Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

Exosome is a kind of extracellular vesicles secreted by cells to the outside. Biogenesis mainly involves two invaginations of the cytoplasmic membrane, the formation of multivesicular bodies, and the release of exosomes. Exosomes have abundant and diverse inclusions—including landmark membrane proteins, soluble proteins, various RNA molecules and DNA fragments, etc. Cells can achieve intercellular signal communication by secreting and receiving exosomes. Through interaction of ligand molecules on the exosome membrane with receptors on the surface of other cytoplasmic membranes, exosomes can activate cell signal transduction or fuse with the cell membrane to release its contents into the cytoplasm to exert regulatory functions. In the central nervous system, exosomes secreted by neurons and various glial cells can mediate wired synaptic signal transmission, but mainly play a role similar to neuromodulator by way of volume transmission. In this paper, the biogenesis of exosomes and important functional components are described in detail, and the characteristics of neural exosomes in the biogenesis, content sorting and controlled release are compared with those of synaptic vesicles. We further review the research progress on the physiological functions of neural exosomes on the central nervous system and their roles in the occurrence and development of neurodegenerative diseases and major depressive disorder. We also prospect the application of exosomes in the early diagnosis and targeted therapy of nervous system diseases.

Vascular calcification is a highly regulated process of ectopic calcification in cardiovascular system while no effective intervention can be clinically performed up to date.As vascular calcification undergoes a common regulatory mechanism within bone formation,bone morphogenetic protein 7(BMP-7)main-tains contractile phenotype of vascular smooth muscle cells and further inhibits vascular calcification via promoting the process of osteoblast differentiation,reducing ectopic calcification pressure by increasing bone formation and reducing bone resorption.This work systematically reviews the role of BMP-7 in vascular calcifi-cation and the possible mechanism,and their current clinical application as well.The current proceedings may help develope early diagnostic strategy and therapeutic treatment with BMP-7 as a new molecular marker and potential drug target.The expec-tation could achieve early prevention and intervention of vascular calcification and improve poor prognosis on patients.

Objective To investigate the dosimetric effects of different calculation grid size(CGS)in helical tomotherapy(HT)planning system on stereotactic body radiation therapy(SBRT)for non-small cell lung cancer(NSCLC).Methods Nine NSCLC patients receiving radiation therapy for the first time at some hospital from March 2019 to December 2022 were selected as the subjects.SBRT planning was carried out through the HT system with three different CGS plans(Fine,Normal,and Coarse)and the same pitch,modulation factor(MF)and optimization conditions,and the target area indexes of the three CGS plans were compared including conformity index(CI),homogeneity index(HI),dosimetric parameters of the organ at risk(OAR),point dose verification pass rate,treatment time,number of monitor units and Sinograms.SPSS 22.0 was used for statistical analysis.Results For target area HI,there weres significant differences between CGS Fine plan and Coarse plan and between CGS Normal plan and Coarse plan(P＜0.05),while no statistical differences were found between CGS Fine plan and Normal plan(P＞0.05).For target area CI,there were significant differences between CGS Fine plan and Coarse plan(P＜0.05),while no statistical differences were found between CGS Fine plan and Normal plan and between CGS Normal plan and Coarse plan(P＞0.05).For OAR dosimetric parameters,CGS Fine plan and Coarse plan had significant differences in heart Dmax and Dmean,esophageal Dmax and Dmean,V5,V20,V30 and Dmean of the whole lung and affected lung,V5 and Dmax of the affected lung and heart V10 and V30(P＜0.05),CGS Normal plan and Coarse plan had obvious differences in esophageal Dmax(P＜0.05),and the remained dosimetric parameters were not statistically significant(P＞0.05).Fine,Normal and Coarse plans had the point dose verifica-tion pass rates being 0.96％,1.50％and 1.77％,respectively.In terms of treatment time and number of monitor units,there were significant differences between Fine plan and Coarse plan(P＜0.05)while no statistical differences were found between Fine and Normal plans and between Normal and Coarse plans(P＞0.05).Sinograms analyses showed Fine plan had evenly distributed segment color gradient,Coarse plan had areas of very dark and very light color gradients and Normal plan was somewhere in between.Conclusion Low CGS has to be used as much as possible to obtain accurate dose distribution during SBRT planning for NSCLC patients,which contributes to the execution of the radiation therapy plan and the prevention of ad-verse effects.[Chinese Medical Equipment Journal,2024,45(2):52-57]

