Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0220723 (PCA)
 4,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tissue factor (TF) is the physiological initiating mechanism for blood coagulation. Platelets play an important role in monocyte TF expression, thrombosis and inflammation. Aspirin, clopidogrel and cilostazol, which inhibit platelet responses by different mechanisms, are widely used in patients with arterial diseases. We tested the hypothesis that platelet-inhibiting agents inhibit the levels of circulating TF procoagulant activity (TF-PCA) in patients with peripheral arterial disease (PAD). Twenty-six patients with lower extremity PAD, average age 65.9 +/- 8.4 years (mean +/- SEM), were studied at baseline and following sequential two-week treatment regimens with aspirin (325 mg daily), clopidogrel (75 mg daily) or a phosphodiesterase inhibitor cilostazol (100 mg twice daily) singly, and with each possible combination of these agents. Circulating TF-PCA in whole blood, and plasma factor VIIa, prothrombin fragment F1.2, thrombin-antithrombin complexes (TAT), and P-selectin were measured. Baseline TF-PCA levels in the patients were elevated (131 +/- 19 U/ml) compared to control subjects (23 +/- 2, p < 0.0001). TF-PCA levels declined following treatment with clopidogrel alone, and with combinations of clopidogrel with aspirin or cilostazol, with the lowest levels being with the triple-drug combination. Plasma P-selectin declined in all treatment groups. No changes were noted in plasma factor VIIa, F1.2 or TAT. In conclusion, treatment of PAD patients with antiplatelet agents decreases circulating TF, a molecule with prothrombotic and proinflammatory effects. These findings suggest an unrecognized mechanism, beyond inhibiting aggregation responses, for the efficacy of antiplatelet drugs in patients with arterial diseases.
 ...
PMID:Effect of antiplatelet agents clopidogrel, aspirin, and cilostazol on circulating tissue factor procoagulant activity in patients with peripheral arterial disease. 1713 67

The tissue factor (TF) pathway is the primary mechanism for initiation of blood coagulation. Circulating blood contains TF, which originates mainly from monocytes and is thrombogenic. The presence of somatostatin (SMS) receptors on monocytes suggests the possibility that SMS may regulate TF synthesis and/or release. Circulating TF procoagulant activity (TF-PCA), factor VIIa activity (FVIIa; clotting assays), TF antigen (TF-Ag; ELISA), prothrombin fragment 1.2 (F1.2), thrombin-antithrombin complexes (ELISAs), CD40 ligand expression on platelets, and monocyte-platelet aggregates (flow cytometry) were determined in blood from normal volunteers undergoing 24 h of basal glucose/basal insulin (BG/BI) clamps and high-glucose/high-insulin (HG/HI) clamps with and without SMS. Infusions of SMS under basal conditions (BG/BI) raised TF-PCA 1.8-fold (P < 0.03), TF-Ag 2.3-fold (P < 0.001), and TF expression on monocytes by 36% (P < 0.001) and decreased plasma levels of FVIIa by 30% (P < 0.001). Infusion of SMS reduced the 8.6-fold HG/HI-induced increase in TF-Ag by 26% and the 8.6-fold increase in TF-PCA by 100%. SMS also prevented the 60% increase in TF expression on monocytes, the 2.2-fold increase in F1.2, the 40% increase in CD40L expression on platelets, and the 17% increase in monocyte-platelet aggregates seen during HG/HI. We conclude that SMS completely prevented HG/HI-induced TF activation in normal volunteers and may be of use to reduce the procoagulant state and acute vascular events in hyperinsulinemic insulin-resistant patients with type 2 diabetes.
 ...
PMID:Differential effects of somatostatin on circulating tissue factor procoagulant activity and protein. 1721 71

Alterations in blood coagulation may explain the poorer neurological outcome with diabetes mellitus and hyperglycemia after acute ischemic stroke. We studied the relationships between diabetes mellitus, hyperglycemia, whole blood tissue factor procoagulant activity (TF-PCA) and plasma factorVIIa (FVIIa) in ten patients with type 2 diabetes mellitus and 11 non-diabetic patients at baseline and 6, 12, 24, and 48 hours (h) after presentation for acute stroke. In addition, we examined plasma prothrombin fragment 1+2 (F1.2) and thrombin-antithrombin complexes (TAT) as markers of thrombin generation. Stroke severity, assessed by National Institute of Health Stroke Scale (NIHSS), was similar at baseline (p=0.26) but worse in diabetic (8.20+/-4.3) than nondiabetic patients (2.67+/-2.1, p=0.023) at 48 h. At presentation, diabetic patients had higher FVIIa (p=0.004) and lower TF-PCA (p=0.027) than non-diabetic patients but both were higher than in normal control subjects. FVIIa levels remained higher in diabetic patients at 6, 12 and 24 h after stroke. In diabetic patients, FVIIa (r=0.40, p=0.02) and TF-PCA (r=0.50, p=0.02) correlated with blood glucose; and, FVIIa correlated with plasma F1.2 (r=0.34, p=0.002) and TAT levels (r=0.62, p<0.0001). In non-diabetic patients, TF-PCA, but not FVIIa, correlated with F1.2 (r=0.402, p=0.010) and TAT (r=0.39, p=0.011). Combining both groups, NIHSS scores were positively related to FVIIa levels (r=0.50, p=0.021) and inversely related to TF-PCA levels (r=-0.498, p=0.02). Acute ischemic stroke patients with diabetes and hyperglycemia have a more intense procoagulant state compared with nondiabetic patients. This is related to glucose levels and provides a potential mechanism for the observed worse prognosis in such patients after acute stroke.
 ...
PMID:Factor VIIa and tissue factor procoagulant activity in diabetes mellitus after acute ischemic stroke: impact of hyperglycemia. 1800 Jun 5