Lead poisoning severely threatens human health with its cumulation and durability in the body. The analysis of lead in blood is vital for screening, diagnosis, treatment, and prognostication of lead poisoning and for indirectly monitoring the level of lead in the environment. Although the detection programs are available throughout our country, the accuracy and comparability of the results cannot meet the expectation. A variety of factors can affect the accuracy of blood lead testing. To promote the application of blood lead analysis in clinical trials and reduce the bias of results, a better reference system for blood lead analysis should be established to evaluate the accuracy of traditional methods, promote the standardization of blood lead analysis and achieve accurate blood lead testing.

Background: Serum C-peptide results from various routine methods used in China are highly variable, warranting well-performing methods to serve as an accuracy base to improve the harmonization of C-peptide measurements in China. We developed an accurate isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC–MS/MS) method for serum C-peptide measurement and explored its use in harmonization. Methods: After protein precipitation with ZnSO4 solution, C-peptide was extracted from serum samples by anion-exchange solid-phase extraction and quantified by ID-LC–MS/MS in positive ion mode. The precision and analytical recovery of the ID-LC–MS/MS method were assessed. Seventy-six serum samples were analyzed using the ID-LC–MS/MS method and six routine immunoassays. Ordinary linear regression (OLR) and Bland-Altman (BA) analyses were conducted to evaluate the relationship between the ID-LC–MS/MS method and routine immunoassays. Five serum pool samples assigned using the ID-LC–MS/MS method were used to recalibrate the routine assays. OLR and BA analyses were re-conducted after recalibration. Results: The within-run, between-run, and total precision for the ID-LC–MS/MS method at four concentrations were 1.0%–2.1%, 0.6%–1.2%, and 1.3%–2.2%, respectively. The analytical recoveries for the ID-LC–MS/MS method at three concentrations were 100.3%–100.7%, 100.4%–101.0%, and 99.6%–100.7%. The developed method and the immunoassays were strongly correlated, with all R2 >0.98. The comparability among the immunoassays was substantially improved after recalibration. Conclusions The performance of the ID-LC–MS/MS method was carefully validated, and this method can be used to improve the harmonization of serum C-peptide measurements in China.

Objective:To translate the English version of the Medical Office Survey on Patient Safety Culture (MOSPSC) into Chinese, and conduct cross-cultural adjustment and reliability and validity tests.Methods:After obtaining the authorization and consent of the original questionnaire agency in May 2018, forward translation, synthesis, back translation and expert consultation of the English version of MOSPSC were carried out to form the Chinese version of MOSPSC. From December 2018 to January 2019, convenience sampling was used to select the outpatient staff working in five ClassⅢ general hospitals in Chengdu as the research object to evaluate the reliability and validity of the questionnaire.Results:A total of 420 questionnaires were distributed, 396 valid questionnaires were recovered. The Chinese version of MOSPSC included 10 dimensions, 38 items, and another 3 items to investigate and evaluate the status quo of outpatient quality and safety issues. The Cronbach's alpha coefficient of the questionnaire was 0.901 for the employee level and 0.978 for the management level. The split-half reliability of the questionnaire was 0.907 for the employee level, 0.971 for the management level, and 0.408 to 0.975 for each dimension. The test-retest reliability of the employee level of the questionnaire was 0.960, and the test-retest reliability of each dimension was from 0.438 to 0.943. The item-level content validity index of the questionnaire was from 0.66 to 1.00, and the average scale-level content validity index of the questionnaire was 0.91.Conclusions:The Chinese version of MOSPSC maintains good equivalence with the source questionnaire after strict cross-cultural adjustment, and has good content validity, internal consistency reliability and test-retest reliability, which is suitable for the investigation of patient safety culture in the outpatient setting of China.

Objective:To establish the allowable total error (TEa) of the national external quality assessment (EQA) program in line with the current quality level of serum folate measurement in China.Methods:The data of serum total folate test in the clinical laboratory of a hospital in Beijing in 2016 were collected, and the Stata SE 15 software was used for Monte Carlo simulation to obtain the false-negative rate under different bias and inaccuracy conditions. The Origin Pro 9.1 software was used to make the contour figure. The TEa of serum total folate test is derived based on the acceptable false-negative rate. National EQA data of serum total folate in 2020 were collected to calculate the pass rate of participating laboratories and the laboratory pass rate of quality control products at each level under the five TEa derived from the analysis performance on clinical outcomes, biological variation, and the evaluation criterion of national EQA.Results:Based on the influence of analytical performance on clinical outcomes, the TEa was 10%. Under this TEa, the pass rate of the first EQA program of serum total folate in 2020 was more than 80%, and the pass rate of the second time was 73.1%. Under the minimum (46.57%) and appropriate level of TEa (15.52%) derived from biological variation and national EQA evaluation criterion, the pass rate of serum total folate in the two EQA programs in 2020 exceeded 85%.Conclusion:The analytical performance of serum total folate in China cannot meet the requirements of TEa derived based on the effect of analytical performance on clinical outcomes. An appropriate level of TEa derived based on biological variation (15.52%) is suggested as the recommended criterion for the TEa of serum total folate test.

