• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.499-503
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• 1989

Relatively little is known about the antigenic relatedness of the different developmental stages of Cryptosporidium. A monoclonal antibody (mAb), an IgG3, was produced against the Cryp-tosporidium merozoite stage by immunizing mice with merozoite preparation. This monoclonal was reacted with sporozoite antigens in Western blotting resulting in recognition of an epitope on a 3.5-kDa antigen. An immunoelectron microscopic technique was used to investigate the antigenic relatedness of Cryptosporidium Sporozoites and merozoites. Mouse intestine was fixed with 1 ％ glutaraldehyde and embedded in LR White. Thin sections were then sequentially treated with murine IgG3 mAb and anti-mouse IgG conjugated to 15-nm diameter colloidal gold. This mAb showed similar (sur-face/cytoplasmic) immunoelectron microsropic colloidal gold labeling patterns with sporozoites and merozoites, indicalting epitope sharing between these two stages. This information might be useful for identifying possible epitopes to which a vaccine could be developed.

• Korean Journal of Veterinary Research
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• v.34 no.1
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• pp.135-139
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• 1994

In the year 1992/93 leucocytozoonosis could be first diagnbosed in 87 chickens of 4 chicken farms in Honam districts. The diagnosis was confirmed by detection of the blood merozoites or gametocytes and histological finding of the schizonts from various organs with some clinical signs. Cases of leucocytozoonosis only occurred from the end of June to the middle of September. Artificial infection could be observed by means of inoculation of infected blood merozoites. The schizonts were found in the liver and cardiac muscle of the different chickens recovered from the natural infection, respectively, in September and next February. Thus the relapse or long-term infection in cold seasons might be possible. The unique gametocyte antigen polypeptide was 50.1 kD.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.387-394
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• 1994

To make the genomic DNA probe of Theileria sergenti, the merozoites were purified from bovine erythrocytes. The infected erythrocytes were lysed by Aeromonas hydrophila(Ah-1) hemolysin, and the parasites were isolated by ultracentrifugation on a Percoll discontinuous density gradient. For construction of a T sergenti genomic DNA library, T sergenti DNA was digested with Pstl and the fragments were ligated into the PstI site of pUC19 before transformation of Escherichia coli JM83. Out of thousands of transformants obtained by transformation of E coli JM83 with the genomic library, three plasmids were chosen. The sizes of the inserted DNAs were 2.9kb(2.4kb and 0.5kb) in pKTS1, 4.3kb in pKTS2 and 1.5kb in pKTS3, respectively. The DNA fragments used as probe KTS1(2.4kb), KTS2(4.3kb) and KTS3(1.5kb) were labeled digoxigenin-11-dUTP for the Southern hybridization. In Southern hybridization, all of the probes(KTS1, KTS2 and KTS3) reacted specifically to T sergenti DNA, but not to bovine leucocyte DNA. In order to find out the sensitivities of the digoxigenin-11-dUTP-labeled KTS1 and KTS3 as the probes, purified merozoite DNA and bovine DNA (control) were checked by dot blot hybridization with the probes. Both of the probes, KTS1 and KTS3, detected as minimum amount of 975pg of the T sergenti DNA, but not bovine DNA even to 500ng.

• Journal of the korean veterinary medical association
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• v.46 no.3
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• pp.245-263
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• 2010

말 원충성척수뇌염(equine protozoal myeloencenphalitis; EPM)은 말에게 심각한 신경성 질병을 일으키는 원충성 질병으로서 Sarcocystis neurona가 원인체이다. 근육포자낭(sarcocyst)을 숨기고 있는 자연중간숙주를 포함한 S. nuerona의 완전한 생활사는 알려져 있지 않으나 주머니쥐의 일종인 opossum(Didelphis virginiana, Didelphis albiventris)이 최종 숙주이며, 말은 정상적 숙주로 알려져 있다. 왜냐하면 말에서는 분열체(schizonts)와 분열소체(merozoites)가 발견되기 때문이다. EPM 유사 질병들이 고양이, 밍크, 너구리, 스컹크, 태평양 점박이 바다표범, 포니, 바다수달 등을 포함한 다양한 포유류에서 발생한다. 고양이는 포자낭(sporocytes) 섭식 후 근육포자낭 단계를 숨기는 실험적인 중간숙주로서 역할을 할 수 있다. 최근 국내에서 신경증상을 나타내는 말에 대한 의심스러운 임상증상이 임상수의사들에 의해 관찰되어졌는, 정확한 진단을 하기위하여 S. nuerona에 의해 발생된 EPM의 역사, 구조, 생활사, 생물학, 병리론, 동물에서 질병 유도, 임상 증상, 진단, 병인론, 생태학, 치료 등에 대하여 알아보고자 한다.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.595-599
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• 2009

Sarcocystis grueneri-like sarcocysts were found from the cardiac muscles of a rearing red deer (Cervus elaphus) carcass in Korea. In the light microscopical examination of sarcocysts, they were oval to spherical cysts and 90-170$\times$110-380 ${\mu}m$ in size. However, there was no inflammation and myofiber degeneration. In the transmission electron microscope, these cysts were located within the sarcoplasm of the host cell and filled with merozoites. The sarcocysts were enclosed by a very thin wall (0.45-0.6 ${\mu}m$ thick) that consists of protrusions and ground substance. The primary cyst wall formed numerous strip-like protrusions which were 0.2-0.3 ${\mu}m$ wide and up to 4.2 ${\mu}m$ long. The protrusions were running in parallel with the surface of the cyst. A characteristic of the cyst wall was absent of fibrils inside the protrusions. Merozoites in the compartment measured about $15\times4\;{\mu}m$. The merozoite consisted of four regions: micronemes and rhoptries, amylopectin granule, nucleus, and amylopectin granules. The number of rhoptry was counted in 7-13.

