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At least 451 records · Page 25Linked to original sources
PubMed1982

[Effect of adrenergic beta-receptor blockaders on thrombocyte aggregation capacity in arterial hypertension].

The study of the aggregation capacity of platelets and the coagulation system of the blood by thromboelastography was undertaken in 36 patients with different forms of arterial hypertension. In 11 patients receiving obsidan these tests were repeated every 4-20 days. In patients with hypertension and pyelonephritis the aggregation capacity of platelets was enhanced, and in patients with glomerulonephritis it was not materially changed. All patients showed a shift in the food coagulation system toward moderate hypercoagulation, which did not change much with obsidan. A relationship between the blood pressure (BP) level and the functional properties of platelets was recorded. There was a simultaneous tendency to the decrease of BP and the inhibition of the aggregation capacity of platelets. Obsidan produces antiaggregation effect related to the decreased stability of platelet aggregates.

Adrenergic beta-Antagonists↗
PubMed1981

[Reaction between blood and heparin immobilized on synthetic polymers].

The influence of heparin covalent immobilization on its biological functions was studied. In-vivo experiments with prosthetic vascular devices made from polyethyleneterephthalate modified with heparin demonstrated that after 6 months of implantation to dogs the prostheses maintain their functions without thrombus formation. Thromboelastography and coagulograms showed that the decrease in the overall coagulant activity of the blood and changes in the most parameters of the coagulation system take place as a result of blood contact with heparin-containing polymers. In the animal body the changes observed were found to be rapidly compensated for. On studying the interaction of immobilized heparin with plasma proteins it was discovered that fibrinogen, thrombin and fibrinolysin are actively bound by immobilized heparin, with the resulting products being active in lysis of non-stabilized fibrin.

Animals↗
PubMedDate not supplied

[Clotting properties of the blood in severe craniocerebral injuries].

The time-course of changes in the blood coagulation potential were studied from the 1st to the 12th day in patients with craniocerebral injury by thromboelastography. Some of the thromboelastogram indices studied and their time-course are of prognostic significance in appraising the patients' condition. Irrespective of the severity of the clinical condition, similar changes were revealed in the coagulation system of patients and were regarded as disseminated intravascular coagulation of blood. Intravascular coagulation is the most intensive in patients with a fatal outcome. Hemostasis monitoring and correction of disorders of the coagulation system in the patients are recommended.

Blood Coagulation↗
PubMed1984

[Effects of a natural estrogen, estradiol, on hemostasis in guinea pigs].

17-beta-estradiol was administered weekly to female guinea-pigs at the dosage of 2-3 mg/kg body weight during 4-6 weeks. Compared to a control population, no significant effect was observed on: recalcification time; thromboelastography; PTT; APTT; Quick one stage prothrombin time; antigenic and active plasma fibrinogen level; antithrombin III level; factor XI level; red and white blood cell count. A significant increase in levels of factor II (+25%), of factor V, of factor XII (+40%) and a decrease in levels of complex VII + X was observed. Values for AT III, factor XII, chronometric and immunologic fibrinogen plasma levels, unknown until now for the guinea-pig, were established.

Animals↗
PubMed1982

[Effect of proteolysis inhibitors from Ascaris lumbricoides on the coagulation and fibrinolysis of human plasma].

By means of the method of ROLA & PUDLES modified by the authors the effect of trypsin and chymotrypsin inhibitors isolated from body walls of Ascaris lumbricoides on coagulation and fibrinolysis of human plasma in vitro was studied. The effect of both Ascaris inhibitors on coagulation phases I and II, the inhibition of thromboplastin and thrombin generations (thromboelastography, prothrombin and thrombin times) and the fibrinogenesis retardation of human plasma (time of lysis of euglobulin clot, time of clot fibrinolysis activated by streptokinase) were found. "The stairs phenomenon" was observed on thromboelastographic curves. The plasmin activity in an active form as well as its formation from plasminogen by streptokinase activation were reduced by chymotrypsin and trypsin Ascaris inhibitors alike.

Animals↗
PubMed1982

[Thrombocyte changes in electrically induced experimental thrombosis].

The influence of the function of the thrombocytes after electrical thrombosis induction by means of anodic direct current was investigated in 39 mongrel dogs. The platelet factor 3, the rotation thromboelastography, and the collagen induced thrombocytes aggregation in the optical test by Born was examined. The platelet factor 3 adhering on the thrombocytes decreased from 95% to 49% in the course of the thrombosis induction. Its activity was provable by means of the rotation thrombelastogram in the plasma. Besides of it the electrical field caused an activation of the thrombocytes which corresponds to a contact activation on foreign body surfaces. The collagen induced aggregation ability of the thrombocytes remains unaffected after the passage of the electrical field.

Animals↗
PubMed1982

[Use of mathematical methods of pattern recognition to evaluate the status of blood coagulation in acute cerebral ischemia].

