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Sample records for disrupts selenium metabolism

  1. Arsenic and selenium in microbial metabolism

    Science.gov (United States)

    Stolz, John F.; Basu, Partha; Santini, Joanne M.; Oremland, Ronald S.

    2006-01-01

    Arsenic and selenium are readily metabolized by prokaryotes, participating in a full range of metabolic functions including assimilation, methylation, detoxification, and anaerobic respiration. Arsenic speciation and mobility is affected by microbes through oxidation/reduction reactions as part of resistance and respiratory processes. A robust arsenic cycle has been demonstrated in diverse environments. Respiratory arsenate reductases, arsenic methyltransferases, and new components in arsenic resistance have been recently described. The requirement for selenium stems primarily from its incorporation into selenocysteine and its function in selenoenzymes. Selenium oxyanions can serve as an electron acceptor in anaerobic respiration, forming distinct nanoparticles of elemental selenium that may be enriched in (76)Se. The biogenesis of selenoproteins has been elucidated, and selenium methyltransferases and a respiratory selenate reductase have also been described. This review highlights recent advances in ecology, biochemistry, and molecular biology and provides a prelude to the impact of genomics studies.

  2. Selenium accumulation and metabolism in algae.

    Science.gov (United States)

    Schiavon, Michela; Ertani, Andrea; Parrasia, Sofia; Vecchia, Francesca Dalla

    2017-08-01

    Selenium (Se) is an intriguing element because it is metabolically required by a variety of organisms, but it may induce toxicity at high doses. Algae primarily absorb selenium in the form of selenate or selenite using mechanisms similar to those reported in plants. However, while Se is needed by several species of microalgae, the essentiality of this element for plants has not been established yet. The study of Se uptake and accumulation strategies in micro- and macro-algae is of pivotal importance, as they represent potential vectors for Se movement in aquatic environments and Se at high levels may affect their growth causing a reduction in primary production. Some microalgae exhibit the capacity of efficiently converting Se to less harmful volatile compounds as a strategy to cope with Se toxicity. Therefore, they play a crucial role in Se-cycling through the ecosystem. On the other side, micro- or macro-algae enriched in Se may be used in Se biofortification programs aimed to improve Se content in human diet via supplementation of valuable food. Indeed, some organic forms of selenium (selenomethionine and methylselenocysteine) are known to act as anticarcinogenic compounds and exert a broad spectrum of beneficial effects in humans and other mammals. Here, we want to give an overview of the developments in the current understanding of Se uptake, accumulation and metabolism in algae, discussing potential ecotoxicological implications and nutritional aspects. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Selenium intake and metabolic syndrome: A systematic review.

    Science.gov (United States)

    Retondario, Anabelle; Fernandes, Ricardo; Rockenbach, Gabriele; Alves, Mariane de Almeida; Bricarello, Liliana Paula; Trindade, Erasmo Benicio Santos de Moraes; Vasconcelos, Francisco de Assis Guedes de

    2018-03-02

    Metabolic syndrome is a multi-causal disease. Its treatment includes lifestyle changes with a focus on weight loss. This systematic review assessed the association between Selenium intake and metabolic syndrome. Data were collected mainly from four databases: PubMed, CENTRAL (Cochrane), Scopus and Web of Knowledge. Keywords related to metabolic syndrome, selenium, as well as metabolic syndrome features were searched. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. A systematic review protocol was registered at PROSPERO (n. 42016046321). Two reviewers independently screened 2957 abstracts. Six studies were included to perform data extraction with standardized spreadsheets. The risk of bias was assessed by using specific tools according to the design of the relevant studies. An assessment was carried out based on the appropriateness of the study reports accordingly to STROBE and the CONSORT-based checklist for each study design. Three studies found no association between Selenium intake and metabolic syndrome; two of them found an inverse association; and one study found a direct association between Selenium intake and metabolic syndrome. One study also showed an inverse association between Selenium intake and the prevalence of high waist circumference, high diastolic blood pressure, and hyperglycaemia in women. Overall, based on the argumentation and results of this study, it is possible to conclude that Selenium intake and metabolic syndrome are not clearly associated in adults and elderly. Copyright © 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  4. Metabolism of manganese, iron, copper, and selenium in calves

    International Nuclear Information System (INIS)

    Ho, S.Y.

    1981-01-01

    Sixteen male Holstein calves were used to study manganese and iron metabolism. The calves were fed one of the following diets for 18 days: control, control + iron, control + manganese, and control + iron and manganese. All calves were dosed orally with manganese-54. Tissue concentrations of manganese, iron and manganese-54 were determined. Small intestinal iron was lower in calves fed the high manganese diet than in controls. Tissue manganese-54 was lower in calves fed a high manganese diet. Fecal manganese content increased in calves fed both high manganese and high manganese-high iron diets. Serum total iron was not affected by the dietary treatments. To study the effects of high dietary levels of copper and selenium on the intracellular distributions of these two elements in liver and kidney cytosol, calves were fed one of four diets for 15 days. These were 0 and 100 ppM supplemental copper and 0 and 1 ppM added selenium. The control diet containing 0.1 ppM of selenium and 15 ppM of copper. All calves were orally dosed 48 hrs prior to sacrifice with selenium-75. A high copper diet increased copper concentrations in all intracellular liver fractions and most kidney fractions. Only the effects in the liver were significant. Less copper was found in the mitochondria fractions in liver and kidney of calves fed a high selenium diet. Three major copper-binding protein peaks were separated from the soluble fractions of calf liver and kidney. Peak 1 appeared to be the major copper-binding protein in liver and kidney cytosol of copper-loaded animals. Added selenium alone or in combination with copper accentuated the copper accumulation in this peak. Most of selenium-75 was recovered in the same peak as the copper. The results of this experiment indicated that the large molecular proteins in liver and kidney cytosol of calves play an important role in copper and selenium-75 metabolism

  5. Selenium

    Science.gov (United States)

    ... Health Information Supplement Fact Sheets Frequently Asked Questions Making Decisions What you Need To Know About Supplements Dietary ... understand how selenium in food and dietary supplements affects heart health. Cognitive decline Blood selenium levels decrease as people age, ...

  6. Selenium

    Science.gov (United States)

    Stillings, Lisa L.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Selenium (Se) was discovered in 1817 in pyrite from copper mines in Sweden. It is a trace element in Earth’s crust, with an abundance of three to seven orders of magnitude less than the major rock-forming elements. Commercial use of selenium began in the United States in 1910, when it was used as a pigment for paints, ceramic glazes, and red glass. Since that time, it has had many other economic uses—notably, in the 1930s and 1940s, when it was used in rectifiers (which change alternating current to direct current), and in the 1960s, when it began to be used in the liner of photocopier drums. In the 21st century, other compounds have replaced selenium in these older products; modern uses for selenium include energy-efficient windows that limit heat transfer and thin-film photovoltaic cells that convert solar energy into electricity.In Earth’s crust, selenium is found as selenide minerals, selenate and selenite salts, and as substitution for sulfur in sulfide minerals. It is the sulfide minerals, most commonly those in porphyry copper deposits, that provide the bulk of the selenium produced for the international commodity market. Selenium is obtained as a byproduct of copper refining and recovered from the anode slimes generated in electrolytic production of copper. Because of this, the countries that have the largest resources and (or) reserves of copper also have the largest resources and (or) reserves of selenium.Because selenium occurs naturally in Earth’s crust, its presence in air, water, and soil results from both geologic reactions and human activity. Selenium is found concentrated naturally in soils that overlie bedrock with high selenium concentrations. Selenium mining, processing, use in industrial and agricultural applications, and disposal may all contribute selenium to the environment. A well-known case of selenium contamination from agricultural practices was discovered in 1983 in the Kesterson National Wildlife Refuge in California. There

  7. SELENIUM MODIFIES THE METABOLISM AND TOXICITY OF ARSENIC IN PRIMARY RAT HEPATOCYTES

    Science.gov (United States)

    ABSTRACTSelenium Modifies the Metabolism and Toxicity of Arsenic in Primary Rat Hepatocytes. Miroslav Styblo, David J. Thomas (2000) Toxicol. Appl. Pharmacol. Arsenic and selenium are metalloids with similar chemical properties and metabolic fates. Inorganic arsenic (iAs...

  8. Selenium uptake, translocation, assimilation and metabolic fate in plants.

    Science.gov (United States)

    Sors, T G; Ellis, D R; Salt, D E

    2005-12-01

    The chemical and physical resemblance between selenium (Se) and sulfur (S) establishes that both these elements share common metabolic pathways in plants. The presence of isologous Se and S compounds indicates that these elements compete in biochemical processes that affect uptake, translocation and assimilation throughout plant development. Yet, minor but crucial differences in reactivity and other metabolic interactions infer that some biochemical processes involving Se may be excluded from those relating to S. This review examines the current understanding of physiological and biochemical relationships between S and Se metabolism by highlighting their similarities and differences in relation to uptake, transport and assimilation pathways as observed in Se hyperaccumulator and non-accumulator plant species. The exploitation of genetic resources used in bioengineering strategies of plants is illuminating the function of sulfate transporters and key enzymes of the S assimilatory pathway in relation to Se accumulation and final metabolic fate. These strategies are providing the basic framework by which to resolve questions relating to the essentiality of Se in plants and the mechanisms utilized by Se hyperaccumulators to circumvent toxicity. In addition, such approaches may assist in the future application of genetically engineered Se accumulating plants for environmental renewal and human health objectives.

  9. Association between Toenail Mercury and Metabolic Syndrome Is Modified by Selenium

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    Kyong Park

    2016-07-01

    Full Text Available Background: Although Asian populations consume relatively large amounts of fish and seafood and have a high prevalence of metabolic diseases, few studies have investigated the association between chronic mercury exposure and metabolic syndrome and its effect modification by selenium. Methods: We analyzed baseline data from the Trace Element Study of Korean Adults in the Yeungnam area. Participants included 232 men and 269 women, aged 35 years or older, who had complete data regarding demographic, lifestyle, diet, toenail mercury and selenium levels, and health. Toenail mercury and selenium concentrations were measured using instrumental neutron-activation analysis. The metabolic biomarker levels were obtained through biannual medical checkups. Results: Higher toenail mercury levels were associated with habitual consumption of whale and shark meats, older age, obesity, smoking, alcohol drinking, and higher household income. Multivariable analysis showed a positive association between toenail mercury exposure and metabolic syndrome. In addition, this association was significantly stronger at lower selenium levels and was weaker at higher selenium levels. Conclusion: The possible harmful effects of mercury on metabolic syndrome may be attenuated by high levels of selenium. Future studies are needed to suggest optimal dietary guidelines regarding fish and selenium intakes, particularly for Asians with high levels of fish intake.

  10. Features of selenium metabolism in humans living under the conditions of North European Russia.

    Science.gov (United States)

    Parshukova, Olga; Potolitsyna, Natalya; Shadrina, Vera; Chernykh, Aleksei; Bojko, Evgeny

    2014-08-01

    Selenium supplementation and its effects on Northerners have been little studied. The aim of our study was to assess the selenium levels of the inhabitants of North European Russia, the seasonal aspects of selenium supplementation, and the interrelationships between selenium levels and the levels of thyroid gland hormones. To study the particular features of selenium metabolism in Northerners over the course of 1 year, 19 healthy male Caucasian volunteers (18-21 years old) were recruited for the present study. The subjects were military guards in a Northern European region of Russia (Syktyvkar, Russia, 62°N latitude) who spent 6-10-h outdoors daily. The study was conducted over a 12-month period. Selenium levels, glutathione peroxidase (GP) activity, as well as total triiodothyronine (T3), total thyroxin (T4), free thyroxin, free triiodothyronine, and thyrotropin (TSH) levels, were determined in the blood serum. The study subjects showed low levels of plasma selenium throughout the year. We observed a noticeable decrease in plasma selenium levels during the period from May to August, with the lowest levels in July. Selenium levels in the military guards correlated with the levels of selenium-dependent GP enzyme activity throughout the year. Additionally, we demonstrated a significant correlation between selenium and pituitary-thyroid axis hormones (total T3, free T4, and TSH) in periods in which plasma selenium levels were lower than the established normal ranges. Over the course of 1 year, low levels of plasma selenium affect GP activity and thyroid hormone levels in humans living in North European Russia.

  11. Serum selenium concentration is associated with metabolic factors in the elderly: a cross-sectional study

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    Huang Hui-Ying

    2010-05-01

    Full Text Available Abstract Background Selenium is an essential micronutrient known for its antioxidant function. However, the association of serum selenium with lipid profiles and fasting glucose are inconsistent in populations with average intake of selenium. Furthermore, there were few studies conducted specifically for the elderly. This study examined the relationship of serum selenium concentration with serum lipids and fasting glucose in the Taiwanese elderly population. Methods This was a cross-sectional study of 200 males and females aged 65-85 years (mean 71.5 ± 4.6 years from Taipei, Taiwan. Serum selenium was measured by inductively coupled plasma-mass spectrometer. The association between serum selenium and metabolic factors was examined using a multivariate linear regression analysis after controlling several confounders. Results The mean serum selenium concentration was 1.14 μmol/L, without significant difference between sexes. Total cholesterol, triglycerides, and LDL cholesterol increased significantly with serum selenium concentration (P P P P Conclusions Total cholesterol, triglycerides, and LDL cholesterol, and fasting serum glucose concentrations increased significantly with serum selenium concentration in the Taiwanese elderly. The underlying mechanism warrants further research.

  12. Effect of selenium deficiency on 75Se and 45Ca metabolism in chicks

    International Nuclear Information System (INIS)

    Edwardly, J.S.

    1981-01-01

    Two hundred, 1 day old broiler chicks were used to study the effect of selenium deficiency on 75 Se and 45 Ca metabolism in chicks. The chicks were randomly divided into five groups. One group was fed a purified basal diet low in selenium ( 75 Se or 45 Ca. Levels of radioisotopes in blood and tissue, as well as total body excretion of radioactivity were determined. Whole body retention of 75 Se was significantly higher (p 45 Ca was significantly higher in selenium deficient chicks than in supplemented animals. Total Ca concentration in muscle was also higher in this group. Studies of red cell uptake of 75 Se demonstrated a clear difference between Se repleted and selenium deficient groups. (author)

  13. Investigation of the selenium metabolism in cancer cell lines

    DEFF Research Database (Denmark)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan

    2011-01-01

    The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line...... (Jurkat E6-1) were incubated with five selenium compounds representing inorganic as well as organic Se compounds in different oxidation states. Selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), methylseleninic acid (MeSeA), selenite and selenate in the concentration range 5-100 mu M were...... incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size...

  14. Effects of cyanide on selenium metabolism in rats

    International Nuclear Information System (INIS)

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

    1984-01-01

    Adult male rats were given drinking water containing either 0 or 150 ppm cyanide for 2 weeks. They were then injected with 5 microCi 75 Se-selenite, and excretion of radioactivity in urine and feces was determined. No difference in excretion of 75 Se occurred during the rapid phase, but the cyanide-treated rats (T1/2 28 days) excreted significantly more 75 Se in urine than control (T1/2 38 days) rats. Cyanide had no effect on excretion of 75 Se in feces or on the distribution of 75 Se in cytosolic proteins in liver, kidney, muscle or testes. In a second experiment weanling male rats were given water with either 0 or 150 ppm cyanide and were killed for glutathione peroxidase assay and selenium analysis in blood, kidney, liver, muscle and testes after 3, 6 or 9 weeks of treatment. Glutathione peroxidase activity and selenium concentrations were significantly reduced by cyanide in all tissues except testes

  15. The Effect of Selenium Supplementation on Glucose Homeostasis and the Expression of Genes Related to Glucose Metabolism

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    Ewa Jablonska

    2016-12-01

    Full Text Available The aim of the study was to evaluate the effect of selenium supplementation on the expression of genes associated with glucose metabolism in humans, in order to explain the unclear relationship between selenium and the risk of diabetes. For gene expression analysis we used archival samples of cDNA from 76 non-diabetic subjects supplemented with selenium in the previous study. The supplementation period was six weeks and the daily dose of selenium was 200 µg (as selenium yeast. Blood for mRNA isolation was collected at four time points: before supplementation, after two and four weeks of supplementation, and after four weeks of washout. The analysis included 15 genes encoding selected proteins involved in insulin signaling and glucose metabolism. In addition, HbA1c and fasting plasma glucose were measured at three and four time points, respectively. Selenium supplementation was associated with a significantly decreased level of HbA1c but not fasting plasma glucose (FPG and significant down-regulation of seven genes: INSR, ADIPOR1, LDHA, PDHA, PDHB, MYC, and HIF1AN. These results suggest that selenium may affect glycemic control at different levels of regulation, linked to insulin signaling, glycolysis, and pyruvate metabolism. Further research is needed to investigate mechanisms of such transcriptional regulation and its potential implication in direct metabolic effects.

  16. Metabolic disruption in context: Clinical avenues for synergistic perturbations in energy homeostasis by endocrine disrupting chemicals.

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    Sargis, Robert M

    2015-01-01

    The global epidemic of metabolic disease is a clear and present danger to both individual and societal health. Understanding the myriad factors contributing to obesity and diabetes is essential for curbing their decades-long expansion. Emerging data implicate environmental endocrine disrupting chemicals (EDCs) in the pathogenesis of metabolic diseases such as obesity and diabetes. The phenylsulfamide fungicide and anti-fouling agent tolylfluanid (TF) was recently added to the list of EDCs promoting metabolic dysfunction. Dietary exposure to this novel metabolic disruptor promoted weight gain, increased adiposity, and glucose intolerance as well as systemic and cellular insulin resistance. Interestingly, the increase in body weight and adipose mass was not a consequence of increased food consumption; rather, it may have resulted from disruptions in diurnal patterns of energy intake, raising the possibility that EDCs may promote metabolic dysfunction through alterations in circadian rhythms. While these studies provide further evidence that EDCs may promote the development of obesity and diabetes, many questions remain regarding the clinical factors that modulate patient-specific consequences of EDC exposure, including the impact of genetics, diet, lifestyle, underlying disease, pharmacological treatments, and clinical states of fat redistribution. Currently, little is known regarding the impact of these factors on an individual's susceptibility to environmentally-mediated metabolic disruption. Advances in these areas will be critical for translating EDC science into the clinic to enable physicians to stratify an individual's risk of developing EDC-induced metabolic disease and to provide direction for treating exposed patients.

  17. Elucidating the selenium and arsenic metabolic pathways following exposure to the non-hyperaccumulating Chlorophytum comosum, spider plant

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    Afton, Scott E.; Catron, Brittany; Caruso, Joseph A.

    2009-01-01

    Although many studies have investigated the metabolism of selenium and arsenic in hyperaccumulating plants for phytoremediation purposes, few have explored non-hyperaccumulating plants as a model for general contaminant exposure to plants. In addition, the result of simultaneous supplementation with selenium and arsenic has not been investigated in plants. In this study, Chlorophytum comosum, commonly known as the spider plant, was used to investigate the metabolism of selenium and arsenic after single and simultaneous supplementation. Size exclusion and ion-pairing reversed phase liquid chromatography were coupled to an inductively coupled plasma mass spectrometer to obtain putative metabolic information of the selenium and arsenic species in C. comosum after a mild aqueous extraction. The chromatographic results depict that selenium and arsenic species were sequestered in the roots and generally conserved upon translocation to the leaves. The data suggest that selenium was directly absorbed by C. comosum roots when supplemented with SeVI, but a combination of passive and direct absorption occurred when supplemented with SeIV due to the partial oxidation of SeIV to SeVI in the rhizosphere. Higher molecular weight selenium species were more prevalent in the roots of plants supplemented with SeIV, but in the leaves of plants supplemented with SeVI due to an increased translocation rate. When supplemented as AsIII, arsenic is proposed to be passively absorbed as AsIII and partially oxidized to AsV in the plant root. Although total elemental analysis demonstrates a selenium and arsenic antagonism, a compound containing selenium and arsenic was not present in the general aqueous extract of the plant. PMID:19273464

  18. INFLUENCE OF DIETARY SELENIUM SUPPLEMENTATION OF EWES ON PRODUCTION TRAITS, ANTIOXIDANT STATUS AND METABOLIC PROFILE OF LAMBS

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    Josip Novoselec

    2013-12-01

    Full Text Available The aim of this study was to determine the effect of dietary selenium supplementation (organic, inorganic of high pregnant ewes on the production traits of lambs, the concentration of selenium in the blood of ewes and their lambs, indicators of antioxidant status in the blood of ewes and their lambs, the metabolic profile of ewes and their lambs and concentrations of thyroid hormones. Ewes were in the last third of pregnancy, the average age of four years, healthy and in good condition, divided into three groups of 10 animals. The research lasted 4 months respectively, 2 months with ewes during high pregnancy, 2 months with ewes during lactation and on their lambs during suckling period. Ewes ration from control group one was composed from 300 g/day/animal feed mixture without addition of selenium and 150 g/day/animal barley and alfalfa hay that they had ad libitum. Feed mixture from second group of ewes was supplemented with 0.3 mg/kg organic form of selenium (Sel-Plex®, and feed mixture from third group with the same amount inorganic form of selenium (sodium selenite. Selenium supplementation of ewes feed mixture did not significantly influence on the production traits of their lambs postpartum. Selenium supplementation of ewes and their lambs had influence on a significant (P<0.01; P<0.05 increase in the concentration of selenium, GSH-Px and SOD in whole blood compared to control group of ewes. Organic selenium supplement had a more significant impact on the increase in concentration of selenium and GSH-Px in the blood. In the ewes and lambs blood was determined decrease of MDA with increasing concentrations of selenium in the blood. Generally, the selenium supplementation led to an increase (P<0.05 in the number of WBC and lymphocytes in the blood of ewes and lambs. Also, the increase in the number of RBC, HGB content and MCV in lambs and MCH as well as MCHC in ewes that had a selenium supplement in feed mixture were determined

  19. Circadian Rhythm and Sleep Disruption: Causes, Metabolic Consequences, and Countermeasures.

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    Potter, Gregory D M; Skene, Debra J; Arendt, Josephine; Cade, Janet E; Grant, Peter J; Hardie, Laura J

    2016-12-01

    Circadian (∼24-hour) timing systems pervade all kingdoms of life and temporally optimize behavior and physiology in humans. Relatively recent changes to our environments, such as the introduction of artificial lighting, can disorganize the circadian system, from the level of the molecular clocks that regulate the timing of cellular activities to the level of synchronization between our daily cycles of behavior and the solar day. Sleep/wake cycles are intertwined with the circadian system, and global trends indicate that these, too, are increasingly subject to disruption. A large proportion of the world's population is at increased risk of environmentally driven circadian rhythm and sleep disruption, and a minority of individuals are also genetically predisposed to circadian misalignment and sleep disorders. The consequences of disruption to the circadian system and sleep are profound and include myriad metabolic ramifications, some of which may be compounded by adverse effects on dietary choices. If not addressed, the deleterious effects of such disruption will continue to cause widespread health problems; therefore, implementation of the numerous behavioral and pharmaceutical interventions that can help restore circadian system alignment and enhance sleep will be important.

  20. Circadian Rhythm and Sleep Disruption: Causes, Metabolic Consequences, and Countermeasures

    Science.gov (United States)

    Skene, Debra J.; Arendt, Josephine; Cade, Janet E.; Grant, Peter J.; Hardie, Laura J.

    2016-01-01

    Circadian (∼24-hour) timing systems pervade all kingdoms of life and temporally optimize behavior and physiology in humans. Relatively recent changes to our environments, such as the introduction of artificial lighting, can disorganize the circadian system, from the level of the molecular clocks that regulate the timing of cellular activities to the level of synchronization between our daily cycles of behavior and the solar day. Sleep/wake cycles are intertwined with the circadian system, and global trends indicate that these, too, are increasingly subject to disruption. A large proportion of the world's population is at increased risk of environmentally driven circadian rhythm and sleep disruption, and a minority of individuals are also genetically predisposed to circadian misalignment and sleep disorders. The consequences of disruption to the circadian system and sleep are profound and include myriad metabolic ramifications, some of which may be compounded by adverse effects on dietary choices. If not addressed, the deleterious effects of such disruption will continue to cause widespread health problems; therefore, implementation of the numerous behavioral and pharmaceutical interventions that can help restore circadian system alignment and enhance sleep will be important. PMID:27763782

  1. Selenium species-dependent toxicity, bioavailability and metabolic transformations in Caenorhabditis elegans.

    Science.gov (United States)

    Rohn, Isabelle; Marschall, Talke Anu; Kroepfl, Nina; Jensen, Kenneth Bendix; Aschner, Michael; Tuck, Simon; Kuehnelt, Doris; Schwerdtle, Tanja; Bornhorst, Julia

    2018-05-17

    The essential micronutrient selenium (Se) is required for various systemic functions, but its beneficial range is narrow and overexposure may result in adverse health effects. Additionally, the chemical form of the ingested selenium contributes crucially to its health effects. While small Se species play a major role in Se metabolism, their toxicological effects, bioavailability and metabolic transformations following elevated uptake are poorly understood. Utilizing the tractable invertebrate Caenorhabditis elegans allowed for an alternative approach to study species-specific characteristics of organic and inorganic Se forms in vivo, revealing remarkable species-dependent differences in the toxicity and bioavailability of selenite, selenomethionine (SeMet) and Se-methylselenocysteine (MeSeCys). An inverse relationship was found between toxicity and bioavailability of the Se species, with the organic species displaying a higher bioavailability than the inorganic form, yet being less toxic. Quantitative Se speciation analysis with HPLC/mass spectrometry revealed a partial metabolism of SeMet and MeSeCys. In SeMet exposed worms, identified metabolites were Se-adenosylselenomethionine (AdoSeMet) and Se-adenosylselenohomocysteine (AdoSeHcy), while worms exposed to MeSeCys produced Se-methylselenoglutathione (MeSeGSH) and γ-glutamyl-MeSeCys (γ-Glu-MeSeCys). Moreover, the possible role of the sole selenoprotein in the nematode, thioredoxin reductase-1 (TrxR-1), was studied comparing wildtype and trxr-1 deletion mutants. Although a lower basal Se level was detected in trxr-1 mutants, Se toxicity and bioavailability following acute exposure was indistinguishable from wildtype worms. Altogether, the current study demonstrates the suitability of C. elegans as a model for Se species dependent toxicity and metabolism, while further research is needed to elucidate TrxR-1 function in the nematode.

  2. The role of selenium in the metabolism of 45Ca and 99Sr in the bones of hens

    International Nuclear Information System (INIS)

    Nowosad, R.

    1977-01-01

    Under experimental conditions it was stated that the application of selenium at the dose of 5 mcg per animal led to some disturbances in mineral metabolism in the skeletal system of hens. That was expressed by a decrease of ash content in died mass, a decrease of 45 Ca and 90 Sr in bones, and the diminished activity of calcium. (author)

  3. Mercury exposure, nutritional deficiencies and metabolic disruptions may affect learning in children

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    Patrick Lyn

    2009-10-01

    Full Text Available Abstract Among dietary factors, learning and behavior are influenced not only by nutrients, but also by exposure to toxic food contaminants such as mercury that can disrupt metabolic processes and alter neuronal plasticity. Neurons lacking in plasticity are a factor in neurodevelopmental disorders such as autism and mental retardation. Essential nutrients help maintain normal neuronal plasticity. Nutritional deficiencies, including deficiencies in the long chain polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid, the amino acid methionine, and the trace minerals zinc and selenium, have been shown to influence neuronal function and produce defects in neuronal plasticity, as well as impact behavior in children with attention deficit hyperactivity disorder. Nutritional deficiencies and mercury exposure have been shown to alter neuronal function and increase oxidative stress among children with autism. These dietary factors may be directly related to the development of behavior disorders and learning disabilities. Mercury, either individually or in concert with other factors, may be harmful if ingested in above average amounts or by sensitive individuals. High fructose corn syrup has been shown to contain trace amounts of mercury as a result of some manufacturing processes, and its consumption can also lead to zinc loss. Consumption of certain artificial food color additives has also been shown to lead to zinc deficiency. Dietary zinc is essential for maintaining the metabolic processes required for mercury elimination. Since high fructose corn syrup and artificial food color additives are common ingredients in many foodstuffs, their consumption should be considered in those individuals with nutritional deficits such as zinc deficiency or who are allergic or sensitive to the effects of mercury or unable to effectively metabolize and eliminate it from the body.

  4. Absorption, distribution, metabolism and excretion of selenium following oral administration of elemental selenium nanoparticles or selenite in rats

    DEFF Research Database (Denmark)

    Löschner, Katrin; Hadrup, Niels; Hansen, Marianne

    2014-01-01

    A suspension of nanoparticles of BSA-stabilized red amorphous elemental selenium (Se) or an aqueous solution of sodium selenite was repeatedly administered by oral gavage for 28 days at 0.05 mg/kg bw/day (low dose) or at 0.5 mg/kg bw/day (high dose) as Se to female rats. Prior to administration...

  5. [Selenium treatment in thyreopathies].

    Science.gov (United States)

    Sotak, Štefan

    Selenium (latin Selenium) is a micronutrient embedded in several proteins. In adults, the thyroid is the organ with the highest amount of selenium per gram of tissue. Selenium levels in the body depend on the characteristics of the population and its diet and geographic area. In the thyroid, selenium is required for the antioxidant function and for the metabolism of thyroid hormones. The literature suggests that selenium supplementation of patients with Hashimotos thyroiditis is associated with a reduction in antithyroperoxidase antibody levels. Selenium supplementation also in mild Graves orbitopathy is associated with delayed progression of ocular disorders. As a consequence of this observation The European Group on Graves Orbitopathy recommend six months selenium preparates supportive therapy for patients with mild form of Graves orbitopathy.Key words: Graves-Basedows disease - Hashimotos thyroiditis - selenium - supplementation.

  6. The interactive effects of mercury and selenium on metabolic profiles, gene expression and antioxidant enzymes in halophyte Suaeda salsa.

    Science.gov (United States)

    Liu, Xiaoli; Lai, Yongkai; Sun, Hushan; Wang, Yiyan; Zou, Ning

    2016-04-01

    Suaeda salsa is the pioneer halophyte in the Yellow River Delta and was consumed as a popular vegetable. Mercury has become a highly risky contaminant in the sediment of intertidal zones of the Yellow River Delta. In this work, we investigated the interactive effects of mercury and selenium in S. salsa on the basis of metabolic profiling, antioxidant enzyme activities and gene expression quantification. Our results showed that mercury exposure (20 μg L(-1)) inhibited plant growth of S. salsa and induced significant metabolic responses and altered expression levels of INPS, CMO, and MDH in S. salsa samples, together with the increased activities of antioxidant enzymes including SOD and POD. Overall, these results indicated osmotic and oxidative stresses, disturbed protein degradation and energy metabolism change in S. salsa after mercury exposures. Additionally, the addition of selenium could induce both antagonistic and synergistic effects including alleviating protein degradation and aggravating osmotic stress caused by mercury. © 2014 Wiley Periodicals, Inc.

  7. Metabolic targets of endocrine disrupting chemicals assessed by cord blood transcriptome profiling

    DEFF Research Database (Denmark)

    Remy, Sylvie; Govarts, Eva; Wens, Britt

    2016-01-01

    Early life exposure to endocrine disrupting chemicals (EDCs) has been frequently associated with impaired perinatal growth, an important risk factor for later onset of metabolic disorders. We analyzed whether the cord blood transcriptome showed early indications of alterations in metabolic...

  8. Acute exposure to selenium disrupts associative conditioning and long-term memory recall in honey bees (Apis mellifera).

    Science.gov (United States)

    Burden, Christina M; Elmore, Christopher; Hladun, Kristen R; Trumble, John T; Smith, Brian H

    2016-05-01

    A plethora of toxic compounds - including pesticides, heavy metals, and metalloids - have been detected in honey bees (Apis mellifera) and their colonies. One such compound is selenium, which bees are exposed to by consuming nectar and pollen from flowers grown in contaminated areas. Though selenium is lethal at high concentrations, sublethal exposure may also impair honey bees' ability to function normally. Examining the effect of selenium exposure on learning and memory provides a sensitive assay with which to identify sublethal effects on honey bee health and behavior. To determine whether sublethal selenium exposure causes learning and memory deficits, we used proboscis extension reflex conditioning coupled with recall tests 30min and 24h post-conditioning. We exposed forager honey bees to a single sublethal dose of selenium, and 3h later we used an olfactory conditioning assay to train the bees to discriminate between one odor associated with sucrose-reinforcement and a second unreinforced odor. Following conditioning we tested short- and long-term recall of the task. Acute exposure to as little as 1.8ng of an inorganic form of selenium (sodium selenate) before conditioning caused a reduction in behavioral performance during conditioning. And, exposure to 18ng of either an inorganic form (sodium selenate) or an organic form (methylseleno-l-cysteine) of selenium caused a reduction in the bees' performance during the long-term recall test. These concentrations of selenium are lower than those found in the nectar of plants grown in selenium-contaminated soil, indicating that even low-grade selenium toxicity produces significant learning and memory impairments. This may reduce foragers' ability to effectively gather resources for the colony or nurse bees' ability to care for and maintain a healthy colony. Copyright © 2016. Published by Elsevier Inc.

  9. Blood selenium concentrations and enzyme activities related to glutathione metabolism in wild emperor geese

    Science.gov (United States)

    Franson, J. Christian; Hoffman, David J.; Schmutz, Joel A.

    2002-01-01

    In 1998, we collected blood samples from 63 emperor geese (Chen canagica) on their breeding grounds on the Yukon-Kuskokwim Delta (YKD) in western Alaska, USA. We studied the relationship between selenium concentrations in whole blood and the activities of glutathione peroxidase and glutathione reductase in plasma. Experimental studies have shown that plasma activities of these enzymes are useful biomarkers of selenium-induced oxidative stress, but little information is available on their relationship to selenium in the blood of wild birds. Adult female emperor geese incubating their eggs in mid-June had a higher mean concentration of selenium in their blood and a greater activity of glutathione peroxidase in their plasma than adult geese or goslings that were sampled during the adult flight feathermolting period in late July and early August. Glutathione peroxidase activity was positively correlated with the concentration of selenium in the blood of emperor geese, and the rate of increase relative to selenium was greater in goslings than in adults. The activity of glutathione reductase was greatest in the plasma of goslings and was greater in molting adults than incubating females but was not significantly correlated with selenium in the blood of adults or goslings. Incubating female emperor geese had high selenium concentrations in their blood, accompanied by increased glutathione peroxidase activity consistent with early oxidative stress. These findings indicate that further study of the effects of selenium exposure, particularly on reproductive success, is warranted in this species.

  10. Metabolic response to selenium supplementation in women with polycystic ovary syndrome: a randomized, double-blind, placebo-controlled trial.

    Science.gov (United States)

    Jamilian, Mehri; Razavi, Maryamalsadat; Fakhrie Kashan, Zohreh; Ghandi, Yasser; Bagherian, Tayebeh; Asemi, Zatollah

    2015-06-01

    We are aware of no study examining the effects of selenium supplementation on metabolic profiles of patients with polycystic ovary syndrome (PCOS). This study was conducted to evaluate the effects of selenium supplementation on glucose homeostasis parameters and lipid concentrations in women with PCOS. This randomized, double-blind, placebo-controlled trial was conducted among 70 women diagnosed with PCOS and aged 18-40 years old. Participants were randomly divided into two groups to receive 200 μg per day selenium supplements (N = 35) or placebo (N = 35) for 8 weeks. Fasting blood samples were taken at baseline and after 8 weeks intervention to quantify glucose, insulin and lipid concentrations. After 8 weeks of intervention, subjects who received selenium supplements had significantly decreased serum insulin levels (-29·83 ± 47·29 vs +9·07 ± 77·12 pmol/l, P = 0·013), homeostasis model of assessment-insulin resistance (HOMA-IR) (-1·15 ± 1·81 vs +0·42 ± 3·09, P = 0·011), homeostatic model assessment-beta-cell function (HOMA-B) (-19·06 ± 30·95 vs +4·55 ± 47·99, P = 0·017) and increased quantitative insulin sensitivity check index (QUICKI) (+0·03 ± 0·04 vs +0·0009 ± 0·05, P = 0·032) compared with placebo. In addition, supplementation with selenium resulted in a significant reduction in serum triglycerides (-0·14 ± 0·55 vs +0·11 ± 0·30 mmol/l, P = 0·025) and VLDL-C concentrations (-0·03 ± 0·11 vs +0·02 ± 0·06 mmol/l, P = 0·025) compared with placebo. In conclusion, 200 microgram per day selenium supplementation for 8 weeks among PCOS women had beneficial effects on insulin metabolism parameters, triglycerides and VLDL-C levels; however, it did not affect FPG and other lipid profiles. © 2014 John Wiley & Sons Ltd.

  11. Gemfibrozil disrupts the metabolism of circulating lipids in bobwhite quails.

    Science.gov (United States)

    Bussière-Côté, Sophie; Omlin, Teye; de Càssia Pinheiro, Eliana; Weber, Jean-Michel

    2016-01-01

    The circulating lipids of birds play essential roles for egg production and as an energy source for flight and thermogenesis. How lipid-lowering pharmaceuticals geared to prevent heart disease in humans and that are routinely released in the environment affect their metabolism is unknown. This study assesses the impact of the popular drug gemfibrozil (GEM) on the plasma phospholipids (PL), neutral lipids (NL), and nonesterified fatty acids (NEFA) of bobwhite quails (Colinus virginianus). Results show that bird lipoproteins are rapidly altered by GEM, even at environmentally-relevant doses. After 4 days of exposure, pharmacological amounts cause an 83% increase in circulating PL levels, a major decrease in average lipoprotein size measured as a 56% drop in the NL/PL ratio, and important changes in the fatty acid composition of PL and NEFA (increases in fatty acid unsaturation). The levels of PL carrying all individual fatty acids except arachidonate are strongly stimulated. The large decrease in bird lipoprotein size may reflect the effects seen in humans: lowering of LDL that can cause atherosclerosis and stimulation of HDL that promote cholesterol disposal. Lower (environmental) doses of GEM cause a reduction of %palmitate in all the plasma lipid fractions of quails, but particularly in the core triacylglycerol of lipoproteins (NL). No changes in mRNA levels of bird peroxisome proliferator-activated receptor (PPAR) could be demonstrated. The disrupting effects of GEM on circulating lipids reported here suggest that the pervasive presence of this drug in the environment could jeopardize reproduction and migratory behaviours in wild birds. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Metabolic deposition of selenium and cadmium into the hair and other tissues of the guinea pig

    International Nuclear Information System (INIS)

    Chatt, A.; Holzbecher, J.; Katz, S.A.

    1990-01-01

    To better understand the significance of hair trace-element measurements and their relationships with the trace-element levels in body organs and fluids, a series of controlled animal experiments were conducted in which several trace elements were periodically measured (neutron activation and AA) during a 90-day chronic exposure to selenium and cadmium. Chronic selenium exposure appeared to be reflected by elevated selenium levels in the hair, kidneys, and liver. Chronic cadmium exposure, although reflected by kidney and liver elevation, appeared not to be reflected by corresponding increases in its concentration in the hair

  13. Metabolic effects of bariatric surgery in mouse models of circadian disruption.

    Science.gov (United States)

    Arble, D M; Sandoval, D A; Turek, F W; Woods, S C; Seeley, R J

    2015-08-01

    Mounting evidence supports a link between circadian disruption and metabolic disease. Humans with circadian disruption (for example, night-shift workers) have an increased risk of obesity and cardiometabolic diseases compared with the non-disrupted population. However, it is unclear whether the obesity and obesity-related disorders associated with circadian disruption respond to therapeutic treatments as well as individuals with other types of obesity. Here, we test the effectiveness of the commonly used bariatric surgical procedure, Vertical Sleeve Gastrectomy (VSG), in mouse models of genetic and environmental circadian disruption. VSG led to a reduction in body weight and fat mass in both Clock(Δ19) mutant and constant-light mouse models (Pdisruption. Interestingly, the decrease in body weight occurred without altering diurnal feeding or activity patterns (P>0.05). Within circadian-disrupted models, VSG also led to improved glucose tolerance and lipid handling (Pdisruption, and that the potent effects of bariatric surgery are orthogonal to circadian biology. However, as the effects of bariatric surgery are independent of circadian disruption, VSG cannot be considered a cure for circadian disruption. These data have important implications for circadian-disrupted obese patients. Moreover, these results reveal new information about the metabolic pathways governing the effects of bariatric surgery as well as of circadian disruption.

  14. Use of external metabolizing systems when testing for endocrine disruption in the T-screen assay

    DEFF Research Database (Denmark)

    Taxvig, Camilla; Olesen, Pelle Thonning; Nellemann, Christine Lydia

    2011-01-01

    Although, it is well-established that information on the metabolism of a substance is important in the evaluation of its toxic potential, there is limited experience with incorporating metabolic aspects into in vitro tests for endocrine disrupters. The aim of the current study was a) to study...

  15. Clinical and Metabolic Response to Selenium Supplementation in Pregnant Women at Risk for Intrauterine Growth Restriction: Randomized, Double-Blind, Placebo-Controlled Trial.

    Science.gov (United States)

    Mesdaghinia, Elaheh; Rahavi, Azam; Bahmani, Fereshteh; Sharifi, Nasrin; Asemi, Zatollah

    2017-07-01

    Data on the effects of selenium supplementation on clinical signs and metabolic profiles in women at risk for intrauterine growth restriction (IUGR) are scarce. This study was designed to assess the effects of selenium supplementation on clinical signs and metabolic status in pregnant women at risk for IUGR. This randomized double-blind placebo-controlled clinical trial was performed among 60 women at risk for IUGR according to abnormal uterine artery Doppler waveform. Participants were randomly assigned to intake either 100 μg selenium supplements as tablet (n = 30) or placebo (n = 30) for 10 weeks between 17 and 27 weeks of gestation. After 10 weeks of selenium administration, a higher percentage of women in the selenium group had pulsatility index (PI) of women at risk for IUGR resulted in improved PI, TAC, GSH, hs-CRP, and markers of insulin metabolism and HDL-C levels, but it did not affect MDA, NO, FPG, and other lipid profiles.Clinical trial registration number http://www.irct.ir : IRCT201601045623N64.

  16. Disrupted Bone Metabolism in Long-Term Bedridden Patients.

    Directory of Open Access Journals (Sweden)

    Keiko Eimori

    Full Text Available Bedridden patients are at risk of osteoporosis and fractures, although the long-term bone metabolic processes in these patients are poorly understood. Therefore, we aimed to determine how long-term bed confinement affects bone metabolism.This study included 36 patients who had been bedridden from birth due to severe immobility. Bone mineral density and bone metabolism markers were compared to the bedridden period in all study patients. Changes in the bone metabolism markers during a follow-up of 12 years were studied in 17 patients aged <30 years at baseline.The bone mineral density was reduced (0.58±0.19 g/cm3, and the osteocalcin (13.9±12.4 ng/mL and urine N-terminal telopeptide (NTX levels (146.9±134.0 mM BCE/mM creatinine were greater than the cutoff value for predicting fracture. Among the bone metabolism markers studied, osteocalcin and NTX were negatively associated with the bedridden period. During the follow-up, osteocalcin and parathyroid hormone were decreased, and the 25(OH vitamin D was increased. NTX at baseline was negatively associated with bone mineral density after 12 years.Unique bone metabolic abnormalities were found in patients who had been bedridden for long periods, and these metabolic abnormalities were altered by further bed confinement. Appropriate treatment based on the unique bone metabolic changes may be important in long-term bedridden patients.

  17. Disruption of BCAA metabolism in mice impairs exercise metabolism and endurance.

    Science.gov (United States)

    She, Pengxiang; Zhou, Yingsheng; Zhang, Zhiyou; Griffin, Kathleen; Gowda, Kavitha; Lynch, Christopher J

    2010-04-01

    Exercise enhances branched-chain amino acid (BCAA) catabolism, and BCAA supplementation influences exercise metabolism. However, it remains controversial whether BCAA supplementation improves exercise endurance, and unknown whether the exercise endurance effect of BCAA supplementation requires catabolism of these amino acids. Therefore, we examined exercise capacity and intermediary metabolism in skeletal muscle of knockout (KO) mice of mitochondrial branched-chain aminotransferase (BCATm), which catalyzes the first step of BCAA catabolism. We found that BCATm KO mice were exercise intolerant with markedly decreased endurance to exhaustion. Their plasma lactate and lactate-to-pyruvate ratio in skeletal muscle during exercise and lactate release from hindlimb perfused with high concentrations of insulin and glucose were significantly higher in KO than wild-type (WT) mice. Plasma and muscle ammonia concentrations were also markedly higher in KO than WT mice during a brief bout of exercise. BCATm KO mice exhibited 43-79% declines in the muscle concentration of alanine, glutamine, aspartate, and glutamate at rest and during exercise. In response to exercise, the increments in muscle malate and alpha-ketoglutarate were greater in KO than WT mice. While muscle ATP concentration tended to be lower, muscle IMP concentration was sevenfold higher in KO compared with WT mice after a brief bout of exercise, suggesting elevated ammonia in KO is derived from the purine nucleotide cycle. These data suggest that disruption of BCAA transamination causes impaired malate/aspartate shuttle, thereby resulting in decreased alanine and glutamine formation, as well as increases in lactate-to-pyruvate ratio and ammonia in skeletal muscle. Thus BCAA metabolism may regulate exercise capacity in mice.

  18. Disrupted Bone Metabolism in Long-Term Bedridden Patients.

    Science.gov (United States)

    Eimori, Keiko; Endo, Naoto; Uchiyama, Seiji; Takahashi, Yoshinori; Kawashima, Hiroyuki; Watanabe, Kei

    2016-01-01

    Bedridden patients are at risk of osteoporosis and fractures, although the long-term bone metabolic processes in these patients are poorly understood. Therefore, we aimed to determine how long-term bed confinement affects bone metabolism. This study included 36 patients who had been bedridden from birth due to severe immobility. Bone mineral density and bone metabolism markers were compared to the bedridden period in all study patients. Changes in the bone metabolism markers during a follow-up of 12 years were studied in 17 patients aged bedridden period. During the follow-up, osteocalcin and parathyroid hormone were decreased, and the 25(OH) vitamin D was increased. NTX at baseline was negatively associated with bone mineral density after 12 years. Unique bone metabolic abnormalities were found in patients who had been bedridden for long periods, and these metabolic abnormalities were altered by further bed confinement. Appropriate treatment based on the unique bone metabolic changes may be important in long-term bedridden patients.

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

    Science.gov (United States)

    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...

  20. Metabolism in rats of selenium from intrinsically and extrinsically labeled isolated soy protein

    International Nuclear Information System (INIS)

    Mason, A.C.; Weaver, C.M.

    1986-01-01

    Absorption, retention and tissue accumulation by rats of 75 Se from intrinsically labeled isolated soy protein were compared with utilization of 75 Se from the extrinsic sources of [ 75 Se]selenite, [ 75 Se]selenate or [ 75 Se]selenomethionine. Extrinsic sources of selenium were given by gavage or mixed with isolated soy protein. There were no differences in absorption and retention of 75 Se from intrinsically labeled soy diet compared to the three extrinsically labeled soy diets. Of the three extrinsic sources tested, 75 Se from selenate was better absorbed than from selenite or selenomethionine when incorporated into a soy diet. Absorption of 75 Se was significantly lower when given to animals in gavage solution than when mixed with soy diets. After a 14-d test period, retention of 75 Se was the same for all four soy diet groups. In gavaged groups, 75 Se from selenomethionine was retained to a greater extent than 75 Se from selenite. The liver, testes and kidney accumulated more 75 Se from the test meal than did the blood and lungs. In the testes more 75 Se from selenite and selenate was accumulated than from selenomethionine-labeled diets. Selenium absorption from the soy isolate source was very high (86-96%), indicating that, although soy does not normally contain high levels of selenium, the selenium present is well absorbed from this plant source

  1. Effect of selenium on the thyroid gland antioxidative metabolisms in rat model by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyung Seok; Choi, Jun Hyeok; JUng, Do Young; Kim, Jang Oh; Shin, Ji Hye; Min, Byung In [Inje University, Gimhae (Korea, Republic of)

    2017-03-15

    Selenium (Se), which is natural materials existing was known as an important component of selenoprotein, one of the important proteins responsible for the redox pump of a living body. Selenium was orally administered to Rat and irradiated with 10 Gy of radiation. Then, the thyroid gland was used as a target organ for 1 day, 7 days and 21 days to investigate the radiation protection effect of selenium (Se) through changes of blood components, thyroid hormones (T3, T4), antioxidant enzyme (GPx) activity and thyroid tissue changes. As a result, there was a significant protective effect of hematopoietic immune system(hemoglobin concentration, neutrophil, platelet)(p<0.05). The activity of Glutathione Peroxidase (GPx), the antioxidant enzyme, and the activity of the target organ, thyroid hormone (T3, T4), also showed significant activity changes (p<0.05). In the observation of tissue changes, it was confirmed that there was a protective effect of thyroid cell damage which caused the cell necrosis by radiation treatment. Therefore, it is considered that selenium(Se) can be utilized as a radiation defense agent by inducing immunogenic activity effect of a living body.

  2. Disruption?

    DEFF Research Database (Denmark)

    2016-01-01

    This is a short video on the theme disruption and entrepreneurship. It takes the form of an interview with John Murray......This is a short video on the theme disruption and entrepreneurship. It takes the form of an interview with John Murray...

  3. Aluminium stress disrupts metabolic performance of Plantago almogravensis plantlets transiently.

    Science.gov (United States)

    Grevenstuk, Tomás; Moing, Annick; Maucourt, Mickaël; Deborde, Catherine; Romano, Anabela

    2015-12-01

    Little is known about how tolerant plants cope with internalized aluminium (Al). Tolerant plants are known to deploy efficient detoxification mechanisms, however it is not known to what extent the primary and secondary metabolism is affected by Al. The aim of this work was to study the metabolic repercussions of Al stress in the tolerant plant Plantago almogravensis. P. almogravensis is well adapted to acid soils where high concentrations of free Al are found and has been classified as a hyperaccumulator. In vitro reared plantlets were used for this purpose in order to control Al exposure rigorously. The metabolome of P. almogravensis plantlets as well as its metabolic response to the supply of sucrose was characterized. The supply of sucrose leads to an accumulation of amino acids and secondary metabolites and consumption of carbohydrates that result from increased metabolic activity. In Al-treated plantlets the synthesis of amino acids and secondary metabolites is transiently impaired, suggesting that P. almogravensis is able to recover from the Al treatment within the duration of the trials. In the presence of Al the consumption of carbohydrate resources is accelerated. The content of some metabolic stress markers also demonstrates that P. almogravensis is highly adapted to Al stress.

  4. Internal correction of spectral interferences and mass bias for selenium metabolism studies using enriched stable isotopes in combination with multiple linear regression.

    Science.gov (United States)

    Lunøe, Kristoffer; Martínez-Sierra, Justo Giner; Gammelgaard, Bente; Alonso, J Ignacio García

    2012-03-01

    The analytical methodology for the in vivo study of selenium metabolism using two enriched selenium isotopes has been modified, allowing for the internal correction of spectral interferences and mass bias both for total selenium and speciation analysis. The method is based on the combination of an already described dual-isotope procedure with a new data treatment strategy based on multiple linear regression. A metabolic enriched isotope ((77)Se) is given orally to the test subject and a second isotope ((74)Se) is employed for quantification. In our approach, all possible polyatomic interferences occurring in the measurement of the isotope composition of selenium by collision cell quadrupole ICP-MS are taken into account and their relative contribution calculated by multiple linear regression after minimisation of the residuals. As a result, all spectral interferences and mass bias are corrected internally allowing the fast and independent quantification of natural abundance selenium ((nat)Se) and enriched (77)Se. In this sense, the calculation of the tracer/tracee ratio in each sample is straightforward. The method has been applied to study the time-related tissue incorporation of (77)Se in male Wistar rats while maintaining the (nat)Se steady-state conditions. Additionally, metabolically relevant information such as selenoprotein synthesis and selenium elimination in urine could be studied using the proposed methodology. In this case, serum proteins were separated by affinity chromatography while reverse phase was employed for urine metabolites. In both cases, (74)Se was used as a post-column isotope dilution spike. The application of multiple linear regression to the whole chromatogram allowed us to calculate the contribution of bromine hydride, selenium hydride, argon polyatomics and mass bias on the observed selenium isotope patterns. By minimising the square sum of residuals for the whole chromatogram, internal correction of spectral interferences and mass

  5. Nickel deficiency disrupts metabolism of ureides, amino acids, and organic acids of young pecan foliage.

    Science.gov (United States)

    Bai, Cheng; Reilly, Charles C; Wood, Bruce W

    2006-02-01

    The existence of nickel (Ni) deficiency is becoming increasingly apparent in crops, especially for ureide-transporting woody perennials, but its physiological role is poorly understood. We evaluated the concentrations of ureides, amino acids, and organic acids in photosynthetic foliar tissue from Ni-sufficient (Ni-S) versus Ni-deficient (Ni-D) pecan (Carya illinoinensis [Wangenh.] K. Koch). Foliage of Ni-D pecan seedlings exhibited metabolic disruption of nitrogen metabolism via ureide catabolism, amino acid metabolism, and ornithine cycle intermediates. Disruption of ureide catabolism in Ni-D foliage resulted in accumulation of xanthine, allantoic acid, ureidoglycolate, and citrulline, but total ureides, urea concentration, and urease activity were reduced. Disruption of amino acid metabolism in Ni-D foliage resulted in accumulation of glycine, valine, isoleucine, tyrosine, tryptophan, arginine, and total free amino acids, and lower concentrations of histidine and glutamic acid. Ni deficiency also disrupted the citric acid cycle, the second stage of respiration, where Ni-D foliage contained very low levels of citrate compared to Ni-S foliage. Disruption of carbon metabolism was also via accumulation of lactic and oxalic acids. The results indicate that mouse-ear, a key morphological symptom, is likely linked to the toxic accumulation of oxalic and lactic acids in the rapidly growing tips and margins of leaflets. Our results support the role of Ni as an essential plant nutrient element. The magnitude of metabolic disruption exhibited in Ni-D pecan is evidence of the existence of unidentified physiological roles for Ni in pecan.

  6. Selenium, selenoproteins and the thyroid gland: interactions in health and disease.

    Science.gov (United States)

    Schomburg, Lutz

    2011-10-18

    The trace element selenium is an essential micronutrient that is required for the biosynthesis of selenocysteine-containing selenoproteins. Most of the known selenoproteins are expressed in the thyroid gland, including some with still unknown functions. Among the well-characterized selenoproteins are the iodothyronine deiodinases, glutathione peroxidases and thioredoxin reductases, enzymes involved in thyroid hormone metabolism, regulation of redox state and protection from oxidative damage. Selenium content in selenium-sensitive tissues such as the liver, kidney or muscle and expression of nonessential selenoproteins, such as the glutathione peroxidases GPx1 and GPx3, is controlled by nutritional supply. The thyroid gland is, however, largely independent from dietary selenium intake and thyroid selenoproteins are preferentially expressed. As a consequence, no explicit effects on thyroid hormone profiles are observed in healthy individuals undergoing selenium supplementation. However, low selenium status correlates with risk of goiter and multiple nodules in European women. Some clinical studies have demonstrated that selenium-deficient patients with autoimmune thyroid disease benefit from selenium supplementation, although the data are conflicting and many parameters must still be defined. The baseline selenium status of an individual could constitute the most important parameter modifying the outcome of selenium supplementation, which might primarily disrupt self-amplifying cycles of the endocrine-immune system interface rectifying the interaction of lymphocytes with thyroid autoantigens. Selenium deficiency is likely to constitute a risk factor for a feedforward derangement of the immune system-thyroid interaction, while selenium supplementation appears to dampen the self-amplifying nature of this derailed interaction.

  7. Selenium Sulfide

    Science.gov (United States)

    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 ...

  8. Hepatic arachidonic acid metabolism is disrupted after hexachlorobenzene treatment

    International Nuclear Information System (INIS)

    Billi de Catabbi, Silvia C.; Faletti, Alicia; Fuentes, Federico; San Martin de Viale, Leonor C.; Cochon, Adriana C.

    2005-01-01

    Hexaclorobenzene (HCB), one of the most persistent environmental pollutants, can cause a wide range of toxic effects including cancer in animals, and hepatotoxicity and porphyria both in humans and animals. In the present study, liver microsomal cytochrome P450 (CYP)-dependent arachidonic acid (AA) metabolism, hepatic PGE production, and cytosolic phospholipase A 2 (cPLA 2 ) activity were investigated in an experimental model of porphyria cutanea tarda induced by HCB. Female Wistar rats were treated with a single daily dose of HCB (100 mg kg -1 body weight) for 5 days and were sacrificed 3, 10, 17, and 52 days after the last dose. HCB treatment induced the accumulation of hepatic porhyrins from day 17 and increased the activities of liver ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), and aminopyrine N-demethylase (APND) from day 3 after the last dose. Liver microsomes from control and HCB-treated rats generated, in the presence of NADPH, hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatrienoic acids (EETs), 11,12-Di HETE, and ω-OH/ω-1-OH AA. HCB treatment caused an increase in total NADPH CYP-dependent AA metabolism, with a higher response at 3 days after the last HCB dose than at the other time points studied. In addition, HCB treatment markedly enhanced PGE production and release in liver slices. This HCB effect was time dependent and reached its highest level after 10 days. At this time cPLA 2 activity was shown to be increased. Unexpectedly, HCB produced a significant decrease in cPLA 2 activity on the 17th and 52nd day. Our results demonstrated for the first time that HCB induces both the cyclooxygenase and CYP-dependent AA metabolism. The effects of HCB on AA metabolism were previous to the onset of a marked porphyria and might contribute to different aspects of HCB-induced liver toxicity such as alterations of membrane fluidity and membrane-bound protein function. Observations also suggested that a possible role of cPLA 2 in

  9. Methods of Selenium Supplementation: Bioavailability and Determination of Selenium Compounds.

    Science.gov (United States)

    Bodnar, Malgorzata; Szczyglowska, Marzena; Konieczka, Piotr; Namiesnik, Jacek

    2016-01-01

    Selenium, a "dual-surface" element, maintains a very thin line between a level of necessity and harmfulness. Because of this, a deficiency or excess of this element in an organism is dangerous and causes health-related problems, both physically and mentally. The main source of selenium is a balanced diet, with a proper selection of meat and plant products. Meanwhile, the proper assimilation of selenium into these products depends on their bioavailability, bioaccessibility, and/or bioactivity of a given selenium compound. From the time when it was discovered that selenium and its compounds have a significant influence on metabolic processes and in many countries throughout the world, a low quantity of selenium was found in different parts of the environment, pressure was put upon an effective and fast method of supplementing the environment with the help of selenium. This work describes supplementation methods applied with the use of selenium, as well as new ideas for increasing the level of this element in various organisms. Based on the fact that selenium appears in the environment at trace levels, the determination of total amount of selenium or selenium speciation in a given sample demands the selection of appropriate measurement methods. These methods are most often comprised of a sample preparation technique and/or a separation technique as well as a detection system. The work presents information on the subject of analytical methods used for determining selenium and its compounds as well as examples in literature of their application.

