Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002962 (angina)
 21,142 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Platelet aggregability was measured using platelet rich plasma (PRP) collected from 197 clinical cases including 52 healthy volunteers. In 31 patients of acute stage of thrombosis (within 2 weeks from the onset), a significant enhancement of platelet aggregation measured 5 min after an addition of 3 and 10 muM ADP or 0.1 and 1 mug/ml of adrenaline to PRP (p less than 0.05, compared to the healthy group). Also a significant enhancement of secondary aggregation induced by adrenaline was observed (p less than 0.05). The enhancement was especially marked in the response induced by adrenaline. Such an enhancement was not observed in patients in the recovery stage of thrombosis, hypertension, angina pectoris and other miscellaneous diseases. There was no difference in the parameters related to the velocity of aggregation or intensity of primary aggregation between the diseased and the healthy group. In response induced by collagen (bovine achilles tendon, 0.3 and 1 mg/ml) any difference in the aggregation curve was not observed between the diseased and the healthy group. Such findings suggest a presence of an enhancement of ADP-release mechanism of platelets in acute thrombosis. Aslo a significance of adrenaline-induced platelet aggregation was proposed to detect platelet functions for analysis of mechanism of thromboembolic disorders.
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PMID:Hyperaggregability of platelets in thromboembolic disorders. 24 93

Suspecting that platelet thromboemboli could play a role in the pathogenesis of myocardial ischemia, we did a random-order, double-blind, crossover study of the effect of the platelet aggregation inhibitor, aspirin, on treadmill exercise-induced angina in 13 men with coronary artery disease. Although collagen-induced platelet aggregation and the second phase of adenosine diphosphate (ADP)-induced platelet aggregation were significantly decreased and the rate of disaggregation of ADP-induced platelet aggregates was significantly increased after 650 mg aspirin in buffered solution, there was no delay in onset of exercise-induced angina, change in heart rate-blood pressure product at onset of angina, or change in S-T segment depression at onset of angina. Regardless of whether the patients had received placebo or aspirin on the preceding day, treadmill exercise until angina was followed by no changes in platelet aggregation or disaggregation, platelet count in blood or platelet-rich plasma, or of the plasma concentration of nonesterified fatty acids.
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PMID:Effect of aspirin on exercise-induced angina. 34 92

Two patients who had previously experienced old myocardial infarction and who died suddenly after an attack of chest pain were examined and discussed. In both cases two of the three main coronary arteries showed severe stenosis with canalization. Ruptured atheromatous plaque was found in the unblocked coronary artery. Fibrin was already formed and surrounded the fractured intimal collagen fiber, foam cells, and cholesterin clefts, but a luminal thrombi had not yet been formed. Fresh occluding thrombi were formed at the site of the ruptured atheromatous plaque. Coronary thrombi containing abscess components such as foam cells, cholesterin clefts, and the fractured intimal collagen fiber were found in our preliminary study. These views support the supposition that this fracture between the lumen and the plaque might precede and be responsible for the formation of the thrombus and the onset of acute myocardial infarction. It was confirmed that the attack of preinfarction angina occurred at the time of the rupture of the atheromatous plaque. The rupture of the atheromatous plaque plays an important part as an initiating factor of peinfarction angina and myocardial infarction. Thus, it is necessary to examine coronary arteries by serial histopathological section method.
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PMID:Relationship between myocardial infarction and preinfarction angina: a histopathological study of coronary arteries in two sudden death cases employing serial section. 61 94

Platelet hypersensitivity has been documented in diabetes and angina pectoris and can be partially reversed in hyperbetalipoproteinemia by clofibrate. We therefore examined the effects of incubating another lipid-lowering agent, halofenate, with both normal platelets and platelets made hypersensitive in vitro by incorporation of 55 per cent excess cholesterol into their membranes. At therapeutic concentrations, halofenate caused a time- and dose-dependent inhibition of the aggregation of normal platelets by epinephrine. After 30 minutes' incubation at 37 degrees C., halofenate significantly inhibited the extent of aggregation by 88 per cent (p less than 0.01), whereas clofibrate inhibited aggregation by 44 per cent (p less than 0.01). Halofenate was a more potent inhibitor of platelets than clofibrate (p less than 0.01). The mean threshold concentration of epinephrine necessary for aggregation of normal platelets (4.2 muM) was not significatnly increased with clofibrate (10 muM) but was markedly elevated with halofenate (245 muM; p less than 0.001). Significant but less dramatic increases in threshold concentration of ADP and collagen were found with halofenate but no clofibrate. Cholesterol-rich platelets were 114-fold more sensitive to epinephrine and twofold more sensitive to ADP than normal platelets but after incubation with halofenate became even less sensitive than normal. Clofibrate inhibited the extent of aggregation of hypersensitive platelets but did not alter the threshold concentration of epinephrine necessary for aggregation. Thus, halofenate is more potent than clofibrate in reducing the sensitivity of normal platelets to aggregating agents in vitro and can completely reverse experimentally produced platelet hypersensitivity. These data suggest that halofenate might be useful in reversing increased platelet sensitivity in cardiovascular diseases.
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PMID:Halofenate: a potent inhibitor of normal and hypersensitive platelets. 95 86

