Evaluation of the effects of calibration modes and sample reconstitution on the analytic precision of 26 clinical chemistry analytes using system measurement procedure / 中华检验医学杂志

Objective To evaluate the system measurement procedure effects on the analytic precision of clinical chemistry analytes.Methods In June 2009, June 2010 and September 2010 respectively,the National Center for Clinical Laboratories of China and the Organization of Five Hospitals in Fukuoka Japan organized comparison activities of 26 clinical chemistry analytes which were ALT,AST,GGT, ALP,CK,LDH,AMY,ChE,TG,TC,HDL-C,LDL-C,Glu,Cr,BUN,UA,K,Na,Cl,Ca,TP,Alb,TBil,DBil, P,Fe.In this paper, we investigated 26 analytes of three sets in Beijing Aerospace General Hospital as follows.(1)The precision of different reconstitution methods was observed by using three kinds of pipetting tools, such as measuring pipette, pipette and dispenser.(2)The experiments were carried out in three stages by testing the dried powder control samples of two concentration levels(101-Ⅰ,101-Ⅱ)provided by Hitachi Japan.They were measured on 28 consecutive days at each stage in order to observe the precision of 26 clinical chemistry analytes.In the first stage,we used the former measurement procedure to measure the control samples;in the second stage we added three conditions of the measurement procedure.The first was two calibration modes,which were once-a--day calibration and twice-a--day calibration.The second was the calibration standard and the last was the conditions of the freeze-thaw samples.In the third stage, we used the twice-a-day calibration only for GGT,ALP,ChE,TG,Cr,Na,K,CL,ALB.(3)JSCC and Health Industry Standard quality objectives were implemented to evaluate whether the precision of the improved measurement procedure met the requirements.(4)Paired T test were used to compare the precision of measurement between the second stage and the first stage, and between the third stage and the second stage of the measurement procedure.Results (1)The precision of three kinds of pipetting tools were 0.56%,0.10%, 0.01%.(2)The ranges of precision of ALT,AST,GGT,ALP,CK,LDH,AMY,ChE,TG,TC,HDL-C,LDL-C,Glu,Cr,BUN,UA,K,Na,Cl,Ca,TP,Alb,TBil,DBil,P,Fe were 0.99%-10.5% about 101-Ⅰ and 0.91%-7.03%about 101-Ⅱin the first stage.The ranges of precision were 0.66%-8.81%of 101-Ⅰand 0.66%-4.28%of 101-Ⅱin the second stage.The ranges of precisions were 0.60%-3.91%of 101-Ⅰand 0.73%-3.39%of 101-Ⅱin the third stage.(3)73%/80%of the samples met the standard of JSCC about 101-Ⅰand 101-Ⅱand 80%/88%of the samples met the standard of Health Industry Standard in the first stage.88%/100% of the samples met the standard of JSCC about 101-Ⅰand 101-Ⅱ and 100%/100%samples met the standard of Health Industry Standard in the second stage.The ratio of samples meeting the standard of JSCC about 101-Ⅰand 101-Ⅱwere 96%/100% and that of Health Industry Standard were 100%/100%in the third stage.(4)Precision of 101-Ⅰand 101-Ⅱwas statistically significant between the measurement procedures of second stage and the first stage,and there was no significant difference between the third stage and the second stage.Conclusion (1)The precision of samples using dispenser to reconstitute is higher than that of the other two pipetting methods.(2)Improving the calibration mode and reconstitution of samples increase the precision of 26 clinical chemistry analytes by over 50%.

Investigations on the effect of measuring value transfer for human serum samples assigned by the reference laboratory network / 临床检验杂志

