Objective: To propose an improved method for constructing the internal quality control (IQC) framework for ELISA assays and validate its efficacy by statistically analyzing IQC data from nine blood center laboratories. Methods: 1) IQC data was collected from nine blood centers and analyzed using a domestic HBsAg ELISA detection kit as an example. 2) Differences between IQC values across batches within Blood Center 1 were assessed. 3) Statistical analyses were performed on batch usage, number of batches used, days of use, number of QC points, batch-specific means, and coefficients of variation (CV) across all nine centers. 4) Using the improved construction method for IQC framework, provisional and permanent frames were established for batches within Blood Center 1 and Blood Center 9, followed by outlier determination. Results: 1) Statistically significant differences were observed in IQC data between batches within Blood Center 1 (P<0.01). It is recommended that both the control material/reagents and the control chart framework be replaced simultaneously. 2) There were substantial differences among 9 blood centers regarding the control material/reagent lot numbers used, the number of QC runs per batch, and the QC values for identical lots. Therefore, individual laboratories should establish their own IQC chart frameworks. 3) The improved IQC framework construction method for ELISA assays is as follows: provisional frames are established via frame-shifting, using the pre-experimental mean and cumulative coefficient of variation (CV) from the preceding batch. For batches used >20 days with >20 QC points, permanent frames are constructed by aggregating in-control data accumulated over ≥20 days with ≥20 points to calculate cumulative mean and standard deviation. The provisional and permanent frames constructed by this method identified all 26 extreme outliers across Blood Centers 1 and 9 as out-of-control. Among the 218 general outliers, 10 were classified as normal by the provisional frames, while the remainder were designated as warnings or out-of-control. This method effectively monitors assay stability. Conclusion: Based on the statistical analysis of IQC practices across blood centers of varying scales, combined with the inherent characteristics of ELISA assays and the batch-to-batch instability of reagents/QC materials, it is recommended to reconstruct QC charts upon lot changes. The proposed method—utilizing frame-shifting for provisional frames and establishing permanent frames based on cumulative data—is applicable to blood center laboratories of differing sizes and effectively monitors the stability of the ELISA assay process.

Objective To develop an erythrocyte-based delivery system for butyrylcholinesterase(BChE)that is capable of prophylaxis against organophosphorus nerve agents.Methods Recombinant BChE was produced and analyzed for oligomerization via polyacrylamide gel electrophoresis(PAGE)and Western blotting.A modified hypotonic preswelling method was employed to prepare BChE-loaded erythrocytes.The drug loading capacity and encapsulation efficiency were quantified using enzyme-linked immunosorbent assay(ELISA).Catalytic activity was assessed in vitro with an activity detection kit.The system was characterized via scanning electron microscopy(SEM),flow cytometry and a hematology analyzer.Results Recombinant BChE predominantly existed as dimers(85％dimer,15％monomer).The optimized volume ratio of erythrocytes to hypotonic solution was determined as 1:7.Compared with native and empty erythrocytes,BChE-loaded erythrocytes exhibited significantly higher catalytic activity(P＜0.001).The mean corpuscular volume of BChE-loaded erythrocytes increased(P＜0.001),while the mean content of corpuscular hemoglobin and hemoglobin in erythrocytes per 100 mL decreased(P＜0.001).SEM revealed no morphological differences(biconcave disc shape).Hypotonic preswelling moderately increased erythrocyte apoptosis(P＜0.001),but no statistical difference was observed between BChE-loaded and hypotonic-treated erythrocytes(P＞0.05).CD47 expression remained unchanged compared to native erythrocytes(P＞0.05).Conclusion The modified hypotonic preswelling method can generate BChE-loaded erythrocytes that retain the characteristics of native erythrocytes while conferring catalytic activity,offering a novel strategy for clinical intervention against organophosphorus poisoning.

