lschemic disease in form of ischemic heart disease (IHD), ischemic stroke and peripheral arterial disease (PAD) due to atherosclerosis represents a massive clinical and economic burden to healthcare and is currently the number one cause of death in the world. Treatment modalities for peripheral arterial disease include bypass surgery involving autologous vein or synthetic materials such as ePTFE. Long term patency of small diameter vascular grafts used for infra-inguinal reconstructions, however, is below 50 % 5 years after implantation. Therefore, novel vascular graft concepts and materials are needed. The concept of transmural in vivo endothelialisation of vascular grafts holds great promise for increasing long term patency. To achieve complete luminal endothelial cell coverage and optimal integration of the porous synthetic graft material into the host tissue, transmural ingrowth of tissue and vasa vasorum might have to be facilitated. Since VEGF1ss and PDGF-BB are growth factors known to stimulate and consolidate angiogenesis, this PhD thesis hypothesized, that neovascularisation of porous polyurethane (PU) can be increased by delivery of vascular endothelial growth factor (VEGF1ss) and platelet derived growth factor (PDGF-BB). To prove this hypothesis, subcutaneous implantation of PU discs was established as a valid, reproducible, relatively simple and quantifiable neovascularisation model. Three different ways of growth factor delivery were investigated. The gene encoding for human VEGF15s was cloned into the genome of adeno associated viruses (AAV), which served as a vector for gene transduction of autologous wound healing cells in vivo using the "Gene Activated Matrix" approach. Genetically modified matrix embedded AAV-VEGF155 was loaded into porous PU and transduced autologous ingrowing wound cells. In contrast to the excellent transduction efficiency in myocytes, AA V showed a poor tropism for wound healing cells. The second approach to increase neovascularisation into porous PU was the surface modification of PU by covalent attachment of nitrous acid degraded heparin. Neovascularisation into the biomaterial was increased by 77 % after 10 days of subcutaneous implantation. Since certain angiogenic growth factors show a high affinity for heparin, additional loading of heparin surface modified PU with VEGF165 increased neovascularisation even further up to 115 % at 10 days compared to control. Dual growth factor delivery of VEGF 165 and PDGF-BB not only initiated increased vascularisation of porous PU, but also created a stable vascular network 2 months after implantation. In contrast, PU loaded with VEGF165 alone showed regression of total vascular area of 61 % compared to vascular area at 10 days. Thirdly, to study the effects of controlled, prolonged growth factor delivery, a "Neovascularisation Construct" was developed which was implanted subcutaneously in rats. The construct consisted of an osmotic mini pump and a tube of porous PU lined with ePTFE, into which a defined amount of VEGF16s was pumped for 10 days. After implantation, granulation tissue was growing into the pores of the PU and neovascular area was increased up to 265 % compared to PBS control. Furthermore, using different growth factor concentration, a dose dependency was shown. In addition, this thesis investigated the functional perfusion of the micro vascular network growing into PU by four different vascular quantification techniques. lntravital perfusion with biotinylated lycopersicon esculentum followed by microscopical analysis, vascular corrosion casting quantified by scanning electron microscopy as well as the novel micro-CT analysis of silicone rubber perfused vessels were compared to conventional immunhistochemical analysis of endothelial cells by CD31. Interestingly, PBS perfused "Neovascularisation Constructs" showed a relatively poor perfusion; therefore CD31 immunohistochemistry "overestimated" functional neovascularisation 3 fold. All perfusion techniques indicated a strong effect of VEGF 165 delivery on vessel perfusion (10 to 20 fold increases of vascular area and volume compared to PBS control). Micro-CT scanning was shown to be an excellent tool to study micro vascular networks in a three-dimensional fashion across the whole length of the sample in a limited amount of time and to provide reliable and reproducible data on vessel density, vascular volume, and connectivity. Since resolution is still limited today to about 10 μm using a commercially available bench top scanner, this new technology still needs to be complemented by immunohistochemistry and perfusion studies such as lectin perfusion and corrosion casting. In summary, the induction of neovascularisation was achieved by heparin surface modification alone, which was even increased through additional delivery of growth factors into the biomaterial PU. The development of a stable micro vascular network at 2 months was achieved and the functionality was shown using four different, independent techniques including the novel micro-CT scanning of neovascularisation into biomaterials. Towards the development of an in vivo, spontaneously and transmurally endothelialising vascular graft with superior long-term patency further investigations are necessary. As an initial step, increased spontaneous neovascularisation of the possible graft material polyurethane was achieved. Future steps are clearly indicated to study the translation of increased neovascularisation of the biomaterial polyurethane towards increased endothelialisation in a vascular graft model.

