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 investigate the distribution of IgM anti-A/B titers among group O whole blood donors in Jiangsu, establish a low-titer threshold, and analyze the demographic characteristics of low-titer donors, so as to provide data for recruiting low-titer group O whole blood (LTOWB) donors. Methods: Plasma samples from 1 009 group O whole blood donors were tested for IgM anti-A and anti-B titers using the microplate technique. The distribution of antibody titers was analyzed to establish a low-titer threshold. The distribution trends of titers across different demographic groups were also analyzed. Results: The peak titer for anti-A, anti-B were 64 (31.5%), 4 (23.8%), respectively, The proportion of donors with both anti-A and anti-B titers below 64 was 97.3% (982/1 009). The mean anti-A titer was higher than anti-B titer. Anti-A titers were higher in female donors than in male donors (P<0.05). The anti-A titers differed significantly among different age groups (P<0.05). However, no significant difference in titers was observed based on the number of donations (P>0.05). Conclusion: A titer of 64 can be used as the reference threshold of LTOWB in Jiangsu. Male donors of appropriate age are more suitable than female donors for establishing an emergency panel of LTOWB mobile donors.

italic>Salmonella has emerged as a promising tumor-targeting strategy in recent years due to its good tumor targeting ability and certain safety. In order to further optimize its therapeutic effect, scientists have tried to modify Salmonella, including its attenuation and drug loading. This paper summarizes the mechanism and research progress of Salmonella-mediated targeted tumor therapy, and introduces the strategies and related progress of its modification and optimization. At the same time, the advantages, current challenges and future development directions of Salmonella-mediated tumor therapy are summarized.

Tumor necrosis factor-α(TNF-α)is involved in the regulation of multiple biological processes such as the proliferation,invasion,migration,and chemotherapy resistance of hepatocellular carcinoma(HCC)cells through TNF receptor-mediated signaling pathways.At the same time,TNF-α also plays a role in inducing the apoptosis of HCC cells.Some TNF-α inhibitors have been shown to inhibit the progression of HCC and prolong survival time.At present,the potential mechanism of action of TNF-α in HCC remains unclear,and exploration of the interaction between TNF-α and HCC can help to determine the potential therapeutic targets for HCC.This article summarizes the latest research advances in the mechanism of action of TNF-α in HCC and introduces the possibility of targeting TNF-α as a treatment method for HCC,in order to provide a theoretical basis for the prevention and treatment of liver cancer and drug research and development.

Objective To explore the independent risk factors that affect the overall survival(OS)of elderly patients with hepatocellular carcinoma(HCC,≥60 years old)and build a nomogram prediction model.Methods Clinical data of all elderly patients with HCC from the SEER database from 2005 to 2020 were downloaded from SEER database.In accordance with the inclusion and exclusion criteria,the screened patients were randomly assigned to a training group(70%)and a validation group(30%).The independent risk factors of elderly patients with HCC were determined by univariate and multivariate Cox regression analyses and further validated by Kaplan-Meier survival analysis.On the basis of the determined variables,nomograms were developed and verified to predict the OS of elderly patients with HCC at 6,12,and 24 months.The consistency index(C index),calibration curve,receiver's operating characteristic(ROC)curve,and area under curve(AUC)were used to evaluate the prediction efficiency and discrimination ability of the prediction model,and decision curve analysis(DCA)was used to evaluate the potential clinical application value of the nomogram.Results A total of 1134 elderly patients with HCC were included,with 793 in the training group and 341 in the validation group.Seven variables,including age,clinical grade,clinical stage,M stage,tumor size classification,and radiotherapy,were identified as independent prognostic factors of this population.The constructed nomogram shows excellent prediction performance,with C indices of 0.745 in the training group and 0.704 in the validation group.The AUC values of the training group at 6,12,and 24 months were 0.785,0.788,and 0.798,respectively,and those of the validation group were 0.780,0.725,and 0.607,respectively.The calibration curve shows good consistency from the predicted survival probability to the actual probability.The ROC curve and DCA show that the nomogram proposed in this study has good prediction ability.Conclusion Age,clinical grade,clinical stage,M stage,tumor size classification,and radiotherapy are important influencing factors for the survival of elderly patients with HCC.The prediction model of prognosis nomogram constructed in this study has good predictive value,and it can be used to predict the OS of elderly patients with HCC,which could be helpful for individualized survival assessment and clinical management of these patients.

