AIM To determine whether Hb3 and its fragment F(ab')2 have practical value in radioimmunoimaging of colorectal cancer.METHODS Intact Hb3 was purified by hydroxylapatite chromatography. The fragment F(ab')2 was...AIM To determine whether Hb3 and its fragment F(ab')2 have practical value in radioimmunoimaging of colorectal cancer.METHODS Intact Hb3 was purified by hydroxylapatite chromatography. The fragment F(ab')2 was prepared by cold digestion and purified as intact Hb3. Hb3 and its fragment F(ab')2 were labeled with 99mTc by direct labeling method using SnCl2 as reducing agent. The radioactive doses ranged from 15 to 40 mCi. The imaging was accomplished by single photon emission computered tomograph (SPECT) with imaging time ranging from 2.5 to 48 hours. In this study, 10 patients were selected. Among them, 7 were administered with intact Hb3, and 3 with F(ab')2 fragment. All the patients were diagnosed as having colorectal adenocarcinoma.RESULTS After purification, intact Hb3 and its fragment F(ab')2 were fit for radioimmunoimaging. The percentage of labeling of 99mTc to Hb3 or F(ab')2 was 80.6%-91.5%. Among the 10 patients, 3 of 7 patients administered with intact Hb3 had positive scans, the other 4 had negative scans, and 2 of 3 patients administered with F(ab')2 had positive scans, the other 1 had negative scans.CONCLUSION The results showed that both intact Hb3 and its F(ab')2 have some practical value in radioimmunoimaging of colorectal cancer, and the effects of imaging with F(ab')2 was better than that with intact Hb3.展开更多
文摘AIM To determine whether Hb3 and its fragment F(ab')2 have practical value in radioimmunoimaging of colorectal cancer.METHODS Intact Hb3 was purified by hydroxylapatite chromatography. The fragment F(ab')2 was prepared by cold digestion and purified as intact Hb3. Hb3 and its fragment F(ab')2 were labeled with 99mTc by direct labeling method using SnCl2 as reducing agent. The radioactive doses ranged from 15 to 40 mCi. The imaging was accomplished by single photon emission computered tomograph (SPECT) with imaging time ranging from 2.5 to 48 hours. In this study, 10 patients were selected. Among them, 7 were administered with intact Hb3, and 3 with F(ab')2 fragment. All the patients were diagnosed as having colorectal adenocarcinoma.RESULTS After purification, intact Hb3 and its fragment F(ab')2 were fit for radioimmunoimaging. The percentage of labeling of 99mTc to Hb3 or F(ab')2 was 80.6%-91.5%. Among the 10 patients, 3 of 7 patients administered with intact Hb3 had positive scans, the other 4 had negative scans, and 2 of 3 patients administered with F(ab')2 had positive scans, the other 1 had negative scans.CONCLUSION The results showed that both intact Hb3 and its F(ab')2 have some practical value in radioimmunoimaging of colorectal cancer, and the effects of imaging with F(ab')2 was better than that with intact Hb3.
