• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.584-587
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• 2018

Many viruses including mouse hepatitis virus, corona, measles, and sidbis viruses are known as causative virus of inducing demyelination which means destruction of myelination in nervous system of mice. The purpose of this study is to investigate processing of myelination by co-culture of Schwann cells and neuronal cells and demyelination induced by infection of sindbis virusin rat. Schwann cells and neuronal cells from dorsal root ganglion (DRG) in embryos (E16) of rat were cultured in vitro respectively. The purified neuronal cells with anti-mitotic agents and purified Schwann cells were co-cultured. After that, infection of sindbis virus into this myelinated co-culture system was performed. Myelination and demyelination process were observed using antibody of myelin basic protein meaning presence of myelination.We identified myelination and demyelination processing using antibody of peripheral myelin protein 22 (PMP 22) meaning presence of myelinated neuron. This study was supported by the Basic Research Program through the National Research Foundation (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2015R1C1A1A01053484 and 2017R1A2B3005753).

• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.285-291
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• 2005

The nonstructural protein 5B (NS5B) of hepatitis C virus (HCV) is the viral RNA-dependent RNA polymerase (RdRp), which is the essential catalytic enzyme for the viral replication and is an appealing target for the development of new therapeutic agents against HCV infection. A small amount of serum from a single patient with hepatitis C was used to get the genome of a Korean HCV isolate. Sequence analysis of NS5B 1701 nucleotides showed the genotype of a Korean isolate to be subtype 1b. The soluble recombinant HCV NS5B polymerase lacking the C-terminal 24 amino acids was expressed and purified to homogeneity. With the highly purified NS5B protein, we established in vitro systems for RdRp activity to identify potential polymerase inhibitors. The rhodanine family compounds were found to be potent and specific inhibitors of NS5B from high throughput screening (HTS) assay utilizing the scintillation proximity assay (SPA) system. The binding mode of an inhibitor was analyzed by measuring various kinetic parameters. Lineweaver-Burk plots of the inhibitor suggested it binds not to the active site of NS5B polymerase, but to an allosteric site of the enzyme. The activity of NS5B in in vitro polymerase reactions with homopolymeric RNA requires interaction with multiple substrates that include a template/primer and ribonucleotide triphosphate. Steady-state kinetic parameter, such as Km, was determined for the ribonucleotide triphosphate. One of compounds found interacts directly with the viral polymerase and inhibits RNA synthesis in a manner noncompetitively with respect to UTP. Furthermore, we also investigated the ability of the compound to inhibit NS5B-directed viral RNA replication using the Huh7 cell-based HCV replicon system. The investigation is potentially very useful for the utility of such compounds as anti-hepatitic agents.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1705-1712
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• 2016

Background: The aim of this study was to determine and evaluate the association of different viral infections, with hepatitis B and C viruses, Epstein-Barr virus, cytomegalovirus and human herpes virus-8 (HBV, HCV, EBV, CMV, HHV-8) with the risk of lymphomas (Hodgkin and non-Hodgkin) among Egyptian patients, and correlate with the histopathological staging and typing as well as the prevalence of combined infections. Materials and Methods: A total of 100 newly diagnosed lymphoma patients with 100 healthy age and sex matched normal controls were assayed for viral infection using enzyme linked immunosorbant assay (ELISA) followed by real time polymerase chain reaction (RT-PCR). Results: Our results showed a high statistical significant difference between cases and controls as regards clinical and laboratory findings (P<0.001 and=0.003). A high statistical difference was seen for the association of most viruses and lymphoma cases (p<0.001) except for positive HBs Ag, positive CMV IgG and HHV-8 (p=0.37, 0.70 and 1.0 respectively). No statistical significant difference was found between Hodgkin (HL) and non-Hodgkin (NHL) as regards viral prevalence except HCV antigen, 57.1% for HL and 26.5% for NHL (p = 0.03). Only, HBV DNA showed a high significant value among infiltrated bone marrow cases (p=0.003) and finally, a high significant association of 2 combined viral infections with infiltrated bone marrow lymphoma cases (p=0.04). Conclusions: Our results showed that infection with HBV, HCV, CMV and EBV were associated with increased risk of lymphoma among the Egyptian population. Detection of new associations between infectious agents and risk of cancer development will facilitate progress in elaboration of prophylactic measures, early diagnostic methods and, hopefully, novel therapy of malignant tumours.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.1
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• pp.28-37
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• 2022

