J Palis

..This surprising finding indicates that the primitive erythroid lineage is indeed mammalian, rather than non-mammalian, in character...

..To review the process of blood-cell formation in the murine and human yolk sac...

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..During the stages analyzed, tal-1 and rbtn2 expression was also present in posterior embryonic mesoderm, while GATA-1 and GATA-2 expression was evident in extraembryonic tissues of ectodermal origin...

..These results also suggest that other growth factor signaling cascades are active during the onset of mammalian erythropoiesis...

..Migration occurred with an optimum dose similar to that found for adult hematopoietic cells and was dependent on the presence of SDF-1 in a gradient. This work suggests roles for chemokine signaling in multiple embryogenic events...

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..The potential functions of ahnak are discussed in light of these results...

..We hypothesize the early expression of insulin in the YS is required for the expansion of insulin responsive cells including primitive erythroblasts...

..Globin switching during ontogeny is due not only to the sequential appearance of primitive and definitive lineages but also to changes in globin expression as primitive erythroblasts mature in the bloodstream...

..This review considers normal B/macrophage cell function in an evolutionary context where a primitive, flexible cell type could perform dual roles in adaptive and innate immunity...

..Our studies establish a new paradigm in the understanding of primitive erythropoiesis and support the concept that primitive erythropoiesis in mice shares many similarities with definitive erythropoiesis of mammals...

..Our findings support the hypothesis that definitive but not primitive hematopoietic progenitors originate from yolk sac-derived HPP-CFC during late gastrulation...

..These findings suggest that EGPx may serve a wider antioxidant role than previously recognized in the interstitium of multiple localized tissues, particularly those associated with the active transport of lipids...

..These data narrow the range of possible mechanisms by which hyperacetylated domains form...

..Continued studies comparing primitive and definitive erythropoiesis will lead to an improved understanding of terminal erythroid maturation...

..We conclude that a functional vascular system develops gradually and that specialized vascular-hematopoietic environments exist after circulation becomes fully established...

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..Thus, Sox6 regulation of epsilony globin might provide a novel therapeutical target in the treatment of hemoglobinopathies such as sickle cell anemia and thalassemia...

..Thus, primitive erythroblasts and essentially all definitive HPCs destined to initially seed the fetal liver after E9.5 are generated in the YS between E7.0-E9.5 and are redistributed into the EP via the systemic circulation...

..Hematologists/oncologists should consider obtaining a serum CK to rule out muscle disease in patients with unexplained elevations of AST, ALT, and LDH...

..These results are consistent with the hypothesis that at E7.5, the yolk sac endoderm provides differentiated liver-like functions, while the newly developing extraembryonic mesoderm is still a largely undifferentiated tissue...

..5 yolk sac and E11.5 liver. Despite this impaired megakaryocyte potential, c-myb-null fetuses had normal platelet numbers at E12.5 but became thrombocytopenic by E15.5, suggesting that c-myb is required for sustained thrombopoiesis...

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..This chapter describes the methodologies for the culture and identification of unipotential and multipotential hematopoietic progenitors in the mouse embryo...

..Continued comparative studies of primitive and definitive erythropoiesis in mammalian and nonmammalian embryos will lead to an improved understanding of terminal erythroid maturation and globin gene regulation...

..The kinetics and ease of scoring this blood-based endpoint suggest that integration into routine toxicology studies will be feasible...

..Scurfy mice and some humans with IPEX are also thrombocytopenic. The purpose of this study was to determine whether the absence of functional Foxp3 leads to defects in megakaryocytes and platelets...

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..These findings indicate that intracellular GSH levels are regulated in a complex fashion during HL-60 cell differentiation, and that transient GSH depletion using low doses of CDNB and DEM enhances the differentiation process...

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..Replating studies demonstrate that hematopoietic progenitors are enriched within FLK1(+)CD4(+) and FLK1(-)CD4(+) cells, while endothelial cells develop from FLK1(+)CD4(+) and FLK1(+)CD4(-) cell populations...

..In situ hybridization revealed an onset of the heartbeat coincident with the appearance of yolk sac-derived erythroblasts in the embryo proper at 5 S. Early maturation of the circulation follows a tightly coordinated program...

..Our results establish a major role for this transcriptional intermediary factor in the differentiation of hematopoietic cells in vertebrates...

..Thus, the trafficking of heme, and not just elemental iron, facilitates erythropoiesis and systemic iron balance...

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..Taken together, these findings demonstrate that cdx4 regulates hox genes and is necessary for the specification of haematopoietic cell fate during vertebrate embryogenesis...

..These findings uncover a connection between haem biosynthesis and Fe-S clusters, indicating that haemoglobin production in the differentiating red cell is regulated through Fe-S cluster assembly...

..These studies will improve our understanding of the causes of anemia and will ultimately lead to curative treatments for children and adults with sickle cell disease and thalassemia syndromes. ..

..A better understanding of the mechanisms responsible for terminal erythroid maturation will ultimately lead to the efficient and complete ex vivo synthesis of erythrocytes to serve an ever-expanding clinical need for red blood cells. ..

..PUBLIC HEALTH STATEMENT: The proposed research is designed to learn which blood cells in the bone marrow are sensitive to radiation and to learn how to protect these cells. ..

..PUBLIC HEALTH STATEMENT: The proposed research is designed to learn which blood cells in the bone marrow are sensitive to radiation and to learn how to protect these cells. ..

..A better understanding of the mechanisms responsible for terminal erythroid maturation will ultimately lead to the efficient and complete ex vivo synthesis of erythrocytes to serve an ever-expanding clinical need for red blood cells. ..

..These studies will improve our understanding of the causes of anemia and will ultimately lead to curative treatments for children and adults with sickle cell disease and thalassemia syndromes. ..

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..A better understanding of the initiation of mammalian hematopoiesis will provide insights into the ontogeny, regulation and expansion of HSCs, as well as the origin of leukemias and bone marrow failure syndromes. ..

..Furthermore, a better understanding of the initiation of mammalian hematopoiesis will provide insights into the origin of hematopoietic stem cells and the development of leukemias and marrow failure syndromes. ..

..This will ultimately lead to improvements in bone marrow transplantation for the curative treatment of congenital anemias, genetic diseases and several forms of childhood and adult cancers. ..

..PUBLIC HEALTH STATEMENT: The proposed research is designed to learn which blood cells in the bone marrow are sensitive to radiation and to learn how to protect these cells. ..