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Biomedical subjects

A D Virnik

Publications and source records attributed to A D Virnik.

At least 19 recordsLinked to original sources
PubMed1988

[Preparation of porous material based on alginic acid, containing immobilized terrilytin].

A comparative study was conducted on immobilization of terrilytin on alginic acid by attaching the enzyme by ionic or covalent bonds and possible use of such compounds in preparing porous coatings for wound treatment. It was shown possible to prepare a coating with the enzyme activity after radiation sterilization equal to 80-85 per cent of the initial level. Medico-biological investigations proved that the use of the coating in treatment of purulent wounds was efficient.

Alginates↗
PubMed1980

[Immobilization of modified alpha-chymotrypsin within the structure of cellulose triacetate membranes].

Immobilization of alpha-chymotrypsin on carboxymethyl esters of dextran (mol. weights of 60 000 and 100 000), whose macromolecules contain 2-amino-4-chloro-s-triazine residues, results in water-soluble polymeric derivatives of alpha-chymotrypsin, containing up to 60% of the enzyme. The activity of the immobilized enzyme makes up to 90% of the initial one. Using dextran blue as a matrix, a polymeric derivative of alpha-chymotrypsin, containing 9% of a chemically bound enzyme, which retains 20% of its initial activity, has been obtained in a similar way. The thermal stability of the enzyme increases during alpha-chymotrypsin linking to carmoxymethyl esters of dextran. The incorporation of alpha-chymotrypsin into the triacetate cellulose membrane (CTA) during its formation results in a practically complete desorption of the enzyme from the membrane into 1 M NaCl. During incorporation of alpha-chymotrypsin linked to the carboxymethyl ester of dextran (mol. weight 60 000) into the CTA membrane the bulk of the modified enzyme is desorbed, whereas in the case of alpha-chymotrypsin linked to the carboxymethyl ester of dextran with mol. weight of 100 000 or to the blue dextran only an insignificant part of the enzyme is desorbed. The thermal stability of alpha-chymotrypsin and the labile form of the enzyme linked to the carboxymethyl ester of dextran with mol. weight of 100 000 increases during the enzyme incorporation into the CTA membrane.

Cellulose↗
PubMed1977

[E. coli penicillin amidase. Physico-chemical properties of the enzyme covalently bound to the 2-(3'-amino-4'-methoxyphenyl)-sulfonylethyl ester of cellulose].

The effect of the procedure of the enzyme binding with the carrier on the properties of the heterogenous catalyst obtained by covalent binding of penicillinamidase (PA) with cellulose 2-(3'-amino-4'-methoxyphenyl)-sulphonylethyl ether by means of the bifunctional reagent, i.e. glutaric aldehyde was studied. It was shown that the amount of the bound enzyme increased with a rise in the amount of the enzyme taken for the binding, while the binding efficiency characterizing the part of the active enzyme in the total amount of the bound PA decreased practically 2 times. The use of the enzyme preparations with different purify levels for the binding provided differentiation of the effects resulting in the activity loss on immobilization. In other words it provided separate estimation of the inactivation effect of the matrix and the immobilization procedure, as well as the interaction of the enzyme molecules with each other and other protein molecules.

Amidohydrolases↗
PubMed1977

[Modification of the properties of drugs combined with polymers. II].

In the second part of the paper there have been discussed the works on modification of drugs properties when coupled with polymers in terms of covalent links. It was proved on a number of cases that chemical bonds of specified drugs and polymers allows to increase the durability and effective action of these remedies, to decrease the toxicity, to increase the solubility and immunity against ferments and, moreover, enable the advantageous disposal of these substances in particular organs.

Chemical Phenomena↗
PubMed1976

[Modification of properties of drugs combined with polymers. I].

The article reviews the papers on modifying the properties of drugs by their administration in the form of a mixture with polymers, or combination of the drugs and polymers using coordinative or ionic bonds. In many cases the combination of drugs and polymers by chemical means or preparation of a mixture of drugs and polymers prolongs and increases the effectivity of drugs, increases their solubility, decreases their toxicity, and modifies their distribution in the organs.

Anti-Bacterial Agents↗
PubMed1975

[Study of the antibacterial activity of ftorlon threads].

The study concerned antibacterial properties of the ftorlon threads obtained from acetone or dimethylformamide polymer solution containing antibacterial derivatives of 5-nitrofuran added which were known to be active against the germs most commonly causing the postoperative infection including Staphylococci, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris and Candida type fungi. Basing of the laboratory test following the method of infected medium and suspension method it was found that the best effects were obtained when using threads produced from the acetone polymer solution added with beta-(5-nitrofuryl-2)-acroleine and those containing furazolidone obtained from acetone or dimethylformamide polymer solution. Antibacterial properties of the ftorlon threads did not change upon autoclaving, gamma irradiation and prolonged storage.

Candidiasis↗
PubMed1975

[Properties of penicillin amidase covalently bound to cellulose matrices].

Properties of penicillinamidase (PA) covalently bound with the cellulose matrix were studied. The efficiency of the binding depended on the bind type and purity of the native enzyme taken for binding. Stability of the immobilized PA (IPA) was studied at wide pH ranges. The effect of the ion strength, substrate concentration and purity of the native PA on stability of IPA was also investigated. The maximum stability of the enzyme was observed at pH 6.5-7.0 Stability of IPA depended on the purity of the native enzyme. When PA of the diazotized ether of cellulose containing amino groups was used, the enzyme was destabilized. IPA prepared on chlortriazinylcellulose was more stable than the respective native PA almost by I order.

Amidohydrolases↗