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Sample records for affects selenium bioavailability

  1. Ethanol Consumption by Wistar Rat Dams Affects Selenium Bioavailability and Antioxidant Balance in Their Progeny

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    Olimpia Carreras

    2009-07-01

    Full Text Available Ethanol consumption affects maternal nutrition, the mothers’ antioxidant balance and the future health of their progeny. Selenium (Se is a trace element cofactor of the enzyme glutathione peroxidase (GPx. We will study the effect of ethanol on Se bioavailability in dams and in their progeny. We have used three experimental groups of dams: control, chronic ethanol and pair-fed; and three groups of pups. Se levels were measured by graphite-furnace atomic absorption spectrometry. Serum and hepatic GPx activity was determined by spectrometry. We have concluded that ethanol decreased Se retention in dams, affecting their tissue Se deposits and those of their offspring, while also compromising their progeny’s weight and oxidation balance. These effects of ethanol are caused by a reduction in Se intake and a direct alcohol-generated oxidation action.

  2. Selenium bioavailability and uptake as affected by four different plants in a loamy clay soil with particular attention to mycorrhizae inoculated ryegrass

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the influence of plant species, especially of their rhizosphere soil, and of inoculation with an arbuscular mycorrhizal (AM) fungus on the bioavailability of selenium and its transfer in soil-plant systems. A pot experiment was performed with a loamy clay soil and four plant species: maize, lettuce, radish and ryegrass, the last one being inoculated or not with an arbuscular mycorrhizal fungus (Glomus mosseae). Plant biomass and Se concentration in shoots and roots were estimated at harvest. Se bioavailability in rhizosphere and unplanted soil was evaluated using sequential extractions. Plant biomass and selenium uptake varied with plant species. The quantity of rhizosphere soil also differed between plants and was not proportional to plant biomass. The highest plant biomass, Se concentration in plants, and soil to plant transfer factor were obtained with radish. The lowest Se transfer factors were obtained with ryegrass. For the latter, mycorrhizal inoculation did not significantly affect plant growth, but reduced selenium transfer from soil to plant by 30%. In unplanted soil after 65 days aging, more than 90% of added Se was water-extractable. On the contrary, Se concentration in water extracts of rhizosphere soil represented less than 1% and 20% of added Se for ryegrass and maize, respectively. No correlation was found between the water-extractable fraction and Se concentration in plants. The speciation of selenium in the water extracts indicated that selenate was reduced, may be under organic forms, in the rhizosphere soil

  3. Selenium bioavailability and uptake as affected by four different plants in a loamy clay soil with particular attention to mycorrhizae inoculated ryegrass

    Energy Technology Data Exchange (ETDEWEB)

    Munier-Lamy, C. [LIMOS, UMR 7137 CNRS-Nancy University, Faculty of Sciences, P.O. Box 239, F-54506 Vandoeuvre-les-Nancy Cedex (France)], E-mail: colette.munier@limos.uhp-nancy.fr; Deneux-Mustin, S. [LIMOS, UMR 7137 CNRS-Nancy University, Faculty of Sciences, P.O. Box 239, F-54506 Vandoeuvre-les-Nancy Cedex (France); Mustin, C. [LIMOS, UMR 7137 CNRS-Nancy University, Faculty of Sciences, P.O. Box 239, F-54506 Vandoeuvre-les-Nancy Cedex (France)], E-mail: christian.mustin@limos.uhp-nancy.fr; Merlet, D. [LIMOS, UMR 7137 CNRS-Nancy University, Faculty of Sciences, P.O. Box 239, F-54506 Vandoeuvre-les-Nancy Cedex (France)], E-mail: denis.merlet@limos.uhp-nancy.fr; Berthelin, J. [LIMOS, UMR 7137 CNRS-Nancy University, Faculty of Sciences, P.O. Box 239, F-54506 Vandoeuvre-les-Nancy Cedex (France)], E-mail: jacques.berthelin@limos.uhp-nancy.fr; Leyval, C. [LIMOS, UMR 7137 CNRS-Nancy University, Faculty of Sciences, P.O. Box 239, F-54506 Vandoeuvre-les-Nancy Cedex (France)], E-mail: corinne.leyval@limos.uhp-nancy.fr

    2007-10-15

    The aim of this study was to investigate the influence of plant species, especially of their rhizosphere soil, and of inoculation with an arbuscular mycorrhizal (AM) fungus on the bioavailability of selenium and its transfer in soil-plant systems. A pot experiment was performed with a loamy clay soil and four plant species: maize, lettuce, radish and ryegrass, the last one being inoculated or not with an arbuscular mycorrhizal fungus (Glomus mosseae). Plant biomass and Se concentration in shoots and roots were estimated at harvest. Se bioavailability in rhizosphere and unplanted soil was evaluated using sequential extractions. Plant biomass and selenium uptake varied with plant species. The quantity of rhizosphere soil also differed between plants and was not proportional to plant biomass. The highest plant biomass, Se concentration in plants, and soil to plant transfer factor were obtained with radish. The lowest Se transfer factors were obtained with ryegrass. For the latter, mycorrhizal inoculation did not significantly affect plant growth, but reduced selenium transfer from soil to plant by 30%. In unplanted soil after 65 days aging, more than 90% of added Se was water-extractable. On the contrary, Se concentration in water extracts of rhizosphere soil represented less than 1% and 20% of added Se for ryegrass and maize, respectively. No correlation was found between the water-extractable fraction and Se concentration in plants. The speciation of selenium in the water extracts indicated that selenate was reduced, may be under organic forms, in the rhizosphere soil.

  4. Selenium bioavailability from naturally produced high-selenium peas and oats in selenium-deficient rats.

    Science.gov (United States)

    Yan, Lin; Johnson, LuAnn K

    2011-06-01

    This study determined the bioavailability of selenium (Se) from yellow peas and oats harvested from the high-Se soil of South Dakota, United States. The Se concentrations were 13.5 ± 0.2 and 2.5 ± 0.1 mg/kg (dry weight) for peas and oats, respectively. Male weanling Sprague-Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet (4.1 μg Se/kg) for 56 days, and then they were replenished with Se for an additional 50 days by feeding them the same diet supplemented with 20, 30, or 40 μg Se/kg from peas or oats, respectively. Selenium bioavailability was determined on the basis of the restoration of Se-dependent enzyme activities and tissue Se concentrations in Se-depleted rats, comparing those responses for yellow peas and oats to those for l-selenomethionine (SeMet; used as a reference) by using a slope-ratio method. Dietary supplementation with peas or oats resulted in linear or log-linear, dose-dependent increases in glutathione peroxidase activities in blood and liver and in thioredoxin reductase activity in liver. Supplementation with peas or oats resulted in linear or log-linear, dose-dependent increases in Se concentrations of plasma, liver, gastrocnemius muscle, and kidneys. The overall bioavailability was approximately 88% for Se from yellow peas and 92% from oats, compared to SeMet. It was concluded that Se from naturally produced high-Se yellow peas or oats is highly bioavailable in this model and that these high-Se foods may be a good dietary source of Se. PMID:21553810

  5. Bioavailability of selenium from fish, yeast and selenate: A comparative study in humans using stable isotopes

    NARCIS (Netherlands)

    Fox, T.E.; Heuvel, E.G.H.M. van den; Atherton, C.A.; Dainty, J.R.; Lewis, D.J.; Langford, N.J.; Crews, H.M.; Luten, J.B.; Lorentzen, M.; Sieling, F.W.; Aken-Schneyder, P. van; Hoek, M.; Kotterman, M.J.J.; Dael, P. van; Firweather-Tail, S.J.

    2004-01-01

    Objective: To measure the bioavailability of selenium from cooked and raw fish in humans by estimating and comparing apparent absorption and retention of selenium in biosynthetically labelled fish with labelled selenate and biosynthetically labelled selenium in brewers yeast. Design: The interventio

  6. Does selenium supplementation affect thyroid function?

    DEFF Research Database (Denmark)

    Winther, Kristian Hillert; Bonnema, Steen Joop; Cold, Frederik;

    2015-01-01

    OBJECTIVE: Selenium is present in the active site of proteins important for thyroid hormone synthesis and metabolism. The objective of this study is to investigate the effect of selenium supplementation in different doses on thyroid function, under conditions of suboptimal dietary selenium intake......, and after 6 months, and 5 years of supplementation. RESULTS: Plasma selenium concentrations increased significantly and dose-dependently in treatment groups receiving selenium (P<0.001). Serum TSH and FT4 concentrations decreased significantly and dose-dependently by 0.066 mIU/l (P=0.010) and 0.......11 pmol/l (P=0.015), respectively, per 100 μg/day increase, with insignificant differences between 6 months and 5 years. No significant effects were found for FT3 and FT3:FT4 ratio. CONCLUSIONS: In euthyroid subjects, selenium supplementation minutely and dose-dependently affects thyroid function, when...

  7. Rumen Microorganisms Decrease Bioavailability of Inorganic Selenium Supplements.

    Science.gov (United States)

    Galbraith, M L; Vorachek, W R; Estill, C T; Whanger, P D; Bobe, G; Davis, T Z; Hall, J A

    2016-06-01

    Despite the availability of selenium (Se)-enriched trace mineral supplements, we have observed low Se status in cattle and sheep offered traditional inorganic Se supplements. Reasons for this may include inadequate intake or low bioavailability of inorganic Se sources. The objective of this study was to determine whether rumen microorganisms (RMO) alter the bioavailability of Se sources commonly used in Se supplements. Rumen microorganisms were isolated from ewes (n = 4) and incubated ex vivo with no Se (control), with inorganic Na selenite or Na selenate, or with organic selenomethionine (SeMet). Total Se incorporated into RMO and the amount of elemental Se formed were determined under equivalent conditions. Incorporation of Se from Na selenite, Na selenate, or SeMet into RMO was measured as fold change compared with control (no added Se). Incorporation of Se into microbial mass was greater for SeMet (13.2-fold greater than no-Se control) compared with inorganic Se supplements (P = 0.02); no differences were observed between inorganic Na selenate (3.3-fold greater than no-Se control) and Na selenite (3.5-fold greater than no-Se control; P = 0.97). Formation of non-bioavailable, elemental Se was less for RMO incubated with SeMet compared with inorganic Se sources (P = 0.01); no differences were observed between Na selenate and Na selenite (P = 0.09). The clinical importance of these results is that the oral bioavailability of organic SeMet should be greater compared with inorganic Se sources because of greater RMO incorporation of Se and decreased formation of elemental Se by RMO. PMID:26537117

  8. Selenium Biochemistry and Bioavailability: Implications for Animal Agriculture

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    Shaniko Shini

    2015-12-01

    Full Text Available Selenium (Se is an essential trace mineral required for growth, development, immune function, and metabolism. Selenium exerts its biological effects as an integral component of selenoproteins (SePs. Deficiency or low Se status leads to marked changes in many biochemical pathways and a range of pathologies and disorders which are associated with SeP function. Animals, and presumably humans, are able to efficiently utilize nutritionally adequate levels of Se in both organic and inorganic forms. It is now clear that the bioavailability of Se varies depending on the source and chemical form of the Se supplement. There are a range of products available for dietary Se supplementation, however, organic sources have been shown to be assimilated more efficiently than inorganic compounds and are considered to be less toxic and more appropriate as a feed supplement. Yeast enriched with Selenohomoalanthionine (SeHLan has recently become commercially available, and initial research suggests that it may be an efficacious source for the production of Se enriched animal products.

  9. Speciation and bioavailability of selenium in yeast-based intervention agents used in cancer chemoprevention studies

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Hansen, Marianne; Paulin, H.; Moesgaard, S.; Reid, M.; Rayman, M.

    2004-01-01

    This study investigated the speciation and bioavailability of selenium in yeast-based intervention agents from multiple manufacturers from several time points. Sources of selenized yeast included Nutrition 21 (San Diego, CA), which supplied the Nutritional Prevention of Cancer (NPC) Trial from 1981......-1996; Cypress Systems (Fresno, CA; 1997-1999); and Pharma Nord (Vejle, Denmark; 1999-2000), which supplied the Prevention of Cancer by Intervention by Selenium (PRECISE) Trial pilot studies. The low-molecular-selenium species were liberated from the samples by proteolytic hydrolysis followed by separation by...

  10. BIOAVAILABILITY OF SELENIUM FROM MEAT AND BROCCOLI AS DETERMINED BY RETENTION AND DISTRIBUTION OF SE75

    Science.gov (United States)

    Meat is the single greatest source of selenium (Se) in the North American diet. Although not naturally enriched in Se, broccoli will accumulate Se when grown on high Se soils. Previous reports have demonstrated that Se from meat is highly bioavailable whereas Se from broccoli has poor bioavailabil...

  11. Selenium from Pinto Beans is Bioavailable to Support Bone Structure in Mice

    Science.gov (United States)

    Deficiency of selenium (Se), an essential trace mineral for animals and humans, has been shown to induce growth retardation and to impair bone metabolism. The objective of the study was to determine whether Se from pinto beans (SeBean) is as bioavailable as Se from selenomethionine (SeMet) to suppor...

  12. Dietary factors that affect carotenoid bioavailability

    NARCIS (Netherlands)

    Hof, van het K.

    1999-01-01

    Carotenoids are thought to contribute to the beneficial effects of increased vegetable consumption. To better understand the potential benefits of carotenoids, we investigated the bioavailability of carotenoids from vegetables and dietary factors which might influence carotenoid bioavailability.In a

  13. Dietary Selenium and Whole Blood Selenium in Young Women in Iceland

    OpenAIRE

    Edda Ýr Guðmundsdóttir 1969

    2011-01-01

    Background: Selenium is essential for life, and in adequate amount it is required for optimal human health. Environmental conditions and agricultural practices greatly affect selenium content of foods. Nutritional bioavailability of selenium depends on the concentration and chemical forms ingested. The National Food Composition Database is an important tool in estimating intake of minerals, such as selenium, and needs regular updates with respect to selenium content of foods. Significant chan...

  14. Hemicellulose does not affect iron bioavailability in chicks.

    Science.gov (United States)

    Fly, A D; Czarnecki-Maulden, G L; Fahey, G C; Titgemeyer, E C

    1996-01-01

    Two iron repletion experiments using hemoglobin as a response criterion were conducted to assess effects of hemicelluloses on iron bioavailability to chicks. In Experiment 1, iron bioavailability from intact fiber sources was determined by adding tomato pomace (14.6% hemicelluloses), soybean hulls (20.6% hemicelluloses), beet pulp (21.5% hemicelluloses), orchard grass (24.1% hemicelluloses) and corn fiber (55.2% hemicelluloses) to a casein dextrose basal diet providing 0.4-4.1% hemicelluloses to the diet. Test foods were analyzed for iron, total dietary fiber, neutral detergent residue, neutral detergent fiber, acid detergent fiber, acid detergent lignin, pectins and uronic acids. Hemicelluloses were determined by the difference of neutral detergent residue minus acid detergent fiber. Iron bioavailability was determined by the standard curve method to be (percent relative to ferrous sulfate using hemoglobin as the response criterion) as follows: tomato pomace, 82.0; soybean hulls, 94.0; beet pulp, 26.5; orchard grass, 68.9; corn fiber, 69.4. Iron bioavailability was not related to hemicellulose content of test foods or diets. In Experiment 2, the effect of psyllium husk (a fiber source that contains predominantly hemicelluloses) on iron bioavailability from ferrous sulfate was assessed. Bioavailability was determined by the slope ratio method where treatments consisted of graded levels of ferrous sulfate in the presence and absence of 5% dietary psyllium. Although iron intrinsic to psyllium was unavailable, bioavailability of ferrous sulfate iron was not affected (P > 0.05) by the presence of psyllium. Thus, there was no clear effect of hemicelluloses on iron bioavailability. However, some feeds that contained high levels of hemicelluloses had low intrinsic iron bioavailabilities, suggesting that other dietary factors are primarily responsible for determining iron bioavailability from these feed components. PMID:8558316

  15. Effects of aging on the fraction distribution and bioavailability of selenium in three different soils.

    Science.gov (United States)

    Li, Jun; Peng, Qin; Liang, Dongli; Liang, Sijie; Chen, Juan; Sun, Huan; Li, Shuqi; Lei, Penghui

    2016-02-01

    Aging refers to the processes by which the mobility and bioavailability of metals in soil decline with time. Although long-term aging is a key process that needs to be considered in risk assessment of metals, few investigations has been attempted to determine whether and how residence time influences the selenium (Se) fractions and bioavailability in soil. In this study, the fractions of Se in soils was evaluated, and bioavailability were assessed by measuring Se concentration in pak choi (Brassica chinensis L.). Results showed that the change of soil available Se in all tested soils divided into two phases: rapid decrease at the initial time (42 d) and slow decline thereafter. The second-order equation could describe the decrease processes of available Se in tested soils during the entire incubation time (R(2) > 0.99), while parabolic diffusion equation had less goodness of fit. Those results indicated that Se aging was controlled not only by diffusion process but also by other processes such as nucleation/precipitation, adsorption/desorption with soil component, occlusion by organic matter and reduction reaction. Soil available Se fractions tended to transform to more stable fractions during aging. The changes of Se concentration in pak choi were consistent with the variation in soil available Se content. In addition, 21 d could be reference for the time of Se aging reaching stabilization in krasnozems and fluvo-aquic soil, and 30 d for black soil. Results could provide theoretical basis to formulate environmental quality criterion and choose the equilibrium time before implementing a pot experiment in Se-spiked soils. PMID:26606190

  16. Bioavailable nanoparticles obtained in laser ablation of a selenium target in water

    International Nuclear Information System (INIS)

    The process of producing colloidal solutions of selenium nanoparticles in water using the laser ablation method is described. The prospects of using nanoparticles of elementary selenium as a nutrition source of this microelement are discussed. (nanoparticles)

  17. Chemical and biological factors affecting bioavailability of contaminants in seawater

    International Nuclear Information System (INIS)

    This paper discusses the influence that salinity has on the bioavailability of the two largest classes of contaminants, trace metals and organic compounds will be discussed. Although data on contaminant toxicity will be used to draw inferences about chemical availability, this discussion will focus on the properties that contaminants are likely to exhibit in waters of varying salinities. In addition, information on physiological changes that are affected by salinity will be used to illustrate how biological effects can alter the apparent availability of contaminants

  18. SPECIATION OF SELENIUM COMPOUNDS FROM HIGH SELENIUM BROCCOLI IS AFFECTED BY THE EXTRACTING SOLUTION

    Science.gov (United States)

    The speciation of selenium compounds from high selenium broccoli (876 ¿g/g) depends on the extraction conditions. Twenty-seven extraction conditions were explored involving nine different buffering systems between pH 1 and pH 9. In non-buffered extractions of broccoli, more than 40% of the spiked ...

  19. Mineralogy affects geoavailability, bioaccessibility and bioavailability of zinc

    International Nuclear Information System (INIS)

    We correlated mineralogical and particle characteristics of Zn-containing particles with Zn geoavailability, bioaccessibility, and bioavailability following gavage and intranasal (IN) administration in rats. We compared samples of Zn/Pb mine waste and five pulverized pure-phase Zn minerals (65Zn. We assessed geoavailability using sequential extractions and bioaccessibility using in vitro extraction tests simulating various pH and biological conditions. Zn in vivo bioavailability and in vitro bioaccessibility decreased as follows: mine waste > hydrozincite > hemimorphite > zincite ≈ smithsonite >> sphalerite. We found significant correlations among geoavailability, bioaccessibility and bioavailability. In particular, Zn bioavailability post-gavage and post-IN was significantly correlated with bioaccessibility in simulated phagolysosomal fluid and gastric fluid. These data indicate that solid phase speciation influences biological uptake of Zn and that in vitro tests can be used to predict Zn bioavailability in exposure assessment and effective remediation design. Highlights: •Zinc particle mineralogy influences bioaccessibility and bioavailability. •Zn bioavailability via gavage was 1.2–1.6 times higher than via intranasal route. •Zn particle geoavailability correlates with bioaccessibility. •In vitro bioaccessibility tests can predict in vivo Zn bioavailability. •Metal speciation and geochemical alterations can impact Zn bioavailability. -- Zinc mineralogy influences in vitro bioaccessibility and in vivo bioavailability and in vitro extraction tests can be used to predict Zn bioavailability from particles

  20. Mineralogy affects geoavailability, bioaccessibility and bioavailability of zinc

    OpenAIRE

    Molina, Ramon M.; Schaider, Laurel A.; Donaghey, Thomas C; Shine, James P.; Brain, Joseph D

    2013-01-01

    We correlated mineralogical and particle characteristics of Zn-containing particles with Zn geoavailability, bioaccessibility, and bioavailability following gavage and intranasal (IN) administration in rats. We compared samples of Zn/Pb mine waste and five pulverized pure-phase Zn minerals ( hydrozincite > hemimorphite > zincite ≈ smithsonite ≫ sphalerite. We found significant correlations among geoavailability, bioaccessibility and bioavailability. In particular, Zn bioavailability post-gava...

  1. Dietary factors that affect the bioavailability of carotenoids

    NARCIS (Netherlands)

    Hof, van het K.H.; West, C.E.; Weststrate, J.A.; Hautvast, J.G.A.J.

    2000-01-01

    Carotenoids are thought to contribute to the beneficial effects of increased vegetable consumption. Various dietary factors have an effect on the bioavailability of carotenoids. The type of food matrix in which carotenoids are located is a major factor. The bioavailability of ß-carotene from vegetab

  2. Iron, zinc and selenium status of urban and rural populations in Pakistan, their bioavailability in the diet and their dietary interaction

    International Nuclear Information System (INIS)

    In spite of the diversity of diet for rural and urban populations of Pakistan, anemias are very common. This paper contains a discussion of deficiencies of iron, zinc, selenium and magnesium in the population. Included are discussions on the bioavailability of these elements from the local diet, the various dietary interactions with other elements, and several methods used for identifying the trace element in blood samples from a test group. 28 refs, 7 tabs

  3. BLOOD SELENIUM CONCENTRATION AFFECT MASTITIS AND MILK QUALITY IN DAIRY COWS

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    Davidov Ivana

    2013-02-01

    Full Text Available Milk quality is usually defined in terms of mastitis. Milk with somatic cell count low then 400.000/ml and visibly normal (no clots is considered high quality. Thirty Holstein cows were used in the study to determine affect blood serum selenium concentration on mastitis and milk quality. Cows received ad libitum access to potable water and daily 0.3 mg/kg inorganic selenium supplementation in food. Blood and milk samples were taken at first and sixth lactating month. Mean selenium blood serum concentrations were found to be lower within first lactating month, and then increased in the sixth lactating month. Average somatic cell count at first lactating month was 450.000/ml of milk and at sixth lactating month was 355.000/ml. On the basis of these results it can be conclude that selenium have importance in proper functioning of the mammary glands of cows, and in reducing mastitis and in improving milk quality.

  4. Biological selenium removal from wastewaters

    NARCIS (Netherlands)

    Lenz, M.

    2008-01-01

    In this thesis, microbial conversion of water-soluble, highly toxic forms of selenium (selenate, selenite) to less bioavailable elemental selenium was investigated. By the exploitation of different groups of microorganisms (selenium-respiring, nitrate-reducing and sulfate-reducing bacteria, methanog

  5. Impact of heat treatment on size, structure, and bioactivity of elemental selenium nanoparticles

    Directory of Open Access Journals (Sweden)

    Wan X

    2012-02-01

    Full Text Available Jinsong Zhang1, Ethan W Taylor2, Xiaochun Wan1, Dungeng Peng31School of Tea and Food Science, Anhui Agricultural University, Anhui, People's Republic of China; 2Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC, 3Department of Biochemistry, Vanderbilt University, Nashville, TN, USABackground: Elemental selenium nanoparticles have emerged as a novel selenium source with the advantage of reduced risk of selenium toxicity. The present work investigated whether heat treatment affects the size, structure, and bioactivity of selenium nanoparticles.Methods and results: After a one-hour incubation of solution containing 80 nm selenium particles in a 90°C water bath, the nanoparticles aggregated into larger 110 nm particles and nanorods (290 nm × 70 nm, leading to significantly reduced bioavailability and phase II enzyme induction in selenium-deficient mice. When a solution containing 40 nm selenium nanoparticles was treated under the same conditions, the nanoparticles aggregated into larger 72 nm particles but did not transform into nanorods, demonstrating that the thermostability of selenium nanoparticles is size-dependent, smaller selenium nanoparticles being more resistant than larger selenium nanoparticles to transformation into nanorods during heat treatment.Conclusion: The present results suggest that temperature and duration of the heat process, as well as the original nanoparticle size, should be carefully selected when a solution containing selenium nanoparticles is added to functional foods.Keywords: nanoparticle, selenium, bioactivity, heat treatment

  6. Pro198Leu polymorphism affects the selenium status and GPx activity in response to Brazil nut intake.

    Science.gov (United States)

    Cardoso, Bárbara R; Busse, Alexandre L; Hare, Dominic J; Cominetti, Cristiane; Horst, Maria A; McColl, Gawain; Magaldi, Regina M; Jacob-Filho, Wilson; Cozzolino, Silvia M F

    2016-02-01

    Selenoproteins play important roles in antioxidant mechanisms, and are thus hypothesised to have some involvement in the pathology of certain types of dementia. Mild cognitive impairment (MCI) and Alzheimer's disease (AD) are both thought to involve impaired biological activity of certain selenoproteins. Previously, supplementation with a selenium-rich Brazil nut (Bertholletia excelsa) has shown potential in reducing cognitive decline in MCI patients, and could prove to be a safe and effective nutritional approach early in the disease process to slow decline. Here, we have conducted a pilot study that examined the effects of a range of single nucleotide polymorphisms (SNPs) in genes encoding the selenoproteins glutathione peroxidase (GPX1) and selenoprotein P (SEPP) in response to selenium supplementation via dietary Brazil nuts, including selenium status, oxidative stress parameters and GPX1 and SEPP gene expression. Our data suggest that GPX1 Pro198Leu rs1050450 genotypes may differentially affect the selenium status and GPx activity. Moreover, rs7579 and rs3877899 SNPs in SEPP gene, as well as GPX1 rs1050450 genotypes can influence the expression of GPX1 and SEPP mRNA in response to Brazil nuts intake. This small study gives cause for larger investigations into the role of these SNPs in both the selenium status and response to selenium dietary intake, especially in chronic degenerative conditions like MCI and AD. PMID:26661784

  7. Biological selenium removal from wastewaters

    OpenAIRE

    Lenz, M.

    2008-01-01

    In this thesis, microbial conversion of water-soluble, highly toxic forms of selenium (selenate, selenite) to less bioavailable elemental selenium was investigated. By the exploitation of different groups of microorganisms (selenium-respiring, nitrate-reducing and sulfate-reducing bacteria, methanogenic archaea) the operational window of conventional and new hybrid anaerobic bioreactors treating selenium containing anthropogenic waste streams has been determined. A special focus was given to ...

  8. In vitro selenium accessibility in pet foods is affected by diet composition and type.

    Science.gov (United States)

    van Zelst, Mariëlle; Hesta, Myriam; Alexander, Lucille G; Gray, Kerry; Bosch, Guido; Hendriks, Wouter H; Du Laing, Gijs; De Meulenaer, Bruno; Goethals, Klara; Janssens, Geert P J

    2015-06-28

    Se bioavailability in commercial pet foods has been shown to be highly variable. The aim of the present study was to identify dietary factors associated with in vitro accessibility of Se (Se Aiv) in pet foods. Se Aiv is defined as the percentage of Se from the diet that is potentially available for absorption after in vitro digestion. Sixty-two diets (dog, n 52; cat, n 10) were in vitro enzymatically digested: fifty-four of them were commercially available (kibble, n 20; pellet, n 8; canned, n 17; raw meat, n 6; steamed meat, n 3) and eight were unprocessed (kibble, n 4; canned, n 4) from the same batch as the corresponding processed diets. The present investigation examined if Se Aiv was affected by diet type, dietary protein, methionine, cysteine, lysine and Se content, DM, organic matter and crude protein (CP) digestibility. Se Aiv differed significantly among diet types (Pextrusion (n 4) revealed no effect on Se Aiv (P =0·297). These differences in Se Aiv between diet types warrant quantification of diet type effects on in vivo Se bioavailability. PMID:25994047

  9. Assessment of intake of iron and nutrients that affect bioavailability of daily food rations of girls

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    Anna Broniecka

    2014-06-01

    Full Text Available INTRODUCTION AND AIM In a human body iron occurs at a level of 3 to 5 g, 60-70 % of which are in hemoglobin, ca. 10% in myoglobin, and ca. 3% are accumulated in enzymes of cellular respiration or enzymes degrading toxic hydrogen peroxide. The other part of iron is accumulated in liver, spleen, kidneys and bone marrow. The dietary deficiency of iron appears at its insufficient level in a diet and at impaired absorption of iron ions present in food products by a body. Groups at an especially high risk of iron deficiencies include, among others, menstruating girls in the pubescence period and women with heavy and irregular menstruations, as well as vegetarians and patients with chronic enteritis. The aim of this study was to evaluate the intake of iron and nutrients that affect its bioavailability from daily food rations of girls. MATERIAL AND METHODS The study included 159 girls aged 17-18, students of high schools in the city of Wroclaw. The study was conducted between November 2010 and ay 2011. Girls were divided into 3 subgroups according to the BMI score. Girls’ diets were analyzed with the method of a direct interview of the last 24 hours before the test and the interview was repeated seven times. RESULTS The present study demonstrated that the intake of iron from food rations of almost all the girls surveyed was below the requirements defined for this age group. Statistically significant differences were noted in the intake of energy and nutrients among the three distinguished subgroups of girls. CONCLUSIONS Food rations of the surveyed girls were characterized by a low, compared to dietary allowances, calorific value, which resulted in deficiencies of nutrients increasing iron bioavailability.

  10. Caddisflies as biomonitors identifying thresholds of toxic metal bioavailability that affect the stream benthos

    International Nuclear Information System (INIS)

    It has been proposed that bioaccumulated concentrations of toxic metals in tolerant biomonitors be used as indicators of metal bioavailability that could be calibrated against the ecological response to metals of sensitive biotic assemblages. Our hypothesis was that metal concentrations in caddisfly larvae Hydropsyche siltalai and Plectrocnemia conspersa, as tolerant biomonitors, indicate metal bioavailability in contaminated streams, and can be calibrated against metal-specific ecological responses of mayflies. Bioaccumulated concentrations of Cu, As, Zn and Pb in H. siltalai from SW English streams were related to the mayfly assemblage. Mayflies were always sparse where bioavailabilities were high and were abundant and diverse where bioavailabilities of all metals were low, a pattern particularly evident when the combined abundance of heptageniid and ephemerellid mayflies was the response variable. The results offer promise that bioaccumulated concentrations of metals in tolerant biomonitors can be used to diagnose ecological impacts on stream benthos from metal stressors. - Highlights: ► Metal concentrations in caddisfly larvae can be calibrated against mayfly ecological responses. ► Cu, As, Zn and Pb concentrations in Hydropsyche siltalai were related to stream mayfly assemblages. ► Mayflies were sparse in high metal bioavailabilities, and abundant in low bioavailabilities. ► Joint heptageniid and ephemerellid mayfly abundance was the most sensitive response variable. ► Copper, arsenic and, in one catchment, lead were the primary stressors limiting mayfly abundance. - Accumulated metal concentrations in tolerant biomonitors can be used to detect and diagnose ecological impacts on freshwater stream benthos from metal stressors.

  11. Streamflow and water-quality conditions including geologic sources and processes affecting selenium loading in the Toll Gate Creek watershed, Aurora, Arapahoe County, Colorado, 2007

    Science.gov (United States)

    Paschke, Suzanne S.; Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.; Schaffrath, Keelin R.

    2013-01-01

    Toll Gate Creek is a perennial stream draining a suburban area in Aurora, Colorado, where selenium concentrations have consistently exceeded the State of Colorado aquatic-life standard for selenium of 4.6 micrograms per liter since the early 2000s. In cooperation with the City of Aurora, Colorado, Utilities Department, a synoptic water-quality study was performed along an 18-kilometer reach of Toll Gate Creek extending from downstream from Quincy Reservoir to the confluence with Sand Creek to develop a detailed understanding of streamflow and concentrations and loads of selenium in Toll Gate Creek. Streamflow and surface-water quality were characterized for summer low-flow conditions (July–August 2007) using four spatially overlapping synoptic-sampling subreaches. Mass-balance methods were applied to the synoptic-sampling and tracer-injection results to estimate streamflow and develop spatial profiles of concentration and load for selenium and other chemical constituents in Toll Gate Creek surface water. Concurrent groundwater sampling determined concentrations of selenium and other chemical constituents in groundwater in areas surrounding the Toll Gate Creek study reaches. Multivariate principal-component analysis was used to group samples and to suggest common sources for dissolved selenium and major ions. Hydrogen and oxygen stable-isotope ratios, groundwater-age interpretations, and chemical analysis of water-soluble paste extractions from core samples are presented, and interpretation of the hydrologic and geochemical data support conclusions regarding geologic sources of selenium and the processes affecting selenium loading in the Toll Gate Creek watershed. Streamflow conditions observed and measured during the synoptic water-quality study represent summer base-flow conditions and rainfall conditions for July 2007. The lack of large tributary inflows and the spatial distribution of small tributary inflows, seeps, and springs indicate that diffuse and

  12. Oral bioavailability of heavy metals and organic compounds from soil ; too complicated to absorb? An inventarisation of factors affecting bioavailability of environmental contaminants from soil

    OpenAIRE

    Sips AJAM; van Eijkeren JCH.; LBO

    1996-01-01

    Bioavailability plays an important role in risk assessment of environmental contaminants from soil. It is one of the determinants in the assessment of intervention values. In present risk assessment, bioavailability from soil is supposed to be 100% due to a paucity of reliable information. However, when it should appear that in this model bioavailability is overestimated by a factor 2 or more, this would imply that the present intervention values are 50% or more too low. This report gives an ...

  13. Biofortification and bioavailability of rice grain zinc as affected by different forms of foliar zinc fertilization.

    Directory of Open Access Journals (Sweden)

    Yanyan Wei

    Full Text Available BACKGROUND: Zinc (Zn biofortification through foliar Zn application is an attractive strategy to reduce human Zn deficiency. However, little is known about the biofortification efficiency and bioavailability of rice grain from different forms of foliar Zn fertilizers. METHODOLOGY/PRINCIPAL FINDINGS: Four different Zn forms were applied as a foliar treatment among three rice cultivars under field trial. Zinc bioavailability was assessed by in vitro digestion/Caco-2 cell model. Foliar Zn fertilization was an effective agronomic practice to promote grain Zn concentration and Zn bioavailability among three rice cultivars, especially, in case of Zn-amino acid and ZnSO(4. On average, Zn-amino acid and ZnSO(4 increased Zn concentration in polished rice up to 24.04% and 22.47%, respectively. On average, Zn-amino acid and ZnSO(4 increased Zn bioavailability in polished rice up to 68.37% and 64.43%, respectively. The effectiveness of foliar applied Zn-amino acid and ZnSO(4 were higher than Zn-EDTA and Zn-Citrate on improvement of Zn concentration, and reduction of phytic acid, as a results higher accumulation of bioavailable Zn in polished rice. Moreover, foliar Zn application could maintain grain yield, the protein and minerals (Fe and Ca quality of the polished rice. CONCLUSIONS: Foliar application of Zn in rice offers a practical and useful approach to improve bioavailable Zn in polished rice. According to current study, Zn-amino acid and ZnSO(4 are recommended as excellent foliar Zn forms to ongoing agronomic biofortification.

  14. Soil sterilization affects aging-related sequestration and bioavailability of p,p'-DDE and anthracene to earthworms

    International Nuclear Information System (INIS)

    Laboratory experiments investigated the effects of soil sterilization and compound aging on the bioaccumulation of spiked p,p'-DDE and anthracene by Eisenia fetida and Lumbricus terrestris. Declines in bioavailability occurred as pollutant residence time in both sterile and non-sterile soils increased from 3 to 203 d. Accumulation was generally higher in sterile soils during initial periods of aging (from 3-103 d). By 203 d, however, bioavailability of the compounds was unaffected by sterilization. Gamma irradiation and autoclaving may have altered bioavailability by inducing changes in the chemistry of soil organic matter (SOM). The results support a dual-mode partitioning sorption model in which the SOM components associated with short-term sorption (the 'soft' or 'rubbery' phases) are more affected than are the components associated with long-term sorption (the 'glassy' or microcrystalline phases). Risk assessments based on data from experiments in which sterile soil was used could overestimate exposure and bioaccumulation of pollutants. - Soil sterilization affects aging-related sequestration of organic contaminants.

  15. SUPPLEMENTAL DIETARY INULIN AFFECTS BIOAVAILABILITY OF IRON PRESENT IN CORN AND SOYBEAN MEAL TO YOUNG PIGS

    Science.gov (United States)

    Iron deficiency represents one of the most common global nutritional disorders in humans. Our objective was to determine whether and how supplemental inulin improved bioavailability of iron intrinsically present in a corn-soybean meal based diet to young pigs for hemoglobin synthesis. In Experimen...

  16. In vitro selenium accessibility in pet foods is affected by diet composition and type

    NARCIS (Netherlands)

    van Zelst, Mariëlle; Hesta, Myriam; Alexander, Lucille G; Gray, Kerry; Bosch, Guido; Hendriks, Wouter H; Du Laing, Gijs; De Meulenaer, Bruno; Goethals, Klara; Janssens, Geert P J

    2015-01-01

    Se bioavailability in commercial pet foods has been shown to be highly variable. The aim of the present study was to identify dietary factors associated with in vitro accessibility of Se (Se Aiv) in pet foods. Se Aiv is defined as the percentage of Se from the diet that is potentially available for

  17. Selenium bioaccessibility and speciation in biofortified Pleurotus mushrooms grown on selenium-rich agricultural residues.

    Science.gov (United States)

    Bhatia, Poonam; Aureli, Federica; D'Amato, Marilena; Prakash, Ranjana; Cameotra, Swaranjit Singh; Nagaraja, Tejo Prakash; Cubadda, Francesco

    2013-09-01

    Cultivation of saprophytic fungi on selenium-rich substrates can be an effective means to produce selenium-fortified food. Pleurotus florida, an edible species of oyster mushrooms, was grown on wheat straw from the seleniferous belt of Punjab (India) and its potential to mobilize and accumulate selenium from the growth substrate was studied. Selenium concentration in biofortified mushrooms was 800 times higher compared with control samples grown on wheat straw from non selenium-rich areas (141 vs 0.17 μg Se g(-1) dry weight). Seventy-five percent of the selenium was extracted after in vitro simulated gastrointestinal digestion and investigation of the selenium molecular fractions by size exclusion HPLC-ICP-MS revealed that proteins and any other high molecular weight selenium-containing molecule were hydrolyzed to peptides and low molecular weight selenocompounds. Analysis of the gastrointestinal hydrolysates by anion exchange HPLC-ICP-MS showed that the bioaccessible selenium was mainly present as selenomethionine, a good bioavailable source of selenium, which accounted for 73% of the sum of the detected species. This study demonstrates the feasibility of producing selenium-biofortified edible mushrooms using selenium-rich agricultural by-products as growth substrates. The proposed approach can be used to evaluate whether selenium-contaminated plant waste materials harvested from high-selenium areas may be used to produce selenium-biofortified edible mushrooms based on the concentration, bioaccessibility and speciation of selenium in the mushrooms. PMID:23578637

  18. Investigation of stillbirths, perinatal mortality and weakness in beef calves with low-selenium whole blood concentrations.

    Science.gov (United States)

    Davis, Anthony J; Myburgh, Jan G

    2016-01-01

    In this on-farm investigation, we report on stillbirths, weakness and perinatal mortality seen in calves on a commercial beef farm in the Roossenekal area, Mpumalanga province, South Africa. Post-mortem examination of these calves and histopathological examination of organ and tissue samples did not indicate an infectious aetiology. Affected calves had marginal to deficient whole blood selenium concentrations. Whole blood samples collected from adult cattle on this farm and five neighbouring farms were deficient in selenium. The potential contributions of other minerals to the symptoms seen are a subject of ongoing investigation, but selenium deficiency was marked in this herd and required urgent correction. Methods to correct the deficiency included the use of injectable products, and an oral selenium supplement chelated to methionine. Selenium availability to plants is primarily determined by the selenium content of the parent bedrock, the presence of other minerals and the pH of the soil. The apparent sudden onset of this problem implicates a soil factor as being responsible for reducing selenium's bioavailability in this area. Selenium deficiency can have a significant impact on human health. HIV and/or AIDS, various forms of cancer and several specific clinical syndromes are associated with selenium deficiency in humans, and the impact on human health in this area also requires further investigation. PMID:27543038

  19. Investigation of stillbirths, perinatal mortality and weakness in beef calves with low-selenium whole blood concentrations

    Directory of Open Access Journals (Sweden)

    Anthony J. Davis

    2016-02-01

    Full Text Available In this on-farm investigation, we report on stillbirths, weakness and perinatal mortality seen in calves on a commercial beef farm in the Roossenekal area, Mpumalanga province, South Africa. Post-mortem examination of these calves and histopathological examination of organ and tissue samples did not indicate an infectious aetiology. Affected calves had marginal to deficient whole blood selenium concentrations. Whole blood samples collected from adult cattle on this farm and five neighbouring farms were deficient in selenium. The potential contributions of other minerals to the symptoms seen are a subject of ongoing investigation, but selenium deficiency was marked in this herd and required urgent correction. Methods to correct the deficiency included the use of injectable products, and an oral selenium supplement chelated to methionine. Selenium availability to plants is primarily determined by the selenium content of the parent bedrock, the presence of other minerals and the pH of the soil. The apparent sudden onset of this problem implicates a soil factor as being responsible for reducing selenium’s bioavailability in this area. Selenium deficiency can have a significant impact on human health. HIV and/or AIDS, various forms of cancer and several specific clinical syndromes are associated with selenium deficiency in humans, and the impact on human health in this area also requires further investigation.Keywords: vitamin E; selenium deficiency; cattle; one-health; Mpumalanga Province; soil pH; acid rain; stillbirths; white muscle disease; HIV

  20. Interaction of phytic acid and zinc affecting copper bioavailability in rats

    International Nuclear Information System (INIS)

    The objectives of this investigation were to develop a protocol to measure Cu bioavailability using four different indices of Cu status, and to evaluate the effect of phytic acid on Cu bioavailability using these indices in the rat. Ninety-six Sprague-Dawley male weanling rats were fed a Cu-deficient diet for four weeks. The Cu-depleted rats were divided into twelve groups and fed test diets containing 1, 2, 3, and 10 ug Cu and 0, 0.4 and 0.8% phytic acid at each Cu level. After 3 days of Cu repletion, liver copper (LCu), liver superoxide dismutase (LSOD) activity, serum copper (SCu), and serum ceruloplasmin (CP) were measured. There was a significant decrease in SCu and LCu in rats fed 30 ug Zn/g or 230 ug Zn/g compared to animals fed 12 ug Zn/g. Phytic acid increased the level of Cu in the sera and livers of rats fed the diet with 30 ug Zn/g, but those of rats fed 12 or 230 ug Zn/g did not. Dietary phytic acid appeared to reduce the synthesis of two intestinal proteins: a high molecular weight protein and metallothionein. The incorporation of 35S-cysteine into both proteins increased with increasing levels of dietary Zn. The results of these studied indicated: (1) LCu and SCu are reliable indices of Cu for absorption and utilization in the rat, and (2) phytic acid increases Cu bioavailability by binding dietary Zn and reduces the level of Zn-induced mucosal proteins which allows Cu to be more efficiently absorbed

  1. Bioavailability of zinc and phosphorus in calcareous soils as affected by citrate exudation

    OpenAIRE

    Duffner, A.; Hoffland, E.; Temminghoff, E.J.M.

    2012-01-01

    Aims Zinc (Zn) and phosphorus (P) deficiency often occurs at the same time and limits crop production in many soils. It has been suggested that citrate root exudation is a response of plants to both deficiencies. We used white lupin (Lupinus albus L.) as a model plant to clarify if citrate exuded by roots could increase the bioavailability of Zn and P in calcareous soils. Methods White lupin was grown in nutrient solution and in two calcareous soils in a rhizobox. Rhizosphere soil solution wa...

  2. Kolliphor surfactants affect solubilization and bioavailability of fenofibrate. Studies of in vitro digestion and absorption in rats

    DEFF Research Database (Denmark)

    Berthelsen, Ragna; Holm, Rene; Jacobsen, Jette;

    2015-01-01

    Selection of excipients for drug formulations requires both intellectual and experimental considerations as many of the used excipients are affected by physiological factors, e.g., they may be digested by pancreatic enzymes in the gastrointestinal tract. In the present paper we have looked...... fenofibrate absorption optimum was seen at 15% (w/v) surfactant, displaying both the highest AUC0–24h and Cmax. The reduced absorption of fenofibrate from the formulation containing the highest level of surfactant (25% w/v) was thought to be caused by some degree of trapping within Kolliphor RH40 micelles. In...... vitro, Kolliphor ELP and EL were found to be more prone to digestion than Kolliphor RH40, though not affecting the in vivo results. The highest fenofibrate bioavailability was attained from formulations with high Kolliphor ELP/EL levels (25% (w/v)), indicating that these surfactants are the better...

  3. Have the bioavailabilities of trace metals to a suite of biomonitors changed over three decades in SW England estuaries historically affected by mining?

    Science.gov (United States)

    Rainbow, P S; Kriefman, S; Smith, B D; Luoma, S N

    2011-03-15

    Many estuaries of southwest England were heavily contaminated with toxic metals associated with the mining of copper and other metals, particularly between 1850 and 1900. The question remains whether the passage of time has brought remediation to these estuaries. In 2003 and 2006 we revisited sites in 5 metal-contaminated estuaries sampled in the 1970s and 1980s - Restronguet Creek, Gannel, West Looe, East Looe and Tavy. We evaluate changes in metal contamination in sediments and in metal bioavailabilities in sediments and water to local organisms employed as biomonitors. We find that the decline in contamination in these estuaries is complex. Differences in bioavailable contamination in the water column were detectable, as were significant detectable changes in at least some estuaries in bioavailable metal contamination originating from sediments. However, in the 100 years since mining activities declined, bioavailable contamination has not declined to the regional baseline in any estuary affected by the mine wastes. The greatest decline in contamination occurred in the one instance (East Looe) where a previous industrial source of (Ag) contamination was considered. We used the macroalgae Fucus vesiculosus and Ascophyllum nodosum as biomonitors of dissolved metal bioavailabilities and the deposit feeders Nereis diversicolor and Scrobicularia plana as biomonitors of bioavailable metal in sediments. We found no systematic decrease in the atypically high Ag, Cu, Pb and Zn concentrations in the estuarine sediments over a 26 year period. Accumulated metal (Ag, As, Cu, Pb, and Zn) concentrations in the deposit feeders are similarly still atypically high in at least one estuary for each metal, and there is no consistent evidence for general decreases in sediment metal bioavailabilities over time. We conclude that the legacy of mining in sheltered estuaries of southwest England is the ongoing presence of sediments rich in metals bioavailable to deposit feeders, while

  4. Soy protein isolate does not affect ellagitannin bioavailability and urolithin formation when mixed with pomegranate juice in humans.

    Science.gov (United States)

    Yang, Jieping; Lee, Rupo; Henning, Susanne M; Thames, Gail; Hsu, Mark; ManLam, Hei; Heber, David; Li, Zhaoping

    2016-03-01

    We investigated the effect of mixing soy protein isolate and pomegranate juice (PJ) on the bioavailability and metabolism of ellagitannins (ETs) in healthy volunteers. Eighteen healthy volunteers consumed PJ alone or PJ premixed with soy protein isolate (PJSP). The concentration of plasma ellagic acid (EA) and urine urolithins was measured. There was no significant difference in plasma EA over a 6-h period between the two interventions. While the maximum concentration of plasma EA after PJSP consumption was slightly but significantly lower than after PJ consumption, EA remained in the plasma longer with an elimination half-life t1/2E at 1.36±0.59 versus 1.06±0.47h for PJSP and PJ consumption, respectively. Urinary urolithin A, B and C was not significantly different between the two interventions. In conclusion, premixing soy protein isolate and PJ did not affect the bioavailability or the metabolism of pomegranate ETs in healthy volunteers. PMID:26471685

  5. Characterisation and modelling of mercury speciation in urban air affected by gold mining - assessment of bioavailability

    Directory of Open Access Journals (Sweden)

    Cukrowska E. M.

    2013-04-01

    Full Text Available The growing global concern over the release of mercury to the environment has prompted specific inventories that quantify mercury emissions from various sources. Investigations of atmospheric mercury have been mostly done on gaseous species. Although, to assess human expose to mercury, especially in urban areas, the inhalable dust should be included in a study. The Witwatersrand Basin in South Africa is one of the most important gold mining regions in the world. Mercury (Hg, which occurs in gold-bearing ores, was also used for gold recoveries in previous centuries (19th and early 20th century and presently in illegal artisanal mining. The consequences of these mining activities were the release of Hg to the environment, mainly due to AMD from tailings dumps which are presently reprocessed. The city of Johannesburg is a multimillion population exposed strongly to industrial pollution. The aim of this study was to determine the magnitude of mercury pollution in this urban area and assess its bioavailability. The gaseous samples were collected by trapping mercury on various gold traps. Dust samples were collected from a ground and on inhalation levels (1–2 m above a ground. They were later separated into different fractions by micro sieving. Bioavailability of mercury in inhalable dust (25 μm was tested by leaching collected samples with artificial lung fluid (ALF, pH 4.5, Gray’s solution (pH 7.4 and water. The leaching conditions were selected to mimic lungs environment (incubator at 30°C, time 24 hrs, rotation of samples 150 rpm. Total concentrations of mercury in dust fractions were also determined after microwave digestion. The results showed extremely high concentration levels of mercury in air and dust in industrial areas. Especially high levels were found around presently reprocessed old gold tailings dumps, up to 900 000 μgl–1. The levels dropped significantly in CBD area but still showing elevated concentrations up to 10 μgl−1

  6. Soil Redox Chemistry Limitation of Selenium Concentration in Carex Species Sedges

    Energy Technology Data Exchange (ETDEWEB)

    Bruce J. Mincher; John Mionczynski; Patrick A. Hnilicka

    2007-09-01

    The trace element selenium (Se) is required in the production of enzymes that protect mammalian cells from oxidative damage due to the byproducts of aerobic respiration. Its deficiency in livestock results in the nutritional muscular dystrophy called white muscle disease. This especially affects juveniles in the preweaning period. Symptoms have also been reported in wild herbivores on low-Se forage, and their appearance may be episodic, suggesting temporal variations in Se uptake by plants. Here, we report variations in selenium concentrations in Carex spp. sedges used as forage by bighorn sheep (Ovis canadensis) on summer range in the Wyoming, Wind River Mountains, and correlate those variations with soil conditions that affect the bioavailability of selenium. Variations in available Se are explained based upon the known oxidation/reduction chemistry of the element. It is concluded that water-saturated, alpine soils provide conditions suitable for the reduction of Se to the unavailable, elemental form, limiting its concentration in forage plants.

  7. Heavy metal bioavailability in a soil affected by mineral sulphides contamination following the mine spillage at Aznalcóllar (Spain).

    Science.gov (United States)

    Clemente, Rafael; Walker, David J; Roig, Asunción; Bernal, M Pilar

    2003-06-01

    A field experiment, lasting 14 months, was carried out in order to assess the effect of organic amendment and lime addition on the bioavailability of heavy metals in contaminated soils. The experiment took place in a soil affected by acid, highly toxic pyritic waste from the Aznalcóllar mine (Seville, Spain) in April 1998. The following treatments were applied (3 plots per treatment): cow manure, a mature compost, lime (to plots having pH acidification, due to the oxidation of metallic sulphides in the soil, increased heavy metal bioavailability; (2) liming succeeded in controlling the soil acidification; and (3) the organic materials generally promoted fixation of heavy metals in non-available soil fractions, with Cu bioavailability being particularly affected by the organic treatments. PMID:12889610

  8. Acute toxicity of the cationic surfactant C12-benzalkonium in different bioassays: how test design affects bioavailability and effect concentrations.

    Science.gov (United States)

    Chen, Yi; Geurts, Marc; Sjollema, Sascha B; Kramer, Nynke I; Hermens, Joop L M; Droge, Steven T J

    2014-03-01

    Using an ion-exchange-based solid-phase microextraction (SPME) method, the freely dissolved concentrations of C12-benzalkonium were measured in different toxicity assays, including 1) immobilization of Daphnia magna in the presence or absence of dissolved humic acid; 2) mortality of Lumbriculus variegatus in the presence or absence of a suspension of Organisation for Economic Co-Operation and Development (OECD) sediment; 3) photosystem II inhibition of green algae Chlorella vulgaris; and 4) viability of in vitro rainbow trout gill cell line (RTgill-W1) in the presence or absence of serum proteins. Furthermore, the loss from chemical adsorption to the different test vessels used in these tests was also determined. The C12-benzalkonium sorption isotherms to the different sorbent phases were established as well. Our results show that the freely dissolved concentration is a better indicator of the actual exposure concentration than the nominal or total concentration in most test assays. Daphnia was the most sensitive species to C12-benzalkonium. The acute Daphnia and Lumbriculus tests both showed no enhanced toxicity from possible ingestion of sorbed C12-benzalkonium in comparison with water-only exposure, which is in accordance with the equilibrium partitioning theory. Moreover, the present study demonstrates that commonly used sorbent phases can strongly affect bioavailability and observed effect concentrations for C12-benzalkonium. Even stronger effects of decreased actual exposure concentrations resulting from sorption to test vessels, cells, and sorbent phases can be expected for more hydrophobic cationic surfactants. PMID:24273010

  9. Selenium status affects selenoprotein expression, reproduction, and F₁ generation locomotor activity in zebrafish (Danio rerio).

    Science.gov (United States)

    Penglase, Sam; Hamre, Kristin; Rasinger, Josef D; Ellingsen, Staale

    2014-06-14

    Se is an essential trace element, and is incorporated into selenoproteins which play important roles in human health. Mammalian selenoprotein-coding genes are often present as paralogues in teleost fish, and it is unclear whether the expression patterns or functions of these fish paralogues reflect their mammalian orthologues. Using the model species zebrafish (Danio rerio; ZF), we aimed to assess how dietary Se affects key parameters in Se metabolism and utilisation including glutathione peroxidase (GPX) activity, the mRNA expression of key Se-dependent proteins (gpx1a, gpx1b, sepp1a and sepp1b), oxidative status, reproductive success and F1 generation locomotor activity. From 27 d until 254 d post-fertilisation, ZF were fed diets with graded levels of Se ranging from deficient ( < 0·10 mg/kg) to toxic (30 mg/kg). The mRNA expression of gpx1a and gpx1b and GPX activity responded in a similar manner to changes in Se status. GPX activity and mRNA levels were lowest when dietary Se levels (0·3 mg/kg) resulted in the maximum growth of ZF, and a proposed bimodal mechanism in response to Se status below and above this dietary Se level was identified. The expression of the sepp1 paralogues differed, with only sepp1a responding to Se status. High dietary Se supplementation (30 mg/kg) decreased reproductive success, while the offspring of ZF fed above 0·3 mg Se/kg diet had lower locomotor activity than the other groups. Overall, the novel finding of low selenoprotein expression and activity coinciding with maximum body growth suggests that even small Se-induced variations in redox status may influence cellular growth rates. PMID:24666596

  10. Aging negatively affects estrogens-mediated effects on nitric oxide bioavailability by shifting ERα/ERβ balance in female mice.

    Directory of Open Access Journals (Sweden)

    Laura Novensà

    Full Text Available AIMS: Aging is among the major causes for the lack of cardiovascular protection by estrogen (E2 during postmenopause. Our study aims to determine the mechanisms whereby aging changes E2 effects on nitric oxide (NO production in a mouse model of accelerated senescence (SAM. METHODS AND RESULTS: Although we found no differences on NO production in females SAM prone (SAMP, aged compared to SAM resistant (SAMR, young, by either DAF-2 fluorescence or plasmatic nitrite/nitrate (NO2/NO3, in both cases, E2 treatment increased NO production in SAMR but had no effect in SAMP. Those results are in agreement with changes of eNOS protein and gene expression. E2 up-regulated eNOS expression in SAMR but not in SAMP. E2 is also known to increase NO by decreasing its catabolism by superoxide anion (O(2(-. Interestingly, E2 treatment decreased O(2(- production in young females, while increased O(2(- in aged ones. Furthermore, we observed that aging changed expression ratio of estrogen receptors (ERβ/ERα and levels of DNA methylation. Increased ratio ERβ/ERα in aged females is associated to a lack of estrogen modulation of NO production and with a reversal in its antioxidant effect to a pro-oxidant profile. CONCLUSIONS: Together, our data suggest that aging has detrimental effects on E2-mediated benefits on NO bioavailability, partially by affecting the ability of E2 to induce up regulation of eNOS and decrease of O(2(-. These modifications may be associated to aging-mediated modifications on global DNA methylation status, but not to a specific methylation at 5'flanking region of ERα gene.

  11. Selenium essentials

    CERN Document Server

    Sams, Prashanth

    2015-01-01

    If you are a developer who wants to migrate from Selenium RC or any other automation tool to Selenium WebDriver, then this book is for you. Knowledge of automation tools is necessary to follow the examples in this book.

  12. Bioanalytical effect-balance model to determine the bioavailability of organic contaminants in sediments affected by black and natural carbon.

    Science.gov (United States)

    Bräunig, Jennifer; Tang, Janet Y M; Warne, Michael St J; Escher, Beate I

    2016-08-01

    In sediments several binding phases dictate the fate and bioavailability of organic contaminants. Black carbon (BC) has a high sorptive capacity for organic contaminants and can limit their bioavailability, while the fraction bound to organic carbon (OC) is considered to be readily desorbable and bioavailable. We investigated the bioavailability and mixture toxicity of sediment-associated contaminants by combining different extraction techniques with in vitro bioanalytical tools. Sediments from a harbour with high fraction of BC, and sediments from remote, agricultural and urban areas with lower BC were treated with exhaustive solvent extraction, Tenax extraction and passive sampling to estimate total, bioaccessible and bioavailable fractions, respectively. The extracts were characterized with cell-based bioassays that measure dioxin-like activity (AhR-CAFLUX) and the adaptive stress response to oxidative stress (AREc32). Resulting bioanalytical equivalents, which are effect-scaled concentrations, were applied in an effect-balance model, consistent with a mass balance-partitioning model for single chemicals. Sediments containing BC had most of the bioactivity associated to the BC fraction, while the OC fraction played a role for sediments with lower BC. As effect-based sediment-water distribution ratios demonstrated, most of the bioactivity in the AhR-CAFLUX was attributable to hydrophobic chemicals while more hydrophilic chemicals activated AREc32, even though bioanalytical equivalents in the aqueous phase remained negligible. This approach can be used to understand the fate and effects of mixtures of diverse organic contaminants in sediments that would not be possible if single chemicals were targeted by chemical analysis; and make informed risk-based decisions concerning the management of contaminated sediments. PMID:27176940

  13. Micronutrient bioavailability: Dietary Reference Intakes and a future perspective1234

    OpenAIRE

    Hambidge, K. Michael

    2010-01-01

    This article provides a review of how the challenge of bioavailability was approached in establishing the Dietary Reference Intakes, with a special focus on folic acid, vitamin B-12, β-carotene, iron, selenium, and zinc, the targeted micronutrients for this workshop. In a future perspective, the necessity of having a clear working definition of bioavailability is emphasized. The bioavailability of micronutrients should be considered, with advantage, under subheadings determined by the broad f...

  14. Food matrices affect the bioavailability of (n-3) polyunsaturated fatty acids in a single meal study in humans

    DEFF Research Database (Denmark)

    Schram, Laurine B; Nielsen, Carina J.; Porsgaard, Trine;

    2007-01-01

    The aim of this study was to investigate the role of the food matrix on bioavailability of (n - 3) PUFA and oxidative stress in plasma. The study was a randomized, cross-over study and included 12 healthy male participants. The participants ingested a test meal, which consisted of a fitness bar, ......-tocopherol after ingestion of test meals. (c) 2007 Elsevier Ltd. All rights reserved....

  15. Modeling the impact of soil aggregate size on selenium immobilization

    Directory of Open Access Journals (Sweden)

    M. F. Kausch

    2012-09-01

    Full Text Available Soil aggregates are mm- to cm-sized microporous structures separated by macropores. Whereas fast advective transport prevails in macropores, advection is inhibited by the low permeability of intra-aggregate micropores. This can lead to mass transfer limitations and the formation of aggregate-scale concentration gradients affecting the distribution and transport of redox sensitive elements. Selenium (Se mobilized through irrigation of seleniferous soils has emerged as a major aquatic contaminant. In the absence of oxygen, the bioavailable oxyanions selenate, Se(VI, and selenite, Se(IV, can be microbially reduced to solid, elemental Se, Se(0, and anoxic microzones within soil aggregates are thought to promote this process in otherwise well aerated soils.

    To evaluate the impact of soil aggregate size on selenium retention, we developed a dynamic 2-D reactive transport model of selenium cycling in a single idealized aggregate surrounded by a macropore. The model was developed based on flow-through-reactor experiments involving artificial soil aggregates (diameter: 2.5 cm made of sand and containing Enterobacter cloacae SLD1a-1 that reduces Se(VI via Se(IV to Se(0. Aggregates were surrounded by a constant flow providing Se(VI and pyruvate under oxic or anoxic conditions. In the model, reactions were implemented with double-Monod rate equations coupled to the transport of pyruvate, O2, and Se-species. The spatial and temporal dynamics of the model were validated with data from experiments and predictive simulations were performed covering aggregate sizes between 1 and 2.5 cm diameter.

    Simulations predict that selenium retention scales with aggregate size. Depending on O2, Se(VI, and pyruvate concentrations, selenium retention was 4–23 times higher in 2.5-cm-aggregates compared to 1-cm-aggregates. Under oxic conditions, aggregate size and pyruvate-concentrations were found to have a positive synergistic

  16. Selenium elimination in pigs after an outbreak of selenium toxicosis.

    Science.gov (United States)

    Davidson-York, D; Galey, F D; Blanchard, P; Gardner, I A

    1999-07-01

    In May 1996, 150 grower pigs in 5 California counties were exposed to selenium-contaminated feed distributed by a single feed company. Feed samples from 20 herds had a mean selenium concentration of 121.7 ppm dry weight (range, 22.1-531 ppm). In San Luis Obispo County, 52 pigs in 24 herds were exposed to the feed, and 8 pigs died with signs of paralysis. Bilateral symmetrical poliomyelomalacia involving the ventral horns of the cervical and lumbar intumescence was evident on histologic examination of spinal cord from affected pigs. Of 44 surviving exposed pigs, 33 (75%) exhibited signs of selenosis, including anorexia, alopecia, and hoof lesions. Thirty-nine of 44 pigs (88.6%) had elevated (>1 ppm) blood selenium concentrations. Surviving exposed pigs were changed to a standard commercial ration containing approximately 0.5 ppm (dry weight) selenium. Blood selenium concentrations were determined weekly for 46 days following removal of the contaminated feed and were compared with values of 20 control pigs fed a standard commercial ration. Mean (+/-SD) blood selenium concentrations of exposed pigs were 3.2 +/- 2.6 ppm at the initial sampling and 0.4 +/- 0.1 ppm after 46 days. Mean blood selenium concentrations of Muscle and liver samples of 22 of the 44 exposed pigs were collected at slaughter approximately 72 days after withdrawal of the selenium-contaminated feed. Muscle samples had a mean selenium concentration of 0.36 ppm (wet weight). Liver samples had a mean selenium concentration of 1.26 ppm (wet weight). One liver sample had a selenium value in the toxic range for pigs (3.3 ppm wet weight; reference range, 0.4-1.2 ppm). A 1-compartment pharmacokinetic model of selenium elimination in exposed pigs was generated, and the geometric mean blood selenium elimination half-life was estimated to be 12 days. The 60-day withdrawal time recommended by the Food Animal Residue Avoidance Database was considered sufficient to allow safe human consumption of tissues from

  17. Hepatic oxidative stress and metal subcellular partitioning are affected by selenium exposure in wild yellow perch (Perca flavescens).

    Science.gov (United States)

    Ponton, Dominic E; Caron, Antoine; Hare, Landis; Campbell, Peter G C

    2016-07-01

    Yellow perch (Perca flavescens) collected from 11 lakes in the Canadian mining regions of Sudbury (Ontario) and Rouyn-Noranda (Quebec) display wide ranges in the concentrations of cadmium (Cd), nickel (Ni), selenium (Se), and thallium (Tl) in their livers. To determine if these trace elements, as well as copper (Cu) and zinc (Zn), are causing oxidative stress in these fish, we measured three biochemical indicators (glutathione (GSH), glutathione disulfide (GSSG) and thiobarbituric acid-reactive substances (TBARS)) in their livers. We observed that 44% of the yellow perch that we collected were at risk of cellular oxidative stress and lipid peroxidation. Considering all fish from all lakes, higher liver Se concentrations were coincident with both lower proportions of GSSG compared to GSH and lower concentrations of TBARS, suggesting that the essential trace-element Se acts as an antioxidant. Furthermore, fish suffering oxidative stress had higher proportions of Cd, Cu and Zn in potentially sensitive subcellular fractions (organelles and heat-denatured proteins) than did fish not suffering from stress. This result suggests that reactive oxygen species may oxidize metal-binding proteins and thereby reduce the capacity of fish to safely bind trace metals. High Cd concentrations in metal-sensitive subcellular fractions likely further exacerbate the negative effects of lower Se exposure. PMID:27131821

  18. Bioavailability in rats of metal adsorbed to soils

    International Nuclear Information System (INIS)

    The toxicity of metals to humans and animals has been well documented, however little data are available on the physiological bioavailability of metals from various soil types. These studies were designed to assess the bioavailability of sodium 75selenate (NaS), 63nickel chloride (NiCl) and 109cadmium chloride (CdCl) adsorbed to sand or clay loam in rats. Each test compound was administered in seven dose groups: Group 1 - intravenously, Group 2 and 3 - oral aqueous solution by gavage, Groups 4-7 - aqueous suspension adsorbed to each soil type by gavage. Blood was collected from the jugular vein at intervals up to 48 hours post dosing and analyzed for radio-activity. Both NiCl and CdCl were poorly adsorbed from the soils. Approximately 3% of the CdCl bound to sand and 1.5% of the NiCl bound to clay loam were absorbed into the bloodstream. Approximately 0.5% and 0.1% of the CdCl bound to sand and clay, respectively were absorbed. NaS was well absorbed following oral administration with approximately 85% of the compound bound to sand and 94% bound to clay being absorbed into the blood. Bioavailability of metals from soil appears to be primarily affected by the ionic state of the metal. Anions, such as selenium, are more mobile in an acid environment and may leach more readily from soil. Cations, such as Ni and Cd may bind to soil more tightly, thus soil type becomes a factor affecting bioavailability

  19. Charge properties of peptides derived from casein affect their bioavailability and cytoprotection against H2O2-induced oxidative stress.

