BACKGROUND:Gradient artificial bone repair scaffolds can mimic unique anatomical features in musculoskeletal tissues,showing great potential for repairing injured musculoskeletal tissues. OBJECTIVE:To review the latest research advances in gradient artificial bone repair scaffolds for tissue engineering in the musculoskeletal system and describe their advantages and fabrication strategies. METHODS:The first author of the article searched the Web of Science and PubMed databases for articles published from 2000 to 2023 with search terms"gradient,bone regeneration,scaffold".Finally,76 papers were analyzed and summarized after the screening. RESULTS AND CONCLUSION:(1)As an important means of efficient and high-quality repair of skeletal system tissues,gradient artificial bone repair scaffolds are currently designed bionically for the natural gradient characteristics of bone tissue,bone-cartilage,and tendon-bone tissue.These scaffolds can mimic the extracellular matrix of native tissues to a certain extent in terms of structure and composition,thus promoting cell adhesion,migration,proliferation,differentiation,and regenerative recovery of damaged tissues to their native state.(2)Advanced manufacturing technology provides more possibilities for gradient artificial bone repair scaffold preparation:Gradient electrospun fiber scaffolds constructed by spatially differentiated fiber arrangement and loading of biologically active substances have been developed;gradient 3D printed scaffolds fabricated by layered stacking,graded porosity,and bio-3D printing technology;gradient hydrogel scaffolds fabricated by in-situ layered injections,simple layer-by-layer stacking,and freeze-drying method;and in addition,there are also scaffolds made by other modalities or multi-method coupling.These scaffolds have demonstrated good biocompatibility in vitro experiments,were able to accelerate tissue regeneration in small animal tests,and were observed to have significantly improved histological structure.(3)The currently developed gradient artificial bone repair scaffolds have problems such as mismatch of gradient scales,unclear material-tissue interactions,and side effects caused by degradation products,which need to be further optimized by combining the strengths of related disciplines and clinical needs in the future.

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.

Diabetic nephropathy(DN)is a serious complication of diabetes mellitus and a leading cause of end-stage renal diseases.In DN patients,key pathological mechanisms include proteinuria,glomerulo-sclerosis,and fibrosis,largely driven by poor glycemic control and oxidative stress caused by prolonged hyperglycemia.This stress damages renal podocytes and triggers inflammatory mesenchymal infiltration of renal tubular cells,exacerbating the progression of proteinuria and fibrosis.Human umbilical cord-de-rived mesenchymal stem cells(hUC-MSCs)offer promising potential for treating DN due to their strong anti-oxidative properties.In this study,we developed a DN mouse model and treated the mouse via tail vein injections of hUC-MSCs(1×106 cells/mouse).The results indicated that hUC-MSCs significantly lowered fasting blood glucose levels(22.5±3.0 vs 14.7±1.1,P＜0.01)and improved glucose toler-ance,as shown by intraperitoneal glucose tolerance test(IPGTT)results(P＜0.05).Additionally,the renal function improved in hUC-MSCs-treated mice,with marked reductions in oxidative stress markers,including blood urea nitrogen(BUN),urinary creatinine(Ucr),urinary protein(PRO),superoxide dismutase(SOD),and malondialdehyde(MDA)(P＜0.05).Histological analyses through hematoxy-lin-eosin(H&E),Periodic Acid-Schiff(PAS),and Sirius red staining demonstrated alleviation of glo-merular mesangial hyperplasia,glomerular hypertrophy,and tubular inflammation.Furthermore,hUC-MSCs treatment downregulated the expression of oxidative stress-related proteins,such as NADPH oxi-dase 4(NOX4)and thioredoxin-interacting protein(TXNIP),and reduced reactive oxygen species(ROS)production(P＜0.05).Meanwhile,human renal cortical proximal tubule epithelial cells(HK-2 cells)were selected for validation in vitro experiments using high glucose treatment followed by super-natants of hUC-MSCs(MSC-CM),and Western blotting showed that the expression of both NOX4 and TXNIP was inhibited(P＜0.05)and ROS expression was reduced.In conclusion,hUC-MSC treatment effectively lowered blood glucose levels and improved renal function in DN mice,likely through the sup-pression of NOX4 expression and TXNIP-mediated oxidative stress.