  10. The influence of a selenium-chromium-lipid complex obtained from Chlorella vulgaris on the energy metabolism in rats with experimental diabetes

    Directory of Open Access Journals (Sweden)

    O. Y. Lukashiv

    2017-07-01

    Full Text Available One of the leading roles in treating diabetes mellitus belongs to chrome ions therapy (III, especially in the complex with selenium (IV. Currently selenium is obtained from unicellular algae, which contain biologically active substances and which are capable of accumulating exogenous microelements. By incubating unicellular algae Chlorella vulgaris Biej. in the conditions of aquaculture with sodium selenite (IV and chromium (III chloride, we obtained a biologically active lipid substance which contains selenium and chromium. The substance was tested for the impact on energy metabolism of animals exposed to experimentally induced diabetes mellitus. The diabetes was caused by modeling obesity of the animals with further injection of streptozotocin in the amount of 65 mg/kg and nicotinamide at the dose of 230 mg/kg. The rats were intragastrically injected with 1 ml of 1% starch solution which contained a selenium-chrome-lipid complex extracted from the Chlorella containing 0.6 µg of selenium, 1.05 µg of chrome and 0.5 mg of lipids for prophylactic, therapeutic and prophylactic-therapeutic purposes; the other group of rats for therapeutic purposes was injected with starch solution with the same composition of microelements in inorganic form – sodium selenite (IV and chromium chloride (III. This paper presents the results of our study of the impact of organic and inorganic compounds of chrome and selenium on the energetic metabolism of rats exposed to experimental diabetes mellitus. The analysis determined that in the rats’ organism, the selenium-chrome-lipid complex from the Chlorella improved the indicators of the energetic metabolism – in the group of rats which received it for therapeutic purposes, we observed an up to 7.5 fold increase in the activity of succinate dehydrogenase compared to the rats which did not receive therapeutic treatment. The increase in the activity of succinate dehydrogenase corresponded to the increase in the

  11. Disruption of behavior and brain metabolism in artificially reared rats.

    Science.gov (United States)

    Aguirre-Benítez, Elsa L; Porras, Mercedes G; Parra, Leticia; González-Ríos, Jacquelina; Garduño-Torres, Dafne F; Albores-García, Damaris; Avendaño, Arturo; Ávila-Rodríguez, Miguel A; Melo, Angel I; Jiménez-Estrada, Ismael; Mendoza-Garrido, Ma Eugenia; Toriz, César; Diaz, Daniel; Ibarra-Coronado, Elizabeth; Mendoza-Ángeles, Karina; Hernández-Falcón, Jesús

    2017-12-01

    Early adverse life stress has been associated to behavioral disorders that can manifest as inappropriate or aggressive responses to social challenges. In this study, we analyzed the effects of artificial rearing on the open field and burial behavioral tests and on GFAP, c-Fos immunoreactivity, and glucose metabolism measured in anxiety-related brain areas. Artificial rearing of male rats was performed by supplying artificial milk through a cheek cannula and tactile stimulation, mimicking the mother's licking to rat pups from the fourth postnatal day until weaning. Tactile stimulation was applied twice a day, at morning and at night, by means of a camel brush on the rat anogenital area. As compared to mother reared rats, greater aggressiveness, and boldness, stereotyped behavior (burial conduct) was observed in artificially reared rats which occurred in parallel to a reduction of GFAP immunoreactivity in somatosensory cortex, c-Fos immunoreactivity at the amygdala and primary somatosensory cortex, and lower metabolism in amygdala (as measured by 2-deoxi-2-[ 18 fluoro]-d-glucose uptake, assessed by microPET imaging). These results could suggest that tactile and/or chemical stimuli from the mother and littermates carry relevant information for the proper development of the central nervous system, particularly in brain areas involved with emotions and social relationships of the rat. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1413-1429, 2017. © 2017 Wiley Periodicals, Inc.

  12. Use of external metabolizing systems when testing for endocrine disruption in the T-screen assay

    International Nuclear Information System (INIS)

    Taxvig, Camilla; Olesen, Pelle Thonning; Nellemann, Christine

    2011-01-01

    Although, it is well-established that information on the metabolism of a substance is important in the evaluation of its toxic potential, there is limited experience with incorporating metabolic aspects into in vitro tests for endocrine disrupters. The aim of the current study was a) to study different in vitro systems for biotransformation of ten known endocrine disrupting chemicals (EDs): five azole fungicides, three parabens and 2 phthalates, b) to determine possible changes in the ability of the EDs to bind and activate the thyroid receptor (TR) in the in vitro T-screen assay after biotransformation and c) to investigate the endogenous metabolic capacity of the GH3 cells, the cell line used in the T-screen assay, which is a proliferation assay used for the in vitro detection of agonistic and antagonistic properties of compounds at the level of the TR. The two in vitro metabolizing systems tested the human liver S9 mix and the PCB-induced rat microsomes gave an almost complete metabolic transformation of the tested parabens and phthalates. No marked difference the effects in the T-screen assay was observed between the parent compounds and the effects of the tested metabolic extracts. The GH3 cells themselves significantly metabolized the two tested phthalates dimethyl phthalate (DMP) and diethyl phthalate (DEP). Overall the results and qualitative data from the current study show that an in vitro metabolizing system using liver S9 or microsomes could be a convenient method for the incorporation of metabolic and toxicokinetic aspects into in vitro testing for endocrine disrupting effects.

  13. Alleviation of glucose repression of maltose metabolism by MIG1 disruption in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klein, Christopher; Olsson, Lisbeth; Rønnow, B.

    1996-01-01

    The MIG1 gene was disrupted in a haploid laboratory strain (B224) and in an industrial polyploid strain (DGI 342) of Saccharomyces cerevisiae. The alleviation of glucose repression of the expression of MAL genes and alleviation of glucose control of maltose metabolism were investigated in batch...... cultivations on glucose-maltose mixtures. In the MIG1-disrupted haploid strain, glucose repression was partly alleviated; i.e., maltose metabolism was initiated at higher glucose concentrations than in the corresponding wild-type strain. In contrast, the polyploid Delta mig1 strain exhibited an even more...... stringent glucose control of maltose metabolism than the corresponding wild-type strain, which could be explained by a more rigid catabolite inactivation of maltose permease, affecting the uptake of maltose. Growth on the glucose-sucrose mixture showed that the polyploid Delta mig1 strain was relieved...

  14. Effects of sleep disruption and high fat intake on glucose metabolism in mice.

    Science.gov (United States)

    Ho, Jacqueline M; Barf, R Paulien; Opp, Mark R

    2016-06-01

    Poor sleep quality or quantity impairs glycemic control and increases risk of disease under chronic conditions. Recovery sleep may offset adverse metabolic outcomes of accumulated sleep debt, but the extent to which this occurs is unclear. We examined whether recovery sleep improves glucose metabolism in mice subjected to prolonged sleep disruption, and whether high fat intake during sleep disruption exacerbates glycemic control. Adult male C57BL/6J mice were subjected to 18-h sleep fragmentation daily for 9 days, followed by 1 day of recovery. During sleep disruption, one group of mice was fed a high-fat diet (HFD) while another group was fed standard laboratory chow. Insulin sensitivity and glucose tolerance were assessed by insulin and glucose tolerance testing at baseline, after 3 and 7 days of sleep disruption, and at the end of the protocol after 24h of undisturbed sleep opportunity (recovery). To characterize changes in sleep architecture that are associated with sleep debt and recovery, we quantified electroencephalogram (EEG) recordings during sleep fragmentation and recovery periods from an additional group of mice. We now report that 9 days of 18-h daily sleep fragmentation significantly reduces rapid eye movement sleep (REMS) and non-rapid eye movement sleep (NREMS). Mice respond with increases in REMS, but not NREMS, during the daily 6-h undisturbed sleep opportunity. However, both REMS and NREMS increase significantly during the 24-h recovery period. Although sleep disruption alone has no effect in this protocol, high fat feeding in combination with sleep disruption impairs glucose tolerance, effects that are reversed by recovery sleep. Insulin sensitivity modestly improves after 3 days of sleep fragmentation and after 24h of recovery, with significantly greater improvements in mice exposed to HFD during sleep disruption. Improvements in both glucose tolerance and insulin sensitivity are associated with NREMS rebound, raising the possibility that this

  15. Developmental programming: exposure to testosterone excess disrupts steroidal and metabolic environment in pregnant sheep.

    Science.gov (United States)

    Abi Salloum, B; Veiga-Lopez, A; Abbott, D H; Burant, C F; Padmanabhan, V

    2015-06-01

    Gestational exposure to excess T leads to intrauterine growth restriction, low birth weight, and adult metabolic/reproductive disorders in female sheep. We hypothesized that as early mediators of such disruptions, gestational T disrupts steroidal and metabolic homeostasis in both the mother and fetus by both androgenic and metabolic pathways. Maternal blood samples were measured weekly for levels of insulin, glucose, and progesterone from four groups of animals: control; gestational T (twice weekly im injections of 100 mg of T propionate from d 30 to d 90 of gestation); T plus an androgen antagonist, flutamide (15 mg/kg·d oral; T-Flutamide); and T plus the insulin sensitizer, rosiglitazone (0.11 mg/kg·d oral; T-Rosi) (n = 10-12/group). On day 90 of gestation, maternal and umbilical cord samples were collected after a 48-hour fast from a subset (n = 6/group) for the measurement of steroids, free fatty acids, amino acids, and acylcarnitines. Gestational T decreased maternal progesterone levels by 36.5% (P fetal estradiol were not prevented by either cotreatment. Gestational T disrupted associations of steroids with metabolites and progesterone with acylcarnitines, which was prevented either by androgen antagonist or insulin sensitizer cotreatment. These findings suggest a future combination of these treatments might be required to prevent alteration in maternal/fetal steroidal and metabolic milieu(s).

  16. Does circadian disruption play a role in the metabolic-hormonal link to delayed lactogenesis II?

    Directory of Open Access Journals (Sweden)

    Manjie eFu

    2015-02-01

    Full Text Available Breastfeeding improves maternal and child health. The American Academy of Pediatrics recommends exclusive breastfeeding for six months, with continued breastfeeding for at least one year. However, in the US, only 18.8% of infants are exclusively breastfed until six months of age. For mothers who initiate breastfeeding, the early postpartum period sets the stage for sustained breastfeeding. Mothers who experience breastfeeding problems in the early postpartum period are more likely to discontinue breastfeeding within two weeks. A major risk factor for shorter breastfeeding duration is delayed lactogenesis II (i.e. onset of milk coming in more than 72 h postpartum. Recent studies report a metabolic-hormonal link to delayed lactogenesis II. This is not surprising because around the time of birth the mother’s entire metabolism changes to direct nutrients to mammary glands. Circadian and metabolic systems are closely linked, and our rodent studies suggest circadian clocks coordinate hormonal and metabolic changes to support lactation. Molecular and environmental disruption of the circadian system decreases a dam’s ability to initiate lactation and negatively impacts milk production. Circadian and metabolic systems evolved to be functional and adaptive when lifestyles and environmental exposures were quite different from modern times. We now have artificial lights, longer work days, and increases in shift work. Disruption in the circadian system due to shift work, jet lag, sleep disorders and other modern life style choices are associated with metabolic disorders, obesity, and impaired reproduction. We hypothesize delayed lactogenesis II is related to disruption of the mother’s circadian system. Here we review literature that supports this hypothesis, and describe interventions that may help to increase breastfeeding success.

  17. Binary mixtures of mercury/ selenium, and lead/selenium

    African Journals Online (AJOL)

    Physiologically-based biokinetic models have been developed for predicting simultaneously the Absorption, Distribution, Metabolism and Elimination (ADME) properties of lead (Pb) and selenium (Se), and mercury (Hg) and selenium in a number of target tissues of humans. This was done for three population groups, ...

  18. Oral Gingival Cell Cigarette Smoke Exposure Induces Muscle Cell Metabolic Disruption

    Directory of Open Access Journals (Sweden)

    Andrea C. Baeder

    2016-01-01

    Full Text Available Cigarette smoke exposure compromises health through damaging multiple physiological systems, including disrupting metabolic function. The purpose of this study was to determine the role of oral gingiva in mediating the deleterious metabolic effects of cigarette smoke exposure on skeletal muscle metabolic function. Using an in vitro conditioned medium cell model, skeletal muscle cells were incubated with medium from gingival cells treated with normal medium or medium containing suspended cigarette smoke extract (CSE. Following incubation of muscle cells with gingival cell conditioned medium, muscle cell mitochondrial respiration and insulin signaling and action were determined as an indication of overall muscle metabolic health. Skeletal muscle cells incubated with conditioned medium of CSE-treated gingival cells had a profound reduction in mitochondrial respiration and respiratory control. Furthermore, skeletal muscle cells had a greatly reduced response in insulin-stimulated Akt phosphorylation and glycogen synthesis. Altogether, these results provide a novel perspective on the mechanism whereby cigarette smoke affects systemic metabolic function. In conclusion, we found that oral gingival cells treated with CSE create an altered milieu that is sufficient to both disrupted skeletal muscle cell mitochondrial function and insulin sensitivity.

  19. The interplay between sulphur and selenium metabolism influences the intracellular redox balance in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Mapelli, Valeria; Hillestrøm, Peter René; Patil, Kalpesh

    2012-01-01

    oxidative stress response is active when yeast actively metabolizes Se, and this response is linked to the generation of intracellular redox imbalance. The redox imbalance derives from a disproportionate ratio between the reduced and oxidized forms of glutathione and also from the influence of Se metabolism...

  20. Cancer Clocks Out for Lunch: Disruption of Circadian Rhythm and Metabolic Oscillation in Cancer.

    Science.gov (United States)

    Altman, Brian J

    2016-01-01

    Circadian rhythms are 24-h oscillations present in most eukaryotes and many prokaryotes that synchronize activity to the day-night cycle. They are an essential feature of organismal and cell physiology that coordinate many of the metabolic, biosynthetic, and signal transduction pathways studied in biology. The molecular mechanism of circadian rhythm is controlled both by signal transduction and gene transcription as well as by metabolic feedback. The role of circadian rhythm in cancer cell development and survival is still not well understood, but as will be discussed in this Review, accumulated research suggests that circadian rhythm may be altered or disrupted in many human cancers downstream of common oncogenic alterations. Thus, a complete understanding of the genetic and metabolic alterations in cancer must take potential circadian rhythm perturbations into account, as this disruption itself will influence how gene expression and metabolism are altered in the cancer cell compared to its non-transformed neighbor. It will be important to better understand these circadian changes in both normal and cancer cell physiology to potentially design treatment modalities to exploit this insight.

  1. Disruption of Skin Stem Cell Homeostasis following Transplacental Arsenicosis; Alleviation by Combined Intake of Selenium and Curcumin.

    Directory of Open Access Journals (Sweden)

    Shiv Poojan

    Full Text Available Of late, a consirable interest has grown in literature on early development of arsenicosis and untimely death in humans after exposure to iAs in drinking water in utero or during the childhood. The mechanism of this kind of intrauterine arsenic poisoning is not known; however it is often suggested to involve stem cells. We looked into this possibility by investigating in mice the influence of chronic in utero exposure to arsenical drinking water preliminarily on multipotent adult stem cell and progenitor cell counts at the beginning of neonatal age. We found that repeated intake of 42.5 or 85 ppm iAs in drinking water by pregnant BALB/c mice substantially changed the counts of EpASCs, the progenitor cells, and the differentiated cells in epidermis of their zero day old neonates. EpASCs counts decreased considerably and the differentiated/apoptosed cell counts increased extensively whereas the counts of progenitor cell displayed a biphasic effect. The observed trend of response was dose-dependent and statistically significant. These observations signified a disruption in stem cell homeostasis. The disorder was in parallel with changes in expression of biomarkers of stem cell and progenitor (TA cell besides changes in expression of pro-inflammatory and antioxidant molecules namely Nrf2, NFkB, TNF-α, and GSH. The biological monitoring of exposure to iAs and the ensuing transplacental toxicity was verifiable correspondingly by the increase in iAs burden in hair, kidney, skin, liver of nulliparous female mice and the onset of chromosomal aberrations in neonate bone marrow cells. The combined intake of selenite and curcumin in utero was found to prevent the disruption of homeostasis and associated biochemical changes to a great extent. The mechanism of prevention seemed possibly to involve (a curcumin and Keap-1 interaction, (b consequent escalated de novo GSH biosynthesis, and (c the resultant toxicant disposition. These observations are important

  2. Disruption of Skin Stem Cell Homeostasis following Transplacental Arsenicosis; Alleviation by Combined Intake of Selenium and Curcumin.

    Science.gov (United States)

    Poojan, Shiv; Kumar, Sushil; Verma, Vikas; Dhasmana, Anupam; Lohani, Mohtashim; Verma, Mukesh K

    2015-01-01

    Of late, a consirable interest has grown in literature on early development of arsenicosis and untimely death in humans after exposure to iAs in drinking water in utero or during the childhood. The mechanism of this kind of intrauterine arsenic poisoning is not known; however it is often suggested to involve stem cells. We looked into this possibility by investigating in mice the influence of chronic in utero exposure to arsenical drinking water preliminarily on multipotent adult stem cell and progenitor cell counts at the beginning of neonatal age. We found that repeated intake of 42.5 or 85 ppm iAs in drinking water by pregnant BALB/c mice substantially changed the counts of EpASCs, the progenitor cells, and the differentiated cells in epidermis of their zero day old neonates. EpASCs counts decreased considerably and the differentiated/apoptosed cell counts increased extensively whereas the counts of progenitor cell displayed a biphasic effect. The observed trend of response was dose-dependent and statistically significant. These observations signified a disruption in stem cell homeostasis. The disorder was in parallel with changes in expression of biomarkers of stem cell and progenitor (TA) cell besides changes in expression of pro-inflammatory and antioxidant molecules namely Nrf2, NFkB, TNF-α, and GSH. The biological monitoring of exposure to iAs and the ensuing transplacental toxicity was verifiable correspondingly by the increase in iAs burden in hair, kidney, skin, liver of nulliparous female mice and the onset of chromosomal aberrations in neonate bone marrow cells. The combined intake of selenite and curcumin in utero was found to prevent the disruption of homeostasis and associated biochemical changes to a great extent. The mechanism of prevention seemed possibly to involve (a) curcumin and Keap-1 interaction, (b) consequent escalated de novo GSH biosynthesis, and (c) the resultant toxicant disposition. These observations are important with respect to

  3. Endocrine disrupting chemicals in mixture and obesity, diabetes and related metabolic disorders

    Science.gov (United States)

    Le Magueresse-Battistoni, Brigitte; Labaronne, Emmanuel; Vidal, Hubert; Naville, Danielle

    2017-01-01

    Obesity and associated metabolic disorders represent a major societal challenge in health and quality of life with large psychological consequences in addition to physical disabilities. They are also one of the leading causes of morbidity and mortality. Although, different etiologic factors including excessive food intake and reduced physical activity have been well identified, they cannot explain the kinetics of epidemic evolution of obesity and diabetes with prevalence rates reaching pandemic proportions. Interestingly, convincing data have shown that environmental pollutants, specifically those endowed with endocrine disrupting activities, could contribute to the etiology of these multifactorial metabolic disorders. Within this review, we will recapitulate characteristics of endocrine disruption. We will demonstrate that metabolic disorders could originate from endocrine disruption with a particular focus on convincing data from the literature. Eventually, we will present how handling an original mouse model of chronic exposition to a mixture of pollutants allowed demonstrating that a mixture of pollutants each at doses beyond their active dose could induce substantial deleterious effects on several metabolic end-points. This proof-of-concept study, as well as other studies on mixtures of pollutants, stresses the needs for revisiting the current threshold model used in risk assessment which does not take into account potential effects of mixtures containing pollutants at environmental doses, e.g., the real life exposure. Certainly, more studies are necessary to better determine the nature of the chemicals to which humans are exposed and at which level, and their health impact. As well, research studies on substitute products are essential to identify harmless molecules. PMID:28588754

  4. Dynamic Metabolic Disruption in Rats Perinatally Exposed to Low Doses of Bisphenol-A.

    Directory of Open Access Journals (Sweden)

    Marie Tremblay-Franco

    Full Text Available Along with the well-established effects on fertility and fecundity, perinatal exposure to endocrine disrupting chemicals, and notably to xeno-estrogens, is strongly suspected of modulating general metabolism. The metabolism of a perinatally exposed individual may be durably altered leading to a higher susceptibility of developing metabolic disorders such as obesity and diabetes; however, experimental designs involving the long term study of these dynamic changes in the metabolome raise novel challenges. 1H-NMR-based metabolomics was applied to study the effects of bisphenol-A (BPA, 0; 0.25; 2.5, 25 and 250 μg/kg BW/day in rats exposed perinatally. Serum and liver samples of exposed animals were analyzed on days 21, 50, 90, 140 and 200 in order to explore whether maternal exposure to BPA alters metabolism. Partial Least Squares-Discriminant Analysis (PLS-DA was independently applied to each time point, demonstrating a significant pair-wise discrimination for liver as well as serum samples at all time-points, and highlighting unequivocal metabolic shifts in rats perinatally exposed to BPA, including those exposed to lower doses. In BPA exposed animals, metabolism of glucose, lactate and fatty acids was modified over time. To further explore dynamic variation, ANOVA-Simultaneous Component Analysis (A-SCA was used to separate data into blocks corresponding to the different sources of variation (Time, Dose and Time*Dose interaction. A-SCA enabled the demonstration of a dynamic, time/age dependent shift of serum metabolome throughout the rats' lifetimes. Variables responsible for the discrimination between groups clearly indicate that BPA modulates energy metabolism, and suggest alterations of neurotransmitter signaling, the latter finding being compatible with the neurodevelopmental effect of this xenoestrogen. In conclusion, long lasting metabolic effects of BPA could be characterized over 200 days, despite physiological (and thus metabolic changes

  5. Tributyltin disrupts feeding and energy metabolism in the goldfish (Carassius auratus).

    Science.gov (United States)

    Zhang, Jiliang; Sun, Ping; Yang, Fan; Kong, Tao; Zhang, Ruichen

    2016-06-01

    Tributyltin (TBT) can induce obesogen response. However, little is known about the adverse effects of TBT on food intake and energy metabolism. The present study was designed to investigate the effects of TBT, at environmental concentrations of 2.44 and 24.4 ng/L (1 and 10 ng/L as Sn), on feeding and energy metabolism in goldfish (Carassius auratus). After exposure for 54 d, TBT increased the weight gain and food intake in fish. The patterns of brain neuropeptide genes expression were in line with potential orexigenic effects, with increased expression of neuropeptide Y and apelin, and decreased expression of pro-opiomelanocortin, ghrelin, cocaine and amphetamine-regulated transcript, and corticotropin-releasing factor. Interestingly, the energy metabolism indicators (oxygen consumption, ammonia exertion and swimming activity) and the serum thyroid hormones were all significantly increased at the 2.44 ng/L TBT group in fish. However, no changes of energy metabolism indicators or a decrease of thyroid hormones was found at the 24.4 ng/L TBT group, which indicated a complex disrupting effect on metabolism of TBT. In short, TBT can alter feeding and energy metabolism in fish, which might promote the obesogenic responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Copper metabolism and its interactions with dietary iron, zinc, tin and selenium in rats

    NARCIS (Netherlands)

    Yu, S.

    1993-01-01

    This thesis describes various studies on copper metabolism and its interactions with selected dietary trace elements in rats. The rats were fed purified diets throughout. High intakes of iron or tin reduced copper concentrations in plasma, liver and kidneys. The dietary treatments also

  7. The relationship between circadian disruption and the development of metabolic syndrome and type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Karatsoreos IN

    2014-12-01

    Full Text Available Ilia N Karatsoreos Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA Abstract: Circadian (daily rhythms are pervasive in nature, and expressed in nearly every behavioral and physiological process. In mammals, circadian rhythms are regulated by the master brain clock in the suprachiasmatic nucleus of the hypothalamus that coordinates the activity of “peripheral” oscillators throughout the brain and body. While much progress has been made in understanding the basic functioning of the circadian clock at the level of genes, molecules, and cells, our understanding of how these clocks interact with complex systems is still in its infancy. Much recent work has focused on the role of circadian clocks in the etiology of disorders as diverse as cancer, diabetes, and obesity. Given the rapid rise in obesity, and the economic costs involved in treating its associated cardiometabolic disorders such as heart disease and diabetes mellitus, understanding the development of obesity and metabolic dysregulation is crucial. Significant epidemiological data indicate a role for circadian rhythms in metabolic disorders. Shift workers have a higher incidence of obesity and diabetes, and laboratory studies in humans show misaligning sleep and the circadian clock leads to hyperinsulinemia. In animal models, body-wide “clock gene” knockout mice are prone to obesity. Further, disrupting the circadian clock by manipulating the light–dark cycle can result in metabolic dysregulation and development of obesity. At the molecular level, elegant studies have shown that targeted disruption of the genetic circadian clock in the pancreas leads to diabetes, highlighting the fact that the circadian clock is directly coupled to metabolism at the cellular level. Keywords: glucose, metabolism, sleep, rhythms, obesity

  8. Maternal obesity disrupts circadian rhythms of clock and metabolic genes in the offspring heart and liver.

    Science.gov (United States)

    Wang, Danfeng; Chen, Siyu; Liu, Mei; Liu, Chang

    2015-06-01

    Early life nutritional adversity is tightly associated with the development of long-term metabolic disorders. Particularly, maternal obesity and high-fat diets cause high risk of obesity in the offspring. Those offspring are also prone to develop hyperinsulinemia, hepatic steatosis and cardiovascular diseases. However, the precise underlying mechanisms leading to these metabolic dysregulation in the offspring remain unclear. On the other hand, disruptions of diurnal circadian rhythms are known to impair metabolic homeostasis in various tissues including the heart and liver. Therefore, we investigated that whether maternal obesity perturbs the circadian expression rhythms of clock, metabolic and inflammatory genes in offspring heart and liver by using RT-qPCR and Western blotting analysis. Offspring from lean and obese dams were examined on postnatal day 17 and 35, when pups were nursed by their mothers or took food independently. On P17, genes examined in the heart either showed anti-phase oscillations (Cpt1b, Pparα, Per2) or had greater oscillation amplitudes (Bmal1, Tnf-α, Il-6). Such phase abnormalities of these genes were improved on P35, while defects in amplitudes still existed. In the liver of 17-day-old pups exposed to maternal obesity, the oscillation amplitudes of most rhythmic genes examined (except Bmal1) were strongly suppressed. On P35, the oscillations of circadian and inflammatory genes became more robust in the liver, while metabolic genes were still kept non-rhythmic. Maternal obesity also had a profound influence in the protein expression levels of examined genes in offspring heart and liver. Our observations indicate that the circadian clock undergoes nutritional programing, which may contribute to the alternations in energy metabolism associated with the development of metabolic disorders in early life and adulthood.

  9. Effects of varying the amounts of dietary calcium on selenium metabolism in dairy calves

    International Nuclear Information System (INIS)

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

    1987-01-01

    Influence of dietary Ca on Se metabolism was studied with 16 intact male Holstein calves averaging 86 kg. Calves were assigned randomly and fed one of four diets containing .17, .67, 1.31, and 2.35% Ca at 3% of their body weight for 4 wk. The diets contained .062 ppm Se and .34% P. Four days prior to the end of the experiment, calves were dosed orally with radioactive 75 Se. Dietary Ca had no significant effect on 75 Se absorption. There was a slight curvilinear relationship between apparent 75 Se absorption and dietary Ca intakes. Urinary excretion of 75 Se and stable Se tended to decrease with increasing dietary Ca, but differences were not significant. No significant differences were found in concentration of 75 Se in several tissues. Kidney and liver had the highest concentration with that in kidney being about four times that of liver. Apparent 75 Se absorption was decreased 10 to 6%, respectively, in calves fed extremely low and high amounts of Ca, compared with those receiving the requirement (.67% Ca). These small reductions along with a small R 2 suggest that dietary Ca probably is of little practical importance relative to Se metabolism in calves

  10. Mice lacking ANGPTL8 (Betatrophin) manifest disrupted triglyceride metabolism without impaired glucose homeostasis.

    Science.gov (United States)

    Wang, Yan; Quagliarini, Fabiana; Gusarova, Viktoria; Gromada, Jesper; Valenzuela, David M; Cohen, Jonathan C; Hobbs, Helen H

    2013-10-01

    Angiopoietin-like protein (ANGPTL)8 (alternatively called TD26, RIFL, Lipasin, and Betatrophin) is a newly recognized ANGPTL family member that has been implicated in both triglyceride (TG) and glucose metabolism. Hepatic overexpression of ANGPTL8 causes hypertriglyceridemia and increased insulin secretion. Here we examined the effects of inactivating Angptl8 on TG and glucose metabolism in mice. Angptl8 knockout (Angptl8(-/-)) mice gained weight more slowly than wild-type littermates due to a selective reduction in adipose tissue accretion. Plasma levels of TGs of the Angptl8(-/-) mice were similar to wild-type animals in the fasted state but paradoxically decreased after refeeding. The lower TG levels were associated with both a reduction in very low density lipoprotein secretion and an increase in lipoprotein lipase (LPL) activity. Despite the increase in LPL activity, the uptake of very low density lipoprotein-TG is markedly reduced in adipose tissue but preserved in hearts of fed Angptl8(-/-) mice. Taken together, these data indicate that ANGPTL8 plays a key role in the metabolic transition between fasting and refeeding; it is required to direct fatty acids to adipose tissue for storage in the fed state. Finally, glucose and insulin tolerance testing revealed no alterations in glucose homeostasis in mice fed either a chow or high fat diet. Thus, although absence of ANGPTL8 profoundly disrupts TG metabolism, we found no evidence that it is required for maintenance of glucose homeostasis.

  11. Circadian clock genes Per1 and Per2 regulate the response of metabolism-associated transcripts to sleep disruption.

    Directory of Open Access Journals (Sweden)

    Jana Husse

    Full Text Available Human and animal studies demonstrate that short sleep or poor sleep quality, e.g. in night shift workers, promote the development of obesity and diabetes. Effects of sleep disruption on glucose homeostasis and liver physiology are well documented. However, changes in adipokine levels after sleep disruption suggest that adipocytes might be another important peripheral target of sleep. Circadian clocks regulate metabolic homeostasis and clock disruption can result in obesity and the metabolic syndrome. The finding that sleep and clock disruption have very similar metabolic effects prompted us to ask whether the circadian clock machinery may mediate the metabolic consequences of sleep disruption. To test this we analyzed energy homeostasis and adipocyte transcriptome regulation in a mouse model of shift work, in which we prevented mice from sleeping during the first six hours of their normal inactive phase for five consecutive days (timed sleep restriction--TSR. We compared the effects of TSR between wild-type and Per1/2 double mutant mice with the prediction that the absence of a circadian clock in Per1/2 mutants would result in a blunted metabolic response to TSR. In wild-types, TSR induces significant transcriptional reprogramming of white adipose tissue, suggestive of increased lipogenesis, together with increased secretion of the adipokine leptin and increased food intake, hallmarks of obesity and associated leptin resistance. Some of these changes persist for at least one week after the end of TSR, indicating that even short episodes of sleep disruption can induce prolonged physiological impairments. In contrast, Per1/2 deficient mice show blunted effects of TSR on food intake, leptin levels and adipose transcription. We conclude that the absence of a functional clock in Per1/2 double mutants protects these mice from TSR-induced metabolic reprogramming, suggesting a role of the circadian timing system in regulating the physiological effects

  12. Effect of added dietary cobalt on metabolism and distribution of radioactive selenium and stable minerals

    International Nuclear Information System (INIS)

    Van Ryssen, J.B.J.; Miller, W.J.; Gentry, R.P.; Neathery, M.W.

    1987-01-01

    Retention of 75 Se following a single oral dose and stable Co, Cu, Zn, and Mg were determined in tissues of calves fed a diet containing 0, 10, or 40 ppm supplemental Co for 21 d. Concentrations of 75 Se in tissue were numerically higher with 10 ppm Co than with the other two diets, but the effect was significant only in small intestine tissues of calves fed 40 ppm Co. Dietary Co did not affect fecal 75 Se. Average total fecal 75 Se excretion was 53, 48, and 51% of the dose over 6 d in calves fed 0, 10, and 40 ppm added Co. Concentrations of Co in tissues increased with increased supplementation. Dietary Co did not significantly affect growth, feed intake, tissue Zn, tissue Cu, blood hemoglobin, packed cell volume, plasma alkaline phosphatase, or plasma glutamic oxaloacetic transaminase. Magnesium in heart and skeletal muscle was increased in calves fed 40 ppm Co. Although high amounts of added dietary Co had some influence on metabolism of Se, the magnitude and extent of the effects appeared to be too small to be of practical concern

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

    International Nuclear Information System (INIS)

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

    1987-01-01

    Metabolism of orally dosed 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 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, 75 Se absorption, blood concentration, and urine concentration were reduced by 26, 21, and 42%, respectively. Tissue 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 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

  14. Nickel Deficiency Disrupts Metabolism of Ureides, Amino Acids, and Organic Acids of Young Pecan Foliage[OA

    Science.gov (United States)

    Bai, Cheng; Reilly, Charles C.; Wood, Bruce W.

    2006-01-01

    The existence of nickel (Ni) deficiency is becoming increasingly apparent in crops, especially for ureide-transporting woody perennials, but its physiological role is poorly understood. We evaluated the concentrations of ureides, amino acids, and organic acids in photosynthetic foliar tissue from Ni-sufficient (Ni-S) versus Ni-deficient (Ni-D) pecan (Carya illinoinensis [Wangenh.] K. Koch). Foliage of Ni-D pecan seedlings exhibited metabolic disruption of nitrogen metabolism via ureide catabolism, amino acid metabolism, and ornithine cycle intermediates. Disruption of ureide catabolism in Ni-D foliage resulted in accumulation of xanthine, allantoic acid, ureidoglycolate, and citrulline, but total ureides, urea concentration, and urease activity were reduced. Disruption of amino acid metabolism in Ni-D foliage resulted in accumulation of glycine, valine, isoleucine, tyrosine, tryptophan, arginine, and total free amino acids, and lower concentrations of histidine and glutamic acid. Ni deficiency also disrupted the citric acid cycle, the second stage of respiration, where Ni-D foliage contained very low levels of citrate compared to Ni-S foliage. Disruption of carbon metabolism was also via accumulation of lactic and oxalic acids. The results indicate that mouse-ear, a key morphological symptom, is likely linked to the toxic accumulation of oxalic and lactic acids in the rapidly growing tips and margins of leaflets. Our results support the role of Ni as an essential plant nutrient element. The magnitude of metabolic disruption exhibited in Ni-D pecan is evidence of the existence of unidentified physiological roles for Ni in pecan. PMID:16415214

  15. Selenium essentials

    CERN Document Server

    Sams, Prashanth

    2015-01-01

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

  16. Neurochemical Metabolomics Reveals Disruption to Sphingolipid Metabolism Following Chronic Haloperidol Administration.

    Science.gov (United States)

    McClay, Joseph L; Vunck, Sarah A; Batman, Angela M; Crowley, James J; Vann, Robert E; Beardsley, Patrick M; van den Oord, Edwin J

    2015-09-01

    Haloperidol is an effective antipsychotic drug for treatment of schizophrenia, but prolonged use can lead to debilitating side effects. To better understand the effects of long-term administration, we measured global metabolic changes in mouse brain following 3 mg/kg/day haloperidol for 28 days. These conditions lead to movement-related side effects in mice akin to those observed in patients after prolonged use. Brain tissue was collected following microwave tissue fixation to arrest metabolism and extracted metabolites were assessed using both liquid and gas chromatography mass spectrometry (MS). Over 300 unique compounds were identified across MS platforms. Haloperidol was found to be present in all test samples and not in controls, indicating experimental validity. Twenty-one compounds differed significantly between test and control groups at the p < 0.05 level. Top compounds were robust to analytical method, also being identified via partial least squares discriminant analysis. Four compounds (sphinganine, N-acetylornithine, leucine and adenosine diphosphate) survived correction for multiple testing in a non-parametric analysis using false discovery rate threshold < 0.1. Pathway analysis of nominally significant compounds (p < 0.05) revealed significant findings for sphingolipid metabolism (p = 0.015) and protein biosynthesis (p = 0.024). Altered sphingolipid metabolism is suggestive of disruptions to myelin. This interpretation is supported by our observation of elevated N-acetyl-aspartyl-glutamate in the haloperidol-treated mice (p = 0.004), a marker previously associated with demyelination. This study further demonstrates the utility of murine neurochemical metabolomics as a method to advance understanding of CNS drug effects.

  17. Dark nights reverse metabolic disruption caused by dim light at night.

    Science.gov (United States)

    Fonken, L K; Weil, Z M; Nelson, R J

    2013-06-01

    The increasing prevalence of obesity and related metabolic disorders coincides with increasing exposure to light at night. Previous studies report that mice exposed to dim light at night (dLAN) develop symptoms of metabolic syndrome. This study investigated whether mice returned to dark nights after dLAN exposure recover metabolic function. Male Swiss-Webster mice were assigned to either: standard light-dark (LD) conditions for 8 weeks (LD/LD), dLAN for 8 weeks (dLAN/dLAN), LD for 4 weeks followed by 4 weeks of dLAN (LD/dLAN), and dLAN for 4 weeks followed by 4 weeks of LD (dLAN/LD). After 4 weeks in their respective lighting conditions both groups initially placed in dLAN increased body mass gain compared to LD mice. Half of the dLAN mice (dLAN/LD) were then transferred to LD and vice versa (LD/dLAN). Following the transfer dLAN/dLAN and LD/dLAN mice gained more weight than LD/LD and dLAN/LD mice. At the conclusion of the study dLAN/LD mice did not differ from LD/LD mice with respect to weight gain and had lower fat pad mass compared to dLAN/dLAN mice. Compared to all other groups dLAN/dLAN mice decreased glucose tolerance as indicated by an intraperitoneal glucose tolerance test at week 7, indicating that dLAN/LD mice recovered glucose metabolism. dLAN/dLAN mice also increased MAC1 mRNA expression in peripheral fat as compared to both LD/LD and dLAN/LD mice, suggesting peripheral inflammation is induced by dLAN, but not sustained after return to LD. These results suggest that re-exposure to dark nights ameliorates metabolic disruption caused by dLAN exposure. Copyright © 2013 The Obesity Society.

  18. Altered selenium status in Huntington's disease: neuroprotection by selenite in the N171-82Q mouse model.

    Science.gov (United States)

    Lu, Zhen; Marks, Eileen; Chen, Jianfang; Moline, Jenna; Barrows, Lorraine; Raisbeck, Merl; Volitakis, Irene; Cherny, Robert A; Chopra, Vanita; Bush, Ashley I; Hersch, Steven; Fox, Jonathan H

    2014-11-01

    Disruption of redox homeostasis is a prominent feature in the pathogenesis of Huntington's disease (HD). Selenium an essential element nutrient that modulates redox pathways and has been reported to provide protection against both acute neurotoxicity (e.g. methamphetamine) and chronic neurodegeneration (e.g. tauopathy) in mice. The objective of our study was to investigate the effect of sodium selenite, an inorganic form of selenium, on behavioral, brain degeneration and biochemical outcomes in the N171-82Q Huntington's disease mouse model. HD mice, which were supplemented with sodium selenite from 6 to 14 weeks of age, demonstrated increased motor endurance, decreased loss of brain weight, decreased mutant huntingtin aggregate burden and decreased brain oxidized glutathione levels. Biochemical studies revealed that selenite treatment reverted HD-associated changes in liver selenium and plasma glutathione in N171-82Q mice and had effects on brain selenoprotein transcript expression. Further, we found decreased brain selenium content in human autopsy brain. Taken together, we demonstrate a decreased selenium phenotype in human and mouse HD and additionally show some protective effects of selenite in N171-82Q HD mice. Modification of selenium metabolism results in beneficial effects in mouse HD and thus may represent a therapeutic strategy. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Does selenium supplementation affect thyroid function?

    DEFF Research Database (Denmark)

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

    2015-01-01

    OBJECTIVE: Selenium is present in the active site of proteins important for thyroid hormone synthesis and metabolism. The objective of this study is to investigate the effect of selenium supplementation in different doses on thyroid function, under conditions of suboptimal dietary selenium intake....... DESIGN: The Danish PREvention of Cancer by Intervention with SElenium pilot study (DK-PRECISE) is a randomized, double-blinded, placebo-controlled trial. A total of 491 males and females aged 60-74 years were randomized to 100 μg (n=124), 200 μg (n=122), or 300 μg (n=119) selenium-enriched yeast......=0.015), respectively, per 100 μg/day increase, with insignificant differences between 6 months and 5 years. No significant effects were found for FT3 and FT3:FT4 ratio. CONCLUSIONS: In euthyroid subjects, selenium supplementation minutely and dose-dependently affects thyroid function, when compared...

  20. Morphological, functional and metabolic imaging biomarkers: assessment of vascular-disrupting effect on rodent liver tumours

    International Nuclear Information System (INIS)

    Wang, Huaijun; Li, Junjie; Keyzer, Frederik De; Yu, Jie; Feng, Yuanbo; Marchal, Guy; Ni, Yicheng; Chen, Feng; Nuyts, Johan

    2010-01-01

    To evaluate effects of a vascular-disrupting agent on rodent tumour models. Twenty rats with liver rhabdomyosarcomas received ZD6126 intravenously at 20 mg/kg, and 10 vehicle-treated rats were used as controls. Multiple sequences, including diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MRI (DCE-MRI) with the microvascular permeability constant (K), were acquired at baseline, 1 h, 24 h and 48 h post-treatment by using 1.5-T MRI. [ 18 F]fluorodeoxyglucose micro-positron emission tomography ( 18 F-FDG μPET) was acquired pre- and post-treatment. The imaging biomarkers including tumour volume, enhancement ratio, necrosis ratio, apparent diffusion coefficient (ADC) and K from MRI, and maximal standardised uptake value (SUV max ) from FDG μPET were quantified and correlated with postmortem microangiography and histopathology. In the ZD6126-treated group, tumours grew slower with higher necrosis ratio at 48 h (P max dropped at 24 h (P < 0.01). Relative K of tumour versus liver at 48 h correlated with relative vascular density on microangiography (r = 0.93, P < 0.05). The imaging biomarkers allowed morphological, functional and metabolic quantifications of vascular shutdown, necrosis formation and tumour relapse shortly after treatment. A single dose of ZD6126 significantly diminished tumour blood supply and growth until 48 h post-treatment. (orig.)

  1. Endocrine Disrupting Chemical Induced "Pollution of Metabolic Pathways": A Case of Shifting Paradigms With Implications for Vascular Diseases.

    Science.gov (United States)

    Janardhanan, Rajiv

    2018-05-14

    The latter half of the twentieth century has witnessed a humongous spurt in the use of synthetic chemicals in a wide variety of industrial and agricultural applications are leading to niche specific perturbations affecting every trophic level of the ecosystems due to unmitigated environmental contamination. Despite the incremental usefulness of endocrine disrupting chemicals (EDCs) such as pesticides and plasticizers, their statutory impact on environmental health is assuming worrisome proportions. The EDCs can disrupt physiological homeostasis resulting in developmental and reproductive abnormalities. Both preclinical animal experiments, as well as epidemiological studies, have correlated EDC exposure with metabolic disorders such as metabolic syndrome, type 2 diabetes as well as cardiovascular health. Here we briefly review the statutory impact of EDCs on metabolic disruption as well as their impact on environmental health. Finally, difficulties pertaining to the categorization of EDC induced metabolic diseases as risk factors for global disease burden have been addressed taking into account the complexity of such interactions. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Organic and inorganic sources of zinc, copper and selenium in diets for dairy cows: intake, blood metabolic profile, milk yield and composition

    Directory of Open Access Journals (Sweden)

    Cristina Simões Cortinhas

    2012-06-01

    Full Text Available The present study was carried out with the objective of evaluating the effects of feeding dairy cows with organic or inorganic sources of zinc (Zn, copper (Cu and selenium (Se on blood concentrations of these minerals, blood metabolic profiles, nutrient intake and milk yield and composition. Nineteen Holstein cows were selected and randomly assigned to two groups for receiving organic (n = 9 or inorganic (n = 10 sources of Zn, Cu and Se from 60 days before the expected date of calving to 80 days of lactation. Samples of feed, orts and milk were collected for analysis. Body condition score (BCS was determined and blood samples were collected for analysis of Zn, Cu and Se concentrations, as well as for metabolic profile. Supplying organic or inorganic sources of Zn, Cu, and Se did not affect dry matter and nutrient intake, blood metabolic profile, milk yield and composition, plasma concentration of these minerals, and BCS or change the BCS in cows from 60 days before the expected date of calving to 80 days of lactation. An effect of time was observed on all feed intake variables, plasma concentrations of Zn and Se, milk yield, milk protein content, BCS and change in BCS.

  3. Selenium concentrations and enzyme activities of glutathione metabolism in wild long-tailed ducks and common eiders

    Science.gov (United States)

    Franson, J. Christian; Hoffman, David J.; Flint, Paul L.

    2011-01-01

    The relationships of selenium (Se) concentrations in whole blood with plasma activities of total glutathione peroxidase, Se-dependent glutathione peroxidase, and glutathione reductase were studied in long-tailed ducks (Clangula hyemalis) and common eiders (Somateria mollissima) sampled along the Beaufort Sea coast of Alaska, USA. Blood Se concentrations were >8 μg/g wet weight in both species. Linear regression revealed that the activities of total and Se-dependent glutathione peroxidase were significantly related to Se concentrations only in long-tailed ducks, raising the possibility that these birds were experiencing early oxidative stress.

  4. Aspirin suppresses the abnormal lipid metabolism in liver cancer cells via disrupting an NFκB-ACSL1 signaling.

    Science.gov (United States)

    Yang, Guang; Wang, Yuan; Feng, Jinyan; Liu, Yunxia; Wang, Tianjiao; Zhao, Man; Ye, Lihong; Zhang, Xiaodong

    2017-05-06

    Abnormal lipid metabolism is a hallmark of tumorigenesis. Hence, the alterations of metabolism enhance the development of hepatocellular carcinoma (HCC). Aspirin is able to inhibit the growth of cancers through targeting nuclear factor κB (NF-κB). However, the role of aspirin in disrupting abnormal lipid metabolism in HCC remains poorly understood. In this study, we report that aspirin can suppress the abnormal lipid metabolism of HCC cells through inhibiting acyl-CoA synthetase long-chain family member 1 (ACSL1), a lipid metabolism-related enzyme. Interestingly, oil red O staining showed that aspirin suppressed lipogenesis in HepG2 cells and Huh7 cells in a dose-dependent manner. In addition, aspirin attenuated the levels of triglyceride and cholesterol in the cells, respectively. Strikingly, we identified that aspirin was able to down-regulate ACSL1 at the levels of mRNA and protein. Moreover, we validated that aspirin decreased the nuclear levels of NF-κB in HepG2 cells. Mechanically, PDTC, an inhibitor of NF-κB, could down-regulate ACSL1 at the levels of mRNA and protein in the cells. Functionally, PDTC reduced the levels of lipid droplets, triglyceride and cholesterol in HepG2 cells. Thus, we conclude that aspirin suppresses the abnormal lipid metabolism in HCC cells via disrupting an NFκB-ACSL1 signaling. Our finding provides new insights into the mechanism by which aspirin inhibits abnormal lipid metabolism of HCC. Therapeutically, aspirin is potentially available for HCC through controlling abnormal lipid metabolism. Copyright © 2017. Published by Elsevier Inc.

  5. Selenium Utilization Strategy by Microalgae

    Directory of Open Access Journals (Sweden)

    Hiroya Araie

    2009-11-01

    Full Text Available The diversity of selenoproteins raises the question of why so many life forms require selenium. Selenoproteins are found in bacteria, archaea, and many eukaryotes. In photosynthetic microorganisms, the essential requirement for selenium has been reported in 33 species belonging to six phyla, although its biochemical significance is still unclear. According to genome databases, 20 species are defined as selenoprotein-producing organisms, including five photosynthetic organisms. In a marine coccolithophorid, Emiliania huxleyi (Haptophyta, we recently found unique characteristics of selenium utilization and novel selenoproteins using 75Se-tracer experiments. In E. huxleyi, selenite, not selenate, is the main substrate used and its uptake is driven by an ATP-dependent highaffinity, active transport system. Selenite is immediately metabolized to low-molecular mass compounds and partly converted to at least six selenoproteins, named EhSEP1–6. The most (EhSEP2 and second-most abundant selenoproteins (EhSEP1 are disulfide isomerase (PDI homologous protein and thioredoxin reductase (TR 1, respectively. Involvement of selenium in PDI is unique in this organism, while TR1 is also found in other organisms. In this review, we summarize physiological, biochemical, and molecular aspects of selenium utilization by microalgae and discuss their strategy of selenium utilization.

  6. Selenistasis: Epistatic Effects of Selenium on Cardiovascular Phenotype

    Directory of Open Access Journals (Sweden)

    Joseph Loscalzo

    2013-01-01

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

  7. Aspirin suppresses the abnormal lipid metabolism in liver cancer cells via disrupting an NFκB-ACSL1 signaling

    International Nuclear Information System (INIS)

    Yang, Guang; Wang, Yuan; Feng, Jinyan; Liu, Yunxia; Wang, Tianjiao; Zhao, Man; Ye, Lihong; Zhang, Xiaodong

    2017-01-01

    Abnormal lipid metabolism is a hallmark of tumorigenesis. Hence, the alterations of metabolism enhance the development of hepatocellular carcinoma (HCC). Aspirin is able to inhibit the growth of cancers through targeting nuclear factor κB (NF-κB). However, the role of aspirin in disrupting abnormal lipid metabolism in HCC remains poorly understood. In this study, we report that aspirin can suppress the abnormal lipid metabolism of HCC cells through inhibiting acyl-CoA synthetase long-chain family member 1 (ACSL1), a lipid metabolism-related enzyme. Interestingly, oil red O staining showed that aspirin suppressed lipogenesis in HepG2 cells and Huh7 cells in a dose-dependent manner. In addition, aspirin attenuated the levels of triglyceride and cholesterol in the cells, respectively. Strikingly, we identified that aspirin was able to down-regulate ACSL1 at the levels of mRNA and protein. Moreover, we validated that aspirin decreased the nuclear levels of NF-κB in HepG2 cells. Mechanically, PDTC, an inhibitor of NF-κB, could down-regulate ACSL1 at the levels of mRNA and protein in the cells. Functionally, PDTC reduced the levels of lipid droplets, triglyceride and cholesterol in HepG2 cells. Thus, we conclude that aspirin suppresses the abnormal lipid metabolism in HCC cells via disrupting an NFκB-ACSL1 signaling. Our finding provides new insights into the mechanism by which aspirin inhibits abnormal lipid metabolism of HCC. Therapeutically, aspirin is potentially available for HCC through controlling abnormal lipid metabolism. - Highlights: • Aspirin inhibits the levels of liquid droplets, triglyceride and cholesterol in HCC cells. • Aspirin is able to down-regulate ACSL1 in HCC cells. • NF-κB inhibitor PDTC can down-regulate ACSL1 and reduces lipogenesis in HCC cells. • Aspirin suppresses the abnormal lipid metabolism in HCC cells via disrupting an NFκB-ACSL1 signaling.

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

    Directory of Open Access Journals (Sweden)

    Beth S Zha

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

  9. Selenium biofortification

    Science.gov (United States)

    Plant foods are the major dietary sources of selenium (Se) in most countries around the world, followed by meats and seafood. For this reason, it is vital to increase Se uptake by plants and to produce crops with higher Se concentrations and bioavailability in their edible tissues. One of the most p...

  10. Thyroid hormones regulate selenoprotein expression and selenium status in mice.

    Directory of Open Access Journals (Sweden)

    Jens Mittag

    Full Text Available Impaired expression of selenium-containing proteins leads to perturbed thyroid hormone (TH levels, indicating the central importance of selenium for TH homeostasis. Moreover, critically ill patients with declining serum selenium develop a syndrome of low circulating TH and a central downregulation of the hypothalamus-pituitary-thyroid axis. This prompted us to test the reciprocal effect, i.e., if TH status would also regulate selenoprotein expression and selenium levels. To investigate the TH dependency of selenium metabolism, we analyzed mice expressing a mutant TH receptor α1 (TRα1+m that confers a receptor-mediated hypothyroidism. Serum selenium was reduced in these animals, which was a direct consequence of the mutant TRα1 and not related to their metabolic alterations. Accordingly, hyperthyroidism, genetically caused by the inactivation of TRβ or by oral TH treatment of adult mice, increased serum selenium levels in TRα1+m and controls, thus demonstrating a novel and specific role for TRα1 in selenium metabolism. Furthermore, TH affected the mRNA levels for several enzymes involved in selenoprotein biosynthesis as well as serum selenoprotein P concentrations and the expression of other antioxidative selenoproteins. Taken together, our results show that TH positively affects the serum selenium status and regulates the expression of several selenoproteins. This demonstrates that selenium and TH metabolism are interconnected through a feed-forward regulation, which can in part explain the rapid parallel downregulation of both systems in critical illness.

  11. Human exposure to endocrine disrupting compounds: Their role in reproductive systems, metabolic syndrome and breast cancer. A review.

    Science.gov (United States)

    Giulivo, Monica; Lopez de Alda, Miren; Capri, Ettore; Barceló, Damià

    2016-11-01

    Endocrine disrupting chemicals (EDCs) are released into the environment from different sources. They are mainly used in packaging industries, pesticides and food constituents. Clinical evidence, experimental models, and epidemiological studies suggest that EDCs have major risks for humans by targeting different organs and systems in the body (e.g. reproductive system, breast tissue, adipose tissue, pancreas, etc.). Due to the ubiquity of human exposure to these compounds the aim of this review is to describe the most recent data on the effects induced by phthalates, bisphenol A and parabens in a critical window of exposure: in utero, during pregnancy, infants, and children. The interactions and mechanisms of toxicity of EDCs in relation to human general health problems, especially those broadening the term of endocrine disruption to 'metabolic disruption', should be deeply investigated. These include endocrine disturbances, with particular reference to reproductive problems and breast, testicular and ovarian cancers, and metabolic diseases such as obesity or diabetes. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Exploring metabolic pathway disruption in the subchronic phencyclidine model of schizophrenia with the Generalized Singular Value Decomposition

    Directory of Open Access Journals (Sweden)

    Morris Brian J

    2011-05-01

    Full Text Available Abstract Background The quantification of experimentally-induced alterations in biological pathways remains a major challenge in systems biology. One example of this is the quantitative characterization of alterations in defined, established metabolic pathways from complex metabolomic data. At present, the disruption of a given metabolic pathway is inferred from metabolomic data by observing an alteration in the level of one or more individual metabolites present within that pathway. Not only is this approach open to subjectivity, as metabolites participate in multiple pathways, but it also ignores useful information available through the pairwise correlations between metabolites. This extra information may be incorporated using a higher-level approach that looks for alterations between a pair of correlation networks. In this way experimentally-induced alterations in metabolic pathways can be quantitatively defined by characterizing group differences in metabolite clustering. Taking this approach increases the objectivity of interpreting alterations in metabolic pathways from metabolomic data. Results We present and justify a new technique for comparing pairs of networks--in our case these networks are based on the same set of nodes and there are two distinct types of weighted edges. The algorithm is based on the Generalized Singular Value Decomposition (GSVD, which may be regarded as an extension of Principle Components Analysis to the case of two data sets. We show how the GSVD can be interpreted as a technique for reordering the two networks in order to reveal clusters that are exclusive to only one. Here we apply this algorithm to a new set of metabolomic data from the prefrontal cortex (PFC of a translational model relevant to schizophrenia, rats treated subchronically with the N-methyl-D-Aspartic acid (NMDA receptor antagonist phencyclidine (PCP. This provides us with a means to quantify which predefined metabolic pathways (Kyoto

  13. Selenium treatment differentially affects sulfur metabolism in high and low glucosinolate producing cultivars of broccoli (Brassica oleracea L.).

    Science.gov (United States)

    McKenzie, Marian J; Chen, Ronan K Y; Leung, Susanna; Joshi, Srishti; Rippon, Paula E; Joyce, Nigel I; McManus, Michael T

    2017-12-01

    The effect of selenium (Se) application on the sulfur (S)-rich glucosinolate (GSL)-containing plant, broccoli (Brassica oleracea L. var. italica) was examined with a view to producing germplasm with increased Se and GSL content for human health, and to understanding the influence of Se on the regulation of GSL production. Two cultivars differing in GSL content were compared. Increased Se application resulted in an increase in Se uptake in planta, but no significant change in total S or total GSL content in either cultivar. Also no significant change was observed in the activity of ATP sulfurylase (ATPS, EC 2.7.7.4) or O-acetylserine(thiol) lyase (OASTL, EC 2.5.1.47) with increased Se application. However, in the first investigation of APS kinase (APSK, EC 2.7.1.25) expression in response to Se fertilisation, an increase in transcript abundance of one variant of APS kinase 1 (BoAPSK1A) was observed in both cultivars, and an increase in BoAPSK2 transcript abundance was observed in the low GSL producing cultivar. A mechanism by which increased APSK transcription may provide a means of controlling the content of S-containing compounds, including GSLs, following Se uptake is proposed. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Impaired Homocysteine Transmethylation and Protein-Methyltransferase Activity Reduce Expression of Selenoprotein P: Implications for Obesity and Metabolic Syndrome

    Science.gov (United States)

    Obesity causes Metabolic Syndrome and Type-II Diabetes, disrupting hepatic function, methionine (Met)/homocysteine (Hcy) transmethylation and methyltransferase (PRMT) activities. Selenoprotein P (SEPP1), exported from the liver, is the predominate form of plasma selenium (Se) and the physiological S...

  15. Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria

    Directory of Open Access Journals (Sweden)

    Nelson L. Brock

    2013-05-01

    Full Text Available Members of the marine Roseobacter clade can degrade dimethylsulfoniopropionate (DMSP via competing pathways releasing either methanethiol (MeSH or dimethyl sulfide (DMS. Deuterium-labeled [2H6]DMSP and the synthetic DMSP analogue dimethyltelluriopropionate (DMTeP were used in feeding experiments with the Roseobacter clade members Phaeobacter gallaeciensis DSM 17395 and Ruegeria pomeroyi DSS-3, and their volatile metabolites were analyzed by closed-loop stripping and solid-phase microextraction coupled to GC–MS. Feeding experiments with [2H6]DMSP resulted in the incorporation of a deuterium label into MeSH and DMS. Knockout of relevant genes from the known DMSP demethylation pathway to MeSH showed in both species a residual production of [2H3]MeSH, suggesting that a second demethylation pathway is active. The role of DMSP degradation pathways for MeSH and DMS formation was further investigated by using the synthetic analogue DMTeP as a probe in feeding experiments with the wild-type strain and knockout mutants. Feeding of DMTeP to the R. pomeroyi knockout mutant resulted in a diminished, but not abolished production of demethylation pathway products. These results further corroborated the proposed second demethylation activity in R. pomeroyi. Isotopically labeled [2H3]methionine and 34SO42−, synthesized from elemental 34S8, were tested to identify alternative sulfur sources besides DMSP for the MeSH production in P. gallaeciensis. Methionine proved to be a viable sulfur source for the MeSH volatiles, whereas incorporation of labeling from sulfate was not observed. Moreover, the utilization of selenite and selenate salts by marine alphaproteobacteria for the production of methylated selenium volatiles was explored and resulted in the production of numerous methaneselenol-derived volatiles via reduction and methylation. The pathway of selenate/selenite reduction, however, proved to be strictly separated from sulfate reduction.

  16. [The role of selenium in endocrine system diseases].

    Science.gov (United States)

    Balázs, Csaba; Rácz, Károly

    2013-10-13

    Oxygen derived free radicals, generated by a number of cellular reactions, include superoxide anion, hydrogen peroxide and hydroxyl radicals. They exert their cytotoxic effects mainly via peroxidation of the cell membrane resulting in the loss of membrane integrity. The essential trace element, selenium exerts complex effects on the endocrine systems, partly due to its antioxidant capacity. Well-characterized selenoproteins include iodothyronine deiodinases, glutathione peroxidases and thioredoxin reductases involved in thyroid hormone metabolism and protection from oxidative damage. The value of selenium supplementation in autoimmune thyroid disorders has been investigated and most studies confirmed the beneficial effect of selenium supplementation in Hashimoto's and Graves's diseases. Recently, selenium proved to be effective in mild inflammatory orbitopathy. There are a number of reports about the effect of selenium in diabetes mellitus, but the data are controversial as both insulin-like and diabetes-inducing effects of selenium have been described. Selenium was successfully used in both female and male infertility of autoimmune origin.

