associated with the I/D polymorphism were determined by polymerase chain reaction. The distribution of the genotypes was determined in the control and patient groups as well the possible associations of the I/D polymorphism with clinical variables and the evolution. The chi-square test, the t-Student test, the analysis of variance (ANOVA), the Kaplan-Meire method, the log-rank test and Cox regression were used in the statistical analysis. The DD genotype was less frequent in patients, assuming a recessive effect of the D allele (p=0,0034). The left ventricular en-systolic diameter by echocardiography was higher in patients with the DD genotype, .... And the DD genotype, assuming a recessive effect of the D allele (p=0,033). The time elapsed until the onset of symptoms was shorter in patients with hypertensive cardiomyopathy and the DD genotype, assuming a codominant (p=0,048) or recessive (p=0.024) effect of the D allele. Patients older than 50 years with the DD genotype showed increased mortality, assuming a codominant (p=0,007) or recessive (p=0,002) effect of the D allele. The independent variables associated with increased mortality in patients older than 50 years were: age (p<0,001), the DD genotype (p=0,003), diabetes mellitus (p=0,003) and Chagas\' disease (p=0,005), assuming a recessive effect of the D allele. Assuming a codominant effect of the D allele, the independent variables associated with increased mortality in patients older than 50 years were: age (p<0,001), Chagas\' disease (p=0,004), diabetes mellitus (p=0,005) and the Dd genotype (p=0,015). These results suggest that the DD genotype may be associated with higher morbidity and mortality in some groups of patients with heart failure.
14

Differential gene expression during neonatal myocardial development revealed by suppression subtractive hybridization & expressed sequence tag sequencing. / CUHK electronic theses & dissertations collection

January 2000 (has links)
Stephen Siu-chung Chim. / "June 2000." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. 152-166). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
15

Impacto da fibrilação atrial no prognóstico da insuficiência cardíaca crônica sistólica secundária à cardiomiopatia da doença de chagas

