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 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 clinical efficacy of complete mesogaster excision in the radical gastrectomy for gastric cancer.Methods The clinical data of 100 patients with distal gastric cancer who were admitted to the First Affiliated Hospital of Harbin Medical University from January 2011 to December 2012 were retrospectively analyzed.All the patients underwent complete mesogaster excision in D2 radical gastrectomy for gastric cancer.The operation quality was evaluated according to operation time,volume of intraoperative blood loss,mean number of lymph nodes dissected,time to flatus,volume of drainage and duration of postoperative hospital stay.Patients were followed up by outpatient examination and telephone interview till May 2014.Results Complete mesogaster excision in the radical gastrectomy for gastric cancer was successfully carried out on all the 100 patients.The operation time,volume of intraoperative blood loss,mean number of lymph nodes dissected,time to flatus,volume of drainage and duration of postoperative hospital stay were (118 ± 34) minutes (range,90-160 minutes),(80±25)mL (range,45-135 mL),38± 10 (range,25-52),(3.0 ± 1.2)days (range,1.5-4.5 days),(62±15)mL (range,15-85 mL) and (7.0±1.5)days (range,4.0-11.5 days),respectively.According to the postoperative pathological results,there were 36 patients with high differentiated gastric carcinoma,38 with moderate and/or low differentiated gastric carcinoma,17 with low differentiated gastric carcinoma and 9 with signet ring cell carcinoma.After operation,3 patients had gastroplegia,2 with poor healing of abdominal incision,2 with duodenal stump fistula,1 with pancreatic fistula,and all of them were cured by conservative treatment.All the 100 patients were followed up for a mean time of 25.6 months (range,17.6-39.2 months).There was no tumor recurrence.Conclusions Complete mesogaster excision in the radical gastrectomy for gastric cancer is safe and feasible,with the advantage of minimal trauma,low morbidity and quick recovery during the follow up.

Objective To evaluate No.16a2b1 lymphadenectomy for D2 gastrectomy of advanced gastric cancer.Methods In this study,we retrospectively analysed the data of 100 patients with advanced gastric cancer from April 2004 to April 2005.All the patients were in stage T3-4.50 patients underwent D2 plus No.16a2b1 lymphadenectomy while the other 50 patients underwent standard D2 operation.Results The metastatic rate of No.16a2b1 lymph node was 18％ ;The bleeding volume,operation time,postoperative intestinal function recovery time and the incidence of postoperative complications between D2 plus No.16a2b1 lymphadenectomy group and standard D2 operation group were [(351 ± 121) ml vs.(305 ±-105) ml,t=2.03],[(192±50) vs.(172±40),t=2.22],[(5 ±2) days vs.(4±-2) days,t=3.33],and [10％ (5/50) vs.8％ (4/50)] respectively.All differences were not statistically significant (P ＞0.05).While 5 year survival rates were 24％ (12/50) vs.6％ (3/50) respectively,the difference was statistically significant (P ＜ 0.05).Conclusions No.16a2b1 lymphadenectomy is necessary,feasible and prolongs survival for advanced gastric cancer patients,especially in stage T3 and T4 undergoing D2 operation.

Objective To investigate sensitivity of colon cancer cells to 5-fluorouracil after downregulation of XIAP gene expression. Method Colon cancer cells HCT-8 and HCT116 were transfected with a short hairpin RNA targeted to XIAP by liposome, cells viability were examined.5-fluorouracil was applied into two kinds of colon cancer cells. Tumor cells sensitiviy to chemotherapeutic drug was evaluated. Caspase-3 activity in tumor cells was examined by Western blot. Result After downregulation of XIAP expression, cell growing viability of these two kinds of colon cancer cells was restricted, HCT-8 resistance to 5-fluorouracil was reversed ( P ＜ 0. 01 ), HCT116 sensitivity to 5-fluorouracil was enhanced (P ＜ 0.05), caspase-3 expression in colon cancer cells was highly activated, apoptosis inducing activity of 5-fluorouracil was increased significantly. Conclusions XIAP expression was a important mechanism in colon cancer cells HCT-8 and HCT 116 resistant to 5-fluorouracil, sensitivity to 5-fluorouracil of HCT-8 and HCT-116 was increased by downregulation of XIAP expression.

