Development of national secondary reference materials of urea and creatinine in frozen human serum / 中华检验医学杂志

Objective:To develop a national secondary reference material of Urea and Creatinine in frozen human serum as a standard for metrological traceability.Methods:According to JJF1343-2012 "General and Statistical Principles for Characterization of Reference Materials" and JJF 1006-1994 " Technical Norm of Primary Reference Material ", the homogeneity, stability, and commutability were evaluated;Using the JCTLM recommended methods, the value of the reference materials was assigned through collaboration with 6 accredited reference laboratories from Guangdong Provincial Hospital of Chinese Medicine, Beijing Aerospace General Hospital, Shenzhen Mindray Bio-Medical Electronics, Maccura Biotechnology, Beijing Leadman Biochemistry, and Zhejiang MedicalSystem Biotechnology. Uncertainty components including inhomogeneity, stability and value assignment were evaluated.Results:The results of one-way analysis of variance of homogeneity for the reference materials showed P>0.05, and the stability evaluation was less than the critical value of the t-test. The measured values were in the 95% confidence interval in the four conventional detection systems for commutability, and the certified values and expanded uncertainties were urea:(14.7±0.3) mmol/L ( k=2),Cr:(313.9±14.5) μmol/L ( k=2). Conclusion:The prepared secondary reference materials of urea and creatinine had promising homogeneity, stability, and commutable, the values of urea and creatinine concentration in reference materials were accurate and reliable.

Performance evaluation of serum progesterone measurement by ID-LC/MS/MS candidate reference methods and their clinical application value / 中华检验医学杂志

Objective:To establish a candidate reference method for serum progesterone using isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) in our laboratory, validate the analytic performance of five clinical routine detection systems to explore the comparability of serum progesterone detection by different detection systems.Methods:A candidate reference method for serum progesterone using ID-LC/MS/MS method was established. The sample was pretreated by liquid-liquid extraction method, and the reversed phase liquid phase separation in positive ion mass spectrometry mode was used to detect progesterone in human serum, and the detection time of a single sample was controlled within 5 minutes by gradient elution. In order to improve the accuracy of the method, the bracketing calibration method (BCM) was used to establish the standard curve. The sensitivity, accuracy, precision and specificity of BCM and classical calibration curve method were evaluated according to CLSI C62-A, EP15-A2, EP6-A2 and EP9-A3, and the analytical performance and comparability of five clinical routine progesterone detection systems were evaluated,compared with ID-LC/MS/MS method, the bias at medical decision level 2 and 25 ng/ml was evaluated to see if they were <1/2TEa (12.5%).Results:The limit of detection (LOD) of ID-LC/MS/MS was 0.005 ng/ml. The recoveries of BCM method and classical calibration curve method are 97.95%-101.58% and 96.88%-110.70%, respectively. The measurement results of BCM method for certified reference materials are within its declared uncertainty range. The intra-and inter-assay coefficient of variation ( CV) of BCM method was less than 3.0%, which was better than that of classical calibration curve method ( CV: 2.48%-9.33%). The precision and linear range of the five clinical routine detection systems can meet the detection requirements. The measurement bias of detection system 1, 3 and 5 at 25 ng/ml of medical decision level was less than 1/2TEa, and the measurement bias at 2 ng/ml of medical decision level was more than 1/2TEa. The measurement bias of detection system 2 and 4 at two medical decision levels was less than 1/2TEa. Conclusion:The candidate reference method for serum progesterone ID-LC/MS/MS established in our laboratory meets the requirements of the reference method. BCM has better detection performance than classical calibration curve method. The precision and linearity of the five progesterone clinical detection systems are satisfactory. The five clinical detection systems could meet the clinical requirements at the medical determination level of 25 ng/ml, however, only two of the five clinical detection systems meet the clinical requirements at the medical determination level of 2 ng/ml.

Current status on the laboratory determination of advanced glycation end products / 中华检验医学杂志

The concentration and accumulation rate of advanced glycation end products (AGEs) in the body are highly correlated with glycometabolic disorders. Therefore, the clinical detection of AGEs is of great value for the early diagnosis and prognostic evaluation of these diseases. However, due to the complexity of its structure, the diversity of glycosylation sites, and the limitations of existing detection methods, there is still a lack of widely available detection methods in clinical practice. Starting from the structure and classification of AGEs and the value of clinical testing, this article summarizes current status of various laboratory detection methods of AGEs, and the deficiencies and challenges of these testing methods, future directions are further prospected.

