The mercury content in soil and sediment, although minimal, but its toxicity is substantial.Different speciation of mercury has different toxicity, so the determination of total mercury can not fully reveal its toxicity and bioavailability.The speciation of mercury has become more and more indispensable.This paper summarizes the extraction and determination methods of the total and the speciation mercury in soil and sediment, and the extraction and determination of methyl mercury.

Objective:To study the immune responses of HBV based immunization co injecting CpG oligodeoxynucleotides in HBV transgenic mice.Methods:The HBV transgenic mice were immunized by multiple sites intramuscular injection with V HBs and CpG ODN or V HBs alone or V 1012 controls.The anti HBs Ab and HBsAg in serum from immunized mice was measured by ELISA.The expression of HBsAg in liver tissue was detected by immunohistochemistry method(SP).The histological activity index was calculated with Knodell's method.Results:The anti HBs Ab in serum could be detected and HBsAg in serum and liver tissues could not be measured in 2 out of 6 HBV transgenic mice immunized with V HBs+CpG ODN.There were not significantly changes in the level of anti HBs Ab and HBsAg in serum from HBV transgenic mice immunized with V HBs or V 1012 alone.The histological activity indexes in liver tissues from mice immunized with V HBs+CpG ODN were higher than that in mice inoculated with V HBs or V 1012 alone.The large number of lymphocytes could be found in liver tissues in V HBs+CpG ODN immunization group by microscopy.Conclusion:The immuno response,which seems to be responsible for the disappearance of HBsAg,might be elicited in HBV transgenic mice immunize with V HBs+CpG ODN.

BACKGROUNDTo explore the possibility of using retrovirus vector to carry HBV vector, and to prove that replication defective HBV could be normally packaged.

METHODSTwo kinds of full length of mutant HBV gene, which express dominant negative mutants, were inserted into retrovirus vector. After recombinant retroviruses were harvested, they were used to infect Hep G2 and 2.2.15 cell line. Then the expression of HBV core antigen in the Hep G2 cell was examined by immune fluorescence, and the existence of recombinant HB virion in the culture medium was examined by PCR.

RESULTSHigh titer of recombinant retroviruses were obtained in the culture medium of transfected PA317 cell line. Core antigen was detectable in the recombinant retrovirus infected Hep G2 cell. Recombinant HB virion was detectable in the culture medium of recombinant retrovirus infected 2.2.15 cell.

CONCLUSIONSThe results suggested that recombinant retrovirus could carry HBV vector and express HBV products. When structural protein is offered by wt-HBV, the recombinant retrovirus may function as HBV vector, therefore it could be used in anti?HBV gene therapy.

Genetic Therapy ; Genetic Vectors ; Hepatitis B Core Antigens ; biosynthesis ; Hepatitis B virus ; genetics ; Humans ; Recombination, Genetic ; Retroviridae ; genetics ; Tumor Cells, Cultured ; Virus Replication