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1.
J Dr Nurs Pract ; 11(2): 100-106, 2018 Oct.
Article in English | MEDLINE | ID: mdl-32745015

ABSTRACT

BACKGROUND: Little is known about available guidelines that can be used to evaluate health systems' Doctor of Nursing Practice (DNP) capstone projects. OBJECTIVES: The twofold purpose of this study was to identify the scope of nurse executive leadership practices, as demonstrated in final health systems' DNP Projects and propose a framework to guide evaluating health systems' DNP capstone projects. METHODS: This qualitative study used content analysis to evaluate DNP project posters of 10 health systems' DNP students graduating from one Midwestern college of nursing. Students were engaged in activities pertinent to managerial and executive-level nurse leaders. RESULTS: Students were engaged in activities pertinent to both managerial and executive level nurse leaders and followed AONE competencies. Leadership styles were operational and transformational. Six types of activities were identified. Leadership activities and themes were organized into a framework for action that can guide curriculum. CONCLUSIONS: The Framework for Action themes can be used to coach students in nurse manager or executive roles and identify developmental needs of students. IMPLICATIONS FOR NURSING: A specific new competency on impact is indicated. Use of simulation techniques is an opportunity in health systems education.

2.
Sci Transl Med ; 9(371)2017 01 04.
Article in English | MEDLINE | ID: mdl-28053157

ABSTRACT

Antiplatelet agents are proven efficacious treatments for cardiovascular and cerebrovascular diseases. However, the existing drugs are compromised by unwanted and sometimes life-threatening bleeding that limits drug usage or dosage. There is a substantial unmet medical need for an antiplatelet drug with strong efficacy and low bleeding risk. Thrombin is a potent platelet agonist that directly induces platelet activation via the G protein (heterotrimeric guanine nucleotide-binding protein)-coupled protease-activated receptors PAR1 and PAR4. A PAR1 antagonist is approved for clinical use, but its use is limited by a substantial bleeding risk. Conversely, the potential of PAR4 as an antiplatelet target has not been well characterized. Using anti-PAR4 antibodies, we demonstrated a low bleeding risk and an effective antithrombotic profile with PAR4 inhibition in guinea pigs. Subsequently, high-throughput screening and an extensive medicinal chemistry effort resulted in the discovery of BMS-986120, an orally active, selective, and reversible PAR4 antagonist. In a cynomolgus monkey arterial thrombosis model, BMS-986120 demonstrated potent and highly efficacious antithrombotic activity. BMS-986120 also exhibited a low bleeding liability and a markedly wider therapeutic window compared to the standard antiplatelet agent clopidogrel tested in the same nonhuman primate model. These preclinical findings define the biological role of PAR4 in mediating platelet aggregation. In addition, they indicate that targeting PAR4 is an attractive antiplatelet strategy with the potential to treat patients at a high risk of atherothrombosis with superior safety compared with the current standard of care.


Subject(s)
Antibodies/therapeutic use , Fibrinolytic Agents/therapeutic use , Hemorrhage/drug therapy , Platelet Aggregation Inhibitors/therapeutic use , Receptors, Thrombin/antagonists & inhibitors , Administration, Oral , Animals , Blood Platelets/metabolism , Guinea Pigs , HEK293 Cells , Humans , Inhibitory Concentration 50 , Macaca fascicularis , Male , Protein Domains , Receptor, PAR-1/metabolism , Stroke/drug therapy , Thrombin/chemistry , Thrombosis , Treatment Outcome
3.
J Nurs Educ ; 55(2): 113-7, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26814824

ABSTRACT

BACKGROUND: Currently, no doctoral guidelines to teach innovation exist. Using Christensen's theory of disruptive innovation, the five discovery skills used by disruptive innovators provide the framework for designing a leadership development approach to enable and support a mindset to innovate. METHOD: Executive leadership students were provided with didactic content on innovation, were assigned to non-healthcare settings for an anthropological dig to uncover innovative activities, and were provided with reflective prompts to enable a new context for innovation. Faculty collaborated with other fields and took risks to provide new contexts to innovate. RESULTS: Students identified and proposed innovations for current health care issues. Some of the innovations included processes, evaluation methods, data analytics for care design, and patient engagement solutions. CONCLUSION: Faculty crossed borders for field experiences, as well as disciplinary borders. This collaborative seminar demonstrated that it is possible to develop executive nurse leaders to innovate.


