• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1519-1527
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• 2002

Purpose : Although influenza virus is one of the most important causes of acute respiratory tract infections(ARTIs) in children, virus isolation is not popular and there are only a few clinical studies on influenza in Korea. We evaluated the epidemiologic and clinical features of ARTIs by influenza virus in children. Methods : From February 1995 to August 2001, nasopharyngeal aspirations were obtained and cultured for the isolation of influenza virus in children admitted with ARTIs. The medical records of patients with influenza virus infection were reviewed retrospectively. Results : Respiratory viruses were isolated in 997(22.0%) out of 4,533 patients examined, and influenza virus was isolated in 164 cases(3.6%). Influenza virus was isolated year after year mainly from December to April of next year. The ratio of male and female was 1.9 : 1 with a median age of 15 months. The most common clinical diagnosis of influenza virus infection was pneumonia, and fever and cough developed in most patients. There was no difference between influenza A and B infection in clinical diagnoses and symptoms. All patients recovered without receiving antiviral treatment except for one patient diagnosed with pneumonia who had underlying disease of Down syndrome with ventricular septal defect. Conclusion : ARTIs caused by influenza virus developed every winter and spring during the period of study. Because fatal complication can develop in the high risk group, prevention, early diagnosis and proper management of influenza should be emphasized.

• The Plant Pathology Journal
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• v.24 no.2
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• pp.152-158
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• 2008

A peculiar virus-like disease of tomato showing yellow mosaic and necrotic spots on leaves and necrosis on veins, petioles and stems was observed at the Tomato Experimental Station (TES), Buyeo, Chungcheongnamdo, Korea. The disease incidence at TES fields ranged from 21 to 35% infecting different tomato cultivars. For this reason, to identify the virus infecting tomato and to characterize the virus based on biology, serology, cytology and at molecular level. Here, leaf samples were randomly collected from different infected tomato cultivars at TES fields and greenhouses and tested by ELISA using Pepper mottle virus (PePMoV) and Tomato mosaic virus (ToMV) antisera. Infected saps were mechanically inoculated in different host plants to test for pathogenicity, symptomatology and host ranges. Infected tissues and ultrathin sections were examined by electron microscopy. Finally, putative coat protein and 3'-untranslated region (CP/3'-UTR) fragment was amplified and cloned for sequence determination and analyzed its genetic relationship to existing PepMoV and PVY sequences at the Genbank. Results showed 69% of the samples were positive with PepMoV, 13% with ToMV and 19 % were doubly infected with PepMoV and ToMV. Symptoms greatly varied from different host plants inoculated with tomato leaf sap infected with PepMoV alone and discussed in detailed in this paper. Electron microscopy from infected tissues showed filamentous particles of 720-750nm in length, a typical morphology and size of PepMoV. In addition, cylindrical inclusion bodies, pinwheels, scrolls and laminates with masses of fibrillar inclusions were also found in ultrathin sections. Alignment of the sequences of the CP/3'-UTR revealed >96% sequence identity with PepMoV and only <61% with PVY. Taken together, all these evidences presented clearly indicated that the causal agent infecting tomato at TES was PepMoV and we designated this PepMoV infecting tomato as Tom-sd2 strain in this study.

• BMB Reports
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• v.45 no.3
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• pp.165-170
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• 2012

We report here that an ethanol extract of Tetracera scandens, a Vietnamese medicinal plant, has anti-HIV activity and possesses strong inhibitory activity against HIV-1 reverse transcriptase (RTase). Using a MT-4 cell-based assay, we found that the T. scandens extract inhibited effectively HIV virus replication with an $IC_{50}$ value in the range of 2.0-2.5 ${\mu}g$/ml while the cellular toxicity value (CC50) was more than 40-50 ${\mu}g$/ml concentration, thus yielding a minimum specificity index of 20-fold. Moreover, the anti-HIV efficacy of the T. scandens extract was determined to be due, in part, to its potent inhibitory activity against HIV-1 RTase activity in vitro. The inhibitory activity against the RTase was further confirmed by probing viral cDNA production, an intermediate of viral reverse transcription, in virus-infected cells using quantitative DNA-PCR analysis. Thus, these results suggest that T. scandens can be a useful source for the isolation and development of new anti-HIV-1 inhibitor(s).

• Journal of fish pathology
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• v.6 no.2
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• pp.87-92
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• 1993

In February of 1990, an epizootic disease to masu salmon. Onchorynchus masou cultured at the hatchery of trout in Samchuk. Kwangwondo have broken out and induced heavy mortality. An infectious hematopoietic necrosis virus(IHNV) was isolated from diseased masu salmon fry by the use of fish cell line, CHSE-214. This IHNV isolated from masu salmon was compared with USA isolates of IHNV, SRCV and RB-76 by analysis of virion proteins in sodium dodecyl sulfate poly-acrylamide gel electrophoresis (SDS-PAGE) and neutralization tests with two monoclonal antibodies raised against SRCV(MAb SRCV/A4) and RB-76(MAb RB/B5). In the antigenicity and the size of structural proteins. this IHNV, SCS atrain was smilar to RB-76 belonged to the electropherotype I proposed by Hsu et al.(1986).

