نتایج جستجو برای: precore

تعداد نتایج: 438  

Journal: :Mathematics 2023

Taking into account the definition of precore, we initially analyze its non-emptiness using duality results from linear programming theory. We then introduce dominance core to investigate coincident relations between precore and core. Finally, propose specific reduction approaches axiomatize precore.

2015
Andrea Caballero Josep Gregori Maria Homs David Tabernero Carolina Gonzalez Josep Quer Maria Blasi Rosario Casillas Leonardo Nieto Mar Riveiro-Barciela Rafael Esteban Maria Buti Francisco Rodriguez-Frias Golo Ahlenstiel

This study assesses the presence and outcome of genotype mixtures in the polymerase/surface and X/preCore regions of the HBV genome in patients with chronic hepatitis B virus (HBV) infection. Thirty samples from ten chronic hepatitis B patients were included. The polymerase/surface and X/preCore regions were analyzed by deep sequencing (UDPS) in the first available sample at diagnosis, a pre-tr...

Journal: :Journal of Korean Medical Science 1999
S. W. Cho Y. J. Shin K. B. Hahm J. H. Jin Y. S. Kim J. H. Kim H. J. Kim

To investigate the role of mutant hepatitis B virus (HBV) in the development of hepatocellular carcinoma (HCC), 20 patients with HCC were studied for precore and core promoter mutations in tumorous and nontumorous tissues. The precore and core promoter region was amplified and analyzed by direct sequencing. Among the 20 tumorous and nontumorous tissues, precore mutant HBV was found in 12 (60%) ...

Journal: :Virology 1997
P P Scaglioni M Melegari J R Wands

It is now well recognized that mutations in the hepatitis B virus (HBV) genome occur during the natural course of chronic viral infection. Regions of the viral genome that are frequently affected by such mutations, rearrangements, and/or deletions generally involve the precore promoter, precore, and core as well as the preS gene regions. However, little is known regarding the biologic consequen...

Journal: :Hepatology 1999
H L Chan M Hussain A S Lok

Mutations in the core promoter and precore regions are frequently found in hepatitis B e antigen (HBeAg)-negative patients, but precore stop codon mutation is restricted to hepatitis B virus (HBV) genotypes that have T at nucleotide 1858. The aims of this study were to determine the role of core promoter and/or precore mutations in HBeAg seroconversion and their impact on the subsequent course ...

Journal: :Journal of virology 1999
Y Y Zhang J Summers

A precore-deficient mutant of duck hepatitis B virus (DHBV) produced by site-directed mutagenesis was tested for its ability to compete with wild-type virus in a mixed infection of 3-day-old ducklings. The mutation was shown to produce a cis-acting defect, resulting in a replication rate that was about one-half that of wild-type virus. Accordingly, wild-type virus was rapidly selected during th...

1994
Kwang Cheol Koh Hyo-Suk Lee Chung Yong Kim

OBJECTIVES It has been controversial whether or not the emergence of precore mutant HBV is related to the severe form of chronic hepatitis B (CH-B). To further clarify the role of the precore mutant HBV in the natural course of CH-B, we conducted a longitudinal analysis of precore-region sequences according to the biochemical severity along with seroconversion to anti-HBe in patients with CH-B....

2009
Jing Zhang Wei-Jia Xu Qing Wang Yong Zhang Ming Shi

This study investigated the prevalence of the precore G1896A mutation in Chinese patients with hepatitis B e antigen (HBeAg) negative HBV infection and its relation to serum HBV pre-S1 antigen. The overall prevalence of the precore G1896A mutation was 72.6% in HBeAg-negative Chinese patients with detectable serum HBV DNA. The prevalence of the precore G1896A is significantly higher in Chinese H...

2017
Ali Kargar Kheirabad Gholamreza Farshidfar Sadegh Nasrollaheian Hamed Gouklani

INTRODUCTION Mutation of the HBV precore gene prevents the production of HBeAg, which is an important target for immune responses. Distribution of this mutation varies along with frequency of HBV genotypes in accordance with geographic and ethnic variations. The general objective of this study was to evaluate the prevalence and characteristics of precore mutation in Iran and its correlation wit...

Journal: :Virology 2014
Marion Duriez Anne Thouard Stéphane Bressanelli Jean-Michel Rossignol Delphine Sitterlin

The Hepatitis B virus Precore protein, present in the secretory pathway as the HBeAg precursor, can associate in the cytoplasm with the Core protein to form heterocapsids, likely to favor viral persistence. Core and Precore proteins share their primary sequence except for ten additional aminoacids at the N-terminus of Precore. To address the role of this propeptide sequence in the formation of ...

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