• Parasites, Hosts and Diseases
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• 제39권4호
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• pp.285-292
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• 2001

The present study aimed to evaluate control efficacy of clonorchiasis by two schemes of repeated treatment with praziquantel at two endemic villages in China. Residents of one village at Guangxi Autonomous Region were treated and examined 6-monthly and of another at Liaoning Province 12-monthly, In residents that took 25 mg/kg x3 (total 75 mg/kg) of Praziquantel every 6 months for one Year the e99 Positive rate showed a significant drop from 69.0% to 17.1%. In contrast, a group of same praziquantel medication once showed a slight marginal decrease in the egg rate from 18.9% to 12.2% after one year Of 39 subjects examined 3 times, 56.4% were cured, 7.7% persistently positive, one (2.6%) reinfected after cure or newly infected, but 25.6% were persistently negative. The present finding suggests that 6-monthly medication with 75 mg/kg of praziquantel should effectively lower the prevalence but incomplete for control of clonorchiasis in heavy endemic areas.

• BMB Reports
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• 제36권1호
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• pp.138-143
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• 2003

Of many viral causes of human cancer, few are of greater global importance than the hepatitis B virus (HBV). Over 250 million people worldwide are persistently infected with HBV. A significant minority of these develop severe pathologic consequences, including chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). Earlier epidemiological evidence suggested a link between chronic HBV infection and HCC. Further, the existence of related animal viruses that induce acute and chronic infections of the liver, and eventually HCC, confirms the concept that HBV belongs to one of the few human oncogenic viruses. Although it is clear that chronic HBV infections are major risk factors, relatively little is understood about how the viral factors contribute to hepatocarcinogenesis. This review will introduce molecular aspects of the viral infection, and highlight recent findings on the viral contribution to hepatocarcinogenesis.

• 한국임상수의학회지
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• 제26권5호
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• pp.463-466
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• 2009

A swine farm located in the Kyungpook province (designated as farm D that have been suffering from PED for several years was selected to study the etiology and the outbreak pattern of PED by clinical and laboratory examinations. Clinical examination indicated that sows exhibited signs of mastitis resulting in an inadequate transfer of lactogenic immunity against PEDV to newborn piglets. Furthermore, serological tests revealed that all sow groups and their piglets had low levels of anti-PEDV antibody. These data suggest that improper vaccination program has been indeed performed in this farm. Remarkably, despite no symptoms of PED in weaners, the presence of PEDV was identified by RT-PCR from fecal samples of weaning piglets, indicating persistent PEDV circulation in the herd. Based on these results, the following basic control schemes were executed for the control of PEDV circulation in the farm; a) A quick removal of affected pigs and disinfection of affected sheds. b) restructuring of vaccination program and employment of consultant. c) prompt treatment of mastitis and removal of poor lactogenic sows, and d) enhancement of biosecurity of farrowing house by acquisition of additional space. We evaluated risk factors and implementation of control measures in two months and were unable to found any case related to PEDV infection. Taken together, our data indicate that the method described above is effective for the control of PED outbreak in farm persistently suffering from PEDV infection.

• 대한수의학회지
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• 제32권1호
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• pp.77-82
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• 1992

세포 비병원성 소 설사병 바이러스가 감염된 우태아 폐세포를 이용 바이러스를 순수분리하여 이화학적 성상을 검사하였던 바 다음의 결과를 얻었다. 바이러스의 비중은 $1.090{\sim}1,114gm/cm^3$로 검출되었으며 $1,098gm/cm^3$에서 최대 감염가를 나타내었다. 면역 전자현미경을 이용한 형태학적 분석결과 30~80nm의 바이러스성 입자를 관찰할 수 있었으며 유전인자의 추출 분석결과 병원성 바이러스와의 전기영동상 유전자 규모에 있어서 차이는 인정되지 않았다. 그러나 비세포 병원성 소 설사병 바이러스는 병원성 바이러스에 비하여 세포외 배출이 적었으며 세포내에서 보다 많이 존재하는 것으로 관찰되었다.

