Biomedical subjects

M Y Gordon

Publications and source records attributed to M Y Gordon.

At least 109 records · Page 6Linked to original sources

PubMed1987

Characterisation of stroma-dependent blast colony-forming cells in human marrow.

Human bone marrow contains a population of haemopoietic progenitor cells that can be distinguished by their ability to adhere to preformed stromal layers (cultured in the presence of methylprednisolone [MP+] and form blast cell colonies. The stromal layers function in the colony assay after they have been heavily irradiated but not after they have been passaged. The binding of the progenitor cells to the stromal cells is complete after 2 hours of coincubation, and stromal layers of 9.6 cm2 can provide adhesion sites for at least 2,000 blast colony-forming cells. The blast colony-forming cells were shown by micromanipulation to self-renew as well as to give rise to multipotential and lineage-committed colony-forming progenitor cells.

Bone Marrow Cells↗

PubMed1987

Expression of HPCA-1 and HLA-DR antigens on growth factor- and stroma-dependent colony forming cells.

The expression of HLA-DR and HPCA-1 antigens (recognized by the L243 and BI.3C5 antibodies respectively) on adult human bone marrow cells was examined by fluorescence activated cell sorting and colony assays. Nearly all the (day 14) lineage restricted and multipotential colony forming cells analysed in methylcellulose cultures in the presence of added growth factors express HLA-DR and HPCA-1 determinants. Two colour cell sorting reveals that the lineage restricted HLA-DR positive progenitors express variable levels of BI.3C5 positivity whereas most of the multipotential progenitors, the multi-CFC or CFU-GEMM, are highly BI.3C5 positive. The isolated HLA-DR and BI.3C5 positive populations also contain haemopoietic precursors which adhere to and form colonies on pre-formed stromal layers. Thus, haemopoietic progenitors assayed in both types of culture system can be analysed and enriched by simultaneous two-colour sorting using anti-HLA-DR and BI.3C5 monoclonal antibodies. Similarities in the antigenic phenotype of such cells, however, precludes the use of these reagents for segregating growth factor-dependent from stroma-dependent progenitors.

Adult↗

PubMed1987

Plastic-adherent progenitor cells in human bone marrow.

Human bone marrow contains plastic-adherent hemopoietic progenitor cells whose plating efficiency is increased by brief (2 h) exposure to methylprednisolone (MP). When subsequently covered with methylcellulose medium, they form colonies of monoblastoid cells. Colony size, but not number, and mature cell production are increased by erythropoietin (epo) and granulocyte-macrophage colony-stimulating factor (GM-CSF). However, colonies do not grow under serum-free conditions. The resistance of plastic-adherent progenitors to treatment with 5-fluorouracil (5FU), their growth pattern, and their capacity to produce granulocytic and erythroid colonies on replating, suggest that they may be similar to the primitive, 5FU-resistant, plastic-adherent progenitor cells (HPP-CFC) in murine marrow.

Bone Marrow Cells↗

PubMed1987

Characterization of cultured stromal layers derived from fetal and adult hemopoietic tissues.

Cultured stromal layers grown from fetal and adult hemopoietic tissues reproduce, in vitro, features that typify their in vivo counterparts. Thus, fetal liver (FL) cultures consist predominantly of macrophages, and fetal bone marrow (FBM) cultures fail to form the fat cells that are characteristic of adult bone marrow (ABM) cells grown in the presence of methylprednisolone. Further investigation showed that the lack of fat cell formation in FBM cultures was not due to absence of steroid receptors because cells from the fibroblast component of FBM and ABM possess similar numbers of receptors of similar affinities. Phenotypically, the macrophages that occur in FL, FBM, and ABM stromal cultures are RFD7+, 3.9+ UCHM1, which identifies them as mature tissue macrophages. Also, they express HLA-DR, indicating an activated state and a potential for participating in hemopoietic cell regulation, at least in vitro. Functionally, stromal layers grown from adult bone marrow provide feeder layers for blast colony-forming cells (Bl-CFC). These Bl-CFC adhere to ABM stromal cells but not to FBM or stromal cells.

