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)

Erythromelalgia is the main, pathognomonic and presenting symptom in patients with essential thrombocythemia and thrombocythemia associated with polycythemia vera. Complete relief from erythromelalgic and acrocyanotic pain is obtained with the cyclooxygenase inhibitors aspirin and indomethacin, but not with sodiumsalicylate, dipyridamol, sulfinpyrozone and ticlopedine. Thus, cyclooxygenase metabolites are necessary for erythromelalgia to develop. Local platelet consumption in erythromelalgic areas became evident by the demonstration of arteriolar fibromuscular intimal proliferation and occlusions by platelet-rich thrombi in skin biopsies, by the findings of shortened platelet survival times, significant higher levels of platelet activation markers beta-thromboglobulin, thrombomoduline and increased urinary thromboxane B2 excretion in thrombocythemia patients suffering from erythromelalgia. Aspirin treatment of erythromelalgia in thrombocythemia patients resulted in the disappearance of the erythromelalgic, thrombotic signs and symptoms, correction of the shortened platelet survival times, and a significant reduction of the increased levels of beta-TG, PF4, TM and urinary TxB2 excretion to normal. Erythromelalgia is frequently preceded or followed by atypical transient neurologic, ocular or coronary ischemic symptoms, which specifically respond to low-dose aspirin or reduction of platelet counts to normal. The broad spectrum of acropareshesias, erythromelalgia and acrocyanotic ischemia together with the episodic and transient atypical TIAs and ocular or coronary ischemic symptoms are caused by spontaneous activation and aggregation of hypersensitive platelets in the end-arterial microvasculature involving the peripheral, cerebral and coronary circulation of thrombocythemia patients. These microvascular circulation ischemic disturbances in thrombocythemia vera already occur at platelet counts in excess of 400 x 10(9) l(-1). Low-dose aspirin is highly effective and safe in the cure and prevention of thrombotic and ischemic events and does not elicit bleedings at platelet counts below 1000 x 10(9) l(-1). Spontaneous hemorrhages usually occur at very high platelet counts far in excess of 1000 x 10(9) l(-1) (HT) due to an acquired von Willebrand factor deficiency at increasing platelet counts. At platelet counts between 1000 and 2000 x 10(9) l(-1), thrombosis and bleeding (ETT and HT) frequently occur in sequence or paradoxically and low-dose aspirin does prevent thrombotic complications but aggravates or may elicit bleeding symptoms. Reduction of the platelet count to below 1000 x 10(9) l(-1) by platelet lowering agents usually results in the disappearance of the bleeding tendency and improvement of the von Willebrand syndrome, but the thrombotic tendency persists as long as platelet counts are above the upper limit of normal.
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PMID:Platelet-mediated microvascular inflammation and thrombosis in thrombocythemia vera: a distinct aspirin-responsive arterial thrombophilia, which transforms into a bleeding diathesis at increasing platelet counts. 1278 99

Acute arterial occlusion can be the result of acute thrombosis or systemic embolism. Paradoxical embolism of a venous thrombosis through a right-to-left shunt is an important cause of acute limb ischemia. We describe a young patient with acute limb ischemia who was found to have multiple deep venous thromboses causing arterial embolization through a patent foramen ovale. Essential thrombocytosis was found to be the risk factor for venous thromboses in this patient. The patient was managed with embolectomy and anticoagulation along with chemotherapeutic cytoreduction of platelet count. This case illustrates the importance of considering the systemic embolism as a cause of acute arterial occlusion. The presence of a hypercoagulable status such as chronic myeloproliferative disorder does not eliminate the possibility of systemic embolism in the event of acute arterial occlusion. Patients presenting with acute limb ischemia should be evaluated for embolic sources. The presence of deep venous thrombosis in such a patient should prompt the evaluation for a patent foramen ovale.
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PMID:Paradoxical arterial emboli causing acute limb ischemia in a patient with essential thrombocytosis. 1450 Dec 34

