Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0032463 (polycythemia vera)
 3,374 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A patient with sickle cell beta+-thalassemia had thrombocytosis and erythrocytosis due to a myeloproliferative disorder best classified as polycythemia vera. RBC counts were 6 to 8 million/cu mm and the red cell mass was 33 ml/kg. A higher red cell mass and an increased hematocrit value were prevented probably by factors related to the hemoglobinopathy, such as microcytosis and hemolysis. The diagnosis of polycythemia vera in patients with sickle cell disease may be difficult to document and the association of these disorders has not been previously reported. This patient's high red blood cell and platelet counts did not result in recurrent vasoocclusive crises.
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PMID:Sickle cell thalassemia, thrombocytosis, and erythrocytosis. 722 49

Essential thrombocythemia is characterized by proliferation of hematopoietic tissue predominantly involving megakaryocytes and resulting in marked thrombocytosis. The disorder has some clinical and laboratory features that resemble those seen in the clonal multipotent stem cell disorders chronic myelogenous leukemia, polycythemia vera, and agnogenic myeloid metaplasia. It has been argued that essential thrombocythemia should be classified together with those disorders as a myeloproliferative syndrome. However, without knowledge of the numbers and types of cells that are involved in essential thrombocythemia, this suggestion remains speculative. Three patients with thrombocytosis were studied. The diagnosis of essential thrombocythemia was considered to be firm in two patients and probable in the third one. The X-linked glucose-6-phosphate dehydrogenase locus was used as a cell marker. Whereas both A and B types of glucose-6-phosphate dehydrogenase were found in nonhematopoietic tissues, only a single-enzyme type was found in the granulocytes, red cells, and platelets from each patient. These data indicate that the disorders in these three patients are clonal and involve multipotent stem cells.
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PMID:Evidence that essential thrombocythemia is a clonal disorder with origin in a multipotent stem cell. 729 2

Uracil mustard was used for the treatment of thrombocytosis in 14 patients, eight who had polycythemia vera and six who had essential thrombocytosis. Intermittent treatment with 1 to 2 mg/day for 14 days was used for most patients, and continuous treatment was used for three patients. The nadir of the platelet count occurred during a mean period of five to seven weeks, and the mean duration between courses was seven months. The drug selectively depressed the platelet count, with a minimal effect on leukocytes and erythrocytes. Uracil mustard is an effective drug for the control of thrombocytosis.
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PMID:Uracil mustard in the treatment of thrombocytosis. 742 Jun 34

Nodular regenerative hyperplasia was found in nine patients who had hematological disease including polycythemia vera, agnogenic myeloid metaplasia, primary thrombocythemia, rheumatoid arthritis with thrombocytosis, multiple myeloma, and erythrocytosis associated with polycystic renal disease. Portal hypertension was suspected in three and features of hypersplenism were present in four. 2. Nodular regenerative hyperplasia occurred in livers which had widespread obliteration of portal vein radicals (obliterative portal venopathy). Morphometric analysis indicated that the portal vein lesions were predominately located in veins up to 0.2 mm in diameter and were significantly more frequent than similar lesions occurring in elderly persons. 3. The following pathogenesis of nodular regenerative hyperplasia is proposed: Thrombi, perhaps largely composed of platelet aggregates formed in the portal venous circulation or spleen, embolize to the liver and results in obliterative vascular lesions. Atrophy and regenerative nodule formation occur in response to the interruption of the portal blood supply.
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PMID:Nodular regenerative hyperplasia of the liver in hematologic disorders: a possible response to obliterative portal venopathy. A morphometric study of nine cases with an hypothesis on the pathogenesis. 743 53

The involvement of platelets in the pathogenesis of erythromelalgia, a frequent and characteristic microvascular thrombotic manifestation in patients with primary thrombocythemia and polycythemia rubra vera, was investigated by measuring the survival and turnover of 51Cr labeled autologous platelets in 10 patients with thrombocythemia complicated by erythromelalgia, in 10 asymptomatic thrombocythemia patients and in 6 subjects with reactive thrombocytosis. The mean platelet survival time of the erythromelalgia patients was 4.2 +/- 0.2 days, which is significantly decreased as compared with asymptomatic thrombocythemia patients (6.6 +/- 0.3 days, p < 0.001) and patients with reactive thrombocytosis (8.0 +/- 0.4 days, p < 0.001). The mean platelet survival time of asymptomatic thrombocythemia patients was significantly decreased (p < 0.01) as compared with reactive thrombocytosis patients. Treatment of erythromelalgia with aspirin increased the mean platelet survival time from 4.0 +/- 0.3 days to 6.9 +/- 0.4 days (p < 0.001) and was associated with an elevation of the platelet count of 216 +/- 30 x 10(9) platelets per liter (p < 0.001). Coumadin failed to improve platelet survival or symptoms caused by erythromelalgia. The increased platelet consumption in erythromelalgia is attributed to the formation of platelet thrombi in the arterial microvasculature. This conclusion is supported by the ability of aspirin to interrupt platelet consumption and clinical features of erythromelalgia.
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PMID:Platelet consumption in thrombocythemia complicated by erythromelalgia: reversal by aspirin. 779 31

