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Biomedical subjects

K Worowski

Publications and source records attributed to K Worowski.

At least 19 recordsLinked to original sources
PubMed1979

Cathepsin D activity of venous and polyester vascular grafts implanted in the abdominal aorta of the dog.

Autogenous veins and polyester prostheses were implanted in the abdominal aorta of dogs. The venous or polyester grafts were removed together with sections of the normal arteries and veins 1 month, 4 months, and 3 years after the operation. This material was then dissected into the intimal, medial, and adventitial layers, and homogenized after which their cathepsin D activity was determined. It was found that the cathepsin D activity was far higher in all the layers of the venous grafts, particularly in the polyester grafts, than in the corresponding layers of the normal arteries and veins.

Animals↗
PubMed1979

Distribution and variation of thromboplastic and fibrinolytic activity of dacron aortic grafts.

The distribution and variation of thromboplastic and fibrinolytic activity were studied in various layers of polyester grafts in the dog aorta. One, four and 36 months after implantation, these grafts were removed together with segments of normal arteries and veins and dissected into three layers. The thromboplastic and plasminogen activator activities in these layers were then determined. It was found that in the early post-operative period, the thromboplastic activity in the Dacron graft neointima is very high, whereas that of the plasminogen activator is relatively low. With the passage of time the thromboplastic activity decreases and plasminogen activator activity increases. Similarly the thromboplastic activity in the neomedial and neoadventitial layers of the graft falls as time elapses after the implantation and the fibrinolytic activity gradually increases. These changes in thromboplastic and fibrinolytic activity increase the danger of graft thrombosis in the early post-operative period whereas in the later period they are favourable to maintenance of graft patency.

Animals↗
PubMed1979

[Histone-heparin complexes].

Histones form insoluble complexes with heparin and neutralize its anticoagulant action. The plasmin degradation products of histones do not possess these properties. Plasmin also digests histones in complexes with heparin. Breakdown of the histones in these complexes causes release of heparin from them.

Animals↗
PubMed1978

Degradation of low-density lipoproteins (LDL) and LDL - protamine complexes by lysosomal protease.

Native LDL are degraded by the protease of the lysosomal extract but they are not sensitive to isolated cathepsin D. Protamine increases the sensitivity of LDL to the effect of lysosomal protease and makes them sensitive to the effect of cathepsin D. Degradation of LDL by lysosomal protease is most intensive between pH 4.0 and 4.5 but in case of LDL bound with protamine it is most intensive at pH 4.5--5.0.

Cathepsins↗
PubMed1977

Local activation of blood coagulation by polyester prostheses implanted into defects of the abdominal aorta of dogs.

An 8 cm long Dallon prosthesis was implanted into defects of the abdominal aorta of dogs, and the following changes were found: the blood flow through the vascular prosthesis induced a shortening of the blood clotting time and the heparin-thrombin time and a slight increase in the prothrombin consumption. It has a favourable effect of the sealing of pores in the prosthesis and covering its internal surface with a fibrin membrane.

Animals↗
PubMed1976

Synergistic antifibrinolytic action of the potato protease inhibitor and epsilon-aminocaproic acid.

Fibrinolysis inhibition by a mixture of potato inhibitor and E-aminocaproic acid was greater than might be expected from the sum of the antifibrinolytic effects of these inhibitors investigated separately. This inhibition was observed in studies on the plasma euglobulin fraction and in a system containing isolated elements of the fibrinolytic system. The synergistic antifibrinolytic action of the potato protease in hibitor and E-aminocaproic acid is probably due to the fact that these inhibitors have different mechanisms of action and thus there is no competition between them for the effectors in the enzyme molecule.

Aminocaproates↗
PubMed1975

Enzymatic degradation of protein mixtures.

The rate of protein enzymatic degradation in a mixture is slower than that of single proteins. In a mixture of haemoglobin or casein with protamine, the release of tyrosine by trypsin and chymotrypsin A is slower. A slower rate in the release of arginine from protamine occurs only in mixtures with haemoglobin. The inhibition of enzymatic degradation of proteins in a mixture is due to formation of intermolecular associations and to changes in their spacial structure.

Arginine↗
PubMedDate not supplied

[Properties of protamine-heparin complexes].

Protamine-heparin complexes have a considerable resistance to physical factors of the environment such as a high ion strength and acid or alkaline pH. Free protamine is digested by plasmin giving products with a greatly decreased ability to form complexes with heparin and lower antiheparin action. Bound protamine, on the other hand, is resistant to the action of plasmin as a result of which the enzyme does not release heparin from the complexes.

Fibrinolysin↗