• Parasites, Hosts and Diseases
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• 제46권1호
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• pp.45-48
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• 2008

To evaluate the usefulness of the Korean Isolate-1 (KI-1) antigen for serodiagnosis of toxoplasmosis, antigen profiles of KI-1 tachyzoites were analyzed in comparison with RH tachyzoites by SOS-PAGE and immunoblotting. ELISA was performed on latex agglutination (LA)-positive and negative serum samples using KI-1 and RH antigens. Immunoblotting of the KI-1 antigen showed multiple antigen bands with molecular sizes of 22-105 kDa. Among them, 1 and 6 common bands were noted against a KI-1-infected and a RH-infected human serum, respectively, which represented differences in antigenic profiles between KI-1 and RH tachyzoites. However, all 9 LA-positive human sera were found positive by ELISA, and all 12 LA-negative sera were negative by ELISA; the correlation between the ELISA titers and LA titers was high (r = 0.749). Our results suggest that tachyzoites of KI-1 may be useful for serodiagnosis of human toxoplasmosis.

• 한국동물위생학회지
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• 제43권4호
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• pp.251-256
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• 2020

Two suckling piglets, 4 days and 10 days of age, showed lethargy and dyspnea after birth and mortality had been increased after incoming gilts from breeding farm. At necropsy, the lungs showed diffuse fail to collapse with rubbery consistency, edematous dilatation of interlobular septa, and lobular consolidation with purple red color. Heart was diffuse pale in color and had several irregular linear-shaped macules or patches. Histopathologically, diffuse interstitial pneumonia with the proliferation of type II pneumocytes was present in the lungs of 2 piglets. Alveolar lumens contained necrotic cellular debris derived from neutrophils and macrophages. Multifocal hemorrhage and necrotizing pneumonia with protozoan tachyzoites were observed in the lungs. Severe multifocal to confluent necrotic myocarditis, necrotic encephalitis, and necrotic adrenalitis with intralesional protozoan tachyzoites were observed in piglets. According to immunohistochemical analysis (IHC), Toxoplasma (T.) gondii tachyzoites antigens were confirmed in lung, heart, brain, and adrenal gland. And porcine reproductive and respiratory syndrome virus (PRRSV) antigens were also detected in the cytoplasm of macrophages in lungs using IHC. Based on the gross, histopathologic and immunohistochemical features, two suckling piglets were diagnosed as co-infection of T. gondii and PRRSV.

• Parasites, Hosts and Diseases
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• 제31권3호
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• pp.215-222
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• 1993

Toxoplasmngon gondii의 세포내 배양에 적합한 숙주 세포 주를 찾기 위하여 정상 세포 2종류(MDCK-canine kidney cells; Vero-monkey kidney cells) 및 암세포 6종류(A 549, PC 14-human lung cancer cells; SNU 1, SNU 16, MKN 45-human stomach cancer cells; HL-60-human promyelocytic leukemia cells)를 대상으로 하여 각 세포 주의 T.gondii 감염에 대한 감수성을 형태학적 관찰 및 3H-uracil 흡수 시험을 통하여 비교하였다. T.gondii 대한 감수성은 A 549 및 PC 14 세포가 가장 높았고, Vero, HL-60, MDCK 및 SNU 1 세포가 그 다음, SNU 16 및 MKN 45 세포는 가장 감수성이 낮았다. 또한 각 세포 주에 있어서 T.gondii 감염 후 충체증식 정도를 정량화하여 12시간, 36시간 및 60시간에 각각 측정한 바 충체 수를 적게($2{\times}10^5/ml$) 투여했을 때는 A 549, PC 14, Vero, MDCK 세포들에서 감염 60시간까지 충체의 분열 증식이 계속 증가하였고, 충체 수를 많이($50{\times}10^5/ml$) 주입하였을 때는 대부분의 세포들에서 감염 12시간에 최고의 증식을 보이다가 이후 증식이 감소하였다. 이상의 결과로 보아 기son사거 분리 계대 및 충주(strain) 확립을 위해서는 A 549 및 PC 14 세포가 가장 적합할 것으로 판단되며, 충체 주입 수 및 배양 시간별로 충체의 증식 정도가 다름을 알 수 있었다.

• Parasites, Hosts and Diseases
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• 제33권2호
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• pp.131-134
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• 1995

톡소포자충의 증식형 (tachyzoite)인 RH주를 특정 무균 마우스(specific pathogen free mouse)의 대퇴부 근육에 주입하면 복강내 계대시 보다 1-2일 더 오래 생존한다 감염 경과에 따른 서혜부 림프절의 조직병리학적 변화를 관찰하기 위하여 근육내 주입후 1일. 3일 및 5일에 동측(동측) 서혜부 림프절과 반대편 서혜부 림프절을 얻어 hematoxylin-rosin으로 염색하였다. 주입후 1-3일의 동측 림프절 조직은 피질(cortex)과 부피질(paracortex) 영역에서 배중심(verminal center)의 발달 동 (sinus)의 팽창 및 유강피세포괴(cluster of epithelioid cells)의 발달 등이 관찰되었다. 주입후 5일 째의 동측 림프절에서는 림프절 구조가 대부분 사라지고. 세포수가 감소되었을 뿐만 아니라 국소 괴사가 관찰되었다. 이 실험에서 관찰한 괴사성 림프절염은 톡소포자충에 의한 림프절염에서 기록 되지 않았던 소견으로서 사람의 괴사성 림프절염과 톡소포자충과의 원인적 관계를 시사한다.