Subject(s)
Education, Nursing , Leadership , Iowa , Therapies, Investigational
4.
Hum Mov Sci ; 43: 90-9, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26241334

ABSTRACT

Many children have difficulty producing movements well enough to improve in perceptuo-motor learning. We have developed a training method that supports active movement generation to allow improvement in a 3D tracing task requiring good compliance control. We previously tested 7-8 year old children who exhibited poor performance and performance differences before training. After training, performance was significantly improved and performance differences were eliminated. According to the Dynamic Systems Theory of development, appropriate support can enable younger children to acquire the ability to perform like older children. In the present study, we compared 7-8 and 10-12 year old school children and predicted that younger children would show reduced performance that was nonetheless amenable to training. Indeed, the pre-training performance of the 7-8 year olds was worse than that of the 10-12 year olds, but post-training performance was equally good for both groups. This was similar to previous results found using this training method for children with DCD and age-matched typically developing children. We also found in a previous study of 7-8 year old school children that training in the 3D tracing task transferred to a 2D drawing task. We now found similar transfer for the 10-12 year olds.


Subject(s)
Child Development , Pattern Recognition, Visual , Practice, Psychological , Psychomotor Performance , Age Factors , Biomechanical Phenomena , Child , Female , Humans , Male , Neuropsychological Tests , Transfer, Psychology
5.
J Thromb Thrombolysis ; 40(4): 416-23, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26249722

ABSTRACT

BMS-654457 ((+) 3'-(6-carbamimidoyl-4-methyl-4-phenyl-1,2,3,4-tetrahydro-quinolin-2-yl)-4-carbamoyl-5'-(3-methyl-butyrylamino)-biphenyl-2-carboxylic acid) is a small-molecule factor XIa (FXIa) inhibitor. We evaluated the in vitro properties of BMS-654457 and its in vivo activities in rabbit models of electrolytic-induced carotid arterial thrombosis and cuticle bleeding time (BT). Kinetic studies conducted in vitro with a chromogenic substrate demonstrated that BMS-654457 is a reversible and competitive inhibitor for FXIa. BMS-654457 increased activated partial thromboplastin time (aPTT) without changing prothrombin time. It was equipotent in prolonging the plasma aPTT in human and rabbit, and less potent in rat and dog. It did not alter platelet aggregation to ADP, arachidonic acid and collagen. In vivo, BMS-654457 or vehicle was given IV prior to initiation of thrombosis or cuticle transection. Preservation of integrated carotid blood flow over 90 min (iCBF, % control) was used as a marker of antithrombotic efficacy. BMS-654457 at 0.37 mg/kg + 0.27 mg/kg/h produced almost 90 % preservation of iCBF compared to its vehicle (87 ± 10 and 16 ± 3 %, respectively, n = 6 per group) and increased BT by 1.2 ± 0.04-fold (P < 0.05). At a higher dose (1.1 mg/kg + 0.8 mg/kg/h), BMS-654457 increased BT by 1.33 ± 0.08-fold. This compares favorably to equivalent antithrombotic doses of reference anticoagulants (warfarin and dabigatran) and antiplatelet agents (clopidogrel and prasugrel) which produced four- to six-fold BT increases in the same model. In summary, BMS-654457 was effective in the prevention of arterial thrombosis in rabbits with limited effects on BT. This study supports inhibition of FXIa, with a small-molecule, reversible and direct inhibitor as a promising antithrombotic therapy with a wide therapeutic window.


