• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.422-429
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• 2022

The hepatitis C virus (HCV) genome contains a positive-sense single-stranded RNA molecule, and it is classified into 8 genotypes and 87 subtypes. Globally, over 350,000 people die from liver cirrhosis and hepatocellular carcinoma caused by HCV each year. Here, the genotype distribution of HCV was estimated in the population in Cheonan, Korea using Sanger sequencing. In addition, the correlation between HCV RNA level and genotype was assessed using real-time polymerase chain reaction (PCR); similarly, the correlation of HCV RNA level with isolation year (2007-2016) was determined using 463 consecutive serum samples obtained from patients at Dankook University Hospital, Cheonan, Korea. In 2007, genotype 1b (54.2%) was predominant, followed by genotypes 2a (41.7%), 1a (2.1%) and 3a (2.1%); whereas in 2016, the predominant genotype was 2a (49.0%), followed by genotypes 1b (46.9%), 3b (2%), and 4a (2%). Neither age nor sex was correlated with HCV genotype. Furthermore, the mean HCV RNA level decreased significantly from 2012 to 2016 (p < 0.05). However, no significant correlations between genotype and HCV RNA level were found. Overall, the findings revealed that genotypes 2a and 1b were the most common in Cheonan, and the prevalence of HCV genotype 1b tended to decrease over the past decade.

• Korean Journal of Veterinary Research
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• v.63 no.2
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• pp.15.1-15.5
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• 2023

The hepatitis A virus (HAV) induces severe acute liver injury and is adapted to human and monkey cell lines but not other cells. In this study, the HAV was inoculated into porcine kidney (PK-15) cells to determine its infectivity in porcine cells. The growth pattern of the HAV in PK-15 cells was compared with its growth pattern in fetal rhesus kidney (FRhK-4) cells. The growth of HAV was less efficient in PK-15 cells. In conclusion, HAV replication was verified in PK-15 cells for the first time. Further investigations will be needed to identify the HAV-restrictive mechanisms in PK-15 cells.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8665-8670
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• 2016

Background and Aims: Hepatitis B virus (HBV) reactivation was reported to be induced by transcatheter arterial chemoembolization (TACE) in HBV-related hepatocellular carcinonma (HCC) patients with a high incidence. The effective strategy to reduce hepatitis flares due to HBV reactivation in this specific group of patients was limited to lamivudine. This retrospective study was aimed to investigate the efficacy of prophylactic entecavir in HCC patients receiving TACE. Methods: A consecutive series of 191 HBV-related HCC patients receiving TACE were analyzed including 44 patients received prophylactic entecavir. Virologic events, defined as an increase in serum HBV DNA level to more than 1 log10 copies/ml higher than nadir the level, and hepatitis flares due to HBV reactivation were the main endpoints. Results: Patients with or without prophylactic were similar in host factors and the majorities of characteristics regarding to tumor factors, HBV status, liver function and LMR. Notably, cycles of TACE were parallel between the groups. Ten (22.7%) patients receiving prophylactic entecavir reached virologic response. The patients receiving prophylactic entecavir presented significantly reduced virologic events (6.8% vs 54.4%, p=0.000) and hepatitis flares due to HBV reactivation (0.0% vs 11.6%, p=0.039) compared with patients without prophylaxis. Kaplan-Meier analysis illustrated that the patients in the entecavir group presented significantly improved virologic events free survival (p=0.000) and hepatitis flare free survival (p=0.017). Female and Eastern Cooperative Oncology Group (ECOG) performance status 2 was the only significant predictors for virological events in patients without prophylactic antiviral. Rescue antiviral therapy did not reduce the incidence of hepatitis flares due to HBV reactivation. Conclusion: Prophylactic entecavir presented promising efficacy in HBV-related cancer patients receiving TACE. Lower performance status and female gender might be the predictors for HBV reactivation in these patients.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2019-2025
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• 2016

