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 study indole alkaloids of Ervatamia hainanensis. Methods The compounds were separated and purified by column chromatography with silica gel and Sephadex LH-20. The structures were identified by IR, MS, and NMR. Results Seven alkaloids were identified as: hainanervatasine (Ⅰ), hainanervatacine (Ⅱ), vobasine (Ⅲ), coronaridine (Ⅳ), 3-hydroxyl coronaridine (Ⅴ), 3-(2-oxopropyl) coronaridine (Ⅵ), and tabernamine (Ⅶ), respectively. Conclusion Compounds Ⅰ and Ⅱ are new compounds. Compounds Ⅳ and Ⅵ are isolated from this plant for the first time.

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.

BACKGROUND: Permanent or transient implantation of biomaterials can result in biomaterials-centered infections (BCI) in lung cancer patients.OBJECTIVE: To investigate the relationship between BCI and peripheral blood transforming growth factor β1 (TGF-β1) in patients with lung cancer.METHODS: A total of 248 lung cancer patients undergoing in vivo intravascular catheter indwelling > 7 days were included.Quantitative method was used for intubation, bacteriological culture and paired blood culture, and API Staph strips were adopted for positive patients. While enzyme-linked immunosorbent assay was used to detect TGF-β1 levels in the peripheral blood of patients with lung cancer and 75 healthy volunteers as normal controls.RESULTS AND CONCLUSION: Among the 248 patients, there were 82 BCI-positive cases, and 166 BCI-negative cases.Thirteen patients were confirmed to have catheter-related bloodstream infection. There were 48 Gram-positive bacteria, 24Gram-negative bacilli, and 10 fungal. The levels of TGF-β1 were higher in BCI-positive patients than BCI-negative patients (P < 0.05); the levels of TGF-β1 in the BCI-negative group were higher than those in the normal control group (P < 0.05). For lung cancer patients with nosocomial infection induced BCI, there are various species of pathogenic bacteria, and Gram-positive bacteria are more common. To detect TGF-β1 levels in patients with lung cancer is of significance for early prevention of BCI.

BACKGROUND: High-concentration glucose can induce the formation of biofilms in Staphylococcus epidermidis.OBJECTIVE: To investigate the effect of high-concentration glucose on eliminating ability and adhesion of Staphylococcus epidermidis in Tupaia belangeri.METHODS: Tupaia belangeri models of hyperglycaemia (≥11.1 mmoL/L) were induced by intraperitoneal injection of Streptozocin. PVC catheters were inserted into the left femoral vein, and Staphylococcus epidermidis with or without formation of biofilms was inoculated into the catheters.RESULTS AND CONCLUSION: Following transfection of Staphylococcus epidermidis with formation of biofilms, there were higher rates of bacterial infection as well as higher bacterium colony number in the serum, heart, liver, kidney and pancreas of Tupai belangeri in hyperglycemia group (≥11.1 mmoL/L) as compared with the control group (P < 0.05). Detected by scanning electronic microscope, biofilm formation was remarkable in hyperglycemia group (≥11.1 mmoL/L) (P < 0.05). However, there was no formation of biofilms in hyperglycemia or control groups following transfection of Staphylococcus epidermidis without formation of biofilms. Hyperglycemia can induce the decreasing ability of eliminating bacteria and the increasing formation of biofilms on the surface of biomaterials transfected with Staphylococcus epidermidis.

(P < 0.05 ).Scanning electron microscopy showed that the three-dimensional structure of mix-biofilm in control group was more complex.As real-time PCR showed,after 6-hour culture,the expressions of icaA,fbe,aap,hwp1, als3 and efg1 genes in Farnesol group were down-regulated compared to those in control group and after 24-hour culture the expressions of aap,hwp1,als3 and efg1 genes in Farnesol group were down-regulated compared to those in control group.Conclusion With the intervention by fungal quorum sensing molecules Farnesol,the structure in control group became denser and more complex than that in Farnesol group.This change may have a closer correlation with the down-regulated expressions of als3,hwp1 and efg1 genes,which are related to the formation of Candida albicans biofilms.

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.

Objective To explore the significance and curative effects of intrapericardial pneumonectomy and atria part resection in lung cancer operation.Methods Fifty eight patients of lung cancer were performed with intrapericardial pneumonectomy and atria part resection.Results The operative mortality rate was 0.The incidence rate of complications in post-operation was 36.21%,a majority of which was arrhythmia and occupied 18.97%.Conclusion The application of intrapericardial pneumonectomy and atria part resection in lung cancer operation can not only improve the resection rate but also can offer the opportunity of absolute resection and further therapy in a part of lung cancer patients.