Objective:To investigate the application value of metagenomic next-genera-tion sequencing (mNGS) in pathogenic diagnosis of suspected infected severe acute pancreatitis (SAP).Methods:The prospective study was conducted. The clinical data of 25 patients with suspected infected SAP who were admitted to the Xiangya Hospital of Central South University from May to September 2023 were collected. Upper limb venous blood samples of all the patients were collected for both of mNGS and routine pathogen microbial culture. Observation indicators: (1) grouping situations of the enrolled patients; (2) comparison of the diagnostic efficiency of mNGS and routine pathogen microbial culture; (3) results of peripheral blood pathogen microbial testing and peri-pancreatic effusion microbial culture; (4) testing time and cost. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3). Count data were expressed as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. Results:(1) Grouping situations of the enrolled patients. A total of 25 patients were selected for eligibility. There were 18 males and 7 females, aged 48(40,59)years. The duration of hospital stay of 25 patients was 30(20,50)days. The etiologies of 25 patients included 14 cases of hyperlipidemic pancreatitis, 8 cases of biliary pancreatitis, 1 case of alcohol-induced acute pancreatitis, and 2 cases of pancreatitis caused by other causes. Of the 25 patients, there were 17 cases with infected pancreatic necrosis (IPN) including 7 cases of death, and 8 cases with sterile pancreatic necrosis including no death. (2) Comparison of the diagnostic efficiency of mNGS and routine pathogen microbial culture. The positive rates of mNGS and routine pathogen microbial culture in diagnosis of suspected infected SAP were 72.0%(18/25) and 32.0%(8/25), respectively, showing a significant difference between them ( χ2=8.01, P<0.05). The sensitivity and negative predic-tive value of mNGS and routine pathogen microbial culture in diagnosis of IPN were 94.1%(16/17), 35.3%(6/17) and 85.7%(6/7), 35.3%(6/17), showing significant differences between them ( χ2=12.88, 5.04, P<0.05). The specificity and positive predictive value of mNGS and routine pathogen microbial culture in diagnosis of IPN were 75.0%(6/8), 75.0%(6/8) and 88.9%(16/18), 75.0%(6/8), showing no significant difference between them ( χ2=0, 0.82, P>0.05). (3) Results of peripheral blood pathogen microbial testing and peripancreatic effusion microbial culture. Of the 17 patients with IPN, 36 strains of pathogenic bacteria were detected by mNGS, and 6 strains were detected by routine pathogen microbial culture. There were 16 of 17 patients with IPN showing positive mNGS pathogenic testing, of which 13 cases were consistent with the pathogenic testing results of peri-pancreatic effusion microbial culture, showing a consistency rate of 76.5%(13/17). There were 6 pati-ents with IPN showing positive routine pathogen microbial culture, with a consistency rate of 35.3%(6/17) to peripancreatic effusion microbial culture. (4) Testing time and cost. Testing time of mNGS and routine pathogen microbial culture were (43±17)hours and (111±36)hours, showing a signifi-cant difference between them ( t=9.31, P<0.05). Testing cost of mNGS was (2 267±0)yuan/case, accoun-ting for 1.7% of the hospitalization expenses of (133 759±120 744)yuan/case. Testing cost of routine pathogen microbial culture was (240±0)yuan/case, accounting of 0.2% of the hospitalization expenses. Conclusion:mNGS has important value for early pathogenic diagnosis of suspected infected SAP, and has a high timeliness.

Background and Aims:Accurate early pathogen diagnosis is a breakthrough for improving the prognosis of infectious pancreatic necrosis(IPN)patients.However,there is currently a lack of efficient methods for early identification of IPN in clinical settings.This study was performed to assess the application value of next-generation sequencing technology based on metagenomic capture(MetaCAP)in the pathogen diagnosis of IPN. Methods:A prospective study was conducted on 29 patients suspected of having acute necrotizing pancreatitis at Xiangya Hospital of Central South University between January and July 2024.Blood samples were tested using MetaCAP and conventional pathogen culture.The results of peritoneal fluid pathogen culture were used as the gold standard to compare the diagnostic efficacy of the two methods. Results:Due to three cases lacking peritoneal fluid culture results,a total of 26 cases were included in the final analysis.The overall mortality rate was 23.1％(6/26).During hospitalization,9 cases(34.6％)were diagnosed with IPN.The sensitivity and negative predictive value of MetaCAP for diagnosing IPN were significantly higher than those of conventional pathogen culture(77.8％vs.11.1％,P=0.031;86.7％vs.65.2％,P=0.032),while the differences in specificity(76.5％vs.88.2％,P=0.689)and positive predictive value(63.6％vs.33.3％,P=0.347)between the two methods were not statistically significant.The average detection time for MetaCAP was 33(20-49)h,while microbial culture took 125(45-142)h,with a significant difference(P＜0.001).The average cost for blood MetaCAP testing was 2 500 yuan per case,but it accounted for only 1.19％of the average hospitalization cost. Conclusion:MetaCAP has significant value in the early pathogen diagnosis of IPN,with a shorter detection time,good testing efficacy,and health-economic value,demonstrating a promising clinical application prospect.