Objective:To establish a candidate reference method for simultaneous determination of whole blood iron and copper based on ICP-MS technology.Methods:Cobalt (Co) was chosen as the internal standard, and was added gravimetrically into the standard solution and the whole blood sample. The whole blood sample was digested by electric heating plate and diluted. The isotopic ratios of 57Fe/ 59Co and 63Cu/ 59Co were measured by ICP-MS in the isotopic analysis mode. The precision, standard recovery and accuracy of the method were verified by measuring EQA materials and certified standard materials, and the performance of the method was further evaluated by method comparison. Results:The detection limit of iron is 0.136 mg/kg and the limit of quantification was 0.454 mg/kg in this method. The detection limit of copper in whole blood was 0.008 mg/kg and the limit of quantification was 0.027 mg/kg. The standard curve of copper ranges from 0.83-3.33 mg/kg, iron ranges from 167-667 mg/kg. The calibration curve of iron and copper was good linearity ( R 2>0.999 90). The precision of the method did well. The total CV range was 0.42%-0.68% for iron and 0.14%-0.94% for copper. The spike recoveries were all around 100%, the range of iron: 99.69%-100.07%; copper: 99.26%-100.51%. The correlation between this method and the existing clinical mass spectrometry methods was good. Conclusions:A candidate reference ICP-MS method for simultaneous determination of whole blood Fe and Cu was established. This is a simple and rapid method with good precision and spike recovery compared to the traditional one.

Objective:To establish an accurate quantitative method for the determination of serum glycated albumin (GA) based on isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS).Methods:This study optimized the ID-LC/MS method recommended by the Japan Society of Clinical Chemistry (JSCC). Albumin (Alb) was purified by anion exchange chromatography. The standard solution of purified sample, lysine (Lys) and deoxyfructosyl lysine (DOF-Lys) and their mixed internal standard were weighed accurately by weight method. The Alb was hydrolyzed to amino acid, and Lys and DOF-Lys were detected to determine GA. The method was evaluated and compared with the routine method.Results:The purity of Alb was 100%. The R 2 ranges of Lys and DOF-Lys linear standard curves were 0.997 8-0.999 9 and 0.999 4-1.000 0. The results of three-day precision evaluation of low, medium and high concentrations of serum were 0.69%-1.97%, 1.13%-2.33% and 1.37%-2.54% in intra, inter and total Coefficient of variation ( CV). In the accuracy evaluation, the deviations between the results of three concentration standards and the certified value were -2.56%, -1.87% and-2.94%. The matrix effects of Lys and DOF-Lys were 89.92% and 109.98%, and the carryover rates were -1.13% and -3.27% respectively. The detection limit and quantitative limit of Lys were 0.075 nmol/g and 0.248 nmol/g, and the DOF-Lys were 0.007 nmol/g and 0.024 nmol/g. The relative expanded uncertainty was 1.60%-2.03%. The fitting regression curve R 2 with the routine method was 0.970 7. Conclusions:A method was established for the detection of serum GA. The method evaluation was accurate and reliable. It was expected to be a candidate reference method for the detection of serum GA.

Objective: To investigate the influences of antibiotic-induced gut microbiota dysbiosis on Mycoplasma pneumoniae (Mp) airway infection. Methods: C57BL/6J mice were treated with vancomycin and gentamicin for 21 d by oral delivery and then intranasally infected with Mp. Quantitative real-time PCR (qPCR) was performed to detect five major phyla of gut microbiota in mouse fecal specimens before and after antibiotic treatment and the loads of Mp in lung tissues on 3 d and 7 d after infection. Pathological changes in lung tissues were evaluated with HE staining. IFN-γ and IL-4 secreted by spleen CD4⁺ T cells and CD8⁺ T cells were analyzed by flow cytometry. Mp-specific IgM and IgG in mouse serum samples were measured by indirect enzyme-linked immunosorbent assay (ELISA). Results: Vancomycin and gentamicin treatment significantly reduced the number of Bacteroidetes in mouse feces, but increased the amount of Firmicutes. Meanwhile, the numbers of δ, γ-Proteobacteria, Actinomycetes and Tenericutes also changed. These antibiotic-induced gut microbiota alterations in mice with Mp infection increased the loads of Mp in lung tissues and the pathological scores of lung tissue inflammation on 3 d and 7 d after infection, and reduced the number of IFN-γ-secreting spleen CD4⁺ T lymphocytes on 7 d. Conclusions Antibiotic-induced gut microbiota dysbiosis aggravated Mp airway infection.

