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 study the molecular biological mechanism for a case of ABO blood group B subtype, and perform three-dimensional modeling of the mutant enzyme. [Methods] The ABO phenotype was identified by the tube method and microcolumn gel method; the ABO gene of the proband was detected by sequence-specific primer polymerase chain reaction (PCR-SSP), and the exon 6 and 7 of the ABO gene were sequenced and analyzed. Homologous modeling of Bw.03 glycosyltransferase (GT) was carried out by Modeller and analyzed by PyMOL2.5.0 software. [Results] The weakening B antigen was detected in the proband sample by forward typing, and anti-B antibody was detected by reverse typing. PCR-SSP detection showed B, O gene, and the sequencing results showed c.721 C>T mutation in exon 7 of the B gene, resulting in p. Arg 241 Trp. Compared with the wild type, the structure of Bw.03GT was partially changed, and the intermolecular force analysis showed that the original three hydrogen bonds at 241 position disappeared. [Conclusion] Blood group molecular biology examination is helpful for the accurate identification of ambiguous blood group. Homologous modeling more intuitively shows the key site for the weakening of Bw.03 GT activity. The intermolecular force analysis can explain the root cause of enzyme activity weakening.

Objective: To understand the current situation and influencing factors of comorbidity of depressive and anxiety symptoms among middle school students in Chongqing, so as to provide a scientific basis for formulating a comprehensive strategy for the co prevention of multiple diseases among middle school students. Methods: From September to December 2024, 12 327 middle school students were selected from 6 districts and counties in Chongqing by the combination of stratified cluster sampling and convenience sampling method. The current status of depressive and anxiety symptoms was investigated by using the Center for Epidemiological Survey-Depression Scale (CES-D) and the Generalized Anxiety Disorder-7 (GAD-7). The Chi-squared test was used to compare the differences between groups with comorbidity of depressive and anxiety symptoms, multivariate Logistic regression analysis was used to analyze its related factors, and a nomogram prediction model was drawn. Results: The detection rates of depressive symptoms, anxiety symptoms and comorbidity among middle school students in Chongqing were 26.34%, 34.55% and 21.16%, respectively. Among them, the detection rates of the three types of symptoms in girls (29.80%, 40.99%, 25.15%) were all higher than those in boys (23.22%, 28.73%, 17.55%) ( χ 2=68.61, 204.23, 106.51, all P <0.01). Statistical significance was observed in the distribution of depressive and anxious symptoms among middle school students across different gender, academic stage, school district, family type, physical activity levels, parental discipline, smoking, alcohol consumption, sleep deprivation, excessive screen time, Internet addiction, and bullying ( χ 2=14.49-991.46, all P <0.01). Multivariate Logistic regression analysis showed that compared with junior high school students, ordinary high school students had a higher risk of comorbidity ( OR=2.71, 95% CI = 2.41-3.05); girls ( OR=2.17, 95%CI =1.95-2.40), non-core family ( OR=1.20, 95%CI =1.08-1.32), and good neighborhood ( OR=1.16, 95%CI =1.02-1.30), campus bullying ( OR=4.88, 95%CI =4.32-5.50), Internet addiction ( OR=4.77, 95%CI = 3.41 -6.68), parental beating and scolding ( OR=3.18, 95%CI =2.72-3.71), alcohol consumption ( OR=2.10, 95%CI =1.86- 2.37 ), and insufficient sleep ( OR=1.73, 95%CI =1.54-1.95) had higher risks with comorbidity of depression and anxiety symptoms (all P <0.05). A nomogram prediction model was constructed based on significant variables shows that C-index=0.75 (AUC= 0.75 , 95% CI=0.74-0.76, P <0.05), and the model had good predictive performance. Conclusions The current situation of comorbidity of depressive and anxiety symptoms among middle school students in Chongqing is not optimistic. The nomograms can be used to effectively predict the risk of comorbidity of depressive and anxiety symptoms in middle school students.

Objective To establish radioresistant human non-small cell lung cancer NCI-H460R model cells and evaluate the sensitivity of these radioresistant cells to a ferroptosis inducer. Methods Radioresistant cell lines, designated as NCI-H460 R20Gy and NCI-H460 R116Gy, were generated by subjecting parental NCI-H460 cells to fractionated irradiation with varying cumulative doses. Both parental cells and the established radioresistant cell lines were each randomly divided into four groups and exposed to irradiation at 0, 2, 4, and 6 Gy, respectively. Successful establishment of the radioresistant cell lines was confirmed by colony formation assay. Subsequently, cells were treated with increasing concentrations of the ferroptosis inducer RSL-3 to assess differential sensitivity between parental and radioresistant cells to ferroptosis. Results In comparison to the parental NCI-H460 cells (D_0WT=1.2), both NCI-H460 R116Gy and NCI-H460 R20Gy cells exhibited radioresistance, with NCI-H460 R116Gy demonstrating a stronger radioresistance (D_0R116Gy=1.5) than NCI-H460 R20Gy (D_0R20Gy=1.4). Furthermore, NCI-H460 R116Gy cells exhibited increased sensitivity to RSL-3 relative to the parental cells (P < 0.001), while NCI-H460 R20Gy cells did not display a significant difference in sensitivity to RSL-3. Conclusion Human non-small cell lung cancer cells with radioresistance induced by a high cumulative irradiation dose exhibit increased sensitivity to the glutathione peroxidase 4-specific ferroptosis inducer RSL-3. This finding provides an experimental basis for optimizing combined treatment regimens involving radiotherapy and RSL-3 for non-small cell lung cancer patients with radiotherapy resistance.

