[Selective adhesion of tumor cells to the endothelium of the target organ in metastasis]. / Izbiratel'naia adgeziia opukholevykh kletok k éndoteliiu organa-misheni pri metastazirovanii.

The fragments of cell plasma membranes of two lines of metastatic tumour of A/He mice (lung adenocarcinoma--LA-cells and hepatoma HA-1--HA-cells) were used to prepare "hybrid" vesicles (LA- and HA-liposomes). Incorporation of the fragments of LA-cells into the bilayer vesicle increased the binding of LA-liposomes with lung almost by an order of magnitude, their trapping by liver being noticeably decreased. HA-liposomes were retained in the liver in larger amounts than the model phospholipid liposomes. It is assumed that the specificity of metastatic spreading into an organ is associated with the interaction of the plasma membrane of the tumour cells with the apical membrane of the target organ endothelium.

[Interaction of the plasma membranes of the cells of tumors metastasizing to the lungs with the target organ]. / Vzaimodeistvie plazmaticheskikh membran kletok opukholei, metastaziruiushchikh v legkie, s organom-mishen'iu.

Cells of lines of mice transplantable tumours metastasizing into the lung have been used: lung adenocarcinoma (AL), Lewis lung carcinoma (LL), melanoma B-16 (B-16), mammary tumour MMT-1 (MMT-1), malignant subline of L-cells (LS). Hybrid vesicles were obtained for each tumour. They contain fragments of cell plasmatic membranes (PM). It has been shown that AL-, LL-, LS- and B-16-liposomes were accumulated in lung, the trapping of AL- and LL-liposomes being higher than that of the other hybrid vesicles. Despite the similar dynamics and frequency of metastatic spreading into the lung for all tumours studied, no trapping of MMT-1-vesicles in the target-organ was observed. The role of specific interaction of tumour cells PM with the endothelium of the lung capillaries in the process of organotropic metastatic spreading is discussed.

[Modeling of myocardial pathology in mice with the surgical methods]. / Modelirovanie patologii miokarda u myshei operativnymi metodami.

A description of three operations on the heart in mice is presented: a supravalvular narrowing of the ascending aorta, banding of the apex of the heart, and ligation of the coronaries. These surgical interventions permit to obtain in mice a functional overloading and hypertrophy of the myocardium, a cardiac aneurysm and occlusive myocardial infarction.

Production of experimental occlusive myocardial infarction in mice.

A method is described for production of occlusive myocardial infarction in mice. The dynamics of development as well as the morphological changes in ischaemized myocardium of mice, large laboratory animals, and humans were identical. Polarization microscopy helped reveal myocardiocytic changes in the ischaemic zone already within the first minutes after coronary artery ligation. The method reported upon has the following advantages: feasibility of all stages of the operation by a single operator, low postoperative mortality of the animals and their modest requirements for postoperative care, and low consumption of isotopes and costly therapeutic remedies.

Inhibition of tumor growth in mice treated with synthetic muramyl dipeptide.

Treatment with synthetic MDP inhibited growth of transplantable, chemically induced tumors in syngeneic mice. The tumor-inhibitory effect was dependent on the schedule of MDP administration. Growth of SC transplants of a nonmetastasizing, MC-induced fibrosarcoma, MC11, was inhibited by local treatment with 200 micrograms and 1,000 micrograms MDP given SC 5-7 weeks before challenge. Treatment with lower (10 micrograms and 100 micrograms) doses of MDP and shorter (1-4 weeks) time intervals was not effective. Single doses of MDP (10-1,000 micrograms) 1-3 weeks after challenge had no effect. Growth of IV-inoculated, metastasizing AAT-induced hepatoma A was inhibited by IV injections of 20 micrograms MDP given 1 and 2 days prior to the challenge. Significant increases in the survival of hepatoma-bearing mice were observed only after injections of MDP incorporated in multilamellar liposomes.