Objective:To analyze the target signaling pathway of histone H3K27 methylation-induced podocyte injury, verify the regulatory effect of histone H3K27 methylation on podocyte injury in focal segmental glomerulosclerosis (FSGS) mice through target signaling pathway, and explore the mechanism of abnormal methylation of histone H3K27-induced podocyte injury in FSGS mice.Methods:(1) Cell experiments: primary cultured immortalized mouse podocytes MPC5 were cultured in vitro, and divided into control group, adriamycin (ADR) group, ADR+GSK-J4 (histone demethylase, KDM6B inhibitor) group, ADR+coumarin A1 (C-A1, JAK2 agonist) group and ADR+GSK-J4+C-A1 group. The transmission electron microscope was used to observe ultrastructure of podocytes. Immunofluorescence was used to detect the protein expression of H3K27me3 and nephrin in podocytes. The whole genome sequence of podocytes was obtained, the differentially expressed genes were screened, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used for enrichment analysis. Real time-quantitative PCR and Western blotting were used to detect the gene and protein expression of JAK2-STAT3 signaling pathway in podocytes respectively. Enzyme-linked immunosorbent assay was used to detect interleukin 6 (IL-6), monocyte chemotactic protein 1 (MCP-1), α-smooth muscle actin (α-SMA) and transforming growth factor β1 (TGF-β1). (2) Animal experiments: EZH2 gene knock out ( EZH2podKo)-FSGS (tail vein injection of ADR) mouse models were established, and divided into EZH2ctrl+control group ( n=20), EZH2ctrl+FSGS ( n=20), EZH2podKo+control group ( n=30) and EZH2podKo+FSGS group ( n=30). HE staining was used to observe the morphology of kidney tissues. Immunohistochemistry was used to detect the H3K27me3 protein expression in podocytes. Real time-quantitative PCR and Western blotting were used to verify the gene and protein expression of JAK2-STAT3 signaling pathway respectively. Enzyme-linked immunosorbent assay was used to detect IL-6, MCP-1, α-SMA and TGF-β1 of kidney tissues. Results:(1) Cell experiments: Compared with control group, the nucleus shrank and ruptured, the cytoplasm showed vacuole, and mitochondria and endoplasmic reticulum swelled in ADR group, which verified that the podocyte injury model of ADR nephropathy was successfully established. Compared with control group, the protein expression level of H3K27me3 in ADR group was significantly lower ( P<0.05). Compared with ADR group, the protein expression level of H3K27me3 in podocytes in ADR+GSK-J4 group was significantly higher ( P<0.05), and there were 502 increased genes and 443 decreased genes. GO enrichment analysis showed that the differentially enriched peaks were mainly in ribonucleoprotein complex biogenesis, ribosome biogenesis, establishment of protein localization to organelle, and involved in regulation of receptor signaling pathway via JAK-STAT and receptor signaling pathway via JAK-STAT. Differential expressed genes were Irf1, Tnfrsf1a, S ocs1, Notch1, Gadd45a, Hes1 and Socs3, involving in the regulation of JAK-STAT signaling pathway. KEGG enrichment analysis showed that the differentially enriched peaks were mainly in amyotrophic lateral sclerosis, and the target genes were Mcl1, Egfr, Socs1, Cdkn1a, Pdgfa and Socs3, involving in the regulation of JAK-STAT signaling pathway. Compared with ADR group, the mRNA and protein expression levels of JAK2 and STAT3 in the ADR+GSK-J4 group were significantly lower, and the downstream inflammatory factors of IL-6, MCP-1 and α-SMA were significantly higher (all P<0.05). Compared with ADR group, the protein expression level of nephrin in ADR+GSK-J4 group was higher ( P<0.05), and the protein expression level of nephrin in ADR+C-A1 group was lower ( P<0.05). Compared with ADR+GSK-J4 group, the protein expression level of nephrin in ADR+GSK-J4+C-A1 group was lower ( P<0.05). (2) Animal experiments: Compared with EZH2ctrl+FSGS group, EZH2podKo+FSGS group showed obvious renal tissue damage, matrix hyperplasia in mesangial area with massive homogeneous substance deposition, apoptosis and necrosis of renal tubular epithelial cells, obvious thickening and extensive fusion of glomerular epithelial cells, basement membrane collapse, and compression and narrowing of capillary structure. Compared with EZH2ctrl+FSGS group, the protein expression level of H3K27me3 in EZH2podKo+FSGS group was significantly lower, and the mRNA and protein expression levels of JAK2 and STAT3, and the levels of IL-6, MCP-1, α-SMA and TGF-β1 were higher (all P<0.05). Conclusions:Abnormal methylation modification of H3K27 leads to change of target gene expression, activation of JAK2-STAT3 signaling pathway, podocyte injury, glomerulosclerosis and renal tubular injury, participating in the development of FSGS.

