Caspase 3 ; metabolism ; Child ; Female ; Glomerulonephritis, Membranous ; enzymology ; etiology ; pathology ; virology ; Hepatitis B ; complications ; pathology ; Hepatitis B virus ; Humans ; Male

The nature of hepatitis B virus (HBV) particle associated DNA polymerase was studied in relation to various enzyme inhibitors including antiviral agents. HBV DNA polymerase required high concentration of MgCl2(> 30 mM) and neutral pH for its full activity. p-chloromercuribenzoate was a strong inhibitor (85% inhibition at 1 mM) but N-ethylmaleimide had much less inhibitory effect (20% inhibition at 10 mM). Phosphonoformic acid showed the greatest inhibitory effect on HBV-DNA polymerase (almost complete inhibition at 100 microM) among phosphocompounds tested. Adenine arabinoside triphosphate (ara-ATP) and cytosine arabinoside triphosphate (ara-CTP) were competitive inhibitors with respect to their respective deoxyribonucleoside triphosphate (dATP and dCTP). Ara-CPT was a stronger inhibitor of HBV-DNA polymerase compared to ara-ATP. Ki values for ara-ATP and ara-CTP were 15.0 microM and 11.7 microM , respectively. HBV-DNA polymerase is characteristic in its ionic requirements and susceptibilities to certain inhibitors.
DNA-Directed DNA Polymerase/antagonists & inhibitors ; DNA-Directed DNA Polymerase/metabolism* ; Hepatitis B Virus/enzymology* ; Human

<b>OBJECTIVEb>To explore the possibility of transacting hepatitis D virus (HDV) ribozyme cleaving in vitro the hepatitis B virus (HBV) mRNA fragments.

<b>METHODSb>According to the established pseudoknot-like structure, its' H1 domain was changed to design the transacting HDV ribozyme Rc1 and Rc2, which targeted the 701-713 site and 776-788 site of HBV C domain. After the chemically synthesised cDNA of the ribozyme was cloned into the vector PGEM-4Z, the transacting HDV ribozyme was transcriped using in vitro transcription technology. The in vitro cleavage characteristics of the ribozyme were studied and the kinetic parameters (Kcat and Km) were determined by Eadie Hofstee plotting.

<b>RESULTSb>Both the two ribozymes had the ability to cleave the substrate, the cleavage percentage at 37 degrees for 90 minutes were 50% and 51%. According to the Eadie Hofstee plot, the Km of the Rc1 and Rc2 were 0.61 micromol and 0.58 micromol, the Kcat were 0.64 x min(-1) and 0.60 x min(-1),respectively.

<b>CONCLUSIONSb>The cleaving ability of trans-acting HDV ribozyme on non-HDV RNA fragment was tested. The results showed a new potential of the antisense antisense regent for HBV gene therapy.

DNA, Antisense ; genetics ; Genome, Viral ; Hepatitis B virus ; genetics ; Hepatitis Delta Virus ; enzymology ; genetics ; Humans ; RNA, Catalytic ; genetics ; metabolism ; RNA, Messenger ; genetics ; RNA, Viral ; genetics ; Transcription, Genetic

<b>OBJECTIVEb>To investigate the correlation between spontaneous clearance of HBV DNA and the levels of Alanine Aminotransferase (ALT) in chronic hepatitis B (CHB) patients.

<b>METHODSb>Retrospective review analysis was used in this research. A total of 177 CHB patients with HBV DNA>1x10(4) copies/ml and ALT>800 U/L were recruited in this study and were divided randomly into two groups, 84 patients in control group (received lamivudine therapy) while 96 cases in study group (without anti-viral therapy), the dynamic changes of HBV DNA and HBV markers in these two groups were compared.

<b>RESULTSb>The clinical data of CHB patients were retrospected and followed up in 24 weeks. The negative conversion cases of HBV DNA are 62 (87.3%) in study group and 56 cases (78.87%) in control group at week 24, the negative conversion cases of HBV DNA are 56 (78.9%) in study group and 60 (92.3%) cases in control at week 8. No significant difference (x2=0.058, P>0.05) existed between these two groups. Among 43 patients with HBV DNA is less than or equal to 6 log10 copies/ml, 41 (95.3%) patients converted negatively, while in 28 patients with HBV DNA is more than 6 log10 copies/ml, 21 (75.0%) patients converted negatively. The negative conversion rate of HBV DNA is more than 6 log10 copies/ml was lower than the other group at week 24. The difference between the two groups was significant (x2=0.024, P<0.05). 41 patients with hepatitis B e antigen (HBeAg) negative and 30 patients with HBeAg positive were included in antiviral group. The negative conversion cases of HBV DNA of the former are 36 (87.8%) and the latter are 26 (86.7%). No significant difference found between them (x2=1, P>0.05). HBeAg loss found in 10 patients of 30 HBeAg positive patients with 4 patients occurred as early as at the fourth week. A total of 62 patients HBV DNA converted negatively in antiviral group, but 5 patients were found HBV DNA rebounded (occurred in 24 to 72 weeks) with ALT rebound (47 to 140 U/L).

