Linked Life Data

16210411

Source:http://linkedlifedata.com/resource/pubmed/id/16210411

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2005-10-7
pubmed:abstractText
Historically, physicians have attributed delayed platelet engraftment following umbilical cord blood transplant to decreased numbers of stem cells in cord blood compared with adult bone marrow. However, recent studies suggest that delayed platelet engraftment may be caused by an intrinsic inability of neonatal stem cells to produce mature, polyploid megakaryocytes. We tested this hypothesis by transplanting adult bone marrow and newborn liver hematopoietic stem and progenitor cells from transgenic mice expressing green fluorescent protein into myeloablated wild-type recipients and comparing the size and ploidy levels of megakaryocytes that developed in adult transplant recipients. Transplanted stem and progenitor cells, regardless of their source, gave rise to megakaryocytes that were larger than normal adult megakaryocytes as early as 7 days post-transplant. However, megakaryocytes that developed after transplant of neonatal stem and progenitor cells were significantly smaller than those derived from adult stem and progenitor cells. Furthermore, megakaryocytes derived from neonatal cells had lower ploidy values than megakaryocytes derived from adult cells at 18 days post-transplant, when ploidy could first be reliably measured in the bone marrow. These differences in size and ploidy disappeared by 1 month post-transplant. The largest megakaryocytes developed in the spleen. These results suggest that, in the mouse, the microenvironment is responsible for some of the maturational differences in size and ploidy between neonatal and adult megakaryocytes. Furthermore, neonatal and adult megakaryocyte progenitors also have cell-intrinsic differences in the way they engraft and respond to thrombocytopenic stress. These differences may contribute to the delay in platelet engraftment that frequently complicates cord blood transplants.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1066-5099
pubmed:author
pubmed:issnType
Print
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1400-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Developmental differences in megakaryocyte maturation are determined by the microenvironment.
pubmed:affiliation
University of Florida Department of Pediatrics, Gainesville, Florida 32610, USA. slaytwb@peds.ufl.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, N.I.H., Extramural