Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

Objective:To investigate the clinicopathological features, immunophenotype, diagnosis and differential diagnosis of SRF-rearranged cellular perivascular myoid tumor.Methods:Two cases of SRF-rearranged cellular perivascular myoid tumor diagnosed in the Department of Pathology, Fudan University Shanghai Cancer Center from October 2021 to March 2022 were collected. Immunohistochemical staining, fluorescence in-situ hybridization (FISH) and next-generation sequencing (NGS) were performed, and the literature was reviewed.Results:Case 1, a 3-month-old boy presented with a painless tumor of the scalp, measuring about 2 cm in diameter. Case 2, a 3-year-old girl complained with a painless tumor of the knee, measuring approximately 1.5 cm in diameter. Microscopically, the tumor had a clear boundary and showed multinodular growth. The tumor was mainly composed of spindle cells arranged in long intersecting fascicles associated with thin, slit-like or branching ectatic vessels, focally forming hemangiopericytoma-like appearance. The tumor cells were abundant, but there was no obvious atypia. Mitotic figures (3-4/10 HPF) were noted. H-caldesmon and SMA were positive in both cases. Case 1 showed diffuse and strong positivity for Desmin, and focally for CKpan. Ki-67 proliferation index was 20% and 30%, respectively. FISH displayed NCOA2 gene translocation in case 1 and the RELA gene translocation in case 2. NGS detected the SRF-NCOA2 gene fusion in case 1 and the SRF-RELA gene fusion in case 2. Both patients underwent local excisions. During the follow-up of 5-14 months, case 1 had no local recurrence, while case 2 developed local recurrence 1 year post operatively.Conclusions:SRF-rearranged cellular perivascular myoid tumor is a novel variant of perivascular cell tumor, which tends to occur in children and adolescents. The tumor forms a broad morphologic spectrum ranging from a pericytic pattern to a myoid pattern, and include hybrid tumors with a mixture of pericytic and myoid patterns. Due to its diffuse hypercellularity and increased mitotic figures and smooth muscle-like immunophenotype, the tumor is easy to be misdiagnosed as myogenic sarcomas. The tumor usually pursues a benign clinical course and rare cases may locally recur.

Objective To investigate the influences and mechanism of X chromosome inactivation specific transcript(XIST)on the proliferation and extracellular matrix synthesis of nucleus pulposus cells in rats with intervertebral disc degeneration(IDD).Methods SD rat intervertebral disc nucleus pulposus cells were isolated and cultured in vitro,and then randomly divided cells into control group,model group,XIST knockdown group,empty plasmid group,and XIST knockdown+miR-132-3p knockdown group.Except for control group,the cells in other groups were induced by interleukin(IL)-1β to establish IDD models.After nucleus pulposus cells were grouped and treated,the expressions of XIST and miR-132-3p in the nucleus pulposus cells of rats were detected by qRT-PCR;the proliferation of intervertebral disc nucleus pulposus cells was detected by MTS method and EdU staining;ELISA was used to measure the levels of inflammatory factors IL-6 and IL-18 in the intervertebral disc nucleus pulposus cells;Immunoblotting was used to detect the expression of extracellular matrix labeled proteins Collagen Ⅱ and Aggrecan in rat nucleus pulposus cells.The targeted regulation of miR-132-3p by XIST in rat nucleus pulposus cells was detected by dual-luciferase reporter gene assay.IDD rat models were established by intramuscular injection of IL-1β and divided into sham operation group,model group,XIST knockdown group,no-load plasmid group,XIST knockdown+miR-132-3p knockdown group,with 12 rats in each group.After treatment in each group,the expressions of XIST and miR-132-3p in intervertebral disc tissues were detected by qRT-PCR;TUNEL staining was used to detect apoptosis of nucleus pulposus cells in intervertebral disc tissue of rats;the morphology of intervertebral disc cartilage was observed by saffron O staining;serum levels of inflammatory factors IL-6 and IL-18 were determined by ELISA;the expressions of Collagen Ⅱ and Aggrecan in intervertebral disc tissues were detected by Western blotting.Results Compared with control group(cells)/sham operation group(rats),XIST expression in intervertebral disc tissue and nucleus pulposus cells,apoptosis rate of intervertebral disc nucleus pulposus cells,levels of inflammatory factors IL-6 and IL-18 in intervertebral disc nucleus pulposus cells culture medium and serum were increased in model group(P＜0.05),the activity and proliferation rate of nucleus pulposus cells and the expressions of miR-132-3p,Collagen Ⅱ and Aggrecan protein in nucleus pulposus cells and intervertebral disc tissues decreased(P＜0.05);compared with model group,the apoptosis rate of nucleus pulposus cells,the levels of inflammatory factors IL-6 and IL-18 in intervertebral disc nucleus pulposus cells culture medium and serum,and the expression of XIST in nucleus pulposus cells and intervertebral disc tissues of rats in XIST knockdown group decreased(P＜0.05),the activity and proliferation rate of nucleus pulposus cells and the expressions of miR-132-3p,Collagen Ⅱ and Aggrecan protein in nucleus pulposus cells and intervertebral disc tissues increased(P＜0.05).Down-regulation of miR-132-3p attenuates the ameliorative effect of knockdown XIST on IL-1β-induced intervertebral disc injury and cartilage matrix loss.XIST was able to target and down-regulate the expression of miR-132-3p in rat nucleus pulposus cells.Conclusion Knockdown of XIST can inhibit inflammation by up-regulating miR-132-3p,thereby inhibiting the apoptosis of IDD nucleus pulposus cells and promoting their proliferation and extracellular matrix synthesis.