The state of blood coagulation was examined in 244 patients with acute cerebral ischemia from the data of thromboelastography performed with the use of the image recognition methods. Eight variants of the hemocoagulation system response grouped into 3 leading hemocoagulation syndromes, such as hypercoagulation, hypocoagulation and mixed (hyper-hypocoagulation) ones, were differentiated. Rapid determination of the hemocoagulation response type (with the aid of discriminant analysis, without using a computer) in any patient with cerebral ischemia makes it possible to conduct (on respective clinical indications) individualized differentiated treatment with anticoagulants, desaggregants, or their combination. The method may be of use in treating other pathological conditions (thromboembolic disease, myocardial infarction, obliterations of lower extremity vessels, etc.) with these means.

Acute Disease↗
PubMed1980

[Thromboresistant properties of hydrophilic gels].

Hydrophilic gels were made using methyl methacrylate and N-vinylpyrrolidon. Simple designs of hydrophilic gels (films, tubes) for the in vitro studying of thromboresistant properties were manufactured. On the base of measurements of blood clotting time, concentration of prothrombin complex factors fibrinogen, heparin, thromboelastography, and thrombocyte adhesion onto hydrogel surface in blood contact; it was demonstrated that a hydrophilic gel consisting of 86 mol% of methyl methacrylate, 14 mol% of N-vinylpyrrolidon and 0.652 mol% of hydrolysed N-vinylpyrrolidon has optimum thromboresistant properties. Thromboresistant was studied in the dogs during 44 operations, in which both the aorta and peripheral vessels replaced by polypropylene prostheses or by Lavsan, modified by the addition of hydrophilic gels, were applied. It was shown that hydrophilic gels decrease thrombogenesis and promote rapid endothelialization and periprosthetic tissue vascularization.

Animals↗
PubMedDate not supplied

Thromboxane B2 blood levels and incipient system clotting in heparin free hemodialysis.

Clotting of the extracorporal system is the main complication of heparin free hemodialysis performed in patients with an increased risk of bleeding. The authors compared thromboxane B2, platelet factor 4, beta-thromboglobulin, and thromboelastography in systemic blood as markers of thrombogenicity during hemodialysis in eight patients with an increased risk of bleeding. Measurements were performed during hemodialysis with and without heparin. Thromboxane B2 levels in centrifuged blood were evaluated by an 125I assay system using a special extraction with mini-columns and magnetic separation (normal 32-64 pg/ml). At the onset of hemodialysis, thromboxane B2 concentrations in the inflow arterial blood line were lower than normal (30 +/- 23 pg/ml). Thromboxane B2 increased (97 +/- 105 versus 40 +/- 26 pg/ml) and was significantly higher during heparin free hemodialysis than during hemodialysis with heparin (p = 0.01, Wilcoxon matched pairs signed rank test). The highest values were observed in 5 cases with signs of clotting (152 +/- 122 pg/ml). Among the investigated parameters, thromboxane B2 proved to be the most significant serum parameter correlated with platelet activation and the consequently increased risk of incipient clotting during heparin free hemodialysis.

Aged↗
PubMed1995

Coagulation activation by MC28 fibrosarcoma cells facilitates lung tumor formation.

Tumor cells interact with the hemostatic system in various ways and may thus influence malignant growth and spread. MC28 fibrosarcoma cells possess a potent procoagulant activity (PCA) and form lung tumors following intravenous injection. The aim of this work was to study the relationship between PCA, intravascular coagulation and lung seeding in the MC28 model. MC28 cells were injected into control, warfarinized and heparinized hooded Lister rats. Coagulation changes were monitored by thromboelastography (TEG) and Sonoclot analysis (SA), lung fibrin formation by light and electron microscopy, tumor seeding by macroscopic counting and tumor cell and platelet deposition in the lungs by radiolabelling. PCA was measured by chromogenic assay. MC28 PCA was characterized as a tissue factor-factor VIIa complex that probably arose during cell culture or disaggregation of solid tumors. Injection of tumor cells caused marked coagulopathy and was rapidly (within 30 min) followed by fibrin deposition in the lungs and accumulation of radiolabelled platelets. Heparin and warfarin significantly reduced lung seeding (p < 0.001) and reduced retention of radiolabelled tumor cells in the pulmonary circulation (p < 0.01). Inhibition of cellular PCA by prior treatment with concanavalin A markedly reduced intravascular coagulation and lung seeding. We conclude that MC28 cells cause intravascular coagulation as a direct result of their procoagulant activity. The data suggest that tumor cells form complexes with platelets and fibrin which are retained in the lungs long enough for extravasation and seeding to occur.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Influence of circulating D-dimer levels on assays of fibrinogen.

