Formation and elimination of soluble fibrin and D-dimer in the bloodstream.

Soluble fibrin is composed mainly of desA fibrin and fibrinogen oligomers consisting of fewer than 16 monomers partially cross-linked by factor XIIIa. Soluble fibrin cannot stimulate Glu-plasminogen activation by tissue plasminogen activator (t-PA); therefore, it may not be a direct predecessor of D-dimer. However, within the microcirculatory system, soluble fibrin oligomers may form microclots.

Decrease of prothrombin level during thrombolysis in acute myocardium infarction.

Previously, the direct interactions of Bβ26-42 fibrin residues with prothrombin were demonstrated. It was also shown that forming prothrombin complexes with E- or DDE-fragments causes non-enzymatic prothrombin activation. The direct measuring of the prothrombin level in the blood plasma of patients with acute myocardial infarction (AMI) allowed us to find a situation where such an activation can occur in vivo.

Blood coagulation factors and platelet response to drug-induced hepatitis and hepatosis in rats.

Background: Knowing the variability of blood coagulation responses to liver damage of different origins can provide a key to curing liver tissues or to mitigating treatment side effects. The aim of the present work was to compare the changes in the main components of hemostasis under experimental drug-induced hepatosis and hepatitis in rats.

Methods: We modeled diclofenac-induced hepatitis and tetracycline-induced hepatosis.

N-Stearoylethanolamine Inhibits Integrin-Mediated Activation, Aggregation, and Adhesion of Human Platelets.

N-stearoylethanolamine (NSE), a lipid mediator that belongs to the N-acylethanolamine (NAE) family, has anti-inflammatory, antioxidant, and membranoprotective actions. In contrast to other NAEs, NSE does not interact with cannabinoid receptors. The exact mechanism of its action remains unclear.

The Rise of Factor X Level in Blood Plasma of Patients at Severe Burn Injuries.

This work is dedicated to the detection of imbalance between the pro- and anticoagulant branches of hemostasis at severe burn injuries by evaluating the content or activity of individual clotting factors. To select the targets for accurate diagnostics we measured the concentrations of soluble fibrin monomeric complexes and fibrinogen, levels of total prothrombin, factor X, protein C, and antithrombin III, and recorded the time of clotting in activated partial thromboplastin time and prothrombin time (PT) tests. Factor X level was increased in 26% of patients on the 1st day after the burn and it rose further in 62% patients on the 14th day of recovery.

Antiplatelet and anti-proliferative action of disintegrin from Echis multisquamatis snake venom.

Aim: To purify the platelet aggregation inhibitor from Echis multisquamatis snake venom (PAIEM) and characterize its effect on platelet aggregation and HeLa cell proliferation.

Methods: Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) were used for PAIEM identification. Platelet aggregation in the presence of PAIEM was studied on aggregometer Solar-AP2110.

Isolation and purification of Bacillus thuringiensis var. israelensis IМV В-7465 peptidase with specificity toward elastin and collagen.

Peptidase of Bacillus thuringiensis var. israelensis IМV В-7465 was isolated from culture supernatant using consecutive fractionations by an ammonium sulphate (60% saturation), ion-exchange chromatography and gel-filtration on the TSK-gels Toyoperl HW-55 and DEAE 650(M). Specific elastase (442 U∙mg of protein-1) and collagenase (212.

Non-enzymatic activation of prothrombin induced by interaction with fibrin β26-42 region.

We have discovered that addition of monomeric desAB fibrin to prothrombin leads to appearance of the thrombin-like activity of prothrombin towards S2238 chromogenic substrate. DesA and desABβ(15-42)2 fibrin forms did not cause any activation of prothrombin. From this observation we could suggested that amino acid residues of the 15-42 fragment of BβN-domain presented in desAB fibrin, cleaved in desABβ(15-42)2 fibrin and protected in desA fibrin, play a crucial role in the non-enzymatic activation of prothrombin.

Limited proteolysis of fibrinogen by fibrinogenase from Echis multisquamatis venom.

Previously we purified fibrinogenase from venom of Echis multisquamatis and showed that the enzyme predominantly cleaves BβArg42-Ala43 peptide bond of fibrinogen. A much slower hydrolysis of its Aα-chain was also shown. To evaluate the accessibility of the hydrolysis sites to fibrinogenase's hydrolytic action, the pathway of cleavage of Aα- and Bβ-chains of fibrinogen, monomeric and polymeric fibrin desA and desAB has been investigated using western blot with monoclonal antibodies to Bβ 26-42 and Aα 20-78 of fibrinogen.

Fibrin(ogen)olytic and platelet modulating activity of a novel protease from the Echis multisquamatis snake venom.

The variety of enzymes including serine proteases that possess fibrin(ogen)olytic and platelet modulating activity have been discovered in different snake venoms. In our work the fibrin(ogen)olytic and platelet modulating activity of a new protease from Echis multisquamatis snake venom was studied. It was shown that purified enzyme cleaved the ВβR42-A43 bond of fibrinogen during first contact with the substrate following much slower hydrolysis of C-terminus of fibrinogen Aα-chain.

[Assessment of protein synthesizing function of the liver in experimental hepatitis].

Liver protein synthesis was estimated comparing the levels of prothrombin and its inactive form PIVKA-prothrombin. The latter indicates liver dysfunction. These diagnostic tests allow monitoring the effectiveness of the commonly applied preparation "Essentiale Forte" and that of the liposomal form of the biologically active additive (BAA) FLP-MD based on phospholipids of various origin.

[Influence of prothrombin cleavage products on platelet activation and aggregation].

Meizothrombin efficiently activates mechanically triggered platelets and enhance collagen-, ADP- and adrenalin-induced aggregation of platelet-rich blood plasma. Thus, in clotting system activation zone meizothrombin is able to enhance process of involving platelets in clotformation. Pre-thrombin 1 inhibits collagen-, ADP- and adrenalin-induced aggregation of platelet-rich blood plasma and so regulates not only plasm but platelet hemostasis by reverse negative relation.

[Thrombin and anticoagulant therapy].

New data which reveal rational approaches for pharmacologic control of blood coagulation process and confirm the key role of thrombin in haemostasis processes compared with other proteinases are presented in the review. Modulation of thrombin properties described in the review gives a new possibility for creating anti-thrombin preparations. Thrombin allosteria can serve a basis for development of new therapy.