[Use of thrombin generation assay for the evaluation of coagulation and anticoagulant activity of hemostasis system in patients with abdominal sepsis].

Generally recognized factor, which complicates the course of sepsis, is the development of hypercoagulation syndrome. The increase of thrombin coagulation indicates on the elevation of risk of thrombus formation in microcirculation vessels, which could cause the formation of multiple organ failure. The thrombin generation assay is a new method of the evaluation of homeostasis system status. The test reflects the fermentation activity of thrombin and shows the functional condition, which arises in the interaction of procoagulant and anticoagulant. The diagnosis of generalized peritonitis had 30 patients (18 men and 12 women, aged 61+/-18,3 years) and they were included in the research. It was shown, that the use of thrombin generation assay in patients with the abdominal sepsis could give the well-timed analysis of hypercoagulation changes and the assessment of protein C system investment in the thrombin generation.

[The conditions of arrangement of the thrombin generation test to detect the hypercoagulation status].

The study covered the impact of modes of preparation of plasma samples to arrange the thrombin generation test for the purpose to establish adequately the hypercoagulation status. The optimal regimen is determined to prepare the samples to be used in the study. The group of females was involved into the study to take the composite oral contraceptives to demonstrate the possibility to apply the thrombin generation test to reveal the hypercoagulation.

[Experimental quality assessment of APTT-control reagent kits in the study of heparin-containing plasma in therapeutic ranges].

Investigation of activated partial thromboplastin time (APTT) in the plasma samples containing different levels of heparin determines the following parameters of the quality of APTT-control reagent kits: coefficient of variation, linearity, sensitivity, and detection. The kit is shown to meet GOST P 51352-99 requirements. The determination of the validity coefficient of approximation has proven a directly proportional functional relationship of the APTT values to the level of heparin in therapeutic ranges in the logarithmic coordinate system. The kit may be used to monitor heparin therapy.

[Experimental quality assessment of APTT-control reagent kits in the study of plasma with varying Factor VIII activity].

An investigation into activated partial thromboplastin time (APTT) in the plasma samples with varying Factor VIII activities has determined the following parameters of the quality of APTT-control reagent kits: coefficient of variation, linearity, sensitivity, and detection. The kit is shown to meet GOST P 51352-99 requirements. The determination of the validity coefficient of approximation has proven a directly proportional functional relationship of the APTT values to the Factor VIII activity in the bilogarithmic coordinate system. The kit may be used to diagnose hemophilia A and Willebrand disease.

[The state of oxidant-antioxidant system in basal and latent hyperhomocysteinemia in patients with atherosclerosis of the lower extremity arteries].

The diagnostics of basal and post-load (latent) hyperhomocysteinemia (HHC) was made in 110 patients with atherosclerosis of lower extremity arteries. Basal HHC was found in 61% of the patients. Latent HHC was found when using a methionine load test in 20 (47%) out of 43 patients without basal HHC. Patients with latent HHC had more pronounced tension of OAS.

[Blood cell aggregation and oxidative stress in pathogenesis of ischemic stroke]. / Agregatsiia kletok krovi i okislitel'nyi stress v patogeneze ishemicheskogo insul'ta.

Rheologic properties of blood cells and a state of oxidative-reductive processes and blood systems have been studied in 75 patients in acute period of ischemic stroke. The signs of oxidative stress development and simultaneous augmentation of blood cells aggregation were found. Shifts of redox-equilibrium in thiol-disulfide and ascorbate oxidative-reductive blood systems and cells aggregation dependence on their state were detected. An interrelation of oxidative processes and blood cells aggregation with clinical course severity and outcome was revealed. The authors discuss possible mechanisms for blood cells aggregation in oxidative stress. Including of antioxidants in the pathogenetic therapy and their earlier usage reduce essentially the intensity of oxidative stress and blood cells aggregation and promote neurological symptoms regress. The results obtained allow considering antioxidant treatment as a pathogenic modality for prevention and treatment of ischemic stroke. Clinico-laboratory correlations suggest a pathogenic role of oxidative stress in ischemic stroke as a factor augmenting aggregation processes and promoting intravascular thrombogenesis.

[Factor VIII activity in healthy subjects with respect to a blood group according to the AB0 system]. / Aktivnost' faktora VIII u zdorovykh lits v zavisimosti ot gruppovoi prinadlezhnosti krovi po sisteme AB0.