Objective To investigate the effect of measuring value transfer for human serum samples assigned by the reference laboratory network on improving the trueness of seven enzyme activities in clinical laboratories,such as ALT,AST,GGT,LDH,CK,AMY and ALP.Methods Depending on the medical imtitutions at all levels contacted by 5 reference laboratories in North China,South China,East China and Southwest China,the corresponding clinical laboratory measuring value transfer/traceability network was established.The frozen human serum samples with good interehangeability and standard material characteristics,including calibrator,sample 1 and sample 2,were provided by Beijing Aerospace General Hospital,and were assigned by 5 reference labotatories in four regiom.These samples were sent to 48 clinical laboratories.These clinical laboratories measured sample 1 and sample 2 according to their standard operating procedures,and then measured.the two samples again after adjusting their measurement system by using the supplied calibrator.The changes of trueness of detection results in these laboratories were evaluated according to the WS/T 403-2012 standard,and the changes of consistency for ALT and AST before and after measuring value tramfer were investigated.Results The results of AMY,ALP,GGT,CK and LDH calibrator,sample 1 and sample 2 assigned by the established network were 138.7 U/L,278.5 U/L and 68.3 U/L,265.3 U/L,94.5 U/L and 134.4 U/L,195.8 U/L,89.0 U/L and 158.9 U/L,393.7 U/L,260.0 U/L and 645.3 U/L,and 302.0 U/L,250.0 U/L and 452.7 U/L,respectively.The percentages of sample 1 and sample 2 which met the bias requirements of the WS/T 403-2012 standard before measuring value transfer for AMY,ALP and GGT were 65.9％ and 61.0％,76.6％ and 78.7％,and 66.7％ and 70.8％,respectively,while after measuring value transfer,they were 89.2％ and 83.8％,86.7％ and 80.0％,and 85.4％ and 91.7％,respectively.The percentages of sample 2 which met the bias requirements of the WS/T 403-2012 standard before measuring value transfer for CK and LDH were 64.6％ and 58.3％,respectively,while after measuring value trander,they were 93.5％ and 84.8％,respectively.The coefficients of variation (consistency) of sample 1 and sample 2 for ALT and AST before measuring value tramfer were 12.9％ and 11.3％,and 10.2％ and 8.9％,respectively,while after measuring value transfer,they were 9.3％ and 8.2％,and 5.6％ and 5.9％,respectively.Conclusion The calibration of routine measurement systems based on the measuring value transfer for human serum samples assigned by the reference laboratory network may improve the comparability of 7 enzyme actvities measurement results in chnical laboratories at all levels obviously,which deserves to be further spread.

MicroRNA-21 for regulation of TLR4 in Hela cells / 中国组织工程研究

BACKGROUND:MicroRNAs (miRNA) through regulating specific target gene mRNA expression play important roles in different processes of diseases. OBJECTIVE:To study the interaction of miRNA-21 with its target gene TLR4 in Hela cels. METHODS:The candidate target gene of miRNA-21 was determined according to miRNA analysis databases. The constructed recombinant adenovirus vector carrying pri-miRNA-21 gene was used, which could package and amplify viruses to transfect Hela cels. Then, the expression of fluorescent proteins was detected. Forty-eight hours after transfection of miRNA-21 or control, extracted proteins were used for detection of TLR4 protein using western blot assay. RESULTS AND CONCLUSION:Recombinant adenoviruses pAd/pri-miRNA-21 and pAd/neg at 100 MOI could successfuly infect Hela cels. Bioinformatic analysis suggested several possible binding sites between miRNA-21 and TLR4. The experimental results showed that miRNA-21 down-regulated TLR4 at protein levels, indicating that miRNA-21 can interfere with the expression of TLR4 target gene.

Study on the quantity value transfer of enzymes from the reference measurement system / 中华检验医学杂志

Objective Using the frozen human-pooled serum samples,with values assigned by the enzyme reference procedure in laboratory network to explore the way of quantity value transfer from enzyme reference measurement system to routine ones.Methods The study is about quantity value transfer.The frozen human-pooled serum sample was assigned by the enzyme reference laboratory network including six domestic reference procedure laboratories,namely Beijing Chaoyang Hospital affiliate of Capital University of Medical Sciences,Beijing Aerospace general Hospital,Beijing Shijitan Hospital affiliate of Capital University of Medical Sciences,Peking Union Medical College Hospital,Beijing Leadman Biochemistry Co.,Ltd.and Sichuan Maker Biotechnology Co.,Ltd.,which used the reference measurement procedures of creatine kinase (CK) and lactate dehydrogenase (LDH) from the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC).First,the assigned serum was used to calibrate or verify trueness of routine measurement systems from the 49 laboratories of tertiary hospitals in Beijing in Feb,2013 by Beijing Centerfor Clinical Laboratories.Second,the assigned serum and two levels of patient samples were tested in duplicate by laboratory 's measurement systems after calibration with manufacturer's calibrator and with assigned serum.During this procedure,all laboratories data were collected.Harmonization of results was observed after calibration with the assigned serum according to the statistics.Results After calibration,the interlaboratory coefficients of variation (CVs) of two patient samples were decreased from 4.67％ and 5.96％ to 1.86％ and 1.47％ for CK and from 5.72％ and 5.04％ to 3.67％ and 3.62％ for LDH.For peer group of A and B instrument,after calibration,both CVs of the assigned serum and two patient samples were less than 2％ for CK,and less than 4％ for LDH ; For C instrument group,which was not calibrated with the assigned serum,the biases were-4.75％ for CK and-13.1％ for LDH,while the biggest CVs were 3.64％ for CK and 7.57％ for LDH.For peer group of reagents,after calibration,the CVs were decreased from 1.60％-4.44％ to 0.23％-1.62％ for CK and from 0.93％-6.07％ to 1.06％-2.72％ for LDH.Conclusions It is one of the feasible ways for quantity value transfer by using the frozen human-pooled serum samples,which were assigned by the enzyme reference laboratory network for calibration or verification.It can effectively solve the problem of trueness and harmonization of enzyme testing results.In addition,for those measurement systems which are not applicable for this calibration.

