Background: Clinical chemistry tests are most widely used in clinical laboratories, and diverse measurement systems for these analyses are available in China. We evaluated the imprecision of clinical chemistry measurement systems based on internal QC (IQC) data. Methods: IQC data for 27 general chemistry analytes were collected in February each year from 2013 to 2022. Four performance specifications were used to calculate pass rates for CVs of IQC data in 2022. Boxplots were drawn to analyze trends of CVs, and differences in CVs among different groups were assessed using the Mann–Whitney U-test or Kruskal– Wallis test. Results: The number of participating laboratories increased significantly from 1,777 in 2013 to 5,425 in 2022. CVs significantly decreased for all 27 analytes, except creatine kinase and lipase. Triglycerides, total bilirubin, direct bilirubin, iron, and γ-glutamyl transferase achieved pass rates > 80% for all goals. Nine analytes with pass rates < 80% based on 1/3 allowable total error were further analyzed; the results indicated that closed systems exhibited lower CVs than open systems for all analytes, except total protein. For all nine analytes, differences were significant between tertiary hospitals and non-tertiary hospitals and between accredited and non-accredited laboratories. Conclusions The CVs of IQC data for clinical chemistry have seen a continuous overall improvement in China. However, there is ample room for imprecision improvement for several analytes, with stricter performance specifications.

Objective: To analyze the characteristics of influenza virus detection in an influenza outbreak in schools, so as to provide a strategic basis for the treatment of influenza outbreaks in schools. Methods: A total of 1 702 samples were collected from 52 school influenza outbreaks reported in Linyi City in 2021-2022. The samples were divided into 3 types according to different symptoms during the management of the epidemic [group A:influenzalike illness (ILI) group; group B:mild illness group; group C:close contacts group]. Rt-PCR was used to detect influenza virus nucleic acid in the collected samples. The detection rate of influenza virus in the outbreaks was analyzed by χ2 test. Results: In total, 1 071 samples (62.93%) tested positive for influenza virus nucleic acid. Among them, 610 out of 726 samples (84.02%) were detected in group A, while 331 out of 634 samples (52.21%) were detected in group B. In group C, 130 out of 342 samples (38.01%) tested positive. The differences were statistically significant (χ2=260.71, P<0.01). In group A, males had a detection rate of 80.83% for influenza virus nucleic acid, compared to 91.36% for females. For group B, the rates were 53.31% for males and 50.87% for females. In group C, males had a rate of 30.72%, while females had a rate of 43.92%. Statistical significance for gender differences was observed only in groups A and C (χ2=12.67, 6.25, P<0.05). According to the days of onset, the detection rates of influenza virus nucleic acid among patients with onset 0-6 days were 56.30%, 74.49%, 89.35%, 86.23%, 69.67%, 62.75%, 34.33%, respectively, and the difference was statistically significant (χ2=128.27, P<0.01). Conclusions Mild cases and close contacts are likely key factors contributing to the prolonged emergence of new cases within classrooms during school influenza outbreaks. The progression of influenza symptoms is related to the risk of transmission.

