Objective:To explore the application of COVID-19-specific IgG antibody in identifying epidemic Omicron BA.5 strain infection.Method:Omicron BF.7/BA.5 naturally infected population, healthy population vaccinated with the COVID-19 vaccine, and Omicron BF.7/BA.5 breakthrough cases were enrolled into this study. The serum WT-S-IgG and BA.5-S-IgG were detected by indirect ELISA, and the serum-specific IgG antibody levels of different populations were compared. The application value of the two antibody titers and the ratio of the two antibodies in identifying Omicron BA.5 epidemic strain infection were explored by the ROC curve, aiming to provide technical support for pathogen diagnosis.Results:The antibody titers of WT-S-IgG and BA.5-S-IgG in the breakthrough cases were higher than those in the naturally infected population and the healthy population ( P<0.05). The area under the curve (AUC) of WT-S-IgG and BA.5-S-IgG in identifying epidemic Omicron BA.5 strain infection was 0.947 and 0.961, respectively. The AUC of BA.5-S-IgG and WT-S-IgG antibody titer ratio was 0.873. When the antibody titer ratio was 0.855, the sensitivity and specificity were 80.00% and 90.00%, respectively. According to the interval since the last infection, the AUC of the ratio of BA.5-S-IgG to WT-S-IgG antibody titer to identify the infection of epidemic strains less than 30 days and more than 30 days was 0.887 and 0.863, respectively, and the sensitivity and specificity were both above 80%. Conclusion:Both BA.5-S-IgG and WT-S-IgG, as well as the combination of these two antibodies, are of high value in the identification of epidemic strains.

Objective:Adverse cardiovascular events are the leading cause of death in peritoneal dialysis patients.Identifying indicators that can predict adverse cardiovascular events in these patients is crucial for prognosis.This study aims to assess the value of dual-specificity phosphatase 6(DUSP6)in peripheral blood mononuclear cells as a predictor of adverse cardiovascular events after peritoneal dialysis in diabetic nephropathy patients. Methods:A total of 124 diabetic nephropathy patients underwent peritoneal dialysis treatment at the Department of Nephrology of the First Affiliated Hospital of Hebei North University from June to September 2022 were selected as study subjects.The levels of DUSP6 in peripheral blood mononuclear cells were determined using Western blotting.Patients were categorized into high-level and low-level DUSP6 groups based on the median DUSP6 level.Differences in body mass index,serum albumin,high-sensitivity C-reactive protein,and dialysis duration were compared between the 2 groups.Pearson,Spearman,and multiple linear regression analyses were performed to examine factors related to DUSP6.Patients were followed up to monitor the occurrence of adverse cardiovascular events,and risk factors for adverse cardiovascular events after peritoneal dialysis were analyzed using Kaplan-Meier and Cox regression. Results:By the end of the follow-up,33(26.61%)patients had experienced at least one adverse cardiovascular event.The high-level DUSP6 group had higher body mass index,longer dialysis duration,and higher high-sensitivity C-reactive protein,but lower serum albumin levels compared to the low-level DUSP6 group(all P<0.05).DUSP6 was negatively correlated with serum albumin levels(r=-0.271,P=0.002)and positively correlated with dialysis duration(rs=0.406,P<0.001)and high-sensitivity C-reactive protein(rs=0.367,P<0.001).Multiple linear regression analysis revealed that dialysis duration and high-sensitivity C-reactive protein were independently correlated with DUSP6 levels(both P<0.05).The cumulative incidence of adverse cardiovascular events was higher in the high-level DUSP6 group than in the low-level DUSP6 group(46.67%vs 7.81%,P<0.001).Cox regression analysis indicated that low serum albumin levels(HR=0.836,95%CI 0.778 to 0.899),high high-sensitivity C-reactive protein(HR=1.409,95%CI 1.208 to 1.644),and high DUSP6(HR=6.631,95%CI 2.352 to 18.693)were independent risk factors for adverse cardiovascular events in peritoneal dialysis patients. Conclusion:Dialysis duration and high-sensitivity C-reactive protein are independently associated with DUSP6 levels in peripheral blood mononuclear cells of diabetic nephropathy patients undergoing peritoneal dialysis.High DUSP6 levels indicate a higher risk of adverse cardiovascular events.

