The importance of Toxoplasma gondii in human disease stimulated a number of electron microscope studies on the structure of this protozoan parasite. Gustafson et al. first studied the fine structure by means of thin sections in 1954. Many other papers havs subsequantly appeared. It is well known that Toxoplasma gondii has two stages in its life cycle-the proliferative forms and the cyst. The purpose of the electron microscopical work reported here was to study the fine structure of Toxoplasma gondii with recent techniques clarifying the correlation between the proliferative forms and cyst. RH strain and KM strain as proliferative forms on the one hand and Beverley strain as a cyst form of Toxoplasma gondii on the other hand were used throughout this study. The conoid, toxoneme, nucleus, nucleolus, osmiophilic granules, mitochondria and vacuoles were found in RH strain as wsll as in KM strain and Beverley strain. The endoplasmic reticulum was found in the cytoplasm of RH strain and KM strain. It was better developed in KM strain than in RH strain. The outside contour of the organism of Beverley strain was somewhat irregular and toxoneme of this organism was better developed than in the other two strains. Vacuoles were found in RH strain, KM strain and Beverley strain. Furthermore, tube-like bodies were observed in the vacuoles of the organism of RH strain. In KM strain, two organisms of the same size were demonstrated in the leucocytes. It was presumed that they were products of longitudinal division.
parasitology-protozoa- Toxoplasma gondii ; electron microscopy

A total of 377 pregnant women, 43 pelvic tumor patients and 80 of multiphysic health center persons as controls were examined by indirect latex agglutination test in order to evaluate Toxoplasma antibody titers at Kang-Nam St. Mary's Hospital in Seoul. Throughout this survey, 1:32 or more titers of diluted sera were regarded as positive. The 337 samples of test sera in pregnant women showed negatives in 319 cases (84.6 percent), 1:2 in 44 cases (11.7 percent), 1:4 in 9 cases (2.4 percent), 1:8 in 2 cases (0.5 percent), 1:16 in 1 case (0.3 percent) and 1:32 in 2 cases (0.5 percent) respectively. The 43 samples of test sera in pelvic tumor patients showed negatives in 29 cases (67.4 percent), 1:2 in 8 cases (18.6 percent), 1:4 in 1 case (2.3 percent), 1:16 in 2 cases (4.7 percent), 1:32 in 1 case (2.3 percent) and 1:128 in 2 cases (4.7 percent). The 80 samples of test sera in multiphysic health center persons as controls negatives in 56 cases (70.0 percent), 1:2 in 19 cases (23.8 percent), 1:4 in 3 cases (3.8 percent), 1:8 in 1 case (1.3 percent) and 1:128 in 1 case (1.3 percent). Among total 420 study cases, 5 cases (1.2 percent) showed positives , and they were 2 cases (0.5 percent) of pregnant women and 3 cases (7.0 percent) of pelvic tumor patients. One case (1.3 percent) out of 80 control sera showed positive result.
parasitology-protozoa ; Toxoplasma gondii ; diagnosis ; immunology

A total of 421 patients hospitalized in St. Mary's Hospital were examined by indirect latex agglutination test in order to evaluate the Toxoplasma antibody in Korean from June to August 1981. The test sera of the patients were obtained from each age group by random sampling. The 421 samples of test sera showed negative in 153, 1:2 in 157, 1:4 in 59, 1:8 in 27, 1:16 in 7, 1:32 in 9, 1:64 in 2, 1:128 in 4 and 1:256 in 3 cases, respectively. The positive rate of Toxoplasma antibody was 4.3 percent in this sample when indirect latex antibodies of 1:32 or higher were regarded as positive. The titers of positive Toxoplasma antibodies were increased by age.
parasitology-protozoa ; Toxoplasma gondii ; toxoplasmosis ; immunology ; diagnosis

