• Journal of fish pathology
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• v.7 no.1
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• pp.13-22
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• 1994

To identify the immunogens of a PRT strain of Infectious Hematopoietci Necrosis Virus (IHNV) isolated from cultrued fish in Korea (Park et al, 1993). a panel of 4 monoclonal antibodies (MAbs) against IHNV-PRT strain and two polyclonal antisera from rainbow trout survived IHN disease were prepared. Proteins of purified IHNV-PRT strain were analysed on 10% SDS-PAGE and transferred onto NC paper and were incubated with the antibody solutions. With the polyclonal antibodies, four bands ($M_1$, $M_2$, G and 90Kd) were detected and the band density was in the order of $M_2$ > 90Kd > $M_1$ > G. However, with the MAbs, only two bands(G and 90Kd) were detected. The origin of 90Kd protein was not clear but maybe cell. All the results represented that among the five proteins of IHNV-PRT strain (Park et al., 1993), $M_2$, $M_1$ and G proteins were immunogens and $M_2$ protein was the strongest one.

• Pediatric Infection and Vaccine
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• v.9 no.2
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• pp.201-207
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• 2002

Purpose : We analyzed clinical features and causal viruses of acute lower respiratory tract infections(LRTIs) in order to improve the management of these infections. Methods : From end of April to early May 2001, amongst 30 children at a local institute for children's adoption and welfare, 13 were admitted to the hospital with the diagnostic impression of acute LRTIs. Nasopharyngeal aspirates were sent in Seoul National University Hospital for viral culture of respiratory syncytial virus(RSV), adenovirus, parainfluenza virus. Results : One or more viral agents were identified in 4 cases(30.7%) : were RSV(15.4%), adenovirus(7.7%), and a mix of these two viruses(7.7%). Initial symptoms were fever(69%), cough(100%), tachypnea(54%), chest retraction(69%), rale(85%) and wheezing(15%). Leukocytosis was noted in 23%, CRP increased more than 10 mg/L in 46%. Chest X-ray abnormalities were 69%. Conclusion : Although viruses were identified in 30.7%, further studies should be made for prevention and treatment of acute viral LRTIs.

• Research in Plant Disease
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• v.11 no.2
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• pp.193-197
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• 2005

The effect of pH on the survival of R. solanacearum and its transmission via roots of tomato in hydroponic culture were studied in laboratory and greenhouse. In laboratory experiment, R. solanacearum could not survive for 24h in nutrient solution with pH of $4{\cdot}0;or\;4{\cdot}5$, while 1, 14, 51 and $62\%$ of inoculum survived at pH $5{\cdot}0,\;5{\cdot}6\;and\;6{\cdot}5$, respectively. When tomato plants were inoculated with R. solanacearum through wounds on the stems, the bacteria moved downward from the inoculation site to the roots and infectious bacteria were released from the roots into the nutrient solution. Of two pH regimes tested in greenhouse nutrient-film technique(NFT) culture, the R. solanacearum population was significantly lower in pH 5.0 than in pH 6.5 in most sampling data. In treatments in which R. solanacearum was introduced by transplanting two root-inoculated plants, significantly move plants developed wilt at pH $6{\cdot}5$(34 out of 48 plants) than at pH 5.0(11 out of 48 plants). In addition, when the bacterium was introduced by transplanting two stem-inoculated plants at pH $6{\cdot}5$, seven out of 24 plants developed wilt.

• Research in Plant Disease
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• v.15 no.2
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• pp.57-62
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• 2009

