Human nutrition. Clinical nutrition最新文献

Cell-mediated immune response, antibody titres and morbidity were measured among children residing in a slum area following measles vaccination. Effect of malnutrition on the development of protective levels of antibody titres was also investigated. Of the vaccinated children 87 per cent had antibody titres above 1:8 and nutritional status had no influence on this. Cell-mediated immune response was similar before and after vaccination. However, morbidity due to other infections was less in vaccinated children compared to the controls and could be due to stimulation of non-specific host resistance mechanisms.

This report consists of two separate studies. Study I was a prospective one in which 23 pregnant women ultrasonically diagnosed as having small fetuses were compared with 22 women with large fetuses. Maternal plasma zinc concentrations pre- and post-35 weeks gestation were significantly higher in mothers of small than in mothers of large infants. Twelve women with normal pregnancies participated in study II. Biochemical data obtained in maternal plasma during the third trimester of pregnancy, including total, albumin-bound and alpha 2-macroglobulin-bound plasma zinc concentrations and plasma copper concentration were compared with infant anthropometric data at birth. The results indicated significant negative correlations between maternal plasma zinc and albumin-bound zinc concentrations and plasma copper concentration in the third trimester of pregnancy and mid-arm circumference and ponderal index. The results of these studies, in the light of other data reported for primates and humans, suggest the need for a more extensive investigation of the relationship between maternal circulating zinc and copper concentrations and fetal growth.

Waist-hip circumference ratio (WHC ratio) and body mass index (BMI) were calculated from measurements of a semi-random, age-stratified sample of 4349 British men, aged 20-64 years, body weight 75.6 +/- 11.6 kg (mean +/- s.d.) and BMI 24.7 +/- 3.4 kg/m2. The mean WHC ratio was 0.89 +/- 0.06; it increased with age and overweight separately and in combination, R2 = 47 per cent. BMIs greater than or equal to 30 were found in 7 per cent of the sample and WHC ratios greater than or equal to 1 in 4 per cent of the sample. Forty-seven per cent of these latter individuals also had BMI greater than or equal to 30, but only 28 per cent of individuals with BMI greater than or equal to 30 had WHC ratios greater than or equal to 1. These indices suggest that in men abdominal obesity and whole-body obesity are usually separate conditions and that abdominal obesity is less common than obesity.

The pattern and composition of weight change in 19 Kenyan children convalescing from measles, while eating a traditional diet at home, was investigated by serial anthropometry. The majority of children gained weight satisfactorily, 9 (47 per cent) quadrupling the reference rates of weight gain during this period, although 4 remained severely underweight throughout the study. The significant mean improvement in nutritional status, estimated by weight/length, was the result of weight gain accompanied by faltering in linear growth. Rapid weight gain was characterized by an early increase in the fat-free weight and a later rise in subcutaneous fat weight, similar to that shown in children recovering from malnutrition. Children who gained weight poorly demonstrated alternate spurts of weight gain and weight loss. Poor weight gain was significantly (P less than 0.05) associated with anorexia and with diarrhoea. Nutritional and metabolic factors influencing the pattern of weight gain and linear growth after infection are discussed.

Non-protein nitrogen from human milk is presently being implicated in neonatal physiology. Human milk contains relatively high amounts of nucleotides which are practically absent in cow's milk and milk formulas. These compounds have been related to normal growth and cellular immunity in animals in early life. The aim of this study was to investigate the effects of dietary nucleotides on the plasma fatty acid pattern in term neonates during the first month of life. Twenty-six infants were fed human milk, 35 a milk formula and 23 the same formula supplemented with cytidine, adenosine, guanosine, uridine and inosine 5'-monophosphates in similar quantities to those determined in human milk. Plasma polyunsaturated fatty acids with more than 18 carbons of the omega 6 family were significantly increased in infants fed with the nucleotide-supplemented milk formula with respect to those fed the milk formula, whereas no differences could be detected between the human milk-fed and the nucleotide milk formula-fed ones. These results suggest that dietary nucleotides may be involved in the conversion of linoleic acid to longer chain polyunsaturated fatty acids during early life.

The mechanism of pathogenesis underlying the development of corneal lesions in measles was investigated in 125 children suffering from measles and 66 age- and sex-matched healthy controls. Forty age-matched children with bronchopneumonia were investigated on similar lines to delineate the role played by vitamin A and measles individually in the development of corneal lesions. The results indicate that the pathogenesis of corneal lesions in measles is indeed multifactorial. Vitamin A deficiency alone or measles keratitis per se may not explain the mechanism completely. The immunosuppression induced by the local proliferation of the measles virus in the eye might trigger the invasion of pathogenic microbes which damage the cornea. The structural integrity of the cornea is already compromised by vitamin A deficiency and lesions of measles keratitis.

