| 摘要 |
The diagnostic agent can be injected intravenously and contains a fragment, which is labelled with a gamma- or positron-emitter, of human plasminogen, e.g. <123>I-neoplasmin. The radiolabelled plasminogen fragment which has been introduced into the veins collects at the site of a thrombus so that an increased radioactive emission occurs there and can be detected by one of the known techniques of nuclear medicine only 15 to 30 minutes after injection of the diagnostic agent. To prepare the diagnostic agent, human plasminogen is cleaved with elastase, and neoplasminogen is obtained from the reaction mixture and is then labelled with a radioactive halogen or metal ion so that a chemical bond between the radioactive atom and free tyrosine groups or amino groups of the neoplasminogen is produced. Only about 15 minutes before the intravenous injection is the labelled neoplasminogen biologically activated by addition of urokinase, and thus the formation of radiolabelled neoplasmin initiated. This diagnostic agent not only makes rapid, non-invasive and relatively accurate diagnosis of a thrombosis possible, but also achieves avoidance of unpredicted side effects during the subsequent breakdown in the human body. |