The evaluation of trueness of 4 α-amylase measurement systems / 中华检验医学杂志

Objective To investigate the routine methods of α-amylase (AMY) test in scrum which meets the requirements of ISO 15189.Methods Fifty human serum samples with different concentrations of AMY (40- 750 U/L) were collected from March to December in 2008,to form the patients' frozen serum group.Four AMY measurement systems including Roche,Wako,MINDRAY and MAKER were used.The frozen standard materials with concentrations of ( 70.1 ± 3.7 ) U/L and ( 418.3 ± 22.1 ) U/L and the patients' frozen serum group were measured simultaneously by using IFCC reference method and 4 AMY measurement systcms based on 7170A automatic biochemistry analyzer.Thc linear regression analysis was made between the measurement results of each system and IFCC reference method.The equivalence,agreement and trueness were also evaluated by using the file EP9-A2 method.Bland-Altman GraphicalAnalysis and the improved Bland-Altman Graphical-Analysis of MVS1.80 software.Results Judging by the standards of IFCC reference method,the measurement results of 4 measurement systems were obviously different. ( 1 ) When measuring standard materials the results were 66.4,70.6,69.4 and 49.2 U/L respectively and 394.0,456.4,406.7,302.4 U/L respectively.The measurement results of MINDRAY were in agreement with that of IFCC reference method.( 2 ) When mcasuring the patients' scrum group by 4 measurement systems and IFCC reference method,the slopes of the linear regression equations were 0.934,1.070,0.930 and 0.731.respectively.And the intercepts were 0.886,6.249,5.388 and 3.574,respectively.According to the EP9-A2 method,the measurement results of Roche Wako,MINDRAY were equivalent to that of IFCC reference method.According to Bland-Altman Graphical-Analysis, the measurement results of Roche and MINDRAY were in agreement with that of IFCC reference method.The average biases of each measurement system were - 6.11％ ( Average bias ± 2s were 2.81％ and -9.40％ ),1.99％ ( Average bias ± 2s were 10.35％ and - 6.36％ ),- 2.70％ (Average bias ± 2s were 2.37％ and -7.77％ ) and -34.72％ ( Average hias ±2s were -24.20％ and -45.24％ ),respectively.According to the improved Bland-Altman Graphical-Analysis, the measurement results of MINDRAY are correct.The average biases of each measurement system were - 5.92％ (Average bias ± 2s were -2.81％ and -9.03％),2.10％ (Average bias ±2s were 10.74％ and -6.53％),-2.64％ ( Average bias ± 2s were2.24％ and -7.51％ ) and - 29.51％ ( Average bias ± 2s were 21.82％ and - 37.21％ ),respectively.Conclusions ( 1 ) The measurement results of different measurement systems do not necessarily have crreet results though they have claimed to have traceability.(2) The trueness of measurement results using the same system may not come to the same conclusion when evaluated by different methods.So laboratories should select and establish a procedure to evaluate trueness of routine methods and adopt those meeting the trueness requirements of ISO 15189.

Performance of IFCC enzyme reference method laboratory network in China / 中华检验医学杂志

Objective To review the performance of the IFCC enzyme reference methods in China laboratories and to evaluate the competence of enzyme reference measurement in China.Methods The Intemational Federation of Clinical Chemistry and Laboratory Medicine(IFCC)enzyme reference methods were performed in 8 China laboratories.Reference procedures were developed by each laboratory and the performances were evaluated.The Clinical and Laboratory Stadards Institute(CLSI)EP-5 protocol was used for the evaluation of precision and certified reference materials(CRMS)were used for the verification of trueness.Seven of the 8 laboratories participated in the 2006 IFCC external quality assessment program for reference laboratories(RELA)for the assessment of the measurement performance.Results Within-run CVs of less than 1.5%and between-run CVs of less than 2%were achieved bv all the China laboratories.Results on CRMs by some of the laboratories agreed with the certified value within the stated uncertainty.In the 2006 RELA,the averages and the interlaboratory CVs of the China laboratories were similar to those of international laboratories.Conclusion A preliminary enzyme reference method laboratory network has been established in China.