Endobronchial myxoma: Case report

INTRODUCTION: Pulmonary myxoma is an extremely rare benign neoplasm. It is mostly parenchymal but may occasionally occur within the tracheobronchial tree. There are very few reports of endobronchial myxoma. CASE REPORT: We describe a case of endobronchial myxoma in a 40-year-old female patient with a history of asthma and repeated right-sided pneumonia. Thoracic computed tomography (CT) showed medium lobe atelectasis. Fiber optic bronchoscopy revealed a polypoid, well-circumscribed tumor, causing total obstruction of the medium lobe bronchus. Biopsy of the mass was non-diagnostic. Further study included a positron emission tomography (PET) which demonstrated low metabolic activity of the tumor and no evidence of neoplasia in other location. The patient was submitted to a medium lobectomy and microscopic examination of the tumor revealed myxoid stroma with lobulated pattern, elongated and stellate cells, compatible with myxoma. CONCLUSION: Pulmonary myxoma is extraordinary rare and endobronchial location is very few reported in medical literature

Influência da oxidação de glicose sobre a função miocárdica de ratos obesos

Obesidade é uma doença metabólica crônica definida pelo acúmulo excessivo do tecido adiposo em relação à massa magra tecidual. Estudos clínicos mostram que a obesidade está associada à disfunção ventricular diastólica e não consistente comprometimento do desempenho sistólico. Os modelos experimentais que induzem obesidade por dietas têm sido utilizados como alternativa para se estudar as conseqüências das anormalidades cardíacas decorrentes do acúmulo de gordura. Pesquisas mostram que a função cardíaca em animais obesos pode estar preservada, diminuída ou aumentada. Alterações nos substratos energéticos, inibição da via glicolítica pelos ácidos graxos e redução na atividade da enzima piruvato desidrogenase (PDH) podem contribuir para a disfunção cardíaca induzida pela obesidade. Em razão da ausência de pesquisas que avaliaram a relação entre função cardíaca e metabolismo energético na obesidade, o objetivo deste estudo foi testar a hipótese que o desequilíbrio energético miocárdico, entre ácidos graxos e glicose, ocasionado pela obesidade, acarreta disfunção cardíaca. O prejuízo funcional nos animais obesos é decorrente de déficit de adenosina trifosfato (ATP), via glicolítica, para a bomba de cálcio (Ca2+) do retículo sarcoplasmático (SERCA2). Com a finalidade de testar esta hipótese, foi inibida a via glicolítica miocárdica pela administração do iodoacetato. Além disso, o metabolismo energético também foi avaliado pela estimulação da PDH pelo dicloroacetato. Ratos Wistar machos, com 30 dias, foram distribuídos em dois grupos: controle (C; n=30) e obeso (Ob; n=30). Os ratos C receberam ração padrão para roedores e os Ob um ciclo de quatro rações hiperlipídicas por um período de 30 semanas. A gordura corporal total foi realizada pela somatória dos depósitos epididimal, retroperitoneal...Obesity is a chronic metabolic disorder defined by excessive accumulation of body fat relative to lean tissue. Clinical studies show that obesity is associated with ventricular dysfunction and not consistent impairment of systolic performance. Experimental models that induce obesity by diet have been used as an alternative to study the consequences of cardiac abnormalities resulting from accumulation of fat. Researchs show that cardiac function in obese animals may be preserved, diminished or increased. Alterations in energy substrates, inhibition of the glycolytic pathway by fatty acids and reduced activity of the enzyme pyruvate dehydrogenase (PDH) may contribute to cardiac dysfunction induced by obesity. Due to the lack of research evaluating the relationship between cardiac function and energy metabolism in obesity, the objective of this study was to test the hypothesis that the myocardial energy imbalance between fatty acids and glucose, caused by obesity, leads to cardiac dysfunction. The functional impairment in the obese animals is due to deficit of adenosine triphosphate (ATP), glycolytic pathway for calcium (Ca2+) pump of sarcoplasmic reticulum (SERCA2). For this purpose, was inhibited the myocardial glycolytic pathway by administration of iodoacetate. Moreover, energy metabolism was also assessed by stimulation of PDH by dichloroacetate. Thirty-day-old male Wistar rats were assigned to one of two groups (n=30 each): control (C) and obese (Ob). The C group was fed a standard diet and Ob group was fed cycles of four highfat diets for 30 weeks. The total body fat was measured from the sum of the individual fat pad weights (epididymal, retroperitoneal and visceral) and the obesity defined by adiposity index. The nutritional and metabolic profiles of these animals were also evaluated. The cardiac remodeling process was assessed by structural and functional analysis... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Influência da dieta hiperlipídica ricas em ácidos graxos saturados sobre o metabolismo, estrutura e função cardíaca de ratos com estenose aórtica supravalvar