Clinical promotion and application of liquid chromatography-tandem mass spectrometry face challenges / 中华检验医学杂志

Liquid chromatography tandem mass spectrometry (LC-MS/MS) is rapidly applied and developed in the field of laboratory medicine. High resolution mass spectrometry promotes efficient screening of biomarkers. Triple quadrupole mass spectrometry helps verify the diagnosis of disease and monitoring efficacy of biomarkers. Its application runs through different fields and links from omics research to experimental diagnosis, and has gradually become an indispensable technical means of disease research and diagnosis. At present, most LC-MS platforms are in the stage of medical research, and there are still some challenges in clinical promotion and application.

Moving Rate of Positive Patient Results as a Quality Control Tool for High-Sensitivity Cardiac Troponin T Assays

Background@#A small shift in high-sensitivity cardiac troponin T (hs-cTnT) assays can lead to different result interpretation and consequent patient management. We explored whether a small bias could be detected using conventional internal quality control (QC) procedures, evaluated the performance of moving average (MA)-based QC procedures, and proposed a new QC procedure based on the moving rate (MR) of positive patient results of hs-cTnT assays. @*Methods@#The ability of conventional QC to detect a 5 ng/L bias was examined using the 1 3s/ 22s/R4s multi-rule procedure as deviation rules.We developed MA and MR procedures for the hs-cTnT assay using eight months of patient data. The performance of different MA or MR procedures was investigated by calculating the median number of patient samples affected until a bias introduced into the dataset was detected (MNPed). After comparing the MNPed across different procedures, we selected an optimal MA or MR procedure for validation. Validation graphs were plotted using the minimum, median, and maximum number of results affected until bias detection. @*Results@#Our conventional QC procedures could not detect a positive bias of 5 ng/L. When a positive bias was introduced, MNPed was much higher using MA than using MR, with cut-off values of 5 ng/L and 14 ng/L, respectively. MR validation charts for optimal procedures provided insight into the MR performance. @*Conclusions@#The MR procedure could detect different errors with few false alarms. In the hs-cTnT assay, the MR procedure with a smaller cut-off value outperformed MA and conventional QC procedures for small bias detection.

Exploration and practice of new online teaching model of clinical microbiology laboratory technology theory course / 中华医学教育探索杂志

We have adopted various smart tools and applied multiple teaching models to smoothly carry out our on-line teaching. Aiming at encouraging students' self-learning and independent thinking, the first task is to cultivate students' self-learning ability and independent thinking way of clinical microbiology. Our online teaching model is based on the asynchronous small private online course (SPOC) of the Chinese University MOOC, the core part of our teaching model, and supplemented by the Sojump questionnaire test and WeChat, the inter-action channels among teachers and students. All of these build up an integrated teaching system which fully embodies the "student-oriented" teaching concept and pushes forward the promotion and application of online teaching in college specialized courses.

Current clinical situation and challenge for liquid chromatography-tandem mass spectrometry in quantitative detection / 中华检验医学杂志

The performance of high sensitivity, specificity and throughput makes liquid chromatography-tandem mass spectrometry (LC-MS/MS) quickly developed and well applicated in clinical laboratories, such as quantitative detection of steroids, vitamins and metabolic small molecules, monitoring drug concertrations as well as the establishing reference methods or verifying reference materials. However, there were still some challenges for the widespread clinical application of LC-MS/MS.

Current status, challenges and apportunities in cardiovascular aging mechanism and detection / 中华检验医学杂志

Age is the main risk factor for cardiovascular disease. This paper mainly discusses the mechanism of cardiovascular aging, status of detection, opportunities and challenges of research, in order to provide theoretical basis and guidance for the prevention and detection of cardiovascular aging.

Current situation of serum protein tumor biomarkers standardization / 中华检验医学杂志

There are many types of serum tumor markers,and their structures and functions vary.The standardization and harmonization of serum tumor markers will contribute to clinical diagnosis and treatment.Therefore,many scholars are committed to the research of their standardization.However,there are only a few items have been standardized.Due to the complexity of determination,most tumor markers are still facing problems and challenges in the process of achieving standardization.

