megaloblast


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megaloblast

 [meg´ah-lo-blast″]
a large, nucleated immature progenitor of an abnormal erythrocytic series, an abnormal counterpart to the normoblast; megaloblasts are present in the blood in certain anemias. adj., adj megaloblas´tic.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

meg·a·lo·blast

(meg'ă-lō-blast'),
A large, nucleated, embryonic type of cell that is a precursor of erythrocytes in an abnormal erythropoietic process observed in pernicious anemia; a megaloblasts four stages of development are as follows: 1) promegaloblast, 2) basophilic megaloblast, 3) polychromatic megaloblast, 4) orthochromatic megaloblast.
See also: erythroblast.
[megalo- + G. blastos, + germ, sprout]
Farlex Partner Medical Dictionary © Farlex 2012

megaloblast

(mĕg′ə-lō-blăst′)
n.
An abnormally large nucleated red blood cell found especially in people having pernicious anemia or certain vitamin deficiencies.

meg′a·lo·blas′tic adj.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

megaloblast

An enlarged erythroblast (erythrocyte precursor) with an enlarged nucleus, which arises in a background of vitamin B12 and/or folic acid deficiency and is characterised by asynchronous nucleocytoplasmic development, and manifest by delayed or incomplete nuclear maturation relative to cytoplasmic development; haemoglobinisation proceeds normally, while nuclear maturation slows as the maturation-dependent methyl precursors—usually provided by vitamin B12 and folic acid—are not present.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

meg·a·lo·blast

(meg'ă-lō-blast)
A large, nucleated, embryonic type of cell that is a precursor of erythrocytes in an abnormal erythropoietic process observed in pernicious anemia; a megaloblast's four stages of development are: 1) promegaloblast, 2) basophilic megaloblast, 3) polychromatic megaloblast, and 4) orthochromatic megaloblast.
See also: erythroblast
[megalo- + G. blastos, germ, sprout]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

Megaloblast

A large erythroblast (a red marrow cell that synthesizes hemoglobin).
Mentioned in: Anemias
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Deficiency of either vitamin may lead to a type of anaemia in which large, abnormal red blood cells (megaloblasts) overcrowd in the bone marrow, preventing the production of normal red blood cells.
THE diagnosis requires blood tests to look for megaloblasts in your blood and possibly in your bone marrow too, and to measure your levels of vitamin B12 and folic acid.
Bone marrow aspiration was hypercellular and contains RBC precursors called megaloblasts and hypersegmented megakaryocytes.
Once the patients were selected, various hematological parameters including peripheral smear analysis for megaloblasts, macrocytes, hypersegmented neutrophils and RBC indices were carried out.
Megaloblasts are large cells with an increased nuclear/cytoplasmic ratio in which nuclear maturation is delayed, while cytoplasmic maturation is more advanced.