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Biomedical subjects

T Astrup

Publications and source records attributed to T Astrup.

At least 37 records · Page 2Linked to original sources
PubMed1980

The fibrinolytic response in injured animal tissues normally low in fibrinolytic activity.

Rabbit skin, normally of low fibrinolytic activity, and guinea-pig skin, of medium activity, after crush injury or after the intradermal or subcutaneous injection of aluminum hydroxide, show a remarkable increase in fibrinolytic activity. The activity is caused by a plasminogen activator and is related to blood vessels. Occasionally, intense fibrinolytic activity was also observed in some specimens collected from various other organs normally low in activity. Thus two specimens of rabbit aorta, one specimen of rabbit trachea and one specimen of rabbit stomach showed increased activity related to pathological processes. One specimen of guinea-pig rectum showed intense fibrinolytic activity along the serosa.

Animals↗
PubMed1980

Effects of dextran sulphate and flufenamic acid on euglobulin fibrinolytic activity of glass-treated or heated plasma.

Treatment of human citrated plasma with glass has complex effects on the fibrinolytic system. While the spontaneous euglobulin activity is only slightly affected by the glass treatment, the activity precipitated in the presence of dextran sulphate diminishes rapidly with increasing amounts of glass. With common glass a minimum is reached, and the activity reappears when larger amounts of glass are used. With Pyrex glass the decrease continues. Addition of flufenamate to the solutions recover much of the missing activity suggesting the presence in the euglobulin precipitates of an inhibitor sensitive to flufenamic acid. Heating of plasma at 56 degrees C rapidly destroys its ability to produce spontaneously active euglobulin precipitates while the capacity to elicit fibrinolytic activity by precipitation in the presence of dextran sulphate remains largely undisturbed suggesting a relative stability of the precursors of the intrinsic fibrinolytic system.

Dextran Sulfate↗
PubMed1978

Patterns of activation and inhibition of fibrinolysis in the normal skin of rat, guinea pig, and rabbit.

The distribution and intensity of fibrinolytic activity and of inhibitors of fibrinolysis in the normal skin of the rat, guinea pig and rabbit were studied with histochemical techniques. Rat skin exhibited the highest overall fibrinolytic activity and rabbit skin the lowest, with guinea-pig intermediate. The distribution of fibrinolytic areas differed in the different species. The fibrinolytic activity was caused by an activator of plasminogen related to the blood vessels or in some instances (mainly in the rabbit) to the epidermis. The ability to inhibit plasmin was highest in guinea pig skin and lowest in rat skin, with rabbit skin intermediate. In all 3 species the inhibition was related chiefly to the muscular layer. Epidermis was an additional source of inhibition.

Animals↗
PubMed1978

Localization of fibrinolytic activity and inhibition of plasmin in the spinal cord of rat, guinea pig, and rabbit.

Fibrinolytic activity (caused by a plasminogen activator) in the spinal cord was highest in the rat, lowest in the rabbit, and intermediate in the guinea pig; In all species the activity was highest in relation to the pia mater. The central spinal canal was active in the rat and the rabbit, but mostly inactive in the guinea pig. Foci of activity were more numerous in the gray matter than in the white matter corresponding to the greater vascularity of the former. In all species ability to inhibit plasmin was related mainly to the gray matter, with an additional area related to the dura mater. The high fibrinolytic activity of the spinal leptomeninges may play a role in the pathogenesis of hemorrhagic processes related to the spinal cord.

Animals↗
PubMed1977

A histochemical study of fibrinolytic activity and inhibition of plasmin in the lungs of some animal species.

Determined by the histochemical fibrin slide technique, the fibrinolytic activity of lungs decreased in the following order of species: rat, mouse, pig, guinea pig, rabbit, cattle. Examined by the fibrin slide 'sandwich' technique, inhibition of plasmin showed the opposite mode of decrease. The possible role of these differences in the pathogenesis of various disorders of the lungs in the different species is discussed.

Animals↗
PubMed1976

Differences in the reactivities of human urokinase and the porcine tissue plasminogen activator.

It has previously been shown, that large differences exist between the effects of 6-aminohexanoic acid or alpha1-antitrypsin on fibrinolysis caused by a porcine tissue plasminogen activator or by human urokinase, while insignificant differences exist between the effects of a number of natural protease inhibitors on fibrinolysis caused by the two types of plasminogen activator. The present study shows that changes in substrate composition (pH, ionic strength fibrinogen concentration, plasminogen concentration) may influence to different degrees the fibrinolytic activities of human urokinase and the porcine tissue plasminogen activator. It is suggested, that this finding is partly related to marked differences in affinity for fibrin of the two activators.

Animals↗
PubMed1975

Localization of tissue plasminogen activator in relation to morphologic changes in human saphenous veins used as coronary artery bypass autografts.

Employing the histochemical fibrin slide technique, we studied the localization of fibrinolytically active sites in relation to morphologic changes in saphenous veins used as coronary artery bypass autografts. Of veins from 100 patients undergoing surgery for coronary heart disease, 63 samples revealed well-demarcated intimal fibrinolytic activity. Distinct foci of lysis were present in the media and adventitia of all vein samples corresponding to the distribution of the vasa vasorum. Graft specimens obtained by autopsy from 13 patients surviving from 30 minutes to 13 days revealed considerable intimal damage with loss of fibrinolytic activity. Medial fibrinolytic activity disappeared early concomitant with disorganization of the medial muscle fibers, followed by necrosis, atrophy and fibrous transformation of the muscular structures. Adventitial activity disappeared later. One reoperation sample obtained after 8 weeks in situ showed moderate proliferative intimal fibrosis without an apparent neo-intima and without fibrinolytic activity, and one section showed evidence of valve cusp fibrosis, while most of the media had been replaced by fibrous tissue. Numerous foci of "medial" -adventitial fibrinolytic activity indicated presence of vascular structures in the venous wall. The fibrin slide technique is a convenient tool for studying the process of revascularization.

Atrophy↗