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Sample records for 85th percentile selenium

  1. Selenium

    MedlinePlus

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

  2. 2014 annual summary of the lower Gunnison River Basin Selenium Management Program water-quality monitoring, Colorado

    USGS Publications Warehouse

    Henneberg, Mark F.

    2016-01-01

    Dissolved-selenium loading analyses of data collected at 18 water-quality sites in the lower Gunnison River Basin in Colorado were completed through water year (WY) 2014. A WY is defined as October 1–September 30. Selenium is a trace element that bioaccumulates in aquatic food chains and can cause reproductive failure, deformities, and other harmful effects. This report presents information on the dissolved-selenium loads at 18 sites in the lower Gunnison River Basin for WYs 2011–2014. Annual dissolved-selenium loads were calculated at 5 sites with continuous U.S. Geological Survey (USGS) streamflow gages, whereas instantaneous dissolved-selenium loads were calculated for the remaining 13 sites using water-quality samples that had been collected periodically during WYs 2011–2014. Annual dissolved-selenium loads for WY 2014 ranged from 336 pounds (lb) at Uncompahgre River at Colona to 13,300 lb at Gunnison River near Grand Junction (Whitewater). Most sites in the basin had a median instantaneous dissolved-selenium load of less than 20.0 lb per day. In general, dissolved-selenium loads at Gunnison River main-stem sites showed an increase from upstream to downstream.The State of Colorado water-quality standard for dissolved selenium of 4.6 micrograms per liter (µg/L) was compared to the 85th percentiles for dissolved selenium at selected water-quality sites. Annual 85th percentiles for dissolved selenium were calculated for the five core USGS sites having streamflow gages using estimated dissolved-selenium concentrations from linear regression models. These annual 85th percentiles in WY 2014 ranged from 0.97 µg/L at Uncompahgre River at Colona to 16.7 µg/L at Uncompahgre River at Delta. Uncompahgre River at Delta and Whitewater were the only core sites where water samples exceeded the State of Colorado water-quality standard for dissolved selenium of 4.6 µg/L.Instantaneous 85th percentiles for dissolved selenium were calculated for sites with sufficient data

  3. SELENIUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. Analysis of Dissolved Selenium Loading for Selected Sites in the Lower Gunnison River Basin, Colorado, 1978-2005

    USGS Publications Warehouse

    Thomas, Judith C.; Leib, Kenneth J.; Mayo, John W.

    2008-01-01

    Elevated selenium concentrations in streams are a water-quality concern in western Colorado. The U.S. Geologic Survey, in cooperation with the Colorado Department of Public Health and Environment, summarized selenium loading in the Lower Gunnison River Basin to support the development of total maximum daily selenium loads at sites that represent the cumulative contribution to U.S. Environmental Protection Agency 303(d) list segments. Analysis of selenium loading included quantifying loads and determining the amount of load that would need to be reduced to bring the site into compliance, referred to as 'the load reduction,' with the State chronic aquatic-life standard for dissolved selenium [85th percentile selenium concentration not to exceed 4.6 ?g/L (micrograms per liter)], referred to as 'the water-quality standard.' Streamflow and selenium concentration data for 54 historical water-quality/water-quantity monitoring sites were compiled from U.S. Geological Survey and Colorado Department of Public Health and Environment data sources. Three methods were used for analysis of selenium concentration data to address the variable data density among sites. Mean annual selenium loads were determined for only 10 of the 54 sites due to data availability limitations. Twenty-two sites had 85th percentile selenium concentrations that exceeded the water-quality standard, 3 sites had 85th percentile selenium concentrations less than the State standard, and 29 sites could not be evaluated with respect to 85th percentile selenium concentration (sample count less than 5). To bring selenium concentrations into compliance with the water-quality standard, more than 80 percent of the mean annual selenium load would need to be reduced at Red Rock Canyon, Dry Cedar Creek, Cedar Creek, Loutzenhizer Arroyo, Sunflower Drain, and Whitewater Creek. More than 50 percent of the mean annual load would need to be reduced at Dry Creek to bring the site into compliance with the water

  5. Tutorial: Calculating Percentile Rank and Percentile Norms Using SPSS

    ERIC Educational Resources Information Center

    Baumgartner, Ted A.

    2009-01-01

    Practitioners can benefit from using norms, but they often have to develop their own percentile rank and percentile norms. This article is a tutorial on how to quickly and easily calculate percentile rank and percentile norms using SPSS, and this information is presented for a data set. Some issues in calculating percentile rank and percentile…

  6. Concentrations and Loads of Selenium in Selected Tributaries to the Colorado River in the Grand Valley, Western Colorado, 2004-2006

    USGS Publications Warehouse

    Leib, Kenneth J.

    2008-01-01

    The reach of the Colorado River from the Gunnison River confluence to the Utah Border, and tributaries in the Grand Valley, are on the State of Colorado 303(d) list of impaired water bodies because the concentrations of dissolved selenium in these streams exceed the State of Colorado chronic standard of 4.6 micrograms per liter at the 85th percentile level. In response to concerns raised by a local watershed initiative about the issue of selenium in the Grand Valley, the U.S. Geological Survey, in cooperation with Mesa County and the City of Grand Junction, developed a study to characterize and determine the sources of selenium and how these sources are related to changes in land use. This report describes the methods and results of a study of concentrations and loads of selenium in three tributaries to the Colorado River in the Grand Valley. The study area consists of three subbasins, Persigo Wash, Adobe Creek, and Lewis Wash, each representing transitional agricultural to residential, agricultural, and residential land-use types, respectively. These subbasins represent different land-use types and the tributaries that drain each subbasin contribute moderate to high concentrations and loads of selenium to the Colorado River. Two synoptic-sampling events were conducted in each tributary to characterize variations in water quality during the nonirrigation season. Water samples were collected for analysis of dissolved selenium, total nitrogen, and total dissolved solids (salinity). Streamflow was measured by either the tracer-dilution or standard current-meter method. In Persigo Wash selenium concentrations generally decreased or remained constant in a downstream direction whereas selenium loads increased. Effluent from the Persigo Wash wastewater treatment plant diluted selenium concentrations in Persigo Wash and increased the selenium load. The concentrations and loads of salinity and total nitrogen generally increased downstream in Persigo Wash. Concentrations and

  7. A Comparison of Three Conditional Growth Percentile Methods: Student Growth Percentiles, Percentile Rank Residuals, and a Matching Method

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Seo, Dong Gi

    2014-01-01

    This article provides a brief overview and comparison of three conditional growth percentile methods; student growth percentiles, percentile rank residuals, and a nonparametric matching method. These approaches seek to describe student growth in terms of the relative percentile ranking of a student in relationship to students that had the same…

  8. National contaminant biomonitoring program: concentrations of arsenic, cadmium, copper, lead, mercury, selenium, and zinc in U.S. Freshwater Fish, 1976–1984

    USGS Publications Warehouse

    Schmitt, Christopher J.; Brumbaugh, William G.

    1990-01-01

    From late 1984 to early 1985, the U.S. Fish and Wildlife Service collected a total of 315 composite samples of whole fish from 109 stations nationwide, which were analyzed for arsenic, cadmium, copper, lead, mercury, selenium, and zinc. Geometric mean, maximum, and 85th percentile concentrations (μg/g wet weight) for 1984 samples were as follows: arsenic-0.14, 1.5, 0.27; cadmium-0.03, 0.22, 0.05; copper-0.65, 23.1, 1.0; mercury-0.10, 0.37, 0.17; lead-0.11, 4.88, 0.22; selenium-0.42, 2.30, 0.73; and zinc-21.7, 118.4, 34.2. The mean concentrations of selenium and lead were significantly lower than in the previous NCBP collection (1980–81). Mean concentrations of arsenic and cadmium also declined significantly between 1976, when elemental contaminants in fish were first measured in the NCBP, and 1984. Of greatest significance, lead concentrations declined steadily from 1976 to 1984, suggesting that regulatory measures have successfully reduced the influx of lead to the aquatic environment.

  9. Selenium Sulfide

    MedlinePlus

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

  10. Waist Circumferences of Chilean Students: Comparison of the CDC-2012 Standard and Proposed Percentile Curves

    PubMed Central

    Gómez-Campos, Rossana; Lee Andruske, Cinthya; Hespanhol, Jefferson; Sulla Torres, Jose; Arruda, Miguel; Luarte-Rocha, Cristian; Cossio-Bolaños, Marco Antonio

    2015-01-01

    The measurement of waist circumference (WC) is considered to be an important means to control overweight and obesity in children and adolescents. The objectives of the study were to (a) compare the WC measurements of Chilean students with the international CDC-2012 standard and other international standards, and (b) propose a specific measurement value for the WC of Chilean students based on age and sex. A total of 3892 students (6 to 18 years old) were assessed. Weight, height, body mass index (BMI), and WC were measured. WC was compared with the CDC-2012 international standard. Percentiles were constructed based on the LMS method. Chilean males had a greater WC during infancy. Subsequently, in late adolescence, males showed values lower than those of the international standards. Chilean females demonstrated values similar to the standards until the age of 12. Subsequently, females showed lower values. The 85th and 95th percentiles were adopted as cutoff points for evaluating overweight and obesity based on age and sex. The WC of Chilean students differs from the CDC-2012 curves. The regional norms proposed are a means to identify children and adolescents with a high risk of suffering from overweight and obesity disorders. PMID:26184250

  11. Waist Circumferences of Chilean Students: Comparison of the CDC-2012 Standard and Proposed Percentile Curves.

    PubMed

    Gómez-Campos, Rossana; Andruske, Cinthya Lee; Hespanhol, Jefferson; Torres, Jose Sulla; Arruda, Miguel; Luarte-Rocha, Cristian; Cossio-Bolaños, Marco Antonio

    2015-07-01

    The measurement of waist circumference (WC) is considered to be an important means to control overweight and obesity in children and adolescents. The objectives of the study were to (a) compare the WC measurements of Chilean students with the international CDC-2012 standard and other international standards, and (b) propose a specific measurement value for the WC of Chilean students based on age and sex. A total of 3892 students (6 to 18 years old) were assessed. Weight, height, body mass index (BMI), and WC were measured. WC was compared with the CDC-2012 international standard. Percentiles were constructed based on the LMS method. Chilean males had a greater WC during infancy. Subsequently, in late adolescence, males showed values lower than those of the international standards. Chilean females demonstrated values similar to the standards until the age of 12. Subsequently, females showed lower values. The 85th and 95th percentiles were adopted as cutoff points for evaluating overweight and obesity based on age and sex. The WC of Chilean students differs from the CDC-2012 curves. The regional norms proposed are a means to identify children and adolescents with a high risk of suffering from overweight and obesity disorders. PMID:26184250

  12. An Activity for Learning to Find Percentiles

    ERIC Educational Resources Information Center

    Cox, Richard G.

    2016-01-01

    This classroom activity is designed to help students practice calculating percentiles. The approach of the activity involves physical sorting and full classroom participation in each calculation. The design encourages a more engaged approach than simply having students make a calculation with numbers on a paper.

  13. Selenium Sulfide

    MedlinePlus

    Selenium sulfide comes in a lotion and is usually applied as a shampoo. As a shampoo, selenium sulfide usually is used twice a week for the first ... it is irritating. Rinse off all of the lotion.Do not use this medication on children younger ...

  14. Selenium sulfide

    Integrated Risk Information System (IRIS)

    Selenium sulfide ; CASRN 7446 - 34 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  15. Nutritional aspects of selenium

    SciTech Connect

    Choe, M.

    1987-01-01

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

  16. Alternative Statistical Frameworks for Student Growth Percentile Estimation

    ERIC Educational Resources Information Center

    Lockwood, J. R.; Castellano, Katherine E.

    2015-01-01

    This article suggests two alternative statistical approaches for estimating student growth percentiles (SGP). The first is to estimate percentile ranks of current test scores conditional on past test scores directly, by modeling the conditional cumulative distribution functions, rather than indirectly through quantile regressions. This would…

  17. The genotoxicity of selenium.

    PubMed

    Shamberger, R J

    1985-07-01

    Selenium at nutritional levels has been shown to have numerous anticarcinogenic or preventative effects against carcinogen-induced breast, colon, liver and skin cancer in animals. Many of these anticarcinogenic effects have been summarized. In addition, numerous mutagenic and antimutagenic effects of selenium compounds have been reported. Some of the selenium compounds frequently tested for mutagenicity are listed in Table 1. Because of the numerous reported anticarcinogenic and preventative effects of selenium, many individuals are supplementing their diets with amounts of selenium that are greater than the recommended daily requirement. Selenium is also used widely in industrial products such as selenium rectifiers, photoelectric batteries, alloys and paints. Because selenium at higher levels is known to be toxic, there should be a greater understanding about its genotoxic as well as its beneficial effect. The object of this review is to summarize experimental evidence both for the antimutagenic and the mutagenic effect of selenium. PMID:3923345

  18. Percentile curves for skinfold thickness for Canadian children and youth

    PubMed Central

    Ashley-Martin, Jillian; Maguire, Bryan; Hamilton, David C.

    2016-01-01

    Background. Skinfold thickness (SFT) measurements are a reliable and feasible method for assessing body fat in children but their use and interpretation is hindered by the scarcity of reference values in representative populations of children. The objective of the present study was to develop age- and sex-specific percentile curves for five SFT measures (biceps, triceps, subscapular, suprailiac, medial calf) in a representative population of Canadian children and youth. Methods. We analyzed data from 3,938 children and adolescents between 6 and 19 years of age who participated in the Canadian Health Measures Survey cycles 1 (2007/2009) and 2 (2009/2011). Standardized procedures were used to measure SFT. Age- and sex-specific centiles for SFT were calculated using the GAMLSS method. Results. Percentile curves were materially different in absolute value and shape for boys and girls. Percentile girls in girls steadily increased with age whereas percentile curves in boys were characterized by a pubertal centered peak. Conclusions. The current study has presented for the first time percentile curves for five SFT measures in a representative sample of Canadian children and youth. PMID:27547554

  19. Percentile curves for skinfold thickness for Canadian children and youth.

    PubMed

    Kuhle, Stefan; Ashley-Martin, Jillian; Maguire, Bryan; Hamilton, David C

    2016-01-01

    Background. Skinfold thickness (SFT) measurements are a reliable and feasible method for assessing body fat in children but their use and interpretation is hindered by the scarcity of reference values in representative populations of children. The objective of the present study was to develop age- and sex-specific percentile curves for five SFT measures (biceps, triceps, subscapular, suprailiac, medial calf) in a representative population of Canadian children and youth. Methods. We analyzed data from 3,938 children and adolescents between 6 and 19 years of age who participated in the Canadian Health Measures Survey cycles 1 (2007/2009) and 2 (2009/2011). Standardized procedures were used to measure SFT. Age- and sex-specific centiles for SFT were calculated using the GAMLSS method. Results. Percentile curves were materially different in absolute value and shape for boys and girls. Percentile girls in girls steadily increased with age whereas percentile curves in boys were characterized by a pubertal centered peak. Conclusions. The current study has presented for the first time percentile curves for five SFT measures in a representative sample of Canadian children and youth. PMID:27547554

  20. Selenium: Element of Contrasts

    ERIC Educational Resources Information Center

    Goldsmith, Robert H.; And Others

    1978-01-01

    Reports on recent findings concerning the impact of selenium on human and animal health. In its various oxidation states, different concentrations of selenium may be helpful or detrimental to human health. (CP)

  1. Selenium: Poison and Preventive.

    ERIC Educational Resources Information Center

    Marmion Howe, Sister

    1978-01-01

    Selenium is an essential nutrient to the human body, but it can reach toxic levels causing a disease called selenosis. This article discusses selenium, its geographical distribution, toxicity, nutritional role, and carcinogenicity. (MA)

  2. Percentile Curves for Anthropometric Measures for Canadian Children and Youth

    PubMed Central

    Kuhle, Stefan; Maguire, Bryan; Ata, Nicole; Hamilton, David

    2015-01-01

    Body mass index (BMI) is commonly used to assess a child's weight status but it does not provide information about the distribution of body fat. Since the disease risks associated with obesity are related to the amount and distribution of body fat, measures that assess visceral or subcutaneous fat, such as waist circumference (WC), waist-to-height ratio (WHtR), or skinfolds thickness may be more suitable. The objective of this study was to develop percentile curves for BMI, WC, WHtR, and sum of 5 skinfolds (SF5) in a representative sample of Canadian children and youth. The analysis used data from 4115 children and adolescents between 6 and 19 years of age that participated in the Canadian Health Measures Survey Cycles 1 (2007/2009) and 2 (2009/2011). BMI, WC, WHtR, and SF5 were measured using standardized procedures. Age- and sex-specific centiles were calculated using the LMS method and the percentiles that intersect the adult cutpoints for BMI, WC, and WHtR at age 18 years were determined. Percentile curves for all measures showed an upward shift compared to curves from the pre-obesity epidemic era. The adult cutoffs for overweight and obesity corresponded to the 72nd and 91st percentile, respectively, for both sexes. The current study has presented for the first time percentile curves for BMI, WC, WHtR, and SF5 in a representative sample of Canadian children and youth. The percentile curves presented are meant to be descriptive rather than prescriptive as associations with cardiovascular disease markers or outcomes were not assessed. PMID:26176769

  3. Elements in autopsy liver tissue samples from Greenlandic Inuit and Danes. V. Selenium measured by X-ray fluorescence spectrometry.

    PubMed

    Milman, Nils; Laursen, Jens; Byg, Keld-Erik; Pedersen, Henning Sloth; Mulvad, Gerd; Hansen, Jens Christian

    2004-01-01

    The content of selenium in normal liver tissue samples from Greenlandic Inuit was measured and the results compared with those obtained in normal liver tissue samples from Danes. Normal liver tissue samples were obtained at autopsy from 50 Greenlandic Inuit (27 men, 23 women) with a median age of 61 years (range 23-83) and from 74 Danes (44 men, 30 women) with a median age of 60 years (range 15-87). Total liver selenium content was measured by X-ray fluorescence spectrometry. The content of selenium (median) was in Inuit 26.6 micromol/kg dry liver (5-95 percentile: 15.2-49.4) and in Danes 17.7 micromol/kg dry liver (5-95 percentile: < 3.8-36.5) (p < 0.0001). Liver selenium content displayed no significant gender difference, either in Inuit or Danes. In Inuit men, there was a negative correlation between liver selenium content and age (rs = -0.39, p < 0.05), whereas Danish men displayed a positive correlation between liver selenium content and age (rs = 0.37, p = 0.02). There was no correlation in Inuit or Danish women. In Inuit, the median hepatic selenium index (liver selenium content divided by age) was 0.48 and in Danes 0.33 (p = 0.001). There was an inverse correlation between hepatic selenium index and age both in Inuit (rs = -0.77, p < 0.0001) and in Danes (rs = -0.47, p < 0.0001). In conclusion, Inuit had a higher liver content of selenium and a higher hepatic selenium index compared with Danes. The more favourable selenium status is due to a higher nutritional selenium intake with fish and meat from sea mammals. PMID:15139392

  4. Examining the Reliability of Student Growth Percentiles Using Multidimensional IRT

    ERIC Educational Resources Information Center

    Monroe, Scott; Cai, Li

    2015-01-01

    Student growth percentiles (SGPs, Betebenner, 2009) are used to locate a student's current score in a conditional distribution based on the student's past scores. Currently, following Betebenner (2009), quantile regression (QR) is most often used operationally to estimate the SGPs. Alternatively, multidimensional item response theory (MIRT) may…

  5. Urinary iodine percentile ranges in the United States

    PubMed Central

    Soldin, Offie Porat; Soldin, Steven J.; Pezzullo, John C.

    2013-01-01

    Background The status of iodine nutrition of a population can be determined by measurement of urinary iodine concentrations since it is thought to indicate dietary iodine intake. Normally, these results are compared to population-based criteria, since there are no reference ranges for urinary iodine. Objective To determine the percentile ranges for urinary iodide (UI) concentrations in normal individuals in the United States. Materials and methods The third National Health and Nutrition Examination Survey (NHANES III) (1988–1994) database of the civilian, non-institutionalized, iodine-sufficient US population was used. The 2.5th to 97.5th percentile ranges for urinary iodine and for urinary iodine per gram creatinine ratio (UI/Cr) (μg/g) were calculated for females and males, 6–89 years of age, each stratified by age groups. Results and conclusions We calculated the percentile ranges for urinary iodine. After exclusions of subjects with goiter or thyroid disease, the study sample included 21,530 subjects; 10,439 males and 11,091 females. For women of childbearing age (14–44 years), urinary iodine concentration 2.5th to 97.5th percentiles are 1.8–65 μg/dl or 36–539 μg/g creatinine. For pregnant women, the ranges are 4.2–55 μg/dl or 33–535 μg/g creatinine. PMID:12559616

  6. Punching Wholes into Parts, or Beating the Percentile Averages.

    ERIC Educational Resources Information Center

    Carwile, Nancy R.

    1990-01-01

    Presents a facetious, ingenious resolution to the percentile dilemma concerning above- and below-average test scores. If schools enrolled the same number of pigs as students and tested both groups, the pigs would fill up the bottom half and all children would rank in the top 50 percent. However, some wrinkles need to be ironed out! (MLH)

  7. Percentile growth charts for biomedical studies using a porcine model.

    PubMed

    Corson, A M; Laws, J; Laws, A; Litten, J C; Lean, I J; Clarke, L

    2008-12-01

    Increasing rates of obesity and heart disease are compromising quality of life for a growing number of people. There is much research linking adult disease with the growth and development both in utero and during the first year of life. The pig is an ideal model for studying the origins of developmental programming. The objective of this paper was to construct percentile growth curves for the pig for use in biomedical studies. The body weight (BW) of pigs was recorded from birth to 150 days of age and their crown-to-rump length was measured over the neonatal period to enable the ponderal index (PI; kg/m3) to be calculated. Data were normalised and percentile curves were constructed using Cole's lambda-mu-sigma (LMS) method for BW and PI. The construction of these percentile charts for use in biomedical research will allow a more detailed and precise tracking of growth and development of individual pigs under experimental conditions. PMID:22444086

  8. Selenium in diet

    MedlinePlus

    ... please enable JavaScript. Selenium is an essential trace mineral. This means your body must get this mineral in the food you eat. Small amounts of ... for your health. Function Selenium is a trace mineral. Your body only needs it in small amounts. ...

  9. Dietary selenium and selenoprotein function

    PubMed Central

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

    2012-01-01

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

  10. Binorm-a fortran subroutine to calculate the percentiles of a standardized binormal distribution

    USGS Publications Warehouse

    McCammon, R.B.

    1977-01-01

    BINORM is a FORTRAN subroutine for calculating the percentiles of a standardized binormal distribution. By using a linear transformation, the percentiles of a binormal distribution can be obtained. The percentiles of a binormal distribution are useful for plotting purposes, for establishing confidence intervals, and for sampling from a mixed population that consists of two normal distributions. ?? 1977.

  11. Mineral Commodity Profiles: Selenium

    USGS Publications Warehouse

    Butterman, W.C.; Brown, R.D., Jr.

    2004-01-01

    Overview -- Selenium, which is one of the chalcogen elements in group 16 (or 6A) of the periodic table, is a semiconductor that is chemically similar to sulfur for which it substitutes in many minerals and synthetic compounds. It is a byproduct of copper refining and, to a much lesser extent, lead refining. It is used in many applications, the major ones being a decolorizer for glass, a metallurgical additive to free-machining varieties of ferrous and nonferrous alloys, a constituent in cadmium sulfoselenide pigments, a photoreceptor in xerographic copiers, and a semiconductor in electrical rectifiers and photocells. Refined selenium amounting to more than 1,800 metric tons (t) was produced by 14 countries in 2000. Japan, Canada, the United States, and Belgium, which were the four largest producers, accounted for nearly 85 percent of world production. An estimated 250 t of the world total is secondary selenium, which is recovered from scrapped xerographic copier drums and selenium rectifiers; the selenium in nearly all other uses is dissipated (not recoverable as waste or scrap). The present selenium reserve bases for the United States and the world (including the United States), which are associated with copper deposits, are expected to be able to satisfy demand for selenium for several decades without difficulty.

  12. Why Nature Chose Selenium.

    PubMed

    Reich, Hans J; Hondal, Robert J

    2016-04-15

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

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

    PubMed Central

    Alexander, Jan; Aaseth, Jan

    2016-01-01

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

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

    PubMed

    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. PMID:24987868

  15. Selenium: finding the delicate balance

    SciTech Connect

    McBride, J.

    1987-01-01

    A deficiency of selenium can lead to the degeneration of heart muscle in children. Yet, an excess of selenium can produce a garlicky breath, and extreme levels can cause a loss of nails and hair. People get adequate selenium in their diets in North America, but there are areas around the world where the people exist on foods containing little or no selenium. A person is said to be in balance when the daily intake of selenium equals the amount excreted. However, the need for the mineral varies depending on the population, as well as the sex, studied. For example, Chinese men living in a selenium-deficient area need only 10 micrograms a day to maintain their body stores of selenium, whereas US men need 80 micrograms. In addition, there is a difference in how the body treats different forms and sources of selenium. The body absorbs the mineral better from plant sources than from animal sources, in many instances.

  16. Percutaneous absorption of selenium sulfide

    SciTech Connect

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

    1986-01-01

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

  17. Selenium isotope analysis

    SciTech Connect

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

    1981-01-01

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

  18. Colorado Growth Model--Brief Report: Student Growth Percentiles and FRL Status. Accountability & Data Analysis Unit

    ERIC Educational Resources Information Center

    Colorado Department of Education, 2013

    2013-01-01

    This report examines the relationship between socioeconomic status, as defined by a free-and-reduced lunch proxy variable, and student growth percentiles by elementary, middle, and high school grade levels for math, reading, and writing. Comparisons were made between median growth percentiles for each educational level by free and reduced lunch…

  19. Selenium Treatment Technologies

    EPA Science Inventory

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

  20. Selenium and Compounds

    Integrated Risk Information System (IRIS)

    Selenium and Compounds ; CASRN 7782 - 49 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  1. Biomarkers of selenium status

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Acute selenium toxicosis in sheep

    SciTech Connect

    Blodgett, D.J.

    1983-01-01

    The toxicity, toxicokinetics, and progressive pathological changes produced by sodium selenite in sheep following parenteral administration were evaluated. In the intramuscular study, the LD/sub 50/ for sodium selenite was 0.7 mg selenium/kg body weight. In the continuous intravenous infusion study, a gradient of tissue selenium/kg body weight with a standard error of 0.035 over a 192 hour observation period. The most evident clinical signs were dyspnea and depression . At necropsy, the most consistent lesions were edematous lungs and pale mottled hearts. Highest tissue selenium concentrations in declining order were found in the liver, kidney, and heart. Four sheep injected intravenously with 0.7 mg selenium/kg body weight survived the 192 hour post-injection observation period. Semilogarithmic plots of blood selenium concentration versus time were triphasic. The ..cap alpha.. and ..gamma.. rate constants of sheep administered a single dose of selenium intravenously were significantly greater than those obtained when sheep were injected intramuscularly with 0.7 mg selenium concentrations was attained with 4, 8, and 12 hour infusions at steady state concentrations of 2500, 3000, and 3500 ppb selenium in the blood. The heart was the target organ of acute selenium toxicosis. A dose-response relationship was observed in the heart with degeneration evident in all hearts and necrosis present in the 2 hearts with the highest concentrations of selenium.

  3. Selenium: metabolism and endocrines (Minireview).

    PubMed

    Brtkova; Brtko

    1996-09-01

    Selenium occurs both in prokaryocytes and eukaryocytes as a component of selenoenzymes or selenoproteins. Approximately 80 % of selenium in animal or human body occurs in the form of seleno-L-cysteine, an amino acid encoded by one of standard termination codons. Selenium is an integral component of the active site of glutathione peroxidases which plays an important role in the antioxidant system. Iodothyronine 5-deiodinase, type I is also a selenoenzyme consisting of two identical subunits which catalyzes a reductive monodeiodination of iodothyronine residues of the phenolic ring. General characteristics of several selenoproteins and selenium binding proteins are summarized, also certain facts on the effects of selenium deficiency in man and its distribution and toxicity in higher organisms, are reviewed. Selenium status in the population from selected regions in Slovakia is reported and compared with that in other countries. PMID:10979042

  4. Selenium biomineralization for biotechnological applications.

    PubMed

    Nancharaiah, Yarlagadda V; Lens, Piet N L

    2015-06-01

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

  5. Development of a percentile based three-dimensional model of the buttocks in computer system

    NASA Astrophysics Data System (ADS)

    Wang, Lijing; He, Xueli; Li, Hongpeng

    2016-04-01

    There are diverse products related to human buttocks, which need to be designed, manufactured and evaluated with 3D buttock model. The 3D buttock model used in present research field is just simple approximate model similar to human buttocks. The 3D buttock percentile model is highly desired in the ergonomics design and evaluation for these products. So far, there is no research on the percentile sizing system of human 3D buttock model. So the purpose of this paper is to develop a new method for building three-dimensional buttock percentile model in computer system. After scanning the 3D shape of buttocks, the cloud data of 3D points is imported into the reverse engineering software (Geomagic) for the reconstructing of the buttock surface model. Five characteristic dimensions of the buttock are measured through mark-points after models being imported into engineering software CATIA. A series of space points are obtained by the intersecting of the cutting slices and 3D buttock surface model, and then are ordered based on the sequence number of the horizontal and vertical slices. The 1st, 5th, 50th, 95th, 99th percentile values of the five dimensions and the spatial coordinate values of the space points are obtained, and used to reconstruct percentile buttock models. This research proposes a establishing method of percentile sizing system of buttock 3D model based on the percentile values of the ischial tuberosities diameter, the distances from margin to ischial tuberosity and the space coordinates value of coordinate points, for establishing the Nth percentile 3D buttock model and every special buttock types model. The proposed method also serves as a useful guidance for the other 3D percentile models establishment for other part in human body with characteristic points.

  6. Development of a percentile based three-dimensional model of the buttocks in computer system

    NASA Astrophysics Data System (ADS)

    Wang, Lijing; He, Xueli; Li, Hongpeng

    2016-05-01

    There are diverse products related to human buttocks, which need to be designed, manufactured and evaluated with 3D buttock model. The 3D buttock model used in present research field is just simple approximate model similar to human buttocks. The 3D buttock percentile model is highly desired in the ergonomics design and evaluation for these products. So far, there is no research on the percentile sizing system of human 3D buttock model. So the purpose of this paper is to develop a new method for building three-dimensional buttock percentile model in computer system. After scanning the 3D shape of buttocks, the cloud data of 3D points is imported into the reverse engineering software (Geomagic) for the reconstructing of the buttock surface model. Five characteristic dimensions of the buttock are measured through mark-points after models being imported into engineering software CATIA. A series of space points are obtained by the intersecting of the cutting slices and 3D buttock surface model, and then are ordered based on the sequence number of the horizontal and vertical slices. The 1st, 5th, 50th, 95th, 99th percentile values of the five dimensions and the spatial coordinate values of the space points are obtained, and used to reconstruct percentile buttock models. This research proposes a establishing method of percentile sizing system of buttock 3D model based on the percentile values of the ischial tuberosities diameter, the distances from margin to ischial tuberosity and the space coordinates value of coordinate points, for establishing the Nth percentile 3D buttock model and every special buttock types model. The proposed method also serves as a useful guidance for the other 3D percentile models establishment for other part in human body with characteristic points.

  7. Selenium incorporation using recombinant techniques

    SciTech Connect

    Walden, Helen

    2010-04-01

    An overview of techniques for recombinant incorporation of selenium and subsequent purification and crystallization of the resulting labelled protein. Using selenomethionine to phase macromolecular structures is common practice in structure determination, along with the use of selenocysteine. Selenium is consequently the most commonly used heavy atom for MAD. In addition to the well established recombinant techniques for the incorporation of selenium in prokaryal expression systems, there have been recent advances in selenium labelling in eukaryal expression, which will be discussed. Tips and things to consider for the purification and crystallization of seleno-labelled proteins are also included.

  8. Selenium for preventing cancer

    PubMed Central

    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

  9. Hypothesis Testing of Population Percentiles via the Wald Test with Bootstrap Variance Estimates

    PubMed Central

    Johnson, William D.; Romer, Jacob E.

    2016-01-01

    Testing the equality of percentiles (quantiles) between populations is an effective method for robust, nonparametric comparison, especially when the distributions are asymmetric or irregularly shaped. Unlike global nonparametric tests for homogeneity such as the Kolmogorv-Smirnov test, testing the equality of a set of percentiles (i.e., a percentile profile) yields an estimate of the location and extent of the differences between the populations along the entire domain. The Wald test using bootstrap estimates of variance of the order statistics provides a unified method for hypothesis testing of functions of the population percentiles. Simulation studies are conducted to show performance of the method under various scenarios and to give suggestions on its use. Several examples are given to illustrate some useful applications to real data. PMID:27034909

  10. Shaping in the 21st century: Moving percentile schedules into applied settings

    PubMed Central

    Galbicka, Gregory

    1994-01-01

    The present paper provides a primer on percentile reinforcement schedules, which have been used for two decades to study response differentiation and shaping in the laboratory. Arranged in applied settings, percentile procedures could be used to specify response criteria, standardizing treatment across subjects, trainers, and times to provide a more consistent training environment while maintaining the sensitivity to the individual's repertoire that is the hallmark of shaping. Percentile schedules are also valuable tools in analyzing the variables of which responding is a function, both inside and outside the laboratory. Finally, by formalizing the rules of shaping, percentile schedules provide a useful heuristic of the processes involved in shaping behavior, even for those situations that may not easily permit their implementation. As such, they may help further sensitize trainers and researchers alike to variables of critical importance in behavior change. ImagesFigure 6 PMID:16795849

  11. Comparison of daily percentiles of streamflow and rainfall to investigate stream aquifer connectivity

    NASA Astrophysics Data System (ADS)

    Brodie, Ross S.; Hostetler, Stephen; Slatter, Emily

    2008-01-01

    SummaryA frequency analysis approach was used to investigate the hydraulic connectivity between streams and aquifers, by comparing daily percentiles of streamflow and rainfall. Three Australian streams were examined - a dominantly gaining stream (Wilsons River, NSW), a dominantly gaining stream modified by significant water extraction (Ovens River, Victoria) and a dominantly losing stream (Mooki River, NSW). For the gaining stream examples, a lag is observed between the seasonal peak in the low-flow percentile curves and the seasonal peak in the daily rainfall percentile curve. Cross-correlation was used to calculate the time-shift that provides the best fit between the streamflow and rainfall percentile curves. There is a good correlation ( r2 > 0.8) between the reference rainfall percentile curve and the shifted streamflow percentile curves for gaining streams. The lags evident between the rainfall and streamflow percentile curves represent the processes of first replenishing catchment storages (such as soil moisture and groundwater) and subsequent release to the stream. This is largely a function of catchment hydrogeology as well as climate, notably the magnitude and regularity of rainfall events. Catchment size is not a controlling factor. Analysis of these lags provides insights into the dynamics of groundwater recharge, storage and release. Changes in the lag times over the flow percentiles can reflect changes in the dominant catchment storage contributing to streamflow. For the Wilsons River, the contribution from a groundwater system with longer flow paths increases at lower flow percentiles. This can be critical when protecting minimum streamflows, as near-stream groundwater flow may not be the only determining factor. The impact of water extraction can be recognised in this analysis. For the Ovens River, streamflow deficits relative to the rainfall percentile curve correspond to the summer period of high irrigation demand. Such a deficit was also observed

  12. Analysis of extreme top event frequency percentiles based on fast probability integration

    SciTech Connect

    Staple, B.; Haskin, F.E.

    1993-10-01

    In risk assessments, a primary objective is to determine the frequency with which a collection of initiating and basic events, E{sub e} leads to some undesired top event, T. Uncertainties in the occurrence rates, x{sub t}, assigned to the initiating and basic events cause uncertainty in the top event frequency, z{sub T}. The quantification of the uncertainty in z{sub T} is an essential part of risk assessment called uncertainty analysis. In the past, it has been difficult to evaluate the extreme percentiles of output variables like z{sub T}. Analytic methods such as the method of moments do not provide estimates of output percentiles and the Monte Carlo (MC) method can be used to estimate extreme output percentiles only by resorting to large sample sizes. A promising altemative to these methods is the fast probability integration (FPI) methods. These methods approximate the integrals of multi-variate functions, representing percentiles of interest, without recourse to multi-dimensional numerical integration. FPI methods give precise results and have been demonstrated to be more efficient than MC methods for estimating extreme output percentiles. FPI allows the analyst to choose extreme percentiles of interest and perform sensitivity analyses in those regions. Such analyses can provide valuable insights as to the events driving the top event frequency response in extreme probability regions. In this paper, FPI methods are adapted a) to precisely estimate extreme top event frequency percentiles and b) to allow the quantification of sensitivity measures at these extreme percentiles. In addition, the relative precision and efficiency of alternative methods for treating lognormally distributed inputs is investigated. The methodology is applied to the top event frequency expression for the dominant accident sequence from a risk assessment of Grand Gulf nuclear power plant.

  13. Selenium accumulation in lettuce germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. CONFERENCES AND SYMPOSIA Commemoration of the 85th birthday of S I Syrovatskii(Scientific session of the Physical Sciences Division of the Russian Academy of Sciences, 26 May 2010)

    NASA Astrophysics Data System (ADS)

    2010-12-01

    A scientific session of the Physical Sciences Division, Russian Academy of Sciences (RAS), was held on 26 May 2010 at the conference hall of the Lebedev Physical Institute, RAS. The session was devoted to the 85th birthday of S I Syrovatskii. The program announced on the web page of the RAS Physical Sciences Division (www.gpad.ac.ru) contained the following reports: (1) Zelenyi L M (Space Research Institute, RAS, Moscow) "Current sheets and reconnection in the geomagnetic tail"; (2) Frank A G (Prokhorov General Physics Institute, RAS, Moscow) "Dynamics of current sheets as the cause of flare events in magnetized plasmas"; (3) Kuznetsov V D (Pushkov Institute of Terrestrial Magnetism, the Ionosphere, and Radio Wave Propagation, RAS, Troitsk, Moscow region) "Space research on the Sun"; (4) Somov B V (Shternberg Astronomical Institute, Lomonosov Moscow State University, Moscow) "Strong shock waves and extreme plasma states"; (5) Zybin K P (Lebedev Physical Institute, RAS, Moscow) "Structure functions for developed turbulence"; (6) Ptuskin V S (Pushkov Institute of Terrestrial Magnetism, the Ionosphere, and Radio Wave Propagation, RAS, Troitsk, Moscow region) "The origin of cosmic rays." Papers based on reports 1-4 and 6 are published in what follows. • Metastability of current sheets, L M Zelenyi, A V Artemyev, Kh V Malova, A A Petrukovich, R Nakamura Physics-Uspekhi, 2010, Volume 53, Number 9, Pages 933-941 • Dynamics of current sheets underlying flare-type events in magnetized plasmas, A G Frank Physics-Uspekhi, 2010, Volume 53, Number 9, Pages 941-947 • Space research of the Sun, V D Kuznetsov Physics-Uspekhi, 2010, Volume 53, Number 9, Pages 947-954 • Magnetic reconnection in solar flares, B V Somov Physics-Uspekhi, 2010, Volume 53, Number 9, Pages 954-958 • The origin of cosmic rays, V S Ptuskin Physics-Uspekhi, 2010, Volume 53, Number 9, Pages 958-961

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

    PubMed

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

    1999-07-01

    In May 1996, 150 grower pigs in 5 California counties were exposed to selenium-contaminated feed distributed by a single feed company. Feed samples from 20 herds had a mean selenium concentration of 121.7 ppm dry weight (range, 22.1-531 ppm). In San Luis Obispo County, 52 pigs in 24 herds were exposed to the feed, and 8 pigs died with signs of paralysis. Bilateral symmetrical poliomyelomalacia involving the ventral horns of the cervical and lumbar intumescence was evident on histologic examination of spinal cord from affected pigs. Of 44 surviving exposed pigs, 33 (75%) exhibited signs of selenosis, including anorexia, alopecia, and hoof lesions. Thirty-nine of 44 pigs (88.6%) had elevated (>1 ppm) blood selenium concentrations. Surviving exposed pigs were changed to a standard commercial ration containing approximately 0.5 ppm (dry weight) selenium. Blood selenium concentrations were determined weekly for 46 days following removal of the contaminated feed and were compared with values of 20 control pigs fed a standard commercial ration. Mean (+/-SD) blood selenium concentrations of exposed pigs were 3.2 +/- 2.6 ppm at the initial sampling and 0.4 +/- 0.1 ppm after 46 days. Mean blood selenium concentrations of < or = 0.3 ppm for control pigs at all samplings were significantly lower (P < 0.001) than concentrations for exposed pigs. Muscle and liver samples of 22 of the 44 exposed pigs were collected at slaughter approximately 72 days after withdrawal of the selenium-contaminated feed. Muscle samples had a mean selenium concentration of 0.36 ppm (wet weight). Liver samples had a mean selenium concentration of 1.26 ppm (wet weight). One liver sample had a selenium value in the toxic range for pigs (3.3 ppm wet weight; reference range, 0.4-1.2 ppm). A 1-compartment pharmacokinetic model of selenium elimination in exposed pigs was generated, and the geometric mean blood selenium elimination half-life was estimated to be 12 days. The 60-day withdrawal time recommended

  16. Arsenic and Selenium

    NASA Astrophysics Data System (ADS)

    Plant, J. A.; Kinniburgh, D. G.; Smedley, P. L.; Fordyce, F. M.; Klinck, B. A.

    2003-12-01

    Arsenic (As) and selenium (Se) have become increasingly important in environmental geochemistry because of their significance to human health. Their concentrations vary markedly in the environment, partly in relation to geology and partly as a result of human activity. Some of the contamination evident today probably dates back to the first settled civilizations which used metals.Arsenic is in group 15 of the periodic table (Table 1) and is usually described as a metalloid. It has only one stable isotope, 75As. It can exist in the -III, -I, 0, III, and V oxidation states (Table 2).

  17. NIH peer review percentile scores are poorly predictive of grant productivity

    PubMed Central

    Fang, Ferric C; Bowen, Anthony; Casadevall, Arturo

    2016-01-01

    Peer review is widely used to assess grant applications so that the highest ranked applications can be funded. A number of studies have questioned the ability of peer review panels to predict the productivity of applications, but a recent analysis of grants funded by the National Institutes of Health (NIH) in the US found that the percentile scores awarded by peer review panels correlated with productivity as measured by citations of grant-supported publications. Here, based on a re-analysis of these data for the 102,740 funded grants with percentile scores of 20 or better, we report that these percentile scores are a poor discriminator of productivity. This underscores the limitations of peer review as a means of assessing grant applications in an era when typical success rates are often as low as about 10%. DOI: http://dx.doi.org/10.7554/eLife.13323.001 PMID:26880623

  18. Estimation of a monotone percentile residual life function under random censorship.

    PubMed

    Franco-Pereira, Alba M; de Uña-Álvarez, Jacobo

    2013-01-01

    In this paper, we introduce a new estimator of a percentile residual life function with censored data under a monotonicity constraint. Specifically, it is assumed that the percentile residual life is a decreasing function. This assumption is useful when estimating the percentile residual life of units, which degenerate with age. We establish a law of the iterated logarithm for the proposed estimator, and its n-equivalence to the unrestricted estimator. The asymptotic normal distribution of the estimator and its strong approximation to a Gaussian process are also established. We investigate the finite sample performance of the monotone estimator in an extensive simulation study. Finally, data from a clinical trial in primary biliary cirrhosis of the liver are analyzed with the proposed methods. One of the conclusions of our work is that the restricted estimator may be much more efficient than the unrestricted one. PMID:23225621

  19. NIH peer review percentile scores are poorly predictive of grant productivity.

    PubMed

    Fang, Ferric C; Bowen, Anthony; Casadevall, Arturo

    2016-01-01

    Peer review is widely used to assess grant applications so that the highest ranked applications can be funded. A number of studies have questioned the ability of peer review panels to predict the productivity of applications, but a recent analysis of grants funded by the National Institutes of Health (NIH) in the US found that the percentile scores awarded by peer review panels correlated with productivity as measured by citations of grant-supported publications. Here, based on a re-analysis of these data for the 102,740 funded grants with percentile scores of 20 or better, we report that these percentile scores are a poor discriminator of productivity. This underscores the limitations of peer review as a means of assessing grant applications in an era when typical success rates are often as low as about 10%. PMID:26880623

  20. Selenium semiconductor core optical fibers

    SciTech Connect

    Tang, G. W.; Qian, Q. Peng, K. L.; Wen, X.; Zhou, G. X.; Sun, M.; Chen, X. D.; Yang, Z. M.

