Objective To assess the consistency of four standardized cystatin C particle-enhanced turbidimetric assay (PETIA) and one particle-enhanced nephelometric immunoassay (PENIA) measurement systems Methods Performance verification test was conducted according to CLSI EP 15-A2 and EP9-A2. Fourty serum samples in comparative test were obtained from the remaining serum samples of outpatients in Peking Union Medical College Hospital in March 2013.Fourty serum samples were tested on Olympus AU5400 automatic biochemical analyzer ( four PETIA Cys C reagents:Shanghai Jingyuan Co ., Ltd, Beijing Leadman Biochemistry Co ., Ltd, Beijing Strong Biotechnologies , Maker Biotechnology in Sichuan , and labelled as A, B, C, D respectively) and PENIA N Latex Cys C measurement system on Siemens BNⅡ(labelled as E).Correlation analysis were performed among four PETIA methods one PENIA method Differences of each detection system were compared in the medical decision level 1,2,3,4 mg/L.The reference material ERM-DA471/IFCC was measured by five systems and bias ( percentage bias ) was calculate for each system.Results Results of systems A, B, C, D, E were 1.29(0.89-2.43), 1.30 (0.96-2.59), 1.22(0.90-2.44), 1.27(0.96-2.47), 1.14(0.82-2.05)mg/L.Chart shows bias among these five systems was small when Cys C concentration was less than 4mg/L.PETIA method A, B, C, D correlated with their mean value well , with the average deviation from their mean value ( percent deviation) at -0.017 -0.031 mg/L ( -3.1%-2.1%), and all were less than allowed bias from the biological variation (3.4%).The deviation of PETIA method A, B, C, D with their mean value in medical decision level at -0.176 -0.178 mg/L.Systems A, B, C, D correlated well with the result of PENIA method system E , and the mean deviation ( percent deviation ) was at 0.278 -0.326 mg/L ( 12.6%-18.5%) , and the deviation ( percent deviation ) in the medical decision level 0.055 -1.079 mg/L (5.51%-26.98%).Bias of PETIA method A, B, C, D Cys C system measuringERM -DA471/IFCC ranged from 0.22 to 0.39 mg/L ( 3.9%-7.0%) , which exceeded the allowable range of the reference material target value, and were larger than the allowable bias from biological variation (3.4%).Bias ( percent ) of PENIA method system E was -0.1 mg/L ( -1.7%) , within the allowable range of ERM-DA471/IFCC target value .Conclusions The consistency of four assesed PETIA Cys C reagents was relatively ideal, and improved markably after being traced to ERM-DA471/IFCC.Besides, the results of PETIA were higher than those of PENIA .Bias among these five systems was small when Cys C concentration was less than 4 mg/L, and the bias became larger in higher Cys C concentration.

Objective To assess the interference by calcium dobesilatein 7 peroxidase-baseduric acid assays and to determine its clinical significance.Methods In the in vitro experiments, uric acid in pooled serum with final concentrations of calcium dobesilate additions (0, 2, 4, 8, 16, 32, and 64μg/ml) were measured by 7 peroxidase-based assays.Percent Bias (%) was calculated relative to the drug-free specimen.In the in vivo experiments, changes in serum uric acid and calcium dobesilate concentrations were observed before and after calcium dobesilate administration ( baseline, 0 h, 1 h, 2 h, 3 h, 4 h, 6 h ) involunteers.The interference in different assays was assessed compared with LC-IDMS/MS method. Calcium dobesilate levels in 40 specimens from those taking calcium dobesilate were measured by HPLC method.Of the 40 specimens, 10 were selected to analyse the levels of uric acid by both peroxidase and UV measurement method to assess the impact in clinical status.Results In the in vitro study, concentrations of uric acid measured by 7 peroxidase-based assays were reduced by -6.3%to -21.2%compared with drug-free serum, when theconcentration of calcium dobesilate was16μg/ml.In the in vivo study, comparedto UA levels at 0 h, the biasesof serum uric acid determined by peroxidase method after calcium dobesilate administration(1 h, 2 h, 3 h, 4 h, 6 h) were of -3.33%, -6.79%, -7.49%, -6.07%, -4.09%, respectively.The observed uric acid concentrations for 8 participants measured by enzymatic assays were inhibited by -3.75% to -6.89% at 0 hour and by -16.9% to-22.22% at 2 hours relative to the concentrations measured by the LC-IDMS/MS method. Conclusions Calcium dobesilate produced a clinically significant negative interference with uric acid in all peroxidase-based uric acid assays,which may result in false evaluation of uric acid level in clinical status.Significant differences in the degree of interference were observed among the assays.

