World Kidney Day 2011:Protect Your Kidneys,Save Your Heart

Introduction to World Kidney Day2011 March10,2011will mark the celebration of the6th World Kidney Day(WKD),an annual event jointly sponsored by the International Society of Nephrology and the International Federation of Kidney Foundations. Since its inception in2006,WKD has grown dramatically to become the most widely celebrated event associated with kidney disease in the world and the most successful effort to raise awareness among both the     

Obesity,Smoking, and Frontal Brain Dysfunction

Obesity, smoking, and conduct problems have all been associated with decrements in brain function. However, their additive and interactive effects have rarely been examined. To address the deficiency, we studied P300a and P300b electroencephalographic potentials in 218 women grouped by the presence versus absence of: (1) a BMI ≥ 30 kg/m²; (2) recent smoking; and (3) ≥ 2 childhood conduct problems. Analyses revealed smaller P300a and P300b amplitudes over the posterior scalp among recent smokers versus nonsmokers. No corresponding group differences were found in P300 latencies or frontal scalp amplitudes. The most interesting analysis result was an interaction between conduct problems and obesity limited to the frontally generated P300a component: its latency was significantly greater in women with both attributes than in those with either or neither attribute. An exploratory ANOVA, substituting the genotype of a GABRA2 SNP for conduct problems, also demonstrated an interaction with obesity affecting P300a latency. It is hypothesized that conduct problems, and a conduct‐problem‐associated GABRA2 genotype, decrease the age‐of‐onset and/or increase the lifetime duration of obesity. As a result, they may potentiate the adverse effects of obesity on frontal white matter and thereby increase P300a latency. Smoking may affect brain function by a different mechanism to reduce posterior scalp P300a and P300b amplitudes while preserving frontal scalp P300a latency and amplitude. (Am J Addict 2010;00:1–10)     

Brain plasticity, sleep and aging

The link between sleep and aging is a hot topic of research. On the one hand, much attention has been paid to epidemiological studies showing that both short sleep and long sleep in humans are associated with reduced longevity. I will briefly review this literature and discuss recent experiments in the fruit fly Drosophila melanogaster that may contribute to understanding this complicated association. On the other hand, other experiments have focused on age-related sleep changes. Sleep quantity and quality tend to decrease with age, but the underlying mechanisms remain unclear. In young subjects, converging evidence from human and animal studies shows that the need for sleep is strongly modulated by the amount of brain plasticity during prior wake. In short, the more we learn and adapt our brain to an ever-changing environment, the more we need to sleep. If so, poor sleep in the elderly could be caused by a chronic decrease in sleep need due to reduced opportunity to learn and be exposed to novel experiences, rather than, or in addition to, an intrinsic problem in the neural circuits responsible for sleep regulation. This distinction has obvious practical implications. However, very little research has been done on this topic.