Multidrug-resistant (MDR) bacterial infections have emerged as a serious challenge of global public health crisis. The overuse and misuse of conventional antibiotics have dramatically accelerated the emergence, evolution and worldwide spread of drug-resistant bacterial strains, necessitating urgent exploration of novel antibacterial strategies. Bacteriophages serve as natural bacterial predators offering distinct advantages including high host specificity, autonomous self-replication capabilities and cost-effective large-scale production. However, wild-type phages present significant clinical limitations due to their narrow host ranges, susceptibility to rapid immune clearance and poor penetration of bacterial biofilms, which severely restrict their therapeutic applications. The convergence of synthetic biology, nanotechnology and advanced gene editing technologies has accelerated the development of engineered bacteriophage platforms, providing programmable, scalable and clinically translatable pathways to overcome these inherent biological constraints. Here, we systematically delineate four fundamental strategies for engineered bacteriophage development. Chemical modification utilizes reactive functional groups such as amino, carboxyl and thiol moieties on capsid proteins through esterification, amidation or click chemistry reactions to achieve precise drug conjugation and surface functionalization. In vivo editing encompasses ultraviolet or chemical mutagenesis for random mutation induction, homologous recombination for targeted genetic alterations, recombineering methodologies including electroporation-mediated bacteriophage recombination engineering, and CRISPR-Cas systems for precise genome editing to enable exact genetic reconstruction and host range reprogramming. In vitro synthesis leverages genome engineering platforms where intact phage genomes are transferred into yeast or host bacteria to facilitate highly efficient homologous recombination, enabling large DNA fragment assembly and cross-gene host range expansion without bacterial toxicity constraints. Directed evolution combines artificial selection through mutation library screening with rational design approaches involving chimeric receptor binding protein construction or site-specific mutagenesis, effectively balancing the discovery of unknown adaptive pathways with targeted host specificity modification. Moreover, we comprehensively discuss therapeutic applications across diverse clinical scenarios. Engineered bacteriophage effectively disrupt bacterial biofilms through sophisticated functionalized delivery platforms including nanozyme-conjugated phages, phage-liposome nanoconjugates and bio-responsive hydrogels, demonstrating significantly enhanced bactericidal efficiency compared to unmodified free phages. These bioengineered vectors attenuate bacterial virulence and resensitize pathogens to antibiotics by delivering CRISPR-Cas systems or base editors to disrupt critical virulence factors such as pili, capsule synthesis machineries and quorum sensing systems, or by inactivating antibiotic resistance determinants including beta-lactamase genes. As an intelligent nanomedicine delivery platform, engineered bacteriophage enable precise pathogen elimination an through photocatalytic reactive oxygen species generation, immunomodulatory interventions, or controlled release of antibacterial drugs. Furthermore, oral administration of engineered bacteriophage facilitates microbiota modulation, which selectively eliminate intestinal pathogens while preserve beneficial commensal microbiota, thereby restoring microbial community balance and preventing complications associated with dysbiosis. Finally, we critically analyze persistent challenges including host strain matching complexity, evolution of bacterial resistance mechanisms, pharmacokinetic optimization requirements, optimal administration route selection, large-scale production quality control standards and clinical dosing determination protocols. Through multidisciplinary integration of synthetic biology, infectious disease medicine and immunology, future translational medicine studies of bacteriophage should establish comprehensive technical platforms encompassing rapid phage screening, intelligent rational design, rigorous in vivo evaluation and standardized clinical validation processes, ultimately advancing engineered bacteriophage from laboratory innovations to clinically approved therapeutics for effectively combating MDR bacterial infections.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

Tricuspid regurgitation(TR)is a common heart valve disease.According to the pathogenesis,TR can be divided into primary(organic)and secondary(functional)regurgitation,of which functional TR accounts for more than 90%.Patients with severe TR have poor prognosis and poor drug treatment,and surgery(valvuloplasty)is the main treatment.At present,transcatheter edge-to-edge tricuspid valve repair(T-TEER)has become an essential program of transcatheter treatment for TR,providing minimally invasive treatment for TR patients who cannot undergo surgery or are at high risk of surgery.T-TEER reduces the degree of regurgitation by clamping leaflets,and is currently in the early stage of research and development exploration and clinical validation,mainly for functional TR.T-TEER devices have also made significant progress(TriClip,PASCAL),and Chinese-made novel-designed T-TEER devices are also undergoing clinical trials(DragonFly-TTM,SQ-Kyrin-TTM,NeoBlazarTM).This paper reviews the current applications and research progress of T-TEER.