The basic structure and principle of the reverse osmosis water treatment system were described briefly.Three common faults of the system were explored in terms of cause and solution.References were provided for medical engineers to treat similar faults.[Chinese Medical Equipment Journal,2024,45(5):118-120]

Coronary perforation is when a contrast agent or blood flows outside a blood vessel through a tear in a coronary artery.In this case,we reported a case of percutaneous coronary intervention for coronary calcified lesions,which led to iatrogenic coronary perforation and cardiac tamponade after the use of Shockwave balloon to treat intracoronary calcified nodules,and the management of PCI-related CAP was systematically reviewed through the literature.

Objective To verify the safety and efficacy of a new portable extracorporeal membrane oxygenation(ECMO)system(Xijing Advanced Life Support System JC-Ⅲ)in large animals.Methods A total of 10 healthy small fat-tail sheep underwent veno-arterial extracorporeal membrane oxygenation(VA-ECMO)support by carotid arterial-jugular catheterization to evaluate the performance of the JC-Ⅲ ECMO system.Systemic anticoagulation was achieved by continuous infusion of heparin.Active coagulation time(ACT)was recorded every 2 hours during the experiment,and the ACT was maintained between 200-250 s.Centrifugal pump speed is set at 3 000-3 500 r/min.The changes of hemoglobin,blood cell counts,hematocrit,liver and kidney function were monitored before and 24 h after ECMO initiation,respectively.After the experiment,the pump and oxygenator were dissected to probe the thrombosis.Results The success rate of VA-ECMO operation was 100％,and there was no hemolysis,pump thrombosis and oxygenator thrombosis after 24 h of ECMO.Before and after the operation,there were no significant changes in indicators such as hemoglobin content,white blood cell counts,platelet counts,alanine aminotransferase concentration,aspartate aminotransferase concentration,urea,creatinine,high-sensitivity troponin Ⅰ,and N-terminal pro-brain natriuretic peptide(all P＞0.05).Conclusions This in vivo study confirms that Xijing Advanced Life support System JC-Ⅲ is safe and effective.

Objective To monitor the antifungal resistance of clinical isolates of Candida spp.in the East China region.Methods MALDI-TOF MS or molecular methods were used to re-identify the strains collected from January 2018 to December 2022.Antifungal susceptibility testing was performed using the broth microdilution method.The susceptibility test results were interpreted according to the breakpoints of 2022 Clinical and Laboratory Standards Institute(CLSI)documents M27 M44s-Ed3 and M57s-Ed4.Results A total of 3 026 strains of Candida were collected,65.33％of which were isolated from sterile body sites,mainly from blood(38.86％)and pleural effusion/ascites(10.21％).The predominant species of Candida were Candida albicans(44.51％),followed by Candida parapsilosis complex(19.46％),Candida tropicalis(13.98％),Candida glabrata(10.34％),and other Candida species(0.79％).Candida albicans showed overall high susceptibility rates to the 10 antifungal drugs tested(the lowest rate being 93.62％).Only 2.97％of the strains showed dose-dependent susceptibility(SDD)to fluconazole.Candida parapsilosis complex had a SDD rate of 2.61％and a resistance rate of 9.42％to fluconazole,and susceptibility rates above 90％to other drugs.Candida glabrata had a SDD rate of 92.01％and a resistance rate of 7.99％to fluconazole,resistance rates of 32.27％and 48.24％to posaconazole and voriconazole non-wild-type strains(NWT),respectively,and susceptibility rates above 90％to other drugs.Candida tropicalis had resistance rates of 29.55％and 26.24％to fluconazole and voriconazole,respectively,resistance rates of 76.60％and 21.99％to posaconazole and echinocandins non-wild-type strains(NWT),and a resistance rate of 2.36％to echinocandins.Conclusions The prevalence and species distribution of Candida spp.in the East China region are consistent with previous domestic and international reports.Candida glabrata exhibits certain degree of resistance to fluconazole,while Candida tropicalis demonstrates higher resistance to triazole drugs.Additionally,echinocandins resistance has emerged in Candida albicans,Candida glabrata,Candida tropicalis,and Candida parapsilosis.

Aim To explore the protective effect of an-thocyanin B2(PCB2)on hydrogen peroxide(H2O2)induced oxidative damage and apoptosis in human oli-godendrocytes(MO3.13)and the underlying mecha-nism.Methods The optimal concentration of H2O2 and PCB2 for action was screened,and divided into normal group,PCB2 group(100 mg·L-1 PCB2 treat-ment for 24 hours),H2 O2 model group(500 μmol·L-1 H2O2 treatment for 24 hours),and H2O2+PCB2 group(500 μmol·L-1 H2O2 and 100 mg·L-1 PCB2 co-treated for 24 hours).FRAP method was used to detect the antioxidant capacity of PCB2;CCK-8 meth-od was used to detect the survival rate of cells in each group,while LDH method was used to assess cytotoxic-ity.Microenzyme-linked immunosorbent assay and ELISA were used to examine the levels of LDH,NO,H2O2,as well as the activities of CAT and SOD in each group of cells.Immunofluorescence and Western blot were used to detect the protein expression levels of NRF2,xCT,HO-1,ferritin,and GPX4 in each group of cells.FerroOrange fluorescent probe was used to de-tect the intracellular content of ferrous ions(Fe2+).Results H2O2 could induce MO3.13 oxidative dam-age and lead to cell ferroptosis,while PCB2 could alle-viate MO3.13 oxidative damage and ferroptosis.Com-pared with the H2O2 model group,PCB2 intervention could significantly increase LDH content in MO3.13,reduce NO and H2O2 content,and improve SOD and CAT activity,and up-regulate the protein expression levels of NRF2,xCT,HO-1,ferritin,and GPX4.Conclusion PCB2 can enhance cellular antioxidant capacity and alleviate H2O2 induced MO3.13 oxidative damage through the NRF2/HO-1/xCT/GPX4 axis.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.