Objective To construct a qseC-deleted mutant strain of E.coli by Red recombination and to study the effect of qseC gene on biofilm formation in the mutants.Methods The chloramphenicolresistant gene flanked by homologues of target genes was amplified by PCR and electro-transformed into E.coli MC1000.When induced by L-arabinose,the plasmid pKD46 could express three recombinant proteins of λ-prophage,which led to the replacement of target gene(qseC) with chloramphenicol-resistant gene.Then the chloramphenicol-resistant gene was eliminated by FLP-promoted recombination events.The biofilm formation of wild-type and mutant strain was detected by crystal violet staining.Results The qseC-deleted mutant of E.coli was confirmed by various PCR and DNA sequencing.Gene qseC was completely deleted.There was no significant difference in growth ability between the qseC mutant strain and the wild-type strain MC1000.The biofilm formation of wild-type and mutant strain was quantified by crystal violet staining.The absorbance determined with a plate reader at 570 nm was 1.00±0.15 and 0.47±0.10 respectively.Conclusion The qseC-deleted mutant of E.coli was constructed successfully.And the qseC gene plays an important role in regulation of biofilm formation in E.coli.

Objective To summarize our experience in the prevention and treatment of iatrogenic vascular(trauma).Methods The clinical data of 24 different types of iatrogenic vascular trauma committed from 2003 to 2006 were retrospectively analyzed.Results The 24 cases included 7 cases of superior mesenteric(arteriovenous) trauma,3 cases of portal venous trauma,4 cases of carotid arterial trauma,6 cases of iliac and femoral arterial trauma,and each one of trauma of popliteal artery,axillary artery,renal artery,left gastric artery,respectively.Treated method: Six cases underwent vascular repair,5 cases had vascular anastomosis,2 cases had vascular replacement,3 cases had vascular ligation,2 cases had covered stent implantation under intervention,and other methods included thrombectomy,thrombolysis and packing.Among the 24 cases,22 were cured completely,one patient died from massive hemorrhage 24 hours after operation,and the other died 5 days after operation.Conclusions Iatrogenic vascular trauma can be prevented and its incidence reduced by increased vigilance,clear identification of the anatomy,and accurate and careful operation.Once iatrogenic vascular trauma has occurred,its cause must be determined and then different treatment methods can be(chosen),based on the cicumstaces. When effective treatment technique is not at hand,one should promptly seek outside support or transfer the patient to an advanced hostipal.

MicroRNAisatypeofsingle-strandednon-codingRNA,directlybondingtothecomplemen-tary target gene mRNA.That leads to the inhibition of mRNA translation of the target molecule in order to reduce expression of the target gene.MicroRNAs are not only involved in the regulation of inflammatory reac-tion,but also play important roles in the formation of neoplasm.The researches showing that the inflammatory reaction interacting with miRNAs results in the differential expressions of microRNAs in lung cancer have been widespreadly concerned.Along with the deepening of the research on the mechanisms of inflammatory reaction and differential expression of microRNAs,it will provide new strategies for the prevention,diagnosis and treat-ment of lung cancer.

Three hundred and nine community health service (CHS) practitioners were selected with randomized cluster sampling for survey with the job satisfaction questionnaire-occupational stress indicator (OSI).Degree of the job satisfaction was (68 ± 12)%.Position, work experience, income,feeling of recognition, degree of motivation, the scope for career development, the space for personal ambition and the relationship between salary and work load were potential influencing factors of job satisfaction to CHS practitioners.The authors suggest to establish the dynamic mechanisms of satisfaction study and to formulate comprehensive and effective incentive measures for CHS practitioners.

Objective To discuss how to practise and consummate to shoot and assess the portfilm for radiotherapy. Methods Double radiography technique was used to take a portfilm. The reference mark points (plumbum points) were added into the field at the first exposure and the cross lines drawn based on the plumbum point images were definited as the reference coordinate to the actual field. Then, the portfilm was compared and analyzed with the simulator planning film. Results The images of both plumbum points and block boundaries were distinct in the portfilm, but the resolution and contrast of the tissue structure image was inferior to the ordinary film from simulator. However, all different structures and positions could be identified in order to assess if the actual field coincided with the radiation planning. Conclusions Although the real-time property of the portfilm is inferior to the electric portal image device (EPID), the double radiography portfilm is feasible as an important quality control method in radiation therapy due to its lower price and easier performance. The design of reference points is the key point in this technique.

