105 research outputs found

    Possibility of using the SBE profilometer data for calibration of satellite data on concentration of chlorophyll <i>a</i> in the Japan Sea

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    Chlorophyll a (Chl) concentration in the upper 100 m layer of the northwestern Japan Sea is measured both by fluorimeter Wetlabs mounted on oceanographic sonde-profilometer SBE 911 and by standard spectrophotometric method in the 1st Russian-Chinese survey in the autumn of 2010. Biomass and species composition of phytoplankton at the seas surface are determined in the same time. For the whole area of measurements, the data on Chl defined by two methods correlate weakly (R2 = 0.22). However, after dividing the investigated area onto five local areas taking into account oceanographic patterns and satellite data on Chl concentration (8-day composite images), the correlation becomes higher for any local area (R2 from 0.57 to 0.91). Inclination of regression between the data measured by two methods (ratio fluorescence : concentration) varies between the areas, as well - from 0.76 above the continental slope of middle Primorye to 1.70 at Kito-Yamato Bank. This variability is reasoned by variations of both oceanographic conditions and species composition of phytoplankton. Instability of Chl fluorescent ability should be considered when satellite data on Chl concentration are used

    Влияние препарата «Кумазид» на функциональное состояние внутренних органов крыс

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    An investigation of Kumazid medication influence on functional condition of experimental animal main organs and and systems, that were subjected to intragastric injection during three monthes, was made. It was determined that the Kumasid medication dosed 1—100 mkg/kg administrated to rats intragastically during three monthes doesn’t change internal conditions of lab animals.Проведено исследование влияния препарата «Кумазид» на функциональное состояние основных органов и систем при длительном (3-месячном) внутрижелудочном введении препарата экспериментальным животным. Установлено, что препарат «Кумазид» при 3-месячном курсе внутрижелудочного введения крысам в дозах 1-100 мкг/кг массы тела не оказывает достоверных изменений состояния внутренних органов лабораторных животных

    Intestinal Epithelial Serum Amyloid A Modulates Bacterial Growth In Vitro and Pro-Inflammatory Responses in Mouse Experimental Colitis

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    <p>Abstract</p> <p>Background</p> <p>Serum Amyloid A (SAA) is a major acute phase protein of unknown function. SAA is mostly expressed in the liver, but also in other tissues including the intestinal epithelium. SAA reportedly has anti-bacterial effects, and because inflammatory bowel diseases (IBD) result from a breakdown in homeostatic interactions between intestinal epithelia and bacteria, we hypothesized that SAA is protective during experimental colitis.</p> <p>Methods</p> <p>Intestinal SAA expression was measured in mouse and human samples. Dextran sodium sulfate (DSS) colitis was induced in SAA 1/2 double knockout (DKO) mice and in wildtype controls. Anti-bacterial effects of SAA1/2 were tested in intestinal epithelial cell lines transduced with adenoviral vectors encoding the CE/J SAA isoform or control vectors prior to exposure to live <it>Escherichia coli</it>.</p> <p>Results</p> <p>Significant levels of SAA1/SAA2 RNA and SAA protein were detected by in situ hybridization and immunohistochemistry in mouse colonic epithelium. SAA3 expression was weaker, but similarly distributed. SAA1/2 RNA was present in the ileum and colon of conventional mice and in the colon of germfree mice. Expression of SAA3 was strongly regulated by bacterial lipopolysaccharides in cultured epithelial cell lines, whereas SAA1/2 expression was constitutive and not LPS inducible. Overexpression of SAA1/2 in cultured epithelial cell lines reduced the viability of co-cultured <it>E. coli</it>. This might partially explain the observed increase in susceptibility of DKO mice to DSS colitis. SAA1/2 expression was increased in colon samples obtained from Crohn's Disease patients compared to controls.</p> <p>Conclusions</p> <p>Intestinal epithelial SAA displays bactericidal properties in vitro and could play a protective role in experimental mouse colitis. Altered expression of SAA in intestinal biopsies from Crohn's Disease patients suggests that SAA is involved in the disease process..</p