Objective:To understand the pathogenic situation of hand, foot and mouth disease (HFMD) in Linyi City, and to analyze the gene characteristics of Coxsackievirus A10 complete VP1 region.Methods:The samples of HFMD cases from Linyi City in 2023 were tested for typing and strain isolation, and the VP1 gene of CV-A10 isolate was amplified and sequenced. The obtained sequences were compared with those in the NCBI database, and the phylogenetic tree was constructed for gene characteristics and molecular epidemiological analysis.Results:In 2023, a total of 861 samples of HFMD were collected, and 594 (68.99%) were positive for nucleic acid tests. The male to female ratio of positive cases was 1.56∶1. Children under 5 years old accounted for 81.65%, and the highest incidence season was from June to August (83.84%). CV-A6 was the main pathogen (84.51%), followed by CV-A10 (9.93%). The nucleotide and amino acid homology of VP1 gene sequence among 13 isolates were 93.29%-100.00% and 97.65%-100.00%, respectively. The nucleotide and amino acid homology with AF081300-Kowalik/USA/1950 was lower (75.95%-76.62%, 91.72%-92.41%). The amino acid and nucleotide homology with C2c was the highest (94.28%-96.76%, 98.28%-100.00%), and the genetic distance was the closest (0.04-0.06). Amino acid site variation analysis showed that compared with the prototype strain AF081300-Kowalik/USA/1950, the isolates had more site variation, while only some isolates had I80V, E141K, P147S, T219I, E240K and V261I mutations compared with the representative strain C2c. The genetic evolution tree showed that the isolates were all in the same clade as the C2c representative strains, and they all belonged to the C2c genotype, and the isolates were further divided into two smaller clades.Conclusions:In 2023, CV-A6 was the main pathogen of HFMD in Linyi City, followed by CV-A10. All CV-A10 isolates were C2c genotypes and can be divided into two evolutionary clades. Continuous monitoring and genetic characterization of CV-A10 should be strengthened.

To analyze the changes in lactate dehydrogenase, creatine kinase, creatine kinase isoenzyme, high-sensitivity troponin T, N-terminal B-type natriuretic peptide precursor, homocysteine, and novel inflammatory indices (neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, systemic immune-inflammation index) before and after competitions in amateur marathon runners, and to assess the effects of myocardial injury due to acute exercise and the value of novel inflammatory indices in marathon exercise monitoring. This paper is an analytical study. Amateur athletes recruited by Beijing Hospital to participate in the 2022 Beijing Marathon and the 2023 Tianjin Marathon, and those who underwent health checkups at the Beijing Hospital Medical Checkup Center from January to June 2023 were selected as the study subjects, and 65 amateur marathon runners (41 males and 24 females) and 130 healthy controls (82 males and 48 females) were enrolled in the study according to the inclusion criteria. Peripheral blood was collected one week before, immediately after, and one week after running, and routine blood tests, cardiac enzymes, infarction markers, N-terminal B-type natriuretic peptide precursor, and homocysteine were performed to calculate the values of novel inflammatory indexes. Wilcoxon signed-rank test and Spearman′s rank correlation analysis were used to compare the differences in the levels of each index between the amateur marathon population and the health checkup population, and to compare the changes and correlations of each index at the three time points in the amateur marathoners.The results showed that the neutrophil-lymphocyte ratios of the healthy physical examination population and 65 amateur marathoners 1 week before running were 1.73 (1.33, 2.16) and 1.67 (1.21, 2.16), the platelet-lymphocyte ratios were 122.75 (96.69, 155.89) and 120.86 (100.74, 154.63), and the systemic immune inflammation index was 398.62 (274.50, 538.69) and 338.41 (258.62, 