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Sample records for dietary selenium se

  1. Dietary Selenium (Se) and Copper (Cu) Interact to Affect Homocysteine Metabolism in Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our previous studies have shown that selenium (Se) is protective against dimethylhydrazine (DMH)-induced preneoplastic colon cancer lesions, and protection against DNA damage has been hypothesized to be one mechanism for the anticancer effect of Se. The present study was designed to determine whethe...

  2. Dietary selenium and selenoprotein function

    PubMed Central

    Weeks, Benjamin S.; Hanna, Mirna S.; Cooperstein, Deborah

    2012-01-01

    Summary Selenium is a trace mineral and an essential nutrient in the human diet. Selenium is found in soil and water and consequently enters the food chain through the root ways of plants and aquatic organisms. Some areas of the world are low in soil selenium resulting in a selenium deficient population and the appearance of an associated heart disease and bone disorders that can be corrected with dietary selenium. Indeed the requirement for dietary selenium was established by these observations and while selenium deficiency is rare in the West, patients requiring long-term intravenous feedings have also show heart disease associated with a deficiency of selenium in the feeding fluids. Subsequently, it has been established that dietary selenium can improve a wide range of human health conditions even in areas with soil replete in selenium. PMID:22847213

  3. Dietary selenium (Se) and copper (Cu) interact to affect homocysteine metabolism in rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously we reported that both Se deficiency (SeD) and Cu deficiency (CuD) decreased plasma homocysteine (pHcys) and increased plasma glutathione (pGSH) in rats. We also showed that the catalytic subunit of glutamate-cysteine ligase (Gclc), which catalyzes the rate limiting step in glutathione bio...

  4. Effect of dietary selenium (Se) on the development of fusarium-induced tibial dyschondroplasia (FITD) in broiler chickens

    SciTech Connect

    Walser, M.M.; Levander, O.A.

    1986-03-01

    The purposes of this study were to determine the effect of low and high levels of dietary Se on the pathogenesis of FITD and to use the findings to assess the applicability of FITD as an animal model of Kashin-Beck disease. Day-old female broiler chickens were assigned to 1 or 3 diets: low Se (0.02 ppm), normal Se (0.15 ppm), and high Se (0.5 ppm). At 1 week of age, dosing of 15 of 26 chicks in each dietary group with TDP-1, the toxic component of fusarium roseum Graminearum was begun. Chicks were terminated from 24 to 30 days of age. The mortality rate of the TDP-1-treated chicks on the high Se diet was significantly less than that in the other TDP-treated groups. There were no differences in the incidence, severity, or character of the FITD lesions among the dietary groups. Neither diet nor TDP-1 treatment affected hematocrit levels. Plasma Se and hepatic glutathione peroxidase activity were significantly lower in the low Se dietary group than in other groups. The nature of the lesion of FITD and the time course of its development are distinct from the features of Kashin-Beck disease. Administration of a high dietary level of Se did not affect the development of FITD.

  5. Selenium in groundwater and its contribution towards daily dietary Se intake under different hydrogeological zones of Punjab, India

    NASA Astrophysics Data System (ADS)

    Dhillon, Karaj S.; Dhillon, Surjit K.

    2016-02-01

    More than 750 groundwater samples collected from different hydrological zones of Punjab state in India were analysed for selenium and some quality parameters to determine suitability of groundwater for irrigation and drinking purpose. Selenium content varied from 0.01 to 35.6 μg L-1. Average Se content in groundwater was the highest in Northeastern Siwalik foothill zone (NSFZ) followed by Central zone (CZ) and Southwestern zone (SWZ). Majority of the water samples contained <10 μg Se L-1 - the safe limit for drinking purpose except one location each in SWZ and CZ and three locations in NSFZ. Only at one location, water contained >20 μg Se L-1 which is considered unsuitable for irrigation of crops. On the basis of pH, 42% of the samples were unfit for drinking in SWZ, 41% in CZ and 6% in NSFZ. Only in SWZ, 24% of the samples with high total dissolved salts were unfit for drinking and 18% unfit for irrigation purpose due to high EC. Selenium content in groundwater was inversely related to depth of water and the degree of relationship was higher for NSFZ (r = -0.342∗∗) followed by CZ (r = -0.157∗) and SWZ (r = -0.126∗). Depending on the amount of water consumed from 2 to 5 L, average Se intake varied from 1.66 to 6.39 μg d-1 and its contribution towards the recommended daily Se allowance ranged from 3.0% to 11.6% for women and 2.4% to 9.1% for men. Among the grain samples, 94% of wheat and 46% of rice contained Se above the deficiency limit of 100 μg kg-1. Thus, the residents in the study area primarily consuming wheat grains and drinking groundwater are getting adequate supply of Se. Among the materials tested for decreasing Se from drinking waters, scrap iron fillings showed potential for commercial use.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. Strategic Use of Naturally Selenium (Se)-rich Milling Coproducts to Eliminate Se Deficiency and Create Se-enriched Foods.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is essential for sustaining a healthy life. When dietary Se was marginally deficient, populations experienced impaired reproduction and growth rates and increased disease rates. Selenium-rich grains, harvested from regions with seleniferous soils, were natural sources of bioavailable S...

  8. Comparison of dietary selenium fed to grower-finisher pigs from various regions of the United States on resulting tissue Se and loin mineral concentrations.

    PubMed

    Mahan, D C; Brendemuhl, J H; Carter, S D; Chiba, L I; Crenshaw, T D; Cromwell, G L; Dove, C R; Harper, A F; Hill, G M; Hollis, G R; Kim, S W; Lindemann, M D; Maxwell, C V; Miller, P S; Nelssen, J L; Richert, B T; Southern, L L; Stahly, T S; Stein, H H; van Heugten, E; Yen, J T

    2005-04-01

    A study was conducted to evaluate the mineral content of pork tissue with particular emphasis on Se between various states (regions) having different diet (grain) indigenous Se concentrations. The study involved 19 states in the north, central, and southern regions of the United States, with committee members of NCR-42 and S-1012 (formerly S-288). A total of 62 pigs were used, with collaborators sending 100-g samples each of loin, heart, and liver, and a 3- to 4-g sample of hair (collected along the topline) from two to five market-weight pigs to a common laboratory for analysis. Diets at each station were formulated with locally purchased soybean meal and grain that was either grown or normally fed to pigs within their state. Tissues were analyzed for Se, but only the loin was analyzed for the macro- and micromineral elements. Correlation of dietary minerals to the tissue element was determined. The results demonstrated differences in tissue Se among states (P < 0.01), with high correlations of dietary Se to loin (r = 0.84; P < 0.01), heart (r = 0.84; P < 0.01), liver (r = 0.83; P < 0.01), and hair Se (r = 0.90; P < 0.01) concentrations. The correlation of hair Se to the Se concentration of loin, heart, and liver tissues was high (r > 0.90; P < 0.01). States in the west-central region of the United States and west of the Mississippi river had higher dietary Se and tissue Se concentrations than states in the eastern section of the Corn Belt, east of the Mississippi river, and along the East Coast. Generally, states did not differ greatly in their loin macro- and micromineral concentrations. The simple correlation of dietary minerals to their corresponding loin mineral concentration was generally non-significant, but most macrominerals had decreasing mineral concentrations when the dietary mineral level was higher. These results indicate that regional differences in tissue Se were influenced more by the indigenous Se content of the diet (grain) fed to the pigs than

  9. SELENIUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter addresses the nutritional functions of selenium, including the consequences of nutritional selenium deficiency and the role of selenium in the prevention of cancer. These functions are discussed in terms of the absorption and metabolism of dietary selenium, with special focus on the sel...

  10. Effects of dietary selenium on host response to necrotic enteritis in young broilers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of dietary supplementation of young broiler chickens with a new organic selenium (Se) formulation, B-Traxim Se, on the host response to experimental necrotic enteritis (NE) were studied. Broiler chickens treated with three Se doses (0.25, 0.50, 1.00 mg/kg) from hatch were orally challeng...

  11. Dietary selenium supplementation and whole blood gene expression in healthy North American men

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is a trace nutrient required in microgram amounts by all animals, with a recommended dietary allowance of 55 µg/d in humans. The biological functions of Se are performed by a group of 25 selenoproteins containing the unusual amino acid selenocysteine at their active sites. The selenopr...

  12. Spectrum of sodiumlike selenium - Se XXIV

    NASA Technical Reports Server (NTRS)

    Brown, C. M.; Seely, J. F.; Feldman, U.; Richardson, M. C.; Behring, W. E.; Cohen, L.

    1986-01-01

    High-resolution spectra of Se XXIV have been obtained with a 3-m grazing-incidence spectrograph. Thin plastic foils coated with selenium were irradiated with four or eight beams of the OMEGA laser in a line-focus configuration. Spectrograms were obtained by viewing the plasma axially. Prominent in the spectra were the 3s-3p and 3p-3d transitions in the 150-240-A region and the transitions nl-(n + 1)l-prime with n = 3, 4 in the 24-80-A region. The energy levels and ionization limit derived from the measured wavelengths are also presented.

  13. Daily dietary selenium intake and hair selenium content in a high selenium area of Enshi, China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium is essential to humans and is widely distributed within the human body. Its content in blood, urine, hair and nails are important indicators to evaluate Se level in the human body. In China (Shadi, Enschi city), human selenosis of residents is reported to occur in high numbers. In this stud...

  14. Dietary selenium in adjuvant therapy of viral and bacterial infections.

    PubMed

    Steinbrenner, Holger; Al-Quraishy, Saleh; Dkhil, Mohamed A; Wunderlich, Frank; Sies, Helmut

    2015-01-01

    Viral and bacterial infections are often associated with deficiencies in macronutrients and micronutrients, including the essential trace element selenium. In selenium deficiency, benign strains of Coxsackie and influenza viruses can mutate to highly pathogenic strains. Dietary supplementation to provide adequate or supranutritional selenium supply has been proposed to confer health benefits for patients suffering from some viral diseases, most notably with respect to HIV and influenza A virus (IAV) infections. In addition, selenium-containing multimicronutrient supplements improved several clinical and lifestyle variables in patients coinfected with HIV and Mycobacterium tuberculosis. Selenium status may affect the function of cells of both adaptive and innate immunity. Supranutritional selenium promotes proliferation and favors differentiation of naive CD4-positive T lymphocytes toward T helper 1 cells, thus supporting the acute cellular immune response, whereas excessive activation of the immune system and ensuing host tissue damage are counteracted through directing macrophages toward the M2 phenotype. This review provides an up-to-date overview on selenium in infectious diseases caused by viruses (e.g., HIV, IAV, hepatitis C virus, poliovirus, West Nile virus) and bacteria (e.g., M. tuberculosis, Helicobacter pylori). Data from epidemiologic studies and intervention trials, with selenium alone or in combination with other micronutrients, and animal experiments are discussed against the background of dietary selenium requirements to alter immune functions. PMID:25593145

  15. Significant Beneficial Association of High Dietary Selenium Intake with Reduced Body Fat in the CODING Study

    PubMed Central

    Wang, Yongbo; Gao, Xiang; Pedram, Pardis; Shahidi, Mariam; Du, Jianling; Yi, Yanqing; Gulliver, Wayne; Zhang, Hongwei; Sun, Guang

    2016-01-01

    Selenium (Se) is a trace element which plays an important role in adipocyte hypertrophy and adipogenesis. Some studies suggest that variations in serum Se may be associated with obesity. However, there are few studies examining the relationship between dietary Se and obesity, and findings are inconsistent. We aimed to investigate the association between dietary Se intake and a panel of obesity measurements with systematic control of major confounding factors. A total of 3214 subjects participated in the study. Dietary Se intake was determined from the Willett food frequency questionnaire. Body composition was measured using dual-energy X-ray absorptiometry. Obese men and women had the lowest dietary Se intake, being 24% to 31% lower than corresponding normal weight men and women, classified by both BMI and body fat percentage. Moreover, subjects with the highest dietary Se intake had the lowest BMI, waist circumference, and trunk, android, gynoid and total body fat percentages, with a clear dose-dependent inverse relationship observed in both gender groups. Furthermore, significant negative associations discovered between dietary Se intake and obesity measurements were independent of age, total dietary calorie intake, physical activity, smoking, alcohol, medication, and menopausal status. Dietary Se intake alone may account for 9%–27% of the observed variations in body fat percentage. The findings from this study strongly suggest that high dietary Se intake is associated with a beneficial body composition profile. PMID:26742059

  16. A Review of Dietary Selenium Intake and Selenium Status in Europe and the Middle East

    PubMed Central

    Stoffaneller, Rita; Morse, Nancy L.

    2015-01-01

    This is a systematic review of existing data on dietary selenium (Se) intake and status for various population groups in Europe (including the United Kingdom (UK)) and the Middle East. It includes English language systematic reviews, meta-analyses, randomised controlled trials, cohort studies, cross-sectional and case-control studies obtained through PUBMED searches from January, 2002, to November, 2014, for European data and from 1990 to November 2014, for Middle Eastern data. Reports were selected if they included data on Se intake and status. The search identified 19 European/UK studies and 15 investigations in the Middle East that reported Se intake and Se concentration in water and/or food and 48 European/UK studies and 44 investigations in the Middle East reporting Se status. Suboptimal Se status was reported to be widespread throughout Europe, the UK and the Middle East, and these results agreed with previous reports highlighting the problem. Eastern European countries had lower Se intake than Western European countries. Middle Eastern studies provided varying results, possibly due to varying food habits and imports in different regions and within differing socioeconomic groups. In conclusion, Se intake and status is suboptimal in European and Middle Eastern countries, with less consistency in the Middle East. PMID:25734564

  17. Selenium-Fertilized Tritordeum (× Tritordeum Ascherson et Graebner) as Dietary Selenium Supplement in Laying Hens: Effects on Egg Quality.

    PubMed

    Tufarelli, V; Cazzato, E; Ceci, E; Laudadio, V

    2016-09-01

    The aim of the present study was to investigate the effect of adding selenium (Se) in cereal production by fertilization on Se concentration in laying hen eggs. Tritordeum (×Tritordeum Ascherson et Graebner), a new cereal from the cross between durum wheat and a wild barley species having accreditation as natural crop species, was produced using selenate as Se-fertilizer. Hy-Line Brown laying hens were randomly allocated to two dietary treatments and fed for 10 weeks. Hens were fed two corn-soybean meal-based diets comprising a control basal diet including Tritordeum (100 g/kg diet) cv. Aucan grown without Se fertilization (containing background Se only from premix supplying 1,0 times birds' requirements) and a test-diet containing Se-enriched Tritordeum at the same level of the control diet. No difference was observed among dietary treatments on feed consumption and efficiency, egg mass, and laying rate, whereas egg yolk Se and vitamin E contents as well as liver and plasma Se levels were significantly influenced by dietary Se-enriched Tritordeum. Based on our findings, Se-enriched Tritordeum improved egg quality without affecting hens' productive performance. Thus, Se-fertilized Tritordeum may represent a valuable natural source of Se compared to conventional dietary supplements. PMID:26899320

  18. Dietary selenium supplementation modifies breast tumor growth and metastasis.

    PubMed

    Chen, Yu-Chi; Prabhu, K Sandeep; Das, Arunangshu; Mastro, Andrea M

    2013-11-01

    The survival rate for breast cancer drops dramatically once the disease progresses to the metastatic stage. Selenium (Se) is an essential micronutrient credited with having high anticancer and chemopreventive properties. In our study, we investigated if dietary Se supplementation modified breast cancer development in vivo. Three diets supplemented with sodium selenite, methylseleninic acid (MSA) or selenomethionine (SeMet), as well as a Se-deficient and a Se-adequate diet were fed to mice before mammary gland inoculation of 4T1.2 cells. The primary tumor growth, the numbers of cancer cells present in lungs, hearts, livers, kidneys and femurs and several proinflammatory cytokines were measured. We found that inorganic selenite supplementation provided only short-term delay of tumor growth, whereas the two organic SeMet and MSA supplements provided more potent growth inhibition. These diets also affected cancer metastasis differently. Mice fed selenite developed the most extensive metastasis and had an increased incidence of kidney and bone metastasis. On the other hand, mice fed the SeMet diet showed the least amount of cancer growth at metastatic sites. The MSA diet also provided some protection against breast cancer metastasis although the effects were less significant than those of SeMet. The cytokine profiles indicated that serum levels of interlukin-2, interleukin-6, interferon γ and vascular endothelial growth factor were elevated in SeMet-supplemented mice. There was no significant difference in tumor growth and the patterns of metastasis between the Se-deficient and Se-adequate groups. Our data suggest that organic Se supplementation may reduce/delay breast cancer metastasis, while selenite may exacerbate it. PMID:23613334

  19. Lack of an effect of dietary selenium on serum albumin, glucose and urea nitrogen in ewes.

    PubMed Central

    Sugden, E A; Hidiroglou, M; Mitchell, D

    1978-01-01

    The results of a study on the effect of dietary selenium administered with vitamin E on serum levels of albumin, glucose and urea nitrogen in ewes are reported. In October, at the onset of breeding, after ten months on a dystrophogenic diet, mean serum levels of albumin (g/dl), glucose (mg/dl) and urea nitrogen (mg/dl) were respectively 3.5, 52.9 and 12.8, in 65 Se-deficient ewes and 3.6, 51.7 and 14.3 in 65 Se-adequate ewes. Despite a significant difference in the serum level of urea nitrogen between Se-deficient and Se-adequate groups, no consistent effect of dietary selenium was apparent. PMID:688079

  20. Dietary Selenium (Se) and Copper (Cu) Affect the Activity and Expression of the Hepatic Selenoprotein Methionine Sulfoxide Reductase B (MrsB) in Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As reported by Jenkinson et al. (J Nutr 1982) and Prohaska et al. (J Nutr Biochem 1992) Cu deficiency (CuD) decreases the activity and mRNA expression of the selenoprotein GPx. Because both Se and Cu are important in oxidative defense, we wanted to determine the effect of a combined deficiency on th...

  1. 2-Hydroxy-4-Methylselenobutanoic Acid as New Organic Selenium Dietary Supplement to Produce Selenium-Enriched Eggs.

    PubMed

    Tufarelli, V; Ceci, E; Laudadio, V

    2016-06-01

    Food-based strategies need to be developed to improve the selenium (Se) status of individuals. The aim of this study was to evaluate the effects of a new organic Se [2-hydroxy-4-methylselenobutanoic acid (HMSeBA)] on selected performance criteria and Se deposition in egg of laying hens. Isa Brown laying hens, 18 weeks of age were randomly allocated to two dietary treatments and fed for 10 weeks. The hens were fed two corn-soybean meal-based diets comprising a control basal diet without Se supplementation and a test diet supplemented with Se at 0.2 mg/kg from HMSeBA. No difference was observed among dietary treatments on feed intake, egg weight and laying rate, whereas egg yolk fatty acid profile and vitamin E content were positively influenced by HMSeBA supplementation. Hens fed Se-supplemented diet exhibited greater (P < 0.001) egg yolk total Se contents, which averaged 21.2 mg/100 g dry matter (DM) compared to control diet (11.7 mg/100 g DM). Our results suggested that HMSeBA as Se supplement influences positively egg yolk quality without affecting hens' productive traits. Moreover, HMSeBA offers an efficient alternative to fortify eggs with Se, which can consequently lead to greater supply of Se for humans. PMID:26521985

  2. Potential enrichment of medicinal mushrooms with selenium to obtain new dietary supplements.

    PubMed

    Milovanovic, Ivan; Brceski, Ilija; Stajic, Mirjana; Knezevic, Aleksandar; Vukojevic, Jelena

    2013-01-01

    The purpose of this study was to resolve the question of whether various selenium concentrations affect the ability of eight species, members of five genera, to produce mycelium biomass and absorb this trace element during submerged cultivation in Na2SeO3-enriched medium. The obtained results demonstrated the ability of mycelia of all of the tested species to absorb selenium at analyzed concentrations. Thus, selenium content ranged from 1.4 µg g-1 (Pleurotus eryngii) to 20.3 µg g-1 (Pleurotus ostreatus). The potential of mycelia to absorb selenium was significant, ranging from 8.1% (Lenzites betulinus) to 62.5% (P ostreatus) of its content in the medium. It may be concluded that all tested mushroom species could be used as satisfactory selenium sources due to the fact that the absorbed concentrations ranged from 15.8% (P. eryngii) to 36.9% (P. ostreatus) of the dietary selenium amount (55 µg d-1) recommended by the European Scientific Committee on Food. PMID:24266370

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

    PubMed

    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

  4. Interactive effects of arsenate, selenium, and dietary protein on survival, growth, and physiology in mallard ducklings

    USGS Publications Warehouse

    Hoffman, D.J.; Sanderson, C.J.; LeCaptain, L.J.; Cromartie, E.; Pendleton, G.W.

    1992-01-01

    High concentrations of arsenic (As) and selenium (Se) have been found in aquatic food chains associated with irrigation drainwater. Total biomass of invertebrates, a maJor source of protein for wild ducklings, may vary in environments that are contaminated with selenium. Dayold mallard (Anas platyrhynchos) ducklings received an untreated diet (controls) containing 22% protein or diets containing 15 ppm Se (as selenomethionine), 60 ppm Se, 200 ppm As (as sodium arsenate), 15 ppm Se with 200 ppm As, or 60 ppm Se with 200 ppm As. In a concurrent experiment, the same sequence was repeated with a proteinrestricted (7%) but isocaloric diet. After 4 weeks, blood and tissue samples were collected for biochemical and histological examination. With 22% protein and 60 ppm Se in the diet, duckling survival and growth was reduced and livers had histopathological lesions. Arsenic alone caused some reduction in growth. Antagonistic interactive effects occurred between As and Se, including complete to partial alleviation of the following Se effects: mortality, impaired growth, hepatic lesions and lipid peroxidation, and altered glutathione and thiol status. With 7% protein, survival and growth of controls was less than that with 22% protein, Se (60 ppm) caused 100% mortality, and As (200 ppm) caused mortality, decreased growth, and liver histopathology. These findings suggest the potential for antagonistic effects of Se and As on duckling survival, growth, and physiology with adequate dietary protein but more severe toxicological effects when dietary protein is diminished.

  5. Influence of Dietary Selenium Species on Selenoamino Acid Levels in Rainbow Trout.

    PubMed

    Godin, Simon; Fontagné-Dicharry, Stéphanie; Bueno, Maïté; Tacon, Philippe; Prabhu, Philip Antony Jesu; Kaushik, Sachi; Médale, Françoise; Bouyssiere, Brice

    2015-07-22

    Two forms of selenium (Se) supplementation of fish feeds were compared in two different basal diets. A 12-week feeding trial was performed with rainbow trout fry using either a plant-based or a fish meal-based diet. Se yeast and selenite were used for Se supplementation. Total Se and Se speciation were determined in both diets and whole body of trout fry using inductively coupled plasma mass spectrometry (ICP MS) and high-performance liquid chromatography (HPLC). The two selenoamino acids, selenomethionine (SeMet) and selenocysteine (SeCys), were determined in whole body of fry after enzymatic digestion using protease type XIV with a prior derivatization step in the case of SeCys. The plant-based basal diet was found to have a much lower total Se than the fish meal-based basal diet with concentrations of 496 and 1222 μg(Se) kg(-1), respectively. Dietary Se yeast had a higher ability to raise whole body Se compared to selenite. SeMet concentration in the fry was increased only in the case of Se yeast supplementation, whereas SeCys levels were similar at the end of the feeding trial for both Se supplemented forms. The results show that the fate of dietary Se in fry is highly dependent on the form brought through supplementation and that a plant-based diet clearly benefits from Se supplementation. PMID:26161943

  6. Dietary selenium intake increases exon-specific DNA methylation of p53 gene in rat liver and colon mucosa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The regulation of site-specific DNA methylation of tumor suppressor genes has been considered as a leading mechanism by which certain nutrients exert their anticancer property. Our previous studies suggest that dietary selenium (Se) may alter DNA methylation, and the purpose of this study was to inv...

  7. Interactive effects of selenium, methionine, and dietary protein on survival, growth, and physiology in mallard ducklings

    USGS Publications Warehouse

    Hoffman, D.J.; Sanderson, C.J.; LeCaptain, L.J.; Cromartie, E.; Pendleton, G.W.

    1992-01-01

    Concentrations of over 100 ppm (100 mg/kg) selenium (Se) have been found in aquatic food chains associated with irrigation drainwater. Both quantity and composition of dietary protein for wild ducklings may vary in selenium-contaminated environments. Day-old mallard (Anas platyrhynchos) ducklings received one of the following diets containing 22% protein: unsupplemented (controls), 15 ppm Se (as selenomethionine), 60 ppm Se, methionine supplemented, 15 ppm Se with methionine supplement, or 60 ppm Se with methionine supplement. In a second concurrent experiment the above sequence was repeated with a protein-restricted (11%) but isocaloric diet. In a third concurrent experiment all ducklings received 44% protein with 0, 15, or 60 ppm Se added. After 4 weeks, blood and tissue samples were collected for biochemical and histological examination. With 22% protein and 60 ppm Se in the diet, duckling survival and growth was reduced and histopathological lesions of the liver occurred. Antagonistic interactive effects occurred between supplementary methionine and Se, including complete to partial alleviation of the following Se effects by methionine: mortality, hepatic lesions, and altered glutathione and thiol status. With 11% protein, growth of controls was less than that with 22% protein, Se (60 ppm) caused 100% mortality, and methionine supplementation, although protective afforded less protection than it did with 22% protein. With 44% protein, ducklings experienced physiological stress, and Se was more toxic than with methionine-supplemented 22% protein. These findings suggest the potential for antagonistic effects of Se, methionine, and protein on duckling survival and physiology.

  8. Contrasting roles of dietary selenium and selenoproteins in chemically induced hepatocarcinogenesis

    PubMed Central

    Gladyshev, Vadim N.

    2013-01-01

    Selenium (Se) has long been known for its cancer prevention properties, but the molecular basis remains unclear. The principal questions in assessing the effect of dietary Se in cancer are whether selenoproteins, small molecule selenocompounds, or both, are involved, and under which conditions and genotypes Se may be protective. In this study, we examined diethylnitrosamine-induced hepatocarcinogenesis in mice lacking a subset of selenoproteins due to expression of a mutant selenocysteine tRNA gene (Trsp A37G mice). To uncouple the effects of selenocompounds and selenoproteins, these animals were examined at several levels of dietary Se. Our analysis revealed that tumorigenesis in Trsp A37G mice maintained on the adequate Se diet was increased. However, in the control, wild-type mice, both Se deficiency and high Se levels protected against tumorigenesis. We further found that the Se-deficient diet induced severe neurological phenotypes in TrspA37G mice. Surprisingly, a similar phenotype could be induced in these mice at high dietary Se intake. Overall, our results show a complex role of Se in chemically induced hepatocarcinogenesis, which involves interaction among selenoproteins, selenocompounds and toxins, and depends on genotype and background of the animals. PMID:23389288

  9. Benefits of Selenium Supplementation on Leukocyte DNA Integrity Interact with Dietary Micronutrients: A Short Communication

    PubMed Central

    Karunasinghe, Nishi; Zhu, Shuotun; Ferguson, Lynnette R.

    2016-01-01

    A male cohort from New Zealand has previously shown variability in Selenium (Se) supplementation effects on measured biomarkers. The current analysis is to understand the reasons for variability of the H2O2-induced DNA damage recorded after Se supplementation. We have looked at the variation of demographic, lifestyle, medication, genetic and dietary factors and biomarkers measured at baseline and post-supplementation in these two extreme subgroups A and B. Group A showed increased H2O2-induced DNA damage and group B showed decreased damage after Se supplementation. We have also considered correlations of biomarkers and dietary factors in the complete dataset. The glutathione peroxidase (GPx) activity and DNA damage were significantly lower at post-supplementation in Group B compared to Group A. Post-supplementation, Group B showed a significant reduction in the GPx activity, while Group A showed a significant increase in DNA damage compared to baseline levels. Dietary methionine intake was significantly higher and folate intake was significantly lower in Group B compared to Group A. Se supplementation significantly increased the caspase-cleaved keratin 18 levels in both groups, indicating increased apoptotic potential of this supplement. Parameter correlation with the complete dataset showed dietary methionine to have a significant negative correlation with H2O2-induced DNA damage post-supplementation. The data suggest that Se supplementation is beneficial for the leukocyte DNA integrity only in interaction with the dietary methionine and folate intake. PMID:27128937

  10. Mercury and Selenium in Muscle and Target Organs of Scalloped Hammerhead Sharks Sphyrna lewini of the SE Gulf of California: Dietary Intake, Molar Ratios, Loads, and Human Health Risks.

    PubMed

    Bergés-Tiznado, Magdalena E; Márquez-Farías, Fernando; Lara-Mendoza, Raúl E; Torres-Rojas, Yassir E; Galván-Magaña, Felipe; Bojórquez-Leyva, Humberto; Páez-Osuna, Federico

    2015-11-01

    Selenium and mercury were evaluated in muscle, liver, kidney, brain, and the stomach contents of juvenile scalloped hammerhead shark Sphyrna lewini. Se:Hg molar ratios were calculated. The average Hg levels in muscle ranged from 0.12 to 1.17 μg/g (wet weight); Hg was <0.39 μg/g in liver and kidneys and <0.19 μg/g in brain. The lowest value of Se was found in muscle (0.4 μg/g) and the highest in kidney (26.7 μg/g). An excess of Se over Hg was found, with Se:Hg molar ratios >1. Correlations were found for Hg in muscle with size, age, and weight, and also for Hg in liver with size, age, and weight. Hg in muscle was significantly positive correlated to Hg in brain as well as Hg in liver was correlated to Hg in kidney. The highest Hg in preys was for carangid fishes; scombrid and carangid fishes contributed with the highest Se levels. Results suggest that more than 98 % of the total Hg and 62 % of Se end up in muscle and might be affected by factors, such as geographical area, age, size, and feeding habits. The muscle of S. lewini should be consumed by people cautiously so as not to exceed the recommended intake per week. PMID:26369650

  11. Effect of dietary alpha-tocopherol, ascorbic acid, selenium, and iron on oxidative stress in sub-yearling Chinook salmon (Oncorhynchus tshawytscha)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A three-variable central composite design coupled with surface-response analysis was used to examine the effects of dietary alpha-tocopherol + ascorbic acid (TOCAA), selenium (Se), and iron (Fe) on indices of oxidative stress in juvenile spring Chinook salmon. Each dietary factor was tested at five ...

  12. Effect of alcohol consumption on selenium (Se) bioavailability in rats

    SciTech Connect

    Cho, H.K.; Snook, J.T.; Yang, F.L.

    1986-03-01

    This study was done to determine the effects of alcohol ingestion on Se bioavailability in initially Se-depleted rats. Weanling male rats were fed a Se deficient (0.012 mg/kg) basal diet for 4 weeks and then for the subsequent 4 weeks were supplemented at 0.031 mg Se/kg or at 0.085 mg Se/kg of diet in the form of high Se yeast. During the Se repletion period alcohol replaced medium chain triglycerides in the diet at 3 levels: 0%, 10%, and 20% of calories. Dietary Se level significantly (P < .0001) affected urinary Se, fecal Se, Se absorption, Se balance, whole blood Se, whole blood glutathione peroxidase activity, and liver Se. In rats fed the higher Se diet total liver Se increased 50% when 20% rather than 0% alcohol was given. In rats fed the lower Se diet total liver Se decreased 12% as dietary alcohol increased from 0 to 20%. There was a significant (P < .0015) interaction between alcohol and Se level. All the other parameters for Se bioavailability were not affected by alcohol consumption. However, alcohol consumption significantly reduced growth rate at both Se levels.

  13. Selenium bioaccessibility and bioavailability in Se-enriched food supplements.

    PubMed

    Thiry, Celine; Schneider, Yves-Jacques; Pussemier, Luc; De Temmerman, Ludwig; Ruttens, Ann

    2013-04-01

    Most European people have selenium (Se) intake inferior to recommended values that are considered necessary to ensure the beneficial action of antioxidant selenoproteins. People could therefore tend to have recourse to Se-enriched food supplements (FS) aiming to increase their Se body level. On the Belgian market, three main types of Se-rich FS are available: Se-enriched yeast, selenate-based FS, and selenite-based FS. In the present work, in vitro tests imitating gastrointestinal digestion and intestinal absorption were used to determine the bioaccessible and bioavailable fractions of Se present in one specimen of each category of FS. The aim of the study was to verify to which extent the difference in Se speciation could influence the efficiency of FS for enhancing the human Se status. Results indicated that differences exist in both bioaccessibility and bioavailability between the three types of FS, and that these differences could be related, at least partially, to the Se species profile. Overall bioavailability of the three FS was low (maximum 14 % of the original Se content). Among the three samples, the selenate-based FS produced the highest fraction of bioavailable Se, followed by Se-yeast, and finally by the selenite-based FS for which Se was almost not available at all. These results confirm the low availability of inorganic Se but were somewhat unexpected regarding the yeast-based FS since Se-rich yeasts are usually reported to contain an important fraction of available Se. PMID:23397356

  14. Dietary selenium increases the antioxidant levels and ATPase activity in the arteries and veins of poultry.

    PubMed

    Cao, Changyu; Zhao, Xia; Fan, Ruifeng; Zhao, Jinxin; Luan, Yilin; Zhang, Ziwei; Xu, Shiwen

    2016-07-01

    Selenium (Se) deficiency is associated with the pathogenesis of vascular diseases. It has been shown that oxidative levels and ATPase activity were involved in Se deficiency diseases in humans and mammals; however, the mechanism by how Se influences the oxidative levels and ATPase activity in the poultry vasculature is unclear. We assessed the effects of dietary Se deficiency on the oxidative stress parameters (superoxide dismutase, catalase, and hydroxyl radical) and ATPase (Na(+)K(+)-ATPase, Ca(++)-ATPase, Mg(++)-ATPase, and Ca(++)Mg(++)-ATPase) activity in broiler poultry. A total of 40 broilers (1-day old) were randomly divided into a Se-deficient group (L group, fed a Se-deficient diet containing 0.08 mg/kg Se) and a control group (C group, fed a diet containing sodium selenite at 0.20 mg/kg Se). Then, arteries and veins were collected following euthanasia when typical symptoms of Se deficiency appeared. Antioxidant indexes and ATPase activity were evaluated using standard assays in arteries and veins. The results indicated that superoxide dismutase activity in the artery according to dietary Se deficiency was significantly lower (p < 0.05) compared with the C group. The catalase activity in the veins and hydroxyl radical inhibition in the arteries and veins by dietary Se deficiency were significantly higher (p < 0.05) compared with the C group. The Se-deficient group showed a significantly lower (p < 0.05) tendency in Na(+)K(+)-ATPase activity, Ca(++)-ATPase activity, and Ca(++)Mg(++)-ATPase activity. There were strong correlations between antioxidant indexes and Ca(++)-ATPase activity. Thus, these results indicate that antioxidant indexes and ATPases may have special roles in broiler artery and vein injuries under Se deficiency. PMID:26637493

  15. The bioaccumulation and effects of selenium in the oligochaete Lumbriculus variegatus via dissolved and dietary exposure routes.