• 미생물학회지
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• 제38권3호
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• pp.221-229
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• 2002

일본뇌염바이러스(Japanese encephalitis virus, JEV) Nakayama strain을 초기 multiplicity of infection 5.0으로 Vero세포에 감염하여 1년 이상 안정적으로 바이러스를 방출하는 지속감염(persistently-infected)세포주를 확립하였다. 지속감염 세포에서 지속적으로 방출되는 총 11 개의 Plaque 형태 변이바이러스(morphology mutants)클론을 확보하였다. 분리된 변이바이러스의 복제효율을 분석한 결과 생물학적 표현형과 복제효율은 유의하게 상관하였다. 변이바이러스 RNA 게놈 양 말단의 non-coding region 및 envelop 단백질의 ORF에서는 유의한 염기서열 변화가 관찰되지 않아 JEV 약독화에 새로운 인자가 추가로 관여할 가능성을 제시하였다. 변이바이러스에 감염된 신선한 Vero세포는 wild-type JEV의 일반적 감염성상과 다르게 대다수의 세포가 유의할 만한 세포병변현상을 나타내지 않았다. 감염된 Vero세포에서 wild-type JEV 및 large plaque을 형성하는 변이바이러스의 경우 mRNA와 함께 Bcl-2의 발현은 모두 유의하게 감소하였으며 p53은 뚜렷하게 증가하였다. 반면 small plaque을 형성하는 변이바이러스의 감염세포에서는 Bcl-2와 p53 모두 유의한 변화를 볼 수 없었다. 이상의 결과들과 함께, 감염된 Vero세포의 internucleosomal DNA fragmentation과DNA profile의 유형분석에 따르면 궁극적 인 세포병변효과의 변화는 변이바이러스의 복제효율과 더불어 p53에 비의존적인 apoptosis 수위의 전반적인 감소에 기인하는 것으로 판단된다.

• Molecules and Cells
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• 제43권5호
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• pp.469-478
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• 2020

Hepatitis C virus (HCV) propagation is highly dependent on cellular proteins. To identify the host factors involved in HCV propagation, we previously performed protein microarray assays and identified the LIM and SH3 domain protein 1 (LASP-1) as an HCV NS5A-interacting partner. LASP-1 plays an important role in the regulation of cell proliferation, migration, and protein-protein interactions. Alteration of LASP-1 expression has been implicated in hepatocellular carcinoma. However, the functional involvement of LASP-1 in HCV propagation and HCV-induced pathogenesis has not been elucidated. Here, we first verified the protein interaction of NS5A and LASP-1 by both in vitro pulldown and coimmunoprecipitation assays. We further showed that NS5A and LASP-1 were colocalized in the cytoplasm of HCV infected cells. NS5A interacted with LASP-1 through the proline motif in domain I of NS5A and the tryptophan residue in the SH3 domain of LASP-1. Knockdown of LASP1 increased HCV replication in both HCV-infected cells and HCV subgenomic replicon cells. LASP-1 negatively regulated viral propagation and thereby overexpression of LASP-1 decreased HCV replication. Moreover, HCV propagation was decreased by wild-type LASP-1 but not by an NS5A binding-defective mutant of LASP-1. We further demonstrated that LASP-1 was involved in the replication stage of the HCV life cycle. Importantly, LASP-1 expression levels were increased in persistently infected cells with HCV. These data suggest that HCV modulates LASP-1 via NS5A in order to regulate virion levels and maintain a persistent infection.

• 한국동물위생학회지
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• 제45권3호
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• pp.211-219
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• 2022

Bovine viral diarrhea (BVD) is one of the problematic wasting diseases in cattle leading to huge economic losses. This study was conducted to investigate the prevalence of BVD including transient and persistent infection from cattle farms in Gyeongsangnam-do. A total of 2,667 blood samples from 24 farms were collected and the sera were subjected to ELISA to detect BVD virus (BVDV) antigen, E^rns. 5' untranslated region (5'-UTR) of BVDV-positive samples was sequenced to identify the genotype, and compared with isolates previously reported elsewhere. There were fourteen BVDV-positive calves from 2,667 samples (positive rate: 0.52%) from first ELISA testing followed by eight persistently infected out of eleven BVDV-positive samples (72.73%) in secondary ELISA that was conducted in at least four weeks suggesting the circulation of BVDV in the area. Sequencing analysis exhibited that thirteen BVDV-positive samples were identified as BVDV-1b and one sample was BVDV-2a. Phylogenetic analysis revealed that the BVDV-1b-positive samples showed the highest homology in nucleotide sequence to Korean isolates collected from Sancheong, Gyeongsangnam-do, while the BVDV-2a-positive sample (21GN7) was more similar to reference strains collected outside South Korea. This study will provide the recent fundamental data on BVD prevalence in Gyeongsangnam-do to be referred in developing strategies to prevent BVDV in South Korea.