Subject(s)
Factor XIa/antagonists & inhibitors , Fibrinolytic Agents/pharmacology , Thrombosis/drug therapy , Animals , Bleeding Time , Dogs , Fibrinolytic Agents/chemistry , Humans , Partial Thromboplastin Time , Rabbits , Rats , Species Specificity , Thrombosis/blood
6.
ACS Med Chem Lett ; 6(5): 590-5, 2015 May 14.
Article in English | MEDLINE | ID: mdl-26005539

ABSTRACT

Structure-activity relationship optimization of phenylalanine P1' and P2' regions with a phenylimidazole core resulted in a series of potent FXIa inhibitors. Introducing 4-hydroxyquinolin-2-one as the P2' group enhanced FXIa affinity and metabolic stability. Incorporation of an N-methyl piperazine amide group to replace the phenylalanine improved both FXIa potency and aqueous solubility. Combination of the optimization led to the discovery of FXIa inhibitor 13 with a FXIa K i of 0.04 nM and an aPTT EC2x of 1.0 µM. Dose-dependent efficacy (EC50 of 0.53 µM) was achieved in the rabbit ECAT model with minimal bleeding time prolongation.

7.
J Med Chem ; 57(23): 9915-32, 2014 Dec 11.
Article in English | MEDLINE | ID: mdl-25405503

ABSTRACT

Novel inhibitors of FXIa containing an (S)-2-phenyl-1-(4-phenyl-1H-imidazol-2-yl)ethanamine core have been optimized to provide compound 16b, a potent, reversible inhibitor of FXIa (Ki = 0.3 nM) having in vivo antithrombotic efficacy in the rabbit AV-shunt thrombosis model (ID50 = 0.6 mg/kg + 1 mg kg(-1) h(-1)). Initial analog selection was informed by molecular modeling using compounds 11a and 11h overlaid onto the X-ray crystal structure of tetrahydroquinoline 3 complexed to FXIa. Further optimization was achieved by specific modifications derived from careful analysis of the X-ray crystal structure of the FXIa/11h complex. Compound 16b was well tolerated and enabled extensive pharmacologic evaluation of the FXIa mechanism up to the ID90 for thrombus inhibition.


Subject(s)
Fibrinolytic Agents/chemical synthesis , Imidazoles/chemical synthesis , Indazoles/chemical synthesis , Animals , Crystallography, X-Ray , Fibrinolytic Agents/pharmacokinetics , Fibrinolytic Agents/pharmacology , Humans , Imidazoles/pharmacokinetics , Imidazoles/pharmacology , Indazoles/pharmacokinetics , Indazoles/pharmacology , Models, Molecular , Partial Thromboplastin Time , Rabbits , Thrombosis/prevention & control
8.
J Med Chem ; 57(3): 955-69, 2014 Feb 13.
Article in English | MEDLINE | ID: mdl-24405333

ABSTRACT

Antithrombotic agents that are inhibitors of factor XIa (FXIa) have the potential to demonstrate robust efficacy with a low bleeding risk profile. Herein, we describe a series of tetrahydroquinoline (THQ) derivatives as FXIa inhibitors. Compound 1 was identified as a potent and selective tool compound for proof of concept studies. It exhibited excellent antithrombotic efficacy in rabbit thrombosis models and did not prolong bleeding times. This demonstrates proof of concept for the FXIa mechanism in animal models with a reversible, small molecule inhibitor.


Subject(s)
Factor Xa Inhibitors , Fibrinolytic Agents/chemical synthesis , Quinolines/chemical synthesis , Animals , Bleeding Time , Crystallography, X-Ray , Fibrinolytic Agents/chemistry , Fibrinolytic Agents/pharmacology , Humans , Molecular Conformation , Molecular Docking Simulation , Quinolines/chemistry , Quinolines/pharmacology , Rabbits , Stereoisomerism , Structure-Activity Relationship
9.
Bioorg Med Chem Lett ; 23(11): 3239-43, 2013 Jun 01.
Article in English | MEDLINE | ID: mdl-23602442

ABSTRACT

Preclinical data suggests that P2Y1 antagonists, such as diarylurea compound 1, may provide antithrombotic efficacy similar to P2Y12 antagonists and may have the potential of providing reduced bleeding liabilities. This manuscript describes a series of diarylureas bearing solublizing amine side chains as potent P2Y1 antagonists. Among them, compounds 2l and 3h had improved aqueous solubility and maintained antiplatelet activity compared with compound 1. Compound 2l was moderately efficacious in both rat and rabbit thrombosis models and had a moderate prolongation of bleeding time in rats similar to that of compound 1.


