• The Plant Pathology Journal
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• v.24 no.1
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• pp.36-45
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• 2008

Studies with the transmission electron microscope were used to detect and attempt to identify viruses infecting sweetpotato (Ipomoea batatas) and other Ipomoea species. Flexuous-rods, short curved-rods, and spherical virus-like particles were observed in cells of symptomatic plants. Also, various cytopathic changes such as crystals, vesicles, fibril structures, and cylindrical inclusions were observed. The present study showed that some of these cytopathic changes were associated with some viral groups, which might be helpful in diagnosis.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.34-34
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• 2003

Classical swine fever (CSF) is a contagious disease of swine with serious economic losses in pig industry [1]. The disease is caused by CSFV which belongs to the viruses of bovine viral diarrhea (BVDV) and border disease virus (BDV) make up the Pestivirus genus within the family Flaviviridae [2]. Attenuated Korean LOM strains were used in Korea. For these reasons a practical approach for discrimination between vaccine and field strains is needed. Here, we described the deveopment of real-time RT-PCR to discriminate between vaccine strains and Korean field viruses of CSFV. (omitted)

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.109-115
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• 2002

Gene therapy is to treat and cure diseases by an introduction of therapeutic genes in defective cells or tissues of human body. Gene delivery system, gene expression system, and therapeutic gene are three core elements for gene therapy. The efficient delivery of therapeutic genes and appropriate gene expression are the crucial issues for therapeutic outcome of gene delivery. Because it can be used in common for the treatment and cure of various diseases, gene delivery system is the most important core element for a successful gene therapy. Viruses are naturally evolved to transfer their genomes into host cells efficiently. This ability has made vectorologists exploit viruses as attractive vehicles for the delivery of therapeutic genes. Viral vectors based on adenovirus (Ad) and adeno-associated virus (AAV) have been often used for gene delivery in laboratory. Ad and AAV vectors derived from human DNA viruses differ greatly in their life cycle, expression level and duration of transgenes, immunogenicity, and vector preparation. Both vectors can be used as effective tools for gene therapy and more recently in functional genomics. Here, the characteristics of Ad and AAV vectors are discussed.

• The Journal of the Korean Society for Microbiology
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• v.21 no.2
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• pp.227-231
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• 1986

The hemagglutination activities of Hantaan virus and Seoul virus were demonstrated. The hemagglutinins were prepared by sucrose-acetone extraction method from suckling mouse brains infectecd with Hantaan and Seoul viruses. Hemagglutination of goose erythrocytes by these viral hemagglutinins was pH dependent in phosphate buffer system. Hantaan and Seoul viruses were distinguished by pH range of hemagglutination. 76/118 and 79/90 strains of Hantaan virus showed hemagglutination at the range of pH 5.75-6.4 and the optimal pH was 5.75 with the titer of 1:512 in 76/118 and 1:256 in 79/90. In contrast, KSNUSD 84/34 strain of Seoul virus revealed hemagglutination at the range of pH 6.2-6.4 and the optimal pH was 6.4 with the titer of 1 : 64.

• Journal of Sericultural and Entomological Science
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• v.19 no.1
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• pp.25-32
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• 1977

The flacherie (FV) and Ina-flacherie (Ina-FV, named arbitarily) viruses of the silkworm, Bombyx mori was isolated from infectious larvae. Two types of infectious particles were purified by sucrose density gradient centrifugation. Some properties of the purified particles were investigated. Electron micrographs showed that FV and Ina-FV were spherical particles with diameters of 27nm and 20nm, respectively. The sedimentation coefficient of Ina-FV was 80S.

• Journal of Plant Biology
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• v.5 no.3
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• pp.30-36
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• 1962

The mechanism of synthesis of the toacco mosaic virus(TMV) and the potato virus X(PVX) was investigated using the methods of ultraviolet light irradiation and serological analysis. In vitro irradiation of UV on the infected tobacco juice for 10 minutes caused the infectivity of TMV and PVX to decrease markedly on their respective local lesion indicator hosts, Nicotiana glutinosa L. and Gomphrena globosa L., indicating that UV destroys directly the infectivity of the virus particles. Ten minutes after the UV was irradiated on the leaves of the two indicator hosts before inoculation, the infectivity of TMV decreased as it was irradiated in vitro, whereas that of PVX increased by 26% as compared with the unirradiated control. When the two viruses were mix-inoculated in the common host of tobacco and the synthetic products were analyzed by serological methods for a two week infection period, it was found that both viruses were multiplying more rapidly and abundantly than they were singly inoculated into the same host species. Titers from mixed series were often two times as high as those of singly inoculated series. A mechanism of competition in the synthesis between the mixed viruses in the common host is postulated.

