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.

Background::Although overnight fasting is recommended prior to endoscopic retrograde cholangiopancreatography (ERCP), the benefits and safety of high-carbohydrate fluid diet (CFD) intake 2 h before ERCP remain unclear. This study aimed to analyze whether high-CFD intake 2 h before ERCP can be safe and accelerate patients’ recovery.Methods::This prospective, multicenter, randomized controlled trial involved 15 tertiary ERCP centers. A total of 1330 patients were randomized into CFD group ( n = 665) and fasting group ( n = 665). The CFD group received 400 mL of maltodextrin orally 2 h before ERCP, while the control group abstained from food/water overnight (>6 h) before ERCP. All ERCP procedures were performed using deep sedation with intravenous propofol. The investigators were blinded but not the patients. The primary outcomes included postoperative fatigue and abdominal pain score, and the secondary outcomes included complications and changes in metabolic indicators. The outcomes were analyzed according to a modified intention-to-treat principle. Results::The post-ERCP fatigue scores were significantly lower at 4 h (4.1 ± 2.6 vs. 4.8 ± 2.8, t = 4.23, P <0.001) and 20 h (2.4 ± 2.1 vs. 3.4 ± 2.4, t= 7.94, P <0.001) in the CFD group, with least-squares mean differences of 0.48 (95% confidence interval [CI]: 0.26–0.71, P <0.001) and 0.76 (95% CI: 0.57–0.95, P <0.001), respectively. The 4-h pain scores (2.1 ± 1.7 vs. 2.2 ± 1.7, t = 2.60, P = 0.009, with a least-squares mean difference of 0.21 [95% CI: 0.05–0.37]) and positive urine ketone levels (7.7% [39/509] vs. 15.4% [82/533], χ2 = 15.13, P <0.001) were lower in the CFD group. The CFD group had significantly less cholangitis (2.1% [13/634] vs. 4.0% [26/658], χ2 = 3.99, P = 0.046) but not pancreatitis (5.5% [35/634] vs. 6.5% [43/658], χ2 = 0.59, P = 0.444). Subgroup analysis revealed that CFD reduced the incidence of complications in patients with native papilla (odds ratio [OR]: 0.61, 95% CI: 0.39–0.95, P = 0.028) in the multivariable models. Conclusion::Ingesting 400 mL of CFD 2 h before ERCP is safe, with a reduction in post-ERCP fatigue, abdominal pain, and cholangitis during recovery.Trail Registration::ClinicalTrials.gov, No. NCT03075280.

Aim To preliminarily evaluate the effects of hypobaric hypoxia on organism damage in rats with post-traumatic stress disorder(PTSD),with a view to laying a foundation for drug research in plateau PTSD.Methods The rats were randomly divided into four groups,namely,the control(Control)group,the sin-gle-prolonged stress(SPS)group,the hypobaric hy-poxia(HH)group and the single-prolonged stress combined with hypobaric hypoxia(SPS+HH)group.The PTSD model was firstly constructed using the SPS method for rats in the SPS and SPS+HH groups.On the second day,rats in the HH group and SPS+HH group were placed in a low-pressure hypoxia chamber at a simulated altitude of 6000 m for 14 days.General condition,behavior,blood tests,and histomorphology were examined in order to evaluate the damage caused by low pressure hypoxia in PTSD rats.Results The body mass of rats in the SPS+HH group was signifi-cantly reduced;the feces were partly hard and lumpy,and some of them were seen to have high viscosity.Anxiety-like and depression-like behaviors were ob-served in all groups except in the control group,in which hypobaric hypoxia aggravated the behavioral ab-normalities in SPS rats.Rats in both the SPS and SPS+HH groups had coagulation dysfunction and abnor-mally increased blood viscosity,which was significantly abnormal in the SPS+HH group;erythrocytes,hemo-globin,and erythrocyte specific volume in whole blood of rats in the SPS+HH group were significantly in-creased compared with those of rats in the SPS group;and serum TP,LDH and GLU levels were abnormal in rats in the SPS+HH group.Dilated and congested blood vessels were seen in hippocampal tissue,conges-ted central veins were seen in hepatic tissue,and dilat-ed and congested liver sinusoids with mild granuloma-tous degeneration of hepatocytes were seen in rats of the SPS+HH group.Conclusion Hypobaric hypoxia exacerbates depression-like and anxiety-like behaviors in PTSD rats,as well as hematological indices and his-tomorphometric abnormalities in PTSD rats.

