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Biomedical subjects

V G Chernikov

Publications and source records attributed to V G Chernikov.

18 recordsLinked to original sources
PubMed2003

Comparison of cytotoxicity of aminoglycoside antibiotics using a panel cellular biotest system.

The cytotoxicity of four aminoglycoside antibiotics was studied by estimation of the dose-effect relationship using a panel cellular biotest system including cell cultures for test objects. The cultures represented 4 differentiation types: normal human fibroblasts and myoblasts, human or Syrian hamster hepatoma cells, and mouse/mouse hybridoma cells. It was found that three widely used antibiotics gentamicin, kanamycin, and neomycin exhibit similar, but not identical cytotoxicity parameters and differ distinctly from geneticin. Hence, the proposed panel biotest system helps to quantitatively evaluate and differentiate the effects of bioactive substances with similar chemical structure.

Aminoglycosides↗
PubMed2001

Cell culture test system for express analysis of cytotoxic and growth-stimulating effects of bioactive compounds.

Cultures of human and mammalian cells presenting 4 types of differentiation (normal human fibroblasts and myoblasts, human and Syrian hamster hepatoma cells, and mouse/mouse hybridoma cells) were used in a panel biotest system. This system allowed to evaluate the cytotoxic and stimulatory effect of bioactive compounds by determining the dose-effect relationships and some quantitative parameters including LD(50). Examination of some biolactive compounds of different nature (sangviritrin, escin, deltostim, cycloheximide, dexamethasone) confirmed high efficacy of this biotest system.

Animals↗
PubMed2001

[Immortalization of human fibroblasts using tsA mutant of SV40 and pSV3neo plasmid].

Clones of immortalized human fibroblasts with an extended life span in culture and a capability of subloning were obtained after the infection with a temperature sensitive mutant (tsA 239) of SV40 virus and pSV3neo plasmid. As compared with the parental cells, the obtained clones exhibited increased plating efficiency, decreased doubling time, and serum dependence. We did not obtained the colony formation during cultivation of immortalized cells in semiliquid agar. This means that our cells were not completely malignant. The PCR (polymerase chain reaction)-analysis has revealed the presence of viral DNA at early passages (25th passage) after the infection by tsA SV40, and its absence after a prolonged cultivation (46th passage). PCR-analysis of the clones obtained after pSV3neo transfection has revealed the presence of gene A sequences either at early (9-15), or later (62) passages. The expression of the gene A product in cells of these clones was revealed only early passages (11 and 35). Possible mechanisms of immortal phenotype origin in human diploid cells after the action of ts-mutant and other constructions of SV40 are discussed.

Antigens, Polyomavirus Transforming↗
PubMed2000

Use of cultured human fibroblasts for rapid evaluation of cytotoxic effects of bioactive substances.

A test system for detecting cytotoxic effects of bioactive substances based on human fibroblast culture is proposed. The effects of acrylamide, streptomycin, cycloheximide, sodium dodecyl sulfate, sanguiritrine, and ethanol were evaluated by organic stain binding. Typical dose-effect relationships were detected for all substances except cycloheximide. The proposed test system can be used for screening of bioactive substances in preclinical trials.

Cell Culture Techniques↗
PubMed1984

[Variability of alkaline phosphatase activity in diploid human cells in vitro].

Experiments were made with 19 strains obtained from different tissues (skin, lungs, muscles) of 8-10-week-old medical abortions and skin biopsies of healthy donors to study the manifestations of alkaline phosphatase (AP) activity in human diploid cells in vitro. Based on the data obtained it is concluded that AP activity is marked by demonstrable intra- and interstrain variability. The spectrum of "AP activity" trait variability is broader for transformed cells than for human diploid cells.

Adult↗
PubMed1984

[Production of antibodies by hybridomas in a serum-free culture medium].

Evidence is presented that hybridomas maintained in serum-free medium continue to secrete antibodies for some time. The dynamics of this secretion appears to be close to that in analogous cultures kept in the serum medium but apparently differs from that in analogous cultures grown in the balanced salt solution. The possibility of hybridomas to synthesize antibodies in protein free medium and not only to release those formerly synthesized is under discussion.

Animals↗
PubMed1983

[Simultaneous activity of nucleolus organizer regions of human and Chinese hamster chromosomes in somatic cell hybrids].

In an interspecific human-Chinese hamster hybrid that retains 13 and 85.6% of the chromosomes of each parental complement, activity of nucleolus-organizing regions (NOR) of both type chromosomes is observed in 18.9% of the cells. Interspecific chromosomal associations are also noted. Unlike the parental lines of Chinese hamster cells, the hybrids show the associations of the NOR of Chinese hamster chromosomes. In hybrid cells, there occurs partial suppression of NOR activity in human and Chinese hamster chromosomes, while the NOR of the 3d chromosome of the Chinese hamster is completely suppressed.

