Size-selective comparison of fetal calvarial versus adult marrow osteogenic colony-forming entities.
BACKGROUND
This experiment was designed to test whether a single cell suspension of adult marrow-derived cells will form mineralized bone nodules in vitro.


METHODS
At the time of plating, cellular dispersions of either young adult rabbit bone marrow cells or, as controls, of fetal mouse calvarial cells were size-selected by sieving through various pore-size plastic meshes.


RESULTS
When marrow-derived cells were passed through a 105 microns pore-size mesh, fibroblastic cell cultures grew in vitro in six of six attempts; however, marrow cell clusters backwashed off 105 microns pore-size meshes produced osteogenic colonies in vitro in six of six trials. Fetal calvarial cells filtered through a 30 microns pore-size mesh yielded osteogenic nodules in culture in six of six tests.


CONCLUSIONS
For adult bone marrow, cell clumps or clusters larger than 105 microns produced bone colonies under standard cell culture conditions, whereas for fetal calvarial cells, the initiating agent was smaller than 30 microns.
University of California at Los Angeles 90024.
T F
TF
Dutra
G W
GW
Bernard
D000818:Animals; D001854:Bone Marrow Cells; D002469:Cell Separation / Q000379:methods*; D002478:Cells, Cultured; D016922:Cellular Senescence; D005333:Fetus / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology; D008297:Male; D010006:Osteoblasts / Q000166:cytology; D011817:Rabbits; D012886:Skull / Q000166:cytology* / Q000196:embryology*