Burkholderia glumae causing seedling rot and grain rot of rice was listed as a plant quarantine disease of China in 2007. It＇s quite necessary to set up effective detection methods for the pathogen to manage further ...Burkholderia glumae causing seedling rot and grain rot of rice was listed as a plant quarantine disease of China in 2007. It＇s quite necessary to set up effective detection methods for the pathogen to manage further dispersal of this disease. The present study combined the real-time PCR method with classical PCR to increase the detecting efficiency, and to develop an accurate, rapid and sensitive method to detect the pathogen in the seed quarantine for effective management of the disease. The results showed that all the tested strains of B. glumae produced about 139 bp specific fragments by the real-time PCR and the general PCR methods, while others showed negative PCR result. The bacteria could be detected at the concentrations of 1×10^4 CFU/mL by general PCR method and at the concentrations below 100 CFU/mL by real-time fluorescence PCR method. B. glumae could be detected when the inoculated and healthy seeds were mixed with a proportion of 1：100.展开更多
Background Cytomegalovirus （CMV） remains a significant clinical problem among immunosuppressed renal transplant patients. Quantitative PCR assays have become the most common methods in the determination of CMV infec...Background Cytomegalovirus （CMV） remains a significant clinical problem among immunosuppressed renal transplant patients. Quantitative PCR assays have become the most common methods in the determination of CMV infections in transplant patients. This study was to determine the relationship between CMV infection and the acute rejection of the transplanted kidney. Methods Plasma samples from 77 renal transplant patients that were pre-transplant negative for CMV infection were tested using reaD-time quantitative PCR and CMV gene-specific primers. The detected viral loads were retrospectively compared with the acute rejection rate and the chronic or mild rejection rates of the renal transplant. Results CMV-DNA was detected in 29 of 77 recipients, yielding a positive rate of detection of 37.7% for this procedure. Twelve of the 21 recipients （57.1%） who suffered acute rejection had positive CMV-DNA. Among the 56 recipients suffered from chronic or mild rejection, 17 （30.4%） had positive CMV-DNA plasma. Moreover, of the 29 recipients who had detectable CMV-DNA after transplant, 12 （41.4%） suffered from acute rejection; of the 48 recipients with undetectable CMV-DNA, only nine （18.8%） developed acute rejection. Post-transplant patients with acute rejection had a higher rate （57.1% vs. 30.4%, P=0.03） of post-transplant CMV infection than those with chronic or mild rejection. Conclusion CMV infection is a risk factor of acute renal transplant rejection and CMV infection should be prevented and treated in renal transplant recipients.展开更多
Background Enamel demineralization occurs frequently during orthodontic treatment. In this study, we evaluated the changes of the density of mutans streptococcus （MS） in plaque after bracket bonding and using fluori...Background Enamel demineralization occurs frequently during orthodontic treatment. In this study, we evaluated the changes of the density of mutans streptococcus （MS） in plaque after bracket bonding and using fluoride adhesive on maxillary incisors by real time fluorescence-quantitative polymerase chain reaction （RT-FQ PCR）.Methods The study was designed as a self-paired test. Brackets were bonded with fluoride adhesive on the left side, while non-fluoride adhesive on the right side for each patient. Plaque samples were taken from the surfaces around the brackets of four maxillary incisors before brackets bonding and after the bonding 4 weeks later. The amount of MS was measured by RT-FQ PCR. The data obtained were analyzed statistically using the SPSS 11.5 version and the alpha level was set at 0. 05 （ 2-tailed）.Results The amount of MS in plaque increased significantly after bracket bonding （ P 〈 0.01 ）, whereas no significant differences were observed among four maxillary incisors both before and after brackets bonding （P 〉 0. 05 ）, and among the incisors using and not using fluoride adhesive （ P 〉 0. 05 ）.Conclusions The increase of the density of MS in plaque after bracket bonding is one of the etiological factors for enamel demineralization in orthodontic patients. The result of this study did not support what we observed clinically that the incidence of enamel demineralization for lateral incisors was higher than that for central incisors. Using fluoride adhesive for bonding did not affect the amount of MS in plaque in our study. Further study is needed.展开更多
基金supported by National Natural Science Foundation of China(Grant No.30671397 and No.30871655)the Public Beneficial Research Project of Agricultural Ministry,China(Grant No.nyhyzx07-056)
文摘Burkholderia glumae causing seedling rot and grain rot of rice was listed as a plant quarantine disease of China in 2007. It＇s quite necessary to set up effective detection methods for the pathogen to manage further dispersal of this disease. The present study combined the real-time PCR method with classical PCR to increase the detecting efficiency, and to develop an accurate, rapid and sensitive method to detect the pathogen in the seed quarantine for effective management of the disease. The results showed that all the tested strains of B. glumae produced about 139 bp specific fragments by the real-time PCR and the general PCR methods, while others showed negative PCR result. The bacteria could be detected at the concentrations of 1×10^4 CFU/mL by general PCR method and at the concentrations below 100 CFU/mL by real-time fluorescence PCR method. B. glumae could be detected when the inoculated and healthy seeds were mixed with a proportion of 1：100.
