ObjectiveTo construct a multifunctional liposomal delivery system by replacing cholesterol（Chol） in conventional liposomes with saikosaponin D（SSD） and modifying with poloxamer 407（P407） for co-delivery of curcumin（Cur）. The system was evaluated for in vivo tumor targeting and inhibitory effects on mouse subcutaneous solid tumors. MethodsSingle-factor and orthogonal tests combined with information entropy weighting were used to optimize the formulation process of the liposome with encapsulation efficiency and absolute Zeta potential as indexes， and validation studies and liposomal characterization were performed. A subcutaneous solid tumor model was established by injecting H22 hepatocellular carcinoma cells subcutaneously into the dorsal surface of the right forelimb of mice. DiR-loaded traditional Chol liposomes（P407-DiR-Chol-LPs， PDCL） and novel SSD-based liposomes（P407-DiR-SSD-LPs， PDSL） were prepared by the optimized formulation process， and tail vein injection was performed to investigate the impact of SSD on liposome tumor targeting with small animal in vivo imaging. Mice were randomly divided into eight groups， including blank group， model group， free doxorubicin（DOX） group（2 mg·kg^-1）， free Cur group（8 mg·kg^-1）， free SSD group（10 mg·kg^-1）， P407-Cur-Chol-LPs（PCCL） group， P407-SSD-LPs（PSL） group， and P407-Cur-SSD-Lps（PCSL） group. Treatments were administered intraperitoneally every other day for seven doses. Antitumor efficacy and biocompatibility were evaluated by monitoring body weight change， organ indices， tumor volume and mass， relative tumor proliferation rate（T/C）， and tumor growth inhibition rate（TGI）. Histopathological analysis of liver， kidney， and tumor tissues was performed using hematoxylin-eosin（HE） staining. Serum levels of aspartate aminotransferase（AST）， alanine aminotransferase （ALT）， blood urea nitrogen（BUN）， and creatinine（Crea）in mice were quantified by fully automated biochemical analyzer. ResultsOrthogonal test yielded optimal ratios of Cur， SSD， and P407 to soybean phosphatidylcholine（SPC） as 1∶25， 1∶20， and 1∶4. The optimized PCSL exhibited spherical morphology with a particle size of 179.15 nm， a Zeta potential of -47.25 mV， and an encapsulation efficiency of 96.40%. Its in vitro release profile conformed to first-order kinetics， demonstrating excellent storage stability and hemocompatibility. In vivo imaging revealed that the fluorescence signal in tumor tissues and the fluorescence intensity ratio between tumors and organs were significantly higher in the PDSL group than in the PDCL group（P<0.05， P<0.01）. Among the treatment groups， PCSL group showed superior efficacy over free Cur group， free SSD group， PCCL group， and PSL group， with TGI>40% and T/C<60%， indicating pronounced anti-hepatocellular carcinoma effects（P<0.05， P<0.01）. Histopathology and serum biochemistry indicated minimal hepatorenal toxicity and improved hepatic and renal function in PCSL-treated mice. ConclusionReplacing Chol with SSD in preparing multifunctional drug delivery systems not only stabilizes liposomes but also yields superior anti-hepatocellular carcinoma efficacy， achieving the effect of drug-excipient integration. Co-delivery of Cur via this system can be used for treating subcutaneous solid tumors in hepatocellular carcinoma， providing new insights and technical approaches for anti-hepatocellular carcinoma research and the meridian-guiding and messenger-directing theory in traditional Chinese medicine.