Genetic diagnosis method of Virion Captured (VC)/RT-PCR for Rice stripe virus (RSV) and Rice black-streaked dwarf virus (RBSDV), Korean major rice viruses transmitted by small brown plant hopper, Laodelphax striatellus, was developed. Virion extraction buffer for rice plant was 0.01M potassium phosphate buffer, pH 7.0, containing 0.5% sodium sulfite. However, the extraction buffer for L. striatellus was 0.01M potassium phosphate buffer, pH 7.0, containing 0.5% sodium sulfite and 2% polyvinylpyrrolidone wt 40,000 (PVP-40). Specific primers for detection of RSV and RBSDV were selected for VC/RT-PCR method. The specific primers were used as a duplex primer to detect viruliferous small brown plant hopper collected from Gimpo, Pyeongtaek and Siheung areas in Gyeonggi province. The genetic diagnosis methods of single and duplex VC/RT-PCR for RSV and RBSDV could be used easily and economically, especially on the diagnosis of L. striatellus. The rate of viruliferous insect (RVI) for RSV was compared with ELISA and VC/RT-PCR for L. striatellus collected from fields. RVI by ELISA was same as 9.2% with RVI by VC/RT-PCR. However, there were some different detection results between the methods. It could be suggested that there is a possibility of serological and/or genomic differences among RSV isolates. The portion of RVI detected simultaneously by ELISA and VC/RT-PCR was 71.0%, and the detection rate from VC/RT-PCR was higher as 3.2% than that from ELISA, which had a reason of simultaneous detection ability both RSV and RBSDV of VC/RT-PCR.

• Research in Plant Disease
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• v.15 no.2
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• pp.68-71
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• 2009

Cucumber green mottle mosaic virus (CGMMV) was not infected in figleaf gourd by sap inoculation. However CGMMV was detected by RT-PCR from the figleaf gourd collected from a field growing cucumber grafted onto figleaf gourd in Cheonan, Chungcheongnam Province in 2008. Which field showed 100% infection rate of the virus disease. In the experiment grafted with cucumber onto figleaf gourd, transportation of CGMMV through cucumber to figleaf gourd was confirmed by RT-PCR when the virus was mechanically inoculated on the leaves of the cucumber. The amplified DNA concentration of the virus on electrophoresis gel was much higher in the cucumber than in the figleaf gourd. However, the virus particles from the figleaf gourds were not observed under electron microscopy, also sap of the figleaf gourds was not transmittable to Nicotiana benthamiana. To identify the existence of CGMMV particle, the virus was purified from figleaf gourd and cucumber growing together in the graft system. CGMMV solution extracted from the cucumber represented a typical absorption spectrum of the virus but that from the figleaf gourd did not. Only a few CGMMV particles were observed in the purified preparation from the figleaf gourd. These results confirmed that CGMMV only passed through figleaf gourd in the grafting system. This study indicated that figleaf gourd is not a host of CGMMY.

• Research in Plant Disease
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• v.16 no.2
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• pp.129-135
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• 2010

PCR primers were developed to detect Pseudomonas savastanoi pv. phaseolicola, a causal agent of halo blight that occurs in all species of common bean (Phaseolus vulgaris L.), from the bean seeds. A primer set, Psp-JHF and Psp-JH-R, specifically amplified 513 bp fragment from Pseudomonas savastanoi pv. phaseolicola only. A nested primer set, psp-JH-F-ne and psp-JH-R-ne, designed from the $1^{st}$ PCR amplicon, amplified 169 bp fragment. The primer sets did not amplify any non-specific DNA from the seed extracts of Fabaceae including 4 beans, 2 soybeans, and 2 peas. The detection sensitivity of the nested PCR method developed in this study was much higher than that of ELISA and selective medium. PCR assays developed in this study should be useful to detect Pseudomonas savastanoi pv. phasolicola from the bean seeds.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.527-547
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• 2020

Fish pathogens cause not only economic damages to fish farming but also infectious pathogens known as a zoonotic agent. Since the continued use of antibiotics to control fish pathogens entails side effects, materials of natural origin need to be developed. The purpose of this study is to discover coniferous essential oils with excellent antibacterial effects in order to develop antibiotic alternatives. We have extracted essential oils using hydro-distillation from the leaves of Abies holophylla, Pinus thunbergii, Pinus parviflora, Tsuga sieboldii, and Pinus rigitaeda, which are all Pinaceae family. And, we have evaluated antibacterial activity with the extracted essential oils against Edwardsiella tarda, Photobacterium damselae, Streptococcus parauberis, and Lactococcus garvieae, which are fish pathogens. As a result, the essential oils from A. holophylla and P. thunbergii showed the selectively strong antibacterial activity against E. tarda and P. damselae, which are gram-negative bacteria. From GC-MS analysis, it was identified that main component of A. holophylla essential oils are (-)-bornyl acetate (29.45%), D-limonene (20.47%), and camphene (11.73%), and that of P. thunbergii essential oils is α-pinene (59.81%). In addition, we found three compounds: neryl acetate, (-)-borneol, and (-)-carveol, which are oxygenated monoterpenes. These exist in a very small amount but exhibit the same efficacy as essential oil. Therefore, we expect that A. holophylla and P. thunbergii essential oils having excellent growth inhibitory effect against gram-negative fish pathogens can be used as biological products such as feed additives and fishery products.