• Korean Journal Plant Pathology
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• v.14 no.2
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• pp.130-135
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• 1998

This study was carried out to detect cymbidium mosaic potexvirus (CymMV) and odontoglossum ringspot tobamovirus (ORSV) in cultivated orchid plants in Korea. The standard double antibody sandwich enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR) were carried out for detection of the viruses in the collected orchid samples. ELISA was suitable for massive-scale diagnostic method for virus detection in orchids. RT-PCR was rapid, time-saving and reliable detective method, and detection limit data showed that RT-PCR was 103 times more sensitive than ELISA. Of the 321 individual orchids representing 5 orchids genera tested by the ELISA, CymMV and ORSV were detected in 15.6% and 22.4%, and mixed infection of the both viruses with 4.9%, respectively. Of the Cymbidium plants tested, cultivated plants showed 52.5% virus infection rate with either CymMV or ORSV and both viruses.

• Korean Journal of Microbiology
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• v.22 no.2
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• pp.85-90
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• 1984

Two viruses were isolated from kidney and spleen tissues of goldfish(Carasius auratus) and the ovarian fluid of chum salmon(Oncorhynchus keta). Both viruses replicated and produced cytopathic effect in EPC, CHSE-214, and CHH-1 cell lines at $15^{\circ}C$. The isolates were resistant to pH 3 and choloroform. Antiserum to infections pancreatic necrosis virus(IPNV) serotype VR 299 neutralized the infectivity of both of the isolates. Electron microscopy showed that the particles had typical IPNV particle morphology with average diameters of 55nm, This paper describes the first isolation of viruses infecting cultured fish in Korea.

• Biomedical Science Letters
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• v.25 no.3
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• pp.201-210
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• 2019

The oncolytic viruses selectively infect and destroy cancer cells, not harming normal cells. The cancer cell materials released by oncolysis, like tumor antigens, stimulate host antitumor immune responses, which is a long-lasting antitumor immunity removing cancer cells in remote parts of the body by a systemic response. Oncolytic viruses armed with transgenes such as cytokines or other immune stimulating factors enhance the immune responses. The first oncolytic virus approved by US-FDA is $Imlygic^{(R)}$ targeting for melanoma. The oncolytic virus is considered as a revolutionary immunotherapy for tumors together with immune checkpoint inhibitors. A variety of oncolytic viruses are under research in the treatment of kidney cancer, liver cancer, breast cancer, and many others solid tumors. Clinical trials have shown promising results in different types of cancers. Here, we present a brief introduction of various aspects of oncolytic virus, and a review of the current status of oncolytic virus therapy development.

• Research in Plant Disease
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• v.16 no.3
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• pp.326-330
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• 2010

Three pome fruit viruses, Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASPV) and Apple stem pitting virus (ASGV) were detected in pear trees (Pyrus pyrifolia) using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) in Ansung, Naju and Ulsan provinces of Korea. Infection rate of three viruses was 35.2% from 452 leaf samples of the three cultivars of pear trees. Also, each of three viruses was detected by reverse transcription polymerase chain reaction (RT-PCR) for a limited number of samples. Infection rate of three viruses was 86.3% from 233 leaf samples of the three pear cultivars. The virus infection rates by RT-PCR were much higher than ELISA. ASGV was prevailing on pear with 74.2%, whereas ASPV and ACLSV were found in 34.8% and 0.4% of tested samples, respectively. Symptoms caused by ASGV showed black spots of infected Niitaka cultivar leaves. The ACLSV, ASPV and ASGV isolates showed 83~94% sequence identity at a nucleotide level to other pome fruit virus isolates when analyzed by NCBI BLAST. Pome fruit viruses occurring in pear were ACLSV, ASPV and ASGV. This is the first report of pear trees infected ASPV in Korea.