scholarly journals Reduction of salivary tissue factor (thromboplastin) activity by warfarin therapy

Blood ◽  
1979 ◽  
Vol 53 (3) ◽  
pp. 366-374 ◽  
Author(s):  
LR Zacharski ◽  
R Rosenstein
Keyword(s):  
Tissue Factor ◽  
Vitamin K ◽  
Coagulation Factors ◽  
Human Saliva ◽  
Factor Vii ◽  
Clotting Factor ◽  
Activate Factor ◽  
Total Protein Content ◽  
Factor X ◽  
Clotting Factors

Abstract The coagulant of normal human saliva has been identified as tissue factor (thromboplastin, TF) by virtue of its ability to cause rapid coagulation in plasmas deficient in first-stage coagulation factors and to activate factor x in the presence of factor VII and by virtue of the fact that its activity is expressed only in the presence of factor VII and is inhibited by an antibody to TF. The TF is related to cells and cell fragments in saliva. Salivary TF activity has been found to be significantly reduced in patients taking warfarin. The decline in TF activity during induction of warfarin anticoagulation occurs during the warfarin-induced decline in vitamin-K-dependent clotting factor activity, as judged by the prothrombin time. The decrease in TF activity is not related to a reduction in salivary cell count or total protein content or to a direct effect of warfarin on the assay. It is hypothesized that the mechanism by which warfarin inhibits TF activity may be related to the mechanism by which it inhibits expression of the activity of the vitamin-K-dependent clotting factors. Inhibition of the TF activity may be involved in the antithrombotic effect of warfarin.

scholarly journals Reduction of salivary tissue factor (thromboplastin) activity by warfarin therapy

Blood ◽  
1979 ◽  
Vol 53 (3) ◽  
pp. 366-374 ◽  
Author(s):  
LR Zacharski ◽  
R Rosenstein
Keyword(s):  
Tissue Factor ◽  
Vitamin K ◽  
Coagulation Factors ◽  
Human Saliva ◽  
Factor Vii ◽  
Clotting Factor ◽  
Activate Factor ◽  
Total Protein Content ◽  
Factor X ◽  
Clotting Factors

The coagulant of normal human saliva has been identified as tissue factor (thromboplastin, TF) by virtue of its ability to cause rapid coagulation in plasmas deficient in first-stage coagulation factors and to activate factor x in the presence of factor VII and by virtue of the fact that its activity is expressed only in the presence of factor VII and is inhibited by an antibody to TF. The TF is related to cells and cell fragments in saliva. Salivary TF activity has been found to be significantly reduced in patients taking warfarin. The decline in TF activity during induction of warfarin anticoagulation occurs during the warfarin-induced decline in vitamin-K-dependent clotting factor activity, as judged by the prothrombin time. The decrease in TF activity is not related to a reduction in salivary cell count or total protein content or to a direct effect of warfarin on the assay. It is hypothesized that the mechanism by which warfarin inhibits TF activity may be related to the mechanism by which it inhibits expression of the activity of the vitamin-K-dependent clotting factors. Inhibition of the TF activity may be involved in the antithrombotic effect of warfarin.

Increased Activity of Vitamin K-Dependent Clotting Factors in Human Hyperlipoproteinaemia – Association with Cholesterol and Triglyceride Levels

1977 ◽  
Vol 38 (02) ◽  
pp. 0465-0474 ◽  
Author(s):  
M Constantino ◽  
C Merskey ◽  
D. J Kudzma ◽  
M. B Zucker
Keyword(s):  
Vitamin K ◽  
Plasma Lipids ◽  
Coagulation Factors ◽  
Clotting Factor ◽  
Factor X ◽  
Clotting Factors ◽  
Blood Coagulation Factors ◽  
Cholesterol Levels ◽  
Type V ◽  
Increased Activity