基金This work was supported in part by grants from the National Science Foundation of China （No. 81071431）, and from the Municipal New Star of Science and Technology of Beijing （No. 2010B054）.
文摘Background Cytomegalovirus （CMV） remains a significant clinical problem among immunosuppressed renal transplant patients. Quantitative PCR assays have become the most common methods in the determination of CMV infections in transplant patients. This study was to determine the relationship between CMV infection and the acute rejection of the transplanted kidney. Methods Plasma samples from 77 renal transplant patients that were pre-transplant negative for CMV infection were tested using reaD-time quantitative PCR and CMV gene-specific primers. The detected viral loads were retrospectively compared with the acute rejection rate and the chronic or mild rejection rates of the renal transplant. Results CMV-DNA was detected in 29 of 77 recipients, yielding a positive rate of detection of 37.7% for this procedure. Twelve of the 21 recipients （57.1%） who suffered acute rejection had positive CMV-DNA. Among the 56 recipients suffered from chronic or mild rejection, 17 （30.4%） had positive CMV-DNA plasma. Moreover, of the 29 recipients who had detectable CMV-DNA after transplant, 12 （41.4%） suffered from acute rejection; of the 48 recipients with undetectable CMV-DNA, only nine （18.8%） developed acute rejection. Post-transplant patients with acute rejection had a higher rate （57.1% vs. 30.4%, P=0.03） of post-transplant CMV infection than those with chronic or mild rejection. Conclusion CMV infection is a risk factor of acute renal transplant rejection and CMV infection should be prevented and treated in renal transplant recipients.
文摘Background Enamel demineralization occurs frequently during orthodontic treatment. In this study, we evaluated the changes of the density of mutans streptococcus （MS） in plaque after bracket bonding and using fluoride adhesive on maxillary incisors by real time fluorescence-quantitative polymerase chain reaction （RT-FQ PCR）.Methods The study was designed as a self-paired test. Brackets were bonded with fluoride adhesive on the left side, while non-fluoride adhesive on the right side for each patient. Plaque samples were taken from the surfaces around the brackets of four maxillary incisors before brackets bonding and after the bonding 4 weeks later. The amount of MS was measured by RT-FQ PCR. The data obtained were analyzed statistically using the SPSS 11.5 version and the alpha level was set at 0. 05 （ 2-tailed）.Results The amount of MS in plaque increased significantly after bracket bonding （ P 〈 0.01 ）, whereas no significant differences were observed among four maxillary incisors both before and after brackets bonding （P 〉 0. 05 ）, and among the incisors using and not using fluoride adhesive （ P 〉 0. 05 ）.Conclusions The increase of the density of MS in plaque after bracket bonding is one of the etiological factors for enamel demineralization in orthodontic patients. The result of this study did not support what we observed clinically that the incidence of enamel demineralization for lateral incisors was higher than that for central incisors. Using fluoride adhesive for bonding did not affect the amount of MS in plaque in our study. Further study is needed.