ObjectiveTo systematically evaluate the efficacy and safety of omental wrapping technique for pancreaticojejunal anastomosis in preventing complications after pancreaticoduodenectomy. MethodsThis study was conducted according to the PRISMA guideline. English and Chinese databases including CNKI， Wanfang Data， VIP， CBM， the Cochrane Library， PubMed， Embase， and Web of Science were searched for clinical studies on omental wrapping technique for pancreaticojejunal anastomosis in preventing complications after pancreaticoduodenectomy published up to November 2022， and Stata 16 and Review Manager 5.4 were used to perform the meta-analysis. ResultsA total of 15 studies with 1 830 patients were included in this study. The meta-analysis showed that the omental wrapping group had a significantly lower overall incidence rate of postoperative pancreatic fistula （POPF） than the non-omental wrapping group （odds ratio ［OR］=0.30， 95% confidence interval ［CI］： 0.22‍ ‍—‍ ‍0.41， P<0.001）， and the subgroup analysis showed that the omental wrapping group had a significantly lower incidence rate of grade B/C POPF than the non-omental wrapping group （OR=0.29， 95%CI： 0.21‍ ‍—‍ ‍0.39， P<0.001）. Compared with the non-omental wrapping group， the omental wrapping group had significantly lower incidence rates of postoperative bile leakage （OR=0.30， 95%CI： 0.16‍ ‍—‍ ‍0.56， P<0.001）， postoperative hemorrhage （OR=0.35， 95%CI： 0.24‍ ‍—‍ ‍0.53， P<0.001）， delayed gastric emptying （OR=0.45， 95%CI： 0.31‍ ‍—‍ ‍0.64， P<0.001）， abdominal infection （OR=0.55， 95%CI： 0.40‍ ‍—‍ ‍0.75， P<0.001）， reoperation （OR=0.31， 95%CI： 0.18‍ ‍—‍ ‍0.54， P<0.001）， and death within 30 days after surgery （OR=0.42， 95%CI： 0.22‍ ‍—‍ ‍0.80， P=0.009）， a significantly earlier time to diet （mean difference ［MD］=-0.98， 95%CI： -1.84 to -0.11， P=0.03）， and a significantly shorter length of postoperative hospital stay （MD=-2.44， 95%CI： -4.10 to -0.77， P=0.004）. There were no significant differences between the two groups in the time of operation （MD=-13.68， 95%CI： -28.31 to -0.95， P=0.07） and intraoperative blood loss （MD=-17.26， 95%CI： -57.55 to -23.03， P=0.40）. ConclusionOmental wrapping can reduce the incidence rates of postoperative complications such as pancreatic fistula， bile leakage， postoperative hemorrhage， abdominal infection， and delayed gastric emptying， improve the prognosis of patients， and shorten the length of hospital stay， without increasing surgical difficulty or time of operation.

Objective:To prepare seven standard strains of 2019 novel coronavirus (2019-nCoV), including wild type (WT) strain, Beta variant, Delta variant, Omicron variants (BA.2, BA.5, BQ.1, XBB.1 branches), which could be used to apply for national standard strains.Methods:According to cytopathic effect (CPE), virus titer, whole-virus-genome-sequencing and detection of mycoplasma, the basic biological characteristics of clonal isolation were determined through plaque purification technology.Results:The CPE was mainly characterized by cell shrinkage and exfoliation in Vero cells after infection with seven 2019-nCoV clonal isolations (WT, Beta, Delta, Omicron, BA.2, BA.5, BQ.1 and XBB.1 branches). The result of mycoplasma detection were negative and titers of the clonal isolation from 2nd to 5th generations were stable at 10 5-10 8 TCID 50/ml; the electron microscope showed that the virions were all round or elliptical, with a diameter between 60 nm and 140 nm. The subtypes of 7 strains were identified by whole-virus-genome-sequencing and phylogenetic analysis, with genomic stability after the fifth successive generations of clonal isolation. Conclusions:The series clonal isolation of 2019-nCoV with typical CPE of coronavirus, clear morphological structure, good viral activity and stable genetic characteristics were prepared, and they could be used to apply for national standard strains.

