392 research outputs found

    Low fatness, reduced fat intake and adequate plasmatic concentrations of LDL-cholesterol are associated with high bone mineral density in women: a cross-sectional study with control group

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    <p>Abstract</p> <p>Background</p> <p>Several parameters are associated with high bone mineral density (BMD), such as overweight, black background, intense physical activity (PA), greater calcium intake and some medications. The objectives are to evaluate the prevalence and the main aspects associated with high BMD in healthy women.</p> <p>Methods</p> <p>After reviewing the database of approximately 21,500 BMD scans performed in the metropolitan area of São Paulo, Brazil, from June 2005 to October 2010, high BMD (over 1400 g/cm<sup>2 </sup>at lumbar spine and/or above 1200 g/cm<sup>2 </sup>at femoral neck) was found in 421 exams. Exclusion criteria were age below 30 or above 60 years, black ethnicity, pregnant or obese women, disease and/or medications known to interfere with bone metabolism. A total of 40 women with high BMD were included and matched with 40 healthy women with normal BMD, paired to weight, age, skin color and menopausal status. Medical history, food intake and PA were assessed through validated questionnaires. Body composition was evaluated through a GE-Lunar DPX MD + bone densitometer. Radiography of the thoracic and lumbar spine was carried out to exclude degenerative alterations or fractures. Biochemical parameters included both lipid and hormonal profiles, along with mineral and bone metabolism. Statistical analysis included parametric and nonparametric tests and linear regression models. <it>P </it>< 0.05 was considered significant.</p> <p>Results</p> <p>The mean age was 50.9 (8.3) years. There was no significant difference between groups in relation to PA, smoking, intake of calcium and vitamin D, as well as laboratory tests, except serum C-telopeptide of type I collagen (s-CTX), which was lower in the high BMD group (<it>p </it>= 0.04). In the final model of multivariate regression, a lower fat intake and body fatness as well a better profile of LDL-cholesterol predicted almost 35% of high BMD in women. (adjusted R2 = 0.347; <it>p </it>< 0.001). In addition, greater amounts of lean mass and higher IGF-1 serum concentrations played a protective role, regardless age and weight.</p> <p>Conclusion</p> <p>Our results demonstrate the potential deleterious effect of lipid metabolism-related components, including fat intake and body fatness and worse lipid profile, on bone mass and metabolism in healthy women.</p

    Dietary calcium: strategies to optimize intake

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    Calcium is an essential nutrient required for numerous biological functions. Studies have demonstrated an association between low calcium intake and chronic diseases, such as osteoporosis, colon cancer, hypertension, and obesity. However, most Brazilians do not meet the adequate intake for calcium. This review focuses on the endogenous (age, hormonal state) and exogenous (phytate, oxalate, sodium, bioactive compounds and vitamin D) factors that can influence calcium absorption. The main methods used for evaluating calcium absorption and bioavailability. The potential factors for the low calcium intake: 1) Food habits - substitution of milk for soft drinks, eating away from home and skipping meals specially breakfast; 2) High cost of dairy food. Besides, this article discuss strategies to optimize calcium intake: 1) Increase knowledge of the relationship between calcium and health and the main food sources; 2) Increase availability of calcium-fortified foods; 3) Supplement use for target groups - when and how administrate calcium salts.O cálcio é um nutriente essencial necessário em diversas funções biológicas. Estudos têm demonstrado a associação entre o baixo consumo de cálcio e doenças crônicas, entre elas osteoporose, câncer de colón, hipertensão arterial e obesidade. Entretanto, grande parte da população brasileira apresenta consumo de cálcio abaixo do recomendado. Este artigo objetiva revisar os fatores endógenos (idade e estado hormonal) e exógenos (fitatos, oxalatos, sódio, compostos bioativos e vitamina D) que influenciam a absorção do cálcio, bem como as principais metodologias utilizadas para avaliar a absorção e biodisponibilidade desse nutriente. Discorre-se sobre os possíveis fatores para o baixo consumo de cálcio: 1) Hábito alimentar - substituição de leite por bebidas com baixo teor de cálcio como o refrigerante, refeições realizadas fora de casa e a não realização de refeições como o café da manhã; 2) Alto custo dos alimentos fontes de cálcio. Além disso, este artigo discute as estratégias para otimizar o consumo do cálcio, que incluem: 1) Aumentar o conhecimento sobre a importância do consumo de cálcio para a saúde e as principais fontes alimentares desse nutriente; 2) Aumentar a disponibilidade de alimentos fortificados com cálcio; 3) Uso de suplementos em grupos específicos - quando e como administrar os sais de cálcio.Universidade de São Paulo Faculdade de Saúde Pública Departamento de NutriçãoUniversidade Federal de São Paulo (UNIFESP) EPMUNIFESP, EPMSciEL