We investigated endothelial and in vivo platelet activation in a cohort of 52 patients with essential thrombocythemia (ET) and polycythemia vera (PV) before and after cytoreductive treatment, 22 healthy controls, and 17 patients with acute cerebrovascular ischemia (ACVI) and normal platelet counts. We measured platelet expression of CD62P and CD63 antigens and levels of soluble vascular cell adhesion molecule 1 (sVCAM-1). We found increased in vivo platelet activation in all patients with ET and PV, both before and after cytoreductive treatment, compared with controls. In patients with arterial thrombosis, platelet expression of CD62P, and in patients with erythromelalgia, expression of both markers was higher compared with expression in patients without thrombotic complications. In patients with ET and PV before and after treatment, sVCAM-1 expression was increased compared with expression in controls but also compared with expression in patients with ACVI and normal platelet counts. In patients with arterial thrombosis and erythromelalgia, in vivo platelet activation correlated with the level of sVCAM-1. Our findings indicated that in vivo platelet activation reflects intrinsic platelet defects in patients with ET and PV, persists after cytoreductive treatment, and results in endothelial damage, probably through release of angiogenic factors and/or activation of white blood cells.
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PMID:Markers of endothelial and in vivo platelet activation in patients with essential thrombocythemia and polycythemia vera. 1516 94

We report three cases of symptomatic acute carotid thrombosis occurring after carotid artery stenting (CAS). CASE 1: A patient presented with crescendo transient ischemic attacks on the second day after CAS. Ultrasound images demonstrated incomplete in-stent thrombosis due to plaque protrusion. The urgent surgical procedure consisted of stent removal and carotid thromboendarterectomy. CASE 2: A case of complete thrombosis of a carotid stent occurred 4 days after implantation in a patient with essential thrombocythemia diagnosed by chance. The surgical strategy included stent removal and carotid thromboendarterectomy. CASE 3: Cardiac multiple embolisms in a patient with chronic atrial fibrillation caused concomitant leg ischemia and acute carotid stent occlusion 2 hours after CAS. Cerebral reperfusion was established by embolectomy, without removing the stent. At the same time, the right leg ischemia was resolved by a thromboembolectomy with a Fogarty catheter. These three cases demonstrate that acute thrombosis after carotid stenting can be managed successfully with emergent surgical intervention. Thromboendarterectomy with stent removal or in selected cases, simple thromboembolectomy, can minimize neurologic sequelae in patients suffering from acute post-stenting carotid thrombosis.
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PMID:Surgical management of acute carotid thrombosis after carotid stenting: a report of three cases. 1627 59

Essential thrombocythemia (ET) is a clonal disorder of myeloid stem cells that causes thrombocytosis. As a result, ET can lead to vascular thrombosis and tissue ischemia; the association of coronary artery abnormalities such as myocardial infarction or unstable angina is rare. Here we describe a 45,-year-old male patient with essential thrombocythemia who presented with unstable angina. Elective coronary angiography showed total occlusion of mid right coronary artery and mid left anterior descending coronary artery. ET was confirmed by a bone marrow biopsy; treatment was started with antiplatelet therapy including aspirin and clopidogrel along with cytostatic therapy with hydroxyurea and anagrelide. After the initiation of the treatment, the platelet count decreased to 20 x 10(4)/microL. In addition, percutaneous coronary angioplasty was successfully performed with stent placement at the right coronary artery without hemorrhagic or thrombotic complications.
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PMID:Coronary artery intervention after cytostatics treatment in unstable angina patient with essential thrombocythemia. A case report and literature review. 1691 48

Vascular manifestations are the main clinical complication of essential thrombocythemia (ET). They include arterial thrombosis (30-40% of patients), venous thrombosis (5%), and ischemia due to microcirculatory disorders. Their incidence is highest at disease onset and diminishes gradually thereafter. The pathophysiology of ET involves dysmegakaryocytopoiesis, leading to platelet, leukocyte and vascular endothelial cell activation. The recent discovery of the V617F mutation of the JAK2 tyrosine kinase in 50-60% of patients with ET defined a new subgroup resembling polycythemia vera. This review examines biological findings and their correlation with the risk of thrombosis. Until now, stratification of the vascular risk has relied on a clinical case-control study showing that thrombotic and vascular complications are more frequent in patients over 60 and those with a history of thrombosis. These criteria, along with a rapid increase in thrombocytosis (>1500 G/L) leading to an increase in the bleeding risk, define a high-vascular-risk subgroup of patients warranting cytoreductive therapy. Although many biological markers of dysmegakaryocytopoiesis and cellular hyperactivation have been linked to an increase in the thrombotic risk, none is available for large-scale prediction of an intermediate vascular risk. The role of the JAK2 V617F mutation itself is controversial. Whatever the ET subgroup, antiplatelet therapy is largely used, based on the results of the ECLAP prospective controlled trial that showed a statistically significant reduction in thrombotic complications in patients receiving aspirin for polycythemia vera, a very similar myeloproliferative disorder.
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PMID:[Vascular complications of essential thrombocythemia]. 1807 51

