[Sensitivity tests of malignant tumours against cytostatic agents in vitro and in vivo/studies on the mouse sarcoma 180 (author's transl)].

The effects of ten different substances on the mouse sarcoma 180 have been compared using in vivo and in vitro test systems. The size of the tumours was taken as a measure of the success of the therapy in animal experiments. The in vitro effects were estimated by measuring the incorporation of radioactively labelled uridine in tumour cell suspensions from solid tumours, in ascites tumours and in tissue culture.

[Testing of the resistance of human tumours in the short-term test (author's transl)].

Various human tumours have been investigated using, as previously described an in vitro method for sensitivity testing. This test provides information both on the rates of proliferation of tumours and on their resistance to cytostatic agents.

[Incorporation of a 131-iodine-deoxycytidine monophosphate protamine complex into the DNA of tumor-bearing rats following partial synchronization with hydroxyurea].

The incorporation of 131-Iodo-deoxyuridine in rat tumours can be increased by partial synchronisation with hydroxyurea. The reported investigation was carried out to determine whether the incorporation could be further increased by using a basic 131-Iodo-deoxycytidine-monophosphate-protamine complex as a depot of Iodo-deoxyuridine. It was shown that the incorporation observed after synchronisation could be increased by using this complex (non-synchronized tumours 1,46% retention, synchronized tumours 2,28% retention; measured 4 hour after the final injection of hydroxyurea) whereas in a control group injected with 131-Iodo-deoxycytidine-monophosphate alone, only a small increase was observed.

[Possibilities and limits of pre-therapeutic neoplasm sensitivity cytostatics tests under short-term conditions].

The following cytostatic agents were tested for activity in vivo and in vitro inWalker carcinosarcoma 256 of the rat: cyclophosphamide, triaziquon, 5-fluorouracil, methotrexate, adriamycin, dactinomycin, daunorubicin, hydroxyurea, procarbazin and vincritine. With the exception of vincristine, the results of therapy in vivo could be predicted by using a rapid in vitro test system. This involved, for cyclosphosphamide, triaziquon, adriamycin, and daunorubicin, the measurement of 3H-uridine or 3H-thymidine incorporation.

[The effect of cyclophosphamide on tumors in the sensitivity-test (author's transl)].

The sensitivity of tumors to cyclophosphamide was tested in vitro. For this purpose, the urine of cyclophosphamide-treated rats (90 min., 500 mg/kg) was used.

Pharmacokinetics of guanazole in patients with acute myelocytic leukemia.

Levels of guanazole (GZ) in plasma and packed cells were determined after a single tracer dose of 14C-guanazole or during a 5-day continuous intravenous therapeutic infusion of unlabeled drug to 5 patients with acute myelocytic leukemia (AML). The levels of unlabeled drug were determined colorimetrically. GZ infected as a tracer dose was rapidly distributed in an apparent volume of 0.

Sensitivity tests of tumors to cytostatic agents. II. Investigation on human tumors.

Certain substances which influenced nucleic acid metabolism were found to have about the same cytostatic activity on human cells when measured in tissue culture experiments (cell numbers) or in short-term cultures (3-H-uridine incorporation in cell suspensions). By treatment with a dose of cytostatics corresponding to 10 times therapeutic dose, chemosensitive tumors can be distinguished from non-responsive tumors. By using this in vitro test system to investigate the sensitivities of 100 human tumors, it is shown that 28 of these tumors were responsive to adriamycin, daunomycin and Actinomycin D.

Sensitivity tests of tumors to cytostatic agents. I. Comparative investigations on transplanted tumors in vivo and in vitro.

With series of transplanted tumors, the activities of different cytostatic agents which directly influence the metabolism of nucleic acids (Actinomycin D, adriamycin, daunomycin, 5-fluorouracil, procarbazine, trenimon) was measured by determining 3-H-uridine incorporation in short-term (3hrs) incubations of tumor cell suspensions. Data obtained could be used to predict the response of each tumor to particular cytostatic agents in vivo. The activities of the cytostatic agents as determined using long-term tissue cultures (time of exposure of tumor cells to cytostatic agent 48 hrs were comparable to those obtained with the short-term test.

[Correlation of in vitro testing and therapeutical results in animal transplanted tumors after cytostatic treatment].

The antineoplastic activity of 5 substances was tested in vivo and in vitro on four different tumours (plasmocytoma and melanoma Fortner III of the Syrian golden hamster, the Walker carcinosarkoma 256 and an adenocarcinoma of the rat). The substances involved were 2,3,5-triethyleniminobenzoquinone-(1,4) (triaziquone), actinomycin D, podophyllinic ethylhydrazide (mitopodozide), bleomycin and adriamycin hydrochloride. The effect of the substances in vivo was measured on the size of the tumour, and in vitro on the incorporation of 3-H-thymidine and 3-H-uridine in short-term incubations of tumour-cell suspensions.