Biomedical subjects

H Ema

Publications and source records attributed to H Ema.

23 records · Page 2Linked to original sources

PubMed1990

Colony formation of clone-sorted human hematopoietic progenitors.

To characterize human hematopoietic progenitors, we performed methylcellulose cultures of single cells isolated from a population of CD34+ cells by fluorescence-activated cell-sorting (FACS) clone-sorting system. CD34+ cells were detected in bone marrow (BM) and peripheral blood (PB) cells at incidences of 1.0% and 0.01% of total mononuclear cells, respectively. Single cell cultures revealed that approximately 37% of BM CD34+ cells formed colonies in the presence of phytohemagglutinin-leukocyte conditioned medium and erythropoietin. Erythroid bursts-, granulocyte-macrophage (GM) colony-, and pure macrophage (Mac) colony-forming cells were 10% each in CD34+ cells. Approximately 15% of PB CD34+ cells formed colonies in which erythroid bursts were predominant. CD34+ cells were heterogeneous and fractionated by several antibodies in FACS multicolor analysis. In these fractionated cells, CD34+, CD33+ cells formed GM and Mac colonies 7 to 10 times as often as CD34+, CD33- cells. Most of the erythroid bursts and colonies were observed in the fraction of CD34+, CD13- cells or CD34+, CD33- cells. The expression of HLA-DR on CD34+ cells was not related to the incidence, size, or type of colonies. There was no difference in the phenotypical heterogeneity of CD34+ cells between BM and PB. About 10% of CD34+ cells were able to form G colonies in response to granulocyte colony-stimulating factor (G-CSF) and to form Mac colonies in GM-CSF or interleukin-3 (IL-3). Progenitors capable of generating colonies by stimulation of G-CSF were more enriched in CD34+, CD33+ fraction than in CD34+, CD33- fraction. Thus, single cell cultures using the FACS clone-sorting system provide an accurate estimation of hematopoietic progenitors and an assay system for direct action of colony-stimulating factors.

Antigens, CD34↗

PubMed1990

In vitro differentiation of leukemic cells to eosinophils in the presence of interleukin-5 in two cases of acute myeloid leukemia with the translocation (8;21)(q22;q22).

We demonstrated the significant eosinophilic growth of leukemic cells in the presence of interleukin-5 (IL-5) in 2 of 15 cases of acute myeloid leukemia. These two cases were M2 (FAB classification) with the translocation (8;21)(q22; q22). Bone marrow examination revealed the rather high percentages (6% and 9%) of atypical eosinophils in the total nucleated bone marrow cells in these two cases. In the remaining 13 cases, eosinophils were less than 2% in the nucleated bone marrow cells. In the methylcellulose culture system, 142 +/- 18 or 54 +/- 2 colonies were formed by 5 x 10(4) mononuclear cells in the presence of IL-5 in these two cases. These colonies mainly comprised mature eosinophils. Eosinophils were confirmed by Biebrich scarlet staining and electron microscopic examination using a specific lectin binding assay. The eosinophilic differentiation and proliferation of leukemic cells were also observed in the liquid culture system. It was shown that eosinophils observed in both systems were derived from leukemic cells using the chromosomal marker of leukemic cells, t(8;21). Leukemic cells also differentiated to neutrophils or both neutrophils and eosinophils in response to granulocyte colony-stimulating factor or interleukin-3, respectively, but did not respond noticeably to granulocyte-macrophage colony-stimulating factor. Although IL-5 acts on normal eosinophil committed precursors as a lineage-specific growth factor, at least some leukemic cells reacted to IL-5 and could proliferate and differentiate along eosinophilic pathway. Our findings suggest that atypical eosinophils observed in the bone marrow were derived from the leukemic clone in two cases of AML.

Cell Differentiation↗

PubMed1989

Effects of the in vivo administration of recombinant human granulocyte colony-stimulating factor following cytotoxic chemotherapy on granulocytic precursors in patients with malignant lymphoma.

