Weight change and cognitive performance.

OBJECTIVE: To investigate whether under- or overweight and weight change is associated with cognitive performance of elderly citizens. DESIGN: Explorative analysis out of the Basel Study cohort. SUBJECTS: In all, 531 healthy subjects (445 men/86 women) were assessed with the Consortium to Establish a Registry for Alzheimer's Disease-Neuropsychological Assessment Battery (CERAD-NAB) in 2000 (age: 69.4+/-7.8 y) and weight measurements obtained in 1990 (body mass index (BMI): 25.2+/-3.1 kg/m(2)) and in 2000 (BMI: 25.6+/-3.4 kg/m(2)). METHODS: The predictive power of the annual change in BMI with cognitive performance was investigated by a binary logistic regression analysis (backward) using sex, age, BMI 1990, BMI 2000, diastolic blood pressure, diabetes status, and optimal health status as additional predictors. RESULTS: In the last step, the following variables remained in the model: annual change in BMI (quadratic term; P<0.01); ApoE genotype (P<0.05); and optimal health status (P<0.01). CONCLUSION: The association between the extent of weight change and poorer cognitive performance could be either a consequence of cognitive impairment or an early symptom of neurodegenerative decline.

Fruit and vegetable servings in ten SENECA towns and the impact of the midday meal.

OBJECTIVE: Assessing fruit, vegetable and potato servings in relation to meal pattern. DESIGN: Longitudinal study including dietary assessment in 1988/9 and 1993. SETTING: 10 small European towns. SUBJECTS AND METHODS Counting the number of fruit, vegetable and potato servings in dietary records of 1275 men and women born 1913 to 1918. RESULTS: In the northern towns less than 12% of the subjects consumed 5 or more fruit and vegetable servings and up to 84% consumed only 2 or less servings per day. In the southern towns more than 30% consumed 5 or more servings and less than 20% had only 2 or less servings per day. In 9 of 10 towns a cooked meal at midday contained more fruit and vegetable servings than a cooked meal eaten in the evening. The weight of one serving as calculated from the regression line was 137 g for fruit, 145 g for vegetables and 196 g for potatoes. A significant relationship was found between antioxidant status and vegetables with regard to the number of servings but not to the intake in gram. CONCLUSIONS: RESULTS strengthen the hypothesis that a cooked meal at midday mediated a healthier diet than a cooked meal in the evening. Number of fruit and vegetable servings is a more accurate indication of diversity in vegetable consumption than intake in gram.

Vitamin C concentrations in plasma as a function of intake: a meta-analysis.

The purpose of this study was to estimate the intake-plasma relationship for vitamin C by means of a meta-analysis. A MEDLINE search revealed 30 publications matching our inclusion criteria. We completed the set with 5 older papers and with one monograph. The proposed statistical model corrects for inconsistencies with regard to methodological differences between the various studies. Therefore, the contribution of a particular study to the estimation is independent of the number of data points. The estimations were performed for the complete data set as well as for different subgroups: "adult" aged 15-65 years, "elderly" aged 60-96 years, "nonsmokers" and "smokers". The 50th percentile of the plasma concentration for a daily vitamin C intake of 60 mg was 42.4 mumol/L. The corresponding values for the different subgroups were: "adult" 44.1 mumol/L, "elderly" 31.0 mumol/L, "nonsmokers" 42.4 mumol/L, and "smokers" 33.6 mumol/L. Thus, this meta-analysis confirms earlier results that the requirements of vitamin C is higher in "elderly" and "smokers" compared to "adult" and "nonsmokers" and it can be used for the estimation of the vitamin C intake in order to achieve a desired plasma level within a target population. In the general population the assumed optimal plasma concentration of 50 mumol/L, as proposed by a consensus conference, can be achieved by the intake of 100 mg per day, which is the new recommendation of the Austrian, German, and Swiss Nutrition Societies.

Modelling of mortality data from a multi-centre study in Japan by means of Poisson regression with error in variables.