Aim To evaluate the effectiveness and safety of remimazolam tosylate for administering general anesthesia in morbidly obese patients.Methods This clinical trial was conducted at a single center from De-cember 2021 to October 2023.It assessed 108 morbid-ly obese patients(body mass index,BMI≥40)who underwent laparoscopic sleeve gastrectomy.Patients were randomly assigned to either the remimazaolam group(Group R)or the propofol group(Group P)for general anesthesia induction and maintenance.The primary outcome was to compare the incidence of ad-verse events and postoperative recovery characteristics between the two groups.Results During induction pe-riod,the incidence of adverse events was higher in group P,including hypotension(P＜0.01),hypox-emia(P＜0.05),bradycardia(P＜0.01),and in-creased vasopressor requirement(P＜0.05).The time to loss of consciousness and BIS falling to 60 was shor-ter in group P than in group R(P＜0.01).There were no statistically significant differences between the two groups in terms of postoperative quality of recovery(QoR-40 score),24-hour postoperative pain visual an-alogue scale(VAS)scores and morphine consump-tion.In conclusion,remimazolam tosylate,utilized for anesthesia induction in morbidly obese patients,signif-icantly reduced hypotension and hypoxemia compared to propofol,while it could also maintain similar postop-erative recovery quality.Conclusions Remimazolam is effective in reducing the incidence of hypotension and hypoxaemia during the induction period of general anaesthesia in morbidly obese patients and it is compa-rable to propofol in terms of quality of postoperative re-covery.

To evaluate the effectiveness and safety of implantable D-shant atrial shunt device in patients with severe pulmonary arterial hypertension(PAH)and right heart failure.A 53-year-old female patient diagnosed with severe idiopathic PAH and right heart failure,her WHO FC grade was Ⅳ.The right heart catheter and implantation of D-shant atrial shunt device were performed under local anesthesia on November 30,2021.A 6 mm×4 cm peripheral artery balloon was selected to dilate the atrial septum and a D-shant atrial shunt device with a fixed 4 mm diameter orifice was implanted into the heart.The clinical symptoms and hemodynamics of the patient was improved after the intervention.Implantation of atrial shunt device as a palliative therapy to established a right to left shunt is another strategy for treating patients with severe PAH in late period,which has good effectiveness and safety.It could be the last replacement therapy to improve symptoms and prolonged lives to drug resistant and severe PAH patients.

This study was aimed at investigating the pathogenic and molecular characteristics of Klebsiella pneumoniae(KP)in fecal samples of diarrhea cases in a district of Beijing.Fecal samples from diarrhea cases in an outpatient department in a district of Beijing from 2018 to 2021 were collected,and used for isolation and culture of KP.The KP strains isolated strains were subjected to drug resistance phenotype testing and whole-genome sequencing.Multilocus sequence typing and whole-genome phyletic evolution analysis were performed on the sequencing results.The cases'epidemiological and clinical characteristics were analyzed.From 2018 to 2021,1 103 fecal samples were collected and detected.The total detection rate of KP was 10.43％(115/1 103),and the infection rate of KP mixed with other diarrhea-causing pathogens was 42.61％(49/115).The positivity rate was slightly high(12.47％,61/489)a-mong females and was highest in young adults 16-45 years of age.Small peaks were observed in January,April to May,and August to September.The gastrointestinal symptoms in cases were mainly nausea and watery stool,and the suspicious food was unknown.Ampicillin,tetracycline,and sulfafurazole were the top three antibiotics to which these 115 KP strains showed resistance,and 29 strains were resistant to multiple antibiotics.The strains were divided into 72 sequence types,among which ST23 was dominant.According to the phylogenetic tree,the strains were divided into four main branches,among which 14 ST23 strains had a very close genetic relationship with the highly virulent NTUH-K2044 reference strain.KP infection persisted in fecal samples from diarrhea cases in the district of Beijing.Women and young adults were particularly susceptible.The drug resistance of KP strains in this region was very serious,and the ST types were diverse.Moreover,the ST23 pathogenic strains were closely related to high virulence strains.

