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Erythroid Precursors (erythroid + precursor)

Distribution by Scientific Domains

Medical Sciences	77%
Life Sciences	22%

Terms modified by Erythroid Precursors

erythroid precursor cell

Selected Abstracts

Leukemia-related transcription factor TEL/ETV6 expands erythroid precursors and stimulates hemoglobin synthesis

CANCER SCIENCE, Issue 4 2009
Minenori Eguchi-Ishimae
TEL/ETV6 located at chromosome 12p13 encodes a member of the E26 transformation-specific family of transcription factors. TEL is known to be rearranged in a variety of leukemias and solid tumors resulting in the formation of oncogenic chimeric protein. Tel is essential for maintaining hematopoietic stem cells in the bone marrow. To understand the role of TEL in erythropoiesis, we generated transgenic mice expressing human TEL under the control of Gata1 promoter that is activated during the course of the erythroid-lineage differentiation (GATA1-TEL transgenic mice). Although GATA1-TEL transgenic mice appeared healthy up to 18 months of age, the level of hemoglobin was higher in transgenic mice compared to non-transgenic littermates. In addition, CD71+/TER119+ and c-kit+/CD41+ populations proliferated with a higher frequency in transgenic mice when bone marrow cells were cultured in the presence of erythropoietin and thrombopoietin, respectively. In transgenic mice, enhanced expression of Alas-e and ,-major globin genes was observed in erythroid-committed cells. When embryonic stem cells expressing human TEL under the same Gata1 promoter were differentiated into hematopoietic cells, immature erythroid precursor increased better compared to controls as judged from the numbers of burst-forming unit of erythrocytes. Our findings suggest some roles of TEL in expanding erythroid precursors and accumulating hemoglobin. (Cancer Sci 2009; 100: 689,697) [source]

Bone marrow cells from myelodysplastic syndromes show altered immunophenotypic profiles that may contribute to the diagnosis and prognostic stratification of the disease: A pilot study on a series of 56 patients,

CYTOMETRY, Issue 3 2010
Sergio Matarraz
Abstract A heterogeneous spectrum of immunophenotypic abnormalities have been reported in myelodysplastic syndromes (MDS). However, most studies are restricted to the analysis of CD34+ cells and/or other major subsets of CD34, cells, frequently not exploring the diagnostic and prognostic impact of immunophenotyping. Methods: We propose for the first time an immunophenotypic score (IS) based on the altered distribution and immunophenotypic features of maturing/mature compartments of bone marrow (BM) hematopoietic cells in 56 patients with MDS that could contribute to a refined diagnosis and prognostic evaluation of the disease. Results: Although MDS-associated phenotypes were detected in reactive BM, the overall immunophenotypic profile of BM cells allowed an efficient discrimination between MDS and both normal and reactive BM, once the number and degree of severity of the abnormalities detected per patient were simultaneously considered in the proposed IS. Interestingly, increasingly higher IS were found among patients with MDS showing adverse prognostic factors and in low- versus high-grade cases. The most informative prognostic factors included the number of CD34+ cells, presence of aberrant CD34,/CD117+ precursors, decreased mature neutrophils and CD34, erythroid precursors, and increased numbers of CD36,/lo erythroid precursors; in addition, the IS was an independent prognostic factor for overall survival. Conclusions: Assessment of immunophenotypic abnormalities of maturing/mature BM cells allows an efficient discrimination between MDS and both normal and reactive BM, once the number and degree of severity of the abnormalities detected are simultaneously scored. Interestingly, progressively higher IS were found among patients with MDS with adverse prognostic features and shorter overall survival. © 2010 Clinical Cytometry Society [source]

Identification of erythroid-enriched gene expression in the mouse embryonic yolk sac using microdissected cells

DEVELOPMENTAL DYNAMICS, Issue 2 2008
Latasha C. Redmond
Abstract Little is known about the genes that control the embryonic erythroid program. Laser capture microdissection was used to isolate primitive erythroid precursors and epithelial cells from frozen sections of the embryonic day 9.5 yolk sac. The RNA samples were amplified and labeled for hybridization to Affymetrix GeneChip Mouse Genome 430A 2.0 arrays. Ninety-one genes are expressed significantly higher in erythroid than in epithelial cells. Ingenuity pathway analysis indicates that many of these erythroid-enriched genes cluster in highly significant biological networks. One of these networks contains RBTN2/LMO2, SCL/TAL1, and EKLF/KLF1, three of the very few genes required for primitive erythropoiesis. Quantitative real-time polymerase chain reaction was used to verify that platelet factor 4, reelin, thrombospondin - 1, and muscleblind - like 1 mRNA is erythroid-enriched. These genes have established roles in development or differentiation in other systems, and are, therefore, good candidates for regulating primitive erythropoiesis. These results provide a catalog of genes expressed during primitive erythropoiesis. Developmental Dynamics 237:436,446, 2008. © 2008 Wiley-Liss, Inc. [source]