Aim To investigate the effect of total gly-cosides of peony on Th17/Treg balance in autoimmune thyroiditis(AIT)by regulating miR-155 expression.Methods Sixty female SD rats were randomly divided into a blank control group,a model group,high-dose,medium,and low-dose groups of total glycosides of peony,and a Western medicine control group(seleni-um yeast group).After eight weeks of modeling,the pathological changes in thyroid tissue were observed by HE staining,the expression of miR-155 in the thyroid of rats was detected by RT-PCR,the targeting effect of miR-155 on SOCS1 was verified by dual luciferase method,and the levels of TGAb,TPOAb,IL-10,and IL-17 in peripheral serum were detected by ELISA,the expression of thyroid SOCS1 was detected by WB,and the proportion of Th17 and Treg in CD4+cells of the spleen was detected by flow cytometry.Results Com-pared with the blank group,the expression of miR-155 in the thyroid gland of the model group rats significant-ly increased,and the serum levels of TGAb,TPOAb,and IL-17 significantly increased,with an increase in the proportion of Th17;the IL-10 level significantly decreased,the proportion of Treg decreased,and the expression of SOCS1 protein decreased,with statistical significance(P＜0.01);compared with the model group,the high,medium,and low dose groups of total glycosides of peony and selenium yeast groups showed a decrease in miR-155 expression,a decrease in TGAb,TPOAb,IL-17 levels,a decrease in Th17 pro-portion,an increase in IL-10 level,an increase in Treg proportion,and an increase in SOCS1 expression,all with statistical significance(P＜0.01).Moreover,the improvement in the medium dose group of total glyco-sides of peony was more significant.Conclusion To-tal glycosides of peony downregulate miR-155 expres-sion,regulate Th17/Treg balance,alleviate inflamma-tory response,and exert immune regulatory effects.

Aim To investigate the potential role and related mechanisms of protein phosphatase 2Cm(PP2Cm)overexpression in atorvastatin-induced insu-lin resistance.Methods Male C57BL/6J mice,fibro-blast growth factor 21 knockout(FGF21-KO)mice,and wildtype(WT)mice were raised for 12 weeks to construct models.Groups included atorvastatin,con-trol,atorvastatin+PP2Cm overexpression(OE),FGF21-KO+vehicle,FGF21-KO+PP2Cm OE,WT+vehicle,WT+PP2Cm OE.Body weight,fasting blood glucose levels,fasting insulin levels,and intraperitoneal glucose tolerance tests(IPGTT)were measured in 4,8 and 12 weeks.The concentrations of branched-chain a-mino acids(BCAA)in cells,tissues and serum,as well as the mRNA and protein expression of BCAA cat-abolic enzymes,were determined by qRT-PCR,Western blot and ELISA after atorvastatin treatment.Further-more,the effects of PP2Cm overexpression on these in-dicators were explored,and the FGF21 was verified in vivo and in vitro.Results Atorvastatin induced insu-lin resistance in mice,altered insulin,glucose tolerance and increased BCAA levels.PP2Cm overexpression mitigated these changes.In the Atorvastatin+PP2Cm OE group,FGF21 mRNA,protein and concentration were all significantly upregulated.Regardless of PP2Cm overexpression,the knockout of FGF21 signifi-cantly increased BCAA expression levels,both fasting insulin and blood glucose levels were significantly high-er than those in WT group.Conclusions FGF21 may be an important regulator of PP2Cm involved in atorv-astatin-induced insulin resistance.PP2Cm overexpres-sion alleviates the effects of atorvastatin-induced insulin resistance by regulating FGF21.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective:To investigate the efficacy and toxicity of blinatumomab in the first-line and second-line treatment of pediatric B-cell acute lymphoblastic leukemia (B-ALL).Methods:A multi-center retrospective cohort study was conducted to analyze clinical data from 323 pediatric B-ALL patients treated with blinatumomab across 14 hospitals in China from May 2021 to July 2023. Patients were divided into four groups based on the treatment phase and disease status when blinatumomab was used: relapsed/refractory group, post-consolidation minimal residual disease (MRD)-positive group, early MRD-positive group, and MRD-negative group. Blinatumomab for the relapsed/refractory group was considered as second-line treatment, while the other 3 groups as first-line treatment. The MRD negativity rate after treatment, the survival rates and the incidence of severe adverse events were compared across these groups. Patients who received blinatumomab for more than 7 days were included in the efficacy analysis. Survival analysis was performed using the Kaplan-Meier method, and Log-Rank test was used to compare the survival rates among groups.Results:Among the 323 patients, 191 (59.1%) were male, with the age of 6.2 (3.9, 10.5) years. There were 117 patients in the relapsed/refractory group, 62 cases in the post-consolidation MRD-positive group, 43 cases in the early MRD-positive group, and 101 cases in the MRD negative group. In the relapsed/refractory group, the complete remission rate and MRD negativity rate after one course of blinatumomab were 71.4% (35/49) and 81.5% (75/92) for the 49 children without complete remission and the 92 children with flow cytometry-positive MRD, respectively. In the post-consolidation MRD-positive group, the MRD negativity rates after one course of blinatumomab were 100.0% (27/27), 12/16 and 9/19 for patients with MRD positivity detected by flow cytometry, polymerase chain reaction and next-generation sequencing, respectively. In the early MRD-positive group, the MRD negativity rates were 96.7% (29/30) and 9/9 for flow cytometry and next-generation sequencing, respectively. The 2-year overall survival rate and event-free survival rate for the 319 children evaluable for efficacy were (90.6±1.7)% and (87.6±1.9)%, respectively, with the relapsed/refractory group showing significantly lower overall survival rates and event-free survival rate compared to the other groups ( χ2=21.40, 26.21,both P<0.001). Grade 3 or higher adverse events occurred in 128 cases (39.6%), with hematological toxicity observed in 101 cases, while cytokine release syndrome (CRS), infection, and neurotoxicity occurred in 11, 26 and 8 cases, respectively. In addition, there were statistically significant differences in the grade 3 or higher CRS among the four groups ( χ2=8.03, P<0.05). Conclusion:Blinatumomab can clear MRD more effectively and achieve superior survival outcomes when used as first-line treatment for pediatric B-ALL, with less CRS.

