Biomedical subjects

A M Prentice

Publications and source records attributed to A M Prentice.

At least 163 records · Page 9Linked to original sources

PubMed1984

Breast-milk antimicrobial factors of rural Gambian mothers. I. Influence of stage of lactation and maternal plane of nutrition.

The concentrations of IgA, IgG, IgM, C3, C4, lactoferrin, lysozyme and secretory component in the mature breast milk of 152 rural Gambian mothers were measured up to 26 months lactation. The concentrations and daily secretion of all the immunoproteins, except lysozyme, decreased during the first year of lactation, but were well maintained thereafter. The production of lysozyme increased progressively throughout lactation. Compared with 10 mothers in Cambridge, U.K., the daily secretion of IgG, IgM, C3 and C4 was higher in The Gambia, that of IgA and lactoferrin was similar in the two communities, and that of lysozyme and secretory component was lower in The Gambia. A dietary supplement given to 90 Gambian mothers, raised the mean daily energy intake from a maximum of 1650 kcal/day and a hungry-season minimum of 1 200 kcal/day to 2 300 kcal/day throughout the study. The supplement did not enhance the production of breast milk immunoproteins.

Complement C3↗

PubMed1984

Breast-milk antimicrobial factors of rural Gambian mothers. II. Influence of season and prevalence of infection.

The effects of season and variations in the prevalence of infectious disease on the concentrations and daily production of breast-milk immunoproteins were studied in 152 rural Gambian mothers and their children up to 26 months post-partum. IgA, IgG, IgM, C3, C4, lactoferrin, lysozyme and secretory component concentrations and breast-milk volumes were measured longitudinally over a six month period which encompassed dry and rainy seasons. No increase in the production of any immunoprotein was observed at the time of maximum prevalence of serious infectious diseases, especially diarrhoea, in the children. Enhanced secretion of certain immunoproteins was noted in mothers of children aged 9-18 months at the beginning of the rainy season. There was some evidence that this may have been associated with skin sepsis, particularly impetigo, in the children. The production of most immunoproteins fell during the rainy season. This was not the result of declining maternal food intakes as similar decreases were seen for women receiving a dietary supplement.

Bacterial Infections↗

PubMed1984

The impact of malnutrition on human lactation: observations from community studies.

There is very little scope for the direct examination of relationships between nutrient intake and lactational performance in women. Experimental investigations are limited to the effects of dietary supplementation in pregnancy and/or lactation. To obtain comparisons between normal and undernourished women, studies have to be performed at a community level. Studies in Cambridge, The Gambia, and elsewhere indicate that the impact of variations in nutrient intake on lactational performance is limited: over the ranges normally found in developed and developing countries milk output does not vary in relation to energy intake, and effects of nutrient intake on milk quality are restricted to increases in vitamin content after appropriate supplementation.

Birth Weight↗

PubMed1984

Efficacy of a food supplement in correcting riboflavin deficiency in pregnant Gambian women.

Pregnant women living in rural Gambian villages, whose natural riboflavin intake is about 0.5 mg/d, have abnormal biochemical riboflavin status and signs of clinical deficiency. A vitamin-fortified food supplement given in one village which increased the riboflavin intake to about 1.3 mg/d was followed by a substantial improvement in biochemical status, although seasonally-related variations in status somewhat complicated the picture. It was calculated that the amount of riboflavin needed to satisfy the requirement, for normal biochemical status, of the majority of pregnant women throughout pregnancy and throughout the year, is about 2.6 mg/d. Clinical signs associated with riboflavin deficiency, especially atrophic lingual papillae, showed significantly reduced incidence in the supplemented, compared with an unsupplemented, village. Cord blood values of the activation coefficient of erythrocyte glutathione reductase were in the abnormal range for 84 per cent of infants before introduction of the supplement, but were abnormal for only one of 12 infants after its introduction. Thus even a suboptimal maternal riboflavin intake of about 1.3 mg/d appears to be sufficient to prevent biochemical deficiency in cord blood, and to reduce considerably the incidence of clinical deficiency signs during pregnancy.

Adult↗

PubMed1983

Prenatal dietary supplementation of African women and birth-weight.

Gambian women, who show marked seasonal fluctuations in energy balance, were offered a dietary supplement during pregnancy. This resulted in a net energy increment of 431 kcal/day. In the wet season, when the women were normally in marked negative energy balance due to food shortages and a high agricultural work load, the supplementation improved birth-weight by a mean of 224 g and reduced the incidence of low-birth-weight babies (less than 2.5 kg) from 28.2% to 4.7%. In the dry season, when the women were previously in positive energy balance despite an energy intake of only 60% of the recommended dietary allowance, the supplement had no beneficial effect on birth outcome. This threshold effect indicates the need to identify truly at-risk groups for prenatal supplementation programmes in developing countries.