    Science.gov (United States)

    Wang, Bo; Xie, Ningning; Li, Bo

    2016-04-01

    The effects of charge properties of casein peptides on absorption stability, antioxidant activity, and cytoprotection were evaluated. Alcalase hydrolysates of casein were separated into 4 fractions by cation-exchange chromatography according to charge properties. After simulated digestion and Caco-2 cell transmembrane transport, we determined the total antioxidant capacity (Trolox equivalent antioxidative capacity and oxygen radical antioxidant activity) and nitrogen content of peptide fractions to estimate available antioxidant efficacy and bioavailability (BA) of peptides. Results showed that negatively charged peptide fractions had greater BA and antioxidant activities after digestion and absorption. The peptide permeates were used to test the cytoprotective effect against H2O2-induced oxidative damage in HepG-2 cells. All peptide permeates increased cell viability, elevated catalase activity, and decreased superoxide dismutase activity. However, negatively charged peptide fractions preserved cell viability to a greater degree. Therefore, the negatively charged peptides from casein may be potential antioxidants and could be used as ingredients in functional foods and dietary supplements. PMID:26851854

  20. Bioavailable concentrations of germanium and rare earth elements in soil as affected by low molecular weight organic acids and root exudates

    Science.gov (United States)

    Wiche, Oliver; Székely, Balázs; Kummer, Nicolai-Alexeji; Heinemann, Ute; Tesch, Silke; Heilmeier, Hermann

    2014-05-01

    , lanthan, neodymium, gadolinium and erbium in the rhizosphere and therefore the enhancement of bioavailability of the mentioned elements to plants. Based on the suction cup experiment we conclude that in vertical soil profile the bioavailable germanium is heavily affected by the activity of exudates, as the complexation processes of germanium take place at the root zone and below affected by the interplay of the infiltration of citric acid solutions and the actually produced exudates. These studies have been carried out in the framework of the PhytoGerm project, financed by the Federal Ministry of Education and Research, Germany. BS contributed as an Alexander von Humboldt Research Fellow. The authors are grateful to students and laboratory assistants contributing in the field work and sample preparation.

  1. Mercury and selenium levels, and selenium:mercury molar ratios of brain, muscle and other tissues in bluefish (Pomatomus saltatrix) from New Jersey, USA

    OpenAIRE

    Burger, Joanna; Jeitner, Christian; Donio, Mark; Pittfield, Taryn; Gochfeld, Michael

    2012-01-01

    A number of contaminants affect fish health, including mercury and selenium, and the selenium: mercury molar ratio. Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for consumption of saltwater fish. Yet the relative ameliorating effects of selenium on toxicity within fish have not been examined, nor has the molar ratio in different tissues, (i.e. brain). We examined mercury and selenium levels in brain, kidney, liver, red and white musc...

  2. Absorption and retention of selenium from shrimps in man

    DEFF Research Database (Denmark)

    Bugel, S. H.; Sandstrom, B.; Larsen, Erik Huusfeldt

    2001-01-01

    This study was undertaken to evaluate the bioavailability of selenium in shrimps, a possible good source of selenium, by measurements of the absorption and retention of selenium and the effects on plasma selenium concentration and glutathione peroxidase activity. Twelve healthy young subjects (9F...... commencement of the study, after 2, 4, and 6 weeks. The selenium intake increased from 39.4 +/- 15.3 mug/d to 127 +/- 5.5 mug/d with the addition of shrimps. The apparent absorption of selenium from shrimps was 83 +/- 4%, Faecal and urinary selenium excretion was 32.5 +/- 17.0 mug/d and 21.2 +/- 9.0 mug/d, re...... spectively and the total retention of selenium was 3.1 +/- 1.1 mg. Plasma selenium concentrations were 95.2 +/- 9.7 mug/L and 101.5 +/- 9.7 mug/L before and after six weeks of shrimp intake, respectively (p...

  3. Interaction between mercury (Hg, arsenic (As and selenium (Se affects the activity of glutathione S-transferase in breast milk: possible relationship with fish and shellfish intake

    Directory of Open Access Journals (Sweden)

    Ramón Gaxiola-Robles

    2014-08-01

    Full Text Available Breast milk is regarded as an ideal source of nutrients for the growth and development of neonates, but it can also be a potential source of pollutants. Mothers can be exposed to different contaminants as a result of their lifestyle and environmental pollution. Mercury (Hg and arsenic (As could adversely affect the development of fetal and neonatal nervous system. Some fish and shellfish are rich in selenium (Se, an essential trace element that forms part of several enzymes related to the detoxification process, including glutathione S-transferase (GST. The goal of this study was to determine the interaction between Hg, As and Se and analyze its effect on the activity of GST in breast milk. Milk samples were collected from women between day 7 and 10 postpartum. The GST activity was determined spectrophotometrically; total Hg, As and Se concentrations were measured by atomic absorption spectrometry. To explain the possible association of Hg, As and Se concentrations with GST activity in breast milk, generalized linear models were constructed. The model explained 44% of the GST activity measured in breast milk. The GLM suggests that GST activity was positively correlated with Hg, As and Se concentrations. The activity of the enzyme was also explained by the frequency of consumption of marine fish and shellfish in the diet of the breastfeeding women.

  4. Selenium deficiency and the effects of supplementation on preterm infants

    Directory of Open Access Journals (Sweden)

    Renata Germano B. O. N. Freitas

    2014-03-01

    Full Text Available Objective: This study aimed to review the literature about blood concentrations of selenium associated with gestational age, feeding, supplementation and related clinical features in preterm infants. Data sources: Systematic review in the following databases: MEDLINE, PubMed, Google academics, SciELO. org, ScienceDirect (Elsevier and CINAHL-Plus with Full Text (EBSCO. Articles published up to January 2013 with the keywords "selenium deficiency", "selenium supplementation", "neonates", "infants", "newborn" and "preterm infants" were selected. Data synthesis: The studies reported that low blood selenium levels are associated with increased risk of respiratory diseases. Preterm infants, especially with low birth weight, presented lower selenium levels. Selenium deficiency has also been associated with the use of oral infant formula, enteral and parenteral nutrition (with or without selenium addition. The optimal dose and length of selenium supplementation is not well-established, since they are based only on age group and selenium ingestion by breastfed children. Furthermore, the clinical status of the infant affected by conditions that may increase oxidative stress, and consequently, selenium requirements is not taken into account. Conclusions: Prematurity and low birth weight can contribute to low blood selenium in premature infants. Selenium supplementation seems to minimize or prevent clinical complications caused by prematurity.

  5. Co-ordinated research programme on isotope-aided studies of the bioavailability of iron and zinc from human diets

    International Nuclear Information System (INIS)

    Nutritional deficiencies of essential micronutrients (particularly of iron, but also of zinc and selenium) are known to affect hundreds of millions of people throughout the world, mainly in developing countries. Such deficiencies can lead to significant deficits in mental development, growth, work performance, immune competence and other biological parameters. In many of the population groups that are affected, the deficiencies are thought to be due not to an absolute lack of the element in the diet but rather to is poor bioavailability. Much work has already been done on this subject, particularly in some developed countries and particularly with respect to iron. However, there is still appears to be a need for more research on factors affecting bioavailability and the means to improve it by simple dietary modification and fortification using food products of the kind that may be locally available in developing countries. Isotope techniques potentially have a large role to play in studies of the bioavailability of iron and other trace elements. To support work in this area, the IAEA initiated a Co-ordinated Research Programme (CRP) at the end of 1990 on ''Isotope-Aided Studies of the Bioavailability of Iron and Zinc from Human Diets''. The first Research Co-ordination Meeting (RCM) of participants in this CRP is the subject of the present report. Refs, figs and tabs

  6. Flavonoid-mediated inhibition of intestinal ABC transporters may affect the oral bioavailability of drugs, food-borne toxic compounds and bioactive ingredients

    NARCIS (Netherlands)

    Brand, W.; Schutte, M.E.; Bladeren, van P.J.; Rietjens, I.M.C.M.

    2006-01-01

    The transcellular transport of ingested food ingredients across the intestinal epithelial barrier is an important factor determining bioavailability upon oral intake. This transcellular transport of many chemicals, food ingredients, drugs or toxic compounds over the intestinal epithelium can be high

  7. Selenium and Human Health

    Directory of Open Access Journals (Sweden)

    M Abedi

    2013-04-01

    Full Text Available Introduction: Selenium is an essential element for human health and it is toxic at high concentrations. Selenium is a constituent component of selenoproteins that have enzymatic and structural roles in human biochemistry. Selenium is a best antioxidant and catalyst for production of thyroid hormone. This element has the key role in the immune function; prevention of AIDS progression and the deactivity of toxins. Furthermore, selenium is essential for sperm motility and can reduce abortions. Selenium deficiency was also associated with adverse mood states. The findings regarding cardiovascular disease risk related to selenium deficiency is unclear, though other conditions such as vascular inflammation, oxidative stress and selenium deficiency can cause this disease too. Moreover, consuming of 60 mg of selenium per day may be associated with reduction of cancer risk. In this study, a review of studies has been performed on the biochemical function of selenium toxicity, and its effects on human health. Furthermore, certain identified cancers associated with selenium have been discussed to absorb more attention to the status of this element and also as a guide for further studies. Selenium plays the dual character (useful and harmful in human health, and then it is necessary to determine the concentration of this element in body fluids and tissues. An appropriate method for routine measurement of selenium in clinical laboratories is electro thermal atomic absorption spectrometry (ETAAS with very low detection limit and good precision.

  8. Heavy metals in soils from Baia Mare mining impacted area (Romania) and their bioavailability

    Science.gov (United States)

    Roba, Carmen; Baciu, Calin; Rosu, Cristina; Pistea, Ioana; Ozunu, Alexandru

    2015-04-01

    Keywords: heavy metals, soil contamination, bioavailability, Romania The fate of various metals, including chromium, nickel, copper, manganese, mercury, cadmium, and lead, and metalloids, like arsenic, antimony, and selenium, in the natural environment is of great concern, particularly in the vicinity of former mining sites, dumps, tailings piles, and impoundments, but also in urban areas and industrial centres. Most of the studies focused on the heavy metal pollution in mining areas present only the total amounts of metals in soils. The bioavailable concentration of metals in soil may be a better predictor for environmental impact of historical and current dispersion of metals. Assessment of the metal bioavailability and bioaccessibility is critical in understanding the possible effects on soil biota. The bioavailability of metals in soil and their retention in the solid phase of soil is affected by different parameters like pH, metal amount, cation-exchange capacity, content of organic matter, or soil mineralogy. The main objectives of the present study were to determine the total fraction and the bioavailable fraction of Cu, Cd, Pb and Zn from soil in a well-known mining region in Romania, and to evaluate the influence of soil pH on the metal bioavailability in soil. The heavy metal contents and their bioavailability were monitored in a total of 50 soil samples, collected during June and July 2014 from private gardens of the inhabitants from Baia-Mare area. The main mining activities developed in the area consisted of non-ferrous sulphidic ores extraction and processing, aiming to obtain concentrates of lead, copper, zinc and precious metals. After 2006, the metallurgical industry has considerably reduced its activity by closing or diminishing its production capacity. The analysed soil samples proved to have high levels of Pb (50 - 830 mg/kg), Cu (40 - 600 mg/kg), Zn (100 - 700 mg/kg) and Cd (up to 10 mg/kg). The metal abundance in the total fraction is

  9. Bioavailability & Bioequivalence Studies ? Pharmaceutical Importance

    Directory of Open Access Journals (Sweden)

    Pratibha Muntha

    2015-04-01

    Full Text Available Pharmacokinetics has now emerged as an important part of drug development especially in the development of new drugs. The combined studies of Pharmacodynamics and pharmacokinetics present a thorough understanding on how the drug affects the body and how the body affects the drug.Bioavailability is the study of the rate and extent to which the active ingredient is absorbed from a dosage form and it is available at the required action site. Bioequivalence is that there should not be any significant difference in bioavailability between two products.Bioavailability (BA and bioequivalence (BE studies play a key role during the phase of drug development for both innovator drugs and generic drugs and thus have gained great attention over the past few decades. BE is used to introduce generic drugs of innovator drugs at a lower cost. So a thorough understanding of these BA/BE studies is required

  10. Effects of inclusion of selenium-enriched yeast in the diet of laying hens on performance, eggshell quality, and selenium tissue deposition

    Directory of Open Access Journals (Sweden)

    Guido Invernizzi

    2013-01-01

    Full Text Available The aim of this study was to evaluate the bioavailability of ingested selenium (Se yeast in laying hens and its effects on performance, eggshell quality, and tissue Se distribution. Forty-eight ISA brown laying hens were divided into 3 treatment groups: Group C, fed a basal diet containing 0.11 mg Se/kg of feed; Group SS, fed a basal diet plus 0.4 mg/kg of feed of Se from sodium selenite; and Group SY, fed a basal diet plus 0.4 mg/kg of feed of Se from selenium yeast. Feed intake, egg mass ratio, and production performance were not affected by Se supplementation, regardless of the Se source. Egg weight (+3.61% and +2.95%, eggshell weight (+4.26% and +5.38%, and eggshell surface (+2.43% and +1.96% were higher (P<0.05 in SS and SY than C, whereas breaking strength was increased in SY (P<0.01. Breast muscle, liver and skin Se levels were higher in SY than in C, while kidney Se content was higher in SS hens. Eggs from SY had higher Se levels than SS. Blood metabolites were not affected in SS or SY groups than C. A higher Se level was detected in eggs and breast muscle of SY hens (P<0.05. Selenium-enriched eggs and edible tissues from organic Se sources in poultry diet could improve antioxidant status in humans and reduce possible Se deficiency-related diseases.

  11. Lentils (Lens culinaris L.) as a source of dietary selenium

    Science.gov (United States)

    The chapter discusses the nutritional value of lentils, with a focus on factors affecting lentils as a source of dietary selenium. It addresses the chemical nature of lentil-selenium, pointing out that more than 90% is present in organic compounds which are generally well absorbed by humans. The se...

  12. Deposition station for selenium isotopes

    International Nuclear Information System (INIS)

    Complete text of publication follows. Isotopic tracing of nanoparticles mostly involved in environmental and metabolic processes, industrial, and agricultural technologies, attracts an increasing attention nowadays. As an experimental goal, for proposed tracing studies selenium was chosen, which is an essential trace element for the nutrition of almost all living organisms, since it plays a crucial role in the antioxidant activity of seleno-enzymes. Selenium in forms of nanoparticles being synthesized by wet chemical or microbial dissimilatory processes, turned out to possess new functionality as examplified in affecting semiconductor properties, toxicity, and growth factors, which are important for both nutritional supplements and potential cancer therapy agents. Stable isotope tracing of selenium nanoparticles under in vivo conditions would then yield relevant information on biodistributions, efficiency and safety issues of applications. A prototype version of a deposition station for enrichment of stable selenium isotopes was constructed and installed downstream to the sector magnet of the DiSP isotope separator. The deposition of the isotopic beam particles was carried out with the use of selfsputtering technique. The beam with a kinetic energy of 25-30 keV was first guided through electrostatic elements, where it was focused and decelerated to 300-500 eV (Fig. 1). The geometry of the electrostatic lenses was designed with the simulation code SIMION 8. The outcoming beam impinged upon the surface of a tungsten disc, on which recombination and selfsputtering of selenium ions occurred. Sputtering yields and efficiencies were measured as a function of beam intensities. It was concluded that emission of the selenium atoms can be predominantly attributed to heat spike mechanism due to large differences in evaporation characteristics of selenium and tungsten. The selenium atoms were then deposited as a thin film on a polypropylene (PP) surface with a conical geometry

  13. The role of selenium in predicting preeclampsia

    Directory of Open Access Journals (Sweden)

    Z Ghaemi

    2013-10-01

    Full Text Available Introduction: Preeclampsia is a common disorder that is a leading cause of perinatal and maternal morbidity and mortality; however its specific etiology has still remained obscure.The first step in preventing preeclampsia is early detection of women at risk. Since there is no valid and reliable screening test, appropriate diagnostic and screening tests are necessary, which are inexpensive, non-invasive and beneficial for pregnant women. Therefore, regarding the role of selenium as an antioxidant in the prevention preeclampsia, this study was designed which aimed to determine the prognostic value of plasma selenium levels in the diagnosis of preeclampsia in primigravida women Methods: In a nested case control design, a sample of 650 normal primigravida women of 24-28 weeks participated in the study. Subjects who involved the case group were followed up for 3 months and 38 were affected by preeclampsia. Blood samples were obtained from these 38patients as well as from 38 subjects as their matched controls. Moreover, the amount of selenium was measured by atomic absorption spectrometry. Results: The mean level of selenium in blood plasma of the cases was significantly lower than in their matched controls. The present study findings revealed that pregnant women with serum Se < 66.1 μg/L had a significantly increased risk of preeclampsia. Conclusion: Lower plasma selenium level in women destines to suffering from preeclampsia which confirms the destructive effect of selenium deficiency as an antioxidant in etiopathology of preeclampsia. Measurement of plasma selenium can improve the prediction of preeclampsia; thus, it seems that plasma selenium level test owns an acceptable sensitivity and specificity for predicting preeclampsia.

  14. Copper and selenium supplementation in the diet of Brangus steers on the nutritional characteristics of meat

    Directory of Open Access Journals (Sweden)

    Arlindo Saran Netto

    2013-01-01

    Full Text Available Twenty-eight Brangus cattle were used to determine the effect of copper and selenium supplementation on the carcass characteristics, fatty acid composition of the longissimus dorsi muscle and on the copper and selenium concentrations in the liver. The treatments were: no supplementation of copper or selenium; 2 mg Se/kg DM as sodium selenite; 40 mg Cu/kg DM as copper sulfate; and 2 mg Se/kg DM as sodium selenite and 40 mg Cu/kg DM as copper sulfate. The fat thickness, rib eye area and fatty acid composition of the longissimus dorsi muscle were not affected by treatments. There was no effect on carcass yield and cooling loss with the supplementation of copper, selenium or selenium × copper in the levels studied. For the ether extract concentration in the longissimus dorsi muscle, no differences were found according to the treatments with selenium, copper or selenium × copper. The treatments with selenium and selenium × copper showed higher selenium concentrations in the liver than the control and copper treatments. For the copper concentration in the liver, the copper and selenium × copper treatments showed higher values than the control and selenium treatments. Despite the little effect on the meat composition, the results of this experiment demonstrate no interaction between selenium and copper in the levels studied.

  15. Bioavailability & Bioequivalence Studies ? Pharmaceutical Importance

    OpenAIRE

    Pratibha Muntha

    2015-01-01

    Pharmacokinetics has now emerged as an important part of drug development especially in the development of new drugs. The combined studies of Pharmacodynamics and pharmacokinetics present a thorough understanding on how the drug affects the body and how the body affects the drug.Bioavailability is the study of the rate and extent to which the active ingredient is absorbed from a dosage form and it is available at the required action site. Bioequivalence is that the...

  16. A quality assurance programme for the determination of selenium in foods by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Selenium is unevenly distributed through the biosphere. The levels, species and bioavailability of selenium in foods depend greatly on the geochemical environment in which they are grown. Variation in geochemical conditions can not only lead to certain diseases in animals but also influence the selenium body burden in humans. For these reasons, there is an increasing interest in monitoring selenium levels in foods and diets. A quality assurance programme has been developed for the determination of low levels of selenium in foods and diets by cyclic and pseudo-cyclic instrumental neutron activation analysis (INAA) using the short-lived (half-life = 17.4 s) 77Sem nuclide. Both conventional and anti-coincidence gamma ray spectrometry techniques have been employed. Pseudo-cyclic INAA in conjunction with anti-coincidence counting has been found to provide the most reliable results. Internal and external quality assessments have been done using a number of parameters. (author)

  17. Bioavailability of xenobiotics in the soil environment.

    Science.gov (United States)

    Katayama, Arata; Bhula, Raj; Burns, G Richard; Carazo, Elizabeth; Felsot, Allan; Hamilton, Denis; Harris, Caroline; Kim, Yong-Hwa; Kleter, Gijs; Koedel, Werner; Linders, Jan; Peijnenburg, J G M Willie; Sabljic, Aleksandar; Stephenson, R Gerald; Racke, D Kenneth; Rubin, Baruch; Tanaka, Keiji; Unsworth, John; Wauchope, R Donald

    2010-01-01

    It is often presumed that all chemicals in soil are available to microorganisms, plant roots, and soil fauna via dermal exposure. Subsequent bioaccumulation through the food chain may then result in exposure to higher organisms. Using the presumption of total availability, national governments reduce environmental threshold levels of regulated chemicals by increasing guideline safety margins. However, evidence shows that chemical residues in the soil environment are not always bioavailable. Hence, actual chemical exposure levels of biota are much less than concentrations present in soil would suggest. Because "bioavailability" conveys meaning that combines implications of chemical sol persistency, efficacy, and toxicity, insights on the magnitude of a chemicals soil bioavailability is valuable. however, soil bioavailability of chemicals is a complex topic, and is affected by chemical properties, soil properties, species exposed, climate, and interaction processes. In this review, the state-of-art scientific basis for bioavailability is addressed. Key points covered include: definition, factors affecting bioavailability, equations governing key transport and distributive kinetics, and primary methods for estimating bioavailability. Primary transport mechanisms in living organisms, critical to an understanding of bioavailability, also presage the review. Transport of lipophilic chemicals occurs mainly by passive diffusion for all microorganisms, plants, and soil fauna. Therefore, the distribution of a chemical between organisms and soil (bioavailable proportion) follows partition equilibrium theory. However, a chemical's bioavailability does not always follow partition equilibrium theory because of other interactions with soil, such as soil sorption, hysteretic desorption, effects of surfactants in pore water, formation of "bound residue", etc. Bioassays for estimating chemical bioavailability have been introduced with several targeted endpoints: microbial

  18. Selenium species bioaccessibility in enriched radish (Raphanus sativus): a potential dietary source of selenium.

    Science.gov (United States)

    Pedrero, Zoyne; Madrid, Yolanda; Cámara, Carmen

    2006-03-22

    An in vitro gastrointestinal method was employed to predict the potential bioavailability of selenium and its species from radish, belonging to the Brassicaceae family, grown in hydroponics media in the presence of inorganic selenium, such as Na2SeO3 and Na2SeO4. A low transformation of Se into organic forms was observed in radish plants grown in Se(VI)-enriched culture media. On the contrary, in those plants exposed to selenite, >95% of the total selenium was found as selenocystine (SeCys2), selenomethionine (SeMet), and Se-methylselenocysteine (SeMetSeCys). The concentrations of these species in fresh samples remained almost unaltered after a simulated gastrointestinal digestion. Therefore, a high selenium content of Se-methylselenocysteine (65%), previously reported as a cancer chemopreventive species, remained in the potentially bioabsorbable fraction. As these plants usually undergo a short development cycle, these results suggest that radish enriched in selenite could be a good choice as an organoselenium supplement for the human diet and animal feed. PMID:16536627

  19. Evaluation of the nutritional quality of veal supplemented with organic selenium and its effect on selenium status of people

    Directory of Open Access Journals (Sweden)

    Klára Vavrišínová

    2016-05-01

    Full Text Available In the first stage of our research we found out a higher content of selenium in the meat of calves of experimental group (with added the organic form of selenium to the feed mixture compared to control group (fed without organic form of selenium. In the second stage of our research we focused on monitoring the impact of selenium enriched veal meat and on selenium concentration in blood serum and the selected biochemical parameters of lipid spectrum of the experimental group of volunteers. Ten people who were participating in the research were at the age range between 29 - 56 years. All the volunteers consumed veal meat enriched with organic selenium for 4 weeks. Before starting the experiment we took venous blood of the volunteers and this blood was considered as a control sample of selenium in blood serum of the experimental group. Selenium concentration in blood serum of the examined group was determined by an average of 58.31 ±5.36 mg.L.-1 and none of them reached the optimal level of selenium. Consequently, we carried out the additional blood sampling after 2 and 4 weeks of the consumption of veal meat. There was registered a slight increasing of selenium status, whereas after the finishing the consumption, we determined the average selenium concentration in blood serum of the experimental group 60.73 ±4.05 mg.L-1. The evaluation of lipid profile of the experimental group showed (after input blood sampling higher values of total cholesterol level and lower levels of HDL cholesterol. This fact shows the higher risk of starting the cardiovascular diseases. Reported research results didn't show statistically significant changes of blood lipid spectrum of the experimental group. We concluded that the consumption of supplemented veal meat can positively affect the level of selenium in our body and thereby increase it can increase the protective effect against the influence of free radicals.

  20. Bioavailability of Promethazine during Spaceflight

    Science.gov (United States)

    Boyd, Jason L.; Wang, Zuwei; Putcha, Lakshmi

    2009-01-01

    Promethazine (PMZ) is the choice anti-motion sickness medication for treating space motion sickness (SMS) during flight. The side effects associated with PMZ include dizziness, drowsiness, sedation, and impaired psychomotor performance which could impact crew performance and mission operations. Early anecdotal reports from crewmembers indicate that these central nervous system side effects of PMZ are absent or greatly attenuated in microgravity, potentially due to changes in pharmacokinetics (PK) and pharmacodynamics in microgravity. These changes could also affect the therapeutic effectiveness of drugs in general and PMZ, in particular. In this investigation, we examined bioavailability and associated pharmacokinetics of PMZ in astronauts during and after space flight. Methods. Nine astronauts received, per their preference, PMZ (25 or 50 mg as intramuscular injection, oral tablet, or rectal suppository) on flight day one for the treatment of SMS and subsequently collected saliva samples and completed sleepiness scores for 72 h post dose. Thirty days after the astronauts returned to Earth, they repeated the protocol. Bioavailability and PK parameters were calculated and compared between flight and ground. Results. Maximum concentration (Cmax) was lower and time to reach Cmax (tmax) was longer in flight than on the ground. Area under the curve (AUC), a measure of bioavailability, was lower and biological half-life (t1/2) was longer in flight than on the ground. Conclusion. Results indicate that bioavailability of PMZ is reduced during spaceflight. Number of samples, sampling method, and sampling schedule significantly affected PK parameter estimates.

  1. Why Nature Chose Selenium.

    Science.gov (United States)

    Reich, Hans J; Hondal, Robert J

    2016-04-15

    The authors were asked by the Editors of ACS Chemical Biology to write an article titled "Why Nature Chose Selenium" for the occasion of the upcoming bicentennial of the discovery of selenium by the Swedish chemist Jöns Jacob Berzelius in 1817 and styled after the famous work of Frank Westheimer on the biological chemistry of phosphate [Westheimer, F. H. (1987) Why Nature Chose Phosphates, Science 235, 1173-1178]. This work gives a history of the important discoveries of the biological processes that selenium participates in, and a point-by-point comparison of the chemistry of selenium with the atom it replaces in biology, sulfur. This analysis shows that redox chemistry is the largest chemical difference between the two chalcogens. This difference is very large for both one-electron and two-electron redox reactions. Much of this difference is due to the inability of selenium to form π bonds of all types. The outer valence electrons of selenium are also more loosely held than those of sulfur. As a result, selenium is a better nucleophile and will react with reactive oxygen species faster than sulfur, but the resulting lack of π-bond character in the Se-O bond means that the Se-oxide can be much more readily reduced in comparison to S-oxides. The combination of these properties means that replacement of sulfur with selenium in nature results in a selenium-containing biomolecule that resists permanent oxidation. Multiple examples of this gain of function behavior from the literature are discussed. PMID:26949981

  2. Bioavailability of heavy metals, germanium and rare earth elements at Davidschacht dump-field in mine affected area of Freiberg (Saxony)

    Science.gov (United States)

    Midula, Pavol; Wiche, Oliver

    2016-04-01

    Bioavailability research presents an essential tool, in modern phytoremediation and phytomining technologies, allowing the estimation of plant available fractions of elements in soils. However, up to date, sufficient interdisciplinary knowledge on the biogeochemically impacted behavior of specific target elements, in particular Ge and REEs in mining affected soils and their uptake into strategically used plants is lacking. This presented work is focused on a correlation study between the concentrations of selected heavy metals, Ge and REEs in soils formed on the top of the dump-field of Davidschacht and the corresponding their concentrations in 12 vascular plant species. The mine-dump of Davidschacht, situated in the Freiberg (Saxony, Germany) municipality area was chosen as the study area, which has been considered to be a high contaminated enclave, due to the mining history of the region. In total 12 sampling sites with differing composition of plant species were selected. At each sampling site soil samples from a soil depth of 0 - 10 cm and samples of plant material (shoots) were taken. The soil samples were analysed for total concentration of elements, pH (H2O) and consequently analysed by 4-step sequential extraction (SE) to determine fractions of elements that are mobile (fraction 1), acid soluble (pH 5) (fraction 2), bound to organic and oxidizable matter (fraction 3) and bound to amorphic oxides (fraction 4). The plant material was decomposed by hydrofluoric acid in order to extract the elements. Concentrations of elements in soil extracts and digestion solutions were analysed by ICP-MS. For all species bioconcentration factor (BCF) was calculated of the total concentration of elements in order to investigate the bioaccumulation potential. Arsenic (As), cadmium (Cd) and lead (Pb) were chosen as the representative heavy metals. Within the REEs neodymium (Nd) and cerium (Ce) were selected as representatives for all REEs, since Nd and Ce correlated significant

  3. Bioavailability of heavy metals, germanium and rare earth elements at Davidschacht dump-field in mine affected area of Freiberg (Saxony)

    Science.gov (United States)

    Midula, Pavol; Wiche, Oliver

    2016-04-01

    Bioavailability research presents an essential tool, in modern phytoremediation and phytomining technologies, allowing the estimation of plant available fractions of elements in soils. However, up to date, sufficient interdisciplinary knowledge on the biogeochemically impacted behavior of specific target elements, in particular Ge and REEs in mining affected soils and their uptake into strategically used plants is lacking. This presented work is focused on a correlation study between the concentrations of selected heavy metals, Ge and REEs in soils formed on the top of the dump-field of Davidschacht and the corresponding their concentrations in 12 vascular plant species. The mine-dump of Davidschacht, situated in the Freiberg (Saxony, Germany) municipality area was chosen as the study area, which has been considered to be a high contaminated enclave, due to the mining history of the region. In total 12 sampling sites with differing composition of plant species were selected. At each sampling site soil samples from a soil depth of 0 - 10 cm and samples of plant material (shoots) were taken. The soil samples were analysed for total concentration of elements, pH (H2O) and consequently analysed by 4-step sequential extraction (SE) to determine fractions of elements that are mobile (fraction 1), acid soluble (pH 5) (fraction 2), bound to organic and oxidizable matter (fraction 3) and bound to amorphic oxides (fraction 4). The plant material was decomposed by hydrofluoric acid in order to extract the elements. Concentrations of elements in soil extracts and digestion solutions were analysed by ICP-MS. For all species bioconcentration factor (BCF) was calculated of the total concentration of elements in order to investigate the bioaccumulation potential. Arsenic (As), cadmium (Cd) and lead (Pb) were chosen as the representative heavy metals. Within the REEs neodymium (Nd) and cerium (Ce) were selected as representatives for all REEs, since Nd and Ce correlated significant

  4. Derivation of a chronic site-specific water quality standard for selenium in the Great Salt Lake, Utah, USA.

    Science.gov (United States)

    Brix, Kevin V; DeForest, David K; Cardwell, Rick D; Adams, William J

    2004-03-01

    The purpose of this study was to develop a site-specific water quality standard for selenium in the Great Salt Lake, Utah, USA. The study examined the bioavailability and toxicity of selenium, as selenate, to biota resident to the Great Salt Lake and the potential for dietary selenium exposure to aquatic dependent birds that might consume resident biota. Because of its high salinity, the lake has limited biological diversity with bacteria, algae, diatoms, brine shrimp, and brine flies being the only organisms present in the main (hypersaline) portions of the lake. To evaluate their sensitivity to selenium, a series of acute and chronic toxicity studies were conducted on brine shrimp (Artemia franiciscana), brine fly (Ephydra cinerea), and a hypersaline alga (Dunaliella viridis). The resulting acute and chronic toxicity data indicated that resident species are more selenium tolerant than many freshwater species. Because sulfate is known to reduce selenate bioavailability, this selenium tolerance is thought to result in part from the lake's high ambient sulfate concentrations (>5,800 mg/L). The acute and chronic test results were compared to selenium concentrations expected to occur in a mining effluent discharge located at the south end of the lake. Based on these comparisons, no appreciable risks to resident aquatic biota were projected. Field and laboratory data collected on selenium bioaccumulation in brine shrimp demonstrated a linear relationship between water and tissue selenium concentrations. Applying a dietary selenium threshold of 5 mg/kg dry weight for aquatic birds to this relationship resulted in an estimate of 27 microg/L Se in water as a safe concentration for this exposure pathway and an appropriate chronic site-specific water quality standard. Consequently, protection of aquatic birds represents the driving factor in determining a site-specific water quality standard for selenium. PMID:15285352

  5. Selenium in Cattle: A Review.

    Science.gov (United States)

    Mehdi, Youcef; Dufrasne, Isabelle

    2016-01-01

    This review article examines the role of selenium (Se) and the effects of Se supplementation especially in the bovine species. Selenium is an important trace element in cattle. Some of its roles include the participation in the antioxidant defense the cattle farms. The nutritional requirements of Se in cattle are estimated at 100 μg/kg DM (dry matter) for beef cattle and at 300 μg/kg DM for dairy cows. The rations high in fermentable carbohydrates, nitrates, sulfates, calcium or hydrogen cyanide negatively influence the organism's use of the selenium contained in the diet. The Se supplementation may reduce the incidence of metritis and ovarian cysts during the postpartum period. The increase in fertility when adding Se is attributed to the reduction of the embryonic death during the first month of gestation. A use of organic Se in feed would provide a better transfer of Se in calves relative to mineral Se supplementation. The addition of Se yeasts in the foodstuffs of cows significantly increases the Se content and the percentage of polyunsaturated fatty acids (PUFA) in milk compared to the addition of sodium selenite. The enzyme 5-iodothyronine deiodinase is a seleno-dependent selenoprotein. It is one of the last proteins to be affected in the event of Se deficiency. This delay in response could explain the fact that several studies did not show the effect of Se supplementation on growth and weight gain of calves. Enrichment of Se in the diet did not significantly affect the slaughter weight and carcass yield of bulls. The impact and results of Se supplementation in cattle depend on physiological stage, Se status of animals, type and content of Se and types of Se administration. Further studies in Se supplementation should investigate the speciation of Se in food and yeasts, as well as understanding their metabolism and absorption. This constitute a path to exploit in order to explain certain different effects of Se. PMID:27120589

  6. Selenium in Cattle: A Review

    Directory of Open Access Journals (Sweden)

    Youcef Mehdi

    2016-04-01

    Full Text Available This review article examines the role of selenium (Se and the effects of Se supplementation especially in the bovine species. Selenium is an important trace element in cattle. Some of its roles include the participation in the antioxidant defense the cattle farms. The nutritional requirements of Se in cattle are estimated at 100 μg/kg DM (dry matter for beef cattle and at 300 μg/kg DM for dairy cows. The rations high in fermentable carbohydrates, nitrates, sulfates, calcium or hydrogen cyanide negatively influence the organism’s use of the selenium contained in the diet. The Se supplementation may reduce the incidence of metritis and ovarian cysts during the postpartum period. The increase in fertility when adding Se is attributed to the reduction of the embryonic death during the first month of gestation. A use of organic Se in feed would provide a better transfer of Se in calves relative to mineral Se supplementation. The addition of Se yeasts in the foodstuffs of cows significantly increases the Se content and the percentage of polyunsaturated fatty acids (PUFA in milk compared to the addition of sodium selenite. The enzyme 5-iodothyronine deiodinase is a seleno-dependent selenoprotein. It is one of the last proteins to be affected in the event of Se deficiency. This delay in response could explain the fact that several studies did not show the effect of Se supplementation on growth and weight gain of calves. Enrichment of Se in the diet did not significantly affect the slaughter weight and carcass yield of bulls. The impact and results of Se supplementation in cattle depend on physiological stage, Se status of animals, type and content of Se and types of Se administration. Further studies in Se supplementation should investigate the speciation of Se in food and yeasts, as well as understanding their metabolism and absorption. This constitute a path to exploit in order to explain certain different effects of Se.

  7. Commentary: selenium study on endangered razorback sucker is flawed.

    Science.gov (United States)

    Hamilton, Steven J

    2005-07-01

    The razorback sucker (Xyrauchen texanus) is listed as federally endangered throughout its range. A massive recovery effort by the Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin has focused its efforts in the upper Colorado River. The upper Colorado River basin also has two locations that have been identified by the National Irrigation Water Quality Program as having substantial selenium contamination. Selenium is toxic to fishes, affecting reproductive success. Thus, there is concern about potential effects of selenium on the endangered razorback sucker. Two sets of studies have investigated the effects of selenium on razorback suckers, but study results are conflicting. This commentary evaluates studies that claim selenium is not a problem for razorback sucker. We find that study bias was so pervasive that purported conclusions were unwarranted. Contaminated control water, older life stages of fish tested, lack of methodology for analysis of selenium in water, diet, or fish, use of rotifer food, low feeding rates, low growth rates of fish, and improper storage of site waters resulted in an apparent erroneous linkage of high selenium in whole-body residues with no adverse effects. PMID:15922797

  8. Low selenium and reduced cognitive function in a cohort elderly study

    Institute of Scientific and Technical Information of China (English)

    Jianchao Bian; Sujuan Gao; Qiliang Qin; Zhongjie Yun; Yuan Liu; Shuliang Song; Chuanjiao Liu; Xiaohong Luo; Jie Gao; Chaoke Liang

    2010-01-01

    Cognitive function in the elderly is affected by various environmental,social,and individual factors.Studies show that chemical trace elements are closely related to cognitive function.As a protective factor,selenium promotes cognition in the elderly.However,study results into the effects of selenium on cognition have varied.By eliminating unstable environmental and other related factors,the present study selected elderly individuals from rural areas of the Shandong province to verify whether low selenium exposure is a risk factor for decreased cognitive function.Results demonstrated that age,sex,education,occupation,hypertension,stroke,and body selenium levels were factors affecting cognitive function in the elderly,and that selenium was an important protective factor.Moreover,results supported the hypothesis that a lifelong low selenium level is associated with low cognitive function.

  9. Selenium Uptake and Volatilization by Marine Algae

    Science.gov (United States)

    Luxem, Katja E.; Vriens, Bas; Wagner, Bettina; Behra, Renata; Winkel, Lenny H. E.

    2015-04-01

    Selenium (Se) is an essential trace nutrient for humans. An estimated one half to one billion people worldwide suffer from Se deficiency, which is due to low concentrations and bioavailability of Se in soils where crops are grown. It has been hypothesized that more than half of the atmospheric Se deposition to soils is derived from the marine system, where microorganisms methylate and volatilize Se. Based on model results from the late 1980s, the atmospheric flux of these biogenic volatile Se compounds is around 9 Gt/year, with two thirds coming from the marine biosphere. Algae, fungi, and bacteria are known to methylate Se. Although algal Se uptake, metabolism, and methylation influence the speciation and bioavailability of Se in the oceans, these processes have not been quantified under environmentally relevant conditions and are likely to differ among organisms. Therefore, we are investigating the uptake and methylation of the two main inorganic Se species (selenate and selenite) by three globally relevant microalgae: Phaeocystis globosa, the coccolithophorid Emiliania huxleyi, and the diatom Thalassiosira oceanica. Selenium uptake and methylation were quantified in a batch experiment, where parallel gas-tight microcosms in a climate chamber were coupled to a gas-trapping system. For E. huxleyi, selenite uptake was strongly dependent on aqueous phosphate concentrations, which agrees with prior evidence that selenite uptake by phosphate transporters is a significant Se source for marine algae. Selenate uptake was much lower than selenite uptake. The most important volatile Se compounds produced were dimethyl selenide, dimethyl diselenide, and dimethyl selenyl sulfide. Production rates of volatile Se species were larger with increasing intracellular Se concentration and in the decline phase of the alga. Similar experiments are being carried out with P. globosa and T. oceanica. Our results indicate that marine algae are important for the global cycling of Se

  10. Selenium in human mammary carcinogenesis

    DEFF Research Database (Denmark)

    Overvad, Kim; Grøn, P.; Langhoff, Otto;

    1991-01-01

    In a case-referent study on the possible role of selenium in human mammary carcinogenesis, serum selenium was found to be 79 +/- 12 micrograms/l in 66 cases and 81 +/- 12 micrograms/l in 93 referents. An internal trend in serum selenium was observed among cases (TNM stage I 81 +/- 11 micrograms....../l and TNM stage II 76 +/- 13 micrograms selenium/l), indicating disease-mediated changes. The evaluation of selenium as a risk indicator in human breast cancer was therefore restricted to TNM stage I patients (n = 36). Multiple logistic regression analyses including variables associated with selenium...... levels revealed no association between selenium levels and breast cancer risk....

  11. Selenium and Selenoprotein Deficiencies Induce Widespread Pyogranuloma Formation in Mice, while High Levels of Dietary Selenium Decrease Liver Tumor Size Driven by TGFα

    Science.gov (United States)

    Zhong, Nianxin; Ward, Jerrold M.; Perella, Christine M.; Hoffmann, Victoria J.; Rogers, Keith; Combs, Gerald F.; Schweizer, Ulrich; Merlino, Glenn; Gladyshev, Vadim N.; Hatfield, Dolph L.

    2013-01-01

    Changes in dietary selenium and selenoprotein status may influence both anti- and pro-cancer pathways, making the outcome of interventions different from one study to another. To characterize such outcomes in a defined setting, we undertook a controlled hepatocarcinogenesis study involving varying levels of dietary selenium and altered selenoprotein status using mice carrying a mutant (A37G) selenocysteine tRNA transgene (TrsptG37) and/or a cancer driver TGFα transgene. The use of TrsptG37 altered selenoprotein expression in a selenoprotein and tissue specific manner and, at sufficient dietary selenium levels, separate the effect of diet and selenoprotein status. Mice were maintained on diets deficient in selenium (0.02 ppm selenium) or supplemented with 0.1, 0.4 or 2.25 ppm selenium or 30 ppm triphenylselenonium chloride (TPSC), a non-metabolized selenium compound. TrsptG37 transgenic and TGFα/TrsptG37 bi-transgenic mice subjected to selenium-deficient or TPSC diets developed a neurological phenotype associated with early morbidity and mortality prior to hepatocarcinoma development. Pathology analyses revealed widespread disseminated pyogranulomatous inflammation. Pyogranulomas occurred in liver, lungs, heart, spleen, small and large intestine, and mesenteric lymph nodes in these transgenic and bi-transgenic mice. The incidence of liver tumors was significantly increased in mice carrying the TGFα transgene, while dietary selenium and selenoprotein status did not affect tumor number and multiplicity. However, adenoma and carcinoma size and area were smaller in TGFα transgenic mice that were fed 0.4 and 2.25 versus 0.1 ppm of selenium. Thus, selenium and selenoprotein deficiencies led to widespread pyogranuloma formation, while high selenium levels inhibited the size of TGFα–induced liver tumors. PMID:23460847

  12. Selenium Metabolism in Cancer Cells: The Combined Application of XAS and XFM Techniques to the Problem of Selenium Speciation in Biological Systems

    Directory of Open Access Journals (Sweden)

    Hugh H. Harris

    2013-05-01

    Full Text Available Determining the speciation of selenium in vivo is crucial to understanding the biological activity of this essential element, which is a popular dietary supplement due to its anti-cancer properties. Hyphenated techniques that combine separation and detection methods are traditionally and effectively used in selenium speciation analysis, but require extensive sample preparation that may affect speciation. Synchrotron-based X-ray absorption and fluorescence techniques offer an alternative approach to selenium speciation analysis that requires minimal sample preparation. We present a brief summary of some key HPLC-ICP-MS and ESI-MS/MS studies of the speciation of selenium in cells and rat tissues. We review the results of a top-down approach to selenium speciation in human lung cancer cells that aims to link the speciation and distribution of selenium to its biological activity using a combination of X-ray absorption spectroscopy (XAS and X-ray fluorescence microscopy (XFM. The results of this approach highlight the distinct fates of selenomethionine, methylselenocysteine and selenite in terms of their speciation and distribution within cells: organic selenium metabolites were widely distributed throughout the cells, whereas inorganic selenium metabolites were compartmentalized and associated with copper. New data from the XFM mapping of electrophoretically-separated cell lysates show the distribution of selenium in the proteins of selenomethionine-treated cells. Future applications of this top-down approach are discussed.

  13. Human Folate Bioavailability

    Directory of Open Access Journals (Sweden)

    Cornelia M. Witthoft

    2011-04-01

    Full Text Available The vitamin folate is recognized as beneficial health-wise in the prevention of neural tube defects, anemia, cardiovascular diseases, poor cognitive performance, and some forms of cancer. However, suboptimal dietary folate intake has been reported in a number of countries. Several national health authorities have therefore introduced mandatory food fortification with synthetic folic acid, which is considered a convenient fortificant, being cost-efficient in production, more stable than natural food folate, and superior in terms of bioavailability and bioefficacy. Other countries have decided against fortification due to the ambiguous role of synthetic folic acid regarding promotion of subclinical cancers and other adverse health effects. This paper reviews recent studies on folate bioavailability after intervention with folate from food. Our conclusions were that limited folate bioavailability data are available for vegetables, fruits, cereal products, and fortified foods, and that it is difficult to evaluate the bioavailability of food folate or whether intervention with food folate improves folate status. We recommend revising the classical approach of using folic acid as a reference dose for estimating the plasma kinetics and relative bioavailability of food folate.

  14. Marine lipids and the bioavailability of omega-3 fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Müllertz, Anette

    2015-01-01

    Marine lipids are enriched with omega-3 fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Omega-3 fatty acids are important membrane lipids and have many recognized health benefits, the bioavailability of these fatty acids can therefore be important for achieving...... bioavailability of omega-3 fatty acids has been reported to be affected by several factors; among the important factors were the digestion and absorption processes of omega-3 containing lipids in the gastrointestinal tract. Both lipid structures and food structures can affect the bioavailability of omega-3 fatty....... In vitro studies provided a mechanistic understanding on the varied bioavailability caused by different lipid structures, the lower relative bioavailability of omega-3 fatty acids from FAEE formulation was closely related to the slower digestion rate of FAEE. Microencapsulated fish oil has often been...

  15. Bioavailability of Tea Polyphenols

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Tea is a pleasant, popular and safe beverage. Tea provides a dietary source of bioactive components to help humans reduce a wide variety of cancer risks and chronic diseases. The antioxidative activity of green tea-derived polypbenols known as catchins has been extensively studied. The reducfive effect is a synergistic action between EGCG,EGC, ECG, EC, pheophytins a and b, and other components in tealeaves, which are more bioavailable for human body.Green tea has a higher content of catechins than black tea. Green tea extract with hot water has high potential and more efficiencytoreducecancerriskthananyotherteaproductsorpureEGCG. Protein, iron, andotherfoodcomponentsmay interfere with the bioavailability of tea polyphenols. Drinkinggreentea (orpolyphenol-rich tea extract ) also enhances the cancer-preventive activity of some cancer-fighting medication such as Sulindac and Tamoxifen. Further studies are required to determine the bioavailability of green tea and cancer-preventive functionality.

  16. Bioavailability and generic prescribing.

    Science.gov (United States)

    Mindel, J S

    1976-01-01

    Although oral drug bioinequivalence has been attributed to a number of causes (excipients, dosage form, variation in dissolution time, and aging) less is known about bioavailability problems of topical medications in ophthalmology. Factors that can alter drug absorption from solutions (pH, partition coefficient, container impurities, contact time, etc.) are noted, and cases in which bioavailability problems should be considered as causes of therapeutic failure are discussed. Various attitudes representing pharmaceutical companies, the federal government, pharmacists, consumers and physicians toward the related problems of bioinequivalence and generic prescribing are examined. Techniques for in vivo and in vitro drug testing and for establishing uniform conditions of drug manufacture and storage can contribute to identification and minimization of bioavailability problems. A rational program based on a combination of such techniques could, ultimately, lead to establishment of the terms "generic equivalency" and "therapeutic equivalency" as synonymous. PMID:13505

  17. Relative Bioavailability and Bioaccessibility and Speciation of Arsenic in Contaminated Soils

    OpenAIRE

    Bradham, Karen D.; Scheckel, Kirk G.; Nelson, Clay M.; Seales, Paul E.; Lee, Grace E.; Hughes, Michael F.; Miller, Bradley W.; Yeow, Aaron; Gilmore, Thomas; Serda, Sophia M.; Harper, Sharon; Thomas, David J

    2011-01-01

    Background: Assessment of soil arsenic (As) bioavailability may profoundly affect the extent of remediation required at contaminated sites by improving human exposure estimates. Because small adjustments in soil As bioavailability estimates can significantly alter risk assessments and remediation goals, convenient, rapid, reliable, and inexpensive tools are needed to determine soil As bioavailability. Objectives: We evaluated inexpensive methods for assessing As bioavailability in soil as a m...

  18. Reduction of selenite by Azospirillum brasilense with the formation of selenium nanoparticles.

    Science.gov (United States)

    Tugarova, Anna V; Vetchinkina, Elena P; Loshchinina, Ekaterina A; Burov, Andrei M; Nikitina, Valentina E; Kamnev, Alexander A

    2014-10-01

    The ability to reduce selenite (SeO(3)(2-)) ions with the formation of selenium nanoparticles was demonstrated in Azospirillum brasilense for the first time. The influence of selenite ions on the growth of A. brasilense Sp7 and Sp245, two widely studied wild-type strains, was investigated. Growth of cultures on both liquid and solid (2 % agar) media in the presence of SeO(3)(2-) was found to be accompanied by the appearance of the typical red colouration. By means of transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS) and X-ray fluorescence analysis (XFA), intracellular accumulation of elementary selenium in the form of nanoparticles (50 to 400 nm in diameter) was demonstrated for both strains. The proposed mechanism of selenite-to-selenium (0) reduction could involve SeO(3)(2-) in the denitrification process, which has been well studied in azospirilla, rather than a selenite detoxification strategy. The results obtained point to the possibility of using Azospirillum strains as endophytic or rhizospheric bacteria to assist phytoremediation of, and cereal cultivation on, selenium-contaminated soils. The ability of A. brasilense to synthesise selenium nanoparticles may be of interest to nanobiotechnology for "green synthesis" of bioavailable amorphous red selenium nanostructures. PMID:24863127

  19. Effects of different selenium sources and levels on serum biochemical parameters and tissue selenium retention in rats

    Institute of Scientific and Technical Information of China (English)

    Fei HAN; Daiwen CHEN; Bing YU; Wenli LUO

    2009-01-01

    A total of 54 female Wistar rats were allotted to nine treatments by weight and fed basal diet or diets containing Se of 0.05, 0.10, 0.15, or 0.20 mg·kg-1 diet provided with either Se yeast or sodium selenite for 10 days. The results showed the following: (1) Selenium yeast had better effects compared with sodium selenite on increasing serum superoxide dismutase activities (P < 0.05). Addition of Se yeast or sodium selenite increased the activities of serum gluthathione peroxidase (P<0.01); (2) According to slope ratio assay, the bioavailability of Se from Se yeast was 132.1%, 205.7%, 140.0%, and 107.2% of that from sodium selenite when glutathione peroxidase activities and Se contents in serum, kidney, and liver were used as indicators. It is concluded that Se from Se yeast has higher bioavailability than Se from sodium selenite.

  20. The Content and Bioavailability of Mineral Nutrients of Selected Wild and Traditional Edible Plants as Affected by Household Preparation Methods Practiced by Local Community in Benishangul Gumuz Regional State, Ethiopia

    OpenAIRE

    Andinet Abera Hailu; Getachew Addis

    2016-01-01

    Edible parts of some wild and traditional vegetables used by the Gumuz community, namely, Portulaca quadrifida, Dioscorea abyssinica, Abelmoschus esculentus, and Oxytenanthera abyssinica, were evaluated for their minerals composition and bioavailability. Mineral elements, namely, Ca, Fe, Zn, and Cu, were analyzed using Shimadzu atomic absorption spectrophotometer. Effects of household processing practices on the levels of mineral elements were evaluated and the bioavailability was predicted u...

  1. Effect of dietary selenium and omega-3 fatty acids on muscle composition and quality in broilers

    Directory of Open Access Journals (Sweden)

    Hetland Harald

    2007-10-01

    Full Text Available Abstract Background Human health may be improved if dietary intakes of selenium and omega-3 fatty acids are increased. Consumption of broiler meat is increasing, and the meat content of selenium and omega-3 fatty acids are affected by the composition of broiler feed. A two-way analyses of variance was used to study the effect of feed containing omega-3 rich plant oils and selenium enriched yeast on broiler meat composition, antioxidation- and sensory parameters. Four different wheat-based dietary treatments supplemented with 5% rapeseed oil or 4% rapeseed oil plus 1% linseed oil, and either 0.50 mg selenium or 0.84 mg selenium (organic form per kg diet was fed to newly hatched broilers for 22 days. Results The different dietary treatments gave distinct different concentrations of selenium and fatty acids in thigh muscle; one percent linseed oil in the diet increased the concentration of the omega-3 fatty acids 18:3, 20:5 and 22:5, and 0.84 mg selenium per kg diet gave muscle selenium concentration at the same level as is in fish muscle (0.39 mg/kg muscle. The high selenium intake also resulted in increased concentration of the long-chain omega-3 fatty acids EPA (20:5, DPA (22:5 and DHA (22:6, thus it may be speculated if high dietary selenium might have a role in increasing the concentration of EPA, DPA and DHA in tissues after intake of plant oils contning omega-3 fatty acids. Conclusion Moderate modifications of broiler feed may give a healthier broiler meat, having increased content of selenium and omega-3 fatty acids. High intakes of selenium (organic form may increase the concentration of very long-chain omega-3 fatty acids in muscle.

  2. SLUDGE ORGANICS BIOAVAILABILITY

    Science.gov (United States)

    Concern over the bioavailability of toxic organics that can occur in municipal sludges threatens routine land application of sludge. vailable data, however, show that concentrations of priority organics in normal sludges are low. ludges applied at agronomic rates yield chemical c...

  3. Interaction between micronutrients, their impact on bioavailability and significance in nutrition intervention. Highlights and achievements

    International Nuclear Information System (INIS)

    Micronutrient deficiencies are of greatest public health significance in Sri Lanka, and as such investigating an effective programme for the prevention is urgently required. Scientific objectives: To study possible interactions between micronutrients (iron and zinc) that may interfere with utilization by a double blind randomized control trial; To determine the bioavailability of iron and zinc using stable isotope methodology; To study iron and zinc status in patients diagnosed as having endemic goitre; To assess the selenium status among the preadolescents

  4. Selenium Nanoparticles Prepared from Reverse Microemulsion Process

    Institute of Scientific and Technical Information of China (English)

    Ming Zhu LIU; Sheng Yi ZHANG; Yu Hua SHEN; Ming Liang ZHANG

    2004-01-01

    Selenium nanoparticles were prepared by a reverse microemulsion system. Sodium selenosulfate was used as selenium source. The results showed that hydrochloric acid concentration and reaction temperature had great influence on the morphology of products. The crystalline selenium nanowires and amorphous selenium nanorods were obtained in given condition.

  5. Selenium protection from cadmium and chromium poisoning

    International Nuclear Information System (INIS)

    The interaction of selenium with cadmium and chromium was studied in 168 chicken-broilers (DWCxWR) divided into four equal groups. Eight-week old control animals received an intravenous dose of /sup 115m/Cd Chloride 370 KBq/Kg (Group I), or 51Cr Chloride 370 KBq/Kg (Group II). The kinetics of these isotopes were studied by scintillation spectrometry (NaI/TI) carried out for whole blood, plasma, plasma proteins, urine, feces and homogenates of all organs at various time intervals. Animals in Groups III and IV received eight subcutaneous doses of sodium selenate (5ug) at 8-week intervals prior to /sup 115m/Cd or 51Cr. The kinetics of these elements were studied as in the previous two groups. It was found that selenium affected those kinetics in two ways: (a) by increasing the excretion of Cd by 11 +/- 3% (P < 0.001) and that of Cr by 7 +/- 1% (P < 0.001); and (b) by favoring redistribution of those elements, with significant (P < 0.001) reductions in liver, endocrine glands and kidney and increases (P < 0.01) in bone. The study suggests that selenium protects the animals' vital organs from environmental pollutants, such as cadmium and chromium

  6. Nanosized Selenium: A Novel Platform Technology to Prevent Bacterial Infections

    Science.gov (United States)

    Wang, Qi

    As an important category of bacterial infections, healthcare-associated infections (HAIs) are considered an increasing threat to the safety and health of patients worldwide. HAIs lead to extended hospital stays, contribute to increased medical costs, and are a significant cause of morbidity and mortality. In the United States, infections encountered in the hospital or a health care facility affect more than 1.7 million patients, cost 35.7 billion to 45 billion, and contribute to 88,000 deaths in hospitals annually. The most conventional and widely accepted method to fight against bacterial infections is using antibiotics. However, because of the widespread and sometimes inappropriate use of antibiotics, many strains of bacteria have rapidly developed antibiotic resistance. Those new, stronger bacteria pose serious, worldwide threats to public health and welfare. In 2014, the World Health Organization (WHO) reported antibiotic resistance as a global serious threat that is no longer a prediction for the future but is now reality. It has the potential to affect anyone, of any age, in any country. The most effective strategy to prevent antibiotic resistance is minimizing the use of antibiotics. In recent years, nanomaterials have been investigated as one of the potential substitutes of antibiotics. As a result of their vastly increased ratio of surface area to volume, nanomaterials will likely exert a stronger interaction with bacteria which may affect bacterial growth and propagation. A major concern of most existing antibacterial nanomaterials, like silver nanoparticles, is their potential toxicity. But selenium is a non-metallic material and a required nutrition for the human body, which is recommended by the FDA at a 53 to 60 μg daily intake. Nanosized selenium is considered to be healthier and less toxic compared with many metal-based nanomaterials due to the generation of reactive oxygen species from metals, especially heavy metals. Therefore, the objectives of

  7. Selenium and immune functions in humans.

    OpenAIRE

    Arvilommi, H; Poikonen, K; Jokinen, I; Muukkonen, O; Räsänen, L.; Foreman, J; Huttunen, J K

    1983-01-01

    Earlier animal experiments have shown that selenium depletion may decrease immune functions. In this human study, 40 volunteers from a population with low serum selenium concentrations were supplemented with selenium or placebo for 11 weeks. Blood samples were drawn at intervals for analysis of selenium status and immune function. At the end of the supplementation period, plasma selenium levels were 74 ng/ml in the placebo group and 169 ng/ml in the supplemented group. The improvement in sele...

  8. Biochemistry of Selenium in Pariette Wetlands, Utah

    OpenAIRE

    Jones, Colleen P.

    2014-01-01

    The Pariette Wetlands was constructed to provide wildlife habitat in an arid environment. Elevated levels of selenium (Se) have been detected in water, soil, and biota. Selenium concentrations have ranged from below detection limit to four times the water quality criterium limit. Here we report on three interrelated research topics: 1) selenium mass balance and flux in water, 2) selenium accumulation, concentration and volatilization of water and plant tissues; and 3) selenium sorption by upl...

  9. Blood selenium content determination by X-ray fluorescence

    International Nuclear Information System (INIS)

    The presence of some elements in small amounts (traces) in the human body is of foremost importance for the prevention and treatment of several diseases. It has been recently shown that traces of selenium in blood are closely related to the occurrence of miotonic distrophy, a muscular disease that is affecting a significant percentage of the population. This work describes a simple procedure to determine selenium in human blood serum by energy dispersive X-ray fluorescence analysis. Final quantification is achieved through the addition of titanium as an internal standard. (Author)

  10. Bioavailability enhancement studies of amoxicillin with Nigella

    OpenAIRE

    Ali, Babar; Amin, Saima; Ahmad, Javed; Ali, Abuzer; Ali, Mohd; Showkat R Mir

    2012-01-01

    Background & objectives: Nigella sativa Linn. is extensively used in the Indian diasporas as spice, which may interact with co-administered drugs and affect their intestinal availability. The purpose of this study was to investigate the effect of Nigella on bioavailability of amoxicillin in animal model. Methods: Everted rat intestinal sacs were used for in vitro experiment to study the transfer of amoxicillin across the gut. Amoxicillin (6 mg/ml) was co-infused with 3 and 6 mg of methanol an...

  11. Bioavailability of coffee polyphenols: focus on dose- and structure response

    OpenAIRE

    Erk, Thomas

    2014-01-01

    A positive affection of human health by nutrition is of high interest, especially for bioactive compounds which are consumed daily in high amounts. This is the case for chlorogenic acids (CGA) ingested by coffee. This molecule class is associated with several possible beneficial health effects observed in vitro that strongly depend on their bioavailability. So far factors influencing bioavailability of CGA such as dose, molecule structure and site of absorption haven´t been investigated suffi...

  12. Selenium semiconductor core optical fibers

    Directory of Open Access Journals (Sweden)

    G. W. Tang

    2015-02-01

    Full Text Available Phosphate glass-clad optical fibers containing selenium (Se semiconductor core were fabricated using a molten core method. The cores were found to be amorphous as evidenced by X-ray diffraction and corroborated by Micro-Raman spectrum. Elemental analysis across the core/clad interface suggests that there is some diffusion of about 3 wt % oxygen in the core region. Phosphate glass-clad crystalline selenium core optical fibers were obtained by a postdrawing annealing process. A two-cm-long crystalline selenium semiconductor core optical fibers, electrically contacted to external circuitry through the fiber end facets, exhibit a three times change in conductivity between dark and illuminated states. Such crystalline selenium semiconductor core optical fibers have promising utility in optical switch and photoconductivity of optical fiber array.

  13. Selenium semiconductor core optical fibers

    International Nuclear Information System (INIS)

    Phosphate glass-clad optical fibers containing selenium (Se) semiconductor core were fabricated using a molten core method. The cores were found to be amorphous as evidenced by X-ray diffraction and corroborated by Micro-Raman spectrum. Elemental analysis across the core/clad interface suggests that there is some diffusion of about 3 wt % oxygen in the core region. Phosphate glass-clad crystalline selenium core optical fibers were obtained by a postdrawing annealing process. A two-cm-long crystalline selenium semiconductor core optical fibers, electrically contacted to external circuitry through the fiber end facets, exhibit a three times change in conductivity between dark and illuminated states. Such crystalline selenium semiconductor core optical fibers have promising utility in optical switch and photoconductivity of optical fiber array

  14. Selenium Metabolism in Cancer Cells: The Combined Application of XAS and XFM Techniques to the Problem of Selenium Speciation in Biological Systems

    OpenAIRE

    Harris, Hugh H; Stefan Vogt; Witting, Paul K.; Aitken, Jade B.; Lydia Finney; Weekley, Claire M.

    2013-01-01

    Determining the speciation of selenium in vivo is crucial to understanding the biological activity of this essential element, which is a popular dietary supplement due to its anti-cancer properties. Hyphenated techniques that combine separation and detection methods are traditionally and effectively used in selenium speciation analysis, but require extensive sample preparation that may affect speciation. Synchrotron-based X-ray absorption and fluorescence techniques offer an alternative appro...

  15. Trace Element Analysis of Selenium

    International Nuclear Information System (INIS)

    The present thesis divided into four chapters as follows:Chapter (1):This chapter contains an introduction on different oxidation states of organic and inorganic species for selenium in environmental and biological samples, the process for separation of selenium from these samples and the importance of selenium as a component for these samples. Also gives notes about the techniques which are used in the elemental analysis for selenium species and the detection limits for selenium in these techniques, selenium species in human body and the importance of these species in protecting the body from the different types of cancer and the sources of selenium in environmental samples (soil and water) and distribution levels of selenium in these samples.Chapter (2):This chapter is divided into two parts :The first part deals with the sample collection process for environmental samples (underground water, soil) and the wet digestion ( microwave digestion ) process of soil samples. It also contains the theory of work of the closed microwave digestion system.The second part contains detailed information concerning the theoretical considerations of the used analytical techniques. These techniques include Hydride generation - Atomic Absorption Spectrometer (HG-AAS), Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and Neutron Activation Analysis (NAA).Chapter (3): This chapter includes the methods of sampling, sample preparation, and sample digesition. The measures of quality assurance are disscused in this chapter. It describes in details the closed microwave digestion technique and the analytical methods used in this study which are present in Central Laboratory for Elemental and Isotopic Analysis (CLEIA) and the Egypt Second Research Reactor (ETRR-2). The described techniques are Atomic Absorption Spectrometer (AAS 6 vario, Analytical Jena GmbH, Germany), JMS-PLASMAX2 Mass Spectrometer (ICP-MS) and the Egypt Second Research Reactor (NAA).