BACKGROUND: Death rates of particular categories in epidemiological studies are often based on a small number of occurrences which can be well described by a Poisson distribution. METHOD: We applied this model for the analysis of a multi-centre study in five Japanese counties where the death rates of stomach cancer (ICD-9 code 151) in four age groups are known. In our example some covariates of the cases (e.g. plasma lycopene levels) are unknown values and are estimated from a randomly chosen collective. Therefore these values are subject to a sampling error. The inclusion of errors in variables (e-i-v) into the statistical model can adequately describe such a situation. The model is estimated in a Bayesian framework by means of resampling techniques. RESULTS: Based on the posterior distribution of the parameters the relative risk of stomach cancer is 0.46 (95% confidence interval: 0.23-0.79) comparing the maximum of the population medians of lycopene with the minimum. The estimated overdispersion is close to zero indicating only minor interference with other possible explanatory variables. In addition, we show that inclusion of e-i-v can give more accurate estimates of the parameters even from small sample sizes. CONCLUSIONS: Appropriate statistical methods allow the accurate estimation of relative risks from small sample sizes and from low number of cases. Lycopene plasma levels are good predictors for stomach cancer.

Vitamin E and vitamin A concentrations in plasma adjusted for cholesterol and triglycerides by multiple regression.

The plasma concentration of vitamins A and E varies with the amount of concurrent lipids and thus requires lipid standardization. The present study compares a new multiple regression-based method for adjusting vitamins A and E concentrations for cholesterol and triglycerides with previous methods (adjustment for cholesterol only, and adjustment for the sum of cholesterol and triglycerides). The results show that the new method can reduce influence of the concurrent lipids.

Chick laminin: isolation by monoclonal antibodies and differential distribution of variants in the embryo.

In order to study the expression and function of laminin variants during chick embryonic development, we have generated monoclonal antibodies against chick heart laminin. One monoclonal antibody (mAb), called 9/F-10, could be used to purify chick laminin to homogeneity. By rotary shadowing, cross-shaped and T-shaped laminin particles as well as aggregates of two laminin molecules crosslinked via their short arms could be observed in this preparation. Purified chick laminin was very potent in mediating neurite growth by chick embryonic neurons. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of reduced chick heart laminin revealed a complex pattern of polypeptides which are immunologically related to several mammalian laminin chains. The two mAbs, 9/F-10 and 3/E-8, recognize two different types of chick laminin subunits. By immunofluorescence, antibody 3/E-8 labels basement membranes, aortic smooth muscle, and mesenchyme of 6-day-old chick embryos. In contrast, staining by mAb 9/F-10 is confined to basement membranes. Therefore, the two antibodies seem to distinguish between two different chick laminin isoforms.

Epithelial synthesis of tenascin at tips of growing bronchi and graded accumulation in basement membrane and mesenchyme.

The extracellular matrix protein, tenascin, has been proposed as mediator in epithelial-mesenchymal interactions because of its characteristic distribution during embryogenesis. Here we compared the accumulation of tenascin and laminin in the early chicken lung bud. Laminin is deposited in the basement membrane, starting at the tips and increasing along the shafts of growing primary and secondary bronchi. In contrast, tenascin accumulation is highest in basement membranes and mesenchyme at sites where new bronchial branches are formed. By in situ hybridization, tenascin mRNA was found to be produced exclusively by the epithelium at sites of active growth of bronchial tubes.

Riboflavin status of adolescent vs elderly Gambian subjects before and during supplementation.

Riboflavin status was measured by activation coefficient of erythrocyte glutathione reductase (EGRAC) in elderly and adolescent rural Gambians whose intakes were low. Fifty-one adolescents and 52 elderly subjects were each subdivided into six supplementation groups to receive 0.25, 0.5, 0.75, 1.0, 1.5, or 2.5 mg riboflavin/d on 5 consecutive days weekly for 5 wk. Before supplementation, EGRAC values were grossly abnormal and differed (p less than 0.005) between the two female groups [elderly subjects, 1.94 +/- 0.33 (means +/- SD); adolescents. 1.72 +/- 0.27] but not between the two male groups. With supplementation greater than 0.25 mg/d the values became nearly equal in the two age groups. Only at total intakes between 1.8 and 2.5 mg riboflavin/d did the subjects attain acceptable status, with a mean EGRAC of 1.3-1.4. Clearly there is a need for further study of the discrepancy between observed index values during supplementation and the accepted ranges of normality at intakes close to the recommended amounts.

Running performance in Gambian children: effects of water-soluble vitamins or iron.

Sixty-nine boys and girls between 10 and 14 years, with evidence of subclinical vitamin deficiencies and poor iron status were enrolled into the study at the beginning of the rainy season. Children were allocated to three treatment groups to receive five times weekly either a placebo, 200 mg ferrous sulphate or 5 mg riboflavin and 150 mg ascorbic acid. Before receiving the supplement, and 9 weeks later, children performed an exercise regimen on a treadmill during which expired air was collected and heart rate measured. There was a general deterioration in the running performance of the children during the study period which was not affected by either the iron or the vitamin supplement.