Effect of thymalin and heterotransfusion on blood coagulation and fibrinolysis in thymectomized rats

Experiments on rats have shown that thymectomy brings about the development of hypercoagulation and inhibition of fibrinolysis. Heterotransfusion is accompanied by hypocoagulation and stimulation of fibrinolysis in both intact and thymectomized rats. At the same time fibrinolysis in thymectomized rats is stimulated to a lesser degree than in intact animals. Preinjection into thymectomized rats of the thymus low-molecular factor thymaline over one week does not only make blood coagulation and fibrinolysis return to normal but also leads to adequate changes in the hemostatic system in response to heterotransfusion.     

Changes in the hemostatic function of muscle tissue in phylogenesis

Studies have been made on coagulating and fibrinolytic activity of muscle tissue from various animals (earthworm, clam, car, frog, pigeon, rat). It was shown that extracts from muscles of these animals contain activators and inhibitors of hemocoagulation and fibrinolysis, exhibiting also antiheparin activity. It is concluded that progressive development of hemostatic function of muscle tissue involves the decrease in anticoagulating activity and the increase of thromboplastic activity.     

Dependence of haemostasis system response from initial blood coagulation activity under total joints replacement

Effect of the initial state of the plasma hemostasis on the hemocoagulation changes after the total arthroplasty surgery was studied in 100 patients with osteoarthritis. Indicators of coagulation, fibrinolysis, and physiological anticoagulants were determined before and after completion of the surgery, at days 1, 3, 7, and 13-14 postoperatively. Increased coagulation activity befor surgery enhanced blood clotting within three days after the surgery. Enhanced consumption of physiological anticoagulants reduced the ability to recover their level a week after arthroplasty. The raised activity of the fibrinolysis inhibitor retained the effect during three postoperative days. Initial abnormalities in plasma hemostasis enhance blood coagulation dysfunction caused by surgical intervention on the large joints.     

Role of the Initial State in the Response of the Hemostasis System to Heavy Exercise

The authors studied changes in the hemostasis system while working on bicycle ergometer with and without manifest fatigue. The direction and value of the change in blood coagulation time and natural lysis of a blood clot under the influence of exercise correlated with the initial state of the system. Work mostly inhibited blood coagulation when its initial values high and accelerated it when they were low. When fibrinolytic activity of blood at rest was low, it was stimulated; when it was high, it was inhibited. A similar relation between the initial values and response to exercise characterized several indices of the plasma link of hemostasis, such as plasma coagulation time, fibrinogen concentration, activity of antithromboplastins and antithrombin III, and euglobulin clot lysis time. Fatigue led to more manifest individual changes in most of the indices of coagulant, anticoagulant, and fibrinolytic activity of blood. As a rule, the value of correlation between the initial state and changes in the indices increased. This suggests strengthening of the role of the initial state in the hemostasis system response to exercise.     

The Role of the Initial State in the Response of the Hemostasis System to Double Exercise

Changes in the hemostasis system were studied in males with a high working capacity when they performed the same dosed double stress exercise test with moderate (N ₁ = 1.4 W/kg, t ₁ = 6.93 min) and high (N ₂ = 2.96 W/kg, t ₂ = 3.15 min) intensity with a 1-h interval between. The direction and the magnitude of changes in the main variables of blood coagulation, anticoagulants, and blood and plasma fibrinolytic activity under the influence of exercise were shown to correlate with the initial state of the system. At high values of the variables before the beginning of muscular activity, work results in their decrease, and at low values, in their increase. Previous work increases the dependence of changes in blood coagulation on its initial value upon repeat exercise, without influencing the relationship between alterations in the fibrinolytic activity of whole blood and its value before exercise. Double loading reveals closer relations between the initial values of blood coagulation, anticoagulants, and fibrinolysis and their changes due to work. It was concluded that, on the basis of the correlations presented, it is possible to predict with high probability the direction and the magnitude of hemocoagulant and fibrinolytic response to physical activity in the group of subjects studied.     

