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.

Objective:To analyze the risk factors associated with death in children with severe pneumonia admitted to the pediatric intensive care unit (PICU), investigate the predictive value of the modified PIRO (mPIRO) scale in assessing the risk of death in these children, and improve the scale appropriately.Methods:In this case-control study, a retrospective analysis was conducted on the clinical data of 460 children with severe pneumonia in the PICU at Children′s Hospital of Chongqing Medical University from May 2015 to December 2021.Based on the occurrence of death, these children were divided into a survival group ( n=411) and a death group ( n=49).Logistic regression analysis was performed to identify the risk factors associated with death in children with severe pneumonia in the PICU.The mPIRO scale was employed to evaluate the mortality risk, wherein the pulse oxygen saturation (SpO 2)<0.90 of the scale was revised to the ratio of SpO 2/fraction of inspired oxygen≤160 to form the modified scale.The predictive effect of both scales was compared using the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA). Results:The Logistic regression analysis revealed hypotension, acute hepatic failure, acute kidney injury, acute respiratory distress syndrome, and elevated blood glucose were independent risk factors for death in children with severe pneumonia in the PICU (all P<0.05).The ROC curve demonstrated that the area under the curve (AUC) of the modified scale was 0.747, significantly higher than that of the mPIRO scale (AUC=0.718, P<0.05).The calibration curve illustrated that the modified scale had a better fit between the predicted result and the actual result.The DCA revealed that the modified scale had a higher net benefit compared to the mPIRO scale at probability thresholds of 0.1 to 0.4. Conclusions:Hypotension, acute hepatic failure, acute kidney injury, acute respiratory distress syndrome, and elevated blood glucose are identified as independent risk factors for death in children with severe pneumonia in the PICU.Both the mPIRO scale and the modified scale show predictive value in assessing mortality risk for children with severe pneumonia in the PICU, with the modified scale demonstrating superior performance.

Objective To investigate the effects and underlying mechanisms of NaNO2 on oxidative damage in human bronchial epithelial cells pretreated with house dust mite(HDM).Methods Human bronchial epithelial cell line 16HBE were pretreated with HDM and then exposed to varying concentrations of NaNO2.Cell viability was assessed using CCK-8 assay to determine the optimal concentration and treatment duration of NaNO2.Then 16HBE cells were randomly divided into normal control group,HDM group(pretreated with HDM),and NaNO2 group(pretreated with HDM followed by NaNO2 exposure).The expression of Krüippel-like transcription factors 2(KLF2),hypoxia-inducible factor-1α(HIF-1α),and Notch1 at protein and mRNA levels in each group were measured by Western blotting and RT-PCR,respectively.The contents of the inflammatory cytokines IL-6 and TNF-α were assessed using ELISA.The production of reactive oxygen species(ROS)were measured using a fluorescence probe detection.The contents of malondialdehyde(MDA)and glutathione(GSH)were quantified by micro-methods.Results CCK-8 assay determined that the optimal intervention of NaNO2 was 500 μmol/L for 24 h.Compared with the normal control group,the HDM group showed reduced protein and mRNA expression of KLF2,but increased protein and mRNA(P＜0.01)expression of HIF-1α,and Notch1 at protein(P＜0.05)and mRNA levels,elevated production of ROS(P＜0.01),and increased contents of MDA,TNF-α,and IL-6,with a decrease in GSH content(P＜0.05).Compared with the HDM group,the NaNO2 group exhibited a significant reduction in KLF2 protein and mRNA levels,increases in HIF-1α protein and mRNA levels,Notch1 protein(P＜0.05)and mRNA levels,elevated ROS content(P＜0.01),and significantly increased contents of MDA,TNF-α(P＜0.001),and IL-6,with a notable decrease in GSH content(P＜0.05).Conclusion NaNO2 may exacerbate HDM-induced oxidative stress injury in human bronchial epithelial cells by regulating the expression of KLF2.

