ABSTRACT
Objective To investigate whether specific cellular uptake of 99Tcm-survivin-ASODN in nude mice bearing human HCC is influenced by its cytosine content.Methods Three kinds(A1,A2,A3) of synthesized survivin ASODN with three cytosine contents(10％,20％,30％),20 bases per single-strand were prepared.They were labeled with 99Tcm by conjugating with a bifunctional chelator HYNIC,purified through Cellufine GH-25 and then encapsulated with liposome.Antisense gene imaging and the biodistribution of 99Tcm-HYNIC-survivin ASODN in nude mice bearing HCC were performed.The data were analysed by Kruskal-Wallis H test.Results At 4 h post injection,all the 3 labelled compounds showed increased uptake by tumor,liver and kidney.With increase in cytosine content,the uptake increased in kidney (％ID/g:1.50±0.06,2.80±0.09 and 3.96±0.03),and decreased in tumor (％ID/g:2.08±0.08,1.69±0.01 and 1.20±0.09).T/NT in imaging (4.49-4.93,4.12-4.21,3.35-3.85;H=12.50,P＜0.05) and in biodistribution (4.08-4.94,4.02-4.18,3.66-3.85;H=10.82,P＜0.05) were all significantly different.Conclusion ASODN with lower cytosine content shows higher uptake by HCC tumor cells and less stasis in kidneys,thus providing better quality in antisense gene imaging.
ABSTRACT
Objective To investigate the diagnostic efficiency of 64-slice CT coronary angiography (CTCA) to myocardial ischemia of coronary stenosis. Methods ~(99m) Tc-MIBI myocardial perfusion imaging (MPI) and 64-slice CTCA were performed in 30 patients with myocardial ischemia of coronary stenosis. Three coronary arteries were divided in to 12 segments in each patient, the diagnostic efficiency of CTCA to myocardial ischemia of coronary stenosis were eveluated taking MPI as diagnostic standard, and stenoses ≥50% and ≥75% as the cutoff value. Results In 9 patients, perfusion defected were found (6 reversible, 3 fixed) on MPI. A total of 327 coronary arteries' segments were analyzed, quantitative CTCA revealed stenoses ≥50% in 25 segments (7.65%) and stenoses ≥75% in 12 segments (3.67%). When the cut-off was ≥50%, the sensitivity, specificity, negative and positive predictive value (NPV, PPV) and accuracy of CTCA by the abnormal images of MPI as diagnostic standard to observe abnormal arteries was 68.42%, 96.14%, 99.01%, 52.00% and 95.41%, respectively; and 66.67%, 99.04%, 98.73%, 66.67% and 97.55%, respectively, when cut-off at ≥75%. Taking abnormal MPI as diagnostic standard to observe the patients, the sensitivity, specificity, NPV, PPV and accuracy of CTCA was 66.67%, 57.14%, 80.00%, 40.00% and 60.00% respectively, with the cut-off at ≥50%; and was 55.56%, 85.71%, 81.82%, 62.50% and 76.67%, respectively, with the cut-off at ≥75%.Conclusion Sixty-four-slice CTCA is a reliable tool to rule out functionally relevant myocardial ischemia of coronary artery disease. However, further examination is necessory for patients with abnormal CTCA.