PO-56 - Subsequent clot properties depend on the storage time of platelet concentrates.

INTRODUCTION: Despite platelets properties varies during storage, transfused platelets are included in blood clot in the same way as well as native. We assume that after transfusion the prevalence of platelets with changed activity lead to worse quality of blood clot in vivo. AIM: The aim was the in vitro study of platelet-dependent clot properties that are formed from some stored platelet concentrates (PCs). MATERIALS AND METHODS: Twenty-six PCs in autologous plasma and 24 PCs in platelet additive solution SSP+ (MacoPharma, France) (70vol.%) were analized by thromboelastography with and without platelets activation, and by standard aggregometry. The testing were carried out at the day of proceeding, after 24 hours, and at 3rd and 5th days of storage. We used Trima Accel (Terumo BCT, USA) for the proceeding of platelets apheresis. RESULTS: We found that clot demonstrated gradual reduction of elasticity and deformability starting from second day to fifth day in stored PCs suspended in autologous plasma. From the third storage day platelets lost their meaning for clot properties. The platelets apheresis with next re-suspending in SSP+ solution leads to the depression for platelets aggregability. Actived platelets had no impact to clot properties during full storage time. Total decline of clot quality including low elasticity and impaired deformability were found starting from 3rd storage day compared to the day of proceeding. CONCLUSIONS: We assume that such properties of clot as both elasticity and deformability are forming in PCs at the day of proceeding. Further clot changes observed in PCs does not depend directly from platelets aggregability because clot forming are under other influences. The last are determined mainly by the coagulation what was no included in this study. Also obtained results confirms the 5th-days storage as a benefit independent from PCs proceeding method.

PO-59 - Hemorheologic disturbances as thrombosis risk factor in patients with some myeloproliferative neoplasms.

INTRODUCTION: In today's antithrombotic prevention we forget that hemorheologic abnormalities are part of Virchow's triad. Isn't this one of reasons that venous thromboembolism (VTE) including catheter-related thrombosis (CRT) retain high frequency despite of modern antithrombotic therapy? AIM: The aim was to investigate rheological behavior of blood in patients with some myeloproliferative neoplasms. MATERIALS AND METHODS: The study included 16 adults with Polycythemia Vera (PV), 42 young with acute lymphoblastic leukemia (ALL), and 67 healthy donors as control group. Of patients 38% had thrombosis. We measured plasma viscosity, and whole blood viscosity (WBV) by shear rate from 300 to 5 s-1. Then indices were calculated for erythrocyte aggregation, and deformability, and non-Newtonian behavior of blood. Hematocrit, erythrocytes count, erythrocyte indices, leukocyte count, fibrinogen and B-type natriuretic peptide (BNP) were analyzed simultaneously. RESULTS: Increased WBV revealed totally in PV-patients but not by all shear rates in ALL-patients. Unlike donor, in patients WBV values had no equivalence under sequential one sample measurements with a decrease and then an increase of shear rates. We speculated this difference becomes diagnostic meaning like one and by its size. WBV dependent on leukocytes count, on MCH and mainly on MCV. Forty percent of patients had elevated BNP assuming subclinical cardiac dysfunction. The latter explains discoordinated changes in shear stress values required for fully reversible erythrocyte aggregation. As a result, residual units like "erythrocyte-erythrocyte" and/or "erythrocyte-leukocyte" interferes blood stream and violates mechanically blood flow in small vessels. Moreover in PV-patients but not in ALL-patients we found loss of non-Newtonian behavior of blood later than in control group. Both myeloproliferative neoplasms lead to increased erythrocyte aggregation but not impair deformability of red blood cells. In total these facts explains chronic hypoxia in these patients. CONCLUSIONS: Patients with some myeloproliferative neoplasms has abnormal blood flow properties. Revealed hemorheologic disturbances could be as a trigger to start of VTE or to growth of blood clot in the area of permanent venous catheter. These non-hemocoagulation conditions leaded for thrombus formation makes hemorheologic therapy looking attractive for antithrombotic management. The choice of targeted methods requires to continue this study.

[GENDER DIFFERENCES OF THE HEMOSTASIS POSTAGRESSIVE EARLY RESPONSE IN ACUTE NECROTIZING PANCREATITIS].

The study was performed in a group of 25 patients with acute necrotizing pancreatitis (mean age 46.2 ± 6.74 years). Gender differences of the hemostasis postagressive early response in the early stages of the disease were identified by comparing the procoagulant , anticoagulant and fibrinolytic blood activity of men and women suffering from pancreatitis. Compared to men, women showed higher concentrations of fibrinogen, D-dimer and VWF and smaller values marked trombokrit , antithrombin III, inhibitor of plasmin and protein C (p < 0.05). These results suggest a greater tendency to thrombi formation in women with acute pancreatitis; We believe that gender differences should be the subject of further research.

