ABSTRACT
Objective To investigate the radiation dose differences of DTS,DR and CT in diagnostic imaging of the skeletal system and analyze the sensitivity and specificity of each modality in skeletal disease diagnosis.Methods 100 relevant patients with skeletal diseases were randomly selected,who were performed with DR,DTS and CT from Feb 2010 to Mar 2012.They were divided into three groups,respectively as the DR group,the DTS group and the CT group.The complete information including DR,DTS,CT data and the final clinical diagnosis were collected and the statistical analysis after comparing radiation dose of DR,DTS and CT examination.Two experienced experts evaluated the image of three examinations and made judgments.ROC curves of reader A and B were made by using the final clinical diagnosis as gold standard.Results The average absorbed dose and effective dose of DR,DTS,CT group were [(1.9±1.8)mGy,(0.03±0.03) mSv)],[(3.5±1.5)mGy,(0.05±0.02) mSv)],[(397.7 ± 106.0) mGy· cm、(5.60 ± 1.50) mSy] respectively.The difference among the three groups was analyzed by one-way ANOVA test(F =1377,P ＜ 0.05) and had statistically significant(P ＜ 0.05).ROC curve was drawn through analyzing lesion detection credibility of three groups.The Az values of reader A and B was (0.870 ± 0.035,0.966 ± 0.018,0.974 ± 0.015) and (0.852 ± 0.038,0.951 ± 0.021,0.959 ±0.019)respectively.Do the Z-test to these examinations' area under ROC curve of lesion detection credibility.Between DR and DTS or DR and CT,there was statistically significant(P ＜ 0.05).While for CT and DTS,there was not statistically significant.The two readers' sensitivity and specificity in diagnosing skeletal lesion with DR,DTS and CT were investigated using the x2 test:CT and DTS were no statistical significance,CT and DR were statistically significant (x2 =4.833,P ＜ 0.05).Conclusions Radiation dose of DTS only accounts for about 1％ of CT examination.While its sensitivity and specificity can meet the requirements for clinical diagnosis as CT.If the DR diagnosis is unclear or suspected,DTS should be the first recommended modality used for skeletal diagnosis with lower radiation dose.
ABSTRACT
This study was carried out to compare HIV antibody detection by conventional method and serum dried in test tube and to check the stability of dried tube specimen (DTS) at ambient temperature. A total of 50 serum samples were tested for HIV antibodies, which were sent for testing in the state reference laboratory, by conventional method according to NACO guidelines. The same serum samples were dried in test tubes and then after elution with PBS again tested for HIV antibodies by same method and kits at 0 day and after 30 days. DTS eluted by PBS showed linear correlation to the serum samples. The antibodies in DTS were found to be stable at 37o c up to 30 days. This method is simple, sensitive and specific and can be used in resource limited settings embarking on scaling up of HIV testing.
ABSTRACT
The main objective of the present study was to find suitable DNA-targeting sequences (DTS) for the construction of plasmid vectors to be used to treat ischemic diseases. The well-known Simian virus 40 nuclear DTS (SV40-DTS) and hypoxia-responsive element (HRE) sequences were used to construct plasmid vectors to express the human vascular endothelial growth factor gene (hVEGF). The rate of plasmid nuclear transport and consequent gene expression under normoxia (20 percent O2) and hypoxia (less than 5 percent O2) were determined. Plasmids containing the SV40-DTS or HRE sequences were constructed and used to transfect the A293T cell line (a human embryonic kidney cell line) in vitro and mouse skeletal muscle cells in vivo. Plasmid transport to the nucleus was monitored by real-time PCR, and the expression level of the hVEGF gene was measured by ELISA. The in vitro nuclear transport efficiency of the SV40-DTS plasmid was about 50 percent lower under hypoxia, while the HRE plasmid was about 50 percent higher under hypoxia. Quantitation of reporter gene expression in vitro and in vivo, under hypoxia and normoxia, confirmed that the SV40-DTS plasmid functioned better under normoxia, while the HRE plasmid was superior under hypoxia. These results indicate that the efficiency of gene expression by plasmids containing DNA binding sequences is affected by the concentration of oxygen in the medium.