Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report 2 cases of occlusion of the internal carotid artery in young, non-atherosclerotic patients with essential thrombocythemia (ET). This complication of ET seems to be rare, but is probably underdiagnosed since transient ischemia, which is frequent in ET patients, is seldom explored by angiography. The excess of thrombocytes and the thrombopathy may account for the microvascular complications, but in the absence of any other contributory factor, occlusions of large arteries, such as the ICA, is more difficult to explain.
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PMID:[Internal carotid occlusion and essential thrombocythemia. 2 cases]. 219 54

More than a dozen primary hematologic disorders have been associated with ischemic stroke. Inherited deficiencies of antithrombin III, protein C, and protein S have been linked with stroke in case reports; optimal screening requires functional as well as antigenic assays. Antiphospholipid antibodies and lupus anticoagulants are the most frequently identified acquired states associated with ischemic stroke. Polycythemia vera, sickle cell anemia, sickle-C disease, and essential thrombocythemia are the major disorders of formed blood elements causing stroke. Special, step-wise screening for occult prothrombotic entities in stroke patients is recommended for young persons with stroke of uncertain cause, for those with prior venous thrombosis, for those with a family history of unusual thrombosis, and for those with no other explanation for recurrent stroke. Acquired, perhaps transient, abnormalities of platelets, coagulation inhibition, and fibrinolysis may contribute importantly to brain ischemia in synergy with other mechanisms, but at present these remain ill-defined. The contribution of prothrombotic diatheses to stroke is probably underrecognized and warrants further investigation.
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PMID:Hematologic disorders and ischemic stroke. A selective review. 186 63

Acral ischemia with lividity is a well-described dermatologic sign in the myeloproliferative diseases polycythemia vera and essential thrombocythemia. It has not previously been reported as a sign of chronic myelogenous leukemia (CML). We suggest the term acral lividosis to describe this clinical entity in patients with any myeloproliferative disease. We propose that the pathophysiology of acral lividosis in CML involves occlusion of small blood vessels of the skin by large, nondeformable myeloblasts, a process that has been shown histologically to occur in other organs in patients with CML. This process, called leukostasis, occurs in patients with CML who have over 50.0 X 10(9)/L (50,000/mm3) circulating myeloblasts. Patients manifest cardiorespiratory and central nervous system compromise, a clinical constellation known as the hyperleukocytosis syndrome. Acral lividosis occurred in a patient with CML in whom nearly every organ demonstrated leukostasis on autopsy.
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PMID:Acral lividosis--a sign of myeloproliferative diseases. Hyperleukocytosis syndrome in chronic myelogenous leukemia. 347 43

Essential thrombocythemia is a clonal myeloproliferative disorder, characterized predominantly by a markedly elevated platelet count without known cause. We report a case that was recognized during investigation of a transient ischemic attack, and review the neurologic findings in 33 patients with unequivocal essential thrombocythemia under prospective study by the Polycythemia Vera Study Group. Twenty-one patients had neurologic manifestations at some point during their course, including headache (13 patients), paresthesiae (10), posterior cerebral circulatory ischemia (9), anterior cerebral circulatory ischemia (6), visual disturbances (6) and epileptic seizures (2). All patients with neurologic symptoms responded satisfactorily to treatment, although continuous or repeated treatment was often required. Therapeutic recommendations include plateletpheresis for major thrombo-hemorrhagic phenomena, or megakaryocyte suppression with radioactive phosphorus, alkylating agents (such as melphalan), or hydroxyurea; minor symptoms may respond to platelet antiaggregating agents.
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PMID:Neurologic manifestations of essential thrombocythemia. 668 92

A thirty-eight-year-old man with primary thrombocythemia, von Recklinghausen neurofibromatosis, and myocardial-infarction-related left ventricular aneurysm with spontaneous echocardiographic contrast was followed up, suggesting that: 1. Neurofibromatosis may promote silent myocardial infarction or ischemia. Whether involvement of cardiac sensory nerves is a possible underlying mechanism remains nevertheless uncertain. 2. Platelets, whose role in the genesis of spontaneous echocardiographic contrast has been advocated, are probably not involved in this phenomenon, even in large numbers.
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PMID:Absence of enhancement of spontaneous echocardiographic contrast by thrombocytosis in a patient with left ventricular aneurysm, primary thrombocythemia, and von Recklinghausen neurofibromatosis: a case report. 834 82

Fifty consecutive patients with thrombocythemia (35 men and 15 women) were diagnosed as primary thrombocythemia (PT) in 30 and thrombocythemia associated with polycythemia vera (PV) in 20. The symptoms were platelet-mediated erythromelalgia in 16 PT and 15 PV, coronary artery disease in 3 PT and 2 PV, atypical cerebral ischemic attacks in 8 PT and 3 PV, paradoxical thrombosis and bleeding in 3 PT and 2 PV and hemorrhages alone in 6 PT and 2 PV patients. Erythromelalgia was localized in the forefoot sole and toes in 28, the fingertips in 9, the handpalm in 2. Untreated erythromelalgia progressed to acrocyanosis or peripheral ischemia with necrosis in a toe or fingertip in 14 cases. Painful red, warm and indurated erythromelalgic hot spots in the skin of the upper legs were misdiagnosed as superficial thrombophelebitis in 5 PT and 2 PV patients. Erythromelalgia in thrombocythemia already occurred at slightly increased platelet counts above 400 x 10(9)/l. The curative effect of aspirin on erythromelalgia in thrombocythemia was consistently accompanied by a significant increase of platelet counts. Erythromelalgia and bleeding paradoxically occurred in 5 patients at platelet counts between 1000 and 2000 x 10(9)/l. In this situation aspirin prevents erythromelalgic and microcirculatory circulation disturbances, but further increases the risk of serious bleeding complications. Presenting hemorrhagic manifestations in thrombocythemia were observed at platelet counts in excess of 1000 x 10(9)/l in 9 PT and 4 PV patients as severe epistaxis in 5, atypical ecchymoses in 3, gastrointestinal bleeding in 2 and secondary bleeding in 3. The concept of platelet-mediated erythromelalgia, thrombosis and hemorrhages in thrombocythemia is discussed.
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PMID:Erythromelalgic, thrombotic and hemorrhagic manifestations in 50 cases of thrombocythemia. 895 72

