Quantification of antigen of Mycoplasma capricolum subsp. capripneumoniae by optical assay / 生物工程学报

Mycoplasma capricolum subsp. capripneumoniae (Mccp) is the cause of contagious caprine pleuropneumonia (CCPP) in goats. Inactivated vaccines and capsular polysaccharide (CPS) indirect hemagglutination reagents are available for prevention and serological detection, but high culture costs and complex antigen quantification have been plagued by production staff. In order to solve these problems in production practice, a sugar fermentation medium with an initial pH value of 7.8, which could improve the production of two antigens simultaneously, was screened out by changing the initial pH value based on previous Mccp metabolomics analysis. Since phenol red can be identified by UV absorption spectrum and cetyltrimethylammonium bromide (CTAB) can bind to anionic capsular polysaccharide, a UV spectrum measurement method for analyzing the culture stage reached by Mccp and a CTAB precipitation test for relative quantification of capsular polysaccharide antigen content in the fermentation broth were established. The UV spectrum observation method can guide the production of Mccp according to the growth curve of Mccp, which greatly reduces the monitoring time of the traditional CCU method and improves the accuracy of the original eye-observation method. The established CTAB precipitation test can complete the monitoring of CPS content within 5 hours, which greatly reduces the time required compared with the traditional differential technique, and its accuracy was verified by the phenol-sulfuric acid method. The optimized culture medium and the two correlation comparison methods established in this study can effectively reduce the production cost of Mccp and improve the production efficiency. The two assays have been used in the research at our laboratory, which provides experimental data for further improvement of the production process of CCPP inactivated vaccine and capsular polysaccharide as well as rapid quantification.

Validity and reliability of the Chinese version of Mobile Phone Involvement Questionnaire in college students / 南方医科大学学报

OBJECTIVE@#To test the validity and reliability of the Chinese version of Mobile Phone Involvement Questionnaire (MPIQ) in college students.@*METHODS@#We assessed the degree of phone dependence using the MPIQ among 2122 college students. One month later, 60 students were randomly selected for assessment with the MPIQ, and the ROC curve was generated to evaluate the true positive rate (sensitivity) and false positive rate at different cutoff values to determine the optimal cutoff score of the MPIQ.@*RESULTS@#Among 98.9% of the participants who finished all the items, their MPIQ scores show a positive skew distribution and a one-factor structure. The load scores of the items ranged from 0.54 to 0.77. The Cronbach's α coefficient and the Spearman Brown split reliability were 0.84 and 0.83, respectively, the correlation coefficients between the items and total score ranged from 0.54 to 0.76, and the test-retest reliability was 0.48 ( < 0.001). At the optimal cut-off score of 32, the sensitivity and the specificity of the MPIQ were 0.634 and 0.652, respectively.@*CONCLUSIONS@#At the optimal cut-off score of 32, the MPIQ has good validity and reliability for assessing phone dependence among college students.

Association of mobile phone overuse with sleep disorder and unhealthy eating behaviors in college students of a medical university in Guangzhou / 南方医科大学学报