Effects of oxidized fibrinogen on the functions of blood cells, blood clotting, and rheology.

Oxidatively-modified fibrinogen induces platelet aggregation and potentiates ADP-induced platelet aggregation and production of active oxygen forms in zymosan-stimulated leukocytes. Fibrinogen induces IL-8 production in primary culture of endothelial cells from human umbilical vein; the oxidized form of fibrinogen is more active, similarly as during induction of the expression cell adhesion molecules (P-selectin and ICAM-1). Oxidized fibrinogen (10 and 20% oxidation degree) impairs microrheological properties of the blood, sharply reduces erythrocyte deformability, modifies blood viscosity, and reduces suspension stability of the blood. Oxidized fibrinogen modified blood clotting parameters and ADP-, ristocetin-, and collagen-induced platelet aggregation in whole blood. Oxidized fibrinogen disordered the formation of fibrin clot and blood clotting process. Platelet aggregation was activated in response to ADP, but not to ristocetin and collagen, the degree of activation increased in direct proportion to the degree of fibrinogen oxidation. This indicates the "dysregulatory" effect of oxidized fibrinogen on platelets. The formation of platelet complexes with polymorphonuclear leukocytes was intensified in the presence of oxidized fibrinogen; polymorphonuclear leukocyte luminol-dependent fluorescence intensity in the presence of platelets increased after incubation with oxidized fibrinogen in comparison with native fibrinogen. Hence, oxidized fibrinogen plays an important role in the development of atherosclerosis and its complications (thromboses).

[Changes in hemostasis at aortic surgery under conditions of extracorporeal circulation].

This paper describes hemostatic changes in patients who had undergone aortic surgery under conditions of extracorporeal circulation. The changes in the hemostatic system are marked by the thrombophilic condition made up for activation ox blood fibrinolytic activity in the preoperative period. The basic amount of blood loss falls within the first 6 hours after operation. Prolonged hypothermic extracorporeal circulation and the high intraoperative blood loss (over 35 ml/kg bw) lead to an appreciable decrease in antithrombin III and protein C activity which results in activation of disseminated intravascular blood coagulation in the early postoperative period and ineffectiveness of heparin therapy. Secondary hyperfibrinolysis together with combined thrombocytopenia and platelet dysfunction are the basic causes of higher than usual bleeding in patients after aortic surgery under conditions of extracorporeal circulation.

[Hemorheological changes during mammary coronary bypass grafting]. / Gemoreologicheskie izmeneniia pri operatsiiakh mammarno-aortokoronarnogo shuntirovaniia.

Hemorheological studies were performed in 44 patients subjected to mammary coronary bypass surgery during induction of anesthesia, at initiation of cardiopulmonary bypass, at the end of operation, on the 1(st) and 2(nd) or 3(rd) postoperative day. Methods included determination of whole blood and plasma viscosity with estimation of suspension stability and calculation of Caisson viscosity and fluidity limit. Rigidometry was used for assessment times of linear (T(1)) and three dimensional (T(2)) aggregates formation, final aggregates dimensions, total hydrodynamic strength of aggregates (beta), index of strength of especially large aggregates. Indexes of aggregation and deformation of erythrocytes were also calculated. Cardiopulmonary bypass was associated with lengthening of T(1) and shortening of T(2), increase of aggregates dimension and their hydrodynamic strength beta and lowering deformability of erythrocytes. By the end of operation increase of difference between Caisson and asymptotic viscosity was noted. Postoperative period was characterized by improvement of deformability of erythrocytes, prolongation of T(2), increases of aggregates dimension, their hydrodynamic strength beta, and fluidity limit. Thus measures of intensive therapy should be directed at correction of disturbances of rheological properties of blood with consideration of their changes specific for cardiosurgical patients.

Oxidatively modified fibrinogen modulates blood rheological parameters.

We studied the effect of UV-oxidized fibrinogen with oxidation degrees of 10 and 20% on rheological parameters of the blood. The effect of fibrinogen with 10% oxidation degree was moderate and variable, which attests to its partial compensation with the pool of natural antioxidants. The effect of fibrinogen with 20% oxidation degree was more pronounced. It dramatically decreased deformability of erythrocytes, delayed formation of linear aggregates, accelerated formation of 3D-aggregates, enhanced the total hydrodynamic strength of aggregates, but decreased stability of the largest aggregates. It did not increase plasma viscosity, but enhanced viscosity of the blood at all shear rates. At both degrees of oxidation, suspension stability of the blood decreased, the Caisson viscosity did not change, and the difference between the values of Caisson and asymptotic viscosities markedly increased. On the whole, oxidative fibrinogen produces negative changes in blood rheological parameters, and its effect depends on the degree of oxidation.

Effect of oxidized fibrinogens on blood coagulation.

