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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the effect of antiplatelet therapy not only on the secondary prevention of stroke but also on the suppression of vascular damages in patients with cerebral thrombosis at the chronic phase. We measured von Willebrand factor (vWF) as a marker for the endothelial system, and coagulation and fibrinolytic parameters in addition to platelet functions. The platelet aggregation and markers for platelet activation were monitored for the adequate inhibition of platelets. Twenty-one patients were treated with 200 mg ticlopidine. 9 patients with 100 mg ticlopidine and 60-150 mg acetylsalicylic acid, and 18 patients with 200 mg cilostazol daily. The mean duration of follow up was 8.4 +/- 3.0 months. A patient was attacked by a recurrent stroke, but no fatal vascular events occurred during the period. A significant decrease was observed in the collagen- and ADP-induced platelet aggregation and markers for platelet activation such as platelet factor 4 (PF4) and beta-thromboglobulin (beta TG) by the antiplatelet therapy. In addition, the activities of coagulation factor VIII (FVIII) and vWF, markers for vascular damages, showed a significant decrease. The results suggest that the antiplatelet therapy could ameliorate the vascular damage through the inhibition of platelet function. Moreover, thrombin-antithrombin III complex (TAT) and alpha 2-plasmin inhibitor-plasmin complex (PIC), markers for the activation of coagulation and fibrinolytic systems, decreased significantly, suggesting that the treatment inhibits the activation of coagulation and fibrinolytic systems induced by the platelet activation. The activities of FVIII and vWF decreased significantly when the level of beta TG or that of PF4 lowered sufficiently by the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Antiplatelet therapy in patients with cerebral thrombosis at the chronic phase--assessment of its effect on coagulation and fibrinolytic parameters]. 799 82

The effects of hyperthermia on potentially prothrombotic endothelial function were investigated by measuring levels of von Willebrand factor, thrombospondin, tissue plasminogen activator and plasminogen activator inhibitor-1 secreted by unstimulated human umbilical vein endothelial cells cultured at 37 degrees C, 39 degrees C, 41 degrees C and 43 degrees C for 24 h. Endothelial barrier function at 43 degrees C was compared with that at 37 degrees C by measuring permeability to radiolabelled human serum albumin and low density lipoprotein. Thrombospondin levels were unaffected by a temperature of 39 degrees C; they increased after 3 h at 41 degrees C and subsequently declined to values significantly below the 37 degrees C control. At 43 degrees C, secretion exhibited a time-dependent decrease. Secretion of von Willebrand factor was not discernibly affected by exposure to 39 degrees C or 41 degrees C. Its response to 43 degrees C resembled that of thrombospondin to 41 degrees C. In contrast, elevated temperatures markedly increased plasminogen activator inhibitor-1 while decreasing t-PA secretion, though after prolonged exposure to 43 degrees C the levels of both returned to control values. After 12-24 h at 43 degrees C, endothelial permeability to both albumin and low density lipoprotein increased markedly. Vascular endothelium may contribute to the thrombotic tendency associated with heat stroke by increasing access to the prothrombotic subendothelium and reducing fibrinolysis.
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PMID:The effects of hyperthermia on human endothelial monolayers: modulation of thrombotic potential and permeability. 805 50

Lipoprotein(a) (Lp[a]) is a newly recognized risk factor for the development of coronary heart disease and stroke in human beings; however, the mechanisms by which Lp(a) increases the risk of coronary heart disease remain unclear. The purpose of this study was to examine the effects of Lp(a) on the occurrence of occlusive arterial thrombosis. Occlusive arterial thrombus formation was examined in 18 cynomolgus monkeys with high plasma Lp(a) concentrations (> 35 mg/dL, n = 6), intermediate Lp(a) concentrations (20-25 mg/dL, n = 6), and low Lp(a) concentrations (< 12 mg/dL, n = 6). A Goldblatt clamp was positioned around the left common carotid artery to produce a stenotic segment, and the artery was pinch-injured with needle holders. A 20-MHz Doppler velocity crystal, placed distal to the stenosis/injury site, was used to detect cyclic flow reductions (indicative of transient thrombosis) or permanent cessation of flow velocity (indicative of more stable occlusive thrombosis). All monkeys with high Lp(a) concentrations developed permanent cessation of flow, whereas only one of six arteries from low-Lp(a) monkeys developed permanent cessation of flow (p < 0.05). Arteries from monkeys with intermediate Lp(a) concentrations developed pronounced cyclic reductions of flow but did not progress to permanent cessation of flow. There were no differences in plasma von Willebrand factor activity among the three groups. Immunohistochemical analysis of the damaged arterial segments indicated incorporation of Lp(a) into the adventitia, media, and intima of arteries from monkeys with low and high plasma Lp(a) concentrations, as well as the presence of an occlusive thrombus in arteries that developed permanent cessation of flow.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Occlusive arterial thrombosis in cynomolgus monkeys with varying plasma concentrations of lipoprotein(a). 846 90

