[Detection and significance of gene variation in hepatitis B virus S region].

OBJECTIVE: To explore the variations of gene S in hepatitis B viruses of hepatitis B patients and provide experimental evidences for the mutation analysis of viral gene. METHODS: The virus DNA load in hepatitis B patient donors was detected by real-time polymerase chain reaction (PCR) and gene sequence analysis. And a comparison was made with standard strain by the software DNAstar. RESULTS: (1) Gene S was successfully amplified and sequenced in 15 hepatitis B patients. Three samples had I→T mutation at residue 126 in HBsAg "a" antigenic determinant. (2) Sixteen hepatitis B patients had 67 nucleotide mutations, including 14 residues in PreS1 and 6 residues in PreS2. Mutations nt 3036 T→C, nt 3039 T→G, nt 3066 C→T and L88V existed in PreS1 gene in all samples. CONCLUSION: HBV genome is susceptible to nucleotide mutations. Some residues have geographically restricted mutations in gene S region. And understanding the significance of these mutations may help clarify the pathogenesis of hepatitis B and provide new experimental evidence for its gene diagnosis and prevention.

[Study on hepatitis C virus genotypes in Yantai district, Shandong province].

OBJECTIVE: To understand the hepatitis C virus (HCV) genotype distribution in Yantai district of Shandong province, and to explore whether the HCV genotypes was relevant to the injure of liver through the index of liver function. METHODS: Using specific PCR primers to amplify the HCV RNA 5' UTR/NS5B,then PCR products were sequenced by genetic analyzer. The genotypes were identified by alignment to the GenBank reference sequences and construction the phylogenetic tree of 5' UTR. RESULTS: Among 9 unpaid blood donors we detected two kinds of genotypes of 1b and 3a, respectively, 8 cases (88.9%) and 1 case (11.1%). Among 33 cases of hepatitis C patients we detected the 1b, 2a and 6a the three kinds of genotypes, respectively, 22 (66.7%), 10 (30.3%) and 1 (3.03%) cases. Subtype 1b is the advantage of popular genotype in HCV carriers from Yantai district, and the distribution of 1b was no significant difference in the different population (chi2 = 0.796, P = 0.373); The difference of indicator of liver damage in the different genotypes of subjects were significant (P < 0.05), the mean of ALT, AST of 2a-subtype carriers was significantly higher than the 1b-subtype population. CONCLUSIONS: The genetic diversity of HCV in Shandong Yantai district was presented. The main genotypes were 1b-subtype, and 3a and 6a-subtype was detected firstly. The genotype of HCV were relevant to the liver damage indicators, 2a-subtype hepatitis C virus infection in the liver cells may play an important role in the disease process.