485.38), etc.; on 1 week before running, immediately after running and 1 week after running, lactate dehydrogenase of 65 amateur marathon runners was 173.00(159.00, 196.50)U/L,284.00(237.50, 310.50)U/L, 183.00(165.50, 206.50)U/L, creatine kinase was 131.00(94.30, 188.20)U/L,318.00(212.00, 573.15)U/L,139.00(90.55, 202.40)U/L, creatine kinase isoenzyme was 2.50(1.76, 3.43)μg/L,6.24(4.87, 10.30)μg/L,2.73(1.57, 4.40)μg/L.In 65 amateur marathon runners, lactate dehydrogenase, creatine kinase, creatine kinase isoenzyme, high sensitivity troponin T, N-terminal B-type natriuretic peptide precursor, homocysteine, and novel inflammation markers were significantly elevated in the immediate post-run period compared with 1 week before the run, and the differences were statistically significant ( Z=-7.009, Z=-6.813, Z=-6.885, Z=-7.009, Z=-7.009, Z=-6.656; P<0.05 for the above indicators).Neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, and systemic immune-inflammatory index all showed significant positive correlation with the pre-and post-run rates of change of high-sensitivity troponin T ( ρ=0.28, P=0.03; ρ=0.31, P=0.01; ρ=0.27, P=0.03); these 3 markers were also significantly and positively correlated with the pre-and post-run rates of change in a collection of myocardial-related markers such as lactate dehydrogenase, creatine kinase, creatine kinase isozymes, high-sensitivity troponin T, N-terminal B-type natriuretic peptide precursor, and homocysteine, respectively( r=0.446, P=0.039; r=0.452, P=0.033; r=0.449, P=0.036).In addition, the platelet-lymphocyte ratio was positively correlated with the pre-and post-run rates of change in creatine kinase and creatine kinase isoenzymes( ρ=0.27, P=0.03; ρ=0.28, P=0.02).In conclusion, acute myocardial injury may be triggered during marathon exercise. Changes in novel inflammatory markers were significantly associated with changes in myocardial enzymes, infarction markers, N-terminal B-type natriuretic peptide precursors, and homocysteine, which may be of value for the prediction of myocardial injury during exercise.

To analyze the changes in lactate dehydrogenase, creatine kinase, creatine kinase isoenzyme, high-sensitivity troponin T, N-terminal B-type natriuretic peptide precursor, homocysteine, and novel inflammatory indices (neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, systemic immune-inflammation index) before and after competitions in amateur marathon runners, and to assess the effects of myocardial injury due to acute exercise and the value of novel inflammatory indices in marathon exercise monitoring. This paper is an analytical study. Amateur athletes recruited by Beijing Hospital to participate in the 2022 Beijing Marathon and the 2023 Tianjin Marathon, and those who underwent health checkups at the Beijing Hospital Medical Checkup Center from January to June 2023 were selected as the study subjects, and 65 amateur marathon runners (41 males and 24 females) and 130 healthy controls (82 males and 48 females) were enrolled in the study according to the inclusion criteria. Peripheral blood was collected one week before, immediately after, and one week after running, and routine blood tests, cardiac enzymes, infarction markers, N-terminal B-type natriuretic peptide precursor, and homocysteine were performed to calculate the values of novel inflammatory indexes. Wilcoxon signed-rank test and Spearman′s rank correlation analysis were used to compare the differences in the levels of each index between the amateur marathon population and the health checkup population, and to compare the changes and correlations of each index at the three time points in the amateur marathoners.The results showed that the neutrophil-lymphocyte ratios of the healthy physical examination population and 65 amateur marathoners 1 week before running were 1.73 (1.33, 2.16) and 1.67 (1.21, 2.16), the platelet-lymphocyte ratios were 122.75 (96.69, 155.89) and 120.86 (100.74, 154.63), and the systemic immune inflammation