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Biomedical subjects

U Abildgaard

Publications and source records attributed to U Abildgaard.

At least 181 records · Page 10Linked to original sources
PubMed1978

Antithrombin III: critical review of assay methods. Significance of variations in health and disease.

Thrombin or factor Xa added to plasma are inactivated by antithrombin III (At-III). The inactivation is accelerated by heparin, permitting assay systems which rapidly measure the At-III content of diluted plasma. Without heparin, the slow inactivation rates may be measured. Existing activity assays (fibrinogen or chromogenic substrates) and immunoassays of At-III have been reviewed. Correlation studies show a close correlation between the results of immunoassay and the results of most activity assays. In health, a narrow range of At-III has been found. The level is low in infancy. Fertile women have on the average somewhat lower levels than men. In old age, the level tends to drop. In clinical material studied with amidolytic assays, subnormal At-III levels were found in hereditary deficiency, liver disease, disseminated intravascular coagulation and in some cases with acute thrombosis. The amidolytic assays are rapid to perform, do not require experience in clotting technique and seem preferable in clinical routine work.

Acute Disease↗
PubMed1977

Antifactor Xa activity in thrombophilia. Studies in a family with Ar-III deficiency.

Antithrombin III (At-III) concentration and amidolytic assays reflecting functions of the At-III molecule were studied in members of a family with a strong tendency to thrombosis. Antifactor Xa and heparin cofactor activity closely parallel at At-III concentration. In all individuals with a history of thrombosis At-III concentration was about 50% of normal. The clinical features and causes of death are briefly reviewed. Mean age in deceased family members with a tendency to thrombosis was 55 years, in members with no history of thrombosis it was 65 years.

Adult↗
PubMed1976

On the value of the activated partial thrombo-plastin time (aptt) in monitoring heparin therapy.

Of 1068 blood samples referred for evaluation of the haemostatic mechanism 135 contained heparin as judged by the polybrene titration method. Of the 57 samples with a heparin concentration in the defined therapeutic range, 65 per cent had APTT values in the "therapeutic range". Of the samples from patients who had not received any anticoagulant, 213 (24 per cent) had prolonged APTT, and 48 of these samples had APTT values in the "therapeutic range" for heparin therapy. It is suggested that the APTT test is of limited value in monitoring heparin therapy.

Blood Coagulation Tests↗
PubMed1976

The effect of antithrombin III on the activity of the coagulation factors VII, IX and X.

Antithrombin III, purified to homogeneity according to polyacrylamide gel disc electrophoresis and immunoelectrophoresis, inhibited the activity of purified factor IXa and Xa, whereas factor VII was not inhibited either in the active or in the native form. Antithrombin III is the single most important inhibitor of factor Xa in plasma. Factor Xa does not, however, reduce the activity of antithrombin III against thrombin.

Antithrombins↗
PubMed1976

Antifactor Xa activity measured with amidolytic methods.

Methods for the assay of antifactor Xa activity in the presence and absence of heparin are described. Diluted plasma is incubated with bovine, activated factor X (Xa) in stage I, and remaining Xa is measured with the chromogene substrate Bz-Ile-Glu-Gly-Arg-pNA in stage II. In the presence of heparin, the inactivation is completed in 30 sec, and this method measures total Xa-inactivating capacity in diluted plasma (Method I). In a clincal material, this capacity showed a strong positive correlation (r=0.85) to the thrombin-inactivating capacity of diluted heparinized plasma (heparin cofactor activity) and apparently reflects antithrombin III (At-III) concentration. In the absence of heparin, the inactivation of factor xa occurs slowly. With an incubation of 5 min, about 25% of Xa is inactivated, and this assay reflects initial inactivation of Xa (Method II). With this method, a positive, but less strong correlation to the thrombin-inactivating capacity was found (r=0.58), indicating that inhibitors different from At-III accounts for a minor part of the initial inactivation. Determinations in plasma, in which At-III was removed by immunoadsorption, indicated that At-III accounts for about 80% of the initial inactivation. The results of the assays are not significantly influenced by varying concentrations of fibrinogen, fibrinogen degradation products or heparin in the test plasma.

Amides↗
PubMed1976

Study of the suppression of lactation and the influence on blood clotting with bromocriptine (CB 154) (Parlodel): a double blind comparison with diethylstilboestrol.

Inhibition of lactation was studied in 38 puerperal women in a double blind trial to assess the effect of bromocriptine in comparison with diethylstilboestrol (DS). Simultaneously the influence of both compounds on blood clotting was studied, along with a control group of 20 women not receiving any medication. Bromocriptine was given in a daily dose of 5 mg for 14 days and DS in a daily dose of 20 mg for 7 days followed by a placebo for a further 7 days. The first doses were not later than 8 hours after delivery. Both compounds showed an inhibitory effect on the onset of lactation and mammary congestion. This inhibitory effect on both parameters was significantly in favour of bromocriptine during the last days of the treatment due to rebound in the DS group. The bromocriptine doses used (5 mg daily for 2 weeks) caused no objective side effects and no subjective restraint. Treatment with bromocriptine caused no untoward effect on the blood clotting, while in the DS group a slower return to normal antithrombin III could be observed. Also in this group one case of thrombophlebitis occurred. Bromocriptine can be administered to puerperal women for the suppression of lactation.

Blood Coagulation↗