Objective:To establish a method for the determination of 2, 3-Butanedione (BUT) in the air of workplace, which including the process of collection by absorption in phosphoric acid aqueous solution and the process of analysis and detection by high performance liquid chromatography with derivatization.Methods:In October 2022, a porous glass plate absorption tube containing 10 ml of 0.01% phosphoric acid solution was used to collect BUT in the air of the workplace at a flow rate of 0.2 L/min. The absorption solution was derived by 2, 4-dinitrophenylhydrazine for 75 min and separated on a SB-C18 column (250 mm×4.6 mm, 5 μm) . At the column temperature of 30 ℃, the mixture of acetonitrile-water ( V∶ V, 1∶1) was eluted at the flow rate of 1.0 ml/min. It was detected by UV detector (λ=365 nm) , qualitatived by retention time and quantitatived by external standard. Results:It showed that BUT in phosphoric acid aqueous solution could be stored for at least 7 d at 4 ℃. There was a linear relationship within the determination range of 0.05-6.00 μg/ml, the linear regression equation was y=89.610 x+0.133, r=0.9999. The sampling absorption efficiencies were 98.33%-100.00%, the detection limit of the method was 0.005 μg/ml, the minimum detection concentration was 0.016 mg/m 3 (based on V0=3.0 L) . The recovery rates were 95.96%-102.44%, the intra batch precision were 4.36%-7.78%, and the inter batch precision were 4.96%-6.06%. Conclusion:The method has the advantages of simple operation, high sensitivity and good accuracy. It can prevent the loss and degradation of BUT. It can be used for the determination of BUT in the air of workplace.

Objective:To establish a method for the determination of 2, 3-Butanedione (BUT) in the air of workplace, which including the process of collection by absorption in phosphoric acid aqueous solution and the process of analysis and detection by high performance liquid chromatography with derivatization.Methods:In October 2022, a porous glass plate absorption tube containing 10 ml of 0.01% phosphoric acid solution was used to collect BUT in the air of the workplace at a flow rate of 0.2 L/min. The absorption solution was derived by 2, 4-dinitrophenylhydrazine for 75 min and separated on a SB-C18 column (250 mm×4.6 mm, 5 μm) . At the column temperature of 30 ℃, the mixture of acetonitrile-water ( V∶ V, 1∶1) was eluted at the flow rate of 1.0 ml/min. It was detected by UV detector (λ=365 nm) , qualitatived by retention time and quantitatived by external standard. Results:It showed that BUT in phosphoric acid aqueous solution could be stored for at least 7 d at 4 ℃. There was a linear relationship within the determination range of 0.05-6.00 μg/ml, the linear regression equation was y=89.610 x+0.133, r=0.9999. The sampling absorption efficiencies were 98.33%-100.00%, the detection limit of the method was 0.005 μg/ml, the minimum detection concentration was 0.016 mg/m 3 (based on V0=3.0 L) . The recovery rates were 95.96%-102.44%, the intra batch precision were 4.36%-7.78%, and the inter batch precision were 4.96%-6.06%. Conclusion:The method has the advantages of simple operation, high sensitivity and good accuracy. It can prevent the loss and degradation of BUT. It can be used for the determination of BUT in the air of workplace.

