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Sample records for subglacial metabolic activity

  1. Antarctic Active Subglacial Lake Inventory from ICESat Altimetry, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains lake boundaries, volume changes, and gridded elevations for 124 active subglacial lakes beneath the Antarctic ice sheet. Lakes were identified...

  2. Potential Activity of Subglacial Microbiota Transported to Anoxic River Delta Sediments

    DEFF Research Database (Denmark)

    Cameron, Karen A.; Stibal, Marek; Olsen, Nikoline S.

    2017-01-01

    The Watson River drains a portion of the SW Greenland ice sheet, transporting microbial communities from subglacial environments to a delta at the head of Søndre Strømfjord. This study investigates the potential activity and community shifts of glacial microbiota deposited and buried under layers...... shift in predominant community members and a decline in diversity and cell abundance. These results highlight the need for further investigations into the fate of subglacial microbiota within downstream environments.......The Watson River drains a portion of the SW Greenland ice sheet, transporting microbial communities from subglacial environments to a delta at the head of Søndre Strømfjord. This study investigates the potential activity and community shifts of glacial microbiota deposited and buried under layers...... of sediments within the river delta. A long-term (12-month) incubation experiment was established using Watson River delta sediment under anaerobic conditions, with and without CO2/H2 enrichment. Within CO2/H2-amended incubations, sulphate depletion and a shift in the microbial community to a 52% predominance...

  3. Actively evolving subglacial conduits and eskers initiate ice shelf channels at an Antarctic grounding line

    Science.gov (United States)

    Drews, R.; Pattyn, F.; Hewitt, I. J.; Ng, F. S. L.; Berger, S.; Matsuoka, K.; Helm, V.; Bergeot, N.; Favier, L.; Neckel, N.

    2017-05-01

    Ice-shelf channels are long curvilinear tracts of thin ice found on Antarctic ice shelves. Many of them originate near the grounding line, but their formation mechanisms remain poorly understood. Here we use ice-penetrating radar data from Roi Baudouin Ice Shelf, East Antarctica, to infer that the morphology of several ice-shelf channels is seeded upstream of the grounding line by large basal obstacles indenting the ice from below. We interpret each obstacle as an esker ridge formed from sediments deposited by subglacial water conduits, and calculate that the eskers' size grows towards the grounding line where deposition rates are maximum. Relict features on the shelf indicate that these linked systems of subglacial conduits and ice-shelf channels have been changing over the past few centuries. Because ice-shelf channels are loci where intense melting occurs to thin an ice shelf, these findings expose a novel link between subglacial drainage, sedimentation and ice-shelf stability.

  4. Actively evolving subglacial conduits and eskers initiate ice shelf channels at an Antarctic grounding line.

    Science.gov (United States)

    Drews, R; Pattyn, F; Hewitt, I J; Ng, F S L; Berger, S; Matsuoka, K; Helm, V; Bergeot, N; Favier, L; Neckel, N

    2017-05-09

    Ice-shelf channels are long curvilinear tracts of thin ice found on Antarctic ice shelves. Many of them originate near the grounding line, but their formation mechanisms remain poorly understood. Here we use ice-penetrating radar data from Roi Baudouin Ice Shelf, East Antarctica, to infer that the morphology of several ice-shelf channels is seeded upstream of the grounding line by large basal obstacles indenting the ice from below. We interpret each obstacle as an esker ridge formed from sediments deposited by subglacial water conduits, and calculate that the eskers' size grows towards the grounding line where deposition rates are maximum. Relict features on the shelf indicate that these linked systems of subglacial conduits and ice-shelf channels have been changing over the past few centuries. Because ice-shelf channels are loci where intense melting occurs to thin an ice shelf, these findings expose a novel link between subglacial drainage, sedimentation and ice-shelf stability.

  5. Physiological ecology of microorganisms in Subglacial Lake Whillans

    Directory of Open Access Journals (Sweden)

    Trista J Vick-Majors

    2016-10-01

    Full Text Available Subglacial microbial habitats are widespread in glaciated regions of our planet. Some of these environments have been isolated from the atmosphere and from sunlight for many thousands of years. Consequently, ecosystem processes must rely on energy gained from the oxidation of inorganic substrates or detrital organic matter. Subglacial Lake Whillans (SLW is one of more than 400 subglacial lakes known to exist under the Antarctic ice sheet; however, little is known about microbial physiology and energetics in these systems. When it was sampled through its 800 m thick ice cover in 2013, the SLW water column was shallow (~2 m deep, oxygenated, and possessed sufficient concentrations of C, N, and P substrates to support microbial growth. Here, we use a combination of physiological assays and models to assess the energetics of microbial life in SLW. In general, SLW microorganisms grew slowly in this energy-limited environment. Heterotrophic cellular carbon turnover times, calculated from 3H-thymidine and 3H-leucine incorporation rates, were long (60 to 500 days while cellular doubling times averaged 196 days. Inferred growth rates (average ~0.006 d-1 obtained from the same incubations were at least an order of magnitude lower than those measured in Antarctic surface lakes and oligotrophic areas of the ocean. Low growth efficiency (8% indicated that heterotrophic populations in SLW partition a majority of their carbon demand to cellular maintenance rather than growth. Chemoautotrophic CO2-fixation exceeded heterotrophic organic C-demand by a factor of ~1.5. Aerobic respiratory activity associated with heterotrophic and chemoautotrophic metabolism surpassed the estimated supply of oxygen to SLW, implying that microbial activity could deplete the oxygenated waters, resulting in anoxia. We used thermodynamic calculations to examine the biogeochemical and energetic consequences of environmentally imposed switching between aerobic and anaerobic metabolisms

  6. Physiological Ecology of Microorganisms in Subglacial Lake Whillans

    Science.gov (United States)

    Vick-Majors, Trista J.; Mitchell, Andrew C.; Achberger, Amanda M.; Christner, Brent C.; Dore, John E.; Michaud, Alexander B.; Mikucki, Jill A.; Purcell, Alicia M.; Skidmore, Mark L.; Priscu, John C.

    2016-01-01

    Subglacial microbial habitats are widespread in glaciated regions of our planet. Some of these environments have been isolated from the atmosphere and from sunlight for many thousands of years. Consequently, ecosystem processes must rely on energy gained from the oxidation of inorganic substrates or detrital organic matter. Subglacial Lake Whillans (SLW) is one of more than 400 subglacial lakes known to exist under the Antarctic ice sheet; however, little is known about microbial physiology and energetics in these systems. When it was sampled through its 800 m thick ice cover in 2013, the SLW water column was shallow (~2 m deep), oxygenated, and possessed sufficient concentrations of C, N, and P substrates to support microbial growth. Here, we use a combination of physiological assays and models to assess the energetics of microbial life in SLW. In general, SLW microorganisms grew slowly in this energy-limited environment. Heterotrophic cellular carbon turnover times, calculated from 3H-thymidine and 3H-leucine incorporation rates, were long (60 to 500 days) while cellular doubling times averaged 196 days. Inferred growth rates (average ~0.006 d−1) obtained from the same incubations were at least an order of magnitude lower than those measured in Antarctic surface lakes and oligotrophic areas of the ocean. Low growth efficiency (8%) indicated that heterotrophic populations in SLW partition a majority of their carbon demand to cellular maintenance rather than growth. Chemoautotrophic CO2-fixation exceeded heterotrophic organic C-demand by a factor of ~1.5. Aerobic respiratory activity associated with heterotrophic and chemoautotrophic metabolism surpassed the estimated supply of oxygen to SLW, implying that microbial activity could deplete the oxygenated waters, resulting in anoxia. We used thermodynamic calculations to examine the biogeochemical and energetic consequences of environmentally imposed switching between aerobic and anaerobic metabolisms in the SLW

  7. Subglacial Calcites from Northern Victoria Land: archive of Antarctic volcanism in the Last Glacial Maximum

    Science.gov (United States)

    Frisia, Silvia; Weirich, Laura; Hellstrom, John; Borsato, Andrea; Golledge, Nicholas R.; Anesio, Alexandre M.; Bajo, Petra; Drysdale, Russell N.; Augustinus, Paul C.; Barbante, Carlo; Cooper, Alan

    2017-04-01

    Subglacial carbonates bear similarities to stalagmites in their fabrics and the potential to obtain precise chronologies using U-series methods. Their chemical properties also reflect those of their parent waters, which, in contrast to stalagmites, are those of subglacial meltwaters. In analogy to speleothems, stable Carbon isotope ratios and trace elements such as Uranium, Iron and Manganese provide the opportunity to investigate ancient extreme environments without the need to drill through thousands of metres of ice. Sedimentological, geochemical and microbial evidence preserved in LGM subglacial calcites from Northern Victoria Land, close to the East Antarctic Ice Sheet margin, allow us to infer that subglacial volcanism was active in the Trans Antarctic Mountain region and induced basal ice melting. We hypothesize that a meltwater reservoir was drained and injected into interconnected basal pore systems where microbial processes enhanced bedrock weathering and, thus, released micronutrients. Volcanic influence is supported by the presence of fluorine (F) and sulphur in sediment-laden calcite layers containing termophilic species. Notably, calcite δ13C points to dissolved inorganic carbon evolved from subglacial metabolic processes. Once transported to the sea, soluble iron likely contributed to fertilizing the Southern Ocean and CO2 drawdown. This is the first well-dated evidence for LGM volcanism in Antarctica, which complements the record of volcanic eruptions retrieved from Talos Dome ice core, and supports the hypothesis of large-scale volcanism as an important driver of climate change. We conclude that subglacial carbonates are equivalent to speleothems in their palaeoclimate potential and may become a most useful source of information of ecosystems and processes at peak glacials in high altitude/high latitude settings.

  8. Advances in modelling subglacial lakes and their interaction with the Antarctic ice sheet.

    Science.gov (United States)

    Pattyn, Frank; Carter, Sasha P; Thoma, Malte

    2016-01-28

    Subglacial lakes have long been considered hydraulically isolated water bodies underneath ice sheets. This view changed radically with the advent of repeat-pass satellite altimetry and the discovery of multiple lake discharges and water infill, associated with water transfer over distances of more than 200 km. The presence of subglacial lakes also influences ice dynamics, leading to glacier acceleration. Furthermore, subglacial melting under the Antarctic ice sheet is more widespread than previously thought, and subglacial melt rates may explain the availability for water storage in subglacial lakes and water transport. Modelling of subglacial water discharge in subglacial lakes essentially follows hydraulics of subglacial channels on a hard bed, where ice sheet surface slope is a major control on triggering subglacial lake discharge. Recent evidence also points to the development of channels in deformable sediment in West Antarctica, with significant water exchanges between till and ice. Most active lakes drain over short time scales and respond rapidly to upstream variations. Several Antarctic subglacial lakes exhibit complex interactions with the ice sheet due to water circulation. Subglacial lakes can therefore-from a modelling point of view-be seen as confined small oceans underneath an imbedded ice shelf. © 2015 The Author(s).

  9. Geoethical Approach to Antarctic Subglacial Lakes Exploration

    Science.gov (United States)

    Talalay, Pavel; Markov, Alexey; Sysoev, Mikhail

    2014-05-01

    Antarctic subglacial aquatic environment have become of great interest to the science community because they may provide unique information about microbial evolution, the past climate of the Earth, and the formation of the Antarctic ice sheet. Nowadays it is generally recognized that a vast network of lakes, rivers, and streams exists thousands of meters beneath Antarctic Ice Sheets. Up to date only four boreholes accessed subglacial aquatic system but three of them were filled with high-toxic drilling fluid, and the subglacial water was contaminated. Two recent exploration programs proposed by UK and USA science communities anticipated direct access down to the lakes Ellsworth and Whillans, respectively, in the 2012/2013 Antarctic season. A team of British scientists and engineers engaged in the first attempt to drill into Lake Ellsworth but failed. US research team has successfully drilled through 800 m of Antarctic ice to reach a subglacial lake Whillans and retrieve water and sediment samples. Both activities used hot-water drilling technology to access lakes. Hot water is considered by the world science community as the most clean drilling fluid medium from the present point of view but it cannot solve environmental problems in total because hot-water even when heated to 90 °C, filtered to 0.2 μm, and UV treated at the surface could pick up microorganisms from near-surface snow and circulate them in great volume through the borehole. Another negative impact of hot-water circulation medium is thermal pollution of subglacial water. The new approach to Antarctic subglacial lakes exploration is presented by sampling technology with recoverable autonomous sonde which is equipped by two hot-points with heating elements located on the bottom and top sides of the sonde. All down-hole sonde components will be sterilized by combination of chemical wash, HPV and UV sterilization prior using. At the beginning of the summer season sonde is installed on the surface of the

  10. Modeling Subglacial Permafrost Evolution

    Science.gov (United States)

    Koutnik, M. R.; Marshall, S.

    2002-12-01

    Permanently frozen ground was present both beneath and peripheral to the Quaternary ice sheets. In areas where the ice sheet grew or advanced over permafrost, the ice sheet insulated the ground, leading to subglacial permafrost degradation. This has created distinct signatures of ice sheet occupation in the Canadian north and in Alaska during the last glacial period, with greatly diminished permafrost thickness in regions that were ice covered for an extended period. In contrast, areas peripheral to the ice sheet, including the Midwest United States, were cooled by the glacial climate conditions and the regional cooling influence of the ice sheet, leading to permafrost growth. We have developed a sub- and proglacial diffusion based permafrost model that utilizes a logarithmic grid transformation to more efficiently track the changing depth of permafrost with time. This model is coupled with the ice sheet thermodynamic model of Marshall and Clarke [1997a] to explore the geologic signatures of the last glacial cycle in North America. This offers the potential for new constraints on modeled ice sheet history. Preliminary model runs show that the overlying ice sheet has a significant effect on the underlying and peripheral permafrost degradation and formation. Subglacial permafrost is also important because its evolution influences the basal temperature of the ice sheet, critical for evolution of subglacial hydrology and fast flow instabilities (e.g. ice streams). We present results of permafrost conditions under the last glacial maximum ice sheet and the effect of permafrost on basal temperature evolution through the last glacial cycle in North America. Marshall, S. J. and G. K. C. Clarke, 1997a. J. Geophys. Res., 102 (B9), 20,599-20,614.

  11. Combination of SAR remote sensing and GIS for monitoring subglacial volcanic activity – recent results from Vatnajökull ice cap (Iceland

    Directory of Open Access Journals (Sweden)

    U. Münzer

    2007-11-01

    Full Text Available This paper presents latest results from the combined use of SAR (Synthetic Aperture Radar remote sensing and GIS providing detailed insights into recent volcanic activity under Vatnajökull ice cap (Iceland. Glaciers atop active volcanoes pose a constant potential danger to adjacent inhabited regions and infrastructure. Besides the usual volcanic hazards (lava flows, pyroclastic clouds, tephra falls, etc., the volcano-ice interaction leads to enormous meltwater torrents (icelandic: jökulhlaup, devastating large areas in the surroundings of the affected glacier. The presented monitoring strategy addresses the three crucial questions: When will an eruption occur, where is the eruption site and which area is endangered by the accompanying jökulhlaup. Therefore, sufficient early-warning and hazard zonation for future subglacial volcanic eruptions becomes possible, as demonstrated for the Bardárbunga volcano under the northern parts of Vatnajökull. Seismic activity revealed unrest at the northern flanks of Bardárbunga caldera at the end of September 2006. The exact location of the corresponding active vent and therefore a potentially eruptive area could be detected by continuous ENVISAT-ASAR monitoring. With this knowledge a precise prediction of peri-glacial regions prone to a devastating outburst flood accompanying a possible future eruption is possible.

  12. Physiography and tectonic setting of the subglacial lake district between Vostok and Belgica subglacial highlands (Antarctica)

    Science.gov (United States)

    Tabacco, I. E.; Cianfarra, P.; Forieri, A.; Salvini, F.; Zirizotti, A.

    2006-06-01

    We present the interpretation of 11 radio echo-sounding (RES) missions carried out over the Vostok-Dome Concordia region during the Italian Antarctic expeditions in the period 1995-2001. The extension and the density of the radar data in the surveyed area allowed to reconstruct a reliable subglacial morphology and to identify four relevant morphological structures namely: the Aurora trench, the Concordia trench, the Concordia ridge and the South Hills. These structures show evidence compatible with the presence of tectonic features. Morphological considerations indicate their development in Cenozoic time. Hybrid cellular automata (HCA)-based numerical modelling allowed to justify a possible role played by the tectonics of the Aurora and Concordia trench evolution. This was accomplished by matching the bed profiles along opportunely projected sections with the modelled surfaces as derived by the activity of normal faults with variable surfaces within the continental crust. The Vostok-Dome C region is characterized by a large number of subglacial lakes. From the analysis of basal reflected power echo, we identified 14 new lakes and obtained information about their physiography as well as their possible relations with tectonics. We propose a grouping of subglacial lakes on the base of their physiography and geological setting, namely relief lakes, basin lakes and trench lakes. Relief lakes located in the Belgica subglacial highlands and are characterized by sharp and steep symmetric edges, suggesting a maximum water depth of the order of 100 m. Their origin may well relate to localized, positive geothermal flux anomalies. Basin lakes located in the Vincennes subglacial basin and are characterized by wider dimension that allow the development of well-defined, flat ice surface anomalies. Trench lakes characterize the Aurora and Concordia trenches as the possible effect of normal fault activity.

  13. Aerobic and Anaerobic Thiosulfate Oxidation by a Cold-Adapted, Subglacial Chemoautotroph

    Science.gov (United States)

    Harrold, Zoë R.; Skidmore, Mark L.; Hamilton, Trinity L.; Desch, Libby; Amada, Kirina; van Gelder, Will; Glover, Kevin; Roden, Eric E.

    2015-01-01

    Geochemical data indicate that protons released during pyrite (FeS2) oxidation are important drivers of mineral weathering in oxic and anoxic zones of many aquatic environments, including those beneath glaciers. Oxidation of FeS2 under oxic, circumneutral conditions proceeds through the metastable intermediate thiosulfate (S2O32−), which represents an electron donor capable of supporting microbial metabolism. Subglacial meltwaters sampled from Robertson Glacier (RG), Canada, over a seasonal melt cycle revealed concentrations of S2O32− that were typically below the limit of detection, despite the presence of available pyrite and concentrations of the FeS2 oxidation product sulfate (SO42−) several orders of magnitude higher than those of S2O32−. Here we report on the physiological and genomic characterization of the chemolithoautotrophic facultative anaerobe Thiobacillus sp. strain RG5 isolated from the subglacial environment at RG. The RG5 genome encodes genes involved with pathways for the complete oxidation of S2O32−, CO2 fixation, and aerobic and anaerobic respiration with nitrite or nitrate. Growth experiments indicated that the energy required to synthesize a cell under oxygen- or nitrate-reducing conditions with S2O32− as the electron donor was lower at 5.1°C than 14.4°C, indicating that this organism is cold adapted. RG sediment-associated transcripts of soxB, which encodes a component of the S2O32−-oxidizing complex, were closely affiliated with soxB from RG5. Collectively, these results suggest an active sulfur cycle in the subglacial environment at RG mediated in part by populations closely affiliated with RG5. The consumption of S2O32− by RG5-like populations may accelerate abiotic FeS2 oxidation, thereby enhancing mineral weathering in the subglacial environment. PMID:26712544

  14. Investigating the hydrological origins of Blood Falls - geomicrobiological insights into a briny subglacial Antarctic aquifer

    Science.gov (United States)

    Mikucki, J.; Tulaczyk, S. M.; Purcell, A. M.; Dachwald, B.; Lyons, W. B.; Welch, K. A.; Auken, E.; Dugan, H. A.; Walter, J. I.; Pettit, E. C.; Doran, P. T.; Virginia, R. A.; Schamper, C.; Foley, N.; Feldmann, M.; Espe, C.; Ghosh, D.; Francke, G.

    2015-12-01

    Subglacial waters tend to accumulate solutes from extensive rock-water interactions, which, when released to the surface, can provide nutrients to surface ecosystems providing a 'hot spot' for microbial communities. Blood Falls, an iron-rich, saline feature at the terminus of Taylor Glacier in the McMurdo Dry Valleys, Antarctica is a well-studied subglacial discharge. Here we present an overview of geophysical surveys, thermomechanical drilling exploration and geomicrobiological analyses of the Blood Falls system. A helicopter-borne transient electromagnetic system (SkyTEM) flown over the Taylor Glacier revealed a surprisingly extensive subglacial aquifer and indicates that Blood Falls may be the only surface manifestation of this extensive briny groundwater. Ground-based temperature sensing and GPR data combined with the helicopter-borne TEM data enabled targeted drilling into the englacial conduit that delivers brine to the surface. During the 2014-15 austral summer field season, we used a novel ice-melting drill (the IceMole) to collect englacial brine for geomicrobiological analyses. Results from previously collected outflow and more recent samples indicate that the brine harbors a metabolically active microbial community that persists, despite cold, dark isolation. Isotope geochemistry and molecular analysis of functional genes from BF suggested that a catalytic or 'cryptic' sulfur cycle was linked to iron reduction. Recent metagenomic analysis confirms the presence of numerous genes involved in oxidative and reductive sulfur transformations. Metagenomic and metabolic activity data also indicate that subglacial dark CO2 fixation occurs via various pathways. Genes encoding key steps in CO2 fixation pathways including the Calvin Benson Basham and Wood Ljungdahl pathway were present and brine samples showed measureable uptake of 14C-labeled bicarbonate. These results support the notion that, like the deep subsurface, subglacial environments are chemosynthetic

  15. Possible Effects on the Stability of the West Antarctic Ice Sheet (WAIS) and Associated Sea-level Rise From Active-Recent Subglacial Volcanism Interpreted from Aeromagnetic and Radar Ice-sounding Observations

    Science.gov (United States)

    Behrendt, J. C.

    2009-12-01

    Aeromagnetic profiles (>10,000 km) acquired in the early 1960s over the West Antarctic Ice Sheet (WAIS) combined with coincident aeromagnetic and radar ice sounding in 1978-79 indicated numerous high-amplitude, shallow-source, magnetic anomalies over a very extensive area of the volcanically active West Antarctic rift system interpreted as caused by subglacial volcanic rocks. These early aerogeophysical surveys defined this area as >500,000 km2. Five-kilometer spaced coincident aeromagnetic and radar ice sounding surveys since 1990 provide three dimensional characterization of the magnetic field and bed topography beneath the ice sheet. These 5-50-km width, semicircular magnetic anomalies range from 100->1000 nT as observed ~1 km over the 2-3 km thick ice. Behrendt et al, (2005, 2008) interpreted these anomalies as indicating >1000 "volcanic centers". requiring high remanent normal (and at least 10% reversed) magnetizations in the present field direction. These data have shown that >80% of the anomaly sources at the bed of the WAIS, have been modified by the moving ice into which they were injected, requiring a younger age than the WAIS (about 25 Ma). Behrendt et al., (1994; 2007) conservatively estimated >1 x 106 km3 volume of volcanic sources to account for the area of the "volcanic center" anomalies. Although exposed volcanoes surrounding the WAIS extend in age to ~34 m.y., Mt Erebus, (Melbourne, (1000 volcanic, magnetic-anomaly sources are active today, or in the recent past, in the drainage area of the WAIS, subglacial volcanism may still have a significant effect on the dynamics of the WAIS. Interpreted active subglacial volcanism is revealed by aerogeophysical data reported by Blankenship et al., (1993, Mt. Casertz), and Corr and Vaughan, (2008, near Hudson Mts.), who raised the question of possible volcanic effects on the regime of the WAIS. Wingham et al. (2009) reported an average rate of volume loss from 2.6 to 10.1 km3/yr from 1995 to 2006 for the Pine

  16. Subglacial till formation: Microscale processes within the subglacial shear zone

    Science.gov (United States)

    Hart, Jane K.

    2017-08-01

    This was a study of subglacial deformation till genesis from a modern temperate glacier, at Skálafellsjökull, Iceland. Detailed microscale properties of till samples (from Scanning Electron Microscope [SEM] and thin section analysis) were examined from a glacial site with in situ subglacial process monitoring and an exposed subglacial surface in the foreland. Two lithofacies were examined, a grey sandy till derived from the ash and basalt, and a silty reddish brown till derived from oxidized paleosols and/or tephra layers. These also represented a clay-content continuum from low (0.3%) to high (22.3%). The evolution from debris to subglacial till was investigated. This included a reduction in grain-size (21% for grey lithology, 13% reddish brown lithology), and reduction in rounding (RA) (32% for the grey lithology, 26% for the reddish brown lithology), and the quantification and analysis of the different grain erosion/comminution processes in the resultant till. It was shown that the microstructures within a till were dependent on shear strain and glaciological conditions (deformation history). The low clay content tills were dominated by linear structures (lineations and boudins, and anisotropic microfabric) whilst the higher clay content tills were dominated by rotational structures (turbates and plaster, and isotropic microfabric). These results are important in our understanding of the formation of both modern and Quaternary tills and informs our reconstruction of past glacial dynamics.

  17. Exploration of Subglacial Lake Ellsworth

    Science.gov (United States)

    Ross, N.

    2012-12-01

    Antarctic subglacial lakes are thought to be extreme habitats for microbial life and may contain important records of ice sheet history within their lake-floor sediments. To find if this is true, and to answer the science questions that would follow, direct measurement and sampling of these environments is required. Ever since the water depth of Vostok Subglacial Lake in East Antarctica was shown to be >500 m, attention has been given to how these unique, ancient and pristine subglacial environments may be entered without contamination and adverse disturbance. Several organizations have offered guidelines on the desirable cleanliness and sterility requirements for direct sampling experiments, including the US National Academy of Sciences and the Scientific Committee on Antarctic Research. The aims, design and implementation of subglacial lake access experiments have direct relevance for the exploration of extra-terrestrial ice-covered bodies (e.g. Europa) and the search for microbial life elsewhere in the Solar System. This presentation summarizes the scientific protocols and methods being developed for the exploration of Ellsworth Subglacial Lake in West Antarctica, and provides an up-to-date summary of the status of the project. The proposed exploration, planned for December 2012, involves accessing the lake using a hot-water drill and deploying a sampling probe and sediment corer to allow in situ measurement and sample collection. Details are presented on how this can be undertaken with minimal environmental impact that maximizes scientific return without compromising the environment for future experiments. The implications of this experiment for the search for extra-terrestrial life will be discussed.

  18. Lake Vostok: From a Continental Margin to a Subglacial Lake

    Science.gov (United States)

    Studinger, M.; Bell, R. E.; KArner, G. D.; Tikku, A. A.; Levin, V.; Raymond, C. A.; Lerner-Lam, A.

    2002-05-01

    Subglacial ecosystems, in particular subglacial lakes, represent the most oligothrophic environments on Earth. The geologic origin of Lake Vostok is a critical boundary condition for both the stability of the lake and energy fluxes into the lake. Microbial life may use geothermal energy, similar to life discovered at deep sea hydrothermal vents. Significant geothermal anomalies are often associated with active faulting. The topographic depression which forms the craddle for Lake Vostok is part of a regional tectonic structure ranging from the Gamburtsev Subglacial Mountains to the Aurora Subglacial Basin. This geologic boundary was formed by emplacement of a thrust sheet from the east over a pre-existing passive continental margin beneath the present-day Lake Vostok. No data exist to directly date either the timing of passive margin formation or the subsequent crustal shortening. Minor extensional reactivation of the thrust sheet explains a simple mechanism to explain the formation of the Lake Vostok basin. The steep slopes bounding this depression are likley being fault-controlled. Our recent discovery of microseismic activity suggest that this faults might be active and could act as conduits for convecting fluids. The tectonic processes can have an important influence on the ecosystem within the lake.

  19. Landscape evolution by subglacial quarrying

    DEFF Research Database (Denmark)

    Ugelvig, Sofie Vej; Egholm, D.L.; Iverson, Neal R.

    of sliding and erosion is not well supported when considering models for quarrying of rock blocks from the bed. Iverson (2012) introduced a new subglacial quarrying model that operates from the theory of adhesive wear. The model is based on the fact that cavities, with a high level of bedrock differential...... to a model for glacial hydrology. In order to also include the effects of cavitation on the subglacial sliding rate, we use a sliding law proposed by Schoof (2005), which includes an upper limit for the stress that can be supported at the bed. Computational experiments show that the combined influence...... evolution models. Geology, v. 40, no. 8, 679-682 (2012). Schoof, C. The effect of cavitation on glacier sliding. Proc. R. Soc. A , 461, 609-627 (2005). Jaeger, J.C., and Cook, N.G.W. Fundamentals of rock mechanics: New York, Chapman and Hall, 593 p. (1979)...

  20. Culturable bacteria in subglacial sediments and ice from two Southern Hemisphere glaciers.

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    Foght, J; Aislabie, J; Turner, S; Brown, C E; Ryburn, J; Saul, D J; Lawson, W

    2004-05-01

    Viable prokaryotes have been detected in basal sediments beneath the few Northern Hemisphere glaciers that have been sampled for microbial communities. However, parallel studies have not previously been conducted in the Southern Hemisphere, and subglacial environments in general are a new and underexplored niche for microbes. Unfrozen subglacial sediments and overlying glacier ice samples collected aseptically from the Fox Glacier and Franz Josef Glacier in the Southern Alps of New Zealand now have been shown to harbor viable microbial populations. Total direct counts of 2-7 x 10(6) cells g(-1) dry weight sediment were observed, whereas culturable aerobic heterotrophs ranged from 6-9 x 10(5) colony-forming units g(-1) dry weight. Viable counts in the glacier ice typically were 3-4 orders of magnitude smaller than in sediment. Nitrate-reducing and ferric iron-reducing bacteria were detected in sediment samples from both glaciers, but were few or below detection limits in the ice samples. Nitrogen-fixing bacteria were detected only in the Fox Glacier sediment. Restriction fragment analysis of 16S rDNA amplified from 37 pure cultures of aerobic heterotrophs capable of growth at 4 degrees C yielded 23 distinct groups, of which 11 were identified as beta-Proteobacteria. 16S rDNA sequences from representatives of these 11 groups were analyzed phylogenetically and shown to cluster with bacteria such as Polaromonas vacuolata and Rhodoferax antarcticus, or with clones obtained from permanently cold environments. Chemical analysis of sediment and ice samples revealed a dilute environment for microbial life. Nevertheless, both the sediment samples and one ice sample demonstrated substantial aerobic mineralization of 14C-acetate at 8 degrees C, indicating that sufficient nutrients and viable psychrotolerant microbes were present to support metabolism. Unfrozen subglacial sediments may represent a significant global reservoir of biological activity with the potential to

  1. Subglacial lake and meltwater flow predictions of the last North American and European Ice Sheets

    Science.gov (United States)

    Livingstone, S. J.; Clark, C. D.; Tarasov, L.

    2012-04-01

    There is increasing recognition that subglacial lakes act as key components within the ice sheet system, capable of influencing ice-sheet topography, ice volume and ice flow. The subglacial water systems themselves are recognised as being both active and dynamic, with large discharges of meltwater capable of flowing down hydrological pathways both between lakes and to the ice-sheet margins. At present, much glaciological research is concerned with the role of modern subglacial lake systems in Antarctica. Another approach to the exploration of subglacial lakes involves identification of the geological record of subglacial lakes that once existed beneath ice sheets of the last glaciation. Investigation of such palaeo-subglacial lakes offers significant advantages because we have comprehensive information about the bed properties, they are much more accessible and we can examine and sample the sediments with ease. If we can find palaeo-subglacial lakes then we have the potential to advance understanding with regard to the topographic context and hydrological pathways that the phenomena form a part of; essentially we gain spatial and sedimentological information in relation to investigations of contemporary subglacial lakes and lose out on the short-time dynamics. In this work we present predictions of palaeo-subglacial lakes and meltwater drainage pathways under the former European and North American ice sheets during the last glaciation. We utilise data on the current topography and seafloor bathymetry, and elevation models of the ice and ground surface topography (interpolated to a 5 km grid) to calculate the hydraulic potential surface at the ice-sheet bed. Meltwater routing algorithms and the flooding of local hydraulic minima allow us to predict subglacial channels and lakes respectively. Given that specific ice-surface and bed topographies are only known from modelled outputs, and thus contain significant uncertainty, we utilise many such outputs to examine

  2. Unveiling the Antarctic subglacial landscape.

    Science.gov (United States)

    Warner, Roland; Roberts, Jason

    2010-05-01

    Better knowledge of the subglacial landscape of Antarctica is vital to reducing uncertainties regarding prediction of the evolution of the ice sheet. These uncertainties are associated with bedrock geometry for ice sheet dynamics, including possible marine ice sheet instabilities and subglacial hydrological pathways (e.g. Wright et al., 2008). Major collaborative aerogeophysics surveys motivated by the International Polar Year (e.g. ICECAP and AGAP), and continuing large scale radar echo sounding campaigns (ICECAP and NASA Ice Bridge) are significantly improving the coverage. However, the vast size of Antarctica and logistic difficulties mean that data gaps persist, and ice thickness data remains spatially inhomogeneous. The physics governing large scale ice sheet flow enables ice thickness, and hence bedrock topography, to be inferred from knowledge of ice sheet surface topography and considerations of ice sheet mass balance, even in areas with sparse ice thickness measurements (Warner and Budd, 2000). We have developed a robust physically motivated interpolation scheme, based on these methods, and used it to generate a comprehensive map of Antarctic bedrock topography, using along-track ice thickness data assembled for the BEDMAP project (Lythe et al., 2001). This approach reduces ice thickness biases, compared to traditional inverse distance interpolation schemes which ignore the information available from considerations of ice sheet flow. In addition, the use of improved balance fluxes, calculated using a Lagrangian scheme, eliminates the grid orientation biases in ice fluxes associated with finite difference methods (Budd and Warner, 1996, Le Brocq et al., 2006). The present map was generated using a recent surface DEM (Bamber et al., 2009, Griggs and Bamber, 2009) and accumulation distribution (van de Berg et al., 2006). Comparing our results with recent high resolution regional surveys gives confidence that all major subglacial topographic features are

  3. Antarctic Subglacial Lake Classification Inventory, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set is an Antarctic radar-based subglacial lake classification collection, which focuses on the radar reflection properties of each given lake.

  4. Sedentary activity associated with metabolic syndrome independent of physical activity

    DEFF Research Database (Denmark)

    Bankoski, Andrea; Harris, Tamara B; McClain, James J

    2011-01-01

    This study examined the association between objectively measured sedentary activity and metabolic syndrome among older adults.......This study examined the association between objectively measured sedentary activity and metabolic syndrome among older adults....

  5. Viscosity dictates metabolic activity of Vibrio ruber

    Science.gov (United States)

    Borić, Maja; Danevčič, Tjaša; Stopar, David

    2012-01-01

    Little is known about metabolic activity of bacteria, when viscosity of their environment changes. In this work, bacterial metabolic activity in media with viscosity ranging from 0.8 to 29.4 mPas was studied. Viscosities up to 2.4 mPas did not affect metabolic activity of Vibrio ruber. On the other hand, at 29.4 mPas respiration rate and total dehydrogenase activity increased 8 and 4-fold, respectively. The activity of glucose-6-phosphate dehydrogenase (GPD) increased up to 13-fold at higher viscosities. However, intensified metabolic activity did not result in faster growth rate. Increased viscosity delayed the onset as well as the duration of biosynthesis of prodigiosin. As an adaptation to viscous environment V. ruber increased metabolic flux through the pentose phosphate pathway and reduced synthesis of a secondary metabolite. In addition, V. ruber was able to modify the viscosity of its environment. PMID:22826705

  6. Exploring Explanations of Subglacial Bedform Sizes Using Statistical Models.

    Directory of Open Access Journals (Sweden)

    John K Hillier

    Full Text Available Sediments beneath modern ice sheets exert a key control on their flow, but are largely inaccessible except through geophysics or boreholes. In contrast, palaeo-ice sheet beds are accessible, and typically characterised by numerous bedforms. However, the interaction between bedforms and ice flow is poorly constrained and it is not clear how bedform sizes might reflect ice flow conditions. To better understand this link we present a first exploration of a variety of statistical models to explain the size distribution of some common subglacial bedforms (i.e., drumlins, ribbed moraine, MSGL. By considering a range of models, constructed to reflect key aspects of the physical processes, it is possible to infer that the size distributions are most effectively explained when the dynamics of ice-water-sediment interaction associated with bedform growth is fundamentally random. A 'stochastic instability' (SI model, which integrates random bedform growth and shrinking through time with exponential growth, is preferred and is consistent with other observations of palaeo-bedforms and geophysical surveys of active ice sheets. Furthermore, we give a proof-of-concept demonstration that our statistical approach can bridge the gap between geomorphological observations and physical models, directly linking measurable size-frequency parameters to properties of ice sheet flow (e.g., ice velocity. Moreover, statistically developing existing models as proposed allows quantitative predictions to be made about sizes, making the models testable; a first illustration of this is given for a hypothesised repeat geophysical survey of bedforms under active ice. Thus, we further demonstrate the potential of size-frequency distributions of subglacial bedforms to assist the elucidation of subglacial processes and better constrain ice sheet models.

  7. Viable cold-tolerant iron-reducing microorganisms in geographically diverse subglacial environments

    Science.gov (United States)

    Nixon, Sophie L.; Telling, Jon P.; Wadham, Jemma L.; Cockell, Charles S.

    2017-03-01

    Subglacial environments are known to harbour metabolically diverse microbial communities. These microbial communities drive chemical weathering of underlying bedrock and influence the geochemistry of glacial meltwater. Despite its importance in weathering reactions, the microbial cycling of iron in subglacial environments, in particular the role of microbial iron reduction, is poorly understood. In this study we address the prevalence of viable iron-reducing microorganisms in subglacial sediments from five geographically isolated glaciers. Iron-reducing enrichment cultures were established with sediment from beneath Engabreen (Norway), Finsterwalderbreen (Svalbard), Leverett and Russell glaciers (Greenland), and Lower Wright Glacier (Antarctica). Rates of iron reduction were higher at 4 °C compared with 15 °C in all but one duplicated second-generation enrichment culture, indicative of cold-tolerant and perhaps cold-adapted iron reducers. Analysis of bacterial 16S rRNA genes indicates Desulfosporosinus were the dominant iron-reducing microorganisms in low-temperature Engabreen, Finsterwalderbreen and Lower Wright Glacier enrichments, and Geobacter dominated in Russell and Leverett enrichments. Results from this study suggest microbial iron reduction is widespread in subglacial environments and may have important implications for global biogeochemical iron cycling and export to marine ecosystems.

  8. Industry as a metabolic activity.

    OpenAIRE

    Smart, B.

    1992-01-01

    The concept of "industrial economic metabolism" can provide a bridge to better understanding between environmentalists and industry. In nature each individual or species reacts to natural stimuli, competing with others for resources, extending its domain until it loses comparative advantage and comes to equilibrium with an adjacent competitor. Those species that succeed over time flourish; those that do not, diminish or disappear. Nature's rule book has no moral or ethical ingredient beyond s...

  9. Industry as a metabolic activity.

    Science.gov (United States)

    Smart, B

    1992-02-01

    The concept of "industrial economic metabolism" can provide a bridge to better understanding between environmentalists and industry. In nature each individual or species reacts to natural stimuli, competing with others for resources, extending its domain until it loses comparative advantage and comes to equilibrium with an adjacent competitor. Those species that succeed over time flourish; those that do not, diminish or disappear. Nature's rule book has no moral or ethical ingredient beyond self-interest. Corporate metabolisms are remarkably similar to those of nature. They too react to stimuli, collect and use resources, and grow or perish based on how effectively they compete. Corporate management recognizes and responds naturally and efficiently to cost and price signals. Through them it selects resources and converts them into useful products. The efficiency with which this is done is measured by profit, the lifeblood of the corporation and its means of growth. Profit thus provides a discipline on corporate behavior, encouraging efficient performers, and, by its absence, weeding out others. Unfettered by influences other than economics, the path to corporate success is unlikely to be a compassionate one. The dilemma of the manager is that to do what is socially "right" often conflicts with what must be done to survive and prosper. Fortunately, corporations' behavior can be altered by society when their purely economic role comes into conflict with other human values. The environment and the economy are not separate systems but intertwined to form a complex natural and social setting. The human-designed economic system depends on natural resource inputs, and in turn its metabolic wastes can overload the ecological system, threatening the long-term survivability of both. Increasing concern for the environment now gives the farsighted manager new latitude. There are competitive benefits in some pollution prevention. But there are not sufficiently strong forces to

  10. Penicillium mycobiota in Arctic subglacial ice

    DEFF Research Database (Denmark)

    Sonjak, S.; Frisvad, Jens Christian; Gunde-Cimerman, N.

    2006-01-01

    to be inhabited exclusively by heterotrophic bacteria. In this study we report on the very high occurrence (up to 9000 CFU L-1) and diversity of filamentous Penicillium spp. in the sediment-rich subglacial ice of three different polythermal Arctic glaciers (Svalbard, Norway). The dominant species was P. crustosum......, representing on the average half of all isolated strains from all three glaciers. The other most frequently isolated species were P. bialowiezense, P. chrysogenum, P. thomii, P. solitum, P. palitans, P. echinulatum, P. polonicum, P. commune, P. discolor, P. expansum, and new Penicillium species (sp. 1). Twelve...... more Penicillium species were occasionally isolated. The fungi isolated produced consistent profiles of secondary metabolites, not different from the same Penicillium species from other habitats. This is the first report on the presence of large populations of Penicillium spp. in subglacial sediment...

  11. Numerical Modeling of Subglacial Sediment Deformation

    DEFF Research Database (Denmark)

    Damsgaard, Anders

    2015-01-01

    may cause mass loss in the near future to exceed current best estimates. Ice flow in larger ice sheets focuses in fast-moving streams due to mechanical non-linearity of ice. These ice streams often move at velocities several magnitudes larger than surrounding ice and consequentially constitute...... glaciers move by deforming their sedimentary beds. Several modern ice streams, in particular, move as plug flows due to basal sediment deformation. An intense and long-winded discussion about the appropriate description for subglacial sediment mechanics followed this discovery, with good reason...... velocities previously associated with elastic or viscous ice deformation. If a glacier dominated by subglacial creep experiences prolonged events of strong surface melt or increased driving stresses, the plastic strength limit can cause rapid acceleration downslope due to imbalance of stresses....

  12. Rapidly changing subglacial hydrological pathways at a tidewater glacier revealed through simultaneous observations of water pressure, supraglacial lakes, meltwater plumes and surface velocities

    Science.gov (United States)

    How, Penelope; Benn, Douglas I.; Hulton, Nicholas R. J.; Hubbard, Bryn; Luckman, Adrian; Sevestre, Heïdi; van Pelt, Ward J. J.; Lindbäck, Katrin; Kohler, Jack; Boot, Wim

    2017-11-01

    Subglacial hydrological processes at tidewater glaciers remain poorly understood due to the difficulty in obtaining direct measurements and lack of empirical verification for modelling approaches. Here, we investigate the subglacial hydrology of Kronebreen, a fast-flowing tidewater glacier in Svalbard during the 2014 melt season. We combine observations of borehole water pressure, supraglacial lake drainage, surface velocities and plume activity with modelled run-off and water routing to develop a conceptual model that thoroughly encapsulates subglacial drainage at a tidewater glacier. Simultaneous measurements suggest that an early-season episode of subglacial flushing took place during our observation period, and a stable efficient drainage system effectively transported subglacial water through the northern region of the glacier tongue. Drainage pathways through the central and southern regions of the glacier tongue were disrupted throughout the following melt season. Periodic plume activity at the terminus appears to be a signal for modulated subglacial pulsing, i.e. an internally driven storage and release of subglacial meltwater that operates independently of marine influences. This storage is a key control on ice flow in the 2014 melt season. Evidence from this work and previous studies strongly suggests that long-term changes in ice flow at Kronebreen are controlled by the location of efficient/inefficient drainage and the position of regions where water is stored and released.

  13. Rapidly changing subglacial hydrological pathways at a tidewater glacier revealed through simultaneous observations of water pressure, supraglacial lakes, meltwater plumes and surface velocities

    Directory of Open Access Journals (Sweden)

    P. How

    2017-11-01

    Full Text Available Subglacial hydrological processes at tidewater glaciers remain poorly understood due to the difficulty in obtaining direct measurements and lack of empirical verification for modelling approaches. Here, we investigate the subglacial hydrology of Kronebreen, a fast-flowing tidewater glacier in Svalbard during the 2014 melt season. We combine observations of borehole water pressure, supraglacial lake drainage, surface velocities and plume activity with modelled run-off and water routing to develop a conceptual model that thoroughly encapsulates subglacial drainage at a tidewater glacier. Simultaneous measurements suggest that an early-season episode of subglacial flushing took place during our observation period, and a stable efficient drainage system effectively transported subglacial water through the northern region of the glacier tongue. Drainage pathways through the central and southern regions of the glacier tongue were disrupted throughout the following melt season. Periodic plume activity at the terminus appears to be a signal for modulated subglacial pulsing, i.e. an internally driven storage and release of subglacial meltwater that operates independently of marine influences. This storage is a key control on ice flow in the 2014 melt season. Evidence from this work and previous studies strongly suggests that long-term changes in ice flow at Kronebreen are controlled by the location of efficient/inefficient drainage and the position of regions where water is stored and released.

  14. Subglacial lake matters: piracy on a divide between thawed and frozen bed

    Science.gov (United States)

    Carter, S. P.; Bougamont, M. H.; Christoffersen, P.; Fricker, H. A.; Lipscomb, W. H.; Price, S. F.

    2011-12-01

    The two most populated active subglacial lake districts in Antarctica, upper Kamb Ice Stream and lower Whillans Ice Stream, occur along boundaries between where temperature models predict net basal freezing and net basal accretion. This occurs in part due to a basal traction contrast, which creates a ridge in the ice surface and creates a pressure seal; this impedes the downstream movement of water until a subglacial lake flood occurs. Here we use a model for basal water routing, which incorporates subglacial floods and a realistic term for effective pressure, to explore the ability of these floods to provide water to areas of net basal accretion and thus maintain basal lubrication. We hypothesize that these floods can distribute sufficient water to most of the regions experiencing net basal freezing; the exception being those nearest to the lakes themselves, Discharge in these regions likely occurs via narrow subglacial conduits. Over time this will cause ice downstream of the dam to thicken and pre-flood lake levels to increase until water ultimately exits the lake via an alternate route i.e. water piracy. Once piracy occurs, water is no longer supplied along the former flowpath and ice stream shutdown accelerates. We conclude that the formation and quasi-periodic flooding of lakes at the basal melt/ basal freezing boundary is a critical process in accelerating ice stream shutdown.

  15. A balanced water layer concept for subglacial hydrology in large-scale ice sheet models

    Directory of Open Access Journals (Sweden)

    S. Goeller

    2013-07-01

    Full Text Available There is currently no doubt about the existence of a widespread hydrological network under the Antarctic Ice Sheet, which lubricates the ice base and thus leads to increased ice velocities. Consequently, ice models should incorporate basal hydrology to obtain meaningful results for future ice dynamics and their contribution to global sea level rise. Here, we introduce the balanced water layer concept, covering two prominent subglacial hydrological features for ice sheet modeling on a continental scale: the evolution of subglacial lakes and balance water fluxes. We couple it to the thermomechanical ice-flow model RIMBAY and apply it to a synthetic model domain. In our experiments we demonstrate the dynamic generation of subglacial lakes and their impact on the velocity field of the overlaying ice sheet, resulting in a negative ice mass balance. Furthermore, we introduce an elementary parametrization of the water flux–basal sliding coupling and reveal the predominance of the ice loss through the resulting ice streams against the stabilizing influence of less hydrologically active areas. We point out that established balance flux schemes quantify these effects only partially as their ability to store subglacial water is lacking.

  16. A balanced water layer concept for subglacial hydrology in large scale ice sheet models

    Science.gov (United States)

    Goeller, S.; Thoma, M.; Grosfeld, K.; Miller, H.

    2012-12-01

    There is currently no doubt about the existence of a wide-spread hydrological network under the Antarctic ice sheet, which lubricates the ice base and thus leads to increased ice velocities. Consequently, ice models should incorporate basal hydrology to obtain meaningful results for future ice dynamics and their contribution to global sea level rise. Here, we introduce the balanced water layer concept, covering two prominent subglacial hydrological features for ice sheet modeling on a continental scale: the evolution of subglacial lakes and balance water fluxes. We couple it to the thermomechanical ice-flow model RIMBAY and apply it to a synthetic model domain inspired by the Gamburtsev Mountains, Antarctica. In our experiments we demonstrate the dynamic generation of subglacial lakes and their impact on the velocity field of the overlaying ice sheet, resulting in a negative ice mass balance. Furthermore, we introduce an elementary parametrization of the water flux-basal sliding coupling and reveal the predominance of the ice loss through the resulting ice streams against the stabilizing influence of less hydrologically active areas. We point out, that established balance flux schemes quantify these effects only partially as their ability to store subglacial water is lacking.

  17. Metabolic benefits of physical activity

    Directory of Open Access Journals (Sweden)

    Špela Volčanšek

    2014-10-01

    Full Text Available Physical activity is the most beneficial intervention in prevention and treatment of chronic diseases. Life style, which has become mostly sedentary, leads to growing incidence in obesity, what could cause the first so far reduction in life expectancy in developed countries.Physical activity reduces the chronic low-grade inflammation, which plays an important role in the pathogenesis of type 2 diabetes, cardiovascular disease and certain types of cancer. Regular physical activity exerts two anti-inflammatory effects: reduction of visceral fat, which produces the majority of pro-inflammatory cytokines, and production of myokines. It has been proposed that cytokines and other peptides that are produced by muscle fibers should be classified as myokines that exert autocrine, paracrine and endocrine effects. Myokines induce muscle hypertrophy and myogenesis, stimulate fat oxidation, improve insulin sensitivity and have an anti-inflammatory effect.  Therefore, skeletal muscle has been identified as a secretory organ and this provides the basis for understanding how muscles communicate with other organs, such as adipose tissue, liver, pancreas, gut, bones and brain. Physical inactivity leads to an altered myokine profile, associating sedentary life style with some chronic diseases.Physical activity is recommended as a tool for weight management and prevention of weight gain, for weight loss and for prevention of weight regain. High quality studies have confirmed the important impact of exercise on improving blood glucose control in diabetic patients, and on preventing or delaying the onset of type 2 diabetes in predisposed populations. Prescribing specific exercise tailored to individual's needs is an intervention strategy for health improvement. Physical fitness counteracts the detrimental effects of obesity reducing morbidity and mortality.

  18. Subglacial discharge at tidewater glaciers revealed by seismic tremor

    Science.gov (United States)

    Bartholomaus, Timothy C.; Amundson, Jason M.; Walter, Jacob I.; O'Neel, Shad; West, Michael E.; Larsen, Christopher F.

    2015-01-01

    Subglacial discharge influences glacier basal motion and erodes and redeposits sediment. At tidewater glacier termini, discharge drives submarine terminus melting, affects fjord circulation, and is a central component of proglacial marine ecosystems. However, our present inability to track subglacial discharge and its variability significantly hinders our understanding of these processes. Here we report observations of hourly to seasonal variations in 1.5–10 Hz seismic tremor that strongly correlate with subglacial discharge but not with basal motion, weather, or discrete icequakes. Our data demonstrate that vigorous discharge occurs from tidewater glaciers during summer, in spite of fast basal motion that could limit the formation of subglacial conduits, and then abates during winter. Furthermore, tremor observations and a melt model demonstrate that drainage efficiency of tidewater glaciers evolves seasonally. Glaciohydraulic tremor provides a means by which to quantify subglacial discharge variations and offers a promising window into otherwise obscured glacierized environments.

  19. Physical activity in obesity and metabolic syndrome.

    Science.gov (United States)

    Strasser, Barbara

    2013-04-01

    Biological aging is typically associated with a progressive increase in body fat mass and a loss of lean body mass. Owing to the metabolic consequences of reduced muscle mass, it is understood that normal aging and/or decreased physical activity may lead to a higher prevalence of metabolic disorders. Lifestyle modification, specifically changes in diet, physical activity, and exercise, is considered the cornerstone of obesity management. However, for most overweight people it is difficult to lose weight permanently through diet or exercise. Thus, prevention of weight gain is thought to be more effective than weight loss in reducing obesity rates. A key question is whether physical activity can extenuate age-related weight gain and promote metabolic health in adults. Current guidelines suggest that adults should accumulate about 60 minutes of moderate-intensity physical activity daily to prevent unhealthy weight gain. Because evidence suggests that resistance training may promote a negative energy balance and may change body fat distribution, it is possible that an increase in muscle mass after resistance training may be a key mediator leading to better metabolic control. © 2012 New York Academy of Sciences.

  20. AMPK Activation Affects Glutamate Metabolism in Astrocytes

    DEFF Research Database (Denmark)

    Voss, Caroline Marie; Pajęcka, Kamilla; Stridh, Malin H

    2015-01-01

    acid (TCA) cycle was studied using high-performance liquid chromatography analysis supplemented with gas chromatography-mass spectrometry technology. It was found that AMPK activation had profound effects on the pathways involved in glutamate metabolism since the entrance of the glutamate carbon...... affected by a reduction of the flux of glutamate derived carbon through the malic enzyme and pyruvate carboxylase catalyzed reactions. Finally, it was found that in the presence of glutamate as an additional substrate, glucose metabolism monitored by the use of tritiated deoxyglucose was unaffected by AMPK...

  1. PROSPECTS FOR LIFE IN THE SUBGLACIAL LAKE VOSTOK, EAST ANTARCTICA

    Directory of Open Access Journals (Sweden)

    S. A. Bulat

    2012-01-01

    Full Text Available The objective was to estimate the genuine microbial content of ice samples from refrozen water (accretion ice from the subglacialLakeVostok(Antarctica buried beneath the 4-km thick East Antarctic ice sheet as well as surface snow nearby Vostok station. The lake ice samples were extracted by heavy deep ice drilling from3764 mbelow the surface reaching the depth3769.3 mby February 2011 (lake entering. High pressure, an ultra low carbon and chemical content, isolation, complete darkness and the probable excess of oxygen in water for millions of years characterize this extreme environment. A decontamination protocol was first applied to samples selected for the absence of cracks to remove the outer part contaminated by handling and drilling fluid. Preliminary indications showed the accretion ice samples to be almost gas free with the very low impurity content. Flow cytometry showed the very low unevenly distributed biomass in both accretion (0–19 cells per ml and glacier (0–24 cells per ml ice and surface snow (0–0.02 cells per ml as well while repeated microscopic observations were unsuccessful meaning that the whole Central East Antarctic ice sheet seems to be microbial cell-free.We used strategies of Ancient DNA research that include establishing contaminant databases and criteria to validate the amplification results. To date, positive results that passed the artifacts and contaminant databases have been obtained for a few bacterial phylotypes only in accretion ice samples featured by some bedrock sediments. Amongst them are the chemolithoautotrophic thermophile Hydrogenophilus thermoluteolus of beta-Proteobacteria, the actinobacterium rather related (95% to Ilumatobacter luminis and one unclassified phylotype distantly related (92% to soil-inhabiting uncultured bacteria. Combined with geochemical and geophysical considerations, our results suggest the presence of a deep biosphere, possibly thriving within some active faults of the bedrock

  2. Sedentary activity associated with metabolic syndrome independent of physical activity.

    Science.gov (United States)

    Bankoski, Andrea; Harris, Tamara B; McClain, James J; Brychta, Robert J; Caserotti, Paolo; Chen, Kong Y; Berrigan, David; Troiano, Richard P; Koster, Annemarie

    2011-02-01

    This study examined the association between objectively measured sedentary activity and metabolic syndrome among older adults. Data were from 1,367 men and women, aged ≥ 60 years who participated in the 2003-2006 National Health and Nutrition Examination Survey (NHANES). Sedentary time during waking hours was measured by an accelerometer (5 min. A sedentary break was defined as an interruption in sedentary time (≥ 100 counts per minute). Metabolic syndrome was defined according to the Adult Treatment Panel (ATP) III criteria. On average, people spent 9.5 h (65% of wear time) as sedentary. Compared with people without metabolic syndrome, people with metabolic syndrome spent a greater percentage of time as sedentary (67.3 vs. 62.2%), had longer average sedentary bouts (17.7 vs. 16.7 min), had lower intensity during sedentary time (14.8 vs. 15.8 average counts per minute), and had fewer sedentary breaks (82.3 vs. 86.7), adjusted for age and sex (all P metabolic syndrome after adjustment for age, sex, ethnicity, education, alcohol consumption, smoking, BMI, diabetes, heart disease, and physical activity. The association between intensity during sedentary time and metabolic syndrome was borderline significant. The proportion of sedentary time was strongly related to metabolic risk, independent of physical activity. Current results suggest older people may benefit from reducing total sedentary time and avoiding prolonged periods of sedentary time by increasing the number of breaks during sedentary time.

  3. Methylenetetrahydrofolate Reductase Activity and Folate Metabolism

    Directory of Open Access Journals (Sweden)

    Nursen Keser

    2014-04-01

    Full Text Available Folate is a vital B vitamin which is easily water-soluble. It is a natural source which is found in the herbal and animal foods. Folate has important duties in the human metabolism, one of them is the adjustment of the level of plasma homocysteine. Reduction in MTHFR (methylenetetrahydrofolate reductase,which is in charge of the metabolism of homocysteine activity affects the level of homocysteine. Therefore MTHFR is an important enzyme in folate metabolism. Some of the mutations occurring in the MTHFR gene is a risk factor for various diseases and may be caused the hyperhomocysteinemia or the homocystinuria, and they also may lead to metabolic problems. MTHFR is effective in the important pathways such as DNA synthesis, methylation reactions and synthesis of RNA. C677T and A1298C are the most commonly occurring polymorphisms in the gene of MTHFR. The frequency of these polymorphisms show differences in the populations. MTHFR, folate distribution, metabolism of homocysteine and S-adenosylmethionine, by the MTHFR methylation the genetic defects have the potential of affecting the risk of disease in the negative or positive way.

  4. Peroxisome Proliferator Activated Receptors and Lipoprotein Metabolism

    Directory of Open Access Journals (Sweden)

    Sander Kersten

    2008-01-01

    Full Text Available Plasma lipoproteins are responsible for carrying triglycerides and cholesterol in the blood and ensuring their delivery to target organs. Regulation of lipoprotein metabolism takes place at numerous levels including via changes in gene transcription. An important group of transcription factors that mediates the effect of dietary fatty acids and certain drugs on plasma lipoproteins are the peroxisome proliferator activated receptors (PPARs. Three PPAR isotypes can be distinguished, all of which have a major role in regulating lipoprotein metabolism. PPARα is the molecular target for the fibrate class of drugs. Activation of PPARα in mice and humans markedly reduces hepatic triglyceride production and promotes plasma triglyceride clearance, leading to a clinically significant reduction in plasma triglyceride levels. In addition, plasma high-density lipoprotein (HDL-cholesterol levels are increased upon PPARα activation in humans. PPARγ is the molecular target for the thiazolidinedione class of drugs. Activation of PPARγ in mice and human is generally associated with a modest increase in plasma HDL-cholesterol and a decrease in plasma triglycerides. The latter effect is caused by an increase in lipoprotein lipase-dependent plasma triglyceride clearance. Analogous to PPARα, activation of PPARβ/δ leads to increased plasma HDL-cholesterol and decreased plasma triglyceride levels. In this paper, a fresh perspective on the relation between PPARs and lipoprotein metabolism is presented. The emphasis is on the physiological role of PPARs and the mechanisms underlying the effect of synthetic PPAR agonists on plasma lipoprotein levels.

  5. Probe technologies for clean sampling and measurement of subglacial lakes.

    Science.gov (United States)

    Mowlem, Matt; Saw, Kevin; Brown, Robin; Waugh, Edward; Cardwell, Christopher L; Wyatt, James; Magiopoulos, Iordanis; Keen, Peter; Campbell, Jon; Rundle, Nicholas; Gkritzalis-Papadopoulos, Athanasios

    2016-01-28

    It is 4 years since the subglacial lake community published its plans for accessing, sampling, measuring and studying the pristine, and hitherto enigmatic and very different, Antarctic subglacial lakes, Vostok, Whillans and Ellsworth. This paper summarizes the contrasting probe technologies designed for each of these subglacial environments and briefly updates how these designs changed or were used differently when compared to previously published plans. A detailed update on the final engineering design and technical aspects of the probe for Subglacial Lake Ellsworth is presented. This probe is designed for clean access, is negatively buoyant (350 kg), 5.2 m long, 200 mm in diameter, approximately cylindrical and consists of five major units: (i) an upper power and communications unit attached to an optical and electrical conducting tether, (ii)-(iv) three water and particle samplers, and (v) a sensors, imaging and instrumentation pack tipped with a miniature sediment corer. To date, only in Subglacial Lake Whillans have instruments been successfully deployed. Probe technologies for Subglacial Lake Vostok (2014/15) and Lake Ellsworth (2012/13) were not deployed for technical reasons, in the case of Lake Ellsworth because hot-water drilling was unable to access the lake during the field season window. Lessons learned and opportunities for probe technologies in future subglacial access missions are discussed. © 2015 The Author(s).

  6. Microbial Community Structure of Subglacial Lake Whillans, West Antarctica.

    Science.gov (United States)

    Achberger, Amanda M; Christner, Brent C; Michaud, Alexander B; Priscu, John C; Skidmore, Mark L; Vick-Majors, Trista J

    2016-01-01

    Subglacial Lake Whillans (SLW) is located beneath ∼800 m of ice on the Whillans Ice Stream in West Antarctica and was sampled in January of 2013, providing the first opportunity to directly examine water and sediments from an Antarctic subglacial lake. To minimize the introduction of surface contaminants to SLW during its exploration, an access borehole was created using a microbiologically clean hot water drill designed to reduce the number and viability of microorganisms in the drilling water. Analysis of 16S rRNA genes (rDNA) amplified from samples of the drilling and borehole water allowed an evaluation of the efficacy of this approach and enabled a confident assessment of the SLW ecosystem inhabitants. Based on an analysis of 16S rDNA and rRNA (i.e., reverse-transcribed rRNA molecules) data, the SLW community was found to be bacterially dominated and compositionally distinct from the assemblages identified in the drill system. The abundance of bacteria (e.g., Candidatus Nitrotoga, Sideroxydans, Thiobacillus, and Albidiferax) and archaea (Candidatus Nitrosoarchaeum) related to chemolithoautotrophs was consistent with the oxidation of reduced iron, sulfur, and nitrogen compounds having important roles as pathways for primary production in this permanently dark ecosystem. Further, the prevalence of Methylobacter in surficial lake sediments combined with the detection of methanogenic taxa in the deepest sediment horizons analyzed (34-36 cm) supported the hypothesis that methane cycling occurs beneath the West Antarctic Ice Sheet. Large ratios of rRNA to rDNA were observed for several operational taxonomic units abundant in the water column and sediments (e.g., Albidiferax, Methylobacter, Candidatus Nitrotoga, Sideroxydans, and Smithella), suggesting a potentially active role for these taxa in the SLW ecosystem. Our findings are consistent with chemosynthetic microorganisms serving as the ecological foundation in this dark subsurface environment, providing new

  7. Metabolic activities and probiotic potential of bifidobacteria.

    Science.gov (United States)

    Russell, D A; Ross, R P; Fitzgerald, G F; Stanton, C

    2011-09-01

    It has been shown that the gut microbiota regulates fat storage in the body and that disturbances in its composition can lead to the development of certain metabolic disease states. Bifidobacteria are found among the resident microbiota in the gastrointestinal tract (GIT) and their metabolic activities have been shown to beneficially influence the human host. It has been reported that they inhibit intestinal colonisation by pathogenic microorganisms and have anti-carcinogenic, immunostimulatory, and anti-diarrhoeal properties, as well as aiding in the alleviation of lactose intolerance and ability to lower serum cholesterol levels in humans. One particular health promoting property of bifidobacteria is bioactive fatty acid production, which when ingested, may confer health benefits on the host. A bioactive fatty acid produced by bifidobacteria is conjugated linoleic acid (CLA), of which cis-9, trans-11 (c9, t11) and trans-10, cis-12 (t10, c12) CLA are the main biologically active CLA isomers. The production of CLA by Bifidobacterium can also have a positive effect on the immune system of the human host leading to numerous health benefits. This is an example of the metabolic activities of an ingested bacterium being beneficial to the host, rather than the direct interaction of the bacterium with the host. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Drumlins, subglacial meltwater floods, and ocean responses

    Science.gov (United States)

    Shaw, John

    1989-09-01

    Drumlins and erosional marks in bedrock give evidence for broad, subglacial meltwater floods that have discharge-rate estimates of about 106 m3/s. Similar discharge rates are obtained for other late glacial catastrophic floods. The total volume of meltwater that is thought to have formed the Livingstone Lake, Saskatchewan, drumlin field is estimated at 8.4 x 104 km3. This volume is equivalent to a eustatic rise of 0.23 m in global sea level. Meltwater release and roughly contemporaneous formation of drumlin fields in North America and Europe could have involved several metres of sea-level rise in a few years. The implications of such floods for the generation of myths and the interpretation of the oxygen isotopic record of the oceans are discussed. High meltwater discharges are of potential importance to the generation of a lid of cold, fresh water over the North Atlantic and its effects on late glacial climate.

  9. Energy metabolism in osteoclast formation and activity.

    Science.gov (United States)

    Lemma, Silvia; Sboarina, Martina; Porporato, Paolo E; Zini, Nicoletta; Sonveaux, Pierre; Di Pompo, Gemma; Baldini, Nicola; Avnet, Sofia

    2016-10-01

    Osteoclastogenesis and osteolysis are energy-consuming processes supported by high metabolic activities. In human osteoclasts derived from the fusion of monocytic precursors, we found a substantial increase in the number of mitochondria with differentiation. In mature osteoclasts, mitochondria were also increased in size, rich of cristae and arranged in a complex tubular network. When compared with immature cells, fully differentiated osteoclasts showed higher levels of enzymes of the electron transport chain, a higher mitochondrial oxygen consumption rate and a lower glycolytic efficiency, as evaluated by extracellular flux analysis and by the quantification of metabolites in the culture supernatant. Thus, oxidative phosphorylation appeared the main bioenergetic source for osteoclast formation. Conversely, we found that bone resorption mainly relied on glycolysis. In fact, osteoclast fuelling with galactose, forcing cells to depend on Oxidative Phosphorylation by reducing the rate of glycolysis, significantly impaired Type I collagen degradation, whereas non-cytotoxic doses of rotenone, an inhibitor of the mitochondrial complex I, enhanced osteoclast activity. Furthermore, we found that the enzymes associated to the glycolytic pathway are localised close to the actin ring of polarised osteoclasts, where energy-demanding activities associated with bone degradation take place. In conclusion, we demonstrate that the energy required for osteoclast differentiation mainly derives from mitochondrial oxidative metabolism, whereas the peripheral cellular activities associated with bone matrix degradation are supported by glycolysis. A better understanding of human osteoclast energy metabolism holds the potential for future therapeutic interventions aimed to target osteoclast activity in different pathological conditions of bone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Sedentary Activity Associated With Metabolic Syndrome Independent of Physical Activity

    Science.gov (United States)

    Bankoski, Andrea; Harris, Tamara B.; McClain, James J.; Brychta, Robert J.; Caserotti, Paolo; Chen, Kong Y.; Berrigan, David; Troiano, Richard P.; Koster, Annemarie

    2011-01-01

    OBJECTIVE This study examined the association between objectively measured sedentary activity and metabolic syndrome among older adults. RESEARCH DESIGN AND METHODS Data were from 1,367 men and women, aged ≥60 years who participated in the 2003–2006 National Health and Nutrition Examination Survey (NHANES). Sedentary time during waking hours was measured by an accelerometer (5 min. A sedentary break was defined as an interruption in sedentary time (≥100 counts per minute). Metabolic syndrome was defined according to the Adult Treatment Panel (ATP) III criteria. RESULTS On average, people spent 9.5 h (65% of wear time) as sedentary. Compared with people without metabolic syndrome, people with metabolic syndrome spent a greater percentage of time as sedentary (67.3 vs. 62.2%), had longer average sedentary bouts (17.7 vs. 16.7 min), had lower intensity during sedentary time (14.8 vs. 15.8 average counts per minute), and had fewer sedentary breaks (82.3 vs. 86.7), adjusted for age and sex (all P < 0.01). A higher percentage of time sedentary and fewer sedentary breaks were associated with a significantly greater likelihood of metabolic syndrome after adjustment for age, sex, ethnicity, education, alcohol consumption, smoking, BMI, diabetes, heart disease, and physical activity. The association between intensity during sedentary time and metabolic syndrome was borderline significant. CONCLUSIONS The proportion of sedentary time was strongly related to metabolic risk, independent of physical activity. Current results suggest older people may benefit from reducing total sedentary time and avoiding prolonged periods of sedentary time by increasing the number of breaks during sedentary time. PMID:21270206

  11. Metabolic assessments during extra-vehicular activity

    Science.gov (United States)

    Osipov, Yu. Yu.; Spichkov, A. N.; Filipenkov, S. N.

    Extra-vehicular activity (EVA) has a significant role during extended space flights. It demonstrates that humans can survive and perform useful work outside the Orbital Space Stations (OSS) while wearing protective space suits (SS). When the International Space Station 'Alpha'(ISSA) is fully operational, EVA assembly, installation, maintenance and repair operations will become an everyday repetitive work activity in space. It needs new ergonomic evaluation of the work/rest schedule for an increasing of the labor amount per EVA hour. The metabolism assessment is a helpful method to control the productivity of the EVA astronaut and to optimize the work/rest regime. Three following methods were used in Russia to estimate real-time metabolic rates during EVA: 1. Oxygen consumption, computed from the pressure drop in a high pressure bottle per unit time (with actual thermodynamic oxygen properties under high pressure and oxygen leakage taken into account). 2. Carbon dioxide production, computed from CO 2 concentration at the contaminant control cartridge and gas flow rate in the life support subsystem closed loop (nominal mode) or gas leakage in the SS open loop (emergency mode). 3. Heat removal, computed from the difference between the temperatures of coolant water or gas and its flow rate in a unit of time (with assumed humidity and wet oxygen state taken into account). Comparison of heat removal values with metabolic rates enables us to determine the thermal balance during an operative medical control of EVA at "Salyut-6", "Salyut-7" and "Mir" OSS. Complex analysis of metabolism, body temperature and heat rate supports a differential diagnosis between emotional and thermal components of stress during EVA. It gives a prognosis of human homeostasis during EVA. Available information has been acquired into an EVA data base which is an effective tool for ergonomical optimization.

  12. Rock comminution as a source of hydrogen for subglacial ecosystems

    Science.gov (United States)

    Telling, J.; Boyd, E. S.; Bone, N.; Jones, E. L.; Tranter, M.; Macfarlane, J. W.; Martin, P. G.; Wadham, J. L.; Lamarche-Gagnon, G.; Skidmore, M. L.; Hamilton, T. L.; Hill, E.; Jackson, M.; Hodgson, D. A.

    2015-11-01

    Substantial parts of the beds of glaciers, ice sheets and ice caps are at the pressure melting point. The resulting water harbours diverse subglacial microbial ecosystems capable of affecting global biogeochemical cycles. Such subglacial habitats may have acted as refugia during Neoproterozoic glaciations. However, it is unclear how life in subglacial environments could be supported during glaciations lasting millions of years because energy from overridden organic carbon would become increasingly depleted. Here we investigate the potential for abiogenic H2 produced during rock comminution to provide a continual source of energy to support subglacial life. We collected a range of silicate rocks representative of subglacial environments in Greenland, Canada, Norway and Antarctica and crushed them with a sledgehammer and ball mill to varying surface areas. Under an inert atmosphere in the laboratory, we added water, and measured H2 production with time. H2 was produced at 0 °C in all silicate-water experiments, probably through the reaction of water with mineral surface silica radicals formed during rock comminution. H2 production increased with increasing temperature or decreasing silicate rock grain size. Sufficient H2 was produced to support previously measured rates of methanogenesis under a Greenland glacier. We conclude that abiogenic H2 generation from glacial bedrock comminution could have supported life and biodiversity in subglacial refugia during past extended global glaciations.

  13. Physical activity as a metabolic stressor.

    Science.gov (United States)

    Coyle, E F

    2000-08-01

    Both physical activity and diet stimulate processes that, over time, alter the morphologic composition and biochemical function of the body. Physical activity provides stimuli that promote very specific and varied adaptations according to the type, intensity, and duration of exercise performed. There is further interest in the extent to which diet or supplementation can enhance the positive stimuli. Prolonged walking at low intensity presents little metabolic, hormonal, or cardiovascular stress, and the greatest perturbation from rest appears to be from increased fat oxidation and plasma free fatty acid mobilization resulting from a combination of increased lipolysis and decreased reesterification. More intense jogging or running largely stimulates increased oxidation of glycogen and triacylglycerol, both of which are stored directly within the muscle fibers. Furthermore, these intramuscular stores of carbohydrate and fat appear to be the primary substrates for the enhanced oxidative and performance ability derived from endurance training-induced increases in muscle mitochondrial density. Weightlifting that produces fatigue in brief periods (ie, in 15-90 s and after 15 repetitive contractions) elicits a high degree of motor unit recruitment and muscle fiber stimulation. This is a remarkably potent stimulus for altering protein synthesis in muscle and increasing neuromuscular function. The metabolic stress of physical activity can be measured by substrate turnover and depletion, cardiovascular response, hormonal perturbation, accumulation of metabolites, or even the extent to which the synthesis and degradation of specific proteins are altered, either acutely or by chronic exercise training.

  14. Antarctic subglacial lakes drain through sediment-floored canals: theory and model testing on real and idealized domains

    Science.gov (United States)

    Carter, Sasha P.; Fricker, Helen A.; Siegfried, Matthew R.

    2017-02-01

    Over the past decade, satellite observations of ice surface height have revealed that active subglacial lake systems are widespread under the Antarctic Ice Sheet, including the ice streams. For some of these systems, additional observations of ice-stream motion have shown that lake activity can affect ice-stream dynamics. Despite all this new information, we still have insufficient understanding of the lake-drainage process to incorporate it into ice-sheet models. Process models for drainage of ice-dammed lakes based on conventional R-channels incised into the base of the ice through melting are unable to reproduce the timing and magnitude of drainage from Antarctic subglacial lakes estimated from satellite altimetry given the low hydraulic gradients along which such lakes drain. We have developed an alternative process model, in which channels are mechanically eroded into the underlying deformable subglacial sediment. When applied to the known active lakes of the Whillans-Mercer ice-stream system, the model successfully reproduced both the inferred magnitudes and recurrence intervals of lake-volume changes, derived from Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data for the period 2003-2009. Water pressures in our model changed as the flood evolved: during drainage, water pressures initially increased as water flowed out of the lake primarily via a distributed system, then decreased as the channelized system grew, establishing a pressure gradient that drew water away from the distributed system. This evolution of the drainage system can result in the observed internal variability of ice flow over time. If we are correct that active subglacial lakes drain through canals in the sediment, this mechanism also implies that active lakes are typically located in regions underlain by thick subglacial sediment, which may explain why they are not readily observed using radio-echo-sounding techniques.