ObjectiveTo investigate the prevalence rate of gallstones among university teachers in Tianjin, China, and related risk factors. MethodsPhysical examination data were collected from the teachers from five universities who participated in physical examination in Physical Examination Center, Tianjin Medical University Cancer Institute and Hospital, in 2015, and abdominal ultrasound was used for the diagnosis of gallstones. The chi-square test was used for comparison of categorical data between groups. Univariate and multivariate logistic regression analyses were used to identify the risk factors for gallstones in the teachers from different universities, and a meta-analysis was used for the pooled analysis of prevalence rate and risk factors. ResultsA total of 8006 university teachers were enrolled, among whom 440 were diagnosed with gallstones, and the pooled prevalence rate of gallstones was 5.5%. The meta-analysis showed that hypertension (odds ratio ［OR］=1.67, 95% confidence interval ［CI］: 1.32-2.12, P＜0.001), fatty liver (OR=1.39, 95%CI: 1.12-1.72, P＜0.001), kidney stones (OR=1.90, 95%CI: 1.15-3.14, P=0.01), and high levels of hexokinase (OR=1.42, 95%CI: 1.03-1.94, P=0.03), alanine aminotransferase (OR=1.32, 95%CI: 1.01-1.73, P=0.04), and globulin (OR=1.74, 95%CI: 1.08-2.79, P=0.02) were risk factors for gallstones. ConclusionThere is a relatively low prevalence rate of gallstones among university teachers in Tianjin, and hypertension, fatty liver, kidney stones, and high levels of hexokinase, alanine aminotransferase, and globulin may be the risk factors for gallstones.

Anthrax is a highly lethal infectious disease caused by the spore-forming bacterium Bacillus anthracis. The major virulence factor of B. anthracis consists of protective antigen (PA), lethal factor (LF) and edema factor (EF). PA binds with LF to form lethal toxin (LT), and PA binds with EF to form edema toxin (ET). Antibiotics is hard to work in advanced anthrax infections, because injuries and deaths of the infected are mainly caused by lethal toxin (LT). Thus, the therapeutic neutralizing antibody is the most effective treatment of anthrax. Currently most of the anthrax toxin antibodies are monoclonal antibodies (MAbs) for PA and US FDA has approved ABTHRAX humanized PA monoclonal antibody for the treatment of inhalational anthrax. Once B. anthracis was artificially reconstructed or PA had mutations within recognized neutralization epitopes, anti-PA MAbs would no longer be effective. Therefore, anti-LF MAbs is an important supplement for anthrax treatment. Most of the anti-LF antibodies are murine or chimeric antibodies. By contrast, fully human MAbs can avoid the high immunogenicity of murine antibodies. First, we used LF to immunize the transgenic mice and used fluorescent cell sorting to get antigen-specific memory B cells from transgenic mice spleen lymphocytes. By single cell PCR method, we quickly found two strains of anti-LF MAbs with binding activity, 1D7 and 2B9. Transiently transfected Expi 293F cells to obtain MAbs protein after purification. Both 1D7 and 2B9 efficiently neutralized LT in vitro, and had good synergistic effect when mixed with anti-PA MAbs. In summary, combining the advantages of transgenic mice, fluorescent cell sorting and single-cell PCR methods, this study shows new ideas and methods for the rapid screening of fully human monoclonal antibodies.