Potentially Thrombogenic Materials in Factor IX Concentrates

1975 ◽  
Vol 33 (03) ◽  
pp. 617-631 ◽  
Author(s):  
H. S Kingdon ◽  
R. L Lundblad ◽  
J. J Veltkamp ◽  
D. L Aronson
Keyword(s):  
Human Plasma ◽  
Antithrombin Iii ◽  
Factor Ix ◽  
In Vitro Assays ◽  
Substantial Agreement ◽  
Coefficient Of Correlation

SummaryFactor IX concentrates manufactured from human plasma and intended for therapeutic infusion in man have been suspected for some time of being potentially thrombogenic. In the current studies, assays were carried out in vitro and in vivo for potentially thrombogenic materials. It was possible to rank the various materials tested according to the amount of thrombogenic material detected. For concentrates not containing heparin, there was substantial agreement between the in vivo and in vitro assays, with a coefficient of correlation of 0.77. There was no correlation between the assays for thrombogenicity and the antithrombin III content. We conclude that many presently available concentrates of Factor IX contain substantial amounts of potentially thrombogenic enzymes, and that this fact must be considered in arriving at the decision whether or not to use them therapeutically.

STUDIES ON THE ANTICOAGULANT AND ANTITHROMBOTIC ACTIONS OF DERMATANS AND THEIR SULFATED DERIVATIVES

1987 ◽  
Author(s):  
D Hoppensteadt ◽  
A Kumar ◽  
J Fareed ◽  
J Mardigian
Keyword(s):  
Antithrombin Iii ◽  
Femoral Vein ◽  
In Vivo Studies ◽  
In Vitro Assays ◽  
Protease Inhibition ◽  
Thrombosis Model ◽  
Antithrombotic Effects ◽  
Activated Prothrombin Complex Concentrates

Non-antithrombin III mediated effects such as interaction with heparin cofactor II, modulation of endothelium and polymorphonuclear leukocytes contribute to the overall antithrombotic effects of glycosaminoglycans. In order to study the role of these dermatans, we investigated their in vitro anticoagulant effects using the clot based (PT, APTT, TT, and Heptest), antiprotease (anti IIa and anti Xa) and Thromboplastin C activated fibrinopeptide A generation test. The in vivo antithrombotic actions were investigated, against activated and non activated prothrombin complex concentrates, and in combination with Russells viper venom in jugular and femoral vein stasis thrombosis models (rabbit). The dermatans studied consisted of a standard dermatan of porcine intestinal origin and four sulfated dermatans with varying degrees of sulfation. All of the dermatans studied showed weak anticoagulant effects on the routinely performed clot based assays. Marked variability was seen on the protease inhibition (anti Xa and anti IIa) assays. In the in vivo studies all dermatans studied showed varying degrees of antithrombotic actions against various thrombogenic agents in a modified stasis thrombosis model. Sulfation appeared to produce stronger anticoagulant effects as determined by in vitro assays, whereas the intravenous antithrombotic actions of native dermatan were stronger than sulfated derivatives. This data suggests that dermatans produce their antithrombotic actions via non-antithrombin III mediated pathways. Furthermore, in vitro testing methods are of limited value in the evaluation of the biologic actions of dermatans and their derivatives.

In Vivo And In Vitro Comparisons Of Anti-Inhibitor Coagulant Concentrates (AICC) For Hemophilic Therapy

1981 ◽  
Author(s):  
N Pancham ◽  
M A Fournel ◽  
M H Coan
Keyword(s):  
No Value ◽  
Factor Ix ◽  
In Vitro Assays ◽  
Venous Stasis ◽  
Fviii Inhibitor ◽  
In Vivo Testing ◽  
Order Of Magnitude ◽  
Circulating Antibodies

In FVIII:C deficient persons, who also have circulating antibodies to the molecule, replacement therapy with FVIII concentrates elevates the antibody level and is of limited or no value. Treatment with prothrombin complex concentrates, however, has had varying degrees of success in these patients depending on the significance of the bleed.Currently available Anti-Inhibitor Coagulant Concentrates (AICC), containing factors II, VII, IX, and X in their nonactivated as well as activated forms, have been shown to be effective in controlling bleeds in some of these patients.Two commercially available AICC products and two research preparations were evaluated using conventional in vitro clotting techniques. In vivo assays were also performed in animal systems using the Wessler venous stasis assay. Despite similarities by in vitro assays, striking differences exist in the results obtained using the animal systems. As shown by the Wessler venous stasis assay for in vivo testing, the materials are much more active (at least an order of magnitude) than currently manufactured factor IX concentrates.In vitro clotting assays that are now available (namely factors II, VII, IX, X, IIa, Xa, NAPTT, FVIII correctional activity, and FVIII inhibitor bypassing activity assays) do not necessarily predict the in vivo efficacy of these AICC products. Furthermore, there is no correlation between the FVIII correctional activity and the FVIII inhibitor bypassing activity assays which are now being used to monitor these preparations.