    2015-02-15

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

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

    PubMed

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

    2013-09-01

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

  2. Problems with Percentiles: Student Growth Scores in New York's Teacher Evaluation System

    ERIC Educational Resources Information Center

    Patrick, Drew

    2016-01-01

    New York State has used the Growth Model for Educator Evaluation ratings since the 2011-2012 school year. Since that time, student growth percentiles have been used as the basis for teacher and principal ratings. While a great deal has been written about the use of student test scores to measures educator effectiveness, less attention has been…

  3. Percentile Norms for the AAHPER Cooperative Physical Education Tests. Research Report.

    ERIC Educational Resources Information Center

    Moodie, Allan G.

    Percentile scores for Vancouver students in grades 9, 10, 11 and 12 on the AAHPER Cooperative Physical Education Tests are presented. Two of the six forms of the tests were used in these administrations. Every form consists of 60 multiple-choice questions to be completed in 40 minutes. A single score, based on the number of questions answered…

  4. Can Percentiles Replace Raw Scores in the Statistical Analysis of Test Data?

    ERIC Educational Resources Information Center

    Zimmerman, Donald W.; Zumbo, Bruno D.

    2005-01-01

    Educational and psychological testing textbooks typically warn of the inappropriateness of performing arithmetic operations and statistical analysis on percentiles instead of raw scores. This seems inconsistent with the well-established finding that transforming scores to ranks and using nonparametric methods often improves the validity and power…

  5. A Comparison of Growth Percentile and Value-Added Models of Teacher Performance. Working Paper #39

    ERIC Educational Resources Information Center

    Guarino, Cassandra M.; Reckase, Mark D.; Stacy, Brian W.; Wooldridge, Jeffrey M.

    2014-01-01

    School districts and state departments of education frequently must choose between a variety of methods to estimating teacher quality. This paper examines under what circumstances the decision between estimators of teacher quality is important. We examine estimates derived from student growth percentile measures and estimates derived from commonly…

  6. Birthweight percentiles for twin birth neonates by gestational age in China.

    PubMed

    Zhang, Bin; Cao, Zhongqiang; Zhang, Yiming; Yao, Cong; Xiong, Chao; Zhang, Yaqi; Wang, Youjie; Zhou, Aifen

    2016-01-01

    Localized birthweight references for gestational ages serve as an essential tool in accurate evaluation of atypical birth outcomes. Such references for twin births are currently not available in China. The aim of this study was to construct up-to-data sex specific birth weight references by gestational ages for twin births in China. We conducted a population-based analysis on the data of 22,507 eligible living twin infants with births dated between 8/01/2006 and 8/31/2015 from all 95 hospitals within the Wuhan area. Gestational ages in complete weeks were determined using a combination of last-menstrual-period based (LMP) estimation and ultrasound examination. Smoothed percentile curves were created by the Lambda Mu Sigma (LMS) method. Reference of the 3(rd), 10(th), 25(th), 50(th), 75(th), 90(th), 97(th) percentiles birth weight by sex and gestational age were made using 11,861 male and 10,646 female twin newborns with gestational age 26-42 weeks. Separate birthweight percentiles curves for male and female twins were constructed. In summary, our study firstly presents percentile curves of birthweight by gestational age for Chinese twin neonates. Further research is required for the validation and implementation of twin birthweight curves into clinical practice. PMID:27506479

  7. Age-specific percentile-based reference curve of serum procalcitonin concentrations in Japanese preterm infants.

    PubMed

    Fukuzumi, Noriko; Osawa, Kayo; Sato, Itsuko; Iwatani, Sota; Ishino, Ruri; Hayashi, Nobuhide; Iijima, Kazumoto; Saegusa, Jun; Morioka, Ichiro

    2016-01-01

    Procalcitonin (PCT) levels are elevated early after birth in newborn infants; however, the physiological features and reference of serum PCT concentrations have not been fully studied in preterm infants. The aims of the current study were to establish an age-specific percentile-based reference curve of serum PCT concentrations in preterm infants and determine the features. The PCT concentration peaked in infants at 1 day old and decreased thereafter. At 1 day old, serum PCT concentrations in preterm infants <34 weeks' gestational age were higher than those in late preterm infants between 34 and 36 weeks' gestational age or term infants ≥37 weeks' gestational age. Although the 50-percentile value in late preterm and term infants reached the adult normal level (0.1 ng/mL) at 5 days old, it did not in preterm infants. It took 9 weeks for preterm infants to reach it. Serum PCT concentrations at onset in late-onset infected preterm infants were over the 95-percentile value. We showed that the physiological feature in preterm infants was significantly different from that in late preterm infants, even in those <37 weeks' gestational age. To detect late-onset bacterial infection and sepsis, an age-specific percentile-based reference curve may be useful in preterm infants. PMID:27033746

  8. Age-specific percentile-based reference curve of serum procalcitonin concentrations in Japanese preterm infants

    PubMed Central

    Fukuzumi, Noriko; Osawa, Kayo; Sato, Itsuko; Iwatani, Sota; Ishino, Ruri; Hayashi, Nobuhide; Iijima, Kazumoto; Saegusa, Jun; Morioka, Ichiro

    2016-01-01

    Procalcitonin (PCT) levels are elevated early after birth in newborn infants; however, the physiological features and reference of serum PCT concentrations have not been fully studied in preterm infants. The aims of the current study were to establish an age-specific percentile-based reference curve of serum PCT concentrations in preterm infants and determine the features. The PCT concentration peaked in infants at 1 day old and decreased thereafter. At 1 day old, serum PCT concentrations in preterm infants <34 weeks’ gestational age were higher than those in late preterm infants between 34 and 36 weeks’ gestational age or term infants ≥37 weeks’ gestational age. Although the 50-percentile value in late preterm and term infants reached the adult normal level (0.1 ng/mL) at 5 days old, it did not in preterm infants. It took 9 weeks for preterm infants to reach it. Serum PCT concentrations at onset in late-onset infected preterm infants were over the 95-percentile value. We showed that the physiological feature in preterm infants was significantly different from that in late preterm infants, even in those <37 weeks’ gestational age. To detect late-onset bacterial infection and sepsis, an age-specific percentile-based reference curve may be useful in preterm infants. PMID:27033746

  9. AGE AND GENDER SPECIFIC BMI PERCENTILES ARE LIMITED FOR TRACKING THE CHILDHOOD OBESITY EPIDEMIC

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purpose: To evaluate pediatric nutrition and physical activity interventions a reliable and feasible way of tracking change in body status is needed. Historically, body mass index (BMI) has been used in adults. BMI percentiles or Z scores, which are theoretically age and gender adjusted, have been...

  10. Student Growth Percentiles Based on MIRT: Implications of Calibrated Projection. CRESST Report 842

    ERIC Educational Resources Information Center

    Monroe, Scott; Cai, Li; Choi, Kilchan

    2014-01-01

    This research concerns a new proposal for calculating student growth percentiles (SGP, Betebenner, 2009). In Betebenner (2009), quantile regression (QR) is used to estimate the SGPs. However, measurement error in the score estimates, which always exists in practice, leads to bias in the QR-­based estimates (Shang, 2012). One way to address this…

  11. Risk for nonalcoholic fatty liver disease in Hispanic Youth with BMI > or = 95th percentile

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To characterize children at risk for nonalcoholic fatty liver disease (NAFLD) and to explore possible mechanisms underlying the development of NAFLD in Hispanic youth with a body mass index > or =95th percentile. Hispanic nonoverweight (n = 475) and overweight (n = 517) children, ages 4 to 19 y, wer...

  12. User Guide for the 2014-15 Teacher Median Student Growth Percentile Report

    ERIC Educational Resources Information Center

    New Jersey Department of Education, 2016

    2016-01-01

    On March 22, 2016, the New Jersey Department of Education ("the Department") published a broadcast memo sharing secure district access to 2014-15 median Student Growth Percentile (mSGP) data for all qualifying teachers. These data describe student growth from the last school year, and comprise 10% of qualifying teachers' 2014-15…

  13. Birthweight percentiles for twin birth neonates by gestational age in China

    PubMed Central

    Zhang, Bin; Cao, Zhongqiang; Zhang, Yiming; Yao, Cong; Xiong, Chao; Zhang, Yaqi; Wang, Youjie; Zhou, Aifen

    2016-01-01

    Localized birthweight references for gestational ages serve as an essential tool in accurate evaluation of atypical birth outcomes. Such references for twin births are currently not available in China. The aim of this study was to construct up-to-data sex specific birth weight references by gestational ages for twin births in China. We conducted a population-based analysis on the data of 22,507 eligible living twin infants with births dated between 8/01/2006 and 8/31/2015 from all 95 hospitals within the Wuhan area. Gestational ages in complete weeks were determined using a combination of last-menstrual-period based (LMP) estimation and ultrasound examination. Smoothed percentile curves were created by the Lambda Mu Sigma (LMS) method. Reference of the 3rd, 10th, 25th, 50th, 75th, 90th, 97th percentiles birth weight by sex and gestational age were made using 11,861 male and 10,646 female twin newborns with gestational age 26–42 weeks. Separate birthweight percentiles curves for male and female twins were constructed. In summary, our study firstly presents percentile curves of birthweight by gestational age for Chinese twin neonates. Further research is required for the validation and implementation of twin birthweight curves into clinical practice. PMID:27506479

  14. Using Percentile Schedules to Increase Eye Contact in Children with Fragile X Syndrome

    ERIC Educational Resources Information Center

    Hall, Scott S.; Maynes, Natalee P.; Reiss, Allan L.

    2009-01-01

    Aversion to eye contact is a common behavior of individuals diagnosed with Fragile X syndrome (FXS); however, no studies to date have attempted to increase eye-contact duration in these individuals. In this study, we employed a percentile reinforcement schedule with and without overcorrection to shape eye-contact duration of 6 boys with FXS.…

  15. Production of selenium-72 and arsenic-72

    DOEpatents

    Phillips, Dennis R.

    1993-01-01

    Methods 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.

  16. Production of selenium-72 and arsenic-72

    DOEpatents

    Phillips, D.R.

    1993-04-20

    Methods 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.

  17. Selenium transformation in coal mine spoils

    SciTech Connect

    Atalay, A.; Koll, K.J.

    1990-09-01

    The objective of this part of the study is to investigate the oxidation-reduction (redox) environment that favor the release of selenium from coal mine spoils. It is anticipated that the study will help answer critical questions as to the form, solubility, and mobility of selenium from the spoil site to the surrounding environment. This investigation will evaluate the conditions which favor the speciation of selenium from coal mine spoils as affected by changes in the oxidation states of selenium.

  18. Mercury and selenium interaction: A review

    SciTech Connect

    Cuvin-Aralar, M.L.; Furness, R.W. )

    1991-06-01

    This paper reviews studies on mercury and selenium interaction. It includes the effects of selenium on mercury toxicity on the organism, organ/tissue, and subcellular levels. The paper also touches on possible mechanisms for the protective action of selenium against mercury toxicity and deals briefly with the synergism between the two elements. 71 references.

  19. 21 CFR 573.920 - Selenium.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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...

  20. 21 CFR 573.920 - Selenium.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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...

  1. Selenium in the environment and human health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although selenium was shown to affect biological systems over 80 years ago and was recognized as an essential micronutrient in the mid-20th century, the "flowering" of the selenium field has taken place in the 21st century. The biological function of selenium through selenoproteins has been firmly e...

  2. Selenium and inflammatory bowel disease.

    PubMed

    Kudva, Avinash K; Shay, Ashley E; Prabhu, K Sandeep

    2015-07-15

    Dietary intake of the micronutrient selenium is essential for normal immune functions. Selenium is cotranslationally incorporated as the 21st amino acid, selenocysteine, into selenoproteins that function to modulate pathways involved in inflammation. Epidemiological studies have suggested an inverse association between selenium levels and inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis that can potentially progress to colon cancer. However, the underlying mechanisms are not well understood. Here we summarize the current literature on the pathophysiology of IBD, which is multifactorial in origin with unknown etiology. We have focused on a few selenoproteins that mediate gastrointestinal inflammation and activate the host immune response, wherein macrophages play a pivotal role. Changes in cellular oxidative state coupled with altered expression of selenoproteins in macrophages drive the switch from a proinflammatory phenotype to an anti-inflammatory phenotype to efficiently resolve inflammation in the gut and restore epithelial barrier integrity. Such a phenotypic plasticity is accompanied by changes in cytokines, chemokines, and bioactive metabolites, including eicosanoids that not only mitigate inflammation but also partake in restoring gut homeostasis through diverse pathways involving differential regulation of transcription factors such as nuclear factor-κB and peroxisome proliferator-activated receptor-γ. The role of the intestinal microbiome in modulating inflammation and aiding in selenium-dependent resolution of gut injury is highlighted to provide novel insights into the beneficial effects of selenium in IBD. PMID:26045617

  3. [Selenium status in population of Irkutsk region].

    PubMed

    Golubkina, N A; Parfenova, E O; Reshetnik, L A

    1998-01-01

    The human selenium status in 10 locations of Irkutsk region (n = 216) is estimated using serum and hair selenium as biological markers. Extremely low serum selenium was typical for the inhabitants of Angara area (63-84 mcg/l). Hair selenium varied from 504 mcg/kg to 718 mcg/kg, the lowest values being found in Shelehov and Angarsk, the highest--in Karam and Mama. Low selenium concentrations were found also in the main food products: cereals--49-89 mcg/kg, meat--234-489 mcg/kg of dry weight, bread--106-180 mcg/kg of dry weight. PMID:9825469

  4. Statewide Analysis of the Drainage-Area Ratio Method for 34 Streamflow Percentile Ranges in Texas

    USGS Publications Warehouse

    Asquith, William H.; Roussel, Meghan C.; Vrabel, Joseph

    2006-01-01

    The drainage-area ratio method commonly is used to estimate streamflow for sites where no streamflow data are available using data from one or more nearby streamflow-gaging stations. The method is intuitive and straightforward to implement and is in widespread use by analysts and managers of surface-water resources. The method equates the ratio of streamflow at two stream locations to the ratio of the respective drainage areas. In practice, unity often is assumed as the exponent on the drainage-area ratio, and unity also is assumed as a multiplicative bias correction. These two assumptions are evaluated in this investigation through statewide analysis of daily mean streamflow in Texas. The investigation was made by the U.S. Geological Survey in cooperation with the Texas Commission on Environmental Quality. More than 7.8 million values of daily mean streamflow for 712 U.S. Geological Survey streamflow-gaging stations in Texas were analyzed. To account for the influence of streamflow probability on the drainage-area ratio method, 34 percentile ranges were considered. The 34 ranges are the 4 quartiles (0-25, 25-50, 50-75, and 75-100 percent), the 5 intervals of the lower tail of the streamflow distribution (0-1, 1-2, 2-3, 3-4, and 4-5 percent), the 20 quintiles of the 4 quartiles (0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, 40-45, 45-50, 50-55, 55-60, 60-65, 65-70, 70-75, 75-80, 80-85, 85-90, 90-95, and 95-100 percent), and the 5 intervals of the upper tail of the streamflow distribution (95-96, 96-97, 97-98, 98-99 and 99-100 percent). For each of the 253,116 (712X711/2) unique pairings of stations and for each of the 34 percentile ranges, the concurrent daily mean streamflow values available for the two stations provided for station-pair application of the drainage-area ratio method. For each station pair, specific statistical summarization (median, mean, and standard deviation) of both the exponent and bias-correction components of the drainage-area ratio

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

    PubMed

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

    2013-01-01

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

  6. Selenium metabolite levels in human urine after dosing selenium in different chemical forms

    SciTech Connect

    Hasunuma, Ryoichi; Tsuda, Morizo; Ogawa, Tadao; Kawanishi, Yasuhiro

    1993-11-01

    It has been well known that selenium in marine fish such as tuna and swordfish protects the toxicity of methylmercury in vivo. The protective potency might depend on the chemical forms of selenium in the meat of marine fish sebastes and sperm whale. Little has been revealed, however, on the chemical forms of selenium in the meat of these animals or the selenium metabolites in urine, because the amount of the element is very scarce. Urine is the major excretory route for selenium. The chemical forms of urinary selenium may reflect the metabolism of the element. We have developed methodology for analysis of selenium-containing components in human urine. Using this method, we have observed the time courses of excretory levels of urinary selenium components after a single dose of selenium as selenious acid, selenomethionine, trimethylselenonium ion or tuna meat. 14 refs., 6 figs., 1 tab.

  7. Relationships between walking and percentiles of adiposity inolder and younger men

    SciTech Connect

    Williams, Paul T.

    2005-06-01

    To assess the relationship of weekly walking distance to percentiles of adiposity in elders (age {ge} 75 years), seniors (55 {le} age <75 years), middle-age men (35 {le} age <55 years), and younger men (18 {le} age <35 years old). Cross-sectional analyses of baseline questionnaires from 7,082 male participants of the National Walkers Health Study. The walkers BMIs were inversely and significantly associated with walking distance (kg/m{sup 2} per km/wk) in elders (slope {+-} SE: -0.032 {+-} 0.008), seniors (-0.045 {+-} 0.005), and middle-aged men (-0.037 {+-} 0.007), as were their waist circumferences (-0.091 {+-} 0.025, -0.045 {+-} 0.005, and -0.091 {+-} 0.015 cm per km/wk, respectively), and these slopes remained significant when adjusted statistically for reported weekly servings of meat, fish, fruit, and alcohol. The declines in BMI associated with walking distance were greater at the higher than lower percentiles of the BMI distribution. Specifically, compared to the decline at the 10th BMI percentile, the decline in BMI at the 90th percentile was 5.1-fold greater in elders, 5.9-fold greater in seniors, and 6.7-fold greater in middle-age men. The declines in waist circumference associated with walking distance were also greater among men with broader waistlines. Exercise-induced weight loss (or self-selection) causes an inverse relationship between adiposity and walking distance in men 35 and older that is substantially greater among fatter men.

  8. Selenium speciation in ground water

    SciTech Connect

    Atalay, A.

    1990-07-10

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

  9. Selenium Content in Seafood in Japan

    PubMed Central

    Yamashita, Yumiko; Yamashita, Michiaki; Iida, Haruka

    2013-01-01

    Selenium is an essential micronutrient for humans, and seafood is one of the major selenium sources, as well as red meat, grains, eggs, chicken, liver and garlic. A substantial proportion of the total amount of selenium is present as selenium containing imidazole compound, selenoneine, in the muscles of ocean fish. In order to characterize the selenium content in seafood, the total selenium levels were measured in the edible portions of commercially important fish and shellfish species. Among the tested edible portions, alfonsino muscle had the highest selenium levels (concentration of 1.27 mg/kg tissue). High levels of selenium (1.20–1.07 mg/kg) were also found in the salted ovary products of mullet and Pacific herring. In other fish muscles, the selenium levels ranged between 0.12 and 0.77 mg/kg tissue. The selenium levels were closely correlated with the mercury levels in the white and red muscles in alfonsino. The selenium content in spleen, blood, hepatopancreas, heart, red muscle, white muscle, brain, ovary and testis ranged between 1.10 and 24.8 mg/kg tissue in alfonsino. PMID:23434904

  10. Trend estimates of AERONET-observed and model-simulated AOT percentiles between 1993 and 2013

    NASA Astrophysics Data System (ADS)

    Yoon, Jongmin; Pozzer, Andrea; Chang, Dong Yeong; Lelieveld, Jos

    2016-04-01

    Recent Aerosol Optical thickness (AOT) trend studies used monthly or annual arithmetic means that discard details of the generally right-skewed AOT distributions. Potentially, such results can be biased by extreme values (including outliers). This study additionally uses percentiles (i.e., the lowest 5%, 25%, 50%, 75% and 95% of the monthly cumulative distributions fitted to Aerosol Robotic Network (AERONET)-observed and ECHAM/MESSy Atmospheric Chemistry (EMAC)-model simulated AOTs) that are less affected by outliers caused by measurement error, cloud contamination and occasional extreme aerosol events. Since the limited statistical representativeness of monthly percentiles and means can lead to bias, this study adopts the number of observations as a weighting factor, which improves the statistical robustness of trend estimates. By analyzing the aerosol composition of AERONET-observed and EMAC-simulated AOTs in selected regions of interest, we distinguish the dominant aerosol types and investigate the causes of regional AOT trends. The simulated and observed trends are generally consistent with a high correlation coefficient (R = 0.89) and small bias (slope±2σ = 0.75 ± 0.19). A significant decrease in EMAC-decomposed AOTs by water-soluble compounds and black carbon is found over the USA and the EU due to environmental regulation. In particular, a clear reversal in the AERONET AOT trend percentiles is found over the USA, probably related to the AOT diurnal cycle and the frequency of wildfires.

  11. Estimated monthly percentile discharges at ungaged sites in the Upper Yellowstone River Basin in Montana

    USGS Publications Warehouse

    Parrett, Charles; Hull, J.A.

