Anticoagulant Effect Of A New Potent Heparin In Human After Intravenous Application And The Comparison With Commercially Available Heparin

1981 ◽  
Author(s):  
A S Bhargava ◽  
H Wendt ◽  
P Günzel
Keyword(s):  
Human Subjects ◽  
Factor Xa ◽  
Dry Weight ◽  
Parallel Line ◽  
Anticoagulant Effect ◽  
In Vitro Tests ◽  
Thrombin Time ◽  
Relative Potencies

The anticoagulant effect of a new potent heparin containing 83% high affinity and 17% low affinity fractions was compared with commercial heparin after a single i.v. application in human subjects. 20 male and 20 female normal adult subjects participated in this study. 2 male and 2 female subjects per group were treated intravenously with doses ranging from 18.3–218.3 μg for new potent heparin and 40.3–483.0 μg for commercial heparin per kg body weight. Determinations of thrombin time, whole blood clotting time, activated partial thromboplastin time and plasma heparin levels using factor Xa inactivation assay were performed before and 5, 10, 15, 30 and 60 min after heparin application. The regression analysis and parallel line assay were performed using log dose or double log transformation or log dose and square root transformation of areas under the curve to estimate the relative potencies of the new heparin preparation.The new heparin was 1.5 to 2.0 times more effective than commercial heparin per mg dry weight depending upon the coagulation tests used and the length of observation period. These relative potencies of the new heparin in human is in good correlation with relative potencies determined earlier for the same preparation in different in vitro tests including thrombelastography and in vivo using the dog as an experimental animal. In addition, the determinations of biochemical and the haematological parameters, 24h after application indicated no signs of any adverse effect.

Anticoagulant Properties of Three Mucopolysaccharides Used in Rheumatology

1983 ◽  
Vol 50 (03) ◽  
pp. 652-655 ◽  
Author(s):  
F Bauer ◽  
P Schulz ◽  
G Reber ◽  
C A Bouvier
Keyword(s):  
Factor Xa ◽  
Degenerative Joint Disease ◽  
Joint Disease ◽  
Thrombin Time ◽  
Coagulation Tests ◽  
Amplification System ◽  
Relative Potencies ◽  
In Vivo Administration

SummaryThree mucopolysaccharides (MPS) used in the treatment of degenerative joint disease were compared to heparin to establish their relative potencies on 3 coagulation tests, the aPTT, the antifactor X a activity and the dilute thrombin time. One of the compounds, Arteparon®, was one fourth as potent as heparin on the aPTT, but had little or no influence on the 2 other tests. Further in vitro studies suggested that Arteparon® acted at a higher level than factor Xa generation in the intrinsic amplification system and that its effect was independent of antithrombin III. In vivo administration of Arteparon® confirmed its anticoagulant properties, which raises the question of the clinical use of this MPS.

A Comparison of Anticoagulation Activity of a Potent Heparin Preparation in Different Test

1979 ◽  
Author(s):  
A.S. Bhargava ◽  
J. Heinick ◽  
Chr. Schöbel ◽  
P. Günzel
Keyword(s):  
Blood Clotting ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Thrombin Time ◽  
Beagle Dogs ◽  
Clotting Time ◽  
Relative Potencies ◽  
Heparin Preparation

The anticoagulant effect of a new potent heparin preparation was compared with a commercially available heparin in vivo after intravenous application in beagle dogs. The anticoagulant activity was determined using thrombin time, activated partial thromboplastin time and whole blood clotting time after 5, 10 and 30 minutes of application. The relative potency of the new heparin preparation (Scherinq) was found to be 1.62 to 2.52 times higher than heparin used for comparison (150 USP units/mg, Dio-synth). The anticoagulant properties of both preparations were also studied in vitro using dog and human plasma. The relative potencies in vitro correlated well with those obtained in vivo. Further characterization with amidolytic method using chromogenic substrate for factor Xa and thrombin (S-2222 and S-2238 from KABI, Stockholm) showed that heparin (Schering) contains 243 to 378 USP units/raq depending upon the test systems used to assay the anticoagulation activity and in addition, proves the validity of the amidolytic method.

scholarly journals Comparative Studies on the Anticoagulant Profile of Branded Enoxaparin and a New Biosimilar Version

