In order to establish a method for the detection of serum antibodies to donkey-derived e-quine coronavirus(ECoV),recombinant ECoV N protein was expressed in E.coli system,purified by nickel column affinity chromatography and identified by Western blot.After optimizing the re-action conditions,the indirect ELISA(iELISA)detection method was established using the puri-fied recombinant protein as coating antigen and used to detect 143 clinical serum samples.The re-sults showed that the recombinant N protein,which has good reaction activity with serum antibod-y,was successfully expressed.The optimum conditions of the established iELISA method were as follows:the amount of antigen coated was 0.2 μg/well and overnight at 4 ℃,10％skimmed milk powder solution was sealed at 37℃ for 1.5 h,the dilution concentration of serum was 1∶200,and the enzyme-labeled secondary antibody diluted at 1∶10 000.The sensitivity test results showed that the positive serum could be diluted to 1∶6 400.The specificity test results showed that all an-tibodies to several donkey pathogens were negative.The repetitive test results showed that the in-tra-and inter-batch coefficients of variation were 2.90％-6.12％and 2.29％-7.88％respectively.The positive rate of clinical donkey serum was 57.3％.The iELISA established in this study pro-vides a technical support for epidemiological investigation and antibody surveillance.

In order to establish a method for the detection of serum antibodies to donkey-derived e-quine coronavirus(ECoV),recombinant ECoV N protein was expressed in E.coli system,purified by nickel column affinity chromatography and identified by Western blot.After optimizing the re-action conditions,the indirect ELISA(iELISA)detection method was established using the puri-fied recombinant protein as coating antigen and used to detect 143 clinical serum samples.The re-sults showed that the recombinant N protein,which has good reaction activity with serum antibod-y,was successfully expressed.The optimum conditions of the established iELISA method were as follows:the amount of antigen coated was 0.2 μg/well and overnight at 4 ℃,10％skimmed milk powder solution was sealed at 37℃ for 1.5 h,the dilution concentration of serum was 1∶200,and the enzyme-labeled secondary antibody diluted at 1∶10 000.The sensitivity test results showed that the positive serum could be diluted to 1∶6 400.The specificity test results showed that all an-tibodies to several donkey pathogens were negative.The repetitive test results showed that the in-tra-and inter-batch coefficients of variation were 2.90％-6.12％and 2.29％-7.88％respectively.The positive rate of clinical donkey serum was 57.3％.The iELISA established in this study pro-vides a technical support for epidemiological investigation and antibody surveillance.

Objective To construct hns gene overexpression strains of Burkholderia thailandensis BPM,and explore the effects of hns overexpression on bacterial growth,motility,biofilm formation ability and susceptibility to antimicrobial drugs.Methods The hns genes 03253 and 05307 were respectively cloned into the expression vector pTAC-Cm to yield recombinant vectors pTAC-03253 and pTAC-05307.Then the 2 types of plasmids were electroporated into the BPM competent strain to obtain recombinant strains,and their phenotypic changes in growth,motility,biofilm,and drug sensitivity were detected.Results The strains of hns overexpression were successful constructed,and they presented significantly inhibited growth and motility,markedly enhanced ability to form biofilms,decreased sensitivity to levofloxacin and minocycline when compared with the wild-type BPM strain.Conclusion H-NS protein plays an important role in the regulation of virulence and drug resistance in Burkholderia thailandensis BPM,and can become a new target for the treatment of infections caused by Burkholderia thailandensis.

Objective:To analyze the risk factors of recurrence and canceration for premalignant vocal fold lesions after surgery, and to provide a reasonable basis for preoperative evaluation and postoperative follow-up. Methods:This study retrospective analyzed the relationship between clinicopathological factors and clinical outcome（recurrence, canceration, recurrence-free survival, and canceration-free survival） in 148 patients undergoing surgical treatment in Chongqing General Hospital from 2014 to 2017. Results:The five-year overall recurrence rate was 14.86% and the overall recurrence rate was 8.78%. Univariate analysis showed that smoking index, laryngopharyngeal reflux and lesion range were significantly associated with recurrence（P<0.05）, and smoking index and lesion range were significantly associated with canceration（P<0.05）. Multivariate logistic regression analysis showed that smoking index ≥600 and laryngopharyngeal reflux were independent risk factors for recurrence（P<0.05）, and smoking index ≥600 and lesion range ≥1/2 vocal cord were independent risk factors for canceration（P<0.05）. The mean carcinogenesis interval for the postoperative smoking cessation group was significantly longer（P<0.05）. Conclusion:Excessive smoking, laryngopharyngeal reflux and a wide range of lesions may be related to postoperative recurrence or malignant progression of precancerous lesions in the vocal cord, and further large-scale multi-center prospective randomized controlled studies are needed to clarify the effects of the above factors on recurrence and malignant changes in the future.
Humans ; Vocal Cords/pathology* ; Retrospective Studies ; Laryngopharyngeal Reflux/complications* ; Prospective Studies ; Precancerous Conditions/pathology* ; Risk Factors

Objective : To study diagnostic value of ultrasonic cardiography (UCG) for right heart occupying lesions (RHOL).Methods :A total of 48 RHOL patients ,who were diagnosed in our hospital from Jan 2014 to Jun 2017 , were selected .All patients received UCG and pathological examination to determine lesion location and type .With pathological examination as gold standard ,diagnostic coincidence rate of UCG for RHOL type was analyzed .Re‐sults :RHOL distribution :compared with superior&inferior vena cava ,there were significant rise in percentages of RHOL located at right atrium ,right ventricle and pulmonary artery (6.25% vs.31.25%, 29. 17%, 33. 33%) , P＜0.01 all.RHOL type :percentage of malignant occupation was significantly higher than those of thrombus and myxoma (54.17% vs.20. 83%, 25.00%) , P＜0. 01 both .With pathological examination as gold standard ,diag‐nostic coincidence rates of UCG for thrombus ,malignant occupation and myxoma were 80.00%, 92. 86% and 100% respectively ,there was no significant difference among them , P＝0. 220 .A total of 18 cases (37.50%) with peri‐cardial effusion were found by UCG ,including two cases (4. 16%) who were diagnosed as benign thrombotic lesion by pathological examination ,and the other 16 cases (33.33%) were caused by malignant RHOL invading right heart system ,which included two cases (4.16%) of essential RHOL and 14 cases (29. 17%) with malignant lesion heart metastasis from other sites .Conclusion :RHOL type mainly includes thrombus ,malignant occupation and myxoma , and malignant occupation possesses relatively high incidence rate ,and it usually comes from malignant tumor metas‐tasis from other sites .Accuracy of UCG is high in diagnosing RHOL ,which is worth extending .