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 study the effects of different peri-ods of hypoxia on gastrointestinal stress in mice by sim-ulating hypoxia environment at high altitude in a low-pressure oxygen chamber.Methods The normal con-trol group and the model group for 1,3 and 5 days were set up according to different periods of hypobaric hypoxia.The intestinal propulsion rate,visceral sensi-tivity and pathological damage of gastrointestinal tract were detected after hypobaric hypoxia treatment.The contents of IL-1 β,IL-6 and TNF-α in gastrointestinal tract and the contents of gastrointestinal hormone,di-amine oxidase and D-lactic acid were detected by en-zyme-linked immunosorbent assay(ELISA).The ex-pressions of tight-junction protein and tight junction in-jury pathway protein in intestinal tissues were detected by Western blot.Results Compared with the control group,the intestinal propulsion rate of the model group was accelerated,and the intestinal sensitivity in-creased.The expression of intestinal mucosal injury markers increased.Gastrointestinal motility inhibiting hormone decreased and gastrointestinal motility promo-ting hormone increased.The expression of tight junc-tion proteins ZO-1,claudin-1,occludin and VASP of tight junction injury-related pathway decreased,while the expression of NF-κB,HIF-1α and VEGF in tight junction injury-related pathway increased.The expres-sions of IL-1 β,IL-6 and TNF-α in gastrointestinal tis-sue increased.The content of pepsin in gastric tissue increased.The injury of gastrointestinal tissue was less in the 1-day group,and more serious in the 3-day and 5-day groups.Conclusions Stress injury occurs in the gastrointestinal tract of mice at different time points in hypoxia and hypoxia environment,and the gastroin-testinal function injury is more serious after three days of exposure,which may be related to the activation of NF-κB/HIF-1α/VEGF/VASP pathway.

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 correlation between the expression of Toll-like receptor 4(TLR4)and chitosanase 3-like protein 1(CHI3L1)in colon cancer tissue and the prognosis of patients after radical surgery.Methods A total of 152 patients who underwent radical colon cancer surgery in our hospital from January 2017 to May 2018 were collected and divided into the good prognosis group(n=97)and the poor prognosis group(n=47)according to the 5-year survival status after surgery.Immunohistochemical staining was applied to detect the expression levels of TLR4 and CHI3L1 in colon cancer tissues and adjacent tissues;the correlation between the expression of TLR4 and CHI3L1 in colon cancer tissue and the prognosis of patients was analyzed,and the influencing factors for prognosis of colon cancer patients were analyzed.Results The positive expression rates of TLR4 and CHI3L1 in colon cancer tissues were obviously higher than those in adjacent tissues(P<0.05).The expression of TLR4 in colon cancer tissue was related to the degree of tumor differentiation,clinical staging,and lymph node metastasis of colon cancer patients(P<0.05),the expression of CHI3L1 was related to the tumor diameter,degree of tumor differentiation,clinical staging,and lymph node metastasis of colon cancer patients(P<0.05).Compared with the good prognosis group,the poor prognosis group had higher proportions of patients with poorly differentiated tumor,clinical stageⅢ,lymph node metastasis,and positive expression of TLR4 and CHI3L1(P<0.05).The 5-year survival rate of patient with TLR4 positive expression was 60.38%,which was lower than that of 86.84% of patients with TLR4 negative expression(χ2=9.104,P<0.05);the 5-year survival rate of patients with CHI3L1 positive expression was 58.06%,which was lower than that of 84.31% of patients with CHI3L1 negative expression(χ2=10.935,P<0.05).The positive expression of TLR4 and CHI3L1,poorly differentiated tumor,clinical stage Ⅲ,and lymph node metastasis were the independent risk factors for the prognosis of colon cancer patients(P<0.05).Conclusion TLR4 and CHI3L1 are related to the occurrence and clinicopathological features of colon cancer,and the positive expression of TLR4 and CHI3L1 in colon cancer tissues is not conducive to the prognosis of patients,so both of them are expected to become clinical treatment targets.

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.