• Parasites, Hosts and Diseases
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• 제53권2호
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• pp.155-162
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• 2015

Toxoplasma gondii is a protozoan parasite with a broad range of intermediate hosts. Chickens as important food-producing animals can also serve as intermediate hosts. To date, experimental studies on the pathogenicity of T. gondii in broiler chickens were rarely reported. The objective of the present study was to compare the pathogenicity of 5 different T. gondii strains (RH, CN, JS, CAT2, and CAT3) from various host species origin in 10-day-old chickens. Each group of chickens was infected intraperitoneally with $5{\times}10^8$, $1{\times}10^8$, $1{\times}10^7$, and $1{\times}10^6$ tachyzoites of the 5 strains, respectively. The negative control group was mockly inoculated with PBS alone. After infection, clinical symptoms and rectal temperatures of all the chickens were checked daily. Dead chickens during acute phage of the infection were checked for T. gondii tachyzoites by microscope, while living cases were checked for T. gondii infection at day 53 post-inoculation (PI) by PCR method. Histopathological sections were used to observe the pathological changes in the dead chickens and the living animals at day 53 PI. No significant differences were found in survival periods, histopathological findings, and clinical symptoms among the chickens infected with the RH, CN, CAT2, and CAT3 strains. Histopathological findings and clinical symptoms of the JS (chicken origin) group were similar to the others. However, average survival times of infected chickens of the JS group inoculated with $5{\times}10^8$ and $1{\times}10^8$ tachyzoites were 30.0 and 188.4 hr, respectively, significantly shorter than those of the other 4 mammalian isolates. Chickens exposed to $10^8$ of T. gondii tachyzoites and higher showed acute signs of toxoplasmosis, and the lesions were relatively more severe than those exposed to lower doses. The results indicated that the pathogenicity of JS strain was comparatively stronger to the chicken, and the pathogenicity was dose-dependent.

• 대한수의학회지
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• 제38권1호
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• pp.139-145
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• 1998

The Neospora sp. was isolated from the brain of 1 calf via continuous in vitro cultivation in Vero cell. Neospora tachyzoites were observed 45 days after inoculation of the homogenized brain suspension into the Vero cell. The isolated parasite (named tentatively as NCKB-1) was morphologically and ultrastructurally similar to the previously reported Neospora sp isolated in cattle (BPA-1, JPA-1). A comparison of the antigenic reactivity of cultivated tachyzoites with polyclonal antisera to Neospora caninum and Toxoplasma gondii confirmed that this protozoal isolate was similar to N caninum. This is the first report of successful isolation of Neospora sp from cattle in Korea.

• Parasites, Hosts and Diseases
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• 제48권4호
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• pp.325-329
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• 2010

Toxoplasma gondii KI-1, a recent new isolate from Korea, shows similar pathogenicity and infectivity to mice compared to the virulent RH strain. To understand characteristics of host immunity, including immune enhancement or suppression, we investigated proliferative responses and phenotypes of spleen cells. In addition, kinetics of IFN-${\gamma}$, a Th1 cytokine, was examined in BALB/c mice up to day 6 post-infection (PI). Intraperitoneal injection of mice with $10^3$ KI-1 tachyzoites induced significant decreases (P < 0.05) in proliferative responses of spleen cells. This occurred at days 2-6 PI even when concanavalin A (con A) was added and when stimulated with KI-1 antigen, suggesting suppression of the immunity. $CD4^+$ T-cells decreased markedly at day 2 PI (P < 0.05), whereas $CD8^+$ T-cells, NK cells, and macrophages did not show significant changes, except a slight, but significant, increase of $CD8^+$ T-cells at day 6 PI. The capacity of splenocytes to produce IFN-${\gamma}$ by con A stimulation dropped significantly at days 2-6 PI. These results demonstrate that intraperitoneal injection of KI-1 tachyzoites can induce immunosuppression during the early stage of infection, as revealed by the decrease of $CD4^+$ T-cells and IFN-${\gamma}$.

