Genetic polymorphism (Arg353→Gln) in coagulation factor VII gene and factor VII levels (coagulant activity, antigen and binding ability to tissue factor) in 101 healthy Japanese

1995 ◽  
Vol 55 (3) ◽  
pp. 211-215 ◽  
Author(s):  
O. Takamiya
2007 ◽  
Vol 92 (11) ◽  
pp. 4352-4358 ◽  
Author(s):  
Guenther Boden ◽  
Vijender R. Vaidyula ◽  
Carol Homko ◽  
Peter Cheung ◽  
A. Koneti Rao

Abstract Context: Type 2 diabetes mellitus (T2DM) is a hypercoagulable state. Tissue factor (TF) is the principal initiator of blood coagulation. Objective: Our objective was to examine the effects of hyperglycemia and hyperinsulinemia on the TF pathway of blood coagulation in T2DM. Design: Three study protocols were used: 1) acute correction of hyperglycemia (with iv insulin) followed by 24 h of euglycemia, 2) 24 h of selective hyperinsulinemia, and 3) 24 h of combined hyperinsulinemia and hyperglycemia. Setting: The study took place at a clinical research center. Study Participants: Participants included 18 T2DM patients and 22 nondiabetic controls. Results: Basal TF-procoagulant activity (TF-PCA), monocyte TF mRNA, plasma coagulation factor VII (FVIIc), and thrombin-anti-thrombin complexes were higher in T2DM than in nondiabetic controls, indicating a chronic procoagulant state. Acutely normalizing hyperglycemia over 2–4 h resulted in a small (∼7%) but significant decline in TF-PCA with no further decline over 24 h. Raising insulin levels alone raised TF-PCA by 30%, whereas raising insulin and glucose levels together increased TF-PCA (by 80%), thrombin-anti-thrombin complexes, and prothrombin fragment 1.2. Plasma FVIIa and FVIIc declined with increases in TF-PCA. Conclusion: We conclude that the combination of hyperglycemia and hyperinsulinemia, common in poorly controlled patients with T2DM, contributes to a procoagulant state that may predispose these patients to acute cardiovascular events.


2002 ◽  
Vol 363 (2) ◽  
pp. 411 ◽  
Author(s):  
Raffaella TOSO ◽  
Mirko PINOTTI ◽  
Katherine A. HIGH ◽  
Eleanor S. POLLAK ◽  
Francesco BERNARDI

Blood ◽  
2002 ◽  
Vol 99 (8) ◽  
pp. 2794-2800 ◽  
Author(s):  
Diana Bonderman ◽  
Alexander Teml ◽  
Johannes Jakowitsch ◽  
Christopher Adlbrecht ◽  
Mariann Gyöngyösi ◽  
...  

Abstract Defined angiographically, no-reflow (NR) manifests as an acute reduction in coronary flow in the absence of epicardial vessel obstruction. One candidate protein to cause coronary NR is tissue factor (TF), which is abundant in atherosclerotic plaque and a cofactor for activated plasma coagulation factor VII. Scrapings from atherosclerotic carotid arteries contained TF activity (corresponding to 33.03 ± 13.00 pg/cm2 luminal plaque surface). Active TF was sedimented, indicating that TF was associated with membranes. Coronary blood was drawn from 6 patients undergoing coronary interventions with the distal protection device PercuSurge GuardWire (Traatek, Miami, FL). Fine particulate material that was recovered from coronary blood showed TF activity (corresponding to 91.1 ± 62.16 pg/mL authentic TF). To examine the role of TF in acute coronary NR, blood was drawn via a catheter from coronary vessels in 13 patients during NR and after restoration of flow. Mean TF antigen levels were elevated during NR (194.3 ± 142.8 pg/mL) as compared with levels after flow restoration (73.27 ± 31.90 pg/mL; P = .02). To dissect the effects of particulate material and purified TF on flow, selective intracoronary injection of atherosclerotic material or purified relipidated TF was performed in a porcine model. TF induced NR in the model, thus strengthening the concept that TF is causal, not just a bystander to atherosclerotic plaque material. The data suggest that active TF is released from dissected coronary atherosclerotic plaque and is one of the factors causing the NR phenomenon. Thus, blood-borne TF in the coronary circulation is a major determinant of flow.