Subject(s)
Fibrinolytic Agents/chemistry , Phenylurea Compounds/chemistry , Purinergic P2Y Receptor Antagonists/chemistry , Pyridines/chemistry , Receptors, Purinergic P2Y1/chemistry , Urea/chemistry , Animals , Caco-2 Cells , Disease Models, Animal , Drug Evaluation, Preclinical , Fibrinolytic Agents/chemical synthesis , Fibrinolytic Agents/pharmacokinetics , Half-Life , Humans , Microsomes, Liver/metabolism , Partial Thromboplastin Time , Phenylurea Compounds/pharmacokinetics , Phenylurea Compounds/therapeutic use , Platelet Aggregation/drug effects , Purinergic P2Y Receptor Antagonists/pharmacokinetics , Purinergic P2Y Receptor Antagonists/therapeutic use , Pyridines/pharmacokinetics , Pyridines/therapeutic use , Rabbits , Rats , Receptors, Purinergic P2Y1/metabolism , Solubility , Structure-Activity Relationship , Thrombosis/drug therapy , Urea/pharmacokinetics , Urea/therapeutic use , Water/chemistry
11.
J Thromb Thrombolysis ; 32(2): 129-37, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21614454

ABSTRACT

BMS-262084 is a 4-carboxy-2-azetidinone-containing irreversible inhibitor of FXIa, which is selective over other coagulation proteases. We evaluated the in vitro and in vivo properties of BMS-262084 in rabbits. Studies were conducted in arteriovenous-shunt thrombosis (AVST), venous thrombosis (VT), electrolytic-mediated carotid arterial thrombosis (ECAT) and cuticle bleeding time (BT) models. BMS-262084 was infused IV from 1 h before thrombus induction or cuticle transection to the end of the experiment. In vitro, BMS-262084 prolonged activated partial thromboplastin time (aPTT) with EC(2x) (concentration required to double aPTT) of 10.6 µM in rabbit plasma, and did not prolong prothrombin time (PT), thrombin time (TT) and HepTest. In vivo, BMS-262084 produced dose-dependent antithrombotic effects in rabbits with antithrombotic ED(50) (dose that reduced thrombus weight or increased blood flow by 50% of the control) in AVST, VT and ECAT of 0.4, 0.7 and 1.5 mg/kg/h IV, respectively. BMS-262084 increased ex vivo aPTT dose-dependently without changes in PT and TT. The antithrombotic effect of BMS-262084 was significantly correlated with its ex vivo aPTT, supporting the use of ex vivo aPTT as a pharmacodynamic biomarker. BMS-262084 did not alter ex vivo rabbit platelet aggregation to ADP and collagen. BT (fold-increase) determined at 3 and 10 mg/kg/h of BMS-262084 were 1.17 ± 0.04 and 1.52 ± 0.07*, respectively (*P < 0.05 vs. control). This study demonstrated that BMS-262084 prevented experimental thrombosis at doses with low BT effects in rabbits, and suggests that a small molecule FXIa inhibitor may represent a promising antithrombotic therapy.


Subject(s)
Azetidines/pharmacology , Factor XIa/antagonists & inhibitors , Fibrinolytic Agents/pharmacology , Piperazines/pharmacology , Platelet Activation/drug effects , Venous Thrombosis/drug therapy , Animals , Azetidines/adverse effects , Bleeding Time , Disease Models, Animal , Drug Evaluation, Preclinical , Fibrinolytic Agents/adverse effects , Male , Piperazines/adverse effects , Platelet Function Tests/methods , Rabbits , Venous Thrombosis/blood
13.
Thromb Haemost ; 101(1): 108-15, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19132196

