ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

Objective:To analyze the methylation characteristics of the lymphocyte-specific protein-tyrosine kinase (LCK) promoter region in the peripheral blood circulation of rheumatoid arthritis (RA) patients and its correlation with clinical indicators.Methods:Targeted methylation sequencing was used to compare the methylation levels of 7 CpG sites in the LCK promoter region in the peripheral blood of RA patients with healthy controls (HC) and osteoarthritis (OA) patients. Correlation analysis and ROC curve construction were performed with clinical information.Results:Non-parametric tests revealed that compared with HC [0.53(0.50, 0.57)] and OA patients [0.59(0.54, 0.62), H=47.17, P<0.001], RA patients [0.63(0.59, 0.68)] exhibited an overall increase in methylation levels. Simultaneously, when compared with the HC group [0.38(0.35, 0.41), 0.59(0.55, 0.63), 0.60(0.55, 0.64), 0.59(0.55, 0.63), 0.58(0.53, 0.62), 0.45(0.43, 0.49), 0.57(0.54, 0.61)], the RA group [0.46(0.42, 0.49), 0.70(0.65, 0.75), 0.70(0.66, 0.76), 0.70(0.65, 0.75), 0.69(0.64, 0.74), 0.55(0.51, 0.59), 0.68(0.63, 0.73)] showed a significant elevation in methylation levels at CpG sites cg05350315_60, cg05350315_80, cg05350315_95, cg05350315_101, cg05350315_104, cg05350315_128, and cg05350315_142, with statistically significant differences ( Z=-5.63, -5.89, -5.91, -5.89, -5.98, -5.95, -5.95, all P<0.001). Compared with the OA group [0.65(0.59, 0.69), 0.65(0.60, 0.69), 0.64(0.58, 0.68), 0.50(0.45, 0.54), 0.63(0.58, 0.67)], the RA group [0.70(0.66, 0.76), 0.70(0.65, 0.75), 0.69(0.64, 0.74), 0.55(0.51, 0.59), 0.68(0.63, 0.73)] exhibited a significant increase in methylation levels at CpG sites cg05350315_95, cg05350315_101, cg05350315_104, cg05350315_128, and cg05350315_142, with statistically significant differences ( Z=-3.56, -3.52, -3.60, -3.67, -3.62; P=0.036, 0.042, 0.031, 0.030, 0.030). Furthermore, Pearson correlation coefficient analysis revealed a positive correlation between the overall methylation level in this region and C-reactive protein (CRP) ( r=0.19, P=0.004) and erythrocyte sedimentation rate ( r=0.14, P=0.035). The overall methylation level of the LCK promoter region in the CRP (low) group [0.63 (0.58, 0.68)] was higher than that in the CRP (high) group [0.65(0.61, 0.70)], with statistically significant differences ( Z=2.60, P=0.009). Finally, by constru-cting a ROC curve, the discriminatory efficacy of peripheral blood LCK promoter region methylation levels for identifying RA patients, especially seronegative RA patients, from HC and OA groups was validated, with an AUC value of 0.78 (95% CI: 0.63, 0.93). Conclusion:This study provides insights into the methylation status and methylation haplotype patterns of the LCK promoter region in the peripheral blood of RA patients. The overall methylation level in this region is positively correlated with the level of inflammation and can be used to differentiate seronegative RA patients from the HC and OA patients.

