ISSN:0737-1454    

DOI:10.1002/stem.5530100702

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractStudies in mice have shown that long‐term marrow repopulating cells can be induced to circulate following treatment with cyclophosphamide. These cells can be harvested from the blood of treated mice and used as a transplant to rescue lethally irradiated recipients. The recipients survive and donor‐derived haemopoiesis can be detected months later. This conflicts with the generally accepted idea that The International Journal of Cell Cloning are normally sessile in the bone marrow, are likely to be involved in binding interactions with stromal cells and bind to cultured stroma, and even to plastic, in vitro. It is necessary, therefore, to explain the ability of the The International Journal of Cell Cloning to enter the blood stream following various treatments. One possible explanation is that they do not express the cell adhesion molecules that normally hold them in haemopoietic tissue. If this is true, the reduced CAM expression must be temporary because the circulation of The International Journal of Cell Cloning is ephemeral and because they presumably ‘home’ to the marrow after transpla

ISSN:0737-1454    

DOI:10.1002/stem.5530100703

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:0737-1454    

DOI:10.1002/stem.5530100704

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractQuantitation of spindle‐shaped fibroblastoid CFC in human bone marrow by limiting dilution analysis argues in favor of one type of progenitor. We suggest the existence of 2 functional kinds of spindle‐shaped fibroblastoid cells in regard with their ability to generate fat‐storing cells or express α‐smooth muscle actin. Mechanisms of terminal differentiation Involved are not well understood. We failed to observe any spindle‐shaped fibroblastoid CFC in peripheral blood cythapheresis collected for APBSC, wich suggest that hematopoietic recovery is supported by stromal cells maintained in situ after conditioning and no mobilisation of spindle‐shaped fibroblastoid cell progenitors after

ISSN:0737-1454    

DOI:10.1002/stem.5530100705

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractIf blood or bone marrow mononucleated cells (MNC) from healthy individuals are cultured in semisolid culture medium containing fetal calf serum, low rates of granulo‐monocytic colonies grow out without added hematopoietic growth factors. In contrary, many colonies grow during the recovery phase after stem cell mobilizing treatment with high dose (HD) cytostatics, and in other clinical situations with enhanced hematopoiesis. This functional state is regularly accompanied by transient increase of internal stimulation; it may last for weeks and disappears slowly. Internal stimulation goes along with monocyte activation, as can be observed in adherent cell fractions; cell free supernatants of these monocyte/macrophages contain high colony stimulationg activity. Previous studies onin vitrostimulation by growth factors like GM‐CSF or placental cell conditioned medium have shown that here also monocyte activation is the primary event which entails progenitor stimulation. This suggests that monocyte activation not onlyin vitrotriggers progenitor stimulation, but is also involved in the response of the organism on hematopoietic str

ISSN:0737-1454    

DOI:10.1002/stem.5530100706

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractCD34 monoclonal antibodies recognize a transmembrane phosphoglycoprotein selectively expressed within the lymphohematopoietic system on progenitor and The International Journal of Cell Cloning. The CD34 molecule is heavily glycosylated and strongly negatively charged. Sialic acids contribute to the anomalous electrophoretic mobility corresponding to an apparent molecular weight of ‐110 kilodaltons. However, the molecular weight of the CD34 polypeptide predicted from the sequences of the recently cloned human and murine CD34 genes is only about 40 kilodaltons. The intracellular tail of the CD34 molecule is a substrate for protein kinase C and other protein kinases, suggesting that CD34 plays a role in signal transduction. The highly‐charged N‐terminal extracellular portion of the molecule may mediate intercellular adhesion. The sequence of the CD34 gene is as yet unique, without strong homology to any previously know molecule. To date, the sequence has not provided major clues as to the function of the protein product. The human CD34 gene has been localized to chromosome 1 q32, which is not a frequent breakpoint in hematologic malignancies.Outside the lymphohematopoietic system, CD34 was detected initially only on endothelial cells, although recently an alternatively spliced CD34 isoform with a shortened intracellular tail has been found to be expressed strongly in mouse brain by nucleic acid hybridization. Recent work also suggests that CD34 is expressed on precursors of hematopoietic stromal cells.CD34 monoclonal antibodies are widely used for identification and purification of human lymphohematopoietic progenitor/stem cell populations. The unique selective expression of CD34 on this cell compartment has also stimulated use for successful primate and human “stem cell BMT,” and recent work suggests that this clinical application will be productively expanded to stem cell selection from cord blood and periphe

ISSN:0737-1454    

DOI:10.1002/stem.5530100707

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe average content of MNC fractions in CD34+ cells was found to be 1.16 % in normal bone marrow, (BM; n = 10), 0.90 % in cytapheresis products after mobilization with HD cytostatics (CP; n = 22), and 0.73 % in umbilical cord blood at birth (UB; n = 7). In each group the size of the lineage free subtraction of CD34+ cell was determined by use of the MoAb anti CD38, which is absent in uncommitted early precursors. This minor subpopulation shows differences in all three products (5.8 % in CPvs12 % in UB and 19.4 % in BM). Significant differences exist, if the relative size of subpopulations being committed to the different lineages are compared; for this purpose double immunofluorescence was performed with the MoAb CD71, CD33, CD10 and CD5, which are thought to be lineage specific in hematopoietic cells. The erythroid progenitors were prevalent in CP and UB (80 % and 72.2 %) and lower in BM (43.8 %); also the myeloid marker was more frequent in CP and UB than in BM (68.9 % and 69.1 %vs32.9 %). B‐cell lineage was also more frequent in CP and UB (66.7 % and 77 %) than in BM (32.4 %), as was T‐cell lineage (45.4 % and 42 %vs11.4 %). These results suggest, that circulating hematopoietic cells tend to be committed at a higher degree than those found in bone mar

ISSN:0737-1454    

DOI:10.1002/stem.5530100708

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractTwenty two patients were treated with cyclophosphamide therapy to mobilize progenitors into the blood. Progenitor cells were quantitated in peripheral blood or leukapheresis products using colony assays and flow cytometric measurement of CD34 + cells. Prompt engraftment of>500 granulocytes/ul at a median of 13 days was observed in all patients reconstituted with mobilized cells. In four patients where complete sets of serial samples were obtained, the appearance of CD34+ cells preceded the increase in CFU‐GM by 24 to 48 hours. Peak levels of CD34+ cells ranged from 0.6–5% and coincided with the peak increase in CFU‐GM. Mobilized CD34+ cells were predominantly CD33+, CD13+, CD45R+, CD38+, HLA‐DR+ and CD41+. In contrast to bone marrow CD34+ cells, few mobilized CD34 + cells expressed CD71, CD19 or CD10. Long term culture initiating cells (LTC‐IC), capable of reconstituting hematopoiesis in vitro on irradiated stromal layers, were also measured in serial samples from a single patient with high peak levels of CD34 (∼︁5%). LTC‐IC were present in all samples and the ratio of LTC‐IC to CD34 + cells remained similar throughout the post cyclophosphamide recovery phase. In this patient, preferential mobilization of LTC‐IC earlier in the recovery phase was not observed suggesting that during recovery both primitive and committed progenitors are mobilized together. These data indicate that mobilized CD34+ cells represent subpopulations of CD34+ cells with a myeloid phenotype and that the presence of primitive progenitors among these cells confirms clinical reports that they are capable of long

ISSN:0737-1454    

DOI:10.1002/stem.5530100709

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:0737-1454    

DOI:10.1002/stem.5530100710

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:0737-1454    

DOI:10.1002/stem.5530100711

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY