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Biomedical subjects

A D Virnik

Publications and source records attributed to A D Virnik.

35 records · Page 2Linked to original sources
PubMedDate not supplied

[Synthesis and study of the properties of water-insoluble products of the interaction of urease and cellulose derivatives].

As a result of reaction of urease with graft copolymer of cellulose and polyglycidyle methacrylate or with carboxymethyl cellulose, products were synthesized, containing about 2% of chemically bound urease. Binding with the cellulose derivatives was accompanied by about two-fold decrease in urease activity. Carboxymethyl cellulose-urease and polyglycidile methacrylate-cellulose-urease might be repeatedly (for 30 cycles) used for hydrolysis of urea; the enzymatic activity of the first compound did not change, but of the second one--was decreased by 30%. Activity of the compounds was not changed after storage within 2 months in 0.1 M phosphate buffer, pH 7.0 at 4 degrees C.

Acrylates↗
PubMedDate not supplied

[Antimicrobial x-ray contrast articles].

A procedure has been developed to prepare the radio-opaque polymer composition containing an antimicrobial substance that can be used in medicine. The findings of the antimicrobial activity of products made of the above composition are presented in the paper.

Anti-Infective Agents, Local↗
PubMedDate not supplied

[Properties of urease immobilized by chemical binding to a derivatives of cellulose].

A comparative study of properties of soluble urease and urease immobilized by its binding to cellulose derivatives was carried out. Upon chemical binding of urease to cellulose derivatives the Mikhaelis constant and pH optimum for the enzyme action changed insignificantly. Maximum enzymic activity of soluble and immobilized urease occurred at 50 degrees C. The energy of activation of urea hydrolysis by urease during enzyme immobilization also changed insignificantly.

Catalysis↗
PubMedDate not supplied

[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. The porous structure of triacetate cellulose fibres with entrapped penicillin amidase was studied, the fibres being produced by different methods. An increase of porosity and the specific surface of the fibre-biocatalyst reduced the Km value and the energy of activation of the hydrolytic decomposing of benzyl penicillin but increased the Vmax value.

Enzymes, Immobilized↗
PubMedDate not supplied

[Preparation of films and fibers containing proteolytic enzymes].

Immobilization of the proteolytic enzymes trypsin and terrylitin in fluorplastic-42 films and fibers as well as in water-soluble polymeric (polyvinyl alcohol and carboxymethyl cellulose) films was being studied during preparation of the films. The properties of the proteolytic enzymes immobilized in the polymers are dependent on the conditions of preparation of fibers and films.

Enzymes, Immobilized↗
PubMedDate not supplied

[Experimental and clinical use of various forms of immobilized proteinases and their inhibitors].

Analysis of the data obtained in experimental (971 animals) and clinical (250 patients) studies with various immobilized proteinases and their inhibitors showed that this approach to enzymotherapy is a perspective one. Immobilized enzymes and inhibitors exceeded distinctly the native preparations in therapeutic efficiency and were devoid of their disadvantages (low stability and autolysis of proteinases, inactivation by inhibitors, occurring in blood and tissues, rapid elimination of the inhibitors from the organism). Wide use of immobilized enzymes and inhibitors in medical practice offered new possibilities in surgery, shortened distinctly the duration of patients treatment and enabled to decrease the doses of drugs and consumption of dressing materials.

Acute Disease↗
PubMedDate not supplied

[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.

Animals↗
PubMedDate not supplied

[Preparation of fiber materials containing both the immobilized proteolytic enzyme and antimicrobial substance, and study of their properties].

Properties of joint immobilization of a proteolytic enzyme (terrilytin, trypsin, collytin, or protease C) and an anti-microbe compound to cellulose copolymer containing carboxyl groups were investigated. It was established that the molecule of anti-microbe substance containing a few base groups enhanced stability of the enzyme immobilized, most likely due to additional fixation of the enzyme macromolecule. Changes in activity of the materials containing both protease and anti-microbe compound were studied upon gamma-sterilization and subsequent prolonged storage. The materials with combined biological action were demonstrated to accelerate markedly wound cleansing and healing.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Preparation of films with combined biological activity and study of their properties].

Joint immobilization of a proteolytic enzyme (terrilytin, protease C, or collytin) and an antimicrobial compound or the bacteriolytic enzyme lysozyme in the structure of polyvinyl alcohol was studied. Changes in the activity of immobilized enzymes upon x-ray sterilization were studied. These materials were highly effective in wound healing.

Amylases↗