2020 ◽  
Vol 26 ◽  
pp. 107602962096082
Author(s):  
Dalia Qneibi ◽  
Eduardo Ramacciotti ◽  
Ariane Scarlatelli Macedo ◽  
Roberto Augusto Caffaro ◽  
Leandro Barile Agati ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Performance ◽  
Thrombin Generation ◽  
Area Under The Curve ◽  
Factor Xa ◽  
In Vivo Studies ◽  
In Vitro Tests ◽  
Thrombin Time

Low molecular weight heparins (LMWH) represent depolymerized heparin prepared by various methods that exhibit differential, biochemical and pharmacological profiles. Enoxaparin is prepared by benzylation followed by alkaline depolymerization of porcine heparin. Upon the expiration of its patent, several biosimilar versions of enoxaparin have become available. Heparinox (Sodic enoxaparine; Cristália Produtos Químicos Farmacêuticos LTDA, Sao Paulo, Brazil) is a new biosimilar form of enoxaparin. We assessed the molecular weight and the biochemical profile of Heparinox and compared its properties to the original branded enoxaparin (Lovenox; Sanofi, Paris, France). Clotting profiles compared included activated clotting time, activated partial thromboplastin time (aPTT), and thrombin time (TT). Anti-protease assays included anti-factor Xa and anti-factor IIa activities. Thrombin generation was measured using a calibrated automated thrombogram and thrombokinetic profile included peak thrombin, lag time and area under the curve. USP potency was determined using commercially available assay kits. Molecular weight profiling was determined using high performance liquid chromatography. We determined that Heparinox and Lovenox were comparable in their molecular weight profile. Th anticoagulant profile of the branded and biosimilar version were also similar in the clot based aPTT and TT. Similarly, the anti-Xa and anti-IIa activities were comparable in the products. No differences were noted in the thrombin generation inhibitory profile of the branded and biosimilar versions of enoxaparin. Our studies suggest that Heparinox is bioequivalent to the original branded enoxaparin based upon in vitro tests however will require further in vivo studies in animal models and humans to determine their clinical bioequivalence.

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.

scholarly journals Effect ofToona microcarpaHarms Leaf Extract on the Coagulation System

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hao Chen ◽  
Min Jin ◽  
Yi-Fen Wang ◽  
Yong-Qing Wang ◽  
Ling Meng ◽  
...  
Keyword(s):  
Leaf Extract ◽  
Factor Xa ◽  
Adenosine Diphosphate ◽  
Coagulation System ◽  
Dependent Manner ◽  
Thrombin Time ◽  
Antithrombotic Agent ◽  
Thrombin Activity

Toona microcarpaHarms is a tonic, antiperiodic, antirheumatic, and antithrombotic agent in China and India and an astringent and tonic for treating diarrhea, dysentery, and other intestinal infections in Indonesia. In this study, we prepared ethyl-acetate extract from the air-dried leaves ofToona microcarpaHarms and investigated the anticoagulant activitiesin vitroby performing activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) assays. Antiplatelet aggregation activity of the extract was examined using adenosine diphosphate (ADP), collagen, and thrombin as agonists, and the inhibitions of factor Xa and thrombin were also investigated. Bleeding and clotting times in mice were used to determine its anticoagulant activitiesin vivo. It is found thatToona microcarpaHarms leaf extract (TMHE) prolonged APTT, PT, and TT clotting times in a dose-dependent manner and significantly inhibited platelet aggregation induced by thrombin, but not ADP or collagen. Clotting time and bleeding time assays showed that TMHE significantly prolonged clotting and bleeding timesin vivo. In addition, at the concentration of 1 mg/mL, TMHE inhibited human thrombin activity by 73.98 ± 2.78%. This is the first report to demonstrate that THME exhibits potent anticoagulant effects, possibly via inhibition of thrombin activity.