We studied the effect of UV-irradiated fibrinogen on blood coagulation. Fibrinogen with oxidation degree of 10% moderately activated the intrinsic pathway, but inhibited the extrinsic pathway of blood coagulation. Fibrinogen with oxidation degree of 20% inhibited both the extrinsic and intrinsic blood coagulation pathways. We revealed disturbances in the formation of fibrin clot with oxidized fibrinogen, suppression of platelet aggregation mediated by collagen receptors, and inhibition of aggregation associated with von Willebrand factor activity. ADP initiated platelet aggregation, which was in direct proportion to the degree of fibrinogen oxidation. Our results indicate that oxidized fibrinogen produces a dysregulatory effect on platelets.

[Hemorheological changes at reconstructive operations on the aorta]. / Gemoreologicheskie izmeneniia pri rekonstruktivnykh operatsiiakh na aorte.

Fifteen patients who had undergone aortic reconstructions were examined. Hemorheologic studies were performed at the following stagest initial anesthesia, the end of operation, the early postoperative period, and the 2nd-3rd days after operation. A study was made of blood viscosity at a shift rate 5-300 s(-1), of suspension stability, caisson viscosity (CV), and the yield stress (YS). The back light diffusion intensity was recorded on the erythroaggregometer ADE=5 (Russia) to evaluate the time of linear aggregate formation (T(1)), the time of three-dimensional aggregate formation (T(2)), characteristics of the end size of the aggregates (Ampl), total hydrodynamic strength of the aggregates (Beta), strength index of especially large aggregates (Ia((2,5))). The index of erythrocyte aggregation (IEA) and the index of erythrocyte deformation (IED) were also computed. Initially, the normal blood viscosity values were marked. However, in the early postoperative period, their values returned to the preoperative level. In patients with complications, blood viscosity appreciably rose, exceeding the preoperative parameters. At the end of operation there was a decrease in erythrocyte aggregation, especially due to the TT(1) and Ampl rise, while beta dropped. In the postoperative period, patients without complications demonstrated the growth of erythrocyte aggregation but Ampl of cell aggregation diminished. In the postoperative period, patients with complications showed a considerable intensification of erythrocyte aggregation due to the rise of Ampl, Beta and Ia((2,5)). Toward the end of operation a decrease of plasma viscosity was revealed in the presence of GV rise. In the postoperative period, patients with complications demonstrated the growth of plasma viscosity concurrently with CV lowering. Toward the end of operation the YS increased. However, in patients with the uncomplicated postoperative period, the magnitude of this parameter dropped and reached permissible values in the given patient group whereas in patients with complications, the YS remained significantly high.

[Prophylaxis of thrombotic complications in microsurgical auto-transplantation of tissue complexes]. / Profilaktika tromboticheskikh oslozhnenii pri mikrokhirurgicheskoi autotransplantatsii tkanevykh kompleksov.

Problems of prophylaxis of intra- and postoperative thrombotic complications are discussed basing on the experience of treatment of more than 1500 patients who underwent microsurgical autotransplantation of tissues. Influence of non-fractionated heparin, acelysin and low-molecular heparin on hemostasis in combination with standard hemodilution after microsurgical autotransplantation was analyzed. Scheme of treatment before, during and after surgery are developed for prophylaxis of thrombotic complications.

[Hemorheology and morphofunctional characteristics of blood cells in children with congenital heart defects]. / Gemoreologiia i morfofunktsional'nye osobennosti kletok krovi u detei s vrozhdennymi porokami serdtsa.

Patients with congenital heart diseases (CHD) aged 4 months to 12 years, hospitalized for surgical treatment, were examined. Complex viscosity of the blood and the constituents of this parameter (dynamic viscosity and elastic component) were evaluated in the range of shift strain corresponding to the range of shift velocities 0.37-500 s-1 at a frequency of 2 Hz. The threshold blood fluidity was estimated for evaluating the conditions under which erythrocyte disaggregation begins. The relationship between blood rheology and morphofunctional characteristics of blood cells was evaluated. In accordance with the findings, the patients were divided into 3 groups with different suspension stability of the blood. In group 1 the threshold fluidity approximated the norm. In group 2 with normal blood rheology the shifts were compensated and regulation of rheology was in general intact. In group 3 the hematocrit values, mean erythrocyte volume, mean concentration of hemoglobin in erythrocyte, leukocyte counts, and complex viscosity of the blood were the highest, while the suspension stability was the lowest, which indicates depletion of the adaptive potential of the organism. Hence, blood rheology in patients with CHD differs by the type of regulation, mechanisms and compensation of changes, and depend largely on the mean erythrocyte volume, mean hemoglobin concentration in erythrocytes, and leukocyte counts.

[Changes in blood rheological properties and erythrocyte osmotic resistance in activation of free radical processes]. / Izmenenie reologicheskikh svoistv krovi i osmoticheskoi rezistentnosti éritrotsitov pri aktivatsii svobodnoradikal'nykh protsessov.

