Objective To explore the effects of TRAF6 inhibition on autophagy,myocardial inflammation and cardiac function in septic mice.Methods Twenty-four male Kunming mice were randomly divided into 4 groups:sham,sham + C25-140(sham+C),cecal ligation and puncture(CLP),and cecal ligation and puncture+C25-140(CLP+C)group.Sham+C group and CLP+C group were intraperitoneally injected with C25-140 after operation.LVEF and LVFS were evaluated by ultrasound 24 hours after operation.Serum TNF-α and IL1-β were measured by ELISA.HE staining was used to evaluate myocardial inflammatory response.Autophagosomes and mitochondrial microstructure of cardiomyocytes were observed by transmission electron microscopy.TRAF6 mRNA in myocardial tissue was detected by qPCR.The expression of TRAF6,P62,Beclin-1 and LC3B protein was detected by W-B.The effect of C25-140 on myocardial injury in the septic mice was observed by inhibiting autophagy with 3-MA.Results Compared with the sham group,the levels of TRAF6 mRNA and TRAF6 in the myocardial tissue in the CLP group were significantly increased(P<0.05)and the serum TNF-α and IL1-β concentrations were signifi-cantly increased(P<0.05).Meanwhile,the myocardial tissue HE staining showed inflammatory cell infiltration and the LVEF and LVFS levels were significantly decreased in the CLP group(P<0.05).Compared with CLP group,the CLP+C group showed that the expression of TRAF6 mRNA and TRAF6 protein decreased(P<0.05),serum TNF-α and IL1-β decreased(P<0.05),myocardial histopathological myocardial inflammatory cell infiltration decreased,the LVEF and LVFS levels increased(P<0.05).Electron microscopy showed that the mitochondrial swelling decreased,autophagosomes increased,expression of Beclin-1 and LC3Ⅱ/Ⅰ increased,and P62 expression decreased(P<0.05).As compared with CLP+C group,the CLP+C+3-MA group showed that obvious inflamma-tory cell infiltration in the myocardial pathology and the LVEF and LVFS levels decreased after 3-MA inhibited autophagy(P<0.05).Conclusion Inhibition of TRAF6 can not only ameliorate myocardial inflammatory injury and cardiac dysfunction in septic mice,but promote the involvment of cardiomyocyte autophagy in provention from sepsis-induced myocardial injury.

BACKGROUND:Sepsis complicated by myocardial injury is characterized by a high mortality.Metformin can prevent sepsis-induced myocardial dysfunction by exerting anti-inflammatory effects,improving oxidative stress,and reducing apoptosis.However,it is unclear whether metformin-induced autophagy plays an important role in the protective effect against sepsis-induced myocardial injury. OBJECTIVE:To explore the effect of metformin pretreatment on myocardial injury in septic mice. METHODS:A total of 40 male Kunming mice were randomly divided into sham operation group,model group,metformin group,and metformin+ 3-methyladenine group,with 10 mice in each group.The latter two groups were intraperitoneally injected with metformin for 14 days at a fixed time every day,and the metformin+3-methyladenine group was intraperitoneally injected with 3-methyladenine 1 hour before modeling.Twenty-four hours after the last injection of metformin,cecal ligation and perforation were used to construct a model of myocardial injury in septic mice.The sham operation group was not ligated and perforated.All mice were sacrificed 24 hours after surgery,and blood and myocardial specimens were collected.The levels of inflammatory factors and myocardial injury markers in serum were detected by ELISA.The mRNA expression of autophagy markers LC3B and p62 in myocardial tissue was detected by RT-qPCR.The protein expression of LC3B,Beclin-1,p62,p-AMPK,and AMPK in myocardial tissue was detected by western blot.The pathological changes in myocardial tissue were detected by hematoxylin-eosin staining. RESULTS AND CONCLUSION:Autophagy was inhibited in septic mice with myocardial injury.Compared with the sham operation group,the levels of serum tumor necrosis factor-α,interleukin-1β,interleukin-6,creatine kinase isoenzyme,and troponin T were increased in the model group(P<0.05),but there was no significant difference in p62,LC3Ⅱ/LC3Ⅰ,and p-AMPK/AMPK between the two groups(P>0.05).Compared with the model group,the levels of tumor necrosis factor-α,interleukin-6,creatine kinase isoenzyme,troponin T,and p62 were decreased in the metformin group(P<0.05),while LC3Ⅱ/LC3Ⅰ,p-AMPK/AMPK and Beclin-1 level were increased(P<0.05).Compared with the metformin group,the levels of tumor necrosis factor-α,interleukin-6,creatine kinase isoenzyme,troponin T,and p62 were increased in the metformin+3-methyladenine group(P<0.05),while LC3Ⅱ/LC3Ⅰ and Beclin-1 level were decreased(P<0.05).Myocardial hematoxylin-eosin staining indicated that myocardial fibers arranged normally in the sham operation group,but disorderedly in the model group,with interstitial edema and a large number of infiltrated inflammatory cells.A small amount of vacuolar changes were observed in the metformin group.The arrangement of myocardial fibers in the metformin+3-methyladenine group was slightly disordered,with more vacuolar changes.To conclude,metformin pretreatment may reduce myocardial injury in septic mice by activating the AMPK signaling pathway and inducing autophagy.

