Effects of Thorium Dioxide upon Blood Clotting and Platelets. I. In Vitro Studies

1966 ◽  
Vol 16 (03/04) ◽  
pp. 333-353 ◽  
Author(s):  
P. F Hjort ◽  
W. G McGehee ◽  
S. I Rapaport
Keyword(s):  
Blood Clotting ◽  
In Vitro Studies ◽  
Factor V ◽  
Clotting Factors ◽  
Thorium Dioxide ◽  
Platelet Functions

SummaryThorium dioxide was found to damage clotting factors and to interfere with platelet functions in vitro: 1. Fibrinogen and factor V were progressively inactivated. Citrate did not prevent damage to these factors. Thorium dioxide was concentrated in the clot, which suggests that it binds to fibrinogen.2. Factors II, VII, IX, and X were also inactivated. Inactivation of these factors could be prevented or reversed by citrate.3. Factors VIII, XI, and XII were not altered.4. Platelets became less adhesive and less subject to aggregation.These effects were more marked with unfiltered suspensions of thorium dioxide (TDS) than with filtered suspensions (Thorotrast). They were also increased by increasing the concentration of thorium dioxide, and the time and temperature of incubation. Thorium dioxide probably forms complexes with the clotting proteins, thereby making them less reactive.

scholarly journals The Blood Clotting Properties of Rabbit Peritoneal Leukocytes in Vitro

1967 ◽  
Vol 17 (01/02) ◽  
pp. 222-236 ◽  
Author(s):  
S. I Rapaport ◽  
P. F Hjort
Keyword(s):  
Blood Clotting ◽  
Anticoagulant Activity ◽  
In Vitro Study ◽  
Factor V ◽  
Clotting Factors ◽  
Clotting System ◽  
Procoagulant Effect ◽  
Peritoneal Leukocytes ◽  
Thromboplastic Activity

SummaryA systematic in vitro study has been carried out of the blood clotting properties of rabbit peritoneal leukocytes. Rabbit heterophils have been shown to possess weak but definite tissue thromboplastic activity. They also contain an anticoagulant activity which is active in the intrinsic clotting system, in the extrinsic clotting system with brain thromboplastin, and in clotting systems with Russell’s viper venom. When the thromboplastic activity of the white cell itself initiates clotting, the anticoagulant is much less effective and the procoagulant effect of the WBC suspension predominates. Rabbit heterophils do not bind plasma clotting factors, do not activative factor V, and, under our conditions, do not precipitate fibrinogen from normal plasma, from plasma exposed to traces of thrombin in vitro, or from plasma of rabbits given endotoxin.The relation of these findings to the role of the granulocyte in the pathogenesis of the generalized Shwartzman reaction has been discussed.

The Control Of Antithrombotic Prophylaxis And Therapy: A Pro-Coagulant Effect Of Heparin

1981 ◽  
Author(s):  
E Szwarcer ◽  
R Giuliani ◽  
E Martinez Aquino
Keyword(s):  
Blood Coagulation ◽  
Antithrombin Iii ◽  
Fixed Time ◽  
In Vitro Studies ◽  
In Vivo Studies ◽  
Clotting Factors ◽  
Platelet Poor Plasma ◽  
Normal Platelet

