Accession Number : AD1010635

Title :   Evidence for the Existence of a Bone Marrow Blood Barrier for the Passage of Specific Committed Stem Cells in Human and Canine and Their Physical Separation from Lymphocytes and Pluripotent Stem Cells

Descriptive Note : Technical Report

Corporate Author : Uniformed Services University Of The Health Sciences Bethesda United States

Personal Author(s) : Contreras,Thomas J

Full Text :

Report Date : 12 Nov 1982

Pagination or Media Count : 203

Abstract : The spontaneous presence of hematopoietic stem cells in peripheral blood of mammals has long been recognized. Although present in peripheral blood in small numbers, their existence may be of physiological significance in the maintenance of a hematopoietic homeostasis at sites of blood cell formation distributed throughout skeletal cavities and lymphatic tissues. Transplantations of hematopoietic stem cell collected from peripheral blood are known to reconstitute the bone marrow and lymphatic organs of lethally irradiated animals. However, the characterization of these peripheral blood stem cells and the mode of their selection for migration into peripheral blood from the bone marrow remains to be resolved. To date, the murine bone marrow and circulating stem cells have been better characterized than those of larger mammals. Very recently, it has been postulated that in dogs there is a bone marrow-blood barrier capable of selecting a specific granulocyte/macrophage population of stem cells for migration into blood. This investigation utilizes the principle of counterflow centrifugation elutriation (CCE) for the broader enunciation of this theory in the canine and to postulate a similar theory for humans. CCE was also used for the clean physical separation of pluripotent and committed stem cells obtained from the peripheral blood of dogs. Human subjects were leukapheresed for collection of spontaneously circulating stem cells. Dogs were infused with dextran sulfate for then mobilization of hematopoietic stem cells into peripheral blood and collected for elutriation by the establishment of a leukapheresis procedure for small dogs. The isolation of committed stem cells was monitored by in vitro culture assays and the presence of the pluripotent stem cell was ascertained by the complete hematopoietic reconstitution of lethally irradiated animals.


Distribution Statement : APPROVED FOR PUBLIC RELEASE