scholarly journals Fibrin formation: effect of calcium ions

Blood ◽  
1978 ◽  
Vol 52 (4) ◽  
pp. 654-658 ◽  
Author(s):  
EP Brass ◽  
WB Forman ◽  
RV Edwards ◽  
O Lindan
Keyword(s):  
Particle Size ◽  
Calcium Ions ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Size Change ◽  
Fibrin Formation ◽  
Fibrin Monomer ◽  
Small Change ◽  
Time Required ◽  
Kinetics Of

Using laser fluctuation spectroscopy, a technique that measures particle size change in solution, the kinetics of fibrin clot formation from fibrinogen can be studied. With this technique the effect of calcium on the three distinguishable phases of clot formation, (1) proteolysis of fibrinogen, (2) fibrinogen-fibrin monomer complex formation, and (3) fibrin monomer polymerization, were investigated. Only a small change in the length of the induction period that results from the fibrinogen-fibrin monomer interactions was observed. However, there was a marked increase in the rate of fibrin monomer polymerization in the presence of calcium ions. These data show that calcium decreases the time required for fibrin formation from fibrinogen by markedly accelerating the phase of fibrin monomer polymerization.

scholarly journals Fibrin formation: effect of calcium ions

Blood ◽  
1978 ◽  
Vol 52 (4) ◽  
pp. 654-658 ◽  
Author(s):  
EP Brass ◽  
WB Forman ◽  
RV Edwards ◽  
O Lindan
Keyword(s):  
Particle Size ◽  
Calcium Ions ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Size Change ◽  
Fibrin Formation ◽  
Fibrin Monomer ◽  
Small Change ◽  
Time Required ◽  
Kinetics Of

Abstract Using laser fluctuation spectroscopy, a technique that measures particle size change in solution, the kinetics of fibrin clot formation from fibrinogen can be studied. With this technique the effect of calcium on the three distinguishable phases of clot formation, (1) proteolysis of fibrinogen, (2) fibrinogen-fibrin monomer complex formation, and (3) fibrin monomer polymerization, were investigated. Only a small change in the length of the induction period that results from the fibrinogen-fibrin monomer interactions was observed. However, there was a marked increase in the rate of fibrin monomer polymerization in the presence of calcium ions. These data show that calcium decreases the time required for fibrin formation from fibrinogen by markedly accelerating the phase of fibrin monomer polymerization.

Fibrin Formation: The Role of the Fibrinogen-Fibrin Monomer Complex

1976 ◽  
Vol 36 (01) ◽  
pp. 037-048 ◽  
Author(s):  
Eric P. Brass ◽  
Walter B. Forman ◽  
Robert V. Edwards ◽  
Olgierd Lindan
Keyword(s):  
Particle Size ◽  
Induction Period ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Appreciable Amount ◽  
Buffer System ◽  
Homeostatic Mechanism ◽  
Fibrin Formation ◽  
Fibrin Monomer

SummaryThe process of fibrin formation using highly purified fibrinogen and thrombin was studied using laser fluctuation spectroscopy, a method that rapidly determines particle size in a solution. Two periods in fibrin clot formation were noted: an induction period during which no fibrin polymerization occurred and a period of rapid increase in particle size. Direct measurement of fibrin monomer polymerization and fibrinopeptide release showed no evidence of an induction period. These observations were best explained by a kinetic model for fibrin clot formation incorporating a reversible fibrinogen-fibrin monomer complex. In this model, the complex serves as a buffer system during the earliest phase of fibrin formation. This prevents the accumulation of free polymerizable fibrin monomer until an appreciable amount of fibrinogen has reacted with thrombin, at which point the fibrin monomer level rises rapidly and polymerization proceeds. Clinically, the complex may be a homeostatic mechanism preventing pathological clotting during periods of elevated fibrinogen.

Studies on Fibrin Formation and Effects of Dextran

1972 ◽  
Vol 28 (02) ◽  
pp. 244-256 ◽  
Author(s):  
T. Z Muzaffar ◽  
G. G Youngson ◽  
W. A. J Bryce ◽  
D. P Dhall
Keyword(s):  
Molecular Weight ◽  
Enzymatic Activity ◽  
Human Platelet ◽  
Clot Formation ◽  
Human Fibrinogen ◽  
Platelet Poor Plasma ◽  
Fibrin Formation ◽  
Fibrin Monomer ◽  
Kinetics Of ◽  
Three Phases