Neurologic and visual symptoms frequently occurred in 56 reported patients with essential thrombocythemia (ET). They may either precede or follow the well-known microcirculatory complications of ET of acroparesthesias, erythromelalgia, and acrocyanosis or ischemia of one or more toes. In comparison with transient ischemic attacks in patients with vascular risk factors, the usual neurologic presentation of ET consists of brief attacks of sudden cerebral or visual dysfunction, which can be either well localized or diffuse and entirely nonspecific. A dull and throbby headache usually lasting for several hours frequently accompanies the neurologic symptoms. Visual symptoms are less frequent and include transient monocular blindness and global symptoms such as scintillating scotomas and attacks of blurred vision. Neurologic and visual symptoms may leave minor sequelae but are generally nondisabling. The striking similarity to migraine, together with the absence of vascular risk factors and the striking efficacy of aspirin treatment supports the hypothesis that the ischemic neurologic and visual symptoms in ET are caused by shear rate-induced intravascular activation and aggregation of platelets with subsequent transient sludging or occlusion of the cerebral arterial microvasculature. Available data show that both the erythromelalgic distress and the ischemic neurologic attacks in ET are completely abolished by control of platelet function with low dose aspirin alone or reduction of platelet counts to normal as well as by the combination of platelet reducing therapy and low-dose aspirin. Early recognition and appropriate treatment of neurologic symptoms in patients with ET is therefore of great clinical relevance.
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PMID:Neurologic and visual symptoms in essential thrombocythemia: efficacy of low-dose aspirin. 926 53

To determine the clinicohematological factors predictive for the appearance of major vascular complications (MVC) in patients with essential thrombocythemia (ET), 148 consecutive such patients were retrospectively assessed for the development of MVC during a median follow-up of 58.5 months. Seventy-seven patients had vascular risk factors, and 37 a history of MVC at ET diagnosis. Forty-nine MVC were registered in 33 patients during the follow-up period. The actuarial probability of MVC was 27% at 6 years in the whole series, 35.6% for patients above 60 years, and 21.4% for patients younger than 60 years, whereas only one of the 36 patients younger than 45 years had MVC. At multivariate analysis, age >60 years, history of major ischemia and hypercholesterolemia were the variables associated with an increased MVC risk. These results suggest that all ET patients above 60 years should be treated, whereas in younger patients treatment decisions should be primarily based on the existence of risk factors for MVC.
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PMID:Major vascular complications in essential thrombocythemia: a study of the predictive factors in a series of 148 patients. 1002 86

Patients with polycethemia vera (PV) or essential thrombocythemia (ET) are at increased risk of arterial and venous thromboembolic events. Arterial ischemic complications occur in 24 to 43% of these patients, particularly those with cardiovascular risk factors (especially cigarette smoking). Non-atheromatous arterial thrombosis concerns all large and medium-sized vessels, particularly cerebral, limb, coronary and digestive arteries. Extensive complications have been described in patients with lower limb occlusive arteriopathy, particularly stent or bypass thrombosis, critical ischemia. Juvenile myocardial infarction or rapid postangioplasty coronary thrombosis may reveal certain myeloproliferative disorders, particularly ET. Venous thrombosis is more frequent in PV than in ET; superficial or deep venous thromboses are seen. Thromboembolic events occur in about 25-30% of the patients and account for one-third of the deaths. Mesenteric vein thrombosis, portal thrombosis, or suprahepatic vein thrombosis may occur in all myeloproliferative disorders, but the pathogenesis is not fully understood. Pulmonary hypertension may be the consequence of local thrombosis in the pulmonary vasculature or may be due to the high blood flow in the right heart cavities. Microvascular circulatory disturbance includes erythromelalgia, Raynaud's phenomenon, digital ischemia, acrocyanosis, blue toe syndrome, livedo reticularis, cutaneous ulcers or necrotic purpura. All these manifestations may precede the myeloproliferative disorder by several months.
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PMID:[What vascular events suggest a myeloproliferative disorder?]. 1114 2

Bilateral massive adrenal swelling (BAS) on computed tomography (CT) scan with no enhancement after injection of intravenous contrast media has been observed in two completely different clinical settings. On the one hand, BAS is the result of ischemic necrosis and subsequent hemorrhagic infarction in patients with sepsis and hypotension in critically ill situations. On the other hand, BAS is the result of microvascular thrombosis, ischemia, and secondary inflammatory swelling in the setting of thrombotic conditions such as antiphospholipid syndrome (APS), heparin-induced thrombocytopenia and thrombosis (HITT), and thrombocythemia. In this study we present evidence that the etiology of unilateral or BAS in reported cases of essential thrombocythemia (ET) and polycythemia vera (PV) is similar to the etiology of microvascular circulation disturbances in thrombocythemia caused by platelet-mediated inflammation and thrombosis in the peripheral, cerebral, and/or coronary endarterial microvascular circulation.
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PMID:Bilateral adrenal swelling as a cause of chest, back, and upper abdominal pain in essential thrombocythemia and polycythemia vera is due to microvascular ischemic thrombosis rather than to hemorrhage. 1248 64


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