Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Apolipoprotein E (apoE) is a plasma lipoprotein which plays a basic role in the degradation of particles rich in cholesterol and triglycerides. It is able to bind to LDL receptors, but also to receptors for chylomicron remnants. There are three major apoE isoforms, E2, E3, and E4. Their role in lipoprotein metabolism is related to their affinity for receptors. Allele E3 is predominant and apoE3 affects metabolism of lipoproteins in a standard way. When compared to allele E3, allele E2 is associated with lower LDL levels, whereas allele E4 with higher LDL levels. This has an impact on the progression of atherosclerosis. Allele E2 exhibits a protective role, whereas allele E4 is associated with a high risk factor. Lipoprotein(a) [Lp(a)] is a plasma lipoprotein, consisting of apolipoprotein(a), linked by a covalent bond with the LDL particle. Increased Lp(a) levels are associated with an increased incidence of diseases based on atherosclerosis, namely the ischemic heart disease. Another effect of Lp(a) is its competition with plasminogen, resulting in a decrease of fibrinolysis and thrombogenic activity. ApoE and Lp(a) are independent risk factors for premature development of atherosclerosis and therefore can be considered as candidate genes of premature atherosclerosis.
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PMID:Apolipoproteins and atherosclerosis. Apolipoprotein E and apolipoprotein(a) as candidate genes of premature development of atherosclerosis. 1098 73

Long-term moderate or strenuous physical activity is associated with a considerable reduction in cardiovascular morbidity and mortality in primary and secondary prevention. Various mechanisms, including changes in lipids, lifestyle habits, and other positive physiologic effects, have been suggested to mediate these beneficial effects. In addition, the hemostatic and fibrinolytic systems appear to play an important role. Fibrinogen has been convincingly shown to be an independent cardiovascular risk factor. Other hemostatic and fibrinolytic parameters that are predictive of coronary events include factor VII, platelet hyperreactivity, plasminogen-activator inhibitor 1 (PAI-1), and tissue-plasminogen activator. The effects of exercise on fibrinogen have been intensively studied. Several randomized controlled trials, various other intervention studies and a large number of population-based cross-sectional studies all found an inverse relationship between measures of sport activity or leisure activity and plasma fibrinogen. The magnitude of the effect reported might be associated with a sizeable reduction in major coronary events. Relatively few data are available on the effects of endurance exercise on markers of the fibrinolytic system, with inconsistent results. Acute exercise leads to a transient activation of the coagulation system, which is accompanied by an increase in the fibrinolytic capacity in healthy subjects. Patients with ischemic heart disease, who cannot increase their fibrinolytic potential, however, may be at considerable risk for acute ischemic events if they are exposed to unaccustomed strenuous physical exertion.
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PMID:Exercise and thrombosis. 1157 Jan 12

Platelet activation, impairment of fibrinolysis, activation of the coagulation pathway, and dyslipidemia are important factors in the pathogenesis and progression of ischemic heart disease, and patients generally need to use an antiplatelet agent. Lipid-lowering cerivastatin, a novel 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, was administered to 20 patients with primary mixed hyperlipidemia for the assessment of the effect of cerivastatin on lipid levels, plasma fibrinogen concentration, factor VII, VIII, and X levels, plasminogen and antiplasmin concentrations, platelet count, and aggregation (adenosine diphosphate [ADP], collagen, and epinephrine induced). Assessments were made immediately after 2 months of a standard lipid-lowering diet, 4 weeks of placebo administration, and 4 weeks of cerivastatin treatment. Cerivastatin achieved significant reductions in triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels. The significant improvement of the lipid profile was associated with platelet aggregation reduction in vitro stimulated by ADP, collagen, and epinephrine (P < .05, P = .05, P < .005, respectively). Significantly lower levels of factor VII and fibrinogen were observed (P = .001, P < .0001) immediately after cerivastatin treatment. No significant differences were detected in factor VIII level, plasminogen and antiplasmin concentrations, and platelet count after cerivastatin treatment. It was concluded that cerivastatin in mixed hyperlipidemia can exert beneficial changes on specific hemostatic variables and platelet aggregation in addition to its positive effects on plasma lipid values.
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PMID:Treatment with cerivastatin in primary mixed hyperlipidemia induces changes in platelet aggregation and coagulation system components. 1241 40