No description available.

Diversos autores têm apontado o diabetes como fator de risco independente para a doença isquêmica do coração (DIC). Diferenças metodológicas têm, entretanto, prejudicado a comparabilidade de alguns estudos. O objetivo desta investigação foi testar a associação do diabetes mellitus com a DIC, procedendo-se a ajustamentos para as possíveis variáveis de confusão e/ou modificadoras de efeito. Avaliou-se também a existência de um gradiente dose resposta para as variáveis duração do diabetes, duração da hipertensão arterial, duração da hipercolesterolemia, duração do hábito de fumar, no cigarros consumidos/dia e duração da menopausa. O estudo foi planejado sob a forma de um desenho tipo caso-controle, tendo-se utilizado a estratégia de compor cinco bancos de dados, onde os casos foram comparados com cinco diferentes conjuntos de controles. Manteve-se nas análises de cada banco de dados o mesmo elenco de possíveis variáveis de confusão e/ou modificadoras de efeito. A população do estudo foi constituída por indivíduos de ambos o sexos, na faixa etária de 30 a 69 anos completos, sendo todos residentes no município de São Paulo. O estudo teve início em março de 1993 e estendeu-se até fevereiro de 1994. A amostra total foi composta por 833 indivíduos. A técnica estatística utilizada para análise dos dados foi a regressão logística multivariada. Os resultados do estudo permitiram identificar o diabetes mellitus como um fator de risco independente para a doença isquêmica do coração (\"odds ratio\" ajustado=2,6; I.C.95 por cento : 1,18- -5,80). O achado consistente de um possível efeito de proteção na categoria intermediária de duração do diabetes (>5$<10 anos) conduziu à hipótese de que o controle metabólico da doença, no período, poderia estar exercendo tal influência sobre o risco de DIC. Foi também possível identificar um efeito independente para as variáveis hipertensão arterial, hipercolesterolemia, hábito de fumar e antecedentes familiares de cardiopatia. Verificou-se, de forma consistente, a presença de um gradiente linear para duração da hipertensão arterial e número de cigarros consumidos/dia. As interações consideradas de interesse, combinando-se história positiva de diabetes com as categorias de exposição das outras variáveis não apresentaram significância estatística. São discutidas algumas razões de ordem metodológica que exerceriam influência sobre a magnitude das medidas de efeito em diferentes combinações de controles. / Several authors have reported diabetes as an independent risk factor to ischaemic heart disease (IHD). However, the use of different methodologies have been an obstacle in comparing these studies. The objective of this investigation was to test the association between diabetes and IHD, after adjusting for known confounders and/or modifiers of effect. There was interest in evaluating the existence of a linear gradient for known duration of diabetes, arterial hypertension, hypercholesterolemia, menopause, smoking and daily number of cigarretes consumed. The study was designed as a case-control and the cases were compared with five different kinds of controls. The same group of variables were maintained in the analysis. The population was composed by male and female, aged 30-69 years living in the city of São Paulo. The period of the study was one year (march/93 until february/94). The sample included 833 individuais. Logistic regression was the statistical method to analysis of the data. The results showed that diabetes is an independent risk factor to lliD (adjusted odds ratio=2.6; C.I.95 per cent : 1.18-5.80). There was a consistent protection effect on the \">5 <1O\" years stratum of known duration of diabetes and it was proposed that metabolic control of diabetes during this period had some influence to the IHD risk. Hypertension, hypercholesterolemia, smoking and familial antecedents of cardiovascular diseases were considered major risk factors to IHD. It was detected a linear gradient for known duration of hypertension and daily number of cigarettes consumed. The interaction between diabetes and exposure levels of other variables did not present statistical significance. Some methodological issues are presented to explain different magnitudes of effect according to the different kinds o f controls.

Strong evidence has linked dietary sodium intake to blood pressure, but the effects of sodium intake on cardiovascular diseases (CVD) outcomes remain elusive, especially for older population. We examined the association between estimated usual sodium intake and CVD and all-cause mortality in a nationally representative sample of 4068 US adults aged 51 and older surveyed in 1988-1994. After a mean follow-up of 12.9 years from 1988 to 2006, 1680 participants died: 734 from CVD; 392 from ischemic heart disease (IHD); and 144 from stroke. In the Cox proportional models adjusted for sociodemographic variables and CVD risk factors, sodium intake was not significantly associated with all-cause, CVD, IHD and stroke mortality. No significant interactions were observed between sodium intake and sex, race/ethnicity, hypertension status, body mass index or physical activity for any of the outcomes studied. However, among Mexican-Americans sodium intake was significantly and linearly associated with CVD mortality.