Objective To investigate the effect of down-regulating adenosine deaminase acting on RNA-1(AD AR1)on the radiosensitivity of lung adenocarcinoma cells.Methods Lentiviral transfection was used to establish an ADAR1 knockdown cell line based on A549 cells.Then the cells were divided into negative control(shNC)and ADAR1 knockdown(shADAR1)groups,which were followed by a single-dose irradiation of 0 Gy and 6 Gy X-rays.Western blotting and RT-PCR were utilized to detect the expression of AD AR1 at protein and mRNA levels,respectively.CCK-8 assay,wound healing assay and Transwell migration assay were applied to measure cell proliferation and migration abilities.Meanwhile,clone formation assay was performed to detect the effect of down-regulating ADAR1 on the radiosensitivity of A549 cells.Flow cytometry and Western blotting were conducted to detect the expression levels of apoptosis and apoptosis-related proteins Bax and Bcl-2.Immunofluorescence assay and Western blotting were used to detect the expression level of γ-H2AX.Comet assay was performed to detect the level of cellular DNA damage.Twelve female nude mice(4～6 weeks old,weighing 16～18 g)were divided into shNC group,shADAR1 group,shNC+ionizing radiation(IR)group and shADAR1+IR group,with 3 mice in each group.The growth of tumor of different groups was observed with subcutaneous tumorigenesis assay.Results Western blotting and RT-qPCR showed that the protein and mRNA expression of ADAR1 were significantly reduced in A549 shADAR1 cells(P＜0.05).CCK-8 assay,wound healing assay and Transwell migration assay indicated that down-regulation of ADAR 1 inhibited the proliferation and migration abilities of A549 cells,and this inhibition trend became more obvious(P＜0.01)after IR.Cell clone formation assay showed that the clone formation rate of both groups was decreased,with the increase of radiation dose.But the number of formed clones was lower in the shADAR1 group than the shNC group.Flow cytometry and Western blotting displayed that down-regulation of AD AR1 increased the apoptotic rate and Bax expression in A549 cells(P＜0.01)and decreased Bcl-2 expression(P＜0.05),and the apoptotic rate and Bax protein level were further increased in A549 shADAR1 cells after IR(P＜0.01),and the Bcl-2 protein level was further decreased(P＜0.01).The number of γ-H2AX foci and protein level in A549 shADAR1 cells were significantly increased after IR(P＜0.05),and the results of comet assay showed that the DNA damage was more obvious in A549 shADAR1 cells after IR(P＜0.01).Subcutaneous tumorigenesis assay in nude mice showed that the growth of subcutaneous tumour of A549 shADAR1 cells was significantly inhibited after IR(P＜0.01).Conclusion Down-regulation of ADAR1 significantly inhibits the proliferation and migration of A549 cells after IR and promotes apoptosis and DNA damage,and thereby increases the radiosensitivity of lung adenocarcinoma cells.

Humans ; Muscular Dystrophy, Duchenne/epidemiology* ; Prevalence ; Myocardium

Background Diacetyl (DC) is widely used in the food flavoring industry and excessive occupational exposure to DC can cause serious respiratory diseases. However, there is no corresponding national standard method for the determination of DC in the air of workplace. Objective To establish a method for the determination of DC in workplace air by high performance liquid chromatography using 4-nitro-o-phenylenediamine (NPDA) as precolumn derivatization. Methods DC in the air of workplace was collected by solution absorption method. This experiment used NPDA as the derivatization reagent. By adjusting acidity of solution and optimizing concentration ration of DC/NPDA, derivatization temperature, and time, a method for the determination of DC in workplace air was proposed, and its performance indexes such as linearity, detection limit, and lower limit of quantification were obtained. Sampling efficiency was evaluated by relative comparison method, and sample stability was evaluated by sample preservation test. Accuracy and precision of the method were evaluated by standard addition recovery test with blank samples, and an interference test was carried out by adding standard samples. The established method was applied to actual samples to evaluate its adaptability. Results A combination of 60 °C for 2 h was selected for derivatization because a higher derivatization reaction temperature and a longer reaction time associated with a higher derivatization efficiency. The solution was separated by SB-C18 column (250 mm×4.6 mm, 5 μm) at 30 ℃, using a mixture of methanol and water (v/v, 65%/35%) as mobile phase with an elution flow rate of 1.0 mL·min⁻¹, and was detected with a variable wavelength detector (λ_max=257 nm) by qualitative analysis based on retention time and quantitative analysis based on external standard method. In terms of the proposed method, the linear range of detection was from 5 μg·L⁻¹ to 2000 μg·L⁻¹, with a correlation coefficient of 0.9999, and a detection limit of 1.3 μg·L⁻¹, the quantitative detection of the lower limit was 4.3 μg·L⁻¹, with a sampling volume V₀ of 3.0 L, the minimum detection concentration was 4.3 μg·m⁻³, and the minimum quantitative concentration was 14.3 μg·m⁻³. The recovery rate was 99.1%-100.8%, the intra-batch precision was 0.5%-3.0%, and the inter-batch precision was 1.2%-2.0%. The average sampling efficiency of this method was 94.5%, and the sample could be stored at 4 °C for at least 14 d. The coexisting components in the air of the workplace did not interfere with the determination of DC. The DC content in the air of a flavor workplace was 5.86-8.85 mg·m⁻³. Conclusion A determination method for DC in workplace air by high performance liquid chromatography using NPDA as precolumn derivatization after being collected by 1.0% phosphoric acid absorbent is proposed and has the advantages of simple operation, high sensitivity, and good accuracy. With no DC loss and degradation, the method may satisfy the request for DC determination in the air of workplace.

