• 대한의생명과학회지
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• 제18권3호
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• pp.283-290
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• 2012

In this study, we investigated the virological characteristics, HBV DNA levels and presence of mutations of "a" determinant in the HBsAg S gene in chronic hepatitis B patients with coexisting HBsAg and anti-HBs. The 18 patients who were diagnosed with chronic hepatitis B were both positive for HBsAg and anti-HBs. HBV Among them, 15 patients were DNA positive. The median of HBV DNA levels in serum was $2.18{\times}10^7$ copies/mL with the HBsAg+/anti-HBsAb+ patients. Also, 4 of 8 HBeAg negative patients had HBV DNA levels higher than $10^4$ copies/mL and the median of HBV DNA levels was $2.03{\times}10^6$ copies/mL, which were significantly high. These results showed that viral replication still existed in most of the patients of the concomitant HBsAg and anti-HBs, and even in the some HBeAg negative patients. Furthermore, mutation within the "a" determinant of HBV were found in 7 of 15 patients. The most frequent changes were located at positions aa126. In addition, one mutation observed for HBsAg only positive.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.386-392
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• 1999

A large-scale culture of hepatitis A virus in human diploid MRC-5 cells was conducted. In a roller bottle culture, the virus was grown to a maximum titer in 3 weeks after infection. Over 95％ of the cell-associated virus was excreted after culturing the infected cells in suspension media without fetal bovine serum for 3 days. The cultured virus was inactivated with formalin, concentrated by ultrafiltration, and partially purified by ultracentrifugation in a non-ionic gradient medium of Renocal. Two separate peak fractions showing high anti-HAY ELISA titer were pooled and about 40％ of HAV antigen was recovered by this purification procedure. Of the partially purified vaccine, the protein pattern in SDS-PAGE and immunogenicity in mice were compared with a commercial HAV vaccine. In SDS-PAGE, the purified vaccine in this study and the commercial vaccine showed almost the same protein pattern. The seroconversion rate of the purified vaccine in mice was not different from that of the commercial vaccine. Therefore, we could prepare a good grade of HAV vaccine by a simple purification procedure although the purification itself was not completed.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.178-178
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• 1996

Hepatitis B virus (HBV) infection is one of the serious problems in Southeast Asia including Korea because it causes chronic hepatitis, which can easily be transformed In fatal conditions such as cirrhosis and hepatoma. Even though lots of informations on structural characteristics and gene expression mechanisms have been accumulated, the mechanism for HBV-induced hepatocellular injury which is believed to be the consequences of the immunological response is not well understood. In order tn perform immunopathological studies for prevention and treatment of HBV infection, we designed transgenic mice as a disease model which can mimic HBV infection, In this study, a promoter-HBV DNA fragment for the preparation of HBV transgenic mice has been constructed. To add a proper enzyme site on 5' end of HBV gene, total HBV (subtype adr) gene was inserted into BamHI site of pBluescript SK vector and reextracted by PstI-SacI treatment A liver-specific promoter, rat ${\alpha}$ 2u globulin gene promoter, was insrted to pBluescript SK vector and reextracted by BamHI-PstI treatment, Promoter-HBV DNA was constructed by ligation of two fragments using identical PstI sites. For large scale production of promoter-HBV DNA, it was inserted to BamHI-SacI site of pBluescript SK vector.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.210-217
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• 2018

A one-step multiplex reverse transcription PCR (RT-PCR) method comprising six primer sets (for the detection of norovirus GI and GII, hepatitis A virus, rotavirus, and astrovirus) was developed to simultaneously detect four kinds of pathogenic viruses. The size of the PCR products for norovirus GI and GII, hepatitis A virus (VP3/VP1 and P2A regions), rotavirus, and astrovirus were 330, 164, 244, 198, 629, and 449 bp, respectively. The RT-PCR with the six primer sets showed specificity for the pathogenic viruses. The detection limit of the developed multiplex RT-PCR, as evaluated using serially diluted viral RNAs, was comparable to that of one-step single RT-PCR. Moreover, this multiplex RT-PCR was evaluated using food samples such as water, oysters, lettuce, and vegetable product. These food samples were artificially spiked with the four kinds of viruses in diverse combinations, and the spiked viruses in all food samples were detected successfully.

