BACKGROUND:Bone tissue loss caused by tumors and trauma can have an adverse effect on postoperative rehabilitation.Therefore,scaffold materials are usually implanted during treatment.However,the existing implant materials are relatively simple and lack antibacterial properties.Early implantation may lead to iatrogenic autoinfection and have an adverse effect on osteogenesis.OBJECTIVE:To construct a KR-12-a5 polypeptide-nanohydroxyapatite-small intestinal submucosa composite scaffold and evaluate its feasibility as a material for promoting bone defect repair.METHODS:The small intestinal submucosa scaffold and the small intestinal submucosa scaffold containing 25,50,and 100 mg/mL nanohydroxyapatite(referred to as nHA-SIS scaffold)were prepared by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-hydroxysuccinimide cross-linking method.The appropriate scaffold was screened for subsequent experiments by mechanical property testing.The antibacterial properties of KR-12-a5 polypeptide solution against Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum were detected.The nHA-SIS scaffolds were immersed in 250,500,and 1 000 μg/mL KR-12-a5 peptide solutions for 24 hours,and then freeze-dried to obtain peptide-loaded nanohydroxyapatite-porcine small intestinal submucosa composite scaffolds(denoted as P-nHA-SIS scaffolds).The sustained-release properties of the three groups of scaffolds were characterized.The nHA-SIS scaffolds and the three groups of P-nHA-SIS scaffolds were co-cultured with Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum for 24 hours or 48 hours.The scaffolds with strong antibacterial ability were screened by live and dead bacteria staining and scanning electron microscopy for subsequent experiments.The degradation properties and water absorption rates of the uncross-linked small intestinal submucosa scaffolds,cross-linked small intestinal submucosa scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were characterized.The extracts of cross-linked small intestinal submucosal scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were co-cultured with MC3T3-E1 cells.CCK-8 assay and live-dead cell staining were performed.The effects of the extracts of the three scaffolds on the migration of MC3T3-E1 cells were detected by Transwell chamber assay.RESULTS AND CONCLUSION:(1)The elastic modulus and compressive strength of 25,50,and 100 mg/mL nHA-SIS scaffolds were higher than those of small intestinal submucosal scaffolds(P＜0.05),among which the elastic modulus and compressive strength of 25 mg/mL nHA-SIS scaffolds were the highest,and this group of scaffolds were selected for subsequent experiments to load peptides.(2)KR-12-a5 peptide had strong antibacterial activity against common bacteria in bone defects(Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum).The three groups of P-nHA-SIS scaffolds all had sustained release properties.With the increase of peptide mass concentration,the antibacterial property of P-nHA-SIS scaffold was enhanced.Among them,the P-nHA-SIS scaffold loaded with 500 μg/mL peptide had achieved a satisfactory antibacterial effect,and this group of scaffolds would be selected in the future.(3)The degradation rate of the three groups of cross-linked scaffolds was lower than that of the uncross-linked scaffolds,and the water absorption rate was greater than that of the uncross-linked scaffolds.P-nHA-SIS scaffolds could promote the proliferation and migration of MC3T3-E1 cells without affecting the activity of MC3T3-E1 cells.(4)The results show that P-nHA-SIS scaffolds have strong antibacterial properties and the ability to promote the proliferation and migration of MC3T3-E1 cells,and are expected to be used in bone defect repair.