Serological studies on toxoplasmosis were conducted with rabbits sera that were immunized with RH strain or infected with Beverley strain of Toxoplasma gondii. Complement fixation tests, agar-gel double diffusion tests and agar-gel immunoelectrophoresis were performed. Toxoplasma crude antigen was prepared from the organisms in mice peritoneal fluids, which were infected with RH strain of Toxoplasma gondii. The organisms were suspended in saline volume originally exudated and counted in hemocytometer for purity of the organisms over 99 per cent. These suspended organisms were prepared by sonication, and the solution was centrifuged for 30 min. at 10,000 rpm in 4C. These supernatant fluids were used as crude antigen. On the other hand, purified antigens were fractionated on Sephadex G-200 gel filtration. A Sephadex G-200 column, 80 by 4 cm, equilibrated with Tris-HCl-(0.1 M)-NaCl (1.0 M) buffer, pH 8.0 was used. The eluate fractions were collected in 3 ml per hour and the absorbance at 280 nm was measured with a Beckman Du-2 spectrophotometer. Each tube is pooled into 6 fractions by protein density graph. For immunization of rabbits, crude antigen of RH strain was emulsified with an equal amount of incomplete Freund's adjuvant and l ml of mixture was injected subcutaneously into them once a week for 5 successive weeks. Antisera were obtained at an interval of a week, beginning the first week after the last immunization, while several rabbits were infected with Beverley strain of Toxoplasma gondii by inoculating about 200 cysts and antisera were obtained from them serially at a week interval. The results were as follows: The sera from the rabbits immunized with the RH strain or infected with Beverley strain of Toxoplasma gondii againist the crude antigen showed the first positive reactions in 2 or 3 weeks after the administration or immunization in complement fixation tests. Maximum titers appeared in 4 or 5 weeks after immunization with RH strain and in 7 or 9 weeks after infection with Beverley strain respectively. Complement fixation tests showed the positive reactions in the rabbits sera immunized with RH strain against the purified antigens II, III, IV, V and VI: moreover, antigen IV fraction showed the highest titer. On the other hand in the rabbits sera infected with Beverley strain against the purifed antigens II, III and IV fractions showed the positive reaction; especially, antigen fraction IV showed the highest titer. In immuno-diffusion tests, the sera from the rabbits immunized with RH strain and infected with Beverley strain, against the crude antigen appeared the precipitin bands 2 weeks after the immunization or infection. And the former showed the 2 or 5 precipitin bands after 5-8 weeks and the latter showed the l or 2 precipitin bands after 6 weeks. The sera from the rabbits immunized with RH strain against the purified antigens II, III, IV,V and VI showed the precipitin bands, and the sera from the rabbits infected with Beverley strain against the purified antigens II, III and IV showed the precipitin bands in the immuno-diffusion tests. Especially antigen IV was the strongest reaction against the sera from RH strain and Beverley strain. In agar-gel immunoelectrophoresis, the immunized sera against the crude antigen showed 8 arcs. But the infected sera against the crude antigen showed 4 or 5 arcs. The immunized sera against the fractionated antigens II, III, IV, V, VI showed arcs, but against the fractionated antigen IV showed 6 arcs and in the antigens II, III, V, VI showed l or 2 arcs only. On the other hand, the infected sera against the fractionated antigens IV showed 4 arcs, II and III showed the l arcs, which was the most weak of all.
parasitology-protozoa-Toxoplasma gondii ; toxoplasmosis ; rabbit ; immunology ; electrophoresis

Surface membrane proteins of virulent RH strain and tissue cyst-forming Fukaya strain of Toxoplasma gondii were analyzed by SDS-polyacrylamide gel electrophoresis after LPO-catalyzed surface iodination and lectin blotting, then identified the zoite-specific antigens. Prior to the analyses, purification of RH tachyzoites from mouse peritoneal exudate and of Fukaya bradyzoites from mouse brain tissues were performed by centrifugation on the discontinuous Percoll density-gradient. Tachyzoites were obtained at the interface of 50 per cent and 60 per cent Percoll solution and brain cysts were harvested at the interfaces of 40-50 per cent and 50-60 per cent, then bradyzoites were obtained by treating the cysts with hypertonic solution. The LPO-catalyzed iodination detected 15 KDa and 14 KDa proteins of bradyzoites and 30 KDa protein of tachyzoites as major bands with several other minor bands. But Con A blotting revealed some bands of 200 K-50 KDa glycoproteins of bradyzoites and 52 KDa band as major and minor bands of 33 K-20 KDa of tachyzoites. Phytohemagglutinin did not detect any band in the two forms. EITB with anti-Fukaya antibody and anti-RH antibody revealed cross-reactivities between the two forms. Despite the cross-reactivity, anti-Fukaya antibody reacted with 15 KDa band of bradyzoites specifically and, anti-RH antibody with 52 KDa, 30 KDa, and 25 KDa bands of tachyzoites, respectively. It was identified that 15 KDa protein in bradyzoite, which was not a glycoprotein, was a major membrane protein with sufficient antigenicity, and in the case of tachyzoite, 52 KDa surface glycoprotein (gp52) with specific antigenicity might be added to the major surface protein, p30.
parasitology-protozoa ; Toxoplasma gondii ; biochemistry ; membrane protein ; antigen ; glycoprotein