    PubMed

    Xie, Lingtian; Wu, Xing; Chen, Hongxing; Luo, Yongju; Guo, Zhongbao; Mu, Jingli; Blankson, Emmanuel R; Dong, Wu; Klerks, Paul L

    2016-09-01

    Aquatic organisms take up selenium from solution and from their diets. Many questions remain regarding the relative importance of selenium accumulation from these sources and resulting effects in benthic invertebrates. The present study addressed the toxicity and accumulation of Se via dissolved and dietary exposures to three different Se species, in the freshwater oligochaete Lumbriculus variegatus. Worms were exposed to 20μg/g dry weight of selenite (Se(IV)), selenate (Se(VI)), or seleno-l-methionine (Se-Met) in their diet (sediment) or to 15μg/L dissolved Se in water-only exposures. While the dissolved and sediment Se levels differed greatly, such levels may co-occur at a Se-contaminated site. Se accumulation, worm population growth, lipid peroxidation (as TBARS), and Na(+)/K(+)-ATPase activity were quantified at the end of the 2-week exposure. The sediment Se-Met exposure caused 100% mortality, while worm densities were reduced by the other exposures except the Se(VI) one. Se bioaccumulation was generally higher for the sediment-Se exposure than the dissolved-Se ones, and was higher for Se(IV) than Se(VI) in the dissolved-Se exposure but not the sediment-Se one. The Se accumulation was highest for Se-Met. The oligochaetes that accumulated Se had higher levels of lipid peroxidation and reduced Na(+)/K(+)-ATPase activity. The present study's findings of differences in Se accumulation and toxicity for the three Se species, with effects generally but not exclusively a function of Se body burdens, underscore the need for research on these issues in invertebrates. Moreover, the results imply that the dietary uptake route is the predominant one for Se accumulation in L. variegatus. PMID:27450235

  16. Effects of dietary selenium on host response to necrotic enteritis in young broilers.

    PubMed

    Xu, Shouzhen; Lee, Sung-Hyen; Lillehoj, Hyun S; Hong, Yeong Ho; Bravo, David

    2015-02-01

    The effects of dietary supplementation of young broiler chickens with an organic selenium (Se) formulation, B-Traxim Se, on experimental necrotic enteritis (NE) were studied. Chickens treated with three Se doses (0.25, 0.50, 1.00 mg/kg) from hatch were orally challenged with Eimeria maxima at 14 days of age followed by Clostridium perfringens to induce NE. Chickens fed with 0.50 mg/kg Se showed significantly increased body weights and antibody levels against NetB, and significantly reduced gut lesions compared with non-supplemented chickens. However, there were no significant differences in Eimeria oocyst shedding between the Se-treated and non-supplemented groups. Levels of IL-1β, IL-6, IL-8, iNOS, LITAF, TNFSF15, AvBD6, AvBD8, and AvBD13 transcripts were increased in the gut and spleen of at least one of the three Se-treated groups compared with the non-treated group. These results suggest that dietary supplementation of young broilers with Se might be beneficial to reduce the negative consequence of NE. PMID:25575447

  17. Impact of dietary selenium on methylmercury toxicity in juvenile Atlantic cod: a transcriptional survey.

    PubMed

    Olsvik, Pål A; Amlund, Heidi; Sæle, Øystein; Ellingsen, Ståle; Skjaerven, Kaja H

    2015-02-01

    Selenium (Se) and its derivatives are known to have protective effects against mercury (Hg) toxicity in mammals. In this study we wanted to evaluate whether Se co-exposure affect the transcription of methylmercury (MeHg) toxicity-relevant genes in early life stages of fish. Juvenile Atlantic cod were exposed to regular feed (control), Se-spiked feed (3mg Se kg(-1)), MeHg-spiked feed (10mg Hg kg(-1)) or to Se- and MeHg-spiked feed (3mg Se kg(-1) and 10mg Hg kg(-1), respectively) for ten weeks. Liver tissue was harvested for transcriptional analysis when the fish were weighing 11.4 ± 3.2g. Accumulated levels of Hg in liver of the two groups of fish exposed to MeHg were 1.5mg Hg kg(-1) wet weight, or 44-fold higher than in the control group, while the Se concentrations differed with less than 2-fold between the fish groups. Selenium co-exposure had no effect on the accumulated levels of Hg in liver tissue; however, MeHg co-exposure reduced the accumulated level of Se. Dietary exposure to MeHg had no effect on fish growth. Interaction effects between Se and MeHg exposure were observed for the transcriptional levels of CAT, GPX1, GPX3, NFE2L2, UBA52, SEPP1 and DNMT1. Significant effects of MeHg exposure were seen for DNMT1 and PPARG, while effects of Se exposure were seen for GPX4B and SEPP1A, as well as for DNA methyltransferase activity. The transcriptional results suggest, by considering up-regulation as a proxy for negative impact and at the tested concentrations, a pro-oxidative effect of Se co-exposure with MeHg, rather than an antioxidative effect. PMID:25062025

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

    PubMed Central

    Haug, Anna; Eich-Greatorex, Susanne; Bernhoft, Aksel; Wold, Jens P; Hetland, Harald; Christophersen, Olav A; Sogn, Trine

    2007-01-01

    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. PMID:17967172

  19. Effect of dietary selenium levels on methylbenzylnitrosamine-induced esophageal cancer in rats.

    PubMed

    Nauss, K M; Bueche, D; Soule, N; Fu, P; Yew, K; Newberne, P M

    1986-10-01

    Male Sprague-Dawley rats fed selenium deficient diets received either 0 ppm, 0.15 ppm or 4.0 ppm selenium in the drinking water. Animals were treated with methylbenzylnitrosamine (MBN). Dietary selenium deficiency had no effect on MBN-induced esophageal carcinogenesis. Animals treated with 4 ppm selenium in the drinking water during the initiation and post-initiation period had the same number of tumors as the group which received 0.15 ppm selenium for the entire experimental period. The incidence and frequency of carcinomas was lowest in the group which was supplemented with extra selenium (4.0 ppm) during the period of carcinogen administration and highest in the group which received 4.0 ppm selenium during the post-initiation period. PMID:3768858

  20. Effects of dietary selenium supplementation on tissue selenium distribution and glutathione peroxidase activity in Chinese Ring necked Pheasants.

    PubMed

    Juniper, D T; Bertin, G

    2013-04-01

    The objective of this study was to determine the concentration of total selenium (Se) and the proportions of total Se comprised as selenomethionine (SeMet) and selenocysteine (SeCys) in the postmortem tissues of female pheasants (Phasianus Colchicus Torquator) offered diets that contained graded additions of selenised-enriched yeast (SY) or a single comparative dose of sodium selenite (SS). Thiobarbituric acid reactive substances (TBARS) and tissue glutathione peroxidase (GSH-Px) activity of breast (Pectoralis Major) were assessed at 0 and 5 days postmortem. A total of 216 female pheasant chicks were enrolled into the study. Twenty-four birds were euthanased at the start of the study, and samples of blood, breast muscle, leg muscle (M. Peroneus Longus and M. Gastrocnemius), heart, liver, kidney and gizzard were collected for determination of total Se. Remaining birds were blocked by live weight and randomly allocated to one of four dietary treatments (n = 48 birds/treatment) that either differed in Se source (SY v. SS) or dose (control (0.17 mg total Se/kg), SY-L and SS-L (0.3 mg/kg total Se as SY and SS, respectively) and SY-H (0.45 mg total Se/kg)). Following 42 and 91 days of treatment, 24 birds per treatment were euthanased, and samples of blood, breast muscle, leg muscle, heart, liver, kidney and gizzard were retained for determination of total Se and the proportion of total Se comprised as SeMet or SeCys. Whole blood GSH-Px activity was determined at each time point. Tissue GSH-Px activity and TBARS were determined in breast tissue at the end of the study. There were increases in both blood and tissues to the graded addition of SY to the diet (P < 0.001), but the same responses were not apparent with the blood and tissues of selenite-supplemented birds receiving a comparable dose (SY-L v. SS-L). Although there were differences between tissue types in the distribution of SeMet and SeCys, there were few differences between treatments. There were effects of

  1. Dietary Selenium in Adjuvant Therapy of Viral and Bacterial Infections12

    PubMed Central

    Steinbrenner, Holger; Al-Quraishy, Saleh; Dkhil, Mohamed A; Wunderlich, Frank; Sies, Helmut

    2015-01-01

    Viral and bacterial infections are often associated with deficiencies in macronutrients and micronutrients, including the essential trace element selenium. In selenium deficiency, benign strains of Coxsackie and influenza viruses can mutate to highly pathogenic strains. Dietary supplementation to provide adequate or supranutritional selenium supply has been proposed to confer health benefits for patients suffering from some viral diseases, most notably with respect to HIV and influenza A virus (IAV) infections. In addition, selenium-containing multimicronutrient supplements improved several clinical and lifestyle variables in patients coinfected with HIV and Mycobacterium tuberculosis. Selenium status may affect the function of cells of both adaptive and innate immunity. Supranutritional selenium promotes proliferation and favors differentiation of naive CD4-positive T lymphocytes toward T helper 1 cells, thus supporting the acute cellular immune response, whereas excessive activation of the immune system and ensuing host tissue damage are counteracted through directing macrophages toward the M2 phenotype. This review provides an up-to-date overview on selenium in infectious diseases caused by viruses (e.g., HIV, IAV, hepatitis C virus, poliovirus, West Nile virus) and bacteria (e.g., M. tuberculosis, Helicobacter pylori). Data from epidemiologic studies and intervention trials, with selenium alone or in combination with other micronutrients, and animal experiments are discussed against the background of dietary selenium requirements to alter immune functions. PMID:25593145

  2. Genetic adaptation to levels of dietary selenium in recent human history.

    PubMed

    White, Louise; Romagné, Frédéric; Müller, Elias; Erlebach, Eva; Weihmann, Antje; Parra, Genís; Andrés, Aida M; Castellano, Sergi

    2015-06-01

    As humans migrated around the world, they came to inhabit environments that differ widely in the soil levels of certain micronutrients, including selenium (Se). Coupled with cultural variation in dietary practices, these migrations have led to a wide range of Se intake levels in populations around the world. Both excess and deficiency of Se in the diet can have adverse health consequences in humans, with severe Se deficiency resulting in diseases of the bone and heart. Se is required by humans mainly due to its function in selenoproteins, which contain the amino acid selenocysteine as one of their constituent residues. To understand the evolution of the use of this micronutrient in humans, we surveyed the patterns of polymorphism in all selenoprotein genes and genes involved in their regulation in 50 human populations. We find that single nucleotide polymorphisms from populations in Asia, particularly in populations living in the extreme Se-deficient regions of China, have experienced concerted shifts in their allele frequencies. Such differentiation in allele frequencies across genes is not observed in other regions of the world and is not expected under neutral evolution, being better explained by the action of recent positive selection. Thus, recent changes in the use and regulation of Se may harbor the genetic adaptations that helped humans inhabit environments that do not provide adequate levels of Se in the diet. PMID:25739735

  3. Effects of dietary supplementation of selenium and iodine on growth performance, carcass characteristics and histology of thyroid gland in goats.

    PubMed

    Aghwan, Zeiad Amjad; Sazili, Awis Qurni; Kadhim, Khalid Kamil; Alimon, Abdul Razak; Goh, Yong Meng; Adeyemi, Kazeem Dauda

    2016-05-01

    This study assessed the effects of dietary selenium (Se), iodine (I) and a combination of both on growth performance, thyroid gland activity, carcass characteristics and the concentration of iodine and selenium in Longissimus lumborum (LL) muscle in goats. Twenty-four bucks were randomly assigned to four dietary treatments: control (CON), basal diet without supplementation, basal diet + 0.6 mg Se/kg dry matter (DM) (SS), 0.6 mg I/kg DM (IP), or combination of 0.6 mg/kg DM Se and 0.6 mg/kg DM I (SSIP) and fed for 100 days. Animals fed diet SSIP exhibited higher (P < 0.05) body weight and better feed conversion ratio (FCR) than those fed other diets. Dressing percentage of goats fed the supplemented diets was higher (P < 0.05) than that of the control. Carcasses from the IP group had higher (P < 0.05) total fat proportion than the SSIP group. The levels of both elements were significantly elevated (P < 0.05) in LL muscle in supplemented goats. Thyroid follicular epithelial cells of IP and SSIP animals were significantly higher than those of CON and SS groups. The study demonstrated that the combined Se and I dietary supplementation improves growth performance, carcass dressing percentage and increases the retention of Se and I in goat meat. PMID:26560071

  4. Effect of dietary organic selenium on muscle proteolytic activity and water-holding capacity in pork.

    PubMed

    Calvo, L; Toldrá, F; Aristoy, M C; López-Bote, C J; Rey, A I

    2016-11-01

    This study evaluates the effect of dietary selenium (Se) supplementation source (organic, Se-enriched yeast; SY vs. inorganic, sodium selenite; SS), dose (0.2: L vs. 0.4: H mg/kg) and the combination of Se and vitamin E (VITE+SS) for 26days on drip loss, TBARS, colour changes, myofibrillar protein pattern and proteolysis in pork. The lowest water losses were observed in the SY-H group when compared to the others. SY-H and VITE+SS groups presented lower myofibrillar protein hydrolysis/oxidation. VITE+SS supplementation also resulted in higher PRO, TRP and PHE content at days 2 and 7, whereas the SY group showed increased GLY and CAR and tended to have higher TAU and ANS at day 2. The myofibrillar fragmentation index was not modified by the dietary treatment; however, at day 8, it tended to be higher in groups supplemented with SeY and VITE+SS. The results of the present study might indicate a possible relation between muscle proteolysis and water loss. PMID:27232379

  5. Electroded avalanche amorphous selenium (a-Se) photosensor

    PubMed Central

    Bubon, Oleksandr; DeCrescenzo, Giovanni; Zhao, Wei; Ohkawa, Yuji; Miyakawa, Kazunori; Matsubara, Tomoki; Kikuchi, Kenji; Tanioka, Kenkichi; Kubota, Misao; Rowlands, John A.; Reznik, Alla

    2012-01-01

    Although avalanche amorphous selenium (a-Se) is a very promising photoconductor for a variety of imaging applications, it is currently restricted to applications with electron beam readout in vacuum pick-up tube called a High-gain Avalanche Rushing Photoconductor (HARP). The electron beam readout is compatible with high definition television (HDTV) applications, but for use in solid-state medical imaging devices it should be replaced by an electronic readout with a two-dimensional array of metal pixel electrodes. However, due to the high electric field required for avalanche multiplication, it is a technological challenge to avoid possible dielectric breakdown at the edges, where electric field experiences local enhancement. It has been shown recently that this problem can be overcome by the use of a Resistive Interface Layer (RIL) deposited between a-Se and the metal electrode, however, at that time, at a sacrifice in transport properties. Here we show that optimization of RIL deposition technique allows for electroded avalanche a-Se with transport properties and time performance previously not achievable with any other a-Se structures. We have demonstrated this by detailed analysis of transport properties performed by Time-of-Flight (TOF) technique. Our results showed that a stable gain of 200 is reached at 104 V/μm for a 15-μm thick a-Se layer, which is the maximum theoretical gain for this thickness. We conclude that RIL is an enabling technology for practical implementation of solid-state avalanche a-Se image sensors. PMID:23115545

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. The importance of pyridoxine for the impact of the dietary selenium sources on redox balance, embryo development, and reproductive performance in gilts.

    PubMed

    Dalto, Danyel Bueno; Audet, Isabelle; Lapointe, Jérôme; Matte, J Jacques

    2016-03-01

    This study aimed to determine the effects of dietary pyridoxine and selenium (Se) on embryo development, reproductive performance and redox system in gilts. Eighty-four gilts were fed one of five diets: CONT) basal diet; MSeB60) CONT+0.3mg/kg of Na-selenite; MSeB610) diet 2+10mg/kg of HCl-pyridoxine; OSeB60) CONT+0.3mg/kg of Se-enriched yeast; and OSeB610) diet 4+10mg/kg of HCl-pyridoxine. Blood samples were collected for long-term (each estrus and slaughter) and peri-estrus (fourth estrus d -4 to d +3) profiles. At slaughter (gestation d 30), organs and embryos were collected. For long-term and peri-estrus profiles, Se level and source affected (P<0.01) blood Se concentration whereas B6 level increased (P<0.01) erythrocyte pyridoxal-5-phosphate concentration. A B6 level (P<0.05) effect was observed on long-term plasma Se-dependent glutathione peroxidase (Se-GPX) activity whereas peri-estrus Se-GPX was minimum on d -1 (P<0.01). Selenium level increased sows' organs and embryo Se concentration (P<0.01). Selenium source tended to enhance embryo Se content (P=0.06). Within-litter embryo Se content was increased by B6 level (P<0.01). Selenium level tended to affect Se-GPX and total GPX activities in organs mitochondria (P=0.09 and 0.07, respectively). Selenium source affected kidney ATP synthesis (P=0.05). In conclusion, B6 level affected the Se-GPX activity on a long-term basis, whereas the basal level of Se was adequate during the peri-estrus period. Embryo quality was not improved by dietary Se, and B6 impaired within-litter homogeneity. PMID:26854249

  8. Maize grain and soil surveys reveal suboptimal dietary selenium intake is widespread in Malawi

    PubMed Central

    Chilimba, Allan D. C.; Young, Scott D.; Black, Colin R.; Rogerson, Katie B.; Ander, E. Louise; Watts, Michael J.; Lammel, Joachim; Broadley, Martin R.

    2011-01-01

    Selenium is an essential element in human diets but the risk of suboptimal intake increases where food choices are narrow. Here we show that suboptimal dietary intake (i.e. 20–30 µg Se person−1 d−1) is widespread in Malawi, based on a spatial integration of Se concentrations of maize (Zea mays L.) grain and soil surveys for 88 field sites, representing 10 primary soil types and >75% of the national land area. The median maize grain Se concentration was 0.019 mg kg−1 (range 0.005–0.533), a mean intake of 6.7 µg Se person−1 d−1 from maize flour based on national consumption patterns. Maize grain Se concentration was up to 10-fold higher in crops grown on soils with naturally high pH (>6.5) (Eutric Vertisols). Under these less acidic conditions, Se becomes considerably more available to plants due to the greater solubility of Se(IV) species and oxidation to Se(VI). PMID:22355591

  9. Selenium accumulation and selenium tolerance of salt grass from soils with elevated concentrations of Se and salinity

    SciTech Connect

    Wu, L.; Huang, Z.Z. )

    1991-12-01

    Biomass production, selenium accumulation, and the role of the bioextraction of selenium by salt grass (Distichlis spicata L.) in soils with elevated concentrations of Se and salinity at Kesterson, California, were studied. Salt grass contributed more than 80% vegetative coverage and 90% dry weight in the grassland communities where the soil Se concentrations were 100 times (1000 to 3000 micrograms kg-1) higher than the Se concentrations found in soils of the control sites. No evidence for evolution of Se tolerance was found in the salt grass populations. The successful colonization of salt grass in the soil with elevated Se and salinity is attributable to the presence of high concentrations of soil sulfate. Salt grass accumulated less Se than other salt-tolerant plant species existing in the same area, and no predation of animals and insects on salt grass has been noticed. Salt grass can transpire substantial amounts of volatile Se through its plant tissue. Under field conditions, a 1-m2 salt grass plot may produce 180 micrograms volatile selenium per day. However, no reduction of soil Se concentration in the salt grass habitat was detected over a period of 1 year. A long-term monitoring of Se status is needed in order to make predictions of the effectiveness of efforts to clean up Se-contaminated soils through the use of native plant species.

  10. Selenium accumulation and selenium tolerance of salt grass from soils with elevated concentrations of Se and salinity.

    PubMed

    Wu, L; Huang, Z Z

    1991-12-01

    Biomass production, selenium accumulation, and the role of the bioextraction of selenium by salt grass (Distichlis spicata L.) in soils with elevated concentrations of Se and salinity at Kesterson, California, were studied. Salt grass contributed more than 80% vegetative coverage and 90% dry weight in the grassland communities where the soil Se concentrations were 100 times (1000 to 3000 micrograms kg-1) higher than the Se concentrations found in soils of the control sites. No evidence for evolution of Se tolerance was found in the salt grass populations. The successful colonization of salt grass in the soil with elevated Se and salinity is attributable to the presence of high concentrations of soil sulfate. Salt grass accumulated less Se than other salt-tolerant plant species existing in the same area, and no predation of animals and insects on salt grass has been noticed. Salt grass can transpire substantial amounts of volatile Se through its plant tissue. Under field conditions, a 1-m2 salt grass plot may produce 180 micrograms volatile selenium per day. However, no reduction of soil Se concentration in the salt grass habitat was detected over a period of 1 year. A long-term monitoring of Se status is needed in order to make predictions of the effectiveness of efforts to clean up Se-contaminated soils through the use of native plant species. PMID:1778115

  11. Copper, iron, zinc, and selenium dietary intake and status of Nepalese lactating women and their breast-fed infants.

    PubMed

    Moser, P B; Reynolds, R D; Acharya, S; Howard, M P; Andon, M B; Lewis, S A

    1988-04-01

    The dietary intake of copper, iron, zinc, and selenium of 26 Nepalese lactating mothers was estimated from chemical analysis of 24-h food and beverage composites. Fasting blood and milk samples were obtained from the mothers and blood samples were obtained from the infants. The Nepalese mothers consumed significantly more Cu, significantly less Fe and Se, and similar amounts of Zn as compared with American lactating women. Blood Fe status indices and plasma concentrations of Cu, Zn, and Se were lower in the Nepalese mothers than in the American mothers. These lower values may in part be related to the high neutral detergent fiber and phytate content of the Nepalese diet, which could make these minerals less available for absorption. The high exposure to infections in Nepal may also depress Fe status indices and plasma Zn concentrations. The lower dietary Se intake of the Nepalese mothers was reflected in lower milk concentrations. PMID:3354498

  12. Selenium

    MedlinePlus

    ... depends on the amount of selenium in the soil where they were grown. The amount of selenium ... raised in many different areas, including areas with soil that is rich in selenium. Certain groups of ...

  13. Effect of selenium and vitamin E dietary deficiencies on chick lymphoid organ development (42361)

    SciTech Connect

    Marsh, J.A.; Combs, G.F. Jr.; Whitacre, M.E.; Dietert, R.R.

    1986-09-01

    Diets specifically deficient in selenium (Se) and/or vitamin E or adequate in both nutrients were fed to chicks from the time of hatching. Lymphoid organs (bursa, thymus, and in some instances, spleen) were collected from chicks 7-35 days of age. Growth of the chicks fed these diets was monitored over the experimental period as was lymphoid organ growth. The development of the primary lymphoid organs was further assessed by histological techniques and the organ contents of vitamin E (..cap alpha..-tocopherol) and Se were determined. Specific deficiencies of either Se or vitamin E were found to significantly impair bursal growth as did a combined deficiency. Thymic growth was impaired only by the combined deficiency diet. Severe histopathological changes in the bursa resulted from the combined deficiency and these were detectable by 10-14 days after hatching. These changes were characterized by a gradual degeneration of the epithelium and an accompanying depletion of lymphocytes. Similar changes, although slower to develop and less severe, were observed in the thymus as a result of the combined deficiency. When both serum and tissue levels of vitamin E and Se were monitored, it was observed that these were rapidly and independently depleted by the specific deficiency diets. These data suggest that the primary lymphoid organs are major targets of Se and vitamin E dietary deficiencies and provide a possible mechanism by which immune function may be impaired.

  14. Effects of selenium dietary enhancement on hatchery-reared coho salmon, Oncorhynchus kisutch (Walbaum), when compared with wild coho: hepatic enzymes and seawater adaptation evaluated.

    USGS Publications Warehouse

    Felton, S.P.; Landolt, M.L.; Grace, R.; Palmisano, A.N.

    1996-01-01

    Hatchery-reared coho salmon, Oncorhynchus kisutch (Walbaum), were fed elevated levels of selenium (as Na2SeO3) to raise eviscerated body burdens to the level measured in wild counterparts. The goal was to find a dietary concentration that would achieve the desired effect without causing damage to growth and normal development. To measure some indices of health, the detoxifying enzymes chosen were hepatic glutathione peroxidase (GSH-Px) and hepatic superoxide dismutase (SOD). Eviscerated body selenium (Se) concentration, GSH-Px and SOD levels were measured during and at the end of the 9 month freshwater feeding trial. Selenium retention and enzyme activity were also measured during 6 months’residence in sea water (SW). Selenium supplements were added to a commercial ration to give final concentrations of 1.1, 8.6, 11.1, 13.6 μg g-1 Se in the four respective diets. The results indicated that a dietary concentration of 8.6 μg g-1selenium was capable of inducing eviscerated body burdens similar to those found in wild fish. The elevated selenium levels persisted throughout the freshwater (FW) rearing phase, but declined when the fish were fed an unsupplemented ration upon SW entry. Superoxide dismutase levels did not increase above control levels. Glutathione peroxidase levels increased in fish fed the supplemented diets. GSH-Px activity declined in the higher supplemented dietary groups when all groups were reduced to the control group level of 1.1 μg g-1. Cumulative mortality in SW was 20% in fish fed either the 1.1 or the 8.6 μg g-1 Se diets. The 8.6 μg g-1 Se supplemented diets did produce healthy coho, comparable to their wild counterparts.

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

    PubMed Central

    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

  16. Dietary Selenium Supplementation Modulates Growth of Brain Metastatic Tumors and Changes the Expression of Adhesion Molecules in Brain Microvessels.

    PubMed

    Wrobel, Jagoda K; Wolff, Gretchen; Xiao, Rijin; Power, Ronan F; Toborek, Michal

    2016-08-01

    Various dietary agents can modulate tumor invasiveness. The current study explored whether selenoglycoproteins (SeGPs) extracted from selenium-enriched yeast affect tumor cell homing and growth in the brain. Mice were fed diets enriched with specific SeGPs (SeGP40 or SeGP65, 1 mg/kg Se each), glycoproteins (GP40 or GP65, 0.2-0.3 mg/kg Se each) or a control diet (0.2-0.3 mg/kg Se) for 12 weeks. Then, murine Lewis lung carcinoma cells were infused into the brain circulation. Analyses were performed at early (48 h) and late stages (3 weeks) post tumor cell infusion. Imaging of tumor progression in the brain revealed that mice fed SeGP65-enriched diet displayed diminished metastatic tumor growth, fewer extravasating tumor cells and smaller metastatic lesions. While administration of tumor cells resulted in a significant upregulation of adhesion molecules in the early stage of tumor progression, overexpression of VCAM-1 (vascular call adhesion molecule-1) and ALCAM (activated leukocyte cell adhesion molecule) messenger RNA (mRNA) was diminished in SeGP65 supplemented mice. Additionally, mice fed SeGP65 showed decreased expression of acetylated NF-κB p65, 48 h post tumor cell infusion. The results indicate that tumor progression in the brain can be modulated by specific SeGPs. Selenium-containing compounds were more effective than their glycoprotein controls, implicating selenium as a potential negative regulator of metastatic process. PMID:26706037

  17. Cu(In,Ga)Se 2 thin-film solar cells grown with cracked selenium

    NASA Astrophysics Data System (ADS)

    Kawamura, Masahiro; Fujita, Toshiyuki; Yamada, Akira; Konagai, Makoto

    2009-01-01

    Cu(In 1-xGa x)Se 2 (CIGS) films have been grown by using cracked selenium. In conventional evaporation system, the Se atoms were supplied as large clusters (Se x, x>5). However, the size of clusters can be reduced by the thermal cracking. The film qualities grown with small clusters (Se x, x<4) would be improved, since the smaller size molecules easily react with elemental metals, resulting in the reduction of selenium vacancies and the enhancement of surface migration. The CIGS films were deposited by the three-stage method with cracked selenium, and the films were evaluated by SEM, XRD, EDX, C- V measurement and admittance spectroscopy. It was found from the C- V characteristics that the carrier concentrations of the CIGS films grown with cracked selenium were increased with increasing the cracking temperature. The result clearly showed that the use of cracked selenium was effective for reduction of selenium vacancies. The conversion efficiency of 15.4% was obtained by using cracked selenium at a cracking temperature of 500 °C.

  18. Dietary Selenium as a Modulator of PCB 126–Induced Hepatotoxicity in Male Sprague-Dawley Rats

    PubMed Central

    Lai, Ian K.; Chai, Yingtao; Simmons, Donald; Watson, Walter H.; Tan, Rommel; Haschek, Wanda M.; Wang, Kai; Wang, Bingxuan; Ludewig, Gabriele; Robertson, Larry W.

    2011-01-01

    Homeostasis of selenium (Se), a critical antioxidant incorporated into amino acids and enzymes, is disrupted by exposure to aryl hydrocarbon receptor (AhR) agonists. Here we examined the importance of dietary Se in preventing the toxicity of the most toxic polychlorinated biphenyl congener, 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126), a potent AhR agonist. Male Sprague-Dawley rats were fed a modified AIN-93 diet with differing dietary Se levels (0.02, 0.2, and 2 ppm). Following 3 weeks of acclimatization, rats from each dietary group were given a single ip injection of corn oil (vehicle), 0.2, 1, or 5 μmol/kg body weight PCB 126, followed 2 weeks later by euthanasia. PCB exposure caused dose-dependent increases in liver weight and at the highest PCB 126 dose decreases in whole body weight gains. Hepatic cytochrome P-450 (CYP1A1) activity was significantly increased even at the lowest dose of PCB 126, indicating potent AhR activation. PCB exposure diminished hepatic Se levels in a dose-dependent manner, and this was accompanied by diminished Se-dependent glutathione peroxidase activity. Both these effects were partially mitigated by Se supplementation. Conversely, thioredoxin (Trx) reductase activity and Trx oxidation state, although significantly diminished in the lowest dietary Se groups, were not affected by PCB exposure. In addition, PCB 126–induced changes in hepatic copper, iron, manganese, and zinc were observed. These results demonstrate that supplemental dietary Se was not able to completely prevent the toxicity caused by PCB 126 but was able to increase moderately the levels of several key antioxidants, thereby maintaining them roughly at normal levels. PMID:21865291

  19. Solid state 77Se NMR investigations on arsenic-selenium glasses and crystals

    NASA Astrophysics Data System (ADS)

    Bureau, Bruno; Troles, Johann; LeFloch, Marie; Smektala, Frédéric; Silly, Gilles; Lucas, Jacques

    2003-01-01

    Some resolved solid state 77Se NMR spectra are presented in the As xSe 1- x glass family at ambient temperature. They exhibit three different kinds of Se environments. A comparison with the parent crystalline phases permits to assign the lines to Se- Se-Se, Se- Se-As and As- Se-As Se atom neighborhoods. The measurements of the relative intensities of the lines prove the validity of the intermediate range order structural model known as the "chains crossing model" which is based on AsSe 3 pyramids homogeneously distributed among the divalent Se atoms network. In particular, any scenario involving a selenium clustering process is refuted.

  20. Diagnostic criteria for selenium toxicosis in aquatic birds: dietary exposure, tissue concentrations, and macroscopic effects.

    PubMed

    Albers, P H; Green, D E; Sanderson, C J

    1996-07-01

    A feeding study with mallard ducks (Anas platyrhynchos) was conducted during March to July 1988 in Laurel, Maryland (USA), to identify diagnostic criteria for selenium toxicosis in birds. One-year-old male mallards in groups of 21 were fed diets containing 0, 10, 20, 40, or 80 parts per million (ppm) selenium, as seleno-DL-methionine, for 16 weeks. All ducks receiving 80 ppm died. Ducks receiving 40 or 80 ppm selenium consumed less feed than ducks in the other treatment groups. Body weights of ducks receiving 40 or 80 ppm selenium declined during the study. The post-breeding molt was delayed in ducks receiving 40 ppm; most ducks receiving 80 ppm selenium died prior to the onset of molt. At necropsy, numerous abnormalities were observed in ducks that died but only a small number of abnormalities were observed in ducks surviving to the end of the study in the 40 ppm group. Weights of the heart, spleen, and pancreas were mostly lower and weights of the kidney were higher for ducks dying during the study than for euthanized ducks. Liver weights were unaffected. Selenium accumulated in soft tissues approximately in proportion to dietary concentrations. Selenium concentrations in tissues of all ducks that died were different from those of surviving ducks in the 0, 10, and 20 ppm groups, but were not different from those of surviving ducks in the 40 ppm group. Proposed diagnostic criteria for fatal chronic selenosis were derived from body weight, macroscopic abnormalities, organ weights, and concentrations of selenium in the liver. Proposed diagnostic criteria for non-fatal chronic selenosis were derived from body weight, plumage condition, macroscopic abnormalities, concentrations of selenium in the liver, reproductive failure, and alterations of blood and tissue chemistries. Lead or dioxin poisoning have diagnostic criteria most similar to selenium toxicosis. PMID:8827673

  1. Diagnostic criteria for selenium toxicosis in aquatic birds: dietary exposure, tissue concentrations, and macroscopic effects

    USGS Publications Warehouse

    Albers, P.H.; Green, D.E.; Sanderson, C.J.

    1996-01-01

    A feeding study with mallard ducks (Anas platyrhynchos) was conducted during March-July, 1988 in Laurel, Maryland, to identify diagnostic criteria for selenium toxicosis in birds. One-year-old male mallards in groups of 21 were fed diets containing 0, 10, 20, 40, or 80 parts per million (ppm) selenium, as seleno-DL-methionine, for 16 weeks. All ducks receiving 80 ppm died. Ducks receiving 40 or 80 ppm selenium consumed less feed than ducks in the other treatment groups. Body weights of ducks receiving 40 or 80 ppm selenium declined during the study. The post-breeding molt was delayed in ducks receiving 40 ppm; most ducks receiving 80 ppm selenium died prior to the onset of molt. At necropsy, numerous abnormalities were observed in ducks that died but only a small number of abnormalities were observed in ducks surviving to the end of the study in the 40 ppm group. Weights of the heart, spleen, and pancreas were mostly lower and weights of the kidney were higher for ducks dying during the study than for euthanized ducks. Liver weights were unaffected. Selenium accumulated in soft tissues approximately in proportion to dietary concentrations. Selenium concentrations in tissues of all ducks that died were different from those of surviving ducks in the 0, 10, and 20 ppm groups, but were not different from those of surviving ducks in the 40 ppm group. Proposed diagnostic criteria for fatal chronic selenosis were derived from body weight, macroscopic abnormalities, organ weights, and concentrations of selenium in the liver. Proposed diagnostic criteria for non-fatal chronic selenosis were derived from body weight, plumage condition, macroscopic abnormalities, concentrations of selenium in the liver, reproductive failure, and alterations of blood and tissue chemistries. Lead or dioxin poisoning have diagnostic criteria most similar to selenium toxicosis.

  2. The effects of Selenocysteine Se-Methyltransferase on Selenium metabolism in Broccoli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) plays an indispensable role in human nutrition and has suggested to have important health benefits, including as a cancer preventative agent. Se-methylselenocysteine, a monomethylated form of Se, has been shown to be one of the most effective chemopreventative compounds. Broccoli is ...

  3. THE EFFECTS OF SELENOCYSTEINE SE-METHYLTRANSFERASE ON SELENIUM METABOLISM IN TRANSGENIC BROCCOLI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) plays an indispensable role in human nutrition and has been implicated to have important health benefits, including being a cancer preventative agent. Se-methylselenocysteine, a monomethylated form of Se, has been shown to be one of the most effective chemopreventative compounds. Bro...

  4. Methanococcus vannielii selenium-binding protein (SeBP): Chemical reactivity of recombinant SeBP produced in Escherichia coli

    PubMed Central

    Patteson, Kemberly G.; Trivedi, Neel; Stadtman, Thressa C.

    2005-01-01

    A selenium-binding protein (SeBP) from Methanococcus vannielii was recently identified, and its gene was isolated and overexpressed in Escherichia coli [Self, W. T., Pierce, R. & Stadtman, T. C. (2004) IUBMB Life 56, 501–507]. SeBP and recombinant SeBP (rSeBP) migrated as ≈42-kDa species on native gels and as ≈33-kDa species on SDS gels. rSeBP consists of identical 8.8-kDa subunits, each containing a single cysteine residue. rSeBP isolated in the absence of reducing agents contained oxidized cysteine (89%) and very little bound selenium (0.05 eq or less per subunit). Complete reduction of the oxidized cysteine residues in rSeBP with Tris(2-carboxyethyl)phosphine required addition of a denaturant, such as 1 M guanidine-hydrochloride. With selenite as the selenium source and the isolated reduced protein as sole reductant, binding of one selenium per tetramer under anaerobic conditions required four cysteine thiol groups, one on each subunit. In the corresponding reaction, with reduced glutathione (GSH), equimolar amounts of selenodiglutathione (GSSeSG) and glutathione disulfide are formed from selenite and 4 GSH. At GSH-to-selenite ratios >4:1, conversion of GSSeSG to a perselenide derivative, GSSe–, occurs. However, with the reduced rSeBP as sole electron donor in the reaction with selenite, further conversion of the R-SSeS-R product apparently did not occur. Prior alkylation of the cysteine thiol groups in reduced rSeBP prevented selenite reduction and selenium binding under comparable conditions. PMID:16103372

  5. Effect of Dietary Selenium Deficiency on the Cell Apoptosis and the Level of Thyroid Hormones in Chicken.

    PubMed

    Huang, Yunmao; Li, Wanyan; Xu, Danning; Li, Bingxin; Tian, Yunbo; Zan, Linsen

    2016-06-01

    This study assessed the effect of dietary selenium (Se) deficiency on male reproductive function in chicken. A total of 180 Hy-line laying cocks (1 day old; Weiwei) were randomly divided into 2 groups (n = 90) of Se-deficient chickens and control chickens. The control group was fed a basic diet (containing 0.15 mg of Se/kg). The Se-deficient group was fed a Se-deficient corn-soy basal diet (containing 0.033 mg of Se/kg). Fifteen chickens were killed in each group on days 30, 60, and 90, respectively. Then, serum and testes were collected and used in the detection of experimental index. Results indicated that GSH-Px activity and Bcl-2 mRNA level in the testes and thyroidal triiodothyronine (T3) and free triiodothyronine (FT3) levels in serum by dietary Se deficiency were significantly decreased compared to the corresponding control groups. Se deficiency-treated group showed a significant increase in MDA concent, TUNEL-positive cells, and mRNA level of Bax, Caspase3, and p53 in the testes and thyroidal thyroxine (T4), free thyroxine (FT4), and thyroid-stimulating hormone (TSH) levels in serum. Histopathologically, Se deficiency caused impairments in the testes. These results suggested that dietary Se deficiency exerts significant harmful effects on male reproductive organ and that the intrinsic and extrinsic pathways and the upstream regulators such as p53, Bax, and Bcl-2 were all involved in Se deficiency-induced testicular apoptosis. PMID:26507440

  6. Influence of dietary fat and selenium fed during initiation or promotion on the development of preneoplastic lesions in rat liver

    SciTech Connect

    Baldwin, S.; Parker, R.S.

