Peripheral oxyntomodulin reduces food intake and body weight gain in rats

Oxyntomodulin (OXM) is a circulating gut hormone released post prandially from cells of the gastrointestinal mucosa. Given intracerebroventricularly to rats, it inhibits food intake and promotes weight loss. Here we report that peripheral (ip) administration of OXM dose-dependently inhibited both fast-induced and dark-phase food intake without delaying gastric emptying. Peripheral OXM administration also inhibited fasting plasma ghrelin. In addition, there was a significant increase in c-fos immunoreactivity, a marker of neuronal activation, in the arcuate nucleus (ARC). OXM injected directly into the ARC caused a potent and sustained reduction in refeeding after a fast. The anorectic actions of ip OXM were blocked by prior intra-ARC administration of the glucagon-like peptide-1 (GLP-1) receptor antagonist, exendin(9-39), suggesting that the ARC, lacking a complete blood-brain barrier, could be a potential site of action for circulating OXM. The actions of ip GLP-1, however, were not blocked by prior intra-ARC administration of exendin(9-39), indicating the potential existence of different OXM and GLP-1 pathways. Seven-day ip administration of OXM caused a reduction in the rate of body weight gain and adiposity. Circulating OXM may have a role in the regulation of food intake and body weight.     

Prevalence and predictors of HIV-associated weight loss in the era of highly active antiretroviral therapy

This study was a cross-sectional study of 122 HIV-positive subjects to determine the prevalence and predictors of weight loss in the era of highly active antiretroviral therapy (HAART). Forty per cent reported lipodystrophy, 40% had documented weight loss (mean 6.6 kg). Mean intake 13,400 kJ (118% of estimated requirements calculated using the Harris-Benedict equation). One hundred (82%) were taking antiretroviral therapy. Using forward stepwise logistic regression analysis only viral load (VL) was significantly associated with weight loss when intake, CD4 T-cell count, lipodystrophy, and age were entered into the model with VL (log copies/mL). Every one log increase in HIV VL was associated with an odds of weight loss of 1.58 (P=0.0008). Weight loss is still common in the HAART era. HIV VL was the most significant predictor of weight loss in this sample. Inadequate dietary intake and self-reported lipodystrophy were not related to weight loss in this population.     

A preliminary open label dose comparison using an antioxidant regimen to determine the effect on viral load and oxidative stress in men with HIV/AIDS

OBJECTIVE: To investigate the effect of antioxidant supplementation on viral load and the antioxidant/reactive oxygen species system in people with HIV. DESIGN: Single centre, prospective, dose comparison study. SETTING: Outpatient clinic specializing in HIV care. SUBJECTS: Sixty-six participants were sequentially recruited by advertisement, and 48 subjects completed the study. INTERVENTIONS: A recommended dose antioxidant regimen (5,450 IU vitamin A as beta-carotene, 250 mg vitamin C, 100 IU vitamin E, 100 microg selenium, 50 mg coenzyme Q10) or a high-dose antioxidant regimen (21,800 IU vitamin A as beta-carotene, 1,000 mg vitamin C, 400 IU vitamin E, 200 microg selenium, 200 mg coenzyme Q10) for a 12 week period. RESULTS: Using repeated measures analysis of variance, the changes over treatment time were significant for selenium, glutathione, glutathione peroxidase and lipid peroxides (P < 0.03). Changes in allantoin, uric acid and viral load were not significant (P > 0.05). The main effects for group and the interaction effects were not significant for any of the parameters measured (P > or = 0.05). CONCLUSION: Antioxidant supplementation significantly improved some measures of oxidative defence. There was no benefit in using a high-dose supplement in this study.     