  17. Selenium Homeostasis and Clustering of Cardiovascular Risk Factors: A Systematic Review.

    Science.gov (United States)

    Gharipour, Mojgan; Sadeghi, Masoumeh; Behmanesh, Mehrdad; Salehi, Mansour; Nezafati, Pouya; Gharpour, Amin

    2017-10-23

      Selenium is a trace element required for a range of cellular functions. It is widely used for the biosynthesis of the unique amino acid selenocysteine [Sec], which is a structural element of selenoproteins. This systematic review focused on the possible relation between selenium and metabolic risk factors. The literature was searched via PubMed, Scopus, ISI Web of Science, and Google Scholar. Searches were not restricted by time or language. Relevant studies were selected in three phases. After an initial quality assessment, two reviewers extracted all the relevant data, whereas the third reviewer checked their extracted data. All evidence came from experimental and laboratory studies. Selenoprotein P is the best indicator for selenium nutritional levels. In addition, high levels of selenium may increase the risk of metabolic syndrome while the lack of sufficient selenium may also promote metabolic syndrome. selenium supplementation in subjects with sufficient serum selenium levels has a contrary effect on blood pressure, LDL, and total cholesterol. According to the bioavailability of different types of selenium supplementation such as selenomethionine, selenite and selenium-yeast, it seems that the best nutritional type of selenium is selenium-yeast. Regarding obtained results of longitudinal studies and randomized controlled trials, selenium supplementation should not be recommended for primary or secondary cardio-metabolic risk prevention in populations with adequate selenium status.

  18. Glucose and maltose metabolism in MIG1-disrupted and MAL-constitutive strains of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klein, Christopher; Olsson, Lisbeth; Rønnow, B

    1997-01-01

    in a mixed glucose-maltose medium revealed that the MAL-constitutive strains were more alleviated than the single MIG1-disrupted transformant. While all transformants exhibited higher maximum specific growth rates (0.24-0.25 h(-1)) in glucose-maltose mixtures than the wild type strain (0.20 h(-1)), the MAL-constitutive...

  19. Altered steroid metabolism in several teleost species exposed to endocrine disrupting substances in refuse dump leachate

    NARCIS (Netherlands)

    Noaksson, E.; Linderoth, M.; Bosveld, A.T.C.; Balk, L.

    2003-01-01

    Endocrine disruption associated with reproductive failure has been reported previously in female perch (Perca fluviatilis) and roach (Rutilus rutilus) from Lake Molnbyggen in Sweden and in female brook trout (Salvelinus fontinalis) from Vadbäcken, a stream emptying into Molnbyggen. Both Molnbyggen

  20. The Molecular Mechanism of Alternative P450-Catalyzed Metabolism of Environmental Phenolic Endocrine-Disrupting Chemicals

    DEFF Research Database (Denmark)

    Ji, Li; Ji, Shujing; Wang, Chenchen

    2018-01-01

    Understanding the bioactivation mechanisms to predict toxic metabolites is critical for risk assessment of phenolic endocrine-disrupting chemicals (EDCs). One mechanism involves ipso-substitution, which may contribute to the total turnover of phenolic EDCs, yet the detailed mechanism and its rela...

  1. Disruption of TCA Cycle and Glutamate Metabolism Identified by Metabolomics in an In Vitro Model of Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Veyrat-Durebex, Charlotte; Corcia, Philippe; Piver, Eric; Devos, David; Dangoumau, Audrey; Gouel, Flore; Vourc'h, Patrick; Emond, Patrick; Laumonnier, Frédéric; Nadal-Desbarats, Lydie; Gordon, Paul H; Andres, Christian R; Blasco, Hélène

    2016-12-01

    This study aims to develop a cellular metabolomics model that reproduces the pathophysiological conditions found in amyotrophic lateral sclerosis in order to improve knowledge of disease physiology. We used a co-culture model combining the motor neuron-like cell line NSC-34 and the astrocyte clone C8-D1A, with each over-expressing wild-type or G93C mutant human SOD1, to examine amyotrophic lateral sclerosis (ALS) physiology. We focused on the effects of mutant human SOD1 as well as oxidative stress induced by menadione on intracellular metabolism using a metabolomics approach through gas chromatography coupled with mass spectrometry (GC-MS) analysis. Preliminary non-supervised analysis by Principal Component Analysis (PCA) revealed that cell type, genetic environment, and time of culture influenced the metabolomics profiles. Supervised analysis using orthogonal partial least squares discriminant analysis (OPLS-DA) on data from intracellular metabolomics profiles of SOD1 G93C co-cultures produced metabolites involved in glutamate metabolism and the tricarboxylic acid cycle (TCA) cycle. This study revealed the feasibility of using a metabolomics approach in a cellular model of ALS. We identified potential disruption of the TCA cycle and glutamate metabolism under oxidative stress, which is consistent with prior research in the disease. Analysis of metabolic alterations in an in vitro model is a novel approach to investigation of disease physiology.

  2. Deficiency of leptin receptor in myeloid cells disrupts hypothalamic metabolic circuits and causes body weight increase

    Directory of Open Access Journals (Sweden)

    Yuanqing Gao

    2018-01-01

    Conclusions: Myeloid cell leptin receptor deficient mice partially replicate the db/db phenotype. Leptin signaling in hypothalamic microglia is important for microglial function and a correct formation of the hypothalamic neuronal circuit regulating metabolism.

  3. High-Mobility Group Box 1 Disrupts Metabolic Function with Cigarette Smoke Exposure in a Ceramide-Dependent Manner

    Directory of Open Access Journals (Sweden)

    Oliver J. Taylor

    2017-05-01

    Full Text Available We have previously found that cigarette smoke disrupts metabolic function, in part, by increasing muscle ceramide accrual. To further our understanding of this, we sought to determine the role of the cytokine high-mobility group box 1 (HMGB1, which is increased with smoke exposure, in smoke-induced muscle metabolic perturbations. To test this theory, we determined HMGB1 from lungs of human smokers, as well as from lung cells from mice exposed to cigarette smoke. We also treated cells and mice directly with HMGB1, in the presence or absence of myriocin, an inhibitor of serine palmitoyltransferase, the rate-limiting enzyme in ceramide biosynthesis. Outcomes included assessments of insulin resistance and muscle mitochondrial function. HMGB1 was significantly increased in both human lungs and rodent alveolar macrophages. Further testing revealed that HMGB1 treatment elicited a widespread increase in ceramide species and reduction in myotube mitochondrial respiration, an increase in reactive oxygen species, and reduced insulin-stimulated Akt phosphorylation. Inhibition of ceramide biosynthesis with myriocin was protective. In mice, by comparing treatments of HMGB1 injections with or without myriocin, we found that HMGB1 injections resulted in increased muscle ceramides, especially C16 and C24, which were necessary for reduced muscle mitochondrial respiration and compromised insulin and glucose tolerance. In conclusion, HMGB1 may be a necessary intermediate in the ceramide-dependent metabolic consequences of cigarette smoke exposure.

  4. Selenium: its potential role in male infertility

    International Nuclear Information System (INIS)

    Oguntibeju, O.O.; Esterhuyse, J.S.; Truter, E.J.

    2009-01-01

    Currently, biomedical research is showing interest in the anti-oxidant activity of selenium. This could be due to compelling evidence that reported that oxidative damage to cells and cell membranes is one of the causative agents in the pathogenesis of many disease states including male infertility. Selenium is a trace element which may be found in soil, water and some foods and is considered to be an essential element which plays an active role in several metabolic pathways and is believed to perform several important roles in the human body. These roles include anti-oxidative activities at cellular level and participating in different enzyme systems. Selenium also serves as a vital component in the maintenance of muscle cell and red blood cell integrity, playing a role in the synthesis of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It has also been reported that selenium is essential in the detoxification of toxic metals in the human system, foetal respiration and energy transfer reactions as well as in the production of sperm cells. It is thought that male infertility can be the result of a selenium deficiency as the absence of selenium in the testicular tissues induces degeneration which results in the active impairment of sperm motility as the first indication of impending infertility. This review paper investigates the role of selenium in male infertility. (author)

  5. Metabolic disruptions induced by reduced ambulatory activity in free-living humans

    DEFF Research Database (Denmark)

    Thyfault, John P; Krogh-Madsen, Rikke

    2011-01-01

    Physical inactivity likely plays a role in the development of insulin resistance and obesity; however, direct evidence is minimal and mechanisms of action remain unknown. Studying metabolic outcomes that occur after transitioning from higher to lower levels of physical activity is the best tool t...

  6. Relative metabolic stability, but disrupted circadian cortisol secretion during the fasting month of Ramadan.

    Directory of Open Access Journals (Sweden)

    Suhad Bahijri

    Full Text Available BACKGROUND: Chronic feeding and sleep schedule disturbances are stressors that exert damaging effects on the organism. Practicing Muslims in Saudi Arabia go through strict Ramadan fasting from dawn till sunset for one month yearly. Modern era Ramadan practices in Saudi Arabia are associated with disturbed feeding and sleep patterns, namely abstaining from food and water and increasing daytime sleep, and staying awake and receiving food and water till dawn. HYPOTHESIS: Strict Ramadan practices in Saudi Arabia may influence metabolism, sleep and circadian cortisol secretion. PROTOCOL: Young, male Ramadan practitioners were evaluated before and two weeks into the Ramadan. Blood samples were collected at 9.00 am and 9.00 pm for measurements of metabolic parameters and cortisol. Saliva was collected serially during the day for cortisol determinations. RESULTS: Ramadan practitioners had relative metabolic stability or changes expected by the pattern of feeding. However, the cortisol circadian rhythm was abolished and circulating insulin levels and HOMA index were increased during this period. DISCUSSION: The flattening of the cortisol rhythm is typical of conditions associated with chronic stress or endogenous hypercortisolism and associated with insulin resistance. CONCLUSIONS: Modern Ramadan practices in Saudi Arabia are associated with evening hypercortisolism and increased insulin resistance. These changes might contribute to the high prevalence of chronic stress-related conditions, such as central obesity, hypertension, metabolic syndrome and diabetes mellitus type 2, and their cardiovascular sequelae observed in the Kingdom.

  7. Metabolic Disruption Early in Life is Associated With Latent Carcinogenic Activity of Dichloroacetic Acid in Mice

    Science.gov (United States)

    Early-life environmental factors can influence later-life susceptibility to cancer. Recent evidence suggests that metabolic pathways may mediate this type of latency effect. Previously, we reported that short-term exposure to dichloroacetic acid (DCA) increased liver cancer in mi...

  8. Disruption of quercetin metabolism by fungicide affects energy production in honey bees (Apis mellifera).

    Science.gov (United States)

    Mao, Wenfu; Schuler, Mary A; Berenbaum, May R

    2017-03-07

    Cytochrome P450 monooxygenases (P450) in the honey bee, Apis mellifera , detoxify phytochemicals in honey and pollen. The flavonol quercetin is found ubiquitously and abundantly in pollen and frequently at lower concentrations in honey. Worker jelly consumed during the first 3 d of larval development typically contains flavonols at very low levels, however. RNA-Seq analysis of gene expression in neonates reared for three days on diets with and without quercetin revealed that, in addition to up-regulating multiple detoxifying P450 genes, quercetin is a negative transcriptional regulator of mitochondrion-related nuclear genes and genes encoding subunits of complexes I, III, IV, and V in the oxidative phosphorylation pathway. Thus, a consequence of inefficient metabolism of this phytochemical may be compromised energy production. Several P450s metabolize quercetin in adult workers. Docking in silico of 121 pesticide contaminants of American hives into the active pocket of CYP9Q1, a broadly substrate-specific P450 with high quercetin-metabolizing activity, identified six triazole fungicides, all fungal P450 inhibitors, that dock in the catalytic site. In adults fed combinations of quercetin and the triazole myclobutanil, the expression of five of six mitochondrion-related nuclear genes was down-regulated. Midgut metabolism assays verified that adult bees consuming quercetin with myclobutanil metabolized less quercetin and produced less thoracic ATP, the energy source for flight muscles. Although fungicides lack acute toxicity, they may influence bee health by interfering with quercetin detoxification, thereby compromising mitochondrial regeneration and ATP production. Thus, agricultural use of triazole fungicides may put bees at risk of being unable to extract sufficient energy from their natural food.

  9. Bio-transformation of selenium in Se-enriched bacterial strains of Lactobacillus casei.

    Science.gov (United States)

    Kurek, Eliza; Ruszczyńska, Anna; Wojciechowski, Marcin; Łuciuk, Anna; Michalska-Kacymirow, Magdalena; Motyl, Ilona; Bulska, Ewa

    Selenium is an element of very great importance for the proper functioning of the human body, mainly due to its antioxidant properties. Selenium exhibits a preventive effect in the case of cardiovascular disease, the immune system, male infertility and inhibits the toxic action of other agents. Selenium is important for Hashimoto's disease. Intake of selenium in the diet slows the aging process. The biological and toxicological effects of selenium strongly depend on its chemical form. Some organisms for example: plant, yeast, are capable of metabolizing low bioavailable selenium compounds (inorganic selenium) into its high bioavailable forms (organic selenium). The aim of this study was to investigate the bio-transformation of selenium by Lactobacillus bacteria towards the characterisation of selenium metabolites. The speciation of selenium was evaluated by high performance liquid chromatography with inductively coupled plasma mass spectrometry detector. The extraction of selenium species from lyophilized bacteria was executed with water, the mixture of lipase and protease, as well as lisozyme and sodium dodecyl sulphate. All investigated bacteria strains cultivated in the presence of Na2SeO3 effectively uptake selenium. Surprisingly, none of the applied extraction media exhibited a strong power to release the majority of the uptaken selenium compounds. Thus a maximum of 10% of the selenium was extracted from bacteria exposed to the enzymes. However, it was found that Lactobacillus bacteria are able to metabolize inorganic ions of selenium (IV) into Se-methionine, Se-methyloselenocysteine and other unidentified forms. The study confirmed the ability of probiotic bacteria to biotransform inorganic selenium into its organic derivatives. Therefore, Se-enriched bacteria can be considered as an addition to the functional food. selenium speciation, extraction procedure, Lactobacillus casei bacteria, Lactic acid bacteria (LAB), HPLC ICP-MS, functional food.

  10. Granzyme B Disrupts Central Metabolism and Protein Synthesis in Bacteria to Promote an Immune Cell Death Program.

    Science.gov (United States)

    Dotiwala, Farokh; Sen Santara, Sumit; Binker-Cosen, Andres Ariel; Li, Bo; Chandrasekaran, Sriram; Lieberman, Judy

    2017-11-16

    Human cytotoxic lymphocytes kill intracellular microbes. The cytotoxic granule granzyme proteases released by cytotoxic lymphocytes trigger oxidative bacterial death by disrupting electron transport, generating superoxide anion and inactivating bacterial oxidative defenses. However, they also cause non-oxidative cell death because anaerobic bacteria are also killed. Here, we use differential proteomics to identify granzyme B substrates in three unrelated bacteria: Escherichia coli, Listeria monocytogenes, and Mycobacteria tuberculosis. Granzyme B cleaves a highly conserved set of proteins in all three bacteria, which function in vital biosynthetic and metabolic pathways that are critical for bacterial survival under diverse environmental conditions. Key proteins required for protein synthesis, folding, and degradation are also substrates, including multiple aminoacyl tRNA synthetases, ribosomal proteins, protein chaperones, and the Clp system. Because killer cells use a multipronged strategy to target vital pathways, bacteria may not easily become resistant to killer cell attack. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Aquatic Life Criterion - Selenium

    Science.gov (United States)

    Documents pertaining to the 2016 Acute and Chronic Ambient Aquatic Life Water Quality Criteria for Selenium (Freshwater). These documents include what the safe levels of Selenium are in water for the majority of species.

  12. Selenium content of mushrooms.

    Science.gov (United States)

    Stijve, T

    1977-07-29

    The selenium contents of 83 species of wild mushrooms were determined by oxygen combustion of the sample, followed by conversion of selenite to bromopiazselenol and final estimation by electron capture gas-liquid chromatography. Selenium concentration were found to range from 0.012-20.0 mg/kg dry weight. Selenium content was species-dependent. High concentrations were found in Agaricaceae and in certain Boletaceae of the genus Tubiporus, whereas in Russulaceae, Amanitaceae and Cantharellaceae selenium-rich species were absent or rare. Ascomycetes and all mushrooms growing on wood had a very low selenium content. The highest selenium concentrations (up to 20 ppm) were found in Boletus (Tubiporus) edulis, a most popular edible mushroom. Analyses of various parts of carpophores of B. edulis, Suillus luteus and Amanita muscaria indicate that in all three species the stalk contains less selenium than the fleshy part of the cap. In Boletus and Suillus the highest selenium content was found in the tubes.

  13. Dim Light at Night Disrupts Molecular Circadian Rhythms and Affects Metabolism

    Science.gov (United States)

    Fonken, Laura K.; Aubrecht, Taryn G.; Meléndez-Fernández, O. Hecmarie; Weil, Zachary M.; Nelson, Randy J.

    2014-01-01

    With the exception of high latitudes, life has evolved under bright days and dark nights. Most organisms have developed endogenously driven circadian rhythms which are synchronized to this daily light/dark cycle. In recent years, humans have shifted away from the naturally occurring solar light cycle in favor of artificial and sometimes irregular light schedules produced by electrical lighting. Exposure to unnatural light cycles is increasingly associated with obesity and metabolic syndrome; however the means by which environmental lighting alters metabolism are poorly understood. Thus, we exposed mice to nighttime light and investigated changes in the circadian system and body weight. Here we report that exposure to ecologically relevant levels of dim (5 lux) light at night attenuate core circadian clock rhythms in the SCN at both the gene and protein level. Moreover, circadian clock rhythms were perturbed in the liver by nighttime light exposure. Changes in the circadian clock were associated with temporal alterations in feeding behavior and increased weight gain. These results are significant because they provide mechanistic evidence for how mild changes in environmental lighting can alter circadian and metabolic function. PMID:23929553

  14. Selenium and Human Health

    Directory of Open Access Journals (Sweden)

    M Abedi

    2013-04-01

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

  15. Neurochemical metabolomics reveals disruption to sphingolipid metabolism following chronic haloperidol administration

    Science.gov (United States)

    McClay, Joseph L.; Vunck, Sarah A.; Batman, Angela M.; Crowley, James J.; Vann, Robert E.; Beardsley, Patrick M.; van den Oord, Edwin J.

    2015-01-01

    Haloperidol is an effective antipsychotic drug for treatment of schizophrenia, but prolonged use can lead to debilitating side effects. To better understand the effects of long-term administration, we measured global metabolic changes in mouse brain following 3 mg/kg/day haloperidol for 28 days. These conditions lead to movement-related side effects in mice akin to those observed in patients after prolonged use. Brain tissue was collected following microwave tissue fixation to arrest metabolism and extracted metabolites were assessed using both liquid and gas chromatography mass spectrometry (MS). Over 300 unique compounds were identified across MS platforms. Haloperidol was found to be present in all test samples and not in controls, indicating experimental validity. Twenty-one compounds differed significantly between test and control groups at the p haloperidol-treated mice (p = 0.004), a marker previously associated with demyelination. This study further demonstrates the utility of murine neurochemical metabolomics as a method to advance understanding of CNS drug effects. PMID:25850894

  16. The acetate switch of an intestinal pathogen disrupts host insulin signaling and lipid metabolism.

    Science.gov (United States)

    Hang, Saiyu; Purdy, Alexandra E; Robins, William P; Wang, Zhipeng; Mandal, Manabendra; Chang, Sarah; Mekalanos, John J; Watnick, Paula I

    2014-11-12

    Vibrio cholerae is lethal to the model host Drosophila melanogaster through mechanisms not solely attributable to cholera toxin. To examine additional virulence determinants, we performed a genetic screen in V. cholerae-infected Drosophila and identified the two-component system CrbRS. CrbRS controls transcriptional activation of acetyl-CoA synthase-1 (ACS-1) and thus regulates the acetate switch, in which bacteria transition from excretion to assimilation of environmental acetate. The resultant loss of intestinal acetate leads to deactivation of host insulin signaling and lipid accumulation in enterocytes, resulting in host lethality. These metabolic effects are not observed upon infection with ΔcrbS or Δacs1 V. cholerae mutants. Additionally, uninfected flies lacking intestinal commensals, which supply short chain fatty acids (SCFAs) such as acetate, also exhibit altered insulin signaling and intestinal steatosis, which is reversed upon acetate supplementation. Thus, acetate consumption by V. cholerae alters host metabolism, and dietary acetate supplementation may ameliorate some sequelae of cholera. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Vernonia DGATs can complement the disrupted oil and protein metabolism in epoxygenase-expressing soybean seeds.

    Science.gov (United States)

    Li, Runzhi; Yu, Keshun; Wu, Yongmei; Tateno, Mizuki; Hatanaka, Tomoko; Hildebrand, David F

    2012-01-01

    Plant oils can be useful chemical feedstocks such as a source of epoxy fatty acids. High seed-specific expression of a Stokesia laevis epoxygenase (SlEPX) in soybeans only results in 3-7% epoxide levels. SlEPX-transgenic soybean seeds also exhibited other phenotypic alterations, such as altered seed fatty acid profiles, reduced oil accumulation, and variable protein levels. SlEPX-transgenic seeds showed a 2-5% reduction in total oil content and protein levels of 30.9-51.4%. To address these pleiotrophic effects of SlEPX expression on other traits, transgenic soybeans were developed to co-express SlEPX and DGAT (diacylglycerol acyltransferase) genes (VgDGAT1 & 2) isolated from Vernonia galamensis, a high accumulator of epoxy fatty acids. These side effects of SlEPX expression were largely overcome in the DGAT co-expressing soybeans. Total oil and protein contents were restored to the levels in non-transgenic soybeans, indicating that both VgDGAT1 and VgDGAT2 could complement the disrupted phenotypes caused by over-expression of an epoxygenase in soybean seeds. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Cigarette smoke exposure alters [14C]arachidonic acid metabolism in aortas and platelets of rats fed various levels of selenium and vitamin E

    International Nuclear Information System (INIS)

    Valentovic, M.A.; Gairola, C.; Lubawy, W.C.

    1985-01-01

    Rats were placed on a basal diet supplemented with 0, 0.03, or 3 ppm selenium and 0 or 20 ppm vitamin E for 41-43 wk. Selenium deficiency decreased hepatic glutathione peroxidase activity and lowered both aortic prostacyclin (PGI2) and platelet thromboxane (TXA2) production compared to selenium- and vitamin E-supplemented animals. Vitamin E deficiency increased hepatic lipid peroxidation and decreased aortic PGI2 synthesis. Rats exposed daily for 31-32 wk to fresh smoke from a UK 2R1 reference cigarette had carboxyhemoglobin levels of 0.75 +/- 0.12 and 4.73 +/- 0.12% in sham- and smoke-exposed groups, respectively. Animals chronically exposed to cigarette smoke displayed a nearly twofold increase in pulmonary arylhydrocarbon hydroxylase activity. Smoke exposure produced a 26-33% decrease in aortic PGI2 synthesis compared to shams in the Se3E20, Se0.03E20, and Se3E0 groups. Smoking also increased platelet thromboxane 91% and 98% in the Se3E20 and Se3E0 groups compared to shams. It is concluded that cigarette-smoke exposure and selenium or vitamin E deficiency alter aortic PGI2 and platelet TXA2 production

  19. Mice lacking prostaglandin E receptor subtype 4 manifest disrupted lipid metabolism attributable to impaired triglyceride clearance.

    Science.gov (United States)

    Cai, Yin; Ying, Fan; Song, Erfei; Wang, Yu; Xu, Aimin; Vanhoutte, Paul M; Tang, Eva Hoi-Ching

    2015-12-01

    Upon high-fat feeding, prostaglandin E receptor subtype 4 (EP4)-knockout mice gain less body weight than their EP4(+/+) littermates. We investigated the cause of the lean phenotype. The mice showed a 68.8% reduction in weight gain with diminished fat mass that was not attributable to reduced food intake, fat malabsorption, or increased energy expenditure. Plasma triglycerides in the mice were elevated by 244.9%. The increase in plasma triglycerides was independent of changes in hepatic very low density lipoprotein (VLDL)-triglyceride production or intestinal chylomicron-triglyceride synthesis. However, VLDL-triglyceride clearance was drastically impaired in the EP4-knockout mice. The absence of EP4 in mice compromised the activation of lipoprotein lipase (LPL), the key enzyme responsible for trafficking of plasma triglycerides into peripheral tissues. Deficiency in EP4 reduced hepatic mRNA expression of the transcriptional factor cAMP response element binding protein H (by 36.8%) and LPL activators, including apolipoprotein (Apo)a5 (by 40.2%) and Apoc2 (by 61.3%). In summary, the lean phenotype of EP4-deficient mice resulted from reduction in adipose tissue and accretion of other peripheral organs caused by impaired triglyceride clearance. The findings identify a new metabolic dimension in the physiologic role played by endogenous EP4. © FASEB.

  20. Molecular neutron activation analysis of selenium metabolites in urine

    International Nuclear Information System (INIS)

    Blotcky, A.J.; Hansen, G.T.; Ebrahim, A.; Rack, E.P.

    1988-01-01

    Because of the biological importance of selenium in living biological systems, various analytical procedures have been developed for analysis of microquantities of elemental selenium, in urine, serum, and tissue. For urine selenium, these include atomic absorption spectrometry, solution absorption spectrometry, solution fluorescence spectrometry, volumetry, and neutron activation analysis. Of equal or greater importance is the determination of selenium metabolites present in urine for the purpose of describing the biological pathways for the metabolism of selenium in living organisms. While it is known from previous studies that trimethylselenonium ion (TMSe) is a major metabolite in urine, probably the result of reduction and methylation reaction, there are no definitive results in the literature indicating the nature or quantity of other selenium metabolic products in urine. Early techniques to measure TMSe levels in urine involved the use of the radiotracer 75 Se. Because of the long biological half-life of selenium and issues of radiation exposure, its use in humans has been limited. In this paper, the authors report the experimental procedure for the determination of total selenoamino acid concentration in urine and present total selenium values, and, where applicable, TMSe, SeO 2- 3 , and total selenoamino acid concentrations in the urine of normal and diseased subjects

  1. Selenium accumulation by plants

    Science.gov (United States)

    White, Philip J.

    2016-01-01

    Background Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate 100 mg Se kg–1 dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000–15 000 mg Se kg–1 dry matter and are called Se hyperaccumulators. Scope This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. Conclusions The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated into non-functional proteins, through the synthesis of less toxic Se metabilites. There is potential to breed or select crops with greater Se concentrations in their edible tissues, which

  2. Selenium in edible mushrooms.

    Science.gov (United States)

    Falandysz, Jerzy

    2008-01-01

    Selenium is vital to human health. This article is a compendium of virtually all the published data on total selenium concentrations, its distribution in fruitbody, bioconcentration factors, and chemical forms in wild-grown, cultivated, and selenium-enriched mushrooms worldwide. Of the 190 species reviewed (belonging to 21 families and 56 genera), most are considered edible, and a few selected data relate to inedible mushrooms. Most of edible mushroom species examined until now are selenium-poor (cesarea, A. campestris, A. edulis, A. macrosporus, and A. silvaticus. A particularly rich source of selenium could be obtained from selenium-enriched mushrooms that are cultivated on a substrate fortified with selenium (as inorganic salt or selenized-yeast). The Se-enriched Champignon Mushroom could contain up to 30 or 110 microg Se/g dw, while the Varnished Polypore (Ganoderma lucidum) could contain up to 72 microg Se/g dw. An increasingly growing database on chemical forms of selenium of mushrooms indicates that the seleno-compounds identified in carpophore include selenocysteine, selenomethionine, Se-methylselenocysteine, selenite, and several unidentified seleno-compounds; their proportions vary widely. Some aspects of environmental selenium occurrence and human body pharmacokinetics and nutritional needs will also be briefly discussed in this review.

  3. Disruption of the nitrogen regulatory gene AcareA in Acremonium chrysogenum leads to reduction of cephalosporin production and repression of nitrogen metabolism.

    Science.gov (United States)

    Li, Jinyang; Pan, Yuanyuan; Liu, Gang

    2013-12-01

    AcareA, encoding a homologue of the fungal nitrogen regulatory GATA zinc-finger proteins, was cloned from Acremonium chrysogenum. Gene disruption and genetic complementation revealed that AcareA was required for nitrogen metabolism and cephalosporin production. Disruption of AcareA resulted in growth defect in the medium using nitrate, uric acid and low concentration of ammonium, glutamine or urea as sole nitrogen source. Transcriptional analysis showed that the transcription of niaD/niiA was increased drastically when induced with nitrate in the wild-type and AcareA complemented strains but not in AcareA disruption mutant. Consistent with the reduction of cephalosporin production, the transcription of pcbAB, cefD2, cefEF and cefG encoding the enzymes for cephalosporin production was reduced in AcareA disruption mutant. Band shift assays showed that AcAREA bound to the promoter regions of niaD, niiA and the bidirectional promoter region of pcbAB-pcbC. Sequence analysis showed that all the AcAREA binding sites contain the consensus GATA elements. These results indicated that AcAREA plays an important role both in the regulation of nitrogen metabolism and cephalosporin production in A. chrysogenum. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Selenium in diet

    Science.gov (United States)

    ... how much of the mineral was in the soil where the plants grew. Brazil nuts are a very good source of selenium. Fish, shellfish , red meat, grains, eggs, chicken, liver, and garlic ... soil have higher levels of selenium. Brewer's yeast, wheat ...

  5. Selenium for preventing cancer

    Directory of Open Access Journals (Sweden)

    Gabriele Dennert

    Full Text Available BACKGROUND: Selenium is a trace element essential to humans. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers. OBJECTIVE: Two research questions were addressed in this review: What is the evidence for: 1. an aetiological relationship between selenium exposure and cancer risk in women and men?; 2. the efficacy of selenium supplementation for cancer prevention in women and men? SEARCH STRATEGY: We searched electronic databases and bibliographies of reviews and included publications. SELECTION CRITERIA: We included prospective observational studies to answer research question (a and randomised controlled trials (RCTs to answer research question (b. DATA COLLECTION AND ANALYSIS: We conducted random effects meta-analyses of epidemiological data when five or more studies were retrieved for a specific outcome. We made a narrative summary of data from RCTs. MAIN RESULTS: We included 49 prospective observational studies and six RCTs. In epidemiologic data, we found a reduced cancer incidence (summary odds ratio, OR, 0.69; 95% confidence interval, CI, 0.53 to 0.91 and mortality (OR 0.55, 95% CI 0.36 to 0.83 with higher selenium exposure. Cancer risk was more pronouncedly reduced in men (incidence: OR 0.66, 95% CI 0.42 to 1.05 than in women (incidence: OR 0.90, 95% CI 0.45 to 1.77. These findings have potential limitations due to study design, quality and heterogeneity of the data, which complicated the interpretation of the summary statistics. The RCTs found no protective efficacy of selenium yeast supplementation against non-melanoma skin cancer or L-selenomethionine supplementation against prostate cancer. Study results for the prevention of liver cancer with selenium supplements were inconsistent and studies had an unclear risk of bias. The results of the Nutritional Prevention of Cancer Trial (NPCT and SELECT raised concerns about possible harmful effects of selenium supplements. AUTHORS

  6. Selenium accumulation by plants.

    Science.gov (United States)

    White, Philip J

    2016-02-01

    Selenium (Se) is an essential mineral element for animals and humans, which they acquire largely from plants. The Se concentration in edible plants is determined by the Se phytoavailability in soils. Selenium is not an essential element for plants, but excessive Se can be toxic. Thus, soil Se phytoavailability determines the ecology of plants. Most plants cannot grow on seleniferous soils. Most plants that grow on seleniferous soils accumulate plant species have evolved tolerance to Se, and commonly accumulate tissue Se concentrations >100 mg Se kg(-1) dry matter. These plants are considered to be Se accumulators. Some species can even accumulate Se concentrations of 1000-15 000 mg Se kg(-1 )dry matter and are called Se hyperaccumulators. This article provides an overview of Se uptake, translocation and metabolism in plants and highlights the possible genetic basis of differences in these between and within plant species. The review focuses initially on adaptations allowing plants to tolerate large Se concentrations in their tissues and the evolutionary origin of species that hyperaccumulate Se. It then describes the variation in tissue Se concentrations between and within angiosperm species and identifies genes encoding enzymes limiting the rates of incorporation of Se into organic compounds and chromosomal loci that might enable the development of crops with greater Se concentrations in their edible portions. Finally, it discusses transgenic approaches enabling plants to tolerate greater Se concentrations in the rhizosphere and in their tissues. The trait of Se hyperaccumulation has evolved several times in separate angiosperm clades. The ability to tolerate large tissue Se concentrations is primarily related to the ability to divert Se away from the accumulation of selenocysteine and selenomethionine, which might be incorporated into non-functional proteins, through the synthesis of less toxic Se metabilites. There is potential to breed or select crops

  7. The necessity of selenium substitution in total parenteral nutrition and artificial alimentation.

    Science.gov (United States)

    Gramm, H J; Kopf, A; Brätter, P

    1995-03-01

    For the trace element selenium, in contrast to zinc, iron, copper, chromium, manganese and iodine, there is still no clear official recommendation with regard to routine substitution in artificial nutrition. An overview of the manifestations of selenium deficiency in humans during the period 1979-1995 shows that nutritive deficiencies are exclusively TPN-induced or the result of severe malnutrition. The pathology of TPN-induced selenium deficiency and the analytic assessment of selenium status are described. Patients undergoing long-term parenteral nutrition or suffering from an increased loss of intestinal secretions have to be characterized as being especially at risk for clinical selenium deficiency. The relationship of the serum selenium kinetics in pediatric and adult patients to the depletion of body compartments during the course of short-term and prolonged TPN is discussed. Because of the importance of the selenoproteins, the regularly occurring depletion during selenium-free TPN and the borderline supply of selenium in Germany the routine substitution of selenium in TPN is strongly recommended. The pharmaceutical industry should be encouraged to develop a trace element solution that includes selenium, so that the nutritive requirement of patients on TPN can be satisfied. Adequate intravenous dosage recommendations are based on maintenance of glutathione peroxidase homeostasis. The routine supplementation dosage may not meet the selenium requirements of intensive care patients under conditions of increased metabolic demands on their anti-oxidative system.

  8. Selenium and Its Supplementation in Cardiovascular Disease—What do We Know?

    Science.gov (United States)

    Benstoem, Carina; Goetzenich, Andreas; Kraemer, Sandra; Borosch, Sebastian; Manzanares, William; Hardy, Gil; Stoppe, Christian

    2015-01-01

    The trace element selenium is of high importance for many of the body’s regulatory and metabolic functions. Balanced selenium levels are essential, whereas dysregulation can cause harm. A rapidly increasing number of studies characterizes the wide range of selenium dependent functions in the human body and elucidates the complex and multiple physiological and pathophysiological interactions of selenium and selenoproteins. For the majority of selenium dependent enzymes, several biological functions have already been identified, like regulation of the inflammatory response, antioxidant properties and the proliferation/differentiation of immune cells. Although the potential role of selenium in the development and progression of cardiovascular disease has been investigated for decades, both observational and interventional studies of selenium supplementation remain inconclusive and are considered in this review. This review covers current knowledge of the role of selenium and selenoproteins in the human body and its functional role in the cardiovascular system. The relationships between selenium intake/status and various health outcomes, in particular cardiomyopathy, myocardial ischemia/infarction and reperfusion injury are reviewed. We describe, in depth, selenium as a biomarker in coronary heart disease and highlight the significance of selenium supplementation for patients undergoing cardiac surgery. PMID:25923656

  9. Selenium and Its Supplementation in Cardiovascular Disease—What do We Know?

    Directory of Open Access Journals (Sweden)

    Carina Benstoem

    2015-04-01

    Full Text Available The trace element selenium is of high importance for many of the body’s regulatory and metabolic functions. Balanced selenium levels are essential, whereas dysregulation can cause harm. A rapidly increasing number of studies characterizes the wide range of selenium dependent functions in the human body and elucidates the complex and multiple physiological and pathophysiological interactions of selenium and selenoproteins. For the majority of selenium dependent enzymes, several biological functions have already been identified, like regulation of the inflammatory response, antioxidant properties and the proliferation/differentiation of immune cells. Although the potential role of selenium in the development and progression of cardiovascular disease has been investigated for decades, both observational and interventional studies of selenium supplementation remain inconclusive and are considered in this review. This review covers current knowledge of the role of selenium and selenoproteins in the human body and its functional role in the cardiovascular system. The relationships between selenium intake/status and various health outcomes, in particular cardiomyopathy, myocardial ischemia/infarction and reperfusion injury are reviewed. We describe, in depth, selenium as a biomarker in coronary heart disease and highlight the significance of selenium supplementation for patients undergoing cardiac surgery.

  10. Why Nature Chose Selenium.

    Science.gov (United States)

    Reich, Hans J; Hondal, Robert J

    2016-04-15

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

  11. 1,25(OH)2D3 disrupts glucose metabolism in prostate cancer cells leading to a truncation of the TCA cycle and inhibition of TXNIP expression.

    Science.gov (United States)

    Abu El Maaty, Mohamed A; Alborzinia, Hamed; Khan, Shehryar J; Büttner, Michael; Wölfl, Stefan

    2017-10-01

    Prostate cell metabolism exhibits distinct profiles pre- and post-malignancy. The malignant metabolic shift converts prostate cells from "citrate-producing" to "citrate-oxidizing" cells, thereby enhancing glucose metabolism, a phenotype that contrasts classical tumoral Warburg metabolism. An on-line biosensor chip system (BIONAS 2500) was used to monitor metabolic changes (glycolysis and respiration) in response to the putative anti-cancer nutraceutical 1,25-dihydroxyvitamin D 3 [1,25(OH) 2 D 3 ], in different prostate cancer (PCa) cell lines (LNCaP, VCaP, DU145 and PC3). LNCaP cells exhibited profound metabolic responsiveness to the treatment and thus extensive analysis of metabolism-modulating effects of 1,25(OH) 2 D 3 were performed, including mRNA expression analysis of key metabolic genes (e.g. GLUT1 and PDHK1), analysis of TCA cycle metabolites, glucose uptake/consumption measurements, ATP production, and mitochondrial biogenesis/activity. Altogether, data demonstrate a vivid disruption of glucose metabolism by 1,25(OH) 2 D 3 , illustrated by a decreased glucose uptake and an accumulation of citrate/isocitrate due to TCA cycle truncation. Depletion of glycolytic intermediates led to a consistent decrease in TXNIP expression in response to 1,25(OH) 2 D 3 , an effect that coincided with the activation of AMPK signaling and a reduction in c-MYC expression. Reduction in TXNIP levels in response to 1,25(OH) 2 D 3 was rescued by an AMPK signaling inhibitor and mimicked by a MYC inhibitor highlighting the possible involvement of both pathways in mediating 1,25(OH) 2 D 3 's metabolic effects in PCa cells. Furthermore, pharmacological and genetic modulation of the androgen receptor showed similar and disparate effects on metabolic parameters compared to 1,25(OH) 2 D 3 treatment, highlighting the AR-independent nature of 1,25(OH) 2 D 3 's metabolism-modulating effects. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Selenium in Graves' disease

    Directory of Open Access Journals (Sweden)

    Jadwiga Kryczyk

    2013-05-01

    Full Text Available The aim of this study was to present the current state of knowledge of the role of selenium in Graves’ disease. Recently, in the pathogenesis and course of this autoimmune disease, more attention has been paid to the relationship between oxidative stress and the antioxidant system, where selenium compounds play an important role. The thyroid is the organ with the highest selenium concentration in the human body. Selenium compounds, having antioxidant properties, protect thyrocytes against the destructive effects of reactive oxygen species (ROS, which are generated during the synthesis of thyroid hormones. Therefore, strengthening the body’s defense mechanisms, which protect against the formation and activity of ROS during medical treatment of Graves’ disease patients, may be an effective adjuvant in commonly used methods of therapy.

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

    Directory of Open Access Journals (Sweden)

    Mihaela Monica Stanciu-Burileanu

    2010-01-01

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

  14. CIRCADIAN REGULATION METABOLIC SIGNALING MECHANISMS OF HUMAN BREAST CANCER GROWTH BY THE NOCTURNAL MELATONIN SIGNAL AND THE CONSEQUENCES OF ITS DISRUPTION BY LIGHT AT NIGHT

    Science.gov (United States)

    Blask, David E.; Hill, Steven M.; Dauchy, Robert T.; Xiang, Shulin; Yuan, Lin; Duplessis, Tamika; Mao, Lulu; Dauchy, Erin; Sauer, Leonard A.

    2011-01-01

    This review article discusses recent work on the melatonin-mediated circadian regulation and integration of molecular, dietary and metabolic signaling mechanisms involved in human breast cancer growth and the consequences of circadian disruption by exposure to light-at-night (LAN). The antiproliferative effects of the circadian melatonin signal are mediated through a major mechanism involving the activation of MT1 melatonin receptors expressed in human breast cancer cell lines and xenografts. In estrogen receptor (ERα+) human breast cancer cells, melatonin suppresses both ERα mRNA expression and estrogen-induced transcriptional activity of the ERα via MT1-induced activation of Gαi2 signaling and reduction of cAMP levels. Melatonin also regulates the transactivation of additional members of the steroid hormone/nuclear receptor super-family, enzymes involved in estrogen metabolism, expression/activation of telomerase and the expression of core clock and clock-related genes. The anti-invasive/anti-metastatic actions of melatonin involve the blockade of p38 phosphorylation and the expression of matrix metalloproteinases. Melatonin also inhibits the growth of human breast cancer xenografts via another critical pathway involving MT1-mediated suppression of cAMP leading to blockade of linoleic acid (LA) uptake and its metabolism to the mitogenic signaling molecule 13-hydroxyoctadecadienoic acid (13-HODE). Down-regulation of 13-HODE reduces the activation of growth factor pathways supporting cell proliferation and survival. Experimental evidence in rats and humans indicating that LAN-induced circadian disruption of the nocturnal melatonin signal activates human breast cancer growth, metabolism and signaling provides the strongest mechanistic support, thus far, for population and ecological studies demonstrating elevated breast cancer risk in night shift workers and other individuals increasingly exposed to LAN. PMID:21605163

  15. Disruption of Mouse Cytochrome P450 4f14 (Cyp4f14 Gene) Causes Severe Perturbations in Vitamin E Metabolism*

    Science.gov (United States)

    Bardowell, Sabrina A.; Duan, Faping; Manor, Danny; Swanson, Joy E.; Parker, Robert S.

    2012-01-01

    Vitamin E is a family of naturally occurring and structurally related lipophilic antioxidants, one of which, α-tocopherol (α-TOH), selectively accumulates in vertebrate tissues. The ω-hydroxylase cytochrome P450–4F2 (CYP4F2) is the only human enzyme shown to metabolize vitamin E. Using cDNA cloning, cell culture expression, and activity assays, we identified Cyp4f14 as a functional murine ortholog of CYP4F2. We then investigated the effect of Cyp4f14 deletion on vitamin E metabolism and status in vivo. Cyp4f14-null mice exhibited substrate-specific reductions in liver microsomal vitamin E-ω-hydroxylase activity ranging from 93% (γ-TOH) to 48% (γ-tocotrienol). In vivo data obtained from metabolic cage studies showed whole-body reductions in metabolism of γ-TOH of 90% and of 68% for δ- and α-TOH. This metabolic deficit in Cyp4f14−/− mice was partially offset by increased fecal excretion of nonmetabolized tocopherols and of novel ω-1- and ω-2-hydroxytocopherols. 12′-OH-γ-TOH represented 41% of whole-body production of γ-TOH metabolites in Cyp4f14−/− mice fed a soybean oil diet. Despite these counterbalancing mechanisms, Cyp4f14-null mice fed this diet for 6 weeks hyper-accumulated γ-TOH (2-fold increase over wild-type littermates) in all tissues and appeared normal. We conclude that CYP4F14 is the major but not the only vitamin E-ω-hydroxylase in mice. Its disruption significantly impairs whole-body vitamin E metabolism and alters the widely conserved phenotype of preferential tissue deposition of α-TOH. This model animal and its derivatives will be valuable in determining the biological actions of specific tocopherols and tocotrienols in vivo. PMID:22665481

  16. Selenium toxicity: cause and effects in aquatic birds

    Science.gov (United States)

    Spallholz, J.E.; Hoffman, D.J.

    2002-01-01

    There are several manners in which selenium may express its toxicity: (1) an important mechanism appears to involve the formation of CH3Se- which either enters a redox cycle and generates superoxide and oxidative stress, or forms free radicals that bind to and inhibit important enzymes and proteins. (2) Excess selenium as selenocysteine results in inhibition of selenium methylation metabolism. As a consequence, concentrations of hydrogen selenide, an intermediate metabolite, accumulate in animals and are hepatotoxic, possibly causing other selenium-related adverse effects. (3) It is also possible that the presence of excess selenium analogs of sulfur-containing enzymes and structural proteins play a role in avian teratogenesis. l-selenomethionine is the most likely major dietary form of selenium encountered by aquatic birds, with lesser amounts of l-selenocysteine ingested from aquatic animal foods. The literature is suggestive that l-selenomethionine is not any more toxic to adult birds than other animals. l-Selenomethionine accumulates in tissue protein of adult birds and in the protein of egg white as would be expected to occur in animals. There is no suggestion from the literature that the levels of l-selenomethionine that would be expected to accumulate in eggs in the absence of environmental concentration of selenium pose harm to the developing embryo. For several species of aquatic birds, levels of Se as selenomethionine in the egg above 3 ppm on a wet weight basis result in reduced hatchability and deformed embryos. The toxicity of l-selenomethionine injected directly into eggs is greater than that found from the entry of l-selenomethionine into the egg from the normal adult diet. This suggests that there is unusual if not abnormal metabolism of l-selenomethionine in the embryo not seen when l-selenomethionine is present in egg white protein where it likely serves as a source of selenium for glutathione peroxidase synthesis in the developing aquatic chick.

  17. Redox-Active Selenium Compounds—From Toxicity and Cell Death to Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Sougat Misra

    2015-05-01

    Full Text Available Selenium is generally known as an antioxidant due to its presence in selenoproteins as selenocysteine, but it is also toxic. The toxic effects of selenium are, however, strictly concentration and chemical species dependent. One class of selenium compounds is a potent inhibitor of cell growth with remarkable tumor specificity. These redox active compounds are pro-oxidative and highly cytotoxic to tumor cells and are promising candidates to be used in chemotherapy against cancer. Herein we elaborate upon the major forms of dietary selenium compounds, their metabolic pathways, and their antioxidant and pro-oxidant potentials with emphasis on cytotoxic mechanisms. Relative cytotoxicity of inorganic selenite and organic selenocystine compounds to different cancer cells are presented as evidence to our perspective. Furthermore, new novel classes of selenium compounds specifically designed to target tumor cells are presented and the potential of selenium in modern oncology is extensively discussed.

  18. Biological selenium removal from wastewaters

    NARCIS (Netherlands)

    Lenz, M.

    2008-01-01

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

  19. Selenium in human mammary carcinogenesis

    DEFF Research Database (Denmark)

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

    1991-01-01

    /l and TNM stage II 76 +/- 13 micrograms selenium/l), indicating disease-mediated changes. The evaluation of selenium as a risk indicator in human breast cancer was therefore restricted to TNM stage I patients (n = 36). Multiple logistic regression analyses including variables associated with selenium levels...

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

    Science.gov (United States)

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

    2013-01-01

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

  1. Selenium for preventing cancer.

    Science.gov (United States)

    Vinceti, Marco; Filippini, Tommaso; Del Giovane, Cinzia; Dennert, Gabriele; Zwahlen, Marcel; Brinkman, Maree; Zeegers, Maurice Pa; Horneber, Markus; D'Amico, Roberto; Crespi, Catherine M

    2018-01-29

    This review is the third update of the Cochrane review "Selenium for preventing cancer". Selenium is a naturally occurring element with both nutritional and toxicological properties. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancer. To gather and present evidence needed to address two research questions:1. What is the aetiological relationship between selenium exposure and cancer risk in humans?2. Describe the efficacy of selenium supplementation for cancer prevention in humans. We updated electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE (Ovid, 2013 to January 2017, week 4), and Embase (2013 to 2017, week 6), as well as searches of clinical trial registries. We included randomised controlled trials (RCTs) and longitudinal observational studies that enrolled adult participants. We performed random-effects (RE) meta-analyses when two or more RCTs were available for a specific outcome. We conducted RE meta-analyses when five or more observational studies were available for a specific outcome. We assessed risk of bias in RCTs and in observational studies using Cochrane's risk assessment tool and the Newcastle-Ottawa Scale, respectively. We considered in the primary analysis data pooled from RCTs with low risk of bias. We assessed the certainty of evidence by using the GRADE approach. We included 83 studies in this updated review: two additional RCTs (10 in total) and a few additional trial reports for previously included studies. RCTs involved 27,232 participants allocated to either selenium supplements or placebo. For analyses of RCTs with low risk of bias, the summary risk ratio (RR) for any cancer incidence was 1.01 (95% confidence interval (CI) 0.93 to 1.10; 3 studies, 19,475 participants; high-certainty evidence). The RR for estimated cancer mortality was 1.02 (95% CI 0.80 to 1.30; 1 study, 17,444 participants). For the most frequently

  2. Selenium Supranutrition: Are the Potential Benefits of Chemoprevention Outweighed by the Promotion of Diabetes and Insulin Resistance?

    Science.gov (United States)

    Rocourt, Caroline R. B.; Cheng, Wen-Hsing

    2013-01-01

    Selenium was considered a toxin until 1957, when this mineral was shown to be essential in the prevention of necrotic liver damage in rats. The hypothesis of selenium chemoprevention is principally formulated by the observations that cancer incidence is inversely associated with selenium status. However, recent clinical and epidemiological studies demonstrate a role for some selenoproteins in exacerbating or promoting other disease states, specifically type 2 diabetes, although other data support a role of selenium in stimulating insulin sensitivity. Therefore, it is clear that our understanding in the role of selenium in glucose metabolism and chemoprevention is inadequate and incomplete. Research exploring the role of selenium in individual healthcare is of upmost importance and possibly will help explain how selenium is a double-edged sword in the pathologies of chronic diseases. PMID:23603996

  3. High fat diet and in utero exposure to maternal obesity disrupts circadian rhythm and leads to metabolic programming of liver in rat offspring.

    Directory of Open Access Journals (Sweden)

    Sarah J Borengasser

    Full Text Available The risk of obesity in adulthood is subject to programming beginning at conception. In animal models, exposure to maternal obesity and high fat diets influences the risk of obesity in the offspring. Among other long-term changes, offspring from obese rats develop hyperinsulinemia, hepatic steatosis, and lipogenic gene expression in the liver at weaning. However, the precise underlying mechanisms leading to metabolic dysregulation in the offspring remains unclear. Using a rat model of overfeeding-induced obesity, we previously demonstrated that exposure to maternal obesity from pre-conception to birth, is sufficient to program increased obesity risk in the offspring. Offspring of obese rat dams gain greater body weight and fat mass when fed high fat diet (HFD as compared to lean dam. Since, disruptions of diurnal circadian rhythm are known to detrimentally impact metabolically active tissues such as liver, we examined the hypothesis that maternal obesity leads to perturbations of core clock components and thus energy metabolism in offspring liver. Offspring from lean and obese dams were examined at post-natal day 35, following a short (2 wk HFD challenge. Hepatic mRNA expression of circadian (CLOCK, BMAL1, REV-ERBα, CRY, PER and metabolic (PPARα, SIRT1 genes were strongly suppressed in offspring exposed to both maternal obesity and HFD. Using a mathematical model, we identified two distinct biological mechanisms that modulate PPARα mRNA expression: i decreased mRNA synthesis rates; and ii increased non-specific mRNA degradation rate. Moreover, our findings demonstrate that changes in PPARα transcription were associated with epigenomic alterations in H3K4me3 and H3K27me3 histone marks near the PPARα transcription start site. Our findings indicated that offspring from obese rat dams have detrimental alternations to circadian machinery that may contribute to impaired liver metabolism in response to HFD, specifically via reduced PPAR

  4. Selenium for preventing cancer

    Science.gov (United States)

    Vinceti, Marco; Dennert, Gabriele; Crespi, Catherine M; Zwahlen, Marcel; Brinkman, Maree; Zeegers, Maurice PA; Horneber, Markus; D'Amico, Roberto; Del Giovane, Cinzia

    2015-01-01

    Background This review is an update of the first Cochrane publication on selenium for preventing cancer (Dennert 2011). Selenium is a metalloid with both nutritional and toxicological properties. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers. Objectives Two research questions were addressed in this review: What is the evidence for: an aetiological relation between selenium exposure and cancer risk in humans? andthe efficacy of selenium supplementation for cancer prevention in humans? Search methods We conducted electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL, 2013, Issue 1), MEDLINE (Ovid, 1966 to February 2013 week 1), EMBASE (1980 to 2013 week 6), CancerLit (February 2004) and CCMed (February 2011). As MEDLINE now includes the journals indexed in CancerLit, no further searches were conducted in this database after 2004. Selection criteria We included prospective observational studies (cohort studies including sub-cohort controlled studies and nested case-control studies) and randomised controlled trials (RCTs) with healthy adult participants (18 years of age and older). Data collection and analysis For observational studies, we conducted random effects meta-analyses when five or more studies were retrieved for a specific outcome. For RCTs, we performed random effects meta-analyses when two or more studies were available. The risk of bias in observational studies was assessed using forms adapted from the Newcastle-Ottawa Quality Assessment Scale for cohort and case-control studies; the criteria specified in the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate the risk of bias in RCTs. Main results We included 55 prospective observational studies (including more than 1,100,000 participants) and eight RCTs (with a total of 44,743 participants). For the observational studies, we found lower cancer incidence (summary odds ratio (OR) 0

  5. Fetal alcohol exposure disrupts metabolic signaling in hypothalamic proopiomelanocortin neurons via a circadian mechanism in male mice.

    Science.gov (United States)

    Agapito, Maria A; Zhang, Changqing; Murugan, Sengottuvelan; Sarkar, Dipak K

    2014-07-01

    Early-life ethanol feeding (ELAF) alters the metabolic function of proopiomelanocortin (POMC)-producing neurons and the circadian expression of clock regulatory genes in the hypothalamus. We investigated whether the circadian mechanisms control the action of ELAF on metabolic signaling genes in POMC neurons. Gene expression measurements of Pomc and a selected group of metabolic signaling genes, Stat3, Sirt1, Pgc1-α, and Asb4 in laser-captured microdissected POMC neurons in the hypothalamus of POMC-enhanced green fluorescent protein mice showed circadian oscillations under light/dark and constant darkness conditions. Ethanol programmed these neurons such that the adult expression of Pomc, Stat3, Sirt, and Asb4 gene transcripts became arrhythmic. In addition, ELAF dampened the circadian peak of gene expression of Bmal1, Per1, and Per2 in POMC neurons. We crossed Per2 mutant mice with transgenic POMC-enhanced green fluorescent protein mice to determine the role of circadian mechanism in ELAF-altered metabolic signaling in POMC neurons. We found that ELAF failed to alter arrhythmic expression of most circadian genes, with the exception of the Bmal1 gene and metabolic signaling regulating genes in Per2 mutant mice. Comparison of the ELAF effects on the circadian blood glucose in wild-type and Per2 mutant mice revealed that ELAF dampened the circadian peak of glucose, whereas the Per2 mutation shifted the circadian cycle and prevented the ELAF dampening of the glucose peak. These data suggest the possibility that the Per2 gene mutation may regulate the ethanol actions on Pomc and the metabolic signaling genes in POMC neurons in the hypothalamus by blocking circadian mechanisms.

  6. Genetic Disruption of Protein Kinase STK25 Ameliorates Metabolic Defects in a Diet-Induced Type 2 Diabetes Model

    DEFF Research Database (Denmark)

    Amrutkar, Manoj; Cansby, Emmelie; Chursa, Urszula

    2015-01-01

    Understanding the molecular networks controlling ectopic lipid deposition, glucose tolerance, and insulin sensitivity is essential to identifying new pharmacological approaches to treat type 2 diabetes. We recently identified serine/threonine protein kinase 25 (STK25) as a negative regulator...... to the metabolic phenotype of Stk25 transgenic mice, reinforcing the validity of the results. The findings suggest that STK25 deficiency protects against the metabolic consequences of chronic exposure to dietary lipids and highlight the potential of STK25 antagonists for the treatment of type 2 diabetes....

  7. JV Task 96 - Phase 2 - Investigating the Importance of the Mercury-Selenium Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas Ralston; Laura Raymond

    2008-03-01

    In order to improve the understanding of the mercury issue, it is vital to study mercury's effects on selenium physiology. While mercury present in the environment or food sources may pose health risks, the protective effects of selenium have not been adequately considered in establishing regulatory policy. Numerous studies report that vulnerability to mercury toxicity is inversely proportional to selenium status or level. However, selenium status has not been considered in the development of the reference dosage levels for mercury exposure. Experimental animals fed low-selenium diets are far more vulnerable to mercury toxicity than animals fed normal selenium, and animals fed selenium-rich diets are even more resistant. Selenium-dependent enzymes in brain and endocrine tissues can be impaired by excessive mercury exposure, apparently because mercury has an extremely high binding affinity for selenium. When selenium becomes bound to mercury, it is unable to participate in the metabolic cycling of selenoprotein synthesis. Because of mercury-dependent impairments of selenoprotein synthesis, various antioxidant and regulatory functions in brain biochemistry are compromised. This report details a 2-year multiclient-funded research program designed to examine the interactions between mercury and selenium in animal models. The studies explored the effects of dietary intakes of toxic amounts of methylmercury and the protective effects of the normal dietary range of selenium in counteracting mercury toxicity. This study finds that the amounts of selenium present in ocean fish are sufficient to protect against far larger quantities of methylmercury than those present in typical seafoods. Toxic effects of methylmercury exposure were not directly proportional to mercury concentrations in blood, brain, or any other tissues. Instead, mercury toxicity was proportional to molar ratios of mercury relative to selenium. In order to accurately assess risk associated with

  8. Shift work or food intake during the rest phase promotes metabolic disruption and desynchrony of liver genes in male rats.

    Science.gov (United States)

    Salgado-Delgado, Roberto C; Saderi, Nadia; Basualdo, María del Carmen; Guerrero-Vargas, Natali N; Escobar, Carolina; Buijs, Ruud M

    2013-01-01

    In the liver, clock genes are proposed to drive metabolic rhythms. These gene rhythms are driven by the suprachiasmatic nucleus (SCN) mainly by food intake and via autonomic and hormonal pathways. Forced activity during the normal rest phase, induces also food intake, thus neglecting the signals of the SCN, leading to conflicting time signals to target tissues of the SCN. The present study explored in a rodent model of night-work the influence of food during the normal sleep period on the synchrony of gene expression between clock genes and metabolic genes in the liver. Male Wistar rats were exposed to forced activity for 8 h either during the rest phase (day) or during the active phase (night) by using a slow rotating wheel. In this shift work model food intake shifts spontaneously to the forced activity period, therefore the influence of food alone without induced activity was tested in other groups of animals that were fed ad libitum, or fed during their rest or active phase. Rats forced to be active and/or eating during their rest phase, inverted their daily peak of Per1, Bmal1 and Clock and lost the rhythm of Per2 in the liver, moreover NAMPT and metabolic genes such as Pparα lost their rhythm and thus their synchrony with clock genes. We conclude that shift work or food intake in the rest phase leads to desynchronization within the liver, characterized by misaligned temporal patterns of clock genes and metabolic genes. This may be the cause of the development of the metabolic syndrome and obesity in individuals engaged in shift work.

