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)

We postulate that the lesions of atherosclerosis arise as a result of some form of "injury" to arterial endothelium. This injury somehow results in alteration in endothelial cell-cell attachment or endothelial cell-connective tissue attachment, so that forces such as those derived from the shear in the flow of blood result in focal desquamation of endothelium. This is followed by adherence, aggregation, and release of platelets at the sites of focal injury. During the process of release, a mitogenic factor is secreted from the platelets which, together with plasma constituents, gains entry into the artery wall, resulting in focal intimal proliferation of smooth muscle cells. This intimal proliferation is accompanied by the synthesis of new connective tissue matrix proteins and often by the deposition of intracellular and extracellular lipids. Studies in cell culture of arterial smooth muscle have demonstrated that the principle mitogen present in blood serum is a platelet-derived factor that is present in all whole blood sera and missing in serum derived from platelet-free plasma. In the absence of the platelet factor, smooth muscle cells are quiescent in culture. This platelet mitogen is also active in vivo, since experimentally produced lesion of atherosclerosis induced mechanically by diet or by homocystine can be prevented if platelets are missing, as in thrombocytopenia, or if platelet function is impaired as a result of the use of platelet inhibitors such as dipyridamole. These studies point to the key role of the platelet in the stimulation of intimal smooth muscle proliferation that leads to the development of lesions of atherosclerosis.
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PMID:Response to injury and atherogenesis. 84 16

Breddin thrombagglutination test is followed up in patients with hypercoagulation states--atherosclerosis, atherosclerotic myocardiodysthrophia, angina pectoris gravis and acute myocardial infarction and hypocoagulation states--esential and symptomatic thrombopenia. TAT is positive in 88% of the patients with atherosclerosis and in patients with angina pectoris gravis and myocardial infarction TAT is Vth stage in 100%. TAT is zero stage in 91% in patients with thrombopenia and only in 9%-I stage. The term "zero stage" is introduced.
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PMID:[Thrombagglutination test (TAT) in hyper- and hypocoagulation]. 122 97

Heparins are a heterogenous group of naturally occurring glycosaminoglycans characterized by anticoagulant activity and a wide range of molecular weights (low molecular weight or fractionated heparins evolving within the past two decades). Cofactors for endogenous inhibitors of coagulation (antithrombin III and heparin cofactor II), heparin administration results in a hypocoagulable state. Various platelet activities, including inhibition of activity induced by platelet-derived growth factors on vascular smooth muscle, also have been noted. Divorced of anticoagulant nature, novel applications may include a role in atherosclerosis prevention, acceleration of collateral coronary as well as peripheral circulation (i.e., angiogenesis), and continued (chronic) post-myocardial infarction therapy. Established indications include treatment of various thrombotic diseases, unstable angina, and thrombosis chemoprophylaxis in medical/surgical patients. The antithrombotic potential of the heparins is used also in thrombosis management related to extracorporeal circulatory assistance or dialysis devices. Heparin's therapeutic potential in the postphlebitic syndrome as well as in acute treatment of myocardial infarction (primarily and adjunctively with various thrombolytic agents) continues to undergo evaluation; however, early data review shows favorable trends for its inclusion in situations that favor thrombus generation (e.g., anterior myocardial infarction). Although associated with thrombocytopenia or hypertransaminasemia, the heparins are relatively well tolerated. In a small subset of patients, a severe thrombocytopenia may ensue, which generally resolves on medication withdrawal. As this class of glycosaminoglycans becomes better characterized, new indications may emerge for both native and the newer fractionated heparins.
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PMID:Pharmacodynamics, clinical indications, and adverse effects of heparin. 132 34

We report a retrospective, clinicopathologic study of 139 patients who died during treatment of a severe burn. Fifty-three percent of the patients had central nervous system (CNS) complications-infections, cerebral infarcts and hemorrhages, metabolic encephalopathies, central pontine myelinolysis, and cerebral trauma. Children and adults were equally affected. Sixteen percent of the patients had a CNS infection. Candida species, Staphylococcus aureus and Pseudomonas aeruginosa caused almost 80% of them. S. aureus and candida caused cerebral microabscesses and septic infarcts. P. aeruginosa caused meningitis and infarcts due to meningitis. CNS infections arose as a result of spread from a systemic source. The major risk factors for CNS infection were an extensive burn, S. aureus endocarditis, and a burn wound infection due to candida or P. aeruginosa. Patients with burns of less than 30% of the surface area of their body, those without a systemic infection, and those in the first week after their burn were at low risk. Eighteen percent of the patients had cerebral infarcts. In almost half the patients, the infarcts were caused by septic arterial occlusions or other complications of the burn, viz, disseminated intravascular coagulation (DIC) and septic shock. In only one-third of the patients were infarcts due to atherosclerosis, atrial fibrillation, or other causes prevalent in the general population. Intracranial hemorrhages were only one-fifth as frequent as infarcts and were due to DIC and thrombocytopenia, caused by bacteremia. Diagnosis during life was difficult, because the neurologic picture of focal cerebral lesions and meningitis was indistinguishable from that of metabolic encephalopathies, and because many patients had more than 1 neurologic complication. However, our results suggest that a clinical approach that includes analysis of risk factors for CNS infection, cerebral imaging, examination of cerebrospinal fluid, and tests for DIC can lead to a neurologic and microbiologic diagnosis in most patients.
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PMID:Central nervous system complications of thermal burns. A postmortem study of 139 patients. 152 3