Hepatocellular carcinoma (HCC) is major health problem with high mortality rates, especially in patients with hepatitis B virus (HBV) infection. Telomerase function is one of common mechanisms affecting genome stability and cancer development. Recent studies demonstrated that genetic polymorphisms of telomerase associated genes such as telomerase associated protein 1 (TEP1) rs1713449 and PIN2/TERF1-interacting telomerase inhibitor 1 (PINX1) rs1469557 may be associated with risk of HCC and other cancers. In this study, 325 patients with HCC and 539 non-HCC groups [193 healthy controls, 80 patients with HBV-related liver cirrhosis (LC) and 266 patients with HBV-related chronic hepatitis (CH)] were enrolled to explore genetic polymorphisms of both SNPs using the allelic discrimination method based on MGB probe TaqMan real time PCR. We demonstrated that all genotypes of both genes were in Hardy-Wienberg equilibrium (P>0.05). Moreover, there was no significant association between rs1713449 genotypes and HCC risk, HCC progression and overall survival (P>0.05). Interestingly, we observed positive association of rs1469557 with risk of HCC when compared with the LC group under dominant (CC versus CT+TT, OR=1.89, 95% CI= 1.06-3.40, P=0.031) and allelic (C versus T alleles, OR=1.75, 95% CI=1.04-2.94, P=0.033) models, respectively. Moreover, overall survival of HCC patients with CC genotype of rs1469557 was significantly higher than non-CC genotype (Log-rank P=0.015). These findings suggest that PINX1 rs1469557 but not TEP1 rs1469557 might play a role in HCC progression in Thai patients with LC and be used as the prognosis marker to predict overall survival in HCC patients.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1756-1762
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• 2007

Envelope proteins of virus contain a segment of hydrophobic amino acids, called as fusion peptide, which triggers membrane fusion by insertion into membrane and perturbation of lipid bilayer structure. Potential fusion peptide sequences have been identified in the middle of L or M proteins or at the N-terminus of S protein in the envelope of human hepatitis B virus (HBV). Two 16-mer peptides representing the N-terminal fusion peptide of the S protein and the internal fusion peptide in L protein were synthesized, and their membrane disrupting activities were characterized. The internal fusion peptide in L protein showed higher activity of liposome leakage and hemolysis of human red blood cells than the N-terminal fusion peptide of S protein. Also, the membrane disrupting activity of the extracellular domain of L protein significantly increased when the internal fusion peptide region was exposed to N-terminus by the treatment of V8 protease. These results indicate that the internal fusion peptide region of L protein could activate membrane fusion when it is exposed by proteolysis.

• Korean Journal of Veterinary Research
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• v.25 no.2
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• pp.171-174
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• 1985

An outbreak of duck virus hepatitis was confirmed for the first time in Korea from ducklings having up to 40~65% mortality in less than 15-day-old ducklings of two farms located in the vicinity of Kwangju city. The infected ducks showed sudden death and opisthotonus position. The predominant gross lesions were found in the liver, showing enlargement and petechial or ecchymotic hemorrhages. The microscopic findings were consisted of fatty changes and necrosis of the hepatic cells, and proliferation of the bile duct epithelium. The presence of the virus was detected by electron microscopy of the sera and livers of infected ducks. The duck embryo and the ducks inoculated with the liver materials from the infected ducks showed the same lesions with those of the naturally infected ducks.

• The Korean Journal of Medicine
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• v.99 no.3
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• pp.140-144
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• 2024

Hepatitis B virus (HBV) reactivation associated with various therapeutic interventions is a significant cause of morbidity and mortality among patients with current or resolved HBV infection. Since no curative treatment for HBV infection is currently available, a large number of individuals in the general population are at risk for HBV reactivation. Populations vulnerable to HBV reactivation include those currently infected with HBV or those who have had past exposure to the virus. The potential consequences of HBV reactivation are particularly concerning when these populations undergo anti-cancer chemotherapy, immunosuppressive or immunomodulatory therapies for managing various malignancies, rheumatologic diseases, inflammatory bowel disease, or undergo solid-organ or hematologic stem cell transplantation. This article aims to increase awareness of HBV reactivation and to elucidate the mechanisms and risks associated with HBV reactivation in various clinical settings.