  15. Metabolically active Crenarchaeota in Altamira Cave.

    Science.gov (United States)

    Gonzalez, Juan M; Portillo, M Carmen; Saiz-Jimenez, Cesareo

    2006-01-01

    Altamira Cave contains valuable paleolithic paintings dating back to 15,000 years. The conservation of these unique paintings is attracting increasing interest, and so, understanding microbial proliferation in Altamira Cave represents a prioritary objective. Here, we show for the first time that members of the Crenarchaeota were metabolically active components of developing microbial communities. RNA was extracted directly from the studied environment, and a number of 16S rRNA gene sequences belonging to the low-temperature Crenarchaeota were detected. Although low-temperature Crenarchaeota detected in a variety of ecosystems by using molecular techniques remain uncultured, this RNA-based study confirms an active participation of the Crenarchaeota in cave biogeochemical cycles.

  16. [Relationship between physical activity and metabolic syndrome].

    Science.gov (United States)

    Yao, Chong-hua; Zuo, Hui-juan; Kong, Ling-zhi; Yang, Xiao-guang; Zhai, Feng-ying

    2006-08-15

    To investigate the relationship between physical activity and metabolic syndrome (MS). A multi-stage stratified cluster sampling was conducted in 132 sampling 218,920 residents, aged 44.3 +/- 15.3 (15 - 96), in the 31 provinces, autonomous regions, and municipalities of the mainland China according to the program of the National Nutrition and Health Survey. Questionnaire survey, interview, physical examination, measurement of biochemical indices, and dietary investigation were done. Information of physical activity and measurement of fasting glucose and/or glucose 2 hours after meal, blood pressure, triglycerides, high-density lipoprotein cholesterol were obtained in 50,494 participants. Metabolic syndrome was defined according to the Chinese Medical Association's definition. The intensity of physical activity was divided into 3 categories according to the Center for Disease Control and Prevention of US/American College of Sports Medicine criteria. 50,495 subjects, 23,932 males (47.4%) and 26,562 females (52.6%), were diagnosed as with MS. The MS incidence of those with high intensity of physical activity was lower by 60% in comparison with those with low intensity of physical activity (odds ratio 0.60, 95% CI: 0.362 - 0.443) adjusted for age, sex, smoking, and alcohol intake. The risk of MS in those with moderate intensity of physical activity of 151 - 300 minutes/week was slightly decreased compared to those with moderate intensity of physical activity of 90 - 150 minutes/week, (odds ratio 0.935, 95% CI: 0.685 - 1.277), however, the risk of MS in those with the moderate intensity of physical activity over 300 minutes/week increased slightly (OR = 1.269, 95% CI: 0.923 - 1.745). The risk of MS in those with low-level physical activity of 301 - 420 minutes/week was lower by 35% in comparison with those with the low-level physical activity of 90 - 150 minutes/week (95% CI: 0.451 - 0.933), however, the risk of MS in those with the low-level physical activity over 420

  17. Microscale evidence of liquefaction and its potential triggers during soft-bed deformation within subglacial traction tills

    Science.gov (United States)

    Phillips, Emrys R.; Evans, David J. A.; van der Meer, Jaap J. M.; Lee, Jonathan R.

    2018-02-01

    Published conceptual models argue that much of the forward motion of modern and ancient glaciers is accommodated by deformation of soft-sediments within the underlying bed. At a microscale this deformation results in the development of a range of ductile and brittle structures in water-saturated sediments as they accommodate the stresses being applied by the overriding glacier. Detailed micromorphological studies of subglacial traction tills reveal that these polydeformed sediments may also contain evidence of having undergone repeated phases of liquefaction followed by solid-state shear deformation. This spatially and temporally restricted liquefaction of subglacial traction tills lowers the shear strength of the sediment and promotes the formation of "transient mobile zones" within the bed, which accommodate the shear imposed by the overriding ice. This process of soft-bed sliding, alternating with bed deformation, facilitates glacier movement by way of 'stick-slip' events. The various controls on the slip events have previously been identified as: (i) the introduction of pressurised meltwater into the bed, a process limited by the porosity and permeability of the till; and (ii) pressurisation of porewater as a result of subglacial deformation; to which we include (iii) episodic liquefaction of water-saturated subglacial traction tills in response to glacier seismic activity (icequakes), which are increasingly being recognized as significant processes in modern glaciers and ice sheets. As liquefaction operates only in materials already at very low values of effective stress, its process-form signatures are likely indicative of glacier sub-marginal tills.

  18. Height changes over subglacial Lake Vostok, East Antarctica: Insights from GNSS observations

    National Research Council Canada - National Science Library

    Richter, Andreas; Popov, Sergey V; Fritsche, Mathias; Lukin, Valery V; Matveev, Alexey Yu; Ekaykin, Alexey A; Lipenkov, Vladimir Ya; Fedorov, Denis V; Eberlein, Lutz; Schröder, Ludwig; Ewert, Heiko; Horwath, Martin; Dietrich, Reinhard

    2014-01-01

    Height changes of the ice surface above subglacial Lake Vostok, East Antarctica, reflect the integral effect of different processes within the subglacial environment and the ice sheet. Repeated GNSS...

  19. Seismic Tremor Reveals Subglacial Discharge at Tidewater Glaciers

    Science.gov (United States)

    Bartholomaus, T. C.; Larsen, C. F.; O'Neel, S.; West, M. E.; Amundson, J. M.; Walter, J. I.; Catania, G. A.; Stearns, L. A.; Walker, R. T.; Sutherland, D.; Shroyer, E.; Nash, J. D.

    2014-12-01

    Subglacial discharge from the termini of tidewater glaciers drives submarine terminus melting, influences fjord circulation, erodes and redeposits subglacial sediment, and is a central component of proglacial marine ecosystems. The timing and variability of subglacial discharge can also exert a strong influence on the upstream flow of tidewater glaciers through hydrology-mediated changes in basal motion. However, a lack of observations of subglacial discharge at the ice-ocean interface hinders progress in understanding these processes and contributes to some of the largest uncertainties in sea level rise projections. Here we demonstrate that passive seismic observations collected adjacent to glaciers can meet this observational need. At tidewater and lake-terminating glaciers in Alaska and Greenland, we observe hourly to seasonal variations in low-amplitude, background seismic noise, termed glacio-hydraulic tremor. Variations in tremor amplitude correlate with discharge during the drainage of a glacially-dammed lake and reveal increases in discharge efficiency over the course of the melt season. Recordings of glacio-hydraulic tremor across a range of settings suggest widespread utility for our method. Reliable prediction of future sea level rise requires observations of subglacial discharge that elicit physical insight and can validate models. Our findings provide a platform for new understanding of ice-ocean interactions and related oceanographic, geologic, and ecological disciplines.

  20. Geophysical investigations of subglacial Antarctic lakes: identifying drill sites for lake access

    Science.gov (United States)

    Woodward, J.; Tulaczyk, S. M.; Smith, A.; Walter, J.; Ross, N.; Fricker, H. A.; Siegert, M. J.; Pettersson, R.; Thoma, M.; Corr, H.; King, E. C.; Vaughan, D.

    2009-12-01

    Subglacial lakes are regarded as viable habitats for novel microbial life forms and may contain sedimentary palaeo-environmental records which would provide critical insights into the glacial history of Antarctica. In-situ sampling and analysis is the only way to explore these lake environments. In order to successfully plan access programs detailed geophysical investigations, in particular seismic measurements of water depth, are required to identify suitable drill sites. Prior to the austral summer of 2006/07 measurements of water depths only existed for Subglacial Lake Vostok, and spatial coverage was limited due to the size of the lake. More recently, active source seismic experiments have been carried out over three subglacial lakes, South Pole Lake, Subglacial Lake Ellsworth (SLE) and Subglacial Lake Whillans (SLW). With drilling programs now funded for SLW (access planned for 2011/12) and SLE (access planned for 2012/13) we present results from the geophysical experiments at SLE and SLW to allow the identification of primary drill sites. The two lakes are very different. Geophysical results from SLE suggest that the lake is over 155 m deep and has been a stable system for much of the Holocene. We propose that in order to optimize the chances of successful access and sampling, the entry site should be located in an area with a melting interface near the centre of the lake where water depths are in the order of 100 m. This is away from the down-lake end which shows a higher possibility for basal freezing, with the consequent risk to equipment deployment and retrieval. In contrast, SLW is characterized by dynamic filling and draining over short (2-3 year periods) and most likely has a shallow water column (currently estimated to be in the order of 5-10 m). We suggest that the most suitable location for access will be the centre of the elevation change anomaly recorded over the lake. This point is near equidistant from the lake shoreline features identified from

  1. Diurnal and water salinity-dependent metabolic activity of juvenile ...

    African Journals Online (AJOL)

    In order to contribute to ecophysiogical data on this species, oxygen consumption by white steenbras was determined to quantify metabolic activity. White steenbras were most active during daylight hours when oxygen consumption was 28% higher than during the scotophase. Standard, routine and active metabolic rate ...

  2. PREDICTED SEDIMENTARY SECTION OF SUBGLACIAL LAKE VOSTOK

    Directory of Open Access Journals (Sweden)

    G. I. Leychenkov

    2012-01-01

    Full Text Available In early February 2012, the drill hole at the Vostok Station encountered theLakeVostokwater. This step is important to study the lake composition including possible microbial life and to model subglacial environments however, the next ambitious target of the Vostok Drilling Project is sampling of bottom sediments, which contain the unique record of ice sheet evolution and environmental changes in centralAntarcticafor millions of years. In this connection, the forecast of sedimentary succession based on existing geophysical data, study of mineral inclusions in the accretion ice cores and tectonic models is important task. Interpretation of Airborne geophysical data suggests thatLakeVostokis the part of spacious rift system, which exists at least from Cretaceous. Reflection and refraction seismic experiments conducted in the southern part ofLakeVostokshow very thin (200–300 m stratified sedimentary cover overlying crystalline basement with velocity of 6.0–6.2 km/s. At present, deposition in southernLakeVostokis absent and similar conditions occurred likely at least last3 m.y. when ice sheet aboveLakeVostokchanged insignificantly. It can be also inferred that from the Late Miocene the rate of deposition inLakeVostokwas extremely low and so the most of sedimentary section is older being possibly of Oligocene to early to middle Miocene age when ice sheet oscillated and deposition was more vigorous. If so, the sampling of upper few meters of this condensed section is very informative in terms of history of Antarctic glaciation. Small thickness of sedimentary cover raises a question about existence of lake (rift depression during preglacial and early glacial times.

  3. Physical activity behaviour in patients with metabolic syndrome

    OpenAIRE

    Murer, M; Schmied, C; Battegay, E; Keller, D I

    2012-01-01

    STUDY/PRINCIPLES: Physical activity improves the clinical course of the metabolic syndrome and its risk factors. The aim of this study was to investigate the physical activity behaviour in patients with metabolic syndrome in regard to the recommendation of the Federal Offices of Public Health (BAG) and Sports (BASPO): “to exercise half an hour a day at a medium intensity.” METHODS: 47 patients with metabolic syndrome were recruited from the Outpatient Department of the Division of Internal Me...

  4. The association between physical activity and the metabolic ...

    African Journals Online (AJOL)

    The association between physical activity and the metabolic syndrome among type 2 diabetes patients in Gaza strip, Palestine. ... Conclusion: We conclude that low levels of physical activity are associated with increased prevalence of metabolic syndrome. Furthermore, inactive patients had a high percentage of diabetes ...

  5. Physical activity patterns and metabolic syndrome in Costa Rica.

    Science.gov (United States)

    Hastert, Theresa A; Gong, Jian; Campos, Hannia; Baylin, Ana

    2015-01-01

    To examine whether total physical activity or activity patterns are associated with metabolic syndrome and its components. Participants include 1994 controls from a case-control study of non-fatal myocardial infarction in Costa Rica (1994-2004). Physical activity was assessed via self-administered questionnaire and patterns were identified using principal components analysis. Metabolic syndrome was assessed via blood samples and anthropometry measurements from in-home study visits. Prevalence ratios (PRs) and 95% confidence intervals (CIs) were calculated using log binomial regression. Adjusted least squares means of metabolic syndrome components were calculated by quintile of total activity and pattern scores. Four activity patterns were identified: rest/sleep, agricultural, light indoor activity, and manual labor. Total activity was not associated with metabolic syndrome. Metabolic syndrome prevalence was 20% lower in participants with the highest scores on the agricultural job pattern compared to those with the lowest (PR: 0.80, 95% CI: 0.68-0.94). Higher total activity was associated with lower triglycerides and lower HDL cholesterol. Higher scores on each pattern were inversely associated with metabolic syndrome components, particularly waist circumference and fasting blood glucose. Patterns or types of physical activity may be more strongly associated with metabolic syndrome and its components than total activity levels. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Metabolic signals and innate immune activation in obesity and exercise

    National Research Council Canada - National Science Library

    Ringseis, Robert; Eder, Klaus; Mooren, Frank C; Krüger, Karsten

    2015-01-01

    ... being indicative of activation of the innate immune system. Recent evidence suggests that activation of the innate immune system in the course of obesity is mediated by metabolic signals, such as free fatty acids (FFAs...

  7. Geology and environments of subglacial Lake Vostok.

    Science.gov (United States)

    Leitchenkov, German L; Antonov, Anton V; Luneov, Pavel I; Lipenkov, Vladimir Ya

    2016-01-28

    The reconstruction of the geological (tectonic) structure and environments of subglacial Lake Vostok is based on geophysical surveys and the study of mineral particles found in cores of accreted ice and frozen lake water (sampled after the lake was unsealed). Seismic reflection and refraction investigations conducted in the southern part of Lake Vostok show very thin (200-300 m) sedimentary cover overlying a crystalline basement. Most of this thin veneer is thought to have been deposited during temperate-glacial conditions in Oligocene to Middle Miocene time (ca 34-14 Ma). The composition of the lake-bottom sediments can be deduced from mineral inclusions found in cores of accreted ice. Inclusions are represented by soft aggregates consisting mainly of clay-mica minerals and micrometre-sized quartz grains. Some of these inclusions contain subangular to semi-rounded rock clasts (siltstones and sandstones) ranging from 0.3 to 8 mm in size. In total, 31 zircon grains have been identified in two rock clasts and dated using SHRIMP-II. The ages of the studied zircons range from 0.6 to 2.0 Ga with two distinct clusters between 0.8 and 1.15 Ga and between 1.6 and 1.8 Ga. Rock clasts obviously came from the western lake shore, which is thus composed of terrigenous strata with an age of not older than 600 Ma. The sedimentary nature of the western lake shore is also confirmed by seismic refraction data showing seismic velocities there of 5.4-5.5 km s(-1) at the bedrock surface. After Lake Vostok was unsealed, its water (frozen and sampled next season) was also studied with scanning electron microscopy and X-ray microprobe analysis. This study showed the existence of calcium carbonate and silica microparticles (10-20 μm across) in frozen water. © 2015 The Author(s).

  8. Coupling autotrophic sulfide mineral weathering with dolomite dissolution in a subglacial ecosystem

    Science.gov (United States)

    Boyd, E. S.; Hamilton, T. L.; Havig, J. R.; Lange, R.; Murter, E.; Skidmore, M. L.; Peters, J.; Shock, E.

    2013-12-01

    Evidence in the rock record suggests that glaciers have been present and covered a significant portion of the Earth's surface since the putative Mozaan Glaciation (circa 2.9 Ga) and were demonstrated recently to host active microbial communities that impact local and global biogeochemical cycles. In the present study, we applied a microcosm-based radioisotopic biocarbonate tracer approach to quantify rates of inorganic carbon assimilation in sediments sampled from beneath Robertson Glacier (RG), Alberta, Canada at 4°C. Rates of inorganic carbon assimilation were stimulated by the addition of ammonium and phosphate, suggesting that these nutrients might be of limited supply in the subglacial environment or, in the case of ammonia, might be serving as a source of reductant fueling inorganic carbon fixation. Geochemical analyses were used to assess the potential redox couples that might be fueling autotrophic activity. The difference in the concentration of sulfate (2.4 mM) in unamended microcosm fluids when compared to fluids sampled from killed controls following 180 days incubation suggests that inorganic carbon assimilation in microcosms is driven by microbial populations involved in the oxidation of mineral sulfides, most likely pyrite. Amendment of microcosms with 1 mM ammonia led to near stoichiometric production of nitrate (~890 μM) and lower production of sulfate (~1.5 mM), indicating that the enhanced activity observed in ammonia treated microcosms is likely due to the stimulation of autotrophic ammonia oxidizing populations. The isotopic composition of dissolved organic carbon in subglacial meltwaters ranged was -24.40 ‰ versus VPDB, which is consistent with a source for this organic carbon via the activity of autotrophs that use the Calvin cycle of inorganic carbon fixation. Quantification and sequencing of transcripts of Calvin cycle biomarker genes (ribulose-1,5 bisphosphate carboxylase/oxygenase, encoded by cbbL) suggest the presence of a ubiquitous

  9. Subglacial biochemical weathering and transport drove fertilization in the Southern Ocean during Antarctic temperature maxima and NH Heinrich events

    Science.gov (United States)

    Frisia, S.; Augustinus, P. M.; Hellstrom, J.; Borsato, A.; Drysdale, R.; Weyrich, L.; Cooper, A.; Johnston, V. E.; Cotte, M.

    2013-12-01

    Changes in bioproductivity in the subantarctic region have been observed to coincide with episodes of significant iceberg discharge in the North Atlantic (Heinrich events), thus linking iron delivery to the Southern Ocean (SO) with abrupt climate changes in the Northern Hemisphere. Whilst upwelling has been proposed as a likely source of bioavailable iron during Heinrich events, it is well known that, today, subglacial metabolic pathways under limited carbon supply may accumulate divalent iron, which could have been mobilized and delivered to the SO during full glacial conditions. This alternative hypothesis remains largely untested for the SO because of the difficulties in accessing palaeoenvironmental archives from beneath the Antarctic ice sheets. We present a record of the subglacial production and fate of nutrients from calcite crusts formed beneath a tributary of the Rennick outlet glacier (East Antarctic Ice Sheet, EAIS) during the Last Glacial Maximum. Chemistry, stratigraphy and preliminary ancient DNA characterization of the microbial consortium of 27- to 17-kyr-old calcites suggest that bioweathering released iron in hypoxic pools of local basal meltwater. Anaerobic methane oxidising microbes released bicarbonate and sulfuric acid in the isolated pockets, which facilitated local weathering of the amphibolite rock. During episodes of channelized flow, identified by clast-rich microsparites, and which have ages near-commensurate with Antarctic Isotope Maximum2 (AIM2) and Heinrich event 2, ferrous iron may have been mobilized and transported subglacially to the ice shelf. The calcites formed during this phase preserve evidence of microbes using sulfite dehydrogenase, which explains the accumulation of sulfate in the calcite. Our data thus indicate that subglacial processes contributed to SO productivity increases at the time of Heinrich event 2, ultimately leading to drawdawn of atmospheric carbon dioxide at millennial scale.

  10. Ice thickness, volume and subglacial topography of Urumqi Glacier ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 123; Issue 3. Ice thickness, volume and subglacial topography of Urumqi Glacier No. 1, Tianshan mountains, central Asia, by ground penetrating radar survey. Puyu Wang Zhongqin Li Shuang Jin Ping Zhou Hongbing Yao Wenbin Wang. Volume 123 Issue 3 April ...

  11. A wireless subglacial probe for deep ice applications

    NARCIS (Netherlands)

    Smeets, C.J.P.P.|info:eu-repo/dai/nl/191522236; Boot, W.; Hubbard, A.; Pettersson, R.; Wilhelms, F.; van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; van de Wal, R.S.W.|info:eu-repo/dai/nl/101899556

    2012-01-01

    We present the design and first results from two experiments using a wireless subglacial sensor system (WiSe) that is able to transmit data through 2500m thick ice. Energy consumption of the probes is minimized, enabling the transmission of data for at least 10 years. In July 2010 the first

  12. Incorporating modelled subglacial hydrology into inversions for basal drag

    Directory of Open Access Journals (Sweden)

    C. P. Koziol

    2017-12-01

    Full Text Available A key challenge in modelling coupled ice-flow–subglacial hydrology is initializing the state and parameters of the system. We address this problem by presenting a workflow for initializing these values at the start of a summer melt season. The workflow depends on running a subglacial hydrology model for the winter season, when the system is not forced by meltwater inputs, and ice velocities can be assumed constant. Key parameters of the winter run of the subglacial hydrology model are determined from an initial inversion for basal drag using a linear sliding law. The state of the subglacial hydrology model at the end of winter is incorporated into an inversion of basal drag using a non-linear sliding law which is a function of water pressure. We demonstrate this procedure in the Russell Glacier area and compare the output of the linear sliding law with two non-linear sliding laws. Additionally, we compare the modelled winter hydrological state to radar observations and find that it is in line with summer rather than winter observations.

  13. Modeling of subglacial hydrological development following rapid supraglacial lake drainage

    Science.gov (United States)

    Dow, C. F.; Kulessa, B.; Rutt, I. C.; Tsai, V. C.; Pimentel, S.; Doyle, S. H.; van As, D.; Lindbäck, K.; Pettersson, R.; Jones, G. A.; Hubbard, A.

    2015-06-01

    The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections.

  14. Subglacial sediment mechanics investigated by computer simulation of granular material

    Science.gov (United States)

    Damsgaard, A.; Egholm, D. L.; Tulaczyk, S. M.; Piotrowski, J. A.; Larsen, N. K.; Siegfried, M. R.; Beem, L.; Suckale, J.

    2016-12-01

    The mechanical properties of subglacial sediments are known to directly influence the stability of ice streams and fast-moving glaciers, but existing models of granular sediment deformation are poorly constrained. In addition, upscaling to generalized mathematical models is difficult due to the mechanical nonlinearity of the sediment, internal porosity changes during deformation, and associated structural and kinematic phase transitions. In this presentation, we introduce the Discrete Element Method (DEM) for particle-scale granular simulation. The DEM is fully coupled with fluid dynamics. The numerical method is applied to better understand the mechanical properties of the subglacial sediment and its interaction with meltwater. The computational approach allows full experimental control and offers insights into the internal kinematics, stress distribution, and mechanical stability. During confined shear with variable pore-water pressure, the sediment changes mechanical behavior, from stick, to non-linear creep, and unconstrained failure during slip. These results are contrary to more conventional models of plastic or (non-)linear viscous subglacial soft-bed sliding. Advection of sediment downstream is pressure dependent, which is consistent with theories of unstable bed bump growth. Granular mechanics prove to significantly influence the geometry and hydraulic properties of meltwater channels incised into the subglacial bed. Current models assume that channel bed erosion is balanced by linear-viscous sediment movement. We demonstrate how channel flanks are stabilized by the sediment frictional strength. Additionally, sediment liquefaction proves to be a possible mechanism for causing large and episodic sediment transport by water flow. Though computationally intense, our coupled numerical method provides a framework for quantifying a wide range of subglacial sediment-water processes, which are a key unknown in our ability to model the future evolution of ice

  15. Clean access, measurement, and sampling of Ellsworth Subglacial Lake: A method for exploring deep Antarctic subglacial lake environments

    Science.gov (United States)

    Siegert, Martin J.; Clarke, Rachel J.; Mowlem, Matt; Ross, Neil; Hill, Christopher S.; Tait, Andrew; Hodgson, Dominic; Parnell, John; Tranter, Martyn; Pearce, David; Bentley, Michael J.; Cockell, Charles; Tsaloglou, Maria-Nefeli; Smith, Andy; Woodward, John; Brito, Mario P.; Waugh, Ed

    2012-01-01

    Antarctic subglacial lakes are thought to be extreme habitats for microbial life and may contain important records of ice sheet history and climate change within their lake floor sediments. To find whether or not this is true, and to answer the science questions that would follow, direct measurement and sampling of these environments are required. Ever since the water depth of Vostok Subglacial Lake was shown to be >500 m, attention has been given to how these unique, ancient, and pristine environments may be entered without contamination and adverse disturbance. Several organizations have offered guidelines on the desirable cleanliness and sterility requirements for direct sampling experiments, including the U.S. National Academy of Sciences and the Scientific Committee on Antarctic Research. Here we summarize the scientific protocols and methods being developed for the exploration of Ellsworth Subglacial Lake in West Antarctica, planned for 2012-2013, which we offer as a guide to future subglacial environment research missions. The proposed exploration involves accessing the lake using a hot-water drill and deploying a sampling probe and sediment corer to allow sample collection. We focus here on how this can be undertaken with minimal environmental impact while maximizing scientific return without compromising the environment for future experiments.

  16. Seismicity and Subglacial Hydrological Processes During Early Melt Season, Engabreen, Norway

    Science.gov (United States)

    Moore, P. L.; Winberry, J.; Christianson, K.; Iverson, N. R.; Anandakrishnan, S.; Jackson, M.; Cohen, D. O.

    2012-12-01

    A broad array of mechanical and seismic instrumentation was deployed during May 2011 in subglacial tunnels beneath Engabreen, an outlet glacier of the Svartisen ice cap in northern Norway. Following a warm spell, increased melt supply to the glacier bed prompted several episodes of transient ice uplift and establishment of a more efficient basal hydraulic system. In each event, hydrological adjustment was accompanied by three distinct seismic sources, two of which have not been previously documented in glacial environments. High-frequency impulsive events with dominant Rayleigh-wave energy increased their rate-of-occurrence immediately prior to an abrupt change in basal water pressure and normal stress. These events are inferred represent propagation of water-filled crevasses permitting meltwater access to the bed. Ultra-long period (ULP, hydraulic jacking. During recovery of basal water pressure, vertical ULP deflections were correlated with increases in basal water flux and doubling of local subglacial seismic noise. The increase in seismic noise may represent turbulent flow and bedload sediment transport through newly-opened subglacial meltwater passages. The vertical ULP signal therefore likely reflects meltwater-forced uplift of ice. Surprisingly, although there was direct evidence that jacking activated frictional slip at the bed, there was no clear seismic expression of slip. Thus, broadband seismometers appear to have captured the transit of meltwater through crevasses, into isolated pockets at the glacier bed and then, by promoting ice uplift, draining though newly-established meltwater passages along the bed. Similar seismic sources could be detected elsewhere with strategically-located broadband seismic instrumentation, providing a means of remotely monitoring the hydrological processes that control ice motion.

  17. Unveiling subglacial geology and crustal architecture in the Recovery frontier of East Antarctica with recent aeromagnetic and airborne gravity imaging

    Science.gov (United States)

    Ferraccioli, F.; Forsberg, R.; Jordan, T. A.; Matsuoka, K.; Olsen, A.; King, O.; Ghidella, M.

    2014-12-01

    East Antarctica is the least known continent, despite being a keystone in the Gondwana, Rodinia and Columbia supercontinents. Significant progress has been made in recent years in exploring East Antarctica using aeromagnetic and airborne gravity together with radar. Major aerogeophysical campaigns over the Wilkes Subglacial Basin (Ferraccioli et al., 2009 Tectonophysics), the Aurora Subglacial Basin (Aitken et al., 2014 GRL) and the Gamburtsev Subglacial Mountains (Ferraccioli et al., 2011, Nature) provide new glimpses into the crustal architecture of East Antarctica. However, a major sector of the continent that includes key piercing points for reconstructing linkages between East Antarctica and Laurentia within Rodinia, and also the inferred remnants of a major suture zone active during Gondwana amalgamation in Pan-African times (ca 500 Ma), has remained largely terra incognita. Here we present the results of a major aerogeophysical survey flown over this sector of East Antarctica, named the Recovery Frontier, from the major ice stream flowing in the region. The survey was flown during the IceGRAV 2012-13 field season, as part of a Danish-Norwegian-UK and Argentine collaboration and led to the collection of 29,000 line km of radar, laser altimetry, gravity and magnetic data. We present the new aeromagnetic anomaly, Bouguer and residual and enhanced anomaly maps for the region. Using these images we trace the extent of major subglacial faults and interpret these to delineate the tectonic boundaries separating the Coast block, the Shackleton Range and the Dronning Maud Land crustal provinces. Forward magnetic and gravity modelling enables us to examine the inferred Pan-African age suture zone in the Shackleton Range and address its tectonic relationships with older terranes of the Mawson Craton and Grenvillian-age terranes of Dronning Maud Land and interior East Antarctica. Finally, we present new models to test our hypothesis that Paleozoic to Mesozoic rift basins

  18. Obesity, Metabolic Syndrome, and Physical Activity.

    Science.gov (United States)

    Yeater, Rachel

    2000-01-01

    Discusses the scope of the problem of obesity in the United States, noting the health risks associated with being overweight or obese (e.g., gallstones, osteoarthritis, sleep apnea, and colon cancer); discussing the association of type-II diabetes mellitus with obesity; examining the effects of exercise on metabolic disease; and looking at…

  19. Physical activity, cardiorespiratory fitness, and the metabolic syndrome in youth.

    Science.gov (United States)

    Steele, Rebekah M; Brage, Soren; Corder, Kirsten; Wareham, Nicholas J; Ekelund, Ulf

    2008-07-01

    The metabolic syndrome is defined as the coexistence of multiple cardiovascular and diabetes risk factors, the prevalence of which has increased dramatically in adult populations in the last decades. More recently, the same cluster of metabolic risk factors has also been recognized in children and adolescents. Epidemiological evidence suggests that high levels of cardiorespiratory fitness (CRF) and physical activity are associated with a favorable metabolic risk profile in adults. However, in youth the role of these factors is less clear. Therefore, the purpose of this mini-review is to examine the recent evidence between objectively measured habitual physical activity and CRF with clustered metabolic risk in youth. In general, it appears that both physical activity and CRF are separately and independently associated with metabolic risk factors in youth, possibly through different causal pathways. Further research is necessary to quantify how much physical activity is needed to prevent the metabolic syndrome and the diseases with which it is associated. Public health approaches that encourage increased physical activity and reduce sedentary behaviors may prove useful in reducing the population burden associated with metabolic risk.

  20. The Activity Reaction Core and Plasticity of Metabolic Networks.

    Directory of Open Access Journals (Sweden)

    2005-12-01

    Full Text Available Understanding the system-level adaptive changes taking place in an organism in response to variations in the environment is a key issue of contemporary biology. Current modeling approaches, such as constraint-based flux-balance analysis, have proved highly successful in analyzing the capabilities of cellular metabolism, including its capacity to predict deletion phenotypes, the ability to calculate the relative flux values of metabolic reactions, and the capability to identify properties of optimal growth states. Here, we use flux-balance analysis to thoroughly assess the activity of Escherichia coli, Helicobacter pylori, and Saccharomyces cerevisiae metabolism in 30,000 diverse simulated environments. We identify a set of metabolic reactions forming a connected metabolic core that carry non-zero fluxes under all growth conditions, and whose flux variations are highly correlated. Furthermore, we find that the enzymes catalyzing the core reactions display a considerably higher fraction of phenotypic essentiality and evolutionary conservation than those catalyzing noncore reactions. Cellular metabolism is characterized by a large number of species-specific conditionally active reactions organized around an evolutionary conserved, but always active, metabolic core. Finally, we find that most current antibiotics interfering with bacterial metabolism target the core enzymes, indicating that our findings may have important implications for antimicrobial drug-target discovery.

  1. Evidence for Subglacial Deformation and Deposition during a Complete Advance-Stagnation Cycle of Kötlujökull, Iceland – A Case Study

    DEFF Research Database (Denmark)

    2010-01-01

    deformation and deposition from dynamically active ice, (4) subglacial deposition from stagnant ice and (5) supraglacial re-deposition in dead-ice environment during de-icing. This complete sedimentary sequence represents a single glacier advance-stagnation cycle. The melt-out till displays moderate...

  2. Microbial sulfur transformations in sediments from Subglacial Lake Whillans

    Directory of Open Access Journals (Sweden)

    Alicia M Purcell

    2014-11-01

    Full Text Available Diverse microbial assemblages inhabit subglacial aquatic environments. While few of these environments have been sampled, data reveal that subglacial organisms gain energy for growth from reduced minerals containing nitrogen, iron, and sulfur. Here we investigate the role of microbially mediated sulfur transformations in sediments from Subglacial Lake Whillans (SLW, Antarctica, by examining key genes involved in dissimilatory sulfur oxidation and reduction. The presence of sulfur transformation genes throughout the top 34 cm of SLW sediments changes with depth. SLW surficial sediments were dominated by genes related to known sulfur-oxidizing chemoautotrophs. Sequences encoding the adenosine-5’-phosphosulfate (APS reductase gene, involved in both dissimilatory sulfate reduction and sulfur oxidation, were present in all samples and clustered into 16 distinct OTUs. The majority of APS reductase sequences (74% clustered with known sulfur oxidizers including those within the Sideroxydans and Thiobacillus genera. Reverse-acting dissimilatory sulfite reductase (rDSR and 16S rRNA gene sequences further support dominance of Sideroxydans and Thiobacillus phylotypes in the top 2 cm of SLW sediments. The SLW microbial community has the genetic potential for sulfate reduction which is supported by experimentally measured low rates (1.4 pmol cm-3d-1 of biologically mediated sulfate reduction and the presence of APS reductase and DSR gene sequences related to Desulfobacteraceae and Desulfotomaculum. Our results also infer the presence of sulfur oxidation, which can be a significant energetic pathway for chemosynthetic biosynthesis in SLW sediments. The water in SLW ultimately flows into the Ross Sea where intermediates from subglacial sulfur transformations can influence the flux of solutes to the Southern Ocean.

  3. Subglacial hydrological modelling of a rapid lake drainage event on the Russell Glacier catchment, SW Greenland

    Science.gov (United States)

    Dow, C. F.; Pimentel, S.; Doyle, S. H.; Booth, A. D.; Fitzpatrick, A.; Jones, G. A.; Kulessa, B.; Hubbard, A.

    2011-12-01

    We use local-scale subglacial hydrological models to assess the development of the basal drainage system in response to a rapid lake-tapping event on the Russell Glacier catchment, SW Greenland. Water inputs to the model are constrained by in-situ records of the lake drainage rate. Subglacial conditions are estimated from active seismic line analysis including basal topography and substrate characteristics. A borehole slug test model is used to determine the radial flux of water from the drainage input point. Water flowing in the downstream direction is used to drive a 1-D flowband model, which allows development of interacting channelised and distributed drainage systems. The simulated basal water pressures are applied to an elastic beam model to assess vertical uplift at the lake drainage site. Modelled uplift outputs are compared with results from GPS stations located next to the lake. Initial modelling results suggest that channels are necessary for evacuation of water from rapid lake drainage events, even with the presence of a sediment-based bed, the latter of which is usually associated with distributed drainage.

  4. A confined-unconfined aquifer model for subglacial hydrology

    Science.gov (United States)

    Beyer, Sebastian; Kleiner, Thomas; Humbert, Angelika

    2017-04-01

    Modeling the evolution of subglacial channels underneath ice sheets is an urgent need for ice sheet modellers, as channels affect sliding velocities and hence ice discharge. Owing to very limited observations of the subglacial hydraulic system, the development of physical models is quite restricted. Subglacial hydrology models are currently taking two different approaches: either modeling the development of a network of individual channels or modeling an equivalent porous layer where the channels are not resolved individually but modeled as a diffusive process, adjusted to reproduce the characteristic of an efficient system. Here, we use the latter approach, improving it by using a confined-unconfined aquifer model (CUAS), that allows the system to run dry in absence of sufficient water input. This ensures physical values for the water pressure. Channels are represented by adjusting the permeability and storage of the system according to projected locations of channels. The evolution of channel positions is governed by a reduced complexity model that computes channel growths according to simple rules (weighted random walks descending the hydraulic potential). As a proof of concept we present the results of the evolution of the hydrological system over time for a simple artificial glacier geometry.

  5. Constraining local subglacial bedrock erosion rates with cosmogenic nuclides

    Science.gov (United States)

    Wirsig, Christian; Ivy-Ochs, Susan; Christl, Marcus; Reitner, Jürgen; Reindl, Martin; Bichler, Mathias; Vockenhuber, Christof; Akcar, Naki; Schlüchter, Christian

    2014-05-01

    The constant buildup of cosmogenic nuclides, most prominently 10Be, in exposed rock surfaces is routinely employed for dating various landforms such as landslides or glacial moraines. One fundamental assumption is that no cosmogenic nuclides were initially present in the rock, before the event to be dated. In the context of glacially formed landscapes it is commonly assumed that subglacial erosion of at least a few meters of bedrock during the period of ice coverage is sufficient to remove any previously accumulated nuclides, since the production of 10Be ceases at a depth of 2-3 m. Insufficient subglacial erosion leads to overestimation of surface exposure ages. If the time since the retreat of the glacier is known, however, a discordant concentration of cosmogenic nuclides delivers information about the depth of subglacial erosion. Here we present data from proglacial bedrock at two sites in the Alps. Goldbergkees in the Hohe Tauern National Park in Austria and Gruebengletscher in the Grimsel Pass area in Switzerland. Samples were taken inside as well as outside of the glaciers' Little Ice Age extent. Measured nuclide concentrations are analyzed with the help of a MATLAB model simulating periods of exposure or glacial cover of user-definable length and erosion rates.

  6. Subglacial discharge-driven renewal of tidewater glacier fjords

    Science.gov (United States)

    Carroll, Dustin; Sutherland, David A.; Shroyer, Emily L.; Nash, Jonathan D.; Catania, Ginny A.; Stearns, Leigh A.

    2017-08-01

    The classic model of fjord renewal is complicated by tidewater glacier fjords, where submarine melt and subglacial discharge provide substantial buoyancy forcing at depth. Here we use a suite of idealized, high-resolution numerical ocean simulations to investigate how fjord circulation driven by subglacial plumes, tides, and wind stress depends on fjord width, grounding line depth, and sill height. We find that the depth of the grounding line compared to the sill is a primary control on plume-driven renewal of basin waters. In wide fjords the plume exhibits strong lateral recirculation, increasing the dilution and residence time of glacially-modified waters. Rapid drawdown of basin waters by the subglacial plume in narrow fjords allows for shelf waters to cascade deep into the basin; wide fjords result in a thin, boundary current of shelf waters that flow toward the terminus slightly below sill depth. Wind forcing amplifies the plume-driven exchange flow; however, wind-induced vertical mixing is limited to near-surface waters. Tidal mixing over the sill increases in-fjord transport of deep shelf waters and erodes basin stratification above the sill depth. These results underscore the first-order importances of fjord-glacier geometry in controlling circulation in tidewater glacier fjords and, thus, ocean heat transport to the ice.

  7. What controls the explosivity of subglacial rhyolite in Iceland?

    Science.gov (United States)

    Owen, J.; Tuffen, H.; McGarvie, D. W.

    2012-04-01

    The eruption controls of subglacial rhyolite are poorly understood but this is of key importance in mitigating hazards. In subaerial rhyolite eruptions the pre-eruptive volatile content and degassing path are considered to be the primary controls of explosivity, but is this also the case when rhyolitic eruptions occur under ice? We present the first pre-eruptive volatile content and degassing path data for subglacial rhyolite eruptions, comparing three edifices of contrasting eruption style from the Torfajökull complex in South Iceland[1]. Volatile concentrations were measured using infra-red spectroscopy (FTIR) and Secondary Ion Mass Spectroscopy (SIMS). SE Rauðfossafjöll is a large volume (~1 km3) explosively erupted tuya, Dalakvísl (~0.2 km3) is an entirely subglacial edifice that has both explosive and effusive deposits and Bláhnúkur is a small volume (Bull Vol. [3] Tuffen et al. (2007) Ann Glac, 45(1): 87-94

  8. A lander mission to probe subglacial water on Saturn's moon Enceladus for life

    Science.gov (United States)

    Konstantinidis, Konstantinos; Flores Martinez, Claudio L.; Dachwald, Bernd; Ohndorf, Andreas; Dykta, Paul; Bowitz, Pascal; Rudolph, Martin; Digel, Ilya; Kowalski, Julia; Voigt, Konstantin; Förstner, Roger

    2015-01-01

    The plumes discovered by the Cassini mission emanating from the south pole of Saturn's moon Enceladus and the unique chemistry found in them have fueled speculations that Enceladus may harbor life. The presumed aquiferous fractures from which the plumes emanate would make a prime target in the search for extraterrestrial life and would be more easily accessible than the moon's subglacial ocean. A lander mission that is equipped with a subsurface maneuverable ice melting probe will be most suitable to assess the existence of life on Enceladus. A lander would have to land at a safe distance away from a plume source and melt its way to the inner wall of the fracture to analyze the plume subsurface liquids before potential biosignatures are degraded or destroyed by exposure to the vacuum of space. A possible approach for the in situ detection of biosignatures in such samples can be based on the hypothesis of universal evolutionary convergence, meaning that the independent and repeated emergence of life and certain adaptive traits is wide-spread throughout the cosmos. We thus present a hypothetical evolutionary trajectory leading towards the emergence of methanogenic chemoautotrophic microorganisms as the baseline for putative biological complexity on Enceladus. To detect their presence, several instruments are proposed that may be taken aboard a future subglacial melting probe. The "Enceladus Explorer" (EnEx) project funded by the German Space Administration (DLR), aims to develop a terrestrial navigation system for a subglacial research probe and eventually test it under realistic conditions in Antarctica using the EnEx-IceMole, a novel maneuverable subsurface ice melting probe for clean sampling and in situ analysis of ice and subglacial liquids. As part of the EnEx project, an initial concept study is foreseen for a lander mission to Enceladus to deploy the IceMole near one of the active water plumes on the moon's South-Polar Terrain, where it will search for

  9. Peroxisome Proliferators-Activated Receptor (PPAR Modulators and Metabolic Disorders

    Directory of Open Access Journals (Sweden)

    Min-Chul Cho

    2008-01-01

    Full Text Available Overweight and obesity lead to an increased risk for metabolic disorders such as impaired glucose regulation/insulin resistance, dyslipidemia, and hypertension. Several molecular drug targets with potential to prevent or treat metabolic disorders have been revealed. Interestingly, the activation of peroxisome proliferator-activated receptor (PPAR, which belongs to the nuclear receptor superfamily, has many beneficial clinical effects. PPAR directly modulates gene expression by binding to a specific ligand. All PPAR subtypes (α,γ, and σ are involved in glucose metabolism, lipid metabolism, and energy balance. PPAR agonists play an important role in therapeutic aspects of metabolic disorders. However, undesired effects of the existing PPAR agonists have been reported. A great deal of recent research has focused on the discovery of new PPAR modulators with more beneficial effects and more safety without producing undesired side effects. Herein, we briefly review the roles of PPAR in metabolic disorders, the effects of PPAR modulators in metabolic disorders, and the technologies with which to discover new PPAR modulators.

  10. Sleep Slow-Wave Activity Regulates Cerebral Glycolytic Metabolism

    OpenAIRE

    Wisor, Jonathan P; Rempe, Michael J; Schmidt, Michelle A.; Moore, Michele E.; Clegern, William C.

    2012-01-01

    Non-rapid eye movement sleep (NREMS) onset is characterized by a reduction in cerebral metabolism and an increase in slow waves, 1–4-Hz oscillations between relatively depolarized and hyperpolarized states in the cerebral cortex. The metabolic consequences of slow-wave activity (SWA) at the cellular level remain uncertain. We sought to determine whether SWA modulates the rate of glycolysis within the cerebral cortex. The real-time measurement of lactate concentration in the mouse cerebral cor...

  11. Physical Activity, Metabolic Syndrome, and Overweight in Rural Youth

    Science.gov (United States)

    Moore, Justin B.; Davis, Catherine L.; Baxter, Suzanne Domel; Lewis, Richard D.; Yin, Zenong

    2008-01-01

    Background: Research suggests significant health differences between rural dwelling youth and their urban counterparts with relation to cardiovascular risk factors. This study was conducted to (1) determine relationships between physical activity and markers of metabolic syndrome, and (2) to explore factors relating to physical activity in a…

  12. Effect of physical activity on glutamine metabolism.

    Science.gov (United States)

    Agostini, Francesco; Biolo, Gianni

    2010-01-01

    Glutamine is largely synthesized in skeletal muscles and provides fuel to rapidly dividing cells of the immune system and precursors to gluconeogenesis in the liver. Physical exercise is known to affect glutamine synthesis and to modulate glutamine uptake. Overtraining is frequently associated with reduced availability of glutamine and decreased immunocompetence. Inactivity affects glutamine metabolism, but this subject was poorly investigated. Strenuous physical exercise as well as exhaustive training programs lead to glutamine depletion due to lowered synthesis and enhanced uptake by liver and immune cells. Evidence suggests that postexercise glutamine depletion is associated with immunodepression. Counterwise, moderate training leads to improved glutamine availability due to a positive balance between muscle synthesis and peripheral clearance. Physical inactivity, as investigated by experimental bed rest in healthy volunteers, reduced glutamine synthesis and availability. After exercise, a reduced glutamine availability may be considered as a marker of overtraining. An increased glutamine availability may contribute to decreased inflammation and health benefits associated with optimal training. Thus, glutamine supplementation may enhance immunocompetence after strenuous exercise. The potential of glutamine supplementation during physical inactivity needs to be explored.

  13. Predictive modelling of (palaeo-)subglacial lake locations and their meltwater drainage routeways

    Science.gov (United States)

    Livingstone, S. J.; Clark, C.; Tarasoff, L.; Woodward, J.

    2013-12-01

    There is increasing recognition that subglacial lakes act as key components within the ice sheet system, capable of influencing ice-sheet topography, ice volume and ice flow. At present, much glaciological research is concerned with the role of modern subglacial lake systems in Antarctica. Another approach to the exploration of subglacial lakes involves identification of the geological record of subglacial lakes that once existed beneath ice sheets of the last glaciation. Investigation of such palaeo-subglacial lakes offers significant advantages because we have comprehensive information about the bed properties, they are much more accessible and we can examine and sample the sediments with ease. However, their identification in the geological record remains controversial. We therefore present a simple diagnostic approach based on the Shreve equation, for predicting and investigating likely (palaeo-)subglacial lake locations. Data on the current topography and seafloor bathymetry, and elevation models of the ice and ground surface topography from data-calibrated glaciological modelling are used to calculate the hydraulic potential surface at the ice-sheet bed. Meltwater routing algorithms and the flooding of local hydraulic minima allow us to predict subglacial routeways and lakes respectively. Discovered subglacial lakes beneath the Antarctic Ice Sheet present an opportunity to verify the model using the BEDMAP2 dataset. Using a lake threshold of 5 km2 we identify 12,767 subglacial lakes occurring over 4% of the grounded bed and are able to recover >60% of the discovered subglacial lakes. Applying the same approach to the Greenland Ice Sheet produces 1,607 potential subglacial lakes, covering 1.3% of the bed. These lake localities will make suitable targets for radar surveys attempting to find subglacial lakes. Finally, we apply the Shreve equation to the North American Ice Sheet to try and predict likely palaeo-subglacial lake locations. Given that specific ice

  14. STAT3 Activities and Energy Metabolism: Dangerous Liaisons

    Energy Technology Data Exchange (ETDEWEB)

    Camporeale, Annalisa, E-mail: annalisa.camporeale@unito.it [Molecular Biotechnology Center and Department of Molecular Biotechnology and Life Sciences, University of Turin, Via Nizza 52, Turin 10126 (Italy); Demaria, Marco [Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA 94945 (United States); Monteleone, Emanuele [Molecular Biotechnology Center and Department of Molecular Biotechnology and Life Sciences, University of Turin, Via Nizza 52, Turin 10126 (Italy); Giorgi, Carlotta [Department of Experimental and Diagnostic Medicine, Section of General Pathology, Laboratory for Technologies of Advances Therapies (LTTA), University of Ferrara, Via Fossato di Mortara 70, Ferrara 44121 (Italy); Wieckowski, Mariusz R. [Nencki Institute of Experimental Biology, Department of Biochemistry, Pasteur Str. 3, Warsaw 02-093 (Poland); Pinton, Paolo [Department of Experimental and Diagnostic Medicine, Section of General Pathology, Laboratory for Technologies of Advances Therapies (LTTA), University of Ferrara, Via Fossato di Mortara 70, Ferrara 44121 (Italy); Poli, Valeria, E-mail: annalisa.camporeale@unito.it [Molecular Biotechnology Center and Department of Molecular Biotechnology and Life Sciences, University of Turin, Via Nizza 52, Turin 10126 (Italy)

    2014-07-31

    STAT3 mediates cytokine and growth factor receptor signalling, becoming transcriptionally active upon tyrosine 705 phosphorylation (Y-P). Constitutively Y-P STAT3 is observed in many tumors that become addicted to its activity, and STAT3 transcriptional activation is required for tumor transformation downstream of several oncogenes. We have recently demonstrated that constitutively active STAT3 drives a metabolic switch towards aerobic glycolysis through the transcriptional induction of Hif-1α and the down-regulation of mitochondrial activity, in both MEF cells expressing constitutively active STAT3 (Stat3{sup C/C}) and STAT3-addicted tumor cells. This novel metabolic function is likely involved in mediating pre-oncogenic features in the primary Stat3{sup C/C} MEFs such as resistance to apoptosis and senescence and rapid proliferation. Moreover, it strongly contributes to the ability of primary Stat3{sup C/C} MEFs to undergo malignant transformation upon spontaneous immortalization, a feature that may explain the well known causative link between STAT3 constitutive activity and tumor transformation under chronic inflammatory conditions. Taken together with the recently uncovered role of STAT3 in regulating energy metabolism from within the mitochondrion when phosphorylated on Ser 727, these data place STAT3 at the center of a hub regulating energy metabolism under different conditions, in most cases promoting cell survival, proliferation and malignant transformation even though with distinct mechanisms.

  15. Mammary remodelling and metabolic activity in dairy goats

    DEFF Research Database (Denmark)

    Safayi, Sina

    of epithelial cell proliferation and apoptosis; 2) the secretory activity of these cells, which in turn is affected by their differentiation; and 3) the provision of nutrients and removal of metabolic waste products via the blood. The present thesis aimed to address the hypotheses that 1) differences between PP...... is affected by the balance between the rate of epithelial cell proliferation and apoptosis; 2) the secretory activity of these cells, which in turn is affected by their differentiation; and 3) the provision of nutrients and removal of metabolic waste products via the blood. The present thesis aimed to address......, acetate or glucose) and determining the impact on milk yield and mammary nutrient uptake. The necessarily more metabolically active. The explanation why milk yield in dairy goats is relatively unaffected by CL (in contrast to dairy cows) remains to be established. In conclusion, mammary development...

  16. Peroxisome Proliferator–Activated Receptors and The Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Anna Meiliana

    2009-04-01

    Full Text Available BACKGROUND: Obesity is a growing threat to global health by virtue of its association with insulin resistance, inflammation, hypertension, and dyslipidemia, collectively known as the metabolic syndrome (MetS. The nuclear receptors PPARα and PPARγ are therapeutic targets for hypertriglyceridemia and insulin resistance, respectively, and drugs that modulate these receptors are currently in clinical use. More recent work on the PPARδ has uncovered a dual benefit for both hypertriglyceridemia and insulin resistance, highlighting the broad potential of PPARs in the treatment of metabolic disease. CONTENT: We have learned much about PPARs, the metabolic fat sensors, and the molecular pathways they regulate. Through their distinct tissue distribution and specific target gene activation, the three PPARs together control diverse aspects of fatty acid metabolism, energy balance, insulin sensitivity glucose homeostasis, inflammation, hypertension and atherosclerosis. These studies have advanced our understanding of the etiology for the MetS. Mechanisms revealed by these studies highlight the importance of emerging concepts, such as the endocrine function of adipose tissue, tissue-tissue cross-talk and lipotoxicity, in the pathogenesis of type 2 diabetes mellitus and CVD. SUMMARY: The elucidation of key regulators of energy balance and insulin signaling have revolutionized our understanding of fat and sugar metabolism and their intimate link. The three ‘lipidsensing’ (PPARα, PPARγ and PPARδ exemplify this connection, regulating diverse aspects of lipid and glucose homeostasis, and serving as bonafide therapeutic targets. KEYWORDS: peroxisome proliferator, activated receptor, metabolic syndrome.

  17. Microbial life in ice and subglacial environments

    Science.gov (United States)

    Price, P. B.; Bramall, N.; Tatebe, K.

    2003-04-01

    Conditions for microbial life to exist in solid ice require the presence of liquid water and sources of energy and bioelements. In ice in thermal equilibrium, liquid water will exist in a three-dimensional network of micron-sized veins and in nanometer-thick films on mineral grains in ice. Ionic impurities lower the freezing temperature in the veins to as low as -95^oC. Depending on mineral type, the film on a grain surface will remain liquid down to ˜ -40^oC. The impurities provide both energy (via microbially catalyzed redox reactions) and bioelements. The maximum sustainable microbial population depends on metabolic rate, which in turn depends on species, temperature, and type and concentration of impurities in veins and surfaces. Microbes have been imaged by epifluorescence in veins in sea and Arctic lake ice and on grains in Dry Valleys lake ice. Indirect evidence exists for metabolism of microbes in Vostok glacial ice, in Greenland basal ice, and in Sajama (Bolivia) glacial ice. We will discuss several approaches to detection of microbes: epifluorescence microscopy of glacial ice at low temperature; fluorescence spectra taken with BSL (a new borehole logging instrument); fluorescence of microbes on surfaces of silt and volcanic ash in glacial ice; and in-situ cultivation of bacterial colonies at intersections of mineral grains and liquid veins in ice held in contact with a nutrient medium at subfreezing temperature. Based on measurements in the oligotrophic Lake Tahoe, BSL is sensitive to a concentration of ˜10^3 microbes cm-3, which may be adequate to detect life in Greenland ice and in Lake Vostok. A miniaturized version could be used to search for life in Martian permafrost and in diapirs in Europan ice.

  18. Natural Killer Cell Activity and Interleukin-12 in Metabolically Healthy versus Metabolically Unhealthy Overweight Individuals

    Directory of Open Access Journals (Sweden)

    Minjoo Kim

    2017-11-01

    Full Text Available The purpose of this study was to determine whether the immune system is involved in the different metabolic circumstances in healthy and unhealthy overweight individuals. We examined the metabolic and immune characteristics of 117 overweight individuals. Subjects were classified as metabolically healthy overweight (MHO, n = 72 or metabolically unhealthy overweight (MUO, n = 45. The immune response was measured by circulating levels of natural killer (NK cell activity and cytokines. Both groups were comparable with regards to age, sex distribution, smoking and drinking status, and body mass index. When compared to the MHO group, the MUO group showed higher systolic and diastolic blood pressure, serum levels of triglyceride, glucose, glucose-related markers, and lower levels of HDL cholesterol. Compared to the MHO group, the MUO group showed 39% lower interferon-γ levels (not significant and 41% lower interleukin (IL-12 levels (significant. The MUO group also showed lower NK cell activity at E:T ratios of 10:1, 5:1, 2.5:1, and 1.25:1 (all Ps < 0.05 than the MHO group. This study indicates that individuals displaying the MUO phenotype present an unfavorable immune system with lower NK cell activities under all assay conditions and lower serum levels of IL-12 than the activities and levels in similarly overweight MHO individuals. This result suggests that the immune system may be altered in overweight individuals who are at risk for overweight/obesity-related comorbidities.

  19. Effects of activation of endocannabinoid system on myocardial metabolism

    Directory of Open Access Journals (Sweden)

    Agnieszka Polak

    2016-05-01

    Full Text Available Endocannabinoids exert their effect on the regulation of energy homeostasis via activation of specific receptors. They control food intake, secretion of insulin, lipids and glucose metabolism, lipid storage. Long chain fatty acids are the main myocardial energy substrate. However, the heart exerts enormous metabolic flexibility emphasized by its ability to utilzation not only fatty acids, but also glucose, lactate and ketone bodies. Endocannabinoids can directly act on the cardiomyocytes through the CB1 and CB2 receptors present in cardiomyocytes. It appears that direct activation of CB1 receptors promotes increased lipogenesis, pericardial steatosis and bioelectrical dysfunction of the heart. In contrast, stimulation of CB2 receptors exhibits cardioprotective properties, helping to maintain appropriate amount of ATP in cardiomyocytes. Furthermore, the effects of endocannabinoids at both the central nervous system and peripheral tissues, such as liver, pancreas, or adipose tissue, resulting indirectly in plasma availability of energy substrates and affects myocardial metabolism. To date, there is little evidence that describes effects of activation of the endocannabinoid system in the cardiovascular system under physiological conditions. In the present paper the impact of metabolic diseases, i. e. obesity and diabetes, as well as the cardiovascular diseases - hypertension, myocardial ischemia and myocardial infarction on the deregulation of the endocannabinoid system and its effect on the metabolism are described.

  20. Copper oxide nanoparticles inhibit the metabolic activity of Saccharomyces cerevisiae.

    Science.gov (United States)

    Mashock, Michael J; Kappell, Anthony D; Hallaj, Nadia; Hristova, Krassimira R

    2016-01-01

    Copper oxide nanoparticles (CuO NPs) are used increasingly in industrial applications and consumer products and thus may pose risk to human and environmental health. The interaction of CuO NPs with complex media and the impact on cell metabolism when exposed to sublethal concentrations are largely unknown. In the present study, the short-term effects of 2 different sized manufactured CuO NPs on metabolic activity of Saccharomyces cerevisiae were studied. The role of released Cu(2+) during dissolution of NPs in the growth media and the CuO nanostructure were considered. Characterization showed that the 28 nm and 64 nm CuO NPs used in the present study have different primary diameter, similar hydrodynamic diameter, and significantly different concentrations of dissolved Cu(2+) ions in the growth media released from the same initial NP mass. Exposures to CuO NPs or the released Cu(2+) fraction, at doses that do not have impact on cell viability, showed significant inhibition on S. cerevisiae cellular metabolic activity. A greater CuO NP effect on the metabolic activity of S. cerevisiae growth under respiring conditions was observed. Under the tested conditions the observed metabolic inhibition from the NPs was not explained fully by the released Cu ions from the dissolving NPs. © 2015 SETAC.

  1. Structure, morphology and water flux of a subglacial drainage system, Midtdalsbreen, Norway

    NARCIS (Netherlands)

    Willis, I.C.; Fitzsimmons, C.D.; Melvold, K.; Andreassen, L.M.; Giesen, R.H.|info:eu-repo/dai/nl/304831603

    2012-01-01

    Digital elevation models of the surface and bed of Midtdalsbreen, Norway are used to calculate subglacial hydraulic potential and infer drainage system structure for a series of subglacial water pressure assumptions ranging from atmospheric to ice overburden. A distributed degree-day model is used

  2. Physical activity for the prevention and treatment of metabolic disorders.

    Science.gov (United States)

    Montesi, Luca; Moscatiello, Simona; Malavolti, Marcella; Marzocchi, Rebecca; Marchesini, Giulio

    2013-12-01

    Metabolic syndrome and its various features (obesity, hypertension, dyslipidemia, diabetes, and nonalcoholic fatty liver disease) are increasing worldwide and constitute a severe risk for the sustainability of the present universal Italian health care system. Lifestyle interventions should be the first therapeutic strategy to prevent/treat metabolic diseases, far before pharmacologic treatment. The role of diet and weight loss has been fully ascertained, whereas the role of physical activity is frequently overlooked both by physicians and by patients. Physical activity has favorable effects on all components of the metabolic syndrome and on the resulting cardiovascular risk, the cornerstone in the development of cardiometabolic diseases. The quantity and the frequency of physical activity necessary to produce beneficial effects has not been defined as yet, but brisk walking is considered particularly appropriate, as it can be practiced by a large number of individuals, without any additional cost, and has a low rate of injury. The effects of exercise and leisure time physical activity extend from prevention to treatment of the various components of the metabolic syndrome, as well as to mood and quality of life. Any effort should be done to favor adherence to protocols of physical activity in the community.

  3. Molecular Evidence for Metabolically Active Bacteria in the Atmosphere.

    Science.gov (United States)

    Klein, Ann M; Bohannan, Brendan J M; Jaffe, Daniel A; Levin, David A; Green, Jessica L

    2016-01-01

    Bacterial metabolisms are responsible for critical chemical transformations in nearly all environments, including oceans, freshwater, and soil. Despite the ubiquity of bacteria in the atmosphere, little is known about the metabolic functioning of atmospheric bacterial communities. To gain a better understanding of the metabolism of bacterial communities in the atmosphere, we used a combined empirical and model-based approach to investigate the structure and composition of potentially active bacterial communities in air sampled at a high elevation research station. We found that the composition of the putatively active bacterial community (assayed via rRNA) differed significantly from the total bacterial community (assayed via rDNA). Rare taxa in the total (rDNA) community were disproportionately active relative to abundant taxa, and members of the order Rhodospirillales had the highest potential for activity. We developed theory to explore the effects of random sampling from the rRNA and rDNA communities on observed differences between the communities. We found that random sampling, particularly in cases where active taxa are rare in the rDNA community, will give rise to observed differences in community composition including the occurrence of "phantom taxa", taxa which are detected in the rRNA community but not the rDNA community. We show that the use of comparative rRNA/rDNA techniques can reveal the structure and composition of the metabolically active portion of bacterial communities. Our observations suggest that metabolically active bacteria exist in the atmosphere and that these communities may be involved in the cycling of organic compounds in the atmosphere.

  4. Subglacial Lake Vostok (Antarctica accretion ice contains a diverse set of sequences from aquatic, marine and sediment-inhabiting bacteria and eukarya.

    Directory of Open Access Journals (Sweden)

    Yury M Shtarkman

    Full Text Available Lake Vostok, the 7(th largest (by volume and 4(th deepest lake on Earth, is covered by more than 3,700 m of ice, making it the largest subglacial lake known. The combination of cold, heat (from possible hydrothermal activity, pressure (from the overriding glacier, limited nutrients and complete darkness presents extreme challenges to life. Here, we report metagenomic/metatranscriptomic sequence analyses from four accretion ice sections from the Vostok 5G ice core. Two sections accreted in the vicinity of an embayment on the southwestern end of the lake, and the other two represented part of the southern main basin. We obtained 3,507 unique gene sequences from concentrates of 500 ml of 0.22 µm-filtered accretion ice meltwater. Taxonomic classifications (to genus and/or species were possible for 1,623 of the sequences. Species determinations in combination with mRNA gene sequence results allowed deduction of the metabolic pathways represented in the accretion ice and, by extension, in the lake. Approximately 94% of the sequences were from Bacteria and 6% were from Eukarya. Only two sequences were from Archaea. In general, the taxa were similar to organisms previously described from lakes, brackish water, marine environments, soil, glaciers, ice, lake sediments, deep-sea sediments, deep-sea thermal vents, animals and plants. Sequences from aerobic, anaerobic, psychrophilic, thermophilic, halophilic, alkaliphilic, acidophilic, desiccation-resistant, autotrophic and heterotrophic organisms were present, including a number from multicellular eukaryotes.

  5. The prevalence of metabolic syndrome among active sportsmen ...

    African Journals Online (AJOL)

    This study sought to establish the prevalence of the metabolic syndrome (MetS) among active sportsmen/sportswomen and sedentary workers in the Kumasi Metropolis using the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III), World Health Organization (WHO), and International Diabetes ...

  6. Basal metabolic regulatory responses and rhythmic activity of ...

    African Journals Online (AJOL)

    hope&shola

    2006-03-01

    Mar 1, 2006 ... activity of mammalian heart to aqueous kola nut extracts. Chukwu, L.O*, Odiete ... nut extract stimulated the heart by increasing rate and force of contraction as well as metabolic rate. Higher concentrations reduced rate .... contracture in frog striated muscle (Huxley and Taylor,. 1958). The xanthines stimulate ...

  7. Measurement of Metabolic Activity in Dormant Spores of Bacillus Species

    Science.gov (United States)

    2015-01-14

    SECURITY CLASSIFICATION OF: Spores of Bacillus megaterium and Bacillus subtilis were harvested shortly after release from sporangia, incubated under... SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6. AUTHORS 7. PERFORMING ORGANIZATION NAMES AND ADDRESSES 15. SUBJECT TERMS b...Dec-2014 Approved for Public Release; Distribution Unlimited Final Report: Measurement of Metabolic Activity in Dormant Spores of Bacillus Species

  8. Metabolic, autophagic, and mitophagic activities in cancer initiation and progression

    Directory of Open Access Journals (Sweden)

    Anita Hjelmeland

    2016-04-01

    Full Text Available Cancer is a complex disease marked by uncontrolled cell growth and invasion. These processes are driven by the accumulation of genetic and epigenetic alterations that promote cancer initiation and progression. Contributing to genome changes are the regulation of oxidative stress and reactive species-induced damage to molecules and organelles. Redox regulation, metabolic plasticity, autophagy, and mitophagy play important and interactive roles in cancer hallmarks including sustained proliferation, activated invasion, and replicative immortality. However, the impact of these processes can differ depending on the signaling pathways altered in cancer, tumor type, tumor stage, and/or the differentiation state. Here, we highlight some of the representative studies on the impact of oxidative and nitrosative activities, mitochondrial bioenergetics, metabolism, and autophagy and mitophagy in the context of tumorigenesis. We discuss the implications of these processes for cellular activities in cancer for anti-cancer-based therapeutics.

  9. Novel TPP-riboswitch activators bypass metabolic enzyme dependency.

    Science.gov (United States)

    Lünse, Christina E; Scott, Fraser J; Suckling, Colin J; Mayer, Günter

    2014-01-01

    Riboswitches are conserved regions within mRNA molecules that bind specific metabolites and regulate gene expression. TPP-riboswitches, which respond to thiamine pyrophosphate (TPP), are involved in the regulation of thiamine metabolism in numerous bacteria. As these regulatory RNAs are often modulating essential biosynthesis pathways they have become increasingly interesting as promising antibacterial targets. Here, we describe thiamine analogs containing a central 1,2,3-triazole group to induce repression of thiM-riboswitch dependent gene expression in different E. coli strains. Additionally, we show that compound activation is dependent on proteins involved in the metabolic pathways of thiamine uptake and synthesis. The most promising molecule, triazolethiamine (TT), shows concentration dependent reporter gene repression that is dependent on the presence of thiamine kinase ThiK, whereas the effect of pyrithiamine (PT), a known TPP-riboswitch modulator, is ThiK independent. We further show that this dependence can be bypassed by triazolethiamine-derivatives that bear phosphate-mimicking moieties. As triazolethiamine reveals superior activity compared to pyrithiamine, it represents a very promising starting point for developing novel antibacterial compounds that target TPP-riboswitches. Riboswitch-targeting compounds engage diverse endogenous mechanisms to attain in vivo activity. These findings are of importance for the understanding of compounds that require metabolic activation to achieve effective riboswitch modulation and they enable the design of novel compound generations that are independent of endogenous activation mechanisms.

  10. Direct observations of evolving subglacial drainage beneath the Greenland Ice Sheet.

    Science.gov (United States)

    Andrews, Lauren C; Catania, Ginny A; Hoffman, Matthew J; Gulley, Jason D; Lüthi, Martin P; Ryser, Claudia; Hawley, Robert L; Neumann, Thomas A

    2014-10-02

    Seasonal acceleration of the Greenland Ice Sheet is influenced by the dynamic response of the subglacial hydrologic system to variability in meltwater delivery to the bed via crevasses and moulins (vertical conduits connecting supraglacial water to the bed of the ice sheet). As the melt season progresses, the subglacial hydrologic system drains supraglacial meltwater more efficiently, decreasing basal water pressure and moderating the ice velocity response to surface melting. However, limited direct observations of subglacial water pressure mean that the spatiotemporal evolution of the subglacial hydrologic system remains poorly understood. Here we show that ice velocity is well correlated with moulin hydraulic head but is out of phase with that of nearby (0.3-2 kilometres away) boreholes, indicating that moulins connect to an efficient, channelized component of the subglacial hydrologic system, which exerts the primary control on diurnal and multi-day changes in ice velocity. Our simultaneous measurements of moulin and borehole hydraulic head and ice velocity in the Paakitsoq region of western Greenland show that decreasing trends in ice velocity during the latter part of the melt season cannot be explained by changes in the ability of moulin-connected channels to convey supraglacial melt. Instead, these observations suggest that decreasing late-season ice velocity may be caused by changes in connectivity in unchannelized regions of the subglacial hydrologic system. Understanding this spatiotemporal variability in subglacial pressures is increasingly important because melt-season dynamics affect ice velocity beyond the conclusion of the melt season.

  11. Calculating the balance between atmospheric CO2 drawdown and organic carbon oxidation in subglacial hydrochemical systems

    Science.gov (United States)

    Graly, Joseph A.; Drever, James I.; Humphrey, Neil F.

    2017-04-01

    In order to constrain CO2 fluxes from biogeochemical processes in subglacial environments, we model the evolution of pH and alkalinity over a range of subglacial weathering conditions. We show that subglacial waters reach or exceed atmospheric pCO2 levels when atmospheric gases are able to partially access the subglacial environment. Subsequently, closed system oxidation of sulfides is capable of producing pCO2 levels well in excess of atmosphere levels without any input from the decay of organic matter. We compared this model to published pH and alkalinity measurements from 21 glaciers and ice sheets. Most subglacial waters are near atmospheric pCO2 values. The assumption of an initial period of open system weathering requires substantial organic carbon oxidation in only 4 of the 21 analyzed ice bodies. If the subglacial environment is assumed to be closed from any input of atmospheric gas, large organic carbon inputs are required in nearly all cases. These closed system assumptions imply that order of 10 g m-2 y-1 of organic carbon are removed from a typical subglacial environment—a rate too high to represent soil carbon built up over previous interglacial periods and far in excess of fluxes of surface deposited organic carbon. Partial open system input of atmospheric gases is therefore likely in most subglacial environments. The decay of organic carbon is still important to subglacial inorganic chemistry where substantial reserves of ancient organic carbon are found in bedrock. In glaciers and ice sheets on silicate bedrock, substantial long-term drawdown of atmospheric CO2 occurs.

  12. Marine Omega-3 Phospholipids: Metabolism and Biological Activities

    Directory of Open Access Journals (Sweden)

    Nils Hoem

    2012-11-01

    Full Text Available The biological activities of omega-3 fatty acids (n-3 FAs have been under extensive study for several decades. However, not much attention has been paid to differences of dietary forms, such as triglycerides (TGs versus ethyl esters or phospholipids (PLs. New innovative marine raw materials, like krill and fish by-products, present n-3 FAs mainly in the PL form. With their increasing availability, new evidence has emerged on n-3 PL biological activities and differences to n-3 TGs. In this review, we describe the recently discovered nutritional properties of n-3 PLs on different parameters of metabolic syndrome and highlight their different metabolic bioavailability in comparison to other dietary forms of n-3 FAs.

  13. Metabolic syndrome and cognitive decline: the role of physical activity

    Directory of Open Access Journals (Sweden)

    M. Rinaldi

    2013-01-01

    Full Text Available Metabolic Syndrome (MetS is a cluster of conditions, each of which represents a risk factor for cardiovascular disease: central obesity, hyperglycemia, dyslipidemia and hypertension. Any of these conditions and MetS itself have been associated to Alzheimer's Disease and Vascular Dementia. In recent years there is a growing evidence for the role of physical activity in preventing metabolic diseases and cognitive decline. In our research we assessed the prevalence of MetS in a sample of 154 elderly people. Furthermore, we evaluated cognition (with Mini Mental State Examination, MMSE  and the physical activity level in every patient. We found a significant association between MetS, borderline cognitive impairment and sedentary lifestyle.

  14. Sleep slow-wave activity regulates cerebral glycolytic metabolism.

    Science.gov (United States)

    Wisor, Jonathan P; Rempe, Michael J; Schmidt, Michelle A; Moore, Michele E; Clegern, William C

    2013-08-01

    Non-rapid eye movement sleep (NREMS) onset is characterized by a reduction in cerebral metabolism and an increase in slow waves, 1-4-Hz oscillations between relatively depolarized and hyperpolarized states in the cerebral cortex. The metabolic consequences of slow-wave activity (SWA) at the cellular level remain uncertain. We sought to determine whether SWA modulates the rate of glycolysis within the cerebral cortex. The real-time measurement of lactate concentration in the mouse cerebral cortex demonstrates that it increases during enforced wakefulness. In spontaneous sleep/wake cycles, lactate concentration builds during wakefulness and rapid eye movement sleep and declines during NREMS. The rate at which lactate concentration declines during NREMS is proportional to the magnitude of electroencephalographic (EEG) activity at frequencies of cerebral SWA promotes a decline in the rate of glycolysis in the cerebral cortex. These results demonstrate a cellular energetic function for sleep SWA, which may contribute to its restorative effects on brain function.

  15. Fibroblast activation protein (FAP) as a novel metabolic target

    DEFF Research Database (Denmark)

    Sánchez-Garrido, Miguel Angel; Habegger, Kirk M; Clemmensen, Christoffer

    2016-01-01

    to block FAP enzymatic activity. RESULTS: TB administration to diet-induced obese (DIO) animals led to profound decreases in body weight, reduced food consumption and adiposity, increased energy expenditure, improved glucose tolerance and insulin sensitivity, and lowered cholesterol levels. Total...... on body weight or any other measures of metabolism. In support of these results we observed no enzymatic degradation of human FGF21 at either end of the protein when FAP was inhibited in vitro by TB. CONCLUSIONS: We conclude that pharmacological inhibition of FAP enhances levels of FGF21 in obese mice......OBJECTIVE: Fibroblast activation protein (FAP) is a serine protease belonging to a S9B prolyl oligopeptidase subfamily. This enzyme has been implicated in cancer development and recently reported to regulate degradation of FGF21, a potent metabolic hormone. Using a known FAP inhibitor, talabostat...

  16. Activating and Elucidating Metabolism of Complex Sugars in Yarrowia lipolytica.

    Science.gov (United States)

    Ryu, Seunghyun; Hipp, Julie; Trinh, Cong T

    2015-12-18

    The oleaginous yeast Yarrowia lipolytica is an industrially important host for production of organic acids, oleochemicals, lipids, and proteins with broad biotechnological applications. Albeit known for decades, the unique native metabolism of Y. lipolytica for using complex fermentable sugars, which are abundant in lignocellulosic biomass, is poorly understood. In this study, we activated and elucidated the native sugar metabolism in Y. lipolytica for cell growth on xylose and cellobiose as well as their mixtures with glucose through comprehensive metabolic and transcriptomic analyses. We identified 7 putative glucose-specific transporters, 16 putative xylose-specific transporters, and 4 putative cellobiose-specific transporters that are transcriptionally upregulated for growth on respective single sugars. Y. lipolytica is capable of using xylose as a carbon source, but xylose dehydrogenase is the key bottleneck of xylose assimilation and is transcriptionally repressed by glucose. Y. lipolytica has a set of 5 extracellular and 6 intracellular β-glucosidases and is capable of assimilating cellobiose via extra- and intracellular mechanisms, the latter being dominant for growth on cellobiose as a sole carbon source. Strikingly, Y. lipolytica exhibited enhanced sugar utilization for growth in mixed sugars, with strong carbon catabolite activation for growth on the mixture of xylose and cellobiose and with mild carbon catabolite repression of glucose on xylose and cellobiose. The results of this study shed light on fundamental understanding of the complex native sugar metabolism of Y. lipolytica and will help guide inverse metabolic engineering of Y. lipolytica for enhanced conversion of biomass-derived fermentable sugars to chemicals and fuels. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. Physical activity, fitness, and metabolic syndrome in young adults.

