Thyroxine-binding prealbumin, overnutrition and apolipoprotein A1.

Thyroxine-binding prealbumin (TBPA) seems to be more useful than other biochemical markers for the detection of subclinical protein-energy malnutrition. Accordingly, one can question whether its sensitivity to nutritional supply could be used in healthy populations for the discrimination of groups with low or high energy intakes; if such were the case, could TBPA serve as an index of overnutrition? In order to answer these questions, we measured TBPA circulating levels in three groups of healthy French subjects from a working population, with relatively low, medium or high levels of energy intake. We also observed the correlations of this protein with nutrient intakes and with some biological parameters related to the general nutritional status of the subjects. The observed figures did not support the hypothesis that TBPA could be used to discriminate healthy subjects with relatively low or high energy intake nor as an index of overnutrition. This study disclosed a positive relation of TBPA with alcohol consumption and related parameters such as body mass index or gamma-glutamyl transferase as well as a negative one with alpha 2-globulin and gamma-globulin. Other investigators have found similar results in chronic alcoholics, surgical patients, or patients suffering from severe illnesses such as cancer. Here, the study population consisted of adult men, neither undernourished nor suffering from any severe pathology and who could not be considered excessive drinkers. Positive relations were also observed between TBPA and apolipoprotein A1 and HDL cholesterol levels, which are negatively associated with coronary heart disease risk.

Thymulin (Zn-facteur thymique serique) activity in anorexia nervosa patients.

Thymulin (or FTS-Zn) a well-defined thymic hormone was studied in fifteen female patients hospitalized for anorexia nervosa. The circulating hormone was measured together with the plasma levels of thyroid hormones, cortisol and zinc. Thymulin activity determined by the rosette assay was significantly reduced in the anorexia nervosa patients compared to sex- and age-matched healthy control subjects. The patients were characterized by very depressed plasma levels of triiodothyronine (T3) but exhibited normal concentrations of thyroxine (T4), thyroxine-binding globulin (TBG), cortisol and zinc. The distribution of their peripheral lymphocyte cells into several subsets was not affected. The observed decrease of thymulin activity in this illness might be the consequence of thymic atrophy secondary to malnutrition and/or hormonal disturbances. Our results suggested that the fall in thymulin level might explain the variability of cellular immune responses in anorexia nervosa patients and occurrence of energy when their weight loss is far advanced.

A simplified method for the preparation of rat thyroxine-binding prealbumin. Factors influencing its circulating level.

Rat thyroxine-binding prealbumin (TBPA) was isolated in three simple steps by means of a serum precipitation by a 5% phenol solution and two consecutive semi-preparative polyacrylamide gel electrophoreses. The overall yield was 15% and the TBPA preparation contained less than 1% impurities. In addition a monospecific antiserum was raised in the rabbit. In polyacrylamide gel, rat TBPA, as with its human counterpart, migrated anodally to albumin while in agarose gel, its electrophoretic mobility was similar to that of albumin. Serum TBPA measured in adult male Wistar rats did not exhibit a circadian rhythm. However, a significant 13% decrease was observed between 9 and 15 h, followed by the restoration of the initial value by 21 h. TBPA concentration was measured in 1-, 15- and 28-day-old male and female pups as well as in adult rats. The level of this protein increased from 1 to 28 days of age and did not display any sexual difference. Yet, while TBPA concentrations in adult males were similar to those recorded in the 28-day-old pups, for adult females, they returned to the levels measured in the 1-day-old pups.

Early nutritional experiments: effects on the humoral and cellular immune responses in mice.

Studies were carried out to determine the effect of varying intake during the suckling period on the immune responses of mice. Female mice were bred in litters of 4, 9 or 20 pups. Litters of nine pups were considered control groups. Overfeeding (litters of 4) during this period did not change the serum protein profile nor the humoral and cellular immunity of the weanling mice, as judged by their plaque-forming cell responses to SRBC and lymphocyte stimulation in vitro by Con A or LPS. Conversely, mice bred in large litters showed, at weaning, decreased serum levels of albumin and alpha-globulins but did not exhibit marked alterations of their immune responses, although they were in a severe state of protein-energy deficiency. After weaning, feeding a normal diet ad libitum normalized all the altered parameters tested in the malnourished mice. However, when malnutrition was followed by intermittent feeding, the studied immunological functions were significantly affected: the humoral, as well as the cell-mediated immune responses were depressed. These observed alterations were not related to changes in the levels of serum corticosterone or zinc. Our findings suggested that differences in the length of dietary deficiency rather than its severity may explain some of the conflicts in reports on functional immune tests in protein-energy malnutrition.