Birth Weight↗

PubMed1983

A trial of ascorbic acid and of multivitamin supplementation on the oral health of West African children.

204 children between the ages of 1.5 and 6.5 years living in a West African village where the incidence of gingivitis and bleeding gums is about 40% of the population at the end of the rainy season, were given vitamin C or a placebo for 69 days, followed by a multivitamin supplement or placebo for 47 days. The condition of their gums was continuously monitored by trained field workers and by a paediatrician during the supplementation period, and was also assessed in greater detail by the paediatrician at the beginning and end of each treatment period. No benefit of either type of supplement could be detected, either on incidence of bleeding, or on over-all severity of gingivitis, although there was a clear-cut seasonal trend towards lower incidence of bleeding in both groups as the study progressed.

Ascorbic Acid↗

PubMed1983

A prospective survey of gingivitis in Keneba, a rural West African community.

The prevalence and severity of gingivitis was studied in 204 children living in a rural West African community. Seasonal prevalence varied from 38.6% to 9.5%. The lowest prevalence coincided with the seasonal consumption of citrus fruits and mangoes. Prevalence increased with age. Of the children, 13.7% required treatment with a standard antibiotic regime for severe gingivitis. Severe gingivitis occurred frequently in children under three years of age and in females. There was no clear relationship between the prevalence of gingivitis and malnutrition as assessed by anthropometric indices obtained from the children. Findings in this study suggest that measures to improve oral hygiene is the intervention most likely to reduce the prevalence of gingivitis.

Age Factors↗

PubMed1983

Determinants of variations in breast milk protective factor concentrations of rural Gambian mothers.

The concentrations of 7 immunoproteins (IgA, IgG, IgM, the complement components C3 and C4, lactoferrin, and lysozyme) in the breast milk of 152 rural west African women were measured as part of a semilongitudinal study to assess their importance in infant health. Each mother maintained a characteristic level of production of immunoproteins relative to other mothers, and the concentration of each immunoprotein within each woman was correlated positively with the others. Parity was the major determinant of ranking and mothers of parity 1 and 2 produced the highest concentrations of immunoproteins. Except for lysozyme, infants' intake of these protective factors decreased in early lactation, but infants aged 1-2 years still received substantial amounts. The daily intakes by Gambian infants were similar to or higher than those of infants in Cambridge, United Kingdom. A marked seasonal increase in infant morbidity was not accompanied by an increase in the concentrations of protective factors in mothers' milk.

Complement System Proteins↗

PubMed1983

Dietary supplementation of lactating Gambian women. I. Effect on breast-milk volume and quality.

In order to test whether lactational capacity can be improved by dietary interventions, a nutritionally balanced supplement was provided under carefully controlled conditions to 130 nursing mothers in Keneba, The Gambia over 12 months. Maternal mean energy intake (+/- s.e.) increased from 1568 +/- 15 kcal/d (6.56 +/- 0.06 MJ/d) to 2291 +/- 14 kcal/d (9.59 +/- 0.06 MJ/d). Protein intake was in excess of the WHO/FAO recommended intake after supplementation and serious deficits of riboflavin, vitamin A, vitamin C and calcium were rectified. The supplement had no effect on breast-milk volume, compared with retrospective controls, at any stage of lactation or in any season of the year. There was no selective effect on women with poor milk outputs. The average milk protein concentration was slightly improved over the entire period of lactation (+ 6.6 per cent, P less than 0.01), but the total energy content was unchanged since an increase in breast-milk fat concentration (+ 7.9 per cent, n.s.) was offset by a decrease in the milk lactose concentration (- 7.6 per cent, P less than 0.01). Breast milk vitamin content was improved for those vitamins for which the supplement provided a significant proportion of the recommended dietary intake.

Adult↗

PubMed1983

Efficacy of a riboflavin supplement given at fortnightly intervals to pregnant and lactating women in rural Gambia.