    1986-01-01

    Once-monthly streamflow measurements were used to estimate selected percentile discharges on flow-duration curves of monthly mean discharge for 40 ungaged stream sites in the upper Yellowstone River basin in Montana. The estimation technique was a modification of the concurrent-discharge method previously described and used by H.C. Riggs to estimate annual mean discharge. The modified technique is based on the relationship of various mean seasonal discharges to the required discharges on the flow-duration curves. The mean seasonal discharges are estimated from the monthly streamflow measurements, and the percentile discharges are calculated from regression equations. The regression equations, developed from streamflow record at nine gaging stations, indicated a significant log-linear relationship between mean seasonal discharge and various percentile discharges. The technique was tested at two discontinued streamflow-gaging stations; the differences between estimated monthly discharges and those determined from the discharge record ranged from -31 to +27 percent at one site and from -14 to +85 percent at the other. The estimates at one site were unbiased, and the estimates at the other site were consistently larger than the recorded values. Based on the test results, the probable average error of the technique was + or - 30 percent for the 21 sites measured during the first year of the program and + or - 50 percent for the 19 sites measured during the second year. (USGS)

  12. Percentile Distributions of Birth Weight according to Gestational Ages in Korea (2010-2012)

    PubMed Central

    2016-01-01

    The Pediatric Growth Chart (2007) is used as a standard reference to evaluate weight and height percentiles of Korean children and adolescents. Although several previous studies provided a useful reference range of newborn birth weight (BW) by gestational age (GA), the BW reference analyzed by sex and plurality is not currently available. Therefore, we aimed to establish a national reference range of neonatal BW percentiles considering GA, sex, and plurality of newborns in Korea. The raw data of all newborns (470,171 in 2010, 471,265 in 2011, and 484,550 in 2012) were analyzed. Using the Korean Statistical Information Service data (2010–2012), smoothed percentile curves (3rd–97th) by GA were created using the lambda-mu-sigma method after exclusion and the data were distinguished by all live births, singleton births, and multiple births. In the entire cohort, male newborns were heavier than female newborns and singletons were heavier than twins. As GA increased, the difference in BW between singleton and multiples increased. Compared to the previous data published 10 years ago in Korea, the BW of newborns 22–23 gestational weeks old was increased, whereas that of others was smaller. Other countries' data were also compared and showed differences in BW of both singleton and multiple newborns. We expect this updated data to be utilized as a reference to improve clinical assessments of newborn growth. PMID:27247504

  13. Percentile Distributions of Birth Weight according to Gestational Ages in Korea (2010-2012).

    PubMed

    Lee, Jin Kyoung; Jang, Hye Lim; Kang, Byung Ho; Lee, Kyung-Suk; Choi, Yong-Sung; Shim, Kye Shik; Lim, Jae Woo; Bae, Chong-Woo; Chung, Sung-Hoon

    2016-06-01

    The Pediatric Growth Chart (2007) is used as a standard reference to evaluate weight and height percentiles of Korean children and adolescents. Although several previous studies provided a useful reference range of newborn birth weight (BW) by gestational age (GA), the BW reference analyzed by sex and plurality is not currently available. Therefore, we aimed to establish a national reference range of neonatal BW percentiles considering GA, sex, and plurality of newborns in Korea. The raw data of all newborns (470,171 in 2010, 471,265 in 2011, and 484,550 in 2012) were analyzed. Using the Korean Statistical Information Service data (2010-2012), smoothed percentile curves (3(rd)-97(th)) by GA were created using the lambda-mu-sigma method after exclusion and the data were distinguished by all live births, singleton births, and multiple births. In the entire cohort, male newborns were heavier than female newborns and singletons were heavier than twins. As GA increased, the difference in BW between singleton and multiples increased. Compared to the previous data published 10 years ago in Korea, the BW of newborns 22-23 gestational weeks old was increased, whereas that of others was smaller. Other countries' data were also compared and showed differences in BW of both singleton and multiple newborns. We expect this updated data to be utilized as a reference to improve clinical assessments of newborn growth. PMID:27247504

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

    PubMed Central

    Lenz, Markus; Kolvenbach, Boris; Gygax, Benjamin; Moes, Suzette; Corvini, Philippe F. X.

    2011-01-01

    Selenium-reducing microorganisms produce elemental selenium nanoparticles with particular physicochemical properties due to an associated organic fraction. This study identified high-affinity proteins associated with such bionanominerals and with nonbiogenic elemental selenium. Proteins with an anticipated functional role in selenium reduction, such as a metalloid reductase, were found to be associated with nanoparticles formed by one selenium respirer, Sulfurospirillum barnesii. PMID:21602371

  15. Biomarkers of Selenium Status

    PubMed Central

    Combs, Gerald F.

    2015-01-01

    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 potential; and very high Se intakes can produce adverse effects. This hierarchy of biological activities calls for biomarkers informative at different levels of Se exposure. Some Se-biomarkers, such as the selenoproteins and particularly GPX3 and SEPP1, provide information about function directly and are of value in identifying nutritional Se deficiency and tracking responses of deficient individuals to Se-treatment. They are useful under conditions of Se intake within the range of regulated selenoprotein expression, e.g., for humans <55 μg/day and for animals <20 μg/kg diet. Other Se-biomarkers provide information indirectly through inferences based on Se levels of foods, tissues, urine or feces. They can indicate the likelihood of deficiency or adverse effects, but they do not provide direct evidence of either condition. Their value is in providing information about Se status over a wide range of Se intake, particularly from food forms. There is need for additional Se biomarkers particularly for assessing Se status in non-deficient individuals for whom the prospects of cancer risk reduction and adverse effects risk are the primary health considerations. This would include determining whether supranutritional intakes of Se may be required for maximal selenoprotein expression in immune surveillance cells. It would also include developing methods to determine low molecular weight Se-metabolites, i.e., selenoamino acids and methylated Se-metabolites, which to date have not been detectable in biological specimens. Recent analytical advances using tandem liquid chromatography-mass spectrometry suggest prospects for detecting these metabolites. PMID:25835046

  16. Establishing percentiles for junior tennis players based on physical fitness testing results.

    PubMed

    Roetert, E P; Piorkowski, P A; Woods, R B; Brown, S W

    1995-01-01

    An important aspect of this study was the establishment of a data base. A broad data base allows for data on certain parameters to be greatly expanded and will also enhance the use and interpretation of statistical methods. A longitudinal study of these variables may also assist in monitoring the players' progress over a period of time, and can provide a useful supplement to subjective coaching appraisals. The means and standard deviation for each test were calculated according to the USTA age and gender groups, that is, 12s, 14s, and 16s for each separate gender. Additionally, the mean and standard deviations for the ages, heights, and weights of each grouping were also calculated. Once the means and standard deviations were calculated, percentile tables were developed for each of the USTA groupings (by age and gender). The percentiles for each USTA test are presented in Appendix 1. A percentile is defined as the point on the distribution below which a given percentage of the scores is found. Percentiles can provide a norm-referenced interpretation of an individual score within a distribution that often consists of scores from a comparable group of individuals. Using the USTA protocol, players and coaches now have a set of normative data by which individual player's fitness scores may be compared with participants of the USTA Area Training Centers (See appendix 1). From the test results, coaches and players can determine which fitness areas need to be improved for athletes on an individual basis. Specific training programs can then be designed based on an athlete's fitness testing results. Proper interpretation of the USTA fitness testing data base results can lead to an easy way to determine the relative position of a given fitness score in the distribution, recognizing weaker areas for the purpose of injury prevention and performance enhancement. Each player can be given a profile detailing their percentile rank relative to other area training center

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

    SciTech Connect

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

    2009-06-04

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

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

    PubMed

    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. PMID:25747595

  19. Associations of Toenail Selenium Levels With Inflammatory Biomarkers of Fibrinogen, High-Sensitivity C-Reactive Protein, and Interleukin-6

    PubMed Central

    Xun, Pengcheng; Liu, Kiang; Steven Morris, J.; Daviglus, Martha L.; Stevens, June; Jacobs, David R.; He, Ka

    2010-01-01

    The authors examined the associations of toenail selenium levels with blood concentrations of fibrinogen, high-sensitivity C-reactive protein (hs-CRP), and interleukin-6 (IL-6) in an 18-year follow-up study comprising 4,032 Americans aged 20–32 years at baseline (1987) from the Coronary Artery Risk Development in Young Adults (CARDIA) Trace Element Study. Toenail samples were collected in 1987, and selenium concentrations were measured by means of instrumental neutron-activation analysis. Fibrinogen level was analyzed in 1990, 1992, and 2005; hs-CRP was assessed in 1992, 2000, and 2005; and IL-6 was measured in 2005. After adjustment for potential confounders, no statistically significant associations between toenail selenium levels and any of the 3 inflammatory biomarkers were documented. Comparing the highest quintile of toenail selenium level with the lowest, odds ratios for elevated levels of fibrinogen (>460 mg/mL), hs-CRP (>3 μg/mL), and IL-6 (>3.395 pg/mL, 80th percentile) were 1.03 (95% confidence interval (CI): 0.77, 1.38; P for trend = 0.76), 1.02 (95% CI: 0.83, 1.27; P for trend = 0.92), and 0.98 (95% CI: 0.71, 1.36; P for trend = 0.82), respectively. Gender, race/ethnicity, smoking status, and selenium supplementation did not appreciably modify these results. This study found no associations between toenail selenium and inflammation as measured by fibrinogen, hs-CRP, and IL-6. PMID:20219762

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Physical Fitness Percentiles of German Children Aged 9–12 Years: Findings from a Longitudinal Study

    PubMed Central

    Golle, Kathleen; Muehlbauer, Thomas; Wick, Ditmar; Granacher, Urs

    2015-01-01

    Background Generating percentile values is helpful for the identification of children with specific fitness characteristics (i.e., low or high fitness level) to set appropriate fitness goals (i.e., fitness/health promotion and/or long-term youth athlete development). Thus, the aim of this longitudinal study was to assess physical fitness development in healthy children aged 9–12 years and to compute sex- and age-specific percentile values. Methods Two-hundred and forty children (88 girls, 152 boys) participated in this study and were tested for their physical fitness. Physical fitness was assessed using the 50-m sprint test (i.e., speed), the 1-kg ball push test, the triple hop test (i.e., upper- and lower- extremity muscular power), the stand-and-reach test (i.e., flexibility), the star run test (i.e., agility), and the 9-min run test (i.e., endurance). Age- and sex-specific percentile values (i.e., P10 to P90) were generated using the Lambda, Mu, and Sigma method. Adjusted (for change in body weight, height, and baseline performance) age- and sex-differences as well as the interactions thereof were expressed by calculating effect sizes (Cohen’s d). Results Significant main effects of Age were detected for all physical fitness tests (d = 0.40–1.34), whereas significant main effects of Sex were found for upper-extremity muscular power (d = 0.55), flexibility (d = 0.81), agility (d = 0.44), and endurance (d = 0.32) only. Further, significant Sex by Age interactions were observed for upper-extremity muscular power (d = 0.36), flexibility (d = 0.61), and agility (d = 0.27) in favor of girls. Both, linear and curvilinear shaped curves were found for percentile values across the fitness tests. Accelerated (curvilinear) improvements were observed for upper-extremity muscular power (boys: 10–11 yrs; girls: 9–11 yrs), agility (boys: 9–10 yrs; girls: 9–11 yrs), and endurance (boys: 9–10 yrs; girls: 9–10 yrs). Tabulated percentiles for the 9-min run test

  3. A COMPARISON OF STUDENTS SCORING ABOVE THE EIGHTIETH PERCENTILE OR BELOW THE TWENTIETH PERCENTILE ON EITHER THE SCHOOL AND COLLEGE ABILITY TEST OR THE WATSON-GLASER TEST OF CRITICAL THINKING.

    ERIC Educational Resources Information Center

    CURRY, JOHN

    IN ORDER TO ESTABLISH THE FEASIBILITY OF A CUT-OFF SCORE FOR ENTRANCE INTO TEACHER EDUCATION PROGRAMS AT NORTH TEXAS STATE UNIVERSITY, SCORES OF 1,346 STUDENTS WHO EITHER PLACED ABOVE THE 80TH PERCENTILE (N-672) OR BELOW THE 20TH PERCENTILE (N-674) ON EITHER THE SCHOOL AND COLLEGE ABILITY TEST OR THE WATSON-GLASER TEST OF CRITICAL THINKING WERE…

  4. Selenium nanoparticles inhibit Staphylococcus aureus growth

    PubMed Central

    Tran, Phong A; Webster, Thomas J

    2011-01-01

    Staphylococcus aureus is a key bacterium commonly found in numerous infections. S. aureus infections are difficult to treat due to their biofilm formation and documented antibiotic resistance. While selenium has been used for a wide range of applications including anticancer applications, the effects of selenium nanoparticles on microorganisms remain largely unknown to date. The objective of this in vitro study was thus to examine the growth of S. aureus in the presence of selenium nanoparticles. Results of this study provided the first evidence of strongly inhibited growth of S. aureus in the presence of selenium nanoparticles after 3, 4, and 5 hours at 7.8, 15.5, and 31 μg/mL. The percentage of live bacteria also decreased in the presence of selenium nanoparticles. Therefore, this study suggests that selenium nanoparticles may be used to effectively prevent and treat S. aureus infections and thus should be further studied for such applications. PMID:21845045

  5. Recovering selenium from copper refinery slimes

    NASA Astrophysics Data System (ADS)

    Hyvärinen, Olli; Lindroos, Leo; Yllö, Erkki

    1989-07-01

    The selenium contained within copper refinery slimes may be recovered advantageously by roasting at about 600°C. While roasting in air is inefficient, roasting in a sulfating atmosphere enables practically complete selenium recovery. Based on laboratory tests, a new selenium recovery process was adopted at Outokumpu Copper Refinery. In this process, sulfation is achieved by feeding sulfur dioxide and oxygen into the roasting furnace.

  6. Selenium status of idiopathic infertile Nigerian males.

    PubMed

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

    2005-04-01

    Selenium concentration in the sera and seminal plasma of 60 infertile males (40 oligospermia and 20 azoospermia) and 40 males with proven evidence of fertility (normospermia; control group) were estimated using atomic absorption spectrophotometry. Results were correlated with spermatogram and hormonal levels in order to determine their relationship and significance in male infertility. The mean serum concentrations of selenium was found to be significantly increased in oligospermic compared to azoospermic subjects and controls (p < 0.01), whereas the seminal plasma level was significantly higher in azoospermic compared to oligospermic subjects and controls (p < 0.001). Thus, the ratio of serum selenium to seminal plasma selenium was 1: 1 in controls, 4: 1 in oligospermia, and 1: 2 in azoospermic subject.A significant inverse correlation was observed between serum selenium level and sperm count (p < 0.01). Similarly, seminal plasma selenium correlated with spermatozoa motility, viability, and morphology. Serum selenium level shows positive correlation with the serum testosterone level (p < 0.01). In conclusion, there appears to be a physiological balance in the distribution of selenium in serum and seminal plasma compartment of control males. A disturbance in this balance has a significant influence on spermatogenesis. Selenium appears to have a positive influence on Leydig cells, thus influencing the secretion of testosterone. PMID:15851828

  7. Selenium bioavailability with reference to human nutrition

    SciTech Connect

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

    1982-05-01

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

  8. Selenium levels in breads from Sakarya, Turkey.

    PubMed

    Gülfen, Mustafa

    2012-01-01

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

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

    PubMed Central

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

    1990-01-01

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

  10. Removal of selenium from contaminated waters

    SciTech Connect

    Gleason, K.J.; Yu, Jianhan; Wright, J.D.

    1995-12-01

    Selenium, an essential nutrient in minute quantities, is known to be toxic and is a suspected carcinogen at higher concentrations. The toxicity and teratogenicity of selenium to waterfowl present difficulties in disposing of selenium contaminated waters. Included in the U.S. EPA`s list of priority pollutants, selenium is presently the primary water treatment challenge for many West Coast petroleum refineries. Depending on the type of crude oil processed, selenium can be found in refinery process waters at levels up to 5 mg/L with flowrates approaching 1000 gallons per minute. Agricultural drainage waters emanating from irrigated farm lands in the seleniferous areas of the western United States are another major source of selenium contaminated waters. Because of the high mobility of some selenium compounds, they are easily leached from these soils by irrigation water. Within central California alone, there is a current need for the treatment of about 2 million gallons per day of selenium contaminated agricultural drainage water in concentrations approaching 0.5 mg/L. This paper will present an improved process for the removal of selenium from contaminated waters.

  11. How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food.

    PubMed

    Haug, Anna; Graham, Robin D; Christophersen, Olav A; Lyons, Graham H

    2007-12-01

    The world's rare selenium resources need to be managed carefully. Selenium is extracted as a by-product of copper mining and there are no deposits that can be mined for selenium alone. Selenium has unique properties as a semi-conductor, making it of special value to industry, but it is also an essential nutrient for humans and animals and may promote plant growth and quality. Selenium deficiency is regarded as a major health problem for 0.5 to 1 billion people worldwide, while an even larger number may consume less selenium than required for optimal protection against cancer, cardiovascular diseases and severe infectious diseases including HIV disease. Efficient recycling of selenium is difficult. Selenium is added in some commercial fertilizers, but only a small proportion is taken up by plants and much of the remainder is lost for future utilization. Large biofortification programmes with selenium added to commercial fertilizers may therefore be a fortification method that is too wasteful to be applied to large areas of our planet. Direct addition of selenium compounds to food (process fortification) can be undertaken by the food industry. If selenomethionine is added directly to food, however, oxidation due to heat processing needs to be avoided. New ways to biofortify food products are needed, and it is generally observed that there is less wastage if selenium is added late in the production chain rather than early. On these bases we have proposed adding selenium-enriched, sprouted cereal grain during food processing as an efficient way to introduce this nutrient into deficient diets. Selenium is a non-renewable resource. There is now an enormous wastage of selenium associated with large-scale mining and industrial processing. We recommend that this must be changed and that much of the selenium that is extracted should be stockpiled for use as a nutrient by future generations. PMID:18833333

  12. How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food

    PubMed Central

    Haug, Anna; Graham, Robin D.; Christophersen, Olav A.; Lyons, Graham H.

    2007-01-01

    The world's rare selenium resources need to be managed carefully. Selenium is extracted as a by-product of copper mining and there are no deposits that can be mined for selenium alone. Selenium has unique properties as a semi-conductor, making it of special value to industry, but it is also an essential nutrient for humans and animals and may promote plant growth and quality. Selenium deficiency is regarded as a major health problem for 0.5 to 1 billion people worldwide, while an even larger number may consume less selenium than required for optimal protection against cancer, cardiovascular diseases and severe infectious diseases including HIV disease. Efficient recycling of selenium is difficult. Selenium is added in some commercial fertilizers, but only a small proportion is taken up by plants and much of the remainder is lost for future utilization. Large biofortification programmes with selenium added to commercial fertilizers may therefore be a fortification method that is too wasteful to be applied to large areas of our planet. Direct addition of selenium compounds to food (process fortification) can be undertaken by the food industry. If selenomethionine is added directly to food, however, oxidation due to heat processing needs to be avoided. New ways to biofortify food products are needed, and it is generally observed that there is less wastage if selenium is added late in the production chain rather than early. On these bases we have proposed adding selenium-enriched, sprouted cereal grain during food processing as an efficient way to introduce this nutrient into deficient diets. Selenium is a non-renewable resource. There is now an enormous wastage of selenium associated with large-scale mining and industrial processing. We recommend that this must be changed and that much of the selenium that is extracted should be stockpiled for use as a nutrient by future generations. PMID:18833333

  13. Percentile-based Empirical Distribution Function Estimates for Performance Evaluation of Healthcare Providers

    PubMed Central

    Paddock, Susan M.; Louis, Thomas A.

    2010-01-01

    Summary Hierarchical models are widely-used to characterize the performance of individual healthcare providers. However, little attention has been devoted to system-wide performance evaluations, the goals of which include identifying extreme (e.g., top 10%) provider performance and developing statistical benchmarks to define high-quality care. Obtaining optimal estimates of these quantities requires estimating the empirical distribution function (EDF) of provider-specific parameters that generate the dataset under consideration. However, the difficulty of obtaining uncertainty bounds for a square-error loss minimizing EDF estimate has hindered its use in system-wide performance evaluations. We therefore develop and study a percentile-based EDF estimate for univariate provider-specific parameters. We compute order statistics of samples drawn from the posterior distribution of provider-specific parameters to obtain relevant uncertainty assessments of an EDF estimate and its features, such as thresholds and percentiles. We apply our method to data from the Medicare End Stage Renal Disease (ESRD) Program, a health insurance program for people with irreversible kidney failure. We highlight the risk of misclassifying providers as exceptionally good or poor performers when uncertainty in statistical benchmark estimates is ignored. Given the high stakes of performance evaluations, statistical benchmarks should be accompanied by precision estimates. PMID:21918583

  14. Ensemble hydrological prediction of streamflow percentile at ungauged basins in Pakistan

    NASA Astrophysics Data System (ADS)

    Waseem, Muhammad; Ajmal, Muhammad; Kim, Tae-Woong

    2015-06-01

    Streamflow records with sufficient spatial and temporal coverage at the site of interest are usually scarce in Pakistan. As an alternative, various regional methods have been frequently adopted to derive hydrological information, which in essence attempt to transfer hydrological information from gauged to ungauged catchments. In this study, a new concept of ensemble hydrological prediction (EHP) was introduced which is an improved regional method for hydrological prediction at ungauged sites. It was mainly based on the performance weights (triple-connection weights (TCW)) derived from Nash Sutcliffe efficiency (NSE) and hydrological variable (here percentiles) calculated from three traditional regional transfer methods (RTMs) with suitable modification (i.e., three-step drainage area ratio (DAR) method, inverse distance weighting (IDW) method, and three-step regional regression analysis (RRA)). The overall results indicated that the proposed EHP method was robust for estimating hydrological percentiles at ungauged sites as compared to traditional individual RTMs. The comparative study based on NSE, percent bias (PBIAS) and the relative error (RE) as performance criteria resulted that the EHP is a constructive alternative for hydrological prediction of ungauged basins.

  15. The role of selenium in cancer prevention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This elucidation of the role of selenium in health occurred over the last six decades. This involved selenium first being found to be a toxicant, followed only later by its recognition as an essential nutrient. This pathway of discovery led to fundamental discoveries in metabolic biochemistry, vir...

  16. 21 CFR 573.920 - Selenium.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Selenium. 573.920 Section 573.920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.920 Selenium. (a) Public Law...

  17. 21 CFR 573.920 - Selenium.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Selenium. 573.920 Section 573.920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.920 Selenium. (a) Public Law...

  18. 21 CFR 573.920 - Selenium.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Selenium. 573.920 Section 573.920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.920 Selenium. (a) Public Law...

  19. Changing selenium nutritional status of Chinese residents

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Selenium compounds activate early barriers of tumorigenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium chemoprevention by apoptosis has been well studied, but it is not clear whether selenium can activate early barriers of tumorigenesis, namely senescence and DNA damage response. To address this issue, we treated normal and cancerous cells with a gradient concentration of sodium selenite, me...

