Food restriction and refeeding induces changes in lipid pathways and fat deposition in the adipose and hepatic tissues in rats with diet-induced obesity.

The aim of this study was to determine the effects of successive cycles of a moderately restrictive diet and refeeding with a high-fat diet on the metabolism of the adipose and hepatic tissues of obese rats. Rats were assigned to the following groups: a chow diet; a high-fat diet; a moderate caloric restriction; or a moderate caloric restriction plus refeeding. Some animals in each group were given [1-(14)C]triolein intragastrically, while others received an intraperitoneal injection of 3 mCi (3)H(2)O. All animals were killed by decapitation. The retroperitoneal, visceral epididymal and omental white adipose tissues, brown adipose tissue, liver and blood were immediately removed. The lipid uptake from the diet, in vivo rate of lipogenesis, percentage of fat, lipid profile and leptin concentration were analysed. The high-fat diet promoted an increase in fatty liver (P ≤ 0.05), adiposity mass (P ≤ 0.05) and the plasma concentration of leptin (P ≤ 0.05) and a decreased lipid uptake in white adipose tissue depots (P ≤ 0.05) in relation to the chow diet. The moderate caloric restriction did not reverse the changes promoted by the high-fat diet but induced a small decrease in adiposity, which was reversed after refeeding, and the animals maintained a dyslipidaemic profile and high fat deposition in the liver. We can conclude that the high-fat diet and subsequent moderate caloric restriction plus refeeding increased the risks of developing visceral obesity, dyslipidaemia and non-alcoholic fatty liver disease, which suggests that this type of experimental protocol can be used to study mechanisms related to the metabolic syndrome.

Tendências em biomecânica ortopédica aplicadas à reabilitaçäo / Trends in orthopedic biomechanics applied to rehabilitation

Conceitos de Biomecânica são constantemente utilizados nas mais diversas áreas. Tais conceitos são entretanto primordiais na área de Engenharia de Reabilitação. Este artigo pretende divulgar alguns estudos realizados e em andamento nas áreas de biomecânica e bioengenharia com o intuito de desenvolver novas técnicas para reabilitação de pacientes com algum tipo de deficiência motora. Estas deficiências podem ser de âmbito neurológico ou músculo-esquelético. Dentre as deficiências causadas por problemas neurológicos, pode-se mencionar os casos oriundos de lesões medulares, como a paraplégica e a tetraplégica, e os causados por lesões crânio-encefálicas. No campo das deficiências músculo-esqueléticas incluem-se amputações de membros inferiores ou superiores, doenças congênitas, e algumas doenças degenerativas, como a osteoporose.