• Molecules and Cells
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• 제21권3호
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• pp.330-336
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• 2006

Since its identification in 1989, hepatitis C virus has been the subject of extensive research. The biology of the virus and the development of antiviral drugs are closely related. The RNA polymerase activity of nonstructural protein 5B was first demonstrated in 1996. NS5B is believed to localize to the perinuclear region, forming a replicase complex with other viral proteins. It has a typical polymerase structure with thumb, palm, and finger domains encircling the active site. A de novo replication initiation mechanism has been suggested. To date, many small molecule inhibitors are known including nucleoside analogues, non-nucleoside analogues, and pyrophosphate mimics. NS5B interacts with other viral proteins such as core, NS3, 4A, 4B, and 5A. The helicase activity of NS3 seems necessary for RNA strand unwinding during replication, with other nonstructural proteins performing modulatory roles. Cellular proteins interacting with NS5B include VAMP-associated proteins, heIF4AII, hPLIC1, nucleolin, PRK2, ${\alpha}$-actinin, and p68 helicase. The interactions of NS5B with these proteins might play roles in cellular trafficking, signal transduction, and RNA polymerization, as well as the regulation of replication/translation processes.

• 보건교육건강증진학회지
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• 제5권2호
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• pp.90-109
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• 1988

This study was carried out to find the influencing factors on the acceptance of vaccination of viral hepatitis type B. Two groups of students, 362 undergraduates of Korea University were surveyed for research. The compliant group was 156 students who were inoculated with viral hepatitis type B shot more than one time. The non-compliant group was 206 students who were not inoculated. The measures used for this study were Multidimensional Health Locus of Control Scales and the one developed by the researcher on the basis of literature review about Health Belief Model. The results of this stuby were as follows. The awareness on health of the compliant group was higher than that of the non-compliant group(t=0.39, P<0.05), And perceived barrier of the compliant group was lower than that of the non-compliant group(t=0.35, P<0.05). But the knowledge about the viral hepatitis type B of the compliant group was lower than that of the non-compliant group(t=2.49, P<0.05). There were no differences between two groups in the perceived susceptibility of the hepatitis and the perceived benifit of the hepatitis vaccination. There was no difference between two groups in terms of the Inner Health Locus of Control (HLOC) and Chance HLOC. On the other hand Powerful-Others HLOC of the compliant group was higher than that of the non-compliant group(t=3.67, P<0.05). 'Parent's advice' was found to be the major answer to the motive of being vaccinated in the compliant group. This explains that the most influencial factor in determining one's health behavior is the parent's opinion. Answers to the question of the reason of not being vaccinated were, 'did not want to bother' and 'did not care yet' in order. As a whole, except for the awareness on health and the perceived barrier of the hepatitis vaccination, this study result shows disagreement with the past investigations on the inter-relationship between one's health belief or Health Locus of Control and the health behavior. The author of this study believes this was due to the limitation in the survey group's particular homogenity.

• BMB Reports
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• 제33권1호
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• pp.59-62
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• 2000

Hepatitis C virus (HCV) nonstructural 5B (NS5B) protein is an RNA-dependent RNA polymerase (RdRp). To determine whether it can contribute to viral replication by interaction with cellular proteins, the yeast two-hybrid screening system was employed to screen a human liver cDNA library. Using the HCV NS5B as a bait, we have isolated positive clones encoding a cellular protein. The NS5B interacting protein, 5BIP, is a novel cellular protein of 170 amino acids. Interaction of the HCV NS5B protein with 5BIP was confirmed by a protein-protein blotting assay. Recently, we have demonstrated that NS5B possesses an RdRp activity and thus it is possible that 5BIP, in association with NS5B, plays a role in HCV replication.

• 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.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 추계학술대회
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• pp.87-88
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• 2003

PegIntron is the pegylated form of human recombinant interferon alfa-2b (IFN${\alpha}$2b). IFN ${\alpha}$2b, known as Intron A, has been in approved clinical use since the 1980's for various cancer indications, and for the treatment of Hepatitis C. In the mid 1990's, several clinical investigators reported that combination therapy with ribavirin and Intron A dramatically increased the therapeutic efficacy for treatment of Hepatitis C.(omitted)

• The Korean Journal of Physiology and Pharmacology
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• 제17권5호
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• pp.375-383
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• 2013