Absence of variation in facteur thymique sérique activity in moderately and severely malnourished Senegalese children.

Facteur thymique sérique activity was evaluated in relation to different types of malnutrition in Senegalese children aged 5 to 42 months. They were classified in four groups: controls, moderate malnutrition, marasmus, and kwashiorkor, according to anthropometric measurements and clinical examination. The two latter groups were characterized by very depressed levels of total protein, album in, transferrin and prealbumin, and by high cortisol concentrations. Zinc status was marginal in all children. Facteur thymique sérique activity, determined by the rosette assay, was normal in the malnourished patients suggesting that moderate as well as severe malnutrition is not necessarily associated with depressed levels of circulating thymic hormone. These results are discussed in relation to zinc status and infections.

Food intake and energy expenditure of male and female farmers from Upper-Volta.

1. The energy balance of eleven male and fourteen female adult farmers was measured for 6 d after the harvest, in December-January. Their energy intake was recorded by weighing their food consumption and their energy expenditure was determined using indirect calorimetry. 2. Body-weight, expressed as percentage of expected weight-for-height was 91 and 86% of the Inter-departmental Committee on Nutrition for National Development (1963) standard for women and men respectively. 3. The staple foods were sorghum (Sorghum vulgare) and millet (Pennisetum typhoïdes); carbohydrates, fat and protein supplied approximately 80, 13 and 12% of the total energy of the diet respectively. 4. In the male group, the mean energy intake (9.0 MJ (2148 kcal)) was in good agreement with the average energy output (8.91 MJ (2130 kcal)). By contrast, in the female group, the mean energy expenditure (8.11 MJ (1941 kcal)) exceeded the mean energy intake (6.3 MJ (1515 kcal)) and the deficit was statistically significant. 5. This study allows an evaluation of the adequacy of food intake for subjects living in a particular hostile environment, by using their actual energy output instead of current standard values. The energy deficit found for female farmers whose energy intake was similar to that reported in other developing countries emphasizes the need for a better understanding of the regulation of energy balance in such conditions.

Energy expenditure of male farmers in dry and rainy seasons in Upper-Volta.

1. Thirty Mossi male farmers from Upper-Volta were investigated, twenty-three in the dry season (March-April) and sixteen in the rainy season (July-August), eight of them being studied twice. A 48 h time-and-motion study was carried out and the daily energy expenditure was computed. 2. The mean height was 1.70 m and the mean weight 58.5 kg. The averaged percentage of body fat calculated from skinfold thickness was 10. 3. During the dry season the subjects could be classified as very moderately active with an energy output of 10.0 MJ (2410 kcal)/d. By contrast, with an energy expenditure of 14.4 MJ (3460 kcal)/d, they were considered as exceptionally active in July-August when performing the agricultural work. 4. In this study we measured the intensity of physical work in a society where human labour is still the main tool of production. The determination of seasonal variations in energy expenditure may be useful to assess the nutritional requirements in arid zones of West Africa.

Duration of activities and energy expenditure of female farmers in dry and rainy seasons in Upper-Volta.

1. Fifteen female farmers (aged 18--47 years) from two villages of the Mossi Plateau in Upper-Volta participated in a survey in which their daily activity pattern and their energy expenditure were assessed. Eight of the subjects were investigated twice, in March (dry season) when there is no agricultural activity, and in July--August (rainy season) when heavy physical work is performed: mostly hoeing, weeding and replanting sorghum (Sorghum vulgare) and millet (Pennisetum typhoïdes). 2. The mean height was 1.57 m and the mean weight 50.6 kg. The average percentage of body fat, calculated from skinfold thickness, was comparable to that of European females but the triceps skinfold was more than 60% below the standard value (Jelliffe, 1969). The type of activities and the period of time spent on each activity changed significantly with the season. The mean energy output rose from 9.7 MJ (2320 kcal) in March to 12.1 MJ (2890 kcal) in July--August for a 55 kg standard weight. 3. In this paper, the extent of both the daily activity pattern of women living in a subsistence agriculture and their energy output is estimated. The results suggest that during the rainy season, the energy requirements of female farmers are much higher than usually estimated.