Objective:To explore the application of COVID-19-specific IgG antibody in identifying epidemic Omicron BA.5 strain infection.Method:Omicron BF.7/BA.5 naturally infected population, healthy population vaccinated with the COVID-19 vaccine, and Omicron BF.7/BA.5 breakthrough cases were enrolled into this study. The serum WT-S-IgG and BA.5-S-IgG were detected by indirect ELISA, and the serum-specific IgG antibody levels of different populations were compared. The application value of the two antibody titers and the ratio of the two antibodies in identifying Omicron BA.5 epidemic strain infection were explored by the ROC curve, aiming to provide technical support for pathogen diagnosis.Results:The antibody titers of WT-S-IgG and BA.5-S-IgG in the breakthrough cases were higher than those in the naturally infected population and the healthy population ( P<0.05). The area under the curve (AUC) of WT-S-IgG and BA.5-S-IgG in identifying epidemic Omicron BA.5 strain infection was 0.947 and 0.961, respectively. The AUC of BA.5-S-IgG and WT-S-IgG antibody titer ratio was 0.873. When the antibody titer ratio was 0.855, the sensitivity and specificity were 80.00% and 90.00%, respectively. According to the interval since the last infection, the AUC of the ratio of BA.5-S-IgG to WT-S-IgG antibody titer to identify the infection of epidemic strains less than 30 days and more than 30 days was 0.887 and 0.863, respectively, and the sensitivity and specificity were both above 80%. Conclusion:Both BA.5-S-IgG and WT-S-IgG, as well as the combination of these two antibodies, are of high value in the identification of epidemic strains.

Objective:To investigate the effect of adjusting density exposure steps on image quality and radiation dose in digital mammography.Methods:Using the automatic exposure control (AEC) mode of the digital mammography machine, five different gland thicknesses of 4.3, 5.3, 6.3, 7.3, and 8.3 cm were simulated by attaching 0, 1, 2, 3, and 4 PMMA plexiglass plates under the RMI-156 modal body, and the density exposure steps were adjusted to -3, -2, -1, 0, 1, 2, 3, and 4 for each thickness. The target/filter combination, tube voltage, tube current, incident body surface dose (ESD), incident surface air kerma (ESAK), half-value layer (HVL) and the average glandular dose displayed by the device (displayed AGD) were recorded at each step and thickness, and the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), figure of merit (FOM) and the calculated average glandular dose (calculated AGD) were calculated. Then, the display effects of simulated fibers, simulated calcifications and simulated masses within the modal body were scored subjectively, and the changes in image quality and radiation dose at different steps were analyzed, and the relationships between ESD and ESAK, displayed AGD and calculated AGD, and displayed AGD/ESD and calculated AGD/ESAK were analyzed. A linear fit was used for the steps with SNR, CNR, and FOM, and an exponential function curve fit was used for the steps with mAs, ESAK, and calculated AGD. The differences between ESD and ESAK, displayed AGD and calculated AGD, and displayed AGD/ESD and calculated AGD/ESAK were analyzed by paired-samples t test. Results:The CNR and SNR of mammographic images rose and fell by about 8% with each increase or decrease of one step. The scores of image simulated fibers, simulated calcifications, and simulated masses showed an overall upward trend with increasing steps, but there were still cases where the scores decreased with increasing grades. FOM varied from 97% to 104% at each grade with little variability. ESD, ESAK, displayed AGD, and calculated AGD, which could measure radiation dose, showed an exponential trend of increasing function with increasing steps, with a variation of about 63% to 165%. There were statistically significant differences ( t=-9.61, P=0.001) between ESD (15.14±10.08) and ESAK (16.66±11.07). However, there were no statistically significant differences ( t=1.20, P=0.240) between displayed AGD and calculated AGD, which were 3.66±2.18 and 3.61±1.99, respectively. Conclusions:The adjustment of density exposure steps can make the image quality change linearly and the radiation dose change exponentially with increasing speed, and the mode and magnitude of the adjustment are appropriately stable with high application value.

Objective To prepare specific mouse monoclonal antibody (mAb) against human adenovirus type 55 Hexon protein (HAdV55 Hexon). Methods The Hexon genes of HAdV55, 3, 4, 7, 16 and 21 were chemically synthesized as templates for PCR amplification. The prokaryotic expression plasmids pET28a-HAdV55 Hexon and eukaryotic expression plasmids pCAGGS-HAdV3, 4, 7, 16, 21 and 55 Hexon were constructed respectively. The pET28a-HAdV55 Hexon plasmid was transformed into E. coli competent cell BL21 (DE3) and was induced by IPTG. After the purified inclusion body was denatured and renatured, Hexon55 protein was purified by tangential flow filtration system. pCAGGS-HAdV55 Hexon was used to immunize BALB/c mice by cupping, and HAdV55 Hexon protein was used to booster immunization. The anti-HAdV55 Hexon mAb was prepared by hybridoma technique and the titer and subclass were determined. The specificity of antibody was identified by Western blot using HEK293T cells transfected with pCAGGS-HAdV55 Hexon and by immunofluorescence assay (IFA) using BHK cells transfected with pCAGGS-HAdV55 Hexon. Both clones with high titer were selected, and the cross-reactivity of pCAGGS-HAdV3, 4, 7, 16, 21 and 55 Hexon transfected cells were analyzed by Western blot analysis and IFA. Results PET28a-HAdV55 Hexon and pCAGGS-HAdV55 Hexon, 3, 4, 7, 16 and 21 expression plasmids were successfully constructed. BL21 transformed with pET28a-HAdV55 Hexon was induced by IPTG. The HAdV55 Hexon protein was mainly expressed in the form of inclusion body. After denaturation and renaturation, the purified HAdV55 Hexon protein was obtained by ultrafiltration. Six hybridoma cell lines secreting HAdV55 Hexon mAb were obtained. The antibody subclass analysis showed that 2 strains were IgG2a subtypes and 4 strains were IgG2b. Two specific HAdV55 Hexon antibodies with high titer were obtained, and there was no cross-reactivity with HAdV3, 4, 7, 16, 21 Hexon. Conclusion The specific mice mAb against HAdV55 Hexon provides an experimental basis for establishing its antigen detection method.
Animals ; Mice ; Humans ; Adenoviruses, Human/genetics* ; Escherichia coli/genetics* ; HEK293 Cells ; Isopropyl Thiogalactoside ; Blotting, Western ; Immunoglobulin G ; Antibodies, Monoclonal ; Antibody Specificity ; Mice, Inbred BALB C

