Objective To evaluate the effectiveness of different tip positions applied to midline catheters(MC)and provide evidence-based evidence for venous catheter tip positioning in clinical practice.Methods Computerized searches of PubMed,Web of Science,Embase,Cochrane Library,CINAHL,CNKI,Wanfang Database,VIP,and CBM for studies on the effectiveness of applying MC with different tip positions were performed from the time of database construction to July 2024.Meta-analysis was performed using Rev Man 5.3 software after 2 investigators independently screened the studies,extracted the information and evaluated the quality of the included studies.Results A total of 9 studies with 2 302 hospitalized patients were included.The quality evaluation results of the included studies are all B-level.Meta-analysis showed that when the tip of the MC was located in the subclavian vein compared with the tip of the MC in the axillary vein,the rate of total catheter-related complications,phlebitis,blood leakage,infiltration,catheter occlusion,catheter dislocation,and catheter-associated thrombosis were lower,with a statistically significant difference(P＜0.05).When the tip of the MC was located in the subclavian vein compared with the tip of the MC in the axillary vein,the catheter retention time was longer,with a statistically significant difference(P=0.007).The descriptive analysis showed a lower rate of extubation due to complications when the tip of the MC was located in the subclavian vein compared with when the tip was located in the axillary vein(P＜0.05).Conclusion When the tip of the MC is located in the subclavian vein compared to when it is located in the axillary vein,the incidence of total catheter-related complications,phlebitis,blood leakage,infiltration,catheter occlusion,catheter dislocation,catheter-associated thrombosis,and the rate of catheter extractions due to complications were lower,and the catheter was left in place for a longer period of time.Due to the limitations of the quantity and quality of the included studies,more large-sample,high-quality studies are needed to further validate the effectiveness of different tip positions of MC.

Objective To explore the effect of different ways of out-of-plane shield on the tube current and cumulative radiation dose of CT scan.Methods The CT water membrane was scanned using Philips 128 row iCT scanner in different scanning methods:the 1-3 times,without the out-of-plane shield,the total length of localizer was 150 mm,270 mm,and 390 mm,respectively;the fourth time,the out-of-plane shield was used but was not present in the localizer;from the 5th to 7th pass,with out-of-plane shield and develop it in the localizer,with out-of-plane shield development lengths of 60 mm,180 mm,and 300 mm,respectively,and the out-of-plane shield was not within the formal scanning range.The tube current and cumulative radiation dose of various scanning methods were compared and a line graph of the tube current for scanning each layer was figured.Results(1)There was no statistically significant difference in tube current when there was no out-of-plane shield but the length of the localizer was different(P＞0.05).(2)When the pitch was 0.8,1.0,and 1.15 respectively,with out-of-plane shield but no shield object in the localizer,the scanning tube current was lower than that without shield scanning(P＜0.05).(3)When scanning with three different lengths of out-of-plane shield(60 mm,180 mm,300 mm)in the localizer,regardless of the pitch,the tube current was greater than that of unshield scanning(P＜0.05).(4)When there was a shield in the localizer,the closer to the shield,the higher the tube current in the formal scan.(5)The cumulative dose of scans with out-of-plane shield but without the presence of shield in the localizer was smaller than that of unshield scanning.However,with shield and the presence of shield scanning in the localizer,the cumulative radiation dose was greater than that of unshield scanning.Conclusion The presence of out-of-plane shield in the localizer may increase the tube current and radiation dose for formal scanning,and the closer to the shield,the more significant the increase in tube current.

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 explore the effect of different ways of out-of-plane shield on the tube current and cumulative radiation dose of CT scan.Methods The CT water membrane was scanned using Philips 128 row iCT scanner in different scanning methods:the 1-3 times,without the out-of-plane shield,the total length of localizer was 150 mm,270 mm,and 390 mm,respectively;the fourth time,the out-of-plane shield was used but was not present in the localizer;from the 5th to 7th pass,with out-of-plane shield and develop it in the localizer,with out-of-plane shield development lengths of 60 mm,180 mm,and 300 mm,respectively,and the out-of-plane shield was not within the formal scanning range.The tube current and cumulative radiation dose of various scanning methods were compared and a line graph of the tube current for scanning each layer was figured.Results(1)There was no statistically significant difference in tube current when there was no out-of-plane shield but the length of the localizer was different(P＞0.05).(2)When the pitch was 0.8,1.0,and 1.15 respectively,with out-of-plane shield but no shield object in the localizer,the scanning tube current was lower than that without shield scanning(P＜0.05).(3)When scanning with three different lengths of out-of-plane shield(60 mm,180 mm,300 mm)in the localizer,regardless of the pitch,the tube current was greater than that of unshield scanning(P＜0.05).(4)When there was a shield in the localizer,the closer to the shield,the higher the tube current in the formal scan.(5)The cumulative dose of scans with out-of-plane shield but without the presence of shield in the localizer was smaller than that of unshield scanning.However,with shield and the presence of shield scanning in the localizer,the cumulative radiation dose was greater than that of unshield scanning.Conclusion The presence of out-of-plane shield in the localizer may increase the tube current and radiation dose for formal scanning,and the closer to the shield,the more significant the increase in tube current.

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.