Functional activity of vasopressin analog desglycinamide-arginine-vasopressin

Original and published data on the functional activity of neurohypophyseal hormone vasopressin and its analog DGAVP were analyzed with a particular focus on the pattern of the peptide effect on the hemostatic system. The effects of the natural hormone and its synthetic analog on some indices of coagulation and fibrinolysis were compared. The effects of the peptides on the behavioral responses as well as on memory processes of animals are analyzed.     

Effects of mammal submandibular gland glycoderivatives on human hemostatic system

The aim of this study was to investigate the effects of glycoconjugate components extracted from the submandibular glands of four mammal species (rat, mouse, rabbit, hare) on human hemostatic system. The following analyses were performed: thromboelastography and hemocoagulation screening tests (Thrombin Time, Prothrombin Time, Partial Thromboplastin Time). Findings showed that all glycoconjugates induce modifications of fibrin clot formation time, modulus of elasticity and some hemocoagulation tests (TT, PTT). The anticoagulant effects were of inhibitory type.     

Heterogeneous activity of rodent and lagomorph parotid gland extracts on the hemocoagulation process

Anticoagulant properties of parotid glands belonging to four species of mammals (rat, mouse, rabbit and hare) were investigated on the hemostatic system of human being. Heterogeneous effects of the glycoconjugates extractable from different species were demonstrated by means of thromboelastography and hemocoagulation screening tests. In fact, glycoconjugates isolated from the rodent (rat and mouse) parotid glands changed all the thromboelastographic parameters and the hemocoagulation tests (Thrombin Time, Prothrombin Time, Partial Thromboplastin Time). Glycoconjugates extracted from the rabbit parotid gland strongly affected the thromboelastogram parameters in addition to the Partial Thromboplastin Time. Finally, glycoderivatives obtained from the hare parotid gland only influenced the Partial Thromboplastin Time.     

Oxidative stress in haemostasis

The normal hemostatic mechanisms consist of a balance between hemorrhage and thrombosis that is achieved through the interaction of the blood vessels, blood platelets, the coagulation and fibrinolytic factors. The vascular endothelium sustains the balance between prevention and stimulation of platelet activation, thrombogenesis and fibrinolysis and between vasoconstriction and vasodilatation. Endothelial dysfunction associated with different cardiovascular diseases is related to the local formation of reactive oxygen/nitrogen species, mainly peroxynitrite that is produced in a rapid reaction between nitric oxide and superoxide anion. Reactive oxygen/nitrogen species induce changes in the structure and function in hemostatic elements. Proteins and lipids are major initial targets in endothelial cells, blood platelets and plasma. Reaction of reactive oxygen species and nitrogen species, including peroxynitrite, with cellular proteins can lead to nitration of aromatic amino acid residues, oxidation of thiol groups and conversion of some amino acid residues into carbonyl derivative. Oxidative/nitrative modifications of platelet proteins may induce changes of their signaling and haemostatic function (activation). Peroxynitrite also causes oxidation and nitration of fibrinogen--a key protein in coagulation cascade and plasminogen (the main protein of fibrinolysisprocess) changing their hemostatic functions. Oxidative/nitrative modifications of different components of haemostasis system have been observed in several cardiovascular diseases.     

Efficiency of thermoregulatory system in man under endogenous and exogenous heat loads