    1986-03-05

    Aflatoxin B/sub 1/ (AFB1)-induced ..gamma..-glutamyl transpeptidase (GGT)-positive foci in rat liver were assessed in animals fed different levels of fat and selenium (Se) during either initiation (IN) or promotion (PR). Male Sprague Dawley rats (50g) were divided into 12 groups. One of six modified AIN-76 experimental diets were fed to groups 1-6 during weeks 1-4.5 (IN) and to groups 7-12 during weeks 4.5-15 (PR). During weeks 3-4, 13 rats/group received 10 daily doses of AFB1 (.4 mg/kg bwt/dose, i.g.). Two levels of corn oil (2% and 20%) were fed, each containing 3 levels of Se: < 0.02; 0.15; 2.5 (IN) or 1.9 (PR) ppm. When not fed the experimental diets rats were fed a standard AIN-76 diet. In groups 1-6, 0.03% phenobarbital was added to the standard diet. At week 15 rats were sacrificed. Compared to all low-fat groups, the high-fat diets with either < 0.02 or 0.15 ppm Se fed during IN resulted in a marked increase in mean diameter of GGT-positive foci and % liver section occupied by foci. In rats fed high-fat 2.5 ppm Se, preneoplastic development was decreased below all low-fat groups. During PR, Se status but not dietary fat level influenced foci formation. Rats fed < 0.02 ppm Se had greater mean diameter of foci and % section occupied by foci than either 0.15 or 1.9 ppm Se. Thus, an interaction was observed between dietary fat and selenium during IN, but not during PR.

  7. The Effect on Selenium Concentrations of a Randomized Intervention with Fish and Mussels in a Population with Relatively Low Habitual Dietary Selenium Intake

    PubMed Central

    Outzen, Malene; Tjønneland, Anne; Larsen, Erik H.; Andersen, Klaus K.; Christensen, Jane; Overvad, Kim; Olsen, Anja

    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/week for 26 weeks (~50 μg selenium/day). Controls received no intervention. Non-fasting blood samples were taken and whole blood selenium was determined using inductively coupled plasma-mass spectrometry (ICP-MS), and plasma selenoprotein P (SelP) was determined by high performance liquid chromatography coupled to ICP-MS. All available observations were included in linear multiple regression analysis to evaluate the effect of the intervention. The difference in mean change for intervention compared with control persons was 14.9 ng/mL (95% CI: 10.2, 19.7) for whole blood selenium, and 7.0 ng/mL (95% CI: 3.1, 10.9) for plasma SelP (Weeks 0–26). Selenium concentrations were significantly increased after 26 weeks of intervention, albeit to a lower degree than expected. PMID:25599275

  8. Effects of dietary factors on selenium levels of children to prevent Kashin-Beck disease during a high-prevalence period in an endemic area: a cohort study.

    PubMed

    Ning, Y J; Wang, X; Ren, L; Guo, X

    2013-06-01

    Selenium (Se) supplements have been used to control Kashin-Beck disease (KBD) for decades, but the effect of diet without Se supplements is unclear because the prevalence of KBD has decreased. This matched cohort study was undertaken to determine dietary factors affecting selenium nutrition status of children living in KBD areas and the effects of Se supplements in preventing KBD. A total of 593 children aged 5-12 years were randomly selected during the high prevalence period of KBD from 1992 to 1995. Children in one village received Se supplemented (Se+) salt and were matched with three children in 16 other villages who did not receive Se supplemented (Se-) salt. A questionnaire and determinations of occipital hair Se to reflect body Se status were obtained at baseline (April 1992), at 6 months (October 1992), and yearly each April through 1995. Hair Se content in the Se+ group was significantly higher than in the Se- group (P < 0.001) at all time-points and was significantly related to the incidence of suspected KBD symptoms (P = 0.018). Four dietary factors significantly affected hair Se contents. Se levels were increased by consumption of Se+ salt (P < 0.001) and eating meat/egg often (P = 0.019) or occasionally (P = 0.001). Se levels were decreased by consumption of grain mildewed at harvest or in storage (P < 0.001 for each) and drinking ditch, river, or cellar water (P < 0.001; P = 0.002; P < 0.001, respectively). These results show that Se+ salt had a significant effect in maintaining the Se nutrition status of children in this cohort study but that dietary factors in those without Se supplements contributed as well. PMID:23568712

  9. Characterization of high-quality Bi2Se3 films grown using a selenium cracker source

    NASA Astrophysics Data System (ADS)

    Ginley, Theresa; Law, Stephanie

    Topological insulators, including Bi2Se3, are becoming increasingly prevalent in research due to their unique electronic properties--these materials exhibit an insulating bulk but conducting surfaces with electron spin-momentum locking. Using Molecular Beam Epitaxy (MBE) it is possible to grow high-quality thin films of Bi2Se3. Yet these films have not lived up to their potential, in part due to significant bulk conductivity arising from material defects like selenium vacancies. Current MBE growth methods for Bi2Se3 use standard selenium sources that evaporate large selenium molecules which must then be cracked into smaller molecules to be incorporated into the film. This process is inefficient and requires very high fluxes of selenium for good quality growths. However, using a selenium cracking source results in the evaporation of monomers and dimers, facilitating incorporation into the film. We will present electrical, structural, and optical measurements demonstrating that the use of a cracker source allows films to be grown using much lower selenium:bismuth flux ratios with good mobility and low carrier density. T. G. and S. L. gratefully acknowledge funding from the University of Delaware Research Foundation Grant 15A00862.

  10. Selenium from dietary sources and motor functions in the Brazilian Amazon.

    PubMed

    Lemire, Mélanie; Fillion, Myriam; Frenette, Benoît; Passos, Carlos José Sousa; Guimarães, Jean Rémy Davée; Barbosa, Fernando; Mergler, Donna

    2011-12-01

    Selenium (Se) is a well-known anti-oxidant with a critical role in the proper functioning of nervous and muscle functions. Se deficiency has been associated with both cognitive and neuromotor impairment, while sensory and motor deficits have been attributed to excess Se. In the Lower Tapajós Region of the Brazilian Amazon, riverside populations present a wide range of Se levels. These fish-eating communities have among the highest mercury (Hg) exposures reported in the world today, and recently, lead (Pb) exposure has been identified. Some studies suggest that Se intake can be protective for Hg and/or Pb toxicity, however, data from animal and human studies are inconsistent. The objective of the present study was to examine the relations between biomarkers of Se and motor functions, taking into account co-variables and biomarkers of exposure to Hg and Pb. Participants (n=448), aged 15-87 y, were recruited from 12 communities along the Tapajós River. Se concentrations were measured in whole blood (B-Se), plasma (P-Se), hair (H-Se) and urine (U-Se) by ICP-MS. Whole blood Hg (B-Hg) and Pb (B-Pb) were also measured by ICP-MS. Interview-administered questionnaires served to collect information on socio-demographics and medical history. All participants underwent a complete visual examination and performed tests of motor functions (Branches Alternate Movement Task, Santa Ana Test, Dynamometer and Grooved Pegboard Test). B-Se varied from 103 to 1500 μg/L (median 228 μg/L), P-Se from 53.6 to 913 μg/L (median 135 μg/L), H-Se from 0.4 to 3.8 μg/g (median 0.7 μg/g) and U-Se from 2.3 to 1375 μg/g cr. (median 33.6 μg/g cr.). Median B-Hg and B-Pb levels were 42.5 μg/L and 113 μg/L respectively. In multivariable analysis, Se biomarkers (log-transformed) were positively related to better performance on all motor tests, taking into account socio-demographic co-variables and B-Hg and B-Pb levels. P-Se consistently showed stronger associations to motor performance

  11. Distribution and reuse of {sup 76}Se-selenosugar in selenium-deficient rats

    SciTech Connect

    Suzuki, Kazuo T. . E-mail: ktsuzuki@p.chiba-u.ac.jp; Somekawa, Layla; Suzuki, Noriyuki

    2006-10-15

    Nutritional selenium compounds are transformed to the common intermediate selenide and then utilized for selenoprotein synthesis or excreted in urine mostly as 1{beta}-methylseleno-N-acetyl-DD-galactosamine (selenosugar). Since the biological significance of selenosugar formation is unknown, we investigated their role in the formation of selenoenzymes in selenium deficiency. Rats were depleted of endogenous natural abundance selenium with a single stable isotope ({sup 82}Se) and then made Se-deficient. {sup 76}Se-Selenosugar was administered intravenously to the rats and their urine, serum, liver, kidneys and testes were subjected to speciation analysis with HPLC inductively coupled argon plasma mass spectrometry. Most {sup 76}Se was recovered in its intact form (approximately 80% of dose) in urine within 1 h. Speciation analysis revealed that residual endogenous natural abundance selenium estimated by {sup 77}Se and {sup 78}Se was negligible and distinct distributions of the labeled {sup 76}Se were detected in the body fluids and organs without interference from the endogenous natural abundance stable isotope. Namely, intact {sup 76}Se-selenosugar was distributed to organs after the injection, and {sup 76}Se was used for selenoprotein synthesis. Oxidation to methylseleninic acid and/or hydrolysis of the selenoacetal group to methylselenol were proposed to the transformation of selenosugar for the reuse. Effective use of an enriched stable isotope as an absolute label in hosts depleted of natural abundance isotopes was discussed for application in tracer experiments.

  12. Synthesis of CdSe quantum dots using selenium dioxide as selenium source and its interaction with pepsin

    NASA Astrophysics Data System (ADS)

    Wang, Yilin; Mo, Yunchuan; Zhou, Liya

    2011-09-01

    A novel method has been developed for the synthesis of thioglycolic acid (TGA)-capped CdSe quantum dots (QDs) in an aqueous medium when selenium dioxide worked as a selenium source and sodium borohydride acted as a reductant. The interaction between CdSe QDs and pepsin was investigated by fluorescence spectroscopy. It was proved that the fluorescence quenching of pepsin by CdSe QDs was mainly a result of the formation of CdSe-pepsin complex. Based on the fluorescence quenching results, the Stern-Volmer quenching constant ( Ksv), binding constant ( KA) and binding sites ( n) were calculated. According to the Foster's non-radiative energy transfer theory, the binding distance ( r) between pepsin and CdSe QDs was obtained. The influence of CdSe QDs on the conformation of pepsin has been analyzed by synchronous fluorescence spectra, which provided that the secondary structure of pepsin has been changed by the interaction of CdSe QDs with pepsin.

  13. Predicted dietary intake of selenium by the general adult population in Belgium.

    PubMed

    Waegeneers, Nadia; Thiry, Céline; De Temmerman, Ludwig; Ruttens, Ann

    2013-01-01

    The total selenium content of about 800 food products purchased in Belgium was determined and combined with food records to determine the nutritional selenium status of Belgian people. The largest selenium concentrations (>1 mg kg(-1)) were found in Brazil nuts and offal, of which the consumption is limited. Usually consumed food groups with the highest selenium concentrations were fish and shellfish (0.2-0.9 mg kg(-1)), eggs, poultry meat, cheese, mushrooms and pasta (approximately 0.2 mg kg(-1)). The mean dietary selenium intake was calculated to be 60 µg day(-1), which is at the lower end but within the range recommended by the Superior Health Council in Belgium (60-70 µg day(-1)), and adequate according to the 55 µg day(-1) recommended by the Scientific Committee on Food (SCF) of the European Commission. The major sources of selenium intake are meat and meat products (31%), fish and shellfish (20%), pasta and rice (12%), and bread and breakfast cereals (11%). PMID:23194404

  14. Dietary Selenium Levels Affect Selenoprotein Expression and Support the Interferon-γ and IL-6 Immune Response Pathways in Mice

    PubMed Central

    Tsuji, Petra A.; Carlson, Bradley A.; Anderson, Christine B.; Seifried, Harold E.; Hatfield, Dolph L.; Howard, Michael T.

    2015-01-01

    Selenium is an essential element that is required to support a number of cellular functions and biochemical pathways. The objective of this study was to examine the effects of reduced dietary selenium levels on gene expression to assess changes in expression of non-selenoprotein genes that may contribute to the physiological consequences of selenium deficiency. Mice were fed diets that were either deficient in selenium or supplemented with selenium in the form of sodium selenite for six weeks. Differences in liver mRNA expression and translation were measured using a combination of ribosome profiling, RNA-Seq, microarrays, and qPCR. Expression levels and translation of mRNAs encoding stress-related selenoproteins were shown to be up-regulated by increased selenium status, as were genes involved in inflammation and response to interferon-γ. Changes in serum cytokine levels were measured which confirmed that interferon-γ, as well as IL-6, were increased in selenium adequate mice. Finally, microarray and qPCR analysis of lung tissue demonstrated that the selenium effects on immune function are not limited to liver. These data are consistent with previous reports indicating that adequate selenium levels can support beneficial immune responses, and further identify the IL-6 and interferon-γ pathways as being responsive to dietary selenium intake. PMID:26258789

  15. Opposing impacts on healthspan and longevity by limiting dietary selenium in Telomere Dysfunctional mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is an essential trace element essential for optimal health. We investigated the role of Se in longevity and healthspan in a mouse model of healthy aging in humans with short telomeres. Telomere shortening is associated with aging, mortality and aging-related diseases. We found that whi...

  16. Is hepatic oxidative stress a main driver of dietary selenium toxicity in white sturgeon (Acipenser transmontanus)?

    PubMed

    Zee, Jenna; Patterson, Sarah; Wiseman, Steve; Hecker, Markus

    2016-11-01

    Most species of sturgeon have experienced significant population declines and poor recruitment over the past decades, leading many, including white sturgeon (Acipenser transmontanus), to be listed as endangered. Reasons for these declines are not yet fully understood but benthic lifestyle, longevity, and delayed sexual maturation likely render sturgeon particularly susceptible to factors such as habitat alteration and contaminant exposures. One contaminant of particular concern to white sturgeon is selenium (Se), especially in its more bioavailable form selenomethionine (SeMet), as it is known to efficiently bioaccumulate in prey items of this species. Studies have shown white sturgeon to be among the most sensitive species of fish to dietary SeMet as well as other pollutants such as metals, dioxin-like chemicals and endocrine disrupters. One of the primary hypothesized mechanisms of toxicity of SeMet in fish is oxidative stress; however, little is know about the specific mode by which SeMet affects the health of white sturgeon. Therefore, the aim of this study was to characterize oxidative stress and associated antioxidant responses as a molecular event of toxicity, and to link it with the pathological effects observed previously. Specifically, three-year-old white sturgeon were exposed for 72 days via their diet to 1.4, 5.6, 22.4 or 104.4µg Se per g feed (dm). Doses were chosen to range over a necessary Se intake level, current environmentally relevant intakes and an intake representing predicted increases of Se release. Lipid hydroperoxides, which are end products of lipid oxidation, were quantified as a marker of oxidative stress. Changes in gene expression of glutathione peroxidase (GPx), superoxide dismutase, catalase, glutathione S-transferase, apoptosis inducing factor and caspase 3 were quantified as markers of the response to oxidative stress. Concentrations of lipid hydroperoxides were highly variable within dose groups and no dose response was observed

  17. Effect of dietary vitamin E or selenium on prostaglandin dehydrogenase in hyperoxic rat lung

    NASA Technical Reports Server (NTRS)

    North, L. N.; Mathias, M. M.; Schatte, C. L.

    1984-01-01

    Weanling male rats were fed semipurified diets supplemented with 0, 60, or 600 IU/kg vitamin E or 0, 100, or 1000 ppb selenium. One group was injected daily with vitamin E at a rate equivalent to consumption of 60 IU/kg. Animals from all groups were sacrificed after exposure to normobaric oxygen or air for 48 h. Lung tissue was analyzed for the combined activity of prostaglandin dehydrogenase and reductase. Using the decline in enzyme activity as an indicator of susceptibility to oxygen poisoning, protection against hyperoxia was directly related to the level of vitamin E supplementation. Selenium supplemented at 100 ppb provided significant protection when compared to 0 ppb or 1000 ppb. The latter dose may have been marginally toxic. Thus dietary supplementation of vitamin E and selenium may influence the relative susceptibility of an animal to pulmonary oxygen poisoning.

  18. Regulation of Selenocysteine Content of Human Selenoprotein P by Dietary Selenium and Insertion of Cysteine in Place of Selenocysteine

    PubMed Central

    Turanov, Anton A.; Everley, Robert A.; Hybsier, Sandra; Renko, Kostja; Schomburg, Lutz; Gygi, Steven P.; Hatfield, Dolph L.; Gladyshev, Vadim N.

    2015-01-01

    Selenoproteins are a unique group of proteins that contain selenium in the form of selenocysteine (Sec) co-translationally inserted in response to a UGA codon with the help of cis- and trans-acting factors. Mammalian selenoproteins contain single Sec residues, with the exception of selenoprotein P (SelP) that has 7–15 Sec residues depending on species. Assessing an individual’s selenium status is important under various pathological conditions, which requires a reliable selenium biomarker. Due to a key role in organismal selenium homeostasis, high Sec content, regulation by dietary selenium, and availability of robust assays in human plasma, SelP has emerged as a major biomarker of selenium status. Here, we found that Cys is present in various Sec positions in human SelP. Treatment of cells expressing SelP with thiophosphate, an analog of the selenium donor for Sec synthesis, led to a nearly complete replacement of Sec with Cys, whereas supplementation of cells with selenium supported Sec insertion. SelP isolated directly from human plasma had up to 8% Cys inserted in place of Sec, depending on the Sec position. These findings suggest that a change in selenium status may be reflected in both SelP concentration and its Sec content, and that availability of the SelP-derived selenium for selenoprotein synthesis may be overestimated under conditions of low selenium status due to replacement of Sec with Cys. PMID:26452064

  19. Regulation of Selenocysteine Content of Human Selenoprotein P by Dietary Selenium and Insertion of Cysteine in Place of Selenocysteine.

    PubMed

    Turanov, Anton A; Everley, Robert A; Hybsier, Sandra; Renko, Kostja; Schomburg, Lutz; Gygi, Steven P; Hatfield, Dolph L; Gladyshev, Vadim N

    2015-01-01

    Selenoproteins are a unique group of proteins that contain selenium in the form of selenocysteine (Sec) co-translationally inserted in response to a UGA codon with the help of cis- and trans-acting factors. Mammalian selenoproteins contain single Sec residues, with the exception of selenoprotein P (SelP) that has 7-15 Sec residues depending on species. Assessing an individual's selenium status is important under various pathological conditions, which requires a reliable selenium biomarker. Due to a key role in organismal selenium homeostasis, high Sec content, regulation by dietary selenium, and availability of robust assays in human plasma, SelP has emerged as a major biomarker of selenium status. Here, we found that Cys is present in various Sec positions in human SelP. Treatment of cells expressing SelP with thiophosphate, an analog of the selenium donor for Sec synthesis, led to a nearly complete replacement of Sec with Cys, whereas supplementation of cells with selenium supported Sec insertion. SelP isolated directly from human plasma had up to 8% Cys inserted in place of Sec, depending on the Sec position. These findings suggest that a change in selenium status may be reflected in both SelP concentration and its Sec content, and that availability of the SelP-derived selenium for selenoprotein synthesis may be overestimated under conditions of low selenium status due to replacement of Sec with Cys. PMID:26452064

  20. 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.

    PubMed

    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) in body weight and feed intake and an increase (P < 0.05) in feed conversion ratio when broilers exposed to HS. In the overall period of the study (1 to 49 days), growth performance of TN broilers was not affected (P < 0.05) by vitamin E and selenium supplementation. However, under HS condition, broilers receiving 250 mg/kg vitamin E and 0.5 mg/kg selenium consumed more (P < 0.05) feed than that of broilers receiving 250 mg/kg vitamin E alone, but similar (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 < 0.05), but its selenium content was decreased (P < 0.05) by exposure to HS. The breast meat selenium content was increased (P < 0.05) by selenium supplementation. The breast meat selenium content was decreased (P < 0.05) by supplementation of 250 mg/kg vitamin E to diet of TN birds. However, the breast meat selenium content was increased (P < 0.05) by supplementation of vitamin E under HS condition. The breast meat MDA content was not affected (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

  1. Structural and Spectral Features of Selenium Nanospheres Produced by Se-Respiring Bacteria

    PubMed Central

    Oremland, Ronald S.; Herbel, Mitchell J.; Blum, Jodi Switzer; Langley, Sean; Beveridge, Terry J.; Ajayan, Pulickel M.; Sutto, Thomas; Ellis, Amanda V.; Curran, Seamus

    2004-01-01

    Certain anaerobic bacteria respire toxic selenium oxyanions and in doing so produce extracellular accumulations of elemental selenium [Se(0)]. We examined three physiologically and phylogenetically diverse species of selenate- and selenite-respiring bacteria, Sulfurospirillum barnesii, Bacillus selenitireducens, and Selenihalanaerobacter shriftii, for the occurrence of this phenomenon. When grown with selenium oxyanions as the electron acceptor, all of these organisms formed extracellular granules consisting of stable, uniform nanospheres (diameter, ∼300 nm) of Se(0) having monoclinic crystalline structures. Intracellular packets of Se(0) were also noted. The number of intracellular Se(0) packets could be reduced by first growing cells with nitrate as the electron acceptor and then adding selenite ions to washed suspensions of the nitrate-grown cells. This resulted in the formation of primarily extracellular Se nanospheres. After harvesting and cleansing of cellular debris, we observed large differences in the optical properties (UV-visible absorption and Raman spectra) of purified extracellular nanospheres produced in this manner by the three different bacterial species. The spectral properties in turn differed substantially from those of amorphous Se(0) formed by chemical oxidation of H2Se and of black, vitreous Se(0) formed chemically by reduction of selenite with ascorbate. The microbial synthesis of Se(0) nanospheres results in unique, complex, compacted nanostructural arrangements of Se atoms. These arrangements probably reflect a diversity of enzymes involved in the dissimilatory reduction that are subtly different in different microbes. Remarkably, these conditions cannot be achieved by current methods of chemical synthesis. PMID:14711625

  2. Structural and Spectral Features of Selenium Nanospheres Produced by Se-Respiring Bacteria

    USGS Publications Warehouse

    Oremland, R.S.; Herbel, M.J.; Blum, J.S.; Langley, S.; Beveridge, T.J.; Ajayan, P.M.; Sutto, T.; Ellis, A.V.; Curran, S.

    2004-01-01

    Certain anaerobic bacteria respire toxic selenium oxyanions and in doing so produce extracellular accumulations of elemental selenium [Se(0)]. We examined three physiologically and phylogenetically diverse species of selenate- and selenite-respiring bacteria, Sulfurospirillum barnesii, Bacillus selenitireducens, and Selenihalanaerobacter shriftii, for the occurrence of this phenomenon. When grown with selenium oxyanions as the electron acceptor, all of these organisms formed extracellular granules consisting of stable, uniform nanospheres (diameter, ???300 nm) of Se(0) having monoclinic crystalline structures. Intracellular packets of Se(0) were also noted. The number of intracellular Se(0) packets could be reduced by first growing cells with nitrate as the electron acceptor and then adding selenite ions to washed suspensions of the nitrate-grown cells. This resulted in the formation of primarily extracellular Se nanospheres. After harvesting and cleansing of cellular debris, we observed large differences in the optical properties (UV-visible absorption and Raman spectra) of purified extracellular nanospheres produced in this manner by the three different bacterial species. The spectral properties in turn differed substantially from those of amorphous Se(0) formed by chemical oxidation of H2Se and of black, vitreous Se(0) formed chemically by reduction of selenite with ascorbate. The microbial synthesis of Se(0) nanospheres results in unique, complex, compacted nanostructural arrangements of Se atoms. These arrangements probably reflect a diversity of enzymes involved in the dissimilatory reduction that are subtly different in different microbes. Remarkably, these conditions cannot be achieved by current methods of chemical synthesis.

  3. Long-term selenium biofortification in carrots and broccoli grown in soils amended with Se-enriched S. pinnata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops needed in Se-deficient ...

  4. Nutritional aspects of selenium

    SciTech Connect

    Choe, M.

    1987-01-01

    The overall objective of this project was to investigate the effect of protein and/or dietary fiber supplementation on selenium absorption and metabolism. These relationships might be of importance in determining either minimum selenium nutritional requirements or levels of intake at which this mineral becomes toxic. Three studies compose the project. The first study involved the controlled feeding of fifteen young adults mice. Subjects were fed a laboratory-controlled diet with and without supplements of selenium or selenium plus guar gum. Selenium supplementation resulted in increased selenium excretion in urine and feces. Supplementation of guar gum, as a dietary fiber, tended to increase fecal selenium excretion and to decrease selenium balance and glutathione peroxidase (GSH-Px) activity regardless of dietary selenium levels. In study II, seventy two weanling mice were fed varied levels of dietary selenium and protein. Numerically, urinary selenium excretion increased and fecal selenium excretion and selenium balance decreased with increased dietary protein level within the same level of dietary selenium; however, selenium absorption rate tended to decrease with increased dietary protein level. Whole blood and brain tissue glutathione peroxidase activities were higher in animals fed moderate protein level than those fed the other two protein levels. In study III, a survey was conducted to investigate the correlation between dietary fiber or protein intake and urinary selenium excretion. There was a negative correlation between dietary fiber and urinary selenium excretion levels while dietary protein and urinary selenium excretion were positively correlated.

  5. Selenium biofortification of broccoli and carrots grown in soil amended with Se-enriched hyperaccumulator Stanleya pinnata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amending soils with Se-hyperaccumulator plant derived sources of selenium (Se) may be useful for increasing Se content in food crops in Se-deficient regions of the world. In this study, we evaluated total Se and the different chemical species of Se in broccoli and carrots grown in soils amended with...

  6. Selenium and selenoprotein deficiencies induce widespread pyogranuloma formation in mice, while high levels of dietary selenium decrease liver tumor size driven by TGFa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 l...

  7. A dietary assessment of selenium risk to aquatic birds on a coal mine affected stream in Alberta, Canada

    SciTech Connect

    Wayland, M.; Casey, R.; Woodsworth, E.

    2007-07-15

    In this article, we present the results of a dietary-based assessment of the risk that selenium may pose to two aquatic bird species, the American Dipper (Cinclus mexicanus) and the Harlequin Duck (Histrionicus histrionicus), on one of the coal mine-affected streams, the Gregg River. The study consisted of (1) a literature-based toxicity assessment, (2) simulation of selenium exposure in the diets and eggs of the two species, and (3) a risk assessment that coupled information on toxicity and exposure. Diet and egg selenium concentrations associated with a 20% hatch failure rate were 6.4 and 17 {mu} g {center_dot} g{sup -1} dry wt, respectively. Simulated dietary selenium concentrations were about 2.0-2.5 {mu} g {center_dot} g{sup -1} higher on the Gregg River than on reference streams for both species. When simulated dietary concentrations were considered, hatch failure rates on the Gregg River were predicted to average 12% higher in American Dippers and 8% higher in Harlequin Ducks than at reference streams. Corresponding values were only 3% for both species when predicted egg concentrations were used. Elevated levels of selenium in insects in some of the reference streams were unexpected and raised a question as to whether aquatic birds have evolved a higher tolerance level for dietary selenium in these areas.

  8. Determination of selenium in dietary supplements by optical emission spectrometry after alkaline dissolution and subsequent headspace solid phase microextraction.

    PubMed

    Tyburska, Anna; Jankowski, Krzysztof

    2013-02-23

    Headspace solid phase microextraction (HSSPME) of chemically generated selenium hydride from alkaline solution followed by thermal desorption (TD) coupled directly to a microwave plasma (MWP) source has been examined for the optical emission spectrometric (OES) determination of Se. Various chemical and operating parameters including the NaBH(4) and HCl concentrations as well as the fiber exposure time and desorption temperature have been optimized. Alternatively, continuous hydride generation (HG) from alkaline medium and inductively coupled plasma (ICP) may be used for Se determination by OES. With the procedure developed, the determination of Se in dietary supplements at the tens of μgg(-1) level and an accuracy of 3-6% could be performed even in the presence of the 1000-fold excess of Fe and Cu. Additionally, Se was determined in the NIST 8418 material (Wheat gluten) with a certified concentration of Se of 2.58 ± 0.19 μgg(-1), and a value of 2.45 ± 0.25 μgg(-1) was found using HG-HSSPME-MWP-OES. The detection limit for Se (3.2 ng ml(-1)) with the proposed procedure was comparable to those obtained with HG-ICP-OES and the calibration curve was linear of about 2 orders of magnitude. PMID:23245260

  9. Fate of Selenium in Soils at a Seleniferous Site Recorded by High Precision Se Isotope Measurements.

    PubMed

    Schilling, Kathrin; Johnson, Thomas M; Dhillon, Karaj S; Mason, Paul R D

    2015-08-18

    Selenium poisoning is a significant health problem in parts of Punjab, India, which is an area of intense agricultural productivity. To determine the complex soil dynamics that control distribution of Se in this area, we measured concentrations and δ(82/76)Se of bulk Se and individual Se pools in four soil profiles. This was compared against δ(82/76)Se of crops and groundwater used for irrigation. The isotopic composition of bulk Se and component Se pools reveal spatial heterogeneity. The bulk δ(82/76)Se show progressively lower values with increasing soil depth indicating the preferential migration of isotopically lighter Se downward through the soil profile. The δ(82/76)Se of water-soluble Se is isotopically heavier than δ(82/76)Se of adsorbed Se, suggesting Se isotope fractionation by reduction prior to scavenging by reactive minerals in the soil. The organically bound Se is isotopically lighter than water-soluble Se and correlates with the C/N ratio at different soil depths. Thus, Se immobilization by redox cycling controls the biogeochemical Se cycle in the soil. Se isotope ratios help to trace biochemical processes of Se in agricultural seleniferous soils and provide an important assessment for better soil management mitigating Se concentrations of ecotoxicological levels. PMID:26177307

  10. Dietary selenium and prolonged exercise alter gene expression and activity of antioxidant enzymes in equine skeletal muscle.

    PubMed

    White, S H; Johnson, S E; Bobel, J M; Warren, L K

    2016-07-01

    Untrained Thoroughbred horses (6 mares and 6 geldings; 11 yr [SE 1] and 565 kg [SE 11]) were used to evaluate antioxidant gene expression and enzyme activity in blood and skeletal muscle in response to prolonged exercise after receiving 2 levels of dietary selenium for 36 d: 0.1 (CON; = 6) or 0.3 mg/kg DM (SEL; = 6). Horses were individually fed 1.6% BW coastal bermudagrass hay, 0.4% BW whole oats, and a mineral/vitamin premix containing no Se. Sodium selenite was added to achieve either 0.1 or 0.3 mg Se/kg DM in the total diet. On d 35, horses underwent 2 h of submaximal exercise in a free-stall exerciser. Blood samples were obtained before (d 0) and after 34 d of Se supplementation and on d 35 to 36 immediately after exercise and at 6 and 24 h after exercise. Biopsies of the middle gluteal muscle were obtained on d 0, before exercise on d 34, and at 6 and 24 h after exercise. Supplementation with Se above the NRC requirement (SEL) increased serum Se ( = 0.011) and muscle thioredoxin reductase (TrxR) activity ( = 0.051) but had no effect on glutathione peroxidase (GPx) activity in plasma, red blood cell (RBC) lysate, or muscle in horses at rest. Serum creatine kinase activity increased ( < 0.0001) in response to prolonged exercise but was not affected by dietary treatment. Serum lipid hydroperoxides were affected by treatment ( = 0.052) and were higher ( = 0.012) in horses receiving CON than SEL immediately following exercise. Muscle expression of was unchanged at 6 h but increased ( = 0.005) 2.8-fold 24 h after exercise, whereas muscle TrxR activity remained unchanged. Glutathione peroxidase activity increased in plasma (P < 0.0001) and decreased in RBC lysate ( = 0.010) after prolonged exercise. A Se treatment × time interaction was observed for RBC GPx activity (P = 0.048). Muscle and expression and GPx activity did not change during the 24-h period after exercise. Level of dietary Se had no overall effect on expression of , , , , , , or in muscle following

  11. Effects of dietary selenium exposure in captive American common eiders

    USGS Publications Warehouse

    Franson, J.C.; Hoffman, D.J.; Wells-Berlin, A. M.; Perry, M.C.; Bochsler, V.S.; Finley, D.L.; Flint, P.L.; Hollmen, T.

    2005-01-01

    We conducted two studies of Se exposure in captive common eiders (Somateria mollissima). In Study 1, eiders were fed diets with added Se (as L-selenomethionine) in concentrations increasing from 10 ppm to 80 ppm. In Study 2, eiders received control, low exposure (20 ppm Se), and high exposure (60 ppm Se) diets. One duck in the high exposure group in Study 2 died after 36 days. Remaining high exposure ducks in Study 2 and ducks in Study 1 were euthanized after losing 25-30% of their body weight, which occurred after 41 days and 60-78 days, respectively. Body weights did not differ between control and low exposure ducks in Study 2. At the end of Study 1, the mean Se concentration in blood was 32 ppm wet weight (ww). In Study 2, mean blood Se reached 14 ppm ww in the low exposure group and 17 ppm ww in high exposure ducks. Mean Se concentrations in liver were 1252 ppm dry weight (dw) in Study 1, and 351 and 735 ppm dw, respectively, in the low and high exposure groups of Study 2. Oxidative stress was evidenced by Se-associated effects on glutathione metabolism, but not entirely in the same manner as with previous laboratory studies in mallards. In plasma, activities of total and Se-dependent glutathione peroxidase increased with time. As Se concentrations in liver increased, Se-dependent glutathione peroxidase, glutathione reductase, oxidized glutathione, and the ratio of hepatic oxidized to reduced glutathione increased. Total and protein bound sulfhydryl concentrations, reduced glutathione, glutathione-S-transferase, and glucose-6-phosphate dehydrogenase in liver were negatively correlated with Se concentrations in the liver. In Study 2, spleen weights were significantly lower in ducks receiving 60 ppm Se than in those receiving 20 ppm. Gross lesions associated with high Se exposure included emaciation, absence of thymus, loss of nails from digits, and alopecia. Microscopic lesions included severe depletion of lymphoid organs, hepatopathy, and necrosis of feather

  12. Dietary nano-selenium relieves hypoxia stress and, improves immunity and disease resistance in the Chinese mitten crab (Eriocheir sinensis).

    PubMed

    Qin, Fenju; Shi, Miaomiao; Yuan, Hongxia; Yuan, Linxi; Lu, Wenhao; Zhang, Jie; Tong, Jian; Song, Xuehong

    2016-07-01

    Hypoxia is a relevant physiological challenge for crab culture, and the hemolymph plays a crucial role in response to the hypoxia. In a 60 d feeding trial, Chinese mitten crabs (Eriocheir sinensis) fed a diet containing 0.2 mg/kg nano-selenium (nanoSe) showed a significantly increased weight gain rate (WGR) and a reduced feed coefficient (FC) compared to those fed diets with 0, 0.1, 0.4, 0.8, and 1.6 mg/kg nanoSe. Another 90 d feeding trial was conducted to determine the influence of dietary nanoSe on the immune response in juvenile Chinese mitten crabs kept under the condition of hypoxia. The results showed that hypoxia stress resulted in significantly increased hemocyte counts (THC, LGC, SGC, and HC), expression levels of the hemocyanin gene and protein, lactic acid level, and antioxidant capacity (T-AOC activities, SOD activities, GSH-Px and GSH content) in hemolymph supernatant. When these crabs were infected with Aeromonas hydrophila bacteria, hypoxia exposure increased mortality, but it was alleviated by a diet supplemented with 0.2 mg/kg nanoSe. The up-regulative effects of nanoSe (0.2 mg/kg) on antioxidant capacity, hemocyte counts, and hemocyanin expression under hypoxia exposure were further strengthened throughout, whereas lactic acid levels induced by hypoxia stress were restored. Thus, the observations in this study indicate that the level of dietary nanoSe is important in regulating immunity and disease resistance in crabs kept under hypoxia stress. PMID:27153751

  13. Chromatographic separation of selenium and arsenic: A potential (72)Se/(72)As generator.

    PubMed

    Wycoff, Donald E; Gott, Matthew D; DeGraffenreid, Anthony J; Morrow, Ryan P; Sisay, Nebiat; Embree, Mary F; Ballard, Beau; Fassbender, Michael E; Cutler, Cathy S; Ketring, Alan R; Jurisson, Silvia S

    2014-05-01

    An anion exchange method was developed to separate selenium and arsenic for potential utility in a (72)Se/(72)As generator. The separation of the daughter (72)As from the (72)Se parent is based on the relative acid-base behavior of the two oxo-anions in their highest oxidation states. At pH 1.5, selenate is retained on strongly basic anion exchange resin as HSeO4(-) and SeO4(2-), while neutral arsenic acid, H3AsO4, is eluted. PMID:24679827

  14. Chromatographic Separation of Selenium and Arsenic: A Potential 72Se/72As Generator

    PubMed Central

    Wycoff, Donald E.; Gott, Matthew D.; DeGraffenreid, Anthony J.; Morrow, Ryan P.; Sisay, Nebiat; Embree, Mary F.; Ballard, Beau; Fassbender, Michael E.; Cutler, Cathy S.; Ketring, Alan R.; Jurisson, Silvia S.

