[The significance of changes in fibrinogen levels during thrombolytic therapy in myocardial infarct]. / Význam zmen koncentrace fibrinogenu pri trombolytické lécbe infarktu myokardu.

The submitted work was concerned with two problems: a) investigation of the dynamics of changes of the fibrinogen and fibrin breakdown products after a single dose of streptokinase, b) evaluation of the effectiveness of thrombolysis from changes in the fibrinogen concentration. Two groups of patients were examined with the Q form of acute myocardial infarction who were treated at an intensive care unit. The first group comprised 62 patients (mean age 56.3 years) who were given 1 million units of streptokinase by the i.v. route. The second group comprised 52 patients who were given 1.5 million units of streptokinase. The authors investigated the fibrinogen plasma concentration and the fibrin breakdown product concentration in serum after 3-hour intervals. Concurrently they examined the creatine kinase curve. They proved a significant increase of the fibrinogen and fibrin degradation products before thrombolysis (p less than 0.001). The fibrinogen concentration declined in both groups highly significantly with a maximum after 12 hours. The fibrinogen level reached normal levels in both groups after cca 24 hours. Patients with a high initial fibrinogen level (above 5 g/l) did not attain hypofibrinogenic values during thrombolysis. This phenomenon did not depend on the size of the streptokinase dose. The decline of fibrin breakdown products in both groups declined to baseline values within 24 hours. The authors confirmed that the effectiveness of thrombolysis is influenced among others also by the residual fibrinogen value.

Metabolism of diamantane by rat liver microsomal cytochromes P-450.

1. Diamantane binds to liver microsomes from phenobarbital-treated rats with an apparent Ks value of 5.2 x 10(-7) mol/l. This value being lower than that obtained for perhydrophenanthrene indicates that diamantane is very strongly bound to microsomal cytochrome P-450. 2. Metabolic studies show that liver microsomes from phenobarbital-treated rats readily metabolize diamantane to mono-, di- and possibly tri-hydroxy derivatives, whereas liver microsomes from beta-naphthoflavone-induced rats do not bind this hydrocarbon or metabolize it. 3. Reconstituted cytochromes P-450 b and e were more efficient in the hydroxylation of diamantane than liver microsomes; metabolites formed by the reconstituted system do not include all the products formed by microsomes, which indicates the involvement of forms of cytochrome P-450 other than the isozymes b and e.