"Silent" lacunar stroke, often found in the elderly, has been proposed as a predisposing condition for clinically overt stroke. However, the risk factors related to this condition have not been studied thoroughly. We conducted brain magnetic resonance imaging and measured the levels of fibrinogen, molecular markers of coagulation activation [prothrombin fragment 1 + 2 (F1 + 2)] and endothelial cell damage [von Willebrand factor (vWF) and thrombomodulin], and lipid profiles including lipoprotein (a) [Lp(a)] in 178 asymptomatic, high-risk, Japanese subjects aged 44 to 93 years. We also studied 32 symptomatic patients with lacunar stroke (symptomatic lacunar group). The prevalence of silent lacunar stroke increased with age up to 85 years but decreased with age in those 85 years old and older. Of the 160 elderly subjects ( > or = 60 years) 84 (53%) had > or = 1 lacunar infarcts (silent lacunar group) and the remaining 76 were considered as the nonlacunar group. Fibrinogen and F1 + 2 levels in the silent lacunar group were significantly higher than those in the nonlacunar group (P < .01). Mean Lp(a) levels and the prevalence of subjects with an Lp(a) level > 30 mg/dL were significantly higher in the symptomatic lacunar group than the nonlacunar group (P < .05), whereas these levels in the silent lacunar group were intermediate to those of the other two groups. When we further classified the silent lacunar group into three subgroups based on the number of lacunes (few lacunes, 1 or 2; moderate number of lacunes, 3 or 4; and numerous lacunes, > or = 5), levels of Lp(a), F1 + 2, vWF, and thrombomodulin were significantly higher and Lp(a) levels > 30 mg/dL more common in the numerous-lacune than in the few-lacune subgroup. We conclude that silent lacunar stroke is often found in asymptomatic, high-risk, elderly Japanese patients and that silent multiple lacunar stroke is associated with hypercoagulability, endothelial cell damage, and high Lp(a) levels.
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PMID:'Silent' cerebral infarction is associated with hypercoagulability, endothelial cell damage, and high Lp(a) levels in elderly Japanese. 864 Apr

In hypertensive vascular lesions, various pathologic changes are exhibited. To clarify the mechanisms responsible for this diversity of vascular lesions, we immunohistochemically examined hypertensive vascular lesions in stroke-prone spontaneously hypertensive rats with reference to the distribution of macrophage subsets. The brain, kidney, heart, and aorta were dissected from stroke-prone spontaneously hypertensive rats and Wistar-Kyoto rats at 8, 12, 16, and 20 weeks of age. Immunohistochemistry was performed with antibodies against the macrophage markers ED1, ED2, and OX42, the MHC class II antigen marker OX6, the T-lymphocyte markers CD4, CD5, and CD8, and other markers, such as alpha-smooth muscle actin, proliferating cell nuclear antigen, and von Willebrand factor. Fibrinoid necrosis was dominant in the brain, and fibrocellular proliferative lesions were dominant in the kidney. Immunohistochemically, the decreased intensity of alpha-smooth muscle actin immunostaining preceded the formation of vascular lesions. Although preexisting ED2-positive perivascular resident macrophages completely disappeared in fibrinoid necrosis, MHC class II-negative and ED1-positive macrophages were scattered around the lesion and showed phagocytosis in the brain, which indicates that macrophages in fibrinoid necrosis had extravasated and acted only as scavengers. In the kidney, there was extensive accumulation of MHC class II-positive and ED1-positive macrophages with T lymphocytes along the affected arteries. These inflammatory cells seemed to be supplied through the perivascular interstitial space, not through the endothelium, and the accumulation of these cells preceded the development of fibrocellular proliferative lesions. In the heart and aorta, macrophage accumulation was either absent or slight, and vascular lesions were rarely observed. These findings suggest that heterogeneity in the time course of macrophage infiltration and in the distribution of macrophage subsets among the vascular trees of various organs seems to be correlated with the diversity of hypertensive vascular lesions. Differences in the routes that supply macrophages and their functions may determine the pathologic changes in the vascular lesions.
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PMID:Heterogeneity in the appearance and distribution of macrophage subsets and their possible involvement in hypertensive vascular lesions in rats. 876 13