Objective To explore the clinical characteristics of and to provide help to the prevention and treatment of malignant chest tumor with nosocomial mixed fungal-bacterial infection.Methods From July 2007 to June 2015,pathogenic bacteria in sputum,blood,urine,chest incision,thoracic and abdominal fluid,and implantable medical biological material were cultivated in 5067 patients with malignant chest tumor suspected with infection.The clinical characteristics,source of specimen and pathogenic bacteria,the types of diseases,medical intervention activities of 142 cases detected with mixed fungal-bacterial infection were retrospectively analyzed.Fesult In 142 patients,104 patients at clinical stage Ⅲ-Ⅳ accounted for 73.2％,and 94 patients used antibiotics more than 14 days (66.2％);104 cases had implanted biological materials (74.7％);96 cases died (67.6％).A total of 167 strains bacteria were isolated.Sixty-one strains of G+ bacteria accounting for 36.5％ were mainly Epidermis staphylococcus and Staphylococcus aureus;106 strains of G-bacteria accounting for 63.5％ were mainly klebsiella pneumonia,Escherichia coli and baumanii;172 strains fungus mainly of Candida albicans were isolated (77.3％).Pathogenic bacteria sources were mainly sputum specimens + pharynx strip,blood culture and medical implant materials.In 72 lung cancer patients,squamous carcinoma and small cell carcinoma were 52.8％ and 33.3％ respectively,higher than adenocarcinoma (12.5％);In 42 esophageal cancer patients,postoperative patients were 42.9％.Parenteral nutrition patients with more than 10 days were 80.9％ higher than that of parenteral nutrition in patients with less than 10 days (19.1％).Conclusion Among malignant chest tumor patients with nosocomial mixed fungal-bacterial infection,the bacteria were found in staphylococcus aureus,klebsiella pneumoniae and E.coli and the fungus was Candida albicans.For clinical stage Ⅲ-Ⅳ,patients with parenteral nutrition for more than 10 days,having history of chemo or radiotherapy,with antimicrobial use for more than 14 days,and with implanted biological materials,should be warned about nosocomial mixed fungal-bacterial infection.

BACKGROUND:Studies have demonstrated that prosthetic valve endocarditis is primarily caused by bacteria adhering on the surface of the materials.Thus,the relationship of prosthetic valve materials with bacteria adhesion and growth is an important subject.OBJECTIVE:To explore the influence of prosthetic valve materials on bacteria growth through observing the relationship of bacteria adhesion on prosthetic valve materials and bacteria growth.DESIGN,TIME AND SETTING:Repetitive measurement was performed at the Department of Cardiac and Thoracic Surgery,Third Hospital of Kunming Medical College from January to March 2001.MATERIALS:Terylene(Dacron)was purchased from Man-made Blood Vessel Laboratory of Suzhou Weaves Belt Factory;polytetrafluoroethylene was provided by Teflon-GoreTexW.L.Gore & Associates,Inc.Arizona,USA;pyrolytic carbon was provided by Department of Biological Material of Sichuan Union University;staphylococcus anreus,Escherichia coli,staphylococcus epidermidis,and Pseudomonas aerugmosa were prepared by our laboratory.METHODS:The growth curve of staphylococcus aureus,staphylococcus epidermidis,Escherichia coli and Pseudomonas aeruginosa on dacron,pyrolytic carbon and pelytetrafluoroethylene were quantitatively determined respectively by plate counting and gamma.ray counting of 125 Ⅰ radiolabeled bacteria in vitro.Bacteria growing normally served as control.All bacteria were cultured for 30 hours,and bacteria concentration was determined every 2 hours.In addition,the adhesive capacities of foMr kinds of bacteria on dacron,pyrolytic carbon and polytetrafluoroethylene were detected Escherichia coli and Pseudomonas aeruginosa on dacron,pyrolytic carbon and polytetrafluoroethytene.RESULTS:There were no significant differences in adhesive capacities of each bacterium on dacron,pyrolytic carbon and polytetrafluoroethylene at the same time point(P>0.05).The differences in growth curve of four kinds of bacteria on prosthetic valve materials were not remarkable compared to the control(P>0.05).Different bacteria showed different adhesion degree on the materials:staphylococcus aureus exhibited strongest adhesion on dacron;staphylococcus epidermidis on pyrolytic carbon;Escherichia coli on dacron.The adhesive capacity of Pseudomonas aerugmosa on dacron reached peak within 12 hours,and gradually decreased,but maintained strong adhesion on the other materials.The adhesive capacmes of four bacteria on the materials did not increase or maintain with time.CONCLUSION:The adhesive capacity of one bacterium to different artificial valve materials and different bacteria to one prosthetic valve materials is different.The materials.show little influence on bacterium growth cycle.