    2014-01-01

    Summary An anion exchange method was developed to separate selenium and arsenic for potential utility in a 72Se/72As generator. The separation of the daughter 72As from the 72Se parent is based on the relative acid-base behavior of the two oxo-anions in their highest oxidation states. At pH 1.5, selenate is retained on strongly basic anion exchange resin as HSeO4− and SeO42−, while neutral arsenic acid, H3AsO4, is eluted. PMID:24679827

  15. Sodium selenite/selenium nanoparticles (SeNPs) protect cardiomyoblasts and zebrafish embryos against ethanol induced oxidative stress.

    PubMed

    Kalishwaralal, Kalimuthu; Jeyabharathi, Subhaschandrabose; Sundar, Krishnan; Muthukumaran, Azhaguchamy

    2015-10-01

    Alcoholic cardiomyopathy is the damage caused to the heart muscles due to high level of alcohol consumption resulting in enlargement and inflammation of the heart. Selenium is an important trace element that is beneficial to human health. Selenium protects the cells by preventing the formation of free radicals in the body. In the present study, protein mediated synthesis of SeNPs was investigated. Two different sizes of SeNPs were synthesized using BSA and keratin. The synthesized SeNPs were characterized by scanning electron microscopy (SEM) with elemental composition analysis Energy Dispersive X-ray spectroscopy(EDX) and X-ray diffraction (XRD). This study demonstrates the in vitro and in vivo antioxidative effects of sodium selenite and SeNPs. Further selenium and SeNPs were evaluated for their ability to protect against 1% ethanol induced oxidative stress in H9C2 cell line. The selenium and SeNPs were found to reduce the 1% ethanol-induced oxidative damage through scavenging intracellular reactive oxygen species. The selenium and SeNPs could also prevent pericardial edema induced ethanol treatment and reduced apoptosis and cell death in zebrafish embryos. The results indicate that selenium and SeNPs could potentially be used as an additive in alcoholic beverage industry to control the cardiomyopathy. PMID:26302921

  16. Selenium Treatment Technologies

    EPA Science Inventory

    Selenium (Se) is a metalloid that is a dietary requirement in small quantities, but toxic at higher quantities. It also is known to bioaccumulate. In oxic environments, it exists as selenate (+6) and selenite (+4), both of which are soluble. Selenite will sorb more strongly to...

  17. Selenium speciation in Lower Cambrian Se-enriched strata in South China and its geological implications

    NASA Astrophysics Data System (ADS)

    Fan, Haifeng; Wen, Hanjie; Hu, Ruizhong; Zhao, Hui

    2011-12-01

    To understand the impact of Selenium (Se) into the biogeochemical cycle and implications for palaeo-redox environment, a sequential extraction method was utilized for samples including black shales, cherts, a Ni-Mo-Se sulfide layer, K-bentonite and phosphorite from Lower Cambrian Se-enriched strata in southern China. Seven species (water-soluble, phosphate exchangeable, base-soluble, acetic acid-soluble, sulfide/selenide associated, residual Se) and different oxidation states (selenate Se(VI), selenite Se(IV), organic Se, Se (0) and mineral Se(-II)) were determinated in this study. We found that the Ni-Mo-Se sulfide layer contained a significantly greater amount of Se(-II) associated with sulfides/selenides than those in host black shales and cherts. Furthermore, a positive correlation between the degree of sulfidation of iron (DOS) and the percentage of the sulfide/selenide-associated Se(-II) was observed for samples, which suggests the proportion of sulfide/selenide-associated Se(-II) could serve as a proxy for palaeo-redox conditions. In addition, the higher percentage of Se(IV) in K-bentonite and phosphorite was found and possibly attributed to the adsorption of Se by clay minerals, iron hydroxide surfaces and organic particles. Based on the negative correlations between the percentage of Se(IV) and that of Se(-II) in samples, we propose that the K-bentonite has been altered under the acid oxic conditions, and the most of black shale (and cherts) and the Ni-Mo-Se sulfide layer formed under the anoxic and euxinic environments, respectively. Concerning Se accumulation in the Ni-Mo-Se sulfide layer, the major mechanism can be described by (1) biotic and abiotic adsorption and further dissimilatory reduction from oxidized Se(VI) and Se(IV) to Se(-II), through elemental Se, (2) contribution of hydrothermal fluid with mineral Se(-II).

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

    PubMed

    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

  19. Toxicity and oxidative stress of different forms of organic selenium and dietary protein in mallard ducklings

    USGS Publications Warehouse

    Hoffman, D.J.; Heinz, G.H.; LeCaptain, L.J.; Eisemann, J.D.; Pendleton, G.W.

    1996-01-01

    Concentrations of over 100 ppm (mg/kg) selenium (Se) have been found in aquatic plants and insects associated with irrigation drainwater and toxicity to fish and wildlife. Composition of diet for wild ducklings may vary in selenium-contaminated environments. Earlier studies have compared toxicities and oxidative stress of Se as selenite to those of seleno-DL-methionine (DL) in mallards (Anas platyrhynchos). This study compares DL, seleno-L-methionine (L), selenized yeast (Y) and selenized wheat (W). Day-old mallard ducklings received an untreated diet (controls) containing 75% wheat (22% protein) or the same diet containing 15 or 30 ppm Se in the above forms except for 30 ppm Se as W. After 2 weeks blood and liver samples were collected for biochemical assays and Se analysis. All forms of selenium caused significant increases in plasma and hepatic glutathione peroxidase activities. Se as L at 30 ppm in the diet was the most toxic form, resulting in high mortality (64%) and impaired growth (>50%) in survivors and the greatest increase in ratio of oxidized to reduced hepatic glutathione (GSH). Se as both L and DL decreased the concentrations of hepatic GSH and total thiols. Se as Y accumulated the least in liver (approximately 50% of other forms) and had less effect on GSH and total thiols. In a second experiment, in which the basal diet was a commercial duck feed (22 % protein), survival was not affected by 30 ppm Se as DL, L, or Y and oxidative effects on GSH metabolism were less pronounced than with the wheat diet.

  20. A low level of dietary selenium has both beneficial and toxic effects and is protective against Cd-toxicity in the least killifish Heterandria formosa.

    PubMed

    Xie, Lingtian; Wu, Xing; Chen, Hongxing; Dong, Wu; Cazan, Alfy Morales; Klerks, Paul L

    2016-10-01

    As an essential element, selenium (Se) is beneficial at low levels yet toxic at high levels. The present study assessed the effects of dietary exposure to Se in the least killifish Heterandria formosa, and investigated how this exposure influences the effects of a subsequent exposure to cadmium (Cd). The fish were pre-exposed to an environmentally relevant concentration (2 μg g(-1) dry wt) of dietary selenite (Se(4+)) or seleno-l-methionine (Se-Met) for 10 d. The same fish were then exposed to 0.5 mg L(-1) of Cd for 5 d. Both Se(IV) and Se-Met rapidly accumulated in H. formosa. Results for the two Se species were generally similar in this study. Fish exposed to Se had lower levels of lipid peroxidation (measured as levels of thiobarbituric acid reactive substances or TBARS) and a higher catalase (CAT) activity. In contrast, their Na(+)/K(+)-ATPase activity was reduced. The Cd exposure resulted in an increase in lipid peroxidation and decreases in the activities of catalase and Na(+)/K(+)-ATPase. The Cd-exposed H. formosa that were pre-exposed to Se had lower Cd body burdens, less lipid peroxidation, and higher catalase activity, than did fish not pre-exposed to Se. The Se exposure did not have a protective effect on the Cd-induced reduction in Na(+)/K(+)-ATPase activity. These results clearly demonstrate that a Se-enriched diet reduces some (but not all) forms of Cd-toxicity and that Se can simultaneously have beneficial and detrimental effects, making it difficult to predict the net outcome of changes in dietary Se levels for fish. PMID:27448316

  1. Biosynthesis of selenium rich exopolysaccharide (Se-EPS) by Pseudomonas PT-8 and characterization of its antioxidant activities.

    PubMed

    Ye, Shuhong; Zhang, Jiajia; Liu, Zhaofang; Zhang, Yu; Li, Jiang; Li, Yao Olive

    2016-05-20

    Biosynthesis of organo-selenium is achieved by submerged fermentation of selenium-tolerant Pseudomonas PT-8. The end product of metabolic process is selenium-bearing exopolysaccharide (Se-EPS), which contains a higher content of uronic acid than the exopolysaccharide (EPS) by the strain without selenium in the culture medium. Selenium content in Se-EPS reached a maximum yield of 256.7 mg/kg when using an optimized culture condition. Crude Se-EPS was purified into two fractions-a pH neutral Se-EPS-1 and an acidic Se-EPS-2. Structure and chemical composition of Se-EPS-2 were investigated by chromatographic analyses. Results showed that Se-EPS-2 was a homogenous polysaccharide with molecular weight of 7.3 kDa, consisting of monosaccharides, rhamnose, arabinose, xylose, mannose, glucose and galactose with a molar ratio of 19.58:19.28:5.97:18.99:23.70:12.48, respectively. Compared to the EPS, the content of rhamnose in Se-EPS increased and molecular weight decreased. The Se-EPS had strong scavenging actions on DPPH•, •OH and •O2(-), which is much higher than the EPS. PMID:26917395

  2. Effects of Dietary Selenium Supplementation on Seminiferous Tubules and SelW, GPx4, LHCGR, and ACE Expression in Chicken Testis.

    PubMed

    Khalid, Ahmed; Khudhair, Nagam; He, Huang; Peng, Zheng; Yaguang, Tian; Guixue, Zhang

    2016-09-01

    We investigated the effects of dietary selenium (Se) supplementation on the development of chicken testis and the expression of selenoprotein W (SelW), glutathione peroxidase4 (GPx4), luteinizing hormone/choriogonadotropin receptor (LHCGR), and angiotensin converting enzyme (ACE). Sixty roosters were assigned randomly into the control group fed with a basic diet (containing 0.3 mg Se/kg) and the experimental group fed with a diet (containing 0.6 mg Se/kg). The testes were collected individually at age of 6, 9, and 12 weeks. Se was supplemented in chicken feed for 15 days before sampling. The results indicated that dietary Se affected the number of cells in the seminiferous tubules and viability of Sertoli cells in vitro culture. SelW and GPx4 expression in the testes increased significantly in the experimental group compared to that in the control group. LHCGR expression in the testes increased significantly in the experimental group after 12 weeks compared to that in the control group. In contrast, ACE expression was inhibited in the experimental group compared to that in the control group. These results suggest that dietary supplementation with Se improved development of the seminiferous tubules at the cellular level and that SelW, GPx4, LHCGR, and ACE are involved. PMID:26899318

  3. Dietary products consumption in relation to serum 25-hydroxyvitamin D and selenium level in Saudi children and adults

    PubMed Central

    Al-Daghri, Nasser M; Al-Attas, Omar; Yakout, Sobhy; Aljohani, Naji; Al-Fawaz, Hanan; Alokail, Majed S

    2015-01-01

    Vitamin D deficiency is a global health threat that has been associated with several chronic diseases. Selenium is an essential trace element because of role in major metabolic processes, immune function, thyroid hormone metabolism, male infertility, neoplasms and cardiovascular disease. We aimed to investigate for the first time in the Saudi population the association between vitamin D and selenium status with various dietary products consumption. A total of 259 children and 95 adults were included in this cross-sectional study. We estimated the consumption frequencies of various dietary food products using a qualitative food frequency questionnaire (FFQ) and also measured serum levels of 25-hydroxyvitamin D and selenium. Associations between variables of interest were assessed. Vitamin D deficiency and insufficiency were observed in 80% of the boys, 90% of the girls, 64% of men and 50% of women. Modest associations were found between mean serum 25 (OH) D concentration and consumption frequencies of fresh milk in children (r=0.11; P<0.05), more specifically in girls (r=0.12; P<0.05), and to the overall consumption of dairy products in women (r=0.12; P<0.05). Vitamin D status was also inversely associated with selenium in adults (r=-0.43; P<0.05). There was a significant correlation between delta changes of serum selenium, triglycerides and HDL levels (P-values <0.05). Vitamin D and selenium levels are modestly associated with dietary products consumption. Changes in selenium levels were associated with increased serum triglyceride levels, indicating a potential biomarker for cardiovascular risk and dyslipidemia. The widespread vitamin D deficiency observed in the present study highlight the need for adequate fortification of dairy products. PMID:25785131

  4. Dietary products consumption in relation to serum 25-hydroxyvitamin D and selenium level in Saudi children and adults.

    PubMed

    Al-Daghri, Nasser M; Al-Attas, Omar; Yakout, Sobhy; Aljohani, Naji; Al-Fawaz, Hanan; Alokail, Majed S

    2015-01-01

    Vitamin D deficiency is a global health threat that has been associated with several chronic diseases. Selenium is an essential trace element because of role in major metabolic processes, immune function, thyroid hormone metabolism, male infertility, neoplasms and cardiovascular disease. We aimed to investigate for the first time in the Saudi population the association between vitamin D and selenium status with various dietary products consumption. A total of 259 children and 95 adults were included in this cross-sectional study. We estimated the consumption frequencies of various dietary food products using a qualitative food frequency questionnaire (FFQ) and also measured serum levels of 25-hydroxyvitamin D and selenium. Associations between variables of interest were assessed. Vitamin D deficiency and insufficiency were observed in 80% of the boys, 90% of the girls, 64% of men and 50% of women. Modest associations were found between mean serum 25 (OH) D concentration and consumption frequencies of fresh milk in children (r=0.11; P<0.05), more specifically in girls (r=0.12; P<0.05), and to the overall consumption of dairy products in women (r=0.12; P<0.05). Vitamin D status was also inversely associated with selenium in adults (r=-0.43; P<0.05). There was a significant correlation between delta changes of serum selenium, triglycerides and HDL levels (P-values <0.05). Vitamin D and selenium levels are modestly associated with dietary products consumption. Changes in selenium levels were associated with increased serum triglyceride levels, indicating a potential biomarker for cardiovascular risk and dyslipidemia. The widespread vitamin D deficiency observed in the present study highlight the need for adequate fortification of dairy products. PMID:25785131

  5. Environmental Selenium Transformations: Distinguishing Abiotic and Biotic Factors Influencing Se Redox Transformations

    NASA Astrophysics Data System (ADS)

    Rosenfeld, C.; Kenyon, J.; James, B. R.; Santelli, C. M.

    2014-12-01

    Worldwide, selenium (Se) is proving to be a significant environmental concern, with many anthropogenic activities (e.g. coal mining and combustion, phosphate mining and agricultural irrigation) releasing potentially hazardous concentrations into surface and subsurface ecosystems. The US EPA is currently considering aquatic Se regulations, however no guidelines exist for excess soil Se, despite its ability to act as a persistent Se source. Various abiotic and biological processes mediate Se oxidation/reduction (redox) transformations in soils, thus influencing its solubility and bioavailability. In this research we assess (1) the ability of metal-transforming fungal species to aerobically reduce Se (Se (IV and/or VI) to Se(0)), and (2) the relative contribution of biotic and abiotic pathways for aerobic Se transformation. The primary objective of this research is to determine what abiotic and biotic factors enhance or restrict Se bioavailability. Results indicate that fungal-mediated Se reduction may be quite widespread, with at least 7 out of 10 species of known Mn(II)-oxidizing fungi isolated from metal impacted environments also identified as capable of aerobically reducing Se(IV) and/or Se(VI) to Se(0). Increasing concentrations of selenite (SeO32-; Se(IV)) and selenate (SeO42-; Se(VI)) generally reduced fungal growth rates, although selenate was more likely to inhibit fungal growth than selenite. To study oxidation, Se(0) was combined with Mn(III/IV) (hydr)oxides (henceforth referred to as Mn oxides), Se-transforming fungi (Alternaria alternata), and oxalic acid to mimic Se biogeochemistry at the plant-soil interface. Increased pH in the presence of fungi (7.2 with fungi, 6.8 without fungi after 24 days) was observed. Additionally, a slight decrease in redox potential was measured for incubations without Mn oxides (236 mV with Mn oxides, 205 mV without Mn oxides after 24 days), indicating that Mn oxides may enhance Se oxidation. Elemental Se oxidation rates to

  6. Estimation of selenium (Se) intake from Se in serum, whole blood, toenails, or urine

    SciTech Connect

    Longnecker, M.P.; Taylor, P.R.; Levander, O.A.; Flack, V.; Veillon, C.; McAdam, P.A.; Patterson, K.Y.; Holden, J.; Stampfer, M.J.; Morris, J.S.; Willett, W.C. NCI, Rockville, MD USDA, Beltsville, MD Harvard Univ., Boston, MA Univ. of Missouri, Columbia )

    1991-03-11

    Because Se content of food varies widely, estimates of intake based on Se status are more accurate than those based on food composition tables. 77 free-living subjects from South Dakota and Wyoming, where the range of Se intake was large, provided blood, toenails, and 24-hour urines. Se intake, measured by chemical analysis of 4-8 days of duplicate-plate food composites from each subject, was estimated on the basis of the Se indices. To predict the natural logarithm of Se intake from serum Se the best fit was provided by : {minus}0.465 + 0.568{asterisk}SSe. Addition of lean body mass (LBM (kg)) and energy intake (EI (MJ)) to the model markedly improved the fit. Models based on Se in blood or urine gave slightly better estimates than those based on toenail Se. Consideration of data in addition to indices of Se status resulted in improved estimates of intake.

  7. THE EFFECTS OF DIETARY VITAMIN E AND SELENIUM DEFICIENCIES ON PLASMA THYROID AND THYMIC HORMONE CONCENTRATIONS IN THE CHICKEN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beginning at hatching, male Cornell K strain single comb white leghorn chickens were fed a basal diet, with or without vitamin E (100 IU/kg) and/or selenium (Se, 0.2 ppm). After 3 weeks of treatment, animals fed either the Se-deficient or basal diet had significantly reduced plasma Se-dependent glut...

  8. Selenium-mercury interaction during intestinal absorption of /sup 75/Se compounds in chicks

    SciTech Connect

    Mykkaenen, H.M.M.; Metsaeniitty, L.

    1987-08-01

    The effects of inorganic (HgCl/sub 2/) and organic (CH/sub 3/HgCl) mercury on the intestinal absorption of Se compounds (Na/sub 2/(75)SeO/sub 3/, Na/sub 2/(75)SeO4, L-(/sup 75/Se)methionine ((/sup 75/Se)Met)) were determined in 3-wk-old White Leghorn cockerels by the in vivo ligated duodenal loop procedure. The intraduodenal dose contained 0.05 microCi /sup 75/Se, 0.01 mM Se, 150 mM NaCl and 0-1.0 mM Hg. In the presence of 1 mM inorganic Hg in the intraduodenal dose, the absorption of the inorganic /sup 75/Se compounds was only about 65% of that in the control group, whereas only a slight inhibitory effect on (/sup 75/Se)Met absorption was observed. Methylmercury had no effect on (/sup 75/Se)selenite absorption. Precipitation of the /sup 75/Se-selenite in the intestinal lumen partly explained the direct interaction between inorganic Hg and Se compounds. Absorption of (/sup 75/Se)Met and (/sup 75/Se)selenite was also determined in chicks fed after hatching a purified diet supplemented with varying amounts of Hg (0-500 mg/kg) and Se (0-4 mg/kg). Dietary Hg significantly reduced the transfer of (/sup 75/Se)selenite to body by enhancing the accumulation of the isotope in the intestinal tissue. Dietary Hg did not affect the absorption of (/sup 75/Se)Met, but altered the whole-body distribution of this Se compound. Because interaction between Se and Hg was observed mainly between the inorganic compounds and with use of a manyfold excess of Hg over Se, the data suggest that intestinal interaction between these metals is not of great nutritional importance.

  9. Decreased survival and teratogenesis during laboratory selenium exposures to bluegill, Lepomis macrochirus

    SciTech Connect

    Woock, S.E.; Garrett, W.R.; Partin, W.E.; Bryson, W.T.

    1987-12-01

    Bluegill (Lepomis macrochirus) embryo-larval studies using eggs of feral fish from a selenium-contaminated reservoir found low larval survival and teratogenesis when ovarian selenium concentrations were high. Since dietary sources supply most of the selenium that accumulates in fish, the authors hypothesized that reproductive impairment could occur if the dietary concentrations were sufficiently elevated and the chemical form of selenium was equivalent to the form experienced by the fish in the environment. This hypothesis was studied in a partial life cycle test by comparing the effects of chronic dietary exposure of selenomethionine (SeMet) and selenite (Se4+) to bluegill sunfish. They also tested one combination of dietary SeMet and waterborne Se4+. SeMet was selected as the organic form because in a preliminary study its accumulation was most similar to that of naturally occurring selenium in bluegill. Se4+ was selected as the inorganic form because it is the predominant oxidation state in some contaminated cooling reservoirs. The authors demonstrate that for larval bluegill (1) elevated dietary selenium exposure to parent fish causes teratogenesis and decreases larval survival, (2) parental dietary organoselenium is more toxic than dietary inorganic selenium, and (3) the combination of parental dietary, plus waterborne exposure, is more toxic than dietary exposure alone.

  10. Selenium Chain Length Distribution in GexSe100-x Glasses: Insights from (77)Se NMR Spectroscopy and Quantum Chemical Calculations.

    PubMed

    Kaseman, Derrick C; Oliveira, Karina Moreira; Palazzo, Teresa; Sen, Sabyasachi

    2016-05-19

    The statistics of selenium chain length distribution in GexSe100-x glasses with 5 ≤ x ≤ 20 are investigated using a combination of high-resolution, two-dimensional (77)Se nuclear magnetic resonance (NMR) spectroscopy and quantum chemical calculations. This combined approach allows for the distinction of various selenium chain environments on the basis of subtle but systematic effects of next-nearest neighbors of Se atoms in -Se-Se-Se- linkages on the (77)Se chemical shift tensor parameters. Simulation of the experimental (77)Se NMR spectral line shapes indicates that Se chain speciation in these chalcogenide glasses follows the Flory-Schulz distribution, originally developed for organic chain polymers. PMID:27129100

  11. Effect of dietary fat on plasma glutathione peroxidase levels and intestinal absorption of /sup 75/Se-labeled sodium selenite in chicks

    SciTech Connect

    Mutanen, M.L.; Mykkaenen, H.M.

    1984-05-01

    The effect of dietary fat on the availability of selenium was investigated in chicks fed either 4 or 20% butter, olive oil, rape oil, corn oil or sunflower oil in the diet for 3 weeks after hatching. Plasma glutathione peroxidase (GSH-Px) activity was used as an indicator of the body selenium status. In addition, the intestinal absorption of sodium selenite (/sup 75/Se-labeled) was determined by using both the in vivo ligated loop procedure and oral administration of the isotope. The plasma GSH-Px levels increased with increasing proportion of the polyunsaturated fatty acids in the diet. Increasing the amount of fat from 4 to 20% significantly enhanced the GSH-Px activity in the groups receiving butter or olive oil, but had no effect in animals fed the unsaturated fats. The absorption of (/sup 75/Se)selenite from the ligated duodenal loops tended to be reduced in chicks fed corn oil or sunflower oil as compared to the animals receiving butter in their diet. On the other hand, the type of dietary fat did not appear to affect the absorption of the orally administered selenite. The present study demonstrates that the type of dietary fat can affect the plasma GSH-Px levels in chicks without altering the intestinal absorption of selenite. However, the results on the absorption of the intraduodenally injected sodium selenite suggest that dietary fat plays some role in the intestinal transport of selenium.

  12. Selenium Redox Reactivity on Colloidal CdSe Quantum Dot Surfaces

    PubMed Central

    2016-01-01

    Understanding the structural and compositional origins of midgap states in semiconductor nanocrystals is a longstanding challenge in nanoscience. Here, we report a broad variety of reagents useful for photochemical reduction of colloidal CdSe quantum dots, and we establish that these reactions proceed via a dark surface prereduction step prior to photoexcitation. Mechanistic studies relying on the specific properties of various reductants lead to the proposal that this surface prereduction occurs at oxidized surface selenium sites. These results demonstrate the use of small-molecule inorganic chemistries to control the physical properties of colloidal QDs and provide microscopic insights into the identities and reactivities of their localized surface species. PMID:27518320

  13. Selenium Redox Reactivity on Colloidal CdSe Quantum Dot Surfaces.

    PubMed

    Tsui, Emily Y; Hartstein, Kimberly H; Gamelin, Daniel R

    2016-09-01

    Understanding the structural and compositional origins of midgap states in semiconductor nanocrystals is a longstanding challenge in nanoscience. Here, we report a broad variety of reagents useful for photochemical reduction of colloidal CdSe quantum dots, and we establish that these reactions proceed via a dark surface prereduction step prior to photoexcitation. Mechanistic studies relying on the specific properties of various reductants lead to the proposal that this surface prereduction occurs at oxidized surface selenium sites. These results demonstrate the use of small-molecule inorganic chemistries to control the physical properties of colloidal QDs and provide microscopic insights into the identities and reactivities of their localized surface species. PMID:27518320

  14. Effects of Dietary Selenium Against Lead Toxicity Are Related to the Ion Profile in Chicken Muscle.

    PubMed

    Jin, Xi; Liu, Chun Peng; Teng, Xiao Hua; Fu, Jing

    2016-08-01

    Complex antagonistic interactions between Selenium (Se) and heavy metals have been reported in previous studies. However, little is known regarding the effects of Se on lead (Pb)-induced toxicity and the ion profile in the muscles of chickens. In this present study, we fed chickens either Se or Pb or both Se and Pb supplement and later analyzed the concentrations of 26 ions in chicken muscle tissues. We determined that a Se- and Pb-containing diets significantly affected microelements in chicken muscle. Treatment with Se increased the content of Se but resulted in a reduced concentration of Cu, As, Cd, Sn, Hg, and Ba. Treatment with Pb increased concentrations of Ni while reducing those of B, V, Cr, Fe, Co, Cu, Zn, and Mo. Moreover, Se also reduced the concentration of Pb, Zn, Co, Fe, V, and Cr, which in contrast were induced by Pb. Additionally, we also found that synergistic and antagonistic interactions existed between Se and Pb supplementation. Our findings suggested that Se can exert a negative effect on Pb in chicken muscle tissues and may be related to changes in ion profiles. PMID:26743866

  15. The electrical characterizations of selenium (Se) doped gallium antimony (GaSb) single crystal

    NASA Astrophysics Data System (ADS)

    Choudhari, Rashmi; Deshpande, Manisha; Maske, Dilip; Gadkari, Dattatray

    2016-05-01

    The growth of Se doped GaSb bulk crystal is carried out using Vertical directional solidification (VDS) technique. High purity Gallium and Antimony is taken as source material and selenium as doping material. From grown ingot substrate were obtained in wafer form using diamond cutter. The electrical characteristics such as Hall measurement is used to find the carrier concentration and mobility, while Van der pauw for measuring resistivity of the sample The GaSb:Se sample shows high resistivity and mobility. The grown crystal was detached from the ampoule wall with high crystal quality. The measured resistivity of GaSb:Se is 9.9×10-3ohm-cm, the mobility is 1464cm3/Vsec and carrier concentration is 5.08×1017 per cm3.

  16. Selenium toxicity from a misformulated dietary supplement, adverse health effects, and the temporal response in the nail biologic monitor.

    PubMed

    Morris, John Steven; Crane, Stacy B

    2013-04-01

    Use of dietary supplements in the U.S. has increased steadily over the last 25 years. While misformulation is uncommon, the consequences can be serious. A March 2008 voluntary market recall removed supplement products responsible for the most serious selenium toxicity outbreak that has occurred in the U.S. We quantified selenium concentrations in the misformulated supplement products, measured the temporal response in the nail biologic monitor, and associated exposure to self-reported selenosis symptoms. Subjects recruited through state health departments and referrals provided samples of the misformulated supplement products, exposure information, monthly toenail and or fingernail clippings or onycholysitic nail fragments, and listed their newly onset adverse health effects attributed to selenium toxicity. Ninety-seven subjects enrolled and submitted at least one test sample. Peak selenium concentrations (up to 18.3 and 44.1 μg/g for toenails and fingernails, respectively) were measured. Multiple samples (52 total) of all six recalled supplement lots were analyzed ranging from 22,300 to 32,200 μg selenium per daily dose. Average consumption was 30.9 ± 13.9 doses; 73 subjects provided follow-up data on selenosis symptoms at 2.50 ± 0.14 years. Nail samples accurately reflect exposure in this selenium toxicity outbreak, which resulted in long-term/permanent adverse health effects. PMID:23538937

  17. Selenium Toxicity from a Misformulated Dietary Supplement, Adverse Health Effects, and the Temporal Response in the Nail Biologic Monitor

    PubMed Central

    Morris, John Steven; Crane, Stacy B.

    2013-01-01

    Use of dietary supplements in the U.S. has increased steadily over the last 25 years. While misformulation is uncommon, the consequences can be serious. A March 2008 voluntary market recall removed supplement products responsible for the most serious selenium toxicity outbreak that has occurred in the U.S. We quantified selenium concentrations in the misformulated supplement products, measured the temporal response in the nail biologic monitor, and associated exposure to self-reported selenosis symptoms. Subjects recruited through state health departments and referrals provided samples of the misformulated supplement products, exposure information, monthly toenail and or fingernail clippings or onycholysitic nail fragments, and listed their newly onset adverse health effects attributed to selenium toxicity. Ninety-seven subjects enrolled and submitted at least one test sample. Peak selenium concentrations (up to 18.3 and 44.1 μg/g for toenails and fingernails, respectively) were measured. Multiple samples (52 total) of all six recalled supplement lots were analyzed ranging from 22,300 to 32,200 μg selenium per daily dose. Average consumption was 30.9 ± 13.9 doses; 73 subjects provided follow-up data on selenosis symptoms at 2.50 ± 0.14 years. Nail samples accurately reflect exposure in this selenium toxicity outbreak, which resulted in long-term/permanent adverse health effects. PMID:23538937

  18. Effect of dietary selenium and vitamin E on ganders' response to semen collection and ejaculate characteristics.

    PubMed

    Jerysz, Anna; Lukaszewicz, Ewa

    2013-06-01

    Compared to other domestic bird species, geese exhibit the lowest reproductive efficiency (poor semen quality, low egg production, and poor fertility and hatchability rates). From an economic perspective, it is a necessity of improve these reproductive traits. Studies have demonstrated that the essential trace element-selenium-plays key roles in testicular development and the maintenance of spermatogenesis. The aim of the present study was to determine the effect of feed supplementation with organic selenium and vitamin E on ganders' response to manual semen collection and semen quality. Sixteen 3-year-old White Koluda ganders were randomly divided into two groups. The control group was provided commercial feed while the experimental group was provided with the same commercial feed supplemented with selenium (0.3 mg/kg) and vitamin E (100 mg/kg). The response of individual ganders from both groups to manual semen collection and the quality of the semen collected were evaluated. The supplements increased (P ≤ 0.05) the frequency and decreased the time interval of a complete ejaculatory response of the ganders to manual semen collections (82.7 % supplement vs. 73.5 % control). Males from the supplemented group had significantly higher (P ≤ 0.01; P ≤ 0.05) ejaculate volumes, sperm concentrations, and percentages of viable sperm and lower percentages of immature sperm (spermatids). Lipids peroxidation, expressed in terms of the malondialdehyde concentration, was lower (P ≤ 0.01) in semen of the supplemented group (0.172 nmol/50 × 10(6)) as compared to the controls (0.320 nmol/50 × 10(6)). Moreover, the duration of the reproductive period of the ganders in the experimental group was 1 week longer. The results show that supplemental dietary selenium and vitamin E improved both the ganders' response to manual semen collection and semen quality. We conclude that such feed supplementation could lead to greater economic benefits

  19. Removal of selenium from water with nanoscale zero-valent iron: mechanisms of intraparticle reduction of Se(IV).

    PubMed

    Ling, Lan; Pan, Bingcai; Zhang, Wei-xian

    2015-03-15

    Increasing evidences suggest that nanoscale zero-valent iron (nZVI) is an effective agent for treatment and removal of selenium from water. For example, 1.3 mM selenite was quickly removed from water within 3 min with 5 g/L nZVI. In this work, reaction mechanisms of selenite [Se(IV)] in a single core-shell structured nanoscale zero-valent iron (nZVI) particle were studied with the method of spherical aberration corrected scanning transmission electron microscopy (Cs-STEM) integrated with X-ray energy dispersive spectroscopy (XEDS). This method was utilized to visualize solid phase translocation and transformation of Se(IV) such as diffusion, reduction, deposition and the effect of surface defects in a single nanoparticle. Se(IV) was reduced to Se(-II) and Se(0), which then formed a 0.5 nm layer of selenium at the iron oxide-Fe(0) interface at a depth of 6 nm from the surface. The results provided near atomic-resolution proof on the intraparticle diffusion-reduction of Se(IV) induced by nZVI. The STEM mapping also discovered that defects on the surface layer accelerate the diffusion of selenium and increase the capacity of nZVI for selenium sequestration. PMID:25622004

  20. Analytical determination of selenium in medical samples, staple food and dietary supplements by means of total reflection X-ray fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Stosnach, Hagen

    2010-09-01

    Selenium is essential for many aspects of human health and, thus, the object of intensive medical research. This demands the use of analytical techniques capable of analysing selenium at low concentrations with high accuracy in widespread matrices and sometimes smallest sample amounts. In connection with the increasing importance of selenium, there is a need for rapid and simple on-site (or near-to-site) selenium analysis in food basics like wheat at processing and production sites, as well as for the analysis of this element in dietary supplements. Common analytical techniques like electrothermal atomic absorption spectroscopy (ETAAS) and inductively-coupled plasma mass spectrometry (ICP-MS) are capable of analysing selenium in medical samples with detection limits in the range from 0.02 to 0.7 μg/l. Since in many cases less complicated and expensive analytical techniques are required, TXRF has been tested regarding its suitability for selenium analysis in different medical, food basics and dietary supplement samples applying most simple sample preparation techniques. The reported results indicate that the accurate analysis of selenium in all sample types is possible. The detection limits of TXRF are in the range from 7 to 12 μg/l for medical samples and 0.1 to 0.2 mg/kg for food basics and dietary supplements. Although this sensitivity is low compared to established techniques, it is sufficient for the physiological concentrations of selenium in the investigated samples.

  1. Selenium speciation in ground water

    SciTech Connect

    Atalay, A.

    1990-07-10

    Selenium toxicity diseases in animals may occur when the intake exceeds 4 mg/kg and selenium deficiency symptoms may occur when dietary intake is less than 0.04 mg/kg. Since the selenium dietary requirement is very close to toxic concentration, it is important to understand the distribution of selenium in the environment. Selenium occurs in four oxidation states (-II, 0, +IV, and +VI) as selenide, elemental selenium, selenite and selenate. Selenate is reported as more soluble and less adsorbed than selenite. Selenate is more easily leached from soils and is the most available form for plants. Increased mobility of Se into the environment via anthropogenic activities, and the potential oxidation-reduction behavior of the element have made it imperative to study the aquatic chemistry of Se. For this purpose, Se species are divided into two different categories: dissolved Se (in material that passes through filters with 0.45 u openings) and particulate Se (in material of particle size > 0.45 mm) typically suspended sediment and other suspended solids. Element and colloidal phase, not truly dissolved, but passing through the filter is deemed to consist of selenium (-2,0). In dissolved state selenium may exist in three of its four oxidation states; Se(-II), Se(+IV), and Se(+VI). Particulate Se may exist in the same oxidation states as dissolved Se and can be found in different phases of the particulate matter. In sediments, Se may be within the organic material, iron and manganese oxides, carbonates or other mineral phases. The actual chemical forms of Se may be adsorbed to or coprecipitated with these phases (primarily selenite, SeO{sub 3}{sup 2{minus}}) and selenate, SeO{sub 4}{sup 2{minus}}. Selenide, Se(-II), can be covalently bound in the organic portion of a sediment. In addition, Se may be found in anoxic sediments as insoluble metal selenide precipitates, an insoluble elemental Se or as ferroselite (FeSe{sub 2}) and Se containing pyrite.

  2. Effect of Dietary Selenomethionine Supplementation on Growth Performance, Tissue Se Concentration, and Blood Glutathione Peroxidase Activity in Kid Boer Goats.

    PubMed

    Song, Yu-xuan; Hou, Jin-xing; Zhang, Lei; Wang, Jian-gang; Liu, Xiao-rui; Zhou, Zhan-qin; Cao, Bin-yun

    2015-10-01

    We used 240 kid Boer goats that were divided into six groups. The control group was fed a basal diet containing 0.05 mg of selenium (Se)/kg dry matter (DM). Trial groups received the basal diet supplemented with 0.1, 0.2, 0.3, 0.4, or 0.5 mg Se/kg DM (using a commercial selenomethionine product). Trial groups showed an improvement in growth performance (P < 0.05) despite no change in average daily feed intakes (ADFIs) (P > 0.05) compared to the control group A, quadratic model showed a correlation between glutathione peroxidase activity level in whole blood and dietary Se concentration (R(2) = 0.883, P < 0.04). The best linear model showed that increasing concentrations of Se in the blood (R(2) = 0.968, P < 0.001) and muscle (R(2) = 0.942, P < 0.001) corresponded to increasing Se concentrations in feed. Accumulation of Se in different tissues and organs corresponded to increasing Se concentrations in the diet as well as to the total time goats spent feeding on supplemented diet. Kidney and muscle tissues showed the highest and lowest accumulation of Se, respectively. Thus, Se in goat meat can be increased by adding between 0.1 and 0.5 mg/kg of selenomethionine to the diet of goats. PMID:25813835

  3. Selenium/interconnected porous hollow carbon bubbles composites as the cathodes of Li-Se batteries with high performance.

