Clinical application of mass spectrometry technology has attracted the attention of clinical laboratory experts due to its high sensitivity, high specificity, and capacities of simultaneous detection of multiple compounds. In recent years, mass spectrometry technology has made significant achievements in the fields of identification of pathogenic microorganism, detection of trace elements and heavy metals, small molecule hormones, vitamins, amino acids, peptides and proteins, as well as therapeutic drug monitoring (TDM) and poisoning drugs screening. In order to further clarify the opportunities and challenges brought by this complex mass spectrometry technology in the field of clinical laboratory, the Chinese Journal of Laboratory Medicine invited experts and scholars of laboratory medicine to share their experience and opinions on related items focusing on the positioning of mass spectrometry technology in the clinical laboratory, the development and improvement of the clinical laboratory by mass spectrometry technology, the challenges of interpreting mass spectrometry test results, the challenges of operating and managing clinical mass spectrometry laboratories, and ways of improving the application of clinical mass spectrometry laboratories with this technology. Agreement was achieved in that the introduction of mass spectrometry technology into the clinical laboratory could bring new directions and opportunities for clinical testing and research, and also is associated with a series of challenges such as the difficulty of sample pretreatment, the high cost and complexity of mass spectrometry technology, the complexity of data processing and interpretation, the lack of standards and norms, and the issue of determining the price of mass spectrometry examinations.

Objective:To construct an artificial intelligence (AI)-assisted system based on deep learning for corneal in vivo confocal microscopy (IVCM) image recognition and to evaluate its value in clinical applications. Methods:A diagnostic study was conducted.A total of 18 860 corneal images were collected from 331 subjects who underwent IVCM examination at Renmin Hospital of Wuhan University and Zhongnan Hospital of Wuhan University from May 2021 to September 2022.The collected images were used for model training and testing after being reviewed and classified by corneal experts.The model design included a low-quality image filtering model, a corneal image diagnosis model, and a 4-layer identification model for corneal epithelium, Bowman membrane, stroma, and endothelium, to initially determine normal and abnormal corneal images and corresponding corneal layers.A human-machine competition was conducted with another 360 database-independent IVCM images to compare the accuracy and time spent on image recognition by three senior ophthalmologists and the AI system.In addition, 8 trainees without IVCM training and with less than three years of clinical experience were selected to recognize the same 360 images without and with model assistance to analyze the effectiveness of model assistance.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Renmin Hospital of Wuhan University (No.WDRY2021-K148).Results:The accuracy of this diagnostic model in screening high-quality images was 0.954.Its overall accuracy in identifying normal/abnormal corneal images was 0.916 and 0.896 in the internal and external test sets, respectively.Its accuracy reached 0.983, 0.925 in the internal test sets and 0.988, 0.929 in the external test sets in identifying corneal layers of normal and abnormal images, respectively.In the human-machine competition, the overall recognition accuracy of the model was 0.878, which was similar to the average accuracy of the three senior physicians and was approximately 300 times faster than the experts in recognition speed.Trainees assisted by the system achieved an accuracy of 0.816±0.043 in identifying corneal layers of normal and abnormal images, which was significantly higher than 0.669±0.061 without model assistance ( t=6.304, P<0.001). Conclusions:A deep learning-based assistant system for corneal IVCM image recognition is successfully constructed.This system can discriminate normal/abnormal corneal images and diagnose the corresponding corneal layer of the images, which can improve the efficiency of clinical diagnosis and assist doctors in training and learning.

Objective:To investigate the application effect of research-assisted teaching mode in histology teaching by taking the construction of rat spinal cord injury model as an example.Methods:A convenient sampling method was used to select 52 freshmen majoring in clinical medicine of grade 2020 in our school as the research subjects.They were randomly divided into the conventional teaching group and the research-assisted teaching group,with 26 students in each group.The conventional teaching group received traditional classroom teaching combined with experimental teaching.On this basis,research elements were added to the experimental teaching in the research-assisted teaching group to provide more in-depth research methods and experimental design,so as to cultivate students'research abilities.The theoretical assessment and practical skills assessment of histology course were compared between the two groups.A subjective evaluation questionnaire on experimental animal models teaching was used to evaluate the advantages of teaching programs in three dimensions:psychological quality training,technical skill enhancement,and theoretical knowledge expansion.The research abilities of the two groups were compared.Pearson correlation analysis was used to analyze the correlation between research ability scores and comprehensive scores.Results:The usual score and comprehensive score in the research-assisted teaching group were significantly higher than those in the conventional teaching group(P＜0.05).The scores of adaptability to challenging tasks,determination and perseverance in problem-solving,communication skills in teamwork,literature reading,integration of practical experience with theoretical knowledge,practical application value of the course,and innovation of teaching resources in the research-assisted teaching group were higher than those in the conventional teaching group(P＜0.05).The scores in experimental design ability,background knowledge in literature review,communication and reporting skills,awareness of evidence-based medicine,and overall research ability in the research-assisted teaching group were higher than those in the conventional teaching group(P＜0.05).The total score of students'research abilities was positively correlated with comprehensive scores(r=0.716,P＜0.01).Conclusions:The application of research-assisted teaching significantly improved students'research abilities in histology teaching.The enhancement of research abilities can promote the mastery of theoretical knowledge and the improvement of experimental skills.