For studying heparin effect on blood coagulation and on inhibitors, the drug was added at increasing amounts to a normal platelet poor plasma (PPP), and to plasmas of patients with variable amounts of clotting factors (cirrhotic, pregnant, etc) -IN VITRO STUDIES-, and infused to the same individuals -IN VIVO STUDIES-. Modifications on two clotting assays (KCCT-TT) were compared to heparin potentiating effect on AntiXa (Denson & Bonnar tech).When studied IN VITRO, the sensibility of KCCT, TT, and AntiXa techniques for heparin measurement was similar. IN VIVO, an apparently greater sensibility using AntiXa technique was observed.For determining if this phenomena was related to a specific enhanced potentiating effect of the inhibitor against Xa, exerted by heparin IN VIVO, experiences were repeated IN VITRO and IN VIVO, measuring heparin effect on KCCT, TT, and on the inhibitor, studied against Xa and thrombin. A personal technique was used for the measurement of Antithrombin III heparin potentiating effect, using diluted platelet poor test plasma, heated (56°C 15’) and incubated with thrombin during a fixed time, and reading residual thrombin on citrated human PPP. IN VITRO, all techniques were similar in their ability to show heparin presence.IN VIVO, the potentiating effect of heparin on the inhibitor, measured against Xa or thrombin, was greater than the changes obtained on KCCT or TT.So, AntiXa-Antithrombin III techniques seem to be more sensitive for heparin measurement IN VIVO.This “dissociation” of results in between the potentiating effect on the inhibitor, that is not simultaneously exerted on global coagulation, is interpreted as a heparin pro-coagulant effect, exerted by the drug IN VIVO.

In vitro effects of human neutrophil cathepsin G on thrombin generation: Both acceleration and decreased potential

2010 ◽  
Vol 104 (09) ◽  
pp. 514-522 ◽  
Author(s):  
Thomas Lecompte ◽  
Agnès Tournier ◽  
Lise Morlon ◽  
Monique Marchand-Arvier ◽  
Claude Vigneron ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Thrombin Generation ◽  
Time Course ◽  
Anticoagulant Activity ◽  
Cathepsin G ◽  
Coagulation Cascade ◽  
Clotting Factor ◽  
Factor V ◽  
Clotting Factors

SummaryCathepsin G (Cath G), a serine-protease found in neutrophils, has been reported to have effects that could either facilitate or impede coagulation. Thrombin generation (CAT method) was chosen to study its overall effect on the process, at a plasma concentration (240 nM) observed after neutrophil activation. Coagulation was triggered by tissue factor in the presence of platelets or phospholipid vesicles. To help identify potential targets of Cath G, plasma depleted of clotting factors or of inhibitors was used. Cath G induced a puzzling combination of two diverging effects of varying intensities depending on the phospholipid surface provided: accelerating the process under the three conditions (shortened clotting time by up to 30%), and impeding the process during the same thrombin generation time-course since thrombin peak and ETP (total thrombin potential) were decreased, up to 45% and 12%, respectively, suggestive of deficient prothrombinase. This is consistent with Cath G working on at least two targets in the coagulation cascade. Our data indicate that coagulation acceleration can be attributed neither to platelet activation and nor to activation of a clotting factor. When TFPI (tissue factor pathway inhibitor) was absent, no effect on lag time was observed and the anticoagulant activity of TFPI was decreased in the presence of Cath G. Consistent with the literature and the hypothesis of deficient prothrombinase, experiments using Russel’s Viper Venom indicate that the anticoagulant effect can be attributed to a deleterious effect on factor V. The clinical relevance of these findings deserves to be studied.

Lonomia obliqua Caterpillar Spicules Trigger Human Blood Coagulation via Activation of Factor X and Prothrombin

1998 ◽  
Vol 79 (03) ◽  
pp. 539-542 ◽  
Author(s):  
José Donato ◽  
Ronilson Moreno ◽  
Stephen Hyslop ◽  
Alaor Duarte ◽  
Edson Antunes ◽  
...  
Keyword(s):  
Blood Clotting ◽  
Clot Formation ◽  
Clotting Factor ◽  
Detectable Effect ◽  
Factor X ◽  
Clotting Factors ◽  
Clotting Cascade ◽  
Serine Protease Family ◽  
Lonomia Obliqua