SummaryLevels of blood coagulation factors, cholesterol and triglyceride were measured in human plasma. Prothrombin was significantly elevated in type Ha hyperlipidaemia; prothrombin and factors VII, IX and X in type lib; and prothrombin and factors VII and IX in type V. Multiple regression analysis showed significant correlation between the levels of these plasma lipids and the vitamin K-dependent clotting factors (prothrombin, factors VII, IX and X). Higher cholesterol levels were associated with higher levels of prothrombin and factor X while higher triglyceride levels were associated with higher levels of these as well as factors VII and IX. Prothrombin showed a significant cholesterol-triglyceride interaction in that higher cholesterol levels were associated with higher prothrombin levels at all levels of triglyceride, with the most marked effects in subjects with higher triglyceride levels. Higher prothrombin levels were noted in subjects with high or moderately elevated (but not low) cholesterol levels. Ultracentrifugation of plasma in a density of 1.21 showed activity for prothrombin and factors VII and X only in the lipoprotein-free subnatant fraction. Thus, a true increase in clotting factor protein was probably present. The significance of the correlation between levels of vitamin K-dependent clotting factors and plasma lipids remains to be determined.

scholarly journals Activation of human factor VII during clotting in vitro

Blood ◽  
1985 ◽  
Vol 65 (1) ◽  
pp. 218-226 ◽  
Author(s):  
LV Rao ◽  
SP Bajaj ◽  
SI Rapaport
Keyword(s):  
Tissue Factor ◽  
Glass Tube ◽  
Factor Vii ◽  
Clotting Factor ◽  
Activate Factor ◽  
Factor Xii ◽  
Factor X ◽  
Normal Plasma

Abstract We have studied factor VII activation by measuring the ratio of factor VII clotting to coupled amidolytic activity (VIIc/VIIam) and cleavage of 125I-factor VII. In purified systems, a low concentration of Xa or a higher concentration of IXa rapidly activated 125I-factor VII, yielding a VIIc/VIIam ratio of 25 and similar gel profiles of heavy and light chain peaks of VIIa. On further incubation, VIIa activity diminished and a third 125I-peak appeared. When normal blood containing added 125I- factor VII was clotted in a glass tube, the VIIc/VIIam ratio rose fivefold, and 20% of the 125I-factor VII was cleaved. Clotting normal plasma in an activated partial thromboplastin time (APTT) system yielded a VIIc/VIIam ratio of 25 and over 90% cleavage of 125I-factor VII. Clotting factor XII-deficient plasma preincubated with antibodies to factor X in an APTT system with added XIa yielded a VIIc/VIIam ratio of 19 and about 60% cleavage, which indicates that IXa, at a concentration achievable in plasma, can effectively activate factor VII. Clotting normal plasma with undiluted tissue factor yielded a VIIc/VIIam ratio of 15 to 20 and 60% cleavage of 125I-factor VII, whereas clotting plasma with diluted tissue factor activated factor VII only minimally. We conclude that both Xa and IXa can function as significant activators of factor VII in in vitro clotting mixtures but believe that only small amounts of factor VII may be activated in vivo during hemostasis.

scholarly journals Activation of human factor VII during clotting in vitro

Blood ◽  
1985 ◽  
Vol 65 (1) ◽  
pp. 218-226 ◽  
Author(s):  
LV Rao ◽  
SP Bajaj ◽  
SI Rapaport
Keyword(s):  
Tissue Factor ◽  
Glass Tube ◽  
Factor Vii ◽  
Clotting Factor ◽  
Activate Factor ◽  
Factor Xii ◽  
Factor X ◽  
Normal Plasma

