Time of day type of food--relation to mood and hunger during 24 hours of constant conditions.

A six-day high-carbohydrate meal (HC; 65 E% (energy percent) carbohydrates, 20 E% fat and 15 E% protein) and a six-day high-fat meal (HF; 40 E% carbohydrates, 45 E% fat and 15 E% protein) were given to seven healthy subjects in a crossover design. On the last day subjects were kept awake for 24 hours in a metabolic laboratory while substrate utilisation and energy expenditure were measured by indirect calorimetry. The subjects were given isocaloric meals every four hours. Results showed that hunger decreased at night (F = 4.2, p < 0.05) and linearly increased after meal intake. Macronutrient composition (fat/carbohydrates) seemed to be of less importance for hunger. Hunger and thirst were found to be strongly associated with gastrointestinal substances, for hunger the strongest being a negative correlation with triacylglycerol (partial correlation = -0.39). It is suggested that it might not be necessary for shift workers to eat full portions at night but that satiation will occur with less food. Possibly lack of adjustment of nocturnal food intake might be one reason why overweight is common in shift work populations.

The influence of physical activity on BMR.

In addition to factors such as fat free mass, hormonal status, genetics and energy balance, previous physical activity has been shown to influence energy turnover during resting (RMR = resting metabolic rate) or basal conditions (BMR = basal metabolic rate). This article presents data on BMR from elite endurance athletes (4 female and 4 male), at least 39 h after their last training session, in comparison with sedentary nonathletic controls matched for sex and fat free mass (FFM). Comparisons with theoretical calculations of BMR were also made. The athletes were shown to have a significantly higher BMR than was expected from calculations based on body mass (16%, P < 0.05) or body composition (12%, P < 0.05). There were no corresponding differences found in the nonathletic control group. The athletes had a 13% higher (P < 0.001) BMR than controls if related to FFM and 16% (P = 0.001) if related to both FFM and fat mass (FM). The athletes were also found to have 10% lower R-values (P < 0.01) indicating higher fat oxidation. The conformity of these findings with the present literature and the possible mechanisms behind them as well as its influence on theoretical calculations of energy turnover (ET) based on activity factors expressed as multiples of RMR are further discussed.

A pocket of controlled malaria in a holoendemic region of West Africa.

Yekepa, a mining town in northern Liberia, has been built entirely since 1960 and now has a population of 16 000 inhabitants including 1500 expatriates. Although situated in a holoendemic region with constant human movements in and out of the town, the mining company has succeeded in controlling malaria in Yekepa. Furthermore, there is a constant threat of the vector in the close surroundings to the town. Control is maintained by regular residual insecticide sprayings with DDT, regular larviciding with fuel oil and fortnightly issue of amodiaquine chemoprophylactic to all workers. A Malariometric survey showed that the spleen and parasite rates were 11% and 13% respectively in the controlled areas and 95% and 67% respectively in surrounding regions not subjected to control measures. The dominant malaria parasite in the area was Plasmodium falciparum. No adult vectors were found in the town. In the surrounding villages the average room density of adult vectors was 3.8 and the sporozoite rate in a village very close to the town was 9.2%. The dominant vector of the area was Anopheles gambiae with A. Funestusalso being present. The annual per capita cost, including all control activities, is about 4--5 US dollars.

Quantification of cell fusion by twenty-one strains of Newcastle disease virus using flow microfluorometry.

The cell-fusing ability of Newcastle disease virus (NDV) was quantified using flow microfluorometry (FMF). The rate of polykaryocyte formation, fusion dependence on multiplicity of infection, and cell fusion differences for 21 NDV strains were measured using this technique. No correlation was found between the virulence of a virus strain and its cell fusion index calculated from the FMF data.

Flow microfluorometric quantitation of the blastogenic response of lymphocytes.

A method for quantitating the specific stimulation of peripheral lymphocytes has been developed using the techniques of flow microfluorometry. Peripheral bovine lymphocytes were collected and specifically stained for deoxyribonucleic acid (DNA) content using a low-salt propidium iodide procedure. Flow microfluorometry was used to determine, on the basis of DNA content, the percentage of cells in a population that was stimulated. Extremely uniform staining of the lymphocytes (coefficient of variation of less than 2%) provides a high resolution between proliferating and nonproliferating cells. The method provides a rapid, highly repoducible technique for determing the fraction of lymphocytes stimulated in response to tuberculin antigens based on an increase in cellular DNA content. Specific and nonspecific stimulation by a defined antigen can be measured and resolved.