BACKGROUND Bone marrow erythropoiesis is primarily homeostatic, producing new erythrocytes at a constant rate. However at times of acute anemia, new erythrocytes must be rapidly produced much faster than bone marrow steady state erythropoiesis. At these times stress erythropoiesis predominates. Stress erythropoiesis occurs in the fetal liver during embryogenesis and in the adult spleen and live...

BACKGROUND The technology to recognize nucleated red blood cells (NRBC) automatically has only recently been developed. Modern hematology analyzers allow for rapid and accurate NRBC counts. The goal of our study was to evaluate NRBC counts and the concentrations of serum transferrin receptor (sTfR) in patients affected by different thalassemia syndromes and hereditary spherocytosis. We wished t...

The production of red blood cells, termed erythropoiesis, occurs in two waves in the developing mouse embryo: first primitive erythropoiesis followed by definitive erythropoiesis. In the mouse embryo, both primitive and definitive erythropoiesis originates in the extra-embryonic yolk sac. The definitive wave then migrates to the fetal liver, fetal spleen and fetal bone marrow as these organs fo...

BACKGROUND There are limited reports of thrombosis among myelodysplastic syndrome patients exposed to erythropoiesis stimulating agents. It is not clear whether erythropoiesis stimulating agents are associated with an increased risk of thrombosis in myelodysplastic syndromes, as they are among patients with solid tumors. DESIGN AND METHODS The association between use of erythropoiesis stimula...

Oxygen delivery is essential to sustain all vital functions. Vertebrate organisms have, therefore, evolved sophisticated and tightly regulated mechanisms to ensure continuous red cell synthesis. Chronic or acute blood losses trigger multiple feedback mechanisms aimed at increasing erythropoiesis and minimizing the damage associated with profound anemia and hypoxia. Iron is an element of paramou...

Mouse bone marrow erythropoiesis is homeostatic, whereas after acute anemia, bone morphogenetic protein 4 (BMP4)-dependent stress erythropoiesis develops in the spleen. The aim of this work was to compare spleen stress erythropoiesis and bone marrow erythropoiesis in a mouse model of zymosan-induced generalized inflammation, which induces long-lasting anemia and to evaluate the ability of eryth...

MicroRNAs (miRNAs), a class of small non-coding linear RNAs, have been shown to play a crucial role in erythropoiesis. To evaluate the indispensable role of constant suppression of miR-150 during terminal erythropoiesis, we performed miR-150 gain- and loss-of-function experiments on hemin-induced K562 cells and EPO-induced human CD34+ cells. We found that forced expression of miR-150 suppresses...

Stimulation of erythropoiesis during growth is necessary to ensure proportionality between erythrocyte mass and body mass. However, the way by which erythrocyte formation is adapted to body growth is still unknown. Growth arrest in hypophysectomized rats is accompanied by decreased erythropoiesis. We have, therefore, examined whether insulin-like growth factor I (IGF-I), the mediator of growth ...

BOZZINI, C. E., M. E. BARRIO RENDO, F. C. H. DEVOTO, AND C. E. EPPER. Studies on medullary and extramedullary erythropoiesis in the adult mouse. Am. J. Physiol. 219(3) : 724-728. 1970.Splenic and marrow erythropoiesis was compared in the mouse following stimulation by hypoxia, bleeding, or injections of erythropoietin or depression of erythropoiesis by transfusion. The effect of splenectomy on ...