The influence of circulating D-dimer levels on two different assays for fibrinogen was studied in 31 normal female subjects, 18 late pregnant subjects, 8 male subjects with acute myocardial infarction (AMI) and 9 subjects with unstable angina (UA). Both functional and chemical methods for fibrinogen showed significant correlation (r = 0.8171; P < 0.001). However, values for fibrinogen were significantly lower using the functional method in normal females, AMI and UA patients with mean (SD) ratios of 0.88 (0.11), 0.78 (0.17) and 0.84 (0.09) respectively as compared to the chemical assay method. In late pregnancy this was not observed with a mean ratio of 1.09 (0.22) obtained between the two methods. The D-dimer level in normal subjects was mean 194 (95.3) ng/ml whilst in late pregnancy, in AMI and UA, the levels were significantly elevated at 1093 (1034), 382 (216) and 1056 (708) ng/ml respectively. Significant correlation between fibrinogen and D-dimer levels was observed only in AMI and UA patients but not in late pregnancy. In 3 patients with AMI undergoing thrombolysis, no functional fibrinogen was detectable for the first 12 h following intravenous streptokinase (SK) despite the presence of chemically detectable fibrinogen with values of 13% to 30% of pre-treatment levels and evidenced by lytic states evaluated by thromboelastography (TEG). Grossly elevated D-dimer levels of between 25 x 10(3) and over 100 x 10(3) ng/ml were present during this time. Functional fibrinogen was detectable by 24 h following SK therapy but its level in relation to fibrinogen detected chemically remained depressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Observation of coagulation change during induced hypotensive anesthesia and autologous plasma transfusion.

Coagulation change was studied in 16 adult female patients undergoing radical hysterectomy with BPLND surgery. None had preoperative alterations in coagulation or liver function and was receiving anticoagulant or antiplatelet medication. Sixteen ASA class I-II were divided into 2 groups randomly with eight patients in each group. One group accepted autologous plasma transfusion near the end of surgery, the other group did not. Autologous plasma was retrieved by plasma saver post induction of anesthesia. Every patient received induced hypotensive anesthesia during the operation. Whole blood coagulation status was quantitated by using thromboelastography (TEG). Blood samples for TEG were obtained before induction of anesthesia, after closure of peritoneum, and 2 hours post autologous plasma transfusion or 2 hours post peritoneum closure. Most parameters measured by TEG showed improved coagulation status in autologous plasma transfusion group. We concluded that coagulation change was minimal during induced hypotension, and improved coagulation was obtained 2 hours post autologous plasma transfusion during radical hysterectomy with BPLND surgery.

Adult↗
PubMed1994

Effect of dried ginger on human platelet function.

Eight healthy male volunteers took part in a randomised double blind study of the effects of 2 g dried ginger or placebo capsules on platelet function. Bleeding time, platelet count, thromboelastography and whole blood platelet aggregometry were performed before, 3 h, and 24 h after the capsules. There were no differences between ginger and placebo in any of the variables measured. It is concluded that the effect of ginger on thromboxane synthetase activity is dose dependent, or only occurs with fresh ginger, and that upto 2 g of dried ginger is unlikely to cause platelet dysfunction when used therapeutically.

Adult↗
PubMed1993

Effects of continuous wave and pulsed laser on blood coagulation. An in vitro thromboelastographic study.

Besides being thrombogenic, lasers may have direct adverse effects on different constituents of blood itself, when used intraluminally in angioplasty. This pilot study was therefore designed to examine the effect of continuous wave (CW Nd: YAG) and pulsed wave (XeCl excimer) laser irradiation on whole blood coagulation and fibrinolysis in vitro using thromboelastography (TEG). TEG showed shortened reaction and coagulation times after three and six seconds with 10 W of continuous wave laser irradiation of 10 ml of blood. The clot formation rate and maximal amplitude were decreased with CW laser and the plasma clot lysis at one hour was significantly increased (P < 0.05). The effect of the pulsed wave laser was less pronounced. The exposure of whole blood to laser irradiation accelerated coagulation and enhanced fibrinolysis. The clinical significance of the findings is to be settled since the thrombogenicity of lasers is mainly caused by their effect on the vessel wall and thereby the on platelet-wall interaction.

Angioplasty, Laser↗
PubMed1993

Infusion of autologous platelet rich plasma does not reduce blood loss and product use after coronary artery bypass. A prospective, randomized, blinded study.

