Objective To investigate the different biochemical testing system inter laboratory comparability of results,provide reference for promoting inter laboratory test results of the recognition.Methods Five patients with laboratory detection of fresh mixed serum,20 consecutive determination of 10 biochemical items,precision analysis.According to America clinical and Laboratory Standards Institute (CLSI)Document EP9-A2,the Panzhihua Iron and Steel Group General Hospital detec-tion system as the reference system,the remaining four hospital detection system as the detection system,with a fresh mixed serum,determination of five biochemical items (Urea,Cr),(AST,ALT),(TP,ALB),(TG,TC)and (HDL-C,LDL-C),the determination results were compared and analyzed,calculated reference system and the correlation coefficient,linear regres-sion equation between the system and the various medical decision level relative deviation (SE%),and to America Clinical Laboratory Improvement Amendment ability test (CLIA’88)allowed total error of 1/2 as the standard,to the assessment system and the reference system between the comparability and clinical acceptability.Results In Urea,Cr determination for example,CV of five laboratories on Urea and Cr two project was less than CLIA’88 allowed total error of 1/3,the precision could meet the clinical requirements.The detection results significantly correlated (r2 >0.975).The evaluation of clinical ac-ceptability,in Urea low at medical decision level,there were two laboratory determination results that could not be accepted for clinical.In Urea high at medical decision level,there was a laboratory measurement result that could not be accepted for clinical.In the low Cr at medical decision level,there were two laboratory determination results that could not be accepted for clinical.The rest of the system Urea,Cr projects in various medical decision level compared with the system,the SE% was less than CLIA’88 allowed total error of 1/2,for clinical acceptable.Conclusion Laboratory determination results between different biochemical testing system had bias in different degrees,bias part of the project exceeds the allowed error range.

Objective To investigate the effect of kaempferol(KAE)on the function of drug-resistant Bel-7402/5-Fu cells.Methods Bel-7402/5-Fu cells were treated with KAE,and cells were divided into the control group and the drug group(0.064,0.320,1.600,8,40,200 μmol/L KAE).Cells were divided into the si-NC group and the DNA-PKcs interference group,or the control group,the KAE group,the KAE+si-DNA-PKcs group or the KAE+DMSO group,the KAE+MG132 group and the KAE+CQ group based on interfering DNA dependent kinase catalytic subunits(DNA-PKcs)or addition of proteasome inhibitor MG132 or autophagy inhibitor CQ.Cell proliferation was detected using CCK-8.The expression level of histone H2AX phosphorylation(γ-H2AX),DNA-PKcs,DNA double strand break repair/V(D)J recombinant protein(Artemis)and drug pump gene(P-gp)were analyzed using real-time fluorescence quantitative PCR(RT-qPCR)and Western blot assay.Cell cycle and apoptosis were detected by flow cytometry.The stability of DNA-PKcs proteins was analyzed by protein stability experiments.Ubiquitination of DNA-PKcs protein was evaluated by immunoprecipitation assay.Results Compared to the control group,treating cells with 8 μmol/L KAE for 24 h inhibited about 50%of cell proliferation ability.Therefore,this time and concentration were chosen for subsequent research.Compared to the control group,the expression level of γ-H2AX mRNA and protein significantly increased,while expression levels of DNA-PKcs,Artemis and P-gp mRNA and proteins significantly decreased in the KAE group(P＜0.05).Compared to the control group,KAE promoted cell cycle arrest in the G2/M phase of Bel-7402/5-Fu cells and increased cell apoptosis.Compared to the si-NC group,siRNA-1664 significantly downregulated the mRNA and protein expression levels of DNA-PKcs(P＜0.05).Compared with the KAE group,the effect of KAE was further promoted in the KAE+si-DNA-PKcs group of Bel-7402/5-Fu cells.Compared with the control group,the protein expression level of DNA-PKcs decreased in the KAE+DMSO group(P＜0.05).Compared with the KAE+DMSO group,the protein expression level of DNA-PKcs increased in the KAE+MG132 group(P＜0.05),while there was no significant change in the protein expression level of DNA-PKcs in the KAE+CQ group(P＞0.05).Compared to the control group,there was promoted ubiquitination of DNA-PKcs in the KAE+DMSO group,and the inhibited ubiquitination in the KAE+MG132 group(P＜0.05).Conclusion KAE may induce cell apoptosis and cell cycle arrest in drug-resistant Bel-7402/5-Fu cells.