Quantitative Estimation of Thrombin-Antithrombin III and Plasmin-Alpha1-Antiplasmin Complexes in Human Plasma

1975 ◽  
Author(s):  
D. Collen
Keyword(s):  
Human Plasma ◽  
Antithrombin Iii ◽  
Quantitative Estimation ◽  
Low Grade ◽  
Red Cell ◽  
Fresh Plasma ◽  
Clinical Conditions ◽  
Better Than

During activation of the coagulation or fibrinolytic system in human plasma neo-antigens evolve, associated with the thrombin-antithrombin III (T-AT) and plasmin-α1-antiplasmin (P-AP) complexes (D. Collen and P. De Cock, Thromb, Res., 5, 777, 1974), A tanned red cell hemagglutination inhibition immunoassay (TRCHII) has been adapted to the quantitation of these complexes in plasma. Experiments with partially absorbed antisera revealed that fresh plasma had a titer of 4 to 32 in the TRCHII for T-AT and of 4 to 16 in the TRCHII for P-AP. Serum reacted 8 to 16 times better than plasma in the TRCHII for T-AT and urokinase activated plasma 32 to 128 times better than plasma in the TRCHII for P-AP.During streptokinase (SK) therapy in 3 patients (infusion of 600,000 HI Kabikinase® over 30 min) a marked increase in the P-AP complex titer, approaching or equalling that of the subject’s plasma activated in vitro with urokinase, was observed at the end of the SK infusion. The titer remained high during the first three hours and was still higher than the pre-infusion value after 24 hours, suggesting that this complex has a half-life of several hours in vivo. During reptilase therapy in 3 patients (infusion of 2 ml Defibrase® over 1 hour) the P-AP complex titer increased gradually but submaximally over a period of several hours and remained elevated for at least 48 hours, indicating that the plasminogen consumption observed during reptilase therapy is due, at least in part, to a secondary fibrinolytic response.Further studies to show whether these assays can be converted to rapid, simple and specific tests for the diagnosis of low grade or regional in vivo coagulation or fibrinolysis in clinical conditions are in progress.

A in Vivo Assay for Standardizing Heparin Preparations

1979 ◽  
Vol 41 (03) ◽  
pp. 576-582
Author(s):  
A R Pomeroy
Keyword(s):  
In Vitro Assays ◽  
British Pharmacopoeia ◽  
In Vitro Method ◽  
Standard Preparation ◽  
Reliable Estimation ◽  
Assay Procedure ◽  
Accuracy And Precision ◽  
Heparin Preparation

SummaryThe limitations of currently used in vitro assays of heparin have demonstrated the need for an in vivo method suitable for routine use.The in vivo method which is described in this paper uses, for each heparin preparation, four groups of five mice which are injected intravenously with heparin according to a “2 and 2 dose assay” procedure. The method is relatively rapid, requiring 3 to 4 hours to test five heparin preparations against a standard preparation of heparin. Levels of accuracy and precision acceptable for the requirements of the British Pharmacopoeia are obtained by combining the results of 3 to 4 assays of a heparin preparation.The similarity of results obtained the in vivo method and the in vitro method of the British Pharmacopoeia for heparin preparations of lung and mucosal origin validates this in vivo method and, conversely, demonstrates that the in vitro method of the British Pharmacopoeia gives a reliable estimation of the in vivo activity of heparin.

Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse
Keyword(s):  
High Purity ◽  
Time Course ◽  
Prothrombin Complex Concentrate ◽  
Degradation Products ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

Presence and Possible Origin of ɛ(γ-Glutamyl)Lysine Isodipeptide in Human Plasma

1992 ◽  
Vol 67 (01) ◽  
pp. 060-062 ◽  
Author(s):  
J Harsfalvi ◽  
E Tarcsa ◽  
M Udvardy ◽  
G Zajka ◽  
T Szarvas ◽  
...  
Keyword(s):  
Human Plasma ◽  
Fibrinolytic Therapy ◽  
Normal Human Plasma ◽  
Normal Human ◽  
Hplc Technique ◽  
Significant Change

Summaryɛ(γ-glutamyl)lysine isodipeptide has been detected in normal human plasma by a sensitive HPLC technique in a concentration of 1.9-3.6 μmol/1. Incubation of in vitro clotted plasma at 37° C for 12 h resulted in an increased amount of isodipeptide, and there was no further significant change when streptokinase was also present. Increased in vivo isodipeptide concentrations were also observed in hypercoagulable states and during fibrinolytic therapy.