Diversos autores têm apontado o diabetes como fator de risco independente para a doença isquêmica do coração (DIC). Diferenças metodológicas têm, entretanto, prejudicado a comparabilidade de alguns estudos. O objetivo desta investigação foi testar a associação do diabetes mellitus com a DIC, procedendo-se a ajustamentos para as possíveis variáveis de confusão e/ou modificadoras de efeito. Avaliou-se também a existência de um gradiente dose resposta para as variáveis duração do diabetes, duração da hipertensão arterial, duração da hipercolesterolemia, duração do hábito de fumar, no cigarros consumidos/dia e duração da menopausa. O estudo foi planejado sob a forma de um desenho tipo caso-controle, tendo-se utilizado a estratégia de compor cinco bancos de dados, onde os casos foram comparados com cinco diferentes conjuntos de controles. Manteve-se nas análises de cada banco de dados o mesmo elenco de possíveis variáveis de confusão e/ou modificadoras de efeito. A população do estudo foi constituída por indivíduos de ambos o sexos, na faixa etária de 30 a 69 anos completos, sendo todos residentes no município de São Paulo. O estudo teve início em março de 1993 e estendeu-se até fevereiro de 1994. A amostra total foi composta por 833 indivíduos. A técnica estatística utilizada para análise dos dados foi a regressão logística multivariada. Os resultados do estudo permitiram identificar o diabetes mellitus como um fator de risco independente para a doença isquêmica do coração (\"odds ratio\" ajustado=2,6; I.C.95 por cento : 1,18- -5,80). O achado consistente de um possível efeito de proteção na categoria intermediária de duração do diabetes (>5$<10 anos) conduziu à hipótese de que o controle metabólico da doença, no período, poderia estar exercendo tal influência sobre o risco de DIC. Foi também possível identificar um efeito independente para as variáveis hipertensão arterial, hipercolesterolemia, hábito de fumar e antecedentes familiares de cardiopatia. Verificou-se, de forma consistente, a presença de um gradiente linear para duração da hipertensão arterial e número de cigarros consumidos/dia. As interações consideradas de interesse, combinando-se história positiva de diabetes com as categorias de exposição das outras variáveis não apresentaram significância estatística. São discutidas algumas razões de ordem metodológica que exerceriam influência sobre a magnitude das medidas de efeito em diferentes combinações de controles. / Several authors have reported diabetes as an independent risk factor to ischaemic heart disease (IHD). However, the use of different methodologies have been an obstacle in comparing these studies. The objective of this investigation was to test the association between diabetes and IHD, after adjusting for known confounders and/or modifiers of effect. There was interest in evaluating the existence of a linear gradient for known duration of diabetes, arterial hypertension, hypercholesterolemia, menopause, smoking and daily number of cigarretes consumed. The study was designed as a case-control and the cases were compared with five different kinds of controls. The same group of variables were maintained in the analysis. The population was composed by male and female, aged 30-69 years living in the city of São Paulo. The period of the study was one year (march/93 until february/94). The sample included 833 individuais. Logistic regression was the statistical method to analysis of the data. The results showed that diabetes is an independent risk factor to lliD (adjusted odds ratio=2.6; C.I.95 per cent : 1.18-5.80). There was a consistent protection effect on the \">5 <1O\" years stratum of known duration of diabetes and it was proposed that metabolic control of diabetes during this period had some influence to the IHD risk. Hypertension, hypercholesterolemia, smoking and familial antecedents of cardiovascular diseases were considered major risk factors to IHD. It was detected a linear gradient for known duration of hypertension and daily number of cigarettes consumed. The interaction between diabetes and exposure levels of other variables did not present statistical significance. Some methodological issues are presented to explain different magnitudes of effect according to the different kinds o f controls.