The aim of the present work was to estimate the dynamics and efficiency (eta sw) of sweating, and thermoregulatory index (TI) defined as a ratio of heat loaded the body to the heat removed to the environment. In the first part of this work 22 men exercised with an intensity of 50% VO2 max. in 22 degrees C, 16 men were exposed to 40 degrees C at rest, and 9 men exercised at the level of 50% VO2 max. at 30 degrees C. In the second part, 8 men and 8 women were exposed to 40 degrees C before and after dehydration (1% of body mass, approximately), 8 men exercised at 23 degrees C before and after hyperhydration (35 ml/kg of body mass) and 22 men exercised before and after 3 months of endurance training. Body heat balance, rectal (Tre), tympanic (Tty) and mean skin (Tsk) temperatures were measured in all subjects. TI was greater during simultaneous (0.84) than during separate endo- (0.76, p less than 0.01) or exogenous (0.67, p less than 0.001) heat loads. The respective values of eta sw were 0.82; 0.57 (p less than 0.001) and 0.78 (p less than 0.001). No difference in TI was found between men and women. Dynamics of sweating was greater in men but efficiency of sweating was greater in women. Dehydration before heat exposure decreased both dynamics of sweating and TI but it increased eta sw in men. As a result Tre was greater in dehydrated (0.45 degrees C) than in normally hydrated men (0.31 degrees C, p less than 0.002). Dehydration did not affect the measured variables in women. Hyperhydration of exercising men caused an increase in TI from 0.72 to 0.82 (p less than 0.05) and in eta sw from 0.57 to 0.81 (p less than 0.01). In men exercising after endurance training the onset of sweating was shortened from 4.0 to 0.9 min (p less than 0.002). TI increased from 0.76 to 0.89 (p less than 0.001), eta sw increased from 0.57 to 0.74 (p less than 0.02) whereas Tty was lower (1.10 and 0.58 degrees C, p less than 0.001, respectively). It is concluded that dynamics and efficiency of sweating, as well as the thermoregulatory index depend on the type of heat load. Men and women tolerate dry heat equally well. Dehydration changes thermoregulatory function in men but not in women. Hyperhydration before exercise and particularly endurance training increase tolerance of endogenous heat.(ABSTRACT TRUNCATED AT 400 WORDS)     

Discrepant Fibrinolytic Response in Plasma and Whole Blood during Experimental Endotoxemia in Healthy Volunteers

Background

Sepsis induces early activation of coagulation and fibrinolysis followed by late fibrinolytic shutdown and progressive endothelial damage. The aim of the present study was to investigate and compare the functional hemostatic response in whole blood and plasma during experimental human endotoxemia by the platelet function analyzer, Multiplate and by standard and modified thrombelastography (TEG).

Methods

Prospective physiologic study of nine healthy male volunteers undergoing endotoxemia by means of a 4-hour infusion of E. coli lipopolysaccharide (LPS, 0.5 ng/kg/hour), with blood sampled at baseline and at 4 h and 6 h. Physiological and standard biochemical data and coagulation tests, TEG (whole blood: TEG, heparinase-TEG, Functional Fibrinogen; plasma: TEG±tissue-type plasminogen activator (tPA)) and Multiplate (TRAPtest, ADPtest, ASPItest, COLtest) were recorded. Mixed models with Tukey post hoc tests and correlations were applied.

Results

Endotoxemia induced acute SIRS with increased HR, temperature, WBC, CRP and procalcitonin and decreased blood pressure. It also induced a hemostatic response with platelet consumption and reduced APTT while INR increased (all p<0.05). Platelet aggregation decreased (all tests, p<0.05), whereas TEG whole blood clot firmness increased (G, p = 0.05). Furthermore, during endotoxemia (4 h), whole blood fibrinolysis increased (clot lysis time (CLT), p<0.001) and Functional Fibrinogen clot strength decreased (p = 0.049). After endotoxemia (6 h), whole blood fibrinolysis was reduced (CLT, p<0.05). In contrast to findings in whole blood, the plasma fibrin clot became progressively more resistant towards tPA-induced fibrinolysis at both 4 h and 6 h (p<0.001).

Conclusions

Endotoxemia induced a hemostatic response with reduced primary but enhanced secondary hemostasis, enhanced early fibrinolysis and fibrinogen consumption followed by downregulation of fibrinolysis, with a discrepant fibrinolytic response in plasma and whole blood. The finding that blood cells are critically involved in the vasculo-fibrinolytic response to acute inflammation is important given that disturbances in the vascular system contribute significantly to morbidity and mortality in critically ill patients.     

