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T T Glazko

Publications and source records attributed to T T Glazko.

16 recordsLinked to original sources
PubMed2005

["Chain" karyotypic evolution of embryonic stem cell line R1 in vitro].

Cytogenetic anomaly frequencies were analysed in three sublines of ES R1 line in its five clonal sublines, obtained from two cell colonies after transformation of ES R1 cells by plasmid with gene lif. Cell transformation did not increase cytogenic anomalies, however, the initial sublines of ES R1 line, as well as its transformed clonal descendants bore a redundant quantity of the chromosome 8 material within the structure of various Robertsonian translocations even in cells with diploid chromosome quantity (2n = 40). In the initial sublines ES R1 and its clonal descendants a common Rb (8; 15) was revealed. It was supposed that selection for the increase in ES cell sensitivity to cytokines (in particular, LIF) under cultural conditions was accompanied by an increase in chromosomal copies, carrying genes of mapk andjak/stat, through which downstream effectors of cytokine signals for preservation of cell pluripotention and propagation are realized. Genes of chromatid separation and chromosome segregation control (for example, separase gene Esp1 in chromosome 15) may be passively involved in this process, thus promoting acceleration of karyotype evolution in ES cells.

Animals↗
PubMed1993

[The independent variability of different karyotypic characteristics during the spontaneous neoplastic evolution of mouse embryo fibroblasts].

The dynamics of some karyotype characteristics throughout the spontaneous neoplastic evolution of embryonal fibroblasts of different mouse strains was studied using a differential staining of chromosomes. The independent variability of chromosome modal numbers, the number of polyploid cells in the cell line, the number of chromosomal rearrangements within one cell, the activity of formation of different types of chromosomal rearrangements and the activity of interactions of the homologous chromosomes in 15 studied cell lines were revealed. Possible levels of variability regulations of different karyotype characteristics are discussed.

Animals↗
PubMed1991

[The spontaneous aneuploidy of the embryonic fibroblasts in C3H/He and CBA/Ca mouse strains occurring during their neoplastic evolution].

Karyological analysis of 6 cell lines with distinct tumorigenic properties of mouse strains C3H/He and CBA/Ca has been carried out using differential chromosome staining. All the cell lines are characterized by a decreased number of copies of normal chromosome 7, the increased number of normal copies of chromosome 10 being specific of the cell lines with intermediate tumorigenicity. Cell lines with maximum tumorigenicity differed from all other lines by the increased number of copies of chromosome 5 and by the decreased number of copies of chromosome 6. A wide independent variability was observed in the number of chromosomes and of several types of abnormal chromosomes throughout the neoplastic evolution of cells, to begin from the early immortal passages. But the proportion of normal chromosomes per cell in the studied lines revealed relatively stable values. The potential phenotypical heterogenicity of the lines with maximum tumorigenicity, expressed in their clonal progeny, was associated with the instability in the number of chromosome 15 copies in cells of these lines. It is concluded that multiple genetic events are required in the spontaneous neoplastic evolution of fibroblasts, and only specific traits of the karyotypic instability, associated with the variability of the number of copies of specific chromosomes, may constitute the genetic basis for the above process.

Aneuploidy↗
PubMed1990

[The karyotypic variability of mouse embryonic fibroblasts of 2 genotypes during spontaneous neoplastic transformation].

Karyological analysis of 6 lines with distinct tumorigenic properties of mouse strains C3H/He and C57BL/6 has been carried out using a differential staining of chromosomes. The number of normal copies of chromosomes varied in all the investigated cell lines. The more and the less stable chromosomes different from line to line. All the cell lines were characterized by decreased numbers of copies of normal chromosome 7; a decreased number of normal copies of chromosome 2 and 16 was detected in the course of the cell spontaneous neoplastic evolution. The decreased number of normal copies of chromosomes 8, 12 and X, and the increased number of normal copies of chromosome 10 were specific of the cell lines with intermediate tumorigenicity. The maximum tumorigenic cell lines differed from all other lines by increased numbers of copies of chromosomes 4 and 5, and by a decrease in copy number of chromosome 6. The data obtained are discussed in terms of the search of the regularity of karyotypic changes in the course of the cell neoplastic evolution.