Thirty-seven women living in two rural Gambian villages, who were either pregnant or lactating at the outset of the study, received a tablet containing 15 mg riboflavin, or a placebo, at fortnightly intervals for 10 weeks at a time of year when riboflavin status was deteriorating. Clinical assessments were carried out once a week, with particular attention to signs and symptoms of riboflavin deficiency, and blood samples were taken at the beginning of the study and after 4 and 10 weeks supplementation for the assessment of riboflavin status by the activation coefficient of erythrocyte glutathione reductase. The overall incidence of lingual papillary atrophy increased significantly during the course of the study, but the increase was significantly smaller in the supplemented than in the placebo group. More complaints of sore mouths were encountered in the placebo group. Biochemical evidence of deficiency was very marked at the outset, and showed some improvement after supplementation, but values within the normal range were not achieved. It is concluded that a riboflavin supplement given at spaced intervals can be clinically beneficial, despite failure to achieve normal biochemical indices. This may have practical implications for intervention programmes.

Atrophy↗

PubMed1983

Metabolic consequences of fasting during Ramadan in pregnant and lactating women.

In studies in a rural West African village it was observed that all lactating women and 90 per cent of pregnant women fasted throughout the period of Ramadan. The metabolic consequences of this fasting were studied by measuring serum glucose, free fatty acid, triglyceride, beta-hydroxybutyrate, alanine, insulin, glucagon and T3 levels at 0700 h and 1900 h in 22 pregnant, 10 lactating and 10 non-pregnant, non-lactating women. Results were also compared with overnight-fasted values obtained outside Ramadan. Values for the lactating women were not significantly different from the non-pregnant, non-lactating controls despite the additional metabolic stress of lactation. Ramadan-fasted (1900 h) glucose values from women in late pregnancy (3.01 +/- 0.11 mmol/l) were significantly lower than all other groups (P less than 0.01) and were 15 per cent (P less than 0.01) lower than overnight-fasted values from similar subjects. Ramadan-fasted free fatty acid and beta-hydroxybutyrate levels were significantly higher (P less than 0.05) and alanine values were significantly lower (P less than 0.05) in late than in early pregnancy. It is concluded that the phenomenon of 'accelerated starvation' occurs when women in late pregnancy fast during Ramadan. The possible consequences of this failure to maintain glucose homoeostasis are discussed with reference to the poor outcome of the actual pregnancies studied.

3-Hydroxybutyric Acid↗

PubMed1983

The relative effectiveness of iron and iron with riboflavin in correcting a microcytic anaemia in men and children in rural Gambia.

Adult males and children between 4 and 12 years in a subsistence farming community in The Gambia were screened for haematological status. 80 men and 80 children with initially poor status were identified and allocated to three treatment groups comprising: a placebo, ferrous sulphate, and ferrous sulphate with riboflavin. Over a period of 6 weeks of supplementation there was a general improvement in haematological status in the two supplemented groups. The inclusion of riboflavin in the supplement enhanced recovery, particularly in those individuals with strikingly low levels of haemoglobin at the outset.

Adolescent↗

PubMed1983

Dietary supplementation of lactating Gambian women. II. Effect on maternal health, nutritional status and biochemistry.

The effect of a high-energy dietary supplement provided under carefully controlled conditions to 130 lactating Gambian women was assessed with respect to changes in maternal health, nutritional status and biochemistry. The supplement resulted in a net increase in energy intake of 723 kcal/d (3.03 MJ/d) and corrected deficits in the intake of protein, riboflavin, vitamin A, vitamin C and calcium. Supplemented women complained of fewer health problems when attending postnatal clinics (P less than 0.001). In particular the incidence of gastrointestinal problems was lower (P less than 0.001). The supplement caused a net body weight gain of only 1.8 kg averaged over a year, and women still lost weight during the farming season. Fasting serum levels of non-esterified fatty acids were increased and of glucose were decreased by the supplement. Plasma concentrations of prolactin, cortisol, insulin and T3 were found to be decreased after supplementation at one or more points during lactation, but growth hormone values remained unchanged. It is suggested that these changes reflect a relaxation from a state of high metabolic efficiency and that much of the additional energy derived from the supplement was simply wasted through a decreased efficiency in the women.

Adult↗

PubMed1983

The effect of vitamin C supplementation on lactating women in Keneba, a West African rural community.

A study of vitamin C requirements was undertaken in the village of Keneba, The Gambia, during the rainy season, when the intake of vitamin C-rich foods is very low. The effect of four supplementary levels of vitamin C (0, 24, 47 and 60 mg/day), together with a milk and biscuit food supplement which provided 34 mg vitamin C/day, was studied for a five-week period. Plasma ascorbate increased from 0.25 to 0.72 mg/dl; buffy coat ascorbate increased from 14.7 to 24.3 micrograms/10(8) cells and breast milk ascorbate increased from 3.4 to 5.5 mg/dl as intake increased from 34 to 103 mg/dl. Breast milk ascorbate approached a plateau at the high intakes. A fasting plasma ascorbate of at least 0.3 mg/dl in 97.5% of the population of lactating women in Keneba would require a daily vitamin C intake of about 117 mg. No differences between vitamin C supplementation levels were observed with respect to changes in plasma iron, total iron-binding capacity or its percentage saturation. Whole blood histamine levels showed a slight downward trend as the vitamin C intake increased.