    Science.gov (United States)

    López-Martínez, Sara; Sánchez-López, Mairena; Solera-Martinez, Montserrat; Arias-Palencia, Natalia; Fuentes-Chacón, Rosa M; Martínez-Vizcaíno, Vicente

    2013-08-01

    Our objective was to analyze the association between different intensities of physical activity (PA), physical fitness, and metabolic syndrome (MS) in young adults. Cross-sectional study including 275 university students, 18-30 years old, from Cuenca, Spain. We evaluated (a) physical activity using accelerometry, (b) aerobic capacity (VO2max), and (c) muscle strength, by a muscle strength index calculated as the sum of the standardized z score of handgrip dynamometry/weight and standing broad jump. An MS index was estimated by summing standardized z scores of waist circumference, ratio of triglycerides to high-density lipoprotein, mean arterial blood pressure, and HOMA-IR. The mean scores of MS index and HOMAIR were significantly higher and the VO2max significantly lower for individuals who did not perform 20 min or more per week of vigorous physical activity. However, those who performed 250 min/week of moderate physical activity showed no significant differences in either VO2max or the MS index when compared with individuals who did not perform this level of activity. The MS index was lower in those with medium-high levels of aerobic capacity. In addition, individuals with medium-high levels of muscular fitness showed lower waist circumference and a lower MS index. VO2max and muscle strength are negatively associated with metabolic risk. 20-min/week of vigorous physical activity was associated with lower cardiometabolic risk in young adults; moderate physical activity did not show association with lower cardiometabolic risk.

  18. Inhibitors of testosterone biosynthetic and metabolic activation enzymes.

    Science.gov (United States)

    Ye, Leping; Su, Zhi-Jian; Ge, Ren-Shan

    2011-12-02

    The Leydig cells of the testis have the capacity to biosynthesize testosterone from cholesterol. Testosterone and its metabolically activated product dihydrotestosterone are critical for the development of male reproductive system and spermatogenesis. At least four steroidogenic enzymes are involved in testosterone biosynthesis: Cholesterol side chain cleavage enzyme (CYP11A1) for the conversion of cholesterol into pregnenolone within the mitochondria, 3β-hydroxysteroid dehydrogenase (HSD3B), for the conversion of pregnenolone into progesterone, 17α-hydroxylase/17,20-lyase (CYP17A1) for the conversion of progesterone into androstenedione and 17β-hydroxysteroid dehydrogenase (HSD17B3) for the formation of testosterone from androstenedione. Testosterone is also metabolically activated into more potent androgen dihydrotestosterone by two isoforms 5α-reductase 1 (SRD5A1) and 2 (SRD5A2) in Leydig cells and peripheral tissues. Many endocrine disruptors act as antiandrogens via directly inhibiting one or more enzymes for testosterone biosynthesis and metabolic activation. These chemicals include industrial materials (perfluoroalkyl compounds, phthalates, bisphenol A and benzophenone) and pesticides/biocides (methoxychlor, organotins, 1,2-dibromo-3-chloropropane and prochloraz) and plant constituents (genistein and gossypol). This paper reviews these endocrine disruptors targeting steroidogenic enzymes.

  19. Inhibitors of Testosterone Biosynthetic and Metabolic Activation Enzymes

    Directory of Open Access Journals (Sweden)

    Leping Ye

    2011-12-01

    Full Text Available The Leydig cells of the testis have the capacity to biosynthesize testosterone from cholesterol. Testosterone and its metabolically activated product dihydrotestosterone are critical for the development of male reproductive system and spermatogenesis. At least four steroidogenic enzymes are involved in testosterone biosynthesis: Cholesterol side chain cleavage enzyme (CYP11A1 for the conversion of cholesterol into pregnenolone within the mitochondria, 3β-hydroxysteroid dehydrogenase (HSD3B, for the conversion of pregnenolone into progesterone, 17α-hydroxylase/17,20-lyase (CYP17A1 for the conversion of progesterone into androstenedione and 17β-hydroxysteroid dehydrogenase (HSD17B3 for the formation of testosterone from androstenedione. Testosterone is also metabolically activated into more potent androgen dihydrotestosterone by two isoforms 5α-reductase 1 (SRD5A1 and 2 (SRD5A2 in Leydig cells and peripheral tissues. Many endocrine disruptors act as antiandrogens via directly inhibiting one or more enzymes for testosterone biosynthesis and metabolic activation. These chemicals include industrial materials (perfluoroalkyl compounds, phthalates, bisphenol A and benzophenone and pesticides/biocides (methoxychlor, organotins, 1,2-dibromo-3-chloropropane and prochloraz and plant constituents (genistein and gossypol. This paper reviews these endocrine disruptors targeting steroidogenic enzymes.

  20. Effects of vasoactive and metabolic active substances (measurement of RCBF)

    Energy Technology Data Exchange (ETDEWEB)

    Herrschaft, H.

    1986-09-29

    Methods, principles, normal values, reproducibility and clinical indications of rCBF-measurements, using the intraartrial 133-Xenon-clearance-technique, are presented. The effect of vaso- and metabolically active drugs on cerebral blood flow was examined in 215 patients, suffering from cerebral ischemia. Significant increase of rCBF was ascertained after intravenous injection of centrophenoxine, pyrithioxine, extractum sanguis deproteinatus, piracetam and solutions of low molecular dextran. All the other drugs tested proved to be either without any effect or caused decrease of rCBF. In 130 patients with obstructive disease of internal carotid artery after surgery at an interval of 6 - 8 weeks and 1 year a significant increase of CBF could be stated. The rank of psychological tests and quantitative EEF-investigations relating to evidence of efficacy of metabolically active drugs is discussed critically. Therapeutic efficacy and clinical relevance of vaso- and metabolically active drugs in cerebral ischemia of man are to be substantiated only by double-blind controlled studies.

  1. Physical activity, body composition and metabolic syndrome in young adults.

    Science.gov (United States)

    Salonen, Minna K; Wasenius, Niko; Kajantie, Eero; Lano, Aulikki; Lahti, Jari; Heinonen, Kati; Räikkönen, Katri; Eriksson, Johan G

    2015-01-01

    Low physical activity (PA) is a major risk factor for cardiovascular and metabolic disorders in all age groups. We measured intensity and volume of PA and examined the associations between PA and the metabolic syndrome (MS), its components and body composition among young Finnish adults. The study comprises 991 men and women born 1985-86, who participated in a clinical study during the years 2009-11 which included assessments of metabolism, body composition and PA. Objectively measured (SenseWear Armband) five-day PA data was available from 737 participants and was expressed in metabolic equivalents of task (MET). The prevalence of MS ranged between 8-10%. Higher total mean volume (MET-hours) or intensity (MET) were negatively associated with the risk of MS and separate components of MS, while the time spent at sedentary level of PA was positively associated with MS. MS was prevalent in approximately every tenth of the young adults at the age of 24 years. Higher total mean intensity and volume rates as well as longer duration spent at moderate and vigorous PA level had a beneficial impact on the risk of MS. Longer time spent at the sedentary level of PA increased the risk of MS.

  2. Physical activity, body composition and metabolic syndrome in young adults.

    Directory of Open Access Journals (Sweden)

    Minna K Salonen

    Full Text Available Low physical activity (PA is a major risk factor for cardiovascular and metabolic disorders in all age groups. We measured intensity and volume of PA and examined the associations between PA and the metabolic syndrome (MS, its components and body composition among young Finnish adults.The study comprises 991 men and women born 1985-86, who participated in a clinical study during the years 2009-11 which included assessments of metabolism, body composition and PA. Objectively measured (SenseWear Armband five-day PA data was available from 737 participants and was expressed in metabolic equivalents of task (MET.The prevalence of MS ranged between 8-10%. Higher total mean volume (MET-hours or intensity (MET were negatively associated with the risk of MS and separate components of MS, while the time spent at sedentary level of PA was positively associated with MS.MS was prevalent in approximately every tenth of the young adults at the age of 24 years. Higher total mean intensity and volume rates as well as longer duration spent at moderate and vigorous PA level had a beneficial impact on the risk of MS. Longer time spent at the sedentary level of PA increased the risk of MS.

  3. Activity syndromes and metabolism in giant deep-sea isopods

    Science.gov (United States)

    Wilson, Alexander D. M.; Szekeres, Petra; Violich, Mackellar; Gutowsky, Lee F. G.; Eliason, Erika J.; Cooke, Steven J.

    2017-03-01

    Despite growing interest, the behavioural ecology of deep-sea organisms is largely unknown. Much of this scarcity in knowledge can be attributed to deepwater animals being secretive or comparatively 'rare', as well as technical difficulties associated with accessing such remote habitats. Here we tested whether two species of giant marine isopod (Bathynomus giganteus, Booralana tricarinata) captured from 653 to 875 m in the Caribbean Sea near Eleuthera, The Bahamas, exhibited an activity behavioural syndrome across two environmental contexts (presence/absence of food stimulus) and further whether this syndrome carried over consistently between sexes. We also measured routine metabolic rate and oxygen consumption in response to a food stimulus in B. giganteus to assess whether these variables are related to individual differences in personality. We found that both species show an activity syndrome across environmental contexts, but the underlying mechanistic basis of this syndrome, particularly in B. giganteus, is unclear. Contrary to our initial predictions, neither B. giganteus nor B. tricarinata showed any differences between mean expression of behavioural traits between sexes. Both sexes of B. tricarinata showed strong evidence of an activity syndrome underlying movement and foraging ecology, whereas only male B. giganteus showed evidence of an activity syndrome. Generally, individuals that were more active and bolder, in a standard open arena test were also more active when a food stimulus was present. Interestingly, individual differences in metabolism were not related to individual differences in behaviour based on present data. Our study provides the first measurements of behavioural syndromes and metabolism in giant deep-sea isopods.

  4. Physical activity in prevention and treatment of the metabolic syndrome.

    Science.gov (United States)

    Lakka, Timo A; Laaksonen, David E

    2007-02-01

    Randomised controlled trials have shown that exercise training has a mild or moderate favourable effect on many metabolic and cardiovascular risk factors that constitute or are related to the metabolic syndrome (MetS). Epidemiological studies suggest that regular physical activity prevents type 2 diabetes, cardiovascular disease, and premature mortality in large part through these risk factors. Although randomized controlled trials with the prevention or treatment of the MetS as the main outcome have not been published, several large randomized controlled trials provide strong evidence that favourable lifestyle changes, including regular physical activity, are effective in the prevention of type 2 diabetes in individuals who are overweight and have impaired glucose tolerance. Compliance with the current recommendations to increase the total volume of moderate-intensity physical activity and to maintain good cardiorespiratory and muscular fitness appears to markedly decrease the likelihood of developing the MetS, especially in high-risk groups. Walking is the most common form of physical activity--it improves health in many ways and is generally safe. Therefore, brisk walking for at least 30 min daily can be recommended as the principal form of physical activity at the population level. If there are no contraindications, more vigorous physical exercise or resistance training should also be considered to obtain additional health benefits. Unstructured and low-intensity physical activity may also decrease the likelihood of developing the MetS, especially when substituted for sedentary behaviours such as watching television. The measurement of maximal oxygen consumption may provide an efficient means to target even individuals with relatively few metabolic risk factors who may benefit from more intensive intervention.

  5. Pre-Eclampsia Placental Carbohydrate Metabolism Regulating Enzymes Activity

    OpenAIRE

    Oré, Raquel; Centro de Investigación en Bioquímica y Nutrición, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú; Suárez, Silvia; Centro de Investigación en Bioquímica y Nutrición, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú; Arnao, Inés; Centro de Investigación en Bioquímica y Nutrición, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú

    2014-01-01

    Pre eclampsia is one of the most frecuent pathologies during pregnancy. The placental tissue plays an important role in the development of the pathology. In this report we performed a study of the activities of two regulatory enzymes [ Phosphofructokinase I (E.C. 2.7.1.11) and Glucose 6-P-dehidrogenase (E.C. 1.1.1.49)] of the carbohydrate metabolism in both normal and pre emclampsia placental tissue. It has been found a pronounced decreased in both activities in the pathological tissue. We di...

  6. MODELING OF WATER CIRCULATION IN THE ANTARCTIC SUBGLACIAL LAKE VOSTOK

    Directory of Open Access Journals (Sweden)

    G. V. Kazko

    2012-01-01

    Full Text Available Different ways of defining the characteristics of Antarctic subglacialLakeVostokcirculation are considered. The disadvantages of hydrodynamic models using the hydrostatic approximation exposed to analysis. Differential equations and boundary conditions of three-dimensional nonhydrostatic model in terms vorticity–vector potential, specially developed for the modelling of the lake circulation are presented. 3D model passed through the testing by means simulations of convective currents in the simple-form reservoirs. On the basis of the seismic data on the thickness of a glacier and bathimetry of the lake the computational domain approximating a water body ofLakeVostokis constructed. Some results of modeling of the convective processes in the lake, obtained at the initial stage of circulation evolution using finite-difference grid with a spatial resolution of 8000 × 1500 ×30 mare shown.

  7. Subglacial sediment mechanics investigated by computer simulation of granular material

    DEFF Research Database (Denmark)

    Damsgaard, Anders; Egholm, David Lundbek; Tulaczyk, Slawek

    to the mechanical nonlinearity of the sediment, internal porosity changes during deformation, and associated structural and kinematic phase transitions. In this presentation, we introduce the Discrete Element Method (DEM) for particle-scale granular simulation. The DEM is fully coupled with fluid dynamics....... The numerical method is applied to better understand the mechanical properties of the subglacial sediment and its interaction with meltwater. The computational approach allows full experimental control and offers insights into the internal kinematics, stress distribution, and mechanical stability. During...... by linear-viscous sediment movement. We demonstrate how channel flanks are stabilized by the sediment frictional strength. Additionally, sediment liquefaction proves to be a possible mechanism for causing large and episodic sediment transport by water flow. Though computationally intense, our coupled...

  8. Stress Redistribution Explains Anti-correlated Subglacial Pressure Variations

    Directory of Open Access Journals (Sweden)

    Pierre-Marie Lefeuvre

    2018-01-01

    Full Text Available We used a finite element model to interpret anti-correlated pressure variations at the base of a glacier to demonstrate the importance of stress redistribution in the basal ice. We first investigated two pairs of load cells installed 20 m apart at the base of the 210 m thick Engabreen glacier in Northern Norway. The load cell data for July 2003 showed that pressurisation of a subglacial channel located over one load cell pair led to anti-correlation in pressure between the two pairs. To investigate the cause of this anti-correlation, we used a full Stokes 3D model of a 210 m thick and 25–200 m wide glacier with a pressurised subglacial channel represented as a pressure boundary condition. The model reproduced the anti-correlated pressure response at the glacier bed and variations in pressure of the same order of magnitude as the load cell observations. The anti-correlation pattern was shown to depend on the bed/surface slope. On a flat bed with laterally constrained cross-section, the resulting bridging effect diverted some of the normal forces acting on the bed to the sides. The anti-correlated pressure variations were then reproduced at a distance >10–20 m from the channel. In contrast, when the bed was inclined, the channel support of the overlying ice was vertical only, causing a reduction of the normal stress on the bed. With a bed slope of 5 degrees, the anti-correlation occurred within 10 m of the channel. The model thus showed that the effect of stress redistribution can lead to an opposite response in pressure at the same distance from the channel and that anti-correlation in pressure is reproduced without invoking cavity expansion caused by sliding.

  9. Metabolic Plasticity in Resting and Thrombin Activated Platelets

    Science.gov (United States)

    Ravi, Saranya; Chacko, Balu; Sawada, Hirotaka; Kramer, Philip A.; Johnson, Michelle S.; Benavides, Gloria A.; O’Donnell, Valerie; Marques, Marisa B.; Darley-Usmar, Victor M.

    2015-01-01

    Platelet thrombus formation includes several integrated processes involving aggregation, secretion of granules, release of arachidonic acid and clot retraction, but it is not clear which metabolic fuels are required to support these events. We hypothesized that there is flexibility in the fuels that can be utilized to serve the energetic and metabolic needs for resting and thrombin-dependent platelet aggregation. Using platelets from healthy human donors, we found that there was a rapid thrombin-dependent increase in oxidative phosphorylation which required both glutamine and fatty acids but not glucose. Inhibition of fatty acid oxidation or glutamine utilization could be compensated for by increased glycolytic flux. No evidence for significant mitochondrial dysfunction was found, and ATP/ADP ratios were maintained following the addition of thrombin, indicating the presence of functional and active mitochondrial oxidative phosphorylation during the early stages of aggregation. Interestingly, inhibition of fatty acid oxidation and glutaminolysis alone or in combination is not sufficient to prevent platelet aggregation, due to compensation from glycolysis, whereas inhibitors of glycolysis inhibited aggregation approximately 50%. The combined effects of inhibitors of glycolysis and oxidative phosphorylation were synergistic in the inhibition of platelet aggregation. In summary, both glycolysis and oxidative phosphorylation contribute to platelet metabolism in the resting and activated state, with fatty acid oxidation and to a smaller extent glutaminolysis contributing to the increased energy demand. PMID:25875958

  10. Metabolic plasticity in resting and thrombin activated platelets.

    Directory of Open Access Journals (Sweden)

    Saranya Ravi

    Full Text Available Platelet thrombus formation includes several integrated processes involving aggregation, secretion of granules, release of arachidonic acid and clot retraction, but it is not clear which metabolic fuels are required to support these events. We hypothesized that there is flexibility in the fuels that can be utilized to serve the energetic and metabolic needs for resting and thrombin-dependent platelet aggregation. Using platelets from healthy human donors, we found that there was a rapid thrombin-dependent increase in oxidative phosphorylation which required both glutamine and fatty acids but not glucose. Inhibition of fatty acid oxidation or glutamine utilization could be compensated for by increased glycolytic flux. No evidence for significant mitochondrial dysfunction was found, and ATP/ADP ratios were maintained following the addition of thrombin, indicating the presence of functional and active mitochondrial oxidative phosphorylation during the early stages of aggregation. Interestingly, inhibition of fatty acid oxidation and glutaminolysis alone or in combination is not sufficient to prevent platelet aggregation, due to compensation from glycolysis, whereas inhibitors of glycolysis inhibited aggregation approximately 50%. The combined effects of inhibitors of glycolysis and oxidative phosphorylation were synergistic in the inhibition of platelet aggregation. In summary, both glycolysis and oxidative phosphorylation contribute to platelet metabolism in the resting and activated state, with fatty acid oxidation and to a smaller extent glutaminolysis contributing to the increased energy demand.

  11. Changes to coral health and metabolic activity under oxygen deprivation

    Directory of Open Access Journals (Sweden)

    James W.A. Murphy

    2016-04-01

    Full Text Available On Hawaiian reefs, the fast-growing, invasive algae Gracilaria salicornia overgrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2 < 2 mg/L occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. To analyze the impact of nighttime oxygen-deprivation on coral health, this study evaluated changes in coral metabolism through the exposure of corals to chronic hypoxic conditions and subsequent analyses of lactate, octopine, alanopine, and strombine dehydrogenase activities, critical enzymes employed through anaerobic respiration. Following treatments, lactate and octopine dehydrogenase activities were found to have no significant response in activities with treatment and time. However, corals subjected to chronic nighttime hypoxia were found to exhibit significant increases in alanopine dehydrogenase activity after three days of exposure and strombine dehydrogenase activity starting after one overnight exposure cycle. These findings provide new insights into coral metabolic shifts in extremely low-oxygen environments and point to ADH and SDH assays as tools for quantifying the impact of hypoxia on coral health.

  12. Greenland subglacial drainage evolution regulated by weakly connected regions of the bed.

    Science.gov (United States)

    Hoffman, Matthew J; Andrews, Lauren C; Price, Stephen A; Catania, Ginny A; Neumann, Thomas A; Lüthi, Martin P; Gulley, Jason; Ryser, Claudia; Hawley, Robert L; Morriss, Blaine

    2016-12-19

    Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage of water and lowering of water pressure in weakly connected regions of the bed can explain the dominant features in late and post melt season ice dynamics. These results suggest that a third weakly connected drainage component should be included in the conceptual model of subglacial hydrology.

  13. Subglacial water drainage, storage, and piracy beneath the Greenland ice sheet

    Science.gov (United States)

    Lindbäck, K.; Pettersson, R.; Hubbard, A. L.; Doyle, S. H.; As, D.; Mikkelsen, A. B.; Fitzpatrick, A. A.

    2015-09-01

    Meltwater drainage across the surface of the Greenland ice sheet (GrIS) is well constrained by measurements and modeling, yet despite its critical role, knowledge of its transit through the subglacial environment remains limited. Here we present a subglacial hydrological analysis of a land-terminating sector of the GrIS at unprecedented resolution that predicts the routing of surface-derived meltwater once it has entered the basal drainage system. Our analysis indicates the probable existence of small subglacial lakes that remain undetectable by methods using surface elevation change or radar techniques. Furthermore, the analysis suggests transient behavior with rapid switching of subglacial drainage between competing catchments driven by seasonal changes in the basal water pressure. Our findings provide a cautionary note that should be considered in studies that attempt to relate and infer future response from surface temperature, melt, and runoff from point measurements and/or modeling with measurements of proglacial discharge and ice dynamics.

  14. Predicting subglacial lakes and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets

    Science.gov (United States)

    Livingstone, S. J.; Clark, C. D.; Woodward, J.

    2013-03-01

    In this paper we use the Shreve hydraulic potential equation to predict subglacial lakes and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets. For the Antarctic Ice Sheet we are able to predict known subglacial lakes with a >70% success rate, which demonstrates the validity of this method. Despite the success in predicting known subglacial lakes the calculations produce two-orders of magnitude more lakes than are presently identified, covering 4% of the ice-sheet bed. The difference is thought to result from our poor knowledge of the bed (which has resulted in artefacts associated with the interpolation method), intrinsic errors associated with the simplified modelling approach and because thousands of subglacial lakes, particularly smaller ones, remain to be found. Applying the same modelling approach to the Greenland Ice Sheet predicts only 90 lakes under the present-day ice-sheet configuration, covering 0.2% of the bed. The paucity of subglacial lakes in Greenland is thought to be a function of steeper overall ice-surface gradients. As no lakes have currently been located under Greenland, model predictions will make suitable targets for radar surveys of Greenland to identify subglacial lakes. During deglaciation from the Last Glacial Maximum both ice sheets had more subglacial lakes at their beds, though many of these lakes have persisted to present conditions. These lakes, inherited from past ice-sheet configurations would not form under current surface conditions, suggesting a retreating ice-sheet will have many more subglacial lakes than an advancing ice sheet. This hysteresis effect has implications for ice-stream formation and flow, bed lubrication and meltwater drainage. The lake model also allows modelling of the drainage pathways of the present-day and former Greenland and Antarctic ice sheets. Significantly, key sectors of the ice sheets, such as the Siple Coast (Antarctica) and NE Greenland Ice Stream system, are shown to have

  15. Potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets

    Science.gov (United States)

    Livingstone, S. J.; Clark, C. D.; Woodward, J.; Kingslake, J.

    2013-11-01

    We use the Shreve hydraulic potential equation as a simplified approach to investigate potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets. We validate the method by demonstrating its ability to recall the locations of >60% of the known subglacial lakes beneath the Antarctic Ice Sheet. This is despite uncertainty in the ice-sheet bed elevation and our simplified modelling approach. However, we predict many more lakes than are observed. Hence we suggest that thousands of subglacial lakes remain to be found. Applying our technique to the Greenland Ice Sheet, where very few subglacial lakes have so far been observed, recalls 1607 potential lake locations, covering 1.2% of the bed. Our results will therefore provide suitable targets for geophysical surveys aimed at identifying lakes beneath Greenland. We also apply the technique to modelled past ice-sheet configurations and find that during deglaciation both ice sheets likely had more subglacial lakes at their beds. These lakes, inherited from past ice-sheet configurations, would not form under current surface conditions, but are able to persist, suggesting a retreating ice-sheet will have many more subglacial lakes than advancing ones. We also investigate subglacial drainage pathways of the present-day and former Greenland and Antarctic ice sheets. Key sectors of the ice sheets, such as the Siple Coast (Antarctica) and NE Greenland Ice Stream system, are suggested to have been susceptible to subglacial drainage switching. We discuss how our results impact our understanding of meltwater drainage, basal lubrication and ice-stream formation.

  16. Reconstruction of a Palaeo-Subglacial Lake Network in Alberta, Canada

    Science.gov (United States)

    Livingstone, S. J.; Utting, D.; Clark, C.; Ruffell, A.; Pawley, S. M.; Atkinson, N.; Mallon, G.

    2014-12-01

    Subglacial lakes have been widely documented since first being identified beneath the Antarctic Ice Sheet in the 1960s and comprise a significant component of the subglacial hydrological system (Wright & Siegert, 2011). However, their investigation is largely limited to contemporary ice masses despite critical information that could be gleaned from palaeo-subglacial lake studies, including: (i) their influence on meltwater drainage, ice flow and ice streams; (ii) details about how they relate to palaeo-floods, ice dynamics and sub-Milankovitch-scale climate events; and (iii) as archives of long-term Quaternary climate change. They are also readily available, we can sample the sediments and maps the landforms with ease and we have comprehensive information on the lake-bed properties. Output from numerical ice sheet models and the simple Shreve equation approach has been used to diagnose where subglacial lakes are likely to have occurred in the geological record (Livingstone et al. 2013). However, their identification remains controversial due to the difficulty in distinguishing their signature from proglacial lake deposits (see Livingstone et al. 2012). Here, we present new geomorphological, geophysical and sedimentological evidence for the existence of a palaeo-subglacial lake network beneath the suture zone of the former Cordilleran and Laurentide ice sheets. These relatively small (~1 km diameter) palaeo-subglacial lakes manifest as flat-spots in a drumlin field and are perched in upland areas behind small ridges. The flat-spots, which comprise basins in-filled with diamicton, are associated with subglacial meltwater channels and eskers that we interpret to document lake drainage events. References: Livingstone, S.J., et al., 2012. Quaternary Science Reviews,55, 88-110. Livingstone, S.J., et al., 2013. Earth and Planetary Science Letters, 375, 13-33. Wright A.P., Siegert M.J. 2011. In: Siegert, M.J., Kennicutt, C., Bindschadler, B. (Eds.). Subglacial Antarctic

  17. In vivo enzyme activity in inborn errors of metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, G.N.; Walter, J.H.; Leonard, J.V.; Halliday, D. (Clinical Research Centre, Harrow (England))

    1990-08-01

    Low-dose continuous infusions of (2H5)phenylalanine, (1-13C)propionate, and (1-13C)leucine were used to quantitate phenylalanine hydroxylation in phenylketonuria (PKU, four subjects), propionate oxidation in methylmalonic acidaemia (MMA, four subjects), and propionic acidaemia (PA, four subjects) and leucine oxidation in maple syrup urine disease (MSUD, four subjects). In vivo enzyme activity in PKU, MMA, and PA subjects was similar to or in excess of that in adult controls (range of phenylalanine hydroxylation in PKU, 3.7 to 6.5 mumol/kg/h, control 3.2 to 7.9, n = 7; propionate oxidation in MMA, 15.2 to 64.8 mumol/kg/h, and in PA, 11.1 to 36.0, control 5.1 to 19.0, n = 5). By contrast, in vivo leucine oxidation was undetectable in three of the four MSUD subjects (less than 0.5 mumol/kg/h) and negligible in the remaining subject (2 mumol/kg/h, control 10.4 to 15.7, n = 6). These results suggest that significant substrate removal can be achieved in some inborn metabolic errors either through stimulation of residual enzyme activity in defective enzyme systems or by activation of alternate metabolic pathways. Both possibilities almost certainly depend on gross elevation of substrate concentrations. By contrast, only minimal in vivo oxidation of leucine appears possible in MSUD.

  18. Metabolic Syndrome and Physical Activity in Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    derya atik

    2014-06-01

    Full Text Available Purpose: This descriptive study was carried out to reveal the level of physical activity in patients who receive hemodialysis due to chronic kidney failure and to identify its relationship with the prevalence of metabolic syndrome (MetS. Material and method: The study was conducted with 55 patients at the hemodialysis units of Alanya State Hospital and Private Alanya Anadolu Hospital between 10 and 30 June 2013. The study data were collected using the National Cholesterol Education Program, the Adult Treatment Panel III (NCEP-ATP III, a data collection form containing Metabolic Syndrome Diagnosis Criteria, and the International Physical Activity Questionnaire (IPAQ. The data were analyzed using arithmetic mean +/- standard deviation (SD, number and percentage distributions, independent sample t test, crosstabs, One Way Anova, and Pearson and #8217;s Correlation Analysis. Conclusion and suggestions: It was found that 41.8% of the patients were between 50 and 65 years of age, the majority of them were male (58.2%, hemodialysis had been administered to 69.1% of them for at least 36 months, and 50.9% of them met three and more of the MetS criteria. There was no statistically significant relationship between MetS and physical activity levels, but the length of physical activity was longer in those who did not meet the MetS diagnosis criteria (p>0.05. An increase in sedentary time raised the MetS criteria (p<0.05. Conclusion: Nearly 1/2 of the patients were at risk of MetS. Physical activity level being statistically ineffective on MetS can be associated with low physical activity level and longer sedentary time. It can be said that being completely sedentary increases BMI and therefore MetS. The study can be repeated on different samples and the results can be compared. [J Contemp Med 2014; 4(2.000: 69-75

  19. Effects of bagging on sugar metabolism and the activity of sugar ...

    African Journals Online (AJOL)

    To investigate the effects of bagging on sugar metabolism and the activity of sugar metabolism related enzymes in Qingzhong loquat fruit development, the contents of sucrose, glucose and soluble solids as well as the activities of sugar metabolism related enzymes were evaluated. The content of sucrose, glucose and ...

  20. Treatment Benefits on Metabolic Syndrome with Diet and Physical Activity

    Directory of Open Access Journals (Sweden)

    Gani Dragusha

    2010-05-01

    Full Text Available The research has included 422 patients aged between 25 to 60, of whom 341 were men and 81 women. The purpose of research was to determine impact of diet and physical activity in the treatment of metabolic syndrome during the six month period.Processing of results through descriptive and discriminative analysis have indicated that 6 month treatment with diet and physical activity have had an impact in the: waistline decrease by 6,05 cm or 5,50% among males, and 4,92 cm or 5,10% among females; body mass index (BMI decrease by 1.78 or 6.20% among males, and 2,3 or 8,16% among females; decrease of blood triglycerides levels by 0,35 mmol/L or 16,28% among males, and 0,27 mmol/L or 13,30% among females; increase of blood cholesterol HDL-C by 0,48 mmol/L or 34,78% among males, and 0,06 mmol/L or 4,28% among females; systolic arterial pressure decreased by 15 mmHg or 10,18%, and diastolic blood pressure by 8,74 mmHg or 9,47% among males, and systolic arterial pressure decreased by 7,39 mmHg or 5,17%, and diastolic blood pressure decreased by 5,18 mmHg or 5,75% among females; the level of blood glucose decreased by 0,45 mmol/L or 7,04% among males, and by 0,64 mmol/L or 9,92% decreased among females.The results show that physical exercise and diet are important factors in reducing the values symptoms of metabolic syndrome.In order to improve symptoms of metabolic syndrome, it is necessary to keep on with healthy diet and physical exercise that means the change of lifestyle.

  1. Metabolic Equivalent in Adolescents, Active Adults and Pregnant Women

    Directory of Open Access Journals (Sweden)

    Katarina Melzer

    2016-07-01

    Full Text Available “Metabolic Equivalent” (MET represents a standard amount of oxygen consumed by the body under resting conditions, and is defined as 3.5 mL O2/kg × min or ~1 kcal/kg × h. It is used to express the energy cost of physical activity in multiples of MET. However, universal application of the 1-MET standard was questioned in previous studies, because it does not apply well to all individuals. Height, weight and resting metabolic rate (RMR, measured by indirect calorimetry were measured in adolescent males (n = 50 and females (n = 50, women during pregnancy (gestation week 35–41, n = 46, women 24–53 weeks postpartum (n = 27, and active men (n = 30, and were compared to values predicted by the 1-MET standard. The RMR of adolescent males (1.28 kcal/kg × h was significantly higher than that of adolescent females (1.11 kcal/kg × h, with or without the effects of puberty stage and physical activity levels. The RMR of the pregnant and post-pregnant subjects were not significantly different. The RMR of the active normal weight (0.92 kcal/kg × h and overweight (0.89 kcal/kg × h adult males were significantly lower than the 1-MET value. It follows that the 1-MET standard is inadequate for use not only in adult men and women, but also in adolescents and physically active men. It is therefore recommended that practitioners estimate RMR with equations taking into account individual characteristics, such as sex, age and Body Mass Index, and not rely on the 1-MET standard.

  2. Correlation of BAT activity with thyroid metabolic activity in patients with fibromyalgia

    Science.gov (United States)

    Costa, A. P. C.; Maia, J. M.; Brioschi, M. L.; Machado, J. E. M. M.

    2017-03-01

    The objective of this research is to correlate the brown fat activity (BAT) with the metabolic activity of thyroid in patients with fibromyalgia syndrome (FS). For the development of the research, it was select a database containing 132 patients of a thermography clinic, male and female, with age over 18 years old; where the images selected were anteroposterior orthostasis top and anteroposterior in cervical extension. In the program Flir Report, it was possible to demarcate the region of the left and right interscapular and thyroid of each patient by getting the respective temperatures, in addition to view the hyper-radiation ("signal of mantle") in the interscapular. Temperature was organized in table format, and statistical analysis was performed in the program Microcal Origin 6.0. As conclusion, it was found that the greater the metabolic activity of thyroid in patients with fibromyalgia, the greater will be the metabolic rate of brown fat (BAT).

  3. Physical Activity Dimensions Associated with Impaired Glucose Metabolism

    DEFF Research Database (Denmark)

    Amadid, Hanan; Johansen, Nanna B.; Bjerregaard, Anne-Louise

    2017-01-01

    PURPOSE: Physical activity (PA) is important in the prevention of type 2 diabetes, yet little is known about the role of specific dimensions of PA, including sedentary time in subgroups at risk of impaired glucose metabolism (IGM). We applied a data driven decision tool to identify dimensions of PA...... associated with IGM across age, sex and body mass index (BMI) groups. METHODS: This cross-sectional study included 1,501 individuals (mean (SD) age 65.6 (6.8) years) at high risk of type 2 diabetes from the ADDITION-PRO study. PA was measured by an individually calibrated combined accelerometer and heart...... subgroups in which different activity dimensions were associated with IGM. Methodology and results from this study may suggest a preliminary step towards the goal of tailoring and targeting PA interventions aimed at type 2 diabetes prevention....

  4. Simvastatin Inhibits Glucose Metabolism and Legumain Activity in Human Myotubes

    Science.gov (United States)

    Smith, Robert; Solberg, Rigmor; Jacobsen, Linn Løkken; Voreland, Anette Larsen; Rustan, Arild Christian; Thoresen, G. Hege; Johansen, Harald Thidemann

    2014-01-01

    Simvastatin, a HMG-CoA reductase inhibitor, is prescribed worldwide to patients with hypercholesterolemia. Although simvastatin is well tolerated, side effects like myotoxicity are reported. The mechanism for statin-induced myotoxicity is still poorly understood. Reports have suggested impaired mitochondrial dysfunction as a contributor to the observed myotoxicity. In this regard, we wanted to study the effects of simvastatin on glucose metabolism and the activity of legumain, a cysteine protease. Legumain, being the only known asparaginyl endopeptidase, has caspase-like properties and is described to be involved in apoptosis. Recent evidences indicate a regulatory role of both glucose and statins on cysteine proteases in monocytes. Satellite cells were isolated from the Musculus obliquus internus abdominis of healthy human donors, proliferated and differentiated into polynuclear myotubes. Simvastatin with or without mevalonolactone, farnesyl pyrophosphate or geranylgeranyl pyrophosphate were introduced on day 5 of differentiation. After 48 h, cells were either harvested for immunoblotting, ELISA, cell viability assay, confocal imaging or enzyme activity analysis, or placed in a fuel handling system with [14C]glucose or [3H]deoxyglucose for uptake and oxidation studies. A dose-dependent decrease in both glucose uptake and oxidation were observed in mature myotubes after exposure to simvastatin in concentrations not influencing cell viability. In addition, simvastatin caused a decrease in maturation and activity of legumain. Dysregulation of glucose metabolism and decreased legumain activity by simvastatin points out new knowledge about the effects of statins on skeletal muscle, and may contribute to the understanding of the myotoxicity observed by statins. PMID:24416446

  5. Inferring the tectonic setting of the Gamburtsev Subglacial Mts by ice cap surface lineaments

    Science.gov (United States)

    Cianfarra, Paola; Salvini, Francesco

    2010-05-01

    Gamburtsev Subglacial Mts (GSM) are by far one of the most puzzling physiographic feature of the East Antactic craton. Located at the centre of the Antarctic continent and beneath the highest point of East Antarctic Ice Sheet (Dome A) they were discovered during the 1957-58 International Geophysical Year by a Soviet expedition using seismic instruments to measure the thickness of the ice sheet. This intracratonic mountain range is characterised by peaks with elevation exceeding 3500 m and covers an area bigger than the European Alps. The GSM were the target of a huge international geophysical expedition during the 2008-2009 summer season with the aim of revealing the geologic nature and origin of this mountain range, as well as to further understand the tectonic setting of two of the largest Antarctic subglacial lakes bounding to the East and to the West the GSM, namely the Vostok and Recovery lakes. Preliminary results of this international scientific campaign have been presented to the scientific community and showed that the GSM are characterised by a typical alpine landscape with a rectangular hydrographic network. These morphological features are commonly associated to recent/active tectonics. At present, four scenarios exists to explain the existence of such intracratonic mountain range: (i) a hot-spot beneath the Antarctic crust, in a Hoggar-like mantle plume scenario; (ii) a continental collision (of unknown age) similarly to the Alpine orogenic belt; (iii) a rifting process associated to flexural uplift or isostatic rebound of the rift shoulder, in a Transantarctic Mts like scenario or similarly to the mountains along the edges of the East African rift lakes; and (iv) a continental arching related to regional, continental-scale stress like the Black Hills in the North America continent or the russian platform arching located NE of Moscow. These geodynamic scenarios are characterised by different morpho-tectonic signatures that can be successfully

  6. Does physical activity during pregnancy adversely influence markers of the metabolic syndrome in adult offspring?

    DEFF Research Database (Denmark)

    Danielsen, Inge; Granström, Charlotta; Rytter, Dorte

    2013-01-01

    It is unknown whether physical activity during pregnancy (PA) has long-term impact on the metabolic profile of the offspring. We investigated associations of PA with markers of the metabolic syndrome (MS) in 20y old offspring.......It is unknown whether physical activity during pregnancy (PA) has long-term impact on the metabolic profile of the offspring. We investigated associations of PA with markers of the metabolic syndrome (MS) in 20y old offspring....

  7. Automatic detection of subglacial lakes in radar sounder data acquired in Antarctica

    Science.gov (United States)

    Ilisei, Ana-Maria; Khodadadzadeh, Mahdi; Dalsasso, Emanuele; Bruzzone, Lorenzo

    2017-10-01

    Subglacial lakes decouple the ice sheet from the underlying bedrock, thus facilitating the sliding of the ice masses towards the borders of the continents, consequently raising the sea level. This motivated increasing attention in the detection of subglacial lakes. So far, about 70% of the total number of subglacial lakes in Antarctica have been detected by analysing radargrams acquired by radar sounder (RS) instruments. Although the amount of radargrams is expected to drastically increase, from both airborne and possible future Earth observation RS missions, currently the main approach to the detection of subglacial lakes in radargrams is by visual interpretation. This approach is subjective and extremely time consuming, thus difficult to apply to a large amount of radargrams. In order to address the limitations of the visual interpretation and to assist glaciologists in better understanding the relationship between the subglacial environment and the climate system, in this paper, we propose a technique for the automatic detection of subglacial lakes. The main contribution of the proposed technique is the extraction of features for discriminating between lake and non-lake basal interfaces. In particular, we propose the extraction of features that locally capture the topography of the basal interface, the shape and the correlation of the basal waveforms. Then, the extracted features are given as input to a supervised binary classifier based on Support Vector Machine to perform the automatic subglacial lake detection. The effectiveness of the proposed method is proven both quantitatively and qualitatively by applying it to a large dataset acquired in East Antarctica by the MultiChannel Coherent Radar Depth Sounder.

  8. Metabolic pathways in immune cell activation and quiescence.

    Science.gov (United States)

    Pearce, Erika L; Pearce, Edward J

    2013-04-18

    Studies of immune system metabolism ("immunometabolism") segregate along two paths. The first investigates the effects of immune cells on organs that regulate whole-body metabolism, such as adipose tissue and liver. The second explores the role of metabolic pathways within immune cells and how this regulates immune response outcome. Distinct metabolic pathways diverge and converge at many levels, and, therefore, cells face choices as to how to achieve their metabolic goals. There is interest in fully understanding how and why immune cells commit to particular metabolic fates and in elucidating the immunologic consequences of reaching a metabolic endpoint by one pathway versus another. This is particularly intriguing, given that metabolic commitment is influenced not only by substrate availability but also by signaling pathways elicited by metabolites. Thus, metabolic choices in cells enforce fate and function, and this area will be the subject of this review. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. HEALTHY intervention: fitness, physical activity, and metabolic syndrome results.

    Science.gov (United States)

    Jago, Russell; McMurray, Robert G; Drews, Kimberly L; Moe, Esther L; Murray, Tinker; Pham, Trang H; Venditti, Elizabeth M; Volpe, Stella L

    2011-08-01

    This study aimed to assess the effect of the HEALTHY intervention on the metabolic syndrome (Met-S), fitness, and physical activity levels of US middle-school students. Cluster randomized controlled trial conducted in 42 (21 intervention) US middle schools. Participants were recruited at the start of sixth grade (2006) when baseline assessments were made, with post-assessments made 2.5 yr later at the end of eighth grade (2009). The HEALTHY intervention had four components: 1) improved school food environment, 2) physical activity and eating educational sessions, 3) social marketing, and 4) revised physical education curriculum. Met-S risk factors, 20-m shuttle run (fitness), and self-reported moderate to vigorous physical activity (MVPA) were assessed at each time point. Ethnicity and gender were self-reported. Obesity status (normal weight, overweight, or obese) was also assessed. At baseline, 5% of the participants were classified with Met-S, with two-thirds of the males and one-third of the females recording below average baseline fitness levels. Control group participants reported 96 min of MVPA at baseline with 103 min reported by the intervention group. There were no statistically significant (P physical activity levels. Approaches that focus on how to change physical activity, fitness, and Met-S using nonschool or perhaps in addition to school based components need to be developed.

  10. Subglacial sediment provenance and transport in West Antarctica from micropaleontologic analysis of Subglacial Lake Whillans and the upstream sectors of the Whillans and Kamb ice streams

    Science.gov (United States)

    Scherer, Reed; Coenen, Jason; Warny, Sophie

    2014-05-01

    The WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) project recovered sediment cores from Subglacial Lake Whillans (SLW) in West Antarctica. We report preliminary micropaleontological analyses of SLW sediments, augmented by analysis of sediments previously recovered from beneath the upstream camps of the Whillans Ice Stream (WIS) and Kamb Ice Stream (KIS). Microfossils in these sediments (notably diatoms, sponge spicules, and organic-walled palynomorphs), include information regarding sediment transport, subglacial physical processes and ice sheet history. Absolute abundance (particles per gram dry sediment) of identifiable diatoms and diatom fragments in different size classes were calculated to compare and contrast each environment. Sponge spicules are being analyzed for taphonomic effects from subglacial transport and shearing. Palynomorphs are analyzed for abundance, diversity, and source rock ages. In SLW the upper 30 cm is softer and more water-rich than the underlying sediments. However, no statistically significant variation in microfossil and fragment abundance or taphonomy is noted in these diamictons, which is in agreement with the stratigraphic homogeneity evident from geochemical and geological analyses performed to date. SLW contains 1.52x106 to 1.13x107 diatom fragments per gram, compared with 6.43x106 to 4.63x108 at upstream WIS and 6.13 107 to 1.58x108 at KIS. Whole diatoms are orders of magnitude lower in concentration. Low abundance and poor preservation of diatoms and spicules at SLW suggests relatively long distance transport from their marine sediment source, with evidence of high shear strain, following the subglacial shearing index of Scherer et al. (2004). Upper Miocene diatoms dominate all samples analyzed, though older and younger diatoms are noted as well. The WIS samples exhibit the highest diversity of diatoms, including Paleogene freshwater diatoms. KIS sediments have the highest abundance of whole diatoms, but they

  11. Physical activity and metabolic syndrome among Ethiopian adults.

    Science.gov (United States)

    Workalemahu, Tsegaselassie; Gelaye, Bizu; Berhane, Yemane; Williams, Michelle A

    2013-04-01

    BACKGROUND The global prevalence of chronic noncommunicable diseases (NCDs) is on the rise, with the majority of the growth occurring among populations in developing countries. Few studies have quantified the health benefits for physical activity among sub-Saharan African adults. We examined associations of physical activity with the prevalence of metabolic syndrome (MetS) and its components in Ethiopian men and women. METHODS This cross-sectional study of 1,843 individuals (1,117 men and 726 women) was conducted among working adults (public schools and bank employees) in Addis Ababa, Ethiopia. The study was conducted in accordance with the STEPwise approach of the World Health Organization. Physical activity was assessed using a previously validated Global Physical Activity Questionnaire. MetS was defined according to the International Diabetes Federation criteria. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI). RESULTS The odds of MetS was inversely associated with physical activity in men (P trend = 0.02) but not women (P trend = 0.85). Among men, the OR of MetS comparing those with high vs. low levels of physical activity was 0.56 (95% CI = 0.33-0.97). For women, the corresponding OR was 1.07 (95% CI = 0.57-2.01). Physical activity was significantly and inversely associated with high waist circumference and hypertriglyceridemia among men, but no such associations were observed among women. CONCLUSIONS Higher levels of physical activity were inversely associated with MetS and several individual components among men. No similar trends were observed among women in this cohort, in part because of the small sample size.

  12. The relationship between physical activity levels and metabolic syndrome in male white-collar workers

    OpenAIRE

    Ko, Kwang-Jun; Kim, Eon-Ho; Baek, Un-Hyo; Gang, Zhao; Kang, Seol-Jung

    2016-01-01

    [Purpose] Physical activity is important for preventing and managing metabolic syndrome. White-collar workers can be inherently predisposed to chronic diseases, as their jobs are primarily sedentary. The purpose of this study was to examine the relationship between physical activity and metabolic syndrome in male white-collar workers. [Subjects and Methods] Physical activity and metabolic syndrome factors were measured in 331 male public office workers. Physical activity was classified as hig...

  13. Mitochondrial redox metabolism in trypanosomatids is independent of tryparedoxin activity.

    Directory of Open Access Journals (Sweden)

    Helena Castro

    Full Text Available Tryparedoxins (TXNs are oxidoreductases unique to trypanosomatids (including Leishmania and Trypanosoma parasites that transfer reducing equivalents from trypanothione, the major thiol in these organisms, to sulfur-dependent peroxidases and other dithiol proteins. The existence of a TXN within the mitochondrion of trypanosomatids, capable of driving crucial redox pathways, is considered a requisite for normal parasite metabolism. Here this concept is shown not to apply to Leishmania. First, removal of the Leishmania infantum mitochondrial TXN (LiTXN2 by gene-targeting, had no significant effect on parasite survival, even in the context of an animal infection. Second, evidence is presented that no other TXN is capable of replacing LiTXN2. In fact, although a candidate substitute for LiTXN2 (LiTXN3 was found in the genome of L. infantum, this was shown in biochemical assays to be poorly reduced by trypanothione and to be unable to reduce sulfur-containing peroxidases. Definitive conclusion that LiTXN3 cannot directly reduce proteins located within inner mitochondrial compartments was provided by analysis of its subcellular localization and membrane topology, which revealed that LiTXN3 is a tail-anchored (TA mitochondrial outer membrane protein presenting, as characteristic of TA proteins, its N-terminal end (containing the redox-active domain exposed to the cytosol. This manuscript further proposes the separation of trypanosomatid TXN sequences into two classes and this is supported by phylogenetic analysis: i class I, encoding active TXNs, and ii class II, coding for TA proteins unlikely to function as TXNs. Trypanosoma possess only two TXNs, one belonging to class I (which is cytosolic and the other to class II. Thus, as demonstrated for Leishmania, the mitochondrial redox metabolism in Trypanosoma may also be independent of TXN activity. The major implication of these findings is that mitochondrial functions previously thought to depend on the

  14. NATIONAL SEISMIC, RADAR AND SEISMOLOGICAL STUDIES OF SUBGLACIAL LAKE VOSTOK

    Directory of Open Access Journals (Sweden)

    S. V. Popov

    2012-01-01

    Full Text Available The results of the remote sensing which carried out in the LakeVostokarea are discussed in the paper. A.P. Kapitsa and O.G. Sorokhtin started the geophysical researches in this area in 1950s. Satellite altimetry data, which analyzed in 1990s yielded to the discovering of the LakeVostok. After that, PMGE and RAE started the systematic studying of this natural phenomenon by seismic and radio-echo sounding. Total, 318 seismic soundings and 5190 kmof the radio-echo profiles has been collected by 2008. Special precise measurements which carried out in the 5G-1 borehole vicinity are resulted in the ice thickness over Vostok Station is 3760±30 mby seismic and 3775±15 mby radio-echo sounding. Thus, the error of geophysical measurements is less than 0.3%. The Russian investigations are resulted in definition the border of the lake, the discovering of 56 subglacial water caves around the lake and compilation the maps including ice thickness, ice base and bedrock topography and the depth of the lake. Average depth of the LakeVostokis about 400 m; water volume is 6100 km3. After 2008, the remote sensing works have been concentrated to the studying of the bottom sediments by refraction seismic technique. The firsts result shown that the bottom sediments thickness varies from 400 to1200 m.

  15. Ecology of Subglacial Lake Vostok (Antarctica, Based on Metagenomic/Metatranscriptomic Analyses of Accretion Ice

    Directory of Open Access Journals (Sweden)

    Tom D'Elia

    2013-03-01

    Full Text Available Lake Vostok is the largest of the nearly 400 subglacial Antarctic lakes and has been continuously buried by glacial ice for 15 million years. Extreme cold, heat (from possible hydrothermal activity, pressure (from the overriding glacier and dissolved oxygen (delivered by melting meteoric ice, in addition to limited nutrients and complete darkness, combine to produce one of the most extreme environments on Earth. Metagenomic/metatranscriptomic analyses of ice that accreted over a shallow embayment and over the southern main lake basin indicate the presence of thousands of species of organisms (94% Bacteria, 6% Eukarya, and two Archaea. The predominant bacterial sequences were closest to those from species of Firmicutes, Proteobacteria and Actinobacteria, while the predominant eukaryotic sequences were most similar to those from species of ascomycetous and basidiomycetous Fungi. Based on the sequence data, the lake appears to contain a mixture of autotrophs and heterotrophs capable of performing nitrogen fixation, nitrogen cycling, carbon fixation and nutrient recycling. Sequences closest to those of psychrophiles and thermophiles indicate a cold lake with possible hydrothermal activity. Sequences most similar to those from marine and aquatic species suggest the presence of marine and freshwater regions.

  16. The immune diet: meeting the metabolic demands of lymphocyte activation.

    Science.gov (United States)

    Wang, Ruoning; Green, Douglas R

    2012-01-01

    During the adaptive immune response, lymphocytes undergo dramatic changes in metabolism that accompany the proliferative burst and differentiation into functional subsets. This brief overview focuses on recent advances in understanding the mechanisms of this metabolic reprogramming in T lymphocytes.

  17. The immune diet: meeting the metabolic demands of lymphocyte activation

    OpenAIRE

    Wang, Ruoning; Green, Douglas R.

    2012-01-01

    During the adaptive immune response, lymphocytes undergo dramatic changes in metabolism that accompany the proliferative burst and differentiation into functional subsets. This brief overview focuses on recent advances in understanding the mechanisms of this metabolic reprogramming in T lymphocytes.

  18. Visualizing metabolic activity on a genome-wide scale

    NARCIS (Netherlands)

    Luyf, A. C. M.; de Gast, J.; van Kampen, A. H. C.

    2002-01-01

    Motivation: To enhance the exploration of gene expression data in a metabolic context, one requires an application that allows the integration of this data and which represents this data in a (genome-wide) metabolic map. The layout of this metabolic map must be highly flexible to enable discoveries

  19. Electroporation Enhances the Metabolic Activity of Lactobacillus plantarum 564

    Directory of Open Access Journals (Sweden)

    Branko Bugarski

    2013-01-01

    Full Text Available The exposure of bacterial cells to pulsed electric fields (PEF leads to the reversible formation of pores in the cell membrane if an applied energy is below the critical level. Therefore, the effect of electric field pulses with amplitudes below 14 kV/cm and the applied energy up to 12.2 J/cm3 on the growth of Lactobacillus plantarum 564 cells was investigated. After PEF treatments, the growth of lactobacilli in De Man-Rogosa-Sharpe broth at 37 °C was monitored by isothermal calorimetry, absorbance and plate counts. All the applied treatments resulted in a higher growth rate of PEF-treated cells during early and mid-log phase, especially bacterial samples treated with lower field intensities (1.3–5.5 J/cm3. The transport of ions and molecules through the cell membrane (which facilitates the growth of electroporated lactobacilli was particularly evident in the mid-exponential growth phase, where the doubling time was reduced more than 3 times after the exposure to electric pulses of 5.5 J/cm3. The heat production rate during the growth of electroporated cells was also higher, indicating the enhanced metabolic activity of PEF-treated cells. Moreover, the electroporated cells had a better acidification ability than the untreated ones. It can be summarized that the applied PEF treatments with an energy input of below 12 J/cm3 potentially induce reversible electroporation of the cell membrane, which has a positive impact on the growth and metabolic activity of the cells of lactobacilli.

  20. The relationship between physical activity levels and metabolic syndrome in male white-collar workers

    Science.gov (United States)

    Ko, Kwang-Jun; Kim, Eon-Ho; Baek, Un-Hyo; Gang, Zhao; Kang, Seol-Jung

    2016-01-01

    [Purpose] Physical activity is important for preventing and managing metabolic syndrome. White-collar workers can be inherently predisposed to chronic diseases, as their jobs are primarily sedentary. The purpose of this study was to examine the relationship between physical activity and metabolic syndrome in male white-collar workers. [Subjects and Methods] Physical activity and metabolic syndrome factors were measured in 331 male public office workers. Physical activity was classified as high (N=101), moderate (N=115), or low (N=111) using the International Physical Activity Questionnaire. To diagnose metabolic syndrome, the U.S. National Cholesterol Education Program’s standard was used. [Results] Waist circumference and triglyceride levels, factors of metabolic syndrome, were significantly higher in the low physical activity group than in the moderate or high activity group. High-density lipoprotein cholesterol was significantly lower in the low physical activity group than in the moderate or high activity group. Waist circumference and fasting glucose were negatively correlated with physical activity level, and HDL cholesterol showed a positive correlation with waist circumference. The odds ratios for metabolic syndrome were 2.03 times higher (95% confidence interval, 1.01–4.09) in the low physical activity group than in the high physical activity group. [Conclusion] Low physical activity was a risk factor for metabolic syndrome in white-collar workers. Therefore, increasing physical activity in daily life may prevent metabolic syndrome in white-collar workers. PMID:27942116

  1. The relationship between physical activity levels and metabolic syndrome in male white-collar workers.

    Science.gov (United States)

    Ko, Kwang-Jun; Kim, Eon-Ho; Baek, Un-Hyo; Gang, Zhao; Kang, Seol-Jung

    2016-11-01

    [Purpose] Physical activity is important for preventing and managing metabolic syndrome. White-collar workers can be inherently predisposed to chronic diseases, as their jobs are primarily sedentary. The purpose of this study was to examine the relationship between physical activity and metabolic syndrome in male white-collar workers. [Subjects and Methods] Physical activity and metabolic syndrome factors were measured in 331 male public office workers. Physical activity was classified as high (N=101), moderate (N=115), or low (N=111) using the International Physical Activity Questionnaire. To diagnose metabolic syndrome, the U.S. National Cholesterol Education Program's standard was used. [Results] Waist circumference and triglyceride levels, factors of metabolic syndrome, were significantly higher in the low physical activity group than in the moderate or high activity group. High-density lipoprotein cholesterol was significantly lower in the low physical activity group than in the moderate or high activity group. Waist circumference and fasting glucose were negatively correlated with physical activity level, and HDL cholesterol showed a positive correlation with waist circumference. The odds ratios for metabolic syndrome were 2.03 times higher (95% confidence interval, 1.01-4.09) in the low physical activity group than in the high physical activity group. [Conclusion] Low physical activity was a risk factor for metabolic syndrome in white-collar workers. Therefore, increasing physical activity in daily life may prevent metabolic syndrome in white-collar workers.

  2. The metabolic activator FOXO1 binds hepatitis B virus DNA and activates its transcription

    Energy Technology Data Exchange (ETDEWEB)

    Shlomai, Amir, E-mail: amirsh@tasmc.health.gov.il [Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100 (Israel); Institute for Gastroenterology and Liver disease, Tel-Aviv Sourasky Medical Center, 6 Weizmann street, Tel-Aviv (Israel); Shaul, Yosef [Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100 (Israel)

    2009-04-17

    Hepatitis B virus (HBV) is a small DNA virus that targets the liver and infects humans worldwide. Recently we have shown that the metabolic regulator PGC-1{alpha} coactivates HBV transcription thereby rendering the virus susceptible to fluctuations in the nutritional status of the liver. PGC-1{alpha} coactivation of HBV is mediated through the liver-enriched nuclear receptor HNF4{alpha} and through another yet unknown transcription factor(s). Here we show that the forkhead transcription factor FOXO1, a known target for PGC-1{alpha} coactivation and a central mediator of glucose metabolism in the liver, binds HBV core promoter and activates its transcription. This activation is further enhanced in the presence of PGC-1{alpha}, implying that FOXO1 is a target for PGC-1{alpha} coactivation of HBV transcription. Thus, our results identify another key metabolic regulator as an activator of HBV transcription, thereby supporting the principle that HBV gene expression is regulated in a similar way to key hepatic metabolic genes.

  3. Subglacial bedforms and conditions associated with the 1991 surge of Skeidarárjökull, Iceland

    NARCIS (Netherlands)

    Waller, R.I.; Dijk, T. van; Knudson, O.

    2008-01-01

    Much previous research at surge-type glaciers has sought to identify features diagnostic of surge-type behaviour. However, in comparatively little work have subglacial landform-sediment characteristics been used to reconstruct changing basal processes and conditions during surge events. Subglacial

  4. An isotopic model for basal freeze-on associated with subglacial upward flow of pore water

    Science.gov (United States)

    Souchez, R.; Samyn, D.; Lorrain, R.; Pattyn, F.; Fitzsimons, S.

    2004-01-01

    Subglacial freezing in polar glaciers can have a significant dynamical effect. Recent studies have shown that freezing of pore water flowing upward through subglacial fine-grained sediments at the freezing interface and progression of this freezing front downward are responsible for fast ice flow stoppage in ice streams. The upward pore water flow leads to the formation of debris-bearing basal ice layers. A model for stable isotope composition, both in δD and δ18O, is developed for predicting the isotopic composition of the ice segregated by such a mechanism. The development of this isotopic model for water films present along the grains of the subglacial sediment predicts the absence of apparent fractionation for the ice formed. This prediction is tested against two East Antarctic outlet glaciers by studying the δD-δ18O relationships in the basal ice layers of these glaciers.

  5. A new methodology to simulate subglacial deformation of water saturated granular material

    DEFF Research Database (Denmark)

    Damsgaard, Anders; Egholm, David Lundbek; Piotrowski, Jan A.

    2015-01-01

    can cause variations in the pore-fluid pressure. The pressure variations weaken or strengthen the granular phase, and in turn influence the distribution of shear strain with depth. In permeable sediments the strain distribution is governed by the grain-size distribution and effective normal stress...... of subglacial sediment to the shear stress of an overriding glacier. In this study, we present a new methodology designed to simulate subglacial deformation using a coupled numerical model for computational experiments on grain-fluid mixtures. The granular phase is simulated on a per-grain basis by the discrete......The dynamics of glaciers are to a large degree governed by processes operating at the ice-bed interface, and one of the primary mechanisms of glacier flow over soft unconsolidated sediments is subglacial deformation. However, it has proven difficult to constrain the mechanical response...

  6. Examples of Models Fit to Magnetic Anomalies Observed Over Subaerial, Submarine, and Subglacial Volcanoes in the West Antarctic Rift System

    Science.gov (United States)

    Behrendt, J. C.; Finn, C. A.; Blankenship, D. D.

    2006-12-01

    Aeromagnetic and marine magnetic surveys over the volcanically active West Antarctic rift system, constrained by seismic reflection profiles over the Ross Sea continual shelf, and radar ice sounding surveys over the West Antarctic Ice Sheet (WAIS) allowed calculation of models fit to very high-amplitude anomalies. We present several examples: exposed 2700-m high, subaerial erupted volcano Mt Melbourne; the 750-m high source of anomaly D (Hamilton submarine volcano) in the Ross sea; and the 600-m high edifice of Mt. CASERTZ beneath the WAIS. The character of these anomalies and their sources varies greatly, and is inferred to be the result of subaerial, submarine and subglacial emplacement respectively. Mt. Melbourne erupted through the WAIS at a time when it was grounded over the Ross Sea continental shelf. Highly magnetic volcanic flows inferred to have high remanent (normal) magnetization in the present field direction produce the 600-nT positive anomaly. The flows protected the edifice above the ice from erosion. Negligible amounts of probably subglacially erupted, apparently non-magnetic hyaloclastite exist in association with Mt. Melbourne. Mt. CASERTZ is nonmagnetic and the edifice is interpreted as consisting of a transient mound of unconsolidated hyaloclastite injected into the WAIS. However Mt. CASERTZ, about 8-km diameter, overlies a 200-m high, 40-km wide highly magnetic residual edifice modeled as the top of the source (an active subglacial volcano) of a 400-nT high positive anomaly. Any former edifices comprising hyaloclastite, pillow breccia or other volcanic debris injected into the moving WAIS apparently have been removed. About 400 other high- amplitude anomalies associated with low relief (80 percent less than 200 m) edifices at the base of the ice (the tops of the sources of these steep gradient anomalies) beneath the WAIS defined by radar ice sounding have been interpreted as having former hyaloclastite edifices, which were removed by the moving

  7. Adipokines (adiponectin and plasminogen activator inhhibitor-1 in metabolic syndrome

    Directory of Open Access Journals (Sweden)

    M K Garg

    2012-01-01

    Full Text Available Background: The clustering of cardiovascular risk factors is termed the metabolic syndrome (MS, which strongly predicts the risk of diabetes and cardiovascular disease (CVD. Adipokines may contribute to the development of obesity and insulin resistance and may be a causal link between MS, diabetes and CVD. Hence, we studied the adipokines - adiponectin and plasminogen activator inhibitor-1 (PAI-1 - in subjects with MS. Materials and Methods: We studied 50 subjects with MS diagnosed by International Diabetes Federation (IDF criteria and 24 healthy age- and sex-matched controls. Clinical evaluation included anthropometry, body fat analysis by bioimpedance, highly sensitive C-reactive protein, insulin, adiponectin, and PAI-1 measurement. Results: Subjects with MS had lower adiponectin (4.01 ± 2.24 vs. 8.7 ± 1.77 μg/ml; P < 0.0001 and higher PAI-1 (53.85 ± 16.45 vs. 17.35 ± 4.45 ng/ml; P < 0.0001 levels than controls. Both were related with the number of metabolic abnormalities. Adiponectin was negatively and PAI-1 was positively associated with body mass index, waist hip ratio (WHR, body fat mass, percent body fat, and all the parameters of MS, except HDL where the pattern reversed. WHR and triglycerides were independent predictors of adipokines in multiple regression analysis. Receiver operating characteristic curve analysis showed that adiponectin (6.7 μg/ml and PAI-1 (25.0 ng/ml levels predicted the MS with high sensitivity, specificity and accuracy in Indian population. Conclusions: Subjects with MS have lower adiponectin and higher PAI-1 levels compared to healthy controls. Lifestyle measures have been shown to improve the various components of MS, and hence there is an urgent need for public health measures to prevent the ongoing epidemic of diabetes and CVD.

  8. Metabolic signals and innate immune activation in obesity and exercise.

    Science.gov (United States)

    Ringseis, Robert; Eder, Klaus; Mooren, Frank C; Krüger, Karsten

    2015-01-01

    The combination of a sedentary lifestyle and excess energy intake has led to an increased prevalence of obesity which constitutes a major risk factor for several co-morbidities including type 2 diabetes and cardiovascular diseases. Intensive research during the last two decades has revealed that a characteristic feature of obesity linking it to insulin resistance is the presence of chronic low-grade inflammation being indicative of activation of the innate immune system. Recent evidence suggests that activation of the innate immune system in the course of obesity is mediated by metabolic signals, such as free fatty acids (FFAs), being elevated in many obese subjects, through activation of pattern recognition receptors thereby leading to stimulation of critical inflammatory signaling cascades, like IκBα kinase/nuclear factor-κB (IKK/NF- κB), endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) and NOD-like receptor P3 (NLRP3) inflammasome pathway, that interfere with insulin signaling. Exercise is one of the main prescribed interventions in obesity management improving insulin sensitivity and reducing obesity- induced chronic inflammation. This review summarizes current knowledge of the cellular recognition mechanisms for FFAs, the inflammatory signaling pathways triggered by excess FFAs in obesity and the counteractive effects of both acute and chronic exercise on obesity-induced activation of inflammatory signaling pathways. A deeper understanding of the effects of exercise on inflammatory signaling pathways in obesity is useful to optimize preventive and therapeutic strategies to combat the increasing incidence of obesity and its comorbidities. Copyright © 2015 International Society of Exercise and Immunology. All rights reserved.

  9. Metabolic activity of permafrost bacteria below the freezing point

    Science.gov (United States)

    Rivkina, E. M.; Friedmann, E. I.; McKay, C. P.; Gilichinsky, D. A.

    2000-01-01

    Metabolic activity was measured in the laboratory at temperatures between 5 and -20 degrees C on the basis of incorporation of (14)C-labeled acetate into lipids by samples of a natural population of bacteria from Siberian permafrost (permanently frozen soil). Incorporation followed a sigmoidal pattern similar to growth curves. At all temperatures, the log phase was followed, within 200 to 350 days, by a stationary phase, which was monitored until the 550th day of activity. The minimum doubling times ranged from 1 day (5 degrees C) to 20 days (-10 degrees C) to ca. 160 days (-20 degrees C). The curves reached the stationary phase at different levels, depending on the incubation temperature. We suggest that the stationary phase, which is generally considered to be reached when the availability of nutrients becomes limiting, was brought on under our conditions by the formation of diffusion barriers in the thin layers of unfrozen water known to be present in permafrost soils, the thickness of which depends on temperature.

  10. Altered Activities of Antioxidant Enzymes in Patients with Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Lucie Vávrová

    2013-02-01

    Full Text Available Objective: In the pathogenesis of the metabolic syndrome (MetS, an increase of oxidative stress could play an important role which is closely linked with insulin resistance, endothelial dysfunction, and chronic inflammation. The aim of our study was to assess several parameters of the antioxidant status in MetS. Methods: 40 subjects with MetS and 40 age- and sex-matched volunteers without MetS were examined for activities of superoxide dismutase (CuZnSOD, catalase (CAT, glutathione peroxidase 1 (GPX1, glutathione reductase (GR, paraoxonase1 (PON1, concentrations of reduced glutathione (GSH, and conjugated dienes in low-density lipoprotein (CD-LDL. Results: Subjects with MetS had higher activities of CuZnSOD (p Conclusions: Our results implicated an increased oxidative stress in MetS and a decreased antioxidative defense that correlated with some laboratory (triglycerides, high-density lipoprotein cholesterol (HDL-C and clinical (waist circumference, blood pressure components of MetS.

  11. Long-term subglacial sliding patterns based on a sliding law with cavitation

    DEFF Research Database (Denmark)

    Ugelvig, Sofie Vej; Egholm, D.L.

    In ice-sheet models and glacial landscape evolution models, subglacial sliding rates are often related to basal shear stress by a power-law. However, the power-law relationship implies that the subglacial bed can provide unlimited levels of basal drag as sliding rates increases, which is recogniz...... of cavitation on glacier sliding. Proc. R. Soc. A , 461, 609-627 (2005). Egholm et al. Modeling the flow of glaciers in steep terrains: The integrated second-order shallow ice approximation (iSOSIA). Journal of Geophysical Research, 116, F02012 (2011)....

  12. Feedbacks between subglacial dynamics and long-term glacial landscape evolution

    DEFF Research Database (Denmark)

    Brædstrup, Christian; Egholm, D.L.; Ugelvig, Sofie Vej

    computational experiments with a higher-order ice sheet model (Egholm et al., 2009) capable of simulating the long-term evolution of subglacial dynamics at a high spatial resolution. The orientation and magnitude of subglacial stress components depend not only on ice thickness and ice surface gradients...... associated to the level of cavitation (Iverson, 2012). The highly non-linear computational experiments are made possible by new and very efficient GPU-accelerated multigrid algorithms. The computational experiments show that higher-order stress effects associated with local changes to the bed gradient...

  13. Physical Activity and Sedentary Behavior Associated with Components of Metabolic Syndrome among People in Rural China

    OpenAIRE

    Xiao, Jing; Shen, Chong; Chu, Min J.; Gao, Yue X.; Xu, Guang F.; Huang, Jian P.; Xu, Qiong Q.; Cai, Hui

    2016-01-01

    Background Metabolic syndrome is prevalent worldwide and its prevalence is related to physical activity, race, and lifestyle. Little data is available for people living in rural areas of China. In this study we examined associations of physical activity and sedentary behaviors with metabolic syndrome components among people in rural China. Methods The Nantong Metabolic Syndrome Study recruited 13,505 female and 6,997 male participants between 2007 and 2008. Data of socio-demographic character...

  14. Metabolic syndrome risk score and time expended in moderate to vigorous physical activity in adolescents.

    Science.gov (United States)

    Stabelini Neto, Antonio; de Campos, Wagner; Dos Santos, Géssika Castilho; Mazzardo Junior, Oldemar

    2014-02-14

    The clustering of metabolic syndrome risk factors is inversely related to the amount of physical activity. However, the question remains as to how much daily physical activity is enough to prevent the onset of metabolic disorders in adolescents? Therefore, the objectives of this study were to associate the metabolic risk score with the moderate to vigorous physical activity (MVPA) and to identify the amount of daily physical activity to prevent the onset of the metabolic risk factors in Brazilian adolescents. The study involved 391 participants aged 10 to 18 years. Physical activity was measured by accelerometry. The counts obtained in the different activities were transformed into metabolic equivalents and classified as light (≥ 1.5 but activities. The continuous risk score for metabolic syndrome was calculated using the following risk factors: waist circumference, blood pressure, blood glucose, HDL-C and triglycerides. Time spent in MVPA was inversely associated with the continuous risk score for metabolic syndrome (p physical activity relates to metabolic syndrome in adolescents. This population should be encouraged to gradually replace part of their sedentary time with physical activities.

  15. Refined broad-scale sub-glacial morphology of Aurora Subglacial Basin, East Antarctica derived by an ice-dynamics-based interpolation scheme

    Directory of Open Access Journals (Sweden)

    J. L. Roberts

    2011-07-01

    Full Text Available Ice thickness data over much of East Antarctica are sparse and irregularly distributed. This poses difficulties for reconstructing the homogeneous coverage needed to properly assess underlying sub-glacial morphology and fundamental geometric constraints on sea level rise. Here we introduce a new physically-based ice thickness interpolation scheme and apply this to existing ice thickness data in the Aurora Subglacial Basin region. The skill and robustness of the new reconstruction is demonstrated by comparison with new data from the ICECAP project. The interpolated morphology shows an extensive marine-based ice sheet, with considerably more area below sea-level than shown by prior studies. It also shows deep features connecting the coastal grounding zone with the deepest regions in the interior. This has implications for ice sheet response to a warming ocean and underscores the importance of obtaining additional high resolution data in these marginal zones for modelling ice sheet evolution.

  16. Tidal switch on metabolic activity: Salinity induced responses on bacterioplankton metabolic capabilities in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Thottathil, S.D.; Balachandran, K.K.; Jayalakshmy, K.V.; Gupta, G.V.M.; Nair, S.

    -tolerant retrievable counts also accounted for the metabolic variation of bacterioplankton during low and high tides, respectively. The shift in the substrate utilization from carbohydrates to amino acids appears to be due to the physiological adaptation or nitrogen...

  17. Model-driven multi-omic data analysis elucidates metabolic immunomodulators of macrophage activation

    Energy Technology Data Exchange (ETDEWEB)

    Bordbar, Aarash; Mo, Monica L.; Nakayasu, Ernesto S.; Rutledge, Alexandra C.; Kim, Young-Mo; Metz, Thomas O.; Jones, Marcus B.; Frank, Bryan C.; Smith, Richard D.; Peterson, Scott N.; Hyduke, Daniel R.; Adkins, Joshua N.; Palsson, Bernhard O.

    2012-06-26

    Macrophages are central players in the immune response, manifesting divergent phenotypes to control inflammation and innate immunity through the release of cytokines and other regulatory factor-dependent signaling pathways. In recent years, the focus on metabolism has been reemphasized as critical signaling and regulatory pathways of human pathophysiology, ranging from cancer to aging, often converge on metabolic responses. Here, we used genome-scale modeling and multi-omics (transcriptomics, proteomics, and metabolomics) analysis to assess metabolic features critical for macrophage functions. We constructed a genome-scale metabolic network for the RAW 264.7 cell line to determine metabolic modulators of macrophage activation. Metabolites well-known to be associated with immunoactivation (e.g., glucose and arginine) and immunosuppression (e.g., tryptophan and vitamin D3) were amongst the most critical effectors. Intracellular metabolic mechanisms linked to critical suppressive effectors were then assessed, identifying a suppressive role for de novo nucleotide synthesis. Finally, the underlying metabolic mechanisms of macrophage activation are identified by analyzing multi-omic data obtained from LPS-stimulated RAW cells in the context of our flux-based predictions. Our study demonstrates metabolism's role in regulating activation may be greater than previously anticipated and elucidates underlying metabolic connections between activation and metabolic effectors.

  18. Metabolic adaptation to intermittent fasting is independent of peroxisome proliferator-activated receptor alpha

    Directory of Open Access Journals (Sweden)

    Guolin Li

    2018-01-01

    Conclusions: These findings indicate that PPARA activation prior to acute fasting cannot ameliorate fasting-induced hepatic steatosis, whereas EODF induced metabolic adaptations to protect against fasting-induced steatosis without altering PPARA signaling. Therefore, PPARA activation does not mediate the metabolic adaptation to fasting, at least in preventing acute fasting-induced steatosis.

