Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis
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Blood Coagul. Fibrinolysis · Oct 1996
A thromboelastography study on the in vitro effects of L-arginine and L-NG-nitro arginine methyl ester on human whole blood coagulation and fibrinolysis.
The effects of L-arginine and L-NG-nitro arginine methyl ester (L-NAME) on human blood coagulation and fibrinolysis were studied in vitro using computerized thromboelastography and native whole blood. L-Arginine (8-80 microM) prolonged the split point (SP), reaction time (R) and biKoatugulierung time (K); and diminished the angle (alpha), maximum amplitude (MA) and TEG index. L-NAME (0.5-50 microM) shortened SP, R and K and increased alpha, MA and the TEG index in a concentration-dependent manner. ⋯ These results are consistent with the inhibitory effects of NO on platelet function and of the platelet-aggregating properties of NOS inhibitors. In addition, NO may play an inhibitory role in the process leading to fibrin formation and also on the interactions between platelets and fibrin. Such effects may be important when considering the clinical use of drugs that affect the NO-cGMP pathway.
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Blood Coagul. Fibrinolysis · Jul 1996
DDAVP infusion in haemophilia A carriers: different behaviour of plasma factor VIII and von Willebrand factor.
1-desamino-8-D-arginine vasopressin (DDAVP) increases factor VIII (FVIII) and von Willebrand factor (vWF) levels in patients with haemophilia A and in some patients with von Willebrand disease. It is generally held that the increase of FVIII is a consequence of the increase of vWF. Carriers of haemophilia A generally, but not always, show plasma FVIII levels lower than vWF due to an abnormality in one of the two alleles of the FVIII gene. ⋯ These findings indicate that after DDAVP, FVIII increases less or for a shorter time than vWF, also in haemophilia A carriers who have a normal FVIII/vWF ratio. Hence, DDAVP may help identify haemophilia A carriers, especially subjects with normal or borderline ratios. Even though molecular biology procedures at present are the best and more reliable tools to identify the carrier state, DDAVP seems to improve the accuracy of haemostatic parameters.
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Blood Coagul. Fibrinolysis · Jun 1996
Multicenter StudyMulticentric evaluation of heparinase on aPTT, thrombin clotting time and a new PT reagent based on recombinant human tissue factor.
In a multicentric study the influence of heparinase (Hepzyme) was evaluated on activated partial thromboplastin time, thrombin clotting time and prothrombin time using the recombinant human tissue factor and synthetic phospholipid (phosphatidylcholine and phosphatidyl-serine reagent). Hepzyme itself does not have any influence on normal coagulation values of activated partial thromboplastin time (aPTT) and prothrombin time (PT) assays whereas thrombin clotting time was prolonged by 10% (n = 60). In patients treated with unfractionated heparin for recent deep vein thrombosis (n = 47), plasma levels of aPTT, PT and thrombin clotting time (TCT) returned to the normal range in 100%, 97% and 91% after treatment with heparinase, respectively. ⋯ Freezing of plasma samples after treatment with heparinase resulted in a prolongation of the coagulation times in 15% of PT, 7% of aPTT and not of TCT values. The results show that treatment of plasma samples with heparinase abolishes the effect of unfractionated and low molecular weight heparin in vitro and ex vivo in patients during simultaneous treatment with oral anticoagulants. The use of heparinase may be of significance in patients with concomitant treatment of heparin and oral anticoagulants.
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Blood Coagul. Fibrinolysis · Jan 1996
Case ReportsIdiopathic chronic DIC controlled with low-molecular-weight heparin.
Chronic disseminated intravascular coagulation (DIC) is a rare coagulation problem usually associated with malignant diseases. The present report concerns a patient with chronic immune thrombocytopenic purpura (ITP) who developed chronic DIC which responded to low-molecular-weight heparin (LMWH) therapy.
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Blood Coagul. Fibrinolysis · Dec 1995
Dextran and hydroxyethyl starch interfere with fibrinogen assays.
We studied the haemostatic and volume effects of synthetic plasma substitutes and Ringer's solution in 48 surgical patients and found that the measured fibrinogen concentrations of patients receiving either dextran or hydroxyethyl starch (HES) were significantly higher than those predicted by the dilutional effects. The groups given Ringer's solution showed no apparent disproportion between fibrinogen concentration and plasma volume change. The results suggested that the presence of artificial colloids might interfere with the indirect fibrinogen assay used in the study. ⋯ Dilutions containing either dextran or HES gave significantly higher values (P < 0.001) than samples diluted with normal saline. We conclude that the results of indirect fibrinogen assays should be interpreted cautiously, when HES or dextran is used for volume replacement. This may be particularly true when hypofibrinogenaemia is encountered after extensive use of synthetic colloids during massive transfusion.