Background Previous studies have found that exposure to benzo[a]pyrene (BaP) can lead to functional impairment of the human pancreas. Pancreatic and duodenal homeobox factor 1 (PDX-1) may play a role in regulating mitochondrial function. It is hypothesized that BaP exposure may interfere with PDX-1 expression in human pancreatic ductal epithelial cells (H6C7), thereby affecting mitochondrial transcription factor A (TFAM). This process could induce mitochondrial DNA (mtDNA) damage, disrupt pancreatic development and function, and elevate the risk of diabetes onset. Objective To investigate the mechanism of BaP-induced mtDNA damage through disruption of the PDX-1/TFAM pathway in a H6C7 cell model. Methods A H6C7 cell injury model was established using different concentrations of BaP. Cell viability was determined using cell counting kit-8 (CCK-8). After 24 h of BaP exposure (5,10, and 20 μmol·L⁻¹), cell morphological and mitochondrial membrane potential (MMP) changes were observed via confocalmicroscopy, and PDX-1/TFAM protein expression levels were assessed. Bioinformatics analysis combined with dual-luciferase reporter assays was used to confirm PDX-1 directly targeting the TFAM promoter. Following PDX-1 overexpression or silencing in BaP treated cells, flow cytometry was used to evaluate viability and apoptosis, while Western blot and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) measured PDX-1/TFAM expression and mitochondrial DNA copy number (mtDNA-cn). Results The cell injury model demonstrated that, compared with the control group, BaP exposure reduced cell viability, disrupted membrane integrity, induced nuclear fragmentation, and decreased MMP. Protein expression levels of PDX-1 and TFAM were significantly downregulated in the 10 and 20 μmol·L⁻¹ groups (P<0.05). Dual-luciferase reporter assays confirmed that PDX-1 overexpression upregulated TFAM levels. Flow cytometry revealed that PDX-1 overexpression significantly reduced apoptosis rate (P<0.001), whereas PDX-1 silencing increased apoptosis rate (P<0.001). Compared with the BaP-only group, BaP+PDX-1 overexpression elevated TFAM protein and mRNA expression as well as mtDNA-cn (P<0.01), while BaP+siRNA-PDX-1 suppressed these parameters (P<0.001). Conclusion BaP exposure promotes apoptosis in human pancreatic cells. PDX-1, a key gene in pancreatic development, regulates the expression of TFAM, a core regulator of mitochondrial function. This interaction triggers changes in MMP and mtDNA-cn, activates the PDX-1/TFAM/mtDNA axis, and ultimately leads to pancreatic cell injury.

Background Previous studies have found that exposure to benzo[a]pyrene (BaP) can lead to functional impairment of the human pancreas. Pancreatic and duodenal homeobox factor 1 (PDX-1) may play a role in regulating mitochondrial function. It is hypothesized that BaP exposure may interfere with PDX-1 expression in human pancreatic ductal epithelial cells (H6C7), thereby affecting mitochondrial transcription factor A (TFAM). This process could induce mitochondrial DNA (mtDNA) damage, disrupt pancreatic development and function, and elevate the risk of diabetes onset. Objective To investigate the mechanism of BaP-induced mtDNA damage through disruption of the PDX-1/TFAM pathway in a H6C7 cell model. Methods A H6C7 cell injury model was established using different concentrations of BaP. Cell viability was determined using cell counting kit-8 (CCK-8). After 24 h of BaP exposure (5,10, and 20 μmol·L⁻¹), cell morphological and mitochondrial membrane potential (MMP) changes were observed via confocalmicroscopy, and PDX-1/TFAM protein expression levels were assessed. Bioinformatics analysis combined with dual-luciferase reporter assays was used to confirm PDX-1 directly targeting the TFAM promoter. Following PDX-1 overexpression or silencing in BaP treated cells, flow cytometry was used to evaluate viability and apoptosis, while Western blot and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) measured PDX-1/TFAM expression and mitochondrial DNA copy number (mtDNA-cn). Results The cell injury model demonstrated that, compared with the control group, BaP exposure reduced cell viability, disrupted membrane integrity, induced nuclear fragmentation, and decreased MMP. Protein expression levels of PDX-1 and TFAM were significantly downregulated in the 10 and 20 μmol·L⁻¹ groups (P<0.05). Dual-luciferase reporter assays confirmed that PDX-1 overexpression upregulated TFAM levels. Flow cytometry revealed that PDX-1 overexpression significantly reduced apoptosis rate (P<0.001), whereas PDX-1 silencing increased apoptosis rate (P<0.001). Compared with the BaP-only group, BaP+PDX-1 overexpression elevated TFAM protein and mRNA expression as well as mtDNA-cn (P<0.01), while BaP+siRNA-PDX-1 suppressed these parameters (P<0.001). Conclusion BaP exposure promotes apoptosis in human pancreatic cells. PDX-1, a key gene in pancreatic development, regulates the expression of TFAM, a core regulator of mitochondrial function. This interaction triggers changes in MMP and mtDNA-cn, activates the PDX-1/TFAM/mtDNA axis, and ultimately leads to pancreatic cell injury.