    PubMed

    Zhang, Jingjing; Fan, Long; Zhu, Yongchun; Xu, Yanhua; Liang, Jianwen; Wei, Denghu; Qian, Yitai

    2014-11-01

    A kind of Se/C nanocomposite is fabricated by dispersing selenium in interconnected porous hollow carbon bubbles (PHCBs) via a melt-diffusion method. Such PHCBs are composed of porous hollow carbon spheres with a size of ∼70 nm and shells of ∼12 nm thickness interconnected to each other. Instrumental analysis shows that the porous shell of the PHCBs could effectively disperse and sequester most of the selenium, while the inner cavity remains hollow. When evaluated as cathode materials in a carbonate-based electrolyte for Li-Se batteries, the Se/PHCBs composites exhibit significantly excellent cycling performance and a high rate capability. Especially, the Se/PHCBs composite with an optimal content of ∼50 wt% selenium (Se50/PHCBs) displays a reversible discharge capacity of 606.3 mA h g(-1) after 120 cycles at 0.1 C charge-discharge rate. As the current density increased from 0.1 to 1 C (678 mA g(-1)), the reversible capacity of the Se50/PHCBs composite can still reach 64% of the theoretical capacity (431.9 mA h g(-1)). These outstanding electrochemical features should be attributed to effective sequestration of Se in the PHCBs, as well as to the ability to accommodate volume variation and enhance the electronic transport by making Se have close contact with the carbon framework. PMID:25233292

  4. The immune system is limited by oxidative stress: Dietary selenium promotes optimal antioxidative status and greatest immune defense in pacu Piaractus mesopotamicus.

    PubMed

    Biller-Takahashi, Jaqueline D; Takahashi, Leonardo S; Mingatto, Fábio E; Urbinati, Elisabeth C

    2015-11-01

    Reactive oxygen species (ROS) are reactive molecules containing oxygen, that form as byproducts of aerobic metabolism, including immune system processes. Too much ROS may cause oxidative stress. In this study, we examined whether it can also limit the production of immune system compounds. To assess the relationship between antioxidant status and immunity we evaluated the effect of dietary supplementation with organic selenium, given at various levels for 10 days, on the antioxidant and immune system of the pacu fish (Piaractus mesopotamicus). Fish fed a diet containing 0.6 mg Se-yeast kg(-1) showed significant improvement in antioxidant status, as well as in hematological and immunological profiles. Specifically, they had the highest counts for catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), red blood cells, and thrombocytes; the highest leukocyte count (particularly for monocytes); and the highest serum lysozyme activity. There was also a positive correlation between GPx and lysozyme in this group of fish. These findings indicate that short-term supplementation with 0.6 mg Se-yeast kg(-1) reestablished the antioxidative status, allowing the production of innate components which can boost immunity without the risk of oxidative stress. This study shows a relationship between oxidative stress and immunity, and, from a practical perspective, shows that improving immunity and health in pacu through the administration of selenium could improve their growth performance. PMID:26370542

  5. Dietary supplementation of organic selenium could improve performance, antibody response, and yolk oxidative stability in laying hens fed on diets containing oxidized fat.

    PubMed

    Laika, M; Jahanian, R

    2015-06-01

    The present study was carried out to investigate the effect of dietary supplementation of organic selenium (Se) on performance, egg quality indices, and yolk oxidative stability in laying hens fed diets with different fat sources. A total of 270 Hy-line W-36 Leghorn hens of 47 weeks of age were randomly distributed into the 5 replicate cages of 9 dietary treatments. Experimental diets consisted of a 3 × 3 factorial arrangement of treatments with three different fat sources (soybean oil, SO; yellow grease, YG; and palm fat powder, PFP) and three different levels of supplemental Se (0, 0.2, and 0.4 mg/kg of diet) as supplied by zinc-L-selenomethionine (ZnSeMet) complex, which fed during a 77-day feeding trial including 7 days for adaptation and 70 days as the main recording period. Results showed that the highest (P < 0.05) egg weights assigned to the hens fed on SO-supplemented diets. Hen-day egg production was affected by both dietary fat source (P < 0.01) and Se level (P < 0.05) throughout the trial period. Regardless of dietary fat source, dietary supplementation of ZnSeMet improved (P < 0.05) egg mass during all trial periods. Moreover, the significant (P < 0.05) fat  source× Se interactions were observed for egg mass, so that dietary supplementation with 0.4 mg/kg Se was more effective in diets supplemented with YG. Although feed intake was not affected by experimental diets during the first 35-day period, dietary inclusion of PFP reduced feed intake during both second 35-day (P < 0.01) and entire trial period (P < 0.05). The best (P < 0.01) feed conversion ratio during the first 35-day period was assigned to the birds fed on SO-diets, followed by those fed YG-diets. Dietary supplementation of ZnSeMet improved (P < 0.05) feed efficiency during the first 35-day period. Supplementation of ZnSeMet into the diets increased yolk index, with more impact in hens fed on YG-diets. The highest concentration of yolk

  6. Effect of dietary selenium and cancer cell xenograft on peripheral T and B lymphocytes in adult nude mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is known to regulate tumorigenesis and immunity at nutritional and supranutritional levels. Because the immune system provides critical defenses against cancer and the athymic, immune-deficient NU/J nude mice are known to gradually develop CD8+ and CD4+ T cells, we asked whether B and ...

  7. Microbial Selenium Nanoparticles (SeNPs) and Their Application as a Sensitive Hydrogen Peroxide Biosensor.

    PubMed

    Prasad, Kumar Suranjit; Vaghasiya, Jayraj V; Soni, Saurabh S; Patel, Jitesh; Patel, Rinkesh; Kumari, Madhu; Jasmani, Falguni; Selvaraj, Kaliaperumal

    2015-11-01

    The cell-free extract, a crude enzyme (cytosolic and membrane fraction) obtained from an environmental isolate, Bacillus pumilus sp. BAB-3706 worked as excellent in reducing as well as stabilizing agent and facilitated the formation of stable colloidal selenium nanoparticles (SeNPs). Resulting nanoparticles were characterized using UV-vis spectrophotometer, TEM, EDAX, FT-IR and XRD, respectively. A working electrode was modified by coating the surface of indium tin oxide (ITO) with colloidal SeNPs. Successive additions of H2O2 (100 to 600 μM) in conventional three electrodes system, cyclic voltammeter with potential scan rate 25.0 mV/s, in 0.1 M phosphate buffer solution (PBS) yielded increase in current. A perpetual amperometric response at fixed potential (-1.0 V) and at selected time interval of 100 s showed different magnitude of current at every addition of H2O2. The linear range of detection of H2O2 was from 5 to 600 mM (R(2) = 0.9965), while the calculated limit of detection was found to be 3.00 μM. The current study suggested that microbial SeNPs can be used for fabrication of low cost, sensitive H2O2 biosensor. PMID:26319569

  8. Reaction of Laser-Ablated Uranium and Thorium Atoms with H2Se: A Rare Example of Selenium Multiple Bonding.

    PubMed

    Vent-Schmidt, Thomas; Andrews, Lester; Thanthiriwatte, K Sahan; Dixon, David A; Riedel, Sebastian

    2015-10-19

    The compounds H2ThSe and H2USe were synthesized by the reaction of laser-ablated actinide metal atoms with H2Se under cryogenic conditions following the procedures used to synthesize H2AnX (An = Th, U; X = O, S). The molecules were characterized by infrared spectra in an argon matrix with the aid of deuterium substitution and electronic structure calculations at the density functional theory level. The main products, H2ThSe and H2USe, are shown to have a highly polarized actinide-selenium triple bond, as found for H2AnS on the basis of electronic structure calculations. There is an even larger back-bonding of the Se with the An than found for the corresponding sulfur compounds. These molecules are of special interest as rare examples of multiple bonding of selenium to a metal, particularly an actinide metal. PMID:26418218

  9. Selenium (Se) improves drought tolerance in crop plants--a myth or fact?

    PubMed

    Ahmad, Rashid; Waraich, Ejaz Ahmad; Nawaz, Fahim; Ashraf, Muhammad Y; Khalid, Muhammad

    2016-01-30

    Climate change has emerged as one of the most complex challenges of the 21st century and has become an area of interest in the past few decades. Many countries of the world have become extremely vulnerable to the impacts of climate change. The scarcity of water is a serious concern for food security of these countries and climate change has aggravated the risks of extreme events like drought. Oxidative stress, caused by a variety of active oxygen species formed under drought stress, damages many cellular constituents, such as carbohydrates, lipids, nucleic acids and proteins, which ultimately reduces plant growth, respiration and photosynthesis. Se has become an element of interest to many biologists owing to its physiological and toxicological importance. It plays a beneficial role in plants by enhancing growth, reducing damage caused by oxidative stress, enhancing chlorophyll content under light stress, stimulating senesce to produce antioxidants and improving plant tolerance to drought stress by regulating water status. Researchers have adopted different strategies to evaluate the role of selenium in plants under drought stress. Some of the relevant work available regarding the role of Se in alleviating adverse effect of drought stress is discussed in this paper. PMID:25906838

  10. Design, Synthesis, and Biological Evaluation of Novel Selenium (Se-NSAID) Molecules as Anticancer Agents.

    PubMed

    Plano, Daniel; Karelia, Deepkamal N; Pandey, Manoj K; Spallholz, Julian E; Amin, Shantu; Sharma, Arun K

    2016-03-10

    The synthesis and anticancer evaluation of novel selenium-nonsteroidal anti-inflammatory drug (Se-NSAID) hybrid molecules are reported. The Se-aspirin analogue 8 was identified as the most effective agent in reducing the viability of different cancer cell lines, particularly colorectal cancer (CRC) cells, was more selective toward cancer cells than normal cells, and was >10 times more potent than 5-FU, the current therapy for CRC. Compound 8 inhibits CRC growth via the inhibition of the cell cycle in G1 and G2/M phases and reduces the cell cycle markers like cyclin E1 and B1 in a dose dependent manner; the inhibition of the cell cycle may be dependent on the ability of 8 to induce p21 expression. Furthermore, 8 induces apoptosis by activating caspase 3/7 and PARP cleavage, and its longer exposure causes increase in intracellular ROS levels in CRC cells. Taken together, 8 has the potential to be developed further as a chemotherapeutic agent for CRC. PMID:26750401

  11. Characterization of a selenium-tolerant rhizosphere strain from a novel Se-hyperaccumulating plant Cardamine hupingshanesis.

    PubMed

    Tong, Xinzhao; Yuan, Linxi; Luo, Lei; Yin, Xuebin

    2014-01-01

    A novel selenium- (Se-) hyperaccumulating plant, Cardamine hupingshanesis, accumulating Se as a form of SeCys2, was discovered in Enshi, Hubei, China, which could not be explained by present selenocysteine methyltransferase (SMT) theory. However, it is interesting to investigate if rhizosphere bacteria play some roles during SeCys2 accumulation. Here, one Se-tolerant rhizosphere strain, Microbacterium oxydans, was isolated from C. hupingshanesis. Phylogenetic analysis and 16S rRNA gene sequences determined the strain as a kind of Gram positive bacillus and belonged to the family Brevibacterium frigoritolerans. Furthermore, Se tolerance test indicated the strain could grow in extreme high Se level of 15.0 mg Se L(-1). When exposed to 1.5 mg Se L(-1), SeCys2 was the predominant Se species in the bacteria, consistent with the Se species in C. hupingshanesis. This coincidence might reveal that this strain played some positive effect in SeCys2 accumulation of C. hupingshanesis. Moreover, when exposed to 1.5 mg Se L(-1) or 15.0 mg Se L(-1), As absorption diminished in the logarithmic phase. In contrast, As absorption increased when exposed to 7.5 mg Se L(-1), indicating As metabolism processes could be affected by Se on this strain. The present study provided a sight on the role of rhizosphere bacteria during Se accumulation for Se-hyperaccumulating plant. PMID:25478582

  12. Effect of dietary α-tocopherol + ascorbic acid, selenium, and iron on oxidative stress in sub-yearling Chinook salmon (Oncorhynchus tshawytscha Walbaum)

    USGS Publications Warehouse

    Welker, T.L.; Congleton, J.L.

    2009-01-01

    A three-variable central composite design coupled with surface-response analysis was used to examine the effects of dietary ??-tocopherol + ascorbic acid (TOCAA), selenium (Se), and iron (Fe) on indices of oxidative stress in juvenile spring Chinook salmon. Each dietary factor was tested at five levels for a total of fifteen dietary combinations (diets). Oxidative damage in liver and kidney (lipid peroxidation, protein carbonyls) and erythrocytes (erythrocyte resistance to peroxidative lysis, ERPL) was determined after feeding experimental diets for 16 (early December) and 28 (early March) weeks. Only TOCAA influenced oxidative stress in this study, with most measures of oxidative damage decreasing (liver lipid peroxidation in December and March; ERPL in December; liver protein carbonyl in March) with increasing levels of TOCAA. We also observed a TOCAA-stimulated increase in susceptibility of erythrocytes to peroxidative lysis in March at the highest levels of TOCAA. The data suggest that under most circumstances a progressive decrease in oxidative stress occurs as dietary TOCAA increases, but higher TOCAA concentrations can stimulate oxidative damage in some situations. Higher levels of TOCAA in the diet were required in March than in December to achieve comparable levels of protection against oxidative damage, which may have been due to physiological changes associated with the parr-smolt transformation. Erythrocytes appeared to be more sensitive to variation in dietary levels of TOCAA than liver and kidney tissues. Using the March ERPL assay results as a baseline, a TOCAA level of approximately 350-600 mg/kg diet would provide adequate protection against lipid peroxidation under most circumstances in juvenile Chinook salmon. ?? 2008 The Authors.

  13. Effects of Gestational Exposure to Methylmercury and Dietary Selenium on Reinforcement Efficacy in Adulthood

    PubMed Central

    Reed, Miranda N.; Banna, Kelly M.; Donlin, Wendy D.; Newland, M. Christopher

    2008-01-01

    It has recently been demonstrated that developmental exposure to methylmercury (MeHg) is associated with perseveration on operant tasks. An understanding of the behavioral mechanisms underlying this phenomenon may improve human testing of MeHg exposures and could provide insight into clinical syndromes that include perseveration as a component. One possible mechanism is that MeHg-induced enhancement of reinforcer efficacy produces a “reinforcement trap” that inhibits change in novel situations. Rats were exposed gestationally to 0, 0.5 or 5 ppm mercury (Hg) as MeHg via maternal drinking water. They also received a diet during gestation and throughout life that was marginal (0.06 ppm) or rich (0.6 ppm) in selenium (Se), a nutrient believed to protect against MeHg's toxicity. Reinforcer efficacy was evaluated using a progressive ratio schedule of reinforcement during adulthood. Maximum ratio obtained (MRO) was determined using 20 or 60 mg sucrose pellets and with ratio requirements that increased at 5% or 20% per reinforcer. MRO was related to the rate at which the ratio increased, reinforcer magnitude, sex, and exposure regimen; MRO was increased for the 0.6 ppm Se, 5 ppm Hg group. This extends an earlier observation that developmental MeHg exposure enhances reinforcer efficacy, an effect that could be related to reports of perseveration. PMID:18096364

  14. Effects of dietary selenium supplementation on parasitemia, anemia and serum proteins of Trypanosoma brucei brucei infected rats.

    PubMed

    Eze, J I; Okeke, M C; Ngene, A A; Omeje, J N; Abonyi, F O

    2013-10-01

    Trypanosomosis has been associated with immunosuppression, anemia and oxidative damage while selenium possesses both immunostimulatory and antioxidative effects. This study was designed to assess the effect of dietary selenium supplementation on parasitemia, anemia, survival pattern and serum protein profiles of trypanosome-infected rats. Twenty five rats, divided into five groups (A-E) of 5 each, were treated as follows: 4, 8 and 16 ppm (ppm) of selenium in their feed, respectively throughout the experimental period and were infected with Trypanosoma brucei brucei on day 14 post supplementation, infected not supplemented and the negative control. Supplementation at 4 and 8 ppm increased the packed cell volume (PCV) and hemoglobin (Hb) concentration on day 7 of supplementation (PS) when compared with the unsupplemented groups. Following infection on day 14 PS, the PCV, Hb of 16 ppm and infected not supplemented groups were significantly (P < 0.05) lower than other groups on days 28 and 35 PS. Supplementation did not lead to significant (P > 0.05) changes on the total protein, albumin and globulin by day 14 PS. Infection, however, caused significant (P > 0.05) decrease in the total protein and albumin from day 28. The supplementation did not significantly (P > 0.05) increase the pre-patent period but caused a significant reduction in the parasitemia levels and increased survival intervals. Dietary selenium supplementation, from the results, may show promise in the management of African trypanosomosis as the supplementation was able to: reduce anemia and parasitemia and increase survival intervals of trypanosome infected rats. PMID:23916765

  15. Selenium assimilation and loss by an insect predator and its relationship to Se subcellular partitioning in two prey types.

    PubMed

    Dubois, Maïtée; Hare, Landis

    2009-03-01

    Subcellular selenium (Se) distributions in the oligochaete Tubifex tubifex and in the insect Chironomus riparius did not vary with Se exposure duration, which was consistent with the observations that the duration of prey Se exposure had little influence on either Se assimilation or loss by a predatory insect (the alderfly Sialis velata). However, these two prey types differed in how Se was distributed in their cells. Overall, the predator assimilated a mean of 66% of the Se present in its prey, which was similar to the mean percentage of Se in prey cells (62%) that was theoretically available for uptake (that is, Se in the protein and organelle fractions). Likewise, data for cadmium, nickel and thallium suggest that predictions of trace element transfer between prey and predator are facilitated by considering the subcellular partitioning of these contaminants in prey cells. PMID:19110352

  16. Daily selenium intake in a moderate selenium deficiency area of Suzhou China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Daily dietary selenium (Se) intake in Suzhou China was investigated to determine whether residents were susceptible to Se deficiency. Food samples were purchased from local supermarkets, including vegetables, fruits, meats and seafood. Hair samples were collected from 285 people ranging from 20 to ...

  17. Dietary selenium affects homocysteine metabolism differently in Fisher-344 rats and CD-1 mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our previous work showed that plasma and tissue homocysteine concentrations are decreased by selenium deprivation in rats. The purpose of this study was to follow up and expand on that work by determining the effects of selenium status (deficient, adequate, and supranutritional) on key aspects of ho...

  18. Effect of dietary selenium on T cell immunity and cancer xenograft in nude mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium is known to regulate carcinogenesis and immunity at nutritional and supranutritional levels. Because the immune system provides one of the main body defenses against cancer, we asked whether T cell immunity can modulate selenium chemoprevention. Twenty-four homozygous NU/J nude mice were fe...

  19. Selenium Characterization In The Global Rice Supply Chain

    EPA Science Inventory

    For up to 1 billion people worldwide, insufficient dietary intake of selenium (Se) is a serious health constraint. Cereals are the dominant Se source for those on low protein diets, as typified by the global malnourished population. With crop Se content constrained largely by u...

  20. Effects of selenium supply and dietary restriction on maternal and fetal metabolic hormones in pregnant ewe lambs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives were to evaluate effects of dietary restriction and Se on maternal and fetal metabolic hormones. In Exp. 1, pregnant ewe lambs (n = 32; initial BW = 45.6 ± 2.3 kg) were allotted randomly to 1 of 4 treatments. Diets contained (DM basis) either no added Se (control), or supranutritional Se ...

  1. Impact of selenium supply on se-methylselenocysteine and glucosinolates accumulation in selenium-biofortified brassica sprouts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brassica sprouts are widely marketed as functional foods. Here we examined the effects of Se treatment on the accumulation of anticancer compound Se-methylselenocysteine (SeMSCys) and glucosinolates in Brassica sprouts. Cultivars from the six most extensively consumed Brassica vegetables (broccoli, ...

  2. Distribution of selenium in zebrafish larvae after exposure to organic and inorganic selenium forms.

    PubMed

    Dolgova, N V; Hackett, M J; MacDonald, T C; Nehzati, S; James, A K; Krone, P H; George, G N; Pickering, I J

    2016-03-01

    Selenium is an essential micronutrient for many organisms, and in vertebrates has a variety of roles associated with protection from reactive oxygen species. Over the past two decades there have been conflicting reports upon human health benefits and detriments arising from consumption of selenium dietary supplements. Thus, early studies report a decrease in the incidence of certain types of cancer, whereas subsequent studies did not observe any anti-cancer effect, and adverse effects such as increased risks for type 2 diabetes have been reported. A possible contributing factor may be that different chemical forms of selenium were used in different studies. Using larval stage zebrafish (Danio rerio) as a model organism, we report a comparison of the toxicities and tissue selenium distributions of four different chemical forms of selenium. We find that the organic forms of selenium tested (Se-methyl-l-selenocysteine and l-selenomethionine) show considerably more toxicity than inorganic forms (selenite and selenate), and that this appears to be correlated with the level of bioaccumulation. Despite differences in concentrations, the tissue specific pattern of selenium accumulation was similar for the chemical forms tested; selenium was found to be highly concentrated in pigment (melanin) containing tissues especially for the organic selenium treatments, with lower concentrations in eye lens, yolk sac and heart. These results suggest that pigmented tissues might serve as a storage reservoir for selenium. PMID:26781816

  3. On-line pre-reduction of Se(VI) by thiourea for selenium speciation by hydride generation

    NASA Astrophysics Data System (ADS)

    Qiu, Jianhua; Wang, Qiuquan; Ma, Yuning; Yang, Limin; Huang, Benli

    2006-07-01

    In this study, thiourea (TU) was novelly developed as a reduction reagent for on-line pre-reduction of selenium(VI) before conventional hydride generation (HG) by KBH 4/NaOH-HCl. After TU on-line pre-reduction, the HG efficiency of Se(VI) has been greatly improved and because even higher than that of the same amount of Se(IV) obtained in the conventional HG system. The possible pre-reduction mechanism is discussed. The detection limit (DL) of selenate reaches 10 pg mL - 1 when using on-line TU pre-reduction followed by HG atomic fluorescence detection. When TU pre-reduction followed by HG is used as an interface between ion-pair high performance liquid chromatography and atomic fluorescence spectrometry, selenocystine, selenomethionine, selenite and selenate can be measured simultaneously and quantitatively. The DLs of these are 0.06, 0.08, 0.05 and 0.04 ng mL - 1 , respectively, and the relative standard deviations of 9 duplicate runs for all the 4 species are less than 5%. Furthermore, it was successfully applied to Se speciation analysis of cultured garlic samples, and validated by determination of total selenium and selenium species in certified reference material NIST 1946.

  4. Effect of dietary supplementation with different sources of selenium on growth response, selenium blood levels and meat quality of intensively finished Charolais young bulls.

    PubMed

    Cozzi, G; Prevedello, P; Stefani, A L; Piron, A; Contiero, B; Lante, A; Gottardo, F; Chevaux, E

    2011-08-01

    The study aimed at comparing three strategies of supplementing selenium (Se) during the finishing period of Charolais young bulls: (1) administration of sodium selenite throughout the finishing (NaSe); (2) administration of an Se-enriched yeast strain (Saccharomyces cerevisiae NCYC R397) throughout the finishing (Se-Y); (3) administration of sodium selenite for 140 days replaced by Se-enriched yeast during the last 70 days of finishing (Switch). Eighty-four young bulls (mean initial BW=434.2±31.9 kg; mean age=382±52 days) were stratified by live weight and equally assigned to one of three Se treatments. Experimental groups were fed the same diets and the inclusion rate of the different treatments was targeted to achieve 0.3 mg of Se/kg of dry matter (DM) in the complete feed. The average daily gain of bulls was 1.36 kg/d and no differences due to Se treatment were recorded. Dry matter intake and feed conversion ratio were not affected by Se treatment resulting in, on average, 10.3 kg/d and 7.65, respectively. Repeated blood samples were taken at days 0, 120, 180 and 210 of finishing to assess the Se status of the animals. As compared to NaSe, both organic Se treatments (Se-Y and Switch) increased plasma Se in the last two sampling sessions according to a significant treatment×time interaction (P<0.001). A similar trend was observed for serum total antioxidant status of the young bulls, whereas there was only a significant time effect (P<0.001) on glutathione peroxidase activity that was raised by all Se treatments. The finishing period lasted 210 days and at the abattoir there were no differences across Se treatments in carcass weight and dressing percentage. A higher Se content in the Longissimus thoracis (LT) muscle was instead observed in Se-Y samples as compared with NaSe (0.85 v. 0.47 mg/kg DM; P<0.05). Meat quality evaluation was carried out on LT samples after 6 and 11 days of ageing under a vacuum package. Regardless of ageing time, meat from young bulls

  5. Effect of selenium-saturated bovine lactoferrin (Se-bLF) on antioxidant enzyme activities in human gut epithelial cells under oxidative stress.

    PubMed

    Burrow, Hannah; Kanwar, Rupinder K; Mahidhara, Ganesh; Kanwar, Jagat R

    2011-10-01

    observed immediately, showing capability of Se-bLF being highly beneficial in helping to maintain a balance between the oxidant/antioxidant systems within cells and tissues, especially in selenium deficient systems. In conclusion, the antioxidative defence activity of Se-bLf, investigated in this study for the first time, shows dynamic adaptations that may allow for essential protection from the imbalanced oxidative conditions. Because of its lack of toxicity and the availability of both selenium and bLF in whole milk, Se-bLF offers a promise for a prospective natural dietary supplement, in addition to being an immune system enhancement, or a potential chemopreventive agent for cancers. PMID:21919840

  6. Effect of selenium (Se) deficiency on the anti-malarial action of Qinghaosu (QHS) in mice

    SciTech Connect

    Levander, O.A.; Ager, A.L.; May, R.

    1986-03-01

    QHS is an endoperoxide, so it occurred to the authors that its anti-malarial action might be potentiated by low glutathione peroxidase (GSH-Px) activity. Weanling female mice were fed 1 of 4 diets: chow or a Torula yeast-based diet supplemented with 0, 0.1 or 0.5 ppm Se as Na/sub 2/SeO/sub 3/. After 6 weeks, mean hepatic GSH-Px activities and plasma Se levels in these 4 dietary groups were 17.3, 0.1, 5.4, and 14.5 munits/mg protein and 242, 4, 230, and 532 ng/ml, respectively. At this time, all mice were inoculated i.p. with asexual blood stages of Plasmodium yoelii. Then groups of 7 or 8 mice fed each diet were given 0, 4, 16, or 64 mg QHS/kg orally bid at 3, 4, and 5 days post inoculation. On the 6th day, blood films were taken and antimalarial activity was assessed by determining % parasitemia (% PARA). Mice given 0 or 4 mg QHS/kg averaged 47% PARA and this was not affected by diet. Mice receiving 64 mg QHS/kg averaged about 1% PARA irrespective of diet. However, mice given 16 mg QHS/kg had 25% PARA when fed chow but only 8 to 11% PARA when fed the Torula diet, regardless of Se intake. Thus, while Se status did not appear to influence the antimalarial potency of QHS, some factor(s) in the Torula diet enhanced its activity at intermediate doses vs. the chow diet.

  7. Simultaneous removal of SO2 and trace SeO2 from flue gas: effect of SO2 on selenium capture and kinetics study.

    PubMed

    Li, Yuzhong; Tong, Huiling; Zhuo, Yuqun; Wang, Shujuan; Xu, Xuchang

    2006-12-15

    Sulfur dioxide (SO2) and trace elements are all pollutants derived from coal combustion. This study relates to the simultaneous removal of SO2 and trace selenium dioxide (SeO2) from flue gas by calcium oxide (CaO) adsorption in the moderate temperature range, especially the effect of SO2 presence on selenium capture. Experiments performed on a thermogravimetric analyzer (TGA) can reach the following conclusions. When the CaO conversion is relatively low and the reaction rate is controlled by chemical kinetics, the SO2 presence does not affect the selenium capture. When the 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 the selenium capture. On the basis of the kinetics study, a method to estimate the trace selenium removal efficiency using kinetic parameters and the sulfur removal efficiency is developed. PMID:17256549

  8. Selection of salt and boron tolerant selenium hyperaccumulator Stanleya pinnata genotypes and characterization of Se phytoremediation from agricultural drainage sediments.

    PubMed

    Freeman, John L; Bañuelos, Gary S

    2011-11-15

    Genetic variation in salt (Na(2)SO(4), NaCl) and boron (B) tolerance among four ecotypes of the selenium (Se) hyperaccumulator Stanleya pinnata (Pursh) Britton was utilized to select tolerant genotypes capable of phytoremediating Se from salt, B, and Se-laden agricultural drainage sediment. The few individual salt/B tolerant genotypes were successfully selected from among a large population of highly salt/B sensitive seedlings. The distribution, hyperaccumulation, and volatilization of Se were then examined in selected plants capable of tolerating the high salt/B laden drainage sediment. Salt/B tolerant genotypes from each of the four ecotypes had mean Se concentrations ranging from 2510 ± 410 to 1740 ± 620 in leaves and 3180 ± 460 to 2500 ± 1060 in seeds (μg Se g(-1) DW ± SD), while average daily Se volatilization rates ranged from 722 ± 375 to 1182 ± 575 (μg Se m(-2) d(-1) ± SD). After two growing seasons (∼18 months), we estimated that hyperaccumulation and volatilization of Se by tolerant S. pinnata genotypes and their associated microbes can remove approximately 30% of the total soil Se in 0-30 cm sediment. The salt/B tolerant S. pinnata genotypes selected and characterized herein represent promising new tools for the successful phytoremediation of Se from salt/B and Se-laden agricultural drainage sediments. PMID:21988205

  9. Effects of dietary selenium and vitamin E on immune response and biological blood parameters of broilers reared under thermoneutral or heat stress conditions

    NASA Astrophysics Data System (ADS)

    Habibian, Mahmood; Ghazi, Shahab; Moeini, Mohammad Mehdi; Abdolmohammadi, Alireza

    2014-07-01

    A study was conducted using 360 broiler chickens to evaluate the effects of dietary vitamin E (0, 125 and 250 mg/kg), selenium (Se, 0, 0.5 and 1 mg/kg), or their different combinations on immune response and blood biological parameters of broilers raised under either thermoneutral (TN, 23.9 °C constant) or heat stress (HS, 23.9 to 37 °C cycling) conditions. Humoral immunity was assessed by intravenous injection of 7 % sheep red blood cell (SRBC) followed by evaluation of serum for antibody titers in primary and secondary responses. Heterophil to lymphocyte (H/L) ratio also determined as an indicator of stress. Furthermore, at the end of the experiment, birds were bled for determination of some biological parameters. There was a significant reduction in body weight and feed intake, but the feed conversion ratio increased when the birds were exposed to HS ( P < 0.05). Body weight and feed intake were not influenced significantly by dietary vitamin E and Se ( P > 0.05), whereas feed conversion was improved significantly by 125 mg/kg vitamin E ( P < 0.05). The liver and lymphoid organ weights as well as IgM and IgG, antibody titers for primary and secondary antibody responses to SRBC were reduced significantly under HS ( P < 0.05). Heat stress also resulted in a significant increase in H/L ratio ( P < 0.05). Dietary vitamin E resulted in improvement of primary and secondary antibody responses both in TN and HS broilers ( P < 0.05). The HS birds also showed an improved antibody titer in secondary response with high concentration of Se ( P < 0.05). Vitamin E and Se had interactive effects on anti-SRBC titers; however, no consistent differences were found between dietary levels during the study. The H/L ratio decreased by feeding vitamin E at both levels either under HS or TN conditions ( P < 0.05). The serum concentrations of glucose, triglycerides, total cholesterol, and LDL-cholesterol were increased but serum HDL-cholesterol decreased in HS broilers ( P < 0.05).

  10. Selenium speciation in ground water. Quarterly report

    SciTech Connect

    Atalay, A.

    1990-07-10

    Selenium toxicity diseases in animals may occur when the intake exceeds 4 mg/kg and selenium deficiency symptoms may occur when dietary intake is less than 0.04 mg/kg. Since the selenium dietary requirement is very close to toxic concentration, it is important to understand the distribution of selenium in the environment. Selenium occurs in four oxidation states (-II, 0, +IV, and +VI) as selenide, elemental selenium, selenite and selenate. Selenate is reported as more soluble and less adsorbed than selenite. Selenate is more easily leached from soils and is the most available form for plants. Increased mobility of Se into the environment via anthropogenic activities, and the potential oxidation-reduction behavior of the element have made it imperative to study the aquatic chemistry of Se. For this purpose, Se species are divided into two different categories: dissolved Se (in material that passes through filters with 0.45 u openings) and particulate Se (in material of particle size > 0.45 mm) typically suspended sediment and other suspended solids. Element and colloidal phase, not truly dissolved, but passing through the filter is deemed to consist of selenium (-2,0). In dissolved state selenium may exist in three of its four oxidation states; Se(-II), Se(+IV), and Se(+VI). Particulate Se may exist in the same oxidation states as dissolved Se and can be found in different phases of the particulate matter. In sediments, Se may be within the organic material, iron and manganese oxides, carbonates or other mineral phases. The actual chemical forms of Se may be adsorbed to or coprecipitated with these phases (primarily selenite, SeO{sub 3}{sup 2{minus}}) and selenate, SeO{sub 4}{sup 2{minus}}. Selenide, Se(-II), can be covalently bound in the organic portion of a sediment. In addition, Se may be found in anoxic sediments as insoluble metal selenide precipitates, an insoluble elemental Se or as ferroselite (FeSe{sub 2}) and Se containing pyrite.

  11. Cadmium-induced alterations in the antioxidant defense system of the rat eye in relation to dietary selenium intake

    SciTech Connect

    Sinno, J.A.M.

    1989-01-01

    Studies were conducted to investigate the effects of dietary cadmium (Cd)upon enzymatic antioxidant function in the ocular tissues of the albino rat. Activity of glutathione peroxidase (GSH-Px), Se-independent GSH-Px and catalase, and concentrations of thiobarbituric acid-reactive substances (TBARS), glutathione, and the elements Se, Cd and copper (Cu) were determined in ocular tissues from each group. Feeding rats a low Se diet resulted in a significant decrease in GSH-Px activity irrespective of Cd treatment. Activity of Se-independent GSH-Px in rats maintained on the low Se diet decreased when compared to Se-adequate controls. Cd treatment of rats fed low Se resulted in increased activity when compared to low-Se controls. When comparisons were made between ocular TBARS in rats maintained at either level of dietary Se, with or without Cd treatment, decreased ocular TBARS were observed in Cd-treated groups. A significant decrease in the ocular concentration of Se occurred in rats fed 0.05 ppm Se when compared to rats supplemented with 0.10 ppm Se. Administering Cd to the low Se group increased ocular Se levels 100%. A negative correlation between ocular Se concentration and the level of TBARS was observed, suggesting a possible alternate role for Se as an antioxidant in the eye.

  12. Influence of dietary selenium on the disposition of arsenate in the female B6C3F{sub 1} mouse

    SciTech Connect

    Kenyon, E.M.; Hughes, M.F.; Levander, O.A.

    1997-06-27

    Interactions between arsenic (As) and selenium (Se) at the metabolic level are multifaceted and complex. These interactions are of practical significance because populations in various parts of the world are simultaneously exposed to inorganic As in drinking water and Se mainly in the diet at varying levels. The primary goal of this study was to investigate whether differing dietary Se status would alter the profile of urinary metabolites or their time course for elimination after exposure to arsenate [As(V)]. Weanling female 86C3F, mice were maintained for 28 d on either a control diet of powdered rodent meal sufficient in Se (A 0.2 ppm) or Torula yeast-based (TYB) diets deficient (B, 0.02 ppm Se), sufficient (C, 0.2 ppm Se), or excessive (D, 2.0 ppm Se) in Se; mice then received by oral gavage 5 mg (As)/kg as sodium [{sup 73}As] arsenate. The time course for elimination of total arsenic and metabolites in urine was measured over a 48-h period, and total arsenic was determined in feces and tissues at 48 h. Mice on the Se excess diet excreted a significantly higher percentage of urinary As as inorganic As, with a significantly decreased ratio of organic to inorganic As compared to Se-sufficient mice, suggesting that As methylation was decreased. Mice on the Se-deficient diet appeared to eliminate As(V), arsenite, and dimethylarsinic acid (DMA) in urine more slowly than Se-sufficient mice; however, further studies are required to confirm this finding. Mice on the Se-sufficient meal diet (A) excreted significantly less (by percent) arsenate-derived radioactivity in urine and more in feces compared to mice on the Se-sufficient TYB diet (C), with total elimination being similar for both groups. This indicates that mice on the meal diet absorbed significantly less As(V) than mice on the TYB diet, and this may be due to more fiber or {open_quotes}bulk{close_quotes} in the meal diet. 35 refs., 6 figs., 6 tabs.

