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Biomedical subjects

I L Chertkov

Publications and source records attributed to I L Chertkov.

At least 91 records · Page 5Linked to original sources

[Role of bone marrow stroma in the phenomenon of hybrid resistance].

In the site of hemopoiesis produced by implantation of an irradiated bone marrow plug beneath the kidney capsule all dividing hemopoietic cells were of recipient origin, as shown by karyologic analysis. In such implants hybrid resistance was of the donor's type. It is suggested that the migrating cells of hemopoietic origin, including lymphocytes and macrophages, do not participate in producing the hybrid resistance.

Animals↗

[Self-maintenance of migrating hematopoietic stem cells].

Decreased self-maintenance ability of the migrating stem cells (CFU) from the peripheral blood or ectopic focus of hemopoiesis in comparison to the settled bone marrow CFU, as measured by the spleen colony method or by means of chromosomal markers, has been studied. The competence for myeloid and lymphoid differentiation was essentially the same for migrating and settled stem cells.

Animals↗

[Effect of abrogating hybrid resistance on the survival of radiation chimeras].

A study was made of the effect of the hybrid resistance abrogation by means of the lymphoid cell administration on the survival of the lethally irradiated mice protected by the transplantation of the semiallogeneic bone marrow. Injection to the C57BLxCBA recipients of the C57BL lymphoid cells one day before the irradiation and the transplantation of the bone marrow of the same genotype (C57BL) increased the chimera survival in comparison with the untreated recipients; such pretreatment 7 days before the irradiation decreased the chimera survival. Parental spleen lymphocytes administration produced but an insignificant effect on the radioresistance both of the stem hemopoietic cells (by the endocolonisation test) and of the organism as a whole (by the 30-day survival test) of the F1 hybrid. On this basis a conclusion was drawn that the differences in the splenocyte efficacy, when they were injected at different periods before the irradiation, could not be attributed to the changes in radioresistance.

Animals↗

[2 populations of bone marrow cells transfering the hematopoietic environment].

A bone marrow fragment transplanted under the kidney capsule created a focus of ectopic hemopoiesis, whose isze, measured by the number of hemopoietic cells, was proportional to the implant size. Dimensions of the focus proved to be 11/2--21/2 greater in the irradiated than in the intact recipients. Cells building up the focus of heterotopic hemopoiesis had a different radiosensitivity in the intact and irradiated recipients--their Do constituted about 160 and 350 rad, respectively. In this connection it is supposed that two cell populations of precursors took part in the creation of the focus. Their possible relations with the determined and inducible osteogenic precursor cells are discussed.

Animals↗

[Hybrid resistance to precursor cells of bone marrow stroma].

A focusl of hemopoiesis appearing after the transplantation of a bone marrow fragment of C57BL mice to syngeneic mice (under the kidney capsule) contained more hemopoietic cells than in transplantation to the semisyngeneic (CBA X C57BL) FI recipient. Experiments were conducted with a secondary seeding by intravenous injection of hemopoietic cells of the C57BL transplant genotype into the transplant depopulated by irradiation; it was shown that these differences were caused by lesser dimensions of the hemopoietic microenvironment in the focus in the hybrid organism in comparison with such in the syngeneic system. Thus, the hybrid resistance was expressed not only to the hemopoietic cells, but also to the stromal precursors transferring the hemopoietic microenvironment.

Animals↗

[Origin of hematopoietic cells in a syngenous and semisyngenous focus of heterotopic hematopoiesis].

Heterotopic hemopoiesis foci were produced by the bone marrow of C57BL/6 or (CBA X C57BL)F1 mice grafted under the renal capsule of (CBAT6T6XC57BL)F1 mice, bearing the chromosomal translocation. The cytogenetic analysis of the hemopoietic cells in the foci 20 to 120 days after the transplantation showed that in 40% of the transplants only the recipient's hemopoietic cells proliferated, whereas the rest were mosaic and contained on the average less than 20% of donor's cells both in the syngeneic and in the semisyngeneic systems. These characteristics remained stable for at least 4 months. The data obtained suggest a single inflow of not less than 10 effective hemopoietic stem cells per graft. The clone stability indicated that during the steady-state hemopoiesis the cell exchange between various regions of the hemopoietic system was not great, if any.

Animals↗

[Classification of tumors of the blood systems--hemoblastoses].

The article presents a review of new concepts of pathogenesis of leukemia and changes in the schemic of hemopoiesis, which lead to the need to re-examine the existing classification of leukemia. In view of the fact that histogenetic independence of stromal and hemopoietic elements has been proved, there is no need any more for the generalizing term "reticulosis". The authors substantiate the need for differentiation between some acute an chronic leukemias and to consider them as independent nosological forms grouped according to morphological and pathogenetic characteristics and a specific treatment required. These forms, for example, include acute lymphoblast leukemia in children, among acute leukemias - hair cell leukemia, and among chronic leukemias- diseases of heavy chains. Criteria for their identification, as well as probable sources of separate forms of leukemias are described.

Acute Disease↗