Objective The aim of this study is to explore the potential modulatory role of quercetin against Endotoxin or lipopolysaccharide (LPS) induced septic cardiac dysfunction.Methods Specific pathogen-free chicken embryos (n = 120) were allocated untreated control, phosphate buffer solution (PBS) vehicle, PBS with ethanol vehicle, LPS (500 ng/egg), LPS with quercetin treatment (10, 20, or 40 nmol/egg, respectively), Quercetin groups (10, 20, or 40 nmol/egg). Fifteen-day-old embryonated eggs were inoculated with abovementioned solutions via the allantoic cavity. At embryonic day 19, the hearts of the embryos were collected for histopathological examination, RNA extraction, real-time polymerase chain reaction, immunohistochemical investigations, and Western blotting.Results They demonstrated that the heart presented inflammatory responses after LPS induction. The LPS-induced higher mRNA expressions of inflammation-related factors (TLR4, TNFα, MYD88, NF-κB1, IFNγ, IL-1β, IL-8, IL-6, IL-10, p38, MMP3, and MMP9) were blocked by quercetin with three dosages. Quercetin significantly decreased immunopositivity to TLR4 and MMP9 in the treatment group when compared with the LPS group. Quercetin significantly decreased protein expressions of TLR4, IFNγ, MMP3, and MMP9 when compared with the LPS group. Quercetin treatment prevented LPS-induced increase in the mRNA expression of Claudin 1 and ZO-1, and significantly decreased protein expression of claudin 1 when compared with the LPS group. Quercetin significantly downregulated autophagy-related gene expressions (PPARα, SGLT1, APOA4, AMPKα1, AMPKα2, ATG5, ATG7, Beclin-1, and LC3B) and programmed cell death (Fas, Bcl-2, CASP1, CASP12, CASP3, and RIPK1) after LPS induction. Quercetin significantly decreased immunopositivity to APOA4, AMPKα2, and LC3-II/LC3-I in the treatment group when compared with the LPS group. Quercetin significantly decreased protein expressions of AMPKα1, LC3-I, and LC3-II. Quercetin significantly decreased the protein expression to CASP1 and CASP3 by immunohistochemical investigation or Western blotting in treatment group when compared with LPS group.Conclusion Quercetin alleviates cardiac inflammation induced by LPS through modulating autophagy, programmed cell death, and myocardiocytes permeability.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Proto-Oncogene Proteins c-akt ; TOR Serine-Threonine Kinases ; GTP-Binding Protein alpha Subunits, Gi-Go/metabolism*

Objective:To explore clinical value of nucleic acid detection for hepatitis B virus (HBV) screening in hospitalized patients.Methods:This cross-sectional study collected and analyzed plasma samples from patients admitted to 10 domestic medical institutions from July 2021 to December 2021. Serological immunoassay and nucleic acid screening were used to simultaneously detect hepatitis B markers such as hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb), hepatitis B e Antigen (HBeAg), hepatitis B e antibody (HBeAb), hepatitis B core antibody (HBcAb),and HBV DNA. Statistical analysis was performed on the serology, nucleic acid test results and clinical information of the patients.Results:Of the 8 655 collected samples, HBsAg was positive in 216 (2.50%) samples,HBV DNA was positive in 238 (2.75%) samples ( P>0.05); 210 (2.43%) samples were positive for both HBsAg and HBV DNA, 28 (0.32%) were HBsAg negative and HBV DNA positive, 6 cases (0.07%) were HBsAg positive and HBV DNA negative. Conclusion:These results indicate that the HBV DNA testing is equally effective as hepatitis B virus serological detection for hepatitis B virus screening in hospitalized patients.

