Approaches to microclonal propagation of the rare medicinal plant Ungernia victoris both through the direct regeneration from the scale of bulb and via induction of regeneration from the longterm grown in vitro callus tissues have been developed for the first time ever. Conditions for multiplication and maintenance of in vitro generated microbulbregenerants were specified as well.

A study was made of the antimutagenic effect of natural lymphoblastoid interferon and alpha 2-recombinant interferon against initial damages to DNA induced by 8-methoxypsoralen, activated by UV-light, in human peripheral blood. The crosslinking and uncrosslinking 8-methoxypsoralen monoadducts were shown to make different contribution to the biological effects in cells, that is, chromosome aberrations and sister chromatid exchanges. Both of the investigated interferons exhibited their protective effect with respect to crosslinking monoadducts only. The antimutagenic action of interferon was implemented by a non-repair way. It is suggested that the scavenging of active radicals is a possible mechanism of the protective action of interferon.

In experiments with cultured V-79 Chinese hamster cells a study was made of the influence of dibunol on the level of gamma-radiation-induced micronuclei and sedimentation properties of cell nucleoids during ultracentrifugation in a neutral sucrose gradient. Protection of DNA molecule against the effects of both primary and secondary damages was found to be involved in the mechanism of the protective action of dibunol.