LC-MS/MS-based screening of new protein biomarkers for cervical precancerous lesions and cervical cancer / 南方医科大学学报

OBJECTIVE@#To screen potential plasma protein biomarkers for the progression of cervical precancerous lesions into cervical carcinoma and analyze their functions.@*METHODS@#Plasma samples obtained from healthy control subjects, patients with low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), cervical cancer (CC), and patients with CC after treatment were enriched for low-abundance proteins for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The MS data of the samples were analyzed using Discoverer 2.2 software, and the differential proteins (peptide coverage ≥20%, unique peptides≥2) were screened by comparison of LSIL, HSIL and CC groups against the control group followed by verification using target proteomics technology. Protein function enrichment and coexpression analyses were carried out to explore the role of the differentially expressed proteins as potential biomarkers and their pathological mechanisms.@*RESULTS@#Compared with the control group, both LSIL group and HSIL group showed 9 differential proteins; 5 differentially expressed proteins were identified in CC group. The proteins ORM2 and HPR showed obvious differential expressions in LSIL and HSIL groups compared with the control group, and could serve as potential biomarkers for the progression of cervical carcinoma. The expression of F9 increased consistently with the lesion progression from LSIL to HSIL and CC, suggesting its value as a potential biomarker for the progression of cervical cancer. CFI and AFM protein levels were obviously decreased in treated patients with CC compared with the patients before treatment, indicating their predictive value for the therapeutic efficacy. Protein function enrichment analysis showed that all these differentially expressed proteins were associated with the complement system and the coagulation cascades pathway.@*CONCLUSIONS@#We identified 5 new protein biomarkers (F9, CFI, AFM, HPR, and ORM2) for cervical precancerous lesions and for prognostic evaluation of CC, and combined detection of these biomarkers may help in the evaluation of the development and progression of CC and also in improving the diagnostic sensitivity and specificity of cervical lesions.

A study to construct three prokaryotic expression vectors and its expression in adenosine deaminase / 国际检验医学杂志

Objective To express adenosine deaminase protein by molecular cloning technique.MethodsTotal RNA was extracted from human leukocytes and the cDNA was obtained by reverse transcription.Whereupon the cDNA was used as a template to amplify adenosine deaminase gene by polymerase chain reaction (PCR) and then integrated it into three prokaryotic plasmids pET-28 b, pET-32 a (+) and pHSIE.The plasmid with the correct sequencing was transformed into E.coli BL21 (DE3) by CaCl2 method for the protein expression.The expression activity of these fusion proteins were detected by Western-blot and SDS-PAGE, with the optimized expression conditions.Results Complete fusion of target gene and three prokaryotic plasmids was observed through sequencing.The expressed and accurate ADA protein was identified by Westernblot and SDS-PAGE.The optimal expression conditions were observed:the protein expression would be induced with 0.4 mmol/L IPTG and incubated at 16℃for 24 hours.Conclusion The prokaryotic vectors of adenosine deaminase (BL21+pET-28 b+ADA, BL21+pET-32 a+ADA, BL21+pHSIE+ADA) were successfully constructed and efficiently expressed.

Current situation of renal function test standardization / 中华检验医学杂志

Renal function test items mainly include creatinine, urea, uric acid, cystatin C, urine-alb, urine protein, α1-microglobulin, β2-macroglobulin and retinol binding protein, etc.The standardization and harmonization of these renal function test items will contribute to clinical diagnosis and treatment.Therefore, many scholars are committed to the standardization of renal function tests and part of these testshave been standardized.But some test items, due to the complexity of the determination, the process of achieving standardization are still facing some problems and challenges.

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.

Quality assurance of clinical biochemistry testing:a mualti-center study based reference interval for clinical chemistry tests in the Chinese population / 中华检验医学杂志