<b>CONCLUSIONSb>The tendency of spontaneous clearance of HBV DNA when ALT is more than 800 U/L is obvious, so anti-viral therapy should be administrated strictly. The negative conversion rate of HBV DNA has no relation with HBeAg but with the copies of HBV DNA replication.

Adult ; Alanine Transaminase ; metabolism ; Antiviral Agents ; therapeutic use ; DNA, Viral ; blood ; Female ; Hepatitis B virus ; genetics ; Hepatitis B, Chronic ; drug therapy ; enzymology ; Humans ; Male ; Retrospective Studies ; Young Adult

HBV infections leads to severe public health problems around the world, especially in China. Improved understanding of the molecular mechanisms of HBV reverse transcription is fundamental for optimization of treatment and solution to drug-resistance. Recently, the main structural basis involved in the process of HBV reverse transcription and the cis-elements were revealed by means of biochemistry and genetics. The entire process of reverse transcription is completed mainly through the first template switch mediated by the P- epsilon structure; the second template switch mediated by 5E/3E and M structure; and the third template switch mediated by 5' r / 3' r structure. The important structure and the cis-elements involved in this process are the focus of this review, at the same time, an overview of the progress in relevent studies is demonstrated to show the whole picture of the HBV reverse process.
Animals ; Hepatitis B ; virology ; Hepatitis B virus ; enzymology ; genetics ; metabolism ; Humans ; RNA, Viral ; genetics ; RNA-Directed DNA Polymerase ; genetics ; metabolism ; Reverse Transcription ; Viral Proteins ; genetics ; metabolism

<b>OBJECTIVEb>To investigate the intrahepatic expression of inducible nitric oxide synthase (iNOS) in patients with chronic hepatitis B (CHB) and its relation to liver histopathology.

<b>METHODSb>The intensity and distribution of the immunohistochemical staining of intrahepatic iNOS were studied in the liver biopsy specimens obtained from 74 patients with CHB and statistical analyses were performed between intrahepatic iNOS and ALT, HbeAg, HBV DNA grading of liver inflammation and staging of fibrosis. Seven histologically normal liver sections were used as a control group.

<b>RESULTSb>Compared with the control group, the intrahepatic iNOS immunoexpression was significantly higher in patients with CHB (P < 0.05), iNOS immunoreactivity was observed mainly in hepatocytes showing a predominant cytoplasmic staining, with the positive liver cells distributed diffusely throughout the hepatic lobule. Immunopositive staining could also be detected in Kupffer cells, sinusoidal lining cells and vascular endothelial cells. Compared with patients with normal ALT, the hepatocellular iNOS immunoexpression was significantly higher in patients with elevated ALT (P < 0.05) and the iNOS immunoexpression was significantly correlated with the serum level of ALT (r=0.601, P=0.000). Statistical analysis also showed that the intrahepatic iNOS immunoexpression was positively correlated with the grading of liver inflammation and the staging of liver fibrosis (r=0.660, P=0.000; r=0.507, P=0.000). No significant correlation between iNOS and HBeAg and HBV DNA was detected. CONCLUSION The intrahepatic expression of iNOS is elevated in chronic hepatitis B patients and correlated well with the severity of the disease, which indicated that inducible nitric oxide synthase may have a critical role in the pathogenesis of chronic viral hepatitis B.

Adult ; Alanine Transaminase ; metabolism ; DNA, Viral ; metabolism ; Female ; Gene Expression Regulation, Enzymologic ; Hepatitis B Antigens ; metabolism ; Hepatitis B virus ; metabolism ; Hepatitis B, Chronic ; enzymology ; metabolism ; pathology ; virology ; Hepatocytes ; metabolism ; Humans ; Male ; Nitric Oxide Synthase Type II ; metabolism

<b>OBJECTIVEb>To investigate the function of hepatitis B virus polymerase (HBV Pol) in the viral life cycle by screening the proteins interacting with HBV polymerase.

<b>METHODSb>The HBV Pol gene was constructed into the pGBKT7 vector. GAL4 yeast two-hybrid system was used to screen the human liver cDNA library to obtain proteins which interacted with HBV Pol. GST-pull down assay was applied to confirm the protein interactions.

<b>RESULTSb>Ubiquitously expressed transcript (UXT) was selected by the yeast two-hybrid system. GST-pull down assay confirmed the in vitro interaction between HBV Pol and UXT.

<b>CONCLUSIONSb>UXT is a potential interactor of HBV Pol, and this protein interaction may provide clues of the function of HBV Pol in HBV life cycle.

