Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Defibrotide, a deoxypolyribonuclide, has been found to modulate endothelial cell function causing increase in t-PA and decrease in PAI levels and also increase in PGI2 production. In addition, it increases platelet c-AMP levels and decreases MDA and TXB2 formation in human. Defibrotide inhibits platelet aggregate formation in vitro experiments as well as end-to-end anostomosis in rats. So, defibrotide inhibits the activation of platelets. Besides an increase of protein C and S levels a synergic action of heparin was observed in animal experiments. A strong antithrombotic effect has been observed in animal models. The drug has a beneficial effect in the cases of DVT, POVD, stroke and thromboembolism. Through its action we may say that the drug acts in a novel fashion in contrast to the other drugs used in this area. Defibrotide is a single-stranded polydeoxyribonucleotide obtained from deoxyribonucleic acid of mammalian lungs by controlled depolimerization. Since 1981 in our laboratory and in the clinical department we have been investigating a newly developed agent defibrotide in vitro experiments, animal experiments, and also its clinical pharmacology and clinical application. Some of our findings are already published and compared with literature (40, 43, 46). Because of the limited space we are not going to review the literature in detail but we are going to summarize our observations on this compound in the following order. I--in vitro experiments, II--Animal experiments, III--clinical pharmacology in human.
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PMID:The pharmacology and clinical pharmacology of defibrotide: a new profibrinolytic, antithrombotic and anti-platelet substance. 210 24

Plasma tissue-type plasminogen activator and plasminogen activator inhibitor were determined during the acute, recovery and sequelae stages of patients with ischemic stroke by chromophoric substrate assay. The result showed that t-PA activity was elevated during the acute phase, remained elevated during the recovery stage and declined during the sequelae stage. Lowering of PAI activity was found during acute phase, which reversed during recovery phase and remained significantly elevated during sequelae stage. As a result, the ratio of PAI/t-PA fluctuated during different stages of the disease. Significant elevation of PAI and PAI/t-PA ratio during sequelae stage may be one of the risk factors of further thrombosis and contribute partly to the high relapsing rate of the disease. In addition, a positive correlation was found between PAI and serum cholesterol content.
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PMID:[Determination of plasma tissue type plasminogen activator and plasminogen activator inhibitor activity in patients with ischemic stroke]. 212 60

The antiplatelet effects of aspirin and ticlopidine were studied by a dual-tracer method, using indium-111 labeled platelets and technetium-99m human serum albumin, in a group of 12 patients with suspected ischemic cerebrovascular disease. The magnitude of platelet accumulation at the carotid bifurcation was expressed as the ratio of radioactivity of indium-111 platelets deposited on the vascular wall to those circulating in the blood-pool (PAI, platelet accumulation index), 48 hr after injection of labeled platelets. PAI values were measured before (baseline studies) and after the antithrombotic therapies (aspirin studies: 325 mg bid for 22.3 +/- 1.3 days, ticlopidine studies: 100 mg tid for 21.8 +/- 2.1 days). At the baseline, the mean PAI value at 24 carotid bifurcations in the patient group was 15.7 +/- 15.3% (mean +/- S.D.) compared to -4.3 +/- 9.1 at 24 carotid bifurcations in 12 normal subjects (p less than 0.01). We defined the upper limit for a normal PAI (%) value to be +13.9, namely the mean PAI plus 2 SD for the carotid bifurcation in normal subjects and used this value for semiquantitative analysis. At the baseline, significant elevation of PAI (more than 13.9%; positive scintigram) was observed at 12 of 24 vessels, while 12 other regions were negative (less than 13.9%). In the lesions with positive scintigraphic results at the baseline, the mean PAI (%) value from the baseline, aspirin and ticlopidine studies was 29.5 +/- 7.0, 11.2 +/- 8.5 (p less than 0.01 versus baseline) and 21.4 +/- 21.3 (not significant from baseline), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Stroke
PMID:Effect of aspirin and ticlopidine on platelet deposition in carotid atherosclerosis: assessment by indium-111 platelet scintigraphy. 381 Jul 24

The authors investigated the behaviour of some markers of the haemostatic balance in a group of patients with acute focal cerebral vasculopathy. The series consists of 70 female patients (mean age: 61 +/- 5), 25 of whom suffering from TIA and 45 from thrombotic stroke; 40 normal controls (mean age 43 +/- 5) were also considered. For each patient after an overnight fasting a withdrawal of venous blood was done within 24-36 hours after the admission. For each sample the determination of seven prothrombotic markers [(fibrinogen (F), factor VII (F VII), antithrombin III (AT III), protein C (PC), protein S (PS) (coagulometric method IL), tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1) (ELISA method Boehringer)] and of three prethrombotic markers [(fibrinopeptide A (FPA), beta-thromboglobulin (BTG) and D-dimer (D-D) (ELISA method, Boehringer)] was performed. The results obtained in the group of the cerebrovasculopathic patients compared to the controls showed a significant increase of F (p < 0.001), F VII (p < 0.005), BTG (p < 0.05) and D-D (p < 0.01), whereas significant differences regarding AT III, PC, PS, t-PA, PAI and FPA were not observed. The authors hypothesized that the increased levels of fibrinogen and factor VII in the cerebrovascular subjects, globally considered, may depend on a marked prothrombotic state, linked in a pathogenetic sense to the vascular disease; the existence of a prethrombotic state is also documented by the increase of betathromboglobulin and D-dimer.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Haemostatic balance in patients with acute focal cerebral vasculopathy. 760 35

