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Biomedical subjects

R G Hendrickse

Publications and source records attributed to R G Hendrickse.

At least 55 records · Page 3Linked to original sources

The influence of aflatoxins on child health in the tropics with particular reference to kwashiorkor.

Aflatoxins are common environmental hazards in all the underdeveloped countries of the tropics where they commonly contaminate food. They are toxic to most species of animals and are among the most powerful carcinogenic agents known. The liver is the principal target for toxicity. Metabolic derangements caused by aflatoxins include depression of protein and enzyme synthesis, disorder of lipid metabolism and immunological suppression. The aetiology and pathogenesis of kwashiorkor remains somewhat obscure. Similarities in the geographical and climatic prevalence of kwashiorkor and aflatoxins and similarities in the metabolic derangements caused by aflatoxins and those observed in kwashiorkor, prompted investigation of the relationship between aflatoxin and kwashiorkor in the Sudan and elsewhere in Africa. Analysis of foods from markets and in homes revealed widespread aflatoxin contamination. Aflatoxins were found more frequently and at higher concentrations in the serum of children with kwashiorkor than in those with other types of malnutrition or in normal children. Aflatoxicol, a metabolite of aflatoxin B1 was detected in serum in kwashiorkor and marasmic kwashiorkor but not in normally nourished children and only once in marasmus. Autopsy liver samples from West and Southern Africa have shown aflatoxins in all cases of kwashiorkor but not in marasmus. These findings establish relationships between aflatoxin and kwashiorkor the nature of which remains obscure but includes the possibility of a causal association.

Aflatoxins↗

Aflatoxins in human breast milk.

Breast milk from 99 Sudanese mothers was analysed for aflatoxins. Aflatoxins M1 and/or M2 were detected in 37 of the milks. No other aflatoxin was detected. M1 occurred alone in 13 milks, (mean 19.0 pg/ml), M2 in 11 milks (mean 12.2 pg/ml), and in 13 samples both M1 and M2 were detected. There appeared to be a linear relationship between M1 and M2 where both were excreted. No aflatoxin was detected in subcutaneous abdominal wall fat removed during Caesarian section from 15 women, but was present in three out of 14 bloods taken during anaesthesia. The presence of aflatoxins in mothers' milk showed no correlation with duration of lactation, the infants' nutrition, presence of aflatoxin in mothers' blood, or the infant's blood and urine. It is concluded that some Sudanese women excrete aflatoxins in breast-milk at levels similar to or higher than those considered safe in animal milk, for human consumption.

Adipose Tissue↗

Iron and infection in infancy--report on field studies in Papua New Guinea: 1. Demographic description and pilot surveys.

Madang district was selected for a longitudinal study of the effects of iron prophylaxis on infectious morbidity in infancy and the topography, climate, domicile, ethnology, demography, disease patterns, nutrition and health services of the district are described. The area has a tropical, humid climate and a mixed economy. Pneumonia was the main killing disease at all ages, and malaria was endemic. A base hospital and well organized maternal and child health services ensured that morbidity surveillance would be optimal. Pilot haematological surveys confirmed a high incidence of anaemia in infancy. Mean haemoglobin between nine and 52 weeks of age was 8.6 g/dl. Results suggested that malaria and iron deficiency were important causes of this anaemia.

Age Factors↗

Iron and infection in infancy--report on field studies in Papua New Guinea: II. Protocol and description of study cohort.

The protocol for a prospective, randomized, double-blind, placebo controlled trial of iron prophylaxis in infants is described. Specific design points discussed include (i) control and "blind", (ii) dose, preparation and age of administration of iron, (iii) standardization of morbidity recording, (iv) data analysis and (v) ethics. The study cohort at birth is described and rationale for exclusions and reasons for withdrawals are discussed. An initial descriptive comparison is made of treatment and control groups entering the trial at two months of age.

Age Factors↗

Aflatoxins and kwashiorkor. Epidemiology and clinical studies in Sudanese children and findings in autopsy liver samples from Nigeria and South Africa.

The aetiology and pathogenesis of kwashiorkor remains obscure. Clinical and epidemiological studies are in progress in Sudan to determine whether aflatoxins play a role in the pathogenesis of kwashiorkor. Local foods are screened for their aflatoxin content and children with kwashiorkor and age and sex matched children with marasmus and with normal nutrition are being investigated for aflatoxins in their blood and urine. Autopsy liver samples of children with kwashiorkor and other nutritional disorders in Nigeria and South Africa have been examined for their aflatoxin content. Aflatoxins are detected using two dimensional thin layer chromatography and high performance liquid chromatography. Results to date on over 350 children studied show that aflatoxins occur more frequently and at higher concentrations in the sera of children with kwashiorkor than in children with marasmus or in normal children. Urinary excretion of aflatoxins in kwashiorkor appears to be less than in other groups. In the autopsy liver samples, aflatoxins have been detected in all kwashiorkor livers but not in livers from marasmic children. These findings seem to implicate aflatoxins in the pathogenesis of kwashiorkor. If this is confirmed it would have very wide implications for the management and prevention of kwashiorkor.

Aflatoxins↗

Aflatoxins and kwashiorkor: a study in Sudanese children.