Ardito, Sabrina Queiroz 06 April 2018 (has links)
Submitted by Suzana Dias (suzana.dias@famerp.br) on 2018-11-09T16:20:01Z No. of bitstreams: 1 SabrinaQueirozArdito_tese.pdf: 553115 bytes, checksum: 3a2e5134532370664d754e2648b56cf0 (MD5) / Made available in DSpace on 2018-11-09T16:20:01Z (GMT). No. of bitstreams: 1 SabrinaQueirozArdito_tese.pdf: 553115 bytes, checksum: 3a2e5134532370664d754e2648b56cf0 (MD5) Previous issue date: 2018-04-06 / Chagas disease is caused by the parasite Trypanosoma cruzi. It is a chronic, systemic disease, which affects about 6 million people in Latin America and 30-40% has cardiomyopathy secondary to this disease. In the vast majority of cases, the main cause of death is related to the final stages of chronic heart failure. Chagas disease has become a growing health problem in non-endemic areas due to migration. Objective: To evaluate the impact of atrial fibrillation on the prognosis of chronic systolic heart failure secondary to Chagas cardiomyopathy. Material and Methods: About 234 patients routinely followed at the Cardiomyopathy Outpatient Service of Hospital de Base of São José do Rio Preto Medical School in the SUS, from January 2000, to December 2010, with the diagnosis of chronic heart failure secondary to Chagas cardiomyopathy were included in the study. A Cox proportional hazard model was used to detect independent predictors of all-cause mortality in the studied population. A survival curve was built for patients with and without atrial fibrillation. In all the circumstances, p value <0.05 was considered statistically significant. Results: Atrial fibrillation was observed in 63 patients (26.9%). In a cox proportional hazard model analysis, beta-blocker therapy ( Hazard Ratio=0.381; 95% Confidence Interval 0.257 to 0.563, p value <0.001), use of metoprolol succinate (Hazard Ratio=0.382; 95% Confidence Interval 0.170 to 0.855, p value=0.019), use of Losartan (Hazard Ratio=0.611; 95% Confidence Interval 0.380 to 0.981, p value =0.041), and left systolic ventricular diameter (Hazard Ratio=1.042; 95% Confidence Interval 1.021 to 1.063, p value <0.001) were determined independent predictors of all-cause mortality. Survival probability at 12, 24, 36, 48 and 60 months was 80%, 65%, 56%, 44% and 37%, respectively, in patients without atrial fibrillation, and 76%, 58%, 48%, 41% and 32% in patients with atrial fibrillation, (p=0.393). Conclusion: Atrial fibrillation has no prognostic significance in patients with chronic systolic heart failure secondary to Chagas Cardiomyopathy. / A doença de Chagas é causada pelo parasita Trypanosoma cruzi. É uma doença crônica, sistêmica, que afeta cerca de seis milhões de pessoas na América Latina, e 30-40% têm cardiomiopatia secundária a essa patologia. Para a grande maioria, a principal causa de morte está relacionada a estágios finais de insuficiência cardíaca crônica. A Doença de Chagas tem se tornado um problema de saúde crescente em áreas não endêmicas devido ao deslocamento e crescimento populacional. Objetivo: Avaliar o impacto da fibrilação atrial no prognóstico da insuficiência cardíaca crônica sistólica secundária à cardiomiopatia da Doença de Chagas. Casuística e Método: Foram incluídos no estudo 234 pacientes seguidos no Ambulatório de Cardiomiopatia do Hospital de Base da Faculdade de Medicina de São José do Rio Preto, no Sistema Único de Saúde, no período de janeiro de 2000 a dezembro de 2010, que apresentavam o diagnóstico de insuficiência cardíaca crônica sistólica secundária à cardiomiopatia da Doença de Chagas. O modelo de risco proporcional de Cox foi utilizado para detectar variável de predição independente de mortalidade geral na população como um todo, bem como para revelar variáveis de predição independentes de mortalidade geral em pacientes com fibrilação atrial. Foi construída curva de sobrevida dos pacientes pelo método de Kaplan-Meier de acordo com as variáveis de predição identificadas. Da mesma forma, construiu-se curva de sobrevida para pacientes com e sem fibrilação atrial. Em todas as circunstâncias, considerou-se valor de p <0,05 como estatisticamente significante. Resultados: A fibrilação atrial foi observada em 63 pacientes (26,9%). Terapia com betabloqueador (Razão de Risco=0,381; Intervalo de Confiança 95% de 0,257 a 0,563, p<0,001), uso de succinato de metoprolol ( Razão de Risco=0,382; Intervalo de Confiança 95% de 0,170 a 0,855, p=0,019), uso de Losartan (Razão de Risco=0,611; Intervalo de Confiança 95% de 0,380 a 0,981, p=0,041), e o diâmetro sistólico do ventrículo esquerdo (Razão de Risco=1,042; Intervalo de Confiança 95% de 1,021 a 1,063, p<0,001) as variáveis de predição independentes de mortalidade geral. A probabilidade de sobrevida em 12, 24, 36, 48 e 60 meses foi de 80%, 65%, 56%, 44% e 37%, respectivamente em pacientes sem fibrilação atrial, e 76%, 58%, 48%, 41% e 32% em pacientes com fibrilação atrial, (p=0,393). Conclusão: A fibrilação atrial não tem significado prognóstico em pacientes com insuficiência cardíaca crônica sistólica secundária à cardiomiopatia da Doença de Chagas.
16

Methods for comprehensive transcriptome analysis using next-generation sequencing and application in hypertrophic cardiomyopathy

Christodoulou, Danos C. 08 October 2013 (has links)
Characterization of the RNA transcriptome by next-generation sequencing can produce an unprecedented yield of information that provides novel biologic insights. I describe four approaches for sequencing different aspects of the transcriptome and provide computational tools to analyze the resulting data. Methods that query the dynamic range of gene expression, low expressing transcripts, micro RNA levels, and start-site usage of transcripts are described.
17

