Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

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

Stroke is the second most common cause of death in developed countries. Carotid plaque disruption and distal embolization of atheromatous debris are the most common pathogenic mechanisms for cerebral ischemia from carotid atherosclerotic disease. Morphologic composition of the atherosclerotic plaque, rather than the stenotic severity, appears to be central in determining the risk of both plaque rupture and subsequent thrombosis. Histologic features of vulnerable plaques include a large lipid core, a thin fibrous cap, intraplaque hemorrhage, and an increased number of inflammatory cells, mostly monocyte-macrophages. Due to the catastrophic implications of thrombus formation and embolization on the arterial plaque, detection before major neurologic events occur is now a major goal of cardiovascular clinicians and researchers. New detection imaging techniques such as intravascular thermography, optical coherence tomography, photonic spectroscopy, and elastography have been developed in order to document atherosclerotic lesion composition. This review will focus on the new possibilities under investigation for vulnerable atherosclerotic carotid plaque detection by means of the serologic markers of plaque instability. New markers, such as pregnancy-associated protein A, P-selectin, interleukin-6 and interleukin-12, metalloproteinases, lipoprotein(a), and oxidation products have been reviewed. Most of the promising serologic markers in this article are still in a nascent phase of development and remain to be validated in clinical settings. However, these biohumoral markers, and their potential combination of techniques, may hold promise for the future characterization of the vulnerable plaque and moreover of the vulnerable patient.
...
PMID:[Unstable carotid plaque: biochemical and cellular marker of vulnerability]. 1284 77

Although hypercholesterolemia is widely accepted as a major risk factor for coronary artery and peripheral vascular diseases, its role in the pathogenesis of stroke is controversial. The objectives of this study were to determine how hypercholesterolemia affects the cerebral microcirculation under resting conditions and after ischemia-reperfusion (I/R). Platelet- and leukocyte-endothelial cell interactions and oxidant production (using the oxidant-sensitive fluorochrome dihydrorhodamine-123) were monitored by intravital videomicroscopy in the cerebral microvasculature of mice placed on either a normal (ND) or cholesterol-enriched diet (HCD). Platelets labeled with carboxyfluorescein diacetate succinimidyl ester (CFDASE) and leukocytes labeled with rhodamine 6G were seen to roll and firmly adhere, with a corresponding increase in oxidant production, in venules of mice on HCD, but not ND. Immunoneutralization of P-selectin attenuated the platelet- and leukocyte-endothelial cell interactions and the enhanced oxidant production associated with HCD. A GPIIb/IIIa blocking antibody did not alter the blood cell-vessel wall interactions to HCD. Mice deficient in the NADPH oxidase subunit gp91(phox) exhibited significantly blunted platelet and leukocyte recruitment responses to HCD. Focal I/R also elicited inflammatory and prothrombogenic responses in cerebral venules and these were exaggerated in mice on HCD. These results implicate an oxidant-dependent, P-selectin-mediated mechanism in the blood cell-vessel wall interactions induced by hypercholesterolemia in the brain and demonstrate that the deleterious effects of I/R on the brain are exacerbated by this cardiovascular risk factor.
...
PMID:Cerebral microvascular responses to hypercholesterolemia: roles of NADPH oxidase and P-selectin. 1467 Aug 46

Candidate gene polymorphisms related to inflammation, thrombosis and lipid metabolism have been implicated in the development of ischemic stroke. Using DNA samples collected at baseline in a prospective cohort of 14 916 initially healthy American men, we genotyped 92 polymorphisms from 56 candidate genes among 319 individuals who subsequently developed ischemic stroke and among 2092 individuals who remained free of reported cardiovascular disease over a mean follow-up period of 13.2 years to prospectively determine whether candidate gene polymorphisms contribute to stroke risk. After adjustment for multiple comparisons and age, smoking, body mass index, hypertension, hyperlipidemia and diabetes, two related to inflammation [a val640leu polymorphism in the P-selectin gene (OR=1.63, 95% CI 1.22-2.17, P=0.001) and a C582T polymorphism in the interleukin-4 gene (OR=1.40, 95% CI 1.13-1.73, P=0.003)] were found to be independent predictors of thrombo-embolic stroke. In bootstrap replications, the inclusion of genetic information from these two polymorphisms improved prediction models for stroke based upon traditional risk factors alone (ROC 0.67 versus 0.64). Two polymorphisms related to thrombosis (an arg353gln polymorphism in the factor VII gene and a T11053G polymorphism in the plasminogen activator inhibitor type-1 gene) and one related to lipid metabolism [a C(-482)T polymorphism in the apolipoprotein CIII gene] achieved nominal significance, but were not found to be independent predictors after multiple comparison adjustment. Two inflammatory candidate gene polymorphisms were identified which were independently associated with incident stroke. These population-based data demonstrate the ability of prospective, epidemiological studies to test candidate gene associations for athero-thrombotic disease.
...
PMID:Polymorphism in the P-selectin and interleukin-4 genes as determinants of stroke: a population-based, prospective genetic analysis. 1468 4

