921 resultados para Sistema cardiovascular - Doenças


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No período da menopausa, a incidência de doenças cardiovasculares em mulheres é equivalente a dos homens, e assim os gastos públicos com saúde nesta população em particular, aumentam significativamente, uma vez que as mulheres possuem maior longevidade se comparadas aos homens. Os mecanismos celulares e/ou moleculares pelos quais ocorre maior incidência de hipertensão arterial em mulheres após a menopausa ainda não são claros. Uma variedade de fatores parece contribuir para a elevação de pressão arterial na menopausa, entre eles destacam-se a deficiência de estrogênio, o aumento do estresse oxidativo, a disfunção endotelial, a elevação da atividade do sistema renina-angiotensina, a elevação nos níveis plasmáticos de testosterona, as alterações no perfil lipídico e o aumento no ganho de peso. Trabalhos prévios mostram que os efeitos benéficos do exercício físico sobre o sistema cardiovascular estão relacionados a maior produção de óxido nítrico e/ou sua biodisponibilidade para o músculo liso vascular. Este último mecanismo tem sido relacionado com elevação da atividade da enzima antioxidante superóxido dismutase (SOD), que representa um importante mecanismo de defesa celular contra a formação de radicais livres. Objetivo: avaliar os níveis plasmáticos da enzima superóxido dismutase em resposta a um programa de treinamento físico aeróbio por 8 semanas realizado em mulheres no climatério. Métodos: A amostra foi constituída por 31 mulheres normotensas (49,3±1,2 anos) e 15 hipertensas (52,2±1,6 anos) todas diagnosticadas no período do climatério e sedentárias... (Resumo completo, clicar acesso eletrônico abaixo)

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A incidência de doenças cardiovasculares tem se constituído na maior causa de morbimortalidade em todo mundo, especialmente após os 50 anos de idade, e têm sido associadas à presença de polimorfismos em alguns genes, especialmente o gene da eNOS. Apesar das mulheres compartilharem com os homens os diversos fatores de risco para o desenvolvimento das doenças cardiovasculares, entre elas hipertensão arterial e dislipidemia, estudos epidemiológicos mostram que as mesmas, antes da menopausa, apresentam menor risco cardiovascular quando comparadas aos homens. Entretanto, após o período da menopausa há um aumento significativo na incidência de hipertensão arterial e suas complicações. Este fato parece estar relacionado a uma possível ação protetora exercida pelos hormônios sexuais femininos, sobretudo os estrogênios que apresentam queda abrupta no período da menopausa. O óxido nítrico (NO), produzido pelas células endoteliais através da enzima eNOS, desempenha importante papel no sistema cardiovascular, participando na regulação do fluxo sanguíneo, do remodelamento vascular e na atividade plaquetária. Assim, estudos envolvendo o gene responsável pela síntese da enzima eNOS, tem sido foco de várias pesquisas na tentativa de avaliar se a presença dos polimorfismos poderia predispor os indivíduos a maior incidência de doenças cardiovasculares. O polimorfismo do gene da eNOS na posição G894T/Glu298Asp localizado no éxon 7, implica na alteração da sequência protéica, tornando a proteína mais suscetível à clivagem, tendo consequências funcionais como a redução do NO demonstrando assim sua provável contribuição para a disfunção endotelial e consequente aumento da pressão arterial. Com relação ao Íntron 4 caracterizado por um Número Variável de Repetições em Tandem... (Resumo completo, clicar acesso eletrônico abaixo)

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Plumbism is considered the oldest occupational disease. Among the pathophysiological effects associated with lead (Pb) are cardiovascular disorders. Many diseases that develop later in life are determined during the early stages of life, under the influence of exposure and preferred diet of the mother. Still, one should consider that many environmental contaminants at levels not harmful can determine pathophysiological processes if physical or chemical stressors and/or pathological conditions are present. In this context, the intrauterine malnutrition may represent an additional risk factor in exposure to Pb during pregnancy and lactation. For these reasons, the objective of this study was to evaluate the cardiovascular risk of weaned rats that have suffered perinatal exposure to Pb and intrauterine malnutrition, alone or in combination. After mating, female rats were divided into control (ctrl, ad libitum), food restriction (RA, the same diet 50% of consumption in the control group during pregnancy), exposed to Pb (500 ppm Pb in drinking water during pregnancy and lactation) and association (As, received the last two procedures in combination). Cumulative concentration-effect curves (CECs) to CaCl2 and noradrenaline (NA) were obtained in rings with and without endothelium of the same thoracic aorta from male weaned rats (23-25 days old). Maternal weight, litter weight, weight and number of pups at birth, anogenital distance, arterial blood pressure (ABP) and weight of tissues (kidney, liver, aorta, left ventricle) were evaluated. Changes in vascular reactivity were assessed by the maximum response (MR) and 50% effective concentration (EC50). Data were presented as mean ± SEM. Statistical analysis was performed by multifactorial analysis of variance and Tukey's post test. Body weight of dams did not differ between the experimental groups, except on the...(Complete abstract click electronic access below)

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Pós-graduação em Fisioterapia - FCT

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Pós-graduação em Fisiopatologia em Clínica Médica - FMB

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Currently individuals are affected by a routine busy and they don't have time for physical activity, highlighting the sedentary lifestyle, a risk factor for cardiovascular diseases. For this reason, it focuses too much on cardiovascular diseases and the importance of physical practice. With the largest divulgation and variety of physical activities, activities that were not as practiced became popular, as is the case of resistive exercise. Much is said of the influence of resistance exercise in physical strength, in muscle development and in the quest for a more defined body. However, studies have shown beneficial contributions of resistance exercise on the cardiovascular system. During the physical effort, some changes occur in the body in order to meet the increased demand for oxygen. Among them is the increase in heart rate (HR), which varies with the intensity of effort. Thus, this research sought to contribute with an analysis of the HR behavior before, during and after 3 sets of hypertrophy, as far for the flexor group of the elbow as to the extensor group. It was observed that, although the HR has increased in the course of the series, the variations of HR were not significant between the flexor group and extensor group of the elbow joint. Also were not significant the differences between the variations of the HR from the 1ª to the 2ª series between the flexor group and extensor group, as well as to the variations from the 2ª to the 3ª series

