Prospects for an anti-ghrelin vaccine to treat obesity

In the battle to treat the pandemic of obesity, one therapeutic strategy is to block endogenous signals that stimulate appetite and control body weight. One such molecule is ghrelin, a gut peptide that is the only known orexigenic hormone and is a likely contributor to mealtime hunger. The relative importance of ghrelin in long-term body-weight regulation (and thus its promise as an anti-obesity target) is uncertain, however, because genetic and pharmacologic blockade of ghrelin signaling have yielded variable results to date. Using a novel approach of vaccinating rats against their own ghrelin, Zorilla et al. report that animals with high ghrelin-specific antibody titers displayed restricted body weight, without evidence of non-specific inflammation following the vaccine. These results favor a meaningful role for ghrelin in energy homeostasis, hinting at a possible new anti-obesity approach. More broadly, the work of Zorilla et al. supports the feasibility of vaccinations directed against specific autologous targets--immunopharmacotherapy that could potentially be developed to target a wide array of medical conditions.     

Using brown adipose tissue to treat obesity - the central issue

Current therapeutic strategies are proving inadequate to deal with growing obesity rates because of the inherent resistance of the human body to weight loss. The activation of human brown adipose tissue (BAT) represents an opportunity to increase energy expenditure and weight loss alongside improved lipid and glucose homeostasis. Research into the regulation of BAT has made increasing the thermogenic capacity of an individual to treat metabolic disease a plausible strategy, despite thermogenesis being under tight central nervous system control. Previous therapies targeted at the sympathetic nervous system have had deleterious effects because of a lack of organ specificity, but advances in our understanding of central BAT regulatory systems might open up better strategies to specifically stimulate BAT in obese individuals to aid weight reduction.     

Biomechanics of overground vs. treadmill walking in healthy individuals.

The goal of this study was to compare treadmill walking with overground walking in healthy subjects with no known gait disorders. Nineteen subjects were tested, where each subject walked on a split-belt instrumented treadmill as well as over a smooth, flat surface. Comparisons between walking conditions were made for temporal gait parameters such as step length and cadence, leg kinematics, joint moments and powers, and muscle activity. Overall, very few differences were found in temporal gait parameters or leg kinematics between treadmill and overground walking. Conversely, sagittal plane joint moments were found to be quite different, where during treadmill walking trials, subjects demonstrated less dorsiflexor moments, less knee extensor moments, and greater hip extensor moments. Joint powers in the sagittal plane were found to be similar at the ankle but quite different at the knee and hip joints. Differences in muscle activity were observed between the two walking modalities, particularly in the tibialis anterior throughout stance, and in the hamstrings, vastus medialis and adductor longus during swing. While differences were observed in muscle activation patterns, joint moments and joint powers between the two walking modalities, the overall patterns in these behaviors were quite similar. From a therapeutic perspective, this suggests that training individuals with neurological injuries on a treadmill appears to be justified.     

Eating disorder symptomatology in normal-weight vs. obese individuals with binge eating disorder

Although normal-weight individuals comprise a substantial minority of the binge eating disorder (BED) population, little is known about their clinical presentation. This study sought to investigate the nature and severity of eating disturbances in normal-weight adults with BED. We compared 281 normal-weight (n = 86) and obese (n = 195) treatment-seeking adults with BED (mean age = 31.0; s.d. = 10.8) on a range of current and past eating disorder symptoms using ANOVA and χ(2) analyses. After controlling for age and sex, normal-weight participants reported more frequent use of a range of healthy and unhealthy weight control behaviors compared to their obese peers, including eating fewer meals and snacks per day; exercising and skipping meals more frequently in the past month; and avoiding certain foods for weight control. They also endorsed more frequent attempts at dieting in the past year, and feeling more frequently distressed about their binge eating, at a trend level. There were no group differences in binge eating frequency in the past month, age at onset of binge eating, overvaluation of shape/weight, or likelihood of having used certain weight control behaviors (e.g., vomiting, laxative use) or having sought treatment for an eating disorder in the past. Based on our findings, normal-weight individuals appear to be a behaviorally distinct subset of the BED population with significantly greater usage of both healthy and unhealthy weight control behaviors compared to their obese peers. These results refute the notion that distress and impairment in BED are simply a result of comorbid obesity.     

Antimutagenic effect of eight natural foods on moldy foods in a high liver cancer incidence area.

Ames test procedures were used to test 8 natural food extracts for their antimutagenic activity against the mutagenic activity induced in S. typhimurium strains TA98 and TA100 by aflatoxin B1 (AFB1) or metabolic extracts from A. versicolor or A. ochraceus. The tested substances were extracted repeatedly with acetone. The revertants induced by AFB1, metabolic extracts of A. versicolor or A. ochraceus were significantly decreased when extracts of the 8 natural foods were added to the media. The results showed that these extracts had marked inhibitory effects on the mutagenic activity induced by AFB1 or metabolic extracts of the two molds and also suggested that antimutagenic substances were present in these natural foods. These experiments provide a scientific basis for the study of food substances for the prevention of carcinogenesis. It is considered that these 8 natural food extracts produce marked antimutagenic effects and are practically valuable in the field of chemoprophylaxis of liver cancer in humans.     

Executive functions profile in extreme eating/weight conditions: from anorexia nervosa to obesity

Background

Extreme weight conditions (EWC) groups along a continuum may share some biological risk factors and intermediate neurocognitive phenotypes. A core cognitive trait in EWC appears to be executive dysfunction, with a focus on decision making, response inhibition and cognitive flexibility. Differences between individuals in these areas are likely to contribute to the differences in vulnerability to EWC. The aim of the study was to investigate whether there is a common pattern of executive dysfunction in EWC while comparing anorexia nervosa patients (AN), obese subjects (OB) and healthy eating/weight controls (HC).

Methods

Thirty five AN patients, fifty two OB and one hundred thirty seven HC were compared using the Wisconsin Card Sorting Test (WCST); Stroop Color and Word Test (SCWT); and Iowa Gambling Task (IGT). All participants were female, aged between 18 and 60 years.

Results

There was a significant difference in IGT score (F(1.79); p<.001), with AN and OB groups showing the poorest performance compared to HC. On the WCST, AN and OB made significantly more errors than controls (F(25.73); p<.001), and had significantly fewer correct responses (F(2.71); p<.001). Post hoc analysis revealed that the two clinical groups were not significantly different from each other. Finally, OB showed a significant reduced performance in the inhibition response measured with the Stroop test (F(5.11); p<.001) compared with both AN and HC.

Conclusions

These findings suggest that EWC subjects (namely AN and OB) have similar dysfunctional executive profile that may play a role in the development and maintenance of such disorders.     

含酚废水处理高效菌株的筛选

酚类化合物属于持久性有机污染物,含酚废水在我国水污染控制中被列为需要重点解决的有害废水之一。本文通过对本钢焦化厂含酚分废水处理工艺中曝气池内活性污泥所含未知菌株进行分离纯化,并经过对酚的耐受性实验和降解率实验,得到处理酚的高效菌株。通过对筛选出的菌株进行细胞个体形态和菌群形态特征观察及一系列生理生化实验,确定筛选出来的7株能高效降解盼的菌株为假单胞菌。本文的实验结果将有利于今后对含酚废水的处理。