Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042373 (vascular disease)
 17,070 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tenascin-C (TN-C) is induced in pulmonary vascular disease, where it colocalizes with proliferating smooth muscle cells (SMCs) and epidermal growth factor (EGF). Furthermore, cultured SMCs require TN-C for EGF-dependent growth on type I collagen. In this study, we explore the regulation and function of TN-C in SMCs. We show that a matrix metalloproteinase (MMP) inhibitor (GM6001) suppresses SMC TN-C expression on native collagen, whereas denatured collagen promotes TN-C expression in a beta 3 integrin- dependent manner, independent of MMPs. Floating type I collagen gel also suppresses SMC MMP activity and TN-C protein synthesis and induces apoptosis, in the presence of EGF. Addition of exogenous TN-C to SMCs on floating collagen, or to SMCs treated with GM6001, restores the EGF growth response and "rescues" cells from apoptosis. The mechanism by which TN-C facilitates EGF-dependent survival and growth was then investigated. We show that TN-C interactions with alpha v beta 3 integrins modify SMC shape, and EGF- dependent growth. These features are associated with redistribution of filamentous actin to focal adhesion complexes, which colocalize with clusters of EGF-Rs, tyrosine-phosphorylated proteins, and increased activation of EGF-Rs after addition of EGF. Cross-linking SMC beta 3 integrins replicates the effect of TN-C on EGF-R clustering and tyrosine phosphorylation. Together, these studies represent a functional paradigm for ECM-dependent cell survival whereby MMPs upregulate TN-C by generating beta 3 integrin ligands in type I collagen. In turn, alpha v beta 3 interactions with TN-C alter SMC shape and increase EGF-R clustering and EGF-dependent growth. Conversely, suppression of MMPs downregulates TN-C and induces apoptosis.
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PMID:Regulation of tenascin-C, a vascular smooth muscle cell survival factor that interacts with the alpha v beta 3 integrin to promote epidermal growth factor receptor phosphorylation and growth. 931 46

Aspirin is the most extensively studied drug for the prevention of ischemic vascular disease. Meta-analyses confirm that aspirin is effective in prevention of ischemic events, including stroke. Recently, there has been considerable discussion about the best dose of aspirin to prevent stroke. Several studies tested aspirin in a daily dose of 975 mg or more alone or in combination with another drug, most commonly dipyridamole, and noted that aspirin was effective. Successively lower doses of aspirin were tested and recent studies demonstrate that low doses (< 100 mg/day) are effective. Only one study, enrolling patients with transient ischemic attack or minor stroke, has examined aspirin in a daily dose of approximately 325 mg. Side effects of aspirin are dose related; gastrointestinal bleeding and epigastric pain are less with low doses. Available data cannot confirm that low doses (< 100 mg/day) of aspirin are either more or less effective than larger (975 mg/day) doses. A direct comparison of the usefulness of low doses (< 100 mg/day) or large doses (approximately 1,000 mg/day) in patients at high risk of stroke is needed. Until the results of such a study are known, the better safety profile of low doses favors aspirin in a daily dose of 100 mg or less.
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PMID:Low- versus high-dose aspirin in prevention of ischemic stroke. 937 84

Following cerebral ischaemia a recurrent stroke must be avoided in most patients by means of antithrombotic agents. Based on the results reviewed here of new therapy studies, we discuss the presently available antithrombotic treatment options for prophylaxis in ischaemic stroke. TASS (Ticlopidine Aspirin Stroke Study) and CATS (Canadian American Ticlopidine Study) are two multicentre studies investigating the effect of ticlopidine, a new antiplatelet agent of the thienopyridine family, compared to acetylsalicylic acid (ASA) respectively placebo, in the secondary prophylaxis of ischaemic stroke. A significant relative risk reduction of ticlopidine against ASA (21%) and against placebo (28.1%) was shown. CAPRIE (Clopidogrel vs. Aspirin in Patients with Risk of Ischemic Events) evaluated clopidogrel and ASA in the secondary prophylaxe of stroke, myocardial infarction and peripheral vascular occlusive disease. Clopidogrel has been shown to be as effective as ticlopidine compared to ASA in the secondary prevention of vascular disease but had the advantage of a far less severe side effect profile as ticlopidine. ESPS 2 (2nd European Stroke Prevention Study) compared dipyridamole and ASA alone and in combination against placebo in stroke prevention. The combination of agents showed a 24.4% relative risk reduction to suffer ischaemic stroke as opposed to placebo. The ranking of heparin and heparinoids in the secondary prevention of ischaemic stroke has not been completely established but seems to diminish according to recently published data from three major trials. The American TOAST study (Trial of Org 10172 in Acute Stroke Treatment) failed to prove any advantage of intravenous Orgaran compared to placebo. In IST (International Stroke Trial) and CAST (Chinese Acute Stroke Trial) the benefits of heparin are invalidated by a higher bleeding rate of patients on intravenous heparin therapy. Furthermore, the results of IST have to be judged critically because of significant methodical inadequacies. When applying antithrombotic agents, therapeutic effect and presumed better outcome should be weighed against the risk of associated bleedings. The indication for an antithrombotic treatment should be reevaluated in regular control examinations and the possibility of a less aggressive treatment should be considered.
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PMID:[Antithrombotic therapy after cerebral ischemia]. 941 27