Objective To establish a method for testing isolated mitral valve in vitro and quantitatively evaluate the effect of transcatheter edge-to-edge repair technology(TEER)on functional mitral regurgitation(FMR)(non-A2-P2 regurgitation).Methods In this study,an FMR(non-A2-P2 regurgitation)model was developed by dilating the annulus orifice and displacing the papillary muscle in isolated porcine mitral valve.The hydrodynamics characteristics of 6 valves were tested by a pulsatile flow testing system under different physiological and pathological conditions before and after TEER.Results The results show that the valve regurgitation improved from moderate-severe[regurgitant fraction(60.2±17.5)％]to mild-moderate[regurgitant fraction(34.7±12.0)％]by repair(P＜0.001).The EOA[(3.8±1.6)cm2 vs.(2.2±0.5)cm2,P＜0.001]and the forward cross valve pressure difference[(1.8±1.3)mmHg vs.(3.8± 1.8)mmHg,P＜0.001],which characterize the forward flow performance of the valve,were compared before and after repair,and the differences were statistically significant.At the same time,the repair caused valve stenosis(the effective orifice area decreased by 40％and the positive differential pressure increased by 110％),but the valves was still within the normal physiological range,and no iatrogenic stenosis was caused.Conclusions It can be seen that TEER has an effect on FMR.This study provides validation and evaluation methods in vitro for expanding indications and improving TEER,and reference for developing standards of transcatheter valve repair testing in vitro.

Objective:To investigate the clinical characteristics and prognosis of single center adult chronic myeloid leukemia in chronic phase(CML-CP).Methods:Clinical data of 41 adult CML-CP patients in Department of Hematology,Shanghai Fengxian District Central Hospital from January 2015 to May 2021 were retrospectively analyzed.The clinical characteristics and prognosis of patients between＜60 years group and ≥ 60 years group were compared.Results:The 41 patients included 27(65.9％)males and 14(34.1％)females.The median age of the patients was 56(19-84)years,with 22 cases(53.7％)＜60 years and 19 cases(46.3％)≥60 years.Univariate analysis indicated that the proportions of patients with comorbidities,intermediate/high-risk Sokal score,myelofibrosis,and lactate dehydrogenase ≥1 000 U/L were significantly increased in ≥60 years group compared with＜60 years group at initial diagnosis(all P＜0.05).There were no statistical differences in the distribution of sex,ELST score,white blood cell count,platelet count,peripheral blood basophil percentage,peripheral blood eosinophil percentage and bone marrow primitive cell percentage between the two groups(P＞0.05).The proportion of patients taking reduced-dose imatinib in≥60 years group significantly increased(P＜0.001).Patients＜60 years had a higher proportion of molecular biological remission after treatment of tyrosine kinase inhibitors(TKIs)than patients ≥ 60 years(P＜0.001).The incidence of non-hematologic adverse reactions to TKI therapy significantly increased in patients ≥ 60 years(P＜0.001).Multivariate analysis showed that no adverse factors affecting the efficacy and prognosis of TKI.Conclusion:Compared with adult CML-CP patients＜60 years,patients ≥ 60 years gain fewer benefits from TKI treatment and increased adverse reactions.

Three-dimensional graphene hydrogel(3DGH)was successfully prepared through a hydrothermal method,followed by its composition with gold nanoparticles(AuNPs)to construct a highly sensitive Au/3DGH graphene electrochemical transistor(GECT)dopamine(DA)sensor.AuNPs are efficient electrocatalytic materials.However,their tendency to aggregate during electrodeposition hinds the practical application.The porous and interconnected network structure of 3DGH provided abundant attachment sites,effectively preventing AuNPs aggregation.By modifying the sensor's gate with Au/3DGH,the excellent electrocatalytic performance of Au/3DGH towards DA and the high sensitivity of GECT were utilized to achieve highly sensitive detection of DA.The sensor exhibited a low detection limit of 20 nmol/L and a linear range of 20 nmol/L to 2.5 mmol/L.Remarkably,the sensor showed high sensitivity,excellent selectivity and strong stability,and hold great potnetial in highly sensitive portable detection of DA in disease prevention and clinical monitoring.