Cholesterol lowering therapy markedly reduces the frequency of subsequent cardiovascular events and is associated with a modest degree of angiographic regression of atherosclerotic lesions. There is a strong association between lipids and fibrinogen, plasminogen activator-1, and activated factor VII levels. Low density lipoprotein may be thrombogenic whereas high density lipoprotein protects against thrombosis. Lipoprotein (a) may affect atherosclerosis and thrombosis mainly by binding to fibrin and attenuating the fibrin-enhanced plasminogen activation. Tissue factor-complex initiates coagulation by activating factor X and factor IX leading in the presence of calcium to the generation of thrombin. Lipid lowering treatment with statins stabilizes atheromatous plaque and has antithrombotic effects. Therefore there are links between lipids and the haemostatic mechanisms which affect atherosclerotic, vasomotor and thrombotic components of ischemic heart disease.
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PMID:Effects of lipids on thrombotic mechanisms in atherosclerosis. 1241 62

Levels of fibrinogen, von Willebrand factor, d-dimer, antithrombin III, protein C, plasminogen, and plasminogen activator inhibitor were measured in 62 men and 37 women with ischemic heart disease before and after 20-min venous occlusion. Women compared with men had higher baseline levels of fibrinogen (4.046-/+0.1785 and 3.584-/+0.1591 g/l, respectively, p=0.021), von Willebrand factor (122.1-/+9.31 and 99.5-/+6.16%, respectively, p=0.035), plasminogen activator inhibitor (4.8-/+0.31 and 2.9-/+0.27 IU/l, respectively, p=0.009). Levels of antithrombin III, protein C, and plasminogen in women were higher than in men both at baseline (108.5-/+1.65 and 100.7-/+1.60 %, p=0.001; 129.1-/+2.91 and 107.2-/+3.79%, p=0.001; 113.6-/+2.13 and 104.1-/+1.89%; p=0.001, respectively) and after venous occlusion. There were no gender differences in dynamics of parameters of hemostasis during venous occlusion. Multifactorial regression analysis showed that gender was independently (of age, duration of hypertension, smoking, body mass index, and total cholesterol level) related to only antithrombin III and protein C levels.
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PMID:[Gender differences in the state of the system of hemostasis in patients with ischemic heart disease]. 1249 45

The risk of ischemic heart disease is 2-4 times greater in diabetes, occurs at a younger age, and is much higher in women with diabetes. The risk of coronary disease is increased in patients with poor glycemic control, but studies have not shown a major impact of improved glucose management on cardiovascular mortality. This apparent contradiction may be due to the many potential mechanisms of increased cardiovascular damage in diabetes, including hypertension; abnormal clotting function due to changes in fibrinolysis, platelet adherence, and plasminogen activity; abnormal vascular reactivity; and abnormal lipid patterns and particles. Some, but not all, of these issues are related to lifestyle factors, including diet, exercise, and cigarette smoking. The treatment of hypertension and hypercholesterolemia has been more successful in reducing cardiovascular mortality than reducing HbA1c levels. One of the major, unresolved questions is whether insulin resistance rather than hyperglycemia is the primary risk factor for cardiovascular disease (CVD). Antidiabetic agents that target insulin resistance may be more cardioprotective than those that primarily augment insulin secretion.
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PMID:Advances in diabetes for the millennium: the heart and diabetes. 1564 12

Myocardial ischemia-reperfusion (I/R) is associated with the activation of matrix metalloproteinases (MMPs) and serine proteases. We hypothesized that activation of MMPs and the serine protease plasmin contribute to early cardiac myocyte death following I/R and that broad-spectrum protease inhibition with doxycycline (DOX) preserves myocyte viability. Rats treated daily with or without DOX beginning 48 h prior to experimentation were subjected to 30 min of coronary occlusion and 2 days of reperfusion. DOX pre-treatment reduced infarct size by 37%. DOX attenuated increases in MMP-9 and plasmin levels as determined by gelatin zymography and immunoblot, respectively. Neutrophil extravasation was unaltered by DOX as assessed by myeloperoxidase (MPO) activity. To examine the contribution of MMP-9 and plasmin to myocyte injury, cultures of neonatal rat ventricular myocytes (NRVMs) were treated for 48 h with 83 kDa MMP-9 or plasminogen in the presence or absence of DOX. MMP-9 treatment did not affect myocyte viability. Plasminogen treatment led to increased plasmin activity, resulting in loss of beta1-integrin, NRVM detachment and apoptosis. DOX co-treatment inhibited plasmin activity and preserved NRVM attachment, whereas co-treatment with the broad-spectrum MMP inhibitor GM6001 had no effect. These results indicate that plasmin causes disruption of myocyte attachment and viability independently of MMP activation in vitro and that inhibition of plasmin by DOX may reduce I/R-induced myocyte death in vivo through the inhibition of plasmin.
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PMID:Reduction of myocardial infarct size by doxycycline: a role for plasmin inhibition. 1579 48

