Isotopic Composition of Blood of Polar Bears (Ursus maritimus) of the Kara-Barents Sea Population.

The data on the content of carbon and nitrogen isotopes in the blood samples of polar bears obtained in the present study confirm that polar bears in the Taimyr region (and the Kara-Barents sea population in general) are partly dependent on the resources of terrestrial origin. However the "terrestrial carbon" evidently reaches bears' tissues indirectly, via marine food webs utilizing organic carbon brought into the polar basin by Siberian rivers.

Movement of a female polar bear (Ursus maritimus) in the Kara Sea during the summer sea-ice break-up.

The polar bear movement trajectory in relation to onset date of the sea-ice break-up was studied in the coastal zone of the Taimyr Peninsula, eastern part of the Kara Sea, using as an example a female polar bear tagged by a radio collar with an Argos satellite transmitter. Analysis of the long-term pattern of ice melting and tracking, by means of satellite telemetry, of the female polar bear who followed the ice-edge outgoing in the north-eastern direction (in summer 2012) suggests that direction of the polar bear movement depends precisely on the direction of the sea-ice cover break-up.

[The effect of poly(3-hydroxybutyrate) modification by poly(ethylene glycol) on the viability of cells grown on the polymer films].

A biodegradable polymer of bacterial origin, poly(3-hydroxybutyrate) (PHB), is intensively studied as biomaterial for tissue engineering. However, factors determining its biocompatibility still require better understanding. To analyze the PHB films biocompatibility, the polymer material was modified by hydrophilic polymer, poly(ethylene glycol) 300 (PEG). The blends PHB/PEG with different PEG content (10, 20, 30 and 50%) were produced by subsequent incubation in water resulted in removal of 95% PEG. The surface roughness and hydrophilicity were studied by atomic force microscopy (AFM) and contact angle "water-polymer" measurement, respectively. The film biocompatibility on cell culture of COS-1 fibroblasts was studied in vitro. It was shown that both roughness and hydrophobicity are directly proportional to initial PEG content in the PHB/PEG blends. The growth rate of COS-1 fibroblasts on polymer films is determined by combination of two basic physicochemical properties of the polymer surface: the roughness and hydrophilicity. The optimal roughness requred for COS-1 cells growth is the average roughness more than 25 nm, whereas the limit values of the contact angle "water-polymer" that was responsible for relatively high cell viability were not found. These data indicate that the film surface roughness had the greatest effect on the cell growth, whereas the increase in the polymer surface hydrophilicity caused the additional positive effect on viability of attached cells. Thus, the modification of PHB polymer material by PEG resulted in the improved viability of cells cultivated on the polymer films in vitro. The obtained data can be used for development of such medical devices as surgeon patches and periodontal membranes.

[Activity of the hypothalamo-pituitary-adrenals axis in the Siberian tiger (Panthera tigris altaica) in captivity and in the wild, and their dynamics throughout the year].

A noninvasive evaluation method of hypothalamo-pituitary-adrenals axis (HPA) activity in the Siberian tiger was verified. Comparison of the activity level of HPA in Siberian tigers in the wild and in captivity, and their alterations over the year was carried out. Significant seasonal deviations between activity levels of HPA in tigers in captivity were not found. In the wild, this level was significantly higher, reaching the maximum from November to January, which can be related with an unfavorable influence on tigers in low temperatures and deep snow cover.

[Study of photodynamic treatment for P-388 lympho-leukemia in mice].

Data are presented on the results of photodynamic treatment (PDT) of mice DBA2 with transplantable lympho-leukemia P-388. Different regimens of photosensitizer Dimegin and emission were used. Both intravenous PDT and in combination with local PDT should be recommended.

[Biosynthesis of poly-3-hydroxybutyrate-3-hydroxyvalerate copolymer by Azotobacter chroococcum strain 7B].

The ability of Azotobacter chroococcum strain 7B, producer of polyhydroxybutyrate (PHB), to synthesize its copolymer poly-3-hydroxybutyrate-3-hydroxyvalerate (PHB-HV) was studied. It was demonstrated, for the first time, that A. chroococcum strain 7B was able to synthesize PHB-HV with various molar rates of HV in the polymer chain when cultivated on medium with sucrose and carboxylic acids as precursors of HV elements in the PHB chain, namely, valeric (13.1-21.6 mol %), propanoic (3.1 mol %), and hexanoic (2.1 mol %) acids. Qualitative and functional differences between PHB and PHB-HV were demonstrated by example of the release kinetic of methyl red from films made of synthesized polymers. Maximal HV incorporation into the polymer chain (28.8 mol %) was recorded when the nutrient medium was supplemented with 0.1% peptone on the background of 20 mM valerate. These results suggest that that the studied strain can be regarded as a potential producer of not only PHB but also PHB-HV.