  19. Metabolic activity of Glomus intraradices in Arum- and Paris-type arbuscular mycorrhizal colonization

    NARCIS (Netherlands)

    van Aarle, IM; Cavagnaro, TR; Smith, SE; Dickson, S

    Colonization of two plant species by Glomus intraradices was studied to investigate the two morphological types (Arum and Paris), their symbiotic interfaces and metabolic activities. Root pieces and sections were stained to observe the colonization and metabolic activity of all mycorrhizal

  20. Physical Activity in Patients with Metabolic Syndrome: At Screening and 3 Years Thereafter

    NARCIS (Netherlands)

    Jansen, H.; Engelsen, C. den; Rutten, G.E.H.M.

    2013-01-01

    Background: Metabolic syndrome is a cluster of risk factors for cardiovascular disease and type 2 diabetes. Physical activity can decrease these risks. Many randomized clinical trials to increase physical activity have demonstrated disappointing results, and implementation in daily practice

  1. A Youth Compendium of Physical Activities: Activity Codes and Metabolic Intensities

    Science.gov (United States)

    BUTTE, NANCY F.; WATSON, KATHLEEN B.; RIDLEY, KATE; ZAKERI, ISSA F.; MCMURRAY, ROBERT G.; PFEIFFER, KARIN A.; CROUTER, SCOTT E.; HERRMANN, STEPHEN D.; BASSETT, DAVID R.; LONG, ALEXANDER; BERHANE, ZEKARIAS; TROST, STEWART G.; AINSWORTH, BARBARA E.; BERRIGAN, DAVID; FULTON, JANET E.

    2018-01-01

    ABSTRACT Purpose A Youth Compendium of Physical Activities (Youth Compendium) was developed to estimate the energy costs of physical activities using data on youth only. Methods On the basis of a literature search and pooled data of energy expenditure measurements in youth, the energy costs of 196 activities were compiled in 16 activity categories to form a Youth Compendium of Physical Activities. To estimate the intensity of each activity, measured oxygen consumption (V˙O2) was divided by basal metabolic rate (Schofield age-, sex-, and mass-specific equations) to produce a youth MET (METy). A mixed linear model was developed for each activity category to impute missing values for age ranges with no observations for a specific activity. Results This Youth Compendium consists of METy values for 196 specific activities classified into 16 major categories for four age-groups, 6–9, 10–12, 13–15, and 16–18 yr. METy values in this Youth Compendium were measured (51%) or imputed (49%) from youth data. Conclusion This Youth Compendium of Physical Activities uses pediatric data exclusively, addresses the age dependency of METy, and imputes missing METy values and thus represents advancement in physical activity research and practice. This Youth Compendium will be a valuable resource for stakeholders interested in evaluating interventions, programs, and policies designed to assess and encourage physical activity in youth. PMID:28938248

  2. Clean hot water drilling for exploration of the Antarctic deep subglacial environment

    Science.gov (United States)

    Makinson, K.; Pearce, D.; Hodgson, D.; Bentley, M.; Smith, A.; Tranter, M.; Rose, M. C.; Ross, N.; Mowlem, M. C.; Parnell, J.; Siegert, M. J.

    2015-12-01

    Overlain by several kilometres of ice, the subglacial environments deep beneath the Antarctic Ice Sheet are regarded as extreme habitats for microbial life and repositories of important paleoclimate records. Of significant scientific interest, yet remaining largely unexplored, accessing and sampling these environments presents several challenges to existing drilling technologies. With over half of the ice sheet believed to be resting on a wet bed, much of it part of a hydrological drainage network, accessing of this environment must conform to international environmental contamination protocols. This makes hot water drilling the most viable option for clean, fast, access through thick ice. After two decades of planning, involving the development of drilling techniques for subglacial access, instrument design and logistics set up, significant progress has been made in attempts to directly access, measure, and sample subglacial lakes and sediments. Combining the experiences from the notable setbacks and successes, as well as recent field testing for this drilling technique, the most practical technical options and operational procedures for future clean entry into Subglacial Lake Ellsworth and other deep (>3000 m) access targets will be presented.

  3. Recent technical developments at the IMAU: A new generation of AWS and wireless subglacial measurements

    NARCIS (Netherlands)

    Smeets, C.J.P.P.; Boot, W.; van den Broeke, M.R.; van de Wal, R.S.W.

    2011-01-01

    Two technical developments are presented: a new generation of AWS and a wireless subglacial measurement system. Both systems build on the experience of the IMAU in developing GPS systems (Den Ouden et al., 2010). Combining methods to minimize energy consumption and wireless communication form the

  4. Paleo ice flow and subglacial meltwater dynamics in Pine Island Bay, West Antarctica

    Directory of Open Access Journals (Sweden)

    F. O. Nitsche

    2013-02-01

    Full Text Available Increasing evidence for an elaborate subglacial drainage network underneath modern Antarctic ice sheets suggests that basal meltwater has an important influence on ice stream flow. Swath bathymetry surveys from previously glaciated continental margins display morphological features indicative of subglacial meltwater flow in inner shelf areas of some paleo ice stream troughs. Over the last few years several expeditions to the eastern Amundsen Sea embayment (West Antarctica have investigated the paleo ice streams that extended from the Pine Island and Thwaites glaciers. A compilation of high-resolution swath bathymetry data from inner Pine Island Bay reveals details of a rough seabed topography including several deep channels that connect a series of basins. This complex basin and channel network is indicative of meltwater flow beneath the paleo-Pine Island and Thwaites ice streams, along with substantial subglacial water inflow from the east. This meltwater could have enhanced ice flow over the rough bedrock topography. Meltwater features diminish with the onset of linear features north of the basins. Similar features have previously been observed in several other areas, including the Dotson-Getz Trough (western Amundsen Sea embayment and Marguerite Bay (SW Antarctic Peninsula, suggesting that these features may be widespread around the Antarctic margin and that subglacial meltwater drainage played a major role in past ice-sheet dynamics.

  5. Physical activity stage-matched intervention: Promoting metabolic control in type 2 diabetes.

    Science.gov (United States)

    Jalilian, Mohsen; Moeini, Babak; Hazavehei, Seyed Mohammad Mehdi; Beigi, Abbas M; Sharifirad, Gholamreza; Nodeh, Farhad Habibi

    2013-01-01

    Regular physical activity has an important role in reducing cardiovascular risk factors and improving metabolic control in patients with type 2 diabetes. This study aims to investigate the effect of physical activity stage-matched intervention on metabolic control in type 2 diabetes patients. An 8-week physical activity program conducted with 50 type 2 diabetes females who were physically inactive and in precontemplation, contemplation, and preparation stages of change. Participants were divided into intervention and control groups (each group, n = 25). Data were collected by physical activity stage of change questionnaire and metabolic factors were measured by laboratory tests before initiation program. Subsequently, stage-matched physical activity program was conducted for the interventional group. Control group received routine education from the diabetes center. After 8 weeks, physical activity questionnaire filled out by participants and metabolic factors were evaluated by a laboratory test. Findings showed patients in the intervention group and compared with control group significantly moved through stages of change after physical activity program (P-value control group and also the difference between groups was significant (P-value metabolism factors after physical activity program showed significant decrease in glycosilated hemoglobin in the intervention group than the control group (P-value metabolism factors. Designing and implementing physical activity stage-matched intervention can improve metabolic control and management of type 2 diabetes.

  6. The relationship between physical activity and metabolic syndrome in people with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Park, Soo Kyung; Larson, Janet L

    2014-01-01

    The prevalence of metabolic syndrome has been reported to be 20% to 50% in people with chronic obstructive pulmonary disease (COPD). Because such people are sedentary and physically inactive, they are at risk of metabolic syndrome. The extent of this problem, however, is not fully understood. This study examined the relationship of sedentary time and physical activity to metabolic syndrome and the components of metabolic syndrome in a population-based sample of people with COPD. This was a secondary analysis of existing cross-sectional data. Subjects with COPD (n = 223) were drawn from the National Health and Nutrition Examination Survey data set (2003-2006). Physical activity was measured by accelerometry. Waist circumference, triglyceride level, high-density lipoprotein cholesterol level, blood pressure, and fasting glucose level were used to describe metabolic syndrome. Descriptive and inferential statistics were used for analysis. Fifty-five percent of the sample had metabolic syndrome. No significant differences in sedentary time and level of physical activity were found in people with COPD and metabolic syndrome and people with COPD only. However, those with a mean activity count of greater than 240 counts per minute had a lower prevalence of metabolic syndrome. Waist circumference and glucose level were significantly associated with the time spent in sedentary, light, and moderate to vigorous physical activity. Metabolic syndrome is highly prevalent in people with COPD, and greater physical activity and less sedentary time are associated with lower rates of metabolic syndrome. This suggests that interventions to decrease the risk of metabolic syndrome in people with COPD should include both reducing sedentary time and increasing the time and intensity of physical activity.

  7. Physical Activity and Sedentary Behavior Associated with Components of Metabolic Syndrome among People in Rural China.

    Science.gov (United States)

    Xiao, Jing; Shen, Chong; Chu, Min J; Gao, Yue X; Xu, Guang F; Huang, Jian P; Xu, Qiong Q; Cai, Hui

    2016-01-01

    Metabolic syndrome is prevalent worldwide and its prevalence is related to physical activity, race, and lifestyle. Little data is available for people living in rural areas of China. In this study we examined associations of physical activity and sedentary behaviors with metabolic syndrome components among people in rural China. The Nantong Metabolic Syndrome Study recruited 13,505 female and 6,997 male participants between 2007 and 2008. Data of socio-demographic characteristics and lifestyle were collected. The associations of physical activity and sedentary behaviors with metabolic syndrome components were analyzed. Prevalence of metabolic syndrome was 21.6%. It was significantly lower in men than in women. Low risks of metabolic syndrome were observed in those who did less sitting and engaged in more vigorous physical activity. The highest tertile of vigorous physical activity was associated with 15-40% decreased odds of metabolic syndrome and all of its components, except for low high-density lipoprotein cholesterol in men. Women with the highest tertile of moderate physical activity had 15-30% lower odds of central obesity, high glucose, and high triglycerides compared with those in the lowest tertile. Sitting time >42 hours per week had a 4%-12% attributable risk of metabolic syndrome, central obesity, and high triglycerides in both genders, and abnormal glucose and diastolic blood pressure in women. Sleeping for more than 8 hours per day was associated with risk of high serum glucose and lipids. Our data suggested that physical activity has a preventive effect against metabolic syndrome and all its abnormal components, and that longer sitting time and sleep duration are associated with an increased risk of metabolic syndrome components, including central obesity and high triglycerides, glucose, and diastolic blood pressure. This study could provide information for future investigation into these associations. Also, recommendations are developed to reduce

  8. Physical Activity and Sedentary Behavior Associated with Components of Metabolic Syndrome among People in Rural China.

    Directory of Open Access Journals (Sweden)

    Jing Xiao

    Full Text Available Metabolic syndrome is prevalent worldwide and its prevalence is related to physical activity, race, and lifestyle. Little data is available for people living in rural areas of China. In this study we examined associations of physical activity and sedentary behaviors with metabolic syndrome components among people in rural China.The Nantong Metabolic Syndrome Study recruited 13,505 female and 6,997 male participants between 2007 and 2008. Data of socio-demographic characteristics and lifestyle were collected. The associations of physical activity and sedentary behaviors with metabolic syndrome components were analyzed.Prevalence of metabolic syndrome was 21.6%. It was significantly lower in men than in women. Low risks of metabolic syndrome were observed in those who did less sitting and engaged in more vigorous physical activity. The highest tertile of vigorous physical activity was associated with 15-40% decreased odds of metabolic syndrome and all of its components, except for low high-density lipoprotein cholesterol in men. Women with the highest tertile of moderate physical activity had 15-30% lower odds of central obesity, high glucose, and high triglycerides compared with those in the lowest tertile. Sitting time >42 hours per week had a 4%-12% attributable risk of metabolic syndrome, central obesity, and high triglycerides in both genders, and abnormal glucose and diastolic blood pressure in women. Sleeping for more than 8 hours per day was associated with risk of high serum glucose and lipids.Our data suggested that physical activity has a preventive effect against metabolic syndrome and all its abnormal components, and that longer sitting time and sleep duration are associated with an increased risk of metabolic syndrome components, including central obesity and high triglycerides, glucose, and diastolic blood pressure. This study could provide information for future investigation into these associations. Also, recommendations are

  9. Association of physical activity with metabolic syndrome in a predominantly rural Nigerian population

    DEFF Research Database (Denmark)

    Oguoma, Victor M.; Nwose, Ezekiel U.; Nwose, Ezekiel U.

    2016-01-01

    Aims Physical activity is an essential determinant of health. However, there is dearth of evidence regarding prevalence of physical activity in developing countries, especially its association with metabolic syndrome risk factors. This study assessed the association of physical activity...... with metabolic syndrome in a Nigerian population. Materials and methods A cross-sectional study was carried out on apparently healthy persons who are ≥18 years old. The World Health Organisation (WHO) Global Physical Activity Questionnaire (GPAQ) was used to collect five domains of physical activity....... Participants were classified as physically active or inactive based on meeting the cut-off value of 600 MET-min/week. Metabolic syndrome was diagnosed using the Joint Scientific Statement on Harmonizing the Metabolic Syndrome criteria. Results Overall prevalence of physically active individuals was 50.1% (CI...

  10. Modelling subglacial drainage and its role in ice-ocean interaction

    Science.gov (United States)

    Hewitt, Ian; Dallaston, Michael; Wells, Andrew

    2015-04-01

    Melting at the ice-ocean interface, both beneath ice shelves and at near-vertical tidewater margins, is strongly influenced by discharge of meltwater from beneath the grounded ice. The fresh water source can help to initiate a buoyant plume that rises up the ice face, entraining heat from the ocean to melt the ice. When the subglacial discharge is spatially and temporally variable, it can cause spatial and temporal variations in the melting rate, which in turn may influence ocean circulation in the cavity and ice flow within the shelf. Recent observations of channelized ice shelf bases may have their origin in variable subglacial discharge from beneath the grounded ice. In this work, we use physically-based models of the subglacial drainage system to examine the likely mode of melt water delivery across the grounding line. We find that if subglacial channels (Rothlisberger channels) exist they can be expected to `trumpet' out as the ocean is approached, due to a lack of confining stress to counteract wall melting. This causes a reduction in horizontal momentum in the water and can lead to pronounced localized melting around channel termini. This may lead to increased propensity for calving at such locations. We also examine the effect of subglacial discharge variations on the evolution of a downstream floating ice shelf. We find that lateral variations in the flow across the grounding line can result in variations in plume-driven melting which evolve to create basal channels in the shelf aligned with the flow. The preferred spacing of the channels is controlled by a balance between buoyancy-driven acceleration and turbulent mixing in the ocean layer.

  11. Recharge of a subglacial lake by surface meltwater in northeast Greenland.

    Science.gov (United States)

    Willis, Michael J; Herried, Bradley G; Bevis, Michael G; Bell, Robin E

    2015-02-12

    In a warming climate, surface meltwater production on large ice sheets is expected to increase. If this water is delivered to the ice sheet base it may have important consequences for ice dynamics. For example, basal water distributed in a diffuse network can decrease basal friction and accelerate ice flow, whereas channelized basal water can move quickly to the ice margin, where it can alter fjord circulation and submarine melt rates. Less certain is whether surface meltwater can be trapped and stored in subglacial lakes beneath large ice sheets. Here we show that a subglacial lake in Greenland drained quickly, as seen in the collapse of the ice surface, and then refilled from surface meltwater input. We use digital elevation models from stereo satellite imagery and airborne measurements to resolve elevation changes during the evolution of the surface and basal hydrologic systems at the Flade Isblink ice cap in northeast Greenland. During the autumn of 2011, a collapse basin about 70 metres deep and about 0.4 cubic kilometres in volume formed near the southern summit of the ice cap as a subglacial lake drained into a nearby fjord. Over the next two years, rapid uplift of the floor of the basin (which is approximately 8.4 square kilometres in area) occurred as surface meltwater flowed into crevasses around the basin margin and refilled the subglacial lake. Our observations show that surface meltwater can be trapped and stored at the bed of an ice sheet. Sensible and latent heat released by this trapped meltwater could soften nearby colder basal ice and alter downstream ice dynamics. Heat transport associated with meltwater trapped in subglacial lakes should be considered when predicting how ice sheet behaviour will change in a warming climate.

  12. The Individual, Joint, and Additive Interaction Associations of Aerobic-Based Physical Activity and Muscle Strengthening Activities on Metabolic Syndrome.

    Science.gov (United States)

    Dankel, Scott J; Loenneke, Jeremy P; Loprinzi, Paul D

    2016-12-01

    Previous research has demonstrated that physical activity and muscle strengthening activities are independently and inversely associated with metabolic syndrome. Despite a number of studies examining the individual associations, only a few studies have examined the joint associations, and to our knowledge, no previous studies have examined the potential additive interaction of performing muscle strengthening activities and aerobic-based physical activity and their association with metabolic syndrome. Using data from the 2003 to 2006 National Health and Nutrition Examination Survey (NHANES), we computed three separate multivariable logistic regression models to examine the individual, combined, and additive interaction of meeting guidelines for accelerometer-assessed physical activity and self-reported muscle strengthening activities, and their association with metabolic syndrome. We found that individuals meeting physical activity and muscle strengthening activity guidelines, respectively, were at 61 and 25 % lower odds of having metabolic syndrome. Furthermore, individuals meeting both guidelines had the lowest odds of having metabolic syndrome (70 %), in part due to the additive interaction of performing both modes of exercise. In this national sample, accelerometer-assessed physical activity and muscle strengthening activities were synergistically associated with metabolic syndrome.

  13. An in vitro model for screening estrogen activity of environmental samples after metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Chahbane, N.; Schramm, K.W. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Oekologische Chemie; Kettrup, A. [Technische Univ. Muenchen, Freising (Germany). Lehrstuhl fuer Oekologische Chemie

    2004-09-15

    For a few years, yeast estrogen assay (YES) was accepted as a reliable and economic model for screening of environmental estrogens. Though the chemicals directly act with estrogen receptor (ER) can be filtered out by this model, there are still chemicals act with ER only after metabolism and some chemicals eliminate their estrogen activities after metabolism. That is to say, their metabolites exert or have stronger estrogen activities than themselves, which can be called bio-activation. In this case, for the lack of the metabolism enzyme system as human and other animals, only the assay with recombinant yeast cells is insufficient. So, it is necessary to combine the YES with metabolism procedure to evaluate the estrogen activities of these chemicals. The most common method used currently for in vitro metabolic activation in mutagenicity testing and also be applied to the estrogen screening field is S-9 mixture. Also, there is an attempt to develop a chemical model for cytochrome P450 as a bio-mimetic metabolic activation system. All these methods can be used as in vitro models for metabolism. Compare with these models, using whole H4II E cells for metabolism is an alternative and with superiorities. It has the excellence of short experiment period as all other in vitro models, but is much more close to the real surroundings as in vivo. Furthermore, the activity of 7-ethoxyresorufin-O-deethylase (EROD) can be easily measured during the whole incubation period for us to discuss the metabolic activities in a quantitative foundation, not only in qualitative. Methoxychlor is one of the chemicals with bio-activation ability. When directly used in the YES, it shows weak estrogen activity. But a main metabolite of methoxychlor, 2,2-bis (p-hydroxyphenyl) - 1,1,1-trichloroethane (HPTE) is a known estrogen mimic. For the long time using methoxychlor as a pesticide and its clear background, it is an ideal chemical to establish this in vitro system.

  14. The Wilkes subglacial basin eastern margin electrical conductivity anomaly

    Science.gov (United States)

    Rizzello, Daniele; Armadillo, Egidio; Ferraccioli, Fausto; Caneva, Giorgio

    2014-05-01

    We have analyzed the deep conductivity structure at the transition between the Transantarctic Mountains (TAM) and the eastern margin of the WSB in NVL, by means of the GDS (Geomagnetic Deep Sounding) technique, in order to constrain the geodynamical interpretation of this antarctic sector. The TAM form the uplifted flank of the Mesozoic and Cenozoic West Antarctic Rift System. Structure of the TAM rift flank has been partially investigated with different geophysical approaches.The Wilkes Subglacial Basin is a broad depression over 400 km wide at the George V Coast and 1200 km long. Geology, lithospheric structure and tectonics of the Basin are only partially known because the Basin is buried beneath the East Antarctic Ice Sheet and is located in a remote region which makes geophysical exploration logistically challenging. Different authors have proposed contrasting hypothesis regarding the origin of the WSB: it could represent a region of rifted continental crust, or it may have a flexural origin or might represent an "extended terrane". Recently aerogeophysical investigations have demonstrated a strong structural control on the margin. Magnetovariational studies carried out at high geomagnetic latitudes are often hampered by source effects, mainly due to the closeness to the Polar Electrojet currents systems (PEJ). Its presence, in fact, makes the uniform magnetic field assumption, on which the magnetovariational methods are based on, often invalid, which outcome is a bias in the GDS transfer functions and to compromise the reliability of the inverted models. Data from the aforementioned campaigns have been then processed under the ISEE project (Ice Sheet Electromagnetic Experiment), aimed at evaluate and mitigate the bias effect of the PEJ on geomagnetic an magnetotelluric transfer functions at high geomagnetic latitudes, by means of suitable processing algorithms, developed upon a statistical analysis study on PEJ effects (Rizzello et al. 2013). Recent results

  15. The metabolically active subpopulation in Pseudomonas aeruginosa biofilms survives exposure to membrane-targeting antimicrobials via distinct molecular mechanisms

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Pamp, Sünje Johanna; Nilsson, Martin

    2012-01-01

    Biofilms are reported to be inherently refractory toward antimicrobial attack and, therefore, cause problems in industrial and medical settings. Pseudomonas aeruginosa biofilms contain subpopulations that exhibit high metabolic activity and subpopulations that exhibit low metabolic activity. We h...

  16. Physical activity and sedentary behavior in metabolically healthy obese young women

    Science.gov (United States)

    Studies of physical activity (PA) and sedentary behavior (SB) in metabolically healthy obese (MHO) have been limited to postmenopausal white women. We sought to determine whether PA and SB differ between MHO and metabolically abnormal obese (MAO), in young black and white women....

  17. Dietary patterns as compared with physical activity in relation to metabolic syndrome among Chinese adults

    NARCIS (Netherlands)

    He, Y.; Li, Y.; Lai, J.; Wang, D.; Zhang, J.; Fu, P.; Yang, X.; Qi, L.

    2013-01-01

    Aims: To examine the nationally-representative dietary patterns and their joint effects with physical activity on the likelihood of metabolic syndrome (MS) among 20,827 Chinese adults. Methods and results: CNNHS was a nationally representative cross-sectional observational study. Metabolic syndrome

  18. Effects of Cola-Flavored Beverages and Caffeine on Streptococcus mutans Biofilm Formation and Metabolic Activity.

    Science.gov (United States)

    Dotsey, Roger P; Moser, Elizabeth A S; Eckert, George J; Gregory, Richard L

    To examine the effects of cola-flavored beverages and caffeine on growth and metabolism of Streptococcus mutans biofilm. This study was designed to determine if carbonated beverages or caffeine can increase S. mutans growth and biofilm formation and metabolic activity in vitro, potentially leading to increased S. mutans-associated cariogenicity in children that consume them. Six different cola-flavored products, plus pure caffeine, and pure high fructose corn syrup (HFCS), at different concentrations similar to those in the beverages were tested. A 16-hour culture of S. mutans was treated with different dilutions in bacteriological media. To test for the effect on biofilm formation, the biofilm was stained with crystal violet. The absorbance was determined to evaluate biofilm growth. Biofilm metabolic activity was measured based on biofilm having the ability to reduce XTT to a water-soluble orange compound. The inclusion of HFCS in the beverages, as well as pure HFCS, significantly enhanced bacterial biofilm formation and metabolic activity. Pure caffeine and the presence of caffeine in beverages did not significantly increase biofilm formation, but pure caffeine significantly increased metabolism, and Diet Coke had significantly greater metabolic activity than Caffeine-Free Diet Coke. HFCS increases both the biofilm formation and metabolism of S. mutans, and caffeine in some cases increases metabolism of S. mutans.

  19. The Rab-GTPase-activating protein TBC1D1 regulates skeletal muscle glucose metabolism

    DEFF Research Database (Denmark)

    Szekeres, Ferenc; Chadt, Alexandra; Tom, Robby Z

    2012-01-01

    The Rab-GTPase-activating protein TBC1D1 has emerged as a novel candidate involved in metabolic regulation. Our aim was to determine whether TBC1D1 is involved in insulin as well as energy-sensing signals controlling skeletal muscle metabolism. TBC1D1-deficient congenic B6.SJL-Nob1.10 (Nob1.10(SJ...

  20. DISTURBANCE OF METABOLIC ACTIVITY OF INTESTINAL MICROFLORA AND LOCAL IMMUNITY OF ROTAVIRUS INFECTION

    Directory of Open Access Journals (Sweden)

    G. P. Martynova

    2014-01-01

    Full Text Available The paper describes the research on metabolic activity of intestinal microflora and secretory immunoglobulin A (sIgA content in coprofiltrate of rotavirus infection patients depending on disease course. It is established that a long-lasting clinical oppression of metabolic processes of microbiocenosis and local immunity deficiency define a rough course of rotavirus infection. 

  1. DISTURBANCE OF METABOLIC ACTIVITY OF INTESTINAL MICROFLORA AND LOCAL IMMUNITY OF ROTAVIRUS INFECTION

    OpenAIRE

    G. P. Martynova; N. V. Kogan; I. A. Solovyeva

    2014-01-01

    The paper describes the research on metabolic activity of intestinal microflora and secretory immunoglobulin A (sIgA) content in coprofiltrate of rotavirus infection patients depending on disease course. It is established that a long-lasting clinical oppression of metabolic processes of microbiocenosis and local immunity deficiency define a rough course of rotavirus infection. 

  2. Rho-kinase inhibition ameliorates metabolic disorders through activation of AMPK pathway in mice.

    Directory of Open Access Journals (Sweden)

    Kazuki Noda

    Full Text Available BACKGROUND: Metabolic disorders, caused by excessive calorie intake and low physical activity, are important cardiovascular risk factors. Rho-kinase, an effector protein of the small GTP-binding protein RhoA, is an important cardiovascular therapeutic target and its activity is increased in patients with metabolic syndrome. We aimed to examine whether Rho-kinase inhibition improves high-fat diet (HFD-induced metabolic disorders, and if so, to elucidate the involvement of AMP-activated kinase (AMPK, a key molecule of metabolic conditions. METHODS AND RESULTS: Mice were fed a high-fat diet, which induced metabolic phenotypes, such as obesity, hypercholesterolemia and glucose intolerance. These phenotypes are suppressed by treatment with selective Rho-kinase inhibitor, associated with increased whole body O2 consumption and AMPK activation in the skeletal muscle and liver. Moreover, Rho-kinase inhibition increased mRNA expression of the molecules linked to fatty acid oxidation, mitochondrial energy production and glucose metabolism, all of which are known as targets of AMPK in those tissues. In systemic overexpression of dominant-negative Rho-kinase mice, body weight, serum lipid levels and glucose metabolism were improved compared with littermate control mice. Furthermore, in AMPKα2-deficient mice, the beneficial effects of fasudil, a Rho-kinase inhibitor, on body weight, hypercholesterolemia, mRNA expression of the AMPK targets and increase of whole body O2 consumption were absent, whereas glucose metabolism was restored by fasudil to the level in wild-type mice. In cultured mouse myocytes, pharmacological and genetic inhibition of Rho-kinase increased AMPK activity through liver kinase b1 (LKB1, with up-regulation of its targets, which effects were abolished by an AMPK inhibitor, compound C. CONCLUSIONS: These results indicate that Rho-kinase inhibition ameliorates metabolic disorders through activation of the LKB1/AMPK pathway, suggesting that

  3. Seasonal metabolic changes in a year-round reproductively active subtropical tree-frog (Hypsiboas prasinus).

    Science.gov (United States)

    Kiss, Ana Carolina I; de Carvalho, José Eduardo; Navas, Carlos A; Gomes, Fernando R

    2009-02-01

    Although seasonal metabolic variation in ectothermic tetrapods has been investigated primarily in the context of species showing some level of metabolic depression during winter, but several species of anurans maintain their activity patterns throughout the year in tropical and subtropical areas. The tree-frog Hypsiboas prasinus occurs in the subtropical Atlantic Forest and remains reproductively active during winter, at temperatures below 10 degrees C. We compared males calling in summer and winter, and found that males of H. prasinus exhibit seasonal adjustments in metabolic and morphometric variables. Individuals calling during winter were larger and showed higher resting metabolic rates than those calling during summer. Calling rates were not affected by season. Winter animals showed lower liver and heart activity level of citrate synthase (CS), partially compensated by larger liver mass. Winter individuals also showed higher activity of pyruvate kinase (PK) and lower activity of CS in trunk muscles, and higher activity of CS in leg muscles. Winter metabolic adjustments seem to be achieved by both compensatory mechanisms to the lower environmental temperature and a seasonally oriented aerobic depression of several organs. The impact of seasonal metabolic changes on calling performance and the capacity of subtropical anurans for metabolic thermal acclimatization are also discussed.

  4. Metabolic Costs of Daily Activities in Community-Dwelling Older Adults

    Directory of Open Access Journals (Sweden)

    Sin-Ae Park

    2014-12-01

    Full Text Available This study was conducted to measure the metabolic costs of daily activities in community-dwelling adults aged over 65 years. Eighteen elderly adults performed five daily activities—walking, cleaning with a vacuum cleaner, washing dishes, and gardening (making a vegetable bed and maintaining a garden—in a laboratory setting. The participants performed each activity for 5 minutes and then rested in a chair for 5 minutes prior to starting the next activity. They wore a portable telemetric calorimeter and a heart rate monitor during the five activities and resting periods to measure the metabolic cost and heart rate. The five daily activities were observed to be of low to moderate intensity (from 2.3 ± 0.5 metabolic equivalents to 4.6 ± 0.5 metabolic equivalents.

  5. Fibroblast activation protein (FAP as a novel metabolic target

    Directory of Open Access Journals (Sweden)

    Miguel Angel Sánchez-Garrido

    2016-10-01

    Conclusions: We conclude that pharmacological inhibition of FAP enhances levels of FGF21 in obese mice to provide robust metabolic benefits not observed in lean animals, thus validating this enzyme as a novel drug target for the treatment of obesity and diabetes.

  6. Quantifying interictal metabolic activity in human temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Henry, T.R.; Mazziotta, J.C.; Engel, J. Jr.; Christenson, P.D.; Zhang, J.X.; Phelps, M.E.; Kuhl, D.E. (Univ. of California, Los Angeles (USA))

    1990-09-01

    The majority of patients with complex partial seizures of unilateral temporal lobe origin have interictal temporal hypometabolism on (18F)fluorodeoxyglucose positron emission tomography (FDG PET) studies. Often, this hypometabolism extends to ipsilateral extratemporal sites. The use of accurately quantified metabolic data has been limited by the absence of an equally reliable method of anatomical analysis of PET images. We developed a standardized method for visual placement of anatomically configured regions of interest on FDG PET studies, which is particularly adapted to the widespread, asymmetric, and often severe interictal metabolic alterations of temporal lobe epilepsy. This method was applied by a single investigator, who was blind to the identity of subjects, to 10 normal control and 25 interictal temporal lobe epilepsy studies. All subjects had normal brain anatomical volumes on structural neuroimaging studies. The results demonstrate ipsilateral thalamic and temporal lobe involvement in the interictal hypometabolism of unilateral temporal lobe epilepsy. Ipsilateral frontal, parietal, and basal ganglial metabolism is also reduced, although not as markedly as is temporal and thalamic metabolism.

  7. The influence of physical activity on components of metabolic ...

    African Journals Online (AJOL)

    Inactivity causes obesity which is related to insulin resistance, hypertension, diabetes mellitus, dyslipidemia, poor vascular health and the metabolic syndrome (MS). The MS has recently been observed in youth, and if left untreated can lead to cardiovascular diseases. The aim of this research was to determine the influence ...

  8. Relevance of Sympathetic Nervous System Activation in Obesity and Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia A. Thorp

    2015-01-01

    Full Text Available Sympathetic tone is well recognised as being implicit in cardiovascular control. It is less readily acknowledged that activation of the sympathetic nervous system is integral in energy homeostasis and can exert profound metabolic effects. Accumulating data from animal and human studies suggest that central sympathetic overactivity plays a pivotal role in the aetiology and complications of several metabolic conditions that can cluster to form the Metabolic Syndrome (MetS. Given the known augmented risk for type 2 diabetes, cardiovascular disease, and premature mortality associated with the MetS understanding the complex pathways underlying the metabolic derangements involved has become a priority. Many factors have been proposed to contribute to increased sympathetic nerve activity in metabolic abnormalities including obesity, impaired baroreflex sensitivity, hyperinsulinemia, and elevated adipokine levels. Furthermore there is mounting evidence to suggest that chronic sympathetic overactivity can potentiate two of the key metabolic alterations of the MetS, central obesity and insulin resistance. This review will discuss the regulatory role of the sympathetic nervous system in metabolic control and the proposed pathophysiology linking sympathetic overactivity to metabolic abnormalities. Pharmacological and device-based approaches that target central sympathetic drive will also be discussed as possible therapeutic options to improve metabolic control in at-risk patient cohorts.

  9. Global Catalogue of the Martian Valley Networks: Evidences for Fluvial, Sapping and Subglacial Processes on Early Mars

    Science.gov (United States)

    Grau Galofre, A.; Jellinek, A. M.

    2017-10-01

    We use erosion models and statistical morphometry schemes to show quantitative evidence for fluvial, glacial, groundwater sapping and subglacial erosion on the Noachian highlands, to then build a global map of valley network origin and distribution.

  10. Quantification of metabolically active transient storage (MATS) in two reaches with contrasting transient storage and ecosystem respiration

    Science.gov (United States)

    Alba Argerich; Roy Haggerty; Eugènia Martí; Francesc Sabater; Jay. Zarnetske

    2011-01-01

    Water transient storage zones are hotspots for metabolic activity in streams although the contribution of different types of transient storage zones to the whole�]reach metabolic activity is difficult to quantify. In this study we present a method to measure the fraction of the transient storage that is metabolically active (MATS) in two consecutive reaches...

  11. Association of Objectively Measured Physical Activity and Metabolic Syndrome Among US Adults With Osteoarthritis.

    Science.gov (United States)

    Liu, Shao-Hsien; Waring, Molly E; Eaton, Charles B; Lapane, Kate L

    2015-10-01

    To investigate the association between objectively measured physical activity and metabolic syndrome among adults with osteoarthritis (OA). Using cross-sectional data from the 2003-2006 National Health and Nutrition Examination Survey, we identified 566 adults with OA with available accelerometer data assessed using Actigraph AM-7164 and measurements necessary to determine metabolic syndrome by the Adult Treatment Panel III. Analysis of variance was conducted to examine the association between continuous variables in each activity level and metabolic syndrome components. Logistic models estimated the relationship of quartile of daily minutes of different physical activity levels to odds of metabolic syndrome adjusted for socioeconomic and health factors. Among persons with OA, most were women average age of 62.1 years and average disease duration of 12.9 years. Half of adults with OA had metabolic syndrome (51.0%; 95% confidence interval [95% CI] 44.2%-57.8%), and only 9.6% engaged in the recommended 150 minutes per week of moderate/vigorous physical activity. Total sedentary time was associated with higher rates of metabolic syndrome and its components, while light and objectively measured moderate/vigorous physical activity was inversely associated with metabolic syndrome and its components. Higher levels of light activity were associated with lower prevalence of metabolic syndrome (quartile 4 versus quartile 1: adjusted odds ratio 0.45, 95% CI 0.24-0.84, P for linear trend physical activity, especially in light intensity, is more likely to be associated with decreasing prevalence of metabolic syndrome among persons with OA. © 2015, American College of Rheumatology.

  12. Physical activity is negatively associated with the metabolic syndrome in the elderly.

    Science.gov (United States)

    Bianchi, G; Rossi, V; Muscari, A; Magalotti, D; Zoli, M

    2008-09-01

    An inverse association between physical activity and metabolic syndrome has been reported in several cohorts, but very few specific studies are available in the elderly, in whom neurological and musculo-skeletal diseases are expected to lead to a remarkable age-related decline of physical activity. The relationships among physical activity, insulin resistance and metabolic syndrome were assessed in a cross-sectional study concerning 1144 subjects aged 65-91 years resident in Pianoro (northern Italy). Household and leisure-time activities were assessed by a self-administered questionnaire (Physical Activity Scale for Elderly--PASE). Routine clinical and biochemical data (including fasting insulin) were used to assess insulin resistance [Homeostasis Model Assessment (HOMA) method] and the prevalence of metabolic syndrome. All PASE scores were inversely correlated with waist circumference, triglycerides and HOMA index, with highest significance for leisure-time activities (P activities was also correlated inversely with blood glucose (P metabolic syndrome was more prevalent among sedentary subjects (corresponding to the low tertile of leisure-time activities) than in the remaining more active population (odds ratio 1.51, 95% confidence interval 1.12-2.03, P = 0.007), independently of possible confounders. Physical activity is inversely associated with insulin resistance and the metabolic syndrome even in the elderly. Community programs favoring physical activity are expected to significantly improve the health status in these subjects.

  13. Regulation of hepatic stellate cell proliferation and activation by glutamine metabolism.

    Directory of Open Access Journals (Sweden)

    Jiang Li

    Full Text Available Liver fibrosis is the excessive accumulation of extracellular matrix proteins, which is mainly caused by accumulation of activated hepatic stellate cells (HSCs. The mechanisms of activation and proliferation of HSCs, two key events after liver damage, have been studied for many years. Here we report a novel pathway to control HSCs by regulating glutamine metabolism. We demonstrated that the proliferation of HSCs is critically dependent on glutamine that is used to generate α-ketoglutarate (α-KG and non-essential amino acid (NEAA. In addition, both culture- and in vivo-activated HSCs have increased glutamine utilization and increased expression of genes related to glutamine metabolism, including GLS (glutaminase, aspartate transaminase (GOT1 and glutamate dehydrogenase (GLUD1. Inhibition of these enzymes, as well as glutamine depletion, had a significant inhibitory effect on HSCs activation. In addition to providing energy expenditure, conversion of glutamine to proline is enhanced. The pool of free proline may also be increased via downregulation of POX expression. Hedgehog signaling plays an important role in the regulation of glutamine metabolism, as well as TGF-β1, c-Myc, and Ras signalings, via transcriptional upregulation and repression of key metabolic enzymes in this pathway. Finally, changes in glutamine metabolism were also found in mouse liver tissue following CCl4-induced acute injury.Glutamine metabolism plays an important role in regulating the proliferation and activation of HSCs. Strategies that are targeted at glutamine metabolism may represent a novel therapeutic approach to the treatment of liver fibrosis.

  14. Diet composition and activity level of at risk and metabolically healthy obese American adults.

    Science.gov (United States)

    Hankinson, Arlene L; Daviglus, Martha L; Van Horn, Linda; Chan, Queenie; Brown, Ian; Holmes, Elaine; Elliott, Paul; Stamler, Jeremiah

    2013-03-01

    Obesity often clusters with other major cardiovascular disease risk factors, yet a subset of the obese appears to be protected from these risks. Two obesity phenotypes are described, (i) "metabolically healthy" obese, broadly defined as body mass index (BMI) ≥ 30 kg/m(2) and favorable levels of blood pressure, lipids, and glucose; and (ii) "at risk" obese, BMI ≥ 30 with unfavorable levels of these risk factors. More than 30% of obese American adults are metabolically healthy. Diet and activity determinants of obesity phenotypes are unclear. We hypothesized that metabolically healthy obese have more favorable behavioral factors, including less adverse diet composition and higher activity levels than at risk obese in the multi-ethnic group of 775 obese American adults ages 40-59 years from the International Population Study on Macro/Micronutrients and Blood Pressure (INTERMAP) cohort. In gender-stratified analyses, mean values for diet composition and activity behavior variables, adjusted for age, race, and education, were compared between metabolically healthy and at risk obese. Nearly one in five (149/775 or 19%) of obese American INTERMAP participants were classified as metabolically healthy obese. Diet composition and most activity behaviors were similar between obesity phenotypes, although metabolically healthy obese women reported higher sleep duration than at risk obese women. These results do not support hypotheses that diet composition and/or physical activity account for the absence of cardiometabolic abnormalities in metabolically healthy obese. Copyright © 2012 The Obesity Society.

  15. Natural compounds regulate energy metabolism by the modulating the activity of lipid-sensing nuclear receptors.

    Science.gov (United States)

    Goto, Tsuyoshi; Kim, Young-Il; Takahashi, Nobuyuki; Kawada, Teruo

    2013-01-01

    Obesity causes excess fat accumulation in various tissues, most notoriously in the adipose tissue, along with other insulin-responsive organs such as skeletal muscle and the liver, which predisposes an individual to the development of metabolic abnormalities. The molecular mechanisms underlying obesity-induced metabolic abnormalities have not been completely elucidated; however, in recent years, the search for therapies to prevent the development of obesity and obesity-associated metabolic disorders has increased. It is known that several nuclear receptors, when activated by specific ligands, regulate carbohydrate and lipid metabolism at the transcriptional level. The expression of lipid metabolism-related enzymes is directly regulated by the activity of various nuclear receptors via their interaction with specific response elements in promoters of those genes. Many natural compounds act as ligands of nuclear receptors and regulate carbohydrate and lipid metabolism by regulating the activities of these nuclear receptors. In this review, we describe our current knowledge of obesity, the role of lipid-sensing nuclear receptors in energy metabolism, and several examples of food factors that act as agonists or antagonists of nuclear receptors, which may be useful for the management of obesity and the accompanying energy metabolism abnormalities. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Effects of petroleum contamination on soil microbial numbers, metabolic activity and urease activity.

    Science.gov (United States)

    Guo, Huan; Yao, Jun; Cai, Minmin; Qian, Yiguang; Guo, Yue; Richnow, Hans H; Blake, Ruth E; Doni, Serena; Ceccanti, Brunello

    2012-06-01

    The influence of petroleum contamination on soil microbial activities was investigated in 13 soil samples from sites around an injection water well (Iw-1, 2, 3, 4) (total petroleum hydrocarbons (TPH): 7.5-78 mg kg(-1)), an oil production well (Op-1, 2, 3, 4, 5) (TPH: 149-1110 mg kg(-1)), and an oil spill accident well (Os-1, 2, 3, 4) (TPH: 4500-34600 mg kg(-1)). The growth rate constant (μ) of glucose stimulated organisms, determined by microcalorimetry, was higher in Iw soil samples than in Op and Os samples. Total cultivable bacteria and fungi and urease activity also decreased with increasing concentration of TPH. Total heat produced demonstrated that TPH at concentrations less than about 1 g kg(-1) soil stimulated anaerobic respiration. A positive correlation between TPH and soil organic matter (OM) and stimulation of fungi-bacteria-urease at low TPH doses suggested that TPH is bound to soil OM and slowly metabolized in Iw soils during OM consumption. These methods can be used to evaluate the potential of polluted soils to carry out self-bioremediation by metabolizing TPH. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Excretion pattern and metabolism of hexachlorobutadiene in rats. Evidence for metabolic activation by conjugation reactions.

    Science.gov (United States)

    Reichert, D; Schütz, S; Metzler, M

    1985-02-15

    Excretion, covalent binding and metabolism of hexachloro-1,3-butadiene (HCBD), a nephrotoxic and nephrocarcinogenic compound, have been studied in female rats. Seventy-two hours after administration of a single oral dose of 1 mg/kg [14C]HCBD, 5.3% of the dose were exhaled as unchanged HCBD and 76.3% were metabolized and excreted in urine and feces or exhaled as 14CO2. After a 50 mg/kg dose of [14C]HCBD, the amount of exhaled parent compound was nearly unchanged at 5.4%. At the higher dose the gastro-intestinal absorption of HCBD appeared to be saturated with the result that unchanged HCBD constituted the major portion of the 69% radioactivity eliminated. Covalent binding to proteins in kidney and liver agreed well with the organ-specific toxicity of HCBD: binding was higher in the kidney, independent of the dose. It increased significantly when the rats were pretreated with phenobarbital, an inducer of monooxygenases; it decreased when the inhibitor piperonyl butoxide was given. Urinary radioactivity in 24 hr urine was separated by column chromatography into four fractions. High performance liquid chromatography, radio gas chromatography and gas chromatography/mass spectrometry were used for further separation and identification. Two major metabolites were identified as pentachlorobutadiene methylthio ether and pentachlorobutadiene carboxymethylthio ether. Their formation is plausibly explained via glutathione conjugation, which appears to be the first step in HCBD metabolism. The mechanism of the conjugation at the olefinic double bond of HCBD is explained by an addition-elimination reaction. This pathway, which appears to lead to a destabilization of the HCBD molecule, could explain the distinct nephrotoxic effects of HCBD.

  18. Effects of total solar eclipse on the behavioural and metabolic activities of tropical intertidal animals

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.; Ansari, Z.A.; Verlecar, X.N.; Harkantra, S.N.

    To study the effects of total solar eclipse of 16th Feb. 1980, on the behaviour and metabolic activities of intertidal invertebrates - nematodes, gastropods and bivalves - having different habitat preference a set of relevant observations, covering...

  19. Effectiveness of physical activity intervention among government employees with metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Chee Huei Phing

    2017-12-01

    Conclusion: The findings of this study suggest that physical activity intervention via aerobics classes is an effective strategy for improving step counts and reducing the prevalence of metabolic syndrome.

  20. Cardiac Autonomic Nervous System Activation and Metabolic Profile in Young Children : The ABCD Study

    NARCIS (Netherlands)

    Vrijkotte, Tanja G M; van den Born, Bert-Jan H; Hoekstra, Christine M C A; Gademan, Maaike G J; van Eijsden, Manon; de Rooij, Susanne R; Twickler, Marcel T B

    2015-01-01

    BACKGROUND: In adults, increased sympathetic and decreased parasympathetic nervous system activity are associated with a less favorable metabolic profile. Whether this is already determined at early age is unknown. Therefore, we aimed to assess the association between autonomic nervous system

  1. Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster

    OpenAIRE

    Baenas, Nieves; Piegholdt, Stefanie; Schloesser, Anke; Moreno, Diego A.; García-Viguera, Cristina; Rimbach, Gerald; Wagner, Anika E.

    2016-01-01

    We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo), a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L) for 10 days, containing high amounts of glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforap...

  2. Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster

    Science.gov (United States)

    Baenas, Nieves; Piegholdt, Stefanie; Schloesser, Anke; Moreno, Diego A.; García-Viguera, Cristina; Rimbach, Gerald; Wagner, Anika E.

    2016-01-01

    We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo), a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L) for 10 days, containing high amounts of glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforaphene and raphasatin, respectively. We demonstrate that Drosophila melanogaster takes up and metabolizes isothiocyanates from radish sprouts through the detection of the metabolite sulforaphane-cysteine in fly homogenates. Moreover, we report a decrease in the glucose content of flies, an upregulation of spargel expression, the Drosophila homolog of the mammalian PPARγ-coactivator 1 α, as well as the inhibition of α-amylase and α-glucosidase in vitro. Overall, we show that the consumption of radish sprouts affects energy metabolism in Drosophila melanogaster which is reflected by lower glucose levels and an increased expression of spargel, a central player in mitochondrial biogenesis. These processes are often affected in chronic diseases associated with aging, including type II diabetes mellitus. PMID:26901196

  3. Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster.

    Science.gov (United States)

    Baenas, Nieves; Piegholdt, Stefanie; Schloesser, Anke; Moreno, Diego A; García-Viguera, Cristina; Rimbach, Gerald; Wagner, Anika E

    2016-02-18

    We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo), a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L) for 10 days, containing high amounts of glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforaphene and raphasatin, respectively. We demonstrate that Drosophila melanogaster takes up and metabolizes isothiocyanates from radish sprouts through the detection of the metabolite sulforaphane-cysteine in fly homogenates. Moreover, we report a decrease in the glucose content of flies, an upregulation of spargel expression, the Drosophila homolog of the mammalian PPARγ-coactivator 1 α, as well as the inhibition of α-amylase and α-glucosidase in vitro. Overall, we show that the consumption of radish sprouts affects energy metabolism in Drosophila melanogaster which is reflected by lower glucose levels and an increased expression of spargel, a central player in mitochondrial biogenesis. These processes are often affected in chronic diseases associated with aging, including type II diabetes mellitus.

  4. Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Nieves Baenas

    2016-02-01

    Full Text Available We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo, a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L for 10 days, containing high amounts of glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforaphene and raphasatin, respectively. We demonstrate that Drosophila melanogaster takes up and metabolizes isothiocyanates from radish sprouts through the detection of the metabolite sulforaphane-cysteine in fly homogenates. Moreover, we report a decrease in the glucose content of flies, an upregulation of spargel expression, the Drosophila homolog of the mammalian PPARγ-coactivator 1 α, as well as the inhibition of α-amylase and α-glucosidase in vitro. Overall, we show that the consumption of radish sprouts affects energy metabolism in Drosophila melanogaster which is reflected by lower glucose levels and an increased expression of spargel, a central player in mitochondrial biogenesis. These processes are often affected in chronic diseases associated with aging, including type II diabetes mellitus.

  5. Metabolic activity of subseafloor microbes in the South Pacific Gyre

    Science.gov (United States)

    Morono, Y.; Ito, M.; Terada, T.; Inagaki, F.

    2013-12-01

    The South Pacific Gyre (SPG) is characterized as the most oligotrophic open ocean environment. The sediment is rich in oxygen but poor in energy-sources such as reduced organic matter, and hence harbors very low numbers of microbial cells in relatively shallow subseafloor sediment (D'Hondt et al., 2009; Kallmeyer et al., 2012). In such an energy-limited sedimentary habitat, a small size of microbial community persists living functions with extraordinary low oxygen-consumption rate (Røy et al., 2012). During IODP Expedition 329, a series of sediment samples were successfully recovered from 7 drill sites (U1365-1371) from the seafloor to basement in the SPG, providing an unprecedented opportunity to study metabolic activity of the aerobic subseafloor microbial communities. We initiated incubation onboard by adding stable isotope-labeled substrates to the freshly collected sediment sample, such as 13C and/or 15N-labeled bicarbonate, glucose, amino acids, acetate, and ammonium under the (micro-) aerobic condition. One of the technological challenges in this study is to harvest microbial cells from very low-biomass sediment samples for the analysis using nano-scale secondary ion mass spectrometry (NanoSIMS). To address the technical issue, we improved existing cell separation technique for the SPG sediment samples with small inorganic zeolitic grains. By monitoring cell recovery rates through an image-based cell enumeration technique (Morono et al., 2009), we found that cell recovery rates in the SPG sediment samples are generally lower than those in other oceanographic settings (i.e., organic-rich ocean margin sediments). To gain higher cell recovery ratio, we applied multiple density gradient layers, resulting in the cell recovery ratio up to around 80-95% (Morono et al., in press). Then, using the newly developed cell separation technique, we successfully sorted enough number of microbial cells in small spots on the membrane (i.e., 103 to 105 cells per spot). Nano

  6. Prevalence of metabolic syndrome and its relationship with physical activity in suburban Beijing, China.

    Science.gov (United States)

    Zhang, Wei-Hong; Xue, Peng; Yao, Meng-Ying; Chang, Hai-Min; Wu, Yan; Zhang, Lei

    2013-01-01

    The present study aimed to estimate the up-to-date prevalence of metabolic syndrome and its relationship with physical activity among suburban adults in Beijing, China. A cross-sectional survey in a representative sample of 19,003 suburban adults aged 18-76 years was carried out in 2007-2008. Data was collected via questionnaires and blood pressure, anthropometric, and laboratory measurements. Of the residents aged 18-76 years in suburban Beijing, 25.9% (27.3% in men and 25.1% in women), 21.3% (19.4% in men and 22.9% in women), and 25.3% (24.2% in men and 26.1% in women) had 1 component, 2 components, and 3 or more components of metabolic syndrome, respectively. The age-standardized prevalence of metabolic syndrome and its components, including abdominal obesity, elevated triglycerides, reduced high-density lipoprotein cholesterol, elevated blood pressure, and elevated fasting plasma glucose, decreased across categories with increasing physical activity. After adjusting for age, sex, education level, smoking, and alcohol consumption, residents were more likely to have metabolic syndrome across categories with decreasing physical activity; a similar relationship also applied to components of metabolic syndrome. A high prevalence of metabolic syndrome and its components is commonly present in suburban Beijing. Increasing physical activity can reduce the relative risk of metabolic syndrome and it components.

  7. In Vitro Effects of Sports and Energy Drinks on Streptococcus mutans Biofilm Formation and Metabolic Activity.

    Science.gov (United States)

    Vinson, LaQuia A; Goodlett, Amy K; Huang, Ruijie; Eckert, George J; Gregory, Richard L

    2017-09-15

    Sports and energy drinks are being increasingly consumed and contain large amounts of sugars, which are known to increase Streptococcus mutans biofilm formation and metabolic activity. The purpose of this in vitro study was to investigate the effects of sports and energy drinks on S. mutans biofilm formation and metabolic activity. S. mutans UA159 was cultured with and without a dilution (1:3 ratio) of a variety of sports and energy drinks in bacterial media for 24 hours. The biofilm was washed, fixed, and stained. Biofilm growth was evaluated by reading absorbance of the crystal violet. Biofilm metabolic activity was measured by the biofilm-reducing XTT to a water-soluble orange compound. Gatorade Protein Recovery Shake and Starbucks Doubleshot Espresso Energy were found to significantly increase biofilm (30-fold and 22-fold, respectively) and metabolic activity (2-fold and 3-fold, respectively). However, most of the remaining drinks significantly inhibited biofilm growth and metabolic activity. Several sports and energy drinks, with sugars or sugar substitutes as their main ingredients inhibited S. mutans biofilm formation. Among the drinks evaluated, Gatorade Protein Recovery Chocolate Shake and Starbucks Doubleshot Energy appear to have cariogenic potential since they increased the biofilm formation and metabolic activity of S. mutans.

  8. Interrelationships among physical activity, depression, homocysteine, and metabolic syndrome with special considerations by sex.

    Science.gov (United States)

    Loprinzi, Paul D; Cardinal, Bradley J

    2012-06-01

    Examine the interrelationships among physical activity, depression, homocysteine and metabolic syndrome, and to examine the association between physical activity and the simultaneous presence of metabolic syndrome, depression, and high homocysteine. Data from the 2005-2006 National Health and Nutrition Examination Survey were used. 1146 participants were included in the analyses. Physical activity was objectively measured using accelerometry. With respect to the association between physical activity and the simultaneous presence of these three co-morbidities, women, compared to men, had a greater strength of association. For women, compared to those participants not having metabolic syndrome or at least mild depression or high homocysteine (reference groups), the odds ratio values for participants with 1) only depression, 2) only metabolic syndrome, 3) only high homocysteine, 4) metabolic syndrome and mild depression, and 5) metabolic syndrome, mild depression and high homocysteine, respectively, were 0.74 (95% confidence interval: 0.57-0.96, 0.77 (95% confidence interval: 0.61-0.97), 1.08 (95% confidence interval: 0.66-1.76), 0.43 (95% confidence interval: 0.32-0.58), and 0.15 (95% confidence interval: 0.05-0.44), respectively. Promotion of physical activity in the adult population, especially among women, who were found to be less moderately- to vigorously-physically active than their male counterparts, may play an important role in reducing these deleterious conditions. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Examination of myeloperoxidase activity, as an indicator of inflammation in obese participants with metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Matić Tamara

    2016-01-01

    Full Text Available Introduction. Obesity is a complex metabolic disorder and one of the most common modern health problems. Numerous studies indicate association between chronic low-grade inflammatory state and obesity. Myeloperoxidase (MPO and its reactive oxidants participate in tissue damage in the course of inflammatory processes. The aim of this study was to examine MPO activity in the serum of obese participants with metabolic syndrome and its relationship with other indicators of inflammation. Material and Methods: Participants were divided into three groups according to the anthropometric parameters and biochemical indicators: normally fed ones (n=30, participants with abdominal obesity (n = 30 and participants with metabolic syndrome (n = 30. In the serum of patients was being determined chlorination activity of MPO by spectrophotometry. Results: Significant differences were found in MPO activity in all three groups of participants such as: the maximum activity was measured in patients with metabolic syndrome (p <0.001. There was a positive correlation between MPO activity and atherogenic index, as well as between the MPO and the concentration of LDL-cholesterol, while the negative correlation was found between MPO and the concentration of HDL-cholesterol. Conclusion: The examination has shown that the activity of MPO progressively increases with obesity and metabolic syndrome. The obtained results suggest that MPO can be of great importance for the pathophysiological mechanisms leading to the development of complications of obesity and metabolic syndrome.

  10. Associations of physical activity and sitting time with the metabolic syndrome among Omani adults.

    Science.gov (United States)

    Mabry, Ruth M; Winkler, Elisabeth A H; Reeves, Marina M; Eakin, Elizabeth G; Owen, Neville

    2012-11-01

    Most findings on associations of physical activity and sedentary behavior with the metabolic syndrome are from developed countries; thus, we examined these relationships in adults from Sur, Oman. The Sur Healthy Lifestyle Survey (n = 1,335) used the World Health Organization (WHO) Stepwise methodology to assess chronic disease risk factors. Odds ratios for the metabolic syndrome were estimated using logistic regression models for domains of physical activity (work, transport, and leisure) and sitting time, and adjusted for confounding variables. Compared to their counterparts doing the least physical activity, lower odds of the metabolic syndrome were observed among those with higher work activity (0.60; 95% confidence interval (CI): 0.45, 0.80) and transport activity (0.69; 95% CI: 0.47, 1.00), but not leisure activity (0.91; 95% CI: 0.64, 1.32). Odds of the metabolic syndrome were higher in those who sat for ≥ 6 h daily compared to physical activity. This is the first evidence from the Arabian Gulf on associations of physical activity and sitting time with the metabolic syndrome and provides empirical evidence to inform national physical activity guidelines, policies and programs.

  11. Bioorthogonal chemical imaging of metabolic activities in live mammalian hippocampal tissues with stimulated Raman scattering

    Science.gov (United States)

    Hu, Fanghao; Lamprecht, Michael R.; Wei, Lu; Morrison, Barclay; Min, Wei

    2016-12-01

    Brain is an immensely complex system displaying dynamic and heterogeneous metabolic activities. Visualizing cellular metabolism of nucleic acids, proteins, and lipids in brain with chemical specificity has been a long-standing challenge. Recent development in metabolic labeling of small biomolecules allows the study of these metabolisms at the global level. However, these techniques generally require nonphysiological sample preparation for either destructive mass spectrometry imaging or secondary labeling with relatively bulky fluorescent labels. In this study, we have demonstrated bioorthogonal chemical imaging of DNA, RNA, protein and lipid metabolism in live rat brain hippocampal tissues by coupling stimulated Raman scattering microscopy with integrated deuterium and alkyne labeling. Heterogeneous metabolic incorporations for different molecular species and neurogenesis with newly-incorporated DNA were observed in the dentate gyrus of hippocampus at the single cell level. We further applied this platform to study metabolic responses to traumatic brain injury in hippocampal slice cultures, and observed marked upregulation of protein and lipid metabolism particularly in the hilus region of the hippocampus within days of mechanical injury. Thus, our method paves the way for the study of complex metabolic profiles in live brain tissue under both physiological and pathological conditions with single-cell resolution and minimal perturbation.

  12. A new and highly sensitive method of analyzing metabolic activity using FLIM (Conference Presentation)

    Science.gov (United States)

    Evers, Michael; Salma, Nunciada; Birngruber, Reginald; Evans, Conor L.; Manstein, Dieter

    2017-02-01

    Traditional assessments of cellular metabolism are often destructive, time consuming and without visual information. Fluorescence lifetime imaging microscopy (FLIM) provides a highly sensitive, non-invasive, and label-free alternative. This study uses FLIM in combination with two-photon microscopy to investigate pharmacological induced metabolic changes of adipocytes via changes in the fluorescence of the metabolic co-factors NADH and FAD. In agreement with recent publications NADH fluorescence suggests the presence of four distinct lifetimes in cell culture and tissue with two unbound and two protein bound states which show different responses to treatment with metabolic modifiers. We evaluated the effects on NADH fluorescence lifetime after systematic manipulations to change the balance between oxidative and glycolytic metabolism using five pharmacological reagents - Oligomycin, 2-DG, FCCP, Rotenone, and Glucose - which interact with different parts of the metabolic pathway. We established several ratios between the four distinct lifetimes of NADH after treatment and compared the results to oxygen consumption rate and extracellular acidification rate. We demonstrated, for the first time, a correlation between the two unbound fluorescence lifetimes components and glycolytic and oxidative metabolic activity with a significant higher sensitivity compared to the commonly used free-to-bound ratio of NADH. Analyzing all four lifetime components of NADH has the potential to become a powerful tool to evaluate metabolic activity of adipocytes with subcellular resolution.

  13. Rapid Submarine Melting Driven by Subglacial Discharge, LeConte Glacier, Alaska

    Science.gov (United States)

    Motyka, R. J.; Dryer, W. P.; Amundson, J. M.; Truffer, M.; Fahnestock, M. A.

    2013-12-01

    Submarine melting impacts the stability of tidewater glaciers worldwide, but the connections between the ocean, a warming climate, and retreat of outlet glaciers are poorly known. Clearly warm seawater plays an important role, but the tremendous heat potential resident in oceans and fjords must first be brought into contact with outlet glacier termini in order to affect them. We show here that for many glaciers, the principal process driving high rates of submarine melting is subglacial discharge of freshwater. This buoyant discharge draws in warm seawater, entraining it in a turbulent upwelling convective flow along the submarine face that melts glacier ice. To capture the effect of changing subglacial discharge on submarine melting, we conducted four days of hydrographic transects during late summer 2012 at LeConte Glacier, Alaska. A major rainstorm allowed us to directly measure the influence of large changes in subglacial discharge. We found strong submarine melt rates that increased from 9.0×1.0 to 16.8×1.3 m/d (ice face equivalent frontal ablation) as subglacial discharge increased from 130 to 440 m^3/s over a four day period. This subglacial discharge drove influx of warm seawater (thermal forcing ~ 8° C) to the terminus with fluxes increasing from 1800 to 4000 m3/s. Our ice equivalent frontal ablation rates due to submarine melting are two to three times values found for Greenland glaciers, where thermal forcing is substantially lower (~ 1 - 4 °C) and termini are wider. Together, these studies confirm the importance of submarine melting at grounded glaciers. At LeConte, the total frontal ablation rate (calving flux plus submarine melting) is ~ 3.0 x10^6 m^3/d w.e., which far surpasses surface ablation. One-half to two-thirds of the frontal ablation during September 2012 can be attributed to submarine melting. A two-layer model driven by a buoyant plume of subglacial discharge has been previously invoked to describe the proglacial fjord circulation

  14. The influence of Antarctic subglacial volcanism on the global iron cycle during the Last Glacial Maximum

    Science.gov (United States)

    Frisia, Silvia; Weyrich, Laura S.; Hellstrom, John; Borsato, Andrea; Golledge, Nicholas R.; Anesio, Alexandre M.; Bajo, Petra; Drysdale, Russell N.; Augustinus, Paul C.; Rivard, Camille; Cooper, Alan

    2017-06-01

    Marine sediment records suggest that episodes of major atmospheric CO2 drawdown during the last glacial period were linked to iron (Fe) fertilization of subantarctic surface waters. The principal source of this Fe is thought to be dust transported from southern mid-latitude deserts. However, uncertainty exists over contributions to CO2 sequestration from complementary Fe sources, such as the Antarctic ice sheet, due to the difficulty of locating and interrogating suitable archives that have the potential to preserve such information. Here we present petrographic, geochemical and microbial DNA evidence preserved in precisely dated subglacial calcites from close to the East Antarctic Ice-Sheet margin, which together suggest that volcanically-induced drainage of Fe-rich waters during the Last Glacial Maximum could have reached the Southern Ocean. Our results support a significant contribution of Antarctic volcanism to subglacial transport and delivery of nutrients with implications on ocean productivity at peak glacial conditions.

  15. Prospects of obtaining samples of bottom sediments from subglacial lake Vostok

    Directory of Open Access Journals (Sweden)

    Н. И. Васильев

    2017-04-01

    Full Text Available The paper proves the timeliness of obtaining and examining bottom sediments from subglacial Lake Vostok. Predictive geological section of Lake Vostok and information value of bottom sediments have been examined. Severe requirements towards environmental security of lake examinations and sampling of bottom sediments rule out the use of conventional drilling technologies, as they would pollute the lake with injection liquid from the borehole. In order to carry out sampling of bottom sediments from the subglacial lake, it is proposed to use a dynamically balanced tool string, which enables rotary drilling without any external support on borehole walls to transmit counter torque.     A theoretical analysis has been carried out to assess the operation of the tool string, which is a two-mass oscillatory electromechanical system of reciprocating and rotating motion (RRM with two degrees of freedom.

  16. Metabolic activation and DNA adducts of dinitropyrenes. Research report, 1 January 1984-31 December 1985

    Energy Technology Data Exchange (ETDEWEB)

    Beland, F.A.

    1986-01-01

    The study explored the sequence of reactions through which nitrated pyrenes, important mutagenic and potentially carcinogenic components of diesel exhaust, are converted metabolically within bacterial and mammalian cells into reactive forms that damage DNA. Results indicate that (1) factors in addition to nitroreduction were involved in the metabolic activation of dinitropyrene, (2) differences exist among the nitropyrene compounds tested in the mechanism of nitroreduction, (3) reduction to 1-nitrosopyrene is the limiting step in the metabolic activation of 1-nitropyrene, while subsequent esterification of the reduced intermediates is critical for the activation of the dinitropyrenes, (4) the extent of DNA binding of the different compounds was correlated with the extent of their nitroreduction, and (5) anaerobic intestinal microflora play an important role in metabolizing orally administered nitropyrenes.

  17. Physical Activity and Sedentary Time Associations with Metabolic Health Across Weight Statuses in Children and Adolescents

    DEFF Research Database (Denmark)

    Kuzik, Nicholas; Carson, Valerie; Andersen, Lars Bo

    2017-01-01

    OBJECTIVE: The aim of this study was to examine the prevalence of metabolic health across weight statuses and the associations of physical activity and sedentary time within and across metabolic health-weight status groups. METHODS: Six studies (n = 4,581) from the International Children......'s Accelerometry Database were used. Sedentary time, light physical activity, and moderate to vigorous physical activity (MVPA) were accelerometer derived. Individuals were classified with normal weight (NW), overweight, or obesity. Strict and lenient composite definitions of metabolic health were created......, as well as MU-NW, -overweight, and -obesity classifications, compared with the MH-NW group. Furthermore, more sedentary time was associated with higher odds of MU-NW classification compared with the MH-NW group. CONCLUSIONS: More MVPA was beneficial for metabolic health and weight status, whereas lower...

  18. Geomorphological evidence of channelized subglacial meltwater drainage under the Scandinavian Ice Sheet

    Science.gov (United States)

    Adamczyk, Aleksander; Wysota, Wojciech; Sobiech, Marcin; Piotrowski, Jan A.

    2016-04-01

    The impact of subglacial meltwater erosion on shaping glacial landscapes is contentious and often difficult to constrain due to the lack of unequivocal diagnostic criteria. The same holds for the role of subglacial meltwater in glacier movement processes and sediment transport and deposition. Here we present new evidence of widespread channelized erosion under the southern, soft-bedded fringe of the last Scandinavian Ice Sheet (SIS) based on high-resolution terrain analysis with LiDAR imagery. We identify several tens of sites with "glacial curvilineation" landscapes first recognized by Lesemann et al. (2010, 2014) and considered as evidence of erosion by turbulent meltwater flows at the ice/bed interface. The "glacial curvilineation" landscapes mapped here consist of sets of parallel, winding ridges typically several metres high and up to several kilometres long occupying glacial overdeepenings and tunnel valleys. The ridges are aligned approximately perpendicular to the past ice sheet margins and they are composed of various deposits often pre-dating the last ice advance. We interpret them as erosional remnants of older landscapes dissected by high-energy subglacial meltwater flows. These findings suggest that the palaeoglaciological significance of meltwater drainage under the southern portion of SIS may have been grossly underestimated. References Lesemann, J.-E., Piotrowski, J.A. and Wysota, W., 2010. „Glacial curvilineations": New glacial landforms produced by longitudinal vortices in subglacial meltwater flows. Geomorphology 120, 153-161. Lesemann, J.-E., Piotrowski, J.A. and Wysota, W., 2014. Genesis of the "glacial curvilineation" landscape by meltwater processes under the former Scandinavian Ice Sheet, Poland. Sedimentary Geology 312, 1-18.

  19. Metabolic, anabolic, and mitogenic insulin responses: A tissue-specific perspective for insulin receptor activators.

    Science.gov (United States)

    Bedinger, Daniel H; Adams, Sean H

    2015-11-05

    Insulin acts as the major regulator of the fasting-to-fed metabolic transition by altering substrate metabolism, promoting energy storage, and helping activate protein synthesis. In addition to its glucoregulatory and other metabolic properties, insulin can also act as a growth factor. The metabolic and mitogenic responses to insulin are regulated by divergent post-receptor signaling mechanisms downstream from the activated insulin receptor (IR). However, the anabolic and growth-promoting properties of insulin require tissue-specific inter-relationships between the two pathways, and the nature and scope of insulin-regulated processes vary greatly across tissues. Understanding the nuances of this interplay between metabolic and growth-regulating properties of insulin would have important implications for development of novel insulin and IR modulator therapies that stimulate insulin receptor activation in both pathway- and tissue-specific manners. This review will provide a unique perspective focusing on the roles of "metabolic" and "mitogenic" actions of insulin signaling in various tissues, and how these networks should be considered when evaluating selective pharmacologic approaches to prevent or treat metabolic disease. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Activities of key metabolic enzymes in the heater organs of scombroid fishes.

    Science.gov (United States)

    Tullis, A; Block, B A; Sidell, B D

    1991-11-01

    Maximal in vitro activities of key metabolic enzymes were measured in brain and eye heaters of five species of scombroid fishes. Istiophorid billfishes (blue marlin, striped marlin and Mediterranean spearfish), xiphiid billfishes (Pacific and Mediterranean stocks) and a scombrid fish (butterfly mackerel) were included in the analysis. Our main objectives were (1) to assess the maximum possible substrate flux in heater tissue, and (2) to determine what metabolic substrates could fuel heat production. Heater tissue of all scombroids examined showed extremely high oxidative capacity. Activities of citrate synthase, a commonly measured index of oxidative metabolism, included the highest value ever reported for vertebrate tissue. In most billfishes, citrate synthase activities were similar to or higher than those found for mammalian cardiac and avian flight muscle. Marker enzymes for aerobic carbohydrate metabolism (hexokinase) and fatty acid metabolism (carnitine palmitoyltransferase and 3-hydroxyacyl-CoA dehydrogenase) also displayed extraordinarily high activities. Activities of carnitine palmitoyltransferase measured in heater organs were among the highest reported for vertebrates. These results indicate that heat production could be fueled aerobically by either lipid or carbohydrate metabolism. Inter- and intraspecifically, heater organs of fishes from the colder Mediterranean waters had a higher aerobic capacity and, hence, a greater heat-generating potential, than fishes from the warmer waters of the Pacific. This difference may be attributed to different thermal environments or it may result from allometry, since fishes caught in the Mediterranean were considerably smaller than those caught in the Pacific.

  1. Immune challenge affects basal metabolic activity in wintering great tits.

    OpenAIRE

    Ots, I.; Kerimov, A. B.; Ivankina, E. V.; Ilyina, T. A.; Hõrak, P.

    2001-01-01

    The costs of exploiting an organism's immune function are expected to form the basis of many life-history trade-offs. However, there has been debate about whether such costs can be paid in energetic and nutritional terms. We addressed this question in a study of wintering, free-living, male great tits by injecting them with a novel, non-pathogenic antigen (sheep red blood cells) and measuring the changes in their basal metabolic rates and various condition indices subsequent to immune challen...

  2. Subglacial discharges create fluctuating foraging hotspots for sea birds in tidewater glacier bays

    Science.gov (United States)

    Urbanski, Jacek Andrzej; Stempniewicz, Lech; Węsławski, Jan Marcin; Dragańska-Deja, Katarzyna; Wochna, Agnieszka; Goc, Michał; Iliszko, Lech

    2017-01-01

    Although the processes occurring at the front of an ice face in tidewater glacier bays still await thorough investigation, their importance to the rapidly changing polar environment is spurring a considerable research effort. Glacier melting, sediment delivery and the formation of seabird foraging hotspots are governed by subglacial discharges of meltwater. We have combined the results of tracking black-legged kittiwakes Rissa tridactyla equipped with GPS loggers, analyses of satellite images and in situ measurements of water temperature, salinity and turbidity in order to examine the magnitude and variability of such hotspots in the context of glacier bay hydrology. Small though these hotspots are in size, foraging in them appears to be highly intensive. They come into existence only if the subglacial discharge reaches the surface, if the entrainment velocity at a conduit is high and if there is sufficient macroplankton in the entrainment layer. The position and type of subglacial discharges may fluctuate in time and space, thereby influencing glacier bay hydrology and the occurrence of foraging hotspots. PMID:28266602

  3. Self-affine subglacial roughness: consequences for radar scattering and basal water discrimination in northern Greenland

    Science.gov (United States)

    Jordan, Thomas M.; Cooper, Michael A.; Schroeder, Dustin M.; Williams, Christopher N.; Paden, John D.; Siegert, Martin J.; Bamber, Jonathan L.

    2017-05-01

    Subglacial roughness can be determined at a variety of length scales from radio-echo sounding (RES) data either via statistical analysis of topography or inferred from basal radar scattering. Past studies have demonstrated that subglacial terrain exhibits self-affine (power law) roughness scaling behaviour, but existing radar scattering models do not take this into account. Here, using RES data from northern Greenland, we introduce a self-affine statistical framework that enables a consistent integration of topographic-scale roughness with the electromagnetic theory of radar scattering. We demonstrate that the degree of radar scattering, quantified using the waveform abruptness (pulse peakiness), is topographically controlled by the Hurst (roughness power law) exponent. Notably, specular bed reflections are associated with a lower Hurst exponent, with diffuse scattering associated with a higher Hurst exponent. Abrupt waveforms (specular reflections) have previously been used as a RES diagnostic for basal water, and to test this assumption we compare our radar scattering map with a recent prediction for the basal thermal state. We demonstrate that the majority of thawed regions (above pressure melting point) exhibit a diffuse scattering signature, which is in contradiction to the prior approach. Self-affine statistics provide a generalised model for subglacial terrain and can improve our understanding of the relationship between basal properties and ice-sheet dynamics.