【Objective】 To evaluate the application of monoclonal typing reagents and human anti-A/B antibodies for absorption-elution test in ABO grouping. 【Methods】 The specificity of monoclonal typing reagents and human anti-A/B antibodies with standard A, B, O and AB phenotypes at 4 ℃, room temperature, and 37 ℃ were compared. Affinity was evaluated by the titer, agglutination time and agglutination intensity of the reaction with A1/B cells. 29 samples with ABO discrepancy were tested to evaluate the ability of monoclonal typing reagents and human anti-A/B antibodies to detect weak antigens in absorption-elution test. 【Results】 The specificity and affinity of human anti-A/B antibodies are low, and monoclonal typing reagents have cross reactivity. Human anti-A/B antibodies can detect most weak antigens in absorption-elution test with no cross reactivity. 【Conclusion】 In ABO grouping, the human anti A/B antibody binding absorption-elution test can serve as a supplement method for identifying ABO weak antigens. Accurate results can be obtained with reasonable reagents and corresponding methodology in serological tests,thus ensuring the safety of blood transfusion.

【Objective】 To establish a rare blood group information supply platform in Shaanxi Province. 【Methods】 The rare blood group information supply platform consists of sample registration, result registration, donor files and inventory blood. The blood donation codes of voluntary blood donors were recorded for blood typing, and the antigen identification results of each blood group system were registered, all stored in the rare blood type information supply platform. When receiving an application for unusual or rare blood type missing multiple conventional antigens or a certain high-frequency antigen, the corresponding antigen negative blood donors and their blood status (in stock or not) were queried from the donor profile module of the platform, and the inventory of blood of rare blood type was monitored dynamically. 【Results】 The results showed that 5.060% (273/5 398) of rare Rh phenotype donors, 1.540‰ (51/33 010) of donors lacking multiple regular antigens, and 13 O-type donors lacking high-frequency antigens were recorded in the rare blood type information supply platform. Among them, 0.019‰ (3/158 484) of Jk(a-b-) phenotype, 0.436‰ (2/4 586) of Di(a+b-) phenotype, and 4.030‰ (8/1 983) of Fy (a-b+) phenotype were stored in the blood bank for rare blood type. 【Conclusion】 The establishment of rare blood group information supply platform can meet the urgent demand for blood of rare blood types in clinical practice and ensure the safety of blood transfusion.

【Objective】 To observe the distribution of non-ABO-HDN and its clinical relevance, so as to provide reference for clinical diagnosis and treatment. 【Methods】 A total of 287 cases of non-ABO-HDN recorded during January 2012 to August 2022 were enrolled and tested in our laboratory. The correlation between maternal history of blood transfusion, pregnancy, unexpected antibody titers, gender, ABO-HDN and transfusion therapy was analyzed by chi-square test. 【Results】 All 287 cases of non-ABO-HDN involved 13 kinds of unexpected antibodies of 6 blood group systems. Rh-HDN accounted for 96.17% (276/287), and anti-D-HDN accounted for 47.04% (135/287). The proportion of non-ABO-HDN patients without ABO-HDN requiring exchange/transfusion was significantly higher than that of non-ABO-HDN patients with ABO-HDN(P<0.05). The ratio of need for exchange/transfusion in the high titer group (>8) was significantly higher than that in the low titer group (≤8) (P<0.05). There was no significant difference in gender, mother′s history of blood transfusion, pregnancy and whether or not to exchange/transfusion (severity of illness). 【Conclusion】 Understanding the characteristics of non-ABO-HDN and the specific distribution of unexpected antibodies, the correlation between various factors and diseases and their clinical significance are conductive to timely taking necessary intervention measures and reducing the risk of complications.