Hematopoiesis-erythropoiesis

Hemolytic Disease and Ine/fectiVe Erythropoiesis. As discussed previously, Hp levels are a sensitive indicator of in vivo hemolysis, as long as other causes of decreased levels are excluded. Splenomegaly and ineffective hematopoiesis are also associated with decreased levels. The latter, with increased hemolysis of red cells and their precursors in the bone marrow space, is seen in megaloblastic anemias... 

In the later stages of IDA, the Hgb and Hct fall below normal values, and a microcytic, hypochromic anemia develops. Microcytosis may precede hypochromia, as erythropoiesis is programmed to maintain normal Hgb concentration in deference to ceU size. As a consequence, even slightly abnormal Hgb and Hct levels may indicate significant depletion of iron stores and should not be ignored. In terms of RBC indices, MCV reduction occurs earlier in iron-deficient hematopoiesis than reduction in Hgb concentration. 

In early 1987 we proved that the bryostatins were capable of stimulating normal bone marrow progenitor cells to form colonies in vitro and to activate neutrophils (68). Bryostatin 1, e.g., promotes many of the biological effects of GM-CSF and this remarkable activity combined with its antineoplastic activity make it a very attractive clinical candidate. Meanwhile, bryostatins 1 and 2 have found an important role as biochemical probes for unraveling the mechanisms of normal hematopoiesis (69). An important advance here was the observation that bryostatin 1 will stimulate normal erythropoiesis in human bone marrow progenitor assays. Furthermore, bryostatin 1 approximated the stimulatory effects of IL-3 on both murine normal and w/w bone marrow... 

Sakai H, Horinouchi H, Yamamoto M (2006) Acute 40 percent exchange-transfusion with hemoglobin-vesicles (HbV) suspended in recombinant human serum albumin solution degradation of HbV and erythropoiesis in a rat spleen for 2 weeks. Transfusion 46 339-347. Sakai H, Seishi Y, Obata Y et al (2009) Eluid resuscitation with artificial oxygen carriers in hemorrhaged rats profiles of hemoglobin-vesicle degradation and hematopoiesis for 14 days. Shock 31 192-200. 

In man the synthesis of hemoglobin occurs principally in erythroid cells in the bone marrow. In accordance with the generally accepted Unitarian theory of hematopoiesis, primitive stem cells in the bone marrow give rise to cells of the erythroid, myeloid, and platelet series. In erythropoiesis the stem cell differentiates to form the proerythroblast. Successive mitotic divisions yield basophilic, polychromatophilic, and orthochromatic erythroblasts. Subsequent maturation to normoblasts, reticulocytes, and mature erythrocytes involves no further mitotic division. 

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