  9. Transplacental exposure to inorganic arsenic at a hepatocarcinogenic dose induces fetal gene expression changes in mice indicative of aberrant estrogen signaling and disrupted steroid metabolism

    International Nuclear Information System (INIS)

    Liu Jie; Xie Yaxiong; Cooper, Ryan; Ducharme, Danica M.K.; Tennant, Raymond; Diwan, Bhalchandra A.; Waalkes, Michael P.

    2007-01-01

    Exposure to inorganic arsenic in utero in C3H mice produces hepatocellular carcinoma in male offspring when they reach adulthood. To help define the molecular events associated with the fetal onset of arsenic hepatocarcinogenesis, pregnant C3H mice were given drinking water containing 0 (control) or 85 ppm arsenic from day 8 to 18 of gestation. At the end of the arsenic exposure period, male fetal livers were removed and RNA isolated for microarray analysis using 22K oligo chips. Arsenic exposure in utero produced significant (p < 0.001) alterations in expression of 187 genes, with approximately 25% of aberrantly expressed genes related to either estrogen signaling or steroid metabolism. Real-time RT-PCR on selected genes confirmed these changes. Various genes controlled by estrogen, including X-inactive-specific transcript, anterior gradient-2, trefoil factor-1, CRP-ductin, ghrelin, and small proline-rich protein-2A, were dramatically over-expressed. Estrogen-regulated genes including cytokeratin 1-19 and Cyp2a4 were over-expressed, although Cyp3a25 was suppressed. Several genes involved with steroid metabolism also showed remarkable expression changes, including increased expression of 17β-hydroxysteroid dehydrogenase-7 (HSD17β7; involved in estradiol production) and decreased expression of HSD17β5 (involved in testosterone production). The expression of key genes important in methionine metabolism, such as methionine adenosyltransferase-1a, betaine-homocysteine methyltransferase and thioether S-methyltransferase, were suppressed. Thus, exposure of mouse fetus to inorganic arsenic during a critical period in development significantly alters the expression of various genes encoding estrogen signaling and steroid or methionine metabolism. These alterations could disrupt genetic programming at the very early life stage, which could impact tumor formation much later in adulthood

  10. Proteomic Analysis of Chloroplast-to-Chromoplast Transition in Tomato Reveals Metabolic Shifts Coupled with Disrupted Thylakoid Biogenesis Machinery and Elevated Energy-Production Components1[W

    Science.gov (United States)

    Barsan, Cristina; Zouine, Mohamed; Maza, Elie; Bian, Wanping; Egea, Isabel; Rossignol, Michel; Bouyssie, David; Pichereaux, Carole; Purgatto, Eduardo; Bouzayen, Mondher; Latché, Alain; Pech, Jean-Claude

    2012-01-01

    A comparative proteomic approach was performed to identify differentially expressed proteins in plastids at three stages of tomato (Solanum lycopersicum) fruit ripening (mature-green, breaker, red). Stringent curation and processing of the data from three independent replicates identified 1,932 proteins among which 1,529 were quantified by spectral counting. The quantification procedures have been subsequently validated by immunoblot analysis of six proteins representative of distinct metabolic or regulatory pathways. Among the main features of the chloroplast-to-chromoplast transition revealed by the study, chromoplastogenesis appears to be associated with major metabolic shifts: (1) strong decrease in abundance of proteins of light reactions (photosynthesis, Calvin cycle, photorespiration) and carbohydrate metabolism (starch synthesis/degradation), mostly between breaker and red stages and (2) increase in terpenoid biosynthesis (including carotenoids) and stress-response proteins (ascorbate-glutathione cycle, abiotic stress, redox, heat shock). These metabolic shifts are preceded by the accumulation of plastid-encoded acetyl Coenzyme A carboxylase D proteins accounting for the generation of a storage matrix that will accumulate carotenoids. Of particular note is the high abundance of proteins involved in providing energy and in metabolites import. Structural differentiation of the chromoplast is characterized by a sharp and continuous decrease of thylakoid proteins whereas envelope and stroma proteins remain remarkably stable. This is coincident with the disruption of the machinery for thylakoids and photosystem biogenesis (vesicular trafficking, provision of material for thylakoid biosynthesis, photosystems assembly) and the loss of the plastid division machinery. Altogether, the data provide new insights on the chromoplast differentiation process while enriching our knowledge of the plant plastid proteome. PMID:22908117

  11. Lack of significant metabolic abnormalities in mice with liver-specific disruption of 11β-hydroxysteroid dehydrogenase type 1.

    LENUS (Irish Health Repository)

    Lavery, Gareth G

    2012-07-01

    Glucocorticoids (GC) are implicated in the development of metabolic syndrome, and patients with GC excess share many clinical features, such as central obesity and glucose intolerance. In patients with obesity or type 2 diabetes, systemic GC concentrations seem to be invariably normal. Tissue GC concentrations determined by the hypothalamic-pituitary-adrenal (HPA) axis and local cortisol (corticosterone in mice) regeneration from cortisone (11-dehydrocorticosterone in mice) by the 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzyme, principally expressed in the liver. Transgenic mice have demonstrated the importance of 11β-HSD1 in mediating aspects of the metabolic syndrome, as well as HPA axis control. In order to address the primacy of hepatic 11β-HSD1 in regulating metabolism and the HPA axis, we have generated liver-specific 11β-HSD1 knockout (LKO) mice, assessed biomarkers of GC metabolism, and examined responses to high-fat feeding. LKO mice were able to regenerate cortisol from cortisone to 40% of control and had no discernible difference in a urinary metabolite marker of 11β-HSD1 activity. Although circulating corticosterone was unaltered, adrenal size was increased, indicative of chronic HPA stimulation. There was a mild improvement in glucose tolerance but with insulin sensitivity largely unaffected. Adiposity and body weight were unaffected as were aspects of hepatic lipid homeostasis, triglyceride accumulation, and serum lipids. Additionally, no changes in the expression of genes involved in glucose or lipid homeostasis were observed. Liver-specific deletion of 11β-HSD1 reduces corticosterone regeneration and may be important for setting aspects of HPA axis tone, without impacting upon urinary steroid metabolite profile. These discordant data have significant implications for the use of these biomarkers of 11β-HSD1 activity in clinical studies. The paucity of metabolic abnormalities in LKO points to important compensatory effects by HPA

  12. Biomarkers of selenium status

    Science.gov (United States)

    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...

  13. Selenium Treatment Technologies

    Science.gov (United States)

    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...

  14. Disruption of the Acyl-CoA binding protein gene delays hepatic adaptation to metabolic changes at weaning

    DEFF Research Database (Denmark)

    Neess, Ditte; Marcher, Ann-Britt; Bloksgaard, Maria

    The acyl-CoA binding protein/diazepam binding inhibitor (ACBP/DBI) is an evolutionary conserved intracellular protein that binds C14-C22 acyl-CoA esters with very high affinity. ACBP is thought to act as an acyl-CoA transporter, and in vitro analyses have indicated that ACBP can transport acyl......-CoA esters between different enzymatic systems. However, little is known about the in vivo function in mammalian cells. We have generated mice with targeted disruption of ACBP (ACBP-/-). These mice are viable and fertile and develop normally. However, around weaning the ACBP-/- mice show decreased growth......) family, around the weaning period. As a result, the hepatic de novo cholesterogenesis is significantly decreased at weaning. The delayed induction of SREBP target genes around weaning is caused by a compromised processing and decreased expression of SREBP precursors leading to reduced binding of SREBP...

  15. Hypercholesterolemia and apolipoprotein B expression: Regulation by selenium status

    Directory of Open Access Journals (Sweden)

    Bansal Mohinder P

    2005-11-01

    Full Text Available Abstract Background Apolipoprotein B (apoB contains ligand-binding domain for the binding of LDL to LDL-R site, which enables the removal of LDL from circulation. Our recent data showed that selenium (Se is involved in the lipid metabolism. The present study was aimed to understand the effect of Se deficiency (0.02 ppm and selenium supplementation (1 ppm on apoB expression in liver during hypercholesterolemia in male Sprague Dawley rats. Animals were fed with control and high cholesterol diet (2% for 1 and 2 months. ApoB levels by ELISA and protein expression by western blot was done. Hepatic LDL receptor (LDL-R activity (in vivo and mRNA expression by RT-PCR was monitored. Results In selenium deficiency and on high cholesterol diet (HCD feeding apoB levels increased and LDL-R expression decreased significantly after 2 months. On 1 ppm selenium supplementation apoB expression significantly decreased and LDL-R expression increased after 2 months. But after one month of treatment there was no significant change observed in apoB and LDL-R expression. Conclusion So the present study demonstrates that Se deficiency leads to up regulation of apoB expression during experimental hypercholesterolemia. Selenium supplementation upto 1 ppm leads to downregulation of apoB expression. Further, this study will highlight the nutritional value of Se supplementation in lipid metabolism.

  16. Estrogen-induced disruption of intracellular iron metabolism leads to oxidative stress, membrane damage, and cell cycle arrest in MCF-7 cells.

    Science.gov (United States)

    Bajbouj, Khuloud; Shafarin, Jasmin; Abdalla, Maher Y; Ahmad, Iman M; Hamad, Mawieh

    2017-10-01

    It is well established that several forms of cancer associate with significant iron overload. Recent studies have suggested that estrogen (E2) disrupts intracellular iron homeostasis by reducing hepcidin synthesis and maintaining ferroportin integrity. Here, the ability of E2 to alter intracellular iron status and cell growth potential was investigated in MCF-7 cells treated with increasing concentrations of E2. Treated cells were assessed for intracellular iron status, the expression of key proteins involved in iron metabolism, oxidative stress, cell survival, growth, and apoptosis. E2 treatment resulted in a significant reduction in hepcidin expression and a significant increase in hypoxia-inducible factor 1 alpha, ferroportin, transferrin receptor, and ferritin expression; a transient decrease in labile iron pool; and a significant increase in total intracellular iron content mainly at 20 nM/48 h E2 dose. Treated cells also showed increased total glutathione and oxidized glutathione levels, increased superoxide dismutase activity, and increased hemoxygenase 1 expression. Treatment with E2 at 20 nM for 48 h resulted in a significant reduction in cell growth (0.35/1 migration rate) and decreased cell survival (iron metabolism and precipitates adverse effects concerning cell viability, membrane integrity, and growth potential.

  17. Disruption of the acyl-coa binding protein gene delays hepatic adaptation to metabolic changes at weaning

    DEFF Research Database (Denmark)

    Neess, Ditte; Bloksgaard, Maria; Sørensen, Signe Bek

    2011-01-01

    The acyl-CoA binding protein/diazepam binding inhibitor (ACBP/DBI) is an intracellular protein that binds C14-C22 acyl-CoA esters and is thought to act as an acyl-CoA transporter. In vitro analyses have indicated that ACBP can transport acyl-CoA esters between different enzymatic systems; however....... The delayed induction of SREBP target genes around weaning is caused by a compromised processing and decreased expression of SREBP precursors leading to reduced binding of SREBP to target sites in chromatin. In conclusion, lack of ACBP interferes with the normal metabolic adaptation to weaning and leads...

  18. Acute selenium poisoning in lambs

    Energy Technology Data Exchange (ETDEWEB)

    Gabbedy, B J; Dickson, J

    1969-10-01

    An outbreak of sodium selenite poisoning is reported in which 180 of 190 six-weeks-old lambs died. The estimated dose rate of the selenium was 6.4 mg/kg body weight. Liver concentrations of selenium at the time of poisoning averaged 64 ppM and 15 days later liver and kidney concentrations of selenium averaged 26 ppM and 7.4 ppM respectively.

  19. Selenium in food and health

    National Research Council Canada - National Science Library

    Reilly, Conor

    2006-01-01

    ...) to be a carcinogen and banned as an additive in food. Selenium is considered by some to be a serious hazard to the environment and to animal health. Selenium-contaminated water has brought deformity and death to wildlife in nature reserves in western USA. There is even concern that because of selenium contamination of soil, crops supplied to the great cities of California could become unfit for human consumption. In large areas of China, endemic selenium toxicity is a hazard for locals who depend on cr...

  20. Retention of metabolized antimony, cobalt, iodine, mercury, selenium and zinc in various tissues of the rat following freeze-drying and oven-drying at different temperatures

    International Nuclear Information System (INIS)

    Iyengar, G.V.; Kasperek, K.; Feinendegen, L.E.

    1977-01-01

    Loss of Sb, Co, I, Hg, Se, and Zn during freeze-drying and oven-drying at 80 0 C, 105 0 C, and 120 0 C were studied in rat tissues that contained metabolized radioactive isotopes. No loss was observed for any of the 6 elements on freeze-drying. However, tissue-specific differences were observed in many cases for the elements Hg, Se, I, and Sb on oven-drying. Although the losses were statistically significant, they remained in most cases between 2 and 10%, with the exception of Hg at 120 0 C, where the losses in some of the tissues were unpredictable. With respect to urine, freeze-drying and oven-drying at 80 0 C were found to be relatively safe for the elements Hg and I. At 105 0 C and above, serious loss of Hg was observed. For Se only freeze-drying was found to be safe

  1. Nutrigenetics, Nutrigenomics, and Selenium

    OpenAIRE

    Ferguson, Lynnette R.; Karunasinghe, Nishi

    2011-01-01

    Selenium (Se) is an important micronutrient that, as a component of selenoproteins, influences oxidative and inflammatory processes. Its’ levels vary considerably, with different ethnic and geographic population groups showing varied conditions, ranging from frank Se deficiencies to toxic effects. An optimum Se level is essential for the maintenance of homeostasis, and this optimum may vary according to life stage, general state of health, and genotype. Nutrigenetic studies of different Se le...

  2. Concentrations of boron, molybdenum, and selenium in chinook salmon

    Science.gov (United States)

    Hamilton, Steven J.; Wiedmeyer, Raymond H.

    1990-01-01

    The concentrations of boron, molybdenum, and selenium in young chinook salmon Oncorhynchus tshawytscha were determined in three partial life cycle chronic toxicity studies. In each study, fish were exposed to a mixture of boron, molybdenum, selenate, and selenite in the proportions found in subsurface agricultural drainage water in the basin of the San Joaquin Valley, California. Tests were conducted in well water and in site-specific fresh and brackish waters. No boron or molybdenum was detected in fish exposed to concentrations as high as 6,046 μg boron/L and 193 μg molybdenum/L for 90 d in well water or fresh water; however, whole-body concentrations of selenium increased with increasing exposure concentrations in well water and fresh water, but not in brackish water. Concentrations of selenium in chinook salmon were strongly correlated with reduced survival and growth of fish in well water and with reduced survival in a 15-d seawater challenge test of fish from fresh water. Concentrations of selenium in fish seemed to reach a steady state after 60 d of exposure in well water or fresh water. Fish in brackish water had only background concentrations of selenium after 60 d of exposure, and no effects on survival and growth in brackish water or on survival in a 10-d seawater challenge test were exhibited. This lack of effect in brackish water was attributed to initiation of the study with advanced fry, which were apparently better able to metabolize the trace element mixture than were the younger fish used in studies with well water and fresh water. In all three experimental waters, concentration factors (whole-body concentration/waterborne concentration) for selenium decreased with increasing exposure concentrations, suggesting decreased uptake or increased excretion, or both, of selenium at the higher concentrations.

  3. Microbial selenium sulfide reduction for selenium recovery from wastewater

    NARCIS (Netherlands)

    Hageman, S.P.W.; Weijden, van der R.D.; Stams, A.J.M.; Cappellen, van P.; Buisman, C.J.N.

    2017-01-01

    Microbial reduction of selenium sulfide (SeS2) is a key step in a new treatment process to recover selenium from selenate and selenite streams. In this process, selenate is first reduced to selenite, and subsequently selenite is reduced by sulfide and precipitates from the solution as SeS2. The

  4. Metabolism

    Science.gov (United States)

    ... Are More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood Test: Basic Metabolic Panel (BMP) Activity: Endocrine System Growth Disorders Diabetes Center Thyroid Disorders Your Endocrine System Movie: Endocrine ...

  5. Selenium accumulation in lettuce germplasm

    Science.gov (United States)

    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...

  6. SELENIUM SUBSTITUTION – EFFECT ON THYROID FUNCTION

    Directory of Open Access Journals (Sweden)

    Milica Pešić

    2015-03-01

    Full Text Available The understanding of the essential role of selenium (Se in thyroid hormone synthesis, metabolism and action, as well as normal thyroid function, increased during the past decades. The thyroid gland is among the human tissues with the highest Se content per mas unit, similar to other endocrine organs and brain. Biological actions of Se are mediated, in most cases, through the expression of at least 30 selenoproteins coded by 25 selenoprotein genes in the human. Via the selenoproteins, selenium can influence the cell function through antioxidant activites, modifying redox status and thyroid hormone synthesis and metabolism. Selenoproteins iodothyronine deiodinases are present in most tissues and have a role to increase the production of bioactive tri-iodothyronine. Futhermore, Se has been shown to be important in the regulation of immune function. Se deficiency is accompained by the loss of immune competence. The links between Se deficiency, altered immune function and inflamation have prompted studies in humans to examine if Se suplementation can modify auto-antibodies production in patients with chronic autoimmune thyroiditis. Until now, several randomised prospective clinical trials have been performed in patients with established chronic autoimmune thyrioditis. The clinical endpoint of each study was the decrease in TPO antibodies concentration after 3-12 months of treatment. Ussualy, the dosage of daily Se supplementation was 200µg. Selenium suplemetation had no significant effect on the concentration of TSH or thyroid hormone concentrations. These studies indicate that Se treatment result in reduced inflammatory activity, but it does not cure chronc autoimmune process.

  7. Addition of selenium nanoparticles to electrospun silk scaffolds improves mammalian cell activity while reducing bacterial growth

    Directory of Open Access Journals (Sweden)

    Stanley Chung

    2016-07-01

    Full Text Available Silk possesses many beneficial wound healing properties, and electrospun scaffolds are especially applicable for skin applications, due to their smaller interstices and higher surface areas compared to non-electrospun equivalents. However, purified silk promotes microbial growth. In contrast, selenium nanoparticles have excellent antibacterial properties and are a novel antimicrobial chemistry. Here, electrospun silk scaffolds were doped with selenium nanoparticles to impart antibacterial properties to the silk scaffolds. Results showed significantly improved bacterial inhibition and improvement in human dermal fibroblast metabolic activity. These results suggest that the addition of selenium nanoparticles to electrospun silk is a promising approach to improve wound healing with reduced infection, without relying on antibiotics.

  8. Metabolism of UV-filter benzophenone-3 by rat and human liver microsomes and its effect on endocrine-disrupting activity

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoko, E-mail: y-watanabe@nichiyaku.ac.jp [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Kojima, Hiroyuki; Takeuchi, Shinji [Hokkaido Institute of Public Health, Kita-19, Nishi-12, Kita-ku, Sapporo 060-0819 (Japan); Uramaru, Naoto [Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Sanoh, Seigo [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Sugihara, Kazumi [Faculty of Pharmaceutical Science, Hiroshima International University, Koshingai 5-1-1, Kure, Hiroshima 737-0112 (Japan); Kitamura, Shigeyuki [Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Ohta, Shigeru [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan)

    2015-01-15

    Benzophenone-3 (2-hydroxy-4-methoxybenzophenone; BP-3) is widely used as sunscreen for protection of human skin and hair from damage by ultraviolet (UV) radiation. In this study, we examined the metabolism of BP-3 by rat and human liver microsomes, and the estrogenic and anti-androgenic activities of the metabolites. When BP-3 was incubated with rat liver microsomes in the presence of NADPH, 2,4,5-trihydroxybenzophenone (2,4,5-triOH BP) and 3-hydroxylated BP-3 (3-OH BP-3) were newly identified as metabolites, together with previously detected metabolites 5-hydroxylated BP-3 (5-OH BP-3), a 4-desmethylated metabolite (2,4-diOH BP) and 2,3,4-trihydroxybenzophenone (2,3,4-triOH BP). In studies with recombinant rat cytochrome P450, 3-OH BP-3 and 2,4,5-triOH BP were mainly formed by CYP1A1. BP-3 was also metabolized by human liver microsomes and CYP isoforms. In estrogen reporter (ER) assays using estrogen-responsive CHO cells, 2,4-diOH BP exhibited stronger estrogenic activity, 2,3,4-triOH BP exhibited similar activity, and 5-OH BP-3, 2,4,5-triOH BP and 3-OH BP-3 showed lower activity as compared to BP-3. Structural requirements for activity were investigated in a series of 14 BP-3 derivatives. When BP-3 was incubated with liver microsomes from untreated rats or phenobarbital-, 3-methylcholanthrene-, or acetone-treated rats in the presence of NADPH, estrogenic activity was increased. However, liver microsomes from dexamethasone-treated rats showed decreased estrogenic activity due to formation of inactive 5-OH BP-3 and reduced formation of active 2,4-diOH BP. Anti-androgenic activity of BP-3 was decreased after incubation with liver microsomes. - Highlights: • Metabolic modification of the endocrine-disrupting activity of BP-3 was examined. • 2,4,5-TriOH BP and 3-OH BP-3 were identified as new BP-3 metabolites. • 2,4-DiOH BP and 2,3,4-triOH BP exhibited high or similar estrogenic activities. • Estrogenic activity of BP-3 was enhanced by incubation with rat liver

  9. Targeted sulphur and selenium speciation in yeast by parallel elemental and molecular mass spectrometry

    DEFF Research Database (Denmark)

    Hillestrøm, Peter René; Mapelli, Valeria; Olsson, Lisbeth

    Selenium supplement, often selenized yeast, are currently the subject of intense study owing to their potential preventive effects against cancer. However, fundamental knowledge of the yeast’s metabolism is required for metabolic engineering biosynthetic production of potent Se-species. A method ...... determination of metabolites present. Selenium metabolites were detected by simultaneous ICP-MS and ESI-MS/MS while targeted sulphur species were determined by ESI-MS/MS.......Selenium supplement, often selenized yeast, are currently the subject of intense study owing to their potential preventive effects against cancer. However, fundamental knowledge of the yeast’s metabolism is required for metabolic engineering biosynthetic production of potent Se-species. A method...

  10. Metabolism

    Science.gov (United States)

    ... lin), which signals cells to increase their anabolic activities. Metabolism is a complicated chemical process, so it's not ... how those enzymes or hormones work. When the metabolism of body chemicals is ... Hyperthyroidism (pronounced: hi-per-THIGH-roy-dih-zum). Hyperthyroidism ...

  11. Investigating Disruption

    DEFF Research Database (Denmark)

    Lundgaard, Stine Schmieg; Rosenstand, Claus Andreas Foss

    This book shares knowledge collected from 2015 and onward within the Consortium for Digital Disruption anchored at Aalborg University (www.dd.aau.dk). Evidenced by this publication, the field of disruptive innovation research has gone through several stages of operationalizing the theory. In recent...... years, researchers are increasingly looking back towards the origins of the theory in attempts to cure it from its most obvious flaws. This is especially true for the use of the theory in making predictions about future disruptions. In order to continue to develop a valuable theory of disruption, we...... find it useful to first review what the theory of disruptive innovation initially was, how it has developed, and where we are now. A cross section of disruptive innovation literature has been reviewed in order to form a general foundation from which we might better understand the changing world...

  12. Epigenetic Regulation of Inflammatory Gene Expression in Macrophages by Selenium

    Science.gov (United States)

    Narayan, Vivek; Ravindra, Kodihalli C.; Liao, Chang; Kaushal, Naveen; Carlson, Bradley A.; Prabhu, K. Sandeep

    2014-01-01

    Acetylation of histone and non-histone proteins by histone acetyltransferases plays a pivotal role in the expression of pro-inflammatory genes. Given the importance of dietary selenium in mitigating inflammation, we hypothesized that selenium supplementation may regulate inflammatory gene expression at the epigenetic level. The effect of selenium towards histone acetylation was examined in both in vitro and in vivo models of inflammation by chromatin immunoprecipitation (ChIP) assays and immunoblotting. Our results indicated that selenium supplementation, as selenite, decreased acetylation of histone H4 at K12 and K16 in COX-2 and TNF promoters, and of the p65 subunit of the redox sensitive transcription factor NFκB in primary and immortalized macrophages. On the other hand, selenomethionine had a much weaker effect. Selenite treatment of HIV-1 infected human monocytes also significantly decreased the acetylation of H4 at K12 and K16 on the HIV-1 promoter, supporting the downregulation of proviral expression by selenium. A similar decrease in histone acetylation was also seen in the colonic extracts of mice treated with dextran sodium sulfate that correlated well with the levels of selenium in the diet. Bone marrow-derived macrophages from Trspfl/flCreLysM mice that lack expression of selenoproteins in macrophages confirmed the important role of selenoproteins in the inhibition of histone H4 acetylation. Our studies suggest that the ability of selenoproteins to skew the metabolism of arachidonic acid to contribute, in part, to their ability to inhibit histone acetylation. In summary, our studies suggest a new role for selenoproteins in the epigenetic modulation of pro-inflammatory genes. PMID:25458528

  13. Mechanism of Selenium Loss in Copper Slag

    Science.gov (United States)

    Desai, Bhavin; Tathavadkar, Vilas; Basu, Somnath

    2018-06-01

    During smelting of copper sulfide concentrate, selenium is distributed between silica-saturated iron-silicate slag and copper-iron sulfide matte. The recovery coefficients of selenium between slag and matte were determined as a function of the initial concentration of selenium at 1523 K (1250 °C) under an inert atmosphere in a vertical tubular furnace. The initial concentration of selenium was varied by the addition of metallic selenium as well as selenium dioxide to the mixture of slag and matte. Analysis of the results indicated high affinity of selenium for matte. The apparent loss of selenium with the slag was attributed to the presence of selenium-enriched matte particles entrapped in the slag, rather than dissolved SeO2. The mechanisms proposed by previous investigators were discussed and also compared with the results of the present investigation.

  14. Mechanism of Selenium Loss in Copper Slag

    Science.gov (United States)

    Desai, Bhavin; Tathavadkar, Vilas; Basu, Somnath

    2018-03-01

    During smelting of copper sulfide concentrate, selenium is distributed between silica-saturated iron-silicate slag and copper-iron sulfide matte. The recovery coefficients of selenium between slag and matte were determined as a function of the initial concentration of selenium at 1523 K (1250 °C) under an inert atmosphere in a vertical tubular furnace. The initial concentration of selenium was varied by the addition of metallic selenium as well as selenium dioxide to the mixture of slag and matte. Analysis of the results indicated high affinity of selenium for matte. The apparent loss of selenium with the slag was attributed to the presence of selenium-enriched matte particles entrapped in the slag, rather than dissolved SeO2. The mechanisms proposed by previous investigators were discussed and also compared with the results of the present investigation.

  15. Nanosecond pulsed electric field (nsPEF) disrupts the structure and metabolism of human Echinococcus granulosus protoscolex in vitro with a dose effect.

    Science.gov (United States)

    Zhang, Ruiqing; Aji, Tuerganaili; Shao, Yingmei; Jiang, Tiemin; Yang, Lei; Lv, Weimin; Chen, Yonggang; Chen, Xinhua; Wen, Hao

    2017-04-01

    The number of interventional treatments for hepatic cystic echinococcosis is increasing, but the chemicals or high temperatures used in these methodologies cause biliary complications, thus limiting their clinical applications. This experimental study aimed to apply a novel, non-thermal, non-chemical ablation method termed nanosecond pulsed electric field (nsPEF) for the treatment of human hepatic cystic echinococcosis. The nsPEF treatment parameters against protoscolices from human hepatic cystic echinococcosis were optimized in vitro. The efficacy and mechanism of nsPEF treatment were also investigated. Fresh protoscolices were isolated from human hepatic cystic echinococcosis and were exposed to 300 ns of nsPEF with different field strengths (0, 7, 14, 21, and 29 kV/cm) and pulse numbers (50 and 100 pulses). Then, the viability of the nsPEF-treated protoscolices was evaluated in vitro. Morphological and ultra-structural changes were visualized with H&E staining and scanning electron microscopy. The membrane enzyme activity of alkaline phosphatase (AP) and gamma-glutamyl-transpeptidase (GGT) was measured. nsPEF caused dose-dependent protoscolex death. One-hundred pulses of nsPEF at 21 kV/cm or higher caused a significant increase in the death rate of protoscolices. nsPEF induced significant lethal damage with 50 pulses at 21 or 29 kV/cm and with 100 pulses at 14, 21, or 29 kV/cm, accompanied by morphological destruction and increased levels of AP and GGT membrane enzymes. Thus, nsPEF induced dose-dependent protoscolex mortality and caused destruction of protoscolices and increased membrane enzymes. The mechanism may involve direct damage to the membrane structures of the protoscolices, promoting enzyme exhaustion and disruption of metabolism.

  16. Enrichment of meat products with selenium by its introduction to mixed feed compounds for birds

    Directory of Open Access Journals (Sweden)

    А. Sobolev

    2017-07-01

    Full Text Available Selenium is a biologically active microelement, contained in a number of hormones and enzymes. In a bird or animal organism selenium performs the following functions: strengthens the immune system, stimulates formation of antibodies, macrophages and interferons. Also, it is a powerful antioxidant agent. It stimulates processes of metabolism in the organism, protects the organism against toxic manifestations of cadmium, lead, thalium and silver; stimulates reproductive function, decreases acute development of inflammatory processes; stabilizes functioning of the nervous system; normalizes functioning of the endocrine system. Furthermore, it stimulates synthesis of hemoglobin, takes part in secretion of erythrocutes, neutralizes toxins, prevents and stops development of malignant tumors. It also has a positive effect on the cardiovascular system of an animal organism: prevents myocardosis and decreases the risk of development of cardiovascular diseases. Deficiency of selenium in the organism causes (depending upon the extent of deficiency either physiological changes within the regulatory norm, significant disorders of the metabolism, or specific diseases. Around 75 different diseases and symptoms of pain are related to selenium deficiency. In most countries, the level of selenium consumption remains low (20–40 µg/day. There are several ways of improving of the selenium consumption of a population: consumption of selenium as a medication or dietary supplement, producing selenium-enriched bread, growing greens and vegetables rich in selenium, producing selenium-enriched beverages, products of animal origin, which would be rich in selenium. In the scientific-agricultural sphere studies have been made on the influence of adding different doses (0.2–0.6 mg/kg of selenium in mixed feeds and peculiarities of its depositing and distribution in the muscle tissues of young growth of different species of poultry. It has been found that feeding broiler

  17. Acute selenium poisoning in cattle

    Energy Technology Data Exchange (ETDEWEB)

    Shortridge, E H; O' Hara, P J; Marshall, P M

    1971-01-01

    Three hundred and seventy-six (67%) of 557 calves of approximately 150-200 kg live-weight died following subcutaneous injection of a solution containing 100 mg selenium as sodium selenite. Eight per cent of the 254 heifer calves and 56% of the 303 steers died. The calves had endured the stress of being weaned twice and held in stockyards twice as well as encountering wet weather during the 4 days before receiving the selenium. The heifer calves were also vaccinated with Br. abortus strain 19 vaccine at the same time as receiving the selenium. The clinical signs and pathological findings of circulatory failure and myocardial damage were similar to those previously reported in acute selenium poisoning.

  18. Effects of selenium biofortification on crop nutritional quality

    Directory of Open Access Journals (Sweden)

    Mario eMalagoli

    2015-04-01

    Full Text Available 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 sulphur (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.

  19. Disruption model

    International Nuclear Information System (INIS)

    Murray, J.G.; Bronner, G.

    1982-07-01

    Calculations of disruption time and energy dissipation have been obtained by simulating the plasma as an electrical conducting loop that varies in resistivity, current density, major radius. The calculations provide results which are in good agreement with experimental observations. It is believed that this approach allows engineering designs for disruptions to be completed in large tokamaks such as INTOR or FED

  20. Sulfur, selenium, tellurium and polonium

    International Nuclear Information System (INIS)

    Berry, F.J.

    1987-01-01

    This chapter on the coordination compounds of sulfur, selenium, tellurium and polonium starts with an introduction to the bonding, valence and geometry of the elements. Complexes of the group VIB elements are discussed with particular reference to the halo and pseudohalide complexes, oxo acid complexes, oxygen and nitrogen donor complexes and sulfur and selenium donor complexes. There is a section on the biological properties of the complexes discussed. (UK)

  1. Trace Element Analysis of Selenium

    International Nuclear Information System (INIS)

    Soliman, M.S.A.

    2010-01-01

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

  2. Histopathological changes due to the effect of selenium in experimental cockerels

    Directory of Open Access Journals (Sweden)

    S.A.A Latheef

    2014-01-01

    Full Text Available Background & objectives: Selenium usually acts as an antioxidant at optimal levels in the body and increased levels are toxic. In this study an attempt was made to evaluate the effect of an optimum dose (0.14 mg of selenium on histopathological changes in experimental hypercholesterolemia in cockerels. Methods: The effect of selenium (0.14 mg was investigated on histopathological changes in four tissues namely liver, kidney, heart, and descending aorta in cockerel animal model. Animals were either fed with stock diet (group C, stock diet with cholesterol (group CH, stock diet with selenium (group Se, stock diet, selenium and cholesterol (group CH+Se for six months. Animals were sacrified and the tissues were isolated and subjected to histopathological study. Results: Xanthochromatic collections in liver were observed in group CH; hydropic degeneration in group Se and lobular disarray, hydropic degeneration and kuppfer cell hyperplasia in group CH+Se were observed. In kidney, mild mononuclear infiltration was observed in interstitium in groups CH, Se and CH+Se. myocyte disruption, and mononuclear infiltration in group CH and c0 H+Se, and disruption of muscle bundles with vascular congestion in group Se were observed. Smooth muscle proliferation in the media of blood vessel was observed in groups CH, Se and CH+Se. Interpretation & conclusions: The results of the present study suggested that the optimum dose of (140 ΅g/day feeding induced atherogenesis by inflammation and smooth muscle proliferation in cockerels with experimentally induced hypercholesterolaemia.

  3. Effect of nano-sized, elemental selenium supplement on the proteome of chicken liver.

    Science.gov (United States)

    Gulyas, G; Csosz, E; Prokisch, J; Javor, A; Mezes, M; Erdelyi, M; Balogh, K; Janaky, T; Szabo, Z; Simon, A; Czegledi, L

    2017-06-01

    The nano-sized (100-500 nm) selenium has higher bioavailability and relatively lower toxicity compared to other selenium forms. The objective of the present study was to compare liver proteome profiles of broiler chicken fed with control diet without Se supplementation and diet supplemented with nano-Se with 4.25 mg/kg DM. Differential proteome analyses were performed by two-dimensional gel electrophoresis (2D-PAGE) followed by tryptic digestion and protein identification by liquid chromatography-mass spectrometry (LC-MS). Seven hundred and eight spots were detected, and 18 protein spots showed significant difference in their intensity (p selenium supplementation induced a dietary stress. Selenium supplementation may influence the metabolism of fatty acids and carbohydrates and antioxidant system, and increase the quantity of cytoskeletal actin and the expression of actin regulatory protein as well. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

  4. Selenium Content, Influential Factors Within the Plant and the Transformation of Different Selenium Specification

    Directory of Open Access Journals (Sweden)

    LIU Yuan-yuan

    2014-12-01

    Full Text Available The paper collected relevant literatures on selenium and explored the function to plant, selenium content, influential factors and selenium specification and transformation. We believed that there should be more deep researches on function of selenium to plant. Approaches of molecular, genetic engineering and isotope could be employed to breed selenium rich crops and possibilities in practice. More efforts should be spent on the technologies research for improving selenium level in crops under natural soil conditions to sustainably utilize the selenium resources.

  5. Biomarkers of Selenium Chemoprevention of Prostate Cancer

    National Research Council Canada - National Science Library

    Dong, Yan

    2003-01-01

    The purpose of the present study was to examine the mechanism of selenium growth inhibition in PC-3 human prostate cancer cells Selenium retarded cell cycle progression at multiple transition points...

  6. A Study of Selenium in Leprosy

    Directory of Open Access Journals (Sweden)

    Donna Partogi

    2018-03-01

    CONCLUSIONS: Selenium serum levels of patients with PB leprosy are higher than patients with MB leprosy, and high bacteriological index in patients with leprosy were correlated with low selenium serum levels.

  7. Disrupted Disclosure

    DEFF Research Database (Denmark)

    Krause Hansen, Hans; Uldam, Julie

    appearances become challenged through disruptive disclosures in mediaenvironments characterized by multiple levels of visibility, with companies both observing andbeing observed by civil society groups that criticize them; (c) why and how the mobilization aroundtransparency and ensuing practices...

  8. Family Disruptions

    Science.gov (United States)

    ... Spread the Word Shop AAP Find a Pediatrician Family Life Medical Home Family Dynamics Adoption & Foster Care ... Life Listen Español Text Size Email Print Share Family Disruptions Page Content Article Body No matter how ...

  9. Selenium plating of aluminium and nickel surfaces

    International Nuclear Information System (INIS)

    Qureshi, N.; Shams, N.; Kamal, A.; Ashraf, A.

    1993-01-01

    Selenium exhibits photovoltaic and photoconductive properties. This makes selenium useful in the production of photocells, exposure meters for photographic use, in solar cells, etc. In commerce, selenium coated surfaces are extensively used as photo receptive drums in the xerography machines for reproducing documents. Laboratory experiments were designed to obtain selenium plating on different materials. Of the various electrodes tested for cathodic deposition, anodized aluminum and nickel plated copper were found to give good results. (author)

  10. A gene-environment interaction analysis of plasma selenium with prevalent and incident diabetes: The Hortega study.

    Science.gov (United States)

    Galan-Chilet, Inmaculada; Grau-Perez, Maria; De Marco, Griselda; Guallar, Eliseo; Martin-Escudero, Juan Carlos; Dominguez-Lucas, Alejandro; Gonzalez-Manzano, Isabel; Lopez-Izquierdo, Raul; Briongos-Figuero, Laisa Socorro; Redon, Josep; Chaves, Felipe Javier; Tellez-Plaza, Maria

    2017-08-01

    Selenium and single-nucleotide-polymorphisms in selenoprotein genes have been associated to diabetes. However, the interaction of selenium with genetic variation in diabetes and oxidative stress-related genes has not been evaluated as a potential determinant of diabetes risk. We evaluated the cross-sectional and prospective associations of plasma selenium concentrations with type 2 diabetes, and the interaction of selenium concentrations with genetic variation in candidate polymorphisms, in a representative sample of 1452 men and women aged 18-85 years from Spain. The geometric mean of plasma selenium levels in the study sample was 84.2µg/L. 120 participants had diabetes at baseline. Among diabetes-free participants who were not lost during the follow-up (N=1234), 75 developed diabetes over time. The multivariable adjusted odds ratios (95% confidence interval) for diabetes prevalence comparing the second and third to the first tertiles of plasma selenium levels were 1.80 (1.03, 3.14) and 1.97 (1.14, 3.41), respectively. The corresponding hazard ratios (95% CI) for diabetes incidence were 1.76 (0.96, 3.22) and 1.80 (0.98, 3.31), respectively. In addition, we observed significant interactions between selenium and polymorphisms in PPARGC1A, and in genes encoding mitochondrial proteins, such as BCS1L and SDHA, and suggestive interactions of selenium with other genes related to selenoproteins and redox metabolism. Plasma selenium was positively associated with prevalent and incident diabetes. While the statistical interactions of selenium with polymorphisms involved in regulation of redox and insulin signaling pathways provide biological plausibility to the positive associations of selenium with diabetes, further research is needed to elucidate the causal pathways underlying these associations. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Digital Disruption

    DEFF Research Database (Denmark)

    Rosenstand, Claus Andreas Foss

    det digitale domæne ud over det niveau, der kendetegner den nuværende debat, så præsenteres der ny viden om digital disruption. Som noget nyt udlægges Clayton Christens teori om disruptiv innovation med et særligt fokus på små organisationers mulighed for eksponentiel vækst. Specielt udfoldes...... forholdet mellem disruption og den stadig accelererende digitale udvikling i konturerne til ny teoridannelse om digital disruption. Bogens undertitel ”faretruende og fascinerende forandringer” peger på, at der er behov for en nuanceret debat om digital disruption i modsætning til den tone, der er slået an i...... videre kalder et ”disruption-råd”. Faktisk er rådet skrevet ind i 2016 regeringsgrundlaget for VLK-regeringen. Disruption af organisationer er ikke et nyt fænomen; men hastigheden, hvormed det sker, er stadig accelererende. Årsagen er den globale mega-trend: Digitalisering. Og derfor er specielt digital...

  12. 21 CFR 573.920 - Selenium.

    Science.gov (United States)

    2010-04-01

    ... section, or as selenium yeast, as provided in paragraph (h) of this section. (c) It is added to feed as... months.” (h) Selenium yeast is a dried, non-viable yeast (Saccharomyces cerevisiae) cultivated in a fed-batch fermentation which provides incremental amounts of cane molasses and selenium salts in a manner...

  13. Joint refinery selenium treatability study

    International Nuclear Information System (INIS)

    Meyer, C.L.; Folwarkow, S.

    1993-01-01

    The San Francisco Regional Water Quality Control Board recently established mass limits on discharges of selenium to the San Francisco Bay from several petroleum refineries. The refineries had been working independently to develop control strategies, including both source control and treatment options, for removal of selenium from their discharges. By January 1992, over fifty different combinations of treatment technologies, wastewater streams, and pretreatment steps had been investigated to determine their effectiveness and feasibility as selenium removal processes. No treatment process studied could achieve the required mass limits without serious negative environmental consequences, such as generation of large amounts of hazardous sludge. To better facilitate the development of a feasible selenium treatment process, the six Bay Area refineries shared results of their studies and identified several technologies that, with further work, could be developed further. This additional work is currently being carried out as part of a joint selenium treatability study sponsored by the Western States Petroleum Association. A review of the previous source control and treatment studies, along with a description of the current treatability studies will be discussed

  14. Determinants of selenium status in healthy adults

    Directory of Open Access Journals (Sweden)

    Hoeg Antonia

    2011-07-01

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

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

    Science.gov (United States)

    Umysová, Dáša; Vítová, Milada; Doušková, Irena; Bišová, Kateřina; Hlavová, Monika; Čížková, Mária; Machát, Jiří; Doucha, Jiří; Zachleder, Vilém

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Doucha Jiří

    2009-05-01

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

  17. Selenium and tellurium nanomaterials

    Science.gov (United States)

    Piacenza, Elena; Presentato, Alessandro; Zonaro, Emanuele; Lampis, Silvia; Vallini, Giovanni; Turner, Raymond J.

    2018-04-01

    Over the last 40 years, the rapid and exponential growth of nanotechnology led to the development of various synthesis methodologies to generate nanomaterials different in size, shape and composition to be applied in various fields. In particular, nanostructures composed of Selenium (Se) or Tellurium (Te) have attracted increasing interest, due to their intermediate nature between metallic and non-metallic elements, being defined as metalloids. Indeed, this key shared feature of Se and Te allows us the use of their compounds in a variety of applications fields, such as for manufacturing photocells, photographic exposure meters, piezoelectric devices, and thermoelectric materials, to name a few. Considering also that the chemical-physical properties of elements result to be much more emphasized when they are assembled at the nanoscale range, huge efforts have been made to develop highly effective synthesis methods to generate Se- or Te-nanomaterials. In this context, the present book chapter will explore the most used chemical and/or physical methods exploited to generate different morphologies of metalloid-nanostructures, focusing also the attention on the major advantages, drawbacks as well as the safety related to these synthetic procedures.

  18. The relationship between selenium and gastric cancer

    International Nuclear Information System (INIS)

    Shi Kuixiong; Ma Guansheng; Zhang Tingyu; Cheng Wufeng; Mao Dajuan; Pan Bixia; Xu Xiuxian

    1993-01-01

    Both sodium selenite and selenium yeast were chosen to block the MNNG mutagenesis. The inhibition rates were 66.5% and 37.9% respectively. The selenium levels in hair, serum and gastric juice, and the contents of nitrosamine in gastric juice were also determined. The results showed that the selenium levels were SG > CAG and Dys > GC (p CAG, Dyas and GC (p < 0.05). 19 cases of CAG patients treated with selenium yeast and 16 cases of the control were observed. After 10 weeks, the selenium levels in serum for the treated group were significantly increased. The symptoms of CAG patients seemed to be alleviated

  19. Selenium-containing indolyl compounds

    DEFF Research Database (Denmark)

    Casaril, Angela M; Ignasiak, Marta T; Chuang, Christine Y

    2017-01-01

    materials, including extracellular matrix (ECM) proteins, within the artery wall. Here we investigated the potential of selenium-containing indoles to afford protection against these oxidants, by determining rate constants (k) for their reaction, and quantifying the extent of damage on isolated ECM proteins......Tyr on HCAEC-ECM were also reduced. These data demonstrate that the novel selenium-containing compounds show high reactivity with oxidants and may modulate oxidative and nitrosative damage at sites of inflammation, contributing to a reduction in tissue dysfunction and atherogenesis....

  20. Long-term selenium status in humans

    International Nuclear Information System (INIS)

    Baskett, C.K.; Spate, V.L.; Mason, M.M.; Nichols, T.A.; Williams, A.; Dubman, I.M.; Gudino, A.; Denison, J.; Morris, J.S.

    2001-01-01

    The association of sub-optimal selenium status with increased risk factors for some cancers has been reported in two recent epidemiological studies. In both studies the same threshold in selenium status was observed, below which, cancer incidence increased. To assess the use of nails as a biologic monitor to measure the long-term selenium status, an eight-year longitudinal study was undertaken with a group of 11 adult subjects, 5 women and 6 men. Selenium has been measured by instrumental neutron activation analysis. Differences between fingernails and toenails with be discussed. In addition, the results will be discussed in the context of the long-term stability of the nail monitor to measure selenium status during those periods when selenium determinants are static; and the changes that occur as a result of selenium supplementation. (author)

  1. Politisk disruption

    DEFF Research Database (Denmark)

    Tække, Jesper

    2018-01-01

    Dette blogindlæg giver en kort analyse af hvordan de sociale medier ved at give en ny tid har åbnet for den disruption af de politiske processer som især Trump stå som et eksempel på.......Dette blogindlæg giver en kort analyse af hvordan de sociale medier ved at give en ny tid har åbnet for den disruption af de politiske processer som især Trump stå som et eksempel på....

  2. Disrupting Business

    DEFF Research Database (Denmark)

    Cox, Geoff; Bazzichelli, Tatiana

    Disruptive Business explores some of the interconnections between art, activism and the business concept of disruptive innovation. With a backdrop of the crisis of financial capitalism, austerity cuts in the cultural sphere, the idea is to focus on potential art strategies in relation to a broken...... economy. In a perverse way, we ask whether this presents new opportunities for cultural producers to achieve more autonomy over their production process. If it is indeed possible, or desirable, what alternative business models emerge? The book is concerned broadly with business as material for reinvention...

  3. Transcriptome profiling reveals the immune response of goose T cells under selenium stimuli.

    Science.gov (United States)

    Cao, Nan; Li, Wanyan; Li, Bingxin; Tian, Yunbo; Xu, Danning

    2017-12-01

    The goose is an economically important poultry species and a principal natural host of avian viruses. This study aimed to determine the effects of selenium on the immune response of geese. Under selenium stimulation, gene expression profiling was investigated using transcriptome sequencing. The selenoproteins were promoted by selenium stimulation, while the heat shock proteins, interleukin and interferons were mainly down-regulated. After comparison, 2228 differentially expressed genes were primarily involved in immune and environmental response, and infectious disease and genetic information processing related pathways were identified. Specifically, the enzymes of the lysosomes which acted as a safeguard in preventing pathogens were mostly up-regulated and six randomly selected differentially expressed genes were validated by quantitative polymerase chain reaction. In addition, the most proportional increased transcription factor family basic helix-loop-helix (bHLH) located in the 5' flank of selenoprotein P-like protein for selenium metabolism was identified by response to the selenium stimulation in this study. These analyses show that selenium can promote immune function by activating selenoproteins, transcript factors and lysosome pathway related genes, while weakening cytokine content genes in geese. © 2017 Japanese Society of Animal Science.

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

    Science.gov (United States)

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

    2011-03-01

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

  5. Nutrigenetics, nutrigenomics, and selenium.

    Science.gov (United States)

    Ferguson, Lynnette R; Karunasinghe, Nishi

    2011-01-01

    Selenium (Se) is an important micronutrient that, as a component of selenoproteins, influences oxidative and inflammatory processes. Its' levels vary considerably, with different ethnic and geographic population groups showing varied conditions, ranging from frank Se deficiencies to toxic effects. An optimum Se level is essential for the maintenance of homeostasis, and this optimum may vary according to life stage, general state of health, and genotype. Nutrigenetic studies of different Se levels, in the presence of genetic variants in selenoproteins, suggest that an effective dietary Se intake for one individual may be very different from that for others. However, we are just starting to learn the significance of various genes in selenoprotein pathways, functional variants in these, and how to combine such data from genes into pathways, alongside dietary intake or serum levels of Se. Advances in systems biology, genetics, and genomics technologies, including genetic/genomic, epigenetic/epigenomic, transcriptomic, proteomic, and metabolomic information, start to make it feasible to assess a comprehensive spectrum of the biological activity of Se. Such nutrigenomic approaches may prove very sensitive biomarkers of optimal Se status at the individual or population level. The premature cessation of a major human Se intervention trial has led to considerable controversy as to the value of Se supplementation at the population level. New websites provide convenient links to current information on methodologies available for nutrigenetics and nutrigenomics. These new technologies will increasingly become an essential tool in optimizing the level of Se and other micronutrients for optimal health, in individuals and in population groups. However, definitive proof of such effects will require very large collaborative studies, international agreement on study design, and innovative approaches to data analysis.

  6. Nutrigenetics, nutrigenomics and selenium

    Directory of Open Access Journals (Sweden)

    Lynnette Robiin Ferguson

    2011-04-01

    Full Text Available Selenium (Se is an important micronutrient that, as a component of selenoproteins, influences oxidative and inflammatory processes. Its’ levels vary considerably, with different ethnic and geographic population groups showing varied conditions, ranging from frank Se deficiencies to toxic effects. An optimum Se level is essential for the maintenance of homeostasis, and this optimum may vary according to life stage, general state of health and genotype. Nutrigenetic studies of different Se levels, in the presence of genetic variants in selenoproteins, suggest that an effective dietary Se intake for one individual may be very different from that for others. However, we are just starting to learn the significance of various genes in selenoprotein pathways, functional variants in these, and how to combine such data from genes into pathways, alongside dietary intake or serum levels of Se. Advances in systems biology, genetics and genomics technologies, including genetic/genomic, epigenetic/epigenomic, transcriptomic, proteomic and metabolomic information, start to make it feasible to assess a comprehensive spectrum of the biological activity of Se. Such nutrigenomic approaches may prove very sensitive biomarkers of optimal Se status at the individual or population level. The premature cessation of a major human Se intervention trial has led to considerable controversy as to the value of Se supplementation at the population level. New websites provide convenient links to current information on methodologies available for nutrigenetics and nutrigenomics. These new technologies will increasingly become an essential tool in optimising the level of Se and other micronutrients for optimal health, in individuals and in population groups. However, definitive proof of such effects will require very large collaborative studies, international agreement on study design and innovative approaches to data analysis.

  7. Fracture Phenomena in Amorphous Selenium

    DEFF Research Database (Denmark)

    Lindegaard-Andersen, Asger; Dahle, Birgit

    1966-01-01

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

  8. Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity.

    Science.gov (United States)

    Spiller, Henry A

    2018-05-01

    There is increasing evidence that the pathophysiological target of mercury is in fact selenium, rather than the covalent binding of mercury to sulfur in the body's ubiquitous sulfhydryl groups. The role of selenium in mercury poisoning is multifaceted, bidirectional, and central to understanding the target organ toxicity of mercury. An initial search was performed using Medline/PubMed, Toxline, Google Scholar, and Google for published work on mercury and selenium. These searches yielded 2018 citations. Publications that did not evaluate selenium status or evaluated environmental status (e.g., lake or ocean sediment) were excluded, leaving approximately 500 citations. This initial selection was scrutinized carefully and 117 of the most relevant and representative references were selected for use in this review. Binding of mercury to thiol/sulfhydryl groups: Mercury has a lower affinity for thiol groups and higher affinity for selenium containing groups by several orders of magnitude, allowing for binding in a multifaceted way. The established binding of mercury to thiol moieties appears to primarily involve the transport across membranes, tissue distribution, and enhanced excretion, but does not explain the oxidative stress, calcium dyshomeostasis, or specific organ injury seen with mercury. Effects of mercury on selenium and the role this plays in the pathophysiology of mercury toxicity: Mercury impairs control of intracellular redox homeostasis with subsequent increased intracellular oxidative stress. Recent work has provided convincing evidence that the primary cellular targets are the selenoproteins of the thioredoxin system (thioredoxin reductase 1 and thioredoxin reductase 2) and the glutathione-glutaredoxin system (glutathione peroxidase). Mercury binds to the selenium site on these proteins and permanently inhibits their function, disrupting the intracellular redox environment. A number of other important possible target selenoproteins have been identified

  9. SELENIUM ACCUMULATION BY BASIL PLANTS (OCINUM BASILICUM L.

    Directory of Open Access Journals (Sweden)

    N. A. Golubkina

    2014-01-01

    Full Text Available Selenium accumulation level in basil plants is investigated. A direct correlation between selenium concentration and essential oil content is demonstrated for basil and other aroma plants. No correlation is found between selenium and flavonoids.

  10. The essential toxin: The changing perception of selenium in environmental sciences

    NARCIS (Netherlands)

    Lenz, M.; Lens, P.N.L.

    2009-01-01

    During the last decades, the perception of selenium has undergone substantial changes. While its toxic effects were recognized causing hair and hoof loss in animals during the 1930s, its essential role in microbial, animal and human metabolism has been recognized later, i.e. with the discovery of

  11. Selenium Uptake and Volatilization by Marine Algae

    Science.gov (United States)

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

    2015-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-06-04

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

  13. Selenopeptides and elemental selenium in Thunbergia alata after exposure to selenite: quantification method for elemental selenium.

    Science.gov (United States)

    Aborode, Fatai Adigun; Raab, Andrea; Foster, Simon; Lombi, Enzo; Maher, William; Krupp, Eva M; Feldmann, Joerg

    2015-07-01

    Three month old Thunbergia alata were exposed for 13 days to 10 μM selenite to determine the biotransformation of selenite in their roots. Selenium in formic acid extracts (80 ± 3%) was present as selenopeptides with Se-S bonds and selenium-PC complexes (selenocysteinyl-2-3-dihydroxypropionyl-glutathione, seleno-phytochelatin2, seleno-di-glutathione). An analytical method using HPLC-ICPMS to detect and quantify elemental selenium in roots of T. alata plants using sodium sulfite to quantitatively transform elemental selenium to selenosulfate was also developed. Elemental selenium was determined as 18 ± 4% of the total selenium in the roots which was equivalent to the selenium not extracted using formic acid extraction. The results are in an agreement with the XAS measurements of the exposed roots which showed no occurrence of selenite or selenate but a mixture of selenocysteine and elemental selenium.

  14. Quantitative assessment of cerebral glucose metabolic rates after blood-brain barrier disruption induced by focused ultrasound using FDG-MicroPET.

    Science.gov (United States)

    Yang, Feng-Yi; Chang, Wen-Yuan; Chen, Jyh-Cheng; Lee, Lin-Chien; Hung, Yi-Shun

    2014-04-15

    The goal of this study was to evaluate the pharmacokinetics of (18)F-2-fluoro-2-deoxy-d-glucose ((18)F-FDG) and the expression of glucose transporter 1 (GLUT1) protein after blood-brain barrier (BBB) disruption of normal rat brains by focused ultrasound (FUS). After delivery of an intravenous bolus of ~37 MBq (1 mCi) (18)F-FDG, dynamic positron emission tomography scans were performed on rats with normal brains and those whose BBBs had been disrupted by FUS. Arterial blood sampling was collected throughout the scanning procedure. A 2-tissue compartmental model was used to estimate (18)F-FDG kinetic parameters in brain tissues. The rate constants Ki, K1, and k3 were assumed to characterize the uptake, transport, and hexokinase activity, respectively, of (18)F-FDG. The uptake of (18)F-FDG in brains significantly decreased immediately after the blood-brain barrier was disrupted. At the same time, the derived values of Ki, K1, and k3 for the sonicated brains were significantly lower than those for the control brains. In agreement with the reduction in glucose, Western blot analyses confirmed that focused ultrasound exposure significantly reduced the expression of GLUT1 protein in the brains. Furthermore, the effect of focused ultrasound on glucose uptake was transient and reversible 24h after sonication. Our results indicate that focused ultrasound may inhibit GLUT1 expression to decrease the glucose uptake in brain tissue during the period of BBB disruption. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Synergistic antifungal effect of chitosan-stabilized selenium nanoparticles synthesized by pulsed laser ablation in liquids against Candida albicans biofilms.

    Science.gov (United States)

    Lara, Humberto H; Guisbiers, Gregory; Mendoza, Jonathan; Mimun, Lawrence C; Vincent, Brandy A; Lopez-Ribot, Jose L; Nash, Kelly L

    2018-01-01

    Candida albicans is a major opportunistic fungal pathogen. One of the most important virulence factors that contribute to the pathogenesis of candidiasis is its ability to form biofilms. A key characteristic of Candida biofilms is their resistance to antifungal agents. Due to significant morbidity and mortality rates related to biofilm-associated drug resistance, there is an urgency to develop novel nanotechnology-based approaches preventing biofilm-related infections. In this study, we report, for the first time, the synthesis of selenium nanoparticles by irradiating selenium pellets by nanosecond pulsed laser ablation in liquid chitosan as a capping agent. Synergy of the fungicidal effect of selenium nanoparticles and chitosan was quantified by the combination index theorem of Chou-Talalay. This drug combination resulted in a potent fungicidal effect against a preformed C. albicans biofilm in a dose-response manner. By advanced electron microscopy techniques, we documented the adhesive and permeabilizing properties of chitosan, therefore allowing selenium nanoparticles to enter as the cell wall of the yeast became disrupted and distorted. Most importantly, we demonstrated a potent quantitative synergistic effect when compounds such as selenium and chitosan are combined. These chitosan-stabilized selenium nanoparticles could be used for ex vivo applications such as sterilizers for surfaces and biomedical devices.

  16. Review on Nano SeleniumProduced by Bacteria

    Directory of Open Access Journals (Sweden)

    LI Ji-xiang

    2014-12-01

    Full Text Available Selenium (Se is a kind of essential trace element for people and animal, while ionic state of selenium is toxic with high concentrations and will cause the selenium pollution. Nano-selenium is stable, nontoxic with higher biological activity. Application of bacteria reducing selenite or selenate to biological nano-selenium has great potential in selenium pollution control and nano-selenium production. This review summarizes the research progress of the red elemental nano-selenium reduced by bacteria including characteristics and application of nano-selenium, effects of carbon and nitrogen source, oxygen, temperature and pH in bacteria nano-selenium production, and molecular mechanisms of nano-selenium reduced by bacteria.

  17. Shape coexistence in selenium isotopes

    International Nuclear Information System (INIS)

    Liu Ying; Cao Zhongbin; Xu Furong

    2010-01-01

    Nuclear shape change and shape coexistence in the Selenium isotopes have been investigated by Total-Routhian-Surface (TRS) calculations. It is found that nuclear shapes vary significantly with increasing neutron number. The TRS calculations for the ground states of 66,72,92,94 Se isotopes show that both neutron-deficient and neutron-dripline Selenium isotopes have oblate and prolate shape coexistence. The cranking shell-model calculations for 72,94 Se give that prolate and oblate shape coexistence in low rotational frequency. However, oblate rotational bands disappear and prolate rotational bands become yrast bands with increasing rotational frequency, which is due to the intrusion of the g 9/2 orbitals. (authors)

  18. The chronic autoimmune thyroiditis quality of life selenium trial (CATALYST)

    DEFF Research Database (Denmark)

    Winther, Kristian Hillert; Watt, Torquil; Bjørner, Jakob Bue

    2014-01-01

    Patients with chronic autoimmune thyroiditis have impaired health-related quality of life. The thyroid gland has a high selenium concentration, and specific selenoprotein enzyme families are crucial to immune function, and catalyze thyroid hormone metabolism and redox processes in thyroid cells......-enriched yeast or matching placebo tablets daily for 12 months. The experimental supplement will be SelenoPrecise(R). The primary outcome is thyroid-related quality of life assessed by the Thyroid Patient-Reported Outcome (ThyPRO) questionnaire. Secondary outcomes include serum thyroid peroxidase antibody...

