187 resultados para vascular aging
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The effect of the presence of tartrate additive on the chemical stability of a Cu-Sn acid bath was evaluated. It was observed that this additive hinders decomposition of the Cu/Sn deposition bath with storage time, since the decrease in electrochemical efficiency was attenuated. In addition, it was observed that optimal galvanostatic deposition with or without tartrate occurs at approximately 11 mA cm(-2). However, in the presence of tartrate the deposition charge was lower, leading to lower energy consumption. SEM analysis showed that the tartrate added to the plating bath caused a marked change in the morphology of the Cu/Sn films obtained gal vanostatic ally. (C) 2002 Elsevier B.V. B.V. All rights reserved.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Digestion is associated with gastric secretion that leads to an alkalinisation of the blood, termed the alkaline tide. Numerous studies on different reptiles and amphibians show that while plasma bicarbonate concentration ([HCO3-](pl)) increases substantially during digestion, arterial pH (pHa) remains virtually unchanged, due to a concurrent rise in arterial PCO2 (PaCO2) caused by a relative hypoventilation. This has led to the suggestion that postprandial amphibians and reptiles regulate pHa rather than PaCO2.Here we characterize blood gases in the South American rattlesnake (Crotalus durissus) during digestion and following systemic infusions of NaHCO3 and HCl in fasting animals to induce a metabolic alkalosis or acidosis in fasting animals. The magnitude of these acid-base disturbances were similar in magnitude to that mediated by digestion and exercise. Plasma [HCOT] increased from 18.4+/-1.5 to 23.7+/-1.0 mmol L-1 during digestion and was accompanied by a respiratory compensation where PaCO2 increased from 13.0+/-0.7 to 19.1+/-1.4 mm Hg at 24 h. As a result, pHa decreased slightly, but were significantly below fasting levels 36 h into digestion. Infusion of NaHCO3 (7 mmol kg(-1)) resulted in a 10 mmol L-1 increase in plasma [HCO3-] within 1 h and was accompanied by a rapid elevation of pHa (from 7.58+/-0.01 to 7.78+/-0.02). PaCO2, however, did not change following HCO3- infusion, which indicates a lack of respiratory compensation. Following infusion of HCl (4 mmol kg(-1)), plasma pHa decreased by 0.07 units and [HCO3-](pl) was reduced by 4.6 mmol L-1 within the first 3 h. PaCO2, however, was not affected and there was no evidence for respiratory compensation.Our data show that digesting rattlesnakes exhibit respiratory compensations to the alkaline tide, whereas artificially induced metabolic acid-base disturbances of same magnitude remain uncompensated. It seems difficult to envision that the central and peripheral chemoreceptors would experience different stimuli during these conditions. One explanation for the different ventilatory responses could be that digestion induces a more relaxed state with low responsiveness to ventilatory stimuli. (C) 2005 Elsevier B.V. All rights reserved.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Prostate differentiation during embryogenesis and its further homeostatic state maintenance during adult life depend on androgens. Abundant biological data suggest that androgens play an important role in the development of the prostate cancer and other prostatic diseases. The objective of this work was to evaluate the effects of the testosterone supplementation in gerbil (a new experimental model) at different ages. Tissues from experimental animals were studied by histological and histochemistry procedures, androgen receptor immunohistochemistry assay, morphometric-stereological analysis, and transmission electron microscopy (TEM). After the treatment were observed increase of prostate weight and epithelium height in all ages studied. In some adult and aged treated animals, hyperplasic and displasic process were observed, including prostatic intraepithelial neoplasias and adenocarcinomas. Increase of the thickness of the smooth muscle cell (SMC) layer was observed in pubescent and adult animals and TEM revealed apparent SMC hypertrophy. An apparent increase in the frequency of blood vessels distributed by the subepithelial stroma in the treated animals was noticed. Reversion of the natural effects of aging on the prostate was observed in the aged treated animals in some acini of the gland. These data demonstrate that the gerbil prostate is susceptible to androgenic action at the studied ages and it can serve, for example, as experimental model to studies of prostate neoplasic process induction and hormonal therapy in aged animals.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Different from the classic view, the prostate is not a gland exclusive to the male, also being an organ of the female genital system presenting morphofunctional similarity between human and rodent. Thus structural, ultrastructural, morphometric-stereological features of the female prostate (Skene's paraurethral gland) and steroid serological levels were evaluated during young, adult, and senile ages in the Mongolian gerbil. The morphofunctional precocity of the female gland in comparison with the male gland occurring in young gland is probably associated with the female circulating steroid levels. The hormonal imbalance in senesce coincides with its susceptibility to histopathological lesions, such as epithelial hypertrophy, metaplasia, and intraepithelial neoplasia. Differently than that of males, the aging degeneration of the female gland involves the accumulation of lipofuscin granules. However, the alterations in senile prostate did not damage its functionality. These analyses reinforce the use of this experimental model for the comprehension of glandular morphofunctional aspects with special attention to senescence. Thus, the appreciation of this organ becomes relevant to avoid future discomfort to women's health.