index was 398.62 (274.50, 538.69) and 338.41 (258.62, 485.38), etc.; on 1 week before running, immediately after running and 1 week after running, lactate dehydrogenase of 65 amateur marathon runners was 173.00(159.00, 196.50)U/L,284.00(237.50, 310.50)U/L, 183.00(165.50, 206.50)U/L, creatine kinase was 131.00(94.30, 188.20)U/L,318.00(212.00, 573.15)U/L,139.00(90.55, 202.40)U/L, creatine kinase isoenzyme was 2.50(1.76, 3.43)μg/L,6.24(4.87, 10.30)μg/L,2.73(1.57, 4.40)μg/L.In 65 amateur marathon runners, lactate dehydrogenase, creatine kinase, creatine kinase isoenzyme, high sensitivity troponin T, N-terminal B-type natriuretic peptide precursor, homocysteine, and novel inflammation markers were significantly elevated in the immediate post-run period compared with 1 week before the run, and the differences were statistically significant ( Z=-7.009, Z=-6.813, Z=-6.885, Z=-7.009, Z=-7.009, Z=-6.656; P<0.05 for the above indicators).Neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, and systemic immune-inflammatory index all showed significant positive correlation with the pre-and post-run rates of change of high-sensitivity troponin T ( ρ=0.28, P=0.03; ρ=0.31, P=0.01; ρ=0.27, P=0.03); these 3 markers were also significantly and positively correlated with the pre-and post-run rates of change in a collection of myocardial-related markers such as lactate dehydrogenase, creatine kinase, creatine kinase isozymes, high-sensitivity troponin T, N-terminal B-type natriuretic peptide precursor, and homocysteine, respectively( r=0.446, P=0.039; r=0.452, P=0.033; r=0.449, P=0.036).In addition, the platelet-lymphocyte ratio was positively correlated with the pre-and post-run rates of change in creatine kinase and creatine kinase isoenzymes( ρ=0.27, P=0.03; ρ=0.28, P=0.02).In conclusion, acute myocardial injury may be triggered during marathon exercise. Changes in novel inflammatory markers were significantly associated with changes in myocardial enzymes, infarction markers, N-terminal B-type natriuretic peptide precursors, and homocysteine, which may be of value for the prediction of myocardial injury during exercise.

Objective To explore the clinical efficacy of single unicompartmental knee arthroplasty(UKA)and total knee arthroplasty(TKA)for the treatment of knee osteoarthritis.Methods A total of 21 patients who underwent TKA and 15 who underwent UKA were randomly recruited.Biomechanical tests were performed before surgery and at 6th and 12th month after surgery.A Vicon infrared motion capture system and Kistler three-dimensional force plate were used to simultaneously acquire the kinematic and kinetic data of the patients during stair walking.Results During stair ascent,the peak knee flexion moment in the TKA group was significantly lower than that in the UKA group;the time to peak knee flexion/adduction moment,knee flexion moment impulse,and load rate of the peak knee adduction moment in the UKA group were significantly lower than those in the UKA group.During stair descent,the peak knee extension power in the UKA group was significantly lower before surgery and at 6th month after surgery;the load rate of the peak vertical ground reaction force was significantly higher before surgery and the peak knee extension moment was significantly greater at 6th month after surgery;at 12th month after surgery,there was no significant difference in the biomechanical characteristics during stair ascent and descent.Conclusions The TKA and UKA groups showed similar knee joint function after surgery;however,compared with the UKA group,the TKA group may adopt a different lower extremity biomechanical pattern.The UKA group showed better quadriceps control after surgery and improved postural control during stair descent,whereas the TKA group adopted a conservative stair gait strategy to reduce the knee load.Compared with the peak moment,the time to peak moment and load rate of the peak moment were more sensitive indicators for determining the difference in the knee load.

