A Comparison of the Anticoagulant Actions of Commercially Available Contrast Media (CM)

Previous studies have reported on the anticoagulant effect of commercially available contrast media used in diagnostic radiology. The purpose of this study is to compare the anticoagulant actions of these agents in vitro. Eight commercially available contrast medias were supplemented to citrated human plasma (CNP) in 1:10, 1:20 and 1:50 proportions; isomolar sucrose, glucose, sodium chloride, and saline supplemented CNP were used as controls. Prothrombin time (FT) , partial thromboplastin time (PTT), thrombin time (TT), antithrombin-III, plasminogenplasnun and factor assays were performed at 0 time, 30 minutes and 2 hours after incubation at 37°C. No significant alteration of the coagulation parameters were observed at 1:50 dilution, however at 1:10 and 1:20 dilution, most contrast media produced aberration of clotting parameters. The antithrombin potency of these contrast media at a 1:10 dilution ranged from 0.3-1.3 u/ml heparin. In addition, this antithrombin activity was synergistic with heparin. The antithrombin activity of these agents was not neutralized by protamine sulfate, polybrene or toluidine blue in the amounts which neutralized 1 u/ml heparin. Analysis of various clotting factors revealed that factors II, V, VII and XII were not affected by contrast media. Factors VIII and IX were depressed significantly. These changes were mainly dependent on the concentration of meglumine in the contrast media. Similar studies on the blood obtained from patients infused with contrast media for diagnostic purposes are in progress in our laboratory.

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THE EFFECT OF THE VENOM OF THE ORIENTAL HORNET ON COAGULATION FACTORS

10.1055/s-0038-1644338 ◽

1987 ◽

Author(s):

A Kornberg ◽

S Kaufman ◽

L Silber ◽

J Ishay

Keyword(s):

Human Plasma ◽

Degradation Products ◽

Anticoagulant Activity ◽

Coagulation Factors ◽

Plasma Fibrinogen ◽

Thrombin Time ◽

Clotting Factors ◽

Viii And Ix

The extract from the venom sac of Vespa orientalis (VSE) inactivates exogenous and endogenous thromboplastin (Joshua and Ishay, Toxicon, 13:11-20,1975). The prolongation of both prothrombin time (PT) and recalcification time suggests inactivation of other factors. The aim of the present study is to investigate the effect of VSE on clotting factors. A lyophilized VSE with protein concentration of 5 mg/ml was used. Studies were performed in vitro with human plasma and in vivo in cats. Routine methods were employed for the assay of PT, activated tissue thromboplastin (APTT), thrombin time (TT), fibrinogen degradation products (FDP), fibrinogen and factors V,VII,VIII,IX,X. Human plasma was incubated with various concentrations of VSE (0,1,5,10,50,100 μg/ml) for 60 min and for various incubation times (0,5,15,30,+ 60,90,120 min) with 50 μg/ml VSE (n=8). 1 μg/ml VSE prolonged PT from 13.5 to 16 sec (p<0.05) and APTT from 62 to 180 sec. PT was maximal (17.7 sec) with 10 μg/ml and APTT (442 sec) with 50 μg/ml VSE. Factors V,VII,X decreased gradually from 94-105% to 11%,11% and 29% with 100 μg/ml VSE and VIII and IX to 1% even with 1 μg/ml VSE. After 5 min with constant concentration of VSE (50 μg/ml) PT was 14.9 sec (normal 13 sec) and APTT 165 sec (normal 54 sec). Both were maximal (17.5 and 298 sec) after 60 min. Factors VII and X decreased to 13% and 32% and VIII and IX to >1% after 60 min of incubation. Injection of 5 mg/kg VSE to cats (n=6-8) resulted in prolongation of PT from 9.4 to 11.2 sec and of APTT from 19.5 to 63 sec after 5 min. Both were maximal after 90 min (12.3 and 127 sec). Factors V,VII and X decreased from 100% to 7.6%, 13% and 37% and VIII and IX to 1% after 10 min. In all experiments TT and plasma fibrinogen were not affected and FDP were normal. Heating of VSE for 5 min at 80°C abolished completely the anticoagulant activity but dialysis for 24 hr at 4°C had no effect on it. The activity was eluted on Sephadex-25 both in void and post void volumes. The results show that VSE has a potent anticoagulant activity against various factors. Factors VIII and IX are markedly decreased. The effect on V, VII and X is moderate. Plasma fibrinogen is not affected. The nature and clinical significance of the anticoagulant activity merit further investigation.