BACKGROUND:Bone tissue loss caused by tumors and trauma can have an adverse effect on postoperative rehabilitation.Therefore,scaffold materials are usually implanted during treatment.However,the existing implant materials are relatively simple and lack antibacterial properties.Early implantation may lead to iatrogenic autoinfection and have an adverse effect on osteogenesis.OBJECTIVE:To construct a KR-12-a5 polypeptide-nanohydroxyapatite-small intestinal submucosa composite scaffold and evaluate its feasibility as a material for promoting bone defect repair.METHODS:The small intestinal submucosa scaffold and the small intestinal submucosa scaffold containing 25,50,and 100 mg/mL nanohydroxyapatite(referred to as nHA-SIS scaffold)were prepared by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride/N-hydroxysuccinimide cross-linking method.The appropriate scaffold was screened for subsequent experiments by mechanical property testing.The antibacterial properties of KR-12-a5 polypeptide solution against Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum were detected.The nHA-SIS scaffolds were immersed in 250,500,and 1 000 μg/mL KR-12-a5 peptide solutions for 24 hours,and then freeze-dried to obtain peptide-loaded nanohydroxyapatite-porcine small intestinal submucosa composite scaffolds(denoted as P-nHA-SIS scaffolds).The sustained-release properties of the three groups of scaffolds were characterized.The nHA-SIS scaffolds and the three groups of P-nHA-SIS scaffolds were co-cultured with Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum for 24 hours or 48 hours.The scaffolds with strong antibacterial ability were screened by live and dead bacteria staining and scanning electron microscopy for subsequent experiments.The degradation properties and water absorption rates of the uncross-linked small intestinal submucosa scaffolds,cross-linked small intestinal submucosa scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were characterized.The extracts of cross-linked small intestinal submucosal scaffolds,nHA-SIS scaffolds,and P-nHA-SIS scaffolds were co-cultured with MC3T3-E1 cells.CCK-8 assay and live-dead cell staining were performed.The effects of the extracts of the three scaffolds on the migration of MC3T3-E1 cells were detected by Transwell chamber assay.RESULTS AND CONCLUSION:(1)The elastic modulus and compressive strength of 25,50,and 100 mg/mL nHA-SIS scaffolds were higher than those of small intestinal submucosal scaffolds(P＜0.05),among which the elastic modulus and compressive strength of 25 mg/mL nHA-SIS scaffolds were the highest,and this group of scaffolds were selected for subsequent experiments to load peptides.(2)KR-12-a5 peptide had strong antibacterial activity against common bacteria in bone defects(Staphylococcus aureus,Streptococcus gordonii,and Fusobacterium nucleatum).The three groups of P-nHA-SIS scaffolds all had sustained release properties.With the increase of peptide mass concentration,the antibacterial property of P-nHA-SIS scaffold was enhanced.Among them,the P-nHA-SIS scaffold loaded with 500 μg/mL peptide had achieved a satisfactory antibacterial effect,and this group of scaffolds would be selected in the future.(3)The degradation rate of the three groups of cross-linked scaffolds was lower than that of the uncross-linked scaffolds,and the water absorption rate was greater than that of the uncross-linked scaffolds.P-nHA-SIS scaffolds could promote the proliferation and migration of MC3T3-E1 cells without affecting the activity of MC3T3-E1 cells.(4)The results show that P-nHA-SIS scaffolds have strong antibacterial properties and the ability to promote the proliferation and migration of MC3T3-E1 cells,and are expected to be used in bone defect repair.

Objective:To explore the mechanism of Danxing Zhishuang Prescription in the treatment of Parkinson's disease (PD) by combining network pharmacology with animal models.Methods:TCMSP, BATMAN database, Genecards, and OMIM databases were retrieved to obtain the active components and action targets of Danxing Zhishuang Prescription. Venny 2.1.0 was used to intersect drug targets and PD related genes, and a protein interaction network of the intersection targets was constructed using the STRING 12.0 platform. Topology analysis was performed using Cytoscape 3.10.0 software to identify the key targets of Danxing Zhishuang Prescription on PD; GO functional and KEGG pathway enrichment analysis was performed on key targets using the WeChat platform, and molecular docking was validated through AutoDockTools 1.5.7. Using a random number table method, mice were divided into a blank control group, a model group, and a Danxing Zhishuang Prescription group, with 20 mice in each group; except for the blank group, all other groups of mice were orally administered fisetin to prepare PD models; Danxing Zhishuang Prescription group was orally administered with concentrated Danxing Zhishuang Prescription at a dosage of 10.5 g/kg, while the blank group and model group were orally administered with 0.2 ml of physiological saline for 21 days; Western blot was used to detect the expressions of Akt1, Bcl-2, Bax, and α-Syn proteins.Results:359 intersection targets, 69 core targets, and 185 active components were obtained the treatment of PD with Danxing Zhishuang Prescription. The main active components included quercetin, kaempferol, phenylalanine, etc., and the key targets were AKT1, TP53, TNF, ESR1, etc. KEGG analysis revealed several key signaling pathways, such as AGE-RAGE, PI3K-Akt, fluid shear stress and atherosclerosis signaling pathways. The validation experiment results showed that compared with the model group, the expression of Bcl-2 protein was up-regulated ( P<0.01), and the expressions of Bax, Akt1, and α-Syn proteins were down-regulated in the Danxing Zhishuang Prescription group ( P<0.01). Conclusions:Danxing Zhishuang Prescription has the advantages of multi target and multi pathway treatment for PD. Its mechanism may be related to down-regulating the expressions of Bax, Akt1, and α-Syn proteins, improving brain blood supply, regulating neurotransmitter balance, inhibiting oxidative stress response, and promoting nerve regeneration.