Animals↗
PubMed1982

[African green monkey cell line RAMP simultaneously resistant to 8-azaguanine, 6-mercaptopurine, and 6-thioguanine].

African green monkey RAMT cell line was isolated from the permanent cell line 4647 in a medium containing 10 micrograms/ml 8-azaguanine, 6-mercaptopurine, and 6-thioguanine. The RAMT cells cannot grow in a medium containing thymidine, hypoxanthine, aminopterine and glycine because of the lack of hypoxanthine utilization due to hypoxanthine phosphoribosyltransferase deficiency. It was shown that 40% of the RAMT cells contain 57-58 chromosomes, and 20% of the cells are tetraploid. Like normal karyotype of the animal, the RAMT cells have two chromosomes with nucleolar organizer regions (NOR). One of them has an additional segment on the short arm and a large NOR revealed by silver staining. The cytoplasm of the RAMT cells was not found to have mycoplasma-like particles detected by the Hoechst 33258 fluorescent method. These characteristics enable the use of the RAMT cells for somatic cell hybridization.

Animals↗
PubMed1982

[Isolation of hybrid clones of human-rodent somatic cells].

Mutant cells of Chinese hamster or mouse were fused with normal embryonic human cells. The fusion was induced by polyethylene glycol. The Eagle medium containing hypoxanthine, aminopterine, thymidine, glycine, and ouabain served as a selective medium. The parent cells were completely destroyed in the selective medium. The hybrid cells formed colonies which were isolated and reproduced for cytogenetic analysis. The cytogenetic analysis has confirmed the hybrid origin of the isolated clones.

Animals↗
PubMed1981

[Use of polyethylene glycol for the microinjection of exogenous protein into cultured murine cells].

Polyethylene glycol was applied to microinject two exogenous proteins: bovine serum albumin and non-histone protein derived from mouse spleen chromatin, into the mouse L-cells. The effectiveness of fusion of mammal (human, in the given case) erythrocytes in which hemoglobin is substituted for the protein under study was shown to be higher than when Sendai virus was used. The microinjected proteins preserve their specificity to subcellular structures.

Animals↗
PubMed1976

[Isolation and characteristics of temperature sensitive mutants in a culture of Chinese hamster cells].

The treatment of a temperature-resistant glutamine-independent clone of Chinese hamster cells (237 glu+ tr) with 5-bromodeoxyuridine (BUdR) for 48 or 72 hours at 40 degrees C and subsequent illumination with visible light was used for selection of spontaneous and N-methyl-N'-nitro-N-nitrosoguanidein-induced ts mutants. 30 clones were isolated. Their temperature-sensitivity was studied at two cell densities: 500 and 10000 (or 15 000) cells per dish. 21 clones proved to be temperature-sensitive. The expression of temperature-sensitivity of 11 clones was independent of cell densities used. The remaining 10 clones could be divided in two groups: those expressing temperature-sensitivity only at low plating inoculum (6 clones) and those temperature-sensitive at 10 000 (15 000) plated cells per dish (4 clones). Possible mechanisms of this phenomenon are discussed. Most isolated clones behaved as leaky mutants. Isolation of ts clones without special mutagen treatment from a tr cell population after its permanent incubation at 40 degrees C, restrictive for ts cells, is regarded as strong evidence in favour of the mutagenic effect of BUdR and visible light.

Animals↗
PubMed1976

[Spontaneous and induced mutagenesis in a culture of Chinese hamster cells].

Spontaneous and nitrosoguanidine (NG)-induced rate of reversions to glutamine independence was studied in cultured temperature-sensitive glutamine auxotrophs of Chinese hamster cells. In 3 experiments the spontaneous rate of reversions varied from 0.8-10(-6) to 3.84-10(-6) per cell per generation. A dependence of the yield of NG-induced back mutations upon the time interval between the mutagenic treatment and the transfer to selective conditions (glutamine deficient medium, 40 degrees C) was established. No induced revertants were detected when cells were transferred to selective conditions immediately after the treatment with NG. After 2--3 days cultivation in glutamine containing medium at 36 degrees C and the sunsequent transfer to selective conditions the frequency of induced reversions varied from 0.56-10(-4) to 10.55-10(-4) in different experiments; after 6 days -- from 0.05-10(-4) to 4.0-10(-4). In all cases where induction was detected, the difference, between the frequency of glutamine prototrophs in treated and control plates was significant. Glutamine independence proved to be stable after prolonged cultivation under non-selective conditions, the degree of prototrophy being greatly unequal in different clones. No differnce in this respect was detected between spontaneous and NG-induced revertants. The proposed system of reverse mutations can be used for studying diverse problems of somatic cell genetics.

Aneuploidy↗