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Effect of Angiography on Blood Coagulation

10.1055/s-0039-1680511 ◽

1977 ◽

Author(s):

W. H. Krause ◽

A. Lang

Keyword(s):

Contrast Media ◽

Prothrombin Time ◽

Antithrombin Iii ◽

Degradation Products ◽

Anticoagulant Activity ◽

Thromboembolic Complication ◽

Thrombin Time ◽

Media Concentration

It is known, that angiographic contrast media have an anticoagulant activity in vitro. The purpose of the present study was, to investigate this effect in vivo. The catheter was introduced percutaneously according to Seldinger into the femoral artery. The prothrombin time, activated thromboplastin time (APTT), thrombin time, reptilase time, fibrinogen, plasminogen, antithrombin III, platelets, fibrin/fibrinogen degradation products (FDP), haematocrit and contrast media concentration were studied in a series of 50 patients before and following abdominal aorto-arteriographic procedures up to 6 hours. Thrombin time and reptilase time were prolonged significantly 30 and 60 minutes after angiography. There was a correlation between clotting tiies and contrast media concentrations. Prothrombin time, APTT, and platelet counts remained unchanged. Fibrinogen, plasminogen,and antithrombin III levels showed a significant reduction after 30 minutes. FDP concentrations were increased significantly up to 6 hours, there was no correlation between contrast media concentrations and split products. The results were corrected for contrast media dilution according to the haematocrit. No thromboembolic complication was observed. The results suggest that angiographic procedure may initiate an intravascular coagulation with an activation of the fibrinolytic system. In addition the contrast media showed an inhibition of fibrin polymerization in vivo.

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Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657178 ◽

1982 ◽

Vol 47 (03) ◽

pp. 244-248 ◽

Cited By ~ 47

Author(s):

D P Thomas ◽

Rosemary E Merton ◽

T W Barrowcliffe ◽

L Thunberg ◽

U Lindahl

Keyword(s):

Antithrombin Iii ◽

Specific Activity ◽

High Specific Activity ◽

Factor Xa ◽

Blood Levels ◽

Thrombin Time ◽

High Affinity ◽

Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

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Responsiveness of the activated partial thromboplastin time and dilute thrombin time to argatroban: Results of an in vitro study

International Journal of Laboratory Hematology ◽

10.1111/ijlh.13165 ◽

2020 ◽

Vol 42 (3) ◽

Author(s):

Erica Scalambrino ◽

Lidia Padovan ◽

Veena Chantarangkul ◽

Marigrazia Clerici ◽

Andrea Artoni ◽

...

Keyword(s):

Partial Thromboplastin Time ◽

In Vitro Study ◽

Activated Partial Thromboplastin Time ◽

Vitro Study ◽

Thrombin Time

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

10.1055/s-0038-1653150 ◽

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.

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The Heparin Inhibiting Property of Brain Thromboplastin

10.1055/s-0039-1682625 ◽

1977 ◽

Author(s):

E.D. Gomperts ◽

M. Zucker

Keyword(s):

Prothrombin Time ◽

Antithrombin Iii ◽

Proteinase Inhibitors ◽

Serine Proteinase ◽

Weight Fraction ◽

High Molecular Weight Fraction ◽

Thrombin Time ◽

Factor X ◽

Heparin Resistance

Antithrombin III is one of the serine proteinase inhibitors of the plasma which has been shown to specifically inhibit thrombin as well as Factor X. Heparin acts via antithrombin III, the heparin cofactor, hence it is difficult to explain the relative insensitivity of the prothrombin time to the presence of heparin in plasma as both thrombin, ana Factox Xa are associated functionally with the prothrombin time. This insensitivity becomes more obvious on appreciating the extreme sensitivity to heparin of the activated partial thromboplastin time as well as the thrombin time. This communication reports the demonstration of heparin inhibiting action of brain thromboplastin. The response of the prothrombin time to heparin under various conditions, and the effect of brain thromboplastin obtained from various sources and by different preparative techniques on the action of heparin in vitvo have been studied. The heparin inhibiting activity was shown to parallel the tissue factor activity. It is heat labile, non-dialysable, destroyed by detergent activity and lies in a high molecular weight fraction of the brain thromboplastin preparation (>300,000). In addition to explaining certain in vitro phenomena, these observations may explain the previously observed heparin resistance in the generalised Schwartzman phenomenon.