Relationship between serum oxidation of different degree and micro- and macrorheology of the blood and modification of this relationship in the presence of antioxidant alpha-tocopherol were studied. Lipid peroxidation affects blood rheology and erythrocyte osmotic resistance. Erythrocytes are the first to react to increased activity of free radical oxidation and to exhaust their compensatory potential. Plasma viscosity remains stable in serum oxidation of different degree, and therefore erythrocytes are responsible for changes in blood rheology during intensification of free radical oxidation. Moreover, erythrocytes are functionally resistant to oxidative stress in malonic dialdehyde concentrations under 3.62 +/- 0.41 nM/ml. alpha-Tocopherol increases functional resistance of erythrocytes and maybe of protein components of the plasma to damaging action of free radicals.

Effects of low-density lipoproteins on blood coagulation and fibrinolytic activity.

In vitro experiments showed that copper-oxidized low-density lipoproteins activate factors of the prothrombin complex in the whole blood and inhibit fibrin generation in both blood and plasma. Moreover, oxidized low-density lipoproteins inhibit fibrinolysis and impair the structure of fibrin clot, which results in hypercoagulation.

[The prevention of thrombus formation and the improvement of the blood rheological properties during operations with a microsurgical technic. I. The possibilities for using acelysin--an acetylsalicylic acid derivative]. / Profilaktika tromboobrazovaniia i uluchshenie reologicheskikh svoistv krovi pri operatsiiakh s mikrokhirurgicheskoi tekhnikoi--I. Vozmozhnosti ispol'zovaniia atselizina--proizvodnogo atsetilsalitsilovoi kisloty.

Changes in the blood clotting system and rheology were studied in 39 patients during reconstructive operations making use of microsurgical methods. Effects of various doses of water soluble acelysine, an acetylsalicylic acid preparations (DL-lysine acetylsalicylate and glycine) have been evaluated during surgery and the immediate postoperative period. Clinical and laboratory changes in blood coagulation were determined at different doses (1000, 500, and 250 mg). Even in low doses (3.94 +/- 0.25 mg/kg) acelysine ensured chronometric and structural hypocoagulation as early as 1 h after dosed infusion and throughout the entire intervention, preventing thrombosis of microvascular anastomoses. Administration of acelysine in doses higher than 250 mg is not recommended, because higher doses involve the risk of hypocoagulation complications.

[The diagnostic value of blood rheology studies in cardiac surgical interventions]. / Diagnosticheskaia znachimost' issledovanii reologii krovi pri kardiokhirurgicheskikh vmeshatel'stvakh.

The diagnostic value of routine studies of blood rheology in cardiosurgical patients was investigated. Blood rheology, hemostatic system, and acid-base balance were analyzed in 75 cardiosurgical patients during the early postoperative period. In 41 of these the postoperative period was uneventful and 34 patients developed complications. The blood fluidity conditions and estimation of the risk of thrombotic and hemorrhagic complications were assessed using the "Aggregate Status of the Blood" software. The data indicate a high diagnostic and prognostic significance of plasma viscosity, relative blood viscosity, erythrocyte aggregation and deformability indices in evaluation of the status of cardiosurgical patients in early periods after surgery. Application of hemorheological studies as routine methods for examination of patients improved the quality of treatment. Hence, rheological studies of the blood and plasma should become an obligatory component in the diagnosis of the hemostatic status in the early postoperative period after aortocoronary bypass surgery.

[Novel method for calculation of hemostatic potential and its clinical applications. 2]. / Analiz novogo metoda rascheta gemostaticheskogo potentsiala i vozmozhnosti ego klinicheskogo ispol'zovaniia (soobshchenie 2).

A formula for calculating the hemostatic potential is proposed: HV = -{Ig[(APTT + PTTIS)/(WBCT.Hct)] + IgPF/PT}, where APTT is activated partial thromboplastin time, sec; PTT prothrombin time, sec; IS index of sensitivity of thromboplastin reagent used; WBCT whole blood clotting time after Lee-White, sec; Het hematocrit; PF probability of liquid blood preservation: and PT probability of thrombotic complications. The aim of the study was to evaluate the probability of practical use of the method and its practical potentialities. Statistical analysis (1014 specimens from 402 patients) confirmed the correctness (plausibility) of our concept and of the model of hemostatic potential. Despite the difficulties of calculation, the resultant hemostatic potential value represents the actual conditions of hemostasis in vivo. The physiological norm is represented as small-positive values of hemostatic potential, reflecting the constant "readiness" of blood to coagulation. Time course of hemostatic potential demonstrates the hemostasis status and its stability during various exposures. The homeostatic potential is a value highly sensitive to hemostatic status and outer exposures. Its changes can be used as a criterion of therapy efficacy.