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 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 investigate the distribution of water fluoride and the status of water-improving defluoridation projects,thus to explore the condition of endemic fluorosis in Guangxi Province.Methods According to"The National Technical Scheme for Endemic Disease Contml in 2005",the fuorine content in water Was determined by F-ion selective electrode,children's dental fluorosis was checked by Dean method.and the skeletal fluorosis was checked by the standard of clinical scale of skeletal fluorosis.Results 305 water samples in 61 villages were examined,among which 71 waters were exceeded the standard,accounting for 23.28%(71/305).The projects of defluoriding drinking water were running well except one was discarded.The prevalence of dental fluorosis was 13.55%(356/2627),the prevalence of skeletal fluorosis was 4.02%(65/1615).Conclusions The situation of endemic fluorosis control is not optimistic in Guangxi,which needs fuaher prevention and controls.

Objective:To explore the clinical characteristics of various types of severe drug eruption and common sensitized drugs,and to provide clinical references for reducing the incidence of severe drug eruption.Methods:The clinical data regarding 126 cases of severe drug eruption were analyzed retrospectively from June 2009 to May 2017 in Xiangya Hospital,Central South University.Results:In the 126 cases of severe drug eruption,the distribution of men and women ratio was 1∶1.38.The length of stay was (12.7±9.8) d.The most common type was Steven-Johnson syndrome;the most dangerous type was drug-induced bullosa epidermolysis,The most common sensitized drug category in these patients was antibiotics;the most common single sensitizing drug was carbamazepine,following by allopurinol.Conclusion:Severe drug eruption occurs mostly in young and middle-aged people.Steven-Johnson syndrome is the most common type;drug hypersensitive syndrome has the longest length of hospital course.Mortality rate of drug-induced bullosa epidermolysis is the highest.Timely stop using of allergens,early using glucocorticoids,and timely combination of non-glucocorticoids treatment (such as intravenous immunogloblin,plasma exchange and hemodialysis),can improve the efficacy and reduce the complications and mortality.