Deregulated expression of microRNAs is associated with neoplasia. Here, we show that mature miR-16 levels are abnormally increased in CD34(+) cells of patients with polycythemia vera as a consequence of preferential expression of miR-16-2 on chromosome 3 rather than of miR-16-1 on chromosome 13. Forced expression of miRNA-16 in normal CD34(+) cells stimulated erythroid cell proliferation and ma...

Activating mutations leading to ligand-independent signaling of the stem cell factor receptor KIT are associated with several hematopoietic malignancies. One of the most common alterations is the D816V mutation. In this study, we characterized mice, which conditionally express the humanized KITD816V receptor in the adult hematopoietic system to determine the pathological consequences of unrestr...

To further characterize JAK2 exon 12 mutations, we performed molecular screening in 409 patients with polycythemia vera or unclear erythrocytosis with unmutated JAK2V617. The frequency of JAK2exon12 mutations was 10/63 (15.9%) in PV but only 5/346 (1.4%) in the erythrocytosis cases. Nine different mutations including four new types (D544-L545del, H538DK539LI540S, H538-K539del, V536-F547dup) wer...

In this paper we describe a patient with polycythemia vera (PV), who presented with hypercalcemia due to a parathyroid adenoma. In November 1999, the patient was admitted to our hospital with meteorism and constipation. Her physical examination revealed plethora and hepatosplenomegaly. Laboratory data revealed hyperparathyroidism in addition to PV: Rbc 8 x 10(6)/mm3, Hct 63.7%, serum calcium 13...

BACKGROUND The use of aspirin for the prevention of thrombotic complications in polycythemia vera is controversial. METHODS We enrolled 518 patients with polycythemia vera, no clear indication for aspirin treatment, and no contraindication to such treatment in a double-blind, placebo-controlled, randomized trial to assess the safety and efficacy of prophylaxis with low-dose aspirin (100 mg da...

INTRODUCTION Patients with polycythemia vera are at high risk for vaso-occlusive events including cerebral ischemia. Although unusual, acute ischemic stroke may be an initial presentation of polycythemia vera. It had been previously assumed that cerebral ischemic events were due to increased blood viscosity and platelet activation within the central nervous system arterial vessels. However, the...

We tested the hypothesis that levels of pentraxin high sensitivity C-reactive protein and pentraxin 3 might be correlated with cardiovascular complications in patients with essential thrombocythemia and polycythemia vera. High sensitivity C-reactive protein and pentraxin 3 were measured in 244 consecutive essential thrombocythemia and polycythemia vera patients in whom, after a median follow up...

SSOCIATED PROLIFERATION of the various hematologic elements in the marrow, although recognized for some time,2 has recently been the subject of renewed interest.3’8 A close relationship between myelofibrosis and he leukoerythroblastic conditions was demonstrated by Vaughan and HarrisonT in 1939. They suggested that an unknown stimulus acting on the primitive mesenchymal reticulum cell may be re...

SSOCIATED PROLIFERATION of the various hematologic elements in the marrow, although recognized for some time,2 has recently been the subject of renewed interest.3’8 A close relationship between myelofibrosis and he leukoerythroblastic conditions was demonstrated by Vaughan and HarrisonT in 1939. They suggested that an unknown stimulus acting on the primitive mesenchymal reticulum cell may be re...

serum calcium accompanying a fall in red blood cell count following treatment with phenylhydrazine. We were stimulated by this report to make some additional studies of the calcium metabolism in polycythemia, but the work was halted in its incipiency by our inability to confirm the findings of Brown and Roth. Serum calcium determinations were made in nine cases of typical polycythemia vera usin...