Objective To observe the clinical efficacy of Modified Tongxie Yaofang(Important Formula for Relieving Diarrhea with Pain)in the treatment of patients with diarrhea-predominant irritable bowel syndrome(IBS-D)with liver-depression and spleen-deficiency syndrome.Methods Sixty patients with IBS-D of liver depression and spleen deficiency type were randomly divided into treatment group and control group,30 patients in each group.The patients in the treatment group were given modified Tongxie Yaofang,and the patients in the control group were given Pivacurium Bromide Tablets(Dicetel).Both groups were treated for a 4-week course of treatment.The changes of traditional Chinese medicine(TCM)syndrome scores,irritable bowel syndrome quality of life(IBS-QOL)scores,Hamilton Anxiety Scale(HAMA)scores of the two groups were observed before and after the treatment.Moreover,the efficacy for overall symptomatic improvement in the two groups was evaluated according to the grading of irritable bowel syndrome symptom severity score(IBS-SSS),and the efficacy for improving single symptom such as abdominal pain and diarrhea as well as the relapse after 4 weeks of drug cessation in the two groups were compared.Results(1)After 4 weeks of treatment,the total effective rate for overall symptomatic improvement in the treatment group was 83.33%(25/30),and that in the control group was 43.33%(13/30).The intergroup comparison(tested by chi-square test)showed that the efficacy for overall symptomatic improvement in the treatment group was significantly superior to that in the control group(P＜0.01).(2)After 4 weeks of treatment,the total effective rate for improving single symptom of abdominal pain and diarrhea in the treatment group was 80.00%(24/30),90.00%(27/30),and that in the control group was 43.33%(13/30),46.67%(14/30),respectively.The intergroup comparison(tested by chi-square test)showed that the efficacy for improving single symptom of abdominal pain and diarrhea in the treatment group was significantly superior to that in the control group(P＜0.01).(3)After 4 weeks of treatment,the TCM syndrome scores,IBS-QOL scores,and HAMA scores of patients in both groups were significantly decreased compared with those before treatment(P＜0.05 or P＜0.01),and the decrease in the treatment group was significantly superior to that in the control group(P＜0.01).(4)After 4 weeks of drug withdrawal,the recurrence rate of the treatment group was 24.00%(6/25),which was significantly lower than that of the control group(61.54%,8/13),and the difference was statistically significant between the two groups(P＜0.05).Conclusion Modified Tongxie Yaofang exerts certain effect in treating patients with IBS-D of liver depression and spleen deficiency type,and the decoction is effective on decreasing the scores of symptoms of abdominal pain and diarrhea as well as TCM syndrome scores,improving the quality of life of the patients,and alleviating the anxiety status of the patients.

Objective:To investigate the predictive value of the ratio of tricuspid annulus plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) in the progression of heart failure with reduced ejection fraction (HFrEF) patients.Methods:A total of 172 patients with HFrEF in the First Affiliated Hospital of Zhengzhou University from January to December 2022 were prospectively selected. All participants underwent routine echocardiography, the routine cardiac ultrasound parameters, left atrial volume index (LAVi), right ventricular fractional area change (RVFAC) were measured. The ratio of early diastolic velocity E peak of the mitral valve orifice to the early diastolic mean velocity e′ of the mitral valve annulus (E/e′) and TAPSE/PASP were calculated. The online quantitative analysis software of the ultrasound instrument were used to obtain the left ventricular global longitudinal strain (LVGLS), left atrial reservior strain (LASr), left atrial conduit strain (LAScd), left atrial contraction strain (LASct), right ventricular global systolic strain (RVGLS), and right ventricular free wall strain (RVFWS). According to the median of TAPSE/PASP, the patients were divided into TAPSE/PASP≥0.50 mm/mmHg group(group 1, 85 cases) and TAPSE/PASP<0.50 mm/mmHg group(group 2, 87 cases). The endpoint events were recorded. The differences of the above parameters in two groups were compared, the correlation analysis was used to analyze the correlations between myocardial mechanical parameters and TAPSE/PASP. The Kaplan-Merier method was used to draw survival curves, and the Log-rank method was used to compare the differences in survival curves in the two groups. The univariate and multivariate Cox regression models were used to analyze the predictive value of TAPSE/PASP for end-point events.Results:There were no significant differences in age, gender, body mass index, complications and left ventricular end-diastolic volume (LVEDV) between the two groups (all P>0.05). Compared with group 1, patients in group 2 showed a significant decrease in RVFAC and TAPSE (all P<0.05), while the LAVi, left ventricular end-systolic volume (LVESV), right ventricular end-diastolic diameter (RVDd-base), E/e′ and PASP were increased (all P<0.05), the absolute values of LVGLS, LASr, LASct, RVGLS, and RVFWS were significantly decreased (all P<0.05). Correlation analysis showed that LVGLS, LASr, RVGLS, RVFAC and 6-min walking distance were linearly correlated with TAPSE/PASP ( r/ rs=-0.176, 0.181, -0.496, 0.472, 0.421; all P<0.05). The follow-up time was (11.71±1.80) months, and the incidence of death events in group 2 (28.73%) was higher than that in group 1 (10.61%), with a significant difference ( P<0.05). The results of multivariate Cox regression analysis showed that TAPAE/PASP was one of the independent predictive factors for endpoint events in HFrEF patients, with adjusted HR: 0.306, 95% CI=0.141-0.663, P=0.003. Conclusions:TAPSE/PASP can monitor the progression of chronic heart failure and is one of the independent predictive factors, providing a new reference indicator for clinical diagnosis and treatment.