  4. Preliminary Analysis of Life within a Former Subglacial Lake Sediment in Antarctica

    Directory of Open Access Journals (Sweden)

    Gavin Burns

    2013-09-01

    Full Text Available Since the first descriptions of Antarctic subglacial lakes, there has been a growing interest and awareness of the possibility that life will exist and potentially thrive in these unique and little known environments. The unusual combination of selection pressures, and isolation from the rest of the biosphere, might have led to novel adaptations and physiology not seen before, or indeed to the potential discovery of relic populations that may have become extinct elsewhere. Here we report the first microbiological analysis of a sample taken from a former subglacial lake sediment in Antarctica (Lake Hodgson, on the Antarctic Peninsula. This is one of a number of subglacial lakes just emerging at the margins of the Antarctic ice sheet due to the renewed onset of deglaciation. Microbial diversity was divided into 23.8% Actinobacteria, 21.6% Proteobacteria, 20.2% Planctomycetes and 11.6% Chloroflexi, characteristic of a range of habitat types ( Overall, common sequences were neither distinctly polar, low temperature, freshwater nor marine. Twenty three percent of this diversity could only be identified to “unidentified bacterium”. Clearly these are diverse ecosystems with enormous potential.

  5. Subglacial discharges create fluctuating foraging hotspots for sea birds in tidewater glacier bays

    Science.gov (United States)

    Urbanski, Jacek Andrzej; Stempniewicz, Lech; Węsławski, Jan Marcin; Dragańska-Deja, Katarzyna; Wochna, Agnieszka; Goc, Michał; Iliszko, Lech

    2017-03-01

    Although the processes occurring at the front of an ice face in tidewater glacier bays still await thorough investigation, their importance to the rapidly changing polar environment is spurring a considerable research effort. Glacier melting, sediment delivery and the formation of seabird foraging hotspots are governed by subglacial discharges of meltwater. We have combined the results of tracking black-legged kittiwakes Rissa tridactyla equipped with GPS loggers, analyses of satellite images and in situ measurements of water temperature, salinity and turbidity in order to examine the magnitude and variability of such hotspots in the context of glacier bay hydrology. Small though these hotspots are in size, foraging in them appears to be highly intensive. They come into existence only if the subglacial discharge reaches the surface, if the entrainment velocity at a conduit is high and if there is sufficient macroplankton in the entrainment layer. The position and type of subglacial discharges may fluctuate in time and space, thereby influencing glacier bay hydrology and the occurrence of foraging hotspots.

  6. Comparative Analysis of the Rats' Gut Microbiota Composition in Animals with Different Ginsenosides Metabolizing Activity.

    Science.gov (United States)

    Dong, Wei-Wei; Xuan, Fang-Ling; Zhong, Fei-Liang; Jiang, Jun; Wu, Songquan; Li, Donghao; Quan, Lin-Hu

    2017-01-18

    Following oral intake of Panax ginseng, major ginsenosides are metabolized to deglycosylated ginsenosides by gut microbiota before absorption into the blood. As the composition of gut microbiota varies between individuals, metabolic activities are significantly different. We selected 6 rats with low efficiency metabolism (LEM) and 6 rats with high efficiency metabolism (HEM) from 60 rats following oral administration of Panax ginseng extract, and analyzed their gut microbiota composition using Illumina HiSeq sequencing of the 16S rRNA gene. The components of gut microbiota between the LEM and HEM groups were significantly different. Between the 2 groups, S24-7, Alcaligenaceae, and Erysipelotrichaceae occupied most OTUs of the HEM group, which was notably higher than the LEM group. Furthermore, we isolated Bifidobacterium animalis GM1 that could convert the ginsenoside Rb1 to Rd. The result implies that these specific intestinal bacteria may dominate the metabolism of Panax ginseng.

  7. Molecular evidence for an active endogenous microbiome beneath glacial ice.

    Science.gov (United States)

    Hamilton, Trinity L; Peters, John W; Skidmore, Mark L; Boyd, Eric S

    2013-07-01

    Geologic, chemical and isotopic evidence indicate that Earth has experienced numerous intervals of widespread glaciation throughout its history, with roughly 11% of present day Earth's land surface covered in ice. Despite the pervasive nature of glacial ice both today and in Earth's past and the potential contribution of these systems to global biogeochemical cycles, the composition and phylogenetic structure of an active microbial community in subglacial systems has yet to be described. Here, using RNA-based approaches, we demonstrate the presence of active and endogenous archaeal, bacterial and eukaryal assemblages in cold (0-1 °C) subglacial sediments sampled from Robertson Glacier, Alberta, Canada. Patterns in the phylogenetic structure and composition of subglacial sediment small subunit (SSU) ribosomal RNA (rRNA) assemblages indicate greater diversity and evenness than in glacial surface environments, possibly due to facilitative or competitive interactions among populations in the subglacial environment. The combination of phylogenetically more even and more diverse assemblages in the subglacial environment suggests minimal niche overlap and optimization to capture a wider spectrum of the limited nutrients and chemical energy made available from weathering of bedrock minerals. The prevalence of SSU rRNA affiliated with lithoautotrophic bacteria, autotrophic methane producing archaea and heterotrophic eukarya in the subglacial environment is consistent with this hypothesis and suggests an active contribution to the global carbon cycle. Collectively, our findings demonstrate that subglacial environments harbor endogenous active ecosystems that have the potential to impact global biogeochemical cycles over extended periods of time.

  8. Metabolic and environmental aspects of fusion reactor activation products: niobium

    Energy Technology Data Exchange (ETDEWEB)

    Easterly, C.E.; Shank, K.E.

    1977-11-01

    A summary of the metabolic and environmental aspects of niobium is presented. The toxicological symptoms from exposure to niobium are given, along with lethal concentration values for acute and chronic exposures. Existing human data are presented; animal uptake and retention data are analyzed for various routes of administration. Recommended metabolic values are also presented along with comments concerning their use and appropriateness. The natural distribution of niobium is given for freshwater, seawater, and the biosphere. Concentration factors and retention of /sup 95/Nb in the environment are discussed with reference to: plant retention via leaf absorption; plant retention via root uptake; uptake in terrestrial animals from plants; uptake in freshwater organisms; uptake in marine organisms; and movement in soil. Conclusions are drawn regarding needs for future work in these areas. This review was undertaken because niobium is expected to be a key metal in the development of commercial fusion reactors. It is recognized that niobium will likely not be used in the first generation reactors as a structural material but will appear as an alloy in such materials as superconducting wire.

  9. Polyphosphate--an ancient energy source and active metabolic regulator.

    Science.gov (United States)

    Achbergerová, Lucia; Nahálka, Jozef

    2011-08-04

    There are a several molecules on Earth that effectively store energy within their covalent bonds, and one of these energy-rich molecules is polyphosphate. In microbial cells, polyphosphate granules are synthesised for both energy and phosphate storage and are degraded to produce nucleotide triphosphate or phosphate. Energy released from these energetic carriers is used by the cell for production of all vital molecules such as amino acids, nucleobases, sugars and lipids. Polyphosphate chains directly regulate some processes in the cell and are used as phosphate donors in gene regulation. These two processes, energetic metabolism and regulation, are orchestrated by polyphosphate kinases. Polyphosphate kinases (PPKs) can currently be categorized into three groups (PPK1, PPK2 and PPK3) according their functionality; they can also be divided into three groups according their homology (EcPPK1, PaPPK2 and ScVTC). This review discusses historical information, similarities and differences, biochemical characteristics, roles in stress response regulation and possible applications in the biotechnology industry of these enzymes. At the end of the review, a hypothesis is discussed in view of synthetic biology applications that states polyphosphate and calcium-rich organelles have endosymbiotic origins from ancient protocells that metabolized polyphosphate.

  10. Polyphosphate - an ancient energy source and active metabolic regulator

    Science.gov (United States)

    2011-01-01

    There are a several molecules on Earth that effectively store energy within their covalent bonds, and one of these energy-rich molecules is polyphosphate. In microbial cells, polyphosphate granules are synthesised for both energy and phosphate storage and are degraded to produce nucleotide triphosphate or phosphate. Energy released from these energetic carriers is used by the cell for production of all vital molecules such as amino acids, nucleobases, sugars and lipids. Polyphosphate chains directly regulate some processes in the cell and are used as phosphate donors in gene regulation. These two processes, energetic metabolism and regulation, are orchestrated by polyphosphate kinases. Polyphosphate kinases (PPKs) can currently be categorized into three groups (PPK1, PPK2 and PPK3) according their functionality; they can also be divided into three groups according their homology (EcPPK1, PaPPK2 and ScVTC). This review discusses historical information, similarities and differences, biochemical characteristics, roles in stress response regulation and possible applications in the biotechnology industry of these enzymes. At the end of the review, a hypothesis is discussed in view of synthetic biology applications that states polyphosphate and calcium-rich organelles have endosymbiotic origins from ancient protocells that metabolized polyphosphate. PMID:21816086

  11. Association between physical activity and metabolic syndrome among Malay adults in a developing country, Malaysia.

    Science.gov (United States)

    Chu, Anne H Y; Moy, F M

    2014-03-01

    Metabolic syndrome is a highly prevalent health problem within the adult population in developing countries. We aimed to study the association of physical activity levels and metabolic risk factors among Malay adults in Malaysia. Cross-sectional. Body mass index, waist circumference, and systolic/diastolic blood pressure, fasting blood glucose, fasting triglyceride and high-density lipoprotein cholesterol levels were measured in 686 Malay participants (aged 35-74 years). Self-reported physical activity was obtained with the validated International Physical Activity Questionnaire (Malay version) and categorized into low, moderate or high activity levels. Individuals who were classified as overweight and obese predominated (65.6%). On the basis of the modified NCEP ATP III criteria, metabolic syndrome was diagnosed in 31.9% of all participants, of whom 46.1% were men and 53.9% were women. The prevalence of metabolic syndrome among participants with low, moderate or high activity levels was 13.3%, 11.7% and 7.0%, respectively (pmetabolic risk factors and activity categories (pmetabolic syndrome in the moderate and high activity categories were 0.42 (95% CI: 0.27-0.65) and 0.52 (95% CI: 0.35-0.76), respectively, adjusted for gender. Moderate and high activity levels were each associated with reduced odds for metabolic syndrome independent of gender. Although a slightly lower prevalence of metabolic syndrome was associated with high activity than with moderate activity, potential health benefits were observed when moderate activity was performed. Copyright © 2013 Sports Medicine Australia. All rights reserved.

  12. HIV protease inhibitors disrupt lipid metabolism by activating endoplasmic reticulum stress and inhibiting autophagy activity in adipocytes.

    Directory of Open Access Journals (Sweden)

    Beth S Zha

    Full Text Available HIV protease inhibitors (PI are core components of Highly Active Antiretroviral Therapy (HAART, the most effective treatment for HIV infection currently available. However, HIV PIs have now been linked to lipodystrophy and dyslipidemia, which are major risk factors for cardiovascular disease and metabolic syndrome. Our previous studies have shown that HIV PIs activate endoplasmic reticulum (ER stress and disrupt lipid metabolism in hepatocytes and macrophages. Yet, little is known on how HIV PIs disrupt lipid metabolism in adipocytes, a major cell type involved in the pathogenesis of metabolic syndrome.Cultured and primary mouse adipocytes and human adipocytes were used to examine the effect of frequently used HIV PIs in the clinic, lopinavir/ritonavir, on adipocyte differentiation and further identify the underlying molecular mechanism of HIV PI-induced dysregulation of lipid metabolism in adipocytes. The results indicated that lopinavir alone or in combination with ritonavir, significantly activated the ER stress response, inhibited cell differentiation, and induced cell apoptosis in adipocytes. In addition, HIV PI-induced ER stress was closely linked to inhibition of autophagy activity. We also identified through the use of primary adipocytes of CHOP(-/- mice that CHOP, the major transcriptional factor of the ER stress signaling pathway, is involved in lopinavir/ritonavir-induced inhibition of cell differentiation in adipocytes. In addition, lopinavir/ritonavir-induced ER stress appears to be associated with inhibition of autophagy activity in adipocytes.Activation of ER stress and impairment of autophagy activity are involved in HIV PI-induced dysregulation of lipid metabolism in adipocytes. The key components of ER stress and autophagy signaling pathways are potential therapeutic targets for HIV PI-induced metabolic side effects in HIV patients.

  13. Temporal repeatability of metabolic rate and the effect of organ mass and enzyme activity on metabolism in European eel (Anguilla anguilla).

    Science.gov (United States)

    Boldsen, Martin Maagaard; Norin, Tommy; Malte, Hans

    2013-05-01

    Intraspecific variation in metabolic rate of fish can be pronounced and have been linked to various fitness-related behavioural and physiological traits, but the underlying causes for this variation have received far less attention than the consequences of it. In the present study we investigated whether European eels (Anguilla anguilla) displayed temporal repeatability of body-mass-corrected (residual) metabolic rate over a two-month period and if variations in organ mass and enzyme activity between individual fish could be the cause for the observed variation in metabolic rate. Both standard metabolic rate (SMR; Pearson's r=0.743) and routine metabolic rate (RMR; r=0.496) were repeatable over the two-month period. Repeatability of RMR is an interesting finding as it indicates that the level of spontaneous activity in respirometer-confined fish is not random. Cumulative organ mass (liver, heart, spleen and intestine; mean 1.6% total body mass) was found to explain 38% of the variation in SMR (r=0.613) with the liver (one of the metabolically most active organs) being the driver for the correlation between organ mass and metabolic rate. No relationships were found for either liver citrate synthase or cytochrome oxidase activity and metabolic rate in the European eels. Reasons for, and contributions to, the observed variation in metabolic rate are discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Nonlinear Dielectric Spectroscopy as an Indirect Probe of Metabolic Activity in Thylakoid Membrane

    Directory of Open Access Journals (Sweden)

    John H. Miller

    2011-01-01

    Full Text Available Nonlinear dielectric spectroscopy (NDS is a non-invasive probe of cellular metabolic activity with potential application in the development of whole-cell biosensors. However, the mechanism of NDS interaction with metabolic membrane proteins is poorly understood, partly due to the inherent complexity of single cell organisms. Here we use the light-activated electron transport chain of spinach thylakoid membrane as a model system to study how NDS interacts with metabolic activity. We find protein modification, as opposed to membrane pump activity, to be the dominant source of NDS signal change in this system. Potential mechanisms for such protein modifications include reactive oxygen species generation and light-activated phosphorylation.

  15. Imaging of Cellular Oxidoreductase Activity Suggests Mixotrophic Metabolisms in Thiomargarita spp.

    Science.gov (United States)

    Bailey, Jake V; Flood, Beverly E; Ricci, Elizabeth; Delherbe, Nathalie

    2017-11-07

    The largest known bacteria, Thiomargarita spp., have yet to be isolated in pure culture, but their large size allows for individual cells to be monitored in time course experiments or to be individually sorted for omics-based investigations. Here we investigated the metabolism of individual cells of Thiomargarita spp. by using a novel application of a tetrazolium-based dye that measures oxidoreductase activity. When coupled with microscopy, staining of the cells with a tetrazolium-formazan dye allows metabolic responses in Thiomargarita spp. to be to be tracked in the absence of observable cell division. Additionally, the metabolic activity of Thiomargarita sp. cells can be differentiated from the metabolism of other microbes in specimens that contain adherent bacteria. The results of our redox dye-based assay suggest that Thiomargarita is the most metabolically versatile under anoxic conditions, where it appears to express cellular oxidoreductase activity in response to the electron donors succinate, acetate, citrate, formate, thiosulfate, H2, and H2S. Under hypoxic conditions, formazan staining results suggest the metabolism of succinate and likely acetate, citrate, and H2S. Cells incubated under oxic conditions showed the weakest formazan staining response, and then only to H2S, citrate, and perhaps succinate. These results provide experimental validation of recent genomic studies of Candidatus Thiomargarita nelsonii that suggest metabolic plasticity and mixotrophic metabolism. The cellular oxidoreductase response of bacteria attached to the exterior of Thiomargarita also supports the possibility of trophic interactions between these largest of known bacteria and attached epibionts.IMPORTANCE The metabolic potential of many microorganisms that cannot be grown in the laboratory is known only from genomic data. Genomes of Thiomargarita spp. suggest that these largest of known bacteria are mixotrophs, combining lithotrophic metabolism with organic carbon

  16. Total physical activity volume, physical activity intensity, and metabolic syndrome: 1999-2004 National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Churilla, James R; Fitzhugh, Eugene C

    2012-02-01

    This study examined the association of total physical activity volume (TPAV) and physical activity (PA) from three domains [leisure-time physical activity (LTPA), domestic, transportation] with metabolic syndrome. We also investigated the relationship between LTPA intensity and metabolic syndrome risk. Sample included adults who participated in the 1999-2004 National Health and Nutrition Examination Survey. Physical activity measures were created for TPAV, LTPA, domestic PA, and transportational PA. For each, a six-level measure based upon no PA (level 1) and quintiles (levels 2-6) of metabolic equivalents (MET)·min·wk(-1) was created. A three-level variable associated with the current Department of Health and Human Services (DHHS) PA recommendation was also created. SAS and SUDAAN were used for the statistical analysis. Adults reporting the greatest volume of TPAV and LTPA were found to be 36% [odds ratio (OR) 0.64; 95% confidence interval (CI) 0.49-0.83] and 42% (OR 0.58; 95% CI 0.43-0.77), respectively, less likely to have metabolic syndrome. Domestic and transportational PA provided no specific level of protection from metabolic syndrome. Those reporting a TPAV that met the DHHS PA recommendation were found to be 33% (OR 0.67; 95%; CI 0.55-0.83) less likely to have metabolic syndrome compared to their sedentary counterparts. Adults reporting engaging in only vigorous-intensity LTPA were found to be 37% (OR 0.63; 95 CI 0.42-0.96) to 56% (OR 0.44; 95% CI 0.29-0.67) less likely to have metabolic syndrome. Volume, intensity, and domain of PA may all play important roles in reducing the prevalence and risk of metabolic syndrome.

  17. A Metabolic Biofuel Cell: Conversion of Human Leukocyte Metabolic Activity to Electrical Currents

    Directory of Open Access Journals (Sweden)

    Cui X Tracy

    2011-05-01

    Full Text Available Abstract An investigation of the electrochemical activity of human white blood cells (WBC for biofuel cell (BFC applications is described. WBCs isolated from whole human blood were suspended in PBS and introduced into the anode compartment of a proton exchange membrane (PEM fuel cell. The cathode compartment contained a 50 mM potassium ferricyanide solution. Average current densities between 0.9 and 1.6 μA cm-2 and open circuit potentials (Voc between 83 and 102 mV were obtained, which were both higher than control values. Cyclic voltammetry was used to investigate the electrochemical activity of the activated WBCs in an attempt to elucidate the mechanism of electron transfer between the cells and electrode. Voltammograms were obtained for the WBCs, including peripheral blood mononuclear cells (PBMCs - a lymphocyte-monocyte mixture isolated on a Ficoll gradient, a B lymphoblastoid cell line (BLCL, and two leukemia cell lines, namely K562 and Jurkat. An oxidation peak at about 363 mV vs. SCE for the PMA (phorbol ester activated primary cells, with a notable absence of a reduction peak was observed. Oxidation peaks were not observed for the BLCL, K562 or Jurkat cell lines. HPLC confirmed the release of serotonin (5-HT from the PMA activated primary cells. It is believed that serotonin, among other biochemical species released by the activated cells, contributes to the observed BFC currents.

  18. A metabolic biofuel cell: conversion of human leukocyte metabolic activity to electrical currents.

    Science.gov (United States)

    Justin, Gusphyl A; Zhang, Yingze; Cui, X Tracy; Bradberry, Charles W; Sun, Mingui; Sclabassi, Robert J

    2011-05-10

    An investigation of the electrochemical activity of human white blood cells (WBC) for biofuel cell (BFC) applications is described. WBCs isolated from whole human blood were suspended in PBS and introduced into the anode compartment of a proton exchange membrane (PEM) fuel cell. The cathode compartment contained a 50 mM potassium ferricyanide solution. Average current densities between 0.9 and 1.6 μA cm-2 and open circuit potentials (Voc) between 83 and 102 mV were obtained, which were both higher than control values. Cyclic voltammetry was used to investigate the electrochemical activity of the activated WBCs in an attempt to elucidate the mechanism of electron transfer between the cells and electrode. Voltammograms were obtained for the WBCs, including peripheral blood mononuclear cells (PBMCs - a lymphocyte-monocyte mixture isolated on a Ficoll gradient), a B lymphoblastoid cell line (BLCL), and two leukemia cell lines, namely K562 and Jurkat. An oxidation peak at about 363 mV vs. SCE for the PMA (phorbol ester) activated primary cells, with a notable absence of a reduction peak was observed. Oxidation peaks were not observed for the BLCL, K562 or Jurkat cell lines. HPLC confirmed the release of serotonin (5-HT) from the PMA activated primary cells. It is believed that serotonin, among other biochemical species released by the activated cells, contributes to the observed BFC currents.

  19. Breast Cancer Metabolism and Mitochondrial Activity: The Possibility of Chemoprevention with Metformin

    Directory of Open Access Journals (Sweden)

    Massimiliano Cazzaniga

    2015-01-01

    Full Text Available Metabolic reprogramming refers to the ability of cancer cells to alter their metabolism in order to support the increased energy request due to continuous growth, rapid proliferation, and other characteristics typical of neoplastic cells. It has long been believed that the increase of metabolic request was independent of the mitochondrial action but recently we know that mitochondrial activity together with metabolism plays a pivotal role in the regulation of the energy needed for tumor cell growth and proliferation. For these reasons the mitochondria pathways could be a new target for therapeutic and chemopreventive intervention. Metformin in particular is actually considered a promising agent against mitochondrial activity thanks to its ability to inhibit the mitochondrial complex I.

  20. Metaproteomics: extracting and mining proteome information to characterize metabolic activities in microbial communities

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Paul E [ORNL; Giannone, Richard J [ORNL; Xiong, Weili [ORNL; Hettich, Robert {Bob} L [ORNL

    2014-01-01

    Contemporary microbial ecology studies usually employ one or more omics approaches to investigate the structure and function of microbial communities. Among these, metaproteomics aims to characterize the metabolic activities of the microbial membership, providing a direct link between the genetic potential and functional metabolism. The successful deployment of metaproteomics research depends on the integration of high-quality experimental and bioinformatic techniques for uncovering the metabolic activities of a microbial community in a way that is complementary to other meta-omic approaches. The essential, quality-defining informatics steps in metaproteomics investigations are: (1) construction of the metagenome, (2) functional annotation of predicted protein-coding genes, (3) protein database searching, (4) protein inference, and (5) extraction of metabolic information. In this article, we provide an overview of current bioinformatic approaches and software implementations in metaproteome studies in order to highlight the key considerations needed for successful implementation of this powerful community-biology tool.

  1. Numerical modelling of esker formation in semi-circular subglacial channels

    Science.gov (United States)

    Beaud, Flavien; Flowers, Gwenn E.; Venditti, Jeremy G.

    2017-04-01

    Eskers hold valuable information about past subglacial hydraulic conditions in their spatial organization, geometry, and sedimentary structures. The relations between hydraulic conditions and esker properties are nevertheless intricate as the formation of eskers has been mainly inferred from descriptive theories, about which a consensus has yet to be reached. Eskers are prevalent in areas of rigid bed and thin till cover and their formation is thought to be predominantly controlled by either water or sediment availability. In this study, we develop a 1-D numerical model of sediment transport in semi-circular bedrock-floored channels to explore the physical processes leading to esker formation. The model encompasses channel evolution by melt-opening created by the viscous heat dissipated as water flows, the creep closure of the ice walls, and changes in cross-sectional area due to sediment accumulation and removal. We find that a bottleneck in sediment transport close to the terminus is an inherent characteristic of subglacial channels. Creep closure is reduced as the ice thins towards the terminus and hydraulic potential gradients decline, thus reducing shear stresses. This bottleneck is accentuated when water discharge drops in a well established channel. We find the conditions most conducive to sediment deposition are low ice-surface slopes within several kilometres of the terminus and water discharge fluctuations over a few to several weeks. The model also produces shear stresses large enough to transport boulders under typical melt-season conditions. Our results thus suggest that incipient eskers form toward the end of the melt season, provided water input and sediment supply are sufficient. Overall these findings corroborate the theory that eskers are formed progressively during the waning stage of an ice sheet, although we suggest that eskers are a natural manifestation of the subglacial hydraulic system in the presence of an adequate trade-off between

  2. Implications of sediment transport by subglacial water flow for interpreting contemporary glacial erosion rates

    Science.gov (United States)

    Beaud, Flavien; Flowers, Gwenn E.; Venditti, Jeremy G.

    2017-04-01

    The role of glaciers in landscape evolution is central to the interactions between climate and tectonic forces at high latitudes and in mountainous regions. Sediment yields from glacierized basins are used to quantify contemporary erosion rates on seasonal to decadal timescales, often under the assumption that subglacial water flow is the main contributor to these yields. Two recent studies have furthermore used such sediment fluxes to calibrate a glacial erosion rule, where erosion rate scales with ice sliding speed raised to a power greater than one. Subglacial sediment transport by water flow has however seldom been studied, thus the controls on sediment yield from glacierized basins remain enigmatic. To bridge this gap, we develop a 1-D model of morphodynamics in semi-circular bedrock-floored subglacial channels. We adapt a sediment conservation law from the fluvial literature, developed for both mixed bedrock / alluvial and alluvial conditions, to subglacial channels. Channel evolution is a function of the traditional melt-opening due to viscous heat dissipation from the water flow, and creep closure of the overlying ice, to which we add the closure or enlargement due to sediment deposition or removal, respectively. Using a simple ice geometry representing a land-terminating glacier, we find that the shear stresses produced by the water flow on the bed decrease significantly near the terminus. As the ice thins, creep closure decreases and large hydraulic potential gradients cannot be sustained. The resulting gradients in sediment transport lead to a bottleneck, and sediment accumulates if the sediment supply is adequate. A similar bottleneck occurs if a channel is well established and water discharge drops. Whether such constriction happens in space of time, in the presence of a sufficiently large sediment supply sediment accumulates temporarily near the terminus, followed shortly thereafter by enhanced sediment transport. Reduction in the cross-sectional area

  3. Physical activity, heart rate, metabolic profile, and estradiol in premenopausal women

    DEFF Research Database (Denmark)

    Emaus, Aina; Veierød, Marit B; Furberg, Anne-Sofie

    2008-01-01

    PURPOSE: To study whether physical inactive women with a tendency to develop metabolic syndrome have high levels of 17beta-estradiol (E2) of importance for breast cancer risk. METHODS: Two hundred and four healthy women of reproductive age were assessed for self-reported leisure-time physical...... activity (LPA), resting heart rate (HR), blood pressure (BP), anthropometry, and serum glucose, lipids, and insulin [Norwegian Energy Balance and Breast Cancer Aspect (EBBA) study]. E2 was measured in daily saliva samples throughout an entire menstrual cycle. A clustered metabolic risk score [z metabolic...

  4. Low levels of physical activity and metabolic syndrome: cross-sectional study in the Brazilian public health system

    OpenAIRE

    Turi, Bruna Camilo; Codogno, Jamile Sanches; Fernandes, Rômulo Araújo; Monteiro, Henrique Luiz

    2016-01-01

    Abstract This study investigated whether low levels of physical activity in different domains is associated with risk factors for the occurrence of metabolic syndrome or metabolic syndrome itself. Habitual physical activity level was assessed among 963 participants, aged 50 years old or more, using Baecke’s questionnaire. Risk factors for metabolic syndrome followed the recommendations of “The IDF Consensus Worldwide Definition of the Metabolic Syndrome”. All the participants were users of th...

  5. Low levels of physical activity and metabolic syndrome: cross-sectional study in the Brazilian public health system

    OpenAIRE

    Bruna Camilo Turi; Jamile Sanches Codogno; Rômulo Araújo Fernandes; Henrique Luiz Monteiro

    2016-01-01

    Abstract This study investigated whether low levels of physical activity in different domains is associated with risk factors for the occurrence of metabolic syndrome or metabolic syndrome itself. Habitual physical activity level was assessed among 963 participants, aged 50 years old or more, using Baecke’s questionnaire. Risk factors for metabolic syndrome followed the recommendations of “The IDF Consensus Worldwide Definition of the Metabolic Syndrome”. All the participant...

  6. Cardiovascular fitness, activity, and metabolic syndrome among college men and women.

    Science.gov (United States)

    Morrell, Jesse Stabile; Cook, Summer B; Carey, Gale B

    2013-10-01

    The purpose of this cross-sectional study was to examine the impact of below-average cardiovascular fitness and inactivity on the metabolic syndrome among an understudied population-undergraduate men and women, ages 18-24 years. Between January, 2010, and May, 2012, we assessed anthropometric, biochemical, and clinical measures in a convenience sample of students (n=1610) enrolled in an introductory nutrition course at a public university. We quantified the prevalence of metabolic syndrome criteria, estimated cardiovascular fitness via a 1-mile Rockport Walk Test, and evaluated daily activity via pedometer. Subjects were classified as below-average, average, and above-average fitness based upon the Rockport Walk Test; activity levels were classified as low active, somewhat active, active, or highly active according to average steps per day. Those with below-average fitness (10%) were at increased risk for being overfat, having abdominal obesity, and having the metabolic syndrome as compared to those with average or above-average fitness (odds ratio: 12.4, 10.0, and 4.7, respectively; all Pactive (metabolic syndrome criteria as compared to very active subjects (>12,500 steps/day) (0.94±0.05 vs. 0.73±0.05, P=0.01). Young, college-age adults with below-average cardiovascular fitness and/or low activity levels are at increased risk for obesity and the metabolic syndrome. Future studies should examine how promoting lifestyle habits that increase physical activity and reduce sedentary behaviors during the young adult years can improve metabolic health.

  7. Vigorous intensity physical activity is related to the metabolic syndrome independent of the physical activity dose.

    Science.gov (United States)

    Janssen, Ian; Ross, Robert

    2012-08-01

    Current physical activity guidelines imply that, by comparison with moderate physical activity (MPA), the benefits of engaging in vigorous physical activity (VPA) are attributed to the greater energy expenditure dose per unit of time and do not relate to intensity per se. The purpose of this study was to determine whether VPA influences the metabolic syndrome (MetS) independent of its influence on the energy expenditure dose of moderate-to-vigorous physical activity (MVPA). Participants consisted of 1841 adults from the 2003-06 National Health and Nutrition Examination Survey, a representative cross-sectional study. MPA and VPA were measured objectively over 7 days using Actigraph accelerometers. MetS was determined using an established clinical definition. Associations between physical activity and the MetS were determined using logistic regression and controlled for relevant covariates. Analyses revealed that VPA remained a meaningful predictor of the MetS after controlling for the total energy expenditure dose of MVPA such that the relative odds of the MetS was 0.28 (95% confidence interval 0.17-0.46) in the group with the highest VPA compared with the group with no VPA. VPA had a greater influence on the MetS than an equivalent energy expenditure dose of MPA. For instance, between 0 and 500 MET min/week of MPA the adjusted prevalence of the MetS decreased by 15.5%, whereas between 0 and 500 MET min/week of VPA the prevalence decreased by 37.1%. These cross-sectional findings suggest that VPA per se has an important role in cardiometabolic disease prevention.

  8. Physical activity, cardiorespiratory fitness, and metabolic syndrome in adolescents: a cross-sectional study.

    Science.gov (United States)

    Stabelini Neto, Antonio; Sasaki, Jeffer E; Mascarenhas, Luis P G; Boguszewski, Margaret C S; Bozza, Rodrigo; Ulbrich, Anderson Z; da Silva, Sergio G; de Campos, Wagner

    2011-08-30

    In adults, there is a substantial body of evidence that physical inactivity or low cardiorespiratory fitness levels are strongly associated with the development of metabolic syndrome. Although this association has been studied extensively in adults, little is known regarding this association in adolescents. The aim of this study was to analyze the association between physical activity and cardiorespiratory fitness levels with metabolic syndrome in Brazilian adolescents. A random sample of 223 girls (mean age, 14.4 ± 1.6 years) and 233 boys (mean age, 14.6 ± 1.6 years) was selected for the study. The level of physical activity was determined by the Bouchard three-day physical activity record. Cardiorespiratory fitness was estimated by the Leger 20-meter shuttle run test. The metabolic syndrome components assessed included waist circumference, blood pressure, HDL-cholesterol, triglycerides, and fasting plasma glucose levels. Independent Student t-tests were used to assess gender differences. The associations between physical activity and cardiorespiratory fitness with the presence of metabolic syndrome were calculated using logistic regression models adjusted for age and gender. A high prevalence of metabolic syndrome was observed in inactive adolescents (males, 11.4%; females, 7.2%) and adolescents with low cardiorespiratory fitness levels (males, 13.9%; females, 8.6%). A significant relationship existed between metabolic syndrome and low cardiorespiratory fitness (OR, 3.0 [1.13-7.94]). The prevalence of metabolic syndrome is high among adolescents who are inactive and those with low cardiorespiratory fitness. Prevention strategies for metabolic syndrome should concentrate on enhancing fitness levels early in life.

  9. Cardiac Autonomic Nervous System Activation and Metabolic Profile in Young Children: The ABCD Study.

    Science.gov (United States)

    Vrijkotte, Tanja G M; van den Born, Bert-Jan H; Hoekstra, Christine M C A; Gademan, Maaike G J; van Eijsden, Manon; de Rooij, Susanne R; Twickler, Marcel T B

    2015-01-01

    In adults, increased sympathetic and decreased parasympathetic nervous system activity are associated with a less favorable metabolic profile. Whether this is already determined at early age is unknown. Therefore, we aimed to assess the association between autonomic nervous system activation and metabolic profile and its components in children at age of 5-6 years. Cross-sectional data from an apparently healthy population (within the ABCD study) were collected at age 5-6 years in 1540 children. Heart rate (HR), respiratory sinus arrhythmia (RSA; parasympathetic activity) and pre-ejection period (PEP; sympathetic activity) were assessed during rest. Metabolic components were waist-height ratio (WHtR), systolic blood pressure (SBP), fasting triglycerides, glucose and HDL-cholesterol. Individual components, as well as a cumulative metabolic score, were analyzed. In analysis adjusted for child's physical activity, sleep, anxiety score and other potential confounders, increased HR and decreased RSA were associated with higher WHtR (P< 0.01), higher SBP (p<0.001) and a higher cumulative metabolic score (HR: p < 0.001; RSA: p < 0.01). Lower PEP was only associated with higher SBP (p <0.05). Of all children, 5.6% had 3 or more (out of 5) adverse metabolic components; only higher HR was associated with this risk (per 10 bpm increase: OR = 1.56; p < 0.001). This study shows that decreased parasympathetic activity is associated with central adiposity and higher SBP, indicative of increased metabolic risk, already at age 5-6 years.

  10. the prevalence of metabolic syndrome among active sportsmen

    African Journals Online (AJOL)

    User

    1Department of Molecular Medicine, School of Medical Sciences, College of Health Sciences,. Kwame Nkrumah University of ... volved with eighty five (85) being active sportsmen/sportswomen as study control and one hun- dred and one (101) sedentary ..... of onset of MetS among active sports men. Owiredu et al. 30 ...

  11. Physical activity in patients with metabolic syndrome: at screening and three years thereafter.

    Science.gov (United States)

    Jansen, Hanneke; den Engelsen, Corine; Rutten, Guy E H M

    2013-06-01

    Metabolic syndrome is a cluster of risk factors for cardiovascular disease and type 2 diabetes. Physical activity can decrease these risks. Many randomized clinical trials to increase physical activity have demonstrated disappointing results, and implementation in daily practice appeared to be difficult. The aim of this study was to investigate whether 3 years of usual care with available guidelines in a primary care setting result in change in physical activity in patients with screen-detected metabolic syndrome. After a population-based screening, 473 patients were diagnosed with metabolic syndrome and received advice to increase physical activity. Three years later, they were invited for follow-up. Physical activity was measured by means of the validated SQUASH questionnaire. The primary outcome measure was: % of metabolic syndrome patients that fulfill the Dutch Physical Activity Guideline (DPAG) criterion (30 min of moderately intensive physical activity at least 5 days per week) at screening and follow-up. In the final study population (n=168), the proportion of patients fulfilling the DPAG criterion did not significantly increase between screening (56.0%) and follow-up (60.7%) (P=0.29). Female gender [odds ratio (OR)=3.59; 95% confidence interval (CI) 1.24-10.39] and body mass index (BMI) at baseline (OR=0.82; 95% CI 0.69-0.97) appeared to be independent predictors of increase in physical activity. In this real-world setting, despite the advice to increase physical activity, the number of metabolic syndrome patients with sufficient physical activity did not significantly increase after 3 years. This finding confirms the need for an intensified approach to achieve an increase in physical activity in this group, with special attention to men and patients with higher BMI values.

  12. Present development concerning antimalarial activity of phospholipid metabolism inhibitors with special reference to in vivo activity

    Directory of Open Access Journals (Sweden)

    Marie L. Ancelin

    1994-01-01

    Full Text Available The systematic screening of more than 250 molecules against Plasmodium falciparum in vitro has previously shown that interfering with phospholipid metabolism is lethal to the malaria parasite. These compounds act by impairing choline transport in infected erythrocytes, resulting in phosphatidylcholine de novo biosynthesis inhibition. A thorough study was carried out with the leader compound G25, whose in vitro IC50 is 0.6 nM. It was very specific to mature parasites (trophozoïtes as determined in vitro with P. falciparum and in vivo with P. chabaudi -infected mice. This specificity corresponds to the most intense phase of phospholipid biosynthesis activity during the parasite cycle, thus corroborating the mechanism of action. The in vivo antimalarial activity (ED50 against P. chabaudi was 0.03 mg/kg, and a similar sensitivity was obtained with P. vinckei petteri, when the drug was intraperitoneally administered in a 4 day suppressive test. In contrast, P. berghei was revealed as less sensitive (3- to 20-fold, depending on the P. berghei-strain. This difference in activity could result either from the degree of synchronism of every strain, their invasion preference for mature or immature red blood cells or from an intrinsically lower sensitivity of the P. berghei strain to G25. Irrespective of the mode of administration, G25 had the same therapeutic index (lethal dose 50 (LD50/ED50 but the dose to obtain antimalarial activity after oral treatment was 100-fold higher than after intraperitoneal (or subcutaneous administration. This must be related to the low intestinal absorption of these kind of compounds. G25 succeeded to completely inhibiting parasitemia as high as 11.2% without any decrease in its therapeutic index when administered subcutaneously twice a day for at least 8 consecutive days to P. chabaudi -infected-rodent model. Transition to human preclinical investigations now requires a synthesis of molecules which would permit oral

  13. Intermittent fasting promotes adipose thermogenesis and metabolic homeostasis via VEGF-mediated alternative activation of macrophage.

    Science.gov (United States)

    Kim, Kyoung-Han; Kim, Yun Hye; Son, Joe Eun; Lee, Ju Hee; Kim, Sarah; Choe, Min Seon; Moon, Joon Ho; Zhong, Jian; Fu, Kiya; Lenglin, Florine; Yoo, Jeong-Ah; Bilan, Philip J; Klip, Amira; Nagy, Andras; Kim, Jae-Ryong; Park, Jin Gyoon; Hussein, Samer Mi; Doh, Kyung-Oh; Hui, Chi-Chung; Sung, Hoon-Ki

    2017-11-01

    Intermittent fasting (IF), a periodic energy restriction, has been shown to provide health benefits equivalent to prolonged fasting or caloric restriction. However, our understanding of the underlying mechanisms of IF-mediated metabolic benefits is limited. Here we show that isocaloric IF improves metabolic homeostasis against diet-induced obesity and metabolic dysfunction primarily through adipose thermogenesis in mice. IF-induced metabolic benefits require fasting-mediated increases of vascular endothelial growth factor (VEGF) expression in white adipose tissue (WAT). Furthermore, periodic adipose-VEGF overexpression could recapitulate the metabolic improvement of IF in non-fasted animals. Importantly, fasting and adipose-VEGF induce alternative activation of adipose macrophage, which is critical for thermogenesis. Human adipose gene analysis further revealed a positive correlation of adipose VEGF-M2 macrophage-WAT browning axis. The present study uncovers the molecular mechanism of IF-mediated metabolic benefit and suggests that isocaloric IF can be a preventive and therapeutic approach against obesity and metabolic disorders.

  14. Vitamin D3 Induces Tolerance in Human Dendritic Cells by Activation of Intracellular Metabolic Pathways.

    Science.gov (United States)

    Ferreira, Gabriela Bomfim; Vanherwegen, An-Sofie; Eelen, Guy; Gutiérrez, Ana Carolina Fierro; Van Lommel, Leentje; Marchal, Kathleen; Verlinden, Lieve; Verstuyf, Annemieke; Nogueira, Tatiane; Georgiadou, Maria; Schuit, Frans; Eizirik, Décio L; Gysemans, Conny; Carmeliet, Peter; Overbergh, Lut; Mathieu, Chantal

    2015-02-04

    Metabolic switches in various immune cell subsets enforce phenotype and function. In the present study, we demonstrate that the active form of vitamin D, 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ), induces human monocyte-derived tolerogenic dendritic cells (DC) by metabolic reprogramming. Microarray analysis demonstrated that 1,25(OH) 2 D 3 upregulated several genes directly related to glucose metabolism, tricarboxylic acid cycle (TCA), and oxidative phosphorylation (OXPHOS). Although OXPHOS was promoted by 1,25(OH) 2 D 3 , hypoxia did not change the tolerogenic function of 1,25(OH) 2 D 3 -treated DCs. Instead, glucose availability and glycolysis, controlled by the PI3K/Akt/mTOR pathway, dictate the induction and maintenance of the 1,25(OH) 2 D 3 -conditioned tolerogenic DC phenotype and function. This metabolic reprogramming is unique for 1,25(OH) 2 D 3 , because the tolerogenic DC phenotype induced by other immune modulators did not depend on similar metabolic changes. We put forward that these metabolic insights in tolerogenic DC biology can be used to advance DC-based immunotherapies, influencing DC longevity and their resistance to environmental metabolic stress. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Vitamin D3 Induces Tolerance in Human Dendritic Cells by Activation of Intracellular Metabolic Pathways

    Directory of Open Access Journals (Sweden)

    Gabriela Bomfim Ferreira

    2015-02-01

    Full Text Available Metabolic switches in various immune cell subsets enforce phenotype and function. In the present study, we demonstrate that the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH2D3, induces human monocyte-derived tolerogenic dendritic cells (DC by metabolic reprogramming. Microarray analysis demonstrated that 1,25(OH2D3 upregulated several genes directly related to glucose metabolism, tricarboxylic acid cycle (TCA, and oxidative phosphorylation (OXPHOS. Although OXPHOS was promoted by 1,25(OH2D3, hypoxia did not change the tolerogenic function of 1,25(OH2D3-treated DCs. Instead, glucose availability and glycolysis, controlled by the PI3K/Akt/mTOR pathway, dictate the induction and maintenance of the 1,25(OH2D3-conditioned tolerogenic DC phenotype and function. This metabolic reprogramming is unique for 1,25(OH2D3, because the tolerogenic DC phenotype induced by other immune modulators did not depend on similar metabolic changes. We put forward that these metabolic insights in tolerogenic DC biology can be used to advance DC-based immunotherapies, influencing DC longevity and their resistance to environmental metabolic stress.

  16. Geochemical processes leading to the precipitation of subglacial carbonate crusts at Bossons glacier, Mont Blanc Massif (French Alps)

    Science.gov (United States)

    Thomazo, Christophe; Buoncristiani, Jean-Francois; Vennin, Emmanuelle; Pellenard, Pierre; Cocquerez, Theophile; Mugnier, Jean L.; Gérard, Emmanuelle

    2017-09-01

    Cold climate carbonates can be used as paleoclimatic proxies. The mineralogy and isotopic composition of subglacially precipitated carbonate crusts provide insights into the subglacial conditions and processes occurring at the meltwater-basement rock interface of glaciers. This study documents such crusts discovered on the lee side of a gneissic roche moutonnée at the terminus of the Bossons glacier in the Mont Blanc Massif area (France). The geological context and mineralogical investigations suggest that the Ca used for the precipitation of large crystals of radial fibrous sparite observed in these crusts originated from subglacial chemical weathering of Ca-bearing minerals of the local bedrock (plagioclase and amphibole). Measurements of the carbon and oxygen isotope compositions in the crusts indicate precipitation at, or near to, equilibrium with the basal meltwater under open system conditions during refreezing processes. The homogeneous and low carbonate δ13C values (ca. -11.3‰) imply a large contribution of soil organic carbon to the Bossons subglacial meltwater carbon reservoir at the time of deposition. In addition, organic remains trapped within the subglacially precipitated carbonate crusts give an age of deposition around 6500 years cal BP suggesting that the Mid-Holocene climatic and pedological optima are archived in the Bossons glacier carbonate crusts.

  17. Disturbances to neurotransmitter levels and their metabolic enzyme activity in a freshwater planarian exposed to cadmium.

    Science.gov (United States)

    Wu, Jui-Pin; Li, Mei-Hui; Chen, Jhih-Sheng; Chung, Szu-Yao; Lee, Hui-Ling

    2015-03-01

    Using specific neurobehaviors as endpoints, previous studies suggested that planarian neurotransmission systems could be targets of Cd neurotoxicity. However, direct evidence for disturbed neurotransmission systems by Cd in treated planarians is still lacking. In planarians, dopamine (DA) and serotonin (5-HT) play critical roles in neuromuscular function, but little is known about their metabolic degradation. Therefore, in this study, we attempted to determine the appearances of DA, 5-HT, and their metabolic products in the freshwater planarian Dugesia japonica, characterize the activity of enzymes involved in their metabolism, and investigate the effects of Cd on planarian 5-HTergic and DAergic neurotransmission systems. Only DA, 5-HT, and 5-hydroxyindole-3-acetic acid (5-HIAA) were found in planarian tissues. Further enzymatic study revealed the activity of planarian monoamine oxidase (MAO) but not catechol-O-methyl transferase (COMT). These findings suggest that planarian MAO catalyzes the metabolism of 5-HT into 5-HIAA. However, DA metabolites from the MAO-involved metabolic pathway were not found, which might be due to a lack of COMT activity. Finally, in Cd-treated planarians, tissue levels of 5-HT and DA were decreased and MAO activity altered, suggesting that planarian neurotransmission systems are disturbed following Cd treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Healthier dietary pattern and lower risk of metabolic syndrome in physically active postmenopausal women.

    Science.gov (United States)

    Silva, Thaís R; Alves, Bruna Cherubini; Maturana, Maria A; Spritzer, Poli M

    2013-01-01

    To investigate the relationship between habitual physical activity and dietary intake, body composition, metabolic and hormonal variables, and cardiovascular risk factors in postmenopausal women with no evidence of cardiovascular disease. In this cross-sectional study, 105 women (mean age: 55.2 ± 4.9 years) consulting for climacteric symptoms underwent anthropometric and hormonal assessment. Usual dietary intake was assessed with a food frequency questionnaire and habitual physical activity was assessed with a digital pedometer. Participants were classified as physically inactive (metabolic syndrome increased with physical inactivity (odds ratio [OR] = 3.55, 95% confidence interval [CI], 1.08-11.66), us-CRP (OR = 6.57, 95% CI, 2.20-19.56), and percentage body fat (OR = 5.65, 95% CI, 1.19-28.89). Both physical activity and dietary choices may have contributed toward a more favorable cardiovascular profile and lower risk of metabolic syndrome in postmenopausal women.

  19. Hot Air Treatment Induces Disease Resistance through Activating the Phenylpropanoid Metabolism in Cherry Tomato Fruit.

    Science.gov (United States)

    Wei, Yingying; Zhou, Dandan; Peng, Jing; Pan, Leiqing; Tu, Kang

    2017-09-13

    To explore the effects of hot air (HA, 38 °C for 12 h) treatment on the phenylpropanoid metabolism in cherry tomatoes, phenylpropanoid metabolite levels and the activities and expression of key enzymes were analyzed in HA-treated fruit. HA treatment enhanced phenylpropanoid metabolism, as evidenced by elevated levels of phenolics and flavonoids, higher activities of phenylalanine ammonia-lyase and cinnamate-4-hydroxylase, and upregulated expression of LeCHS, LeCHI, LeF3H, and LeFLS. Levels of several phenylpropanoid metabolites were higher after HA treatment, including p-coumaric acid, caffeic acid, chlorogenic acid, isoquercitrin, quercetin, and rutin. These metabolic changes may be related to the reduced disease incidence and smaller lesion diameters observed in HA-treated fruit inoculated with Alternaria alternata (black mold) or Botrytis cinerea (gray mold). The results suggest that HA treatment induces disease resistance by activating the phenylpropanoid pathway in cherry tomato fruit.

  20. c-Myc activates multiple metabolic networks to generate substrates for cell-cycle entry.

    Science.gov (United States)

    Morrish, F; Isern, N; Sadilek, M; Jeffrey, M; Hockenbery, D M

    2009-07-09

    Cell proliferation requires the coordinated activity of cytosolic and mitochondrial metabolic pathways to provide ATP and building blocks for DNA, RNA and protein synthesis. Many metabolic pathway genes are targets of the c-myc oncogene and cell-cycle regulator. However, the contribution of c-Myc to the activation of cytosolic and mitochondrial metabolic networks during cell-cycle entry is unknown. Here, we report the metabolic fates of [U-(13)C] glucose in serum-stimulated myc(-/-) and myc(+/+) fibroblasts by (13)C isotopomer NMR analysis. We demonstrate that endogenous c-myc increased (13)C labeling of ribose sugars, purines and amino acids, indicating partitioning of glucose carbons into C1/folate and pentose phosphate pathways, and increased tricarboxylic acid cycle turnover at the expense of anaplerotic flux. Myc expression also increased global O-linked N-acetylglucosamine protein modification, and inhibition of hexosamine biosynthesis selectively reduced growth of Myc-expressing cells, suggesting its importance in Myc-induced proliferation. These data reveal a central organizing function for the Myc oncogene in the metabolism of cycling cells. The pervasive deregulation of this oncogene in human cancers may be explained by its function in directing metabolic networks required for cell proliferation.

  1. Physical activity enhances metabolic fitness independently of cardiorespiratory fitness in marathon runners

    DEFF Research Database (Denmark)

    Laye, M J; Nielsen, M B; Hansen, L S

    2015-01-01

    High levels of cardiovascular fitness (CRF) and physical activity (PA) are associated with decreased mortality and risk to develop metabolic diseases. The independent contributions of CRF and PA to metabolic disease risk factors are unknown. We tested the hypothesis that runners who run...... consistently >50 km/wk and/or >2 marathons/yr for the last 5 years have superior metabolic fitness compared to matched sedentary subjects (CRF, age, gender, and BMI). Case-control recruitment of 31 pairs of runner-sedentary subjects identified 10 matched pairs with similar VO2max (mL/min/kg) (similar-VO2max......). The similar-VO2max group was compared with a group of age, gender, and BMI matched pairs who had the largest difference in VO2max (different-VO2max). Primary outcomes that defined metabolic fitness including insulin response to an oral glucose tolerance test, fasting lipids, and fasting insulin were superior...

  2. Metabolic activation of amygdala, lateral septum and accumbens circuits during food anticipatory behavior.

    Science.gov (United States)

    Olivo, Diana; Caba, Mario; Gonzalez-Lima, Francisco; Rodríguez-Landa, Juan F; Corona-Morales, Aleph A

    2017-01-01

    When food is restricted to a brief fixed period every day, animals show an increase in temperature, corticosterone concentration and locomotor activity for 2-3h before feeding time, termed food anticipatory activity. Mechanisms and neuroanatomical circuits responsible for food anticipatory activity remain unclear, and may involve both oscillators and networks related to temporal conditioning. Rabbit pups are nursed once-a-day so they represent a natural model of circadian food anticipatory activity. Food anticipatory behavior in pups may be associated with neural circuits that temporally anticipate feeding, while the nursing event may produce consummatory effects. Therefore, we used New Zealand white rabbit pups entrained to circadian feeding to investigate the hypothesis that structures related to reward expectation and conditioned emotional responses would show a metabolic rhythm anticipatory of the nursing event, different from that shown by structures related to reward delivery. Quantitative cytochrome oxidase histochemistry was used to measure regional brain metabolic activity at eight different times during the day. We found that neural metabolism peaked before nursing, during food anticipatory behavior, in nuclei of the extended amygdala (basolateral, medial and central nuclei, bed nucleus of the stria terminalis), lateral septum and accumbens core. After pups were fed, however, maximal metabolic activity was expressed in the accumbens shell, caudate, putamen and cortical amygdala. Neural and behavioral activation persisted when animals were fasted by two cycles, at the time of expected nursing. These findings suggest that metabolic activation of amygdala-septal-accumbens circuits involved in temporal conditioning may contribute to food anticipatory activity. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Understanding Fatty Acid Metabolism through an Active Learning Approach

    Science.gov (United States)

    Fardilha, M.; Schrader, M.; da Cruz e Silva, O. A. B.; da Cruz e Silva, E. F.

    2010-01-01

    A multi-method active learning approach (MALA) was implemented in the Medical Biochemistry teaching unit of the Biomedical Sciences degree at the University of Aveiro, using problem-based learning as the main learning approach. In this type of learning strategy, students are involved beyond the mere exercise of being taught by listening. Less…

  4. Negative Association of Domestic Activity and Active Commuting with Metabolic Syndrome in a Chinese Population Aged 35-64 Years.

    Science.gov (United States)

    Chen, Xiao Rong; Zhang, Jian; Ding, Gang Qiang; Dong, Zhong; Zhang, Xin Wei; Li, Jian Hong; Chen, Bo; Yan, Liu Xia; Mi, Sheng Quan; Zhao, Wen Hua

    2015-07-01

    To understand the associations of physical activity domains with metabolic syndrome among a middle-aged Chinese population. In all, 3326 professional adults aged 35-64 years from Beijing and Zhejiang province were recruited with a cluster random sampling method. The Global Physical Activity Questionnaire was modified, and the recommended Asia-Pacific cut-offs of waist circumstance were introduced into the criteria for metabolic syndrome from the Adult Treatment Panel III. A binary logistic regression model was applied to examine the association of all physical activity domains with the risk of the syndrome. Participants who engaged in domestic activity for ⋜1176 MET-min/week had a 41.6% less chance of having metabolic syndrome [odds ratio (OR), 0.584; 95% confidence interval (CI), 0.480-0.710] than those without this activity. In adjusted models, adults who actively commuted for ⋜33 MET-min/week but syndrome (OR, 0.750; 95% CI, 0.582-0.966) than those who did not. No interaction was detected between the two domains of activity and the syndrome. This study highlighted the independently negative association of traffic and house activity with the prevalence of the syndrome in this sample with a generally low level of moderate activity. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  5. The Subglacial Access and Fast Ice Research Experiment (SAFIRE): 1. Borehole-based englacial and subglacial measurements from a rapidly-moving tidewater glacier: Store Glacier, Greenland

    Science.gov (United States)

    Hubbard, Bryn; Doyle, Samuel; Christoffersen, Poul; Young, Tun Jan; Hofstede, Coen; Hubbard, Alun; Box, Jason; Todd, Joe; Bougamont, Marion

    2016-04-01

    As part of the Subglacial Access and Fast Ice Research Experiment (SAFIRE) pressurised hot water was used to drill four 603-616 m-long boreholes to the bed of the Greenland Ice Sheet at a site located 30 km from the calving front of fast-flowing, marine-terminating Store Glacier (70 degrees N, ~1000 m elevation). Four wired sensor strings were successfully installed in three of the boreholes. These included a thermistor string to obtain the englacial temperature profile installed in the same borehole as a string of tilt sensors to measure borehole deformation, and two sets of combined water pressure, electrical conductivity and turbidity sensors installed just above the bed in separate, adjacent boreholes. The boreholes made a strong hydrological connection to the bed during drilling, draining rapidly to ~80 m below the ice surface. The connection of subsequent boreholes was observed as a perturbation in water pressure and temperature recorded in neighbouring boreholes, indicating an effective hydrological connection between them. The sensors, which were wired to data-loggers at the surface, operated for between ~30 and >80 days from late summer into autumn before the cables stretched and snapped, with the lowermost sensors failing first. The records obtained from these sensors reveal (i) subglacial water pressures that were close to overburden but which generally increased through the period of measurement and varied diurnally by ~0.3 m, (ii) a minimum englacial temperature of -21 degrees C underlain by a zone of temperate ice, some tens of m thick, located immediately above the bed, and (iii) high rates of internal deformation and strain that increased towards the bed. These borehole observations are complemented by GPS measurements of ice motion, meteorological data, and seismic and radar surveys.

  6. Metabolic Control of Dendritic Cell Activation and Function: Recent Advances and Clinical Implications

    Directory of Open Access Journals (Sweden)

    Bart eEverts

    2014-05-01

    Full Text Available Dendritic cells (DCs are key regulators of both immunity and tolerance by controlling activation and polarization of effector T helper cell and regulatory T cell responses. Therefore, there is a major focus on developing approaches to manipulate DC function for immunotherapy. It is well known that changes in cellular activation are coupled to profound changes in cellular metabolism. Over the past decade there is a growing appreciation that these metabolic changes also underlie the capacity of immune cells to perform particular functions. This has led to the concept that the manipulation of cellular metabolism can be used to shape innate and adaptive immune responses. While most of our understanding in this area has been gained from studies with T cells and macrophages, evidence is emerging that the activation and function of DCs are also dictated by the type of metabolism these cells commit to. We here discuss these new insights and explore whether targeting of metabolic pathways in DCs could hold promise as a novel approach to manipulate the functional properties of DCs for clinical purposes.

  7. Metabolic features of Protochlamydia amoebophila elementary bodies--a link between activity and infectivity in Chlamydiae.

    Directory of Open Access Journals (Sweden)

    Barbara S Sixt

    Full Text Available The Chlamydiae are a highly successful group of obligate intracellular bacteria, whose members are remarkably diverse, ranging from major pathogens of humans and animals to symbionts of ubiquitous protozoa. While their infective developmental stage, the elementary body (EB, has long been accepted to be completely metabolically inert, it has recently been shown to sustain some activities, including uptake of amino acids and protein biosynthesis. In the current study, we performed an in-depth characterization of the metabolic capabilities of EBs of the amoeba symbiont Protochlamydia amoebophila. A combined metabolomics approach, including fluorescence microscopy-based assays, isotope-ratio mass spectrometry (IRMS, ion cyclotron resonance Fourier transform mass spectrometry (ICR/FT-MS, and ultra-performance liquid chromatography mass spectrometry (UPLC-MS was conducted, with a particular focus on the central carbon metabolism. In addition, the effect of nutrient deprivation on chlamydial infectivity was analyzed. Our investigations revealed that host-free P. amoebophila EBs maintain respiratory activity and metabolize D-glucose, including substrate uptake as well as host-free synthesis of labeled metabolites and release of labeled CO2 from (13C-labeled D-glucose. The pentose phosphate pathway was identified as major route of D-glucose catabolism and host-independent activity of the tricarboxylic acid (TCA cycle was observed. Our data strongly suggest anabolic reactions in P. amoebophila EBs and demonstrate that under the applied conditions D-glucose availability is essential to sustain metabolic activity. Replacement of this substrate by L-glucose, a non-metabolizable sugar, led to a rapid decline in the number of infectious particles. Likewise, infectivity of Chlamydia trachomatis, a major human pathogen, also declined more rapidly in the absence of nutrients. Collectively, these findings demonstrate that D-glucose is utilized by P. amoebophila

  8. The use of magmatic water to reconstruct palaeo-ice thicknesses during subglacial rhyolitic eruptions

    Science.gov (United States)

    Owen, Jacqueline; Tuffen, Hugh; McGarvie, Dave; Pinkerton, Harry; Wilson, Lionel

    2010-05-01

    Magma degassing patterns can potentially be used to reconstruct ice thicknesses during subglacial eruptions, as the pressure dependence of water solubility in silicate melts is reasonably well constrained. The amount of water remaining in the quenched bulk glasses should record the quenching pressure, which, in a subglacial setting, will be dependent on the pressure of overlying ice and/or meltwater that was present. This reconstruction technique has been applied to several basaltic volcanoes[1]. In one study the dissolved water contents was seen to vary as a function of altitude, consistent with the presence of an ice sheet[2]. Similar techniques have been applied to a rhyolitic volcano, as described below. Bláhnúkur is a small-volume rhyolitic, subglacial volcano at Torfajökull volcano, southern Iceland[3] that erupted at ~95 ka[4]. 45 glassy lava samples were collected from a variety of elevations and lithofacies types. These samples were analysed for water content using infra-red spectroscopy (FTIR), and pressure-solubility relationships were calculated using VolatileCalc[5]. The results reveal a general decrease in water concentration with elevation, consistent with the presence of an ice sheet with a surface elevation of ~1,050 m a.s.l.. This corresponds with an ice thickness of ~450 m, consistent with the field evidence from tuyas of a similar age within the same region[6]. Furthermore, the results suggest an eruptive temperature of 850°C and 0 ppm CO2. However, not all samples agree with this overall trend. We suggest that samples with anomalously low water contents could have formed in regions where there was meltwater drainage which lowered the quenching pressure[7]. By contrast, water-rich samples could reflect intrusive formation resulting in loading by rock as well as ice[8]. Crucially though, the anomalous values are all from the same locations, suggesting that there are processes that are specifically affecting certain localities. In order to use

  9. Biological Activity of Vegetal Extracts Containing Phenols on Plant Metabolism

    Directory of Open Access Journals (Sweden)

    Andrea Ertani

    2016-02-01

    Full Text Available The influence of vegetal extracts derived from red grape, blueberry fruits and hawthorn leaves on Zea mays L. plant growth and the activity of phenylalanine ammonia-lyase (PAL, a key enzyme of the phenylpropanoid pathway, was investigated in laboratory experiments. The extracts were characterized using FT-IR and Raman spectroscopies in order to obtain a pattern of the main functional groups. In addition, phenols content was determined by HPLC, whereas the content of indoleacetic acid and isopentenyladenosine hormones was determined by ELISA test and the auxin and gibberellin-like activities by plant-bioassays. The treated maize revealed increased root and leaf biomass, chlorophyll and sugars content with respect to untreated plants. Hawthorn, red grape skin and blueberry at 1.0 mL/L induced high p-coumaric content values, whilst hawthorn also showed high amounts of gallic and p-hydroxybenzoic acids. PAL activity induced by hawthorn at 1.0 mL/L had the highest values (11.1-fold UNT and was strongly and linearly related with the sum of leaf phenols. Our results suggest that these vegetal extracts contain more than one group of plant-promoting substances.

  10. Biological Activity of Vegetal Extracts Containing Phenols on Plant Metabolism.

    Science.gov (United States)

    Ertani, Andrea; Pizzeghello, Diego; Francioso, Ornella; Tinti, Anna; Nardi, Serenella

    2016-02-08

    The influence of vegetal extracts derived from red grape, blueberry fruits and hawthorn leaves on Zea mays L. plant growth and the activity of phenylalanine ammonia-lyase (PAL), a key enzyme of the phenylpropanoid pathway, was investigated in laboratory experiments. The extracts were characterized using FT-IR and Raman spectroscopies in order to obtain a pattern of the main functional groups. In addition, phenols content was determined by HPLC, whereas the content of indoleacetic acid and isopentenyladenosine hormones was determined by ELISA test and the auxin and gibberellin-like activities by plant-bioassays. The treated maize revealed increased root and leaf biomass, chlorophyll and sugars content with respect to untreated plants. Hawthorn, red grape skin and blueberry at 1.0 mL/L induced high p-coumaric content values, whilst hawthorn also showed high amounts of gallic and p-hydroxybenzoic acids. PAL activity induced by hawthorn at 1.0 mL/L had the highest values (11.1-fold UNT) and was strongly and linearly related with the sum of leaf phenols. Our results suggest that these vegetal extracts contain more than one group of plant-promoting substances.

  11. The Effects of Weight Loss Versus Weight Loss Maintenance on Sympathetic Nervous System Activity and Metabolic Syndrome Components

    National Research Council Canada - National Science Library

    Straznicky, Nora E; Grima, Mariee T; Eikelis, Nina; Nestel, Paul J; Dawood, Tye; Schlaich, Markus P; Chopra, Reena; Masuo, Kazuko; Esler, Murray D; Sari, Carolina I; Lambert, Gavin W; Lambert, Elisabeth A

    2011-01-01

    This study demonstrates divergent effects of successful weight loss maintenance on whole body norepinephrine spillover rate and muscle sympathetic nerve activity in obese metabolic syndrome subjects. Context...

  12. Short term exposure to elevated levels of leptin reduces proximal tubule cell metabolic activity.

    Science.gov (United States)

    Briffa, Jessica F; Grinfeld, Esther; McAinch, Andrew J; Poronnik, Philip; Hryciw, Deanne H

    2014-01-25

    Leptin plays a pathophysiological role in the kidney, however, its acute effects on the proximal tubule cells (PTCs) are unknown. In opossum kidney (OK) cells in vitro, Western blot analysis identified that exposure to leptin increases the phosphorylation of the mitogen-activated protein kinase (MAPK) p44/42 and the mammalian target of rapamycin (mTOR). Importantly leptin (0.05, 0.10, 0.25 and 0.50 μg/ml) significantly reduced the metabolic activity of PTCs, and significantly decreased protein content per cell. Investigation of the role of p44/42 and mTOR on metabolic activity and protein content per cell, demonstrated that in the presence of MAPK inhibitor U0126 and mTOR inhibitor Ku-63794, that the mTOR pathway is responsible for the reduction in PTC metabolic activity in response to leptin. However, p44/42 and mTOR play no role the reduced protein content per cell in OKs exposed to leptin. Therefore, leptin modulates metabolic activity in PTCs via an mTOR regulated pathway. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  13. Independent and combined influence of physical activity and perceived stress on the metabolic syndrome in male law enforcement officers.

    Science.gov (United States)

    Yoo, Hye Lim; Eisenmann, Joey C; Franke, Warren D

    2009-01-01

    : To examine the independent and combined interrelationships among physical activity, perceived stress, and the metabolic syndrome in law enforcement officers (LEOs). : Perceived stress, self-reported physical activity, and metabolic syndrome risk factors were assessed in 386 white male LEOs. : Among the LEOs, 23.1% had the metabolic syndrome. The metabolic syndrome was not significantly associated with perceived stress (r = 0.047) whereas physical activity was (r = -0.225, P metabolic syndrome in the low and moderate physical activity groups compared to the high physical activity group were 3.13 (95% CI = 1.56 to 6.26) and 2.30 (95% CI = 1.29 to 4.09), respectively. : Regardless of stress level, physical inactivity is an important risk factor in the metabolic syndrome among this unique occupational group.

  14. Intensity of bouted and sporadic physical activity and the metabolic syndrome in adults.

    Science.gov (United States)

    Robson, Jordan; Janssen, Ian

    2015-01-01

    Background. Physical activity guidelines for adults only recognize the health benefits of accumulating bouted moderate-to-vigorous physical activity (MVPA), or MVPA occurring over at least 10 consecutive minutes. There is a lack of evidence supporting the health benefits of other patterns and intensities of activity including sporadic MVPA (i.e., MVPA occurring in periods of fewer than 10 consecutive minutes) and light intensity physical activity (LIPA). The objective of this study was to examine the health benefits associated with physical activity that does not meet the physical activity guidelines criteria for bouted MVPA. Specifically, we examined the association between sporadic MVPA and bouted and sporadic LIPA with the metabolic syndrome. Methods. We studied a representative cross-sectional sample of 1,974 adults aged 20 years and older from the 2003-2006 US National Health and Nutrition Examination Survey. Physical activity was measured over 7 days using Actigraph AM-7164 accelerometers. Each minute over the 7-day measurement period was classified as being of a sedentary, light, or moderate-to-vigorous intensity. A 10 min threshold differentiated bouted activity from sporadic activity. Average minutes/day of sporadic LIPA, sporadic MVPA, bouted LIPA, bouted MVPA, and embedded MVPA (MVPA occurring within bouts of primarily LIPA) were calculated. Metabolic syndrome status was determined using established criteria. Associations were examined using logistic regression and controlled for relevant covariates. Results. For every 30 min/day of physical activity, the odds ratio (95% confidence interval) of the metabolic syndrome was reduced by 4% (1-7%) for bouted LIPA, 64% (51-71%) for bouted MVPA, and 57% (45-67%) for embedded MVPA. Sporadic LIPA was not independently associated with the metabolic syndrome. We could not examine the association between sporadic MVPA and the metabolic syndrome because participants accumulated such a marginal amount of this type of

  15. Intensity of bouted and sporadic physical activity and the metabolic syndrome in adults

    Directory of Open Access Journals (Sweden)

    Jordan Robson

    2015-11-01

    Full Text Available Background. Physical activity guidelines for adults only recognize the health benefits of accumulating bouted moderate-to-vigorous physical activity (MVPA, or MVPA occurring over at least 10 consecutive minutes. There is a lack of evidence supporting the health benefits of other patterns and intensities of activity including sporadic MVPA (i.e., MVPA occurring in periods of fewer than 10 consecutive minutes and light intensity physical activity (LIPA. The objective of this study was to examine the health benefits associated with physical activity that does not meet the physical activity guidelines criteria for bouted MVPA. Specifically, we examined the association between sporadic MVPA and bouted and sporadic LIPA with the metabolic syndrome.Methods. We studied a representative cross-sectional sample of 1,974 adults aged 20 years and older from the 2003–2006 US National Health and Nutrition Examination Survey. Physical activity was measured over 7 days using Actigraph AM-7164 accelerometers. Each minute over the 7-day measurement period was classified as being of a sedentary, light, or moderate-to-vigorous intensity. A 10 min threshold differentiated bouted activity from sporadic activity. Average minutes/day of sporadic LIPA, sporadic MVPA, bouted LIPA, bouted MVPA, and embedded MVPA (MVPA occurring within bouts of primarily LIPA were calculated. Metabolic syndrome status was determined using established criteria. Associations were examined using logistic regression and controlled for relevant covariates.Results. For every 30 min/day of physical activity, the odds ratio (95% confidence interval of the metabolic syndrome was reduced by 4% (1–7% for bouted LIPA, 64% (51–71% for bouted MVPA, and 57% (45–67% for embedded MVPA. Sporadic LIPA was not independently associated with the metabolic syndrome. We could not examine the association between sporadic MVPA and the metabolic syndrome because participants accumulated such a marginal amount

  16. Metabolic syndrome and type 2 diabetes mellitus: focus on peroxisome proliferator activated receptors (PPAR

    Directory of Open Access Journals (Sweden)

    Fisman Enrique Z

    2003-03-01

    Full Text Available Abstract The metabolic syndrome is a highly prevalent clinical entity. The recent Adult Treatment Panel (ATP III guidelines have called specific attention to the importance of targeting the cardiovascular risk factors of the metabolic syndrome as a method of risk reduction therapy. The main factors characteristic of this syndrome are abdominal obesity, atherogenic dyslipidemia, elevated blood pressure, insulin resistance (with or without glucose intolerance, prothrombotic and proinflammatory states. An insulin resistance following nuclear peroxisome proliferator activated receptors (PPAR deactivation (mainly obesity-related is the key phase of metabolic syndrome initiation. Afterwards, there are 2 principal pathways of metabolic syndrome development: 1 with preserved pancreatic beta cells function and insulin hypersecretion which can compensate for insulin resistance. This pathway leads mainly to the macrovascular complications of metabolic syndrome; 2 with massive damage of pancreatic beta cells leading to progressively decrease of insulin secretion and to hyperglycemia (e.g. overt type 2 diabetes. This pathway leads to both microvascular and macrovascular complications. We suggest that a PPAR-based appraisal of metabolic syndrome and type 2 diabetes may improve our understanding of these diseases and set a basis for a comprehensive approach in their treatment.

  17. Small scale high resolution LiDAR measurements of a subglacial conduit

    Science.gov (United States)

    Mankoff, K. D.; Gulley, J.

    2012-04-01

    We present direct measurements of surface roughness in a sub-glacial conduit system underneath the Rieperbreen Glacier, Svalbard, Norway. Data was collected with a low-cost (129 USD) Microsoft Kinect video game device used as a LIDAR sensor. Surface roughness is a primary control on water flow in rivers, channels, and cave conduit systems and understanding the effects of surface roughness on water flow has been problematic due to lack of direct measurements of roughness in natural systems. We use the ice scallop dimensions to derive flow velocity and explore implications of the changing roughness parameters as the cave grows and shrinks.

  18. Photogrammetric recognition of subglacial drainage channels during glacier lake outburst events

    Science.gov (United States)

    Schwalbe, Ellen; Koschitzki, Robert

    2016-04-01

    In recent years, many glaciers all over the world have been distinctly retreating and thinning. One of the consequences of this is the increase of so called glacier lake outburst flood events (GLOFs): Lakes that have been dammed by a glacier spontaneously start to drain through a subglacial channel underneath the glacier due to their outweighing hydrostatic pressure. In a short period of time, the lake water drains under the glacier and causes floods in downstream valleys. In many cases the latter become hazardous for people and their property. Due to glacier movement, the tunnel will soon collapse, and the glacier lake refills, thus starting a new GLOF cycle. The mechanisms ruling GLOF events are yet still not fully understood by glaciologists. Thus, there is a demand for data and measurement values that can help to understand and model the phenomena. In view of the above, we will show how photogrammetric image sequence analysis can be used to collect data which allows for drawing conclusions about the location and development of a subglacial channel. The work is a follow-up on earlier work on a photogrammetric GLOF early warning system (Mulsow et. al., 2013). For the purpose of detecting the subglacial tunnel, a camera has been installed in a pilot study to observe the area of the Colonia glacier (Northern Patagonian ice field) where it dams the lake Lago Cachet II. To verify the hypothesis, that the course of the subglacial tunnel is indicated by irregular surface motion patterns during its collapse, the camera acquired image sequences of the glacier surface during several GLOF events. Applying LSM-based tracking techniques to these image sequences, surface feature motion trajectories could be obtained for a dense raster of glacier points. Since only a single camera has been used for image sequence acquisition, depth information is required to scale the trajectories. Thus, for scaling and georeferencing of the measurements a GPS-supported photogrammetric network

  19. Physical activity, ethnicity and cardio-metabolic health: does one size fit all?

    Science.gov (United States)

    Gill, Jason M R; Celis-Morales, Carlos A; Ghouri, Nazim

    2014-02-01

    A large and consistent body of epidemiological evidence indicates that low levels of physical activity, low levels of cardiorespiratory fitness and high levels of sedentary behaviour are associated with increased risk of cardio-metabolic diseases. However, most such studies have been undertaken in populations of White European descent. The available data from non-White populations suggests that physical activity is also protective in these groups, but the threshold level of activity needed to confer low risk, particularly for type 2 diabetes, may not be the same across all ethnic groups. In patients with impaired glucose regulation, lifestyle interventions, including physical activity as a component (often in combination with weight loss), are effective at reducing risk of incident diabetes across a range of ethnic groups. However, the optimal levels of physical activity for prevention of diabetes and cardiovascular disease amongst the general populations of different ethnic groups have not been firmly established. Emerging data suggest that innate differences in cardiorespiratory fitness levels and capacity for fat oxidation potentially contribute to ethnic differences in the cardio-metabolic risk profile and that ethnicity-specific physical activity guidelines may be conceptually warranted. More study is needed to understand how and why the dose-response relationship between physical activity and cardio-metabolic risk differs according to ethnicity and to determine the best approaches to promote physical activity in non-White ethnic groups. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. AMP-Activated Protein Kinase Connects Cellular Energy Metabolism to KATP Channel Function

    Science.gov (United States)

    Yoshida, Hidetada; Bao, Li; Kefalogianni, Eirini; Taskin, Eylem; Okorie, Uzoma; Hong, Miyoun; Dhar-Chowdhury, Piyali; Kaneko, Michiyo; Coetzee, William A.

