Initial locomotor sensitivity to cocaine varies widely among inbred mouse strains.

Initial sensitivity to psychostimulants can predict subsequent use and abuse in humans. Acute locomotor activation in response to psychostimulants is commonly used as an animal model of initial drug sensitivity and has been shown to have a substantial genetic component. Identifying the specific genetic differences that lead to phenotypic differences in initial drug sensitivity can advance our understanding of the processes that lead to addiction. Phenotyping inbred mouse strain panels are frequently used as a first step for studying the genetic architecture of complex traits. We assessed locomotor activation following a single, acute 20 mg/kg dose of cocaine (COC) in males from 45 inbred mouse strains and observed significant phenotypic variation across strains indicating a substantial genetic component. We also measured levels of COC, the active metabolite, norcocaine and the major inactive metabolite, benzoylecgonine, in plasma and brain in the same set of inbred strains. Pharmacokinetic (PK) and behavioral data were significantly correlated, but at a level that indicates that PK alone does not account for the behavioral differences observed across strains. Phenotypic data from this reference population of inbred strains can be utilized in studies aimed at examining the role of psychostimulant-induced locomotor activation on drug reward and reinforcement and to test theories about addiction processes. Moreover, these data serve as a starting point for identifying genes that alter sensitivity to the locomotor stimulatory effects of COC.

Using encoding and retrieval strategies to improve 24-hour dietary recalls among older adults.

OBJECTIVE: To examine whether using an encoding strategy and/or providing more support at the time of retrieval improves the accuracy of 24-hour dietary recalls among the elderly. DESIGN: Posttest-only control group design. SETTING: The sample was recruited through advertisements and at senior centers and a low-income apartment building in rural central Pennsylvania. SUBJECTS: Study participants were 21 men and 73 women aged 58 years old and older. Everyone completed the study. INTERVENTION: The treatment group was unobtrusively guided in use of an encoding strategy before consuming the prepared meal. MAIN OUTCOME MEASURES: A 24-hour dietary recall and recognition tests were administered the next day for the foods consumed at the meal and for serving sizes of 5 of the foods. Memory tests were also administered. STATISTICAL ANALYSES PERFORMED: Linear regression was used to examine differences between the treatment and control groups and to identify variables that explained variation in the number of foods correctly recalled or recognized. The Chi 2 test was used to examine correct vs incorrect recall or recognition of the serving sizes of the 5 foods between the groups and to identify explanatory variables for this task. RESULTS: Subjects remembered more foods when they used an encoding strategy and when recognition replaced free recall; they performed best when both strategies were used. Use of this encoding strategy did not improve accurate recall or recognition of serving sizes of 5 foods; however, performances did improve when recognition replaced free recall. CONCLUSIONS: Among older adults, use of an encoding strategy and provision of support at the time of retrieval enhances memory of foods consumed but not of amounts consumed. To strengthen memory of foods consumed, older adults need to perform effortful memory tasks when they are eating.

Use of dietary supplements in the United States, 1988-94.

OBJECTIVES: This report presents estimates of the prevalence of use of dietary supplements among the U.S. population by various demographic and descriptive characteristics, the number of products taken, and types of supplements taken by broad product-type categories. METHODS: The third National Health and Nutrition Examination Survey (NHANES III) is a nationally representative survey of the civilian, noninstitutionalized U.S. population, 2 months of age or over. Participants were asked about their use of vitamin and/or mineral supplements in the past month. Many also reported use of other dietary supplements. RESULTS: Approximately 40 percent of the population took dietary supplements during the month prior to the interview. Females (44 percent) were more likely to take a supplement than males (35 percent). Non-Hispanic white persons (43 percent) were more likely to take supplements than non-Hispanic black persons (30 percent) and Mexican American persons (29 percent). Children 1-5 years of age were major users of supplements. Among adults 20 years of age and older, there was a trend toward increasing use of dietary supplements with age. Higher levels of education, income, and self-reported health status were all positively related to supplement use. Sixty-seven percent of supplement users took only one supplement, with the majority of them taking a combination vitamin/mineral product (46 percent). CONCLUSIONS: A substantial proportion of the U.S. population takes vitamins, minerals, and/or other dietary supplements.

Zinc intake of the U.S. population: findings from the third National Health and Nutrition Examination Survey, 1988-1994.

National survey data for 29,103 examinees in the third National Health and Nutrition Examination Survey were used to estimate mean and percentile distributions of dietary and total zinc intakes based on 24-h dietary recalls and vitamin/supplement use. Mean daily total intakes ranged from 5.5 mg in non-breast-feeding infants to 13 mg in adults and were higher in adolescent and adult males than in females (P <0.01). Mean total zinc intakes (22 mg) were approximately 10 mg higher in pregnant and lactating females than in nonpregnant, nonlactating females of the same age. Mean total zinc intakes were 0. 7 mg higher in adolescents (11.1 mg) and 2.5-3.5 mg higher in adults (13 mg) compared with mean dietary intakes, indicating the average contribution of supplements to total zinc intake. Mean total zinc intakes were significantly higher in non-Hispanic whites than in non-Hispanic blacks (P<0.01) and Mexican Americans (P<0.01) for men and women aged 51-70 y and > or =71 y due to higher zinc supplement use. The prevalence of zinc-containing supplements use ranged from 0. 1% in infants to 20.5% in adults. "Adequate" zinc intake in this survey population was 55.6% based on total intakes of >77% of the 1989 recommended dietary allowance. Young children aged 1-3 y, adolescent females aged 12-19 y and persons aged > or =71 y were at the greatest risk of inadequate zinc intakes.