Gene Products, pol ; metabolism ; Hepatitis B virus ; enzymology ; Humans ; Neoplasm Proteins ; metabolism ; Protein Interaction Mapping ; Two-Hybrid System Techniques ; Virus Replication

Clinically being applied treatment against chronic hepatitis has three limitations: low response rates, severe adverse effects and a high rate of drug resistance. Hence, novel targets for antiviral therapy need to be developed so as to provide an armory of different strategies. During the replication of hepatitis B virus, the interaction of viral polymerase (P protein, also called P) and epsilonRNA is indispensable for the initiation of reverse transcription via protein priming and the pregenome RNA (pgRNA) packaging. Three strategies are currently developed for blocking P-epsilon interaction: heat shock protein inhibitors, epsilonaptamers and chemical compounds for blocking formation of P-epsilon complex. Previously, our group has for the first time worldwide in vitro screened several aptamers, which are able to interfere with the P-epsilon interaction. A strong inhibition against HBV was observed in vitro and in vivo experiments, respectively. In conclusion, the so far developed chemicals suppressing the P-epsilon interaction may bypass or overcome the viral resistance problems during clinic treatment and represent a highly attractive option for therapeutic intervention.
Animals ; Gene Expression Regulation, Viral ; Gene Products, pol ; antagonists & inhibitors ; genetics ; metabolism ; Hepatitis B ; therapy ; virology ; Hepatitis B virus ; enzymology ; genetics ; physiology ; Humans ; RNA, Viral ; genetics ; metabolism ; Virus Replication

<b>OBJECTIVEb>To investigate the cleavage activities of 10-23 DNA enzymes targeting at HBV C gene mRNA in vitro.

<b>METHODSb>10-23 DNA enzymes named DrzBC-7, DrzBC-8 and DrzBC-9 specific to HBV C gene ORF A1816UG were designed and synthesized. HBV C gene mRNA was obtained by in vitro transcription method. Cleavage activities were observed in vitro. The influence of MgCl2 concentration on RNA cleaving activity was examined with DrzBC-9. Values of kinetic parameters including Km, Kcat and Kcat/Km were calculated accordingly.

<b>RESULTb>Targeted substrate mRNA with the size of 300 nt was obtained by transcription in vitro. Under the certain cleavage conditions, DrzBC-7, DrzBC-8 and DrzBC-9 all efficiently cleaved target mRNA at specific sites in vitro. Cleavage products of 109 nt and 191 nt were obtained. No cleavage occurred without MgCl2. The most efficient cleavage was obtained at 150 mmol x L(-1) MgCl2. The efficiency of cleavage did not increase when the MgCl2 concentration was more than 200 mmol x L(-1). The kinetic parameters, Km, Kcat and Kcat/Km for DrzBC-9 were 1.4x10(-9) mol x L(-1), 1.6 min(-1) and 1.1x10(9) mol x L(-1) x min(-1), respectively.

<b>CONCLUSIONb>10-23 DNA enzymes targeting at HBV C gene mRNA possess the specific cleavage activities in vitro.

DNA, Catalytic ; metabolism ; DNA, Single-Stranded ; metabolism ; Hepatitis B virus ; enzymology ; genetics ; Open Reading Frames ; RNA, Messenger ; metabolism ; RNA, Viral ; genetics ; metabolism ; Transcription, Genetic

BACKGROUNDS/AIMS: Continuation of lamivudine therapy is controversial for patients with chronic hepatitis B when viral breakthrough occurs. Moreover, the effect of continuous lamivudine therapy is unknown in patients with acute exacerbation after viral breakthrough. We assessed clinical course of acute exacerbation after viral breakthrough in patients who continued and discontinued lamivudine therapy. METHODS: Medical records of 109 patients with viral breakthrough during lamivudine therapy were reviewed. Of 40 patients with acute exacerbation (ALT level > 5 x ULN), adefovir dipivoxil was unavailable in 38 patients. These 38 patients (mean age 42.6 years; male/female, 34/6) were divided into continuation (n=21) and discontinuation (n=17) groups. Clinical courses of the 2 groups were compared. RESULTS: During follow-up period (mean, 27 months; range, 6-60 months), ALT levels decreased to < 2 x ULN in 11 patients (52%) of continuation group and 9 patients (53%) of discontinuation group, varied from 2 x to 5 x ULN in 9 (43%) and 5 (29%), respectively, and increased to > 5 x ULN in 1 (5%) and 3 (18%), respectively, with no statistical significance (P=.417). CONCLUSIONS: When acute exacerbation of ALT levels occurs after viral breakthrough during lamivudine administration in patients with compensated chronic hepatitis B, continuation of lamivudine may have no advantage over discontinuation.
Phosphonic Acids/therapeutic use ; Middle Aged ; Male ; Lamivudine/*administration & dosage ; Humans ; Hepatitis B, Chronic/drug therapy/enzymology/*virology ; Hepatitis B virus/*isolation & purification ; Female ; Antiviral Agents/*administration & dosage ; Alanine Transaminase/blood ; Aged ; Adult ; Adenine/analogs & derivatives/therapeutic use ; Acute Disease