    2011-01-01

    AMPK is an important sensor of cellular energy levels. Objective The aim of these studies was to investigate whether cardiac KATP channels, which couple cellular energy metabolism to membrane excitability, are regulated by AMPK activity. Research Design and Methods We investigated effects of AMPK on rat ventricular KATP channels using electrophysiological and biochemical approaches Results Whole-cell KATP channel current was activated by metabolic inhibition; this occurred more rapidly in the presence of AICAR (an AMPK activator). AICAR had no effects on KATP channel activity recorded in the inside-out patch clamp configuration, but ZMP (the intracellular intermediate of AICAR) strongly activated KATP channels. An AMPK-mediated effect is demonstrated by the finding that ZMP had no effect on KATP channels in the presence of Compound C (an AMPK inhibitor). Recombinant AMPK activated Kir6.2/SUR2A channels in a manner that was dependent on the AMP concentration, whereas heat-inactivated AMPK was without effect. Using mass-spectrometry and co-immunoprecipitation approaches, we demonstrate that the AMPK α-subunit physically associates with KATP channel subunits. Conclusions Our data demonstrate that the cardiac KATP channel function is directly regulated by AMPK activation. During metabolic stress, a small change in cellular AMP that activates AMPK can be a potential trigger for KATP channel opening. PMID:21888913

  1. The role of active brown adipose tissue in human metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Ozguven, Salih; Turoglu, H.T. [S.B. Marmara Universitesi Pendik Egitim ve Arastirma Hastanesi, Department of Nuclear Medicine, Istanbul (Turkey); Ones, Tunc [S.B. Marmara Universitesi Pendik Egitim ve Arastirma Hastanesi, Department of Nuclear Medicine, Istanbul (Turkey); Kozyatagi/Kadikoy, Istanbul (Turkey); Yilmaz, Yusuf; Imeryuz, Nese [S.B. Marmara Universitesi Pendik Egitim ve Arastirma Hastanesi, Department of Internal Medicine, Division of Gastroenterology, Istanbul (Turkey)

    2016-02-15

    The presence of activated brown adipose tissue (ABAT) has been associated with a reduced risk of obesity in adults. We aimed to investigate whether the presence of ABAT in patients undergoing {sup 18}F-FDG PET/CT examinations was related to blood lipid profiles, liver function, and the prevalence of non-alcoholic fatty liver disease (NAFLD). We retrospectively and prospectively analysed the {sup 18}F-FDG PET/CT scans from 5,907 consecutive patients who were referred to the Nuclear Medicine Department of the Marmara University School of Medicine from outpatient oncology clinics between July 2008 and June 2014 for a variety of diagnostic reasons. Attenuation coefficients for the liver and spleen were determined for at least five different areas. Blood samples were obtained before PET/CT to assess the blood lipid profiles and liver function. A total of 25 of the 5,907 screened individuals fulfilling the inclusion criteria for the study demonstrated brown fat tissue uptake [ABAT(+) subjects]. After adjustment for potential confounders, 75 individuals without evidence of ABAT on PET [ABAT(-) subjects] were enrolled for comparison purposes. The ABAT(+) group had lower total cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, and aspartate transaminase levels (p < 0.01), whereas we found no significant differences in the serum triglyceride and high-density lipoprotein cholesterol levels between the two groups. The prevalence of NAFLD was significantly lower in ABAT(+) than in ABAT(-) subjects (p < 0.01). Our study showed that the presence of ABAT in adults had a positive effect on their blood lipid profiles and liver function and was associated with reduced prevalence of NAFLD. Thus, our data suggest that activating brown adipose tissue may be a potential target for preventing and treating dyslipidaemia and NAFLD. (orig.)

  2. Simultaneous water activation and glucose metabolic rate imaging with PET.

    Science.gov (United States)

    Verhaeghe, Jeroen; Reader, Andrew J

    2013-02-07

    A novel imaging and signal separation strategy is proposed to be able to separate [(18)F]FDG and multiple [(15)O]H(2)O signals from a simultaneously acquired dynamic PET acquisition of the two tracers. The technique is based on the fact that the dynamics of the two tracers are very distinct. By adopting an appropriate bolus injection strategy and by defining tailored sets of basis functions that model either the FDG or water component, it is possible to separate the FDG and water signal. The basis functions are inspired from the spectral analysis description of dynamic PET studies and are defined as the convolution of estimated generating functions (GFs) with a set of decaying exponential functions. The GFs are estimated from the overall measured head curve, while the decaying exponential functions are pre-determined. In this work, the time activity curves (TACs) are modelled post-reconstruction but the model can be incorporated in a global 4D reconstruction strategy. Extensive PET simulation studies are performed considering single [(18)F]FDG and 6 [(15)O]H(2)O bolus injections for a total acquisition time of 75 min. The proposed method is evaluated at multiple noise levels and different parameters were estimated such as [(18)F]FDG uptake and blood flow estimated from the [(15)O]H(2)O component, requiring a full dynamic analysis of the two components, static images of [(18)F]FDG and the water components as well as [(15)O]H(2)O activation. It is shown that the resulting images and parametric values in ROIs are comparable to images obtained from separate imaging, illustrating the feasibility of simultaneous imaging of [(18)F]FDG and [(15)O]H(2)O components.

  3. Polyphenols from Bee Pollen: Structure, Absorption, Metabolism and Biological Activity

    Directory of Open Access Journals (Sweden)

    Anna Rzepecka-Stojko

    2015-12-01

    Full Text Available Bee pollen constitutes a natural source of antioxidants such as phenolic acids and flavonoids, which are responsible for its biological activity. Research has indicated the correlation between dietary polyphenols and cardioprotective, hepatoprotective, anti-inflammatory, antibacterial, anticancerogenic, immunostimulating, antianaemic effects, as well as their beneficial influence on osseous tissue. The beneficial effects of bee pollen on health result from the presence of phenolic acids and flavonoids which possess anti-inflammatory properties, phytosterol and linolenic acid which play an anticancerogenic role, and polysaccharides which stimulate immunological activity. Polyphenols are absorbed in the alimentary tract, metabolised by CYP450 enzymes, and excreted with urine and faeces. Flavonoids and phenolic acids are characterised by high antioxidative potential, which is closely related to their chemical structure. The high antioxidant potential of phenolic acids is due to the presence and location of hydroxyl groups, a carboxyl group in the immediate vicinity of ortho-diphenolic substituents, and the ethylene group between the phenyl ring and the carboxyl group. As regards flavonoids, essential structural elements are hydroxyl groups at the C5 and C7 positions in the A ring, and at the C3′ and C4′ positions in the B ring, and a hydroxyl group at the C3 position in the C ring. Furthermore, both, the double bond between C2 and C3, and a ketone group at the C4 position in the C ring enhance the antioxidative potential of these compounds. Polyphenols have an ideal chemical structure for scavenging free radicals and for creating chelates with metal ions, which makes them effective antioxidants in vivo.

  4. Polyphenols from Bee Pollen: Structure, Absorption, Metabolism and Biological Activity.

    Science.gov (United States)

    Rzepecka-Stojko, Anna; Stojko, Jerzy; Kurek-Górecka, Anna; Górecki, Michał; Kabała-Dzik, Agata; Kubina, Robert; Moździerz, Aleksandra; Buszman, Ewa

    2015-12-04

    Bee pollen constitutes a natural source of antioxidants such as phenolic acids and flavonoids, which are responsible for its biological activity. Research has indicated the correlation between dietary polyphenols and cardioprotective, hepatoprotective, anti-inflammatory, antibacterial, anticancerogenic, immunostimulating, antianaemic effects, as well as their beneficial influence on osseous tissue. The beneficial effects of bee pollen on health result from the presence of phenolic acids and flavonoids which possess anti-inflammatory properties, phytosterol and linolenic acid which play an anticancerogenic role, and polysaccharides which stimulate immunological activity. Polyphenols are absorbed in the alimentary tract, metabolised by CYP450 enzymes, and excreted with urine and faeces. Flavonoids and phenolic acids are characterised by high antioxidative potential, which is closely related to their chemical structure. The high antioxidant potential of phenolic acids is due to the presence and location of hydroxyl groups, a carboxyl group in the immediate vicinity of ortho-diphenolic substituents, and the ethylene group between the phenyl ring and the carboxyl group. As regards flavonoids, essential structural elements are hydroxyl groups at the C5 and C7 positions in the A ring, and at the C3' and C4' positions in the B ring, and a hydroxyl group at the C3 position in the C ring. Furthermore, both, the double bond between C2 and C3, and a ketone group at the C4 position in the C ring enhance the antioxidative potential of these compounds. Polyphenols have an ideal chemical structure for scavenging free radicals and for creating chelates with metal ions, which makes them effective antioxidants in vivo.

  5. Bone metabolic activity in hyperostosis cranialis interna measured with {sup 18}F-fluoride PET

    Energy Technology Data Exchange (ETDEWEB)

    Waterval, Jerome J.; Dongen, Thijs M.A. van; Stokroos, Robert J.; Manni, Johannes J. [Maastricht University Medical Center, Department of Otorhinolaryngology and Head and Neck Surgery, Maastricht (Netherlands); Teule, Jaap G.J.; Kemerink, Gerrit J.; Brans, Boudewijn [Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Nieman, Fred H.M. [Maastricht University Medical Center, Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht (Netherlands)

    2011-05-15

    {sup 18}F-Fluoride PET/CT is a relatively undervalued diagnostic test to measure bone metabolism in bone diseases. Hyperostosis cranialis interna (HCI) is a (hereditary) bone disease characterised by endosteal hyperostosis and osteosclerosis of the skull and the skull base. Bone overgrowth causes entrapment and dysfunction of several cranial nerves. The aim of this study is to compare standardised uptake values (SUVs) at different sites in order to quantify bone metabolism in the affected anatomical regions in HCI patients. Nine affected family members, seven non-affected family members and nine non-HCI non-family members underwent {sup 18}F-fluoride PET/CT scans. SUVs were systematically measured in the different regions of interest: frontal bone, sphenoid bone, petrous bone and clivus. Moreover, the average {sup 18}F-fluoride uptake in the entire skull was measured by assessing the uptake in axial slides. Visual assessment of the PET scans of affected individuals was performed to discover the process of disturbed bone metabolism in HCI. {sup 18}F-Fluoride uptake is statistically significantly higher in the sphenoid bone and clivus regions of affected family members. Visual assessment of the scans of HCI patients is relevant in detecting disease severity and the pattern of disturbed bone metabolism throughout life. {sup 18}F-Fluoride PET/CT is useful in quantifying the metabolic activity in HCI and provides information about the process of disturbed bone metabolism in this specific disorder. Limitations are a narrow window between normal and pathological activity and the influence of age. This study emphasises that {sup 18}F-fluoride PET/CT may also be a promising diagnostic tool for other metabolic bone disorders, even those with an indolent course. (orig.)

  6. Temperature, field activity and post-feeding metabolic response in the Asian house gecko, Hemidactylus frenatus.

    Science.gov (United States)

    Lei, Juan; Booth, David T

    2014-10-01

    Temperature has significant effects on physiological activities and geographical distribution of ectotherms. The Asian house gecko Hemidactylus frenatus has become one of the most widely distributed reptiles in the world and is an invasive species in Australia. Since being introduced into northern Australia, Asian house geckos have spread rapidly and expanded into south-east Queensland and northern New South Wales. Despite their rapid spread, there have been few studies that address thermal adaptability of this species. In order to understand how temperature might limit the distribution and feeding behavior of H. frenatus we observed gecko foraging activities in the wild over the winter period, measured the temperature at which voluntary feeding ceases, and assessed the effect of temperature (30, 25, 20, and 18 °C) on post-feeding metabolic rate. Resting metabolic rate and post-feeding peak in metabolic rate decreased with low temperature, while the duration of elevated metabolic rate after feeding increased at lower temperature. The SDA coefficient (a ratio of the energy expended due to the post-feeding rise in metabolic rate to the energy contained within the meal) did not change systematically with ambient temperature. Field observations and voluntary feeding experiments showed that H. frenatus stop feeding when ambient temperature drops below 17 °C, so that persistent night time temperatures below 17 °C may be limiting the distribution of this species. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Metabolic activity and enzyme induction in rat fecal microflora maintained in continuous culture.

    Science.gov (United States)

    Mallett, A K; Bearne, C A; Rowland, I R

    1983-01-01

    The enzyme activity of the rat hindgut microflora maintained in an anaerobic two-stage continuous culture was compared with that of rat cecal contents. A qualitative comparison (API ZYM) showed a high degree of similarity between the two populations. Quantitative determinations showed that azoreductase, beta-glucosidase, nitrate reductase, and nitroreductase activities were comparable, and that beta-glucuronidase activity was very low in the culture. beta-Glucuronidase, beta-glucosidase, and nitrate reductase activities were induced within the culture by their respective substrates. Bile acids influenced microbial activity in vitro, with cholic acid inducing beta-glucosidase, azoreductase, and beta-glucuronidase activities and decreasing nitrate reductase activity. Chenodeoxycholic acid increased beta-glucosidase and beta-glucuronidase activities and decreased azoreductase, nitrate reductase, and nitroreductase activities in vitro. These studies demonstrate that the rat hindgut microflora may be successfully cultured in vitro and suggest control mechanisms that regulate the metabolic activity of these organisms in vivo. PMID:6416166

  8. Metabolomics-Based Elucidation of Active Metabolic Pathways in Erythrocytes and HSC-Derived Reticulocytes.

    Science.gov (United States)

    Srivastava, Anubhav; Evans, Krystal J; Sexton, Anna E; Schofield, Louis; Creek, Darren J

    2017-04-07

    A detailed analysis of the metabolic state of human-stem-cell-derived erythrocytes allowed us to characterize the existence of active metabolic pathways in younger reticulocytes and compare them to mature erythrocytes. Using high-resolution LC-MS-based untargeted metabolomics, we found that reticulocytes had a comparatively much richer repertoire of metabolites, which spanned a range of metabolite classes. An untargeted metabolomics analysis using stable-isotope-labeled glucose showed that only glycolysis and the pentose phosphate pathway actively contributed to the biosynthesis of metabolites in erythrocytes, and these pathways were upregulated in reticulocytes. Most metabolite species found to be enriched in reticulocytes were residual pools of metabolites produced by earlier erythropoietic processes, and their systematic depletion in mature erythrocytes aligns with the simplification process, which is also seen at the cellular and the structural level. Our work shows that high-resolution LC-MS-based untargeted metabolomics provides a global coverage of the biochemical species that are present in erythrocytes. However, the incorporation of stable isotope labeling provides a more accurate description of the active metabolic processes that occur in each developmental stage. To our knowledge, this is the first detailed characterization of the active metabolic pathways of the erythroid lineage, and it provides a rich database for understanding the physiology of the maturation of reticulocytes into mature erythrocytes.

  9. Physical activity, metabolic syndrome, and coronary risk: the EPIC-Norfolk prospective population study

    NARCIS (Netherlands)

    Broekhuizen, Lysette N.; Boekholdt, S. Matthijs; Arsenault, Benoit J.; Despres, Jean-Pierre; Stroes, Erik S. G.; Kastelein, John J. P.; Khaw, Kay-Tee; Wareham, Nicholas J.

    2011-01-01

    Objective: We investigated the association between physical activity, metabolic syndrome (MS), and the risk of future coronary heart disease (CHD) and mortality due to CHD in middle-aged men and women. Design: Prospective cohort study. Subjects: A total of 10,134 men and women aged 45-79 years at

  10. Physical activity, physical fitness, gross motor coordination, and metabolic syndrome: focus of twin research in Portugal.

    Science.gov (United States)

    Maia, José António Ribeiro; Santos, Daniel; de Freitas, Duarte Luis; Thomis, Martine

    2013-02-01

    A very brief history of Portuguese twin research in sport and human movement sciences is presented. Recruitment procedures, zygosity determination, and phenotypes are given for twins and their parents from the mainland, and Azores and Madeira archipelagos. Preliminary findings are mostly related to physical activity, health-related physical fitness, gross motor coordination, neuromotor development, and metabolic syndrome traits.

  11. Biotransformation of anthelmintics and the activity of drug-metabolizing enzymes in the tapeworm Moniezia expansa.

    Science.gov (United States)

    Prchal, Lukáš; Bártíková, Hana; Bečanová, Aneta; Jirásko, Robert; Vokřál, Ivan; Stuchlíková, Lucie; Skálová, Lenka; Kubíček, Vladimír; Lamka, Jiří; Trejtnar, František; Szotáková, Barbora

    2015-04-01

    The sheep tapeworm Moniezia expansa is very common parasite, which affects ruminants such as sheep, goats as well as other species. The benzimidazole anthelmintics albendazole (ABZ), flubendazole (FLU) and mebendazole (MBZ) are often used to treat the infection. The drug-metabolizing enzymes of helminths may alter the potency of anthelmintic treatment. The aim of our study was to assess the activity of the main drug-metabolizing enzymes and evaluate the metabolism of selected anthelmintics (ABZ, MBZ and FLU) in M. expansa. Activities of biotransformation enzymes were determined in subcellular fractions. Metabolites of the anthelmintics were detected and identified using high performance liquid chromatography/ultra-violet/VIS/fluorescence or ultra-high performance liquid chromatography/mass spectrometry. Reduction of MBZ, FLU and oxidation of ABZ were proved as well as activities of various metabolizing enzymes. Despite the fact that the conjugation enzymes glutathione S-transferase, UDP-glucuronosyl transferase and UDP-glucosyl transferase were active in vitro, no conjugated metabolites of anthelmintics were identified either ex vivo or in vitro. The obtained results indicate that sheep tapeworm is able to deactivate the administered anthelmintics, and thus protects itself against their action.

  12. Mutagenicity of silver nanoparticles in CHO cells dependent on particle surface functionalization and metabolic activation

    Science.gov (United States)

    Guigas, Claudia; Walz, Elke; Gräf, Volker; Heller, Knut J.; Greiner, Ralf

    2017-06-01

    The potential of engineered nanomaterials to induce genotoxic effects is an important aspect of hazard identification. In this study, cytotoxicity and mutagenicity as a function of metabolic activation of three silver nanoparticle (AgNP) preparations differing in surface coating were determined in Chinese hamster ovary (CHO) subclone K1 cells. Three silver nanoparticle preparations ( x 90,0 polyvinylpyrrolidone (PVP-Ag) were used for the experiments. The cytotoxic effect of AgNPs was assessed with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide) test using different concentrations of nanoparticles, while the mutagenicity was evaluated using the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation assay. The cytotoxicity of all three AgNPs was lower in a cell culture medium containing 10% fetal calf serum (FCS) than in medium without FCS. The HPRT test without metabolic activation system S9 revealed that compared to the other AgNP formulations, citrate-coated Ag showed a lower genotoxic effect. However, addition of S9 increased the mutation frequency of all AgNPs and especially influenced the genotoxicity of Citrate-Ag. The results showed that exogenous metabolic activation of nanosilver is crucial even if interactions of the metabolic activation system, nanosilver, and cells are not really understood up to now.

  13. Boesenbergia pandurata attenuates diet-induced obesity by activating AMP-activated protein kinase and regulating lipid metabolism.

    Science.gov (United States)

    Kim, Dae-Young; Kim, Myung-Suk; Sa, Bo-Kyung; Kim, Mi-Bo; Hwang, Jae-Kwan

    2012-01-01

    Obesity, a chronic metabolic disorder, is characterized by enlarged fat mass and dysregulation of lipid metabolism. The medicinal plant, Boesenbergia pandurata (Roxb.) Schltr., has been reported to possess anti-oxidative and anti-inflammatory properties; however, its anti-obesity activity is unexplored. The present study was conducted to determine whether B. pandurata extract (BPE), prepared from its rhizome parts, attenuated high-fat diet (HFD)-induced obesity in C57BL/6J mice. The molecular mechanism was investigated in 3T3-L1 adipocytes and HepG2 human hepatoma cells. BPE treatment decreased triglyceride accumulation in both 3T3-L1 adipocytes and HepG2 hepatocytes by activating AMP-activated protein kinase (AMPK) signaling and regulating the expression of lipid metabolism-related proteins. In the animal model, oral administration of BPE (200 mg/kg/day for 8 weeks) significantly reduced HFD-induced body weight gain without altering the amount of food intake. In addition, elevated serum levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides were suppressed by BPE administration. Fat pad masses were reduced in BPE-treated mice, as evidenced by reduced adipocyte size. Furthermore, BPE protected against the development of nonalcoholic fatty liver by decreasing hepatic triglyceride accumulation. BPE also activated AMPK signaling and altered the expression of lipid metabolism-related proteins in white adipose tissue and liver. Taken together, these findings indicate that BPE attenuates HFD-induced obesity by activating AMPK and regulating lipid metabolism, suggesting a potent anti-obesity agent.

  14. Obesity Activates a Program of Lysosomal-Dependent Lipid Metabolism in Adipose Tissue Macrophages Independently of Classic Activation

    OpenAIRE

    Xu, Xiaoyuan; Grijalva, Ambar; Skowronski, Alicja; van Eijk, Marco; Serlie, Mireille J.; Ferrante Jr., Anthony W.

    2013-01-01

    Obesity activates a complex systemic immune response that includes the recruitment of macrophages and other immune cells to key metabolic tissues. Current models postulate that obesity and excess lipids classically activate macrophages, polarizing them toward an M1 (inflammatory) state. Little is known about noninflammatory functions of adipose tissue macrophages (ATMs). Here, we show that the expansion of adipose tissue (AT) across models of obesity induces a program of lysosome biogenesis i...

  15. Physical activity is associated with retained muscle metabolism in human myotubes challenged with palmitate

    DEFF Research Database (Denmark)

    Green, C J; Bunprajun, T; Pedersen, B K

    2013-01-01

      The aim of this study was to investigate whether physical activity is associated with preserved muscle metabolism in human myotubes challenged with saturated fatty acids. Human muscle satellite cells were isolated from sedentary or active individuals and differentiated into myocytes in culture....... Metabolic differences were then investigated in the basal state or after chronic palmitate treatment. At basal, myocytes from sedentary individuals exhibited higher CD36 and HSP70 protein expression as well as elevated phosphorylation of c-Jun NH2-terminal kinase (JNK) and insulin receptor substrate 1 (IRS1......) serine(307) compared to myocytes from active individuals. Despite equal lipid accumulation following palmitate treatment, myocytes from sedentary individuals exhibited delayed acetyl coenzyme A carboxylase phosphorylation compared to the active group. Myocytes from sedentary individuals had significantly...

  16. Determination of Alkaline Phosphatase Activity in Patients with Different Zinc Metabolic Disorders

    OpenAIRE

    KECHRID, Zine; KENOUZ, Rabah

    2003-01-01

    Our purpose was to investigate the effect of different zinc metabolic disorders on alkaline phosphatase activity. Serum zinc, glucose and alkaline phosphatase activity were studied in 32 patients with liver cirrhosis, 30 with chronic renal failure and 42 with insulin-dependent diabetes mellitus (IDDM) compared to 42 healthy volunteers. Serum glucose concentration was significantly higher (P < 0.001) in IDDM and liver cirrhosis patients (P < 0.05) compared to the controls. Serum ...

  17. Multilevel analysis of habitual physical activity and metabolic syndrome in Northern Taiwan.

    Science.gov (United States)

    Wang, Shi-Heng; Hsiao, Po-Chang; Hsiao, Chuhsing K; Liu, Pi-Hua; Chien, Kuo-Liong; Lin, Shue-Rong; Lee, Wen-Chung; Chen, Wei J

    2011-01-01

    This study examines the relationship between the availability of public facilities for habitual physical activity in the community and metabolic syndrome in northern Taiwan, one of most densely populated countries in the world. Subjects consisted of 14,658 participants (43.3% men and 56.7% women) ≥40 years old (mean=59.5) from 10 districts of Taoyuan County in a health check-up program in 2004-2005. Public facilities for habitual physical activity included school campuses and parks, and the density of such facilities was categorized into four levels. Multilevel logistic regression models were created to examine the effect on metabolic syndrome at both the individual and the contextual level using MLwiN software. The addition of the contextual variable to the model that included individual characteristics led to a further reduction of 7.2% in the variance. Using the facility density level I as the reference, the odds ratios (95% confidence interval) of metabolic syndrome for levels II, III, and IV were 0.87 (0.71-1.07), 0.87 (0.68-1.12), and 0.78 (0.61-0.99), respectively, with the trend test reaching significance. Greater availability of free facilities for habitual physical activity in a district was associated with a lower risk of metabolic syndrome among its residents. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Spatial localization of the first and last enzymes effectively connects active metabolic pathways in bacteria.

    Science.gov (United States)

    Meyer, Pablo; Cecchi, Guillermo; Stolovitzky, Gustavo

    2014-12-14

    Although much is understood about the enzymatic cascades that underlie cellular biosynthesis, comparatively little is known about the rules that determine their cellular organization. We performed a detailed analysis of the localization of E.coli GFP-tagged enzymes for cells growing exponentially. We found that out of 857 globular enzymes, at least 219 have a discrete punctuate localization in the cytoplasm and catalyze the first or the last reaction in 60% of biosynthetic pathways. A graph-theoretic analysis of E.coli's metabolic network shows that localized enzymes, in contrast to non-localized ones, form a tree-like hierarchical structure, have a higher within-group connectivity, and are traversed by a higher number of feed-forward and feedback loops than their non-localized counterparts. A Gene Ontology analysis of these enzymes reveals an enrichment of terms related to essential metabolic functions in growing cells. Given that these findings suggest a distinct metabolic role for localization, we studied the dynamics of cellular localization of the cell wall synthesizing enzymes in B. subtilis and found that enzymes localize during exponential growth but not during stationary growth. We conclude that active biochemical pathways inside the cytoplasm are organized spatially following a rule where their first or their last enzymes localize to effectively connect the different active pathways and thus could reflect the activity state of the cell's metabolic network.

  19. In-Situ Observations of a Subglacial Outflow Plume in a Greenland Fjord

    Science.gov (United States)

    Mankoff, K. D.; Straneo, F.; Singh, H.; Das, S. B.

    2014-12-01

    We present oceanographic observations collected in and immediately outside of a buoyant, fresh, sediment-laden subglacial outflow plume rising up the marine-terminating front of Sarqardleq Glacier, Greenland (68.9 N, 50.4 W). Subglacial outflow plumes, associated with the discharge at depth of upstream glacial surface melt, entrain the relatively warm fjord waters and are correlated with enhanced submarine melt and increased calving. Few in-situ observations exist due to the challenges of making measurements at the calving front of glaciers. Our data were collected using a small boat, a helicopter, and a JetYak (a remote-controlled jet-ski-powered kayak). Temperature and salinity profiles in, around, and far from the plume are used to described its oceanographic properties, spatial extent, and temporal variability. This plume rises vertically up the ice front expanding laterally and away from the ice, over-shoots its stable isopycnal and reaches the surface. Its surface expression is identified by colder, saltier, sediment-laden water flowing at ~5 m/s away from the ice face. Within ~300 m from the ice it submerges as it seeks buoyant stability.

  20. Neurons have an active glycogen metabolism that contributes to tolerance to hypoxia.

    Science.gov (United States)

    Saez, Isabel; Duran, Jordi; Sinadinos, Christopher; Beltran, Antoni; Yanes, Oscar; Tevy, María F; Martínez-Pons, Carlos; Milán, Marco; Guinovart, Joan J

    2014-06-01

    Glycogen is present in the brain, where it has been found mainly in glial cells but not in neurons. Therefore, all physiologic roles of brain glycogen have been attributed exclusively to astrocytic glycogen. Working with primary cultured neurons, as well as with genetically modified mice and flies, here we report that-against general belief-neurons contain a low but measurable amount of glycogen. Moreover, we also show that these cells express the brain isoform of glycogen phosphorylase, allowing glycogen to be fully metabolized. Most importantly, we show an active neuronal glycogen metabolism that protects cultured neurons from hypoxia-induced death and flies from hypoxia-induced stupor. Our findings change the current view of the role of glycogen in the brain and reveal that endogenous neuronal glycogen metabolism participates in the neuronal tolerance to hypoxic stress.

  1. Evaluation of the relationship between self-reported physical activity and metabolic syndrome and its components in apparently healthy women.

    Science.gov (United States)

    Suárez-Ortegón, Milton Fabián; Arbeláez, Alejandra; Mosquera, Mildrey; Ramírez-Vélez, Robinson; Aguilar-De Plata, Cecilia

    2014-01-01

    The metabolic syndrome, a set of metabolic anomalies that include insulin resistance, central obesity, dyslipidemia, hypertension and inflammation, is an important tool to explore factors associated to cardiometabolic disease. The aim of this study was to evaluate the relationship of the levels of self-reported physical activity and the International Physical Activity Questionnaire items and the metabolic syndrome and the variables related to cardiovascular risk in 89 women. The short version of International Physical Activity Questionnaire was applied to classify participating subjects into three categories: insufficient, sufficient and very active physical activity. The metabolic syndrome was assessed according to the International Diabetes Federation criteria. Biochemical and anthropometrical parameters were measured . Twenty-two participants (23%) presented metabolic syndrome and 66 women (74.2%) were classified in the insufficient physical activity category. No association was found between insufficient physical activity and metabolic syndrome . Inverse correlations were found among the days and minutes per week of physical activity of moderate-intensity, waist circumference ( r =-0.327, and r =-0.313, pphysical activity was found in the study participants, but this was not associated with metabolic syndrome . Moderate but not vigorous physical activity items from the International Physical Activity Questionnaire correlated inversely with anthropometrical markers related to cardiovascular risk.

  2. [Effects of Dietary and Physical Activity Interventions on Metabolic Syndrome: A Meta-analysis].

    Science.gov (United States)

    Lee, Guna; Choi, Hye Young; Yang, Sook Ja

    2015-08-01

    This study identified effects of dietary and physical activity interventions including dietary interventions or physical activity interventions alone or combined dietary-physical activity interventions to improve symptoms in metabolic syndrome including abdominal obesity, high triglycerides, low high density lipoprotein cholesterol, elevated blood pressure, and elevated fasting glucose through meta-analysis. Articles on metabolic syndrome X published from 1988 to 2013 were searched through electronic databases, Google Scholar, and reference reviews. Methodological quality was assessed by the checklist, SIGN (Scottish Intercollegiate Guidelines Network). In the meta-analysis, there were 9 articles reporting 13 interventions with 736 participants. Using random effect models, the dietary and/or physical activity interventions showed a lower mean difference in waist circumference (-1.30 cm, 95% CI:-2.44~-0.15, p=.027). The combined dietary-physical activity interventions showed a lower mean difference in waist circumference (-2.77 cm, 95% CI:-4.77~-0.76, p=.007) and systolic blood pressure (-5.44 mmHg, 95% CI:-10.76~-0.12, p=.044). Additionally, interventions of over 24 weeks yielded a lower mean difference in waist circumference (-2.78 cm, 95% CI:-4.69~-0.87, p=.004) and diastolic blood pressure (-1.93 mmHg, 95% CI:-3.63~-0.22, p=.026). The findings indicate that dietary and/or physical activity interventions for metabolic syndrome reduce central obesity with no adverse effects. This finding provides objective evidences for dietary and physical activity management on metabolic syndrome as an efficient intervention.

  3. Effects of a web-based intervention on physical activity and metabolism in older adults: randomized controlled trial

    NARCIS (Netherlands)

    Wijsman, C.A.; Westendorp, R.G.; Verhagen, E.A.L.M.; Catt, M.; Slagboom, P.E.; de Craen, A.J.; Broekhuizen, K.; van Mechelen, W.; van Heemst, D.; van der Ouderaa, F.; Mooijaart, S.P.

    2013-01-01

    Background: Lack of physical activity leads to detrimental changes in body composition and metabolism, functional decline, and increased risk of disease in old age. The potential of Web-assisted interventions for increasing physical activity and improving metabolism in older individuals holds great

  4. Relationship between metabolic syndrome and moderate-to-vigorous physical activity in youth.

    Science.gov (United States)

    Machado-Rodrigues, Aristides M; Leite, Neiva; Coelho e Silva, Manuel J; Valente-dos-Santos, João; Martins, Raul A; Mascarenhas, Luis P G; Boguszewski, Margaret C S; Padez, Cristina; Malina, Robert M

    2015-01-01

    Associations of metabolic syndrome (MetS) with lifestyle behaviors in youth is potentially important for identifying subgroups at risk and encourage interventions. This study evaluates the associations among the clustering of metabolic risk factors and moderate-to-vigorous physical activity (MVPA) in youth. The sample comprised 522 girls and 402 boys (N = 924) aged 11 to 17 years. Height, weight, waist circumference (WC), fasting glucose, high-density lipoprotein cholesterol, triglycerides, and blood pressures were measured. Cardiorespiratory fitness (CRF) was assessed using the 20-m shuttle run test. MVPA was estimated with a 3-day diary. Outcome variables were statistically normalized and expressed as z scores. A clustered metabolic risk score was computed as the mean of z scores. Multiple linear regression was used to test associations between metabolic risk and MVPA by sex, adjusted for age, WC, and CRF. After adjustment for potential confounders, MVPA was inversely associated with the clustering of metabolic risk factors in girls, but not in boys; in addition, after adjusting for WC, the statistical model of that relationship was substantially improved in girls. MVPA was independently associated with increased risk of MetS in girls. Additional efforts are needed to encourage research with different analytical approach and standardization of criteria for MetS in youth.

  5. Associations Between Physical Activity and Metabolic Syndrome: Comparison Between Self-Report and Accelerometry.

    Science.gov (United States)

    Tucker, Jared M; Welk, Gregory J; Beyler, Nicholas K; Kim, Youngwon

    2016-01-01

    To assess the relationship between self-reported and objectively measured physical activity (PA) and metabolic syndrome and its risk factors in U.S. adults. A cross-sectional design was used for this study. The study was set among a nationally representative sample of U.S. adults. Adults, ages 20 years and older, from the National Health and Nutrition Examination Survey (NHANES) 2003-2006 (n = 5580) participated in the study. PA measures included minutes per week of moderate plus vigorous PA estimated by self-report (MVPAsr), total 7-day accelerometry (MVPAa), and accelerometer-based MVPA performed in 10-minute bouts (MVPAb). Risk factors for metabolic syndrome included blood pressure, high-density lipoprotein cholesterol, triglycerides, glucose, and waist circumference. Odds ratios (ORs) for having metabolic syndrome were calculated for men and women who met the Physical Activity Guidelines for Americans compared to those who did not. Women who did not meet the PA guidelines had significantly greater odds of having metabolic syndrome according to MVPAsr (OR = 2.20; 95% confidence interval [CI] = 1.65-2.94), MVPAa (OR = 4.40; 95% CI = 2.65-7.31), and MVPAb (OR = 2.91; 95% CI = 1.42-5.96). Men had significantly higher odds of having metabolic syndrome according to MVPAa (OR = 2.57; 95% CI = 1.91-3.45) and MVPAb (OR = 2.83; 95% CI = 1.55-5.17), but not MVPAsr. These ORs remained significant after adjusting for all potential confounders except body mass index, after which only MVPAsr in women and MVPAb in men remained significant. Individuals who do not meet the PA guidelines exhibited greater odds of having metabolic syndrome. This relationship tended to be stronger for objective PA measures than for self-report.

  6. Priming of metabolic dysfunctions by prenatal immune activation in mice: relevance to schizophrenia.

    Science.gov (United States)

    Pacheco-López, Gustavo; Giovanoli, Sandra; Langhans, Wolfgang; Meyer, Urs

    2013-03-01

    Schizophrenia is associated with increased risk for multiple metabolic abnormalities, including altered glucose homeostasis, type-2 diabetes, obesity, and cardiovascular disease. Some of the metabolic alterations can already exist in psychosis-prone subjects prior to the onset of chronic schizophrenic disease and pharmacotherapy, indicating that they may have a developmental origin. In the present study, we tested the hypothesis that metabolic alterations pertinent to schizophrenic disease can be primed by an environmental risk factor associated with the disorder, namely prenatal exposure to immune challenge. We used a well-established mouse model of prenatal immune challenge induced by maternal gestational treatment with poly(I:C) (="polyriboinosinic-polyribocytidilic acid"), an analog of double-stranded RNA that stimulates a cytokine-associated viral-like acute phase response. Metabolic effects were studied using high-resolution computed tomography and fully automated indirect calorimetry system, along with an oral glucose tolerance test and plasma cytokine and corticosterone measurements. We found that prenatal immune activation caused altered glycemic regulation and abnormal ingestive behavior in periadolescence and led to an adult onset of excess visceral and subcutaneous fat deposition. These effects were accompanied by age-dependent changes in peripheral secretion of proinflammatory (interleukin [IL]-6 and tumor necrosis factor [TNF]-α) and T cell-related (IL-2 and interferon [IFN]-γ) cytokines and by increased release of the stress hormone corticosterone in periadolescence. Our findings show that schizophrenia-relevant metabolic and physiological abnormalities can be primed by prenatal viral-like immune activation, but at the same time, our study emphasizes that this environmental insult is unlikely to precipitate the full spectrum of metabolic and immunological changes pertinent to chronic schizophrenic disease.

  7. Killed but metabolically active Salmonella typhimurium: application of a new technology to an old vector.

    Science.gov (United States)

    Lankowski, Alexander J; Hohmann, Elizabeth L

    2007-04-15

    Previous studies have shown that attenuated salmonellae utilized as vaccine vectors engender strong immune responses; however, balancing immunogenicity with reactogenicity remains problematic. Recent work in other bacteria has shown that photochemical treatment of DNA excision repair mutants ( Delta uvrAB) renders organisms "killed but metabolically active" (KBMA). Here, we extend this concept to Salmonella typhimurium. A strain of attenuated S. typhimurium previously evaluated in human volunteers was further deleted for uvrAB genes and designated CKS362. Photochemical treatment of CKS362 resulted in significant inactivation. These KBMA organisms were metabolically active as shown by radioactive methionine incorporation and lactate dehydrogenase activity. In mice inoculated intraperitoneally, KBMA CKS362 was markedly less reactogenic and stimulated a humoral immune equivalent to its live counterpart. Because the parental strain has previously been found to elicit strong immune responses to Salmonella antigens, we propose CKS362 as a prototype strain to test the immunogenicity of KBMA organisms in humans.

  8. Metabolic adaptation to intermittent fasting is independent of peroxisome proliferator-activated receptor alpha.

    Science.gov (United States)

    Li, Guolin; Brocker, Chad N; Yan, Tingting; Xie, Cen; Krausz, Kristopher W; Xiang, Rong; Gonzalez, Frank J

    2018-01-01

    Peroxisome proliferator-activated receptor alpha (PPARA) is a major regulator of fatty acid oxidation and severe hepatic steatosis occurs during acute fasting in Ppara-null mice. Thus, PPARA is considered an important mediator of the fasting response; however, its role in other fasting regiments such as every-other-day fasting (EODF) has not been investigated. Mice were pre-conditioned using either a diet containing the potent PPARA agonist Wy-14643 or an EODF regimen prior to acute fasting. Ppara-null mice were used to assess the contribution of PPARA activation during the metabolic response to EODF. Livers were collected for histological, biochemical, qRT-PCR, and Western blot analysis. Acute fasting activated PPARA and led to steatosis, whereas EODF protected against fasting-induced hepatic steatosis without affecting PPARA signaling. In contrast, pretreatment with Wy-14,643 did activate PPARA signaling but did not ameliorate acute fasting-induced steatosis and unexpectedly promoted liver injury. Ppara ablation exacerbated acute fasting-induced hypoglycemia, hepatic steatosis, and liver injury in mice, whereas these detrimental effects were absent in response to EODF, which promoted PPARA-independent fatty acid metabolism and normalized serum lipids. These findings indicate that PPARA activation prior to acute fasting cannot ameliorate fasting-induced hepatic steatosis, whereas EODF induced metabolic adaptations to protect against fasting-induced steatosis without altering PPARA signaling. Therefore, PPARA activation does not mediate the metabolic adaptation to fasting, at least in preventing acute fasting-induced steatosis. Published by Elsevier GmbH.

  9. Geochemical Processes Leading to the Precipitation of Subglacial Carbonate Crusts at Bossons Glacier, Mont Blanc Massif (French Alps

    Directory of Open Access Journals (Sweden)

    Christophe Thomazo

    2017-09-01

    Full Text Available Cold climate carbonates can be used as paleoclimatic proxies. The mineralogy and isotopic composition of subglacially precipitated carbonate crusts (SPCCs provide insights into the subglacial conditions and processes occurring at the meltwater-basement rock interface of glaciers. This study documents such crusts discovered on the lee side of a gneissic roche moutonnée at the terminus of the Bossons glacier in the Mont Blanc Massif area (France. The geological context and mineralogical investigations suggest that the Ca used for the precipitation of large crystals of radial fibrous sparite observed in these crusts originated from subglacial chemical weathering of Ca-bearing minerals of the local bedrock (plagioclase and amphibole. Measurements of the carbon and oxygen isotope compositions in the crusts indicate precipitation at, or near to, equilibrium with the basal meltwater under open system conditions during refreezing processes. The homogeneous and low carbonate δ13C values (ca. −11.3‰ imply a large contribution of soil organic carbon to the Bossons subglacial meltwater carbon reservoir at the time of deposition. In addition, organic remains trapped within the SPCCs give an age of deposition around 6,500 years cal BP suggesting that the Mid-Holocene climatic and pedological optima are archived in the Bossons glacier carbonate crusts.

  10. Subglacial bed conditions during Late Pleistocene glaciations and their impact on ice dynamics in the southern North Sea

    NARCIS (Netherlands)

    Passchier, S.; Laban, C.; Mesdag, C.S.; Rijsdijk, K.F.

    2010-01-01

    Changes in subglacial bed conditions through multiple glaciations and their effect on ice dynamics are addressed through an analysis of glacigenic sequences in the Upper Pleistocene stratigraphy of the southern North Sea basin. During Elsterian (MIS 12) ice growth, till deposition was subdued when

  11. Metabolic activity and behavior of the invasive amphipod Dikerogammarus villosus and two common Central European gammarid species (Gammarus fossarum, Gammarus roeselii): Low metabolic rates may favor the invader.

    Science.gov (United States)

    Becker, Jochen; Ortmann, Christian; Wetzel, Markus A; Koop, Jochen H E

    2016-01-01

    The Ponto-Caspian amphipod Dikerogammarus villosus is one of the most successful invaders in Central European rivers. Contrary to studies on its ecology, ecophysiological studies comparing the species' physiological traits are scarce. In this context, in particular the metabolic activity of the invasive species has rarely been considered and, moreover, the few existing studies on this species report strongly deviating results. The purpose of this study was to assess the metabolic activity and behavior of D. villosus and other common European amphipod species (Gammarus fossarum, Gammarus roeselii) in relation to temperatures covering the thermal regime of the invaded habitats. Based on direct calorimetric measurements of metabolic heat dissipation at three temperature levels (5°C, 15°C and 25°C), we found the routine metabolic rate of D. villosus to be significantly lower than that of the other studied gammarid species at the medium temperature level. The estimated resting metabolic rate indicated a similar trend. At 5°C and 25°C, both routine and resting metabolic rate did not differ between species. Compared to G. fossarum and G. roeselii, D. villosus exhibited lower locomotor activity at the low and medium temperatures (5°C and 15°C). In contrast, its locomotor activity increased at the high experimental temperature (25°C). G. fossarum and G. roeselii were apparently more active than D. villosus at all studied temperatures. We conclude that D. villosus has both physiological and behavioral adaptations that lead to a reduction in metabolic energy expenditure, which is assumed to be beneficial and might contribute to its invasive success. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Altered metabolism of gut microbiota contributes to chronic immune activation in HIV-infected individuals.

    Science.gov (United States)

    Vázquez-Castellanos, J F; Serrano-Villar, S; Latorre, A; Artacho, A; Ferrús, M L; Madrid, N; Vallejo, A; Sainz, T; Martínez-Botas, J; Ferrando-Martínez, S; Vera, M; Dronda, F; Leal, M; Del Romero, J; Moreno, S; Estrada, V; Gosalbes, M J; Moya, A

    2015-07-01

    Altered interplay between gut mucosa and microbiota during treated HIV infection may possibly contribute to increased bacterial translocation and chronic immune activation, both of which are predictors of morbidity and mortality. Although a dysbiotic gut microbiota has recently been reported in HIV+ individuals, the metagenome gene pool associated with HIV infection remains unknown. The aim of this study is to characterize the functional gene content of gut microbiota in HIV+ patients and to define the metabolic pathways of this bacterial community, which is potentially associated with immune dysfunction. We determined systemic markers of innate and adaptive immunity in a cohort of HIV-infected individuals on successful antiretroviral therapy without comorbidities and in healthy non-HIV-infected subjects. Metagenome sequencing revealed an altered functional profile, with enrichment of the genes involved in various pathogenic processes, lipopolysaccharide biosynthesis, bacterial translocation, and other inflammatory pathways. In contrast, we observed depletion of genes involved in amino acid metabolism and energy processes. Bayesian networks showed significant interactions between the bacterial community, their altered metabolic pathways, and systemic markers of immune dysfunction. This study reveals altered metabolic activity of microbiota and provides novel insight into the potential host-microbiota interactions driving the sustained inflammatory state in successfully treated HIV-infected patients.

  13. N-3 fatty acids, neuronal activity and energy metabolism in the brain

    Directory of Open Access Journals (Sweden)

    Harbeby Emilie

    2012-07-01

    Full Text Available The content of docosahexaenoic acid (DHA in brain membranes is of crucial importance for the optimum development of brain functions. A lack of DHA accretion in the brain is accompanied by deficits in learning behavior linked to impairments in neurotransmission processes, which might result from alteration of brain fuel supply and hence energy metabolism. Experimental data we published support the hypothesis that n-3 fatty acids may modulate brain glucose utilization and metabolism. Indeed rats made deficient in DHA by severe depletion of total n-3 fatty acid intake have 1 a lower brain glucose utilization, 2 a decrease of the glucose transporter protein content GLUT1 both in endothelial cells and in astrocytes, 3 a repression of GLUT1 gene expression in basal state as well as upon neuronal activation. This could be due to the specific action of DHA on the regulation of GLUT1 expression since rat brain endothelial cells cultured with physiological doses of DHA had an increased GLUT1 protein content and glucose transport when compared to non-supplemented cells. These experimental data highlight the impact of n-3 fatty acids on the use of brain glucose, thereby constituting a key factor in the control of synaptic activity. This emerging role suggests that dietary intake of n-3 fatty acids can help to reduce the cognitive deficits in the elderly and possibly symptomatic cerebral metabolic alterations in Alzheimer disease by promoting brain glucose metabolism.

  14. Regulation of the yeast metabolic cycle by transcription factors with periodic activities

    Directory of Open Access Journals (Sweden)

    Pellegrini Matteo

    2011-10-01

    Full Text Available Abstract Background When growing budding yeast under continuous, nutrient-limited conditions, over half of yeast genes exhibit periodic expression patterns. Periodicity can also be observed in respiration, in the timing of cell division, as well as in various metabolite levels. Knowing the transcription factors involved in the yeast metabolic cycle is helpful for determining the cascade of regulatory events that cause these patterns. Results Transcription factor activities were estimated by linear regression using time series and genome-wide transcription factor binding data. Time-translation matrices were estimated using least squares and were used to model the interactions between the most significant transcription factors. The top transcription factors have functions involving respiration, cell cycle events, amino acid metabolism and glycolysis. Key regulators of transitions between phases of the yeast metabolic cycle appear to be Hap1, Hap4, Gcn4, Msn4, Swi6 and Adr1. Conclusions Analysis of the phases at which transcription factor activities peak supports previous findings suggesting that the various cellular functions occur during specific phases of the yeast metabolic cycle.

  15. Inhibitory Effect of Apigenin on Losartan Metabolism and CYP2C9 Activity in vitro.

    Science.gov (United States)

    Wang, Zhe; Gong, Yun; Zeng, Da-Li; Chen, Lian-Guo; Lin, Gao-Tong; Huang, Cheng-Ke; Sun, Wei; Chen, Meng-Chun; Hu, Guo-Xin; Chen, Rui-Jie

    2016-01-01

    CYP2C9 is one of the most important phase I drug-metabolizing enzymes in liver. The objective of this work was to investigate the effects of apigenin on the metabolism of losartan and human CYP2C9 and rat CYP2C11 activity in vitro. Different concentrations of apigenin were added to a 100 mmol/l Tris-HCl reaction mixture containing 2 pmol/ml recombinant human CYP2C9.1, 0.25 mg/ml human liver microsomes or 0.5 mg/ml rat liver microsomes to determine the half maximal inhibition or a half-maximal inhibitory concentration (IC50) on the metabolism of losartan. In addition, diclofenac used as CYP2C9 substrate was performed to determine the effects of apigenin on CYP2C9. The results showed that apigenin has the inhibitory effect on the metabolism of losartan in vitro, the IC50 was 7.61, 4.10 and 11.07 μmol/l on recombinant CYP2C9 microsomes, human liver microsomes and rat liver microsomes, respectively. Meanwhile, apigenin's mode of action on human CYP2C9 activity was competitive for the substrate diclofenac. In contrast to its potent inhibition of CYP2C9 in humans (9.51 μmol/l), apigenin had lesser effects on CYP2C11 in rat (IC50 = 15.51 μmol/l). The observations imply that apigenin has the inhibitory effect on the metabolism of losartan and CYP2C9 activity in vitro. More attention should be paid as to when losartan should be administrated combined with apigenin. © 2016 S. Karger AG, Basel.

  16. Seasonal variation in metabolic rate, flight activity and body size of Anopheles gambiae in the Sahel.

    Science.gov (United States)

    Huestis, Diana L; Yaro, Alpha S; Traoré, Adama I; Dieter, Kathryne L; Nwagbara, Juliette I; Bowie, Aleah C; Adamou, Abdoulaye; Kassogué, Yaya; Diallo, Moussa; Timbiné, Seydou; Dao, Adama; Lehmann, Tovi

    2012-06-15

    Malaria in Africa is vectored primarily by the Anopheles gambiae complex. Although the mechanisms of population persistence during the dry season are not yet known, targeting dry season mosquitoes could provide opportunities for vector control. In the Sahel, it appears likely that M-form A. gambiae survive by aestivation (entering a dormant state). To assess the role of eco-physiological changes associated with dry season survival, we measured body size, flight activity and metabolic rate of wild-caught mosquitoes throughout 1 year in a Sahelian locality, far from permanent water sources, and at a riparian location adjacent to the Niger River. We found significant seasonal variation in body size at both the Sahelian and riparian sites, although the magnitude of the variation was greater in the Sahel. For flight activity, significant seasonality was only observed in the Sahel, with increased flight activity in the wet season when compared with that just prior to and throughout the dry season. Whole-organism metabolic rate was affected by numerous biotic and abiotic factors, and a significant seasonal component was found at both locations. However, assay temperature accounted completely for seasonality at the riparian location, while significant seasonal variation remained after accounting for all measured variables in the Sahel. Interestingly, we did not find that mean metabolic rate was lowest during the dry season at either location, contrary to our expectation that mosquitoes would conserve energy and increase longevity by reducing metabolism during this time. These results indicate that mosquitoes may use mechanisms besides reduced metabolic rate to enable survival during the Sahelian dry season.

  17. Shift work and metabolic syndrome: respective impacts of job strain, physical activity, and dietary rhythms.

    Science.gov (United States)

    Esquirol, Yolande; Bongard, Vanina; Mabile, Laurence; Jonnier, Bernard; Soulat, Jean-Marc; Perret, Bertrand

    2009-04-01

    The impact of shift work on cardiovascular disease (CVD) risk factors and metabolic syndrome are not yet completely understood. The objectives of this study were to evaluate the impact of shift work on metabolic syndrome according to two different definitions in a population of strictly rotating shift workers (3x8 h) compared to paired counterparts working only day hours, and to study whether shift work itself is a determinant of metabolic syndrome after taking into account a large panel of confusing factors. We conducted a cross-sectional study comparing 98 strictly rotating shift workers to 100 regular day-workers (all subjects had a long experience of their working rhythms) within the same petrochemical plant. Clinical, behavioral, occupational, and biological data were collected, and a detailed nutritional investigation was done. Shift and day workers were comparable in terms of major CVD factors, and both had a 10 yr Framingham risk scoring of 11%. Shift workers reported an increased job strain and higher total and at-work physical activity. Alterations in metabolic parameters were evident with a rise in triglycerides, free fatty acids, and gamma glutamyl transpeptidase and lower HDL-cholesterol. Multiple logistic regression analysis demonstrated that shift work was associated with occurrence of metabolic syndrome, as defined by the National Cholesterol Education Program-ATPIII criteria, OR: 2.38 (1.13-4.98), but not using the more recent score from the International Diabetes Federation, which gives a major emphasis on abdominal obesity. Total energy intake and contributions of the major nutrients did not differ between the two groups, with the notable exception of saturated lipids (+10% in shift workers). Meal distribution was clearly different: energy intake was more fractionated within the day, with a lesser contribution of breakfast and lunch but with increased intakes during intermediate light meals, particularly in the afternoon and night. Multivariate

  18. Analysis of subglacial hydrodynamics and ice dynamics through combined terrestrial laser scanning and ground penetrating radar survey

    Science.gov (United States)

    Gabbud, Chrystelle; Rüttimann, Sébastien; Micheletti, Natan; Irving, James; Lane, Stuart

    2015-04-01

    This study shows how high resolution surveys of subglacial channel morphology combined with high resolution terrestrial laser scanner survey of an Alpine glacier help to understand subglacial hydrological forcing of ice dynamics. The study area is the Haut Glacier d'Arolla in Switzerland, an Alpine valley glacier for which subglacial drainage system has been well studied. A new generation of terrestrial laser scanners was used to investigate glacier surface ablation and other elements of glacial hydrodynamics at exceptionally high spatial and temporal resolution. The LiDAR RIEGL VZ-6000 scanner, with a laser 3B specifically designed for measurements of snow and ice cover surfaces, was tested at seasonal and daily scales. The data revealed spatial variations in the patterns of surface melt, controlled by both aspect and differential debris cover at the seasonal scale, and controlled by ogive-related differences in ice surface debris content at the daily scale. More tentatively, intra-daily scale measurements pointed to possible hydraulic jacking of the glacier associated with short-term water pressure rises at the downstream part of the glacier. A ground-penetrating radar (GPR) field campaign was conducted a year later in the location where possible hydraulic jacking had been detected previously. The aims of this campaign were (i) to assess GPR usage for subglacial channel detection; (ii) identify more precisely the channel morphology; and (iii) investigate further the hydraulic jacking hypothesis. 100 MHz antennas were used to map a 240 x 34 m area near the glacier snout where the ice thickness did not exceed 50 m. The corresponding data, after processing, allowed reconstruction of the bed topography and the morphology of subglacial channels in 3D, showing two of the latter in this area. One channel was followed for approximately 20 m upglacier and corresponding morphology estimates were performed. These data allowed for 3D reconstructions of both the bed

  19. Tracking seasonal subglacial drainage evolution of alpine glaciers using radiogenic Nd and Sr isotope systematics: Lemon Creek Glacier, Alaska

    Science.gov (United States)

    Clinger, A. E.; Aciego, S.; Stevenson, E. I.; Arendt, C. A.

    2014-12-01

    The transport pathways of water beneath a glacier are subject to change as melt seasons progress due to variability in the balance between basal water pressure and water flux. Subglacial hydrology has been well studied, but the understanding of spatial distribution is less well constrained. Whereas radiogenic isotopic tracers have been traditionally used as proxies to track spatial variability and weathering rates in fluvial and riverine systems, these techniques have yet to be applied extensively to the subglacial environment and may help resolve ambiguity in subglacial hydrology. Research has shown the 143Nd/144Nd values can reflect variation in source provenance processes due to variations in the age of the continental crust. Correlating the 143Nd/144Nd with other radiogenic isotope systematics such as strontium (87Sr/86Sr) provides important constraints on the role of congruent and incongruent weathering processes. Our study presents the application of Nd and Sr systematics using isotopic ratios to the suspended load of subglacial meltwater collected over a single melt season at Lemon Creek Glacier, USA (LCG). The time-series data show an average ɛNd ~ -6.83, indicating a young bedrock (~60 MYA). Isotopic variation helps track the seasonal expansion of the subglacial meltwater channels and subsequent return to early season conditions due to the parabolic trend towards less radiogenic Nd in June and towards more radiogenic Nd beginning in mid-August. However, the high variability in July and early August may reflect a mixture of source as the channels diverge and derive sediment from differently aged lithologies. We find a poor correlation between 143Nd/144Nd and 87Sr/86Sr (R2= 0.38) along with a slight trend towards more radiogenic 87Sr/86Sr values with time ((R2= 0.49). This may indicate that, even as the residence time decreases over the melt season, the LCG subglacial system is relatively stable and that the bedrock is congruently weathered. Our study

  20. Observations and modelling of subglacial discharge and heat transport in Godthåbsfjord (Greenland, 64 °N)

    Science.gov (United States)

    Bendtsen, Jørgen; Mortensen, John; Rysgaard, Søren

    2017-04-01

    Subglacial discharge from tidewater outlet glaciers forms convective bouyant freshwater plumes ascending close the glacier face, and entrainment of ambient bottom water increases the salinity of the water until the plume reaches its level of neutral buoyancy at sub-surface levels or reaches the surface. Relatively warm bottom water masses characterize many fjords around Greenland and therefore entrainment would also increase the temperature in the plumes and, thereby, impact the heat transport in the fjords. However, relatively few oceanographic measurements have been made in or near plumes from subglacial discharge and, therefore, the potential for subglacial discharge for increasing heat transport towards the tidewater outlet glaciers are poorly understood. We present the first direct hydrographic measurements in a plume from subglacial discharge in Godthåbsfjord (located on the western coast of Greenland) where a XCTD was launched from a helicopter directly into the plume. Measurements of the surface salinity showed that the plume only contained 7% of freshwater at the surface, implying a large entrainment with a mixing ratio of 1:13 between outflowing meltwater and saline fjord water. These observations are analyzed together with seasonal observations of ocean heat transport towards the tidewater outlet glaciers in Godthåbsfjord and we show that subglacial discharge only had modest effects on the overall heat budget in front of the glacier. These results were supported from a high-resolution three-dimensional model of Godthåbsfjord. The model explicitly considered subglacial freshwater discharge from three tidewater outlet glaciers where entrainment of bottom water was taken into account. Model results showed that subglacial discharge only affected the fjord circulation relatively close ( 10 km) to the glaciers. Thus, the main effect on heat transport was due to the freshwater discharge itself whereas the subsurface discharge and associated entrainment only

  1. Metabolically active microbial communities of yellow and grey colonizations on the walls of Altamira Cave, Spain.

    Science.gov (United States)

    Portillo, M C; Gonzalez, J M; Saiz-Jimenez, C

    2008-03-01

    To determine the major components of total and metabolically active microbial communities of yellow and grey colonizations threatening the conservation of palaeolithic paintings in Altamira Cave (Spain). Micro-organisms present in yellow and grey colonizations were determined from DNA analysis with those showing metabolic activity determined from RNA analysis. Microbial community fingerprints were obtained by denaturing gradient gel electrophoresis (DGGE) and 16S rDNA libraries were constructed from PCR amplified products. Proteobacteria was the most frequent bacterial phylum. Other phyla detected from RNA-based microbial surveys were Acidobacteria, Actinobacteria, Firmicutes, Nitrospirae and Gemmatimonadetes. The detected metabolically active micro-organisms represented only a fraction of the total bacterial community present in the studied colonizations as compared from DGGE analysis. The major bacterial participants in the development of yellow and grey colonizations in Altamira Cave were determined using RNA-based molecular techniques. Micro-organisms showing undetectable activity represent a potential risk for the conservation of these paintings if environmental conditions experience variations. Caves with palaeolithic paintings are affected by microbial deterioration. Assessing the composition of the microbial communities colonizing these caves represents a first stage to understand and control these colonizations.

  2. Fluvoxamine alters the activity of energy metabolism enzymes in the brain

    Directory of Open Access Journals (Sweden)

    Gabriela K. Ferreira

    2014-09-01

    Full Text Available Objective: Several studies support the hypothesis that metabolism impairment is involved in the pathophysiology of depression and that some antidepressants act by modulating brain energy metabolism. Thus, we evaluated the activity of Krebs cycle enzymes, the mitochondrial respiratory chain, and creatine kinase in the brain of rats subjected to prolonged administration of fluvoxamine. Methods: Wistar rats received daily administration of fluvoxamine in saline (10, 30, and 60 mg/kg for 14 days. Twelve hours after the last administration, rats were killed by decapitation and the prefrontal cortex, cerebral cortex, hippocampus, striatum, and cerebellum were rapidly isolated. Results: The activities of citrate synthase, malate dehydrogenase, and complexes I, II-III, and IV were decreased after prolonged administration of fluvoxamine in rats. However, the activities of complex II, succinate dehydrogenase, and creatine kinase were increased. Conclusions: Alterations in activity of energy metabolism enzymes were observed in most brain areas analyzed. Thus, we suggest that the decrease in citrate synthase, malate dehydrogenase, and complexes I, II-III, and IV can be related to adverse effects of pharmacotherapy, but long-term molecular adaptations cannot be ruled out. In addition, we demonstrated that these changes varied according to brain structure or biochemical analysis and were not dose-dependent.

  3. Relationship between physical activity, physical fitness and multiple metabolic risk in youths from Muzambinho's study.

    Science.gov (United States)

    Barbosa, João Paulo Dos Anjos Souza; Basso, Luciano; Seabra, André; Prista, Antonio; Tani, Go; Maia, José António Ribeiro; Forjaz, Cláudia Lúcia De Moraes

    2016-08-01

    Negative associations between physical activity (PA), physical fitness and multiple metabolic risk factors (MMRF) in youths from populations with low PA are reported. The persistence of this association in moderately-to highly active populations is not, however, well established. The aim of the present study was to investigate this association in a Brazilian city with high frequency of active youths. We assessed 122 subjects (9.9 ± 1.3 years) from Muzambinho city. Body mass index, waist circumference, glycaemia, cholesterolaemia, systolic and diastolic blood pressures were measured. Maximal handgrip strength and one-mile walk/run test were used. Leisure time PA was assessed by interview. Poisson regression was used in the analysis. The model explained 11% of the total variance. Only relative muscular strength and one-mile walk/run were statistically significant (p run test had an increased in metabolic risk of 11%, and those with greater strength reduced the risk by about 82%. In conclusion, children and youths from an active population who need less time to cover the one-mile walk/run test or who had greater muscular strength showed a reduced metabolic risk. These results suggest that even in children and youths with high leisure time PA, a greater aerobic fitness and strength might help to further reduce their MMRF.

  4. Reactive oxygen species in the paraventricular nucleus of the hypothalamus alter sympathetic activity during metabolic syndrome.

    Directory of Open Access Journals (Sweden)

    JOSIANE CAMPOS CRUZ

    2015-12-01

    Full Text Available The paraventricular nucleus of the hypothalamus (PVN contains heterogeneous populations of neurons involved in autonomic and neuroendocrine regulation. The PVN plays an important role in the sympathoexcitatory response to increasing circulating levels of angiotensin II (Ang-II, which activates AT1 receptors in the circumventricular organs (OCVs, mainly in the subfornical organ (SFO. Circulating Ang-II induces a de novo synthesis of Ang-II in SFO neurons projecting to pre-autonomic PVN neurons. Activation of AT1 receptors induces intracellular increases in reactive oxygen species (ROS, leading to increases in sympathetic nerve activity (SNA. Chronic sympathetic nerve activation promotes a series of metabolic disorders that characterizes the metabolic syndrome (MetS: dyslipidemia, hyperinsulinemia, glucose intolerance, hyperleptinemia and elevated plasma hormone levels, such as noradrenaline, glucocorticoids, leptin, insulin and Ang-II. This review will discuss the contribution of our laboratory and others regarding the sympathoexcitation caused by peripheral Ang-II-induced reactive oxygen species along the subfornical organ and paraventricular nucleus of the hypothalamus. We hypothesize that this mechanism could be involved in metabolic disorders underlying MetS.

  5. Bixin activates PPARα and improves obesity-induced abnormalities of carbohydrate and lipid metabolism in mice.

    Science.gov (United States)

    Goto, Tsuyoshi; Takahashi, Nobuyuki; Kato, Sota; Kim, Young-Il; Kusudo, Tatsuya; Taimatsu, Aki; Egawa, Kahori; Kang, Min-Sook; Hiramatsu, Takuro; Sakamoto, Tomoya; Uemura, Taku; Hirai, Shizuka; Kobayashi, Misato; Horio, Fumihiko; Kawada, Teruo

    2012-12-05

    Peroxisome proliferator-activated receptor α (PPARα) is a ligand-activated transcription factor that regulates the expression of the genes involved in fatty acid oxidation. PPARα activators induce fatty acid oxidation in the liver, thereby improving lipid and carbohydrate metabolism in obese mice. In this study, the dietary cis-carotenoids bixin and norbixin, which are commonly used in the food coloring industry, were found to activate PPARα by luciferase reporter assays using GAL4/PPARα chimeric and full-length PPARα systems. Treatment with bixin and norbixin induced the mRNA expression of PPARα target genes involved in fatty acid oxidation in PPARα-expressing HepG2 hepatocytes. In obese KK-Ay mice, bixin treatment suppressed the development of hyperlipidemia and hepatic lipid accumulation. In the livers of bixin-treated mice, the mRNA levels of PPARα target genes related to fatty acid oxidation were up-regulated. Moreover, bixin treatment also improved obesity-induced dysfunctions of carbohydrate metabolism, such as hyperglycemia, hyperinsulinemia, and hypoadiponectinemia. Glucose tolerance test and insulin tolerance test revealed that glucose intolerance and insulin resistance in KK-Ay obese mice were attenuated by the treatment with bixin. These results indicate that bixin acts as a food-derived agonist of PPARα, and bixin treatment is useful for the management of obesity-induced metabolic dysfunctions in mice.

  6. Obesity Activates a Program of Lysosomal-Dependent Lipid Metabolism in Adipose Tissue Macrophages Independently of Classic Activation

    Science.gov (United States)

    Xu, Xiaoyuan; Grijalva, Ambar; Skowronski, Alicja; van Eijk, Marco; Serlie, Mireille J.; Ferrante, Anthony W.

    2014-01-01

    SUMMARY Obesity activates a complex systemic immune response that includes the recruitment of macrophages and other immune cells to key metabolic tissues. Current models postulate that obesity and excess lipids classically activate macrophages, polarizing them toward an M1 (inflammatory) state. Little is known about noninflammatory functions of adipose tissue macrophages (ATMs). Here, we show that the expansion of adipose tissue (AT) across models of obesity induces a program of lysosome biogenesis in ATMs and is associated with lipid catabolism but not a classic inflammatory phenotype. This program is induced by factors produced by AT and is tightly coupled to lipid accumulation by ATMs. Inhibition of ATM lysosome function impairs lipid metabolism and increases lipid content in ATMs and reduces whole AT lipolysis. These data argue that ATMs contribute quantitatively to the development of obesity-induced inflammation but also serve an important role in lipid trafficking independent of their inflammatory phenotype. PMID:24315368

  7. Obesity activates a program of lysosomal-dependent lipid metabolism in adipose tissue macrophages independently of classic activation.

    Science.gov (United States)

    Xu, Xiaoyuan; Grijalva, Ambar; Skowronski, Alicja; van Eijk, Marco; Serlie, Mireille J; Ferrante, Anthony W

    2013-12-03

    Obesity activates a complex systemic immune response that includes the recruitment of macrophages and other immune cells to key metabolic tissues. Current models postulate that obesity and excess lipids classically activate macrophages, polarizing them toward an M1 (inflammatory) state. Little is known about noninflammatory functions of adipose tissue macrophages (ATMs). Here, we show that the expansion of adipose tissue (AT) across models of obesity induces a program of lysosome biogenesis in ATMs and is associated with lipid catabolism but not a classic inflammatory phenotype. This program is induced by factors produced by AT and is tightly coupled to lipid accumulation by ATMs. Inhibition of ATM lysosome function impairs lipid metabolism and increases lipid content in ATMs and reduces whole AT lipolysis. These data argue that ATMs contribute quantitatively to the development of obesity-induced inflammation but also serve an important role in lipid trafficking independent of their inflammatory phenotype. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Constrained Total Energy Expenditure and Metabolic Adaptation to Physical Activity in Adult Humans.

    Science.gov (United States)

    Pontzer, Herman; Durazo-Arvizu, Ramon; Dugas, Lara R; Plange-Rhule, Jacob; Bovet, Pascal; Forrester, Terrence E; Lambert, Estelle V; Cooper, Richard S; Schoeller, Dale A; Luke, Amy

    2016-02-08

    Current obesity prevention strategies recommend increasing daily physical activity, assuming that increased activity will lead to corresponding increases in total energy expenditure and prevent or reverse energy imbalance and weight gain [1-3]. Such Additive total energy expenditure models are supported by exercise intervention and accelerometry studies reporting positive correlations between physical activity and total energy expenditure [4] but are challenged by ecological studies in humans and other species showing that more active populations do not have higher total energy expenditure [5-8]. Here we tested a Constrained total energy expenditure model, in which total energy expenditure increases with physical activity at low activity levels but plateaus at higher activity levels as the body adapts to maintain total energy expenditure within a narrow range. We compared total energy expenditure, measured using doubly labeled water, against physical activity, measured using accelerometry, for a large (n = 332) sample of adults living in five populations [9]. After adjusting for body size and composition, total energy expenditure was positively correlated with physical activity, but the relationship was markedly stronger over the lower range of physical activity. For subjects in the upper range of physical activity, total energy expenditure plateaued, supporting a Constrained total energy expenditure model. Body fat percentage and activity intensity appear to modulate the metabolic response to physical activity. Models of energy balance employed in public health [1-3] should be revised to better reflect the constrained nature of total energy expenditure and the complex effects of physical activity on metabolic physiology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Relation Between Metabolic Activity of the Broca Region and F-18 FDG Uptake in Vocal Cords

    Directory of Open Access Journals (Sweden)

    Mine Şencan Eren

    2012-08-01

    Full Text Available Objective: We aimed to investigate if increased F-18 Fluoro Deoxyglucose (F-18 FDG uptake observed in vocal cords (VC of the patients on Positron Emission Tomography/Computarize Tomography (PET/CT scans is connected to speaking of the patients or not. If so, we expected to detect an increased metabolic activity in Broca's area. In this study, we have retrospectively searched for a correlation between the activity in the Broca's area and vocal cords of patients who had undergone FDG PET for different indications. Material and Methods: FDG PET/CT scans of 30 patients with (VC [+] and 30 patients without (VC [-] bilateral F-18 FDG uptake on their vocal cords were retrospectively evaluated. Brain quantification was carried out on NeuroQ software with 20 iterations using patients' transaxial brain cross sections. On the 20th-23rd-26th-29th cross sections, area/whole brain ratios of the right (R and left (L for Broca’s area were calculated. VC (+ and VC (- patients' R and L Broca's areas were compared using Student's t-test. Results: There was no significant difference between the Broca's areas of VC (+ and VC (- patients. L Broca's areas of both VC (+ and VC (- patients were more active than R Broca's areas (p<0.05. There was a negative correlation between VC (+ patients' SUVmax values in the vocal cords and the activity in their R Broca's region. Conclusion: In our study, we did not find a significant difference between Broca's areas of VC (+ patients and VC (- patients, so the activity in their vocal cords does not seem to be related to increased metabolic activity in Broca's areas. We have concluded that the vocal cord activity is not related to speaking of the patients. The activity in the vocal cord might be due to inflammation or, as in the eye muscles, may be associated with high metabolism in laryngeal muscles. (MIRT 2012;21:42-46

  10. The Subglacial Access and Fast Ice Research Experiment (SAFIRE): 3. Englacial and subglacial conditions revealed by seismic reflection data on Store Glacier, West Greenland.

    Science.gov (United States)

    Hofstede, Coen; Eisen, Olaf; Young, Tun Jan; Doyle, Samuel; Hubbard, Bryn; Christoffersen, Poul; Hubbard, Alun

    2015-04-01

    Basal conditions have a profound influence on the dynamics of outlet glaciers. As part of the SAFIRE research programme, we carried out a seismic survey on Store Glacier, a tidewater glacier terminating in Uummanaq Fjord in West Greenland (see joint abstracts by Christoffersen et al. and Doyle et al. for details). At the survey site the ice moves 700m/a making the terrain crevassed and bumpy. Despite the rough terrain we collected two 1.5 km long survey lines parallel and perpendicular to the ice flow direction using a 300m snow streamer and explosives as a source. The seismic data reveal an ice thickness of about 620m and 20 to 30m of subglacial sediment on the upstream side of the area thinning in the downstream direction. From polarity reversals seen along the ice-bed contact we speculate that the sediments have varying degrees of water content. The ice itself has several englacial reflections parallel and close to the bed. At approximately 475m depth, a clear single englacial reflection is observed in the parallel survey line. Thermistor data installed at this location show a clear increase in ice temperature starting at this depth. We speculate that the observed englacial reflection is caused by a change in crystal orientation fabric allowing greater ice deformation below this depth causing increased strain heating.

  11. Physical activity, stress, and metabolic risk score in 8- to 18-year-old boys.

    Science.gov (United States)

    Holmes, Megan E; Eisenmann, Joey C; Ekkekakis, Panteleimon; Gentile, Douglas

    2008-03-01

    We examined whether physical activity modifies the relationship between stress and the metabolic risk score in 8- to 18-year-old males (n = 37). Physical activity (PA) and television (TV)/videogame (VG) use were assessed via accelerometer and questionnaire, respectively. Stress was determined from self-report measures. A metabolic risk score (MRS) was created by summing age-standardized residuals for waist circumference, mean arterial pressure, glycosylated hemoglobin, and high-density lipoprotein cholesterol. Correlations between PA and MRS were low (r sports-related self-esteem and anxiety with the MRS. The results provide suggestive evidence that PA might modify the relationship between stress and MRS in male adolescents.

