The left ventricular contractility of the rat heart is modulated by changes in flow and a1-adrenoceptor stimulation

Myocardial contractility depends on several mechanisms such as coronary perfusion pressure (CPP) and flow as well as on a1-adrenoceptor stimulation. Both effects occur during the sympathetic stimulation mediated by norepinephrine. Norepinephrine increases force development in the heart and produces vasoconstriction increasing arterial pressure and, in turn, CPP. The contribution of each of these factors to the increase in myocardial performance needs to be clarified. Thus, in the present study we used two protocols: in the first we measured mean arterial pressure, left ventricular pressure and rate of rise of left ventricular pressure development in anesthetized rats (N = 10) submitted to phenylephrine (PE) stimulation before and after propranolol plus atropine treatment. These observations showed that in vivo a1-adrenergic stimulation increases left ventricular-developed pressure (P<0.05) together with arterial blood pressure (P<0.05). In the second protocol, we measured left ventricular isovolumic systolic pressure (ISP) and CPP in Langendorff constant flow-perfused hearts. The hearts (N = 7) were perfused with increasing flow rates under control conditions and PE or PE + nitroprusside (NP). Both CPP and ISP increased (P<0.01) as a function of flow. CPP changes were not affected by drug treatment but ISP increased (P<0.01). The largest ISP increase was obtained with PE + NP treatment (P<0.01). The results suggest that both mechanisms, i.e., direct stimulation of myocardial a1-adrenoceptors and increased flow, increased cardiac performance acting simultaneously and synergistically.

Determinação de estanho em tecidos de ratas por ICP-MS

Os organoestânicos, principalmente o tributilestanho (TBT), são contaminantes ambientais, utilizados principalmente em tintas anti-incrustantes para navios. Eles sofrem bioacumulação e podem ser encontrados em mamíferos, inclusive em seres humanos. A principal fonte de exposição é a ingestão de alimentos contaminados. Esse estudo possuiu como objetivo a determinação de estanho em tecidos de ratas expostas cronicamente a TBT utilizando espectrometria de massas com plasma acoplado indutivamente (ICP-MS). Ratas Wistar adultas foram usadas na experimentação, sendo divididas dois grupos: o grupo exposto a 100 ng kg-1 dia-1 de TBT por 15 dias e o grupo de referência que recebeu somente o veículo durante o mesmo período de exposição. Ao final da exposição, os animais foram sacrificados e coletados plasma, coração, rim, pulmão, fígado e ovário para análise. As amostras foram secas em estufa por 72 horas e pulverizadas. A determinação de estanho foi realizada por ICP-MS após a digestão ácida assistida por micro-ondas de uma amostra com aproximadamente 100 mg. O limite de detecção (LD) calculado foi 4,3 ng L-1, o que permite a determinação de estanho em amostras de tecidos de animais usados para experimentação. A exatidão foi verificada pela análise do material de referência certificado de urina, Seronorm Urine (54,6 ± 2,7 μg L-1), tendo como resultado 50,1 ± 3,8 μg L-1. A concentração de estanho foi determinada em amostras de plasma, coração, rim, pulmão, fígado e ovário do grupo exposto a TBT e do grupo controle. Houve diferença estatisticamente significativa entre os dois grupos para todas as amostras analisadas. As diferenças entre os grupos foram mais pronunciadas nas amostras de fígado e rim. Além disso, este estudo mostrou que a presença de estanho no organismo de ratas distribui-se pelos tecidos acarretando em alterações morfofisiológicas já descritas em ovários, coração e fígado

Application to quantify fetal lung branching on rat explants

Recently, regulating mechanisms of branching morphogenesis of fetal lung rat explants have been an essential tool for molecular research. The development of accurate and reliable segmentation techniques may be essential to improve research outcomes. This work presents an image processing method to measure the perimeter and area of lung branches on fetal rat explants. The algorithm starts by reducing the noise corrupting the image with a pre-processing stage. The outcome is input to a watershed operation that automatically segments the image into primitive regions. Then, an image pixel is selected within the lung explant epithelial, allowing a region growing between neighbouring watershed regions. This growing process is controlled by a statistical distribution of each region. When compared with manual segmentation, the results show the same tendency for lung development. High similarities were harder to obtain in the last two days of culture, due to the increased number of peripheral airway buds and complexity of lung architecture. However, using semiautomatic measurements, the standard deviation was lower and the results between independent researchers were more coherent

Automated image analysis of lung branching morphogenesis from microscopic images of fetal rat explants

Background: Regulating mechanisms of branching morphogenesis of fetal lung rat explants have been an essential tool for molecular research. This work presents a new methodology to accurately quantify the epithelial, outer contour and peripheral airway buds of lung explants during cellular development from microscopic images. Methods: The outer contour was defined using an adaptive and multi-scale threshold algorithm whose level was automatically calculated based on an entropy maximization criterion. The inner lung epithelial was defined by a clustering procedure that groups small image regions according to the minimum description length principle and local statistical properties. Finally, the number of peripheral buds were counted as the skeleton branched ends from a skeletonized image of the lung inner epithelial. Results: The time for lung branching morphometric analysis was reduced in 98% in contrast to the manual method. Best results were obtained in the first two days of cellular development, with lesser standard deviations. Non-significant differences were found between the automatic and manual results in all culture days. Conclusions: The proposed method introduces a series of advantages related to its intuitive use and accuracy, making the technique suitable to images with different lightning characteristics and allowing a reliable comparison between different researchers.

