hematocrit and hence the red cell mass is persistently elevated. After ruling out the presence of spurious polycythemia, attention should be focused on the causes of true polycythemia, namely primary and secondary polycythemias. Primary polycythemias are disorders in which the erythroid progenitors are hypersensitive to very low levels of erythropoietin while secondary polycythaemias are charac...

By ROBERT E. SAGE P ERSISTENT rather than relative and transient polycythemia was first described in 1892 by Vaquez.’ Polycythemia rubra vera is now regarded as one of the myeloproliferative disorders. A slowly progressive neoplasm of unknown etiology involving all cell series of the bone marrow, it is inevitably fatal after a varying period of time.24 The first clinical description of pernicio...

RICHARDSON, TRAVIS Q. AND ARTHUR C. GUYTON. E&xts of polycythemia and anemia on cardiac output and othar circulatory’ factors. Am. J. Physiol. IgT(6): I 167-1170. I g5g.---Normovolemic anemia and polycythemia were studied in 14 dogs. Cardiac outputs increased with anemia and fell with rises in hematocrit. Although many factors-such as chemical changes-may play an important role in these variati...

n engl j med 368;16 nejm.org april 18, 2013 1557 by Barbui et al., a consensus statement of which they are coauthors, contains no data addressing their assertion because, as Barbui has written elsewhere,1 there are no data implicating the baseline leukocyte count as a thrombotic risk factor in patients with polycythemia vera. Fourth, by choosing the reference by Campbell et al., they are confla...

Erythropoietin (EPO) is the principal haematopoietic growth factor of the red blood cell line. Its major role is to stimulate the red blood cell production. EPO synthesis by peritubular cells in the kidney is regulated by oxygen concentration and must lead adaptation of the organism to face many different physiological situations. An imbalance can lead either to anaemia or polycythemia. Synthet...

Thrombosis is one of the major complicafiltration on 4% agarose. Fibrin degradations of polycythemia vera. Seventeen pation products were normal and antitients with polycythemia vera in good thrombin III levels were slightly elevated, hematologic control were evaluated for It appears that patients with polycythemia abnormalities of the coagulation system. vera have chronic activation of the coa...

Spinal arterial vascularization is supplied by a large anastomotic net, making spinal ischemic events far less common than ischemic cerebral strokes. Polycythemia vera, due to blood hyperviscosity and activated platelet aggregation, is associated with a higher risk of arterial and venous thrombotic events. We report a patient with spinal cord transient ischemic attacks, a rarely presenting mani...

JAK2, an acquired mutation of JAK2, is present in a majority of patients with polycythemia vera and to a lesser extent among patients with the other myeloproliferative disorders. We analyzed the effect of JAK2 on the expression of polycythemia rubra vera 1(PRV-1), using an in vitro model. Compared to wild-type JAK2, the presence of JAK2 increased both PRV-1 protein and mRNA levels in murine mye...

Myeloproliferative disorders originate in the clonal expansion of a transformed pluripotential hematopoietic progenitor cell. This results in a group of syndromes that include polycythemia vera, essential thrombocythemia, chronic myelocytic leukemia, and agnogenic myeloid metaplasia. Diagnostic criteria forpolycythemia vera and essential thrombocythemia were codified by the Polycythemia Vera St...