• Parasites, Hosts and Diseases
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• 제26권3호
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• pp.155-162
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• 1988

Toxoplasmn gondii이 강독주인 RH주와 조직내 cyst 형성주인 Fukaya주의 세포막 단배 성분을 SDS 존재하에 서 전기영동하여 분석하였다. 먼저 RH tachyzoite와 Fukaya의 cyst를 각각 마우스의 복강액과 뇌조직으로부터 분리하였는데, 불연속 Percoll density-gradient서 원심분리하여 tachygoite는 50 U와 605 Percoll용액 경계면에서, cyst는 40%와 50%의 경계면 및 50%와 60 % 경계면에서 얻었으며, cyst는 저장액으로 처리하여 bradyzoite를 얻었다. Lactoperoxidase를 촉매로 세포막에 방사성 요오드를 표지시킨 후 자가방사표지그림을 얻었을 때, bradyzoite 는 15 KDa와 14 KDa의 분자량을 가진 단백질이 주요 단백질로 나타났으며, tachyzoite에서는 30 KDa 단백질이 주요 단백질로 나타났다. 또, 당단백질의 존재를 파악하기 위해서 lectin blotting을 시행하였는데, concanavalin A는 bradyzoite에서 200K∼50KDa의 여러 단백질을, .그리고 tachyzoite에서는 52KDa 단백질을 주로 하는 33K∼20 KDa단백질을 검출하였으며, phytohemagglutinin은 두·유형에서 아무런 단백질도 검출하지 못하였다. 한편, 이들을 효소면역이적법으로 항 Fukfya항체와 항 RH항체로 반응시켰을 때, 많은 교차 반응을 보였으나, bradyzoite에서는 15 KDa 단백질이, 그리고 tachyzoite에서는 52 KDa, 30 KDa 및 25 KDa 단백 짙이 각각 유형 특이 항원 단백으로 나타났다. 위의 결과들로, bradyzoite에서는 15 KDa 단백질이 당단백질은 아니지만 특이 항원성을 갖는 주요 백으로 나타났으며, tachyzoite에서는 지금까지 주요 세포막 단백으로. 알려진 P3O외에 당단백질이며 성을 갖는 세포막 단백으로 SaKDa 단백 (gps2)을 확인할 수 있었다.

• Journal of Ginseng Research
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• 제44권5호
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• pp.704-716
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• 2020

Background: Ginsenoside Rh2 (GRh2) is a characterized component in red ginseng widely used in Korea and China. GRh2 exhibits a wide range of pharmacological activities, such as anti-inflammatory, antioxidant, and anticancer properties. However, its effects on Toxoplasma gondii (T. gondii) infection have not been clarified yet. Methods: The effect of GRh2 against T. gondii was assessed under in vitro and in vivo experiments. The BV2 cells were infected with tachyzoites of T. gondii RH strain, and the effects of GRh2 were evaluated by MTT assay, morphological observations, immunofluorescence staining, a trypan blue exclusion assay, reverse transcription PCR, and Western blot analyses. The in vivo experiment was conducted with BALB/c mice inoculated with lethal amounts of tachyzoites with or without GRh2 treatment. Results and conclusion: The GRh2 treatment significantly inhibited the proliferation of T. gondii under in vitro and in vivo studies. Furthermore, GRh2 blocked the activation of microglia and specifically decreased the release of inflammatory mediators in response to T. gondii infection through TLR4/NF-κB signaling pathway. In mice, GRh2 conferred modest protection from a lethal dose of T. gondii. After the treatment, the proliferation of tachyzoites in the peritoneal cavity of infected mice markedly decreased. Moreover, GRh2 also significantly decreased the T. gondii burden in mouse brain tissues. These findings indicate that GRh2 exhibits an antieT. gondii effect and inhibits the microglial activation through TLR4/NF-κB signaling pathway, providing the basic pharmacological basis for the development of new drugs to treat toxoplasmic encephalitis.

• Parasites, Hosts and Diseases
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• 제54권2호
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• pp.139-145
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• 2016

Toxoplasmosis is a serious disease caused by Toxoplasma gondii, one of the most widespread parasites in the world. Lipid metabolism is important in the intracellular stage of T. gondii. Stearoyl-CoA desaturase (SCD), a key enzyme for the synthesis of unsaturated fatty acid is predicted to exist in T. gondii. Sterculic acid has been shown to specifically inhibit SCD activity. Here, we examined whether sterculic acid and its methyl ester analogues exhibit anti-T. gondii effects in vitro. T. gondii-infected Vero cells were disintegrated at 36 hr because of the propagation and egress of intracellular tachyzoites. All test compounds inhibited tachyzoite propagation and egress, reducing the number of ruptured Vero cells by the parasites. Sterculic acid and the methyl esters also inhibited replication of intracellular tachyzoites in HFF cells. Among the test compounds, sterculic acid showed the most potent activity against T. gondii, with an $EC_{50}$ value of $36.2{\mu}M$, compared with $EC_{50}$ values of $248-428{\mu}M$ for the methyl esters. Our study demonstrated that sterculic acid and its analogues are effective in inhibition of T. gondii growth in vitro, suggesting that these compounds or analogues targeting SCD could be effective agents for the treatment of toxoplasmosis.