Görög Thrombosis Test

Abstract

This is the first laboratory evaluation of a new instrument, designed to test both platelet function and thrombolytic activity from a native blood sample, in vitro. The inventor assumed that the reduction and arrest of blood flow was due to activation, aggregation and stabilized thrombus formation by shear-activated platelets, and that re-establishment of flow was due to thrombolysis. Morphologic and functional studies presented here confirm these mechanisms. In vitro tests provided incontestable evidence for the principal role of platelets in the obstruction of flow (occlusion time) and for thrombolysis as the principal mechanism underlying the restoration of blood flow (lysis time). In addition to aggregation, it is the explosive generation of thrombin by shear-activated platelets that results in the formation of an occlusive haemostatic thrombus. Anticoagulation of blood completely prevented occlusion. Platelet-rich thrombus formation (occlusion time) was dose-dependently inhibited by monoclonal antibody against platelet glycoprotein (GP) Ib (6B4 and 12E4), aurin tricarboxylic acid, monoclonal antibody against platelet GPIIb/IIIa (MA-16N7C2 and abciximab), a synthetic GPIIb/IIIa antagonist (TAK-029), thrombin inhibitor (argatroban), and anti-von Willebrand factor, but not by anti-fibrinogen. Plasminogen activator streptokinase (Varidase) and tissue-type plasminogen activator (Monteplase) dose-dependently enhanced thrombolysis (lysis time) without affecting platelet function (occlusion time). The test is specific for thrombolysis. The plasmin inhibitor tranexamic acid prevented plasminogen activator-induced thrombolysis, while inhibition of clot retraction by cytochalasin B did not affect the lysis time. This rapid and sensitive global test of platelet function and thrombolytic activity could be of great value both in research and in clinical practice.

The antithrombotic effects of onion filtrates in rats and mice

“…It is widely appreciated, however, that thrombus formation in vivo is governed by interactions between blood flow, blood components and the blood vessel wall as proposed by Virchow, and the pathophysiological relevance of these tests to thrombotic status in vivo is not clear. Alterna-tively, innovative tests, in which non-anticoagulated blood is used and platelets are activated by shear force under flow, have been proposed [8,9,15]. Clinical and experimental studies have suggested that these tests may be more relevant to thrombotic status in vivo [8][9][10]16].…”

“…The technique has been described in detail elsewhere [15][16]. The instrument was purchased from Montrose Diagnostics Ltd., London, UK (www.globalthrombosis.com).…”

“…We have shown that different varieties of tomato, onion and strawberry can be classified according to shear-induced platelet-rich thrombotic activity (Haemostatometry), and that varieties of mulberry and carrot can be classified on this basis together with spontaneous thrombolytic activity (GTT) [11][12][13][14][15]. We have also demonstrated using Haemostatometry, that one onion variety cultivated in the northern part of Japan (Hokkaido) was notably antithrombotic [12] but the availability of this product remains limited.…”

Enhanced pre-operative thrombolytic status is associated with the incidence of deep venous thrombosis in patients undergoing total knee arthroplasty

“…The instrument and technique (GTT, Montrose Diagnostics, UK) have previously been described in detail [15]. The principle of the technique is detailed in Figure 2.…”

Antithrombotic Effects of Different Strains of Lactic Acid Bacteria

“…Previous studies have recognized the importance of pathophysiologically relevant tests to investigate hemostasis in vivo, and techniques such as the helium-neon (He-Ne) laser-induced thrombosis test have been developed for this purpose in animal experiments [8] [9]. In addition, Kovacs et al devised the technique of Haemostatometry [10] and the Global Thrombosis Test (GTT) [11]- [14] to assess physiological thrombosis in vitro, using non-anticoagulated blood. These methods are governed by shear-induced platelet activation in native blood, and have been shown to reflect the critical balance between thrombotic and thrombolytic activities [15] [16].…”