Objective To study the mutations of Pseudomonas aeruginosa oprD gene in Imipenem-resistant clinical isolates. Methods Random amplified polymorphic DNA typing(RAPD) was carried out to analyse the homology in 10 Imipenem-resistant clinical isolates. Pseudomonas aeruginosa oprD gene in 10 Imipenem-resistant clinical isolates were amplified by polymerase chain reaction and sequenced. Results Ten Imipenem-resistant clinical isolates were divided into four different clones which can not produce metallo ?-lactamase. As compared with sequence X63152, oprD gene of Pseudomonas aeruginosa varied greatly. The aberration rates exceed 50%. There were multiple point mutations within 276～387 bp coding region of 30, 11, 9, 20, 31 strains. Due to the mutations of 308 bp G→C and 344 bp C→A, threonine and diaminocaproic acid were replaced by serine and threonine respectively. The DNA deletion of 393～412 bp in oprD gene contributes to the frame shift mutation in the following nucleotide sequence. The deletion of 264～273 bp in the coding region of oprD gene in 13 and 21 clone strains leads to frame shift mutations forming terminal codon TAA(319～321 bp).Base substitutions and multiple point mutations were obvious in the coding regions of 1 and 22 clone strains. Their aberration rates were 54.03% and 74.89% respectively. Conclusions The mutations of Pseudomonas aeruginosa oprD gene in Imipenem-resistant clinical isolates are various.

One of the major responsibilities for medical students is to save lives and to popularize emergency medical treatment knowledge for the masses of society.Based on research analysis,systemic training of cardiopulmonary resuscitation program including lectures,simulation education and social practice were performed for medical students.After practice activities,these students could proficiently apply the basic knowledge and skills of cardiopulmonary resuscitation in practical work and spread what they have learned to the public.Furthermore the program could improve students' abilities in social practice and team spirit and it is of great social significance.

Objective:To investigate the correlation between lumbar bone mineral density (BMD), musculoskeletal perfusion andmuscle mass.Methods:From May 2019 to August 2020, totally 91 patients who applied for CT perfusion (CTP) examination of abdomen (the scan range included the vertebral body of L1－L3) in Shanghai Tenth People′s Hospital of Tongji University were retrospectively analyzed. The mean BMD of L1－L3 vertebral body was measured by quantitative CT (QCT) at the same time of CT plain scan. According to BMD, the subjects were divided into normal BMD group ( n=33), osteopenia group ( n=41) and osteoporosis (OP) group ( n=17). The L3 level perivertebral muscle mass index and fat fraction were calculated based on QCT examination. The lumbar vertebral and perivertebral muscle perfusion parameters were measured based on CTP images. The parameters of QCT and CTP among three groups were analyzed by Kruskal-Wallis H test or one-way ANOVA. The correlation analysis was conducted between these parameters using Pearson or Spearman analysis. Results:The differences of the perivertebral muscle mass index and fat fraction among three groups were statistically significant ( P<0.05). The differences of the lumbar vertebral perfusion parameters including blood flow (BF), blood volume (BV) and flow extraction product (FE) among three groups were statistically significant ( P<0.05), and BF, BV and FE were positively correlated with BMD ( r=0.444, 0.312 and 0.266 respectively, all P<0.05; adjusted for age and gender r=0.437, 0.340 and 0.337 respectively, all P<0.05). There was no statistically significant difference in perivertebral muscle perfusion parameters among three groups ( P>0.05). Perivertebral muscle mass index was negatively correlated with fat fraction ( r=-0.599, P<0.001; adjusted for age and gender r=-0.404, P<0.001), and there was no correlation between perivertebral muscle mass index and muscle perfusion parameters, as well as perivertebral muscle fat fraction and muscle perfusion parameters. Conclusions:With the changes of BMD, bone mass and perivertebral muscle mass at L3 level are synchronous. Decreased vertebral bone mass is accompanied with reduced perivertebral muscle mass, increased muscle fat and decreased bone perfusion. The changes of vertebral perfusion and perivertebral muscle perfusion at L3 level are asynchronous, which implies that reduced perfusion in OP patients may be confined to the bone.

