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Biomedical subjects

N G Khrushchov

Publications and source records attributed to N G Khrushchov.

At least 19 recordsLinked to original sources
PubMed2005

Characteristics of human neural stem cells in vitro and after transplantation into rat brain.

We studied the effect of culturing conditions on the fate of human neural stem cells after transplantation into rat brain. Human neural stem cells cultured in the presence of mitogens without LIF migrated along the ependyma and cerebral vessels of recipients, but to a great extent degenerated by the 20th day after transplantation. Neural stem cells cultured with LIF migrated, apart from the above mentioned pathways, in the cortex and hippocampus, well survived; proliferating cells were retained 30 days after transplantation.

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PubMed2002

Studies on clonogenic hemopoietic cells of vertebrate in space: problems and perspectives.

Hemopoietic tissues were studied in vertebrates launched aboard the Soviet (Russian) biosatellites ("Cosmos-1129, 1514, 1667, 1887 and 2044"; "Bion-10 and 11") between 1980 and 1996. In the bone marrow of rats exposed to spaceflight conditions, a statistically significant decrease in cell number was revealed in the progenitor cell compartment accounting for the compensatory response of granulocyte-macrophage (CFU-gm) and erythrocyte lineages (BFU-e and CFU-e) and in the compartment of multipotent hemopoietic stem cells (CFU-s), which is responsible for the permanent renewal of hemopoietic tissue. The number of stromal fibroblastic progenitors (CFC-f) in the bone marrow of these rats was also reduced. Apparently, changes in the hemopoietic stroma damage the hemopoietic microenvironment and, hence, may be responsible for changes observed in the hemopoietic tissue proper. Attempts were made to develop methods for analyzing morphologically indiscernible clonogenic hemopoietic cells of newts, and studies on the effects of spaceflight factors on these cells were performed. The results showed that the numbers of clonogenic cells in newts of the flight group newts were significantly lower than in control newts. The data obtained are used as the basis for formulating the problems to be studied, drawing up a program for further research on the effects of spaceflight factors on stem and other clonogenic hemopoietic cells, and developing new experimental models for analyzing stem cells, the state of the hemopoietic stroma, etc.

Animals↗
PubMed1997

Experimental analysis of cell interactions during hemopoiesis.

The principal approach was to study hemopoiesis on different stromal cell underlayers (fibroblasts or fibroblast-like cells covering a foreign body implanted into the peritoneal cavity of mice or other rodents) after intraperitoneal transplantation of syngeneic, allogeneic, and xenogeneic hemopoietic cells. The data obtained are compared with the results of experiments on repopulation of ectopic hemopoietic territories (under the mouse kidney capsule) by syngeneic and xenogeneic hemopoietic cells. Competitive cell interactions are described that occur during repopulation of the hemopoietic stroma or formation of the hemopoietic foci on cellulose acetate membranes (CAMs) in the peritoneal cavity of irradiated mice by genetically different hemopoietic cells transplanted to these animals (multicomponent radiation chimeras). The model of xenogeneic and multicomponent radiation chimeras was reproduced in long-term bone marrow cultures, where hemopoietic cells of different genotypes coexisted, without any competitive cell elimination. The second part of this review deals with hemopoiesis on stromal cell underlayers, formed by cells of different origin, different stages of development, and obtained from other sources. These underlayers were formed on CAMs in vitro and then transferred into the peritoneal cavity of irradiated mice, which subsequently received intraperitoneal injections of donor hemopoietic cells. Specific features of hemopoiesis on stromal underlayers formed by the following cell types are described: (1) fibroblasts from mouse embryos at different developmental stages; (2) fibroblasts from the skin, liver, and bone marrow of 17-day mouse fetuses and newborn mice; (3) fibroblasts from the monolayer cultures of mouse and rat bone marrow; (4) 3T3 cell line; (5) hepatocytes of 17-day mouse fetuses or sexually mature rats; (6) newborn mouse kidney cells; and (7) cells transgenic for the erythropoietin gene. The phenomena observed in these experiments and their probable mechanisms are discussed.

Animals↗
PubMed1996

Blood and clonogenic hemopoietic cells of newts after the space flight.