Adipose Tissue↗

PubMed1986

Primitive progenitor cells in the blood of patients with chronic granulocytic leukemia.

We measured the number of blast colony-forming cells (Bl-CFC) in the blood of 11 patients with untreated chronic granulocytic leukemia (CGL). The culture system used detects three types of Bl-CFC (Types I, II and III) in normal marrow, of which Bl-CFC (I) are the most primitive and might represent the putative hemopoietic stem cell. The mean numbers of Bl-CFC (I) in CGL blood, normal bone marrow and normal blood were 134 +/- 29 (+/- SEM), 127 +/- 21 and 1.5 +/- 0 respectively per 1 X 10(6) mononuclear cells. These findings are consistent with the concept that CGL is due to a primary increase in stem cell numbers with secondary increases in committed progenitor and leukocyte numbers.

Adolescent↗

PubMed1985

4-Hydroperoxycyclophosphamide inhibits proliferation by human granulocyte-macrophage colony-forming cells (GM-CFC) but spares more primitive progenitor cells.

Despite its considerable toxicity to haemopoietic colony-forming cells, 4-hydroperoxycyclophosphamide (4-HC) has successfully been used to purge marrow of leukaemic cells before it is used to rescue patients from high-dose chemoradiotherapy. These conflicting observations indicate that haemopoietic progenitor cells that are not detected by the established colony-forming assays survive exposure to 4-HC and repopulate the marrow. The recent finding that murine spleen colony-forming cells (CFU-S) are resistant to 4-HC [Porcellini A, et al. (1983) Expl Hemat. 11 (suppl 14) 331 (abstract)] [14] also indicates that sensitivity to 4-HC can be used to distinguish primitive progenitor cells from committed progenitor cells. As part of a study on the nature of a population of blast colony-forming cells in human bone marrow, we tested their sensitivity to 4-HC to see whether they also are spared by the drug. We found that 4-HC had much less effect on the blast colony-forming cells than on the granulocyte-macrophage colony-forming cells (GM-CFC). This result suggests that the blast-colony-forming cells may be early human haemopoietic progenitor cells.

Anemia, Aplastic↗

PubMed1985

Colony formation by primitive haemopoietic progenitors in cocultures of bone marrow cells and stromal cells.

Human bone marrow contains a class of human haemopoietic progenitor cells that adhere to cultured marrow stromal cells and form colonies of blast cells. These progenitor cells are found in the non-adherent mononuclear fraction of normal human bone marrow. They are not in active cell cycle and do not express Ia-like (HLA-DR) antigens but appear to be capable of self-renewal in vitro. These properties indicate that they should be classified as members of the primitive haemopoietic progenitor cell compartment.

Bone Marrow Cells↗

PubMed1985

Separation of human blast progenitors from granulocytic, erythroid, megakaryocytic, and mixed colony-forming cells by "panning" on cultured marrow-derived stromal layers.

Primitive myeloid progenitor cells will adhere to stromal feeder layers of human bone-marrow-derived adherent cells grown in the presence of methylprednisolone (MP+ layers). These progenitors form colonies of blast cells on the MP+ stromal layers, but not on stromal layers grown in the absence of MP (MP- layers). The present study was designed to determine whether this failure of colony formation was caused by inability of the progenitors to adhere to the MP- layers or inability to proliferate in their presence. We also compared the capacities of the blast progenitors to adhere to MP+ and MP- stromal cells with those of mixed (GEMM-CFC), erythroid (BFU-E), megakaryocytic (Mk-CFC), and granulocyte-macrophage (GM-CFC) colony-forming cells. Incubation of bone marrow mononuclear cells with MP+ stromal layers removed 90% of the blast progenitors, but did not remove the majority of the GEMM-CFC, BFU-E, Mk-CFC, and GM-CFC; incubation of bone marrow mononuclear cells with MP- stromal layers did not remove the blast progenitors or the GEMM-CFC, BFU-E, Mk-CFC, and GM-CFC. Thus, the blast progenitors adhere to MP+ stromal feeder layers, but not to MP- stromal layers. In this respect they differ from the other more mature colony-forming cells that do not show any marked tendency to adhere to either type of stromal layer.

