Nutritional amblyopia in a 32-year-ld male [abstract]

A 32-year-old Caucasian man presented with a 6 month history of gradual visual loss. He lived alone and consumed large quantities of alcohol. In addition, he smoked heavily and had only one meal per day. Examination revealed poor visual acuities bilaterally, with normal looking optic discs and retina. An MRI brain scan was normal. Visual evoked potentials showed small P100 responses. His mean corpuscular volume was elevated as was the gammaglutamyl transpeptidase. The patient was started on high dose vitamin B. His visual acuities are improving. (AU)

Antioxidant status of malnourished children

Free radicals, by virtue of their reactive nature, could account for the clinical features of kwashiorkor. These chemical species are produced in excess only after antioxidant defences fall. The possibility of this situation occuring in children with kwashiorkor was therefore investigated. Whole blood glutathione (GSH) levels were significantly decreased in children with kwashiorkor and marasmic-kwashiorkor. This indicates the presence of an overwhelming pro-oxidant stress. At a GSH level of 1.90 moles/Irbc (6.80 æmoles/gHb) oedema could be diagnosed with a sensitivity, specificity and positive accuracy of greater than 90 percent. GSH correlated inversely with the degree of oedema (r = -0.69). In children with maramus GSH was normal. Erythrocyte concentrations of NADPtot were normal in all children. The percentage of this nucleotide in the oxidised form ( percentNADP+/NADPtot) was normal in children with maramus, but abnormally elevated in oedematous children. This means that there is an acute change in the cellular redox in oedematous children, and implies that the cellular environment is oxidising. The activities of erythrocyte glutathione reductase, glutathione S-transferase (GST) and glyoxalase I were either normal or markedly elevated. Riboflavin status was poor. The end products of detoxification by GST, urinary mercapturic acids (UMCA), were between 3 and 5 times higher than normal. There were no intergroup differences. This suggests that the body's burden of toxins is significantly increased. During recovery from malnutrition, children with maramus showed a rapid restoration of normal antioxidant status, whereas those with oedematous malnutrition did so only after loss of oedema. This was followed by progressive, and unexpected, deterioration in antioxidant status: plasma vit. E and GSH levels decreased, and UMCA levels remained elevated. It was reasoned that the high PUFA content (60 percent )of the recovery diet may be a source of oxidative stress. In a second study the recovery diet contained an oil (coconut), rich in saturated fatty acids. On this diet children maintained normal levels of vit.E and GSH, and UMCA decreased significantly. This confirmed the high PUFA diet as a source of oxidative stress. Collectively, these data suggest that free radicals are involved in the aetiology and pathogenesis of kwashiorkor. It is recommended that: (1) whole blood levels of GSH be used in the diagnosis of oedematous malnutrition, and (2) coconut oil and antioxidants be used to treat malnourished children (AU)

Erythrocyte clutathione reductase activity and riboflavin status in severely malnourished children - abstract

Erythrocyte glutathione reductase (EGR), cofactor is riboflavin (vit B2), functions together with glucose 6-phosphate dehydrogenase to maintain cellular levels of glutathione and thus the integrity of the erythrocyte. The compromised antioxidant status of severely malnourished children along with increased exposure to metabolic stress led us to postulate that EGR activity might be increased in malnutrition as a compensatory response to oxidative stress. We therefore measured EGR activity in 49 severly malnourished children on admission and again in 35 of these children at discharge. Erythocyte glutathione-reductase-activation-coefficient (ERGAC), an index of riboflavin status, was also assessed. Twenty-two healthy children served as controls (C). The malnourished group had significantly higher EGR activity (8.34 ñ 0.31 U/g Hb; mean ñ SEM) than the control group (6.63 ñ 0.23 U/g Hb). On admission, children with marasmus (M) had significantly higher EGR activities (8.95 ñ .046 U/g Hb) than children with marasmic kwashiorkor (MK: 8.08 ñ 0.67 U/g Hb) or kwashiorkor (K: 7.66 ñ 0.53 U/g Hb). At discharge, high levels of EGR were maintained in all groups. However, the kwashiorkor group showed a significant increase up to (10.37 + 0.41 U/g Hb). An EGRAC > 1.30 indicates riboflavin deficiency. Forty per cent of the controls as well as 50 percent of the malnourished children were deficient in riboflavin supplementation of the malnourished groups, the EGRAC fell to normal levels. We concluded (1) that EGR activity is increased in severly malnourished children; this may be as a result of increased metabolic stress, and (2) the riboflavine status of malnourished children improved significantly during their recovery (AU)

