Marek Wojtukiewicz

Alterations of haemostasis parameters with special reference to fibrin stabilization, factor XIII and fibronectin in patients with obliterative atherosclerosis

Intravascular and endoparietal fibrin deposition are thought to be involved in atherosclerotic process, especially when fibrin is stabilized by factor XIII of coagulation system. The study carried out on a group of 50 patients with obliterative atherosclerosis of the lower limbs revealed an increased plasma fibrin stabilizing activity apparently due to an increased F.XIII level. Furthermore, alterations in coagulation and fibrinolysis indicating hypercoagulable tendency were found. It is concluded, that the observed changes may contribute to the development of atherosclerotic process.

Absence of components of coagulation and fibrinolysis pathways in situ in mesothelioma

Interest in the mechanisms of interaction of mesothelioma with the coagulation mechanism stems from its common association with thrombocytosis (3,5,6) and hypercoagulability manifested by a high incidence of venous thromboembolism (3). The results of studies on the mechanism of coagulation activation in mesothelioma (using immunohistochemical techniques) are the subject of this report

XYY syndrome and acute myeloblastic leukemia

A 69-year-old man with hypogonadism was found to have a 47,XYY karyotype. Clinical and laboratory data revealed acute nonlymphocytic leukemia (ANLL) of the M2 type. The association between the XYY and ANLL-M2 is most likely accidental coincidence.

Platelet activation and its role in thrombin generation in platelet-induced thrombin generation time

Platelet-induced thrombin generation time (PITT) is a newly developed global coagulation assay in which a small amount of partially anticoagulated platelet-rich plasma (PRP) is rotated in a disc-shaped cuvette within the light beam of a photometer. The time intervals from onset of rotation until aggregation and coagulation of the sample are registered. The aim of our study was to compare platelet activation with generation of thrombin during rotation of PRP in PITT system. Aliquots of PRP were taken before, 1, 3, and 8 min after the onset of rotation as well as at the beginning of aggregation and shortly before coagulation. Thrombin activity was measured with chromogenic substrate S-2238. We have also measured the level of generated prothrombin activation fragment 1+2 (F1+2), which reflects the concentration of liberated thrombin. Platelet activation was assayed by means of platelet factor 4 (PF4) and beta-thromboglobulin (beta-TG) concentration and registration of the aggregation. The concentrations of the F1+2, PF4, beta-TG increased very slowly from the beginning of the test until aggregation occurred. From the start of aggregation, the levels of F1+2 rose rapidly. In contrast to the F1+2 measurements, thrombin activity has not been detected from onset of rotation until the end of the test. Only trace thrombin activity was detectable just after the plasma sample had been clotted in the cuvette. Our results demonstrate that there exists a close relationship between platelet activation and thrombin generation. Viable platelets, which adhered to the cuvette walls, form an active template on which thrombin can be generated from prothrombin.

Platelet-induced thrombin generation time II (PITT II). A modified global coagulation test to monitor prophylactic anticoagulation with vitamin K antagonists?

Anticoagulants (heparins, heparin-like mole- cules, vitamin K antagonists) in vivo as well as in vitro (except for oral anticoagulants) markedly