Objective:To investigate the clinical characteristics and independent risk factors of severe disease in patients with anti-nuclear matrix protein (NXP) 2 antibody-positive juvenile dermatomyositis (JDM).Methods:A retrospective cohort study was conducted, including 219 anti-NXP2 antibody-positive JDM patients admitted to 23 children′s hospitals across China from July 2011 to July 2023. Patients were classified into severe and non-severe groups based on classification criteria for severe dermatomyositis. Demographic characteristics, clinical manifestations, and laboratory parameters were compared between the 2 groups using independent sample t-test, Mann-Whitney U test, or χ2 test. Univariate and multivariate Logistic regression analyses were performed to identify risk factors for severe disease. The receiver operating characteristic curve was employed to calculate optimal cut-off values. Results:Among the 219 patients, 108 were male and 111 were female, with an age at onset of 6.3 (3.5, 9.4) years. The severe group comprised 69 patients, and the non-severe group 150 patients. The severe group had significantly higher rates of fever, heliotrope rash, subcutaneous edema, periorbital edema, anti-Ro52 antibody positivity, as well as elevated levels of ferritin-to-albumin ratio (FAR), creatine kinase (CK), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) (all P<0.05). Multivariate analysis identified anti-Ro52 antibody positivity ( OR=13.26, 95% CI 1.37-128.29) and elevated FAR ( OR=1.90, 95% CI 1.09-2.31) as independent risk factors for severe anti-NXP2 antibody-positive JDM (both P<0.05). Receiver operating characteristic curve analysis revealed that a FAR cutoff value of 6.82 predicted severe disease with an area under the curve of 0.87 (95% CI 0.81-0.94, P<0.001), sensitivity of 0.85, and specificity of 0.70. All patients received glucocorticoid therapy, and the severe group received higher proportions of steroid pulse therapy, cyclophosphamide, mycophenolate mofetil, intravenous immunoglobulin, biologics, and adjuvant treatments compared to the non-severe group (all P<0.05). In terms of outcomes, 2 patients (2.9%) in the severe group died (due to neurological involvement and intestinal perforation, respectively), while the remaining patients achieved complete clinical response or remission. All patients in the non-severe group achieved remission. Conclusions:The primary clinical features of anti-NXP2 antibody-positive JDM included fever, heliotrope rash, subcutaneous edema, periorbital edema, anti-Ro52 antibody positivity, and elevated levels of CK, AST, LDH, and FAR. Furthermore, anti-Ro52 antibody positivity and a FAR>6.82 were identified as independent risk factors.

A 62-year-old male, was admitted to the hospital, with a chief complaint of fever lasting over 10 days and leukopenia and thrombocytopenia for 2 days. Ten days prior to admission, the patient experienced intermittent fever without obvious incentive factors. The breath sounds in both lungs were coarse, without accompanying dry or moist rales. Color Doppler Ultrasound indicated mild splenomegaly and multiple lymphadenectasis in the bilateral cervical, axillary, and inguinal regions. Morphological examination of bone marrow cells demonstrated abnormally large blasts, with some of the nuclei being rather irregular and cytoplasmic vacuoles. Immunophenotyping results identified this group of blast cells as immature monocytes. Karyotype analysis of chromosomes showed clonal abnormalities, with 19 out of 20 cells exhibiting near-tetraploid karyotypes, including complex karyotypic abnormalities involving chromosome17.Targeted next-generation sequencing (NGS) detected gene mutations associated with hematological malignancies that have definite or potential clinical significance,including TP53, SRSF2, STAG2, and ARID2, with variant allele frequencies (VAF) of 63.10%, 30.30%, 0.80%, and 0.60%, respectively. Integrating laboratory findings, the diagnosis was diagnosed as AML-M5 at high-risk. After receiving chemotherapy with the regimen of azacitidine combined with venetoclax, the patient passed away more than 20 days later.