  1. State disparities in time trends of adolescent body mass index percentile and weight-related behaviors in the United States.

    PubMed

    Taber, Daniel R; Stevens, June; Poole, Charles; Maciejewski, Matthew L; Evenson, Kelly R; Ward, Dianne S

    2012-02-01

    Evidence is conflicting as to whether youth obesity prevalence has reached a plateau in the United States overall. Trends vary by state, and experts recommend exploring whether trends in weight-related behaviors are associated with changes in weight status trends. Thus, our objective was to estimate between-state variation in time trends of adolescent body mass index (BMI) percentile and weight-related behaviors from 2001 to 2007. A time series design combined cross-sectional Youth Risk Behavior Survey data from 272,044 adolescents in 29 states from 2001 to 2007. Self-reported height, weight, sports participation, physical education, television viewing, and daily consumption of 100% fruit juice, milk, and fruits and vegetables were collected. Linear mixed models estimated state variance in time trends of behaviors and BMI percentile. Across states, BMI percentile trends were consistent despite differences in behavioral trends. Boys experienced a modest linear increase in BMI percentile (ß = 0.18, 95% CI: 0.07, 0.30); girls experienced a non-linear increase, as the rate of increase declined over time from 1.02 units in 2001-2002 (95% CI: 0.68, 1.36) to 0.23 units in 2006-2007 (95% CI: -0.09, 0.56). States in which BMI percentile decreased experienced a greater decrease in TV viewing than states where BMI percentile increased. Otherwise, states with disparate BMI percentile trends did not differ with respect to behaviors. Future research should explore the role of other behaviors (e.g., soda consumption), measurement units (e.g., portion size), and societal trends (e.g., urban sprawl) on state and national adiposity trends. PMID:21773818

  2. Percentile Ranking and Citation Impact of a Large Cohort of NHLBI-funded Cardiovascular R01 Grants

    PubMed Central

    Danthi, Narasimhan; Wu, Colin O.; Shi, Peibei; Lauer, Michael

    2014-01-01

    Rationale Funding decisions for cardiovascular R01 grant applications at NHLBI largely hinge on percentile rankings. It is not known whether this approach enables the highest impact science. Objective To conduct an observational analysis of percentile rankings and bibliometric outcomes for a contemporary set of funded NHLBI cardiovascular R01 grants. Methods and results We identified 1492 investigator-initiated de novo R01 grant applications that were funded between 2001 and 2008, and followed their progress for linked publications and citations to those publications. Our co-primary endpoints were citations received per million dollars of funding, citations obtained within 2-years of publication, and 2-year citations for each grant’s maximally cited paper. In 7654 grant-years of funding that generated $3004 million of total NIH awards, the portfolio yielded 16,793 publications that appeared between 2001 and 2012 (median per grant 8, 25th and 75th percentiles 4 and 14, range 0 – 123), which received 2,224,255 citations (median per grant 1048, 25th and 75th percentiles 492 and 1,932, range 0 – 16,295). We found no association between percentile ranking and citation metrics; the absence of association persisted even after accounting for calendar time, grant duration, number of grants acknowledged per paper, number of authors per paper, early investigator status, human versus non-human focus, and institutional funding. An exploratory machine-learning analysis suggested that grants with the very best percentile rankings did yield more maximally cited papers. Conclusions In a large cohort of NHLBI-funded cardiovascular R01 grants, we were unable to find a monotonic association between better percentile ranking and higher scientific impact as assessed by citation metrics. PMID:24406983

  3. Surface functionalized selenium nanoparticles for biomedical applications.

    PubMed

    Chaudhary, Savita; Umar, Ahmad; Mehta, S K

    2014-10-01

    Selenium nanoparticles present an enhanced genetic actions and possess superior adsorptive capacity due to the interaction between the nanoparticles and NH, C=O, COO- and C-N groups of proteins. This review is focused on the biomedical applications of surafce funtionalized selenium nanoparticles. The engineering of exterior surface of the selenium nanoparticles has further emphasizing on the recent progresses in regulating monolayer structures for competent delivery of drugs and biomolecules. Crucial queries of transport, uptake, and clearance are discussed and illustrated through the prospects of selenium nanoparticles. The work presents an insight of how biomedical research can evolve with selenium nanoparticles and where we see the field is heading in the near future. PMID:25992427

  4. Development of a Three-Dimensional Finite Element Chest Model for the 5(th) Percentile Female.

    PubMed

    Kimpara, Hideyuki; Lee, Jong B; Yang, King H; King, Albert I; Iwamoto, Masami; Watanabe, Isao; Miki, Kazuo

    2005-11-01

    Several three-dimensional (3D) finite element (FE) models of the human body have been developed to elucidate injury mechanisms due to automotive crashes. However, these models are mainly focused on 50(th) percentile male. As a first step towards a better understanding of injury biomechanics in the small female, a 3D FE model of a 5(th) percentile female human chest (FEM-5F) has been developed and validated against experimental data obtained from two sets of frontal impact, one set of lateral impact, two sets of oblique impact and a series of ballistic impacts. Two previous FE models, a small female Total HUman Model for Safety (THUMS-AF05) occupant version 1.0Beta (Kimpara et al. 2002) and the Wayne State University Human Thoracic Model (WSUHTM, Wang 1995 and Shah et al. 2001) were integrated and modified for this model development. The model incorporated not only geometrical gender differences, such as location of the internal organs and structure of the bony skeleton, but also the biomechanical differences of the ribs due to gender. It includes a detailed description of the sternum, ribs, costal cartilage, thoracic spine, skin, superficial muscles, intercostal muscles, heart, lung, diaphragm, major blood vessels and simplified abdominal internal organs and has been validated against a series of six cadaveric experiments on the small female reported by Nahum et al. (1970), Kroell et al. (1974), Viano (1989), Talantikite et al. (1998) and Wilhelm (2003). Results predicted by the model were well-matched to these experimental data for a range of impact speeds and impactor masses. More research is needed in order to increase the accuracy of predicting rib fractures so that the mechanisms responsible for small female injury can be more clearly defined. PMID:17096277

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

    PubMed

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

    2016-03-01

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

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

    PubMed Central

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

    2012-01-01

    Background/objectives Significant changes have been reported in dietary habits and food availability in Iceland that would be expected to compromise selenium intake and status, especially among young people. These include substantial decreases in the consumption of fish and milk, as well as the selenium content of imported wheat. The aim of this study was to assess selenium in the diet and whole blood of adolescent girls, as well as define the most important foods contributing to intake and blood concentrations of selenium. Design The subjects were 96 randomly selected girls, aged 16–20, who answered a validated food frequency questionnaire (FFQ) for dietary assessment. Selenium intake from each food group was calculated in µg/day. Blood samples were collected for measurement of whole blood selenium. Results Mean dietary selenium was 51±25 µg/day. Milk/dairy products, including cheese, contributed 36±14% of total dietary selenium; fish 18±12%; and bread/cereal products 13±6%. Mean whole blood selenium was 117±12 µg/l (range 90–208); nearly 90% of subjects were above the optimal level of 100 µg/l. Fish and bread/cereal products were the only foods significantly correlated with selenium in blood (r=0.32; P=0.002 and r=0.22; P=0.04, respectively) while no correlation was found with milk and dairy products in spite of their greater contribution to total selenium intake. Conclusion In this population of Icelandic adolescent girls, selenium intake and status seem acceptable. Judging from associations between intake and blood levels, fish and cereals may be the most important contributors to blood selenium. PMID:22952457

  7. Selenium in Cattle: A Review.

    PubMed

    Mehdi, Youcef; Dufrasne, Isabelle

    2016-01-01

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

  8. Selenium in oncology: from chemistry to clinics.

    PubMed

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

    2009-01-01

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

  9. Dynamic Contrast-Enhanced MRI of Cervical Cancers: Temporal Percentile Screening of Contrast Enhancement Identifies Parameters for Prediction of Chemoradioresistance

    SciTech Connect

    Andersen, Erlend K.F.; Hole, Knut Hakon; Lund, Kjersti V.; Sundfor, Kolbein; Kristensen, Gunnar B.; Lyng, Heidi; Malinen, Eirik

    2012-03-01

    Purpose: To systematically screen the tumor contrast enhancement of locally advanced cervical cancers to assess the prognostic value of two descriptive parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Methods and Materials: This study included a prospectively collected cohort of 81 patients who underwent DCE-MRI with gadopentetate dimeglumine before chemoradiotherapy. The following descriptive DCE-MRI parameters were extracted voxel by voxel and presented as histograms for each time point in the dynamic series: normalized relative signal increase (nRSI) and normalized area under the curve (nAUC). The first to 100th percentiles of the histograms were included in a log-rank survival test, resulting in p value and relative risk maps of all percentile-time intervals for each DCE-MRI parameter. The maps were used to evaluate the robustness of the individual percentile-time pairs and to construct prognostic parameters. Clinical endpoints were locoregional control and progression-free survival. The study was approved by the institutional ethics committee. Results: The p value maps of nRSI and nAUC showed a large continuous region of percentile-time pairs that were significantly associated with locoregional control (p < 0.05). These parameters had prognostic impact independent of tumor stage, volume, and lymph node status on multivariate analysis. Only a small percentile-time interval of nRSI was associated with progression-free survival. Conclusions: The percentile-time screening identified DCE-MRI parameters that predict long-term locoregional control after chemoradiotherapy of cervical cancer.

  10. Selenium uptake by sulfur-accumulating bacteria

    NASA Astrophysics Data System (ADS)

    Nelson, Douglas C.; Casey, William H.; Sison, Jennette D.; Mack, E. Erin; Ahmad, Azeem; Pollack, Jeffrey S.

    1996-09-01

    Selenium is a trace metal in many rock-forming minerals but is a major environmental contaminant worldwide. Uptake of selenium by S-accumulating bacteria was examined in both pure cultures of Chromatium vinosum and in co-culture with Desulfovibrio desulfuricans. We used dual cultures including these bacteria to concentrate selenium into intracellular globules. The bacterium D. desulfuricans reduces sulfate [SO 42- (aq)] to sulfide [H 2S(aq)] and also reduces selenate [SeO 42- (aq)] to selenide [H 2Se (aq)]. Once reduced, sulfide is enzymatically oxidized and formed into intracellular globules by C. vinosum. We found that the selenium also forms an intercellular solid but the reaction is thermodynamically driven and proceeds by reducing S° (s) with H 2Se(aq). Relative to the initial molar ratio of selenate and sulfate in the medium, selenium is concentrated 4.5 to 32-fold in the globules. Because solid selenium is so much more stable than sulfur at growth conditions, other S-depositing bacteria, such as Beggiatoa and Chlorobium, should also concentrate selenium via this reaction, providing a strategy for eliminating contamination or for concentrating low natural levels into a usable form.

  11. Decreased selenium levels in acute myocardial infarction

    SciTech Connect

    Kok, F.J.; Hofman, A.; Witteman, J.C.M.; de Bruijn, A.M.; Kruyssen, D.H.C.M.; de Bruin, M.; Valkenburg, H.A. )

    1989-02-24

    To study the association between selenium status and the risk of myocardial infarction, the authors compared plasma, erythrocyte, and toenail selenium levels and the activity of erythrocyte glutathione peroxidase among 84 patients with acute myocardial infarction and 84 population controls. Mean concentrations of all selenium measurements were lower in cases than controls. The differences were statistically significant, except for the plasma selenium level. A positive trend in the risk of acute myocardial infarction from high to low toenail selenium levels was observed, which persisted after adjustment for other risk factors for myocardial infarction. In contrast, erythrocyte glutathione peroxidase activity was significantly higher in cases than controls. Because toenail selenium level reflects blood levels up to one year before sampling, these findings suggest that a low selenium status was present before the infarction and, thus, may be of etiologic relevance. The higher glutathione peroxidase activity in the cases may be interpreted as a defense against increased oxidant stress either preceding or following the acute event.

  12. Revised reference values for selenium intake.

    PubMed

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

    2015-10-01

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

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

    USGS Publications Warehouse

    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.

  14. Selenium content of game meat

    SciTech Connect

    Medeiros, L.C.; Belden, R.P. Univ. of Wyoming, Laramie )

    1991-03-11

    Selenium (Se) content of elk, deer, bison and beef were measured and compared. Samples were obtained from animals grazed on soil known to contain high, but variable amounts of Se. Beef were feedlot grazed and elk, deer, and bison were from captive or semi-captive herds. Selenium content was determined by graphite furnace after high pressure wet microwave digestion of samples. Deer and bison contained more Se than elk or beef. On a dry weight basis, deer contained more Se than bison. Game species contained more Se than beef. Within samples from male elk and deer and elk and bison of both genders, there were interactions between specie and muscle effects. Muscle and gender did not significantly influence Se content. The animals from which these samples were taken were supplemented with feeds grown on high Se containing soils, which was reflected in all values. Se values were twofold higher than those previously reported for meat. Those consuming large quantities of game from areas with high Se soil may need to monitor Se intake to avoid consuming excessive quantities.

  15. Selenium and Methionine Sulfoxide Reduction.

    PubMed

    Gladyshev, Vadim N

    2014-10-01

    Selenium is an essential trace element because it is present in proteins in the form of selenocysteine residue. Functionally characterized selenoproteins are oxidoreductases. Selenoprotein methionine-R-sulfoxide reductase B1 (MsrB1) is a repair enzyme that reduces ROS-oxidized methionine residues in proteins. Here, we explored a possibility that reversible methionine oxidation is also a mechanism that regulates protein function. We found that MsrB1, together with Mical proteins, regulated mammalian actin assembly via stereospecific methionine oxidation and reduction in a reversible, site-specific manner. Two methionine residues in actin were specifically converted to methionine-R-sulfoxide by Mical1 and Mical2 and reduced back to methionine by MsrB1, supporting actin disassembly and assembly, respectively. Macrophages utilized this redox control during cellular activation by stimulating MsrB1 expression and activity. Thus, we identified the regulatory role of MsrB1 as a Mical antagonist in orchestrating actin dynamics and macrophage function. More generally, our study showed that proteins can be regulated by reversible site-specific methionine-R-sulfoxidation and that selenium is involved in this regulation by being a catalytic component of MsrB1. PMID:26461418

  16. Selenium accumulation and loss in mallard eggs

    SciTech Connect

    Heinz, G.H. )

    1993-04-01

    Five female mallards (Anas platyhynchos) that had just started egg laying were first fed a diet containing 15 ppm selenium in the form of selenomethionine for 20 d and then an untreated diet for 20 d. Selenium levels in eggs peaked (to about 13-20 ppm) in about two weeks on the treated diet and leveled off at a low level (< 5 ppm) after about 10 d back on the untreated diet. Selenium levels in egg whites responded faster than levels in yolks to the females' consumption of treated and untreated diets.

  17. Renal changes in selenium-exposed fish

    SciTech Connect

    Sorensen, E.M.; Harlan, C.W.; Bell, J.S.

    1982-06-01

    A group of green sunfish was collected from a selenium-rich lake and compared with a similar group collected from a control lake upstream in the same drainage system in east Texas. Since the level of selenium in kidneys of these fish was relatively high (averaging 11 ppm on a fresh weight basis), histopathological and ultrastructural data were collected. Kidneys from fish from the selenium-rich lake showed proliferative glomerulonephritis and hematuria as well as vacuolation and necrosis of cells of the convoluted tubules.

  18. Selenium isotope geochemistry: A new approach to characterizing the environmental chemistry of selenium. Final report

    SciTech Connect

    Volpe, A.M.; Esser, B.K.

    1997-02-05

    High levels of selenium in the environment will be a prominent water quality issue in the western United States for many years. Selenium accumulation is linked to increased rates of death and deformity in migratory birds, blind staggers in livestock, and selenosis in humans. In California, agricultural drain waters and oil refinery effluent contribute to high selenium content in the San Joaquin Valley and the San Francisco Bay. The importance of these industries to California`s economy precludes simple abatement, while the complexity of selenium cycling precludes simple remediation. The purpose of this project is to measure variations in the isotopic composition of selenium in water and soil samples caused by natural processes and to show, for the first time, the value of isotopic measurements in characterizing selenium pollution. The research seeks to identify sources of selenium pollution, determine processes in the selenium cycle, and support selenium remediation studies. The project required the successful integration of three components: (1) appropriate sampling a field setting showing Se enrichment and possibly isotopic fractionation, (2) analytical chemical methods for isolating and purifying the various species of Se in waters and sediment, and (3) mass spectroscopic instrumentation for high precision isotope abundance measurements.

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

    PubMed

    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. PMID:23079485

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    SciTech Connect

    Jenkins, K.J.; Hidiroglou, M.

    1986-07-01

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

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

    PubMed

    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

  3. Serum selenium concentrations in rheumatoid arthritis.

    PubMed Central

    O'Dell, J R; Lemley-Gillespie, S; Palmer, W R; Weaver, A L; Moore, G F; Klassen, L W

    1991-01-01

    Selenium is a trace element and an essential part of the enzyme glutathione peroxidase, which protects cells from oxidative damage. Selenium has been shown to have antiproliferative, anti-inflammatory, antiviral, and immune altering effects. Serum selenium concentrations in 101 patients with seropositive rheumatoid arthritis were found to be significantly lower than those in 29 normal, healthy controls (mean (SD) 148 (42) v 160 (25) micrograms/l) and also lower than those in eight patients with fibrositis (148 (42) v 166 (25) micrograms/l). It is speculated that serum selenium concentrations may modulate the effect of viral or other infections in subjects with the appropriate genetic background and in this way enhance the development or progression of rheumatoid arthritis. PMID:2059080

  4. Biofortification and phytoremediation of selenium in China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  5. Review of selenium and prostate cancer prevention.

    PubMed

    Yang, Lei; Pascal, Mouracade; Wu, Xiao-Hou

    2013-01-01

    Prostate cancer is the most common malignancy in men in the United States. Surgery or radiation are sometimes unsatisfactory treatments because of the complications such as incontinence or erectile dysfunction. Selenium was found to be effective to prevent prostate cancer in the Nutritional Prevention of Cancer Trial (NPC), which motivated two other clinical trials: the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and a Phase III trial of selenium to prevent prostate cancer in men with high-grade prostatic intraepithelial neoplasia. However, these two trials failed to confirm the results of the NPC trial and indicated that the selenium may not be preventive of prostate cancer. In this article we review the three clinical trials and discuss some different points which might be potential factors underlying variation in results obtained. PMID:23725109

  6. Analysis of the Stability of Teacher-Level Growth Scores from the Student Growth Percentile Model. REL 2016-104

    ERIC Educational Resources Information Center

    Lash, Andrea; Makkonen, Reino; Tran, Loan; Huang, Min

    2016-01-01

    This study, undertaken at the request of the Nevada Department of Education, examined the stability over years of teacher-level growth scores from the Student Growth Percentile (SGP) model, which many states and districts have selected as a measure of effectiveness in their teacher evaluation systems. The authors conducted a generalizability study…

  7. Standard Errors of Equating for the Percentile Rank-Based Equipercentile Equating with Log-Linear Presmoothing

    ERIC Educational Resources Information Center

    Wang, Tianyou

    2009-01-01

    Holland and colleagues derived a formula for analytical standard error of equating using the delta-method for the kernel equating method. Extending their derivation, this article derives an analytical standard error of equating procedure for the conventional percentile rank-based equipercentile equating with log-linear smoothing. This procedure is…

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

    SciTech Connect

    Zhang Jinsong Wang Huali; Yu Hanqing

    2007-10-01

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

  9. Selenium deficiency mitigates hypothyroxinemia in iodine-deficient subjects.

    PubMed

    Vanderpas, J B; Contempré, B; Duale, N L; Deckx, H; Bebe, N; Longombé, A O; Thilly, C H; Diplock, A T; Dumont, J E

    1993-02-01

    Studies were performed to assess the role of combined selenium and iodine deficiency in the etiology of endemic myxedematous cretinism in a population in Zaire. One effect of selenium deficiency may be to lower glutathione peroxidase activity in the thyroid gland, thus allowing hydrogen peroxide produced during thyroid hormone synthesis to be cytotoxic. In selenium-and-iodine-deficient humans, selenium supplementation may aggravate hypothyroidism by stimulating thyroxin metabolism by the selenoenzyme type I iodothyronine 5'-deiodinase. Selenium supplementation is thus not indicated without iodine or thyroid hormone supplementation in cases of combined selenium and iodine deficiencies. PMID:8427203

  10. [Selenium. Its physiologic and clinical importance].

    PubMed

    da Silva, A P

    1993-07-01

    Since its discovery in 1817, Selenium has had great biological importance as a key element of cellular protection and in its absence of pathological symptoms. In this revised work, historical aspects of selenium are considered, its characteristics, properties and source as well as its nutritional value, metabolism, physiopathological and biochemical function in humans and finally its future therapeutical application in humans and animals considering some of the traditional ways of treatment. PMID:8379356

  11. Production of selenium-72 and arsenic-72

    DOEpatents

    Phillips, Dennis R.

    1995-01-01

    Methods and apparatus 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.

  12. Production of selenium-72 and arsenic-72

    DOEpatents

    Phillips, Dennis R.

    1994-01-01

    Methods and apparatus 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.

  13. Production of selenium-72 and arsenic-72

    DOEpatents

    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.

  14. Validation of the 5th and 95th Percentile Hybrid III Anthropomorphic Test Device Finite Element Model

    NASA Technical Reports Server (NTRS)

    Lawrence, C.; Somers, J. T.; Baldwin, M. A.; Wells, J. A.; Newby, N.; Currie, N. J.