2019 ◽  
Vol 476 (19) ◽  
pp. 2909-2926
Author(s):  
Tina M. Misenheimer ◽  
Kraig T. Kumfer ◽  
Barbara E. Bates ◽  
Emily R. Nettesheim ◽  
Bradford S. Schwartz

Abstract The mechanism of generation of factor VIIa, considered the initiating protease in the tissue factor-initiated extrinsic limb of blood coagulation, is obscure. Decreased levels of plasma VIIa in individuals with congenital factor IX deficiency suggest that generation of VIIa is dependent on an activation product of factor IX. Factor VIIa activates IX to IXa by a two-step removal of the activation peptide with cleavages occurring after R191 and R226. Factor IXaα, however, is IX cleaved only after R226, and not after R191. We tested the hypothesis that IXaα activates VII with mutant IX that could be cleaved only at R226 and thus generate only IXaα upon activation. Factor IXaα demonstrated 1.6% the coagulant activity of IXa in a contact activation-based assay of the intrinsic activation limb and was less efficient than IXa at activating factor X in the presence of factor VIIIa. However, IXaα and IXa had indistinguishable amidolytic activity, and, strikingly, both catalyzed the cleavage required to convert VII to VIIa with indistinguishable kinetic parameters that were augmented by phospholipids, but not by factor VIIIa or tissue factor. We propose that IXa and IXaα participate in a pathway of reciprocal activation of VII and IX that does not require a protein cofactor. Since both VIIa and activated IX are equally plausible as the initiating protease for the extrinsic limb of blood coagulation, it might be appropriate to illustrate this key step of hemostasis as currently being unknown.


2006 ◽  
Vol 25 (4) ◽  
pp. 209-220
Author(s):  
S.M. Meiring ◽  
C.E. Roets ◽  
P.N. Badenhorst

Die tegniek van faagblootlegging is gebruik om ’n sikliese heptapeptied te selekteer wat met weefselfaktor(WF) kompeteer vir binding aan stollingsfaktor VIIa. Die aminosuurvolgorde van die peptied is Cys-Ala- Trp-Pro-His-Thr-Pro-Asp-Cys (C-AWPHTPD-C) en dit verleng die protrombientyd (PT) op ’n konsentrasie-afhanklike wyse. Die peptied beperk plaatjieklewing aan beide menslike endoteelsel- en weefselfaktormatrikse in ’n vloeikamermodel onder arteriële vloeitoestande. Die peptied funksioneer as ’n volledig mededingende inhibeerder van faktor VIIa met ’n inhibisiekonstante (Ki) van 123,2 μM. In sy huidige vorm is die peptied waarskynlik nie sterk genoeg om verder as antitrombotiese middel ontwikkel te word nie, maar verskillende strategieë kan gevolg word om die werking daarvan te versterk. AbstractFunctional characterisation of a factor VIIa inhibiting peptide, IP-7 selected by phage display technology By using the technique of phage display, we selected a cyclic heptapeptide sequence Cys-Ala-Trp-Pro-His-Thr-Pro-Asp-Cys (C-AWPHTPD-C) that competes with tissue factor for binding to coagulation factor VII. This peptide prolongs the prothrombin time (PT) in a concentration dependent way. It also reduces platelet adhesion to both human endothelial cell and tissue factor matrixes in a flow chamber under arterial flow conditions. Furthermore, it acts as a full competitive inhibitor of factor VIIa with an inhibition constant (Ki) of 123,2 μM. In its current form the peptide is probably not sufficiently potent for development as an antithrombotic agent, but different strategies could be followed to reinforce its performance.


Blood ◽  
1984 ◽  
Vol 63 (2) ◽  
pp. 434-438 ◽  
Author(s):  
GM Rodgers ◽  
GJ Jr Broze ◽  
MA Shuman

Previously, we showed that cells derived from nonvascular tissues initiate clotting primarily by markedly increasing the activity of coagulation factor VII. Cells derived from vascular tissue do not normally exhibit this property (tissue factor activity). In this study, we have characterized the relationship between the tissue factor activity of cultured cells derived from normal tissues and the number of receptors they possess for coagulation factor VII. Only cultured nonvascular cells expressed tissue factor activity or possessed receptors for 125I-factor VII. Fetal lung cells, the nonvascular tissue with the largest amount of procoagulant and tissue factor activity, possessed the most receptors for 125I-factor VII (880,000/cell). Bovine corneal endothelial cells, the nonvascular tissue possessing the fewest number of receptors (2,400/cell), had the least amount of procoagulant or tissue factor activity. The affinity of nonvascular cells for 125I- factor VII varied for the cells studied (Kd congruent to 1.3–90 X 10(- 10) M). Vascular cells expressed no tissue factor activity, nor did they bind 125I-factor VII. 125I-factor VII and unlabeled factor VII bound to cells had identical procoagulant activities. These results indicate that the ability of cultured cells to initiate coagulation may be regulated in part by the number of receptors they possess for factor VII.


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