Objective:To investigate the clinical and genetic variation characteristics of a child with autosomal dominant lateral temporal lobe epilepsy caused by de novo variation of the MICAL1 gene. Methods:Clinical data of the patient with autosomal dominant lateral temporal lobe epilepsy caused by MICAL1 gene variation diagnosed in Children′s Hospital of Soochow University in August 2019 were collected. The whole exome sequencing was performed on the core members of the family, and the characteristics of gene variations were analyzed. Results:The proband, a 10 years and 5 months old boy, was admitted to the hospital because of "intermittent convulsions for 7 years". The clinical manifestations included focal or generalized tonic-clonic seizures and hearing aura, with normal language and intellectual development. No abnormalities were found in the T 1 and fluid attenuated inversion recovery sequences of the cranial 3.0 T magnetic resonance imaging and 3D thin-slice magnetic resonance imaging.Long-range video electroencephalogram showed the distribution of spinous and slow spinous waves in the left frontal and temporal areas. The results of whole exome gene sequencing in the core family members showed heterozygous de novo missense variation in the MICAL1 gene of the proband (NM_022765): c.763G>T(exon6)(p.Val255Leu) that had not been reported. According to American College of Medical Genetics and Genomics and Association for Molecular Pathology guidelines (2015), the mutation was considered potentially pathogenic. The application of antiepileptic drugs was effective in controlling epileptic seizures. Conclusions:Auditory symptoms are main clinical manifestations for the child with autosomal dominant lateral temporal lobe epilepsy. Antiepileptic drugs can effectively control epileptic seizures of the child, and the MICAL1 gene c.763G>T (p.Val255Leu) mutation is the genetic cause of the proband.

Objective:To summarize the clinical characteristics of 5 children with developmental epileptic encephalopathy type 17 (DEE17) caused by GNAO1 gene variants confirmed by whole-exome sequencing and analyze the features of their genetic variants. Methods:A retrospective analysis was conducted on the clinical data of 5 children diagnosed with GNAO1-related DEE17 in the Department of Neurology, Children′s Hospital of Soochow University from January 2019 to October 2024. Their clinical features, genetic testing results, neuroimaging findings, electroencephalogram (EEG) results, and treatment regimens were summarized. Follow-up was performed via telephone or outpatient visits. Results:Among the 5 diagnosed children (3 males, 2 females), the age of onset ranged from 2 days to 2 years, and the age at diagnosis ranged from 2 days to 6 years. Four children presented with seizures in the neonatal or infantile period, manifesting as hypotonia, developmental delay, and seizure types including generalized tonic-clonic, myoclonic, and epileptic spasms. One child had a later onset at 2 years, presenting with language delay, intellectual disability, and involuntary movements, followed by seizures at 6 years, including focal and generalized tonic-clonic seizures. Genetic testing revealed de novo heterozygous missense variants in GNAO1 in all 5 cases: c.119G>C (p.G40A), c.808A>C (p.N270H), c.808A>G (p.N270D), c.118G>C (p.G40R), and c.17G>T (p.S6I). Among these variants, c.119G>C and c.17G>T were previously unreported pathogenic variants. Neuroimaging showed nonspecific changes in 3 children (widened frontal-temporal subarachnoid space, delayed myelination) and abnormal white matter signals in 2 cases. Long-term video-EEG revealed abnormal discharges and background slowing in all cases: multifocal discharges in 4 cases and focal epileptiform discharges (left mid-temporal) in 1 case. Clinical seizures were captured in 3 cases: 1 with a burst-suppression pattern and 2 with hypsarrhythmia. All patients received 3 or more antiseizure medications. Four cases (cases 1-4) responded well to topiramate combination therapy, with 2 cases (cases 1, 2) achieving complete seizure freedom and 2 cases (cases 3, 4) experiencing more than a 50% reduction in seizures. One child (case 3) achieved seizure control with an adjunctive ketogenic diet. The late-onset case (case 5) required a combination of levetiracetam, oxcarbazepine, and valproate for seizure management. Conclusions:GNAO1 variants can lead to DEE17 with diverse seizure types, often requiring multiple antiseizure medications, among which topiramate is effective. Early-onset cases typically present with seizures and developmental delay, while late-onset cases may exhibit language delay, intellectual disability, movement disorders, and refractory epilepsy. Genetic testing should be performed early for timely diagnosis.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

