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)

The characteristic temperature-dependent pruritus in polycythemia vera (PV) is described. The triggering factor seems to be a sudden decrease in skin temperature, e.g. after a hot bath or shower. The sudden onset and limited duration of the pruritus might suggest an activation or release of some humoral factor(s). In a controlled study we showed that aspirin alleviates this particular pruritus. Therefore, the possibility of prostaglandin and platelet involvement was considered. It was found that substances such as PGE2 and serotonin, produced and released by platelets, could elicit pruritus in healthy volunteers when injected intradermally and that PGE2 enhanced the cutaneous responses to serotonin. Studies of platelet aggregation did not reveal any abnormalitites in the PV patients but ADP was shown to sensitize platelets to adrenaline-induced aggregation in vitro. Although not proven the following hypothesis is suggested: a combination of ADP, emerging from erythrocytes, and catecholamines released from adrenergic vasoconstrictor nerves when the skin is cooled down, might stimulate platelets to aggregation in skin vessels and to production and release of pruritogenic factors.
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PMID:Pruritus in polycythemia vera: treatment with aspirin and possibility of platelet involvement. 9 9

A patient with Osler's disease (hereditary haemorrhagic telangiectasia) was admitted to hospital because of obstinate, profuse conjuctival bleeding occurring without any known preceding rrauma. Extensive examination of the haemostatic mechanism revealed an impaired platelet function reflected in defective platelet aggregation by ADP, collagen adrenalin and defective clot retraction. This platelet dysfunction, whose association with conjunctival telangiectasia was hitherto unknown, impaired the patient's already deficient primary haemostasis following the vascular anomaly and apparently contributed to the severity of the bleeding which could only be checked surgically. The findings seem to warrant investigation of the platelet function in patients with Osler's disease. In the event of platelet dysfunction drugs, such as acetylsalicylic acid (aspirin), indomethacin, dextrans as well as transfusions with bank blood are contraindicated.
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PMID:Conjunctival bleeding in Osler's disease with associated platelet dysfunction. A case report. 58 Mar 38

Platelet activation in patients with myeloproliferative disorders is often suggested by increased platelet alpha-granule secretion and an acquired storage pool defect of dense granules. To determine whether activated platelets circulate in patients with chronic myeloproliferative disorders, we evaluated the binding of monoclonal antibodies against activation-dependent epitopes on resting platelets (P 12, CD 63, and CD 62) in 12 patients with prominent megakaryocytic proliferation (8 patients with essential thrombocythemia, 2 with chronic myeloid leukemia, and 2 patients with polycythemia rubra vera). In addition, platelet aggregation in response to collagen, adenosine diphosphate, platelet activating factor, and agglutination with ristocetin was investigated. In 3 patients there was an increased percentage of platelets binding at least 1 activation marker. In 2 other patients, a trend towards increased antibody binding was observed. Binding of the antibody to thrombospondin (P 12) was related to expression of the GMP 140 protein (CD 62, r = 0.76, p = 0.004). There was no correlation of platelet aggregation defects in vitro to increased expression of platelet activation markers or to thrombohaemorrhagic complications. However, circulating activated platelets were detected in three out of five patients with a history of bleeding or thrombotic complications. The results of this preliminary study suggest that some but not all patients with myeloproliferative disorders showed increased amounts of circulating activated platelets. The relation of bleeding and thrombotic complications to the expression of activation-dependent epitopes on platelets in myeloproliferative disorders requires further investigation.
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PMID:Circulating activated platelets in myeloproliferative disorders. 170 9

Red blood cell metabolism was studied in male patients with polycythemia rubra vera (Vaquez disease) and compared to a reference sample of 74 healthy adults. A total of seventeen enzyme activities and seventeen metabolite concentrations were determined. In addition to the modifications of the hematological parameters among the polycytemic patients significant variations were detected: a decreased content of hemoglobin in the cells; significantly decreased levels of ATP, ADP and AMP associated to an accelerated turn over of these metabolites; an acceleration of the glycolytic pathway associated with an increase of the energetic charge and levels of 2-3BPG and G1-6BP. In polycythemia rubra vera patients, the modifications of the hematological and biochemical parameters were compared to previous results obtained in high altitude residents (adaptative hypoxia) and in red cells belonging to new borns.
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PMID:Consequences of moderate hypoxia on red cell glycolytic metabolism in polycythemia rubra vera. 204 71

The content of platelet adenine nucleotide in chronic myeloproliferative disorders (CMPD) and multiple myeloma (MM) was measured by a luciferin-luciferase method by Holmsen and Weiss. The release of ATP and ADP from platelet during aggregation induced by collagen and epinephrine were analyzed. The total 42 investigated cases consisted of 11 cases of polycythemia vera (PV), 7 cases of essential thrombocythemia (ET), 7 cases of chronic myeloid leukemia (CML), 9 cases of blastic crisis of CML (BC-CML), and 8 cases of multiple myeloma (MM). The healthy control was 19 cases. In CMPD and MM, the amount of ATP was normal in spite of decrease of ADP; therefore, the ratio of ATP/ADP increased. On the other hand, the ATP significantly increased in BC-CML. MM revealed a remarkable increase of ATP release due to the aggregation by collagen and epinephrine. The maximal rate of aggregation of collagen and epinephrine using Lumi-aggregometer indicated a positive relationship with the ATP release by the Holmsen and Weiss' method. The platelet volume in CMPD increased showing correlation with ATP content and not with ADP. In conclusion, CMPD and MM are regarded as acquired qualitative disorders of platelets or secondary storage pool diseases from the view points of the abnormalities in ATP, ADP contents and their release. However, BC-CML and MM revealed some different change from that of CMPD.
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PMID:[ATP and ADP of platelets in chronic myeloproliferative disorders and multiple myeloma]. 271 95

