scholarly journals Endotoxin Potentiates The Procoagulant Effects Of Tissue Factor

2020 ◽  
Vol 7 (05) ◽  
pp. 4829-4831
Author(s):  
Charles R. Spillert
Keyword(s):  
Tissue Factor ◽  
Blood Coagulation ◽  
Human Blood ◽  
Whole Blood ◽  
Major Trauma ◽  
Morbidity And Mortality ◽  
Blood Coagulation Tests ◽  
Extrinsic Pathway ◽  
Early Generation ◽  
Coagulation Tests

Tissue Factor is the initiator of the extrinsic pathway of blood coagulation.  It is generated in blood as a result of a variety of diseases and conditions and is, in part, responsible for the majority of morbidity and mortality in humans. In spite of this potential release during major trauma or diseases, there are few rapid clinical whole blood coagulation tests that can monitor the early generation of tissue factor. This study will evaluate whether endotoxin enhances the procoagulant effects of tissue factor on human blood and plasma.

scholarly journals Respiratory distress following major trauma: Predictive value of blood coagulation tests

1986 ◽  
Vol 57 (2) ◽  
pp. 158-162 ◽  
Author(s):  
Karl Akke Alberts ◽  
Ingrid Norén ◽  
Margareta Rubin ◽  
Staffan Törngren
Keyword(s):  
Respiratory Distress ◽  
Blood Coagulation ◽  
Predictive Value ◽  
Major Trauma ◽  
Blood Coagulation Tests ◽  
Coagulation Tests

Self-Damping Mechanism in Blood Coagulation

1974 ◽  
Vol 32 (01) ◽  
pp. 057-064 ◽  
Author(s):  
Y Nemerson ◽  
S.A Silverberg ◽  
J Jesty
Keyword(s):  
Tissue Factor ◽  
Blood Coagulation ◽  
Calcium Ions ◽  
Control Mechanism ◽  
Factor Vii ◽  
Damping Factor ◽  
Factor V ◽  
Factor X ◽  
Extrinsic Pathway ◽  
Two Systems

SummaryTwo reactions of the extrinsic pathway of coagulation, the activations of Factor X and prothrombin, have been studied in purified systems and shown to be self-damping. Factor X was activated by the tissue factor - Factor VII complex, and prothrombin by two systems: the coagulant protein of Taipan venom, and the physiological complex of activated Factor X, Factor V, lipid, and calcium ions. In each case the yield of enzyme, activated Factor X or thrombin, is a function of the concentration of activator. These and other observations are considered as a basis for a control mechanism in coagulation.

THE EFFECT OF EARLY BLOOD TRANSFUSION ON THE OUTCOME OF GASTROINTESTINAL HAEMORRHAGE

1987 ◽  
Author(s):  
S D Blair ◽  
S B Javanvrin ◽  
C N McCollum ◽  
R M Greenhalgh
Keyword(s):  
Blood Transfusion ◽  
Blood Coagulation ◽  
Whole Blood ◽  
Randomised Trial ◽  
Gastrointestinal Haemorrhage ◽  
Clotting Time ◽  
Prospective Randomised Trial ◽  
Coagulation Tests ◽  
To Receive ◽  
Upper Gastrointestinal

It has been suggested that mortality due to upper gastrointestinal haemorrhage may be reduced by restricting blood transfusion [1], We have assessed whether this is due to an anticoagulant effect in a prospective randomised trial.One hundred patients with severe, acute gastrointestinal haemorrhage were randomised to receive either at least 2 units of blood during the first 24 hours of admission, or no blood unless their haemaglobin was lessthan 8g/dl or they were shocked. Minor bleeds and varices were excluded As hypercoagulation cannot be measured using conventional coagulation tests, fresh whole blood coagulation was measured by the Biobridge Impedance Clotting Time (ICT). Coagulation was assessed at 24 hour intervals and compared to age matched controls with the results expressed as mean ± sem.The ICT on admission for the transfusion group (n=50) was 3.2±0.2 mins compared to 10±0.2 mins in controls. This hyper-coagulable state was partially reversed to 6.4±0.3 mins at 24 hours (p<0.001). The 50 allocated to receive no blood had a similar ICT on admission of 4.4±0.4 mins but the hypercoagulable state was maintained with ICT at 24 hours of 4.320.4 mins. Only 2 patients not transfused rebled compared to 15 in the early transfusion group (p<0.001). Five patients died, and they were all in the early transfusion group.These findings show there is a hypercoagulable response to haemorrhage which is partially reversed by blood transfusion leading to rebleeding

scholarly journals A sample-to-result system for blood coagulation tests on a microfluidic disk analyzer

2014 ◽  
Vol 8 (5) ◽  
pp. 052105 ◽  
Author(s):  
Chia-Hui Lin ◽  
Cheng-Yuan Liu ◽  
Chih-Hsin Shih ◽  
Chien-Hsing Lu
Keyword(s):  
Blood Coagulation ◽  
Blood Coagulation Tests ◽  
Coagulation Tests