OBJECTIVE To investigate the targeting effect of folic acid-modified crebanine nanoparticles （FA-Cre@PEG- PLGA NPs， hereinafter referred to as “NPs”） combined with ultrasound irradiation on M109 cells in vitro and in vivo after administration， and explore the anti-tumor mechanism. METHODS CCK-8 assay was used to detect the inhibitory effect of NPs combined with ultrasound irradiation on the proliferation of M109 cells， and the best ultrasound time was selected. Using human lung cancer A549 cells as a control， the targeting of NPs combined with ultrasound irradiation to M109 cells was evaluated by free folic acid blocking assay and cell uptake assay. The effects of NPs combined with ultrasound irradiation on the migration， invasion， apoptosis， cell cycle and reactive oxygen species （ROS） levels of M109 cells were detected by cell scratch test， Transwell chamber test and flow cytometry at 1 h after 958401536@qq.com administration； the changes of mitochondrial membrane potential （MMP） were observed by fluorescence inverted microscope. A mouse subcutaneous tumor model of M109 cells was constructed， and the in vivo tumor targeting of NPs combined with ultrasound irradiation was investigated by small animal in vivo imaging technology. RESULTS NPs combined with ultrasound irradiation could significantly inhibit the proliferation of M109 cells， and the optimal ultrasound time was 1 h after administration. The free folic acid could antagonize the inhibitory effect of NPs on the proliferation of M109 cells， and combined with ultrasound irradiation could partially reverse this antagonism. Compared with A549 cells， the uptake rate of NPs in M109 cells was significantly higher （P＜0.01）， and ultrasound irradiation could promote cellular uptake. NPs combined with ultrasound irradiation could inhibit the migration and invasion of M109 cells and block the cell cycle in the G0/G1 and G2/M phases. Compared with control group， the apoptosis rate of M109 cells and ROS level were increased significantly （P＜0.01）， while the MMP decreased significantly （P＜0.01） in the different concentration （100， 200， 300 μg/mL） groups of M109 cells. Compared with the mice in non-ultrasound group， the fluorescence intensity and tumor-targeting index of the tumor site in the 0 h ultrasound group were significantly enhanced （P＜0.05 or P＜0.01）. CONCLUSIONS NPs combined with ultrasound irradiation have a strong targeting effect on M109 cells in vitro and in vivo， the anti-tumor mechanism includes inhibiting cell migration and invasion， blocking cell cycle， and inducing apoptosis.