Animals↗
PubMed1988

[Karyotypic characteristics of a number of clonal lines of an interspecific mouse-mink hybridoma].

Using G-banding method, a study was made of the karyotypes of mouse myeloma cell line P3-X63-Ag8.653 and some cell hybrid lines originated from a fusion of mink immunized spleen cells and this myeloma. Normal chromosomes 6, 12 and X were not detected in either examined cell of the parental myeloma. The mink chromosomes are preferentially lost from cells of the hybrid lines. These lines varied significantly from cell to cell and from each other in the retention of some mink chromosomes. The karyological study of the hybrid lines revealed some cytogenetical specificities of mouse chromosome composition that were general for cells of hybrid lines, but atypical for myeloma parental cells. This data suggest the cells of myeloma parental line to take part in the processes of somatic hybridization and/or selection for mink immunoglobulin production nonrandomly.

Animals↗
PubMed1988

[Approaches to the analysis of reciprocal chromosome distribution in the bone marrow cells of mice].

A study was made of G-banding chromosome preparations made of bone marrow cells of BALB/c mouse females, injected intraperitoneally with a single dose of the antibiotic adriamycin 23 hours before sacrifice. Frequencies of different chromosome fusions in pericentromeric regions were analysed. All chromosomes were found to be involved in the interchromosomal associations, different chromosomes participating in such fusions with different frequency. No associations of homologous chromosomes were observed. For each chromosome a limited number of preferential partners for fusion was revealed, the number of such partners for different chromosomes varying. Almost for a half of chromosomes, chromosome 15 was one of the most preferred partners. Possible significance of the data obtained is discussed for the analysis of principles of the spatial chromosome arrangement in murine bone marrow cells.

Animals↗
PubMed1980

[Mechanism of a decrease of inducibility of tyrosine aminotransferase by carcinogenic aminoazo dyes. Absence of direct influence of o-aminoazotoluene on the enzyme molecules].

The effect of o-aminoazotoluene (OAT) on the activity of tyrosine aminotransferase (TAT) from mouse liver cytosol under its incubation in the presence of the systems providing for the metabolic activation of the cancerogen (liver microsomes and NADPH2) and dephosphorylation of TAT molecules (light mitochondria and ATP) was studied. It was shown that OAT has neither direct nor indirect (via the phsophorylation--dephosphorylation systems) effect on the activity of TAT. It was concluded that the decrease of TAT induction by hydrocortisone in vivo resulting from injection of OAT to the mice is not due to the direct influence of the cancerogen on the enzyme molecules.

Animals↗
PubMed1978

[Mechanisms of the immunodepression caused by ortho-aminoazotoluene and its noncarcinogenic analog in mice].

Single injections of ortho-aminoazotoluene (OAT) or aminoazobenzene (AB) decrease the immune response of DD mice to the strain-nonspecific Krebs-2 tumor. The immunosuppressive action of AB is due to its toxicity for lymphoid cells, whereas the OAT effect is mediated by adrenal glands. After OAT injection,II-oxycorticosteroids level is elevated although their production by adrenal glands is not increased. The accumulation of glucocorticoids in blood after OAT injection is assumed to be the result of a decreased hormone utilization because of the blockade of receptor proteins or metabolizing enzymes in liver cells by a carcinogen.

11-Hydroxycorticosteroids↗
PubMedDate not supplied

[Species specificity of karyotype instability under conditions of radionuclide contamination (the Chernobyl Nuclear Power Plant) in the voles, Micrototus oeconomus, Micrototus arvalis, and Clethrionomys glareolus].