Pregnancy requires an important interpretation of thyroid function tests. The presence of anti-thyroid antibodies and viral infectious agents affect the health of both the fetus and the mother. Hence, a selective evaluation of thyroid function in pregnancy is required. This study is a retrospective cross-sectional survey to examine the correlation between thyroid hormones and viral infections during pregnancy. The results showed that the triiodothyronine (T3) decreased with increasing age, especially in the hepatitis C virus (HCV)-positive group (P<0.01). In addition, although negative for the human immunodeficiency virus (HIV), thyroxine (FT4) showed a significant increase in near-threshold or twin pregnant women (P<0.05). The thyroid stimulating hormone (TSH) was highly distributed at the age of 30, and there was no statistically significant correlation with other viral infection factors. In addition, as a result of dividing and analyzing the result of TSH by the quantiles, FT4 and T3 showed a positive correlation but showed a negative correlation with TSH (P<0.05). Therefore, the evaluation of prenatal thyroid screening during pregnancy and viral infection factors should reflect the time of pregnancy, exposure to infection, and the quantitative values. Adequate thyroid hormone and viral infections availability is important for an uncomplicated pregnancy and optimal fetal development.

• BMB Reports
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• v.42 no.12
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• pp.834-839
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• 2009

DNA methyltransferase (DNMT) 1 is the key enzyme responsible for DNA methylation, which often occurs in CpG islands located near the regulatory regions of genes and affects transcription of specific genes. In this study, we examined the possible association of DNMT1 polymorphisms with HBV clearance and the risk of hepatocellular carcinoma (HCC). Seven common polymorphic sites were selected by considering their allele frequencies, haplotype-tagging status and LDs for genotyping in larger-scale subjects (n = 1,100). Statistical analysis demonstrated that two intron polymorphisms of DNMT1, +34542G > C and +38565G > T, showed significant association with HBV clearance in a co-dominant model (OR = 1.30, $P^{corr}$ = 0.03) and co- dominant/recessive model (OR = 1.34-1.74, $P^{corr}$ = 0.01-0.03), respectively. These results suggest that two intron polymorphisms of DNMT1, +34542G > C and +38565G > T, might affect HBV clearance.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7251-7256
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• 2013

Objectives: To estimate the proportion of liver cancer cases and deaths due to infection with hepatitis B virus (HBV), hepatitis C virus (HCV), aflatoxin exposure, alcohol drinking and smoking in China in 2005. Study design: Systemic assessment of the burden of five modifiable risk factors on the occurrence of liver cancer in China using the population attributable fraction. Methods: We estimated the population attributable fraction of liver cancer caused by five modifiable risk factors using the prevalence data around 1990 and data on relative risks from meta-analyses, and large-scale observational studies. Liver cancer mortality data were from the 3rd National Death Causes Survey, and data on liver cancer incidence were estimated from the mortality data from cancer registries in China and a mortality/incidence ratio calculated. Results: We estimated that HBV infection was responsible for 65.9% of liver cancer deaths in men and 58.4% in women, while HCV was responsible for 27.3% and 28.6% respectively. The fraction of liver cancer deaths attributable to aflatoxin was estimated to be 25.0% for both men and women. Alcohol drinking was responsible for 23.4% of liver cancer deaths in men and 2.2% in women. Smoking was responsible for 18.7% and 1.0%. Overall, 86% of liver cancer mortality and incidence (88% in men and 78% in women) was attributable to these five modifiable risk factors. Conclusions: HBV, HCV, aflatoxin, alcohol drinking and tobacco smoking were responsible for 86% of liver cancer mortality and incidence in China in 2005. Our findings provide useful data for developing guidelines for liver cancer prevention and control in China and other developing countries.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.293-298
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• 2008

HCV is transmitted via various plasma derived products. Current methods to detect hepatitis C virus (HCV) are based on its antibody detection in the donated blood and plasma. Viral contamination can potentially escape such detection during the window period of infection, when no antibody is present or the level of antibody is too low to detect. It is trying to application of nucleic acid amplification tests (NAT) for the direct detection of HCV. The objective of this study was to develop a reliable NAT for the HCV RNA detection from plasma-derived products. The most useful primers was selected for NAT among 5 sets of primers. We have also found that QIAamp viral RNA isolation kit was the most efficient for HCV RNA isolation. The highest sensitivity and specificity was appeared in $48^{\circ}C$ annealing temperature and 30 pmol of primers. With a spiking of HCV to albumin, immunoglobulins and coagulation factors, NAT can detect up to 100 IU/ml. Meanwhile, COBAS amplicor HCV 2.0 afforded a lower sensitivity in high concentrated intramuscular immunoglobulins to below 500 IU/ml. Our results suggested that NAT appears to be a highly sensitive and specific method for HCV RNA detection in plasma-derived products.

