Objective: To investigate the role of endogenous nitric oxide (NO) in the pulmonary edema caused by overinfusion of colloid. Method: Forty healthy rabbits were randomly allocated into (Ⅰ) control group, (Ⅱ) infusion control group: one fold total blood volume of Gelofusine was infused at 2ml?kg~(-1)?min~(-1)(Ⅲ)L-NNA group:LNNA 20 mg/kg was intravenously injected before infusion, (Ⅳ)L-Arg+L-NNA group:L-arginine 300mg/kg and LNNA 20 mg/kg was intravenously injected before infusion. MAP,HR and CVP were recorded during the experiment, arterial blood gas analysis was examined before and after infusion,serumal NO value and lung water content were measured at the end of the experiment. Result: Overinfusion of colloid,L-NNA,an inhibitor of NO synthesis increased the extravascular lung water (EVLW) content and decreased NO value,meanwhile CVP increased,HR,PaO_2 and SaO_2 decreased,excess dose of L-arginine completely reversed the effect of L-NNA. Serumal NO value was negatively correlated with EVLW content (r=-0.94). EVLW content was significantly correlated with total lung water (r=0.41). Conclusion:Endogenous NO can reduce the pulmonary edema caused by overinfusion of colloid.

Objective To investigate pulmonary infect flora distribution characteristics of stroke patients with tracheotomy in Intensive care unit (ICU) and analyze the risk factors.Methods A total of 792 cases of ICU stroke patients was selected,including 426 cases of tracheotomy patients,and 366 cases of non-tracheotomy patients.The incidence of lung infections was compared.Bacteriological examination was used for tracheotomy bacteriological studies for lung infected stroke patients with tracheotomy.Bacteria infection's characteristics was observed.The risk factors were analyzed.Results (1) The tracheotomy patient 's lung infection rate was 23.00％,higher than 9.56％ of the non-tracheotomy patients,the difference was statistically significant (X2 =19.125,P ＜0.05);(2) For lung infection-occurred patients with tracheotomy of ICU,gram-negative bacteria infection rate was 63.97％,significantly higher than 19.85％ of gram-positive bacteria and 16.18％ of fungi,the difference was statistically significant (x2 =18.255,17.042,P ＜ 0.01);(3) Lung infection rate of ICU stroke tracheotomy patients with unconscious,dysphagia,hospitalization time ＞ 14 d,blood glucose levels ≥≥7.8 mmol/L,and based diseases was significantly higher than that of patients with conscious,non-dysphagia,hospitalization time ≤＜14 d,blood sugar level ＜7.8 mmol/L,and no based diseases (P ＜ 0.05);(4) Consciousness,dysphagia,hospitalization,blood sugar levels,and the underlying disease were the independent risk factors of lung infection in ICU stroke tracheotomy patients (OR1 =11.528,OR2 =8.046,OR3 =15.174,OR4 =7.795,ORs =10.784,P ＜0.05).Conclusions Gram-negative bacteria is the main reason for pulmonary infections in ICU stroke tracheotomypatients patients with stroke.State of consciousness,invasive treatment,hospitalization,blood sugar levels,and the underlying disease are the independent risk factors.

Objective To evaluate the efficacy of rituximab-containing regimens on post-transplantation lymphoproliferative disorder (PTLD) following haploidentical hematopoietic stem cell transplantation (HSCT). Methods The clinical data of 3 cases of PTLD after haploidentical HSCT were analyzed retrospectively. Time to development of PTLD ranged from 57 to 164 days after HSCT.The main symptoms included fever, superficial lymph node enlargement. Epstein-Bart virus (EBV)-positive B-cell PTLD was diagnosed by biopsy of lymph node. Management of 3 patients consisted of withdraw of immunosuppressive treatment, anti-viral therapy, rituximab (375 rng/m2 , per week for four weeks) monotherapy or chemotherapy plus rituximab. Results All the patients had complete remission after treatment. Conclusion PTLD is a serious complication of HSCT especially haploidentical HSCT. Rituximab-containing regimens are potentially effective, well-tolerated with mild toxicity and improve the prognosis of PTLD following haploidentical HSCT.

