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Báo cáo y học: "Hepatitis B Virus e Antigen Variants"

Tuyển tập các báo cáo nghiên cứu khoa học ngành y học tạp chí Medical Sciences dành cho các bạn sinh viên ngành y tham khảo đề tài: Hepatitis B Virus e Antigen Variants. | Int. J. Med. Sci. 2005 2 1 2 International Journal of Medical Sciences ISSN 1449-1907 www.medsci.org 2005 2 1 2-7 2005 Ivyspring International Publisher. All rights reserved Review Received 2004.10.01 Accepted 2005.01.01 Published 2005.01.05 Abstract Key words Author biography Corresponding address Hepatitis B Virus e Antigen Variants Shuping Tong 1 Kyun-Hwan Kim1 Charles Chante 2 Jack Wands1 and Jisu Li 1 1. Liver Research Center Rhode Island Hospital Brown Medical School Providence RI 02903 USA. 2. Cardinal Santos Medical Center Metro Manila 1500 Philippines. More than 300 million people worldwide are chronically infected with hepatitis B virus HBV . Considering the very short generation time for a virus and the high error rate associated with the reverse transcription step of HBV replication decades of HBV infection are probably equivalent to million years of human evolution. The most important selective force during the natural course of HBV infection appears to be the immune response. The development of anti-HBe antibody in hepatitis B patients usually correlates with reduction of HBV viremia. As a consequence escape mutants of anti-HBe are selected. The core promoter mutants express less HBe antigen HBeAg through transcriptional down regulation while precore mutants express truncated products. We recently identified additional mutations that modulate HBeAg translation initiation proteolytic cleavage and secondary structure maintenance through a disulfide bond. The core promoter mutants have been associated with the development of fulminant hepatitis during acute infection and liver cancer during chronic infection. Consistent with their enhanced pathogenicity core promoter mutants were found to replicate at up to 10-fold higher levels in transfected human hepatoma cells than the wild-type virus. Moreover some core promoter mutants are impaired in virion secretion due to missense mutations in the envelope gene. These virological properties may help explain .