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Inhibition of Thrombotic Side Effects of II, VII, IX and X Concentrates

10.1055/s-0039-1689420 ◽

1975 ◽

Author(s):

A. J. Johnson ◽

V. E. Macdonald ◽

D. Brandt ◽

S. Middleton ◽

J. K. Smith

Keyword(s):

Side Effects ◽

Antithrombin Iii ◽

Coagulation Factors ◽

Thrombin Time ◽

Average Yield ◽

Clotting Time ◽

Clotting Factors ◽

Partial Activation ◽

Peg Treatment ◽

Fractionation Method

Well documented thrombotic side effects of II, VII, IX and X concentrates are thought to be due to spontaneous partial activation of one or more coagulation factors. Using the unactivated PTT method of Kingdon and the thrombin time as global assays of activation, we have confirmed this concept. It has been suggested that heparin should be added to the concentrate, but preparations vary in antithrombin content and activated factor. The amount of heparin for each preparation would have to be titrated in order to neutralize the activated factors without anticoagulating the patient. We sought to extend the range of added heparin without producing an anticoagulant effect, by adding heparin to the concentrates prior to use of the PEG fractionation method to remove the hepatitis antigen. Thus, heparin-activated antithrombin III can inhibit activated clotting factors while residual free heparin is removed by PEG fractionation. When 1 unit of heparin per mg of protein in the concentrate was added prior to PEG treatment, the final products from more than 80 runs on 15 batches (3 major manufacturers) were almost invariably neutral; neither anticoagulated nor activated. The thrombin clotting time, when measured, was 6-24 hours. The average yield with use of the PEG fractionation method was 85%; depending on the initial purity of the concentrate, the final product had an additional purification of 1.0-2.5 X that of the starting material.(Supported in part by USPHS Grant HL 15596 and HRC (N.Y.) 1-681.)

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Effect Of Radiologic Contrast Agents On Laboratory Parameters Used In The Evaluation Of Hemostatic Function

10.1055/s-0038-1653079 ◽

1981 ◽

Author(s):

Z Parvez ◽

J Fareed ◽

R Moncada ◽

P Agrawal ◽

H L Messmore

Keyword(s):

Contrast Media ◽

Contrast Agents ◽

Anticoagulant Therapy ◽

Laboratory Tests ◽

Diagnostic Procedures ◽

Study Patient ◽

Thrombin Time ◽

Coagulation Disorders ◽

Transient Effects ◽

Clotting Factors

Coagulation disorders of the intrinsic and extrinsic pathways are monitored by measuring such clotting times as partial thromboplastin time (PTT), prothrombin time (PT), and thrombin time (TT). These laboratory tests reflect the congenital and acquired deficiencies of clotting factors and are used for controlling anticoagulant therapy. We have previously reported that meglumine (cation) in radiologic contrast media (CM) inhibits factor VIII, IX, and thrombin (Fed. Proc. 36 (3), 317, 1977) and consequently prolonges clotting times. The effects of ionic and nonionic CM on pathological plasma were investigated by employing routine clotting assays. Patient plasmas showing PT values >15 secs., were mixed with Renografin-60 (Squibb and Sons, Princeton, New Jersey), P-297, iothalamic acid, and ioxigalic acid (Laboratoire Guerbet, Paris, France) and PTs were then determined. Renografin-60 (30 mg/ml), iothalamic acid (10 mg/ml) and ioxigalic acid (10 mg/ml) produced an increase in the PT values by 60-80% base levels, whereas no such effect was seen with P-297. In normal plasma (NHP), the PT values were elevated only by 5-10%. In another study, patient plasmas showing PTT > 40 secs., were supplemented with CM and the mixtures were assayed for PTT. Except with P-297 there was a 50-60% increase in PTT due to the interactions of ionic CM. Our studies show that during anticoagulant therapy, if clotting assays are performed immediately after radiologic diagnostic procedures, utilizing intravascular contrast agents, erroneous conclusions can be drawn. Our studies have also shown that certain ionic CM can produce transient effects on coagulation parameters and therefore, due consideration be given to the presence of these agents in patients suffering from platelet function defects and other coagulation disorders.

