Biomedical subjects
K Simmer
Publications and source records attributed to K Simmer.
The effect of dietary fat on the developing brain.
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Transcutaneous application of oil and prevention of essential fatty acid deficiency in preterm infants.
The topical application of vegetable oil was assessed as an alternative means of providing essential fatty acids (EFA) to parentally fed preterm infants who were not receiving lipid. Three infant pairs ranging in gestational age from 26-32 weeks were studied. Safflower oil or safflower oil esters (1 g linoleic acid/kg/day) were applied to available areas daily. All infants rapidly developed biochemical EFA deficiency. The plasma fatty acid profiles were similar in infants with or without topical oil, and all returned to normal once parenteral lipid was introduced. We found no evidence to suggest that the transdermal route is of use in the nutritional management of preterm infants.
Erythrocyte docosahexaenoic acid correlates with the visual response of healthy, term infants.
Recent studies have reported that formula-fed preterm infants score lower on visual and developmental tests relative to breast-fed preterm infants. This phenomenon has been associated with the presence of docosahexaenoic acid (DHA), an omega-3 fatty acid, in breast milk and its absence from infant formula. To investigate the possibility that DHA status of healthy, term infants is also related to neuronal function of the visual pathway, we studied the erythrocyte fatty acid profiles of 16 infants at 22.3 +/- 3.9 wk of age and related these to maturity of the visual pathway as assessed by visual-evoked potentials. Healthy, term infants fed breast milk had better visual-evoked potential acuity (p < 0.05) and higher DHA levels (p < 0.001) than infants who received infant formula as their major energy source. There was a positive correlation between erythrocyte DHA and visual-evoked potential acuity (p < 0.01). The data are preliminary and the long-term effects as yet unknown. However, our results suggest that there is an urgent need to evaluate the dietary fatty acid supply of formula-fed term infants.
Aluminium absorption and antacid therapy in infancy.
The aim of this study was to determine whether infants absorb aluminium from antacid therapy. The study was conducted at Torrens House, a service provided by Child and Adolescent Health Services (CAFHS) for feeding and settling problems. Over an 11 week period, all patients receiving antacid therapy were studied. Patients not receiving antacids but of similar age acted as controls. Plasma and urine levels of aluminium were measured. The 15 infants receiving antacids had higher aluminium levels than the 17 controls (plasma 3.3 +/- 2.2 mumol/L vs 1.5 +/- 1.5 mumol/L, P less than 0.01; urine 25.1 +/- 27.6 mumol/L vs 1.1 +/- 1.8 mumol/L, P less than 0.004). The response was variable with 50% of infants receiving antacids recording plasma aluminium levels previously associated with toxicity in patients with renal failure after chronic exposure to aluminium. We conclude that infants absorb aluminium from antacids and suggest that patients receiving have their plasma levels monitored to identify those at possible risk of toxicity.
Aluminium absorption in infancy.
The use of aluminium-containing medications and aluminium contamination of infant formulae is common. We aimed to determine whether aluminium absorption occurs after antacid ingestion. Plasma and urinary levels of aluminium were measured before and after antacid therapy in seven infants whose mean gestational age was 36 +/- 2 weeks and postnatal age 11 +/- 5 days. Antacid therapy (400-800 mumol aluminium) was given with feeds for 2 days. Plasma aluminium levels increased and reached toxic levels (0.64 +/- 0.33 mumol/L vs 3.48 +/- 2.86 mumol/L, P = 0.029). Urinary aluminium: creatinine ratio also increased. These results demonstrate that infants absorb aluminium from antacids and raise the concern of aluminium toxicity.
Delivery of vitamin A from parenteral nutrition solutions in neonates.
The delivery of Vitamin A from parenteral nutrition may be suboptimal. To investigate this sample solutions were prepared and Vitamins A and E concentrations from the solution bags and the efflux from the lines were measured over a 24 h period. The results show that mean Vitamin A levels in the solution bags declined from a range of 57-66% to 17% of expected over 24 h and at the efflux of the lines from a range of 13-29% to 4% of expected, giving a calculated delivery of 10% of expected. There is no improvement with light protection or an ethylene vinyl acetate system. Mixing the vitamin preparation in lipid showed less decline (from 92 to 70% of expected over 24 h), but the delivery was variable. When vitamins were added to a lipid-dextrose-amino acid solution, there was minimal loss from the solution bag and line with a calculated delivery of 94% of expected. The delivery of Vitamin E from all systems was constant with a mean calculated delivery of 74% of expected. It was concluded that the mixing of multivitamins in dextrose-amino acid-electrolyte solutions results in poor delivery of Vitamin A and this is improved by mixing lipid solution. This is important in preterm infants who are prone to become Vitamin A deficient.
A double-blind trial of zinc supplementation in pregnancy.
A double-blind randomised trial of oral zinc supplementation was carried out during the last two trimesters of pregnancy. Fifty-six women at risk of delivering a small-for-gestational-age baby received either zinc supplement (22.5 mg daily) or placebo. Twenty-nine of the women were compliant. Zinc significantly reduced the incidence of intrauterine growth retardation, and most measured indices of labour and fetal health were better in the supplemented group. Larger studies are now needed to confirm a role for selective zinc supplementation in at-risk pregnancies.
Breast milk zinc and copper concentrations in Bangladesh.
