Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Coronary artery stenting has definitely been proven to improve results of percutaneous revascularisation in a large number of patients. Stenting reduces restenosis in large vessels above 3 mm diameter. Stenting has not solved the problem of restenosis but in spite of the inevitable in-stent restenosis due to neointimal proliferation seems to yield better long-term results than conventional PTCA. Adjunctive pharmacological treatment with aspirin and clopidogrel in combination with improved stent deployment techniques has reduced the incidence of subacute stent thrombosis. GP IIb/IIIa inhibition is a promising mean for the reduction of procedure related ischaemic events and complications not only with stent implantation but also with conventional PTCA. Other new devices may further influence the treatment choices of stenting versus conventional PTCA in the future. Novel approaches such as brachytherapy and molecular genetic approaches to reduce in-stent restenosis are currently being investigated but to date no conclusions can be drawn as to their future place in clinical practice. From a mechanistic standpoint it seems obvious to give all our efforts to protect patients with coronary atherosclerosis from loss of myocardium either with coronary artery bypass grafting or percutaneous revascularisation. As both approaches are palliative in nature, it may be useful to attempt percutaneous revascularisation in patients amenable to this therapy and thus obviate or delay the need for definitive revascularisation by coronary artery bypass grafting. At the end of this discussion we would like to remind that medical therapy for coronary artery disease is of utmost importance as all revascularisation procedures do not influence the underlying disease. Besides symptomatic relief of angina, treatment of heart failure, and other beneficial strategies to improve endothelial function, medical therapy with lipid lowering compounds together with risk factor control offers the possibility to delay progression of coronary artery disease.
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PMID:To stent or not to stent. 1059 78

Platelets have been shown to play an important role in the pathogenesis of atherosclerosis, acute coronary syndromes, and ischemic complications after percutaneous coronary intervention. Fibrinogen binding via platelet surface glycoprotein (GP) IIb/IIIa receptors constitutes the "final pathway" in platelet aggregation leading to thrombus formation. The GP IIb/IIIa receptor inhibitors, a new class of antiplatelet agents that have emerged in recent years, show great promise in reducing complications of coronary angioplasty and acute coronary syndromes. This review will examine the biology of platelet GP IIb/IIIa receptors, the various classes of GP IIb/IIIa receptor antagonists, the results of the latest clinical trials, and their implications in current clinical practice.
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PMID:Platelet Glycoprotein IIb/IIIa Integrin Blockade in Coronary Artery Disease: Current State of the Art. 1063 48

Platelets play a crucial role in the pathogenesis of atherosclerosis and especially in the final ischemic consequences such as acute coronary syndromes. Furthermore, platelets are central mediators of acute or subacute complications of coronary interventions. Therefore, therapeutic inhibition of platelet function is of major interest in cardiology. The following review describes three different therapeutic strategies for platelet inhibition and provides a representative overview on the clinical results of studies based on these strategies. First, the mechanism of acetylsalicylic acid is described and the strong meta-analytic data demonstrating a convincing positive clinical effect is discussed. Second, the mode of action of the thienopyridines is described and initial clinical results are discussed. Third, the inhibition of the platelet integrin receptor GP IIb/IIIa is described as a potent way to block the final common pathway of platelet stimulation. The structural description of GP IIb/IIIa is followed by a structural classification of the available GP IIb/IIIa inhibitors. Clinical studies, meanwhile including several thousands of patients, are discussed based on representative examples. Finally, unresolved issues regarding the various GP IIb/IIIa inhibitors, such as differences in receptor affinity and specificity, intrinsic activation and GP IIb/IIIa inhibitor induced thrombocytopenia are, discussed.
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PMID:[Therapeutic inhibition of platelets in a acute coronary syndrome and in coronary intervention: mechanisms and clinical results]. 1109 61

Early studies considered that fibrinogen receptor (glycoprotein [GP] IIb-IIIa or platelet integrin alpha(IIb)beta(3)) is the binding site for low-density lipoprotein (LDL) and high-density lipoprotein type 3 (HDL(3)). Recent data, however, do not support the hypothesis that the binding of LDL to human intact resting platelets is related to integrin alpha(IIb)beta(3). In this study we present evidence that platelet integrin alpha(IIb)beta(3) is also not involved in the interaction of HDL(3) and human intact resting platelets. Firstly, specific ligands for platelet integrin alpha(IIb)beta(3), such as fibrinogen, vitronectin, von Willebrand factor and fibronectin, were unable to inhibit the binding of HDL(3) to intact resting platelets. Secondly, the HDL(3) binding characteristics (K(d) and B(max) values), the activation of protein kinase C (PKC) and the inhibition of thrombin-induced inositoltriphosphate (IP(3)) formation and calcium (Ca(2+)) mobilization mediated by HDL(3) particles were similar in platelets from control subjects and patients with type I and type II Glanzmann's thrombasthenia, which are characterized by total and partial lack of GPIIb-IIIa and fibrinogen, respectively. In contrast, nitrosylation of tyrosine residues of HDL(3) by tetranitromethane fully abolished both the ability of particles to interact with its specific binding sites and the functional effects. Thirdly, polyclonal antibodies against the GPIIb-IIIa complex (edu-3 and 5B12), human antiserums against platelet alloantigens (anti-Bak(a/B) and anti-PL(A1/2)), anti-integrin subunits (anti-alpha(V) and anti-beta(3)), and a wide panel of monoclonal antibodies (mAbs) against well-known epitopes of GPIIb (M3, M4, M5, M6, M8 and M95-2b) and GPIIIa (P23-7, P33, P37, P40, and P97) did not affect the binding of HDL(3) particles to human intact resting platelets. Overall results show that neither the GPIIb-IIIa complex nor GPIIb or GPIIIa individually are the membrane binding proteins for HDL(3)on intact resting platelets.
Atherosclerosis 2001 Jan
PMID:Platelet HDL(3) binding sites are not related to integrin alpha(IIb)beta(3) (GPIIb-IIIa). 1113 79