In vitro culture of Toxoplasma gondii in HL-60 cells cnd cell-mediated immunity against Toxoplasma in dimethylsulfoxide(DMSO)-induced HL-60 cells, i.e., differentiation into granulocytes, were pursued. HL-60 cells were treated with various concentrations of DMSO, and 1.3%(v/v) for 3 day incubation was chosen as the optimal condition for differentiation into granulocytes. The degree of differentiation was assayed in physiological and functional aspects in addition to morphological point. When treated with 1.3% DMSO for 3 days, HL-60 cells did not synthesize DNA materials beyond background level, and showed active chemotactic response to chemotactic peptide, formyl-methionyl-leucyl-phenylalanine(FMLP). Morphologically promyelocytes of high nuclear/cytoplasmic(N/C) ratio changed to granulocytes of relatively low N/C ratio. The relationships between HL-60 cells or DMSO-induced HL-60 cells and Toxoplasma were examined after stain with Giemsa and fluorescent dye (acridine orange). HS-60 cells did not show any sign of toxoplasmacidal activity but showed intracellular proliferation of Toxoplasma to form rosette for 72 hr co-culture. In contrast, DMSO-induced HL-60 cells phagocytosed Toxoplasma within 1 hr, and performed a process of intracellular digestion of Toxoplasma thereafter. With the above results, it is suggested that phagosome-lysosome fusion is one of the critical events for the parasitism by Toxoplasma or for susceptibility of host cells. The in vitro culture system of this study has offered a defined condition to study the protozoan parasite-host cell interactions.
parasitology-protozoa ; Toxoplasma gondii ; HL-60 cells ; dimethylsulfoxide ; in vitro culture ; dimethylsulfoxide

A total of 573 patients hospitalized in National Seoul Mental Hospital and 76 of healthy persons as control were examined by indirect latex agglutination test in order to evaluate Toxoplasma antibody titers in mental patients. Throughout this survey, 1:32 or more titers of diluted sera were regarded as positive. The 573 samples of test sera showed negative in 386 cases (67.4 percent), 1:2 in 93 cases (16.2 percent), 1:4 in 57 cases (9.9 percent), 1:8 in 14 cases (2.4 percent), 1:16 in 12 cases (2.1 percent), 1:32 in 5 cases (0.9 percent), 1:64 in 1 case (0.2 percent), 1:128 in 3 cases (0.5 percent) and 1:256 in 2 cases (0.3 percent) respectively. Among total 573 mental patients, 11 cases (19 percent) showed positive, and they were 9 cases (1.8 percent) of schizophrenia and 2 cases (7.4 percent) of manic depression. One case (1.3 percent) out of 76 control sera showed positive result.
parasitology-protozoa ; Toxoplasma gondii ; immunology ; indirect latex agglutination test ; schizophrenia ; manic depression