Prior nonblinded studies have suggested dramatic hemostatic effects and decreased plasma after cardiopulmonary bypass. Platelet rich plasma (8 to 10 ml/kg total body weight) was obtained (Haemonetics Plasma Saver; Haemonetics Corp., Natick, Mass.) from 51 patients undergoing primary coronary artery bypass grafting before heparinization. After double-blinded randomization, the platelet rich plasma was reinfused immediately in the control group or after heparin reversal in the treatment group. Homologous blood product usage, blood loss, and the surgeon's intraoperative subjective assessment of coagulation were evaluated. Additionally, thromboelastography, prothrombin time, partial thromboplastin time, activated clotting time, fibrinogen, platelet counts, and hematocrit values were evaluated before the operation, after heparin reversal, after infusion of platelet rich plasma or control solution, and 2 hours after infusion. The surgeon's subjective assessment of coagulation was not different between control and treatment groups (p = 0.78). According to specific predetermined transfusion guidelines, no statistically significant differences were found in the use of whole blood (p = 0.07), packed red blood cells (p = 0.62), platelets (p = 0.11), total units of blood products (p = 0.45), or in the percentage of patients receiving transfusions (control group 70%, treatment group 71%, p = 0.97). Cumulative amount of blood shed through the chest tube was not significantly different between the groups at any interval but tended toward significance at 4, 6, and 12 hours (p = 0.09, 0.07, and 0.09). The prothrombin time immediately after reinfusion of platelet rich plasma was significantly lower in the treatment group (p = 0.03), but all other laboratory studies were similar at each time interval. Infusion of platelet rich plasma after cardiopulmonary bypass in patients having uncomplicated primary coronary artery bypass grafting has minimal effects on the surgeon's assessment of coagulation, total transfusion requirements, mediastinal drainage, and laboratory studies of coagulation.

Aged↗
PubMed1979

An experimental study on the effect of plasma expanders on blood coagulability.

The effect of various plasma expanders on blood coagulation was studied using the thromboelastography (TEG). Solutions of 5, 10, 20, and 50% concentration of each expander (6% low molecular weight hydroxyethyl-starch (6% Hespander), 3% dextran-40, 6% high molecular weight hydroxyethyl-starch (6 HES), and 6% dextran-70) or solvent (lactated Ringer solution and normal saline) in blood were prepared and their coagulability was examined by TEG. In the low molecular weight plasma expanders (6% Hespander and 3% dextran-40), in general, the coagulability decreased when the concentration was increased. In the high molecular weight plasma expanders (6 HES and 6% dextran-70), the coagulability increased slightly at low and high concentrations and the coagulability was reduced. As a conclusion, at clinically used concentrations of less than 20% in blood, changes in the TEG of the plasma expanders are minimum and have no clinical significance.

Blood Coagulation↗
PubMed1995

[Traumatic emergencies and hemostasis].

The occurrence of bleeding in trauma patients is a life-threatening problem which can be explained by different mechanisms. The infusion of cristalloids, colloids, packed red blood cells, or even fresh frozen plasma is very rarely responsible for bleeding but it can contribute to dilute the patient's platelet pool, and especially dilutional thrombocytopenia is the first cause of bleeding after massive transfusion. Blood coagulation factor activity is decreased after a massive fluid infusion is performed but it has to reach a dramatically low plasma level in order to induce troubles. It has to be emphasized that colloids and especially dextrans can impair the patient's haemostasis by interfering the same way with the factor VIII-von Willebrand complex and fibrin formation. Gelatins do not interfere with platelets or with the coagulation system. A third mechanism that can explain the strong link between haemostasis and haemodilution is the haemostatic role of red cells. It has been shown in experimental models that red cells play a definite function in promoting platelet accretion on the damaged vessel surface. Higher values of haematocrit (Ht) are responsible for a better platelet adhesion On the opposite, platelet adhesion decreases when low values of Ht (< 20%) are reached. Hypothermia can also impair platelet function and worsen the bleeding. A simplified monitoring of haemostasis can be proposed with platelet count, whole blood coagulation clotting time, immediately available activated partial thromboplastin time and prothrombin time with bedside portable monitors and thromboelastography. Haematocrit and body temperature have to be monitored as well.

Blood Coagulation Disorders↗
PubMedDate not supplied

[The effect of the quaternary ammonium salt of conidine oligomer-25 (QAS CO-25) on the activity of prothrombin complex factors].

Quaternary ammonium salt of oligomer-25 conidine (QAS O-25C) was used for regulation of hypocoagulation effect of Syncumar--anticoagulant of indirect type of action. The experiments were carried out on male rats. Experimental methods included thromboelastography, determination of thromboplastin time (after Quick) and determination of activity of single coagulation factors. It was shown that injection of QAS O-25C reliably do not affect blood coagulation. The combined action of QAS O-25C and Syncumar resulted in a twofold increase in the activity of factors IX and X within 24 h after the injection and in complete recovery after 48 h. After Syncumar injection per os we observed deep-hypercoagulation which was maintained even within 48 after the injection. The effect of QAS O-25C modulating the Syncular anticoagulant activity is probably connected with intensification of protein synthesis in the liver and, specifically, with an increase in the yield of active precursors of the factors of prothrombin complex.

Acenocoumarol↗