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Biomedical subjects

W G Harris

Publications and source records attributed to W G Harris.

At least 37 records · Page 2Linked to original sources

The epidemiology of infection with Entamoeba histolytica in the Gambia, West Africa.

A country-wide stool survey of The Gambia showed the prevalence of Entamoeba histolytica cysts to range from 13.7% up-country in the dry season to 52.3% near the coast. A longitudinal survey showed a near 100% infection rate over one year and a sharp rise in prevalence as the rains commence with an equally sharp fall as the rains progress. Specific antibody levels are elevated and reasonably constant through the year. Carriers generally show no specific lymphocyte reactivity to amoebic antigen but consistently parasite-negative individuals tended to show elevated lymphocyte reactivity. Attempts to discover the presence of cysts in the environment of villages by cultivation of specimens of water, soil, food, flies and washing from clothes and hands generally failed though E. histolytica was recovered once from a well.

Amebiasis↗

Cellular immune responses to amoebic liver abcess in the guinea-pig.

Guinea-pigs infected in the liver with the Biswas strain of Entamoeba histolytica showed no dermal hypersensitivity but showed positive lymphocyte transformation and macrophage-migration inhibition. The time sequence showed an activated response at 4 days after infection, a full response at 8 days when the liver abscesses were resolving and a waning response at 12 days when the abscesses had healed.

Animals↗

Haematological and immunological responses to the tapeworm hymenolepis diminuta in man.

Self-infections with the tapeworm Hymenolepis diminuta were carried out to study the haematological and immunological responses in man. Infection caused pronounced eosinophilia, an increase in plasma viscosity and the production of parasite-specific IgG and IgM. Circulating IgE was not detected. There were no significant changes in erythrocyte values or serum transaminases.

Adult↗

The allergens of Schistosoma mansoni. II. Further separation by sephadex G-200 and ion-exchange chromatography.

A total of thirty-five antigen fractions were prepared from adult Schistosoma mansoni by extraction into borate-buffered saline, precipitation at pH 4-6, gel-filtration on Sephadex G-100 and G-200, and ion-exchange chromatography on CM- and DEAE-cellulose. The allergic activity of these antigens was assayed by a modified Prausnitz-Küstner (P-K) type reaction in rats. The results showed that the allergen-reagin axis in rat schistosomiasis is a multicomponent system involving molecules of widely different chemical nature and molecular weight, rather than a simple, single antigen-antibody interaction. The significance of these findings to the use of purified antigens for the diagnosis of schistosomiasis in the field is discussed.

Allergens↗