    Sterol and Sphingoid Glycoconjugates from Microalgae

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    Microalgae are well known as primary producers in the hydrosphere. As sources of natural products, microalgae are attracting major attention due to the potential of their practical applications as valuable food constituents, raw material for biofuels, drug candidates, and components of drug delivery systems. This paper presents a short review of a low-molecular-weight steroid and sphingolipid glycoconjugates, with an analysis of the literature on their structures, functions, and bioactivities. The discussed data on sterols and the corresponding glycoconjugates not only demonstrate their structural diversity and properties, but also allow for a better understanding of steroid biogenesis in some echinoderms, mollusks, and other invertebrates which receive these substances from food and possibly from their microalgal symbionts. In another part of this review, the structures and biological functions of sphingolipid glycoconjugates are discussed. Their role in limiting microalgal blooms as a result of viral infections is emphasized

    Carbohydrate-Containing Low Molecular Weight Metabolites of Microalgae

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    Microalgae are abundant components of the biosphere rich in low molecular weight carbohydrate-containing natural products (glycoconjugates). Glycoconjugates take part in the processes of photosynthesis, provide producers with important biological molecules, influence other organisms and are known by their biological activities. Some of them, for example, glycosylated toxins and arsenicals, are detrimental and can be transferred via food chains into higher organisms, including humans. So far, the studies on a series of particular groups of microalgal glycoconjugates were not comprehensively discussed in special reviews. In this review, a special focus is given to glycoconjugates’ isolation, structure determination, properties and approaches to search for new bioactive metabolites. Analysis of literature data concerning structures, functions and biological activities of ribosylated arsenicals, galactosylated and sulfoquinovosylated lipids, phosphoglycolipids, glycoside derivatives of toxins, and other groups of glycoconjugates was carried out and discussed. Recent studies were fundamental in the discovery of a great variety of new carbohydrate-containing metabolites and their biological activities in defining the role of microalgal viral infections in regulating microalgal blooms as well as in the detection of glycoconjugates with potent immunomodulatory properties. Those discoveries support growing interest in these molecules

    Marine Excitatory Amino Acids: Structure, Properties, Biosynthesis and Recent Approaches to Their Syntheses

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    This review considers the results of recent studies on marine excitatory amino acids, including kainic acid, domoic acid, dysiherbaine, and neodysiherbaine A, known as potent agonists of one of subtypes of glutamate receptors, the so-called kainate receptors. Novel information, particularly concerning biosynthesis, environmental roles, biological action, and syntheses of these marine metabolites, obtained mainly in last 10&ndash;15 years, is summarized. The goal of the review was not only to discuss recently obtained data, but also to provide a brief introduction to the field of marine excitatory amino acid research

    Carbohydrate-Containing Marine Compounds of Mixed Biogenesis

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    Marine natural compounds, containing rare and enzymatically-modified monosaccharide residues [...

    Adaptive abilities of microscopic red alga <i>Porphyridium purpureum</i> (strain PP-AB11) under change of salinity in the medium

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    Adaptive abilities of the microscopic red alga Porphyridium purpureum (strain PP-AB11, isolated from the northwestern Japan Sea) are investigated experimentally by its repeated cultivation under various water salinity. Under the salinity of 8 ‰, the growth of P. purpureum was inhibited (0.1 division/day) during the first four days though there were no morphological differences of the cells as compared with those in the control (mean cell size was 6.3±1.2 µm in both cases); the cell density increased to 85 % of the control value after 21 days exposure. Under the salinity of 4 ‰, the lag-phase was also 4 days but size of the cells increased (on average up to 7.8 ± 1.5 µm), the cell morphology changed including the cytoplasm retraction, and contraction and granulation of the chloroplasts; the cell density increased less (to 53 % of the control value) after 21 days exposure. Under the salinity of 2 ‰, changes of the cell morphology and density were the most prominent: density of viable cells decreased to 6 % of the control value after 4-days exposure, size of the cells increased on average up to 8.7 ± 1.6 µm due to hydration, granulation was noticed in the chloroplasts, and the cytoplasm became dense. Under the salinity of 0 ‰, all the cells died after 4 days. Being cultivated repeatedly, the alga was better adapted to low salinity: after 21-days exposure the cell density was 97 % of the control value under salinity of 8 ‰ and 84 % of the control value under salinity of 4 ‰, with the growth rate 0.5 divisions/day and without visible morphological differences of the cells as compared with those in the control. It was adapted even to salinity of 2 ‰: the cells morphology was restored though the growth rate after 21-days exposition was still lower than in the control because of serious deterioration of the cells. The growth rate and cell morphology did not significantly differ from the control after reinoculation of the culture, previously adapted to salinity of 2 ‰, into the medium with salinity of 32 ‰
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