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While studying Guerin's carcinoma development under conditions of different vitamin A provision in the period of tumor growth and before it appearance, it was established, that strengthened saturation of an organism with a tumor by vitamin A hyper doses can both stimulate and inhibit tumor progression. The effect depends on duration of vitamin A administration and on the level of preliminary provision of an organism with this vitamin. The hyper doses administration for 7 days on the normal vitamin A provision background and the normal doses administration to vitamin A-deficient animals which is especially expressed antitumor effect. The continuation of hyper doses administration to 14 days leads to rising of tumor sizes, especially expressed in vitamin A-deficient animals.

Experiments on rats with inoculated sarcoma-45 combined with chlamydial infection showed activation of processes of lipid peroxidation already at early free radical stage of lipid peroxidation, that resulted in subsequent increase of activity of key antioxidant enzymes: superoxide dismutase and catalase. With progression of the tumour process developing under conditions of chlamydial infection the intensity of the increase of enzyme activity decreased.

The report discusses whether transcranial electrostimulation in cancer patients can be accepted. A number of tumors were inhibited in an experiment using 120 rats. The procedure used in 80 cancer patients was followed by favorable changes in the concentration of several hormones. The antinociceptive action of electrostimulation is similar to that of narcotic analgetics.

Growth of Pliss lymphosarcoma inoculated into rats was accompanied by development of amenia, whereas content of Schiff bases was increased and concentration of SH-groups was decreased in erythrocytes of peripheric blood. Alterations in content of lipid peroxidation products, especially the decrease of SH-groups, were detected before manifestations of the anemia indications registered under laboratory conditions. This suggests the importance of lipid peroxidation in elevated rate of erythrocyte hemolysis during tumor growth.

Animal experiments have shown that in the presence of tumor growth immunological stimuli can produce shifts in some reactivity characteristics of the affected organism, which are the reverse of the shifts occurring in a healthy organism under similar conditions. This is attributed to the fact that the immunological stimulus used in these experiments (complete Freund adjuvant) was excessively strong for the affected organism, thus causing the suppression of certain components of reactivity instead of their stimulation. This mechanism is supposed to induce the suppression of the ptocesses lying at the basis of enhanced tumor growth; nevertheless, this suppression is not considered to have a significant positive effect.

The (CBA X C57BL) F1 mice were injected intramuscularly with methylcholantrene (MCA) in a dose of 0.3 mg, and their T- and B-cells ability to cooperate in the immune response against sheep red blood cells, and also migration of these cells from the thymus and the bone marrow to the spleen were studied. The MCA immunosuppressive action proved to be associated with the inhibition of migration and cooperation of T- and B-lymphocytes in the immune response. A conclusion was drawn that the immunosuppressive effect developing during the carcinogenesis was complex and it was realized at various stages of immunogenesis.

In the cells of RS-1 carcinoma and those of Iensen's sarcoma it has been stated that acceleration and inhibition of tumor growth induced by nonspecific influence (vitamin A, hydrocortisone, proserin) are accompanied by uniform morphological changes of intracellular structures. Therefore, it is possible to suggest that the changes observed reflect a certain cell adaptation to the altering environmental conditions (cell stress-reaction). The cell stress-reaction is presented morphologically and hence, can by systematized. An attempt of such systematization is suggested.

The action of local laser-induced microvascular injury on the frequency of tumour-cell lodgement and on the ability of these cells to migrate out of the microvessel lumen was studied. Intravital TV-microscope with a videotape recorder and an ultra-voilet laser was used. Ascites Saidel hepatoma cells were injected into the blood stream of rats. Lodgement of tumour cells in the mesenteric vessels was observed but rarely (11%). The lodged cells adhered to the microvascular wall and gradually migrated from the lumen. The injury of the wall with laser beam results in the formation of microthrombi and in increase in the frequency of lodgement of the tumour cells in these vessels: 82% against 11%, but migration of these cells decreased. The data obtained supported the significance of the microthrombus formation in the metastatic process. However, this role is not one-sided since on the background of increased frequency of adhesion of the tumour cells there was noted a decrease in their motility in the course of several hours after the lodgement in the microvessels.

It is concluded that endolymphatic infusion of X-ray contrast substance in the presence of migrating tumor cells in lymphatic routes is inherent in a potential danger of tumor dissemination. Although getting of tumor cells in blood does not always result in metastases, nevertheless, a due account should be taken of the fact that lymphography is frequently performed in poor immunological resistance patients, preliminarily subjected to chemo- and radiotherapy. The decrease of immune resistance of the organism, in which the lymphatic system is of primary importance, is known to contribute per se to generalization of the tumor process. Another important conclusion is that the principal mass of tumor cells is ejected in the immediate period after endolymphatic injection of X-ray contrast substance. Thus, the cannulation of the thoracic duct during this period may prevent or reduce getting of massive amounts of tumor cells into the total blood flow.