An examination of nutrient intakes in a middle income area of Jamaica

The aim of this study was to gain some information on food consumption patterns of middle income families. A dietary and budget survey was carried out in 15 households in an urban middle-income area of Jamaica. All the households had children aged six months to three years. Weights and heights were recorded at the beginning and at the end of the survey. The results showed that less than 50 percent of the households had insufficient energy intakes, whilst protein intakes were exceptionally high. The children showed similar levels of high protein intakes, but 73 percent had inadequate energy intakes. The majority of children had weights and heights which compared favourably with the Boston standard. The diets of the children consisted mainly of milk and fruits with varying amounts of chicken, rice, milo, irish potatoes and bread. Eight children were fed from the family pot and these children were all over 12 months old. The diet of the households was quite varied with some 42 food items being eaten. However, the foods which provided best value for money, canned meat and fish, tripe, counter cornmeal, oats, peanut butter, gungo peas, were very rarely or never eaten. The average percentage of income spent on food was 27 percent, with families of income higher than the mean, that is, $187.00 per week, spending a smaller percentage on food than families with an income lower than the mean income. Mean family size was 4.5 members (Summary)

Hypoglycin toxicity in rats. II. Modification by riboflavin of mitochondrial changes in liver

Hypoglycin (L-O-amino-á-methylenecyclopropanepropionic acid) is a toxin found in the unripe fruit of the ackee, and associated with Jamaican "vomiting sickness." It produces profound hypoglycemia due to interference with long-chain fatty acid oxidation and gluconeogenesis, and is accompanied by mitochondrial swelling in rat hepatocytes. The hypoglycemic effect may be prevented or reversed by riboflavin. The present study indicates that mitochondrial swelling is reduced in rats given riboflavin prior to hypoglycin, compared with rats given hypoglycin alone. Riboflavin appears less effective if given 10 minutes after hypoglycin.(AU)

Teratogenicity of hypoglycin-A: some morphological and biochemical aspects

Hypoglycin-A is a toxic, non-proteinogenic amino acid of considerable biochemical interest. It is obtained fron the fruit of Blighia sapida K., and is the causative factor of the Jamaican "vomiting sickness". The toxicity of hypoglycin-A is attributed to the formation of a metabolic methylenecycclopropaneacetic acid which inhibits the oxidation of long-chain fatty acids. Hypoglycin-A induced in pregnant rats a significantly high incidence of congenital abnormalities and reabsorption. It did not reduce the fertility in mice, malformations were absent and only a small increase in reabsorption sites was observed after the adminstration of large doses. Hypoglycin-A administered to pregnant rabbits resulted in a high incidence of foetal reabsorption and overall stunting. Injected into the yolk sac of 24 and 48 hour chick embryos, hypoglycin-A was not teratogenic. Leucine, administered to pregnant rats simutaneously with hypoglycin-A, afforded no protection against the teratogenic action of hypoglycin-A. Leucine was shown to be highly teratogenic and exaggerated the teratogenicity of riboflavin and hypoglycin-A to pregnant rats the occurrence of congenital abnormalities. Inhibition of long-chain fatty acid oxidation may represent a basic cellular mechanism involved in the teratogenicity of hypoglycin-A, because of its influence on oxidative phosphorylation and the electron transport system. Reversal of the hypoglycin-induced teratogenic effects by riboflavin, suggests that inhibition of the acyl dehydrogenase flavin-dependent-oxidation reaction, occurring during the degradation of fatty acids, is the site of action of hypoglycin-A (AU)

Application of a conversion factor in a photodecomposition fluorimetric method for determination of riboflavine in urine

The rates of photodecomposition of riboflavine in extracts of standard solutions were determined fluriometrically and related to the concentrations of riboflavine in these solutions. A factor was derived from each standard solution. The average of these factors was applied to convert the rate of photodecomposition of extract of urine to urine riboflavine concentration. Results by this method were closely similar to those by the internal standard method in normal as well as grossly pathological urines. The specificity and accuracy of the method were examined. Nutritional survey with casual urine riboflavine determinations related to creatinine excretion and saturation tests gave results appropriate for the region studied, as demonstrated by previous survey. Six-hour urine riboflavine excretion following saturation tests in 20 adults was 12-48, mean 28+-10.2 (S.D.) ug. percent of test-dose