  19. Selenium determination by fluorimetric method

    International Nuclear Information System (INIS)

    Lavorenti, A.

    1981-01-01

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

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

    International Nuclear Information System (INIS)

    Porto, Barbara Abranches de Araujo

    2012-01-01

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

  1. Selenium Enrichment of Horticultural Crops.

    Science.gov (United States)

    Puccinelli, Martina; Malorgio, Fernando; Pezzarossa, Beatrice

    2017-06-04

    The ability of some crops to accumulate selenium (Se) is crucial for human nutrition and health. Selenium has been identified as a cofactor of the enzyme glutathione peroxidase, which is a catalyzer in the reduction of peroxides that can damage cells and tissues, and can act as an antioxidant. Plants are the first link in the food chain, which ends with humans. Increasing the Se quantity in plant products, including leafy and fruity vegetables, and fruit crops, without exceeding the toxic threshold, is thus a good way to increase animal and human Se intake, with positive effects on long-term health. In many Se-enriched plants, most Se is in its major organic form. Given that this form is more available to humans and more efficient in increasing the selenium content than inorganic forms, the consumption of Se-enriched plants appears to be beneficial. An antioxidant effect of Se has been detected in Se-enriched vegetables and fruit crops due to an improved antioxidative status and to a reduced biosynthesis of ethylene, which is the hormone with a primary role in plant senescence and fruit ripening. This thus highlights the possible positive effect of Se in preserving a longer shelf-life and longer-lasting quality.

  2. Selenium Enrichment of Horticultural Crops

    Directory of Open Access Journals (Sweden)

    Martina Puccinelli

    2017-06-01

    Full Text Available The ability of some crops to accumulate selenium (Se is crucial for human nutrition and health. Selenium has been identified as a cofactor of the enzyme glutathione peroxidase, which is a catalyzer in the reduction of peroxides that can damage cells and tissues, and can act as an antioxidant. Plants are the first link in the food chain, which ends with humans. Increasing the Se quantity in plant products, including leafy and fruity vegetables, and fruit crops, without exceeding the toxic threshold, is thus a good way to increase animal and human Se intake, with positive effects on long-term health. In many Se-enriched plants, most Se is in its major organic form. Given that this form is more available to humans and more efficient in increasing the selenium content than inorganic forms, the consumption of Se-enriched plants appears to be beneficial. An antioxidant effect of Se has been detected in Se-enriched vegetables and fruit crops due to an improved antioxidative status and to a reduced biosynthesis of ethylene, which is the hormone with a primary role in plant senescence and fruit ripening. This thus highlights the possible positive effect of Se in preserving a longer shelf-life and longer-lasting quality.

  3. Substituted 2-hydroxy-N-(arylalkyl)benzamide sensitizes cancer cells to metabolic stress by disrupting actin cytoskeleton and inhibiting autophagic flux

    Czech Academy of Sciences Publication Activity Database

    Pachnikova, G.; Uldrijan, S.; Imramovský, A.; Kryštof, Vladimír; Slaninová, I.

    2016-01-01

    Roč. 37, DEC (2016), s. 70-78 ISSN 0887-2333 Institutional support: RVO:61389030 Keywords : hepatocellular-carcinoma cells * sorafenib * apoptosis * death * maturation * membrane * melanoma * Actin * Autophagy * Melanoma * Metabolic stress * Sorafenib * Substituted 2-hydroxy-N-(arylalkyl)benzamide Subject RIV: CE - Biochemistry Impact factor: 2.866, year: 2016

  4. Selenium modulates MMP2 expression through the TGFβ1/Smad signalling pathway in human umbilical vein endothelial cells and rabbits following lipid disturbance.

    Science.gov (United States)

    Xu, Chenggui; Lu, Guihua; Li, Qinglang; Zhang, Juhong; Huang, Zhibin; Gao, Xiuren

    2017-07-01

    A high-fat diet is a major risk factor for coronary heart diseases. Matrix metalloprotease (MMP) expression is changed in many cardiovascular diseases. Selenium, which is an important trace element in animals, has a close relationship with cardiovascular diseases. The TGFβ1/Smad signalling pathway is ubiquitous in diverse tissues and cells, and it is also associated with the occurrence and development of cardiovascular diseases. Therefore, in this study, we aimed to determine selenium's effect on lipid metabolism, atherosclerotic plaque formation, and MMP2 expression, as well as the underlying functional mechanism. In vivo tests: 24 male New Zealand white rabbits were randomly divided into 4 groups: regular diet, high-fat diet, high-fat diet+selenium and regular diet+selenium groups. The high-fat diet induced the lipid disturbances of rabbits at week 12. Selenium supplementation lowered total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) levels (pSelenium supplementation also suppressed MMP2 over-expression in thoracic aortas. In vitro tests: Human umbilical vein endothelial cells (HUVECs) were treated with different concentrations of selenium or ox-LDL. Ox-LDL promoted MMP2 expression by increasing TGFβ1, pSmad2, pSmad3 and Smad3 expression (pSelenium attenuated MMP2 over-expression by regulating the TGFβ1/Smad signalling pathway. Selenium suppressed high-fat diet-induced MMP2 over-expression in vivo by improving lipid metabolism. In vitro, selenium attenuated MMP2 over-expression through the TGFβ1/Smad signalling pathway. Copyright © 2017 Elsevier GmbH. All rights reserved.

  5. Dietary incorporation of feedstuffs naturally high in organic selenium for racing pigeons (Columba livia): effects on plasma antioxidant markers after a standardised simulation of a flying effort.

    Science.gov (United States)

    Schoonheere, N; Dotreppe, O; Pincemail, J; Istasse, L; Hornick, J L

    2009-06-01

    Selenium is a trace element of importance for animal health. It is essential for adequate functioning of many enzymes such as, the antioxidant enzyme, glutathione peroxidase, which protects the cell against free radicals. A muscular effort induces a rise in reactive oxygen species production which, in turn, can generate an oxidative stress. Two groups of eight racing pigeons were fed respectively with a diet containing 30.3 (control group) and 195.3 (selenium group) microg selenium/kg diet. The pigeons were submitted to a standardised simulation of a flying effort during 2 h. Blood was taken before and after the effort to measure antioxidant markers and blood parameters related to muscle metabolism. Plasma selenium concentration and glutathione peroxidase activity were significantly higher in the selenium group. There were no significant differences for the other measured parameters. As a consequence of the effort, the pigeons of the selenium group showed a higher increase of glutathione peroxidase activity and a smaller increase of plasma lactate concentration. Variations because of the effort in the other markers were not significantly different between the two groups. It is concluded that the selenium status was improved with the feeding of feedstuffs high in Selenium.

  6. Sustainable Disruptions

    DEFF Research Database (Denmark)

    Friis, Silje Alberthe Kamille; Kjær, Lykke Bloch

    2016-01-01

    Since 2012 the Sustainable Disruptions (SD) project at the Laboratory for Sustainability at Design School Kolding (DK) has developed and tested a set of design thinking tools, specifically targeting the barriers to economically, socially, and environmentally sustainable business development....... The tools have been applied in practice in collaboration with 11 small and medium sized companies (SMEs). The study investigates these approaches to further understand how design thinking can contribute to sustainable transition in a business context. The study and the findings are relevant to organizations...... invested in the issue of sustainable business development, in particular the leaders and employees of SMEs, but also to design education seeking new ways to consciously handle and teach the complexity inherent in sustainable transformation. Findings indicate that the SD design thinking approach contributes...

  7. Selenium deficiency occurs in some patients with moderate-to-severe cirrhosis and can be corrected by administration of selenate but not selenomethionine: a randomized controlled trial123

    Science.gov (United States)

    Burk, Raymond F; Hill, Kristina E; Motley, Amy K; Byrne, Daniel W; Norsworthy, Brooke K

    2015-01-01

    Background: Selenomethionine, which is the principal dietary form of selenium, is metabolized by the liver to selenide, which is the form of the element required for the synthesis of selenoproteins. The liver synthesizes selenium-rich selenoprotein P (SEPP1) and secretes it into the plasma to supply extrahepatic tissues with selenium. Objectives: We conducted a randomized controlled trial to determine whether cirrhosis is associated with functional selenium deficiency (the lack of selenium for the process of selenoprotein synthesis even though selenium intake is not limited) and, if it is, whether the deficiency is associated with impairment of selenomethionine metabolism. Design: Patients with Child-Pugh (C-P) classes A, B, and C (mild, moderate, and severe, respectively) cirrhosis were supplemented with a placebo or supranutritional amounts of selenium as selenate (200 or 400 μg/d) or as selenomethionine (200 μg/d) for 4 wk. Plasma SEPP1 concentration and glutathione peroxidase (GPX) activity, the latter due largely to the selenoprotein GPX3 secreted by the kidneys, were measured before and after supplementation. Results: GPX activity was increased more by both doses of selenate than by the placebo in C-P class B patients. The activity was not increased more by selenomethionine supplementation than by the placebo in C-P class B patients. Plasma selenium was increased more by 400 μg Se as selenate than by the placebo in C-P class C patients. Within the groups who responded to selenate, there was a considerable variation in responses. Conclusion: These results indicate that severe cirrhosis causes mild functional selenium deficiency in some patients that is associated with impaired metabolism of selenomethionine. This trial was registered at clinicaltrials.gov as NCT00271245. PMID:26468123

  8. Understanding selenium biogeochemistry in engineered ecosystems

    NARCIS (Netherlands)

    Jain, Rohan; Hullebusch, Van Eric D.; Lenz, Markus; Farges, François

    2017-01-01

    Selenium is used extensively in many industries, and it is necessary for human nutrition. On the other hand, it is also toxic at slightly elevated concentrations. With the advent of industrialisation, selenium concentrations in the environment due to anthropogenic activities have increased.

  9. Selenium in human milk: An Australian study

    International Nuclear Information System (INIS)

    Cumming, F.J.; Fardy, J.J.; Woodward, D.R.

    1991-01-01

    The aims of this Australian study were to determine (total) selenium concentration in breast milk and in maternal blood, and to assess the relationship between the two. The authors also aimed to assess the infants' selenium intake. Twenty lactating women from Brisbane (Queensland) participated in the study, at 6-12 weeks post-partum. Small samples (approximately 10 ml) of breast-milk were manually expressed at the beginning and end of a mid-morning feed, from the first breast offered at that feed. Venous blood samples (10 ml) were also collected from the mothers. Milk and blood samples were analyzed by neutron activation analysis. Babies' milk intake over a 24-hour period was estimated using a modified test-weighing technique. Infant selenium intakes were calculated directly for each infant, using his/her mother's milk selenium level and his/her own 24-hour breast milk intake. The mean selenium concentration in maternal blood was 101 (±SD 19) ng/g and in maternal serum 81 (±15) ng/g. Breast milk selenium concentrations (11.9 ± 3.5 ng/g) were fairly low by international standards. There was no correlation between selenium concentrations in milk and blood (or serum). The infants' 24-hour breast-milk intakes were 856 ± 172 g, and their selenium intakes were 10.7 ± 4.1 μg per day

  10. Learning selenium testing tools with Python

    CERN Document Server

    Gundecha, Unmesh

    2014-01-01

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

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  12. Resistance, accumulation and transformation of selenium by the cyanobacterium Synechocystis sp. PCC 6803 after exposure to inorganic SeVI or SeIV

    International Nuclear Information System (INIS)

    Gouget, B.; Avoscan, L.; Collins, R.; Carriere, M.; Sarret, G.

    2005-01-01

    Our purpose was to investigate the ability of Synechocystis sp. PCC 6803, a photosynthetic prokaryote isolated from fresh water, to resist, incorporate and reduce the oxidized forms of selenium including selenite and selenate, the major selenium species present in aquatic systems. Selenium speciation and the chemical intermediates during selenium transformation were determined by X-ray absorption near edge structure (XANES) spectroscopy. The possible internalisation pathways involving selenium and the metabolic fate of selenate and selenite were examined. Selenate metabolism seemed to proceed via the sulfate reduction pathway resulting in the formation of the R-Se-H, R-Se-R and R-Se-Se-R species. The transformation of selenate to toxic amino acids may explain the high sensitivity of Synechocystis to selenate. Several mechanisms of selenium reduction seem to complete during selenite assimilation. A specific mechanism may transform internalised selenite into selenide and, subsequently induce the biosynthesis of selenoproteins. A non-specific mechanism may interfere with thiols, such as glutathione in the cell cytoplasm, or with proteins in the periplasm of the bacteria, notably thioredoxins. Several hypotheses concerning the complex transformation of selenium in Synechocystis could therefore be proposed. (orig.)

  13. Role of selenium toxicity and oxidative stress in aquatic birds

    Science.gov (United States)

    Hoffman, D.J.

    2002-01-01

    Adverse effects of selenium (Se) in wild aquatic birds have been documented as a consequence of pollution of the aquatic environment by subsurface agricultural drainwater and other sources. These effects include mortality, impaired reproduction with teratogenesis, reduced growth, histopathological lesions and alterations in hepatic glutathione metabolism. A review is provided, relating adverse biological effects of Se in aquatic birds to altered glutathione metabolism and oxidative stress. Laboratory studies, mainly with an organic form of Se, selenomethionine, have revealed oxidative stress in different stages of the mallard (Anas platyrhynchos) life cycle. As dietary and tissue concentrations of Se increase, increases in plasma and hepatic GSH peroxidase activities occur, followed by dose-dependent increases in the ratio of hepatic oxidized to reduced glutathione (GSSG:GSH) and ultimately hepatic lipid peroxidation measured as an increase in thiobarbituric acid reactive substances (TBARS). One or more of these oxidative effects were associated with teratogenesis (4.6 ppm wet weight Se in eggs), reduced growth in ducklings (15 ppm Se in liver), diminished immune function (5 ppm Se in liver) and histopathological lesions (29 ppm Se in liver) in adults. Manifestations of Serelated effects on glutathione metabolism were also apparent in field studies in seven species of aquatic birds. Reduced growth and possibly immune function but increased liver:body weight and hepatic GSSG:GSH ratios were apparent in American avocet (Recurvirostra americana) hatchlings from eggs containing 9 ppm Se. In blacknecked stilts (Himantopus mexicanus), which contained somewhat lower Se concentrations, a decrease in hepatic GSH was apparent with few other effects. In adult American coots (Fulica americana), signs of Se toxicosis included emaciation, abnormal feather loss and histopathological lesions. Mean liver concentrations of 28 ppm Se (ww) in the coots were associated with elevated

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

    Science.gov (United States)

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

    2012-01-01

    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. 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. 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. 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.

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

    Directory of Open Access Journals (Sweden)

    Ingibjorg Gunnarsdottir

    2012-08-01

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

  16. Selenium accumulation in plants--phytotechnological applications and ecological implications.

    Science.gov (United States)

    Valdez Barillas, José Rodolfo; Quinn, Colin F; Pilon-Smits, Elizabeth A H

    2011-01-01

    Selenium (Se) is an essential trace element for many organisms including humans, yet toxic at higher levels. Both Se deficiency and toxicity are problems worldwide. Since plants readily accumulate and volatilize Se, they may be used both as a source of dietary Se and for removing excess Se from the environment. Plant species differ in their capacity to metabolize and accumulate Se, from non-Se accumulators ( 1,000 mg Se/kg DW). Here we review plant mechanisms of Se metabolism in these various plant types. We also summarize results from genetic engineering that have led to enhanced plant Se accumulation, volatilization, and/or tolerance, including field studies. Before using Se-accumulating plants at a large scale we need to evaluate the ecological implications. Research so far indicates that plant Se accumulation significantly affects the plant's ecological interactions below and above ground. Selenium canprotect plants from fungal pathogens and from a variety of invertebrate and vertebrate herbivores, due to both deterrence and toxicity. However, specialist (Se-tolerant herbivores), detritivores and endophytes appear to utilize Se hyperaccumulator plants as a resource. These findings are relevant for managing phytoremediation of Se and similar elements.

  17. Selenium-75-labelled foliate compounds

    International Nuclear Information System (INIS)

    1974-01-01

    A saturation method to analyze a foliate is presented; it uses competitive reaction of the compound to be measured and of a radioactive-labelled version of this compound with a reagent specific to this compound present in insufficient quantity to combine with the whole of the compound and its labelled version, separation of the bound compound from its non-bound homologue and measurement of the radioactivity concentration in the bound compound, the non-bound compound or both. The radioactive isotope used in the labelled foliate is selenium 75 [fr

  18. Dietary selenium in the Glasgow area

    International Nuclear Information System (INIS)

    Cross, J.D.; Raie, R.M.; Smith, H.

    1978-01-01

    A typical diet for people in the Glasgow area is analysed and an estimate is made of the daily intake of selenium for the average person (234 μg). Meat, poultry and bread products contribute 65% of the total selenium consumed. There is a significant loss of selenium on cooking but the concentration in the diet is high compared with the estimated requirement. Selenium levels in prepared infant foods, artificial milk and natural milk are reported. Those infants on artificial milk feeds have a selenium intake equivalent to that of adults (3 μg/kg) while those on natural milk or prepared infant foods have an intake of 6 μg/kg. Adult and infant tissue selenium levels are established and are shown to be in equilibrium with the diet. There is no concentration in man as a result of his position at the top of the food chain. Sudden infant death cannot be related to selenium levels in human tissue or diet. (author)

  19. In Situ Immobilization of Selenium in Sediment

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Robert C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stewart, Thomas Austin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    This project focused on the use of a sorbent, carbonated apatite, to immobilize selenium in the environment. It is know that apatite will sorb selenium and based on the mechanism of sorption it is theorized that carbonated apatite will be more effective that pure apatite. Immobilization of selenium in the environment is through the use of a sorbent in a permeable reactive barrier (PRB). A PRB can be constructed by trenching and backfill with the sorbent or in the case of apatite as the sorbent formed in situ using the apatite forming solution of Moore (2003, 2004). There is very little data on selenium sorption by carbonated apatite in the literature. Therefore, in this work, the basic sorptive properties of carbonated apatite were investigated. Carbonated apatite was synthesized by a precipitation method and characterized. Batch selenium kinetic and equilibrium experiments were performed. The results indicate the carbonated apatite contained 9.4% carbonate and uptake of selenium as selenite was rapid; 5 hours for complete uptake of selenium vs. more than 100 hours for pure hydroxyapatite reported in the literature. Additionally, the carbonated apatite exhibited significantly higher distribution coefficients in equilibrium experiments than pure apatite under similar experimental conditions. The next phase of this work will be to seek additional funds to continue the research with the goal of eventually demonstrating the technology in a field application.

  20. Mitral cells of the olfactory bulb perform metabolic sensing and are disrupted by obesity at the level of the Kv1.3 ion channel.

    Directory of Open Access Journals (Sweden)

    Debra Ann Fadool

    Full Text Available Sixty-five percent of Americans are over-weight. While the neuroendocrine controls of energy homeostasis are well known, how sensory systems respond to and are impacted by obesity is scantily understood. The main accepted function of the olfactory system is to provide an internal depiction of our external chemical environment, starting from the detection of chemosensory cues. We hypothesized that the system additionally functions to encode internal chemistry via the detection of chemicals that are important indicators of metabolic state. We here uncovered that the olfactory bulb (OB subserves as an internal sensor of metabolism via insulin-induced modulation of the potassium channel Kv1.3. Using an adult slice preparation of the olfactory bulb, we found that evoked neural activity in Kv1.3-expressing mitral cells is enhanced following acute insulin application. Insulin mediated changes in mitral cell excitability are predominantly due to the modulation of Kv1.3 channels as evidenced by the lack of effect in slices from Kv1.3-null mice. Moreover, a selective Kv1.3 peptide blocker (ShK186 inhibits more than 80% of the outward current in parallel voltage-clamp studies, whereby insulin significantly decreases the peak current magnitude without altering the kinetics of inactivation or deactivation. Mice that were chronically administered insulin using intranasal delivery approaches exhibited either an elevation in basal firing frequency or fired a single cluster of action potentials. Following chronic administration of the hormone, mitral cells were inhibited by application of acute insulin rather than excited. Mice made obese through a diet of ∼32% fat exhibited prominent changes in mitral cell action potential shape and clustering behavior, whereby the subsequent response to acute insulin stimulation was either attenuated or completely absent. Our results implicate an inappropriate neural function of olfactory sensors following exposure to

  1. Distribution and mode of occurrence of selenium in US coals

    Science.gov (United States)

    Coleman, L.; Bragg, L.J.; Finkelman, R.B.

    1993-01-01

    Selenium excess and deficiency have been established as the cause of various health problems in man and animals. Combustion of fossil fuels, especially coal, may be a major source of the anthropogenic introduction of selenium in the environment. Coal is enriched in selenium relative to selenium's concentration in most other rocks and relative to selenium in the Earth's crust. Data from almost 9,000 coal samples have been used to determine the concentration and distribution of selenium in US coals. The geometric mean concentration of selenium in US coal is 1.7 ppm. The highest mean selenium value (geometric mean 4.7 ppm) is in the Texas Region. Atlantic Coast (Virginia and North Carolina) and Alaska coals have the lowest geometric means (0.2 and 0.42 ppm, respectively). All western coal regions have mean selenium concentrations of less than 2.0 ppm. In contrast, all coal basins east of the Rocky Mountains (except for several small basins in Rhode Island, Virginia, and North Carolina) have mean selenium values of 1.9 or greater. Generally, variations in selenium concentration do not correlate with variations in ash yield, pyritic sulphur, or organic sulphur concentrations. This may be the result of multiple sources of selenium; however, in some non-marine basins with restricted sources of selenium, selenium has positive correlations with other coal quality parameters. Selenium occurs in several forms in coal but appears to be chiefly associated with the organic fraction, probably substituting for organic sulphur. Other important forms of selenium in coal are selenium-bearing pyrite, selenium-bearing galena, and lead selenide (clausthalite). Water-soluble and ion-exchangeable selenium also have been reported. ?? 1993 Copyright Science and Technology Letters.

  2. Lack of mitochondrial MutS homolog 1 in Toxoplasma gondii disrupts maintenance and fidelity of mitochondrial DNA and reveals metabolic plasticity.

    Directory of Open Access Journals (Sweden)

    Tamila Garbuz

    Full Text Available The importance of maintaining the fidelity of the mitochondrial genome is underscored by the presence of various repair pathways within this organelle. Presumably, the repair of mitochondrial DNA would be of particular importance in organisms that possess only a single mitochondrion, like the human pathogens Plasmodium falciparum and Toxoplasma gondii. Understanding the machinery that maintains mitochondrial DNA in these parasites is of particular relevance, as mitochondrial function is a validated and effective target for anti-parasitic drugs. We previously determined that the Toxoplasma MutS homolog TgMSH1 localizes to the mitochondrion. MutS homologs are key components of the nuclear mismatch repair system in mammalian cells, and both yeast and plants possess MutS homologs that localize to the mitochondria where they regulate DNA stability. Here we show that the lack of TgMSH1 results in accumulation of single nucleotide variations in mitochondrial DNA and a reduction in mitochondrial DNA content. Additionally, parasites lacking TgMSH1 function can survive treatment with the cytochrome b inhibitor atovaquone. While the Tgmsh1 knockout strain has several missense mutations in cytochrome b, none affect amino acids known to be determinants of atovaquone sensitivity and atovaquone is still able to inhibit electron transport in the Tgmsh1 mutants. Furthermore, culture of Tgmsh1 mutant in the presence atovaquone leads to parasites with enhanced atovaquone resistance and complete shutdown of respiration. Thus, parasites lacking TgMSH1 overcome the disruption of mitochondrial DNA by adapting their physiology allowing them to forgo the need for oxidative phosphorylation. Consistent with this idea, the Tgmsh1 mutant is resistant to mitochondrial inhibitors with diverse targets and exhibits reduced ability to grow in the absence of glucose. This work shows TgMSH1 as critical for the maintenance and fidelity of the mitochondrial DNA in Toxoplasma

  3. Endocrine Disrupting Chemicals (EDCs)

    Science.gov (United States)

    ... Center Pacientes y Cuidadores Hormones and Health The Endocrine System Hormones Endocrine Disrupting Chemicals (EDCs) Steroid and Hormone ... Hormones and Health › Endocrine Disrupting Chemicals (EDCs) The Endocrine System Hormones Endocrine Disrupting Chemicals (EDCs) EDCs Myth vs. ...

  4. Selenium supplementation for Hashimoto's thyroiditis.

    Science.gov (United States)

    van Zuuren, Esther J; Albusta, Amira Y; Fedorowicz, Zbys; Carter, Ben; Pijl, Hanno

    2013-06-06

    Hashimoto's thyroiditis is a common auto-immune disorder. The most common presenting symptoms may include anxiety, negative mood, depression, dry skin, cold intolerance, puffy eyes, muscle cramps and fatigue, deep voice, constipation, slow thinking and poor memory. Clinical manifestations of the disease are defined primarily by low levels of thyroid hormones; therefore it is treated by hormone replacement therapy, which usually consists of levothyroxine (LT4). Selenium might reduce antibody levels and result in a decreased dosage of LT4 and may provide other beneficial effects (e.g. on mood and health-related quality of life). To assess the effects of selenium supplementation on Hashimoto's thyroiditis. We searched the following databases up to 2 October 2012: CENTRAL in The Cochrane Library (2012, Issue 10), MEDLINE, EMBASE, and Web of Science; we also screened reference lists of included studies and searched several online trial registries for ongoing trials (5 November 2012). Randomised controlled clinical trials that assessed the effects of selenium supplementation for adults diagnosed with Hashimoto's thyroiditis. Study selection, data extraction, assessment of risk of bias, and analyses were carried out by two independent review authors. We assessed the quality of the evidence of included studies using GRADE. We were unable to conduct a meta-analysis because clinical heterogeneity between interventions that were investigated is substantial. Four studies at unclear to high risk of bias comprising 463 participants were included. The mean study duration was 7.5 months (range 3 to 18 months). One of our primary outcomes-'change from baseline in health related quality of life'-and two of our secondary outcomes-'change from baseline in LT4 replacement dosage at end of the study' and 'economic costs'-were not assessed in any of the studies. One study at high risk of bias showed statistically significant improvement in subjective well-being with sodium

  5. Recent trends in selenium regulation and management

    International Nuclear Information System (INIS)

    Sobolewski, A.

    2010-01-01

    Selenium is a contaminant encountered at uranium mines. When discharged into water, it can build up in the food chain and become toxic to egg-laying fish and shorebirds. This presentation reviews recent developments in its regulation, management and treatment. Selenium will soon be regulated on the basis of its concentration in fish or bird eggs, not its dissolved concentrations, which challenges managers trying to establish acceptable discharge limits. Information supporting this change will be discussed. Recent developments to manage and treat selenium will also be reviewed, emphasizing new chemical and biological treatment processes applicable at uranium mines and mill sites. (author)

  6. Nuclear transformations studies in selenium isotopes

    International Nuclear Information System (INIS)

    Lopez M, B.E.

    1976-01-01

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

  7. Selenium content of foods purchased or produced in Ohio.

    Science.gov (United States)

    Snook, J T; Kinsey, D; Palmquist, D L; DeLany, J P; Vivian, V M; Moxon, A L

    1987-06-01

    Approximately 450 samples of about 100 types of foods consumed by rural and urban Ohioans were analyzed for selenium. Meat, dairy products, eggs, and grain products produced in Ohio have considerably lower selenium content than corresponding products produced in high selenium areas, such as South Dakota. Retail Ohio foods with interregional distribution tended to be higher in selenium content than corresponding foods produced in Ohio. Best sources of selenium in Ohio foods commonly consumed were meat and pasta products. Poor sources of selenium were fruits, most vegetables, candies, sweeteners, and alcoholic and nonalcoholic beverages. Establishment of an accurate data base for selenium depends on knowledge of the interregional distribution of foods, the selenium content of foods at their production site, and the selenium content of foods with wide local distribution.

  8. THE IMPACT OF SELENIUM STATUS ON THE METABLISM AND DISPOSITION OF ARSENIC AND ITS IMPLICATIONS FOR EPIDEMIOLOGIC INVESTIGATIONS

    Science.gov (United States)

    The Impact of Selenium Status on the Metabolism and Disposition of Arsenic and Its Implications for Epidemiologic InvestigationsE. M. Kenyon1*, M.F. Hughes1, L.M. Del Razo2, and O.A. Levander31Office of Research and Development, Experimental Toxicology Division, N...

  9. Selenium hyperaccumulation offers protection from cell disruptor herbivores

    Directory of Open Access Journals (Sweden)

    Quinn Colin F

    2010-08-01

    Full Text Available Abstract Background Hyperaccumulation, the rare capacity of certain plant species to accumulate toxic trace elements to levels several orders of magnitude higher than other species growing on the same site, is thought to be an elemental defense mechanism against herbivores and pathogens. Previous research has shown that selenium (Se hyperaccumulation protects plants from a variety of herbivores and pathogens. Selenium hyperaccumulating plants sequester Se in discrete locations in the leaf periphery, making them potentially more susceptible to some herbivore feeding modes than others. In this study we investigate the protective function of Se in the Se hyperaccumulators Stanleya pinnata and Astragalus bisulcatus against two cell disrupting herbivores, the western flower thrips (Frankliniella occidentalis and the two-spotted spider mite (Tetranychus urticae. Results Astragalus bisulcatus and S. pinnata with high Se concentrations (greater than 650 mg Se kg-1 were less subject to thrips herbivory than plants with low Se levels (less than 150 mg Se kg-1. Furthermore, in plants containing elevated Se levels, leaves with higher concentrations of Se suffered less herbivory than leaves with less Se. Spider mites also preferred to feed on low-Se A. bisulcatus and S. pinnata plants rather than high-Se plants. Spider mite populations on A. bisulcatus decreased after plants were given a higher concentration of Se. Interestingly, spider mites could colonize A. bisulcatus plants containing up to 200 mg Se kg-1 dry weight, concentrations which are toxic to many other herbivores. Selenium distribution and speciation studies using micro-focused X-ray fluorescence (μXRF mapping and Se K-edge X-ray absorption spectroscopy revealed that the spider mites accumulated primarily methylselenocysteine, the relatively non-toxic form of Se that is also the predominant form of Se in hyperaccumulators. Conclusions This is the first reported study investigating the

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

    Science.gov (United States)

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

    2016-01-01

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

  11. Selenium supplementation induces mitochondrial biogenesis in trophoblasts

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

    Roč. 36, č. 8 (2015), s. 363-369 ISSN 0143-4004 Institutional support: RVO:86652036 Keywords : Selenium * Reactive oxygen species * Mitochondrial biogenesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.972, year: 2015

  12. Biofortification and phytoremediation of selenium in China

    Science.gov (United States)

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

  13. Ameliorative effects of selenium and zinc

    African Journals Online (AJOL)

    Methidathion-induced hematological, biochemical and hepatohistological alterations in rat: Ameliorative effects of selenium and zinc. L Barkat, A Boumendjel, C Abdennour, MS Boulakoud, A El Feki, M Messarah ...

  14. Selenium supplementation for critically ill adults

    DEFF Research Database (Denmark)

    Allingstrup, Mikkel; Afshari, Arash

    2015-01-01

    BACKGROUND: Selenium is a trace mineral essential to health and has an important role in immunity, defence against tissue damage and thyroid function. Improving selenium status could help protect against overwhelming tissue damage and infection in critically ill adults. This Cochrane review...... was originally published in 2004 updated in 2007 and again 2015. OBJECTIVES: The primary objective was to examine the effect of nutrition supplemented with selenium or ebselen on mortality in critically ill patients.The secondary objective was to examine the relationship between selenium or ebselen...... supplementation and number of infections, duration of mechanical ventilation, length of intensive care unit stay and length of hospital stay. SEARCH METHODS: In this update, we searched the current issue of the Cochrane Central Register of Controlled Trials, the Cochrane Library (2014, Issue 5); MEDLINE (Ovid SP...

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

    International Nuclear Information System (INIS)

    Zhang Jinsong; Wang Huali; Yu Hanqing

    2007-01-01

    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

  16. Selenium nanoparticles: potential in cancer gene and drug delivery.

    Science.gov (United States)

    Maiyo, Fiona; Singh, Moganavelli

    2017-05-01

    In recent decades, colloidal selenium nanoparticles have emerged as exceptional selenium species with reported chemopreventative and therapeutic properties. This has sparked widespread interest in their use as a carrier of therapeutic agents with results displaying synergistic effects of selenium with its therapeutic cargo and improved anticancer activity. Functionalization remains a critical step in selenium nanoparticles' development for application in gene or drug delivery. In this review, we highlight recent developments in the synthesis and functionalization strategies of selenium nanoparticles used in cancer drug and gene delivery systems. We also provide an update of recent preclinical studies utilizing selenium nanoparticles in cancer therapeutics.

  17. Is selenium supplementation in autoimmune thyroid diseases justified?

    DEFF Research Database (Denmark)

    Winther, Kristian H.; Bonnema, Steen; Hegedüs, Laszlo

    2017-01-01

    PURPOSE OF REVIEW: This review provides an appraisal of recent evidence for or against selenium supplementation in patients with autoimmune thyroid diseases, and discusses possible effect mechanisms. RECENT FINDINGS: Epidemiological data suggest an increased prevalence of autoimmune thyroid...... diseases under conditions of low dietary selenium intake. Two systematic reviews have evaluated controlled trials among patients with autoimmune thyroiditis and report that selenium supplementation decreases circulating thyroid autoantibodies. The immunomodulatory effects of selenium might involve reducing...... proinflammatory cytokine release. However, clinically relevant effects of selenium supplementation, including improvement in quality of life, are more elusive. In Graves’ disease, some, but not all, trials indicate that adjuvant selenium supplementation enhances the restoration of biochemical euthyroidism...

  18. Production of selenium-72 and arsenic-72

    Science.gov (United States)

    Phillips, D.R.

    1994-12-06

    Methods and apparatus are described for producing selenium-72, separating it from its daughter isotope arsenic-72, and generating multiple portions of a solution containing arsenic-72 from a reusable parent substance comprised of selenium-72. The invention provides apparatus which can be located at a site where arsenic-72 is used, for purposes such as PET imaging, to produce arsenic-72 as needed, since the half-life of arsenic-72 is very short. 2 figures.

  19. The role of selenium in predicting preeclampsia

    Directory of Open Access Journals (Sweden)

    Z Ghaemi

    2013-10-01

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

  20. Selenium and tellurium reagents in organic synthesis

    International Nuclear Information System (INIS)

    Comasseto, J.V.

    1984-01-01

    A review of the contribution of the University of Sao Paulo (SP, Brazil) to the organic synthesis of selenium and tellurium reagents is made. Major reactions amoung selenium compounds and insaturated substrates, phosphorus, ester enolates as well as the use of phase transference catalysed reactions to produce arylselenolate are described. For tellurium, interactions of its compounds with organic substrates and reactive intermediates (e.g. benzino diazomethane) are reported. (C.L.B.) [pt

  1. Determinants of selenium in the toenail biomonitor

    International Nuclear Information System (INIS)

    Morris, J.S.; Spate, V.L.; Ngwenyama, R.A.

    2006-01-01

    The evaluation of human nails as a measure of selenium intake and to assess selenium status in critical tissues is now being used routinely to investigate hypotheses relating selenium status to chronic disease, especially cancer. In this study we report on our observations of the major determinants of toenail selenium concentrations. Toenail specimens (3575) were, under a protocol we provided, self-collected by adult females (1940, 54.3%) and males (1635, 45.7%) living in 111 of Missouri's 114 counties. The health-conscious participants ranged in age from 18 to 94 years with means of 53.7±14.1 and 56.4±14.2 years for females and males, respectively. Selenium supplement use was over represented, 39.1% and 42.7%, and smoking was under represented, 7.5% and 7.8%, for females and males, respectively. The major determinants of toenail selenium concentration were supplement use, sex and cigarette smoking. We found no overall correlations with age, body mass index or diet selection. (author)

  2. Evaluation of iron, zinc, copper, manganese and selenium in oral hospital diets.

    OpenAIRE

    Moreira, Daniele Caroline Faria; Sá, Júlia Sommerlatte Manzoli de; Cerqueira, Isabel B.; Oliveira, Ana P. F. de; Morgano, Marcelo Antonio; Quintaes, Késia Diego

    2013-01-01

    Background & aims: Many trace elements are nutrients essential to humans, acting in the metabolism as constituents or as enzymatic co-factors. The iron, zinc, copper, manganese and selenium contents of hospital diets (regular, blend and soft) and of oral food complement (OFC) were determined, evaluating the adequacy of each element in relation to the nutritional recommendations (DRIs) and the percent contribution alone and with OFC. Methods: Duplicate samples were taken of six daily meals ...

  3. Dietary Selenium and Human Health

    Directory of Open Access Journals (Sweden)

    Lutz Schomburg

    2016-12-01

    Full Text Available Next year (2017, the micronutrient Selenium (Se is celebrating its birthday—i.e., 200 years after first being identified by the Swedish chemist Jöns Jakob Berzelius. Despite its impressive age, research into the functions of this essential trace element is very alive and reaching out for new horizons. This special issue presents some recent fascinating, exciting, and promising developments in Se research in the form of eight original contributions and seven review articles. Collectively, aspects of Se supply, biochemical, physiological, and chemotherapeutic effects, and geobiological interactions are covered by leading scientists in the areas of nutritional, basic, and clinical research. It is obvious from the contributions that the bicentennial anniversary will celebrate a micronutrient still in its infancy with respect to being understood in terms of its biomedical importance.

  4. Selenium Se and tellurium Te

    International Nuclear Information System (INIS)

    Busev, A.I.; Tiptsova, V.G.; Ivanov, V.M.

    1978-01-01

    The basic methods for determining selenium and tellurium in various objects are presented. The bichromatometric determination of Te in cadmium, zinc and mercury tellurides is based on oxidation of Te(4) to (6) in H 2 SO 4 with potassium bichromate. In steels, Te is determined photometrically with the aid of KI. The determination is hindered by Fe(3), Cu(2), Bi(3) and Se(4) ions, which must be separated. The extraction-photometric determination of Te in native sulfur is carried out with the aid of 5-mercapto-3-(naphthyl-2)-1,3,4-thiadiazolthione-2 (pH=4.8-5.0). The dyed complex is readily extracted with chloroform and benzene. The spectrophotometric determination of Te in selenium is performed with the aid of 3,5-diphenylpyrazoline-1-dithiocarbamate of sodium. Te is determined in commercial indium, arsenic and their semiconductor compounds photometrically with the aid of copper diethyldithiocarbamate. The method permits determining 5x10 -5 % Te in a weighed amount of 0.5 g. The chloride complex of Te(4) with diantipyriodolpropylmethane is quantitatively extracted with dichloroethane from hydrochloric acid solutions. Thus, any amounts of Te can be separated from Se and determined photometrically. The extraction-photometric determination of Te in commercial lead and bismuth is carried out with the aid of pyrazolone derivatives, in commercial copper with the aid of diantipyridolpropylmethane, and in ores (more than 0.01% Te) with the aid of bismuthol 2. Also described is the extraction-polarographic determination of Te in sulfide ores

  5. Thin film solar cells by selenization sulfurization using diethyl selenium as a selenium precursor

    Science.gov (United States)

    Dhere, Neelkanth G.; Kadam, Ankur A.

    2009-12-15

    A method of forming a CIGSS absorber layer includes the steps of providing a metal precursor, and selenizing the metal precursor using diethyl selenium to form a selenized metal precursor layer (CIGSS absorber layer). A high efficiency solar cell includes a CIGSS absorber layer formed by a process including selenizing a metal precursor using diethyl selenium to form the CIGSS absorber layer.

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

    Energy Technology Data Exchange (ETDEWEB)

    Prokisch, J; Sztrik, A; Babka, B; Zommara, M; Daroczi, L [Debrecen University, Centre for Agricultural Sciences and Engineering, Debrecen (Hungary). Institute of Bio- and Environmental Energetics

    2009-07-01

    Complete text of publication follows. We have found that several species of probiotic bacteria also used in food industry for making yogurts is capable of producing spherical elemental selenium nanospheres having an average diameter in the range of 50-500 nm when 1-1000 mg/L selenium was added to the medium in the form of selenite ions. Elemental selenium produced thereby has a high degree of purity, is spherical, and its size and crystalline form depends on the bacterium species applied. We have found that some species of the probiotic yogurt bacteria (e.g. Bifidobacterium bifidum or Bifidobacterium longum) are capable of producing the grey crystalline form of elemental selenium which is so far unprecedented in the art for any bacteria capable of producing elemental selenium nanoparticles. Our finding, therefore, enables the first time the development of economical industrial bacterial fermentation based processes for the production of a high quality elemental selenium material comprising uniformly sized grey or red nanospheres having an average diameter in the range of 50-500 nm. The size and the crystalline form of the produced nanosized (50-500 nm) spherical particles is defined by the selected microorganism. This genetic pre-determination result in reproducible production of a material having individual characteristics which can be used in numerous fields of industry and research. The produced nano selenium could be a good raw material for a production of certified reference materials. The measurement of the produced elemental nanoselenium is a new challenge for the speciation analysis. A sample preparation and measurement method was developed and investigated for the analysis of different selenium forms by HPLC-AFS system. The atomic fluorescence (AFS) was a reliable and simple detection method for the elemental nano selenium. The elemental selenium can produce hydride in the system or can be converted to selenite with HCl/H{sub 2}O{sub 2} digestion.

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

    International Nuclear Information System (INIS)

    Tripadus, V.; Craciun, L.; Lacatusu, R.; Frontasyeva, M.V.; Stan, O.; Lyapunov, S.M.

    2000-01-01

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

  8. Benefits of raising crops and animals naturally enriched with selenium in areas with selenium deficiency

    International Nuclear Information System (INIS)

    Dzhudich, I.S.

    2008-01-01

    Selenium (Se) is implicated in the protection of body tissues against oxidative stress, maintenance of defences against infection, and modulation of growth and development. The natural environment has a profound influence on its contents in the food chain and the development and distribution of Se responsive diseases. To overcome the Se deficiency problem and assure safe and adequate Se intakes, different methods were developed. Its efficiency depends on Se compounds absorption, its nutritional availability, long-term retention, convertibility of tissue Se stores into biologically active forms and the history of Se nutrition, influencing the proportion of absorbed retained, or excreted Se from diet. Since the dominant metabolically active Se forms are found in proteins as seleno analogues of sulphur amino acids, rather than selenotrisulphides and other acid labile Se compounds, we developed our own procedure for foliar enrichment of crops with Se, enabling the production of crops and animals with adequate Se content in low Se areas. By foliar application of Se salts, we optimize Se contents of many parameters important for plants quality, thus contributing to the better status of many essential, in diet often deficient nutrients. The utilization of these crops in animal nutrition, contributes to the nutritive value of animal products not only due to adequate Se content, but also higher values of other quality parameters. Consumption of such produced crops and animal products by humans in areas with low dietary Se intake has shown to have significant overall health benefits

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

    Science.gov (United States)

    Yan, Lin; Johnson, LuAnn K

    2011-06-08

    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.

  10. Selenium Status in Heifers, Late Pregnancy Cows and Their Calves in the Šumava Region, Czech Republic

    Directory of Open Access Journals (Sweden)

    P. Slavík

    2007-01-01

    Full Text Available The objective of this study was to ascertain selenium status in beef cattle in different stages of production in the Šumava region. In the region, blood collections and analyses for selected metabolic variables were performed in 54 animals in different production stages (18 heifers, 18 cows in late pregnancy and 18 calves aged 3 weeks on the average. Three herds were studied. The selenium status was determined both directly by measuring serum selenium (Se contents and indirectly by measuring glutathione peroxidase (GSH-Px activity in whole blood. The mean serum selenium concentration in all the animals under study (n = 54 was 30.6 μg/l +/- 2.91, and mean GSH-Px activity was 167.01 μkat/l +/- 92.39. In heifers, mean serum selenium concentration was 34.81 μg/l +/- 13.84; mean GSHPx activity was 186.96 μkat/l +/- 112.15. In late pregnancy cows, mean serum selenium concentration was 26.58 μg/l +/- 8.01, mean GSH-Px activity was 94.55 +/- 35.72 μkat/l. In calves, mean serum selenium concentration and GSH-Px activity were 30.41 μg/l +/- 12 and 219.54 μkat/l +/- 64.41, respectively. There was a statistically significant difference between the heifers and late pregnancy cows in both variables under study. However, between the late pregnancy cows and the calves, only the difference in GSH-Px activity was significant. The results indicate severe Se deficiency in the animals under study. It means apart from other things that mineral licks used did not provide enough minerals to meet the basic requirements of the animals.

  11. Substoichiometric determination of selenium with potassium ethyl xanthate

    International Nuclear Information System (INIS)

    Chandrasekhar Reddy, P.; Polaiah, B.; Rangamannar, B.

    1989-01-01

    A substoichiometric radiochemical method was developed for the determination of selenium with potassium ethyl xanthate. The selenium ethyl xanthate complex formed was extracted into chloroform from borate buffer at pH 5. The effect of foreign ions on the extraction was studied. Microgram quantities of selenium could be conveniently determined with a fair degree of accuracy. The method was successfully applied for the determination of selenium content in food stuffs such as 'Jaggery' and 'Wheat powder'. (author) 4 refs.; 3 figs

  12. Effects of 14-day oral low dose selenium nanoparticles and selenite in rat—as determined by metabolite pattern determination

    Directory of Open Access Journals (Sweden)

    Niels Hadrup

    2016-10-01

    Full Text Available Selenium (Se is an essential element with a small difference between physiological and toxic doses. To provide more effective and safe Se dosing regimens, as compared to dosing with ionic selenium, nanoparticle formulations have been developed. However, due to the nano-formulation, unexpected toxic effects may occur. We used metabolite pattern determination in urine to investigate biological and/or toxic effects in rats administered nanoparticles and for comparison included ionic selenium at an equimolar dose in the form of sodium selenite. Low doses of 10 and 100 fold the recommended human high level were employed to study the effects at borderline toxicity. Evaluations of all significantly changed putative metabolites, showed that Se nanoparticles and sodium selenite induced similar dose dependent changes of the metabolite pattern. Putative identified metabolites included increased decenedioic acid and hydroxydecanedioic acid for both Se formulations whereas dipeptides were only increased for selenite. These effects could reflect altered fatty acid and protein metabolism, respectively.

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

    Directory of Open Access Journals (Sweden)

    Renata Germano B. O. N. Freitas

    2014-03-01

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

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

    NARCIS (Netherlands)

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

    2013-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    Graves' hyperthyroidism is an autoimmune disease causing hyperfunction of the thyroid gland. The concentration of selenium is high in the thyroid gland and two important groups of enzymes within the thyroid are selenoproteins, that is, they depend on selenium. Selenium may have beneficial effects...

  16. NAIL KERATIN AS MONITOR-TISSUE FOR SELENIUM EXPOSURE

    NARCIS (Netherlands)

    VANNOORD, PAH; MAAS, MJ; DEBRUIN, M

    1992-01-01

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

  17. Bio-induced solid selenium for recovery from water

    NARCIS (Netherlands)

    Hageman, S.P.W.

    2015-01-01

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

  18. Fontes orgânicas e inorgânicas de selênio na nutrição de vacas leiteiras: digestão, absorção, metabolismo e exigências Organic and inorganic sources of selenium in the nutrition of dairy cows: digestion, absorption, metabolism and requirements

    Directory of Open Access Journals (Sweden)

    Martin Gierus

    2007-08-01

    Full Text Available A suplementação de bovinos leiteiros com selênio é feita tanto em sua forma orgânica como inorgânica. Nas plantas, o Se é incorporado aleatoriamente na sua forma orgânica e encontra-se como análogo de aminoácidos sulfurados, ou seja, selenometionina e selenocisteína. As formas inorgânicas, por sua vez, correspondem aos sais selenato (SeO4-2 e selenito (SeO3-2. Contudo, enquanto a forma orgânica é metabolizada inicialmente como o aminoácido sulfurado análogo, as formas inorgânicas são metabolizadas diretamente via seleneto (HSe- para serem incorporadas em selenoproteínas funcionais, como a glutationa peroxidase. Assim, a selenometionina é metabolizada como a metionina, sendo incorporada ao acaso em proteínas do organismo. Somente após o turnover protéico, a selenometionina é então liberada, podendo servir como fonte de Se. Além disso, em animais de alta produção, a incorporação de selenometionina a proteínas do leite pode torná-la indisponível às selenoproteínas funcionais. Em função disso, análises da concentração de Se no solo, nos alimentos dos animais e no leite, são somente complementares à análise da atividade da glutationa peroxidase, pois não indicam o grau com que o Se vai ser metabolizado pelo animal. O Se no leite, por sua vez, reflete a concentração de fontes orgânicas de Se no sangue. Em torno de 70% do Se no leite está incorporado à caseína. A suplementação de Se para bovinos leiteiros é necessária em qualquer fase de crescimento ou estado fisiológico dos animais, mas o metabolismo das diferentes fontes de Se precisa ser considerado. Enquanto que, em deficiências agudas, fontes inorgânicas parecem ser mais apropriadas, as fontes orgânicas podem ser eficientes em casos de deficiência crônica ou em períodos de suplementação ineficiente de Se.Selenium is supplemented for dairy cattle using organic or inorganic selenium sources. In plants, Se is randomly incorporated also in

  19. Toenail mercury and dyslipidemia: Interaction with selenium.

    Science.gov (United States)

    Park, Kyong; Seo, Eunmin

    2017-01-01

    Although compelling evidences from in vivo and in vitro studies exist, limited studies have examined the association between chronic mercury exposure and dyslipidemia. Particularly, data are sparse regarding the influence of selenium on this association of mercury with dyslipidemia in humans. The purpose of the current study was to examine the associations of toenail mercury with dyslipidemia and its components, and to examine whether selenium in toenails modifies these associations. We performed cross-sectional analyses using baseline data from a cohort in the Yeungnam area in South Korea, including 232 men and 269 women. Toenail mercury and selenium concentrations were quantified using neutron activation analysis, and fasting serum lipid measurements were obtained through the medical examination. Odds ratios of the prevalent hypercholesterolemia, hyper-LDL-cholesterolemia, hypo-HDL-cholesterolemia, hypertriglyceridemia, and dyslipidemia in correlation with mercury levels were calculated using multivariable logistic regression. The mean levels of toenail mercury were 0.47μg/g for men and 0.34μg/g for women. After adjustment for multiple confounding variables, participants in the highest tertile of toenail mercury levels had 4.08 (95% CI 1.09-15.32, p for trend=0.02) times higher risk of hyper-LDL-cholesterolemia, and 2.24 (95% CI 1.15-4.37, p for trend=0.004) times higher risk of dyslipidemia than those in the lowest tertile. Selenium is a significant effect-modifier for these associations; the highest tertile of toenail mercury were significantly associated with a higher risk of hypercholesterolemia (OR 5.25, 95% CI 1.04-26.38) and dyslipidemia (OR 2.98, 95% CI 1.16-7.66) compared to the lowest tertile at toenail selenium levels ≤0.685μg/g, while these associations became weak and non-significant, showing OR 0.98 and 95% CI 0.25-3.80 for hypercholesterolemia and OR 1.99 and 95% CI 0.73-5.45 for dyslipidemia at toenail selenium levels >0.685μg/g. We

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

    Directory of Open Access Journals (Sweden)

    Holly L. Nicastro

    2013-04-01

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

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

    Science.gov (United States)

    Nicastro, Holly L.; Dunn, Barbara K.

    2013-01-01

    The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was conducted to assess the efficacy of selenium and vitamin E alone, and in combination, on the incidence of prostate cancer. This randomized, double-blind, placebo-controlled, 2 × 2 factorial design clinical trial found that neither selenium nor vitamin E reduced the incidence of prostate cancer after seven years and that vitamin E was associated with a 17% increased risk of prostate cancer compared to placebo. The null result was surprising given the strong preclinical and clinical evidence suggesting chemopreventive activity of selenium. Potential explanations for the null findings include the agent formulation and dose, the characteristics of the cohort, and the study design. It is likely that only specific subpopulations may benefit from selenium supplementation; therefore, future studies should consider the baseline selenium status of the participants, age of the cohort, and genotype of specific selenoproteins, among other characteristics, in order to determine the activity of selenium in cancer prevention. PMID:23552052

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

    International Nuclear Information System (INIS)

    Amoako, Prince O.; Uden, Peter C.; Tyson, Julian F.

    2009-01-01

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

  3. Impact of Selenium Addition to Animal Feeds on Human Selenium Status in Serbia

    Directory of Open Access Journals (Sweden)

    Zoran Pavlovic

    2018-02-01

    Full Text Available Research conducted during the 1980s demonstrated Se deficiency in humans. Increased inclusion of selenium in animal feeds started from the year 2000 onwards. The aim of this study was to estimate the effects of selenium inclusion in animal feeds on human selenium status and dietary habits of the Serbian population related to food of animal origin. Plasma selenium concentration in healthy adult volunteers, including residents of one of the regions with the lowest (Eastern Serbia, n = 60 and of one of the regions with the highest Se serum levels reported in the past (Belgrade, n = 82, was determined by hydride generation atomic absorption spectrometry. Multivariate analysis was employed to determine the correlation between Se plasma levels and dietary intake data derived from food frequency questionnaires and laboratory tests. The mean plasma Se level of the participants was 84.3 ± 15.9 μg/L (range: 47.3–132.1 μg/L, while 46% of participants had plasma Se levels lower than 80 μg/L. Frequency of meat, egg, and fish consumption was significantly correlated with plasma selenium level (r = 0.437, p = 0.000. Selenium addition to animal feed in the quantity of 0.14 mg/kg contributed to the improvement of human plasma selenium levels by approximately 30 μg/L.

  4. [Pharmaconutrition with parenteral selenium in sepsis].

    Science.gov (United States)

    Langlois, P L; de Oliveira Figliolino, L F; Hardy, G; Manzanares, W

    2014-04-01

    Critical illness is characterized by oxidative stress which leads to multiple organ failure, and sepsis-related organ dysfunction remains the most common cause of death in the intensive care unit. Over the last 2 decades, different antioxidant therapies have been developed to improve outcomes in septic patients. According to recent evidence, selenium therapy should be considered the cornerstone of the antioxidant strategies. Selenium given as selenious acid or sodium selenite should be considered as a drug or pharmaconutrient with prooxidant and cytotoxic effects when a loading dose in intravenous bolus form is administered, particularly in the early stage of severe sepsis/septic shock. To date, several phase ii trials have demonstrated that selenium therapy may be able to decrease mortality, improve organ dysfunction and reduce infections in critically ill septic patients. The effect of selenium therapy in sepsis syndrome must be confirmed by large, well designed phase iii clinical trials. The purpose of this review is to discuss current evidence on selenium pharmaconutrition in sepsis syndrome. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

  5. Loss of selenium-binding protein 1 decreases sensitivity to clastogens and intracellular selenium content in HeLa cells

    Science.gov (United States)

    Selenium-binding protein 1 (SBP1) is not a selenoprotein but structurally binds selenium. Loss of SBP1 during carcinogenesis usually predicts poor prognosis. Because genome instability is a hallmark of cancer, we hypothesized that loss of SBP1 modulates cellular selenium content and the response of ...

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

    NARCIS (Netherlands)

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

    2012-01-01

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

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

    OpenAIRE

    Azadeh SAFFARYAZDI; Mehrdad LAHOUTI; Ali GANJEALI; Hassan BAYAT

    2012-01-01

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

  8. Investigation of electrical noise in selenium-immersed thermistor bolometers

    Science.gov (United States)

    Tarpley, J. L.; Sarmiento, P. D.

    1980-01-01

    The selenium immersed, thermistor bolometer, IR detector failed due to spurious and escalating electrical noise outburst as a function of time at elevated temperatures during routine ground based testing in a space simulated environment. Spectrographic analysis of failed bolometers revealed selenium pure zones in the insulating selenium arsenic (Se-As) glass film which surrounds the active sintered Mn, Ni, Co oxide flake. The selenium pure film was identified as a potentially serious failure mechanism. Significant changes were instituted in the manufacturing techniques along with more stringent process controls which eliminated the selenium pure film and successfully produced 22study bolometers.

  9. Comparison between selenium and tellurium clusters

    International Nuclear Information System (INIS)

    Benamar, A.; Rayane, D.; Tribollet, B.; Broyer, M.; Melinon, P.

    1991-01-01

    Selenium and tellurium clusters are produced by the inert gas condensation technique. The mass spectra of both species are completely different and reveal different properties. In selenium, a periodicity of 6-7 is observed and may be interpreted by the binding energy between small cyclic molecules. Moreover, it was very difficult to obtained large clusters probably because the binding energy between these molecules is very small. In tellurium, these periodic structures do not exist and large clusters are easily obtained in nucleation conditions where only small selenium clusters are present. These results are discussed and a simple nucleation model is used to illustrate this different behavior. Finally these clusters properties are correlated to the bulk structure of both materials. (orig.)

  10. HORMONAL REGULATION OF SELENIUM ACCUMULATION BY PLANTS

    Directory of Open Access Journals (Sweden)

    N. A. Golubkina

    2015-01-01

    Full Text Available Hormonal regulation is considered to be a unique mechanism controlling growth and development of living organism. The review discusses the correlations between pant hormonal status of non-accumulators and hyper-accumulators of Se with the accumulation levels of this microelement. The phenomenon of stimulation and redistribution of selenium as a result of phytohormone treatment, the peculiarities of phytohormones effect among different species and cultivars, and influence of plant sexualization on selenium accumulation are described in article. Data of hormonal regulation of selenium level for spinach, garlic, perennial onion, Brassica chinenesis and Valeriana officialis are presented in the review.

  11. Quantitative selenium speciation in human urine by using liquid chromatography–electrospray tandem mass spectrometry

    International Nuclear Information System (INIS)

    Lu Ying; Rumpler, Alice; Francesconi, Kevin A.; Pergantis, Spiros A.

    2012-01-01

    Highlights: ► Development of a selected reaction monitoring mass spectrometric method for the identification of Se species in human urine. ► A selenosugar was detected as the major human urinary metabolite of selenium in the samples analysed. ► The trimethylselenonium ion was detected in the urine of one volunteer before and after receiving a selenium supplement. ► Strict quality control measures were applied to validate identification. ► Quantitation was conducted using an isotopically labelled internal standard and the standard additions methodology. - Abstract: A liquid chromatography–electrospray-tandem mass spectrometry (ES-MS/MS) method was developed for the speciation analysis of four organic selenium species of relevance to human urinary metabolism, namely trimethylselenomium ion (TMSe + ), selenomethionine (SeMet) and the two selenosugars, methyl 2-acetamido-2-deoxy-1-seleno-β-D-galactos/-glucos-amine (SeGalNAc and SeGluNAc, respectively). Their chromatographic separation was achieved by using a cation exchange pre-column coupled in-series with a reversed-phase high-performance liquid chromatography column, along with an isocratic mobile phase. Online detection was performed using ES-MS/MS in selective reaction monitoring mode. SeGalNAc was detected as the major human urinary metabolite of selenium in the samples analysed, whereas TMSe + was detected in the urine of one volunteer before and after receiving a selenium supplement. SeMet was not detected as a urine excretory metabolite in this study. Spiking experiments performed with the urine samples revealed significant signal suppression caused by coeluting matrix constituents. To overcome such interferences, isotopically labelled 13 CD 3 82 SeGalNAc was used as an internal standard, whereas in the absence of an isotopically labelled internal standard for TMSe + , the standard addition method was applied. Quality control for the accurate quantitation of TMSe + and SeGalNAc was carried out by

  12. Selenium and Breast Cancer Chemoprevention

    National Research Council Canada - National Science Library

    Thompson, Henry J

    2005-01-01

    .... The intermediate biomarkers being studied are as follows: indicators of oxidative damage to cellular macromolecules such as DNA and lipids, indicators of IGF metabolic status, and cellular indicators of breast cancer risk...

