• Journal of Sericultural and Entomological Science
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• v.32 no.1
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• pp.49-57
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• 1990

To investigate the pathway of Nuclear Polyhedrosis Virus(NPV) of Bombyx mori in early stage infection of 2nd instar larva, the larval tissues were observed under electron microscope at interval of 6, 12, 24, and 48 hours after virus inoculation. The results are as follows. 1. The intact and enveloped nucleocapsids released from the polyhedra protein in the gut lumen apparently entered with the microvilli. 2. Virus progenies were observed in columnar cell nuclei 24 hours after inoculation, but polyhedra was not seen. The enveloped virus was observed in some of the intercellular spaces between mid-gut cells. 3. Many enveloped virus particles appeared in the basement membrane. These enveloped virus particles passed the basement membrane and gathered at blood cells in heomocoeal. 4. The NPV muliplicates in nuclei of the blood cells and the tracheal cells normally.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.279-286
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• 2015

Cotesia plutellae bracovirus (CpBV) is a polydnavirus symbiotic to C. plutellae parasitizing young larvae of the diamondback moth, Plutella xylostella. Several CpBV genes play important roles in suppressing immune responses of the parasitized larvae. This study tested a hypothesis that the CpBV genes inducing host immunosuppression could be applied to develop a potent recombinant baculovirus. Based on a previous study, a recombinant baculovirus expressing CpBV-ELP1 (AcMNPV-ELP1) was selected and multiplied using larvae of the beet armyworm, Spodoptera exigua. The recombinant viruses were produced in a yield of $5{\times}10^{10}$ polyhedral inclusion body (PIB)/larva. The cultured AcMNPV-ELP1 exhibited a much higher pathogenicity against S. exigua larvae. However, its insecticidal activity was varied among larval instars of S. exigua, in which first and late instars were high susceptible. Spray of the recombinant baculovirus ($5{\times}10^6PIB/mL$) exhibited higher control efficacy (${\approx}$ 88%) against S. exigua larvae infesting cabbage than a chemical insecticide, tebufenozide, at 7 days after treatment. These results indicate that AcMNPV-ELP1 mass-cultured using host insect system is highly pathogenic and can be applied to develop a novel microbial control agent.

• Journal of Life Science
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• v.30 no.3
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• pp.221-229
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• 2020

Distylium racemosum is an evergreen tree growing wild on Jeju Island, which has been reported to exert biological activity. Obesity is induced by genetic, metabolic, environmental, and other factors. Among these, certain bacterial and viral infections have been shown to cause obesity, which is known as infectobesity. Human adenovirus (HAdV)-36 is one of the viruses that are known to cause infectobesity in humans. Unlike extensive research on preventing obesity and developing anti-obesity drugs, little research has been conducted specifically on the prevention and treatment of infectobesity. Therefore, this study aimed to evaluate the effects of phytochemicals from D. racemosum on the replication of HAdV-36. A549 cells infected with HAdV-36 were treated with an ethyl acetate fraction of a D. racemosum leaf extract (DRE), and the virus titer was calculated based on the hemagglutination (HA) titer. The results showed a concentration-dependent inhibitory effect of DRE treatment on HA titers. DRE treatment was also found to inhibit the cytopathic effects of the virus and the expression of viral genes. Quercitrin was identified as the constituent of DRE exerting an inhibitory effect on HAdV-36 replication. This study shows that DRE can be used as a candidate substance for the development of treatment for HAdV-36 infections. In addition, this study provides a basis to further investigate DRE for the development of anti-infectobesity medication.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.638-642
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• 2012

Human pathogenic viruses such as hepatitis A and E virus (HAV and HEV), which lead to acute liver failure and death, are foodborne pathogens associated with the consumption of virus-contaminated meats, filter-feeding bivalves, fruits, and salads. Two of the three swine farms examined in this study had HAV and HEV positive stool samples in a nested RT-PCR assay. The use of the immunomagnetic separation (IMS) facilitated the separation of HAV through interactions between the ligand on the virion surface and the antibody from the swine feces containing both HAV and HEV. The nested RT-PCR analysis was performed for the detection of HAV obtained from hepatocarcinoma cell line (PLC/PRF/5) contaminated with eluent fraction of IMS. This indicated that IMS has the potential to simultaneously isolate and concentrate target viruses by changing antibodies linked on the magnetic beads.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.321-326
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• 1994

