• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2000년도 추계학술발표대회
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• pp.66-77
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• 2000

For a variety of viruses, the primary virus infection has been shown to prevent superinfection with a homologous secondary virus; however, the mechanism of exclusion has not been clearly understood. In this work, we demonstrated that BVDV -infected MDBK cells were protected from superinfection with a homologous superinfecting BVDV, one of the positive-sense RNA pestiviruses, but not with an unrelated rhabdovirus, such as vesicular stomatitis virus. Once superinfection exclusion was established by a primary infection with BVDV, the transfected infectious BVD viral RNA genome was shown to be competent for viral translation, but not viral replication. In addition, our results also demonstrated that upon superinfection, the. viral RNA genome of viral particles was not transferred into the cytoplasm of BVDV -infected cells. Using newly developed system involving rapid generation of the MDBK cells expressing BVD viral proteins, we subsequently found that expression of the viral structural proteins was dispensable for the block occurring at the level of viral RNA replication, but required for the exclusion at the level of viral entry step. Altogether, these findings provide evidence that the superinfection exclusion of BVDV occurs not only at the level of viral replication in which the viral replicase are involved, but also at the level of viral entry with which the viral structural proteins are associated, and that a cellular factor(s) play an essential role in this process.

• 한국컴퓨터정보학회논문지
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• 제25권7호
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• pp.65-73
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• 2020

바이럴 영상광고는 광고 및 영화산업에서 특정제품이나 개봉전 영화에 대한 사전 홍보 목적으로 활용되고 있으며, 투자 대비 많은 효과를 내고 있다. 향후 발전 방향을 예측해 보려면 바이럴 영상 인식에 대한 분석이 필요하다. 이에 본 연구는 광고나 영화를 가장 많이 접하는 연령층인 20대 대학생 118명에 대한 바이럴 영상 설문조사를 하였다. 이를 통해 바이럴 영상에 대한 인지 여부, 기억에 남는 바이럴 영상, 만족도, 메시지 전파여부, 전파 방식, 바이럴 영상에 대한 긍정도, 향후 발전 예상, 희망하는 바이럴 영상 유형 등에 대한 설문을 실시하였다. 이 결과 바이럴 영상 인지도는 16.7%로 나타났고, 가장 기억에 남는 바이럴 영상으로 "겨울왕국" 영화의 "Let it Go" 영상이 설문조사 결과 69.1%로 나타났다. 바이럴 영상에 대한 만족도는 31.2%로 높지 않았으며, 바이럴영상을 시청한 후 타인에게 메시지를 전달한 경우는 73.5%로 높게 나타났다. 바이럴 영상에 대한 부정적 의견은 13.7%로 낮게 나타났으며, 바이럴 영상 분야가 64.5%는 "발전할 것이다"라고 답하였고, 6.7%는 "발전하지 못할 것이다"라고 답하였다.

• Clinical and Experimental Pediatrics
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• 제64권12호
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• pp.652-660
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• 2021

Background: Viral load and shedding duration are highly associated with the transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, limited studies have reported on viral load or shedding in children and adolescents infected with sudden acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Purpose: This study aimed to investigate the natural course of viral load in asymptomatic or mild pediatric cases. Methods: Thirty-one children (<18 years) with confirmed SARS-CoV-2 infection were hospitalized and enrolled in this study. Viral loads were evaluated in nasopharyngeal swab samples using real-time reverse transcription polymerase chain reaction (E, RdRp, N genes). cycle threshold (Ct) values were measured when patients met the clinical criteria to be released from quarantine. Results: The mean age of the patients was 9.8 years, 18 (58%) had mild disease, and 13 (42%) were asymptomatic. Most children were infected by adult family members, most commonly by their mothers. The most common symptoms were fever and sputum (26%), followed by cough and runny nose. Nine patients (29%) had a high or intermediate viral load (Ct value≤30) when they had no clinical symptoms. Viral load showed no difference between symptomatic and asymptomatic patients. Viral rebounds were found in 15 cases (48%), which contributed to prolonged viral detection. The mean duration of viral detection was 25.6 days. Viral loads were significantly lower in patients with viral rebounds than in those with no rebound (E, P=0.003; RdRp, P=0.01; N, P=0.02). Conclusion: Our study showed that many pediatric patients with coronavirus disease 2019 (COVID-19) experienced viral rebound and showed viral detection for more than 3 weeks. Further studies are needed to investigate the relationship between viral rebound and infectiousness in COVID-19.

• Journal of Pharmaceutical Investigation
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• 제34권5호
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• pp.351-362
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• 2004

The basic concept underlying gene therapy is that human diseases may be treated by the transfer of genetics material into specific cells of a patient in order to correct or supplement defective genes responsible for disease development. There are several systems that can be used to transfer foreign genetic material into the human body. Both viral and non-viral vectors are developed and evaluated for delivering therapeutic genes. Viral vectors are biological systems derived from naturally evolved viruses capable of transferring their genetics materials into host cells. However, the limitations associated with viral vectors, in terms of their safety, particularly immunogenecity, and their limited capacity of transgenic materials, have encouraged researchers to increasingly focus on non-viral vectors as an alternative to viral vectors. Although non-viral vectors are less efficient than viral ones, they have the advantages of safety, simplicity of preparation and high gene encapsulation capability. This article reviews the most recent studies highlighting the advantages and the limitation of gene delivery systems focused on non-viral systems compared to viral systems.