SummaryIn this study highly reproducible turbidimetric techniques are used to investigate clotting of human platelet-poor plasma and purified human fibrinogen solutions by thrombin. Three phases are clearly distinguishable turbidimetrically during clotting. All the three phases are altered by dextran. This effect of dextran is not mediated by any action on the enzymatic activity of thrombin. Further, it is independent of the molecular weight of dextran, but is found related to the final dextran, thrombin and fibrinogen concentrations. Evidence is presented to show that dextran accelerates the polymerisation of fibrin monomer. However, it seems clear that dextran has an additional action quite apart from this effect. These actions of dextran are discussed in relation to kinetics of clot formation.

scholarly journals Fibrin Clot Formation and Lysis in Plasma

2020 ◽  
Vol 3 (4) ◽  
pp. 67
Author(s):  
Julie Brogaard Larsen ◽  
Anne-Mette Hvas
Keyword(s):  
Fibrinolytic Activity ◽  
Research Laboratory ◽  
Ex Vivo ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Coagulation Assays ◽  
Fibrin Formation ◽  
Over Time ◽  
Routine Coagulation

Disturbance in the balance between fibrin formation and fibrinolysis can lead to either bleeding or thrombosis; however, our current routine coagulation assays are not sensitive to altered fibrinolysis. The clot formation and lysis assay is a dynamic plasma-based analysis that assesses the patient’s capacity for fibrin formation and fibrinolysis by adding an activator of coagulation as well as fibrinolysis to plasma and measuring ex vivo fibrin clot formation and breakdown over time. This assay provides detailed information on the fibrinolytic activity but is currently used for research only, as the assay is prone to inter-laboratory variation and as it demands experienced laboratory technicians as well as specialized personnel to validate and interpret the results. Here, we describe a protocol for the clot formation and lysis assay used at our research laboratory.

scholarly journals STAPHYLOCOCCAL CLUMPING WITH SOLUBLE FIBRIN MONOMER COMPLEXES

1967 ◽  
Vol 126 (5) ◽  
pp. 979-988 ◽  
Author(s):  
B. Lipiński ◽  
J. Hawiger ◽  
J. Jeljaszewicz
Keyword(s):  
Blood Clotting ◽  
Sodium Citrate ◽  
Fibrin Clot ◽  
Protamine Sulfate ◽  
Clot Lysis ◽  
Soluble Fibrin ◽  
Staph Aureus ◽  
Fibrin Monomer ◽  
Kinetics Of

Clumping reaction, using standard suspension of Staph. aureus Newman D-2-C strain and various substrates, was quantitatively tested. It has been shown that clumping occurs in fibrin lysate containing soluble fibrin monomer complexes unclottable by thrombin. The reaction was positive with staphylococcal strains possessing clumping factor regardless of staphylocoagulase production. Clumping reaction is similar to paracoagulation reaction induced by protamine sulfate. The substrate for both reactions is stable at 56°C but is destroyed at 60°C. The kinetics of substrate formation for both reactions during fibrin clot lysis is also similar. Clumping reaction with a strain of Staph. epidermidis possessing no clumping factor was positive when these bacteria were coated with protamine sulfate. The effect of heparin, sodium citrate, urea, 2-mercaptoethanol, merthiolate, and mucin on both reactions was tested. The present findings explain the clumping reaction in serum and emphasize the role of blood clotting and fibrinolytic systems in this phenomenon.

scholarly journals Slounase, a Batroxobin Containing Activated Factor X Effectively Enhances Hemostatic Clot Formation and Reducing Bleeding in Hypocoagulant Conditions in Mice

2021 ◽  
Vol 27 ◽  
pp. 107602962110185
Author(s):  
Reheman Adili ◽  
Madeline Jackson ◽  
Livia Stanger ◽  
Xiangrong Dai ◽  
Mandy Li ◽  
...  
Keyword(s):  
Bleeding Time ◽  
Fibrin Clot ◽  
Biochemical Properties ◽  
Clot Formation ◽  
Factor X ◽  
Wild Type ◽  
Fibrin Formation ◽  
Uncontrolled Bleeding