We have studied factor VII activation by measuring the ratio of factor VII clotting to coupled amidolytic activity (VIIc/VIIam) and cleavage of 125I-factor VII. In purified systems, a low concentration of Xa or a higher concentration of IXa rapidly activated 125I-factor VII, yielding a VIIc/VIIam ratio of 25 and similar gel profiles of heavy and light chain peaks of VIIa. On further incubation, VIIa activity diminished and a third 125I-peak appeared. When normal blood containing added 125I- factor VII was clotted in a glass tube, the VIIc/VIIam ratio rose fivefold, and 20% of the 125I-factor VII was cleaved. Clotting normal plasma in an activated partial thromboplastin time (APTT) system yielded a VIIc/VIIam ratio of 25 and over 90% cleavage of 125I-factor VII. Clotting factor XII-deficient plasma preincubated with antibodies to factor X in an APTT system with added XIa yielded a VIIc/VIIam ratio of 19 and about 60% cleavage, which indicates that IXa, at a concentration achievable in plasma, can effectively activate factor VII. Clotting normal plasma with undiluted tissue factor yielded a VIIc/VIIam ratio of 15 to 20 and 60% cleavage of 125I-factor VII, whereas clotting plasma with diluted tissue factor activated factor VII only minimally. We conclude that both Xa and IXa can function as significant activators of factor VII in in vitro clotting mixtures but believe that only small amounts of factor VII may be activated in vivo during hemostasis.

Properties of Recombinant Human Thromboplastin that Determine Sensitivity to Vitamin K-Dependent Coagulation Factors.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 533-533
Author(s):  
Stephanie A. Smith ◽  
James H. Morrissey
Keyword(s):  
Ionic Strength ◽  
Vitamin K ◽  
Phospholipid Composition ◽  
Coagulation Factors ◽  
Factor Vii ◽  
Clotting Factor ◽  
Sensitivity Index ◽  
Clotting Factors ◽  
Individual Factor ◽  
Factor Deficiency

Abstract Patients undergoing oral anticoagulant therapy (OAT) with coumarins have reduced plasma levels of vitamin K-dependent clotting factors. The primary laboratory test for monitoring OAT is the prothrombin time (PT), in which clotting is initiated by tissue factor (TF). Clotting factors that contribute to the PT, and whose levels respond to OAT, are factor VII (FVII), factor X (FX), and prothrombin, although they are not suppressed to the same extent. Thromboplastin reagents (the source of TF activity in PT tests) can vary dramatically in their sensitivities to the effects of OAT. A calibration system, the International Sensitivity Index (ISI), is widely used to correct the PT for variable thromboplastin sensitivity, but discrepant responses by reagents of similar ISI have been reported. We have undertaken studies aimed at understanding which factors control the sensitivity of thromboplastin reagents, with a goal of creating “designer thromboplastins” whose sensitivities to specific clotting factors can be individually tailored. Thromboplastin reagents were prepared by reconstituting recombinant human TF into phospholipid vesicles containing varying amounts of phosphatidylcholine, phosphatidylserine (PS), and phosphatidylethanolamine (PE). Thromboplastins containing low levels of PS and high ionic strength had the highest sensitivity to OAT (i.e., lowest ISI). PE shifted the dose-response such that lower levels of PS were required to obtain the same ISI value. These studies demonstrate that multiple combinations of phospholipid composition and ionic strength can be used to produce reagents of identical ISI. We hypothesized that reagents of identical ISI values but different composition could have very different responses to changes in the levels of individual coagulation factors. Accordingly, thromboplastin reagents of varying composition were evaluated for their responses to deficiencies of FVII, FX and prothrombin. PT tests were performed using pooled normal plasma mixed with individual factor-depleted plasmas to yield 10%, 3%, 1% or 0.3% of the normal level of the specific clotting factor. Responses of thromboplastin reagents to individual factors were compared by plotting the clotting times obtained with these plasmas on log-log scales versus the percent factor level and fitting lines to the data by linear regression. Interestingly, altering the composition of the thromboplastin reagents dramatically and independently altered their sensitivities to individual clotting factors. For example, increasing ionic strength had no impact on the response to FVII, but markedly enhanced the response to prothrombin deficiency. Furthermore, the effect of changes in ionic strength on specific factors levels differed depending upon the phospholipid composition. These studies demonstrate that thromboplastin reagents of dissimilar composition but nearly identical ISI values can have very different sensitivities to deficiencies in FVII, FX, or prothrombin, so reagents of identical ISI do not necessarily respond to the factor deficiencies induced by OAT in an identical fashion. These studies evaluated samples with isolated individual factor deficiency, whereas patients on OAT have combined factor deficiency and therefore have more potential for discrepancy in PT responses between reagents. Controlling the responsiveness of thromboplastin reagents to deficiencies in individual clotting factors may therefore be desirable for monitoring OAT and for the other clinical diagnostic uses to which PT tests are commonly applied.