Objective This study aimed to establish a reliable primary culture protocol for preparing murine spleen-derived mesenchymal stem cells ( MSCs) by tissue explant culture.Methods Healthy mouse spleens were crushed by syringe handle to harvest spleen mesenchymal tissues.Then the tiny pieces of spleen tissue were digested by collagenase II before seeded into culture flasks.The morphological characteristics of spleen tissue-derived cells were observed under the inverted microscope.Further, the surface antigen profile of the cells was analyzed by flow cytometry (FACS).The cells were induced to differentiate into osteoblasts and adipocytes.Results The murine spleen-derived MSCs exhibited a spindle-shaped appearance.The FACS results showed that the spleen-derived MSCs highly expressed CD29, CD44, CD105 and Sca-1, but weakly expressed CD11b, CD34, CD45 and Ia. In addition, the spleen-derived MSCs steadily differentiated into osteoblasts and adipocytes in the induction medium.Conclusions A method of primary culture of murine spleen-derived MSCs by explant culture is successfully established.The harvested MSCs exhibit high purity and cell proliferation ability, and provide a reliable cell model for related researches.

BACKGROUND:Spinocerebel ar ataxia is a inherited neurodegenerative disease with progressive cerebel ar masonic movement disorders as the main clinical manifestation. So far, no drug is available to control the disease progression. OBJECTIVE:To observe the clinical effect of umbilical cord mesenchymal stem cells in treating spinocerebel ar ataxia by intrathecal injection. METHODS:Thirty-eight cases of spinocerebel ar ataxia were given umbilical cord mesenchymal stem cells by intrathecal injection, 1×106/kg once a week, four times as a course. These 38 cases received 52 courses. Among them, 27 cases received 1 course, 8 cases received 2 courses and 3 cases received 3 courses. International Cooperative Ataxia Rating Scale (ICARS) and Activity of Daily Living Scale (ADL) were used to evaluate patients’ neural functions (the greater scores, the more severe damage) and ability of daily living (the lower score, the stronger the ability of daily living). After treatment, al patients were subjected to fol ow-up visit. RESULTS AND CONCLUSION:The total effective rate of 52 courses of treatment was 84.62%. ICARS and ADL scores were significantly decreased at 1 month after treatment (P<0.01). In most of effective patients, unstable walking and standing, slow movement, upper limb fine motor disorder, writing difficulties, dysarthria, eye movement disorders were improved. After treatment, common adverse effects were dizziness (1 case), low back pain (2 cases), headache (1 case), and fever (2 cases). Al these symptoms disappeared within 1-3 days. No treatment-related adverse events happened in the median fol ow-up of 39 months (11-59 months). The il ness of effective patients had been stable for 1-19 months, average (5.95±4.84) months. Intrathecal injection of umbilical cord mesenchymal stem cells is safe to ameliorate clinical symptoms to some extent within a certain time. It may delay the progression of spinocerebel ar ataxia. Multiple courses of treatment can help to further improve neurological function in most patients.

Objective To investigate the bacterial resistance in nationwide and understand the distribution of bacterial and resistance trend.MethodsThe 6507 clinical isolates were collected from 19 hospitals in 17 cities.The susceptibility tests were performed using agar dilution method recommended by Clinical and Laboratory Standards Institute (CLSI) in central laboratory.The values of MIC50,MIC90 and MICrange were calculated by SPSS 17.0 and the susceptibilities of isolates to antimicrobial agents were determined by using CLSI (2010) guideline.Of all 6507 isolates,4691 strains were collected from target wards and 1816 were isolated from others wards.ResultsAmong 4691 strains,1156 were Gram-positive (24.6％ ) and 3535 were Gram-negative (75.4％).Based on the minimum inhibitory concentration results,the prevalence of methicillin resistant Stapylococcus aureus and methicillin resistant Stapylococcus epidermidis are 51.6％ ( 325/630 ) and 87.0％ ( 228/262 ) respectively.Staphylococci showing intermediate or full resistance to vancomycin were not observed. Coagulase negative Staphylococci showed 2.5％ (16/642)intermediate rate and 1.6％ ( 10/642 ) full resistance rate to teicoplanin,and showed 0.5％ ( 3/642 )resistance rate to linezolid.Antibiotic resistance rate of Enterococcus faecalis to ampicillin was 17.1％(19/111),while the resistance rate of Enterococcus faecium to ampicillin reached up to 85.0％(164/193).Three Enterococcus faecium were resistant to glycopeptides.The prevalence of penicillin resistance Streptococcus pneumoniae and penicillin intermediate Streptococcus pneumoniae were 41.2％ ( 145/352) and 37.2％ (131/352) respectively based on oral penicillin criterion,while the prevalence were 0.0％ (0/352) and 6.0％(21/352) based on vein to non-meningitis criterion.A vast majority of Enterobacteriaceae maintained high susceptibility to carbapenems,with resistance rate less than 2.0％.In addition,tigecycline,moxalactam,fosfomycin and amikacin displayed desirable antibacterial activity against Enterbacteriaceae,and resistance rates to these drugs were all less than 10.0％.For non-fermenting Gramnegative isolates,resistance rate of Pseudomonas aeruginosa and Acinetobacter baumannii to imipenem were 23.1％ ( 139/601 ) and 53.5％ (419/784) respectively.Resistance rate of Acinetobacter baumannii was much higher than that during the period 2007 - 2008.Colistin,tigecycline,minocycline and fosfomycin demonstrated good antibacterial activity against Acinetobacter baumannii in vitro.Conclusions Compared with MOHNARIN 2007 -2008year surveillance results, significant increase in resistance rate of Acinetobacter baumannii was demonstrated.Resistant strains to linezolid and tigecycline were found.Bacterial resistance has been a widespread problem in our country,which requires much more attention.