We examined the effects of the in vivo administration of recombinant granulocyte colony-stimulating factor (rhG-CSF) on granulocytic precursors in the bone marrow of 4 patients with malignant lymphoma who received chemotherapy. Patients were treated with rhG-CSF at doses of 100-800 micrograms/m2/day intravenously for 14 days only in the first course of chemotherapy (G-CSF course) followed by the second course of chemotherapy without rhG-CSF which was used as a control course. In the G-CSF course, white blood cell counts (WBCs) demonstrated a biphasic response consisting of a first peak observed within a few days after the initiation of rhG-CSF administration, and a second peak observed on the last day of rhG-CSF injection or the day after. In the second peak, the incidence of granulocyte-macrophage colony-forming units (CFU-GM) in mononucleated bone marrow cells did not change significantly after treatment with rhG-CSF as compared with a control. However, since the number of nucleated cells in the bone marrow increased, the absolute number of CFU-GM in the bone marrow increased. The number of mature and immature granulocytes in the bone marrow increased. These findings suggest that G-CSF stimulates the proliferation and differentiation of granulocytic precursors in the bone marrow in granulocytopenic patients who received cytotoxic drugs and causes mature granulocytes to be released from the bone marrow.

Adult↗

PubMedDate not supplied

Long-term culture of fetal liver cells using a three-dimensional porous polymer substrate.

To develop a bioartificial liver, long-term culture of fetal liver cells over a month's time was performed under three different culture conditions, i.e., stationary cultures and shaken-flask cultures, both by using a substratum made of porous polyvinyl formal (PVF) resin and conventional monolayer dish cultures as controls. Time course changes in cell numbers and albumin secretion were evaluated in cultures using Williams' E medium (WE) or minimum essential medium alpha (aMEM) supplemented with serum and hormones. In the WE medium, the numbers of fetal liver cells in all culture conditions gradually decreased with time, and albumin secretion rates rapidly decreased. In the stationary cultures using PVF, however, a significant increase in albumin secretion was observed after two weeks of culture. When cells were cultured in aMEM, the fetal liver cells exhibited sufficient proliferation in stationary and monolayer cultures, although albumin secretion rates per single cell were lower than those in WE. On the basis of these results, another series of culture experiments were performed, in which aMEM was used for the first 10 days to encourage cell proliferation, and the medium was changed to WE afterward. In these cultures, albumin secretion rates in the stationary cultures dramatically increased after the medium exchanges and were maintained at these high levels throughout the remaining culture period.

Animals↗

PubMedDate not supplied

New type of matrix support for bone marrow cell cultures: in vitro culture and in vivo transplantation experiments.

A new type of bone marrow cell culture system was developed by using a highly porous substrate matrix, i.e., porous polyvinyl formal (PVF) resin. Murine bone marrow (BM) cells were cultured without the use of exogenous growth factors in a three-dimensional matrix support made of collagen coated porous PVF resin. To examine the optimal conditions for highest stromal cell density, short-term and long-term in vitro culture experiments using PVF were performed. In the short-term culture experiments, it was found that cubes of PVF (10 x 10 x 2 mm and 130 microm in pore size) coated with type I collagen with a seeding density of 2x10(7) BM cells offered the most appropriate culture conditions. In the long-term cultures, BM cells in PVF maintained their viability for up to 6 weeks. In another series of re-inoculation experiments, freshly isolated BM cells were inoculated onto the already developed stromal layer. In this study, a higher cell density of the stromal layer was obtained in the PVF culture compared with those in the control dish culture. Based upon the results of in vitro experiments, in vivo transplantation studies were also performed. Histologic examinations of the subcutaneously transplanted PVF with stroma revealed host derived hematopoiesis inside the PVF matrix. Moreover, survival of approximately 15% of the transplanted BM cells that were cultured in PVF were confirmed in X-ray irradiated recipients. From these results, it is suggested that PVF resin is a promising three-dimensional substrate for BM cell culture and that it can maintain hematopoietic stem cells or progenitor cells after transplantation.

Animals↗