• Clinical and Experimental Pediatrics
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• v.51 no.11
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• pp.1191-1197
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• 2008

Purpose : Previously, Epstein-Barr virus (EBV) infection was diagnosed by serological examination; currently, many EBV antigen detection methods have been developed and applied clinically for diagnosing EBV infection. To delineate the clinical characteristics of EBV infection, clinical and laboratory findings were evaluated for patients who tested positive in EBV polymerase chain reaction (PCR). Methods : EBV PCR was conducted in 352 patients admitted to the pediatric ward from January 2004 to December 2006, with more than 2 clinical signs such as fever (${\geq}37.5^{\circ}C$), exudative throat infection, lymphadenopathy, hepatitis of unknown etiology, and splenomegaly. The EBV viral gene was detected by PCR in 115 patients (32%), and the clinical characteristics of these patients were evaluated. Laboratory findings such as leukocytosis, thrombocytopenia, atypical lymphocyte, and alteration in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in peripheral blood were examined. The EBV-specific immunoglobulin M antibody (EBV-IgM Ab) was also tested. Results : Most of the children were younger than 8 years (89%), and the male to female ratio was 1.3:1. Exudative throat infection and fever (${\geq}37.5^{\circ}C$) were observed in all patients. Cervical lymph node enlargement was seen in 36 patients (31 %); leukocytosis ($WBC{\geq}10,000/mm^3$), in 54 patients (47%); and atypical lymphocyte (${\geq}20%$), in 28 patients (24%). EBV-IgM Ab was positive in 33 patients (29%). The younger patients had higher ALT levels and higher incidence of positive EBV-IgM Ab than the older patients. Conclusion : The cumulative number of patients diagnosed to have EBV infection by PCR increased markedly for those under 8 years. ALT was higher and EBV-IgM Ab was detected more in younger patients with EBV infection.

• Pediatric Infection and Vaccine
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• v.12 no.2
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• pp.186-194
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• 2005

Purpose : Hepatitis A viral infections have been continued after re-emerging since mid 1990s in Korea. The incidence of this disease has been increased in young adults younger than 30 years of age since 2000. This study was performed to evaluate the prevalence of antibody to hepatitis A in Korea(two regions; Incheon and Changwon) in 2005, and was compared with the results of similar studies in mid 1990s. Methods : The study was conducted from January 2005 to June 2005, and consisted of 1,301 enrolled subjects, neonates to 50 years old, living in Incheon and Changwon in Korea. All sera were frozen and stored at $-70^{\circ}C$ until assayed. Anti-HAV IgG antibodies were measured by microparticle enzyme immunoassay(HAVAB, Abbott Lab., IL, USA). Results : The prevalence of anti-HAV IgG was 61.1% in infants younger than 1 year old, 30.5% in 1~5 years, 14.6% in 6~10 years, 1.7% in 11~15 years, 6.5% in 16~20 years, 36.6%in 21~30 years, 77.5% in 31~40 years, and 99.8% in 41~50 years. Statistical differences were not found between male and female, but there was statistical difference in 6~10 years old age group between the two areas. Conclusion : Our study indicate that the prevalence of antihepatitis A virus antibody has shifted from children to old adolescents and young adults. This result suggests that the risk of sudden outbreaks or increasing incidence of hepatitis A viral infections in young adults may be expected in our society. The preventive strategies of hepatitis A including vaccination should be prepared.

• Pediatric Infection and Vaccine
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• v.5 no.2
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• pp.239-244
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• 1998

Purpose : The incidence of hepatitis A virus infection in Korea has decreased recently. However, the prevalence in children and young adults is on an increasing trend in Inchon-Kyunggi prefecture. Economic development that leads to better living conditions and improves hygiene facilities has reduced the rate of HAV infection. This study was designed to evaluate the recent seroprevalence rate of hepatitis A in children and adolescents. Methods : Study population consisted of 612 children and adolescents aged 1 to 17 years in Inchon-Kyunggi prefecture. Serum samples were collected between 1996 and 1997 and tested for anti HAV by Microparticle Enzyme Immunoassay(MEIA). Results : According to age, the seropositive rates were 10.5%(male 13%, female 6.7%) in 1 year-old group, 0% in 3, 5, 11 and 13 year-old group, 6%(male 8%, female 4%) in 15 year-old group, and 11%(male 14%, female 8%) in 17 year-old group. Conclusion : This study showed that seropositive rate of HAV infection increased with age. While it revealed extremely low incidence of HAV infection in children less than 13 years old, they are also likely 10 be exposed 10 the infection. Our findings suggest that the effective administration of vaccination is needed in selected and high risk groups.