Myocardial effects of type 2 diabetes, co-morbidities, and changing loading conditions : a clinical study by Tissue Velocity Echocardiography /

Govind, Satish C. January 2007 (has links)
Diss. (sammanfattning) Stockholm : Kungliga Tekniska högskolan, 2007. / Härtill 5 uppsatser.
18

Cardiovascular complications of ischemic renal disease : the effect of renal dysfunction on cardiac disease and the central role of cardiotonic steroids in the pathogenesis of uremic cardiomyopathy

Kennedy, David J. January 2005 (has links)
Thesis (Ph.D.)--Medical University of Ohio, 2005. / "In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Medical Sciences." Major advisor: Joseph I. Shapiro. Includes abstract. Document formatted into pages: v, 265 p. Title from title page of PDF document. Bibliography: pages 52-59,94-100,129-134,171-176,200-263.
19

Desenvolvimento de modelo experimental de insuficiencia cardiaca em coelhos / Experimental model of heart failure in rabbits

Vilarinho, Karlos Alexandre de Sousa, 1976- 30 July 2008 (has links)
Orientador: Orlando Petrucci Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-11T17:47:29Z (GMT). No. of bitstreams: 1 Vilarinho_KarlosAlexandredeSousa_M.pdf: 5350475 bytes, checksum: 25a2a28e1fa1a21cc4b04d4aa5532e11 (MD5) Previous issue date: 2008 / Resumo: Introdução: É importante o desenvolvimento de modelos reprodutíveis de insuficiência cardíaca, para melhor entendimento da fisiopatopatologia, desenvolvimento e validação de métodos terapêuticos nessa síndrome. Poucos experimentos comparam os modelos entre si, dentro da mesma espécie animal. Objetivo: Desenvolver modelo experimental de insuficiência cardíaca em coelhos com dois tipos de intervenção. Material e método: Foram induzidas sobrecarga volêmica por insuficiência aórtica (GI-18 animais) e sobrecarga pressórica por constrição da aorta (GE-16 animais), e comparados com grupo controle (GC-11 animais). Os animais foram observados por oito semanas e submetidos a estudo hemodinâmico e histopatológico. Foi considerado estatisticamente significante p<0.05 Resultados: Nenhum animal apresentou sinais clínicos de insuficiência cardíaca. Houve aumento da relação peso ventrículo esquerdo (VE)/coelho no GI e GE; aumento dos volumes diastólico e sistólico final, volume ejetado e débito cardíaco no GI; aumento da espessura da parede septal e lateral do VE no GE; não houve alterações na fração de ejeção, dP/dT máxima e mínima, tempo de relaxamento isovolumétrico, relação pressão-volume diastólico final e trabalho sistólico entre os grupos. Houve diminuição da elastância máxima e do trabalho sistólico pré-recrutável nos grupo GE e GI. Houve aumento da área pressão-volume total (PVA) no GI. Houve aumento da fibrose no GE. Conclusão: Padronizamos dois modelos de IC em fase compensada em coelhos. As lesões histológicas demonstram que a fibrose é mais proeminente no GE, no período estudado, e os índices de contratilidade demonstram piora, sem sinais clínicos de IC, no GI e GE. / Abstract: Introduction: The development of heart failure experimental models is important to better understanding of physiopathology and validation of new therapeutic strategies. Few previous reports compared the models within the same animal species. Objective: Development and standardization of heart failure experimental model in rabbits with two interventions. Material and method: Volume overload was induced by aortic lesion (GI-18 animals) and pressure overload by aortic constriction (GE-16 animals) and compared with control (GC-11 animals). Eight weeks after the intervention we performed hemodynamic and histopathology studies in all animals. Results: Animals did not develop clinical heart failure. The left ventricle/rabbit relation was increased in GI and GE; final diastolic and systolic volumes, stroke volume and cardiac output were increased in GI; septal and lateral left ventricle walls were increased in GE; ejection fraction, maximal and minimal dP/dT, isovolumic relaxation time, end diastolic pressure-volume relation and systolic work were equal between the groups. Maximal elastance and pre-recruitable systolic work were lower in GE and GI. Pressure-volume area (PVA) was increased in GI. Conclusion: Two models of compensated heart failure were developed in rabbits. The myocardial fibrosis was more important in GE and contractility indices were worse, without clinical heart failure, in GE and GI / Mestrado / Pesquisa Experimental / Mestre em Cirurgia
20