• Korean Journal of Veterinary Research
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• v.48 no.2
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• pp.197-201
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• 2008

Plasmodium spp. in domestic and wild birds are microscopic, intracellular parasitic protozoa within the blood cells and tissues cause avian malaria. A 17-month-old Magellan penguin (Spheniscus magellanicus) with a clinical signs of anorexia, depression, and respiratory distress for 3 days was submitted to the Pathology Department of Veterinary Medicine, Cheju National University in October 2005. It was born and reared in the Jeju Island. Grossly, the liver was enlarged, pale and friable. The spleen was also enlarged with dark red coloration and friable. Histopathologically, the lesions in the liver were characterized by multifocal infiltration of macrophages and lymphocytes especially in perivascular regions. The schizonts of Plasmodium spp. contained up to 30 merozoites were found in numerous infiltrated mononuclear cells. Similarly, histiocytic cells were proliferated in red pulp of spleen and the schizonts were found in these cells. Numerous dark brown pigments were widely distributed in the liver and spleen. The result of the nested polymerase chain reaction clarified the causative agent of this case was Plasmodium spp.. This is the first report for the outbreak of avian malaria caused by Plasmodium spp. in a penguin that was born and reared in Jeju Island in Korea.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.465-471
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• 1990

The fine structure of the inoculated Theileria sergenti on the splenectomized Korean native cattle was observed to delineate the morphological. characteristics with transmission and scanning electron microscope. The cattle was inoculated with 1.5ml cryopreserved stabilate ($5.63{\times}10^6/{\mu}l$, PE 3%). At peak parasitemia (40%), infected blood was collected, washed and then T sergenti was observed. Scanning electron micrograph of the erythrocytes infected with T sergenti appeared various irregular from involving specific swelling, and abnormal projections like acantocyte, echinocyte and knizocyte. Transmission electron microscopic studies of T sergenti showed that piroplasm possess intracytoplasmic food vacuole, rhoptries and tubule. Merozoite, $0.6{\sim}1.81{\mu}m$ to $0.4{\sim}1.21{\mu}m$ in length, surrounded by 10~15nm thickness of pellicula. which is surrounded by a single unit membrane. Various size of veil which was observed in stroma of erythrocytes infected with T sergenti, located at the proximate part of the merozoite. The merozoite multiplied by means of binary fission so that two and more oval-like merozoites in the stroma of infected erythrocyte could be observed.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.189-194
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• 1997

The life cycle of Theileria sergenti(T sergenti) in cattle, especially Korean native cattle, was not proved clearly. To find schizont stage in the life cycle of T sergenti in Korean cattle, T sergenti schizonts in the cells of parotid lymph nodes from 10 adult Korean cattle were examined. Lymphoid cells which were separated from these lymph nodes were cytocentrifuged to observe the parasites in the cells. T sergenti schizonts were detected in the cells of lymph nodes of 6 cattle out of them by IFA(Indirect Fluorescent Antibody) test and Giemsa stain. By peroxidase stain, the cells which contain schizonts were proved lymphoid cells. T sergenti schizonts identified by IFA test were able to be restained by Giemsa stain. Also, merozoites were observed in peripheral blood of the same 6 cattle that had schizonts, by giemsa stain, but not observed in the 4 cattle that had not been detected schizonts. As a part of life cycle of T sergenti, schizonts were observed in the lymphoid cells of Korean cattle.

• Parasites, Hosts and Diseases
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• v.31 no.3
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• pp.223-230
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• 1993

Monoclonal antibodies (Ub) against merozoites and sporozoites of the protozoan parasite Cryptosporidium pcnjum were examined for potential modulation of cryptosporidial infections in vivo by daily oral Ub administration to oocyst-inoculated neonatal mice. Monoclonal-treated neonatal mice were sacrified four and eight days post infection (pi) . Differences in infection rates were observed among the treatment groups at the p < 0.05 level. Suckling mice treated daily with orally administered mixtures of mAbs( ascitic fluids) showed significantly reduced parasite loads compared to control mice at flour and eight days pi, while suckling mice receiving mAb Cmg-3 alone showed signiacant differences only at 4 days Pi., suggesting that passive transfer of mAb may be of value in controlling cryptosporidial infections.

• Parasites, Hosts and Diseases
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• v.51 no.2
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• pp.207-212
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• 2013

Chronic diarrhea with a 35 kg weight loss (75 kg to 40 kg) occurred during 2 years in an alcoholic patient was diagnosed with Isospora belli infection in the Republic of Korea. The patient, a 70-year old Korean male, had been a heavy drinker for more than 30 years. He was admitted to the Seoul National University Hospital because of long-standing diarrhea and severe weight loss. He had an increased white blood cell (WBC) count with high peripheral blood eosinophilia (36.8-39.9%) and lowered protein and albumin levels but without any evidence of immunosuppression. A parasitic infection was suspected and fecal examination was repeated 3 times with negative results. Peroral endoscopy with mural biopsy was performed in the upper jejunum. The biopsy specimens revealed villous atrophy with loss of villi together with various life cycle stages of I. belli, including trophozoites, schizonts, merozoites, macrogamonts, and microgamonts. The patient was treated successfully with oral doses of trimethoprim 160-320 mg and sulfamethoxazole 800-1,600 mg daily for 4 weeks. A follow-up evaluation at 2.5 years later revealed marked improvement of body weight (68 kg), increased protein and albumin levels, and normal WBC count with low eosinophils (3.1%). This is the first clinical case of isoporiasis with demonstration of various parasitic stages in the Republic of Korea.