Objective To observe the clinical efficacy of modified Dahuang Fuzi Decoction following the therapy of unblocking bowels for the treatment of acute pancreatitis of pathogenic-cold accumulation and retention type.Methods A total of 78 patients with acute pancreatitis of pathogenic-cold accumulation and retention type were randomly divided into a study group and a control group,39 cases in each group.The control group was treated with conventional western medicine,and the study group was treated with oral use or nasogastric feeding of Dahuang Fuzi Decoction on the basis of treatment for the control group.The course of treatment covered seven days.The two groups were observed in the changes of serum pancreatic enzyme indicators of serum amylase and lipase,inflammatory factors of C-reactive protein(CRP),procalcitonin(PCT),interleukin-6(IL-6)and interleukin-8(IL-8),acute physiology and chronic health evaluation Ⅱ(APACHE Ⅱ)score,and modified CT severity index(MCTSI)score before and after treatment.The time for abdominal pain relief,time for abdominal distension relief,and time for anal defecation were compared between the two groups.After treatment,the clinical efficacy and safety of the two groups were evaluated.Results(1)During the trial,there was one patient falling off separately from the study group and the control group,and 38 patients in each group were eventually included in the efficacy statistics.(2)After seven days of treatment,the total effective rate of the study group was 86.84％(33/38),and that of the control group was 78.95％(30/38).The intergroup comparison(tested by rank sum test)showed that the efficacy of the study group was significantly superior to that of the control group(P＜0.05).(3)After treatment,the serum levels of pancreatic enzyme indicators of amylase and lipase in the two groups were decreased compared with those before treatment(P＜0.05),and the decrease of serum amylase and lipase levels in the study group was significantly superior to that in the control group(P＜0.05).(4)After treatment,the serum levels of inflammatory factors of CRP,PCT,IL-6 and IL-8 in the two groups were decreased compared with those before treatment(P＜0.05),and the decrease of serum CRP,PCT,IL-6 and IL-8 levels in the study group was significantly superior to that in the control group(P＜0.05).(5)After treatment,the APACHE Ⅱ and MCTSI scores of the two groups were decreased compared with those before treatment(P＜0.05),and the decrease of APACHE Ⅱ and MCTSI scores in the study group was significantly superior to that in the control group(P＜0.05).(6)For the time of symptom relief,the time for abdominal pain relief,time for abdominal distension relief,and time for anal defecation in the study group were significantly shortened compared with those in the control group,and the differences were statistically significant(P＜0.05).(7)No obvious adverse reactions occurred in the two groups during the treatment,indicating high safety.Conclusion On the basis of conventional treatment,the use of modified Dahuang Fuzi Decoction following the therapy of unblocking bowels exerts certain efficacy for the treatment of patients with acute pancreatitis of pathogenic-cold accumulation and retention type.The therapy is effective on relieving the symptoms and signs of patients,and decreasing the level of serum pancreatic enzyme indicators and inflammatory factors.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.