• Genomics & Informatics
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• 제11권3호
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• pp.121-128
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• 2013

The introduction of metagenomics into the field of virology has facilitated the exploration of viral communities in various natural habitats. Understanding the viral ecology of a variety of sample types throughout the biosphere is important per se, but it also has potential applications in clinical and diagnostic virology. However, the procedures used by viral metagenomics may produce technical errors, such as amplification bias, while public viral databases are very limited, which may hamper the determination of the viral diversity in samples. This review considers the current state of viral metagenomics, based on examples from Korean viral metagenomic studies-i.e., rice paddy soil, fermented foods, human gut, seawater, and the near-surface atmosphere. Viral metagenomics has become widespread due to various methodological developments, and much attention has been focused on studies that consider the intrinsic role of viruses that interact with their hosts.

• Biomolecules & Therapeutics
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• 제29권3호
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• pp.268-272
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• 2021

Novel coronavirus (SARS-CoV-2) has caused more than 100 million confirmed cases of human infectious disease (COVID-19) since December 2019 to paralyze our global community. However, only limited access has been allowed to COVID-19 vaccines and antiviral treatment options. Here, we report the efficacy of the anticancer drug pralatrexate against SARS-CoV-2. In Vero and human lung epithelial Calu-3 cells, pralatrexate reduced viral RNA copies of SARS-CoV-2 without detectable cytotoxicity, and viral replication was successfully inhibited in a dose-dependent manner. In a time-to-addition assay, pralatrexate treatment at almost half a day after infection also exhibited inhibitory effects on the replication of SARS-CoV-2 in Calu-3 cells. Taken together, these results suggest the potential of pralatrexate as a drug repurposing COVID-19 remedy.

• 대한수의학회지
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• 제29권4호
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• pp.531-540
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• 1989

A new sudden death in rabbits appeared in China and Korea in 1984 and 1985, respectively, and was recognized to be an acute infectious disease caused by a virus. The disease was reported as a "new viral disease," and thereafter, a tentative name of "viral hemorrhagic disease", "hemorrhagic pneumonia" or "viral hemorrhagic pneumonia" has been described in the case reports. But authors had called the viral disease "rabbit viral hepatitis" due to picornavirus infection, because the principal lesion of the disease was an acute hepatitis. The purpose of this report is to describe the electron microscopic findings on the livers in experimentally infected rabbits. All the livers of the affected rabbits were shown to have degenerative changes of a type that is characteristic of acute hepatitis. In the liver cells, there were dilation of rER and mitochondria, vacuole formation of various sizes, and appearances of many virus-like particles in the vicinity of rER, granular bodies and crystalline arrays of viral particles in the cytoplasm with necrotic changes of the nucleus. Clusters of virus-like particles and viral crystals appeared in the cytoplasm of sinusoid endothelial cells and Kupffer's cells with morphological changes of organelles. Also viral crystals were demonstrated in the cytoplasm of macrophages among the liver cells. On the whole, the liver cells had many virus-like particles and a few crystalline arrays of viral particles. Therefore, this implies that the liver cells are the main site of the viral replication in inducing the viremia. It was concluded that the liver was the primary target organ of this viral disease, and the pathological and the ultrastructural evidence suggest that the virus may be belong to genus enterovirus.

• 미생물학회지
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• 제25권1호
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• pp.34-39
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• 1987

활발히 생장하고 있는 돼지 태아 선상세포에서. 정상적인 human 세포 배양으로부터 분리된 single-stranded DNA parvovirus KBSH 의 초기 증식 특성을 알아보기 위해, 합성되는 virus의 hemagglutinating(HA) antigen 양과 virus의 d double-stranded replicative form(RF) DNA 합성 속도를 조사하였다virus의 RFDNA 합성이 시작되는 감염 후 15-16 시간 때와 거의 동시에 virus에 감엽된 숙주셔1포의 DNA 합성 속도가 감소하기 시작하였으며, virus의 RF DNA 합성속도 가 최대에 년한 후 간소하시 시작하는 감염 후 24시간 때부터 virus의 HA antigen이 배지상으로 방출되기 시작하였다. 그러고 virus의 RF DNA 복체에는 virus에 감염된 세포에서 감염 후 10-14시간 때에 형성되는 만액섣들이 관여함을 말았다.

• 한국IT서비스학회지
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• 제13권3호
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• pp.257-274
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• 2014

Social Network Services (SNSs) have grown to be new and promising tools of marketing. By referring to researches done on e-mail viral marketing, this paper operationizes SNS viral marketing effectiveness to accurately reflect marketing success in SNS environment, and tries to identify its affecting factors. As potential affecting factors, fan size, advertisement type, existence of engagement elicitation and incentive are identified. By sampling real advertisement postings on Facebook, we showed that fan size, advertisement type, and engagement elicitation are factors affecting SNS viral marketing success. This research expanded the conventional model of viral marketing into SNS settings to improve understanding on SNS viral marketing. Motivation is discussed as an important factor, and this research showed that viral campaign can be more successful when it triggers internal motivation to engage, but not the external motivation. This research could also be a guide for practitioners on how to post a successful advertisement in SNSs.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1273-1281
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• 2020

Due to the broad host suitability of viral vectors and their high gene delivery capacity, many researchers are focusing on viral vector-mediated gene therapy. Among the retroviruses, foamy viruses have been considered potential gene therapy vectors because of their non-pathogenicity. To date, the prototype foamy virus is the only retrovirus that has a high-resolution structure of intasomes, nucleoprotein complexes formed by integrase, and viral DNA. The integration of viral DNA into the host chromosome is an essential step for viral vector development. This process is mediated by virally encoded integrase, which catalyzes unique chemical reactions. Additionally, recent studies on foamy virus integrase elucidated the catalytic functions of its three distinct domains and their effect on viral pathogenicity. This review focuses on recent advancements in biochemical, structural, and functional studies of foamy virus integrase for gene therapy vector research.