Objective To investigate the antimicrobial resistance in the A cinetobacter baumannii strains in different parts of China during 2012 .Methods A total of 8 739 clinical isolates of Acinetobacter were collected from 13 general hospitals and two children’s hospitals ,of which most were A . baumannii (89 .6% , 7 827/8 739 ) . Antimicrobial susceptibility testing was carried out by means of Kirby-Bauer method according to the unified protocol . The susceptibility testing data were analyzed by WHONET 5 .6 software according to CLSI 2013 breakpoints .Results Majority (85 .4% ) of the Acinetobacter strains were isolated from inpatients .The remaining 14 .6% were from outpatients and emergency room patients .Of the 7 827 strains of A .baumannii , 10 .9% ,35 .2% ,35 .7% and 43 .4% were resistant to tigecycline ,minocycline ,cefoperazone-sulbactam and amikacin , respectively .The percentage of A .baumannii resistant to imipenem and meropenem was 63 .5% and 68 .2% ,respectively . The antimicrobial resistant pattern varied in different hospitals . The resistance of A . baumannii varied between different clinical departments .A number of pandrug resistant (PDR) (20 .0% ,1 567/7 827) and multidrug-resistant (MDR) (45 .0% , 3 521/7 827 ) A . baumannii were identified . Conclusions A . baumannii is the most popular pathogenic bacteria among Acinetobacter .The antibiotic resistance of A .baumannii is still increasing .Cefoperazone-sulbactam and minocycline has good in vitro antibacterial activity against A .baumannii .The antibiotic resistance of A .baumannii varies greatly with hospital and department .

Objective To investigate the distribution and changing resistance proifle ofSalmonella isolates in hospitals across China during the period from January 2005 to December 2014.Methods Seventeen general hospitals and two children’s hospitals were involved in this program. Antimicrobial susceptibility testing was carried out by means of a unified protocol using Kirby-Bauer method or MIC determination. The results were analyzed according to CLSI 2014 breakpoints.Results The proportion ofSalmonella isolates increased with time from 0.2% in 2005 to 0.7% in 2014. A total of 3 478Salmonella strains were collected from 19 hospitals. The proportion ofSalmonella typhimurium andSalmonella enteritidis was 27.4% and 24.4%, respectively. During the 10-year period, theSalmonella strains showed highest resistance rate to ampicillin (33.3%-64.8%), but low resistance to cefoperazone-sulbactam (0-5.3%) and ciprofloxacin (2.4%-14.3%).S. typhimurium showed higher resistance rate thanS. typhi,S. paratyphi andS. enteritidis. About 76.8% and 50.5% ofS. typhimurium were resistant to ampicillin and trimethoprim-sulfamethoxazole. The average prevalence of multi-drug resistantSalmonellawas 3.9% in the ten-year period, the highest (7.5%) was in 2005, the lowest (1.5%) in 2013.Conclusions During the period from 2004 to 2015, majority of theSalmonella isolates in hospitals across China wasS. typhimurium andS. enteritidis. Ampicillin and trimethoprim-sulfamethoxazole are no longer appropriate for empirical treatment ofS. typhimurium infection due to high resistance rate.Salmonella isolates are relatively more susceptible to third-generation cephalosporins and quinolones. Ongoing monitoring is necessary to identify multi-drug resistant strains ofSalmonella.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.