BACKGROUND:Early exercise treatment is the main prevention way for traumatic joint contracture and is also a research focus.Swimming may be a potential intervention for joint contracture due to the special physical properties of water. OBJECTIVE:To explore the effects of swimming on the development of joint contracture in a rat model and study its mechanisms. METHODS:Twenty-four Sprague-Dawley rats were randomly divided into a blank control group(n=8)and a joint contracture group(n=16).After the surgical operation of knee joint contracture rat models,the joint contracture group was randomly subdivided into a surgical control group(n=8)and a swimming treatment group(n=8).Swimming started in the swimming treatment group in the second week after surgery and lasted for a total of 5 weeks.At the 6th week after surgery,the body mass,knee joint range of motion,and quadriceps diameter were tested,and the diameter/body mass index was calculated.Hematoxylin-eosin staining was performed to detect the pathological changes in the knee joint capsule and quadriceps muscle,and Masson staining was used to observe fibrotic changes in the knee joint capsule.Furthermore,the protein expression of transforming growth factor β1 and type I collagen in the knee joint capsule was quantified by immunohistochemical assay and western blot was performed to detect the protein expression of MuRF1 in the quadriceps femoris. RESULTS AND CONCLUSION:Compared with the blank control group,the knee range of motion decreased in the surgical control and swimming treatment groups(P<0.01),and knee extension deficit and arthrogenic extension deficit were significantly increased(P<0.01),the diameter of the quadriceps muscle was decreased(P<0.01),the joint capsule showed significant fibrosis,the quadriceps muscle was atrophied,and the diameter/body mass index was decreased(P<0.01).Compared with the surgical control group,the swimming treatment group showed a significant increase in knee joint range of motion and quadriceps diameter(P<0.01),and significant improvement in joint capsule fibrosis and quadriceps atrophy.Compared with the blank control group,collagen fiber content and expression of transforming growth factor β1 and type I collagen were increased in the joint capsule of rats in both the surgical control group and the swimming treatment group(P<0.01).Compared with the surgical control group,collagen fiber content and expression of transforming growth factor β1 and type I collagen protein in the joint capsule were decreased in the swimming treatment group.Compared with the blank control group,the expression of MuRF1 protein in the quadriceps muscle of rats in the surgical control group and the swimming treatment group was increased(P<0.05).Compared with the surgical control group,the expression of MuRF1 protein in the quadriceps muscle of rats in the swimming treatment group was decreased(P<0.05).To conclude,early swimming intervention reduces transforming growth factor β1 and type I collagen expression in the joint capsule of traumatic joint contracture rats,decreases MuRF1 expression in the quadriceps muscle,and increases joint range of motion and quadriceps diameter,thereby inhibiting the development of joint contracture.

AIM To investigate the effect of Fuzheng Hefu Zhiyang Formula(FZHFZY)on psoriasis-like skin lesions and immune regulation in mice.METHODS In the in vivo experiment,30 BALB/c mice were randomly divided into the blank group,the model group,the dexamethasone group(1.5 g/kg of compound dexamethasone acetate cream),and the low-dose(2.5 g/kg)and high-dose(5 g/kg)FZHFZY groups,with six mice in each group.The experiment groups were treated with respective FZHFZY and dexamethasone,and the other groups were given normal saline for 10 consecutive days,during which psoriatic skin lesions were induced with imiquimod cream for 7 consecutive days.The mice had their area and severity of psoriasis assessed by PASI score;their histological changes of skin lesions.observed with Hematoxylin-eosin(HE)staining;their F4/80 ratio of skin lesions observed with immunohistochemical(IHC)staining;their protein expressions of P38,p-P38,Erk,p-Erk,P65 and p-P65 detected by Western blot;and their mRNA expressions of tumor necrosis factor-α(TNF-α),IL-17,IL-23 and IL-1β detected by RT-qPCR.In the in vitro research,the cultured RAW264.7 cells were divided into the blank group,the LPS group,and the FZHFZY groups(1 200,600,300,150 μg/mL).The cells had their protein expressions of P38,p-P38,Erk,p-Erk,P65 and p-P65 detected with Western blot;and their mRNA expressions of IL-6,TNF-α,IL-23 and IL-8 detected by RT-qPCR.RESULTS The in vivo experiment showed that compared to the model group,the FZHFZY groups demonstrated decreased PASI score(P＜0.01);improved epidermal thickening and parakeratosis of skin lesions as revealed by HE staining result and increased expression of F4/80 in IHC staining sections;decreased protein expression ratios of p-P38/P38,p-ERK/Erk and p-P65/P65 in skin(P＜0.05,P＜0.01);and reduced mRNA expressions of TNF-α,IL-17,IL-23 and IL-1β in the skin(P＜0.01).FZHFZY(0～2 400 μg/mL)showed no significant cytotoxicity towards RAW264.7 cells in vitro(P＞0.05).Compared to those of the LPS group,the cells exposed to FZHFZ at concentrations of 1 200 and 600 μg/mL demonstrated decreased protein expression ratios of p-P38/P38,p-ERK/Erk,and p-P65/P65(P＜0.05,P＜0.01);and significantly decreased mRNA expressions of TNF-α,IL-17,IL-23 and IL-1β(P＜0.01).CONCLUSION FZHFZY alleviates imiquimod-induced psoriatic lesions in mice and suppresses inflammatory response in LPS-stimulated RAW264.7 cells by inhibiting P38/Erk/NF-κB signaling pathway.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Wound repair and infection have long posed significant challenges in clinical medicine.Am-phibians,adapting to complex environments through long-term natural selection,have evolved skin sys-tems with remarkable abilities to resist external damage and promote rapid wound healing,making them an important source for discovering candidate molecules for wound healing.In this study,a novel peptide composed of 22 amino acids,with the sequence"VGKAGLETAACKATNSCFNIDW"and a molecular weight of 2299.6 D,was screened from the cDNA library of Odorrana tormota and named PN-VW22.The peptide was synthesized by solid-phase synthesis,and its effects on cell proliferation were evaluated using the CCK-8 assay and scratch wound healing assay in human keratinocytes(HaCaT)and mouse em-bryonic fibroblasts(NIH3T3).Antibacterial activity was assessed by determining the minimum inhibitory concentration(MIC).Results showed that PN-VW22 at various concentrations had no significant effect on the cell viability in NIH3T3 cells(P＞0.05),but significantly enhanced HaCaT cell viability at 0.5μmol/L(P＜0.001).Meanwhile,PN-VW22 induced cell proliferation and promoted wound healing in HaCaT cells,with a healing rate of 64.44％after 24 h incubation at 0.5 μmol/L.Furthermore,PN-VW22 exhibited antibacterial activity against Staphylococcus aureus with an MIC value of 13.92 μmol/L.In sum,this study identified PN-VW22 as a novel bifunctional peptide with both wound repair and anti-infective properties,providing a new toxin peptide template for the development of wound healing drugs.