  16. Bioavailability of zinc, copper, and manganese from infant diets

    International Nuclear Information System (INIS)

    A series of trace element absorption experiments were performed using the Sprague-Dawley suckling rat put and infant rhesis monkey (Macaca mulatta) with extrinsic radiolabeling to assess the bioavailability of Zn, Cu, and Mn from infant diets and to examine specific factors that affect absorption of these essential nutrients. Bioavailability of Cu as assessed by 6 h liver uptake (% of 64Cu dose) was highest from human milk and cow milk based formula and significantly lower from cow milk and soy based formula. Copper bioavailability from infant cereal products as assessed by whole body uptake (% of 64Cu dose) in d 20 rats, 9 h postintubation, was low compared to the bioavailability from cow milk or human milk alone. 65Zn uptake in d 20 rats, 9 h postintubation, was significantly lower from cereals fed alone or in combination with cow or human milk as compared to the uptake from the milks fed alone. Zn bioavailability varied among cereal diets, (lowest from cereals containing phytate and highest from cereal/fruit products). Mn bioavailability from infant diets was assessed using a modified suckling rat pup model. Bioavailability (24 h whole body retention of 54Mn) was high from all milks and commercial formulas tested

  17. Micronutrient bioavailability research priorities.

    Science.gov (United States)

    Casgrain, Amélie; Collings, Rachel; Harvey, Linda J; Boza, Julio J; Fairweather-Tait, Susan J

    2010-05-01

    A micronutrient bioavailability workshop, which involved international experts and members of the scientific community and the food industry, with interactive breakout sessions based on synectics principles, was organized by the International Life Sciences Institute Europe Addition of Nutrients to Food Task Force and the European Commission Network of Excellence European Micronutrient Recommendations Aligned. After presentations by experts, a series of "challenge statements" was discussed. The aim was to address topical issues, in particular those that linked bioavailability with the derivation of micronutrient requirements and dietary recommendations, to identify gaps in knowledge and to consider research priorities. Several generic research priorities were identified, including improving the quality of dietary surveys/food composition tables, the need for more metabolic studies that use stable isotopes and high-quality longer-term interventions, and the development of multifactorial mathematical models. Among the common recurrent factors identified as important were polymorphisms/genotype, consideration of the whole diet, chemical form of the micronutrient, and the determination of physiologic requirements. The involvement of all participants in the structured discussions ensured a broad overview of current knowledge, state-of-the-art research, and consideration of priorities for future research. PMID:20200267

  18. Toxicity of selenium and other elements in food organisms to razorback sucker larvae.

    Science.gov (United States)

    Hamilton, Steven J; Holley, Kathy M; Buhl, Kevin J; Bullard, Fern A; Weston, L Ken; McDonald, Susan F

    2002-09-24

    Elevated selenium concentrations documented in water, sediment, and biota in irrigation drain water studies by U.S. Department of the Interior agencies and academia have raised concerns that selenium may be adversely affecting endangered fish in the upper Colorado River basin. The objective of the study was to determine the effects on endangered razorback sucker (Xyrauchen texanus) larvae from exposure to selenium and other trace elements in water and zooplankton collected from sites adjacent to the Colorado River near Grand Junction, CO. A 30-day study was initiated with 5-day-old larvae exposed in a 4 x 4 factor experiment with four food and four water treatments, and the biological endpoints measured were survival, growth, development, and whole-body residues of selenium. Mean selenium concentration in reference water (24-Road) was or=4.6 microg/g in food organisms adversely affected the survival of razorback sucker larvae. The onset of mortality in larvae exposed to food and water from Walter Walker seemed delayed compared to mortality in larvae exposed to food and water from Horsethief, which has been observed in two other studies. Elevated arsenic in one food source seemed to interact with selenium to reduce the toxic effects of selenium. PMID:12127741

  19. Deletion of Selenoprotein P Upregulates Urinary Selenium Excretion and Depresses Whole-body Selenium Content

    OpenAIRE

    Raymond F Burk; Hill, Kristina E.; Motley, Amy K.; Austin, Lori M.; Norsworthy, Brooke K.

    2006-01-01

    Deletion of the mouse selenoprotein P gene (Sepp1) lowers selenium concentrations in many tissues. We examined selenium homeostasis in Sepp1−/− and Sepp1+/+ mice to assess the mechanism of this. The liver produces and exports selenoprotein P, which transports selenium to peripheral tissues, and urinary selenium metabolites, which regulate whole-body selenium. At intakes of selenium near the nutritional requirement, Sepp1−/− mice had whole-body selenium concentrations 72 to 75% of Sepp1+/+ mic...

  20. The Content and Bioavailability of Mineral Nutrients of Selected Wild and Traditional Edible Plants as Affected by Household Preparation Methods Practiced by Local Community in Benishangul Gumuz Regional State, Ethiopia.

    Science.gov (United States)

    Hailu, Andinet Abera; Addis, Getachew

    2016-01-01

    Edible parts of some wild and traditional vegetables used by the Gumuz community, namely, Portulaca quadrifida, Dioscorea abyssinica, Abelmoschus esculentus, and Oxytenanthera abyssinica, were evaluated for their minerals composition and bioavailability. Mineral elements, namely, Ca, Fe, Zn, and Cu, were analyzed using Shimadzu atomic absorption spectrophotometer. Effects of household processing practices on the levels of mineral elements were evaluated and the bioavailability was predicted using antinutrient-mineral molar ratios. Fe, Zn, Ca, Cu, P, Na, and K level in raw edible portions ranged in (0.64 ± 0.02-27.0 ± 6.24), (0.46 ± 0.02-0.85 ± 0.02), (24.49 ± 1.2-131.7 ± 8.3), (0.11 ± 0.01-0.46 ± 0.04), (39.13 ± 0.34-57.27 ± 0.94), (7.34 ± 0.42-20.42 ± 1.31), and (184.4 ± 1.31-816.3 ± 11.731) mg/100 g FW, respectively. Although statistically significant losses in minerals as a result of household preparation practices were observed, the amount of nutrients retained could be valuable especially in communities that have limited alternative sources of these micronutrients. The predicted minerals' bioavailability shows adequacy in terms of calcium and zinc but not iron. PMID:26981523

  1. Selenium deposition kinetics of different selenium sources in muscle and feathers of broilers.

    Science.gov (United States)

    Couloigner, Florian; Jlali, Maamer; Briens, Mickael; Rouffineau, Friedrich; Geraert, Pierre-André; Mercier, Yves

    2015-11-01

    The objective of this study was to determine selenium (Se) deposition kinetics in muscles and feathers of broilers in order to develop a rapid method to compare bioavailability of selenium sources. Different Se sources such as 2-hydroxy-4-methylselenobutanoic acid (HMSeBA, SO), sodium selenite (SS) and seleno-yeast (SY) were compared for their kinetics on Se deposition in muscles and feathers in broiler chicks from 0 to 21 d of age. A total of 576 day-old broilers were divided into four treatments with 8 replicates of 18 birds per pen. The diets used in the experiment were a negative control (NC) not supplemented with Se and 3 diets supplemented with 0.2 mg Se/kg as SS, SY or SO. Total Se content in breast muscle and feathers were assessed on days 0, 7, 14 and 21. At 7 d of age, SO increased muscle Se content compared to D0 (P organic Se sources maintained (SY) or increased (SO) (P < 0.05) breast muscle Se concentration compared to hatch value whereas inorganic source (SS) or non-supplemented group (NC) showed a significant decrease in tissue Se concentration (P < 0.05). At D21, Se contents of muscle and feathers were highly correlated (R(2) = 0.927; P < 0.0001). To conclude, these results indicate that efficiency of different Se sources can be discriminated through a 7 d using muscle Se content in broiler chickens. Muscle and feathers Se contents were highly correlated after 21 days. Also feather sampling at 21 days of age represents a reliable and non-invasive procedure for Se bioefficacy comparison. PMID:26500270

  2. Geiten krijgen meestal te veel selenium

    NARCIS (Netherlands)

    Smolders, E.A.A.; Govaerts, W.; Eekeren, van N.J.M.

    2010-01-01

    Geiten gaan efficiënt om met selenium. Mede daardoor zijn de bloedwaardes voor selenium bij geiten vaak hoog, en soms te hoog, zo bleek na bloedonderzoek op dertien biologische geitenbedrijven binnen het project Biogeit. Te veel selenium is schadelijk voor geiten.

  3. Study on selenium extraction from anode slime

    Institute of Scientific and Technical Information of China (English)

    GU; Heng

    2005-01-01

    Taking a copper anode slime as the raw material, a novel process for selenium extraction was studied. The primary selenium recovery can reach above 88.5 % and the quality index of selenium product can be up to 99.5 %. The economic benefit resulted is remarkable and environment has been protected.

  4. The effect of selenium on physiological and biochemical characteristics of Lemna minor

    OpenAIRE

    Okoren, Tina

    2013-01-01

    Selenium is an element which can be toxic at certain concentrations. Selenium in wastewaters can contaminate surface water and groundwater, accumulate in certain aquatic plants and can lead to poisoning of aquatic and terrestrial organisms. We tried to establish which concentrations of selenite are beneficial for growth of common duckweed and how different selenite concentrations affect selected physiological and biochemical characteristics of common duckweed. We monitored respiratory potenti...

  5. Selenium content of vegetal foodstuffs in the Federal Republic of Germany

    Energy Technology Data Exchange (ETDEWEB)

    Hofsommer, H.J.; Bielig, H.J.

    1982-02-01

    We are quoting selenium contents in foodstuffs as cited in literature and are discussing them. The survey of published selenium contents in vegetal foodstuffs over the last 20 years reveals that diverging values must mainly be attributed to the site involved. Results of investigations on approximately 800 samples of different fruits and vegetables in the Federal Republic of Germany have shown that fruit does not contain any selenium and vegetables but very minor quantities. Contents differ widely with the individual types of vegetables. Regional variances could not be determined. It can therefore be assumed that the Federal Republic of Germany must be counted among the earth's low-selenium areas. If and how far there is possibly already an undersupply prevailing in this essential trace element - particularly in infant and toddler feeding - will require further supporting data and physiological investigations. Technological factors in the industrial manufacture of fruit and vegetable products are not affecting the selenium content. A specific strain on the environment through selenium cannot be determined at the moment and is not expected for the next few years either, since even sites in heavily endangered environments do not exhibit selenium contents deviating from the average in the individual fruits and vegetables.

  6. Effect of selenium on uranium biosorption

    International Nuclear Information System (INIS)

    The effects of selenium on uranium biosorption were examined using 67 microorganisms (17 bacteria, 19 actinomycetes, 18 fungi, and 13 yeasts). The growth suppression by selenium in the medium was observed in most of the microorganisms tested. The amounts of selenium taken up in microbial cells differ with different species and groups of microorganisms. The marked enhancement of uranium adsorbing ability by Se-loading was only found in yeasts, such as Candida utilis. The amounts of uranium adsorbed by the cells were increased with increasing selenium in the cells. Thus, it is assumed that the selenium in the cells will play an important role in uranium binding. (author)

  7. Potassium Intake, Bioavailability, Hypertension, and Glucose Control.

    Science.gov (United States)

    Stone, Michael S; Martyn, Lisa; Weaver, Connie M

    2016-01-01

    Potassium is an essential nutrient. It is the most abundant cation in intracellular fluid where it plays a key role in maintaining cell function. The gradient of potassium across the cell membrane determines cellular membrane potential, which is maintained in large part by the ubiquitous ion channel the sodium-potassium (Na+-K+) ATPase pump. Approximately 90% of potassium consumed (60-100 mEq) is lost in the urine, with the other 10% excreted in the stool, and a very small amount lost in sweat. Little is known about the bioavailability of potassium, especially from dietary sources. Less is understood on how bioavailability may affect health outcomes. Hypertension (HTN) is the leading cause of cardiovascular disease (CVD) and a major financial burden ($50.6 billion) to the US public health system, and has a significant impact on all-cause morbidity and mortality worldwide. The relationship between increased potassium supplementation and a decrease in HTN is relatively well understood, but the effect of increased potassium intake from dietary sources on blood pressure overall is less clear. In addition, treatment options for hypertensive individuals (e.g., thiazide diuretics) may further compound chronic disease risk via impairments in potassium utilization and glucose control. Understanding potassium bioavailability from various sources may help to reveal how specific compounds and tissues influence potassium movement, and further the understanding of its role in health. PMID:27455317

  8. Potassium Intake, Bioavailability, Hypertension, and Glucose Control

    Directory of Open Access Journals (Sweden)

    Michael S. Stone

    2016-07-01

    Full Text Available Potassium is an essential nutrient. It is the most abundant cation in intracellular fluid where it plays a key role in maintaining cell function. The gradient of potassium across the cell membrane determines cellular membrane potential, which is maintained in large part by the ubiquitous ion channel the sodium-potassium (Na+-K+ ATPase pump. Approximately 90% of potassium consumed (60–100 mEq is lost in the urine, with the other 10% excreted in the stool, and a very small amount lost in sweat. Little is known about the bioavailability of potassium, especially from dietary sources. Less is understood on how bioavailability may affect health outcomes. Hypertension (HTN is the leading cause of cardiovascular disease (CVD and a major financial burden ($50.6 billion to the US public health system, and has a significant impact on all-cause morbidity and mortality worldwide. The relationship between increased potassium supplementation and a decrease in HTN is relatively well understood, but the effect of increased potassium intake from dietary sources on blood pressure overall is less clear. In addition, treatment options for hypertensive individuals (e.g., thiazide diuretics may further compound chronic disease risk via impairments in potassium utilization and glucose control. Understanding potassium bioavailability from various sources may help to reveal how specific compounds and tissues influence potassium movement, and further the understanding of its role in health.

  9. Potassium Intake, Bioavailability, Hypertension, and Glucose Control

    Science.gov (United States)

    Stone, Michael S.; Martyn, Lisa; Weaver, Connie M.

    2016-01-01

    Potassium is an essential nutrient. It is the most abundant cation in intracellular fluid where it plays a key role in maintaining cell function. The gradient of potassium across the cell membrane determines cellular membrane potential, which is maintained in large part by the ubiquitous ion channel the sodium-potassium (Na+-K+) ATPase pump. Approximately 90% of potassium consumed (60–100 mEq) is lost in the urine, with the other 10% excreted in the stool, and a very small amount lost in sweat. Little is known about the bioavailability of potassium, especially from dietary sources. Less is understood on how bioavailability may affect health outcomes. Hypertension (HTN) is the leading cause of cardiovascular disease (CVD) and a major financial burden ($50.6 billion) to the US public health system, and has a significant impact on all-cause morbidity and mortality worldwide. The relationship between increased potassium supplementation and a decrease in HTN is relatively well understood, but the effect of increased potassium intake from dietary sources on blood pressure overall is less clear. In addition, treatment options for hypertensive individuals (e.g., thiazide diuretics) may further compound chronic disease risk via impairments in potassium utilization and glucose control. Understanding potassium bioavailability from various sources may help to reveal how specific compounds and tissues influence potassium movement, and further the understanding of its role in health. PMID:27455317

  10. Selenium in pregnancy: is selenium an active defective ion against environmental chemical stress?

    International Nuclear Information System (INIS)

    Transportation of selenium from mother to fetus and its possible effects on mother's zinc, copper, cadmium, and mercury levels were studied together during the first trimester and at term in 216 mothers. Mothers came from three geographical places with different selenium intakes. The role of selenium as a biomarker for the vital function was estimated by studying the associations between tissue or blood selenium content and placental cytochrome P450 enzyme activities and the newborn's birth weight. Regardless of the selenium intake of the mothers, higher concentrations were found in the cord blood than in mother's blood reflecting active transportation of selenium to the fetus. Active smoking was associated with higher placental selenium concentrations like it is associated with higher placental zinc concentrations. When the cadmium concentrations were high in placenta, as in smokers, the transfer of selenium from blood to placenta was increased, decreasing the selenium levels in blood. On the other hand, the high selenium concentrations in blood were connected to lower cadmium concentrations in placenta also in nonsmokers. Selenium had correlations with copper and zinc. ECOD activity in placental tissue, mercury in mothers' hair, mothers' age, and selenium concentrations in cord blood and placental selenium all seem to have connections with xenobiotic-metabolizing enzymes linked effects among mothers. These data suggest that selenium has an active role in the mother's defense systems against the toxicity of environmental pollutants and the constituents of cigarette smoke

  11. JV Task - 116 Selenium's Role in the Seafood Safety Issue

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas Ralston; Laura Raymond

    2009-03-30

    Continuing studies under these three funded projects - (JV Task 77 The Health Implications of the Mercury-Selenium Interaction, JV Task 96 Investigating the Importance of the Mercury-Selenium Interaction, and JV Task 116 Selenium's Role in the Seafood Safety Issue) - were performed to determine the effects of different levels of dietary mercury and selenium on the growth and development of test animals, and related tissue analyses, to understand the protective benefits of dietary selenium in reference to low-level exposure to mercury. Maternal exposure to methylmercury from seafood has been found to cause neurodevelopmental harm in children. However, significant nutritional benefits will be lost if fish consumption is needlessly avoided. The results of these studies support the hypothesis that intracellular Se itself is the physiologically important biomolecule and that the harm of mercury toxicity arises when Hg abundance becomes great enough to bind a significant portion of intracellular Se in vulnerable tissues such as the brain. Formation of HgSe limits bioavailability of Se for synthesis of Se-dependent enzymes, particularly in brain tissues. When production of these enzymes is impaired, the loss of their numerous essential functions results in the signs and symptoms of Hg toxicity. The finding that one mole of Se protects against many moles of Hg indicates that its beneficial effect is not due to sequestration of mercury as HgSe but rather due to the biological activity of the Se. Therefore, the selenium content of seafoods must be considered along with their methylmercury contents in evaluating the effect of dietary exposure to mercury.

  12. Selenium, apoptosis, and colorectal adenomas.

    OpenAIRE

    Connelly-Frost, Alexandra; Poole, Charles; Satia, Jessie A.; Kupper, Lawrence L.; Millikan, Robert C.; Sandler, Robert S.

    2006-01-01

    Dietary modulation of carcinogenesis-related pathwaysDietary item or component studied:seleniumPathways studied:apoptosisStudy type (in vitro, animals, humans): humansStudy design (if human):cross-sectional studyStudy size (if human):803 participantsTissue/biological material/sample size: serum, 2 colon biopsiesMode of exposure (if in vivo) (acute, chronic, root of exposure):dietary & lifestyle questionnairesImpact on pathway (including dose-response):for 50-120 μgr/l selenium Pe~0.5-0.3For ...

  13. Selenium in Cattle: A Review

    OpenAIRE

    Youcef Mehdi; Isabelle Dufrasne

    2016-01-01

    This review article examines the role of selenium (Se) and the effects of Se supplementation especially in the bovine species. Selenium is an important trace element in cattle. Some of its roles include the participation in the antioxidant defense the cattle farms. The nutritional requirements of Se in cattle are estimated at 100 μg/kg DM (dry matter) for beef cattle and at 300 μg/kg DM for dairy cows. The rations high in fermentable carbohydrates, nitrates, sulfates, calcium or hydrogen cyan...

  14. Selenium Content in Seafood in Japan

    Directory of Open Access Journals (Sweden)

    Haruka Iida

    2013-01-01

    Full Text Available Selenium is an essential micronutrient for humans, and seafood is one of the major selenium sources, as well as red meat, grains, eggs, chicken, liver and garlic. A substantial proportion of the total amount of selenium is present as selenium containing imidazole compound, selenoneine, in the muscles of ocean fish. In order to characterize the selenium content in seafood, the total selenium levels were measured in the edible portions of commercially important fish and shellfish species. Among the tested edible portions, alfonsino muscle had the highest selenium levels (concentration of 1.27 mg/kg tissue. High levels of selenium (1.20–1.07 mg/kg were also found in the salted ovary products of mullet and Pacific herring. In other fish muscles, the selenium levels ranged between 0.12 and 0.77 mg/kg tissue. The selenium levels were closely correlated with the mercury levels in the white and red muscles in alfonsino. The selenium content in spleen, blood, hepatopancreas, heart, red muscle, white muscle, brain, ovary and testis ranged between 1.10 and 24.8 mg/kg tissue in alfonsino.

  15. Bioaccumulation and toxicity of selenium compounds in the green alga Scenedesmus quadricauda

    Directory of Open Access Journals (Sweden)

    Doucha Jiří

    2009-05-01

    Full Text Available Abstract Background Selenium is a trace element performing important biological functions in many organisms including humans. It usually affects organisms in a strictly dosage-dependent manner being essential at low and toxic at higher concentrations. The impact of selenium on mammalian and land plant cells has been quite extensively studied. Information about algal cells is rare despite of the fact that they could produce selenium enriched biomass for biotechnology purposes. Results We studied the impact of selenium compounds on the green chlorococcal alga Scenedesmus quadricauda. Both the dose and chemical forms of Se were critical factors in the cellular response. Se toxicity increased in cultures grown under sulfur deficient conditions. We selected three strains of Scenedesmus quadricauda specifically resistant to high concentrations of inorganic selenium added as selenite (Na2SeO3 – strain SeIV, selenate (Na2SeO4 – strain SeVI or both – strain SeIV+VI. The total amount of Se and selenomethionine in biomass increased with increasing concentration of Se in the culturing media. The selenomethionine made up 30–40% of the total Se in biomass. In both the wild type and Se-resistant strains, the activity of thioredoxin reductase, increased rapidly in the presence of the form of selenium for which the given algal strain was not resistant. Conclusion The selenium effect on the green alga Scenedesmus quadricauda was not only dose dependent, but the chemical form of the element was also crucial. With sulfur deficiency, the selenium toxicity increases, indicating interference of Se with sulfur metabolism. The amount of selenium and SeMet in algal biomass was dependent on both the type of compound and its dose. The activity of thioredoxin reductase was affected by selenium treatment in dose-dependent and toxic-dependent manner. The findings implied that the increase in TR activity in algal cells was a stress response to selenium cytotoxicity

  16. Effect of selenium on its content in milk and performance of dairy cows in ecological farming

    Directory of Open Access Journals (Sweden)

    Pavel Horký

    2015-08-01

    Full Text Available Currently, the ecological farming is increasingly spread in the European Union. The aim of this relatively young farming method is a friendly approach to agricultural production with an emphasis to deliver healthy raw materials and food to final consumer. Selenium is included in an essential trace micronutrients which are necessary for the proper process of physiological reactions. It is a part of glutathione peroxidase, which is a powerful antioxidant. At present,  selenium-deficiency can occur in feed and food in central Europe. Selenium deficiency is one cause of the higher occurrence of cardiovascular diseases. The aim of the experiment was to study whether the addition of selenium to the diet of dairy cows in ecological farming can increase its concentration in milk and affect quantitative (milk yield and quality (content of protein, fat, lactose, somatic cells and urea milk indicators. The experiment included twenty cows of Holstein breed. The first experimental group of cows (n = 10 was fed with selenium in an amount of 0.3 mg.kg-1 (as selenomethionine in the feed dose. The control group (n = 10 was not fed with the increased selenium in the feed dose. The basic feed dose contained 0.17 mg of Se/kg in the diet. For dairy cows, daily intake was of 20.5 kg of dry matter feed. The duration of the experiment was set at 45 days. The selenium concentration in milk was measured from 0.13 to 0.15 µg.mL-1 in the experimental group of cows during the evaluation. The control group of cows without the addition of selenium to the diet showed a selenium concentration below the detection limit. During the experiment, milk yield, lactose, fat and protein were not affected. A significant decrease (p <0.05 of somatic cells by 58% occurred in milk in the experimental group. The amount of urea was significantly lower in both groups in the experimental (by 52%; p <0.05 and control (50%; p <0.05. These results show that the addition of selenium may increase

  17. Zinc bioavailability in the chick

    International Nuclear Information System (INIS)

    Methods for assessing zinc bioavailability were evaluated in the chick. A low-zinc chick diet was developed using rehydrated, spray-dried egg white autoclaved at 121 C for 30 min as the primary protein source. The relative bioavailability of zinc from soy flour and beef was determined by whole-body retention of extrinsic 65Zn, and in slope ratio assays for growth rate and tissue zinc. Compared to zinc carbonate added to an egg white-based diet, all methods gave similar estimates of approximately 100% zinc bioavailability for beef but estimates for soy flour varied widely. The slope ratio assay for growth rate gave the best estimate of zinc bioavailability for soy flour. True absorption, as measured by percent isotope retention from extrinsically labeled soy flour, was 47%

  18. Shedding Light on Selenium Biomineralization: Proteins Associated with Bionanominerals ▿

    OpenAIRE

    M. Lenz; Kolvenbach, B.; Gygax, B.; Moes, S; Corvini, P. F. X.

    2011-01-01

    Selenium reducing microorganisms produce elemental selenium nanoparticles with particular physico-chemical properties being due to an associated organic fraction. This study identified high affinity proteins being associated with such bionanominerals and with non-biogenic elemental selenium. Proteins with an anticipated functional role in selenium reduction, such as a metalloid reductase, were found associated with nanoparticles formed by one selenium respirer, Sulfurospirillum barnesii.

  19. Protection of cisplatin-induced spermatotoxicity, DNA damage and chromatin abnormality by selenium nano-particles

    Energy Technology Data Exchange (ETDEWEB)

    Rezvanfar, Mohammad Amin; Rezvanfar, Mohammad Ali [Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences (TUMS), Tehran (Iran, Islamic Republic of); Shahverdi, Ahmad Reza [Department of Pharmaceutical Biotechnology and Biotechnology Research Centre, Faculty of Pharmacy, TUMS, Tehran (Iran, Islamic Republic of); Ahmadi, Abbas [Department of Histology and Embryology, Faculty of Veterinary Medicine, Urmia University, Urmia (Iran, Islamic Republic of); Baeeri, Maryam; Mohammadirad, Azadeh [Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences (TUMS), Tehran (Iran, Islamic Republic of); Abdollahi, Mohammad, E-mail: mohammad.abdollahi@utoronto.ca [Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences (TUMS), Tehran (Iran, Islamic Republic of)

    2013-02-01

    Cisplatin (CIS), an anticancer alkylating agent, induces DNA adducts and effectively cross links the DNA strands and so affects spermatozoa as a male reproductive toxicant. The present study investigated the cellular/biochemical mechanisms underlying possible protective effect of selenium nano-particles (Nano-Se) as an established strong antioxidant with more bioavailability and less toxicity, on reproductive toxicity of CIS by assessment of sperm characteristics, sperm DNA integrity, chromatin quality and spermatogenic disorders. To determine the role of oxidative stress (OS) in the pathogenesis of CIS gonadotoxicity, the level of lipid peroxidation (LPO), antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) and peroxynitrite (ONOO) as a marker of nitrosative stress (NS) and testosterone (T) concentration as a biomarker of testicular function were measured in the blood and testes. Thirty-two male Wistar rats were equally divided into four groups. A single IP dose of CIS (7 mg/kg) and protective dose of Nano-Se (2 mg/kg/day) were administered alone or in combination. The CIS-exposed rats showed a significant increase in testicular and serum LPO and ONOO level, along with a significant decrease in enzymatic antioxidants levels, diminished serum T concentration and abnormal histologic findings with impaired sperm quality associated with increased DNA damage and decreased chromatin quality. Coadministration of Nano-Se significantly improved the serum T, sperm quality, and spermatogenesis and reduced CIS-induced free radical toxic stress and spermatic DNA damage. In conclusion, the current study demonstrated that Nano-Se may be useful to prevent CIS-induced gonadotoxicity through its antioxidant potential. Highlights: ► Cisplatin (CIS) affects spermatozoa as a male reproductive toxicant. ► Effect of Nano-Se on CIS-induced spermatotoxicity was investigated. ► CIS-exposure induces oxidative sperm DNA damage

  20. Oral bioavailability of moxifloxacin after Roux-en-Y gastric bypass surgery

    NARCIS (Netherlands)

    De Smet, Julie; Colin, Pieter; De Paepe, Peter; Ruige, Johannes; Batens, Helene; Van Nieuwenhove, Yves; Vogelaers, Dirk; Blot, Stijn; Van Bocxlaer, Jan; Van Bortel, Luc M.; Boussery, Koen

    2012-01-01

    Objectives: Roux-en-Y gastric bypass surgery is the most commonly performed procedure for the treatment of morbid obesity. This anatomical alteration may affect the absorption and consequently the bioavailability of oral drugs. This study aims to investigate the oral bioavailability of moxifloxacin

  1. Fracture Phenomena in Amorphous Selenium

    DEFF Research Database (Denmark)

    Lindegaard-Andersen, Asger; Dahle, Birgit

    1966-01-01

    Fracture surfaces of amorphous selenium broken in flexure at room temperature have been studied. The fracture velocity was found to vary in different regions of the fracture surface. Peculiar features were observed in a transition zone between fast and slower fracture. In this zone cleavage steps...

  2. Radiotracing selenium in bread-wheat seeds for a Se-biofortification program. An optimization study in seed enrichment

    International Nuclear Information System (INIS)

    Selenium (Se) is an essential micronutrient for human health, but its deficiency may affect at least one billion people worldwide. Plants and plant-derived products transfer the soil-uptaken Se to humans through the food chain, which is hardly enough when soils have been always poor or already exhausted in bioavailable Se species. Other than agronomic approaches for enhancing Se levels in cereals, such as soil and foliar supplements, seed enrichment may be viewed as an alternative Se-biofortification technique. This study addresses the protocol for preparing Se-enriched wheat seeds, with the specific purpose of optimizing the administration of Se to the seeds prior to sowing. The first step was to soak an amount of bread-wheat seeds in an active Se solution, made with irradiated [Na2O4Se], and then monitoring 75Se in periodically-retrieved samples from that original amount. To avoid losing Se to soil (after sowing), and, especially, to ensure that Se gets really absorbed into the seeds - and not just adsorbed onto them - the washing time of the seeds should be optimized as well. This was carried out by washing Se-treated seeds several times, until no significant amount of the radiotracer could be detected in the washing water. In what concerns the full optimization procedure, the overall results of the present study point to an optimum time of 48 h for soaking and 24 h for washing. (author)

  3. Study of trace elements remobilization from a contaminated soil: influence of soil organic compounds ageing on the selenium remobilization

    International Nuclear Information System (INIS)

    79Se is a high-life fission product presents in high-activity nuclear wastes. Selenium is often taking into account for health and environmental risk assessments as it is usually considered as a mobile and a toxic element. The terrestrial ecosystems are thought to be a potential reservoir of selenium. In this study, we specially studied how the associations between selenium and soil organic matter and/or microorganisms modify soils selenium mobility and partition (solid, liquid and gaseous). A particular attention was paid to the temporal evolution of the retention parameters, which remains one of the weak points of modeling especially for long term simulations (several tens-hundreds of thousand years). Methodology developed consists on a regular characterization of 3 soils samples pre-contaminated at a very week selenium concentration (2.2*10-9 g Se.g-1 soil) and incubated during 1.5 year in controlled conditions. The evolution of the organic status of the soil samples was established and well modeled (Roth C.). Alternatively, the selenium-OM associations did not present any significant modification with time affecting selenium mobility. The detailed study of selenium mobility showed that selenium sorption processes was poorly reversible (sorption Kd: 20-50 L.kg-1; desorption Kd: 100-500 L.kg-1), whatever the soil organic status. In addition, numerous transitory phenomenons were able to disturb the 'basic' behavior of selenium by increasing the amount of soluble selenium. We specially established that: (i) the use of phosphate fertilizers constituted the most important way of selenium remobilization leading to the release of 30-40 % of sorbed selenium in some extreme cases; (ii) the week selenium volatilization (∼ 0.2 % for 1.5 year of incubation) may constitute a significant biotic way of 79Se dispersion as soon as very long time scales are considered; (iii) the colloidal transport due to the soil microorganisms could also constituted a source of selenium

  4. Chemical Form of Selenium in Naturally Selenium-Rich Lentils (Lens Culinaris L.) From Saskatchewan

    Energy Technology Data Exchange (ETDEWEB)

    Thavarajah, D.; Vandenberg, A.; George, G.N.; Pickering, I.J.

    2009-06-04

    Lentils (Lens culinaris L.) are a source of many essential dietary components and trace elements for human health. In this study we show that lentils grown in the Canadian prairies are additionally enriched in selenium, an essential micronutrient needed for general well-being, including a healthy immune system and protection against cancer. Selenium K near-edge X-ray absorption spectroscopy (XAS) has been used to examine the selenium biochemistry of two lentil cultivars grown in various locations in Saskatchewan, Canada. We observe significant variations in total selenium concentration with geographic location and cultivar; however, almost all the selenium (86--95%) in these field-grown lentils is present as organic selenium modeled as selenomethionine with a small component (5--14%) as selenate. As the toxicities of certain forms of arsenic and selenium are antagonistic, selenium-rich lentils may have a pivotal role to play in alleviating the chronic arsenic poisoning in Bangladesh.

  5. The use of high-selenium yeast to raise selenium status: how does it measure up?

    OpenAIRE

    Rayman, MP

    2004-01-01

    Selenium-enriched yeast (Se-yeast) is a common form of selenium used to supplement dietary intake of this important trace mineral. However, its availability within the EU is under threat owing to concerns expressed by the EC Scientific Committee on Food that Se-yeast supplements are poorly characterised and could potentially cause the build up of selenium in tissues to toxic levels. This review examines the validity of these concerns. Diagrams of the biosynthesis and metabolism of selenium co...

  6. Toxicokinetics of selenium in the slider turtle, Trachemys scripta.

    Science.gov (United States)

    Dyc, Christelle; Far, Johann; Gandar, Frédéric; Poulipoulis, Anastassios; Greco, Anais; Eppe, Gauthier; Das, Krishna

    2016-05-01

    Selenium (Se) is an essential element that can be harmful for wildlife. However, its toxicity in poikilothermic amniotes, including turtles, remains poorly investigated. The present study aims at identifying selenium toxicokinetics and toxicity in juvenile slider turtles (age: 7 months), Trachemys scripta, dietary exposed to selenium, as selenomethionine SeMet, for eight weeks. Non-destructive tissues (i.e. carapace, scutes, skin and blood) were further tested for their suitability to predict selenium levels in target tissues (i.e. kidney, liver and muscle) for conservation perspective. 130 juvenile yellow-bellied slider turtles were assigned in three groups of 42 individuals each (i.e. control, SeMet1 and SeMet2). These groups were subjected to a feeding trial including an eight-week supplementation period SP 8 and a following 4-week elimination period EP 4 . During the SP8, turtles fed on diet containing 1.1 ± 0.04, 22.1 ± 1.0 and 45.0 ± 2.0 µg g(-1) of selenium (control, SeMet1 and SeMet2, respectively). During the EP4, turtles fed on non-supplemented diet. At different time during the trial, six individuals per group were sacrificed and tissues collected (i.e. carapace, scutes, skin, blood, liver, kidney, muscle) for analyses. During the SP8 (Fig. 1), both SeMet1 and SeMet2 turtles efficiently accumulated selenium from a SeMet dietary source. The more selenium was concentrated in the food, the more it was in the turtle body but the less it was removed from their tissues. Moreover, SeMet was found to be the more abundant selenium species in turtles' tissues. Body condition (i.e. growth in mass and size, feeding behaviour and activity) and survival of the SeMet1 and SeMet2 turtles seemed to be unaffected by the selenium exposure. There were clear evidences that reptilian species are differently affected by and sensitive to selenium exposure but the lack of any adverse effects was quite unexpected. Fig. 1 Design of the feeding trial. T, Time of

  7. Selenium in Oncology: From Chemistry to Clinics

    OpenAIRE

    Oliver Micke; Lutz Schomburg; Jens Buentzel; Klaus Kisters; Ralph Muecke

    2009-01-01

    The essential trace element selenium, which is a crucial cofactor in the most important endogenous antioxidative systems of the human body, is attracting more and more the attention of both laypersons and expert groups. The interest of oncologists mainly focuses in the following clinical aspects: radioprotection of normal tissues, radiosensitizing in malignant tumors, antiedematous effect, prognostic impact of selenium, and effects in primary and secondary cancer prevention. Selenium is a con...

  8. Selenium levels in breads from Sakarya, Turkey.

    Science.gov (United States)

    Gülfen, Mustafa

    2012-01-01

    Selenium (Se) is an important trace element for human and animal health. It accumulates in wheat and corn, which is consumed mostly as bread. The Turkish population consumes mainly white wheat, whole wheat (brown bread) and corn breads. In this study, samples of these breads were collected from six different bakeries in the city of Sakarya, and their selenium levels were determined by ICP-OES after a chemical digestion. It was found that average selenium levels in white wheat, whole wheat and corn breads were 1149, 1204 and 2023 µg/kg, respectively. The results are compared with daily recommended intake and upper tolerable levels for selenium. PMID:24779690

  9. Effect of intraperitoneal selenium administration on liver glycogen levels in rats subjected to acute forced swimming.

    Science.gov (United States)

    Akil, Mustafa; Bicer, Mursel; Kilic, Mehmet; Avunduk, Mustafa Cihat; Mogulkoc, Rasim; Baltaci, Abdulkerim Kasim

    2011-03-01

    There are a few of studies examining how selenium, which is known to reduce oxidative damage in exercise, influences glucose metabolism and exhaustion in physical activity. The present study aims to examine how selenium administration affects liver glycogen levels in rats subjected to acute swimming exercise. The study included 32 Sprague-Dawley type male rats, which were equally allocated to four groups: Group 1, general control; Group 2; selenium-supplemented control (6 mg/kg/day sodium selenite); Group 3, swimming control; Group 4, selenium-supplemented swimming (6 mg/kg/day sodium selenite). Liver tissue samples collected from the animals at the end of the study were fixed in 95% ethyl alcohol. From the tissue samples buried into paraffin, 5-µm cross-sections were obtained using a microtome, put on a microscope slide, and stained with PAS. Stained preparations were assessed using a Nikon Eclipse E400 light microscope. All images obtained with the light microscope were transferred to a PC and evaluated using Clemex PE 3.5 image analysis software. The highest liver glycogen levels were found in groups 1 and 2 (p exercise can be restored by selenium administration. It can be argued that physiological doses of selenium administration can contribute to performance. PMID:20340052

  10. Exploring the structural basis for selenium/mercury antagonism in Allium fistulosum

    Energy Technology Data Exchange (ETDEWEB)

    McNear, Jr., David H.; Afton, Scott E.; Caruso, Joseph A. (UCIN); (Kentucky)

    2012-12-10

    While continuing efforts are devoted to studying the mutually protective effect of mercury and selenium in mammals, few studies have investigated the mercury-selenium antagonism in plants. In this study, we report the metabolic fate of mercury and selenium in Allium fistulosum (green onion) after supplementation with sodium selenite and mercuric chloride. Analysis of homogenized root extracts via capillary reversed phase chromatography coupled with inductively coupled plasma mass spectrometry (capRPLC-ICP-MS) suggests the formation of a mercury-selenium containing compound. Micro-focused synchrotron X-ray fluorescence mapping of freshly excised roots show Hg sequestered on the root surface and outlining individual root cells, while Se is more evenly distributed throughout the root. There are also discrete Hg-only, Se-only regions and an overall strong correlation between Hg and Se throughout the root. Analysis of the X-ray absorption near edge structure (XANES) spectra show a 'background' of methylselenocysteine within the root with discrete spots of SeO{sub 3}{sup 2-}, Se{sup 0} and solid HgSe on the root surface. Mercury outlining individual root cells is possibly binding to sulfhydryl groups or plasma membrane or cell wall proteins, and in some places reacting with reduced selenium in the rhizosphere to form a mercury(II) selenide species. Together with the formation of the root-bound mercury(II) selenide species, we also report on the formation of cinnabar (HgS) and Hg{sup 0} in the rhizosphere. The results presented herein shed light on the intricate chemical and biological processes occurring within the rhizosphere that influence Hg and Se bioavailability and will be instrumental in predicting the fate and assisting in the remediation of these metals in the environment and informing whether or not fruit and vegetable food selection from aerial plant compartments or roots from plants grown in Hg contaminated soils, are safe for consumption.

  11. Selenium Speciation in Arabidopsis Thaliana

    OpenAIRE

    Wang, Xiaoou

    2011-01-01

    Selenium has been proved as an essential micronutrient and is beneficial to animals and humans. It is a structural component of the important antioxidant enzyme, glutathione peroxidase, which catalyzes reactions to detoxify reactive oxygen species. However, the essentiality of Se in plants remains controversial and the protective role of Se in plants has rarely been investigated. In this study, Arabidopsis thaliana was grown in controlled environments having selenate or selenite enriched medi...

  12. Selenium determination by fluorimetric method

    International Nuclear Information System (INIS)

    A fluorimetric method to determine selenium both in vegetable samples and blood serum is developed. The method consists of a radioisotope 75Se initially in order to optimize the determination of analytical conditions. Three samples digestion processes and also some factors related to methodology is studied. The nitric-percloric digestion process for 40 samples and the analytical process is shown. (M.J.C.)

  13. Bioavailability: implications for science/cleanup policy

    Energy Technology Data Exchange (ETDEWEB)

    Denit, Jeffery; Planicka, J. Gregory

    1998-12-01

    This paper examines the role of bioavailability in risk assessment and cleanup decisions. Bioavailability refers to how chemicals ''behave'' and their ''availability'' to interact with living organisms. Bioavailability has significant implications for exposure risks, cleanup goals, and site costs. Risk to human health and the environment is directly tied to the bioavailability of the chemicals of concern.

  14. Learning selenium testing tools with Python

    CERN Document Server

    Gundecha, Unmesh

    2014-01-01

    If you are a quality testing professional, or a software or web application developer looking to create automation test scripts for your web applications, with an interest in Python, then this is the perfect guide for you. Python developers who need to do Selenium testing need not learn Java, as they can directly use Selenium for testing with this book.

  15. Advanced prostate cancer risk in relation to toenail selenium levels

    NARCIS (Netherlands)

    Geybels, M.S.; Verhage, B.A.J.; Schooten, F.J. van; Goldbohm, A.; Brandt, P.A. van den

    2013-01-01

    BACKGROUND: Selenium may prevent advanced prostate cancer (PCa), but most studies on this topic were conducted in populations with moderate to high selenium status. We investigated the association of toenail selenium, reflecting long-term selenium exposure, and advanced PCa risk in a population from

  16. Determination of selenium species in environmental samples

    International Nuclear Information System (INIS)

    The essential nature of selenium as well as its toxicity depend on the concentration and the chemical forms in which this element is present in a given sample. Dissolved inorganic selenium can be found in natural water and soil as selenides, selenite and selenate. Organoselenium compounds present in air, soil and plants are volatile methylselenides, trimethylselenonium ion and several selenoamino acids. This review is a summary of recent research on the determination of selenium species in environmental samples such as water, air, soil and plants. Stability of selenium species in solutions and their storage is also discussed. In the metabolic pathway in the body selenide could act as the common intermediate for inorganic and organic Se sources as well as the checkpoint between further utilization and excretion of selenium. (author)

  17. Bioavailability of the polyphenols: status and controversies.

    Science.gov (United States)

    D'Archivio, Massimo; Filesi, Carmelina; Varì, Rosaria; Scazzocchio, Beatrice; Masella, Roberta

    2010-01-01

    The current interest in polyphenols has been driven primarily by epidemiological studies. However, to establish conclusive evidence for the effectiveness of dietary polyphenols in disease prevention, it is useful to better define the bioavailability of the polyphenols, so that their biological activity can be evaluated. The bioavailability appears to differ greatly among the various phenolic compounds, and the most abundant ones in our diet are not necessarily those that have the best bioavailability profile. In the present review, we focus on the factors influencing the bioavailability of the polyphenols. Moreover, a critical overview on the difficulties and the controversies of the studies on the bioavailability is discussed. PMID:20480022

  18. Bioavailability of the Polyphenols: Status and Controversies

    Directory of Open Access Journals (Sweden)

    Massimo D’Archivio

    2010-03-01

    Full Text Available The current interest in polyphenols has been driven primarily by epidemiological studies. However, to establish conclusive evidence for the effectiveness of dietary polyphenols in disease prevention, it is useful to better define the bioavailability of the polyphenols, so that their biological activity can be evaluated. The bioavailability appears to differ greatly among the various phenolic compounds, and the most abundant ones in our diet are not necessarily those that have the best bioavailability profile. In the present review, we focus on the factors influencing the bioavailability of the polyphenols. Moreover, a critical overview on the difficulties and the controversies of the studies on the bioavailability is discussed.

  19. Blood selenium levels and contribution of food groups to selenium intake in adolescent girls in Iceland

    Directory of Open Access Journals (Sweden)

    Ingibjorg Gunnarsdottir

    2012-08-01

    Full Text Available Background/objectives: Significant changes have been reported in dietary habits and food availability in Iceland that would be expected to compromise selenium intake and status, especially among young people. These include substantial decreases in the consumption of fish and milk, as well as the selenium content of imported wheat. The aim of this study was to assess selenium in the diet and whole blood of adolescent girls, as well as define the most important foods contributing to intake and blood concentrations of selenium. Design: The subjects were 96 randomly selected girls, aged 16–20, who answered a validated food frequency questionnaire (FFQ for dietary assessment. Selenium intake from each food group was calculated in µg/day. Blood samples were collected for measurement of whole blood selenium. Results: Mean dietary selenium was 51±25 µg/day. Milk/dairy products, including cheese, contributed 36±14% of total dietary selenium; fish 18±12%; and bread/cereal products 13±6%. Mean whole blood selenium was 117±12 µg/l (range 90–208; nearly 90% of subjects were above the optimal level of 100 µg/l. Fish and bread/cereal products were the only foods significantly correlated with selenium in blood (r=0.32; P = 0.002 and r=0.22; P = 0.04, respectively while no correlation was found with milk and dairy products in spite of their greater contribution to total selenium intake. Conclusion: In this population of Icelandic adolescent girls, selenium intake and status seem acceptable. Judging from associations between intake and blood levels, fish and cereals may be the most important contributors to blood selenium.

  20. Total mercury, organic mercury and selenium in liver and kidney of a South American coastal dolphin

    Energy Technology Data Exchange (ETDEWEB)

    Seixas, Tercia G. [Departamento de Quimica, PUC-Rio, 22453-900 Rio de Janeiro, RJ (Brazil); Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil)], E-mail: tercia@rdc.puc-rio.br; Kehrig, Helena do A. [Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil); Costa, Monica [Departamento de Oceanografia, CTG-UFPE, 50740-550 Recife, PE (Brazil); Fillmann, Gilberto [Departamento de Oceanografia, FURG, C.P. 474, 96201-900 Rio Grande, RS (Brazil); Di Beneditto, Ana Paula M. [Laboratorio de Ciencias Ambientais, CBB-UENF, 28013-602 Campos dos Goytacazes, RJ (Brazil); Secchi, Eduardo R. [Departamento de Oceanografia, FURG, C.P. 474, 96201-900 Rio Grande, RS (Brazil); Laboratorio de Tartarugas e Mamiferos Marinhos, Departamento de Oceanografia e Museu Oceanografico ' Prof. E.C. Rios' , FURG, 96201-900 Rio Grande, RS (Brazil); Souza, Cristina M.M. [Laboratorio de Ciencias Ambientais, CBB-UENF, 28013-602 Campos dos Goytacazes, RJ (Brazil); Malm, Olaf [Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil); Moreira, Isabel [Departamento de Quimica, PUC-Rio, 22453-900 Rio de Janeiro, RJ (Brazil)

    2008-07-15

    Selenium and total and organic mercury were determined in the liver and kidney of franciscana dolphin (Pontoporia blainvillei) incidentally caught in fishing nets along two Brazilian coastal areas (southeast and south). Regional differences in the concentrations of these contaminants were observed in P. blainvillei. Liver showed the highest organic and total mercury. In general, samples of individuals collected at the southern of Brazil had the highest concentrations of selenium and total and organic mercury. No significant gender differences were observed. Growth stage influenced the accumulation of these contaminants in both organs, and hepatic concentrations increased with the body length, according to the sampling area. Molar mercury and selenium concentrations in liver were significantly correlated, with a Se:Hg ratio close to 4. The among-site differences we found may be related to differences in preferred prey, bioavailability in the marine environment, environmental conditions, or these individuals may belong to distinct populations. - This study presents some useful data on the bioaccumulation of Hg, organic Hg and Se, and their inter-element relationships in a Brazilian small cetacean.

  1. Total mercury, organic mercury and selenium in liver and kidney of a South American coastal dolphin

    International Nuclear Information System (INIS)

    Selenium and total and organic mercury were determined in the liver and kidney of franciscana dolphin (Pontoporia blainvillei) incidentally caught in fishing nets along two Brazilian coastal areas (southeast and south). Regional differences in the concentrations of these contaminants were observed in P. blainvillei. Liver showed the highest organic and total mercury. In general, samples of individuals collected at the southern of Brazil had the highest concentrations of selenium and total and organic mercury. No significant gender differences were observed. Growth stage influenced the accumulation of these contaminants in both organs, and hepatic concentrations increased with the body length, according to the sampling area. Molar mercury and selenium concentrations in liver were significantly correlated, with a Se:Hg ratio close to 4. The among-site differences we found may be related to differences in preferred prey, bioavailability in the marine environment, environmental conditions, or these individuals may belong to distinct populations. - This study presents some useful data on the bioaccumulation of Hg, organic Hg and Se, and their inter-element relationships in a Brazilian small cetacean

  2. Influence the oxidant action of selenium in radiosensitivity induction and cell death in yeast Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Ionizing radiations are from both natural sources such as from anthropogenic sources. Recently, radiotherapy has emerged as one of the most common therapies against cancer. Co-60 irradiators (cobalt-60 linear accelerators) are used to treat of malignant tumors routinely in hospitals around the world. Exposure to ionizing radiation can induce changes in cellular macromolecules and affect its functions, because they cause radiolysis of the water molecule generating reactive oxygen species, which can cause damage to virtually all organelles and cell components known as oxidative damage that can culminate in oxidative stress. Oxidative stress is a situation in which the balance between oxidants and antioxidants is broken resulting in excessive production of reactive species, it is not accompanied by the increase in antioxidant capacity, making it impossible to neutralize them. Selenium is a micronutrient considered as antioxidant, antiinflammatory, which could prevent cancer. Selenium in biological system exists as seleno proteins. Nowadays, 25 human seleno proteins have been identified, including glutathione peroxidase, an antioxidant enzyme. Yeasts have the ability to incorporate various metals such as iron, cadmium, zinc and selenium, as well as all biological organisms. The yeast Saccharomyces cerevisiae, unlike mammalian cells is devoid of seleno proteins, being considered as a practical model for studies on the toxicity of selenium, without any interference from the metabolism of seleno proteins. Moreover, yeast cells proliferate through the fermentation, the microbial equivalent of aerobic glycolysis in mammals and the process is also used by tumors. Several reports show that the pro-oxidante effects and induced toxic selenium compounds occur at lower doses and in malignant cells compared with benign cells. Therefore selenium giving a great therapeutic potential in cancer treatment .Our objective was to determine whether selenium is capable to sensitize yeasts

  3. Sources and cycling of selenium in the western and equatorial Atlantic Ocean

    Science.gov (United States)

    Cutter, Gregory A.; Cutter, Lynda S.

    The concentration and chemical speciation of selenium were determined at six vertical profile stations along a 11,000-km-long horizontal transect from 34°S to 8°N in the western Atlantic. The depth profiles of total dissolved selenium, selenite (SeIV), and selenate (VI) all showed surface-water depletion and deep-water enrichment characteristic of the nutrient-like behavior of selenium that has been observed in other ocean basins. In North Atlantic Deep Water, the Se(IV)/Se(VI) ratios were generally similar to those found in the eastern Atlantic and North Pacific (0.7), but waters originating in the higher latitudes of the southern hemisphere, Antarctic Intermediate (AAIW) and Bottom Water, and Upper Circumpolar Deep Water (UCDW), were enriched in selenate and had correspondingly low Se(IV)/Se(VI) ratios (ca. 0.4). In contrast to these inorganic selenium species, organic selenide had maxima in the surface waters of the oligotrophic stations and undetectable concentrations in the mid- and deep waters. One exception to this pattern was found at the southernmost station (33°S) where a secondary organic selenide maximum was found in the AAIW and UCDW (700-1900 m). This observation can be explained by considering the 10-year residence time of organic selenide in the water column and the relatively young age (aluminum levels due to the input of North African dust. While selenium is not enriched in mineral aerosols themselves, air masses from Europe can be entrained in those leaving North Africa, enriching selenium as a consequence. The estimate of atmospheric deposition of selenium to the equatorial Atlantic is ca. 10×10 6 mol yr -1, while relatively low selenium concentrations in the Amazon River (0.48 nM) only deliver ca. 2×10 6 mol yr -1. Atmospheric selenium inputs dominate fluxes to the equatorial Atlantic, but these and Amazonian inputs profoundly affect the distribution and speciation of selenium in this region.

  4. Selenium in Oncology: From Chemistry to Clinics

    Directory of Open Access Journals (Sweden)

    Oliver Micke

    2009-10-01

    Full Text Available The essential trace element selenium, which is a crucial cofactor in the most important endogenous antioxidative systems of the human body, is attracting more and more the attention of both laypersons and expert groups. The interest of oncologists mainly focuses in the following clinical aspects: radioprotection of normal tissues, radiosensitizing in malignant tumors, antiedematous effect, prognostic impact of selenium, and effects in primary and secondary cancer prevention. Selenium is a constituent of the small group of selenocysteine-containing selenoproteins and elicits important structural and enzymatic functions. Selenium deficiency has been linked to increased infection risk and adverse mood states. It has been shown to possess cancer-preventive and cytoprotective activities in both animal models and humans. It is well established that Se has a key role in redox regulation and antioxidant function, and hence in membrane integrity, energy metabolism and protection against DNA damage. Recent clinical trials have shown the importance of selenium in clinical oncology. Our own clinical study involving 48 patients suggest that selenium has a positive effect on radiation-associated secondary lymphedema in patients with limb edemas, as well as in the head and neck region, including endolaryngeal edema. Another randomized phase III study of our group was performed to examine the cytoprotective properties of selenium in radiation oncology. The aim was to evaluate whether sodium selenite is able to compensate a preexisting selenium deficiency and to prevent radiation induced diarrhea in adjuvant radiotherapy for pelvic gynecologic malignancies. Through this study, the significant benefits of sodium selenite supplementation with regards to selenium deficiency and radiotherapy induced diarrhea in patients with cervical and uterine cancer has been shown for the first time in a prospective randomized trial. Survival data imply that supplementation with

  5. Selenium in oncology: from chemistry to clinics.

    Science.gov (United States)

    Micke, Oliver; Schomburg, Lutz; Buentzel, Jens; Kisters, Klaus; Muecke, Ralph

    2009-01-01

    The essential trace element selenium, which is a crucial cofactor in the most important endogenous antioxidative systems of the human body, is attracting more and more the attention of both laypersons and expert groups. The interest of oncologists mainly focuses in the following clinical aspects: radioprotection of normal tissues, radiosensitizing in malignant tumors, antiedematous effect, prognostic impact of selenium, and effects in primary and secondary cancer prevention. Selenium is a constituent of the small group of selenocysteine-containing selenoproteins and elicits important structural and enzymatic functions. Selenium deficiency has been linked to increased infection risk and adverse mood states. It has been shown to possess cancer-preventive and cytoprotective activities in both animal models and humans. It is well established that Se has a key role in redox regulation and antioxidant function, and hence in membrane integrity, energy metabolism and protection against DNA damage. Recent clinical trials have shown the importance of selenium in clinical oncology. Our own clinical study involving 48 patients suggest that selenium has a positive effect on radiation-associated secondary lymphedema in patients with limb edemas, as well as in the head and neck region, including endolaryngeal edema. Another randomized phase III study of our group was performed to examine the cytoprotective properties of selenium in radiation oncology. The aim was to evaluate whether sodium selenite is able to compensate a preexisting selenium deficiency and to prevent radiation induced diarrhea in adjuvant radiotherapy for pelvic gynecologic malignancies. Through this study, the significant benefits of sodium selenite supplementation with regards to selenium deficiency and radiotherapy induced diarrhea in patients with cervical and uterine cancer has been shown for the first time in a prospective randomized trial. Survival data imply that supplementation with selenium does not

  6. Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California.

    Science.gov (United States)

    Saiki, Michael K; Martin, Barbara A; May, Thomas W

    2012-09-01

    Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98-58.0 μg Se/g; midge larvae, 12.7-50.6 μg Se/g; mosquitofish, 13.2-20.2 μg Se/g; and mollies, 12.8-30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish. PMID:21915593

  7. Revised reference values for selenium intake.

    Science.gov (United States)

    Kipp, A P; Strohm, D; Brigelius-Flohé, R; Schomburg, L; Bechthold, A; Leschik-Bonnet, E; Heseker, H

    2015-10-01

    The German, Austrian and Swiss nutrition societies are the joint editors of the 'reference values for nutrient intake'. They have revised the reference values for the intake of selenium and published them in February 2015. The saturation of selenoprotein P (SePP) in plasma is used as a criterion for the derivation of reference values for selenium intake in adults. For persons from selenium-deficient regions (China) SePP saturation was achieved with a daily intake of 49μg of selenium. When using the reference body weights the D-A-CH reference values are based upon, the resulting estimated value for selenium intake is 70μg/day for men and 60μg/day for women. The estimated value for selenium intake for children and adolescents is extrapolated using the estimated value for adults in relation to body weight. For infants aged 0 to under 4 months the estimated value of 10μg/day was derived from the basis of selenium intake via breast milk. For infants aged 4 to under 12 months this estimated value was used and taking into account the differences regarding body weight an estimated value of 15μg/day was derived. For lactating women compared to non-lactating women a higher reference value of 75μg/day is indicated due to the release of selenium with breast milk. The additional selenium requirement for pregnant women is negligible, so that no increased reference value is indicated. PMID:26302929

  8. Selenium and Prostate Cancer Prevention: Insights from the Selenium and Vitamin E Cancer Prevention Trial (SELECT)

    OpenAIRE

    Nicastro, Holly L.; Dunn, Barbara K

    2013-01-01

    The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was conducted to assess the efficacy of selenium and vitamin E alone, and in combination, on the incidence of prostate cancer. This randomized, double-blind, placebo-controlled, 2 × 2 factorial design clinical trial found that neither selenium nor vitamin E reduced the incidence of prostate cancer after seven years and that vitamin E was associated with a 17% increased risk of prostate cancer compared to placebo. The null result was ...

  9. Nuclear transformations studies in selenium isotopes

    International Nuclear Information System (INIS)

    A compilation is made with regard to the chemical effects produced by nuclear transformations, such as the chemical effects of the beta decay and the chemical effects of the reaction (n,γ) in selenium radioisotopes. As a particular case the chemical effect of the isomeric transition of sup(81m)Se(VI) in potassium selenate crystals marked with radioactive selenium is studied experimentally and the method of adsorption in activated carbon is applied for the analytical separation of the traces of the nuclear isomer tetravalent sup(81b)Se(IV) of one fraction which contains the mixture of the selenium radioisotopes. (author)

  10. Incorporation of selenium(IV) and selenium(VI) on uranyl peroxide

    International Nuclear Information System (INIS)

    The sorption of Se(IV) and Se(VI) on uranium peroxide has been studied considering the sorption kinetics, the sorption isotherms and the effect of pH. Selenium sorption on studtite is fitted with a pseudosecond order reaction model; in addition, two different mechanisms seem to influence the sorption process: micropore diffusion and intra-particle diffusion. Both selenium(IV) and selenium(VI) are sorbed on studtite through a monolayer coverage. Sorption is higher at acidic pH than at alkaline pH. This behaviour is consistent with the chemical speciation of selenium in solution and with the acid-base properties of the solid. (author)

  11. Encapsulation of selenium in chitosan nanoparticles improves selenium availability and protects cells from selenium-induced DNA damage response

    Science.gov (United States)

    Selenium, an essential mineral, plays important roles in optimizing human health. Chitosan is an effective, naturally oriented material for synthesizing nanoparticles with polyanions and exhibit preferable properties such as biocompatibility, biodegradation and resistance to certain enzymes. We have...

  12. Feasibility study on simultaneous removal of sulfur and trace selenium in the MTD-FGD reactor

    Energy Technology Data Exchange (ETDEWEB)

    Li Yuzhong; Tong Huiling; Zhuo Yuqun; Li Yan; Chen Changhe; Xu Xuchang [Tsinghua University, Beijing (China). Department of Thermal Engineering

    2007-07-15

    This study deals with the simultaneous removal of sulfur dioxide (SO{sub 2}) and trace selenium dioxide (SeO{sub 2}) from flue gas by calcium oxide (CaO) adsorption in the moderate temperature range, especially the feasibility of simultaneous removal of these two pollutants in a moderate temperature dry flue gas desulfurization (MTD-FGD) reactor. The effect of SO{sub 2} presence on selenium capture is studied through the experiments performed on a thermogravimetric analyzer (TGA) and the following conclusions can be obtained. When CaO conversion is relatively low and the reaction rate is controlled by chemical reaction kinetics, the SO{sub 2} presence does not affect selenium capture. When CaO conversion is very high and the reaction rate is controlled by product layer diffusion, the SO{sub 2} presence and the product layer diffusion resistance jointly reduce selenium capture. Through analyses of some pilot scale MTD-FGD tests, it can be concluded that in the MTD-FGD reactor, the sulfate reaction of sorbent particles is generally kinetically controlled. Therefore, it is feasible that sulfur and trace selenium can be simultaneously removed by Ca-based sorbent in the MTD-FGD reactor.

  13. Feasibility study on simultaneous removal of sulfur and trace selenium in the MTD-FGD reactor

    Institute of Scientific and Technical Information of China (English)

    LI Yuzhong; TONG Huiling; ZHUO Yuqun; LI Yan; CHEN Changhe; XU Xuchang

    2007-01-01

    This study deals with the simultaneous removal of sulfur dioxide (SO2) and trace selenium dioxide (SeO2)from flue gas by calcium oxide (CaO) adsorption in the moderate temperature range,especially the feasibility of simultaneous removal of these two pollutants in a moderate temperature dry flue gas desulfurization (MTD-FGD) reactor.The effect of SO2 presence on selenium capture is studied through the experiments performed on a thermogravimetric analyzer (TGA) and the following conclusions can be obtained.When CaO conversion is relatively low and the reaction rate is controlled by chemical reaction kinetics,the SO2 presence does not affect selenium capture.When CaO conversion is very high and the reaction rate is controlled by product layer diffusion,the SO2 presence and the product layer diffusion resistance jointly reduce selenium capture.Through analyses of some pilot scale MTD-FGD tests,it can be concluded that in the MTD-FGD reactor,the sulfate reaction of sorbent particles is generally kinetically controlled.Therefore,it is feasible that sulfur and trace selenium can be simultaneously removed by Ca-based sorbent in the MTD-FGD reactor.

  14. Selenium status is positively associated with bone mineral density in healthy aging European men

    NARCIS (Netherlands)

    C.M. Beukhof (Carolien); M. Medici (Marco); A.W. van den Beld (Annewieke); Birgit Hollenbach (B.); A. Hoeg (Antonia); W. Visser (Willy); W.W. de Herder (Wouter); T.J. Visser (Theo); L. Schomburg (Lutz); R.P. Peeters (Robin)

    2016-01-01

    textabstractObjective It is still a matter of debate if subtle changes in selenium (Se) status affect thyroid function tests (TFTs) and bone mineral density (BMD). This is particularly relevant for the elderly, whose nutritional status is more vulnerable. Design and Methods We investigated Se status

  15. Influence of relative trophic position and carbon source on selenium bioaccumulation in turtles from a coal fly-ash spill site

    International Nuclear Information System (INIS)

    Selenium (Se) is a bioaccumulative constituent of coal fly-ash that can disrupt reproduction of oviparous wildlife. In food webs, the greatest enrichment of Se occurs at the lowest trophic levels, making it readily bioavailable to higher consumers. However, subsequent enrichment at higher trophic levels is less pronounced, leading to mixed tendencies for Se to biomagnify. We used stable isotopes (15N and 13C) in claws to infer relative trophic positions and relative carbon sources, respectively, of seven turtle species near the site of a recently-remediated coal fly-ash spill. We then tested whether Se concentrations differed with relative trophic position or relative carbon source. We did not observe a strong relationship between δ15N and Se concentration. Instead, selenium concentrations decreased with increasing δ13C among species. Therefore, in an assemblage of closely-related aquatic vertebrates, relative carbon source was a better predictor of Se bioaccumulation than was relative trophic position. -- Highlights: •Stable isotope results showed trophic separation among turtle species. •Selenium concentrations did not biomagnify with relative trophic position. •Selenium concentrations decreased with increasing δ13C among species. •Carbon source influenced Se bioaccumulation in an assemblage of related vertebrates. -- Stable isotope differences indicate that claw selenium concentrations differ among relative carbon sources, and not among relative trophic positions, in an assemblage of aquatic turtles

  16. Oral iron and the bioavailability of zinc.

    OpenAIRE

    Meadows, N J; Grainger, S L; Ruse, W; Keeling, P W; Thompson, R. P.

    1983-01-01

    The oral bioavailability of zinc was studied in nonpregnant adults before and 24 hours after two weeks of oral supplementation with iron and folic acid. Bioavailability was greatly reduced, and the shape of the plasma curves suggested that this was due to impairment of the intestinal absorption of zinc. The findings suggest that the reduced bioavailability of zinc occurs because of interelement competition in the bowel wall. This might induce zinc depletion.

  17. Effect of Bioenhancers on Amoxicillin bioavailability

    OpenAIRE

    Barve, Kalyani; Ruparel, Kushal

    2015-01-01

    Amoxicillin, which inspite of being effective is losing its importance due to less bioavailability. Bioavailability could be enhanced by combining the antibiotics with bioenhancers like Piperine and Ginger resin. The present abstract deals with the use of piperine and ginger resin in increasing the bioavailability of amoxicillin using the insitu SPIP method. Piperine, isolated was found to be 99 % pure and ginger resin contained 4.36 % w/w of gingerol. The absorption of amoxicillin increased ...

  18. Bioavailability of flavonoids and cinnamic acids and their effect on plasma homocysteine in humans

    OpenAIRE

    Olthof, M.R.

    2001-01-01

    Dietary antioxidants might prevent oxidative damage to tissues and therefore protect against cardiovascular disease and cancer. Dietary phenols are strong antioxidants in vitro but their role in vivo is uncertain. Furthermore, there are only limited data on their bioavailability in humans. The aim of this thesis was to investigate whether bioavailability data on flavonoids and cinnamic acids support the hypothesis that they can affect health in humans . Because the group of phenols in foods i...

  19. Selenium: environmental significance, pollution, and biological treatment technologies.

    Science.gov (United States)

    Tan, Lea Chua; Nancharaiah, Yarlagadda V; van Hullebusch, Eric D; Lens, Piet N L

    2016-01-01

    Selenium is an essential trace element needed for all living organisms. Despite its essentiality, selenium is a potential toxic element to natural ecosystems due to its bioaccumulation potential. Though selenium is found naturally in the earth's crust, especially in carbonate rocks and volcanic and sedimentary soils, about 40% of the selenium emissions to atmospheric and aquatic environments are caused by various industrial activities such as mining-related operations. In recent years, advances in water quality and pollution monitoring have shown that selenium is a contaminant of potential environmental concern. This has practical implications on industry to achieve the stringent selenium regulatory discharge limit of 5μgSeL(-1) for selenium containing wastewaters set by the United States Environmental Protection Agency. Over the last few decades, various technologies have been developed for the treatment of selenium-containing wastewaters. Biological selenium reduction has emerged as the leading technology for removing selenium from wastewaters since it offers a cheaper alternative compared to physico-chemical treatments and is suitable for treating dilute and variable selenium-laden wastewaters. Moreover, biological treatment has the advantage of forming elemental selenium nanospheres which exhibit unique optical and spectral properties for various industrial applications, i.e. medical, electrical, and manufacturing processes. However, despite the advances in biotechnology employing selenium reduction, there are still several challenges, particularly in achieving stringent discharge limits, the long-term stability of biogenic selenium and predicting the fate of bioreduced selenium in the environment. This review highlights the significance of selenium in the environment, health, and industry and biotechnological advances made in the treatment of selenium contaminated wastewaters. The challenges and future perspectives are overviewed considering recent

  20. Selenium status of idiopathic infertile Nigerian males.

    Science.gov (United States)

    Akinloye, Oluyemi; Arowojolu, A O; Shittu, O B; Adejuwon, C A; Osotimehin, Babatunde

    2005-04-01

    Selenium concentration in the sera and seminal plasma of 60 infertile males (40 oligospermia and 20 azoospermia) and 40 males with proven evidence of fertility (normospermia; control group) were estimated using atomic absorption spectrophotometry. Results were correlated with spermatogram and hormonal levels in order to determine their relationship and significance in male infertility. The mean serum concentrations of selenium was found to be significantly increased in oligospermic compared to azoospermic subjects and controls (p physiological balance in the distribution of selenium in serum and seminal plasma compartment of control males. A disturbance in this balance has a significant influence on spermatogenesis. Selenium appears to have a positive influence on Leydig cells, thus influencing the secretion of testosterone. PMID:15851828

  1. Selenium supplementation induces mitochondrial biogenesis in trophoblasts

    Czech Academy of Sciences Publication Activity Database

    Khera, A.; Dong, L. F.; Holland, O.; Vanderlelie, J.; Pasdar, E.A.; Neužil, Jiří; Perkins, A.V.