Prognostic significance of blood coagulation tests in carcinoma of the lung and colon

1992 ◽  
Vol 3 (4) ◽  
pp. 429-437
Author(s):  
M. Z. Wojtukiewicz ◽  
L. R. Zacharski ◽  
T. E. Moritz ◽  
K. Hur ◽  
R. L. Edwards ◽  
...  
Keyword(s):  
Blood Coagulation ◽  
Prognostic Significance ◽  
Blood Coagulation Tests ◽  
Coagulation Tests

scholarly journals The contributions of Ca2+, phospholipids and tissue-factor apoprotein to the activation of human blood-coagulation factor X by activated factor VII

1990 ◽  
Vol 265 (2) ◽  
pp. 327-336 ◽  
Author(s):  
V J J Bom ◽  
R M Bertina
Keyword(s):  
Tissue Factor ◽  
Blood Coagulation ◽  
Reaction Rate ◽  
Factor Viia ◽  
Coagulation Factor ◽  
Fluid Phase ◽  
Fold Increase ◽  
Factor Vii ◽  
Factor X ◽  
Extrinsic Pathway

In the extrinsic pathway of blood coagulation, Factor X is activated by a complex of tissue factor, factor VII(a) and Ca2+ ions. Using purified human coagulation factors and a sensitive spectrophotometric assay for Factor Xa, we could demonstrate activation of Factor X by Factor VIIa in the absence of tissue-factor apoprotein, phospholipids and Ca2+. This finding allowed a kinetic analysis of the contribution of each of the cofactors. Ca2+ stimulated the reaction rate 10-fold at an optimum of 6 mM (Vmax. of 1.1 x 10(-3) min-1) mainly by decreasing the Km of Factor X (to 11.4 microM). In the presence of Ca2+, 25 microM-phospholipid caused a 150-fold decrease of the apparent Km and a 2-fold increase of the apparent Vmax. of the reaction; however, both kinetic parameters increased with increasing phospholipid concentration. Tissue-factor apoprotein contributed to the reaction rate mainly by an increase of the Vmax., in both the presence (40,500-fold) and absence (4900-fold) of phospholipid. The formation of a ternary complex of Factor VIIa with tissue-factor apoprotein and phospholipid was responsible for a 15 million-fold increase in the catalytic efficiency of Factor X activation. The presence of Ca2+ was absolutely required for the stimulatory effects of phospholipid and apoprotein. The data fit a general model in which the Ca2(+)-dependent conformation allows Factor VIIa to bind tissue-factor apoprotein and/or a negatively charged phospholipid surface resulting into a decreased intrinsic Km and an increased Vmax. for the activation of fluid-phase Factor X.

Predictive Value of Whole Blood and Plasma Coagulation Tests for Intra- and Postoperative Bleeding Risk: A Systematic Review

2017 ◽  
Vol 43 (07) ◽  
pp. 772-805 ◽  
Author(s):  
Julie Larsen ◽  
Anne-Mette Hvas
Keyword(s):  
Systematic Review ◽  
Blood Coagulation ◽  
Platelet Function ◽  
Whole Blood ◽  
Predictive Value ◽  
Platelet Function Tests ◽  
Predictive Values ◽  
Function Tests ◽  
Perioperative Bleeding ◽  
Coagulation Tests

AbstractExcessive perioperative bleeding is associated with increased morbidity and mortality as well as increased economic costs. A range of whole blood laboratory tests for hemostatic monitoring has emerged, but their ability to predict perioperative bleeding is still debated. We conducted a systematic review of the existing literature assessing the ability of whole blood coagulation (thromboelastography [TEG]/thromboelastometry [ROTEM]/Sonoclot), platelet function tests, and standard plasma-based coagulation tests to predict bleeding in the perioperative setting. We searched PubMed and Embase, covering the period from 1966 to November 2016. In total, 99 original studies were included. The included studies assessed TEG/ROTEM/Sonoclot (n = 29), platelet function tests (n = 27), both test types (n = 8), and standard coagulation tests only (n = 18), and some (n = 17) investigated the predictive value of testing in patients receiving antithrombotic medication. In general, studies reported low positive predictive values for perioperative testing, whereas negative predictive values were high. The studies yielded moderate areas under receiver operator characteristics (ROC) curve (for the majority, 0.60–0.80). In conclusion, while useful in the diagnosis and management of patients with overt bleeding, whole blood coagulation and platelet function tests as well as standard coagulation tests demonstrated limited ability to predict perioperative bleeding in unselected patients. Therefore, we recommend that both whole blood and plasma-based coagulation tests are primarily used in case of bleeding and not for screening in unselected patients prior to surgery.

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