Immediate implant placement in the aesthetic zone has become increasingly widespread and has gradually evolved into a conventional techniques for implant procedures in the aesthetic region. To achieve favorable aesthetic and long-term outcomes, clinicians must possess extensive clinical experience as well as proficient surgical and restorative skills. This study summarizes the key factors influencing the long-term success of immediate implants in the aesthetic zone: strict adherence to the indications for immediate implant placement; thorough preoperative assessment of the patient’s systemic and local conditions, along with comprehensive evaluation of aesthetic risks; minimally invasive tooth extraction while preserving the integrity of the labial bone plate; selection of appropriately designed implants and their placement in an ideal three-dimensional position based on the implant’s characteristics; utilization of suitable bone and soft tissue augmentation techniques according to the patient’s specific hard and soft tissue anatomy, extent of bone defects, and periodontal phenotype; dynamic shaping of soft tissues through continuous adjustments in the emergence profile of provisional restorations; design of definitive restorations from the perspectives of health, function, and aesthetics; and implementation of regular follow-up and maintenance protocols after implant treatment, with increased emphasis on peri-implant care for patients who smoke, have diabetes, or undergo anti-osteoporosis therapy. This study proposes a decision-making framework to achieve long-term stable clinical outcomes with immediate implants in the aesthetic zone, providing a reference for clinicians in their clinical decision-making and treatment planning: ① for patients assessed as low aesthetic risk (e.g., thick gingival biotype, absence of hard and soft tissue defects, intact labial bone plate with thickness >1 mm, no acute infection), immediate implant placement after minimally invasive extraction is recommended, with the implant positioned in an ideal three-dimensional location, along with bone grafting in the gap between the implant and the labial bone plate and consideration of connective tissue grafting when required; ② for patients assessed as moderate aesthetic risk (e.g., thin gingival biotype, absence of soft tissue defects, intact labial bone plate but with thickness <1 mm or mild to moderate bone defects involving less than 50% height loss, chronic infection present), immediate implant placement with optimal three-dimensional positioning is feasible, accompanied by bone grafting in the implant-labial bone gap or external bone grafting on the labial aspect, with simultaneous or staged connective tissue grafting, or alternatively, use of the socket shield technique for immediate implant placement; ③ for patients assessed as high aesthetic risk (e.g., thin gingival biotype, presence of soft tissue defects, vertical bone deficiency, severe labial bone loss involving >50% height loss, acute infection present), ridge preservation followed by delayed implant placement is advised. By adhering to these treatment principles, immediate implant placement in the aesthetic zone can achieve reliable success rates and excellent aesthetic outcomes.

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder affecting a substantial proportion of women of reproductive age. It is frequently associated with ovulatory dysfunction, infertility, and an increased risk of chronic metabolic diseases. A hallmark pathological feature of PCOS is the arrest of follicular development, closely linked to impaired intercellular communication between the oocyte and surrounding granulosa cells. Transzonal projections (TZPs) are specialized cytoplasmic extensions derived from granulosa cells that penetrate the zona pellucida to establish direct contact with the oocyte. These structures serve as essential conduits for the transfer of metabolites, signaling molecules (e.g., cAMP, cGMP), and regulatory factors (e.g., microRNAs, growth differentiation factors), thereby maintaining meiotic arrest, facilitating metabolic cooperation, and supporting gene expression regulation in the oocyte. The proper formation and maintenance of TZPs depend on the cytoskeletal integrity of granulosa cells and the regulated expression of key connexins, particularly CX37 and CX43. Recent studies have revealed that in PCOS, TZPs exhibit significant structural and functional abnormalities. Contributing factors—such as hyperandrogenism, insulin resistance, oxidative stress, chronic inflammation, and dysregulation of critical signaling pathways (including PI3K/Akt, Wnt/β‑catenin, and MAPK/ERK)—collectively impair TZP integrity and reduce their formation. This disruption in granulosa-oocyte communication compromises oocyte quality and contributes to follicular arrest and anovulation. This review provides a comprehensive overview of TZP biology, including their formation mechanisms, molecular composition, and stage-specific dynamics during folliculogenesis. We highlight the pathological alterations in TZPs observed in PCOS and elucidate how endocrine and metabolic disturbances—particularly androgen excess and hyperinsulinemia—downregulate CX43 expression and impair gap junction function, thereby exacerbating ovarian microenvironmental dysfunction. Furthermore, we explore emerging therapeutic strategies aimed at preserving or restoring TZP integrity. Anti-androgen therapies (e.g., spironolactone, flutamide), insulin sensitizers (e.g., metformin), and GLP-1 receptor agonists (e.g., liraglutide) have shown potential in modulating connexin expression and enhancing granulosa-oocyte communication. In addition, agents such as melatonin, AMPK activators, and GDF9/BMP15 analogs may promote TZP formation and improve oocyte competence. Advanced technologies, including ovarian organoid models and CRISPR-based gene editing, offer promising platforms for studying TZP regulation and developing targeted interventions. In summary, TZPs are indispensable for maintaining follicular homeostasis, and their disruption plays a pivotal role in the pathogenesis of PCOS-related folliculogenesis failure. Targeting TZP integrity represents a promising therapeutic avenue in PCOS management and warrants further mechanistic and translational investigation.