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.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Objective:To investigate the optimal monochromatic level for evaluation of in-stent lumen after transjugular intrahepatic portosystemic shunt (TIPS) by dual-layer detector CT.Methods:Twenty-nine patients after TIPS were retrospectively enrolled who underwent abdomen enhanced examinations with portal venous phases by a dual-layer detector CT between December 2019 and July 2021. The mixed iterative image (conventional group) and monochromatic images (40 keV group, 50 keV group, 60 keV group and 70 keV group) were obtained by reconstruction. Circular regions of interest were placed in the in-stent of the cross-sectional reconstructed image and in the vertical spinal muscle on the same plane to obtain the corresponding average CT value and noise. The contrast to noise ratio (CNR) and signal to noise ratio (SNR) were calculated. Then 4-point scale was performed to evaluate image quality subjectively by 2 physicians blindly and separately. One-way ANOVA or Kruskal Wallis H rank-sum test was used for the overall analysis between groups, and LSD test or Dunn′s Bonforoni test was used for pairwise comparison within groups. Results:There was no significant difference in noise values among the 5 groups ( P>0.05). The difference of CNR and SNR between the 5 groups was statistically significant ( F=72.28, 56.45, P<0.001). The CNR and SNR in the 40 keV group were the highest, which were 50.4±15.7 and 59.3±18.4 respectively, and the difference was statistically significant ( P<0.001). Subjective scores showed statistically significant differences among the 5 groups (χ2=101.61, P<0.001). The score of the 40 keV group was higher than that of the 60 keV group, 70 keV group, and conventional group ( P<0.001), and there was no significant difference when compared with the subjective score of the 50 keV group ( P>0.05). Conclusions:The 40 keV monochromatic image of dual detector spectral CT is the best image to observe the lumen of the stent after TIPS.

Interstitial lung disease(ILD) is a group of pulmonary diseases including clinical common diseases and clinical rare diseases.The etiology of some of these diseases is unknown, and drug treatment is difficult, so stem cell transplantation is considered to treat ILD.Stem cells have the advantage of chemotaxis to damaged tissues, so stem cell transplantation for ILD is feasible.In recent years, the research of stem cell transplantation for treatment of ILD has been increasing gradually, but the review of stem cell transplantation for treatment of ILD in children is scarce.This paper reviews the recent advances in the treatment of ILD by stem cell transplantation, including the pathological features, treatment, prognosis and application prospects.

In recent years, the incidence of idiopathic pulmonary fibrosis has been increasing year by year.Although traditional drugs have been shown to be effective in preventing process of pulmonary fibrosis, their side effects are high and application is limited.Cell, cytokine, and epithelial-mesenchymal transition all participate in the process of pulmonary fibrosis, and HDAC8 also plays an important role in these related processes.The researchers found that HDAC8 contributes to pulmonary fibrosis, and that HDAC8 inhibitors have the potential to treat IPF and other fibrotic lung diseases.In this paper, the research progress of the relationship between HDAC8 gene and idiopathic pulmonary fibrosis in recent years is reviewed.

Juvenile dermatomyositis is a systemic autoimmune vascular disease characterized by rash and proximal myopathy.Pulmonary complications related to this disease include interstitial lung disease, aspiration pneumonia, respiratory muscle involvement, airway involvement, pleural involvement, pulmonary hypertension and mediastinal emphysema .Interstitial lung disease is the most common pulmonary involvement in juvenile dermatomyositis, which often affects the prognosis of children.Adult myositis associated interstitial lung disease has been well described in the literature, but the description of juvenile dermatomyositis associated interstitial lung disease is still lacking.This review discusses the pathogenesis, pathological types, biological markers, diagnosis, treatment and monitoring of juvenile dermatomyositis related interstitial lung disease.

Objective To explore the influence of the selecting questions from national question database on the Pediatrics theoretical examination of clinical undergraduates under the mode of teaching-examination separation. Methods to make an overall quantitative analysis of 304 test papers, selecting questions from national question database for the final pediatrics theoretical examination in the first term from 2017 to 2018, which was answered by two classes of clinical medicine students enrolled in 2014. Results From the distribution of these two classes' scores, it can seen that the frequency distribution on both sides of the average is relatively symmetrical and all of them presented normal distribution, but they are all below average and good grades are fewer. They account for 5.29% and 9.15% of the total number respectively in each class. The number of students who failed of the two classes accounts for 20.53% and 16.99% respectively. The difficulty coefficients of the total volume are respectively 0.67 and 0.69, whose overall difficulty is moderate. Moreover, the test reliability coefficients of two classes are 0.764 0 and 0.768 9 respectively. The discrimination of the total volume of these two classes are all 0.22. There are some errors for the examination papers including in multiple choice options, repetitive questions, too many ques-tions in circulatory system and questions above student current levels. Conclusion The result indicates that the testing questions show the difference of the students' ability and the reliability of the test through the overall quantitative analysis of the test. However, relatively low scores and a relatively large number of students failing the test indicate that students just stay in the old teaching and testing mode and they only master classroom knowledge. Therefore, they do not do self-learning well. Separation of teaching and testing could help to cultivate students' self-learning ability. At the same time, the quality of examination questions of the national question database and group questions should be constantly improved, which is the premise to ensure the objective reflection of students' learning ability.