BACKGROUND:Psoralen has a strong anti-osteoporotic activity and may have a restorative effect on chemotherapy-induced osteoporosis. OBJECTIVE:To explore the restorative effect of psoralen on the osteogenic differentiation of bone marrow mesenchymal stem cells in mice inhibited by cyclophosphamide and its mechanism. METHODS:C57BL/6 mouse bone marrow mesenchymal stem cells were isolated and cultured.Effect of psoralen on viability of bone marrow mesenchymal stem cells was detected by MTT assay.Osteogenic induction combined with alkaline phosphatase staining was used to determine the optimal dose of psoralen to restore the osteogenic differentiation of bone marrow mesenchymal stem cells inhibited by cyclophosphamide.The mRNA expression levels of Runx2,alkaline phosphatase,Osteocalcin,osteoprotegerin,and Wnt/β-catenin signaling pathway-related genes Wnt1,Wnt4,Wnt10b,β-catenin,and c-MYC were measured by RT-qPCR at different time points under the intervention with psoralen.The protein expression of osteogenic specific transcription factor Runx2 and Wnt/β-catenin signaling pathway related genes Active β-catenin,DKK1,c-MYC,and Cyclin D1 was determined by western blot assay at different time points under the intervention with psoralen. RESULTS AND CONCLUSION:(1)There was no significant effect of different concentrations of psoralen on the viability of bone marrow mesenchymal stem cells.The best recovery of the inhibition of osteogenic differentiation of bone marrow mesenchymal stem cells caused by cyclophosphamide was under the intervention of psoralen at a concentration of 200 μmol/L.(2)Psoralen reversed the reduction in osteogenic differentiation marker genes Runx2,alkaline phosphatase,Osteocalcin and osteoprotegerin mRNA expression and Runx2 protein expression in bone marrow mesenchymal stem cells caused by cyclophosphamide conditioned medium.(3)Psoralen reversed the decrease in Wnt/β-catenin pathway-related genes Wnt4,β-catenin,c-MYC mRNA and Active β-catenin,c-MYC,and Cyclin D1 protein expression and the increase in DKK1 protein expression in bone marrow mesenchymal stem cells caused by cyclophosphamide conditioned medium.(4)The results showed that cyclophosphamide inhibited osteogenic differentiation of bone marrow mesenchymal stem cells in mice,and psoralen had a restorative effect on it.The best intervention effect was achieved at a concentration of 200 μmol/L psoralen,and this protective effect might be related to the activation of Wnt4/β-catenin signaling pathway by psoralen.

Hypertrophic scar is a fibrous hyperplastic disorder that arises from skin injuries. The current therapeutic modalities are constrained by the dense and rigid scar tissue which impedes effective drug delivery. Additionally, insufficient autophagic activity in fibroblasts hinders their apoptosis, leading to excessive matrix deposition. Here, we developed an active microneedle (MN) system to overcome these challenges by integrating micromotor-driven drug delivery with autophagy regulation to remodel the scar microenvironment. Specifically, sodium bicarbonate and citric acid were introduced into the MNs as a built-in engine to generate CO₂ bubbles, thereby enabling enhanced lateral and vertical drug diffusion into dense scar tissue. The system concurrently encapsulated curcumin (Cur), an autophagy activator, and triamcinolone acetonide (TA), synergistically inducing fibroblast apoptosis by upregulating autophagic activity. In vitro studies demonstrated that active MNs achieved efficient drug penetration within isolated scar tissue. The rabbit hypertrophic scar model revealed that TA-Cur MNs significantly reduced the scar elevation index, suppressed collagen I and transforming growth factor-β1 (TGF-β1) expression, and elevated LC3 protein levels. These findings highlight the potential of the active MN system as an efficacious platform for autonomous augmented drug delivery and autophagy-targeted therapy in fibrotic disorder treatments.

This study is designed to address the development, synthesis, and screening of non-animal-derived nanoantibody libraries. Furthermore, it seeks to elucidate the impact of framework region selection and complementarity-determining region (CDR) design on the characteristics of synthesized nanoantibody libraries. These investigations aim to establish a robust theoretical and technical foundation for enhancing the efficacy, diversity, and practical applicability of synthetic nanoantibody libraries. In this study, a new framework (IGHV3S65*01-IGHJ4*01) was identified based on the high-throughput sequencing results of natural nanobodies, and degenerate primers were designed based on the frequency of amino acids at each position in the complementarity-determining region (CDR) region to synthesize the coding fragments of nanobodies by overlap PCR. After 40 times of electro-transformation, a single-frame synthesized nanobody library (SS-Library) containing 6×10⁹ clones was obtained, and the titer of the library was demonstrated to be 10¹³ PFU/mL after rescue by the helper phage M13K07. Random 48 single colonies were picked for PCR, which revealed an insertion rate of 95.8%. Sanger sequencing results showed that 38 clones had complete sequences, none of which showed cysteines or stop codons, and no identical sequences appeared, suggesting that the library had higher diversity. The library was screened and validated with three antigens, including bovine serum albumin (BSA), acetylcholinesterase (AchE), and immunoglobulin G (IgG). Finally, 2 nanobodies against BSA, 10 against AchE, and 15 against IgG were obtained. One positive clone of each antigen was singled out for recombinant expression, and the results showed that all the three nanobodies were expressed in a soluble form. The binding activity of recombinantly expressed nanobodies was evaluated using indirect enzyme-linked immunosorbent assay (ELISA) and bio-layer interferometry (BLI). The results demonstrated that the anti-AChE and anti-IgG nanobodies exhibited specific binding to their respective antigens, with affinity constants (KD) of 294 nmol/L and 250 nmol/L, respectively. The nanobody synthetic library preparation method proposed in this study is simple and easy to use with low preference, and it is expected to be a universal nanobody discovery platform for the preparation and development of lead specific nanobodies.
Single-Domain Antibodies/biosynthesis* ; Peptide Library ; Complementarity Determining Regions/immunology* ; Animals