  12. Direct neuronal glucose uptake Heralds activity-dependent increases in cerebral metabolism

    DEFF Research Database (Denmark)

    Lundgaard, Iben; Li, Baoman; Xie, Lulu

    2015-01-01

    -photon imaging of a near-infrared 2-deoxyglucose analogue (2DG-IR), that glucose is taken up preferentially by neurons in awake behaving mice. Anaesthesia suppressed neuronal 2DG-IR uptake and sensory stimulation was associated with a sharp increase in neuronal, but not astrocytic, 2DG-IR uptake. Moreover......Metabolically, the brain is a highly active organ that relies almost exclusively on glucose as its energy source. According to the astrocyte-to-neuron lactate shuttle hypothesis, glucose is taken up by astrocytes and converted to lactate, which is then oxidized by neurons. Here we show, using two......, hexokinase, which catalyses the first enzymatic steps in glycolysis, was highly enriched in neurons compared with astrocytes, in mouse as well as in human cortex. These observations suggest that brain activity and neuronal glucose metabolism are directly linked, and identify the neuron as the principal locus...

  13. Metabolism-Activated Multitargeting (MAMUT): An Innovative Multitargeting Approach to Drug Design and Development.

    Science.gov (United States)

    Mátyus, Péter; Chai, Christina L L

    2016-06-20

    Multitargeting is a valuable concept in drug design for the development of effective drugs for the treatment of multifactorial diseases. This concept has most frequently been realized by incorporating two or more pharmacophores into a single hybrid molecule. Many such hybrids, due to the increased molecular size, exhibit unfavorable physicochemical properties leading to adverse effects and/or an inappropriate ADME (absorption, distribution, metabolism, and excretion) profile. To avoid this limitation and achieve additional therapeutic benefits, here we describe a novel multitargeting strategy based on the synergistic effects of a parent drug and its active metabolite(s). The concept of metabolism-activated multitargeting (MAMUT) is illustrated using a number of examples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Analysis of cytogenetic effect in human lymphocytes induced by metabolically activated 2-nitropropane.

    Science.gov (United States)

    Bauchinger, M; Kulka, U; Schmid, E

    1987-03-01

    Chromosome analyses were carried out in human lymphocytes treated in vitro with 2-nitropropane (2-NP) in the presence and absence of the mammalian metabolic activation system, S9 mix. Without S9 mix, only the frequency of gaps was significantly increased at 80 mM 2-NP as compared to controls. With S9 mix, the incidences of gaps and chromatid-type aberrations were significantly increased at 60 mM and 80 mM. Sister-chromatid exchanges (SCE) have been induced at concentrations as low as 7.5 mM. The present findings demonstrate that in human lymphocytes, 2-NP requires metabolic activation to express clastogenicity and SCEs.

  15. Orbital fluid shear stress promotes osteoblast metabolism, proliferation and alkaline phosphates activity in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Aisha, M.D. [Institute of Medical Molecular Biotechnology and Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh 47000, Selangor (Malaysia); Nor-Ashikin, M.N.K. [Institute of Medical Molecular Biotechnology and Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh 47000, Selangor (Malaysia); DDH, Universiti Teknologi MARA, ShahAlam 40450, Selangor (Malaysia); Sharaniza, A.B.R. [DDH, Universiti Teknologi MARA, ShahAlam 40450, Selangor (Malaysia); Nawawi, H. [Center for Pathology Diagnostic and Research Laboratories, Clinical Training Center, Universiti Teknologi MARA, Sungai Buloh 47000, Selangor (Malaysia); I-PPerForM, Universiti Teknologi MARA, Selayang 47000 Selangor (Malaysia); Froemming, G.R.A., E-mail: gabriele@salam.uitm.edu.my [Institute of Medical Molecular Biotechnology and Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh 47000, Selangor (Malaysia); I-PPerForM, Universiti Teknologi MARA, Selayang 47000 Selangor (Malaysia)

    2015-09-10

    Prolonged disuse of the musculoskeletal system is associated with reduced mechanical loading and lack of anabolic stimulus. As a form of mechanical signal, the multidirectional orbital fluid shear stress transmits anabolic signal to bone forming cells in promoting cell differentiation, metabolism and proliferation. Signals are channeled through the cytoskeleton framework, directly modifying gene and protein expression. For that reason, we aimed to study the organization of Normal Human Osteoblast (NHOst) cytoskeleton with regards to orbital fluid shear (OFS) stress. Of special interest were the consequences of cytoskeletal reorganization on NHOst metabolism, proliferation, and osteogenic functional markers. Cells stimulated at 250 RPM in a shaking incubator resulted in the rearrangement of actin and tubulin fibers after 72 h. Orbital shear stress increased NHOst mitochondrial metabolism and proliferation, simultaneously preventing apoptosis. The ratio of RANKL/OPG was reduced, suggesting that orbital shear stress has the potential to inhibit osteoclastogenesis and osteoclast activity. Increase in ALP activity and OCN protein production suggests that stimulation retained osteoblast function. Shear stress possibly generated through actin seemed to hold an anabolic response as osteoblast metabolism and functional markers were enhanced. We hypothesize that by applying orbital shear stress with suitable magnitude and duration as a non-drug anabolic treatment can help improve bone regeneration in prolonged disuse cases. - Highlights: • OFS stress transmits anabolic signals to osteoblasts. • Actin and tubulin fibers are rearranged under OFS stress. • OFS stress increases mitochondrial metabolism and proliferation. • Reduced RANKL/OPG ratio in response to OFS inhibits osteoclastogenesis. • OFS stress prevents apoptosis and stimulates ALP and OCN.

  16. Bace1 activity impairs neuronal glucose metabolism: rescue by beta-hydroxybutyrate and lipoic acid

    Directory of Open Access Journals (Sweden)

    John A Findlay

    2015-10-01

    Full Text Available Glucose hypometabolism and impaired mitochondrial function in neurons have been suggested to play early and perhaps causative roles in Alzheimer’s disease (AD pathogenesis. Activity of the aspartic acid protease, beta-site amyloid precursor protein (APP cleaving enzyme 1 (BACE1, responsible for beta amyloid peptide generation, has recently been demonstrated to modify glucose metabolism. We therefore examined, using a human neuroblastoma (SH-SY5Y cell line, whether increased BACE1 activity is responsible for a reduction in cellular glucose metabolism. Overexpression of active BACE1, but not a protease-dead mutant BACE1, protein in SH-SY5Y cells reduced glucose oxidation and the basal oxygen consumption rate, which was associated with a compensatory increase in glycolysis. Increased BACE1 activity had no effect on the mitochondrial electron transfer process but was found to diminish substrate delivery to the mitochondria by inhibition of key mitochondrial decarboxylation reaction enzymes. This BACE1 activity-dependent deficit in glucose oxidation was alleviated by the presence of beta hydroxybutyrate or α-lipoic acid. Consequently our data indicate that raised cellular BACE1 activity drives reduced glucose oxidation in a human neuronal cell line through impairments in the activity of specific tricarboxylic acid cycle enzymes. Because this bioenergetic deficit is recoverable by neutraceutical compounds we suggest that such agents, perhaps in conjunction with BACE1 inhibitors, may be an effective therapeutic strategy in the early-stage management or treatment of AD.

  17. Development of a Metabolically Active, Non-Replicating Sporozoite Vaccine to Prevent Plasmodium falciparum Malaria

    Science.gov (United States)

    2009-10-01

    deployment in the twentieth century of attenuated vaccines against viruses (e.g., polio, mea- sles, mumps rubella , yellow fever, Japanese encephalitis...annu- ally in sub-Saharan Africa. Another important rarger population is pre-adolescent g irls, in order to prevent malaria in pregnancy , which is...comparable to that achieved by IV administra- malaria in pregnancy and neonatal and infant mortality due to tion of metabolically active, non

  18. Tubulin polymerization by paclitaxel (taxol) phosphate prodrugs after metabolic activation with alkaline phosphatase.

    Science.gov (United States)

    Mamber, S W; Mikkilineni, A B; Pack, E J; Rosser, M P; Wong, H; Ueda, Y; Forenza, S

    1995-08-01

    Paclitaxel (taxol) phosphate derivatives BMY46366, BMY-46489, BMS180661 and BMS180820 were used to determine the ability of alkaline phosphatase to convert these water-soluble potential prodrugs to tubulin-polymerizing metabolites (i.e., paclitaxel). Compounds were treated up to 180 min with an in vitro metabolic activation system composed of 10% bovine alkaline phosphatase in 0.2 M tris, pH 7.4, or in 0.2 M glycine, pH 8.8, plus 0.05 M MgCl2. Samples were tested (either by direct addition or after methylene chloride extraction/dimethyl-sulfoxide resuspension) in spectrophotometric tubulin polymerization assays utilizing bovine-derived microtubule protein. Pretreatment of 2'- and 7-phosphonoxyphenylpropionate prodrugs BMS180661 and BMS180820 with alkaline phosphatase for 30 to 120 min yielded relative initial slopes of about 20 to 100% at test concentrations equimolar to paclitaxel. High-performance liquid chromatography/mass spectrometry of BMS180661 treated with alkaline phosphatase confirmed the production of paclitaxel from the prodrug. In contrast, 2'- and 7-phosphate analogs BMY46366 and BMY46489 treated with alkaline phosphatase were not active in tubulin assays. None of the paclitaxel phosphate prodrugs polymerized tubulin in the absence of metabolic activation. The differences in tubulin polymerization with metabolic activation may be related both to accessibility of the phosphate group to the enzyme and to anionic charge effects. These results demonstrate that certain paclitaxel phosphate prodrugs can be metabolized by alkaline phosphatase to yield effective tubulin polymerization.

  19. Orexin activation precedes increased NPY expression, hyperphagia, and metabolic changes in response to sleep deprivation

    OpenAIRE

    Forcina Martins, Paulo Jose [UNIFESP; Marques, Marina Soares [UNIFESP; Tufik, Sergio; D'Almeida, Vania

    2010-01-01

    Martins PJ, Marques MS, Tufik S, D'Almeida V. Orexin activation precedes increased NPY expression, hyperphagia, and metabolic changes in response to sleep deprivation. Am J Physiol Endocrinol Metab 298: E726-E734, 2010. First published January 5, 2010; doi:10.1152/ajpendo.00660.2009.-Several pieces of evidence support that sleep duration plays a role in body weight control. Nevertheless, it has been assumed that, after the identification of orexins (hypocretins), the molecular basis of the in...

  20. A high-throughput method for quantifying metabolically active yeast cells

    DEFF Research Database (Denmark)

    Nandy, Subir Kumar; Knudsen, Peter Boldsen; Rosenkjær, Alexander

    2015-01-01

    By redesigning the established methylene blue reduction test for bacteria and yeast, we present a cheap and efficient methodology for quantitative physiology of eukaryotic cells applicable for high-throughput systems. Validation of themethod in fermenters and highthroughput systems proved...... equivalent, displaying reduction curves that interrelated directly with CFU counts. For growth rate estimation, the methylene blue reduction test (MBRT) proved superior, since the discriminatory nature of the method allowed for the quantification of metabolically active cells only, excluding dead cells...

  1. [Conception for permanent activation of nuclear factor kbeta as molecular basis for metabolic syndrom pathogenesis].

    Science.gov (United States)

    Kaidashev, I P

    2013-01-01

    The analysis of new data concerning the development of pathology due to the community of evolutionary new pathological factors was done. Author provides the comparison of well-known and new definition for "metabolic syndrome" and diagnostic criteria of this pathology. The conception for permanent activation of nuclear factor kbeta as possible typic pathological process was discussed. Suppose that NF-kbeta is the possible key molecule in the initiation and formation of "vicious circle"--insulinresistance--inflammation--atherosclerosis.

  2. Discrepancies between metabolic activity and DNA content as tool to assess cell proliferation in cancer research

    OpenAIRE

    Quent, Verena MC; Loessner, Daniela; Friis, Thor; Reichert, Johannes C.; Hutmacher, Dietmar W.

    2010-01-01

    Abstract Cell proliferation is a critical and frequently studied feature of molecular biology in cancer research. Therefore, various assays are available using different strategies to measure cell proliferation. Metabolic assays such as AlamarBlue, water-soluble tetrazolium salt and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, which were originally developed to determine cell toxicity, are used to assess cell numbers. Additionally, proliferative activity can be determined by...

  3. Enzyme activities and gene expression of starch metabolism provide insights into grape berry development.

    Science.gov (United States)

    Zhu, Xudong; Zhang, Chaobo; Wu, Weimin; Li, Xiaopeng; Zhang, Chuan; Fang, Jinggui

    2017-01-01

    Grapes are categorized as a non-climacteric type of fruit which its ripening is not associated to important rises in respiration and ethylene synthesis. The starch metabolism shares a certain role in the carbohydrate metabolic pathways during grape berry development, and is regarded as an important transient pool in the pathway of sugar accumulation. However, the comprehensive role of starch and its contribution to the quality and flavor of grape berry have not been explored thoroughly. In this study, the expression levels of genes enzyme activities and carbohydrate concentrations related to starch metabolism, were analyzed to understand the molecular mechanism of starch accumulation during grape berry development. The results indicated that starch granules in grape berry were located at the chloroplast in the sub-epidermal tissues, acting as the temporary reserves of photosynthetic products to meet the needs for berry development, and relatively high starch contents could be detected at véraison stage. Moreover, both ADP-glucose pyrophosphorylase (EC 2.7.7.27) and sucrose phosphate synthase (EC 2.3.1.14) involved in starch synthesis displayed elevated gene expression and enzymes activities in the sub-epidermal tissue, while α- and β-amylases involved in its degradation were highly transcribed and active in the central flesh, explaining the absence of starch in this last tissue. Change in the gene expression and activities of ADP-glucose pyrophosphorylase, β-amylase and sucrose phosphate synthase revealed that they were regulated by the circadian rhythms in the fruitlets compared with those in the leaves. Both the morphological, enzymological and transcriptional data in this study provide advanced understandings on the function of starch during berry development and ripening that are so important for berry quality. This study will further facilitate our understanding of the sugar metabolism in grape berry as well as in other plant species.

  4. [Interaction between CYP450 enzymes and metabolism of traditional Chinese medicine as well as enzyme activity assay].

    Science.gov (United States)

    Lu, Tu-lin; Su, Lian-lin; Ji, De; Gu, Wei; Mao, Chun-qin

    2015-09-01

    Drugs are exogenous compounds for human bodies, and will be metabolized by many enzymes after administration. CYP450 enzyme, as a major metabolic enzyme, is an important phase I drug metabolizing enzyme. In human bodies, about 75% of drug metabolism is conducted by CYP450 enzymes, and CYP450 enzymes is the key factor for drug interactions between traditional Chinese medicine( TCM) -TCM, TCM-medicine and other drug combination. In order to make clear the interaction between metabolic enzymes and TCM metabolism, we generally chose the enzymatic activity as an evaluation index. That is to say, the enhancement or reduction of CYP450 enzyme activity was used to infer the inducing or inhibitory effect of active ingredients and extracts of traditional Chinese medicine on enzymes. At present, the common method for measuring metabolic enzyme activity is Cocktail probe drugs, and it is the key to select the suitable probe substrates. This is of great significance for study drug's absorption, distribution, metabolism and excretion (ADME) process in organisms. The study focuses on the interaction between TCMs, active ingredients, herbal extracts, cocktail probe substrates as well as CYP450 enzymes, in order to guide future studies.

  5. Relation Between Metabolic Activity of the Broca Region and F-18 FDG Uptake in Vocal Cords.

    Science.gov (United States)

    Eren, Mine Şencan; Durak, Hatice

    2012-08-01

    We aimed to investigate if increased F-18 Fluoro Deoxyglucose (F-18 FDG) uptake observed in vocal cords (VC) of the patients on Positron Emission Tomography/Computarize Tomography (PET/CT) scans is connected to speaking of the patients or not. If so, we expected to detect an increased metabolic activity in Broca's area. In this study, we have retrospectively searched for a correlation between the activity in the Broca's area and vocal cords of patients who had undergone FDG PET for different indications. FDG PET/CT scans of 30 patients with (VC [+]) and 30 patients without (VC [-]) bilateral F-18 FDG uptake on their vocal cords were retrospectively evaluated. Brain quantification was carried out on NeuroQ software with 20 iterations using patients' transaxial brain cross sections. On the 20th-23rd-26th-29th cross sections, area/whole brain ratios of the right (R) and left (L) for Broca's area were calculated. VC (+) and VC (-) patients' R and L Broca's areas were compared using Student's t-test. There was no significant difference between the Broca's areas of VC (+) and VC (-) patients. L Broca's areas of both VC (+) and VC (-) patients were more active than R Broca's areas (pBroca's region. In our study, we did not find a significant difference between Broca's areas of VC (+) patients and VC (-) patients, so the activity in their vocal cords does not seem to be related to increased metabolic activity in Broca's areas. We have concluded that the vocal cord activity is not related to speaking of the patients. The activity in the vocal cord might be due to inflammation or, as in the eye muscles, may be associated with high metabolism in laryngeal muscles. None declared.

  6. Stochastic Resonance Activity Influences Serum Tryptophan Metabolism in Healthy Human Subjects

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    Berthold Kepplinger

    2011-01-01

    Full Text Available Background Stochastic resonance therapy (SRT is used for rehabilitation of patients with various neuropsychiatric diseases. An alteration in tryptophan metabolism along the kynurenine pathway has been identified in the central and peripheral nervous systems in patients with neuroinflammatory and neurodegenerative diseases and during the aging process. This study investigated the effect of SRT as an exercise activity on serum tryptophan metabolites in healthy subjects. Methods Serum L-tryptophan, L-kynurenine, kynurenic acid, and anthranilic acid levels were measured one minute before SRT and at one, 5, 15, 30, and 60 minutes after SRT. We found that SRT affected tryptophan metabolism. Serum levels of L-tryptophan, L-kynurenine, and kynurenic acid were significantly reduced for up to 60 minutes after SRT. Anthranilic acid levels were characterized by a moderate, non significant transient decrease for up to 15 minutes, followed by normalization at 60 minutes. Tryptophan metabolite ratios were moderately altered, suggesting activation of metabolism after SRT. Lowering of tryptophan would generally involve activation of tryptophan catabolism and neurotransmitter, protein, and bone biosynthesis. Lowering of kynurenic acid by SRT might be relevant for improving symptoms in patients with neuropsychiatric disorders, such as Parkinson's disease, Alzheimer's disease, schizophrenia, and depression, as well as certain pain conditions.

  7. Glucose deprivation activates a metabolic and signaling amplification loop leading to cell death

    Science.gov (United States)

    Graham, Nicholas A; Tahmasian, Martik; Kohli, Bitika; Komisopoulou, Evangelia; Zhu, Maggie; Vivanco, Igor; Teitell, Michael A; Wu, Hong; Ribas, Antoni; Lo, Roger S; Mellinghoff, Ingo K; Mischel, Paul S; Graeber, Thomas G

    2012-01-01

    The altered metabolism of cancer can render cells dependent on the availability of metabolic substrates for viability. Investigating the signaling mechanisms underlying cell death in cells dependent upon glucose for survival, we demonstrate that glucose withdrawal rapidly induces supra-physiological levels of phospho-tyrosine signaling, even in cells expressing constitutively active tyrosine kinases. Using unbiased mass spectrometry-based phospho-proteomics, we show that glucose withdrawal initiates a unique signature of phospho-tyrosine activation that is associated with focal adhesions. Building upon this observation, we demonstrate that glucose withdrawal activates a positive feedback loop involving generation of reactive oxygen species (ROS) by NADPH oxidase and mitochondria, inhibition of protein tyrosine phosphatases by oxidation, and increased tyrosine kinase signaling. In cells dependent on glucose for survival, glucose withdrawal-induced ROS generation and tyrosine kinase signaling synergize to amplify ROS levels, ultimately resulting in ROS-mediated cell death. Taken together, these findings illustrate the systems-level cross-talk between metabolism and signaling in the maintenance of cancer cell homeostasis. PMID:22735335

  8. Metabolic activity and functional diversity changes in sediment prokaryotic communities organically enriched with mussel biodeposits.

    Science.gov (United States)

    Pollet, Thomas; Cloutier, Olivier; Nozais, Christian; McKindsey, Christopher W; Archambault, Philippe

    2015-01-01

    This experimental microcosm study reports the influence of organic enrichments by mussel biodeposits on the metabolic activity and functional diversity of benthic prokaryotic communities. The different biodeposit enrichment regimes created, which mimicked the quantity of faeces and pseudo-faeces potentially deposited below mussel farms, show a clear stimulatory effect of this organic enrichment on prokaryotic metabolic activity. This effect was detected once a certain level of biodeposition was attained with a tipping point estimated between 3.25 and 10 g day-1 m-2. Prokaryotic communities recovered their initial metabolic activity by 11 days after the cessation of biodeposit additions. However, their functional diversity remained greater than prior to the disturbance suggesting that mussel biodeposit enrichment may disturb the functioning and perhaps the role of prokaryotic communities in benthic ecosystems. This manipulative approach provided new information on the influence of mussel biodeposition on benthic prokaryotic communities and dose-response relationships and may support the development of carrying capacity models for bivalve culture.

  9. Physical Activity and Sedentary Behavior in Metabolically Healthy versus Unhealthy Obese and Non-Obese Individuals - The Maastricht Study.

    Directory of Open Access Journals (Sweden)

    Belle H de Rooij

    Full Text Available Both obesity and the metabolic syndrome are associated with increased risk of cardiovascular diseases and type 2 diabetes. Although both frequently occur together in the same individual, obesity and the metabolic syndrome can also develop independently from each other. The (pathophysiology of "metabolically healthy obese" (i.e. obese without metabolic syndrome and "metabolically unhealthy non-obese" phenotypes (i.e. non-obese with metabolic syndrome is not fully understood, but physical activity and sedentary behavior may play a role.To examine objectively measured physical activity and sedentary behavior across four groups: I "metabolically healthy obese" (MHO; II "metabolically unhealthy obese" (MUO; III"metabolically healthy non-obese" (MHNO; and IV "metabolically unhealthy non-obese" (MUNO.Data were available from 2,449 men and women aged 40-75 years who participated in The Maastricht Study from 2010 to 2013. Participants were classified into the four groups according to obesity (BMI≥30kg/m2 and metabolic syndrome (ATPIII definition. Daily activity was measured for 7 days with the activPAL physical activity monitor and classified as time spent sitting, standing, and stepping.In our study population, 562 individuals were obese. 19.4% of the obese individuals and 72.7% of the non-obese individuals was metabolically healthy. After adjustments for age, sex, educational level, smoking, alcohol use, waking time, T2DM, history of CVD and mobility limitation, MHO (n = 107 spent, per day, more time stepping (118.2 versus 105.2 min; p<0.01 and less time sedentary (563.5 versus 593.0 min., p = 0.02 than MUO (n = 440. In parallel, MHNO (n = 1384 spent more time stepping (125.0 versus 115.4 min; p<0.01 and less time sedentary (553.3 versus 576.6 min., p<0.01 than MUNO (n = 518.Overall, the metabolically healthy groups were less sedentary and more physically active than the metabolically unhealthy groups. Therefore, physical activity and sedentary time

  10. Metabolic activity in dormant conidia of Aspergillus niger and developmental changes during conidial outgrowth.

    Science.gov (United States)

    Novodvorska, Michaela; Stratford, Malcolm; Blythe, Martin J; Wilson, Raymond; Beniston, Richard G; Archer, David B

    2016-09-01

    The early stages of development of Aspergillus niger conidia during outgrowth were explored by combining genome-wide gene expression analysis (RNAseq), proteomics, Warburg manometry and uptake studies. Resting conidia suspended in water were demonstrated for the first time to be metabolically active as low levels of oxygen uptake and the generation of carbon dioxide were detected, suggesting that low-level respiratory metabolism occurs in conidia for maintenance. Upon triggering of spore germination, generation of CO2 increased dramatically. For a short period, which coincided with mobilisation of the intracellular polyol, trehalose, there was no increase in uptake of O2 indicating that trehalose was metabolised by fermentation. Data from genome-wide mRNA profiling showed the presence of transcripts associated with fermentative and respiratory metabolism in resting conidia. Following triggering of conidial outgrowth, there was a clear switch to respiration after 25min, confirmed by cyanide inhibition. No effect of SHAM, salicylhydroxamic acid, on respiration suggests electron flow via cytochrome c oxidase. Glucose entry into spores was not detectable before 1h after triggering germination. The impact of sorbic acid on germination was examined and we showed that it inhibits glucose uptake. O2 uptake was also inhibited, delaying the onset of respiration and extending the period of fermentation. In conclusion, we show that conidia suspended in water are not completely dormant and that conidial outgrowth involves fermentative metabolism that precedes respiration. Copyright © 2016. Published by Elsevier Inc.

  11. Metabolic transistor strategy for controlling electron transfer chain activity in Escherichia coli.

    Science.gov (United States)

    Wu, Hui; Tuli, Leepika; Bennett, George N; San, Ka-Yiu

    2015-03-01

    A novel strategy to finely control a large metabolic flux by using a "metabolic transistor" approach was established. In this approach a small change in the level or availability of an essential component for the process is controlled by adding a competitive reaction that affects a precursor or an intermediate in its biosynthetic pathway. The change of the basal level of the essential component, considered as a base current in a transistor, has a large effect on the flux through the major pathway. In this way, the fine-tuning of a large flux can be accomplished. The "metabolic transistor" strategy was applied to control electron transfer chain function by manipulation of the quinone synthesis pathway in Escherichia coli. The achievement of a theoretical yield of lactate production under aerobic conditions via this strategy upon manipulation of the biosynthetic pathway of the key participant, ubiquinone-8 (Q8), in an E. coli strain provides an in vivo, genetically tunable means to control the activity of the electron transfer chain and manipulate the production of reduced products while limiting consumption of oxygen to a defined amount. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  12. Influence of immediate and early loading on bone metabolic activity around dental implants in rat tibiae.

    Science.gov (United States)

    Yamamoto, Miou; Ogawa, Toru; Yokoyama, Masayoshi; Koyama, Shigeto; Sasaki, Keiichi

    2014-09-01

    The aim of this study was to examine the influence of immediate and early loading on dynamic changes in bone metabolism around dental implants using bone scintigraphy. Two titanium implants were inserted in the right tibiae of 21 rats. Closed coil springs with 4.0-N loads were applied parallel to the upper portion of the implants for 35 days. According to the load application timing, rats were divided into three groups: immediate loading (IL) group, early loading 1 day after implant insertion (1-D early loading [EL]) group, and loading 3 days after implant insertion (3-D EL) group. Rats were intravenously injected with technetium-99 m-methylene diphosphonate (Tc99 m-MDP) (74 MBq/rat) and scanned by bone scintigraphy at 1, 4, 7, 11, 14, 21, 28, and 35 days after load application. The ratio of accumulation of Tc99 m-MDP around the implants to that of a reference site (uptake ratio) was calculated to evaluate bone metabolism. In every group, the uptake ratio increased until 7 days after load application and then gradually decreased. It was significantly higher than baseline at 4, 7, 11, and 14 days (P load timing. Increases in bone metabolic activity differed according to load application timing; the later the load application, the more enhanced the bone metabolism. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Rhodiola crenulata extract regulates hepatic glycogen and lipid metabolism via activation of the AMPK pathway.

    Science.gov (United States)

    Lin, Kuen-Tze; Hsu, Shih-Wei; Lai, Feng-Yi; Chang, Tsu-Chung; Shi, Li-Shian; Lee, Shih-Yu

    2016-05-17

    Metabolic syndrome may lead to many complications, such as nonalcoholic fatty liver disease (NAFLD). A natural and effective therapeutic agent for patients with NAFLD is urgently needed. In a previous study, we showed that Rhodiola crenulata root extract (RCE) regulated hepatic gluconeogenesis through activation of AMPK signaling. However, the manner in which RCE regulates hepatic lipid and glycogen metabolism remains unclear. The current study was conducted to investigate the effects of RCE on hepatic glycogen and lipid metabolism, as well as the mechanisms underlying such effects. Human hepatoma HepG2 cells were treated with RCE for 6 h under high glucose conditions, after which glycogen synthesis, lipogenesis, and relative gene expression were examined. In addition, lipogenesis-related genes were investigated in vivo. RCE significantly increased glycogen synthesis and inhibited lipogenesis, while regulating genes related to these processes, including glycogen synthase kinase 3β (GSK3β), glycogen synthase (GS), fatty acid synthase (FAS), CCAAT/enhancer-binding protein (C/EBP), and sterol regulatory element-binding protein 1c (SREBP-1c). However, the effects caused by RCE were neutralized by compound C, an AMPK antagonist. Further studies showed that expression levels of lipogenic genes decreased at the protein and mRNA levels in the rat liver. Our results demonstrate that RCE regulates hepatic glycogen and lipid metabolism through the AMPK signaling pathway. These results suggest that RCE is a potential intervention for patients with NAFLD.

  14. Chronic activation of the innate immune system may underlie the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Bruce Bartholow Duncan

    2001-05-01

    Full Text Available CONTEXTO: The metabolic syndrome is characterized by a clustering, in free-living populations, of cardiovascular and diabetes risk factors generally linked to insulin resistance, obesity and central obesity. Consonant with the well-established inflammatory pathogenesis of atherosclerotic disease, the metabolic syndrome is now being investigated in relation to its inflammatory nature. OBJETIVO: We present cross-sectional findings demonstrating that markers of inflammation correlate with components of the metabolic syndrome, and prospective findings of the ARIC Study indicating that markers of inflammation and endothelial dysfunction predict the development of diabetes mellitus and weight gain in adults. We present biological evidence to suggest that chronic activation of the innate immune system may underlie the metabolic syndrome, characterizing the common soil for the causality of type 2 diabetes mellitus and cardiovascular disease. CONCLUSIONS: Better understanding of the role of the innate immune system in these diseases may lead to important advances in the prediction and management of diabetes and cardiovascular disease.

  15. Moderate physical activity level as a protective factor against metabolic syndrome in middle-aged and older women.

    Science.gov (United States)

    Lin, Chia-Huei; Chiang, Shang-Lin; Yates, Patsy; Lee, Meei-Shyuan; Hung, Yi-Jen; Tzeng, Wen-Chii; Chiang, Li-Chi

    2015-05-01

    To investigate whether physical activity is a protective factor against metabolic syndrome in middle-aged and older women. Socio-demographic and lifestyle behaviour factors contribute to metabolic syndrome. To minimise the risk of metabolic syndrome, several global guidelines recommend increasing physical activity level. However, only limited research has investigated the relationship between physical activity levels and metabolic syndrome in middle-aged and older women after adjusting for socio-demographic and lifestyle behaviour factors. Cross-sectional design. A convenience sample of 326 middle-aged and older women was recruited. Metabolic syndrome was confirmed according to the National Cholesterol Education Program, Adult Treatment Panel III guidelines, and physical activity levels were measured by the International Physical Activity Questionnaire. The sample had a mean age of 60·9 years, and the prevalence of metabolic syndrome was 43·3%. Postmenopausal women and women with low socioeconomic status (low-education background, without personal income and currently unemployed) had a significantly higher risk of developing metabolic syndrome. After adjusting for significant socio-demographic and lifestyle behaviour factors, the women with moderate or high physical activity levels had a significantly lower (OR = 0·10; OR = 0·11, p aged and older women. Higher physical activity levels (moderate or high physical activity level) reduced the risk of metabolic syndrome in middle-aged and older women. Appropriate strategies should be developed to encourage middle-aged and older women across different socio-demographic backgrounds to engage in moderate or high levels of physical activity to reduce the risk of metabolic syndrome. © 2014 John Wiley & Sons Ltd.

  16. Pregnancy-related changes in activity energy expenditure and resting metabolic rate in Switzerland.

    Science.gov (United States)

    Melzer, K; Schutz, Y; Boulvain, M; Kayser, B

    2009-10-01

    To measure resting metabolic rate (RMR), activity energy expenditure (AEE), total energy expenditure (TEE) and physical activity pattern, that is, duration and intensity (in metabolic equivalents, METs) of activities performed in late pregnancy compared with postpartum in healthy, well-nourished women living in Switzerland. Weight, height, RMR, AEE, TEE and physical activity patterns were measured longitudinally in 27 healthy women aged 23-40 years at 38.2+/-1.5 weeks of gestation and 40.0+/-7.2 weeks postpartum. The RMR during late pregnancy was 7480 kJ per day, that is, 1320+/-760 kJ per day (21.4%) higher than the postpartum RMR (P or =6 (1 vs 6 min, P=0.014) during pregnancy and postpartum, respectively. Energy expenditure in healthy women living in Switzerland increases in pregnancy compared with the postpartum state. Additional energy expenditure is primarily attributed to an increase in RMR, which is partly compensated by a decrease in AEE. The decrease in physical activity-related energy costs is achieved by selecting less demanding activities and should be taken into account when defining extra energy requirements for late pregnancy in Switzerland.

  17. Genetic expression of aflatoxin metabolism. Effects of 3-methylcholanthrene and beta-naphthoflavone on hepatic microsomal metabolism and mutagenic activation of aflatoxins.

    Science.gov (United States)

    Raina, V; Williams, C J; Gurtoo, H L

    1983-12-15

    The effects of pretreatment with 3-methylcholanthrene (MC) and beta-naphthoflavone (beta NF) on the hepatic microsome-mediated mutagenesis of aflatoxin B1 (AFB1) and benzo[a]pyrene, and on the metabolism of aflatoxins B1 and B2, were investigated in inbred mouse strains. The inbred strains of mice studied included Ah nonresponsive strains (DBA/2Ha, AKR/Sn and RF/J), which were also nonresponsive to the induction of the metabolism of AFB1 to AFM1 (AFB1-4-hydroxylase activity), and Ah responsive strains (C57BL/6Ha, ICR/Ha, C3H/St, A/St, Balb/cCr, C57e/Ha and CBA/Pi), which were also responsive to the induction of AFB1-4-hydroxylase activity. The hepatic microsome-mediated enzyme activities studied included: mutagenic activation of AFB1 and benzo[a]pyrene in the Ames Salmonella typhimurium TA-98 system; metabolism of AFB1 and AFB2 to AFM1 and AFM2, respectively; and benzo[a]pyrene metabolism measured as the formation of fluorescent phenolic metabolites, i.e. aryl hydrocarbon hydroxylase (AHH) activity. Time-course and dose-response studies in C57BL/6Ha mice revealed that the metabolism of aflatoxin B1/B2 to aflatoxin M1/M2 (AFB1/B2-4-hydroxylase activity) was induced by both MC and beta NF. In the nonresponsive strains studied, pretreatment with MC or beta NF produced essentially little alteration of AFB1-4-hydroxylase activity or AHH activity or the mutagenic activation of AFB1 and benzo[a]pyrene. On the other hand, AFB1-4-hydroxylase activity in the responsive strains was induced 4- to 10-fold by MC (60 mg/kg) and 2.5- to 7-fold by beta NF (150 mg/kg). Also in the responsive strains, induction of AFB1-4-hydroxylase activity was strongly associated with (a) the depression of the mutagenic activation of AFB1, and (b) with the induction of both AHH and the mutagenic activation of benzo[a]pyrene. In summary, the results described in this report suggest that: (a) induction of AFB1-4-hydroxylase activity by MC (or beta NF) is associated with the depression of AFB1

  18. Compartment-specific activation of PPARγ governs breast cancer tumor growth, via metabolic reprogramming and symbiosis.

    Science.gov (United States)

    Avena, Paola; Anselmo, Wanda; Whitaker-Menezes, Diana; Wang, Chenguang; Pestell, Richard G; Lamb, Rebecca S; Hulit, James; Casaburi, Ivan; Andò, Sebastiano; Martinez-Outschoorn, Ubaldo E; Lisanti, Michael P; Sotgia, Federica

    2013-05-01

    The role of PPARγ in cancer therapy is controversial, with studies showing either pro-tumorigenic or antineoplastic effects. This debate is very clinically relevant, because PPARγ agonists are used as antidiabetic drugs. Here, we evaluated if the effects of PPARγ on tumorigenesis are determined by the cell type in which PPARγ is activated. Second, we examined if the metabolic changes induced by PPARγ, such as glycolysis and autophagy, play any role in the tumorigenic process. To this end, PPARγ was overexpressed in breast cancer cells or in stromal cells. PPARγ-overexpressing cells were examined with respect to (1) their tumorigenic potential, using xenograft models, and (2) regarding their metabolic features. In xenograft models, we show that when PPARγ is activated in cancer cells, tumor growth is inhibited by 40%. However, when PPARγ is activated in stromal cells, the growth of co-injected breast cancer cells is enhanced by 60%. Thus, the effect(s) of PPARγ on tumorigenesis are dependent on the cell compartment in which PPARγ is activated. Mechanistically, stromal cells with activated PPARγ display metabolic features of cancer-associated fibroblasts, with increased autophagy, glycolysis and senescence. Indeed, fibroblasts overexpressing PPARγ show increased expression of autophagic markers, increased numbers of acidic autophagic vacuoles, increased production of L-lactate, cell hypertrophy and mitochondrial dysfunction. In addition, PPARγ fibroblasts show increased expression of CDKs (p16/p21) and β-galactosidase, which are markers of cell cycle arrest and senescence. Finally, PPARγ induces the activation of the two major transcription factors that promote autophagy and glycolysis, i.e., HIF-1α and NFκB, in stromal cells. Thus, PPARγ activation in stromal cells results in the formation of a catabolic pro-inflammatory microenvironment that metabolically supports cancer growth. Interestingly, the tumor inhibition observed when PPARγ is

  19. Effect of contrasted levels of habitual physical activity on metabolic flexibility.

    Science.gov (United States)

    Bergouignan, Audrey; Antoun, Edwina; Momken, Iman; Schoeller, Dale A; Gauquelin-Koch, Guillemette; Simon, Chantal; Blanc, Stéphane

    2013-02-01

    The factors regulating the body's ability to switch from fat to carbohydrate oxidation in response to fuel availability changes, or metabolic flexibility (MF), are currently intensively investigated in the context of metabolic diseases. Although numerous metabolic diseases are associated with sedentary behaviors and metabolic inflexibility, the effect of habitual physical activity level (PAL) on MF regulation is surprisingly poorly known. We investigated how PAL affects MF in cross-sectional and interventional studies. MF was assessed in 44 subjects: normal-weight and overweight sedentary men submitted to 2 mo of exercise at current recommendations, normal-weight active men submitted to 1 mo of reduced PAL and normal-weight women submitted to 1 mo of bed rest, with or without exercise. MF was evaluated, before and after interventions, following two standard meals as the relationship between individual mathematical variances in insulin and nonprotein respiratory quotient (NPRQ) daily kinetics. Daily NPRQ and insulin variances differed according to habitual PAL (P = 0.002 and P = 0.009, respectively); active subjects had higher variances in NPRQ for lower variances in insulin than sedentary subjects, indicating a better MF. Detraining increased insulin variance (P = 0.009) and decreased NPRQ variance (P = 0.003), while training tended to have opposite effects. Insulin and NPRQ variances were negatively related along the PAL continuum (R(2) = 0.70, P < 0.001). Variance in NPRQ was also positively related to PAL (R(2) = 0.52, P < 0.001). By assessing MF with mathematical surrogates in conditions of daily pattern in meal's intake, we showed that habitual PAL is associated with MF status, and that MF is modulated by changes in PAL.

  20. Green tea extract activates AMPK and ameliorates white adipose tissue metabolic dysfunction induced by obesity.

    Science.gov (United States)

    Rocha, Andréa; Bolin, Anaysa Paola; Cardoso, Claudia Andrea Lima; Otton, Rosemari

    2016-10-01

    Beneficial effects of green tea (GT) polyphenols against obesity have been reported. However, until this moment the molecular mechanisms of how green tea can modulate obesity and regulates fat metabolism, particularly in adipose tissue, remain poorly understood. The aim of this study was to evaluate the role of GT extract in the adipose tissue of obese animals and its effect on weight gain, metabolism and function (de novo lipogenesis and lipolysis), and the involvement of AMP-activated protein kinase (AMPK). Male Wistar rats were treated with GT by gavage (12 weeks/5 days/week; 500 mg/kg of body weight), and obesity was induced by cafeteria diet (8 weeks). Here, we show that obese rats treated with GT showed a significant reduction in indicators of obesity such as hyperlipidemia, fat synthesis, body weight, and fat depots as compared to those treated with standard control diet. AMPK was induced in adipose tissue in rats that were treated with GT and likely restored insulin sensitivity, increased mRNA expression of GLUT4, reducing the concentrations of plasma and liver lipid content, also stimulating fatty acid oxidation in the same tissue. Importantly, repression of de novo lipogenesis in the adipose tissue, reduced lipid droplets in the liver, and the development of insulin resistance in diet-induced obese rats were accompanied by AMPK activation. Our study identified that metabolic changes caused by GT intake induced AMPK activation and modulate the expression of genes involved in metabolism, particularly in adipose tissue, thus offering a therapeutic strategy to combat insulin resistance, dyslipidemia, and obesity in rats.

  1. Glycoprotein Ib activation by thrombin stimulates the energy metabolism in human platelets.

    Science.gov (United States)

    Corona de la Peña, Norma; Gutiérrez-Aguilar, Manuel; Hernández-Reséndiz, Ileana; Marín-Hernández, Álvaro; Rodríguez-Enríquez, Sara

    2017-01-01

    Thrombin-induced platelet activation requires substantial amounts of ATP. However, the specific contribution of each ATP-generating pathway i.e., oxidative phosphorylation (OxPhos) versus glycolysis and the biochemical mechanisms involved in the thrombin-induced activation of energy metabolism remain unclear. Here we report an integral analysis on the role of both energy pathways in human platelets activated by several agonists, and the signal transducing mechanisms associated with such activation. We found that thrombin, Trap-6, arachidonic acid, collagen, A23187, epinephrine and ADP significantly increased glycolytic flux (3-38 times vs. non-activated platelets) whereas ristocetin was ineffective. OxPhos (33 times) and mitochondrial transmembrane potential (88%) were increased only by thrombin. OxPhos was the main source of ATP in thrombin-activated platelets, whereas in platelets activated by any of the other agonists, glycolysis was the principal ATP supplier. In order to establish the biochemical mechanisms involved in the thrombin-induced OxPhos activation in platelets, several signaling pathways associated with mitochondrial activation were analyzed. Wortmannin and LY294002 (PI3K/Akt pathway inhibitors), ristocetin and heparin (GPIb inhibitors) as well as resveratrol, ATP (calcium-release inhibitors) and PP1 (Tyr-phosphorylation inhibitor) prevented the thrombin-induced platelet activation. These results suggest that thrombin activates OxPhos and glycolysis through GPIb-dependent signaling involving PI3K and Akt activation, calcium mobilization and protein phosphorylation.

  2. Glycoprotein Ib activation by thrombin stimulates the energy metabolism in human platelets

    Science.gov (United States)

    Corona de la Peña, Norma; Gutiérrez-Aguilar, Manuel; Hernández-Reséndiz, Ileana; Marín-Hernández, Álvaro

    2017-01-01

    Thrombin-induced platelet activation requires substantial amounts of ATP. However, the specific contribution of each ATP-generating pathway i.e., oxidative phosphorylation (OxPhos) versus glycolysis and the biochemical mechanisms involved in the thrombin-induced activation of energy metabolism remain unclear. Here we report an integral analysis on the role of both energy pathways in human platelets activated by several agonists, and the signal transducing mechanisms associated with such activation. We found that thrombin, Trap-6, arachidonic acid, collagen, A23187, epinephrine and ADP significantly increased glycolytic flux (3–38 times vs. non-activated platelets) whereas ristocetin was ineffective. OxPhos (33 times) and mitochondrial transmembrane potential (88%) were increased only by thrombin. OxPhos was the main source of ATP in thrombin-activated platelets, whereas in platelets activated by any of the other agonists, glycolysis was the principal ATP supplier. In order to establish the biochemical mechanisms involved in the thrombin-induced OxPhos activation in platelets, several signaling pathways associated with mitochondrial activation were analyzed. Wortmannin and LY294002 (PI3K/Akt pathway inhibitors), ristocetin and heparin (GPIb inhibitors) as well as resveratrol, ATP (calcium-release inhibitors) and PP1 (Tyr-phosphorylation inhibitor) prevented the thrombin-induced platelet activation. These results suggest that thrombin activates OxPhos and glycolysis through GPIb-dependent signaling involving PI3K and Akt activation, calcium mobilization and protein phosphorylation. PMID:28817667

  3. Testosterone affects hormone-sensitive lipase (HSL) activity and lipid metabolism in the left ventricle

    DEFF Research Database (Denmark)

    Langfort, Jozef; Jagsz, Slawomir; Dobrzyn, Pawel

    2010-01-01

    levels, caused an inhibitory effect on carbohydrate metabolism in the heart, and elevated left ventricular phosphocreatine and ATP levels as compared to control rats. These data indicate that testosterone is involved in cardiac HSL activity regulation which, in turn, may affect cardiac lipid...... tissue suggests that testosterone regulates HSL activity. To test whether this is also true in the heart, we measured HSL activity in the left ventricle of sedentary male rats that had been treated with testosterone supplementation or orchidectomy with or without testosterone substitution. Left ventricle...... HSL activity against TG was significantly elevated in intact rats supplemented with testosterone. HSL activity against both TG and diacylglyceride was reduced by orchidectomy, whereas testosterone replacement fully reversed this effect. Moreover, testosterone increased left ventricle free fatty acid...

  4. Testosterone affects hormone-sensitive lipase (HSL) activity and lipid metabolism in the left ventricle

    DEFF Research Database (Denmark)

    Langfort, Jozef; Jagsz, Slawomir; Dobrzyn, Pawel

    2010-01-01

    tissue suggests that testosterone regulates HSL activity. To test whether this is also true in the heart, we measured HSL activity in the left ventricle of sedentary male rats that had been treated with testosterone supplementation or orchidectomy with or without testosterone substitution. Left ventricle...... HSL activity against TG was significantly elevated in intact rats supplemented with testosterone. HSL activity against both TG and diacylglyceride was reduced by orchidectomy, whereas testosterone replacement fully reversed this effect. Moreover, testosterone increased left ventricle free fatty acid...... levels, caused an inhibitory effect on carbohydrate metabolism in the heart, and elevated left ventricular phosphocreatine and ATP levels as compared to control rats. These data indicate that testosterone is involved in cardiac HSL activity regulation which, in turn, may affect cardiac lipid...

  5. Glucose-functionalized gold nanoparticles as a metabolically targeted CT contrast agent for distinguishing tumors from non-malignant metabolically active processes

    Science.gov (United States)

    Dreifuss, Tamar; Motiei, Menachem; Betzer, Oshra; Popovtzer, Aron; Abourbeh, Galith; Mishani, Eyal; Popovtzer, Rachela

    2017-02-01

    The highly used cancer imaging technique, [18F]FDG-PET, is based on the increased glucose metabolic activity in tumors. However, since there are other biological processes that exhibit increased metabolic activity, in particular inflammation, this methodology is prone to non-specificity for cancer. Herein we describe the development of a novel nanoparticle-based approach, utilizes Glucose-Functionalized Gold Nanoparticles (GF-GNPs) as a metabolically targeted CT contrast agent. Our method has demonstrated specific tumor targeting and has successfully differentiated between cancer and inflammation in a combined tumor-inflammation mouse model, due to dissimilarities in vasculatures in different pathologic conditions. This novel approach provides new capabilities in cancer imaging, and can be applicable to a wide range of cancers.

  6. Salivary pellicles on titanium and their effect on metabolic activity in Streptococcus oralis

    Science.gov (United States)

    2013-01-01

    Background Titanium implants in the oral cavity are covered with a saliva-derived pellicle to which early colonizing microorganisms such as Streptococcus oralis can bind. The protein profiles of salivary pellicles on titanium have not been well characterized and the proteins of importance for binding are thus unknown. Biofilm bacteria exhibit different phenotypes from their planktonic counterparts and contact with salivary proteins may be one factor contributing to the induction of changes in physiology. We have characterized salivary pellicles from titanium surfaces and investigated how contact with uncoated and saliva-coated titanium surfaces affects metabolic activity in adherent cells of S. oralis. Methods Salivary pellicles on smooth titanium surfaces were desorbed and these, as well as purified human saliva, were subjected to two-dimensional gel electrophoresis and mass spectroscopy. A parallel plate flow-cell model was used to study binding of a fresh isolate of S. oralis to uncoated and saliva-coated titanium surfaces. Metabolic activity was assessed using the BacLight CTC Vitality Kit and confocal scanning laser microscopy. Experiments were carried out in triplicate and the results analyzed using Student’s t-test or ANOVA. Results Secretory IgA, α-amylase and cystatins were identified as dominant proteins in the salivary pellicles. Selective adsorption of proteins was demonstrated by the enrichment of prolactin-inducible protein and absence of zinc-α2-glycoprotein relative to saliva. Adherence of S. oralis to titanium led to an up-regulation of metabolic activity in the population after 2 hours. In the presence of a salivary pellicle, this effect was enhanced and sustained over the following 22 hour period. Conclusions We have shown that adherence to smooth titanium surfaces under flow causes an up-regulation of metabolic activity in the early oral colonizer S. oralis, most likely as part of an adaptation to the biofilm mode of life. The effect was

  7. Intraspecific variation in aerobic metabolic rate of fish: relations with organ size and enzyme activity in brown trout.

    Science.gov (United States)

    Norin, Tommy; Malte, Hans

    2012-01-01

    Highly active animals require a high aerobic capacity (i.e., a high maximum metabolic rate [MMR]) to sustain such activity, and it has been speculated that a greater capacity for aerobic performance is reflected in larger organs, which serve as energy processors but are also expensive to maintain and which increase the minimal cost of living (i.e., the basal or standard metabolic rate [SMR]). In this study, we assessed the extent of intraspecific variation in metabolic rate within a group of brown trout (Salmo trutta L.) and tested whether the observed variation in residual (body-mass-corrected) SMR, MMR, and absolute aerobic scope could be explained by variations in the residual size (mass) of metabolically active internal organs. Residual SMR was found to correlate positively with residual MMR, indicating a link between these two metabolic parameters, but no relationship between organ mass and metabolic rate was found for liver, heart, spleen, intestine, or stomach. Instead, activity in the liver of two aerobic mitochondrial enzymes, cytochrome c oxidase and, to a lesser extent, citrate synthase, was found to correlate with whole-animal metabolic rate, indicating that causes for intraspecific variation in the metabolic rate of fish can be found at a lower organizational level than organ size.

  8. [Important application of intestinal transporters and metabolism enzymes on gastrointestinal disposal of active ingredients of Chinese materia medica].

    Science.gov (United States)

    Bi, Xiaolin; Du, Qiu; Di, Liuqing

    2010-02-01

    Oral drug bioavailability depends on gastrointestinal absorption, intestinal transporters and metabolism enzymes are the important factors in drug gastrointestinal absorption and they can also be induced or inhibited by the active ingredients of Chinese materia medica. This article presents important application of intestinal transporters and metabolism enzymes on gastrointestinal disposal of the active ingredients of Chinese materia medica, and points out the importance of research on transport and metabolism of the active ingredients of Chinese materia medica in Chinese extract and Chinese medicinal formulae.

  9. Metabolic activation and mutagenicity of 4 vinylic monomers (vinyl chloride, styrene, acrylonitrile, butadiene).

    Science.gov (United States)

    Duverger, M; Lambotte, M; Malvoisin, E; de Meester, C; Poncelet, F; Mercier, M

    1981-05-01

    The mutagenic activity and the metabolism of four vinylic monomers; vinyl chloride, styrene, acrylonitrile and butadiene are reviewed. Those chemicals are converted by the mixed function oxidases system of the endoplasmic reticulum into reactive intermediates which can interact with macromolecules within the cell. In order to examine the mutagenic activity of these compounds and their metabolites, different mutagenicity testing systems have been used: tests with S. typhimurium, E. coli, Schizosaccharomyces pombe, Saccharomyces cerevisiae, V79 Chinese Hamster cells, CHO cells, Drosophila melanogaster as well as evaluations of chromosome aberrations.

  10. Subglacial processes revealed by the internal structure of drumlins, Stargard drumlin field, NW Poland

    Science.gov (United States)

    Hermanowski, Piotr; Piotrowski, Jan A.; Szuman-Kalita, Izabela

    2017-04-01

    Numerous studies have provided insight into processes operating under contemporary and palaeo-ice sheets. Many of these studies concerned drumlins, landforms whose formation is essential to the understanding of subglacial soft-bedded systems. Despite the interdisciplinary efforts involving sophisticated analytical and interpretative tools the "drumlin problem" remains elusive and continues to generate much controversy. In this study the geological composition of two drumlins from the Stargard drumlin field (NW Poland) in the terminal area of a major last-glacial palaeo-ice stream was examined in three excavated trenches at macro- and microscales. In each trench, sediment description and fabric analyses were conducted, and samples collected for micromorphological, AMS (anisotropy of magnetic susceptibility) and grain size measurements. Both investigated drumlins are mainly composed of macroscopically homogeneous till with minor, max. 5 cm thick sand stringers and sparse silty inclusions. Distinct features are (1) a highly deformed, up to 18-cm thick till layer with clay- and pebble-sized clasts at the top, and (2) a continuous thin intra-till clay layer. Till macro-fabric measurements reveal a very high clustering strength and low isotropy index. AMS eigenvectors V1 vary significantly, but the dominant direction is consistent with the macrofabric measurements. Most of the observed microstructures indicate ductile deformation of the till. The overall observations suggest a shallow subglacial deformation not affecting the entire till thickness at any time intervening with ice/bed separation facilitating enhanced basal sliding. The intra-till clay layer of low hydraulic conductivity contributed to elevated pore-water pressure in the sediment causing its fluidization and deformation. Intervening thin-skinned sediment deformation and basal de-coupling resulted in fast ice flow that, coupled with material release from the ice sole and its accretion at the ice

  11. Melt-induced speed-up of Greenland ice sheet offset by efficient subglacial drainage.

    Science.gov (United States)

    Sundal, Aud Venke; Shepherd, Andrew; Nienow, Peter; Hanna, Edward; Palmer, Steven; Huybrechts, Philippe

    2011-01-27

    Fluctuations in surface melting are known to affect the speed of glaciers and ice sheets, but their impact on the Greenland ice sheet in a warming climate remains uncertain. Although some studies suggest that greater melting produces greater ice-sheet acceleration, others have identified a long-term decrease in Greenland's flow despite increased melting. Here we use satellite observations of ice motion recorded in a land-terminating sector of southwest Greenland to investigate the manner in which ice flow develops during years of markedly different melting. Although peak rates of ice speed-up are positively correlated with the degree of melting, mean summer flow rates are not, because glacier slowdown occurs, on average, when a critical run-off threshold of about 1.4 centimetres a day is exceeded. In contrast to the first half of summer, when flow is similar in all years, speed-up during the latter half is 62 ± 16 per cent less in warmer years. Consequently, in warmer years, the period of fast ice flow is three times shorter and, overall, summer ice flow is slower. This behaviour is at odds with that expected from basal lubrication alone. Instead, it mirrors that of mountain glaciers, where melt-induced acceleration of flow ceases during years of high melting once subglacial drainage becomes efficient. A model of ice-sheet flow that captures switching between cavity and channel drainage modes is consistent with the run-off threshold, fast-flow periods, and later-summer speeds we have observed. Simulations of the Greenland ice-sheet flow under climate warming scenarios should account for the dynamic evolution of subglacial drainage; a simple model of basal lubrication alone misses key aspects of the ice sheet's response to climate warming.

  12. A Unified Constitutive Model for Subglacial Till, Part I: The Disturbed State Concept

    Science.gov (United States)

    Jenson, J. W.; Desai, C. S.; Clark, P. U.; Contractor, D. N.; Sane, S. M.; Carlson, A. E.

    2006-12-01

    Classical plasticity models such as Mohr-Coulomb may not adequately represent the full range of possible motion and failure in tills underlying ice sheets. Such models assume that deformations are initially elastic, and that when a peak or failure stress level is reached the system experiences sudden failure, after which the stress remains constant and the deformations can tend to infinite magnitudes. However, theory suggests that the actual behavior of deforming materials, including granular materials such as glacial till, can involve plastic or irreversible strains almost from the beginning, in which localized zones of microcracking and "failure" can be distributed over the material element. As the loading increases, and with associated plastic and creep deformations, the distributed failure zones coalesce. When the extent of such coalesced zones reaches critical values of stresses and strains, the critical condition (failure) can occur in the till, which would cause associated movements of the ice sheet. Failure or collapse then may occur at much larger strain levels. Classical models (e.g., Mohr-Coulomb) may therefore not be able to fully and realistically characterize deformation behavior and the gradual developments of localized failures tending to the global failure and movements. We present and propose the application of the Disturbed State Concept (DSC), a unified model that incorporates the actual pre- and post-failure behavior, for characterizing the behavior of subglacial tills. In this presentation (Part I), we describe the DSC and propose its application to subglacial till. Part II (Desai et al.) describes our application of the DSC with laboratory testing, model calibration, and validations to evaluate the mechanical properties of two regionally significant Pleistocene tills.

  13. Early and current physical activity: relationship with intima-media thickness and metabolic variables in adulthood.

    Science.gov (United States)

    Lima, Manoel C S; Barbosa, Maurício F; Diniz, Tiego A; Codogno, Jamile S; Freitas Júnior, Ismael F; Fernandes, Rômulo A

    2014-01-01

    It is unclear whether early physical activity has a greater influence on intima-media thickness and metabolic variables than current physical activity. To analyze the relationship between current and early physical activity, metabolic variables, and intima-media thickness measures in adults. The sample was composed of 55 healthy subjects of both sexes (33 men and 22 women). Total body fat and trunk fat were estimated by dual-energy X-ray absorptiometry. Carotid and femoral intima-media thickness were measured using a Doppler ultrasound device. A 12-hour fasting blood sample collection was taken (fasting glucose and lipid profile). Early physical activity was assessed through face-to-face interview, and the current physical activity was assessed by pedometer (Digi-Walker Yamax, SW200), which was used for a period of seven days. Current physical activity was negatively related to total cholesterol (rho=-0.31), while early physical activity was negatively related to triglycerides (rho=-0.42), total cholesterol (rho=-0.28), very low density lipoprotein (rho=-0.44), and carotid intima-media thickness (rho=-0.50). In the multivariate model, subjects engaged in sports activities during early life had lower values of very low density lipoprotein (b=-8.74 [b95%CI=-16.1; -1.47]) and carotid intima-media thickness (b=-0.17 [95%CI: -0.28; -0.05]). Early 95%CI physical activity has a significant influence on carotid intima-media thickness, regardless of the current physical activity.

  14. Joint association of physical activity in leisure and total sitting time with metabolic syndrome amongst 15,235 Danish adults

    DEFF Research Database (Denmark)

    Petersen, Christina Bjørk; Nielsen, Asser Jon; Bauman, Adrian

    2014-01-01

    BACKGROUND: Recent studies suggest that physical inactivity as well as sitting time are associated with metabolic syndrome. Our aim was to examine joint associations of leisure time physical activity and total daily sitting time with metabolic syndrome. METHODS: Leisure time physical activity...... and total daily sitting time were assessed by self-report in 15,235 men and women in the Danish Health Examination Survey 2007-2008. Associations between leisure time physical activity, total sitting time and metabolic syndrome were investigated in logistic regression analysis. RESULTS: Adjusted odds ratios...... (OR) for metabolic syndrome were 2.14 (95% CI: 1.88-2.43) amongst participants who were inactive in leisure time compared to the most active, and 1.42 (95% CI: 1.26-1.61) amongst those who sat for ≥10h/day compared to leisure time physical activity, sitting time...

  15. Transcriptional activity of the giant barrel sponge, Xestospongia muta Holobiont: Molecular Evidence for Metabolic Interchange

    Directory of Open Access Journals (Sweden)

    Cara L Fiore

    2015-04-01

    Full Text Available Compared to our understanding of the taxonomic composition of the symbiotic microbes in marine sponges, the functional diversity of these symbionts is largely unknown. Furthermore, the application of genomic, transcriptomic, and proteomic techniques to functional questions on sponge host-symbiont interactions is in its infancy. In this study, we generated a transcriptome for the host and a metatranscriptome of its microbial symbionts for the giant barrel sponge, Xestospongia muta, from the Caribbean. In combination with a gene-specific approach, our goals were to 1 characterize genetic evidence for nitrogen cycling in X. muta, an important limiting nutrient on coral reefs 2 identify which prokaryotic symbiont lineages are metabolically active and, 3 characterize the metabolic potential of the prokaryotic community. Xestospongia muta expresses genes from multiple nitrogen transformation pathways that when combined with the abundance of this sponge, and previous data on dissolved inorganic nitrogen fluxes, shows that this sponge is an important contributor to nitrogen cycling on coral reefs. Additionally, we observed significant differences in gene expression of the archaeal amoA gene, which is involved in ammonia oxidation, between coral reef locations consistent with differences in the fluxes of dissolved inorganic nitrogen previously reported. In regards to symbiont metabolic potential, the genes in the biosynthetic pathways of several amino acids were present in the prokaryotic metatranscriptome dataset but in the host-derived transcripts only the catabolic reactions for these amino acids were present. A similar pattern was observed for the B vitamins (riboflavin, biotin, thiamin, cobalamin. These results expand our understanding of biogeochemical cycling in sponges, and the metabolic interchange highlighted here advances the field of symbiont physiology by elucidating specific metabolic pathways where there is high potential for host

  16. The relationship between metabolic presbycusis and serum paraoxonase/arylesterase activity.

    Science.gov (United States)

    Keleş, Erol; Kapusuz, Zeliha; Gürsu, Mehmet Ferit; Karlıdag, Turgut; Kaygusuz, Irfan; Bulmuş, Funda Gülcü; Yalcın, Sinasi

    2014-01-01

    To determine the presence of a relationship between metabolic presbycusis and serum paraoxonase/arylesterase activity. A total of 30 patients who had been admitted to the Ear, Nose, and Throat (ENT) Clinic of Fırat University Medical Faculty and diagnosed as metabolic presbycusis were included in the study. The control group was composed of 30 healthy volunteers. Pure tone audiometry and impedencemeter were performed on all subjects included in the study at the audiometry laboratory of the ENT clinic. The presence of a regular hearing curve, a symmetrical sensorineural hearing loss more than 25 dB with preserved speech discrimination were accepted as criteria for metabolic presbycusis. Blood samples were drawn from the patients prior to the hearing tests. The sera were separated for measurements of total cholesterol, triglyceride, high-density lipoprotein, very low-density lipoprotein, low-density lipoprotein, human serum paraoxonase and arylesterase levels, respectively. No statistically significant difference was found between the patient and the control groups in terms of age and gender. Paraoxonase, arylesterase and paraoxonase/arylesterase, high-density lipoprotein levels were found to decrease in the study group and the difference was found to be statistically significant compared to the control group (P presbycusis. Furthermore, the results of this study make us think that there could be a relationship between metabolic presbycusis and cardiovascular diseases. In this case, metabolic presbycusis may be a determining parameter in the early diagnosis of cardiovascular diseases. We consider that this study may be the pioneer for further studies conducted with larger patient numbers.

  17. Drug metabolism in human brain: high levels of cytochrome P4503A43 in brain and metabolism of anti-anxiety drug alprazolam to its active metabolite.

    Directory of Open Access Journals (Sweden)

    Varsha Agarwal

    2008-06-01

    Full Text Available Cytochrome P450 (P450 is a super-family of drug metabolizing enzymes. P450 enzymes have dual function; they can metabolize drugs to pharmacologically inactive metabolites facilitating their excretion or biotransform them to pharmacologically active metabolites which may have longer half-life than the parent drug. The variable pharmacological response to psychoactive drugs typically seen in population groups is often not accountable by considering dissimilarities in hepatic metabolism. Metabolism in brain specific nuclei may play a role in pharmacological modulation of drugs acting on the CNS and help explain some of the diverse response to these drugs seen in patient population. P450 enzymes are also present in brain where drug metabolism can take place and modify therapeutic action of drugs at the site of action. We have earlier demonstrated an intrinsic difference in the biotransformation of alprazolam (ALP in brain and liver, relatively more alpha-hydroxy alprazolam (alpha-OHALP is formed in brain as compared to liver. In the present study we show that recombinant CYP3A43 metabolizes ALP to both alpha-OHALP and 4-hydroxy alprazolam (4-OHALP while CYP3A4 metabolizes ALP predominantly to its inactive metabolite, 4-OHALP. The expression of CYP3A43 mRNA in human brain samples correlates with formation of relatively higher levels of alpha-OH ALP indicating that individuals who express higher levels of CYP3A43 in the brain would generate larger amounts of alpha-OHALP. Further, the expression of CYP3A43 was relatively higher in brain as compared to liver across different ethnic populations. Since CYP3A enzymes play a prominent role in the metabolism of drugs, the higher expression of CYP3A43 would generate metabolite profile of drugs differentially in human brain and thus impact the pharmacodynamics of psychoactive drugs at the site of action.

  18. Irregular 24-hour activity rhythms and the metabolic syndrome in older adults.

    Science.gov (United States)

    Sohail, Shahmir; Yu, Lei; Bennett, David A; Buchman, Aron S; Lim, Andrew S P

    2015-01-01

    Circadian rhythms - near 24 h intrinsic biological rhythms - modulate many aspects of human physiology and hence disruption of circadian rhythms may have an important impact on human health. Experimental work supports a potential link between irregular circadian rhythms and several key risk factors for cardiovascular disease including hypertension, obesity, diabetes and dyslipidemia, collectively termed the metabolic syndrome. While several epidemiological studies have demonstrated an association between shift-work and the components of the metabolic syndrome in working-age adults, there is a relative paucity of data concerning the impact of non-occupational circadian irregularity in older women and men. To address this question, we studied 7 days of actigraphic data from 1137 older woman and men participating in the Rush Memory and Aging Project, a community-based cohort study of the chronic conditions of aging. The regularity of activity rhythms was quantified using the nonparametric interdaily stability metric, and was related to the metabolic syndrome and its components obesity, hypertension, diabetes and dyslipidemia. More regular activity rhythms were associated with a lower odds of having the metabolic syndrome (OR = 0.69, 95% CI = 0.60-0.80, p = 5.8 × 10(-7)), being obese (OR = 0.73, 95% CI = 0.63-0.85, p = 2.5 × 10(-5)), diabetic (OR = 0.76, 95% CI = 0.65-0.90, p = 9.3 × 10(-4)), hypertensive (OR = 0.78, 95% CI = 0.66-0.91, p = 2.0 × 10(-3)) or dyslipidemic (OR = 0.82, 95% CI = 0.72-0.92, p = 1.2 × 10(-3)). These associations were independent of differences in objectively measured total daily physical activity or rest, and were not accounted for by prevalent coronary artery disease, stroke or peripheral artery disease. Moreover, more regular activity rhythms were associated with lower odds of having cardiovascular disease (OR = 0.83; 95% CI = 0.73-0.95, p = 5

  19. Transcriptional profiling unravels potential metabolic activities of the olive leaf non-glandular trichome

    Directory of Open Access Journals (Sweden)

    Konstantinos eKoudounas

    2015-08-01

    Full Text Available The olive leaf trichomes are multicellular peltate hairs densely distributed mainly at the lower leaf epidermis. Although non-glandular, they have gained much attention since they significantly contribute to abiotic and biotic stress tolerance of olive leaves. The exact mechanisms by which olive trichomes achieve these goals are not fully understood. They could act as mechanical barrier but they also accumulate high amounts of flavonoids among other secondary metabolites. However, little is currently known about the exact compounds they produce and the respective metabolic pathways. Here we present the first EST analysis from olive leaf trichomes by using 454-pyrosequencing. A total of 5,368 unigenes were identified out of 7,258 high quality reads with an average length of 262 bp. Blast search revealed that 27.5% of them had high homologies to known proteins. By using Blast2GO, 1,079 unigenes (20.1% were assigned at least one Gene Ontology (GO term. Most of the genes were involved in cellular and metabolic processes and in binding functions followed by catalytic activity. A total of 521 transcripts were mapped to 67 KEGG pathways. Olive trichomes represent a tissue of highly unique transcriptome as per the genes involved in developmental processes and the secondary metabolism. The results indicate that mature olive trichomes are trancriptionally active, mainly through the potential production of enzymes that contribute to phenolic compounds with important roles in biotic and abiotic stress responses.

  20. Blood flow to long bones indicates activity metabolism in mammals, reptiles and dinosaurs.

    Science.gov (United States)

    Seymour, Roger S; Smith, Sarah L; White, Craig R; Henderson, Donald M; Schwarz-Wings, Daniela

    2012-02-07

    The cross-sectional area of a nutrient foramen of a long bone is related to blood flow requirements of the internal bone cells that are essential for dynamic bone remodelling. Foramen area increases with body size in parallel among living mammals and non-varanid reptiles, but is significantly larger in mammals. An index of blood flow rate through the foramina is about 10 times higher in mammals than in reptiles, and even higher if differences in blood pressure are considered. The scaling of foramen size correlates well with maximum whole-body metabolic rate during exercise in mammals and reptiles, but less well with resting metabolic rate. This relates to the role of blood flow associated with bone remodelling during and following activity. Mammals and varanid lizards have much higher aerobic metabolic rates and exercise-induced bone remodelling than non-varanid reptiles. Foramen areas of 10 species of dinosaur from five taxonomic groups are generally larger than from mammals, indicating a routinely highly active and aerobic lifestyle. The simple measurement holds possibilities offers the possibility of assessing other groups of extinct and living vertebrates in relation to body size, behaviour and habitat.

  1. Physical activity does not attenuate the relationship between daily cortisol and metabolic syndrome in obese youth.

    Science.gov (United States)

    Guseman, Emily Hill; Pfeiffer, Karin A; Carlson, Joseph J; Stansbury, Kathy; Eisenmann, Joey C

    2016-01-01

    We examined the associations among daily cortisol, physical activity (MVPA) and continuous metabolic syndrome score (cMetS) in obese youth. Fifty adolescents (mean age 14.8 ± 1.9 years) were recruited from medical clinics. Daily MVPA (min/day) was assessed by accelerometry. Saliva was sampled at prescribed times: immediately upon waking; 30 min after waking; and 3, 6 and 9 h after waking. Fasting lipids, glucose, waist circumference and blood pressure were used to calculate a continuous metabolic syndrome score (cMetS). Multiple linear regression analysis was used to examine associations among variables. The mean cMetS score was 4.16 ± 4.30 and did not differ by clinic or sex. No significant relationship was found between cortisol area under the curve (cAUC) and cMetS, nor did the interaction of MVPA with cAUC significantly predict cMetS. Physical activity, cortisol, and metabolic risk were not associated in this sample of obese adolescents. Future research should examine the role of insulin sensitivity in these relationships.

  2. Colchicine to decrease NLRP3-activated inflammation and improve obesity-related metabolic dysregulation.

    Science.gov (United States)

    Demidowich, Andrew P; Davis, Angela I; Dedhia, Nicket; Yanovski, Jack A

    2016-07-01

    Obesity is a major risk-factor for the development of insulin resistance, type 2 diabetes, and cardiovascular disease. Circulating molecules associated with obesity, such as saturated fatty acids and cholesterol crystals, stimulate the innate immune system to incite a chronic inflammatory state. Studies in mouse models suggest that suppressing the obesity-induced chronic inflammatory state may prevent or reverse obesity-associated metabolic dysregulation. Human studies, however, have been far less positive, possibly because targeted interventions were too far downstream of the inciting inflammatory events. Recently, it has been shown that, within adipose tissue macrophages, assembly of a multi-protein member of the innate immune system, the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, is essential for the induction of this inflammatory state. Microtubules enable the necessary spatial arrangement of the components of the NLRP3 inflammasome in the cell, leading to its activation and propagation of the inflammatory cascade. Colchicine, a medication classically used for gout, mediates its anti-inflammatory effect by inhibiting tubulin polymerization, and has been shown to attenuate macrophage NLRP3 inflammasome arrangement and activation in vitro and in vivo. Given these findings, we hypothesize that, in at-risk individuals (those with obesity-induced inflammation and metabolic dysregulation), long-term colchicine use will lead to suppression of inflammation and thus cause improvements in insulin sensitivity and other obesity-related metabolic impairments. Published by Elsevier Ltd.

  3. Icariin Is A PPARα Activator Inducing Lipid Metabolic Gene Expression in Mice

    Directory of Open Access Journals (Sweden)

    Yuan-Fu Lu

    2014-11-01

    Full Text Available Icariin is effective in the treatment of hyperlipidemia. To understand the effect of icariin on lipid metabolism, effects of icariin on PPARα and its target genes were investigated. Mice were treated orally with icariin at doses of 0, 100, 200, and 400 mg/kg, or clofibrate (500 mg/kg for five days. Liver total RNA was isolated and the expressions of PPARα and lipid metabolism genes were examined. PPARα and its marker genes Cyp4a10 and Cyp4a14 were induced 2-4 fold by icariin, and 4-8 fold by clofibrate. The fatty acid (FA binding and co-activator proteins Fabp1, Fabp4 and Acsl1 were increased 2-fold. The mRNAs of mitochondrial FA β-oxidation enzymes (Cpt1a, Acat1, Acad1 and Hmgcs2 were increased 2-3 fold. The mRNAs of proximal β-oxidation enzymes (Acox1, Ech1, and Ehhadh were also increased by icariin and clofibrate. The expression of mRNAs for sterol regulatory element-binding factor-1 (Srebf1 and FA synthetase (Fasn were unaltered by icariin. The lipid lysis genes Lipe and Pnpla2 were increased by icariin and clofibrate. These results indicate that icariin is a novel PPARα agonist, activates lipid metabolism gene expressions in liver, which could be a basis for its lipid-lowering effects and its beneficial effects against diabetes.

  4. Blood flow to long bones indicates activity metabolism in mammals, reptiles and dinosaurs

    Science.gov (United States)

    Seymour, Roger S.; Smith, Sarah L.; White, Craig R.; Henderson, Donald M.; Schwarz-Wings, Daniela

    2012-01-01

    The cross-sectional area of a nutrient foramen of a long bone is related to blood flow requirements of the internal bone cells that are essential for dynamic bone remodelling. Foramen area increases with body size in parallel among living mammals and non-varanid reptiles, but is significantly larger in mammals. An index of blood flow rate through the foramina is about 10 times higher in mammals than in reptiles, and even higher if differences in blood pressure are considered. The scaling of foramen size correlates well with maximum whole-body metabolic rate during exercise in mammals and reptiles, but less well with resting metabolic rate. This relates to the role of blood flow associated with bone remodelling during and following activity. Mammals and varanid lizards have much higher aerobic metabolic rates and exercise-induced bone remodelling than non-varanid reptiles. Foramen areas of 10 species of dinosaur from five taxonomic groups are generally larger than from mammals, indicating a routinely highly active and aerobic lifestyle. The simple measurement holds possibilities offers the possibility of assessing other groups of extinct and living vertebrates in relation to body size, behaviour and habitat. PMID:21733896

  5. Physical activity: benefit or weakness in metabolic adaptations in a mouse model of chronic food restriction?

    Science.gov (United States)

    Méquinion, Mathieu; Caron, Emilie; Zgheib, Sara; Stievenard, Aliçia; Zizzari, Philippe; Tolle, Virginie; Cortet, Bernard; Lucas, Stéphanie; Prévot, Vincent; Chauveau, Christophe; Viltart, Odile

    2015-02-01

    In restrictive-type anorexia nervosa (AN) patients, physical activity is usually associated with food restriction, but its physiological consequences remain poorly characterized. In female mice, we evaluated the impact of voluntary physical activity with/without chronic food restriction on metabolic and endocrine parameters that might contribute to AN. In this protocol, FRW mice (i.e., food restriction with running wheel) reached a crucial point of body weight loss (especially fat mass) faster than FR mice (i.e., food restriction only). However, in contrast to FR mice, their body weight stabilized, demonstrating a protective effect of a moderate, regular physical activity. Exercise delayed meal initiation and duration. FRW mice displayed food anticipatory activity compared with FR mice, which was strongly diminished with the prolongation of the protocol. The long-term nature of the protocol enabled assessment of bone parameters similar to those observed in AN patients. Both restricted groups adapted their energy metabolism differentially in the short and long term, with less fat oxidation in FRW mice and a preferential use of glucose to compensate for the chronic energy imbalance. Finally, like restrictive AN patients, FRW mice exhibited low leptin levels, high plasma concentrations of corticosterone and ghrelin, and a disruption of the estrous cycle. In conclusion, our model suggests that physical activity has beneficial effects on the adaptation to the severe condition of food restriction despite the absence of any protective effect on lean and bone mass. Copyright © 2015 the American Physiological Society.