Montelukast - Its Immunomodulatory and Antiviral Action in COVID-19

2021 ◽  
Vol 8 (21) ◽  
pp. 1731-1732
Author(s):  
Prashant Ramesh Chakkarwar
Keyword(s):  
Tissue Factor ◽  
Inflammatory Cytokines ◽  
Factor Vii ◽  
Clotting Factor ◽  
Activate Factor ◽  
Cytokine Storm ◽  
Oak Ridge ◽  
Montelukast Sodium ◽  
Tnf Α ◽  
Pro Inflammatory Cytokines

Coronavirus disease-19 (COVID-19) is the deadliest pandemic that the whole world is facing today. COVID-19 is different from normal flu by its two lethal manifestations which includes deadly pneumonia which may lead to acute respiratory distress syndrome (ARDS) due to hyper-inflammation of alveolar tissues and pulmonary intravascular coagulopathy (PIC).1,2 It is noteworthy here to mention that both these lethal manifestations of COVID-19 are due to abnormally high levels of pro-inflammatory cytokines like interleukin (IL) - 1β, IL - 6, and tumour necrosis factor (TNF) - α, termed as “cytokine storm.”3,4 There is a certain link between pro-inflammatory cytokines like IL - 1β, IL - 6, and TNF - α and its pro-coagulatory influence on coagulation pathway mediated by tissue factor that binds and activate factor VII, leading to formation of tissue factor – VII a complexes which results in the activation of clotting factor X and IX.4 Recently the researchers in China and some European countries have found raised level of pro-inflammatory cytokines particularly IL - 6 in severe cases of COVID-19. They also found raised D-dimer, fibrinogen levels and prothrombin time in moderate to severe COVID-19 cases.5,6 Both of these lethal manifestations of COVID-19 – ARDS and PIC are linked to raised levels of pro-inflammatory cytokines, particularly, IL - 6. It is not very clear that the pro-inflammatory action of cytokines is mediated through leukotrienes as the biochemical assay for leukotrienes are not widely available but possibility of this probable mechanism cannot be ruled out. Hence, development of any molecule with ability to inhibit pro-inflammatory cytokines, particularly IL-6 may be able to tame the lethal nature of COVID-19, and may ultimately reduce the mortality of this deadly pandemic. Montelukast sodium is such molecule which has capacity to inhibit proinflammatory cytokines such as IL - 1β, IL - 6, and TNF - α.7 Montelukast sodium is leukotriene receptor antagonist that inhibits the cysteinyl leukotriene type-1 receptor. Leukotrienes modulate the production of pro-inflammatory cytokines.8 Its antagonist action on leukotriene receptors can inhibit the production of these pro-inflammatory cytokines. Even recent in silico study by Jacobson at Oak Ridge National Lab, was found that excess bradykinin production may be responsible for pulmonary, cardiac, neurological and nephrological lethal manifestations of COVID-19.9 Crimi et al.10 already found that Montelukast is effective to control bradykinin induced bronchoconstriction. Thus, theoretically, montelukast seems to be best molecule to deal with deadly manifestation of COVID-19 even if we go by cytokine storm hypothesis or bradykinin hypothesis.

scholarly journals Evidence for the presence of tissue factor activity on subendothelium

Blood ◽  
1989 ◽  
Vol 73 (4) ◽  
pp. 968-975
Author(s):  
HJ Weiss ◽  
VT Turitto ◽  
HR Baumgartner ◽  
Y Nemerson ◽  
T Hoffmann
Keyword(s):  
Tissue Factor ◽  
Umbilical Artery ◽  
Factor Viia ◽  
Rabbit Aorta ◽  
Coagulation Factors ◽  
Factor Vii ◽  
Factor X ◽  
Factor Activity ◽  
Fibrin Deposition ◽  
Tissue Factor Activity