Automated image analysis of lung branching morphogenesis

Regulating mechanisms of branchingmorphogenesis of fetal lung rat explants have been an essential tool formolecular research.This work presents a new methodology to accurately quantify the epithelial, outer contour, and peripheral airway buds of lung explants during cellular development frommicroscopic images. Methods.Theouter contour was defined using an adaptive and multiscale threshold algorithm whose level was automatically calculated based on an entropy maximization criterion. The inner lung epithelium was defined by a clustering procedure that groups small image regions according to the minimum description length principle and local statistical properties. Finally, the number of peripheral buds was counted as the skeleton branched ends from a skeletonized image of the lung inner epithelia. Results. The time for lung branching morphometric analysis was reduced in 98% in contrast to themanualmethod. Best results were obtained in the first two days of cellular development, with lesser standard deviations. Nonsignificant differences were found between the automatic and manual results in all culture days. Conclusions. The proposed method introduces a series of advantages related to its intuitive use and accuracy, making the technique suitable to images with different lighting characteristics and allowing a reliable comparison between different researchers.

Application to quantify fetal lung branching on rat explant

Recently, regulating mechanisms of branching morphogenesis of fetal lung rat explants have been an essential tool for molecular research. The development of accurate and reliable segmentation techniques may be essential to improve research outcomes. This work presents an image processing method to measure the perimeter and area of lung branches on fetal rat explants. The algorithm starts by reducing the noise corrupting the image with a pre-processing stage. The outcome is input to a watershed operation that automatically segments the image into primitive regions. Then, an image pixel is selected within the lung explant epithelial, allowing a region growing between neighbouring watershed regions. This growing process is controlled by a statistical distribution of each region. When compared with manual segmentation, the results show the same tendency for lung development. High similarities were harder to obtain in the last two days of culture, due to the increased number of peripheral airway buds and complexity of lung architecture. However, using semiautomatic measurements, the standard deviation was lower and the results between independent researchers were more coherent.

Effects of an exercise training program in physical condition after liver transplantation in familial amyloidotic polyneuropathy: a case report

Introduction: Familial amyloidotic polyneuropathy (FAP) is a neurodegenerative disease that leads to sensory and motor polyneuropathies as well as functional limitations. So far, liver transplantation is the only treatment for FAP because the mutated protein causing the disease is mainly produced in the liver. With the increasing survival of transplant recipients, functional and cardiovascular problems as consequences of immunosuppressant side effects are increasing associated with sedentary lifestyles and/or retransplantation status. We sought to analyze the impact of exercise training programs on 1 FAP patient’s course long-term after liver transplantation. Methodology. A FAP patient (female; 49 years of age; body mass index 18.8 kg/m2) underwent a liver transplantation 133 months before assessment. She was assessed for body composition, isometric quadriceps muscle strength, functional capacity, fatigue, and levels of physical activity before and after a 6-month period of combined exercise training. Results: After the exercise training program, almost all variables were improved, namely, total body skeletal muscle mass, proximal femoral bone mineral density, quadriceps strength, maximal oxygen consumption on 6 minutes walk test (6mwt) or VO2peak, total ventilation on 6mwt, and fatigue. The improvement in distance on 6mwt (69.2 m) was clinically significant. Preintervention the levels of physical activity were below international recommendations for health; after the program they achieved the recommendations. Conclusion: The results showed an improvement in functional capacity with a decrease in future disability risk associated with a better lifestyle with respect to physical activity levels in 1 patient.

Geographical patterns of proportionate mortality for the most common causes of death in Brazil