SummaryIn southern Brazil, envenomation by larvae of the moth Lonomia obliqua (Walker) may result in blood clotting factor depletion, leading to disseminated intravascular coagulation with subsequent haemorrhage and acute renal failure which may prove fatal. We have examined the effect of a crude extract of spicules from these caterpillars on in vitro hemostasis. The extract alone did not aggregate platelets and had no detectable effect on purified fibrinogen, suggesting that extract induces clot formation by triggering activation of the clotting cascade. In agreement with the presence of thrombin-mediated activity, hirudin prevented clot formation. The extract was found to activate both prothrombin and factor X, suggesting that the depletion of blood clotting factors results from the steady activation of factor X and prothrombin. Heating and diisopropylfluorophosphate abolished the procoagulant activity of the extract, indicating that the active component involved is a protein that may belong to the serine protease family of enzymes. The ability of hirudin to inhibit this coagulant activity suggests that this inhibitor could be beneficial in the treatment of patients envenomed by L. obliqua caterpillars.

The Effect of Halotan and Ether Anaesthesia on Some Parameters of Blood Clotting and Fibrinolysis.

1979 ◽  
Author(s):  
K. Korfel ◽  
M. Bielawiec ◽  
M. Myśliwiec
Keyword(s):  
Platelet Aggregation ◽  
Fibrinolytic Activity ◽  
Blood Clotting ◽  
Factor V ◽  
Platelet Adhesiveness ◽  
Ether Anaesthesia ◽  
Refractory State

The effect of anaesthesia with halotan and ether /100 and 80 casea respectively/ on some parameters of blood clottine and fibrinolysis was investigated. The influence of the drugs on blood clotting and fibrinolysis in vitro was also investigated. Halotan anaesthesia caused decrease In fibrinogen, prothrombin, factor V and number of platelets. Platelet adhesiveness was increased. Ether anaesthesia increased fibrinolytic activity and platelet stickiness. Halotan in vitro shortened r + k and prolonged ma in TEG. The both drugs induced reversible platelet aggregation with subsequent “refractory state” of platelets to ADP. Ether in vitro increased fibrinolytic activity. The results show that the Influence of anaesthetic drugs on blood clotting and fibrinolysis should be taken into account in the choice of the proper anaesthetic in patienta with impaired haenostasis.

scholarly journals Combined factor V-VIII deficiency: a case report with studies of factor V and VIII activation by thrombin

Blood ◽  
1981 ◽  
Vol 58 (5) ◽  
pp. 983-985 ◽  
Author(s):  
MB Hultin ◽  
ME Eyster
Keyword(s):  
Case Report ◽  
Factor Viii ◽  
In Vitro Studies ◽  
Factor V ◽  
Coagulant Activity

A new case of combined factor V-VIII deficiency is reported with in vitro studies of factors V and VIII activation by thrombin. The normal activation of factors V and VIII demonstrated in the patient's plasma and the equivalent levels of factor VIII coagulant activity and coagulant antigen support the hypothesis that a quantitative rather than qualitative defect in factors V and VIII is present in this disorder.

Blood Compatibility of Stainless-Steel and Titanium Immobilized with Alginic Acid Layers

2002 ◽  
Vol 734 ◽  
Author(s):  
Tomohiko Yoshioka ◽  
Kanji Tsuru ◽  
Satoshi Hayakawa ◽  
Akiyoshi Osaka
Keyword(s):  
Stainless Steel ◽  
Photoelectron Spectroscopy ◽  
Blood Clotting ◽  
Alginic Acid ◽  
Blood Compatibility ◽  
Adhesion Assay ◽  
Clotting Factors ◽  
Titanium Substrates ◽  
Blood Clotting Factors

ABSTRACTγ-Aminopropyltriethoxysilane (γ-APS) was grafted on stainless-steel and titanium substrates, and subsequently alginic acid layer was immobilized on them. Their surfaces were characterized with X-ray photoelectron spectroscopy (XPS) and contact angle measurement. Blood compatibility of thus obtained substrates was evaluated in terms of both the number of the adhered platelets and blood clotting factors for plasma contacted with the substrates such as active partial thromboplastin time (PTT), prothrombin time (PT), and amount of fibrinogen (Fib). The steel and titanium substrates with alginic acid layer did not affect blood clotting factors. In vitro platelet adhesion assay indicated that those substrates adhered less number of platelets than non-treated substrates. Hence the alginic acid immobilization leads to blood compatible surfaces.

