title: [Dynamic variations of hepatitis B virus polymerase gene in lamivudine-treated hepatitis B patients].
abstract: OBJECTIVE
  To study variation features of the hepatitis B virus polymerase gene in chronic hepatitis B patients before and after lamivudine treatment.
  
  
  METHODS
  From the serum samples of five CHB patients both before and after 12 months' lamivudine treatment, HBV polymerase gene was amplified and positive DNA fragments were cloned into JM105. Twenty positive clones of every sample were checked with mismatched polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and YMDD variants were sequenced.
  
  
  RESULTS
  Among five patients after 12 months lamivudine treatment, M552I mutations in two patients with HBV DNA rebounding and D553G mutation in one non-responder were detected except in two patients with negative HBV DNA.
  
  
  CONCLUSIONS
  D553G mutation is probably one of the reasons which caused non-responsiveness to the lamivudine treatment. The mutations of YMDD motif that occurred after lamivudine treatment are caused by the induction of the drug.
authors.affiliation: Hepatology Institute, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Feng
authors.forename: Lai
authors.initials: L
authors.lastname: Wei
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.forename: Fang-zheng
authors.initials: FZ
authors.lastname: Han
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D005260:Female; D015684:Gene Products, pol / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008297:Male; D008969:Molecular Sequence Data; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*
chemical_list: D015684:Gene Products, pol; C066027:P protein, Hepatitis B virus; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine