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Biomedical subjects

C J Bates

Publications and source records attributed to C J Bates.

At least 109 records · Page 6Linked to original sources
PubMed1989

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.

Adolescent↗
PubMed1989

Metabolism of [14C]adipic acid in riboflavin-deficient rats: a test in vivo for fatty acid oxidation.

Mitochondrial preparations from riboflavin-deficient rats are known to exhibit reduced capacity for the oxidation of fatty acids. During a search for a suitable fatty acid probe for the in vivo exploration of this phenomenon, it became apparent that a dicarboxylic acid, adipic acid, was more promising than a monocarboxylic acid such as octanoic acid. Rats made riboflavin deficient, and controls at various stages of development, were dosed intragastrically with [1,6-14C]adipic acid, and 14CO2 production was measured for 3 h. All animals were then given flavin mononucleotide intragastrically to replete their tissues, and the [14C]adipic acid test was repeated at intervals thereafter. In all groups, repletion produced a highly significant increase in the whole-body adipic acid oxidation index, and reversed the low rates of oxidation which had been observed in nonrepleted, deficient animals. This approach may therefore permit the development of a new functional test for fatty acid oxidation in human riboflavin deficiency, and for other conditions in which fatty acid oxidation pathways are impaired, by the use of nonradioactive [13C]adipic acid.

Adipates↗
PubMed1989

Liberation of 14CO2 from 14C-fatty acids by riboflavin-deficient sucking rat pups: a study of 14C-Octanoate and 14C-palmitate oxidation in vivo.

To test the hypothesis that impaired fatty acid oxidation in the mitochondria of riboflavin-deficient rats may be reflected in impaired rates of fatty acid oxidation to carbon dioxide in vivo, the conversion of 14C-labelled fatty acids to 14CO2 was measured in rat pups. Sucking pups were selected, since whole body energy expenditure was reduced by riboflavin deficiency in this age group. A gas-flow apparatus was designed, to permit the collection of expired CO2 over a 4 hr period, in pups maintained at constant temperature. 14C-octanoate and 14C-palmitate, given by intraperitoneal injection, were oxidised to 14CO2, with peak production rates at 20 min and at 30 min respectively. Cumulative recoveries of the injected 14C were: ca. 50% of the dose for 14C-octanoate, and ca. 20% of the dose for 14C-palmitate, during 4 hr collection of expired air. Per unit of body weight, the rates and extents of oxidation of each fatty acid substrate in riboflavin-deficient pups were not significantly reduced in comparison with their pair-fed or ad-lib fed, riboflavin-sufficient controls. This study a) has confirmed the feasibility of the 14C-fatty acid-breath test assay for sucking rat pups; b) has excluded the possibility of massive reductions due to riboflavin deficiency in the oxidation of two fatty acid substrates, and c) has provided estimates of biological variation of these indices, which will assist future studies.

Animals↗
PubMed1988

Effects of age and dietary vitamin C on the contents of ascorbic acid and acid-soluble thiol in lens and aqueous humour of guinea-pigs.

Variations in ascorbate and thiol concentration in lens and aqueous humour, with age and vitamin C nutrition, are of potential biological importance. To study these relationships, Dunkin-Hartley guinea-pigs were maintained for periods of up to 1.3 yr on diets containing either high or low (marginal) vitamin C. Ascorbate contents of liver, spleen, adrenals, lens and aqueous humour, and acid-soluble thiol of lens and aqueous humour were measured. High vitamin C intake maintained ascorbate levels in the internal organs between five and 30 times the level attained by the low vitamin C intake and aqueous humour vitamin C was 10-20 times higher at high vitamin C intake. Lens ascorbate, however, was only about twice as high at high vitamin C intake than at low intake, and at both intake levels it declined steadily to about half its initial value, after 1.3 yr. Thus an animal aged 1.3 yr on the low intake had about one-quarter to one-fifth of the lens ascorbate level of a young animal receiving a generous intake. Acid-soluble thiol in the lens, in contrast to ascorbic acid, increased significantly with age but was not significantly affected by dietary vitamin C intake. Acid-soluble thiol in the aqueous humour was only 0.5-2% of the concentration found in lens, and unlike the lens thiol level, it declined with age. No sex differences were observed for ascorbate or thiol levels either in lens or in aqueous humour.

Adrenal Glands↗
PubMed1988

The effects of dietary folate and zinc on the outcome of pregnancy and early growth in rats.