In these last years the use of alpha-interferon (alpha-IFN) has received increasing attention especially in the onco-haematological field. alpha-IFN is particularly useful in the treatment of hairy cell leukemia, cryoglobulinemia, multiple myeloma and myeloproliferative syndromes (SMP). Among these latter conditions alpha-IFN must be considered as the treatment of choice of the early chronic phase of chronic myelogenous leukemia (LMC) in patients not eligible for allogenic bone marrow transplantation because its ability to induce a greater number of clinical remission and cytogenetic responses when compared to the classical chemotherapeutic agents. A myelosuppressive, non-leukemogenic effect and a more selective activity on the neoplastic hemopoiesis appear to be the most important advantages of alpha-IFN therapy. Based on the results obtained in LMC the use of alpha-IFN has been extended to the other SMP, essential thrombocytemia (TE), polycythemia vera (PV), idiopathic myelofibrosis with myeloid metaplasia (MMM). alpha-IFN is able to control thrombocytosis which often characterize the SMP so it appears to be particularly effective in TE. Actually a relatively limited literature is available about the alpha-IFN treatment of PV and MMM and so it is difficult to draw a final conclusion about the effectiveness of the treatment in these disorders. However, especially in PV, the use of this cytokine appears to be promising. The latest reports of the literature are here summarized and discussed.
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PMID:[Interferon-alpha in the treatment of myeloproliferative syndromes]. 785 89

In ten patients with essential thrombocythemia and polycythemia vera with thrombocytosis we have investigated the therapeutic effect of recombinant alpha-2a interferon (Roceron-A) given subcutaneously in a maintenance dosage of 3 million units three times weekly. The aim was to normalize the platelet count (< or = 400 x 10(9)/L). One of the secondary aims was to study platelet activity measured as beta-thromboglobulin (beta-TG) in urine. All but one patient could administer the injections and in all patients a significant reduction in platelet values was seen. The treatment was discontinued in three patients due to side effects of interferon, two because of hair loss (one with irreversible alopecia), and one because of depression. Three patients developed antibodies to alpha-2a interferon and a concomitant rise in the platelet level; in one patient therapy was switched to leukocyte alpha-interferon with an excellent response. The initial levels of beta-TG were elevated in 9/10 patients and were significantly reduced at 6 months in 4/5 patients not developing antibodies. Six patients are still on alpha-interferon therapy with a long-term follow-up of 3-3.5 years. We conclude that alpha-interferon therapy may be an alternative in patients with thrombocytosis and/or complications necessitating treatment.
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PMID:Alpha-2a interferon therapy and antibody formation in patients with essential thrombocythemia and polycythemia vera with thrombocytosis. 786 24

Little is known about the management and treatment of coronary thrombosis in polycythemia vera (PV) [1]. We describe a case of acute myocardial infarction in a patient with recently diagnosed PV and thrombocytosis. The patient underwent emergency catheterization with intracoronary thrombolysis and angioplasty of the left anterior descending coronary artery.
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PMID:Myocardial infarction and polycythemia vera: how should we treat it? 795 75

Platelet abnormalities are common in patients with chronic myeloproliferative disorders. In this study we report abnormalities in platelets morphology and function in 45 patients with chronic myeloproliferative disorders: 15 with chronic myelogenous leukaemia (CML), 8 with polycythemia rubra vera (PRV), 20 with essential thrombocythemia, and 2 with myelofibrosis (ME). We investigated flow cytometric features of platelets as measured with Technicon H1 technology, VIZ, mean platelet volume (MPV), plateletocrit), platelet distribution width (PDW), and modal platelet volume (PLT Mode) Platelet aggregation in response to ADP, epinephrine and collagen was used as functional test. In patients with ET, PRV and MF we found a significant decrease in platelet volume (both MPV and PLT MODE). Decrease in platelet aggregation and secretion in response to ADP, epinephrine and collagen was the most frequent abnormality in platelets function and was observed in most of patients with thrombocythemia in chronic myeloproliferative disorders.
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PMID:[Platelet defects in chronic myeloproliferative disorders]. 799 98

At presentation the history of an 87-year-old woman included progressive memory loss, repeated transient ischaemic attack, increasing fatigue, dizziness, palpitations and frequent falls. Investigations revealed erythrocytosis, leukocytosis, thrombocytosis, normal arterial oxygen concentration and an increased red cell volume. Polycythaemia vera was diagnosed and was successfully managed by phlebotomy with half a unit twice a week and rechecks of her haematocrit, initially; she reported marked improvement after 2 weeks of treatment. The alternative treatments for polycythaemia vera are discussed; in addition to venesection, conventional treatments include bone-marrow depressive agents such as phosphorus-32 and chemotherapy with agents such as hydroxyurea. More recent developments include isovolumic erythrocytophoresis, alpha-interferon and ticlopidine. All of the treatments are associated with complications, or other disadvantages, thrombotic complications in the case of phlebotomy, malignancies in the case of most myelosuppressive treatments, and problems of compliance in others. The optimal treatment for polycythaemia vera is a judicious combination of the alternatives, depending on the phase of the disease, the age of the patient, and other prognostic factors.
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PMID:Primary polycythaemia vera in the elderly. 802 Jun 39


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