Platelet function and factor VIII complex were evaluated in ten patients with polycythemia rubra vera. Seven patients showed abnormal epinephrine-induced aggregation. The intracellular concentrations of adenosine diphosphate (ADP) were below normal, and the ratio of adenosine triphosphate (ATP)/ADP was greater than normal. In four of eight cases, there was a decrease in ristocetin cofactor activity and a reduction in the slowly migrating forms of vWF:Ag on crossed immunoelectrophoresis. Defect of large multimers of vWF:Ag was also observed. The ratio of vWF:Ag to ristocetin cofactor was elevated in these patients. Plasma from the patients had no effect on normal plasma except in one case, in which isolated IgG appeared to cause inactivation of ristocetin cofactor. Treatment with 1-deamino-8-arginine vasopressin caused correction of the vWF abnormalities with rapid return of ristocetin cofactor to baseline in some patients. The present study shows that the alterations of multimeric structure of vWF occur in more than 50% of patients with polycythemia rubra vera and are in some part due to the inhibitor specific for vWF.
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PMID:Acquired von Willebrand disease in patients with polycythemia rubra vera. 311 41

Platelet aggregation was studied in 18 patients with myeloproliferative disorders, including 14 patients with chronic myelogenous leukemia, 2 with polycythemia vera, 1 with myelofibrosis and 1 with thrombocythemia. Fourteen patients (78%) were abnormal in epinephrine-induced platelet aggregation, while 3 (17%) and 4 (22%) cases showed impaired ADP or collagen induced platelet aggregation, respectively. A significant decrease of total ADP content in resting unstimulated platelets and of the amount released to the medium after aggregation was found in all six patients who were evaluated. ATP and AMP in resting platelets tended to be slightly higher in patients compared with the control group. Released ATP was also significantly less, and the percentage release of ADP and ATP was significantly decreased in patients. A storage pool deficiency of adenine nucleotides was considered to be responsible for abnormal platelet function in patients with myeloproliferative disorders.
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PMID:Abnormalities of epinephrine-induced platelet aggregation and adenine nucleotides in myeloproliferative disorders. 653 53

The clinical value of a new in vitro test of hemostasis, which we have called Filter Bleeding Time (FBT), was determined in 59 patients referred because of a suspected bleeding disorder. FBT is based on the progressive slowing of the drop rate of citrated blood through a filter of woven Dacron under constant pressure as platelet aggregates occlude the filter. The value for FBT is defined as the time when the blood drop interval has reached 1 minute. The Mayo modification of the Ivy bleeding time (IBT) was performed in all patients; platelet response to ADP, collagen, epinephrine and arachidonate was performed in 24 patients. In 30 normal volunteers FBT measured 1-3 hr after venipuncture was 2.8 +/- 1.5 (means +/- 1SD) min. The FBT was prolonged in 3 of 3 patients with Glanzmann's thrombasthenia, 2 with disseminated intravascular coagulation, 1 with chronic lymphocytic leukemia, 1 with myelofibrosis, and 1 who had taken aspirin. In 6 patients FBT was prolonged while IBT was normal: 4 after taking aspirin, 2 with polycythemia vera. All 6 had reduced platelet aggregation (PA) to ADP (5 microM), collagen (2 mg/ml), epinephrine (5 microM) and/or arachidonate (1.7 mM). In 3 patients FBT was normal while IBT was abnormal: 1 with disseminated intravascular coagulation, 2 undiagnosed; 1 of these 3 had abnormal PA. Of 6 patients with von Willebrand's disease, FBT was prolonged in 5 and borderline in 1; IBT was prolonged in 3, normal in 1, and not done in 2 infants.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical evaluation of a new test of hemostasis: the Filter Bleeding Time. 674 May 68

We have previously reported that polymorphonuclear granulocyte (PMN) and monocyte oxidative metabolism is reduced in polycythemia vera (PV) patients compared to healthy control subjects, after stimulation with cell surface receptor-dependent stimuli such as n-formyl-methionyl-leucyl-phenylalanine, leukotriene B4 and platelet-activating factor (PAF). In contrast, the oxidative response to phorbol myristate acetate (PMA) is normal. We now show that, in PV patients exhibiting significantly reduced PMN chemiluminescence after PAF stimulation, PAF induced platelet aggregation was also reduced--40 +/- 3% compared to 50 +/- 2% in controls (p < 0.01). The defective aggregatory response to PAF in PV remained over a wide range of stimuli concentrations. Platelet aggregation induced by PMA and ADP, however, was similar in PV and controls. In contrast, platelet aggregation induced by PAF (or by ADP and PMA) was not significantly reduced in patients with chronic myeloid leukemia, essential thrombocythemia and multiple myeloma. Furthermore, the release of beta-thromboglobulin was slightly but not significantly higher after PAF stimulation in PV and this argues against an abnormal PAF receptor as the cause of the defective function. Thus, not only PV neutrophils, but also PV platelets show a discrete defect of the stimulus response coupling for PAF, indicating a disease-specific abnormality that appears to be of clonal origin.
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PMID:Stimulus-specific defect in platelet aggregation in polycythemia vera. 792 57

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


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