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N I Drize

Publications and source records attributed to N I Drize.

69 records · Page 4Linked to original sources

[Possibility of using hematopoietic stem cells in relation to their generation age].

A hypothesis of the use of hemopoietic stem cells with a view of satisfying the demand for mature cells depending on their generation age predicts that CFUs that survived after repeated treatment with hydroxyurea should have a greater capacity for self-renewal. It has been demonstrated that after repeated administrations of hydroxyurea according to the scheme devised by the authors of the hypothesis (3-4 times) and as a result of a more prolonged treatment (6 times, every other 12 or 15 h), the capacity of the survived hemopoietic stem cells for self maintenance was not only lower than normal but commonly significantly decreased. The generation-age hypothesis of the use of hemopoietic stem cells thus remains badly needing experimental support.

Animals↗

[Possibility of an artefact in determining hematopoietic stem cell proliferation by CFUs suicide methods].

Spleen colonies in the irradiated mice are produced by both stem cells and by their more differentiated progeny. In the latter case the colonies are transitory, ceasing 10-11 days after cell injection. The transitory colonies may be the cause of systematic artifact during the determination of stem cell proliferation. It was shown in particular that the proliferation of stem cells after sublethal irradiation remains the same, while higher rates of suicide are determined by the death of the precursors of the transitory colonies. At the same time higher proliferation of stem cells is not artifact in lethally irradiated animals and is also detectable after exclusion of the effects of the precursors of the transient colonies.

Animals↗

[Importance of cell contacts for the differentiation of the precursor cells of hematopoietic stroma in long-term bone marrow cultures].

The composite adherent cell layer is produced in the culture of bone marrow fragments. On the contrary, in the culture of single cell suspension of bone marrow, only of monolayer of fibroblast-like cells and macrophages is created. After implantation of the adherent cell layer from the Dexter type culture but not from "fibroblast" culture beneath the renal capsule of syngeneic recipients the ectopic hemopoietic sites are formed. Regeneration of the adherent cell layer may occur only in the course of multilayer formation, i.e. one week after bone marrow transplantation but not three weeks after the formation of the adherent cell layer.

Animals↗

[Colony-forming capacity of the cells from various hempoietic organs of the quail embryo].

Colony-forming capacity of quail yolk sac and embryo was studied after 48 hours of incubation, and that of yolk sac, limb bud and heart germ of the quail embryo after 60 hours of incubation. The concentration of colony-forming units (CFUm) of the 48-hour embryo was shown to be one hundred times higher than that of the yolk sac both after 48 and 60 hours of incubation. The concentration of CFUm in the embryonic limb buds and heart germ after 60 hours of incubation was approximately the same and comparable to the concentration of CFUm in the 48-hour embryo.

Animals↗

[Formation of hematopoietic colonies of the donor type in the bone marrow of irradiated chickens after transplantation of the cells of the yolk sac and hindlimb of the quail embryo].

The ability of yolk sac and primary bone marrow cells of the quail to form hemopoietic colonies at 6 hours of incubation (i. e. before establishment of circulation) was studied in the bone marrow of 3-week sublethally irradiated chickens. The experiments were based on the possibility of differentiating between quail and chicken cells from the natural cell marker (Pheulgen-positive nucleolus). The number of hemopoietic colonies produced by cells transplanted from the primary bone marrow was three times greater than that consequent on transplantation of yolk sac cells. With the given dose of irradiation the bone marrow shows about 75% exogenous (quail) and 25% endogenous (chicken) hemopoietic colonies.

Animals↗

[The precursor hematopoietic cell: its origin in ontogeny, proliferative activity and proliferative potential].

Cells responsible for repopulation of irradiated longterm cultures of murine bone marrow and capable of generating CFUs for at least 4-5 weeks after seeding referred here to as primitive hemopoietic stem cells (P-HSC) were assayed by limiting dilution analysis. During development of mice P-HSC can be detected for the first time in the liver of 12-13-day-old embryos and their number is about 10 per organ. At day 17-18 of gestation the number of P-HSC increases ten-fold; however, we could not detect the proliferation of these cells using the technique of hydroxyurea suicide. In the adult mouse P-HSC content is about 100 precursors per femur and their concentration is one P-HSC per 1-2 x 10(5) bone marrow cells. P-HSC content in the spleen is 0.5 per 10(6) cells. In vivo treatment with 5-fluorouracil or hydroxyurea (six injections every 6 h) does not alter significantly the number of P-HSC, although either treatment kills about 99% of CFUs. Several months after reconstitution of lethally irradiated mice with a "small" inoculum of bone marrow cells (0.20-0.35 x 10(6)) the number of bone marrow P-HSC was reduced as compared to that in animals reconstituted by injection of a "large" cell dose (20-35 x 10(6)). These data suggest that P-HSC have limited proliferative potential and are incapable of self-maintenance.

Animals↗

[Monoclonal antibodies with anti-N specificity].

In this article serologic characteristics of monoclonal antibodies with anti-N specificity is given. Antibodies are directed to homologous sequence of N-form of A glycophorine (group-specific N-antigen) and B glycophorine, expressed both on N- and on M-erythrocytes. Higher titre and avidity of monoclonal antibodies with anti-N specificity in relation to erythrocytes with N-phenotype make it possible to detect N-antigen in material subjected to expert evaluation.

Agglutination Tests↗

[Monoclonal antibodies to the human group-specific antigen].

Serologic description of murine monoclonal antibodies (H-86/44 and H-86/50) which are capable to detect a membrane-connected form of human H antigen is given. The antibodies are notable for ability (H-86/44) to be absorbed by salivary H substance of ABH secretors i.e. to detect a soluble form of H antigen. Highly specific, highly active and standard anti-H reagents may be produced on the basis of the anti-H monoclonal antibodies obtained.

ABO Blood-Group System↗

[Ontogeny-derived hematopoietic stem cells divide successively producing clones of differentiated hematopoietic cells].

Forty seven individual haemopoietic cell clones bearing unique radiation markers were studied in long-term bone marrow cultures. Throughout cultivation, clones appeared at different times, 1 to 12 weeks after explanation, survived during 1-10 weeks and markedly varied in size. Usually, the number of metaphases characteristic of an individual clone rapidly increased, achieved a maximum and declined. The cells of disappeared clones were never seen again. The experimental results provide further evidence for the model of haemopoiesis by clonal succession. The data obtained are discussed with respect to the functioning of haemopoietic stem cell population.

Animals↗

[Radiosensitivity of stromal precursors and mature hematopoietic stromal cells in a culture].

Radiosensitivity of hemopoietic stroma precursors from a long-term culture of murine bone marrow, as measured by the adherent cell layer implantation techniques, was characterized by D0 = 3.02 +/- 0.7 Gy and n = 1.6. Mature cells of the hemopoietic microenvironment survived after doses of up to 100 Gy. Their irreversible damage was only observed after 150-200 Gy irradiation. The results obtained support the suggestion of different histogenetical origin of the hemopoietic and stromal precursors.

Animals↗