[Dynamics of bacterial population waves in relation to the function of chemotaxis response].

The time of formation and rate of bacterial population waves as a function of substrate concentration has been investigated. It was shown both theoretically and in experiment that the time of wave formation increases with substrate concentration. At the same time, the rate of wave propagation decreases at relatively high substrate concentrations.

[Orange-red light reduces the inhibition by UV-A of the proliferation of rat fibroblasts and influences their attachment in a dose-dependent fashion].

The effects of ultraviolet-A (UV-A, lambdam = 365 nm) and orange-red light (lambdam = 625 nm) on the attachment and proliferation of embryonic skin-muscle rat fibroblasts were investigated. It was found that orange-red light (ORL) produces both the stimulatory and inhibitory actions on the attachment and proliferation of fibroblasts, whereas UV-A radiation caused only the inhibition of the processes. Upon consecutive irradiation in both variants: ORL --> UV and UV --> ORL, the synergistic effect of the inhibitory action in both spectral regions was observed.

Prevention of experimental autoimmune encephalomyelitis in DA rats by grafting primary skin fibroblasts engineered to express transforming growth factor-beta1.

To determine whether primary fibroblasts producing latent transforming growth factor beta1 (TGF-beta1) are capable of down-regulating experimental autoimmune encephalomyelitis (EAE), a retroviral vector TGF-beta1-pBabe-neo (-5'UTR) was used for efficient gene transfer into primary skin fibroblasts of DA rats. After heat activation, conditioned medium from the transduced fibroblasts was found to inhibit significantly in vitro proliferation of lymphocytes from lymph nodes of DA rats with EAE. Intraperitoneal administration of TGF-beta1-transduced fibroblasts into DA rats during the priming phase of EAE resulted in a significant reduction in mortality and in the mean clinical and EAE scores versus the control immunized animals treated with non-transduced fibroblasts.

[Selective cytostatic and cytotoxic effects of avermectins].

A natural avermectin complex, aversectin C, was shown to be capable of exerting selective cytostatic effect. It killed proliferating neuroblastoma B 103 cells but was non-toxic for differentiated cells of this culture. The activity of aversectin C was related neither to activation of the GABA alpha-receptors nor to their blocking and was at a large extent due to the action of avermectin A1, a component of aversectin C.