Bone Marrow Cells↗

PubMed1984

Comparison of mesna with forced diuresis to prevent cyclophosphamide induced haemorrhagic cystitis in marrow transplantation: a prospective randomised study.

A prospective randomised study was carried out to compare the effect of mesna (2-mercaptoethane sulphonate sodium) with that of forced diuresis in preventing cyclophosphamide induced haemorrhagic cystitis in marrow transplant recipients. Sixty-one consecutive BMT recipients were randomised for treatment with forced diuresis or mesna. The incidence of macroscopic haematuria was significantly lower in the mesna treated group (chi 2 = 4.03, P less than 0.05). No specific side effects of mesna were detected. The lymphopenia induced by cyclophosphamide in the aplastic recipients was similar in the mesna and forced diuresis groups suggesting that mesna has no effect on the lymphocytotoxic activity of cyclophosphamide, although 6 out of 7 episodes of graft failure documented in the study occurred in mesna treated patients. As a result of this study our present policy is to use mesna in all BMT recipients but to continue careful documentation of the incidence of graft failure.

Adolescent↗

PubMed1984

Comparisons of the composition of fat cells obtained from the marrow of normal individuals or of subjects with aplastic anemia and from bone marrow cultures.

The lipid composition of fat cells in the bone marrow of normal individuals and patients with aplastic anemia was investigated, using thin-layer and gas-liquid chromatography. The results were compared to those obtained from fat cells grown in vitro. Thin-layer chromatography (t.l.c) revealed that triacylglycerols were the major component of normal and aplastic marrow fat cells and of fat cells in culture. Analysis by gas-liquid chromatography (g.l.c) of the triacylglycerols, diacylglycerols, and nonesterified fatty acids detected minor differences between fat cells from normal and aplastic marrow. Although there were no statistically significant differences in the proportions of saturated fatty acids and their unsaturated analogues, the relative amounts of gamma-linolenic acid were increased in aplastic anemia and those of linoleic and myristoleic acids were reduced. In contrast, fat cells obtained from in vitro cultures contained a much higher proportion of unsaturated fatty acids. These findings indicate that there is no marked abnormality in the composition of bone marrow fat cells in aplastic anemia, but that minor differences can be detected; the fatty acid composition of bone marrow fat cells is not reproduced in vitro.

Adipose Tissue↗

PubMed1983

Spatial and functional relationships between human hemopoietic and marrow stromal cells in vitro.

The aims of the present study were to determine which stromal elements are important for the proliferation of human hemopoietic precursor cells in vitro and to develop a model for human bone marrow transplantation. First, we incubated bone marrow mononuclear cells in liquid culture under different conditions to obtain different proportions of fibroblasts, fat cells, and macrophages. We also looked for persistent hemopoiesis in association with these stromal cells. Second, we seeded nonadherent bone marrow mononuclear cells onto established stromal monolayers by incubating them together for 2 h and then washed off the unattached cells. The cells remaining on the monolayer were then stimulated by granulocyte-macrophage colony-stimulating activity (GM-CSA). We found that persistent hemopoiesis was maintained only in the presence of fibroblasts, fat cells, and macrophages. We also found that hemopoietic precursor cells attached to monolayers containing fibroblasts and fat cells, but not to monolayers containing fibroblasts or macrophages alone. Therefore, fibroblasts, fat cells, and macrophages appear to be necessary for the maintenance of human hemopoiesis in vitro, and fat cells may permit repopulation of marrow stroma by transplanted hemopoietic stem cells. This in vitro model might reflect features of human bone marrow transplantation in vivo.

Bone Marrow Cells↗

PubMed1983

Effects of human marrow stromal cells on proliferation by human granulocytic (GM-CFC), erythroid (BFU-E) and mixed (Mix-CFC) colony-forming cells.