Erythropoietin-induced, antibody-mediated pure red cell aplasia,

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2005
The Pure Red Cell Aplasia Global Scientific Advisory Board (GSAB)
Abstract Pure red cell aplasia (PRCA) is a rare haematological condition that is characterized by severe aregenerative anaemia due to an almost complete cessation of red blood cell production. While antibody-mediated PRCA was extremely rare before 1998, the incidence of this disorder increased sharply after 1998 in patients receiving subcutaneous epoetin alfa produced by Ortho-Biotech and marketed outside the USA. The diagnosis of antibody-mediated PRCA relies mostly on the results of bone marrow biopsy or aspirate, which shows an absence of erythroid precursors and/or red cell maturation arrest while counts of white cell and platelet precursors are normal, and on the identification of circulating anti-erythropoietin antibodies. Retrospective analysis of PRCA cases has shown that immunosuppressive therapy can induce a disappearance of anti-erythropoietin antibodies in most patients. [source]

Pregnancy outcome in congenital dyserythropoietic anemia type I

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 4 2008
Hanna Shalev
Abstract Objectives:, Congenital dyserythropoietic anemia type I (CDA I) is a rare inherited disease characterized by moderate to severe macrocytic anemia and abnormal erythroid precursors with nuclear chromatin bridges and spongy heterochromatin. Moderate to severe maternal anemia is a recognized independent risk factor for low birth weight (LBW) and complicated delivery. The aim of the study was to review the outcome of pregnancies in women with CDA I. Methods:, The clinical and laboratory records of 28 spontaneous pregnancies in six Bedouin women with CDA I were reviewed. The results were compared with findings from a retrospective review of a large population-based registry including all pregnancies in Bedouin women during the same 15-yr period. Results:, Eighteen pregnancies in women with CDA I (64%) were complicated. One pregnancy was aborted spontaneously in the first trimester and one resulted in a non-viable fetus (stillborn at 26 wk). Cesarean section (CS) was performed in 10 pregnancies (36%). Eleven of the 26 newborns (42%) had a LBW: six were born prematurely and five were small for gestational age. The odds ratio for CS in women with CDA I compared with healthy Bedouin women was 4.5 [95% confidence interval (CI) 1.2,10.3], and for a LBW infant, 5.5 (95% CI 2.4,12.3). Careful follow-up was associated with significantly better fetal outcome (P = 0.05). Conclusions:, Pregnancies in women with CDA I are at high risk for delivery-related and outcome complications. To improve fetal outcome, women with CDA I should be carefully monitored during pregnancy. [source]

A novel mutation in the last exon of ATRX in a patient with , -thalassemia myelodysplastic syndrome

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2006
Daniel B. Costa
Abstract:, We describe a patient with acquired alpha-thalassemia myelodysplastic syndrome (ATMDS). A previously healthy 66-year-old man presented with hemoglobin of 9.3 g/dL, mean corpuscular volume 59 fL, and a bone marrow aspirate with increased erythroid precursors and hypolobulated megakaryocytes. Hemoglobin H inclusions were seen in most red cells after 1% brilliant cresyl blue supravital stain of the peripheral blood. At the molecular level, we identified of a novel mutation in the most 3, exon of the ATRX gene (CGA,TGA substitution in codon 2407) resulting in a premature termination codon (p.R2407X). This case provides further evidence for a link between ATRX mutations and ATMDS, and suggests a possible role for the conserved Q-box element in ATRX function. [source]

Two-phase liquid culture system models normal human adult erythropoiesis at the molecular level

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2000
Sharon H. Pope
Abstract: We have studied the patterns of expression of various genes during maturation of normal human adult erythroid precursors cultured in a two-phase liquid culture method. In the first phase, peripheral blood mononuclear cells are cultured for one week in the presence of a combination of growth factors, but not erythropoietin (Epo). In Phase II, Epo is included in the medium. Cell samples were taken throughout phase II, and expression of globins, transcription factors, and cytokine receptors was assayed by RT-PCR and quantified by phosphor imaging. We have divided phase II into stages: early (days 0,5), intermediate (days 6,10) and late (days 11,15) and measured maximum expression of each gene. During early phase II, ,-globin, Sp1, and GATA-2 mRNAs were expressed at their highest levels. As the cells matured during the intermediate period, GATA-2 levels remained high, and then declined, while the transcription factors GATA-1, EKLF, NF-E2, and the Epo receptor (EpoR) reached maximum expression. In late phase II, ,-globin increased and reached its maximum level of expression. This erythroid culture system appears to recapitulate normal adult erythropoiesis at the molecular level, and thus may be a suitable model to examine the molecular basis of severe congenital or acquired disorders oferythropoiesis. [source]