A Comparison of the in Vitro and in Vivo Thrombogenic Activity of Factor IX Concentrates Using Stasis (Wessler) and Non-Stasis Rabbit Models

1980 ◽  
Vol 44 (02) ◽  
pp. 081-086 ◽  
Author(s):  
C V Prowse ◽  
A E Williams
Keyword(s):  
Platelet Rich Plasma ◽  
Thrombus Formation ◽  
Factor Ix ◽  
Coagulation System ◽  
In Vitro Tests ◽  
Clinical Use ◽  
Low Activity

SummaryThe thrombogenic effects of selected factor IX concentrates were evaluated in two rabbit models; the Wessler stasis model and a novel non-stasis model. Concentrates active in either the NAPTT or TGt50 in vitro tests of potential thrombogenicity, or both, caused thrombus formation in the Wessler technique and activation of the coagulation system in the non-stasis model. A concentrate with low activity in both in vitro tests did not have thrombogenic effects in vivo, at the chosen dose. Results in the non-stasis model suggested that the thrombogenic effects of factor IX concentrates may occur by at least two mechanisms. A concentrate prepared from platelet-rich plasma and a pyrogenic concentrate were also tested and found to have no thrombogenic effect in vivo.These studies justify the use of the NAPTT and TGt50 in vitro tests for the screening of factor IX concentrates prior to clinical use.

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

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
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.

Heparin

1985 ◽  
Vol 05 (03) ◽  
pp. 121-126
Author(s):  
L. B. Jaques
Keyword(s):  
Lipoprotein Lipase ◽  
Antithrombin Iii

ZusammenfassungIn vivo bewirkt Heparin das Auftreten einer Lipoprotein-Lipase, einer Diaminoxydase (Histaminase) und anderer Enzyme. In Tierversuchen konnten viele günstige Wirkungen von Heparin und Heparinoiden aufgezeigt werden, wie z.B. Schutzeffekte gegen toxische Medikamente und Prozeduren, gegen Überempfindlichkeitsreaktionen, Änderungen von Hormoneffekten und die Erhöhung der negativen elektrischen Ladung von Körperzellen. Die Einzelwirkungen sind für bestimmte Kettenstrukturen spezifisch. Während Heparin in vitro gerinnungshemmend wirksam ist, zeigt der Vergleich der gerinnungshemmenden Wirkung in der Blutzirkulation mit der chemischen Konzentration im Blut, daß in vivo eine Aktivierung von nicht gerinnungshemmend aktiven Fraktionen bzw. Heparinketten erfolgt. Heparin wird rasch von den Zellen des RES-Systems gegen einen Konzentrationsgradienten aufgenommen, so daß in vivo die Heparinkonzentration im Gefäßendothel lOOOfach höher ist als im Blut.Die Fixierung des Heparins im Endothel vermehrt das elektronegative Potential des Endothels. Diese Wirkung und andere Wirkungen (die Aktivierung von Antithrombin III etc.) sind lokal die Basis der thromboseverhütenden Heparinwirkung. Demnach ist das Endothel das Zielorgan für Heparin.

In-silico Studies of Isolated Phytoalkaloid Against Lipoxygenase: Study Based on Possible Correlation

2018 ◽  
Vol 21 (3) ◽  
pp. 215-221
Author(s):  
Haroon Khan ◽  
Muhammad Zafar ◽  
Helena Den-Haan ◽  
Horacio Perez-Sanchez ◽  
Mohammad Amjad Kamal
Keyword(s):  
In Silico ◽  
Docking Studies ◽  
In Vivo Studies ◽  
In Vitro Assays ◽  
Chronic Obstructive ◽  
Lipoxygenase Inhibitors ◽  
Lipoxygenase Inhibition ◽  
In Silico Studies

Aim and Objective: Lipoxygenase (LOX) enzymes play an important role in the pathophysiology of several inflammatory and allergic diseases including bronchial asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, rheumatoid arthritis and chronic obstructive pulmonary disease. Inhibitors of the LOX are believed to be an ideal approach in the treatment of diseases caused by its over-expression. In this regard, several synthetic and natural agents are under investigation worldwide. Alkaloids are the most thoroughly investigated class of natural compounds with outstanding past in clinically useful drugs. In this article, we have discussed various alkaloids of plant origin that have already shown lipoxygenase inhibition in-vitro with possible correlation in in silico studies. Materials and Methods: Molecular docking studies were performed using MOE (Molecular Operating Environment) software. Among the ten reported LOX alkaloids inhibitors, derived from plant, compounds 4, 2, 3 and 1 showed excellent docking scores and receptor sensitivity. Result and Conclusion: These compounds already exhibited in vitro lipoxygenase inhibition and the MOE results strongly correlated with the experimental results. On the basis of these in vitro assays and computer aided results, we suggest that these compounds need further detail in vivo studies and clinical trial for the discovery of new more effective and safe lipoxygenase inhibitors. In conclusion, these results might be useful in the design of new and potential lipoxygenase (LOX) inhibitors.

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