Anagrelide is a phosphodiesterase III inhibitor utilized in the treatment of essential thrombocythemia. Anagrelide can be responsible for positive inotropic and chonotropic activity of the cardiovascular system. Moreover, it can induce vasospam directly on the epicardial coronary arteries. In the literature, it is well reported that this inhibitor can determine serious cardiovascular side effects, including congestive heart failure, arrhythmia and acute coronary syndrome. We describe the case of a 75-year-old woman who developed a mid-ventricular Takotsubo syndrome while on anagrelide therapy. Takotsubo cardiomyopathy, also known as left ventricular ballooning syndrome, is characterized by a reversible ventricular contractile dysfunction with akinesis and expansion of apical segments and hyperkinesis of the basal segments. Recently, atypical cases with akinesia and dilation of mid-ventricular segment and hypercontraction of the apical segments, also called mid-ventricular and inverted Takotsubo syndrome, have been described. Even though the pathogenesis of Takotsubo syndrome is poorly understood, several mechanisms have been proposed, including catecholamine-induced myocardial stunning, and ischemia-mediated stunning due to multivessel epicardial or microvascular spasm. We think that in our case, the adverse response of anagrelide therapy was determined, by accumulated dosage of the drug, through an intensive inotropic stimulation and a sympathetic hyperactivation in a vulnerable myocardium. To our knowledge, this is one of the first reports of an association between anagrelide therapy and Takotsubo cardiomyopathy.
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PMID:Atypical Takotsubo syndrome during anagrelide therapy. 1939 76

Thrombosis of the celiac artery trunk is a rare cause of acute abdominal pain. Thrombosis of the celiac artery carries a high mortality and morbidity when the diagnoses and treatment are delayed. It is frequently associated with other cardiovascular events. The most common etiology is atherosclerosis. 20-30% of cases may have symptoms of chronic mesenteric ischemia. Main goal of the treatment is to reestablish the diminished or stopped mesenteric blood flow and to avoid end-organ ischemia. Essential thrombocythemia is a chronic myeloproliferative disorder characterized by marked increase in thrombocyte number and clinical presentation may be with thrombotic episodes, hemorrhage, or both. To our knowledge this is the first report of celiac artery thrombosis and superior mesenteric artery stenoses in a patient with essential thrombocythemia. The patient was managed successfully with surgical treatment.
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PMID:Celiac artery thrombosis and superior mesenteric artery stenoses with essential thrombocythemia: a case report. 2330 60

The etiology of thrombocytosis can be classified into reactive and essential forms. The rate of thromboembolic events is higher in essential thrombocytosis, and these events include strokes, transient ischemic attacks, retinal artery or retinal vein occlusions, digital ischemia, and acute coronary syndrome. In a study of 732 medical and surgical patients with thrombocytosis, 88% had reactive thrombocytosis. Patients with reactive thrombocytosis do not require cytoreductive medications or antiplatelet treatment. We report a healthy 40-year-old man without any medical problems who developed a new episode of myocardial infarction associated with thrombocytosis after an episode of myocardial infarction followed by percutaneous coronary intervention. He had thrombocytosis, and his platelet function test did not reveal adequate inhibition. To treat his acute coronary syndrome, therapeutic enoxaparin was added, and clopidrogel was substituted with ticagrelor. We decided to start hydroxyurea to reduce platelets counts. Enoxaparin and hydroxyurea were discontinued when platelet count returned to baseline. JAK-2 and BCR/ABL mutations were negative. This case report highlights a clinical dilemma (reactive thrombocytosis), which is challenging in terms of management and pathophysiology.
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PMID:Reactive Thrombocytosis Associated with Acute Myocardial Infarction following STEMI with Percutaneous Coronary Intervention. 2482 6

Limb-shaking transient ischemic attacks are associated with transient regional cerebral hypoperfusion and severe carotid stenosis. We report two patients with unusual pathogenesis of limb-shaking attacks, one a 73-year-old woman with right-sided limb-shaking attacks and normal carotid angiography (recently diagnosed with essential thrombocytosis, antiplatelet agents eliminated her attacks) and the other a 56-year-old woman with peptic ulcer disease and multiple episodes of left-sided limb-shaking. Severe anemia was found along with bilateral carotid stenoses >70%. Correction of her anemia abolished her limb-shaking episodes. The presumed pathogenesis of limb-shaking transient ischemic attacks is transient focal cerebral ischemia from severe occlusive disease. Our two patients demonstrate that the mechanisms of ischemia may include other factors that affect oxygen delivery such as anemia or platelet disorders.
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PMID:Limb-shaking transient ischemic attacks: Two case reports with unusual pathogenesis. 2648 52


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