Objective To evaluate the association of different obesity phenotypes and their components with the risk of cognitive impairment in older Chinese adults,and to assess the association between obesity and cognitive impairment in different cognition-related genetic backgrounds.Methods A cross-sectional study based on the West China Health and Aging Cohort was conducted.Logistic regression was applied to estimate the association of obesity phenotypes and components with cognitive impairment in older Chinese adults stratified by APOE gene and polygenic risk scores.Results A total of 7 316 participants were enrolled,of whom 1 820 had cognitive impairment.Weight gains were associated with a reduced risk of cognitive impairment(odds ratio[OR]=0.96,95%CI,0.95-0.97).Being overweight with a normal waist-to-hip ratio was a protective factor for cognition(OR=0.74,95%CI,0.61-0.90),whereas the coexistence of elevated waist-to-hip ratio and overweight did not increase the risk of cognitive impairment.Sarcopenia was associated with an elevated risk of cognitive impairment.This association was found in both overweight(OR=2.03,95%CI,1.71-2.41)and non-overweight older adults(OR=1.86,95%CI,1.58-2.20),and was significant across all polygenic risk score strata.Conclusion Increasing body mass may serve as a key protective factor against cognitive decline in older adults.Having sarcopenia and obesity is associated with an elevated risk of cognitive impairment,independent of genetic susceptibility.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Wound repair and infection have long posed significant challenges in clinical medicine.Am-phibians,adapting to complex environments through long-term natural selection,have evolved skin sys-tems with remarkable abilities to resist external damage and promote rapid wound healing,making them an important source for discovering candidate molecules for wound healing.In this study,a novel peptide composed of 22 amino acids,with the sequence"VGKAGLETAACKATNSCFNIDW"and a molecular weight of 2299.6 D,was screened from the cDNA library of Odorrana tormota and named PN-VW22.The peptide was synthesized by solid-phase synthesis,and its effects on cell proliferation were evaluated using the CCK-8 assay and scratch wound healing assay in human keratinocytes(HaCaT)and mouse em-bryonic fibroblasts(NIH3T3).Antibacterial activity was assessed by determining the minimum inhibitory concentration(MIC).Results showed that PN-VW22 at various concentrations had no significant effect on the cell viability in NIH3T3 cells(P＞0.05),but significantly enhanced HaCaT cell viability at 0.5μmol/L(P＜0.001).Meanwhile,PN-VW22 induced cell proliferation and promoted wound healing in HaCaT cells,with a healing rate of 64.44％after 24 h incubation at 0.5 μmol/L.Furthermore,PN-VW22 exhibited antibacterial activity against Staphylococcus aureus with an MIC value of 13.92 μmol/L.In sum,this study identified PN-VW22 as a novel bifunctional peptide with both wound repair and anti-infective properties,providing a new toxin peptide template for the development of wound healing drugs.

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.