Diabetes mellitus (DM) type 2 is a very strong risk factor for atherosclerosis. The final event of atherosclerosis is the vessels occlusion by platelet riche thrombus. Platelets adhesion and aggregation is mediated by interaction between platelets glycoproteins: GPIb-IX, GPIIb-IIIa and adhesive proteins: von Willebrand factor or fibrinogen. The expression of platelets GPIb-IX, GPIIb-IIIa, plasma vWF, fibrinogen concentrations were evaluated in 40 patients with diabetes type 2 (22 patients with PAOD stage II and IV according to Fontain, 18 diabetics without paod) and 32 healthy individuals. The expression of platelets glycoproteins GPIIb-IIIa and GPIb-IX was estimated by ELISA using monoclonal antibody against GPIIb-IIIa (CD41a) and GPIb-IX (CD 42a Immunotech). Plasma vWf (189.7 +/- 53.6%), fibrinogen (4.5 +/- +/- 1.3 g/l) level and expression of platelets GPIb-IX (63.2 +/- 19.6% in platelets concentration 125,000/mm3, 104.5 +/- 28.1% in platelets concentrations 250,000/mm3) and GPIIb-IIIa 50.8 +/- 10.1% in platelets concentrations 125,000/mm3, 95.3 +/- 21.3% in platelets concentrations 250,000/mm3 were statistically higher in patients with diabetes type 2 than in controls (vWf: 94.9 +/- 27.1%, fibrinogen: 2.8 +/- 0.4 g/l, GPIb-IX in platelets concentration 125,000/mm3: 43.8 +/- 9.3%, in concentration 250,000/mm3: 83.9 +/- 18.3%, GPIIb-IIIa in platelets concentration 125,000/mm3: 33.7 +/- 10.1%, in platelets concentration 250,000/mm3: 63.2 +/- 15.4%). We found significant correlation between the expression of GPIIb-IIIa, GPIb-IIIa, GPIb-IX and plasma adhesive proteins: vWF, fibrinogen in controls and both subgroups of diabetic patients. The correlation between plasma vWF and fibrinogen level and degree of arterial insufficiency in diabetic patients was also found. We can assume that higher vWf, fibrinogen plasma level in diabetic patients with and without PAOD could account for high expression of platelets GPIIb-IIIa and GPIb-IX.
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PMID:[Chronic peripheral arterial occlusive disease, platelet glycoproteins GPIIb-IIIa and GP Ib-IX, plasma von Willebrand factor and plasma fibrinogen concentrations in patients with type 2 diabetes mellitus]. 1123 40

Aspirin inhibits platelet activation by irreversibly inhibiting platelet cyclooxygenase and thromboxane production, and reduces the odds of serious vascular events (stroke, myocardial infarction or vascular death) by about one quarter in a range of patients with symptomatic atherosclerosis at high risk of a subsequent event. The adenosine diphosphate (ADP) receptor antagonists clopidogrel and ticlopidine are significantly more effective than aspirin in high-risk vascular patients, further reducing the odds of serious vascular events by about 10% (95% CI 2-19%) over the benefit provided by aspirin. The ADP receptor antagonists are also associated with a significant 30% reduction in the odds of gastrointestinal haemorrhage (odds ratio 0.71, 95% CI 0.59-0.86). Ticlopidine increases the odds of skin rash and of diarrhoea by more than twofold compared with aspirin, whereas clopidogrel is associated with a one-third increase in the odds of rash and of diarrhoea. Only ticlopidine increases the odds of neutropenia compared with aspirin. There is no clear evidence as yet for the benefit of dipyridamole or an oral GP IIb/IIIa receptor antagonist as single antiplatelet agents in atherothrombotic patients. Amongst high vascular risk patients, the combination of low-dose aspirin and high-dose dipyridamole is associated with about a 10% (95% CI 0-20%) reduction in the odds of a serious vascular event. Most of this reduction is due to a 23% reduction in non-fatal stroke. The size of this estimate continues to be investigated in an ongoing study of patients with transient ischaemic attack and stroke. The combined use of aspirin and ticlopidine is markedly superior to heparin, warfarin and aspirin for reducing thrombotic complications after coronary artery stenting. Clopidogrel plus aspirin has been shown to be safer than aspirin and ticlopidine in coronary stenting, and is now under long-term evaluation in unstable angina, and other conditions in which patients are at high risk of atherothrombotic events.
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PMID:Current oral antiplatelet agents to prevent atherothrombosis. 1131 17

