Biomedical subjects

D W Shin

Publications and source records attributed to D W Shin.

25 records · Page 2Linked to original sources

PubMed1994

Effects of cytokines in the activation of peritoneal macrophages from mice infected with Toxoplasma gondii.

The present study was undertaken to assess the role of cytokines in the activation of peritoneal macrophages from Toxoplasma-infected mice. Peritoneal macrophages from Toxoplasma-infected mice (10 cysts of Beverley strain/mouse) were harvested 8 weeks after infection, and incubated with the mitogen-induced lymphokine, recombinant mouse interferon-gamma (IFN-gamma), recombinant mouse tumor necrosis factor-alpha (TNF-alpha) alone or in combination with IFN-gamma (IFN-gamma/TNF-alpha) for 24 hr at 37 degrees C, 5% CO2. Macrophage activation was measured by the amount of H2O2 and NO2- production, and anti-Toxoplasma activities of macrophages. IFN-gamma or IFN-gamma/TNF-alpha-treated macrophages from Toxoplasma-infected mice revealed significantly higher H2O2 production than resident macrophages from Toxoplasma-infected mice. The production of NO2- by TNF-alpha-, IFN-gamma- or IFN-gamma/TNF-alpha-treated macrophages from Toxoplasma-infected mice were significantly higher than that by resident macrophages, whereas lymphokine-treated group produced similar amount as that produced by resident macrophages. Anti-Toxoplasma activities of cytokine-treated macrophages from Toxoplasma-infected mice were significantly higher than those of resident macrophages. IFN-gamma-treated macrophages were significantly increased production of H2O2 and NO2-, and anti-Toxoplasma activities of macrophages between normal and Toxoplasma-infected mice, whereas the other cytokine-treated groups were not significant differences between them. These data suggested that IFN-gamma was the only one of cytokines capable of significantly activating the peritoneal macrophages from Toxoplasma-infected mice.

Animals↗

PubMed1994

[Intestinal parasite and Clonorchis sinensis infection among the inhabitants in the upper stream of Taechong Dam, Kumgang (River)].

The prevalence of intestinal parasites and Clonorchis sinensis infection was observed among inhabitants in the upper stream of Kumgang (River) from January to October 1991. A total of 743 fecal specimens was examined by cellophane thick smear and formalin-ether concentration technique. The parasite positive rate including helminth eggs and protozoan cysts was 40.8%, the positive rates for every species were: Clonorchis sinensis 30.8%, Metagonimus spp. 14.5%, Fasciola spp. 0.7%, Taenia spp. 1.5%, Ascaris lumbricoides 0.4%, Enterobius vermicularis 0.1%, Hookworm 0.1%, Trichuris trichiura 1.6%, Entamoeba coli 0.7%, E. histolytica 0.3%, Endolimax nana 0.3%, Giardia lamblia 0.3% and Iodamoeba buetschlii 0.1%, respectively. The cumulative positive rate in Okchon-gun showed 51.1%, in the Kumsan-gun 50.8% and in the Muju-gun 28.6%. Through this survey, it was concluded that the soil transmitted intestinal parasites including helminthseggs and protozoan cysts have been decreased remarkably among the inhabitants along the upper stream of Taechong Dam, Kum-gang (River), on the other side, Clonorchis sinensis, Metagonimus spp. and Taenia spp. are still morderate prevalent.

Adolescent↗

PubMed1993

[Effects of interferon-gamma in T cell subsets of mice infected with Toxoplasma gondii].

This study was performed to evaluate differences of T cell subsets according to the injection period of recombinant mouse interferon-gamma (IFN-gamma) in acute Toxoplasma gondii infection. Each mouse was infected intraperitoneally with 100 cysts of Beverley strain T. gondii, and injected with 5 x 10(4) units of IFN-gamma every other day two tmres. The percentage of Thy-1,2 cells and L3T4/Ly-2 cell ratio were significantly increased in the mice that received two doses of IFN-gamma on days 2 and 0 before infection, or days 0 and 2 after infection. The percentage of Ly-2 cells decreased in the IFN-gamma injected groups at the 3rd and 4th week after infection. The results suggest that administration of IFN-gamma to T. gondii-infected mice improves the changed population of T cell subsets to a normal state, especially when IFN-gamma was injected just after the infection.

Animals↗

PubMed1993

[Prophylactic effects of trimethoprim-sulfamethoxazole in Toxoplasma-infected mice].