scholarly journals Combined factor V-VIII deficiency: a case report with studies of factor V and VIII activation by thrombin

Blood ◽  
1981 ◽  
Vol 58 (5) ◽  
pp. 983-985 ◽  
Author(s):  
MB Hultin ◽  
ME Eyster
Keyword(s):  
Case Report ◽  
Factor Viii ◽  
In Vitro Studies ◽  
Factor V ◽  
Coagulant Activity

Abstract A new case of combined factor V-VIII deficiency is reported with in vitro studies of factors V and VIII activation by thrombin. The normal activation of factors V and VIII demonstrated in the patient's plasma and the equivalent levels of factor VIII coagulant activity and coagulant antigen support the hypothesis that a quantitative rather than qualitative defect in factors V and VIII is present in this disorder.

Protein C Is Responsible for the Rapid Inactivation of Factor Va following Blood Clotting In Vitro

1994 ◽  
Vol 72 (01) ◽  
pp. 070-073
Author(s):  
Denise E Jackson ◽  
Christina A Mitchell ◽  
Hatem H Salem
Keyword(s):  
Protein C ◽  
Blood Clotting ◽  
Essential Role ◽  
The Other ◽  
Factor V ◽  
Factor Va ◽  
Rapid Inactivation ◽  
Protein C Activity

SummaryWhen whole blood is allowed to clot in vitro, factor V is rapidly activated to factor Va which is subsequently inactivated. We developed two monoclonal anti-protein C antibodies, one of which inhibits protein C activation and the other inhibits protein C activity. The addition of either antibody to blood before clotting in vitro significantly inhibited the inactivation of factor Va, confirming the essential role of protein C in mediating the rapid inactivation of factor Va.

Reversible Inhibition of the In Vitro Coagulation of Human Plasma by Lectins

1982 ◽  
Vol 48 (02) ◽  
pp. 120-124 ◽  
Author(s):  
J-M Freyssinet ◽  
D Thevenon ◽  
A Souque ◽  
M Suscillon
Keyword(s):  
Blood Clotting ◽  
Inhibitory Effect ◽  
Phospholipid Vesicles ◽  
Carbohydrate Binding ◽  
Clotting Factors ◽  
Con A ◽  
Acetylneuraminic Acid ◽  
Human Control ◽  
Blood Clotting Factors

SummaryWheat germ agglutinin (WGA) and concanavalin A (Con-A) (also red kidney bean agglutinin, PHA) have been found to be inhibitors of plasma clotting in vitro. At 40 µg/ml and 250 µg/ml (4.4 µM and 10 µM in carbohydrate binding sites, final concentrations) respectively, WGA and Con-A are able to double the activated partial thromboplastin time of normal human control plasma. Their inhibitory effect is due to their capacity to interact with the carbohydrate portion of blood clotting factors. It is totally abolished in the presence of specific saccharides for WGA or Con-A and is attenuated in the presence of 4% (v/v, final concentration) of human erythrocytes. The action of WGA is mediated by its ability to interact with N-acetylneuraminic acid. When purified phospholipid vesicles plus kaolin are used as an activator instead of cephalidin, this effect persists to the same extent. These two lectins also prolong the plasma clotting time using Russell's viper venom plus purified phospholipid vesicles as an activator. Quick's time was also prolonged by WGA and Con-A but to a lesser extent in this case. WGA can interact directly with some purified blood clotting factors (IX, X and II) in a classical lectin-glycoprotein precipitin reaction. When assessed at individual factors level in whole plasma using clotting assays, direct inhibitions by WGA are only apparent.

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