Made available in DSpace on 2016-03-22T17:27:31Z (GMT). No. of bitstreams: 1 Carla Vandame.pdf: 690431 bytes, checksum: dd9d45b9cf1994563baa2596d4e66e46 (MD5) Previous issue date: 2014-03-25 / The aim of this study was to investigate the prevalence of dyslipidemia by differentiation of lipid fractions and its association with cardiovascular risk. Was cross-sectional study of patients over 60 years of Basic Health Units in the urban area of Pelotas. We collected information from medical records of individuals who looked for the period January to July 2013 and were selected elderly patients with at least one of the following: total cholesterol (TC ) &#8805; 240mg/dL, LDL - cholesterol ( LDL - c ) &#8805; 150, triglycerides ( TG ) &#8805; 160 and / or HDL- cholesterol ( HDL-C ) < 40. Was investigated further age, sex, smoking, hypertension, diabettes mellittus and previous history of coronary artery disease. The most common lipid abnormality was hypertriglyceridemia - 40.5. Both CT and the LDL-C were higher among women, with values of 27.9 % and 32.3 % respectively, p < 0.001 compared to LDL-C, noting that even in those aged 60 to 69 years, with values of 29.6 % for total cholesterol and 31.9 % for LDL-C (p < 0.001 ). Women were more dyslipidemic than men who had HDL-C with values less than 40mg/dL / O objetivo deste estudo foi investigar as prevalências de dislipidemia por diferenciação das frações lipídicas e sua associação com risco cardiovascular. Foi um estudo transversal, sobre pacientes acima de 60 anos das Unidades Básicas de Saúde da zona urbana da cidade de Pelotas. Coletaram-se informações dos prontuários dos indivíduos que consultaram no período de janeiro a julho de 2013 e selecionaram-se idosos que apresentaram pelo menos uma das seguintes situações: colesterol total (CT) &#8805; 240mg/dL, LDL-colesterol (LDL-C) &#8805; 150, triglicerídeos (TG) &#8805; 160 e/ou HDL-colesterol (HDL-C)<40. Investigou-se ainda idade, sexo, tabagismo, hipertensão arterial sistêmica, diabettes mellittus e história prévia de doença arterial coronariana. A alteração lipídica mais frequente foi a hipertrigliceridemia - 40,5. Tanto CT quanto o LDL-C foram mais elevados entre as mulheres, com valores de 27,9% e 32,3% respectivamente, com p< 0,001 em relação a LDL-C, observando-se isto ainda naqueles, com idades entre 60 e 69 anos, sendo os valores de 29,6% para o colesterol total e 31,9% para o LDL-C (p<0,001). As mulheres mostraram-se mais dislipidêmicas do que os homens os quais apresentaram fração HDL-C com valores inferiores a 40mg/dL

Background and aims. In patients consulting for chest pain, it is of great importance to evaluate the possibility of ischemic heart disease (IHD). The aims in this thesis were to investigate the accuracy of the general practitioners’ clinical assessments and the applicability of exercise testing and myocardial perfusion scintigraphy (MPS) in patients consulting for chest pain in primary care. Statins are known to prevent IHD. A further aim was therefore to investigate if a relation could be detected on a population basis between the use of statins and the morbidity of acute myocardial infarction (AMI). Methods. All patients from 20 to 79 years, consulting for a new episode of chest pain in three primary health care centres, were included during almost two years from 1998 to 2000. The patients were managed according to the clinical evaluation. The presence of IHD was excluded either by clinical examination only, or if stable IHD was in question, by exercise testing and if the exercise test was inconclusive by an additional MPS. If unstable IHD or myocardial infarction was suspected, referral for emergency hospital examination was made. Correlations between statin sales and the morbidity of AMI in Sweden’s municipalities were analysed in an ecological, register based study. Adjustment was made for sales of antidiabetics, socio-economic deprivation indexes and geographic coordinates. Results. Consultations for chest pain represented 1.5% of all consultations in the ages 20 to 79 and were made by 554 patients. In 281 patients IHD was excluded by clinical examination only. In 208 patients stable IHD and in 65 unstable IHD was in question. Four patients (1.4%) evaluated as not having IHD, were diagnosed with angina pectoris or AMI within three months. Exercise testing was performed in 191 patients and revealed no IHD in 134 and IHD in 14 patients. In 43 patients the exercise test results were equivocal. Thirty-nine of these patients underwent MPS, which showed no IHD in 20 and IHD in 19 of the patients. In a follow up almost six years later, neither mortality rate nor prevalence of IHD differed significantly between the 384 study patients evaluated not to have IHD and the population controls. Statin sales and AMI-incidence or mortality showed no strong associations from 1998 to 2002. Conclusions. ·Primary care is an appropriate level of care for ruling out IHD as the cause of chest pain, with sufficient safety and for diagnostics of stable IHD. ·Exercise testing and myocardial perfusion scintigraphy are useful procedures when investigating chest pain patients in primary care. ·The results indicate that preventive measures other than increased statin treatment should be considered to further decrease AMI-morbidity.