Construction and application of immunization information system is an important part of health information, which is very useful to improve the quality, efficiency and safety of vaccination. The background, system architecture, functions and applications, working conditions and characteristics of Shandong province Immunization Information System (IIS) are introduced in this article. It is expected to provide experiences for the development of immunization information system of other provinces.

Objective To evaluate the comparability and consistency of two kinds of triglycerides reference methods, one of which is the isotope dilution liquid chromatography-mass spectrometry (LC/MS) in the Cholesterol Reference Method Laboratory Network (CRMLN), the other isthehigh-performance liquid chromatography (HPLC) method for triglyceride detection in China. Methods 52 fresh frozen sera with triglycerides levels among 0.45-4.52 mmol/L were determined by LC/MS and HPLC. After evaluation the precision and accuracy of the two methods,a series of analyses were conducted including plotting to scatter plots and deviation graphs, testing outliers, selecting the best fitting regression models and calculating the regression equations and parameters, and so on. The expected deviation at the level of medical decision of triglycerides and the 95％confidence range were statistically analyzed.Results For HPLC method, the CV of instrument measurement was 0.29％(0％-1.16％), the total CV of samples measurement was 0.54％(0.04％-1.28％), and the average bias of the reference materials was 0.22％(-0.43％-0.68％). ForLC/MSmethod,the CV of instrument measurement was 0.55％(0％-1.68％),the total CV of samples measurement was 0.79％(0％-1.93％), and the average bias of the NIST reference materials was 0.09％(-0.73％-1.29％). No outlier was found from the scatter plots and the statistical analysis and the linear regression was fitted to analyze the results of the two methods. The linear regression parameters of two methods for 52 fresh frozen human sera were as follows:the slope was 0.9988,the standard error of slope was 0.0035, the intercept was 0.0037mmol/L, the standard error of intercept was 0.0030 mmol/L, the standard error of Y-estimate was 0.0236 mmol/L,and the correlation coefficient was 0.9997. Compared with the LC/MS method,the absolute deviation of fresh sera by HPLC method was-0.001 mmol/L (-0.070-0.056 mmol/L), with a relative deviation of 0.13％ (-2.01-2.83％). T-test showed no statistically significant difference between the two methods. The expected deviations at the triglycerides medicine decision level were within the 95％confidence range,and the expected deviations were far less than the allowable error. Conclusions The HPLC method of triglyceridesdetetion has good consistency and comparability with LC/MS method as one of the reference methods of CRMLN. Because of the advantages of HPLC method such as low cost, simplicity,less technical need,and better precision,HPLC method is expected to play an important role in the process of standardization and traceability of serum triglycerides.

Objective Accurate measurement of aldosterone is critical in the diagnosis of primary aldosteronism. We compared the harmonization of three assays including isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) and two chemiluminescence immunoassays (CLIAs:system A and system B) for the aldosterone measurement. Methods A total of 45 plasma samples, 4 quality control materials, 5 lyophilized bovine serums, and 3 fresh frozen human serum pools were measured by three assays respectively. Based on CLSI EP15-A3 rule, the precision was assessed by coefficient of variance. Deming regression and Bland&Altman plots was performed for method comparison, and correlation coefficient was calculated for concordance (CCC). Results All three methods met the performance criteria based on desirable biological variation for precision (<7.35％). System A showed a relevantly good correlation and comparability with ID-LC/MS/MS (R2=0.985, CCC=0.967), while System B showed relevantly bad correlations and comparability with both System A (R2=0.538, CCC=0.605) and ID-LC/MS/MS (R2=0.547, CCC=0.528).. However, the average relevant bias of two CLIAs exceeded the bias requirement derived from biological variation (18.60％). Conclusion Significant differences were found in the measurement of plasma aldosterone using ID-LC-MS/MS and two CLIAs, which urges the establishment of traceability hierarchy and improvement of reagents' specificity for standardization of aldosterone measurement in clinical settings.