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Biomedical subjects

R J Wilson

Publications and source records attributed to R J Wilson.

At least 163 records · Page 9Linked to original sources
PubMed1976

Precipitating antibody response to malarial S-antigens.

The gel diffusion test has been used to detect antibodies to malarial S-antigens. Sera were obtained from entire Gambian village communities, from young children with acute P. falciparum malaria, from children convalescent from such infections and from immune adults. In community studies, small selections of S-antigens detected antibody frequently in sera from older persons but rarely in sera from young children. Larger panels of antigens detected antibodies in sera from half of 50 malarious children while homologous antibody responses were observed in 22% of 267 children followed at intervals during convalescence from malaria. In these latter cases, antibody tended to appear more swiftly when antigen was lost rapidly from the circulation, and observations made on individual responses indicated that antibody production was influenced by factors other than the intrinsic properties of the antigens. In adult sera antibodies usually occurred in association with IgG.

Adolescent↗
PubMed1975

Occurrence of S-antigens in serum in Plasmodium falciparum infections in man.

Gambians with severe Plasmodium falciparum infections frequently have malarial S-antigens in their serum or plasma. Detection of these with the available antisera which are from immune adults is complicated because there are many different S-antigens and none of the antisera contains antibodies to them all. Despite this we found S-antigens in about 60% of a large series of malarious children and demonstrated that this was a considerable underestimate of the true incidence. We also showed that the prevalence of S-antigens was related to the malaria season and to the intensity of infection.

Antigens↗
PubMed1975

Persistence and recurrence of S-antigen in Plasmodium falciparum infections in man.

The persistence of heat stable malarial antigens (S-antigens) in the sera of Gambian children following treatment for severe Plasmodium falciparum infections was investigated. In most cases S-antigens ceased to be demonstrable within 7 days but in some they were detected for several weeks and their persistence correlated with both the density of parasitaemia and the antigen titre observed before treatment. An exponential loss of circulating antigen was, in the majority of individuals, accelerated by some other factor which might have been homologous antibody. Renewal of asexual parasitaemia usually resulted in reduction in the rate of antigen loss or in an increase in antigen level. When the aparasitaemic interval was a month or less the antigens associated with different parasitaemic episodes usually showed identical specificities; when the interval was longer they were usually antigenically distinct. These findings may indicate that relapse parasites usually show the same S-antigen specificities as their progenitors while parasites arising from distinct infections tend to show different specificities and could therefore support a view that considerable antigenic heterogeneity exists among the parasites that comprise P. falciparum populations in endemic areas.

Antigens↗
PubMed1975

The release of antigens by Plasmodium falciparum.

Antigens were released in vitro human red cells infected with Plasmodium falciparum only when parasites reached a late stage of schizogony (probably at rupture of infected red cells during reinvasion). Immune complexes formed if antibody was present. Serum from immune Aotus monkeys opsonized parasite debris from artificially disrupted infected Aotus red cells.

Animals↗
PubMed1975

Acquired tracheomalacia: etiology and differential diagnosis.

The noninvasive diagnosis of impaired mechanical integrity or compliance of the trachea is most accurately made by fluoroscopic observation recorded on video tape or cineradiography, with or without benefit of artificial contrast media (contrast tracheography). In particular, localized buckling, collapse or dilatation indicative of focal tracheomalacia may thus be diagnosed in vivo and correlated with diseases of the central airways. Congenital tracheomalacia is a rare, bu, well described entity. Cases of acquired tracheomalacia occur with increasing frequency, but are often not clearly recognized. We contrast the dynamic behavior of the normal trachea with the abnormal dynamics characteristic of focal tracheomalacia. Such lesions may result from trauma, surgical procedures, chronic irritation, inflammation, mechanical changes, or malignancy.

Carcinoma, Adenoid Cystic↗