High Altitude Military Hygiene is the professional core course of high-altitude medicine, which is significant to the cultivation of military medical talents urgently needed by plateau troops. Under the background of "golden course" construction and army curriculum reform, aiming at the problems such as outdated content of course materials, single teaching mode and insufficient capacity of practical courses, we actively explored the effective path of "golden course" construction, including the renovation of the curriculum-construction concept, the optimization and reorganization of the teaching content, the expansion of case teaching and equipment teaching methods, and the implementation of curriculum ideological and political education and examination reforms. The reform has further improved the learning effect of students and the level of curriculum construction, and also provided beneficial reference for the construction of similar courses in military colleges and universities.

Objective:To observe the effects of problem-based learning (PBL) and case-based learning (CBL) combined with self-media platform in clinical probation teaching of gastroenterology.Methods:From July 2019 to June 2020, 60 students in the Department of Gastroenterology of the Army Characteristic Medical Center of PLA were assigned to the traditional teaching group (control group, n=30) and the PBL and CBL combined with the self-media platform teaching group (experimental group, n=30). After the teaching, theoretical examination, practical assessment, and questionnaires were used to evaluate the effects of the two teaching methods. SPSS 23.0 was used to perform the t-test. Results:The comprehensive scores of students in the experimental group, including theoretical examination score (86.60±1.17) and practical assessment score (86.40±0.83), were significantly higher than those in the control group [(81.70±0.98), (82.00±1.18), P<0.001]. The questionnaire survey showed that the experimental group was superior to the traditional teaching group in terms of self-study and data access ability, students' self-confidence, and satisfaction with teaching ( P<0.001). Conclusion:PBL and CBL combined with self-media platform uses actual medical records to guide students to discuss, analyze, and summarize clinical issues. Combined with flexible learning on the self-media platform, this method breaks through the limitations of traditional teaching models and improves teaching quality and learning satisfaction. Therefore, this method can be promoted in clinical probation teaching of gastroenterology.

Objective:To evaluate the detection ability of two kinds of high-throughput method to determine neutralizing antibodies based on a microneutralization test (MNT).Methods:Serum samples were collected from the early phase and follow-up period (117 samples in total) for neutralizing antibody testing. They were tested using MNT, pseudovirus neutralization assay (PBNA), competitive inhibition assay (including enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassay (CLIA)) to evaluate the correlation coefficients and threshold values for the effectiveness of these high-throughput neutralizing antibody assays.Results:The correlation coefficients for PBNA, ELISA, and CLIA relative to MNT were 0.760, 0.778, and 0.725, respectively, for individuals infected with 2019-nCoV. The area under the ROC curve was 0.901 for a cutoff value of 50 for the PBNA assay, 0.934 for a cutoff value of 1∶8 for the ELISA assay and 0.838 for a cutoff value of 1.28AU/ml for the CLIA assay when the threshold value for the microneutralization test was taken as 1: 10 (less than 1: 10 is considered negative).Conclusions:The high-throughput method for the detection of COVID-19 neutralizing antibodies are scientific and feasible, and provide an important technical tool for the regular prevention and control of the epidemic.