The prevention of coronary artery disease is based on the control of several factors associated with a disease or clinical condition and suspected to play a pathogenetic role, defined as 'risk factors'. Smoking is a powerful risk factor for coronary artery disease, with risk of events increasing in relation to the number of cigarettes smoked daily. Smoking cessation is associated within 3-4 years, with a significant reduction in cardiovascular risk. Hyperlipidaemia is a powerful predictor of coronary disease with a strong, independent, continuous and graded positive association between cholesterol levels and risk of coronary events. Several large studies have shown the benefit of cholesterol reduction, and there is clear evidence of the efficacy of statins in the reduction of events in primary and secondary prevention. Hypertension is a significant, strong and independent risk factor for coronary artery disease morbidity and mortality and the reduction of events and mortality by antihypertensive treatment is well documented. Obesity is associated with an increase in all-cause mortality and cardiovascular mortality, with a particularly high risk for subjects with central obesity. Central obesity is also part of the so-called 'metabolic X syndrome' including insulin resistance, which appears to be associated with a particularly high risk of coronary artery disease. Type 1 and type 2 diabetes mellitus are associated with an increased risk of cardiovascular disease, especially in women. Several studies have shown that good metabolic control and multifactorial risk factor reduction significantly lower the coronary risk in these patients. Recent evidence is accumulating that some clotting factors (fibrinogen, factor VII, von Willebrand factor) and fibrinolytic factors (t-PA and PAI-1) are associated with an increased risk of coronary artery disease. The European Concerted Action on Thrombosis (ECAT) showed that the levels of fibrinogen, von Willebrand factor antigen, and t-PA antigen are independent predictors of subsequent coronary syndromes in patients with angina pectoris, and that low fibrinogen is associated with a low risk of events despite high cholesterol levels. Post-menopausal status is associated with increased risk of coronary artery disease, particularly when menopause is premature (before the age of 45) or abrupt (surgical). There is strong, thought not yet completely definite evidence that post-menopausal hormone replacement therapy may significantly reduce the risk of events and improve survival. Hyperhomocysteinaemia is an emerging risk factor independently associated with an increased risk of coronary artery disease, cerebral vascular disease, and peripheral vascular disease. The administration of vitamin B6, B12 or folate seems to be useful and is currently under further evaluation. Recently, attention has been focused on the correlation between coronary artery disease and genetic factors, such as ACE gene polymorphism or the gene polymorphism for the IIIa-moiety of the platelet fibrinogen receptor IIb-IIIa. In primary prevention, control of the major risk factors mainly in patients with clustered factors will substantially reduce the risk of ischaemic events. Secondary prevention of CHD is based on: aggressive behavioural advice, blood pressure reduction in hypertensives, good metabolic control of diabetes, and cholesterol reduction. Aspirin, beta-blockers, ACE inhibitors, and oral anticoagulants, may be useful in selected patients.
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PMID:Classical risk factors and emerging elements in the risk profile for coronary artery disease. 951 44