• Korean Journal of Medicinal Crop Science
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• v.6 no.4
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• pp.277-285
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• 1998

Antifungal activity on major seedborne diasease of crops was screened by the treatment of the extracts from 50 medicinal plants in vitro and in vivo. The extracts of garlic and taxus, Rheum undulatum, Achiranthes japonica, Glycyrrhiza uralensis, Oenothera lamar kiana treated with the blotting filter paper and water agar methods inhibited the growth of Pyricularia oryzae, Alternaria sesamicola, Colletotrichum gloeosporioides, and Alternaria brassicicola among the tested plants. Antifungal activities on infected seeds by soaking methods were shown even at the dilution of the extracts by 10 times. The activity was the highest in soaking seeds at $25^{\circ}C$ for 24 hours. The effect of plant extract on seed germination was not significant as compared with untreated seed. However, early growth of seedling was increased by the treatment of extracts. The extract of taxus slightly inhibited the seed germination of radish and chinese cabbage but those of Achirunthes japonica, Glycyrrhiza uralensis and Oenthfera lamarkiana showed severe damage on the seed germination and early growth of seedling.

• Journal of fish pathology
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• v.28 no.1
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• pp.27-35
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• 2015

VHSV is a major viral agent that affects freshwater and marine fish, causing serious economic losses in aquaculture in the world. Due to their filter-feeding activity, bivalve mollusks may act as viral transmitters after accumulation of the fish viruses released into seawater from infected fish. Amplification by RT-PCR was carried out to investigate the presence of VHSV in pacific oysters (Crassotrea gigas) and blue mussels (Mytilus edulis), inhabiting regions around aquatic farms in Korea. Primers designed from conserved regions of VHSVs allowed us to detect four different types of VHSV in a single PCR. Twenty two of the eighty four samples showed positive results of VHSV in a 2-step RT-PCR. Using six positive samples from three different regions in Korea, we cloned and sequenced the glycoprotein (G) gene (467-bp long) of VHSVs. Genetic analysis of the VHSVs detected in shellfish in various geographical areas of Korea showed highly restricted results to VHSV type Iva. This was in agreement with the reports showing only a single genotype of VHSV (Iva genotype) in outbreaks in cultured or wild fish in Korea. Consequently, we investigated VHSVs carried by bivalve mollusks inhabiting the vicinity of aquatic farms, and revealed correlationship between the type of viral accumulated in shellfish by filter-feeding, and those detected in disease outbreaks in fish.

• Journal of Life Science
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• v.27 no.5
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• pp.561-566
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• 2017

Dendropanax morbifera Lev. is known in Korea for its golden sap and medicinal properties. The many biological activities of the leaf and stem extracts suggest that this tree could be a valuable source of medicinal compounds for the treatment of various ailments such as dermatitis, migraines, dysmenorrhea, muscle pain, and infectious diseases. However, there is little information on the composition and biological activity of the volatile fraction of D. morbifera. Therefore, in this study, the volatile compounds in leaves, stems, and sap of D. morbifera were isolated using solvent and supercritical fluid extraction (SFE), and analyzed by gas chromatography/mass spectrometry to reveal their chemical composition and identify potential compounds of interest. Fifteen compounds were identified in the leaf extracts, whereas 29 and 3 compounds were identified in the stem and sap extracts, respectively. The volatile profiles obtained using solvent and SFE differed. Esters and aromatic hydrocarbons predominated in the solvent extract of leaves and SFE extract of stems, whereas the solvent extract of stems and SFE extract of leaves contained terpenoids. Limonene, ${\alpha}$-pinene, and ${\beta}$-myrcene were identified in the volatile extract of sap, with limonene representing 96.30% of the total peak area. In addition, the antiproliferative effects of the solvent extracts of leaves and stems were evaluated, revealing that these solvent extracts were particularly effective in decreasing the proliferation of HepG2 cells.