COMPARATIVE EFFECT OF FUCOIDAN FROM ALGA FUCUS VESICULOSUS AND ITS FRACTIONS, OBTAINED BY ANION-EXCHANGE CHROMATOGRAPHY, ON CELL LINES HeLa G-63, Hep G2 AND CHANG LIVER.

The aim of the present study was to compare the effect of sulfated fucopolysaccharides isolated from Fucus vesiculosus on cell lines HeLa G-63, Hep G2 and Chang liver. Native fucoidan F3 and two fractions (F3-0.5 and F3-1), obtained by anion-exchange chromatography, were analyzed using chemical methods and IR-spectroscopy. Their action on cells demonstrates that F3 and F3-1, characterized by higher content of sulfates, preferable location of sulfo-groups at C4 atom of fucose residue and low content of uronic acids, inhibit cell proliferation more efficiently. Human liver tumor cells Hep G2 appeared to be the most sensitive to fucoidan treatment whereas nonmalignant human cells Chang liver were the least sensitive.

[EFFECT OF FUCOIDANS ISOLATED FROM SEAWEEDS LAMINARIA DIGITATA AND FUCUS VESICULOSUS ON CELL LINES HELA G-63, ECV 304 AND PC 12].

The aim of the research was to investigate cytotoxicity of fucoidans on mammals cells. Three different samples of fucoidans were isolated from mechanically grounded brown algae Laminaria digitata and Fucus ve- siculosus. The sample F2 that differed from the others by higher sulfatation level and suppression of HeLa G-63 line culture growth was taken for further study in cell lines HeLa G-63, ECV 304 and PC 12. We have shown that fucoidan preparation F2 inhibits proliferation and induces cell death in a dose- and time-dependent manner for all investigated cell lines. Neuroendocrine tumor rat cell line PC 12 appeared to be the most sensitive to fucoidan treatment whereas endothelial human cells ECV 304 were the least sensitive.

[Assessing of the role superoxide, nitric oxide and redox metals in cytotoxic effect of the H2O2 and amyloid-beta-protein].

On the cells of neuroendocrine tumor of rats (line PC12) in culture was estimating of the governing mechanisms of the cytotoxicity of the oxidative stress and the role of the amyloids in increasing this stress. Using flowcytometric assessment of the cytotoxicity H2O2 and fragment beta-amyloid (Abeta) peptide (25-35) has been shown the dose-dependent increasing of the quote of the cells with DNA content < 2c. Isoeffective consentrations were 1 MM H2O2 and 5 MkappaM Abeta. The cytotoxicity H2O2 and A were accompanig with the increasing of the intracellular level of O2-. The treatment of the cells GSNO (donor of NO) and o-phenantrolin (chelators of Fe ions) significantly decreased the intracellular level of O2- as well as the cytotoxicity H2O2 and Abeta. Thus, in direct experiments has been shown of the part amyloids in the increasing of the oxidative stress and participation of the reactive oxide radicals in the cytotoxic effect of the Abeta. The addition argument which confirmed contribution of the oxidative stress in the cytotoxic effect of the Abeta was the similarity of the cellular response on the action of the oxidative agent - H2O2 and Abeta.

Intracellular NO concentration and its changes in carcinoma cells and cultured human endotheliocytes under the influence of inhibitors and inductors of nitric oxide synthases.

We carried out cytophotometric evaluation of NO content in cells expressing various types of NO synthases. Endogenous production of NO can be modified by NO synthase inductors and inhibitors.

[The blocking of the proliferation of the human endothelial cells in culture by beta-irradiation from internal and external sources of the radiation. S-block is induced by the 3H2O beta-particles].

Recently we shown that low doses (0.12-0.46 Gy) of (methyl-3H)-thymidine incorporated into human endothelial cells induce the accumulation cells in G2-phase of the cell cycle. The temperate doses of (1-6 Gy) gamma-rays 137Cs were less effective in the induction of the G2-block estimated by flow cytometry analysis of DNA content and in the induction of the chromosome aberrations (bridges and fragments in anaphase). The aim of this study was the comparative investigation of efficiency of beta-rays emitted 3H from 3H-thymidine and 3H2O by several of the cellular parameters. Here we shown that at the equal conditions of the incubation of the cells in medium with 3H2O induced the accumulation cells in S-phase without decreasing of the mitotic activity and without increasing of the chromosome aberrations level. Unlike from 3H2O the incubation of the cells with 3H-thymidine induced the accumulation cells in G2-phase with decrease of the mitotic activity and with increase of the chromosome aberrations level. Concurrent treatment cells with 3H-thymidine and thymidine abrogate these cellular effects of the 3H-thymidine. Inhibitor ATM-kinase caffeine abrogate as G2-block as S-phase block. These results suggest that the low-dose beta-radiation activates S-phase and G2-phase checkpoints requiring ATM-mediated signal transduction pathway. The factors, which impact on the efficiency of the internal and of the external sources of the irradiation, depend on theirs disposition in relation to radiosensitive target--DNA was discussed.

[Internal and external sources of the radiation induce the blocking of the proliferation of the human endothelial cells in culture. G2-block is induced by beta-particle 3H-thymidine and gamma-rays 137Cs].

We found that low doses (0.12-0.46Gy) of (methyl-) 3H-thymidine incorporated into human endothelial cells induce the accumulation cells in G2-phase of the cell cycle. Temperate doses of (1-6 Gy) gamma-rays 137Cs were less effective in the G2-block estimated by flow cytometry analysis of DNA content. Furthermore, the induced the high level of the chromosome aberrations (bridges and fragments in anaphases). 1Gy of gamma-ray 137Cs and 0.005 Gy of beta-rays induced the same per cent of the aberrant anaphases. Apparently, that the damages of the cellular hereditary structures are responsible for the blocking of the cellular proliferation in G2-phase. We suggest, that the disposition 3H-thymidine into radiosensitive target (DNA) defines the high cytotoxic of the beta-rays.

Observation of interaction forces between one-dimensional spatial solitons in photorefractive crystals.

We propagate two coherent and parallel beams of a He-Ne laser through a Bi(12)TiO(20) photorefractive crystal in the presence of drift nonlinearity. Our experimental results demonstrate that the beams attract or repel each other according to their initial phase difference. They attract each other when they are initially in phase and they repel each other when they are initially out of phase. These experimental results agree with numerical predictions recently published.

Karyotyping of individual cells with flow cytometry.

As the study of metaphase chromosomes with flow cytometry presupposes mixing all chromosomes from many cells before analysis, important information is lost. To overcome this limitation we have developed a novel cell-oriented flow cytometric method for chromosome analysis. A flow cytometer supplied with a special device for disruption of metaphase chromosomes is the heart of the method. Cells with stained chromosomes are pressed into the disruption device and then converted in batches of chromosomes. Chromosome fluorescence and time intervals between fluorescence pulses are registered. There are large time intervals between neighboring batches because a sparse cell suspension is used and, in turn, there are small time intervals inside batches. Taking account of time intervals, it is possible to identify individual cell flow karyotypes. This highly productive method for individual cell analysis (100-200 cells/min) ensures detecting the changes in cell flow karyotypes, i.e., under- and overrepresentation of chromosomes, aberrations, and amplification of DNA.

Experimental evidence of modulation instability in a photorefractive Bi(12)TiO(20) crystal.

We present experimental results on the propagation of an interference pattern of two He-Ne laser beams of unequal amplitudes through a photorefractive Bi(12)TiO(20) crystal in the presence of drift nonlinearity. The phenomenon that we have observed is the focusing of the fringes as the nonlinearity of the crystal is increased. We show that such a phenomenon can be quantitatively interpreted in the framework of modulation instability theory.

Sensitivity of non-steady-state photoelectromotive force-based adaptive photodetectors and characterization techniques.

The light-to-electricity conversion efficiency of the non-steady-state photoelectromotive force effect and its threshold sensitivity for the detection of phase-modulated optical signals and space-charge electric fields are evaluated. It is shown that for the optimal conditions of operation (the carrier spatial frequency is equal to the inverse diffusion length of the photocarriers, the detected frequency is higher than the cutoff frequency of the electromotive force signal, and the load resistance is higher than the resistance of the sample), the generation-recombination noise is approximately equal to the thermal noise of the sample resistance. In this case the threshold sensitivity of the adaptive photodetector without an external dc bias is independent of the parameters of the crystal used and can be only 4√2 times lower than that caused by the generation-recombination noise in a conventional photoresistor. Unlike in photodiodes and photoresistors, the output noise caused by laser intensity fluctuations is of the multiplicative type in the adaptive photodetectors.

[The production of clones of "man x Chinese hamster" hybrid cells containing different parts of the human genome]. / Poluchenie klonov gibridnykh kletok "chelovek x kitaiskii khomiachok", soderzhashchikh raznye chasti genoma cheloveka.

Some approach has been described to create hybrid cell lines (human x Chinese hamster) which contain different parts of human genome, and then efficiently to reveal and isolate the human DNA from these. This method involves the introduction of a selective marker in different sites of the human cell genome, by transfecting them with plasmid SV2neo, and the use of flow cytometry and DNA polymerase chain reaction with primers specific only for human DNA.

Detection of optical signals with high-amplitude phase modulation by adaptive photodetectors.

Results of a detailed theoretical analysis on the detection of phase-modulated optical signals with an arbitrary modulation index (Delta >< 1) and modulation frequency (omega/omega(0) >< 1, where omega(0) is the characteristic cutoff frequency) by adaptive photodetectors that are based on photorefractive crystals and the nonsteady- state photo-electromotive force are presented. Besides general analytical results, numerical calculations of the output signal form and the amplitude and the phase of its first and second harmonics are given. The main predictions of the theoretical analysis are illustrated by the experimental data obtained for a high-sensitivity cubic photorefractive Bi(12)SiO(20) crystal at the wavelength (lambda = 488 nm) of an argon-ion laser.