Aim To observe the effects of Wenfei Jiangzhuo formula(WFJZF)on rats with vascular de-mentia and investigate its possible mechanism of ac-tion.Methods Thirty-six healthy male SD rats were randomly divided into the sham group,model group,donepezil group,and low-dose,medium-dose and high-dose groups of Wenfei Jiangzhuo formula,with six rats per group.Except for the sham group,the other groups were prepared as VaD models,and each group was gavaged with the corresponding drugs after suc-cessful modeling,and tests were performed after three weeks of treatment.Behavioral,hippocampal CA1 area morphology,neural dendrites and mitochondrial chan-ges were observed in all groups of rats,and phospho-glycerate mutase 5(PGAM5),dynamics-related pro-teins1(Drp1),opticatrophyprotein-1(OPA1),and other proteins were detected in each group.Results Compared with the sham group,rats in the model group and each intervention group had prolonged es-cape latency(P＜0.05),a shorter number of travers-als across the platforms(P＜0.05),a sparse morphol-ogy of hippocampal neurons,a reduction in the number of secondary dendritic spines,and a rupture of the out-er membrane of the mitochondria;the expression of the PGAM5 and Drp1 proteins in hippocampal tissues was elevated(P＜0.05),and the expression of the OPA1 and Mfn1/2 protein expression decreased(P＜0.05);compared with the model group,donepezil group and Wenfei Jiangzhuo formula high-dose group of rats had shorter evasion latency(P＜0.05),increased number of times to traverse the platform(P＜0.05),increased number of hippocampal neurons,tightly packed,more secondary dendritic structures,and reduced mitochon-drial damage;the expression of PGAM5 and Drp1 pro-teins was reduced(P＜0.05),and the expression of OPA1 and Mfn1/2 proteins was elevated(P＜0.05).Conclusions Wenfei Jiangzhuo formula can regulate the PGAM5-Drp1 signaling axis to improve the balance of mitochondrial homeostasis,thus improving the cog-nitive condition of the brain and exerting cerebroprotec-tive effects.

