Publications by authors named "Hyun Jae Chung"

Kidney biopsy interpretation is the gold standard for the diagnosis and prognosis for kidney disease. Pathognomonic diagnosis hinges on the correct assessment of different structures within a biopsy that is manually visualized and interpreted by a renal pathologist. This laborious undertaking has spurred attempts to automate the process, offloading the consumption of temporal resources.

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Background: The aim of this study was to determine the prevalence of human papillomavirus (HPV) and 15 species that cause sexually transmitted infections (STIs) in negative cytology. In addition, we compared the diagnostic performance of multiplex polymerase chain reaction (PCR) with widely available techniques used to detect HPV.

Methods: We recruited 235 women of reproductive age who had negative cytology findings in a liquid-based cervical smear.

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We describe a matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS)-based assay for human papillomavirus (HPV) genotyping--the restriction fragment mass polymorphism (RFMP) assay, which is based on mass measurement of genotype-specific oligonucleotide fragments generated by TypeIIS restriction endonuclease cleavage after recognition sites have been introduced by PCR amplification. The use of a TypeIIS restriction enzyme makes the RFMP assay independent of sequence and applicable to a wide variety of HPV genotypes, because these enzymes have cleavage sites at a fixed distance from their recognition sites. After PCR amplification, samples are subjected to restriction enzyme digestion with FokI and BtsCI and desalting using Oasis purification plates, followed by analysis by MALDI-TOF MS.

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Background/aims: The objective of this study was to document the prevalence rate of occult hepatitis B virus (HBV) in healthy pregnant woman and the possibility of transmission to the foetus.

Methods: This study was performed prospectively with 202 healthy pregnant women. HBV-DNA testing was performed using two specific quantitative tests with two independent sets of sera and cord blood.

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Background: Infection with human papilloma virus (HPV) is the main cause of cervical cancer, and HPV genotyping is of increasing importance for determining clinical course and management of the disease based on the HPV genotypes. Here, we established a novel matrix-assisted laser desorption/ ionization time of flight mass spectrometry (MALDI-TOF MS) assay, termed restriction fragment mass polymorphism (RFMP) that is suitable for genotyping multiple HPV in an accurate and high-throughput manner. We evaluated the performance of the RFMP assay in HPV genotyping by comparing the results with those of direct or clonal sequencing and hybrid capture (HC) assays.

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Background/aims: Immunogenetic factors may play a role in determining the susceptibility of an individual to viral infection. CCR5 promoter polymorphisms are known to be associated with HIV infection. However, there has been no report on the association between CCR5 promoter polymorphism and HBV infection.

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A matrix-assisted laser desorption/ionization time-of-flight mass spectrometry-based genotyping assay, termed restriction fragment mass polymorphism (RFMP) has been recently developed for detecting hepatitis B virus (HBV) mutants. The assay is based on PCR amplification and mass measurement of oligonucleotides containing sites of mutations that confer resistance to lamivudine. We compared the efficacy and usefulness of the RFMP assay with a commercial assay using a reverse hybridization line probe technology, namely INNO-LiPA HBV DR (referred to henceforth as the LiPA assay), for the detection of lamivudine-resistant HBV mutants.

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Background: Identifying hepatitis C virus (HCV) genotypes has become increasingly important for determining clinical course and the outcome of antiviral therapy. Here we describe the development of restriction fragment mass polymorphism (RFMP) analysis, a novel matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) assay suitable for high-throughput, sensitive, specific genotyping of multiple HCV species.

Methods: The assay is based on PCR amplification and mass measurement of oligonucleotides containing genotype-specific motifs in the 5' untranslated region, into which a type IIS restriction endonuclease recognition was introduced by PCR amplification.

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Background/aims: Recent studies have shown that the genotype of hepatitis B virus (HBV) may correlate with the disease natural history and treatment outcome. However, several of these studies used low sensitivity assays in a small number of patients, and this has precluded an accurate evaluation of Korean HBV genotypes. We analyzed Korean HBV genotypes in a large population by employing a new technology, restriction fragment mass polymorphism (RFMP) using MALDI-TOF mass spectrometry, in a sensitive and specific manner.

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Background/aims: Mutations in hepatitis B virus (HBV) to lamivudine resistance that arise during prolonged treatment frequently cause amino acid substitutions in the YMDD motif of HBV DNA polymerase. Current methods of detecting such variants are time-consuming, labor intensive, and unsuitable for screening large numbers of samples. Here, we describe the development of a matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) genotyping assay suitable for detecting HBV variants in a sensitive and specific manner.

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