Objective:To explore the role of bedside cardiopulmonary ultrasound in the evaluation of non-invasive positive pressure ventilation (NPPV) in patients with cardiaogenic pulmonary edema in emergency department.Methods:The clinical data and characteristics of bedside rapid cardiopulmonary ultrasound in patients withcardiaogenic pulmonary edema treated with NPPV in the emergency department were retrospectively analyzed. The following ultrasound parameters, including lung ultrasound score, the ratio of lung consolidation, diameter of inferior vena cava, left ventricular ejection fraction (LVEF), the mitral annular systolic displacement (MAPSE) and tricuspid annular systolic displacement (TAPSE), the peak Doppler velocities of the early diastolic mitral (E), the tissue velocity imaging of left ventricular and right ventricular (Sm), the tissue Doppler of the early diastolic velocity of the mitral annulus (e’), the average E/e’ ratio of left ventricular, systolic pulmonary artery pressure (SPAP) and the ratio of atrial fibrillation,, were determined. All of the parameters combined with clinical parameters were compared between the non-invasive ventilation success group and non-invasive ventilation failure group. Univariate and multivariate logistic regression analysis were used to screen out the risk factors by taking the failure of NPPV treatment as the dependent variable. The area under the receiver operating characteristic (ROC) curve was used to analyze the predictive value of the indicators above.Results:A total of 66 patients, included 44 (66.%) of NPPV success and 22 (33.3%) of NPPV failure revealed by bedside cardiopulmonary ultrasound. In comparison with the NPPV success group, the lung ultrasound score, ratio of lung consolidation, E/e’ of LV , SPAP, the ratio of right ventricular dysfunction, the ratio of atrial fibrillation and the level of Ccr were significantly evaluated, but the Sm of right ventricular and PaO2/FiO2 were significantly lower in the NPPV failure group (all P< 0.05). There were no differences in LVEF, MAPSE, TPASE, diameter of inferior vena cava and the Sm of left ventricular between groups (all P> 0.05). Multivariate logistic regression analysis showed that lung ultrasound score, E/e’ and SPAP were independent predictors of NPPV failure in patients with cardiaogenic pulmonary edema. The AUCs of lung ultrasound score, E/e’ of LV and SPAP for predicting NPPV failure was 0.802, 0.783 and 0.852, respectively. . Conclusions:The lung ultrasound score, right ventricular diastolic function and SPAP evaluated by bedside cardiopulmonary ultrasound could provide predictive values for the non-invasive positive ventilation failure in patients with cardiaogenic pulmonary edema.

Objective: To investigate the characteristics and prognostic value of peripheral blood T lymphocyte subsets in patients with severe influenza. Methods: This was a single-center cross-sectional study in influenza patients admitted to Peking Union Medical College Hospital from August 2017 to April 2018. Peripheral blood lymphocyte subsets were detected by flow cytometry in both patients and 108 healthy controls. Influenza patients were divided into mild group and severe group. Severe patients were further classified into alive and fatal subgroups. Results: A total of 42 influenza patients were recruited in this study, including 24 severe cases (6 deaths). The remaining 18 cases were mild. The peripheral blood lymphocyte counts and lymphocyte subset counts (B, NK, CD4⁺T, CD8⁺T) in either mild patients[795 (571,1 007), 43 (23,144), 70 (47,135), 330 (256,457), 226 (148,366) cells/μl respectively] or severe patients[661 (474,1 151),92 (52,139), 54 (34,134), 373 (235,555), 180 (105,310) cells/μl respectively] were both significantly lower than those of healthy controls [1 963 (1 603,2 394),179 (119,239), 356 (231,496), 663 (531,824), 481 (341,693) cells/μl respectively]. Meanwhile, the T cells and CD8⁺T counts in fatal patients [370 (260,537) cells/μl and 87 (74,105) cells/μl] were significantly lower than those in severe and alive patients [722 (390,990) cells/μl and 222 (154,404) cells/μl]. CD8⁺HLA-DR/CD8⁺and CD8⁺CD38⁺/CD8⁺T cell activating subgroups in mild cases[(53.7±19.2)% and 74.8% (64.1%,83.7%) respectively] were significantly higher than those in severe cases[(38.5±21.7)% and 53.3% (45.3%,67.2%) respectively].Moreover,CD8⁺HLA-DR/CD8⁺count in severe and alive group was higher than that in fatal group [(46.1±19.1)% vs. (18.2±14.6)%, P<0.01]. Logistic regression analysis showed that CD8⁺T cell count (OR=0.952, 95%CI 0.910-0.997, P=0.035) and CD8⁺HLA-DR/CD8⁺T (OR=0.916, 95%CI 0.850-0.987, P=0.022) were both negatively correlated with mortality.Peripheral blood lymphocyte counts in mild cases rapidly decreased within 1 day after diagnosis, and returned to the basic level one week later. Conclusions All peripheral blood lymphocyte subsets (T,B,NK) in patients with influenza are significantly reduced. These findings are consistent with the immunological characteristics of respiratory viral infections, in which peripheral lymphocytes (especially T cells) migrate to respiratory tract in the early stage and circulate to the peripheral blood after recovery. The activated CD8⁺T cell counts in peripheral blood are negatively correlated with the severity of disease, which could be considered as a prognostic indicator of severe influenza.