ABSTRACT

The new P2Y(12) antagonist prasugrel produces greater inhibition of ADP-induced platelet aggregation (IPA) and reduction of thrombotic events in patients versus approved doses of clopidogrel, but increases major bleeding. We examined whether IPA level or P2Y(12) receptor occupancy (RO) could be optimized to better balance the efficacy and bleeding effects of these thienopyridines and reduce the response variability in rabbits. Rabbits were given three daily oral doses of clopidogrel (0.3-30 mg/kg/d), prasugrel (0.03-10 mg/kg/d) or vehicle (n = 6-40/group). Electrically-induced carotid artery thrombosis (AT, % thrombus weight reduction), cuticle bleeding time (BT, fold-increase over control), IPA to 20 microM ADP (% inhibition of peak light transmission) and RO (% inhibition of [(33)P]-2MeS-ADP binding to P2Y(1)-blocked platelets) were determined 2-3 hours after the last dose. ED(50) (doses for half-maximal effect, mg/kg/d) of AT, BT, IPA and RO were 1.6, 6.7, 1.9 and 1.4 for clopidogrel vs. 1.2, 1.9, 0.5 and 0.2 for prasugrel. IPA of 30-40% for both compounds produced the optimal balances of efficacy (AT: 50-60%) and BT of about 2-fold with significant RO of 70-80%. IPA of 50-60% achieved higher efficacy (AT: 60-80%), but with increased BT of five- to six-fold and >90% RO. Box-plot suggests no significant difference in the IPA and RO response variability between both compounds. Clopidogrel was 1.3-7 times less potent than prasugrel in rabbits, depending upon which biomarker was studied. The ratio of efficacy: bleeding was most favorable at a moderate IPA of 30% to 40%. Both compounds had similar IPA and RO response variability.


Subject(s)
Fibrinolytic Agents/pharmacology , Hemostasis/drug effects , Piperazines/pharmacology , Platelet Aggregation Inhibitors/pharmacology , Platelet Aggregation/drug effects , Thiophenes/pharmacology , Thrombosis/drug therapy , Ticlopidine/analogs & derivatives , Adenosine Diphosphate/analogs & derivatives , Adenosine Diphosphate/metabolism , Administration, Oral , Animals , Binding, Competitive , Bleeding Time , Clopidogrel , Disease Models, Animal , Dose-Response Relationship, Drug , Fibrinolytic Agents/administration & dosage , Fibrinolytic Agents/metabolism , Fibrinolytic Agents/toxicity , Hemorrhage/chemically induced , Male , Piperazines/administration & dosage , Piperazines/metabolism , Piperazines/toxicity , Platelet Aggregation Inhibitors/administration & dosage , Platelet Aggregation Inhibitors/metabolism , Platelet Aggregation Inhibitors/toxicity , Prasugrel Hydrochloride , Purinergic P2 Receptor Antagonists , Rabbits , Receptors, Purinergic P2/metabolism , Receptors, Purinergic P2Y12 , Thionucleotides/metabolism , Thiophenes/administration & dosage , Thiophenes/metabolism , Thiophenes/toxicity , Thrombosis/blood , Ticlopidine/administration & dosage , Ticlopidine/metabolism , Ticlopidine/pharmacology , Ticlopidine/toxicity
14.
J Cardiovasc Pharmacol ; 49(5): 316-24, 2007 May.
Article in English | MEDLINE | ID: mdl-17513951

ABSTRACT

Target levels of ex vivo inhibition of platelet aggregation (IPA) induced by adenosine diphosphate (ADP) that produce clinically relevant effects of clopidogrel, a P2Y12 antagonist, are unclear. We examined standard and modified IPA and P2Y12 receptor occupancy as predictors of antithrombotic (% thrombus weight reduction) and bleeding time (BT, fold-increase over control) effects of clopidogrel in rabbit models of carotid artery thrombosis and cuticle bleeding, respectively. Standard and modified IPA with 20 microM ADP were measured in the absence and presence of partial P2Y1 blockade, respectively. Clopidogrel maximally produced standard IPA of 57% +/- 5%, antithrombotic effect of 85% +/- 1%, BT increase of 6.0 +/- 0.4-fold and P2Y12 receptor occupancy of 87% +/- 5%. Surprisingly, a clopidogrel dose that produced a low standard IPA of 17% +/- 4% and P2Y12 receptor occupancy of 39% +/- 5% achieved a significant antithrombotic activity of 55% +/- 2% with a moderate increase in BT of 2.0 +/- 0.1-fold. This underestimation of clopidogrel efficacy by standard IPA was improved by measuring either modified IPA or P2Y12 receptor occupancy. These results suggest that in clopidogrel-treated rabbits, low standard IPA is associated with significant antithrombotic effects. Moreover, modified IPA and P2Y12 receptor occupancy appear to better predict the magnitude of clopidogrel's efficacy compared with standard IPA, which may be a better predictor of BT.


