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D G Dusanic

Publications and source records attributed to D G Dusanic.

At least 37 records · Page 2Linked to original sources
PubMed1982

Crossed-immunoelectrophoretic analyses of Trypanosoma cruzi epimastigote, metacyclic, and bloodstream forms.

Sonicated suspensions of epimastigote, metacyclic, or bloodstream forms of Trypanosoma cruzi were emulsified in Freund's complete adjuvant. Rabbits immunized with epimastigotes or metacyclics received five intramuscular (i.m.) injections of 1 x 10(9) sonicated trypanosomes at weekly intervals. Immunization with bloodstream forms included three i.m. injections of 5 x 10(7) and six injections of 2 x 10(8) sonicated trypanosomes. Selected antisera from these rabbits were employed in crossed immunoelectrophoretic studies against the homologous or heterologous extracts of sonicated trypanosomes. Extracts of epimastigote, metacyclic, and trypomastigotes produced 31, 29, and 11 precipitin peaks respectively against the homologous rabbit antisera. Tandem, crossed-immunoelectrophoresis of these extracts against antiepimastigote or antimetacyclic sera revealed that epimastigotes or metacyclics may each have at least four antigens that did not appear to be shared by the other, whereas each of these forms may have at least eight or nine antigens that were not detected with extracts from trypomastigotes. Cross-absorptions of antiepimastigote or antimetacyclic sera with live trypanosomes caused marked reductions in the numbers of precipitin peaks formed against the homologous extracts, but cross-absorptions with sonicated suspensions of epimastigotes or metacyclics showed that epimastigotes or metacyclics each have at least two antigens that were not detected in extracts of the other. Differentiation appeared to be accompanied by antigenic change. More antigens appear to be shared by epimastigotes and metacyclic forms than by trypomastigotes and epimastigotes or metacyclics.

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PubMed1979

Antigenic analyses of two axenized strains of Entamoeba histolytica by two-dimensional immunoelectrophoresis.

Antigens in extracts of two strains of Entamoeba histolytica (HT-31 and HK-9) were studied by two-dimensional immunoelectrophoresis (2D-IEP) and 32 and 20 different antigenic components were detected, respectively. Cross-reactions between heterologous systems showed a large number of shared antigens between the two strains. Extracts were fractionated by Sephadex G-200 chromatography. Of the fractions obtained, fraction II of both strains was found to have the most reactive antigenic components. Precipitin patterns of fraction II from HT-31 and HK-9 with sera from patients showed similar 2D-IEP profiles and suggested that in this fraction antigens common to both strains exist which elicit antibody in individuals with E. histolytica infections.

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PubMed1978

Mechanisms of trypanosome-mediated suppression of humoral immunity in mice.

Spleen cells from Trypanosoma musculi-infected mice were unable to respond to sheep erythrocyte antigen in vitro; moreover, they suppressed the responses of normal spleen cell cultures in dose-dependent fashion. Suppression was maximal with spleen cells obtained during maximal parasitemia and waned as the donors recovered from infection. A macrophage-enriched population of spleen cells from infected mice, prepared either by adherence to plastic or by density gradient centrifugation, was not contaminated by the parasites and was not suppressive, whereas the plastic-nonadherent population was both contaminated and suppressive. Adherent and nonadherent cells of infected mice, separated by use of nylon wool columns, were almost equally suppressive and equally contaminated by trypanosomes. Addition of specific rabbit antiserum against T. musculi to cultures containing cells from infected mice eliminated contaminating parasites and alleviated suppression exerted by cells obtained from mice early during the course of infection but not after 12-15 days of infection. The suppression exerted by enriched T-cells obtained from mice on day 12 of infection was largely alleviated by use of the antiserum. A large portion of cells obtained on day 14 of infection could be killed by the antiserum and complement. It appeared that soluble substances derived from the parasites acted directly on B lymphocytes or essential assistant cells rather than by activating suppressor T cells or macrophages.

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PubMed1975

Comparative studies of Trypanosoma vespertilionis Battaglia and Trypanosoma dionisii Bettencourt & França.

In diphasic blood agar media Trypanosoma vespertilionis developed spheroid clusters as compared to rather long, sausage-shaped (sometimes branched) clusters formed by Trypanosoma dionisii. The former species attained a greater population density (approximately 6 X 10(7) organisms/ml) than the latter (approximately 2 X 10(7) organisms/ml). Greater numbers of epimastigotes, some in active binary divisions, were observed during the logarithmic phase of growth, and morphologic changes occurred during cultivation which correlated with increased acidity and a depletion of glucose. Maximum numbers of trypomastigote forms were found during the stationary and early death phases. Most of the forms observed after 20 days were sphaeromastigotes. Glucose concentrations decreased to 0 M in T. vespertilionis and to 4.4 X 10(-5) M in T. dionisii cultures during the stationary and death phases. By the 12th day of incubation cultures of T. vespertilionis were more acid (pH 5.5) than those of T. dionisii vespertilionis and T. dionisii contained common and specific antigens. At least 2-3 common antigens were detected in extracts reacted against heterologous antisera. Specific antigens were observed as nonidentical lines formed by extracts reacted against homologous and heterologous antisera and with antisera absorbed with heterologous antigens. At least 2 specific antigens were evident in extracts of T. vespertilionis and 1 in extracts of T. dionisii.

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