Resveratrol inhibits gentamicin-induced mesangial cell contraction.

Gentamicin is an aminoglycoside antibiotic that is very effective in treating different gram negative infections, however, one of its main side effects is nephrotoxicity. Gentamicin-induced decreases in glomerular filtration rate could be mediated by mesangial cell contraction. Resveratrol, a natural hydroxystilbene, has been identified to be a potent antioxidant with many biological activities including protection against kidney diseases. As we have previously demonstrated that gentamicin induced a reduction of planar surface area of cultured rat mesangial cells, and that resveratrol has a protective effect on gentamicin-induced nephrotoxicity in vivo, the aim of this study was to investigate the effect of resveratrol on gentamicin-induced mesangial cell contraction. This study demonstrates that the contractile effect of gentamicin on mesangial cells can be prevented by incubation with resveratrol at an optimal dose of 10 microM, as it blunted the gentamicin-induced reduction in planar cell surface area and the number of contracted cells. Besides, the preincubation with 10(-5)M diphenylene iodinium (DPI), an inhibitor of the NADP(H) oxidase, also blunted gentamicin-induced cell contraction. This preventive effect was higher when cells were incubated with both substances together. These results strongly suggest that the protective effect resveratrol against gentamicin-induced reduction in renal function in vivo could be mediated by inhibiting gentamicin-induced mesangial cells contraction.

Gender Differences in Risk Factors for Stice's Bulimia in a Non-Clinical Sample.

Some females are at an increased risk of developing bulimia. However, etiological factors and their interplay remain controversial. The present study analyzed Sticefe Model for eating disorders in a non-clinical population by examining gender differences with respect to the following risk factors: body mass index (BMI), body dissatisfaction, perceived social pressure to be thin, body-thin internalization, and dieting behavior. A sample of 162 American college students (64 males and 91 females) was surveyed, and validated scales were used. The Sticey model was tested using Structural Equation Modeling. Our results supported Stice r Dual Pathway Model of bulimic pathology for females but not for males. Females reported significantly higher body dissatisfaction, perceived pressure to be thin and weight-loss oriented behaviors than males (p .05), a key predictor of body dissatisfaction (r = .33; p .05) although their BMI was significantly lower than males (d = 0,51). The results of this study fail to support the role of BMI as a predictor of dietary restraint in females, the main risk factor of eating disorders. Males may abstain from dietary restraint to gain muscular volume and in turn increase their BMI. Implications are discussed.

Experimental evidence for improved neuroimaging interpretation using three-dimensional graphic models.

Three-dimensional (3D) or volumetric visualization is a useful resource for learning about the anatomy of the human brain. However, the effectiveness of 3D spatial visualization has not yet been assessed systematically. This report analyzes whether 3D volumetric visualization helps learners to identify and locate subcortical structures more precisely than classical cross-sectional images based on a two dimensional (2D) approach. Eighty participants were assigned to each experimental condition: 2D cross-sectional visualization vs. 3D volumetric visualization. Both groups were matched for age, gender, visual-spatial ability, and previous knowledge of neuroanatomy. Accuracy in identifying brain structures, execution time, and level of confidence in the response were taken as outcome measures. Moreover, interactive effects between the experimental conditions (2D vs. 3D) and factors such as level of competence (novice vs. expert), image modality (morphological and functional), and difficulty of the structures were analyzed. The percentage of correct answers (hit rate) and level of confidence in responses were significantly higher in the 3D visualization condition than in the 2D. In addition, the response time was significantly lower for the 3D visualization condition in comparison with the 2D. The interaction between the experimental condition (2D vs. 3D) and difficulty was significant, and the 3D condition facilitated the location of difficult images more than the 2D condition. 3D volumetric visualization helps to identify brain structures such as the hippocampus and amygdala, more accurately and rapidly than conventional 2D visualization. This paper discusses the implications of these results with regards to the learning process involved in neuroimaging interpretation.