Blood and urine samples from 252 Sudanese children were investigated for their aflatoxin content by high-performance liquid chromatography. The children comprised 44 with kwashiorkor, 32 with marasmic kwashiorkor, 70 with marasmus, and 106 age-matched, normally nourished controls. Aflatoxins were detected more often and at higher concentrations in sera from children with kwashiorkor than in the other malnourished and control groups. Aflatoxicol, a metabolite of aflatoxins B1 and B2, was detected in the sera of children with kwashiorkor and marasmic kwashiorkor but not in the controls and only once in a marasmic child. The difference between children with kwashiorkor or marasmic kwashiorkor and those in the control or marasmus groups was significant. Urinary aflatoxin was most often detected in children with kwashiorkor but their mean concentration was lower than in the other groups. Aflatoxicol was not detected in urine in any group. These findings suggest either that the children with kwashiorkor have a greater exposure to aflatoxins or that their ability to transport and excrete aflatoxins is impaired by the metabolic derangements associated with kwashiorkor. The presence of aflatoxicol in the sera of children with kwashiorkor but not in the others suggests a difference in metabolism between the two groups. Further studies are needed, and measurement of aflatoxins in the food eaten by these children is already underway.

Aflatoxins↗

Aflatoxins in the livers of children with kwashiorkor.

Autopsy liver specimens from Nigeria and South Africa obtained from three kwashiorkors, three marasmic-kwashiorkors and one marasmic child were analysed for the presence of aflatoxins using both high performance liquid chromatography and thin layer chromatography. Significant levels of aflatoxin B1 were found in the livers of the three kwashiorkor children. Aflatoxicol was detected in the liver of one marasmic-kwashiorkor and a small quantity of aflatoxin M1 in the liver of another. No aflatoxins were found in the livers of the third marasmic-kwashiorkor or the marasmic child. These findings extend recent clinical observations that indicate an association between aflatoxins and kwashiorkor.

Aflatoxin B1↗

Loperamide in the treatment of acute gastroenteritis in early childhood. Report of a two centre, double-blind, controlled clinical trial.

Loperamide at a dose of 0 . 2 mg/kg/day was compared with placebo in the treatment of acute infantile gastro-enteritis in hospital-based double-blind clinical trials carried out in parallel in Liverpool, England and Benghazi, Libya. Fifty patients aged one month to four years entered the study in each centre. Rotavirus was the predominant pathogen isolated in both centres. Pathogenic Escherichia coli was cultured from five children in the Liverpool study only. No statistically significant differences were observed in the duration of diarrhoea, length of stay in hospital or weight gain during the first 48 h after admission, between loperamide and placebo groups in either centre. Loperamide, in the dosage used in this study, appears to have no significant effect on the course of acute gastro-enteritis in early childhood. The possibility that these results may reflect specifically on rotavirus infection is discussed. No toxic effects of loperamide were observed.

Body Weight↗

Salmonella osteomyelitis in childhood. A report of 63 cases seen in Nigerian children of whom 57 had sickle cell anaemia.

A review of 63 Nigerian children with salmonella osteomyelitis showed that in all but 2 of them the disease occurred in association with HbS either in the homozygous state (57 patients) or in heterozygous combination with other haemoglobins (4 patients). Osteomyelitis was most prevalent during the first 2 years of life, and boys were more often affected than girls. In the majority, multiple sites were involved and lesions were usually bilateral and often symmetrical. Salmonella sp. was isolated from blood or pus, or both, in all patients. In some patients additional pathogens were also isolated from blood or pus. Clinical presentation was variable. In many patients the illness was slight and they were treated entirely as outpatients, but serious toxaemia, severe bone lesions with pathological fractures, and chronic suppuration occurred in others. Most patients responded well to chloramphenicol and conservative management. There were 4 deaths. 17 patients recovered with sequelae. It is suggested that the peculiar susceptibility of patients with sickle cell anaemia to salmonella osteomyelitis is due to spread of salmonella from the intestine facilitated by devitalisation of gut caused by intravascular sickling, and that infarcts in bone became infected either by transient bacteraemia or by activation of dormant foci of salmonella in bone marrow when tissues are devitalised. It is further suggested that immunological defects in sicklers may impair host response to infection, while haemolysis and hepatic dysfunction, both of which occur in sickle cell anaemia, favour propagation of salmonellae.

Age Factors↗

Quartan malarial nephrotic syndrome in children.

Quartan malarial infection causes an immune complex nephritis in some individuals, which, once established, is sustained by mechanisms not yet fully explained, but which probably involve autoimmune processes. The presenting clinical and biochemical findings of the quartan malarial nephrotic syndrome are similar to those classically described for the nephrotic syndrome in childhood, but the renal pathology seen on light, electron, and immunofluorescent microscopy show striking differences and distinctive features. The disease tends to pursue a chronic course and in most patients is nonresponsive to treatment with antimalarial drugs, prednisolone, and immunosuppresive drugs. The overall prognosis is poor, with most patients developing hypertension and evidence of renal failure within 3 to 5 years of onset.

Antigen-Antibody Complex↗

A controlled trial of cyclophosphamide and azathioprine in Nigerian children with the nephrotic syndrome and poorly selective proteinuria.

In a controlled trial, symptomatic treatment alone, or 12 weeks of cyclophosphamide or azathioprine were compared in Nigerian children with nephrotic syndrome (mainly quartan malarial nephropathy) and poorly selective proteinuria. Full remission in 2 patients in each of the two groups treated with drugs, and diminution of proteinuria in most patients in the cyclophosphamide group showed possible evidence of benefit. Infections during treatment were significantly more common in the drug-treated groups but were controllable. Mortality from renal failure in the 2nd year after treatment was significantly greater in the azathioprine-treated group than in the other two, suggesting that the drug may have exacerbated the nephritis. The 5-year survival rate was similar in the cyclophosphamide and the control group.

Azathioprine↗