Objective:This multi-centre study was conducted to assess the efficacy of various preoperative/pre-transfusion screening methods for blood transmitted disease.Methods:From July 2021 to December 2021, plasma samples of patients admitted to 10 hospitals were collected for screening preoperative/pre-transfusion blood transmitted disease. Nucleic acid detection technology was used to detect hepatitis B virus (HBV) DNA, hepatitis C virus (HCV) RNA and human immunodeficiency virus (HIV)(1+2) RNA, and the results were compared with the immuno-serological methods. χ 2 test and Kappa test were used to analyze the efficacy of these two methods. Results:A total of 8 655 valid specimens were collected from 10 hospitals. There was a statistically significant difference in the positive detection rate of HCV between the two methods ( P<0.001). There was no significant difference in the positive detection rate of HBV and HIV assessed by the two methods ( P>0.05), but the number of positive cases detected by HBV DNA and HIV RNA (218 and 4 cases) was significantly higher than the corresponding serological results (216 and 2 cases). At the same time, there were HBV, HCV and HIV immuno-serological omissions by the immuno-serological methods, among which 28 cases were HBsAg negative and HBV DNA positive, 2 cases were HCV antibody negative and HCV RNA positive, and 2 cases were HIV antigen/antibody negative and HIV RNA positive. In addition, in the 66 samples with inconsistent results from the two detection methods, 83.3% (55/66), 68.2% (45/66), 63.6% (42/66) and 62.1% (41/66) of patients aged was>45 years, tumor, surgery and male, respectively. Conclusions:Compared with immuno-serological tests, nucleic acid tests have the advantage in terms of sensitivity on detecting HBV, HCV and HIV infection and could reduce missed detection. The risk of transmission can be reduced by adding HBV, HCV, and HIV nucleic acid tests to preoperative/pre-transfusion immuno-serological tests screening for patients over 45 years of age and tumor patients.

Objective:To compare the cost-effectiveness of hospitalized Chinese patients undergoing nucleic acid screening strategies for hepatitis B and hepatitis C, immunological screening strategy, and no screening strategy under different willingness to pay (WTP). The results might aid to decision-making for the optimal strategy.Methods:In this study, nucleic acid screening, immunological screening and no screening were used as screening strategies, and China′s GDP in 2021 (80 976 yuan) was used as the threshold of WTP to construct a Markov model. After introducing parameters related to the diagnosis and treatment of hepatitis B and C in inpatients, a cohort population of 100 000 inpatients was simulated by TreeAge Pro 2021 software, the total cost, total health effects, incremental cost-effectiveness ratio and average cost-effectiveness ratio of different screening strategies were calculated, and cost-effectiveness analysis was conducted. Univariate and probabilistic sensitivity analysis were used to assess the impact of parameter uncertainty on the final results.Results:Compared with the non-screening strategy, the incremental total cost of the hepatitis B immunological screening strategy for cohort patients was 11 049 536 yuan, and the incremental cost-effectiveness ratio was 24 762 yuan/quality-adjusted life years (QALY), while the total incremental cost of nucleic acid screening was 19 208 059 yuan, and the incremental cost-effectiveness ratio was 29 873 yuan/QALY; the incremental cost-effectiveness ratio of nucleic acid screening and immunological screening was 45 834 yuan/QALY. Compared with the non-screening strategy, the incremental cost-effectiveness ratio of hepatitis C immunological screening strategy was 5 731 yuan/QALY, the incremental cost-effectiveness ratio of nucleic acid screening strategy was 8 722 yuan/QALY, the incremental cost-effectiveness ratio of nucleic acid screening and immunological screening was 45 591 yuan/QALY. The results of probabilistic sensitivity analysis showed that when the cost of nucleic acid testing exceeded 214.53 yuan, it was not cost-effective to perform hepatitis B nucleic acid screening under the WTP as 1 fold GDP. When the cost of nucleic acid testing exceeded 132.18 yuan, it was not cost-effective to conduct hepatitis C screening under the WTP as 1 fold GDP.Conclusions:Nucleic acid screening strategy can achieve more cost-effectiveness and is worthy of vigorous promotion. Compared with no screening, both the nucleic acid and immunological screening strategies are cost-effective, and hepatitis nucleic acid screening is the optimal strategy for hospitalized patients.