We have investigated the effects of the major components of bone marrow stroma (fibroblasts, fat cells, macrophages and endothelial cells) on colony-forming haemopoietic precursor cells. Selective cultures of the different stromal cell types, grown to confluence, were used as underlayers for agar or methylcellulose cultures containing bone marrow cells. In different experiments, colony-stimulating factor (CSF) was added to stimulated granulocyte-macrophage colony-forming cells (GM-CFC), erythropoietin was used to induce erythroid burst (BFU-E) formation or erythropoietin and medium conditioned by leucocytes in the presence of phytohaemagglutinin (PHA-LCM) was added to induce the formation of colonies of mixed myeloid lineage (Mix-CFC). Fibroblasts grown from human marrow enhanced granulopoiesis when CSF was present in the cultures but suppressed the formation of BFU-E and mixed colonies. Treatment of the cultures with methylprednisolone induced the formation of fat cells in the fibroblast cultures and prevented both the fibroblast-mediated enhancement of granulopoiesis and the fibroblast-mediated suppression of erythropoiesis. Stromal macrophages reduced granulocyte colony formation but had little effect on the proliferation of BFU-E or mixed colony-forming cells. Endothelial cells stimulated granulopoiesis by releasing CSF into the culture supernatant; supernatant from endothelial cell cultures had no marked effects on either BFU-E or Mix-CFC. We conclude that different components of marrow stroma have contrasting effects on erythropoiesis and granulopoiesis; thus, marrow stroma may regulate the expression of stem cell differentiation in vivo.

Bone Marrow Cells↗

PubMed1983

Bone marrow fibroblast function in relation to granulopoiesis in aplastic anaemia.

Fibroblasts grown from the bone marrow of normal individuals and incubated with colony-stimulating factor (CSF) enhance the stimulating activity of this CSF on granulocyte-macrophage colony-forming cell (GM-CFC) proliferation. For this study, the ability of fibroblast monolayers grown from the marrows of six patients with severe aplastic anaemia to increase the activity of CSF has been compared with the activity of normal fibroblasts. Tests of this function showed subnormal CSF-enhancing activity by fibroblasts grown from the marrows of three of the six aplastic patients. Since cultured bone marrow fibroblasts are thought to represent an important component of the haemopoietic microenvironment, the results suggest that some of the patients had a microenvironmental abnormality at the time of study. One of the patients whose fibroblasts were abnormal was reinvestigated after he had been given a graft of allogeneic bone marrow cells. His post-graft fibroblast function was normal, showing that the abnormality was reversible.

Adolescent↗

PubMed1982

Human marrow stromal cells in culture: changes induced by T-lymphocytes.

Suspension cultures of human bone marrow mononuclear cells form colonies of fibroblastoid cells which expand to form confluent monolayers. These fibroblastoid cells are thought to represent elements of the bone marrow stroma. Fibroblastoid cells failed to proliferate when the cultures were initiated and maintained in the presence of 50% (v/v) of medium conditioned by phytohaemagglutinin (PHA)-stimulated blood mononuclear cells or supernatant media from one-way mixed lymphocyte reactions (MLR). Under these conditions, the cultures contained a pleomorphic population of macrophage-like cells. Some of the characteristics of the fibroblastoid and macrophage-like cells have been compared and a separate origin of the two cell types has been demonstrated. Further experiments indicated that T lymphocytes were the source of the factor(s) in the conditioned media which was responsible for the growth of the macrophage-like cells at the expense of the fibroblastoid cells and suggested that activation of the T cells was necessary for them to exert their effect. The results support the idea that T lymphocytes can influence the haemopoietic microenvironment of the bone marrow.

Bone Marrow Cells↗

PubMed1982

Regulation of granulocyte and macrophage colony-stimulating factor production by phytohaemagglutinin-treated blood mononuclear cells.