Ribbed newts were used for studying the effect of space flight on board of the biosatellite (Cosmos-2229) on blood and clonogenic hemopoietic cells. In blood of newts of the flight group, the relative proportion of neutrophils increased, whereas that of lymphocytes and eosinophils decreased. Space flight did not result in loss of the ability of newt blood cells to incorporate H3-thymidine. Analysis of clonogenic hemopoietic cells was performed using the method of hemopoietic colony formation on cellulose acetate membranes implanted into the peritoneal cavity of irradiated newts. To analyze reconstitution of hemopoiesis after irradiation donor hemopoietic cells from flight or control newts were transplanted into irradiated newts whose hemopoietic organs were investigated. The newt can be considered an adequate model for studying hemopoiesis under the conditions of the space flight.

Animals↗
PubMed1986

[Effect of a leukocytic serum preparation on hematopoietic cells in vitro].

The effects of leucocyte serum (LS) on bone marrow cells (BMC), thymus and HL-60 human myeloid leukemia cells were studied in liquid suspension and agar cultures. LS increased 3H-thymidine incorporation in BMC and intensified the cloning efficiency of granulocyte-macrophage progenitor cells (CFU-GM) and human myeloid leukemia cells. No significant stimulatory effect on thymus cells was observed. It has been shown that LS prevents or markedly decreases the effect of granulocyte inhibitor (GI-3S2).

Animals↗
PubMed1985

[Structure of ectopic foci of hematopoiesis in the mouse].

By means of light and electron microscopic methods foci of ectopic hemopoiesis have been investigated. They are formed on acetate-cellulose (AC) membranes implanted into the mice peritoneal cavity and into the mesentery after radiation and intraperitoneal injection of a donor's bone marrow. On the surface of the AC-membranes predominantly granulocytic differentiation of hemopoietic colonies is observed, prevalence of fibroblasts in the sublayer composition, absence of contacts of hemopoietic elements of the colonies with cells of the sublayer. In the mesentery mixed hemopoietic colonies of the donor's origin are revealed consisting of elements of granulocytic, macrophagal and megakaryocytic lines of differentiation. In the mesenteric colonies there are noted mesothelial cells, lipocytes, macrophages, and reticular cells having contacts with hemopoietic cells. The role of the sublayer cells for formation and differentiation of the hemopoietic foci in the experimental systems studied is discussed.

Animals↗
PubMed1985

Changes in the number of haemopoietic stem cells (CFUs) in bone marrow and spleens of pregnant rats after a short space flight onboard the Cosmos-1514 biosatellite.

After a 5-day stay in a state of weightlessness onboard a biosatellite Cosmos-1514 the pregnant rats exhibited a decrease in the number of haemopoietic stem cells (CFUs) in bone marrow and spleens on the recovery day after the space flight as compared to rats kept in the vivarium under usual conditions. The different changes in the concentration of CFUs in the bone marrow and spleens of flight and synchronous control rats indicate that the extent of the decrease in CFUs pool in the spleens of flight rats was significantly influenced by the action of non-specific flight factors.

Animals↗
PubMed1984

[Capacity of intact and regenerating liver to trap CFUs].

The normal and regenerating mouse liver is capable of trapping transplanted bone marrow CFUs, with this capability being increased in the regenerating liver. Inactivation of macrophages (Kupffer cells) by silica particles sharply reduces this ability, thus pointing to direct or indirect involvement of macrophages into the trapping of exogenous CFUs.

Animals↗
PubMed1983

[Stromal cells of the regenerating bone marrow in rats (an immunocytochemical electron microscopy study)].

Process of the bone marrow regeneration has been studied after its removal out of the rat femoral bone cavity. The stage of stroma formation precedes hemopoiesis. The stromal cells during its reconstruction (the 4th-5th day after removal of the bone marrow) are analyzed by means of the indirect immune-peroxidase electron microscopical method with antiserum applied against insoluble antigens of the rat bone marrow cells. Most of the stromal cells do not fix the antiserum used, as do the hemopoietic cells, macrophages and preosteoclasts. Some part of the stromal cells (not more than 30%) demonstrate the immune-peroxidase label. The labelled stromal cells have some ultrastructural signs of poorly differentiated elements of fibroblastic and osteoblastic raws. In the regeneration area, there are non-labelled poorly differentiated cells, which do not differ, at the ultrastructural level, from labelled poorly differentiated stromal elements. Possible causes of the difference revealed among the poorly differentiated stromal cells concerning their fixing of the anti-bone-marrow antiserum are discussed.

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