[Effect of metal ions on Escherichia coli NAT 99-50R penicillin acylase production].

The processes of growing E. coli NAT 99-50R in a synthetic nutrient medium containing metal salts (iron nitrate, lutecium nitrate or cerium nitrate) were carried out. As shown in experiments, the addition of metal salts at different concentrations into the medium produced different impact on the penicillinase activity of the culture.

[A comparison of the yield of Vi and O antigens during the adaptation of Salmonella typhi strains to cultivation under starvation conditions].

S. typhi strains Ty(2)4446 and Vi-1S underwent multiple passages in f synthetic liquid starvation culture medium consisting of water with salts and glucose added. In the process of the adaptation of the cultures to these stress conditions (starvation stress) the increasing yield of biomass from passage to passage was observed.

[A comparative study of the action of preparations of high- and low-molecular weight heparin on hemostatic indices in vitro and in their intravenous administration to animals].

Low-molecular heparin preparations (a Soviet sample and that manufactured by the Celsus Company) in vitro, added to bovine plasma possess a lower antifactor-II activity, less time of recalcification and partial thromboplastin time as compared to high-molecular heparin of equal concentration (mg/ml) or dose (Units/ml). After intravenous injection of low-molecular heparin preparations to animals in a dose of 50 Units/200 g bw the time of hemorrhage was far less, while anticoagulant activity was lower than in animals given the same dose of high-molecular heparin. Both injection of low-molecular and high-molecular heparin results in a rise of the intensity of non-enzymatic fibrinolysis in the animals' blood plasma.

[A comparative study of the cryoprotective properties of dimethylacetamide and dimethyl sulfoxide in preserving thrombocytes at moderately low temperatures].

Comparative characteristics of cryoprotective properties of dimethylacetamide and dimethyl sulfoxide (DMAC and DMSO, respectively), used for freezing and storage of platelets at -80 degrees C, have been presented. It is shown that with the studied final concentrations of the cryoprotectors (5% of DMSO, 2.5% of DMAC), solutions containing DMSO display higher cryoprotective properties.