• Journal of fish pathology
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• v.12 no.1
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• pp.56-62
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• 1999

Since 1998, mass mortality of the Japanese flounder has widely occurred in the south and west coastal area of Korea. A new serotype birnavirus was isolated during the investigation of the cause of the disease. By the electromicroscopic examination, the isolated virus particles appeared hexagonal and unenveloped with an average diameter 52 to 56 nm. Birnavirus specific fragment was amplified by RT-PCR. High yield of virus (10.3 to 10.8 log $TCID_{50}/ml$) was produced in CHSE-214. RTG-2 and RTE-2 cells. Typical birnavirus CPE was observed in these cells. On the contrary, the virus CPE was not shown in the FHM and EPC cells. By a cross-neutralization test with IPNV Ab, IPNV Sp, IPNV VR-299 and MBV Y6, the isolated virus was closely related to marine birnavirus (MBV).

• Korean Journal of Veterinary Service
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• v.45 no.1
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• pp.31-38
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• 2022

Swine influenza (SI) is an important respiratory disease in pigs and epidemic worldwide, which is caused by influenza A virus (IAV) belonging to the family of Orthomyxoviridae. As seen again in the 2009 swine-origin influenza A H1N1 pandemic, pigs are known to be susceptible to swine, avian, and human IAVs, and can serve as a 'mixing vessel' for the generation of novel IAV variants. To this end, the emergence of swine influenza viruses must be kept under close surveillance. Herein, we report the isolation and phylogenetic study of a swine IAV, A/swine/Korea/21810/2021 (sw21810, H3N2 subtype). BLASTN sequence analysis of 8 gene segments of the isolated virus revealed a high degree of nucleotide similarity (94.76 to 100%) to porcine strains circulating in Korea and the United States. Out of 8 genome segments, the HA gene was closely related to that of isolates from cluster I. Additionally, the NA gene of the isolate belonged to a Korean Swine H1N1 origin, and the PB2, PB1, NP and NS genes of the isolate were grouped into that of the Triple reassortant swine H3N2 origin virus. The PA and M genes of the isolate belonged to 2009 Pandemic H1N1 lineage. Human infection with mutants was most common through contact with infected pigs. Our results suggest the need for periodic close monitoring of this novel swine H3N2 influenza virus from a public health perspective.

• Journal of Microbiology and Biotechnology
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• v.21 no.10
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• pp.1043-1048
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• 2011

A methanol extract of Cassia tora seeds was successively partitioned with diethyl ether, chloroform, ethyl acetate, and water, and the antitumor-promoting activity of the solvent fractions was determined by inhibition of Epstein-Barr virus early antigen (EBV-EA) activation induced by teleocidin B-4 in Raji cells. The diethyl ether (68.7%) and chloroform (91.2%) fractions and the hydrolysate (94.3%) of the ethyl acetate fraction had strong inhibitory activities. The chloroform and ethyl acetate fractions were chromatographed on silica gel and further purified by HPLC. Three active compounds, obtusifolin-2-glucoside (75.0%), chryso-obtusin-6-glucoside (56.8%), and norrubrofusarin-6-glucoside (39.4%), were obtained from the ethyl acetate fraction, and two active compounds, questin (97.9%) and chryso-obtusin (53.8%), were isolated from the chloroform fraction.

• Safety and Health at Work
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• v.2 no.1
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• pp.83-86
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• 2011

New epidemics of infectious diseases often involve health care workers. In this short communication we present a case report of a health care professional who became the first case of influenza H1N1 virus to be notified in the United Arab Emirates. There are several issues related to workplace considerations and general public health, including preventive measures, the need for isolation of the patient, dealing with contacts, return to work, and communication with the workforce.

• KSBB Journal
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• v.13 no.6
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• pp.656-661
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• 1998

Hantaan virus belonging to the genus Hantavirus and family Bunyaviridae causes an acute severe illness of human, Haemorrhagic Fever with Renal Syndrome (HFRS). It is a rodent host-borne pathogen and distributed in Asia and Eastern Europe. Hantaviruses have three major antigens, i.e., G1, G2 glycoproteins and nucleocapsid protein (N). Among them, nucleocapsid protein was reported to be the most invaluable antigen as for diagnosis. We have cloned and expressed Hantaan viral nucleocapsid gene in E. coli BL21(DE3). In this study, we have tried to purify the nucleocapsid protein produced by recombinant E. coli, and could attained a purity of >90% by anti-N monoclonal antibody-coupled immunoaffinity chromatography or phenyl sepharose hydrophobic interaction chromatography.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.177-183
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• 1997