    2015-01-01

    Roč. 36, č. 8 (2015), s. 363-369. ISSN 0143-4004 Institutional support: RVO:86652036 Keywords : Selenium * Reactive oxygen species * Mitochondrial biogenesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.710, year: 2014

  2. Reproductive impacts of elevated selenium levels

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objectives of this study were to: 1. Evaluate selenium levels in Neotropical migrants and riparian obligate birds on Imperial National Wildlife Refuge. 2....

  3. Biofortification and phytoremediation of selenium in China

    Science.gov (United States)

    Biofortification is an agricultural process that increases the uptake and accumulation of specific nutrients, e.g. selenium (Se), in agricultural food products through plant breeding, genetic engineering, and manipulation of agronomic practices. The development and uses of biofortified agricultural ...

  4. Selenium supplementation for patients with Graves’ hyperthyroidism (the GRASS trial)

    DEFF Research Database (Denmark)

    Watt, Torquil; Cramon, Per; Bjorner, Jakob Bue;

    2013-01-01

    Graves' hyperthyroidism is an autoimmune disease causing hyperfunction of the thyroid gland. The concentration of selenium is high in the thyroid gland and two important groups of enzymes within the thyroid are selenoproteins, that is, they depend on selenium. Selenium may have beneficial effects...... on autoimmune hypothyroidism and on Graves' orbitopathy, but the effects of selenium on Graves' hyperthyroidism is unknown.We hypothesize that adjuvant selenium may be beneficial in the treatment of Graves' hyperthyroidism. The objective is to investigate if selenium supplementation plus standard...

  5. Selenium and functional constipation in children

    OpenAIRE

    Marlina Tanjung; Supriatmo Supriatmo; Melda Deliana; Ade Rachmat Yudiyanto; Atan Baas Sinuhaji

    2016-01-01

    Background Constipation is a common problem in children, with approximately 90 to 95% of constipation cases having functional constipation. Oxidative stress may be a causative factor in gastrointestinal diseases, alleved by intervention with antioxidants. Selenium is an essential trace element and acts as a cofactor of gluthathione peroxidase, which protects membranes from oxidative damage.Objective To determine the effect of selenium on functional constipation in children.Methods We conducte...

  6. Mercury-selenium interactions in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Saroff, L. [Department of Energy, Washington, DC (United States); Lipfert, W.; Moskowitz, P.D. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science

    1996-02-01

    The Clean Air Act Amendments of 1990 require the U.S. Environmental Protection Agency (EPA) to consider the need to control emissions of trace elements and compounds emitted from coal combustion, including coal-fired power plants. Concern has been expressed about emissions of mercury and arsenic, for example, since health effects may be associated with exposure to some of these compounds. By and large, effects of trace element emissions have been considered individually, without regard for possible interactions. To the extent that the relevant environmental pathways and health endpoints differ, this mode of analysis is appropriate. For example, arsenic is considered a carcinogen and mercury affects the brain. However, there may be compelling reasons to consider emissions of mercury (Hg) and selenium (Se) together: (1) Both Se and Hg are emitted from power plants primarily as vapors. (2) Hg and Se are both found in fish, which is the primary pathway for Hg health effects. (3) Se has been shown to suppress Hg methylation in aqueous systems, which is a necessary step for Hg health effects at current environmental concentrations. (4) Se is a trace element that is essential for health but that can also be toxic at high concentrations; it can thus have both beneficial and adverse health effects, depending on the dosage. This paper reviews some of the salient characteristics and interactions of the Hg-Se system, to consider the hypothesis that the effects of emissions of these compounds should be considered jointly.

  7. Selenium in Gluten-free Products.

    Science.gov (United States)

    Rybicka, Iga; Krawczyk, Magdalena; Stanisz, Ewa; Gliszczyńska-Świgło, Anna

    2015-06-01

    The nutritional value of gluten-free products is the subject of interest for food technologists and nutritionists, as the only effective treatment for celiac disease is a lifelong gluten-free diet. As selenium deficiencies in celiac disease are observed, the aim of the study was to determine the selenium content in 27 grain gluten-free products available on the European Union (EU) market. Moreover, selenium content in products based on popular gluten-free cereals like corn, rice, and buckwheat and in relatively new or less popular products based on oat, amaranth, teff, and quinoa was compared. Selenium content in the tested products ranged from 0.9 to 24.5 μg/100 g. The average content of selenium in products based on popular gluten-free cereals was 2.8 μg/100 g and in products based on oat, amaranth, teff, and quinoa was 10.8 μg/100 g. It indicates that products based on less popular grains, especially on oat, should be more frequently chosen as a source of selenium by people on gluten-free diet than traditionally consumed gluten-free grains. PMID:25690718

  8. Soil and plant selenium at a reclaimed uranium mine.

    Science.gov (United States)

    Sharmasarkar, Shankar; Vance, George F

    2002-01-01

    Selenium (Se) associated with reclaimed uranium (U) mine lands may result in increased food chain transfer and water contamination. To assess post-reclamation bioavailability of Se at a U mine site in southeastern Wyoming, we studied soil Se distribution, dissolution, speciation, and sorption characteristics and plant Se accumulation. Phosphate-extractable soil Se exceeded the critical limit of 0.5 mg/kg in all the samples, whereas total soil Se ranged from a low (0.6 mg/kg) to an extremely high (26 mg/kg) value. Selenite was the dominant species in phosphate and ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA) extracts, whereas selenate was the major Se species in hot water extracts. Extractable soil Se concentrations were in the order of KH2PO4 > AB-DTPA > hot water > saturated paste. The soils were undersaturated with respect to various Se solid phases, albeit with high levels of extractable Se surpassing the critical limit. Calcium and Mg minerals were the potential primary solids controlling Se dissolution, with dissolved organic carbon in the equilibrium solutions resulting in enhanced Se availability. Adsorption was a significant (r2 = 0.76-0.99 at P phytoremediation, or the palatable forage species may be used as animal feed supplements in Se-deficient areas. PMID:12371169

  9. ENHANCEMENT OF BIOAVAILABILITY THROUGH INCREASE IN DRUG PERMEATION, STABILITY AND RETENTION TIME

    Directory of Open Access Journals (Sweden)

    Vishal Sachdeva

    2013-06-01

    Full Text Available The rate and extent to which an unchanged drug reaches the systemic circulation is called as bioavailability (BA. Bioavailability, a subcategory of absorption is one of the principal pharmacokinetic parameter determined for an active substance form a pharmaceutical product. It also indicates the fractional extent to which a dose of drug reaches its site of action or biological fluid from which the drug has access to its site of action. Physical properties of drug, drug formulation, route of administration, gastric emptying rate etc. are several factors affect the bioavailability of drug from its drug product. Poor solubility, enzymatic and transporters barrier, drug stability and short retention of the drug in stomach due to peristaltic movement are several factors decrease the bioavailability of the drug. This review deals with the bioavailability improvements techniques from poor permeation, lesser stability and short retention of the drug in stomach. Lipid based formulations; ion pairing and use of permeation enhancer are different methods to enhance the bioavailability through increase in permeation. Enteric coating, complexation and metabolism inhibitors lead to increase in drug stability. Bioadhesive polymers in formulation improve the gastro retention time serve as improved bioavailable product.

  10. Determination of the content of selenium in selenium yeast by NAA

    International Nuclear Information System (INIS)

    The auther succeeded in cultivating brewers yeast, saccharomyces cerevisia, containing various concentrations of sodium selenite in glucose-glycine-yeast (GGY) extract medium. The content of selenium in selenium yeast was determined by NAA. The results indicate that this method is accurate and needs less time than other methods

  11. Updates on clinical studies of selenium supplementation in radiotherapy

    International Nuclear Information System (INIS)

    To establish guidelines for the selenium supplementation in radiotherapy we assessed the benefits and risks of selenium supplementation in radiotherapy. Clinical studies on the use of selenium in radiotherapy were searched in the PubMed electronic database in January 2013. Sixteen clinical studies were identified among the 167 articles selected in the initial search. Ten articles were observational studies, and the other 6 articles reported studies on the effects of selenium supplementation in patients with cancer who underwent radiotherapy. The studies were conducted worldwide including European, American and Asian countries between 1987 and 2012. Plasma, serum or whole blood selenium levels were common parameters used to assess the effects of radiotherapy and the selenium supplementation status. Selenium supplementation improved the general conditions of the patients, improved their quality of life and reduced the side effects of radiotherapy. At the dose of selenium used in these studies (200–500 μg/day), selenium supplementation did not reduce the effectiveness of radiotherapy, and no toxicities were reported. Selenium supplementation may offer specific benefits for several types of cancer patients who undergo radiotherapy. Because high-dose selenium and long-term supplementation may be unsafe due to selenium toxicity, more evidence-based information and additional research are needed to ensure the therapeutic benefits of selenium supplementation

  12. Antimony bioavailability in mine soils

    International Nuclear Information System (INIS)

    Antimony has low bioavailability in mining and smelting contaminated soils and bacterial biosensors are not suitable for its detection. - Five British former mining and smelting sites were investigated and found to have levels of total Sb of up to 700 mg kg-1, indicating high levels of contamination which could be potentially harmful. However, this level of Sb was found to be biologically unavailable over a wide range of pH values, indicating that Sb is relatively unreactive and immobile in the surface layers of the soil, remaining where it is deposited rather than leaching into lower horizons and contaminating ground water. Sb, sparingly soluble in water, was unavailable to the bacterial biosensors tested. The bioluminescence responses were correlated to levels of co-contaminants such as arsenic and copper, rather than to Sb concentrations. This suggests that soil contamination by Sb due to mining and smelting operations is not a severe risk to the environment or human health provided that it is present as immobile species and contaminated sites are not used for purposes which increase the threat of exposure to identified receptors. Co-contaminants such as arsenic and copper are more bioavailable and may therefore be seen as a more significant risk

  13. Selenium

    Science.gov (United States)

    ... Dietary Guidelines for Americans . Foods contain vitamins , minerals , dietary fiber and other substances that benefit health. In some cases, fortified foods and dietary supplements may provide nutrients that otherwise may be ...

  14. Low selenium environment and Vitamin E in human serum relative to the Kaschin-Beck's disease

    Energy Technology Data Exchange (ETDEWEB)

    Hou, S.; Zhu, Z.

    1982-04-30

    In China, endemic regions of Kaschin-Beck's disease, Keshan disease, and animal white muscle disease basically overlap, mainly the transitional area between the moist Southeast and the arid Northwest. Tests conducted by the authors reveal that the selenium content of major soils of the regions affected by the diseases is 0.088 to 0.360 ppM, that of the grains below 20 to 30 ppB. Of the inhabitants, 94 percent have serum selenium content below 0.031 ..mu..g/l and the selenium content of the hair of inhabitants is 100 to 200 ppB. From July 1979 to June 1980, the authors treated 41 cases of Kaschin-Beck's disease with sodium selenite-V/sub E/ and 36 of them recovered from the disease. Based upon these data, the authors believe that environmental selenium deficiency of these regions is perhaps the cause of the low level selenium nutrition of the inhabitants. The low level selenium nutrition in turn leads to a reduction of certain enzymic activity to cause the Kaschin-Beck's disease, as well as the Keshan disease and the animal white muscle disease.

  15. New challenge in the speciation of selenium. Measurement and production on nano selenium

    International Nuclear Information System (INIS)

    Complete text of publication follows. We have found that several species of probiotic bacteria also used in food industry for making yogurts is capable of producing spherical elemental selenium nanospheres having an average diameter in the range of 50-500 nm when 1-1000 mg/L selenium was added to the medium in the form of selenite ions. Elemental selenium produced thereby has a high degree of purity, is spherical, and its size and crystalline form depends on the bacterium species applied. We have found that some species of the probiotic yogurt bacteria (e.g. Bifidobacterium bifidum or Bifidobacterium longum) are capable of producing the grey crystalline form of elemental selenium which is so far unprecedented in the art for any bacteria capable of producing elemental selenium nanoparticles. Our finding, therefore, enables the first time the development of economical industrial bacterial fermentation based processes for the production of a high quality elemental selenium material comprising uniformly sized grey or red nanospheres having an average diameter in the range of 50-500 nm. The size and the crystalline form of the produced nanosized (50-500 nm) spherical particles is defined by the selected microorganism. This genetic pre-determination result in reproducible production of a material having individual characteristics which can be used in numerous fields of industry and research. The produced nano selenium could be a good raw material for a production of certified reference materials. The measurement of the produced elemental nanoselenium is a new challenge for the speciation analysis. A sample preparation and measurement method was developed and investigated for the analysis of different selenium forms by HPLC-AFS system. The atomic fluorescence (AFS) was a reliable and simple detection method for the elemental nano selenium. The elemental selenium can produce hydride in the system or can be converted to selenite with HCl/H2O2 digestion.

  16. Electrochemical behavior of chemically synthesized selenium thin film.

    Science.gov (United States)

    Patil, A M; Kumbhar, V S; Chodankar, N R; Lokhande, A C; Lokhande, C D

    2016-05-01

    The facile and low cost simple chemical bath deposition (CBD) method is employed to synthesize red colored selenium thin films. These selenium films are characterized for structural, morphological, topographical and wettability studies. The X-ray diffraction (XRD) pattern showed the crystalline nature of selenium thin film with hexagonal crystal structure. The scanning electron microscopy (SEM) study displays selenium nanoparticles ranging from 20 to 475nm. A specific surface area of 30.5m(2)g(-1) is observed for selenium nanoparticles. The selenium nanoparticles hold mesopores in the range of 1.39nm, taking benefits of the good physicochemical stability and excellent porosity. Subsequently, the electrochemical properties of selenium thin films are deliberated by cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) techniques. The selenium thin film shows specific capacitance (Cs) of 21.98Fg(-1) with 91% electrochemical stability. PMID:26896773

  17. Influence of contact time and sediment composition on the bioavailability of Cd in sediments

    International Nuclear Information System (INIS)

    Stable isotope 111Cd was spiked into sediments of different organic content levels for 3 days to 2 months. Bioavailability of spiked Cd to deposit-feeders, assessed by in vitro Cd solubilization, generally decreased with contact time but became comparable with that of background Cd after 2 months. This could be explained by the gradual transfer of Cd from the more mobile geochemical phase (carbonate associated phase) to more refractory phases (Fe–Mn oxide associated phase, and organic associated phase) within 2 months. The sedimentary organic content had a weak effect on Cd solubilization, while the distribution of Cd in carbonate or Fe–Mn oxide associated phase could have a larger influence on the solubilization of sedimentary Cd and its change with contact time. The observations in this study emphasize the need to consider Cd sequestration over time in sediments of various compositions, which would be useful in risk assessment of contaminated sediments. Highlights: ► Cd may reach equilibrium in sediments after 2 months of aging. ► Sediment composition could affect change of Cd bioavailability with contact time. ► Sedimentary organic content has a weak effect on Cd bioavailability. ► Cd associated with carbonates is more bioavailable than Cd with Fe/Mn oxides. ► Change in Cd solid speciation explains decrease of Cd bioavailability over time. - Transfer of Cd from carbonate phase to Fe–Mn oxide phase in sediments was important in affecting the decrease of Cd bioavailability over time.

  18. Effect of Selenium Supplementation on Glycemic Control and Lipid Profiles in Patients with Diabetic Nephropathy.

    Science.gov (United States)

    Bahmani, Fereshteh; Kia, Mahsa; Soleimani, Alireza; Asemi, Zatollah; Esmaillzadeh, Ahmad

    2016-08-01

    To our knowledge, data on the effects of selenium supplementation on glycemic control and lipid concentrations in patients with diabetic nephropathy (DN) are scarce. The current study was done to determine the effects of selenium supplementation on glycemic control and lipid concentrations in patients with DN. This was a randomized double-blind placebo-controlled clinical trial in which 60 patients with DN were randomly allocated into two groups to receive either 200 μg of selenium supplements (n = 30) or placebo (n = 30) daily for 12 weeks. Blood sampling was performed for the quantification of glycemic indicators and lipid profiles at the onset of the study and after 12 weeks of intervention. Selenium supplementation for 12 weeks resulted in a significant decrease in serum insulin levels (P = 0.01), homeostasis model of assessment-estimated insulin resistance (HOMA-IR) (P = 0.02), homeostasis model of assessment-estimated B cell function (HOMA-B) (P = 0.009) and a significant rise in plasma glutathione peroxidase (GPx) (P = 0.001) compared with the placebo. Taking selenium supplements had no significant effects on fasting plasma glucose (FPG), quantitative insulin sensitivity check index (QUICKI) and lipid profiles compared with the placebo. Overall, our study demonstrated that selenium supplementation for 12 weeks among patients with DN had beneficial effects on plasma GPx, serum insulin levels, HOMA-IR, and HOMA-B, while it did not affect FPG, QUICKI, and lipid profiles. PMID:26686847

  19. Mercury and selenium in fish of Fountain Creek, Colorado (USA): possible sources and implications.

    Science.gov (United States)

    Nimmo, D R; Herrmann, S J; Carsella, J S; McGarvy, C M; Foutz, H P; Herrmann-Hoesing, L M; Gregorich, J M; Turner, J A; Vanden Heuvel, B D

    2016-01-01

    Fountain Creek in Colorado USA is a major tributary that confluences with the Arkansas River at Pueblo, Colorado, the result being the tributary's influence on Arkansas River water quality affecting down-stream users. In a previous study, we found that bryophytes (aquatic plants) accumulated selenium in Fountain Creek watershed and this finding prompted us to investigate the extent of the metalloid in the whole-body tissues of fish. One hundred 11 fish (six species) were collected and analyzed for Se by inductively-coupled plasma emission mass spectrometry. Analysis of all analytical data also showed mercury in all of the fish whole bodies and selected tissues. There was a general increase in selenium but a decrease in mercury in fish with downstream travel-distance. The highest whole-body selenium was in Pueblo, Colorado (3393 µg/kg, dry weight; 906 µg/kg, wet weight); the highest mercury in fish was in the Monument Creek tributary north of Colorado Springs, Colorado (71 µg/kg, dry weight; 19 µg/kg, wet weight). In four tissues of 11 female fish captured, selenium was highest in the livers at eight sites but highest in the ovaries at three sites. Mercury was highest in the epaxial muscle at all sites. Selenium availability could be due to the watershed lithology and land uses; however, mercury could be carried by atmospheric deposition from coal-fired power plants and historic mining activities. Selenium in fish tissues and water samples were compared to U.S. national water quality criteria. PMID:27104125

  20. Dietary guidance of selenium supplementation for incipient idiopathic scoliotic patients

    Directory of Open Access Journals (Sweden)

    Jin-li GUO

    2013-11-01

    Full Text Available The study found that there was a correlation between trace element Se and idiopathic scoliosis, and selenium deficiency was probably one of the precipitating factor. According to Chinese dietary reference intakes and selenium content in different food, the plan for filling selenium is conducted, the dietary guidance of filing selenium for incipient idiopathic scoliotic patients is provided, and the disease development is observed so that the basis for etiology and prevention of idiopathic scoliosis can be provided.

  1. NAIL KERATIN AS MONITOR-TISSUE FOR SELENIUM EXPOSURE

    NARCIS (Netherlands)

    VANNOORD, PAH; MAAS, MJ; DEBRUIN, M

    1992-01-01

    Nail clippings might provide a way to monitor exposure to selenium in the recent past of an individual, since a clipping collected from a toe would reflect exposures months before actual clipping date. The relation between levels of exogenous selenium exposure and selenium levels in nail keratin was

  2. EURRECA—Estimating Selenium Requirements for Deriving Dietary Reference Values

    NARCIS (Netherlands)

    Hurst, R.; Collings, R.; Harvey, L.J.; King, M.; Hooper, L.; Bouwman, J.; Gurinovic, M.; Fairweather-Tait, S.J.

    2013-01-01

    Current reference values for selenium, an essential micronutrient, are based on the intake of selenium that is required to achieve maximal glutathione peroxidase activity in plasma or erythrocytes. In order to assess the evidence of relevance to setting dietary reference values for selenium, the EUR

  3. Selenistasis: Epistatic Effects of Selenium on Cardiovascular Phenotype

    Directory of Open Access Journals (Sweden)

    Joseph Loscalzo

    2013-01-01

    Full Text Available Although selenium metabolism is intricately linked to cardiovascular biology and function, and deficiency of selenium is associated with cardiac pathology, utilization of selenium in the prevention and treatment of cardiovascular disease remains an elusive goal. From a reductionist standpoint, the major function of selenium in vivo is antioxidant defense via its incorporation as selenocysteine into enzyme families such as glutathione peroxidases and thioredoxin reductases. In addition, selenium compounds are heterogeneous and have complex metabolic fates resulting in effects that are not entirely dependent on selenoprotein expression. This complex biology of selenium in vivo may underlie the fact that beneficial effects of selenium supplementation demonstrated in preclinical studies using models of oxidant stress-induced cardiovascular dysfunction, such as ischemia-reperfusion injury and myocardial infarction, have not been consistently observed in clinical trials. In fact, recent studies have yielded data that suggest that unselective supplementation of selenium may, indeed, be harmful. Interesting biologic actions of selenium are its simultaneous effects on redox balance and methylation status, a combination that may influence gene expression. These combined actions may explain some of the biphasic effects seen with low and high doses of selenium, the potentially harmful effects seen in normal individuals, and the beneficial effects noted in preclinical studies of disease. Given the complexity of selenium biology, systems biology approaches may be necessary to reach the goal of optimization of selenium status to promote health and prevent disease.

  4. Bio-induced solid selenium for recovery from water

    NARCIS (Netherlands)

    Hageman, S.P.W.

    2015-01-01

    Selenium in the form of selenate or selenite in wastewater needs to be removed due to its potential toxicity in the environment. Also, selenium is a valuable element that is used in several industries and current selenium resources are likely to be exhausted in less than 50 years. Waste streams cont

  5. Selenium and Prostate Cancer Prevention: Insights from the Selenium and Vitamin E Cancer Prevention Trial (SELECT

    Directory of Open Access Journals (Sweden)

    Holly L. Nicastro

    2013-04-01

    Full Text Available The Selenium and Vitamin E Cancer Prevention Trial (SELECT was conducted to assess the efficacy of selenium and vitamin E alone, and in combination, on the incidence of prostate cancer. This randomized, double-blind, placebo-controlled, 2 × 2 factorial design clinical trial found that neither selenium nor vitamin E reduced the incidence of prostate cancer after seven years and that vitamin E was associated with a 17% increased risk of prostate cancer compared to placebo. The null result was surprising given the strong preclinical and clinical evidence suggesting chemopreventive activity of selenium. Potential explanations for the null findings include the agent formulation and dose, the characteristics of the cohort, and the study design. It is likely that only specific subpopulations may benefit from selenium supplementation; therefore, future studies should consider the baseline selenium status of the participants, age of the cohort, and genotype of specific selenoproteins, among other characteristics, in order to determine the activity of selenium in cancer prevention.

  6. Speciation of selenium dietary supplements; formation of S-(methylseleno)cysteine and other selenium compounds

    International Nuclear Information System (INIS)

    Speciation of selenium is of interest because it is both essential and toxic to humans, depending on the species and the amount ingested. Following indications that selenium supplementation could reduce the incidence of some cancers, selenium-enriched yeast and other materials have been commercialized as supplements. Most dramatically however, the SELECT trial that utilized L-selenomethionine as the active supplement was terminated in 2008 and there is much debate regarding both the planning and the results of efficacy studies. Further, since dietary supplements are not regulated as pharmaceuticals, there are concerns about the quality, storage conditions, stability and selenium content in selenium supplements. Enzymatic hydrolysis enabled selenium speciation profiles to be obtained by high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and following derivatization gas chromatography with atomic emission detection (GC-AED). Coated fiber solid phase microextraction (SPME) was used to extract volatile selenium species for determination by GC-AED and GC-MS. Similar speciation patterns were observed between yeast-based supplements subject to extended storage and those heated briefly at elevated temperatures. All the yeast-based supplements and one yeast-free supplement formed S-(methylseleno)cysteine on heating. Evidence was obtained in support of the hypotheses that S-(methylseleno)cysteine is formed from a reaction between dimethyldiselenide and cysteine or cystine.

  7. Speciation of selenium dietary supplements; formation of S-(methylseleno)cysteine and other selenium compounds

    Energy Technology Data Exchange (ETDEWEB)

    Amoako, Prince O. [Department of Chemistry, University of Massachusetts Amherst, 710 N. Pleasant St., Amherst, MA 01003-9336 (United States); Uden, Peter C., E-mail: pcuden@chem.umass.edu [Department of Chemistry, University of Massachusetts Amherst, 710 N. Pleasant St., Amherst, MA 01003-9336 (United States); Tyson, Julian F. [Department of Chemistry, University of Massachusetts Amherst, 710 N. Pleasant St., Amherst, MA 01003-9336 (United States)

    2009-10-12

    Speciation of selenium is of interest because it is both essential and toxic to humans, depending on the species and the amount ingested. Following indications that selenium supplementation could reduce the incidence of some cancers, selenium-enriched yeast and other materials have been commercialized as supplements. Most dramatically however, the SELECT trial that utilized L-selenomethionine as the active supplement was terminated in 2008 and there is much debate regarding both the planning and the results of efficacy studies. Further, since dietary supplements are not regulated as pharmaceuticals, there are concerns about the quality, storage conditions, stability and selenium content in selenium supplements. Enzymatic hydrolysis enabled selenium speciation profiles to be obtained by high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and following derivatization gas chromatography with atomic emission detection (GC-AED). Coated fiber solid phase microextraction (SPME) was used to extract volatile selenium species for determination by GC-AED and GC-MS. Similar speciation patterns were observed between yeast-based supplements subject to extended storage and those heated briefly at elevated temperatures. All the yeast-based supplements and one yeast-free supplement formed S-(methylseleno)cysteine on heating. Evidence was obtained in support of the hypotheses that S-(methylseleno)cysteine is formed from a reaction between dimethyldiselenide and cysteine or cystine.

  8. Selenium speciation using HPLC-ICP-MS in selenium-enriched duckweed (Lemna minor)

    International Nuclear Information System (INIS)

    Complete text of publication follows. The HPLC-ICP-MS for speciation analysis of selenium was developed and applied to selenium enriched duckweed (Lemna minor). The duckweed in Hoagland's E-medium containing Se from sodium selenate in the concentration of 0, 5, 10, 15 and 20 mg/L was cultured. The effect of selenium supplemented concentration and cultured periods (0-8 days) were studied. The results revealed that the optimum concentration of supplemented Se and cultured period were 10 mg/L and 6 days, respectively. The Se-enriched duckweed samples (whole plant) were dried and homogenized. The 0.1 M HCl in 10% methanol extracts were analyzed. Selenium speciation was carried out by ion-pairing HPLC (2.5 mM sodium 1-butanesulfonate, 8 mM tetramethyl ammonium hydroxide and trifluoro acetic acid at pH 4.5). The organic selenium species found in the extract was selenomethylcysteine, selenomethionine and others unknown species. The percentage contributions of selenium in both species of the total selenium were 0.6 and 1.0%, respectively. It can be seen that Se-enriched duckweed can feasibility be a dietary source of Se. The authors would like to thank Center of Excellence for Innovation in Chemistry (PERCH-CIC), Commission on Higher Education, Ministry of Education for financial support.

  9. Comparing responses to different selenium sources and dosages in laying hens.

    Science.gov (United States)

    Delezie, E; Rovers, M; Van der Aa, A; Ruttens, A; Wittocx, S; Segers, L

    2014-12-01

    Developing new sources of organic Se has potential benefit for animal production and human nutrition via animal-based foods enriched in Se. The objectives of this trial were to compare L-selenomethionine with another organic Se source, Se-enriched yeast (SelPlex 2300), and sodium selenite, an inorganic Se source, against a commercial control diet. The effect of source and the dosage of Se supplementation on Se in eggs and blood variables was investigated. Ten treatments were used with 18 laying hens per group. In addition to the control diet, the control diet was supplemented with L-selenomethionine, Se-enriched yeast, or sodium selenite at 0.1, 0.3, or 0.5 mg/kg of Se. The feeding trial lasted 8 wk. Birds in the different treatment groups all showed good performance. At d 0 and 56, Se and glutathione peroxidase (GPx) were analyzed in 10 blood samples per group. After supplementing the diets for 56 d, significantly higher Se levels in serum and egg contents were reached for the Se-supplemented groups compared with the control. Supplementing 0.3 and 0.5 mg/kg of L-selenomethionine or Se-enriched yeast instead of 0.1 mg/kg significantly increased the serum Se levels, whereas no significant increase was found for sodium selenite. No effect of Se source or dosage was observed on serum GPx levels. Selenium in eggs was significantly affected by dosage and source of Se. The Se supplementation level in the feed was reflected in the eggs, with the highest and lowest values for 0.5 and 0.1 mg/kg, respectively, and values in between for the 0.3 mg/kg supplementation level. A dose response was most pronounced for L-selenomethionine, followed by Se-enriched yeast, and was least when Se was added as sodium selenite. It can be concluded that Se from organic sources was more bioavailable than the inorganic Se source as evidenced by blood and egg Se levels. Within the organic Se sources, L-selenomethionine showed higher Se transfer to eggs than Se-enriched yeast. PMID:25352676

  10. Potential Moderating Effects of Selenium on Mercury Uptake and Selenium:Mercury Molar Ratios in Fish From Oak Ridge and Savannah River Site - 12086

    International Nuclear Information System (INIS)

    Mercury contamination is an important remediation issue at the U.S. Department of Energy's (DOE) Oak Ridge Reservation and to a lesser extent at other DOE sites because of the hazard it presents, potential consequences to humans and eco-receptors, and completed pathways, to offsite receptors. Recent work has emphasized that selenium might ameliorate the toxicity of mercury, and we examine the selenium:mercury (Se:Hg) molar ratios in fish from Oak Ridge, and compare them to Se:Hg molar ratios in fish from the Savannah River. Selenium/mercury molar ratios varied considerably among and within fish species. There was considerable variation in the molar ratios for individual fish (as opposed to mean ratios by species) for freshwater fish from both sites. The inter-individual variation in molar ratios indicates that such that the molar ratios of mean Se and Hg concentrations may not be representative. Even for fish species with relatively low mercury levels, some individual fish have molar ratios less than unity, the value sometime thought to be protective. Selenium levels varied narrowly regardless of fish size, consistent with homeostatic regulation of this essential trace element. The data indicate that considerable attention will need to be directed toward variations and variances, as well as the mechanisms of the interaction of selenium and mercury, before risk assessment and risk management policies can use this information to manage mercury pollution and risk. Even so, if there are high levels of selenium in the fish from Poplar Creek on Oak Ridge, then the potential exists for some amelioration of adverse health effects, on the fish themselves, predators that eat them, and people who consume them. This work will aid DOE because it will allow managers and scientists to understand another aspect that affects fate and transport of mercury, as well as the potential effects of methylmercury in fish for human and ecological receptors. The variability within fish

  11. Selenium balance in the adult cat in relation to intake of dietary sodium selenite and organically bound selenium

    NARCIS (Netherlands)

    Todd, S.E.; Thomas, D.G.; Hendriks, W.H.

    2012-01-01

    The response of cats to dietary sodium selenite (Na2SeO3) and organically bound selenium was studied in two separate studies with four cats per treatment and three levels of selenium supplementation (targets 1.0, 1.5 and 2.0 µg/g DM) for each Se source. Whole blood and plasma selenium concentrations

  12. Effects of Water Stress on Rice Production: Bioavailability of Potassium in Soil

    Directory of Open Access Journals (Sweden)

    Jahan, Sarwar

    2013-04-01

    Full Text Available Water demand in agriculture, municipal, and industrial purposes is increasing rapidly which will pressure on future demand in agriculture. To justify less water use in rice production, we produced rice under different water levels (DWLs and justified potassium bioavailability. There were five DWLs were employed in this experiment. Besides measuring yield and yield parameters, relative water content (WRC and chlorophyll content in leaves, soil pH and bioavailability of potassium (K in soil solution were measured. Yield and yield parameters showed insignificant difference under DWLs. Different water levels did not affect weekly data of chlorophyll content and RWC in leaves. But chlorophyll content and RWC in leaves were significantly higher in week 6 or 9 than week 3. Different water levels did not affect soil pH. Our results suggested that rice can be produced under low water input without affecting yield and yield parameters and K bioavailability in soil.

  13. XAFS of supercritical fluid selenium

    International Nuclear Information System (INIS)

    Transition from liquid to vapor phase via supercritical state is investigated for fluid slenium using XAFS (X-ray Absorption Fine Structure) from the point of view of structural change as well as changes in electric conductivity and optical properties. XAFS measurements were done at European Synchrotron Radiation Facility (ESRF) in the pressure range up to 600 bar and temperature range up to 1700degC using a sapphire chamber. The results indicated that fluid selenium at the density of 1.3-1.4 g/cm3 showing XAFS spectrum characteristic of two atomic molecules changed at the density of 2 g/cm3 into that of long chain molecules. Simultaneously, change in the electric properties occurred to become metallic which was accompanied by local structural change evidenced from XAFS spectroscopy. Atomic rearrangement processes of metal to insulator transition at near supercritical density are discussed. Further progress will be made since experimental measurements are now available up to the pressure of 2000 bar at Spring-8 facility. In addition, small angle X-ray scattering data are to be made available in a beam line BLO4B2 of the facility. (S.Ohno)

  14. Impact of Selenium Supplementation on Growth and Selenium Accumulation on Spinach (Spinacia oleracea L.) Plants

    OpenAIRE

    Azadeh SAFFARYAZDI; Mehrdad LAHOUTI; Ali GANJEALI; Hassan BAYAT

    2012-01-01

    Selenium (Se) has been proved to be an essential element for humans and animals. However, less is known about its effects on plants. A hydroponic experiment was carried out to investigate the effects of selenium on growth, selenium accumulation and some physiological characteristics of spinach (Spinacia oleracea L. cv. �Missouri�) plants. Plants were grown in Hoagland nutrient solution amended with sodium selenite at 0 (control), 1, 2, 4, 6 and 10 mg.L-1 for 28 days. Growth parameters like sh...

  15. Selenium supplementation for critically ill adults

    DEFF Research Database (Denmark)

    Allingstrup, Mikkel; Afshari, Arash

    2015-01-01

    originally published in 2004 updated in 2007 and again 2015. OBJECTIVES: The primary objective was to examine the effect of nutrition supplemented with selenium or ebselen on mortality in critically ill patients.The secondary objective was to examine the relationship between selenium or ebselen...... supplementation and number of infections, duration of mechanical ventilation, length of intensive care unit stay and length of hospital stay. SEARCH METHODS: In this update, we searched the current issue of the Cochrane Central Register of Controlled Trials, the Cochrane Library (2014, Issue 5); MEDLINE (Ovid SP...... sequential analysis. MAIN RESULTS: We included six new RCTs in this review update. In total we included 16 RCTs (2084 participants) in this review. Most trials were at high risk of bias. The availability of outcome data was limited and trials involving selenium supplementation were, with the exception of one...

  16. Effect of selenium nanoparticles with different sizes in primary cultured intestinal epithelial cells of crucian carp, Carassius auratus gibelio

    Directory of Open Access Journals (Sweden)

    Wang YB

    2013-10-01

    Full Text Available Yanbo Wang, Xuxia Yan, Linglin Fu Marine Resources and Nutrition Biology Research Center, Food Quality and Safety Department, Zhejiang Gongshang University, Hangzhou, People's Republic of China Abstract: Nano-selenium (Se, with its high bioavailability and low toxicity, has attracted wide attention for its potential application in the prevention of oxidative damage in animal tissues. However, the effect of nano-Se of different sizes on the intestinal epithelial cells of the crucian carp (Carassius auratus gibelio is poorly understood. Our study showed that different sizes and doses of nano-Se have varied effects on the cellular protein contents and the enzyme activities of secreted lactate dehydrogenase, intracellular sodium potassium adenosine triphosphatase, glutathione peroxidase, and superoxide dismutase. It was also indicated that nano-Se had a size-dependent effect on the primary intestinal epithelial cells of the crucian carp. Thus, these findings may bring us a step closer to understanding the size effect and the bioavailability of nano-Se on the intestinal tract of the crucian carp. Keywords: selenium nanoparticle, intestinal epithelial cell, crucian carp, primary culture

  17. Bioavailability: implications for science/cleanup policy; FINAL

    International Nuclear Information System (INIS)

    This paper examines the role of bioavailability in risk assessment and cleanup decisions. Bioavailability refers to how chemicals ''behave'' and their ''availability'' to interact with living organisms. Bioavailability has significant implications for exposure risks, cleanup goals, and site costs. Risk to human health and the environment is directly tied to the bioavailability of the chemicals of concern

  18. Characterizing the toxicity of pulsed selenium exposure to Daphnia magna.

    Science.gov (United States)

    Hoang, Tham C; Klaine, Stephen J

    2008-03-01

    The acute toxicity of selenium (Se) to aquatic biota has been studied extensively for decades. However, most studies have used a constant concentration aqueous exposure of Se to an invertebrate species. Since constant concentration exposure of toxicants to invertebrates is unusual in the environment, episodic exposure or pulsed exposures may represent true risk to aquatic biota more accurately. This research was designed to characterize the toxicity effects of pulsed Se exposure to Daphnia magna. Selenium exposure was varied during a 21-d chronic toxicity test to examine the effects of exposure concentration, duration, and recovery on survival, growth, and reproduction of D. magna. While D. magna did not die during exposures, latent mortality was observed. Latent mortality increased with exposure concentration and duration. Hence, standard toxicity test using continuous exposures would underestimate Se toxicity. Risk assessment method using results of continuous exposure would underestimate risk of Se to biota. For double-pulse exposures, cumulative mortality on day 21 was higher when time interval between pulses was shorter. With the same total exposure time, continuous exposure caused higher toxicity than did pulsed exposures due to recovery and tolerance development in D. magna after earlier pulses. Growth and reproduction of surviving D. magna were not affected by pulsed Se exposure due to recovery of D. magna after removal of the pulses. Based on these results, risk assessment for Se should take latent effects and the effect of recovery in to account. PMID:18190947

  19. Selenium supplementation in radiotherapy patients: do we need to measure selenium levels in serum or blood regularly prior radiotherapy?

    International Nuclear Information System (INIS)

    Considering the review by Puspitasari and colleagues, an additional discussion of the endpoints of the Se supplementation studies described would be helpful. In our view, selenium can safely be given to selenium-deficient cancer patients prior to and during radiotherapy. Therefore, in order to help the radiation oncologist in decision making, we strongly advocate to determine the selenium status prior to and during a potential adjuvant selenium supplementation, e.g. when trying to ease the side-effects of radiation treatment or in the aftercare situation when the selenium status may become insufficient

  20. Selenium content in tissues and meat quality in rabbits fed selenium yeast

    Czech Academy of Sciences Publication Activity Database

    Dokoupilová, A.; Marounek, Milan; Skřivanová, V.; Březina, P.

    2007-01-01

    Roč. 52, č. 6 (2007), s. 165-169. ISSN 1212-1819 Institutional research plan: CEZ:AV0Z50450515 Keywords : rabbits * selenium * meat Subject RIV: GH - Livestock Nutrition Impact factor: 0.633, year: 2007

  1. Evaluation of Serum Selenium Levels in Children with Recurrent Febril Convulsions

    Directory of Open Access Journals (Sweden)

    Erhan Berk

    2011-12-01

    Full Text Available Introduction: The febrile convulsion (FC occurs in neurologically normal children aged between six months and five years and it is defined as convulsions occurred during fever and in the absence of central nervous system (CNS infection, electrolyte imbalance, diseases affecting directly CNS, and history of afebrile convulsion. The aims of this study were to determine the serum levels of selenium in patients with recurrent FC and to compare them with those of healthy children. Materials and Methods: The study included 61 pediatric patients diagnosed with recurrent FC. At the same session, 54 healthy children who admitted to our pediatric clinic for routine controls without history of fever and convulsion, are assigned as control group. The serum level of selenium was measured by atomic absorption spectrometric method (hydride technique.Results: Mean level of selenium was determined as 67.10±8.87 µg/L in patients and 81.99±13.13 µg/L in control group; the difference was statistically significant (p<0.05. Discussion: The lower serum levels of selenium in patients with recurrent FC may be the cause of triggering of convulsion or may contribute to its recurrence. Further studies are necessary to clarify this relationship. (Jo­ur­nal of Cur­rent Pe­di­at­rics 2011; 9: 110-5

  2. Extracellular Polymeric Substances Govern the Surface Charge of Biogenic Elemental Selenium Nanoparticles

    KAUST Repository

    Jain, Rohan

    2015-02-03

    © 2014 American Chemical Society. The origin of the organic layer covering colloidal biogenic elemental selenium nanoparticles (BioSeNPs) is not known, particularly in the case when they are synthesized by complex microbial communities. This study investigated the presence of extracellular polymeric substances (EPS) on BioSeNPs. The role of EPS in capping the extracellularly available BioSeNPs was also examined. Fourier transform infrared (FT-IR) spectroscopy and colorimetric measurements confirmed the presence of functional groups characteristic of proteins and carbohydrates on the BioSeNPs, suggesting the presence of EPS. Chemical synthesis of elemental selenium nanoparticles in the presence of EPS, extracted from selenite fed anaerobic granular sludge, yielded stable colloidal spherical selenium nanoparticles. Furthermore, extracted EPS, BioSeNPs, and chemically synthesized EPS-capped selenium nanoparticles had similar surface properties, as shown by ζ-potential versus pH profiles and isoelectric point measurements. This study shows that the EPS of anaerobic granular sludge form the organic layer present on the BioSeNPs synthesized by these granules. The EPS also govern the surface charge of these BioSeNPs, thereby contributing to their colloidal properties, hence affecting their fate in the environment and the efficiency of bioremediation technologies.

  3. Micro-spectroscopic investigation of selenium-bearing minerals from the Western US Phosphate Resource Area

    Directory of Open Access Journals (Sweden)

    Gunter Mickey E

    2005-01-01

    Full Text Available Mining activities in the US Western Phosphate Resource Area (WPRA have released Se into the environment. Selenium has several different oxidation states and species, each having varying degrees of solubility, reactivity, and bioavailability. In this study we are investigating the speciation of Se in mine-waste rocks. Selenium speciation was determined using bulk and micro-x-ray absorption spectroscopy (XAS, as well as micro-x-ray fluorescence mapping. Rocks used for bulk-XAS were ground into fine powders. Shale used for micro-XAS was broken along depositional planes to expose unweathered surfaces. The near edge region of the XAS spectra (XANES for the bulk rock samples revealed multiple oxidation states, with peaks indicative of Se(-II, Se(IV, and Se(+VI species. Micro-XANES analysis of the shale indicated that three unique Se-bearing species were present. Using the XANES data together with ab initio fitting of the extended x-ray absorption fine structure region of the micro-XAS data (micro-EXAFS the three Se-bearing species were identified as dzharkenite, a di-selenide carbon compound, and Se-substituted pyrite. Results from this research will allow for a better understanding of the biogeochemical cycling of Se in the WPRA.

  4. A pilot study of the selenium content in the soils of the endemic Dobrogea region, Romania, using nuclear and related analytical techniques

    International Nuclear Information System (INIS)

    At present, there is growing interest in the understanding of the role of selenium in human and animal metabolism. Selenium is known to be a normal component of several enzymes, proteins and some aminoacrylic transfer nucleic acids. Low levels of selenium intake are reported to cause diseases such as cardiomyopathy (Keshan disease), cancer and endemic osteoarthropathy characterized by necrosis of cartilage and dystrophy of skeletal muscles (Kaschin-Beck disease). In conjunction with the vitamin E, it removes free radicals from the living organisms. About two-to-three orders of magnitude higher levels of selenium are known to impart toxic effects. The Dobrogea Region in Romania is known for endemic cardiovascular diseases affecting domestic cattle, mostly sheep and milk cows. Soil, being the source of selenium, is responsible for its content in the whole trophic chain. A limited number of soil samples collected in the pastures (Dobrogea) were subject to epithermal neutron activation analysis at the IBR-2 pulsed fast reactor in Dubna, Russia. To verify the obtained results, the same samples were analyzed by the fluorescent extraction method, especially efficient for determination of selenium at low concentrations, at the Geological Institute of RAS in Moscow, Russia. The mean concentration of selenium was found to be equal to 0.38 ppm with a standard deviation of 0.13. The accuracy of the selenium determination was not worse than 20%. These preliminary results are not evidence of obvious selenium deficiency, however. A systematic study on a large geographical scale is strongly recommended to elucidate the problem of cattle morbidity in the examined area. (authors)

  5. Effect of chronic selenium exposure on the freshwater bivalve Corbicula fluminea

    International Nuclear Information System (INIS)

    Selenium is essential for most of living organisms. In oxic to moderately oxic fresh-waters, Se exists predominantly in the (+VI) and (+IV) oxidation states as selenate (SeO42-) and selenite (SeO32-) respectively, whereas in the biota it is incorporated as Se(-II) into seleno-proteins or amino-acids, or as elemental selenium Se(0). At low concentrations, it acts against oxidative damages mainly as the glutathione peroxidase seleno-dependant, but it may be toxic at higher levels (for example, by replacing sulphur in important biomolecules). In filter feeders, such as the freshwater bivalve Corbicula fluminea, selected as biological model, the ventilation activity is a primary limiting step that controls the water influx and therefore the delivery of contaminants. Consequently, a series of short-term experiments were performed to study the effects of different dissolved Se concentrations and forms (selenite; selenate; selenomethionine) on the ventilation activity of Corbicula fluminea and Se tissular distribution. The modification of the ventilation activity of the Se-exposed groups, in comparison to this of reference groups (not exposed to Se) varied greatly according to the form and the concentrations of the Se used. Se concentrations in tissues indicated that selenite was the less bioavailable form whereas selenomethionine displayed the opposite trend. On the basis of this set of experiments, a limited number of conditions have been selected to provide highly contrasting ventilation flow rates and selenium bioaccumulation levels, in order to study the effects of long term exposures, i) at the molecular level, by measuring bio-markers of oxidative stress (forms of glutathione, glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, and bio-marker of genotoxicity (comet assay), ii) at the (sub)cellular level by analysing Se micro-localisation in target organs and iii) at the individual level by monitoring the variation in the ventilatory flow

  6. Bioavailability of rectally administered carbamazepine mixture.

    OpenAIRE

    Neuvonen, P J; Tokola, O.

    1987-01-01

    The relative bioavailability of carbamazepine mixture was studied after oral and rectal administration to healthy subjects. The absorption was significantly slower after the rectal than after the oral route but the total bioavailability was similar provided the mixture was not defaecated within 2 h of administration. We conclude that carbamazepine can be administered rectally, e.g. to postoperative patients in doses corresponding with oral doses.

  7. Iron bioavailability from commercially available iron supplements

    OpenAIRE

    Christides, Tatiana; Wray, David; McBride, Richard; Fairweather, Rose; Sharp, Paul

    2015-01-01

    Purpose Iron deficiency anaemia (IDA) is a global public health problem. Treatment with the standard of care ferrous iron salts may be poorly tolerated, leading to non-compliance and ineffective correction of IDA. Employing supplements with higher bioavailability might permit lower doses of iron to be used with fewer side effects, thus improving treatment efficacy. Here, we compared the iron bioavailability of ferrous sulphate tablets with alternative commercial iron products, including th...

  8. Bioavailability of the Polyphenols: Status and Controversies

    OpenAIRE

    Massimo D’Archivio; Carmelina Filesi; Rosaria Varì; Beatrice Scazzocchio; Roberta Masella

    2010-01-01

    The current interest in polyphenols has been driven primarily by epidemiological studies. However, to establish conclusive evidence for the effectiveness of dietary polyphenols in disease prevention, it is useful to better define the bioavailability of the polyphenols, so that their biological activity can be evaluated. The bioavailability appears to differ greatly among the various phenolic compounds, and the most abundant ones in our diet are not necessarily those that have the best bioavai...

  9. Bioavailability and Bioequivalence in Drug Development

    OpenAIRE

    Chow, Shein-Chung

    2014-01-01

    Bioavailability is referred to as the extent and rate to which the active drug ingredient or active moiety from the drug product is absorbed and becomes available at the site of drug action. The relative bioavailability in terms of the rate and extent of drug absorption is considered predictive of clinical outcomes. In 1984, the United States Food and Drug Administration (FDA) was authorized to approve generic drug products under the Drug Price Competition and Patent Term Restoration Act base...

  10. Heavy metal bioavailability and bioaccessibility in soil

    OpenAIRE

    Dean, John

    2009-01-01

    This chapter considers the use of a variety of approaches to assess either the bioavailability or the bioaccessibility of metals in soil. The bioavailability of metals from soils is considered with respect to a series of single-extraction methods, including the use of ethylenediaminetetraacetic acid (EDTA), acetic acid, diethylenetriaminepentaacetic acid (DTPA), ammonium nitrate, calcium chloride and sodium nitrate. Then, a procedure for the recovery of metals using a three-stage sequential e...

  11. Improved bioavailability through floating microspheres of lovastatin

    OpenAIRE

    Kumar, S.; K Nagpal; Singh SK; DN Mishra

    2011-01-01

    "n Background and the purpose of the study: Lovastatin is an antihyperlipidemic agent which has low bioavailability due to the extensive first pass metabolism. It was sought to increase gastric retention of lovastatin by development of a sustained release gastroretentive drug delivery system leading to reduced fluctuation in the plasma concentration and improved bioavailability. "nMethods: Floating microspheres were prepared by emulsion solvent diffusion technique, using va...

  12. Effect of short-term zinc supplementation on zinc and selenium tissue distribution and serum antioxidant enzymes

    Directory of Open Access Journals (Sweden)

    Andrey A. Skalny

    2015-09-01

    Full Text Available Background. A significant association between Zn and Se homeostasis exists. At the same time, data on the influence of zinc supplementation on selenium distribution in organs and tissues seem to be absent. Therefore, the primary objective of the current study is to investigate the infl uence of zinc asparaginate supplementation on zinc and selenium distribution and serum superoxide dismutase (SOD and glutathione peroxidase (GPx activity in Wistar rats. Material and methods. 36 rats were used in the experiment. The duration of the experiment was 7 and 14 days in the fi rst and second series, respectively. The rats in Group I were used as the control ones. Animals in Groups II and III daily obtained zinc asparaginate (ZnA in the doses of 5 and 15 mg/kg weight, respectively. Zinc and selenium content in liver, kidneys, heart, muscle, serum and hair was assessed using inductively coupled plasma mass spectrometry. Serum SOD and GPx activity was analysed spectrophotometrically using Randox kits. Results. Intragastric administration of zinc asparaginate signifi cantly increased liver, kidney, and serum zinc content without affecting skeletal and cardiac muscle levels. Zinc supplementation also stimulated selenium retention in the rats’ organs. Moreover, a significant positive correlation between zinc and selenium content was observed. Finally, zinc asparaginate treatment has been shown to modulate serum GPx but not SOD activity. Conclusion. The obtained data indicate that zinc-induced increase in GPx activity may be mediated through modulation of selenium status. However, future studies are required to estimate the exact mechanisms of zinc and selenium interplay.

  13. Selenium exposure results in reduced reproduction in an invasive ant species and altered competitive behavior for a native ant species.

    Science.gov (United States)

    De La Riva, Deborah G; Trumble, John T

    2016-06-01

    Competitive ability and numerical dominance are important factors contributing to the ability of invasive ant species to establish and expand their ranges in new habitats. However, few studies have investigated the impact of environmental contamination on competitive behavior in ants as a potential factor influencing dynamics between invasive and native ant species. Here we investigated the widespread contaminant selenium to investigate its potential influence on invasion by the exotic Argentine ant, Linepithema humile, through effects on reproduction and competitive behavior. For the fecundity experiment, treatments were provided to Argentine ant colonies via to sugar water solutions containing one of three concentrations of selenium (0, 5 and 10 μg Se mL(-1)) that fall within the range found in soil and plants growing in contaminated areas. Competition experiments included both the Argentine ant and the native Dorymyrmex bicolor to determine the impact of selenium exposure (0 or 15 μg Se mL(-1)) on exploitation- and interference-competition between ant species. The results of the fecundity experiment revealed that selenium negatively impacted queen survival and brood production of Argentine ants. Viability of the developing brood was also affected in that offspring reached adulthood only in colonies that were not given selenium, whereas those in treated colonies died in their larval stages. Selenium exposure did not alter direct competitive behaviors for either species, but selenium exposure contributed to an increased bait discovery time for D. bicolor. Our results suggest that environmental toxins may not only pose problems for native ant species, but may also serve as a potential obstacle for establishment among exotic species. PMID:27038576

  14. Evaluation of bioavailability of food fortificants using stable isotopic methods

    International Nuclear Information System (INIS)

    Because of the complex biochemical processes affecting the bioavailability of micronutrients, it is critical to understand regional factors that affect the design of a nutritional supplementation strategy. These factors include the prevalence of multiple micronutrient deficiencies, the presence of inhibitors in indigenous foods, interactions among co-fortificants, and coexisting medical diseases affecting absorptive capacity. Each of these can lessen the bioavailability, and thus the effectiveness, of supplements. Stable isotopic studies can help determine the fate of ingested micronutrients; therefore, they can evaluate the efficacy of fortification programs, provide evidence of poor bioavailability, and point to potential remedies. This has been the focus of several recent investigations by the Baylor Stable Isotope Laboratory and a proposed project in Sri Lanka. In Indonesia an efficacy study evaluated the current program of iron fortification of flour and the proposed addition of zinc. Three groups of 30 children ages 4 to 8 were given supplemented flour (iron only, iron plus zinc sulfate, iron plus zinc oxide). Each group exhibited iron absorption of greater than 10%, but concomitant zinc administration decreased iron bioavailability. This decrease was only statistically significant for zinc sulfate, however. Zinc absorption exceeded 20% in both the zinc oxide and zinc sulfate groups. In Peru four groups of one-year old children were given supplemented rolls containing iron, iron plus vitamin A, iron plus zinc, and iron plus zinc plus vitamin A. Isotopic analysis demonstrated that iron absorption was significantly better with the addition of vitamin A, marginally worse when zinc was included, and nearly equivalent when the three supplements were given in combination. Another recent study in Peru demonstrated the efficacy of a beverage fortified with multiple micronutrients in school age children. This investigation showed that balanced micronutrient

  15. Bij geiten selenium meestal (te) hoog

    NARCIS (Netherlands)

    Smolders, E.A.A.; Eekeren, van N.J.M.; Govaerts, W.

    2010-01-01

    In het project Biogeit zijn op 13 biologische geitenbedrijven bloedmonsters onderzocht op GSH-Px als maat voor de seleniumvoorziening. Een deel van de monsters werd genomen na het toedienen van een mineralenbolus met selenium aan drachtige geiten. De bloedwaarden bij geiten zijn hoog, soms te hoog.

  16. Normal mode calculations of trigonal selenium

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; McMurry, H. L.

    1980-01-01

    The phonon dispersion relations for trigonal selenium have been calculated on the basis of a short range potential field model. Electrostatic long range forces have not been included. The force field is defined in terms of symmetrized coordinates which reflect partly the symmetry of the space group...

  17. 21 CFR 573.920 - Selenium.

    Science.gov (United States)

    2010-04-01

    ... reproduction of livestock and poultry; and (5) the manufacture and use of selenium at such levels cannot... follows: (1) In complete feed for chickens, swine, turkeys, sheep, cattle, and ducks at a level not to... not to exceed an intake of 0.7 milligram per head per day. (ii) Beef cattle: At a level not to...

  18. Genetic Determinants of Responses to Selenium Supplementation

    Science.gov (United States)

    In a cohort of healthy adults (106 M, 155 W) in eastern North Dakota, we determined the relationships of five biomarkers of selenium (Se) status (plasma Se, serum selenoprotein P [SePP], plasma glutathione peroxidase [GPX3] activity, buccal cell Se, urine Se) to genotype for four selenoproteins (cyt...

  19. Selenium in Oklahoma ground water and soil

    Energy Technology Data Exchange (ETDEWEB)

    Atalay, A.; Vir Maggon, D.

    1991-03-30

    Selenium with a consumption of 2 liters per day (5). The objectives of this study are: (1) to determine the concentrations of Se in Oklahoma ground water and soil samples. (2) to map the geographical distribution of Se species in Oklahoma. (3) to relate groundwater depth, pH and geology with concentration of Se.

  20. Uranium and selenium resistance in Cupriavidus metallidurans CH34

    Energy Technology Data Exchange (ETDEWEB)

    Avoscan, L.; Untereiner, G.; Carriere, M.; Gouget, B. [CEA Saclay, CNRS, UMR9956, Lab Pierre Sue, F-91191 Gif Sur Yvette, (France); Degrouard, J. [Univ Paris 11, Ctr Commun Microscopie Elect, CNRS, UMR8080, Orsay, (France)

    2007-07-01

    Cupriavidus metallidurans CH34, a soil bacterium, is known to resist a variety of heavy metals and metalloids. Its capacity to resist, accumulate and transform selenium (Se as selenite or selenate) and uranium (U as uranyl-carbonate and uranyl-citrate) was investigated. C. metallidurans CH34 resists to high U concentrations (up to 10 mM) whatever its speciation. However, no major accumulation could be measured: U-carbonate and U-citrate are not bio-available for the bacteria. The anaerobic response of C. metallidurans CH34 to U will be looked for. C. metallidurans CH34 resists to high Se concentrations (up to 4 mM of selenite and 8 mM of selenate). Bacteria exposed to 2 mM of selenite accumulate 25 times more Se than when they are exposed to same concentration of selenate. Se resistance is characterized by the reduction of oxy-anions in the bacteria. Selenite is reduced to elemental Se by an intracellular process, but the metabolic fate of selenate is unknown. By combining three methods of speciation (X-ray absorption spectroscopy (XANES and EXAFS), HPLC-ICP-MS and SDS-PAGE coupled with particle induced X-ray emission (PIXE)), we both identified and specified the chemical intermediates formed by this bacterium upon exposure to these oxy-anions. Two mechanisms of reduction of Se oxides in C. metallidurans CH34 were highlighted. Assimilation transforms selenite and selenate into organic Se, identified as seleno-methionine and leads to its non-specific incorporation into bacterial proteins (presence of selenious proteins). Detoxication precipitates selenite in nano-particles of elemental Se. (authors)

  1. Uranium and selenium resistance in Cupriavidus metallidurans CH34

    International Nuclear Information System (INIS)

    Cupriavidus metallidurans CH34, a soil bacterium, is known to resist a variety of heavy metals and metalloids. Its capacity to resist, accumulate and transform selenium (Se as selenite or selenate) and uranium (U as uranyl-carbonate and uranyl-citrate) was investigated. C. metallidurans CH34 resists to high U concentrations (up to 10 mM) whatever its speciation. However, no major accumulation could be measured: U-carbonate and U-citrate are not bio-available for the bacteria. The anaerobic response of C. metallidurans CH34 to U will be looked for. C. metallidurans CH34 resists to high Se concentrations (up to 4 mM of selenite and 8 mM of selenate). Bacteria exposed to 2 mM of selenite accumulate 25 times more Se than when they are exposed to same concentration of selenate. Se resistance is characterized by the reduction of oxy-anions in the bacteria. Selenite is reduced to elemental Se by an intracellular process, but the metabolic fate of selenate is unknown. By combining three methods of speciation (X-ray absorption spectroscopy (XANES and EXAFS), HPLC-ICP-MS and SDS-PAGE coupled with particle induced X-ray emission (PIXE)), we both identified and specified the chemical intermediates formed by this bacterium upon exposure to these oxy-anions. Two mechanisms of reduction of Se oxides in C. metallidurans CH34 were highlighted. Assimilation transforms selenite and selenate into organic Se, identified as seleno-methionine and leads to its non-specific incorporation into bacterial proteins (presence of selenious proteins). Detoxication precipitates selenite in nano-particles of elemental Se. (authors)

  2. Paternal selenium deficiency but not supplementation during preconception alters mammary gland development and 7,12-dimethylbenz[a]anthracene-induced mammary carcinogenesis in female rat offspring.

    Science.gov (United States)

    Guido, Luiza N; Fontelles, Camile C; Rosim, Mariana P; Pires, Vanessa C; Cozzolino, Silvia M F; Castro, Inar A; Bolaños-Jiménez, Francisco; Barbisan, Luis F; Ong, Thomas P

    2016-10-15

    Breast cancer is a global public health problem and accumulating evidence indicates early-life exposures as relevant factors in the disease risk determination. Recent studies have shown that paternal nutrition can influence offspring health including breast cancer risk. Selenium is a micronutrient with essential role in central aspects of embryogenesis, male fertility and cancer and that has been extensively studied as a chemopreventive agent in several breast cancer experimental models. Thus, we designed an animal study to evaluate whether paternal selenium deficiency or supplementation during preconception could affect the female offspring mammary gland development and breast cancer susceptibility. Male Sprague-Dawley rats were fed AIN93-G diet containing 0.15 ppm (control diet), 0.05 ppm (deficient diet) or 1 ppm (supplemented diet) of selenium for 9 weeks and mated with control female rats. Mammary carcinogenesis was induced with 7,12-dimethylbenz[a]anthracene (DMBA) in their female offspring. Paternal selenium deficiency increased the number of terminal end buds, epithelial elongation and cell proliferation in the mammary gland of the female rat offspring and these effects were associated with higher susceptibility to DMBA-induced mammary tumors (increased incidence and higher grade tumors). On the other hand, paternal selenium supplementation did not influence any of these parameters. These results highlight the importance of father's nutrition including selenium status as a relevant factor affecting daughter's breast cancer risk and paternal preconception as a potential developmental stage to start disease preventive strategies. PMID:27270969

  3. Toxicity of a binary mixture on Daphnia magna: biological effects of uranium and selenium isolated and in mixture

    International Nuclear Information System (INIS)

    Among the multiple substances that affect freshwater ecosystems, uranium and selenium are two pollutants found worldwide in the environment, alone and in mixture. The aim of this thesis work was to investigate the effect of uranium and selenium mixture on daphnia (Daphnia magna). Studying effects of a mixture requires the assessment of the effect of single substances. Thus, the first experiments were performed on single substance. Acute toxicity data were obtained: EC50 48h = 0, 39±0, 04 mg.L-1 for uranium and EC50 48h 1, 86±0, 85 mg.L-1 for selenium. Chronic effects were also studied. Data on fecundity showed an EC10 reproduction of 14±7 μg. L-1 for uranium and of 215±25 μg. L-1 for selenium. Uranium-selenium mixture toxicity experiments were performed and revealed an antagonistic effect. This study further demonstrates the importance of taking into consideration different elements in binary mixture studies such as the choice of reference models (concentration addition or independent action), statistical method, time exposure and endpoints. Using integrated parameters like energy budget was shown to be an interesting way to better understand interactions. An approach including calculation of chemical speciation in the medium and bioaccumulation measurements in the organism permits assumptions to be made on the nature of possible interactions between mixture components (toxico-dynamic et toxico-kinetic interactions). (author)

  4. Effect of anions or foods on absolute bioavailability of calcium from calcium salts in mice by pharmacokinetics

    OpenAIRE

    Ueda, Yukari; Taira, Zenei

    2013-01-01

    We studied the absolute bioavailability of calcium from calcium L-lactate in mice using pharmacokinetics, and reviewed the absolute bioavailability of calcium from three other calcium salts in mice previously studied: calcium chloride, calcium acetate, and calcium ascorbate. The results showed that calcium metabolism is linear between intravenous administration of 15 mg/kg and 30 mg/kg, and is not affected by anions. Results after oral calcium administration of 150 mg/kg showed that the intes...

  5. Nutritional control of HIV-AIDS-A case for Selenium

    Directory of Open Access Journals (Sweden)

    Parisa Kalantari

    2007-01-01

    Full Text Available Selenium (Se is a micronutrient that is incorporated into proteins. Some of the selenoenzymes such as GPXs and thioredoxin reductases exhibit glutathione peroxidase-dependent activities towards organic and inorganic peroxides. Thus, selenoenzymes play a pivotal role in mitigating oxidative stress caused by accumulation of peroxides. In this respect, selenoproteins may interfere with the transcription-driven by oxidative stress-dependent signaling mechanisms to influence the expression of redox sensitive genes, including inflammatory cytokines and HIV provirus. Several epidemiological studies support our view that Se supplementation affects transcription of HIV; however, the underlying mechanism is not elucidated. In this mini review, we consider the relationship between Se and HIV and propose possible mechanisms by which Se controls HIV transcription.

  6. Sorption–bioavailability nexus of arsenic and cadmium in variable-charge soils

    International Nuclear Information System (INIS)

    Highlights: ► Demonstrates the nexus between sorption and bioavailability of As and Cd in variable-charge soils. ► Liming variable-charge soils increase negative charge, thereby decreasing Cd bioavailability. ► Ageing of As and Cd increases their immobilization, thereby decreasing bioavailability. ► Phosphate enhances desorption and phytoavailability of As from sheep dip soil. ► Metal(loid)s transfer to food chain can be managed by controlling sorption reactions. -- Abstract: In this work, the nexus between sorption and bioavailability of arsenic (As) and cadmium (Cd) as affected by soil type, soil pH, ageing, and mobilizing agents were examined. The adsorption of As and Cd was examined using a number of allophanic and non-allophanic soils which vary in their charge components. The effect of pH and ageing on the bioavailability of As and Cd was examined using spiked soils in a plant growth experiment. The effect of phosphate (P)-induced mobility of As on its bioavailability was examined using a naturally contaminated sheep dip soil. The results indicated that the adsorption of both As and Cd varied amongst the soils, and the difference in Cd adsorption is attributed to the difference in surface charge. An increase in soil pH increased net negative charge by an average of 45.7 mmol/kg/pH thereby increasing cation (Cd) adsorption; whereas, the effect of pH on anion (As) adsorption was inconsistent. The bioavailability of As and Cd decreased by 3.31- and 2.30-fold, respectively, with ageing which may be attributed to increased immobilization. Phosphate addition increased the mobility and bioavailability of As by 4.34- and 3.35-fold, respectively, in the sheep dip soil. However, the net effect of P on As phytoavailability depends on the extent of P-induced As mobilization in soils and P-induced competition for As uptake by roots. The results demonstrate the nexus between sorption and bioavailability of As and Cd in soils, indicating that the effects of

  7. Sorption–bioavailability nexus of arsenic and cadmium in variable-charge soils

    Energy Technology Data Exchange (ETDEWEB)

    Bolan, Nanthi, E-mail: Nanthi.Bolan@unisa.edu.au [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA (Australia); CRC for Contamination Assessment and Remediation in the Environment, University of South Australia, Mawson Lakes, SA (Australia); Mahimairaja, Santiago [Department of Environmental Science, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu (India); Kunhikrishnan, Anitha [Chemical Safety Division, Department of Agro-Food Safety, National Academy of Agricultural Science, Suwon-si, Gyeonggi-do 441-707 (Korea, Republic of); Naidu, Ravi [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA (Australia); CRC for Contamination Assessment and Remediation in the Environment, University of South Australia, Mawson Lakes, SA (Australia)

    2013-10-15

    Highlights: ► Demonstrates the nexus between sorption and bioavailability of As and Cd in variable-charge soils. ► Liming variable-charge soils increase negative charge, thereby decreasing Cd bioavailability. ► Ageing of As and Cd increases their immobilization, thereby decreasing bioavailability. ► Phosphate enhances desorption and phytoavailability of As from sheep dip soil. ► Metal(loid)s transfer to food chain can be managed by controlling sorption reactions. -- Abstract: In this work, the nexus between sorption and bioavailability of arsenic (As) and cadmium (Cd) as affected by soil type, soil pH, ageing, and mobilizing agents were examined. The adsorption of As and Cd was examined using a number of allophanic and non-allophanic soils which vary in their charge components. The effect of pH and ageing on the bioavailability of As and Cd was examined using spiked soils in a plant growth experiment. The effect of phosphate (P)-induced mobility of As on its bioavailability was examined using a naturally contaminated sheep dip soil. The results indicated that the adsorption of both As and Cd varied amongst the soils, and the difference in Cd adsorption is attributed to the difference in surface charge. An increase in soil pH increased net negative charge by an average of 45.7 mmol/kg/pH thereby increasing cation (Cd) adsorption; whereas, the effect of pH on anion (As) adsorption was inconsistent. The bioavailability of As and Cd decreased by 3.31- and 2.30-fold, respectively, with ageing which may be attributed to increased immobilization. Phosphate addition increased the mobility and bioavailability of As by 4.34- and 3.35-fold, respectively, in the sheep dip soil. However, the net effect of P on As phytoavailability depends on the extent of P-induced As mobilization in soils and P-induced competition for As uptake by roots. The results demonstrate the nexus between sorption and bioavailability of As and Cd in soils, indicating that the effects of

  8. Bioavailability enhancers of herbal origin: an overview.

    Science.gov (United States)

    Kesarwani, Kritika; Gupta, Rajiv; Mukerjee, Alok

    2013-04-01

    Recently, the use of herbal medicines has been increased all over the world due to their therapeutic effects and fewer adverse effects as compared to the modern medicines. However, many herbal drugs and herbal extracts despite of their impressive in-vitro findings demonstrates less or negligible in-vivo activity due to their poor lipid solubility or improper molecular size, resulting in poor absorption and hence poor bioavailability. Nowadays with the advancement in the technology, novel drug delivery systems open the door towards the development of enhancing bioavailability of herbal drug delivery systems. For last one decade many novel carriers such as liposomes, microspheres, nanoparticles, transferosomes, ethosomes, lipid based systems etc. have been reported for successful modified delivery of various herbal drugs. Many herbal compounds including quercetin, genistein, naringin, sinomenine, piperine, glycyrrhizin and nitrile glycoside have demonstrated capability to enhance the bioavailability. The objective of this review is to summarize various available novel drug delivery technologies which have been developed for delivery of drugs (herbal), and to achieve better therapeutic response. An attempt has also been made to compile a profile on bioavailability enhancers of herbal origin with the mechanism of action (wherever reported) and studies on improvement in drug bioavailability, exhibited particularly by natural compounds. PMID:23620848

  9. Bioavailability of nanoparticulate hematite to Arabidopsis thaliana

    International Nuclear Information System (INIS)

    The environmental effects and bioavailability of nanoparticulate iron (Fe) to plants are currently unknown. Here, plant bioavailability of synthesized hematite Fe nanoparticles was evaluated using Arabidopsis thaliana (A. thaliana) as a model. Over 56-days of growing wild-type A. thaliana, the nanoparticle-Fe and no-Fe treatments had lower plant biomass, lower chlorophyll concentrations, and lower internal Fe concentrations than the Fe-treatment. Results for the no-Fe and nanoparticle-Fe treatments were consistently similar throughout the experiment. These results suggest that nanoparticles (mean diameter 40.9 nm, range 22.3–67.0 nm) were not taken up and therefore not bioavailable to A. thaliana. Over 14-days growing wild-type and transgenic (Type I/II proton pump overexpression) A. thaliana, the Type I plant grew more than the wild-type in the nanoparticle-Fe treatment, suggesting Type I plants cope better with Fe limitation; however, the nanoparticle-Fe and no-Fe treatments had similar growth for all plant types. -- Highlights: ► Iron nanoparticles were synthesized and assessed for bioavailability to Arabidopsis. ► Arabidopsis grew better in the presence of EDTA-bound iron than nanoparticulate iron. ► Arabidopsis grew the same in the presence of nanoparticulate iron compared to no iron. -- Synthesized iron nanoparticles were not bioavailable to Arabidopsis thaliana in agar nutrient media

  10. Species and distribution of inorganic selenium in the Bohai Sea

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    For studying geochemical behavior of selenium, a marine investigation was conducted in September 1998 cruise in the Bohai Sea. Horizontal and vertical distributions of inorganic selenium and selenite were studied. The inorganic selenium varied from 0.73 to 2.41 nmol/L, with an average of 1.31 nmol/L; while selenite varied from 0.18 to 0.72 nmol/L with an average of 0.47 nmol/L. The average ratio of selenite to selenate was 0.68, and selenate was the predominant species of inorganic selenium in the most study area. Concentrations of inorganic selenium and selenite decreased with distance from the coast. No apparent variations of the concentration between surface and bottom was shown. There were two water masses in the area, one from the Huanghe (Yellow) River and other from the Yellow Sea. Of the two,Huanghe River was the major source of inorganic selenium.

  11. Selenium Recycling in the United States in 2004

    Science.gov (United States)

    George, Micheal W.; Wagner, Lorie A.

    2009-01-01

    The vast majority of selenium consumption in the United States is in dissipative uses, such as alloys, animal feeds, fertilizers, glass decolorizer, and pigments. The nondissipative use as a photoreceptor for xerographic copiers is declining. As a result of a lack of a substantial supply of selenium-containing scrap, there are no longer selenium recycling facilities in the United States. Selenium-containing materials collected for recycling, primarily selenium-containing photocopier drums, are exported for processing in other countries. Of the estimated 350 metric tons (t) of selenium products that went to the U.S. market in 2004, an estimated 300 t went to dissipative uses. An estimated 4 t was recovered from old scrap and exported for recycling.

  12. BARIUM BIOAVAILABILITY AS THE CHLORIDE, SULFATE, OR CARBONATE SALT IN THE RAT

    Science.gov (United States)

    This study was conducted to determine how the bioavailability of a low concentration of barium (Ba) in drinking water is affected by anion speciation. Male Sprague Dawley rats weighing 250-300 grams were maintained on a diet of less than 1 mg Ba/kg of food for at least 1 month pr...

  13. The effects of selenium on lycopersicon esculentum mill. seedlings

    International Nuclear Information System (INIS)

    This study was planned to contribute the views examining the physiological mechanisms of selenium-induced growth reductions with regard to selenium and plant nutrient interactions. Growth inhibition in the seedlings and the changes in nutrient compositions of epidermal cells with administration of increasing concentrations of selenium were investigated at the initial growth stage, which is the most stress-sensitive stage, of plant. The effects of selenium on Lycopersicon esculentum Mill. seedlings were investigated by EDX (Energy Dispersive X-Ray Microanalysis) analysis of the regions, approximately 450 mm x 500 mm in size, with use of low-vacuum (24 Pascal) Scanning Electron Microscope, and SEM images were obtained. Increasing concentrations of selenium in the nutrient solution led to decreased cell growth particularly in the hypocotyl and roots, and to increased selenium content in the cells. The growth inhibitions were found at the selenium concentrations of 100 ppm. Development of the glandular hairs in the hypocotyl epidermal system was significantly reduced with the administration of 200 ppm of selenium. Development of the absorbing hairs in the roots was decreased in parallel with the increasing selenium concentrations in the nutrient solution; and because the development of the root is often limited to only to the development of radicula at the selenium concentrations of 500 and 1000 ppm, no absorbing hairs was found in these roots. Some macro- and micronutrient contents of radicle and hypocotyl epidermal cells were changed in response to selenium toxicity. In conclusion, 200 ppm of selenium administered in the form of SeO/sub 2/ was certainly toxic for the initial growth period of Lycopersicon esculentum cv. H-2274. (author)

  14. Synthesis and characterization of single crystalline selenium nanowire arrays

    International Nuclear Information System (INIS)

    Ordered selenium nanowire arrays with diameters about 40 nm have been fabricated by electrodeposition using anodic porous alumina templates. As determined by X-ray diffraction, Raman spectra, electron diffraction and high-resolution transmission electron microscopy, selenium nanowires have uniform diameters, which are fully controllable. Single crystalline trigonal selenium nanowires have been obtained after postannealing at 180 deg. C. These nanowires are perfect with a c-axis growth orientation. The optical absorption spectra reveal two types of electron transition activity

  15. Test Automation Selenium WebDriver using TestNG

    OpenAIRE

    Bindal, Purnima; Gupta, Sonika

    2014-01-01

    Test automation tools (softwares) are used to control the execution of tests (Application Under Test) and then comparing actual outcomes to the predicted outcomes. Examples of Test Automation tools are HP Quick Test Professional, Selenium, Test Complete, SOAP UI etc. Selenium is a suite of tools for cross-platform automated testing of web applications. It runs on many browsers and operating systems and can be controlled by many programming languages and testing frameworks. Selenium W...

  16. Selenium Poisoning of Wildlife and Western Agriculture: Cause and Effect

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.E.

    2000-02-01

    This project examined the hypothesis that selenium contamination is not the principal cause of the decline of endemic fish species in the Upper Colorado Basin. Activities employed to test this hypothesis included a reconnaissance of locations altered by recent road construction, a re-interpretation of available literature regarding selenium toxicity, and the interpretation of unpublished data obtained from the Upper Colorado Basin Fish Recovery Program. The project demonstrates that most of the evidence implicating selenium is circumstantial.

  17. Sorption behavior of selenium on humic acid under increasing selenium concentration or increasing solid/liquid ratio

    International Nuclear Information System (INIS)

    The sorption of selenium (Se) on humic acid (HA) was investigated in order to better understand the fate of stable and radioactive Se in soils and sediments. An ultrafiltration technique was used to determine size distributions of HA-sorbed-Se when increasing Se concentration and solid/liquid ratio. The results showed that the Se sorption onto HA followed the Freundlich isotherm. No solid/liquid ratio-dependence was observed especially when F and n obtained using the 2 and 0.82, respectively. In addition, since dissolved HA increased with decreased ionic strength in the HA suspension, ionic strength could promote aggregation of HA. The conformational change of HA could affect the sorption behavior of Se on HA

  18. Distribution of Selenium in Corn and Its Relationship With Soil Selenium in Yutangba Mini—Landscape

    Institute of Scientific and Technical Information of China (English)

    朱建明; 毛大均; 等

    2000-01-01

    Within the range of 0.01 km2 mini-landscape in Yutangba,Enshi,Hubei Province,the content of Se in corn is very high,The average Se contents in root,stem,leaf and seed of corn were estimated to be 4.36±3.27mg.kg,3.08±2.24mg/kg,9.74±7.62mg/kg,and 8.07±5.02mg/kg,respectively.The research results show that there is a significantly poistive correlation between corn selenium and soil selenium,and thus according to the distribtuion of Se in corn.Three subregions can be divided in Yutangba,The content of selenium in corn is controlled by that of soil.A little variation in selenium content in soil will lead to a considerable corresponding variation in corn.So it is deduced that the organs that contain relatively high Se in plants may be used as a sensitive selenium indicator of Se levels in the environment.

  19. Radiolabeled iron in soybeans: intrinsic labeling and bioavailability of iron to rats from defatted flour

    International Nuclear Information System (INIS)

    Soybeans can be efficiently labeled with radiolabeled iron by supplying the iron via a nutrient culture medium as an iron salt or as a chelate. By using dual labeled iron and EDTA, it was determined that none of the chelator was transported to the shoots with the iron. Therefore, the use of chelated iron as the iron source in the nutrient medium should not affect assessments of bioavailability of iron from plants. Bioavailability (determined from whole-body retention curves of 59Fe in rats) of iron from defatted soy flour was relatively high and addition of vitamin C did not significantly enhance absorption of iron from defatted soy flour

  20. Bioavailability of omega-3 long-chain polyunsaturated fatty acids from foods

    DEFF Research Database (Denmark)

    Mu, Huiling

    2008-01-01

    Increasing recognition of the importance of the omega-3 long chain polyunsaturated fatty acids (LCPUFA) has caused greater attention about dietary intake of these fatty acids. Fatty fish is the major dietary source of these fatty acids. Because of the low intake of fish at many places, foods...... enriched with omega-3 LCPUFA can be good alternatives to improve the intake of these fatty acids. Effects of lipid structures and food matrices on bioavailability of omega-3 LCPUFA have been investigated. Short term studies showed that both lipid structure and food matrix affect the bioavailability of...

  1. Chemical speciation and bioavailability in radioecological research

    International Nuclear Information System (INIS)

    The science of radioecology in the framework of the CEC Radiation Protection Research Action is considered to serve to unravel the specific interaction between the ecosphere and the radioactivity as a chemical event, in order to deliver the reliable data for the dose calculation, to reveal the most sensitive eco-compartments (trophic level) in a foodchain, and to develop the skills needed in the technique of remedial actions, based onsound scientific principles. In this context speciation and bio-availability plays a more predominant role than originally envisaged. These parameters are however often not very well quantified or considered in the genuine context (ecosystem) were the changes in speciation or bio-availability occur. This paper is an attempt to elucidate some of the basic principles behind speciation and bio-availability. (orig.)

  2. Conceptual Model for Selenium Cycling in the Great Salt Lake

    Science.gov (United States)

    Johnson, W. P.; Conover, M. R.; Wurtsbaugh, W. A.; Adams, J.

    2006-12-01

    The conceptual model for Selenium cycling in the Great Salt Lake was developed to guide investigations in support of determining an open water selenium standard for the Great Salt Lake. The motivation to determine this particular selenium standard derives from public concern for a plan to allow disposal of reverse osmosis (RO) concentrate in the GSL, which would contain elevated concentrations of major and trace elements, including selenium. The development of an open water standard for selenium requires a working knowledge of the biological significance of existing selenium concentrations in the Great Salt Lake, as well as a working understanding of the likely changes of these concentrations over time given existing and proposed loads to the system. This working knowledge" is being represented in a conceptual model that accounts for selenium in various stocks" in the system (e.g. water, sediment, biota) and the flow" of selenium between stocks (e.g., precipitation and settling, volatilization, bioconcentration). It illustrates the critical pathway of selenium in the Great Salt Lake from water, to microorganisms, to brine shrimp and brine flies, to birds, and to their eggs. It also addresses the complexity of the GSL system: a) Spatially diverse, being comprised by four distinct bays and two layers, with major differences in salinity among their waters. b) Temporally dynamic, due to seasonal and inter-annual variations in runoff. The conceptual model is presently descriptive, but will serve as the basis for a semi-quantitative model that will be fed by data accumulated during subsequent investigations.

  3. Volatile Selenium Flux in the Great Salt Lake

    Science.gov (United States)

    Diaz, X.; Johnson, W. P.

    2006-12-01

    Volatilization of selenium has been proven to be the major source of selenium vapor from oceans and estuaries and it may be the major mechanism of permanent selenium removal from the Great Salt Lake (other than brine shrimp harvest). However, the volatilization flux of selenium from the Great Salt Lake has not been previously measured due to challenges of analysis in this hyper-saline environment. This work presents results from recent field studies examining the spatial distribution of volatile selenium (geographical and with depth) in the South Arm (main body) of the Great Salt Lake. The analyses involved collection of volatile selenium in a cryo-focusing trap system via sparging with helium. The cryo-trapped volatile selenium was digested with nitric acid and analyzed by ICP-MS. The results show concentrations of volatile selenium that are much greater than values reported for marine estuaries and oceans. Volatile selenium flux to the atmosphere was determined using mass transport equations corrected to simulate the highly saline environment of the South Arm of the Great Salt Lake.

  4. Ecological Importance of Insects in Selenium Biogenic Cycling

    Directory of Open Access Journals (Sweden)

    Nadezhda Golubkina

    2014-01-01

    Full Text Available Selenium is an essential trace element for animal and human beings. Despite the importance of insects in most ecosystems and their significant contribution to the biological cycling of trace elements due to high abundance, population productivity, and diverse ecosystem functions, surprisingly little information is available on selenium bioaccumulation by these arthropods. This review considers selenium essentiality and toxicity to insects as well as insects’ contribution to selenium trophic transfer through the food chains. Data on Se accumulation by insects of the Dniester River Valley with no anthropogenic Se loading reveal typically low Se content in necrophagous insects compared to predators and herbivores and seasonal variations in Se accumulation.

  5. Accumulation and metabolism of selenium by yeast cells.

    Science.gov (United States)

    Kieliszek, Marek; Błażejak, Stanisław; Gientka, Iwona; Bzducha-Wróbel, Anna

    2015-07-01

    This paper examines the process of selenium bioaccumulation and selenium metabolism in yeast cells. Yeast cells can bind elements in ionic from the environment and permanently integrate them into their cellular structure. Up to now, Saccharomyces cerevisiae, Candida utilis, and Yarrowia lipolytica yeasts have been used primarily in biotechnological studies to evaluate binding of minerals. Yeast cells are able to bind selenium in the form of both organic and inorganic compounds. The process of bioaccumulation of selenium by microorganisms occurs through two mechanisms: extracellular binding by ligands of membrane assembly and intracellular accumulation associated with the transport of ions across the cytoplasmic membrane into the cell interior. During intracellular metabolism of selenium, oxidation, reduction, methylation, and selenoprotein synthesis processes are involved, as exemplified by detoxification processes that allow yeasts to survive under culture conditions involving the elevated selenium concentrations which were observed. Selenium yeasts represent probably the best absorbed form of this element. In turn, in terms of wide application, the inclusion of yeast with accumulated selenium may aid in lessening selenium deficiency in a diet. PMID:26003453

  6. Bioavailability of Plant-Derived Antioxidants

    Directory of Open Access Journals (Sweden)

    Ehab A. Abourashed

    2013-11-01

    Full Text Available Natural products with antioxidant properties have been extensively utilized in the pharmaceutical and food industry and have also been very popular as health-promoting herbal products. This review provides a summary of the literature published around the first decade of the 21st century regarding the oral bioavailability of carotenoids, polyphenols and sulfur compounds as the three major classes of plant-derived antioxidants. The reviewed original research includes more than 40 compounds belonging to the above mentioned classes of natural antioxidants. In addition, related reviews published during the same period have been cited. A brief introduction to general bioavailability-related definitions, procedures and considerations is also included.

  7. Bioavailability of cadmium from linseed and cocoa

    OpenAIRE

    Hansen, Max; Rasmussen, Rie Romme; Sloth, Jens Jørgen

    2014-01-01

    The exposure of the European population to cadmium from food is high compared with the tolerable weekly intake of 2.5 μg/kg bodyweight set by EFSA in 2009. Only few studies on the bioavailability of cadmium from different food sources has been performed but this information in very important for the food authorities in order to give correct advises to the population. The aim of this study was to investigate the bioavailability of cadmium from whole linseed, crushed linseed, cocoa and cadmium ...

  8. Bioavailability is improved by enzymatic modification of the citrus flavonoid hesperidin in humans

    DEFF Research Database (Denmark)

    Nielsen, Inge Lise F; Chee, Winnie S S; Poulsen, Lea;

    2006-01-01

    Hesperidin is the predominant polyphenol consumed from citrus fruits and juices. However, hesperidin is proposed to have limited bioavailability due to the rutinoside moiety attached to the flavonoid. The aim of this study was to demonstrate in human subjects that the removal of the rhamnose grou...... bioavailability of hesperidin was modulated by enzymatic conversion to hesperetin-7-glucoside, thus changing the absorption site from the colon to the small intestine. This may affect future interventions concerning the health benefits of citrus flavonoids.......Hesperidin is the predominant polyphenol consumed from citrus fruits and juices. However, hesperidin is proposed to have limited bioavailability due to the rutinoside moiety attached to the flavonoid. The aim of this study was to demonstrate in human subjects that the removal of the rhamnose group...

  9. Budgets for total and bioavailable nitrogen in the North Sea-Baltic Sea transition zone

    DEFF Research Database (Denmark)

    Jørgensen, L.; Markager, Stiig; Maar, Marie

    Budget calculations show that bioavailability of dissolved organic nitrogen (DON) is a key factor in management of eutrophication in open marine areas as it governs the importance of local loadings versus nitrogen received from adjacent seas and hence if eutrophication is a local or regional...... problem. Nitrogen is the limiting nutrient in the Belt Sea and the Kattegat. At the same time the area is heavily affected by eutrophication. Hence, a number of abatement measures have been implanted in Denmark, Sweden and Germany in order to reduce the anthropogenic nitrogen loadings. In this context it...... is essential to know how much of the nitrogen comes from local sources and how much is imported for the adjacent seas. We have therefore made nitrogen budgets for both total nitrogen and bioavailable nitrogen covering the area. Bioavailable nitrogen consists of inorganic N, particulate organic N and...

  10. Improvement of Selenium Status of Pasture Crops

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel

    1984-01-01

    Selenium was applied to pasture crops in a field experiment (1) by foliar application of 10 g Se/ha as selenite in the spring, (2) or by 5 g Se/ha in the spring plus 5 g in early August, (3) as selenite-enriched calcium ammonium nitrate (CAN) at 4 g Se/ha after each cut, and (4) as 4 g Se after...

  11. Biofortification of food chain with selenium

    OpenAIRE

    Seppänen, Mervi; Kontturi, Juha; Hartikainen, Helinä

    2010-01-01

    Selenium (Se) is an essential micronutrient for humans and animals which is circulated to food chain via crop plants. Agronomic biofortification with Se is used in areas where the soil Se content is low and Se deficiency causes health problems. Brassica species are efficient in accumulation of soil Se and therefore an attractive choice of species for biofortification. Se uptake and translocation was studied in B. rapa and B. napus in field experiments applied with 0, 6 or 20 mg...

  12. Mouse Assay for Determination of Arsenic Bioavailability in Contaminated Soils

    Science.gov (United States)

    Background: Accurate assessment of human exposure estimates from arsenic-contaminated soils depends upon estimating arsenic (As) soil bioavailability. Development of bioavailability assays provides data needed for human health risk assessments and supports development and valida...

  13. Impact of Selenium Supplementation on Growth and Selenium Accumulation on Spinach (Spinacia oleracea L. Plants

    Directory of Open Access Journals (Sweden)

    Azadeh SAFFARYAZDI

    2012-11-01

    Full Text Available Selenium (Se has been proved to be an essential element for humans and animals. However, less is known about its effects on plants. A hydroponic experiment was carried out to investigate the effects of selenium on growth, selenium accumulation and some physiological characteristics of spinach (Spinacia oleracea L. cv. �Missouri� plants. Plants were grown in Hoagland nutrient solution amended with sodium selenite at 0 (control, 1, 2, 4, 6 and 10 mg.L-1 for 28 days. Growth parameters like shoot and root fresh weight, shoot and root dry weight, total dry weight, shoot and root length increased by 17, 15, 38, 19, 18 and 34 percent in response to the lowest concentration of Se (1 mg L-1, respectively over control. However, application of higher Se concentrations reduced these parameters as compared to control. Selenium up to 1 mg L-1 enhanced the levels of chlorophyll a and chlorophyll b by 87 and 165 percent, respectively, while higher levels of Se exert toxic effects. Total phenolic compounds in leaves increased directly by increasing the level of Se and plants treated with 10 mg. L-1 Se had the highest values. Selenium, sodium and calcium content increased, while potassium content decreased, by increasing selenium treatments. The highest amounts of Se in shoots (3.89 mg g-1 DW and roots (4.27 mg g-1 DW were obtained for the highest concentration of Se (10 mg L-1. The present results suggested the beneficial effects of Se on spinach growth and also its contribute ion to improving the nutritional value of spinach for livestock and human nutrition.

  14. Zinc and selenium nutritional status in vegetarians.

    Science.gov (United States)

    de Bortoli, Maritsa Carla; Cozzolino, Silvia Maria Franciscato

    2009-03-01

    A vegetarian diet may have beneficial effects on human health, however when it is not well-balanced may be deficient in some nutrients, as minerals for example. The aim of the present study was to assess the nutritional status of zinc and selenium in vegetarians in the city of São Paulo. A cross-sectional study was performed, and the inclusion criteria were age > or = 18 years, both gender, no use of food or pharmaceutical supplements. Thirty vegetarian, of both genders, mean age of 27 years and 4.5 years of vegetarianism had performed the study, and their mean BMI was 21.5. Zinc plasma concentration was 71 and 62.5 microg/dL for men and women and erythrocyte concentration was 37 microg/gHb for both genders. Selenium concentration was 73.5 and 77.3 microg/L in plasma and 51.4 and 66.9 microg/L in erythrocytes for men and women, respectively. These biochemical values show that, according to the references, selenium blood levels are adequate and zinc concentration in erythrocytes is deficient in the studied population. For this reason, vegetarians should be constantly assessed and receive nutritional support to reduce the effects of inadequate zinc status. PMID:18953504

  15. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of these isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separation of 32S vs. 34S were 1.127 for H2S, 1.048 for COS, 0.838 for SF4, and 1.058 for CH3SH. Relative volatilities of 32S vs. 34S are 1.0006 for COS and 0.9976 for SF4. There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H2Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produced separated isotopes with an effect similar to that found for sulfur in SF4. 8 refs., 2 tabs

  16. Selenium in biology: facts and medical perspectives.

    Science.gov (United States)

    Köhrl, J; Brigelius-Flohé, R; Böck, A; Gärtner, R; Meyer, O; Flohé, L

    2000-01-01

    Several decades after the discovery of selenium as an essential trace element in vertebrates approximately 20 eukaryotic and more than 15 prokaryotic selenoproteins containing the 21st proteinogenic amino acid, selenocysteine, have been identified, partially characterized or cloned from several species. Many of these proteins are involved in redox reactions with selenocysteine acting as an essential component of the catalytic cycle. Enzyme activities have been assigned to the glutathione peroxidase family, to the thioredoxin reductases, which were recently identified as selenoproteins, to the iodothyronine deiodinases, which metabolize thyroid hormones, and to the selenophosphate synthetase 2, which is involved in selenoprotein biosynthesis. Prokaryotic selenoproteins catalyze redox reactions and formation of selenoethers in (stress-induced) metabolism and energy production of E. coli, of the clostridial cluster XI and of other prokaryotes. Apart from the specific and complex biosynthesis of selenocysteine, selenium also reversibly binds to proteins, is incorporated into selenomethionine in bacteria, yeast and higher plants, or posttranslationally modifies a catalytically essential cysteine residue of CO dehydrogenase. Expression of individual eukaryotic selenoproteins exhibits high tissue specificity, depends on selenium availability, in some cases is regulated by hormones, and if impaired contributes to several pathological conditions. Disturbance of selenoprotein expression or function is associated with deficiency syndromes (Keshan and Kashin-Beck disease), might contribute to tumorigenesis and atherosclerosis, is altered in several bacterial and viral infections, and leads to infertility in male rodents. PMID:11076017

  17. Modelling chelate-Induced phytoextraction: functional models predicting bioavailability of metals in soil, metal uptake and shoot biomass

    Directory of Open Access Journals (Sweden)

    Pasqualina Sacco

    Full Text Available Chelate-induced phytoextraction of heavy metals from contaminated soils requires special care to determine, a priori, the best method of chelate application, in terms of both dose and timing. In fact, the chelate dose must assure the bioavailability of the metal to the plant without increasing leaching risk and giving toxic effects. Three mathematical models are here proposed for usefully interpreting the processes taking place: a increased soil bioavailability of metals by chelants; b metal uptake by plants; c variation in plant biomass. The models are implemented and validated using data from pot and lysimeter trials. Both the chelate dose and the time elapsed since its application affected metal bioavailability and plant response. Contrariwise, the distribution strategy (single vs. split application seems to produce significant differences both in plant growth and metal uptake, but not in soil metal bioavailability. The proposed models may help to understand and predict the chelate dose – effect relationship with less experimental work.

  18. Cytotoxicity of selenium nanoparticles in rat dermal fibroblasts

    Directory of Open Access Journals (Sweden)

    Ramos JF

    2012-07-01

    Full Text Available Joseph F Ramos,1 Thomas J Webster21School of Engineering, Center of Biomedical Engineering, 2School of Engineering and Department of Orthopedics, Brown University, Providence, RI, USABackground: Ventilator-associated pneumonia is a deadly nosocomial infection caused by contaminated endotracheal tubes. It has been shown that polyvinyl chloride (PVC, the endotracheal tube substrate coated with elemental selenium nanoparticles reduces bacterial adherence and proliferation on PVC by over 99%. However, it is not known if selenium nanoparticles elicit a cytotoxic effect in vitro. The purpose of this study was to investigate the cytotoxic effects of PVC coated with selenium nanoparticles on fibroblasts, which are mammalian cells central to endotracheal tube intubation.Methods: Different concentrations of selenium nanoparticles were precipitated onto the PVC surface by reduction of selenium salts using glutathione. Characterization of PVC coated with selenium nanoparticles was done by scanning electron microscopy, energy dispersive x-ray, and contact angle measurements. For the cytotoxicity experiments, fibroblasts were seeded at a density of 5000 cm2 onto PVC coated with three different concentrations of selenium nanoparticles (high, medium, low and incubated for 4 hours (adhesion as well as for 24 hours and 72 hours (proliferation. The half-maximal inhibitory concentration (IC50 value was determined after 72 hours using an ultrahigh concentration. MTT assays were used to assess cell viability at the indicated time points.Results: The three concentrations of selenium nanoparticles did not elicit a cytotoxic effect after 72 hours (P < 0.01, n = 3. It was found that the IC50 value was at the ultrahigh concentration of selenium nanoparticles. The nanoparticulate elemental selenium concentration previously shown to decrease the function of bacteria was shown not to cause a cytotoxic effect on fibroblasts in vitro.Conclusion: These findings demonstrate

  19. Animal versus human oral drug bioavailability: Do they correlate?

    OpenAIRE

    Musther, Helen; Olivares-Morales, Andrés; Hatley, Oliver J. D.; Liu, Bo; Rostami Hodjegan, Amin

    2014-01-01

    Oral bioavailability is a key consideration in development of drug products, and the use of preclinical species in predicting bioavailability in human has long been debated. In order to clarify whether any correlation between human and animal bioavailability exist, an extensive analysis of the published literature data was conducted. Due to the complex nature of bioavailability calculations inclusion criteria were applied to ensure integrity of the data. A database of 184 compounds was assemb...

  20. Bioavailability of cadmium from linseed and cocoa

    DEFF Research Database (Denmark)

    Hansen, Max; Sloth, Jens Jørgen; Rasmussen, Rie Romme

    In Denmark and EU the exposure of cadmium from food is at a level that is relatively close to the Tolerable Daily Intake (TDI). This report describes an investigation of the bioavailability of cadmium in selected food items known to contain high levels of cadmium. The purpose was to provide data ...... crushed linseed nor the intake of cocoa and chocolate....

  1. Contact Sensitivity and Bioavailability of Chlorocresol

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Larsen, Elfinn; Carlsen, Lars; Andersen, K. E.

    1985-01-01

    Chlorocresol sensitization from 5 topical preparations was determined in guinea pigs using the cumulative contact enhancement test. Chlorocresol 5% in olive oil/acetone (4/1), and 5% in aqueous suspension stabilized with carbomer 941 were more sensitizing (55% and 60% of the animals positive, res....... No simple relationship between the sensitization rates and the calculated bioavailability was observed with the preparations tested....

  2. INTERSPECIFIC HYBRIDIZATION FOR INCREASED BIOAVAILABILITY OF ANTIOXIDANTS

    Science.gov (United States)

    Many flavonoids, including anthocyanins and flavonols, exist in plants as conjugates of sugars. Evidence suggests that the bioavailability of flavonoids in mammalian diets is a function of the sugar moiety, and that glucosides may be the preferred conjugates. Fruit of the American cranberry (Vaccini...

  3. 21 CFR 522.2100 - Selenium, vitamin E injection.

    Science.gov (United States)

    2010-04-01

    ... or deep intramuscular injection in divided doses in 2 or more sites in the gluteal or cervical... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Selenium, vitamin E injection. 522.2100 Section... § 522.2100 Selenium, vitamin E injection. (a)(1) Specifications. The drug is an emulsion containing...

  4. ESR Measurements on the Polymerization of Liquid Selenium

    NARCIS (Netherlands)

    Koningsberger, D.C.; Wolput, J.H.M.C. van; Rieter, P.C.U.

    1971-01-01

    In an earlier communication ESR measurements on de-oxygenized selenium were announced. The present paper reports on further ESR measurements on liquid de-oxygenized selenium carried out in a temperature interval 240}o{C < T < 420}o{C. The g-value of the ESR signal is found to be 2.03 +/- 0.02. The t

  5. Selenium enrichment pattern in flowering Chinese cabbage, cabbage and asparagus

    NARCIS (Netherlands)

    Mo, H.Z.; Yang Zhu, Yang; Zhang, M.

    2006-01-01

    CONCLUSIONS - Within a certain range, selenium accumulation in three studied vegetables was lineally correlated with spraying concentration. However, a too high concentration caused the reduction of vegetable output and damage in quality. - Twice spraying with lower concentration of selenium was a b

  6. Importance of selenium status in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Nicole Ebner

    2015-02-01

    Full Text Available Overactivity of the immune system may be a worthwhile therapeutic target for implementing prognostic improvements. Therefore the impact of lipopolysaccharide (LPS desensitization on survival may help in the development of novel therapies. An understanding of the pathophysiology of the trace element selenium may complement such approaches, as recent data suggest that inflammatory responses are selenium-dependent.

  7. Mercury and selenium in wild and experimental seals

    NARCIS (Netherlands)

    Ven, van de W.S.M.; Koeman, J.H.; Svenson, A.

    1979-01-01

    This paper describes the tissue distribution of inorganic mercury, organic mercury selenium in Dutch and British seals as well as in seals which were dosed with methylmercury under experimental conditions. In the experimental animals, a time-related increase of both mercury and selenium was found in

  8. CANOLA CROP TAKES UP SELENIUM PROVIDES BIOFUEL AND FEED SUPPLEMENT

    Science.gov (United States)

    Many of the Brassica plant taxi that are candidates for phytoremediation of selenium also produce products that be used for refining into biodiesel, as well as selenium enriched animal feeds. These include canola (Brassica napus) that is planted in the Westside soils of central California (Oxalis si...

  9. Vanadium bioavailability in soils amended with blast furnace slag

    International Nuclear Information System (INIS)

    Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800 mg V kg−1) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment

  10. Vanadium bioavailability in soils amended with blast furnace slag.

    Science.gov (United States)

    Larsson, Maja A; Baken, Stijn; Smolders, Erik; Cubadda, Francesco; Gustafsson, Jon Petter

    2015-10-15

    Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800 mg V kg(-1)) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment. PMID:25917693

  11. Vanadium bioavailability in soils amended with blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Maja A., E-mail: maja.larsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Baken, Stijn, E-mail: stijn.baken@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Smolders, Erik, E-mail: erik.smolders@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Cubadda, Francesco, E-mail: francesco.cubadda@iss.it [Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161 (Italy); Gustafsson, Jon Petter, E-mail: jon-petter.gustafsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Division of Land and Water Resources Engineering, KTH Royal Institute of Technology, Brinellvägen 28, 100 44 Stockholm (Sweden)

    2015-10-15

    Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800 mg V kg{sup −1}) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment.

  12. Stabilizing Agents for Drug Nanocrystals: Effect on Bioavailability

    Directory of Open Access Journals (Sweden)

    Annika Tuomela

    2016-05-01

    Full Text Available Drug nanocrystals are a versatile option for drug delivery purposes, and while the number of poorly soluble drug materials is all the time increasing, more research in this area is performed. Drug nanocrystals have a simple structure—a solid drug core is surrounded by a layer of stabilizing agent. However, despite the considerably simple structure, the selection of an appropriate stabilizer for a certain drug can be challenging. Mostly, the stabilizer selection is based purely on the requirement of physical stability, e.g., maintaining the nanosized particle size as long as possible after the formation of drug nanocrystals. However, it is also worth taking into account that stabilizer can affect the bioavailability in the final formulation via interactions with cells and cell layers. In addition, formation of nanocrystals is only one process step, and for the final formulation, more excipients are often added to the composition. The role of the stabilizers in the final formulation can be more than only stabilizing the nanocrystal particle size. A good example is the stabilizer’s role as cryoprotectant during freeze drying. In this review, the stabilizing effect, role of stabilizers in final nanocrystalline formulations, challenges in reaching in vitro–in vivo correlation with nanocrystalline products, and stabilizers’ effect on higher bioavailability are discussed.

  13. Pollutants bioavailability and toxicological risk from microplastics to marine mussels

    International Nuclear Information System (INIS)

    Microplastics represent a growing environmental concern for the oceans due to their potential of adsorbing chemical pollutants, thus representing a still unexplored source of exposure for aquatic organisms. In this study polyethylene (PE) and polystyrene (PS) microplastics were shown to adsorb pyrene with a time and dose-dependent relationship. Results also indicated a marked capability of contaminated microplastics to transfer this model PAH to exposed mussels Mytilus galloprovincialis; tissue localization of microplastics occurred in haemolymph, gills and especially digestive tissues where a marked accumulation of pyrene was also observed. Cellular effects included alterations of immunological responses, lysosomal compartment, peroxisomal proliferation, antioxidant system, neurotoxic effects, onset of genotoxicity; changes in gene expression profile was also demonstrated through a new DNA microarray platform. The study provided the evidence that microplastics adsorb PAHs, emphasizing an elevated bioavailability of these chemicals after the ingestion, and the toxicological implications due to responsiveness of several molecular and cellular pathways to microplastics. - Highlights: • Polyethylene and polystyrene microplastics efficiently adsorbed pyrene. • Pyrene adsorbed on microplastics was readily bioavailable for mussels. • Microplastics affected several molecular and cellular pathways. • Potential toxicological risk can arise from virgin and contaminated microplastics. - Pyrene adsorbed on microplastics is accumulated in tissues of marine mussels. Transcriptional and cellular responses highlight the potential risk of virgin and contaminated polymers

  14. Ionic liquid-induced synthesis of selenium nanoparticles

    International Nuclear Information System (INIS)

    A simple wet chemical method has been used to synthesize selenium nanoparticles by the reaction of ionic liquid with sodium selenosulphate, a selenium precursor, in the presence of polyvinyl alcohol stabilizer, in aqueous medium. The method is capable of producing spherical selenium nanoparticles in the size range of 76-150 nm under ambient conditions. This is a first report on the production of nano-selenium assisted by an ionic liquid. The synthesized nanoparticles can be separated easily from the aqueous sol by a high-speed centrifuge machine, and can be re-dispersed in an aqueous medium. The synthesized selenium nanoparticles have been characterized by X-ray diffraction, energy dispersive X-ray analysis, differential scanning calorimetry and transmission electron microscopy techniques.

  15. Level of selenium intake the region of algiers ration

    International Nuclear Information System (INIS)

    In this present work, we have measured the selenium content in different food frequently consumed in the region of Algiers, a nutritional deficiency in selenium may be a risk factor for cardiovascular diseases, the function mainly as a protection agent against the toxic effects of free radicals, selenium are related to its presence at the active site of the enzyme glutathion peroxidase. Freeze-dried samples of food were put in cell and measured by INAA (Instrumental Neutron Activation Analysis). We have established the annual consumption of selenium for five socio-professional categories (private employers, high commissioned officers, medium commissioned officers, workers, maneuvers ), on the basis of data given by government agencies. We have determined as mean daily consumption of selenium by people in region of Algiers was 130 ug per day

  16. Genome-wide association study of serum selenium concentrations

    DEFF Research Database (Denmark)

    Gong, Jian; Hsu, Li; Harrison, Tabitha;

    2013-01-01

    Selenium is an essential trace element and circulating selenium concentrations have been associated with a wide range of diseases. Candidate gene studies suggest that circulating selenium concentrations may be impacted by genetic variation; however, no study has comprehensively investigated this...... hypothesis. Therefore, we conducted a two-stage genome-wide association study to identify genetic variants associated with serum selenium concentrations in 1203 European descents from two cohorts: the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening and the Women’s Health Initiative (WHI). We...... tested association between 2,474,333 single nucleotide polymorphisms (SNPs) and serum selenium concentrations using linear regression models. In the first stage (PLCO) 41 SNPs clustered in 15 regions had p < 1 × 10−5. None of these 41 SNPs reached the significant threshold (p = 0.05/15 regions = 0...

  17. Extraction-X-ray fluorescence determination of selenium

    International Nuclear Information System (INIS)

    Easy to use, rapid x-ray fluorescence method of selenium determination is developed. The method is based on preliminary extraction of Se with dithiophosphoric acid and evaporation of the extract on a porous matrix. To choose the optimal conditions of extraction the effect of organic reagent concentration, of the pH aqueous phase and the shaking up time on selenium extraction volume is studied. Selenium quantitative extraction is observed in the process of selenium extraction from highly acid media. It is shown that the optimal conditions for Se(4) extraction by means of ammonium diethyldithiophosphate are the following: reagent concentration is 1x10-3 M; pH 0-1.5; the shaking up time is 20 min. The given methods are applied for selenium determination in the bottoms the formations of the Noksa river. The absolute detection limit is 0.1 μg

  18. [Selenium determination in blood plasma samples of high performance athletes].

    Science.gov (United States)

    Logemann, E; Krützfeldt, B; Rokitzki, L

    1989-01-01

    Cooperating with the department "Sport- und Leistungsmedizin" of the university hospital of Freiburg/Brsg. we investigated the problem whether endurance stress leads to a significant change in the selenium blood concentration of athletes. We took blood samples of 13 test persons (11 men, 2 women) before, immediately after and 2 hours following a marathon course. The analyses of the concentration of selenium in plasma were performed by atomic absorption spectrometry AAS (molybdenum-coated graphite tube technique with L'vov platform as well as matrix modification with nickel nitrate in order to thermally stabilize the selenium). The selenium level of the plasma samples ranged between 41 and 153 micrograms/L. Our experiments have shown that running a marathon course does not lead to significant changes in the standard selenium plasma concentrations of the athletes. PMID:2818554

  19. Selenium content in wheat and estimation of the selenium daily intake in different regions of Algeria

    International Nuclear Information System (INIS)

    In this work, we have measured the selenium content in wheat produced locally in eight different regions of Algeria from east to west, and we have established the annual consumption of selenium for five socio-professional categories. Instrumental neutron activation analysis is used. The selenium levels in wheat samples varied from 21 (Tiaret) to 153 μg/kg (Khroub), with a mean value about 52 μg/kg. The mean of selenium daily consumption from ingestion of wheat per person in the eight regions varied from 32 to 52 μg/day which is close to the minimal FAO recommendation. - Highlights: ► Cereals and cereal products represent a staple food in Algeria. ► The objective of this study is to determine the Se intake in wheat produced locally. ► The concentration of Se in the wheat reflects the level of the Se in regional soils. ► The mean of Se daily consumption is close to the minimal WHO/FAO recommendation.

  20. Selenium supplemented fertilization - effects on the selenium content of foods and the selenium intake in Finland

    OpenAIRE

    Eurola, M.; Ekholm, P.; Venäläinen, E.-J.

    2005-01-01

    The effect of Se fertilization was distinct. Winter cereals were not affected as much as spring cereals due to the different cultivation and fertilization practice. The variation between the farms was large. In organic cultivation Se content of cereals was low.

  1. Selenium and Preeclampsia: a Systematic Review and Meta-analysis.

    Science.gov (United States)

    Xu, Min; Guo, Dan; Gu, Hao; Zhang, Li; Lv, Shuyan

    2016-06-01

    Conflicting results exist between selenium concentration and preeclampsia. The role of selenium in the development of preeclampsia is unclear. We conducted a meta-analysis to compare the blood selenium level in patients with preeclampsia and healthy pregnant women, and to determine the effectiveness of selenium supplementation in preventing preeclampsia. We searched PubMed, ScienceDirect, the Cochrane Library, and relevant references for English language literature up to November 25, 2014. Mean difference from observational studies and relative risk from randomized controlled trials were meta-analyzed by a random-effect model. Thirteen observational studies with 1515 participants and 3 randomized controlled trials with 439 participants were included in the meta-analysis. Using a random-effect model, a statistically significant difference in blood selenium concentration of -6.47 μg/l (95 % confidence interval (CI) -11.24 to -1.7, p = 0.008) was seen after comparing the mean difference of observational studies. In randomized controlled trials, using a random-effect model, the relative risk for preeclampsia was 0.28 (0.09 to 0.84) for selenium supplementation (p = 0.02). Evidence from observational studies indicates an inverse association of blood selenium level and the risk of preeclampsia. Supplementation with selenium significantly reduces the incidence of preeclampsia. However, more prospective clinical trials are required to assess the association between selenium supplementation and preeclampsia and to determine the dose, beginning time, and duration of selenium supplementation. PMID:26516080

  2. Aqueous, solid and gaseous partitioning of selenium in an oxic sandy soil under different microbiological states

    Energy Technology Data Exchange (ETDEWEB)

    Darcheville, O. [Laboratory of Radioecology and Ecotoxicology (LRE), IRSN/DEI/SECRE, Building 186, Cadarache, B.P. 3, 13115 Saint Paul-lez-Durance Cedex (France)], E-mail: olivia.darcheville@irsn.fr; Fevrier, L. [Laboratory of Radioecology and Ecotoxicology (LRE), IRSN/DEI/SECRE, Building 186, Cadarache, B.P. 3, 13115 Saint Paul-lez-Durance Cedex (France)], E-mail: laureline.fevrier@irsn.fr; Haichar, F.Z. [CEA Cadarache, DSV/IBEB/SBVME/LEMIRE, UMR 6191 CNRS/CEA/Univ Aix-Marseille, 13108 Saint Paul-lez-Durance (France)], E-mail: feth-el-zahar.haichar@cea.fr; Berge, O. [CEA Cadarache, DSV/IBEB/SBVME/LEMIRE, UMR 6191 CNRS/CEA/Univ Aix-Marseille, 13108 Saint Paul-lez-Durance (France)], E-mail: odile.berge@cea.fr; Martin-Garin, A. [Laboratory of Radioecology and Ecotoxicology (LRE), IRSN/DEI/SECRE, Building 186, Cadarache, B.P. 3, 13115 Saint Paul-lez-Durance Cedex (France)], E-mail: arnaud.martin-garin@irsn.fr; Renault, P. [INRA, UMR 1114 INRA-UAPV Climat, Sol et Environnement, Domaine Saint Paul, Site Agroparc, 84914 Avignon (France)], E-mail: pierre.renault@avignon.inra.fr

    2008-06-15

    The aim of this study was to investigate the role of microorganisms on the behaviour of selenium in natural soil maintained under strictly aerobic conditions. Six-day batch experiments were performed with soils constrained to different microbiological states, either by sterilisation or by adding organic substrates. Selenium was added to the soil as selenite. The distribution of selenium in the gaseous, liquid and solid phases of the batch was measured. Selenium partitioning between the various solid phases was investigated by chemical sequential extractions. Active microorganisms played major effects on the distribution of selenium within the soil. On the one hand, microorganisms could promote selenium volatilisation (in relatively small amounts), leading to the spreading of selenium compounds outside the soil. On the other hand, microbial activities increased both amount of selenium retained by the soil and the strength of its retention (less exchangeable selenium), making selenium less susceptible to remobilisation.

  3. Use of chemical methods to assess Cd and Pb bioavailability to the snail Cantareus aspersus: A first attempt taking into account soil characteristics

    International Nuclear Information System (INIS)

    Highlights: → New methodology to identify chemical method able to assess metal bioavailability to snails. → Bioavailability of cadmium and lead to snails was determined by assessing accumulation kinetics. → Toxicokinetics were used to as a measure of bioavailability and related with chemical measures of metal availability. → Bioavailability of cadmium and lead was affected by different pH and organic matter content but not by clay content. → Concentrations of CaCl2 extract and total dissolved metal estimate were not able to predict bioavailability to the snails. - Abstract: Bioavailability is a key parameter in conditioning contaminant transfer to biota. However, in risk assessment of terrestrial contamination, insufficient attention is being paid to the influence of soil type on trace metal bioavailability. This paper addresses the influence of soil properties on the chemical availability of cadmium (Cd) and lead (Pb) (CaCl2 extraction and ionic activity) and bioavailability (accumulation kinetics) to the land snail Cantareus aspersus. Snails were exposed to nine contaminated soils differing by a single characteristic (pH or organic matter content or clay content) for 28 days. Toxicokinetic models were applied to determine metal uptake and excretion rates in snails and multivariate regression was used to relate uptake parameters to soil properties. The results showed that alkalinisation of soil and an increase of the organic matter content decreased Pb and Cd bioavailability to snails whereas kaolin clay had no significant influence. The CaCl2-extractable concentrations tended to overestimate the effects of pH when used to explain metal uptake rate. We conclude that factors other than those controlling the extractable fraction affect metal bioavailability to snails, confirming the requirement of biota measurements in risk assessment procedures.

  4. Importance of suspended sediment (SPS) composition and grain size in the bioavailability of SPS-associated pyrene to Daphnia magna.

    Science.gov (United States)

    Xia, Xinghui; Zhang, Xiaotian; Zhou, Dong; Bao, Yimeng; Li, Husheng; Zhai, Yawei

    2016-07-01

    Hydrophobic organic compounds (HOCs) tend to associate with suspended sediment (SPS) in aquatic environments; the composition and grain size of SPS will affect the bioavailability of SPS-associated HOCs. However, the bioavailability of HOCs sorbed on SPS with different compositions and grain sizes is not well understood. In this work, passive dosing devices were made to control the freely dissolved concentration of pyrene, a typical HOC, in the exposure systems. The effect of pyrene associated with amorphous organic carbon (AOC), black carbon (BC), and minerals of SPS with grain sizes of 0-50 μm and 50-100 μm on the immobilization and enzymatic activities of Daphnia magna was investigated to quantify the bioavailability of pyrene sorbed on SPS with different grain sizes and compositions. The results showed that the contribution of AOC-, BC-, and mineral-associated pyrene to the total bioavailability of SPS-associated pyrene was approximately 50%-60%, 10%-29%, and 20%-30%, respectively. The bioavailable fraction of pyrene sorbed on the three components of SPS was ordered as AOC (22.4%-67.3%) > minerals (20.1%-46.0%) > BC (9.11%-16.8%), and the bioavailable fraction sorbed on SPS of 50-100 μm grain size was higher than those of 0-50 μm grain size. This is because the SPS grain size will affect the ingestion of SPS and the SPS composition will affect the desorption of SPS-associated pyrene in Daphnia magna. According to the results obtained in this study, a model has been developed to calculate the bioavailability of HOCs to aquatic organisms in natural waters considering both SPS grain size and composition. PMID:27112726

  5. Impact of selenium and other trace elements on the endangered adult razorback sucker.

    Science.gov (United States)

    Hamilton, Steven J; Holley, Kathy M; Buhl, Kevin J; Bullard, Fern A; Weston, L Ken; McDonald, Susan F

    2002-01-01

    A study was conducted with endangered the razorback sucker (Xyrauchen texanus) to determine if environmental exposure to selenium in flooded bottomland sites affected survival, growth, and egg-hatching success. Adults were stocked at three sites adjacent to the Colorado River near Grand Junction, Colorado, in July 1996: hatchery ponds at Horsethief Canyon State Wildlife Area (referred to here as Horsethief; the reference site), a diked tertiary channel at Adobe Creek, and North Pond at Walter Walker State Wildlife Area (WWSWA). Fish were collected in April 1997 and spawned. After two spawnings adults from the three sites were held at Horsethief for an 86-day selenium depuration period. Selenium concentrations at Horsethief were 1.4-3.0 microg/L in water, 0.8-0.9 microg/g in sediment, 4.5 microg/g in muscle plug, and 6.0 microg/g in eggs; at Adobe Creek, <0.7-4.5 microg/L in water, 1.2-2.5 microg/g in sediment, 16-20 microg/g in zooplankton, 9.6 microg/g in muscle plug, and 40 microg/g in eggs; and at North Pond, 3.2-17 microg/L in water, 16-94 microg/g in sediment, 32-48 microg/g in zooplankton, 14 microg/g in muscle plug, and 55 microg/g in eggs. During the depuration period, when adults from Adobe Creek and North Pond were held at Horsethief, the fish lost 7%-13% of their selenium burden in 59 days and 14%-21% in 86 days. Larvae from North Pond adults had the most deformities, followed by Adobe Creek adults, with the fewest deformities found in the Horsethief adults. PMID:12203951

  6. Bioaccessibility of selenium after human ingestion in relation to its chemical species and compartmentalization in maize.

    Science.gov (United States)

    Mombo, Stéphane; Schreck, Eva; Dumat, Camille; Laplanche, Christophe; Pierart, Antoine; Longchamp, Mélanie; Besson, Philippe; Castrec-Rouelle, Maryse

    2016-06-01

    Selenium is a micronutrient needed by all living organisms including humans, but often present in low concentration in food with possible deficiency. From another side, at higher concentrations in soils as observed in seleniferous regions of the world, and in function of its chemical species, Se can also induce (eco)toxicity. Root Se uptake was therefore studied in function of its initial form for maize (Zea mays L.), a plant widely cultivated for human and animal food over the world. Se phytotoxicity and compartmentalization were studied in different aerial plant tissues. For the first time, Se oral human bioaccessibility after ingestion was assessed for the main Se species (Se(IV) and Se(VI)) with the BARGE ex vivo test in maize seeds (consumed by humans), and in stems and leaves consumed by animals. Corn seedlings were cultivated in hydroponic conditions supplemented with 1 mg L(-1) of selenium (Se(IV), Se(VI), Control) for 4 months. Biomass, Se concentration, and bioaccessibility were measured on harvested plants. A reduction in plant biomass was observed under Se treatments compared to control, suggesting its phytotoxicity. This plant biomass reduction was higher for selenite species than selenate, and seed was the main affected compartment compared to control. Selenium compartmentalization study showed that for selenate species, a preferential accumulation was observed in leaves, whereas selenite translocation was very limited toward maize aerial parts, except in the seeds where selenite concentrations are generally high. Selenium oral bioaccessibility after ingestion fluctuated from 49 to 89 % according to the considered plant tissue and Se species. Whatever the tissue, selenate appeared as the most human bioaccessible form. A potential Se toxicity was highlighted for people living in seleniferous regions, this risk being enhanced by the high Se bioaccessibility. PMID:26387097

  7. Effects of dietary selenium source, storage time, and temperature on the quality of quail eggs.

    Science.gov (United States)

    Baylan, Mikail; Canogullari, Sibel; Ayasan, Tugay; Copur, Gulsen

    2011-11-01

    We report the effects of time of storage, temperature, and supplementation with sodium selenite- and selenium-enriched yeast on the quality of quail eggs. For this study, 90 10-week-old female Japanese quails (Coturnix coturnix japonica) with similar body size were caged individually and randomly divided into five groups of 18 quails each. One group was fed a normal diet and served as control. A second group was supplemented with 0.2 mg/kg sodium selenite (In-Se) and three groups supplemented with 0.1, 0.2, and 0.3 mg/kg of a commercially available selenium-enriched yeast (O-Se1, O-Se2, and O-Se3, respectively). The eggs were collected at third and fourth weeks of the experiment and were stored at 4°C and 20°C for 0, 15, 30, and 45 days. Extension of the storage time to 45 days at 20°C resulted in significant deterioration of egg quality. The albumen Haugh unit (HU), pH, albumen index, yolk index, and egg weight loss were the most important parameters influenced by the nature of the selenium sources, storage time, and temperature. Storage time and temperature were also significant for egg weight loss, HU, and albumen and yolk indexes. The results show that supplementation with selenium yeast significantly affected shell weight, shell thickness, HU, albumen index, yolk index, and pH. The HU decreased with increased storage time and temperature. Higher levels of Se-yeast administration resulted in greater HU compared to the selenite and control groups. PMID:21136198

  8. Iodine and selenium migration through argillaceous rocks

    International Nuclear Information System (INIS)

    Deep argillaceous formations are considered as potential host rock for high-level radioactive waste repository. Based on safety assessment calculations, active selenium (79Se) and iodine (129I) from high level radioactive waste might be ones of the major dose contributors due to their longevity and their anionic character. However, because of their high sensitivity to redox condition, a special attention to the oxidation state of these elements is required. A comparative study on the diffusion properties of selenium and iodine through argillaceous rocks was realized with the aim to determine the effects of both the redox conditions and the mineralogy on the migration of these two elements. For these purposes, we have studied two argillaceous rocks: Toarcian argillite from Tournemire (France) and Opalinus clay (OPA) from the Mont-Terri (Switzerland). The study of the iodide migration allowed to confirm the control on the iodide retention of both oxidized pyrite and natural organic matter. A kinetic control of the iodide sorption is also suspected. We focus the selenium study on the more oxidized species, Se(IV) and Se(VI). The Se(IV) migration is strongly dependant from oxido-reduction processes. Indeed, the Se(IV) diffusion experiments through Tournemire argillite and OPA indicated a significant reduction associated to Fe(II). The Se(VI) study evidenced a behavior dependant from the initial concentration: at the highest concentration, no significant retention was observed while the retention is significant at the lowest concentration. Furthermore, spectroscopic analyses tend to show a low Se(VI) reduction at the Fe contact. However, biotic origin cannot be excluded. (author)

  9. Distinct reactivities on segmented selenium nanorods.

    Science.gov (United States)

    Liu, Ming-Han; Chen, Yun-Wen; Kuo, Jer-Lai; Wang, C R Chris

    2015-09-18

    We demonstrate a new approach to synthesize several unique nanostructures by tuning the selective reactivities on individual symmetry-breaking segmented selenium nanorods (SBS-SeNRs). The segment-selective reactions from thiolated silane endowed the formation of float-like SBS-SeNR@SiO2 with a silica coating on the t-Se segment. Several other unique nanostructures were further synthesized by applying other selective reactions, such as Se chemical removal and nanogold deposition. Such a segmented nanomaterial of SBS-SeNRs acts as a new chemical template for preparing various segmented nanocomposites. PMID:26236788

  10. Oral bioavailability of curcumin: problems and advancements.

    Science.gov (United States)

    Liu, Weidong; Zhai, Yingjie; Heng, Xueyuan; Che, Feng Yuan; Chen, Wenjun; Sun, Dezhong; Zhai, Guangxi

    2016-09-01

    Curcumin is a natural compound of Curcuma longa L. and has shown many pharmacological activities such as anti-inflammatory, anti-oxidant in both preclinical and clinical studies. Moreover, curcumin has hepatoprotective, neuroprotective activities and protects against myocardial infarction. Particularly, curcumin has also demonstrated favorite anticancer efficacy. But limiting factors such as its extremely low oral bioavailability hampers its application as therapeutic agent. Therefore, many technologies have been developed and applied to overcome this limitation. This review described the main physicochemical properties of curcumin and summarized the recent studies in the design and development of oral delivery systems for curcumin to enhance the solubility and oral bioavailability, including liposomes, nanoparticles and polymeric micelles, phospholipid complexes, and microemulsions. PMID:26942997

  11. Mobility and Bioavailability of Radionuclides in Soils

    International Nuclear Information System (INIS)

    It is crucial to understand the behavior of radionuclides in the environment, their potential mobility and bioavailability related to long-term persistence, radiological hazards, and impact on human health. Such key information is used to develop strategies that support policy decisions. The environmental behavior of radionuclides depends on ecosystem characteristics. A given soil’s capacity to immobilize radionuclides has been proved to be the main factor responsible for their resulting activity concentrations in plants. The mobility and bioavailability of radionuclides in soils is complex, depending on clay-sized soil fraction, clay mineralogy, organic matter, cation exchange capacity, pH and quantities of competing cations. Moreover, plant species have different behaviors regarding radionuclide absorption depending on soil and plan characteristics

  12. Preliminary Study on the Standard of Selenium Content in Agricultural Products

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-yuan; YOU Yong; GUO Qing-quan; WANG Yong-hong; DENG Shi-lin

    2012-01-01

    With the improvement of living standards, people pay more attention to the agricultural products with health protection function, and the selenium-rich agricultural products attract more and more consumers. The main biological role of selenium is to resist oxidation and inflammatory response, mainly focusing on resisting aging, preventing cardiovascular disease, protecting eyesight, counteracting or destroying the toxic properties, preventing cancer and thyroid disease. In most areas of China, there is a widespread shortage of selenium, thus producing selenium-rich agricultural products to provide natural selenium-rich health food to the areas in need of selenium, has gradually become a new hot spot of China’s health food industry, but high content of selenium in food is detrimental to human body, even leads to selenium intoxication, and artificially adding inorganic selenium is difficult to guarantee that the selenium content of agricultural products is not exceeded. According to human body’s daily demand for selenium in dietetics and the content of selenium in agricultural products in the Chinese food composition table, we put forward the recommendations on the standard of selenium in agricultural products, in order to provide the basis for China to formulate the health standard of selenium content in selenium-rich agricultural products.

  13. Bioavailability of energy-effluent materials in coastal ecosystems

    International Nuclear Information System (INIS)

    An attempt is made to study the long-term effects of effluents from coastal and offshore nuclear power plants. The original intent of the program was to integrate approaches in chemistry, ocean transport, and biological uptake to quantify the variables that regulate biological availability of energy-effluent materials. Initial work was focused on the fate and effects of copper. In later research, the authors examined the basic environmental variables controlling the bioavailability of energy-related contaminants. They investigated how factors such as dissolved organic compounds, suspended particles, and sediment binding affected chemical speciation and how chemical speciation, in turn, influenced the availability of metals and radionuclides to marine invertebrates. They developed a hydrodynamic model to predict sediment and contaminant transport, and they quantified the bioconcentration of synthetic-fuel residuals in plankton

  14. Bioavailability enhancers of herbal origin: An overview

    OpenAIRE

    Kesarwani, Kritika; Gupta, Rajiv

    2013-01-01

    Recently, the use of herbal medicines has been increased all over the world due to their therapeutic effects and fewer adverse effects as compared to the modern medicines. However, many herbal drugs and herbal extracts despite of their impressive in-vitro findings demonstrates less or negligible in-vivo activity due to their poor lipid solubility or improper molecular size, resulting in poor absorption and hence poor bioavailability. Nowadays with the advancement in the technology, novel drug...

  15. Bioavailability of Plant-Derived Antioxidants

    OpenAIRE

    Abourashed, Ehab A.

    2013-01-01

    Natural products with antioxidant properties have been extensively utilized in the pharmaceutical and food industry and have also been very popular as health-promoting herbal products. This review provides a summary of the literature published around the first decade of the 21st century regarding the oral bioavailability of carotenoids, polyphenols and sulfur compounds as the three major classes of plant-derived antioxidants. The reviewed original research includes more than 40 compounds belo...

  16. Bioavailability and biodistribution of nanodelivered lutein.

    Science.gov (United States)

    Kamil, Alison; Smith, Donald E; Blumberg, Jeffrey B; Astete, Carlos; Sabliov, Cristina; Oliver Chen, C-Y

    2016-02-01

    The aim of the study was to evaluate the ability of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NP) to enhance lutein bioavailability. The bioavailability of free lutein and PLGA-NP lutein in rats was assessed by determining plasma pharmacokinetics and deposition in selected tissues. Lutein uptake and secretion was also assessed in Caco-2 cells. Compared to free lutein, PLGA-NP increased the maximal plasma concentration (Cmax) and area under the time-concentration curve in rats by 54.5- and 77.6-fold, respectively, while promoting tissue accumulation in the mesenteric fat and spleen. In comparison with micellized lutein, PLGA-NP lutein improved the Cmax in rat plasma by 15.6-fold and in selected tissues by ⩾ 3.8-fold. In contrast, PLGA-NP lutein had a lower uptake and secretion of lutein in Caco-2 cells by 10.0- and 50.5-fold, respectively, compared to micellized lutein. In conclusion, delivery of lutein with polymeric NP may be an approach to improve the bioavailability of lutein in vivo. PMID:26304429

  17. Bioavailability of nanoparticulate hematite to Arabidopsis thaliana.

    Science.gov (United States)

    Marusenko, Yevgeniy; Shipp, Jessie; Hamilton, George A; Morgan, Jennifer L L; Keebaugh, Michael; Hill, Hansina; Dutta, Arnab; Zhuo, Xiaoding; Upadhyay, Nabin; Hutchings, James; Herckes, Pierre; Anbar, Ariel D; Shock, Everett; Hartnett, Hilairy E

    2013-03-01

    The environmental effects and bioavailability of nanoparticulate iron (Fe) to plants are currently unknown. Here, plant bioavailability of synthesized hematite Fe nanoparticles was evaluated using Arabidopsis thaliana (A. thaliana) as a model. Over 56-days of growing wild-type A. thaliana, the nanoparticle-Fe and no-Fe treatments had lower plant biomass, lower chlorophyll concentrations, and lower internal Fe concentrations than the Fe-treatment. Results for the no-Fe and nanoparticle-Fe treatments were consistently similar throughout the experiment. These results suggest that nanoparticles (mean diameter 40.9 nm, range 22.3-67.0 nm) were not taken up and therefore not bioavailable to A. thaliana. Over 14-days growing wild-type and transgenic (Type I/II proton pump overexpression) A. thaliana, the Type I plant grew more than the wild-type in the nanoparticle-Fe treatment, suggesting Type I plants cope better with Fe limitation; however, the nanoparticle-Fe and no-Fe treatments had similar growth for all plant types. PMID:23262070

  18. Relative bioavailability of three cefixime formulations.

    Science.gov (United States)

    Kees, F; Naber, K G; Sigl, G; Ungethüm, W; Grobecker, H

    1990-03-01

    Three galenic formulations of cefixime (tablet, syrup and dry suspension) containing 200 mg each were compared with respect to their relative bioavailability in twelve healthy volunteers. All three formulations showed reliable absorption. Mean peak plasma concentrations were reached after 3.3-3.5 h, mean terminal half lives were 2.9-3.1 h. 18-24% of the dose administered were recovered unchanged in the urine. Best bioavailability was obtained with the dry suspension (AUC0-infinity = 25.8 +/- 7.0 micrograms/ml h; Cmax = 3.4 +/- 0.9 microgram/ml), followed by the tablet (AUC0-infinity = 20.9 +/- 8.1 micrograms/ml h; Cmax = 3.0 +/- 1.0 micrograms/ml) and the syrup which is based on triglycerides (AUC0-infinity = 17.8 +/- 5.9 micrograms/ml h; Cmax = 2.4 +/- 0.7 micrograms/ml). The statistical analysis resulted in bioinequivalence between dry suspension and syrup. It is concluded that best bioavailability of cefixime after oral administration is guaranteed when taken in an "aqueous medium" either as dry suspension or as tablet with "plenty of liquid". PMID:2346538

  19. Rapid screening assay for calcium bioavailability studies

    International Nuclear Information System (INIS)

    Calcium bioavailability has been studied by numerous techniques. The authors report here the use of the gamma emitting isotope of calcium (47Ca) in a whole body retention assay system. In this system, calcium sources are administered by oral gavage and subsequent counts are determined and corrected for isotopic decay. Unlike iron and zinc retention curves, which exhibit a 2-3 day equilibration period, calcium reaches equilibration after 24 hours. Autoradiographic analysis of the femurs indicate that the newly absorbed calcium is rapidly distributed to the skeletal system. Moreover, the isotope is distributed along the entire bone. Comparisons of calcium bioavailability were made using intrinsic/extrinsic labeled milk from two species i.e. rat and goat as well as CaCO3. In addition, extrinsic labeled cow milk was examined. In the rat, the extrinsic labeled calcium from milk was better absorbed than the intrinsic calcium. This was not the case in goat milk or the calcium carbonate which exhibited no significant differences. Chromatographic analysis of the labeled milk indicates a difference in distribution of the 47Ca. From these data, the authors recommend the use of this assay system in calcium bioavailability studies. The labeling studies and comparisons indicate caution should be used, however, in labeling techniques and species milk comparison

  20. Regulation of hepatic carbohydrate metabolism by Selenium during diabetes.

    Science.gov (United States)

    Chen, Hongping; Qiu, Qinqin; Zou, Caiyan; Dou, Lianjun; Liang, Jun

    2015-05-01

    In the present study, we have tried to unravel the role of Selenium supplementation in containing hyperglycemia by regulating enzymes activities involved in carbohydrate metabolism in liver of diabetic animals. Male wistar rats were divided into four groups: normal control, diabetic, Selenium treated control and Selenium treated diabetic group. Diabetes was induced in the animals by injecting alloxan intraperitoneally at a dose level of 150 mg/kg body weight. Selenium in the form of sodium selenite was supplemented to rats at a dose level of 1 PPM in drinking water, ad libitum for two time durations of 2 and 4 weeks. Animals were sacrificed and livers were excised for the analyses of enzymes involved in carbohydrate metabolism as well as the levels of glycogen. In-vitro (14)C-d glucose uptake and its turnover were also assessed in liver slices of all the treatment groups using radiorespirometry. Selenium supplementation to the diabetic rats normalized the enzyme activities of glucose-6-phosphatase, lactate dehydrogenase and glycogen phosphorylase as well as restored the glycogen levels to within the normal limits which were altered during diabetes. Interestingly, when Selenium was supplemented to diabetic rats, (14)C-d glucose uptake and its turnover showed a statistically significant increase in their values which however, were decreased in diabetic rats. In conclusion, Selenium mediates insulin-like role during diabetes by tending to normalize the altered activities of glucose metabolizing enzymes and also improves the glucose uptake and its metabolism by the liver. PMID:25779343

  1. COMPARISON OF DETERMINING METHODS REGARDING SELENIUM CONTENT IN WHEAT PLANT

    Directory of Open Access Journals (Sweden)

    Mihaela Monica Stanciu-Burileanu

    2010-01-01

    Full Text Available As a metallic chemical element, selenium has received special attention from biologists because of its dual role as a trace element essential and toxic. The important part of enzymes that protect cells against the effects of free radicals that are produced during normal metabolism of oxygen. Also, selenium is essential for normal immune system and thyroid gland, The concentration of selenium in the soil, which varies by region, determines the default concentration of selenium in plants growing in the soil.The purpose of this paper is to present methods of comparison, dry oxidation at 450ºC and wet digestion – digestion with acids in high concentrations at microwave system digestion, for determining selenium content from wheat samples collected from the south-eastern part of Romania, namely Bărăgan Plain and Central-South Dobrogea. Selenium separation and dosage from obtained extracts carry out through a selective hydride generation atomic absorption spectrophotometry. With the software SURFER, a tendency map of selenium distribution was drawn.

  2. Genome-Wide Association Study of Serum Selenium Concentrations

    Directory of Open Access Journals (Sweden)

    Ulrike Peters

    2013-05-01

    Full Text Available Selenium is an essential trace element and circulating selenium concentrations have been associated with a wide range of diseases. Candidate gene studies suggest that circulating selenium concentrations may be impacted by genetic variation; however, no study has comprehensively investigated this hypothesis. Therefore, we conducted a two-stage genome-wide association study to identify genetic variants associated with serum selenium concentrations in 1203 European descents from two cohorts: the Prostate, Lung, Colorectal, and Ovarian (PLCO Cancer Screening and the Women’s Health Initiative (WHI. We tested association between 2,474,333 single nucleotide polymorphisms (SNPs and serum selenium concentrations using linear regression models. In the first stage (PLCO 41 SNPs clustered in 15 regions had p < 1 × 10−5. None of these 41 SNPs reached the significant threshold (p = 0.05/15 regions = 0.003 in the second stage (WHI. Three SNPs had p < 0.05 in the second stage (rs1395479 and rs1506807 in 4q34.3/AGA-NEIL3; and rs891684 in 17q24.3/SLC39A11 and had p between 2.62 × 10−7 and 4.04 × 10−7 in the combined analysis (PLCO + WHI. Additional studies are needed to replicate these findings. Identification of genetic variation that impacts selenium concentrations may contribute to a better understanding of which genes regulate circulating selenium concentrations.

  3. Selenium Nanoparticles for Stress-Resilient Fish and Livestock

    Science.gov (United States)

    Sarkar, Biplab; Bhattacharjee, Surajit; Daware, Akshay; Tribedi, Prosun; Krishnani, K. K.; Minhas, P. S.

    2015-09-01

    The fisheries and livestock sectors capture the highest share of protein-rich animal food and demonstrate accelerated growth as an agriculture subsidiary. Environmental pollution, climate change, as well as pathogenic invasions exert increasing stress impacts that lead the productivity momentum at a crossroads. Oxidative stress is the most common form of stress phenomenon responsible for the retardation of productivity in fisheries and livestock. Essential micronutrients play a determinant role in combating oxidative stress. Selenium, one of the essential micronutrients, appears as a potent antioxidant with reduced toxicity in its nanoscale form. In the present review, different methods of synthesis and characterization of nanoscale selenium have been discussed. The functional characterization of nano-selenium in terms of its effect on growth patterns, feed digestibility, and reproductive system has been discussed to elucidate the mechanism of action. Moreover, its anti-carcinogenic and antioxidant potentiality, antimicrobial and immunomodulatory efficacy, and fatty acid reduction in liver have been deciphered as the new phenomena of nano-selenium application. Biologically synthesized nano-selenium raises hope for pharmacologically enriched, naturally stable nanoscale selenium with high ecological viability. Hence, nano-selenium can be administered with commercial feeds for improvising stress resilience and productivity of fish and livestock.

  4. Serum Selenium and Ceruloplasmin in Nigerians with Peripartum Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Kamilu M. Karaye

    2015-04-01

    Full Text Available The study aimed to determine if selenium deficiency, serum ceruloplasmin and traditional birth practices are risk factors for peripartum cardiomyopathy (PPCM, in Kano, Nigeria. This is a case-control study carried out in three hospitals, and PPCM patients were followed up for six months. Critically low serum selenium concentration was defined as <70 µg/L. A total of 39 PPCM patients and 50 controls were consecutively recruited after satisfying the inclusion criteria. Mean serum selenium in patients (61.7 ± 14.9 µg/L was significantly lower than in controls (118.4 ± 45.6 µg/L (p < 0.001. The prevalence of serum selenium <70 µg/L was significantly higher among patients (76.9% than controls (22.0% (p < 0.001. The mean ceruloplasmin and prevalence of socio-economic indices, multiparity, pregnancy-induced hypertension, obesity and twin pregnancy were not different between the groups (p > 0.05. Logistic regression showed that rural residency significantly increased the odds for serum selenium <70 µg/L by 2.773-fold (p = 0.037. Baseline serum levels of selenium and ceruloplasmin were not associated with six-month mortality. This study has shown that selenium deficiency is a risk factor for PPCM in Kano, Nigeria, and is related to rural residency. However, serum ceruloplasmin, customary birth practices and some other characteristics were not associated with PPCM in the study area.

  5. Selenoprotein P. A selenium-rich extracellular glycoprotein.

    Science.gov (United States)

    Burk, R F; Hill, K E

    1994-10-01

    Selenoprotein P is a glycoprotein that has been purified from rat and human plasma. In selenium-replete rats it contains 65% of the plasma selenium and its concentration is 25-30 mg protein/L. In selenium-deficient rats its concentration is life of 75Se in selenoprotein P is 3 to 4 h, indicating a rapid turnover. Purified rat selenoprotein P contains 7.5 +/- 1 selenium atoms per molecule as selenocysteine. The sequence of the cloned cDNA predicts 10 selenocysteine residues, which suggests that the protein in plasma is a modification of the predicted one. Deduced amino acid sequence identity between rats and humans is 72%. The 3' untranslated region of selenoprotein P cDNA contains two predicted stem loops of the type essential for selenocysteine incorporation. Northern analysis indicates that selenoprotein P is expressed by many tissues. Hepatic selenoprotein P mRNA level, but not its transcription, decreases during selenium deficiency. The decrease is less than the decrease of glutathione peroxidase mRNA, however. Selenoprotein P is postulated to serve as an extracellular oxidant defense because its presence correlates with selenium protection of selenium-deficient rats against diquat-induced lipid peroxidation and liver necrosis. More research will be required to test this hypothesis and to establish the biochemical function of selenoprotein P. PMID:7931697

  6. Selenium toxicosis in wild aquatic birds

    Energy Technology Data Exchange (ETDEWEB)

    Ohlendorf, H.M.; Kilness, A.W.; Simmons, J.L.; Stroud, R.K.; Hoffman, D.J.; Moore, J.F.

    1988-01-01

    Severe gross and microscopic lesions and other changes were found in adult aquatic birds and in embryos from Kesterson Reservoir (a portion of Kesterson National Wildlife Refuge), Merced County, Calif., during 1984. Adult birds from that area were emaciated, had subacute to extensive chronic hepatic lesions, and had excess fluid and fibrin in the peritoneal cavity. Biochemical changes in their livers included elevated glycogen and non-protein-bound sulfhydryl concentrations and glutathione peroxidase activity but lowered protein, total sulfhydryl, and protein-bound sulfhydryl concentrations. Congenital malformations observed grossly in embryos were often multiple and included anophthalmia, microphthalmia, abnormal beaks, amelia, micromelia, ectrodactyly, and hydrocephaly. Mean concentrations of selenium in livers (94.4 ppm, dry weight) and kidneys (96.6 ppm) of birds collected at the Kesterson ponds were about 10 times those found at a nearby control area (8.3 and 12.2 ppm). We conclude that selenium present in the agricultural drainage water supplied to the Kesterson ponds accumulated in the food chain of aquatic birds to toxic concentrations and caused the lesion and other changes observed.

  7. Selenium and tellurium as carbon substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Jr., F. F.

    1980-01-01

    This review has summarized structure-activity studies with /sup 75/Se- and /sup 123m/Te-labeled radiopharmaceuticals in which the selenium or tellurium heteroatom has been inserted between carbon-carbon bonds. The agents that have been investigated in most detail include steroids for adrenal imaging and long-chain fatty acids, and a variety of other unique agents have also been studied. Because of the great versatility of the organic chemistry of selenium and tellurium, there is continuing interest in the preparation of radiopharmaceuticals labeled with /sup 75/Se, /sup 73/Se, and /sup 123m/Te. There are two important factors which will determine the extent of future interest in such agents. These include the necessity of a decrease in the cost of highly enriched /sup 122/Te to make the reactor production of /sup 123m/Te cost effective. In addition, the potential preparation of large amounts of /sup 73/Se should stimulate the development of /sup 73/Se-labeled radiopharmaceuticals.

  8. Bacterial respiration of arsenic and selenium

    Science.gov (United States)

    Stolz, J.F.; Oremland, R.S.

    1999-01-01

    Oxyanions of arsenic and selenium can be used in microbial anaerobic respiration as terminal electron acceptors. The detection of arsenate and selenate respiring bacteria in numerous pristine and contaminated environments and their rapid appearance in enrichment culture suggest that they are widespread and metabolically active in nature. Although the bacterial species that have been isolated and characterized are still few in number, they are scattered throughout the bacterial domain and include Gram- positive bacteria, beta, gamma and epsilon Proteobacteria and the sole member of a deeply branching lineage of the bacteria, Chrysiogenes arsenatus. The oxidation of a number of organic substrates (i.e. acetate, lactate, pyruvate, glycerol, ethanol) or hydrogen can be coupled to the reduction of arsenate and selenate, but the actual donor used varies from species to species. Both periplasmic and membrane-associated arsenate and selenate reductases have been characterized. Although the number of subunits and molecular masses differs, they all contain molybdenum. The extent of the environmental impact on the transformation and mobilization of arsenic and selenium by microbial dissimilatory processes is only now being fully appreciated.

  9. Selenium for the Prevention of Cutaneous Melanoma

    Directory of Open Access Journals (Sweden)

    Douglas Grossman

    2013-03-01

    Full Text Available The role of selenium (Se supplementation in cancer prevention is controversial; effects often depend on the nutritional status of the subject and on the chemical form in which Se is provided. We used a combination of in vitro and in vivo models to study two unique therapeutic windows for intervention in the process of cutaneous melanomagenisis, and to examine the utility of two different chemical forms of Se for prevention and treatment of melanoma. We studied the effects of Se in vitro on UV-induced oxidative stress in melanocytes, and on apoptosis and cell cycle progression in melanoma cells. In vivo, we used the HGF transgenic mouse model of UV-induced melanoma to demonstrate that topical treatment with l-selenomethionine results in a significant delay in the time required for UV-induced melanoma development, but also increases the rate of growth of those tumors once they appear. In a second mouse model, we found that oral administration of high dose methylseleninic acid significantly decreases the size of human melanoma xenografts. Our findings suggest that modestly elevation of selenium levels in the skin might risk acceleration of growth of incipient tumors. Additionally, certain Se compounds administered at very high doses could have utility for the treatment of fully-malignant tumors or prevention of recurrence.

  10. Biofortification and phytoremediation of selenium in China

    Directory of Open Access Journals (Sweden)

    Zhilin eWu

    2015-03-01

    Full Text Available Selenium (Se is an essential trace element for humans and animals but at high concentrations, Se becomes toxic to organisms due to Se replacing sulfur in proteins. Selenium biofortification is an agricultural process that increases the accumulation of Se in crops, through plant breeding, genetic engineering, or use of Se fertilizers. While Se phytoremediation is a green biotechnology to clean up Se-contaminated environments, primarily through phytoextraction and phytovolatilization. By integrating Se phytoremediation and biofortification technologies, Se-enriched plant materials harvested from Se phytoremediation can be used as Se-enriched green manures or other supplementary sources of Se for producing Se-biofortified agricultural products. Earlier studies primarily aimed at enhancing efficacy of phytoremediation and biofortification of Se based on natural variation in progenitor or identification of unique plant species. In this review, we discuss promising approaches to improve biofortification and phytoremediation of Se using knowledge acquired from model crops. We also explored the feasibility of applying biotechnologies such as inoculation of microbial strains for improving the efficiency of biofortification and phytoremediation of Se. The key research and practical challenges that remain in improving biofortification and phytoremediation of Se have been highlighted, and the future development and uses of Se-biofortified agricultural products in China has also been discussed.

  11. Selenium and tellurium as carbon substitutes

    International Nuclear Information System (INIS)

    This review has summarized structure-activity studies with 75Se- and /sup 123m/Te-labeled radiopharmaceuticals in which the selenium or tellurium heteroatom has been inserted between carbon-carbon bonds. The agents that have been investigated in most detail include steroids for adrenal imaging and long-chain fatty acids, and a variety of other unique agents have also been studied. Because of the great versatility of the organic chemistry of selenium and tellurium, there is continuing interest in the preparation of radiopharmaceuticals labeled with 75Se, 73Se, and /sup 123m/Te. There are two important factors which will determine the extent of future interest in such agents. These include the necessity of a decrease in the cost of highly enriched 122Te to make the reactor production of /sup 123m/Te cost effective. In addition, the potential preparation of large amounts of 73Se should stimulate the development of 73Se-labeled radiopharmaceuticals

  12. [Selenium in selected species of mushrooms from Poland].

    Science.gov (United States)

    Falandysz, Jerzy

    2003-01-01

    The selenium was quantified in the caps, stalks or a whole fruiting bodies of king bolete (Boletus edulis), brown birch scaber stalk (Leccinum scabrum), parasol mushroom (Macrolepiota procera), fly agaric (Amanita muscaria) and poison pax (Paxillus involutus) collected at the various regions of Poland in 1998-2001. King bolete, parasol mushroom and fly agaric were a much more abundant in selenium than brown birch scaber stalk or poison pax. Some differences were observed between the selenium content of the particular species collected at different sites as well as depending on anatomical part of the fruiting body. PMID:14755851

  13. Microgravimetric Studies of Selenium Electrodeposition Onto Different Substrates

    Directory of Open Access Journals (Sweden)

    Kowalik R.

    2014-10-01

    Full Text Available The mechanism of selenium electrodeposition from sulfuric acid solution on different substrates was studied with the electrochemical techniques. The cyclic voltammetry was combined with the quartz crystal microbalance technique to analyze selenium deposition process. The electrochemical reduction of selenous acid on gold, silver and copper electrodes was investigated. It was found that reduction of selenous acid is a very complex process and it strongly depends from the applied substrate. The voltammetric measurements indicate the range of potentials in which the process of reduction of selenous acids on the applied substrate is possible. Additionally, the microgravimetric data confirm the deposition of selenium and they reveal the mechanism of the deposition process.

  14. An Introduction to Testing Web Applications with twill and Selenium

    CERN Document Server

    Brown, Titus; Huggins, Jason

    2007-01-01

    This Short Cut is an introduction tobuilding automated web tests using twotools, twill and Selenium. twill is a simpleweb scripting language that can be usedto automate web tests, while Selenium isa web testing framework that runs in anybrowser and can be used to test complexweb sites that make extensive use ofJavaScript. The best way to use this Short Cut is torun through the examples. We expectthat within an hour you can start writingyour own functional tests in either twillor Selenium, and within a day you willunderstand most, if not all, of the possibilitiesand the limitations of these t

  15. Bioavailability of the sodium pertechnetate and morphometry of organs isolated from rats: study of possible pharmacokinetic interactions of a ginkgo biloba extract

    International Nuclear Information System (INIS)

    Many compounds affect the bioavailability of radiobiocomplexes as radiopharmaceuticals. Ginkgo Biloba extract (EGb) has several effects. The influence of an EGb on the bioavailability of the radiobiocomplex sodium pertechnetate (Na99m TcO4) and on the morphometry of the organs was evaluated. Rats were treated with EGb and Na99m TcO4 was injected. The animals were sacrificed; the radioactivity in the organs was counted. The results showed that EGb altered the Na99m TcO4 bioavailability in the kidneys, liver and duodenum. Morphometric analysis of the organs showed significant alterations (P99m TcO4. (author)

  16. Identification of a Novel Selenium-containing Compound, Selenoneine, as the Predominant Chemical Form of Organic Selenium in the Blood of Bluefin Tuna*

    OpenAIRE

    Yamashita

    2010-01-01

    A novel selenium-containing compound having a selenium atom in the imidazole ring, 2-selenyl-Nα,Nα,Nα-trimethyl-l-histidine, 3-(2-hydroseleno-1H-imidazol-5-yl)-2-(trimethylammonio)propanoate, was identified from the blood and other tissues of the bluefin tuna, Thunnus orientalis. The selenium-containing compound was purified from the tuna blood ...

  17. 75Selenium-labeled sheep plasma: the time course of changes in 75selenium distribution

    International Nuclear Information System (INIS)

    Sheep fed rations containing 0.1 ppm selenium were labeled by intravenous injection of radioactive sodium selenite or selenocystine. Gel filtration of serially collected plasma samples indicated that, with time, there was a transition from mercaptan sensitive to high mol wt mercaptan and protein solubilizer resistant selenoproteins. Radiolabeled plasma samples collected from selenite and selenocystine labeled sheep were dialyzed against buffer containing 2-mercaptoethanol or protein solubilizer. No difference in the stability between selenite- and selenocystine-labeled plasma could be detected

  18. The selenium content of SEPP1 versus selenium requirements in vertebrates

    OpenAIRE

    Penglase, Samuel; Hamre, Kristin; Ellingsen, Ståle

    2015-01-01

    Selenoprotein P (SEPP1) distributes selenium (Se) throughout the body via the circulatory system. For vertebrates, the Se content of SEPP1 varies from 7 to 18 Se atoms depending on the species, but the reason for this variation remains unclear. Herein we provide evidence that vertebrate SEPP1 Sec content correlates positively with Se requirements. As the Se content of full length SEPP1 is genetically determined, this presents a unique case where a nutrient requirement can be predicted based o...

  19. MOBILITY AND BIOAVAILABILITY OF HEAVY METALS AND METALLOIDS IN SOIL ENVIRONMENTS

    OpenAIRE

    A Violante; Cozzolino, V; L Perelomov; A.G Caporale; M Pigna

    2010-01-01

    In soil environments, sorption/desorption reactions as well as chemical complexation with inorganic and organic ligands and redox reactions, both biotic and abiotic, are of great importance in controlling their bioavailability, leaching and toxicity. These reactions are affected by many factors such as pH, nature of the sorbents, presence and concentration of organic and inorganic ligands, including humic and fulvic acid, root exudates, microbial metabolites and nutrients. In this review, we ...

  20. Selenium and nutrition. The accuracy and variability of the selenium content in commercial supplements

    International Nuclear Information System (INIS)

    Selenium is a required trace-element that has been found to be protective against serious chronic diseases such as cancer and cardiovascular disease in some, but not all, epidemiological studies using both case-control and intervention designs. As a result, the fraction of the adult U.S. population now taking a daily selenium supplement is steadily increasing. 10 or more replicate Se supplement tablets were analyzed, from each of 15 different products representing 12 different brand names with most being sampled at two different times separated by approximately 30 months. Two chemical forms, seleno-yeast and selenate were tested in 50, 100 and 200 μg/tablet dosages (seleno-yeast) and 25 and 200 μg/tablet dosages (selenate). Variations in contemporary lots were evaluated at both sampling periods. The Se content provided on the product label is generally understated. One tablet contained 2.5 times more selenium than the stated dose. Selenate supplements are less accurately labeled and more highly variable compared to yeast supplements. One popular multivitamin, labeled at 200 μg/tablet, contained tablets in excess of 300 μg. Many subjects using this supplement will exceed the 400 μg/day tolerable upper limit of intake, recently established, for Se by the Institute of Medicine's Food and Nutrition Board. (author)

  1. Selenium and selenium-sulfur cathode materials for high-energy rechargeable magnesium batteries

    Science.gov (United States)

    Zhao-Karger, Zhirong; Lin, Xiu-Mei; Bonatto Minella, Christian; Wang, Di; Diemant, Thomas; Behm, R. Jürgen; Fichtner, Maximilian

    2016-08-01

    Magnesium (Mg) is an attractive metallic anode material for next-generation batteries owing to its inherent dendrite-free electrodeposition, high capacity and low cost. Here we report a new class of Mg batteries based on both elemental selenium (Se) and selenium-sulfur solid solution (SeS2) cathode materials. Elemental Se confined into a mesoporous carbon was used as a cathode material. Coupling the Se cathode with a metallic Mg anode in a non-nucleophilic electrolyte, the Se cathode delivered a high initial volumetric discharge capacity of 1689 mA h cm-3 and a reversible capacity of 480 mA h cm-3 was retained after 50 cycles at a high current density of 2 C. The mechanistic insights into the electrochemical conversion in Mg-Se batteries were investigated by microscopic and spectroscopic methods. The structural transformation of cyclic Se8 into chainlike Sen upon battery cycling was revealed by ex-situ Raman spectroscopy. In addition, the promising battery performance with a SeS2 cathode envisages the perspective of a series of SeSn cathode materials combining the benefits of both selenium and sulfur for high energy Mg batteries.

  2. Bioavailability of fatty acids from krill oil, krill meal and fish oil in healthy subjects--a randomized, single-dose, cross-over trial

    OpenAIRE

    Köhler, Anton; Sarkkinen, Essi; Tapola, Niina; Niskanen, Tarja; Bruheim, Inge

    2015-01-01

    Background Krill contains two marine omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), mainly bound in phospholipids. Typical products from krill are krill oil and krill meal. Fish oils contain EPA and DHA predominantly bound in triglycerides. The difference in the chemical binding of EPA and DHA has been suggested to affect their bioavailability, but little is known on bioavailability of EPA and DHA in krill meal. This study was undertaken to co...

  3. Selenium content of milk and milk products of Turkey. II.

    Science.gov (United States)

    Yanardağ, R; Orak, H

    1999-04-01

    Selenium content of 1028 milk and milk products of Turkey are presented in this study. The selenium content of human milk (colostrum, transitional, and mature milk), various kinds of milk [cow, sheep, goat, buffalo, paper boxes (3%, 1.5%, 0.012% fat), bottled milk, condensed milk (10% fat), mineral added milk (1.6%), and banana, strawberry, and chocolate milk] and milk products (kefir, yogurt, Ayran, various cheese, coffee cream, ice cream, butter, margarine, milk powder, and fruit yogurt) in Turkey were determined by a spectrofluorometric method. The selenium levels of cow milks collected from 57 cities in Turkey were also determined. Selenium levels in cow milk varied with geographical location in Turkey and were found to be lowest for Van and highest for Aksaray. The results [milk (cow, sheep, goat, buffalo and human) and milks products] were compared with literature data from different countries. PMID:10208658

  4. Selenium-Mediated Synthesis of Tetrasubstituted Naphthalenes through Rearrangement

    OpenAIRE

    James Tancock; Thomas Wirth

    2015-01-01

    New β-keto ester substituted stilbene derivatives have been synthesized and cyclized with selenium electrophiles in the presence of Lewis acids. This now allows access to 1,2,3,4-tetrasubstituted naphthalene derivatives as cyclization and rearrangement products.

  5. Union Slough National Wildlife Refuge, Iowa: Avian selenium study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 2006 and 2007, we tested selenium concentrations in the eggs and nestling carcasses of tree swallows attracted to artificial nest boxes installed around Union...

  6. Investigation of the selenium metabolism in cancer cell lines

    DEFF Research Database (Denmark)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan; Andresen, Lars; Skov, Søren; Gammelgaard, Bente

    2011-01-01

    The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line...... incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size...... exclusion chromatography and ICP-MS detection. The selenium compounds exhibited large differences in their ability to induce cell death in the three cell lines and the susceptibilities of the cell lines were different. Full recovery of selenium in the cellular fractions was observed for all Se compounds...

  7. Selenium- or tellurium- containing bile acids and derivatives thereof

    International Nuclear Information System (INIS)

    This invention relates to the preparation of selenium and tellurium derivatives, particularly γ-emitting radioactive derivatives of bile acids and bile salts. Such compounds are valuable in the examination of body function, especially small bowel function. (author)

  8. Selenium in aquatic habitats at Imperial National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — During 1991 and 1992, selenium levels were studied in aquatic communities at Imperial National Wildlife Refuge on the lower Colorado River. Composite samples of...

  9. Selenium derivatives of thyroxine and tri-iodothyronine

    International Nuclear Information System (INIS)

    Novel selenium derivatives of thyroxine and tri-iodothyronine are described. They preferably contain at least one 75Se atom. The compounds are useful in dual isotope assays of thyroid function. (U.K.)

  10. Bioavailability of Micronutrients from Plant Foods: An Update.

    Science.gov (United States)

    Platel, Kalpana; Srinivasan, Krishnapura

    2016-07-26

    Deficiencies of iron, zinc, iodine and vitamin A are widespread in the developing countries, poor bioavailability of these micronutrients from plant-based foods being the major reason for their wide prevalence. Diets predominantly vegetarian are composed of components that enhance as well as inhibit mineral bioavailability, the latter being predominant. However, prudent cooking practices and use of ideal combinations of food components can significantly improve micronutrient bioavailability. Household processing such as heat treatment, sprouting, fermentation and malting have been evidenced to enhance the bioavailability of iron and β-carotene from plant foods. Food acidulants amchur and lime are also shown to enhance the bioavailability of not only iron and zinc, but also of β-carotene. Recently indentified newer enhancers of micronutrient bioaccessibility include sulphur compound-rich Allium spices-onion and garlic, which also possess antioxidant properties, β-carotene-rich vegetables-carrot and amaranth, and pungent spices-pepper (both red and black) as well as ginger. Information on the beneficial effect of these dietary compounds on micronutrient bioaccessibility is novel. These food components evidenced to improve the bioavailability of micronutrients are common ingredients of Indian culinary, and probably of other tropical countries. Fruits such as mango and papaya, when consumed in combination with milk, provide significantly higher amounts of bioavailable β-carotene. Awareness of the beneficial influence of these common dietary ingredients on the bioavailability of micronutrients would help in devising dietary strategies to improve the bioavailability of these vital nutrients. PMID:25748063

  11. Selenium and lung cancer: a systematic review and meta analysis.

    Directory of Open Access Journals (Sweden)

    Heidi Fritz

    Full Text Available BACKGROUND: Selenium is a natural health product widely used in the treatment and prevention of lung cancers, but large chemoprevention trials have yielded conflicting results. We conducted a systematic review of selenium for lung cancers, and assessed potential interactions with conventional therapies. METHODS AND FINDINGS: Two independent reviewers searched six databases from inception to March 2009 for evidence pertaining to the safety and efficacy of selenium for lung cancers. Pubmed and EMBASE were searched to October 2009 for evidence on interactions with chemo- or radiation-therapy. In the efficacy analysis there were nine reports of five RCTs and two biomarker-based studies, 29 reports of 26 observational studies, and 41 preclinical studies. Fifteen human studies, one case report, and 36 preclinical studies were included in the interactions analysis. Based on available evidence, there appears to be a different chemopreventive effect dependent on baseline selenium status, such that selenium supplementation may reduce risk of lung cancers in populations with lower baseline selenium status (serum<106 ng/mL, but increase risk of lung cancers in those with higher selenium (≥ 121.6 ng/mL. Pooling data from two trials yielded no impact to odds of lung cancer, OR 0.93 (95% confidence interval 0.61-1.43; other cancers that were the primary endpoints of these trials, OR 1.51 (95%CI 0.70-3.24; and all-cause-death, OR 0.93 (95%CI 0.79-1.10. In the treatment of lung cancers, selenium may reduce cisplatin-induced nephrotoxicity and side effects associated with radiation therapy. CONCLUSIONS: Selenium may be effective for lung cancer prevention among individuals with lower selenium status, but at present should not be used as a general strategy for lung cancer prevention. Although promising, more evidence on the ability of selenium to reduce cisplatin and radiation therapy toxicity is required to ensure that therapeutic efficacy is maintained before

  12. A reexamination of krill oil bioavailability studies.

    Science.gov (United States)

    Salem, Norman; Kuratko, Connye N

    2014-01-01

    It has proven difficult to compare the bioavailability of krill oil (KO) vs. fish oil (FO) due to several of the characteristics of KO. These include the lower concentration of the active ingredients, eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n3), in KO as well as differences in their ratio relative to FO as well as the red color due to astaxanthin. In addition, the lipid classes in which EPA and DHA are found are quite different with KO containing phospholipid, di- and tri-glycerides as well as non-esterified fatty acid forms and with FO being primarily triglycerides. No human study has yet been performed that matches the dose of EPA and DHA in a randomized, controlled trial with measures of bloodstream EPA and DHA content. However, several claims have been made suggesting greater bioavailability of KO vs. FO. These have largely been based on a statistical argument where a somewhat lower dose of KO has been used to result in a similar bloodstream level of EPA and/or DHA or their total. However, the magnitude of the dosage differential is shown to be too small to be expected to result in differing blood levels of the long chain n-3 PUFAs. Some studies which have claimed to provide equal doses of KO and FO have actually used differing amounts of the two major n-3 fatty acid constituents. It is concluded that there is at present no evidence for greater bioavailability of KO vs. FO and that more carefully controlled human trials must be performed to establish their relative efficacies after chronic administration. PMID:25156381

  13. Web自动化测试工具SELENIUM

    Institute of Scientific and Technical Information of China (English)

    张德申; 秦红亮

    2013-01-01

    本文主要介绍了网页测试工具SELENIUM的配置、选择及使用。结合一个测试案例,介绍了在C#中如何使用SELENIUM,在PHP中如何使用SELENIUM,并列举了相应代码。最后对SELENIUM的应用范围进行了总结。

  14. Benchmarking configurations for web-testing:Selenium versus Watir

    OpenAIRE

    Kuutila, M. (Miikka)

    2016-01-01

    Benefits of testing automation according to current literature are reusability, repeatability and effort saved in test execution, while some of the current difficulties lie in maintainability, initial investment and test case creation. This thesis presents a brief literature review on the state of testing automation and a larger literature review on the use of Selenium and Watir in web context. Literature review on the use of Selenium and Watir contains an introduction to the history and u...

  15. Simulation of Selenium Remobolisation and cycling in sediment

    OpenAIRE

    Palm, Erik

    1997-01-01

    Lake Macquarie is the largest estuarine lake in New South Wales and is located on the eastern seaboard of Australia, approximately 85 km north of Sydney.The study of heavy metal concentrations in surficial sediments, sediment cores, seagrasses and fish conducted by the New South Wales Department of Mines in 1974 revealed that significant heavy metal contamination of Lake Macquarie has occurred. The metalloid selenium was found in elevated concentrations in 1987. Selenium has a complex chemist...

  16. Hepatoprotective effects of selenium during diabetes in rats.

    Science.gov (United States)

    Zou, C; Qiu, Q; Chen, H; Dou, L; Liang, J

    2016-02-01

    The present study investigated the hepatoprotective role of selenium during alloxan-induced diabetes in rats. Male Wistar rats were divided into four groups, namely, normal control, selenium treated, diabetic, and selenium-treated diabetic. Diabetes was induced in the animals by injecting alloxan intraperitoneally at a dose rate of 150 mg/kg body weight. Selenium in the form of sodium selenite was supplemented to rats at a dose level of 1 ppm in drinking water, ad libitum for two time durations of 2 and 4 weeks. The effects of different treatments were studied on various parameters in rat liver, which included serum glucose levels, serum insulin levels, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lipid peroxidation (LPO), glutathione reduced (GSH), oxidized glutathione (GSSG), total glutathione (TG), superoxide dismutase (SOD), catalase (CAT), glutathione reductase, glutathione peroxidase, metallothionein (MT), and histoarchitecture. A significant increase in the serum glucose levels, LPO levels, and in enzyme activities of ALP, ALT, and AST was observed in diabetic rats which, however, got decreased significantly upon supplementation with selenium. On the contrary, decreased enzyme activities of GSSG, SOD, and CAT and depressed levels of GSH as well as serum insulin levels were observed in diabetic rats which got improved following selenium supplementation. Interestingly, MT levels were increased both in diabetic and selenium-treated diabetic rats. Further, marked alterations in histoarchitecture were seen in diabetic rats with the prominent features being congestion in sinusoids, lipid accumulation, and centrilobular hepatocyte degeneration. However, selenium treatment to diabetic rats showed overall improvement in the hepatic histoarchitecture. PMID:25820154

  17. Selenium transformation in coal mine spoils: Its environmental impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Harness, J.; Atalay, A.; Koll, K.J.; Zhang, H.; Maggon, D.

    1991-12-31

    The objective of this program was to conduct an environmental impact assessment study for selenium from coal mine spoils. The use of in-situ lysimetry to predict selenium speciation, transformation, and mobility under natural conditions was evaluated. The scope of the study was to construct and test field-scale lysimeter and laboratory mini-column to assess mobility and speciation of selenium in coal mine overburden and soil systems; to conduct soil and groundwater sampling throughout the state of Oklahoma for an overall environmental impact assessment of selenium; and to conduct an in-depth literature review on the solubility, speciation, mobility, and toxicity of selenium from various sources. Groundwater and surface soil samples were also collected from each county in Oklahoma. Data collected from the lysimeter study indicated that selenium in the overburden of the abandoned mine site was mainly found in the selenite form. The amount of selenite found was too low and immobile to be of concern to the environment. The spoil had equilibrated long enough (over 50 years) that most of the soluble forms of selenium have already been lost. Examination of the overburden indicated the presence of pyrite crystals that precipitated over time. The laboratory mini-column study indicated that selenite is quite immobile and remained on the overburden material even after leaching with dilute acid. Data from groundwater samples indicated that based on the current permissible level for selenium in groundwater (0.01 mg Se/L), Oklahoma groundwater is widely contaminated with the element. However, according to the new regulation (0.05 mg Se/L), which is to be promulgated in 1992, only 9 of the 77 counties in the state exceed the limit.

  18. Selenium and Chronic Diseases: A Nutritional Genomics Perspective

    Directory of Open Access Journals (Sweden)

    Catherine Méplan

    2015-05-01

    Full Text Available Mechanistic data have revealed a key role for selenium (Se and selenoproteins in biological pathways known to be altered in multifactorial diseases, such as cellular maintenance, response to oxidative stress and correct protein folding. Although epidemiological studies indicate that low Se intake is linked to increased risk for various chronic diseases, supplementation trials have given confusing outcomes, suggesting that additional genetic factors could affect the relationship between Se and health. Genetic data support this hypothesis, as risk for several chronic diseases, in particular cancer, was linked to a number of single nucleotide polymorphisms (SNP altering Se metabolism, selenoprotein synthesis or activity. Interactions between SNPs in selenoprotein genes, SNPs in related molecular pathways and biomarkers of Se status were found to further modulate the genetic risk carried by the SNPs. Taken together, nutritional genomics approaches uncovered the potential implication of some selenoproteins as well as the influence of complex interactions between genetic variants and Se status in the aetiology of several chronic diseases. This review discusses the results from these genetic associations in the context of selenoprotein functions and epidemiological investigations and emphasises the need to assess in future studies the combined contribution of Se status, environmental stress, and multiple or individual SNPs to disease risk.

  19. Is Selenium a Potential Treatment for Cancer Metastasis?

    Directory of Open Access Journals (Sweden)

    Yu-Chi Chen

    2013-04-01

    Full Text Available Selenium (Se is an essential micronutrient that functions as a redox gatekeeper through its incorporation into proteins to alleviate oxidative stress in cells. Although the epidemiological data are somewhat controversial, the results of many studies suggest that inorganic and organic forms of Se negatively affect cancer progression, and that several selenoproteins, such as GPXs, also play important roles in tumor development. Recently, a few scientists have examined the relationship between Se and metastasis, a late event in cancer progression, and have evaluated the potential of Se as an anti-angiogenesis or anti-metastasis agent. In this review, we present the current knowledge about Se compounds and selenoproteins, and their effects on the development of metastasis, with an emphasis on cell migration, invasion, and angiogenesis. In the cancers of breast, prostate, colorectal, fibrosarcoma, melanoma, liver, lung, oral squamous cell carcinoma, and brain glioma, there is either clinical evidence linking selenoproteins, such as thioredoxin reductase-1 to lymph node metastasis; in vitro studies indicating that Se compounds and selenoproteins inhibited cell motility, migration, and invasion, and reduced angiogenic factors in some of these cancer cells; or animal studies showing that Se supplementation resulted in reduced microvessel density and metastasis. Together, these data support the notion that Se may be an anti-metastastatic element in addition to being a cancer preventative agent.

  20. A reexamination of krill oil bioavailability studies

    OpenAIRE

    Salem, Norman; Kuratko, Connye N.

    2014-01-01

    It has proven difficult to compare the bioavailability of krill oil (KO) vs. fish oil (FO) due to several of the characteristics of KO. These include the lower concentration of the active ingredients, eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n3), in KO as well as differences in their ratio relative to FO as well as the red color due to astaxanthin. In addition, the lipid classes in which EPA and DHA are found are quite different with KO containing phospholipid, ...

  1. Animal bioavailability of defined xenobiotic lignin metabolites

    International Nuclear Information System (INIS)

    Lignin has been recognized as a major component of bound pesticide residues in plants and is thought to be undigestible in animals. Two defined ring-U-14C-labeled chloroaniline/lignin metabolites have now been fed to rats, where a release of ∼66% of the bound xenobiotic occurred in the form of simple chloroaniline derivatives. The observed high degree of bioavailability indicates that bound pesticidal residues may possess ecotoxicological significance. In parallel studies, the white-rot fungus Phanerochaete chrysosporium was more efficient, and a soil system was much less efficient, in the degradation of the [ring-U-14C]chloroaniline/lignin metabolites

  2. Selenium investigations in the Elk Valley (British Columbia) and the Cheviot and Luscar coal mines (Alberta)

    International Nuclear Information System (INIS)

    This presentation reported on a study that examined the concentration of selenium (Se) in the waters of the Elk River to determine the risks to the aquatic environment. Se concentrations are increasing in water downstream of coal mines. Se concentrations in benthic invertebrates in the Elk River are high, but have not increased over the last few years. The viability and productivity of fish and water bird populations do not appear to be negatively affected. The potential Se effects to trout in Alberta are being examined further in an effort to establish a certain adverse effects threshold for trout in the Elk River Valley. Human health or terrestrial wildlife do not appear to be adversely affected. Monitoring and management is the main focus of the study. Management studies include predicting future Se releases under different mining scenarios; determining factors affecting the cycling and conversion of inorganic Se once it enters the aquatic environment; and integrating current and future information to effectively manage Se releases. Treatment alternatives such as passive bioreactor and in situ methods are also being examined. Mapping of lentic and lotic areas in the Elk River Valley will help in evaluating the regional significance of any localized aquatic impacts associated with elevated Se concentrations. New studies involving a Standard Operating Procedure for fish deformity analysis and predictive modeling of trout populations are among the recommendations that have been applied from a 2005 Selenium Science Panel.

  3. Biological effects of selenium and relationships with carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Diplock, A.T.

    1984-01-01

    Selenium is an element that is both essential, at low levels of dietary intake, and toxic, at high levels, to man and a wide range of animals. The purpose of the communication is to review the evidence for the involvement of hyper- and hypo-selenosis in the etiology of cancer. High levels of selenium intake have been blamed for an increase in cancer, dental caries and an array of other conditions. Critical evaluation of the evidence, however, leads to the conclusion that such claims have little substance. On the other hand, low levels of selenium intake may be associated with an increased incidence of certain forms of cancer and there appears to be an inverse relationship between blood selenium levels and cancer death rate in the US. Keshan Disease, in the People's Republic of China has only been shown to occur in populations severely depleted of selenium. In well nourished populations there is no evidence to indicate that selenium supplements have any prophylactic or therapeutic benefit against human diseases such as cancer, cardiovascular disease or cystic fibrosis. 33 references.

  4. Serum selenium level and risk of lung cancer mortality

    DEFF Research Database (Denmark)

    Suadicani, P; Hein, H O; Gyntelberg, F

    2011-01-01

    (chronic bronchitis and peak flow), referencing the lowest level of serum selenium HRs were 1.17(0.79-1.75), and 1.43(0.96-2.14), respectively. Among heavy smokers a high serum selenium was associated with a significantly increased risk of lung cancer mortality after taking into account all potential......Serum selenium has been implicated as a risk factor for lung cancer, but the issue remains unsettled. We tested in a cohort of 3,333 males aged 53 to 74 years the hypothesis that a low serum selenium would be associated with an increased risk of lung cancer mortality.During 16 years, 167 subjects(5......, referencing the lowest level of serum selenium hazard ratios with 95% CI (HR) for medium and high levels of serum selenium were 0.97(0.66-1.43), and 0.99(0.68-1.45), respectively. Taking into account pack years of smoking, spirits intake, dietary markers (salt and fat preferences), and health measures...

  5. Nuclear-based methods for the study of selenium

    International Nuclear Information System (INIS)

    The essentiality of selenium to the human being and in particular its deficiency state, associated with prolonged inadequate dietary intake, have received considerable attention. In addition, the possible relationship between selenium and cancer and the claim that selenium may possess cancer-prevention properties have focused research effort. It has been observed in a number of studies on laboratory animals that selenium supplementation protects the animals against carcinogen-induced neoplastic growth in various organ sites, reduces the incidence of spontaneous mammary tumors, and suppresses the growth of transplanted tumor cells. In these research programs on the relationship between trace element levels and senile dementia and depression and the elemental changes in blood associated with selenium supplementation in a normal group of volunteers, it became obvious that in addition to establishing normal levels of elements in the population of interest, there was a more fundamental requirement for methods to be developed that would allow the study of the distribution of selenium in the body and its binding sites. The authors propose emission tomography and perturbed angular correlation as techniques worth exploring

  6. Daily dietary selenium intake of selected Brazilian population groups

    International Nuclear Information System (INIS)

    Due to its essential characteristics, the daily dietary selenium intake of individuals should be monitored accurately. Daily selenium intake of different Brazilian population groups based on duplicate portion diet analysis was evaluated and compared with the new estimated average requirement values (EAR), to assess if selenium deficiency or excess could be observed in these groups. Selenium content was determined by neutron activation analysis (NAA). The average daily dietary selenium intake found was 26.3 (±8.3) μg/day for children from the city of Sao Paulo, 37.4 (±16.0) μg/day for children from Belem, 107 (±107) μg/day for children from Macapa, 28.4 (±7.5) μg/day for institutionalized elderly, 32 (±6) μg/day for non-institutionalized elderly and 37 (±17) μg/day for university students from Sao Paulo. Most daily dietary selenium intake range observed were below the EAR values. The values obtained for children groups from Belem and Macapa cities, whose intake levels were much higher than the recommendation, were an exception. (author)

  7. Selenium Cycling Across Soil-Plant-Atmosphere Interfaces: A Critical Review

    Directory of Open Access Journals (Sweden)

    Lenny H.E. Winkel

    2015-05-01

    Full Text Available Selenium (Se is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass and in the atmosphere. Low Se levels in certain terrestrial environments have resulted in Se deficiency in humans, while elevated Se levels in waters and soils can be toxic and result in the death of aquatic wildlife and other animals. Human dietary Se intake is largely governed by Se concentrations in plants, which are controlled by root uptake of Se as a function of soil Se concentrations, speciation and bioavailability. In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere. The mobilization of Se across soil-plant-atmosphere interfaces is thus of crucial importance for human Se status. This review gives an overview of current knowledge on Se cycling with a specific focus on soil-plant-atmosphere interfaces. Sources, speciation and mobility of Se in soils and plants will be discussed as well as Se hyperaccumulation by plants, biofortification and biomethylation. Future research on Se cycling in the environment is essential to minimize the adverse health effects associated with unsafe environmental Se levels.

  8. [Feed supplementation with selenium in relation to the vitamin E-selenium deficiency syndrome in pigs (author's transl)].

    Science.gov (United States)

    Pedersen, K B; Simesen, M G

    1977-01-01

    After the addition of selenium to swine feed (max. 0.1 ppm) was legalized in Denmark in 1975, a marked reduction has occurred in the incidence of hepatosis dietetica (HD) in the material received at the State Veterinary Serum Laboratory for diagnostic examination, while the incidence of mulberry heart disease (MHD) appears to be unchanged (Table I). In a material collected before the addition of selenium to swine feed was permitted, the selenium content in liver and heart was found to be significantly lower in the pigs that had died of MHD than in normal pigs, but higher than in pigs that had died of HD (Table II). These observations tend to support the view that feed supplementation with selenium is more effective to prevent HD than MHD. PMID:866121

  9. Determinants of selenium status in healthy adults

    Directory of Open Access Journals (Sweden)

    Hoeg Antonia

    2011-07-01

    Full Text Available Abstract Background Selenium (Se status in non-deficient subjects is typically assessed by the Se contents of plasma/serum. That pool comprises two functional, specific selenoprotein components and at least one non-functional, non-specific components which respond differently to changes in Se intake. A more informative means of characterizing Se status in non-deficient individuals is needed. Methods Multiple biomarkers of Se status (plasma Se, serum selenoprotein P [SEPP1], plasma glutathione peroxidase activity [GPX3], buccal cell Se, urinary Se were evaluated in relation to selenoprotein genotypes (GPX1, GPX3, SEPP1, SEP15, dietary Se intake, and parameters of single-carbon metabolism in a cohort of healthy, non-Se-deficient men (n = 106 and women (n = 155. Conclusions Plasma Se concentration was 142.0 ± 23.5 ng/ml, with GPX3 and serum-derived SEPP1 calculated to comprise 20% and 34%, respectively, of that total. The balance, comprised of non-specific components, accounted for virtually all of the interindividual variation in total plasma Se. Buccal cell Se was associated with age and plasma homocysteine (hCys, but not plasma Se. SEPP1 showed a quadratic relationship with body mass index, peaking at BMI 25-30. Urinary Se was greater in women than men, and was associated with metabolic body weight (kg0.75, plasma folate, vitamin B12 and hCys (negatively. One GPX1 genotype (679T/T was associated with significantly lower plasma Se levels than other allelic variants. Selenium intake, estimated from food frequency questionnaires, did not predict Se status as indicated by any biomarker. These results show that genotype, methyl-group status and BMI contribute to variation in Se biomarkers in Se-adequate individuals.

  10. Laser-Induced Gas-Phase Pyrolysis of Dimethyl Selenium: Chemical Deposition of Selenium and Poly(selenoformaldehyde)

    Czech Academy of Sciences Publication Activity Database

    Pokorná, Dana; Urbanová, Markéta; Bastl, Zdeněk; Šubrt, Jan; Pola, Josef

    2004-01-01

    Roč. 71, č. 2 (2004), s. 635-644. ISSN 0165-2370 R&D Projects: GA AV ČR IAA4072107; GA MŠk OC 523.60 Institutional research plan: CEZ:AV0Z4072921; CEZ:AV0Z4032918; CEZ:AV0Z4040901 Keywords : dimethyl selenium * laser pyrolysis * selenium films Subject RIV: CC - Organic Chemistry Impact factor: 1.352, year: 2004

  11. Bioavailability is improved by enzymatic modification of the citrus flavonoid hesperidin in humans: A randomized, double-blind, crossover trial

    DEFF Research Database (Denmark)

    Nielsen, I.L.F.; Chee, W.S.S.; Bredsdorff, Lea;

    2006-01-01

    study demonstrated that the bioavailability of hesperidin was modulated by enzymatic conversion to hesperetin-7-glucoside, thus changing the absorption site from the colon to the small intestine. This may affect future interventions concerning the health benefits of citrus flavonoids.......Hesperidin is the predominant polyphenol consumed from citrus fruits and juices. However, hesperidin is proposed to have limited bioavailability due to the rutinoside moiety attached to the flavonoid. The aim of this study was to demonstrate in human subjects that the removal of the rhamnose group...

  12. In vitro–in vivo studies of the quantitative effect of calcium, multivitamins and milk on single dose ciprofloxacin bioavailability

    Directory of Open Access Journals (Sweden)

    Baishakhi Dey

    2015-12-01

    Full Text Available Ciprofloxacin, commonly used in India as an anti-microbial for prolonged use in chronic and non-specific indications, may affect the bioavailability of the drug. The drug prescribed is commonly taken with multivitamins, calcium and milk. A simple and reliable analytical methodology obtaining a correlation with in vivo urinary excretion studies using UV and HPLC and in vitro dissolution studies (IVIVC has shown a significant increase in elimination rate of ciprofloxacin co-administered with multivitamins, calcium and milk. Appreciable IVIVC results proved that dissolution studies could serve as an alternative to in vivo bioavailability and also support bio-waivers.

  13. In vitro-in vivo studies of the quantitative effect of calcium, multivitamins and milk on single dose ciprofloxacin bioavailability

    Institute of Scientific and Technical Information of China (English)

    Baishakhi Dey; Prakash Katakam; Fathi H. Assaleh; Babu Rao Chandu; Shanta Kumari Adiki; Analava Mitra

    2015-01-01

    Ciprofloxacin, commonly used in India as an anti-microbial for prolonged use in chronic and non-specific indications, may affect the bioavailability of the drug. The drug prescribed is commonly taken with multivitamins, calcium and milk. A simple and reliable analytical methodology obtaining a correlation with in vivo urinary excretion studies using UV and HPLC and in vitro dissolution studies (IVIVC) has shown a significant increase in elimination rate of ciprofloxacin co-administered with multivitamins, calcium and milk. Appreciable IVIVC results proved that dissolution studies could serve as an alternative to in vivo bioavailability and also support bio-waivers.

  14. Selenium levels in patients with autoimmune thyroiditis and controls in lower Austria.

    Science.gov (United States)

    Wimmer, I; Hartmann, T; Brustbauer, R; Minear, G; Dam, K

    2014-09-01

    Autoimmune thyroiditis (AIT) is one of the most common autoimmune diseases; genetic as well as environmental factors contribute to its pathogenesis. The thyroid is the organ with the highest selenium content per unit weight. Selenium status appears to have an impact on the development of thyroid pathologies. We investigated a possible difference of selenium serum levels as a marker of nutritional selenium supply between patients with AIT in central Lower Austria and a matched group of healthy persons living in the same region. Selenium serum levels in the patients with AIT were 98.0 ± 15.6 μg/l. A significant difference to the matched group of normal persons, whose selenium serum levels were 103.2 ± 12.4 μg/l, could not be detected by the t-test (p>0.05). We considered the serum selenium levels to be indicators of selenium supply (by alimentation). A serum level of 120-160 μg/l of selenium represents the normal range. According to this, most patients and control persons showed mild to moderate selenium deficiency (80-120 μg/l selenium). Although our data present slightly higher selenium levels in normal persons than in patients with AIT, this weak and statistically insignificant trend is not sufficient to support the conclusion of a link between inadequate selenium supply and autoimmune thyroid disease. PMID:24977659

  15. Bioavailability of cadmium from linseed and cocoa

    DEFF Research Database (Denmark)

    Hansen, Max; Rasmussen, Rie Romme; Sloth, Jens Jørgen

    2014-01-01

    the food authorities in order to give correct advises to the population. The aim of this study was to investigate the bioavailability of cadmium from whole linseed, crushed linseed, cocoa and cadmium chloride in rats. An experiment where 40 rats were divided into 4 groups and a control group and dosed...... with whole linseed, crushed linseed, cocoa and CdCl2 for 3 weeks was performed. Linseed or cocoa made up 10% of the feed (by weight) and was added as a replacement for carbohydrate source. The rats were dosed for 3 weeks and the cadmium content in the rats' kidneys was measured by ICPMS as a biomarker...... which could be measured in the kidney compared to the calculated total intake was as follows: Control 2.0 %, Crushed linseed 0.9 %, whole linseed, 1.5 %, cocoa 0.7 % and CdCl2 4.6 %. Based on this study it could not be concluded that the bioavailability in rats form whole linseed is lower that for...

  16. Bioavailability of platinum emitted from automobile exhaust.

    Science.gov (United States)

    Artelt, S; Kock, H; Nachtigall, D; Heinrich, U

    1998-08-01

    A model substance was used which is similar in respect to platinum content of exhaust particles emitted from a three-way-catalytic converter equipped engine. The bioavailability of platinum from such exhaust particles and the kind of platinum species formed in vivo were assessed. An in vitro solubility test showed a solubility of approximately 10 percent of platinum content of the model substance in physiological sodium chloride solution. Two short-term animal studies (8 days) were performed. In all examined rat tissues and body fluids platinum could be detected. In addition, the contribution of the overall bioavailability caused by swallowing a certain amount of the intratracheally applied platinum was evaluated by oral application. It was very low. An analytical method was developed to determine platinum species. Synthetic samples (matrix with a platinum standard solution) were analysed. In rat bronchoalveolar lavage spiked with a platinum standard solution only low molecular complexed platinum was found whereas in rat blood plasma all platinum was bound to proteins. In ongoing studies, the model substance is being tested in a three month rat inhalation study. PMID:9820662

  17. Polymeric microcontainers improve oral bioavailability of furosemide.

    Science.gov (United States)

    Nielsen, Line Hagner; Melero, Ana; Keller, Stephan Sylvest; Jacobsen, Jette; Garrigues, Teresa; Rades, Thomas; Müllertz, Anette; Boisen, Anja

    2016-05-17

    Microcontainers with an inner diameter of 223μm are fabricated using the polymer SU-8, and evaluated in vitro, in situ and in vivo for their application as an advanced oral drug delivery system for the poorly water soluble drug furosemide. An amorphous sodium salt of furosemide (ASSF) is filled into the microcontainers followed by applying a lid using Eudragit L100. It is possible to control the drug release in vitro, and in vitro absorption studies show that the microcontainers are not a hindrance for absorption of ASSF. In situ perfusion studies in rats are performed with ASSF-filled microcontainers coated with Eudragit and compared to a furosemide solution. The absorption rate constant of ASSF confined in microcontainers is found to be significantly different from the solution, and by light microscopy, it is observed that the microcontainers are engulfed by the intestinal mucus. An oral bioavailability study in rats is performed with ASSF confined in microcontainers coated with Eudragit and a control group with ASSF in Eudragit-coated capsules. A relative bioavailability of 220% for the ASSF in microcontainers compared to ASSF in capsules is found. These studies indicate that the microcontainers could serve as a promising oral drug delivery system. PMID:27033999

  18. Improved bioavailability through floating microspheres of lovastatin

    Directory of Open Access Journals (Sweden)

    S Kumar

    2011-03-01

    Full Text Available "n Background and the purpose of the study: Lovastatin is an antihyperlipidemic agent which has low bioavailability due to the extensive first pass metabolism. It was sought to increase gastric retention of lovastatin by development of a sustained release gastroretentive drug delivery system leading to reduced fluctuation in the plasma concentration and improved bioavailability. "nMethods: Floating microspheres were prepared by emulsion solvent diffusion technique, using various polymers and their blends. The in vitro performance was evaluated for drug-polymer compatibility, percent yield, particle size, drug entrapment efficiency, in vitro onset and duration of floatation, in vitro drug release as well as in vivo determination of serum cholesterol level. "nResults: The mean particle size of microspheres was observed to be between 6.9 to 9.5 μm and the maximum particle size was around 50 μm. In vivo studies of the selected batches indicated lower level of serum cholesterol compared to the marketed tablet at the same dose but was not significant. Major conclusion: The data obtained in this study suggested that a microparticulate floating dosage form of lovastatin can be successfully designed to yield controlled delivery with improved therapeutic efficacy.

  19. Relationships between the selenium content in flue-cured tobacco leaves and the selenium content in soil in Enshi, China tobacco-growing area

    International Nuclear Information System (INIS)

    Relationships between the selenium content in flue-cured tobacco leaves and the selenium content in soil in Enshi tobacco-growing area were analyzed. The results indicated that: The selenium content in flue-cured tobacco leaves in Enshi was high, ranging from 0.30 to 29.30 mg kg/sup -1/ with the mean of (8.37+- 5.83) mg kg/sup -1/. The content of selenium in flue-cured tobacco among different positions was X2F>C3F>B2F, among different altitudes was medium altitude(800 m -- 1200 m)>high altitude(=1200 m)>low altitude (<800 m). The selenium content in soil in Enshi tobacco-growing area was high, ranging from 0.28 to 7.03 mg kg/sup -1/ with the mean of (2.56 +- 1.64) mg kg/sup -1/. Most of the soil was selenium-rich and high-selenium soil, and 34.44% of soil was excessive-selenium soil. As the soil thickness deepened, the selenium contents in soil became lower and lower, and the same trend was observed in the selenium content of flue-cured tobacco leaves at different altitudes. There was significantly positive-correlation between the selenium content in soil and the selenium content of flue-cured tobacco leaves (correlation coefficient was 0.949). Based on the correlation analysis, the regression equation, was established between soil available selenium and the selenium content in flue-cured tobacco leaves for 72 samples. Regression equation reached a significant level by F-test. (author)

  20. Bioavailability of silver and silver sulfide nanoparticles to lettuce (Lactuca sativa): Effect of agricultural amendments on plant uptake.

    Science.gov (United States)

    Doolette, Casey L; McLaughlin, Michael J; Kirby, Jason K; Navarro, Divina A

    2015-12-30

    Silver nanoparticles (AgNPs) can enter terrestrial systems as sulfidised AgNPs (Ag2S-NPs) through the application of biosolids to soil. However, the bioavailability of Ag2S-NPs in soils is unknown. The two aims of this study were to investigate (1) the bioavailability of Ag to lettuce (Lactuca sativa) using a soil amended with biosolids containing Ag2S-NPs and (2) the effect of commonly used agricultural fertilisers/amendments on the bioavailability of Ag, AgNPs and Ag2S-NPs to lettuce. The study used realistic AgNP exposure pathways and exposure concentrations. The plant uptake of Ag from biosolids-amended soil containing Ag2S-NPs was very low for all Ag treatments (0.02%). Ammonium thiosulfate and potassium chloride fertilisation significantly increased the Ag concentrations of plant roots and shoots. The extent of the effect varied depending on the type of Ag. Ag2S-NPs, the realistic form of AgNPs in soil, had the lowest bioavailability. The potential risk of AgNPs in soils is low; even in the plants that had the highest Ag concentrations (Ag(+)+thiosulfate), only 0.06% of added Ag was found in edible plant parts (shoots). Results from the study suggest that agricultural practises must be considered when carrying out risk assessments of AgNPs in terrestrial systems; such practises can affect AgNP bioavailability. PMID:26322966

  1. Bioavailability and bioaccumulation of metal-based engineered nanomaterials in aquatic environments: concepts and processes: chapter 5

    Science.gov (United States)

    Luoma, Samuel N.; Khan, Farhan R.; Croteau, Marie-Noële

    2014-01-01

    Bioavailability of Me-ENMs to aquatic organisms links their release into the environment to ecological implications. Close examination shows some important differences in the conceptual models that define bioavailability for metals and Me-ENMs. Metals are delivered to aquatic animals from Me-ENMs via water, ingestion, and incidental surface exposure. Both metal released from the Me-ENM and uptake of the nanoparticle itself contribute to bioaccumulation. Some mechanisms of toxicity and some of the metrics describing exposure may differ from metals alone. Bioavailability is driven by complex interaction of particle attributes, environmental transformations, and biological traits. Characterization of Me-ENMs is an essential part of understanding bioavailability and requires novel methodologies. The relative importance of the array of processes that could affect Me-ENM bioavailability remains poorly known, but new approaches and models are developing rapidly. Enough is known, however, to conclude that traditional approaches to exposure assessment for metals would not be adequate to assess risks from Me-ENMs.

  2. Estimating Lead (Pb) Bioavailability In A Mouse Model

    Science.gov (United States)

    Children are exposed to Pb through ingestion of Pb-contaminated soil. Soil Pb bioavailability is estimated using animal models or with chemically defined in vitro assays that measure bioaccessibility. However, bioavailability estimates in a large animal model (e.g., swine) can be...

  3. Polymer-support Selenium-induced Electrophilic Cyclization: Solid-phase Synthesis of Flavonoids

    Institute of Scientific and Technical Information of China (English)

    Jian CAO; E TANG; Xuan HUANG; Lu Ling WU; Xian HUANG

    2006-01-01

    The Lewis acid mediated polystyrene supported selenium induced intramolecular cyclization of chalcones and oxidative cleavage of selenium resins gave the corresponding flavonoids in good yields and purities have been reported.

  4. Final report on biogeochemical cycling of selenium in Benton Lake, Montana

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The biogeochemical cycling of selenium in Benton Lake National Wildlife Refuge, west-central Montana was very complicated. Selenium accumulation in sediment was a...

  5. Hazard assessment of selenium contamination at Benton Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a study done to assess selenium levels on Benton Lake NWR. Because selenium is not evenly distributed across wetland units, sampling in 2006...

  6. Update to hazard assessment of selenium contamination at Benton Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes a study done to assess selenium levels on Benton Lake NWR. Water was sampled for dissolved selenium in Lake Creek at the point where it...

  7. Update to hazard assessment of selenium contamination at Benton Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The levels of selenium in all trophic levels in Unit 1 on the refuge continue to be a concern. The mean concentration of selenium in water, sediment,...

  8. Nanomemulsion of megestrol acetate for improved oral bioavailability and reduced food effect.

    Science.gov (United States)

    Li, Yixian; Song, Chung Kil; Kim, Min-Kyoung; Lim, Hyosang; Shen, Qingbo; Lee, Don Haeng; Yang, Su-Geun

    2015-10-01

    Megestrol acetate (MGA) belongs to the BCS class II drugs with low solubility and high permeability, and its oral absorption in conventional dosage form MGA microcrystal suspension (MGA MS) is very limited and greatly affected by food. In this study, MGA nanoemulsion (MGA NE) was formulated based on solubility, phase-diagram and release studies. Then oral bioavailability of MGA NE and MGA MS was evaluated. A randomized two-way crossover trial was conducted on six male dogs under fed and fasting conditions. Blood concentrations of MGA were analyzed using LC-MS/MS. MGA NE yielded 5.00-fold higher oral bioavailability in fasting conditions and displayed more stable absorption profiles after food intake compared with MGA MS. PMID:25893430

  9. Changes in the composition and bioavailability of dissolved organic matter during sea ice formation

    DEFF Research Database (Denmark)

    Jørgensen, Linda; Stedmon, Colin A.; Kaartokallio, Hermanni;

    2015-01-01

    processes such as sea ice formation as the source of the significant DOM removal in the Arctic Ocean. We present the results of a mesocosm experiment designed to investigate how sea ice formation affects DOM composition and bioavailability. We measured the change in different fluorescent dissolved organic...... matter (FDOM) fractions in sea ice, brines (contained in small pores between the ice crystals), and the underlying seawater during a 14 d experiment. Two series of mesocosms were used: one with seawater alone and one with seawater enriched with humic-rich river water. Abiotic processes increased......The Arctic Ocean receives a large amount of terrestrial dissolved organic matter (DOM) from rivers and more than half of this is removed during its passage through the Arctic Ocean. Terrestrial DOM is generally believed to have a low bioavailability and recent studies point to physicochemical...

