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)

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 7-year-old, crossbred, desexed bitch had a fluctuating illness of more than 6 months duration, with signs of inappetence, reduced exercise tolerance, restlessness, panting, black diarrhoea, and red eyes and ears. Haematological examination disclosed persistent polycythaemia, reticulocytosis, normoblastaemia , and normal total plasma protein concentration when not dehydrated. Splenomegaly was present, but there was no evidence of significant pulmonary, cardiac or renal disease on physical, radiographic or electrocardiographic examination. Further investigations revealed normal arterial Po2 and oxygen saturation, and increased total erythrocyte volume. Primary polycythaemia was diagnosed. The dog was rendered anaemic by bleeding, then treated with a single injection of radioactive phosphorus. The patient has had no recurrence of signs and remains well 50 months later.
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PMID:Primary polycythaemia in a dog. 673 71

An example of chocked disk of 3-4 diopters (right eye) and 4-5 diopters (left eye) in a patient with cerebral alteration (encephalomalacia respectively bleeding) suffering from polycythemia vera is discussed in the light of own observation, literature, differential diagnosis, pathogenesis, and therapy. An internal treatment by radioactive phosphorus and blood-letting gave restitutio fere ad integrum.
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PMID:[Involvement of the eye in polycythemia vera (Vaquez-Osler disease)]. 687 59

In studies to determine the optimal treatment for polycythemia vera, 431 previously untreated patients whose disease met established diagnostic criteria were entered into a prospective, randomized controlled trial between 1967 and 1974. Three treatment regimens were used: phlebotomy alone, chlorambucil supplemented by phlebotomy, or radioactive phosphorus supplemented by phlebotomy. Despite minor differences in age and sex, the three groups were comparable in initial hematocrit, white-cell and platelet counts, and disease-related symptoms. The median duration of follow-up is now more than 6 1/2 years. As of February 15, 1980, there were no statistically significant differences in survival among the groups. However, the risk of acute leukemia in patients given chlorambucil was 2.3 times that in patients given radioactive phosphorus and 13 times that in patients treated with phlebotomy alone. The increased incidence of leukemia during chlorambucil treatment is statistically significant (P less than or equal to 0.002); accordingly, the Polycythemia Vera Study Group has discontinued the use of chlorambucil in the treatment of polycythemia vera.
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PMID:Increased incidence of acute leukemia in polycythemia vera associated with chlorambucil therapy. 700 81

Between 1971 and 1981, 74 patients with polycythemia vera were treated with pipobroman using a high-dose induction, low-dose maintenance regimen. Complete remission was achieved in 51 of 54 previously untreated patients (94.4%) and in 17 of 20 patients (85%) previously treated wih radioactive phosphorus (32 p) and busulfan. The earliest modifications were noted on day 16, and on the average, blood counts were normal by day 45. Thirty percent of the patients relapsed, the mean duration of the remission being 17.5 mo. Following recurrence pipobroman was consistently effective in the same doses but the mean duration of the next remissions was 10 mo. Transient leukopenia and thrombocytopenia occurred in 8% and 7% of patients, respectively, during initial phase, and anemia was noted in 3 patients. Macrocytosis was noted in 20% of patients during maintenance phase. Three cases of acute leukemia and 3 cases of osteomyelosclerosis were recorded, all occurring in patients who had previously received 32 p and/or busulfan. No hematologic malignancies were seen among patients treated with pipobroman alone; follow-up exceeded 6 yr for 20 patients and the median follow-up period was 3.6 yr. Pipobroman appears safer than other alkylating agents; it is as effective as 32 p and works more quickly. Longer follow-up will be required to evaluate the drug's oncogenic potential, which is still not known.
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PMID:Pipobroman therapy of polycythemia vera. 707 17