Impact of Antithrombin Deficiency on Efficacies of DU-176b, a Novel Orally Active Direct Factor Xa Inhibitor, and Antithrombin Dependent Anticoagulants, Fondaparinux and Heparin.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1874-1874 ◽  
Author(s):  
Toshio Fukuda ◽  
Yuko Honda ◽  
Chikako Matsumoto ◽  
Nobutoshi Sugiyama ◽  
Tadashi Matsushita ◽  
...  
Keyword(s):  
Thrombus Formation ◽  
Factor Xa ◽  
In Vitro Study ◽  
Antithrombotic Effects ◽  
At Deficiency ◽  
Fxa Inhibitor ◽  
Orally Active ◽  
Relative Potencies

Abstract Antithrombin (AT) is a major physiological inhibitor of coagulation factors, primarily inhibiting thrombin and factor Xa (FXa). Binding of heparin and its related pentasaccharides, fondaparinux, to AT dramatically accelerates inhibition of thrombin and FXa. Entire AT-dependency of heparins may result in decreased anticoagulant effects in patients with inherited or acquired AT deficiencies. Objectives: We have developed an orally active direct (i.e. AT-independent) FXa inhibitor, DU-176b. The objectives of this study were to examine the anticoagulant and antithrombotic effects of DU-176b, fondaparinux, and heparin in heterozygous AT deficient (AT+/−) mice (Refs 1, 2), and to determine the impact of AT deficiency on the efficacies of these anticoagulants. Methods: [In vitro study] Plasma obtained from wild type (AT+/+, C57BL/6J) and AT+/− mice were subjected to measurement of levels of AT antigen and activity. The anticoagulant effects on prothrombin time (PT) and activated partial thromboplastin time (APTT) was measured and the drug concentrations were calculated required to double the clotting time (CT2). [In vivo study] Male AT+/+ and AT+/− mice were fasted over night. Thrombosis was induced in the inferior vena cava by applying filter paper (1 x 5 mm) presoaked in 15% FeCl3 for 10 min. Thrombus was removed 60 min after FeCl3 treatment and its protein content was assessed by Bradford method. DU-176b was orally administered 60 min before, fondaparinux was given s.c. 30 min before, and heparin was injected into the jugular vein 3 min before thrombus induction. Relative potencies of antithrombotic effects in AT+/− mice to those in AT+/+ mice were analyzed by parallel line assay. Results: [In vitro study] Plasma levels of AT antigen and activity in AT+/− mice were deceased to 40% compared with AT+/+ plasma. PT-CT2 of DU-176b was 0.72 μM in AT+/+ plasma and 0.74 μM in AT+/− plasma, respectively, indicating that anticoagulant activity of the direct FXa inhibitor was not affected by heterozygous AT deficiency. APTT-CT2 of fondaparinux and heparin in AT+/+ plasma was 3.8 μM and 14 mU/mL, respectively, whereas APTT-CT2 in AT+/− plasma was 9.2 μM and 20 mU/mL, respectively. Therefore, anticoagulant activities of such AT-dependent inhibitors were attenuated in AT+/− plasma. [In vivo study] All three anticoagulants inhibited venous thrombus formation of AT+/+ mice in dose-dependent manners. In AT+/− mice, the antithrombotic effects of fondaparinux and heparin were less potent than those in AT+/+ mice. In contrast, DU-176b prevented thrombus formation equipotently in both mice. Relative potencies of DU-176b, fondaparinux and heparin were 0.84, 0.40, and 0.70, respectively. Conclusion: DU-176b exerts a comparable antithrombotic effect even in individuals with low plasma AT antigens and activities. Thus, DU-176b may be prioritized over AT-dependent agents for use at the fixed dose in patients with lower plasma AT concentrations.

Generic and Branded Versions of Argatroban Exhibit Differential Anticoagulant Effects In Whole Blood, Plasma Based Assays and Thrombin Generation Assays

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 5129-5129
Author(s):  
Jawed Fareed ◽  
Debra Hoppensteadt ◽  
Omer Iqbal ◽  
Jeanine M. Walenga ◽  
Bruce E Lewis
Keyword(s):  
Protein Interactions ◽  
Whole Blood ◽  
Thrombin Generation ◽  
Conflicts Of Interest ◽  
Anticoagulant Effect ◽  
Thrombin Time ◽  
Clotting Time ◽  
Generic Products