Hepatocellular carcinoma (HCC) related to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections is thought to account for more than 80% of primary liver cancers. Both HBV and HCV can establish chronic liver inflammatory infections, altering hepatocyte and liver physiology with potential liver disease progression and HCC development. Cyclophilin A (CypA) has been identified as an essential host factor for the HCV replication by physically interacting with the HCV non structural protein NS5A that in turn interacts with RNA-dependent RNA polymerase NS5B. CypA, a cytosolic binding protein of the immunosuppressive drug cyclosporine A, is overexpressed in many cancer types and often associated with malignant transformation. Therefore, CypA can be a good target for molecular cancer therapy. Because of antiviral activity, the CypA inhibitors have been tested for the treatment of chronic hepatitis C. Nonimmunosuppressive Cyp inhibitors such as NIM811, SCY-635, and Alisporivir have attracted more interests for appropriating CypA for antiviral chemotherapeutic target on HCV infection. This review describes CypA inhibitors as a potential HCC treatment tool that is contrived by their obstructing chronic HCV infection and summarizes roles of CypA in cancer development.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제15권2호
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• pp.63-73
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• 2012

Development of antiviral resistance to lamivudine is the most important factor for the treatment failure. It is necessary to establish proper guidelines to overcome drug resistance for children with chronic hepatitis B. Primary treatment with lamivudine should be considered if patients are in immune-clearance phase and have persistently elevated ALT levels more than twice the upper limit of normal value. Before initiating the therapy, careful consideration of the patient's status is required to exclude abnormal liver function tests due to other causes. The treatment option should be carefully decided to suppress the viral replication effectively. To obtain good compliance, clinicians should educate patients and their parents. Appropriate monitoring for virologic breakthrough and genotypic resistance is important in deciding to change the treatment plan. Sequential monotherapy should be avoided and a combination of drugs in other categories is recommended. New antiviral agents, such as entecavir and tenofovir, which have high potency and high genetic barrier, are soon expected to be available for use with children.

• Biomolecules & Therapeutics
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• 제9권1호
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• pp.55-62
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• 2001

CJC-50100 is a recombinant hepatitis B virus surface antigen (HBsAg) expressed in yeast. The general pharmacological properties of CJC-50100 were evaluated in mice, rats, dogs and isolated guinea pig ileum. The doses were 0.33~33.3 $\mu$g/kg i.m. for mice and rats and 3.3~9.9 $\mu$g/kg i.v. for dogs. The concentrations of 0.002~0.02 $\mu$g/ml were used for the assay with guinea pig ileum. Intramuscular administration of CJC-50100 at the doses did not alter general behavior and the responses for central nervous system, smooth muscle, gastrointestinal system, cardiovascular and respiratory system, and water and electrolytes excretion. In summary, CJC-50100 had no pharmacological effect in these studies even up to the 100-fold of the expected clinical dose, 20 $\mu$g/man/60 kg.

• IMMUNE NETWORK
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• 제3권1호
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• pp.23-28
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• 2003

Background: Intracellular antibody specific to hepatitis B virus X protein (HBx) might be useful for studying the role of HBx in hepatocellular carcinogenesis and HBV replication. Methods: With variable region genes for H7 monoclonal anti-HBx Ab, we constructed a vector for bacterial expression of single chain Ab (scFv) and a vector for eukaryotic cell expression of it. The expression of H7 scFv and its binding activity against HBx was examined by immunoblotting and immunofluorescence microscopy. Results: H7 scFv expressed in bacterial cells retained reactivity to HBx. We demonstrated its intracytoplasmic expression in CosM6 eukaryotic cells. Conclusion: This is the first study showing the expression of intracellular anti-HBx Ab in eukaryotic cells. H7 scFv may be a good tool to study the function of HBx in HBV infection.

• 한국미생물·생명공학회지
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• 제21권2호
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• pp.171-175
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• 1993

The antioxidant in the oriental drug, NP-S, traditionally used as a therapeutic agent for Hepatitis B was identified. The NP-S was divided into two fractions at molecular weight cut-off of 1000 by ultrafiltration and the fraction having molecular weight less than 1000 was named as NP-S(l)10. Both NP-S and NP-S(l)10 had antioxidant activity. An antioxidant that was extracted by chloroform from water-insoluble fraction in lyophilized NP-S(l)10 had a little smaller activity than NP-S(l)10 and identified as cyclooctasulfur(S8) by mass spectrum.