Uncontrolled bleeding associated with trauma and surgery is the leading cause of preventable death. Batroxobin, a snake venom-derived thrombin-like serine protease, has been shown to clot fibrinogen by cleaving fibrinopeptide A in a manner distinctly different from thrombin, even in the presence of heparin. The biochemical properties of batroxobin and its effect on coagulation have been well characterized in vitro. However, the efficacy of batroxobin on hemostatic clot formation in vivo is not well studied due to the lack of reliable in vivo hemostasis models. Here, we studied the efficacy of batroxobin and slounase, a batroxobin containing activated factor X, on hemostatic clot composition and bleeding using intravital microcopy laser ablation hemostasis models in micro and macro vessels and liver puncture hemostasis models in normal and heparin-induced hypocoagulant mice. We found that prophylactic treatment in wild-type mice with batroxobin, slounase and activated factor X significantly enhanced platelet-rich fibrin clot formation following vascular injury. In heparin-treated mice, batroxobin treatment resulted in detectable fibrin formation and a modest increase in hemostatic clot size, while activated factor X had no effect. In contrast, slounase treatment significantly enhanced both platelet recruitment and fibrin formation, forming a stable clot and shortening bleeding time and blood loss in wild-type and heparin-treated hypocoagulant mice. Our data demonstrate that, while batroxobin enhances fibrin formation, slounase was able to enhance hemostasis in normal mice and restore hemostasis in hypocoagulant conditions via the enhancement of fibrin formation and platelet activation, indicating that slounase is more effective in controlling hemorrhage.

Fibrin presence within aortic valves in patients with aortic stenosis: Association with in vivo thrombin generation and fibrin clot properties

2011 ◽  
Vol 105 (02) ◽  
pp. 254-260 ◽  
Author(s):  
Joanna Natorska ◽  
Grzegorz Marek ◽  
Marta Hlawaty ◽  
Jerzy Sadowski ◽  
Wieslawa Tracz ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Stenosis ◽  
Aortic Insufficiency ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Lysis Time ◽  
Transvalvular Gradient ◽  
Time Required ◽  
D Dimer

SummaryA role of coagulation in the pathogenesis of aortic stenosis (AS) is unknown. The aim of this study was to investigate the fibrin (Fn) presence and its determinants in calcified stenotic aortic valve leaflets. Twenty-one patients with dominant AS and 17 well-matched patients with dominant aortic insufficiency (AI) undergoing aortic valve replacement were studied. Immunofluorescence analysis was performed on decalcified leaflets using antibodies against human Fn and tissue factor (TF). Fn-positive (41.4%) and TF-positive (25.3%) areas were increased in AS valves compared with AI valves (7.9% and 5.9%, respectively, both p<0.001). Patients with AS had elevated plasma D-dimer (236.4 ± 28 ng/ml, p=0.002) and prothrombin fragment 1+2 (F1.2) (261.7 ± 27.1 pM, p=0.005) compared to AI subjects (142.8 ± 10 ng/ml and 131.2 ± 1.3 pM, respectively). In AS patients Fn-positive areas correlated with TF-positive areas (r=0.68, p=0.0005), D-dimer (r=0.45, p=0.018), F1.2 (r=0.64, p=0.002), the time required for plasma fibrin clot formation (r=0.44, p=0.015) and maximum absorbance of fibrin clots (r=-0.38, p<0.0001), but not with clot permeability or lysis time. Thickness of Fn layer within AS valves was associated with maximum transvalvular gradient (r =0.41, p=0.048). Patients with maximal gradient above 75 mmHg (n=11) showed significant associations between Fn-positive area and both maximal (r =0.63) and mean (r =0.67) transvalvular gradients. Large fibrin amounts, mostly co-localised with TF, are present within the valve leaflets of patients with advanced AS. In vivothrombin generation and fibrin clot formation are associated with the extent of Fn presence within leaflets, which might contribute to the AS progression.

Properties of Fibrinogen Cleaved by Jararhagin, a Metalloproteinase from the Venom of Bothrops jararaca

1994 ◽  
Vol 72 (02) ◽  
pp. 244-249 ◽  
Author(s):  
Aura S Kamiguti ◽  
Joseph R Slupsky ◽  
Mirko Zuzel ◽  
Charles R M Hay
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Human Fibrinogen ◽  
Activated Platelets ◽  
Bothrops Jararaca ◽  
Platelet Binding ◽  
Fibrin Monomers ◽  
Fibrinogen Molecule

SummaryHaemorrhagic metalloproteinases from Bothrops jararaca and other venoms degrade vessel-wall and plasma proteins involved in platelet plug and fibrin clot formation. These enzymes also cause proteolytic digestion of fibrinogen which has been suggested to cause defective platelet function. Fibrinogen degradation by jararhagin, a metalloproteinase from B. jararaca, and the effect of jararhagin fibrinogenolysis on both platelet aggregation and fibrin clot formation were investigated. Jararhagin was found to cleave human fibrinogen in the C-terminal region of the Aα-chain giving rise to a 285-290 kDa fibrinogen molecule lacking the Aα-chain RGD 572-574 platelet-binding site. Platelet binding and aggregation of ADP-activated platelets is unaffected by this modification. This indicates that the lost site is not essential for platelet aggregation, and that the remaining platelet binding sites located in the N-terminal portion of Aα chains (RGD 95-97) and the C-terminal of γ chains (dodecapeptide 400-411) are unaffected by jararhagin-digestion of fibrinogen. Fibrin clot formation with thrombin of this remnant fibrinogen molecule was defective, with poor polymerization of fibrin monomers but normal release of FPA. The abnormal polymerization could be explained by the loss of one of the two complementary polymerization sites required for side-by-side association of fibrin protofibrils. Jararhagin-induced inhibition of platelet function, an important cause of haemorrhage in envenomed patients, is not caused by proteolysis of fibrinogen, as had been thought, and the mechanism remains to be elucidated.