This study was performed to evaluate the prophylactic effects of trimethoprim-sulfamethoxazole (TMP-SMZ) in mice experimentally infected with virulent RH strain and avirulent Beverley strain of T. gondii. The mice infected with 1 x 10(5) tachyzoites were used in the measurement of mean survival days, and the mice infected with 10 cysts were used in the titrations of specific antibodies and enumeration of brain cysts. Mean survival days of mice were significantly increased in mice treated with TMP-SMZ as compared with spiramycin-treated and untreated control group. Mean survival days and survival rates of mice were increased according to the increment of dosages, and TMP-SMZ protected 100% of mice after fifteen daily dose of 24 mg/mouse or more administered orally. Toxoplasma-specific serum IgG and IgM antibody titers were significantly lower in mice treated with TMP-SMZ than those of spiramycin-treated and untreated control group. Toxoplasma cysts were not found in mice treated with TMP-SMZ at a dose of 24 mg/mouse or more per day, but the group of spiramycin treatment and untreated controls were found in the brain from 20 days after infection. The present results revealed that TMP-SMZ can be used as a prophylactic agent against murine toxoplasmosis after intraperitoneally challenges with the virulent or avirulent strain of T. gondii.

Animals↗

PubMed1992

[Changes in blastogenic responses and antibody titers of mice infected with Toxoplasma gondii].

This study was performed to observe the cell-mediated and humoral immune responses in mice which were infected with Beverley, Fukaya and ME49 strain of Toxoplasma gondii, respectively. The blastogenic responses of splenocytes using [3H]-thymidine and serum antibody titers were measured weekly up to 10 weeks after infection. The blastogenic responses of splenocytes treated with concanavalin A and Toxoplasma lysate were significantly declined in the 3 strain groups as compared with the non-infected group (p less than 0.05), however lipopolysaccharide-treated blastogenic responses were not significantly different between infected and non-infected groups. The serum IgG antibody titers in the three infected groups increased from 2 weeks after infection, and the serum IgM antibody titers increased until 4 weeks after infection. No significant differences were revealed in blastogenic responses and serum antibody titers among the 3 groups. The present study suggested that cell-mediated immune responses were involved in T. gondii infected mice and blastogenic responses of T lymphocytes were inhibited in acute T. gondii infection.

Animals↗

PubMed1992

[Study on the therapeutic effects of interferon and gamma-globulin in experimental Pneumocystis carinii pneumonia].

This study was performed to observe the therapeutic effects of interferon-gamma(IFN-gamma) and gamma-globulin(gamma-globulin) in experimental Pneumocystis carinii pneumonia of immune suppressed mice. After 9 weeks, trimethoprim-sulfamethoxazole(TMP-SMZ; 10-50 mg/mouse/day), mouse IFN-gamma(5 x 10(4) units/mouse/day) and mouse gamma-globulin(20 mg/mouse/day) were administered to the mice for 3 weeks by the experimental group. The therapeutic efficacy was evaluated by body weights, histopathologic and electron microscopic findings of the lungs, and number of P. carinii cysts by Gomori's methenamine silver stain. Body weights of the mice were significantly increased in the group of combination therapy of TMP-SMZ with IFN-gamma or gamma-globulin, and in the group of TMP-SMZ treatment (p < 0.05), however, little effect was found in the group of gamma-globulin alone. Histopathologic findings of P. carinii pneumonia were much improved in the group of combination therapy of TMP-SMZ with IFN-gamma. Treatment with either TMP-SMZ or IFN-gamma significantly reduced the number of cysts in the P. carinii pneumonia, but gamma-globulin alone was ineffective. In electron microscopic findings of P. carinii pneumonia, the number of trophozoites and cysts were reduced by treatment with either TMP-SMZ or IFN-gamma, and most of the cysts were empty or containing one or two intracystic bodies. The present results suggested, that combination therapy of TMP-SMZ with IFN-gamma had synergistic effects in treatment of P. carinii pneumonia in experimental mice.

Animals↗

PubMed1989

[An experimental study on prednisolone-induced interstitial pneumonia caused by Pneumocystis carinii].

This study was performed to observe the role of Pneumocystis carinii as an etiologic agent of interstitial pneumonia in immunocompromised hosts. Total 90 male Sprague-Dawley rats, approximately 150-180 g, were used. Fifteen of them were used as control group and remaining 75 (5 groups) were as immunosuppression groups; group 1 received prednisolone (25 mg/kg twice weekly) only; group 2 prednisolone and tetracycline (75 mk/kg/day); group 3 prednisolone, tetracycline and trimethoprim-sulfamethoxazole (50-250 mg/kg/day); group 4 prednisolone and trimethoprimsulfamethoxazole; and group 5 prednisolone and griseofulvin (300 mg/kg/day) until death. The survival days of each group rat were calculated, and upon death their lungs were removed immediately and then stamp smears were prepared and stained by Giemsa or toluidine blue O. For histopathologic observation, lungs were fixed in 10% formalin, cut into sections and stained with Gomori's methenamine silver, hematoxylin-eosin, and Brown & Brenn stain. The results obtained were as follows: 1. The mean survival time of each group rat was 19.3 +/- 5.2 days (group 1), 41.1 +/- 14.0 days (group 2), 50.5 +/- 18.4 days (group 3), 43.0 +/- 22.9 days (group 4) or 21.8 +/- 5.1 days (group 5). Significant differences were noted between group 1 and group 2(p less than 0.01), group 1 and group 3 (p less than 0.01), and group 1 and group 4 (p less than 0.01), which represented bacterial infections were most fatal in immunocompromised rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