Objective To verify and monitor the performance of accuracy, precision and comparability of 26 clinical biochemical analytes (29 methods) in the six centers involved in multi-centers reference intervals research, and to ensure the reliability of theirmeasurement results.Methods During the period of the systems evaluating, two levels of commercial quality control materials and fresh frozen human serum reference materials were applied to verify the performance of inter-laboratory precision and accuracy of analysis systems. During the period of samples testing, the commercial quality control materials were measured whenever samples were analysed, the fresh frozen serum reference materials were measured once a month.The coefficient of variations (CVs), bias and total errors were calculated to assess the precision, accuracy and comparability.Results Verification of precision and accuracy: ( 1 ) the ranges of CVs of 29 methods in the six laboratory laboratories were 0.4%-6.0%, the CVs of all 29 methods met the criterion . (2) The overall average bias of the analysis systems of 21 analytes (24 methods) ranged from -5.15%( ALT) to 4.46% ( Ur ) .Among 24 methods the overall average bias of TP, Glu-GOD, Ur, Cl, Ca exceeded the acceptable range.The quality assessment during the period of samples testing:(1) The overall average bias ranged from -1.95%(Ca) to 2.92%(Ur), median 1.26%, they all met the requirements of relevant standards.( 2 ) When commercial control materials were tested, the requirements of CVs were fulfilled for most methods in the six laboratories,and the CVs of TP, Alb, Cl, Ca exceeded the acceptable range.The overall average TE of all methods met the quality specification for the C-N controls material.For the C-P control material, only the overall average TE of TP (5.05%) exceeded thearceptable range while the other methods met the requirement in criterion.Conclusions The performance of precision and accuracy of the analysis systems used in the six laboratories passed the verification.During the period of sample testing, the performance of precision and accuracy of the most methods in the 6 laboratories met the requirements of quality specifications, and the overall performance was good.Because of the limitation of current technology the performance of some methods didn't fulfill the requirement of specifications, and need to be improved.

Results analysis of serum alanine transaminase measurement in 23 clinical laboratories with target value assigned by reference method / 中华检验医学杂志

Objective To explore the feasibility of inter-laboratory comparison and trueness evaluation among clinical laboratories, and assess the quality of participants′measurement, by measuring the activity of alanine aminotransferase ( ALT ) in patient serum samples.Methods Method comparison study was used.Five patients serum samples, whose target values were assigned by two international candidate reference laboratory with reference method of ALT without pyridoxal phosphate, were measured by 23 routine laboratories.The bias between measurement result of each participant and the mean of reference laboratories was calculated, and then compared to allowable bias 6%.Calculate the mean value and the relative bias.Results Compared with the mean of reference laboratories, the maximum absolute value of bias among the 23 routine laboratories was 31.27%.The rate range which bias was less than the allowable bias was 26.09%-73.91 %.The bias acceptability of 8 participants were more than or equal to 80%;15 participants were less than or equal to 60%; and 3 participants were 0%.Conclusions Using patient serum samples and values assigned by reference method is an effective way to carry out inter-laboratory comparison and trueness evaluation.It can reflect the quality of measurement more truly.

Construction and expression of recombinant plasmids pET32a-AKT1 / 国际检验医学杂志

Objective To construct the recombinant plasmid pET32a-AKT1 and express human AKT1 protein using prokaryotic expression system .Methods Reverse transcriptase-polymerase chain reaction(RT-PCR) was employed to amplify the gene AKT1 in coding region and integrated it with pET 32a plasmid ,following by transforming it into Escherichia coli DH5α and prokaryotic strains BL21(DE3) .Isopropyl-beta-D-thiogalactopyranoside(IPTG) was adopted to induce its expression .Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE ) and Western-blot were used for protein identification .Results Complete fusion of target gene and plasmid was observed .The recombinant plasmid pET32a-AKT1 was successfully transferred into the strain DE3 . After IPTG induction ,protein with relative molecular mass 70 000 was expressed by DE3 .Conclusion The recombinant plasmid pET32a-AKT1 is constructed successfully and AKT 1 protein is completely and efficiently expressed by prokaryotic strain DE 3 .

Discussion of the application of enzymatic reference methods in external quality assessment / 重庆医学

Objective To discuss the feasibility of enzymatic reference methods in Routine Chemistry external quality assessment (EQA)inlaboratorymedicine.Methods Samplesofthe1stEQAin2012byNationalCenterforClinicalLaboratories(NCCL)and patients′sera were measured by reference methods and 5 clinical analytic systems for the catalytic activity of CK ,LDH ,ALP ,ALT , AST ,GGT and AMY ,then the results of 5 clinical systems were compared with the reference methods′or target value of NCCL by calculating the bias ,and evaluated them according to the criteria of EQA by NCCL .Results The results of EQA samples measured by reference methods was within ± 10% compared with NCCL target value .Compared with the results of reference method ,the through put was 100 .0% for wet clinical chemistry systems measuring both EQA samples and patients′serum ,and the dry clinical chemistry systems was 77 .1 for EQA samples and 97 .1% for patients′serum according to the criterion of EQA ,and the through put was 72 .9% and 63 .6% of wet clinical chemistry systems according to the standard of enzymatic trueness of NCCL .Conclusion Reference method could be applied to EQA ,and will be a great help for the trueness of clinical testing .