Objective:To study the current status of longitudinal extrauterine growth restriction (EUGR) in extremely preterm infants (EPIs) and to develop a prediction model based on clinical data from multiple NICUs.Methods:From January 2017 to December 2018, EPIs admitted to 32 NICUs in North China were retrospectively studied. Their general conditions, nutritional support, complications during hospitalization and weight changes were reviewed. Weight loss between birth and discharge > 1SD was defined as longitudinal EUGR. The EPIs were assigned into longitudinal EUGR group and non-EUGR group and their nutritional support and weight changes were compared. The EPIs were randomly assigned into the training dataset and the validation dataset with a ratio of 7∶3. Univariate Cox regression analysis and multiple regression analysis were used in the training dataset to select the independent predictive factors. The best-fitting Nomogram model predicting longitudinal EUGR was established based on Akaike Information Criterion. The model was evaluated for discrimination efficacy, calibration and clinical decision curve analysis.Results:A total of 436 EPIs were included in this study, with a mean gestational age of (26.9±0.9) weeks and a birth weight of (989±171) g. The incidence of longitudinal EUGR was 82.3%(359/436). Seven variables (birth weight Z-score, weight loss, weight growth velocity, the proportion of breast milk ≥75% within 3 d before discharge, invasive mechanical ventilation ≥7 d, maternal antenatal corticosteroids use and bronchopulmonary dysplasia) were selected to establish the prediction model. The area under the receiver operating characteristic curve of the training dataset and the validation dataset were 0.870 (95% CI 0.820-0.920) and 0.879 (95% CI 0.815-0.942), suggesting good discrimination efficacy. The calibration curve indicated a good fit of the model ( P>0.05). The decision curve analysis showed positive net benefits at all thresholds. Conclusions:Currently, EPIs have a high incidence of longitudinal EUGR. The prediction model is helpful for early identification and intervention for EPIs with higher risks of longitudinal EUGR. It is necessary to expand the sample size and conduct prospective studies to optimize and validate the prediction model in the future.

Objective : To investigate the possible mechanism of metformin (Met) -induced cardiomyocyte autoph- agy in protecting myocardial injury in septic mice． Methods : The model of myocardial injury in septic mice was es- tablished by cecal ligation and puncture ( CLP) ．Sixty Kunming mice were randomly divided into sham operation group (Sham group) ，model group ( CLP group) ，model + dimethyl sulfoxide ( DMSO) group ( CLP + DMSO group) ，model + metformin (Met) group (Met group) ，model + Met + 3-methyladenine (3-MA) group (Met + 3- MA group) ，model + Met + compound C ( CC) group (Met + CC group) ，with 10 mice in each group．The Met， Met + 3-MA and Met + CC groups were intraperitoneally injected with Met (200 mg / kg) once a day for 2 weeks be- fore modeling．The Met + 3-MA group was intraperitoneally injected with 3-MA ( 10 mg / kg) 1 h before surgery. The Met + CC group was intraperitoneally injected with CC (20 mg / kg) 30 min before surgery．The model was es- tablished 24 h after the last injection of Met．The heart and blood of all mice were collected 24 h after surgery．The Western blot technique was employed to assess the relative expression levels of microtubule-associated protein 1 light chain 3 (LC3) isoforms，namely LC3 I and LC3 II，autophagy effector protein 1 (Beclin-1) ，ubiquitin-bind- ing protein 62 (p62) ，B-cell lymphoma / leukemia-2 (Bcl-2) ，Bcl-2-associated X protein (Bax) ，adenosine mono- phosphate (AMP) kinase (AMPK) and phosphorylated AMPK (p-AMPK) ．Myocardial pathological changes were observed by hematoxylin-eosin (HE) staining．The changes of myocardial mitochondria and autophagosomes were observed by electron microscopy．Hematoxylin-eosin (HE) staining was used to observe the pathological changes of myocardium． Electron microscopy was used to observe the changes of myocardial mitochondria and autophago- somes. Results : Compared with Sham group，the relative protein expression of Beclin-1，p62，p-AMPK / AMPK and LC3 II / LC3 I in CLP and CLP + DMSO groups had no statistical significance，but Bax increased and Bcl-2 de- creased in CLP group (P＜0. 01) ．Compared with CLP group，the relative expression of Beclin-1 protein and LC3 II / LC3 I in Met group increased and p62 decreased (P＜0. 01) ，Bax decreased and Bcl-2 increased (P＜0. 01) . Compared with Met group，the relative protein expression of Beclin-1 and LC3 II / LC3 I in Met + 3-MA group de- creased and p62 increased (P＜0. 05) ，Bax increased and Bcl-2 decreased (P＜0. 05) ．Besides，the relative pro- tein expression of p-AMPK / AMPK in Met + CC group decreased (P＜0. 05) ．HE staining showed that there was no disorder in myocardial fibers in Sham group，and a large number of inflammatory cells infiltrated the myocardial fibers of CLP group in a clear disorder．The Met group showed vacuolar changes in the myocardium，while the Met + 3-MA group showed disordered arrangement of myocardial fibers and a small amount of inflammatory cell infiltra- tion．Under electron microscopy，the morphology of myocardial mitochondria in the Sham group was normal，while in the CLP group，the arrangement of mitochondrial cristae was disordered with vacuolar changes，and occasional autophagosomes were observed．Mitochondria in Met group showed slight swelling and a large number of autophago- somes．The mitochondria in the Met + 3-MA group showed significant swelling with a small amount of autophago- somes． Conclusion The protective effect of metformin on myocardial injury in septic mice can reduce cardiomyo- cyte apoptosis and improve mitochondrial damage by activating AMPK signaling pathway to induce autophagy.