Arterial thrombosis frequently leads to death or disability from stroke, peripheral arterial disease, or myocardial infarction (MI). Treating the underlying causes of these diseases is the key to producing significant reduction in morbidity, mortality, and health care costs. Prevention of arterial thrombosis is the primary indication for antiplatelet therapy, and intense research has been conducted in the past decade to develop novel antiplatelet agents with favorable safety profiles. The results of the Antiplatelet Trialists' Collaboration, which definitively established the rationale for antiplatelet agents in the prevention of death, MI, and stroke, were an important stimulus for this research. This large meta-analysis combined data from 145 randomized trials and showed that antiplatelet therapy (most commonly aspirin, 75 to 325 mg/d) reduced the risk of vascular events, including nonfatal MI, nonfatal stroke, and vascular death, by 25% in patients at high risk for occlusive vascular disease. The limitations and adverse effects associated with traditional antiplatelet agents such as aspirin have prompted the search for newer antiplatelet agents. Clinical trials such as the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) study, which was the first study to evaluate aspirin and clopidogrel in patients with cerebrovascular, cardiac, and peripheral arterial disease, have established the importance of newer antiplatelet effects in the management of patients with diseases associated with atherosclerosis. The pathophysiology of atherosclerosis, the mechanisms of action of antiplatelet agents, and the results of these and other clinical trials that document the value of antiplatelet agents in atherosclerosis are reviewed in this paper.
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PMID:Antiplatelet therapy in atherosclerotic cardiovascular disease. 958 29

The mechanisms of action of currently available and newer antiplatelet agents and evidence of the efficacy of antiplatelet agents for primary and secondary prevention of coronary artery disease are reviewed. Available data do not support the widespread use of aspirin for primary prevention of cardiovascular disease. Patients over the age of 50 years with at least one additional risk factor for coronary artery disease may benefit, although possibly at an increased risk of hemorrhagic stroke. Aspirin is recommended for secondary prevention of vascular disease in patients with stable or unstable angina, clinical or laboratory evidence of coronary artery disease, history of myocardial infarction, or history of stroke or transient ischemic attack. There are no data supporting a role for dipyridamole for primary or secondary prevention of ischemic heart disease. Abciximab has been shown to reduce the risk of cardiovascular complications at 30 days after percutaneous transluminal coronary angioplasty in patients with refractory unstable angina. Studies with other glycoprotein IIb/IIIa-receptor antagonists, including eptifibatide, tirofiban, and lamifiban, have yielded promising results. Ticlopidine may be used for secondary prevention of cardiovascular disease in patients with unstable angina who are allergic to or intolerant of aspirin. Clopidogrel has been shown to be safe and effective for secondary prevention of vascular events. Aspirin has a role in secondary prevention of coronary artery disease; among patients who are allergic to or intolerant of aspirin, ticlopidine has a role in patients with unstable angina and clopidogrel has a potential role in patients with ischemic heart or vascular disease.
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PMID:Antiplatelet therapy in coronary artery disease: review and update of efficacy studies. 978 97

Antiplatelet drugs have been demonstrated to reduce the incidence of myocardial infarction (MI), stroke or vascular death in patients with vascular disease. There are no data suggesting that antiplatelet therapy acts differently in older people than in younger people and recommendations based on randomised clinical trials are probably generalisable to older people. Aspirin (acetylsalicylic acid) has been shown to reduce the incidence of non-fatal MI, nonfatal stroke and vascular death in patients with acute MI, a previous MI, angina pectoris or peripheral occlusive arterial disease (POAD), and to reduce cardiovascular morbidity and mortality in patients with a prior ischaemic stroke or transient ischaemic attack (TIA). It has also been shown to reduce the incidence of thrombus formation after coronary artery bypass graft surgery and percutaneous transluminal angioplasty, and in patients with atrial fibrillation and heart valve replacements. Deep vein thrombosis and pulmonary embolism after surgery are also prevented by aspirin. The available data allows the following recommendations to be made. Aspirin 160 to 325 mg daily should be administered to older men and women without contraindications to aspirin who have acute MI, prior MI, unstable or stable angina pectoris, ischaemic stroke, TIA or POAD, and continued indefinitely to reduce the risk of MI, stroke or vascular death. Aspirin should be started in patients before or immediately after revascularisation, and after heart valve replacement. Older men and women with nonvalvular atrial fibrillation who have contraindications to oral anticoagulant therapy but no contraindications to aspirin should be treated with aspirin 325 mg daily. It is reasonable to treat older men and women without contraindications to aspirin with aspirin 160 to 325 mg daily if they are at high risk for developing new coronary events. The incidence of stroke, MI or vascular death in patients after a stroke or TIA is reduced by ticlopidine. Therefore, ticlopidine 250 mg twice daily may be used in older men and women with a history of stroke or TIA who do not respond to or who cannot tolerate aspirin. Patients at high risk for coronary artery stent thrombosis benefit from combined therapy with aspirin plus ticlopidine. The annual incidence of ischaemic stroke, MI or vascular death was significantly reduced by clopidogrel in the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial. Therefore, clopidogrel 75 mg daily may be used in older men and women with symptomatic atherosclerosis who do not respond to or who cannot tolerate aspirin to reduce the incidence of ischaemic stroke, MI or vascular death. It should be noted that the acquisition cost for either ticlopidine or clopidogrel is considerably greater than that for aspirin. Most data indicate that the combination of aspirin and dipyridamole is not more effective than aspirin alone in preventing vascular events, and available data do not support the use of sulfinpyrazone in patients with vascular disease.
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PMID:Antiplatelet agents in the prevention of cardiovascular morbidity and mortality in older patients with vascular disease. 1049 69

