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.

With the acceleration of industrialization,the issue of heavy metal pollution has become increasingly severe,and the potential threat to the ecological environment and human health is increasing.It is necessary and important to detect the contents and species of heavy metal ions.To reduce the influence of complex sample matrices and enrich low contents of analytes,suitable sample pretreatment is usually required before analysis.In recent years,magnetic solid phase extraction(MSPE)based on magnetic extraction materials prepared by rational design and functional modification have attracted much attention in the analysis of heavy metal ions due to their high selectivity,satisfactory adsorption capacity and efficient separation ability.In this paper,the application progress of magnetic composite materials based on ion imprinted polymers,chitosan,metal organic frameworks,ionic liquids and other polymers in the extraction of heavy metal ions from environmental water samples,seafood,radioactive waste and food in recent years was reviewed.The current review focused on the preparation of representative materials in the same category and their adsorption performance towards heavy metal ions.The challenges were analyzed and the future development trend was also prospected.

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 investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

Objective:To analyze the risk factors for late-onset hemorrhagic cystitis(LOHC)after allogeneic hematopoietic stem cell transplantation(allo-HSCT),the risk factors for the progression of LOHC to severe LOHC,and the effect of LOHC on survival.Methods:The clinical data of 300 patients who underwent allo-HSCT at the First Affiliated Hospital of Chongqing Medical University from January 2015 to December 2021 were retrospectively analyzed.The relevant clinical parameters that may affect the occurance of LOHC after allo-HSCT were selected for univariate and multivariate analysis.Then,the differences in overall survival(OS)and progression-free survival(PFS)between different groups were analyzed.Results:The results of multivariate analysis showed that the independent risk factors for LOHC after allo-HSCT were as follows:age≤45 years old(P=0.039),intensified conditioning regimen with fludarabine/cladribine and cytarabine(P=0.002),albumin ≤ 30 g/L on d30 after transplantation(P=0.007),CMV-DNA positive(P=0.028),fungal infection before transplantation(P=0.026),and the occurrence of grade Ⅱ-Ⅳ aGVHD(P=0.006).In the transplant patients who have already developed LOHC,the occurance of LOHC within 32 days after transplantation(P=0.008)and albumin ≤ 30 g/L on d30 after transplantation(P=0.032)were independent risk factors for the progression to severe LOHC.The OS rate of patients with severe LOHC was significantly lower than that of patients without LOHC(P=0.041).Conclusion:For the patients aged ≤ 45 years old and with intensified conditioning regimen,it is necessary to be vigilant about the occurrence of LOHC;For the patients with earlier occurrence of LOHC,it is necessary to be vigilant that it develops into severe LOHC.Early prevention and treatment of LOHC are essential.Regular monitoring of CMV-DNA and albumin levels,highly effective antiviral and antifungal therapies,and prevention of aGVHD are effective measures to prevent the occurrence and development of LOHC.

Objective:RS4;11 cell line was used to establish BCL-2 inhibitor-resistant cell lines of B-cell acute lymphoblastic leukemia(B-ALL)and explore the possible mechanisms of drug resistance.Methods:RS4;11 cell line was continuously induced and cultured by low and ascending concentrations of BCL-2 inhibitors navitoclax and venetoclax to construct navitoclax-resistant cell line RS4;11/Nav and venetoclax-resistant cell line RS4;11/Ven.The cell viability was detected by MTT assay,and the cell apoptosis was detected by flow cytometry.Differentially expressed genes(DEGs)between RS4;11 drug-resistant cell lines and parental cell line were detected by transcriptome sequencing technology(RNA-seq),and mRNA expression levels of DEGs between drug-resistant cell lines and parental cell line were detected by real-time PCR(RT-PCR).Western blot was used to detect the expression levels of BCL-2 family anti-apoptotic proteins in drug-resistant cell lines and parental cell line.Results:The drug-resistant cell lines RS4;11/Nav and RS4;11/Ven were successfully established.The resistance index(RI)of RS4;11/Nav to navitoclax and RS4;11/Ven to venetoclax was 328.655±47.377 and 2 894.027±300.311,respectively.The results of cell apoptosis detection showed that compared with the drug-resistant cell lines,RS4;11 parental cell line were significantly inhibited by BCL-2 inhibitors,while the apoptosis rate of drug-resistant cell lines was not affected by the drugs.Western blot assay showed that the expression of anti-apoptotic proteins of BCL-2 family did not increase significantly in drug-resistant cell lines.RNA-seq,RT-PCR and Western blot assays showed that the expression of EP300 in drug-resistant cell lines was significantly higher than that in parental cell line(P＜0.05).Conclusion:Drug-resistant B-ALL cell lines could be successfully established by exposing RS4;11 cell line to the ascending concentration of BCL-2 inhibitors,and the drug resistance mechanism may be related to the overexpression of EP300.