[A comparative study of biodegradation kinetics of biopolymer systems based on poly(3-hydroxybutyrate)].

The aim of this study was to evaluate and to compare of long-term kinetics curves of biodegradation of poly(3-hydroxybutyrate) (PHB), its copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and PHB/polylactic acid blend. The total weight loss and the change of average viscosity molecular weight were used as an index of biodegradation degree. The rate of biodegradation was analyzed in vitro in presence oflipase and in vivo when the films were implanted in animal tissues. The morphology of PHB films surface was studied by atomic force microscopy technique. It was shown that biodegradation of PHB is occurred by means of as polymer hydrolysis, and as its enzymatic biodegradation. The obtained data can be used for development of medical devices on the base of PHB.

[Biological effects of Lamipharen photodynamic therapy].

Biological effects of Lamipharen treatment of sarcoma M-1 was studied in newborn rats and photodynamic therapy in combination with radiation was evaluated.

[Use of photosense treatment to enhance photodynamic effect on solid sarcoma-1 in Wistar rats].

Interaction between such components of photodynamic therapy as tumor, intact tissues, lighting and photosensitizers has been investigated. The efficacy of Photosense treatment was demonstrated in the experiments using transplantable tumors in Wistar rats. The photodynamic procedure both inhibited tumor process and stimulated immune system.

[Surgical stress: clinical-and-laboratory parallels under activation of the natural stress-limiting systems]. / Khirurgicheskii stress. Kliniko-laboratornye paralleli v usloviiakh aktivatsii estestvennykh stress-limitiruiushchikh sistem.

Three hundred and eighty-seven patients, who were operated on the scheduled basis for different surgical pathologies, were examined. The purpose of the case study was definition of the clinical-and-laboratory parallels related with pronouncement of surgical stress in an advanced variation of neuroleptanalgesia.

[Time course of changes in tuberculosis epidemiological parameters in Iakutia over 12 years (1983-1994)]. / Dinamika osnovnykh épidemiologicheskikh pokazateleí tuberkuleza v Iakutii za 12 let (1983-1994gg).

In the past 12 years, there were 1.3- and 1.9-fold reductions in the total morbidity rates of tuberculosis and its spread, respectively. However, its morbidity among children showed 3-fold increases. The reduction rate of bacterial excretion became much slower in the past 4 years. Tuberculosis mortality rates tended to rise. At the moment of study, the basic tuberculosis epidemiological parameters were 1.3-1.5 times higher than those in the Russian Federation. At the same time there was a decrease in the efficiency of antituberculous work at all levels.

[Recurrence of pulmonary tuberculosis in adults in the areas of the Republic of Sakha (Iakutia)]. / Retsidivy tuberkuleza legkikh u vzroslykh v ulusakh Respubliki Sakha (Iakutia).

The dynamics in recurrences of pulmonary tuberculosis was analyzed in the areas of Yakutia. The social and clinical characteristics of patients with recurrences and their treatment outcomes are presented in the paper. Recurrences of pulmonary tuberculosis were found to occur more frequently in the areas having a poor epidemiological tuberculosis situation and among socially unprotected groups of the population. Under these conditions, recurrences may occur in 30 years or more after clinical cure of tuberculosis. To treat patients with recurrences in the area presents great difficulties.

[Immune reactivity indices of workers in the manufacture of viscose]. / Nekotorye pokazateli immunnoi reaktivnosti u rabochikh viskoznoi promyshlennosti.

A total of 300 workers engaged in viscose industry were examined for leukocyte blast transformation, spontaneous and complement rosette-formation, blood serum immunoglobulins, bactericidal activity of blood serum, lysozyme titre, phagocytic activity of neutrophils, and the NBT test. The data obtained attest to the changes in the total nonspecific body responsiveness of the workers examined. The character and degree of the changes in cellular and humoral immunity were marked by cycles, depending on the workers' record. The changes in the total nonspecific responsiveness were found to persist for a long time even after discontinuation of the contact with carbon disulfide.