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:Premature birth is a major global health problem associated with high mortality and morbidity.White matter injury is the most common brain injury in preterm infants.Salvia miltiorrhiza is a traditional herbal plant that is commonly used to treat cardiovascular and cerebrovascular diseases in Asian countries. OBJECTIVE:To investigate the therapeutic effect of Salvia miltiorrhiza on white matter injury in preterm infants. METHODS:Eighteen neonatal male Sprague-Dawley rats at 3-day gestational age were selected and randomized into normal group,white matter injury group,and Salvia miltiorrhiza group.Animal models of preterm white matter injury were established by permanent ligation of the right common carotid artery in the latter two groups.Rats in the Salvia miltiorrhiza group were given intraperitoneal injection of Salvia miltiorrhiza(5 mg/kg·d)for 7 consecutive days.Normal group and white matter injury group were given the same volume of PBS for intervention.On the 14th day after modeling,the rats were sacrificed.Brains were pathologically observed by hematoxylin-eosin staining under microscope,and the expression levels of myelin basic protein and CC1 in brain tissue were visualized using immunofluorescence.Furthermore,liquid chromatography-tandem mass spectrometry was used to analyze possible pathways for the action of Salvia miltiorrhiza. RESULTS AND CONCLUSION:In the white matter injury group,the structure of the corpus callosum was irregular and the cells appeared swollen and necrotic.In addition,induction of white matter injury resulted in significantly reduced myelin formation,with irregular and loosely arranged nerve fibers and significantly decreased myelin sheaths.Interestingly,white matter injury rats treated with Salvia miltiorrhiza had reduced cellular swelling,reduced lesions,and increased myelin sheaths.The expression of myelin basic protein was closely related to myelin formation,and CC1 was a marker of myelin oligodendrocytes.Salvia miltiorrhiza significantly up-regulated the expressions of myelin basic protein and CC1 in white matter injury rats(P＜0.000 1),indicating that Salvia miltiorrhiza alleviated white matter injury.Liquid chromatography-tandem mass spectrometry analysis showed that the therapeutic effect of Salvia miltiorrhiza in the rat model of white matter injury was closely related to the regulation of complement and coagulation cascades.To conclude,Salvia miltiorrhiza may be a potential therapeutic agent for treating preterm white matter injury.

Most chemical medicines have polymorphs. The difference of medicine polymorphs in physicochemical properties directly affects the stability, efficacy, and safety of solid medicine products. Polymorphs is incomparably important to pharmaceutical chemistry, manufacturing, and control. Meantime polymorphs is a key factor for the quality of high-end drug and formulations. Polymorph prediction technology can effectively guide screening of trial experiments, and reduce the risk of missing stable crystal form in the traditional experiment. Polymorph prediction technology was firstly based on theoretical calculations such as quantum mechanics and computational chemistry, and then was developed by the key technology of machine learning using the artificial intelligence. Nowadays, the popular trend is to combine the advantages of theoretical calculation and machine learning to jointly predict crystal structure. Recently, predicting medicine polymorphs has still been a challenging problem. It is expected to learn from and integrate existing technologies to predict medicine polymorphs more accurately and efficiently.

Objective:To analyze the drug-resistant gene loci of Mycoplasma pneumoniae (MP) using metagenomic next-generation sequencing (mNGS). Methods:From November 2022 to October 2023, 697 clinical samples (including sputum, alveolar lavage fluid and blood) of 686 children with Mycoplasma pneumoniae positive detected by mNGS were retrospectively analyzed. Samples were divided into intensive care unit (ICU) group and non-ICU group, Chi-square test was used to compare groups, and Mann-Kendall trend test was used to analyze the change trend of the detection rate of drug resistance gene loci over time. Results:Of the 697 samples, 164 were from the ICU group and 533 were from the non-ICU group. The detection rate of Mycoplasma pneumoniae resistance gene was 44.3% (309/697), and all detected drug-resistant gene loci of MP were A2063G. The detection rate of Mycoplasma pneumoniae in ICU group was 50.0% (82/164), and the detection rates of Mycoplasma pneumoniae resistance gene loci in sputum, alveolus lavage fluid and blood samples were 75.0% (18/24) and 48.4% (62/128), respectively. The detection rate in sputum was higher than alveolus lavage fluid samples ( χ2=5.72, P=0.017). The detection rate of Mycoplasma pneumoniae in non-ICU group was 42.6% (227/533), the detection rate of Mycoplasma pneumoniae resistance gene loci in sputum and alveolar lavage fluid was 40.0% (16/40), 44.3% (201/454), and no detection rate in blood samples (0/12). There was no significant difference in the detection rate of alveolar lavage fluid and sputum ( χ2=0.27, P=0.602). From November 2022 to October 2023, the detection rate of submitted samples showed an increasing trend month by month (overall: Z=3.99, ICU inspection group: Z=2.93, non-ICU group: Z=3.01, all P<0.01). Among the bacteria commonly detected with Mycoplasma pneumoniae, Streptococcus pneumoniae accounted for the highest proportion, the detection rate was 15.5% (108/697), and Epstein-Barr virus accounted for the highest proportion of 17.6% (123/697). Conclusions:From November 2022 to October 2023, the detection rate of Mycoplasma pneumoniae drug resistance gene loci showed an increasing trend. The detection rate of drug resistance gene loci in sputum samples of ICU group was higher than alveolus lavage fluid. No new drug resistance site were detected.