Stroke and stroke-like episodes are frequent complications in mitochondriopathy, particularly in MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke like episodes) which is a disorder of the mitochondrial oxidative metabolism in diverse cell types. To clarify a possible pathological aspect of stroke in these patients, we investigated platelet function before and after physical exercise. Ten patients with mitochondriopathy and stroke and ten healthy sex and age matched controls were investigated in an analyst blinded, prospective cross-sectional trial. Exercise decreased intraplatelet adenosine triphosphate (ATP) concentrations by -22% from baseline in patients with mitochondriopathy (p<0.01 between groups) while exercise increased ATP-levels by 28% healthy controls (p=0.01 vs baseline). Thrombin receptor activating peptide (TRAP) stimulated P-selectin expression increased up to 50% (p<0.05) in healthy subjects following exercise compared to 39% (p>0.05) in patients with mitochondriopathy. Exercise trendwise decreased platelet plug formation under shear stress by 24% in patients as measured by the platelet function analyzer PFA-100(R). Tromboelastography showed firm thrombus formation and delayed lysis in patients following exercise. In conclusion, this trial has shown that ATP depletion during and after exercise probably accounts for a defective oxidative metabolism in platelets of patients with mitochondriopathy and stroke. This might induce decreased platelet function in these patients but fails to explain the increased stroke rate. Therefore other mechanisms seem to be etiologically involved in the pathogenesis of stroke in patients with mitochondriopathy.
...
PMID:Platelet function in mitochondriopathy with stroke and stroke-like episodes. 1498 31

Platelet activation is involved in the pathogenesis of atherosclerosis and venous thromboembolism, and might therefore be a possible link between the two entities. Prolactin and leptin have recently been recognized as potent co-activators of ADP-dependent platelet aggregation or P-selectin expression, and are therefore suspected as additional risk factors for both arterial and venous thrombosis. There are clinical situations that have a known association with higher prolactin or leptin levels (pregnancy, obesity or anti-psychotic therapy) and increased risk of thromboembolic events. We compared the impact of both hormones on platelet activation in vitro and in vivo, indicating that prolactin has a stronger effect on platelet activation as leptin in vitro and in vivo. We have also demonstrated that prolactin levels are increased in so called idiopathic thrombosis, and that conversely, patients with prolactinoma have an increased frequency of thrombosis during the hyperprolactinemic state, in a retrospective analysis. Moreover, we have demonstrated increased prolactin values in stroke and myocardial infarction. Prospective studies have yet to be performed to give this theory its final confirmation. The involvement of hormonal factors in platelet aggregation and venous or arterial thrombosis may have important clinical implications such as for risk stratification of patients with venous and arterial thrombosis or new therapeutic options such as decreasing pro-coagulant hormone levels in certain risk situations.
...
PMID:Co-activation of platelets by prolactin or leptin--pathophysiological findings and clinical implications. 1498 99

Platelet activation is an important process in the pathogenesis of atherothrombosis. However, the serial changes of platelet activation in atherosclerotic ischemic stroke have not been determined. In this study, we measured serially platelet expression of CD63 and P-selectin and platelet aggregability to ADP and collagen. Measurements were made 24 and 72 h and 7 and 90 days after the ischemic event in 29 patients with atherosclerotic ischemic stroke. Platelet aggregability was significantly decreased after 72 h compared to that at 24 h of stroke onset. However, platelet CD63 and P-selectin expression remained high even 90 days after the events. These findings suggest that platelet hyperactivation in atherosclerotic ischemic stroke may be sustained for a considerable period.
...
PMID:Increased platelet CD63 and P-selectin expression persist in atherosclerotic ischemic stroke. 1498 70

In the biology of complex disorders, such as atherothrombosis, interactions among genetic factors may play an important role, and theoretical considerations suggest that gene-gene interactions are quite common in such diseases. We used a nested case-control sample from the Physicians' Health Study, a randomized trial assessing the effects of aspirin and beta-carotene on cardiovascular disease and cancer among 22071 US male physicians, to examine these relationships for ischemic stroke. Data were available on 92 polymorphisms from 56 candidate genes related to inflammation, thrombosis and lipid metabolism, assessed in 319 incident cases of ischemic stroke and 2090 disease-free controls. We used classification and regression trees (CART) and multivariate adaptive regression spline (MARS) models to explore the presence of genetic interactions in these data. These models offer advantages over typical logistic regression methods in that they may uncover interactions among genes that do not exhibit strong marginal effects. Final models were selected using either the Bayes Information Criterion or cross-validation. Model fit was assessed using 10-fold cross-validation of the entire selection process. Both the CART and two-way MARS-logit models identified an interaction between two polymorphisms linked to inflammation, the P-selectin (val640leu) and interleukin-4 (C(582) T) genes. Internal validation of these models, however, suggested that effects of these polymorphisms are additive. Although further external validation of these models is necessary, these methods may be valuable in exploring and identifying potential gene-gene as well as gene-environment interactions in association studies.
...
PMID:Tree and spline based association analysis of gene-gene interaction models for ischemic stroke. 1511 52