  13. Dietary Oil Source and Selenium Supplementation Modulate Fads2 and Elovl5 Transcriptional Levels in Liver and Brain of Meagre (Argyrosomus regius).

    PubMed

    Silva-Brito, Francisca; Magnoni, Leonardo J; Fonseca, Sthelio Braga; Peixoto, Maria João; Castro, L Filipe C; Cunha, Isabel; de Almeida Ozório, Rodrigo Otávio; Magalhães, Fernando Antunes; Gonçalves, José Fernando Magalhães

    2016-06-01

    The meagre (Argyrosomus regius) is taking on increasing importance in the aquaculture industry. In view of the limited supply of fish oil (FO) as a feed ingredient, the study of the capacity to biosynthesize long-chain polyunsaturated fatty acids (LC-PUFA) from alternative dietary oil sources is important. We analyzed changes in fatty acid (FA) desaturase 2 (fads2) and FA elongase 5 (elovl5) mRNA levels in livers and brains in response to FO replacement with a blend of vegetable oils (VO) and selenium (Se) supplementation. Fish were fed for 60 days with either a diet containing FO or a diet including VO, each supplemented or not with organic Se. Results showed that fads2 and elovl5 transcription was higher in liver when fish were fed VO diets. The brain mRNA levels of both genes were not affected by the dietary replacement of FO by VO. FA composition in the liver and skeletal muscle was altered by FO replacement, particularly by decreasing eicosapentaenoic acid and docosahexaenoic acid contents. The α-linolenic, linoleic, and arachidonic acid contents increased in both liver and brain of fish fed VO diets. The effect of Se supplementation on lipid metabolism was evident only in fish fed FO, showing a decrease in the transcription of hepatic fads2. Results indicate that the total replacement of FO by VO in diets modulates the expression of genes involved in LC-PUFA biosynthesis in meagre, affecting the FA profile of the fish flesh. PMID:27169705

  14. Oxygen Replacement with Selenium at the Thymidine 4-Position for the Se Base Pairing and Crystal Structure Studies

    SciTech Connect

    Salon,J.; Sheng, J.; Jiang, J.; Chen, G.; Caton-Williams, J.; Huang, Z.

    2007-01-01

    The T-A and C-G base pairing and stacking allow the formation of the stable DNA duplex structure for genetic information storage, transcription, and replication. To replace the oxygen of the nucleotide nucleobases with selenium for the studies of the base-pair recognition, the duplex stability, and the nuclei acid crystal structures, we have synthesized for the first time the 4-Se thymidine phosphoramidite and incorporated it into oligonucleotides via solid-phase synthesis with high coupling yield (99%). The Se modification on the nucleobase is relatively stable under the elevated temperature. Using the dU{sub Se} (2'-Se-dU) to facilitate the crystallization, we have successfully crystallized the DNA containing the 4-Se-T substitution and determined its structure at 1.50 {angstrom} resolution. The UV-melting and X-ray crystal structure studies have indicated that the Se substitution on the nucleobase does not cause a significant structure perturbation, the large Se atom on the thymine can be successfully accommodated by the DNA duplex, and the Se-mediated hydrogen bond (longer than the usual hydrogen bond) is formed within the modified T-A base pair. In addition, the Se derivatization on the nucleobases further facilitates X-ray crystal structure determination of nucleic acids and their protein complexes via Se MAD phasing.

  15. Continued Selenium Biofortification of Carrots and Broccoli Grown in Soils Once Amended with Se-enriched S. pinnata.

    PubMed

    Bañuelos, Gary S; Arroyo, Irvin S; Dangi, Sadikshya R; Zambrano, Maria C

    2016-01-01

    Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton) three and 4 years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0-30 cm) were 1.65 mg kg(-1) and 88 μg L(-1), and 0.92 mg kg(-1) and 48.6 μg L(-1) at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg(-1) and 3.15 to 6.25 mg kg(-1) in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine) was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid fatty acid (PLFA) analyses showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi), actinomycetes and Gram-positive and bacterial PLFA at both 0-5 and 0-30 cm, respectively, 3 years later. Successfully producing Se-enriched broccoli and carrots 3 and 4 years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions. PMID:27602038

  16. Continued Selenium Biofortification of Carrots and Broccoli Grown in Soils Once Amended with Se-enriched S. pinnata

    PubMed Central

    Bañuelos, Gary S.; Arroyo, Irvin S.; Dangi, Sadikshya R.; Zambrano, Maria C.

    2016-01-01

    Selenium (Se) biofortification has been practiced in Se-deficient regions throughout the world primarily by adding inorganic sources of Se to the soil. Considering the use of adding organic sources of Se could be useful as an alternative Se amendment for the production of Se-biofortified food crops. In this multi-year micro-plot study, we investigate growing carrots and broccoli in soils that had been previously amended with Se-enriched Stanleya pinnata Pursh (Britton) three and 4 years prior to planting one and two, respectively. Results showed that total and extractable Se concentrations in soils (0–30 cm) were 1.65 mg kg-1 and 88 μg L-1, and 0.92 mg kg-1 and 48.6 μg L-1 at the beginning of the growing season for planting one and two, respectively. After each respective growing season, total Se concentrations in the broccoli florets and carrots ranged from 6.99 to 7.83 mg kg-1 and 3.15 to 6.25 mg kg-1 in planting one and two, respectively. In broccoli and carrot plant tissues, SeMet (selenomethionine) was the predominant selenoamino acid identified in Se aqueous extracts. In postharvest soils from planting one, phospholipid fatty acid (PLFA) analyses showed that amending the soil with S. pinnata exerted no effect on the microbial biomass, AMF (arbuscular mycorrhizal fungi), actinomycetes and Gram-positive and bacterial PLFA at both 0–5 and 0–30 cm, respectively, 3 years later. Successfully producing Se-enriched broccoli and carrots 3 and 4 years later after amending soil with Se-enriched S. pinnata clearly demonstrates its potential source as an organic Se enriched fertilizer for Se-deficient regions. PMID:27602038

  17. Differential patterns of accumulation and depuration of dietary selenium and vanadium during metamorphosis in the Gray Treefrog (Hyla versicolor).

    PubMed

    Rowe, Christopher L; Heyes, Andrew; Hilton, Jessica

    2011-02-01

    Selenium (Se) and vanadium (V) are contaminants commonly found in aquatic systems affected by wastes derived from fossil fuels. To examine their effects on a widely distributed species of amphibian, we exposed gray tree frogs (Hyla versicolor) to Se (as SeO₂) or V (as NaVO₃) in their diet from the early larval period to metamorphosis. Concentrations of Se in Se-enriched food were 1.0 (Se control), 7.5 (Se low), and 32.7 (Se high) μg/g dw. Concentrations of V in V-enriched food were 3.0 (V control), 132.1 (V low), and 485.7 (V high) μg/g dw. Although we observed bioaccumulation of both metals throughout the larval period, no effects on growth, survival, metabolic rate, or lipid content were observed. Se concentrations in tissues did not vary among life stages, neither in Se low nor Se high treatments, such that maximum accumulation had occurred by the mid-larval period. In addition, there was no evidence of depuration of Se in either the Se low or the Se high treatments during metamorphosis. A strikingly different pattern of accumulation and depuration occurred in V-exposed individuals. In treatments V low and V high, maximum body burdens occurred in "premetamorphs" (i.e., animals with developed forelimbs but in which tail resorption had not begun), whereas body burdens in animals having completed metamorphosis were much lower and similar to those in larvae. These results suggest that compared with Se-exposed animals, V-exposed animals were able to depurate a substantial amount of accumulated V during the metamorphic period. In an ecologic context, it appears that amphibians exposed to Se during the larval period may serve as a vector of the metal to terrestrial predators, yet potential transfer of accumulated V to predators would largely be restricted to the aquatic habitat. PMID:20878520

  18. Metabolism of selenium (Se) in rats chronically poisoned with D- or L-selenomethionine (SeMet), selenite or selenate

    SciTech Connect

    McAdam, P.A.; Levander, O.A.

    1986-03-01

    L-SeMet is a potential cancer chemoprevention agent for humans. Little difference was seen in the acute toxicity of L vs. D-SeMet in rats. To study chronic toxicity, weanling male rats were fed purified diets containing 2.5, 5.0 or 10 ppm Se as L-SeMet, D-SeMet, Na/sub 2/SeO/sub 3/ or Na/sub 2/SeO/sub 4/ for 6 weeks. Controls received 0.1 ppm Se as selenite. All rats fed 10 ppm Se died within 29 days. Se fed as D-SeMet was retained in the tissues as strongly as L-SeMet. Rats fed D or L-SeMet deposited large amounts of Se in muscle not reflected by proportionate increases in either plasma or RBC Se. Therefore, attempts to follow increases in Se body burden in individuals supplemented with large doses of L-SeMet by monitoring plasma or whole blood Se levels should be interpreted with caution.

  19. Biotransformation and accumulation of selenium inside organisms in an engineered aquatic ecosystem designed for bioremediation of Se from agriculture drainage water and brine shrimp production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Excessive selenium (Se) in soils and waters present in the westside of central California was determined to be responsible for ecotoxicities observed in water fowl frequenting large bodies of water, i.e., evaporation ponds. In order to monitor the fate and potentially design an aquatic Se remediatio...

  20. Organosilicon derivatives of selenium containing the Se(CH/sub 2/)/sub n/ Si group

    SciTech Connect

    Voronkov, M.G.; Sorokin, M.S.

    1987-02-10

    Methods were developed for the synthesis of previously unknown organosilicon derivatives of selenium: organyl (trimethyloxysilyl)alkyl selenides, organyl silatranylalkyl selenides, organylmethyl(silatranylmethyl)selenonium iodides, and organyl 2-(trifluorosilyl)ethyl selenides. Some of their chemical reactions, their /sup 1/H NMR and IR spectra, and their toxicities were studied. Alkanethiols catalyze the photochemical addition of selenols to trimethoxyvinylsilane. In competitive reactions of the photochemical addition of isostructural thiols and selenols to trimethoxyvinylsilane only the addition products of selenols are formed.

  1. Effect of Inorganic Dietary Selenium Supplementation on Selenoprotein and Lipid Metabolism Gene Expression Patterns in Liver and Loin Muscle of Growing Lambs.

    PubMed

    Juszczuk-Kubiak, Edyta; Bujko, Kamila; Cymer, Monika; Wicińska, Krystyna; Gabryszuk, Mirosław; Pierzchała, Mariusz

    2016-08-01

    Effect of selenium (Se) supplementation on the selenoprotein and lipid metabolism gene expression patterns in ruminants, especially in lambs is not yet fully understood. The aim of study was to evaluate the effect of Se supplementation on the messenger RNA (mRNA) expression patterns of selected selenoproteins and genes related to lipid metabolism in growing lambs. The experiment was conducted on 48 Polish Merino lambs divided into two groups (n = 24): control (C)-lambs fed with a basal diet (BD) with no Se supplementation, and supplemented (S)-lambs fed with a BD, supplemented with 0.5 mg Se/kg as sodium selenate for 8 weeks. Expression of 12 selenoproteins and six genes related to lipid metabolism was analyzed in the liver and longissimus dorsi (LD) muscle of growing lambs by qPCR. Significant differences were found in the expression of GPX1, GPX2, SEPM, SEPW1, SEP15, SEPGS2, and TXNRD1 in the liver, and GPX1, SEPP1, SEPN1, SEPW1, SEP15, and MSRB1 in the LD muscle between S and C lambs. Se supplementation mainly upregulated SEPW1, SEP15 (P < 0.001; P < 0.01) mRNA expression in the liver, and GPX1, SEPP1, SEPN1, SEPW1 (P < 0.001; P < 0.01) in the muscle of S group. On the other hand, significant decrease in GPX2 (P < 0.01), SEPM (P < 0.001), and SEPHS2 (P < 0.01) mRNA expression levels were observed in the liver of S group of lambs. Se supplementation did not affect PON1, LXRα, and PPARα mRNA expression levels, but a significant increase in mRNA levels of APOE and LPL in the LD muscle (P < 0.05) as well as LPL (P < 0.05) in the liver were noticed in the group of Se supplemented lambs. Our study confirmed that, in lambs, similarly to other species, mRNA expression patterns of several selenoproteins highly depend on dietary Se levels, and their expression is ruled by hierarchical principles and tissue-specific mechanisms. Moreover, the study showed that changes Se intake leads to different levels of genes expression related

  2. Assessing noxious effects of dietary exposure to methylmercury, PCBs and Se coexisting in environmentally contaminated rice in male mice.

    PubMed

    Cheng, Jinping; Yang, Yichen; Ma, Jing; Wang, Wenhua; Liu, Xiaojie; Sakamoto, Mineshi; Qu, Yiya; Shi, Wei

    2009-04-01

    Polychlorinated biphenyls and methylmercury are two of the most ubiquitous environmental contaminants in Guizhou province. Rice is eaten with almost every meal and provides more calories than any single food in Guizhou province. The estimated tolerable daily intake of total mercury, MeHg, Se and PCBs from Guizhou contaminated rice by Chinese people showed that MeHg and/or PCBs exceeded the corresponding limits. The aim of this study was to characterize the effects of exposure to environmental contaminated rice on neurobehavioral development and neurobiological disruptions in mice. Animals were treated from postnatal day (PND) 22 to 91. At PND 26-91 days of age, mice were tested for neurobehavioural development and neurochemical level changes. We showed that dietary exposure to environmentally contaminated rice gave rise to different changes in antioxidants. Reduced superoxide dismutase (SOD) activity and excess increased nitric oxide (NO) indicated aggravation of oxidative status after long-term dietary intake of Hg and PCBs. Neurobehavioral derangement in the central nervous system and significant delay in the Morris water maze test response on PND 91 are correlated with the increased of c-fos/c-jun expression levels in the cerebral cortex. These results suggest that MeHg neurotoxicity might be a greater hazard than that associated with PCB, but PCB may augment the neurobehavioral deficits caused by increased levels of mercury exposure. The simultaneous intake of selenium might have a protective effect on Hg accumulation in the body, and vitamin C might protect mice against the toxic effects of PCBs. However, the protective role of Se and vitamin C is very limited for multiple-agent pollution. Immediately early genes in the brain response to contaminated rice might be dependent on interaction among NO, NO synthase (NOS), SOD and reduced glutathione (GSH). We should be alert to mental health problems in human beings when any kind of Hg- and PCB-polluted food is

  3. Selenium, Chromium, and Vitamin D: What Dietitians Need to Know Regarding Dietary Supplements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate nutrient data for dietary supplement composition are essential for determining supplements’ contribution to total dietary intake. To plan a nationwide adult multivitamin/mineral (MVM) study, the USDA Nutrient Data Laboratory (NDL) obtained prevalence information for the most common labeled...

  4. Effect of dietary fat sources and zinc and selenium supplements on the composition and consumer acceptability of chicken meat.

    PubMed

    Bou, R; Guardiola, F; Barroeta, A C; Codony, R

    2005-07-01

    A factorial design was used to study the effect of changes in broiler feed on the composition and consumer acceptability of chicken meat. One week before slaughter, 1.25% dietary fish oil was removed from the feed and replaced by other fat sources (animal fat or linseed oil) or we continued with fish oil, and diets were supplemented with Zn (0, 300, or 600 mg/kg), and Se (0 or 1.2 mg/kg as sodium selenite or 0.2 mg/kg as Se-enriched yeast). The changes in dietary fat led to distinct fatty acid compositions of mixed raw dark and white chicken meat with skin. The fish oil diet produced meat with the highest eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) content, whereas the linseed oil diet led to meat with the highest content in total n-3 polyunsaturated acids (PUFA), especially linolenic acid. However, meat from animals on the animal fat diet was still rich in very long-chain n-3 PUFA. Se content was affected by Se and Zn supplements. Se content increased with Zn supplementation. However, only Se from the organic source led to a significant increase in this mineral in meat compared with the control. Consumer acceptability scores and TBA values of cooked dark chicken meat after 74 d or after 18 mo of frozen storage were not affected by any of the dietary factors studied. PMID:16050130

  5. Anti-tumor and immunomodulatory activity of selenium (Se)-polysaccharide from Se-enriched Grifola frondosa.

    PubMed

    Mao, Guang-Hua; Ren, Yi; Li, Qian; Wu, Hui-Yu; Jin, Dun; Zhao, Ting; Xu, Cai-Quan; Zhang, Deng-Hong; Jia, Qing-Dong; Bai, Yan-Peng; Yang, Liu-Qing; Wu, Xiang-Yang

    2016-01-01

    A polysaccharide termed Se-GP11 was extracted and purified from Se-enriched Grifola frondosa in our previous study. This study investigated the characterization, anti-tumor and immunomodulatory activity of Se-GP11. The results showed that Se-GP11 was composed of mannose, glucose and galactose with a molar ratio of 1:4.91:2.41. The weight-average molecular weight (Mw) and weight-average mean square radius (Rw) of Se-GP11 in 0.1M sodium chloride solution were 3.3×10(4)Da and 32.8 nm. Se-GP11 existed as a globular conformation with random coil structure. Se-GP11 had no anti-tumor activity against HepG-2 cells in vitro, and it significantly inhibited the growth of Heps tumor in vivo. Se-GP11 increased the relatively thymus and spleen weights as well as serum necrosis factor-alpha (TNF-α) and interleukin-2 (IL-2) levels. In addition, Se-GP11 promoted the phagocytosis and NO production of RAW264.7 as compared with that of the normal control group. The results revealed that the Se-GP11 may exhibit the anti-tumor through improving immunologic function of the tumor bearing mice. PMID:26522247

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

    PubMed

    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

  7. Selenium Bioavailability from Soybeans in Rats Fed a Modified Torula Yeast Diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is an essential nutrient, and soy is a major plant source of dietary protein to humans. The United States produces one third of world’s soybeans, and the Se-rich Northern Plains states produce a large share of the Nation’s soybeans. The present study examined the bioavailability of Se ...

  8. Selenium in bone health: roles in antioxidant protection and cell proliferation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is an essential trace element for humans and animals, and several findings suggest that dietary Se intake may be necessary for bone health. Such findings may relate to roles of Se in antioxidant protection, enhanced immune surveillance and modulation of cell proliferation. Elucidation ...

  9. Nano-sized Minerals of Elemental Selenium and Tellurium Formed by Bacterial Dissimilatory Reduction of Se- and Te-Oxyanions.

    NASA Astrophysics Data System (ADS)

    Oremland, R. S.

    2007-12-01

    Selenium and tellurium are both Group 16 elements that have curious opto-electrical properties making them of potential interest for photovoltaic applications. The process of dissimilatory reduction of selenate and selenite by 3 diverse species of anaerobes, Bacillus selenitireducens, Sulfurospirillum barnesii, and Selenihalanaerobacter shriftii resulted in the accumulation of many uniformly-sized nanospheres (diameter = approx. 300 nm) that aggregated on the outside of their cell envelopes (Oremland et al., 2004). Despite their uniformity of shape, purified Se-nanospheres from the 3 different species displayed significantly different spectral properties (UV- visible light and Raman) indicating differing internal arrangements of their Se atoms. Se-nanospheres from all 3 species also had lower bandgap energies than that of elemental selenium formed by chemical means. We subsequently determined that S. barnesii and B. selenitireducens could grow by dissimilatory reduction of Te- oxyanions, although progress was hampered by the fact that Te concentrations above 0.6 mM proved toxic to cells (Baesman et al., 2007). Unlike the case for Se-nanospheres, the Te-nanoparticles formed by the two microbes were entirely different. S. barnesii formed small, irregularly shaped spheroids (smaller than 50 nm diameter) that coalesced into larger aggregates. In contrast, B. selenitreducens formed nano-rods (10 nm diameter x 200 nm length) that coalesced into larger shards which formed even larger rosette-shaped aggregates once they sloughed off the cells. Spectroscopy of purified Te-rosettes indicated an internal trigonally-shaped array of Te atoms. Future research on Te(0) nano-materials formed by anaerobic bacteria would be aided by isolation of novel species adapted to growth at high batch culture concentrations of Te-oxyanions (approx. 10 mM). Furthermore, the ability of microbes like B. selenitreducens to form selenide by reduction of Se(0) suggests an application in the

  10. Formation of two-dimensional CuSe on Cu(111) at very low selenium coverage

    DOE PAGESBeta

    Walen, Holly; Liu, Da -Jiang; Oh, Junepyo; Yang, Hyun Jin; Kim, Yousoo; Thiel, Patricia A.

    2016-05-09

    Here, using scanning tunneling microscopy (STM), we observe that adsorption of Se on Cu(111) produces islands with (√3 x √3)R30° structure, at Se coverages far below the structure's ideal coverage of 1/3 ML. Based on density functional theory (DFT), these islands cannot form due to attractive interactions between chemisorbed Se atoms. DFT shows that incorporating Cu atoms into the √3-Se lattice stabilizes the structure, which provides a plausible explanation for the experimental observations.

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

    SciTech Connect

    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. Biomimetic Synthesis of Selenium Nanospheres by Bacterial Strain JS-11 and Its Role as a Biosensor for Nanotoxicity Assessment: A Novel Se-Bioassay

    PubMed Central

    Dwivedi, Sourabh; AlKhedhairy, Abdulaziz A.; Ahamed, Maqusood; Musarrat, Javed

    2013-01-01

    Selenium nanoparticles (Se-NPs) were synthesized by green technology using the bacterial isolate Pseudomonas aeruginosa strain JS-11. The bacteria exhibited significant tolerance to selenite (SeO32−) up to 100 mM concentration with an EC50 value of 140 mM. The spent medium (culture supernatant) contains the potential of reducing soluble and colorless SeO32− to insoluble red elemental selenium (Se0) at 37°C. Characterization of red Se° product by use of UV-Vis spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM) with energy dispersive X-ray spectrum (EDX) analysis revealed the presence of stable, predominantly monodispersed and spherical selenium nanoparticles (Se-NPs) of an average size of 21 nm. Most likely, the metabolite phenazine-1-carboxylic acid (PCA) released by strain JS-11 in culture supernatant along with the known redox agents like NADH and NADH dependent reductases are responsible for biomimetic reduction of SeO32− to Se° nanospheres. Based on the bioreduction of a colorless solution of SeO32− to elemental red Se0, a high throughput colorimetric bioassay (Se-Assay) was developed for parallel detection and quantification of nanoparticles (NPs) cytotoxicity in a 96 well format. Thus, it has been concluded that the reducing power of the culture supernatant of strain JS-11 could be effectively exploited for developing a simple and environmental friendly method of Se-NPs synthesis. The results elucidated that the red colored Se° nanospheres may serve as a biosensor for nanotoxicity assessment, contemplating the inhibition of SeO32− bioreduction process in NPs treated bacterial cell culture supernatant, as a toxicity end point. PMID:23483909

  13. Effects of organic and inorganic dietary selenium supplementation on gene expression profiles in oviduct tissue from broiler-breeder hens.

    PubMed

    Brennan, K M; Crowdus, C A; Cantor, A H; Pescatore, A J; Barger, J L; Horgan, K; Xiao, R; Power, R F; Dawson, K A

    2011-05-01

    Selenium (Se) is an essential component of at least 25 selenoproteins involved in a multitude of physiological functions, including reproduction. However, relatively little is known about the mechanisms by which Se exerts its physiological effects in reproductive tissue. The objective of this study was to compare the effect of long-term inorganic Se (sodium selenite, SS) and organic yeast-derived Se (Sel-Plex(®), SP) supplementations on tissue Se content and gene expression patterns in the oviduct of broiler-breeder hens. Hens were randomly assigned at 6 weeks of age to one of the three treatments: basal semi-purified diet (control), basal diet+0.3 ppm Se as SP or basal diet+0.3 ppm Se as SS. At 49 weeks, oviduct tissue from hens randomly selected from each treatment (n=7) was analyzed for Se content and gene expression profiles using the Affymetrix Chicken genome array. Gene expression data were evaluated using GeneSpring GX 10.0 (Silicon Genetics, Redwood, CA) and Ingenuity Pathways Analysis software (Ingenuity Systems, Redwood City, CA). Oviduct Se concentration was greater with Se supplementation compared with the control (P≤0.05) but did not differ between SS- and SP-supplemented groups. Gene expression analysis revealed that the quantity of gene transcripts associated with energy production and protein translation were greater in the oviduct with SP but not SS supplementation. Targets up-regulated by SP, but not SS, included genes encoding several subunits of the mitochondrial respiratory complexes, ubiquinone production and ribosomal subunits. SS hens showed a decrease in transcripts of genes involved in respiratory complexes, ATP synthesis and protein translation and metabolism in oviduct relative to control hens. In this study, although tissue Se concentrations did not differ between hens fed SS- and SP-supplemented diets, expression patterns of genes involved in energy production and protein synthesis pathways differed between treatments. These

  14. The evolution of the global selenium cycle: Secular trends in Se isotopes and abundances

    NASA Astrophysics Data System (ADS)

    Stüeken, E. E.; Buick, R.; Bekker, A.; Catling, D.; Foriel, J.; Guy, B. M.; Kah, L. C.; Machel, H. G.; Montañez, I. P.; Poulton, S. W.

    2015-08-01

    The Earth's surface has undergone major transitions in its redox state over the past three billion years, which have affected the mobility and distribution of many elements. Here we use Se isotopic and abundance measurements of marine and non-marine mudrocks to reconstruct the evolution of the biogeochemical Se cycle from ∼3.2 Gyr onwards. The six stable isotopes of Se are predominantly fractionated during redox reactions under suboxic conditions, which makes Se a potentially valuable new tool for identifying intermediate stages from an anoxic to a fully oxygenated world. δ82/78Se shows small fractionations of mostly less than 2‰ throughout Earth's history and all are mass-dependent within error. In the Archean, especially after 2.7 Gyr, we find an isotopic enrichment in marine (+0.37 ± 0.27‰) relative to non-marine samples (-0.28 ± 0.67‰), paired with increasing Se abundances. Student t-tests show that these trends are statistically significant. Although we cannot completely rule out the possibility of volcanic Se addition, these trends may indicate the onset of oxidative weathering on land, followed by non-quantitative reduction of Se oxyanions during fluvial transport. The Paleoproterozoic Great Oxidation Event (GOE) is not reflected in the marine δ82/78Se record. However, we find a major inflection in the secular δ82/78Se trend during the Neoproterozoic, from a Precambrian mean of +0.42 ± 0.45‰ to a Phanerozoic mean of -0.19 ± 0.59‰. This drop probably reflects the oxygenation of the deep ocean at this time, stabilizing Se oxyanions throughout the water column. Since then, reduction of Se oxyanions has likely been restricted to anoxic basins and diagenetic environments in sediments. In light of recent Cr isotope data, it is likely that oxidative weathering before the Neoproterozoic produced Se oxyanions in the intermediate redox state SeIV, whereas the fully oxidized species SeVI became more abundant after the Neoproterozoic rise of

  15. Dietary organic selenium improves growth, survival and resistance to Vibrio mimicus in cultured marron, Cherax cainii (Austin, 2002).

    PubMed

    Nugroho, Rudy Agung; Fotedar, Ravi

    2013-07-01

    To determine the effects of dietary organic selenium (OS) supplementation on the growth performance and immune competence of marron, Cherax cainii (Austin, 2002), a group of marron were fed 0.2 g kg(-1) of Sel-Plex(®) supplemented basal diet and then compared with another group (control) of marron fed basal diet without any supplementation. After 90 days of feeding, final weight, average weekly gains (AWG), relative gain rate (RGR), specific growth rate (SGR), survival, total and differential haemocyte counts (THC and DHC), were compared between the two groups. Surviving marron from each group were then divided into three sub-groups (three tanks per sub-group with seven marron per tank); (1) first sub-group was injected with 20 μL of 3.24 × 10(6) cfu Vibrio mimicus; (2) the second sub-group was injected with 20 μL normal saline and (3) the third sub-group was not subjected to injection and became the control group. THC, DHC, neutral red retention time (NRRT) and Vibrio ranks of post-injected marron were evaluated for 96 h, at every 24-h interval. The results showed that after 90 days of feeding, final weight, AWG, RGR, SGR, survival, THC, proportion of hyaline cells of OS-fed marron were significantly higher (P < 0.05) than the control group, whereas proportion of granular and semigranular cells were not affected by dietary OS. After challenging with V. mimicus, survival rate of marron without dietary OS significantly decreased (P < 0.05) as compared to the control group of marron. THC of marron in all sub-groups were significantly reduced (P < 0.05) after the challenge. However, THC and granular cells of sub-groups fed OS were higher than other sub-groups. Vibrio ranks and NRRT of marron fed OS were significantly lower and slower, respectively, than marron fed without OS. These findings demonstrated the benefits of OS inclusion in the marron diet in terms of growth, health and disease resistance. PMID:23603239

  16. Low temperature co-pyrolysis of hexabenzylditinsulfide and selenium. An alternate route to Sn(S{sub x}Se{sub 1{minus}x})

    SciTech Connect

    Boudjouk, P.; Remington, M.P. Jr.; Seidler, D.J.; Jarabek, B.R.; Grier, D.G.; Very, B.E.; Jarabek, R.L.; McCarthy, G.J.

    1999-12-01

    Benzyl-substituted tin chalcogenides (Bn{sub 3}Sn){sub 2}S (1) and (Bn{sub 3}Sn){sub 2}Se (2) yield polycrystalline-phase pure SnS and SnSe in good ceramic yields when pyrolyzed with S and Se, respectively, at 275 C. Heating mixtures of (1) and elemental selenium produce solid solutions of the formula Sn(S{sub x}Se{sub 1{minus}x}). Combustion analysis showed less than 1% residual carbon in all ceramic products. This methodology allows the complete conversion of tin-to-tin chalcogenides and eliminates the need to synthesize organosulfur and organoselenium intermediates.

  17. The electronic states of SeF: A reinterpretation of the chemiluminescent emission of the reaction of selenium with fluorine

    NASA Astrophysics Data System (ADS)

    Hermoso, Willian; Ornellas, Fernando R.

    2010-05-01

    The low-lying doublet and quartet electronic states of the species SeF correlating with the first dissociation channel are investigated theoretically at a high-level of electronic correlation treatment, namely, the complete active space self-consistent field/multireference single and double excitations configuration interaction (CASSCF/MRSDCI) using a quintuple-zeta quality basis set including a relativistic effective core potential for the selenium atom. Potential energy curves for (Λ +S) states and the corresponding spectroscopic properties are derived that allows for an unambiguous assignment of the only spectrum known experimentally as due to a spin-forbidden X Π2-a ∑4- transition, and not a A Π2-X Π2 transition as assumed so far. For the bound excited doublets, yet unknown experimentally, this study is the first theoretical characterization of their spectroscopic properties. Also the spin-orbit coupling constant function for the X Π2 state is derived as well as the spin-orbit coupling matrix element between the X Π2 and a ∑4- states. Dipole moment functions and vibrationally averaged dipole moments show SeF to be a very polar species. An overview of the lowest-lying spin-orbit (Ω ) states completes this description.

  18. Plasma and breastmilk selenium in HIV-infected Malawian mothers are positively associated with infant selenium status but are not associated with maternal supplementations: Breastfeeding, Antiretrovirals, and Nutrition Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Low dietary selenium (Se) intake coupled with low plasma Se concentrations in HIV infection could result in inadequate breastmilk Se intake by exclusively breastfed infants of HIV-infected women. Objective: To test the effect of lipid-based nutrient supplements (LNS) containing 1.3 R...

  19. Influence of high dietary lead on selenium metabolism in dairy calves

    SciTech Connect

    Neathery, M.W.; Miller, W.J.; Gentry, R.P.; Crowe, C.T.; Alfaro, E.; Fielding, A.S.; Pugh, D.G.; Blackmon, D.M.

    1987-03-01

    Metabolism of orally dosed /sup 75/Se was studied in 10 intact male Holstein calves that were fed ad libitum a control diet containing no added Pb or supplemented with 1000 ppm Pb as PbSO/sub 4/ for 4 wk. Lead-supplemented calves did not exhibit any clinical signs of Pb toxicity. Voluntary feed intake was reduced by 9.5% and average daily gain by 23%. Lead content of rib, liver, and kidney increased. Serum glutamic oxaloacetate transaminase activity was increased during the last 2 wk of the experiment in calves fed Pb. In calves receiving supplemental Pb, /sup 75/Se absorption, blood concentration, and urine concentration were reduced by 26, 21, and 42%, respectively. Tissue /sup 75/Se concentrations were significantly lower in kidney, liver, testicle, pancreas, small intestine, heart, spinal cord, and muscle in calves fed Pb. There was a significant negative correlation (r = -.78) between /sup 75/Se and stable Pb concentrations in the liver. It is not clear whether the ingestion of subclinical amounts of Pb could affect the absorption and utilization of Se in dairy calves to the extent of Se deficiency when dairy calves are kept in areas known to be low in Se.

  20. Elk (Cervus elaphus canadensis) preference for feeds varying in selenium concentration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium-accumulator plants are reputed to be unpalatable to large ungulates. Elk (Cervus elaphus canadensis) populations in south-eastern Idaho overlap with populations of Se-rich plants, but there is no information on the influence of plant Se concentration on elk dietary preferences. The objecti...

  1. Liquid-phase syntheses and material properties of two-dimensional nanocrystals of rare earth-selenium compound containing planar Se layers: RESe2 nanosheets and RE4O4Se3 nanoplates.

    PubMed

    Gu, Jun; Zhao, Ze-Qiong; Ding, Yi; Chen, Hong-Liang; Zhang, Ya-Wen; Yan, Chun-Hua

    2013-06-01

    Synthesis of diverse two-dimensional nanostructures with unique material properties is of current interest and multidisciplinary importance but remains a challenge for trivalent rare earth (RE)-selenium (Se) compounds because of the weak affinity between hard rare earth cations and soft selenium anions. In this article, for the first time, we report a mild solution approach toward a series of two-dimensional trivalent RE-selenium compound nanocrystals, namely RESe2 nanosheets (RE = La to Nd, for EuSe2, nanobars were obtained) and RE4O4Se3 nanoplates (RE = Nd, Sm, Gd to Ho), under a high chemical potential of selenium obtained by activating SeO2 powder with oleylamine in high boiling point organic solvents. Both kinds of nanocrystals contain Se with -1 valence in planar Se layers, allowing for a great variability in their crystal structures. Satellite diffraction peaks were observed in the electron diffraction pattern of LaSe2 nanosheets, indicating the presence of Peierls distortion in the Se layers. In the RE4O4Se3 nanoplates, the interaction between Se(2-) ions and [Se-Se](2-) dumbbells in the Se layers increases when the radii of the RE(3+) ions decrease along the lanthanide series, resulting in a narrower optical band gap (from 1.96 to 1.73 eV). The LaSe2 nanosheet films fabricated by drop-casting exhibited good electrical conductivity at room temperature (about 1 Ω·cm(-1)). Further, the RE4O4Se3 nanoplates showed very high light extinction capacity in the visible region (extinction coefficient μi: 4.4 × 10(5) cm(-1) for Nd4O4Se3, and 3.1 × 10(5) cm(-1) for Gd4O4Se3), comparable to that (5 × 10(5) cm(-1)) of CuInS2 commonly used in solar cells. PMID:23672182

  2. Delayed formation of zero-valent selenium nanoparticles by Bacillus mycoides SeITE01 as a consequence of selenite reduction under aerobic conditions

    PubMed Central

    2014-01-01

    Background Selenite (SeO32−) oxyanion shows severe toxicity to biota. Different bacterial strains exist that are capable of reducing SeO32− to non-toxic elemental selenium (Se0), with the formation of Se nanoparticles (SeNPs). These SeNPs might be exploited for technological applications due to their physico-chemical and biological characteristics. The present paper discusses the reduction of selenite to SeNPs by a strain of Bacillus sp., SeITE01, isolated from the rhizosphere of the Se-hyperaccumulator legume Astragalus bisulcatus. Results Use of 16S rRNA and GyrB gene sequence analysis positioned SeITE01 phylogenetically close to B. mycoides. On agarized medium, this strain showed rhizoid growth whilst, in liquid cultures, it was capable of reducing 0.5 and 2.0 mM SeO32− within 12 and 24 hours, respectively. The resultant Se0 aggregated to form nanoparticles and the amount of Se0 measured was equivalent to the amount of selenium originally added as selenite to the growth medium. A delay of more than 24 hours was observed between the depletion of SeO32 and the detection of SeNPs. Nearly spherical-shaped SeNPs were mostly found in the extracellular environment whilst rarely in the cytoplasmic compartment. Size of SeNPs ranged from 50 to 400 nm in diameter, with dimensions greatly influenced by the incubation times. Different SeITE01 protein fractions were assayed for SeO32− reductase capability, revealing that enzymatic activity was mainly associated with the membrane fraction. Reduction of SeO32− was also detected in the supernatant of bacterial cultures upon NADH addition. Conclusions The selenite reducing bacterial strain SeITE01 was attributed to the species Bacillus mycoides on the basis of phenotypic and molecular traits. Under aerobic conditions, the formation of SeNPs were observed both extracellularly or intracellullarly. Possible mechanisms of Se0 precipitation and SeNPs assembly are suggested. SeO32− is proposed to be enzimatically reduced to

  3. Treating chronic arsenic toxicity with high selenium lentil diets

    SciTech Connect

    Sah, Shweta; Vandenberg, Albert; Smits, Judit

    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

  4. Effects of selenium biofortification on crop nutritional quality

    PubMed Central

    Malagoli, Mario; Schiavon, Michela; dall’Acqua, Stefano; Pilon-Smits, Elizabeth A. H.

