Bioavailability of cyanamide in fasted and unfasted rats

The pharmacokinetics of cyanamide after 35 mg kg-1 intravenous and oral administration to fasted and unfasted rats have been investigated. The plasma level are fitted well by a two-compartment open model. The half-life (t 1/2 beta) of cyanamide in the rat was 1 hour and the plasma clearance (C1p) was 0.02 (1 kg-1) min-1. Food does not appear to modify the absolute bioavailability of cyanamide (F = 93.3 per cent fasted, F = 85.5 per cent unfasted), although it does retard drug absorption.     

Serotonin,memory, and the aging brain

Six rhesus monkeys self-administered orally-delivered phencyclidine (PCP) and water under concurrent fixed-ratio (FR) 8 schedules. Liquids were available during three 6.5-h periods daily preceded by 1-h components when food was available under an FR 64 (lever press) schedule. After 10 days of stable behavior, water was substituted for PCP for 8 days. PCP was subsequently reinstated, and this PCP withdrawal sequence was repeated using different food FR values (64, 128, 256, 512 and 1024). Each time the food FR was changed behavior was allowed to stabilize for at least 10 days. Under all FR values food-maintained responding decreased markedly during PCP withdrawal, with a gradual recovery over the next 8 days. As the FR value increased from 64 to 1024 there was a parallel shift downward in food-maintained performance. When PCP was reinstated, food-reinforced responding generally returned to baseline rates during the first few days. In a second experiment monkeys were tested for PCP withdrawal effects under relatively food deprived or food satiated conditions under both an FR 512 and 1024 schedule of food delivery. The results showed that the decrease in food-maintained responding during withdrawal was inversely related to the total amount of food consumed during the control period. The results of these experiments indicate that manipulation of both the response requirements for food (FR) and the total amount of food available (food deprivation/satiation) alters the magnitude of response disruptions during PCP withdrawal.     

McCance & Widdowson's Tables of Food Composition: origins and clarification of the Fifth edition

The evolution of the McCance and Widdowson's Tables of Food Composition is briefly described and some confusions that exist over the Fifth edition are clarified.     

Effects of social modeling on young women's nutrient-dense food intake

We examined whether a same-sex peer's vegetable consumption would predict the number of vegetable pieces eaten by the participant. A total of 116 Dutch women (M age = 20.28; M BMI = 21.68) participated. Their nutrient-dense food intake was measured during a 15-min break between two tasks, consisting of rating television advertisements. Participants consumed more vegetables when exposed to a peer eating a large number of vegetables than when exposed to a peer eating a small number or nothing. These findings suggest that social modeling processes may be relevant to interventions aimed at encouraging young women's nutrient-dense food intake.     

我国的食品卫生监督事业与食品卫生学

作者论述了中国食品卫生监督事业的发展。食品卫生法颁发以前和以后,可分为二个时期,食品卫生法前为结合群众运动的联合行政管理,施行后,开始转入法制管理。食品卫生法的完善促进了一系列标准、法规的制订,本法的实施如促进了各种食品卫生监督机构统一于一个体系。法的突施,混沌不分的行政管理与主管分开了,分清群众运动与依法行政,联合行政管理也为依法行政所取代。食品卫生法的实施也促进了食品卫生科学的发展,使卫生法学、卫生经济学、卫生社会学成为食品卫生学的分枝,食品卫生学发展中,软科学得到了承认。但是食品卫生学发展中也有几个重要问题有待解决,一是软科学有待提高水平,一是要防止教学、科研与卫生监督工作分道扬镖。不论科研机构、大学的工作人员,还是食品卫生监督机构的工作人员,应该都追求同一个目标,共同努力改造食品卫生事业和食品卫生学。特别应该防止为谋取经济实惠之争,搅乱了理论上的规律性。     

Voluntary ethanol consumption in the absence of hunger and thirst drives

Voluntary ethanol consumption in Wistar rats was examined in a choice situation between water and ethanol. In each session continuing over 5 days, ethanol at five different concentrations from 2.5 to 45% (v/v) and water were given as reinforcers for FR-30 lever-press responses during 12-h light and 12-h dark periods with food available. The results indicated that rats preferred 2.5–5% ethanol to water, but water to 30 or 45% ethanol. Daily net ethanol consumption per kg body weight increased monotonically as a function of its concentration and reached a mean value of 9.08 g/kg at 45%. Rats drank most of the ethanol and water during the dark period, despite the large amount of ethanol intake occurring at that time.