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Biomedical subjects

Z Vorlová

Publications and source records attributed to Z Vorlová.

At least 37 records · Page 2Linked to original sources

Ecarin test in diagnosis of dicoumarol therapy, liver diseases and DIC.

The conversion of prothrombin by ecarin is independent of the presence of gamma carboxyglutamic residues on the N terminal of the molecule. Ecarin converts therefore also the acarboxylated precursor-PIVKA II. In a group of 347 patients under dicoumarol therapy of different intensity and duration PIVKA was detected in BaSO4 adsorbed PPP only in samples where prothrombin level (Quick's test) was lower than 50% of normal values. Increase in PIVKA did not correspond to the decrease of prothrombin. In some cases where the treatment was longer than two years no PIVKA was detected even when prothrombin was under 20%. This is explained by synthesis of partially carboxylated prothrombin molecules, which can be adsorbed. In liver diseases the ecarin test and Quick's time in native, untreated PPP showed about identical decrease of prothrombin level. This indicates that no PIVKA is released to plasma. The functional defect of the hepatocyte does not involve gamma carboxylation as long as vitamin K is provided. In patients with DIC ecarin test showed significantly higher level of thrombin activity than those obtained with Quick's test. It is known that during hypercoagulation stage of DIC prethrombin 1 and 2 are formed by the excess of thrombin. These split products of prothrombin are convertible by ecarin to meizothrombin 1 and 2. A positive ecarin test can be also due to acarboxylated precursors which are released during increased proteosynthesis triggered by consumption coagulopathy.

Diagnosis, Differential↗

[Lyophilized plasmas for the control of thromboplastin time values and calibration of thromboplastins].

The paper deals with the production of normal and pathological plasmas for the calibration of thromboplastin. Calibration is performed according to WHO principles. We compared single charges of thromboplastin (Sevac, CSSR, human brain) with each other and a selected reference charge with British thromboplastin. Lyophilised reference plasmas produced (20-50 healthy blood donors) and plasmas taken from patients treated with coumarin derivates (single and mixtures) could replace their fresh equivalents which was confirmed by testing 4 different batches. The stability of these plasmas (for a time of at least 12 months) was proved by repeated checks. These plasmas also served as controls in other laboratories in Czechoslovakia.

Blood Coagulation Tests↗

[Significance of the laboratory diagnosis of hypercoagulability].

Alterations characteristic of the hypercoagulation syndrome such as changes in fibrinogen content, in FDP concentration and platelet counts as well as the presence of fibrinogen complexes were demonstrated by laboratory findings in 175 patients with severe diseases and disturbances of haemostasis. Twenty per cent of the patients showed no clinical signs of disturbances of haemostasis, in 32.5 per cent pronounced venous thrombosis occurred, bleeding complications arised in 28 per cent and microthrombosis developed in 20 per cent. The different findings in the individual groups are assumed to be due not only to haemostatic factors but also to other ones.

Blood Coagulation Tests↗

Lyophilised plasmas for one-stage determination of factor VIII.

Two batches of lyophilized normal pooled HEPES-stabilized plasma according to ZUCKER [11] and LOELIGER [7] were prepared. The F VIII activity established by the activated partial thromboplastin test (APTT-VIII) was identical in both plasmas and amounted to 0.99 U/ml (95% confidence limits 0.87 to 1.17 U/ml). It did not change within 11 months in plasmas according to ZUCKER, and 6 months in those according to LOELIGER (further on not followed). We prepared four batches of lyophilized HERPES-stabilized substrate plasma (severe form of hemophilia A) according to ZUCKER. They were employed for 5 to 13 months in APTT-VIII along with the frozen 3.2% sodium citrate substrate plasmas. The results showed a satisfactory agreement. The lyophilized plasmas did not influence even the dose-response-line. On the ground of these results we consider the reported lyophilized plasmas to be suitable reagents in APTT-VIII technique.

Blood Coagulation Tests↗