Objective:To investigate the unqualified hepatitis C virus (HCV) detection result of blood donors from the served area of blood institutions.Methods:The data related to HCV markers detected of the first and repeat blood donors were collected from the system of practice comparison for the Chinese mainland blood institutions from 2017 to 2021. The anti-HCV reactive rate and the rates of anti-HCV negative but HCV-RNA reaction and all the relationship between rates and the annual, regional and different blood donors were statistically analyzed.Results:During 2017-2021, the number of anti-HCV reactive per 100 000 blood donors decreased from 444.3 to 250.44 in the served area of 22 blood institutions ( χ2=49.677, P<0.05). The number of HCV RNA detected positive per 100 000 anti-HCV negative increased from 0.69 to 2.05 year by year, but there was no statistical significance ( χ2=0.643, P>0.05). The anti-HCV unqualified rate was significantly different among regions ( χ2=3 260.283, P<0.05). The anti-HCV unqualified rate of the first blood donors was significantly higher than that of the repeated blood donors ( F=130.993, P < 0.05). The annual number of HCV RNA detected positive per 100 000 anti-HCV negative blood samples from donors ranged from 0 to 17.28. Conclusions:The anti-HCV unqualified rate of blood donors in the served area of 22 blood institutions decreased year by year. Compared with repeated blood donors, HCV infection should be emphasized in first-time blood donors. The implementation of HCV RNA test can detect out much more HCV infections and reduce the risk of transfusion transmitted infectious HCV.

Objective:To analyze the clinical characteristics and pathogenic distribution of severe pneumonia in adults in order to provide basis for clinical diagnosis and treatment.Methods:From June 2021 to April 2022, 145 patients with pneumonia admitted to the Department of Respiratory and Critical Care Medicine of the Second People's Hospital of Guangdong Province. According to whether they meet the diagnostic criteria for severe pneumonia, they were divided into severe ( n=63) and mild ( n=82) groups, and the clinical features between the two groups were compared. At the same time, the role of FilmArray detection in severe pneumonia was discussed. The measurement data were tested using independent sample t test or Mann-Whitney U test, and the counting data were tested using Chi-square test or Fisher exact probability method. Results:The age of the patients in the severe group was (72.67±1.71) years, male patients accounted for 84.1%, and the median hospitalization time was 16 days. Nine patients died in hospital; most of them had fever, shortness of breath, and change of consciousness, accompanied by hypertension, diabetes, cerebrovascular disease, chronic kidney disease, and tumor history. Compared with the mild group, the total number of leukocytes, neutrophil ratio, procalcitonin, and C-reactive protein were higher in the severe group, but the CD3 +, CD4 +, and CD8 + cell counts were lower ( P<0.05). The positive rate of FilmArray detection in the severe group was 81%, and the mixed infection of multiple bacteria accounted for 50%, which was higher than that of traditional culture ( P<0.05). The top four pathogens in severe group were Pseudomonas aeruginosa, Acinetobacter baumannii complex, Klebsiella pneumoniae, and Staphylococcus aureus, which were significantly higher than that in the mild group ( P<0.05). Resistance genes were detected in patients with severe disease, which was significantly higher than that in patients with mild disease (70.7% vs. 17.5%, P<0.05). Conclusions:Severe pneumonia is more common in elderly men, with more basic diseases and poor immunity. FilmArray has a high positive rate and can detect multiple pathogens, which may have a role in the rapid diagnosis of severe pneumonia.

【Objective】 To optimize the purification conditions of heparin affinity chromatography in the purification of human coagulation factor Ⅸ by response surface method and establish the optimal chromatography process parameters. 【Methods】 The effect of sample loading temperature on purification efficiency was analyzed through single factor test. Three-factor three-level response surface method was used to optimize the chromatographic elution conditions. The Folin phenol method and the automatic hemagglutination analyzer were used to determine the total protein content and human coagulation factor Ⅸ titer, respectively. The purification effect was evaluated by activity index and process recovery rate. 【Results】 The optimized optimal chromatographic conditions were loading at 5 ℃, washing 4 CV, eluent formulation of sodium citrate 20 mmol/L, arginine hydrochloride 18.7 mmol/L, NaCl 611.6 mmol/L and pH 7.5; under this optimal setting, the recovery rate of the chromatographic process was (46.6±2.9) %, titer of factor Ⅸ rated to (68.4±4.7) IU/mL and specific activity was (62.8±3.3) IU/mg. 【Conclusion】 The optimized parameters of heparin affinity chromatography process by response surface method can produce better purification effect on human coagulation factor Ⅸ.