Cardiovascular disease processes such as atherosclerosis, restenosis, and inflammation are typically localized to discrete regions of the vasculature, affording great opportunity for targeted pharmacological treatment. Liposomes are potentially advantageous targeted drug carriers for such intravascular applications. To facilitate their use as drug delivery vehicles, we have considered three components of liposome design: (i) identification of candidate cell surface receptors for targeting; (ii) identification of ligands that maintain binding specificity and affinity; and (iii) prevention of rapid nonspecific clearance of liposomes into the reticuloendothelial organs. In this report, we describe our work in developing liposomal surface modifications that address both targeting and clearance. An arginine-glycine-aspartic acid (RGD) containing peptide was used as a model ligand to target liposomes to the integrin GPIIb-IIIa on activated platelets. Additionally, oligodextran surfactants incorporated into liposomes provided insight into the effect of vesicle perturbations on liposome clearance, and the importance of molecular geometry in designing oligosaccharide surface modifications. Together these studies demonstrate the feasibility of using peptides to guide liposomes to desired receptors, and illustrate the influence of vesicle stability on liposome interactions in vivo. Furthermore, they underscore the importance of simultaneously considering both targeting specificity and vesicle longevity in the design of effective targeted drug delivery systems.
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PMID:Surface modification of liposomes for selective cell targeting in cardiovascular drug delivery. 1177 64

We reviewed recent clinical data on the management of unstable angina and non-ST segment elevation myocardial infarction. We concentrated on the use of new therapies, particularly in combination with both older agents and other new methods, in order to present health care providers with an overview of available treatment options. The clinical trials reviewed herein provide strong evidence and proof of principle that combination therapies targeting 1) platelet function (aspirin, thienopyridines, and GP IIb/IIIa antagonists), 2) the coagulation cascade (unfractionated heparin and low-molecular-weight heparin), and 3) the physical characteristics of the active lesion (percutaneous intervention) reduce the risk of death or ischemic complications after thrombotic progression of coronary atherosclerosis.
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PMID:Unstable angina and non-ST-segment elevation myocardial infarction: perspectives on combination therapy. 1177 52

Structural changes in blood vessels associated with atherosclerosis are at the onset of arterial thrombosis. Thrombi form at the sites of plaque rupture. Plateletrich masses accumulate in the vessel lumen perturb blood flow, thereby aggravating ischemic syndromes. Other local modifications include the recruitment of cells with inflammatory and immunologic potential, showing how complicated this process is. The demonstration that aspirin lowered the number of thrombotic events was an important step in proving the value of anti-platelet therapy. Since then, newer strategies involving drugs acting on the fibrinogen receptor (the GPIIb-IIIa complex) or on ADP receptors have evolved largely as a result of the increased knowledge of the biological pathways of platelet aggregation. These drugs have given superior results in many international trials and their usefulness in interventional cardiology has been proven. Such encouraging progress also incites efforts to find new and improved targets for anti-platelet therapy as well as testing new associations of existing anti-platelet drugs which may also be used with anticoagulant therapies, and in the future, be combined with drugs directly preventing restenosis.
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PMID:[From the physiopathology of thrombosis to therapeutic targets]. 1179 61

Cardiac enzyme elevation is observed in 5-30% of patients after percutaneous intervention and appears associated with higher subsequent cardiac events and mortality. The cause of myocardial enzyme release could be an obvious angiographic complication of the procedure but, most frequently, is neither clinically nor angiographically clear. Different clinical series have identified clinical, angiographic and procedural risk factors for CK-MB elevation after otherwise successful coronary intervention, including unstable angina, diffuse atherosclerosis and aggressive procedures such as atheroablation. Microembolization of atherothrombotic plaque material appears to be the pathogenetic mechanism. Periprocedural administration of platelet glycoprotein IIb/IIIa inhibitors has been shown to reduce subsequent myocardial infarction and long-term mortality. Beta-blockers may also have a protective effect against post-procedural CK-MB elevations and follow-up cardiac events. New distal protection devices are under investigation and appear promising. The risk of inducing myocardial damage during percutaneous intervention should be considered before attempting the procedure. The use of platelet IIb/IIIa inhibitors and protection devices should be considered in high-risk patients.
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PMID:[Predictive elements and prevention of myocardial damage during angioplasty/stenting]. 1204 Aug 43


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