Korean isolate, porcine epidemic diarrhea virus (KPEDV-9) was adapted through serial passages in vero cell. The viral yield reached up to $10^{5-6}$ $TCID_{50}/ml$ at the passage level of 90th. The cell adapted virus was characterized through genetic and morphological examinations. The RNA extracted from virus infected cell revealed the presence of RNA band with molecular size of >20Kb. The electron microscopic examination on purified virus showed the pleomorphic appearance of enveloped particles with 5-10nm surface projections, which fit with the shape of coronavirus. The etiological survey on swine diarrhea by immunofluorescence test(FA) indicated 17.5% positive rate on the PEDV infection. In addition, the incidence were detected both in piglets within two weeks old as well as fattening pigs. Serological survey by ELISA revealed the overall 45% positive result, thus, indicating the PEDV infection are widespread throughout this country.

• Journal of Life Science
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• v.34 no.6
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• pp.408-417
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• 2024

It was confirmed whether PB-81, a 50% ethanol extract of Daphne genkwa (Siebold & Zucc), had an inhibitory effect on virus proliferation in bovine rotavirus and a therapeutic effect on bovine diarrhea disease. The results showed that PB-81 induced the interferon beta in A549 cells, an epithelial cell line and interferon gamma in NK92 cells, a blood cell line. Furthermore, to confirm the viral proliferation inhibitory effect of PB-81, PB-81 was administered to MBDK cell line before, during, and after infection. Result shows that the virus was suppressed in all cases where PB-81 was administered, and the best virus suppression effect was achieved when PB-81 was administered before virus infection. In the toxicity test in mice, no side effects due to toxicity were observed, even at a maximum dose of 20 mg/mL. To verify the therapeutic effect on 16 cattle with bovine rotavirus diarrhea and 4 cattle in the control group, PB-81 was administered at a dose of 20 mg/5 mL, and No fatality was observed during the treatment. The average recovery duration from the initial administration of PB-81 was 2.25 days in the PB-81 administration group and 6.5 days in the control group without PB-81 administration. No side effects were observed from the tested cattle with rotavirus diarrhea.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.417-423
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• 1997

돼지 생식기 호흡기 증후군 바이러스의 nucleocapsid와 반응을 하는 SDOW17 단크론항체를 이용하여 중성 포르말린에 고정시킨 자연감염된 포유자돈의 폐장에서 면역조직화학법을 이용하여 돼지 생식기 호흡기 증후군 바이러스 항원을 확인하였다. 서울대학교 수의과대학 병리학교실에 의뢰된 포유자돈들 중에서 병리조직학적으로 폐장에서 간질성 폐렴이 관찰된 포유자돈 7두를 임의로 선택하여 본 실험을 실시하였다. 간질성 폐렴의 병변으로 많은 수의 대식세포 침윤을 동반한 폐포벽 두께의 증가와 제II형 폐포세포의 비후가 관찰되었다. 검사한 7두 포유자돈중에서 6두에서 돼지 생식기 호흡기 증후군 바이러스에 대한 항체를 enzyme-linked immunosorbent assay에 의해 확인하였다. SDOW17 단크론항체를 이용한 면역조직화학염색과 간질성 폐렴의 대식세포에서 돼지 생식기 호흡기 증후군 바이러스의 항원을 검출하였고, 항원은 (주로)대식세포의 세포질에서만 진한 갈색의 양성반응이 관찰되었다. 이상 검사결과 돼지 생식기 호흡기 증후군 바이러스는 폐장의 간질과 폐포강에 분포되어 있는 대식세포에서 주로 증식하는 것으로 판명되었다. 본 실험에서 사용한 면역조직화학법은 돼지 생식기 호흡기 증후군 바이러스 감염여부를 바이러스 분리 또는 혈청검사 없이 진단하는데 사용할 수 있는 유용한 진단방법으로 판명되었다.