  6. Testosterone affects hormone-sensitive lipase (HSL) activity and lipid metabolism in the left ventricle.

    Science.gov (United States)

    Langfort, Jozef; Jagsz, Slawomir; Dobrzyn, Pawel; Brzezinska, Zofia; Klapcinska, Barbara; Galbo, Henrik; Gorski, Jan

    2010-09-03

    Fatty acids, which are the major cardiac fuel, are derived from lipid droplets stored in cardiomyocytes, among other sources. The heart expresses hormone-sensitive lipase (HSL), which regulates triglycerides (TG) breakdown, and the enzyme is under hormonal control. Evidence obtained from adipose tissue suggests that testosterone regulates HSL activity. To test whether this is also true in the heart, we measured HSL activity in the left ventricle of sedentary male rats that had been treated with testosterone supplementation or orchidectomy with or without testosterone substitution. Left ventricle HSL activity against TG was significantly elevated in intact rats supplemented with testosterone. HSL activity against both TG and diacylglyceride was reduced by orchidectomy, whereas testosterone replacement fully reversed this effect. Moreover, testosterone increased left ventricle free fatty acid levels, caused an inhibitory effect on carbohydrate metabolism in the heart, and elevated left ventricular phosphocreatine and ATP levels as compared to control rats. These data indicate that testosterone is involved in cardiac HSL activity regulation which, in turn, may affect cardiac lipid and carbohydrate metabolism. Copyright 2010 Elsevier Inc. All rights reserved.

  7. 2D-Visualization of metabolic activity with planar optical chemical sensors (optodes)

    Science.gov (United States)

    Meier, R. J.; Liebsch, G.

    2015-12-01

    Microbia plays an outstandingly important role in many hydrologic compartments, such as e.g. the benthic community in sediments, or biologically active microorganisms in the capillary fringe, in ground water, or soil. Oxygen, pH, and CO2 are key factors and indicators for microbial activity. They can be measured using optical chemical sensors. These sensors record changing fluorescence properties of specific indicator dyes. The signals can be measured in a non-contact mode, even through transparent walls, which is important for many lab-experiments. They can measure in closed (transparent) systems, without sampling or intruding into the sample. They do not consume the analytes while measuring, are fully reversible and able to measure in non-stirred solutions. These sensors can be applied as high precision fiberoptic sensors (for profiling), robust sensor spots, or as planar sensors for 2D visualization (imaging). Imaging enables to detect thousands of measurement spots at the same time and generate 2D analyte maps over a region of interest. It allows for comparing different regions within one recorded image, visualizing spatial analyte gradients, or more important to identify hot spots of metabolic activity. We present ready-to-use portable imaging systems for the analytes oxygen, pH, and CO2. They consist of a detector unit, planar sensor foils and a software for easy data recording and evaluation. Sensors foils for various analytes and measurement ranges enable visualizing metabolic activity or analyte changes in the desired range. Dynamics of metabolic activity can be detected in one shot or over long time periods. We demonstrate the potential of this analytical technique by presenting experiments on benthic disturbance-recovery dynamics in sediments and microbial degradation of organic material in the capillary fringe. We think this technique is a new tool to further understand how microbial and geochemical processes are linked in (not solely) hydrologic

  8. The Association between Physical Activity and the Metabolic Syndrome among Type 2 Diabetes Patients in Gaza Strip, Palestine.

    Science.gov (United States)

    El Bilbeisi, Abdel Hamid; Hosseini, Saeed; Djafarian, Kurosh

    2017-05-01

    Metabolic syndrome is a major health problem worldwide. Globally, the World Health Organization identified physical inactivity as the fourth leading risk factor for mortality. This study was conducted to evaluate the association between physical activities and metabolic syndrome and diabetes complications among type 2 diabetes patients in Gaza Strip, Palestine. This cross-sectional study was conducted among 1200 previously diagnosed type 2 diabetes mellitus patients (from both genders, aged 20 to 64 years) receiving care in the primary health care centers. Metabolic syndrome was defined based on the International Diabetes Federation criteria. The International Physical Activity Questionnaire was used to measure physical activity. Statistical analysis was performed using SPSS version 20. A significant inverse association was found between inactive patients and metabolic syndrome. In our study, 93.7% of inactive patients, 66.4% of active patients and 23.5% of very active patients had metabolic syndrome (OR .048 CI 95% (.03-.072)), (OR .787 CI 95% (.59-1.03)) and (OR 15.9 CI 95% (11.8-21.3)) respectively. Our results showed a significant inverse association between physical activity levels and anthropometric measurements in both gender. Moreover, a significant association was found between physical activity levels and triglycerides, HDL-cholesterol and blood pressure in both sexes (P value diabetes complications (P value physical activity are associated with increased prevalence of metabolic syndrome. Furthermore, inactive patients had a high percentage of diabetes complications among type 2 diabetes patients in Gaza Strip, Palestine.

  9. Ruptured human Achilles tendon has elevated metabolic activity up to 1 year after repair.

    Science.gov (United States)

    Eliasson, Pernilla; Couppé, Christian; Lonsdale, Markus; Svensson, René B; Neergaard, Christian; Kjær, Michael; Friberg, Lars; Magnusson, S Peter

    2016-09-01

    Following Achilles tendon rupture, running is often allowed after 6 months. However, tendon healing is slow and the metabolic status of the tendon at this point is unknown. The purpose of this study was to investigate tendon metabolism (glucose uptake) and vascularization at 3, 6 and 12 months after Achilles tendon rupture as measured using PET and power Doppler ultrasonography (PDUS). The study group comprised 23 patients with surgically repaired Achilles tendon rupture who were investigated at 3 months (n = 7), 6 months (n = 7) and 12 months (n = 9) after surgery. The triceps surae complex was loaded over 20 min of slow treadmill walking while a radioactive tracer ((18)F-FDG) was administered prior to PET. Vascularization was measured in terms of PDUS flow activity, and patient-reported outcomes were scored using the Achilles tendon rupture score (ATRS) and sports assessment (VISA-A) questionnaire. Relative glucose uptake ((18)F-FDG) was higher in repaired tendons than in intact tendons at all time-points (6, 3 and 1.6 times higher at 3, 6 and 12 months, respectively; P ≤ 0.001), and was also higher in the tendon core than in the periphery at 3 and 6 months (P ≤ 0.02), but lower at 12 months (P = 0.06). Relative glucose uptake was negatively related to ATRS at 6 months after repair (r = -0.89, P ≤ 0.01). PDUS flow activity was higher in repaired tendons than in intact tendons at 3 and 6 months (P tendon. Indeed, metabolic activity remained elevated for more than 1 year after injury despite normalized vascularization. The robust negative correlation between tendon metabolism and patient-reported outcome suggests that a high metabolic activity 6 months after the injury may be related to a poor clinical healing outcome.

  10. Peroxisome Proliferator-Activated Receptor Modulation during Metabolic Diseases and Cancers: Master and Minions

    Directory of Open Access Journals (Sweden)

    Salvatore Giovanni Vitale

    2016-01-01

    Full Text Available The prevalence of obesity and metabolic diseases (such as type 2 diabetes mellitus, dyslipidaemia, and cardiovascular diseases has increased in the last decade, in both industrialized and developing countries. This also coincided with our observation of a similar increase in the prevalence of cancers. The aetiology of these diseases is very complex and involves genetic, nutritional, and environmental factors. Much evidence indicates the central role undertaken by peroxisome proliferator-activated receptors (PPARs in the development of these disorders. Due to the fact that their ligands could become crucial in future target-therapies, PPARs have therefore become the focal point of much research. Based on this evidence, this narrative review was written with the purpose of outlining the effects of PPARs, their actions, and their prospective uses in metabolic diseases and cancers.

  11. Physical activity energy expenditure vs cardiorespiratory fitness level in impaired glucose metabolism

    DEFF Research Database (Denmark)

    Lidegaard, Lærke P; Hansen, Anne-Louise Smidt; Johansen, Nanna B

    2015-01-01

    Aim/hypothesis: Little is known about the relative roles of physical activity energy expenditure (PAEE) and cardiorespiratory fitness (CRF) as determinants of glucose regulation. The aim of this study was to examine the associations of PAEE and CRF with markers of glucose metabolism, and to test...... the hypothesis that CRF modifies the association between PAEE and glucose metabolism. Methods: We analysed cross-sectional data from 755 adults from the Danish ADDITION-PRO study. On the basis of OGTT results, participants without known diabetes were classified as having normal glucose tolerance, isolated...... impaired fasting glycaemia (i-IFG), isolated impaired glucose tolerance (i-IGT), combined IFG + IGT or screen-detected diabetes mellitus. Markers of insulin sensitivity and beta cell function were determined. PAEE was measured using a combined heart rate and movement sensor. CRF (maximal oxygen uptake...

  12. Peroxisome Proliferator-Activated Receptor Modulation during Metabolic Diseases and Cancers: Master and Minions

    Science.gov (United States)

    Nigro, Angela; La Rosa, Valentina Lucia; Rossetti, Paola; Rapisarda, Agnese Maria Chiara; Condorelli, Rosita Angela; Corrado, Francesco; Buscema, Massimo

    2016-01-01

    The prevalence of obesity and metabolic diseases (such as type 2 diabetes mellitus, dyslipidaemia, and cardiovascular diseases) has increased in the last decade, in both industrialized and developing countries. This also coincided with our observation of a similar increase in the prevalence of cancers. The aetiology of these diseases is very complex and involves genetic, nutritional, and environmental factors. Much evidence indicates the central role undertaken by peroxisome proliferator-activated receptors (PPARs) in the development of these disorders. Due to the fact that their ligands could become crucial in future target-therapies, PPARs have therefore become the focal point of much research. Based on this evidence, this narrative review was written with the purpose of outlining the effects of PPARs, their actions, and their prospective uses in metabolic diseases and cancers. PMID:28115924

  13. Physical activity, sedentary behavior, and the metabolic syndrome in minority youth.

    Science.gov (United States)

    Hsu, Ya-Wen; Belcher, Britni R; Ventura, Emily E; Byrd-Williams, Courtney E; Weigensberg, Marc J; Davis, Jaimie N; McClain, Arianna D; Goran, Michael I; Spruijt-Metz, Donna

    2011-12-01

    This study aimed to determine the associations among physical activity, sedentary behavior, and the metabolic syndrome (MetS) in Latino and African American youth using both subjective and objective measures of activity levels. Cross-sectional data from 105 participants from three pediatric obesity studies that share a core set of methods and measures (Latino 74%, female 75%, mean age = 13 ± 3 yr) were used. Measures included moderate-to-vigorous physical activity and sedentary behavior by accelerometry and 3-Day Physical Activity Recall (3DPAR), fat and lean tissue mass by BodPod™, fasting glucose, lipids, blood pressure, and waist circumference. Associations between physical activity, sedentary behavior, and MetS were examined using ANCOVA, Pearson correlations, partial correlations, and logistic regressions with adjustments for age, sex, ethnicity, fat and lean mass, and pubertal Tanner stage. Accelerometry data showed that greater time engaging in moderate-to-vigorous physical activity was related to lower odds of the MetS (odds ratio = 0.49, 95% confidence interval = 0.25-0.98), independent of sedentary behavior and covariates, and inversely correlated with fasting glucose (r = -0.21, P = 0.03) and systolic blood pressure (r = -0.25, P = 0.01), adjusting for covariates. Data from the 3DPAR showed that higher levels of sedentary behavior were related to higher odds of the MetS (odds ratio = 4.44, 95% confidence interval = 1.33-14.79), independent of moderate-to-vigorous physical activity and covariates, negatively correlated with HDL-cholesterol (r = -0.21, P = 0.04) and positively correlated systolic blood pressure (r = 0.26, P = 0.009), adjusting for covariates. Future interventions aiming to improve metabolic health in youth should target both the promotion of physical activity and the reduction of sedentary behavior. Subjective and objective measures should be used in conjunction to better capture activity behaviors.

  14. Phagocytic activity is impaired in type 2 diabetes mellitus and increases after metabolic improvement.

    Directory of Open Access Journals (Sweden)

    Albert Lecube

    Full Text Available OBJECTIVE: 1 To evaluate whether peripheral blood mononuclear cells (PBMCs from type 2 diabetic patients present an impairment of phagocytic activity; 2 To determine whether the eventual impairment in phagocytic activity is related to glycemic control and can be reversed by improving blood glucose levels. METHODS: 21 type 2 diabetic patients and 21 healthy volunteers were prospectively recruited for a case-control study. In addition, those patients in whom HbA1c was higher than 8% (n = 12 were hospitalized in order to complete a 5-day intensification treatment of blood glucose. Phagocytic activity was assessed by using a modified flow cytometry procedure developed in our laboratory based on DNA/RNA viable staining to discriminate erythrocytes and debris. This method is simple, highly sensitive and reproducible and it takes advantage of classic methods that are widely used in flow cytometry. RESULTS: Type 2 diabetic patients showed a lower percentage of activated macrophages in comparison with non-diabetic subjects (54.00±18.93 vs 68.53±12.77%; p = 0.006 Significant negative correlations between phagocytic activity and fasting glucose (r = -0.619, p = 0.004 and HbA1c (r = -0.506, p = 0.019 were detected. In addition, multiple linear regression analyses showed that either fasting plasma glucose or HbA1c were independently associated with phagocytic activity. Furthermore, in the subset of patients who underwent metabolic optimization a significant increase in phagocytic activity was observed (p = 0.029. CONCLUSIONS: Glycemic control is related to phagocytic activity in type 2 diabetes. Our results suggest that improvement in phagocytic activity can be added to the beneficial effects of metabolic optimization.

  15. Association between physical activity and metabolic syndrome: a cross sectional survey in adolescents in Ho Chi Minh City, Vietnam

    Directory of Open Access Journals (Sweden)

    van der Ploeg Hidde P

    2010-03-01

    Full Text Available Abstract Background The emerging epidemic of overweight/obesity in adolescents in Ho Chi Minh City, Vietnam underlines the importance of studying the metabolic syndrome in Vietnamese adolescents who are becoming progressively more inactive. No study in Vietnam has examined the association of metabolic syndrome with moderate to vigorous physical activity (PA levels among adolescents. We aimed to examine this association in a sample of urban adolescents from Ho Chi Minh City. Methods A cross-sectional assessment was conducted in 2007 on a representative sample of 693 high-school students from urban districts in Ho Chi Minh City. Metabolic syndrome was defined according to the International Diabetes Federation criteria and physical activity was measured with Actigraph accelerometers. The association between physical activity and metabolic syndrome was assessed by using multiple logistic regression models. Results Overall 4.6% of the adolescents and 11.8% of the overweight/obese adolescents had metabolic syndrome. Elevated BP was the most common individual component of the metabolic syndrome (21.5%, followed by hypertriglyceridemia (11.1%. After adjusting for other study factors, the odds of metabolic syndrome among youth in the lowest physical activity group (103 minutes/day (AOR = 5.3, 95% CI: 1.5, 19.1. Metabolic syndrome was also positively associated with socioeconomic status (AOR = 9.4, 95% CI: 2.1, 42.4. Conclusions A more physically active lifestyle appears to be associated with a lower odds of metabolic syndrome in Vietnamese adolescents. Socio-economic status should be taken into account when planning interventions to prevent adolescent metabolic syndrome.

  16. Chronic inhibition of 11 β -hydroxysteroid dehydrogenase type 1 activity decreases hypertension, insulin resistance, and hypertriglyceridemia in metabolic syndrome.

    Science.gov (United States)

    Schnackenberg, Christine G; Costell, Melissa H; Krosky, Daniel J; Cui, Jianqi; Wu, Charlene W; Hong, Victor S; Harpel, Mark R; Willette, Robert N; Yue, Tian-Li

    2013-01-01

    Metabolic syndrome is a constellation of risk factors including hypertension, dyslipidemia, insulin resistance, and obesity that promote the development of cardiovascular disease. Metabolic syndrome has been associated with changes in the secretion or metabolism of glucocorticoids, which have important functions in adipose, liver, kidney, and vasculature. Tissue concentrations of the active glucocorticoid cortisol are controlled by the conversion of cortisone to cortisol by 11 β -hydroxysteroid dehydrogenase type 1 (11 β -HSD1). Because of the various cardiovascular and metabolic activities of glucocorticoids, we tested the hypothesis that 11 β -HSD1 is a common mechanism in the hypertension, dyslipidemia, and insulin resistance in metabolic syndrome. In obese and lean SHR/NDmcr-cp (SHR-cp), cardiovascular, metabolic, and renal functions were measured before and during four weeks of administration of vehicle or compound 11 (10 mg/kg/d), a selective inhibitor of 11 β -HSD1. Compound 11 significantly decreased 11 β -HSD1 activity in adipose tissue and liver of SHR-cp. In obese SHR-cp, compound 11 significantly decreased mean arterial pressure, glucose intolerance, insulin resistance, hypertriglyceridemia, and plasma renin activity with no effect on heart rate, body weight gain, or microalbuminuria. These results suggest that 11 β -HSD1 activity in liver and adipose tissue is a common mediator of hypertension, hypertriglyceridemia, glucose intolerance, and insulin resistance in metabolic syndrome.

  17. Chronic Inhibition of 11β-Hydroxysteroid Dehydrogenase Type 1 Activity Decreases Hypertension, Insulin Resistance, and Hypertriglyceridemia in Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Christine G. Schnackenberg

    2013-01-01

    Full Text Available Metabolic syndrome is a constellation of risk factors including hypertension, dyslipidemia, insulin resistance, and obesity that promote the development of cardiovascular disease. Metabolic syndrome has been associated with changes in the secretion or metabolism of glucocorticoids, which have important functions in adipose, liver, kidney, and vasculature. Tissue concentrations of the active glucocorticoid cortisol are controlled by the conversion of cortisone to cortisol by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1. Because of the various cardiovascular and metabolic activities of glucocorticoids, we tested the hypothesis that 11β-HSD1 is a common mechanism in the hypertension, dyslipidemia, and insulin resistance in metabolic syndrome. In obese and lean SHR/NDmcr-cp (SHR-cp, cardiovascular, metabolic, and renal functions were measured before and during four weeks of administration of vehicle or compound 11 (10 mg/kg/d, a selective inhibitor of 11β-HSD1. Compound 11 significantly decreased 11β-HSD1 activity in adipose tissue and liver of SHR-cp. In obese SHR-cp, compound 11 significantly decreased mean arterial pressure, glucose intolerance, insulin resistance, hypertriglyceridemia, and plasma renin activity with no effect on heart rate, body weight gain, or microalbuminuria. These results suggest that 11β-HSD1 activity in liver and adipose tissue is a common mediator of hypertension, hypertriglyceridemia, glucose intolerance, and insulin resistance in metabolic syndrome.

  18. Dietary electrolyte balance affects growth performance, amylase activity and metabolic response in the meagre (Argyrosomus regius).

    Science.gov (United States)

    Magnoni, Leonardo J; Salas-Leiton, Emilio; Peixoto, Maria-João; Pereira, Luis; Silva-Brito, Francisca; Fontinha, Filipa; Gonçalves, José F M; Wilson, Jonathan M; Schrama, Johan W; Ozório, Rodrigo O A

    2017-09-01

    Dietary ion content is known to alter the acid-base balance in freshwater fish. The current study investigated the metabolic impact of acid-base disturbances produced by differences in dietary electrolyte balance (DEB) in the meagre (Argyrosomus regius), an euryhaline species. Changes in fish performance, gastric chyme characteristics, pH and ion concentrations in the bloodstream, digestive enzyme activities and metabolic rates were analyzed in meagre fed ad libitum two experimental diets (DEB 200 or DEB 700mEq/kg) differing in the Na2CO3 content for 69days. Fish fed the DEB 200 diet had 60-66% better growth performance than the DEB 700 group. Meagre consuming the DEB 200 diet were 90-96% more efficient than fish fed the DEB 700 diet at allocating energy from feed into somatic growth. The pH values in blood were significantly lower in the DEB 700 group 2h after feeding when compared to DEB 200, indicating that acid-base balance in meagre was affected by electrolyte balance in diet. Osmolality, and Na+ and K+ concentrations in plasma did not vary with the dietary treatment. Gastric chyme in the DEB 700 group had higher pH values, dry matter, protein and energy contents, but lower lipid content than in the DEB 200 group. Twenty-four hours after feeding, amylase activity was higher in the gastrointestinal tract of DEB 700 group when compared to the DEB 200 group. DEB 700 group had lower routine metabolic (RMR) and standard metabolic (SMR) rates, indicating a decrease in maintenance energy expenditure 48h after feeding the alkaline diet. The current study demonstrates that feeding meagre with an alkaline diet not only causes acid-base imbalance, but also negatively affects digestion and possibly nutrient assimilation, resulting in decreased growth performance. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Detrital zircons - the unique source of information on tectonics, paleogeography and denudation processes of East Antarctica (subglacial challenge)

    Science.gov (United States)

    Belyatsky, Boris; Leitchenkov, German; Rodionov, Nickolay; Antonov, Anton; Sergeev, Sergey; Savva, Helen

    2010-05-01

    Vast (about 7 billions km2) almost wholly (98%) covered with ice continental mass of East Antarctica is the central fragment of ancient supercontinents of Rodinia and Gondwana. Any information on its geologic structure is of the greatest importance for solving the problems of formation and amalgamation of lithosphere of ancient continents, processes of intraplate activity, denudation and peneplanation of the earth crust and for geodynamic reconstruction. Geologic structure of central part of the East Antarctica is still absolutely unknown due to the thick (up to 4000 m) ice cover, which is the obstacle even for modern drilling technology to sample directly the underlying rocks. The main goal of the study has been to make an attempt in fill up the hiatus in geologic knowledge on the origin of subglacial continental crust of the Antarctica. We studied detrital zircons from sedimentary and metasedimentary rocks outcropped in Prince-Charles Mts (PCM, East Antarctica). Rock specimens were sampled from the Permian-Triassic sedimentary succession outcropped along the Beaver Lake coast (sandstones and siltstones) and from moraine of the Fisher Massive (metasandstone) and Meridith Massive (sandstone). A lump of zircons which are characterized by different grain morphology from well-rounded to poorly-rounded has been extracted from rock specimens for isotopic studies and dating. The age determinations of 302 zircons from 6 specimens were conducted using secondary ion-microprobe SHRIMP-II and laser-ablation ICP-MS. The age of zircons ranges from 500 to 3200 Ma. Isotopic analysis and probability distribution diagrams for zircon populations show heterogeneity of provenance. Zircons of 500 Ma old are proposed to come from the eastern flank of Lambert Glacier and/or from central Antarctica; 900-1100 Ma old - from Proterozoic Mobile Belt (central-northern PCM); while 2400-3200 Ma old - from granite-greenstone terrain (southern PCM). Additionally, 21 trace elements and isotopic

  20. The Relationship Between Physical Activity and the Metabolic Syndrome Score in Children

    Science.gov (United States)

    McKune, Andrew J.; Brophy, Patricia; Geyer, Gabriel; Hickner, Robert C.

    2015-01-01

    The relationship between physical activity levels and the metabolic syndrome (MetSyn) score was examined in 72 boys and girls (9.5 ± 1.2 years). A fasting blood draw was obtained; waist circumference and blood pressure measured, and an accelerometer was worn for 5 days. Established cut points were used to estimate time spent in moderate, vigorous, moderate-to-vigorous (MVPA), and total physical activity. A continuous MetSyn score was created from blood pressure, waist circumference, high-density-lipoprotein, triglyceride, and glucose values. Regression analysis was used to examine the relationship between physical activity levels, the MetSyn score, and its related components. Logistic regression was used to examine the association between meeting physical activity recommendations, the MetSyn score, and its related components. All analyses were controlled for body mass index group, age, sex, and race. Time spent in different physical activity levels or meeting physical activity recommendations (OR: 0.87, 95%CI: 0.69-1.09) was not related with the MetSyn score after controlling for potential confounders (p>0.05). Moderate physical activity, MVPA, and meeting physical activity recommendations were related to a lower diastolic blood pressure (p0.05). While physical activity participation was not related with the MetSyn, lower diastolic blood pressure values were related to higher physical activity levels. PMID:25902555

  1. The Relationship Between Physical Activity and the Metabolic Syndrome Score in Children.

    Science.gov (United States)

    DuBose, Katrina D; McKune, Andrew J; Brophy, Patricia; Geyer, Gabriel; Hickner, Robert C

    2015-08-01

    The relationship between physical activity levels and the metabolic syndrome (MetSyn) score was examined in 72 boys and girls (9.5 ± 1.2 years). A fasting blood draw was obtained; waist circumference and blood pressure measured, and an accelerometer was worn for 5 days. Established cut points were used to estimate time spent in moderate, vigorous, moderate-to-vigorous (MVPA), and total physical activity. A continuous MetSyn score was created from blood pressure, waist circumference, high-density-lipoprotein, triglyceride, and glucose values. Regression analysis was used to examine the relationship between physical activity levels, the MetSyn score, and its related components. Logistic regression was used to examine the association between meeting physical activity recommendations, the MetSyn score, and its related components. All analyses were controlled for body mass index group, age, sex, and race. Time spent in different physical activity levels or meeting physical activity recommendations (OR: 0.87, 95%CI: 0.69-1.09) was not related with the MetSyn score after controlling for potential confounders (p > .05). Moderate physical activity, MVPA, and meeting physical activity recommendations were related to a lower diastolic blood pressure (p .05). While physical activity participation was not related with the MetSyn, lower diastolic blood pressure values were related to higher physical activity levels.

  2. Non-Invasive Microbial Metabolic Activity Sensing at Single Cell Level by Perfusion of Calcein Acetoxymethyl Ester.

    Directory of Open Access Journals (Sweden)

    Christina E M Krämer

    Full Text Available Phase contrast microscopy cannot give sufficient information on bacterial metabolic activity, or if a cell is dead, it has the fate to die or it is in a viable but non-growing state. Thus, a reliable sensing of the metabolic activity helps to distinguish different categories of viability. We present a non-invasive instantaneous sensing method using a fluorogenic substrate for online monitoring of esterase activity and calcein efflux changes in growing wild type bacteria. The fluorescent conversion product of calcein acetoxymethyl ester (CAM and its efflux indicates the metabolic activity of cells grown under different conditions at real-time. The dynamic conversion of CAM and the active efflux of fluorescent calcein were analyzed by combining microfluidic single cell cultivation technology and fluorescence time lapse microscopy. Thus, an instantaneous and non-invasive sensing method for apparent esterase activity was created without the requirement of genetic modification or harmful procedures. The metabolic activity sensing method consisting of esterase activity and calcein secretion was demonstrated in two applications. Firstly, growing colonies of our model organism Corynebacterium glutamicum were confronted with intermittent nutrient starvation by interrupting the supply of iron and carbon, respectively. Secondly, bacteria were exposed for one hour to fatal concentrations of antibiotics. Bacteria could be distinguished in growing and non-growing cells with metabolic activity as well as non-growing and non-fluorescent cells with no detectable esterase activity. Microfluidic single cell cultivation combined with high temporal resolution time-lapse microscopy facilitated monitoring metabolic activity of stressed cells and analyzing their descendants in the subsequent recovery phase. Results clearly show that the combination of CAM with a sampling free microfluidic approach is a powerful tool to gain insights in the metabolic activity of growing

  3. Glucosylceramide and glucosylsphingosine metabolism in cultured fibroblasts deficient in acid beta-glucosidase activity.

    Science.gov (United States)

    Sasagasako, N; Kobayashi, T; Yamaguchi, Y; Shinnoh, N; Goto, I

    1994-01-01

    The metabolism of glucosylceramide (GlcCer) and glucosylsphingosine (GlcSph) was studied using cultured fibroblasts deficient in acid beta-glucosidase activity. In fibroblasts from patients with Gaucher's disease, in vitro beta-glucosidase activities were 2.7-11.7% and 4.8-13.6% of control values when 4-methylumbelliferyl beta-D-glucoside and GlcSph were used as substrates, respectively. In spite of the enzyme deficiency, GlcCer and GlcSph, the natural substrates of the deficient enzyme, did not accumulate in the cells. When normal fibroblasts were incubated with conduritol B epoxide (CBE), a specific inhibitor of acid beta-glucosidase, the in vitro enzyme activities decreased dose-dependently (2.2-2.4% of control values at 50 microM CBE), and GlcCer and GlcSph accumulated in the cells at concentrations of CBE higher than 50 microM. To investigate the intracellular metabolism of GlcCer and GlcSph, either radioactive GlcCer or GlcSph was loaded onto cultured fibroblasts. In fibroblasts treated with a high dose of CBE (1 mM), the degradation of GlcCer and GlcSph was retarded (5-21% on day 7; normal range, 81-99%), while in fibroblasts from patients with Gaucher's disease, both the pattern and rate of the degradation of the lipids (83-97% on day 7) were almost the same as those seen in the control cells. These results indicate that in Gaucher's disease fibroblasts the intracellular metabolism of GlcCer and GlcSph is normal in spite of the deficiency in beta-glucosidase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Metabolic and behavioral responses to high-fat feeding in mice selectively bred for high wheel-running activity

    NARCIS (Netherlands)

    Vaanholt, L. M.; Jonas, I.; Doornbos, M.; Schubert, K. A.; Nyakas, C.; Garland, T.; Visser, G. H.; van Dijk, G.; Garland Jr., T.

    2008-01-01

    Objective: Increased dietary fat intake is a precipitating factor for the development of obesity and associated metabolic disturbances. Physically active individuals generally have a reduced risk of developing these unhealthy states, but the underlying mechanisms are poorly understood. In the

  5. Metabolic profile in two physically active Inuit groups consuming either a western or a traditional Inuit diet

    DEFF Research Database (Denmark)

    Andersen, Thor Munch; Olsen, David B; Søndergaard, Hans

    2012-01-01

    To evaluate the effect of regular physical activity on metabolic risk factors and blood pressure in Inuit with high BMI consuming a western diet (high amount of saturated fatty acids and carbohydrates with a high glycemic index)....

  6. Zanthoxylum alkylamides activate phosphorylated AMPK and ameliorate glycolipid metabolism in the streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Ren, Tingyuan; Zhu, Yuping; Kan, Jianquan

    2017-01-01

    This study aimed to evaluate the effects of Zanthoxylum alkylamides on the glycolipid metabolism of rats with streptozotocin (STZ)-induced diabetes. Diabetic rats were given daily oral treatments of 2, 4, or 8 mg/kg bw alkylamides for 28 days. Alkylamides significantly decreased fasting blood glucose and fructosamine content, as well as relieved organ enlargement caused by diabetes. The serum and liver triglyceride, malondialdehyde, and free fatty-acid contents of rats with STZ-induced diabetes were significantly reduced. Total cholesterol in the liver also significantly decreased. Quantitative polymerase chain reaction (Q-PCR) and Western blot detected insignificantly increased (P > 0.05) mRNA expression levels of adenosine monophosphate-activated protein kinase (AMPK) in the skeletal muscle of diabetic rats. However, AMPK and p-AMPK (Thr172) protein expression levels significantly increased. The mRNA and protein expression levels of silencing information regulator 1 significantly increased. The mRNA expression levels of acetyl-CoA-carboxylase (ACC) and protein p-ACC (Ser79) also increased. The mRNA and protein expression levels of glucose transporter type 4 (GLUT4) were significantly upregulated in the skeletal muscle cell membranes of diabetic rats. Results indicated that alkylamides activated the AMPK-signaling pathway. Thus, inhibiting ACC activity reduced fatty-acid synthesis. The rapid translocation of GLUT4 mediated increased glucose transport rate and reduced blood glucose. Therefore, alkylamides can ameliorate glucose and lipid metabolism disorders in diabetic rats by activating the AMPK pathway.

  7. Metabolic Basis for Thyroid Hormone Liver Preconditioning: Upregulation of AMP-Activated Protein Kinase Signaling

    Directory of Open Access Journals (Sweden)

    Luis A. Videla

    2012-01-01

    Full Text Available The liver is a major organ responsible for most functions of cellular metabolism and a mediator between dietary and endogenous sources of energy for extrahepatic tissues. In this context, adenosine-monophosphate- (AMP- activated protein kinase (AMPK constitutes an intrahepatic energy sensor regulating physiological energy dynamics by limiting anabolism and stimulating catabolism, thus increasing ATP availability. This is achieved by mechanisms involving direct allosteric activation and reversible phosphorylation of AMPK, in response to signals such as energy status, serum insulin/glucagon ratio, nutritional stresses, pharmacological and natural compounds, and oxidative stress status. Reactive oxygen species (ROS lead to cellular AMPK activation and downstream signaling under several experimental conditions. Thyroid hormone (L-3,3′,5-triiodothyronine, T3 administration, a condition that enhances liver ROS generation, triggers the redox upregulation of cytoprotective proteins affording preconditioning against ischemia-reperfusion (IR liver injury. Data discussed in this work suggest that T3-induced liver activation of AMPK may be of importance in the promotion of metabolic processes favouring energy supply for the induction and operation of preconditioning mechanisms. These include antioxidant, antiapoptotic, and anti-inflammatory mechanisms, repair or resynthesis of altered biomolecules, induction of the homeostatic acute-phase response, and stimulation of liver cell proliferation, which are required to cope with the damaging processes set in by IR.

  8. A Protein Scaffold Coordinates SRC-Mediated JNK Activation in Response to Metabolic Stress.

    Science.gov (United States)

    Kant, Shashi; Standen, Claire L; Morel, Caroline; Jung, Dae Young; Kim, Jason K; Swat, Wojciech; Flavell, Richard A; Davis, Roger J

    2017-09-19

    Obesity is a major risk factor for the development of metabolic syndrome and type 2 diabetes. How obesity contributes to metabolic syndrome is unclear. Free fatty acid (FFA) activation of a non-receptor tyrosine kinase (SRC)-dependent cJun NH 2 -terminal kinase (JNK) signaling pathway is implicated in this process. However, the mechanism that mediates SRC-dependent JNK activation is unclear. Here, we identify a role for the scaffold protein JIP1 in SRC-dependent JNK activation. SRC phosphorylation of JIP1 creates phosphotyrosine interaction motifs that bind the SH2 domains of SRC and the guanine nucleotide exchange factor VAV. These interactions are required for SRC-induced activation of VAV and the subsequent engagement of a JIP1-tethered JNK signaling module. The JIP1 scaffold protein, therefore, plays a dual role in FFA signaling by coordinating upstream SRC functions together with downstream effector signaling by the JNK pathway. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  9. A damping circadian clock drives weak oscillations in metabolism and locomotor activity of aphids (Acyrthosiphon pisum).

    Science.gov (United States)

    Beer, Katharina; Joschinski, Jens; Arrazola Sastre, Alazne; Krauss, Jochen; Helfrich-Förster, Charlotte

    2017-11-02

    Timing seasonal events, like reproduction or diapause, is crucial for the survival of many species. Global change causes phenologies worldwide to shift, which requires a mechanistic explanation of seasonal time measurement. Day length (photoperiod) is a reliable indicator of winter arrival, but it remains unclear how exactly species measure day length. A reference for time of day could be provided by a circadian clock, by an hourglass clock, or, as some newer models suggest, by a damped circadian clock. However, damping of clock outputs has so far been rarely observed. To study putative clock outputs of Acyrthosiphon pisum aphids, we raised individual nymphs on coloured artificial diet, and measured rhythms in metabolic activity in light-dark illumination cycles of 16:08 hours (LD) and constant conditions (DD). In addition, we kept individuals in a novel monitoring setup and measured locomotor activity. We found that A. pisum is day-active in LD, potentially with a bimodal distribution. In constant darkness rhythmicity of locomotor behaviour persisted in some individuals, but patterns were mostly complex with several predominant periods. Metabolic activity, on the other hand, damped quickly. A damped circadian clock, potentially driven by multiple oscillator populations, is the most likely explanation of our results.

  10. Requirement of AMPK activation for neuronal metabolic-enhancing effects of antidepressant paroxetine.

    Science.gov (United States)

    Jeong, Jihyeon; Park, Minsun; Yoon, Jeong Seon; Kim, Hyunjeong; Lee, Su Kyoung; Lee, Eun; Namkoong, Kee; Kim, Eosu

    2015-05-06

    Reduced glucose metabolism has been implicated as a pathophysiology of depressive disorder. Normalization of such impaired neurometabolism has been related to the therapeutic actions of antidepressant medication. However, the molecular mechanism underlying the neurometabolic actions of antidepressants has not been fully understood. Given that AMP-activated protein kinase (AMPK) is a master switch for energy homeostasis, we aimed to determine whether selective serotonin reuptake inhibitor paroxetine enhances energy metabolism by activating AMPK in neuroblastoma cells. We found that paroxetine dose dependently increased mitochondrial biogenesis, which involves the AMPK-peroxisome proliferator-activated receptor-γ coactivator-1α pathway. In addition, paroxetine-induced AMPK activation increases glucose uptake and ATP production. These neurometabolic effects of paroxetine were suppressed by cotreatment with compound C (CC), an AMPK inhibitor. These findings suggest a possibility that modulation of the AMPK pathway might be a previously unrecognized mechanism underlying the neurometabolic action of antidepressants. Further study is warranted to examine the region-specific and time-specific effects of AMPK modulation by antidepressants on mood-related behaviors.

  11. Disposition, Metabolism and Histone Deacetylase and Acetyltransferase Inhibition Activity of Tetrahydrocurcumin and Other Curcuminoids

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    Júlia T. Novaes

    2017-10-01

    Full Text Available Tetrahydrocurcumin (THC, curcumin and calebin-A are curcuminoids found in turmeric (Curcuma longa. Curcuminoids have been established to have a variety of pharmacological activities and are used as natural health supplements. The purpose of this study was to identify the metabolism, excretion, antioxidant, anti-inflammatory and anticancer properties of these curcuminoids and to determine disposition of THC in rats after oral administration. We developed a UHPLC–MS/MS assay for THC in rat serum and urine. THC shows multiple redistribution phases with corresponding increases in urinary excretion rate. In-vitro antioxidant activity, histone deacetylase (HDAC activity, histone acetyltransferase (HAT activity and anti-inflammatory inhibitory activity were examined using commercial assay kits. Anticancer activity was determined in Sup-T1 lymphoma cells. Our results indicate THC was poorly absorbed after oral administration and primarily excreted via non-renal routes. All curcuminoids exhibited multiple pharmacological effects in vitro, including potent antioxidant activity as well as inhibition of CYP2C9, CYP3A4 and lipoxygenase activity without affecting the release of TNF-α. Unlike curcumin and calebin-A, THC did not inhibit HDAC1 and PCAF and displayed a weaker growth inhibition activity against Sup-T1 cells. We show evidence for the first time that curcumin and calebin-A inhibit HAT and PCAF, possibly through a Michael-addition mechanism.

  12. Aerobic glycolysis during brain activation: adrenergic regulation and influence of norepinephrine on astrocytic metabolism.

    Science.gov (United States)

    Dienel, Gerald A; Cruz, Nancy F

    2016-07-01

    Aerobic glycolysis occurs during brain activation and is characterized by preferential up-regulation of glucose utilization compared with oxygen consumption even though oxygen level and delivery are adequate. Aerobic glycolysis is a widespread phenomenon that underlies energetics of diverse brain activities, such as alerting, sensory processing, cognition, memory, and pathophysiological conditions, but specific cellular functions fulfilled by aerobic glycolysis are poorly understood. Evaluation of evidence derived from different disciplines reveals that aerobic glycolysis is a complex, regulated phenomenon that is prevented by propranolol, a non-specific β-adrenoceptor antagonist. The metabolic pathways that contribute to excess utilization of glucose compared with oxygen include glycolysis, the pentose phosphate shunt pathway, the malate-aspartate shuttle, and astrocytic glycogen turnover. Increased lactate production by unidentified cells, and lactate dispersal from activated cells and lactate release from the brain, both facilitated by astrocytes, are major factors underlying aerobic glycolysis in subjects with low blood lactate levels. Astrocyte-neuron lactate shuttling with local oxidation is minor. Blockade of aerobic glycolysis by propranolol implicates adrenergic regulatory processes including adrenal release of epinephrine, signaling to brain via the vagus nerve, and increased norepinephrine release from the locus coeruleus. Norepinephrine has a powerful influence on astrocytic metabolism and glycogen turnover that can stimulate carbohydrate utilization more than oxygen consumption, whereas β-receptor blockade 're-balances' the stoichiometry of oxygen-glucose or -carbohydrate metabolism by suppressing glucose and glycogen utilization more than oxygen consumption. This conceptual framework may be helpful for design of future studies to elucidate functional roles of preferential non-oxidative glucose utilization and glycogen turnover during brain

  13. Activation of AMP-Activated Protein Kinase and Stimulation of Energy Metabolism by Acetic Acid in L6 Myotube Cells.

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    Hitomi Maruta

    Full Text Available Previously, we found that orally administered acetic acid decreased lipogenesis in the liver and suppressed lipid accumulation in adipose tissue of Otsuka Long-Evans Tokushima Fatty rats, which exhibit hyperglycemic obesity with hyperinsulinemia and insulin resistance. Administered acetic acid led to increased phosphorylation of AMP-activated protein kinase (AMPK in both liver and skeletal muscle cells, and increased transcripts of myoglobin and glucose transporter 4 (GLUT4 genes in skeletal muscle of the rats. It was suggested that acetic acid improved the lipid metabolism in skeletal muscles. In this study, we examined the activation of AMPK and the stimulation of GLUT4 and myoglobin expression by acetic acid in skeletal muscle cells to clarify the physiological function of acetic acid in skeletal muscle cells. Acetic acid added to culture medium was taken up rapidly by L6 cells, and AMPK was phosphorylated upon treatment with acetic acid. We observed increased gene and protein expression of GLUT4 and myoglobin. Uptake of glucose and fatty acids by L6 cells were increased, while triglyceride accumulation was lower in treated cells compared to untreated cells. Furthermore, treated cells also showed increased gene and protein expression of myocyte enhancer factor 2A (MEF2A, which is a well-known transcription factor involved in the expression of myoglobin and GLUT4 genes. These results indicate that acetic acid enhances glucose uptake and fatty acid metabolism through the activation of AMPK, and increases expression of GLUT4 and myoglobin.

  14. Activation of AMP-Activated Protein Kinase and Stimulation of Energy Metabolism by Acetic Acid in L6 Myotube Cells.

    Science.gov (United States)

    Maruta, Hitomi; Yoshimura, Yukihiro; Araki, Aya; Kimoto, Masumi; Takahashi, Yoshitaka; Yamashita, Hiromi

    2016-01-01

    Previously, we found that orally administered acetic acid decreased lipogenesis in the liver and suppressed lipid accumulation in adipose tissue of Otsuka Long-Evans Tokushima Fatty rats, which exhibit hyperglycemic obesity with hyperinsulinemia and insulin resistance. Administered acetic acid led to increased phosphorylation of AMP-activated protein kinase (AMPK) in both liver and skeletal muscle cells, and increased transcripts of myoglobin and glucose transporter 4 (GLUT4) genes in skeletal muscle of the rats. It was suggested that acetic acid improved the lipid metabolism in skeletal muscles. In this study, we examined the activation of AMPK and the stimulation of GLUT4 and myoglobin expression by acetic acid in skeletal muscle cells to clarify the physiological function of acetic acid in skeletal muscle cells. Acetic acid added to culture medium was taken up rapidly by L6 cells, and AMPK was phosphorylated upon treatment with acetic acid. We observed increased gene and protein expression of GLUT4 and myoglobin. Uptake of glucose and fatty acids by L6 cells were increased, while triglyceride accumulation was lower in treated cells compared to untreated cells. Furthermore, treated cells also showed increased gene and protein expression of myocyte enhancer factor 2A (MEF2A), which is a well-known transcription factor involved in the expression of myoglobin and GLUT4 genes. These results indicate that acetic acid enhances glucose uptake and fatty acid metabolism through the activation of AMPK, and increases expression of GLUT4 and myoglobin.

  15. Immunosuppressive activity enhances central carbon metabolism and bioenergetics in myeloid-derived suppressor cells in vitro models

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    Hammami Ines

    2012-07-01

    Full Text Available Abstract Background The tumor microenvironment contains a vast array of pro- and anti-inflammatory cytokines that alter myelopoiesis and lead to the maturation of immunosuppressive cells known as myeloid-derived suppressor cells (MDSCs. Incubating bone marrow (BM precursors with a combination of granulocyte-macrophage colony-stimulating factor (GM-CSF and interleukin-6 (IL-6 generated a tumor-infiltrating MDSC-like population that impaired anti-tumor specific T-cell functions. This in vitro experimental approach was used to simulate MDSC maturation, and the cellular metabolic response was then monitored. A complementary experimental model that inhibited L-arginine (L-Arg metabolizing enzymes in MSC-1 cells, an immortalized cell line derived from primary MDSCs, was used to study the metabolic events related to immunosuppression. Results Exposure of BM cells to GM-CSF and IL-6 activated, within 24 h, L-Arg metabolizing enzymes which are responsible for the MDSCs immunosuppressive potential. This was accompanied by an increased uptake of L-glutamine (L-Gln and glucose, the latter being metabolized by anaerobic glycolysis. The up-regulation of nutrient uptake lead to the accumulation of TCA cycle intermediates and lactate as well as the endogenous synthesis of L-Arg and the production of energy-rich nucleotides. Moreover, inhibition of L-Arg metabolism in MSC-1 cells down-regulated central carbon metabolism activity, including glycolysis, glutaminolysis and TCA cycle activity, and led to a deterioration of cell bioenergetic status. The simultaneous increase of cell specific concentrations of ATP and a decrease in ATP-to-ADP ratio in BM-derived MDSCs suggested cells were metabolically active during maturation. Moreover, AMP-activated protein kinase (AMPK was activated during MDSC maturation in GM-CSF and IL-6–treated cultures, as revealed by the continuous increase of AMP-to-ATP ratios and the phosphorylation of AMPK. Likewise, AMPK activity was

  16. Metabolic profiles and free radical scavenging activity of Cordyceps bassiana fruiting bodies according to developmental stage.

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    Sun-Hee Hyun

    Full Text Available The metabolic profiles of Cordyceps bassiana according to fruiting body developmental stage were investigated using gas chromatography-mass spectrometry. We were able to detect 62 metabolites, including 48 metabolites from 70% methanol extracts and 14 metabolites from 100% n-hexane extracts. These metabolites were classified as alcohols, amino acids, organic acids, phosphoric acids, purine nucleosides and bases, sugars, saturated fatty acids, unsaturated fatty acids, or fatty amides. Significant changes in metabolite levels were found according to developmental stage. Relative levels of amino acids, purine nucleosides, and sugars were higher in development stage 3 than in the other stages. Among the amino acids, valine, isoleucine, lysine, histidine, glutamine, and aspartic acid, which are associated with ABC transporters and aminoacyl-tRNA biosynthesis, also showed higher levels in stage 3 samples. The free radical scavenging activities, which were significantly higher in stage 3 than in the other stages, showed a positive correlation with purine nucleoside metabolites such as adenosine, guanosine, and inosine. These results not only show metabolic profiles, but also suggest the metabolic pathways associated with fruiting body development stages in cultivated C. bassiana.

  17. Metabolically Activated Adipose Tissue Macrophages Perform Detrimental and Beneficial Functions during Diet-Induced Obesity.

    Science.gov (United States)

    Coats, Brittney R; Schoenfelt, Kelly Q; Barbosa-Lorenzi, Valéria C; Peris, Eduard; Cui, Chang; Hoffman, Alexandria; Zhou, Guolin; Fernandez, Sully; Zhai, Lijie; Hall, Ben A; Haka, Abigail S; Shah, Ajay M; Reardon, Catherine A; Brady, Matthew J; Rhodes, Christopher J; Maxfield, Frederick R; Becker, Lev

    2017-09-26

    During obesity, adipose tissue macrophages (ATMs) adopt a metabolically activated (MMe) phenotype. However, the functions of MMe macrophages are poorly understood. Here, we combine proteomic and functional methods to demonstrate that, in addition to potentiating inflammation, MMe macrophages promote dead adipocyte clearance through lysosomal exocytosis. We identify NADPH oxidase 2 (NOX2) as a driver of the inflammatory and adipocyte-clearing properties of MMe macrophages and show that, compared to wild-type, Nox2-/- mice exhibit a time-dependent metabolic phenotype during diet-induced obesity. After 8 weeks of high-fat feeding, Nox2-/- mice exhibit attenuated ATM inflammation and mildly improved glucose tolerance. After 16 weeks of high-fat feeding, Nox2-/- mice develop severe insulin resistance, hepatosteatosis, and visceral lipoatrophy characterized by dead adipocyte accumulation and defective ATM lysosomal exocytosis, a phenotype reproduced in myeloid cell-specific Nox2-/- mice. Collectively, our findings suggest that MMe macrophages perform detrimental and beneficial functions whose contribution to metabolic phenotypes during obesity is determined by disease progression. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Metabolically Activated Adipose Tissue Macrophages Perform Detrimental and Beneficial Functions during Diet-Induced Obesity

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    Brittney R. Coats

    2017-09-01

    Full Text Available During obesity, adipose tissue macrophages (ATMs adopt a metabolically activated (MMe phenotype. However, the functions of MMe macrophages are poorly understood. Here, we combine proteomic and functional methods to demonstrate that, in addition to potentiating inflammation, MMe macrophages promote dead adipocyte clearance through lysosomal exocytosis. We identify NADPH oxidase 2 (NOX2 as a driver of the inflammatory and adipocyte-clearing properties of MMe macrophages and show that, compared to wild-type, Nox2−/− mice exhibit a time-dependent metabolic phenotype during diet-induced obesity. After 8 weeks of high-fat feeding, Nox2−/− mice exhibit attenuated ATM inflammation and mildly improved glucose tolerance. After 16 weeks of high-fat feeding, Nox2−/− mice develop severe insulin resistance, hepatosteatosis, and visceral lipoatrophy characterized by dead adipocyte accumulation and defective ATM lysosomal exocytosis, a phenotype reproduced in myeloid cell-specific Nox2−/− mice. Collectively, our findings suggest that MMe macrophages perform detrimental and beneficial functions whose contribution to metabolic phenotypes during obesity is determined by disease progression.

  19. Metabolic profile and underlying improved bio-activity of Fructus aurantii immaturus by human intestinal bacteria.

    Science.gov (United States)

    Liu, Xing Yan; Fan, Meng Lin; Wang, Huai You; Yu, Bo Yang; Liu, Ji Hua

    2017-06-21

    Fructus aurantii immaturus (FAI) is the dried young fruit of Citrus aurantium L. or Citrus sinensis L. Osbeck. The purpose of this paper was to investigate the metabolic fate of FAI upon incubation with human intestinal bacteria, meanwhile to evaluate the antioxidant and anti-inflammatory activities of FAI and the transformed Fructus aurantii immaturus (TFAI). The water extract of FAI was anaerobically incubated with human intestinal bacterial suspensions for 48 h at 37 °C. Liquid chromatography-hybridised with quadrupole-time-of-flight mass spectrometry (LC-Q-TOF/MS) was applied to identify FAI metabolites. A total of 45 compounds were identified in FAI, eleven of which were metabolized by human intestinal bacteria. Nine major metabolites were identified as eriodictyol, naringenin, hesperetin, luteolin, apigenin, chryseriol, isosakuranetin, phloretin and diosmetin. The metabolic profile of FAI was elucidated on the basis of metabolite information. We found that the concentrations of acetic, propionic and butyric acids in FAI culture were all increased during fermentation relative to those of the control. Further bioactive evaluations showed that TFAI exhibited more potent antioxidant and anti-inflammatory abilities than FAI in vitro. Additionally, in vivo experiment confirmed that FAI significantly attenuated the blood endotoxin and TNF-α levels in the conventional rats compared to those of pseudo-germ-free (PGF) rats. This study revealed that metabolites may play a key role in the antioxidant and anti-inflammatory capacities of FAI.

  20. Hydrodynamics-Based Functional Forms of Activity Metabolism: A Case for the Power-Law Polynomial Function in Animal Swimming Energetics

    OpenAIRE

    Anthony Papadopoulos

    2009-01-01

    The first-degree power-law polynomial function is frequently used to describe activity metabolism for steady swimming animals. This function has been used in hydrodynamics-based metabolic studies to evaluate important parameters of energetic costs, such as the standard metabolic rate and the drag power indices. In theory, however, the power-law polynomial function of any degree greater than one can be used to describe activity metabolism for steady swimming animals. In fact, activity metaboli...

  1. Effects of sex and site on amino acid metabolism enzyme gene expression and activity in rat white adipose tissue

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    Sofía Arriarán

    2015-11-01

    Full Text Available Background and Objectives. White adipose tissue (WAT shows marked sex- and diet-dependent differences. However, our metabolic knowledge of WAT, especially on amino acid metabolism, is considerably limited. In the present study, we compared the influence of sex on the amino acid metabolism profile of the four main WAT sites, focused on the paths related to ammonium handling and the urea cycle, as a way to estimate the extent of WAT implication on body amino-nitrogen metabolism.Experimental Design. Adult female and male rats were maintained, undisturbed, under standard conditions for one month. After killing them under isoflurane anesthesia. WAT sites were dissected and weighed. Subcutaneous, perigonadal, retroperitoneal and mesenteric WAT were analyzed for amino acid metabolism gene expression and enzyme activities.Results. There was a considerable stability of the urea cycle activities and expressions, irrespective of sex, and with only limited influence of site. Urea cycle was more resilient to change than other site-specialized metabolic pathways. The control of WAT urea cycle was probably related to the provision of arginine/citrulline, as deduced from the enzyme activity profiles. These data support a generalized role of WAT in overall amino-N handling. In contrast, sex markedly affected WAT ammonium-centered amino acid metabolism in a site-related way, with relatively higher emphasis in males’ subcutaneous WAT.Conclusions. We found that WAT has an active amino acid metabolism. Its gene expressions were lower than those of glucose-lipid interactions, but the differences were quantitatively less important than usually reported. The effects of sex on urea cycle enzymes expression and activity were limited, in contrast with the wider variations observed in other metabolic pathways. The results agree with a centralized control of urea cycle operation affecting the adipose organ as a whole.

  2. Metabolic Potential and Activity in Fluids of the Coast Range Ophiolite Microbial Observatory, California, USA

    Science.gov (United States)

    Hoehler, T.; Som, S.; Schrenk, M.; McCollom, T.; Cardace, D.

    2016-01-01

    Metabolic potential and activity associated with hydrogen and carbon monoxide were characterized in fluids sampled from the the Coast Range Ophiolite Microbial Observatory (CROMO). CROMO consists of two clusters of science-dedicated wells drilled to varying depths up to 35m in the actively serpentinizing, Jurassic-age Coast Range Ophiolite of Northern California, along with a suite of pre-existing monitoring wells at the same site. Consistent with the fluid chemistry observed in other serpentinizing systems, CROMO fluids are highly alkaline, with pH up to 12.5, high in methane, with concentrations up 1600 micromolar, and low in dissolved inorganic carbon (DIC), with concentrations of 10's to 100's of micromolar. CROMO is conspicuous for fluid H2 concentrations that are consistently sub-micromolar, orders of magnitude lower than is typical of other systems. However, higher H2 concentrations (10's -100's of micromolar) at an earlier stage of fluid chemical evolution are predicted by, or consistent with: thermodynamic models for fluid chemistry based on parent rock composition equivalent to local peridotite and with water:rock ratio constrained by observed pH; the presence of magnetite at several wt% in CROMO drill cores; and concentrations of formate and carbon monoxide that would require elevated H2 if formed in equilibrium with H2 and DIC. Calculated Gibbs energy changes for reaction of H2 and CO in each of several metabolisms, across the range of fluid composition encompassed by the CROMO wells, range from bioenergetically feasible (capable of driving ATP synthesis) to thermodynamically unfavorable. Active consumption relative to killed controls was observed for both CO and H2 during incubation of fluids from the pre-existing monitoring wells; in incubations of freshly cored solids, consumption was only observed in one sample set (corresponding to the lowest pH) out of three. The specific metabolisms by which H2 and CO are consumed remain to be determined.

  3. Modeling and Classification of Kinetic Patterns of Dynamic Metabolic Biomarkers in Physical Activity.

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    Marc Breit

    2015-08-01

    Full Text Available The objectives of this work were the classification of dynamic metabolic biomarker candidates and the modeling and characterization of kinetic regulatory mechanisms in human metabolism with response to external perturbations by physical activity. Longitudinal metabolic concentration data of 47 individuals from 4 different groups were examined, obtained from a cycle ergometry cohort study. In total, 110 metabolites (within the classes of acylcarnitines, amino acids, and sugars were measured through a targeted metabolomics approach, combining tandem mass spectrometry (MS/MS with the concept of stable isotope dilution (SID for metabolite quantitation. Biomarker candidates were selected by combined analysis of maximum fold changes (MFCs in concentrations and P-values resulting from statistical hypothesis testing. Characteristic kinetic signatures were identified through a mathematical modeling approach utilizing polynomial fitting. Modeled kinetic signatures were analyzed for groups with similar behavior by applying hierarchical cluster analysis. Kinetic shape templates were characterized, defining different forms of basic kinetic response patterns, such as sustained, early, late, and other forms, that can be used for metabolite classification. Acetylcarnitine (C2, showing a late response pattern and having the highest values in MFC and statistical significance, was classified as late marker and ranked as strong predictor (MFC = 1.97, P < 0.001. In the class of amino acids, highest values were shown for alanine (MFC = 1.42, P < 0.001, classified as late marker and strong predictor. Glucose yields a delayed response pattern, similar to a hockey stick function, being classified as delayed marker and ranked as moderate predictor (MFC = 1.32, P < 0.001. These findings coincide with existing knowledge on central metabolic pathways affected in exercise physiology, such as β-oxidation of fatty acids, glycolysis, and glycogenolysis. The presented modeling

  4. Effect of benomyl and thiophanate-methyl on metabolic activities of Rhizoctonia solani Kühn.

    Science.gov (United States)

    Kataria, H R; Grover, R K

    1976-01-01

    Effect of benomyl and thiophanate-methyl on various metabolic activities of Rhizoctonia solani was investigated. Both fungitoxicants strongly reduced endogenous whole cell and mitochondrial respiration by inhibiting one or the other key enzymes of electron transport chain; the activity of cytochrome oxidase being most markedly inhibited. Incorporation of 3II-thymidine was reduced by both while there was little or no inhibition in the rate of incorporation of 14C-uracil and 14C-leucine. Cell permeability was not affected to any appreciable extent and there was a little release of cellular components from the treated cells only at prolonged incubation. It is concluded that benomyl and thiophanate-methyl have a similar mode of action which primarily involves inhibition of respiratory activities, and as a consequence the biosynthesis of DNA is reduced.

  5. Tempol Supplementation Restores Diaphragm Force and Metabolic Enzyme Activities in mdx Mice

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    David P. Burns

    2017-12-01

    Full Text Available Duchenne muscular dystrophy (DMD is characterized by striated muscle weakness, cardiomyopathy, and respiratory failure. Since oxidative stress is recognized as a secondary pathology in DMD, the efficacy of antioxidant intervention, using the superoxide scavenger tempol, was examined on functional and biochemical status of dystrophin-deficient diaphragm muscle. Diaphragm muscle function was assessed, ex vivo, in adult male wild-type and dystrophin-deficient mdx mice, with and without a 14-day antioxidant intervention. The enzymatic activities of muscle citrate synthase, phosphofructokinase, and lactate dehydrogenase were assessed using spectrophotometric assays. Dystrophic diaphragm displayed mechanical dysfunction and altered biochemical status. Chronic tempol supplementation in the drinking water increased diaphragm functional capacity and citrate synthase and lactate dehydrogenase enzymatic activities, restoring all values to wild-type levels. Chronic supplementation with tempol recovers force-generating capacity and metabolic enzyme activity in mdx diaphragm. These findings may have relevance in the search for therapeutic strategies in neuromuscular disease.

  6. The etiology of obesity: relative contribution of metabolic factors, diet, and physical activity.

    Science.gov (United States)

    Weinsier, R L; Hunter, G R; Heini, A F; Goran, M I; Sell, S M

    1998-08-01

    Three major factors modulate body weight: metabolic factors, diet, and physical activity, each influenced by genetic traits. Despite recent advances in these areas, the prevalence of obesity in Westernized societies has increased. In contrast to monogenic animal models and rare human genetic syndromes, predisposition to common forms of obesity is probably influenced by numerous susceptibility genes, accounting for variations in energy requirements, fuel utilization, muscle metabolic characteristics, and taste preferences. Although recent increases in obesity prevalence cannot be explained by changes in the gene pool, previously "silent" genetic variants may now play important permissive roles in modern societies. Available data suggest that variations in resting energy expenditure, thermic effect of food, and fuel utilization exist but, by themselves, are unlikely to explain the onset of obesity. Regarding diet, the best available trend survey data indicate that fat and energy intake have fallen, in this and other Westernized countries. Diverging trends of decreasing energy intake and increasing body weight suggest that reduced physical activity may be the most important current factor explaining the rising prevalence of obesity. Subsistence in modern societies requires extreme adaptations in previously useful energy-conserving diet and exercise behaviors. Recognizing the difficulties in sustaining energy-restricted diets in the presence of fast foods and social feasts, the current trend toward increasing body weight is not likely to be reversed solely through recommendations for further reductions in energy intake. In all likelihood, activity levels will have to increase in response to an environment engineered to be more physically demanding.

  7. Markers of sympathetic nervous system activity associate with complex plasma lipids in metabolic syndrome subjects.

    Science.gov (United States)

    Nestel, Paul J; Khan, Anmar A; Straznicky, Nora E; Mellett, Natalie A; Jayawardana, Kaushala; Mundra, Piyushkumar A; Lambert, Gavin W; Meikle, Peter J

    2017-01-01

    Plasma sphingolipids including ceramides, and gangliosides are associated with insulin resistance (IR) through effects on insulin signalling and glucose metabolism. Our studies of subjects with metabolic syndrome (MetS) showed close relationships between IR and sympathetic nervous system (SNS) activity including arterial norepinephrine (NE). We have therefore investigated possible associations of IR and SNS activity with complex lipids that are involved in both insulin sensitivity and neurotransmission. We performed a cross-sectional assessment of 23 lipid classes/subclasses (total 339 lipid species) by tandem mass spectrometry in 94 overweight untreated subjects with IR (quantified by HOMA-IR, Matsuda index and plasma insulin). Independently of IR parameters, several circulating complex lipids associated significantly with arterial NE and NEFA (non-esterified fatty acids) and marginally with heart rate (HR). After accounting for BMI, HOMA-IR, systolic BP, age, gender, and correction for multiple comparisons, these associations were significant (p 0.05) with ceramide, GM3 ganglioside, sphingomyelin, lysophosphatidylcholine, phosphatidylinositol, lysophosphatidylinositol and free cholesterol. Multiple subspecies of these lipids significantly associated with NE and NEFA. None of the IR biomarkers associated significantly with lipid classes/subclasses after correction for multiple comparisons. This is the first demonstration that arterial norepinephrine and NEFA, that reflect both SNS activity and IR, associate significantly with circulating complex lipids independently of IR, suggesting a role for such lipids in neural mechanisms operating in MetS. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. The Emerging Nexus of Active DNA Demethylation and Mitochondrial Oxidative Metabolism in Post-Mitotic Neurons

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    Huan Meng

    2014-12-01

    Full Text Available The variable patterns of DNA methylation in mammals have been linked to a number of physiological processes, including normal embryonic development and disease pathogenesis. Active removal of DNA methylation, which potentially regulates neuronal gene expression both globally and gene specifically, has been recently implicated in neuronal plasticity, learning and memory processes. Model pathways of active DNA demethylation involve ten-eleven translocation (TET methylcytosine dioxygenases that are dependent on oxidative metabolites. In addition, reactive oxygen species (ROS and oxidizing agents generate oxidative modifications of DNA bases that can be removed by base excision repair proteins. These potentially link the two processes of active DNA demethylation and mitochondrial oxidative metabolism in post-mitotic neurons. We review the current biochemical understanding of the DNA demethylation process and discuss its potential interaction with oxidative metabolism. We then summarise the emerging roles of both processes and their interaction in neural plasticity and memory formation and the pathophysiology of neurodegeneration. Finally, possible therapeutic approaches for neurodegenerative diseases are proposed, including reprogramming therapy by global DNA demethylation and mitohormesis therapy for locus-specific DNA demethylation in post-mitotic neurons.

  9. Stoichiometry and kinetics of poly-{beta}-hydroxybutyrate metabolism in aerobic, slow growing, activated sludge cultures

    Energy Technology Data Exchange (ETDEWEB)

    Beun, J.J.; Paletta, F.; Loosdrecht, M.C.M. Van; Heijnen, J.J.

    2000-02-20

    This paper discusses the poly-{beta}-hydroxybutyrate (PHB) metabolism in aerobic, slow growing, activated sludge cultures, based on experimental data and on a metabolic model. The dynamic conditions which occur in activated sludge processes were simulated in a 2-L sequencing batch reactor (SBR) by subjecting a mixed microbial population to successive periods of external substrate availability (feast period) and no external substrate availability (famine period). Under these conditions intracellular storage and consumption of PHB was observed. It appeared that in the feast period, 66% to almost 100% of the substrate consumed is used for storage of PHB, the remainder is used for growth and maintenance processes. Furthermore, it appeared that at high sludge retention time (SRT) the growth rate in the feast and famine periods was the same. With decreasing SRT the growth rate in the feast period increased relative to the growth rate in the famine period. Acetate consumption and PHB production in the feast period both proceeded with a zero-order rate in acetate and PHB concentration respectively. PHB consumption in the famine period could best be described kinetically with a nth order degradation equation in PHB concentration. The obtained results are discussed in the context of the general activated sludge models.

  10. Physical activity, Cardio-Respiratory Fitness, and Metabolic Traits in Rural Mexican Tarahumara

    DEFF Research Database (Denmark)

    Christensen, Dirk Lund; Alcala-Sanchez, Imelda; Leal-Berumen, Irene

    2012-01-01

    Objectives: To study the association between physical activity energy expenditure (PAEE) and cardio-respiratory fitness (CRF) with key metabolic traits and anthropometric measures in the Tarahumara of Mexico. Methods: A cross-sectional study was carried out in five rural communities in Chihuahua......, Me´xico including 64 adult Tarahumara, mean (SD) age 40.7 (12.9) years. Using a combined accelerometer and heart rate sensor, PAEE was measured over three consecutive days and nights and a sub-maximal step test was carried out in order to (1) calibrate heart rate at the individual level and (2...

  11. Reduction in hepatic drug metabolizing CYP3A4 activities caused by P450 oxidoreductase mutations identified in patients with disordered steroid metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Flueck, Christa E.; Mullis, Primus E. [Pediatric Endocrinology, Diabetology and Metabolism, Department of Clinical Research, University of Bern, Tiefenaustrasse 120c, CH 3004 Bern (Switzerland); Pandey, Amit V., E-mail: amit@pandeylab.org [Pediatric Endocrinology, Diabetology and Metabolism, Department of Clinical Research, University of Bern, Tiefenaustrasse 120c, CH 3004 Bern (Switzerland)

    2010-10-08

    Research highlights: {yields} Cytochrome P450 3A4 (CYP3A4), metabolizes 50% of drugs in clinical use and requires NADPH-P450 reductase (POR). {yields} Mutations in human POR cause congenital adrenal hyperplasia from diminished activities of steroid metabolizing P450s. {yields} We are reporting that mutations in POR may reduce CYP3A4 activity. {yields} POR mutants Y181D, A457H, Y459H, V492E and R616X lost 99%, while A287P, C569Y and V608F lost 60-85% CYP3A4 activity. {yields} Reduction of CYP3A4 activity may cause increased risk of drug toxicities/adverse drug reactions in patients with POR mutations. -- Abstract: Cytochrome P450 3A4 (CYP3A4), the major P450 present in human liver metabolizes approximately half the drugs in clinical use and requires electrons supplied from NADPH through NADPH-P450 reductase (POR, CPR). Mutations in human POR cause a rare form of congenital adrenal hyperplasia from diminished activities of steroid metabolizing P450s. In this study we examined the effect of mutations in POR on CYP3A4 activity. We used purified preparations of wild type and mutant human POR and in vitro reconstitution with purified CYP3A4 to perform kinetic studies. We are reporting that mutations in POR identified in patients with disordered steroidogenesis/Antley-Bixler syndrome (ABS) may reduce CYP3A4 activity, potentially affecting drug metabolism in individuals carrying mutant POR alleles. POR mutants Y181D, A457H, Y459H, V492E and R616X had more than 99% loss of CYP3A4 activity, while POR mutations A287P, C569Y and V608F lost 60-85% activity. Loss of CYP3A4 activity may result in increased risk of drug toxicities and adverse drug reactions in patients with POR mutations.

  12. Metabolically inert perfluorinated fatty acids directly activate uncoupling protein 1 in brown-fat mitochondria.

    Science.gov (United States)

    Shabalina, Irina G; Kalinovich, Anastasia V; Cannon, Barbara; Nedergaard, Jan

    2016-05-01

    The metabolically inert perfluorinated fatty acids perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) can display fatty acid-like activity in biological systems. The uncoupling protein 1 (UCP1) in brown adipose tissue is physiologically (re)activated by fatty acids, including octanoate. This leads to bioenergetically uncoupled energy dissipation (heat production, thermogenesis). We have examined here the possibility that PFOA/PFOS can directly (re)activate UCP1 in isolated mouse brown-fat mitochondria. In wild-type brown-fat mitochondria, PFOS and PFOA overcame GDP-inhibited thermogenesis, leading to increased oxygen consumption and dissipated membrane potential. The absence of this effect in brown-fat mitochondria from UCP1-ablated mice indicated that it occurred through activation of UCP1. A competitive type of inhibition by increased GDP concentrations indicated interaction with the same mechanistic site as that utilized by fatty acids. No effect was observed in heart mitochondria, i.e., in mitochondria without UCP1. The stimulatory effect of PFOA/PFOS was not secondary to non-specific mitochondrial membrane permeabilization or to ROS production. Thus, metabolic effects of perfluorinated fatty acids could include direct brown adipose tissue (UCP1) activation. The possibility that this may lead to unwarranted extra heat production and thus extra utilization of food resources, leading to decreased fitness in mammalian wildlife, is discussed, as well as possible negative effects in humans. However, a possibility to utilize PFOA-/PFOS-like substances for activating UCP1 therapeutically in obesity-prone humans may also be envisaged.

  13. Associations of visceral fat, physical activity and muscle strength with the metabolic syndrome.

    Science.gov (United States)

    Bisschop, Charlotte N Steins; Peeters, Petra H M; Monninkhof, Evelyn M; van der Schouw, Yvonne T; May, Anne M

    2013-10-01

    We investigated the association of visceral fat with the metabolic syndrome (MetS) and its separate components; the associations of both physical activity and muscle strength with the MetS and its separate components independent of visceral fat. Furthermore, we studied these associations within participants with low and high amounts of visceral fat. 400 men (aged 40-80 years) were recruited into a cross-sectional study. Logistic regression models were used to study the individual associations in all participants (OR). The associations of physical activity (active vs inactive) and muscle strength (high vs low) within participants with low and high levels of visceral fat (assessed by ultrasonography) were tested using Univariate Analysis of Variance (difference in mean levels of the separate components of MetS) and logistic regression (risk on MetS). High levels of visceral fat were significantly associated with increased risk of MetS (OR 1.7 95%CI 1.5;1.9) and its separate components (pphysical activity or muscle strength, neither within men with low or high levels of visceral fat. High body fat levels were associated with an unhealthier metabolic risk profile and a higher risk of the MetS. Our cross-sectional data do not indicate associations for physical activity or for muscle strength with the MetS independent of visceral fat. Also no differential associations of physical activity or muscle strength in men with low or high levels of visceral fat were found. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Dietary patterns as compared with physical activity in relation to metabolic syndrome among Chinese adults.

    Science.gov (United States)

    He, Y; Li, Y; Lai, J; Wang, D; Zhang, J; Fu, P; Yang, X; Qi, L

    2013-10-01

    To examine the nationally-representative dietary patterns and their joint effects with physical activity on the likelihood of metabolic syndrome (MS) among 20,827 Chinese adults. CNNHS was a nationally representative cross-sectional observational study. Metabolic syndrome was defined according to the Joint Interim Statement definition. The "Green Water" dietary pattern, characterized by high intakes of rice and vegetables and moderate intakes in animal foods was related to the lowest prevalence of MS (15.9%). Compared to the "Green Water" dietary pattern, the "Yellow Earth" dietary pattern, characterized by high intakes of refined cereal products, tubers, cooking salt and salted vegetable was associated with a significantly elevated odds of MS (odds ratio 1.66, 95%CI: 1.40-1.96), after adjustment of age, sex, socioeconomic status and lifestyle factors. The "Western/new affluence" dietary pattern characterized by higher consumption of beef/lamb, fruit, eggs, poultry and seafood also significantly associated with MS (odds ratio: 1.37, 95%CI: 1.13-1.67). Physical activity showed significant interactions with the dietary patterns in relation to MS risk (P for interaction = 0.008). In the joint analysis, participants with the combination of sedentary activity with the "Yellow Earth" dietary pattern or the "Western/new affluence" dietary pattern both had more than three times (95%CI: 2.8-6.1) higher odds of MS than those with active activity and the "Green Water" dietary pattern. Our findings from the large Chinese national representative data indicate that dietary patterns affect the likelihood of MS. Combining healthy dietary pattern with active lifestyle may benefit more in prevention of MS. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Familial Resemblance of Body Composition, Physical Activity, and Resting Metabolic Rate in Pre-School Children

    Directory of Open Access Journals (Sweden)

    Kurosh Djafarian

    2013-10-01

    Full Text Available Background: Although parental obesity is a well-established predisposing factor for the development of obesity, associations