[Nitroxyl radical Tempol as a modulator of toxic and antineoplastic effect of 6-mercaptopurine]. / Nitroksil'nyi radikal tempol kak moduliator toksicheskogo i protivoopukholevogo deistviia 6-merkaptopurina.

Both intact mice and those with transplantable adenocarcinoma 755 were used in the investigation. The nitroxyl radical Tempol was shown to cut down the toxicity of 6-mercaptopurine and potentiate its antitumor effect to a certain degree. The study results suggest on the basis of an investigation of cytochrome P450 and some other evidence that said effect of Tempol might be due, at least, in part to antioxidant activity.

[The antimetastatic effect of low doses of lonidamine]. / Antimetastaticheskii éffekt nizkikh doz lonidamina.

Antimetastatic activity of a wide range of Lonidamine doses, including low and ultralow doses, was studied. Low doses of the drug were shown to affect the frequency and intensity of metastasis formation.

[Sensitivity of human tumor heterografts to a spin-labelled rubomycin derivative]. / Chuvstvitel'nost' geterotransplantatov opukholei cheloveka k spin-mechenomu proizvodnomu rubomitsina.

A degree of emoksil activity has been determined by applying the subrenal capsule assay methodology to fresh surgical explants of the normal immunocompetent mice. The ability of emoksil to inhibit growth of breast and colon tumours xenografts was determined. Emoksil substitution for adriamycin in the combination therapy increases the therapeutic activity. The kinetic criterion kappa calculated by the method of equivalent exponents was suggested to determine the tumour susceptibility to the drugs.

[Nitroxyl derivatives of rubomycin]. / Nitroksil'nye proizvodnye rubomitsina.

The toxic and antitumor effects of new analogs of rubomycin were studied. It was shown that the spin-labeled derivatives had the lowest toxicity and highest antitumor activity. The diamagnetic analog was similar to rubomycin in its antitumor effect. It was demonstrated that ruboxyl-l had a lower cardiotoxicity than rubomycin and did not inhibit hemopoiesis at the maximum tolerated doses.

[Changes in the proliferative activity of human breast cancer cells cultivated in vivo in diffusion chambers in response to antineoplastic agents]. / Izmenenie proliferativnoi aktivnosti kletok raka molochnoi zhelezy cheloveka, kul'tiviruemykh v diffuzionnykh kamerakh in vivo, pod deistviem protivoopukholevykh preparatov.

A study was made of the effect of nitrosomethylurea (NMU), thiophosphamide and diazane on proliferative activity of human breast cancer cells cultured in diffusion chambers in vivo. NMU highly suppressed the proliferation of human breast cancer cells throughout the experiment. The maximum effect of diazane and thiophosphamide became apparent after 24 hours, while almost complete renewal of the proliferation was observed by the 72nd hour of culture. Diazane and NMU hold promise for clinical trials in human breast cancer.

[Joint therapy of experimental tumors with diazan in combination with antibiotics]. / Kombinirovannaia terapiia éksperimental'nykh opukholei v sochetanii s antibiotikami.

Antitumor efficiency of combined therapy of experimental tumors with diazan and antibiotics was studied. The experiments were performed with leukosis La and P-388 and Walker carcinosarcoma. The kinetic regularities of the tumor process were used in planning regimens of the combined therapy. It was found that the combined use of diazan with antitumor antibiotics of the anthracyclin series increased the therapy efficacy. Therapeutic synergism of the drugs was noted which was evident from a significant increase in the average life rate and recovery of a part of the animals.

[Combination chemotherapy of experimental leukemia]. / Kombinirovannaia khimioterapiia eksperimental'nykh leikozov.

In the present work an attempt was made to gain greater therapeutic effect of diazane coupled with adriamycin and sarcolysin. Leucemias L-1210 and La served as a model. In leucosis La diazane was injected once in 5 days. Either an additional injection of adriamycin two days prior to diazane injection or sarcolysin injected simultaneously with diazane enabled the authors to obtain a distinct synergestic effect. In leucemia L-1210 a simultaneous administration of diazane and sarcolysin also contributes to considerably longer survival of leucemic animals. Such combinations are likely to be promising in their clinical use.

[Kinetic study of the effectiveness of chemotherapy of experimental metastases (using a computer)]. / Kineticheskoe izuchenie éffektivnosti khimioterapii metastazov v éksperimente (s primeneniem EVM).

Under study was the influence of active antitumor substances on experimental metastasizing tumors. The method for assessment of their efficacy, using an electronic computer, is suggested. Significant differences in the action of the substances on primary tumors and their metastases are shown.

[Bifunctional derivatives of N-nitroso-alkylurea]. / Bifunktsional'nye proizvodnye N-nitrozoalkilmochevin

Toxic cumulative and antitumor properties of bifunctional N-nitroso-alkylureas as compared with their monofunctional analogues were stuied. Newly produced compounds render a considerable antitumor effect on a number of experimental tumors. A conclusion may be drawn that despite changes in the chemical structure an active metabolic fragment both of mono- and bifunctional compounds is the same, as also evidenced by the cumulation index. However, inspite of a rather high antitumor activity of bifunctional compounds their chemotherapeutic indices are very low.

[A kinetic analysis of the growth of transplanted tumors and their metastasis]. / Kineticheskii analiz rosta perevivnykh opukholei i ikh metastazov

Under study were kinetic regularities in development and incorporation of tritium labelled thymidine into cells of two experimental metastasizing tumors -- Zajdela ascites hepatoma and Walker carcinosarcoma, transplanted intratesticulary. Primary tumors and their metastases in regional lymph nodes show certain differences relative both to the rate of the process and intensity of the DNA synthesis, and relative number of cells with incorporated labelled thymidine.