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

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Introduction: The circadian system has neural projections for the Autonomic Nervous System (ANS), directly interfering with sympathetic-vagal modulation of the cardiovascular system. Disturbances in the circadian system, such as phase changes in light-dark cycle (LD), has been related to the risk of development of cardiovascular diseases due to increased sympathetic tone and reduction o Heart Rate Variability (HRV - RR intervals). Purpose: Investigate the interaction between Circadian Timing System and cardiac autonomic control in rats. Materials and methods: We used 18 Wistar rats (♀, age = 139.9 ± 32.1 days, weight = 219.5 ± 16.2 g), divided into three distinct groups: Control (CG), phase delay of 6h (GDe) and phase advance of 6h (GAd). Three animals were excluded during data collection (CG/GDe/GAd - n=5). Telemeters were surgically implanted in each animal for continuous acquisition of electrocardiographic (ECG) signals (duration of 21 days in the CG and 28 days in GDe/ GAd). A LD cycle was established 12h: 12h, beginning of light at18:00h and dark at 06:00h. The animals remained in the same CG LD cycle throughout the experimental period, while, on the 14th day of registration, the GDe and GAd underwent a delay and an advance in 6h, respectively. Throughout the experimental period, the locomotor activity (LA), the mean heart rate (mHR) and variables related to iRR [mean RR (mRR), SDNN, RMSSD, LF, HF and LF/ HF ratio ] were recorded. All data were analyzed in blocks of 3 and 7 days, for the presence of circadian rhythm, values of Cosinor - mesor, amplitude and acrophase (paired t test), phase relationship, differences between light and dark (t test independent), averages every 30 minutes along each time series (two-way ANOVA with post hoc Bonferroni). The data block B1,M1 and M2 in CG served as benchmarks for comparisons between series of analysis of the GAT/GAV. Results: We observed circadian rhythmicity in the variables LA, mRR and mFC(p<0.01). mRR and mFC showed phase relationship with the LA in all three groups, being less stable in GAd. In the CG, no significant differences between blocks were found in any of the analyzes(p>0.05). Among the 7 day blocks, there was a significant reduction in mRR(p=0.04) and mFC(p=0.03) in GDe and significant reduction in HF mean(p=0.02) in GAd; and between 3 day blocks, a significant increase of LF/HF(p= 0.04) in the GDe; besides mRR(p=0.03), SDNN(p=0.04), RMSSD (p=0.04), LF (p=0.01) and HF(p=0.02) significant increase in the GAd. It was found that the differences between the means of the mRR, LA and mFC in light and dark phases were not significant after phase changes in some of the blocks/moments (GDe and GAd). No significant results were found when comparing rhythmic variables means every 30 minutes over the blocks, except for a significant decrease in mRR at the middle of the dark phase (B2) and the start of light phase (B3) - (p<0.01). Conclusion: phase advances and delays (6h) altered cardiac autonomic control in the experimental groups by temporarily HRV decrease. Phase advances apparently had greater negative interference in this process, in relation to the phase delays.

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Se ha realizado el modelado orientado a objetos del sistema de control cardiovascular en situaciones de diálisis aplicando una analogía eléctrica en el que se emplean componentes conectados mediante interconexiones. En este modelado se representan las ecuaciones diferenciales del sistema cardiovascular y del sistema de control barorreceptor así como las ecuaciones dinámicas del intercambio de fluidos y solutos del sistema hemodializador. A partir de este modelo se ha realizado experiencias de simulación en condiciones normales y situaciones de hemorragias, transfusiones de sangre y de ultrafiltración e infusión de fluido durante tratamiento de hemodiálisis. Los resultados obtenidos muestran en primer lugar la efectividad del sistema barorreceptor para compensar la hipotensión arterial inducida por los episodios de hemorragia y transfusión de sangre. En segundo lugar se muestra la respuesta del sistema de control ante diferentes tasas de ultrafiltración durante la hemodiálisis y se sugieren valores óptimos para la adecuada operación.

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Cardiovascular disease (CVD) is the leading cause of death worldwide. With atherosclerosis as the underlying cause for many CVD events, prevention or reduction of subclinical atherosclerotic plaque burden (SAPB) through a healthier lifestyle may have substantial public health benefits. The objective was to describe the protocol of a randomized controlled trial investigating the effectiveness of a 30-month worksite-based lifestyle program aimed to promote cardiovascular health in participants having a high or a low degree of SAPB compared with standard care. We will conduct a randomized controlled trial including middle-aged bank employees from the Progression of Early Subclinical Atherosclerosis cohort, stratified by SAPB (high SAPB n = 260, low SAPB n = 590). Within each stratum, participants will be randomized 1:1 to receive a lifestyle program or standard care. The program consists of 3 elements: (a) 12 personalized lifestyle counseling sessions using Motivational Interviewing over a 30-month period, (b) a wrist-worn physical activity tracker, and (c) a sit-stand workstation. Primary outcome measure is a composite score of blood pressure, physical activity, sedentary time, body weight, diet, and smoking (ie, adapted Fuster-BEWAT score) measured at baseline and at 1-, 2-, and 3-year follow-up. The study will provide insights into the effectiveness of a 30-month worksite-based lifestyle program to promote cardiovascular health compared with standard care in participants with a high or low degree of SAPB.