As expected, the proportion of GFP+ cells in the total bone marrow, comprised of cells that are rapidly turned over, decreased gradually to ∼1.6% at 12 weeks while the proportion of GFP+ cells in the slowly-dividing HSC population declined only slightly, dropping to only ∼85%.
In this regard, third passage primary FLS cultures established from normal synovial joints of mice carrying green-fluorescent protein (GFP -positive bone marrow comprised approximately 1% of GFP -positive(bone marrow-derived) fibroblast-like comprised8].
This concept has since been further developed, and it is now widely accepted that specific anatomical regions within the bone marrow comprise specialised niches for HSC development and normal blood cell production.
Thus, patients undergoing bone marrow transplantation comprise a group which is at a high risk of systemic infection (approximately 80%) and mortality (approximately 5%) [5] [6].
Interestingly, even after TBI, intrinsically radioresistant stem cells have been detected in distinct bone marrow (BM) areas comprising a residual hematopoietic stem and progenitor cell pool [4].
The hematopoietic stem cells (HSCs) niche of the bone marrow is comprised of HSCs, osteoblasts, endothelial cells and a stromal component of non-hematopoietic multipotent cells of mesenchymal origin named "mesenchymal stem cells" (MSCs).
Although the bone marrow is comprised mainly of CD45+ blood cells we cannot assume that all of the HLA+H2Kd+ hybrid cells are also CD45+.
Cytokeratin-positive cells within the bone marrow may comprise both cancer stem cells and committed progenitors with limited proliferative potential.
Approximately 5000 bone marrow cells, comprising both polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) were scored and the ratios between PCE and NCE were calculated.
The new data have been compiled by the Anthony Nolan bone marrow register, which comprises more than 520,000 people nationwide – and 80,000 in the capital alone.