There is a considerable body of evidence supporting an association between hypertriglyceridaemia, a hypercoagulable state and atherothrombosis. A disorder of triglyceride metabolism is a key feature of the metabolic syndrome that increases risk of both ischaemic heart disease and type 2 diabetes approximately 3-fold. An increasing prevalence of obesity and metabolic syndrome is likely to contribute markedly to the prevalent ischaemic heart in the foreseeable future, and therefore it is crucial to understand mechanisms linking hypertriglyceridaemia and a hypercoagulable state. Activation of platelets and the coagulation cascade are intertwined. VLDL and remnant lipoprotein concentrations are often increased with the metabolic syndrome. These lipoproteins have the capacity to activate platelets and the coagulation pathway, and to support the assembly of the prothrombinase complex. VLDL also upregulates expression of the plasminogen activator inhibitor-1 gene and plasminogen activator inhibitor-1 antigen and activity, a process accompanied by platelet aggregation and clot formation. The surface membrane of activated platelets also supports the assembly and activity of the prothrombinase complex, resulting in further thrombin generation and amplification of the coagulation cascade. Fibrinolysis is also less efficient when thrombin is generated. Thrombin induces thrombin activatable fibrinolysis inhibitor. Thrombin activatable fibrinolysis inhibitor is a carboxypeptidase that cleaves the carboxylic lysine residues on fibrin, thereby abolishing the critical binding site for tPA-plasminogen decreasing plasmin formation. Thus the evidence is supportive of dysregulated coagulation, and impaired fibrinolysis with a predisposition to atherothrombosis, in conditions such as the metabolic syndrome, in which there are increased concentrations of VLDL and remnant lipoproteins. The purpose of this review is to describe the current evidence supporting a procoagulant state induced by VLDL and remnant lipoproteins. The role of these lipoprotein classes in (1) platelet activation; (2) the intrinsic coagulation cascade, and (3) clot formation and fibrinolysis is discussed.
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PMID:Effects of VLDL and remnant particles on platelets. 1687 77

The aim of this review is to summarize present evidence of a causal association of lipoprotein(a) with risk of ischemic heart disease (IHD). Evidence for causality includes reproducible associations of a proposed risk factor with risk of disease in epidemiological studies, evidence from in vitro and animal studies in support of pathophysiological effects of the risk factor, and preferably evidence from randomized clinical trials documenting reduced morbidity in response to interventions targeting the risk factor. Elevated and in particular extreme lipoprotein(a) levels have in prospective studies repeatedly been associated with increased risk of IHD, although results from early studies are inconsistent. Data from in vitro and animal studies implicate lipoprotein(a), consisting of a low density lipoprotein particle covalently bound to the plasminogen-like glycoprotein apolipoprotein(a), in both atherosclerosis and thrombosis, including accumulation of lipoprotein(a) in atherosclerotic plaques and attenuation of t-PA mediated plasminogen activation. No randomized clinical trial of the effect of lowering lipoprotein(a) levels on IHD prevention has ever been conducted. Lacking evidence from randomized clinical trials, genetic studies, such as Mendelian randomization studies, can also support claims of causality. Levels of lipoprotein(a) are primarily determined by variation in the LPA gene coding for the apolipoprotein(a) moiety of lipoprotein(a), and genetic epidemiologic studies have documented association of LPA copy number variants, influencing levels of lipoprotein(a), with risk of IHD. In conclusion, results from epidemiologic, in vitro, animal, and genetic epidemiologic studies support a causal association of lipoprotein(a) with risk of IHD, while results from randomized clinical trials are presently lacking.
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PMID:Lipoprotein(a) and ischemic heart disease--a causal association? A review. 2010 78

Extract: When we are wounded, either externally (for instance, when we cut ourselves) or internally (for instance, due to gastric ulcer or brain hemorrhage), blood clots -- sponge-like plugs that are rapidly formed in response to the injury by activated blood platelets and fibrin in a process called coagulation -- prevent profound bleeding. Thus, good or hemostatic clots save our lives. However, under pathological conditions blood clots can also form inside vessels. Such bad or thrombotic clots occlude blood vessels and cause oxygen starvation of vital organs including the brain (stroke), heart (acute myocardial infarction) or lungs (pulmonary embolism). Thrombosis is one of the leading causes of morbidity and mortality from cardiovascular and other disease conditions. Diverse anti-thrombotic means are being developed. For instance, anticoagulants (such as heparin) and platelet inhibitors (such as aspirin) help to prevent formation of clots (blood thinners). Fibrinolytics, known as plasminogen activators (such as tissue-type plasminogen activator, or tPA) dissolve formed clots by degrading the fibrin meshwork. Both types of therapeutics are widely used in medical practice, e.g., for treatment of two forms of ischemic heart disease caused by thrombi in coronary vessels -- acute myocardial infarction and unstable angina.
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PMID:Coupling of anti-thrombotic agents to red blood cells offers safer and more effective management of thrombosis. 2070 55


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