• BMB Reports
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• v.29 no.2
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• pp.175-179
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• 1996

Viral surface proteins are known to play an essential role in attachment of the virus particle to the host cell membrane. In case of the hepatitis B virus (HBV) several reports have described potential receptors on the target cell side, but no definite receptor protein has been isolated yet. As for the viral side, it has been suggested that the preS region of the envelope protein, especially the preS1 region, is involved in binding of HBV to the host cell. In this study, preS1 region was recombinantly expressed in the form of a maltose binding protein (MBP) fusion protein and used to identify and visualize the expression of putative HBV receptor(s) on the host cell. Using laser scanned confocal microscopy and by FACS analysis, MBP-preS1 proteins were shown to bind to the human hepatoma cell line HepG2 in a receptor-ligand specific manner. The binding kinetic of MBP-preS1 to its cellular receptor was shown to be temperature and time dependent. In cells permeabilized with Triton X-100 and treated with the fusion protein, a specific staining of the nuclear membrane could be observed. To determine the precise location of the receptor binding site within the preS1 region, several short overlapping peptides from this region were synthesized and used in a competition assay. In this way the receptor binding epitope in preS1 was revealed to be amino acid residues 27 to 51, which is in agreement with previous reports. These results confirm the significance of the preS1 region in virus attachment in general, and suggest an internalization pathway mediated by direct attachment of the viral particle to the target cell membrane.

• Journal of Microbiology and Biotechnology
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• v.34 no.2
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• pp.233-239
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• 2024

N6-methyladenosine (m6A) RNA methylation has recently emerged as a significant co-transcriptional modification involved in regulating various RNA functions. It plays a vital function in numerous biological processes. Enzymes referred to as m6A methyltransferases, such as the methyltransferase-like (METTL) 3-METTL14-Wilms tumor 1 (WT1)-associated protein (WTAP) complex, are responsible for adding m6A modifications, while m6A demethylases, including fat mass and obesity-associated protein (FTO) and alkB homolog 5 (ALKBH5), can remove m6A methylation. The functions of m6A-methylated RNA are regulated through the recognition and interaction of m6A reader proteins. Recent research has shown that m6A methylation takes place at multiple sites within hepatitis B virus (HBV) RNAs, and the location of these modifications can differentially impact the HBV infection. The addition of m6A modifications to HBV RNA can influence its stability and translation, thereby affecting viral replication and pathogenesis. Furthermore, HBV infection can also alter the m6A modification pattern of host RNA, indicating the virus's ability to manipulate host cellular processes, including m6A modification. This manipulation aids in establishing chronic infection, promoting liver disease, and contributing to pathogenesis. A comprehensive understanding of the functional roles of m6A modification during HBV infection is crucial for developing innovative approaches to combat HBV-mediated liver disease. In this review, we explore the functions of m6A modification in HBV replication and its impact on the development of liver disease.

• Kidney Research and Clinical Practice
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• v.37 no.4
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• pp.323-337
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• 2018

Infectious complications have been considered as a major cause of morbidity and mortality after kidney transplantation, especially in the Asian population. Therefore, prevention, early detection, and prompt treatment of such infections are crucial in kidney transplant recipients. Among all infectious complications, viruses are considered to be the most common agents because of their abundance, infectivity, and latency ability. Herpes simplex virus, varicella zoster virus, Epstein-Barr virus, cytomegalovirus, hepatitis B virus, BK polyomavirus, and adenovirus are well-known etiologic agents of viral infections in kidney transplant patients worldwide because of their wide range of distribution. As DNA viruses, they are able to reactivate after affected patients receive immunosuppressive agents. These DNA viruses can cause systemic diseases or allograft dysfunction, especially in the first six months after transplantation. Pretransplant evaluation and immunization as well as appropriate prophylaxis and preemptive approaches after transplant have been established in the guidelines and are used effectively to reduce the incidence of these viral infections. This review will describe the etiology, diagnosis, prevention, and treatment of viral infections that commonly affect kidney transplant recipients.