    2014-01-01

    NASA spacecraft design requirements for occupant protection are a combination of the Brinkley criteria and injury metrics extracted from anthropomorphic test devices (ATD's). For the ATD injury metrics, the requirements specify the use of the 5th percentile female Hybrid III and the 95th percentile male Hybrid III. Furthermore, each of these ATD's is required to be fitted with an articulating pelvis and a straight spine. The articulating pelvis is necessary for the ATD to fit into spacecraft seats, while the straight spine is required as injury metrics for vertical accelerations are better defined for this configuration. The requirements require that physical testing be performed with both ATD's to demonstrate compliance. Before compliance testing can be conducted, extensive modeling and simulation are required to determine appropriate test conditions, simulate conditions not feasible for testing, and assess design features to better ensure compliance testing is successful. While finite element (FE) models are currently available for many of the physical ATD's, currently there are no complete models for either the 5th percentile female or the 95th percentile male Hybrid III with a straight spine and articulating pelvis. The purpose of this work is to assess the accuracy of the existing Livermore Software Technology Corporation's FE models of the 5th and 95th percentile ATD's. To perform this assessment, a series of tests will be performed at Wright Patterson Air Force Research Lab using their horizontal impact accelerator sled test facility. The ATD's will be placed in the Orion seat with a modified-advanced-crew-escape-system (MACES) pressure suit and helmet, and driven with loadings similar to what is expected for the actual Orion vehicle during landing, launch abort, and chute deployment. Test data will be compared to analytical predictions and modelling uncertainty factors will be determined for each injury metric. Additionally, the test data will be used to

  15. The Association of Weight Percentile and Motor Vehicle Crash Injury Among 3 to 8 Year Old Children

    PubMed Central

    Zonfrillo, Mark R.; Nelson, Kyle A.; Durbin, Dennis R.; Kallan, Michael J.

    2010-01-01

    The use of age-appropriate child restraint systems significantly reduces injury and death associated with motor vehicle crashes (MVCs). Pediatric obesity has become a global epidemic. Although recent evidence suggests a possible association between pediatric obesity and MVC-related injury, there are potential misclassifications of body mass index from under-estimated height in younger children. Given this limitation, age- and sex-specific weight percentiles can be used as a proxy of weight status. The specific aim of this study was to determine the association between weight percentile and the risk of significant injury for children 3–8 years in MVCs. This was a cross-sectional study of children aged 3–8 years in MVCs in 16 US states, with data collected via insurance claims records and a telephone survey from 12/1/98–11/30/07. Parent-reported injuries with an abbreviated Injury Scale (AIS) score of 2+ indicated a clinically significant injury. Age- and sex-specific weight percentiles were calculated using pediatric norms. The study sample included 9,327 children aged 3–8 years (weighted to represent 157,878 children), of which 0.96% sustained clinically significant injuries. There was no association between weight percentiles and overall injury when adjusting for restraint type (p=0.71). However, increasing weight percentiles were associated with lower extremity injuries at a level that approached significance (p=0.053). Further research is necessary to describe mechanisms for weight-related differences in injury risk. Parents should continue to properly restrain their children in accordance with published guidelines. PMID:21050602

  16. Selenium in Gluten-free Products.

    PubMed

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

    2015-06-01

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

  17. Anticipated soil selenium concentrations at Kesterson Reservoir

    SciTech Connect

    Benson, S.M.; Tokunaga, T.K.; Zawislanski, P.

    1992-10-01

    Temporal trends from soil monitoring data collected at Kesterson Reservoir have been reviewed to shed light on anticipated concentrations of total and water-extractable selenium in surface and subsurface soils. Based on these data, a mass balance model for selenium has been developed and employed to evaluate the rate of leaching, remobilization and volatilization that has occurred since the Reservoir was dried out in 1987. Results from a series of calibration runs were then extrapolated 25 years in the future to forecast the evolution and redistribution of selenium within the soil profile. Projected water-extractable selenium concentrations within the 0.15 to 1 m depth interval were then used to drive a food-chain based risk-assessment model described in a separate report (CH2M Hill, 1992). Inventories of water-extractable selenium in the root zone increased in 4 of the 5 scenarios investigated. However, predicted values for the average concentration of water-extractable selenium in the root zone fall within the range of values observed at Kesterson today. Consequences of these projected increases on wildlife residing in and around Kesterson are addressed in CH2M Hill (1992).

  18. Biological activity of selenium: Revisited.

    PubMed

    Wrobel, Jagoda K; Power, Ronan; Toborek, Michal

    2016-02-01

    Selenium (Se) is an essential micronutrient that exerts multiple and complex effects on human health. Se is essential for human well-being largely due to its potent antioxidant, anti-inflammatory, and antiviral properties. The physiological functions of Se are carried out by selenoproteins, in which Se is specifically incorporated as the amino acid, selenocysteine. Importantly, both beneficial and toxic effects of Se have been reported suggesting that the mode of action of Se is strictly chemical form and concentration dependent. Additionally, there is a relatively narrow window between Se deficiency and toxicity and growing evidence suggests that Se health effects depend greatly on the baseline level of this micronutrient. Thus, Se supplementation is not an easy task and requires an individualized approach. It is essential that we continue to explore and better characterize Se containing compounds and mechanisms of action, which could be crucial for disease prevention and treatment. PMID:26714931

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    DOEpatents

    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.

  1. Updates on clinical studies of selenium supplementation in radiotherapy

    PubMed Central

    2014-01-01

    To establish guidelines for the selenium supplementation in radiotherapy we assessed the benefits and risks of selenium supplementation in radiotherapy. Clinical studies on the use of selenium in radiotherapy were searched in the PubMed electronic database in January 2013. Sixteen clinical studies were identified among the 167 articles selected in the initial search. Ten articles were observational studies, and the other 6 articles reported studies on the effects of selenium supplementation in patients with cancer who underwent radiotherapy. The studies were conducted worldwide including European, American and Asian countries between 1987 and 2012. Plasma, serum or whole blood selenium levels were common parameters used to assess the effects of radiotherapy and the selenium supplementation status. Selenium supplementation improved the general conditions of the patients, improved their quality of life and reduced the side effects of radiotherapy. At the dose of selenium used in these studies (200–500 μg/day), selenium supplementation did not reduce the effectiveness of radiotherapy, and no toxicities were reported. Selenium supplementation may offer specific benefits for several types of cancer patients who undergo radiotherapy. Because high-dose selenium and long-term supplementation may be unsafe due to selenium toxicity, more evidence-based information and additional research are needed to ensure the therapeutic benefits of selenium supplementation. PMID:24885670

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

    PubMed

    Yan, Lin; Johnson, LuAnn K

    2011-06-01

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

  3. Electrochemical behavior of chemically synthesized selenium thin film.

    PubMed

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

    2016-05-01

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

  4. Geochemistry of selenium in a coastal salt marsh

    SciTech Connect

    Velinsky, D.J.; Cutter, G.A. )

    1991-01-01

    The cycling of sedimentary selenium was examined over a one-year period in the Great Marsh, Delaware (USA). While total selenium and elemental selenium decrease with depth in the sediments at similar rates, Se(IV + VI) exhibits pronounced seasonality related to the redox conditions of the marsh. Porewater selenium reflects the diagenetic cycling of Se(IV + VI) in the sediments and suggests that a partial remobilization of sedimentary selenium occurs when the upper sediments become oxidizing. Diagenetic and mass-balance models indicate that the major sources of selenium to the marsh are creek waters and atmospheric deposition, while total selenium may be removed from the sediments via the flux of volatile selenium compounds.

  5. Acute selenium toxicosis in polo ponies.

    PubMed

    Desta, Belainesh; Maldonado, Gizela; Reid, Herman; Puschner, Birgit; Maxwell, James; Agasan, Alice; Humphreys, Leigh; Holt, Thomas

    2011-05-01

    Just prior to an international polo event, 21 horses from one team exhibited clinical signs of central nervous system disturbance, hyperexcitability, sweating, ataxia, tachycardia, dyspnea, pyrexia, and rapid death. The suspected cause of this peracute onset of illness and death included intentional contamination of feed or iatrogenic administration of performance-enhancing drugs resulting in a severe adverse reaction. Six horses were submitted to the Bronson Animal Disease Diagnostic Laboratory for necropsy and toxicological examination. The clinical signs and sudden death, the similarity to earlier work by the lead author of selenium toxicosis in calves, as well as published reports, prompted investigators to focus on selenium testing. Sixty-four hours following receipt, the laboratory detected toxic selenium concentrations in the tissues of these animals. Following further investigation of the case by regulatory officials, it was determined that all affected horses had received an intravenous injection of a compounded "vitamin/mineral" supplement just prior to the onset of signs. The compounded supplement contained toxic levels of selenium. The present report illustrates the in-depth laboratory investigation of the cause of acute death in 6 polo ponies due to selenium toxicosis. In addition to solving this high profile case, the toxic levels of selenium found in livers (6.13 ± 0.31 mg/kg wet weight), kidneys (6.25 ± 0.3 mg/kg wet weight), and sera (1.50 ± 0.11 µg/ml) of these affected animals may provide important diagnostic criteria for future interpretations of selenium concentrations in tissues of horses. PMID:21908304

  6. Avoidance of selenium-treated food by mallards

    USGS Publications Warehouse

    Heinz, G.H.; Sanderson, C.J.

    1990-01-01

    Adult, male mallards (Anas platyrhynchos) were given a choice between a control diet and a diet containing 5, 10 or 20 ppm selenium as selenomethionine dissolved in water and mixed into the diet. At 10 and 20 ppm, selenium-treated diets were avoided. Avoidance appeared to be caused by a conditioned response, probably to illness caused by the selenium and not to an aversion to the taste of the selenium.

  7. Selenium transformation in coal mine spoils. Quarterly report

    SciTech Connect

    Atalay, A.; Koll, K.J.

    1990-09-01

    The objective of this part of the study is to investigate the oxidation-reduction (redox) environment that favor the release of selenium from coal mine spoils. It is anticipated that the study will help answer critical questions as to the form, solubility, and mobility of selenium from the spoil site to the surrounding environment. This investigation will evaluate the conditions which favor the speciation of selenium from coal mine spoils as affected by changes in the oxidation states of selenium.

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

    PubMed Central

    Freitas, Renata Germano B. O. N.; Nogueira, Roberto José N.; Antonio, Maria Ângela R. G. M.; Barros-Filho, Antonio de Azevedo; Hessel, Gabriel

    2014-01-01

    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. PMID:24676200

  9. Selenium toxicosis in a flock of Katahdin hair sheep.

    PubMed Central

    Smith, B I; Donovan, G A; Rae, D O

    1999-01-01

    Selenium supplementation by injection is a common practice. Acute toxicosis from dosaging errors may occur. In this report, 23 of 56 ewes and all 24 lambs injected with selenium died. Tissue, whole blood, and serum concentrations aided in the diagnosis. Caution should be taken when supplementing selenium by injection. Images Figure 1. PMID:10086221

  10. 21 CFR 520.2100 - Selenium, vitamin E capsules.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Selenium, vitamin E capsules. 520.2100 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.2100 Selenium, vitamin... to 1 milligram of selenium) and 56.2 milligrams of vitamin E (68 I.U.) (as d-alpha tocopheryl...

  11. 21 CFR 520.2100 - Selenium, vitamin E capsules.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Selenium, vitamin E capsules. 520.2100 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.2100 Selenium, vitamin... to 1 milligram of selenium) and 56.2 milligrams of vitamin E (68 I.U.) (as d-alpha tocopheryl...

  12. 21 CFR 524.2101 - Selenium disulfide suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Selenium disulfide suspension. 524.2101 Section... § 524.2101 Selenium disulfide suspension. (a) Specifications. The product contains 0.9-percent weight in weight (w/w) selenium disulfide (1-percent weight in volume (w/v)). (b) Sponsors. See Nos. 000061,...

  13. 21 CFR 524.2101 - Selenium disulfide suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Selenium disulfide suspension. 524.2101 Section... § 524.2101 Selenium disulfide suspension. (a) Specifications. The product contains 0.9-percent weight in weight (w/w) selenium disulfide (1-percent weight in volume (w/v)). (b) Sponsors. See Nos. 000061,...

  14. 21 CFR 520.2100 - Selenium, vitamin E capsules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Selenium, vitamin E capsules. 520.2100 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.2100 Selenium, vitamin... to 1 milligram of selenium) and 56.2 milligrams of vitamin E (68 I.U.) (as d-alpha tocopheryl...

  15. 21 CFR 520.2100 - Selenium, vitamin E capsules.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Selenium, vitamin E capsules. 520.2100 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.2100 Selenium, vitamin... to 1 milligram of selenium) and 56.2 milligrams of vitamin E (68 I.U.) (as d-alpha tocopheryl...

  16. 21 CFR 524.2101 - Selenium disulfide suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Selenium disulfide suspension. 524.2101 Section... § 524.2101 Selenium disulfide suspension. (a) Specifications. The product contains 0.9-percent weight in weight (w/w) selenium disulfide (1-percent weight in volume (w/v)). (b) Sponsors. See Nos. 000061,...

  17. 21 CFR 522.2100 - Selenium, vitamin E injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Selenium, vitamin E injection. 522.2100 Section... § 522.2100 Selenium, vitamin E injection. (a)(1) Specifications. The drug is an emulsion containing in each milliliter, 5.48 milligrams sodium selenite (equivalent to 2.5 milligrams selenium), 50...

  18. 21 CFR 524.2101 - Selenium disulfide suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Selenium disulfide suspension. 524.2101 Section... § 524.2101 Selenium disulfide suspension. (a) Specifications. The product contains 0.9-percent weight in weight (w/w) selenium disulfide (1-percent weight in volume (w/v)). (b) Sponsors. See Nos. 000061,...

  19. 21 CFR 522.2100 - Selenium, vitamin E injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Selenium, vitamin E injection. 522.2100 Section... § 522.2100 Selenium, vitamin E injection. (a)(1) Specifications. The drug is an emulsion containing in each milliliter, 5.48 milligrams sodium selenite (equivalent to 2.5 milligrams selenium), 50...

  20. 21 CFR 520.2100 - Selenium, vitamin E capsules.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Selenium, vitamin E capsules. 520.2100 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.2100 Selenium, vitamin... to 1 milligram of selenium) and 56.2 milligrams of vitamin E (68 I.U.) (as d-alpha tocopheryl...

  1. 21 CFR 522.2100 - Selenium, vitamin E injection.

    Code of Federal Regulations, 2010 CFR

    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 each milliliter, 5.48 milligrams sodium selenite (equivalent to 2.5 milligrams selenium), 50...

  2. 21 CFR 522.2100 - Selenium, vitamin E injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Selenium, vitamin E injection. 522.2100 Section... § 522.2100 Selenium, vitamin E injection. (a)(1) Specifications. The drug is an emulsion containing in each milliliter, 5.48 milligrams sodium selenite (equivalent to 2.5 milligrams selenium), 50...

  3. 21 CFR 524.2101 - Selenium disulfide suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Selenium disulfide suspension. 524.2101 Section... § 524.2101 Selenium disulfide suspension. (a) Specifications. The product contains 0.9-percent weight in weight (w/w) selenium disulfide (1-percent weight in volume (w/v)). (b) Sponsors. See Nos. 000061,...

  4. Percentile Values for Running Sprint Field Tests in Children Ages 6-17 Years: Influence of Weight Status

    ERIC Educational Resources Information Center

    Castro-Pinero, Jose; Gonzalez-Montesinos, Jose Luis; Keating, Xiaofen D.; Mora, Jesus; Sjostrom, Michael; Ruiz, Jonatan R.

    2010-01-01

    The aim of this study was to provide percentile values for six different sprint tests in 2,708 Spanish children (1,234 girls) ages 6-17.9 years. We also examined the influence of weight status on sprint performance across age groups, with a focus on underweight and obese groups. We used the 20-m, 30-m, and 50-m running sprint standing start and…

  5. Dual functional selenium-substituted hydroxyapatite.

    PubMed

    Wang, Yanhua; Ma, Jun; Zhou, Lei; Chen, Jin; Liu, Yonghui; Qiu, Zhiye; Zhang, Shengmin

    2012-06-01

    Hydroxyapatite (HA) doped with trace elements has attracted much attention recently owing to its excellent biological functions. Herein, we use a facile co-precipitation method to incorporate selenium into HA by adding sodium selenite during synthesis. The obtained selenium-substituted HA products are needle-like nanoparticles which have  size and crystallinity that are similar to those of the pure HA nanoparticles (HANs) when the selenium content is low. HANs are found to have the ability to induce the apoptosis of osteosarcoma cells, and the anti-tumour effects are enhanced after incorporation of selenium. Meanwhile, the nanoparticles can also support the growth of bone marrow stem cells. Furthermore, the flow cytometric results indicate that the apoptosis induction of osteosarcoma cells is caused by the increased reactive oxygen species and decreased mitochondrial membrane potential. These results show that the selenium-substituted HANs are potentially promising bone graft materials in osteosarcoma treatment due to their dual functions of supporting normal cell growth and inducing tumour cell apoptosis. PMID:23741613

  6. Selenium in Camel – A Review

    PubMed Central

    Faye, Bernard; Seboussi, Rabiha

    2009-01-01

    Requirements for trace minerals in camels, particularly selenium, are not well-known. Selenium supplementation using a pharmaceutical form or commercial mineral mixture is common practice in camels to address the cardiomyopathy often attributed to selenium deficiency. This supplementation is often empirical and based on estimated needs for cattle. Nowadays the use of selenium in animal foodstuffs is commonplace and further investigation of its metabolism (ingestion, dynamic of storage-destocking, excretion) in camels is warranted. The present review aimed to synthesize all the experimental research (comparative selenium status in cow and camel, response to different levels of supplementation at different physiological stages, excretion maternal transfer, experimental toxicosis) and field observations (deficiency, supplementation practices) undertaken in camels. The results underline the particularity of the unique metabolic profile of the camel and lead to practical recommendations for supplementation in camels, highlighting its relative sensitivity to excess Se intake at lower levels than in cattle. The maximal tolerable dose is 8 mg and the recommended doses range from 2 to 4 mg. PMID:22253966

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

    PubMed Central

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  9. Spectrochemical method for the determination of selenium

    USGS Publications Warehouse

    Waring, C.L.; Worthing, H.W.; Hazel, K.V.

    1958-01-01

    Selenium can be determined in pyrite, chalcocite, and marcasite by a simple and rapid spectrochemical method that requires no complicated arrangement of spectrographic equipment or chemical pretreatment of samples. Advantage is taken of the new short wave length radiation plates (Eastman) and the addition of copper oxide to enhance the selenium lines 2039.85 and 2062.78 A. The possibility exists of determining many other elements on the same exposure of the sample. The method is applicable in the range of 0.0015 to 2% selenium. Tests indicate an average difference from the chemical results of 0.07% in the few per cent range, 0.03% in the 0.1 to 1.0% range, 0.005% in the 0.01 to 0.1% range, and 0.00075% in the 0.001 to 0.01% range. The relative accuracy over the entire range is to about 7% of the concentration.

  10. Synthesis of selenium particles with various morphologies.

    PubMed

    Kumar, Ajeet; Sevonkaev, Igor; Goia, Dan V

    2014-02-15

    Uniform selenium spherical particles were prepared by reducing selenous acid with hydroquinone in the presence of Daxad 11G. The red colored colloidal dispersions displayed a distinct plasmon band at ~612 nm and were stable for extended time due to the negative surface potential of the particles. Structural analyses indicated that the Se spheres were aggregates of nanosize subunits crystallized in the hexagonal system. Selenium wires and rods were obtained by changing the pH and the composition of the precipitated dispersions and incubating them for extended time at moderate temperatures. The addition of a co-solvent played a major role in the re-crystallization of selenium spheres into anisotropic structures. PMID:24370410

  11. Synthesis and stabilization of selenium nanoparticles on cellulose nanocrystal

    SciTech Connect

    Shin, Yongsoon; Blackwood, Jade M.; Bae, In-Tae; Arey, Bruce W.; Exarhos, Gregory J.

    2007-08-01

    Selenium nanoparticles of 10-20 nm in diameter have been prepared using cellulose nanocrystal (CNXL) as a reducing and structure-directing agent under hydrothermal conditions. Na2SeO3 was reduced to form elemental selenium nanoparticles under hydrothermal conditions. During the hydrothermal process (120-160 oC), CNXL rods were mainly maintained and selenium nanoparticles were interfacially bound to CNXL surface. The reaction temperature affects the sizes of interfacially bound selenium nanoparticles. X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and transmission electron microscope (TEM) were employed to characterize interfacially bound selenium nanoparticles on CNXL surface.

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

    NASA Technical Reports Server (NTRS)

    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.

  13. Selenium speciation in ground water. Quarterly report

    SciTech Connect

    Atalay, A.

    1990-07-10

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

  14. Sewage sludge as a source of environmental selenium.

    PubMed

    Cappon, C J

    1991-03-01

    Information is presented on the impact of land application of municipal sewage sludge on the selenium content and speciation in soil, groundwater and edible vegetation. Sources and typical concentrations of selenium in sludge are documented. A discussion of selenium uptake by agricultural crops from sludge-amended soil includes results from greenhouse and field studies. A comparison is made with crop selenium uptake from fly ash application. The effect of sludge treatment on animal and human dietary selenium intake is quantitatively evaluated and selenium guidelines for sludge application are summarized. The conclusion is made that future widespread use of sludge on agricultural land will result in increased selenium uptake by food crops and human dietary intake. While this may not present an increased human health risk, long-term risks are identified and recommendations are made to minimize them. PMID:2063182

  15. Influences of fiber, methionine and form of selenium on selenium hindgut targeting and tissue accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased selenium (Se) status has beneficial outcomes, including decreased colorectal cancer risk, yet obesity may interfere with Se metabolism. Commensal bacteria can influence colon carcinogenesis and Se influences the microbiome, including production of volatile fatty acids by these microbes. We...

  16. Selenium or no selenium--that is the question in tumor patients: a new controversy.

    PubMed

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

    2010-06-01

    The essential trace element selenium, which is a crucial cofactor in the most important endogenous antioxidative systems of the human body, is attracting more attention from both laypersons and expert groups. The interest of oncologists mainly focuses on the following clinical aspects: protection of normal tissues, sensitizing in malignant tumors, antiedematous effect, prognostic impact of selenium, and effects in primary and secondary cancer prevention. Selenium is a constituent of the small group of selenocysteine-containing selenoproteins and elicits important structural and enzymatic functions. Selenium deficiency has been linked to increased infection risk and adverse mood states. It has been shown to possess cancer-preventive and cytoprotective activities in both animal models and humans. It is well established that it has a key role in redox regulation and antioxidant function, and hence in membrane integrity, energy metabolism, and protection against DNA damage. Recent clinical trials have shown the importance of selenium in clinical oncology. In 2009, a significant benefit of sodium selenite supplementation-with no protection of tumor cells, which is often suspected by oncologists- was shown in a prospective randomized trial in gynecologic cancer patients undergoing radiation therapy. More recently, concerns arose from 2 large clinical prevention trials (NPC, SELECT) that selenium may increase the risk of developing type 2 diabetes. Despite obvious flaws in both studies and good counterarguments, controversy remains on the possible advantages and risks of selenium in cancer prevention. However, in the light of the recent clinical trials the potential benefits of selenium supplementation in tumor patients are becoming obvious, even though further research is needed. PMID:20462857

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

    SciTech Connect

    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.