By a variety of methods, tissue factor activity was demonstrated in the subendothelium of rabbit aorta and human umbilical artery. In one method, everted segments of de-endothelialized vessels were mounted in an annular perfusion chamber and the subendothelial surface was exposed to nonanticoagulated human blood under controlled flow. Procoagulant activity was assessed by measuring fibrin deposition on subendothelium and fibrinopeptide A (FPA) levels in post chamber blood. Both fibrin deposition and FPA were decreased with rabbit vessel segments exposed (at a shear rate of 650 seconds-1) to blood from patients with factor VII deficiency and with umbilical artery segments (at shear rates of 90 to 180 seconds-1) that had been pretreated with a monoclonal antibody to human tissue factor. In a second method, everted umbilical artery segments were mounted on a stir bar and the subendothelial surface was exposed, with stirring, to plasma or purified coagulation factors. The capacity of the surface to clot plasma on addition of calcium was inhibited by the antibody to tissue factor. The surface also activated purified 3H-factor X in the presence of factor VIIa, but not in its absence, and this surface property was almost entirely eliminated by pretreating the vessel segments with antitissue factor. Tissue factor activity in subendothelium could play a role in both the arrest of bleeding and in promoting the formation of thrombi at sites of vascular injury.

scholarly journals Studies of the activation of factor VII bound to tissue factor [see comments]

Blood ◽  
1996 ◽  
Vol 87 (9) ◽  
pp. 3738-3748 ◽  
Author(s):  
LV Rao ◽  
T Williams ◽  
SI Rapaport
Keyword(s):  
Tissue Factor ◽  
Factor Viia ◽  
Tissue Injury ◽  
Factor Xa ◽  
Inhibitory Effect ◽  
Factor Ix ◽  
Factor Vii ◽  
Activate Factor ◽  
Factor X ◽  
Ovarian Carcinoma Cell Line

Experiments were performed to evaluate activation of factor VII bound to relipidated tissue factor (TF) in suspension and to TF constitutively expressed on the surface of an ovarian carcinoma cell line (OC-2008). Activation was assessed by measuring cleavage of 125I- factor VII and by the ability of unlabeled factor VII to catalyze activation of a variant factor IX molecule that, after activation, cannot back-activate factor VII. Factor Xa was found to effectively activate factor VII bound to TF relipidated in either acidic or neutral phospholipid vesicles. Autoactivation of factor VII bound to TF in suspension was dependent on the preparation of TF apoprotein used and the technique of its relipidation. This highlights the need for caution in extrapolating data from TF in suspension to the activation of factor VII bound to cell surfaces during hemostasis. A relatively slow activation of factor VII bound to OC-2008 monolayers in the absence of added protease was observed consistently. Antithrombin in the presence or absence of heparin prevented this basal activation, whereas TF pathway inhibitor (TFPI/factor Xa complexes had only a limited inhibitory effect. Adding a substrate concentration of factor X markedly enhanced basal activation of factor VII, but both TFPI/factor Xa and antithrombin/heparin abolished this enhancement. Overall, our data are compatible with the hypothesis that not all factor VII/TF complexes formed at a site of tissue injury are readily activated to factor VIIa (VIIa)/TF complexes during hemostasis. The clinical significance of this is discussed.

scholarly journals Airway tissue factor-dependent coagulation activity in response to sulfur mustard analog 2-chloroethyl ethyl sulfide

2012 ◽  
Vol 302 (1) ◽  
pp. L82-L92 ◽  
Author(s):  
Raymond C. Rancourt ◽  
Livia A. Veress ◽  
XiaoLing Guo ◽  
Tara N. Jones ◽  
Tara B. Hendry-Hofer ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Tissue Factor ◽  
Sulfur Mustard ◽  
Culture Media ◽  
Active Form ◽  
Coagulation Cascade ◽  
Factor Vii ◽  
Factor X ◽  
Clotting Factors ◽  
Airway Injury