Objective To investigate the construction of Streptococcus mutans luxS gene knockout mutant which can act as the technical platform for following researches on luxS quorum sensing function in oral ecosystem.Methods Erythromycin resistance gene was inserted between two 1 kb fragments containing regions of DNA immediately upstream and downstream of the luxS translational start and stop codons.The resuhing construct was linearized and electro-transformed into Streptococcus mutans cells.After allelic exchange,the luxS gene knockout mutant strains were selected on 10μg/ml erythromycin plates,and compared the growth and biofilms formation of luxS knockout mutant with wild type strains.Results The luxSknockout mutant was confirmed by PCR,and it was also confirmed that this gene mutant could be stably passed through in vitro.The growth mode of luxS knockout mutant showed obvious difierences against that of wild type at stationary phase,the knockout mutant gained more bacteria cells growth.Conclusion Streptococcus mutans luxS gene has been successfully disrupted with allelic exchange.This mutant strains showed higher growth abilitv which could be the consequence of quorum sensing mutant.

Objective To investigate the efifcacy and adverse effect of ultrasound-guided injection of different dosage of thrombin in the treatment of femoral artery pseudoaneurysm formed after vascular intervention. Methods 48 cases of femoral artery pseudoaneurysm after vascular interventional operation in our hospital were randomly divided into two groups according to the dosage thrombin given.Under ultrasound guidance, patients in the observation group (n=24) received injection thrombin 100U/ml while patients in the control group received injection of thrombin 500U/ml.All the operational procedures were identical between the 2 groups. Results No statistical differences were found in clinical characteristics, total number injection needed and operation time between two groups.Recurrence pseudoaneurysm was noted in 1 cases in the observation group. 2 cases of superifcial femoral arteries thrombin and 1 case of fever were recorded in control group. There was no difference in adverse event rates between the 2 group. Conclusions Ultrasound-guided injection with low dose thrombin in the treatment of post interventional femoral artery pseudoaneurysm is equally effective as higher dose.

OBJECTIVE To study the antimicrobial susceptibility and molecular epidemiology of imipenem-resistant Pseudomonas aeruginosa isolated from patients in burn wards in a hospital of Guangzhou. METHODS A total of 48 imipenem-resistant isolates were collected,antimicrobial susceptibility was tested by KirbyBauer disk diffusion method.Random amplified polymorphic DNA(RAPD) typing was carried out to analyze the homology. RESULTS All isolates were multiresistant,the orders of sensitivity rates of antibiotics were CIP,TOB,AMK,GEN,and FEP.Forty eight strains were classified into types A,B,C,and D based on RAPD pattern,types A and B were the most epidemic clones. CONCLUSIONS The prevalence of imipenemresistant P.aeruginosa in burn wards of the hospital is due to nosocomial infection.The prevalent strains are multiresistant.

OBJECTIVE To analyze homology,antimicrobial susceptibility and metallo-?-lactamase gene type of metallo-?lactamase producing Pseudomonas aeruginosa in burn wards.METHODS Antimicrobial susceptibility tests were performed with E-tests.Using 2-mercaptoethanol disc synergy test to screen metallo-?-lactamase(positive) strains from imipenem-resistant P.aeruginosa in burn wards.Metallo-?-lactamase gene and integrase gene were amplified and sequenced.Resistance plasmid transfer and curing experiments were implemented to study the transfer of imipenem resistance and plasmid DNA was extracted and purified with Qiagen Plasmid Mini Kit.Random amplified polymorphic DNA(RAPD) typing was carried out to analyze the homology of the isolates.(RESULTS) Six strains of P.aeruginosa were suggested to produce metallo-?-(lactamase) by 2(-mercaptoethanol) disc synergy test.Using primers described for bla(VIM),the amplifications were observed among all 6 isolates and a VIM-2 metallo-?-(lactamase) gene was identified by sequencing.All isolates which producing VIM-2 metallo-?-(lactamase) had class 1 integrase gene and derived from a same clonal origin.CONCLUSIONS(VIM-2) metallo-?-(lactamase) producing P.aeruginosa is prevalent in burn wards,all isolates which producing VIM-2 metallo-?-(lactamase) have class 1 integrase gene.