A prothrombin activator (Lopap) modulating inflammation, coagulation and cell survival mechanisms

A severe hemorrhagic syndrome produced by contact with Lonomia obliqua caterpillars has become epidemic in southern Brazil. A significant thrombin production with intense consumption of fibrinogen and high D-dimer production indicates a consumption coagulopathy and secondary fibrinolysis in patients. Lopap is a single-chain 69kDa serine protease isolated from the crude extract of L. obliqua bristles. Experiments in mice showed that the purified protein, similar to the crude extract, causes uncoagulable blood by fibrinogen depletion. In order to characterize the effects of Lopap on cells involved with hemostatic system, we performed experiments using human umbilical vein endothelial cells (HUVECs). Our results show that Lopap exerts a direct effect on endothelial cells by increasing the liberation of molecules involved in the regulation of vascular tone, inhibiting platelet activation and chemotaxis, apart from inducing the expression of cell adhesion molecules which participate in inflammatory responses. The release or new synthesis of mediators involved in coagulation as von Willebrand factor and tissue factor, or in fibrinolysis as tissue plasminogen activator, was not affected by Lopap. Also our results demonstrated that Lopap acts on cell survival of HUVECs, regulating the expression of molecules as NO and avoiding cell death.     

Apolipoprotein polymorphism is associated with pro-thrombotic profile in non-demented dyslipidemic subjects

Apolipoprotein gene polymorphism has an important role in lipid metabolism and in the development of cerebro- and cardio-vascular disease (CCVD), including dementia. Dyslipidemia and hemostatic abnormalities are key risk factors associated with athero-sclerotic events preceding CCVD. The aim of this study was to evaluate the possible relationships of various apolipoprotein-species with hemostatic parameters and cognitive function. Lipid profile, gene polymorphism, coagulation markers, and mini-mental state examination (MMSE) scores were assessed in 109 dys-lipidemic subjects and in 107 healthy control volunteers. Thrombin-activatable fibrinolysis inhibitor (TAFI) plasma levels were significantly higher in apolipoprotein-E2 (apoE2) patients when compared to other apoE forms. The apoA5 -1131T>C polymorphism was associated with elevated D-dimer concentration in dyslipidemic TT homozygous individuals. MMSE did not correlate with lipid or coagulation profile. These data suggest that apoE and apoA5 variants have an effect on hemostatic parameters, but they neither influence nor predict cognitive performance in non-demented individuals.     

Protective roles for fibrin, tissue factor, plasminogen activator inhibitor-1, and thrombin activatable fibrinolysis inhibitor, but not factor XI, during defense against the gram-negative bacterium Yersinia enterocolitica

Septic infections dysregulate hemostatic pathways, prompting coagulopathy. Nevertheless, anticoagulant therapies typically fail to protect humans from septic pathology. The data reported in this work may help to explain this discrepancy by demonstrating critical protective roles for coagulation leading to fibrin deposition during host defense against the Gram-negative bacterium Yersinia enterocolitica. After i.p. inoculation with Y. enterocolitica, fibrinogen-deficient mice display impaired cytokine and chemokine production in the peritoneal cavity and suppressed neutrophil recruitment. Moreover, both gene-targeted fibrinogen-deficient mice and wild-type mice treated with the anticoagulant coumadin display increased hepatic bacterial burden and mortality following either i.p. or i.v. inoculation with Y. enterocolitica. Mice with low tissue factor activity succumb to yersiniosis with a phenotype similar to fibrin(ogen)-deficient mice, whereas factor XI-deficient mice show wild-type levels of resistance. Mice deficient in plasminogen activator inhibitor-1 or thrombin-activatable fibrinolysis inhibitor display modest phenotypes, but mice deficient in both plasminogen activator inhibitor-1 and thrombin-activatable fibrinolysis inhibitor succumb to yersiniosis with a phenotype resembling fibrin(ogen)-deficient mice. These findings demonstrate critical protective roles for the tissue factor-dependent extrinsic coagulation pathway during host defense against bacteria and caution that therapeutics targeting major thrombin-generating or antifibrinolytic pathways may disrupt fibrin-mediated host defense during Gram-negative sepsis.     