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.735-741
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• 1995

The present study was conducted to investigate the incidence of equine herpesvirus 1(EHV-1) infection in Korean horses by cell EUSA and serum neutralization test A significant level of antibodies to EHV-1 was detected from 539(82.8%) by cell EUSA and from 524 horses(80.5%) by SNT indicating that EHV-1 infection in Korean horses are widely spreaded throughout the country.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.753-758
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• 1995

The study was carried out to investigate the pathogenicity of EHV isolate to hamsters and mice and immunogenicity of experimentally produced. vaccine were evaluated in the horses. Hamsters infected. intranasally with $LC_1$ isolate showed symptoms of nasal discharge, conjunctivitis and body weight loss during the observation period of 12 days after infection, while only slight depression and body weight loss were noticed with mice infected with $LC_1$ indicating that hamsters are more susceptible to the virus. Antibody titer of mice and hamsters were gradually increased to highest level of 1:2560~10240, 1:640~1280, respectively, at 7~12 days post vaccination. Horses immunized against $LC_1$ killed vaccine reached to maximum antibody titer of 1:20480 around 4 weeks after 1st vaccination and declined after 12 weeks post vaccination. No significant antibody increase were detected after 2nd vaccination. Mean body temperature and mean total leukocyte counts remained within normal range and no adverse reaction were noticed after vaccination.

• Journal of fish pathology
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• v.19 no.1
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• pp.55-64
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• 2006

Rhabdovirus-like virus were isolated from the fry (15~30 days post hatching, dph) and rearing water of the snakehead fish Channa arga exhibiting mass mortality in spring of 2003 and 2004 in Korea. The isolates were propagated in EPC and SSN-1 cells but not replicated in FHM cells. The bullet-shaped viral particles (45×100 nm) appeared to be compact and a similar morphology to those of the rhabdoviruses in the infected EPC cells. The optimum temperature for virus replication was 20 to 25℃ but they could not replicate at 15℃. The isolates ShFRV-3 and ShFRV-5 from snakehead fish showed high pathogenicity against the fry (15 dph) and fingering (40 dph) of snakehead fish but did not in the larger size (90 dph).

• Journal of fish pathology
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• v.16 no.1
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• pp.1-12
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• 2003

RT-PCR method was applied to detect and clone the nucleocapsid protein (N) gene and glycoprotein (G) gene for sequencing 5 Korean VHSV isolates from cultured olive flounder, Paralichthys olivaceus. Phylogenetic analysis was performed to investigate their relationship with the VHSV strains described previously and isolated from different geographical area. Generally, VHSV strains were separated phylogenetically according to the major geographical area of isolation: Genogroup I (American type), Genogroup Il (British Isles) and Genogroup ill (European type). This study revealed that all 5 Korean VHSV isolates were belonged to Genogroup I and closely related to Japanese Obama25 type.

• Journal of fish pathology
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• v.8 no.2
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• pp.91-98
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• 1995

During 1993 and 1994, some mortalities of flounder(Paralichthy olivaceus) fry were recorded in several fish farms and viruses were isolated from 3 of the farms. Electron microscopic examination revealed that the virus particles were hexagonal and unenveloped with an average diameter of 50 to 55nm. Serological and molecular properties of these isolates were examined. The viral RNA and polypeptides patterns on electrophoresis, as well as neutralization test results, showed that these isolates were birnaviruses and two were closely related to infectious pancreatic necrosis virus(IPNV) serotype AB and one was to IPNV serotype SP. This is the first isolation of birnaviruses from marine fish in Korea.

• Journal of fish pathology
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• v.16 no.2
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• pp.81-90
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• 2003

High mortality with signs similar to viral haemorrhagic septicemia (VHS) such as severe haemorrhages in the skin, muscle and air bladder occurred in the farmed adult rainbow trout, Oncorhynchus mykiss, in Ku-mi and Je-chun area in Korea. The isolates were neutralized by an antiserum against IHNV but not by antisera against VHSV. Electron micrograph of an ultrathin section showed large numbers of bullet-shaped virus particles. The newly isolated rhabdovirus was composed of five structural proteins. In the western blot analysis Ihe anti-DiNV serum strongly reacted with G. N and MI protein. The cumulative mortalities of RTK infected rainbow trout (10-12cm.9-12g) with $10^{3.5}\;and\;10^{1.5}TCID_{50}/m{\ell}$ were 80% and 30%. respectiveIy_ RTJ infected fish showed 50% mortality by infection with $10^{3.5}TCID_{50}/m{\ell}$. Control group and IHNVChAb exhibited no mortality. From these results, the viruses were identified lHNV although diseased fish showed similar sign. with VHS and caused high mortality in large-sized fish.