Objective To retrospectively analyze the ultra-fast track anesthesia(UFTA)methods and perioperative anesthesia management experiences of transcatheter mitral valve edge-to-edge repair(TEER)in the treatment of functional mitral regurgitant.Methods In this retrospective study,patients underwent the TEER procedure and received UFTA in Fuwai Yunnan Hospital,from May 2022 to September 2022 for heart failure combined with moderate to severe or severe functional mitral regurgitant were included.Baseline,preoperative complications,cardial function and anesthesia classification,amino-terminal probrain natriuretic peptide(NT-proBNP),ultrasound examination results,surgery time,extubation time,intraoperative anesthetic and vasoactive drug,complications related to TEER and UFTA,perioperative,and postoperative 30-day and one-year follow-up data were collected.All perioperative clinical data were recorded and analyzed.Results A total of 30 patients were enrolled,11 patients(36.7％)were female,mean age was(63.6±6.1)years,NYHA classification IV 14 patients(46.7％),left ventricular ejection fraction(LVEF)(36.0±8.1)％,the end-diastolic volume of the left ventricle(66.0±8.2)mm,mitral regurgitation 4+14 patients(56.7％),3+17 patients(43.3％),NT-proBNP(1 934.1±1 973.5)pg/ml,1 patient(3.3％)used high-dose vasoactive drugs during surgery.All patients did not experience nausea,vomiting,delirium,respiratory depression,perioperative transesophageal echocardiography-related gastrointestinal bleeding,pericardial effusion,cerebrovascular accidents,emergency surgery or secondary intervention,or other serious adverse events within 24 hours after surgery.No 30-day all-cause death occurred;the mean postoperative hospital stay was(7.4±2.8)days.All patients completed one-year follow-up,LVEF(37.6±11.1)％,the end-diastolic volume of the left ventricle(63.2±8.6)mm,mitral regurgitation 2+7 patients(23.3％),1+23 patients(76.7％),NT-proBNP(1 949.2±2 576.6)pg/ml.Conclusions Ultra-fast track anesthesia can be safely applied to TEER in treating functional mitral regurgitant patients.

Objective To design a hyperbaric oxygen chamber ambulance to meet the requirements for on-site hyperbaric oxygen treatment and transport of casualties.Methods A hyperbaric oxygen chamber ambulance was formed based on a YJ2080 wheeled armored vehicle,which had the components of a chamber,a gas source,an oxygen source,a control system and a power source.The chamber had a 3-layer composite structure,with a high-strength metal frame in the outer layer,a capsule made of polyurethane material bound with nylon pressure-resistant tape in the inner layer and a layer of thermal insulation material filled between the chamber and the vehicle;the gas source was composed of the oil-free air compressor,gas cylinder and pressure reducer;the oxygen source was made up of the 20 L oxygen generator,oxygen booster pump and 40 L oxygen cylinder;the control system involved in an EX2N-100HA series touch screen programmable logic controller(PLC)all-in-one(AIO);an ACD-15.0DR/48-H generator system was used as the power source.Results The hyperbaric oxygen chamber ambulance could stably control the chamber pressure when the therapeutic pressure was set as 1.3,1.6 and 1.8 ATA(1 ATA=0.1 MPa),the volume fraction of oxygen in the chamber could be limited within the required range under the low oxygen volume fraction mode and high oxygen volume fraction mode,and the emergency decompression time could be restrained within 60 s.Conclusion The hyperbaric oxygen chamber ambulance behaves well in maneuverability,and can be used for on-site hyperbaric oxygen treatment and transport of casualties.[Chinese Medical Equipment Journal,2024,45(10):25-30]

Endodontic diseases are a kind of chronic infectious oral disease.Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha.However,it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy(RCT).Recent research,encompassing bacterial etiology and advanced imaging techniques,contributes to our understanding of the root canal system's anatomy intricacies and the technique sensitivity of RCT.Success in RCT hinges on factors like patients,infection severity,root canal anatomy,and treatment techniques.Therefore,improving disease management is a key issue to combat endodontic diseases and cure periapical lesions.The clinical difficulty assessment system of RCT is established based on patient conditions,tooth conditions,root canal configuration,and root canal needing retreatment,and emphasizes pre-treatment risk assessment for optimal outcomes.The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT.These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.