Abstract Abstract 5129 Several generic versions of argatroban) (Mitsubishi; Tokyo, Japan) have been introduced in Japan (Argaron, Gartban, Slovastan). In addition, other generic versions of argatroban are being considered by the European and North American regulatory bodies. While the generic versions of argatroban exhibit similar antithrombin potency (Ki values), because of the differential compositional variations their anticoagulant effects in whole blood systems may differ due to their cellular and plasmatic protein interactions. Branded and generic versions of argatroban may exhibit differential anticoagulant actions in the whole blood and plasma based assays due to their differential interactions with blood cells, platelets and plasma proteins. Three generic versions of argatroban that are commercially available in Japan namely Argaron, Gartban and Slovastan and a powdered version of generic argatroban (Lundbeck) were compared with the branded argatroban. Native whole blood thrombelastographic (TEG) analysis was carried out at 0.1 ug/mL, the Activated Clotting Time (ACT) assay was carried out in a concentration range of 0–10 ug/mL, and such coagulation tests as the PT/INR, aPTT, Heptest, and calcium thrombin time were performed. Plasma retrieved from the supplemented whole blood was also assayed. Ratios of the clotting time test values from whole blood and plasma were calculated. Retrieved plasma samples were also assayed in the thrombin generation assays (TGA). All of the different versions of argatroban produced a concentration dependent anticoagulant effect in the native whole blood TEG and ACT. In the TEG, while argatroban and Slovastan showed a similar effect, Gartban, Argaron and a powdered generic showed weaker effects. Argatroban was also different in the ACT assay. At a concentration of 5 ug/ml the ACTs were, Arg 340+15.2 secs, S 297+10.5 secs, G 292.0+19.1 secs and A 285.2+21.7 secs. In the citrated whole blood systems, all agents produced a concentration dependent anticoagulant effect; however, the generic versions produced a stronger anticoagulant effect in comparison to branded argatroban (p<0.001). In the PT assay at 5 ug/mL, argatroban showed 32 ± 3 sec vs 40–50 sec for the generic products. Similarly in the aPTT, Heptest and thrombin time tests argatroban was weaker than the generic products. Differences among generic versions were also evident. Similar results were obtained in the retrieved plasma, however the ratio of whole blood over plasma varied from product to product. The IC50 of the generic and branded argatrobans in the TGA were also different. These results show that while in the thrombin inhibition assays generic and branded argatroban may show similar effects, these agents exhibit assay dependent differences in the whole blood and plasma based assays. Such differences may be more evident in the in vivo studirs where endothelial cells and other interactions may contribute to product individuality. Therefore, based on the in vitro antiprotease assays, generic argatrobans may not be considered equivalent and require a multi-parametric study. Currently available generic argatrobans may not be equivalent in the in vivo anticoagulant effects. Therefore, clinical validation of the clinical equivalence for these drugs is warranted. Disclosures: No relevant conflicts of interest to declare.

NORMAL APTT IN A PATIENT WITH A PERSISTENT ACQUIRED FACTOR XI INHIBITOR.

1987 ◽  
Author(s):  
R McKenna ◽  
E R Cole ◽  
A Yuk ◽  
W Whisler
Keyword(s):  
White Male ◽  
Cauda Equina ◽  
Operative Management ◽  
In Vitro Tests ◽  
Thrombin Time ◽  
Factor Xi ◽  
Time Activity ◽  
Plasma Factor

A 55 year-old white male (MR) with documented normal hemostatic tests at our institution for 14 years, was admitted for a laminectomy. His pre-operative APTT and prothrombin time activity (Q) were again normal. A prolonged APTT of 58 seconds (21-31 N) and Q of 18% (> . 70% N) was noted on the 14th post-operative day; patient had received I unit PRBC during surgery.Mixtures of pooled normal plasma (NPP) incubated with MR’ s plasma (301, 37° C) yielded normal APTTs with as little as 20% NPP in these mixtures, suggesting a plasma factor(s) deficiency. Factor XI level was undetectable with normal values of factors Vlll-C, IX and XII. A factor XI level of 7% was found in incubated mixtures (60’ , 37° C) of equal parts of NPP + MR’ s plasma as compared to 70% in NPP + buffer and < 1% in MR’ s native plasma + buffer, indicating the presence of an inhibitor in MR’ s plasma. Infusion of 1540 ml of FFP (22 ml/kg) to the patient resulted in an APTT of 28 seconds and a Q of 36% with a persistent undetectable XI (expected ∿ 45%). The in-vivo lack of response to FFP was also suggestive of an inhibitor.Additional in-vitro tests showed that the response of MR’ s plasma was no different from that of NPP with the addition of increasing dilutions of human brain thromboplastin, differentiating this inhibitor from the Lupus type anticoagulant. The severely reduced Q was due to severe temporary reductions in factors II (20%), V (34%), Vll/X (2%) and X (20%) without any evidence of hepatocellular dysfunction or vitamin K deficiency. Fibrinogen, thrombin time, FSP, platelet counts and bleeding times remained normal throughout.There was no external evidence of bleeding after the first operation at any site, despite 1M injections and venepunctures. MR was reoperated on day 15 for a cauda equina hematoma; adequate intra and 72 hour post-operative management was with 1 U FFP Q 6 hourly and Amicar; this was associated with a normal PTT, Q %35% and undetectable XI, but without generalized bleeding. Discontinuation of this regimen resulted in onset of bleeding from drainage tubes only, without bleeding from the rest of the incision. Reinstitution of I U FFP Q 12 hourly and Amicar resulted in a prompt cessation of bleeding. Patient had no evidence for an autoimmune disease, dyspro-teinemia or any other illness. The potential role of the 1 unit of PRBC transfused cannot be discounted. Further data on this inhibitor will be presented.