Objective:To establish the technique for real-time fluorescence quantitative reverse transcription polymerase chain reaction(FQ-PCR)by DNA melting curve analysis for detecting the CDR3 shewing of TCR alpha gene repertoire in human peripheral blood.Methods:Total RNA of peripheral blood mononuclear cell(PBMC)from 4 healthy donors and 2 patients with lymphomatous leukemia were transcripted reversely into cDNA.The cDNA of 32 TRAV gene family CDR3 was amplified by FQ-PCR.Analysis of the monoclonal/oligoclonal/polyclonal CDR3 spectratyping with DNA melting curve.Results:The FQ-PCR products of 32 TRAV family CDR3 were showedas a blur land at the predicted of products size in healthy donors and parts of TRAV family CDR3 products disappeared in patients on 1.5% agarose gel by Gold-View staining.The 32 TRAV family CDR3 were showed with different frequencies by relative fluorescence quantitative in healthy donors and the patients.The CDR3 spetratyping for 32 TRAV families was showed as polyclonal peak(Gaussian distribution)in healthy donors but showed as different monoclonal/oligoclonal/polyclonal peak in the patients with lymphomatous leukemia with DNA melting curve analysis(we called "melting curve spectratyping of CDR3")Conclusion:The study suggests that the technique of "FQ-PCR with DNA melting curve analysis be convenience and celerity for detecting the CDR3 skewing of TCR alpha gene repertoire in human peripheral blood.

OBJECTIVE:To study the pharmacokinetics of the active ingredients of Shenmai injection,including ginsenoside Rg1 and ginsenoside Re,in normal Beagle dogs and those with myocardial ischemia. METHODS:6 Beagle dogs were given isopro-terenol hydrochloride (1.1 mg/kg) sc to establish the model of myocardial ischemia (model group). Another 6 Beagle dogs were given isometric normal saline (2.2 ml/kg) sc as controls group. The two groups of dogs respectively received corresponding drugs sc at 8:00 am and 13:00 pm on day 1 and at 8:00 am on day 2. Each group of dogs were given Shenmai injection(1.6 ml/kg)iv 1 h after administration on day 2,and such intravenous drip lasted for about 1 h. Blood was collected from each group 0,0.25, 0.5,0.75,1(the end of iv),1.5,2,3,4,6,8,12 and 24 h from the start of iv. Liquid chromatography-mass spectrometry was adopted to determine the concentrations of ginsenoside Rg1 and ginsenoside Re in blood,and WinNonlin 6.3 was used to calculate pharmacokinetic parameters for comparison. RESULTS:For ginsenoside Re in the dogs of the model group,t1/2 was(2.69±1.12) h,AUC0-24 h was(2 060.78±812.18)h·μg/L,Vz was(46.16±20.98)ml and CL was(9.02±4.45)ml/h;compared to the normal control group,AUC0-24 h was much greater and Vz and CL were significantly lower,showing a statistically significant difference(P<0.05). No significant difference in the pharmacokinetic parameters of ginsenoside Rg1 was shown between 2 groups(P>0.05). CON-CLUSIONS:Myocardial ischemia may affect the removal of ginsenoside Re in Beagle dogs,but has no effect on the pharmacoki-netic process of ginsenoside Rg1.

Objective To study the risk factors in patients with trauma accompanied by multiple organ dysfunction syndrome.Method The data of 107 patients with trauma in ICU,Tongji Hospital,Tongji Medical College,Huazhong University of Science and Technology,were retrospectively studied.All patients were divided into 2 groups:MODS group and non-MODS group.The clinical and laboratory,results,ISS score,APACHEⅢscore and GCS score were studied.Results There were no differences on gender,age and mobility of shock between the two groups.There were significant differences on the treatment of shock,ISS score,APACHEⅢscore,CCS score,the levels of blood sugar and platelet between two groups.The Logistic regression analysis showed the main risk factors were treatment of shock,ISS score and APACHEⅢscore.Conclusions The risk factors in patients with trauma accompanied by multiple organ dysfunction syndrome were the treatment of shock, ISS score and APACHEⅢscore.