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Biomedical subjects

K Worowski

Publications and source records attributed to K Worowski.

At least 73 records · Page 4Linked to original sources
PubMed1980

Thromboplastic and fibrinolytic activity of autogenous-free vein grafts used as abdominal aorta replacements in dogs.

In the intima of a vein grafted into the aorta, the thromboplastic activity during the first 4 months after the operations is higher than in the artery and vein. At the same time, the plasminogen activator activity of the venous graft is also higher than that of the artery but lower than that of the vein. In the later post-operative period, both activities of the intima of the venous graft closely approaches those of the intima of the normal vein. In the media the thromboplastic activity is lower in the graft and the plasminogen activator content is higher than in the artery and vein. However, the thromboplastic and fibrinolytic activity in the adventitia of the venous graft, artery, and vein did not change significantly during the 36-month observation period of the experiment.

Animals↗
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

Effect of potato protease inhibitor on the clotting system and fibrinolysis in the dog.

The potato inhibitor of proteolytic enzymes was found to inhibit the plasma clotting and fibrinolytic systems in the dog. The anticoagulative action of potato inhibitor consists in a prolongation of clotting time, inhibition of thromboplastin generation, reduction of prothrombin consumption and of the retractility of the blood clot. The potato inhibitor prolongs the euglobulin fibrinolysis time and causes a rise in the plasma antiplasmin level.

Animals↗