  13. Use of enriched 74Se and 77Se in combination with isotope pattern deconvolution to differentiate and determine endogenous and supplemented selenium in lactating rats

    International Nuclear Information System (INIS)

    Gonzalez Iglesias, H.; Fernandez Sanchez, M.L.; Garcia Alonso, J.I.; Sanz-Medel, A.

    2007-01-01

    A quantitative methodology has been developed to differentiate between endogenous and supplemented selenium in lactating rats using two enriched selenium isotopes. Lactating rats were fed for 2 weeks with formula milk containing one enriched Se isotope, 77 Se, as the metabolic tracer. The isotopic composition of selenium in serum and urine samples was then measured by collision cell ICP-MS after the addition of a solution containing another enriched isotope, 74 Se, as quantitation tracer, before analysis. Isotope pattern deconvolution allowed the transformation of measured Se isotopic abundances into concentrations of natural abundance (endogenous) selenium and enriched 77 Se (supplemented) present in the samples. The proposed methodology was validated using serum and urine reference materials spiked with both 77 Se and 74 Se. The obtained results are discussed in terms of selenium exchange and half-life in lactating rats (11-12 days) and selenium levels in serum in comparison with non-supplemented rats and control rats after maternal feeding. (orig.)

  14. Use of enriched {sup 74}Se and {sup 77}Se in combination with isotope pattern deconvolution to differentiate and determine endogenous and supplemented selenium in lactating rats

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Iglesias, H.; Fernandez Sanchez, M.L.; Garcia Alonso, J.I.; Sanz-Medel, A. [University of Oviedo, Department of Physical and Analytical Chemistry, Faculty of Chemistry, Oviedo (Spain)

    2007-10-15

    A quantitative methodology has been developed to differentiate between endogenous and supplemented selenium in lactating rats using two enriched selenium isotopes. Lactating rats were fed for 2 weeks with formula milk containing one enriched Se isotope, {sup 77}Se, as the metabolic tracer. The isotopic composition of selenium in serum and urine samples was then measured by collision cell ICP-MS after the addition of a solution containing another enriched isotope, {sup 74}Se, as quantitation tracer, before analysis. Isotope pattern deconvolution allowed the transformation of measured Se isotopic abundances into concentrations of natural abundance (endogenous) selenium and enriched {sup 77}Se (supplemented) present in the samples. The proposed methodology was validated using serum and urine reference materials spiked with both {sup 77}Se and {sup 74}Se. The obtained results are discussed in terms of selenium exchange and half-life in lactating rats (11-12 days) and selenium levels in serum in comparison with non-supplemented rats and control rats after maternal feeding. (orig.)

  15. Determination of selenium via the fluorescence quenching effect of selenium on hemoglobin-catalyzed peroxidative reaction.

    Science.gov (United States)

    Chen, Ya-Hong; Zhang, Ya-Nan; Tian, Feng-Shou

    2015-05-01

    A new method for the determination of selenium based on its fluorescence quenching on the hemoglobin-catalyzed reaction of H2 O2 and l-tyrosine has been established. The effect of pH, foreign ions and the optimization of variables on the determination of selenium was examined. The calibration curve was found to be linear between the fluorescence quenching (F0 /F) and the concentration of selenium within the range of 0.16-4.00 µg/mL. The detection limit was 1.96 ng/mL and the relative standard deviation was 3.14%. This method can be used for the determination of selenium in Se-enriched garlic bulbs with satisfactory results. Copyright © 2014 John Wiley & Sons, Ltd.

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

    Czech Academy of Sciences Publication Activity Database

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

    2007-01-01

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

  17. In vivo and in vitro testing for selenium and selenium compounds bioavailability assessment in foodstuff.

    Science.gov (United States)

    Moreda-Piñeiro, Jorge; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Pilar

    2017-03-04

    The assessment of selenium and selenium species bioavailability in foodstuff is of special concern on the context of human nutrition. In vivo (human and animal), and in vitro tests are important approaches for estimating the bioavailability of toxic and essential compounds to humans. An overview on in vivo and in vitro bioavailability assays for releasing selenium and selenium species in foodstuffs is summarized. Se and Se species content in a foodstuff critically influence Se bioavailability and bioactivity to humans and animals. Se bioavailability is affected by foodstuff-matrix major composition and minor components. Foodstuffs processing and/or treatments could enhancement or decrease Se bioavailability. Experimental conditions such as the selection of healthy status of examined people (in in vivo humans approaches), the selection of animal model (in vivo animals approaches), or the selection of GI conditions (in in vitro tests) could determines the results. Thus, international standardized protocol for in vivo and in vitro approaches assessment is mandatory.

  18. High-Resolution Imaging of Selenium in Kidneys: A Localized Selenium Pool Associated with Glutathione Peroxidase 3

    Science.gov (United States)

    Malinouski, Mikalai; Kehr, Sebastian; Finney, Lydia; Vogt, Stefan; Carlson, Bradley A.; Seravalli, Javier; Jin, Richard; Handy, Diane E.; Park, Thomas J.; Loscalzo, Joseph; Hatfield, Dolph L.

    2012-01-01

    Abstract Aim: Recent advances in quantitative methods and sensitive imaging techniques of trace elements provide opportunities to uncover and explain their biological roles. In particular, the distribution of selenium in tissues and cells under both physiological and pathological conditions remains unknown. In this work, we applied high-resolution synchrotron X-ray fluorescence microscopy (XFM) to map selenium distribution in mouse liver and kidney. Results: Liver showed a uniform selenium distribution that was dependent on selenocysteine tRNA[Ser]Sec and dietary selenium. In contrast, kidney selenium had both uniformly distributed and highly localized components, the latter visualized as thin circular structures surrounding proximal tubules. Other parts of the kidney, such as glomeruli and distal tubules, only manifested the uniformly distributed selenium pattern that co-localized with sulfur. We found that proximal tubule selenium localized to the basement membrane. It was preserved in Selenoprotein P knockout mice, but was completely eliminated in glutathione peroxidase 3 (GPx3) knockout mice, indicating that this selenium represented GPx3. We further imaged kidneys of another model organism, the naked mole rat, which showed a diminished uniformly distributed selenium pool, but preserved the circular proximal tubule signal. Innovation: We applied XFM to image selenium in mammalian tissues and identified a highly localized pool of this trace element at the basement membrane of kidneys that was associated with GPx3. Conclusion: XFM allowed us to define and explain the tissue topography of selenium in mammalian kidneys at submicron resolution. Antioxid. Redox Signal. 16, 185–192. PMID:21854231

  19. High-resolution imaging of selenium in kidneys: a localized selenium pool associated with glutathione peroxidase 3

    Energy Technology Data Exchange (ETDEWEB)

    Malinouski, M.; Kehr, S.; Finney, L.; Vogt, S.; Carlson, B.A.; Seravalli, J.; Jin, R.; Handy, D.E.; Park, T.J.; Loscalzo, J.; Hatfield, D.L.; Gladyshev, V.N. (Harvard-Med)

    2012-04-17

    Recent advances in quantitative methods and sensitive imaging techniques of trace elements provide opportunities to uncover and explain their biological roles. In particular, the distribution of selenium in tissues and cells under both physiological and pathological conditions remains unknown. In this work, we applied high-resolution synchrotron X-ray fluorescence microscopy (XFM) to map selenium distribution in mouse liver and kidney. Liver showed a uniform selenium distribution that was dependent on selenocysteine tRNA{sup [Ser]Sec} and dietary selenium. In contrast, kidney selenium had both uniformly distributed and highly localized components, the latter visualized as thin circular structures surrounding proximal tubules. Other parts of the kidney, such as glomeruli and distal tubules, only manifested the uniformly distributed selenium pattern that co-localized with sulfur. We found that proximal tubule selenium localized to the basement membrane. It was preserved in Selenoprotein P knockout mice, but was completely eliminated in glutathione peroxidase 3 (GPx3) knockout mice, indicating that this selenium represented GPx3. We further imaged kidneys of another model organism, the naked mole rat, which showed a diminished uniformly distributed selenium pool, but preserved the circular proximal tubule signal. We applied XFM to image selenium in mammalian tissues and identified a highly localized pool of this trace element at the basement membrane of kidneys that was associated with GPx3. XFM allowed us to define and explain the tissue topography of selenium in mammalian kidneys at submicron resolution.

  20. Status of selenium in cancer prevention

    Science.gov (United States)

    An abundance of data indicate that selenium (Se) can be antitumorigenic. Those data, mostly from controlled studies using animal tumor models and some from clinical studies in free-living people, indicate that treatment with Se in the absence of nutritional Se-deficiency, can reduce cancer risk. T...

  1. Chapter 6: Selenium Toxicity to Aquatic Organisms

    Science.gov (United States)

    This chapter addresses the characteristics and nature of organic selenium (Se) toxicity to aquatic organisms, based on the most current state of scientific knowledge. As such, the information contained in this chapter relates to the 'toxicity assessment' phase of aquatic ecologi...

  2. Normal mode calculations of trigonal selenium

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; McMurry, H. L.

    1980-01-01

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

  3. Overview and prospects of selenium phytoremediation approaches

    Science.gov (United States)

    Evidence is lacking on whether selenium (Se) is essential for vegetation growth, but plants can absorb, assimilate, and accumulate Se in leaves and roots. The capability of plants to take up substantial amount of Se is now being utilized to remove excess Se from contaminated soils. This process has ...

  4. Selenium speciation in anaerobic granular sludge

    NARCIS (Netherlands)

    Lenz, M.; Gmerek, A.; Lens, P.N.L.

    2006-01-01

    Chromatographic (IC-CD, GC-FID) and spectroscopic (XRD) techniques that allow the specific determination of several selenium species present or formed during bioremediation processes of selenate contaminated drinking, ground, or wastewaters have been established. The developed techniques are shown

  5. Radio protective effects of selenium on rats

    International Nuclear Information System (INIS)

    Bakir, A.; Alya, G

    2005-11-01

    Potential radio-protective effects of different selenium supplement concentrations of 4, 8, 15 and 30 ppm were evaluated in rats. Four groups of rats were administered different concentrations of selenium in drinking water for 30 days before irradiation starting from the ablactation which considered as day 0. The results showed that the sodium selenite of 4 ppm and 8 ppm enhance the 30-day survival of irradiated rats at 7 Gy ( sup 6 sup 0 Co source, whole body irradiation dose rate of 1 Gy x min sup - sup 1) compared to the control group. The mean cumulated probability of survival of rats was 69%+-6 (mean+-S.E.) and 77%+-6 in 4 and 8 ppm groups, respectively, versus 42%+-9 for control group (P<0.001). It was also indicated that sodium selenite with concentrations of 15 and 30 ppm had no significant reduction in mortality. The mean cumulated probability of survival of rats was 50%+-12 (P=0.39) and 49%+-14 (P=0.04), respectively. The toxic effects of selenium were observed at 15 ppm and 30 ppm, survivals after 30 days of selenium intake were 76% and 46%, respectively. It was concluded that 4 and 8 ppm sodium selenite have a radio-protective effect. 15 and 30 ppm sodium selenite had no radio-protective effects in rats, this may be due to a synergism of toxicity and radiation effects. (author)

  6. Reduced Utilization of Selenium by Naked Mole Rats Due to a Specific Defect in GPx1 Expression*

    Science.gov (United States)

    Kasaikina, Marina V.; Lobanov, Alexei V.; Malinouski, Mikalai Y.; Lee, Byung Cheon; Seravalli, Javier; Fomenko, Dmitri E.; Turanov, Anton A.; Finney, Lydia; Vogt, Stefan; Park, Thomas J.; Miller, Richard A.; Hatfield, Dolph L.; Gladyshev, Vadim N.

    2011-01-01

    Naked mole rat (MR) Heterocephalus glaber is a rodent model of delayed aging because of its unusually long life span (>28 years). It is also not known to develop cancer. In the current work, tissue imaging by x-ray fluorescence microscopy and direct analyses of trace elements revealed low levels of selenium in the MR liver and kidney, whereas MR and mouse brains had similar selenium levels. This effect was not explained by uniform selenium deficiency because methionine sulfoxide reductase activities were similar in mice and MR. However, glutathione peroxidase activity was an order of magnitude lower in MR liver and kidney than in mouse tissues. In addition, metabolic labeling of MR cells with 75Se revealed a loss of the abundant glutathione peroxidase 1 (GPx1) band, whereas other selenoproteins were preserved. To characterize the MR selenoproteome, we sequenced its liver transcriptome. Gene reconstruction revealed standard selenoprotein sequences except for GPx1, which had an early stop codon, and SelP, which had low selenocysteine content. When expressed in HEK 293 cells, MR GPx1 was present in low levels, and its expression could be rescued neither by removing the early stop codon nor by replacing its SECIS element. In addition, GPx1 mRNA was present in lower levels in MR liver than in mouse liver. To determine if GPx1 deficiency could account for the reduced selenium content, we analyzed GPx1 knock-out mice and found reduced selenium levels in their livers and kidneys. Thus, MR is characterized by the reduced utilization of selenium due to a specific defect in GPx1 expression. PMID:21372135

  7. Recovery of stream communities from experimental selenium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Swift, M.C.; Kuklinskal, B.; Ferkull, K. [Univ. of Minnesota, Monticello, MN (United States); Allen, K.N.; Hermanutz, R.O.; Roush, T.H.; Hedtke, S.F. [Environmental Protection Agency, Duluth, MN (United States). Environmental Research Lab.

    1994-12-31

    The effects of selenium on stream communities and their recovery from those effects were studied at MERS from 1987--1991. Selenium was dosed into two replicate streams each at concentrations of 30, 10, 2.5 and 0 (control) {mu}g L{sup {minus}1} for 18, 30, and 12 months, respectively. Recovery was monitored for three (30) or two (1 0, 2.5) years following cessation of selenium dosing. Selenium rapidly accumulated in the sediment, plants, macroinvertebrates and fish during dosing. Selenium concentrations in sediment, macroinvertebrates, and plants were as high as 2X--4X, 2X--4X, and 1X--1OX the dosed concentration in the 30, 10, and 2.5 treatments, respectively. Selenium decreased relatively rapidly following cessation of dosing. By two years after dosing ceased, selenium concentrations in plants and macroinvertebrates were little different from the controls; selenium in sediment from the 30 and 10 streams was still higher than in the control streams two years after dosing ceased. The macroinvertebrate community changed little during the dosing and recovery period. Commonly used indices of community structure showed no effect of selenium dosing. The isopod Asellus and oligochaetes in the family Tubificidae decreased rapidly following the onset of selenium dosing; their recovery following cessation of dosing was slow.

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

    International Nuclear Information System (INIS)

    Van Dyke, James U.; Hopkins, William A.; Jackson, Brian P.

    2013-01-01

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

  9. Low plasma selenium concentrations in critically ill children: the interaction effect between inflammation and selenium deficiency

    Science.gov (United States)

    2014-01-01

    Introduction Low plasma selenium concentrations are frequent in critically ill patients. However, whether this is due to systemic inflammation, a deficient nutritional state or both is still not clear. We aimed to determine the factors associated with low plasma selenium in critically ill children while considering the inflammatory response and nutritional status. Method A prospective study was conducted in 173 children (median age 34 months) with systemic inflammatory response who had plasma selenium concentrations assessed 48 hours after admission and on the 5th day of ICU stay. The normal reference range was 0.58 μmol/L to 1.6 μmol/L. The outcome variable was ‘low plasma selenium’, which was defined as plasma selenium values below the distribution median during this period. The main explanatory variables were age, malnutrition, sepsis, C-reactive protein (CRP), and clinical severity scores. The data were analyzed using a Binomial Generalized Estimating Equations model, which includes the correlation between admission and 5th day responses. Results Malnutrition and CRP were associated with low plasma selenium. The interaction effect between these two variables was significant. When CRP values were less than or equal to 40 mg/L, malnutrition was associated with low plasma selenium levels (odds ratio (OR) = 3.25, 95% confidence interval (CI) 1.39 to 7.63, P = 0.007; OR = 2.98, 95% CI 1.26 to 7.06, P = 0.013; OR = 2.49, 95% CI 1.01 to 6.17, P = 0.049, for CRP = 10, 20 and 40 mg/L, respectively). This effect decreased as CRP concentrations increased and there was loose significance when CRP values were >40 mg/L. Similarly, the effect of CRP on low plasma selenium was significant for well-nourished patients (OR = 1.13; 95% CI 1.06 to 1.22, P selenium. This interaction should be considered when interpreting plasma concentrations as an index of selenium status in patients with systemic inflammation as well as in the decision

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

    NARCIS (Netherlands)

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

    2004-01-01

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

  11. Bioavailibility of selenium from fish, yeast and selenate: a comparative study in humans using stable isotopes

    NARCIS (Netherlands)

    Fox, T.E.; Heuvel, van den E.G.H.M.; Atherton, C.A.; Luten, J.B.; Hoek-van Nieuwenhuizen, van M.; Kotterman, M.J.J.

    2004-01-01

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

  12. Antioxidant and hepatoprotective role of selenium against silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Ansar S

    2017-10-01

    Full Text Available Sabah Ansar,1 Saad M Alshehri,2 Manal Abudawood,1 Sherifa S Hamed,3,4 Tansir Ahamad2 1Clinical Laboratory Sciences, Applied Medical Science, King Saud University, Riyadh, Saudi Arabia; 2Department of Chemistry, College of Science, King Saud University, Riyadh, Saudi Arabia; 3Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia; 4Zoology Department, Faculty of Science, University of Alexandria, Moharram Bey, Alexandria, Egypt Abstract: Silver nanoparticles (AgNPs have attracted the most interest in terms of their potential biomedical and industrial applications. However, these nanoparticles have shown their toxic behavior toward environment, living tissues, and organisms. Selenium (Se, an essential trace element, is necessary for various metabolic processes, including protection against ­oxidative stress and immune function. The present study was undertaken to evaluate the effect of Se against AgNP-induced hepatic oxidative stress. AgNPs were synthesized and then prepared nanoparticles were characterized using various analytical techniques such as UV-visible spectroscopy, X-ray diffraction, and transmission electron microscopy. Rats were administered AgNPs intraperitoneally (5 mg/kg/day and Se (0.2 mg/kg was given by gavage. AgNP administration induced hepatic damage as indicated by the serum marker enzymes with reduction in levels of glutathione, and decrease in activities of SOD, CAT, and GSH-peroxidase (P<0.05. Decrease in levels of total antioxidant capacity (TAC and increase in level of C-reactive protein (CRP was also observed in AgNP-treated group compared to control group. However, Se markedly attenuated AgNP-induced biochemical alterations, levels of TAC, CRP, and serum transaminases (AST, ALT (P<0.05. Taken together, these findings suggest that administration of AgNPs produces hepatotoxicity in rats, whereas Se supplementation attenuates these effects. Keywords: silver nanoparticles, selenium, antioxidant

  13. Selenium utilization in thioredoxin and catalytic advantage provided by selenocysteine

    International Nuclear Information System (INIS)

    Kim, Moon-Jung; Lee, Byung Cheon; Hwang, Kwang Yeon; Gladyshev, Vadim N.; Kim, Hwa-Young

    2015-01-01

    Thioredoxin (Trx) is a major thiol-disulfide reductase that plays a role in many biological processes, including DNA replication and redox signaling. Although selenocysteine (Sec)-containing Trxs have been identified in certain bacteria, their enzymatic properties have not been characterized. In this study, we expressed a selenoprotein Trx from Treponema denticola, an oral spirochete, in Escherichia coli and characterized this selenoenzyme and its natural cysteine (Cys) homologue using E. coli Trx1 as a positive control. 75 Se metabolic labeling and mutation analyses showed that the SECIS (Sec insertion sequence) of T. denticola selenoprotein Trx is functional in the E. coli Sec insertion system with specific selenium incorporation into the Sec residue. The selenoprotein Trx exhibited approximately 10-fold higher catalytic activity than the Sec-to-Cys version and natural Cys homologue and E. coli Trx1, suggesting that Sec confers higher catalytic activity on this thiol-disulfide reductase. Kinetic analysis also showed that the selenoprotein Trx had a 30-fold higher K m than Cys-containing homologues, suggesting that this selenoenzyme is adapted to work efficiently with high concentrations of substrate. Collectively, the results of this study support the hypothesis that selenium utilization in oxidoreductase systems is primarily due to the catalytic advantage provided by the rare amino acid, Sec. - Highlights: • The first characterization of a selenoprotein Trx is presented. • The selenoenzyme Trx exhibits 10-fold higher catalytic activity than Cys homologues. • Se utilization in Trx is primarily due to the catalytic advantage provided by Sec residue

  14. Selenium utilization in thioredoxin and catalytic advantage provided by selenocysteine

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moon-Jung [Department of Biochemistry and Molecular Biology, Yeungnam University College of Medicine, Daegu 705-717 (Korea, Republic of); Lee, Byung Cheon [Division of Genetics, Department of Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA 02115 (United States); Division of Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of); Hwang, Kwang Yeon [Division of Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of); Gladyshev, Vadim N. [Division of Genetics, Department of Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA 02115 (United States); Kim, Hwa-Young, E-mail: hykim@ynu.ac.kr [Department of Biochemistry and Molecular Biology, Yeungnam University College of Medicine, Daegu 705-717 (Korea, Republic of)

    2015-06-12

    Thioredoxin (Trx) is a major thiol-disulfide reductase that plays a role in many biological processes, including DNA replication and redox signaling. Although selenocysteine (Sec)-containing Trxs have been identified in certain bacteria, their enzymatic properties have not been characterized. In this study, we expressed a selenoprotein Trx from Treponema denticola, an oral spirochete, in Escherichia coli and characterized this selenoenzyme and its natural cysteine (Cys) homologue using E. coli Trx1 as a positive control. {sup 75}Se metabolic labeling and mutation analyses showed that the SECIS (Sec insertion sequence) of T. denticola selenoprotein Trx is functional in the E. coli Sec insertion system with specific selenium incorporation into the Sec residue. The selenoprotein Trx exhibited approximately 10-fold higher catalytic activity than the Sec-to-Cys version and natural Cys homologue and E. coli Trx1, suggesting that Sec confers higher catalytic activity on this thiol-disulfide reductase. Kinetic analysis also showed that the selenoprotein Trx had a 30-fold higher K{sub m} than Cys-containing homologues, suggesting that this selenoenzyme is adapted to work efficiently with high concentrations of substrate. Collectively, the results of this study support the hypothesis that selenium utilization in oxidoreductase systems is primarily due to the catalytic advantage provided by the rare amino acid, Sec. - Highlights: • The first characterization of a selenoprotein Trx is presented. • The selenoenzyme Trx exhibits 10-fold higher catalytic activity than Cys homologues. • Se utilization in Trx is primarily due to the catalytic advantage provided by Sec residue.

  15. Engineering Cellular Metabolism

    DEFF Research Database (Denmark)

    Nielsen, Jens; Keasling, Jay

    2016-01-01

    Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds...... of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation....

  16. Enrichment of the African catfish Clarias gariepinus (Burchell) with functional selenium originating from garlic: effect of enrichment period and depuration on total selenium level and sensory properties

    NARCIS (Netherlands)

    Schram, E.; Schelvis-Smit, A.A.M.; Heul, van der J.W.; Luten, J.B.

    2010-01-01

    We wanted to optimize the procedure for the selenium enrichment of farmed African catfish, using garlic as dietary selenium source. In the first experiment we established the relation between the length of the selenium enrichment period and the resulting total selenium level in the fillet of the

  17. Internal disruption in tokamaks

    International Nuclear Information System (INIS)

    Kuvshinov, B.N.; Savrukhin, P.V.

    1990-01-01

    A review of results of experimental and theoretical investigations of internal disruption in tokamaks is given. Specific features of various types of saw-tooth oscillations are described and their classification is performed. Theoretical models of the process of development of internal disruption instability are discussed. Effect of internal disruption on parameters of plasma, confined in tokamak, is considered. Scalings of period and amplitude of saw-tooth oscillations, as well as version radius are presented. Different methods for stabilizing instability of internal disruption are described

  18. Internal disruptions in tokamaks

    International Nuclear Information System (INIS)

    Kuvshinov, B.N.; Savrukhin, P.V.

    1990-01-01

    Experimental and theoretical studies of the phenomenon of internal disruptions in tokamaks are reviewed. A classification scheme is introduced and the features of different types of sawtooth oscillations are described. A theoretical model for the development of the internal disruption instability is discussed. The effect of internal disruptions on the parameters of plasma confined in tokamaks is discussed. Scaling laws for the period and amplitude of sawtooth oscillations, as well as for the inversion radius, are presented. Different methods of stabilizing the internal disruption instability are described

  19. Randomised trial of glutamine and selenium supplemented parenteral nutrition for critically ill patients. Protocol Version 9, 19 February 2007 known as SIGNET (Scottish Intensive care Glutamine or seleNium Evaluative Trial

    Directory of Open Access Journals (Sweden)

    Vale Luke D

    2007-09-01

    Full Text Available Abstract Background Mortality rates in the Intensive Care Unit and subsequent hospital mortality rates in the UK remain high. Infections in Intensive Care are associated with a 2–3 times increased risk of death. It is thought that under conditions of severe metabolic stress glutamine becomes "conditionally essential". Selenium is an essential trace element that has antioxidant and anti-inflammatory properties. Approximately 23% of patients in Intensive Care require parenteral nutrition and glutamine and selenium are either absent or present in low amounts. Both glutamine and selenium have the potential to influence the immune system through independent biochemical pathways. Systematic reviews suggest that supplementing parenteral nutrition in critical illness with glutamine or selenium may reduce infections and mortality. Pilot data has shown that more than 50% of participants developed infections, typically resistant organisms. We are powered to show definitively whether supplementation of PN with either glutamine or selenium is effective at reducing new infections in critically ill patients. Methods/design 2 × 2 factorial, pragmatic, multicentre, double-blind, randomised controlled trial. The trial has an enrolment target of 500 patients. Inclusion criteria include: expected to be in critical care for at least 48 hours, aged 16 years or over, patients who require parenteral nutrition and are expected to have at least half their daily nutritional requirements given by that route. Allocation is to one of four iso-caloric, iso-nitrogenous groups: glutamine, selenium, both glutamine & selenium or no additional glutamine or selenium. Trial supplementation is given for up to seven days on the Intensive Care Unit and subsequent wards if practicable. The primary outcomes are episodes of infection in the 14 days after starting trial nutrition and mortality. Secondary outcomes include antibiotic usage, length of hospital stay, quality of life and

  20. Randomised trial of glutamine and selenium supplemented parenteral nutrition for critically ill patients. Protocol Version 9, 19 February 2007 known as SIGNET (Scottish Intensive care Glutamine or seleNium Evaluative Trial).

    Science.gov (United States)

    Andrews, Peter J D; Avenell, Alison; Noble, David W; Campbell, Marion K; Battison, Claire G; Croal, Bernard L; Simpson, William G; Norrie, John; Vale, Luke D; Cook, Jonathon; de Verteuil, Robyn; Milne, Anne C

    2007-09-20

    Mortality rates in the Intensive Care Unit and subsequent hospital mortality rates in the UK remain high. Infections in Intensive Care are associated with a 2-3 times increased risk of death. It is thought that under conditions of severe metabolic stress glutamine becomes "conditionally essential". Selenium is an essential trace element that has antioxidant and anti-inflammatory properties. Approximately 23% of patients in Intensive Care require parenteral nutrition and glutamine and selenium are either absent or present in low amounts. Both glutamine and selenium have the potential to influence the immune system through independent biochemical pathways. Systematic reviews suggest that supplementing parenteral nutrition in critical illness with glutamine or selenium may reduce infections and mortality. Pilot data has shown that more than 50% of participants developed infections, typically resistant organisms. We are powered to show definitively whether supplementation of PN with either glutamine or selenium is effective at reducing new infections in critically ill patients. 2 x 2 factorial, pragmatic, multicentre, double-blind, randomised controlled trial. The trial has an enrollment target of 500 patients. Inclusion criteria include: expected to be in critical care for at least 48 hours, aged 16 years or over, patients who require parenteral nutrition and are expected to have at least half their daily nutritional requirements given by that route. Allocation is to one of four iso-caloric, iso-nitrogenous groups: glutamine, selenium, both glutamine & selenium or no additional glutamine or selenium. Trial supplementation is given for up to seven days on the Intensive Care Unit and subsequent wards if practicable. The primary outcomes are episodes of infection in the 14 days after starting trial nutrition and mortality. Secondary outcomes include antibiotic usage, length of hospital stay, quality of life and cost-effectiveness. To date more than 285 patients have been

  1. Biogeochemical studies of selenium in the Indian Ocean

    International Nuclear Information System (INIS)

    Hattori, H.; Nakaguchi, Y.; Hiraki, K.; Kimura, M.; Koike, Y.

    1999-01-01

    Selenium that is a one of trace essential elements exists mainly in the chemical form of Se(IV), Se(VI) and organic selenium in ocean. Moreover, the monitoring of the selenium species has become a matter of interest as a mean of estimating their influence in biological processes in ocean. In recent works, some investigators reported that Se(IV) shows nutrient-type especially like silica's behavior, Se(VI) shows an approximately constant value, and the biological activities control the distribution of organic selenium. However, these reports were not included the whole world's oceans. It is necessary to research several oceans for the explication of fate on selenium. We investigated at the most interesting area - the Eastern Indian Ocean where should play a key role in global ocean's cycle for acquiring the new knowledge of selenium species at first

  2. Search for relevant indications for selenium supplementation in thyroid diseases.

    Science.gov (United States)

    Wojciechowska-Durczynska, Katarzyna; Lewinski, Andrzej

    2017-08-01

    Selenium plays a significant role in the thyroid function and its deficiency is considered by some authors to be a cause of thyroid disorders. The potential therapeutic influence of selenium supplementation in thyroid disease was investigated in several studies and some results were encouraging, however results were inconsistent and did not allow conclusion to be drawn. For that reason, we have performed a review study on relevance of selenium supplementation in thyroid disease. Till now, there is no strong evidence that selenium supplementation leads to clinical improvement in the course of autoimmune thyroiditis, nodular goitre or thyroid cancer. On the other hand, there is some evidence that selenium is effective in the treatment of orbitopathy; thus, the European Group on Graves' Orbitopathy (EUGOGO) recommends selenium administration in mild active orbitopathy.

  3. Effect of long-term selenium supplementation on mortality

    DEFF Research Database (Denmark)

    Rayman, Margaret P.; Winther, Kristian Hillert; Pastor-Barriuso, Roberto

    2018-01-01

    Background: Selenium, an essential trace element, is incorporated into selenoproteins with a wide range of health effects. Selenoproteins may reach repletion at a plasma selenium concentration of ∼ 125 μg/L, at which point the concentration of selenoprotein P reaches a plateau; whether sustained...... concentrations higher than this are beneficial, or indeed detrimental, is unknown. Objective: In a population of relatively low selenium status, we aimed to determine the effect on mortality of long-term selenium supplementation at different dose levels. Design: The Denmark PRECISE study was a single...... for extension of the study and mortality assessment. Participants were randomly assigned to treatment with 100, 200, or 300 μg selenium/d as selenium-enriched-yeast or placebo-yeast for 5 years from randomization in 1998-1999 and were followed up for mortality for a further 10 years (through March 31, 2015...

  4. Production of selenium-enriched milk and dairy products

    Directory of Open Access Journals (Sweden)

    Csapó J.

    2015-01-01

    Full Text Available Until the middle of the last century, selenium was considered to be toxic, but recently it turned out to be a micronutrient with important physiological effects, whose lack impedes the functioning of several enzymes, while in the case of a prolonged deficiency, disease processes can also occur in the body. Hungary belongs to the selenium-deficient regions in Europe; therefore, our aim was to contribute to the improvement of selenium supply of the population through increasing the selenium content of milk and dairy products. A daily supplementation of 1-6 mg organic selenium to the feed of dairy cows increases the selenium content of milk from the value of 18 μg/kg to 94 μg/kg in 8 weeks, decreasing again to the initial value in 6 weeks after stopping the supplementation.

  5. Erythrocytic glutathione peroxidase: Its relationship to plasma selenium in man

    International Nuclear Information System (INIS)

    Perona, G.; Cellerino, R.; Guidi, G.C.; Moschini, G.; Stievano, B.M.; Tregnaghi, C.

    1977-01-01

    Erythrocytic glutathione-peroxidase (GSH-Px) activity and plasma selenium concentrations were measured in 14 patients: 7 with iron deficiency and 7 with raised serum iron levels. The decreased enzymatic activity in iron deficiency was confirmed. Plasma selenium was significantly lower in patients with lower serum iron; furthermore there is a significant correlation between serum iron and plasma selenium concentrations. Another correlation even more significant was found between plasma selenium and enzyme activity in all the cases we studied. These data suggests that the importance of iron for GSH-Px activity may be merely due to its relationship with selenium and that plasma selenium concentration may be of critical importance for enzyme activity. (author)

  6. Selenium and arsenic in biology: their chemical forms and biological functions.

    Science.gov (United States)

    Shibata, Y; Morita, M; Fuwa, K

    1992-01-01

    Based on the recent development of analytical methods, sensitive systems for the analysis and speciation of selenium and arsenic have been established. A palladium addition technique was developed for the accurate determination of selenium in biological samples using graphite furnace atomic absorption analysis. For the speciation of the elements, combined methods of HPLC either with ICP-AES or with ICP-MS were found to work well. These systems were applied to the elucidation of the chemical form of the elements in natural samples. Some chemical properties of the selenium-mercury complex in dolphin liver were elucidated: i.e., it was a cationic, water-soluble, low molecular weight compound containing selenium and mercury in a 1:1 molar ratio, and was shown to be different from a known selenium-mercury complex, bis(methylmercuric)selenide. The major selenium compound excreted in human urine was revealed to be other than any of those previously identified (TMSe, selenate, and selenite). TMSe, a suspected major metabolite in urine, was found, if at all, in low levels. The major water-soluble, and lipid-soluble arsenic compounds in a brown seaweed, U. pinnatifida (WAKAME), were rigorously identified, and the results were compared with other data on marine algae and animals. The major organic arsenic compounds (termed "arseno-sugars") in marine algae commonly contain 5-deoxy-5-dimethylarsinyl-ribofuranoside moiety. There are various kinds of arseno-sugar derivatives containing different side-chains attached to the anomeric position of the sugar, and the distribution of each arsenic species seems to be related to algal species. The arseno-sugar (A-XI) is present in every alga so far examined, is metabolized to lipids, and possibly may play some specific role in the algal cells. On the other hand, the major arsenic compound in fish, crustacea and molluscs has been identified as arsenobetaine, which is an arseno-analog of glycinebetaine, a very common osmo-regulator in

  7. Selenium's importance in regulatory issues regarding mercury

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, Laura J.; Ralston, Nicholas V.C. [University of North Dakota Energy and Environmental Research Center, 15 North 23rd Street, Stop 9018, Grand Forks, ND 58202-9018 (United States)

    2009-11-15

    Current seafood safety and health risk assessment criteria use mercury concentrations as their sole basis. This unfortunate limitation omits consideration of selenium, an essential trace element that appears to be the primary molecular target of mercury toxicity. Although selenium has been recognized for decades as a means of counteracting mercury toxicity, its effects have often been overlooked or misunderstood. Experimental animal studies have demonstrated that increasing concentrations of selenium throughout the normal dietary range increasingly counteracts methylmercury toxicity. Dietary concentrations of selenium that are slightly less than the average amount present in ocean fish have been shown to completely prevent the onset of toxic symptoms of mercury toxicity, while animals fed lesser amounts of selenium rapidly sickened and died. Dietary selenium from a variety of sources including ocean fish such as tuna, swordfish, menhaden, and rockfish has been shown to counteract mercury toxicity. Since ocean fish are among the richest sources of dietary selenium, it is important to include selenium concentration measurements in future mercury risk assessments and seafood safety criteria. Mercury:selenium molar ratios in blood provide far more consistent and physiologically meaningful risk assessments. Comprehensive seafood safety criteria such as the Selenium Health Benefit Value enable clear differentiation between seafoods that are safe and those that are hazardous for human consumption. Use of parameters that integrate mercury-selenium relationships also make it easy to understand the differences between the findings of maternal mercury exposure studies that have been performed in New Zealand, the Faroes, the Seychelles, and the United Kingdom. Development of criteria for evaluating mercury-selenium interactions will enhance environmental protection and improve public safety. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.E.

    2000-02-01

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

  9. Effect of selenium supplementation on pigeon reproductive performance, selenium concentration and antioxidant status.

    Science.gov (United States)

    Wang, Y; Yang, H M; Cao, W; Li, Y B

    2017-09-01

    The effects of dietary supplementation of sodium selenite (SS) on the reproductive performance and the concentration of selenium, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and malondialdehyde (MDA) were determined, and expression of glutathione peroxidase 4 (GPx4) and bone morphogenic protein 15 (BMP15) was evaluated. Paired pigeons (n = 864) were fed: T1 received no SS, while T2, T3, and T4 received 0.5, 1.0, and 1.5 mg of SS/kg of dry matter (DM), respectively. Treatments were performed in triplicate with 72 pairs in each replicate. The results showed that selenium supplementation significantly affected pigeon reproductive performance. Birds fed 1.0 mg of SS/kg displayed higher egg production (P > 0.05), higher birth rate, and lower dead sperm rate than the control group (P Selenium and biochemical analyses revealed a higher selenium concentration in the 1.5 mg of SS/kg group than in the control group (P  0.05); however, in plasma, MDA was lower in the control group (P  0.05), while in ovary, BMP15 was down-regulated in the 1.5 mg of SS/kg group (P selenium concentration, and 0.5 mg of SS/kg up-regulated GSH-Px activity. © 2017 Poultry Science Association Inc.

  10. Disruptions in JET

    International Nuclear Information System (INIS)

    Wesson, J.A.; Gill, R.D.; Hugon, M.

    1989-01-01

    In JET, both high density and low-q operation are limited by disruptions. The density limit disruptions are caused initially by impurity radiation. This causes a contraction of the plasma temperature profile and leads to an MHD unstable configuration. There is evidence of magnetic island formation resulting in minor disruptions. After several minor disruptions, a major disruption with a rapid energy quench occurs. This event takes place in two stages. In the first stage there is a loss of energy from the central region. In the second stage there is a more rapid drop to a very low temperature, apparently due to a dramatic increase in impurity radiation. The final current decay takes place in the resulting cold plasma. During the growth of the MHD instability the initially rotating mode is brought to rest. This mode locking is believed to be due to an electromagnetic interaction with the vacuum vessel and external magnetic field asymmetries. The low-q disruptions are remarkable for the precision with which they occur at q ψ = 2. These disruptions do not have extended precursors or minor disruptions. The instability grows and locks rapidly. The energy quench and current decay are generally similar to those of the density limit. (author). 43 refs, 35 figs, 3 tabs

  11. Ecological Importance of Insects in Selenium Biogenic Cycling

    Directory of Open Access Journals (Sweden)

    Nadezhda Golubkina

    2014-01-01

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

  12. Is selenium supplementation in autoimmune thyroid diseases justified?

    Science.gov (United States)

    Winther, Kristian H; Bonnema, Steen J; Hegedüs, Laszlo

    2017-10-01

    This review provides an appraisal of recent evidence for or against selenium supplementation in patients with autoimmune thyroid diseases, and discusses possible effect mechanisms. Epidemiological data suggest an increased prevalence of autoimmune thyroid diseases under conditions of low dietary selenium intake. Two systematic reviews have evaluated controlled trials among patients with autoimmune thyroiditis and report that selenium supplementation decreases circulating thyroid autoantibodies. The immunomodulatory effects of selenium might involve reducing proinflammatory cytokine release. However, clinically relevant effects of selenium supplementation, including improvement in quality of life, are more elusive. In Graves' disease, some, but not all, trials indicate that adjuvant selenium supplementation enhances the restoration of biochemical euthyroidism, and might benefit patients with mild Graves' orbitopathy. The use of selenium supplementation as adjuvant therapy to standard thyroid medication may be widespread, but a growing body of evidence yields equivocal results. The available evidence from trials does not support routine selenium supplementation in the standard treatment of patients with autoimmune thyroiditis or Graves' disease. However, correction of moderate to severe selenium deficiency may offer benefits in preventing, as well as treating, these disorders. Molecular mechanisms have been proposed, but further studies are needed.

  13. Absorption and retention of selenium from shrimps in man

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  14. Selenium and phosphorus interaction in pea (pisum sativum L.)

    International Nuclear Information System (INIS)

    Singh, Mahendra; Bhandari, D.K.

    1975-01-01

    The interaction of selenium and phosphorus on the dry matter yield and concentration and uptake of phosphorus, sulfur and selenium was studied in pea (Pisum sativnum) var. T 163. The fertilizer was tagged with P 32 . It was observed that increased concentration of applied selenium in soil decreased the dry matter yield and increased the concentration and uptake of total P, soil P and selenium in pea plants. Increased concentration of P alone increased dry matter yield, concentration and uptake of total, soil and fertilizer P and selenium which was beyond safe limits, and decreased concentration and uptake of sulphur. Selenium and phosphorus showed strong synergetic relationship by increasing the concentration of each other in plants while both showed antagonistic effect on the concentration of sulphur. Phosphorus compensated the toxic effect of selenium and improved the growth and dry matter yield of pea plants. The highest selenium concentration of 22.4 ppm was observed in 100 ppm phosphorus with 5 ppm selenium treated pots while lowest (0.10 ppm) in control. (author)

  15. Does mercury vapor exposure increase urinary selenium excretion

    Energy Technology Data Exchange (ETDEWEB)

    Hongo, T; Suzuki, T; Himeno, S; Watanabe, C; Satoh, H; Shimada, Y

    1985-01-01

    It has been reported that an increase of urinary selenium excretion may occur as a result of mercury vapor exposure. However, experimental data regarding the interaction between mercury vapor and selenium have yielded ambiguous results about the retention and elimination of selenium due to mercury vapor exposure and the decrease of selenium excretion due to mercury in the form of mercuric mercury (Hg/sup 2 +/). In this study, the authors measured urinary mercury and selenium in workers with or without exposure to mercury vapor to determine whether or not urinary selenium excretion was increased as a result of mercury vapor exposure. Urine samples were collected from 141 workers, 71 men and 70 women, whose extent of exposure to mercury vapor varied according to their job sites. Workers were divided into five groups according to their urinary mercury levels. The mercury level in group I was less than 2.8 nmol/mmol creatinine which means that this group was mostly free from mercury exposure. The average age was almost identical among the groups. For both sexes, group V (with the highest urinary mercury level) had the lowest urinary selenium level, but one-way variance analysis (ANOVA) did not reveal any significant variations of urinary selenium with urinary mercury levels; however, a weak but significant negative correlation between mercury and selenium was found in men.

  16. Mechanistic evaluation of endocrine disrupting chemicals

    DEFF Research Database (Denmark)

    Taxvig, Camilla

    BACKGROUND: This PhD project is part of the research area concerning effects of endocrine disrupters at the National Food Institute at DTU in Denmark. Endocrine disrupting chemicals (EDCs) have proved to be important for improper development of the male reproductive organs and subsequent for the ...... metabolising system using liver S9 mixtures or hepatic rat microsomes could be a convenient method for the incorporation of metabolic aspects into in vitro testing for endocrine disrupting effects.......BACKGROUND: This PhD project is part of the research area concerning effects of endocrine disrupters at the National Food Institute at DTU in Denmark. Endocrine disrupting chemicals (EDCs) have proved to be important for improper development of the male reproductive organs and subsequent......, to be able to detect effects and predict mixture effects. In addition, a new hypothesis have emerge concerning a potential role of exposure to endocrine disrupting chemicals, and the development of obesity and obesity related diseases. AIM: This PhD project aimed to gain more information regarding...

  17. Disruptions in Tokamaks

    International Nuclear Information System (INIS)

    Bondeson, A.

    1987-01-01

    This paper discusses major and minor disruptions in Tokamaks. A number of models and numerical simulations of disruptions based on resistive MHD are reviewed. A discussion is given of how disruptive current profiles are correlated with the experimentally known operational limits in density and current. It is argued that the q a =2 limit is connected with stabilization of the m=2/n=1 tearing mode for a approx.< 2.7 by resistive walls and mode rotation. Experimental and theoretical observations indicate that major disruptions usually occur in at least two phases, first a 'predisruption', or loss of confinement in the region 1 < q < 2, leaving the q approx.= 1 region almost unaffected, followed by a final disruption of the central part, interpreted here as a toroidal n = 1 external kink mode. (author)

  18. Effect of protein, carbohydrate, lipid, and selenium levels on the performance, carcass yield, and blood changes in broilers

    Directory of Open Access Journals (Sweden)

    FH Hada

    2013-12-01

    Full Text Available The objective of this study was to evaluate the performance, carcass and parts yield, and blood changes in broilers fed different protein, carbohydrate, and lipid levels. Birds were fed a commercial diet until seven days of age. On day 8, birds were distributed according to a completely randomized experimental design in a 4 x 2 factorial arrangement (control diet, low protein diet, low carbohydrate diet or low lipid diet vs. supplementation of 0 or 0.3ppm organic selenium with four replicates of 15 birds each. Broilers fed low protein presented lower body weight, feed intake, and worse feed conversion ratio on day 42, as well as lower carcass and breast yields, higher leg and abdominal fat yields, higher triglyceride and lower uric acid blood levels. Broilers fed the low carbohydrate diets presented low glucose levels on days 14 and 42.Creatine-kinase (CK levels increased as birds aged. The livability of broilers fed the low protein diets improved and of those fed low carbohydrate diets worsened with dietary selenium addition on days 35 and 42. Selenium supplementation increased glucose levels in 42-d-old broilers. Changes in dietary protein caused more impact on broiler performance compared with carbohydrates and lipids. Changes in macronutrients caused metabolic changes in broilers. Selenium affected broiler livability as measured on days 35 and 42, and glucose blood levels.

  19. High-Resolution Imaging of Selenium in Kidneys: A Localized Selenium Pool Associated with Glutathione Peroxidase 3

    OpenAIRE

    Malinouski, Mikalai; Kehr, Sebastian; Finney, Lydia; Vogt, Stefan; Carlson, Bradley A.; Seravalli, Javier; Jin, Richard; Handy, Diane E.; Park, Thomas J.; Loscalzo, Joseph; Hatfield, Dolph L.; Gladyshev, Vadim N.

    2012-01-01

    Aim: Recent advances in quantitative methods and sensitive imaging techniques of trace elements provide opportunities to uncover and explain their biological roles. In particular, the distribution of selenium in tissues and cells under both physiological and pathological conditions remains unknown. In this work, we applied high-resolution synchrotron X-ray fluorescence microscopy (XFM) to map selenium distribution in mouse liver and kidney. Results: Liver showed a uniform selenium distributio...

  20. Preparation of selenium coatings onto beryllium foils

    International Nuclear Information System (INIS)

    Erikson, E.D.; Tassano, P.L.; Reiss, R.H.; Griggs, G.E.

    1984-09-01

    A technique for preparing selenium films onto 50.8 microns thick beryllium foils is described. The selenium was deposited in vacuum from a resistance heated evaporation source. Profilometry measurements of the coatings indicate deposit thicknesses of 5.5, 12.9, 37.5, 49.8 and 74.5 microns. The control of deposition rate and of coating thickness was facilitated using a commercially available closed-loop programmable thin film controller. The x-ray transmission of the coated substrates was measured using a tritiated zirconium source. The transmissivities of the film/substrate combination are presented for the range of energies from 4 to 20 keV. 15 references, 3 figures

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

    Science.gov (United States)

    Zeng, Huawei; Cao, Jay J; Combs, Gerald F

    2013-01-10

    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 of the mechanisms by which Se supports these cellular processes can lead to a better understanding of the role of this nutrient in normal bone metabolism. This article reviews the current knowledge concerning the molecular functions of Se relevant to bone health.

  2. The Cultivation and SeleniumEnrichment of SeleniumEnriched Earthworm

    Directory of Open Access Journals (Sweden)

    SUN Xiao-fei

    2014-12-01

    Full Text Available As a bio-carrier, Eisenia fetida was fed with cow dung that added with sodium selenite in order to transfer inorganic selenium(Se into organic selenium. Targeting on survival rate and selenium content, the effects of five Se concentrations(0, 20, 40, 60, 80, 100 mg·kg-1 and four cultivation periods(15, 30, 45, 60 don earthworm growth and Se contents were investigated. The cultivation method with high survival rate, high Se content of earthworm and short breeding time would be screened out. The experimental results showed that the earthworm survival rate decreased and the Se content in earthworm increased with the increase of Se application and the extension of breeding time. The most optimummethod was screened out when the Se concentration was 80 mg·kg-1 and the cultivation period was 45 days, Se content in earthworm was up to 33.25 mg·kg-1.

  3. Polarographic determination of selenium in indium

    International Nuclear Information System (INIS)

    Kaplan, B.Ya.; Mikheeva, V.A.; Priz, N.B.

    1978-01-01

    The procedure of determining nx10 -6 % Se in indium after concentrating in an elemental form on arsenic and sulphur has been developed. The selenium content is determined by inversion a.c. polarography on a sulphuric-acid background in the presence of Cu(2), potassium bichromate, and sodium pyrophosphate. 5.7x10 -6 % Se in metal indium has been determined by this procedure, the mean standard deviation being Sr=0.26

  4. Improvement of Selenium Status of Pasture Crops

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel

    1984-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Azadeh SAFFARYAZDI

    2012-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Azadeh SAFFARYAZDI

    2012-11-01

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

  7. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Mills, T. R.; McInteer, B. B.; Montoya, J. G.

    1988-01-01

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of these isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separation of 32 S vs. 34 S were 1.127 for H 2 S, 1.048 for COS, 0.838 for SF 4 , and 1.058 for CH 3 SH. Relative volatilities of 32 S vs. 34 S are 1.0006 for COS and 0.9976 for SF 4 . There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H 2 Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produced separated isotopes with an effect similar to that found for sulfur in SF 4 . 8 refs., 2 tabs

  8. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Mills, T.R.; McInteer, B.B.; Montoya, J.G.

    1989-01-01

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of theses isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separations of 32 S vs. 34 S were 1.127 for H 2 S, 1.048 for COS, 0.838 for SF 4 , and 1.058 for CH 3 SH. Relative volatilities of 32 S and 34 S are 1.0006 for COS and 0.9976 for SF 4 . There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H 2 Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produces separated isotopes with an effect similar to that found for sulfur in SF 4 . (author). 8 refs.; 2 tabs

  9. Bacteria versus selenium: A view from the inside out

    Science.gov (United States)

    Staicu, Lucian; Oremland, Ronald S.; Tobe, Ryuta; Mihara, Hisaaki

    2017-01-01

    Bacteria and selenium (Se) are closely interlinked as the element serves both essential nutrient requirements and energy generation functions. However, Se can also behave as a powerful toxicant for bacterial homeostasis. Conversely, bacteria play a tremendous role in the cycling of Se between different environmental compartments, and bacterial metabolism has been shown to participate to all valence state transformations undergone by Se in nature. Bacteria possess an extensive molecular repertoire for Se metabolism. At the end of the 1980s, a novel mode of anaerobic respiration based on Se oxyanions was experimentally documented for the first time. Following this discovery, specific enzymes capable of reducing Se oxyanions and harvesting energy were found in a number of anaerobic bacteria. The genes involved in the expression of these enzymes have later been identified and cloned. This iterative approach undertaken outside-in led to the understanding of the molecular mechanisms of Se transformations in bacteria. Based on the extensive knowledge accumulated over the years, we now have a full(er) view from the inside out, from DNA-encoding genes to enzymes and thermodynamics. Bacterial transformations of Se for assimilatory purposes have been the object of numerous studies predating the investigation of Se respiration. Remarkable contributions related to the understating of the molecular picture underlying seleno-amino acid biosynthesis are reviewed herein. Under certain circumstances, Se is a toxicant for bacterial metabolism and bacteria have evolved strategies to counteract this toxicity, most notably by the formation of elemental Se (nano)particles. Several biotechnological applications, such as the production of functional materials and the biofortification of crop species using Se-utilizing bacteria, are presented in this chapter.

  10. Understanding disruptions in tokamaksa)

    Science.gov (United States)

    Zakharov, Leonid E.; Galkin, Sergei A.; Gerasimov, Sergei N.; contributors, JET-EFDA

    2012-05-01

    This paper describes progress achieved since 2007 in understanding disruptions in tokamaks, when the effect of plasma current sharing with the wall was introduced into theory. As a result, the toroidal asymmetry of the plasma current measurements during vertical disruption event (VDE) on the Joint European Torus was explained. A new kind of plasma equilibria and mode coupling was introduced into theory, which can explain the duration of the external kink 1/1 mode during VDE. The paper presents first results of numerical simulations using a free boundary plasma model, relevant to disruptions.

  11. 21 CFR 522.2100 - Selenium, vitamin E injection.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Selenium, vitamin E injection. 522.2100 Section... § 522.2100 Selenium, vitamin E injection. (a)(1) Specifications. The drug is an emulsion containing in... of vitamin E (68 I.U.) (as d-alpha tocopheryl acetate). (2) Sponsor. See No. 000061 in § 510.600(c...

  12. Low blood selenium: A probable factor in essential hypertension ...

    African Journals Online (AJOL)

    Blood selenium (BSe) and plasma glutathione peroxidase (plGSH-Px) activity were measured as biochemical markers of selenium status of 103 hypertensive patients (44 males and 59 females) and 88 apparently healthy subjects (40 males and 48 females). The hypertensive patients were classified into three groups based ...

  13. Enrichment of African catfish with functional selenium originating from garlic

    NARCIS (Netherlands)

    Schram, E.; Pedrero, Z.; Camara, C.; Heul, van der J.W.; Luten, J.B.

    2008-01-01

    We wanted to create functional seafood with high concentrations of organic selenium (seleno-methyl-selenocysteine and ¿-glutamyl-seleno-methyl-selenocysteine) with anti-carcinogenic properties for human consumers. Garlic containing high concentrations of these organic selenium compounds was used as

  14. Relationship between soil contents and plasma levels of selenium ...

    African Journals Online (AJOL)

    The soil contents of trace elements selenium, chromium and manganese were measured to determine their impact on the plasma levels of 160 healthy adult Nigerians in five different experimental locations in Cross River and Akwa Ibom States, South - South Nigeria. The mean (±SD) soil selenium, chromium and ...

  15. Aquatic selenium pollution is a global environmental safety issue

    Science.gov (United States)

    A. Dennis Lemly

    2004-01-01

    Selenium pollution is a worldwide phenomenon and is associated with a broad spectrum of human activities, ranging from the most basic agricultural practices to the most high-tech industrial processes. Consequently, selenium contamination of aquatic habitats can take place in urban, suburban, and rural settings alike--from mountains to plains, from deserts to...

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  17. Preliminary study of daily selenium level intake in algeria

    International Nuclear Information System (INIS)

    Benamar, M.A.; Tchantchane, A.; Tobbeche, S.

    1992-10-01

    The amount of selenium in onions and potatoes was measured by Pixe (particle Induced X-ray Emission) in the Nuclear Center at Bordeaux-Gradignan (CNBG). The goal of this work is to investigate the level of selenium concentration that may be consumed by different class of people

  18. Disruptive Mood Dysregulation Disorder

    Science.gov (United States)

    ... Application Process Managing Grants Clinical Research Training Small Business Research Labs at NIMH Labs at NIMH Home Research ... Chat on Disruptive Mood Dysregulation Disorder (Archived Transcript) Research and ... Journal Articles: References and abstracts from MEDLINE/PubMed (National ...

  19. Disruption Rose Tinted II

    OpenAIRE

    Livingstone, Andrew

    2009-01-01

    'Disruption - Rose Tinted II' continues to engage narratives of historical English china as previously explored in the work 'Rose Tinted'. This work engages the sleepy rural idyll which is overlaid with visual contemporary social commentary.

  20. Digital disruption ?syndromes.

    Science.gov (United States)

    Sullivan, Clair; Staib, Andrew

    2017-05-18

    The digital transformation of hospitals in Australia is occurring rapidly in order to facilitate innovation and improve efficiency. Rapid transformation can cause temporary disruption of hospital workflows and staff as processes are adapted to the new digital workflows. The aim of this paper is to outline various types of digital disruption and some strategies for effective management. A large tertiary university hospital recently underwent a rapid, successful roll-out of an integrated electronic medical record (EMR). We observed this transformation and propose several digital disruption "syndromes" to assist with understanding and management during digital transformation: digital deceleration, digital transparency, digital hypervigilance, data discordance, digital churn and post-digital 'depression'. These 'syndromes' are defined and discussed in detail. Successful management of this temporary digital disruption is important to ensure a successful transition to a digital platform. What is known about this topic? Digital disruption is defined as the changes facilitated by digital technologies that occur at a pace and magnitude that disrupt established ways of value creation, social interactions, doing business and more generally our thinking. Increasing numbers of Australian hospitals are implementing digital solutions to replace traditional paper-based systems for patient care in order to create opportunities for improved care and efficiencies. Such large scale change has the potential to create transient disruption to workflows and staff. Managing this temporary disruption effectively is an important factor in the successful implementation of an EMR. What does this paper add? A large tertiary university hospital recently underwent a successful rapid roll-out of an integrated electronic medical record (EMR) to become Australia's largest digital hospital over a 3-week period. We observed and assisted with the management of several cultural, behavioural and

  1. Search and Disrupt

    DEFF Research Database (Denmark)

    Ørding Olsen, Anders

    . However, incumbent sources engaged in capability reconfiguration to accommodate disruption improve search efforts in disruptive technologies. The paper concludes that the value of external sources is contingent on more than their knowledge. Specifically, interdependence of sources in search gives rise...... to influence from individual strategic interests on the outcomes. More generally, this points to the need for understanding the two-way influence of sources, rather than viewing external search as one-way knowledge accessing....

  2. Response of selenium changes in blood using cyclic activation analysis

    International Nuclear Information System (INIS)

    Spyrou, N.M.; Akanle, O.B.; Damyanova, A.A.

    1986-01-01

    A study was undertaken to investigate the response of selenium uptake and washout in whole blood and its components in healthy subjects, aged 20 to 30 yr, who were given selenium as a supplement to their usual diet, in the form of a yeast tablet (200 mg) containing 100 μg of the element together with vitamins A, C, and E (natural). Selenium has gained worldwide interest not only as an essential trace element but as a potent modifier of environmental hazards and as a naturally occurring toxicant. It is important therefore to investigate the character and the degree of the changes in healthy people on selenium supplementation. Cyclic activation analysis was used for the determination of selenium concentration through the detection of /sup 77m/Se (17.5 s), because of the increased sensitivity of the method and the large number of samples involved

  3. Genome-wide association study of serum selenium concentrations

    DEFF Research Database (Denmark)

    Gong, Jian; Hsu, Li; Harrison, Tabitha

    2013-01-01

    Selenium is an essential trace element and circulating selenium concentrations have been associated with a wide range of diseases. Candidate gene studies suggest that circulating selenium concentrations may be impacted by genetic variation; however, no study has comprehensively investigated...... this hypothesis. Therefore, we conducted a two-stage genome-wide association study to identify genetic variants associated with serum selenium concentrations in 1203 European descents from two cohorts: the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening and the Women’s Health Initiative (WHI). We...... tested association between 2,474,333 single nucleotide polymorphisms (SNPs) and serum selenium concentrations using linear regression models. In the first stage (PLCO) 41 SNPs clustered in 15 regions had p

  4. Reproduction in eastern screech-owls fed selenium

    Science.gov (United States)

    Wiemeyer, Stanley N.; Hoffman, D.J.