For the long-term prevention of thromboembolic events in patients with atherosclerotic vascular disease, aspirin is the preferred antiplatelet drug. Only clopidogrel was shown to be more effective and at least as safe than medium-dose aspirin in direct comparative large-scale trials. Aspirin inhibits the cyclooxygenase dependent pathway of platelet aggregation while ticlopidine and clopidogrel selectively bind to adenosine diphosphate (ADP) receptors on the platelet surface. Compounds which inhibit the synthesis of thromboxane synthase, block the thromboxane receptor or have the dual activity were effective in experimental thrombosis models in animals but not predictive of results in humans. Activation of the platelet glycoprotein (GPIIb/IIIa) receptor on the platelet surface is the final pathway of platelet aggregation, regardless of the initiating stimulus. Inhibitors of GPIIb/IIIa receptors include monoclonal antibodies (abciximab) against this receptor and peptidic as well as non-peptidic synthetic specific receptor blockers. Abciximab exchanges between and binds to platelets for as long as two weeks whereas synthetic GPIIb/IIIa inhibitors inhibit ex vivo platelet aggregation for only a few hours after the end of infusion but have the advantage of being also orally active. In the secondary prevention of atherothrombosis, large scale trials were successfully conducted with aspirin, dipyridamole and clopidogrel. In the first large-scale trials with GPIIb/IIIa inhibitors with abciximab was investigated. In aggregate, this class of platelet inhibitors, combined with aspirin and heparin, was shown to reduce ischaemic events in patients with high- and low-risk coronary intervention, stents, unstable angina and non-Q-wave infarction with long-term preservation of the initial benefit. With synthetic GPIIb/IIIa inhibitors there is no suppression of clinical evident restenosis 6 months after the end of treatment. With the doses presently used, bleeding occurs more often with the synthetic GPIIb/IIIa inhibitors (used for 3 days) than with abciximab (used for 12 hours) but there are no direct comparisons between these drugs.
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PMID:8th Seah Cheng Siang Memorial Lecture: new antithrombotic agents. 1057 18

Aspirin (ASA) does not effectively lower platelet aggregation in all people. The platelet aggregation (PA) score is an easily used clinical method for measuring the effect in individuals of antiplatelet medications. Fifteen apparently healthy subjects (2 men and 13 women), selected for their resistance to ASA's antiaggregation effect, completed a sequential trial of ticlopidine, Alka-Seltzer, and ASA + citric acid (CTA). Ticlopidine was the strongest aggregation inhibitor and the ASA + CTA combination was more inhibitory than Alka-Seltzer. It was determined that measuring antiaggregation effects of a particular agent in an individual prior to usage would optimize treatment. The PA score methodology provides a means for testing patients prior to antiplatelet therapy for prevention and treatment of the thrombotic complications of vascular disease.
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PMID:Ticlopidine, Alka-Seltzer, or a combination of citric acid with aspirin: effects on platelet aggregation in individuals with an insufficient response to aspirin alone. 1103 May 28

This study describes the methods of anaesthesia and analgesia used in 349 major lower limb amputations for vascular disease over a seven year period (1992-8). The main type of anaesthesia was general in 55%, spinal in 29%, and epidural in 14%: there were no significant differences for ASA grade, age, or amputation level, nor any statistical differences in mortality for each method of anaesthesia. The main methods of analgesia in the first 48 hours changed between 1992 and 1998, with decreasing intramuscular and oral opioids (from 38% to 7%, and from 23% to 2% respectively) while epidurals became the commonest method (4% in 1992 and 63% in 1998). Thirty seven percent of patients were prescribed carbamazepine for phantom pain. There have been substantial changes in postoperative analgesia following amputation, and epidurals are now common practice, despite the controversy about their role in preventing phantom pain.
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PMID:Anaesthesia and analgesia for major lower limb amputation. 1106 20


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