Browsing by Author "Heese, H de V"

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    Genetic and environmental influences on cord blood atopic markers and on atopic sensitisation in infancy
    (1988) Haus, Matthias; Heese, H de V
    HISTORICAL PERSPECTIVE: It has recently been shown that intensive prophylactic dietary and environmental control measures during early infancy may reduce the incidence and/or postpone the onset of atopic disease. In order to institute this prophylactic regime, early identification of the infants genetically "at risk" for atopic disease is essential, since sensitisation begins at birth, or even during intra-uterine life. European and Scandinavian studies have shown that a raised concentration of cord blood serum immunoglobulin E (CBsIgE) is an excellent predictive marker for the subsequent development of atopic disease. Other potential predictive atopic markers such as cord blood eosinophils, platelets and anti-cow's milk serum IgG have also been suggested as having possible predictive relevance for newborns in terms of the development of subsequent atopic disease. PROBLEM DEFINITION: Most of the work in this field has been done on Caucasian neonates, in Westernised, First World countries. In South Africa, it has been shown that the Black adult ethnic group has serum immunoglobulin E concentrations (sIgE) which are significantly higher than that found in the South African White adult ethnic group. Furthermore, it has been suggested that the elevated sIgE in the adult Blacks may be raised independently of allergic disease. It is, therefore, important to ascertain whether this elevation of sIgE in Black South African adults is evident already at birth in the cord blood sera of Black South African newborns. If so, it is imperative to ascertain whether any such elevation is reflective of a high genetic load for atopy in these Black newborns, and furthermore whether these Black newborns are consequently "high-risk" for the development of subsequent atopic disease, as has been previously reported in the literature for White newborns. Arising from an awareness of these specific South African problems, the following hypothesis was developed. HYPOTHESIS: The hypothesis states that: "Black South African newborns without an atopic family history (aFH) have significantly higher CBslgE values than similar White and Mixed newborns. An aFH does not influence the CBsIgE values in the Black newborns, as it does in the White and Mixed newborns. The CBsIgE values in Black newborns are not, furthermore, predictive for the development of subsequent atopy in infancy, as they are in the other ethnic groups". A description of the three South African ethnic groups considered in this study is provided in Section IV, (Pg. 74). AIMS OF THE STUDY: The aims of the study were three-fold: 1. To test the hypothesis. 2. To assess the relevance of alternative cord blood markers (eosinophils, platelets and anti-cow's milk serum IgG) as predictive atopic markers in each of the three ethnic groups. 3. To provide epidemiological information with regard to genetic and environmental influences on CBslgE, cord blood total eosinophil counts (CBTEC's) cord blood platelet counts (CBPlC's) and cord blood anti-cow's milk serum IgG concentrations (CBacmlgG).
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    The prevalence of asthma in urban and rural Black children : an epidemiological survey
    (1979) Van Niekerk, Christoffel Hendrik; Heese, H de V
    This survey was undertaken: 1. to provide accurate information on the prevalence rates of asthma in Xhosa children living in an urban westernised community, Guguletu, Cape Town and in a rural traditional community, Tsolo District, Republic of Transkei; 2. to compare the findings of this survey with studies done elsewhere in the world on prevalence rates of asthma among children; and 3. to evaluate and correlate factors that may influence these rates. To acquire the above, it was necessary 1. to obtain information on the characteristics and socio-economic status of the family of each child studied; 2. to obtain information on every child relating to exposure to allergens in his immediate home environment; 3. to obtain information on the dietary pattern of every child during infancy and currently; 4. to identify the asthmatic children by subjecting every child to an appropriate exercise stimulus for detection of exercise-induced asthma judged by pulmonary function tests; 5. to conduct a clinical examination of the children. and skinfold thickness was also measured; Height, weight 6. to conduct prick skin testing to assess specific skin sensitivity to common allergens; 7. to conduct laboratory investigations relating to the allergic-immune status of the children; 8. arising out of these findings to relate the prevalence rates of asthma in the 2 samples and to suggest factors influencing the rates.
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    A study of iron nutrition and immunity in infancy
    (1988) Power, Harold Michael; Heese, H de V
    Motivation and study design: Iron deficiency is a common condition in infancy, particularly in lower socio-economic groups. In Cape Town it remains a problem in spite of public health measures taken against it: a recent survey found a prevalence of iron deficiency anaemia of 34% in healthy 1-year old term infants who had ready access to a municipal health clinic where iron fortified milk formula is sold at subsidized prices. The consequences of iron deficiency extend beyond anaemia- to involve all organ systems including the immune system. Since Helen Mackay's report in 1928 of a striking decrease in incidents of infection in infants treated with iron, clinicians have assumed that iron deficiency predisposes to infection. Despite a sound theoretical basis for this belief, the clinical evidence for the assumption is poor as studies to date have displayed methodological deficiencies. On the other hand, iron is also essential for the growth of micro-organisms. As such, supplemental iron may predispose to infection. Indeed, there is much laboratory and clinical evidence to show that excess iron can result in the recrudescence of quiescent infections and increase the virulence of newly acquired infections. Thus, the competition between host and parasite may sometimes hinge on the relative availability of iron and it has been speculated that excess iron in infant milk formula may increase susceptibility to infectious diarrhoeal disease. The problem addressed by this thesis was to determine the utility of increasing the level of iron fortification of infant milk formula. Three questions were posed: Does increasing the level of iron fortification of conventional infant milk formula improve the iron nutrition of normal infants fed on the formula? Does increased iron fortification of infant milk formula alter immunity as reflected by incidence of infection and laboratory tests of immune function? Are there any handful effects of increasing the quantity of iron in conventional infant milk formula? A double blind randomized trial was carried out in 1983 and 1984 to answer these questions. A group of 149 healthy, well-nourished infants from a lower socio-economic community of so called Cape Coloureds were followed from the age of 3 months to 1 year. Half of the infants, the Control group, were given a commercially available infant milk formula (Lactogen Full Protein) which has 8.3 mg Fe/ 100 g formula and 37 mg ascorbic acid/ 100 g. The other half of subjects, the Test group, were given the same milk formula but fortified with iron to a concentration of 40 mg Fe/ 100 g. The children were examined every 3 or 4 weeks and any infection or history of infection was noted. Laboratory tests were done at the start of the trial and again on completion. During the trial, laboratory tests were performed only if clinically indicated. The tests included full blood count and differential analysis, red cell zinc protoporphyrin, plasma ferritin, plasma and hair zinc and lymphocyte subtyping with monoclonal antibodies. Within each group, half of the infants were randomly selected for assay of neutrophil bactericidal activity. The other half were assayed for lymphocyte blastogenic response to stimulation with phytohaemagglutinin. Tests of delayed cutaneous hypersensitivity to Candida antigen and PPD were done and all children and their mothers had antibodies to tetanus and polio determined. Results: 74 infants in the Control group started the trial and 62 completed it. In the Test group, 75 infants began and 70 completed the study. Intake of milk and solid foods was not quantified, but the ages of weaning and of introduction of new foods were determined. The Control and Test groups did not differ significantly on any test item. The mean age of completion of weaning was 3.60 months for the Control group and 4.04 months for the Test group. The Control group was first given meat or fish at a mean age of 5.19 months; the Test. group had meat or fish introduced to their diets at a mean age of 4.36 months. These differences were not statistically significant. The children in the Control group were lighter and shorter than the Test group at the end of the year. Mean standard deviation scores for weight were 0.23 and 0.48 respectively (P = 20%), while for length the SD scores were -0.13 and 0.06 (P = 20%).