    1996-01-01

    Raptors are occasionally exposed to excessive selenium from contaminated prey, but the effects of this exposure on reproduction are unknown. Therefore, we fed captive eastern screech-owls (Otus asio) diets containing 0, 4.4, or 13.2 ppm (wet wt) added selenium in the form of seleno-DL-methionine. Adult mass at sacrifice and reproductive success of birds receiving 13.2 ppm selenium were depressed (P biochemistries indicative of oxidative stress were affected (P < 0.05) in 5-day-old nestlings from parents fed 4.4 ppm selenium and included a 19% increase in glutathione peroxidase activity, a 43% increase in the ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH), and a 17% increase in lipid peroxidation. Based on reproductive effects relative to dietary exposure, sensitivity of eastern screech-owls to selenium was similar to that of black-crowned night-herons (Nycticorax nycticorax) but less than that of mallards (Anas platyrhynchos).

  5. Recent Microextraction Techniques for Determination and Chemical Speciation of Selenium

    Directory of Open Access Journals (Sweden)

    Ibrahim Ahmed S. A.

    2017-05-01

    Full Text Available Research designed to improve extraction has led to the development of microextraction techniques (ME, which involve simple, low cost, and effective preconcentrationof analytes in various matrices. This review is concerned with the principles and theoretical background of ME, as well as the development of applications for selenium analysis during the period from 2008 to 2016. Among all ME, dispersive liquid-liquid microextraction was found to be most favorable for selenium. On the other hand, atomic absorption spectrometry was the most frequently used instrumentation. Selenium ME have rarely been coupled to spectrophotometry and X-ray spectrophotometry methods, and there is no published application of ME with electrochemical techniques. We strongly support the idea of using a double preconcentration process, which consists of microextraction prior to preconcentration, followed by selenium determination using cathodic stripping voltammetry (ME-CSV. More attention should focus on the development of accurate, precise, and green methods for selenium analysis.

  6. Selenium fertilization on lentil (Lens culinaris Medikus) grain yield, seed selenium concentration, and antioxidant activity

    Science.gov (United States)

    Selenium (Se) is an essential element for mammals but has not been considered as an essential element for higher plants. Lentil (Lens culinaris Medik.) is a cool season food legume rich in protein and a range of micronutrients including minerals (iron and zinc), folates, and carotenoids. The objecti...

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

    International Nuclear Information System (INIS)

    Beladel, B.; Nedjimi, B.; Mansouri, A.; Tahtat, D.; Belamri, M.; Tchanchane, A.; Khelfaoui, F.; Benamar, M.E.A.

    2013-01-01

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

  8. Screening and identification of efficient strain in selenium oxyanions sorption in order to biological wastewater treatment

    Directory of Open Access Journals (Sweden)

    fatemeh yaghoobizadeh

    2016-06-01

    Full Text Available Introduction: Selenium is an element with antioxidant activities that plays roles in thyroid hormone homeostasis, immunity and also fertility. Nevertheless, selenium toxicity (selenosis causes problems for humans such as abnormalities of the nervous system, gastrointestinal problems and hair loss. Thus, this study was performed with the aim of bacterial biosorbent isolation in order to remove selenium contaminant from wastewater. Materials and methods: In this research, at first using modified Luria- Bertani agar (mLBA medium with certain concentration of sodium selenate salt, isolation of bacterial isolates was done from three collected wastewater and sludge samples from Khouzestan industrial factories. After determination of minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC, the sorption capacity and the percentage of metal removal efficiency (%RE were investigated by atomic absorption spectrophotometer using metabolically active and inactive samples belonging to an efficient isolate. Identification was performed by morphological, biochemical and molecular methods. Results: Among 73 attained bacterial isolates at the first stage, 8 selenate oxyanion resistant isolates were gathered. Among these, AMS1-S8 isolate with MIC= 600­mM and MBC= 1200­mM were selected for more studies. Attained results in sorption mechanism determination stage showed that the sorption capacity in metabolically active sample is more than the inactive samples. Based on the identification results, it is revealed that this isolate belongs to the Enterobacter genus. This isolate is deposited as accession JQ965667 in the GeneBank database. Discussion and conclusion: The results showed that active biomass of selected isolate, have most sorption capacity and %RE and among the other isolates, have high partial resistance against selenate. Therefore, it can be a relatively ideal option for the bioremediation of polluted environments.

  9. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, October 2008 and January 2009

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2009-01-01

    This report presents the results for two sampling periods (October 2008 and January 2009) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples. Total selenium also was determined in water column particulates and in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species (western mosquitofish, Gambusia affinis, and sailfin molly, Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 1.00 to 33.6 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 1.52 to 8.26; plankton, 0.79 to 3.66; midges, 2.68 to 50.6; fish, 3.09 to 30.4; detritus, 1.78 to 58.0; and sediment, 0.42 to 10.0.

  10. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, April and July 2008

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2009-01-01

    This report presents the results for two sampling periods (April 2008 and July 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples and total selenium was determined in water column particulates and in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species - western mosquitofish (Gambusia affinis) and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 1.93 to 44.2 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 0.75 to 3.39; plankton, 0.88 to 4.03; midges, 2.52 to 44.3; fish, 3.37 to 18.9; detritus, 1.11 to 13.6; sediment, 0.11 to 8.93.

  11. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, October 2007 and January 2008

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2008-01-01

    This report presents the results for two sampling periods (October 2007 and January 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (selenite, selenate, organoselenium), and total suspended solids were determined in water samples, and total selenium was determined in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species?western mosquitofish (Gambusia affinis) and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 0.97 to 64.5 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 0.95 to 5.99; plankton, 0.15 to 19.3; midges, 1.39 to 15.4; fish, 3.71 to 25.1; detritus, 0.85 to 21.7; sediment, 0.32 to 7.28.

  12. Selenium and Lung Cancer: A Systematic Review and Meta Analysis

    Science.gov (United States)

    Fritz, Heidi; Kennedy, Deborah; Fergusson, Dean; Fernandes, Rochelle; Cooley, Kieran; Seely, Andrew; Sagar, Stephen; Wong, Raimond; Seely, Dugald

    2011-01-01

    Background Selenium is a natural health product widely used in the treatment and prevention of lung cancers, but large chemoprevention trials have yielded conflicting results. We conducted a systematic review of selenium for lung cancers, and assessed potential interactions with conventional therapies. Methods and Findings Two independent reviewers searched six databases from inception to March 2009 for evidence pertaining to the safety and efficacy of selenium for lung cancers. Pubmed and EMBASE were searched to October 2009 for evidence on interactions with chemo- or radiation-therapy. In the efficacy analysis there were nine reports of five RCTs and two biomarker-based studies, 29 reports of 26 observational studies, and 41 preclinical studies. Fifteen human studies, one case report, and 36 preclinical studies were included in the interactions analysis. Based on available evidence, there appears to be a different chemopreventive effect dependent on baseline selenium status, such that selenium supplementation may reduce risk of lung cancers in populations with lower baseline selenium status (serumselenium (≥121.6 ng/mL). Pooling data from two trials yielded no impact to odds of lung cancer, OR 0.93 (95% confidence interval 0.61–1.43); other cancers that were the primary endpoints of these trials, OR 1.51 (95%CI 0.70–3.24); and all-cause-death, OR 0.93 (95%CI 0.79–1.10). In the treatment of lung cancers, selenium may reduce cisplatin-induced nephrotoxicity and side effects associated with radiation therapy. Conclusions Selenium may be effective for lung cancer prevention among individuals with lower selenium status, but at present should not be used as a general strategy for lung cancer prevention. Although promising, more evidence on the ability of selenium to reduce cisplatin and radiation therapy toxicity is required to ensure that therapeutic efficacy is maintained before any broad clinical recommendations can be made in this context. PMID:22073154

  13. Selenoprotein P is the essential selenium transporter for bones.

    Science.gov (United States)

    Pietschmann, Nicole; Rijntjes, Eddy; Hoeg, Antonia; Stoedter, Mette; Schweizer, Ulrich; Seemann, Petra; Schomburg, Lutz

    2014-05-01

    Selenium (Se) plays an important role in bone physiology as best reflected by Kashin-Beck disease, an endemic Se-dependent osteoarthritis. Bone development is delayed in children with mutations in SECIS binding protein 2 (SBP2), a central factor for selenoprotein biosynthesis. Circulating selenoprotein P (SePP) is positively associated with bone turnover in humans, yet its function for bone homeostasis is not known. We have analysed murine models of altered Se metabolism. Most of the known selenoprotein genes and factors needed for selenoprotein biosynthesis are expressed in bones. Bone Se is not associated with the mineral but exclusively with the organic matrix. Genetic ablation of Sepp-expression causes a drastic decline in serum (25-fold) but only a mild reduction in bone (2.5-fold) Se concentrations. Cell-specific expression of a SePP transgene in hepatocytes efficiently restores bone Se levels in Sepp-knockout mice. Of the two known SePP receptors, Lrp8 was detected in bones while Lrp2 was absent. Interestingly, Lrp8 mRNA concentrations were strongly increased in bones of Sepp-knockout mice likely in order to counteract the developing Se deficiency. Our data highlight SePP as the essential Se transporter to bones, and suggest a novel feedback mechanism for preferential uptake of Se in Se-deprived bones, thereby contributing to our understanding of hepatic osteodystrophy and the consistent bone phenotype observed in subjects with inherited selenoprotein biosynthesis mutations.

  14. Disruption prediction at JET

    International Nuclear Information System (INIS)

    Milani, F.

    1998-12-01

    The sudden loss of the plasma magnetic confinement, known as disruption, is one of the major issue in a nuclear fusion machine as JET (Joint European Torus). Disruptions pose very serious problems to the safety of the machine. The energy stored in the plasma is released to the machine structure in few milliseconds resulting in forces that at JET reach several Mega Newtons. The problem is even more severe in the nuclear fusion power station where the forces are in the order of one hundred Mega Newtons. The events that occur during a disruption are still not well understood even if some mechanisms that can lead to a disruption have been identified and can be used to predict them. Unfortunately it is always a combination of these events that generates a disruption and therefore it is not possible to use simple algorithms to predict it. This thesis analyses the possibility of using neural network algorithms to predict plasma disruptions in real time. This involves the determination of plasma parameters every few milliseconds. A plasma boundary reconstruction algorithm, XLOC, has been developed in collaboration with Dr. D. O'Brien and Dr. J. Ellis capable of determining the plasma wall/distance every 2 milliseconds. The XLOC output has been used to develop a multilayer perceptron network to determine plasma parameters as l i and q ψ with which a machine operational space has been experimentally defined. If the limits of this operational space are breached the disruption probability increases considerably. Another approach for prediction disruptions is to use neural network classification methods to define the JET operational space. Two methods have been studied. The first method uses a multilayer perceptron network with softmax activation function for the output layer. This method can be used for classifying the input patterns in various classes. In this case the plasma input patterns have been divided between disrupting and safe patterns, giving the possibility of

  15. Short- and long-term health consequences of sleep disruption.

    Science.gov (United States)

    Medic, Goran; Wille, Micheline; Hemels, Michiel Eh

    2017-01-01

    Sleep plays a vital role in brain function and systemic physiology across many body systems. Problems with sleep are widely prevalent and include deficits in quantity and quality of sleep; sleep problems that impact the continuity of sleep are collectively referred to as sleep disruptions. Numerous factors contribute to sleep disruption, ranging from lifestyle and environmental factors to sleep disorders and other medical conditions. Sleep disruptions have substantial adverse short- and long-term health consequences. A literature search was conducted to provide a nonsystematic review of these health consequences (this review was designed to be nonsystematic to better focus on the topics of interest due to the myriad parameters affected by sleep). Sleep disruption is associated with increased activity of the sympathetic nervous system and hypothalamic-pituitary-adrenal axis, metabolic effects, changes in circadian rhythms, and proinflammatory responses. In otherwise healthy adults, short-term consequences of sleep disruption include increased stress responsivity, somatic pain, reduced quality of life, emotional distress and mood disorders, and cognitive, memory, and performance deficits. For adolescents, psychosocial health, school performance, and risk-taking behaviors are impacted by sleep disruption. Behavioral problems and cognitive functioning are associated with sleep disruption in children. Long-term consequences of sleep disruption in otherwise healthy individuals include hypertension, dyslipidemia, cardiovascular disease, weight-related issues, metabolic syndrome, type 2 diabetes mellitus, and colorectal cancer. All-cause mortality is also increased in men with sleep disturbances. For those with underlying medical conditions, sleep disruption may diminish the health-related quality of life of children and adolescents and may worsen the severity of common gastrointestinal disorders. As a result of the potential consequences of sleep disruption, health care

  16. Density dependence of dielectronic recombination in selenium

    International Nuclear Information System (INIS)

    Hagelstein, P.L.; Rosen, M.D.; Jacobs, V.L.

    1986-01-01

    Dielectronic recombination has been found to be the dominant recombination process in the determination of the ionization balance of selenium near the Ne-like sequence under conditions relevant to the exploding-foil EUV laser plasmas. The dielectronic recombination process tends to populate excited levels, and these levels in turn are more susceptible to subsequent excitation and ionization than are the ground-state ions. If one defines an effective recombination rate which includes, in addition to the primary recombination, the subsequent excitation and ionization of the additional excited-state population due to the primary recombination, then this effective recombination rate can be density-sensitive at relatively low electron density. We present results for this effective dielectronic recombination rate at an electron density of 3 x 10/sup 20/ electrons/cm 3 for recombination from Ne-like to Na-like selenium and from F-like to Ne-like selenium. In the former case, the effective recombination rate coefficient is found to be 1.8 x 10/sup -11/ cm 3 /sec at 1.0 keV, which is to be compared with the zero-density value of 2.8 x 10/sup -11/ cm 3 /sec. In the latter case (F-like to Ne-like), the effective recombination rate coefficient is found to be 1.3 x 10/sup -11/ cm 3 /sec, which is substantially reduced from the zero-density result of 3.3 x 10/sup -11/ cm 3 /sec. We have examined the effects of dielectronic recombination on the laser gain of the dominant Ne-like 3p-3s transitions and have compared our results with those presented by Whitten et al. [Phys. Rev. A 33, 2171 (1986)

  17. Iodine and selenium migration through argillaceous rocks

    International Nuclear Information System (INIS)

    Frasca, Benjamin

    2011-01-01

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

  18. The selenium metabolite methylselenol regulates the expression of ligands that trigger immune activation through the lymphocyte receptor NKG2D

    DEFF Research Database (Denmark)

    Hagemann-Jensen, Michael Henrik; Uhlenbrock, Franziska Katharina; Kehlet, Stephanie

    2014-01-01

    For decades Selenium (Se) research has been focused on the identification of active metabolites, which are crucial for Se chemoprevention of cancer. In this context, the metabolite methylselenol (CH3SeH) is known for its action to selectively kill transformed cells through mechanisms that include...... ligands. A balanced cell-surface expression of NKG2D ligands is considered as an innate barrier against tumor development. Our work therefore indicates that the application of selenium compounds, which are metabolized to CH3SeH, could improve NKG2D-based immune therapy.......: Increased formation of reactive oxygen species (ROS), induction of DNA damage, triggering of apoptosis and the inhibition of angiogenesis. Here, we revealed that CH3SeH modulates cell surface expression of NKG2D ligands. The expression of NKG2D ligands is induced by stress-associated pathways, which occur...

  19. Influence of selenium and vitamin e supplementation during pregnancy on udder health and milk quality in dairy cows at parturition

    Directory of Open Access Journals (Sweden)

    František Zigo

    2017-01-01

    Full Text Available Selenium and vitamin E ranks among very important antioxidant agents protecting the organism from the effect of reactive oxygen forms. The deficiency of both nutrients during pregnancy in cows often result in metabolic disorders and increased of cases of related diseases (mastitis, retained placenta and other reproductive disorders. The aim of the present work was to study the influence of different dose of parenteral administration selenium and vitamin E in dairy cows prior to parturition on selected metabolic parameters, udder health and milk quality. A total in herd of 270 Holstein cattle in east of Slovakia in a two-four lactation-gestation cycle the control group (C and 2 experimental groups (D, D1 were selected. All groups were similarly housed, managed and fed with the diet containing from 36 to 42 mg vitamin E and 0.2 mg.kg-1 Se of DM through the study period. In group D a products containing vitamin E and selenium were administered IM four weeks prior to the expected date of parturition in total dose of 1000 mg of dl-α-tocopherol acetate and of 44 mg sodium selenite per cow, respectively. In group D1 the same products were administered twice, four and two weeks prior to parturition. Blood samples were 4 weeks prior to predicted calving date (the time of treatment, on parturition day and at 14th day after calving for assessment of plasma vitamin E and selenium concentrations. Blood samples of the calves were drawn from jugular vein at birth and first colostrum was also collected. The occurrence of the mastitis and retained placenta during the first 14th day after calving were evaluated in all groups. Higher plasmatic and colostral concentrations of selenium and vitamin E were found only in group with repeat application of Se and vitamin E (D1 collected on the day of parturition. At the 14th day of postpartal period a trend of lower occurrence of mastitis was observed in group D1 compared to D group, administered IM once and control

  20. Agrobacterium-assisted selenium nanoparticles: molecular aspect of antifungal activity

    Science.gov (United States)

    Kumar, Anil; Bera, Smritilekha; Singh, Man; Mondal, Dhananjoy

    2018-03-01

    Selenium nanoparticles (SeNPs) were synthesized through the bioreduction of sodium selenite (Na2SeO3) using gram-negative agrobacterium (AGBT) species. Subsequently, their physicochemical properties (pH, viscosity and surface tension) and medicinal activities as anti-dermatophyte against soil keratinophilic fungi at the molecular level were assessed. UV-visible and FTIR spectroscopic data of the biologically synthesized SeNPs were then recorded for confirming the presence of native biological materials adhered to nanoparticles, which are inherently required to enhance the stability and solubility through inhibition of the nanoparticle’s natural aggregation and agglomeration. The λ max value between 290-300 nm in the absorption spectra of the biogenic materials in different concentrations of the Na2SeO3 corroborated the presence of SeNPs in the solution. The interaction of SeNPs in solution state was further studied through the determination of pH, viscosity and surface tension values of agrobacterium-derived SeNPs in different solvents. The pH value of SeNPs dispersed in water is reported as above 7.0 and the average viscosity, and surface tensions of the SeNPs are appeared as near to the water. The particle size distribution was further determined by DLS and the highest % of particle size of the synthesized SeNPs is found in between 200-300 nm. The anti-dermatophyte activity and molecular interaction with fungi DNA molecules were assessed providing the highest anti-dermatophyte activity at 0.1 M concentration and it is observed that the quantities and qualities of fungi DNA were affected by SeNPs. Considering all the outcomes of the studies together, our findings suggest that agrobacterium-mediated synthesis of SeNPs is dependent on bacterial metabolisms but not on the concentration of Na2SeO3 and are promising selenium-derived species with potential application in the prevention of fungal infection through denaturation of fungi DNA.

  1. Chemoprevention Trial of Selenium and Prostate Cancer

    Science.gov (United States)

    1999-10-01

    use in slowing the growth of prostate cancer. This study will not use selenium as a treatment option for the possible cure of prostate cancer...slice or 1 piece o Q rj Chocolate candy and candy bars o o o o o Q o o c 1 small bar or 1 ounce ._> . ■Q Hard candy, jam, jelly, honey , or...your stream? Have you noticed any stress incontinence? (leakage of urine when sneezing, coughing or laughing) _1 -NOT AT ALL _ 2-LESS THAN 1 IN 5

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

  3. The disruption management model.

    Science.gov (United States)

    McAlister, James

    2011-10-01

    Within all organisations, business continuity disruptions present a set of dilemmas that managers may not have dealt with before in their normal daily duties. The disruption management model provides a simple but effective management tool to enable crisis management teams to stay focused on recovery in the midst of a business continuity incident. The model has four chronological primary headlines, which steer the team through a quick-time crisis decision-making process. The procedure facilitates timely, systematic, rationalised and justified decisions, which can withstand post-event scrutiny. The disruption management model has been thoroughly tested within an emergency services environment and is proven to significantly support clear and concise decision making in a business continuity context.

  4. Emerging and Disruptive Technologies.

    Science.gov (United States)

    Kricka, Larry J

    2016-08-01

    Several emerging or disruptive technologies can be identified that might, at some point in the future, displace established laboratory medicine technologies and practices. These include increased automation in the form of robots, 3-D printing, technology convergence (e.g., plug-in glucose meters for smart phones), new point-of-care technologies (e.g., contact lenses with sensors, digital and wireless enabled pregnancy tests) and testing locations (e.g., Retail Health Clinics, new at-home testing formats), new types of specimens (e.g., cell free DNA), big biology/data (e.g., million genome projects), and new regulations (e.g., for laboratory developed tests). In addition, there are many emerging technologies (e.g., planar arrays, mass spectrometry) that might find even broader application in the future and therefore also disrupt current practice. One interesting source of disruptive technology may prove to be the Qualcomm Tricorder XPrize, currently in its final stages.

  5. Sustainable Disruption Management

    DEFF Research Database (Denmark)

    Vaaben, Bo Valdemar

    The world we live in is globalized. Goods are seldom made in the place where they are used or consumed, and we do increasingly travel to other countries for either business or pleasure. In our everyday lives we rely on well-functioning global transportations systems to continue the standard...... in the same way, when operation is disrupted. Never the less, we may recall that the Suez Canal was closed due to riots in Egypt, that the fuel price was impacted by threats of closing of the Strait of Hormuz, and we do from time to time hear about acts of piracy outside the coast of Somalia. All...... papers combining disruption management and flight planning through an integrated optimization approach. An additional contribution of the thesis is to show how flexible flight speeds can be used to improve recovery from disruptions, while at the same time allowing an airline to trade off fuel costs...

  6. Serum selenium level and risk of lung cancer mortality

    DEFF Research Database (Denmark)

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

    2011-01-01

    Serum selenium has been implicated as a risk factor for lung cancer, but the issue remains unsettled. We tested in a cohort of 3,333 males aged 53 to 74 years the hypothesis that a low serum selenium would be associated with an increased risk of lung cancer mortality.During 16 years, 167 subjects(5.......1%) died from lung cancer; 48 males (5.0%) among males with low serum selenium, 0.4-1.0 μmol·l(-1), n=965, 57 males (5.1%) among males with medium serum selenium, 1.1-1.2 μmol·l(-1), n=1,141, and 62 males (5.1%) among males with high serum selenium, 1.3-3.0 μmol·l(-1), n=1,227. After adjustment for age...... (chronic bronchitis and peak flow), referencing the lowest level of serum selenium HRs were 1.17(0.79-1.75), and 1.43(0.96-2.14), respectively. Among heavy smokers a high serum selenium was associated with a significantly increased risk of lung cancer mortality after taking into account all potential...

  7. Genome-Wide Association Study of Serum Selenium Concentrations

    Directory of Open Access Journals (Sweden)

    Ulrike Peters

    2013-05-01

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

  8. Effects of selenium supplementation on four agricultural crops.

    Science.gov (United States)

    Carvalho, Kathleen M; Gallardo-Williams, Maria T; Benson, Robert F; Martin, Dean F

    2003-01-29

    Agricultural crops can be used either to remediate selenium-contaminated soils or to increase the daily selenium intake of consumers after soil supplementation using inorganic or organic selenium sources. In this study, four agricultural crops were examined for potential selenium enhancement. Soils containing tomato, strawberry, radish, and lettuce plants were supplemented with either an inorganic or an organic form of selenium. Two different soils, i.e., low Se and high Se containing, were also used. Statistically significant differences in appearance, fruit production, and fresh weights of the fruit produced were studied. Next, the amount of selenium retained in the edible fruits, nonedible plant, and soil for each was analyzed by acid digestion followed by hydride generation atomic absorption analysis. Finally, inhibition effects on the seeds of the agricultural plants were studied. The results show that supplementation with an inorganic form of selenium led to higher retention in the plants, with a maximum of 97.5% retained in the edible portion of lettuce plants.

  9. Selenium Nanoparticles for Stress-Resilient Fish and Livestock

    Science.gov (United States)

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

    2015-09-01

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

  10. Early response of plant cell to carbon deprivation: in vivo 31P-NMR spectroscopy shows a quasi-instantaneous disruption on cytosolic sugars, phosphorylated intermediates of energy metabolism, phosphate partitioning, and intracellular pHs.

    Science.gov (United States)

    Gout, Elisabeth; Bligny, Richard; Douce, Roland; Boisson, Anne-Marie; Rivasseau, Corinne

    2011-01-01

    • In plant cells, sugar starvation triggers a cascade of effects at the scale of 1-2 days. However, very early metabolic response has not yet been investigated. • Soluble phosphorus (P) compounds and intracellular pHs were analysed each 2.5 min intervals in heterotrophic sycamore (Acer pseudoplatanus) cells using in vivo phosphorus nuclear magnetic resonance ((31)P-NMR). • Upon external-sugar withdrawal, the glucose 6-P concentration dropped in the cytosol, but not in plastids. The released inorganic phosphate (Pi) accumulated transiently in the cytosol before influx into the vacuole; nucleotide triphosphate concentration doubled, intracellular pH increased and cell respiration decreased. It was deduced that the cytosolic free-sugar concentration was low, corresponding to only 0.5 mM sucrose in sugar-supplied cells. • The release of sugar from the vacuole and from plastids is insufficient to fully sustain the cell metabolism during starvation, particularly in the very short term. Similarly to Pi-starvation, the cell's first response to sugar starvation occurs in the cytosol and is of a metabolic nature. Unlike the cytoplasm, cytosolic homeostasis is not maintained during starvation. The important metabolic changes following cytosolic sugar exhaustion deliver early endogenous signals that may contribute to trigger rescue metabolism. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

  11. Selenium and tellurium as carbon substitutes

    International Nuclear Information System (INIS)

    Knapp, F.F. Jr.

    1980-01-01

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

  12. Biofortification and phytoremediation of selenium in China

    Directory of Open Access Journals (Sweden)

    Zhilin eWu

    2015-03-01

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

  13. Selenium for the Prevention of Cutaneous Melanoma

    Directory of Open Access Journals (Sweden)

    Douglas Grossman

    2013-03-01

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

  14. Selenium for the Prevention of Cutaneous Melanoma

    Science.gov (United States)

    Cassidy, Pamela B.; Fain, Heidi D.; Cassidy, James P.; Tran, Sally M.; Moos, Philip J.; Boucher, Kenneth M.; Gerads, Russell; Florell, Scott R.; Grossman, Douglas; Leachman, Sancy A.

    2013-01-01

    The role of selenium (Se) supplementation in cancer prevention is controversial; effects often depend on the nutritional status of the subject and on the chemical form in which Se is provided. We used a combination of in vitro and in vivo models to study two unique therapeutic windows for intervention in the process of cutaneous melanomagenisis, and to examine the utility of two different chemical forms of Se for prevention and treatment of melanoma. We studied the effects of Se in vitro on UV-induced oxidative stress in melanocytes, and on apoptosis and cell cycle progression in melanoma cells. In vivo, we used the HGF transgenic mouse model of UV-induced melanoma to demonstrate that topical treatment with l-selenomethionine results in a significant delay in the time required for UV-induced melanoma development, but also increases the rate of growth of those tumors once they appear. In a second mouse model, we found that oral administration of high dose methylseleninic acid significantly decreases the size of human melanoma xenografts. Our findings suggest that modestly elevation of selenium levels in the skin might risk acceleration of growth of incipient tumors. Additionally, certain Se compounds administered at very high doses could have utility for the treatment of fully-malignant tumors or prevention of recurrence. PMID:23470450

  15. Biogenesis of Selenium Nanoparticles Using Green Chemistry.

    Science.gov (United States)

    Shoeibi, Sara; Mozdziak, Paul; Golkar-Narenji, Afsaneh

    2017-11-09

    Selenium binds some enzymes such as glutathione peroxidase and thioredoxin reductase, which may be activated in biological infections and oxidative stress. Chemical and physical methods for synthesizing nanoparticles, apart from being expensive, have their own particular risks. However, nanoparticle synthesis through green chemistry is a safe procedure that different biological sources such as bacteria, fungi, yeasts, algae and plants can be the catalyst bed for processing. Synthesis of selenium nanoparticles (SeNPs) by macro/microorganisms causes variation in morphology and shape of the particles is due to diversity of reduction enzymes in organisms. Reducing enzymes of microorganisms by changing the status of redox convert metal ions (Se 2- ) to SeNPs without charge (Se 0 ). Biological activity of SeNPs includes their protective role against DNA oxidation. Because of the biological and industrial properties, SeNPs have wide applications in the fields of medicine, microelectronic, agriculture and animal husbandry. SeNPs can show strong antimicrobial effects on the growth and proliferation of microorganisms in a dose-dependent manner. The objective of this review is to consider SeNPs applications to various organisms.

  16. Microgravimetric Studies of Selenium Electrodeposition Onto Different Substrates

    Directory of Open Access Journals (Sweden)

    Kowalik R.

    2014-10-01

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

  17. Selenium Level and Dyslipidemia in Rural Elderly Chinese

    Science.gov (United States)

    Su, Liqin; Gao, Sujuan; Unverzagt, Frederick W.; Cheng, Yibin; Hake, Ann M.; Xin, Pengju; Chen, Chen; Liu, Jingyi; Ma, Feng; Bian, Jianchao; Li, Ping; Jin, Yinlong

    2015-01-01

    Objective Higher selenium level has been hypothesized to have the potential to reduce the risk of cardiovascular diseases including dyslipidemia. However, results from previous studies are inconsistent. This study aims to determine the association between selenium level and dyslipidemia in elderly Chinese with relatively low selenium status. Methods A cross-sectional study of 1859 participants aged 65 or older from four rural counties in China was conducted. Serum total cholesterol (TC), triglycerides (TG), high density lipoprotein-cholesterol (HDLC) and low-density lipoprotein-cholesterol (LDLC), nail selenium concentration and APOE genotype were measured in all subjects. The four types of dyslipidemia were defined as >5.17mmol/L for High-TC, >1.69 mmol/L for High-TG, >3.36 mmol/L for High-LDLC, and selenium levels and the risk of dyslipidemia. Results Mean nail selenium concentration was 0.465μg/gin this sample. Rates for High-TC, High-LDLC, High-TG, Low-HDLC were 18.13%, 13.23%, 12.21% and 32.76% respectively. Results from logistic models indicated that higher selenium levels were significantly associated with higher risk of High-TC, High-LDLC and lower risk of Low-HDLC adjusting for covariates (p selenium quartile group, participants in selenium quartile groups 2, 3 and 4 had significantly higher rates of High-TC, High-LDLC, High-TG, and lower rate of Low-HDLC adjusting for covariates. No significant association was observed between selenium level and the risk of High-TG. APOEε4 carriers had higher rates of High-TC and High-LDLC. There was no interaction between selenium level and APOE with the rates of dyslipidemia. Conclusions Our results suggest long-term selenium exposure level may be associated with the risk of dyslipidemia in elderly population. Future studies are needed to examine the underlying mechanism of the association. PMID:26380972

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

    CERN Document Server

    Brown, Titus; Huggins, Jason

    2007-01-01

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

  19. Toenail selenium level among healthy residents of two Polish Districts

    International Nuclear Information System (INIS)

    Zukowska, J.; Biziuk, M.; Bode, P.

    2009-01-01

    The goal of this study was to evaluate the selenium mass fraction in toenail clippings taken from random inhabitants living in various areas of the Pomeranian (Northern Poland) and Lubuskie (Western Poland) Districts. Toenail clippings were analyzed by instrumental neutron activation analysis (INAA) giving means of 0.57±0.10 and 0.60±0.16 mg x kg -1 for the two areas, respectively, but the difference was statistically not significant. In additional, it was found that gender, age, body mass index (BMI), smoking, and selenium supplementation are factors with apparent effects to the selenium levels in toenail clippings. (author)

  20. Selenium Level and Dyslipidemia in Rural Elderly Chinese.

    Directory of Open Access Journals (Sweden)

    Liqin Su

    Full Text Available Higher selenium level has been hypothesized to have the potential to reduce the risk of cardiovascular diseases including dyslipidemia. However, results from previous studies are inconsistent. This study aims to determine the association between selenium level and dyslipidemia in elderly Chinese with relatively low selenium status.A cross-sectional study of 1859 participants aged 65 or older from four rural counties in China was conducted. Serum total cholesterol (TC, triglycerides (TG, high density lipoprotein-cholesterol (HDLC and low-density lipoprotein-cholesterol (LDLC, nail selenium concentration and APOE genotype were measured in all subjects. The four types of dyslipidemia were defined as >5.17 mmol/L for High-TC, >1.69 mmol/L for High-TG, >3.36 mmol/L for High-LDLC, and <1.04 mmol/L for Low-HDLC according to Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults. Logistic models adjusting for age, gender, APOE genotype, body mass index, alcohol consumption, smoking, physical activity, medication use for cardiovascular diseases were used to examine the relationship between selenium levels and the risk of dyslipidemia.Mean nail selenium concentration was 0.465 μg/gin this sample. Rates for High-TC, High-LDLC, High-TG, Low-HDLC were 18.13%, 13.23%, 12.21% and 32.76% respectively. Results from logistic models indicated that higher selenium levels were significantly associated with higher risk of High-TC, High-LDLC and lower risk of Low-HDLC adjusting for covariates (p < 0.0001. Compared with the lowest selenium quartile group, participants in selenium quartile groups 2, 3 and 4 had significantly higher rates of High-TC, High-LDLC, High-TG, and lower rate of Low-HDLC adjusting for covariates. No significant association was observed between selenium level and the risk of High-TG. APOEε4 carriers had higher rates of High-TC and High-LDLC. There was no interaction between selenium level and APOE with the rates of

  1. Response of Agronomic Traits of Wheat and Barley to Sources and Different Rates of Selenium in Rainfed Condition

    Directory of Open Access Journals (Sweden)

    N. A Sajedi

    2017-10-01

    Full Text Available Introduction Environmental stresses affect growth, metabolism and crops yield. Drought is an important stress and it decreases crop productivity. Drought stress symptoms vary, depending on intensity and duration of drought and growth stage of the plant. The first response of plant to drought stress is producing the active oxygen species (ROS in cell that these cause injury to membranes and proteins. Selenium (Se application could have beneficial effect on growth and stress tolerance of plants by increasing their activity of antioxidants and reduce the reactive oxygen species over production. Selenium is essential for growth and activities of human and animals. Absorption and accumulation of selenium in plant depend on chemical compound and concentration of selenium in soil. Recent studies have demonstrated that Se increases resistance and antioxidant capacity of plants to various stress. It is reported that selenium application in barley plant no changes the amounts of malondialdehyde and hydrogen peroxide under water deficit stress. The current paper studies the response of agronomic traits of wheat and barley to sources and different rates of selenium in rain fed condition. Materials and Methods In order to investigate response of agronomic traits of wheat and barley to sources and different rates of selenium in rainfed condition, an experiment was carried out as factorial based on randomized complete block design with three replications at the Research Station of Islamic Azad University, Arak Branch, during 2014-2015. Experimental factors were included selenium sources at two levels, Sodium selenate and Selenite, Selenium rates at three levels of zero, 18 and 36 g ha-1 and two crop plants of wheat and barley. The wheat rain fed seed Azar 2 cultivar and Barley cultivar Abidar were hand planted at 15 cm spacing in 6 m rows, with one meter borders between the plots. Foliar application of Se was performed at rate of 18 and 36 g ha-1 at appearance

  2. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, April and July 2007

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2007-01-01

    This report presents the results for two sampling periods during a 4-year monitoring survey to provide a characterization of selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species, and total suspended solids were determined in water samples, and total selenium was determined in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species-western mosquitofish (Gambusia affinis), and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Total selenium concentrations in water for both sampling periods ranged from 1.43 to 47.1 micrograms per liter, predominately as selenate, which is typical of waters leached out of selenium-contaminated marine shales under alkaline and oxidizing conditions. Total selenium concentrations ranged from 0.88 to 20.2 micrograms per gram in biota, and from 0.15 to 28.9 micrograms per gram in detritus and sediment.

  3. Comparative effect of selenium and selenium tolerant microbes on brachiaria reptans l. growth

    International Nuclear Information System (INIS)

    Yasin, M.; Faisal, M.

    2014-01-01

    Brachiaria reptans L. is an annual grass. It is good fodder grass which is distributed in tropical Asia, Kenya, Pakistan and India and introduced throughout the tropics. In present study we determine the growth correlation among B. reptans, selenium (Se) and two Se tolerant bacteria (Bacillus licheniformis-YAP7 and Bacillus cereus-YAP6). Plants treated with Se showed a significant decrease in shoot length (33%) and fresh biomass (41%) compared to control. When plants were co-cultivated in the presence of bacteria or Se and bacteria both the shoot length increased (16-34%) significantly compared to control. B. reptans plants treated with Se have shown a significant decrease in peroxidase contents (59%) compared to control. However, bacterial inoculation of Se treated plants resulted in significant increase in peroxidase contents (113-171%). Selenium treatment caused increase in leaf soluble protein contents compared to control. In conclusion, bacteria can enhance B. reptans growth under Se stress. (author)

  4. Circadian Rhythm Disruption Promotes Lung Tumorigenesis.

    Science.gov (United States)

    Papagiannakopoulos, Thales; Bauer, Matthew R; Davidson, Shawn M; Heimann, Megan; Subbaraj, Lakshmipriya; Bhutkar, Arjun; Bartlebaugh, Jordan; Vander Heiden, Matthew G; Jacks, Tyler

    2016-08-09

    Circadian rhythms are 24-hr oscillations that control a variety of biological processes in living systems, including two hallmarks of cancer, cell division and metabolism. Circadian rhythm disruption by shift work is associated with greater risk for cancer development and poor prognosis, suggesting a putative tumor-suppressive role for circadian rhythm homeostasis. Using a genetically engineered mouse model of lung adenocarcinoma, we have characterized the effects of circadian rhythm disruption on lung tumorigenesis. We demonstrate that both physiologic perturbation (jet lag) and genetic mutation of the central circadian clock components decreased survival and promoted lung tumor growth and progression. The core circadian genes Per2 and Bmal1 were shown to have cell-autonomous tumor-suppressive roles in transformation and lung tumor progression. Loss of the central clock components led to increased c-Myc expression, enhanced proliferation, and metabolic dysregulation. Our findings demonstrate that both systemic and somatic disruption of circadian rhythms contribute to cancer progression. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Chronic psychological stress and high-fat high-fructose diet disrupt metabolic and inflammatory gene networks in the brain, liver, and gut and promote behavioral deficits in mice.

    Science.gov (United States)

    de Sousa Rodrigues, Maria Elizabeth; Bekhbat, Mandakh; Houser, Madelyn C; Chang, Jianjun; Walker, Douglas I; Jones, Dean P; Oller do Nascimento, Claudia M P; Barnum, Christopher J; Tansey, Malú G

    2017-01-01

    The mechanisms underlying the association between chronic psychological stress, development of metabolic syndrome (MetS), and behavioral impairment in obesity are poorly understood. The aim of the present study was to assess the effects of mild chronic psychological stress on metabolic, inflammatory, and behavioral profiles in a mouse model of diet-induced obesity. We hypothesized that (1) high-fat high-fructose diet (HFHF) and psychological stress would synergize to mediate the impact of inflammation on the central nervous system in the presence of behavioral dysfunction, and that (2) HFHF and stress interactions would impact insulin and lipid metabolism. C57Bl/6 male mice underwent a combination of HFHF and two weeks of chronic psychological stress. MetS-related conditions were assessed using untargeted plasma metabolomics, and structural and immune changes in the gut and liver were evaluated. Inflammation was measured in plasma, liver, gut, and brain. Our results show a complex interplay of diet and stress on gut alterations, energetic homeostasis, lipid metabolism, and plasma insulin levels. Psychological stress and HFHF diet promoted changes in intestinal tight junctions proteins and increases in insulin resistance and plasma cholesterol, and impacted the RNA expression of inflammatory factors in the hippocampus. Stress promoted an adaptive anti-inflammatory profile in the hippocampus that was abolished by diet treatment. HFHF increased hippocampal and hepatic Lcn2 mRNA expression as well as LCN2 plasma levels. Behavioral changes were associated with HFHF and stress. Collectively, these results suggest that diet and stress as pervasive factors exacerbate MetS-related conditions through an inflammatory mechanism that ultimately can impact behavior. This rodent model may prove useful for identification of possible biomarkers and therapeutic targets to treat metabolic syndrome and mood disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Effect of selenium-enriched organic material amendment on selenium fraction transformation and bioavailability in soil.

    Science.gov (United States)

    Wang, Dan; Dinh, Quang Toan; Anh Thu, Tran Thi; Zhou, Fei; Yang, Wenxiao; Wang, Mengke; Song, Weiwei; Liang, Dongli

    2018-05-01

    To exploit the plant byproducts from selenium (Se) biofortification and reduce environmental risk of inorganic Se fertilizer, pot experiment was conducted in this study. The effects of Se-enriched wheat (Triticum aestivum L.) straw (WS + Se) and pak choi (Brassica chinensis L.) (P + Se) amendment on organo-selenium speciation transformation in soil and its bioavailability was evaluated by pak choi uptake. The Se contents of the cultivated pak choi in treatments amended with the same amount of Se-enriched wheat straw and pak choi were 1.7 and 9.7 times in the shoots and 2.3 and 6.3 times in the roots compared with control treatment. Soil respiration rate was significantly increased after all organic material amendment in soil (p organic materials and thus resulted in soluble Se (SOL-Se), exchangeable Se (EX-Se), and fulvic acid-bound Se (FA-Se) fraction increasing by 25.2-29.2%, 9-13.8%, and 4.92-8.28%, respectively. In addition, both Pearson correlation and cluster analysis showed that EX-Se and FA-Se were better indicators for soil Se availability in organic material amendment soils. The Marquardt-Levenberg Model well described the dynamic kinetics of FA-Se content after Se-enriched organic material amendment in soil mainly because of the mineralization of organic carbon and organo-selenium. The utilization of Se in P + Se treatment was significantly higher than those in WS + Se treatment because of the different mineralization rates and the amount of FA-Se in soil. Se-enriched organic materials amendment can not only increase the availability of selenium in soil but also avoid the waste of valuable Se source. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. No-carrier-added labeling of the neuroprotective Ebselen with selenium-73 and selenium-75.

    Science.gov (United States)

    Helfer, Andreas; Ermert, Johannes; Humpert, Sven; Coenen, Heinz H

    2015-03-01

    Selenium-73 is a positron emitting non-standard radionuclide, which is suitable for positron emission tomography. A copper-catalyzed reaction allowed no-carrier-added labeling of the anti-inflammatory seleno-organic compound Ebselen with (73) Se and (75) Se under addition of sulfur carrier in a one-step reaction. The new authentically labeled radioselenium molecule is thus available for preclinical evaluation and positron emission tomography studies. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Statistical analysis of JET disruptions

    International Nuclear Information System (INIS)

    Tanga, A.; Johnson, M.F.

    1991-07-01

    In the operation of JET and of any tokamak many discharges are terminated by a major disruption. The disruptive termination of a discharge is usually an unwanted event which may cause damage to the structure of the vessel. In a reactor disruptions are potentially a very serious problem, hence the importance of studying them and devising methods to avoid disruptions. Statistical information has been collected about the disruptions which have occurred at JET over a long span of operations. The analysis is focused on the operational aspects of the disruptions rather than on the underlining physics. (Author)

  9. Pesticides Provoke Endocrine Disruption A Review

    International Nuclear Information System (INIS)

    Aly, M.A.S.

    2006-01-01

    Increasing numbers of environmental chemicals,including pesticides, have the ability to produce endocrine disruption by various mechanisms. such substances may affect hormone secretion from an endocrine gland and may alter the rate of hormone elimination from the body. environmental chemicals may also disrupt regulatory feedback mechanisms that exist between two endocrine organs; or may interact with a hormone receptor either by mimicking or antagonizing the actions of the natural hormone. these chemicals are referred to endocrine disruptive chemicals (EDC's). EDC's act to alter the blood hormone levels or the subsequent action of hormones . the use of radioimmunoassay(RIA) constitutes a superior and unrivalled tool for the determination and quantification of hormones.the endocrine system participates in virtually all important functions of an organism, such as sexual differentiation before birth, sexual maturation during puberty, reproduction in adulthood, growth, metabolism, digestion, cardiovascular function and excretion. hormones are also implicated in the etiology of certain cancers of hormone- dependent tissues, such as those of the breast, uterus, and prostate gland. therefore, endocrine disruption can potentially produce widespread effects. scientists should not stick to the past belief which presumes that pesticides have limited effect on some hormones. A paradigm shift in which a wider vision of understanding of the wholesome complex effects of pesticides on the whole body rather than a narrow limited understanding should take place

  10. Endocrine Disrupting Chemicals and Disease Susceptibility

    Science.gov (United States)

    Schug, Thaddeus T.; Janesick, Amanda; Blumberg, Bruce; Heindel, Jerrold J.

    2011-01-01

    Environmental chemicals have significant impacts on biological systems. Chemical exposures during early stages of development can disrupt normal patterns of development and thus dramatically alter disease susceptibility later in life. Endocrine disrupting chemicals (EDCs) interfere with the body's endocrine system and produce adverse developmental, reproductive, neurological, cardiovascular, metabolic and immune effects in humans. A wide range of substances, both natural and man-made, are thought to cause endocrine disruption, including pharmaceuticals, dioxin and dioxin-like compounds, polychlorinated biphenyls, DDT and other pesticides, and components of plastics such as bisphenol A (BPA) and phthalates. EDCs are found in many everyday products– including plastic bottles, metal food cans, detergents, flame retardants, food additives, toys, cosmetics, and pesticides. EDCs interfere with the synthesis, secretion, transport, activity, or elimination of natural hormones. This interference can block or mimic hormone action, causing a wide range of effects. This review focuses on the mechanisms and modes of action by which EDCs alter hormone signaling. It also includes brief overviews of select disease endpoints associated with endocrine disruption. PMID:21899826

  11. Evaluation of the inorganic selenium biotransformation in selenium-enriched yogurt by HPLC-ICP-MS.

    Science.gov (United States)

    Alzate, Adriana; Cañas, Benito; Pérez-Munguía, Sandra; Hernández-Mendoza, Hector; Pérez-Conde, Concepción; Gutiérrez, Ana Maria; Cámara, Carmen

    2007-11-28

    Selenium is an essential element in the human diet. Interestingly, there has been an increased consumption of dietary supplements containing this element in the form of either inorganic or organic compounds. The effect of using selenium as a dietary supplement in yogurt has been evaluated. For this purpose, different concentrations of inorganic Se (ranging from 0.2 to 5000 microg g(-1)) have been added to milk before the fermentation process. Biotransformation of inorganic Se into organic species has been carefully evaluated by ion-exchange, reversed-phase, or size-exclusion chromatography, coupled to inductively coupled plasma mass spectrometry (ICP-MS). Yogurt fermentation in the presence of up to 2 microg g(-1) of Se(IV) produces a complete incorporation of this element into proteins as has been demonstrated applying a dialysis procedure. Analysis by SEC-ICP-MS showed that most of them have a molecular mass in the range of 30-70 kDa. Species determination after enzymatic hydrolysis has allowed the identification of Se-cystine using two different chromatographic systems. The biotransformation process that takes place during yogurt fermentation is very attractive because yogurt can act as a source of selenium supplementation.

  12. Effects of Selenium Yeast on Blood Glucose and Antioxidant ...

    African Journals Online (AJOL)

    olayemitoyin

    Biomarkers in Cholesterol Fed Diet Induced Type 2 Diabetes. Mellitus in Wistar Rats. ... Keywords: Cholesterol diet; Diabetes Mellitus; Selenium yeast; SOD; CAT; GPx. ©Physiological ..... relationship with different diseases. Science Tot.

  13. Mixed Surfactant Template Method for Preparation of Nanometer Selenium

    Directory of Open Access Journals (Sweden)

    Zhi-Lin Li

    2009-01-01

    Full Text Available Selenium nanoparticles have been synthesized in an aqueous solution by using sodium dodecyl sulfate and polyvinyl alcohol as a soft template. The factors on synthesis, such as reaction time, concentration of reactants and ultrasonic irradiation were studied. The uniform stable selenium nanospheres were obstained in the conditions of 1.0 (mass fraction sodium dodecyl sulfate, 1.0 (mass fraction polyvinyl alcohol, n(Vc:n(H2SeO3=7:1 and 7 minutes after the initiation of the reaction at room temperature. The average particle size of selenium is about 30 nm. The product was characterized by UV and TEM. Finally the applications of the red element nanometer selenium in anti-older cosmetics are presented.

  14. Catalytic oxidant scavenging by selenium-containing compounds

    DEFF Research Database (Denmark)

    Carroll, Luke; Pattison, David I; Fu, Shanlin

    2017-01-01

    Myeloperoxidase produces strong oxidants during the immune response to destroy invading pathogens. However, these oxidants can also cause tissue damage, which contributes to the development of numerous inflammatory diseases. Selenium containing compounds, including selenomethionine (SeMet) and 1,...

  15. Arsenic, chromium, copper, iron, manganese, lead, selenium and ...

    African Journals Online (AJOL)

    Arsenic, chromium, copper, iron, manganese, lead, selenium and zinc in the tissues of the largemouth yellowfish, Labeobarbus kimberleyensis (Gilchrist and Thompson, 1913), from the Vaal Dam, South Africa, and associated consumption risks.

  16. Serum Selenium levels in Essential hypertension among adults at ...

    African Journals Online (AJOL)

    communicable diseases. In the current medical literature it is not clear on the serum selenium levels among essential hypertensive patients in Zambia despite evidence in literature of its role in development of hypertension. The present study ...

  17. Copper and selenium supplementation of ewes grazing on pastures ...

    African Journals Online (AJOL)

    ,09 pg Se/g DM, het bloedseleniumkonsentrasiesvaono ie verhoog, maar het min invloed op die lewer- en nierseleniumkonsentrasievsa n lammers kort na geboorte gehad. Keywords: Blood selenium, copper supplementiation, fertility, plasma ...

  18. Distribution and retention of inhaled selenium compounds in the rat

    International Nuclear Information System (INIS)

    Burkstaller, M.A.; Cuddihy, R.G.

    1978-01-01

    Selenium containing compounds released into the atmosphere during coal combustion are principally of the elemental form or the dioxide. These compounds differ greatly in their chemical properties. Fischer-344 rats were exposed via inhalation to both the dioxide and the red elemental form of selenium. Subsequently, measurements were made of internal absorption, organ distribution and retention, and modes of excretion. A radiotracer, 75 Se, was incorporated into the aerosol to facilitate these measurements. Retention of both aerosols in the total body showed long term components with half lives of 43 and 15 days accounting for 25 to 35% of the initially deposited selenium. Excretion occurred principally by way of urine. For both aerosols, selenium absorbed into the systemic circulation was mainly found in the liver, kidney, blood, gastrointestinal tract and bone

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

    International Nuclear Information System (INIS)

    Monks, R.; Riley, A.L.M.

    1981-01-01

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

  20. The Determination of Selenium in Blood. RCN Report

    International Nuclear Information System (INIS)

    Japenga, J.; Das, H.A.; Hoede, D.; Zonderhuis, J.

    1971-12-01

    A procedure for the determination of selenium by neutron activation analysis in blood is given. The radionuclide used is 75 Se (T½ = 120 d). Chemical separation is performed by precipitation of the element. (author)

  1. Selenium concentration of maize grain in South Africa and possible ...

    African Journals Online (AJOL)

    Casey W

    reviewed paper: Proc. ... maize grain is a staple food for humans and a major ingredient in the diets of intensively fed livestock. Therefore, Se in ..... Dietary reference intakes for vitamin C, vitamin E, selenium and carotenoids. National Research.

  2. Effect of selenium on malignant tumor cells of brain.

    Science.gov (United States)

    Zhu, Z; Kimura, M; Itokawa, Y; Nakatsu, S; Oda, Y; Kikuchi, H

    1995-07-01

    Some reports have demonstrated that selenium can inhibit tumorigenesis in some tissues of animal. However, little is known about the inhibitory effect on malignant tumor cells of brain. The purpose of our study was to determine the biological effect of selenium on growth of rat glioma and human glioblastoma cell lines. Cell lines C6 and A172 were obtained from Japanese Cancer Research Resources Bank, Tokyo, Japan (JCRB). Cells were cultured in Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% fetal calf serum at 37 degrees C in a humidified atmosphere of air and 5% CO2. Antiproliferative effects of selenium were evaluated using growth rate assay quantifying cell number by MTT assay. An antiproliferative effect of selenium was found in two cell lines, which was more effective on human A172 glioblastoma and less effective on rat C6 glioma.

  3. 6. THE ROLE OF SELENIUM IN HUMAN IMMUNITY

    African Journals Online (AJOL)

    Esem

    lymphocyte (CD3+) immune response was enhanced in persons that ... Selenium and Disease Conditions ... In China, Keshan and Kashin-Beck diseases are human. 21,22,23 ... and cytotoxic cell activities that act against the HIV virus.

  4. Selenium derivatives of thyroxine and tri-iodothyronine

    International Nuclear Information System (INIS)

    Cree, G.M.

    1980-01-01

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

  5. Assessment of selenium bioavailability from naturally produced high-selenium soy foods in selenium-deficient rats.

    Science.gov (United States)

    Yan, Lin; Reeves, Philip G; Johnson, LuAnn K

    2010-10-01

    We assessed the bioavailability of selenium (Se) from a protein isolate and tofu (bean curd) prepared from naturally produced high-Se soybeans. The Se concentrations of the soybeans, the protein isolate and tofu were 5.2±0.2, 11.4±0.1 and 7.4±0.1mg/kg, respectively. Male weanling Sprague-Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet (4.1μg Se/kg) for 56 days, and then they were replenished with Se for an additional 50 days by feeding them the same diet containing 14, 24 or 30 μg Se/kg from the protein isolate or 13, 23 or 31 μg Se/kg from tofu, respectively. l-Selenomethionine (SeMet) was used as a reference. 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 the protein isolate and tofu to those for SeMet by using a slope-ratio method. Dietary supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in glutathione peroxidase activities in blood and liver and in thioredoxin reductase activity in liver. Furthermore, supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in the Se concentrations of plasma, liver, muscle and kidneys. These results indicated an overall bioavailability of approximately 101% for Se from the protein isolate and 94% from tofu, relative to SeMet. We conclude that Se from naturally produced high-Se soybeans is highly bioavailable in this model and that high-Se soybeans may be a good dietary source of Se. Published by Elsevier GmbH.

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

    Science.gov (United States)

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

    2015-01-01

    A number of contaminants affect fish health, including mercury and selenium, and the selenium: mercury molar ratio. Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for consumption of saltwater fish. Yet the relative ameliorating effects of selenium on toxicity within fish have not been examined, nor has the molar ratio in different tissues, (i.e. brain). We examined mercury and selenium levels in brain, kidney, liver, red and white muscle, and skin and scales in bluefish (Pomatomus saltatrix) from New Jersey to determine whether there were toxic levels of either metal, and we computed the selenium: mercury molar ratios by tissues. Total mercury averaged 0.32 ± 0.02 ppm wet weight in edible muscle and 0.09 ± 0.01 ppm in brain. Selenium concentration averaged 0.37 ± 0.03 in muscle and 0.36 ± 0.03 ppm in brain. There were significant differences in levels of mercury, selenium, and selenium: mercury molar ratios, among tissues. Mercury and selenium levels were correlated in kidney and skin/scales. Mercury levels were highest in kidney, intermediate in muscle and liver, and lowest in brain and skin/scales; selenium levels were also highest in kidney, intermediate in liver, and were an order of magnitude lower in the white muscle and brain. Mercury levels in muscle, kidney and skin/scales were positively correlated with fish size (length). Selenium levels in muscle, kidney and liver were positively correlated with fish length, but in brain; selenium levels were negatively correlated with fish length. The selenium: mercury molar ratio was negatively correlated with fish length for white muscle, liver, kidney, and brain, particularly for fish over 50 cm in length, suggesting that older fish experience less protective advantages of selenium against mercury toxicity than smaller fish, and that consumers of bluefish similarly receive less advantage from eating larger fish. PMID:23202378

  7. 21 CFR 520.2100 - Selenium, vitamin E capsules.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Selenium, vitamin E capsules. 520.2100 Section 520... to 1 milligram of selenium) and 56.2 milligrams of vitamin E (68 I.U.) (as d-alpha tocopheryl acid... of vitamin E (17 I.U.) (as d-alpha tocopheryl acid succinate.) (b) Sponsor. See No. 000061 in § 510...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-12-31

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

  9. Study of damages induced by fungicide propiconazole on testicular tissue and process of spermatogenesis and protective effects of selenium in male Sprague Dawley rat

    Directory of Open Access Journals (Sweden)

    H Mohsenikouchesfehani

    2015-04-01

    Full Text Available Background & aim: Propiconazole is an herbal fungicide which is used as a tropical and systematic drug for fungal infection and also as an agricultural chemical for protection and preservation of fruits, vegetables and grains. The aim of this study was to assess the efficacy of fungicides propiconazol and possible protective effects of selenium on testes tissue. Methods: The present expremental trail study was conducted on forty rats which were divided into ten groups of four including control , sham (solvent of propiconazole, distilled water, solvent of selenium (normal saline and seven experimental groups : group 1 received 0.5 mg/kg/day of selenium, groups 2,3,4 received three doses of 10,50,75 mg/kg/day of Propiconazole, and groups 5,6,7 received three doses of 10, 50, 75 mg/kg/day of propiconazole with 0.5 mg/kg/day of selenium toevaluate. The administration was done intrapritoneal for two weeks in an alternatively fashion. After determining the level of LH, FSH, Testosterone, sperm was counted by hemocitometer. Data were analyzed by the SPSS software using ANOVA test. Results: No significant differences was observed in the level of hormones in the experimental groups2-7 compared with the control group, but the number of sertoli cells, spermatogonia , primary spermatocyte , spermatid and sperm decreased significantly in comparison with the control group (p<0.05. Conclusion: The decrease in numbers of counted sperm indicates that propiconazole has disrupted the production process of these cells and selenium was unable to improve that.

  10. Sleep disruption and the sequelae associated with traumatic brain injury.

    Science.gov (United States)

    Lucke-Wold, Brandon P; Smith, Kelly E; Nguyen, Linda; Turner, Ryan C; Logsdon, Aric F; Jackson, Garrett J; Huber, Jason D; Rosen, Charles L; Miller, Diane B

    2015-08-01

    Sleep disruption, which includes a loss of sleep as well as poor quality fragmented sleep, frequently follows traumatic brain injury (TBI) impacting a large number of patients each year in the United States. Fragmented and/or disrupted sleep can worsen neuropsychiatric, behavioral, and physical symptoms of TBI. Additionally, sleep disruption impairs recovery and can lead to cognitive decline. The most common sleep disruption following TBI is insomnia, which is difficulty staying asleep. The consequences of disrupted sleep following injury range from deranged metabolomics and blood brain barrier compromise to altered neuroplasticity and degeneration. There are several theories for why sleep is necessary (e.g., glymphatic clearance and metabolic regulation) and these may help explain how sleep disruption contributes to degeneration within the brain. Experimental data indicate disrupted sleep allows hyperphosphorylated tau and amyloid β plaques to accumulate. As sleep disruption may act as a cellular stressor, target areas warranting further scientific investigation include the increase in endoplasmic reticulum and oxidative stress following acute periods of sleep deprivation. Potential treatment options for restoring the normal sleep cycle include melatonin derivatives and cognitive behavioral therapy. Published by Elsevier Ltd.