Mortality due to chronic diseases has been increasing in all regions of Brazil with corresponding decreases in mortality from infectious diseases. The geographical variation in proportionate mortality for chronic diseases for 17 Brazilian state capitals for the year 1985 and their association with socio-economic variables and infectious disease was studied. Calculations were made of correlation coefficients of proportionate mortality for adults of 30 years or above due to ischaemic heart disease, stroke and cancer of the lung, the breast and stomach with 3 socio-economic variables, race, and mortality due to infectious disease. Linear regression analysis included as independent variables the % of illiteracy, % of whites, % of houses with piped water, mean income, age group, sex, and % of deaths caused by infectious disease. The dependent variables were the % of deaths due to each one of the chronic diseases studied by age-sex group. Chronic diseases were an important cause of death in all regions of Brazil. Ischaemic heart diseases, stroke and malignant neoplasms accounted for more than 34% of the mortality in each of the 17 capitals studied. Proportionate cause-specific mortality varied markedly among state capitals. Ranges were 6.3-19.5% for ischaemic heart diseases, 8.3-25.4% for stroke, 2.3-10.4% for infections and 12.2-21.5% for malignant neoplasm. Infectious disease mortality had the highest (p < 0.001) correlation with all the four socio-economic variables studied and ischaemic heart disease showed the second highest correlation (p < 0.05). Higher socio-economic level was related to a lower % of infectious diseases and a higher % of ischaemic heart diseases. Mortality due to breast cancer and stroke was not associated with socio-economic variables. Multivariate linear regression models explained 59% of the variance among state capitals for mortality due to ischaemic heart disease, 50% for stroke, 28% for lung cancer, 24% for breast cancer and 40% for stomach cancer. There were major differences in the proportionate mortality due to chronic diseases among the capitals which could not be accounted for by the social and environmental factors and by the mortality due to infectious disease.

Health related quality of life in patients with refractory chronic heart failure undergoing cardiac resynchronization: type of therapeutic response

The benefits of cardiac resynchronization therapy (CRT) in the health-related quality of life (HRQL) are largely demonstrated in selected patients with severe congestive heart failure (CHF). However, the differences between responders and non-responders, with regard to the effect of CRT in the various dimensions that constitute HRQL are still a matter of discussion. Objective: To evaluate the impact of CRT on the HRQL of patients with CHF refractory to optimal pharmacological therapy, within 6 months after CRT. Methods: 43 patients, submitted to successful implantation of CRT, were evaluated in hospital just before intervention and in the outpatient clinic within 6 months after CRT. HRQL was analyzed based on the Kansas City Cardiomyopathy Questionnaire (KCCQ). Patients were classified as super-responders (ejection fraction of left ventricle - LVEF - ≥45% post-CRT), n=15, responders (sustained improvement in functional class and LVEF increased by 15%), n=19, and non-responders (no clinical or LVEF improvement), n=9. Results: In the group of super-responders, CRT was associated with an improvement in HRQL for the various fields and sums assessed (ρ<0.05); in responders, CRT has been associated with an improvement of HRQL in the various fields and sums, except in the self-efficacy dimension (ρ<0.05); in non-responders, CRT was not associated with improvement of HRQL. Conclusion: In a population with severe CHF undergoing CRT, the patients with clinical and echocardiographic positive response, obtained a favorable impact in all dimensions of HRQL, while the group without response to CRT showed no improvement. These data reinforces the importance of HRQL as a multidimensional tool for assessment of benefits in clinical practice.

Rise and fall in ischemic heart disease mortality: it may have happened before

The rise in ischemic heart disease(IHD) mortality occurring mostly during the first half of the 20th century is usually associated with economic development and its consequences for people's lifestyles. On the basis of historical evidence, it is postulated that a previous IHD epidemic cycle may have occurred in England and Wales towards the turn of the nineteenth century. The implications of this on causal theories and current etiological research on atherosclerosis are discussed.

Evaluating the quality of life in patients with refractory chronic heart failure undergoing cardiac resynchronization regarding the type of therapeutic response

The benefits of cardiac resynchronization therapy (CRT) in the quality of life have been largely demonstrated in selected patients with severe congestive heart failure (CHF). However, the differences between responders and non-responders, with regard to the effect of CRT in the various dimensions of quality of life is still a matter of discussion. Objective: to evaluate the impact of CRT on the quality of life of patients with CHF refractory to optimal pharmacological therapy, within 6 months after CRT.

Relation of happiness, hope and affection with quality of life in patients with heart failure

Introduction: Meeting the actual role of positive psychology, begins to be recognized the relation of positive variables with health. Objective: To know the relation of happiness, hope and affection with quality of life in individuals with heart failure. Population and Methodology: 128 individuals with heart failure, 98 men and 30 women, 61.9±12,1 years of age, 6,6±3,9 years in school and 74,2% retired because of this disease. 56,3% were in Class III of New York Heart Association, with poor left ventricular ejection fraction (25,3±6,2%). The clinical history was of 9,4±8,5 years for this heart disease and had at least one hospitalization due to heart failure with 51,6% having ischemic heart disease.

Happiness, hope and affection as predictors of quality of life and functionality of individuals with heart failure at 3 month follow up

Introduction: Meeting the actual role of positive psychology, begins to be recognized the contribution of positive variables in health outcomes. Objective: To know the contribution of happiness, hope and affection individually and as a whole in the quality of life and functionality of individuals with heart failure. Population and Methodology: 128 individuals with heart failure, 98 men and 30 women, 61.9±12,1 years of age, 6,6±3,9 years of school and 74,2% retired because of this disease. 56,3% were in Class III of New York Heart Association, with poor left ventricular ejection fraction (25,3±6,2%). The clinical history was of 9,4±8,5 years for this heart disease and had at least one hospitalization due to heart failure with 51,6% having ischemic heart disease.