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 compare the difference in pharmacokinetics characteristics of vancomycin in cerebrospinal fluid between administration by continuous infusion and interim infusion.Methods Twenty postoperative patients in the Department of Neurosurgery of Beijing Tiantan Hospital, Capital Medical University admitted into intensive care unit (ICU) to receive vancomycin for prophylaxis of intracranial infection were enrolled, and they were randomly distributed to a continuous intravenous infusion group and a interim intravenous infusion group, each group 10 cases. In continuous intravenous infusion group, the patients received a loading dose of vancomycin (15 mg/kg) by continuous intravenous pump infusion for 1 - 2 hours followed by 30 mg/kg vancomycin in a constant pump infusion rate for 24 hours; while in interim intravenous infusion group, the patients received 15 mg/kg vancomycin administered by intravenous pump infusion for 1 - 2 hours, once every 12 hours. The concentration of vancomycin in the cerebrospinal fluid at different time points was measured by two-dimensional liquid chromatography (2D-LC) method, the parameters of pharmacokinetics were calculated in the two groups, and the adverse reaction was observed.Results The comparison between the ratio of areas under the concentration-time curves (AUC) and minimum inhibitory concentration (MIC) of the continuous and interim groups showed no significant difference (19.7±14.0 vs. 16.1±6.4,P > 0.05). However, in the continuous intravenous infusion group, the drug concentration reached the peak value (0.96± 0.77)μg/mL at 12 hours, and later revealed a plateau concentration 0.91-0.93μg/mL for 12 hours; while in the intravenous infusion interim group, the drug concentration reached the peak value (0.92±0.47)μg/mL at 16 hours, in the later 2 hours declined to (0.84±0.45)μg/mL, and afterwards still had a tendency of persistent declination. In all the patients, no any adverse reaction related to the drug occurred.Conclusion Continuous intravenous infusion and interim intravenous infusion of vancomycin for the postoperative neurosurgical patients without intracranial infection have the similar efficacy of medication, but the former can achieve the peak concentration faster and later the fluctuation of drug concentration in cerebrospinal fluid is smaller than those in the latter.

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.

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.

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.

Objective To investigate the serum levels change of vascular endothelial growth factor (VEGF) during operation of non-small-cell lung cancer (NSCLC). Methods 120 cases of NSCLC patient diagnosed by pathology as well as with operation indication were selected as the experimental group. The patients selected were required without any chemotherapy or radiotherapy before operation, besides that, they should have good compliance and free will to be examined. During the process of experiment, 60 cases concluded as healthy in the physical examination were chosen as control group. The correlative information of the experimental group were collected including periphery blood specimen collected in 3 days before the operation, and of the 1st day, 7th day and 30th day after the operation while the periphery blood specimen of control group were collected. The serum levels of VEGF were detected by adopting enzyme linked immunosorbent assay (ELISA) method. Results The serum levels of VEGF in NSCLC patients before operation, of the first postoperative day, of the seventh postoperative day and of the thirtieth postoperative day were significantly higher than that in healthy people (P＜0.01), respectively (279.14±44.89)μg/L, (282.70±42.74) μg/L, (353.79±44.55) μg/L, (178.40±43.43) μg/L and (91.40±16.55) μg/L. The serum levels of VEGF in NSCLC patients showed positive correlation with the stages (P＜0.01). Conclusion The serum levels of VEGF in NSCLC patients scale up. At the same time it shows positive correlation with the stages of the primary tumor. The serum levels of VEGF in NSCLC patients scales up by degrees in one week after the operation, and drop one month later.

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 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.

Five general practitioners were trained for application of the enhancing CalgaryCambridge guide in consultation.The consultation time in 50 patients were recorded before and after training and the satisfaction degree of patients was investigated by questionnaire survey.Results showed that the length of consultation time after training was longer than that before training (490 s vs 277 s,P ＜ 0.05) and also longer than that of specialists (490 s vs 268 s,P ＜0.05).The overall satisfaction rate of patients was increased after training (72％ vs 88％,P ＜0.05).The results indicate that training of Calgary-Cambridge guide for doctor-patient communication can improve the communication skills of general practitioners.