  10. Hydrological regime and salinity alter the bioavailability of Cu and Zn in wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Speelmans, M. [Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, J. Plateaustraat 22, B-9000 Ghent (Belgium); Lock, K., E-mail: koen.lock@UGent.b [Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, J. Plateaustraat 22, B-9000 Ghent (Belgium); Vanthuyne, D.R.J. [Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent University, Coupure Links 653, B-9000 Ghent (Belgium); Hendrickx, F. [Terrestrial Ecology Unit (TEREC), Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent (Belgium); Du Laing, G.; Tack, F.M.G. [Laboratory of Analytical Chemistry and Applied Ecochemistry, Ghent University, Coupure Links 653, B-9000 Ghent (Belgium); Janssen, C.R. [Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, J. Plateaustraat 22, B-9000 Ghent (Belgium)

    2010-05-15

    In the context of the European Water Framework Directive, controlled flooding of lowlands is considered as a potential water management strategy to minimise the risk of flooding of inhabited areas. However, due to historical pollution and overbank sedimentation, metal levels are elevated in most wetlands, which can cause adverse effects on the ecosystem's dynamics. Additionally, salinity affects the bioavailability of metals present or imported into these systems. The effect of different flooding regimes and salinity exposure scenarios (fresh- and brackish water conditions) on Cu and Zn accumulation in the oligochaete Tubifex tubifex (Mueller, 1774) was examined. Metal mobility was closely linked to redox potential, which is directly related to the prevalent hydrological regime. Flooded, and thus more reduced, conditions minimized the availability of metals, while oxidation of the substrates during a drier period was associated with a rapid increase of metal availability and accumulation in the oligochaetes. - Metal bioavailability in wetlands.

  11. Hydrological regime and salinity alter the bioavailability of Cu and Zn in wetlands

    International Nuclear Information System (INIS)

    In the context of the European Water Framework Directive, controlled flooding of lowlands is considered as a potential water management strategy to minimise the risk of flooding of inhabited areas. However, due to historical pollution and overbank sedimentation, metal levels are elevated in most wetlands, which can cause adverse effects on the ecosystem's dynamics. Additionally, salinity affects the bioavailability of metals present or imported into these systems. The effect of different flooding regimes and salinity exposure scenarios (fresh- and brackish water conditions) on Cu and Zn accumulation in the oligochaete Tubifex tubifex (Mueller, 1774) was examined. Metal mobility was closely linked to redox potential, which is directly related to the prevalent hydrological regime. Flooded, and thus more reduced, conditions minimized the availability of metals, while oxidation of the substrates during a drier period was associated with a rapid increase of metal availability and accumulation in the oligochaetes. - Metal bioavailability in wetlands.

  12. Bioavailability of the sodium pertechnetate and morphometry of organs isolated from rats: study of possible pharmacokinetic interactions of a ginkgo biloba extract

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Silvana Ramos Farias; Arnobio, Adriano; Caldas, Luiz Querino de Araujo [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Programa de Pos-graduacao em Ciencias Medicas]. E-mail: srfmoreno@hotmail.com; Carvalho, Jorge Jose; Nascimento, Ana Lucia; Pereira, Mario [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Dept. de Histologia e Embriologia; Dire, Glaucio; Bernardo Filho, Mario [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Dept. de Biofisica e Biometria; Rocha, Emely Kazan [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Dept. de Biologia Celular e Genetica

    2005-10-15

    Many compounds affect the bioavailability of radiobiocomplexes as radiopharmaceuticals. Ginkgo Biloba extract (EGb) has several effects. The influence of an EGb on the bioavailability of the radiobiocomplex sodium pertechnetate (Na{sup 99m} TcO{sub 4}) and on the morphometry of the organs was evaluated. Rats were treated with EGb and Na{sup 99m} TcO{sub 4} was injected. The animals were sacrificed; the radioactivity in the organs was counted. The results showed that EGb altered the Na{sup 99m} TcO{sub 4} bioavailability in the kidneys, liver and duodenum. Morphometric analysis of the organs showed significant alterations (P<0.05), probably caused by metabolites generated by EGb and capable of altering the bioavailability of the Na{sup 99m} TcO{sub 4}. (author)

  13. The geochemical behaviour of selenium in Boom Clay

    International Nuclear Information System (INIS)

    For the disposal of high-level radioactive waste (HLW) in a deep geological formation such as the Boom Clay, safety assessment studies have shown that the long-lived 79Se (halflife presently reassessed to approximately 295 ka) is one of the more critical fission products. Therefore, the understanding of its migration properties (diffusion, retention, sorption, solubility) through the geological barrier is of prime importance. The migration behaviour of selenium strongly depends on its chemical speciation. Under the reducing conditions prevailing in Boom Clay, selenide, [Se(-II)], is the thermodynamically stable species, and HSe- is expected to be the dominant selenium species in solution. The selenium migration should mainly be controlled by the low solubility of iron selenide such as FeSe or FeSe2, or solid solutions with seleniferous pyrite. However Se species are often found in redox disequilibrium and more soluble higher oxidation state [selenite: Se(+IV), and selenate: Se(+VI)] might also coexist if their reduction is kinetically hindered. Due to the unknown oxidation state of selenium in the waste form and the uncertainties related to the redox disequilibrium it is important to study the behaviour of selenium in all its oxidation states. The aim of the study on the behaviour of selenium in Boom Clay is to understand its chemical speciation under in situ conditions and especially the redox stability of selenite (SeO32-) and selenate (SeO42-) whose reduction kinetics can be extremely slow. Then, to determine for the various selenium species present in solution, their solubility, their sorption distribution coefficient (Kd approach), and their diffusion coefficient in Boom Clay to provide relevant conceptual models and associated transport parameters for safety assessment purposes. To achieve this objective, an interdisciplinary study was undertaken by SCK-CEN for ONDRAF/NIRAS in close collaboration with KULeuven and AEA Technology

  14. Treating chronic arsenic toxicity with high selenium lentil diets

    Energy Technology Data Exchange (ETDEWEB)

    Sah, Shweta [Department of Ecosystem and Public Health, Faculty of Medicine, University of Calgary, Calgary, AB T2N 4Z6 (Canada); Vandenberg, Albert [Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8 (Canada); Smits, Judit, E-mail: judit.smits@ucalgary.ca [Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6 (Canada)

    2013-10-01

    Arsenic (As) toxicity causes serious health problems in humans, especially in the Indo-Gangetic plains and mountainous areas of China. Selenium (Se), an essential micronutrient is a potential mitigator of As toxicity due to its antioxidant and antagonistic properties. Selenium is seriously deficient in soils world-wide but is present at high, yet non-toxic levels in the great plains of North America. We evaluate the potential of dietary Se in counteracting chronic As toxicity in rats through serum biochemistry, blood glutathione levels, immunotoxicity (antibody response), liver peroxidative stress, thyroid response and As levels in tissues and excreta. To achieve this, we compare diets based on high-Se Saskatchewan (SK) lentils versus low-Se lentils from United States. Rats drank control (0 ppm As) or As (40 ppm As) water while consuming SK lentils (0.3 ppm Se) or northwestern USA lentils (< 0.01 ppm Se) diets for 14 weeks. Rats on high Se diets had higher glutathione levels regardless of As exposure, recovered antibody responses in As-exposed group, higher fecal and urinary As excretion and lower renal As residues. Selenium deficiency caused greater hepatic peroxidative damage in the As exposed animals. Thyroid hormones, triiodothyronine (T3) and thyroxine (T4), were not different. After 14 weeks of As exposure, health indicators in rats improved in response to the high Se lentil diets. Our results indicate that high Se lentils have a potential to mitigate As toxicity in laboratory mammals, which we hope will translate into benefits for As exposed humans. - Highlights: • We reduce chronic arsenic toxicity in rats with a whole food solution. • High selenium lentils decrease liver damage and increase blood glutathione levels. • High selenium lentil diets increase urinary and fecal arsenic excretion. • High selenium lentil diets decrease arsenic levels in kidney, the storage organ. • High selenium lentil diets reverse arsenic suppression of the B cell

  15. Determination of selenium in egg by using GFAAS

    International Nuclear Information System (INIS)

    Complete text of publication follows. Egg is one of the most consumed food in the world. Its importance and consumption are raising due to its nutritional value. Selenium-fortified eggs can easily find in the local markets and the determination of selenium fortification level in egg is important because of its toxicity and essentially. The main aim of this work was to provide a simple, fast and accurate method for selenium determination in both commercially available eggs and selenium-fortified eggs. A number of procedures exist for the determination of selenium. However, as selenium exists in volatile and unstable forms and because of inhomogeneity of many types of materials, the methods of sampling, preparation and storage are equally important as the applied analytical methods. Therefore, great care is necessary to avoid contamination or loss of the analyte. In this study, a very simple and fast alternative dissolution procedure with tetramethyl ammonium hydroxide (THAH) was proposed. The samples simply mixed with a few millilitres of TMAH solution in an open flask. Dissolution was obtained in fifteen minutes with a low temperature heating which is around 60 deg C. Mild heating was found to be necessary not only for to reduce the dissolution time but also reduce the contamination risk. In the presence of modifiers (Pd, Pd+Mg as non permanent and Ru, Rh as permanent) selenium was analysed by using graphite furnace atomic absorption spectrometry (GFAAS) technique. The results were compared with modified AOAC standard spectrophotometric method. In order to test the accuracy of the proposed method, standard reference material, whole egg powder NIST-SRM 8415 was analysed and result was found to be in good agreement with the certified value, according to the t-test for a 95% confidence level. In addition, interference effect of species such as Fe, Zn, Cu, Al, Mg, Mn and Pb were also examined.

  16. Treating chronic arsenic toxicity with high selenium lentil diets

    International Nuclear Information System (INIS)

    Arsenic (As) toxicity causes serious health problems in humans, especially in the Indo-Gangetic plains and mountainous areas of China. Selenium (Se), an essential micronutrient is a potential mitigator of As toxicity due to its antioxidant and antagonistic properties. Selenium is seriously deficient in soils world-wide but is present at high, yet non-toxic levels in the great plains of North America. We evaluate the potential of dietary Se in counteracting chronic As toxicity in rats through serum biochemistry, blood glutathione levels, immunotoxicity (antibody response), liver peroxidative stress, thyroid response and As levels in tissues and excreta. To achieve this, we compare diets based on high-Se Saskatchewan (SK) lentils versus low-Se lentils from United States. Rats drank control (0 ppm As) or As (40 ppm As) water while consuming SK lentils (0.3 ppm Se) or northwestern USA lentils (< 0.01 ppm Se) diets for 14 weeks. Rats on high Se diets had higher glutathione levels regardless of As exposure, recovered antibody responses in As-exposed group, higher fecal and urinary As excretion and lower renal As residues. Selenium deficiency caused greater hepatic peroxidative damage in the As exposed animals. Thyroid hormones, triiodothyronine (T3) and thyroxine (T4), were not different. After 14 weeks of As exposure, health indicators in rats improved in response to the high Se lentil diets. Our results indicate that high Se lentils have a potential to mitigate As toxicity in laboratory mammals, which we hope will translate into benefits for As exposed humans. - Highlights: • We reduce chronic arsenic toxicity in rats with a whole food solution. • High selenium lentils decrease liver damage and increase blood glutathione levels. • High selenium lentil diets increase urinary and fecal arsenic excretion. • High selenium lentil diets decrease arsenic levels in kidney, the storage organ. • High selenium lentil diets reverse arsenic suppression of the B cell

  17. Intravenous Selenium Modulates L-Arginine-Induced Experimental Acute Pancreatitis

    Directory of Open Access Journals (Sweden)

    Jonathan Hardman

    2005-09-01

    Full Text Available Context Oxidative stress is understood to have a critical role in the development of acinar injury in experimental acute pancreatitis. We have previously demonstrated that compound multiple antioxidant therapy ameliorates end-organ damage in the intra-peritoneal L-arginine rat model. As the principal co-factor for glutathione, selenium is a key constituent of multiple antioxidant preparations. Objective The intention of this study was to investigate the effect of selenium on pancreatic and remote organ injury in a wellvalidated experimental model of acute pancreatitis. Methods Male Sprague-Dawley rats were randomly allocated to one of 3 groups (n=5/group and sacrificed at 72 hours. Acute pancreatitis was induced by 250 mg per 100 g body weight of 20% L-arginine hydrochloride in 0.15 mol/L sodium chloride. Group allocations were: Group 1, control; Group 2, acute pancreatitis; Group 3, selenium. Main outcome measures Serum amylase, anti-oxidant levels, bronchoalveolar lavage protein, lung myeloperoxidase activity, and histological assessment of pancreatic injury. Results L-arginine induced acute pancreatitis characterised by oedema, neutrophil infiltration, acinar cell degranulation and elevated serum amylase. Selenium treatment was associated with reduced pancreatic oedema and inflammatory cell infiltration. Acinar degranulation and dilatation were completely absent. A reduction in bronchoalveolar lavage protein content was also demonstrated. Conclusion Intravenous selenium given 24 hours after induction of experimental acute pancreatitis was associated with a reduction in the histological stigmata of pancreatic injury and a dramatic reduction in broncho-alveolar lavage protein content. Serum selenium fell during the course of experimental acute pancreatitis and this effect was not reversed by exogenous selenium supplementation.

  18. Selenium contamination of the Grasslands, a major California waterfowl area.

    Science.gov (United States)

    Ohlendorf, H M; Hothem, R L; Aldrich, T W; Krynitsky, A J

    1987-10-01

    In a recent study at Kesterson Reservoir in California, selenium was shown to cause mortality and deformities in embryos of aquatic birds. The present study was conducted to determine if selenium or other contaminants in agricultural drainwater used for marsh management were likely to cause similar adverse effects in the nearby Grasslands area. Selenium concentrations were elevated (greater than 15 ppm, dry-weight) in livers of some birds of all species collected from the Grasslands. Mean selenium concentrations in all species sampled in the South Grasslands were significantly higher (P less than 0.05) than those from the "control site", the Volta Wildlife Area. Mean selenium levels in black-necked stilts (Himantopus mexicanus) from the South Grasslands (35.6 ppm) were similar (P greater than 0.05) to levels in stilts from Kesterson (46.4 ppm), but means for American avocets (Recurvirostra americana) from the South Grasslands (67.3 ppm) were higher (P less than 0.05) than those from Kesterson (28.4 ppm). Bird eggs and fish from the Grasslands also contained elevated levels of selenium. Concentrations of eight heavy metals in fish generally reflected those patterns previously found in water entering the study areas. Of the organochlorines detected in fish, only DDE occurred at concentrations potentially harmful to birds (6.1 and 3.0 ppm, wet weight, at two South Grassland sites). The effect on avian health or reproduction of the other contaminants, singly or in combination, could not be determined. However, selenium levels were apparently sufficiently elevated in 1984 to have caused adverse effects on avian reproduction in the South Grasslands. PMID:3685947

  19. Demographic and lifestyle factors and selenium levels in men and women in the U.S.

    OpenAIRE

    Park, Kyong; Rimm, Eric; Siscovick, David; Spiegelman, Donna; Morris, J. Steven; Mozaffarian, Dariush

    2011-01-01

    Selenium is an antioxidant trace element linked to cardiovascular disease and cancer. Although diet is a major source, relatively little else is known about independent determinants of selenium levels in free-living humans. In this study, we aimed to investigate the independent demographic, lifestyle, and dietary determinants of selenium levels in 1,997 men and 1,905 women in two large prospective U.S. cohorts. Toenail selenium levels were quantified using neutron activation analysis. Diet, g...

  20. [Selenium contents in human milk after term and preterm labor and in breast milk substitutes].

    Science.gov (United States)

    Ladodo, K S; Iatsyk, G V; Oshchenko, A P; Skvortsova, V A; Fam Van Tkhu

    1997-01-01

    Selenium contents in breast milk of Russia's and Vietnam's women after term and preterm childbirth and in breast milk substitutes were studied. The concentration of selenium in breast milk of Russia's women was normal after term and preterm childbirth. The level of selenium in breast milk of Vietnam's women was decreased and could not satisfy completely the need of breasted infants. Selenium contents in babyfood "Malutka" Istra' manufacturing company were lower than those in Sybaj' company. PMID:9206891

  1. Deficient selenium status of a healthy adult Spanish population Deficiencia de selenio en una población adulta sana española

    Directory of Open Access Journals (Sweden)

    E. Millán Adame

    2012-04-01

    longerterm selenium status, while plasma selenium appears to be a marker of short-term nutritional status. The present findings indicate a positive correlation between plasma selenium concentration and the practice of physical activity. Bioavailability studies are required to establish appropriate reference levels of this mineral for the Spanish population.Introducción: El selenio es un micronutriente esencial para la salud del ser humano, debido fundamentalmente a su implicación como cofactor de enzimas con actividad antioxidante que protegen al organismo del daño oxidativo, de modo que una ingesta inadecuada de este mineral está asociada con la aparición y desarrollo de enfermedades crónicas tales como hipertensión, diabetes, enfermedades coronarias, asma y cáncer. Por esta razón, la determinación de selenio plasmático y eritrocitario contribuirá a la valoración del estado nutricional de la población estudiada. Objetivo: El objetivo de estudio fue valorar el estado nutricional de selenio en una población adulta sana en riesgo de deficiencia, a través de una evaluación de la ingesta, así como de los niveles de selenio en plasma y eritrocito, y la actividad de la enzima selenio-dependiente Glutation Peroxidasa (GPx en eritrocito. Material y métodos: El estudio se realizó en un grupo de población de 84 adultos sanos pertenecientes a la provincia de Granada (31 hombres y 53 mujeres en los que se determinó la ingesta de nutrientes y selenio, sus niveles plasmáticos y eritrocitarios, así como su asociación con la actividad de la enzima Glutation Peroxidasa y con diversos factores del estilo de vida. Resultados: Las concentraciones medias de selenio en plasma fueron de 76,6 ± 17,3 μg/L (87,3 ± 17,4 μg/L en los hombres, y de 67,3 ± 10,7 μg/L para las mujeres, mientras que los valores eritrocitarios de selenio de la poblacion total del estudio fue de 104,6 μg/L (107,9 ± 26,1 μg/L en hombres y 101,7 ± 21,7 μg/L en mujeres. La evaluacion del estado

  2. Sorption of selenium(IV) and selenium(VI) onto magnetite

    International Nuclear Information System (INIS)

    In this work, we have studied the sorption of selenium (79Se is one of the main radionuclides in a spent nuclear fuel repository) on magnetite (Fe3O4), a mineral present in the near-field of a nuclear waste repository that might represent an important retardation factor for the mobility of many radionuclides. The sorption of both Se(IV) and Se(VI) onto magnetite has been fitted by a non-competitive Langmuir isotherm with Γ max = (3.13 ± 0.07) x 10-6 mol m-2 and K L = (1.19 ± 0.07) x 106 dm3 mol-1 for Se(IV) and Γ max = (3.5 ± 0.2) x 10-6 mol m-2 and K L = (3.0 ± 0.1) x 105 dm3 mol-1 for Se(VI). The variation of the sorption of selenium with pH has been modeled using the Triple Layer Surface Complexation Model and the equilibrium constants between selenium and magnetite have been obtained using the FITEQL program. For the case of Se(IV), the best fitting has been obtained using two inner-sphere complexes, FeOHSeO32- and FeHSeO3, while for Se(VI), the best fitting has been obtained considering only an outer-sphere complex, FeOH2+ -SeO42-. The surface complexation reactions derived in this work are in agreement with those stated by other authors for sorption of Se(IV) and Se(VI) on hydrous iron oxides

  3. The selenium content of SEPP1 versus selenium requirements in vertebrates

    Science.gov (United States)

    Hamre, Kristin; Ellingsen, Ståle

    2015-01-01

    Selenoprotein P (SEPP1) distributes selenium (Se) throughout the body via the circulatory system. For vertebrates, the Se content of SEPP1 varies from 7 to 18 Se atoms depending on the species, but the reason for this variation remains unclear. Herein we provide evidence that vertebrate SEPP1 Sec content correlates positively with Se requirements. As the Se content of full length SEPP1 is genetically determined, this presents a unique case where a nutrient requirement can be predicted based on genomic sequence information. PMID:26734501

  4. A case-control study of the relation between plasma selenium and asthma in European populations

    DEFF Research Database (Denmark)

    Burney, P; Potts, J; Makowska, J;

    2008-01-01

    BACKGROUND: There is evidence that selenium levels are relatively low in Europe and may be falling. Low levels of selenium or low activity of some of the enzymes dependent on selenium have been associated with asthma. METHODS: The GA(2)LEN network has organized a multicentre case-control study in...

  5. Selenium containing clays minerals as additive for the discoloration of glass

    NARCIS (Netherlands)

    Timmer, K.; Limpt, J.A.C. van; Fischer, H.R.

    2010-01-01

    While selenium is applied as decolorizing agent for flint container glass or tableware glass, the retention of selenium in glass however is very low. Generally more than 75% of the total selenium input sublimes from the glass melt and leaves the clay minerals due to the high volatility of SeO2<

  6. Construction of Chaihu Selenium Industrial Demonstration Area in Zhongxiang City of Hubei Province

    Institute of Scientific and Technical Information of China (English)

    Guangzhong; DAI

    2014-01-01

    In order to develop selenium industry in Jianghan Basin,Hubei Provincial Party Committee decided to build Chaihu selenium industrial demonstration area in Zhongxiang City.This paper introduced general situation of Chaihu Town,analyzed countermeasures for construction of selenium industrial demonstration area in depth,and finally came up with 12 constructive and pertinent recommendations.

  7. Neutron activation analysis applied to the determination of selenium in bovine plasma

    International Nuclear Information System (INIS)

    The procedure used to determine selenium in bovine plasma by neutron irradiation of the samples, followed by a radiochemical separation, is described. This procedure allows the direct determination of the value of the selenium plasmatic level, instead of the indirect conventional method that determines the blood glutathion peroxidase enzyme, as an indicator of the selenium content in the blood. (author)

  8. Biodisponibilidade do licopeno Bioavailability of lycopene

    Directory of Open Access Journals (Sweden)

    Bettina Moritz

    2006-04-01

    Full Text Available Esta revisão procura reunir diversos estudos que avaliam os fatores que influenciam a biodisponibilidade do licopeno, bem como os alimentos fontes e a recomendação de ingestão desse carotenóide. Para tanto, foi realizado um levantamento bibliográfico, mediante consulta às bases de dados Medline (National Library of Medicine, USA e Lilacs (Bireme, Brasil nas quais foram selecionadas publicações científicas em português e inglês, nos últimos quinze anos, que utilizaram os temas: licopeno, carotenóides e/ou biosponibilidade. O licopeno é um carotenóide sem atividade de pró-vitamina A, mas um potente antioxidante, sendo essa função possivelmente associada à redução do risco da ocorrência do câncer e certas doenças crônicas. Esse nutriente é encontrado em um número limitado de alimentos, e, além disso, o organismo não é capaz de sintetizá-lo; dessa forma, o licopeno é obtido exclusivamente por meio da dieta alimentar. A quantidade sugerida de ingestão de licopeno varia de 4 a 35mg/dia. Estudos mostram que existem vários fatores que podem interferir na biodisponibilidade do licopeno, tais como absorção intestinal, quantidade de licopeno no alimento fonte, formas de apresentação (isômeros e sintéticos, presença da matriz alimentar, presença de outros nutrientes na refeição (como gordura, fibra, outros carotenóides, entre outros, ingestão de drogas, processamento do alimento, além da individualidade biológica e do estado nutricional do indivíduo. Estudos da biodisponibilidade do licopeno têm sido desenvolvidos a partir do tomate e seus produtos, por esse ser a fonte mais comumente consumida. O desenvolvimento do estudo enfatizou a importância da melhor forma de absorção desse nutriente, relevante que é para a prevenção de inúmeras doenças.This review collets several papers that evaluated the factors that influence the bioavailability of licopene, as well as the food sources of this nutrient and

  9. Bioavailability of magnetic nanoparticles to the brain

    Energy Technology Data Exchange (ETDEWEB)

    Huang, B.-R. [Department of Neurosurgery, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, 5 Fushing Street, Kweishan, Taoyuan 333, Taiwan (China); Chen, P.-Y. [Department of Neurosurgery, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, 5 Fushing Street, Kweishan, Taoyuan 333, Taiwan (China); Graduate Institute of Biomedical Sciences, Chang-Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Taoyuan 333, Taiwan (China); Huang, C.-Y. [Department of Neurosurgery, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, 5 Fushing Street, Kweishan, Taoyuan 333, Taiwan (China); Jung, S.-M. [Department of Pathology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, 5 Fushing Street, Kweishan, Taoyuan 333, Taiwan (China); Ma, Y.-H. [Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China); Wu, Tony [Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, 5 Fushing Street, Kweishan, Taoyuan 333, Taiwan (China); Chen, J.-P. [Department of Chemical and Material Engineering, College of Medicine, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan (China)], E-mail: jpchen@mail.cgu.edu.tw; Wei, K.-C. [Department of Neurosurgery, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, 5 Fushing Street, Kweishan, Taoyuan 333, Taiwan (China)], E-mail: kuochenwei@adm.cgmh.org.tw

    2009-05-15

    This study investigates the bioavailability of carboxymethyl dextran-coated magnetic nanoparticles (CMD-MNP) to the brain. The cytotoxicity of CMD-MNP was assessed by co-culture with C6, a rat glioma cell line. To investigate the effects of an external magnetic field on the biodistribution of nanoparticles in a rat model, a magnet of 0.3 Tesla was applied externally over the cranium and the particles injected via the external jugular vein. Nanoparticles were also injected into rats implanted with C6 tumor cells. Staining of histological samples with Prussian blue to detect iron particles revealed that the external magnetic field enhanced the aggregation of nanoparticles in the rat brain; this enhancement was even more pronounced in the tumor region.

  10. Bioavailability of magnetic nanoparticles to the brain

    International Nuclear Information System (INIS)

    This study investigates the bioavailability of carboxymethyl dextran-coated magnetic nanoparticles (CMD-MNP) to the brain. The cytotoxicity of CMD-MNP was assessed by co-culture with C6, a rat glioma cell line. To investigate the effects of an external magnetic field on the biodistribution of nanoparticles in a rat model, a magnet of 0.3 Tesla was applied externally over the cranium and the particles injected via the external jugular vein. Nanoparticles were also injected into rats implanted with C6 tumor cells. Staining of histological samples with Prussian blue to detect iron particles revealed that the external magnetic field enhanced the aggregation of nanoparticles in the rat brain; this enhancement was even more pronounced in the tumor region.

  11. Gender differences on bioavailability of ofloxacin

    International Nuclear Information System (INIS)

    The fluoroquinolones are currently enjoying extensive worldwide clinical applications because of their good bioavailability and pharmacokinetic profile. Investigation into several aspects of the pharmacokinetic of all clinically relevant fluoroquinolones, have been carried out notably in Europe, USA and Japan. In view of the geonetical (geographical influences on genetics-pharmacogenetics) differences, it is important that for the optimal therapeutic outcome, biodisposition studies on drugs are better conducted in the population and environments where wide and extensive use of the drug is anticipated. The Objectives of study were to see the pharmacokinetic parameters in healthy young male and female volunteers. This comparative study was conducted King Edward Medical University, Lahore, Pakistan, from July 2005 to December 2005. In Pakistan where the use of antibiotics is more frequent by the general practitioners it is important to elucidate certain dose parameters it is also noticed that side effects are more in females than males so present study is conducted to calculate any differences in bioavailability on the basis of sex. The pharmacokinetic parameters of ofloxacin were determined in each of the clinically health eight young girls and boys (mean age 23.9 and 25.1 years, respectively) following a single oral dose of 400 mg tablet. The method adopted was microbiological assay. The blood samples collected at predetermined time intervals after drug administration revealed almost twice as high concentration of the drug in plasma of the girls than that in the boys. The pharmacokinetic parameters revealed significantly (p<0.01) higher values for area under curve (AUC) and Cmax, and lower total body clearance (TBC) and volume of distribution in the girls than in the boys. The gender differences in pharmacokinetic parameters indicate that the dose adjustment should be considered in male and female. (author)

  12. Bioavailability of vitamin A sources for cattle.

    Science.gov (United States)

    Alosilla, C E; McDowell, L R; Wilkinson, N S; Staples, C R; Thatcher, W W; Martin, F G; Blair, M

    2007-05-01

    An experiment was conducted to evaluate the bioavailability of 5 sources of vitamin A. It was hypothesized that some vitamin A products have protective coatings that are more resistant than others to rumen destruction and that such protection would result in greater tissue concentrations of vitamin A. Fifty-three yearling Angus x Brahman cattle, consisting of 39 steers and 14 heifers, were stratified by BW and sex and randomly assigned to 6 high-concentrate diet groups receiving no vitamin A supplementation (control) or vitamin A supplemented from the following sources: Microvit A (Adisseo, Acworth, GA), Rovamix A (DSM, Parsippany, NJ), Sunvit A, Lutavit A, and Microvit A DLC (Adisseo). The vitamin A treatment groups were fed daily 80,000 IU of retinol/animal in a low-retinol concentrate diet (78.5% oats, 10% cottonseed hulls, 8% molasses, and 2% cottonseed meal; DM basis) and a free-choice, poor quality (low carotene) hay for 84 d. Every 28 d, BW was determined and liver biopsies and plasma were collected and analyzed for retinol concentrations. All retinol treatments showed significant increases in liver retinol concentrations compared with control animals (P < 0.0001), which steadily decreased over time. At all collection times, Microvit A led to numerically, but not significantly, greater concentrations of retinol in liver than did all other treatments. However, at the end of the experiment, there was no significant difference in liver retinol concentration among Microvit A, Rovamix A, Lutavit A, and Microvit A DLC diets. When liver retinol concentrations at all collection times were considered, Microvit A and Rovamix A appeared to provide the most bioavailable vitamin A. PMID:17178810

  13. Evaluation of the toxicity of selenium from hydroponically produced selenium-enriched kale sprout in laying hens.

    Science.gov (United States)

    Chantiratikul, Anut; Borisuth, Lalita; Chinrasri, Orawan; Saenthaweesuk, Nattanan; Chookhampaeng, Sumalee; Thosaikham, Witphon; Sriart, Noppong; Chantiratikul, Piyanete

    2016-05-01

    Hydroponically produced Se-enriched kale sprouts (HPSeKS) are studied for their use as an alternative dietary Se supplement for poultry. The study experimented with different levels and sources of Se to determine toxicity and how the toxicity may affect productive performance, Se concentration in egg and tissues, and physiological responses of laying hens. One-hundred and twenty hens, 59 weeks of age, were divided into 5 groups. Each group consisted of 4 replicates and each replicate had 6 birds according to a 2×2+1 Augmented Factorial Experiment in a Completely Randomized Design. The experiment was conducted over a 4 week period, and 5 dietary treatments (T) were used: T1 basal diet, T2 and T3 basal diet plus 5 and 10mg Se/kg from sodium selenite (SS), T4 and T5 basal diet plus 5 and 10mg Se/kg from HPSeKS, respectively. The results make clear that Se from HPSeKS, at 5-10mg/kg, did not affect (P>0.05) feed intake and egg production; however, Se bioavailability decreased (Phens fed Se from SS were lower (Phens fed Se from HPSeKS. The findings demonstrate that dietary Se from HPSeKS at 5-10mg/kg is not considered a toxic level for laying hens. The toxicity of Se from HPSeKS was less than the toxicity of Se from SS. PMID:26964695

  14. Hydrological and geochemical investigations of selenium behavior at Kesterson Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Benson, S.M.; Tokunaga, T.K.; Zawislanski, P.; Yee, A.W.; Daggett, J.S.; Oldfather, J.M.; Tsao, L.; Johannis, P.W.

    1990-10-01

    From 1985 to the present we have studied the behavior of selenium in various habitats and environments at Kesterson reservoir, shifting emphasis as remedial actions altered the physical setting. Investigations have evaluated the efficacy of several remedial alternatives, from innovative techniques relying on the complex geochemical behavior of selenium alternatives, from innovative techniques relying on the complex geochemical behavior of selenium in aquatic environments to conventional excavation schemes. Results of these studies supported two cost-effective remedial measures; drain water deliveries were terminated in 1986 and, in 1988, 1 million cubic yards of soil were imported and used to fill the low lying areas of the former Kesterson Reservoir. To date, these two actions appear to have eliminated the aquatic habitat that caused waterfowl death and deformity at Kesterson from the early 1980's to 1987. Biological, surface water and groundwater monitoring data collected by the USBR indicate that Kesterson is now a much safer environment than in past years when drainage water containing 300{mu}g/l of selenium was delivered to the Reservoir. The continued presence of a large inventory of selenium within the upper portions of unfilled areas of Kesterson Reservoir and immediately below the fill material requires that a continued awareness of the status of this inventory be maintained and improved upon. 83 refs., 130 figs., 19 tabs.

  15. Early effects of selenium preparation on radiation pneumonia

    International Nuclear Information System (INIS)

    In order to provide experimental basis for drug efficacy of preventing and treating radiation pneumonia, the authors observed the early effects of selenium preparation on the radiation pneumonia. Wistar male rats were divided into three groups of 48 rats: the control group, the irradiated group and the irradiated plus selenium preparation treated group. The animals received thoracic irradiation of 15 Gy, and were killed at 0.5, 1,2,3 months post irradiation. Lung tissues were processed for light microscopy and isolation of RNA. Expression of type I(III) collagen was evaluated by dot-blot hybridization and image analysis technique. Pathological study showed marked lung injury in the irradiated group while only slight hyperemia, hemorrhage, exudation and thickness of alveolar walls in the lungs of selenium preparation-treated group. The synthesis of type I and III collagen mRNA also decreased in the selenium preparation-treated group. Selenium preparation could have protective and therapeutic effects on radiation pneumonia

  16. Acute selenium toxicosis induced in baby pigs by parenteral administration of selenium-vitamin E preparations

    Energy Technology Data Exchange (ETDEWEB)

    Van Vleet, J.F.; Meyer, K.B.; Olander, H.J.

    1974-09-15

    Acute selenium (Se) toxicosis was induced in baby pigs by intramuscular (IM) injection of Se, as selenite, using commercially available selenium-vitamin E (Se-E) preparations. Graded amounts of Se were given to 26 pigs from a herd that had not experienced losses from Se-E deficiency and to 136 pigs from a herd that had continual losses from Se-E deficiency. Of the 2 groups of pigs, those from the Se-E-deficient herd were more susceptible to acute Se toxicosis. Clinical signs of toxicosis were vomiting, anorexia, depression, dyspnea, weakness, and coma, with death occurring 24 to 48 hours after injection. Pathologic alterations observed grossly and histologically included pulmonary edema, skeletal myodegeneration, hepatic degeneration and necrosis, transudation into body cavities, and widespread circulatory disturbances. Mean tissue Se concentrations in 20 pigs with acute toxicosis 24 to 48 hours after injection were 12.44 ppm in liver, 1.31 ppm in kidney, and 0.32 ppm in skeletal muscle.

  17. High performance amorphous selenium lateral photodetector

    Science.gov (United States)

    Abbaszadeh, Shiva; Allec, Nicholas; Karim, Karim S.

    2012-03-01

    Lateral amorphous selenium (a-Se) detectors based on the metal-semiconductor-metal (MSM) device structure have been studied for indirect detector medical imaging applications. These detectors have raised interest due to their simple structure, ease of fabrication, high-speed, low dark current, low capacitance per unit area and better light utilization. The lateral device structure has a benefit that the electrode spacing may be easily controlled to reduce the required bias for a given desired electric field. In indirect conversion x-ray imaging, the scintillator is coupled to the top of the a-Se MSM photodetector, which itself is integrated on top of the thin-film-transistor (TFT) array. The carriers generated at the top surface of the a-Se layer experience a field that is parallel to the surface, and does not initially sweep them away from the surface. Therefore these carriers may recombine or get trapped in surface states and change the field at the surface, which may degrade the performance of the photodetector. In addition, due to the finite width of the electrodes, the fill factor of the device is less than unity. In this study we examine the effect of lateral drift of carriers and the fill factor on the photodetector performance. The impact of field magnitude on the performance is also investigated.

  18. Selenium speciation in flue desulfurization residues

    Institute of Scientific and Technical Information of China (English)

    Liping Zhong; Yan Cao; Wenying Li; Kechang Xie; Wei-Ping Pan

    2011-01-01

    Flue gas from coal combustion contains significant amounts of volatile selenium (Se).The capture of Se in the flue gas desulfurization (FGD) scrubber unit has resulted in a generation of metal-laden residues.It is important to determine Se speciation to understand the environmental impact of its disposal.A simple method has been developed for selective inorganic Se(Ⅳ), Se(Ⅵ) and organic Se determination in the liquid-phase FGD residues by hydride generation atomic fluorescence spectrometry (AFS).It has been determined that Se(Ⅳ), Se(Ⅵ) and organic Se can be accurately determined with detection limits (DL) of 0.05, 0.06 and 0.06 μg/L, respectively.The accuracy of the proposed method was evaluated by analyzing the certified reference material, NIST CRM 1632c, and also by analyzing spiked tap-water samples.Analysis indicates that the concentration of Se is nigh in FGD liquid residues and primarily exists in a reduced state as selenite (Se(Ⅳ)).The toxicity of Se(Ⅳ) is the strongest of all Se species.Flue gas desulfurization residues pose a serious environmental risk.

  19. Selenium speciation in flue desulfurization residues.

    Science.gov (United States)

    Zhong, Liping; Cao, Yan; Li, Wenying; Xie, Kechang; Pan, Wei-Ping

    2011-01-01

    Flue gas from coal combustion contains significant amounts of volatile selenium (Se). The capture of Se in the flue gas desulfurization (FGD) scrubber unit has resulted in a generation of metal-laden residues. It is important to determine Se speciation to understand the environmental impact of its disposal. A simple method has been developed for selective inorganic Se(IV), Se(VI) and organic Se determination in the liquid-phase FGD residues by hydride generation atomic fluorescence spectrometry (AFS). It has been determined that Se(IV), Se(VI) and organic Se can be accurately determined with detection limits (DL) of 0.05, 0.06 and 0.06 microg/L, respectively. The accuracy of the proposed method was evaluated by analyzing the certified reference material, NIST CRM 1632c, and also by analyzing spiked tap-water samples. Analysis indicates that the concentration of Se is high in FGD liquid residues and primarily exists in a reduced state as selenite (Se(IV)). The toxicity of Se(IV) is the strongest of all Se species. Flue gas desulfurization residues pose a serious environmental risk. PMID:21476358

  20. Investigation of the selenium metabolism in cancer cell lines

    DEFF Research Database (Denmark)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan;

    2011-01-01

    The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line...... (Jurkat E6-1) were incubated with five selenium compounds representing inorganic as well as organic Se compounds in different oxidation states. Selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), methylseleninic acid (MeSeA), selenite and selenate in the concentration range 5-100 mu M were...... incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size...

  1. Structure of amorphous selenium studied by neutron diffraction

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Knudsen, Torben Steen; Carneiro, K.

    1975-01-01

    Neutron diffraction measurements on amorphous selenium have been performed at 293 and 80 K. Careful analyses of the instrumental corrections were made to avoid systematic errors in the measured structure factor S (kappa) in the wave vector region 0 ? kappa ? 12 Å−1. As a result of the data...... treatment, the neutron scattering cross sections of selenium are determined to be sigmacoh = 8.4±0.1 b and sigmainc = 0.1±0.1 b. Using the fact that S (kappa) for large kappa's is determined by the short distances in the sample, a new method for extrapolation of the experimental S (kappa) until convergence...... considered. Finally, we give a brief discussion of the different models for the structure of amorphous selenium, taking both diffraction measurements and thermodynamic considerations into account. The Journal of Chemical Physics is copyrighted by The American Institute of Physics....

  2. Selenium content of sulfide ores related to ophiolites of Greece.

    Science.gov (United States)

    Economou-Eliopoulos, M; Eliopoulos, D G

    1998-01-01

    Several deposits of sulfide mineralization have been described in the ophiolites of Greece. Based on their mineralogical and chemical composition and the host rocks, two types can be distinguished: (1) the Fe-Cu-Ni-Co type consisting of pyrrhotite, chalcopyrite, Co-pentlandite, pyrite, magnetite + arsenides, +/- chromite, hosted in serpentinites, gabbros or diabases, which have variable geochemical characteristics, and (2) sulfide mineralization of the Cyprus type containing variable proportions of pyrite, chalcopyrite, bornite, and sphalerite. The spatial association with shear zones and fault systems, which is a common feature in both types of mineralization, provided the necessary permeability for the circulation of the responsible mineralized hydrothermal fluids. The selenium (Se) content in representative samples of both types of mineralization from the ophiolites of Pindos (Kondro, Perivoli, and Neropriona), Othrys (Eretria and A. Theodoroi), Veria (Trilofon), and Argolis (Ermioni) shows a wide variation. The highest values of Se (130 to 1900 ppm) were found in massive Fe-Cu sulfide ores from Kondro, in particular the Cu-rich portions (average 1300 ppm Se). The average values of Se for the Othrys sulfides are low (< 40 ppm Se). The Se content in a diabase breccia pipe (50 x 200 m) with disseminated pyrite mineralization (Neropriona) ranges from < 1 to 35 ppm Se. The highest values were noted in strongly altered samples that also exhibited a significant enrichment in platinum (1 ppm Pt). Sulfide mineralization (irregular to lens-like masses and stringers) associated with magnetite, hosted in gabbros exposed in the Perivoli area (Tsouma hill), shows a content ranging from 40 to 350 ppm Se. The distribution of Se in the studied type of the sulfide mineralization may be of genetic significance, indicating that the Se level, which often is much higher than in typical magmatic sulfides related to mafic-ultramafic rocks (average 90-100 ppm Se), may positively affect

  3. Selenium status and cancer mortality in subjects residing in four Canadian provinces

    International Nuclear Information System (INIS)

    Selenium status in male and female Canadian subjects was measured relative to cancer mortality in their respective provinces. Toenail specimens from 755 subjects, 377 males and 378 females, living in Vancouver (186), Edmonton (188), Toronto (197) and Montreal (184) were analyzed by instrumental neutron activation analysis giving means of 0.968 ± 0.177, 0.950 ± 0.148, 0.932 ± 0.135 and 0.896 ± 0.127 ppm Se, respectively. The effect of selenium determinants such as gender, selenium supplementation and smoking on selenium status is presented. Details of the observed inverse relationship of selenium status and cancer mortality are discussed. (author)

  4. Effect of Nitric Oxide, Vitamin E and Selenium on Streptozotocin induced diabetic rats

    International Nuclear Information System (INIS)

    Diabetes mellitus is characterized by a series of complications that may affect many organs. This study aimed to investigate the role of nitric oxide (NO) as a physiological mediator in the body via the use of L-arginine as NO precursor Ng-nitro-arginine methyl ester (L-NAME) as Nitric oxide synthase (NOS) enzyme inhibitor in diabetic rats. The effect of vitamin E as antioxidant and selenium as a potent insulin-mimetic agent in diabetic rats were studied. The possible combination of selenium or vitamin E with L-arginine was studied in the same animal model to show the ability of these treatments to ameliorate some of the biochemical changes that are worsen with the development of diabetes such as lipid profile, plasma glucose, blood malondialdehyde (MDA), plasma nitric oxide and plasma b-2 microglobulin levels. Experimental diabetes was induced in male rats by I.V. injection of Streptozotocin (STZ) (50mg/kg). Diabetic rats showed a significant increase (P<0.05) in the plasma level of glucose, triglycerides, total cholesterol, LDL-cholesterol, b2-micro globulin, blood MDA as a result of increased oxidative stress while there was a significant decrease in plasma HDL-cholesterol, and nitrate/nitrite levels. L-arginine, vitamin E and selenium administration produced a significant decrease in plasma glucose level of diabetic arts (13%, 29.11%, 61.65%) respectively from its initial value, so as they showed a significant reduction in blood MDA level, plasma triglyceride, total cholesterol, LDL-Ch.. levels when compared with the initial diabetic values. Combined therapy of vitamin E and L-arginine showed no significant change of any of the measured parameters (except for nitrate/nitrite level) on comparison either with vitamin E or with L-arginine treated group. The combined therapy of selenium and L-arginine showed a significant decrease nearly to normal level in the plasma glucose concentration and may be of clinical significance. (author)

  5. Geochemical processes controlling dissolved selenium in the Changjiang (Yangtze) Estuary and its adjacent waters

    Institute of Scientific and Technical Information of China (English)

    WU Xiaodan; SONG Jinming; WU Bin; LI Tiegang; LI Xuegang

    2014-01-01

    Dissolved selenium in the Changjiang (Yangtze) Estuary and its adjacent waters was determined by hy-dride generation atomic fluorescence spectrometry to elucidate the source, behavior in estuary, adsorp-tion-desorption process and biological role. In surface water, Se(IV ) concentration ranged 0.05-1.14 nmol/L and Se(VI) concentration varied 0.01-1.20 nmol/L, with the means of 0.76 and 0.49 nmol/L, respectively. In bottom water, Se(IV) content varied 0.03-0.27 nmol/L and Se(VI) content ranged 0.04-0.85 nmol/L, with the averages of 0.10 and 0.40 nmol/L, respectively. High level of Se(IV ) was observed near the shore with a significant decrease towards the open sea, suggesting the continental input from the adjacent rivers. Large value of Se( VI) was found in bottom water, reflecting the release from suspended sediment. Besides, high value appeared in the same latitude of the Changjiang Estuary and Hangzhou Bay illustrated the effect of lat-eral mixing and the long-distance transport of selenium. Se(VI), more soluble, occupied higher percentage in aqueous environment. The presence of Se(IV ) resulted from the degradation of residue and the reduction of Se(VI) under anaerobic condition. The positive relationship to suspended particulate material (SPM) and negative correlation to depth indicated that Se(IV ) tended to be released from the high density particulate matter. Instead, Se(VI) content did not significantly relate to SPM since it generally formed inner-sphere complex to iron hydroxide. Se(IV ) content negatively varied to salinity and largely depended on the fresh-water dilution and physical mixing. While, Se( VI) level deviated from the dilution line due to the in situ bio-geochemical process such as removal via phytoplankton uptake and inputs via organic matter regeneration. As the essential element, Se(IV) was confirmed more bioavailable to phytoplankton growth than Se(VI), and moreover, seemed to be more related to phosphorus than to nitrogen.

  6. Probing for the Activities of Arsenic and Selenium Metabolizing Microbes

    Science.gov (United States)

    Stolz, J. F.

    2007-12-01

    Microbial activities can directly impact the mobility and toxicity of arsenic and selenium in the environment. Arsenic is cycled through oxidation/reduction and methylation/demethylation reactions as part of resistance and respiratory processes. The requirement for selenium is primarily for incorporation into selenocysteine and its function in selenoenzymes. Selenium oxyanions can also serve as an electron acceptor in anaerobic respiration. Both culture and culture-independent methods have been developed to detect the presence and activity of organisms capable of arsenic and selenium transformations. Enrichment media have been successful at cultivating arsenate respiring bacteria from a variety of environments, however, both electron donor and the concentration of arsenic can exert strong selective pressure. Thus, the organisms in the enrichment culture may not be the dominant organisms in the environment. Culture-independent methods, including immunological approaches (e.g., polyclonal antibodies to ArrA) and PCR-based technologies, have also had mixed success. PCR-primers designed to amplify portions of genes involved in resistance (e.g., arsC, acr3), respiration (e.g., arrA), and oxidation (e.g., aoxB) have been useful in several environments. Applications include T-RFLP, rt-PCR, and DGGE analyses. Nevertheless, these primers do not work with certain organisms suggesting the existence of additional enzymes and pathways. Although the biosynthetic pathway (and the proteins involved) for selenocysteine has been described in detail, much less is known about selenium methylation, assimilation and respiration. Only one respiratory selenate reductase has been characterized and its close sequence identity with chlorate and perchlorate reductases has complicated efforts to design a functional probe. Thus many aspects of the biogeochemical cycle of selenium remains to be explored.

  7. The influence of selenium addition during germination of Brassica seeds on health-promoting potential of sprouts.

    Science.gov (United States)

    Piekarska, Anna; Kołodziejski, Dominik; Pilipczuk, Tadeusz; Bodnar, Małgorzata; Konieczka, Piotr; Kusznierewicz, Barbara; Hanschen, Franziska S; Schreiner, Monika; Cyprys, Joanna; Groszewska, Milena; Namieśnik, Jacek; Bartoszek, Agnieszka

    2014-09-01

    The correlation among selenium uptake, the content of bioactive compounds in sprouts, and biological activities triggered in cultured human cells by sprout extracts was investigated. Seeds of Brassica crops and rye were treated with SeO2 water solution. The selenium levels in sprouts increased from 1.0-4.1 to 53.3-382 μg/g dw with no influence on plant physiology according to the indices used. Neither the composition of glucosinolates (GL) in Brassica sprouts nor the myrosinase activity nor the composition of GL breakdown lipophilic products were significantly affected. In all Brassica sprouts, conversion to health-promoting isothiocyanates (ITC) and indoles corresponded to only 1% of total GLs. Low ITC concentration may explain observed lack of induction of glutathione S-transferases (GST) and quinone oxidoreductase (NQO) detoxifying enzymes in HT29 cells exposed to sprout extracts. The insignificant impact on cell growth and genome function suggests that Brassica sprouts may be safe vehicle of selenium to combat its dietary deficiency. PMID:24827602

  8. Bioavailability of Silica, Titanium Dioxide, and Zinc Oxide Nanoparticles in Rats.

    Science.gov (United States)

    Kim, Mi-Kyung; Lee, Jeong-A; Jo, Mi-Rae; Choi, Soo-Jin

    2016-06-01

    Inorganic nanoparticles have been widely applied to various industrial fields and biological applications. However, the question as to whether nanoparticles are more efficiently absorbed into the systemic circulation than bulk-sized materials remains to be unclear. In the present study, the physico-chemical and dissolution properties of the most extensively developed inorganic nanoparticles, such as silica (SiO2), titanium dioxide (TiO2), and zinc oxide (ZnO), were analyzed, as compared with bulk-sized particles. Furthermore, the bioavailability of nanoparticles versus their bulk counterparts was evaluated in rats after a single oral administration and intravenous injection, respectively. The results demonstrated that all bulk materials had slightly higher crystallinity than nanoparticles, however, their dissolution properties were not affected by particle size. No significant difference in oral absorption and bioavailability of both SiO2 and TiO2 was found between nano- and bulk-sized materials, while bulk ZnO particles were more bioavailable in the body than ZnO nanoparticles. These finding will provide critical information to apply nanoparticles with high efficiency as well as to predict their toxicity potential. PMID:27427756

  9. Effect of biochar amendment on the bioavailability of pesticide chlorantraniliprole in soil to earthworm.

    Science.gov (United States)

    Wang, Ting-Ting; Cheng, Jie; Liu, Xian-Jin; Jiang, Wayne; Zhang, Chao-Lan; Yu, Xiang-Yang

    2012-09-01

    To evaluate the effect of biochar amendment on the bioavailability of chlorantraniliprole (CAP) in soils with different physico-chemical properties, the uptake of CAP from various soils by earthworms was studied. It was observed that the biochar amendment of the soils affected the sorption of CAP, but the magnitude of the sorption enhancement by biochar amendment among the soils was varied, presumably due to the attenuation of the sorptivity of the biochar when amended in the soil. The amendment with biochars leads to a decrease in the bioavailability of CAP in the soils to earthworms, and more prominent for biochar BC850 amendment. In the soil with a CAP concentration of 10 mg kg(-1), the residue of CAP in the earthworm tissues was found to be 9.65 mg kg(-1), in comparison with that the CAP residue was 4.05 mg kg(-1) in BC450 amended soil and 0.59 mg kg(-1) in BC850, respectively. The degree of bioavailability reduction by same level of biochar amendment was different among soils with different properties. The results demonstrate that the properties of soils are important to performance of biochar in soil. PMID:22776710

  10. Speciation and bioavailability of soil nutrients: effect on crop production and environment

    Directory of Open Access Journals (Sweden)

    Elisabetta Barberis

    Full Text Available The agricultural production, determining the quality of the foodstuffs, depends on the biological characteristics of the crops and on the environmental properties, where soil environment plays a central role. Crops absorb water and nutritive elements from soil, but they can intake toxic elements as well. The potential benefits, or dangers, due to the presence of a certain element in soil, depend on its chemical speciation regulating its bioavailability, toxicity, environmental mobility, and biogeochemistry. Elements may exist in soil in different redox species and organic or inorganic forms. They may thus undergo different chemical processes occurring in solution, in the solid phase, or at the solid-water interface. The chemical speciation and bioavailability of the elements are affected by soil and environmental properties, which may undergo natural or anthropogenic modifications. As an example, we reported here some aspects linked to the chemical speciation, bioavailability and environmental fate of two chemically similar elements. The former, phosphorus, is a macronutrient element, essential for plant growth, while the latter, arsenic, is strongly toxic for most living organisms.

  11. The effect of proteins from animal source foods on heme iron bioavailability in humans.

    Science.gov (United States)

    Pizarro, Fernando; Olivares, Manuel; Valenzuela, Carolina; Brito, Alex; Weinborn, Valerie; Flores, Sebastián; Arredondo, Miguel

    2016-04-01

    Forty-five women (35-45 year) were randomly assigned to three iron (Fe) absorption sub-studies, which measured the effects of dietary animal proteins on the absorption of heme Fe. Study 1 was focused on heme, red blood cell concentrate (RBCC), hemoglobin (Hb), RBCC+beef meat; study 2 on heme, heme+fish, chicken, and beef; and study 3 on heme and heme+purified animal protein (casein, collagen, albumin). Study 1: the bioavailability of heme Fe from Hb was similar to heme only (∼13.0%). RBCC (25.0%) and RBCC+beef (21.3%) were found to be increased 2- and 1.6-fold, respectively, when compared with heme alone (p<0.05). Study 2: the bioavailability from heme alone (10.3%) was reduced (p<0.05) when it was blended with fish (7.1%) and chicken (4.9%), however it was unaffected by beef. Study 3: casein, collagen, and albumin did not affect the bioavailability of Fe. Proteins from animal source foods and their digestion products did not enhance heme Fe absorption. PMID:26593548

  12. Effects of Selenium on Thyroid Hormone Levels in Sheep

    OpenAIRE

    ATEŞŞAHİN, Ahmet; PİRİNÇCİ, İbrahim

    2002-01-01

    In this study, the thyroid hormone levels in sheep experimentally treated with selenium were investigated. Twelve Akkaraman sheep were used in the investigation. Selenium was given intramuscularly at doses of 0.1 (Group 1) and 0.4 mg/kg (Group 2). The blood samples were taken from the jugular vein at 1, 2, 4, 8, 24, 48, 96 and 144 hours after the administration. Serum triiodotyronine (T3), thyroxin (T4), free triiodotironine (fT3) and free thyroxin (fT4) levels were determined using a hormone...

  13. Theoretical predictions of arsenic and selenium species under atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Monahan-Pendergast, M.T.; Przybylek, M.; Lindblad, M.; Wilcox, J. [Worcester Polytechnic Institute, Worcester, MA (United States). Dept. of Chemical Engineering

    2008-03-15

    Thermochemical properties of arsenic and selenium species thought to be released into the atmosphere during the coal combustion were examined using ab initio methods. At various levels of theory, calculated geometries and vibrational frequencies of the species were compared with experimental data, where available. Through a comparison of equilibrium constants for a series of gaseous arsenic and selenium oxidation reactions involving OH and HO{sub 2}, five thermodynamically favored reactions were found. In addition, it was determined that all favored reactions were more likely to go to completion tinder tropospheric, rather than stratospheric, conditions.

  14. The content of selenium in some sulphide minerals of Karelia

    Directory of Open Access Journals (Sweden)

    Vapirov Vladimir

    2015-12-01

    Full Text Available Fluorimetric method was used to determine the content of selenium in various forms of pyrite and pyrrhotite in some iron- pyrite deposits of Karelia. In the studied deposits, the average content of selenium in all the sulfide minerals is 1,23•10-3 % ± 1,1•10-3 % and it is comparable with the data received in other pyrite deposits . In the natural conditions, environmental pollution from sulfide minerals is unlikely and possible only during field development.

  15. Environmental arsenic exposure, selenium and sputum alpha-1 antitrypsin

    DEFF Research Database (Denmark)

    Burgess, Jefferey L; Kurzius-Spencer, Margaret; Poplin, Gerald S;

    2014-01-01

    Exposure to arsenic in drinking water is associated with increased respiratory disease. Alpha-1 antitrypsin (AAT) protects the lung against tissue destruction. The objective of this study was to determine whether arsenic exposure is associated with changes in airway AAT concentration and whether...... selenium positively associated with sputum AAT (P=0.004 and P=0.002, respectively). In analyses stratified by town, these relationships remained significant only in Ajo, with the higher arsenic exposure. Reduction in AAT may be a means by which arsenic induces respiratory disease, and selenium may protect...

  16. A New Spectrophotometric Method for Determination of Selenium in Cosmetic and Pharmaceutical Preparations after Preconcentration with Cloud Point Extraction

    OpenAIRE

    Mohammad Hosein Soruraddin; Rouhollah Heydari; Morteza Puladvand; Mir Mehdi Zahedi

    2011-01-01

    A simple, rapid, and sensitive spectrophotometric method for the determination of trace amounts of selenium (IV) was described. In this method, all selenium spices reduced to selenium (IV) using 6 M HCl. Cloud point extraction was applied as a preconcentration method for spectrophotometric determination of selenium (IV) in aqueous solution. The proposed method is based on the complexation of Selenium (IV) with dithizone at pH 

  17. Are iron nanoparticles a potential source of bioavailable Fe to marine algae?

    Science.gov (United States)

    Shi, Zongbo; Pettitt, Michala

    2015-04-01

    Atmospheric Fe deposition has been suggested to affect biological productivity, not only in the Fe limited High Nutrient Low Chlorophyll (HNLC) regions, but also in the Tropical oligotrophic gyres. Therefore, it has direct and indirect impact on the climate. Atmospheric deposition provides soluble Fe as well as Fe nanoparticles. Our previous study confirmed the presence of Fe nanoparticles in rainwater, while another study by Aguilar-Islas et al. (2010) showed that Fe nanoparticles are the dominant fraction of aerosol derived dissolved Fe. It was generally accepted that soluble Fe is bioavailable. The question is: are Fe nanoparticles potential sources of bioavailable Fe to marine phytoplankton as well? In this study, we synthesized Fe nanoparticles in the laboratory. The Fe nanoparticles were coated with citrate to avoid particle aggregation. The freshly prepared Fe nanoparticles were cultured with Fe depleted Thalassiosira pseudonana diatom cells at a concentration of 10nM to 1000nM Fe. We also cultured the diatom cells with soluble Fe at the same Fe concentration. We found that chlorophyll a content in the Thalassiosira pseudonana diatom cells increase by over 50% and 150% after 4 days of culture with 100 nM and 1000 nM Fe nanoparticles. Surprisingly, soluble Fe at the same concentration had a similar impact on the chlorophyll a content in the Thalassiosira pseudonana diatom cells. This may be due to the fact that soluble Fe precipitated as nanoparticles at a high pH of the culture media (similar to real sea water pH). Similar process may take place during atmospheric deposition of soluble Fe. Our results suggest that both soluble and nanoparticles Fe in atmospheric depositions are potential source of bioavailable Fe to the marine phytoplankton. Further investigations on the bioavailability of soluble and nanoparticle Fe in the rainwater are underway.

  18. Sources and fate of bioavailable dissolved organic nitrogen in the Neuse River Estuary, North Carolina

    Science.gov (United States)

    Paerl, H. W.; Peierls, B. L.; Hounshell, A.; Osburn, C. L.

    2015-12-01

    Eutrophication is a widespread problem affecting the structure and function of estuaries and is often linked to anthropogenic nitrogen (N) enrichment, since N is the primary nutrient limiting algal production. Watershed management actions typically have ignored dissolved organic nitrogen (DON) loading because of its perceived refractory nature and instead focused on inorganic N as targets for loading reductions. A fluorescence-based model indicated that anthropogenic sources of DON near the head of the microtidal Neuse River Estuary (NRE), NC were dominated by septic systems and poultry waste. A series of bioassays were used to determine the bioavailability of river DON and DON-rich sources to primary producers and whether those additions promoted the growth of certain phytoplankton taxa, particularly harmful species. Overall, at time scales up to two to three weeks, estuarine phytoplankton and bacteria only showed limited responses to additions of high molecular weight (HMW, >1 kDa) river DON. When increases in productivity and biomass did occur, they were quite small compared with the response to inorganic N. Low molecular weight (LMW) river DON, waste water treatment plant effluent, and poultry litter extract did have a positive effect on phytoplankton and bacterial production, indicating a bioavailable fraction. High variability of bulk DON concentration suggested that bioavailable compounds added in the experimental treatments were low in concentration and turned over quite rapidly. Some phytoplankton taxa, as measured by diagnostic photopigments, appeared to be selectively enhanced by the HMW and specific source DON additions, although the taxa could not be positively identified as harmful species. Preliminary tests show that labile autochthonous organic matter may act as a primer for the mineralization of the HMW DON. These and other, longer-term bioavailability studies will be needed to adequately address the fate of watershed DON in estuarine ecosystems.

  19. [Distribution and bioavailability of nitrogen and phosphorus species in the urban dusts from Hefei City].

    Science.gov (United States)

    Li, Ru-Zhong; Zhou, Ai-Jia; Tong, Fang; Li, Feng; Qian, Jia-Zhong

    2012-04-01

    To find out the distribution and bioavailability of nitrogen (N) and phosphorus (P) species in the urban dusts of Hefei City, 52 samples were collected from impervious areas with six different urban land-use types. The contents of ammonia nitrogen (NH4(+) -N), nitrate nitrogen (NO3(-) -N), exchangeable P (Ex-P), Al-bound P (Al-P), Fe-bound P (Fe-P), occluded P (Oc-P), Ca-bound P (Ca-P), detrital apatite P (De-P), organic P (Or-P) as well as total nitrogen (TN) and total phosphorus (TP) were measured by sequential extraction methods. The studies on spatial distribution, correlation and bioavailability of nitrogen and phosphorus species were made according to the analyzed data. The results show that the TN is composed mainly of organic nitrogen (Or-N) while the TP consists chiefly of inorganic phosphorus (IP) in the urban dusts of Hefei City, and the spatial variability of nitrogen and phosphorus species contents are greatly affected by the mode of urban land-use type. In addition, there are significant correlations among partial nitrogen and phosphorus forms in dusts. Corresponding to different urban land-use types such as industrial area, commercial area, residential area, educational area, traffic area and public landscapes and city squares, the average ratios of bioavailable nitrogen content (the sum of NH4(+) -N and NO3(-) -N) to TN are 8.87%, 9.60%, 6.68%, 9.37%, 8.20% and 8.17%, respectively, while the mean ratios of bioavailable phosphorus content (the sum of Ex-P, Al-P and Fe-P) to TP, are equal to 6.70%, 18.19%, 10.10%, 9.69%, 10.64% and 14.03%, respectively. PMID:22720560

  20. Influence of dietary sodium selenite on tissue selenium levels of growing pigs

    International Nuclear Information System (INIS)

    Twenty Norwegian Landrace pigs were divided into 5 groups and fed a basal diet consisting of a mixture of dried skim milk and whey powder together with ground barley. The diet was supplemented with 0, 0.2, 0.8, 1.2, and 2.2 μg/g selenium as sodium selenite and was fed for 12 weeks. The muscle selenium level was increased by a factor of about 4 and the liver selenium by a factor of about 12 when the dietary selenium supplement was increased from zero to 2.2μg/g. There was a significant linear correlation between dietary selenium and selenium concentrations in tissues. Possible benefit for humans consuming meat from animals having received the selenium doses used in this experiment are discussed. (author)

  1. Effect of irradiation on sod activity and selenium content in garlic

    International Nuclear Information System (INIS)

    The effects of irradiation at 0.1 kGy, 1.0 kGy on SOD activity and the content of total selenium, inorganic selenium, organic selenium in garlic (Allium sativum L.) stored at 10 degree C or 25 degree C were investigated. The results indicated that irradiation treatment with 0.1 kGy, 1 kGy significantly slowed the reduction of SOD activities in garlic stored at 10 degree C or 25 degree C, while the treatment irradiation had no influence on the content of all kinds of selenium. But the garlic stored at 25 degree C had higher content of total selenium, inorganic selenium, organic selenium than that in garlic stored at 10 degree C. (authors)

  2. 21 CFR 320.30 - Inquiries regarding bioavailability and bioequivalence requirements and review of protocols by...

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Inquiries regarding bioavailability and... FOR HUMAN USE BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS Procedures for Determining the Bioavailability or Bioequivalence of Drug Products § 320.30 Inquiries regarding bioavailability and...

  3. Influence the oxidant action of selenium in radiosensitivity induction and cell death in yeast Saccharomyces cerevisiae; Influencia da acao oxidante do selenio na inducao da radiossensibilidade e morte celular na levedura Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Barbara Abranches de Araujo

    2012-07-01

    Ionizing radiations are from both natural sources such as from anthropogenic sources. Recently, radiotherapy has emerged as one of the most common therapies against cancer. Co-60 irradiators (cobalt-60 linear accelerators) are used to treat of malignant tumors routinely in hospitals around the world. Exposure to ionizing radiation can induce changes in cellular macromolecules and affect its functions, because they cause radiolysis of the water molecule generating reactive oxygen species, which can cause damage to virtually all organelles and cell components known as oxidative damage that can culminate in oxidative stress. Oxidative stress is a situation in which the balance between oxidants and antioxidants is broken resulting in excessive production of reactive species, it is not accompanied by the increase in antioxidant capacity, making it impossible to neutralize them. Selenium is a micronutrient considered as antioxidant, antiinflammatory, which could prevent cancer. Selenium in biological system exists as seleno proteins. Nowadays, 25 human seleno proteins have been identified, including glutathione peroxidase, an antioxidant enzyme. Yeasts have the ability to incorporate various metals such as iron, cadmium, zinc and selenium, as well as all biological organisms. The yeast Saccharomyces cerevisiae, unlike mammalian cells is devoid of seleno proteins, being considered as a practical model for studies on the toxicity of selenium, without any interference from the metabolism of seleno proteins. Moreover, yeast cells proliferate through the fermentation, the microbial equivalent of aerobic glycolysis in mammals and the process is also used by tumors. Several reports show that the pro-oxidante effects and induced toxic selenium compounds occur at lower doses and in malignant cells compared with benign cells. Therefore selenium giving a great therapeutic potential in cancer treatment .Our objective was to determine whether selenium is capable to sensitize yeasts

  4. Synergistic Effect of Selenium Addition and Water Stress on Melilotus officinalis L. Mineral Content

    Directory of Open Access Journals (Sweden)

    Panagiota KOSTOPOULOU

    2015-12-01

    Full Text Available The objective of this study was to examine the combined effects of selenium (Se enrichment and water stress on the accumulation of available macro- and micronutrients in Melilotus officinalis L. aerial parts. Plants of M. officinalis were subjected to three levels of Se addition (0, 1 and 3 mg Se L-1 water and to two water treatments: a full irrigation and b limited irrigation (water stress. The above ground biomass (stems and leaves was analyzed for Se, potassium (K, sodium (Na, magnesium (Mg, iron (Fe, copper (Cu, calcium (Ca, manganese (Mn and zinc (Zn. Se addition differentially affected the K, Mg and Ca content of M. officinalis aerial parts, while it led to the reduction of the micronutrients Cu, Fe and Mn. Water stress resulted in the increase of K, Na, Mg, Ca and Cu, and to the decrease of the Fe, Zn and Mn content. An interaction between selenium addition and water treatment was more notable for Ca and Mg, which decreased under water stress at low Se level and for Zn and Cu, which increased under water stress at high Se level. According to our findings, Se-induced increased accumulation of some inorganic ions in the aerial parts of this species under water stress conditions could serve as a means to alleviate the adverse impact of water deficit on important metabolic processes, enhancing M. officinalis tolerance to water stress.