Objective To understand the changing composition and antibiotic resistance of bacterial species in the clinical isolates from outpatient and emergency department(hereinafter referred to as outpatients)and inpatient children over time in various hospitals,and to provide laboratory evidence for rational antibiotic use.Methods The data on clinically isolated pathogenic bacteria and antimicrobial susceptibility of isolates from outpatients and inpatient children in the CHINET program from 2015 to 2021 were collected and analyzed.Results A total of 278 471 isolates were isolated from pediatric patients in the CHINET program from 2015 to 2021.About 17.1％of the strains were isolated from outpatients,primarily group A β-hemolytic Streptococcus,Escherichia coli,and Staphylococcus aureus.Most of the strains(82.9％)were isolated from inpatients,mainly SS.aureus,E.coli,and H.influenzae.The prevalence of methicillin-resistant S.aureus(MRSA)in outpatients(24.5％)was lower than that in inpatient children(31.5％).The MRSA isolates from outpatients showed lower resistance rates to the antibiotics tested than the strains isolated from inpatient children.The prevalence of vancomycin-resistant Enterococcus faecalis or E.faecium and penicillin-resistant S.pneumoniae was low in either outpatients or inpatient children.S.pneumoniae,β-hemolytic Streptococcus and S.viridans showed high resistance rates to erythromycin.The prevalence of erythromycin-resistant group A β-hemolytic Streptococcus was higher in outpatients than that in inpatient children.The prevalence of β-lactamase-producing H.influenzae showed an overall upward trend in children,but lower in outpatients(45.1％)than in inpatient children(59.4％).The prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKpn),carbapenem-resistant Pseudomonas aeruginosa(CRPae)and carbapenem-resistant Acinetobacter baumannii(CRAba)was 14％,11.7％,47.8％in outpatients,but 24.2％,20.6％,and 52.8％in inpatient children,respectively.The prevalence of multidrug-resistant E.coli,K.pneumoniae,Proteus mirabilis,P.aeruginosa and A.baumannii strains was lower in outpatients than in inpatient children.The prevalence of fluoroquinolone-resistant E.coli,ESBLs-producing K.pneumoniae,ESBLs-producing P.mirabilis,carbapenem-resistant E.coli(CREco),CRKpn,and CRPae was lower in children in outpatients than in inpatient children,but the prevalence of CRAba in 2021 was higher than in inpatient children.Conclusions The distribution of clinical isolates from children is different between outpatients and inpatients.The prevalence of MRSA,ESBL,and CRO was higher in inpatient children than in outpatients.Antibiotics should be used rationally in clinical practice based on etiological diagnosis and antimicrobial susceptibility test results.Ongoing antimicrobial resistance surveillance and prevention and control of hospital infections are crucial to curbing bacterial resistance.

Objective To investigate the changing antibiotic resistance profiles of E.coli isolated from patients in the 52 hospitals participating in the CHINET program from 2015 to 2021.Methods Antimicrobial susceptibility was tested for clinical isolates of E.coli according to the unified protocol of CHINET program.WHONET 5.6 and SPSS 20.0 software were used for data analysis.Results Atotal of 289 760 nonduplicate clinical strains ofE.coli were isolated from 2015 to 2021,mainly from urine samples(44.7±3.2)％.The proportion of E.coli strains isolated from urine samples was higher in females than in males(59.0％vs 29.5％).The proportion of E.coli strains isolated from respiratory tract and cerebrospinal fluid samples was significantly higher in children than in adults(16.7％vs 7.8％,0.8％vs 0.1％,both P＜0.05).The isolates from internal medicine department accounted for the largest proportion(28.9±2.8)％with an increasing trend over years.Overall,the prevalence of ESBLs-producing E.coli and carbapenem resistant E.coli(CREco)was 55.9％and 1.8％,respectively during the 7-year period.The prevalence of ESBLs-producing E.coli was the highest in tertiary hospitals each year from 2015 to 2021 compared to secondary hospitals.The prevalence of CREco was higher in children's hospitals compared to secondary and tertiary hospitals each year from 2015 to 2021.The prevalence of ESBLs-producing E.coli in tertiary hospitals and children's hospitals and the prevalence of CREco in children's hospitals showed a decreasing trend over the 7-year period.The prevalence of CREco in secondary and tertiary hospitals increased slowly.Antibiotic resistance rates changed slowly from 2015 to 2021.Carbapenem drugs(imipenem,meropenem)were the most active drugs amongβ-lactams against E.coli(resistance rate≤2.1％).The resistance rates of E.coli to β-lactam/β-lactam inhibitor combinations(piperacillin-tazobactam,cefoperazone-sulbactam),aminoglycosides(amikacin),nitrofurantoin and fosfomycin(for urinary isolates only)were all less than 10％.The resistance rate of E.coli strains to antibiotics varied with the level of hospitals and the departments where the strains were isolated,especially for cefazolin and ciprofloxacin,to which the resistance rate of E.coli strains from children in non-ICU departments was significantly lower than that of the strains isolated from other departments(P＜0.05).The E.coli isolates from ICU showed higher resistance rate to most antimicrobial agents tested(excluding tigecycline)than the strains isolated from other departments.The E.coli strains isolated from tertiary hospitals showed higher resistance rates to the antimicrobial agents tested(excluding tigecycline,polymyxin B,cefepime and carbapenems)than the strains from secondary hospitals and children's hospitals.Conclusions E.coli is an important pathogen causing clinical infection.More than half of the clinical isolates produced ESBL.The prevalence of CREco is increasing in secondary and tertiary hospitals over the 7-year period even though the overall prevalence is still low.This is an issue of concern.

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.