• IMMUNE NETWORK
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• 제10권4호
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• pp.120-125
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• 2010

Dysfunction of the virus-specific T cells is a cardinal feature in chronic persistent viral infections such as one caused by hepatitis C virus (HCV). In chronic HCV infection, virus-specific dysfunctional CD8 T cells often overexpress various inhibitory receptors. Programmed cell death 1 (PD-1) was the first among these inhibitory receptors that were identified to be overexpressed in functionally impaired T cells. The roles of other inhibitory receptors such as cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and T cell immunoglobulin and mucin domain-containing molecule 3 (Tim-3) have also been demonstrated in T-cell dysfunctions that occur in chronic HCV patients. Blocking these inhibitory receptors in vitro restores the functions of HCV-specific CD8 T cells and allows enhanced proliferation, cytolytic activity and cytokine production. Therefore, the blockade of the inhibitory receptors is considered as a novel strategy for the treatment of chronic HCV infection.

• Clinical and Experimental Pediatrics
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• 제55권3호
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• pp.77-82
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• 2012

Human astrovirus (HAstV) is a major cause of acute diarrhea among children, resulting in outbreaks of diarrhea and occasionally hospitalization. Improved surveillance and application of sensitive molecular diagnostics have further defined the impact of HAstV infections in children. These studies have shown that HAstV infections are clinically milder (diarrhea, vomiting, fever) than infections with other enteric agents. Among the 8 serotypes of HAstV identified, serotype 1 is the predominant strain worldwide. In addition to serotype 1, the detection rate of HAstV types 2 to 8 has increased by using newly developed assays. HAstV is less common compared with other major gastroenteritis viruses, including norovirus and rotavirus; however, it is a potentially important viral etiological agent with a significant role in acute gastroenteritis. A better understanding of the molecular epidemiology and characteristics of HAstV strains may be valuable to develop specific prevention strategies.

• Molecules and Cells
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• 제22권1호
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• pp.13-20
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• 2006

Hepatitis C virus (HCV) non-structural protein 5A protein (NS5A), which consists of three functional domains, is involved in regulating viral replication, interferon resistance, and apoptosis. Recently, the three-dimensional structure of the domain 1 was determined. However, currently the molecular basis for the domains 2 and 3 of HCV NS5A is yet to be defined. Toward this end, we expressed, purified the domain 2 of the NS5A (NS5A-D2), and then performed biochemical and structural studies. The purified domain 2 was active and was able to bind NS5B and PKR, biological partners of NS5A. The results from gel filtration, CD analysis, 1D $^1H$ NMR and 2D $^1H-^{15}N$ heteronuclear single quantum correlation (HSQC) spectroscopy indicate that the domain 2 of NS5A appears to be flexible and disordered.

• Bulletin of the Korean Chemical Society
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• 제20권3호
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• pp.301-306
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• 1999

Hepatitis C virus (HCV) has been known to be an enveloped virus with a positive strand RNA genome and the major agent of the vast majority of transfusion associated cases of hepatitis. For viral replication, HCV structural proteins are first processed by host cell signal peptidases and NS2/NS3 site of the nonstructural protein is cleaved by a zinc-dependent protease NS2 with N-terminal NS3. The four remaining junctions are cleaved by a separate NS3 protease. The solution conformations of NS4B/5A, NS5A/5B substrates and NS5A/5B inhibitor have been determined by two-dimensional nuclear magnetic resonance (NMR) spectroscopy. NMR data suggested that the both NS5A/5B substrate and inhibitor appeared to have a folded tum-like conformation not only between P1 and P6 position but also C-terminal region, whereas the NS4B/5A substrate exhibited mostly extended conformation. In addition, we have found that the conformation of the NS5A/5B inhibitor slightly differs from that of NS5A/5B substrate peptide, suggesting different binding mode for NS3 protease. These findings will be of importance for designing efficient inhibitor to suppress HCV processing.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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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.

• 한국약용작물학회지
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• 제17권2호
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• pp.133-138
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• 2009

Nelumbo nucifera (lotus) is known to be a useful medicinal plant and leaf extract contains several flavonoids and alkaloids. To analyze the effect of Nelumbo nucifera leaves extract (NNL) on the HBsAg production, we treated NNL on HepG2.2.15 cells which contain the hepatitis B viral genome and secrete surface antigen into media. NNL suppressed the production of hepatitis B surface antigen as a dose-dependent manner. To analyze the effect of NNL on HBV DNA replication, PCR analysis was performed. NNL was not affected the HBV DNA replication and HBsAg mRNA expression. To understand the effect of NNL on the production of HBsAg, we carried out the analysis of lipid-metabolizing gene expression using one-step RT-PCR. NNL reduced the gene expression of FASN and SREBP2 and increased the expression of LDLR. Triglyceride content of HepG2.2.15 cells was not decreased by treatment of NNL. This result suggests a possibility that NNL may have an effect for the inhibition of hepatitis B surface antigen by modulation of lipid and cholesterol metabolism.