Altered drug responses in diabetic and hypertensive-diabetic cardiomyopathy

Yu, Zhen January 1990 (has links)
Diabetes mellitus has been associated with both clinical and experimental cardiac dysfunction. Diabetic cardiomyopathy which is characterized by depressed cardiac contractility is accompanied by a variety of biochemical changes in Ca⁺⁺ metabolism. This cardiomyopathy may occur in the presence of normal coronary arteries and normal blood pressure. However, some studies have shown that hypertension is more prevalent among diabetics and can aggravate the cardiovascular abnormalities associated with diabetes. To understand the mechanisms of diabetic cardiomyopathy and consequences of combined hypertension and diabetes, experiments were designed to measure cardiac tissue responses to various inotropic agents in experimental diabetes. Six weeks following streptozotocin (STZ) administration, Wistar, spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats exhibited the 'classical signs' of diabetes which included: hyperglycemia, hypoinsulinemia, hyperlipidemia (except in WKY), and hypothyroidism. Decreased basal atrial rate and increased basal developed force (BDF) suggest a depressed SA node function and an alteration of Ca⁺⁺ utilization by diabetic ventricles. Decreased post quiescent potentiation (PQP) values (except in WKY) in ventricular tissues suggest a diminished amount of releasable Ca⁺⁺ from sarcoplasmic reticulum (SR). Decreased post stimulation potentiation (PSP) values in SHR papillary muscles (PM) are probably suggestive of a depressed sarcolemmal Na⁺-Ca⁺⁺ exchange function in this tissue. Diabetic rats show subsensitivity to β-adrenergic stimulation in ventricular tissues, supersensitivity and hyperresponsiveness to Ca⁺⁺ and α-adrenergic stimulation (except in WKY) in ventricular tissues and left atria (LA) and supersensitivity to BAY K 8644 in SHR LA and hyperresponsiveness to verapamil in ventricular strips. These alterations may be attributed to a change in receptor number and/or a post receptor alteration. Ryanodine decreased the PQP of Wistar and SHR PM and SHR LA in both controls and diabetics. It especially abolished PQP in SHR diabetic tissues, but had no effect on WKY tissues, which may suggest a difference in the SR function in these tissues. SR with impaired Ca⁺⁺ uptake may contribute to these phenomena in diabetic rats. Ryanodine also diminished (PQP + BDF) of SHR LA and (PQP/BDF) of Wistar and SHR PM, ˙but had no effects on control and other diabetic tissues. It appears that ryanodine has some influence on the Na⁺-Ca⁺⁺ exchange generated by sarcolemma (SL) of certain diabetic tissues. Further experiments are required to clarify this. SHR diabetic rats had greater changes in most of the measurements such as hyperlipidemia, depressed PQP and PSP values, and altered drug responses. This model exhibited very high mortality as compared to Wistar and WKY diabetic rats. As has been shown previously, the combination of hypertension and diabetes exerts a synergistic effect on the cardiac dysfunction in this model, and that altered lipid metabolism, SL and SR function are all involved in the development of cardiomyopathy. WKY diabetic rats, on the other hand, exhibited no significant changes in blood lipids, or in response to phenylephrine or to Ca⁺⁺ (LA) stimulation. Lack of change in these factors may explain the relatively normal cardiac function of this model as measured previously. / Pharmaceutical Sciences, Faculty of / Graduate

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