[Changes in biological properties of malignant melanoma B-16 after transplantation to (CBA x C57Bl/6)F1 mice]. / Izmenenie biologicheskikh svoistv zlokachestvennoi melanomy B-16 pri transplantatsii mysham (CBA x C57Bl/6)F1.

The primary tumour properties are studied for their effect on the recurrent tumour growth and metastatic spreading after chemotherapy. Serial transplantation of the B16 melanoma to (CBA X C57Bl/6)F1 mice induced gradual changes in tumour malignancy. With an increase of the generation number the metastatic activity of hybrid mice rises and chemotherapeutic sensitivity lowers. The thirty-first and the fifty-fourth tumour generations after the chemotherapy metastasize earlier and the number of metastases increases more rapidly as compared with the recurrence of the primary tumour. The metastatic potential of recurrent tumours increases with the number of generations in hybrid mice.

[Growth characteristics of adenocarcinoma 755 recurrences in C57Bl/6 and (DBA/2 X C57Bl/6) F1 mouse strains]. / Osobennosti rosta retsidivov adenokartsinomy 755 u myshei linii C57Bl/6 i (DBA/2 X C57Bl/6) F1.

Peculiarities of growth and recurrences of the adenocarcinoma 755 are studied in C57Bl/6 mice and hybrids (DBA/2 X +C57Bl/6)F1 after chemotherapy with cyclophosphamide and 6-mercaptopurine (6-MP). The growth rate of tumours was practically identical in the both mice strains. Growth rate of recurrences was slower in examined lines than in corresponding tumours. The obtained results showed that the antitumour effect of the drugs, in particularly of 6-MP, and the growth rate of the first and that of the second recurrences clearly depended on the tumour host strain.

[Tumor heterogeneity and the mechanisms of natural resistance in the metastatic process]. / Geterogennost' opukholi i mekhanizmy estestvennoi rezistentnosti pri metastazirovanii.

Data from literature concerning differences in cell populations between the primary and metastatic tumours are generalized. Their properties are considered as dependent on heterogeneity of the cell composition, karyotype, cell surface peculiarities and oncogene expression. The problem of the dependence of the ability of tumours to metastasize on their interaction with macrophages and natural killer cells is under discussion.

[Kinetics of the cell population in adenocarcinoma 755 after cyclophosphane administration and rate of tumor growth after an additional course of therapy with cyclophosphane and 6-mercaptopurine]. / Kinetika kletochnoi populiatsii adenokartsinoma 755 posle vvedeniia tsiklofosfana i skorost' rosta opukholi posle povtornogo kursa terapii tsiklofosfanom i 6-merkaptopurinom.

The two injections of cyclophosphane (100 mg/kg) to mice with adenocarcinoma 755 on the 6th and 11th days after tumour transplantation had no influence on the cell cycle but induced a decrease of its growth rate due to an increase in the level of cell losses. The third cyclophosphane injection (the same dose) on the 17th day after the tumour transplantation or an additional course of five 6-mercaptopurine injections (50 mg/kg each dose) did not change essentially the growth rate of tumours.

[Cellular proliferation kinetics of Walker carcinosarcoma, Zajdela's ascitic hepatoma and their metastases to the lymph nodes]. / Kinetika kletochnoi proliferatsii kartsinosarkomy Uoker, astsitnoi gepatomy Zaidela i ikh metastazov v limfaticheskie uzly.

The cell cycle of Walker carcinoma, Zajdela's hepatoma and their metastases into regional lymph nodes are studied. It is shown that cell cycle of metastases is shorter and the labeling index is higher than in primary tumours. The cell cycle shortening in Walker carcinosarcoma metastases is associated with a decrease in the duration of all its phases. The cell cycle of Zajdela's hepatoma metastases decreases with the S-phase length. The cell loss factor of primary tumours is less than that of their metastases. The results of the autoradiographic study correlate with the previously studied sensitivity of primary tumours and metastases to chemotherapy.

[Effect of thiophosphamide, its paramagnetic analogs and the iminoxyl radical on the division of tumor cells]. / Vliianie tiofosfamida, ego paramagnitnykh analogov i iminoksil'nogo radikala na delenie opukholevykh keltok.

The authors have studied the effect of thiophosphamide its paramagentic analogs and iminoxyl radical on cell reproduction of Ehrlich ascites tumor. It was shown that the effect of paramagnetic analogs is made up of a sum of injuries produced by ethylenimine and iminoxyl portions of molecules. One of the analogs involved proves to be more active than thiophosphamide.

[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.

[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.