After an aggression, the heart undergoes remodeling to maintain its function stable; however, cardiac remodeling (CR) is time dependent and, in long term, may be harmful. The supravalvular aortic stenosis (AS) has been used to promote gradual development of left ventricular hypertrophy. It was observed that rats develop left ventricular hypertrophy, diastolic dysfunction and improved systolic function after 2 and 6 weeks of AS. After 12 weeks, diastolic dysfunction is maintained and systolic performance deteriorates; around the 18th week, systolic dysfunction is accentuated and signs of heart failure appear. Different factors could contribute to the dysfunction in the experimental model of AS, such as oxygen or energy substrate deficit. Under normal aerobic conditions, approximately 70% of myocardial energy production comes from fatty acid metabolism, and glycolysis contribution is around 30%. Studies have showed that the responsible factor for the choice of cardiac energy substrate is the elevated plasma levels of fatty acids and triglycerides. Studies that used experimental models of heart failure found that the increase in energy supply by lipids did not change or improved RC. The aim of this study was to test the hypothesis that the increased energy availability derived from lipids rich in saturated fatty acids restores myocardial energy balance, attenuating the pathological remodeling process. In order to test this hypothesis, we have evaluated the myocardial structure, function and metabolism of rats with AS fed with saturated high-fat diet. Male Wistar rats, 21 days old, were distributed into control group (Sham) or supravalvular aortic stenosis (AS); 6 weeks after surgery, rats were redistributed into two groups: fed with saturated high-fat diet or normolipidic diet (AS-N, n=12; Sham-N, n=14; AS-H, n=14 and Sham-H, n=14). The nutritional profile was determined. RC was characterized by the ...Após uma agressão, o coração remodela-se para manter estável a sua função; entretanto, a remodelação cardíaca (RC) é tempo dependente e a longo prazo pode ser prejudicial. A estenose aórtica supravalvar (EAo) tem sido utilizado para promover o desenvolvimento gradual de hipertrofia ventricular esquerda. Constatouse que ratos desenvolvem hipertrofia ventricular esquerda, disfunção diastólica e melhoria da função sistólica após 2 e 6 semanas de EAo, manutenção da disfunção diastólica e deterioração do desempenho sistólico na 12ª semana e, na 18ª semana há acentuação da disfunção sistólica e aparecimento de insuficiência cardíaca. Diferentes fatores poderiam contribuir para a disfunção no modelo experimental de EAo como o déficit de oxigênio ou de substrato energético. Em condições aeróbicas normais, aproximadamente 70% da produção de energia miocárdica deriva do metabolismo de ácidos graxos, sendo a contribuição glicolítica em torno de 30%. Estudos mostram que o fator responsável pela escolha do substrato energético cardíaco são os níveis plasmáticos elevados de ácidos graxos e triglicérides. Estudos utilizando modelos experimentais de insuficiência cardíaca constataram que o aumento na oferta de energia por lipídeos, não alteraram ou promoveram melhoria da RC. O objetivo deste trabalho foi testar a hipótese que a maior disponibilidade de energia proveniente dos lipídeos ricos em ácidos graxos saturados restaura o equilíbrio energético miocárdico, atenuando o processo de remodelação patológica (RP). Com a finalidade de testar esta hipótese, foram avaliadas a estrutura, a função e o metabolismo miocárdico de ratos com EAo, tratados com dieta hiperlipídica saturada. Foram utilizados ratos Wistar machos, com 21 dias de idade, separados em grupo controle (Sham) e estenose aórtica supravalvar (EAo); após 6 semanas da cirurgia, os ratos foram redistribuídos em mais dois ...Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

A possible increase of activity of endothelial l-arginine/nitric oxide pathway in aortas of diet-induced obesity rats

The obesity is associated with cardiovascular disorders. The aim of present purpose was test the hypothesis that the diet-induced obesity is able to generate a vascular adaptive response in aortic rings; this response could be mediated by NO pathway. The present work used Thirty-day-old male Wistar rats (70-100 g) were distributed into two groups: control (C) and obese (Ob). The obesity was induced through of hypercaloric diet during 15 weeks, the vascular response was assessed through different protocols of vascular reactivity studies and characterization of obesity was also evaluated. The obesity was characterized for decreased of glucose tolerance, hyperinsulinemia, hyperleptinemia and rise of adiposity index. In relation to vascular alterations, the diet-induced obesity generated decreased maximal response to noradrenaline, response which was abolished with presence of L-NAME, and increased relaxing to acetylcholine. There was no difference between groups in the blood pressure. The vascular responses observed in present work might have occurred with the aim of decrease of cardiovascular risk linked with obesity pathology; these findings suggest that obesity can be considered a paradoxical disorder.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Multivariate analysis for selecting animals for experimental research