Objective To investigate the reversal effect of the monomer of traditional Chinese medicine on muhidrug resistance(MDR) and its possible mechanism in K562/ADM cell line in vitro. Methods With different concentrations of baicalin, geniposide administered to K562/ADM cells, the proliferation of K562/ ADM cells was detected by the MTY assay. Expression of mdr-1 mRNA, Topo Ⅱ mRNA was measured by semi-quantitive RT-PCR. Results Thatbaicalin and geniposide could increase the sensitivity of K562/ADM cells to adriamycin, multiples of reversion were 1.95 times and 1.46 times. The proliferation of K562/ADM cells was in-hibited obviously by baicalin and geniposide, the level of mdr-1 mRNA expression was down-regulated and the Topo Ⅱ mRNA was up-regulated(P<0.01 ). Conclusion Baicalin and geniposide may reverse the multi-drag-resistance of K562/ADM cells, which was related to the down-regulation of mdr-1 expression and up-reg-ulation of Topo Ⅱ beta expression.

Objective To explore molecular mechanism of expression of vascular endothelial growth factor (VEGF) mRNA and secretion of VEGF protein in HL-60 cells induced by all-trans refinoic acid (ATRA). Methods MTr method was used to detect the proliferation of HL-60 cells induced by ATRA,cell cycle and CD11b expression in HL-60 cells were detected by flow cytometry. Expression of VEGF, c-myc, by-poxia-inducible factor(HIF)-lα, matrix metalloproteinase (MMP)-9 and MMP-2 mRNA were detected by semi-quantitative RT-PCR. VEGF protein in HL-60 cells culture supernatant was measured by ELISA before and after being induced by ATRA. Results After treatment with ATRA,the proliferation of HL-60 cells was obviously inhibited, CD11b expression increased, trend of granulocyte directional differentiation emerged, and differentiation degree was increasd(P <0. 05) ;expression level of c-my and VEGF mRNA was down-regulated (P < 0. 05), but expression level of HIF-1α mRNA was up-regulated (P < 0. 05). VEGF protein level in HL-60 cells culture supernatant was decreased by blocking the expression of MMP-9 or MMP-2(P <0. 05).Conclusion VEGF expression has positive correlation with c-myc expression,but has negative correlation with HIF-1α expression. MMP-9 and MMP-2 may be the main factors regulating VEGF secretion in HL-60 cells.

Objective To study the molecular mechanism of different sensitivities to apoptosis induced by low concentration of As2O3 in PML-RARα negative HL-60 cells and PML-RARα positive NB4 cells. Meth-ods NB4 and HL-60 cells were cultured with As2O3 for 1 to 4 days; cell proliferation were detected by MTT method; the apoptosis was detected by flow cytometry,Bcl-2,Bax and Fas mRNA were determined by RT-PCR. Results The proliferation of NB4 cells was inhibited obviously by As2O3(1.0 μmol/L)with the induction of apoptosis( P <0.05) ,which was accompanied by the down-regulation of Bcl-2 mRNA expression( P <0.05)and the ratio of Bcl-2/Bax(P <0.05), but there was no obvious variation of Bax and Fas expression( P >0.05). Inhibition of proliferation and apoptosis were not obvious in PML-RARα negative HL-60 cells induced by low concentration As2O3 ( P >0.05), and there was no obvious variation of Bcl-2, Bax, Fas mRNA expres-sion or Bcl/Bax ratio( P >0.05). Conclusion The ratio of Bcl-2/Bax is contributed to the different sensitiv-ities of PML-RARα negative HL-60 cells and positive NB4 cells induced by low concentration of As2O3.

Objective To detect the synergetic effect and mechanism of arsenic trioxide(As2O3)and Trichostatin A(TSA)during inducing apoptosis of HL-60 cells.Methods MTT method was used to test the proliferation of HL-60 cells.Cell cycle and apoptosis were detected by FCM.Semi-quantitative RT-PCR was used to detect the mRNA expression of Bax and Bcl-2 in the cells treated by As2O3 and(or)TSA.Results As2O3 combined with TSA could inhibit proliferation and induce cell cycle arrest at G0 and G1.The percent of apoptosis induced by combination of As2O3 and TSA was obviously higher than that of either As2O3 or TSA.Bax gene expression was increased,while Bcl-2 gene expression was decreased,Bax/Bel-2 ratio was up-regulated.Conclusion Synergetic effect by As2O3 and TSA is remarkable in inducing apoptosis of HL-60 cells.Cell cycte arrest and Bax/Bcl-2 ratio play an important role in apoptosis of HL-60 cells induced by As2O3,TSA or their combination.

Aged ; Anastomosis, Surgical ; Duodenum ; blood supply ; surgery ; Female ; Gastrointestinal Hemorrhage ; etiology ; surgery ; Humans ; Hypertension, Portal ; complications ; Jejunum ; surgery ; Rupture, Spontaneous ; Varicose Veins ; complications