The influence of cytostatic treatment on the initiation of plasma coagulation in patients with neoplastic diseases

The above described changes in the haemostatic system in acute leukemias are well known and underlined by many authors [1, 5, 6, 9]. It should be stressed that the results of particular nonspecific hemostatic tests in some patients may be within the normal range in spite of significant alterations in the activity of some blood coagulation factors and the presence of hemorrhagic symptoms. In the observations of some authors the factor VIII level is distinctly increased in the majority of acute leukemic cases, whereas the vitamin K-dependent blood coagulation factors show a low activity in some patients [6, 9]. It is not easy to interpret the different behaviour of the factor XI and XII level especially before antileukemic treatment. In 3/4 of all studied cases the factor XI activity was low, whereas the factor XII level was high in 1/4 of patients above the normal range. It may be that there is a specific inhibitor against the factor XI that is produced in acute leukemia. It must be stressed that the level of factor XI shows normal values during hematological remission.     

Activated protein C, a protein at the crossroads between coagulation and inflammation

Sepsis is defined as a systemic response to infection, characterized by an intense inflammatory response linked to coagulation activation and fibrinolysis inhibition, two processes which are intimately associated. In a field where mortality remains very high, administration of activated protein C, a physiological coagulation inhibitor with cytoprotective properties, has demonstrated its effectiveness and was able to reduce mortality. Protein C belongs to a system that involves plasma proteins and endothelial cell receptors. In addition to well documented effects on coagulation and fibrinolysis, activated protein C exhibits anti-inflammatory, anti-apoptotic but also anti-histone activities. Indeed, a recent study focusing on the cytoprotective effects of activated protein C showed that extracellular histones are released during severe sepsis and may participate in the pathophysiology of severe sepsis. These histones appear to be new targets of activated protein C.     

Effect of the enzyme preparation longolytin on fibrinolysis in animals

It has been established that fibrinolytically active enzyme longolytine isolated from the culture fluid of the saprophyte fungus Arthrobotrys longa at intravenous injection favours the prolonged increase of the plasma fibrinolytic properties as well as activation of endogenic plasminogen. Maximum values of fibrinolytic activity have been marked in 5 and 30 min after enzyme intravenous injection. The plasminogen activity is high in 120 min. The fibrinolysis indexes--fibrinolytic activity of the euglobulin fraction and amount of plasminogen activator--in 3,5 and 5 times higher than in vitro at intravenous injection. The activation of coagulation system does not occur.     

Liver Transplantation in Man—IV,Haemorrhage and Thrombosis

Blood coagulation and fibrinolytic factors have been measured in 13 patients treated by liver transplantation. During operation intravascular coagulation and fibrinolysis were increased, but seldom to a degree which would cause abnormal bleeding. Measurement of the catabolism of radioactive fibrinogen showed that increased intravascular coagulation continued for long periods after the operation. Despite secondarily increased fibrinolysis, there was a high incidence of thrombosis. Treatment with anticoagulants or with fibrinolysis inhibitors may be valuable in these patients.     

Absence of thrombin-activatable fibrinolysis inhibitor protects against sepsis-induced liver injury in mice

Thrombin-activatable fibrinolysis inhibitor (TAFI), also known as carboxypeptidase R, has been implicated as an important negative regulator of the fibrinolytic system. In addition, TAFI is able to inactivate inflammatory peptides such as complement factors C3a and C5a. To determine the role of TAFI in the hemostatic and innate immune response to abdominal sepsis, TAFI gene-deficient (TAFI-/-) and normal wild-type mice received an i.p. injection with Escherichia coli. Liver TAFI mRNA and TAFI protein concentrations increased during sepsis. In contrast to the presumptive role of TAFI as a natural inhibitor of fibrinolysis, TAFI-/- mice did not show any difference in E. coli-induced activation of coagulation or fibrinolysis, as measured by plasma levels of thrombin-anti-thrombin complexes and D-dimer and the extent of fibrin depositions in lung and liver tissues. However, TAFI-/- mice were protected from liver necrosis as indicated by histopathology and clinical chemistry. Furthermore, TAFI-/- mice displayed an altered immune response to sepsis, as indicated by an increased neutrophil recruitment to the peritoneal cavity and a transiently increased bacterial outgrowth together with higher plasma TNF-alpha and IL-6 levels. These data argue against an important part for TAFI in the regulation of the procoagulant-fibrinolytic balance in sepsis and reveals a thus far unknown role of TAFI in the occurrence of hepatic necrosis.