Objective:To explore the genetic basis for a woman with oocyte maturation disorder during assisted reproductive treatment (ART), and to verify the source of the variant and its impact on oocyte maturation through family verification.Methods:A 35-year-old infertile woman presented at the Reproductive Medicine Center of Gansu Provincial Maternal and Child Health Care Hospital on 20 October 2023 for a 10-year history of infertility despite unprotected intercourse was selected as study subject. Peripheral venous blood sample was collected from the proband. Next-generation sequencing (NGS) was used to detect the potential variant. Candidate variants were validated within her family by Sanger sequencing, and their deleteriousness was assessed with comprehensive bioinformatic analyses to elucidate their origin and impact on oocyte maturation. According to the Standards and Guidelines for the Interpretation of Sequence Variants (hereinafter referred to as ACMG Guidelines) formulated by the American College of Medical Genetics and Genomics (ACMG), the pathogenicity of the candidate variant was rated. This study was approved by the Medical Ethics Committee of Gansu Provincial Maternal and Child Health Care Hospital (Ethics No.: 2023GSFYLS78).Results:The proband underwent three controlled ovarian-stimulation cycles as part of assisted reproductive technology, yielding a total of 29 oocytes, among which only three were mature, whilst the remainders exhibited maturation arrest. Targeted sequencing of peripheral-blood DNA revealed a heterozygous c. 728C>T (p.P243L) missense variant of the TUBB8 gene. While the same variant was detected in the proband′s father. Based on the ACMG guidelines, the variant was classified to be likely pathogenic (PS4_Supporting+ PM2_Supporting+ PP2+ PP3+ PP4). Conclusion:The heterozygous c. 728C>T (p.P243L) missense variant of the TUBB8 gene probably underlay the oocyte maturation disorder in the proband, which may be either autosomal dominant or autosomal recessive. For probands with oocyte maturation disorders caused by the heterozygous c. 728C>T variant of the TUBB8 gene, oocyte donation may be considered.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective:To establish and assess the quality control and improvement system for metabolic and bariatric surgery in Beijing.Methods:Based on relevant documents from the National Health Commission and the Beijing Municipal Health Commission,and referencing the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) by the American Society for Metabolic and Bariatric Surgery,a quality control system was developed under the Beijing Quality Control and Improvement Center of Metabolic and Bariatric Surgery. The system incorporated on-site evaluations,data registration,and specialized training. From May to December 2023,on-site assessments were conducted at 21 hospitals in Beijing performing bariatric surgery,evaluating personnel qualifications,infrastructure,clinical workflows,and postoperative follow-up. A quality control database was created to collect real-time surgical data,and training was provided for data entry and professional skills. Assessment results were classified as excellent,qualified,or needing improvement,with rectification suggestions offered and follow-up visits conducted to track progress.Results:All 21 hospitals achieved a 100% compliance rate for surgical indications, 16 (76.2%) met standardized surgical operation criteria,and 14 (66.7%) had standardized postoperative management. However,only 5 (23.8%) achieved a 12-month postoperative follow-up rate of ≥60%,and 4 (19.1%) had established specialized databases. Key challenges included insufficient specialized staffing (19.1%), lack of multidisciplinary collaboration (47.6%), inadequate equipment (57.1%), and low follow-up rates (57.1%). The database collected data from over 2 000 patients across 111 fields. After rectification, specialized database coverage rose to 61.9% (13 hospitals). Multi-level training programs developed backbone physicians and specialized nurses,significantly addressing the shortage of specialized personnel.Conclusion:The quality control system established in this study,through the integration of on-site evaluation,data registration,and specialized training,effectively enhances the standardization of surgical practices and data management capabilities.

