Biomedical subjects

H Izumi-Hisha

Publications and source records attributed to H Izumi-Hisha.

3 recordsLinked to original sources

PubMed1991

Monoclonal antibodies against a preadipose cell line (MC3T3-G2/PA6) which can support hemopoiesis.

Monoclonal antibodies against a mouse preadipose cell line (MC3T3-G2/PA6:PA6), which can support hemopoiesis by direct cell-to-cell interaction, were produced and characterized. The antibodies react with PA6 but not PA6-M (a mutant cell line) which has the capacity neither to contact with hemopoietic stem cells (HSCs) nor to support hemopoiesis. Endosteal cells in the bone marrow show positive staining to these antibodies. They inhibit pseudoemperipolesis of PA6 to HSCs, resulting in a significant decrease in hemopoietic cell number. These findings suggest that the monoclonal antibodies bind to the stromal cell receptors for HSCs and block the binding of HSCs to stromal cells leading to suppression of hemopoiesis.

Adipose Tissue↗

PubMed1990

Age-related decrease in the number of hemopoietic stem cells and progenitors in senescence accelerated mice.

Senescence accelerated mice (SAM-P) were used for the study of the possible aging of hemopoiesis. The number of peripheral leukocytes decreased significantly with age, whereas hematocrit showed only a slight decrease. Although the number of total nucleated cells in the bone marrow increased, the number of hemopoietic stem cells (CFU-S) as well as that of granulocyte-macrophage colony forming cells (GM-CFC) showed a decrease in old mice. A significant decrease in the number of GM-CFC was observed in the spleen of old SAM-P mice, whereas no decrease was found in the number of CFU-S. Such a profound reduction of the recruitment of GM-CFC from CFU-S in the spleen together with a reduction of bone marrow hemopoiesis may be responsible for the decrease in the number of peripheral leukocytes in the old mice. SAM-P mice could provide a good model for the study of the aging of hemopoietic system.

Aging↗

PubMed1989

Long-term effects of high doses of cytosine arabinoside on pluripotent stem cells (CFU-S).

The purpose of this work was to investigate the long-term effects of high doses of cytosine arabinoside (Ara-C) on the pluripotent stem cell (spleen colony-forming units; CFU-S) compartment in mice. Studies were carried out on mice that survived the administration of repeated high doses of Ara-C (HDAra-C) with or without the injection of a partially purified CFU-S inhibitor or a bone marrow graft. The following features were examined 1, 1.5, and 5-7 months after treatment: CFU-S number, proliferative ability, and differentiation into different lineages. The results indicate that these parameters, which were severely disturbed soon after drug administration, returned to control levels within a month and remained unchanged as compared to age-matched controls for the following 6 months. Therefore, HDAra-C, given alone or with a CFU-S inhibitor or prior to bone marrow grafting, did not seem to induce long-lasting damage of the CFU-S compartment. However, our studies cannot eliminate the possibility of some residual stromal damage or some impairment of other properties of stem cells. It would be of importance to further clarify these points because HDAra-C are now used in the treatment of leukemias and prior to bone marrow transplantation.

Animals↗