[Rational organization of the technological processes of hydrolyzing whey lactose in the presence of a heterogeneous fiber biocatalyzer].

We have studied lactose hydrolysis in whey in the presence of a fibrous biocatalyst containing immobilized beta-galactosidase in a continuous-flow column reactor, and in a reactor unit with substrate recycling in batch and continuous regimes. The comparative study of the efficiency of the reactors allowed us to recommend the reactor unit with substrate recycling for lactose hydrolysis in whey in the batch regime, since it provides both satisfactory hydrodynamic stability and high productivity.

[An experimental study of biomaterials resistant to calcinosis and thrombosis].

Creation of hemocompatible materials resistant to calcinosis for plastic cardiosurgery call for employment of combined methods of their evaluation in experiment. The present study deals with some biochemical and physico-chemical aspects of biomaterial calcification inhibition on reduction of their porosity by means of N-vinylpyrrolidone, and also on immobilization of diphosphonates, phosphonates, and anti-aggregants. The method of radiation copolymerization was employed for immobilization of active agents.

[Resistance of heart valve bioprosthesis to the proteolytic effect of collagenase and elastase].

Proteolytic destruction of pig aortal valves was studied at various steps of their preparation to implantation (native tissue, the tissue treated with terrylytine as well as with terrylytine and glutaric aldehyde) using pig pancreatic elastase and bacterial collagenase. The rate of the tissue destruction was estimated by means of monitoring an increase in content of protein and amino nitrogen in the hydrolysates. The tissue treated with terrylytine and glutaricaldehyde was 10-40-fold more resistant to proteolysis as compared with native heart valve tissue.

[Effect of the structure of polymeric materials on the properties of immobilized enzymes].

The relationship between the structure of triacetate cellulose fibres and films and properties of enzymes entrapped in these materials was investigated. Trypsin and penicillin amidase were entrapped in triacetate cellulose films and fibres during their formation. The effect of permeability of the films on the catalytic properties of entrapped trypsin was studied.

[Second set method for determining the immunogenicity of heart valves].

The "second set" method was used on inbred rats to study immunogenicity of the heart valves treated with a proteolytic enzyme and glutaric aldehyde and to compare it with immunogenicity of the valves treated with glutaric aldehyde alone according to Hancock's method. The valves treated by the enzyme and 0.2-0.