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Biomedical subjects

K S Warren

Publications and source records attributed to K S Warren.

At least 91 records · Page 5Linked to original sources

The Schistosoma japonicum egg granuloma. II. Cellular composition, granuloma size, and immunologic concomitants.

Studies of granulomatous hypersensitivity to Schistosoma japonicum eggs were performed at various time periods up to 20 wk after the induction of light infections in mice. Cell populations which were determined in granulomas isolated from the livers revealed a maximum in the total number of cells at 6 wk with a decline of 36% by 20 wk. Large mononuclear cells were predominant at all time periods, with eosinophils being the second most common cell. Measurements of granuloma diameters around single viable eggs in the livers also revealed peak size at 6 wk with a decline of 51% between 16 and 24 wk. Immunodiffusion analysis demonstrated the presence of precipitating antibodies as early as 7 wk after infection. Investigations of lymphocyte blastogenesis revealed a profound depression in response to T-cell mitogens by 8 wk of infection. Studies of footpad swelling to soluble S. japonicum egg antigens revealed massive immediate reactions starting at 6 wk. but no delayed reactivity over a period from 3 to 20 wk. All of these results are related to differences in the biology of S. japonicum in comparison with S. mansoni with respect to the earlier onset of egg production, the much larger numbers of eggs produced, and the possibility of differences in the antigens emitted by the eggs.

Animals↗

Purified antigen radioimmunoassay in serological diagnosis of schistosomiasis mansoni.

A radioimmunoassay has been developed for detecting human schistosomiasis with a highly purified Schistosoma mansoni egg antigen labelled with iodine-125. The antigen, major serologic antigen 1 (M.S.A.1), has striking immunochemical and species specificity and appears to be the principal antigen responsible for the granulomatous response to S. mansoni eggs. This 125I-antigen was tested with 5 microliter of patient serum as a potential serodiagnostic test for schistosomiasis. 92 control sera from uninfected St. Vincentian patients were seronegative. In studies on 135 lightly infected St. Lucians the 5 microliter serum 125I-M.S.A.1 serodiagnostic test was more sensitive than any tests available at the Center for Disease Control, with 64% of infected children, 83% of adolescents, and 98% of adults being positive. 49 heavily infected Kenyans of all age-groups were uniformly (100%) seropositive. Finally, a semiquantitative version of the 125I-M.S.A.1 radioimmunoassay that uses 0-5 microliter of patient sera demonstrated quantitatively significant differences among age-watched and intensity-watched groups of patients with S. mansoni, S. haematobium, and S. japonicum infections.

Adolescent↗

Eosinophils and resistance to Trichinella spiralis.

Mice infected with Trichinella spiralis were depleted of eosinophils by repeated administration of rabbit anti-mouse eosinophil serum. There was no effect on the spontaneous expulsion of adult worms from the small intestines, but the numbers of larvae in the muscles were almost doubled. It is concluded that eosinophils contribute to resistance to the systemic phase of trichinosis.

Animals↗

The Schistosoma mansoni egg granuloma: quantitation of cell populations.

Granulomas were induced by the intravenous injection of eggs of Schistosoma mansoni into the lungs of mice which were either unsensitised, sensitised by prior intraperitoneal injection of eggs, or naturally infected with S. mansoni. At various time intervals after egg injection (8, 16 and 32 days in unsensitised mice; 4, 8 and 16 days in sensitised mice; and 8 days in mice infected for 4, 8 16 and 24 wk) the lungs were removed from groups of mice and were placed in a Waring blender at low speed. Complete intact granulomas were isolated, the lesions were dispersed with collagenase and pronase and the cell populations quantified and classified as eosinophils, neutrophils and mononuclear cells less than or equal to 12 or greater than 12 micron in diameter. Small mononuclear cells consisting almost exclusively of lymphocytes were the predominant cells initially, but eosinophils became the most common cell type, reaching a peak of 71% of cells in sensitised animals 16 days after injection. Large mononuclear cells remained relatively constant at about 30% of the total cells. Neutrophils neverreached more than 10% of cells. Sensitisation by a prior intraperitoneal injection of eggs led to an acceleration of granuloma formation. In infected mice, the granulomas with the largest cell counts were seen 8 wk after infection while the smaller granulomas in the mice infected for 16 or 24 wk confirm the previously reported modulation of this immunopathological reaction.

Animals↗

Toxoplasmosis and the host-parasite relationship in murine schistosomiasis mansoni.

Infection with Toxoplasma gondii has been shown to suppress markedly the in vitro splenic lymphocyte response to nonspecific mitogens and the in vivo antibody response to sheep red blood cells. The effect of toxoplasmosis on an in vivo cell-mediated response, granuloma formation around Schistosoma mansoni eggs, was examined in the present study. The granulomas were markedly suppressed from two to 20 weeks after infection with T. gondii. In subsequent experiments the effect of toxoplasmosis-induced immunosuppression on the development of hepatosplenic schistosomiasis was evaluated. Mice with the combined infections had markedly smaller hepatic granulomas and lower mean portal pressures than those infected with S. mansoni alone. Although the prevalence of esophageal varices in the mice with schistosomiasis alone was 60%, there was no visible collateral circulation in the animals with both infections.

Animals↗

Kinetics of immunological responses, resistance to reinfection, and pathological reactions to infection with Trichinella spiralis.

Changes in immune responses, resistance to reinfection, and pathological reactions were studied serially in mice that had been infected for four to 40 weeks with 150 larvae of Trichinella spiralis. Immediate footpad hypersensitivity reactions to antigens of Trichinella were present throughout the period of observation. Delayed hypersensitivity reactions 48 hr after injection of antigen were first seen in mice infected for 14 weeks and gradually increased in size thereafter. Intestinal adult worm burdens were determined one week after challenge with 5000 larvae. There was resistance to reinfection and accelerated expulsion of worms in animals challenged three weeks after the primary infection; this resistance waned at seven and 13 weeks but reappeared in mice infected for 20 weeks or longer. Counts of larvae in muscle were determined four weeks after challenge with 5000 larvae. Marked resistance was present four weeks after the primary infection and was maintained for the duration of the study.

Animals↗