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Biomedical subjects

A Orren

Publications and source records attributed to A Orren.

45 records · Page 3Linked to original sources
PubMed1983

Functional identification of serum complement components following electrophoresis in polyacrylamide gels containing sodium dodecyl sulphate.

A method is described for detecting the active complement components C6 and C7 after polyacrylamide gel electrophoresis (PAGE) of whole serum in the presence of sodium dodecyl sulphate (SDS). The method involves the removal of SDS by washing with non-ionic detergent followed by the application of an erythrocyte/agarose gel to detect haemolytic activity. Two forms of human C6 with apparent molecular weights of approximately 121,000 daltons and 114,000 daltons were observed. Major activity resided in the 121,000 dalton species. The 2 forms of human C6 were not related to known genetic polymorphisms for this component. Analysis of sera from different animal species showed that not all possessed the 2 forms of C6 and that there were interspecies differences in C6 molecular weights. These are most marked in the case of human and murine C6; the major form of murine C6 had a molecular weight approximately 20,000 daltons less than the major human form. One form of human C7 with an apparent molecular weight of 104,000 daltons was seen. The molecular weights of C7 from the various animal sera tested did not differ significantly from this. Studies with reducing agents and metabolic inhibitors showed that both C6 and C7 required intact disulphide bonds and sulphydral groups for functional activity.

Animals↗
PubMed1981

Increased susceptibility to herpes simplex virus infections in children with acute measles.

Children with measles treated either in hospital or as outpatients were examined for clinical or laboratory evidence of oropharyngeal herpes simplex virus (HSV) infection. HSV was isolated from 43% of the hospitalized children and 37% of the outpatient children and an additional 9% of the hospitalized group had lesions without the virus being isolated. The incidence of both HSV isolation and clinical lesions in infected children was significantly greater in children hospitalized for measles than in a control group of children hospitalized for tuberculosis. Data from the outpatient group strongly suggest that malnourished children with measles are particularly susceptible to HSV infection. The immunosuppressed state of the children with acute measles was demonstrated by impaired lymphocyte transformation responses to phytohemagglutinin and the inability of their serum to support normal transformation responses by lymphocytes from normal individuals. However the extent of this immunosuppression was unrelated to the susceptibility of the children to HSV infection.

Child, Preschool↗
PubMed1979

Serum complement concentrations, nutritional status and the outcome of measles and measles pneumonia.

A prospective study of children with measles has shown a significant association between malnutrition and a poor prognosis. Levels of a number of complement components bore no relationship to the severity of the disease or to its prognosis. Some of the children with acute measles had depressed serum concentrations of factor D, Clq or C3, but complement deficiency does not appear to be implicated in the heightened susceptibility to secondary bacterial and viral infection so commonly found after acute measles.

Body Weight↗
PubMed1977

Studies on Bermuda grass pollen allergens.

Two allergens, BGP-1 and BGP-2, were identified in crude Bermuda grass pollen extract. BGP-1 was a major allergen and elicited a skin reaction in all subjects sensitive to the crude extract, whereas BGP-2 was a minor allergen and elicited a reaction in only 75% of such subjects. Calibrated column chromatography was used to determine the molecular weights and Stokes radii of the allergens. For BGP-1 they were 30 000 daltons and 24,3 X 10(-8) cm respectively and for BGP-2 they were 14 000 daltons and 18,1 X 10(-8) respectively. The sedimentation coefficient (S20,w) of BGP-1 on sucrose density gradient ultracentrifugation was 3,1 and on iso-electric focusing its iso-electric point was found to be pH 5,4. The reason why only certain individuals sensitive to BGP-1 are sensitive to BGP-2 is discussed. It is possible that the former is a dimer of the latter.

Centrifugation, Density Gradient↗
PubMed1975

Serum immunoglobin E concentrations of allergic patients and blood donors. Influence of allergy, sex and race on IgE values.

Serum IgE concentrations were measured in allergic subjects attending the Allergy Clinic at Groote Schuur Hospital, Cape Town. White and Cape Coloured clinic subjects had serum IgE concentrations which were significantly higher than those found in comparable groups of either non-allergic blood donors or blood donors with symptoms of allergy; in Blacks these differences were not apparent. Although serum IgE concentrations in clinic subjects tended to increase in the order White -- Cape Coloureds -- Blacks, these racial differences were not as pronounced as in blood donors. Also, olinic subjects showed no sex difference in serum IgE concentrations.

Adolescent↗
PubMed1975

The effects of sex and age on serum IgE concentrations in three ethnic groups.

Serum IgE concentrations were measured using a radio-radial immunodiffusion method in 4,440 blood donors resident in the Western Cape Province, South Africa, and the following differences were observed. Firstly, in all three ethnic groups studied, that is the Whites, the Cape Coloureds and the Africans, there was a tendency for males to have higher serum IgE concentrations than females. This differences was highly significantly in Whites. Secondly, in the Whites, serum IgE concentrations tended to be lower with advancing age. Thirdly, previous reports of elevated serum IgE concentration in indigenous African population were confirmed. No clearly defined cause for these differences emerged rom this study.

Adolescent↗
PubMed1975

Effects of allergy, intestinal helminthic infestation and sex on serum IgE concentrations and immediate skin hypersensitivity in three ethnic groups.

Serum IgE concentrations were measured in 232 blood donors resident in the Western Cape, South Africa. Subjects were interviewed for histories of allergy and skin tested with a variety of common allergens. Faecal specimens were collected for microscopic examination. Results confirmed that Cape Coloureds and Africans tend to have elevated serum IgE concentrations and showed that African males have a high prevalence of immediate skin hypersensitivity. Cape Coloureds and Africans had high prevalences of helminthic infestation and relatively low prevalence of allergic symptoms. Only in Whites were elevated serum IgE concentrations associated with positive allergic histories; in this group, results suggested that the sex difference in serum IgE concentrations observed previously is owing to differences in the IgE responses of allergic males and females.

Blood Donors↗