  11. The secretion, synthesis, and metabolism of cortisol and its downstream genes in the H-P-I axis of rare minnows (Gobiocypris rarus) are disrupted by acute waterborne cadmium exposure.

    Science.gov (United States)

    Liu, Xiao-Hong; Xie, Bi-Wen; Wang, Zhi-Jian; Jin, Li; Zhang, Yao-Guang

    2016-01-01

    The H (hypothalamic)-P (pituitary)-I (interrenal) axis plays a critical role in the fish stress response and is regulated by several factors. Cadmium (Cd) is one of the most toxic heavy metals in the world, but its effects on the H-P-I axis of teleosts are largely unknown. Using rare minnow (Gobiocypris rarus) as an experimental animal, we found that Cd only disrupted the secretion and synthesis of cortisol. Neither hormones at the H or P level nor the expressions of their receptor genes (corticotropin-releasing hormone receptor (CRHR) and melanocortin receptor 2 (MC2R)) were affected. Steroidogenic acute regulator (StAR), CYP11A1 and CYP11B1, which encode the key enzymes in the cortisol synthesis pathway, were significantly up-regulated in the kidney (including the head kidney). The level of 11β-HSD2, which is required for the conversion of cortisol to cortisone, was increased in the kidney, intestine, brain, and hepatopancreas, whereas the expression of 11β-HSD1, which encodes the reverse conversion enzyme, was increased in the gill, kidney and almost unchanged in other tissues. The enzyme activity concentration of 11β-HSD2 was increased in the kidney as well. The level of glucocorticoid receptor (GR) decreased in the intestine, gill and muscle, and the key GR regulator FK506 binding protein5 (FKBP5) was up-regulated in the GR-decreased tissues, whereas the level of nuclear receptor co-repressor 1 (NCoR1), another GR regulator remained almost unchanged. Thus, GR, FKBP5 and 11β-HSD2 may be involved in Cd-induced cortisol disruption. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Biological effects of selenium and relationships with carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Diplock, A.T.

    1984-01-01

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

  13. Nuclear-based methods for the study of selenium

    International Nuclear Information System (INIS)

    Spyrou, N.M.; Akanle, O.A.; Dhani, A.

    1988-01-01

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

  14. Selenium in the Blackfoot, Salt, and Bear River Watersheds

    Science.gov (United States)

    Hamilton, S.J.; Buhl, K.J.

    2005-01-01

    Nine stream sites in the Blackfoot River, Salt River, and Bear River watersheds in southeast Idaho, USA were sampled in May 2001 for water, surficial sediment, aquatic plants, aquatic invertebrates, and fish. Selenium was measured in these aquatic ecosystem components, and a hazard assessment was performed on the data. Water quality characteristics such as pH, hardness, and specific conductance were relatively uniform among the nine sites. Of the aquatic components assessed, water was the least contaminated with selenium because measured concentrations were below the national water quality criterion of 5 μ g/L at eight of the nine sites. In contrast, selenium was elevated in sediment, aquatic plants, aquatic invertebrates, and fish from several sites, suggesting deposition in sediments and food web cycling through plants and invertebrates. Selenium was elevated to concentrations of concern in fish at eight sites (> 4 μ g/g in whole body). A hazard assessment of selenium in the aquatic environment suggested a moderate hazard at upper Angus Creek (UAC) and Smoky Creek (SC), and high hazard at Little Blackfoot River (LiB), Blackfoot River gaging station (BGS), State Land Creek (SLC), upper (UGC) and lower Georgetown Creek (LGC), Deer Creek (DC), and Crow Creek (CC). The results of this study indicate that selenium concentrations from the phosphate mining area of southeast Idaho were sufficiently elevated in several ecosystem components to cause adverse effects to aquatic resources in southeastern Idaho.

  15. The Thermodynamics of Selenium Minerals in Near-Surface Environments

    Directory of Open Access Journals (Sweden)

    Vladimir Krivovichev

    2017-10-01

    Full Text Available Selenium compounds are relatively rare as minerals; there are presently only 118 known mineral species. This work is intended to codify and systematize the data of mineral systems and the thermodynamics of selenium minerals, which are unstable (selenides or formed in near-surface environments (selenites, where the behavior of selenium is controlled by variations of the redox potential and the acidity of solutions at low temperatures and pressures. These parameters determine the migration of selenium and its precipitation as various solid phases. All selenium minerals are divided into four groups—native selenium, oxide, selenides, and oxysalts—anhydrous selenites (I and hydrous selenites and selenates (II. Within each of the groups, minerals are codified according to the minimum number of independent elements necessary to define the composition of the mineral system. Eh–pH diagrams were calculated and plotted using the Geochemist’s Workbench (GMB 9.0 software package. The Eh–pH diagrams of the Me–Se–H2O systems (where Me = Co, Ni, Fe, Cu, Pb, Zn, Cd, Hg, Ag, Bi, As, Sb, Al and Ca were plotted for the average contents of these elements in acidic waters in the oxidation zones of sulfide deposits. The possibility of the formation of Zn, Cd, Ag and Hg selenites under natural oxidation conditions in near surface environments is discussed.

  16. Stunting, selenium deficiency and anemia are associated with poor cognitive performance in preschool children from rural Ethiopia.

    Science.gov (United States)

    Gashu, Dawd; Stoecker, Barbara J; Bougma, Karim; Adish, Abdulaziz; Haki, Gulelat D; Marquis, Grace S

    2016-04-12

    Anthropometric characteristics and iron status affect cognitive performance in children. In addition, selenium can influence cognitive outcomes; protection of the brain from oxidative stress and its role in thyroid hormone metabolism are putative mechanisms. To investigate their association with cognitive performance, anthropometric indicators, iron biomarkers, and serum selenium of children (n = 541) of 54-60mo of age from rural Ethiopia were assessed. Cognitive assessment was conducted with the administration of two reasoning subtests of the Wechsler Preschool and Primary Scale of Intelligence and the school readiness test. Stunting was found in 41.4 % of children, 28.7 % were underweight, and 6.3 % were wasted. The mean score of stunted children was lower than that of non-stunted children on non-verbal reasoning (7.0 ± 3.2vs7.9 ± 3.1; p = 0.01) and the school readiness tests (4.3 ± 2.2 vs 3.3 ± 2.1; p 0.05). Selenium deficient children had lower scores on all cognitive tests than normal children (p malnutrition and micronutrient deficiency and address cognitive development in children.

  17. Selenium accumulation in the cockle Anadara trapezia

    International Nuclear Information System (INIS)

    Jolley, Dianne F.; Maher, William A.; Kyd, Jennelle

    2004-01-01

    An extensive study on Se accumulation in a population of Anadara trapezia from a marine lake is reported. The effects of organism mass, gender, reproductive cycle, and season on Se accumulation and tissue distribution were investigated. Analyses showed that gender and reproductive cycle had no significant effect on Se accumulation. A. trapezia showed a strong positive correlation between Se burden and tissue mass. Constant Se concentrations were observed within individual populations but varied spatially with sediment Se concentrations. Se concentrations in tissues decreased from gills > gonad/intestine > mantle > muscle > foot, which remained constant over 12 months, however, significantly lower concentrations were observed in the summer compared to winter. A. trapezia is a good biomonitor for Se, as gender and size do not effect concentration, however, season of collection must be reported if changes in Se bioavailability are to be identified in short term studies, or during intersite comparisons. - Capsule: The marine bivalve Anadara trapezia is a good bioindicator for marine selenium contamination

  18. Selenium content in milk and diary samples

    International Nuclear Information System (INIS)

    Kira, Carmen S.; Maihara, Vera A.

    2005-01-01

    Food is the primary source of Se for human beings. As such determining Se levels in foodstuffs become very important. However, information concerning Se levels in different sources of nutrition in different country, particularly in Brazil, is limited. Instrumental Neutron Activation Analysis (INAA) has been used to effectively determine micronutrient levels in foodstuffs, such as milk and dairy samples. The advantage of using the INAA technique is that the samples do not require previous dissolution before analysis. In this study, INAA was applied to determine Se concentration in milk and dairy products. The samples were acquired in the markets of Sao Paulo city. After a 8-hour irradiation in the research reactor IEA-R1, selenium was analyzed by gamma-ray spectrometry. Methodology validation was done analyzing NIST reference materials (Whole Milk Powder and Non Fat Milk Powder). Se concentrations in the sample analyzed were below 0.300 μg g -1 . (author)

  19. Selenium implantation in epitaxial gallium arsenide layers

    International Nuclear Information System (INIS)

    Inada, T.; Tokunaga, K.; Taka, S.; Yuge, Y.; Kohzu, H.

    1981-01-01

    Selenium implantation at room temperature in S-doped epitaxial GaAs layers as a means of the formation of n + layers has been investigated. Doping profiles for Se-implanted layers have been examined by a C-V technique and/or a differential Hall effect method. It has been shown that n + layers with a maximum carrier concentration of approx. equal to1.5 x 10 18 cm -3 can be formed by implantation followed by a 15 min annealing at 950 0 C. Contact resistance of ohmic electrodes is reduced by use of the Se-implanted n + layers, resulting in the improvement on GaAs FET performance. Measured minimum noise figure of the Se-implanted GaAs FETs is 0.74 dB at 4 GHz. (orig.)

  20. Emerging and Disruptive Technologies

    OpenAIRE

    Kricka, Larry J.

    2016-01-01

    Several emerging or disruptive technologies can be identified that might, at some point in the future, displace established laboratory medicine technologies and practices. These include increased automation in the form of robots, 3-D printing, technology convergence (e.g., plug-in glucose meters for smart phones), new point-of-care technologies (e.g., contact lenses with sensors, digital and wireless enabled pregnancy tests) and testing locations (e.g., Retail Health Clinics, new at-home test...

  1. Effect of selenium supplementation on thyroid antibodies

    International Nuclear Information System (INIS)

    Kvicala, J.; Hrda, P.; Zamrazil, V.; Nemecek, J.; Hill, M.; Jiranek, V.

    2009-01-01

    Selenium is an essential component of selenoproteins, enzymes with extensive regulatory and protective effect in organism. Immunological effects of Se are documented and are distinct even above concentrations necessary for maximal activity of selenoenzymes. Therefore, we investigated effect of supplementation by 100 μg of yeast-bound Se on concentrations of thyroid autoantibodies TPOAb and TgAb in the group of 253 seniors living in the Asylum Houses of South Bohemia. Increase of serum selenium from 59 to 150 μg Se/L serum in supplemented group and from 59 to 72 μg Se/L serum in group with placebo were detected by Instrumental Neutron Activation Analysis (INAA) and proved increased Se intake during the trial. Autoantibodies were analyzed by ELISA at the beginning of the trial and after 1 year. Statistical evaluation of results in whole groups (regardless of increased autoantibodies) by ANOVA manifested significant decrease of TPOAb and TgAb in non-supplemented group while supplementation did not effect serum autoantibodies concentrations. Evaluation of groups of seniors created from those with increased autoantibodies, ANOVA demonstrated decrease of TPOAb in both groups but Se supplementation did not affect the decrease. In opposite, TgAb increased significantly and Se supplementation led to higher increase of TgAb. Recent results of possibility to decrease serum concentration of TPOAb proved this effect only for high TPOAb concentrations and for higher Se supplements. From this point of view, it is necessary to conduct subsequent trials with the patients with autoimmune thyreoiditis with different levels of autoantibodies and detect also serum Se levels. (author)

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

    Directory of Open Access Journals (Sweden)

    Arlindo Saran Netto

    2013-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2004-01-01

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

  4. Use of sodium hydroxide treated selenium deficient barley to induce vitamin E and selenium deficiency in yearling cattle.

    Science.gov (United States)

    Rice, D A; McMurray, C H

    1986-02-15

    Selenium deficient barley grown in Northern Ireland was treated with sodium hydroxide to deplete it of vitamin E. Housed cattle fed a complete diet based on this treated barley developed nutritional degenerative myopathy, showing that spontaneous myopathy in yearling cattle can be the result of vitamin E and selenium deficiency alone. The diet used is as effective and cheaper than others presently in use for inducing degenerative myopathy.

  5. Uranium and selenium resistance in Cupriavidus metallidurans CH34

    International Nuclear Information System (INIS)

    Avoscan, L.; Untereiner, G.; Carriere, M.; Gouget, B.; Degrouard, J.

    2007-01-01

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

  6. Determination of human and Sprague-Dawley rat trimethylseleonium ion and total selenium urine concentrations from endogenous body selenium pool by neutron activation analysis

    International Nuclear Information System (INIS)

    Blotcky, A.J.; Claassen, J.P.; Rack, E.P.

    1992-01-01

    This study determined trimethylselenonium ion [TMSe,(CH 3 ) 3 Se + ] and total organic selenium cationic species urinary excretion values for healthy human subjects and Sprague-Dawley rats fed regular diets. The only source of TMSe was from the endogenous selenium body pool. Total selenium concentration in urine was determined by instrumental neutron activation analysis. TMSe and total selenium cationic species concentrations and percent of total selenium urine excretion were determined by chemical neutron activation analysis and coupled anion-cation exchange chromatography and anion-exchange chromatography, respectively. Within experimental error, mean values for TMSe and cationic species as percent selenium were comparable for both human subjects and Sprague-Dawley rats. This study suggested that TMSe excreated in urine by healthy human subjects and Sprague-Dawley rats fed a normal diet is not a minor but a general metabolite of selenium ingested in a normal diet. (author) 27 refs.; 1 fig.; 2 tabs

  7. Disrupting the Industry with Play

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop

    2016-01-01

    or two ago. This is significantly disrupting the industry in several market sectors. This paper describes the components of the playware and embodied artificial intelligence research that has led to disruption in the industrial robotics sector, and which points to the next disruption of the health care...

  8. Wound Disruption Following Colorectal Operations.

    Science.gov (United States)

    Moghadamyeghaneh, Zhobin; Hanna, Mark H; Carmichael, Joseph C; Mills, Steven; Pigazzi, Alessio; Nguyen, Ninh T; Stamos, Michael J

    2015-12-01

    Postoperative wound disruption is associated with high morbidity and mortality. We sought to identify the risk factors and outcomes of wound disruption following colorectal resection. The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was used to examine the clinical data of patients who underwent colorectal resection from 2005 to 2013. Multivariate regression analysis was performed to identify risk factors of wound disruption. We sampled a total of 164,297 patients who underwent colorectal resection. Of these, 2073 (1.3 %) had wound disruption. Patients with wound disruption had significantly higher mortality (5.1 vs. 1.9 %, AOR: 1.46, P = 0.01). The highest risk of wound disruption was seen in patients with wound infection (4.8 vs. 0.9 %, AOR: 4.11, P disruption such as chronic steroid use (AOR: 1.71, P disruption compared to open surgery (AOR: 0.61, P disruption occurs in 1.3 % of colorectal resections, and it correlates with mortality of patients. Wound infection is the strongest predictor of wound disruption. Chronic steroid use, obesity, severe COPD, prolonged operation, non-elective admission, and serum albumin level are strongly associated with wound disruption. Utilization of the laparoscopic approach may decrease the risk of wound disruption when possible.

  9. Loss of Selenium-Binding Protein 1 Decreases Sensitivity to Clastogens and Intracellular Selenium Content in HeLa Cells.

    Science.gov (United States)

    Zhao, Changhui; Zeng, Huawei; Wu, Ryan T Y; Cheng, Wen-Hsing

    2016-01-01

    Selenium-binding protein 1 (SBP1) is not a selenoprotein but structurally binds selenium. Loss of SBP1 during carcinogenesis usually predicts poor prognosis. Because genome instability is a hallmark of cancer, we hypothesize that SBP1 sequesters cellular selenium and sensitizes cancer cells to DNA-damaging agents. To test this hypothesis, we knocked down SBP1 expression in HeLa cervical cancer cells by employing a short hairpin RNA (shRNA) approach. Reduced sensitivity to hydrogen peroxide, paraquat and camptothecin, reactive oxygen species content, and intracellular retention of selenium after selenomethionine treatment were observed in SBP1 shRNA HeLa cells. Results from Western analyses showed that treatment of HeLa cells with selenomethionine resulted in increased SBP1 protein expression in a dose-dependent manner. Knockdown of SBP1 rendered HeLa cells increased expression of glutathione peroxidase-1 but not glutathione peroxidase-4 protein levels and accelerated migration from a wound. Altogether, SBP1 retains supplemental selenium and sensitizes HeLa cancer cells to clastogens, suggesting a new cancer treatment strategy by sequestering selenium through SBP1.

  10. Volatile organo-selenium speciation in biological matter by solid phase microextraction-moderate temperature multicapillary gas chromatography with microwave induced plasma atomic emission spectrometry detection

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, C.; Sanz Landaluze, J.; Ximenez-Embun, P.; Madrid-Albarran, Y.; Camara, C

    2004-01-16

    Microwave induced plasma atomic emission spectrometry (MIP-AES) in combination with multicapillary (MC) gas chromatography could be proven to be useful for element specific detection of volatile species. Solid phase microextraction (SPME) was used for preconcentration and sample-matrix separation. The fiber desorption unit as well as the heating control for the MC column were in-house developed and multicapillary column was operated at moderate temperatures (30-100 deg. C). The method was optimized for organo-selenium species (dimethylselenide (DMSe), diethylselenide (DEtSe) and dimethyldiselenide (DMDSe)), using a chemometric approach. Stationary phases for the separation column were optimized using a conventional GC and contrasted with the results obtained with the MC. Application was focussed on selenium accumulating biological matter, such as lupine, yeast, Indian mustard and garlic. These samples were grown in hydroponic solution containing inorganic selenium (Na{sub 2}SeO{sub 3} and Na{sub 2}SeO{sub 4}). SPME sampling was carried out in fixed volume flow boxes in headspace above the living plants and in vials using treated samples. Results demonstrate inorganic selenium transformation into volatile organic species during metabolism. Separation is fast, a chromatogram can be obtained in less than 3 min and detection limits were at sub-ppb level for all investigated species. The system is independent from the use of a conventional gas chromatographic oven and can be used as a versatile alternative to highly cost intensive methods such as GC-ICP-MS.

  11. SELENIUM TREATMENT/REMOVAL ALTERNATIVES DEMONSTRATION PROJECT - MINE WASTE TECHNOLOGY PROGRAM ACTIVITY III, PROJECT 20

    Science.gov (United States)

    This document is the final report for EPA's Mine WAste Technology Program (MWTP) Activity III, Project 20--Selenium Treatment/Removal Alternatives Demonstration project. Selenium contamination originates from many sources including mining operations, mineral processing, abandoned...

  12. Influence the oxidant action of selenium in radiosensitivity induction and cell death in yeast Saccharomyces cerevisiae; Influencia da acao oxidante do selenio na inducao da radiossensibilidade e morte celular na levedura Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Barbara Abranches de Araujo

    2012-07-01

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

  13. In vitro evidence for endocrine-disrupting chemical (EDC)'s ...

    African Journals Online (AJOL)

    docrine-disrupting chemical (EDC)'s inhibition of drug metabolism. Materials .... serotonin (5-HT) and 4-methylumbelliferone (4-MU) as the probe substrates ... Hu CM, et al. Structure-. 16. inhibition relationship of ginsenosides towards UDP-.

  14. Treating chronic arsenic toxicity with high selenium lentil diets

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-01

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

  15. Treating chronic arsenic toxicity with high selenium lentil diets

    International Nuclear Information System (INIS)

    Sah, Shweta; Vandenberg, Albert; Smits, Judit

    2013-01-01

    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

  16. Selenium and the thyroid: A close-knit connection

    Directory of Open Access Journals (Sweden)

    Ashok K Bhuyan

    2012-01-01

    Full Text Available Introduction: In areas with severe selenium deficiency higher incidence of thyroiditis has been reported due to a decreased activity of selenium-dependent glutathione peroxidase enzyme within thyroid cells. Aims and Objective: To study the effect of selenium supplementation in patients with autoimmune thyroid disease. Materials and Methods: This is a blinded placebo-controlled prospective study done in 60 patients with autoimmune thyroid disease (as defined by an anti-thyroid peroxidase antibody (TPOAb level more than 150 IU/ml irrespective of the baseline thyroid status. Patients with overt hyperthyroidism who are on antithyroid drugs, patients on any other medication, which may alter the immunity status of the patients, and pregnant patients were excluded from the study. Patients were randomized into two age and TPOAb-matched groups; 30 patients received 200 μg of sodium selenite/day, orally, for 3 months, and 30 patients received placebo. All hypothyroid patients were given l-thyroxine replacement. Results: Of 30 patients in the selenium treated group, 6 patients were overtly hypothyroid, 15 were subclinical hypothyroid, 6 were euthyroid, and 3 were subclinical hyperthyroid. The mean TPOAb concentration decreased significantly by 49.5% (P < 0.013 in the selenium treated group versus 10.1% (P < 0.95 in the placebo-treated group. Conclusion: Selenium substitution has a significant impact on inflammatory activity in thyroid-specific autoimmune disease. It would be of interest to determine whether early treatment with selenium in patients with newly developed autoimmune thyroiditis may delay or even prevent the natural course of these diseases.

  17. Disruptive Space Technology

    OpenAIRE

    Benson, Jim

    2004-01-01

    In 1997 "The Innovator’s Dilemma" by Clayton M. Christensen became a popular book in the small satellite and launch vehicle communities. But like the weather, every one talks about “Disruptive Technology” but few do anything about it. In the ‘70s and ‘80s, people were looking for “Paradigm Shifts,” and since the resurrection of Donald Rumsfeld, a recent watchword has been “Transformational Technology.” But today’s buzzword is now “Responsive Space Systems.”

  18. Disruption - Access cards service

    CERN Multimedia

    2014-01-01

    We would like to inform you that between 10 November and 15 December 2014, the access cards service in Building 55 will be disrupted, as the GS Department has decided to improve the facilities for users of this building. During the work, you will find the registration, biometric registration and dosimeter exchange services on the second floor of Building 55 and the vehicle sticker service on the ground floor along with the access cards service. We thank you for your understanding and apologise for any inconvenience caused.

  19. Neutron activation analysis applied to the determination of selenium in bovine plasma

    International Nuclear Information System (INIS)

    Hevia, Sonia E.; Resnizky, Sara M.; Gil, Susana B.; Pawlak, Eva

    1999-01-01

    The procedure used to determine selenium in bovine plasma by neutron irradiation of the samples, followed by a radiochemical separation, is described. This procedure allows the direct determination of the value of the selenium plasmatic level, instead of the indirect conventional method that determines the blood glutathion peroxidase enzyme, as an indicator of the selenium content in the blood. (author)

  20. Speciation of Selenium in Stream Insects Using X-Ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Andrahennadi, R.; Wayland, M.; Pickering, I.J.

    2009-05-28

    Selenium contamination in the environment is a widespread problem affecting insects and other wildlife. Insects occupy a critical middle link and aid in trophic transfer of selenium in many terrestrial and freshwater food chains, but the mechanisms of selenium uptake through the food chain are poorly understood. In particular, biotransformation of selenium by insects into different chemical forms will greatly influence how toxic or benign the selenium is to that organism or to its predators. We have used X-ray absorption spectroscopy (XAS) to identify the chemical form of selenium in insects inhabiting selenium contaminated streams near Hinton, Alberta (Canada). Selenium K near-edge spectra indicate a variability of selenium speciation among the insects that included mayflies (Ephemeroptera), stoneflies (Plecoptera), caddisflies (Trichoptera), and craneflies (Diptera). Higher percentages of inorganic selenium were observed in primary consumers, detritivores, and filter feeders than in predatory insects. Among the organic forms of selenium, organic selenides constituted a major fraction in most organisms. A species modeled as trimethylselenonium was observed during the pupal stage of caddisflies. These results provide insights into how the insects cope with their toxic cargo, including how the selenium is biotransformed into less toxic forms and how it can be eliminated from the insects. More broadly, this study demonstrates the strengths of XAS to probe the effects of heavy elements at trace levels in insects from the field.

  1. Speciation of selenium in stream insects using X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ruwandi Andrahennadi; Mark Wayland; Ingrid J. Pickering [University of Saskatchewan, Saskatoon, SK (Canada). Department of Geological Sciences

    2007-11-15

    Selenium contamination in the environment is a widespread problem affecting insects and other wildlife. Insects occupy a critical middle link and aid in trophic transfer of selenium in many terrestrial and freshwater food chains, but the mechanisms of selenium uptake through the food chain are poorly understood. In particular, biotransformation of selenium by insects into different chemical forms will greatly influence how toxic or benign the selenium is to that organism or to its predators. We have used X-ray absorption spectroscopy (XAS) to identify the chemical form of selenium in insects inhabiting selenium contaminated streams near Hinton, Alberta (Canada). Selenium K near-edge spectra indicate a variability of selenium speciation among the insects that included mayflies (Ephemeroptera), stoneflies (Plecoptera), caddisflies (Trichoptera), and craneflies (Diptera). Higher percentages of inorganic selenium were observed in primary consumers, detritivores, and filter feeders than in predatory insects. Among the organic forms of selenium, organic selenides constituted a major fraction in most organisms. A species modeled as trimethylselenonium was observed during the pupal stage of caddisflies. These results provide insights into how the insects cope with their toxic cargo, including how the selenium is biotransformed into less toxic forms and how it can be eliminated from the insects. More broadly, this study demonstrates the strengths of XAS to probe the effects of heavy elements at trace levels in insects from the field.

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  3. Marginal selenium deficiency down-regulates inflammation-related genes in splenic leukocytes of the mouse

    NARCIS (Netherlands)

    Kipp, A.P.; Banning, A.; Schothorst, van E.M.; Meplan, C.; Coort, S.L.; Evelo, C.; Keijer, J.; Hesketh, J.; Brigelius, R.

    2012-01-01

    Moderate selenium deficiency may lead to an impaired capacity to cope with health challenges. Functional effects of suboptimal selenium intake are not fully known, and biomarkers for an insufficient selenium supply are inadequate. We therefore fed mice diets of moderately deficient or adequate

  4. Selenium-Doped Hydroxyapatite Nanocrystals–Synthesis, Physicochemical Properties and Biological Significance

    Directory of Open Access Journals (Sweden)

    Kamil Pajor

    2018-04-01

    Full Text Available Hydroxyapatites (HAs, as materials with a similar structure to bone minerals, play a key role in biomaterials engineering. They have been applied as bone substitute materials and as coatings for metallic implants, which facilitates their osseointegration. One of the beneficial characteristics of HA, when used to create biocompatible materials with improved physicochemical or biological properties, is its capacity for ionic substitution. The aim of the study was to present the current state of knowledge about HAs containing selenate ions IV or VI. The enrichment of HAs with selenium aims to create a material with advantageous effects on bone tissue metabolism, as well as having anticancer and antibacterial activity. The work is devoted to both methods of obtaining Se-HA and an evaluation of its chemical structure and physicochemical properties. In addition, the biological activity of such materials in vitro and in vivo is discussed.

  5. Selenium deficiency-induced alterations in ion profiles in chicken muscle.

    Directory of Open Access Journals (Sweden)

    Haidong Yao

    Full Text Available Ion homeostasis plays important roles in development of metabolic diseases. In the present study, we examined the contents and distributions of 25 ions in chicken muscles following treatment with selenium (Se deficiency for 25 days. The results revealed that in chicken muscles, the top ranked microelements were silicon (Si, iron (Fe, zinc (Zn, aluminum (Al, copper (Cu and boron (B, showing low contents that varied from 292.89 ppb to 100.27 ppm. After Se deficiency treatment, essential microelements [Cu, chromium (Cr, vanadium (V and manganese (Mn], and toxic microelements [cadmium (Cd and mercury (Hg] became more concentrated (P < 0.05. Elements distribution images showed generalized accumulation of barium (Ba, cobalt (Co, Cu, Fe and V, while Cr, Mn, and Zn showed pin point accumulations in muscle sections. Thus, the ion profiles were generally influenced by Se deficiency, which suggested a possible role of Se deficiency in muscle dysfunctions caused by these altered ion profiles.

  6. Selenium-Mediated Dehalogenation of Halogenated Nucleosides and its Relevance to the DNA Repair Pathway.

    Science.gov (United States)

    Mondal, Santanu; Manna, Debasish; Mugesh, Govindasamy

    2015-08-03

    Halogenated nucleosides can be incorporated into the newly synthesized DNA of replicating cells and therefore are commonly used in the detection of proliferating cells in living tissues. Dehalogenation of these modified nucleosides is one of the key pathways involved in DNA repair mediated by the uracil-DNA glycosylase. Herein, we report the first example of a selenium-mediated dehalogenation of halogenated nucleosides. We also show that the mechanism for the debromination is remarkably different from that of deiodination and that the presence of a ribose or deoxyribose moiety in the nucleosides facilitates the deiodination. The results described herein should help in understanding the metabolism of halogenated nucleosides in DNA and RNA. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Evaluation of iron and selenium losses in metalloproteins separated by gel electrophoresis by ICPMS

    International Nuclear Information System (INIS)

    Gherghel, I.; Fernandez, M.L.; Fernandez, B.; Pereiro, R.; Sanz-Medel, A.

    2009-01-01

    Full text: Metallomics addresses the study of metabolism, transport, and metal-protein interactions aiming to obtain relevant information of physiological and pathological alterations in living organisms. Gel electrophoresis is widely employed in proteomics and its use is actually extending to metallomics. Unfortunately, analysis of proteins by molecular techniques does not offer quantitative information. So, a good alternative could be their determination via the quantification of (semi)metal bound to the protein by ICPMS. In this work, we will show a detailed study of possible losses of protein and/or metal in Fe-bound and selenium proteins (transferrin and glutathione peroxidase, respectively) to evaluate the behaviour of the protein-metal interactions during the electrophoresis process. (author)

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

    Science.gov (United States)

    Wang, Qi

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

  9. Disruptions in the TFTR tokamak

    International Nuclear Information System (INIS)

    Janos, A.; Fredrickson, E.D.; McGuire, K.; Batha, S.H.; Bell, M.G.; Bitter, M.; Budny, R.; Bush, C.E.; Efthimion, P.C.; Hawryluk, R.J.; Hill, K.W.; Hosea, J.; Jobes, F.C.; Johnson, D.W.; Levinton, F.; Mansfield, D.; Meade, D.; Medley, S.S.; Monticello, D.; Mueller, D.; Nagayama, Y.; Owens, D.K.; Park, H.; Park, W.; Post, D.E.; Schivell, J.; Strachan, J.D.; Taylor, G.; Ulrickson, M.; Goeler, S. von; Wilfrid, E.; Wong, K.L.; Yamada, M.; Young, K.M.; Zarnstorff, M.C.; Zweben, S.J.; Drake, J.F.; Kleva, R.G.; Fleischmann, H.H.

    1993-03-01

    For a successful reactor, it will be useful to predict the occurrence of disruptions and to understand disruption effects including how a plasma disrupts onto the wall and how reproducibly it does so. Studies of disruptions on TFTR at both high-β pol and high-density have shown that, in both types, a fast growing m/n=1/1 mode plays an important role. In highdensity disruptions, a newly observed fast m/n = 1/1 mode occurs early in the thermal decay phase. For the first time in TFTR q-profile measurements just prior to disruptions have been made. Experimental studies of heat deposition patterns on the first wall of TFTR due to disruptions have provided information on MHD phenomena prior to or during the disruption, how the energy is released to the wall, and the reproducibility of the heat loads from disruptions. This information is important in the design of future devices such as ITER. Several new processes of runaway electron generation are theoretically suggested and their application to TFTR and ITER is considered, together with a preliminary assessment of x-ray data from runaways generated during disruptions

  10. Activation analysis of selenium in odorous vegetable foods

    International Nuclear Information System (INIS)

    Suzuki, Shogo; Hirai, Shoji; Noda, Katsuhiko.

    1981-01-01

    The selenium in odorous vegetables was analyzed by nondestructive neutron activation analysis using 75 Se, by the γ-ray coincidence method with a Ge(Li) and a NaI(Tl) detectors of definite energy ranges. By means of the coincidence counting, the background spectrum in 75 Se in the vicinity of 265 KeV was able to be reduced to about 1/20 of that by the former detector alone, so that the 75 Se detection sensitivity was raised over fourfold. Thus the selenium in odorous vegetables was able to be determined down to the content as low as 0.02 μg/g. The selenium content in garlic bulbs was 0.02 - 0.31 μg/g, and in onion bulbs 0.02 - 0.05 μg/g, both of which agreed well with those by fluorometry. In other odorous vegetables, the selenium content was as little as 0.1 μg/g or lower. It has been said that the selenium content is relatively large along with sulfur because of the same group, but it was found to be fairly small in the odorous vegetables. (Mori, K.)

  11. AN ANALYTICAL METHOD FOR CHEMICAL SPECIATION OF SELENIUM IN SOIL

    Directory of Open Access Journals (Sweden)

    Constantin Luca

    2010-10-01

    Full Text Available Selenium is an essential microelement, sometimes redoubtable, through its beneficial role - risk depending on its concentration in the food chain, at low dose is an important nutrient in the life of humans and animals, contrary at high doses, it becomes toxic. Selenium may be find itself in the environment (soil, sediment, water in many forms (oxidized, reduced, organometallic which determine their mobility and toxicity. Determination of chemical speciation (identification of different chemical forms provides much more complete information for a better understanding of the behavior and the potential impact on the environment. In this work we present the results of methodological research on the extraction of sequential forms of selenium in the soil and the coupling of analytical methods capable of identifying very small amounts of selenium in soils An efficient scheme of sequential extractions forms of selenium (SES consisting in atomic absorption spectrometry coupled with hydride generation (HGAAS has been developed into five experimental steps, detailed in the paper. This operational scheme has been applied to the analysis of chemical speciation in the following areas: the Bărăgan Plain and Central Dobrogea of Romania.

  12. [Plasma selenium and peripartum cardiomyopathy in Bamako, Mali].

    Science.gov (United States)

    Cénac, A; Touré, K; Diarra, M B; Sergeant, C; Jobic, Y; Sanogo, K; Dembele, M; Fayol, V; Simonoff, M

    2004-01-01

    Peripartum heart failure due to unexplained dilated cardiomyopathy is a common disorder as Savannak-Sahelian Africa. One of the many suspected risk factors identified is selenium deficiency. The purpose of this study was to measure plasma selenium levels in patients with peripartum heart failure due to cardiomyopathy in Bamako, Republic of Mali and compare data with healthy Sahalian women with the same obstetrical status. Plasma selenium was measured in a patient group consisting of 28 Malian women presenting peripartum heart failure and in a control group of 28 healthy breast-feeding Nigerien women of comparable age. The criteria for matching the two groups was parity (similar number of deliveries) since multiparity is a risk factor for peripartum cardiomyopathy. The Wilcoxon test (nonparametric) was used to compare the 2 groups considering up value < 0.05 as significant. Plasma selenium was significantly lower in patients from Mali than in controls from Niger (65 +/- 17 ng/ml vs. 78 +/- 17 ng/ml, p = 0.01). The results of this study showing lower plasma selenium in Bamako patients with peripartum cardiomyopathy than in a matching healthy control population confirms the previous data from the Niamey study.

  13. Mechanisms of Selenium Enrichment and Measurement in Brassicaceous Vegetables, and Their Application to Human Health

    Directory of Open Access Journals (Sweden)

    Melanie Wiesner-Reinhold

    2017-08-01

    Full Text Available Selenium (Se is an essential micronutrient for human health. Se deficiency affects hundreds of millions of people worldwide, particularly in developing countries, and there is increasing awareness that suboptimal supply of Se can also negatively affect human health. Selenium enters the diet primarily through the ingestion of plant and animal products. Although, plants are not dependent on Se they take it up from the soil through the sulphur (S uptake and assimilation pathways. Therefore, geographic differences in the availability of soil Se and agricultural practices have a profound influence on the Se content of many foods, and there are increasing efforts to biofortify crop plants with Se. Plants from the Brassicales are of particular interest as they accumulate and synthesize Se into forms with additional health benefits, such as methylselenocysteine (MeSeCys. The Brassicaceae are also well-known to produce the glucosinolates; S-containing compounds with demonstrated human health value. Furthermore, the recent discovery of the selenoglucosinolates in the Brassicaceae raises questions regarding their potential bioefficacy. In this review we focus on Se uptake and metabolism in the Brassicaceae in the context of human health, particularly cancer prevention and immunity. We investigate the close relationship between Se and S metabolism in this plant family, with particular emphasis on the selenoglucosinolates, and consider the methodologies available for identifying and quantifying further novel Se-containing compounds in plants. Finally, we summarize the research of multiple groups investigating biofortification of the Brassicaceae and discuss which approaches might be most successful for supplying Se deficient populations in the future.

  14. Optimization of wet digestion procedure of blood and tissue for selenium determination by means of 75Se tracer

    International Nuclear Information System (INIS)

    Holynska, B.; Lipinska, K.

    1977-01-01

    Selenium-75 tracer has been used for optimization of analytical procedure of selenium determination in blood and tissue. Wet digestion procedure and reduction of selenium to its elemental form with tellurium as coprecipitant have been tested. Recovery of selenium obtained with the use of optimized analytical procedure amounts up 95% and precision is equal to 4.2%. (author)

  15. Cell disruption for microalgae biorefineries.

    Science.gov (United States)

    Günerken, E; D'Hondt, E; Eppink, M H M; Garcia-Gonzalez, L; Elst, K; Wijffels, R H

    2015-01-01

    Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of products with higher value. Downstream processes in microalgae biorefineries consist of different steps whereof cell disruption is the most crucial part. To maintain the functionality of algae biochemicals during cell disruption while obtaining high disruption yields is an important challenge. Despite this need, studies on mild disruption of microalgae cells are limited. This review article focuses on the evaluation of conventional and emerging cell disruption technologies, and a comparison thereof with respect to their potential for the future microalgae biorefineries. The discussed techniques are bead milling, high pressure homogenization, high speed homogenization, ultrasonication, microwave treatment, pulsed electric field treatment, non-mechanical cell disruption and some emerging technologies. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Disruptions in DIII-D

    International Nuclear Information System (INIS)

    Reiman, A.; Taylor, P.; Kellman, A.; LaHaye, R.

    1996-01-01

    We report on the results of a statistical analysis of the DIII-D disruption data base, and on an examination of a selected subset of the shots to determine the likely causes of disruptions. The statistical analysis focuses on the dependence of the disruption rate on key dimensionless parameters. We find that the disruption frequency is high at modest values of the parameters, and that it can be relatively low at operational limits. For example, the disruption frequency in an ITER relevant regime (β N /l i ∼ 2, 3 G > 0.6, where n G is the Greenwald limit) is approximately 23%. For this range of q, the disruption frequency rises only modestly to about 35% at the β limit, consistent with previous observations of a soft β limit for this q regime. For the range 6 95 G G < .9) in all q regimes we have studied. The location of the minimum moves to higher density with increasing q

  17. Plant selenium hyperaccumulation- Ecological effects and potential implications for selenium cycling and community structure.

    Science.gov (United States)

    Reynolds, R Jason B; Pilon-Smits, Elizabeth A H

    2018-04-25

    Selenium (Se) hyperaccumulation occurs in ~50 plant taxa native to seleniferous soils in Western USA. Hyperaccumulator tissue Se levels, 1000-15,000 mg/kg dry weight, are typically 100 times higher than surrounding vegetation. Relative to other species, hyperaccumulators also transform Se more into organic forms. We review abiotic and biotic factors influencing soil Se distribution and bioavailability, soil being the source of the Se in hyperaccumulators. Next, we summarize the fate of Se in plants, particularly hyperaccumulators. We then extensively review the impact of plant Se accumulation on ecological interactions. Finally, we discuss the potential impact of Se hyperaccumulators on local community composition and Se cycling. Selenium (hyper)accumulation offers ecological advantages: protection from herbivores and pathogens and competitive advantage over other plants. The extreme Se levels in and around hyperaccumulators create a toxic environment for Se-sensitive ecological partners, while offering a niche for Se-resistant partners. Through these dual effects, hyperaccumulators may influence species composition in their local environment, as well as Se cycling. The implied effects of Se hyperaccumulation on community assembly and local Se cycling warrant further investigations into the contribution of hyperaccumulators and general terrestrial vegetation to global Se cycling and may serve as a case study for how trace elements influence ecological processes. Furthermore, understanding ecological implications of plant Se accumulation are vital for safe implementation of biofortification and phytoremediation, technologies increasingly implemented to battle Se deficiency and toxicity. Copyright © 2018. Published by Elsevier B.V.

  18. Overview of core disruptive accidents

    International Nuclear Information System (INIS)

    Marchaterre, J.F.

    1977-01-01

    An overview of the analysis of core-disruptive accidents is given. These analyses are for the purpose of understanding and predicting fast reactor behavior in severe low probability accident conditions, to establish the consequences of such conditions and to provide a basis for evaluating consequence limiting design features. The methods are used to analyze core-disruptive accidents from initiating event to complete core disruption, the effects of the accident on reactor structures and the resulting radiological consequences are described

  19. Disrupted Refugee Family Life

    DEFF Research Database (Denmark)

    Shapiro, Ditte Krogh

    2017-01-01

    Fleeing civil war involves managing life threatening events and multiple disruptions of everyday life. The theoretical potentials of analysing the recreation of everyday family life among Syrian refugees in Denmark is explored based on conceptualizations that emphasize the collective agency...... of family members in social historical contexts. Studying the multiple perspectives of family members shows how social support conceptualized as care practises is conflictual in the changing everyday family practices that are transformed by policy. The purpose of studying how families manage to flee civil...... war and struggle to recreate an everyday life in exile is to contribute with contextualization and expansion of mainstream understandings of family life, suffering, and resilience in refugee family trajectories in multiple contexts....

  20. Selenium status, thyroid volume, and multiple nodule formation in an area with mild iodine deficiency

    DEFF Research Database (Denmark)

    Rasmussen, Lone Banke; Schomburg, Lutz; Kohrle, Josef

    2011-01-01

    ) introduction of iodine fortification. Serum selenium concentration and urinary iodine were measured, and the thyroid gland was examined by ultrasonography in the same subjects. Associations between serum selenium concentration and thyroid parameters were examined in multiple linear regression models...... or logistic regression models.Results: Serum selenium concentration was found to be significantly, negatively associated with thyroid volume (P=0.006), and a low selenium status significantly increased the risk for thyroid enlargement (P=0.007). Furthermore, low serum selenium status had a tendency...

  1. Selenium status and cancer mortality in subjects residing in four Canadian provinces

    International Nuclear Information System (INIS)

    Morris, J.S.; Horsman, T.L.; Spate, V.L.; Baskett, C.K.; Mason, M.M.; Nichols, T.A.; Rohan, T.; Soskolne, C.L.; Jain, M.

    2001-01-01

    Selenium status in male and female Canadian subjects was measured relative to cancer mortality in their respective provinces. Toenail specimens from 755 subjects, 377 males and 378 females, living in Vancouver (186), Edmonton (188), Toronto (197) and Montreal (184) were analyzed by instrumental neutron activation analysis giving means of 0.968 ± 0.177, 0.950 ± 0.148, 0.932 ± 0.135 and 0.896 ± 0.127 ppm Se, respectively. The effect of selenium determinants such as gender, selenium supplementation and smoking on selenium status is presented. Details of the observed inverse relationship of selenium status and cancer mortality are discussed. (author)

  2. The Effect of Red Pepper Waste Added to Compost on Selenium Content of Pleurotus citrinopileatus Singer

    Directory of Open Access Journals (Sweden)

    Fatih Kalyoncu

    2016-03-01

    Full Text Available In this study, selenium levels of P.citrinopileatus added different rates of red pepper waste to compost as a source of selenium were determined. For this purpose, six different compost groups were prepared and inoculated with P.citrinopileatus mycelia. Selenium levels of harvested mushrooms were analysed. In conclusion, 0.338 µg/g selenium were determined in one gram dry mushroom that red pepper waste added to compost at 5%. Mycelia growth and selenium accumulation were negatively affected by higher rates of red pepper waste.

  3. Total selenium in irrigation drain inflows to the Salton Sea, California, April 2009

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2009-01-01

    This report presents the results for the final sampling period (April 2009) of a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium and total suspended solids were determined in water samples. Total selenium, percent total organic carbon, and particle size were determined in sediments. Mean total selenium concentrations in water ranged from 0.98 to 22.9 micrograms per liter. Total selenium concentrations in sediment ranged from 0.078 to 5.0 micrograms per gram dry weight.

  4. Distribution of Iodine and Selenium in Selected Food Commodities

    Directory of Open Access Journals (Sweden)

    Strapáč I.

    2016-03-01

    Full Text Available The aim of this study was to investigate the distribution of the contents of iodine and selenium in selected food commodities. Fresh food commodities were mineralized and analysed for their iodine and selenium content by Inductively Coupled Plasma-Mass Spectrometry using the calibration curve as the method for determining the contents of the elements. The average fruit and vegetables concentrations of iodine were very low. The cow’s milk, other dairy products, eggs, poultry, fresh water fish, beef, liver, and mushrooms are frequently regarded as the most important natural source of dietary iodine from common foods. The higher concentrations of selenium were recorded in the kidney, liver, pork, beef, poultry, fresh water fish, hen’s eggs, cow’s milk, other dairy products, wheat flour, fats, coffee, peppers, mushrooms and potatoes.

  5. Structure of amorphous selenium studied by neutron diffraction

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Knudsen, Torben Steen; Carneiro, K.

    1975-01-01

    Neutron diffraction measurements on amorphous selenium have been performed at 293 and 80 K. Careful analyses of the instrumental corrections were made to avoid systematic errors in the measured structure factor S (kappa) in the wave vector region 0 ? kappa ? 12 Å−1. As a result of the data...... treatment, the neutron scattering cross sections of selenium are determined to be sigmacoh = 8.4±0.1 b and sigmainc = 0.1±0.1 b. Using the fact that S (kappa) for large kappa's is determined by the short distances in the sample, a new method for extrapolation of the experimental S (kappa) until convergence....... Finally, we give a brief discussion of the different models for the structure of amorphous selenium, taking both diffraction measurements and thermodynamic considerations into account. The Journal of Chemical Physics is copyrighted by The American Institute of Physics....

  6. Deposition of selenium coatings on beryllium foils. Revision 1

    International Nuclear Information System (INIS)

    Erikson, E.D.; Tassano, P.L.; Reiss, R.H.; Griggs, G.E.

    1984-01-01

    A technique for preparing selenium films on 50.8 micrometers thick beryllium foils is described. The selenium was deposited in vacuum from a resistance heated evaporation source. A water-cooled enclosure was used to minimize contamination of the vacuum system and to reduce the exposure of personnel to toxic and obnoxious materials. Profilometry measurements of the coatings indicated selenium thicknesses of 5.5, 12.9, 37.5, 49.8 and 74.5 micrometers. The control of deposition rate and of coating thickness was facilitated using a commercially available closed-loop programmable deposition controller. The x-ray transmission of the coated substrates was measured using a tritiated zirconium source. The transmissivities of the film/substrate combination are presented for the range of energies from 4 to 20 keV

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

    DEFF Research Database (Denmark)

    Outzen, Malene; Tjønneland, Anne; Larsen, Erik Huusfeldt

    2015-01-01

    Selenium status of the Danish population is below that assumed optimal for the suggested protective effects against chronic diseases, including certain cancers. Fish and shellfish are important dietary sources of selenium in Denmark. We investigated the effect of increased fish and mussel intake...... on selenium blood concentrations in a population with relatively low habitual dietary selenium intake. We randomly assigned 102 healthy men and women (all non-smokers) aged 48-76 years to an intervention group (n = 51) or a control group (n = 51). Intervention participants received 1000 g fish and mussels....../week for 26 weeks (similar to 50 mu g 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...

  8. Disruptive Technology: An Uncertain Future

    Science.gov (United States)

    2005-05-21

    Technology that overturns market -- Military - Technology that causes a fundamental change in force structure, basing, and capability balance * Disruptive Technologies may arise from systems or enabling technology.

  9. Major disruption process in tokamak

    International Nuclear Information System (INIS)

    Kurita, Gen-ichi; Azumi, Masafumi; Tuda, Takashi; Takizuka, Tomonori; Tsunematsu, Toshihide; Tokuda, Shinji; Itoh, Kimitaka; Takeda, Tatsuoki

    1981-11-01

    The major disruption in a cylindrical tokamak is investigated by using the multi-helicity code, and the destabilization of the 3/2 mode by the mode coupling with the 2/1 mode is confirmed. The evolution of the magnetic field topology caused by the major disruption is studied in detail. The effect of the internal disruption on the 2/1 magnetic island width is also studied. The 2/1 magnetic island is not enhanced by the flattening of the q-profile due to the internal disruption. (author)

  10. Short- and long-term health consequences of sleep disruption

    Directory of Open Access Journals (Sweden)

    Medic G

    2017-05-01

    Full Text Available Goran Medic,1,2 Micheline Wille,1 Michiel EH Hemels1 1Market Access, Horizon Pharma B.V., Utrecht, 2Unit of Pharmacoepidemiology & Pharmacoeconomics, Department of Pharmacy, University of Groningen, Groningen, The Netherlands Abstract: Sleep plays a vital role in brain function and systemic physiology across many body systems. Problems with sleep are widely prevalent and include deficits in quantity and quality of sleep; sleep problems that impact the continuity of sleep are collectively referred to as sleep disruptions. Numerous factors contribute to sleep disruption, ranging from lifestyle and environmental factors to sleep disorders and other medical conditions. Sleep disruptions have substantial adverse short- and long-term health consequences. A literature search was conducted to provide a nonsystematic review of these health consequences (this review was designed to be nonsystematic to better focus on the topics of interest due to the myriad parameters affected by sleep. Sleep disruption is associated with increased activity of the sympathetic nervous system and hypothalamic–pituitary–adrenal axis, metabolic effects, changes in circadian rhythms, and proinflammatory responses. In otherwise healthy adults, short-term consequences of sleep disruption include increased stress responsivity, somatic pain, reduced quality of life, emotional distress and mood disorders, and cognitive, memory, and performance deficits. For adolescents, psychosocial health, school performance, and risk-taking behaviors are impacted by sleep disruption. Behavioral problems and cognitive functioning are associated with sleep disruption in children. Long-term consequences of sleep disruption in otherwise healthy individuals include hypertension, dyslipidemia, cardiovascular disease, weight-related issues, metabolic syndrome, type 2 diabetes mellitus, and colorectal cancer. All-cause mortality is also increased in men with sleep disturbances. For those with

  11. Analyses of Selenotranscriptomes and Selenium Concentrations in Response to Dietary Selenium Deficiency and Age Reveal Common and Distinct Patterns by Tissue and Sex in Telomere-Dysfunctional Mice.

    Science.gov (United States)

    Cao, Lei; Zhang, Li; Zeng, Huawei; Wu, Ryan Ty; Wu, Tung-Lung; Cheng, Wen-Hsing

    2017-10-01

    Background: The hierarchies of tissue selenium distribution and selenotranscriptomes are thought to critically affect healthspan and longevity. Objective: We determined selenium status and selenotranscriptomes in response to long-term dietary selenium deficiency and age in tissues of male and female mice. Methods: Weanling telomerase RNA component knockout C57BL/6 mice were fed a selenium-deficient (0.03 mg Se/kg) Torula yeast-based AIN-93G diet or a diet supplemented with sodium selenate (0.15 mg Se/kg) until age 18 or 24 mo. Plasma, hearts, kidneys, livers, and testes were collected to assay for selenotranscriptomes, selected selenoproteins, and tissue selenium concentrations. Data were analyzed with the use of 2-factor ANOVA (diet × age) in both sexes. Results: Dietary selenium deficiency decreased ( P ≤ 0.05) selenium concentrations (65-72%) and glutathione peroxidase (GPX) 3 (82-94%) and selenoprotein P (SELENOP) (17-41%) levels in the plasma of both sexes of mice and mRNA levels (9-68%) of 4, 4, and 12 selenoproteins in the heart, kidney, and liver of males, respectively, and 5, 16, and 14 selenoproteins, respectively, in females. Age increased selenium concentrations and SELENOP levels (27% and 30%, respectively; P ≤ 0.05) in the plasma of males only but decreased (12-46%; P selenium deficiency and age in ≥1 tissue or sex, or both. Dietary selenium deficiency upregulated (40-160%; P ≤ 0.05) iodothyronine deiodinase 2 ( Dio2 ) and selenoprotein N ( Selenon ) in the kidneys of males. Age upregulated (11-44%; P selenium status and selenotranscriptomes because of dietary selenium deficiency and age. © 2017 American Society for Nutrition.

  12. [Is plasma selenium correlated to transthyretin levels in critically ill patients?

    Science.gov (United States)

    Freitas, Renata G B O N; Nogueira, Roberto Jose Negrão; Cozzolino, Silvia Maria Franciscato; Vasques, Ana Carolina Junqueira; Ferreira, Matthew Thomas; Hessel, Gabriel

    2017-06-05

    Selenium is an essential trace element, but critically ill patients using total parenteral nutrition (PN) do not receive selenium because this mineral is not commonly offered. Threfore, the eval uation of plasma selenium levels is very important for treating or preventing this deficiency. Recent studies have shown that transthyretin may reflect the selenium intake and could be considered a biomarker. However, this issue is still little explored in the literature. This study aims to investigate the correlation of transthyretin with the plasma selenium of critically ill patients receiving PN. This was a prospective cohort study with 44 patients using PN without selenium. Blood samples were carried out in 3 stages: initial, 7th and 14th day of PN. In order to evaluate the clinical condition and the inflammatory process, albumin, C-reactive protein (CRP), transthyretin, creatinine and HDL cholesterol levels were observed. To assess the selenium status, plasma selenium and glutathione peroxidase (GPx) in whole blood were measured. Descriptive analyses were performed and the ANOVA, Mann-Whitney and Spearman's coefficient tests were conducted; we assumed a significance level of 5%. A positive correlation of selenium with the GPx levels (r = 0.46; p = 0.03) was identified. During two weeks, there was a positive correlation of transthyretin with plasma selenium (r = 0.71; p = 0.05) regardless of the CRP values. Transthyretin may have reflected plasma selenium, mainly because the correlation was verified after the acute phase.

  13. Hydrodynamic aspects of selenium X-ray laser targets

    Energy Technology Data Exchange (ETDEWEB)

    Charatis, G; Busch, G E; Shepard, C L; Campbell, P M; Rosen, M D

    1986-10-01

    Recent experiments at KMS have been performed to investigate parameter variations of target component thickness, laser pulse duration and intensity, and one-sided vs two-sided irradiation in order to optimize the performance of the Livermore exploding foil selenium x-ray laser experiments. Preliminary experiments with selenium double foil targets were also conducted as a means of prolonging the duration and enlarging the spatial extent of the lasing conditions. Four-frame holographic interferometry was used in determining the time-dependence of density profiles obtained by Abel inversion of the interferometric fringe field and comparisons were made to LASNEX code calculations.

  14. Blood selenium content determination by X-ray fluorescence

    International Nuclear Information System (INIS)

    Mainardi, R.T.

    1987-01-01

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

  15. Muonic X-ray intensities in phosphorus- and selenium modifications

    International Nuclear Information System (INIS)

    Kaeser, K.; Robert-Tissot, B.; Schaller, L.A.; Schellenberg, L.; Schneuwly, H.

    1979-01-01

    Muonic X-ray intensity measurements have been performed at SIN on allotropic modifications of phosphorus (white, red and black) and of selenium (red and black). Structure effects have been found in the intensity ratios of the K-series between amorphous and crystalline modifications of the same element. The effect in the higher series (Se) is less pronounced. On the other hand, the two crystalline phosphorus modifications (red and black) show the same intensity behavior. The root-mean-square radii 2 >sup(1/2) of phosphorus and (natural) selenium were found to be 3.187(3) fm and 4.138(1) fm respectively. (Auth.)

  16. Theoretical predictions of arsenic and selenium species under atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Monahan-Pendergast, M.T.; Przybylek, M.; Lindblad, M.; Wilcox, J. [Worcester Polytechnic Institute, Worcester, MA (United States). Dept. of Chemical Engineering

    2008-03-15

    Thermochemical properties of arsenic and selenium species thought to be released into the atmosphere during the coal combustion were examined using ab initio methods. At various levels of theory, calculated geometries and vibrational frequencies of the species were compared with experimental data, where available. Through a comparison of equilibrium constants for a series of gaseous arsenic and selenium oxidation reactions involving OH and HO{sub 2}, five thermodynamically favored reactions were found. In addition, it was determined that all favored reactions were more likely to go to completion tinder tropospheric, rather than stratospheric, conditions.

  17. Effect of irradiation on sod activity and selenium content in garlic

    International Nuclear Information System (INIS)

    Xu Weimin; Zheng Anjian; Yan Jianmin; Cao Qingsui; Wu Haihong; Cao Shifeng

    2006-01-01

    The effects of irradiation at 0.1 kGy, 1.0 kGy on SOD activity and the content of total selenium, inorganic selenium, organic selenium in garlic (Allium sativum L.) stored at 10 degree C or 25 degree C were investigated. The results indicated that irradiation treatment with 0.1 kGy, 1 kGy significantly slowed the reduction of SOD activities in garlic stored at 10 degree C or 25 degree C, while the treatment irradiation had no influence on the content of all kinds of selenium. But the garlic stored at 25 degree C had higher content of total selenium, inorganic selenium, organic selenium than that in garlic stored at 10 degree C. (authors)

  18. Influence of dietary sodium selenite on tissue selenium levels of growing pigs

    International Nuclear Information System (INIS)

    Moksnes, K.; Tollersrud, S.; Larsen, H.J.

    1982-01-01

    Twenty Norwegian Landrace pigs were divided into 5 groups and fed a basal diet consisting of a mixture of dried skim milk and whey powder together with ground barley. The diet was supplemented with 0, 0.2, 0.8, 1.2, and 2.2 μg/g selenium as sodium selenite and was fed for 12 weeks. The muscle selenium level was increased by a factor of about 4 and the liver selenium by a factor of about 12 when the dietary selenium supplement was increased from zero to 2.2μg/g. There was a significant linear correlation between dietary selenium and selenium concentrations in tissues. Possible benefit for humans consuming meat from animals having received the selenium doses used in this experiment are discussed. (author)

  19. Serum selenium concentration in maternal and umbilical cord blood. Relation to course and outcome of pregnancy

    DEFF Research Database (Denmark)

    Bro, S; Berendtsen, H; Nørgaard, J

    1988-01-01

    The present knowledge of the role of selenium in human fetal and neonatal development is sparse. In this study we measured serum selenium concentrations in maternal and umbilical cord blood from 500 Danish mothers at delivery, looking for a relationship between various maternal and fetal complica......The present knowledge of the role of selenium in human fetal and neonatal development is sparse. In this study we measured serum selenium concentrations in maternal and umbilical cord blood from 500 Danish mothers at delivery, looking for a relationship between various maternal and fetal...... complications and selenium values. In mothers with uncomplicated pregnancies and deliveries serum selenium concentrations were 0.84 +/- 0.19 mumol/l (mean +/- SD), whereas in cord blood from full-term babies born adequate for gestational age and with no malformations serum selenium concentrations were 0...

  20. Potential reproduction and response of selenium and zinc mineral supplementation on quality of goat samosir semen

    Science.gov (United States)

    Siswoyo, P.; Tafsin, M.; Handarini, R.

    2018-02-01

    The present study was conducted to investigate the effect of suppllementattion of selenium and zinc on semen quality and growth of samosir goat. The experimental design used latin square design (4x4). The treatment supplementation mineral on multi nutrient block (MNB) composed of without sipplementation (p0), +10ppm selenium (p1), +10ppm zinc (p2), +10ppm selenium and +10ppm zinc (p3). The result showed that supplementation mineral selenium and zinc increased significantly (pgoat were supplemented by selenium and zinc influenced motility, viability, volume concentration, and responding hypo osmotic swelling (HOS). Combination supplementation selenium and zinc significanly had higher semen quality than ither treatment. It is concluded that supplementation selenium and zinc improve growth and semen quality of samosir goat.