Influenza imposes a significant disease burden on society and individuals annually, and influenza vaccination is considered a significant public health measure to prevent influenza and reduce influenza-related severe disease and death. The low influenza vaccination rate in China is partly due to certain factors affecting the willingness and behavior of individuals to receive them. Scientific research and targeted interventions on these factors can effectively improve the vaccination situation. Commonly used individual-level theoretical models for influenza vaccination behavior include the health belief model, protection motivation theory, and theory of planned behavior. This study reviews theoretical models commonly employed in researching influenza vaccination willingness and behavior. An overview of these practical applications and challenges models is presented to provide references for relevant research and intervention programs in China.

Objective:To establish a cell line stably expressing the transient receptor potential melastatin 2(TRPM2)channel for screening TRPM2 inhibitors based on PiggyBac transposition system.Methods:A plasmid PiggyBac-human TRPM2(pPB-hTRPM2)eukaryotic expression vector was constructed using PiggyBac transposition system.The plasmid and a helper plasmid were co-transfected into HEK293T cells to express TRPM2,which was identified by fluorescence and patch-clamp assays.The high throughput screening performance was assessed with the Z'factor.Calcium imaging and patch clamp techniques were employed to assess the initial activity of eleven compound molecules,confirming the inhibitory effects of the primary molecules on TRPM2.The protective effect of the screened compounds on damaged cells was validated using the oxygen-glucose deprivation/reperfusion(OGD/R)injury model and CCK-8 kit.The level of cellular reactive oxygen species(ROS)was detected by flow cytometry.The neuroprotective effects of the compounds were evaluated using a transient middle cerebral artery occlusion(tMCAO)mouse model.Results:The HEK293T cells transfected with pPB-hTRPM2-EGFP showed high TRPM2 expression.Puromycin-resistant cells,selected through screening,exhibited robust fluorescence.Whole-cell patch results revealed that induced cells displayed classical TRPM2 current characteristics comparable to the control group,showing no significant differences(P＞0.05).With a Z'factor of 0.5416 in calcium imaging,the model demonstrated suitability for high-throughput screening of TRPM2 inhibitors.Calcium imaging and electrophysiological experiments indicated that compound 6 significantly inhibited the TRPM2 channel.Further experiments showed that 1.0 μmol/L of compound 6 enhanced cell viability(P＜0.05)and reduced the level of ROS(P＜0.05)of SH-SY5Y under OGD/R injury.0.3 and 1.0 mg/kg of compound 6 reduced the cerebral infarction volume in tMCAO mice(both P＜0.05).Conclusions:A stable TRPM2 gene expressing cell line has been successfully established using PiggyBac gene editing in this study.TRPM2 channel inhibitors were screened through calcium imaging and patch clamp techniques,and an inhibitor compound 6 was identified.This compound can alleviate cell damage after OGD/R by reducing cellular ROS levels and has a protective effect against cerebral ischemia-reperfusion injury in mice.

Objective:To understand the epidemiological and etiological characteristics of hand-foot-mouth disease (HFMD) in the Nanshan District of Shenzhen City from 2019 to 2022 and to provide a scientific basis for HFMD prevention in the area.Methods:Epidemiological data on HFMD in Shenzhen Nanshan District from 2019 to 2022 in the China Information System for Disease Control and Prevention were analyzed using descriptive research methods.Real-time reverse transcription polymerase chain reaction (RT-PCR) was used to analyze the etiology characteristics of clinical specimens from HFMD patients. The VP1 gene of the dominant pathogen coxsackievirus A6 (CV-A6) was amplified and sequenced. SepMan Pro of DNASTAR software was used for sequence assembly and MegAlign was used for nucleotide homology analysis.Results:A total of 13 195 HFMD cases were reported in Shenzhen Nanshan District from 2019 to 2022, with an average annual incidence rate of 186.18/100, 000. Summer and autumn are the main onset seasons and children under 7 years old were the main population, accounting for 93.1%. The male-to-female ratio is 1.44∶1. A total of 451 clinical HFMD specimens were detected in the laboratory, including 403 positive (87.36%) and 48 negative (10.64%). The main pathogens were CV-A6 (63.03%), coxsackievirus A16 (CV-A16) (27.79%), coxsackievirus A4 (CV-A4) (4.71%), coxsackievirus A10 (CV-A10) (1.99%), Echovirus 11 (Echo-11) (0.25%), and uncertain type accounted for 2.23%, with no detection for enterovirus71 (EV71) type. The nucleotide homology of the 13 CV-A6 strains ranged from 94.0%?99.6%, and the nucleotide homology with the prototype strain Gdula ranged 84.1%?85.8%. The results of phylogenetic tree showed that all 13 CV-A6 strains in Nanshan District were of the D3a genotype.Conclusions:FHFMD in Nanshan District of Shenzhen City in 2019-2022 shows obvious differences in population and time distribution. Therefore, it is necessary to strengthen publicity and education on HFMD prevention and control in the summer and fall seasons and among key populations. CV-A6 and CV-A16 are the dominant strains of HFMD in Nanshan District, Shenzhen in recent years, so the monitoring of the dominant strains should be improved.

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.