Objective:To explore the feasibility and clinical outcomes of transperineal prostate multimodal image fusion-targeted biopsy under the day surgery model.Methods:Clinical data of 258 patients who underwent transperineal prostate biopsy at the Second Affiliated Hospital of Xi’an Jiaotong University between December 2022 and June 2024 were retrospectively analyzed. Patients were divided into two groups，and the experimental group（ n = 141）underwent transperineal prostate multi-modal image-fusion targeted biopsy in the day-surgery mode，with age of（70.0 ± 8.8）years，median prostate-specific antigen（PSA）level of 11.10（7.63?17.06）ng/ml，and median Prostate Imaging Reporting and Data System（PI-RADS）score of 4（3，5）. The control group（ n = 117）underwent traditional transperineal systematic biopsy，with age of（69.3 ± 7.4）years，median PSA of 25.20（16.18-54.40）ng/ml，and median PI-RADS score of 4（3，5）. The experimental group was given the day surgery mode：preoperatively，multiparametric magnetic resonance imaging（mpMRI）of the prostate was multimodally fused with ultrasound images，the location of target lesions in the prostate was manually mapped，and a targeted biopsy plan was developed. Intraoperatively，under ultrasound guidance，precise puncture was performed at the lesion sites，followed by systematic biopsy. After the operation，the patients were observed for 4-6 hours，and could be discharged if there were no obvious abnormalities，with the total hospitalization time within 24 hours. For the control group，the conventional biopsy mode was used. Intraoperatively，under ultrasound guidance，the standard 12-core transperineal systematic biopsy protocol was adopted，and sampling was conducted according to the anatomical regions of the prostate（base，midportion，apex，transition zone，and peripheral zone）to cover the entire gland. Patients in this group required routine hospitalization，with a hospital stay of 3-5 days. Operative time，intraoperative pain Numerical Rating Scale（NRS）score，complications within one week postoperatively，treatment costs，overall prostate cancer detection rate，and clinically significant prostate cancer（csPCa，defined as Gleason score ≥ 7 or pathological stage ≥ T 2b）detection rate were compared between the two groups. Results:All procedures were successfully completed without special incidents. The operative time was（13.49 ± 2.00）min in the experimental group and（13.05 ± 2.89）min in the control group，showing no significant difference（ P > 0.05）. The intraoperative pain NRS scores were（3.01 ± 1.17）and（3.10 ± 1.25）in the experimental and control groups，respectively，with no significant difference（ P > 0.05）. Pathological examination revealed that the overall prostate cancer detection rates were 46.8%（66/141）in the experimental group and 42.7%（50/117）in the control group，while the csPCa detection rates were 35.5%（50/141）and 31.6%（37/117），respectively. The differences were not statistically significant（ P > 0.05）. The complication rate was 6.4%（9/141）in the experimental group（including 2 cases of acute urinary retention，3 hematuria，3 fever，and 1 sepsis）and 6.0%（7/117）in the control group（including 3 acute urinary retention，1 hematuria，2 fever，and 1 sepsis），with no significant difference（ P > 0.05）. All complications improved after symptomatic treatment. The treatment costs were（4 063.25 ± 67.26）yuan in the experimental group and（5 185.14 ± 469.15）yuan in the control group，demonstrating a statistically significant difference（ P < 0.05）. Conclusions:Transperineal prostate multimodal image fusion-targeted biopsy can be safely performed under the day surgery model，offering advantages including a relatively high detection rate for csPCa，low complication rate，and better cost-effectiveness.