Objective To use the syphilis helicoid gelatin aggregation experiment (TPPA ) method to compare the results of syphilis serological detection reagents between the ELISA method and the colloidal gold method for evaluating the clinical applica ‐bility of each detection reagent .Methods 6 291 serum samples were selected from the hospitalized patients before surgery or before blood transfusion ,and performed the preliminary screening detection by the ELISA method (reagent A and B) and the colloidal gold method ,the positive or weakly positive specimens in preliminary screening were performed the confirmation test by the TPPA method .Results In 6 291 serum specimens ,the positive cases of the reagent A ,reagent B and colloidal gold method were 66 ,64 and 56 cases respectively ,the positive detection rate of colloidal gold method had no obvious difference between the reagent A and rea ‐gent B (P> 0 .05) .The positive samples were confirmed to be 66 cases by TPPA ,including 61 cases of reagent A and reagent B positive ,and the colloidal gold method had 56 cases .5 cases of reagent A positive and 3 cases of reagent B positive were confirmed to be 3 and 2 cases by TPPA respectively ,the sensitivity of the colloidal gold method had significant difference between the reagent A and reagent B(P< 0 .05) .Conclusion ELISA method has high sensitivity and is easy to realize the automated enzyme‐linked im‐munoassay ,which is suitable for the screening of the patient sample before surgery or before blood transfusion .The colloidal gold method has low sensitivity ,but high specificity ,is simple and convenient which is suitable for large‐scale healthy physical examina‐tion and preliminary screening test before emergency surgery .In order to avoid medical disputes ,the positive samples by the ELISA method and colloidal gold method should be confirmed by the TPPA method .

Objective:To observe whether nitric oxide (NO) could enhance the damaging effect of cyclophosphamide on L1210 cells cultured in vitro, and to investigate the mechanism of this action. Methods:L1210 cells were co-cultured with 3T3 cells in DMEM medium supplemented with cyclophosphamide (400 ?g/ml). The L1210 cells were divided into three groups based on different transfected 3T3 cells: pcDNA3.0-iNOS plasmid transfected 3T3 cells (Group 1), pcDNA3.0 plasmid transfected 3T3 cells (Group 2), pcDNA3.0-iNOS plasmid transfected 3T3 cells plus DEVD-CHO(Group 3). The viability and apoptosis rate of L1210 cells at different culture periods were determined by trypan blue exclusion and TUNNEL method, respectively. And the cell cycles at G_1 and S phase were detected by flow cytometry. Results:①After cyclophosphamide treatment, the viability of L1210 cells was significantly lower in Group 1 than that in Group 2 during 12-72 h (P