We have studied the completeness of urine collections in 11 European centres. The completeness of collection was examined by questioning the participants, by calculating the ratio of observed to expected creatinine, and by measuring the recovery of p-aminobenzoic acid (PABA) in the urine after administration of a 240 mg dose. The ratio of observed to expected creatinine is a fairly insensitive measure of undercollection. People who report that their collection is incomplete are likely to have collected incompletely to a considerable degree. It was concluded that the use of PABA in epidemiological studies is still questionable; overcollection cannot be detected by using PABA, and it appeared that people sometimes forget or refuse to take the capsules. It is also suggested that differences in the meal-time patterns between countries may interfere with the PABA recovery test.

The effects of combined oral contraceptives containing 30 or 50 micrograms ethinyl oestradiol and 150 micrograms levonorgestrel or a 3-monthly injectable preparation depo-medroxyprogesterone acetate (DMPA) on the vitamin status of low-income group women from two urban centres in India (Bombay and Hyderabad) and one rural centre in Thailand (Chiang Mai) were examined in a follow-up study over a period of 1 year. The magnitude of malnutrition in the study population vis-à-vis a middle-income reference group was assessed by comparing the baseline data on the two groups. Effects of time-related variables such as lactation and season were also examined by a cross-sectional analysis of the baseline data on the study population. In all three centres the majority of the study population suffered from biochemical riboflavin and/or pyridoxine deficiency even before initiating contraception. Lactation appeared to have an effect on the vitamin status, which varied among the different populations. Seasonal effects were seen, but showed inconsistent trends in the three centres. Both the oral contraceptive pills and DMPA tended to increase serum vitamin A and blood folate. The thiamin, riboflavin and pyridoxine status of the women who were already deficient did not deteriorate further with the use of hormonal contraception, as judged by enzyme saturation tests. Some deterioration in the riboflavin status of the normal women of Hyderabad was seen with the use of oral pills. Women who were biochemically deficient prior to the use of oral contraceptives tended to show some improvement in B-vitamin status, over the 1-year period of hormonal contraception.

This paper reports the intra-individual variability of creatinine excretion under conditions of variable food intake and stress. Urine collections over 24 h were made by six subjects for 24 d in the course of an expedition to the Colombian Andes. The average coefficient of variation (CV) of day-to-day creatinine excretion was 11.4 per cent and of N excretion 28 per cent. When the outputs were averaged by 3-d period the mean CV of creatinine excretion was reduced to 5.7 per cent. It is concluded that in metabolic studies the 3-d creatinine excretion is a useful index even when food intakes and other conditions are not controlled.

Fifteen patients with idiopathic chronic pancreatitis (aged 17-78 years), who had not altered their diet since their first symptoms, completed 7-d weighed dietary records at home. The computed information was compared with that from 15 age- and sex-matched volunteers. Attention was focussed on the intakes of antioxidants and unsaturated fatty acids. The patients ingested less selenium, vitamin E, vitamin C and riboflavin than did controls (P less than 0.001, P less than 0.02, P less than 0.001 and P less than 0.05 respectively, using paired t-tests): selenium was by far the best discriminator on step-wise analysis. When the selenium intakes were examined alongside the results of theophylline tests--which reflect cytochromes P450 activities and, thereby, provide an index of antioxidant demand--a line of discrimination separated the majority of patients (with faster drug clearances and lower selenium intakes) and controls. There were no differences in the intakes of individual unsaturated fatty acids, C14:1 through to C24:6, between the two groups. However, amongst six subjects in the overlap zone, three with chronic pancreatitis habitually ate greater amounts of highly unsaturated fatty acids C20:4 to C24:6 inclusive (1970, 1049, 750 mg/d) than did three controls (329, 320, 82 mg/d). Animal experiments show that suboptimal intakes of dietary antioxidants and/or excessive intakes of highly unsaturated fatty acids and/or induction of cytochromes P450 facilitate peroxidation of cellular lipid membranes by free radicals. Our dietary data, taken in conjunction with pharmacokinetic data, thus suggest that a similar situation--favouring lipid peroxidation--may underlie human chronic pancreatitis.