    2015-01-01

    Selenium (Se) at very low doses has crucial functions in humans and animals. Since plants represent the main dietary source of this element, Se-containing crops may be used as a means to deliver Se to consumers (biofortification). Several strategies have been exploited to increase plant Se content. Selenium assimilation in plants affects both sulfur (S) and nitrogen (N) metabolic pathways, which is why recent research has also focused on the effect of Se fertilization on the production of S- and N- secondary metabolites with putative health benefits. In this review we discuss the function of Se in plant and human nutrition and the progress in the genetic engineering of Se metabolism to increase the levels and bioavailability of this element in food crops. Particular attention is paid to Se biofortification and the synthesis of compounds with beneficial effects on health. PMID:25954299

  5. Selenium (Se) seed priming induced growth and biochemical changes in wheat under water deficit conditions.

    PubMed

    Nawaz, Fahim; Ashraf, M Yasin; Ahmad, Rashid; Waraich, Ejaz Ahmad

    2013-02-01

    Insufficient stand establishment at early growth stages in wheat (Triticum aestivum L.) due to drought stress is a major problem that limits overall efficiency and yield of crop. Priming of seed is an effective method for raising seed performance and improving tolerance of crops to abiotic stresses especially drought. The seeds of two local wheat cultivars (Kohistan-97 and Pasban-90) were soaked in distilled water or sodium selenate solutions of 25, 50, 75, and 100 μM for 1/2 or 1 h at 25 °C and later re-dried to their original moisture levels before sowing. One-hour priming significantly increased root length stress tolerance index, dry matter stress tolerance index, and total biomass of seedlings; however, no significant effect of changing duration of Se seed priming was observed on plant height stress tolerance index and shoot/root ratio. Among cultivars, Kohistan-97 was found to be more responsive to Se seed treatment as 1 h priming at 100 μM significantly increased its total biomass by 43 % as compared to control treatment. Although biomass of seedlings was not affected with Se seed priming under normal conditions, but it increased significantly with increase in rates of Se under drought stress conditions. One-hour priming at 75 μM increased the total sugar content and total free amino acids in both wheat cultivars. A more significant decrease in soluble proteins of seedlings was observed by 1 h priming than 1/2 h priming under drought stress conditions. PMID:23197374

  6. Radiative rates and electron impact excitation rate coefficients for Ne-like selenium, Se XXV

    SciTech Connect

    Wang, K.; Chen, C.Y. Huang, M.; Wang, Y.S.; Zou, Y.M.

    2011-07-15

    In this article we report calculations of energy levels, radiative rates, electron impact collision strengths, and effective collision strengths for transitions among the 241 fine-structure levels arising from 2l{sup 8} and 2l{sup 7}n{sup '}l{sup '} (n{sup '{<=}}6 and l{sup '{<=}}n{sup '}-1) configurations of Ne-like Se XXV using the Flexible Atomic Code. Energy levels and radiative rates are calculated within the relativistic configuration-interaction method. Direct excitation collision strengths are calculated using the relativistic distorted-wave approximation and high-energy collision strengths are obtained in the relativistic plane-wave approximation. Resonance contributions through the relevant Na-like doubly-excited configurations 2l{sup 7}n'l'n''l'' (3{<=}n'{<=}7, l'{<=}n'-1, n'{<=}n''{<=}50, and l''{<=}8) are explicitly taken into account via the independent-process and isolated-resonance approximation using distorted waves. Resonant stabilizing transitions and possibly important radiative decays from the resonances toward low-lying autoionizing levels are considered. In addition, the resonance contributions from Na-like 2l{sup 6}3l'3l'''n''' (n'''=3-6) configurations are included and found to be predominant for many transitions among the singly-excited states in Ne-like Se XXV. We present the radiative rates, oscillator strengths, and line strengths for all electric dipole, magnetic dipole, electric quadrupole, magnetic quadrupole, electric octopole, and magnetic octopole transitions among the 241 levels. The effective collision strengths are reported for all 28920 transitions among the 241 levels over a wide temperature range up to 10 keV. To assess the reliability and accuracy of the present collisional data, we have performed a 27-state close-coupling calculation, employing the Dirac R-matrix theory. The results from the close-coupling calculation and the independent-process calculation for the identical target states are found to be in good agreement

  7. Selenium-Containing Phycocyanin from Se-Enriched Spirulina platensis Reduces Inflammation in Dextran Sulfate Sodium-Induced Colitis by Inhibiting NF-κB Activation.

    PubMed

    Zhu, Chenghui; Ling, Qinjie; Cai, Zhihui; Wang, Yun; Zhang, Yibo; Hoffmann, Peter R; Zheng, Wenjie; Zhou, Tianhong; Huang, Zhi

    2016-06-22

    Selenium (Se) plays an important role in fine-tuning immune responses. Inflammatory bowel disease (IBD) involves hyperresponsive immunity of the digestive tract, and a low Se level might aggravate IBD progression; however, the beneficial effects of natural Se-enriched diets on IBD remain unknown. Previously, we developed high-yield Se-enriched Spirulina platensis (Se-SP) as an excellent organic nutritional Se source. Here we prepared Se-containing phycocyanin (Se-PC) from Se-SP and observed that Se-PC administration effectively reduced the extent of colitis in mouse induced by dextran sulfate sodium. Supplementation with Se-PC resulted in significant protective effects, including mitigation of body weight loss, bloody diarrhea, and colonic inflammatory damage. The anti-inflammatory effects of Se-PC supplementation were found to involve modulation of cytokines, including IL-6, TNF-α, MCP-1, and IL-10. Mechanistically, Se-PC inhibited the activation of macrophages by suppressing the nuclear translocation of NF-κB, which is involved in the transcription of these pro-inflammatory cytokines. These results together suggest potential benefits of Se-PC as a functional Se supplement to reduce the symptoms of IBD. PMID:27223481

  8. Influence of the forms and levels of dietary selenium on antioxidant status and oxidative stress-related parameters in rainbow trout (Oncorhynchus mykiss) fry.

    PubMed

    Fontagné-Dicharry, Stéphanie; Godin, Simon; Liu, Haokun; Antony Jesu Prabhu, Philip; Bouyssière, Brice; Bueno, Maïté; Tacon, Philippe; Médale, Françoise; Kaushik, Sadasivam J

    2015-06-28

    Se is an essential micronutrient required for normal growth, development and antioxidant defence. The objective of the present study was to assess the impact of dietary Se sources and levels on the antioxidant status of rainbow trout (Oncorhynchus mykiss) fry. First-feeding fry (initial body weight: 91 mg) were fed either a plant- or fishmeal-based diet containing 0·5 or 1·2 mg Se/kg diet supplemented or not with 0·3 mg Se/kg diet supplied as Se-enriched yeast or sodium selenite for 12 weeks at 17°C. Growth and survival of rainbow trout fry were not significantly affected by dietary Se sources and levels. Whole-body Se was raised by both Se sources and to a greater extent by Se-yeast. The reduced:oxidised glutathione ratio was raised by Se-yeast, whereas other lipid peroxidation markers were not affected by dietary Se. Whole-body Se-dependent glutathione peroxidase (GPX) activity was enhanced in fish fed Se-yeast compared to fish fed sodium selenite or non-supplemented diets. Activity and gene expression of this enzyme as well as gene expression of selenoprotein P (SelP) were reduced in fish fed the non-supplemented plant-based diet. Catalase, glutamate-cysteine ligase and nuclear factor-erythroid 2-related factor 2 (Nrf2) gene expressions were reduced by Se-yeast. These results suggest the necessity to supplement plant-based diets with Se for rainbow trout fry, and highlight the superiority of organic form of Se to fulfil the dietary Se requirement and sustain the antioxidant status of fish. GPX and SelP expression proved to be good markers of Se status in fish. PMID:25990817

  9. Developing selenium-enriched animal feed and biofuel from canola planted for managing Se-laden drainage waters in the westside of central California.

    PubMed

    Bañuelos, G S; Da Roche, J; Robinson, J

    2010-03-01

    We studied the reuse of selenium (Se)-laden effluent for producing canola (Brassica napus) and subsequent bioproducts in central California. Canola was irrigated with poor quality waters [electrical conductivity (EC) of approximately 5 dS m(-1) sulfate-salinity, 5 mg B L(-1), and 0.25 mg Se L(-1)]. Typical seed yields were 2.2 metric tons ha(-1). Seeds were processed for their oil, and transesterified to produce ASTM-quality biodiesel (BD) blends. The resulting Se-enriched seed cake meal (containing approximately 2 mg Se kg(-1) DM) was used in a dairy feed trial. Seventy-two Jersey and Holstein cows, 36 respectively, were fed Se-enriched canola meal as 6.2% of their daily feed ration for five weeks. Blood and milk samples were collected weekly and analyzed for total Se. This study showed that Se-enriched canola meal did not significantly increase total blood Se content in either cow breed. Milk Se concentrations did, however, significantly increase to safe levels of 59 microg Se L(-1) and 52 microg Se L(-1) in Jersey and Holstein cows, respectively. The production of BD 20 biofuels and Se-enriched feed meal from canola irrigated with poor quality waters may help sustain similar phytomanagement strategies under Se-rich conditions. PMID:20734619

  10. Dietary vitamin E (alpha-tocopherol acetate) and selenium supplementation from different sources: performance, ascites-related variables and antioxidant status in broilers reared at low and optimum temperatures.

    PubMed

    Ozkan, S; Malayoğlu, H Basmacioğlu; Yalçin, S; Karadas, F; Koçtürk, S; Cabuk, M; Oktay, G; Ozdemir, S; Ozdemir, E; Ergül, M

    2007-10-01

    1. This study compared the effect of dietary supplementation with organic or inorganic selenium (Se) sources plus control amounts or large amounts of vitamin E (alpha-tocopherol acetate) in broilers raised at control (20 to 24 degrees C) or low (14.5 to 16.8 degrees C) temperatures after 2 weeks of age. 2. The following dietary treatments were used from one day old. Diet 1, the control diet, comprised a commercial diet containing 0.15 mg/kg inorganic Se and 50 mg vitamin E/kg feed. Diet 2 was the same as diet 1, supplemented with 0.15 mg/kg inorganic Se. Diet 3 was the same as diet 2 but was supplemented with 200 mg/kg vitamin E. Diet 4 was the same as diet 1, but inorganic Se was replaced with 0.30 mg/kg organic Se. Diet 5 was the same as diet 4, supplemented with 200 mg/kg vitamin E. 3. Low temperature reduced the growth rate of broilers; however, at 6 weeks, there were no differences in the body weights of birds fed on organic Se supplemented diets housed at low or control temperature. The feed conversion ratio was significantly affected by low temperature but not by diet. The heterophil/lymphocyte ratio was higher in chicks after one week in the cold, indicating mild stress. Blood triiodothyronine levels were significantly higher in birds after 1 and 4 weeks in the cold but thyroxin was not affected. 4. Organic Se supplementation increased relative lung weight at the control temperature, which might lead to greater respiratory capacity. Relative spleen weight significantly decreased in broilers fed diets supplemented with inorganic Se under cold conditions, a possible indication of chronic oxidative stress. 5. At the low temperature, supplementation with organic Se alone, or with inorganic Se and vitamin E increased glutathione peroxidase (GSHPx) activity and glutathione (GSH) concentration in the liver of broilers, which may indicate increased activity of birds' antioxidant defence against suboptimal environments. PMID:17952730

  11. Selenium-72 formation via nat Br(p,x) induced by 100 MeV protons: steps towards a novel 72Se/72As generator system.

    PubMed

    Ballard, B; Wycoff, D; Birnbaum, E R; John, K D; Lenz, J W; Jurisson, S S; Cutler, C S; Nortier, F M; Taylor, W A; Fassbender, M E

    2012-04-01

    Selenium-72 production by the proton bombardment of a natural NaBr target has been successfully demonstrated at the Los Alamos National Laboratory Isotope Production Facility (LANL-IPF). Arsenic-72 (half life 26 h) is a medium-lived positron emitting radionuclide with the major advantage of being formed as the daughter of another "generator" radioisotope (Se-72, 8.5 d). A (72)Se/(72)As generator would be the preferred mechanism for clinical utilization of (72)As for positron emission tomography (PET). No portable (72)Se/(72)As generator system has been demonstrated for convenient, repeated (72)As elution ("milking"). In this work, we describe (72)Se production and recovery from irradiated NaBr targets using a 100 MeV proton beam. We also introduce an (72)As generator principle based on (72)Se chelation followed by liquid-liquid extraction, which will be transferred to a solid-phase sorption/elution system. PMID:22326368

  12. Relativistic effect on 77Se NMR chemical shifts of various selenium species in the framework of zeroth-order regular approximation.

    PubMed

    Nakanishi, Waro; Hayashi, Satoko; Katsura, Yoshifumi; Hada, Masahiko

    2011-08-11

    The relativistic effects on absolute magnetic shielding tensors (σ(Se)) are explicitly evaluated for various selenium species (40 species) with the DFT(BLYP)-GIAO method. Calculations are performed under relativistic and nonrelativistic conditions with the Slater-type basis sets in ADF 2010 in the framework of ZORA, employing the optimized structures under nonrelativistic conditions at B3LYP of Gaussian 03. Quadruple zeta all electron with four polarization functions (QZ4Pae) are mainly applied to evaluate σ(Se). Ranges of the effect on diamagnetic (σ(d)(Se)), paramagnetic shielding tensors (σ(p)(Se)), and σ(d+p)(Se) (= σ(d)(Se) + σ(p)(Se)) are -24 to -20 ppm, -115 to -3 ppm, and -136 to -26 ppm, respectively. The spin-orbit terms (σ(so)(Se)) are evaluated to be 92-225 ppm with QZ4Pae, which clarifies the effect on total shielding tensors (σ(t)(Se) = σ(d+p)(Se) + σ(so)(Se)) to be -8 to 152 ppm, at the spin-orbit ZORA level. The calculated σ(t)(Se) values reproduced well the observed values. PMID:21710994

  13. Chemical Forms of Mercury And Selenium in Fish Following Digestion With Simulated Gastric Fluid

    SciTech Connect

    George, G.N.; Singh, S.P.; Prince, R.C.; Pickering, I.J.

    2009-05-18

    Fish is a major dietary source of potentially neurotoxic methylmercury compounds for humans. It is also a rich source of essential selenium. We have used in situ mercury L{sub III}-edge and selenium K-edge X-ray absorption spectroscopy to chemically characterize the methylmercury and selenium in both fresh fish and fish digested with simulated gastric fluid. For the mercury, we confirm our earlier finding [Harris et al. (2003) Science301, 1203] that the methylmercury is coordinated by a single thiolate donor, which resembles cysteine, and for the selenium, we find a mixture of organic forms that resemble selenomethionine and an aliphatic selenenyl sulfide such as Cys-S-Se-Cys. We find that local chemical environments of mercury and selenium do not change upon digestion of the fish with simulated gastric fluid. We discuss the toxicological implications for humans consuming fish.

  14. Chicken meat nutritional value when feeding red palm oil, palm oil or rendered animal fat in combinations with linseed oil, rapeseed oil and two levels of selenium

    PubMed Central

    2013-01-01

    Chicken meat nutritional value with regard to fatty acid composition and selenium content depends on the choice of dietary oil and selenium level used in the chickens’ feed. The objective of this study was to investigate the effect of replacing commonly used rendered animal fat as a dietary source of saturated fatty acids and soybean oil as a source of unsaturated fatty acids, with palm oil and red palm oil in combinations with rapeseed oil, linseed oil and two levels of selenium enriched yeast on chicken breast meat nutritional value. The study also wished to see whether red palm oil had a cholesterol lowering effect on chicken plasma. 204 male, newly hatched broiler chickens were randomly divided into twelve dietary treatment groups, and individually fed one out of six dietary fat combinations combined with either low (0.1 mg Se /kg feed) or high (1 mg Se/kg feed) dietary selenium levels. Linseed oil, independent of accompanying dietary fat source, lead to increased levels of the n-3 EPA, DPA and DHA and reduced levels of the n-6 arachidonic acid (AA). The ratio between AA/EPA was reduced from 19/1 in the soybean oil dietary groups to 1.7/1 in the linseed oil dietary groups. Dietary red palm oil reduced total chicken plasma cholesterol levels. There were no differences between the dietary groups with regard to measured meat antioxidant capacity or sensory evaluation. Chicken meat selenium levels were clearly influenced by dietary selenium levels, but were not influenced by feed fatty acid composition. High dietary selenium level lead to marginally increased n-3 EPA and higher meat fat % in breast muscle but did not influence the other LC PUFA levels. Chicken breast meat nutritional value from the soybean oil and low selenium dietary groups may be regarded as less beneficial compared to the breast meat from the linseed oil and high selenium dietary groups. Replacing rendered animal fat with palm oil and red palm oil had no negative effects on chicken muscle

  15. Effects of gestational plane of nutrition and selenium supplementation on mammary development and colostrum quality in pregnant ewe lambs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To examine effects of nutritional plane and selenium (Se) supplementation on colostrum quality and mammary development, individually fed, pregnant Rambouillet ewe lambs were allotted randomly to 1 of 6 treatments in a 2 x 3 factorial arrangement. Main effects included dietary Se level which began at...

  16. Selenium Bioavailability from Soy Protein Isolate and Tofu in Rats Fed a Torula Yeast-Based Diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is an essential nutrient, and soy is a major plant source of dietary protein to humans. The United States produces one-third of world’s soybeans, and the Se-rich Northern Plains produce a large share of the nation’s soybeans. The present study used a rat model to determine the bioavail...

  17. Antagonistic Growth Effects of Mercury and Selenium in Caenorhabditis elegans Are Chemical-Species-Dependent and Do Not Depend on Internal Hg/Se Ratios.

    PubMed

    Wyatt, Lauren H; Diringer, Sarah E; Rogers, Laura A; Hsu-Kim, Heileen; Pan, William K; Meyer, Joel N

    2016-03-15

    The relationship between mercury (Hg) and selenium (Se) toxicity is complex, with coexposure reported to reduce, increase, and have no effect on toxicity. Different interactions may be related to chemical compound, but this has not been systematically examined. Our goal was to assess the interactive effects between the two elements on growth in the nematode Caenorhabditis elegans, focusing on inorganic and organic Hg (HgCl2 and MeHgCl) and Se (selenomethionine, sodium selenite, and sodium selenate) compounds. We utilized aqueous Hg/Se dosing molar ratios that were either above, below, or equal to 1 and measured the internal nematode total Hg and Se concentrations for the highest concentrations of each Se compound. Observed interactions were complicated, differed between Se and Hg compounds, and included greater-than-additive, additive, and less-than-additive growth impacts. Biologically significant interactions were only observed when the dosing Se solution concentration was 100-25 000 times greater than the dosing Hg concentration. Mitigation of growth impacts was not predictable on the basis of internal Hg/Se molar ratio; improved growth was observed at some internal Hg/Se molar ratios both above and below 1. These findings suggest that future assessments of the Hg and Se relationship should incorporate chemical compound into the evaluation. PMID:26938845

  18. Effect of alcohol consumption selenium bioavailability in rats

    SciTech Connect

    Cho, H.K.

    1986-01-01

    This study was done to determine the effects of alcohol consumption on selenium bioavailability in initially Se-depleted rats. Weanling male rats were fed a Se deficient basal diet for 4 weeks and then for the subsequent 4 weeks were supplemented at 0.031 mg Se/Kg or at 0.085 mg Se/Kg of diet in the form of high Se yeast. During the Se repletion period alcohol replaced medium chain triglycerides in the diet at three levels: 0%, 10% and 20% of calories. Dietary Se level significantly affected urinary Se, fecal Se, Se absorption, Se balance whole blood Se, whole blood glutathione peroxidase activity, liver Se concentration, and total liver Se content. Alcohol consumption significantly increased liver Se concentrations and total liver Se in rats fed the adequate Se diet. In rates fed the low Se diet, this pattern was not shown. There was a significant interaction between alcohol and Se level in terms of liver Se concentration and total liver Se. In the first week of Se repletion, fecal Se. Se absorption and Se balance were significantly higher in the 10% alcohol group fed the low Se repletion diet compared to rats given 0% and 20% alcohol in the same Se group. In the final week Se repletion the parameters of Se balance were not affected by alcohol consumption. Alcohol consumption did not influence whole blood Se and whole blood glutathione peroxidase activity; however alcohol consumption significantly reduced growth rate at both Se levels.

  19. Dynamic equilibrium of endogenous selenium nanoparticles in selenite-exposed cancer cells: a deep insight into the interaction between endogenous SeNPs and proteins.

    PubMed

    Bao, Peng; Chen, Song-Can; Xiao, Ke-Qing

    2015-12-01

    Elemental selenium (Se) was recently found to exist as endogenous nanoparticles (i.e., SeNPs) in selenite-exposed cancer cells. By sequestrating critical intracellular proteins, SeNPs appear capable of giving rise to multiple cytotoxicity mechanisms including inhibition of glycolysis, glycolysis-dependent mitochondrial dysfunction, microtubule depolymerization and inhibition of autophagy. In this work, we reveal a dynamic equilibrium of endogenous SeNP assembly and disassembly in selenite-exposed H157 cells. Endogenous SeNPs are observed both in the cytoplasm and in organelles. There is an increase in endogenous SeNPs between 24 h and 36 h, and a decrease between 36 h and 72 h according to transmission electron microscopy results and UV-Vis measurements. These observations imply that elemental Se in SeNPs could be oxidized back into selenite by scavenging superoxide radicals and ultimately re-reduced into selenide; then the assembly and disassembly of SeNPs proceed simultaneously with the sequestration and release of SeNP high-affinity proteins. There is also a possibility that the reduction of elemental Se to selenide pathway may lie in selenite-exposed cancer cells, which results in the assembly and disassembly of endogenous SeNPs. Genome-wide expression analysis results show that endogenous SeNPs significantly altered the expression of 504 genes, compared to the control. The endogenous SeNPs induced mitochondrial impairment and decreasing of the annexin A2 level can lead to inhibition of cancer cell invasion and migration. This dynamic flux of endogenous SeNPs amplifies their cytotoxic potential in cancer cells, thus provide a starting point to design more efficient intracellular self-assembling systems for overcoming multidrug resistance. PMID:26456389

  20. Selenium uptake by edible oyster mushrooms (Pleurotus sp.) from selenium-hyperaccumulated wheat straw.

    PubMed

    Bhatia, Poonam; Prakash, Ranjana; Prakash, N Tejo

    2013-01-01

    In an effort to produce selenium (Se)-fortifying edible mushrooms, five species of oyster mushroom (Pleurotus sp.), were cultivated on Se-rich wheat straw collected from a seleniferous belt of Punjab, India. Total selenium was analyzed in the selenium hyperaccumulated wheat straw and the fruiting bodies. Significantly high levels (p<0.0001) of Se uptake were observed in fruiting bodies of all mushrooms grown on Se-rich wheat straw. To the best of our knowledge, accumulation and quantification of selenium in mushrooms has hitherto not been reported with substrates naturally enriched with selenium. The results demonstrate the potential of selenium-rich agricultural residues as substrates for production of Se-enriched mushrooms and the ability of different species of oyster mushrooms to absorb and fortify selenium. The study envisages potential use of selenium-rich agricultural residues towards cultivation of Se-enriched mushrooms for application in selenium supplementation or neutraceutical preparations. PMID:23535542

  1. Selenium Sulfide

    MedlinePlus

    Selenium sulfide, an anti-infective agent, relieves itching and flaking of the scalp and removes the dry, ... Selenium sulfide comes in a lotion and is usually applied as a shampoo. As a shampoo, selenium ...

  2. Selenium isotope analysis

    SciTech Connect

    Webster, C.L. Jr.; Warren, C.G.

    1981-01-01

    The isotope ratio of selenium-80 to selenium-74 was determined on an isotope ratio mass spectrometer. Samples of 2 to 4 mg of selenium were fluorinated with CoF/sub 3/ in a small disposable copper bomb. The product, SeF/sub 6/, was purified in a vacuum line by distillation. The /sup 80/Se//sup 74/Se ratio was determined on a double-collector mass spectrometer that was modified to collect either /sup 82/Se-/sup 80/Se or /sup 80/Se-/sup 74/Se ion pairs. The standard deviation of the difference between two individually fluorinated samples was about 1 per mil. Because essentially all the error was associated with the fluorination step, comparisons between a standard of SeF/sub 6/ and individually fluorinated samples can be expected to have a standard deviation of about 0.5 per mil.

  3. COMPARING THE RECOMMENDED DIETARY ALLOWANCE TO TOXICITY VALUES FOR ZN, SE, MN, AND MB

    EPA Science Inventory

    Certain essential nutrients can be toxic when ingested at dosages higher than the daily nutritional requirement. Research data for the essential trace elements, zinc, selenium, manganese and molybdenum have been reviewed by various government agencies for both their nutritional n...

  4. Characterization of selenium-enriched mycelia of Catathelasma ventricosum and their antihyperglycemic and antioxidant properties.

    PubMed

    Liu, Yuntao; Li, Caiming; Luo, Xiaohu; Han, Guoquan; Xu, Shude; Niu, Fuge; Hu, Xinjie; Wu, Hejun; Zhang, Huimin

    2015-01-21

    This is the first report concerning the selenium enrichment of Catathelasma ventricosum mycelia. The selenium-containing proteins present in selenium-enriched mycelia (Se-MC) were identified using size-exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS). The selenium-containing amino acids liberated by hydrolysis of these proteins were identified using anion exchange-ICP-MS. Se-MC was found to contain selenoproteins with molecular weights ranging from 1.7 to 60.5 kDa. The main selenium-containing amino acids within them were selenomethionine and selenocysteine. Furthermore, Se-MC possessed excellent antihyperglycemic and antioxidant properties. Se-MC normalized biochemical parameters like insulin level, blood glucose level, body weight, and antioxidant enzyme activity in streptozocin-induced diabetic mice. It also inhibited the α-amylase and α-glucosidase activities present in in vitro gastric and intestinal models. In conclusion, Se-MC has the potential to serve as a dietary supplement of selenium, an antioxidant, or an ingredient for the formulation of nutraceuticals. PMID:25536291

  5. Effects of Dietary Selenium Against Lead Toxicity on mRNA Levels of 25 Selenoprotein Genes in the Cartilage Tissue of Broiler Chicken.

    PubMed

    Gao, H; Liu, C P; Song, S Q; Fu, J

    2016-07-01

    The interactions between the essential element selenium (Se) and the toxic element lead (Pb) have been reported extensively; however, little is known about the effect of Se on Pb toxicity and the expression pattern of selenoproteins in the cartilage of chicken. To investigate the effects of Se on Pb toxicity and the messenger RNA (mRNA) expressions of selenoproteins in cartilage tissue, an in vitro study was performed on 1-day-old broiler chickens (randomly allocated into four groups) with diet of different concentration of Se and Pb. After 90 days, the meniscus cartilage and sword cartilage tissue were examined for the mRNA levels of 25 selenoprotein genes. The results showed that Se and Pb influenced the expression of selenoprotein genes in the chicken cartilage tissue. In detail, Se could alleviate the downtrend of the expression of Gpx1, Gpx2, Gpx4, Txnrd2, Txnrd3, Dio1, Dio2, Seli, Selu, Sepx1, Selk, Selw, Selo, Selm, Sep15, Sepnn1, Sels, and Selt induced by Pb exposure in the meniscus cartilage. In the sword cartilage, Se alleviated the downtrend of the expression of Gpx2, Gpx3, Gpx4, Txnrd1, Txnrd2, Dio2, Dio3, Seli, Selh, SPS2, Sepx1, Selk, Selw, Selo, Selm, Sep15, Selpb, Sepn1, and Selt induced by Pb exposure. The present study provided some compensated data about the roles of Se against Pb toxicity in the regulation of selenoprotein expression. PMID:26643179

  6. Selenium biomineralization for biotechnological applications.

    PubMed

    Nancharaiah, Yarlagadda V; Lens, Piet N L

    2015-06-01

    Selenium (Se) is not only a strategic element in high-tech electronics and an essential trace element in living organisms, but also a potential toxin with low threshold concentrations. Environmental biotechnological applications using bacterial biomineralization have the potential not only to remove selenium from contaminated waters, but also to sequester it in a reusable form. Selenium biomineralization has been observed in phylogenetically diverse microorganisms isolated from pristine and contaminated environments, yet it is one of the most poorly understood biogeochemical processes. Microbial respiration of selenium is unique because the microbial cells are presented with both soluble (SeO(4)(2-) and SeO(3)(2-)) and insoluble (Se(0)) forms of selenium as terminal electron acceptor. Here, we highlight selenium biomineralization and the potential biotechnological uses for it in bioremediation and wastewater treatment. PMID:25908504

  7. Thyroid Hormones and Cortisol Concentrations in Offspring are Influenced by Maternal Supranutritional Selenium and Nutritional Plane in Sheep

    PubMed Central

    Vonnahme, Kimberly A.; Neville, Tammi L.; Lekatz, Leslie A.; Reynolds, Lawrence P.; Hammer, Carolyn J.; Redmer, Dale A.; Caton, Joel S.

    2013-01-01

    To determine the effects of maternal supranutritional selenium (Se) supplementation and maternal nutritional plane on offspring growth potential, ewes were randomly assigned to 1 of 6 treatments in a 2 × 3 factorial arrangement [dietary Se (adequate Se; 9.5 μg/kg body weight vs. high Se; 81.8 μg/kg body weight initiated at breeding) and plane of nutrition [60%, 100%, or 140% of requirements; initiated on day 50 of gestation

  8. A global survey of effects of genotype and environment on selenium concentration in lentils (Lens culinaris L.): Implications for nutritional fortification strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lentils (Lens culinaris L.) are an important protein and carbohydrate food, rich in essential dietary components and trace elements. Selenium (Se) is an essential micronutrient for human health. For adults, 55 µg of daily Se intake is recommended for better health and cancer prevention. Millions of ...

  9. Effects of selenium supply and dietary restriction on maternal and fetal body weight, visceral organ mass, cellularity estimates, and jejeunal vascularity in pregnant ewe lambs.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To examine effects of nutrient restriction and dietary Se on maternal and fetal visceral tissues, 36 pregnant Targhee-cross ewe lambs were allotted randomly to one of four treatments in a 2 x 2 factorial design. Factors were nutrition [control nutrition (CON, 100% of requirements) vs. restricted nu...

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

    PubMed

    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

  11. Selenium and Tellurium concentrations of ultradepleted peridotites determined by isotope dilution ICPMS: implications for Se-Te systematics of the Earth's mantle

    NASA Astrophysics Data System (ADS)

    König, S.; Luguet, A.; Lorand, J.-P.; Wombacher, F.; Lissner, M.

    2012-04-01

    As for highly siderophile elements, selenium and tellurium may constitute key tracers for planetary processes such as formation of the Earth's core and the Late Veneer composition, provided that their geochemical behaviour and abundances in the primitive upper mantle (PUM) are constrained. Within this scope, we have developed a high precision analytical method for the simultaneous determination of selenium and tellurium concentrations from a single sample aliquot and various rock matrices, including ultradepleted peridotites. The technique employs isotope dilution, thiol cotton fiber (TCF) separation and hydride generation MC-ICP-MS. A selection of international mafic and ultramafic rock reference materials BIR-1, BE-N, TDB-1, UB-N, FON B 93, BIR-1 and BHVO-2 with a range of 30 to 350 ppb Se and 0.7 to 12 ppb Te show external reproducibilities of 3 to 8% for Se and 0.4 to 11% for Te (2 relative standard deviations (r.s.d.)). We have applied this method to a suite of refractory mantle peridotites (Al2O3 <1.5 wt. %) from Lherz, previously shown to be strongly and uniformly depleted in Se, Te and incompatible elements by high degree of partial melting (20 ± 5%). In contrast to fertile lherzolites which remain at broadly chondritic values (Se/Te = 9), the ultradepleted harzburgites show highly fractionated and up to suprachondritic Se/Te (< 35) that correlate with decreasing Te concentrations. The fractionation is displayed by the depleted peridotites as well as multiple analysis of a single Lherz harzburgite sample (64-3). This shows 1) a strong sample heterogeneity effect for Te and 2) a more incompatible behaviour of Te compared to Se on the whole rock scale, once base metal sulfides are highly depleted and in some cases entirely consumed by partial melting. The marked differences in Se-Te systematics observed between fertile lherzolites and depleted harzburgites can be explained by the combined effect of i) different abundances and proportions of residual and

  12. Blood glutathione peroxidase-1 mRNA levels can be used as molecular biomarkers to determine dietary selenium requirements in rats.

    PubMed

    Sunde, Roger A; Thompson, Kevin M; Evenson, Jacqueline K; Thompson, Britta M

    2009-11-01

    Transcript (mRNA) levels are increasingly being used in medicine as molecular biomarkers for disease and disease risk, including use of whole blood as a target tissue for analysis. Development of blood molecular biomarkers for nutritional status, too, has potential application that parallels opportunities in medicine, including providing solid data for individualized nutrition. We previously reported that blood glutathione peroxidase-1 (Gpx1) mRNA was expressed at levels comparable to major tissues in rats and humans. To determine the efficacy of using blood Gpx1 mRNA to assess selenium (Se) status and requirements, we fed graded levels of Se (0-0.3 microg Se/g as selenite) to weanling male rats. Se status was determined by liver Se concentration and selenoenzyme activity, and selenoprotein mRNA abundance in liver and blood was determined by ribonuclease protection analysis. Liver Se and plasma glutathione peroxidase-3 and liver Gpx1 activities indicated that minimal Se requirements were at 0.08 microg Se/g diet. When total RNA was isolated from whole blood, Gpx1 mRNA in Se-deficient rats decreased to 10% of levels in Se-adequate (0.2 microg Se/g diet) rats. With Se supplementation, blood Gpx1 mRNA levels increased sigmoidally to a plateau with a minimum Se requirement of 0.08 microg Se/g diet, whereas glutathione peroxidase-4 mRNA levels were unaffected. Similarly, Gpx1 mRNA in RNA isolated from fractionated red blood cells decreased in Se-deficient rats to 23% of Se-adequate levels, with a minimum Se requirement of 0.09 microg Se/g diet. Additional studies showed that the preponderance of whole blood Gpx1 mRNA arises from erythroid cells, most likely reticulocytes and young erythrocytes. In summary, whole blood selenoprotein mRNA levels can be used as molecular biomarkers for assessing Se requirements, illustrating that whole blood has potential as a target tissue in development of molecular biomarkers for use in nutrition as well as in medicine. PMID:19855070

  13. Percutaneous absorption of selenium sulfide

    SciTech Connect

    Farley, J.; Skelly, E.M.; Weber, C.B.

    1986-01-01

    The purpose of this study was to determine selenium levels in the urine of Tinea patients before and after overnight application of a 2.5% selenium sulfide lotion. Selenium was measured by atomic absorption spectroscopy (AAS). Hydride generation and carbon rod atomization were studied. It was concluded from this study that selenium is absorbed through intact skin. Selenium is then excreted, at least partially, in urine, for at least a week following treatment. The data show that absorption and excretion of selenium vary on an individual basis. Selenium levels in urine following a single application of selenium sulfide lotion do not indicate that toxic amounts of selenium are being absorbed. Repeated treatments with SeS/sub 2/ result in selenium concentrations in urine which are significantly higher than normal. Significant matrix effects are observed in the carbon rod atomization of urine samples for selenium determinations, even in the presence of a matrix modifier such as nickel. The method of standard additions is required to obtain accurate results in the direct determination of selenium in urine by carbon rod AAS.

  14. Selenium accumulation in lettuce germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is an essential micronutrient for animals and humans. Increasing Se content in food crops offers an effective approach to reduce the widespread selenium deficiency problem in many parts of the world. In this study, we evaluated thirty diverse accessions of lettuce (Lactuca sativa L.) f...

  15. Effects of feeding selenium deficient diets to rhesus monkeys (Macaca Mulatta)

    SciTech Connect

    Butler, J.A.; Whanger, P.D.; Patton, N.M.

    1988-02-01

    Pregnant rhesus monkeys (Macaca mulatta) were fed either selenium (Se) deficient or Se supplemented diets with adequate vitamin E. Except for some cardiac irregularities in the first babies born to these females, no physiological disorders due to Se deficiency were seen in a subsequent offspring. Plasma and erythrocyte glutathione peroxidase activities and blood Se levels increased in the Se supplemented monkeys but decreased in the deficient ones. The data indicated that hair Se levels reflect long term exposure to this element. In a very preliminary experiment, evidence was obtained to indicate that dietary protein deficiency along with Se deficiency will generate cardiomyopathic lesions characteristic of Se deficiency. It is hypothesized that, in addition to Se deficiency, another dietary deficiency (or abnormality) is necessary to produce Se deficiency lesions in higher primates. Higher glutathione transferase (or non-Se glutathione peroxidase) activity in tissues of rhesus monkeys may account for this resistance.