The fibrinolytic activity status of the patients with cerebral infarction can affect their clinical prognosis. In this case-controlled study, the plasma fibrinolytic system activities in 30 cases of cortical artery territory cerebral infarction (CACI) and 32 cases of perforating artery territory cerebral infarction (PACI) with a disease duration less than 3 days were assayed with a comprehensive panel including the plasma tPA activity, PAI activity, tPA releasing capacity from vascular endothelium and PAI/tPA ratio values. 30 subjects without cardiovascular and cerebrovascular disorders were served as control. The results showed that the plasma fibrinolytic system activities of the patients with aforementioned two subtypes of cerebral infarction were significantly lower than those of the controls, the results provide a theoretical basis for carrying out thrombolytic therapy in patients with ischemic stroke and suggest that recurrent cerebral infarction might be related to the high activity of plasma PAI.
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PMID:[An analysis on the activity status of fibrinolytic system in Chinese patients with acute cerebral infarction]. 869 8

In the present study, the plasma fibrinolytic activity in 30 cases of cortical artery territory cerebral infarction (CACI) and 32 cases of perforating artery territory cerebral infarction (PACI) within 3 days after ictus, and 30 sex- and age-matched controls without cardio-cerebrovascular diseases were evaluated by a comprehensive panel of assay, including the plasma tPA activity, PAI activity, endothelial capacity of tPA release and PAI/tPA ratio. The results showed that the plasma fibrinolysis and the endothelial potential to release tPA responding to stimulation in both subtypes of the patients were significantly lower than those in the controls, which provide the theoretical basis for carrying out the thrombolytic therapy in the ischemic stroke. And the study also suggested that increased plasma PAI activity could increase the risk of AS thrombotic events with increased serum triglyceride level.
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PMID:Analysis of plasma fibrinolysis in the patients with acute cerebral infarction. 873 55

Although the arterial tree is exposed to increased pressure in hypertensive patients, paradoxically, the complications of hypertension (heart attacks, stroke) are mainly thrombotic rather than hemorrhagic. Patients with left ventricular (LV) hypertrophy are at high risk of the complications of hypertension. We performed a cross-sectional study of 178 patients attending a hypertension clinic in a city center teaching hospital, and measured plasma levels of the soluble adhesion molecule P-selectin (associated with platelet activity/function and atherosclerosis), the von Willebrand factor (vWf; a marker of endothelial dysfunction), fibrin D-dimer (an index of thrombogenesis), plasminogen activator inhibitor (PAI, an index of fibrinolysis), lipoprotein(a) (Lp(a), associated with thrombogenesis and atherogenesis) and hemorheological indexes (fibrinogen, hematocrit, plasma viscosity, hemoglobin) in patients with essential hypertension, in whom the LV mass and LV mass index were determined using echocardiography. The 178 patients (86 men, mean age 54 +/- 15 years) were compared with 47 normotensive healthy controls (aged 56 +/- 20 years). Hypertensive patients had higher P-selectin, PAI, vWf, fibrin D-dimer, Lp(a), plasma fibrinogen, and plasma viscosity when compared with controls. Black hypertensive patients had higher Lp(a) levels and LV septal and posterior wall thickness on echocardiography, but lower plasma PAI levels. Patients with LV hypertrophy (defined as a LV mass index > 134 g/m2 in men or > 110 g/m2 in women) had higher plasma fibrinogen compared with those without LV hypertrophy. Systolic blood pressures were significantly correlated to age, plasma viscosity, plasma fibrinogen, and vWf. Diastolic blood pressures were significantly correlated with age and plasma fibrinogen. Fibrinogen levels were correlated with LV mass, LV mass index, left atrial size, plasma viscosity, and vWf. Fibrin D-dimer levels were significantly correlated with vWf and fibrinogen levels. Thus, hypertensive patients have high plasma fibrinogen levels, thrombogenesis, and impaired fibrinolysis (as indicated by high D-dimer and PAI levels, respectively), platelet activation (raised soluble P-selectin), and endothelial dysfunction (high vWF). The high plasma fibrinogen levels were related to blood pressures, LV mass index (and LV hypertrophy), and left atrial size. These abnormalities in hemorheologic factors and markers of thrombogenesis and endothelial function may act synergistically to increase the risk of thrombogenesis and atherosclerosis in hypertensive patients.
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PMID:Relation of endothelium, thrombogenesis, and hemorheology in systemic hypertension to ethnicity and left ventricular hypertrophy. 941 37