The colony-stimulating activity (CSA) of medium conditioned by phytohaemagglutinin (PHA)-stimulated blood mononuclear cells was tested using granulocyte-macrophage colony-forming cells (GM-CFC) from normal bone marrow. Low concentrations of the conditioned medium stimulated granulocytic colony-forming cells (CFC) which formed colonies by the seventh day of incubation; higher concentrations stimulated the formation of macrophage colonies which were not seen until the end of the second week in culture. The colony-stimulating activities could not be demonstrated in adherent cell-depleted bone marrow cultures. This dependence of activity on adherent cells was confirmed by incubating different concentrations of conditioned medium with isolated adherent cells and then testing for colony-stimulating activity in cultures of non-adherent bone marrow cells. The activities of conditioned media following exposure to adherent cells corresponded to the results seen when the conditioned medium from PHA-stimulated mononuclear cell cultures was used to stimulate agar cultures of unseparated marrow. The results suggest that PHA-responsive mononuclear cells (probably T lymphocytes) may modulate the regulation of colony-stimulating factor (CSF) production by adherent colony-stimulating cells (CSC).

Cell Adhesion↗

PubMed1982

Granulopoietic effects of factors produced by cultured human bone marrow fibroblastoid cells.

The functional relationships between bone marrow fibroblastoid cells, granulocyte-macrophage colony-forming cells (GM-CFC) and colony-stimulating factor (CSF) have been investigated in vitro. Cultured fibroblastoid cells neither produce CSF nor release a factor which increases the production of CSF by plastic-adherent colony-stimulating cells (CSC). However, the presence of fibroblastoid cells in agar cultures containing performed CSF increases the plating efficiency of GM-CFC. The fibroblastoid cells seem to act either by increasing the stimulatory activity of CSF or by releasing a stimulatory factor in the presence of CSF. The sensitivity of the colony-forming cells to CSF was not modified by contact with the fibroblastoid stromal cells. Fibroblastoid cells themselves were required for demonstration of the enhancement of CSF since the effect could not be reproduced using supernatant medium from fibroblast cultures. Different effects were seen when supernatant media from fibroblastoid cultures were incorporated into agar cultures of GM-CFC or into liquid cultures of bone marrow cells. The culture supernatants contain soluble factors which inhibit the formation of granulocyte-macrophage colonies in CSF-stimulated agar cultures and activities which increase the survival of GM-CFC in liquid cultures. The results suggest that stable long-range and transient short-range influences of bone marrow fibroblastoid cells may be involved in the regulation of granulopoiesis.

Bone Marrow Cells↗

PubMed1981

Environmental factors in haemopoietic failure in humans.

Aplastic anaemia can be defined as pancytopenia in the presence of a hypoplastic bone marrow and in the absence of leukaemia or malignant infiltration. Most cases have been attributed to an intrinsic defect in the pluripotential haemopoietic stem cell; however, stem cell suppression or a defect in the marrow environment would also produce the symptoms of aplasia. In vitro culture systems have been used to explore these possibilities and have provided evidence that the syndrome known as aplastic anaemia includes several distinct disease processes. These include primary failure of the haemopoietic stem cell and the suppression of stem cell function by cellular, humoral or other environmental factors. This heterogeneity provides the background for attempting to treat the disease by bone marrow transplantation, immunosuppression or stimulation of haemopoiesis.

Anemia, Aplastic↗

PubMed1981

The combination of melphalan with prednisolone. Anti-tumor effect and normal tissue toxicity in laboratory systems.

The effect of prednisolone upon the therapeutic index of melphalan has been studied in a variety of laboratory systems. The anti-tumour action of melphalan was assessed for a human melanoma xenograft growing in immune-deprived mice, clonogenic cell survival and tumour growth delay being used as end-points. Normal tissue toxicity was assessed for human bone marrow colony-forming units, murine bone marrow colony-forming units, murine gastrointestinal crypt microcolony-forming cells, and mouse survival. Prednisolone had no anti-tumour effect when given alone, but increased the anti-tumour effect of melphalan significantly. No increase in the toxicity of melphalan to marrow or gut colony-forming cells could be demonstrated. However, mouse survival was significantly lower after treatment with the combination than with melphalan alone. This study supports the view that steroids may enhance the anti-tumour effect of some alkylating agents, but this may be at the expense of increased normal tissue toxicity in some circumstances.

Animals↗