[Effect of metal ions on Escherichia coli NAT 99-50R penicillin acylase production]. / Vliianie ionov metallov na produktsiiu penitsillinatsilazy Escherichia coli NAT 99-50R.

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. This activity increased 7- to 10-fold when the bacteria were grown in a synthetic medium with iron nitrate added at a concentration of 0.0001% or with lutecium nitrate added at a concentration of 0.01%.

[A comparison of the yield of Vi and O antigens during the adaptation of Salmonella typhi strains to cultivation under starvation conditions]. / Sravnenie vykhoda Vi- i O-antigenov v protsesse adaptatsii shtammov Salmonella typhi k kul'tivirovaniiu v usloviiakh golodaniia.

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. Differences in the accumulation of Vi- and O-antigens were noted in two strains under study. In the cultures of strain Ty(2)4446 an insignificant increase in the antigen content from passage to passage was observed, while in the cultures of strain Vi-1S an increase in the content of Vi- and O-antigens was 4- to 5-fold. With the adaptation of the culture the Vi-antigen to O-antigen ratio changed from 1:57 to 1:20 for strain Ty(2)4446 and from 1:2.7 tp 1:2.2 for strain Vi-1S. Strain Ty(2)4446 had an advantage over strain Vi-1S with respect to the synthesis of Vi-antigen. These data are indicative of the expediency of using not only strain Ty(2)4446, but also strain Vi-1S for the preparation of typhoid vaccine, especially the one based on Vi-antigen.

[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]. / Sravnitel'noe izuchenie deistviia preparatov vysoko- i nizkomolekuliarnogo geparina na nekotorye pokazateli gemostaza in vitro i pri vnutrivennom vvedenii zhivotnym.

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]. / Sravnitel'noe izuchenie krioprotektornykh svoistv dimetilatsetamida i dimetilsul'foksida pri khranenii trombotsitov v usloviiakh umerenno nizkikh temperaturakh.

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. Positive effect of autoplasma in the mixture with the platelet-protecting solution has been manifest in the maintaining of the functional properties of platelets after defrosting.