Objective:To detect blood samples from clinically confirmed cases infected with the 2019 novel coronavirus (2019-nCoV) by fluorescence immunochromatography, colloidal gold immunoassay and micro neutralization test and compare differences in result and provide useful approaches to clinical and epidemiological investigation.Methods:The 2019-nCoV IgG/IgM antibody kit (Fluorescent immuno-chromatography) and the 2019-nCoV antibody test kit (Colloidal gold immunoassay) from Guangzhou Wanfu biotechnology Limited by Share Ltd, and the micro neutralization test established by a 2019-nCoV strain isolated by the laboratory in Guangdong Provincial Center for Diseases Control and Prevention were used to detect serum samples of clinically confirmed patients, in the Guangdong Province Second People′s Hospital, China.Results:A total of 113 serum samples from clinically confirmed cases infected with the 2019-nCoV were collected in Guangdong 2 nd People′s Hospital. The median age of the patients was 47.50 (32.00, 57.00) years and the gender ratio was 2.77∶1; The highest neutralizing antibody titer of micro neutralization test was 1∶1 024; Taking the result of micro neutralization test as gold standard, the sensitivity for colloidal gold immunoassay was greater than that of fluorescence immunochromatography (94.74% vs 82.46%), and the Kappa value for colloidal gold immunoassay and fluorescence immunochromatography was 85.84% and 75.24% respectively; at the same time, the negative predictive value and the positive predictive value for them were 94.44%, 91.53% and 83.87%, 92.16% respectively. Conclusions:In the serological method for the detection of the 2019-nCoV infection, the sensitivity and Kappa value for colloidal gold immunoassay were higher than those of fluorescent immunochromatography when the result of micro neutralization test was taken as the gold standard, which was more suitable for rapid detection of cases with the 2019-nCoV infection.

Objective:To establish quality control products for 2019-nCoV detection, and provide reliable control materials for the quality evaluations of the 2019-nCoV detection kit based on fluorescence PCR.Methods:Virus strain was diluted to concentrations of 10 6, 10 5, 10 4, 10 3, 10 2 copies/ml which were used as positive control products. The mean value, standard deviation, coefficient of variability (CV) and tendency of the Ct values were calculated. The homogeneity and stability of the quality control products were tested. Results:Within the concentration gradients, Ct value and concentration of the control products were linearly related. In homogeneity test, the CVs of the quality control products with concentrations of 10 6, 10 5, 10 4, 10 3, 10 2 and 0 copies/ml were 4.60%, 2.67%, 2.22%, 2.04% and 2.50% respectively. In stability test, there was no significant linear trend with extended test time at 4 ℃. Conclusion:Evaluations of homogeneity and stability indicated that the quality control products were established successfully. And the products can be used for evaluation of 2019-nCoV detection kit based on fluorescence PCR.

Objective:To understand the pathogenic spectrum and epidemiological characteristics of febrile respiratory syndrome in Guangdong province, and to provide reference for disease prevention, clinical diagnosis and treatment.Methods:The pathogens of 1 891 nasopharyngeal swabs collected from 2011 to 2018 were detected by real-time fluorescent polymerase chain reaction. The different rates were compared by chi-square test or Bonferronni method of comparison.Results:Among 1 891 samples, 810 samples were positive for viral nucleic acid, with a total detection rate of 42.78%. The main infectious agents were Parainfluenza virus (PIV), Rhinovirus (RhV) and Coronavirus(CoV). The pathogen detection rate was higher in <5 years group and 5~ years group. Pathogen detection in patients with different symptoms showed that the detection rate of Metapneumovirus (MPV) in pneumonia patients was relatively high. Influenza virus A (FluA), PIV, CoV and RhV had higher detection rate in patients without pneumonia. FLuA and Adenovirus (ADV)had a relatively high detection rate in the high and ultra-high fever groups. The detection rate of CoV and Mycoplasma pneumonia(MP) in moderate fever group was relatively high. The detection rate of PIV in cough patients was relatively high. The prevalence of several viruses has strong seasonality, and the detection rate was generally higher in winter and spring. Different virus detection rates also have strong regularity in years.Conclusions:PIV, RhV and CoV are the main pathogens of febrile respiratory syndrome in Guangdong in recent years.