Objective:To evaluate the gene mutation profile and prognostic significance of adult cytogenetically normal acute myeloid leukemia (CN-AML) with CEBPA-bZIP mutation. Methods:Targeted sequencing was implemented on the diagnostic bone marrow DNA samples of 141 adult CN-AML subjects with CEBPA-bZIP mutation. The nomogram model for leukemia-free survival (LFS) rate was generated by combining genetic abnormalities and clinical data. Risk stratification was conducted based on prognostic variables and the effect of risk-adjusted consolidation therapy was investigated by Kaplan-Meier method. Results:Four variables were finally included in our nomogram model after multivariate Cox analysis,and an equation for risk score calculation was obtained,risk score=1.3002×white blood cell (WBC) (≥18.77×109/L)+1.4065×CSF3R mutation positive+2.6489×KMT2A mutation positive+1.0128×DNA methylation-related genes mutation positive. According to the nomogram model,patients were further divided into low-risk group (score=0,n=46) and high-risk group (score>0,n=95). Prognostic analysis showed that the 5-year LFS rate,5-year overall survival (OS) rate,and 5-year cumulative incidence of relapse (CIR) of patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the high-risk group were 93.5％,97.1％,and 3.5％,while those in patients who received maintenance chemotherapy were 32.9％,70.5％,and 63.4％,respectively. The differences were statistically significant (all P<0.05). Allo-HSCT could significantly improve the prognosis of patients in high-risk group. However,no corresponding benefit was observed in the low-risk group. Conclusion:Adult CN-AML with CEBPA-bZIP mutation has a complex co-mutation pattern. The nomogram model based on mutations of CFS3R,KMT2A and DNA methylation-related genes together with WBC count can further divide this subset of patients into a relatively low-risk group and a relatively high-risk group. For individuals in the high-risk group,allo-HSCT is proposed as post-remission therapy. The above data will benefit the prognosis estimation and treatment decision for adult CN-AML with CEBPA-bZIP mutation.

Objective:To analyze the risk factors of primary poor graft function (PGF) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with myeloid malignancies and the impact of primary PGF on survival. Methods:The clinical data of 146 patients with myeloid malignancies who underwent allo-HSCT in our hospital from January 2015 to December 2021 were retrospectively studied. Some relevant clinical parameters which may affect the development of primary PGF after allo-HSCT were selected for univariate and multivariate analysis,as well as performed survival analysis. Results:A total of 9 patients (6.16％) were diagnosed with primary PGF,and their medium age was 37(28-53) years old. Among them,1 case underwent matched sibling donor HSCT,1 case underwent matched unrelated donor HSCT,and 7 cases underwent HLA-haploidentical related donor HSCT. Moreover,5 cases were diagnosed as cytomegalovirus (CMV) infection,and 3 cases as Epstein-Barr virus (EBV) infection. Univariate and multivariate analysis showed that CD34+cell dose<5×106/kg and pre-transplant C-reactive protein (CRP)>10 mg/L were independent risk factors for occurrence of the primary PGF after allo-HSCT in patients with myeloid malignancies. The 3-year overall survival (OS) rate of primary PGF group was 52.5％,which was significantly lower than 82.8％ of good graft function group (P<0.05). Conclusion:Making sure pre-transplant CRP≤10 mg/L and CD34+cell dose ≥5×106/kg in the graft may have an effect on preventing the occurrence of primary PGF after allo-HSCT. The occurrence of primary PGF may affect the OS rate of transplant patients,and early prevention and treatment are required.

Aim To establish limited sampling strategy to esti-mate area under the drug concentration versus time curve(AUC0-t)of lymphoma patients treated with autologous stem cell transplantation(ASCT)who had busulfan intravenous infu-sion.Methods Twelve lymphoma patients treated with ASCT received a conditioning regimen containing busulfan 105 mg·m-2,Ⅳ infusion for 3 h.Blood samples were obtained 1 h after the start of the first dose of the busulfan infusion,at 5 min,1 h,2 h,4 h,6 h and 18 h after the end of the drug administration.LC-MS/MS was used to determine the busulfan serum concentra-tion.After obtaining the clinical pharmacokinetic parameters of busulfan by traditional pharmacokinetic method,multiple linear stepwise regression analysis was used to establish the AUC0-t es-timation model of busulfan based on limited sampling method.The model was further verified by Jackknife and Bootstrap meth-od.Bland-Altman plots were used to evaluate the consistency between the limited sampling method and the classical pharma-cokinetic method.Results The multiple linear regression equa-tion analysis of C60min,C180min and C300min was obtained by the limited sampling method.The regression equation was AUC0-t=295.003C60min+233.050C180min+273.163C300min-1202.713,r2=0.995,MPE=-0.87％,RMSE=2.40％.Conclusion The limited sampling model with three-point estimation can be used to estimate the AUC0-t of busulfan exposure in lymphoma patients with ASCT to provide reference for clinical application of busulfan.

Twelve compounds were isolated from Liquidambaris Resina by silica gel column chromatography and thin layer chromatography. Their structures were identified on the basis of spectral data, electron capture detector data, and physicochemical properties as(2'R, 3'R)-2',3'-dihydroxy-hydrocinnamyl-(E)-cinnamate(1),(E)-cinnamyl-(E)-cinnamate(2), cinnamic acid(3), 28-norlup-20(29)-en-3-one-17β-hydroperoxide(4), erythrodiol(5), 13β,28-epoxy-30-hydroxyolean-1-en-3-one(6),(3β)-olean-12-ene-3,23-diol(7), 2α,3α-dihydroxy-olean-12-en-28-oic acid(8), 28-hydroxyolean-12-en-3-one(9), 3-epi-oleanolic acid(10), 3-oxo-oleanolic acid(11), and hederagenin(12). Compound 1 was a new cinnamic acid ester derivative and compounds 2-4,6-8, and 12 were isolated from Liquidambaris Resina for the first time. Compounds 4, 5, 10, and 12 exerted inhibitory effects on the proliferation of human umbilical vein endothelial cells(HUVEC) with the IC_(50) values of(17.43±2.17),(35.32±0.61),(27.50±0.80), and(46.30±0.30) μmol·L~(-1), respectively.
Humans ; Oleanolic Acid ; Endothelial Cells ; Esters ; Cinnamates ; Triterpenes/chemistry* ; Molecular Structure