  5. Absence of selenium protection against methylmercury toxicity in harbour seal leucocytes in vitro.

    Science.gov (United States)

    Das, Krishna; Dupont, Aurélie; De Pauw-Gillet, Marie-Claire; Debier, Cathy; Siebert, Ursula

    2016-07-15

    Previous studies described high concentrations of mercury (Hg) and selenium (Se) in the blood of harbour seals, Phoca vitulina from the North Sea. In the present study, we evaluated the in vitro potential protective effects of sodium selenite (Na2SeO3) and selenomethionine (SeMet) on cell proliferation of harbour seal lymphocytes exposed to MeHgCl 0.75μM. In vitro exposure of ConA-stimulated T lymphocytes resulted in severe inhibition of DNA synthesis, likely linked to severe loss of mitochondrial membrane potential at 0.75μM. Neither selenite nor SeMet showed a protective effect against MeHg toxicity expressed at the T lymphocyte proliferation level for harbour seals. Selenite and SeMet did not show negative effects regarding lymphocyte proliferation and mitochondrial membrane potential. To conclude, our results clearly demonstrated that MeHg affected in vitro immune cells exposure with no protective effects of selenium at a molar ratio Hg:Se of 1:10 in harbour seals from the North Sea. PMID:27197766

  6. The role of dietary selenium in bovine mammary gland health and immune function.

    Science.gov (United States)

    Salman, S; Khol-Parisini, A; Schafft, H; Lahrssen-Wiederholt, M; Hulan, H W; Dinse, D; Zentek, J

    2009-06-01

    Mastitis is not only a major cause of economic losses to the dairy industry but also a major problem in ensuring the quality and safety of the milk, associated with high somatic cell counts and residues of antibiotics used for treatment. One innovative approach to protection against mastitis is to stimulate the animal's natural defense mechanisms. Technological advances in immunological research have increased our ability to exploit the immunity of the bovine mammary gland during periods of high susceptibility to disease. The trace element selenium affects the innate and the adaptive immune responses of the mammary gland through cellular and humoral activities. Substantial research has been carried out on the effect of selenium (Se) on the immune function of the mammary gland and subsequent improvement in bovine udder health and mastitis control. Levels higher than current recommendations and Se-yeast can potentially be used to enhance our capacity to modulate the physiological mechanisms of the bovine mammary gland to respond to infection. This article provides an overview of the most recent research in this field. PMID:19195425

  7. The Effect on Selenium Concentrations of a Randomized Intervention with Fish and Mussels in a Population with Relatively Low Habitual Dietary Selenium Intake

    DEFF Research Database (Denmark)

    Outzen, Malene; Tjønneland, Anne; Larsen, Erik Huusfeldt;

    2015-01-01

    Selenium status of the Danish population is below that assumed optimal for the suggested protective effects against chronic diseases, including certain cancers. Fish and shellfish are important dietary sources of selenium in Denmark. We investigated the effect of increased fish and mussel intake on...... selenium blood concentrations in a population with relatively low habitual dietary selenium intake. We randomly assigned 102 healthy men and women (all non-smokers) aged 48-76 years to an intervention group (n = 51) or a control group (n = 51). Intervention participants received 1000 g fish and mussels...

  8. Bioavailability of Bacampicillin and Talampicillin, Two Oral Prodrugs of Ampicillin

    OpenAIRE

    Sjövall, Jan; Magni, Lennart; Vinnars, Erik

    1981-01-01

    A 200-mg amount of bacampicillin showed a significantly higher relative extent of bioavailability than did a 250-mg amount of talampicillin, possibly due to their different stability in the digestive juices.

  9. Recycling of high purity selenium from CIGS solar cell waste materials

    International Nuclear Information System (INIS)

    Highlights: • A new method for recycling of selenium from CIGS solar cell materials is presented. • Separation of selenium as selenium dioxide after heating in oxygen atmosphere. • Complete selenium separation after oxidation of <63 μm particles at 800 °C for 1 h. • After reduction of selenium dioxide the selenium purity was higher than 99.999 wt%. - Abstract: Copper indium gallium diselenide (CIGS) is a promising material in thin film solar cell production. To make CIGS solar cells more competitive, both economically and environmentally, in comparison to other energy sources, methods for recycling are needed. In addition to the generally high price of the material, significant amounts of the metals are lost in the manufacturing process. The feasibility of recycling selenium from CIGS through oxidation at elevated temperatures was therefore examined. During oxidation gaseous selenium dioxide was formed and could be separated from the other elements, which remained in solid state. Upon cooling, the selenium dioxide sublimes and can be collected as crystals. After oxidation for 1 h at 800 °C all of the selenium was separated from the CIGS material. Two different reduction methods for reduction of the selenium dioxide to selenium were tested. In the first reduction method an organic molecule was used as the reducing agent in a Riley reaction. In the second reduction method sulphur dioxide gas was used. Both methods resulted in high purity selenium. This proves that the studied selenium separation method could be the first step in a recycling process aimed at the complete separation and recovery of high purity elements from CIGS

  10. Comparison of standard and reaction cell inductively coupled plasma mass spectrometry in the determination of chromium and selenium species by HPLC-ICP-MS

    International Nuclear Information System (INIS)

    Elemental speciation is becoming a common analytical procedure for geochemical investigations. The various redox species of environmentally relevant metals can have vastly different biogeochemical properties, including sorption, solubility, bioavailability, and toxicity. The use of high performance liquid chromatography (HPLC) coupled to elemental specific detectors, such as inductively coupled plasma mass spectrometry (ICP-MS), has become one of the most important speciation methods employed. This is due to the separation versatility of HPLC and the sensitive and selective detection capabilities of ICP-MS. The current study compares standard mode ICP-MS to recently developed reaction cell (RC) ICP-MS, which has the ability to remove or reduce many common polyatomic interferences that can limit the ability of ICP-MS to quantitate certain analytes in complex matrices. Determination of chromium and selenium redox species is achieved using ion-exchange chromatography with elemental detection by standard and RC-ICP-MS, using various chromium and selenium isotopes. In this study, method performance and detection limits for the various permutations of the method (isotope monitored or ICP-MS detection mode) were found to be comparable and generally less than 1 μg L-1. The method was tested on synthetic laboratory samples, surface water, groundwater, and municipal tap water matrices

  11. Comparison of standard and reaction cell inductively coupled plasma mass spectrometry in the determination of chromium and selenium species by HPLC-ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Bednar, A.J. [U.S. Army Engineer Research and Development Center, Environmental Laboratory, 3909 Halls Ferry Rd., Vicksburg, MS 39180 (United States)], E-mail: Anthony.J.Bednar@erdc.usace.army.mil; Kirgan, R.A.; Jones, W.T. [U.S. Army Engineer Research and Development Center, Environmental Laboratory, 3909 Halls Ferry Rd., Vicksburg, MS 39180 (United States)

    2009-01-19

    Elemental speciation is becoming a common analytical procedure for geochemical investigations. The various redox species of environmentally relevant metals can have vastly different biogeochemical properties, including sorption, solubility, bioavailability, and toxicity. The use of high performance liquid chromatography (HPLC) coupled to elemental specific detectors, such as inductively coupled plasma mass spectrometry (ICP-MS), has become one of the most important speciation methods employed. This is due to the separation versatility of HPLC and the sensitive and selective detection capabilities of ICP-MS. The current study compares standard mode ICP-MS to recently developed reaction cell (RC) ICP-MS, which has the ability to remove or reduce many common polyatomic interferences that can limit the ability of ICP-MS to quantitate certain analytes in complex matrices. Determination of chromium and selenium redox species is achieved using ion-exchange chromatography with elemental detection by standard and RC-ICP-MS, using various chromium and selenium isotopes. In this study, method performance and detection limits for the various permutations of the method (isotope monitored or ICP-MS detection mode) were found to be comparable and generally less than 1 {mu}g L{sup -1}. The method was tested on synthetic laboratory samples, surface water, groundwater, and municipal tap water matrices.

  12. Selenium Speciation and Management in Wet FGD Systems

    Energy Technology Data Exchange (ETDEWEB)

    Searcy, K; Richardson, M; Blythe, G; Wallschlaeger, D; Chu, P; Dene, C

    2012-02-29

    This report discusses results from bench- and pilot-scale simulation tests conducted to determine the factors that impact selenium speciation and phase partitioning in wet FGD systems. The selenium chemistry in wet FGD systems is highly complex and not completely understood, thus extrapolation and scale-up of these results may be uncertain. Control of operating parameters and application of scrubber additives have successfully demonstrated the avoidance or decrease of selenite oxidation at the bench and pilot scale. Ongoing efforts to improve sample handling methods for selenium speciation measurements are also discussed. Bench-scale scrubber tests explored the impacts of oxidation air rate, trace metals, scrubber additives, and natural limestone on selenium speciation in synthetic and field-generated full-scale FGD liquors. The presence and concentration of redox-active chemical species as well as the oxidation air rate contribute to the oxidation-reduction potential (ORP) conditions in FGD scrubbers. Selenite oxidation to the undesirable selenate form increases with increasing ORP conditions, and decreases with decreasing ORP conditions. Solid-phase manganese [Mn(IV)] appeared to be the significant metal impacting the oxidation of selenite to selenate. Scrubber additives were tested for their ability to inhibit selenite oxidation. Although dibasic acid and other scrubber additives showed promise in early clear liquor (sodium based and without calcium solids) bench-scale tests, these additives did not show strong inhibition of selenite oxidation in tests with higher manganese concentrations and with slurries from full-scale wet FGD systems. In bench-tests with field liquors, addition of ferric chloride at a 250:1 iron-to-selenium mass ratio sorbed all incoming selenite to the solid phase, although addition of ferric salts had no impact on native selenate that already existed in the field slurry liquor sample. As ORP increases, selenite may oxidize to selenate more

  13. Bioaccessibility tests accurately estimate bioavailability of lead to quail

    Science.gov (United States)

    Beyer, W. Nelson; Basta, Nicholas T; Chaney, Rufus L.; Henry, Paula F.; Mosby, David; Rattner, Barnett A.; Scheckel, Kirk G.; Sprague, Dan; Weber, John

    2016-01-01

    Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, we measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from five Pb-contaminated Superfund sites had relative bioavailabilities from 33%-63%, with a mean of about 50%. Treatment of two of the soils with phosphorus significantly reduced the bioavailability of Pb. Bioaccessibility of Pb in the test soils was then measured in six in vitro tests and regressed on bioavailability. They were: the “Relative Bioavailability Leaching Procedure” (RBALP) at pH 1.5, the same test conducted at pH 2.5, the “Ohio State University In vitro Gastrointestinal” method (OSU IVG), the “Urban Soil Bioaccessible Lead Test”, the modified “Physiologically Based Extraction Test” and the “Waterfowl Physiologically Based Extraction Test.” All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the RBALP pH 2.5 and OSU IVG tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter (24%), or present as Pb sulfate (18%). Additional Pb was associated with P (chloropyromorphite, hydroxypyromorphite and tertiary Pb phosphate), and with Pb carbonates, leadhillite (a lead sulfate carbonate hydroxide), and Pb sulfide. The formation of chloropyromorphite reduced the bioavailability of Pb and the amendment of Pb-contaminated soils with P may be a thermodynamically favored means to sequester Pb.

  14. ENHANCED BIOAVAILABILITY OF DRUGS VIA INTRANASAL DRUG DELIVEY SYSTEM

    OpenAIRE

    kumar Brajesh; Shafat Kausar; Akhtar Ali; Prajapati S.K; Singh Devendra

    2012-01-01

    The aim of present investigation is to explain the enhancement of bioavailability of drug through intranasal drug delivery system. Intranasal Therapy has been an accepted form of treatment in the Ayurvedic system of Indian Medicine. Recently, it has been shown that many drugs have better bioavailability by nasal route than the oral route. This has been attributed to rich vasculature and a highly permeable structure of the nasal mucosa coupled with avoidance of hepatic first-pass elimination, ...

  15. Speciation dynamics and bioavailability of metals

    International Nuclear Information System (INIS)

    In this paper the equilibrium approach the so-called 'free-ion activity model' (FIAM) has been applied over and again in the interpretation of the bio-uptake of metals from complex media. One of the prerequisites of the FIAM is that the supply of the bioactive metal species, i.e. the free-ion, towards the surface of the organism is much faster than the actual bioconversion step. Only then will equilibrium between the different metal species in the medium be maintained at any point in space and time and hence will the bulk activity of the free-ion be maintained at the surface. However, there are numerous examples of metal bio-uptake from complex systems where the conversion rates cannot be understood in terms of the bioactive free-metal alone. In such cases it is mandatory that bio-inactive metal complexes contribute to the supply of metal to the bio-interface. Apparently, some complexes are able to dissociate at such a rate that the produced free-metal can significantly contribute to the metal flux towards the bio-surface. The mathematical characterization of the speciation dynamics and bioavailability of metals is discussed

  16. Bioavailability of caseinophosphopeptide-bound iron.

    Science.gov (United States)

    Ait-Oukhatar, Nabil; Peres, Jean Michel; Bouhallab, Said; Neuville, Dominique; Bureau, Francois; Bouvard, Gerard; Arhan, Pierre; Bougle, Dominique

    2002-10-01

    Iron deficiency, one of the main worldwide nutritional deficiencies, results from the low bioavailability of most dietary iron, including cow milk. Hydrolysis of the cow milk protein casein produces low molecular weight caseinophosphopeptides (CPPs). Binding of iron to CPPs keeps it soluble in the digestive tract and prevents the formation of high molecular weight ferric hydroxides, which are poorly absorbed. Previous experimental studies have shown that iron bound to the phosphopeptide containing the first 25 amino acids of beta-casein, or beta-CN (1-25), is well absorbed and corrects efficiently iron deficiency. We sought to assess in vivo iron absorption and uptake by tissues involved in iron metabolism and storage (liver, spleen, bone marrow), using radiolabeled iron. beta-CN (1-25)-Fe displayed better absorption and tissue uptake by the vascularized rat loop model compared with a control substance, ferric ascorbate. The metabolism of beta-CN (1-25)-Fe labeled with iron 59, added to cow milk, was also studied in young women. Although the absorption of beta-CN (1-25)-Fe was not significantly higher than that of ferrous sulfate, it displayed significantly higher tissue uptake. This increase was transient and had disappeared by the 14th day of the study, suggesting that iron was used for metabolic purposes. PMID:12389027

  17. Maltodextrin based proniosomes of nateglinide: bioavailability assessment.

    Science.gov (United States)

    Sahoo, Ranjan Ku; Biswas, Nikhil; Guha, Arijit; Kuotsu, Ketousetuo

    2014-08-01

    The present study delineates the fabrication of maltodextrin based proniosomes of nateglinide and their potential as controlled delivery system for diabetic therapy. New Zealand albino male rabbits have been used as animal model for in vivo study. To evaluate the bioavailability of nateglinide proniosome, a rapid, simple and sensitive HPLC method with photodiode array detection was developed and validated to determine nateglinide in rabbit plasma. Chromatographic separation was achieved by a reverse phase C18 column using a mixture of acetonitrile:methanol:10mM phosphate buffer (pH 3.5) in the ratio of 56:14:30 (%v/v) as the mobile phase at a flow rate of 1.0ml/min and quantified based on drug/IS peak area ratios. Gliclazide was used as the internal standard. The intra- and inter-day relative standard deviations of four tested concentrations were below 2%. The nateglinide proniosome formulation exhibited significantly higher plasma concentration than those of pure drug. The study revealed that the rate and extent of absorption of nateglinide from the proniosomal formulation was comparatively enhanced that of pure drug. Maltodextrin based proniosomes of nateglinide is not only simple and cost efficient delivery but also offers a useful and promising carrier for diabetic therapy through oral administration. PMID:24909314

  18. Bioavailability of genotoxic mixtures in soil

    Energy Technology Data Exchange (ETDEWEB)

    Bordelon, N.; Washburn, K.; He, L.Y.; Donnelly, K.C. [Texas A and M Univ., College Station, TX (United States). Dept. of Veterinary Anatomy and Public Health

    1996-12-31

    Contaminated media at Superfund sites typically consist of complex mixtures of organic and inorganic chemicals which are difficult to characterize, both analytically and toxicologically. The current EPA approach to risk assessment uses solvent extraction to remove chemicals from the soil as a basis for estimating risk to the human population. However, contaminants that can be recovered with a solvent extract may not represent the mixture of chemicals that are available for human exposure. A procedure using an aqueous extraction was investigated to provide a more realistic estimate of what chemicals are bioavailable. A study was conducted with two soil types: creosote-contaminated sandy soil and coal tar-contaminated clay soil spiked with benzo(a)pyrene [B(a)P], and trinitrotoluene (TNT). Samples were extracted with hexane:acetone and water titrated to pH2 and pH7. HPLC analysis demonstrated up to 35% and 29% recovery of contaminants using the aqueous extracts. The estimated cancer risk for the aqueous extract was one order of magnitude less than that for solvent extracts. Analysis using the Salmonella/microsome assay demonstrated that solvent extracts were genotoxic (133 revertants/mg) with metabolic activation while aqueous extracts of clay soil were not genotoxic. Sandy soil showed genotoxicity both with and without metabolic activation. These results suggest that solvent extraction techniques may overestimate the concentration of contaminants that are available for human exposure and, hence, the risk associated with the presence of the contaminants in soil.

  19. Bioaccumulation and bioavailability of polybrominated diphynel ethers (PBDEs) in soil

    International Nuclear Information System (INIS)

    Earthworms were exposed to artificially contaminated soils of DE-71 and DE-79 to investigate the bioaccumulation and bioavailability of PBDEs in soil. All major congeners were bioavailable to earthworms. The uptake and elimination rate coefficients of PBDEs decreased with their logKows. The biota soil accumulation factors of PBDEs also declined with logKow. These may be due to the large molecular size and the high affinity of PBDEs to soil particles. The concentrations extracted by Tenax for 6 h correlated very well with those found in earthworms, suggesting that the bioavailability of PBDEs in soil is related to the fraction of rapid desorption from soil. This also indicates that 6 h Tenax extraction is a good proxy for the bioavailability of PBDEs to earthworms in soil. The BSAFs of PBDEs in aged soil decreased 22-84% compared to freshly spiked soil, indicating that aging may diminish the bioavailability of PBDEs in soil significantly. - PBDEs are bioavailable to earthworms in soil and the uptake and elimination rate coefficients and BSAFs declined with their logKows.

  20. Trace metal speciation and bioavailability in anaerobic digestion: A review.

    Science.gov (United States)

    Thanh, Pham Minh; Ketheesan, Balachandran; Yan, Zhou; Stuckey, David

    2016-01-01

    Trace metals are essential for the growth of anaerobic microorganisms, however, in practice they are often added to anaerobic digesters in excessive amounts, which can lead to inhibition. The concept of bioavailability of metals in anaerobic digestion has been poorly understood in the past, and a lack of deep understanding of the relationship between trace metal speciation and bioavailability can result in ineffective metal dosing strategies for anaerobic digesters. Sequential extraction schemes are useful for fractionating trace metals into their different forms, and metal sulfides can serve as a store and source for trace metals during anaerobic digestion, while natural/synthetic chelating agents (soluble microbial products-SMPs, extracellular polysaccharides-EPS, and EDTA/NTA) are capable of controlling trace metal bioavailability. Nevertheless, more work is needed to: investigate the speciation and bioavailability of Ca, Mg, Mn, W, and Se; compare the bioavailability of different forms of trace metals e.g. carbonates, sulfides, phosphates to different anaerobic trophic groups; determine what factors influence metal sulfide dissolution; investigate whether chelating agents can increase trace metal bioavailability; develop and adapt specialized analytical techniques, and; determine how trace metal dynamics change in an anaerobic membrane bioreactor (AnMBR). PMID:26707985

  1. Bioavailability enhancement of atovaquone using hot melt extrusion technology.

    Science.gov (United States)

    Kate, Laxman; Gokarna, Vinod; Borhade, Vivek; Prabhu, Priyanka; Deshpande, Vinita; Pathak, Sulabha; Sharma, Shobhona; Patravale, Vandana

    2016-04-30

    Emerging parasite resistance and poor oral bioavailability of anti-malarials are the two cardinal issues which hinder the clinical success of malaria chemotherapy. Atovaquone-Proguanil is a WHO approved fixed dose combination used to tackle the problem of emerging resistance. However, Atovaquone is a highly lipophilic drug having poor aqueous solubility (less than 0.2μg/ml) thus reducing its oral bioavailability. The aim of the present investigation was to explore hot melt extrusion (HME) as a solvent-free technique to enhance solubility and oral bioavailability of Atovaquone and to develop an oral dosage form for Atovaquone-Proguanil combination. Solid dispersion of Atovaquone was successfully developed using HME. The solid dispersion was characterized for DSC, FTIR, XRD, SEM, and flow properties. It was filled in size 2 hard gelatin capsules. The formulation showed better release as compared to Malarone® tablets, and 3.2-fold and 4.6-fold higher bioavailability as compared to Malarone® tablets and Atovaquone respectively. The enhanced bioavailability also resulted in 100% anti-malarial activity in murine infection model at 1/8(th) therapeutic dose. Thus the developed methodology shows promising potential to solve the problems associated with Atovaquone therapy, namely its high cost and poor oral bioavailability, resulting in increased therapeutic efficacy of Atovaquone. PMID:26969110

  2. Current mass spectrometry strategies for selenium speciation in dietary sources of high-selenium

    Energy Technology Data Exchange (ETDEWEB)

    Infante, Heidi Goenaga; Hearn, Ruth; Catterick, Tim [LGC Limited, Teddington, Middlesex (United Kingdom)

    2005-06-01

    This document reviews the most relevant mass spectrometry approaches to selenium (Se) speciation in high-Se food supplements in terms of qualitative and quantitative Se speciation and Se-containing species identification, with special reference to high-Se yeast, garlic, onions and Brazil nuts. Important topics such as complexity of Se speciation in these materials and the importance of combining Se-specific detection and molecule-specific determination of the particular species of this element in parallel with chromatography, to understand their nutritional role and cancer preventive properties are critically discussed throughout. The versatility and potential of mass spectrometric detection in this field are clearly demonstrated. Although great advances have been achieved, further developments are required, especially if ''speciated''certified reference materials (CRMs) are to be produced for validation of measurements of target Se-containing species in Se-food supplements. (orig.)

  3. Selenium in Paleozoic stone coal (carbonaceous shale) as a significant source of environmental contamination in rural southern China

    Science.gov (United States)

    Belkin, H. E.; Luo, K.

    2012-04-01

    Selenium occurs in high concentrations (typically > 10 and up to 700 ppm) in organic-rich Paleozoic shales and cherts (called "stone coal" - shíméi), in southern China. Stone coals are black shales that formed in anoxic to euxinic environments and typically contain high concentrations of organic carbon, are enriched in various metals such as V, Mo, Pb, As, Cr, Ni, Se, etc., and are distinguished from "humic" coal in the Chinese literature. We have examined stone coal from Shaanxi, Hubei, and Guizhou Provinces, People's Republic of China and have focused our study on the mode of occurrence of Se and other elements (e.g. As, Pb, etc.) hazardous to human health. Scanning electron microscope, energy-dispersive analysis and electron microprobe wave-length dispersive spectroscopy were used to identify and determine the composition of host phases observed in the stone coals. Native selenium, Se-bearing pyrite and other sulfides are the hosts for Se, although we cannot preclude an organic or clay-mineral association. Stone coals are an important source of fuel (reserves over 1 billion tonnes), both domestically and in small industry, in some rural parts of southern China and present significant environmental problems for the indigenous population. The stone coals create three main environmental problems related to Se pollution. First, the residual soils formed on stone coal are enriched in Se and other metals contained in the stone coals and, depending on the speciation and bioavailability of the metals, may enrich crops and vegetation grown on them. Second, weathering and leaching of the stone coal contaminates the local ground water and/or surface waters with Se and other metals. Third, the local population uses the stone coal as a source of fuel, which releases the more volatile elements (Se and As) into the atmosphere in the homes. The ash will be extremely enriched with the balance of the heavy metal suite. Disposal of the ash on agricultural lands or near water

  4. Novel selenium-doped hydroxyapatite coatings for biomedical applications.

    Science.gov (United States)

    Rodríguez-Valencia, C; López-Álvarez, M; Cochón-Cores, B; Pereiro, I; Serra, J; González, P

    2013-03-01

    Nowadays there is a short-term need of investigating in orthopedic implants with a greater functionality, including an improved osseointegration and also antibacterial properties. The coating of metallic implants with hydroxyapatite (HA) remains to be the main proposal, but superior quality HA coatings with compositions closer to natural bone apatites, including carbonates, trace elements are required. Selenium is an essential nutrient in biological tissues and, at the same time, it also presents antibacterial properties. A pioneering study on the fabrication of selenium-doped carbonated hydroxyapatite (iHA:Se) coatings by Pulsed Laser Deposition (PLD) is presented. Different proportions of selenium were incorporated to obtain the iHA:Se coatings. Their physicochemical characterization, performed by SEM/EDS, FTIR, FT-Raman, Interferometric Profilometry and XPS, revealed typical columnar growth of HA in globular aggregates and the efficient incorporation of selenium into the HA coatings by the, most probably, substitution of SeO(3)(2-) groups in the CO(3)(2-) sites. Biological evaluation illustrated the absence of cytotoxicity when an amount of 0.6 at.% of Se was added to the iHA:Se coatings and excellent proliferation of the MC3T3-E1 preosteoblasts. Antibacterial properties were also proved with the inhibition of P. aeruginosa and S. aureus from establishing bacterial biofilms. PMID:22968925

  5. Selenium and the regulation of cell cycle and apoptosis

    Science.gov (United States)

    Selenium was discovered by Berzelius in 1817, and the essentiality of Se was demonstrated that trace amounts of Se protected against liver necrosis in vitamin E deficient rats in the mid-1950s. The benefits of Se are many including protection against cancer, heart diseases, muscle disorders, immunit...

  6. Selenium adsorption to aluminum-based water treatment residuals

    Science.gov (United States)

    Aluminum-based water treatment residuals (WTR) can adsorb water- and soil-borne P, As(V), As(III), and perchlorate, and may be able to adsorb excess environmental selenium. WTR, clay minerals, and amorphous aluminum hydroxide were shaken for 24 hours in selenate or selenite solutions at pH values o...

  7. Comparison of Selenium Treatments of Crops in the Field

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel

    1986-01-01

    Field experiments with spring and winter barley and ryegrass were carried out to compare the effect of fertilizers enriched with selenate or selenite with foliar application on the selenium (Se) concentrations in the crops. Application of about 20 g Se/ha given as selenate or about 100 g as...

  8. A role for p53 in selenium-induced senescence

    Science.gov (United States)

    The tumor suppressor p53 and the ataxia-telangiectasia mutated (ATM) kinase play important roles in the senescence response to oncogene activation and DNA damage. We have previously shown that selenium-containing compounds can activate an ATM-dependent senescence response in MRC-5 normal fibroblasts...

  9. Kinetic spectrophotometric determination of trace amounts of selenium and vanadium

    Energy Technology Data Exchange (ETDEWEB)

    Safavi, A.; Sedghy, H.R.; Shams, E. [Dept. of Chemistry, Shiraz Univ. (Iran)

    1999-11-01

    A sensitive kinetic spectrophotometric method has been developed for the determination of Se(IV) over the range of 45 to 4000 ng in 10 mL of solution. The method is based on the catalytic effect of Se(IV) on the reduction reaction of bromate by hydrazinium dichloride, with subsequent reaction of Ponceau S with products of the above reaction (chlorine and bromine), causing color changing of Ponceau S. Method development includes optimization of time interval for measurement of slope, pH, reagents concentration, and temperature. The optimized conditions yielded a theoretical detection limit of 33 ng/10 mL of solution of Se(IV). The interfering effects were studied and removed. The method was applied to the determination of selenium in spiked water, Kjeldahl tablet, selenium tablet, and shampoo. Vanadium(V) has an inhibition effect on the catalyzed reaction of bromate and hydrazine by selenium. Using this effect, V(V) can be determined in the range of 70 to 2500 ng in 10 mL of solution. The optimization procedure includes pH and selenium concentration. An extraction method was used for interference removal. The method was applied to the determination of vanadium in petroleum. (orig.)

  10. Conditional effect of selenium on the mammalian hind gut microbiota

    Science.gov (United States)

    Selenium (Se) status is linked to cancer risk in humans and other mammals. Because Se is used by certain microbial species which contain selenoproteins, and because hind gut microfloral composition is linked to cancer development, we proposed that supranutritional Se could reduce tumorigenisis by af...

  11. Selenium speciation and extractability in Dutch agricultural soils

    NARCIS (Netherlands)

    Supriatin, Supriatin; Weng, Liping; Comans, Rob N.J.

    2015-01-01

    The study aimed to understand selenium (Se) speciation and extractability in Dutch agricultural soils. Top soil samples were taken from 42 grassland fields and 41 arable land fields in the Netherlands. Total Se contents measured in aqua regia were between 0.12 and 1.97mgkg-1(on average

  12. Discovery of Zinc, Selenium, Bromine, and Neodymium Isotopes

    OpenAIRE

    J.L. Gross; Claes, J.; Kathawa, J.; Thoennessen, M

    2010-01-01

    Currently, thirty-two zinc, thirty-two selenium, twenty-nine bromine and thirty-one neodymium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  13. Selenium mass balance in the Great Salt Lake, Utah

    Science.gov (United States)

    Diaz, X.; Johnson, W.P.; Naftz, D.L.

    2009-01-01

    A mass balance for Se in the south arm of the Great Salt Lake was developed for September 2006 to August 2007 of monitoring for Se loads and removal flows. The combined removal flows (sedimentation and volatilization) totaled to a geometric mean value of 2079??kg Se/yr, with the estimated low value being 1255??kg Se/yr, and an estimated high value of 3143??kg Se/yr at the 68% confidence level. The total (particulates + dissolved) loads (via runoff) were about 1560??kg Se/yr, for which the error is expected to be ?? 15% for the measured loads. Comparison of volatilization to sedimentation flux demonstrates that volatilization rather than sedimentation is likely the major mechanism of selenium removal from the Great Salt Lake. The measured loss flows balance (within the range of uncertainties), and possibly surpass, the measured annual loads. Concentration histories were modeled using a simple mass balance, which indicated that no significant change in Se concentration was expected during the period of study. Surprisingly, the measured total Se concentration increased during the period of the study, indicating that the removal processes operate at their low estimated rates, and/or there are unmeasured selenium loads entering the lake. The selenium concentration trajectories were compared to those of other trace metals to assess the significance of selenium concentration trends. ?? 2008 Elsevier B.V.

  14. Discovery of zinc, selenium, bromine, and neodymium isotopes

    International Nuclear Information System (INIS)

    Currently, thirty-two zinc, thirty-two selenium, twenty-nine bromine, and thirty-one neodymium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  15. JV Task 96 - Phase 2 - Investigating the Importance of the Mercury-Selenium Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas Ralston; Laura Raymond

    2008-03-01

    In order to improve the understanding of the mercury issue, it is vital to study mercury's effects on selenium physiology. While mercury present in the environment or food sources may pose health risks, the protective effects of selenium have not been adequately considered in establishing regulatory policy. Numerous studies report that vulnerability to mercury toxicity is inversely proportional to selenium status or level. However, selenium status has not been considered in the development of the reference dosage levels for mercury exposure. Experimental animals fed low-selenium diets are far more vulnerable to mercury toxicity than animals fed normal selenium, and animals fed selenium-rich diets are even more resistant. Selenium-dependent enzymes in brain and endocrine tissues can be impaired by excessive mercury exposure, apparently because mercury has an extremely high binding affinity for selenium. When selenium becomes bound to mercury, it is unable to participate in the metabolic cycling of selenoprotein synthesis. Because of mercury-dependent impairments of selenoprotein synthesis, various antioxidant and regulatory functions in brain biochemistry are compromised. This report details a 2-year multiclient-funded research program designed to examine the interactions between mercury and selenium in animal models. The studies explored the effects of dietary intakes of toxic amounts of methylmercury and the protective effects of the normal dietary range of selenium in counteracting mercury toxicity. This study finds that the amounts of selenium present in ocean fish are sufficient to protect against far larger quantities of methylmercury than those present in typical seafoods. Toxic effects of methylmercury exposure were not directly proportional to mercury concentrations in blood, brain, or any other tissues. Instead, mercury toxicity was proportional to molar ratios of mercury relative to selenium. In order to accurately assess risk associated with

  16. Biomagnification of mercury and selenium in two lakes in southern Norway.

    Science.gov (United States)

    Økelsrud, Asle; Lydersen, Espen; Fjeld, Eirik

    2016-10-01

    We have investigated bioaccumulation and trophic transfer of both mercury (Hg) and selenium (Se) in two lakes in southern Norway to reveal a suggested mitigating effect of Se on Hg biota accumulation. The study included analysis of total Se (Se), total Hg (Hg), and methyl-mercury (MeHg) in water, littoral and pelagic invertebrates and perch (Perca fluviatilis), together with stable isotope analysis (δ(15)N and δ(13)C) in biota. Mean dissolved Se ranged from 22 to 59ngL(-1), while Hg and MeHg in lake water ranged from 1 to 3ngL(-1) and 0.01 to 0.06ngL(-1). Biota Se and Hg concentrations (dry weight) ranged from 0.41mgSekg(-1) and 0.06mgHgkg(-1) in primary littoral invertebrates and up to 2.9mg Sekg(-1) and 3.6mgHgkg(-1) in perch. Both Hg and Se biomagnified in the food web, with a trophic magnification factor (TMF) of 4.64 for Hg and 1.29 for Se. The reported positive transfer of Se in the food web, despite the low measured dissolved Se, suggest that a major proportion of the Se in these lakes are both highly bioavailable and bioaccumulative. However, we did not find support for a Se-facilitated inhibition in the accumulation of Hg in perch, as Se and Hg concentrations in perch muscle correlated positively and Se did not explain any variations in Hg after we controlled for the effects of other important covariates. We postulate that this may be a result of insufficient concentrations of dissolved Se and subsequently in biota in our studied lakes for an efficient Hg sequestration up the food web. PMID:27236625

  17. Bioaccumulation of Selenium by the Bryophyte Hygrohypnum ochraceum in the Fountain Creek Watershed, Colorado

    Science.gov (United States)

    Herrmann, S. J.; Turner, J. A.; Carsella, J. S.; Lehmpuhl, D. W.; Nimmo, D. R.

    2012-12-01

    Aquatic bryophytes, Hygrohypnum ochraceum, were deployed "in situ" at 14 sites in the Fountain Creek Watershed, spring and fall, 2007 to study selenium (Se) accumulation. Dissolved, total, and pore (sediment derived) water samples were collected and water quality parameters determined while plants were exposed to the water for 10 days. There was a trend showing plant tissue-Se uptake with distance downstream and we found a strong correlation between Se in the water with total hardness in both seasons. There was a modest association between Se-uptake in plants with hardness in the spring of 2007 but not the fall. Plants bioconcentrated Se from the water by a factor of 5.8 × 103 at Green Mountain Falls and 1.5 × 104 at Manitou Springs in the fall of 2007. Both are examples of the bioconcentration abilities of the plants, primarily in the upper reaches of the watershed where bioconcentration factors were highest. However, the mean minima and maxima of Se in the plants in each of the three watershed segments appeared similar during both seasons. We found direct relationships between the pore and dissolved Se in water in the spring ( R 2 = 0.84) and fall ( R 2 = 0.95) and dissolved Se and total hardness in the spring and fall ( R 2 = 0.92). The data indicate that H. ochraceum was a suitable indicator of Se bioavailability and Se uptake in other trophic levels in the Fountain Creek Watershed based on a subsequent study of Se accumulation in fish tissues at all 14 sites.

  18. Poor oral bioavailability of a promising anticancer agent andrographolide is due to extensive metabolism and efflux by P-glycoprotein.

    Science.gov (United States)

    Ye, Ling; Wang, Tao; Tang, Lan; Liu, Wei; Yang, Zhen; Zhou, Juan; Zheng, Zhijie; Cai, Zheng; Hu, Ming; Liu, Zhongqiu

    2011-11-01

    Andrographolide (AP), isolated from Andrographis paniculata (Burm. F.) Nees, is an anticancer agent with significant clinical potential. This study determined its oral bioavailability and how intestinal disposition affects its bioavailability. Pharmacokinetics was evaluated in rats. Intestinal disposition was determined using a single-pass rat intestinal perfusion model and the cultured Caco-2 cells and Madin-Darby canine kidney II cells over expressing human P-gp (MDR1-MDCKII). Absolute bioavailability of AP was 2.67%. In the duodenum and jejunum, AP was rapidly metabolized to a sulfonate, identified as 14-deoxy-12-sulfo- andrographolide. AP was also rapidly metabolized by liver S9 fraction and in blank perfusates collected from duodenum and jejunum. The apparent permeability (P(app) ) of AP from basolateral (B) to apical (A) (4.94 × 10 cm/s) in the Caco-2 model was four times higher than the P(app) from A to B (1.14 × 10(-5) cm/s). Moreover, AP was significantly more permeable in the B to A direction than the opposite direction in MDR1-MDCKII cells. In the perfusion model, the effective permeability (P*(eff) ) for AP was highest in the duodenum, followed by jejunum, and then ileum and colon. In the ileum and colon, the P*(eff) for AP was significantly increased by verapamil, a P-glycoprotein (P-gp) inhibitor. AP has poor oral bioavailability because of its rapid biotransformation and efflux by P-gp. PMID:21721007

  19. Uptake, distribution, and turnover rates of selenium in barley.

    Science.gov (United States)

    Huang, K X; Clausen, J

    1994-03-01

    The present communication elucidates initially the topographic distribution of selenium in barley grains. Then by the fluorimetric method the uptake of selenium (selenite) in 8-16 d old germinating barley was estimated. Finally by means of 75Se the anabolic and catabolic rates (turnover) of 75Se (selenite) was compared. The distribution of selenium in barley was evaluated after micro-dissection of barley grains. In dried grains the highest concentration was found in husk and pericarp with about 0.6 ppm Se. Then followed Scutellum with 0.4 and 0.3 ppm in embryon. The aleurone layer, embryonic leaves, and initial root did only have 0.2 ppm Se. In order to know more about the uptake and distribution of selenium in 8-d-old barley, the plants were cultivated for a further 8 d in the culture medium with variation in selenite concentration. In roots and leaves, the uptake did not arrive at saturation during the period studied since the dose-response curve increased up to 0.34 mM selenite in the medium, whereas the selenium levels were about 200 ppm in roots and 30 ppm in leaves. However, the uptake was linear, with concentration during 8 d of cultivation up to 0.84 microM selenite for grain and stem. At higher concentrations the dose-response curve diminished its slope. At 0.34 mM selenite the concentration in grain increased to 6.87 ppm and in the stem to 8.13 ppm. The uptake, distribution, and catabolic rate of selenium components in germinating barley were further evaluated by exposing the plants to 0.0492 microCi 75Se (12.6 microM selenite) for up to 4 d. Then the plants were moved to a selenium deficient medium for further 4 d. Then finally the medium was supplemented with high doses of cold selenite (0.126 mM selenite) for further 4 d. The first third period made it possible to estimate the rate of uptake. It was highest in roots (313 fmol/h/mg dw), i.e., about 10 times those of grains, stems, and leaves. The intermediate period where the barley was transferred to a

  20. Phytoremediation of selenium-contaminated soils and waters: fundamentals and future prospects.

    Science.gov (United States)

    Bañuelos, G S; Lin, Z Q; Wu, L; Terry, N

    2002-01-01

    Interest in selenium pollution and remediation technology has escalated during the past two decades. Although not known to be essential for plants, selenium is an essential micronutrient for humans and animals, having important benefits for their nutrition. At high concentrations, however, selenium becomes toxic to animals and humans. A major selenium controversy in the 1980s emerged in California at the Kesterson National Wildlife Refuge; hence, scientists, environmental regulators, politicians, and the general public in the United States became aware of selenium's potential as an environmental contaminant. Consequently, extensive research has been conducted in the western United States, and a vast amount of financial resources have been allocated to develop management strategies and remediation technologies for reducing the impact of naturally occurring selenium on the biological environment. A plant-based technology, defined as 'phytoremediation', has received increasing recognition as a low-cost, environmentally friendly approach for managing the toxic effects of selenium. Plants have the ability to absorb and sequester selenium and to convert inorganic selenium to volatile forms of organic compounds that are released harmlessly into the atmosphere. The present review summarizes recent research findings and information about strategies on using phytoremediation systems to detoxify selenium-contaminated soils and waters in natural and agricultural ecosystems. PMID:12611471

  1. Selenium Accumulating Leafy Vegetables Are a Potential Source of Functional Foods.

    Science.gov (United States)

    Mabeyo, Petro E; Manoko, Mkabwa L K; Gruhonjic, Amra; Fitzpatrick, Paul A; Landberg, Göran; Erdélyi, Máté; Nyandoro, Stephen S

    2015-01-01

    Selenium deficiency in humans has been associated with various diseases, the risks of which can be reduced through dietary supplementation. Selenium accumulating plants may provide a beneficial nutrient for avoiding such illnesses. Thus, leafy vegetables such as Amaranthus hybridus, Amaranthus sp., Cucurbita maxima, Ipomoea batatas, Solanum villosum, Solanum scabrum, and Vigna unguiculata were explored for their capabilities to accumulate selenium when grown on selenium enriched soil and for use as a potential source of selenium enriched functional foods. Their selenium contents were determined by spectrophotometry using the complex of 3,3'-diaminobenzidine hydrochloride (DABH) as a chromogen. The mean concentrations in the leaves were found to range from 7.90 ± 0.40 to 1.95 ± 0.12 μg/g dry weight (DW), with C. maxima accumulating the most selenium. In stems, the accumulated selenium content ranged from 1.12 ± 0.10 μg/g in Amaranthus sp. to 5.35 ± 0.78 μg/g DW in C. maxima and was hence significantly different (P < 0.01). The cancer cell line MDA-MB-231 was used in cytotoxicity assays to determine the anticancer potential of these extracts. With exception of S. scabrum and S. villosum, no cytotoxicity was detected for the selenium enriched vegetable extracts up to 100 μg/mL concentration. Hence, following careful evaluation the studied vegetables may be considered as selenium enriched functional foods. PMID:26955635

  2. Novel approaches for selenium speciation in foodstuffs and biological specimens: A review

    International Nuclear Information System (INIS)

    Selenium is an essential element for human health. It has been recognized as an antioxidant and chemopreventive agent in cancer. Selenium is known to develop its biological activity via selenocysteine residue in the catalytically active centre of selenoproteins. The main source of selenium in human beings is the diet. However, in several regions of the world the content of selenium in diet has been estimated insufficient for a correct expression of the proteins. The beneficial effects of selenium on human health are strongly dependent on its chemical form and concentration. This review critically evaluated the state-of-the art of selenium speciation in biological matrices mainly focused in nutritional and food products. Besides the number of publications related to selenium speciation, isolation and accurate characterization and quantification of selenium species is still a challenge. Hyphenated techniques based on coupling chromatography separation with inductively coupled plasma spectrometry (ICP-MS) and its combination with molecular mass spectrometry (ESI-MS, ESI-MS-MS and MALDI-TOF) and isotopic dilution allow identification, quantification and structural characterization of selenium species. Particular attention is paid in the development of Se-enriched food and nutritional products and how the application of the techniques mentioned above is mandatory to get reliable results on selenium metabolisms in these particular matrices

  3. Assessment of selenium pollution in agricultural soils in the Xuzhou District, Northwest Jiangsu, China

    Institute of Scientific and Technical Information of China (English)

    HUANG Shunsheng; HUA Ming; FENG Jinshun; ZHONG Xinyong; JIN Yang; ZHU Baiwan; LU Hua

    2009-01-01

    Xuzhou City is an important base for coal production and coal-fired power. To evaluate selenium contamination in this area, we sampled agricultural soil, soil profile, irrigation water, bedrock, coal, fly ash, paddy rice, and vegetables from the north of Xuzhou City, and determined their selenium contents. The background level of selenium in the soil profile was 0.08 mg/kg. The selenium concentrations in agricultural soils and irrigation water were in the range of 0.21-4.08 mg/kg and 0.002-0.29 mg/L, respectively. Soils with high selenium contents were located close to coalmines and power plants. The average selenium concentrations in coal and coal fly ash were 5.46 and 2.81 mg/kg, respectively. In contrast, the concentrations of selenium in bedrock and in the soil profile were very low. These results imply that the high selenium level in agricultural soils is mainly caused by anthropogenic activities, rather than by parent material. The arithmetic mean of selenium concentration in paddy rice was 0.116 mg/kg, and in cabbage was 0.05 mg/kg, which exceed the national limits for foodstuffs. The selenium concentration in rice was positively correlated with total selenium concentration in soil, suggesting that selenium in soil is readily transferred into the crops. Furthermore, the estimated dietary intake (88.8 μg) of selenium from paddy rice and cabbage exceeds the recommended dietary allowance (55 μg). Therefore, there is a potential health risk from consumption of local staple food in the study area.

  4. Buccal films of prednisolone with enhanced bioavailability.

    Science.gov (United States)

    Kumria, Rachna; Nair, Anroop B; Goomber, Garima; Gupta, Sumeet

    2016-01-01

    The conventional formulation of prednisolone is considered to be low in efficacy, primarily on account of their failure in providing and maintaining effective therapeutic drug levels. This study aims to focus on development of a mucoadhesive buccal delivery system with a twofold objective of offering a rapid as well as a prolonged delivery of prednisolone coupled with enhanced therapeutic efficacy. Buccoadhesive films of prednisolone were prepared by solvent-casting method using hydroxyl propyl methyl cellulose (K100), Carbopol 940 and/or Eudragit NE 40 D. Placebo films possessing the most desirable physicomechanical properties were selected for drug loading. The effect of polymer and its content on film properties, i.e. mucoadhesive strength, swelling and hydration, in vitro drug release was studied. Based on these studies, film F7D was selected for ex vivo permeation across porcine cheek mucosa. The steady state flux of prednisolone across the buccal mucosa was found to be 105.33 ± 32.07 µg/cm(2)/h. A comparative pharmacokinetic study of prepared film (F7D) and oral suspension of prednisolone was conducted. In vivo data of buccal film show greater bioavailability (AUC0-α: 24.26 ± 4.06 µg.h/ml versus 10.65 ± 2.15 µg.h/ml) and higher Cmax (2.70 ± 0.38 µg/ml versus 2.29 ± 0.32 µg/ml) value when compared to oral suspension. The data observed from this study highlight the feasibility of the buccal route as a viable option for delivery of prednisolone. PMID:24892626

  5. SPECIATION OF SELENIUM(IV) AND SELENIUM(VI) USING COUPLED ION CHROMATOGRAPHY: HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROMETRY

    Science.gov (United States)

    A simple method was developed to speciate inorganic selenium in the microgram per liter range using coupled ion chromatography-hydride generation atomic absorption spectrometry. Because of the differences in toxicity and adsorption behavior, determination of the redox states selenite, Se(IV), and s...

  6. Facile synthesis of hollow carbonized polyaniline spheres to encapsulate selenium for advanced rechargeable lithium–selenium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jie; Zhao, Xingxing; Zhang, Zhian; Lai, Yanqing

    2015-01-15

    Highlights: • Hollow carbonized polyaniline spheres was prepared by a simple copper(II)-catalyzed self-assembly method. • Hollow carbonized polyaniline spheres can effectively constrain the selenium and polyselenides. • The hollow carbonized polyaniline spheres/selenium composite cathode exhibits excellent electrochemical properties. - Abstract: A hollow carbonized polyaniline spheres/selenium (HCPS/Se) composite was prepared by a simple combination method of a self-assembly method, pyrolysis and vapor phase infusion process as a cathode material for Li–Se rechargeable batteries. The composites were characterized and examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, the X-ray photoelectron spectroscopy and electrochemical methods, such as cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge tests. The HCPS/Se composite cathode can deliver relative high capacity, high Coulombic efficiency and good cycling performance. The electrochemical results show that the HCPS/Se composite cathode exhibits an initial discharge specific capacity of 571.5 mA h g{sup −1} and retains 298.7 mA h g{sup −1} with high Coulombic efficiency after 100 cycles at a high rate of 0.5 C (337.5 mA h g{sup −1}), which are higher than that of the pristine selenium cathode. The excellent electrochemical properties benefit from the high conductivity and the hollow structures of the carbonized polyaniline spheres.

  7. Facile synthesis of hollow carbonized polyaniline spheres to encapsulate selenium for advanced rechargeable lithium–selenium batteries

    International Nuclear Information System (INIS)

    Highlights: • Hollow carbonized polyaniline spheres was prepared by a simple copper(II)-catalyzed self-assembly method. • Hollow carbonized polyaniline spheres can effectively constrain the selenium and polyselenides. • The hollow carbonized polyaniline spheres/selenium composite cathode exhibits excellent electrochemical properties. - Abstract: A hollow carbonized polyaniline spheres/selenium (HCPS/Se) composite was prepared by a simple combination method of a self-assembly method, pyrolysis and vapor phase infusion process as a cathode material for Li–Se rechargeable batteries. The composites were characterized and examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, the X-ray photoelectron spectroscopy and electrochemical methods, such as cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge tests. The HCPS/Se composite cathode can deliver relative high capacity, high Coulombic efficiency and good cycling performance. The electrochemical results show that the HCPS/Se composite cathode exhibits an initial discharge specific capacity of 571.5 mA h g−1 and retains 298.7 mA h g−1 with high Coulombic efficiency after 100 cycles at a high rate of 0.5 C (337.5 mA h g−1), which are higher than that of the pristine selenium cathode. The excellent electrochemical properties benefit from the high conductivity and the hollow structures of the carbonized polyaniline spheres

  8. RESPONSE OF SELENIUM STATUS INDICATORS TO SUPPLEMENTATION OF HEALTHY NORTH AMERICAN MEN WITH HIGH-SELENIUM YEAST

    Science.gov (United States)

    In a prior study, we observed decreased serum 3,3’,5-triiodothyronine (t3), increased serum thyrotropin and increased body weight in 5 men fed 297 'g/d of selenium (Se) in foods naturally high in Se while confined in a metabolic research unit. In an attempt to replicate and confirm those observation...

  9. Effect of Zeolite and Foliar Application of Selenium on Growth, Yield and Yield Component of Three Canola Cultivar under Conditions of Late Season Drought Stress

    Directory of Open Access Journals (Sweden)

    Hossein ZAHEDI

    2009-12-01

    Full Text Available In order to study effect of zeolite soil application and selenium foliar application on growth, yield and yield components of three canola cultivar under conditions of late season drought stress an experiment was conducted in two growing season in 2006 and 2007. Site study was field of Seed and Plant Improvement Institute, Karaj, Iran. The experimental design was a Randomized Complete Block arrangement in factorial split plot with three replications. Irrigation factors were chosen at two levels, included complete irrigation and irrigation holding at stem elongation stage. Zeolite was used at two levels, non application and 10 ton per hectare. Also selenium was sprayed at three concentrations, 0, 15 and 30 gr per liter from sodium selenate. These treatments were randomized in main plots while three canola cultivars (�Zarfam�, �Okapi� and �Sarigol� were randomized in sub plots. The results showed that, main effects of different irrigation levels have significant effect on all traits and drought stress decreased significantly all traits. Foliar application of selenium had significant and additive effect on plant height, number of pods in plant, number of seeds in pod, seed yield, biological yield, harvest index and oil yield. There was significant difference between zeolite application and non application on all traits except oil percent and harvest index. It was shown that canola cultivars were different in all of studied traits. Comparison of means showed that, four critical traits that is seed yield, biological yield, harvest index and oil yield were affected by experimental treatments. Different cultivars have different responses under unlike conditions inside upon traits. Under different treatment conditions especially drought stress, zeolite and selenium application have positive and significant effect on traits related to yield. In finally, zeolite and selenium application in dry lands that are exposure to late season drought

  10. The Effect of Various Forms and Doses of Selenium Supplementation of the Hens Diet on Selected Qualitative Parameters and Freshness of Table Eggs

    Directory of Open Access Journals (Sweden)

    Henrieta Arpášová

    2012-05-01

    Full Text Available In this experiment the effects of supplementing of the diet for laying hens with sodium selenite (SS or selenized yeast (SY on the quality and content of some minerals of eggs were studied. Hy-Line Brown chickens were randomly divided on the day of hatching into 4 groups (12 birds per group. The birds were fed from day 1 of life till 9 months of age with diets differing in amounts and/or forms of selenium. The control group received a basal diet (BD containing selenium naturally occurring in feeds (0.1 mg Se/kg of dry matter (DM. The first and second experimental groups were fed by the same BD enriched with Se at a dose of 0.4 mg/kg DM from sodium selenite or selenized yeast, respectively. The feed for the third experimental group consisted of BD supplemented with selenized yeast to a final selenium content of 1.0 mg/kg DM. The results showed that supplementation of SY to the diet significantly affected egg weight and Haugh units. The Haugh units in both hybrids were higher in all experimental groups of hens fed with feed supplement of selenium in both forms, with significant differences only in the groups with addition of organic forms at both doses compared to the control group (84.52±3.87, 86.60±3.80, 87.21±4.10*, 86.93±3.56*, P<0.05, respectively. Freshness of eggs was positively influenced by the addition of selenium, but with no statistically significant difference (P>0.05. Higher values were recorded in each of the four analyzes in the groups with the addition of selenium in the form of selenized yeast. Analyzing after three weeks of storage showed an obvious decrease of Haugh units in relation to the decreasing quality of the internal contents of eggs (75.39±3.07, 76.15±2.97, 78.77±4.32, 78.24± 4.84, P>0.05 but still retained a tendency to higher values in groups with the addition of selenium, especially organic form.

  11. Influence of biochar amendments on marine sediment trace metal bioavailability

    Science.gov (United States)

    Gehrke, G. E.; Hsu-Kim, H.

    2014-12-01

    Biochar has become a desirable material for use in agricultural application to enhance soil quality and in-situ soil and sediment remediation to immobilize organic contaminants. We investigated the effects of biochar sediment amendments on the bioavailability of a suite of inorganic trace metals (Cr, Co, Ni, Cu, Zn, Pb) in contaminated sediments from multiple sites in Elizabeth River, VA. We incubated sediments in microcosms with a variety of water column redox and salinity conditions and compared sediments amended with two types of woody biochar to sediments amended with charcoal activated carbon and unamended sediments. We leached sediments in artificial gut fluid mimic of the benthic invertebrate Arenicola marina as a measure of bioavailability of the trace metals analyzed. In unamended anaerobic sediments, the gut fluid mimic leachable fraction of each trace metal is 1-4% of the total sediment concentration for each metal. Initial results indicate that in anaerobic microcosms, woody biochar sediment amendments (added to 5% dry wt) decrease the gut fluid mimic leachable fraction by 30-90% for all trace metals analyzed, and have comparable performance to charcoal activated carbon amendments. However, in microcosms without controlled redox conditions, woody biochar amendments increase the bioavailable fraction of Ni and Cu by up to 80%, while decreasing the bioavailable fraction of Co, Zn, and Pb by approximately 50%; charcoal activated carbon amendments decreased the bioavailability of all trace metals analyzed by approximately 20%. In microcosms without an overlying water column, biochar and activated carbon amendments had no significant effects on trace metal bioavailability. This research demonstrates that biochar can effectively decrease the bioavailability of trace metals in marine sediments, but its efficiency is metal-specific, and environmental conditions impact biochar performance.

  12. The influence of selected hypotensive drugs on the bioavailability of minerals from buckwheat groats in vitro enzymatic digestion

    OpenAIRE

    Joanna Suliburska; Paweł Bogdański; Barbara Chiniewicz

    2011-01-01

    Background. The mineral status in hypertensive patients may be affected by hypotensive drugs. The aim of this study was to estimate the influence of hypotensive drugs (angiotensine converting enzyme inhibitors (ACE-I), b-blockers, Ca-antagonists, diuretics) on the potential bioavailability of magnesium, iron, zinc and copper from buckwheat groats in vitro enzymatic digestion. Material and methods. The degree of release of magnesium, iron, zinc and copper from buckwheat groats was determined w...

  13. Effects of Dietary Selenium and Vitamin E on Growth Performance, Meat Yield, and Selenium Content and Lipid Oxidation of Breast Meat of Broilers Reared Under Heat Stress.

    Science.gov (United States)

    Habibian, Mahmood; Ghazi, Shahab; Moeini, Mohammad Mehdi

    2016-01-01

    This study was conducted using 360 broiler chickens to evaluate the effects of dietary vitamin E (0, 125, and 250 mg/kg), selenium (0, 0.5, and 1 mg/kg), or their different combinations on performance, meat yield, and selenium content and lipid oxidation of breast meat of broilers raised under either a thermoneutral (TN, 24 °C constant) or heat stress (HS, 24 to 37 °C cycling) condition. There was a reduction (P  0.05) to that of broilers receiving 250 mg/kg vitamin E and 1 mg/kg selenium. The malondialdehyde (MDA) content of the breast meat was increased (P diet of TN birds. However, the breast meat selenium content was increased (P  0.05) by dietary treatments under TN condition. However, the breast meat MDA content was decreased (P < 0.05) by both vitamin E and selenium supplementation under HS condition, and the lowest MDA content was observed in the breast meat of broilers receiving combination of 125 mg/kg vitamin E and 1 mg/kg selenium. The results showed that supplementation of selenium and vitamin E was capable of increasing the selenium content of the breast meat and could improve the lipid oxidation of the breast meat when broilers reared under HS condition. PMID:26085059

  14. Changes in the biosynthetic pathways involved in selenium assimilation in wheat from a seleniferous area

    International Nuclear Information System (INIS)

    Complete text of publication follows. Selenium is an essential micronutrient that plays an important role in human biology. Besides its well known protective action against oxidative stress in body tissues, selenium has also been implicated in the maintenance of defences against infection, modulation of growth and development, and, at supra-nutritional levels, reduction of cancer risk. Selenium enters the food chain through plants, which absorb it through their roots in highly variable amounts according to the species and the bioaccessible levels in soils. Accumulation of selenium by plants is due to to their ability to transform inorganic selenium into a variety of selenocompounds, including bioactive compounds, which has important implications for human nutrition and health. Therefore, the understanding of selenium assimilation pathways in plants over a range of selenium environmental levels is of critical importance. Samples of wheat (Triticum aestivum) were collected in two villages in the Nawanshahr-Hoshiarpur Region, a seleniferous area of Punjab (India). Two sampling campaigns were carried out in September and February, respectively. Both grain and seeds, on the one hand, and vegetative plant tissues, on the other hand, were sampled and analysed. Total selenium concentrations in grains were determined by ICP-MS after microwave digestion. Selenium speciation was carried out after enzymatic extraction with protease and amylase using an ultrasonic probe. Extraction efficiency was ≥80%. Speciation studies of wheat grain extracts were carried out by HPLC with on-line ICP-DRC-MS detection. Three different separation mechanisms were used in order to verify the identification of the analytes: reversed phase, cation exchange and anion exchange. Selenium was detected by at m/z 80 using methane as the reactive gas in the dynamic reaction cell. Grain-based reference materials were analysed as well. Total selenium concentrations in wheat grain were 29-185 μg/g (dry

  15. Tuning the internal structures of CdSeS nanoparticles by using different selenium and sulphur precursors

    International Nuclear Information System (INIS)

    Alloyed CdSeS nanoparticles (NPs) with composition gradient and homogeneous internal structures have been successfully prepared in aqueous solution by using different selenium and sulphur precursors. The as-prepared NPs form a homogeneous internal structure when sodium selenide and sodium sulphide were used as selenium and sulphur precursors, respectively. Gradient internal structures were obtained for alloyed CdSeS NPs prepared by using sodium selenosulphate and sodium thiosulphate as selenium and sulphur precursors, respectively. The method takes advantage of the fact that different selenium/sulphur sources release selenium/sulphur ions at different rates or have different reaction rates of selenium/sulphur toward cadmium.

  16. Intestinal Oxidative State Can Alter Nutrient and Drug Bioavailability

    Directory of Open Access Journals (Sweden)

    Faria Ana

    2009-01-01

    Full Text Available Organic cations (OCs are substances of endogenous (e.g., dopamine, choline or exogenous (e.g., drugs like cimetidine origin that are positively charged at physiological ph. since many of these compounds can not pass the cell membrane freely, their transport in or out of cells must be mediated by specific transport systems. Transport by organic cation transporters (OCTs can be regulated rapidly by altering their trafficking and/or affinities in response to stimuli. However, for example, a specific disease could lead to modifications in the expression of OCTs. Chronic exposure to oxidative stress has been suggested to alter regulation and functional activity of proteins through several pathways. According to results from a previous work, oxidation-reduction pathways were thought to be involved in intestinal organic cation uptake modulation. The present work was performed in order to evaluate the influence of oxidative stressors, especially glutathione, on the intestinal organic cation absorption. For this purpose, the effect of compounds with different redox potential (glutathione, an endogenous antioxidant, and procyanidins, diet antioxidants was assessed on MPP+ (1-methyl-4-phenylpyridinium iodide uptake in an enterocyte cell line (Caco-2. Caco-2 cells were subcultured with two different media conditions (physiological: 5 mM glucose, referred as control cells; and high-glucose: 25 mM glucose, referred as HG cells. In HG cells, the uptake was significantly lower than in control cells. Redox changing interventions affected Mpp+ uptake, both in control and in high-glucose Caco-2 cells. Cellular glutathione levels could have an important impact on membrane transporter activity. The results indicate that modifications in the cellular oxidative state modulate MPP+ uptake by Caco-2 cells. Such modifications may reflect in changes of nutrient and drug bioavailability.

  17. Evaluation of Selenium Content of Plant Samples Collected from Indigenous Sources for Se-supplementation

    International Nuclear Information System (INIS)

    Selenium contents were evaluated in different plant species such as Canola (Brassica napus), Sunflower (Helianthus annus), Turmeric (Curcuma longa), Soyabean Seeds (Glycine max) and Akk (Calotropis procera) in order to access their possibility for Se-supplementation. The dry ash of bulb of Turmeric and seeds of Canola, Sunflower, and Soyabean were digested in concentrated HNO/sub 3/, HClO/sub 4/ and HCl to obtain selenium (IV). After adding different reagents, stable blue colored complex was formed. From this colored complex, selenium (IV) was determined by UV/visible spectrophotometer. This work was carried out in an attempt to obtain information concerning the amount of selenium present in different plants. It was observed that Akk is a good accumulator of selenium as it contains almost 30 mu g selenium per gram and can be used for different medicinal applications. (author)

  18. Redox-Active Selenium Compounds—From Toxicity and Cell Death to Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Sougat Misra

    2015-05-01

    Full Text Available Selenium is generally known as an antioxidant due to its presence in selenoproteins as selenocysteine, but it is also toxic. The toxic effects of selenium are, however, strictly concentration and chemical species dependent. One class of selenium compounds is a potent inhibitor of cell growth with remarkable tumor specificity. These redox active compounds are pro-oxidative and highly cytotoxic to tumor cells and are promising candidates to be used in chemotherapy against cancer. Herein we elaborate upon the major forms of dietary selenium compounds, their metabolic pathways, and their antioxidant and pro-oxidant potentials with emphasis on cytotoxic mechanisms. Relative cytotoxicity of inorganic selenite and organic selenocystine compounds to different cancer cells are presented as evidence to our perspective. Furthermore, new novel classes of selenium compounds specifically designed to target tumor cells are presented and the potential of selenium in modern oncology is extensively discussed.

  19. Photochemical alkylation of inorganic selenium in the presence of low molecular weight organic acids.

    Science.gov (United States)

    Guo, Xuming; Sturgeon, Ralph E; Mester, Zoltán; Gardner, Graeme J

    2003-12-15

    Using a flow-through photochemical reactor and a low pressure mercury lamp as a UV source, alkyl selenium species are formed from inorganic selenium(IV) in the presence of low molecular weight organic acids (LMW acids). The volatile alkyl Se species were cryogenically trapped and identified by GC-MS and GC-ICP-MS. In the presence of formic, acetic, propionic and malonic acids, inorganic selenium(IV) is converted by UV irradiation to volatile selenium hydride and carbonyl, dimethylselenide and diethylselenide, respectively. Se(IV) was successfully removed from contaminated agricultural drainage waters (California, U.S.A.) using a batch photoreactor system Se. Photochemical alkylation may thus offer a promising means of converting toxic selenium salts, present in contaminated water, to less toxic dimethylselenide. The LMW acids and photochemical alkylation process may also be key to understanding the source of atmospheric selenium and are likely involved in its mobility in the natural anaerobic environment. PMID:14717175

  20. Selenium status, thyroid volume, and multiple nodule formation in an area with mild iodine deficiency

    DEFF Research Database (Denmark)

    Rasmussen, Lone Banke; Schomburg, Lutz; Kohrle, Josef; Pedersen, Inge Bulow; Hollenbach, Birgit; Hog, Antonia; Ovesen, Lars; Perrild, Hans; Laurberg, Peter

    2011-01-01

    ) introduction of iodine fortification. Serum selenium concentration and urinary iodine were measured, and the thyroid gland was examined by ultrasonography in the same subjects. Associations between serum selenium concentration and thyroid parameters were examined in multiple linear regression models or...... logistic regression models.Results: Serum selenium concentration was found to be significantly, negatively associated with thyroid volume (P=0.006), and a low selenium status significantly increased the risk for thyroid enlargement (P=0.007). Furthermore, low serum selenium status had a tendency to...... increase the risk for development of multiple nodules (P=0.087).Conclusions: Low serum selenium concentration was associated with a larger thyroid volume and a higher prevalence of thyroid enlargement....