Subject(s)
Blood Platelets/metabolism , Carotid Artery Thrombosis/prevention & control , Carotid Artery Thrombosis/physiopathology , Carotid Artery, Common/drug effects , Platelet Aggregation Inhibitors/pharmacology , Platelet Aggregation/drug effects , Receptors, Purinergic P2/metabolism , Ticlopidine/analogs & derivatives , Adenosine Diphosphate/metabolism , Adenosine Diphosphate/pharmacology , Analysis of Variance , Animals , Aspirin/pharmacology , Biomarkers/blood , Bleeding Time , Blood Platelets/drug effects , Carotid Artery Thrombosis/blood , Carotid Artery, Common/physiopathology , Clopidogrel , Disease Models, Animal , Dose-Response Relationship, Drug , Hemostasis/drug effects , Male , Predictive Value of Tests , Protein Binding/drug effects , Rabbits , Receptors, Purinergic P2/drug effects , Regional Blood Flow/drug effects , Thromboxane B2/blood , Ticlopidine/pharmacology
15.
J Thromb Thrombolysis ; 24(1): 43-51, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17323133

ABSTRACT

Coactivation of platelets and the blood coagulation cascade contributes to the pathophysiology of arterial thrombosis. Combination therapy with antiplatelet and anticoagulant drugs may be needed for maximizing the prevention and treatment of arterial thrombosis. Few studies have thoroughly investigated the combined antithrombotic and bleeding effects of these antithrombotic agents. We, therefore, evaluated the antithrombotic and bleeding profiles of dual and triple therapy with razaxaban, a direct factor Xa inhibitor, plus aspirin and/or clopidogrel in rabbit models of electrolytic injury-induced carotid artery thrombosis and cuticle bleeding time, respectively. Compounds were infused either IV or into the portal vein from 1 h before arterial injury or cuticle transection to the end of experiment. Carotid blood flow was used as a marker of antithrombotic effect. We first evaluated the antithrombotic potency of razaxaban, and examined its ex vivo effects on coagulation parameters to confirm its selectivity. Antithrombotic ED(50) of razaxaban averaged 0.22 +/- 0.05 mg/kg/h (n = 6). Razaxaban at 3 mg/kg/h IV produced full antithrombotic efficacy, increased significantly ex vivo activated partial thromboplastin time and prothrombin time by 2.2 +/- 0.1- and 2.3 +/- 0.1-fold, respectively, and inhibited ex vivo factor Xa activity significantly by 91 +/- 5% (n = 6, P < 0.05) without affecting ex vivo thrombin activity. Razaxaban at concentrations up to 10 muM did not alter in vitro platelet aggregation responses to ADP, gamma-thrombin or collagen. To identify additive or synergistic antithrombotic effects of the various combination therapies, we purposefully used marginally effective doses of razaxaban at 0.1 mg/kg/h, aspirin at 0.3 mg/kg/h and clopidogrel at 1 mg/kg/h. Dual combination of threshold doses of razaxaban and aspirin or clopidogrel produced an enhanced antithrombotic effect without further increases in bleeding time. When compared with dual therapy with aspirin and clopidogrel (38 +/- 5% increase in blood flow), addition of razaxaban increased blood flow to 75 +/- 5% without additional bleeding time effects (n = 6/group, P < 0.05). In summary, razaxaban was an effective antithrombotic agent in a rabbit model of arterial thrombosis. Low-dose razaxaban was useful in combination with sub-optimal doses of aspirin and/or clopidogrel for the prevention of occlusive arterial thrombosis without excessive bleeding.