AIM To investigate the effects of Xuesaitong Capsules(Panax notoginseng saponins)on ischemia/reperfusion injury in a mouse model of skin frostbite.METHODS The mice were randomly divided into the control group,the model group,the dexamethasone group(1 mg/kg),and the low-dose,medium-dose,and high-dose Xuesaitong Capsules groups(0.036,0.072,and 0.144 g/kg),with eight mice in each group.A frostbite model was established using a dry ice-cooled ceramic(ferrite)magnet.On the 2nd day after modeling,each group started its corresponding dosing by gavage for 14 consecutive days.The wound healing,histopathological changes,and serum levels of high-sensitivity C-reactive protein(hs-CRP),thromboxane B2(TXB2),6-keto-prostaglandin F1α(6-K-PGF1α),nitric oxide(NO)and endothelin(ET)were assessed using ELISA.The superoxide dismutase(SOD)activity and malondialdehyde(MDA)levels in skin tissues were measured biochemically.The protein expressions of tumor necrosis factor(TNF)-α,interleukin(IL)-1β,IL-6,Toll-like receptor(TLR)4 and phosphorylated nuclear factor-KB p65(p-NF-κB p65)in skin tissues were determined by Western blot.Additionally,LncRNA H19 mRNA expression in skin tissues was evaluated using RT-qPCR.RESULTS After the final administration,compared with the control group,the model group exhibited partial scab detachment,wound healing,and larger wound areas;hyperkeratosis with incomplete keratinization,detachment of the dermis and subcutaneous tissue,partial loss of appendages,subcutaneous edema,and dilated,congested,and hemorrhagic stromal vessels with extensive lymphocyte infiltration revealed by the histopathological examination;elevated serum levels of hs-CRP,TXB2,and ET(P＜0.05,P＜0.01);decreased 6-K-PGF1α and NO levels(P＜0.05,P＜0.01);reduced SOD activity in skin tissues(P＜0.01);increased MDA levels(P＜0.01);and upregulated protein expressions of TNF-α,IL-1β,IL-6,TLR4 and p-NF-κB p65,as well as LncRNA H19 mRNA expression(P＜0.05,P＜0.01).Compared with the model group,the group intervened with high-dose Xuesaitong Capsules displayed reduced wound areas(P＜0.01);decreased serum levels of hs-CRP,TXB2 and ET(P＜0.05,P＜0.01);increased 6-K-PGF1α and NO levels(P＜0.05,P＜0.01);enhanced SOD activity(P＜0.05,P＜0.01);reduced MDA level in skin tissues(P＜0.05,P＜0.01);and down-regulated TNF-α,IL-1β,IL-6,TLR4 and p-NF-κB p65 protein expressions and suppressed LncRNA H19 mRNA expression in skin tissues as well(P＜0.05,P＜0.01).CONCLUSION Xuesaitong Capsules alleviate ischemia/reperfusion injury in frostbite-injured mice by exerting anti-inflammatory and anti oxidative stress effects and restoring vascular endothelial function mediated by the downregulation of LncRNA H19 expression and inhibition of the TLR4/NF-κB signaling pathway.