scholarly journals A Comparative Study of the Effects of Heparin and a Low Molecular Weight Semi-Synthetic Heparin Analogue Upon Platelet Function

1977 ◽  
Author(s):  
R. Michalski ◽  
D. A. Lane ◽  
V. V. Kakkar
Keyword(s):  
Molecular Weight ◽  
Intravenous Injection ◽  
Platelet Function ◽  
Factor Xa ◽  
In Vitro Tests ◽  
Low Molecular Weight ◽  
Clotting Time ◽  
Induced Aggregation

We have already reported O) some in vitro and in vivo properties of a low molecular weight glycosaminoglycan polysulphate. It was found that while this semi-synthetic heparin analogue (SSHA) was virtually inactive in a number of in vitro clotting assays, following intravenous or subcutaneous injection it has a more specific anti-Xa potentiating effect than heparin. In the present communication a comparison has been made of some effects of SSHA and heparin upon platelet function. In several of the in vitro tests performed, such as their potentiating effect on ADP and adrenaline induced aggregation and their effects on the aggregation of washed platelets by Factor Xa, heparin proved to be far more potent than SSHA. It was found that after intravenous injection of both drugs, PRP samples containing comparable anti-Factor Xa activities responded differently to the addition of thrombin as SSHA barely inhibited thrombin induced aggregation. Similarly, SSHA had little effect on the dilute thrombin clotting time of plasma, following intravenous injection. Heparin and analogue were neutralised to approximately the same degree by a crude PF4 preparation, and similar transient thrombocytopenia effects were observed with both drugs.

scholarly journals The in Vivo Evaluation of the Hemostatic Function of Stored Human Platelets

1977 ◽  
Author(s):  
M. Blajchman ◽  
A. Senyi ◽  
J. Hirsh
Keyword(s):  
Platelet Count ◽  
Platelet Function ◽  
Bleeding Time ◽  
Human Subjects ◽  
Human Platelets ◽  
In Vitro Tests ◽  
In Vivo Evaluation ◽  
Ethyl Palmitate

The assessment of the hemostatic function of stored human platelets is difficult to assess in human subjects. The use of thrombocytopenic rabbits treated with ethyl palmitate to produce reticuloendothelial blockade, has made it possible to study the hemostatic function of human platelets in vivo. The assessment of hemostatic function has been made using both a jugular bleeding time technique and an ear bleeding time technique, and in both, a close correlation between bleeding time and platelet count has been established. Using both methods, both fresh and human platelets stored for 72 hours at 22°C correct the bleeding time of thrombocytopenic animals to levels appropriate to the platelet count achieved. Platelets stored at 4°C using standard methods of preparation and storage were ineffective hemostatically after 24 hours storage. Platelets prepared and stored at 4°C at a pH of 6.4 were hemostatically effective in thrombocytopenic rabbits for as long as 10 days of storage. No correlation, however, was noted between the hemostatic effect of stored platelets and in vitro tests of platelet function. Similarly, the intravenous infusion of ADP and collagen produced similar falls in platelet count for both hemostatically effective and non-effective platelets. These studies provide further evidence for the limitations of in vitro tests of platelet function for the assessment of the potential in vivo function of stored human platelets. Furthermore, these findings raise the possibility for the prolongued liquid storage of human platelets at conditions which minimize bacterial contamination, yet maintain hemostatic efficacy.

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