The baseline examination (1987-1989) for the Atherosclerosis Risk in Communities (ARIC) Study was conducted in 15,792 free-living residents aged 45-64 years in four geographically dispersed US communities. A questionnaire on symptoms of transient ischemic attack (TIA) and stroke was evaluated by computer algorithm for 12,205 of these participants. Data were also collected on lipoprotein levels, hemostasis, hematology, anthropometry, blood pressure, medical history, lifestyle, socioeconomic status, and medication use. Noninvasive high resolution B-mode ultrasonographic imaging was used to determine carotid arterial intimal-medial wall thickness (IMT). The cross-sectional relation between the prevalence of TIA/stroke symptoms and putative risk factors was assessed by logistic regression, controlling for age and community. Odds ratios for TIA/stroke symptoms were significantly elevated (p < or = 0.01) for diabetes mellitus, current smoking, hypertension, lower levels of education, income, and work activity, and higher levels of lipoprotein(a), IMT, hemostasis factor VIII, and von Willebrand factor. However, the relations with education and carotid IMT were not present for black Americans. In whites, the relations of TIA/stroke symptoms to IMT were nonlinear. Only at extreme levels of IMT were symptoms substantially more frequent: For example, men with an IMT greater than 1.17 mm or women with an IMT greater than 0.85 mm had approximately twice the odds of having positive TIA/stroke symptoms as those with lower IMTs. The authors plan in future analyses to address the issue prospectively, as well as to examine the relation with magnetic resonance imaging-defined outcomes and clinically defined incident stroke.
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PMID:Association of transient ischemic attack/stroke symptoms assessed by standardized questionnaire and algorithm with cerebrovascular risk factors and carotid artery wall thickness. The ARIC Study, 1987-1989. 889 Jun 64

The Steno hypothesis suggests that albuminuria reflects widespread vascular damage (proliferative retinopathy and severe macroangiopathy) due to a generalized vascular (endothelial) dysfunction. We assessed this concept in NIDDM (non-insulin-dependent diabetic) patients with (13 female/ 39 male, age 60 +/- 7 years, group 1) and without (12 female /41 male, age 61 +/- 7 years, group 2) diabetic nephropathy compared to matched non-diabetic subjects (7 female/15 male, age 58 +/- 8 years, group 3). A 12-lead ECG was recorded and coded blindly using the Minnesota Rating Scale; the World Health Organization cardiovascular questionnaire was used to assess past and present evidence of myocardial infarction, angina pectoris, stroke, and peripheral vascular disease (digital systolic blood pressure determination). The degree of diabetic retinopathy was scored from fundus photography. The following variables were measured: transcapillary escape rate of albumin (initial disappearance of intravenously injected 125I-labelled human serum albumin), plasma concentrations of prorenin (radioimmunoassay) and serum concentrations of von Willebrand factor (enzyme-linked immunoadsorbent assay). Prevalence of ischaemic heart disease (ECG reading) (49/20/5)% and peripheral vascular disease as indicated by reduced systolic blood pressure on big toe (69/30/ 14)% was significantly higher in group 1 vs group 2 (p < 0.01) and in group 2 vs group 3 (p < 0.01), respectively. The prevalence and severity of retinopathy was higher in group 1 vs 2 (p < 0.01). Transcapillary escape rate of albumin (%/h) was elevated in group 1 and 2 as compared to control subjects: 7.9 (4.3-13.7); 7.4 (3.7-16.4) vs 6.0 (3.4-8.7), (p < 0.005), respectively. Plasma prorenin activity (IU/ml) was raised in group 1 and group 2 as compared to group 3: 272 (59-2405); 192 (18-813), and 85 (28-246), p < 0.001, respectively. Serum von Willebrand factor (IU/ ml) was elevated in group 1 as compared to group 2 and 3: 2.07 (0.83-4.34); 1.60 (0.30-2.99) and 1.50 (1.00-2.38), p < 0.001, respectively. Our study demonstrated that NIDDM patients with and without albuminuria had increased transcapillary escape of albumin and raised prorenin activity, whereas only those with albuminuria had increased von Willebrand factor. Patients with NIDDM may have abnormal endothelial function in the absence of albuminuria.
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PMID:Macro-microangiopathy and endothelial dysfunction in NIDDM patients with and without diabetic nephropathy. 896 Aug 47