We report a case of a male patient who developed persistent fever and central nervous system symptoms after eating raw snails for 10 days. The patient was diagnosed with Angiostrongyliasis depended on the clinical presentation, epidemiological history, and etiological results. The patient recovered after receiving albendazole anthelmintic and dexamethasone anti-inflammatory therapy. This article incorporates literature review to sort out the diagnosis and treatment of this patient, in order to provide feasible reference for clinicians.

We report a case of a male patient who developed persistent fever and central nervous system symptoms after eating raw snails for 10 days. The patient was diagnosed with Angiostrongyliasis depended on the clinical presentation, epidemiological history, and etiological results. The patient recovered after receiving albendazole anthelmintic and dexamethasone anti-inflammatory therapy. This article incorporates literature review to sort out the diagnosis and treatment of this patient, in order to provide feasible reference for clinicians.

Objective:To investigate the distribution and hantavirus (HV) carrying state in host animals of hemorrhagic fever with renal syndrome (HFRS) in Henan Province from 2019 to 2022.Methods:Host animal monitoring was carried out at the monitoring sites of HFRS in Henan Province. The real-time fluorescence quantitative PCR was used to detect hantavirus in rat lungs. The types of hantavirus were analyzed. The positive samples were sequenced and then sequence homology and variation were analyzed.Results:A total of 1 308 rodents were captured from 2019 to 2022, 16 specimens of rat lungs tested positive for hantavirus nucleic acid. The positive rate of HV was 1.22% (16/1 308). According to type, the positive rate of HV in Apodius agrarius was the highest (68.75%, 11/16). According to distribution, the positive rate of HV in field samples was the highest (2.50%, 12/480), and the positive rate of HV in residential samples was 0.53% (4/759). The typing results of 16 positive samples showed that all viruses were hantavirus type Ⅰ (hantaan virus). The positive samples were sequenced and eight S gene fragments (GenBank number: OQ681444-OQ681451) and six M gene fragments (OQ681438-OQ681443) were obtained. The S and M gene fragments were similar to the Shaanxi 84FLi strain and Sichuan SN7 strain. Phylogenetic analysis of S and M gene fragments showed that they all belonged to the hantaan virus-H5 subtype. Amino acid sequence analysis revealed that, compared with the hantaan virus vaccine strain 84FLi, the 74th amino acid encoded by eight S fragments was replaced by aspartamide with serine. Tryptophan was replaced by glycine at the 14th position of Gn region in XC2022047, and isoleucine was replaced by alanine at the 359 position of XC2022022 and XC2022024.Conclusion:The hantavirus carried by host animals in Henan Province from 2019 to 2022 belongs to the type Ⅰ (hantaan virus), and Apodemus agrarius is still the dominant host animal of the hantaan virus. Compared with the vaccine strains, amino acid sites are replaced in the immune epitopes of the S and M gene fragments.

Objective To investigate the associations of reproductive health indicators with lung function and chronic obstructive pulmonary disease(COPD)among women aged 40 years and above.Methods From Jul to Sep,2021,female subjects aged 40 years and above were randomly selected from the Shanghai Suburban Adult Cohort and Biobank for COPD screening.A questionnaire was used to obtain information on demographic characteristics and reproductive health indicators.Linear regression was used to analyze the effects of reproductive health indicators on forced vital capacity(FVC)and forced expiratory volume in the first second(FEV1).Logistic regression was also used to analyze the effects of reproductive health factors on FVC as a percentage of the predicted value(FVC%Pred)and FEV1%Pred as well as on COPD.Results A total of 1876 women aged 40 years and above were enrolled with mean age of(62.1±8.2)years old,among them,78.1%were menopausal,and 40.9%had been pregnant≥3 times.Multivariate analysis showed that FVC and FEV1 decreased in postmenopausal women,but menopause was not associated with a decrease in their percentage of predicted values.Pregnancies≥3 times was a risk factor for COPD(for 3 times,OR=4.92,95%CI:1.48-19.95,P<0.05;for≥4 times,OR=9.06,95%CI:2.32-41.57,P<0.01),while pregnancies of 2 times did not increase the risk of COPD.Conclusion In women aged 40 years and above,menopause is associated with poorer FVC and FEV1,and excessive pregnancy(≥3 times)is a risk factor for COPD.

Objective To investigate the differences in clinical characteristics among children on prolonged mechanical ventilation(PMV)due to different primary diseases.Methods A retrospective analysis was performed on the clinical data of 59 pediatric patients requiring PMV from July 2017 to September 2022.According to the primary disease,they were divided into respiratory disease(RD)group,central nervous system(CNS)group,neuromuscular disease(NMD)group,and other disease group.The four groups were compared in terms of general information,treatment,and outcome.Results There were significant differences among the four groups in age,body weight,Pediatric Logistic Organ Dysfunction-2(PELOD-2)score,Pediatric Risk of Mortality Ⅲ(PRISM Ⅲ)score,analgesic and sedative treatment,nutrition supply,rehabilitation treatment,tracheotomy,successful ventilator weaning,and outcomes(P＜0.05).Compared with the RD group,the CNS group and the other disease group had a significantly higher age and a significantly higher proportion of children receiving rehabilitation treatment,and the CNS group had a significantly higher proportion of children receiving tracheotomy(P＜0.008).Compared with the other disease group,the CNS group and the NMD group had significantly lower PELOD-2 and PRISM Ⅲ scores,and the CNS group had a significantly higher proportion of children with successful ventilator weaning and a significantly higher proportion of children who were improved and discharged(P＜0.008).Conclusions There are differences in clinical characteristics among children receiving PMV due to different etiologies.Most children in the RD group have a younger age,and children in the CNS group have a relatively good prognosis.

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.