Hematopoietic progenitor cells from different sources have been widely characterized, but their ultrastructural morphology has never been described in detail. In this study, imunomagnetically separated CD34+ cells from normal bone marrow (BM), mobilized peripheral blood (PBSC) and human umbilical cord blood (CB) were studied by transmission electron microscopy (TEM) using a cytochemical method which reveals endogenous myelo-peroxidase (MPO) activity. This technique is particularly suited for detecting early signs of the myeloid commitment. The CD34+ cells from PBSC were morphologically very homogeneous and 94.7 ± 4.5% of these cells were MPO-: these ultrastructural features are generally considered typical of immature cells. The CD34+ BM cells were instead more heterogeneous, with 24.6 ± 7.4% showing intense MPO activity. The ultrastructural characteristics of CB cells fell between those observed in PBSC and BM, but there was a high percentage of morphologically immature cells with no evidence of MPO activity (about 83%). The number of apoptotic cells within samples from different sources was also examined both by TEM and flow cytometry. The percentage of apoptotic cells was 0.7% in PBSC, 2.3% in BM, 2.9% in CB from vaginal delivery and 11.6% in CB from cesarean section. These observations confirm the relative phenotypic immaturity of CB in comparison with BM cells; they also suggest that CB collected after cesarean section may be associated with reduced stem cells viability.
|Titolo:||Ultrastructural features of CD34+ hematopoietic progenitor cells from bone marrow, peripheral blood and umbilical cord blood|
LAMBERTENGHI DELILIERS, GIORGIO (Primo)
SOLIGO, DAVIDE (Ultimo)
|Settore Scientifico Disciplinare:||Settore MED/15 - Malattie del Sangue|
|Data di pubblicazione:||ago-2001|
|Digital Object Identifier (DOI):||10.3109/10428190109099332|
|Appare nelle tipologie:||01 - Articolo su periodico|