The existence of specific, age-related changes in gastrointestinal motility with clinical significance is controversial. Beside the more infrequent primary motility disorders, secondary motility disturbances associated with collagen vascular diseases, endocrinopathies, and neuromuscular diseases are prominent in the older and often multimorbid patients. Especially in geriatric patients, motility associated symptoms are undesired side-effects of drug therapy. The pathophysiology, clinical syndromes, and therapeutic principles of motility disorders in the elderly are discussed. The major symptoms of esophageal dysfunction are dysphagia, chest pain, heartburn, and regurgitation. Oropharyngeal dysphagia, mostly caused by cerebrovascular accidents and other neurologic disorders, leads to disturbances in food intake, and is often complicated by broncho-pulmonary infections arising from recurrent aspiration of food or saliva. Gastrointestinal reflux disease and spastic motility disorders of the esophagus are regarded as possible causes of angina-like chest pain after exclusion of cardiac diseases. Motility disturbances of the stomach and small bowel are often related to systemic disease (i.e., diabetes mellitus, chronic intestinal pseudo-obstruction) of drug side-effects. Mental and physical decline, reduced fluid intake, and constipating drugs are the most relevant factors for idiopathic constipation in the elderly. Fecal incontinence means a great psychological strain for older patients and leads to social isolation.
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PMID:[Gastrointestinal motility in the elderly]. 144 9

We tested whether alteration of platelet sensitivity to prostacyclin (PGI2) is involved in the activation of platelets induced by exercise in patients with stable angina. Twenty patients and 20 control subjects underwent treadmill testing. Blood samples were obtained before and immediately after exercise for plasma thromboxane B2 (TXB2) and 6-keto-PGF1 alpha (6kP) assays and platelet aggregation studies. Dose-response curves for platelet aggregation to collagen were obtained in the presence and absence of 1 nmol/L PGI2 to quantify the antiaggregation effects of PGI2. At rest, platelet aggregation by collagen was enhanced in the patients. However, platelets were more sensitive to exogenous PGI2, apparently associated with lower plasma 6kP levels in the patients. After exercise, plasma TXB2 levels increased in the patients but not in the control subjects. Plasma 6kP levels remained unchanged and platelet sensitivity to PGI2 decreased in the patients whereas these values increased in the control subjects. The exercise-induced changes in platelet sensitivity to PGI2 correlated with those of platelet adenylate cyclase activity in response to 1 nmol/L PGI2 (r = 0.787, p less than 0.01). Thus impaired sensitivity of platelets to PGI2, in addition to the reduced response of prostanoid secretion, might be relevant to the platelet activation associated with exercise in patients with stable angina.
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PMID:Inhibition of platelet aggregation by prostacyclin is attenuated after exercise in patients with angina pectoris. 173 62

Most ischemic heart disease in associated with severe coronary atherosclerosis. A small subset of patients, however, had angina pectoris despite angiographically normal coronary arteries and absence of inducible coronary spasm. Coronary microcirculation (i.e. arteries too small to be visualized by current angiographic techniques) has been identified as the weak point of these patients. Small coronary vessel involvement may be due to organic conditions (such as diabetes, vasculitis, systemic collagen-vascular diseases, infectious processes) that act through coronary thrombosis or embolism and related alteration in coronary vasomotion; alternatively, the vascular abnormality appears to be entirely functional (no ultrastructural myocardial changes) such as the case of hypertension, hypertrophic cardiomyopathy and syndrome X. Whatever the cause(s) and mechanism(s) of the small coronary artery involvement, this leads to myocardial ischemia and to the related complications as in classic atherosclerotic heart disease. Syndrome X is characterized by effort-induced angina pectoris, ST-segment changes during exercise testing, negative ergonovine test and reduced coronary reserve. A pre-arteriolar hypersensitivity to vasoconstrictor influences (elicited by cold pressor test or ergonovine) and a reduced vasodilator capacity (unmasked by metabolic and pharmacological studies) have been proposed as potential pathogenetic substrate. This dynamic alteration in vasomotion would answer for both symptoms and signs of myocardial ischemia, that, however, appear to be contemporarily elicitable in a minority of patients. Treatment with beta-blockers and calcium-antagonists has been found to be effective. The long-term follow-up shows favorable outcome with a high survival rate and a low incidence of cardiovascular events.
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PMID:[Angina due to microvascular pathology]. 184 63