Growing evidence from animal and clinical studies suggests that cardiac cell therapy can restore perfusion and improve function in the ischemic/infarcted myocardium. However, cell therapy is hindered by insufficient cell numbers, inefficient cell homing and engraftment, and inadequate cellular interactions. Furthermore, the biological mechanisms and local effects of transplanted cells have not been well-elucidated. The research presented herein attempts to address some of these issues. In manuscript #1, a new subpopulation of circulating progenitor cells (CPCs), termed derived CD133+ cells, was generated from the CD133- fraction of human peripheral blood. The derived CD133+ progenitors appeared to have superior vasculogenic potential in vitro, which may prove to be beneficial in inducing vasculogenesis in ischemic tissues. Positron emission tomography (PET) with direct cell labeling and reporter gene techniques were employed to assess the fate of transplanted human CPCs in vivo at different subjects of investigation, and different stages of cell transplantation. In manuscript #2, PET imaging with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) direct cell labeling was used to demonstrate that collagen-based matrices improve the early homing and retention of delivered CPCs in a rat ischemic hindlimb model. This mechanism conferred by the matrix may have implications on cell therapy at the early stages after transplantation. In manuscript #3, a more efficient, stable and accurate labeling method, hexadecyl-4-[18F]fluorobenzoate (18F-HFB) direct cell labeling, was developed to quantify cell distribution of transplanted CPCs in a rat myocardial infarction model. PET imaging of 18F-HFB-CPCs revealed significant cell washout from the myocardium immediately after intramyocardial injection, with only a small proportion of transplanted CPCs remaining in the target area in the first 4 hours after delivery. In manuscript #4, human CPCs transduced with lentiviral vectors showed stable expression of PET reporter genes. This reporter gene based-cell labeling technique can be developed for noninvasive tracking cells within a bioengineered matrix by PET, while preserving cell phenotype, viability and function. These studies contribute important insights into the biology and physiology of transplanted stem cells and the ability of delivery matrices to improve transplanted cell engraftment, survival, and function. I believe with further refinement, cell expansion, tissue engineering and PET imaging could facilitate the clinical applications of cell therapies in years to come.

No description available.

Growing evidence from animal and clinical studies suggests that cardiac cell therapy can restore perfusion and improve function in the ischemic/infarcted myocardium. However, cell therapy is hindered by insufficient cell numbers, inefficient cell homing and engraftment, and inadequate cellular interactions. Furthermore, the biological mechanisms and local effects of transplanted cells have not been well-elucidated. The research presented herein attempts to address some of these issues. In manuscript #1, a new subpopulation of circulating progenitor cells (CPCs), termed derived CD133+ cells, was generated from the CD133- fraction of human peripheral blood. The derived CD133+ progenitors appeared to have superior vasculogenic potential in vitro, which may prove to be beneficial in inducing vasculogenesis in ischemic tissues. Positron emission tomography (PET) with direct cell labeling and reporter gene techniques were employed to assess the fate of transplanted human CPCs in vivo at different subjects of investigation, and different stages of cell transplantation. In manuscript #2, PET imaging with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) direct cell labeling was used to demonstrate that collagen-based matrices improve the early homing and retention of delivered CPCs in a rat ischemic hindlimb model. This mechanism conferred by the matrix may have implications on cell therapy at the early stages after transplantation. In manuscript #3, a more efficient, stable and accurate labeling method, hexadecyl-4-[18F]fluorobenzoate (18F-HFB) direct cell labeling, was developed to quantify cell distribution of transplanted CPCs in a rat myocardial infarction model. PET imaging of 18F-HFB-CPCs revealed significant cell washout from the myocardium immediately after intramyocardial injection, with only a small proportion of transplanted CPCs remaining in the target area in the first 4 hours after delivery. In manuscript #4, human CPCs transduced with lentiviral vectors showed stable expression of PET reporter genes. This reporter gene based-cell labeling technique can be developed for noninvasive tracking cells within a bioengineered matrix by PET, while preserving cell phenotype, viability and function. These studies contribute important insights into the biology and physiology of transplanted stem cells and the ability of delivery matrices to improve transplanted cell engraftment, survival, and function. I believe with further refinement, cell expansion, tissue engineering and PET imaging could facilitate the clinical applications of cell therapies in years to come.