Prothrombin Evaluation as Obtained by Kinetics Studies of Antigen-Antibody Reaction in a Laser Nephelometer

1984 ◽  
Vol 52 (01) ◽  
pp. 015-018 ◽  
Author(s):  
A Girolami ◽  
A Sticchi ◽  
R Melizzi ◽  
L Saggin ◽  
G Ruzza
Keyword(s):  
Liver Cirrhosis ◽  
Cirrhotic Patient ◽  
Maximum Rate ◽  
Serum Proteins ◽  
Clotting Factors ◽  
Kinetics Studies ◽  
Maximum Value ◽  
Time Required ◽  
Antigen Antibody ◽  
Kinetics Of

SummaryLaser nephelometry is a technique which allows the evaluation of the concentration of several serum proteins and clotting factors. By means of this technique it is also possible to study the kinetics of the reaction between antigen and antibody. We studied the kinetics of the reaction between prothrombin and an antiprothrombin antiserum using several prothrombins namely: Prothrombin Padua, prothrombin Molise, which are two congenital dysprothrombinemias, cirrhotic, coumarin or normal prothrombins. Different behaviors in the kinetics of the reactions were shown even when the concentration of prothrombins was about the same in all plasma tested. These differences were analyzed by means of a computer (Apple II 48 RAM) programmed to solve four unknown equations (Rodbard’s equation). From the data so obtained one can see that when voltages at the beginning and at the end of the reaction are in all cases about the same, a clear difference in the time required to reach half the maximum value of the voltage can still be demonstrated. This parameter, which is expressed in minutes, is longer in coumarin and prothrombin Molise than in controls. On the contrary it is shorter in prothrombin Padua and has about the same value of controls in the cirrhotic patient. Moreover the time at which the maximum rate is obtained is longer in coumarin and prothrombin Molise than in controls and shorter in liver cirrhosis and prothrombin Padua. In conclusion data obtained show that coumarin prothrombin behaves in a different way from cirrhotic prothrombin and also that there is a different behaviour between the two congenital dysprothrombinemias.

The Anticoagulant Effect of Heparinoid Org 10172 During Haemodialysis: An Objective Assessment

1986 ◽  
Vol 55 (02) ◽  
pp. 271-275 ◽  
Author(s):  
Helen Ireland ◽  
D A Lane ◽  
Angela Flynn ◽  
E Anastassiades ◽  
J R Curtis
Keyword(s):  
Renal Failure ◽  
Bolus Dose ◽  
Bolus Injection ◽  
Objective Assessment ◽  
Factor Xa ◽  
Fibrin Clot ◽  
Natural Origin ◽  
Fibrin Formation ◽  
Single Bolus Injection

SummaryThe heparinoid of natural origin Org 10172 has anti-factor Xa activity but minimal anti-thrombin activity, and little effect upon broad spectrum assays such as the KCCT in vitro. Its anticoagulant effects have been compared to those of commercial heparin in 7 patients undergoing haemodialysis for chronic renal failure. Commercial heparin was administered in a dose (5,000 iu bolus + 1,500 iu/hour continuous iv infusion) previously shown to inhibit fibrin formation during haemodialysis. This produced mean anti-factor Xa levels in plasma between 0.7-1.0 iu/ml and largely suppressed fibrin formation for 5 h dialysis measured as mean FPA levels in plasma. Administration of Org 10172 as a bolus of 1,350 anti-factor Xa u or 2,000-2,400 anti-factor Xa u produced plasma anti-factor Xa levels of less than 0.5 u/ml and allowed fibrin clot and FPA generation during dialysis. Org 10172 administered as a bolus dose of 4,000-4,800 anti-factor Xa u produced mean anti-factor Xa levels of greater than 0.5 u/ml, allowed dialysis of 6 patients for 5 h and appreciably suppressed FPA generation during dialysis, with little effect on the KCCT.It is concluded that the anti-factor Xa activity of Org 10172 may reflect its ability to inhibit fibrin during dialysis and that single bolus injection of Org 10172 may be a useful alternative method of achieving anticoagulation.

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