Acute lung injury is a principal cause of morbidity and mortality in response to mustard gas (SM) inhalation. Obstructive, fibrin-containing airway casts have recently been reported in a rat inhalation model employing the SM analog 2-chloroethyl ethyl sulfide (CEES). The present study was designed to identify the mechanism(s) causing activation of the coagulation cascade after CEES-induced airway injury. Here we report that CEES inhalation elevates tissue factor (TF) activity and numbers of detached epithelial cells present in lavage fluid (BALF) from rats after exposure (18 h). In vitro studies using 16HBE cells, or with rat BALF, indicated that detached epithelial cells could convert factor X (FX) to the active form FXa when incubated with factor VII and could elicit rapid clotting of plasma. In addition, immunocytochemical analysis demonstrated elevated cell surface (TF) expression on CEES-exposed 16HBE cells as a function of time. However, total cell TF expression did not increase. Since membrane surfaces bearing TF are important determinants of clot initiation, anticoagulants directed against these entities were tested for ability to limit plasma clotting or FX activation capacity of BALF or culture media. Addition of tifacogin, a TF pathway inhibitor, effectively blocked either activity, demonstrating that the procoagulant actions of CEES were TF pathway dependent. Lactadherin, a protein capable of competing with clotting factors for phospholipid-binding sites, was partially effective in limiting these procoagulant actions. These findings indicate that TF pathway inhibition could be an effective strategy to prevent airway obstruction after SM or CEES inhalation.

Activated Peripheral Mononuclear Cells Plus Soluble Plasma Tissue Factor Activate Factors VII and X in Cardiac Surgical Wounds.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 806-806
Author(s):  
Robert W. Colman ◽  
Mohammad M.H. Khan ◽  
Takashi Hattori ◽  
L. Henry Edmunds4
Keyword(s):  
Cardiac Surgery ◽  
Tissue Factor ◽  
Thrombin Generation ◽  
Mononuclear Cells ◽  
Factor Vii ◽  
Activate Factor ◽  
Factor X ◽  
Complex Wound ◽  
Activated Monocytes

Abstract Objectives: This study examines the role of pericardial wound monocytes in thrombin generation during clinical cardiac surgery with cardiopulmonary bypass (CPB). Background: The mechanism by which wound mononuclear cells rapidly express procoagulant activity is unexplained. Methods: Factor VII activation (FVIIa) was measured using recombinant, truncated, soluble tissue factor (rsTF) and various blood cells in vitro. FVIIa was also measured with monocytes and soluble plasma tissue factor taken before CPB and simultaneously from the pericardial wound and perfusion circuit during CPB in thirteen patients. Results: RsTF in combination with monocytes, but not platelets, neutrophils or red cells, accelerates activation of FVII beginning at 1 pmole/L rsTF. Less than 1% rsTF is bound, yet catalytic activity peaks at 7 minutes and decays afterwards. In wound plasma, monocytes are activated (MCP-1 = 29.5 ± 2.1 pmoles/L) and wound plasma tissue factor (wpTF) is substantially elevated (3.64 ± 0.45 pmoles/L) with 81.7% in the supernatant and 18.3% in microparticles. By Western blot all forms of plasma TF migrate at Mr 65 kDa [TF/FVII(FVIIa) complex]. Wound monocytes and C5a activated prebypass or perfusate monocytes plus wpTF convert all available FVII to FVIIa. Activated monocytes plus supernatant TF/FVII(VIIa) more efficiently activate factor X than microparticle TF/FVII(FVIIa). The correlation coefficient (r) between wound thrombin generation (F1.2) and wpTF is 0.944 (p = 0.0004). Conclusions: During clinical cardiac surgery with CPB wound monocytes plus wpTF or microparticle-free, protein fragments of wound tissue factor preferentially accelerate activation of FVII and FX. This system represents a new mechanism of thrombin generation.

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