The investigation of the coagulation activity of factor VIII in persons with different blood groups is important e.g. for a more accurate diagnosis of Willebrand's diseases. The recent study data confirm that lower values of the factor VIII activity are typical of healthy subjects with blood group 0, residing in Saint Petersburg, versus persons with blood groups A, B, and AB. Limits were defined for the permissible fluctuations of the factor VIII activity. With P = 0.95, they are estimated by formula A(n) = m +/- 1.64 omega and their approximate values are as follows: A(n) = 102 +/- 48 for persons with blood group 0, A(n) = 124 +/- 54 for persons with blood groups A, B, and AB.

[Genetic determinants of hereditary thrombophilia in pathogenesis of venous thrombosis]. / Geneticheskie determinanty nasledstvennoi trombofilii v patogeneze venoznogo tromboza.

AIM: To study the role of genetic determinants of hereditary thrombophilia in pathogenesis of various clinical manifestations of venous thrombosis in the citizens of the North-West Region of Russia. MATERIAL AND METHODS: Mutations of the genes of factor V (FV Leiden), prothrombin (G20210-A) and polymorphism C677-T in the gene of methylentetrahydrofolate reductase (MTHFR) were detected using polymerase chain reaction (PCR) with a following restriction analysis of PCR product in 183 patients with venous thrombosis (115 with isolated thrombosis of the deep veins and 68 with thromboembolism of the pulmonary artery). RESULTS: It was established that mutation FV Leiden is a significant risk factor of deep vein thrombosis in the legs and postthrombotic disease, but this mutation is weakly associated with pulmonary artery thromboembolism (PAT). An essential PAT risk factor is carriage of the variant prothrombin G20210A. CONCLUSION: Determination of prothrombotic genotypes is a key factor of treatment efficacy and prevention of life-threatening thromboembolic complications.

[Analytical method for evaluation of coagulation activity of factor VIII]. / Analiticheskii metod otsenki koaguliatsionnoi aktivnosti faktora VIII.

A single-stage method is used for evaluating factor VIII (fVIII) clotting activity. This method is based on evaluation of activated partial thromboplastin time with fVIII-deficient plasma as the substrate. The activity of fVIII in the plasma is estimated by the graphic analytical method, which is difficult and not sufficiently accurate. An analytical method for estimating the activity of fVIII is validated. The authors prove the adequacy of empirical model used for evaluation of fVIII activity on the basis of results of processing of a vast scope of experimental data. The range of values for this parameter is -6.00 +/- 0.16.

[Changes in hemostasis system in patients with hereditary thrombophilia caused by mutation of blood coagulation factor V ( factor V Leiden)]. / Izmeneniia v sisteme gemostaza u bol'nykh s nasledstvennoi trombofiliei, obuslovlennoi mutatsiei faktora V svertyvaniia krovi (faktor V Leiden).

AIM: To study the incidence of mutation of Leyden's factor V in patients with venous thrombosis and the hemostatic system in carrier of this genetic defect. MATERIALS AND METHODS: A hundred and one patients aged 15-69 years who had venous thrombosis and 10 individuals with mutation of Leyden's factor V without manifestations in the history of thrombosis were examined. Factor V gene mutations and the thrombocyte and plasma links of hemostasis were determined by routine methods. RESULTS: The Leyden's factor V genotype Arg506-->Gln was detected in 17 of the 101 patients with venous thrombosis. Patients and asymptomatic individuals with this factor were found to have significant hypercoagulation, as evidenced by lower activated protein C-resistance index, higher factor VIII (von Willebrand's factor) activity, elevated von Willebrand's factor antigen levels, and enhanced intravascular platelet activation. In the presence of lupoid anticoagulant, hypercoagulation increased and protein C activity decreased. CONCLUSION: Detection of signs of hypercoagulation in patients with inherited thrombophilia at recovery in carriers of Leyden's factor V without clinical manifestations of thrombosis shows it necessary to make a particularly careful monitoring of the hemostatic system in these subjects. This is especially important for hypercoagulation-predisposing situations, such as pregnancy, surgical interventions, long-term immobilization, use of contraceptives, etc. when preventive measures may be used to prevent thrombotic events.

[Effects of methods of freezing and thawing of blood plasma on the activity of procoagulants and antithrombin-III]. / Vliianie metodov zamorazhivaniia i razmorazhivaniia plazmy krovi na aktivnost' prokoaguliantov i antitrombina-III.

