978 resultados para cardiovascular development
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This article reviews the progress of a personal endeavour to develop chromatography as a quantitative procedure for the determination of reaction stoichiometries and equilibrium constants governing protein interactions. As well as affording insight into an aspect of chromatography with which many protein chemists are unfamiliar, it shows the way in which minor adaptations of conventional chromatographic practices have rendered the technique one of the most powerful methods available for the characterization of interactions. That pathway towards quantification is followed from the introduction of frontal gel filtration for the study of protein self-association to the characterization of ligand binding by the biosensor variant of quantitative affinity chromatography.
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Venomous animals have evolved a vast array of peptide toxins for prey capture and defence. These peptides are directed against a wide variety of pharmacological targets, making them an invaluable source of ligands for studying the properties of these targets in different experimental paradigms. A number of these peptides have been used in vivo for proof-of-concept studies, with several having undergone preclinical or clinical development for the treatment of pain, diabetes, multiple sclerosis and cardiovascular diseases. Here we survey the pharmacology of venom peptides and assess their therapeutic prospects.
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Two methods were compared for determining the concentration of penetrative biomass during growth of Rhizopus oligosporus on an artificial solid substrate consisting of an inert gel and starch as the sole source of carbon and energy. The first method was based on the use of a hand microtome to make sections of approximately 0.2- to 0.4-mm thickness parallel to the substrate surface and the determination of the glucosamine content in each slice. Use of glucosamine measurements to estimate biomass concentrations was shown to be problematic due to the large variations in glucosamine content with mycelial age. The second method was a novel method based on the use of confocal scanning laser microscopy to estimate the fractional volume occupied by the biomass. Although it is not simple to translate fractional volumes into dry weights of hyphae due to the lack of experimentally determined conversion factors, measurement of the fractional volumes in themselves is useful for characterizing fungal penetration into the substrate. Growth of penetrative biomass in the artificial model substrate showed two forms of growth with an indistinct mass in the region close to the substrate surface and a few hyphae penetrating perpendicularly to the surface in regions further away from the substrate surface. The biomass profiles against depth obtained from the confocal microscopy showed two linear regions on log-linear plots, which are possibly related to different oxygen availability at different depths within the substrate. Confocal microscopy has the potential to be a powerful tool in the investigation of fungal growth mechanisms in solid-state fermentation. (C) 2003 Wiley Periodicals, Inc.
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Lead (Pb2+) poisoning causes hypertension, but little is known regarding its acute effects on cardiac contractility. To evaluate these effects, force was measured in right ventricular strips that were contracting isometrically in 45 male Wistar rats (250-300 g) before and after the addition of increasing concentrations of lead acetate (3, 7, 10, 30, 70, 100, and 300 µM) to the bath. Changes in rate of stimulation (0.1-1.5 Hz), relative potentiation after pauses of 15, 30, and 60 s, effect of Ca2+ concentration (0.62, 1.25, and 2.5 mM), and the effect of isoproterenol (20 ng/mL) were determined before and after the addition of 100 µM Pb2+. Effects on contractile proteins were evaluated after caffeine treatment using tetanic stimulation (10 Hz) and measuring the activity of the myosin ATPase. Pb2+ produced concentration-dependent force reduction, significant at concentrations greater than 30 µM. The force developed in response to increasing rates of stimulation became smaller at 0.5 and 0.8 Hz. Relative potentiation increased after 100 µM Pb2+ treatment. Extracellular Ca2+ increment and isoproterenol administration increased force development but after 100 µM Pb2+ treatment the force was significantly reduced suggesting an effect of the metal on the sarcolemmal Ca2+ influx. Concentration of 100 µM Pb2+ also reduced the peak and plateau force of tetanic contractions and reduced the activity of the myosin ATPase. Results showed that acute Pb2+ administration, although not affecting the sarcoplasmic reticulum activity, produces a concentration-dependent negative inotropic effect and reduces myosin ATPase activity. Results suggest that acute lead administration reduced myocardial contractility by reducing sarcolemmal calcium influx and the myosin ATPase activity. These results also suggest that lead exposure is hazardous and has toxicological consequences affecting cardiac muscle.
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Borderline hypertension (BH) has been associated with an exaggerated blood pressure (BP) response during laboratory stressors. However, the incidence of target organ damage in this condition and its relation to BP hyperreactivity is an unsettled issue. Thus, we assessed the Doppler echocardiographic profile of a group of BH men (N = 36) according to office BP measurements with exaggerated BP in the cycloergometric test. A group of normotensive men (NT, N = 36) with a normal BP response during the cycloergometric test was used as control. To assess vascular function and reactivity, all subjects were submitted to the cold pressor test. Before Doppler echocardiography, the BP profile of all subjects was evaluated by 24-h ambulatory BP monitoring. All subjects from the NT group presented normal monitored levels of BP. In contrast, 19 subjects from the original BH group presented normal monitored BP levels and 17 presented elevated monitored BP levels. In the NT group all Doppler echocardiographic indexes were normal. All subjects from the original BH group presented normal left ventricular mass and geometrical pattern. However, in the subjects with elevated monitored BP levels, fractional shortening was greater, isovolumetric relaxation time longer, and early to late flow velocity ratio was reduced in relation to subjects from the original BH group with normal monitored BP levels (P<0.05). These subjects also presented an exaggerated BP response during the cold pressor test. These results support the notion of an integrated pattern of cardiac and vascular adaptation during the development of hypertension.