Noise and sensitivity characteristics of Bi(12)SiO(20) crystals for optimization of a real-time self-diffraction holographic interferometer.

The optimization of a real-time holographic interferometer that uses photorefractive Bi(12)SiO(20) crystals as the recording media through anisotropic self-diffraction is considered with regard to the optical noise and sensitivity characteristics of two particular crystals. A simple theoretical treatment is given to describe the factors influencing the maximum area of an object that can be viewed interferometrically by using these crystals. Experimental values of the noise distribution and sensitivity of the crystals are presented and used to obtain a value for the maximum observable object area of the order of 1 m(2).

Measuring vibration amplitudes in the picometer range using moving light gratings in photoconductive GaAs:Cr.

We report the measurements of picometer vibration amplitudes produced by a piezo mirror in an interferometric setup, using a GaAs:Cr photoconductive device. The moving light fringes (gratings) induce in this new detector periodic photocurrents characterized by efficient suppression of the low-frequency drifts of the working point and low sensitivity to the amplitude laser noise. The optimum operation conditions of this system are also shown.

[Cell-by-cell flow cytometric analysis of chromosomes]. / Pokletochnyi protochnotsitometricheskii analiz khromosom.

The authors discuss various aspects of a recently developed method permitting a detailed flow cytometric analysis of the individual cell karyotypes such as instrumentation, histochemistry, data proceeding algorithms. Possible drawbacks of the method and the ways of their overcoming are considered. Results of analysis of the Chinese hamster cells are presented that illustrate the possibilities of the method, including the metaphase chromosome distribution according to their fluorescence intensity, the analysed cell distribution according to their chromosomes number, the table in which the individual cell karyotypes are distributed according to their fluorescence. The results obtained show that the developed method may be successfully used for investigating chromosomal iNstability and heterogeneity of the mammalian cells.

Double phase-conjugate mirror using a photorefractive Bi(12)TiO(20) crystal.

Experimental results are reported for four-wave mixing at 633 nm with a photorefractive Bi(12)TiO(20) crystal in a double phase-conjugate mirror geometry. Recording in the presence of an alternating electric field with optimum focusing of interacting Gaussian beams yields up to 40% diffraction efficiency for the hologram.

[Reproducible chromosomal instability of an established Chinese hamster cell line detectable by flow cytometry]. / Vosproizvodimaia nestabil'nost' khromosom postoiannoi linii kletok kitaicheskogo khomiachka, vyiavliaemaia s pomoshch'iu protochnoi tsitometrii.

The karyotypes of individual cells in clones of the established Chinese hamster cell line display a highly heterogeneous pattern. Unlike situation in individual cells, the flow karyotypes of cloned cell populations are very similar. A comparison of these facts suggests that mostly the same certain chromosomal reorganizations, appearing frequently enough, may occur in the cells. As a result, the whole set of possible variants of reorganized chromosomes appear during few cell cycles, regardless of the initial cell karyotype. This hypothesis is supported by our flow cytometry data. The same small peaks corresponding to rarely met (less than 1 per cell) rear ranged chromosomes appear on flow karyotype histograms of parental cell clones and their secondary subclones. Chromosomes with random gamma or UV irradiation-induced reorganizations do not remain in the cell population, unlike certain reorganization of regular nature.

[Mechanism of the radioprotective effect of cysteamine]. / K voprosu o mekhanizme radiozashchitnogo deistviia tsisteamina.

The radioprotective effect of cysteamine combined with the modification of the chromatin state by sodium butyrate has been studied using V-79 and CHEL lines of Chinese hamster cells and HeLa cells. Sodium butyrate enhances the chromatin sensitivity to nucleases and removes the radioprotective effect of cysteamine as measured by the yield of cells with chromosome aberrations. As is indicated by changes in the intensity of fluorescence of the DNA-ethidium bromide complex, measured by laser flow cytometry, the protective agent decreases the binding of the dye with both irradiated and nonirradiated DNA whereas ionizing radiation and sodium butyrate increase thereof. It is concluded that the radioprotective effect of cysteamine depends in its ability to reduce the susceptibility of DNA to nucleases.

[Constancy of the circadian system of the body]. / Konstantnost' tsirkadiannoi sistemy organizma.

With respect to the biorhythmological selection of cosmonauts the concept of the biorhythmological status is understood as a sum total of biorhythmological properties of the human body. Two components of the biorhythmological properties of the human body. Two components of the biorhythmological status--constancy and lability of the circadian system--are described. Their interaction is discussed from the point of view of the hierarchical principle of the arrangement of the circadian system. Certain methods of quantitative evaluation of constancy of circadian rhythms are presented. Particular attention is given to the assessment of stability of the position of circadian rhythms on the 24-hour scale.