The comparative analysis of frequencies of different type cytogenetic anomalies in voles Microtus oeconomus, Microtus arvalis, Clethrionomys glareolus trapped in territories with different levels of radionuclide contamination inside the 30-km zone of estrangement around the Chernobyl NPP was carried out. Animals with constitutive chromosome abnormalities were not revealed. The frequency of lympocytes with micronuclei was the most universal and sensitive character to chronic low-dose radiation in investigated species. The species-specific relation was observed between level of radionuclide contamination in trapping zone and increase in frequencies of cytogenetic abnormalities: aneuploidy in Microtus arvalis and metaphase plates with asynchronous centromere fission in Microtus oeconomus. Common vole appears to be the most sensitive species of investigated ones to chronic low-dose ionizing irradiation.

Aneuploidy↗
PubMedDate not supplied

[Hematologic chimerism in cattle twins].

A cytogenetic examination of a cow and its offsprings, obtained by pair transplantations of the embryos was carried out. The fragile X and the heteromorphism of the chromosomes XX of this cow and some of its offsprings were revealed. The variability of the hematological chimerism of the pair transplanted embryos was observed. The immigrated cells were, as a rule, distinguished by the comparatively low frequencies of the metaphases with the nearly located chromosomes XX. The heterogeneity of the stem blood cells of the embryos for some traits, and for the ability to migrate in the blood of the twin is under discussion.

Animals↗
PubMedDate not supplied

[Chronic low doze ionizing irradiation and polyfactors of adaptation].

The analysis of cytogenetic anomaly dynamics in conditions of chronic low doze effect of ionizing irradiation in generations of genetically homogeneous laboratory line of mice CC57W/Mv and genetically heterogeneous populations of vole's species, trapped in alienation zone of Chernobyl's NPP in places with different levels of radio nuclide contamination in 1994-2001 was carried out. The data about the physiological adaptation to ionizing irradiation effects under age of linear mice and non-linearity of frequency changes of separate cytogenetic anomalies in generations as laboratory line of mice, and genetically heterogeneous populations of vole's species were obtained. Was supposed, that the number of non-linear effects of the ionizing irradiation in low doze range could be stipulated by comparability between the intensity of it's damage effects and the activation by it the polyfactor systems of anti oxidant ones, reparation events, and also elimination of defective cells.

Adaptation, Physiological↗
PubMedDate not supplied

[The variability of different cytogenetic characteristics in groups of Black Pied cattle].

The comparative analysis of frequency of occurrence of different indications of cytogenetic variabilities in blood cells of cattle groups (relative healthy, infected by bovine leukosis virus and exposed to ionizing radiation in the Chernobyl zone) was carried out. Both genotoxic influences induced increases in frequencies of cytogenetic defects, but only ionizing radiation induced the increase of chromosome aberration frequency. The heterogeneity of all cattle groups for investigated cytogenetic characters was revealed.

Accidents, Occupational↗
PubMedDate not supplied

[The heterogeneity of the cytogenetic variability in the bone marrow cells of laboratory and wild rodents in the exclusion zone of the Chernobyl Atomic Electric Power Station].

Analysis of the characters of cytogenetic variabilities and correlative interrelations between them revealed the group specificities of karyotype instability in bone marrow cells of some lines of laboratory and of wild mice under the conditions of increased radionuclide pollution in the Chernobyl zone. The complex correlative interrelations between the frequencies of cytogenetic anomalies and the character of cell division (the number of metaphases, binucleated leukocytes per 1000 cells) were observed. The obtained data indicate the stimulatory influence of chronic low doses of ionizing radiation on the manifestation of spontaneous mutagenesis, which has own genotype specific characteristics.

Animals↗
PubMedDate not supplied

[The interrelations between karyotypic stability and interchromosomal associations in mammalian cells].

The interchromosome associations between heterologous chromosomes (for the type of Robertsonian translocations); frequencies of the association between individual chromosomes (identified by G-bands) and mouse line pecularities, the directions of cytodifferentiation, the stages of cell neoplastic transformation in cell populations of various origin have been estimated. The presence of interrelations between individual chromosome associations and genetic and cytological cell characteristics with the use of different mathematical methods of analysis has been revealed.

Animals↗