    GPU-BASED PARALLEL COMPUTING IN REAL-TIME MODELING OF ATMOSPHERIC TRANSPORT AND DIFFUSION OF RADIOACTIVE MATERIAL

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    Atmospheric radionuclide dispersion systems (ARDS) are essential mechanisms to predict the consequences of unexpected radioactive releases from nuclear power plants. Considering, that during an eventuality of an accident with a radioactive material release, an accurate forecast is vital to guide the evacuation plan of the possible affected areas. However, in order to predict the dispersion of the radioactive material and its impact on the environment, the model must process information about source term (radioactive materials released, activities and location), weather condition (wind, humidity and precipitation) and geographical characteristics (topography). Furthermore, ARDS is basically composed of 4 main modules: Source Term, Wind Field, Plume Dispersion and Doses Calculations. The Wind Field and Plume Dispersion modules are the ones that require a high computational performance to achieve accurate results within an acceptable time. Taking this into account, this work focuses on the development of a GPU-based parallel Plume Dispersion module, focusing on the radionuclide transport and diffusion calculations, which use a given wind field and a released source term as parameters. The program is being developed using the C ++ programming language, allied with CUDA libraries. In comparative case study between a parallel and sequential version of the slower function of the Plume Dispersion module, a speedup of 11.63 times could be observed

    Espécies Sentinelas: Monitoramento Ambiental com Base em Biomarcadores de Efeito Cito- e Genotóxico

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    Human demographic growth has promoted extreme elevation of anthropic impacts and promoting a decline in biodiversity in several ecosystems on Earth. This makes it essential to apply effective monitoring and more effective conservation actions. In recent times, monitoring tends to have a lower operational and financial cost, so that it can be developed for a long time. Effect biomarkers (e.g., comet, micronucleus, and neutral red assays) have been successfully used in flagship species, which have been shown to be an excellent reflection of the quality of an environment. These species, named 'environmental sentinels', show harmful anthropic impacts even in the initial moments, anticipating management actions that avoid persistent (and sometimes irreversible) damage to species, populations and local communities, which would only be verified in the future. Sentinel species need to be resistant enough, resident in the environment under evaluation, have reduced vagility and show interaction with the greatest number of environmental components, whether abiotic or biotic. The works carried out about invertebrate species (e.g., bivalves and crustaceans) and vertebrates (e.g., fish and mammals) have shown the excellence and effectiveness of biomarkers, with evaluations at the cellular and/or molecular level. Present study aims to present the procedures that must be adopted during the assessment of environmental quality through the use of effect biomarkers (geno- and cytotoxicity), from the choice of sentinel species, care in conducting protocols and the effectiveness of these assays in real cases.O crescimento demográfico humano tem promovido extrema elevação dos impactos antrópicos, acarretando declínio da biodiversidade mundial em vários ecossistemas, tornando imprescindível a aplicação de monitoramentos eficazes e ações efetivas de conservação. Atualmente, existe uma tendência de que os monitoramentos sejam de menor custo operacional e financeiro, bem como que possam ser desenvolvidos por longa duração. Os biomarcadores de efeito (p. ex., ensaios cometa, micronúcleo e vermelho neutro), têm sido empregados com sucesso em espécies emblemáticas, que têm se mostrado um ótimo reflexo da qualidade de um ambiente. Tais espécies, nomeadas "sentinelas ambientais", evidenciam impactos antrópicos danosos ainda nos momentos iniciais, antecipando ações de gestão que evitem danos persistentes (às vezes irreversíveis) nas espécies, populações e comunidades locais, que somente seriam constatados futuramente. Espécies sentinelas precisam ser resistentes o suficiente, residentes do ambiente em avaliação, possuir reduzida vagilidade e mostrar interação com o maior número de componentes ambientais, sejam eles abióticos ou bióticos. Os trabalhos desenvolvidos com espécies de invertebrados (p. ex., bivalves e crustáceos) e vertebrados (p. ex., peixes e mamíferos) têm mostrado a excelência e eficácia dos biomarcadores, com avaliações no nível celular e molecular. O presente estudo visa apresentar os procedimentos que devem ser adotados durante a avaliação da qualidade ambiental pelo uso de biomarcadores de efeito (genotoxicidade e citotoxicidade), desde a escolha das espécies sentinelas, os cuidados na condução dos protocolos e a eficácia dos métodos em casos reais