The authors studied whether haemostatic abnormalities connected with the development of cerebral circulatory disturbances can be demonstrated in young stroke patients in whom Doppler and angiographic examination failed to reveal deviations indicative of stroke. They determined the in vivo activation of the coagulation system (TAT, F 1 + 2), the degree of secondary fibrinolysis (D-dimer), the plasma levels of the markers of fibrinolysis, with special regard to inhibitors: plasminogen activator inhibitor (PAI-1), alpha 2 antiplasmin (alpha 2 AP), alpha 2 macroglobulin (alpha 2 M), the frequency of pathologic serum lipoprotein (a)-Lp(a)-values and the association of PAI-1 and Lp(a) with the fibrinolytic system. They conclude that in the acute phase of the disease, the TAT and F 1 + 2 values were significantly elevated compared to the control, without change in the D-dimer value. The results suggest that in the tested period increased thrombin generation dominated and it significantly surpassed plasmin activity since the D-dimer values of that period did not indicate substantial increase in secondary fibrinolysis. The results of the study were separately analyzed in acute, chronic TIA and stroke groups. In the TIA and acute group the F 1 + 2 values, while in stroke the TAT values were more elevated. The in vitro fibrinolytic capacity of the patients significantly decreased compared to controls, showing significant correlation with the Lp(a) level, but not with the PAI value. Examination of the marker molecules renders possible to assess the degree of hypercoaguability and of endogenous lysis. Their knowledge is held important for judging the progression of the disease and the therapeutic consequences.
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PMID:[Hemostatic abnormalities in ischemic stroke]. 981 Jan 64

Recent studies suggest that high plasma levels of tissue-type plasminogen activator (tPA) and its inhibitor (plasminogen activator inhibitor-1, PAI-1) are markers of an increased risk of atherothrombotic ischemic events such as stroke and myocardial infarction. In this prospective study, we measured tPA antigen, PAI-1 antigen and activity, as well as tPA/PAI-1 complex in patients with acute stroke. Stroke subtypes were classified according to the TOAST criteria. From 132 consecutively screened patients, 89 (100%) were enrolled in this study, including 42 patients (47%) with large artery atherosclerosis (LAA), 32 (36%) with small vessel occlusion (SVO), and 15 (17%) with cardioembolism (CE). Nineteen age-matched neurologic patients without manifestations of cerebrovascular disease served as control subjects (CS). Patients with acute stroke had significantly higher plasma levels of tPA antigen (p < 0.001), PAI-1 antigen (p < 0.05) and PAI activity (p < 0.05) than patients in the control group. t-PA antigen, PAI activity and tPA/PAI-1 complex levels were similar regardless of stroke etiology. Only PAI-1 antigen was lower in patients with cardioembolic stroke than in stroke patients with LAA (p < 0.05). Plasma tPA antigen, PAI-1 antigen, and PAI activity are significantly increased in patients with acute ischemic stroke. Except for PAI-1 antigen, this increase appears not to be related to the underlying stroke etiology.
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PMID:Tissue plasminogen activator and plasminogen activator inhibitor in patients with acute ischemic stroke: relation to stroke etiology. 1059 80

Atrial fibrillation (AF) is a well-defined risk factor for ischemic stroke. Patients with lone AF represent a subgroup of AF patients with the lowest lifelong stroke risk. Nonvalvular atrial fibrillation (NVAF) confers a hypercoagulable state resulting in an increased risk of thromboembolism. This study was performed to determine the contributory role of alteration in the hemostatic markers of thrombin generation and fibrinolysis in patients with lone AF during acute ischemic stroke episode. We studied thrombin-antithrombin complexes (TAT), prothrombin fragments 1+2 (F1+2), tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor type-1 (PAI-1) concentrations in patients with acute middle cerebral artery ischemic stroke due to atherosclerotic large artery disease (n=50), lone AF (n=24) and cardioembolism (n=21). The values were compared with those of age-matched control subjects with lone AF and sinus rhythm (n=21 and 15, respectively). The mean F1+2 concentration was higher in the control subjects with lone AF in comparison with those without AF (p=0.014). Patients with stroke due to possible cardioembolism, from lone AF or other causes, had higher TAT (and marginally higher F1+2) concentrations than those with atherosclerotic stroke (p<0.001). tPA concentrations were not different among groups (p=0.89). PAI-I levels were marginally higher in stroke patients with lone AF and atherothrombotic large artery disease compared to the controls without AF (p=0.05). These results suggest that in the acute period of ischemic stroke secondary to lone AF, enhancement of the coagulatory activity occurs as a result of increased thrombin generation, similar to other possible sources of cardioembolism. Observed hemostatic alterations in acute ischemic stroke associated with lone AF may indicate some therapeutic and prognostic implications.
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PMID:Plasma levels of coagulation and fibrinolysis markers in acute ischemic stroke patients with lone atrial fibrillation. 1121 63


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