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Evaluation of Five Methods for the Determination of Heparin

10.1055/s-0039-1689490 ◽

1975 ◽

Author(s):

A. Teien ◽

M. Lie

Keyword(s):

Coefficient Of Variation ◽

Antithrombin Iii ◽

Factor Xa ◽

Thrombin Time ◽

Heparin Concentration ◽

Normal Plasma

Heparin was added in vitro to plasma and the heparin content assayed by five clotting methods. The accuracy was lower in pathological than in normal plasma. At a heparin concentration of 0.5 U/ml plasma the coefficient of variation in eleven pathological plasmas was: Polybrene titration 3 per cent, method of Denson and Bonnar 15 per cent, method of Yin et al. 20 per cent, calcium thrombin time 40 per cent. With the APTT method the results ranged from 0.05 U/ml to above 0.6 U/ml (no clotting in five pathological plasmas).At a heparin concentration of 0.05 U/ml plasma, only the calcium thrombin time and the factor Xa methods were sensitive, but the coefficient of variation ranged from 61 to 78 per cent. The influence of the concentration of fibrinogen, antithrombin III and α1-acid glucoprotein was studied. It is concluded that of the methods tested, only polybrene titration gives accurate results in pathological plasmas. This method is, however, laborious and insensitive to heparin concentrations below 0.1 U/ml.

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On the interaction of rabbit antithrombin III with the luminal surface of the normal and deendothelialized rabbit thoracic aorta in vitro

Blood ◽

10.1182/blood.v67.4.878.bloodjournal674878 ◽

1986 ◽

Vol 67 (4) ◽

pp. 878-886

Author(s):

MW Hatton ◽

SL Moar ◽

M Richardson

Keyword(s):

Thoracic Aorta ◽

Antithrombin Iii ◽

Balloon Catheter ◽

Rabbit Aorta ◽

Luminal Surface ◽

High Affinity ◽

Antithrombin Activity ◽

Thrombin Antithrombin Iii Complex

Pure rabbit antithrombin III was isotope labeled (with 125I or 3H) by two different methods; neither procedure caused a loss of antithrombin activity although both methods affected the affinity of the protein for Sepharose-heparin. From segments from freshly excised rabbit aorta, the uptake of isotope-labeled antithrombin III by the endothelium was rapid and saturable, although relatively small compared to the uptake of thrombin; binding of 3H-antithrombin III to the endothelium resembled that of 125I-antithrombin III. Transendothelial passage of antithrombin III into the subendothelial layers (intima-media) was slow and progressive. Endothelium binding was not affected by pretreating the vessel with either heparin, thrombin, or glycosaminoglycan-specific enzymes. Endothelium-bound antithrombin III was not selectively displaced by either heparin or thrombin. In contrast, endothelium-bound thrombin was rapidly dislodged by antithrombin III as a thrombin- antithrombin III complex. The surface of the deendothelialized aorta (ie, subjected to a balloon catheter) bound antithrombin III avidly. Pretreatment of the deendothelialized vessel with glycosaminoglycan- specific enzymes, particularly heparitinase, decreased intima-media binding by up to 80%. 125I-antithrombin III, when bound to the deendothelialized vessel surface, was actively displaced by either heparin, thrombin, or by unlabeled antithrombin III. The relatively poor binding of antithrombin III compared with that of thrombin by the endothelium in vitro supports an earlier proposal (Lollar P, Owen WG: J Clin Invest 66:1222–1230, 1980) that thrombin bound to high-affinity sites, possibly pericellular proteoglycan, of the endothelium is inactivated by plasma antithrombin III in vivo. Such a situation probably holds for large arteries at least.

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