Objective:To explore the construction and application of an evidence-based practice plan for early postoperative activity in postoperative patients with large area cerebral infarction.Methods:Ninety-six postoperative patients with large area cerebral infarction admitted to Wenzhou Central Hospital from July 2021 to April 2023 were selected as the study subjects for a Clinical trial. They were divided into the control group (48 cases) and the observation group (48 cases) by random number table method. The control group received routine postoperative care for neurosurgery, while the observation group received evidence-based systematic early activity training. Both groups were followed up until 1 month after the patient was discharged from the hospital. The time of postoperative hospitalization, hospitalization expenses, vital signs and pain investigation 48 h after surgery, daily living ability before intervention and 7 d, 1 month after discharge, neurological function before intervention and 7 d and 1 month after surgery, and complications during follow-up between the two groups were compared.Results:In the control group, there were 29 males and 19 females, with an average age of 43-67(56.87 ± 1.76) years. In the observation group, there were 31 males and 17 females, with an average age of 43-68 (57.02 ± 1.82) years. The postoperative hospital stay in the observation group was (6.87 ± 0.65) d, in the control group was (9.06 ± 0.72) d, the difference between them was significant ( t=15.64, P<0.05). 48 hours after surgery, the heart rate, breathing rate and mean arterial pressure in the observation group were (71.65 ± 0, 45) times/min, (14.76 ± 0.36) times/min and (76.98 ± 5.65) mmHg(1 mmHg=0.133 kPa), which were different with those in the control group, (82.76 ± 2.65) times/min, (18.76 ± 2.87) times/min and (93.76 ± 5.93) mmHg ( t=28.64, 9.58 and 14.19, all P<0.05). Seven days after discharge, the score of Activities of Daily Living and the National Institutes of Health Neurological Impairment Scale in the observation group were (84.65 ± 2.45) and (23.65 ± 2.65), which were different than the (79.76 ± 1.97) and (28.54 ± 2.73) in the control group ( t=10.26, 8.91, both P<0.05). A month after discharge, the score of Activities of Daily Living and the National Institutes of Health Neurological Impairment Scale in the observation group were (95.45 ± 1.43) and (18.65 ± 1.98), while in the control group were (87.87 ± 1.39) and (21.54 ± 2.76), the difference between them were significant ( t=26.33, 5.90, both P<0.05). The total incidence of complications such as postoperative bleeding, postoperative infection and hypoxemia in the observation group was 20.83% (10/48), which was significant lower than the 68.75% (33/48) in the control group ( χ2=22.28, P<0.05). Conclusions:Evidence-based systematic early activity training could significantly alleviate postoperative pain in patients with large area cerebral infarction after surgery, improve their daily living ability and neurological function, further effectively shorten their hospitalization time, and reduce the occurrence of complications.

