ObjectiveTo explore the sequential effects of hypoxic exercising on miR-27/PPARγ and lipid metabolism target gene and protein expression levels in the obesity rats’ liver. Methods13-week-old male diet-induced obesity rats were randomly divided into three groups (n＝10): normal oxygen concentration quiet group (N), hypoxia quiet group (H), hypoxic exercise group (HE). Exercise training on the horizontal animal treadmill for 1 h/d, 5 d/week for a total of 4 week, and the intensity of horizontal treadmill training was 20 m/min (hypoxic concentration was 13.6%). Comparison of the weights of perirenal fat and epididymal fat in rats across different groups and calculation of Lee’s index based on body weight and body length of rats in each group were done. And the serum concentrations of total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) levels were detected. RT-PCR and Western Blot were used to detect the levels of miR-27, PPARγ, CYP7A1 and CD36. ResultsHypoxic exercise decreased the expression levels of miR-27 in the obese rats’ liver, however, the expression level of PPARγ was gradually increased. The expression levels of miR-27 in HE group were significantly lower than N group (P<0.05). The expression levels of PPARγ mRNA in N group were significantly lower than H group (P<0.05), especially lower than HE group (P<0.01). The protein expression of PPARγ protein in N group was significantly lower than that other groups (P<0.01). The expression of lipid metabolism-related genes and proteins increased in the obese rats’ liver. The expression of CYP7A1 mRNA in N group was significantly lower than H group (P<0.05), especially lower than HE group (P<0.01). The expression of CYP7A1 protein in the obese rats’ liver in N group was extremely lower than H group and HE group (P<0.01). The protein expression of CD36 in N group was significantly lower than that in HE group (P<0.05). Hypoxia exercise improved the related physiological and biochemical indexes of lipid metabolism disorder. The perirenal fat weight of obese rats in HE group was extremely lower than N group and H group (P<0.01), and the perirenal fat weight in N group was significantly higher than H group (P<0.05). The epididymal fat weight in N group was significantly higher than H group (P<0.05), and extremely higher than HE group (P<0.01). The Lee’s index in HE group was extremely lower than N group and H group (P<0.01). The serum concentration of TC in obese rats in HE group was extremely lower than N group and H group (P<0.01). The serum concentration of TG in HE group was extremely lower than N group and H group (P<0.01). The serum concentration of LDL-C in N group was extremely higher than HE group (P<0.01). The serum concentration of HDL-C in N group was extremely lower than H group (P<0.01). ConclusionHypoxia and hypoxia exercise may negatively regulate the levels of PPARγ by inhibiting miR-27 in the obese rats’ liver, thereby affecting the expression of downstream target genes CYP7A1 and CD36, and promoting cholesterol, fatty acid oxidation and HDL-C transport in the liver, and ultimately the lipid levels in obese rats were improved. The effect of hypoxia exercise on improving blood lipid is better than simple hypoxia intervention.

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 study the effect of auditory and speech development after cochlear implant(CI)in children with bilateral cochlear nerve deficiency(CND)and its influencing factors.Methods A total of 20 children with bilateral CND were included in the study,of which 5 were implanted bilaterally and 15 unilaterally.CT of the temporal bone showed stenosis of the cochlear aperture in 14 cases and atresia of the cochlear aperture in 6 cases.There were 8 cases accompanied by other inner ear malformations,and 12 cases with no accompanying inner ear mal-formations.MRI of the internal auditory canal showed 1 nerve in 5 cases,2 nerves in 6 cases,3 nerves in 8 cases,and 4 nerves in 1 case.There were 6 cases in which the EABR was not elicited and 14 cases in which it was elicited.The postoperative auditory and speech abilities of the subjects were evaluated using categories of auditory perform-ance(CAP)and speech intelligibility rating(SIR).Results ① The CAP(P＜0.001)and SIR(P＜0.001)scores of the children with stenosis of the cochlea nerve canal were higher than those of the patients with atresia of the cochlea nerve canal.② The more nerve roots in the internal auditory canal,the higher the score of CAP(P=0.003)and SIR(P=0.008).③ CAP score of the children with EABR elicited was higher than that of the children without EABR elicited(P=0.030).The difference in SIR scores was not statistically significant(P=0.14).④The differences in CAP and SIR between those with bilateral CI and unilateral CI,as well as between those with and without other inner ear malformations,were not statistically significant(P＞0.05).Conclusion Children with bi-lateral CND had significant postoperative improvement in auditory function but poor speech development after CI.Postoperative auditory speech ability was related to the condition of the cochlear foramen,the number of nerve roots in the internal auditory canal,and whether or not the EABR was elicited intraoperatively.

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.