• Korean journal of applied entomology
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• v.8
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• pp.7-9
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• 1969

거의 모든 국가에서 생산된 씨감자는 감자바이러스 이병율을 검사해서 합격품만을 농민에 분배하고 있다. 우리나라는 딴 씨감자 생산국과는 사정이 달라 고령지에서 씨감자를 생산하고 있는 관계로 감자밭의 필수는 전국적으로 막대한 수에 달한다. 우리나라에서의 감자바이러스 김정은 원원종에 한하고 있으나 농민에 분배되는 씨감자도 바이러스 검정을해서 합격품만을 나누어주어야 국가의 체면이 서겠다. 그러나 현재의 시설로는 이를 감당 할 수 없어 이에 대치 될 만한 실제적 방법의 하나로 매개진딧물 밀도와 감자바이러스 이병율간의 상관관계를 밝혀 번잡한 바이러스 검정법 대신 매개진딧물의 공중밀도를 조사하여 해지점의 감자바이러스 이병율을 추산 할 목적으로 본 시험에 착수하였다. 본 보고에서는 진딧물조사 결과만을 발표하고 18개소에서 행한 포장시험결과는 1970년에 행할 바이러스 검정을 마치면 종합결과를 발표 할 예정이다. 표 1에서와 같이 서해안, 내륙, 및 대관령에서의 매개진딧물과 일반진딧물의 수는 각각 8/31, 179/680 및 50/237이었으며 필자가 행한 1967, 1968년의 조사성적을 뒷받침하는 결과를 얻었다. 이에 필자는 씨감자 부족량 약 60,000톤의 조속한 충족을 위해 씨감자의 증식 단계에서는 서해안 일모작 답을 환용 할 것을 다시 한번 강조하는 바이다.

• Korean Journal Plant Pathology
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• v.12 no.4
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• pp.432-436
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• 1996

역전사 중합효소 연쇄반응(RT-PCR)을 이용하여 담배(Nicotiana glutinosa)에 증식시킨 7종의 오이 모자이크 바이러스(CMV)를 검정하였다. RT-PCR을 위한 간단하고 신속한 바이러스 핵산의 조즙액 추출법이 개발되었으며, CMV 외피단백질 유전자 부위를 기초로 하여 제작한 20개의 염기로 구성된 primer를 사용하여 RT-PCR을 실시한 결과, 약 490 염기쌍의 DNA 단편들이 이병식물의 조즙액으로부터 증폭되었다. EcoRI 및 MspI을 이용한 RT-PCR 산물의 분석에 의하여, 공시한 7종의 바이러스는 모두 CMV subgroup I으로 동정되었다. Ouchterlony 한천젤 이중 확산법을 이용한 항혈청 검정에서도 7종의 바이러스 모두 CMV-Y의 항혈청과 단일의 침강선을 형성하였다.

• Korean Journal of Plant Tissue Culture
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• v.28 no.6
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• pp.335-339
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• 2001

Grapevine leafroll-associated 3 closterovirus (GLRaV-3) is phloem limited virus, and one of the most severe viral diseases found in Korea. However, nonhomogenous distribution and low concentration and seasonal variations of GLRaV-3 in grapevines remain as main problems which prevent the introduction and molecular biology or serology experiments. Virus-infected plantlet in vitro was obtained from node tissue cuttings, which was GLRaV-3 infected 'kyoho' vines. The amount of purified virus was highest in vitro plantlet. Moreover, viruses seem to be relatively homogeneously distributed in all organs including leaf, stem and callus derived from in vitro plantlets. RT-PCR detection using in vitro plantlet tissue as template was most effective. When comparing ELISA to RT-PCR, RT-PCR detection was 1,000 times as effective as ELISA. These results can be explained by improved quality such as tenderness or less tannins in plantlet in vitro. In conclusion, until infected herbaceous host will be available, tissue culture can be usefully adopted as a technique for a good source of GLRaV-3 closterovirus for further studies.