We investigated incidence, severity, and distribution of coronary atherosclerosis, acute thrombosis, and plaque fissuring in ischemic heart disease (both unstable-acute syndromes and chronic ischemia) and in nonischemic controls. We also studied the structural, immunohistochemical, and biochemical profile of plaques, with and without thrombus, including morphometry, immunophenotyping of inflammatory infiltrates, cytokine presence, and ultrastructural features. Critical coronary stenosis was almost the rule in both acute and chronic ischemic series (greater than 90%) whereas it reached 50% in control subjects. Thrombosis was principally characteristic of unstable-acute ischemic syndromes (unstable angina, 32%; acute myocardial infarction, 52%; cardiac sudden death, 26%) but was also found in chronic ischemia (stable angina, 12%; ischemic cardiomyopathy, 14%) and in control subjects (4%). Plaque fissuring without thrombus occurred in low percentages in lipid-rich, severe eccentric plaques in most series. Major differences were found between pultaceous-rich versus fibrous plaques rather than between plaques with or without thrombus. Pultaceous-rich plaques were frequent in sites of critical stenosis, thrombosis, and ulceration. Inflammatory infiltrates, i.e., T cells, macrophages, and a few beta cells, mostly occurred in lipid-rich, plaques unrelated to thrombus. In adventitia, infiltrates were a common finding unrelated to any syndrome. Necrotizing cytokines such as alpha-TNF were immunohistochemically detected in macrophages, smooth muscle, and intimal cells and detected by immunoblotting in 67% of pultaceous-rich plaques, either with or without thrombus. Immune response mediators such as IL-2 were also expressed in analogous plaques but in a minor percentage (50%-40%). Media were extensively damaged in severely diseased vessels with and without thrombus. Ultrastructural study showed that the fibrous cap was either highly cellular or densely fibrillar. Intimal injury with collagen exposure was often associated with platelet adhesion, whereas foamy cell exposure was not. In conclusion, investigated parameters were essentially similar in plaques, both with and without thrombus, whereas major differences were found between pultaceous-rich and fibrous plaques. Since platelets adhere to exposed collagen and not to foam cells, the type of exposed substrates could play a major role in thrombosis.
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PMID:Coronary atherosclerotic plaques with and without thrombus in ischemic heart syndromes: a morphologic, immunohistochemical, and biochemical study. 189 66

The Caerphilly Collaborative Heart Disease Study is based on a large cohort of men (2,398) aged 49-66 years at the time of study. Platelet aggregation induced by collagen, thrombin, and ADP was measured in fasting blood samples and was related to prevalent angina, past myocardial infarction, and electrocardiographic evidence of ischemic heart disease. A number of subjects had taken aspirin, other nonsteroidal anti-inflammatory drugs, or other drugs affecting platelet aggregation 7 days before blood sample collection; after the exclusion of these subjects, data were available for 1,811 men. No relations were demonstrated with angina, but significant relations were shown between past myocardial infarctions and electrocardiographic evidence of ischemia and ADP-induced aggregation (both primary and secondary) and between electrocardiographic evidence of ischemia and thrombin-induced aggregation. The strongest relation indicated more than a twofold increase in the odds of a past myocardial infarction in subjects of the highest fifth of ADP-induced primary platelet aggregation compared with the lowest fifth. No significant relations were detected with collagen-induced aggregation. Accounting for a number of possible confounding factors had a relatively small impact on the relations between platelet aggregation and ischemic heart disease. Other evidence, including the well-established effect of aspirin on reducing the incidence of ischemic heart disease, indicates that the relations we describe are unlikely to be simply an effect of IHD on platelets.
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PMID:Ischemic heart disease and platelet aggregation. The Caerphilly Collaborative Heart Disease Study. 198 96

Platelet adhesive activity was assayed in patients with stable angina (SA) or unstable angina (UA) and acute myocardial infarction (AMI). With scanning electron microscopy, platelet adhesions to Type IV collagen (C-IV) and plastic material, which had been stimulated by low-dose ADP, epinephrine and U-46 619, a stable thromboxane A2 analogue (agonist-induced adhesion) were determined. As compared with the control group, patients with SA or UA, showed significantly higher adhesion of platelets to the collagen substrate, whereas UA patients alone displayed a significantly increased agonist-induced adhesion when epinephrine was employed as an agonist. A sharp enhancement of platelet adhesion was characteristic of patients with AMI on days 1-3 of the onset. On days 4-5, the adhesive activity slightly dropped, and on day 7-10, it returned to the control level of healthy volunteers. The time course of adhesive activity decrease correlated with lower blood levels of creatine phosphokinase in patients with AMI. A high correlation was established between the alterations found in all the types of platelet adhesion during the course of AMI, which suggests there is an unspecific nature of increase and subsequent decrease platelet responses to all the inductors used. A comparison of patients taking and not taking aspirin (250 mg/day) revealed no differences both in the magnitude of an increase in platelet adhesion in the first 3 days and in that of its decrease on days 7-10 of AMI.
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PMID:[Adhesive activity of blood platelets in patients with stable or unstable angina pectoris and acute myocardial infarct]. 204 Dec 92


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