Aim To investigate the role and regulatory mechanism of CREB regulated transcription coactivator 2(CRTC2)in cardiomyocyte hypertrophy.Methods A pathological cardiomyocyte hypertrophy model was established in C57BL/6 mice by intraperitoneal injection of isoproterenol(ISO),the expression of CRTC2 in cardiac tissue was detec-ted by Western blot.The CRTC2 knockout mice model was constructed,the cardiac function of mice was detected by small animal echocardiography,the collagen fiber content in mice cardiac tissue was detected by Masson staining,the car-diomyocyte hypertrophy related proteins:skeletal muscle α1-actin(ACTA1)and brain natriuretic peptide(BNP),as well as ferroptosis related proteins:acyl-CoA synthetase long chain family member 4(ACSL4),solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4)in mice cardiac tissue were detected by Western blot,the iron ion content in mice cardiac tissue was detected by iron ion kit,to evaluate the correlation between CRTC2 and cardiomyocyte hypertrophy and ferroptosis.H9c2 cells were induced by ISO to construct an in vitro model of cardiomyocyte hypertrophy,the protein expressions of CRTC2,ACTA1,BNP,ACSL4,SLC7A11 and GPX4 were detected after intervention with fer-roptosis inhibitor ferrostatin-1(Fer-1).H9c2 cells with CRTC2 overexpression induced by ISO were used to construct an in vitro model of cardiomyocyte hypertrophy,the related indicators of cardiomyocyte hypertrophy and ferroptosis were detec-ted to explore the mechanism of CRTC2 in cardiomyocyte hypertrophy.Results Compared with the control group,the expression of CRTC2 protein in the cardiac tissue of ISO induced cardiomyocyte hypertrophy mice was increased(P＜0.05).Compared with wild-type mice,CRTC2-/-mice showed worsened cardiac function,manifested as increased left ventricular end-diastolic diameter(LVEDD),left ventricular end-systolic diameter(LVESD),left ventricular posterior wall thickness(LVPWT),heart weight/tibia length(HW/TL)and heart weight/body weight(HW/BW),decreased short axis shortening(FS)and ejection fraction(EF),increased collagen fiber content in cardiac tissue,upregulated ex-pression of cardiomyocyte hypertrophy-related proteins ACTA1 and BNP,increased mRNA and protein expression of ferrop-tosis-related protein ACSL4,decreased mRNA and protein expression of SLC7A11 and GPX4,and elevated iron ion content in cardiac tissue(P＜0.05 or P＜0.01).In vitro experiments showed that compared with ISO group,the ISO+Fer-1 group had no significant change in CRTC2 protein expression(P＞0.05),the expression of ACTA1 and BNP protein decreased,the surface area of cardiomyocyte reduced,the expression of ACSL4 protein decreased,and the expression of SLC7A11 and GPX4 proteins increased(P＜0.05 or P＜0.01).Compared with the ISO group,the LV-CRTC2+ISO group showed a decrease in surface area of cardiomyocytes(P＜0.01),a decrease in ACTA1,BNP and ACSL4 protein ex-pression,an increase in SLC7A11 and GPX4 protein expression,and a decrease in ROS and iron ion content(P＜0.05 or P＜0.01).Conclusion CRTC2 alleviates cardiomyocyte hypertrophy and protect cardiac function by suppressing fer-roptosis in cardiomyocytes.

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.

Aim To investigate the role and regulatory mechanism of CREB regulated transcription coactivator 2(CRTC2)in cardiomyocyte hypertrophy.Methods A pathological cardiomyocyte hypertrophy model was established in C57BL/6 mice by intraperitoneal injection of isoproterenol(ISO),the expression of CRTC2 in cardiac tissue was detec-ted by Western blot.The CRTC2 knockout mice model was constructed,the cardiac function of mice was detected by small animal echocardiography,the collagen fiber content in mice cardiac tissue was detected by Masson staining,the car-diomyocyte hypertrophy related proteins:skeletal muscle α1-actin(ACTA1)and brain natriuretic peptide(BNP),as well as ferroptosis related proteins:acyl-CoA synthetase long chain family member 4(ACSL4),solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4)in mice cardiac tissue were detected by Western blot,the iron ion content in mice cardiac tissue was detected by iron ion kit,to evaluate the correlation between CRTC2 and cardiomyocyte hypertrophy and ferroptosis.H9c2 cells were induced by ISO to construct an in vitro model of cardiomyocyte hypertrophy,the protein expressions of CRTC2,ACTA1,BNP,ACSL4,SLC7A11 and GPX4 were detected after intervention with fer-roptosis inhibitor ferrostatin-1(Fer-1).H9c2 cells with CRTC2 overexpression induced by ISO were used to construct an in vitro model of cardiomyocyte hypertrophy,the related indicators of cardiomyocyte hypertrophy and ferroptosis were detec-ted to explore the mechanism of CRTC2 in cardiomyocyte hypertrophy.Results Compared with the control group,the expression of CRTC2 protein in the cardiac tissue of ISO induced cardiomyocyte hypertrophy mice was increased(P＜0.05).Compared with wild-type mice,CRTC2-/-mice showed worsened cardiac function,manifested as increased left ventricular end-diastolic diameter(LVEDD),left ventricular end-systolic diameter(LVESD),left ventricular posterior wall thickness(LVPWT),heart weight/tibia length(HW/TL)and heart weight/body weight(HW/BW),decreased short axis shortening(FS)and ejection fraction(EF),increased collagen fiber content in cardiac tissue,upregulated ex-pression of cardiomyocyte hypertrophy-related proteins ACTA1 and BNP,increased mRNA and protein expression of ferrop-tosis-related protein ACSL4,decreased mRNA and protein expression of SLC7A11 and GPX4,and elevated iron ion content in cardiac tissue(P＜0.05 or P＜0.01).In vitro experiments showed that compared with ISO group,the ISO+Fer-1 group had no significant change in CRTC2 protein expression(P＞0.05),the expression of ACTA1 and BNP protein decreased,the surface area of cardiomyocyte reduced,the expression of ACSL4 protein decreased,and the expression of SLC7A11 and GPX4 proteins increased(P＜0.05 or P＜0.01).Compared with the ISO group,the LV-CRTC2+ISO group showed a decrease in surface area of cardiomyocytes(P＜0.01),a decrease in ACTA1,BNP and ACSL4 protein ex-pression,an increase in SLC7A11 and GPX4 protein expression,and a decrease in ROS and iron ion content(P＜0.05 or P＜0.01).Conclusion CRTC2 alleviates cardiomyocyte hypertrophy and protect cardiac function by suppressing fer-roptosis in cardiomyocytes.

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.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.