Fluorescence microscopy is a vital tool in life science research, but the diffraction nature of light limits further observation of cells. Super-resolution imaging techniques provide deeper insights into cellular structures, including stimulated emission depletion microscopy (STED), structured illumination microscopy (SIM), and single-molecule localization microscopy (SMLM). Each of these methods offers unique advantages and principles that push the boundaries of spatial resolution beyond conventional diffraction limits. Among these techniques, SMLM stands out for its exceptional resolution, offering nanometer resolution and becoming a powerful tool for obtaining high-resolution images. SMLM is particularly valuable for studying the spatial distribution and interactions of organelles and macromolecular complexes. Following the award of the Nobel Prize in Chemistry in 2014, super-duper resolution imaging techniques were listed as one of Nature’s seven technologies to watch in 2024. The development of these techniques remains an important area of research. We introduce the development of multi-color SMLM, three-dimensional (3D) SMLM, and nanoscale resolution microscopes. We describe several methods to achieve multi-color SMLM. Sequential imaging and Exchange-PAINT require image targets in sequence, excitation or emission spectral demixing can obtain multi-color images simultaneously based on spectral difference between fluorescent dyes, dual-channel spectroscopic SMLM to achieve simultaneous imaging and spectral analysis of each molecule, and techniques based on binding kinetics of PAINT achieve multi-color by designing the blinking behavior of targets with engineered binding frequency and duration in DNA-PAINT. We then discuss various approaches for 3D imaging. Point spread function (PSF) engineering techniques manipulate the shape and properties of the PSF to improve 3D localization accuracy. Multi-plane imaging methods capture images from different focal planes and reconstruct them to obtain 3D information. Interferometry methods use single molecule interference to achieve high precision in axial localization, providing another way for high resolution 3D nanoscopy. Finally, we highlight advances in new nanoscale resolution microscopes based on modulated illumination patterns, including minimal photon fluxes (MINFLUX), repetitive optical selective exposure (ROSE), ROSE-Z, SIMFLUX, SIMPLE, and ModLoc. MINFLUX is known for its ability to achieve ultra-high resolution by detecting minimal photon fluxes from single molecules using a doughnut-shaped excitation spot to spatially modulate excitation intensities. Typically, we focus on ROSE and ROSE-Z, which outperform other techniques, using a resonant mirror to eliminate localization errors caused by fluorescence blinking. Recently, resolution enhancement by sequential imaging (RESI) and one nanometre expansion (ONE) was introduced to achieve resolution down to the Ångström scale. Nanoscopy serves as a new role between super resolution microscopy and structural biology and will lead to more discoveries in complex biological systems. Overall, this article provides a comprehensive overview of current advances in super-resolution imaging techniques, highlighting their contributions to overcoming the diffraction limit and enabling detailed observation of nanoscale biological structures, and provides an outlook on promising new techniques and applications. Through detailed descriptions of the principles, benefits, and applications of multi-color and 3D techniques, the article highlights new nanoscale imaging techniques that are expanding our ability to visualize and understand the intricate details of molecular and cellular processes. We hope that this article can be a primer resource for both newcomers and seasoned practitioners of SMLM.

As a novel tumor treatment,photodynamic therapy(PDT)has been widely used in clinical treatment of a variety of tumors due to its advantages,such as fewer adverse reactions,precise targeting and repeatability of treatment.Unlike conventional treatments,such as surgery,chemotherapy and radiotherapy,PDT not only eliminates the primary tumor but also effectively inhibits metastatic tumors by activating the body's immune response.However,the PDT-activated immune response is influenced by multiple factors,including the localization and dose of photosensitizer in the cells,light parameters,oxygen concentration in the tumor,and the integrity of immune function.This review summarizes the mechanisms behind the PDT-activated anti-tumor immune response,systematically examines the key influencing factors on the immune effect of PDT,and discusses the future development direction of PDT in cancer treatment.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.