Layer Specific Development of Neocortical Pyramidal to Fast Spiking Cell Synapses.

All cortical neurons are engaged in inhibitory feedback loops which ensure excitation-inhibition balance and are key elements for the development of coherent network activity. The resulting network patterns are strongly dependent on the strength and dynamic properties of these excitatory-inhibitory loops which show pronounced regional and developmental diversity. Therefore we compared the properties and postnatal maturation of two different synapses between rat neocortical pyramidal cells (layer 2/3 and layer 5, respectively) and fast spiking (FS) interneurons in the corresponding layer.

Distribution and resorption of polymeric microparticles in visceral organs of laboratory animals after intravenous injection.

Microparticles obtained by using (14)C-labeled resorbable hydroxyaminobutyric acid polymer were injected into the caudal vein of laboratory animals without negative aftereffects for their growth and development and without changes in the macro- and microstructure of organs and tissues. The distribution of microparticles in the viscera and the dynamics of accumulation of carbon-containing polymer degradation products in the viscera were studied. The main targets for the particles are liver tissues, as well as renal and splenic tissues.

[Microbial polymers as a degradable carrier for pesticide delivery].

The possibility of use of polyhydroxyalkanoates (PHAs), biodegradable microbial polyesters, as a carrier for pesticides (alpha-hexachlorocyclohexane and lindane) for targeted and controlled delivery of these compounds to soil was investigated. The kinetics of polymer degradation and the dynamics of pesticide release from the extended-release formulations was studied. It is shown that pesticides embedded in a degradable polymer (PHA) carrier are released gradually and slowly, without surges, as the polymer is degraded by the soil microflora.

Evaluation of antitumor activity of rubomycin deposited in absorbable polymeric microparticles.

An experimental dosage form of rubomycin is developed: the drug is incorporated in absorbable polymeric (polyhydroxybutyrate) matrix in the form of microparticles. Antitumor efficiency of this rubomycin dosage form was studied in laboratory mice with transplanted Ehrlich ascitic carcinoma. Rubomycin deposited in polymeric microparticles exhibited pronounced antitumor activity, inhibited the proliferative activity of Ehrlich ascitic carcinoma, and improved survival of mice with tumors.

Tissue reaction to intramuscular injection of resorbable polymer microparticles.

Tissue reaction to implantation of polymeric microparticles from resorbable polymer (polyhydroxybutyrate) is characterized by slight inflammatory reaction and pronounced progressive macrophage infiltration with the presence of mono- and multinuclear foreign body giant cells resorbing the polymeric matrix. No fibrous capsules were formed around the polymeric microparticles; neither necrosis nor other adverse morphological changes and tissue transformation in response to implantation of the PHB microparticles were recorded. The results indicate good prospects of using polyhydroxybutyrate for the construction of long-acting dosage forms as microparticles for intramuscular injection.