The chemotherapeutic efficacy of trimethoprim-sulfamethoxazole (Bactrim) in mice experimentally infected with Toxoplasma gondii was evaluated. The average survival days and survival rate of mice infected intraperitoneally with 1 x 10(5) trophozoites and treated with Bactrim were compared with those of untreated group. The hematologic findings of blood samples of experimental mice were observed for comparison of side effects between Bactrim and pyrimethamine (Daraprim), the latter of which has been one of the favorable drugs for the treatment of toxoplasmosis. The results are summarized as follows: Bactrim showed a strong evidence of potent anti-Toxoplasma activity. The survival rate of mice administered with 24 mg of Bactrim per mouse per day for 7 days, was 83.3 percent, and the rate was increased to 100 percent in mice administered with two-fold concentrated dose of the drug. The average numbers of white blood cells (W.B.C.) in the mouse groups treated with Bactrim or Daraprim were more increased than those only infected with T. gondi . The mice treated with Daraprim, however, showed remarkably decreased numbers of W.B.C. as compared with those treated with Bactrim. The average numbers of red blood cells (R.B.C.) and platelets both in the drug-treated and untreated T. gondii-infected mice were decreased as compared with normal mice. The numbers of R.B.C. in Daraprim-treated mice, however, were more decreased than in Bactrim-treated mice. The average levels of hemoglobin both in the drug-treated and untreated T. gondii-infected mice were decreased, compared with normal mice. But there was no difference in the levels of hemoglobin between Bactrim- and Daraprim-treated groups. In conclusion, trimethoprim-sulfamethoxazole (Bactrim) was proven to be effective and safe for the treatment of murine toxoplasmosis. The efficacy was comparable with pyrimethamine (Daraprim), but bone marrow depression was less severe with Bactrim treatment.
parasitology-protozoa ; Toxoplasma gondii ; toxoplasmosis ; chemotherapy ; trimethoprim-sulfamethoxazole ; pyrimethamine ; mouse ; trimethoprim-sulfamethoxazole ; pyrimethamine

The development of antibody titers and cross reation between Sarcocystis and Toxoplasma were investigated by means of IFA test and ELISA in pigs experimentally infected with 1.5 x 10(6) S. suicanis sporocysts and 10,000 T. gondii oocysts, respectively. The intact and soluble Sarcocystis antigens were prepared from the bradyzoites harvested by peptic digestion of infected pork. The intact and soluble Toxoplasma, antigens were prepared from the tachyzoites in mouse peritoneal cavity. IgG antibodies in pigs infeded with Sarcocystis and Toxoplasma, respectively were detected first at 2 weeks post infection on both IFA test and ELISA. The antibody titer to Toxoplasma reached its maximum at 6 weeks post infection and decreased thereafter. The antibody titer to Sarcocystis reached its maximum terminally. The cross-reaction titer in pigs infected with Toxoplasma against Sarcocystis antigen was up to 1:16 in IFA test and up to 1:32 in ELISA. The titer in control group was below 1:4 in both reactions.
parasitology-protozoa ; Toxoplasma gondii ; Sarcocystis suicanis ; immunology ; diagnosis ; immunofluorescence ; enzyme-linked immunosorbent assay

Total of 216 animals conserved in Seoul Grand Park were examined on the antibody titers of Toxoplasma by the indirect latex agglutination test, 20 out of 131 cases (15.3%) in mammals, 2 out of 75 cases (2.7%) in birds, and none in reptiles, according to species, 15 out of 68 species (22.1%) in mammals, 2 out of 36 species (5.6%) in birds showed positive antibody titers when the titers of 1:32 or higher were regarded as positive. In mammals, it appeared as positive in 2 out of 6 cases (1 out of 3 species ) in marsupials, 1 out of 15 cases (1 out of 11 species) in primates, 1 out of 1 case in bats, 6 out of 13 cases (5 out of 10 species) in carnivores, 1 in 12 cases (1 species out of 3) in odd-toed ungulates, 9 out of 80 cases (6 species out of 38) in even-toed ungulates, and none in rodents and in whales. In birds, 1 out of 21 cases (1 out of 7 species) in gallinaceous birds and 1 out of 6 (5 species ) in parrots appeared to have the positive antibody titers of Toxoplasma. And, none of reptiles showed positive. Frequencies of positive antibody titers were high in 1: 64, 9 cases in mammals followed by 1: 32, 6 cases, 1: 128, 3 cases, and 1: 256, 2 cases, respectively. Two positive cases in birds appeared to be 1: 64.
parasitology-protozoa ; Toxoplasma gondii ; epidemiology ; marsupial ; primate ; bat ; rodent ; whale ; carnivore ; ungulate