The antiphospholipid syndrome was diagnosed in 19 of 1078 patients treated between 1987 and 1991. All patients with antiphospholipid syndrome had either anticardiolipin antibody (16/19) or lupus anticoagulant (10/19); three patients had thrombocytopenia, eight patients had a prolonged partial thromboplastin time, and 10 patients had an elevated erythrocyte sedimentation rate. The most common site of involvement was the cerebral circulation (nine patients), manifested by transient ischemic attacks or stroke. Eight patients had upper extremity disease, characterized by symptoms of Raynaud's phenomenon, with angiographic lesions involving the brachial, radial, ulnar, and/or digital arteries. Lower extremity disease occurred in seven patients, with clinical presentations similar to those of atherosclerosis and varying angiographic patterns. In comparison with the population having atherosclerosis, patients with arterial manifestations of antiphospholipid syndrome were more likely to be women (13 of 19 versus 411 of 1078, p less than 0.02), were significantly younger (46.2 years versus 63.6 years, p less than 0.0001), did not smoke (1 of 19 patients versus 700 of 1078, p less than 0.0001), had a higher percentage of upper extremity involvement (8 of 18 versus 13 of 1078, p less than 0.0001), and had a higher incidence of early graft failure (9 of 12 grafts versus 13 of 371 grafts, p less than 0.0001). The syndrome is associated with the repetitive failure of vascular reconstructions and occlusion of native vessels. Antiphospholipid syndrome should therefore be suspected in young, female, nonsmokers with vascular disease, especially those with involvement of the upper extremity, cerebrovascular disease with normal findings on extracranial carotid angiography, and premature graft failure.
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PMID:Vascular disease in the antiphospholipid syndrome: a comparison with the patient population with atherosclerosis. 172 74

Much of the research related to cardiopulmonary bypass in recent years has been directed toward defining the changes in plasma and blood cells during bypass. In this review, recent information is reexamined for six areas of current interest. These areas are complement activation, immune response, anaphylactic reactions, coagulation, and cerebral dysfunction. Complement may be activated by either the classical or alternate pathway during cardiopulmonary bypass and protamine administration. Membrane oxygenators appear to diminish the degree of complement activation. Complement is a major factor in the whole body inflammatory response; which often accompanies cardiopulmonary bypass. A product of complement activation, C5a- desArg, causes activation and aggregation of granulocytes. Other products of complement activation lead to lysis of blood cells including granulocytes and red cells. Bubble oxygenators appear to have a distinct disadvantage compared to membrane oxygenators regarding infection. Airborne microorganisms are more likely to be entrained into circulating blood with bubble oxygenators than with membrane oxygenators. Bubble oxygenators cause a greater decrease in leukocyte number and function than membrane oxygenators. Anaphylactic reactions have been associated with use of antibiotics, blood products, protamine, and volume expanders during cardiopulmonary bypass. Protamine reactions may be on an immunological basis or due to direct toxicity of the drug. Free radicals including superoxide, hydrogen peroxide, and the hydroxyl radical may be generated during cardiopulmonary bypass and reperfusion. Free radical scavengers including; vitamin E, coenzyme Q, vitamin C, mannitol, and glutathione have been studied. The avoidance of blood transfusion because of risk of transmitted infection including AIDS has become a major goal in cardiac surgery. Factors that correlate with increased transfusion requirement include low hematocrit, female gender, increased age, small body size, low ejection fraction, reoperation, and emergency operation. Heparin resistance due to antithrombin III deficiency is being recognized more commonly. Antithrombin III deficiency may be corrected with fresh frozen plasma. Patients with heparin induced thrombocytopenia may be difficult to manage. Several management protocols are suggested. The most straightforward appears to be the use of aspirin preoperatively and platelet transfusions postoperatively. The incidence of cerebral dysfunction after cardiopulmonary bypass depends on the sensitivity of the test or indicator used. Perioperative stroke is associated with intrinsic cerebrovascular disease and atherosclerosis of the ascending aorta. Retinal angiograms during cardiopulmonary bypass show that microemboli are very common. Cerebroplegia has been shown to extend the period of safe circulatory arrest in animals. Much of the new knowledge concerning cardiopulmonary bypass is the result of close collaboration between cardiac surgeons and nonsurgical scientists.
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PMID:Pathophysiology of cardiopulmonary bypass: current issues. 213 41

