Search PubMed⌕ Search

Biomedical subjects

N V Popova

Publications and source records attributed to N V Popova.

At least 19 recordsLinked to original sources
PubMed2004

Genetic regulation of mouse stem cells: identification of two keratinocyte stem cell regulatory loci.

It is well documented that the bulge of hair follicle is a 'niche' for a significant population of mouse keratinocyte stem cells, and 95% of rodent clonogenic keratinocytes originate from the bulge region. The ability to form colonies in vitro is a well recognized test for keratinocyte stem cells. We analyzed the epidermis of seven mouse strains and their segregating crosses [(BALB/c x C57BL/6)F1; (BALB/c x CB6F1); (C57BL/ 6 x CB6F1); (CBF1 x CBF1)F2] for their clonogenic activity in vitro. We found that keratinocyte colony (KC) number is a new quantitative multigenic trait. The analysis of KC size in two parental strains (C57BL/6 and BALB/c), the F1 generation and the segregating crosses demonstrated that the size of KC is a quantitative complex trait also. We determined that mouse epidermis has at least two subpopulations of keratinocytes that gave small (< 2 mm2) and large (> 2 mm2) colonies. The differences in the number of small and large colonies between parental strains (C57BL/6, BALB/c) were significant (P < 0.01). A genome-wide scan of the intercross and the two backcrosses maps the number of small KC to the central region of mouse Chromosome 9 (genomewide P value = 0.01). We define this locus as Ksc1. The proximal region of chromosome 4 is associated with the high number of large KC. We defined this locus as Ksc2. We found that Ksc1 and minor loci on chromosomes 6 and 7 map close, if not equal to, loci associated with mouse skin carcinogenesis. We conclude that mouse epidermis has at least two subpopulations of clonogenic keratinocyte stem cells that are regulated by different genes. We suggest that keratinocyte stem cells responsible for small colonies may play a major role in the regulation of resistance or sensitivity to skin carcinogenesis. Investigation of the genes regulating the stem cell number should provide new insight into the mechanisms of skin carcinogenesis, and should help to develop new approaches for therapies not only against active proliferating tumor cells but also quiescent tumor stem cells.

Animals↗
PubMed1997

Pentylenetetrazol and strychnine convulsions in brain weight selected mice.

The seizure sensitivities to pentylenetetrazol (Ptz, 25-100 mg/kg) and strychnine (S, 2 mg/kg) were tested in two mice lines selected for large (LB) and small (SB) brain weight (brain weight difference being approximately 75 mg). The selection was based on a regression line connecting body and brain weight. SB mice were more sensitive to both drugs-their seizure latencies were shorter and lethality higher than in LBs. The seizures generated by Ptz and S are known to affect different neurotransmitter systems. The interstrain differences in seizure susceptibility are probably determined by SB mice nervous system traits rather than by differences in the particular neurochemical trait. The data on neocortical cytoarchitectonics obtained during our previous brain selection experiment could serve as the indirect evidence favouring such a suggestion.

Animals↗
PubMed1997

[Selection of mice for brain weight].

The results of two experiments on selection of laboratory mice for large and small brain weight are presented. Selection was based on the regression relationship between body and brain weight. This allowed considerable differences in brain weight to be obtained accompanied by insignificant interlinear differences in body weight compared to the range of intralinear variation. The two lines of mice with a large and small brain weight (F9-F10) differed significantly in brain weight. The absolute difference was 60-70 mg, i.e., approximately 13% of the brain weight in the original heterogeneous population.

Animals↗
PubMed1994

[Cellular immunity in patients with gonorrhea and gonorrhea-chlamydia infection during treatment with pefloxacin in combination with thymogen].

The ultrastructural analysis showed that under the effect of abaktal (pefloxacin) the incomplete phagocytic reaction completed, the phagocytosis being of the multistage character. The morphometric analysis of the blood leukoconcentrate revealed an increase in the polymorph digestion function after the exposure to combinations of immunomodulators with abaktal which was in favour of the abaktal recommendation for the treatment of gonorrheal-chlamydial infection.

Adjuvants, Immunologic↗
PubMed1993

Genetic aspects of animal reasoning.

This paper reviews the investigations of Prof. L. V. Krushinsky and his colleagues into the genetics of complex behaviors in mammals. The ability of animals to extrapolate the direction of a food stimulus movement was investigated in wild and domesticated foxes (including different fur-color mutants), wild brown rats, and laboratory rats and mice. Wild animals (raised in the laboratory) were shown to be superior to their respective domesticated forms on performance of the extrapolation task, especially in their scores for the first presentation, in which no previous experience could be used. Laboratory rats and mice demonstrated a low level of extrapolation performance. This means that only a few laboratory animals were capable of solving the task, i.e., the percentage of correct solutions was equivalent to chance. The brain weight selection program resulted in two mice strains with a 20% (90-mg) difference in brain weight. Ability to solve the extrapolation task was present in low-brain weight mice in generations 7-11 but declined with further selection. Investigation of extrapolation ability in mice with different chromosomal anomalies demonstrated that animals with Robertsonian translocations Rb(8,17) 1lem and Rb(8,17) 6Sic were capable of solving this task in a statistically significant majority of cases, while mice with fusion of other chromosomes, as well as CBA normal karyotype mice, performed no better than expected by chance. Mice with two types of partial trisomies and animals homo- and heterozygous for translocations were also tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Different effects of peptides and their amino acids on antibody production and phagocytic activity of the neutrophils in mice].

