摘要:

AbstractGene transfer to hemopoietic cells offers a variety of new approaches to the experimental hematologist as well as potentially providing a means for correcting a number of genetic disorders of humans. From the experimental viewpoint, gene transfer utilizing retroviral vectors introduces new methods for analyzing hemopoietic cell lineages, and the effects of over‐expression of genes affecting hemopoietic cell proliferation and differentiation. The unique properties of retroviral vectors and the optimized methods currently in use to infect hemopoietic cells are represented as a brief review of a rapidly expanding new field of experimental hematolog

ISSN:0737-1454    

DOI:10.1002/stem.5530070502

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

年代:1989

数据来源: WILEY

摘要:

AbstractHemopoiesis is a multistep process involving stem cell renewal, commitment, differentiation, maturation and consequent positioning of the cells within the tissue. Stromal cells are a major component of the hemopoietic microenvironment. The in vitro culture of cloned stromal cells has enabled detailed analysis of their functions and has provided answers relating to the contribution of stromal cells to the control of hemopoiesis. Cultured stromal cells were found to support the renewal of stem cells through a mechanism that did not seem to involve already known cytokines. Cloned stromal cells from both marrow and thymus supported the in vitro accumulation of myeloid as well as T and B lymphoid cells. Thus, cloned stromal cells had the ability to induce multilineage hemopoiesis, irrespective of the organ from which they were derived. Invariably, stromal cells tended to select in culture for hemopoietic cells at early differentiation stages and restricted the accumulation of mature cells. These functions may be part of the mechanism that protects the stem cell pool from excess differentiation.

ISSN:0737-1454    

DOI:10.1002/stem.5530070503

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

年代:1989

数据来源: WILEY

摘要:

AbstractA subline of Brown Norway (BN) acute myelocytic leukemia (AML) which can be propagated in suspension culture (designated IPC‐81) is described. Injection into Lewis x BN F, hybrid (LBN) rats resulted in a log‐linear correlation between tumor cell dose and time till death from the onset of leukemia even after multiple (>16) passages in vitro. An in vitro clonogenic assay for IPC‐81 colony formation (CFU‐leuk) was developed with excellent cloning efficiency (55–82%). Colonies grew without the addition of specific growth factors; syngeneic spleen‐conditioned medium inhibited CFU‐leuk by 40%, but co‐culture with untreated normal LBN rat bone marrow cells had no effect on CFU‐leuk. CFU‐leuk could be detected in the bone marrow 7 to 10 days before morphologic detection of leukemia in injected animals. This cell line should prove useful in the preclinical evaluation of new strategies for treating AML and evaluating new bone mar

ISSN:0737-1454    

DOI:10.1002/stem.5530070504

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe capillary clonogenic cell assay was developed and adapted to culture myeloid and erythroid colonies from human bone marrow cells. The plating efficiencies for femoral bone marrow granulocyte‐macrophage progenitors (CFU‐gm), erythroid colony‐forming units (CFU‐e) and erythroid burst‐forming units (BFU‐e) were 0.143%, 0.229% and 0.141%, respectively. Standard bone marrow progenitor Petri dish assays require a total culture volume of 1 ml per dish, and as such are not suitable for the small numbers of cells often obtained from human bone marrow samples. The microcapillary assay as developed and standardized in our laboratory has the unique advantage of being able to utilize small numbers of cells. This technique is suitable for evaluating the myelotoxicity of investigational new anti‐cancer and anti‐HIV agents and for further investigation of the mechanisms underlying chemotherapy‐induced bon

ISSN:0737-1454    

DOI:10.1002/stem.5530070505

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

年代:1989

数据来源: WILEY

摘要:

AbstractBone marrow samples, from newly diagnosed patients with chronic myeloid leukemia (CML) and normal individuals, were grown in methylcellulose and serially recultured under identical conditions. Specimens derived from normal individuals gave rise to multilineage and megakaryocyte colonies for one to two sequential cultures. Erythroid bursts and granulocyte‐macrophage colonies were observed for three to five sequential cultures. Cultures initiated from samples of patients with CML showed a rapid decline of all types of colonies. Colonies were rarely seen for more than two sequential cultures. When pooled colonies and background cells were recloned separately, secondary colonies were mainly seen in cultures of background cells. This observation is consistent with the view that secondary colonies are more likely to arise from dormant clonogenic progenitors, rather than through cells that have formed primary colonies through a self‐renewal proc

ISSN:0737-1454    

DOI:10.1002/stem.5530070506

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe conventional double‐layer agar method of cloning human tumor cells requires a substantial number of viable tumor cells and 14–21 days of culture. These prerequisites frequently limit its utility as an assay. In an attempt to circumvent these limitations and to reduce the amount of drug that is needed in the assay, we have further developed and miniaturized the assay in which human tumor cells are cloned in glass microcapillary tubes. Cultures consisted of 50 μl containing 15,000 nucleated cells in 975 mm capillary tubes which were incubated for seven days. The results from 50 consecutive tumor biopsies resulted in cloning efficiencies, ranging from 0.007% to 1.0% with an overall successful cloning of 88% of all tumors tested and a good linear growth relationship and chemotherapy sensitivity. This miniaturized assay offers distinct advantages for drug efficacy testing including high cloning efficiencies, small tumor sample and drug requirements, quicker assay turnaround time and a general conservancy of reagents and incubator s

ISSN:0737-1454    

DOI:10.1002/stem.5530070507

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

年代:1989

数据来源: WILEY

ISSN:0737-1454    

DOI:10.1002/stem.5530070501

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

年代:1989

数据来源: WILEY