Objective To evaluate the efficacy and safety of a novel intravascular lithotripsy(IVL)balloon—Vesscrack shockwave balloon—for vascular preparation before stent implantation in patients with severe coronary artery calcification(CAC).Methods This was a prospective,single-arm,multicenter study conducted in China from June 2022 to October 2022.Patients with severe CAC were treated with the Vesscrack shockwave balloon for lesion preparation,followed by drug-eluting stent(DES)implantation.Of these,33 patients underwent optical coherence tomography(OCT).The primary endpoint was procedural success,defined as successful stent implantation with residual stenosis≤30％and the absence of in-hospital major adverse events,including cardiac death,target vessel-related myocardial infarction,or target lesion revascularization.Results A total of 170 patients[mean age:(65.9±7.9)years,116 males]were enrolled.After treatment with IVL and DES,the minimum lumen diameter increased significantly compared to baseline[(2.34±0.40)mm vs.(0.95±0.33)mm,P＜0.001],the degree of stenosis was significantly reduced[(13.24±6.60)％vs.(65.18±10.59)％,P＜0.001].Procedural success was achieved in 100％of cases,and device success was 98.8％.The 30-day patient-related cardiovascular clinical composite endpoint(POCE)rate was 0.0,with no target lesion failure,no confirmed or potential thrombotic events were observed.The shockwave energy generator demonstrated excellent stability and ease of use.Among the 33 patients assessed with OCT,after IVL intervention,the maximum calcified area of the lumen[(3.51±1.51)mm2 vs.(2.85±1.80)mm2,P＜0.001],and the minimum lumen area within the target lesion[(3.08±1.04)mm2 vs.(2.02±0.75)mm2,P＜0.001],and after DES intervention,the luminal area of the largest calcified site[(6.59±1.64)mm2 vs.(2.85±1.80)mm2,P＜0.001]and the minimum luminal area within the target lesion[(6.19±1.45)mm2 vs.(2.02±0.75)mm2,P＜0.001]were significantly increased,and the differences were statistically significant.Conclusions The Vesscrack shockwave balloon is effective and safe for vascular preparation in patients with severe CAC prior to stent implantation.It achieves significant calcified plaque modification,high procedural success rates,and minimal complications.

Objective To explore the long-term efficacy of percutaneous pulmonary valve implantation(PPVI)and the durability of the domestic self-expanding Venus P valve.Methods A total of 8 patients with post-surgical right ventricular outflow tract(RVOT)dysfunction,who were admitted to hospital from October 2014 to July 2016 and deemed anatomically suitable for PPVI with self-expanding valve,were included prospectively.Clinical,imaging,procedural and follow-up data were analyzed.The survival rates,perioperative and long-term complication rates,long-term efficacy of PPVI,and long-term function of Venus P in 8 patients were evaluated.The immediate procedural results were evaluated by clinical implant success rate,which is defined as successful valve implantation with echocardiography-assessed pulmonary regurgitation＜moderate and peak trans-pulmonary pressure gradient＜40 mmHg.Results A total of 8 patients were included,with 7 females,aged 14 to 36 years.The initial diagnosis included post-surgical Tetralogy of Fallot(5 cases),post-surgical Trilogy of Fallot(1 case),post-surgical Quadricuspid pulmonary valve stenosis(1 case)and post-surgical Double-Outlet Right Ventricle(1 case).The indications of PPVI included RVOT-pulmonary obstruction and regurgitation(1 case)and isolated regurgitation(7 cases).Clinical implant success was achieved in all of the 8 patients with firmly fixed valve,and there were no such complications as valve detachment,displacement or stent fracture.All patients experienced significant symptom relief after the procedure.The right ventricular end-diastolic volume index(RVEDVi)measured by CMR 6 months after PPVI showed a significant decrease compared to preprocedural values[(89.99±13.85)ml/m2 vs.(144.93±11.28)ml/m2,P=0.001].Postoperative pulmonary regurgitation were significantly improved or disappeared in all patients,and there was no statistically significant difference in the average peak pressure gradient measured by echocardiogram between preoperative and the latest follow-up[(23.25±8.39)mmHg vs.(18.75±6.28)mmHg,P=0.210].Over an average follow-up period of(9.25±0.71)years,1 case of infective endocarditis occurred 5 years after PPVI.During the follow-up,no death,deterioration of heart failure,malignant arrhythmia or other serious complications were observed.All patients completed 8-year follow-up,and 3 completed 10-year follow-up.All patients were graded as NYHA functional class one at the latest follow-up.Conclusions PPVI using the domestically produced self-expanding Venus P is safe and feasible for the treatment of patients with post-surgical RVOT dysfunction and suitable anatomy.Our study confirms the long-term efficacy and durability of Venus P from multiple perspectives,and no severe stent fracture occurred without pre-stent implantation in the native RVOT.

Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.