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As doenças cardiovasculares são as principais causas de morte no mundo e muitos constituem os fatores de risco para essas doenças. Objetiva-se investigar o risco cardiovascular para evento coronariano agudo de acordo com o escore de Framingham em população adulta do município de Anchieta-ES. Estudo transversal com dados da linha de base do estudo Carmen Anchieta, iniciado em 2010. A amostra foi sistemática e estratificada por micro área de abrangência das Unidades de Saúde da Família, sexo e idade e 539 pessoas foram selecionadas para este estudo por terem os dados completos. Os dados foram coletados mediante entrevista no domicílio, exames laboratoriais de sangue, verificação da pressão arterial e antropometria nas Unidades de Saúde. As variáveis de exposição constituem escolaridade, raça-cor, renda familiar, residência em espaço urbano ou rural, estado civil, consumo de álcool, atividade física, índice de massa corpórea e autoavaliação de saúde. Para a classificação do risco cardiovascular utilizou-se o escore de Framingham. Foi realizada análise bivariada e regressão logística multinomial para testar a hipótese de associação entre as variáveis e o risco cardiovascular mediante o cálculo da razão de chances (RC) e intervalo de confiança de 95%. O nível de significância foi p < 0,05. Os resultados mostraram predominância de pessoas nas faixas etárias entre 25 a 54 anos, casadas, pardas, ensino fundamental incompleto, baixa renda, insuficientemente ativas, com sobrepeso e obesidade em mais da metade da amostra, 38,6% ingeriam bebida alcoólica e 55,7% relaram saúde muito boa ou boa. O risco cardiovascular foi baixo em 74%, intermediário em 11,3% e elevado em 14,7%. Estiveram associados ao risco cardiovascular intermediário ser analfabeto 8,89 (3,193-24,756), ter ensino fundamental incompleto 3,17 (1,450-6,964) e ser viúvo/ separado 2,55 (1,165-5,583) e associados ao risco cardiovascular elevado ser analfabeto 11,34 (4,281-30,049), ensino fundamental incompleto 2,95 (1,362-6,407) e autoavaliação da saúde muito ruim/ruim 2,98 (1,072-8,307) e regular 2,25 (1,294-3,925). Ser solteiro constituiu fator de proteção 0,40 (0,183-0,902).
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O NEPAD - New Partnership for African Development - tem seus primórdios em 1996, proposto pelo atual presidente da África do Sul, Thabo Mbeki e outros líderes africanos, para erradicar a marginalização e o subdesenvolvimento africanos e promover o crescimento econômico, através da integração continental. Seus objetivos, inseridos no contexto da globalização e do African Renaissance, incorpora valores da luta antiapartheid sul-africana, restauração da auto-estima e resgate de valores pré-coloniais. O que o difere de outros planos que não deram certo na África é o vínculo inseparável entre democracia, direitos humanos, paz, governabilidade e o desenvolvimento econômico, as responsabilidades assumidas pelos participantes e a propriedade africana do plano.
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The expectation that technological returns from defense expenditure through acquisition, international cooperation and domestic research would further national development underappreciates the different technological dynamic of the armed services. This paper outlines the technological dynamic the stems from fighting in the air, at sea and on land, exemplifying consequences for the case of acquisition.
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This paper analyzes People's Republic of China (PRC) economic and political ascendance in the 21st century focusing on the evolution of the sui generis economic development model and its significances of the evolution of relationship between China and the developing countries in the peripheral "Global South." The objective of this article is to analyze the relationship between China and the Global South (Africa and South America) in the 21st century, characterized as a new Center-periphery global network power based on trade and investment that we call as "Asian Consensus."
Chinese energy policy progress and challenges in the transition to low carbon development, 2006-2013
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If the world is not to jeopardize the chances for human life on Earth, climate change must be mitigated; therefore, achieving low carbon development is crucial. China is the world's greatest GHG emitter, energy producer and energy consumer; investigating its energy-climate policy developments and international positions are of utmost importance to understand and tackle current stumbling blocks of the global energy and climate governance.
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Abstract The European Union (EU) is one of the world´s leading donors in official development assistance (ODA) to give a strong weight in the relationship with recipient partner countries, in particular with those that are more dependent on it. Besides the material weight of its funding, the EU has retained historical ties and influence in diplomatic, political and economic terms in many of its ODA recipient partner countries (particular in Sub-Saharan Africa). Since the 2000s, the EU development policy has not only undergone major structural changes in its institutional framework but also has started to face a new international aid scenario. This paper explores why a normative-based EU development policy is being challenged by reformed EU institutions and a new global order, and how the EU is attempting to respond to this context in face of the deepest recession since the end of the Second World War.
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The success of the digital game industry is spawning several undergraduate degrees aiming at the training of digital game developers. Building adequate new courses curricula is not a trivial task and demands a profound analysis of the scientific areas to introduce as well as the dependencies throughout the entire degree. Another important aspect of every academic educational plan are the satellite projects that promote entrepreneurship and provide practical professional experiences to students. This paper presents the main guidelines adopted in the creation of the first digital game development undergraduate degree created in Portugal.