[A quantitative evaluation of the changes in the proliferation of a human lymphocyte culture after mutagen exposure at the G0 stage]. / Kolichestvennaia otsenka izmeneniia proliferatsii kul'tury limfotsitov cheloveka posle vozdeistviia mutagenami na stadii G0.

Cell cycle delay of human lymphocytes treated with mutagens at G0 stage has been studied using a mathematical model. Cell cycle delay depends on entry cells into the first S phase and is independent on the cell cycle duration.

[A mathematical model of the proliferative kinetics of cells labelled with brominated DNA precursors]. / Matematicheskaia model' proliferativnoi kinetiki kletok, mechennykh bromirovannymi predshestvennikami DNK.

A mathematical model of cell division is presented. It permits analyzing cell proliferation obtained by using BrdU. Numerical experiments show that this model adequately describes experimental data. Application of this model permits decreasing experimental data bulk.

[The frequency of sister chromatid exchanges in cultured cells of mouse blood, bone marrow and spleen]. / Chastota sestrinskikh khromatidnykh obmenov v kul'tiviruemykh kletkakh krovi, kostnogo mozga i selezenki myshei.

Analysis of factors leading to the increase of SCE in vitro is presented. Frequency of SCE is the same in the blood, spleen, marrow cell culture and does not influence upon the time of culture and BDU or BDC concentration. The authors consider that procedure preparation of the culture leads to an increase of SCE in vitro as compared to in vivo.

[The duration of cell cycle phases studied using 5-bromodeoxycytidine]. / Izuchenie prodolzhitel'nosti faz kletochnogo tsikla s pomoshch'iu 5-bromdezoksitsitidina.

The quantitative method is suggested to estimate cell cycle phase durations and dispersions of progress through the phases for population of cells. The method is based on the analysis of frequency of cells with different staining of sister chromatids by means of 5-bromodeoxycytidine. The process of cell population progress is described by the Gauss probability integral. The durations of the cell cycle phases are determined for cell culture of Chinese hamster.

[Simultaneous estimation of sister chromatid exchange and evaluation of cell cycle delay]. / Uchet sestrinskikh chromatidnykh obmenov odnovremenno s otsenkoi zaderzhki kletochnogo tsikla.

The frequency of sister chromatid exchange and cell cycle duration were evaluated simultaneously. This approach is based on the analysis of distribution of cells with differential staining of sister chromatids after treatment of cells with 5-bromodeoxyuridine. The treatment of cells with thiotepa caused no changes in cell cycle duration, while the combination of thiotepa and hydroxyurea (HU) or cytosine-beta-D-arabinofuranoside (ARA-C) was observed to prolong cell cycle duration. Furthermore, it has been shown that caffeine, HU, ARA-C do not increase frequency of sister chromatid exchange in control cells and in cell treated with thiotepa.

[Analysis of the kinetic growth patterns of cultured cells. III. The effect of inoculation density, of a geroprotector-antioxidant and of stationary-phase aging]. / Analiz nekotorykh kineticheskikh zakonomernostei rosta kul'tiviruemykh kletok. III. Vliianie plotnost poseva, geroprotektora-antioksidanta, "statsionarnogo stareniia".

With the help of a previously devised model of cultured cell growth kinetics it was shown that the "plateau" level on the growth curve of human embryo diploid fibroblasts increased, if the cells were grown with Epigid geroprotector-antioxidant (equal results with two drug concentrations: 10(-5) and 10(-7) M, resp.). It was also found that the "plateau" level on the growth curve of cultured "3 days aged" Chinese hamster cells (subcultivated to a fresh medium 3 days after a 1:6 subcultivation) lays higher than the "plateau" level of "14 days aged" cells but lower than that of "7 day aged" cells. Furthermore it was shown that an increase in inoculation density of Chinese hamster cells increased proportionately the rate of cell population growth but had a little effect on the "plateau" level of the growth curve. The data obtained are discussed in terms of some "proliferative" theories of cellular ageing.

[Modeling of induction and elimination of sister chromatid exchanges in time]. / Modelirovanie induktsii i éliminatsii sestrinskikh khromatidnykh obmenov vo vremeni.

Induction and elimination of sister chromatid exchanges (SCE) have been simulated during several cell cycles. Two models of SCE elimination are suggested. The first model postulates that the mutagen-induced lesions are not repaired, a lesion being only inherited by one daughter cell after DNA synthesis. According to the second model, lesions are completely repaired at the first S-phase. No SCE induction takes place during next cell cycles. SCE frequency ranges for both models are described by an equation, including the probability distribution function. The best correspondence in experimental and theoretical results was obtained using the model claiming repair of lesions during one cell cycle.

[Analysis of the kinetic growth patterns of cultured cells. II. The action of ionizing radiation, an alkylating agent and a low-frequency electromagnetic field]. / Analiz nekotorykh kineticheskikh zakonomernostei rosta kul'tiviruemykh kletok. II. Deistvie ioniziruiushchei radiatsii, alkiliruiushchego agents, nizkochastotnogo élektromagnitnogo polia.

With the help of the earlier devised model of cultured cell growth kinetics it is shown that the "plateau" level on the growth curve of Chinese hamster cells decreased proportionally to a dose of the agent applied after a short-term treatment by gamma-radiation or by alkylating agent thiophosphamide. The analysis of our own and literature data enabled us to propose that the lowering of the growth curve may testify to the geropromoter character (i.e. manifesting in ageing promoting) of the investigated factor action. As the low-frequency electromagnetic field induces similar changes in the growth curve, it is related (together with both the above factors investigated) to geropromoters.

[Analysis of the kinetic growth patterns of cultured cells. I. The model]. / Analiz nekotorykh kineticheskikh zakonomernostei rosta kul'tiviruemykh kletok. I. Model'.

On the basis of the Verhulst-Pearl equation, a model of cultured cell growth kinetics is devised. Analysing both authors' and literature data, a possibility was shown to use the model for description of growth kinetics of different cultured cell types. The proposed method of analysis of cell growth kinetic characteristics also provides a rapid evaluation of the cell population doubling time and of the relative number of non-dividing cells in the population.