1. The objective of the present study was to determine the effects of two levels of folic acid and two levels of zinc in the diets of rats during pregnancy and lactation. It addressed, among other things, the question of whether an inhibitory effect of folic (pteroylmonoglutamic) acid on Zn absorption might result in a secondary Zn deficiency in either the dams or the pups. 2. A purified diet was given to four groups of female DNL (Norwegian) Hooded rats, before and during pregnancy and during lactation. It contained the four possible combinations of: no added folic acid or 100 micrograms added pteroylmonoglutamic acid/g, and 6.6 or 20.2 micrograms Zn/g. Pups and dams were killed on day 20 of gestation or on day 20 postpartum. Measurements of body-weights, food intakes, blood folate and tissue Zn levels were performed. 3. The group with low Zn and low folate intake had a satisfactory reproductive outcome, and there were only minor effects of the supplements on body-weights. 4. Additional folate greatly increased blood (erythrocyte and plasma) folate levels, but did not compromise tissue Zn concentrations. Zn supplementation also enhanced blood folate levels, for reasons which are not yet clear. 5. There was a moderate enhancing effect of the Zn supplement on Zn levels in the livers and kidneys of pregnant dams, and the kidneys of lactating dams. 6. If the conclusions can be extrapolated to humans, then the results provide some reassurance that a high folate intake from prenatal supplementation need not necessarily cause Zn depletion, and hence functional Zn deficiency in pregnant women and their offspring.

Animals↗
PubMed1988

Growth, ascorbic acid and iron contents of tissues of young guinea-pigs whose dams received high or low levels of dietary ascorbic acid or Fe during pregnancy and suckling.

1. Guinea-pig dams were fed on purified diets containing high (5 g/kg diet plus 1 g/l drinking water) or moderate (0.5 g/kg diet) levels of ascorbic acid, in combination with high (1 g/kg diet) or moderate (0.043 g/kg diet) levels of iron, during pregnancy and suckling. Their offsprings' diets contained 0.1 g ascorbic acid/kg and 0.04 g Fe/kg. 2. High ascorbic acid intake clearly enhanced both tissue ascorbate and Fe storage in the dams, and high Fe intake increased both the dams' and the pups' tissue Fe stores. 3. In the animals receiving high Fe intake, a co-existing high ascorbate intake by the dams reduced the growth rate of the offspring, but only during the early stages of development, not during the later stages of post-weaning growth. All the pups' tissue ascorbate levels fell after weaning, but those born of the dams receiving the high ascorbic acid diets did not fall to levels lower than those of the other pups. 4. Thus, although certain disadvantages to the offspring resulting from very-high ascorbic acid intake by pregnant guinea-pig dams were detected, these did not include permanently increased ascorbate requirements, and hence a progression to scurvy as the pups grew and matured.

Animals↗
PubMed1988

The effects of antimalarials and folate supplements on haematological indices and red cell folate levels in Gambian children.

Haematological indices and red cell folate levels (RCF) were measured during two annual surveys in a group of Gambian children aged 3 months-5 years who were participating in a trial of malaria chemoprophylaxis with Maloprim or chlorproguanil given with or without folate supplements. Chlorproguanil was given in an adult dose of 20 mg, Maloprim as one quarter or one half of the adult dose of 25 mg pyrimethamine and 100 mg dapsone. Antimalarials and folate supplements were given fortnightly. About 20% of children had low RCF levels (less than 100 ng/ml). Among children who did not receive supplementation with folate there were no significant differences in mean RCF levels between children who received Maloprim, chlorproguanil or placebo. Among children who received folate supplements, the mean RCF was significantly lower among those receiving chlorproguanil than among the controls. Mean RCF values were similar in children who received Maloprim or placebo. If chlorproguanil is used for malaria chemoprophylaxis in young children an age-related dose should be used.

Antimalarials↗
PubMed1988

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.

Adolescent↗
PubMed1987

Micronutrient deficiencies in the aetiology of anaemia in a rural area in The Gambia.

Early studies in a rural community in The Gambia led to reports of anaemia in certain sections of the population. More recent investigations concerned with identifying micronutrient deficiencies have elaborated these earlier findings. The major determinant of anaemia is an iron deficiency, leading to a microcytic hypochromic haematological picture. However, riboflavin deficiency, which is very widespread, and which leads to clinical signs in some subjects, appears to impose some limitations on absorption and utilization of iron. A subclinical deficiency of ascorbic acid is also observed and this may further compromise iron status. In addition very poor folate status leads to a macrocytosis in some individuals and may limit the haematological response to iron supplementation.

Adolescent↗
PubMed1987

Effect of supplementary vitamins and iron on malaria indices in rural Gambian children.

The effect of a combined supplement of iron, thiamine, riboflavin and vitamin C on malarial incidence in 5 to 14-year-old children was tested in a malnourished rural community in a region of The Gambia noted for high prevalence of malaria during the rainy season. 190 children, divided into 2 matched groups, received either the supplement or a matching placebo for 3 months. No significant difference in malarial incidence was observed between the 2 groups, despite a major improvement in biochemical indices of nutrient status in the supplemented group, especially for riboflavin and vitamin C. Severity of episodes was also similar between groups, but in subjects who developed parasitaemias there was a trend towards higher parasite counts in those receiving the active supplement. Nutritional interventions in malarious areas may have adverse effects on malaria, and the increase in parasitaemia was compatible with the hypothesis that a small but significant reduction in defences had occurred. However, the absence of increases in the incidence of proven malaria cases and their severity must also be taken into account, in order to make a balanced assessment of the possible increase in risk. Further investigations are needed to measure the risk in benefit rates, and to consider the effects of individual nutrients in isolation.

