[Experimental study of the antitumor properties and mechanism of action of kortifen].

Cortiphen, a newly developed hormonal cytostatic ester of 11-desoxy-17 alpha-hydroxycorticosterone and chlorophenacyl, is described. It was studied in transplantable, spontaneous and induced tumors of 7 sites: hemoblastosis (5), hepatoma (3), mammary gland (5), lung (2), gastrointestinal tract (3), sarcoma (2) and melanoma. Practically all the tumors were shown to respond to cortiphen action.

[The antineoplastic activity of testiphenon].

The paper describes the antitumor activity of a newly-developed hormonocytostatic drug testiphenon--a complex ether of 5 alpha-dihydrotestosterone and chlorphenacyl (17 beta-[n-di/2-chloroethyl/aminophenylacetate]-5 alpha-androstan-17 beta-ol-3-on). Its antitumor properties were studied in 15 models of transplantable solid tumors and systemic neoplasms of mice and rats such as sarcoma 298, sarcoma 37, sarcoma-180, Lewis lung epidermoid carcinoma, carcinoma of the forestomach-5, large bowel adenocarcinoma, Harding-Passey's melanoma, cervical cancer-5, mammary adenocarcinoma Ca-755, hemoblastosis La, plasmacytoma MOPC-406, Rauscher's erythroblastosis, Walker's carcinosarcoma 256, sarcoma 45, alveolar carcinoma of the mammary gland and DMBA-induced mammary tumors of mice. The spectrum of antitumor activity of testiphenon proved wider than those of its components or other estrogeno-cytostatic drugs--phenestrol and estracyt.

[Use of the peptide hormone melanostatin and its analogs for the synthesis of new antitumor compounds].

A hypothalamic hormone--melanostatin H-L-Pro-L-Leu-NH2- and its 9 analogs were synthesized and their antitumor properties studied. Melanostatin caused a 52-72% inhibition of tumor growth (p less than 0.05) in mice bearing adenocarcinoma of the mammary gland Ca-755, cervical carcinoma CC-5 and melanoma B-16.

[Effect of methylcobalamin on methotrexate transport in normal and tumorous tissues].

The effect of methylcobalamin on 3H-methotrexate uptake by tumor and normal tissues of mice with mammary adenocarcinoma (Ca-755) was studied. Methylcobalamin stimulated the rate of 3H-methotrexate influx into the tumor and small intestine but did not change its influx into the spleen. The effect was dependent on the dose of methylcobalamin.

[Disruption of DNA synthesis and structure of mouse L1210 leukemia cells, sensitive and resistant to 1-methyl-1 nitrosourea and 1,3-bis(2-chloroethyl)-1-nitrosourea in vivo].

Leukemia L1210 cells with acquired resistance to 1-methyl-1-nitrosourea (MNU) (L1210/MNU) and 1.3-bis(2-chloroethyl)-1-nitrosourea (BCNU) (L1210/BCNU) were developed from leukemia L1210 cells sensitive to these drugs (L1210/0). The modal chromosome number of leukemia L1210/MNU and L1210/BCNU cells increases from 40 (L1210/0) to 41.

[Changes in the content and composition of gangliosides of tumors as affected by chemotherapeutic agents].

The lipid-bound sialic acid (LSA) levels increased in the metastasizing Lewis lung carcinoma (3LL) and significantly decreased in blood plasma of the tumour-bearing mice after cyclophosphamide treatment correlating with the drug therapeutic effect. 5-fluorouracil that was less active in the used therapeutic doses did not cause similar changes in the LSA levels. No correlation was found between the LSA levels in adenocarcinoma 755 and the drug antitumour activity.

[Experimental study of an antitumor preparation proloteston].

The results of an experimental evaluation of a prolonged action antitumor drug--prolotestone are presented. The drug is a mixture of steroids of the androstane series, 2 alpha-methylhydrotestosterone and its three esters. The preparation has been approved for medication.

[Kinetics of the cell proliferation of murine mammary adenocarcinoma under the influence of methylcobalamine].

The mechanism of the stimulant effect of methylcobalamine on the growth of mouse adenocarcinoma 755 was studied. More rapid growth of adenocarcinoma 755 under the cobalamine coentzyme effect is consequent on an increased proliferative pool with the stable parameters of the mitotic cycle and minimal death of tumour cells. Apparently, inhibition of DNA synthesis in the greater S-phase cell subpopulation potentiated the antitumour effect of methotrexate combined with methylcobalamine.

[Effect of resection of the primary focus on matastasis of transplantable tumors].

The rate of metastasization was estimated by calculating the coefficients of the metastases involved lung mass and the number of metastatic nocules. The experiments with melanoma B-16 and Lewis carcinoma have shown a marked stimulating effect of removing the primary tumor node on metastases growth, the number of metastatic nodules in the lung being less compared with control, but these were larger. In experiments with carcinoma RL-67 the removal of the primary node would not stimulate the growth of metastases.

[Frequency, time and type of metastasis of different transplantable tumors in mice].

The character of metastasis of 9 strains of transplantable mouse tumours in conventional subcutaneous inoculation was studied. There were differences in the frequency, intensity, and types of metastasis of different tumours. Periods of onset of metastases of Lewis lung carcinoma and RL-67, and also of sarcoma-37 were established.

[Antitumor action of cis-dichlorodiammineplatinum(II) and the effectiveness of a combination with sarcolysine].

Therapeutic properties of cis-dichlorodiammineplatinum (II) were studied on 12 strains of transplantable tumors and leukemias in mice. The compound is characterized by a wide spectrum of antitumor action. The greatest effect was gained in adenocarcinoma of the lage intestine (strain AKATOL), proventricular cancer (strain PRG) and adenocarcinoma of the mammary gland (strain Ca-755).

[Determination of nucleic acids for estimation of tumor cell growth in diffusion chambers].

The use of spectrophotometric method of objective quantitative estimation of tumor cells growth in diffusion chambers and chemotherapeutic sarcolysin effect on them are described.