Objective To explore mechanism of piracetam for the treatment of spinal cord injury in rats through mitogen-activated protein kinase(MAPK)pathway.Methods Fifty-four healthy 6-week-old SD female rats with body weight of 80 to 100 g were divided into sham operation group,spinal cord injury group and piracetam group by random number table method,with 18 rats in each group.Spinal cord injury model was established in spinal cord injury group and piracetam group using percussion apparatus,while sham operation group did not damage spinal cord.Piracetam group was injected with pirac-etam injection through tail vein according to 5 ml·kg-1 standard,once a day for 3 days;the other two groups were injected with normal saline at the same dose,the same frequency and the same duration.The rats were sacrificed at 1,3,and 7 days after surgery,and changes of Basso,Beattie and Bresnahan(BBB)locomotor rating scale was observed and compared.Enzyme-linked immunosorbent assay(ELISA)was used to detect spinal cord inflammatory factors,such as interleukin-6(IL-6),in-terleukin-10(IL-10),interleukin-1β(interleukin-1β),necrosis factor-α(IL-1β)and tumor necrosis factor-α(TNF-α);HE staining was used to observe morphological changes of rats with spinal cord injury,and immunohistochemistry was used to observe expression level of aquaporin 4(AQP4).The activation of MAPK signaling pathway in spinal cord of rats after spinal cord injury was observed by western blotting(WB).Results BBB scores of sham operation group on 1,3 and 7 day were 21 points.In spinal cord injury group,the scores were(1±1),(4±1)and(7±2);piracetam group was(1±1),(5±1),(9±2),re-spectively;the difference between spinal cord injury group and sham operation group was statistically significant(P＜0.05).HE staining showed that no abnormality was found in sham operation group.In spinal cord injury group,bleeding and degeneration of spinal cord tissue appeared at 1 day after operation;flaky necrotic areas were appeared in spinal cord at 3 days after surgery,and spinal cord tissue began to slowly repair at 7 days after surgery.In piracetam group,the bleeding area was less than that of spinal cord injury group at 1 day after surgery;at 3 days after operation,the necrotic area was reduced and the range of nuclear disappearance was reduced;and the spinal cord began to recover slowly at 7 days after surgery.AQP4 staining of spinal cord of rats in sham operation group was weak at 1,3 and 7 days after modeling,AQP4 staining was deepened and area increased in spinal cord injury group,AQP4 staining of piracetam group was lighter than that of spinal cord injury group,and the positive cells were slightly increased and the staining was slightly darker than that of sham operation group.At 1,3 and 7 days,the level of IL-6,IL-10,IL-1β and TNF-α in spinal cord injury group were higher than those in sham operation group and piracetam group(P＜0.05).Compared with spinal cord injury group,the area of spinal cord bleeding and necrosis were de-creased by HE staining in piracetam group,and AQP4 staining was decreased by immunohistochemistry.WB results showed that P-ERK,P-JNK and P-P38 levels in spinal cord injury group at 3 days were higher than those in sham operation group and piracetam group(P＜0.05).Conclusion Piracetam not only showed significant effect in promoting motor function recovery after spinal cord injury,but also showed positive therapeutic potential in reducing lesion area,regulating AQP4 expression to reduce edema,and reducing inflammatory response by regulating MAPK signaling pathway.

Objective To investigate the effect of artemisinin(ART)on the malignant biological behavior of colorectal cancer(CRC)cells stimulated by glucose and its mechanism.Methods The concentration gradients of 0,5,10,20,40 and 60 μmol/L of ART were used to treat the human colorectal cancer cell line SW480,and then the cell viability was detected by CCK-8.Cell apoptosis was detected by flow cytometry.Transwell was used to detect the cell migration and invasion.Western blot was used to detect the apoptosis,epithelial-mesenchymal transition(EMT)and Janus kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3)related proteins expression.Results Compared with the 0 μmol/L of ART,the viability of SW480 cells decreased under 5,10,20,40,60 μmol/L of ART treatment(P<0.05),and IC50 was 36.91 μmol/L.Therefore,the cells treated with 10,20 and 40 μmol/L of ART were as the low-dose,medium-dose and high-dose ART groups,the cells treated with 0 μmol/L of ART were as the control group,and the cells treated with 40 μmol/L of ART and 10 μmol/L of Coumermycin A1 were as the Coumermycin A1 group.Compared with the control group,the cell scratch wound healing rate,invasion ability,and expression levels of Bcl-2,N-cadherin,Vimentin,p-JAK2,and p-STAT3 in the low-dose ART group,the medium-dose ART group,and the high-dose ART group decreased obviously(P<0.05),while the apoptosis rate,and expression levels of Bax,Caspase-3 and E-cadherin increased(P<0.05).Compared with the high-dose ART group,the cell scratch wound healing rate,invasion ability,and expression levels of Bcl-2,N-cadherin,Vimentin,p-JAK2,and p-STAT3 in the Coumermycin A1 group increased obviously(P<0.05),while the apoptosis rate,and expression levels of Bax,Caspase-3 and E-cadherin decreased(P<0.05).Conclusion ART may inhibit the viability,migration,invasion and EMT of glucose-stimulated CRC cells and promote apoptosis by inhibiting the JAK2/STAT3 signaling pathway.

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.