Adolescent↗
PubMed1987

Riboflavin, folate and vitamin C status of Gambian women during pregnancy: a comparison between urban and rural communities.

Anthropometric, haematological and vitamin status indices were measured in a group of pregnant women living in the urban community of Bakau in The Gambia, West Africa. Their haematological and anthropometric indices were generally within normal limits. Vitamin C status was also acceptable and was similar to values observed in rural Gambian women sampled at the same time of year. Folate status was similar to that seen previously in rural Gambian communities, and there was a strong intrasubject correlation between plasma and red cell folate levels, together with a trend towards higher values as pregnancy progressed. This was consistent with probable compliance with local recommendations for folate supplementation during pregnancy. The urban Gambian women also resembled their rural counterparts in having very poor biochemical riboflavin status, which deteriorated as pregnancy progressed. In this respect they differed markedly from UK women, who had satisfactory riboflavin status even in late pregnancy. The existence of severe biochemical riboflavin deficiency, even in urban Gambian women, whose anthropometric indices are not compatible with severe general malnutrition, suggests that a deficiency of this vitamin may be widespread in Sahelian West Africa. Measures to improve maternal vitamin status during pregnancy would therefore be equally appropriate in both rural and urban communities.

Adult↗
PubMed1987

Atrophic gastritis and vitamin C status in two towns with different stomach cancer death-rates.

A survey was conducted of 513 men aged 65 74 years living in two British towns with high and low stomach cancer death-rates. The prevalence of severe atrophic gastritis (defined as a serum pepsinogen I less than 20 micrograms l-1) was significantly higher in the high-risk than in the low-risk town (14.5% and 7.7% respectively); it also tended to be higher in the manual workers, who are known to have a greater risk of stomach cancer than non-manual workers. The manual workers in the high-risk town were particularly likely to have had a partial gastrectomy. Plasma ascorbate concentration and fruit intake were lower in the high-risk area and lower social classes, suggesting a poorer vitamin C status. There was, however, no direct relationship between ascorbate concentration and the presence of severe atrophic gastritis. These findings are consistent with the hypothesis that risk of stomach cancer is determined in two stages--a long-term effect, producing atrophic gastritis; and a short-term effect in which vitamin C is protective.

Aged↗
PubMed1987

Occurrence and significance of riboflavin deficiency in preterm infants.

Few studies have explored the importance of riboflavin deficiency in premature infants. Infants receiving human milk during the first 2 weeks become biochemically riboflavin-deficient, partly through photodegradation of riboflavin during the banking and delivery of human milk. Animal studies have shown that the metabolic lesions of riboflavin deficiency in sucking neonates differ in important ways from those seen later after weaning. Techniques are described for non-invasive study of functional riboflavin requirements by premature infants. It appears prudent to supplement human milk-fed babies with at least 300 micrograms riboflavin/day; but the potential danger of over supplementation in infants exposed to phototherapy is discussed.

Disease Models, Animal↗
PubMed1987

Dietary intake of vitamin A precursors by rural Gambian pregnant and lactating women.

In view of the apparent paradox of low dietary intakes of vitamin A by rural Gambian women, which is not accompanied by deficient biochemical or physiological indices (Bates, 1983), a detailed study was undertaken, in which dietary intake was remeasured by direct weighed food intakes, coupled with chemical analysis of the carotene content of key food components. This was combined with recall data on dietary patterns in order to obtain a precise picture of carotene intakes throughout a twelve month period, with supplementary information spanning 4 years. Major contributors to dietary carotene intake were mangos (brief period of local availability during the dry season), leaf sauces (mainly rainly season), and small amounts of red palm oil (purchased by the more wealthy families). Preformed vitamin A made only a very small contribution to the diet. For 35 subjects studied during pregnancy in the village of Manduar, the geometric mean home food carotene intake was 0.81 mg/day, and for 61 pregnant subjects from the village of Keneba, the geometric mean home food carotene intake was 0.62 mg/day. However, there were large individual variations. While the efficiency of conversion of carotene to retinol is not known precisely, it is clear that these intakes are considerably below the current recommended dietary allowance for vitamin A during pregnancy, and especially during lactation.

Carotenoids↗
PubMed1987

Effect of vitamin A supplementation on plasma and breast milk vitamin A levels in poorly nourished Gambian women.

Plasma and breast milk vitamin A and plasma carotenoids were measured in groups of pregnant and lactating women in two neighbouring rural Gambian villages. One of the groups (Keneba) received a 650 micrograms daily vitamin A supplement. During pregnancy, plasma retinol values were significantly (19 per cent) higher in the supplemented group. During lactation, breast milk values were significantly (23 per cent) higher in the supplemented group. Changes in plasma and breast milk vitamin A levels during the cycle of pregnancy and lactation and with season are also described, and the value of a combined index of plasma retinol and plasma carotenoids is illustrated. The significant effect of a prolonged low level vitamin A supplement to pregnant and lactating women has important implications for nutrition intervention programmes.

Adult↗