The authors investigated the activity of procoagulants and antithrombin-III after freezing and thawing of blood plasma by different methods. It was shown that quick freezing and thawing using special apparatuses best of all preserved the coagulative properties of the plasma. The medical efficiency of quick-frozen plasma was shown to depend on the method of freezing and thawing.

[Leukocyte and thrombocyte glycosaminoglycans in hemophilia A and von Willebrand's disease]. / Glikozaminoglikany leikotsitov i trombotsitov pri gemofilii A i bolezni Villebranda.

AIM: The study of glycosaminoglycanes (GAG) in leukocytes and platelets of patients with hereditary coagulopathy. MATERIALS AND METHODS: GAG concentration, composition and fraction identification were made in 25 patients with hemophilia A and 10 patients with Willebrand disease. RESULTS: In hemophiliacs, leukocytes contained low concentrations of GAG. In those with bleeding and synovitis GAG levels were lower than the average, in those with extensive hematomas in the absence of locomotor disorders the above levels were close to normal. Chondroitinsulphate dominated in GAG composition though it was less polydisperse. Heparin sulphate levels were elevated. Platelet GAG characteristics were close to normal. In Willebrand disease leukocyte GAG content and composition was similar to those in hemophilia A except some differences in electrophoretic properties of small GAG components. CONCLUSION: Metabolism and/or release of GAG from blood cells may be involved in pathogenesis of hemophilia A and Willebrand disease.

[Changes of Willebrand factor level in blood plasma of cancer patients and its role in hemostatic disturbances]. / Izmeneniia urovnia faktora Villebranda v plazme krovi onkologicheskikh bol'nykh i rol' ego v narushenii sistemy gemostaza.

Plasma concentrations of von Willebrand (WF) factor were measured in patients with different tumors and healthy donors. The study has shown the level of WF in cancer patients to be significantly higher than in healthy donors. Hypercoaggulation was identified by laboratory analysis in breast cancer patients only while patients with other malignant tumors revealed the signs of chronic DIC syndrome. Chemotherapy provoked further increase in WF level in the plasma of patients with acute myeloleukemia and breast cancer. The importance of plasma WF assay for diagnosis and prediction of thromboembolic complications in cancer patients is discussed.

[The diagnostic characteristics of von Willebrand's disease]. / Osobennosti diagnostiki bolezni Villebranda.

70 patients from 48 families were examined. Of them, 59 (84%) patients had type I Willebrand's disease (WD), 9 (13%) type II, 2 (3%) type III WD. Hemostasis was assessed by functional tests: APTT, FVIII activity, bleeding time, ristocetin-cofactor activity of plasma Willebrand factor (WF). The WF levels in plasma and platelets were measured on a Reader-210 Microwell system by enzyme immunoassay with 380 F2 monoclonal antibodies to human WF. The functional parameters in 65 patients in remission were within normal range in half the patients. The only objective diagnostic criterion of the patients inclusion into WB group was the level of WF in plasma, especially when patients with type I WD were examined. The level of WF was always low in patients of this group even in the presence of normal values of functional tests. The severity of WD course and definition of laboratory signs of the disease depended mainly on the involvement of platelet WF in pathological process. In patients with a decrease of both plasma and platelet WF the course of the diseases was most serious and laboratory data most shifted from normal.

[Anti-hemophilia drugs: from cryoprecipitate to factor VIII concentrates of high purity]. / Antigemofil'nye preparaty: ot kriopretsipitata k kontsentratam faktora VII vysokoi chistoty.

The methods have been surveyed concerning the isolation of concentrates of the factor VIII which are the drugs used in treatment of a hereditary disease--hemophilia. Prospects of improvement of these drugs have been considered, their characteristics (activity, purity, method of virus inactivation) are presented that permits one to orientate himself in a wide assortment of drugs, as well as to choose the concrete drug to be used in clinic.

[Immunoenzyme method of determination of Willebrand's platelet factor]. / Immunofermentnyi metod opredeleniia trombotsitarnogo faktora Villebranda.

A method for Willebrandt factor antigen measurement in platelets has been developed based on indirect solid-phase enzyme immunoassay with monoclonal antibodies. The mean platelets Willebrandt factor level in 17 normal subjects was 21.5% (S = +/- 8.88; S mean = 2.16%). The method was tried in a group of patients with Willebrandt's disease. A relationship was demonstrated between Willebrandt platelet factor level and the degree of disorders in hemorrhage duration.