Uptake of main fractions of labelled bleomycin by solid Ehrlich ascites tumours in mice.

Concentrations were studied of 58Co in the solid Ehrlich ascites tumour, blood, muscle and bone of male Swiss mice administered as complexed with total bleomycin commercially available and its isolated fractions A2, B2, demethyl A2, A1, A5, B4 and bleomycinic acid. The tumour/non-tumour ratios were determined 24 hrs after injection of the complexes. The ratios for fraction A2, B2 and total bleomycin were very close to each other. The remaining fractions showed lower values of the ratios. These results suggest that it is unlikely that any of the fractions studied are superior to total labelled bleomycin with respect to tumour scintigraphy.

Uptake of labelled tallysomycin by solid Ehrlich ascites tumors in mice.

Tumor and normal tissue uptake of 51Cr- or 57Co-labelled bleomycin (BLEO) and tallysomycin (TLM) was compared in female solid Ehrlich ascites tumor mice of Swiss strain. The complexes were administered intraperitoneally: 30-50 micrograms of each complex with an activity of 40-120 microCi. Activity distribution factors (ADF) and tumor/non-tumor ratios for blood, bone, skeletal muscles, kidneys and liver were determined. The ratios were generally higher for complexes labelled with 57Co than for the 51Cr-labelled ones; bleomycin appears equivalent or superior to tallysomycin.

51Cr-bleomycin, a new oncophilic radiopharmaceutical. I. Activity concentrations in transplantable tumours and organs-tissues of mice.

A method was developed for labeling bleomycin with 51Cr. The complex was administered to mice (Swiss and C57-B1/6) bearing 5 transplantable tumours: Ehrlich ascites tumour, NK/Ly lymphoma, Lewis lung carcinoma, melanoma B-16, and Sarcoma 180. Activity concentration in neoplasms, blood and numerous organs was determined 12, 24 and 48 hrs after injection. An identical procedure was applied using 58Co-bleomycin as a reference oncophilic substance. Tumour/non-tumor ratios exceeding substantially unity were found for blood, muscle and bone indicating preferential accumulation of both 58Co and 51Cr in all the neoplasms tested. The ratios were lower (by a factor 2-3) for 51Cr than for 58Co; however, it is postulated that the gamma-quantum energy of 51Cr which is higher than that of the commonly used 57Co, should offset to some degree this difference when scintigraphic tumour detection in a patient is to be attempted. In conclusion, clinical trials with 51Cr-bleomycin, which is cheaper than its 57Co-counterpart, appear warranted.

51Cr-bleomycin, a new oncophilic radiopharmaceutical. II. Scintigraphic diagnosis of malignant neoplasms.

51Cr-bleomycin was used for the scintigraphic detection of tumours and the assessment of the spread of the disease in 20 patients with various malignancies: 7 with Hodgkin's lymphoma, 5 with other malignant lymphomas, 4 cases of cervix carcinoma and 4 other tumours. The scintigraphy was performed using a Toshiba GC 401 gamma camera coupled to an MDSI computer Trinary. Active foci were scored using a semiquantitative scale of 0 to 5. Results of these studies were compared with those of tests similarly carried out with 57Co-bleomycin (in 9 of the cases) and 67Ga-citrate (11 cases); they demonstrated that the properties of 51Cr-bleomycin for scintigraphic detection of neoplastic foci are similar to those of 57Co-bleomycin.

99mTechnetium-unithiol complex, a new pharmaceutical for kidney scintigraphy.

The investigations were carried out with a newly synthesised, original 99mTc-Unithiol complex (Unithiol-2,3-dimercaptopropansulphonate). It accumulates in the kidneys and enables their scintigraphic examination at 90--180 minutes after the administration. The study was performed on rats, rabbits and dogs. 99mTc-Unithiol complex accumulation in rat kidneys was 34,9%, 44,5% and 67,8% of dose after 1, 2 and 3 h respectively. Good reability of the scintigraphic picture of the kidneys in rabbits and dogs confirms the accumulative capability of the complex in these organs. It was found by means of ascending paper chromatography that the purity of the 99mTc-Unithiol complex exceeded 90%.