AIM:This study aimed to establish a model of functional impairment in INS-1 cells(rat insulino-ma cells)induced by prolonged exposure to a low level of interleukin-1β(IL-1β),and to investigate the underlying mech-anisms.METHODS:INS-1 cells were treated with different concentrations of IL-1β for 10 d.The cells were divided into control,0.05 μg/L IL-1β,0.1 μg/L IL-1β,and 0.2 μg/L IL-1β groups(n=3).Flow cytometry was employed to assess cell apoptosis,facilitating the identification of IL-1β concentrations that did not significantly induce apoptosis.Subse-quently,INS-1 cells were divided into control and IL-1β groups(n=3)and treated with 0.1 μg/L IL-1β for 10 days.The intracellular insulin content and glucose-stimulated insulin secretion level were detected by immunofluorescence and en-zyme-linked immunosorbent assay(ELISA).Differential proteins and associated signaling pathways were screened using 4D label-free proteomics technology.Moreover,fluorescent probes were used to detect glucose-stimulated calcium ion in-flux,and Western blot was conducted to verify the expression changes of relevant proteins in the nuclear factor kappa-B(NF-κB)signaling pathway and calcium signaling pathway.RESULTS:Treatment with 0.1 μg/L IL-1β for 10 days ex-hibited minimal impact on the survival of INS-1 cells but significantly reduced the intracellular insulin content and glucose-stimulated insulin secretion(P<0.01).Therefore,0.1 μg/L IL-1β was chosen for in vitro induction of functional impair-ment in INS-1 cells.Proteomic analysis showed no significant differences in the expression of apoptosis-related factors,such as caspase-3,B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax),and Bcl-2-associated death promoter(Bad),compared with the control(P>0.05).However,the expression of insulin,v-maf avian musculoaponeurotic fibro-sarcoma oncogene family protein A(Mafa),calcium/calmodulin-dependent protein kinase II(CaMKII),inositol 1,4,5-triphosphate receptor(IP3R),and NF-kappa-B inhibitor alpha(IκBα)was significantly reduced(P<0.01),while the protein expression levels of NF-κB and inducible nitric oxide synthase(iNOS)were significantly increased(P<0.05,P<0.01).Fluorescence probe results showed that,compared to the control,the calcium ion influx induced by glucose stimu-lation in the IL-1β group was significantly reduced(P<0.01).Western blot results demonstrated that the expression lev-els of IP3R,CaMKII,and IκBα in the IL-1β group were significantly reduced(P<0.05,P<0.01),while the expression levels of NF-κB and iNOS were significantly increased(P<0.01).CONCLUSION:A model of functional impairment in rat INS-1 cells induced by prolonged exposure to low levels of IL-1β has been successfully established,and it has been pre-liminarily confirmed that this impairment may be related to the activation of the NF-κB signaling pathway and dysfunction of the calcium signaling pathway.

Objective To understand the changing composition and antibiotic resistance of bacterial species in the clinical isolates from outpatient and emergency department(hereinafter referred to as outpatients)and inpatient children over time in various hospitals,and to provide laboratory evidence for rational antibiotic use.Methods The data on clinically isolated pathogenic bacteria and antimicrobial susceptibility of isolates from outpatients and inpatient children in the CHINET program from 2015 to 2021 were collected and analyzed.Results A total of 278 471 isolates were isolated from pediatric patients in the CHINET program from 2015 to 2021.About 17.1％of the strains were isolated from outpatients,primarily group A β-hemolytic Streptococcus,Escherichia coli,and Staphylococcus aureus.Most of the strains(82.9％)were isolated from inpatients,mainly SS.aureus,E.coli,and H.influenzae.The prevalence of methicillin-resistant S.aureus(MRSA)in outpatients(24.5％)was lower than that in inpatient children(31.5％).The MRSA isolates from outpatients showed lower resistance rates to the antibiotics tested than the strains isolated from inpatient children.The prevalence of vancomycin-resistant Enterococcus faecalis or E.faecium and penicillin-resistant S.pneumoniae was low in either outpatients or inpatient children.S.pneumoniae,β-hemolytic Streptococcus and S.viridans showed high resistance rates to erythromycin.The prevalence of erythromycin-resistant group A β-hemolytic Streptococcus was higher in outpatients than that in inpatient children.The prevalence of β-lactamase-producing H.influenzae showed an overall upward trend in children,but lower in outpatients(45.1％)than in inpatient children(59.4％).The prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKpn),carbapenem-resistant Pseudomonas aeruginosa(CRPae)and carbapenem-resistant Acinetobacter baumannii(CRAba)was 14％,11.7％,47.8％in outpatients,but 24.2％,20.6％,and 52.8％in inpatient children,respectively.The prevalence of multidrug-resistant E.coli,K.pneumoniae,Proteus mirabilis,P.aeruginosa and A.baumannii strains was lower in outpatients than in inpatient children.The prevalence of fluoroquinolone-resistant E.coli,ESBLs-producing K.pneumoniae,ESBLs-producing P.mirabilis,carbapenem-resistant E.coli(CREco),CRKpn,and CRPae was lower in children in outpatients than in inpatient children,but the prevalence of CRAba in 2021 was higher than in inpatient children.Conclusions The distribution of clinical isolates from children is different between outpatients and inpatients.The prevalence of MRSA,ESBL,and CRO was higher in inpatient children than in outpatients.Antibiotics should be used rationally in clinical practice based on etiological diagnosis and antimicrobial susceptibility test results.Ongoing antimicrobial resistance surveillance and prevention and control of hospital infections are crucial to curbing bacterial resistance.