    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.

  18. The effect of consumption of selenium enriched rye/wheat sourdough bread on the body's selenium status.

    PubMed

    Bryszewska, Malgorzata A; Ambroziak, Wojciech; Langford, Nicola J; Baxter, Malcolm J; Colyer, Alison; Lewis, D John

    2007-09-01

    The potential of selenium-enriched rye/wheat sourdough bread as a route for supplementing dietary selenium intakes is reported. In addition to their normal diets, 24 female volunteers (24 to 25 years old) were fed either selenium-enriched bread or non-enriched bread each day (68.02 and 0.84 microg selenium day(-1) respectively) for 4 weeks. The chemical form of the selenium in the bread had been characterised using HPLC-ICP-MS, which showed that 42% of the extractable selenium was present as selenomethionine. Plasma selenium levels and plasma platelet glutathione peroxidase (GPx1) activity were measured in the volunteers' blood over a 6-week period. A statistically significant difference (p = 0.001) was observed in the mean percentage change data, calculated from the plasma selenium level measurements for the enriched and control group, over the duration of the study. A comparable difference was not observed for the platelet GPx1 activity (p = 0.756), over the same period. Two weeks after cessation of the feeding stage, i.e., at t = 6 weeks, the mean percentage change value for the selenium plasma levels in the enriched group was still significantly elevated, suggesting that the absorbed selenium had been incorporated into the body's selenium reserves, and was then being slowly released back into the volunteers' blood. PMID:17721822

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

    PubMed Central

    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

  20. Selenium, glutathione peroxidase and other selenoproteins

    SciTech Connect

    Wilhelmsen, E.C.

    1983-01-01

    Selenium, as essential trace element, has long been associated with protein. The essentiality of selenium is partially understood as glutathione peroxidase contains an essential selenocysteine. Glutathione peroxidase has been purified from many tissues including rat liver. An estimated molecular weight of 105,000 was obtained for glutathione peroxidase by comparison to standards. A subunit size of 26,000 was obtained by SDS-gel electrophoresis. Glutathione peroxidase is not the only selenoprotein in the rat. In seven rat tissues examined, there were many different subunit sizes and change groups representing between 9 and 23 selenoproteins. Selenocysteine in glutathione peroxidase accounts for ca. 36% of the selenium in the rat. The mode of synthesis of glutathione peroxidase and the other selenoproteins is not understood. Glutathione peroxidase is strongly and reversibly inhibited by mercaptocarboxylic acids and other mercaptans, including some used as slow-acting drugs for the symtomatic treatment of rheumatoid arthritis. The mechanism and chemistry of this inhibition is discussed. This inhibition may provide a link between selenium and arthritis.

  1. Status of selenium in cancer prevention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Responses to Selenium Supplementation in Healthy Americans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To determine dose-response relationships of selenium (Se) intake and markers of Se status in healthy, non-deficient subjects, we conducted a 12 mo. intervention using Se supplements (0, 50, 100 or 200 ug Se [as L-selenomethionine]/d) in a group of 106 men and 155 women. At baseline, this cohort, non...

  3. Selenium as a cancer preventive agent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most epidemiological studies have shown inverse associations of selenium (Se) status and cancer risk. Almost all experimental animal studies have shown that supranutritional exposures of Se can reduce tumor yield. Each of the limited number of clinical intervention trials conducted to date has found...

  4. Genetic Determinants of Responses to Selenium Supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  5. Chapter 6: Selenium Toxicity to Aquatic Organisms

    EPA Science Inventory

    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...

  6. Mercury and selenium content of Taiwanese seafood.

    PubMed

    Fang, G C; Nam, D H; Basu, N

    2011-01-01

    Fish consumption is avid in Taiwan (and other Asian nations), but little is known about the mercury and selenium content in local seafood. This paper reports on total mercury, methylmercury and selenium levels from 14 commonly consumed seafood items obtained from Taichung, Taiwan. Mean total mercury concentrations varied nearly 100-fold across species. Fifty per cent of the marlins sampled and 35% of the sharks exceeded the 0.3 µg g(-1) US Environmental Protection Agency (USEPA) guideline. Methylmercury comprised a majority of the total mercury in all species. In all species studied there was a molar excess of selenium over mercury. The rank order of mean selenium-mercury molar ratios was red tilapia (166.8) > abura (87.9) > river prawn (82.4) > whiteleg shrimp (64.2) > butterfish (44.6) > milkfish (37.0) > tuna (15.6) > grouper (13.9) > ayu (13.4) > coral hind (13.0) > weever (11.8) > saury (9.0) > shark (7.8) > marlin (4.2). PMID:24786009

  7. Selenium in Oklahoma ground water and soil

    SciTech Connect

    Atalay, A.; Vir Maggon, D.

    1991-03-30

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

  8. Rapid determination of selenium in grain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of selenium (Se)-enriched foods to reduce cancer risk would require servings to provide amounts of Se that, when added to daily Se intakes from other foods, would raise consumers’ plasma Se levels to those associated with reduced cancer risk, e.g., >120 ng/ml (Duffield et al, JNCI 95...

  9. Application of Radial Basis Function Methods in the Development of a 95th Percentile Male Seated FEA Model.

    PubMed

    Vavalle, Nicholas A; Schoell, Samantha L; Weaver, Ashley A; Stitzel, Joel D; Gayzik, F Scott

    2014-11-01

    Human body finite element models (FEMs) are a valuable tool in the study of injury biomechanics. However, the traditional model development process can be time-consuming. Scaling and morphing an existing FEM is an attractive alternative for generating morphologically distinct models for further study. The objective of this work is to use a radial basis function to morph the Global Human Body Models Consortium (GHBMC) average male model (M50) to the body habitus of a 95th percentile male (M95) and to perform validation tests on the resulting model. The GHBMC M50 model (v. 4.3) was created using anthropometric and imaging data from a living subject representing a 50th percentile male. A similar dataset was collected from a 95th percentile male (22,067 total images) and was used in the morphing process. Homologous landmarks on the reference (M50) and target (M95) geometries, with the existing FE node locations (M50 model), were inputs to the morphing algorithm. The radial basis function was applied to morph the FE model. The model represented a mass of 103.3 kg and contained 2.2 million elements with 1.3 million nodes. Simulations of the M95 in seven loading scenarios were presented ranging from a chest pendulum impact to a lateral sled test. The morphed model matched anthropometric data to within a rootmean square difference of 4.4% while maintaining element quality commensurate to the M50 model and matching other anatomical ranges and targets. The simulation validation data matched experimental data well in most cases. PMID:26192960

  10. Seasonal to decadal forcing of high water level percentiles in the German Bight throughout the last century

    NASA Astrophysics Data System (ADS)

    Dangendorf, Sönke; Mudersbach, Christoph; Jensen, Jürgen; Anette, Ganske; Heinrich, Hartmut

    2013-05-01

    For the purpose of coastal planning and management, especially under changing climatic conditions, enhanced knowledge about the evolution of extreme sea levels in the past, present, and future is required. This paper presents statistical analyses of high seasonal water level percentiles of 13 tide gauges in the German Bight, spanning over a period of up to 109 years throughout the twentieth and twenty-first centuries. Seasonal and annual high percentile time series of water levels were investigated in comparison to the mean sea level (MSL) for changes on seasonal, inter-annual, and decadal timescales. While throughout the first half of the twentieth century extreme water levels generally followed changes in MSL, during the second half of the century, linear extreme sea level trends exceeded those in MSL in the order of 9-64 cm per century. The largest, although insignificant, contribution to the magnitude of these trends occurs in the winter season (January to March), while smaller but, due to the generally lower atmospheric variability, significant changes are observed during spring (April to June). The observed multi-decadal trends are generally in good agreement with multi-decadal trends in the corresponding percentiles of local zonal surface winds. Only small parts of the trends remain unexplained. It is suggested that these remaining trends result from modifications in the local tidal regime. For the aspects of coastal planning, the findings clarify that in the German Bight, in addition to changes in MSL, potential changes in storminess and in the tidal regime significantly contribute to the development of extreme water levels. Since these factors have influenced the characteristic of extremes throughout the recent past, they also have to be taken into account when estimating design water levels for, e.g., dikes (in a warming climate) under changing greenhouse gas emissions.

  11. Skeletal muscle disorders associated with selenium deficiency in humans.

    PubMed

    Chariot, Patrick; Bignani, Olivier

    2003-06-01

    Skeletal muscle disorders manifested by muscle pain, fatigue, proximal weakness, and serum creatine kinase (CK) elevation have been reported in patients with selenium deficiency. The object of this report was to review the conditions in which selenium deficiency is associated with human skeletal muscle disorders and to evaluate the importance of mitochondrial alterations in these disorders. A systematic literature review using the Medline database and Cochrane Library provided 38 relevant articles. The main conditions associated with selenium deficiency fell into three categories: (1) insufficient selenium intake in low soil-selenium areas; (2) parenteral or enteral nutrition, or malabsorption; and (3) chronic conditions associated with oxidative stress, such as chronic alcohol abuse and human immunodeficiency virus (HIV) infection. In low soil-selenium areas, reversibility of muscle symptoms was similar after selenium supplementation and placebo administration, suggesting a role for other factors in the development of disease. In parenteral or enteral nutrition, or malabsorption, muscle symptoms improved after selenium supplementation in 18 of 19 patients (median delay: 4 weeks). The reason that only a minority of selenium-deficient patients present with skeletal muscle disorders is unclear and is possibly related to cofactors, such as viral infections and drugs. Prospective studies of selenium-deficient myopathies would be useful in critically ill patients, alcohol abusers, and HIV-infected patients. PMID:12766976

  12. Recovery of stream communities from experimental selenium exposure

    SciTech Connect

    Swift, M.C.; Kuklinskal, B.; Ferkull, K.; Allen, K.N.; Hermanutz, R.O.; Roush, T.H.; Hedtke, S.F.

    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.

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

    PubMed Central

    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 <0.001) but not for the malnourished (OR = 1.03; 95% CI 0.99 to 1.08, P = 0.16). Conclusions There is a significant interaction between the magnitude of the inflammatory

  14. Enrichment of selenium in allium vegetables for cancer prevention.

    PubMed

    Ip, C; Lisk, D J

    1994-09-01

    We previously reported that garlic cultivated with selenium fertilization is superior to regular garlic in mammary cancer prevention in the rat 7,12-dimethylbenz[a]anthracene (DMBA) model (Nutr. Cancer, 17, 279-286, 1992). A new crop of high-selenium garlic was harvested in 1992 and was used in a dose-response study to confirm the reproducibility of the product and the bioassay. Supplementation of 1 or 2 p.p.m. Se in the diet from the high-selenium garlic produced a 56% or 75% reduction respectively in the total tumor yield. Since both garlic and onion belong to the same allium family of vegetables, we were also interested in finding out whether our experience with garlic could be similarly applied to onion. A high-selenium onion crop was grown in the same season and location and with the same schedule of selenium fertilization. Two distinct differences were noted with the high-selenium onion regarding its capacity to accumulate selenium and its efficacy in cancer prevention. First, the selenium concentration in onion was considerably lower (28 p.p.m. Se dry wt) as compared to that found in garlic (110-150 p.p.m. Se). Second, given the same levels of selenium supplementation, the high-selenium onion was apparently not as powerful as the high-selenium garlic in mammary cancer inhibition. Thus different plants, even those of the same genus, may respond in their unique way to selenium fertilization and the biological benefits of selenium enrichment may vary depending on the species. Additional information from our study indicated that the high-selenium garlic/onion might provide an ideal system for delivering selenium-substituted analogs in a food form for cancer prevention: (i) they expressed a good range of anticancer activity and could be easily adapted for human consumption on a regular basis; (ii) their ingestion did not result in an excessive accumulation of tissue selenium, a concern that is associated with the standard selenium compounds such as selenite and

  15. Ecology and Biotechnology of Selenium-Respiring Bacteria

    PubMed Central

    2015-01-01

    SUMMARY In nature, selenium is actively cycled between oxic and anoxic habitats, and this cycle plays an important role in carbon and nitrogen mineralization through bacterial anaerobic respiration. Selenium-respiring bacteria (SeRB) are found in geographically diverse, pristine or contaminated environments and play a pivotal role in the selenium cycle. Unlike its structural analogues oxygen and sulfur, the chalcogen selenium and its microbial cycling have received much less attention by the scientific community. This review focuses on microorganisms that use selenate and selenite as terminal electron acceptors, in parallel to the well-studied sulfate-reducing bacteria. It overviews the significant advancements made in recent years on the role of SeRB in the biological selenium cycle and their ecological role, phylogenetic characterization, and metabolism, as well as selenium biomineralization mechanisms and environmental biotechnological applications. PMID:25631289

  16. Ecology and biotechnology of selenium-respiring bacteria.

    PubMed

    Nancharaiah, Y V; Lens, P N L

    2015-03-01

    In nature, selenium is actively cycled between oxic and anoxic habitats, and this cycle plays an important role in carbon and nitrogen mineralization through bacterial anaerobic respiration. Selenium-respiring bacteria (SeRB) are found in geographically diverse, pristine or contaminated environments and play a pivotal role in the selenium cycle. Unlike its structural analogues oxygen and sulfur, the chalcogen selenium and its microbial cycling have received much less attention by the scientific community. This review focuses on microorganisms that use selenate and selenite as terminal electron acceptors, in parallel to the well-studied sulfate-reducing bacteria. It overviews the significant advancements made in recent years on the role of SeRB in the biological selenium cycle and their ecological role, phylogenetic characterization, and metabolism, as well as selenium biomineralization mechanisms and environmental biotechnological applications. PMID:25631289

  17. Selenium Recycling in the United States in 2004

    USGS Publications Warehouse

    George, Micheal W.; Wagner, Lorie A.

    2009-01-01

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

  18. Selenium accumulation and selenium-salt co-tolerance in five grass species. [Festuca arundinaceae; Agropyron deserorum; Buchloe dactyloides; Agrostis stolonifera; Cynodon dactylon

    SciTech Connect

    Wu, L.; Huang, Z.; Burau, R.G.

    1987-04-01

    Five grass species including Tall fescue (Festuca arundinaceae Schred), Crested wheatgrass (Agropyron deserorum Fisch), Buffalo grass (Buchlor dactyloides (Nutt.) Engelm.), Seaside bentgrass (Agrostis stolonifera L.) and Bermuda grass (Cynodon dactylon (L.) Pers., Syn.) were examined for selenium and salt tolerance and selenium accumulation under solution culture conditions. Distinct differences in both selenium and salt tolerance were detected among the five species, but no direct association between selenium and salt resistance was found. Tall fescue displayed considerable tolerance under 1 ppm selenium and 100 mM salt treatment. Combined selenium and salt treatment revealed that selenium uptake was increased by the incorporation of salt in the culture solution. However, salt uptake was not significantly affected by the presence of selenium in the culture solution. At moderate toxic levels of selenium, the species with greater tolerance accumulated less selenium than did the less tolerant species.

  19. Synthesis and characterization of single crystalline selenium nanowire arrays

    SciTech Connect

    Zhang, X.Y. . E-mail: apzhxy@polyu.edu.hk; Xu, L.H.; Dai, J.Y.; Cai, Y.; Wang, N.

    2006-09-14

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

  20. 21 CFR 522.2100 - Selenium and vitamin E.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Selenium and vitamin E. 522.2100 Section 522.2100... Selenium and vitamin E. (a)(1) Specifications. Each milliliter of emulsion contains 5.48 milligrams (mg) sodium selenite (equivalent to 2.5 mg selenium) and 50 mg of vitamin E (68 I.U.) (as d-alpha...

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

    SciTech Connect

    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.

  2. Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium.

    PubMed

    Contempre, B; Dumont, J E; Ngo, B; Thilly, C H; Diplock, A T; Vanderpas, J

    1991-07-01

    Selenium and seleno dependent glutathione peroxidase (GPX) deficiency has been described in endemias of myxedematous cretinism. In northern Zaire, a selenium supplementation trial has been conducted. Beside correcting the GPX activity, two months of selenium supplementation was shown to modify the serum thyroid hormones parameters in clinically euthyroid subjects and to induce a dramatic fall of the already impaired thyroid function in clinically hypothyroid subjects. These results further support a role of selenium in thyroid hormone metabolism. In an iodine deficient area, this selenium deficiency could lead to opposite clinical consequences: protect the general population and the fetus against iodine deficiency and brain damage; and in turn, favour the degenerative process of the thyroid gland leading to myxoedematous cretinism. PMID:2045471

  3. Immunomodulatory effect of selenosemicarbazides and selenium inorganic compounds, distribution in organs after selenium supplementation.

    PubMed

    Musik, I; Koziol-Montewka, M; Toś-Luty, S; Pasternak, K; Latuszyńska, J; Tokarska, M; Kielczykowska, M

    1999-12-01

    Antioxidant properties of selenium producing a protective barrier against free radicals play an important role in numerous metabolic and immunologic processes associated with oxidation-reduction reactions which take place during intracellular digestion of phagocyted bacteria. The aim of our study was to examine the properties of an organic compound of selenium, 4-(o-tolilo)-selenosemicarbazide of p-chlorobenzoic acid in terms of its retention in organs, effect on erythropoesis and phagocytic abilities of neutrophiles as well as antioxidant properties in neutrophiles tested with NBT test. This compound as well as inorganic sodium selenate was given to Swiss mice at the dose of 10(-3) g Se/kg for the period of 10 days. The concentrations of selenium in livers of mice treated with sodium selenate and selenosemicarbazide were found to be higher than in controls (18.7 micrograms lg-1 and 23.2 micrograms lg-1 vs. 12 micrograms lg-1, respectively). Analysis of blood cells count has shown a significant decrease in neutrophile levels in both groups treated with selenium. The influence of selenium compounds on phagocytosis and especially NBT test has been determined (3.8% of positive cells in the controls vs. 2.2% and 0.9% in the groups treated with sodium selenate and selenosemicarbazide, respectively). Our preliminary investigations suggest that selenosemicarbazides are biologically active compounds and can modify neutrophile functions. PMID:10816738

  4. Assessment of selenium bioavailability from naturally produced high-selenium soy foods in selenium-deficient rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We assessed the bioavailability of selenium (Se) from protein isolate and tofu (bean curd) prepared from naturally produced high-Se soybeans in a Se-deficient rat model. The Se content of soybean seeds, protein isolate and tofu was 5.17 ± 0.22, 11.44 ± 0.09 and 7.37 ± 0.12 mg/kg, respectively. Male ...

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

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

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

  6. Selenium status in food grains of northern districts of India.

    PubMed

    Yadav, Sanjiv K; Singh, Ishwar; Sharma, Anita; Singh, Devender

    2008-09-01

    The selenium status in the food grains of the agricultural lands of northern parts of India was estimated by using the HG-AAS technique. The areas where lesser rains were received or less irrigation water was available in northern Indian states viz. Rajasthan and southern parts of the Haryana had higher selenium levels in food grains. Punjab, Himachal Pradesh and northern parts of the Haryana states had normal levels of selenium in their food grains, except for slightly lower selenium levels in a few areas that were affected by floods along the river Yamuna. PMID:17574725

  7. Selenium status in soils of northern districts of India.

    PubMed

    Yadav, Sanjiv K; Singh, Ishwar; Singh, Devender; Han, Sang-Do

    2005-04-01

    The HG-AAS technique was used to estimate the soil selenium status of the agricultural lands of northern parts of India. The drier lands where lesser rains were received or where less irrigation water was available in Rajasthan and southern parts of the Haryana states had above normal soil selenium levels. These soils were also found to be alkaline. Punjab, Himachal Pradesh and northern parts of the Haryana states had normal levels of selenium in their soils, except with slightly lower selenium levels in a few areas that were affected by floods along the river Yamuna. The results were also confirmed using the ICP-OES technique. PMID:15763155

  8. Accumulation and metabolism of selenium by yeast cells.

    PubMed

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

    2015-07-01

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

  9. Effects of selenium on mallard duck reproduction and immune function

    SciTech Connect

    Whiteley, P.L.; Yuill, T.M.; Fairbrother, A.

    1989-11-01

    Selenium from irrigation drain water and coal-fired power stations is a significant environmental contaminant in some regions of the USA. The objectives were to examine whether selenium-exposed waterfowl had altered immune function, disease resistance, or reproduction. Pairs of adult mallards were exposed for 95-99 days on streams with sodium selenite-treated water at 10 and 30 ppb, or on untreated streams. Selenium biomagnified through the food chain to the ducks. Disease resistance was decreased in ducklings hatched on the streams and challenged with duck hepatitis virus 1 (DHV1) when 15-days old. Liver selenium concentrations for these ducklings on the 10 and 30 ppb streams was 3.6 and 7.6 ppm dry weight, respectively. Mortality of ducklings purchased when 7-days old, exposed to selenium for 14 days, and challenged when 22-days old was not affected. However, their selenium exposure was lower (liver selenium 4.1 ppm dry weight for the 30 ppb stream). Five parameters of immune function were measured in adult ducks. Phagocytosis of killed Pasteurella multocida by blood heterophils and monocytes, and blood monocyte concentrations were higher in adult males following 84 days exposure to 30 ppb selenium. Their liver selenium concentrations were 11.1 ppm dry weight after 95-99 days exposure.