Breast-fed infants in Bangladeshi villages were weighed at 1, 2, 6, 9 and 12 months. The concentrations of zinc and copper in the breast milk were measured and the daily intake of these elements calculated. Breast milk Zn concentration decreased over the year but was comparable with that found in developed countries. The calculated daily intake decreased from 17.7 to 8.0 mumol (10-30% of recommended dietary allowances (RDA); National Academy of Sciences, 1980). Breast milk Cu concentration also fell over the year and was lower than that reported from developed countries. Calculated daily Cu intake was 1.95-2.63 mumol (RDA 7.81-15.63 mumol). Deficiencies of trace elements may therefore be a problem in poorly nourished communities where breast feeding is continued for several years with only small amounts of additional food. Breast milk may not be adequate as the only source of infant nutrition after the first few months of life in Bangladesh.
Aluminum concentrations in infant formulae.
The aluminum concentrations in breast milk and in 25 commercially available infant formulae were measured. The mean concentration in breast milk was 49 micrograms/L while concentrations in most of the humanized formulae were less than 500 micrograms/L. Higher concentrations were found in Nan, Prem Enfamil and the three soya formulae. We suggest that all formulae have the potential to be contaminated with aluminium, and to varying degrees in different batches. Until it is known whether aluminium toxicity occurs in normal infants fed these formulae, it seems reasonable to expect manufacturers to routinely measure aluminium and keep aluminium contamination to a minimum. This may be especially important for formula fed to infants with compromised gastrointestinal and renal systems.
Neonatal hydrometrocolpos.
A neonate with persistence of the urogenital sinus, double vaginae and hydrometrocolpos, in association with an anterior perineal anus, ambiguous genitalia and a ventricular septal defect, is described. Abdominal ultrasound led to an early diagnosis which prevented morbidity and mortality from renal failure and unnecessary laparotomy. Drainage was achieved by a perineal procedure.
Nutritional rehabilitation in Bangladesh--the importance of zinc.
Our aim was to investigate whether zinc deficiency becomes apparent during nutritional rehabilitation and limits the rate of weight gain. Twenty-five severely malnourished children, who were admitted to the Children's Nutrition Unit in Bangladesh, were alternately allocated to two groups. Their mean dietary Zn intake was 3.7 mg/d and mean caloric intake greater than 150 kcal.kg-1.d-1; one group received a daily Zn supplement of 50 mg for 2 wk. During the first week, weight gain was similar in the two groups, but during the second week, weight gain was 73% more in the Zn-supplemented group (8.83 +/- 1.56 vs 5.09 +/- 1.62 g.kg-1.d-1). The 95% confidence limits were 0.88 less to 8.36 g.kg-1.d-1 more gain in children receiving Zn supplements. The results strongly suggest that Zn supplements are beneficial to severely malnourished children during nutritional rehabilitation. Polymorphonuclear (PMN) cell Zn increased in the group receiving Zn supplements (p less than 0.001), confirming that the Zn content of PMN cells reflects available Zn.
Hypogammaglobulinemia and depressed natural killer cell cytotoxicity in a patient with Pneumocystis carinii infection.
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Copper and very low birthweight babies.
Serum concentrations of copper and ceruloplasmin were measured in 24 very low birthweight babies. They were high in those weighing less than 1000 g, and critically ill or receiving intravenous nutrition, and normal in those with bone disease, neutropenia, or oedema. Care is needed to maintain adequate concentrations without toxicity.
Are iron-folate supplements harmful?
Zinc absorption during pregnancy was measured before and 24 h after 2 wk of daily, oral, iron-folate supplements. Absorption was reduced 24 h after iron-folate, which suggests a mucosal rather than a luminal effect. Also, zinc absorption in 10 healthy volunteers was reduced by folate supplements alone. Therefore, routine iron and folate supplementation may both have deleterious effects on zinc metabolism, especially during pregnancy when iron-folate supplements are often prescribed despite adequate dietary intakes of iron and folate but not of zinc.
Zinc status in polycythaemia.
Zinc and iron status have been measured in three groups of polycythaemic patients managed by venesection: polycythaemia rubra vera, secondary polycythaemia and idiopathic erythrocytosis. Zinc status was assessed from the concentration of zinc in polymorphonuclear cells (PMN) and plasma. The mean PMN zinc value was lower than that of age-matched controls (polycythaemics 57.5 +/- 2.3 micrograms/10(10) PMN, n = 26; controls 68.9 +/- 5.2 micrograms/10(10) PMN, n = 9; means +/- SEM, p less than 0.05). The difference was most marked in polycythaemia rubra vera; the patients were iron-deficient. The reduced PMN zinc levels may indicate that polycythaemic patients managed by repeated venesection are zinc-deficient. This may contribute to some nonspecific symptoms of polycythaemia and to recurrent infections in the hypoxic patients.
Maternal nutrition and intrauterine growth retardation.
Nutritional factors associated with intrauterine growth retardation (IUGR) were studied in 118 mothers, from an inner London population, 24-48 h after delivery. Lower socio-economic status, smoking and, in the diet, only a low dietary intake of zinc were significantly associated with IUGR. It is suggested that women at risk of delivering babies small-for-gestational-age might benefit from an increased zinc intake.
Do pregnant women need zinc supplements?
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