6-thioguanine, an antimetabolite not potentiated by allopurinol, has been used in the treatment of 29 patients with polycythemia vera. All but two of the patients had been treated previously by venesection and/or radioactive phosphorus (32p) and/or alkylating agents. The usual dose was 40-160 mg daily alternate weeks according to individual response. The treatment period varied from 6-66 months (mean, 31 months). Of 27 evaluable patients 24 (89%) responded to treatment and at one year there was a significant fall in all blood count parameters. Seven patients relapsed while on treatment and four were withdrawn because of side effects. 6-thioguanine merits further evaluation in the management of polycythemia vera, particularly in those patients who have received large cumulative doses of 32p and/or alkylating agents and in whom an alternative mode of therapy is desirable.
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PMID:Secondary treatment of polycythemia rubra vera with 6-thioguanine. 709 23

We studied the effects of recombinant interferon alpha-2a (IFN-alpha) in 36 patients with polycythemia vera (PV) previously treated with phlebotomy and/or conventional cytostatic agents. In each patient, after at least 2 months of discontinuation of any cytotoxic therapy, the hematocrit (Hmt) was first brought to normal value by phlebotomy; IFN-alpha treatment was then begun at a starting dose of 3,000,000 IU s.c. three times a week. Response to treatment, which was assessed monthly, was defined as persistent normalization of Hmt without concomitant phlebotomy; in non-responsive patients the initial IFN-alpha weekly dosage was progressively increased. Twenty patients were responsive with a median duration of response of 7 months (range 2-25+ months); out of these, 7 patients are still under treatment and responsive at 13+, 17+, 20+, 22+, 23+, 25+, 25+ months. These findings indicate that a cohort, although small, of patients with PV (19.4%) are persistently sensitive to IFN-alpha; in this subset of patients, this cytokine can therefore provide a useful treatment option, since, contrary to conventional therapeutic approaches such as radioactive phosphorus, cytostatic agents, or phlebotomy, IFN-alpha is devoid of harmful side effects.
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PMID:Role of interferon alpha-2a in the treatment of polycythemia vera. 783 94

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

With the very long life expectancy of Polycythaemia Vera late complications are often observed: progressive resistance to treatment, bad tolerance to maintenance by phlebotomy, progression towards myelofibrosis. Resistance to phosphorus 32 is reflected by a progressive reduction in the duration of remission and by a gradually decreasing remission rate. A complete resistance appears after a mean duration of disease of 7 years. In the maintenance treatment by hydroxyurea, there is a secondary resistance in one third of cases with a poor control of the excess platelets. Resistance to Pipobroman is less frequent (10%). The phosphorus resistance could be delayed by addition of maintenance treatment by Hydroxyurea. In the presence of resistance to 32 P, Hydroxyurea and Pipobroman often remain effective. In the case of resistance to Hydroxyurea or Pipobroman, we have several possibilities: inversion of chemotherapy, other chemotherapy as Busulfan, 32 phosphorus. Intolerance of phlebotomy as baseline treatment is almost constant. Three complications lead to discontinuation of phlebotomy: development of cardiovascular complications, raised platelet count to above 800,000 and often more than 1 million, progressive increase in the size of the spleen with appearance of signs of myeloid splenomegaly. Exclusive phlebotomies are not indicated as baseline treatment of Polycythaemia Vera. The progression towards myelofibrosis (spent phase, post polycythaemia myeloid splenomegaly) increases with the duration of the disease and the frequency of transformation differs according to the type of treatment. The time to transformation is much shorter in the patients treated by phlebotomy. The transformation towards myelofibrosis is demonstrated by bone marrow biopsy and isotope investigations (bone marrow scintigraphy and kinetic by iron 59 and chromium 51).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical and laboratory assessment and therapeutic problems in longstanding polycythaemia vera. 803 42

Polycythaemia vera is a clonal disorder of the haemopoietic stem cell causing a pathologic expansion of the erythroid and sometimes the megakaryocytic and myeloid elements. In order to avoid the possible mutagenic effects of radioactive phosphorus, alkylating agents and hydroxyurea, since 1988 alpha-IFN has been used for the treatment of PV and has been shown to induce and maintain haematological remission. We describe a 24-year-old PV patient with chromosomal abnormalities who achieved not only a reduction of the proliferation of erythroid elements and reticulin content in the bone marrow, but also a complete cytogenetic remission after IFN treatment.
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PMID:Cytogenetic conversion in a case of polycythaemia vera treated with interferon-alpha. 819 36


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