This study investigated the epidemiological and genotypic characteristics of group A rotavirus(RVA)in children under 5 years of age with diarrhea at a viral diarrhea surveillance sentinel hospital in Guangdong Province from 2021 to 2022,to provide a basis for RVA prevention and control.A total of 1 858 fecal samples from children under 5 years of age with diarrhea in 2021-2022 were collected.Rotavirus antigen was detected with ELISA,and positive samples were further sequenced and categorized.Among the 1 858 samples,156 were RVA positive.The positivity rates in boys and girls were 8.76％and 7.87％,respectively.Significant differences were observed in the detection rates of RVA infection among age groups.The rate of RVA infection increased gradually from December to April of the following year.In 2021,the main endemic strains of RVA in the Guangdong region were of the G9P[8]subtype,and the rare G8P[8]subtype increased in China.In 2022,the G8P[8]subtype surpassed the G9P[8]subtype for the first time.In cases of diarrhea in infants younger than 5 years in Guangdong Province from 2021 to 2022,the RVA genotypes were diverse,the G9P[8]genotype significantly decreased,and the G8P[8]subtype became a dominant genotype.Continuous RVA genotype monitoring remains necessary to assess the risk of RVA-related disea-ses.

Objective To explore the mechanism of Gualou Xiebai Baijiu Decoction(GXB)in improving atherosclerosis(AS)in mice by regulating the gut microbiota(GM)and its metabolites.Methods Thirty-two male ApoE-/-mice were divided randomly into a Blank group,Model group,atorvastatin(Ato)group,and GXB group(n=8 mice per group).AS was established in all mice,except the Blank group,and the respective treatments were administered by gavage.Aortic plaques were detected by Oil red O staining and pathological changes in aortic tissue were detected by hematoxylin and eosin staining.The GM was analyzed using 16S rRNA gene sequencing technology,and mouse GM metabolites,including trimethylamine oxide(TMAO),short-chain fatty acids(SCFA),and serum levels of triglycerides(TG),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),and nitric oxide(NO)were determined.Results Compared with the Blank group,mice in the Model and Ato groups showed an increase in AS plaque area(P＜0.05).Serum levels of TG,TC,and LDL-C were increased(P＜0.001)while levels of HDL-C and NO were decreased(P＜0.01,P＜0.001)in the Model group compared with the Blank group.The plaque area was decreased(P＜0.05),serum levels of TG,TC,and LDL-C were decreased(P＜0.001),and NO levels were increased(P＜0.01)in the Ato and GXB groups,while HDL-C levels were increased in the GXB group(P＜0.05)compared with the Model group.Plaque area was decreased(P＜0.05)and the NO level was increased(P＜0.01)in the GXB group compared with the Ato group.A total of 6345 characteristic sequences were obtained from 16S rRNA analysis.α-Diversity analysis indicated that GXB reduced the richness of the GM in AS mice(P＜0.001)and improved its uniformity(P＜0.05).β-Diversity analysis suggested that the microbial community structure in the GXB group was similar to that in the Blank group.The abundance of microbial communities differed among the groups at the phylum and genus levels.At the phylum level,the abundance of Proteobacteria was increased(P＜0.01)in AS mice,while GXB intervention reduced the abundance of Proteobacteria(P＜0.01)and increased the abundance of Verrucomimicrobiota(P＜0.05).At the genus level,GXB effectively increased the abundance of Akkermansia(P＜0.05).SCFAs were significantly increased(P＜0.01)and TMAO levels were significantly decreased(P＜0.01)in the GXB group compared with the Model group.Conclusions GXB can regulate the intestinal flora and intestinal flora metabolites SCFA and TMAO to improve AS.Akkermansia may be a key bacterial genus of the gut microbiota through which GXB may improve AS.

Objective:To investigate the role of matrix metalloproteinase-13 (MMP-13) in the development,diagnosis and prognosis of multiple myeloma (MM). Methods:Blood samples of 57 MM patients and 45 normal controls were collected,and real-time PCR was performed to detect the MMP-13 mRNA expression level in the study subjects,and the difference of MMP-13 mRNA level between MM patients and normal controls was compared. The correlations of MMP-13 with MM bone disease and its severity,ISS stage,DS stage,and treatment efficacy were analyzed. Results:The MMP-13 mRNA in patients with MM was significantly higher than that in normal controls (P<0.05). The MMP-13 mRNA in MM patients with bone disease was significantly higher than that in patients without bone disease,and the more severe the bone disease,the more obvious the increase in MMP-13 mRNA (P<0.05). The MMP-13 gene expression level was also significantly different between ISS and DS stage Ⅰ and stage Ⅲ patients (P<0.05),and the MMP-13 mRNA level was significantly decreased after treatment (P<0.05). Conclusion:The MMP-13 mRNA expression level is related to the occurrence and development of MM,and it has certain guiding significance in disease diagnosis and prognosis evaluation.