Influence of some herbal medicines and foods on the INR of patients under warfarin therapy / 中华检验医学杂志

Warfarin is a well-accepted drug used for preventing thromboembolic diseases. It is important to monitor the dosage of warfarin. Prothrombin time is one of the screening tests of extrinsic coagulation path,which is the first choice to monitor the oral use of warfarin. Standardized prothrombin time, namely international normalized ratio ( INR ) is used to adjust warfarin dosage in clinical practice. Many herbal medicines and foods may enhance the effect of warfarin therapy,and some of them may weaken this effect,which can result in severe clinical complications.

Experimental Study on Anti-inflammatory, Diuretic Effect and Acute Toxicity of Herb of Lanceolate Sedge / 世界科学技术-中医药现代化

This study was aimed to investigate the anti-inflammatory, diuretic effect and acute toxicity of Herb of Lanceolate Sedge. The mice were randomly divided into 5 groups, which were the physiological saline group, aspirin group (0.05 g·kg-1), high dose (HD), middle dose (MD) and low dose (LD) of water extract of Herb of Lanceolate Sedge (10, 5, 2.5 g crude drug per kg) group. Intragastric administration of medication was given to mice once a day for 3 days. Auricular swelling induced by dimethyl benzene was used in the model establishment to calculate the swollen ear degree and the swollen inhibiting rate. And rats were randomly divided into 5 groups, which were the physiological saline group, aspirin group (0.05 g·kg-1), high dose (HD), middle dose (MD) and low dose (LD) of wa-ter extract of Herb of Lanceolate Sedge (10, 5, 2.5 g crude drug per kg) group. Intragastric administration of medi-cation was given to rats once a day for 5 days. Carrageenan induced paw edema was used in the model establishment to calculate the paw swollen rate. And rats were randomly divided into 5 groups, which were the physiological saline group, Furosemide tablets group (0.01 g·kg-1), high dose (HD), middle dose (MD) and low dose (LD) of water extract of Herb of Lanceolate Sedge (10, 5, 2.5 g crude drug per kg) group. Intragastric administration of medication was giv-en to rats once a day for 5 days. Water-loaded was used in the model establishment to calculate the 5-hour urine amount. The maximum tolerance dose (MTD) was used in the determination of the acute toxicity. The results showed that the three groups of HD, MD and LD of water extract of Herb of Lanceolate Sedge had obvious inhibiting effects on the swollen ear degree and the swollen inhibiting rate among mice, and the paw swollen rate of rats. It had signif-icant increasing effect on the 5-hour urine amount. The MTD of intragastric administration of water extract of Herb of Lanceolate Sedge was 640 g crude drug per kg for mice. It was concluded that Herb of Lanceolate Sedge dis-played obvious effects on anti-inflammatory and dieresis with low acute toxicity.

Evaluation of serum adenosine deaminase assays of different manufacturers and harmonization of test results / 中华检验医学杂志

Objective To Evaluate the performance of serum adenosine deaminase assays of different manufacturers and explore the approach for harmonization of test results.Methods It was evaluated the indice including the limit of blank ,precision,linearity range and reference interval of 10 test systems.It was as the reference system by Mindray test system to evaluate the comparability and the difference of ADA results among 10 different systems.The evaluation was performed before and after calibration by a selected fresh serum assigned by the reference system.A commercial calibrator of the minimum matrix effect was selected from 8 different calibrators as the long-term calibrator to harmonize the ADA results of 10 systems.Results The results of LoB were 0.1-6.3 U/L,respectively.The within-run CVs and total CVs of 10 systems were all less than 5%and actual linearity ranges were conformed to claims of manufacturers.After calibration with fresh serum calibrator ,the averaged difference of 10 test systems was reduced from 14% to 3.0%, and the average difference was 1.8% after calibration with long-term calibrator.The common reference interval of all test systems was 5-24 U/L identically.Conclusions The comparability of ADA measurements can be improved by using a common human serum calibrator and the commutable commercial calibrator.And it is necessary and feasible to develop the standardzation of ADA.