One cytopathogenic virus was isolated in alveolar macrophages from pig without any apparent respiratory clinical signs. Biophysical properties and electron microscopy of the isolate showed the characteristics of adenovirus. Intracytoplasmic inclusion bodies were seen in virus-inoculated cells. The genetic analysis indicated the presence of DNA with the size of >20Kb. In a serological survey of 40 serum samples collected from two different farms in slaughter house, 9 sera were positive for neutralizing antibody against the isolate. The potential implications of the isolate as the causative agent in respiratory disorder were discussed.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.1-5
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• 2022

Diagnostics, vaccines, and drugs are indispensable tools and control measures employed to overcome infectious diseases such as coronavirus disease 2019 (COVID-19). Diagnostic tools based on RT-PCR were developed early in the COVID-19 pandemic and were urgently required for quarantine (testing, tracing and isolation). Vaccines such as mRNA vaccines and virus-vectored vaccines were also successfully developed using new platform technologies within one year after identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the causative agent of COVID-19. Drug development has been conducted in various ways including drug repurposing, convalescent plasma therapy, and monoclonal antibody development. Among the above efforts, this review examines COVID-19 drug development along with the related and upcoming challenges.

• Korean Journal of Veterinary Research
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• v.49 no.3
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• pp.207-213
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• 2009

Rabbit hemorrhagic disease (RHD) is caused by RHD virus (RHDV) and is one of the most fatal diseases of rabbits. Acute death of rabbits occurred in a farm located in the Gyeonggi province of South Korea. The virus was isolated and confirmed as RHDV based on reverse transcription polymerase chain reaction and hemagglutination assay (HA), and the isolate was designated as KV0801. The nucleotide sequence of the complete VP60 gene of KV0801 was determined and the corresponding amino acid sequence was deduced. Molecular analysis showed that the KV0801 isolate can be classified as a pandemic antigenic variant strain, RHDVa. The VP60 nucleotide sequence and deduced amino acid homology between KV0801 and other Korean isolate, RHF89, which was isolated in 1988, were 92.1 and 94.3%, respectively. The pathogenicity of the KV0801 isolate at an HA titer ranging from 16,384 to 0.16 HA units was evaluated in five-month-old SFP rabbits. The rabbits inoculated with KV0801 isolate containing more than 1.63 HA units died within six days of inoculation. These results suggest that a highly pathogenic RHDVa is circulating in the rabbit populations of Korea.

• Korean Journal of Veterinary Research
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• v.48 no.1
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• pp.61-66
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• 2008

Akabane disease is caused by an arthropod-borne viral pathogen and leads to congenital abnormalities of the central nervous system in infected ruminants. One isolate, KV0505, showed cytopathic effect in Vero cells. The KV0505 isolate was obtained from plasma, which was collected from a cattle raised on Jeju Island in May 2005. Jeju Island is located near the southern part of the Korean peninsula. The isolate was confirmed as Akabane virus (AKAV) by immunofluorescence assay using AKAV specific monoclonal antibodies and reverse transcription polymerase chain reaction (RTPCR). Suckling mice inoculated with the isolate showed signs of paralysis and died within 10 days postinoculation. Comparisons of the KV0505 N gene sequence with 39 other known AKAV strains revealed nucleotide homologies ranging from 83.6% (MP496 strain) to 99.7% (M171 strain). When compared with the K-9 strain, which was isolated from a cow in Korea in 1994, the nucleotide sequence homology with the N gene was 99.7%. Thus, genes of the KV0505 isolate were closely related to those of the M171 strain, which were clustered into the Ic group of AKAV.

• Korean Journal of Pharmacognosy
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• v.29 no.4
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• pp.277-282
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• 1998

In order to search for anti-Herpes simplex virus type 1(HSV-1) agents, we screened 80 specimens of Korean traditional medicine by SRB assay. The methanol extracts of Thujae orientalis Semen (Cupressaceae) showed strong anti-HSV activity among samples tested. From the butanol fraction of Thujae orientalis Semen anti-HSV-1 agent was isolated by chromatographic separation using Amberlite XAD-4 and Sephadex LH-20. The structure was elucidated by spectroscopic methods, and was identified as ${\beta}-sitosterol$ (compound I). Compound I exhibited anti-HSV-1 activity with $EC_{50}$ of 0.6 mg/ml and $CC_{50}$ of 5.99 mg/ml, respectively.