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 construct a prokaryotic expression vector for human retinol binding protein 4 (hRBP4) that allows technicians to obtain hRBP4 purified protein with low cost, high efficiency, high concentration and high purity.Methods:The hRBP4 coding sequence provided by National Center for Biotechnology Information was optimized by E. coli codons, and a synthetic DNA fragment was cloned into the PET-28A (+) prokaryotic expression vector to construct a recombinant hRBP4 expression plasmid. The recombinant protein was transformed into E. coli BL21, and the induced expression conditions (temperature, rotate speed and isopropyl β-d-thiogalactoside concentration) were optimized. The recombinant protein was purified by His fusion tag. Results:The recombinant hRBP4 prokaryotic expression plasmid was successfully constructed, and the expression concentration and induction temperature of the recombinant protein were optimized. The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that a band with a relative molecular weight of 26 000 daltons was clearly visible in the purified product. The purified hRBP4 protein could be detected clinically, and there was a good linear relationship between the dilution ratio and the detection concentration.Conclusions:The recombinant hRBP4 protein has high purity, high concentration, and short production cycle. It has the potential to become a candidate for reference materials for laboratory quality evaluations.

Venous thromboembolism is one of the serious and common complications of gynecological malignant tumors, and it is also the main cause of death of patients besides the tumor itself. Nursing staff plays an important role in the prevention of venous thrombosis. Step-by-step systematic nursing intervention can effectively reduce the occurrence of venous thrombosis. This article reviews the research progress of prevention and nursing of perioperative venous thromboembolism in patients with gynecological malignant tumors, aiming to provide help for the establishment and effective implementation of preventive nursing strategies for venous thromboembolism in patients with gynecological malignant tumors.

Accurate determination of drug concentration in blood samples is a necessary prerequisite for therapeutic drug monitoring (TDM) and the implementation of precise drug treatment, and it is also one of the important tasks of clinical laboratories.TDM plays an important role in clinical treatment in immunosuppressants (cyclosporine A, tacrolimus), psychotropic drugs (valproic acid, carbamazepine) and other drugs that require monitoring of drug concentration. There are many types of methods used for TDM for the detection of drug concentration in blood samples. At present, only a few immuno-assay methods were approved for marketing with detection systems and kits, most methods used for TDM are high performance liquid chromatography or liquid chromatography-tandem mass spectrometry which belong to laboratory developed tests (LDTs). Detection of TDM samples has many problems, such as incomparable testing results and large bias between different testing systems, including the biasbetween both different methods and different laboratories using the same method. There are several reasons:(1) the traceability chain has not been established, (2) the methods have not yet been standardized, (3) the coverage of the EQA plan is insufficient, (4) the awareness of TDM laboratories to participate in the EQA plan is insufficient, (5) TDM standardization is still in its infancy. These problems restrict the clinical application of TDM and the development of related research work. In order to solve these problems, it is necessary to: (1) Establish a reference system to realize the traceability of the test results; (2) While gradually increasing the TDM EQA plan items, the Trueness evaluation plan should be carried out as soon as possible; (3) Standardized TDM sample testing Technology; (4) Strengthen laboratory management and establish a complete quality management system.

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.

Objectives:To establish a candidate reference method of isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) for the determination of human plasma normetanephrine, and to evaluate the performance of the method. The method was used to quantify the samples of the external quality assessment program, and to initially evaluate the detection status of plasma normetanephrine.Methods:The isotope standard solution of normetanephrine was selected as the internal standard, the gravimetric method was used for sampling, and the standard curve method was used for quantification. Protein precipitation combined with weak cation solid phase extraction was used for pretreatment, and ultra-high liquid chromatography-coupled triple quadrupole mass spectrometry was used for LC/MS analysis. According to the relevant EP documents, the specificity, matrix effect, detection limit, quantification limit, precision, accuracy, and uncertainty of the method were estimated. This method is used to quantify the samples of the 2020 National Center for Clinical Laboratories external quality assessment program of normetanephrine. Taking the average value of this method as the target value, the optimal allowable total error standard of biological variation as the evaluation limit, the quality of the laboratory testing was evaluated.Results:The method had good specificity, and the interferences and matrix effects did not affect the detection results. The detection limit and quantification limit of plasma normetanephrine were 1.08 pg/g and 3.54 pg/g, respectively. The intra-batch coefficient of variation ( CV) and total CV were 0.43%-1.10% and 0.61%-1.42%, respectively. The relative recovery rates were 98.5%～101.9%. The relative expansion uncertainty of the four plasma samples were 3.10%, 2.34%, 2.16%, and 1.73%, respectively. The results of the external quality assessment program showed that the pass rates of the 202013 and 202014 samples were 80% and 85%, respectively. Conclusions:The study established a candidate reference method of ID-LC/MS/MS for the measurement of plasma normetanephrine. The method is accurate, precise and simple, and is expected to be used as a reference method for the determination of plasma normetanephrine, and can be applied to quantify the samples of the external quality assessment program.