Serotonin metabolism was investigated in 15 patients (8 women, 7 men) with decreased renal function (clearance of endogenous creatinine = 0.07-0.74 ml/s) and compared to the values obtained in healthy controls. In spite of thrombocytopenia, the patients' platelet serotonin concentrations (1.99-47.6 nmol/10(9) platelets) as well as the plasma serotonin levels (190-2,176 nmol/l) were significantly higher than in controls (1.36-7.87 nmol/10(9) platelets, p less than 0.05; 0-500 nmol/l, p less than 0.001). The low urinary serotonin output (0-414 to 167-1,187 nmol/24 h in controls, p less than 0.001) probably reflects its decreased synthesis in the residual renal parenchyma. 5-Hydroxyindolacetic acid was excreted in normal amounts. The impairment in serotonin metabolism is closely correlated with the decrease in renal function. The data document accumulation of serotonin in the circulation. This impairment could contribute to platelet hyperaggregation and/or consumptive hypocoagulation, maintenance of hypertension, and acceleration of atherosclerosis.
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PMID:Serotonin metabolism in patients with decreased renal function. 247 19

We described here a seventy-one year-old male, who had repeated disseminated intravascular coagulation related to atherosclerosis and aneurysm of the aorta, and was successfully treated with self-subcutaneous injection of heparin sodium. He developed gingival bleeding and purpura in 1977. He was first treated with prednisolone (30 mg/day) and ACTH-Z under the diagnosis of idiopathic thrombocytopenic purpura associated with chronic thyroiditis, since platelet count (0.2 x 10(4)/microliters) was markedly decreased and megakaryocytes in the bone marrow were increased. By the treatment, platelet count recovered to 16.7 x 10(4)/microliters, while fibrin-degradation product levels were increased and hypofibrinogenemia developed, suggesting disseminated intravascular coagulopathy. Additional treatment with heparin was effective, and the coagulation studies became normal. In 1980, he again developed the episode with thrombocytopenia. At this time, prednisolone did not improve the episode, but heparin was effective. Since 1983, an enlargement of abdominal aorta had been recognized and gradually progressed. In 1983, he developed lumbago and abdominal pain, and received an emergency operation using artificial Y-graft vessel under the diagnosis of rupture of the aneurysm. There was no evidence of consumption coagulopathy at that time. He had been well until 1987, when he developed the third episode of thrombocytopenia with gingival bleeding. Thrombocytopenia was controlled with the treatment of heparin, but needed a continuous treatment with heparin. Thereafter, he has been well managed with self-injection of the anticoagulant, heparin sodium.
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PMID:[Disseminated intravascular coagulation related to atherosclerosis and aneurysm of aorta: successful management with subcutaneous self injection of heparin sodium]. 259 49

A thrombus is an abnormal manifestation of normal haemostasis occurring on the internal surface of the blood vessels. Endothelial injury is the first event which ultimately may result in arterial thrombosis. Platelets stick to subendothelial components, are activated and release a number of mediators which aggregate new platelets. Simultaneously, thrombin is generated on the platelet surface and enhances these phenomenons. Due to the high blood flow which avoids local thrombin accumulation, arterial thrombosis is mainly composed of platelets with a poor fibrin content. A mural arterial thrombosis may embolize, be incorporated in the vessel wall, or occlude the lumen of the artery. Platelets are involved in the development of atherosclerosis: severe thrombocytopenia or von Willebrand disease protect efficiently against experimental atherosclerosis; several clinical conditions known to increase cardiovascular diseases are also associated with an increased platelet aggregability; in contrast, polyunsaturated fatty acids decrease platelets aggregability and protect against vascular diseases.
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PMID:[Role of platelets in atherosclerosis and arterial thrombosis]. 259 16

Role of platelet-derived growth factor (PDGF) in myointimal thickening described in "response to injury" hypothesis was investigated with artery of rats in culture and with air-injured artery of rats. PDGF promoted cell growth in ring preparation of carotid artery in culture denuded with citrate. It did not promote any cell growth in preparations without denudation. Trapidil, a PDGF antagonist, inhibited the cell growth promoted by PDGF in the denuded arterial ring. Systemic injection of PDGF was performed for 8 days to rats with thrombocytopenia induced by injections of anti-platelet serum. This treatment caused myointimal thickening of carotid artery 10 days after denudation by means of air injury. Trapidil at oral intake levels of 1, 3 and 30 mg/kg/day inhibited this change observed in denuded site of artery. Trapidil at oral intake of 6 mg/kg/day also inhibited myointimal thickening observed 15 days after denudation of carotid artery by air injury in normotensive and spontaneous hypertensive rats both with normal platelet counts. These results evidenced the role of PDGF in myointimal thickening described in "response to injury" hypothesis and clinical use of trapidil may be a new approach to the treatment of atherosclerosis.
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PMID:Evidence for "response to injury" hypothesis. 715 55


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