Atrial fibrillation (AF) is a major cause of morbidity and mortality from stroke due to thromboembolism from the fibrillating left atrium, including its appendage. We hypothesized that indexes of inflammation (as indicated by C-reactive protein and interleukin-6) and indexes of the prothrombotic state in AF that represent platelet activation (soluble P-selectin levels), endothelial damage or dysfunction (von Willebrand factor), coagulation (tissue factor and fibrinogen), and hemorrheology (plasma viscosity and hematocrit) would be related to the presence of thromboembolic predictors on transesophageal echocardiography in patients with long-term AF. To test this hypothesis, we recruited 37 patients with long-term AF who were receiving warfarin therapy with an international normalized ratio of > or =2.0 for > or =3 weeks before transesophageal echocardiography. Twenty-two patients had dense spontaneous echo contrast (SEC) visible in the left atrium or left atrial appendage, 10 had complex atheromatous plaque in the descending aorta, 11 had peak left atrial appendage velocities < or =0.2 m/s, and 3 had thrombus visible in the left atrial appendage. Twenty-eight patients had > or =1 transesophageal echocardiographic (TEE) risk factor for thromboembolism. Plasma levels of C-reactive protein (p = 0.03) and soluble P-selectin (p = 0.04) and hematocrit (p = 0.004) were higher among patients with AF with dense SEC than among those without. No significant associations were found for other TEE risk factors. Hematocrit was the only variable significantly associated with the presence of > or =1 TEE risk factor among patients with AF (p = 0.007) and the only independent associate of dense SEC after multivariate analysis (relative risk 1.4, 95% confidence interval 1.1 to 1.6) per 1% increase in hematocrit (p = 0.003, r(2) = 0.22). Although hematocrit was the only independent associate of dense SEC and > or =1 TEE risk factor, significant associations between dense SEC and the 2 indexes, C-reactive protein and soluble P-selectin, may indicate that mechanisms other than stasis are present with dense SEC. These observations support an "inflammatory hypothesis" in the pathogenesis of SEC that may have implications for thrombogenesis in AF.
...
PMID:Relation of interleukin-6, C-reactive protein, and the prothrombotic state to transesophageal echocardiographic findings in atrial fibrillation. 1516 16

Flow cytometric studies suggest that platelets are activated in ischaemic stroke or transient ischaemic attack (TIA). However, few studies have measured circulating leucocyte-platelet complexes in this patient population. Whole blood flow cytometry was used to quantify the expression of CD62P-, CD63-, and PAC1-binding, and the percentages of leucocyte-platelet complexes in acute (1-27 d, n = 79) and convalescent (79-725 d, n = 70) ischaemic cerebrovascular disease (CVD) patients compared with controls without CVD (n = 27). We performed a full blood count, and measured plasma levels of soluble P-selectin, soluble E-selectin, and von Willebrand factor antigen (VWF:Ag) as additional markers of platelet and/or endothelial cell activation. The median percentage CD62P expression and the median percentage monocyte-platelet complexes were higher in both acute and convalescent CVD patients than controls (P </= 0.02). The mean white cell count and mean VWF:Ag levels were significantly elevated in the acute and convalescent phases after ischaemic stroke or TIA (P </= 0.02). Otherwise, there was no significant increase in any other marker of platelet or endothelial activation in CVD patients. There was a positive correlation between the percentage expression of CD62P and the percentages of both neutrophil-platelet and monocyte-platelet complexes in the acute phase, and the percentages of all leucocyte-platelet complexes in the convalescent phase after ischaemic CVD. This study provides evidence for ongoing excessive platelet and/or endothelial activation in ischaemic CVD patients despite treatment with antithrombotic therapy.
...
PMID:Platelet degranulation and monocyte-platelet complex formation are increased in the acute and convalescent phases after ischaemic stroke or transient ischaemic attack. 1518 Aug 68

Activated platelets are key components in many arterial disorders. P-selectin is an activation-dependent platelet receptor, which is also identified in endothelial cells. Together with E- and L-selectin it constitutes the selectin family. These transmembrane proteins have continued to attract great interest as they support rapid and reversible cell adhesion in flow systems and thus play an essential role in multicellular interactions during thrombosis and inflammation. Similarly to other lectins, selectins bind to different glycoconjugates with varying affinities. Protein ligands, equipped with the appropriate carbohydrate and sulfate moieties for P-selectin binding, have been identified in normal peripheral blood leukocytes and several non-hematopoietic organs, as well as on cancer cells. For diagnostic purposes, P-selectin can readily be detected on the platelet surface by flow cytometry and by ELISA as a soluble ligand in the plasma. Along with other markers, these data can be used in the assessment of platelet activation status. Such results bear clinical significance since P-selectin has been implicated in the pathogenesis of wide-spread disorders including coronary artery disease, stroke, diabetes and malignancy.
...
PMID:The emerging value of P-selectin as a disease marker. 1520 82


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---