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Background Damage to the corneal epithelium causes not only a reaction for its repair but also affects other parts of the cornea as well as different components of the anterior segment of the eye. The purpose of this investigation was to analyze the consequences, following epithelial and limbal damage, to the iris of rabbits (Oryctolagus cuniculus).Methods The corneal epithelium was thoroughly scraped followed by surgical excision of the limbus. Next, (3)H-thymidine ((3)H-TdR) was injected intravitreally both into the right (experimental) and left (control) eyes which had their anterior segments processed for autoradiography at intervals of 2, 7 and 21 days after surgery (three rabbits per interval). The irises were also examined with scanning-electron and confocal microscopy after Evans blue injection.Results There was a high frequency of labeling in the cells of the iris blood vessels in the experimental eye, particularly the endothelial ones. The ratio of labeled cells between experimental and control irises was 40:1, with a population of nuclei increasing by 25% and remaining labeled up to 21 days. There was also an increase in the volume of the iris vasculature as shown by confocal microscopy. The high labeling frequencies of the vascular cells were observed throughout the iris from the ciliary to the pupillary regions.Conclusions The lesions on the corneal epithelium elicit proliferation of the iris vascular cells, mainly its endothelium, as well as an early breakdown of the blood-aqueous barrier. The daughter cells resulting from the damage to the eye surface were detected up to 21 days after a single injection of (3)H-TdR, most likely due to their slow turnover. As a consequence of this proliferation, the vasculature of the iris increased in volume.
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Cachaca was aged for 6 months in small casks of oak and eight different Brazilian woods (amarelo, amendoim, balsamo, jatoba, louro, pau d'arco, pau d'oleo, and pereiro) in order to determine total phenols, UV-visible spectra differences, and sensorial acceptance. Also used were 200-l casks of oak and pereiro for aging cachaca for 4 years to characterize sensorial descriptors and acceptance. The results suggest that amendoim and pereiro followed by jatobaa are good candidates to replace oak in the construction of cachaca aging casks. It was also observed that when using oak casks as a standard the major changes in the sensory properties occurred in the first 21 months of aging. The principal components analysis of UV-visible absorption spectra of the same beverage stored in casks made of different woods allowed identification of the wood in which the beverage had been aged.
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INTRODUÇÃO: Os leiomiomas são neoplasias benignas do músculo liso que ocorrem mais comumente nos tratos geniturinário e gastrintestinal, entretanto são raros na cavidade bucal, na qual provavelmente a maioria desses tumores tem sua origem a partir de músculo liso vascular. OBJETIVOS: Relatar dois casos com história clínica semelhante, confrontando seus aspectos com aqueles encontrados na literatura. RELATO DOS CASOS: Dois casos de mulheres na quinta e sexta décadas de vida apresentando nódulo submucoso em ventre lingual. Após exame microscópico que revelou numerosos vasos sangüíneos entremeados a células fusiformes, com núcleos ovalados ou alongados, e exame imuno-histoquímico com positividade para actina de músculo liso nos dois casos, o diagnóstico final foi leiomioma vascular. CONCLUSÃO: O estudo do leiomioma vascular bucal é de extrema importância devido à raridade e semelhança desse com outras lesões da cavidade bucal. A análise imuno-histoquímica é importante para o diagnóstico final do leiomioma.