Objective To study the effect of epinephrine on biofilm formation of the qseC-deleted mutant of Escherichia coli on biomaterial.Methods The strains used in this study are Escherichia coli MC1000 and MC1000AqseC.LB was used for all the experiments.To determine the effect of epinephrine on motility,halos were measured in LB medium at 37℃ in the presence of epinephrine(50 μmol/L).LB with epinephrine and without epinephrine were used,and then the experiment of bacterial biofilm formation on PVC material was taken.The relative amount of biofilm was estimated.The thickness of bacterial community and bacterial community quantity in the unit area on PVC materials were measured by confocal laser scanning microscope( CLSM),and the surface structure of biofilm formation was observed by scanning electron microscope(SEM).Results The mutant strain formed less biofilm than the wild-type strain in LB.The increment in motility of wild-type strain due to epinephrine addition was shown,but mutant strain is unaffected.Similarly,biofilm formation of the wild-type strain was increased by epinephrine,but epinephrine did not affect the biofilm formation of the qseC mutant.The CLSM and SEM showed that epinephrine stimulated biofilm formation of wild-type strain on PVC materials,but had no effect on qseC-deleted mutant strain.Conclusion Epinephrine increases Escherichia coli biofilms on biomaterials through qseC.

Objective To investigate the role of quorum sensing Escherichia coli regulator C (qseC) in intestinal bacterial translocation in rats subjected to hemorrhagic shock.Methods Thirty Sprague-Dawley rats,weighing 250-300 g,were randomly divided into 5 groups (n =6 each):control group (group C),MC1000-sham shock group (group M-SS),MC1000qseC-sham shock group (group △-SS),MC1000-hemorrhagic shock group (group M-HS),and MC1000△ qseC-hemorrhagic shock group (group △-HS).The rats drank 150 μg/ml of disinfect water containing streptomycin in 3 consecutive days to inhibit the autochthonous flora in the intestinal tract.From 4th day,the rats were fed with Escherichia Coli MC1000 or MC1000△ qseC 1 ml/100 g by gastric perfusion once a day for another 3 consecutive days in the other 4 groups,while the rats were fed with normal saline instead in group C.Hemorrhagic shock was induced by blood-letting.The mesenteric lymph node (MLN),spleen and liver specimens were obtained at 24 h after operation for bacterial culture and the bacteria were identified.Bacterial translocation from gut to MLN,spleen and liver was observed and the number of bacteria in MLN,spleen and liver tissues were counted.Results The rate of bacterial translocation was significantly higher,and the number of bacterial colonies in MLN,spleen and liver tissues and the total number of bacterial colonies were significantly larger in groups M-HS and △-HS than in group C,and in group M-HS than in groups M-SS and △-SS (P ＜ 0.05).The rate of bacterial translocation was significantly lower,and the number of bacterial colonies in MLN,spleen and liver tissues and the total number of bacterial colonies were significantly smaller in group △-HS than in group MHS.Conclusion QseC is involved in the intestinal bacterial translocation following hemorrhagic shock in rats.

Objective To evaluate the relationship between quartz's deposit and expression of NF-κB in non-small cell lung cancer (NSCLC) lung tissues in Xuanwei, Yunnan Province, and to clarify the role of quartz in Xuanwei NSCLC's carcinogenic mechanism. Methods As research objects, the lung tissues of NSCLC and lung benign lesions after surgical resection were collected from July 2009 to September 2015 at the Third Affiliated Hospital of Kunming Medical University. Firstly, the transmission electron microscopic (TEM) with energy dispersive X-ray analyzer (EDS) was used for observation of crystalline deposit and local pathological changes. Secondly, expression level of NF-κB had been analysed and a correlation analysis with particle size of SiO2 crystal in the same lung sample was made. Results The occurrence rates of quartz in Xuanwei NSCLC lung tissues were above non-Xuanwei NSCLC and benign lung tissues (P<0.01);the average particle size of SiO2 crystal was (226 ± 120) nm × (237 ± 163) nm in Xuanwei NSCLC group and it was smaller than the other two groups; In Xuanwei NSCLC group, the expression level of NF-κB was significantly higher than non-Xuanwei and benign lung tissues (P< 0.01), but there was no significant difference between cancer tissues and normal lung tissues in the group (P>0.05). The expression level of NF-κB was generally increasing when quartz 's size became smaller. Conclusion Quartz 's deposit may play a certain role in carcinogenic mechanism of lung cancer in Xuanwei, the smaller the particle size, the greater the cytotoxicity.