Objective To study the clinical characteristics and bacterial antimicrobial susceptibility testing results of patients with clinically isolated Ralstonia pickettii(R.pickettii),and provide basis for the rational use of antimi-crobial agents.Methods Inpatients with R.pickettii infection who were treated at the Tianjin First Central Hospi-tal from January 2014 to December 2023 were analyzed retrospectively.Clinical characteristics and antimicrobial sus-ceptibility testing results were analyzed.Results A total of 80 strains of Ralstonia spp.were isolated over 10-year period,including 42(52.5％)non-repetitive strains of R.pickettii.Among 42 R.pickettii strains,64.3％were isolated from male patients.The strains isolated from sputum,catheter,blood,throat swabs,and drainage fluid specimens accounted for 38.1％,28.6％,19.0％,4.8％,and 2.4％,respectively.The clinical distribution of R.pickettii was highest in the intensive care unit(ICU),with a proportion of 52.4％.The number of infected patients first increased and then decreased with the years,followed by a slight fluctuation.There was no statistically signifi-cant difference in the number of infected patients in each department over the years(P＞0.05).R.pickettii had higher susceptibility rates to doxycycline,levofloxacin,ciprofloxacin,and minocycline,susceptibility rates were 78.3％-90.9％,but was completely resistant to compound sulfamethoxazole and cefazolin(100％),it also had higher resistance rates to aztreonam,colistin,cefotetan,tobramycin,amikacin,ceftazidime,and gentamicin(80.0％-97.4％).There was no statistically significant difference in the resistance rates to 21 antimicrobial agents among different years(all P＞0.05).Conclusion R.pickettii is mainly from ICU,and the majority of the infected population are adult males.Most strains are isolated from sputum and catheter.R.pickettii presents multidrug re-sistance.Attention should be paid to the changes in the resistance rates of antimicrobial agents,strengthen the dy-namic monitoring of bacterial resistance and guide the rational selection of antimicrobial agents in clinic,implement early and effective treatment to improve the prognosis of the patients.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To assess the effectiveness and safety of prone positioning in the treatment of neonatal respiratory distress syndrome(NRDS)using invasive respiratory support.Methods A prospective study was conducted from June 2020 to September 2023 at Suining County People's Hospital,involving 77 preterm infants with gestational ages less than 35 weeks requiring invasive respiratory support for NRDS.The infants were randomly divided into a supine group(37 infants)and a prone group(40 infants).Infants in the prone group were ventilated in the prone position for 6 hours followed by 2 hours in the supine position,continuing in this cycle until weaning from the ventilator.The effectiveness and safety of the two approaches were compared.Results At 6 hours after enrollment,the prone group showed lower arterial blood carbon dioxide levels,inspired oxygen concentration,oxygenation index,rates of tracheal intubation bacterial colonization,and Neonatal Pain,Agitation and Sedation Scale scores compared to the supine group(P<0.05).There were no significant differences between the groups in terms of pH,arterial oxygen pressure,positive end-expiratory pressure,duration of mechanical ventilation,accidental extubation,ventilator-associated pneumonia,air leak syndrome,skin pressure sores,feeding intolerance,and grades II-IV intraventricular hemorrhage(P>0.05).Conclusions Compared to supine positioning,prone ventilation effectively improves oxygenation,increases comfort,and reduces tracheal intubation bacterial colonization in neonates requiring mechanical ventilation for NRDS,without significantly increasing adverse reactions.

Objective To explore the difference in the effectiveness between proximal femoral nail anti-rotation(PFNA)and proximal femoral locking compression plate(PFLCP)of intertrochanteric fracture in the elderly patients combined with knee osteoarthritis.Methods The clinical data of 65 intertrochanteric femoral fractures combined with knee osteoarthritis be-tween June 2015 and February 2021 were retrospectively analyze.They were divided into two groups according to the different surgical methods.PFNA group was composed of 36 patients,12 males and 24 females,aged from 61to 88 years old with an av-erage of(77.0±6.4)years old.There were 17 cases of left injury and 19 cases of right injury.According to modified Evans clas-sification,there were 3 cases of type Ⅱ,19 cases of type Ⅲ,10 cases of type Ⅳ,and 4 cases of type Ⅴ.PFLCP group was com-posed of 29 patients,11 males and 18 females,aged from 60 to 92 years old with an average of(78.8±6.5)years old.There were 14 cases of left injury and 15 cases of right injury.According to modified Evans classification,there were 2 cases of typeⅡ,18 cases of type Ⅲ,7 cases of type Ⅳ,and 2 cases of type Ⅴ.Comparison of operation time,intraoperation blood loss,postoperative bed time,incidence of postoperative complications,Harris score at 6 months and 1 year postoperation.Results All 65 patients were followed up ranging from 12 to 24 months with an average of(16.9±3.6)months.In the PFNA and PFLCP groups,the operation time was respectively(57.6±6.8)min and(77.4±6.5)min,the intraoperative blood loss was(128.3±50.3)ml and(156.3±23.9)ml,postoperative bed time was(4.0±2.5)days and(8.1±2.0)days,Harris score at 6 months post-operative was(45.3±8.6)points and(36.3±7.0)points.There were significant differences between two groups(P＜0.05).Inci-dence of postoperative complications was 19.4％(7/36)and 34.5％(10/29),Harris score at 1 year postoperative was(60.8±6.7)points and(59.0±8.1)points.There was no significant difference between the two groups(P＞0.05).Conclusion Compared with PFLCP,PFNA treatment of elderly patients with knee osteoarthritis between the femoral intertrochanteric fractures shorter surgical time,less intraoperative blood loss,bed rest after surgery,short-term hip function recovery better,when the affected knee joint can tolerate traction,can be used as a priority.