Background Several researchers seek methods for the selection of homogeneous groups of animals in experimental studies, a fact justified because homogeneity is an indispensable prerequisite for casualization of treatments. The lack of robust methods that comply with statistical and biological principles is the reason why researchers use empirical or subjective methods, influencing their results. Objective To develop a multivariate statistical model for the selection of a homogeneous group of animals for experimental research and to elaborate a computational package to use it. Methods The set of echocardiographic data of 115 male Wistar rats with supravalvular aortic stenosis (AoS) was used as an example of model development. Initially, the data were standardized, and became dimensionless. Then, the variance matrix of the set was submitted to principal components analysis (PCA), aiming at reducing the parametric space and at retaining the relevant variability. That technique established a new Cartesian system into which the animals were allocated, and finally the confidence region (ellipsoid) was built for the profile of the animals’ homogeneous responses. The animals located inside the ellipsoid were considered as belonging to the homogeneous batch; those outside the ellipsoid were considered spurious. Results The PCA established eight descriptive axes that represented the accumulated variance of the data set in 88.71%. The allocation of the animals in the new system and the construction of the confidence region revealed six spurious animals as compared to the homogeneous batch of 109 animals. Conclusion The biometric criterion presented proved to be effective, because it considers the animal as a whole, analyzing jointly all parameters measured, in addition to having a small discard rate

Análise multivariada na seleção de animais em pesquisas experimentais

Background: Several researchers seek methods for the selection of homogeneous groups of animals in experimental studies, a fact justified because homogeneity is an indispensable prerequisite for casualization of treatments. The lack of robust methods that comply with statistical and biological principles is the reason why researchers use empirical or subjective methods, influencing their results. Objective: To develop a multivariate statistical model for the selection of a homogeneous group of animals for experimental research and to elaborate a computational package to use it. Methods: The set of echocardiographic data of 115 male Wistar rats with supravalvular aortic stenosis (AoS) was used as an example of model development. Initially, the data were standardized, and became dimensionless. Then, the variance matrix of the set was submitted to principal components analysis (PCA), aiming at reducing the parametric space and at retaining the relevant variability. That technique established a new Cartesian system into which the animals were allocated, and finally the confidence region (ellipsoid) was built for the profile of the animals’ homogeneous responses. The animals located inside the ellipsoid were considered as belonging to the homogeneous batch; those outside the ellipsoid were considered spurious. Results: The PCA established eight descriptive axes that represented the accumulated variance of the data set in 88.71%. The allocation of the animals in the new system and the construction of the confidence region revealed six spurious animals as compared to the homogeneous batch of 109 animals. Conclusion: The biometric criterion presented proved to be effective, because it considers the animal as a whole, analyzing jointly all parameters measured, in addition to having a small discard rate.Fundamento: Muitos pesquisadores buscam métodos para a seleção de grupos homogêneos de animais em pesquisas experimentais, fato que se justifica por ser a homogeneidade pré-requisito indispensável à casualização de tratamentos. A ausência de métodos robustos, que atendam a princípios estatísticos e biológicos, faz com que os pesquisadores utilizem métodos empíricos ou subjetivos, influenciando seus resultados. Objetivo: Desenvolver modelo estatístico multivariado para a seleção de grupo homogêneo de animais para pesquisas experimentais e elaborar pacote computacional que o operacionalize. Métodos: O conjunto de dados ecocardiográficos de 115 ratos Wistar, machos, com estenose aórtica (EAo) supravalvular foi utilizado para exemplificar o desenvolvimento do modelo. Inicialmente, os dados foram padronizados, tornando-se adimensionais. Em sequência, submeteu-se a matriz de variabilidade do conjunto à análise de componentes principais (ACP) buscando-se reduzir o espaço paramétrico e conservar a variabilidade relevante. Essa técnica estabeleceu um novo sistema cartesiano em que os animais foram alocados e, finalmente, construiu-se a região de confiança (elipsoide) para o perfil de respostas homogêneas dos animais. Os que se situaram no interior do elipsoide foram considerados pertencentes ao grupo homogêneo; caso contrário, espúrios ao grupo. Resultados: A ACP estabeleceu oito eixos descritores que representaram a variabilidade acumulada dos dados em 88,71%. A alocação dos animais no novo sistema e a construção da região de confiança revelou a presença de seis espúrios ao lote homogêneo formado por 109 animais. Conclusão: O critério biométrico proposto mostra-se eficiente, pois considera o animal como um todo, analisando conjuntamente todos os parâmetros mensurados, além de apresentar pequena frequência de descartes