The effects of some natural polypeptides fragments and amino acids which were incorporated in them on the thymus-dependent SRBC immune response and on the phagocytosis of Staphylococcus by murine peritoneal neutrophils were compared. It was found that the peptides LGIP and PYIK which consisted of those amino acids that stimulated phagocytosis but did influence the immune response (K, P, Y, L) did not change the immune response as well as phagocytosis. The peptides TKPR, TTKD and LGIPE which included those amino acids that were able to stimulate both immune response and phagocytosis (T, E, D) enhanced both activities. Nevertheless the peptide PYIKV containing valine (that stimulated the antibody production as well as phagocytosis) did not effect the immune response but enhanced the phagocytic index. The existence of two immunoregulatory systems--the peptide system and the amino acid one--was suggested.

Adjuvants, Immunologic↗
PubMed1989

Transgenerational effect of orthoaminoasotoluol in mice.

Transplacental effect of orthoaminoasotoluol (OAAT) on the liver was studied in 3 generations of CBA mice. OAAT was administered to mice intragastrically at the 17, 18 and 19th day of pregnancy. A high incidence of liver tumors was observed in males (73.1% compared with 40.6% in control animals) and 34.3% in females compared to 4.6% in control animals which were the F1 descendants of treated mothers. The females of the F2 generation which were not in direct contact with OAAT developed a statistically higher, compared with the control incidence of liver tumors (24%). The liver tumor incidence in males of the F2 (20.6%) and F3 (17.8%) generations was lower than in the control group (40.5%). The liver tumor incidence in the controls was similar to that observed in F3 females (4.05%).

Animals↗
PubMed1988

[Morphogenesis of primary biliary liver cirrhosis].

Light and electron microscopy were employed for evaluation of hepatic biopsies (9 puncture and 3 operative) to study morphologic changes in small bile ducts and lobular parenchyma in primary biliary cirrhosis (PBC). Altogether 12 female patients with PBC stage I and II and aged 36-59 were examined. Immune cytolysis of biliary epithelium indicative of delayed-type hypersensitivity is shown to underlie destructive cholangitis. The appearance of the canals between hepatocytes of the hepatic plate which connect biliary capillaries with perisinusoidal space evidence for impairment of hepatic lobular parenchyma. Cholemia and absence of hepatic cholestasis in PBS stage I may be due to bile capillary drainage into the hepatic sidusoids along these newly originated intercellular canals.

Adult↗
PubMed1985

[Immunomorphological study of cytochrome P-450PB induction in the liver of rat embryos and pregnant females after phenobarbital administration].

Cytochrome P-450 PB localization in the livers of embryos, pregnant, non-pregnant female, and male Wistar rats was investigated immunomorphologically after phenobarbital (PB) treatment. The highest level of cytochrome P-450 PB induction was observed in the livers of male rats where the antigen invaded almost the whole liver lobule. About half of the cells within the lobule of non-pregnant female rat livers were stained and were located around the central vein area. Pregnant females had two times less indication than the non-pregnant group and only a quarter of the cells in the lobule of the liver adjacent to the central vein were stained for P-450 PB. The indication of cytochrome P-450 PB was absent from 17-18-day-old embryonal livers which were subjected to the transplacental action of the inducer. Only in one case out of seven were small groups of cells and single cells in the embryonal liver stained positively for cytochrome P-450 PB. It is obvious that during pregnancy, the mother's body exerts a significant influence on the detoxifying function of the fetal liver.

Animals↗
PubMed1980

[Comparative study of organ cultures of human, rat, mouse and chick embryonic livers].

The organ cultures of the human, rat, mouse and chick embryonic liver were studied comparatively. Three developmental stages were established upon the long-term cultivation of the explants: adaptation of tissue, optimal growth, and terminal stage resulting in the culture death. The species and strain differences in the morphology and survival of the cultures were revealed. Foci of growth of small basophilic epithelial-like cells, differing from usual embryonic hepatocytes by morphology, growth pattern, survival and proliferative activity, were found in the organ cultures. The results obtained are interesting for the understanding of histogenesis of the normal liver and of mechanisms of hepatocarcinogenesis.

Animals↗
PubMed1979

[Growth-stimulating action of nitroso compounds on organ cultures of mouse and rat embryonic liver].

Transplacental and direct effects of nitroso-methylurea (NMU) on the organ cultures of the liver of 18-20-day embryos of CBA and C57BL mice and the action of diethylnitroso-amine on the embryo liver cultures of noninbred rats were studied. Nitroso-compounds acclerated explant adaptation, enhanced the culture survival as compared with the normal and induced hyperplastic proliferation of small basophilic cells, whose survival in the experiment and under normal conditions was higher than that in the normal embryonal hepatocytes. The growth-stimulating effect depended on the animal species and strain and on the carcinogen, as weel as on the route of administration.

Animals↗