The effect of frequency of feeding on the response by growing pigs to supplements of free lysine

1. Six experiments, involving a total of 320 pigs, were conducted to examine the response of growing pigs to diets supplemented with free lysine when fed either once daily or in six equal portions at intervals of 3 h. The effect of dry or wet feeding on the response to free lysine was examined in Expt nos. 4 and 5. The assumption of linear lysine response over the range of lysine supplementation was examined in Expt no. 6. 2. A significant (P less than 0.01) interaction between lysine supplementation and frequency of feeding occurred for growth rate and food conversion ratio. Growth responses to the supplements of free lysine with once daily feeding were only 67% of that achieved with frequent feeding. 3. Wet feeding had no effect on the growth responses to free lysine supplements. 4. The lysine response was linear over the range of lysine supplementation examined. 5. The implication of these results to the interpretation of experiments examining the lysine requirements of pigs are discussed.     

Effect of heat on the nutritional value of lupin (Lupinus angustifolius)--seed meal for growing pigs

1. Two experiments were conducted to determine the effects of heat on the nutritional value of lupin (Lupinus angustifolius cv. Uniharvest and Unicrop)-seed meal, relative to soya-bean meal, for growing pigs 2. In both experiments, values for carcass gain/d and food conversion ratio (FCR) on a carcass basis of pigs fed on the diets containing lupin-seed meal were inferior (P less than 0.05) to those produced by pigs fed on soya-bean meal. 3. In the first experiment, heating lupin seed at temperatures from 105 to 150 degrees for 15 min resulted in a linear depression in carcass gain/d, a quadratic increase in carcass FCR, a linear decrease in lean in the ham and a linear increase in backfat thickness. In the second experiment, autoclaving lupin seed from 5 to 45 min at 121 degrees resulted in a linear depression in carcass gain/d and a linear increase in carcass FCR. 4. The addition of L-lysine to the diets containing lupin-seed meal verified that lysine was limiting in both experiments. The additions of L-lysine did not overcome the differences in carcass gains/d of pigs fed on lupin-seed meal relative to those fed on diets containing soya-bean meal. 5. It is concluded that the low lysine availability in lupin-seed meal for pigs is not due to the presence of heat-labile anti-nutritional factors in the seed.     

Scaling cardiac structural data by body dimensions: a review of theory, practice, and problems

Robust estimates of the "true" bivariate relationship between body size (X) and heart size (Y) have seldom been determined empirically. The removal of the covariate influence of body size from cardiac dimension variables facilitates both correct inter- or intra-group comparisons, and the construction of reference standards for normality. In the literature to date this "scaling" or normalisation of cardiac dimensions has been performed typically via a per-ratio standards method, (Y/X), with body surface area chosen as the size denominator. This review demonstrates that the per-ratio standards approach may be theoretically, mathematically, and empirically flawed. The most appropriate scaling procedure appears to be a curvilinear, allometric model of the general form Y = aXb. The cardiac dimension variable (Y) may be regressed upon the body size variable (X) to derive a power function ratio (Y/Xb) that is allegedly size-independent. The current consensus is that an estimate of fat-free mass (FFM) provides the most appropriate body size variable. In the scaling literature allometric modelling procedures have generally yielded FFM exponents (b) consistent with the theory of geometric similarity. We suggest that cardiac dimension data should be scaled by appropriate powers of FFM, derived from allometric modelling. However, despite the potential superiority of FFM as a scaling denominator, reference standards for normality based on FFM have not been developed or proposed. Future research should examine the robustness of the FFM-cardiac dimension relationship in large samples.     

Translation and validation of the Chinese versions of the Suicidal Ideation Attributes Scale,Stigma of Suicide Scale,and Literacy of Suicide Scale

This article reports the validation of the Chinese versions of the Suicidal Ideation Attributes Scale (SIDAS), the short form of Stigma of Suicide Scale (SOSS), and the short form of Literacy of Suicide Scale (LOSS) among 57 Chinese and English bilinguals and 224 Chinese university students. All the translated scales showed high correlations with the original versions. The translated SIDAS and refined SOSS demonstrated robust factor structures, good internal consistency, and convergent validity. Chinese students with self-reported depression symptoms tended to have higher glorification of suicide and lower suicide literacy. These brief scales fill an important gap in evaluating suicide outcomes in Chinese-speaking societies.