• 대한수의학회지
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• 제63권2호
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• pp.12.1-12.7
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• 2023

Bovine viral diarrhea virus (BVDV) is an RNA virus belonging to Pestivirus in the family Flaviviridae. BVDV has economic significance for the livestock industry because of its association with acute disease, fetal loss, and birth of persistently infected (PI) animals. This study aimed to investigate the BVDV infection rates in Korean native cattle farms in Jeju for further planning of a BVDV control program in the Jeju Province. BVDV antibodies and antigens were tested in 15,842 sera collected from 302 Korean native cattle herds between January 2014 and June 2017 using enzyme-linked immunosorbent assay (ELISA). Viral antigen was detected by reverse transcription-polymerase chain reaction from 60 sera that were antigen ELISA-positive. BVDV antibodies were found in 90.7% (274/302) herds and 61.1% (9,678/15,842) cows. BVDV antigens were found in 13.2% (40/302) herds and 0.4% (61/15,842) cows. The oldest animal group (> 8 years) exhibited the highest sero-positive rates (91%), while the youngest animal group (< 1 years) had the highest antigen positivity rates (0.52%). Of the 60 antigen-positive sera, BVDV types 1 and 2 were found in 36 and 12 sera, respectively. Additionally, six animals were considered to be PI as BVDV was continually detected in annual examination.

• Parasites, Hosts and Diseases
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• 제22권2호
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• pp.153-160
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• 1984

마우스에 대한 요꼬가와흡충 실험감염에 있어서 충체회수률 등 감수성(susceptibility)이 실험자에 따라 매우 다른 것으로 보고되어 있다. 저자등은 이것이 마우스 strain에 따른 차리일 것으로 생각하고 이 연구를 통하여 확인하고자 하였으며, 또 prednisolone 주입으로 숙주의 면역반응을 저하시킬 때 충체회수률이 어떻게 변동하는가를 관찰하고자 하였다. 요꼬가와흡충 피낭유충은 은어의 근육으로부터 분리한 것을 사용하였으며 마우스 5개 strain (A,DBA,CBH,CSTBL,KK) 총 60마리에 대해서 300개씩의 피낭유충을 감염시키고 1주일 후에 도살하여 충체회수률 및 충체의 크기를 측정하였다. 또 ICR계 마우스 29마리에는 각각 1,800개씩의 피낭유충을 감염시키되 그중 15마리에 대해서는 감염 1주전부터 도살시까지 격일로 prednisolone l0mg/kg를 주입하였고 각각 감염 6시간부터 35일까지의 충체회수율을 관찰하였다. 결과는 다음과 같다. 1. 마우스 5개 strain에 있어서 감염성공률은 25.0∼83.3%의 범위에서 차이를 보였고, 충체국수률은 1.2∼18.9%, 나수충체의 크기는 평균 길이 0.554∼0.683mm, 폭 0.214∼0.244mm이었다. 이들 수치는 KK 및 CSTBL strain에서 다른 3가지 strain보다 높았으며 유의한 차리를 보였다. 2. ICR계 마우스에서 시간별로 관찰한 충체회률은 감염 1일이내에는 38∼66%의 높은 율을 보였으나 1일 이후에는 35일까지 0.7%이하의 낮은 회수률을 보였다. 그러나 prednisolone을 투여한 군에서는 감염후 21일까지도 16∼80%의 높은 충체회수률을 유지하였다. 이상의 결과로 미루어 보아 마우스는 strain에 따라 요꼬가와흡충 감염에 대한 감수성이 다르다 것을 알 수 있었다. 또한 감수성이 낮은 ICR계 마우스도 prednisolone을 주입하면 감염 3주까지 높은 충체회수률을 얻을 수 있음을 알게 되었다.

• 한국동물위생학회지
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• 제40권3호
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• pp.201-208
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• 2017

소에 있어서 BVDV는 반추류에서 중대한 감염을 야기하여 번식장애, 설사 및 유량감소를 야기하여 농가에 막대한 피해를 야기하고 있다. 특히 지속감염우의 확인과 도태는 농가 내 감염원을 제거하는 중요한 일이나 아직까지 PI개체의 바이러스의 감염과 전파에 관한 연구는 미진한 것으로 추정된다. 본 연구에서는 도입된 수컷에서 PI를 확인하였으며 전혈 검사를 실시 하면, PI 혈액 성상에서 림프구가 낮게 관찰되며 전체 WBC의 수는 정상범위에 속하나 낮게 나타나는 것을 알 수 있었다. PI 수컷에서 생산된 정액은 정자 수가 매우 낮으며, 신선 정액의 생존성도 불량한 것으로 조사되었다. 정자 기형율 또한 증가되었으며 특히 공포와 중편부의 소적을 가진 기형정자의 비율이 높았다. PI수컷은 나이가 들수록 정액 성상이 불량하여 불임화되었고 이는 BVDV가 정소의 정자 생산능력을 낮추어 사출된 정액내 정자수 감소 현상을 야기한다는 것을 알 수 있었다. 그럼에도 불구하고 확인된 PI 개체에 의한 전체군의 감염 현상은 관찰할 수 없었는데, 이는 적절한 백신 프로그램에 의하여 PI에 의한 간접적인 전파의 위험성이 낮다고 판단된다.