Objective To summarize the clinical features and prognosis of children suffered from malignant solid tumors of head and neck.Methods The clinical data of children with primary malignant solid tumors located in the head and neck was retrospectively analyzed from January 2007 to December 2021 in the Department of Oncology,Beijing Children's Hospital,Capital Medical University,and the clinical features,prognostic factors were summarized.Results A total of 234 children with malignant solid tumors of head and neck were included,with a male to female ratio of 1∶0.7,aged from 3 months to 17 years and 6 months(median age 51 months).173 cases(73.9％)were treated with local painless masses.Other symptoms included snoring and facial paralysis.The proportion of rhabdomyosarcoma(RMS)was the highest(145 cases,62.0％),followed by neuroblastoma(NB)(25 cases,10.7％),Ewing sarcoma(19 cases,8.1％),etc.A total of 47 cases(20.1％)had distant metastasis.The patients received surgery,chemotherapy and radiotherapy under the mode of multidisciplinary treatment(MDT).The 3-year and 5-year overall survival(OS)were 80.8％and 75.8％,respectively,and the 3-year and 5-year progression free survival(PFS)were 64.0％and 58.9％,respectively.Tumor survivors had abnormal appearance or facial motor function(49 cases,41.2％),developmental problems or abnormal tooth loss(18 cases,15.1％),and other long-term complications that may be related to the tumor or treatment.Conclusion There are various pathologic types of pediatric head and neck malignant solid tumors,RMS and NB are the most common.Local painless mass was the most common complaint.Distant metastasis is an independent risk factor for the prognosis of head and neck malignant solid tumors.Under the MDT model,the prognosis of malignant solid tumors of the head and neck in our center was generally good.In the treatment of the tumors,the side effects and sequelae should be controlled as small as possible under the premise of long-term survival.

With the rapid development of artificial intelligence(AI),how to digitize the teaching of Medical Immunology is a new challenge posed by the times and education.This study is based on the advanced teaching model of Medical Immunology,which includes lectures-PAD class-flipped classrooms-expert lecture.By introducing knowledge mapping and AI teaching assistant into the entire learning process,the students not only deepen their understanding of the knowledge system of Medical Immunology,but also ex-ercise their ability to apply immunological knowledge to solve practical clinical problems,enhance their self-learning ability,expres-sion ability,communication ability,on-site performance ability,and cultivate a spirit of unity,cooperation,and exploration.The practice of empowering Medical Immunology teaching with digital intelligence achieves the integration of theory and application,the linkage between in class and out of class teaching,the connection between commonalities and individualities,and the union of abili-ties and qualities in Medical Immunology teaching.It also provides practical basis for exploring the implementation path of digital intel-ligence empowerment in Medical Immunology teaching.

Objective:To analyze the differences in pediatric CT radiation dose and scanning parameter Settings between children's specialized hospitals and general hospitals, and to provide reference for the optimization strategy of pediatric CT radiation dose.Methods:From July to August 2022, a stratified sampling method was used to select 7 comprehensive hospitals and 2 children's hospitals in Tianjin, and on-site survey was conducted to collect the dose data of children's head, chest, and abdomen and pelvic CT examinations in these hospitals. The Wilcoxon rank sum test was used to analyze the differences in CTDI vol and DLP of the same age group and examination site among different types of hospitals, and the stepwise regression analysis method was used to analyze the effects of age, examination site, and scanning parameters on radiation dose CTDI vol and DLP. Results:The CTDI vol and DLP of head (1-<5, 5-<10, 10-<15 years old group), chest (5-<10, 10-<15 years old group) and abdomen (1-<5, 5-<10, 10-<15 years old group) in children's specialized hospitals were lower than those in general hospitals (head, 1-<5, 5-<10, 10-<15 years old group, CTDI vol: Z=-9.32, -6.17, -9.86, P<0.001, DLP, Z=-4.41, -4.14, -5.76, P<0.001; chest, 5-<10, 10-<15 years old group, CTDI vol: Z=-3.84, -5.35, P<0.001, DLP, Z=-3.59, -4.63, P<0.001; abdomen, 1-<5、5-<10 and 10-<15 years old group, CTDI vol: Z=-7.88, -7.78, -8.53, P<0.001, DLP, Z=-7.24, -5.92, -3.44, P<0.001). The CT radiation dose in children was positively correlated with age, tube voltage, tube current time product and scan length, and negatively correlated with pitch and hospital type (general hospital and children's hospital) . Conclusion:There are some differences in the CT radiation dose and scanning parameters between children's hospitals and general hospitals. The results indicate that there is still much room for improvement in the optimization of radiation dose in pediatric CT examination.