  16. Biomarkers of selenium status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The essential trace element selenium (Se) has multiple biological activities, which depend on the level of Se intake. Relatively low Se intakes determine the expression of selenoenzymes in which it serves as an essential constituent. Higher intakes have been shown to have anti-tumorigenic potentia...

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

    PubMed

    Gaxiola-Robles, Ramón; Labrada-Martagón, Vanessa; Celis de la Rosa, Alfredo de Jesús; Acosta-Vargas, Baudilio; Méndez-Rodríguez, Lía Celina; Zenteno-Savín, Tania

    2014-01-01

    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. PMID:25208800

  18. Influence of dietary methionine on the metabolism of selenomethionine in rats

    SciTech Connect

    Butler, J.A.; Beilstein, M.A.; Whanger, P.D. )

    1989-07-01

    To determine the influence of methionine on selenomethionine (SeMet) metabolism, weanling male rats were fed for 8 wk a basal diet marginally deficient in sulfur amino acids, containing 2.0 micrograms selenium (Se)/g as DL-SeMet and supplemented with 0, 0.3, 0.6 or 1.2% DL-methionine. Increased dietary methionine caused decreased selenium deposition in all tissues examined but increased glutathione peroxidase activity in testes, liver and lungs. A positive correlation was found between dietary methionine and the calculated percentage of selenium associated with GSHPx. In a second experiment, {sup 75}SeMet was injected into weanling male rats which had been fed the basal diet containing 2.0 micrograms selenium as DL-SeMet with or without the addition of 1.0% methionine. The selenoamino acid content of tissues and the distribution of {sup 75}Se in erythrocyte proteins were determined. In comparison to the rats fed the basal diet without added methionine, significantly more {sup 75}Se-selenocysteine was found in liver and muscle, more {sup 75}Se was found in erythrocyte GSHPx and less {sup 75}Se was found in erythrocyte hemoglobin of rats fed 1.0% methionine. These data suggest that methionine diverts SeMet from incorporation into general proteins and enhances its conversion to selenocysteine for specific selenium-requiring proteins, such as GSHPx.

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

    PubMed

    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

  20. Glutathione peroxidase activity and chemical forms of selenium in tissues of rats given selenite or selenomethionine

    SciTech Connect

    Beilstein, M.A.; Whanger, P.D.

    1988-05-01

    Glutathione peroxidase (GPx) activity and deposition of selenium (Se) were examined in tissues of rats given dietary Se for 7 wk as either selenite or selenomethionine (SeMet) with 75Se radiotracer of the same chemical form. On the basis of Se:75Se ratio, all tissues of the rats fed selenite were equilibrated with the dietary source, but tissues of the SeMet fed animals maintained a ratio of Se:75Se greater than the dietary ratio. Deposition of dietary Se and 75Se was higher in most tissues of rats fed SeMet. Muscle 75Se was the largest single tissue pool of 75Se in both groups accounting for one-third of recovered 75Se in the rats fed selenite, and one-half of recovered 75Se in the rats fed SeMet. Tissue GPx activities were not different between the two dietary groups. The proportion of Se as GPx in tissues was highest in erythrocytes of the rats fed selenite (.81) and lowest in testes and epididymides of the rats fed SeMet (.009). The proportion of Se present in cytosolic GPx was consistently higher in tissues of rats fed selenite. Erythrocytes of the rats fed SeMet had more 75Se associated with hemoglobin, and muscle cytosols of the rats fed selenite had more 75Se associated with the G-protein. The proportion of 75Se as SeMet determined by ion exchange chromatography of tissue hydrolysates was higher in tissues of rats fed SeMet (highest in muscle and hemoglobin, 70%, and lowest in testes, 16%). In contrast, selenocysteine was the predominant form of Se present in tissues of rats given selenite. These results indicate that the form of Se administered will influence the form in the tissues, the percentage of Se with GPx and the body burden of Se.

  1. Selenium-assisted controlled growth of graphene-Bi2Se3 nanoplates hybrid Dirac materials by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Sun, Zhencui; Man, Baoyuan; Yang, Cheng; Liu, Mei; Jiang, Shouzhen; Zhang, Chao; Zhang, Jiaxin; Liu, Fuyan; Xu, Yuanyuan

    2016-03-01

    Se seed layers were used to synthesize the high-quality graphene-Bi2Se3 nanoplates hybrid Dirac materials via chemical vapor deposition (CVD) method. The morphology, crystallization and structural properties of the hybrid Dirac materials were characterized by SEM, EDS, Raman, XRD, AFM and HRTEM. The measurement results verify that the Se seed layer on the graphene surface can effectively saturate the surface dangling bonds of the graphene, which not only impel the uniform Bi2Se3 nanoplates growing along the horizontal direction but also can supply enough Se atoms to fill the Se vacancies. We also demonstrate the Se seed layer can effectively avoid the interaction of Bi2Se3 and the graphene. Further experiments testify the different Se seed layer on the graphene surface can be used to control the density of the Bi2Se3 nanoplates.

  2. Why Nature Chose Selenium.

    PubMed

    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

  3. Mercury and selenium in tissues and stomach contents of the migratory sailfish, Istiophorus platypterus, from the Eastern Pacific: Concentration, biomagnification, and dietary intake.

    PubMed

    Bergés-Tiznado, Magdalena E; Fernando Márquez-Farías, J; Torres-Rojas, Yassir; Galván-Magaña, Felipe; Páez-Osuna, Federico

    2015-12-15

    Mercury and selenium were assessed in the sailfish, Istiophorus platypterus, from the Eastern Pacific. Sixty-seven individuals were sampled, muscle, liver, kidney, gonads and the prey found in the stomach contents were isolated during fishing 2011-2013 tournaments. Hg exhibited the following pattern (μg g(-1) wet weight): liver (0.57 ± 0.07)>muscle (0.56 ± 0.04)>kidney (0.44 ± 0.08)>gonad (0.14 ± 0.01). The maximum concentration of Se was found in kidneys (14.1 ± 1.9 μg g(-1)), and the minimum in muscles (0.67 ± 0.03 μg g(-1)). High Se:Hg ratios were found for muscle (4.1 ± 0.3), kidney (132.4 ± 12.1), liver (54.0 ± 4.4) and gonads (88.2 ± 7.9); Hg:Se molar ratios were several orders of magnitude lower (muscle<0.4 and liver, kidney and gonad<0.03). Sailfish feed mainly on fishes and cephalopods with low Hg levels (<0.13 μg g(-1)), these results indicate biomagnification of Hg and Se. The muscle of I. platypterus should be consumed (according the provisional tolerable weekly intake) by people cautiously so as not to exceed the recommended intake of 215 g per week. PMID:26490411

  4. Levels of the Antioxidant Nutrients Vitamin C, Vitamin E, and Selenium in the Dietary Supplement Ingredient Database: NHANES Data Applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory evidence indicates that antioxidants may slow or possibly prevent the development of certain cancers by protecting cells from damage caused by free radicals or other mechanisms. Many dietary supplements containing antioxidant constituents (e.g., vitamin C) are available to consumers. Th...

  5. Changing selenium nutritional status of Chinese residents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    China has been designated as one of 40 countries deficient in selenium (Se) according to the World Health Organization. Selenium concentrations in hair are commonly used to evaluate the Se level of the human body. Moreover, hair Se concentrations are significantly correlated with Se concentrations ...

  6. Bioavailability, toxicity and biotransformation of selenium in midge (Chironomus dilutus) larvae exposed via water or diet to elemental selenium particles, selenite, or selenized algae.

    PubMed

    Gallego-Gallegos, Mercedes; Doig, Lorne E; Tse, Justin J; Pickering, Ingrid J; Liber, Karsten

    2013-01-01

    Elemental selenium (Se) is generally considered to be biologically inert due to its insolubility in water. It is a common form of Se in sediment near uranium mining and milling operations in northern Saskatchewan, Canada. Nanosized particles of many materials exhibit different properties compared with their bulk phases, in some cases posing health and ecological risks. Here we investigated the bioavailability and toxicity of Se nanoparticles (SeNPs) using 10-day waterborne and dietary exposures to larvae of Chironomus dilutus, a common benthic invertebrate. For comparison, larvae were also exposed to waterborne dissolved selenite and to dietary selenomethionine as selenized algae. Larval Se accumulation was evaluated using graphite furnace atomic absorption spectroscopy or inductively coupled plasma mass spectroscopy for total Se and X-ray absorption spectroscopy for Se chemical speciation. Exposure to nanoparticulate Se resulted in Se bioaccumulation, at high concentrations, inhibiting larval growth in both waterborne and dietary exposures; larvae predominantly accumulated selenomethionine-like species regardless of uptake route or form of Se tested. Despite the observed Se accumulation, our findings suggest there is little risk of direct SeNP toxicity to benthic invertebrates in Se-contaminated sediments in northern Saskatchewan. Nevertheless, elemental Se in sediments may be biologically available and may contribute directly or indirectly to the risk of Se toxicity to egg-laying vertebrates (fish and piscivorous birds) in Se-contaminated aquatic systems. It thus may be necessary to include elemental Se as a source of potential Se exposure in ecological risk assessments. PMID:23234498

  7. Cotyledonary responses to maternal selenium and dietary restriction may influence alteration in fetal weight and fetal liver glycogen sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To examine the effects of maternal supranutritional Se and nutrient restriction during mid and late gestation on placental characteristics and fetal liver glycogen, ewes received either adequate Se (ASe) or high Se (HSe) prior to breeding. On day 64 of gestation, ASe and HSe ewes remained at 100% of...

  8. Distribution and speciation of selenium in the black shale of the Dogger aquifer in the Poitiers Experimental Hydrogeological Site

    NASA Astrophysics Data System (ADS)

    Bassil, Joseph; Naveau, Aude; Di Tullo, Pamela; Grasset, Laurent; Bodin, Jacques; Razack, Moumtaz; Kazpard, Véronique

    2014-05-01

    Selenium (Se) is an element having the narrowest range between dietary deficiency and toxic concentrations. In the environment, selenium has four oxidation states (-II, 0, IV and VI) and has a complex biogeochemical cycle. The European and French legislations fixed 10 µg/L as safe upper limit in drinking water. In several French regions2, selenium concentrations above the limit were detected in groundwater. This poses a problem for local authorities which are obliged to stop the exploitation of many wells. In the north flank of the "Seuil du Poitou", Selenium concentrations above 10 ppb were measured in groundwater samples collected from five wells of the Poitiers Experimental Hydrogeological Site (SEH), which investigates a 100 m carbonate aquifer (Dogger). Total rock analysis applied on samples representing all the geological facies observed in the SEH show that selenium is concentrated in the black clays that fulfill some karst cavities; these clays are thought considered as the main selenium source in the Dogger Aquifer. The main objective of this work is to study the distribution and the speciation of selenium in the geological matrix and the release mechanisms of Se in order to provide quantifiable data to numerical modeling of selenium's reactive flows across the aquifer. The distribution and the speciation of selenium in these black clays were studied by applying parallel and sequential chemical extractions and by verifying the impact of these extractions on the solid dissolution and organic matter mobilization. In all the extractions, the total dissolved selenium was quantified using ICP-MS and the selenium speciation in the aqueous phase by HPLC-ICP-MS. Verifying the impact of the extractions on the solid dissolution and on the organic matter mobilization was performed by measuring Al, Si, Fe and Ca by AAS and the Total Organic Carbon TOC and by acquisition of XRD diffractograms of the solid residues. Our results showed that most of the selenium is

  9. Influence of selenium, age and dosage of 7,12-dimethylbenz(a)anthracene (DMBA) on the in vivo formation of DNA adducts in mammary tissue

    SciTech Connect

    Jinzhou Liu; Milner, J.A. )

    1991-03-15

    Diets formulated to contain selenium, as sodium selenite, 0.1 or 2 {mu}g/g were fed for 2 weeks prior to DMBA treatment. Food intake and weight gain were not influenced by Se intake. Anti- and syn-dihydrodiol epoxide adducts reached maximum binding by 24 h. Se supplementation inhibited by about 50% the appearance of both anti-and syn- DMBA-DNA adducts. Dietary selenium increased the rate of removal of the anti-dihydrodiol epoxide adduct bound to guanine, but delayed the removal of the other adducts. The occurrence of DMBA-DNA adducts correlated positively with the dosage of DMBA administered. Binding increased about 40% as the rat's age increased from 36 to 125 d. Se supplementation inhibited binding in 36, 54 and 125 d old rats. These data confirmed that dietary selenium is effective in inhibiting in vivo metabolism of DMBA.

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

    PubMed

    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

  11. Selenium distribution in the epitaxial layers of PbTe/sub 1-z/Se/sub z/ solid solutions

    SciTech Connect

    Yakimchuk, D.Yu.; Tsveibak, I.Ya.; Sokolov, I.A.; Krapukhin, V.V.

    1987-03-01

    The authors have studied the Se distribution over the thickness of epitaxial layers of PbTe/sub 1-z/Se/sub z/ solid solutions that were obtained on PbTe (100) substrates by the method of forced cooling of solutions in melts in lead in the range 540-490/sup 0/C. The Se concentration has been found to have a considerable gradient. Theoretical analysis has shown that the Se distribution coefficient exceeds the values that are known from the literature and the molar fraction of PbSe in the liquid phase at the onset of the growth of the epitaxial layer is lower than the initial value; this indicates that the substrate dissolves when it comes into contact with the solution in a melt.

  12. Selenium and mercury in pelagic fish in the central north pacific near Hawaii.

    PubMed

    Kaneko, J John; Ralston, Nicholas V C

    2007-12-01

    Protective effects of selenium against mercury toxicity have been demonstrated in all animal models evaluated. As interactions between selenium and mercury and their molar ratios in seafood are essential factors in evaluating risks associated with dietary mercury exposure, considering mercury content alone is inadequate. In this study, the absolute and molar concentrations of mercury and selenium were determined in edible portions from 420 individual fish representing 15 species of pelagic fish collected from the central North Pacific Ocean near Hawaii. Selenium was in molar excess of mercury in almost all fish species evaluated. The rank order of mean Se/Hg molar ratios was striped marlin (17.6) > yellowfin tuna (14.1) > mahimahi (13.1) > skipjack tuna (12.8) > spearfish (11.4) > wahoo (10.8) > sickle pomfret (6.7) > albacore tuna (5.3) > bigeye tuna (5.2) > blue marlin (4.1) > escolar (2.4) > opah (2.3) > thresher shark (1.5) > swordfish (1.2) > mako shark (0.5). With a Se/Hg molar ratio of less than 1, mako shark was the only fish containing a net molar excess of mercury. A selenium health benefit value based on the absolute amounts and relative proportions of selenium and mercury in seafood is proposed as a more comprehensive seafood safety criterion. PMID:17916947

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

    SciTech Connect

    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.

  14. PbSe films by ion exchange of synthetic plumbonacrite layers immersed in a selenium ionic solution

    NASA Astrophysics Data System (ADS)

    Mendívil-Reynoso, T.; Ochoa-Landín, R.; Ramírez-Rodríguez, L. P.; Gutierrez-Acosta, K.; Ramírez-Bon, R.; Castillo, S. J.

    2016-06-01

    Plumbonacrite is a lead compound with chemical formula Pb10(CO3)6(OH)6O, where several groups can be substituted by ion exchange in mild conditions. Plumbonacrite layers can be deposited by means of the chemical bath deposition technique. In this work it is studied the structural and morphological evolution of a plumbonacrite layer as a function of the immersion time in an aqueous solution containing Se-2 ions. The 1.39 μm thick plumbonacrite layer was chemically deposited on a glass substrate and immersed in an aqueous solution with Se-2 ions for 10, 20, 30 and 50 min. The as grown plumbonacrite layer as well as the immersed ones were analyzed by X-rays Diffraction, Scanning Electron Microscopy and Raman Spectroscopy measurements. The results show that the plumbonacrite layer is gradually converted to PbSe one by ion exchange process, where Se-2 ions substitute the groups of plumbonacrite.

  15. Effects of dietary selenium on tissue concentrations, pathology, oxidative stress, and immune function in common eiders (Somateria mollissima)

    USGS Publications Warehouse

    Franson, J.C.; Hoffman, D.J.; Wells-Berlin, A.; Perry, M.C.; Shearn-Bochsler, V.; Finley, D.L.; Flint, P.L.; Hollmen, T.

    2007-01-01

    Common eiders (Somateria mollissima) were fed added Se (as L-selenomethionine) in concentrations increasing from 10 to 80 ppm in a pilot study (Study 1) or 20 (low exposure) and up to 60 (high exposure) ppm Se in Study 2. Body weights of Study 1 ducks and high-exposure ducks in Study 2 declined rapidly. Mean concentrations of Se in blood reached 32.4 ppm wet weight in Study 1 and 17.5 ppm wet weight in high-exposure birds in Study 2. Mean Se concentrations in liver ranged from 351 (low exposure, Study 2) to 1252 ppm dry weight (Study 1). Oxidative stress was evidenced by Se-associated effects on glutathione metabolism. As Se concentrations in liver increased, Se-dependent glutathione peroxidase activity, glutathione reductase activity, oxidized glutathione levels, and the ratio of hepatic oxidized to reduced glutathione increased. In Study 2, the T-cell-mediated immune response was adversely affected in high-exposure eiders, but ducks in the low-exposure group exhibited evidence of an enhanced antibody-mediated immune response. Gross lesions in high-exposure ducks included emaciation, absence of thymus, and loss of nails from digits. Histologic lesions included severe depletion of lymphoid organs, hepatopathy, and necrosis of feather pulp and feather epithelium. Field studies showed that apparently healthy sea ducks generally have higher levels of Se in liver than healthy fresh-water birds, but lower than concentrations found in our study. Data indicate that common eiders and probably other sea ducks possess a higher threshold, or adverse effect level, for Se in tissues than fresh-water species. However, common eiders developed signs of Se toxicity similar to those seen in fresh-water birds.

  16. Effects of dietary selenium on tissue concentrations,pathology, oxidative stress, and immune function in common eiders (Somateria mollissima)

    USGS Publications Warehouse

    Franson, J. Christian; Hoffman, David; Wells-Berlin, Alicia M.; Perry, Matthew C.; Shearn-Bochsler, Valerie I.; Finley, Daniel L.; Flint, Paul L.; Hollmén, Tuula E.

    2007-01-01

    Common eiders (Somateria mollissima) were fed added Se (as L-selenomethionine) in concentrations increasing from 10 to 80 ppm in a pilot study (Study 1) or 20 (low exposure) and up to 60 (high exposure) ppm Se in Study 2. Body weights of Study 1 ducks and high-exposure ducks in Study 2 declined rapidly. Mean concentrations of Se in blood reached 32.4 ppm wet weight in Study 1 and 17.5 ppm wet weight in high-exposure birds in Study 2. Mean Se concentrations in liver ranged from 351 (low exposure, Study 2) to 1252 ppm dry weight (Study 1). Oxidative stress was evidenced by Se-associated effects on glutathione metabolism. As Se concentrations in liver increased, Se-dependent glutathione peroxidase activity, glutathione reductase activity, oxidized glutathione levels, and the ratio of hepatic oxidized to reduced glutathione increased. In Study 2, the T-cell-mediated immune response was adversely affected in high-exposure eiders, but ducks in the low-exposure group exhibited evidence of an enhanced antibody-mediated immune response. Gross lesions in high-exposure ducks included emaciation, absence of thymus, and loss of nails from digits. Histologic lesions included severe depletion of lymphoid organs, hepatopathy, and necrosis of feather pulp and feather epithelium. Field studies showed that apparently healthy sea ducks generally have higher levels of Se in liver than healthy fresh-water birds, but lower than concentrations found in our study. Data indicate that common eiders and probably other sea ducks possess a higher threshold, or adverse effect level, for Se in tissues than fresh-water species. However, common eiders developed signs of Se toxicity similar to those seen in fresh-water birds.

  17. Effects of dietary selenium on tissue concentrations, pathology, oxidative stress, and immune function in common eiders (Somateria mollissima).

    PubMed

    Franson, J Christian; Hoffman, David J; Wells-Berlin, Alicia; Perry, Matthew C; Shearn-Bochsler, Valerie; Finley, Daniel L; Flint, Paul L; Hollmén, Tuula

    2007-05-15

    Common eiders (Somateria mollissima) were fed added Se (as L-selenomethionine) in concentrations increasing from 10 to 80 ppm in a pilot study (Study 1) or 20 (low exposure) and up to 60 (high exposure) ppm Se in Study 2. Body weights of Study 1 ducks and high-exposure ducks in Study 2 declined rapidly. Mean concentrations of Se in blood reached 32.4 ppm wet weight in Study 1 and 17.5 ppm wet weight in high-exposure birds in Study 2. Mean Se concentrations in liver ranged from 351 (low exposure, Study 2) to 1252 ppm dry weight (Study 1). Oxidative stress was evidenced by Se-associated effects on glutathione metabolism. As Se concentrations in liver increased, Se-dependent glutathione peroxidase activity, glutathione reductase activity, oxidized glutathione levels, and the ratio of hepatic oxidized to reduced glutathione increased. In Study 2, the T-cell-mediated immune response was adversely affected in high-exposure eiders, but ducks in the low-exposure group exhibited evidence of an enhanced antibody-mediated immune response. Gross lesions in high-exposure ducks included emaciation, absence of thymus, and loss of nails from digits. Histologic lesions included severe depletion of lymphoid organs, hepatopathy, and necrosis of feather pulp and feather epithelium. Field studies showed that apparently healthy sea ducks generally have higher levels of Se in liver than healthy fresh-water birds, but lower than concentrations found in our study. Data indicate that common eiders and probably other sea ducks possess a higher threshold, or adverse effect level, for Se in tissues than fresh-water species. However, common eiders developed signs of Se toxicity similar to those seen in fresh-water birds. PMID:17454562

  18. Supplementation with Selenium and Coenzyme Q10 Reduces Cardiovascular Mortality in Elderly with Low Selenium Status. A Secondary Analysis of a Randomised Clinical Trial

    PubMed Central

    Alexander, Jan; Aaseth, Jan

    2016-01-01

    Background Selenium is needed by all living cells in order to ensure the optimal function of several enzyme systems. However, the selenium content in the soil in Europe is generally low. Previous reports indicate that a dietary supplement of selenium could reduce cardiovascular disease but mainly in populations in low selenium areas. The objective of this secondary analysis of a previous randomised double-blind placebo-controlled trial from our group was to determine whether the effects on cardiovascular mortality of supplementation with a fixed dose of selenium and coenzyme Q10 combined during a four-year intervention were dependent on the basal level of selenium. Methods In 668 healthy elderly individuals from a municipality in Sweden, serum selenium concentration was measured. Of these, 219 individuals received daily supplementation with selenium (200 μg Se as selenized yeast) and coenzyme Q10 (200 mg) combined for four years. The remaining participants (n = 449) received either placebo (n = 222) or no treatment (n = 227). All cardiovascular mortality was registered. No participant was lost during a median follow-up of 5.2 years. Based on death certificates and autopsy results, all mortality was registered. Findings The mean serum selenium concentration among participants at baseline was low, 67.1 μg/L. Based on the distribution of selenium concentration at baseline, the supplemented group was divided into three groups; <65 μg/L, 65–85 μg/L, and >85 μg/L (45 and 90 percentiles) and the remaining participants were distributed accordingly. Among the non-treated participants, lower cardiovascular mortality was found in the high selenium group as compared with the low selenium group (13.0% vs. 24.1%; P = 0.04). In the group with the lowest selenium basal concentration, those receiving placebo or no supplementation had a mortality of 24.1%, while mortality was 12.1% in the group receiving the active substance, which was an absolute risk reduction of 12%. In

  19. Use of stable isotopic selenium as a tracer to follow incorporation of selenium into selenoproteins

    SciTech Connect

    Finley, J.W.; Vanderpool, R.A.; Korynta, E.

    1995-12-01

    Stable isotopes of selenium (Se) have been used in human studies to measure Se absorption, retention and excretion. The purpose of this study was to examine whether stable Se could also be used to follow the incorporation of Se into selenoproteins and whether selenoproteins are labeled with stable isotopes the same way they are with radioactive Se. Rats fed either a Se-deficient or a high-Se diet were injected with either a radioactive ({sup 75}Se) or a stable isotope of Se ({sup 77}Se), and the liver cytosol was chromatographed on Sephadex G-200. Compared with {sup 75}Se, a greater percentage of {sup 77}Se was incorporated into cytosol, but the distribution and the effect of dietary Se was similar for both isotopes. New Zealand long-eared rabbits were also injected with either {sup 77}Se or {sup 75}Se, and the plasma was chromatographed. More of the {sup 75}Se was incorporated into the plasma, but again the patterns of incorporation were similar for both isotopes. Plasma from a male subject who ingested 60 {mu}g of {sup 77}Se was chromatographed, and the stable Se was detected in column fractions and showed a distribution similar to that observed for rabbit plasma. Finally, a polyacrylamide gel electrophoresis (PAGE) method was developed that allowed loading of sufficient protein to analyze for {sup 77}Se in individual protein fractions. The distribution of {sup 77}Se and {sup 75}Se in rabbit plasma was similar. Human plasma was electrophoresed by a similar method and peaks of 56 and 23 kDa were detected. These data show that stable isotopes of Se can be used for selenoprotein production in the same way as radioactive isotopes. They also show that, when physiological amounts of stable Se are ingested by humans, the isotope can be detected in blood-borne proteins separated by column chromatography and PAGE. 28 refs., 5 figs.

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

    PubMed Central

    Gudmundsdottir, Edda Y.; Gunnarsdottir, Ingibjorg; Thorlacius, Arngrimur; Reykdal, Olafur; Gunnlaugsdottir, Helga; Thorsdottir, Inga; Steingrimsdottir, Laufey

    2012-01-01

    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. PMID:22952457

  1. Selenium (Se) deficiency alters intestinal diaphorase activity in mice infected with the intestinal parasitic worm Heligmosomoides polygyrus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mice fed a diet deficient in Se show reduced resistance to a secondary infection with H. polygyrus. IL-4 and IL-13-dependent- increases in intestinal smooth muscle hyper-contractility and decreased glucose absorption correlate with expulsion of the adult worm following a challenge infection. Selen...

  2. Toxicity of selenium (Na sub 2 SeO sub 3 ) and mercury (HgCl sub 2 ) on the planarian Dugesia gonocephala

    SciTech Connect

    Congiu, A.M.; Casu, S.; Ugazio, G. )

    1989-10-01

    The toxicity of selenium (Na{sub 2}SeO{sub 3}) and mercury (HgCl{sub 2}) was determined by using a freshwater planarian which is particularly sensitive to pollution, and belongs to a fissiparous breed of Dugesia gonocephala. The mortality and fissiparity frequency of the subjects were studied. They were exposed to intense treatments (48 hours) or for medium to long periods of time (21 days) to either the single compounds or a combination of both, and were fed or fasting. The lethal effect of sodium selenite is correlated to the food intake, whereas the toxicity of mercurous chloride is probably the result of a fixative effect which does not depend on feeding. The 21-day treatment with the first compound has a non-negligible lethal effect which is probably due to an accumulation phenomenon. At doses where an antioxidant effect prevails, fissiparity is stimulated. On the other hand, the second compound reduces reproduction frequency to half the base values. Compared to the Paracentrotus lividus, the Dugesia gonocephala offers various advantages concerning toxicological experiments; besides being easier to handle in the laboratory, it is available all year round and is not subject to seasonal cycles. It is also more susceptible to the toxic effect of mercury, which is a common and highly toxic pollutant, than the sea urchin.

  3. Platelet Indices of Selenium Status in Healthy and Selenium-Deficient Sheep: a Comparison with Selenium Indices in Plasma, Whole Blood, and Red Blood Cells.

    PubMed

    Dalir-Naghadeh, Bahram; Bahrami, Yaser; Rezaei, Siamak Asri; Anassori, Ehsan; Janalipour, Ali; Khosravi, Voria

    2015-11-01

    Several biomarkers have been used to evaluate selenium (Se) status in livestock. However, there is no report on the potential usefulness of the Se indices of platelets in diagnosis of Se deficiency in large animals. In the current study, Se concentration and glutathione peroxidase (GPx) activity in platelets of 38 healthy and 142 Se-deficient ewes were assessed, and their correlation with plasma Se concentration, plasma GPx activity, whole blood Se concentration, and erythrocyte GPx activity was determined. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff values of Se concentration and GPx activity of the platelets and to summarize the diagnostic performance of these biomarkers. In Se-deficient ewes, consistent with other indices, Se concentration and GPx activity in platelets were significantly lower than those of the healthy ewes. There was a positive significant correlation between Se concentration and GPx activity in platelets with plasma Se concentration, whole blood Se concentration, and erythrocyte GPx activity. Based on the ROC curve analysis, the best cutoff value to predict inadequate plasma selenium concentration was ≤0.0055 attogram/platelet for the platelet Se concentration, with a sensitivity of 100.0 %, specificity of 92.4 %, and AUC of 0.94. For platelet GPx activity, the cutoff value was ≤203.6 U/g protein with a sensitivity of 97.4 %, specificity of 77.7 %, and AUC of 0.90. The results of this study suggested that the platelet Se concentration and GPx activity can be considered a reliable and valid intermediate-term surrogate parameter in assessment of dietary Se intake in sheep. PMID:25900578

  4. Bioaccumulation of organic and inorganic selenium in a laboratory food chain

    SciTech Connect

    Besser, J.M.; Canfield, T.J.; La Point, T.W. )

    1993-01-01

    Aquatic organisms accumulated selenium (Se) from inorganic and organic Se species via aqueous and food-chain exposure routes. The authors measured aqueous and food-chain Se bioaccumulation from selenate, selenite, and seleno-L-methionine in a laboratory food chain of algae (Chlamydomonas reinhardtii), daphnids (Daphnia magna), and fish (bluegill, Lepomis macrochirus). Selenium concentrations were monitored radiometrically with [sup 75]Se-labeled compounds. All three organisms concentrated Se more strongly from aqueous selenomethionine than from either inorganic Se species. Bioconcentration factors estimated from 1 [mu]g Se/L Se-methionine exposures were approximately 16,000 for algae, 200,000 for daphnids, and 5,000 for bluegills. Algae and daphnids concentrated Se more strongly from selenite than selenate whereas bluegills concentrated Se about equally from both inorganic species. Bioaccumulation of foodborne Se by daphnids and bluegills was similar in food chains dosed with different Se species. Daphnids and bluegills did not accumulate Se concentrations greater than those in their diet, except at very low dietary Se concentrations. Food-chain concentration factors (CFs) for daphnids decreased from near 1.0 to 0.5 with increases in algal Se concentrations, whereas CFs estimated from bluegill exposures averaged 0.5 over a range of foodborne Se concentrations. In exposures based on selenite, bluegills accumulated greater Se concentrations from food than from water.

  5. Tolerance of the preruminant calf for selenium in milk replacer

    SciTech Connect

    Jenkins, K.J.; Hidiroglou, M.

    1986-07-01

    Calves were fed skim milk powder-based milk replacer containing either .2, 1, 3, 5, or 10 ppm selenium (added as sodium selenate) in the dry matter from 3 to 45 d of age to estimate the lowest amount of dietary selenium that would reduce calf performance and feed utilization. Only at the highest selenium (10 ppm) did calves show reduced average daily gain and feed efficiency and lower blood packed cell volume. Apparent digestibility of dry matter, nitrogen, and lipid, and plasma creatine phosphokinase activity were not affected by any of the selenium intakes. In general, selenium in blood, bile, duodenal mucosa, liver, kidney, and muscle reflected selenium intakes with liver and kidney reaching the highest selenium concentrations. Postmortem examinations of calves revealed no gross abnormalities for any of the selenium treatments. The preruminant calf is very tolerant of high inorganic selenium concentrations in skim milk powder-based milk replacer.

  6. Selenium. Nutritional, toxicologic, and clinical aspects.

    PubMed Central

    Fan, A. M.; Kizer, K. W.

    1990-01-01

    Despite the recent findings of environmental contamination, selenium toxicosis in humans is exceedingly rare in the United States, with the few known cases resulting from industrial accidents and an episode involving the ingestion of superpotent selenium supplements. Chronic selenosis is essentially unheard of in this country because of the typical diversity of the American diet. Nonetheless, because of the growing public interest in selenium as a dietary supplement and the occurrence of environmental selenium contamination, medical practitioners should be familiar with the nutritional, toxicologic, and clinical aspects of this trace element. PMID:2219873

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We determined the bioavailability of selenium (Se) from yellow peas and oats harvested from high-Se soil of South Dakota, United States. The Se concentrations of the peas and oats were 13.5 ± 0.2 and 2.5 ± 0.1 mg/kg, respectively. Male weanling Sprague-Dawley rats were depleted of Se by feeding them...

  8. Dietary exposure and trends of exposure to nutrient elements iodine, iron, selenium and sodium from the 2003-4 New Zealand Total Diet Survey.

    PubMed

    Thomson, Barbara M; Vannoort, Richard W; Haslemore, Roger M

    2008-03-01

    The mean dietary exposure to the nutrient elements iodine, Fe, Se and Na by eight age-sex groups of the New Zealand population was estimated from foods purchased and prepared as for consumption. A total of 968 samples comprising 121 foods were collected and analysed. Mean daily exposures were calculated from mean concentration levels of the selected nutrients in each food combined with simulated diets for a 25+-year-old male and female, a 19-24-year-old male, a 11-14-year-old boy and girl, a 5-6-year-old child, a 1-3-year-old toddler and a 6-12-month-old infant. Food concentrations and dietary exposures are reported and compared with nutrient reference values (for example, recommended daily intakes, adequate intakes or upper limits). Dietary iodine exposures for all age-sex groups were well below recommended levels and have steadily decreased since 1982, raising concern especially for the physical and mental development of infants and young children. Fe exposures meet the recommended daily intake for the average male and 11-14 year olds but are only about half that recommended for adult females. Se exposure is about 20 % less than optimal for females. Na exposures, excluding discretionary salt, are above the acceptable exposure level for all age-sex groups, and exceed the upper intake limits for 25+-year-old males, 19-24-year-old young males, and 11-14-year-old boys and girls by up to 125 % for an average consumer. PMID:17925056

  9. Thioacetamide-induced cirrhosis in selenium-adequate mice displays rapid and persistent abnormity of hepatic selenoenzymes which are mute to selenium supplementation

    SciTech Connect

    Zhang Jinsong Wang Huali; Yu Hanqing

    2007-10-01

    Selenium reduction in cirrhosis is frequently reported. The known beneficial effect of selenium supplementation on cirrhosis is probably obtained from nutritionally selenium-deficient subjects. Whether selenium supplementation truly improves cirrhosis in general needs additional experimental investigation. Thioacetamide was used to induce cirrhosis in selenium-adequate and -deficient mice. Selenoenzyme activity and selenium content were measured and the influence of selenium supplementation was evaluated. In Se-adequate mice, thioacetamide-mediated rapid onset of hepatic oxidative stress resulted in an increase in thioredoxin reductase activity and a decrease in both glutathione peroxidase activity and selenium content. The inverse activity of selenoenzymes (i.e. TrxR activity goes up and GPx activity goes down) was persistent and mute to selenium supplementation during the progress of cirrhosis; accordingly, cirrhosis was not improved by selenium supplementation in any period. On the other hand, selenium supplementation to selenium-deficient mice always more efficiently increased hepatic glutathione peroxidase activity and selenium content compared with those treated with thioacetamide, indicating that thioacetamide impairs the liver bioavailability of selenium. Although thioacetamide profoundly affects hepatic selenium status in selenium-adequate mice, selenium supplementation does not modify the changes. Selenium supplementation to cirrhotic subjects with a background of nutritional selenium deficiency can improve selenium status but cannot restore hepatic glutathione peroxidase and selenium to normal levels.

  10. Selenium bioavailability with reference to human nutrition

    SciTech Connect

    Young, V.R.; Nahapetian, A.; Janghorbani, M.

    1982-05-01

    Various aspects of selenium metabolism and nutrition in relation to the question of selenium bioavailability in foods and the diet of man are reviewed. Few published studies exist on selenium metabolism in human subjects, particularly those representative of healthy individuals in the United States. Animal studies reveal that various factors, including the source and chemical form of selenium in foods and feeds, influence selenium bioavailability. However, the quantitative significance of animal assay data for human nutrition is not known. The limited number of published studies in man suggest that the metabolic fate and physiological function of dietary selenite may differ from that of selenomethionine or of food selenium. However, much additional research will be required to establish an adequate picture of the significance of dietary selenium bioavailability in human nutrition and health. Based on initial human experiments carried out at the Massachusetts Institute of Technology, use of stable isotopes of selenium offers promising opportunities for closing the gap of knowledge that now exists concerning the role and significance of factors that determine how the selenium present in foods is used to meet the physiological requirements of the consumer.