Hepatitis B virus （HBV） exclusively infects liver parenchymal cells and forms covalently closed circular DNA （cccDNA） within their nuclei. HBV cccDNA serves as the essential template for viral gene transcription， the sole source of progeny virus production， and the key driver of viral antigen expression， and it is the molecular basis for the persistence of HBV infection. Therefore， elimination and/or functional silencing of cccDNA is the key to eradicate chronic HBV infection. This article discusses the critical scientific issues that need to be solved during elimination of the harm of HBV infection from the perspectives of the synthesis， transcription， and clearance of cccDNA， as well as the impact of nonparenchymal cells on cccDNA， in order to provide a reference for eradicating HBV infection in the future.

Objective To analyze the drug resistance status of mycobacterium tuberculosis in patients with double immunization of human immunodeficiency virus (HIV) and tuberculosis (TB) by phage bioassay (PhaB),and to optimize the control strategy.Methods One hundred and twelve cases of HIV/TB infected patients.in Chongqing Ninth People's Hospital were treated with PhaB method,and the drug susceptibility testing results were compared with 208 cases of simple pulmonary tuberculosis patients.Results The anti-tuberculosis drug resistance rate of HIV/TB patients was lower than that of simple pulmonary tuberculosis patients.The resistance rates of 5 common anti-tuberculosis drugs in HIV/TB patients were 7.14％ of isoniazid (INH),7.14％ of pyrazinamide (PZA),5.36 ％ of rifampicin(RFP) streptomycin(SM),and 4.46 ％ of ethambutol (EMB),compared with simple pulmonary tuberculosis(resistance rates of RFP were 17.31％,IN H 13.46 ％,PZA 11.54 ％,EMB 10.58 ％,SM 9.62 ％),RFP resistance rate of HIV/TB infected patients was lower(P＜0.05).There was no significant difference between two groups in the other four anti-tuberculosis drug(P＞0.05).The coincidence rate with the absolute concentration method were INH 96.4％,RFP 98.2％,PZA 96.4％,EMB 93.8％ and SM 96.4％,respectively.Conclusion The resistance rate of mycobacterium tuberculosis to RFP in patients with HIV/TB infection in this region is lower than that in patients with common pulmonary tuberculosis,which is related to the good medication compliance of these patients.PhaB has the characteristic of fast,simple,without special equipment,it can be used as a rapid screening of mycobacterium tuberculosis drug resistance method.

A549 Cells ; Animals ; Drug Evaluation, Preclinical ; Drug Resistance, Viral ; drug effects ; Humans ; Influenza A virus ; metabolism ; Mice, Inbred BALB C ; Orthomyxoviridae Infections ; drug therapy ; metabolism ; Sesterterpenes ; chemistry ; pharmacology