[Molecular nature of regulating cell division and differentiation in an organism].

A short review of the investigations of contactins, tissue-specific compounds providing intercellular contacts, which were discovered by the authors in the 60s, is presented.

[The carcinogen urethane induces high-amplitudes circaseptan variations in target tissues and disrupts the rhythm of cell count in lymphoid organs].

The presence of tumor is accompanied by biological rhythms disturbance both in damaged (target) organ, and in nondamaged systems. As discoordination of biorhythms is sometimes one of the causes of pathologic states, we have investigated, which changes in system of about 7-day duration (circaseptan) biorhythms preceded the tumor appearance. The model of lung carcinogenesis, induced by single dose (0.

[The ultrastructure of the hepatocyte contacts in inbred mice at different ages].

Correlation was revealed between the ultrastructure of hepatocyte contacts and force F, essential for the rupture of the junction between the cell, seized with a microneedle, and the tissue specimen, in mice of the highly cancerous CBA line and of the low cancerous C57BL line at the age of 1.7 and 15 months. The most considerable ultrastructural differences in the cell contacts were found in the above mice at the age of 1 month, when the signs of carcinogenic process cannot yet been seen.

[Stability threshold of a tissue system].

Studies of changes in the cells adhesive force during spontaneous and induced cancerogenesis, as well as under the effect of cancerogenesis promotors permits to reveal the cells adhesion forces critical values which separate tissue states stable and unstable to blastomogenesis. These data are analysed proceeding from the concepts on generalized cooperative transitions in the membranes and their role in the control over biological systems. It is taken into account that the membranes and cytoskeleton elements are the most important systems of the tissue mechanical integration, and phase transitions proceeding in them must be reflected in the tissue mechanical properties.