Objective:The allowable total error ( TEa),allowable imprecision ( CV)and allowable bias( Bias)were recommended for 34 routine chemistry analytes in China. Methods:According to the performance specification setting mode newly determined at the Milan conference in Italy,the performance specification was derived based on components biological variation (BV)and current state of the art mode. The data(including EQA data and IQC data)of laboratories participating in the routine chemistry and lipids and lipoproteins EQA activities of the national center for clinical laboratories from 2019 to 2021 was collected through clinet-EQA. For the analytes with biological variation(BV)data,compared the'percentage difference′ of EQA data and the'in-control coefficient of variation of the month′ of IQC data of each research analyte with the three levels evaluation criteria derived based on BV,and calculated the percentage difference passing rate and CV passing rate of all batches in each year. When the passing rate reaches 80%,the performance specifications of this level met the requirements of the recommended performance specifications of the analyte. For the analytes without BV data or analytes whose performance specifications at three levels derived based on BV could not be used as recommended standards,the recommended performance specifications are derived based on the current state of the art. After obtaining the recommended TEa and allowable CV for each analyte,used the formula | Bias|≤ TEa-z? CV to derive the recommended allowable bias. Results:The results of TEa ( CV)% recommended by 34 analytes are as follows:K4.7(2),Na4(1.5),Cl4(1.4),Ca5(2),P9.6(3.9),Glu6.4(2.5),Urea8(3),UA12(4.1),Cre11(3.3),TP5(2),Alb5.2(2.4),TC8.6(2.7),TG13.5(5),HDL-C16.5(4.3),LDL-C20.5(6.2),ApoAⅠ16(5.3),ApoB 17.1(5.5),Lp(a) 24.1(10.4),TBil 12.4(5),DBil 20(7.3),ALT16(5),AST13.5(4.8),ALP17.5(4.8),AMY13.1(3.3),CK11.3(3.8),LDH11(3.9),CHE13.4(5.3),LIP20(6.9),Fe13.3(5.2),Mg14(4.5),Cu17.9(6.8),Zn15.1(6.4),γ-GGT10(3.3),α-HBDH18(5.8).The formula | Bias|≤ TEa-z? CV is used to derive the allowable bias of 34 analytes. Conclusions:For 34 clinical routine chemistry quantitative analytes,the allowable total error,allowable imprecision and allowable bias that meet the current state of the art of Chinese laboratories are recommended.

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 establish a predictive model for coagulation in the extracorporeal circuit in elderly hemodialysis(HD)patients.Methods:The retrospective case-control study included 196 elderly patients with chronic renal failure receiving 4-h hemodialysis for the first time at the blood purification center of our hospital between March 1, 2019 and January 30, 2022.All enrolled patients were treated with heparin or related drugs for anticoagulation(including unfractionated heparin and low molecular weight heparin), with 14 cases(7.1%)in the coagulation group with a coagulation grade ≥1.There were 182 cases(92.9%)in the non-coagulation group.Demographic data, vital signs in a sitting position and the resting state before dialysis and laboratory tests before dialysis were collected.After the prediction model was developed, it was validated in elderly patients with chronic renal failure aged ≥60 years receiving 4-hour hemodialysis for the first time at our hospital between February 1, 2022 and February 1, 2023.Results:There were significant differences in heart rate[(82.6±12.3)times/min vs.(74.4±11.1)times/min]and total cholesterol[(4.3±1.2)mmol/L vs.(3.2±1.2)mmol/L]between the coagulation group and the non-coagulation group( t=2.231, 2.012, P<0.05).Multivariate logistic analysis showed that the heart rate( OR=0.930, 95% CI: 0.871-0.993, P<0.05)and cholesterol( OR=0.623, 95% CI: 0.391-0.992, P<0.05)had an effect on blood coagulation in cardiopulmonary bypass.The area under the curve(AUC)for predicting cardiopulmonary bypass clotting by heart rate was 0.639(the optimal cutoff value was 71 beats/min), the AUC for predicting clotting by total cholesterol was 0.708(the optimal cutoff value: 4.275 mmol/L), and the prediction using the combination of heart rate and total cholesterol was more effective(AUC=0.735).The model was verified in 98 patients with good results(AUC=0.895). Conclusions:The initial coagulation risk of the extracorporeal circuit in elderly patients undergoing initial HD can be preliminarily estimated based on the nomogram.

Dizziness and vertigo are common clinical symptoms,which requires clinicians to timely identify dizziness and vertigo due to acute stroke,so as not to delay diagnosis and treatment.In previous studies,such stroke was usually attributed to subtentorial vascular lesions such as brainstem and cerebellum.With increasing reports of vestibular symptoms caused by supratentorial stroke,researchers have found that vestibular symptoms caused by stroke are not unique to supratentorial lesions.This paper expounds the morbidity,influencing factors,pathogenesis,clinical manifestations,examination methods,treatment and prognosis of vestibular symptoms related to supratentorial stroke,in order to improve the understanding of clinicians to this disease.