Adult↗

PubMed1982

Seasonal variations in ascorbic acid status and breast milk ascorbic acid levels in rural Gambian women in relation to dietary intake.

Vitamin C intakes from mangoes and oranges, and plasma and breast milk ascorbic acid concentrations were measured at regular intervals in a cohort of pregnant and lactating women in Keneba and Manduar, two neighbouring rural Gambian villages. Extremely wide seasonal variations in plasma ascorbic acid levels were observed, the peak during the mango season in May and June attaining mean levels of 1.4 mg/dl, while the lowest levels, averaging only 0.2 mg/dl, were observed during the rainy season, during September and October. Parallel, but less pronounced variations were observed in breast milk ascorbate levels. A vitamin-fortified milk and biscuit supplement, given first to the lactating, and later to the pregnant, mothers in Keneba, which provided about 35 mg ascorbic acid per day, failed to produce any major improvement in plasma ascorbic acid levels during the rainy season, although there was some evidence for an improvement in breast milk levels. It is therefore likely that considerably greater intakes are required to maintain satisfactory maternal circulating levels and biochemical status during this critical period.

Ascorbic Acid↗

PubMed1982

Riboflavin status in infants born in rural Gambia, and the effect of a weaning food supplement.

Riboflavin status was measured in infants between birth and two years of age, by the erythrocyte glutathione reductase (NAD(P)H2: glutathione oxidoreductase, EC 1.6.4.2) test on finger-prick blood samples. The infants were living in three rural Gambian villages: Keneba, Manduar and Kanton Kundar; those in Keneba were receiving a weaning food supplement between three and 12 months, which provided 0.15 to 0.20 mg riboflavin per day, in addition to their normal intake from breast milk and locally available weaning foods, which provided 0.13 to 0.21 mg/day over the same age range. On the basis of currently accepted criteria of biochemical normality, the unsupplemented infants were born deficient and, in the absence of a supplement, remained so throughout their first two years of life, with only a minor, short-lived improvement during the first few months. In the supplemented group, however, riboflavin status fell within normal limits for the duration of the supplement, but rapidly deteriorated again once the supplement was withdrawn. It is concluded that infants born to deficient mothers are usually deficient at birth, and remain so throughout suckling and weaning on to locally available foods. The daily requirement, to achieve satisfactory biochemical status, is thus greater than 0.13 to 0.21 mg/day, and probably approaches 0.4 mg/day, for most individuals up to the age of one year.

Child, Preschool↗

PubMed1982

Riboflavin requirements of lactating Gambian women: a controlled supplementation trial.

As part of a study to determine the minimum allowance of riboflavin which is adequate for lactating women in a rural African environment, 60 subjects living in two Gambian villages were given either 2 mg riboflavin or a placebo daily on a double-blind basis for 12 wk. Their riboflavin intake from dietary sources was about 0.5 mg/day. In the supplemented group, the mean activation coefficient (AC) of erythrocyte glutathione reductase fell from 1.62 to 1.19 within 3 wk, and 90% had mean AC's below 1.3 throughout supplementation, whereas the placebo group maintained mean AC's between 1.6 and 1.9. Clinical signs associated with riboflavin deficiency improved more rapidly in the supplemented group; their breast milk riboflavin levels increased, and their infants' AC's were reduced, compared with those of the placebo group. After withdrawal of the supplement, the maternal and infants' AC's rose toward those of the placebo group. Thus a total riboflavin intake of about 2.5 mg/day during lactation is sufficient to maintain normal biochemical status in most Gambian women.

Adult↗

PubMed1982

Breast-milk intake measurement in mixed-fed infants by administration of deuterium oxide to their mothers.

Breast-milk intakes in infants can be estimated from measurements of water turnover rates after the oral administration of small doses of deuterium oxide (2H2O) to the infant or its mother. However, when the former method is used it is not possible to distinguish water intakes from milk and those from other sources. Giving a 2H2O dose to the mother avoids this problem. The theoretical basis for these techniques is examined and useful compromises between the requirements of theory and practice are suggested. Results obtained for breast-milk intakes of Gambian and Papua New Guinean children are used to illustrate the potential value of the procedures.

Administration, Oral↗