OBJECTIVE@#To investigate the association of mobile phone use with sleep disorder and unhealthy eating behavior among college students of a medical university in Guangzhou.@*METHODS@#Mobile Phone Involvement Questionnaire (MPIQ), Pittsburgh Sleep Quality Index (PSQI) and the Three Factor Eating Questionnaire Revised 21 Item (TFEQ-R21) were used to survey 2122 undergraduates of the medical university. One-sample t test, One-way ANOVA and multiple linear regression analysis were used to analyze the data.@*RESULTS@#Age, body mass index (BMI), phone use before sleep, phone use frequency, sleep quality (assessed by total PSQI score) and the dimension scores of TFEQ-R21 for uncontrolled eating, cognitive restraint, and emotional eating were all significantly correlated with the total score of MPIQ ( < 0.05). Phone use before sleep, high frequency of mobile phone use, poor sleep quality and emotional eating were associated with high MPIQ scores, while lower cognitive restraint and emotional eating tendency were correlated with lower scores of MPIQ. Bivariate analysis revealed that age (=0.088, < 0.001), BMI (=0.055, < 0.05), PSQI scores (=0.204, < 0.001), TFEQ-UE scores (=0.199, < 0.001), TFEQ-CR scores (=-0.076, < 0.001), TFEQ-EE scores (=0.170, < 0.001), phone use before sleep (=0.429, < 0.001), and phone use frequency (=0.316, < 0.001) were all significantly correlated with MPIQ scores; multiple linear regression analysis showed that model 4 incorporating the scores of TFEQ-UE, TFEQ-CR, and TFEQ-EE explained up to 21.8% of the main effect (adjusted R= 21.5%).@*CONCLUSIONS@#Mobile phone overuse is associated with poor sleep quality and unhealthy eating behaviors, and education and interventions for mobile phone use is essential among college students.

Cloning and prokaryotic expression of the ompA gene of Chlamydia psittaci in cows / 中国人兽共患病学报

The ompA gene of Chlamyia psittaci in cows was amplified by PCR with primers designed based on those reported in GenBank.The amplified ompA gene was inserted into the bacterial plasmid vector pGEX-4T-1 and then transformed into E.coli BL21(DE3) with IPTG induction. The gene was derived from plasmid pMD18-T vector and then sequenced.It was demonstrated that this recombinant fusion protein of approximately 68kD in molecular mass was highly expressed in inclusion body and more pure proteins would be produced after purification.The fusion protein specifically reacted with positive sera of bovine Chlamydia as demonstrated by Western blotting. These results indicate that this recombinant fusion protein shows good reactivity and could be used to develop the diagnostic kit for bovine Chlamydia and genetic engineering vaccine.

An Indirect ELISA of Classical Swine Fever Virus Based on Quadruple Antigenic Epitope Peptide Expressed in E.coli / 中国病毒学·英文版

In this study,a synthesized quadruple antigenic epitope gene region of the classical swine fever virus (CSFV)E2 glycoprotein was expressed in E.coli to a obtain target protein.This target protein was used as a coating antigen to establish an indirect ELISA for specifically detecting anti-CSFV antibodies in serum samples from pigs.The P/N cut-off value of this assay was 1.92 by receiver operating characteristic curve(ROC)analysis based on 30 negative sera and 80 positive samples.The test gave 97.5% sensitivity and 96.7% specificity compared with the indirect hemagglutination(IHA)test.The inter-assay and intra-assay coefficients of variation (CVs)for 16 sera were both ≤6.8%.No cross-reactivity between the coating antigen and anti-bovine viral diarrhoea virus(BVDV)antibodies was observed.

Secretory Expression of E2 Main Antigen Domain of CSFV C Strain and the Establishment of Indirect ELISA Assay / 中国病毒学·英文版

The sequence encoding an E2 main antigen glycoprotein of the C strain of classical swine fever virus (CSFV) was highly expressed in the host cell E. coli BL21-CodonPlus (DE3)-RIL using the pGEX-4T-1 expression vector and the soluble recombinant product was purified with Glutathione Sepharose TM<'4B> by centrifugation. The soluble recombinant protein showed good immune reactions and was confirmed by Western blot using anti-CSFV-specific antibodies. Then an indirect ELISA with the purified E2 protein as the coating antigen was established to detect antibody against CSFV. The result revealed that the optimal concentration of coated antigen was 0.6 μg/well and the optimal dilution of serum was 1:80. The positive cut-off value of this ELISA assay was OD<,tested serum>/OD<,negative serum>≥2.1- The E2-ELISA method was evaluated by comparison with the indirect hemagglutination test (IHAT). When a total of 100 field serum samples were tested the sensitivity and specificity were 90.3% and 94.7% respectively. Specificity analysis showed that there were no cross-reactions between BVD serum and the purified E2 protein in the E2-ELISA.