    Characterization Of Chemically Induced Ovarian Carcinomas In An Ethanol-preferring Rat Model: Influence Of Long-term Melatonin Treatment.

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    Ovarian cancer is the fourth most common cause of cancer deaths among women, and chronic alcoholism may exert co-carcinogenic effects. Because melatonin (mel) has oncostatic properties, we aimed to investigate and characterize the chemical induction of ovarian tumors in a model of ethanol-preferring rats and to verify the influence of mel treatment on the overall features of these tumors. After rats were selected to receive ethanol (EtOH), they were surgically injected with 100 µg of 7,12-dimethyl-benz[a]anthracene (DMBA) plus sesame oil directly under the left ovarian bursa. At 260 days old, half of the animals received i.p. injections of 200 µg mel/100 g b.w. for 60 days. Four experimental groups were established: Group C, rats bearing ovarian carcinomas (OC); Group C+EtOH, rats voluntarily consuming 10% (v/v) EtOH and bearing OC; Group C+M, rats bearing OC and receiving mel; and Group C+EtOH+M, rats with OC consuming EtOH and receiving mel. Estrous cycle and nutritional parameters were evaluated, and anatomopathological analyses of the ovarian tumors were conducted. The incidence of ovarian tumors was higher in EtOH drinking animals 120 days post-DMBA administration, and mel efficiently reduced the prevalence of some aggressive tumors. Although mel promoted high EtOH consumption, it was effective in synchronizing the estrous cycle and reducing ovarian tumor mass by 20%. While rats in the C group displayed cysts containing serous fluid, C+EtOH rats showed solid tumor masses. After mel treatment, the ovaries of these rats presented as soft and mobile tissues. EtOH consumption increased the incidence of serous papillary carcinomas and sarcomas but not clear cell carcinomas. In contrast, mel reduced the incidence of sarcomas, endometrioid carcinomas and cystic teratomas. Combination of DMBA with EtOH intake potentiated the incidence of OC with malignant histologic subtypes. We concluded that mel reduces ovarian masses and the incidence of adenocarcinomas in ethanol-deprived rats.8e8167

    Slipper lobsters (Scyllaridae) off the southeastern coast of Brazil: relative growth, population structure, and reproductive biology

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    The hooded slipper lobster (Scyllarides deceptor) and Brazilian\ud slipper lobster (S. brasiliensis) are commonly caught by fishing fleets (with double-trawling and longline pots and traps) off the southeastern coast of Brazil. Their reproductive biology is poorly known and research on these 2 species would benefit efforts in resource management. This study characterized the population structure of these exploited species on the basis of sampling from May 2006 to April 2007 off the coast of Santos, Brazil. Data for the absolute fecundity, size at maturity in females, reproductive period, and morphometric relationships of the dominant species, the hooded slipper lobster, are presented. Significant differential growth was not observed between juveniles and adults of each sex, although there was a small investment of energy in the width and length of the abdomen in females and in the carapace length for males in larger animals (>25 cm in total length [TL]). Ovigerous females were caught more frequently in shallow waters in August–September than in January–February, indicating a possible migration to spawn. Fecundity ranged from 55,800 to 184,200 eggs (mean fecundity: 115,000 [standard deviation 43,938] eggs). The spawning period occurred twice a year, with a higher relative frequency between July and October, and the length at 50% maturity for females was ~25 cm TL; both these findings should be considered by resource managers. Proper management of catches of slipper lobsters is important because of the high economic value of this fishery
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