Subject(s)
Aspirin/therapeutic use , Factor Xa/pharmacology , Fibrinolytic Agents/pharmacology , Hemorrhage/physiopathology , Hemostasis , Isoxazoles/pharmacology , Pyrazoles/pharmacology , Ticlopidine/analogs & derivatives , Animals , Blood Coagulation/drug effects , Clopidogrel , Disease Models, Animal , Drug Therapy, Combination , Male , Platelet Aggregation/drug effects , Rabbits , Thrombosis/prevention & control , Ticlopidine/pharmacology
18.
J Pharmacol Exp Ther ; 303(3): 993-1000, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12438519

ABSTRACT

DPC423 [1-[3-(aminomethyl)phenyl]-N-[3-fluoro-2'-(methylsulfonyl)[1,1'-biphenyl]-4-yl]-3-(trifluoromethyl)-1H-pyrazole-5-carboxamide] is a synthetic, competitive, and selective inhibitor of coagulation factor Xa (fXa) (K(i): 0.15 nM in humans, 0.3 nM in rabbit). The objective of this study was to compare effects of DPC423, enoxaparin (low-molecular-weight heparin), and argatroban (thrombin inhibitor) on arterial thrombosis and hemostasis in rabbit models of electrically induced carotid artery thrombosis and cuticle bleeding, respectively. Compounds were infused i.v. continuously from 60 min before artery injury or cuticle transection to the end of experiment. Carotid blood flow was used as a marker of antithrombotic effect. Antithrombotic ED(50) values were 0.4 mg/kg/h for enoxaparin (n = 6), 0.13 mg/kg/h for argatroban (n = 6), and 0.6 mg/kg/h for DPC423 (n = 12). DPC423 at the maximum antithrombotic dose increased activated partial thromboplastin time and prothrombin time (n = 6) by 1.8 +/- 0.07- and 1.8 +/- 0.13-fold, respectively, without changes in thrombin time and ex vivo thrombin activity. The antithrombotic effect of DPC423 was significantly correlated with its ex vivo anti-fXa activity (r = 0.86). DPC423 at 1, 3, and 10 mg/kg p.o. increased carotid blood flow (percent control) at 45 min to 10 +/- 4, 24 +/- 6, and 74 +/- 7, respectively (n = 6/group). Cuticle bleeding times (percent change over control) determined at the maximum antithrombotic dose were 88 +/- 12 for argatroban, 69 +/- 13 for heparin, 4 +/- 3 for enoxaparin, 5 +/- 4 for DPC423, and -3 +/- 2 for the vehicle (n = 5-6/group), suggesting dissociation of antithrombotic and bleeding time effects for DPC423 and enoxaparin. The combination of aspirin and DPC423 at ineffective antithrombotic doses produced significant antithrombotic effect. Therefore, these results suggest that DPC423 is a clinically useful oral anticoagulant for the prevention of arterial thrombosis.


Subject(s)
Antithrombin III/pharmacology , Carotid Arteries/drug effects , Carotid Artery Thrombosis , Fibrinolytic Agents/pharmacology , Pyrazoles/pharmacology , Sulfones/pharmacology , Administration, Oral , Animals , Antithrombin III/therapeutic use , Aspirin/pharmacology , Bleeding Time , Blood Flow Velocity/drug effects , Blood Flow Velocity/physiology , Carotid Arteries/physiology , Carotid Arteries/physiopathology , Carotid Artery Thrombosis/drug therapy , Carotid Artery Thrombosis/physiopathology , Drug Therapy, Combination , Fibrinolytic Agents/therapeutic use , Male , Partial Thromboplastin Time , Platelet Aggregation/drug effects , Pyrazoles/pharmacokinetics , Pyrazoles/therapeutic use , Rabbits , Regional Blood Flow/drug effects , Regional Blood Flow/physiology , Sulfones/therapeutic use , Thrombin Time
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