We cross-sectionally measured plasminogen activator inhibitor-1 (PAI-1) activity, fibrinogen, factor VII (FVII:C) and VIII (FVIII:C) coagulant activity, and von Willebrand factor antigen (VWF:Ag) in 162 traditional horticulturalists older than 40 years from the tropical island of Kitava, Papua New Guinea, where the intake of western food is negligible and where stroke and ischaemic heart disease appear to be absent. Identical analyses were made in Swedish subjects of comparable ages. Kitavams had markedly lower PAI-1 activity, with 85% of males and 100% of females having PAI-1 activity < or = 5 U/ml, as compared with 22 and 14% in Swedish males and females (p < 0.0001). Surprisingly, Kitavans also had higher FVII:C. FVIII:C and VWF:Ag. Fibrinogen was 10% lower in Kitavan males while 25% higher in Kitavan females. The very low PAI-1 activity in Kitavans may explain some of their apparent freedom from cardiovascular disease and probably relates to their extreme leanness.
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PMID:Haemostatic variables in Pacific Islanders apparently free from stroke and ischaemic heart disease--the Kitava Study. 903 56

Two specific endothelial cell products, von Willebrand factor and soluble E-selectin, were measured together with serum lipids, lipoprotein(a), systolic and diastolic blood pressure (SHP, DBP) in a follow up study of 162 patients attending a dedicated lipid clinic. Patients were further classified by the presence or absence of symptomatic vascular disease and smoking. After a mean of 49 months, 45 patients experienced a cardiovascular event (fatal or nonfatal myocardial infarction, stroke, or arterial surgery) and 11 developed non-cardiovascular diseases, including cancer. In univariate analysis, existing vascular disease (P < 0.01), increased levels of von Willebrand factor (P < 0.0001) and low density lipoprotein cholesterol (P < 0.02), greater age (P < 0.01), and lower levels of soluble E-selectin (P < 0.03) were all predictive of future vascular events. However, in multivariate analysis, only increased von Willebrand factor was predictive (P < 0.001). von Willebrand factor was also higher in patients who developed non-cardiovascular disease relative to those free of disease (P < 0.05). Our data support the hypothesis that increased levels of von Willebrand factor are an indicator of poor prognosis in patients with atherosclerosis or its risk factors.
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PMID:von Willebrand factor and soluble E-selectin in the prediction of cardiovascular disease progression in hyperlipidaemia. 924 60

This study examined cross-sectional age relations of blood pressure, anthropometric indexes, serum lipids, and hemostatic variables in 203 subsistence horticulturists aged 20-86 y in Kitava, Trobriand Islands, Papua New Guinea. The population is characterized by extreme leanness (despite food abundance), low blood pressure, low plasma plasminogen activator inhibitor 1 activity, and rarity of cardiovascular disease. Tubers, fruit, fish, and coconut are dietary staples whereas dairy products, refined fat and sugar, cereals, and alcohol are absent and salt intake is low. Although diastolic blood pressure was not associated with age in Kitavans, systolic blood pressure increased linearly after 50 y of age in both sexes. Body mass index decreased with age in both sexes. Serum total cholesterol, triacylglycerol, low-density-lipoprotein cholesterol, and apolipoprotein B increased in males between 20 and 50 y of age, whereas high-density-lipoprotein cholesterol and apolipoprotein A-I decreased. There were no significant differences in these indexes with age in the few females studied. A slight linear age-related increase of lipoprotein(a) was present in males. Plasma fibrinogen, factor VII clotting activity, factor VIII clotting activity, and von Willebrand factor antigen increased with age in both sexes but plasminogen activator inhibitor 1 activity did not. The modest or absent relations between the indexes measured and age are apparently important explanations of the virtual nonexistence of stroke and ischemic heart disease in Kitava.
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PMID:Age relations of cardiovascular risk factors in a traditional Melanesian society: the Kitava Study. 932 59


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