Tissue breathing and topology of rats thymocytes surface under acute total γ-irradiation. / TKANEVOE DYKhANIE I TOPOLOGIIa POVERKhNOSTI TIMOTsITOV KRYS PRI ODNOKRATNOM OBShchEM γ-OBLUChENII.

OBJECTIVE: Assessment of the effect of single total γ irradiation to the parameters of mitochondrial oxidation and the topology of the thymocyte surface. MATERIALS AND METHODS: The study was performed in sexually mature white outbreeding male rats divided into three groups: two experimental and one control. The states of energy metabolism were determined by the rate of oxygen consumption by the thymus tissues on endogenous substrates at the presence of 2,4 dinitrophenol, uncoupler of a tissue breathing (TB) and oxidative phosphorylation (OP) after a single total γ irradiation at a dose of 1.0 Gy at 3, 10, 40 and 60 days. The topology of thymus cells was assessed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). RESULTS: On the 3rd and 10th days after total gamma irradiation at a dose of 1.0 Gy, a significant decrease in respira tory activity was determined in thymus tissues on endogenous substrates. Simultaneously, on the 3rd day, pro nounced changes in the morphological parameters of thymocytes (height, volume, area of contact with the sub strate) and the topology of their surface were also observed. On the 10th day after irradiation, most of the morpho logical parameters of thymocytes, except for their volume, were characterized by restoration to normal. In the long term (on the 30th and 60th days after exposure), a gradual but not complete recovery of the respiratory activity of thymocytes was observed, accompanied by an increase in the degree of dissociation of TD and OP. CONCLUSIONS: The obtained data reflect and refine mechanisms of post radiation repair of lymphopoiesis, showing the presence of conjugated changes in the parameters of aerobic energy metabolism of thymocytes, morphology and topology of their surface. The synchronism of changes in the parameters under study is a reflection of the state of the cytoskeleton, the functional activity of which largely depends on the level and efficiency of mitochondrial oxidation.

[Chronic recording of scapular movements in quadruped animal (dog)].

The simple and relatively non-traumatic method of attaching the sensor to the scapular for chronic recording the scapula movements with magnetic tracking device is presented. During experiment the sensor fixed to the skin with the nylon thread passing through the m. deltoideus in the middle part of the scapula. This method provided stable recording of the scapular movements, shown in four dogs with previously learned coordination of head and forelimb movements.

[Surface architectonics and cytoskeleton state of different age rats' thymocytes exposed to peroxynitrite].

To reveal the role of aging in the changes of immune system cells response to proinflammatory (oxidizing) agent we have studied peroxynitrite (30 microM) influence on the cell surface layer structure of different age rats' thymocytes. In the absence of proinflammatory agent, there were no significant changes in morphological and topological parameters of thymocytes from the rats at 3 and 8 months of age. According to atomic force microscopy data, peroxynitrite stimulates actin cytoskeleton structures assembly in thymocytes from 3-month rats but inhibits it in cells from 8-month rats. Obtained results make clear the difference between the immune system responses in inflammatory processes of young and old organisms.

[The use of summary indices for assessing organochlorine compounds in water]. / Ispolzovanie summarnykh pokazatelei dlia otsenki khlororganicheskikh soedinenii v pitevoi vode.

Adsorption of chlorinated organic compounds (COC) on activated charcoal and determination of ionic chlorine by gas chromatography were used for assessment of water pollution by COC. Content of adsorbing COC was the following (micrograms CI-/l): in river water 10-470, in drinking water 10-1180, in underground water 90-150; content of volatile COC was (micrograms CI-/l): in drinking water 2-117, in underground water 14-16.

[A mathematical model of the development of dental caries]. / Matematicheskaia model' razvitiia kariesa zubov.

A mathematical model is suggested, simulating the development of carious process in a tooth, based on an analytical approach. The process of hydrogen ions diffusion into enamel microspaces is described via transport equation. A simplified model explaining the formation of the involvement of the body of the tooth under the enamel surface at the initial stages of caries development is described in detail. Analysis has shown that the theoretical model is in good correlation with experimental data on the rate of chemical reaction of Ca radionuclide accumulation in the enamel surface and deeper layers.

[Hybridization of asporogenic strains of Hansenula polymorpha yeasts by protoplast fusion]. / Gibridizatsiia asporogennykh shtammov drozhzhei Hansenula polymorpha putem sliianiia protoplastov.

Intrastrain and interstrain hybrids of different ploidy were produced by the fusion of protoplasts of Hansenula polymorpha haploid and diploid strains. The diploid hybrids were found to be stable in contrast to the triploid and tetraploid hybrids. The instability of the triploid and tetraploid states in Hansenula polymorpha was expressed in the elevated frequency of spontaneous formation of auxotrophic markers and in the decreased content of DNA per cell in the course of storage.