  10. Plasma selenium levels and the risk of colorectal adenomas.

    PubMed

    Russo, M W; Murray, S C; Wurzelmann, J I; Woosley, J T; Sandler, R S

    1997-01-01

    Previous research has suggested that selenium may protect against the development of colorectal neoplasia. We examined the potential chemopreventive properties of selenium against colorectal adenomas while controlling for a number of dietary and life-style factors. We conducted a cross-sectional study among patients referred for colonoscopy to University of North Carolina Hospitals. Cases had one or more pathologically confirmed adenomas, and noncases had none. Plasma selenium levels were determined using graphite furnace atomic absorption spectrometry with Zeeman background correction and platform technique. Odds ratios were calculated using logistic regression analysis adjusting for potential confounders. The mean plasma selenium concentrations for cases (n = 37) and noncases (n = 36) were 107 and 120 micrograms/l, respectively (p = 0.06). Those in the fourth quartile of plasma selenium level had 0.24 times the risk (95% confidence interval = 0.06-1.04) for colorectal adenomas of those in the first quartile. The adjusted odds ratio for colorectal adenomas was 0.58 (95% confidence interval = 0.31-1.08) for a 30 microgram/l increase in plasma selenium level. Lower plasma selenium levels were associated with multiple adenomas but not with adenoma size or location. These data support a protective effect of selenium against colorectal adenomas after adjustment for possible confounders. Selenium might be a potentially useful chemopreventive agent for colorectal neoplasia. PMID:9290116

  11. Hazard assessment of selenium to endangered razorback suckers (Xyrauchen texanus)

    USGS Publications Warehouse

    Hamilton, S.J.; Holley, K.M.; Buhl, K.J.

    2002-01-01

    A hazard assessment was conducted based on information derived from two reproduction studies conducted with endangered razorback suckers (Xyrauchen texanus) at three sites near Grand Junction, CO, USA. Selenium contamination of the upper and lower Colorado River basin has been documented in water, sediment, and biota in studies by US Department of the Interior agencies and academia. Concern has been raised that this selenium contamination may be adversely affecting endangered fish in the upper Colorado River basin. The reproduction studies with razorback suckers revealed that adults readily accumulated selenium in various tissues including eggs, and that 4.6 ??g/g of selenium in food organisms caused increased mortality of larvae. The selenium hazard assessment protocol resulted in a moderate hazard at the Horsethief site and high hazards at the Adobe Creek and North Pond sites. The selenium hazard assessment was considered conservative because an on-site toxicity test with razorback sucker larvae using 4.6 ??g/g selenium in zooplankton caused nearly complete mortality, in spite of the moderate hazard at Horsethief. Using the margin of uncertainty ratio also suggested a high hazard for effects on razorback suckers from selenium exposure. Both assessment approaches suggested that selenium in the upper Colorado River basin adversely affects the reproductive success of razorback suckers. ?? 2002 Elsevier Science B.V. All rights reserved.

  12. Hazard assessment of selenium to endangered razorback suckers (Xyrauchen texanus).

    PubMed

    Hamilton, Steven J; Holley, Kathleen M; Buhl, Kevin J

    2002-05-27

    A hazard assessment was conducted based on information derived from two reproduction studies conducted with endangered razorback suckers (Xyrauchen texanus) at three sites near Grand Junction, CO, USA. Selenium contamination of the upper and lower Colorado River basin has been documented in water, sediment, and biota in studies by US Department of the Interior agencies and academia. Concern has been raised that this selenium contamination may be adversely affecting endangered fish in the upper Colorado River basin. The reproduction studies with razorback suckers revealed that adults readily accumulated selenium in various tissues including eggs, and that 4.6 microg/g of selenium in food organisms caused increased mortality of larvae. The selenium hazard assessment protocol resulted in a moderate hazard at the Horsethief site and high hazards at the Adobe Creek and North Pond sites. The selenium hazard assessment was considered conservative because an on-site toxicity test with razorback sucker larvae using 4.6 microg/g selenium in zooplankton caused nearly complete mortality, in spite of the moderate hazard at Horsethief. Using the margin of uncertainty ratio also suggested a high hazard for effects on razorback suckers from selenium exposure. Both assessment approaches suggested that selenium in the upper Colorado River basin adversely affects the reproductive success of razorback suckers. PMID:12150431

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

    PubMed

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

    2015-01-01

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

  14. Volatile Selenium Flux in the Great Salt Lake

    NASA Astrophysics Data System (ADS)

    Diaz, X.; Johnson, W. P.

    2006-12-01

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

  15. [Retention of selenium volatility using lime in coal combustion].

    PubMed

    Zhang, J; Ren, D; Zhong, Q; Xu, F; Zhang, Y; Yin, J

    2001-05-01

    For understanding the volatility of selenium, the effect of the contents of exchangeable cations of coal on it, and the retention of selenium using CaO in coal combustion, the sequential chemistry extraction, the fixed bed and circulating fluidized bed (CFB) combustion, X-ray diffraction (XRD) and atomic fluorescence spectrometry (AFS) were undertaken. The results showed that the volatility of selenium was more than 97% in coal combustion at 815 degrees C, and the volatility of selenium was affected by the content of exchangeable cations of coal in low-middle temperature. It was identified that lime can restrain the volatility of selenium. In fixed bed combustion of coal, the retention rates of selenium volatility were between 11.6% and 50.7% using lime. In circulating fluidized bed combustion of coal, partitioning of selenium changed very much in ash of different size fraction between without lime and with lime. Comparing with combustion without lime, the content of selenium in ash from chimney was less than fourth times and that in leaching water from chimney decreased by two orders of magnitude using lime. Retention of selenium volatility using lime is so effective in coal combustion, especially in CFB combustion of coal. PMID:11507891

  16. The leaching characteristics of selenium from coal fly ashes

    SciTech Connect

    Wang, T.; Wang, J.; Burken, J.G.; Ban, H.; Ladwig, K.

    2007-11-15

    The leaching characteristics of selenium from several bituminous and subbituminous coal fly ashes under different pH conditions were investigated using batch methods. Results indicated that pH had a significant effect on selenium leaching from bituminous coal ash. The minimum selenium leaching occurred in the pH range between 3 and 4, while the maximum selenium leaching occurred at pH 12. The release of selenium from subbituminous coal ashes was very low for the entire experimental pH range, possibly due to the high content of calcium which can form hydration or precipitation products as a sink for selenium. The adsorption results for different selenium species indicated that Se(VI) was hardly adsorbable on either bituminous coal ashes or subbitumminous coal ashes at any pH. However, Se(I) was highly adsorbed by bituminous coal ashes under acidic pH conditions and was mostly removed by subbitumminous coal ashes across the entire pH range. This result suggests that the majority of selenium released from the tested fly ashes was Se(IV). A speciation-based model was developed to simulate the adsorption of Se(IV) on bituminous coal fly ash, and the pH-independent adsorption constants of HSeO{sup 3-} and SeO{sub 3}{sup 2-} were determined. The modeling approach is useful for understanding and predicting the release process of selenium from fly ash.

  17. Microbially induced synthesis of cubic and hexagonal selenium nanoparticles.

    PubMed

    Park, Bitna; Kang, Serku; Moon, Wonjin; Roh, Yul

    2013-03-01

    Nanobiotechnology represents an economic alternative for chemical and physical methods of nanoparticles formation. The objectives of this study were to synthesize selenium nanoparticles by microbial processes using anaerobic metal-reducing bacteria as well as to characterize mineralogical properties of the nanoparticles. The selenium nanoparticles were about 200 nm in size and ball shaped. Microbial processes for elemental selenium synthesis may be useful for recovery of natural selenate in the natural environments and immobilization of selenium isotope in the high level nuclear waste disposal sites. PMID:23755605

  18. Selenium nanomaterials: applications in electronics, catalysis and sensors.

    PubMed

    Chaudhary, Savita; Mehta, S K

    2014-02-01

    This review provides insights into the synthesis, functionalization, and applications of selenium nanoparticles in electronics, optics, catalysis and sensors. The variation of physicochemical properties such as particle size, surface area, and shape of the selenium nanoparticles and the effect of experimental conditions has also been discussed. An overview has also been provided on the fundamental electrical and optical properties of selenium nanomaterials as well as their utilization in different research fields. The work presents an insight on selenium nanoparticles with interesting properties and their future applications. PMID:24749448

  19. Preparation of selenium coatings onto beryllium foils

    SciTech Connect

    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.

  20. Biofortification and phytoremediation of selenium in China.

    PubMed

    Wu, Zhilin; Bañuelos, Gary S; Lin, Zhi-Qing; Liu, Ying; Yuan, Linxi; Yin, Xuebin; Li, Miao

    2015-01-01

    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. Selenium 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. PMID:25852703

  1. Biofortification and phytoremediation of selenium in China

    PubMed Central

    Wu, Zhilin; Bañuelos, Gary S.; Lin, Zhi-Qing; Liu, Ying; Yuan, Linxi; Yin, Xuebin; Li, Miao

    2015-01-01

    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. Selenium 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. PMID:25852703

  2. Selenium Derivatization of Nucleic Acids for Crystallography

    SciTech Connect

    Jiang,J.; Sheng, J.; Carrasco, N.; Huang, Z.

    2007-01-01

    The high-resolution structure of the DNA (5'-GTGTACA-C-3') with the selenium derivatization at the 2'-position of T2 was determined via MAD and SAD phasing. The selenium-derivatized structure (1.28 {angstrom} resolution) with the 2'-Se modification in the minor groove is isomorphorous to the native structure (2.0 {angstrom}). To directly compare with the conventional bromine derivatization, we incorporated bromine into the 5-postion of T4, determined the bromine-derivatized DNA structure at 1.5 {angstrom} resolution, and found that the local backbone torsion angles and solvent hydration patterns were altered in the structure with the Br incorporation in the major groove. Furthermore, while the native and Br-derivatized DNAs needed over a week to form reasonable-size crystals, we observed that the Se-derivatized DNAs grew crystals overnight with high-diffraction quality, suggesting that the Se derivatization facilitated the crystal formation. In addition, the Se-derivatized DNA sequences crystallized under a broader range of buffer conditions, and generally had a faster crystal growth rate. Our experimental results indicate that the selenium derivatization of DNAs may facilitate the determination of nucleic acid X-ray crystal structures in phasing and high-quality crystal growth. In addition, our results suggest that the Se derivatization can be an alternative to the conventional Br derivatization.

  3. Selenium in biology: facts and medical perspectives.

    PubMed

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

    2000-01-01

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

  4. Zinc and selenium nutritional status in vegetarians.

    PubMed

    de Bortoli, Maritsa Carla; Cozzolino, Silvia Maria Franciscato

    2009-03-01

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

  5. Birth Weight Ratio as an Alternative to Birth Weight Percentile to Express Infant Weight in Research and Clinical Practice: A Nationwide Cohort Study

    PubMed Central

    Kazemier, Brenda M.; Schuit, Ewoud; Mol, Ben Willem J.; Pajkrt, Eva; Ganzevoort, Wessel

    2014-01-01

    Objective. To compare birth weight ratio and birth weight percentile to express infant weight when assessing pregnancy outcome. Study Design. We performed a national cohort study. Birth weight ratio was calculated as the observed birth weight divided by the median birth weight for gestational age. The discriminative ability of birth weight ratio and birth weight percentile to identify infants at risk of perinatal death (fetal death and neonatal death) or adverse pregnancy outcome (perinatal death + severe neonatal morbidity) was compared using the area under the curve. Outcomes were expressed stratified by gestational age at delivery separate for birth weight ratio and birth weight percentile. Results. We studied 1,299,244 pregnant women, with an overall perinatal death rate of 0.62%. Birth weight ratio and birth weight percentile have equivalent overall discriminative performance for perinatal death and adverse perinatal outcome. In late preterm infants (33+0–36+6 weeks), birth weight ratio has better discriminative ability than birth weight percentile for perinatal death (0.68 versus 0.63, P  0.01) or adverse pregnancy outcome (0.67 versus 0.60, P < 0.001). Conclusion. Birth weight ratio is a potentially valuable instrument to identify infants at risk of perinatal death and adverse pregnancy outcome and provides several advantages for use in research and clinical practice. Moreover, it allows comparison of groups with different average birth weights. PMID:25197283

  6. Selenium bioavailability: current knowledge and future research requirements.

    PubMed

    Fairweather-Tait, Susan J; Collings, Rachel; Hurst, Rachel

    2010-05-01

    Information on selenium bioavailability is required to derive dietary recommendations and to evaluate and improve the quality of food products. The need for robust data is particularly important in light of recent suggestions of potential health benefits associated with different intakes of selenium. The issue is not straightforward, however, because of large variations in the selenium content of foods (determined by a combination of geologic/environmental factors and selenium supplementation of fertilizers and animal feedstuffs) and the chemical forms of the element, which are absorbed and metabolized differently. Although most dietary selenium is absorbed efficiently, the retention of organic forms is higher than that of inorganic forms. There are also complications in the assessment and quantification of selenium species within foodstuffs. Often, extraction is only partial, and the process can alter the form or forms present in the food. Efforts to improve, standardize, and make more widely available techniques for species quantification are required. Similarly, reliable and sensitive functional biomarkers of selenium status are required, together with improvements in current biomarker methods. This requirement is particularly important for the assessment of bioavailability, because some functional biomarkers respond differently to the various selenium species. The effect of genotype adds a potential further dimension to the process of deriving bioavailability estimates and underlines the need for further research to facilitate the process of deriving dietary recommendations in the future. PMID:20200264

  7. Microbial Transformations of Selenium Species of Relevance to Bioremediation.

    PubMed

    Eswayah, Abdurrahman S; Smith, Thomas J; Gardiner, Philip H E

    2016-08-15

    Selenium species, particularly the oxyanions selenite (SeO3 (2-)) and selenate (SeO4 (2-)), are significant pollutants in the environment that leach from rocks and are released by anthropogenic activities. Selenium is also an essential micronutrient for organisms across the tree of life, including microorganisms and human beings, particularly because of its presence in the 21st genetically encoded amino acid, selenocysteine. Environmental microorganisms are known to be capable of a range of transformations of selenium species, including reduction, methylation, oxidation, and demethylation. Assimilatory reduction of selenium species is necessary for the synthesis of selenoproteins. Dissimilatory reduction of selenate is known to support the anaerobic respiration of a number of microorganisms, and the dissimilatory reduction of soluble selenate and selenite to nanoparticulate elemental selenium greatly reduces the toxicity and bioavailability of selenium and has a major role in bioremediation and potentially in the production of selenium nanospheres for technological applications. Also, microbial methylation after reduction of Se oxyanions is another potentially effective detoxification process if limitations with low reaction rates and capture of the volatile methylated selenium species can be overcome. This review discusses microbial transformations of different forms of Se in an environmental context, with special emphasis on bioremediation of Se pollution. PMID:27260359

  8. Selenium impacts on razorback sucker, Colorado: Colorado River: III. Larvae

    USGS Publications Warehouse

    Hamilton, S.J.; Holley, K.M.; Buhl, K.J.; Bullard, F.A.

    2005-01-01

    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 ??g/L from 24-Road, 0.9 ??g/L from Horsethief, 5.5 ??g/L from Adobe Creek, and 10.7 ??g/L from the North Pond. Selenium in dietary items averaged 2.7 ??g/g in brine shrimp, 5.6 ??g/g in zooplankton from Horsethief east wetland, 20 ??g/g in zooplankton from Adobe Creek, and 39 ??g/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of ???4.6 ??g/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  10. Selenium impacts on razorback sucker, Colorado: Colorado River III. Larvae.

    PubMed

    Hamilton, Steven J; Holley, Kathy M; Buhl, Kevin J; Bullard, Fern A

    2005-06-01

    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 microg/L from 24-Road, 0.9 microg/L from Horsethief, 5.5 microg/L from Adobe Creek, and 10.7 microg/L from the North Pond. Selenium in dietary items averaged 2.7 microg/g in brine shrimp, 5.6 microg/g in zooplankton from Horsethief east wetland, 20 microg/g in zooplankton from Adobe Creek, and 39 microg/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of 4.6 microg/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish. PMID:15883090

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  12. EFFECTS OF SELENIUM ON MALLARD DUCK REPRODUCTION AND IMMUNE FUNCTION

    EPA Science Inventory

    Selenium from irrigation drain water and coal-fired power stations is a significant environmental contaminant in some regions of the USA. Our objectives were to examine whether selenium-exposed waterfowl had altered immune function, disease resistance, or reproduction. Pairs of a...

  13. Iodine and selenium deficiency associated with cretinism in northern Zaire.

    PubMed

    Vanderpas, J B; Contempré, B; Duale, N L; Goossens, W; Bebe, N; Thorpe, R; Ntambue, K; Dumont, J; Thilly, C H; Diplock, A T

    1990-12-01

    Selenium status was determined in an endemic-goiter area and in a control area of Zaire. Compared with the reference values of a noniodine-deficient area, serum selenium in subjects living in the core of the northern Zaire endemic-goiter belt (Karawa villages) was seven times lower in 52 school-children and similarly low in 23 cretins; erythrocyte glutathione peroxidase (RBC-GPX) was five times lower in schoolchildren and still two times lower in cretins (P = 0.004). In a less severely iodine-deficient city of the same endemia (Businga), selenium status was moderately altered. RBC-GPX activity was linearly associated with serum selenium concentration up to a value of 1140 nmol/L and leveled off at approximately 15 U/g Hb at greater selenium concentration. At Karawa villages, selenium supplementation normalized both the serum selenium and the RBC-GPX. This combined iodine and selenium deficiency could be associated with the elevated frequency of endemic myxedematous cretinism in Central Africa. PMID:2239787

  14. A global perspective of selenium deficiency and toxicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium is an essential nutrient that has a relatively narrow margin between ingested amounts that cause deficiency and toxicosis. Both selenium deficiency and toxicosis occur in several regions in many countries throughout the world and result in substantial losses to the livestock industry. Sel...

  15. Algal-bacterial treatment facility removes selenium from drainage water

    SciTech Connect

    Quinn, Nigel W.T.; Lundquist, Tryg J.; Green, F. Bailey; Zarate, Max A.; Oswald, William J.; Leighton, Terrance

    2000-01-25

    A demonstration algal-bacterial selenium removal (ABSR) facility has been treating agricultural drainage water in the Panoche Drainage District on the west side of the San Joaquin Valley since 1997. The project goals are to demonstrate the effectiveness of the ABSR technology for selenium removal, to investigate potential wildlife exposure to selenium at full-scale facilities, and to develop an operational plant configuration that will minimize the life-cycle cost for each pound of selenium removed. The facility consists of a series of ponds designed to promote native microorganisms that remove nitrate and selenium. Previous treatment research efforts sought to reduce selenium concentrations to less than 5 mu g/L, but the ABSR Facility demonstration focuses on providing affordable reduction of the selenium load that is discharged to the San Joaquin River. During 1997 and 1998, the best-performing ABSR plant configuration reduced nitrate by more than 95 percent and reduced total soluble selenium mass by 80 percent. Ongoing investigations focus on optimizing operational parameters and determining operational costs and scale-up engineering requirements. The preliminary total cost estimate for a 10-acre-foot per day ABSR facility is less than $200 per acre-foot of treated drainage water.

  16. Higher selenium status is associated with adverse blood lipid profile in British adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent findings have raised concern about possible associations of high selenium exposure with diabetes and hyperlipidemia in the US, a population with high selenium status. In the UK, a population with lower selenium status, there is little data on the association of selenium status with cardio-met...

  17. A broccoli COQ5 methyltransferase involved in ubiquinone biosynthesis mediates selenium volatilization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological selenium volatilization, which converts selenium into volatile compounds, provides an important means for the cleanup of selenium polluted environments. To identify novel genes whose products are involved in plant selenium volatilization, a broccoli cDNA encoding COQ5 methyltransferase (B...

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

    PubMed

    Logemann, E; Krützfeldt, B; Rokitzki, L

    1989-01-01

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

  19. Ionic liquid-induced synthesis of selenium nanoparticles

    SciTech Connect

    Langi, Bhushan; Shah, Chetan; Singh, Krishankant; Chaskar, Atul; Kumar, Manmohan; Bajaj, Parma N.

    2010-06-15

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

  20. SELENIUM CONCENTRATIONS AND GLULATHIONE PEROXIDASE ACTIVITIES IN A POPULATION EXPOSED TO SELENIUM VIA DRINKING WATER

    EPA Science Inventory

    Selenium concentrations in blood, urine, hair, and tap water were determined in samples obtained from individuals exposed to varying amounts of the element via water from home wells. Glutathione peroxidase activities were also determined on the blood samples. Correlations of bloo...

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

    PubMed

    Pedrero, Zoyne; Madrid, Yolanda; Cámara, Carmen

    2006-03-22

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. Selenium Supplementation Does Not Affect Testicular Selenium Status or Semen Quality in North American Men

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although selenium (Se) is essential for sperm function experimental animals, high Se intake in humans has been associated with both improvements and impairments in semen quality. We previously reported a decrease in sperm motility in five men fed high-Se foods in a metabolic research unit, but could...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Nanoporous selenium as a cathode material for rechargeable lithium-selenium batteries.

    PubMed

    Liu, Lili; Hou, Yuyang; Wu, Xiongwei; Xiao, Shiying; Chang, Zheng; Yang, Yaqiong; Wu, Yuping

    2013-12-21

    Nanoporous selenium was prepared by a simple mechanical method adopting nano-CaCO3 as a template. When used as a cathode, it can exhibit relatively high capacity and good cycling behaviour. These results present great promise for this new cathode material for rechargeable lithium batteries of high energy density. PMID:24175320

  6. Biological production of selenium-biofortified products from natural-occurring sources of selenium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Health problems associated with soil selenium (Se) deficiency and its subsequent low accumulation by plants have become major nutritional issues in many countries. Of the many strategies employed to increase animal and human absorption of Se, biofortification is a recent technique that utilizes a pl...

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

    PubMed

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

    2016-06-01

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

  8. Protective effect of selenium on lung cancer in smelter workers.

    PubMed Central

    Gerhardsson, L; Brune, D; Nordberg, I G; Wester, P O

    1985-01-01

    A possible protective effect of selenium against lung cancer has been indicated in recent studies. Workers in copper smelters are exposed to a combination of airborne selenium and carcinogens. In this study lung tissue concentrations of selenium, antimony, arsenic, cadmium, chromium, cobalt, lanthanum, and lead from 76 dead copper smelter workers were compared with those of 15 controls from a rural area and 10 controls from an urban area. The mean exposure time for the dead workers was 31.2 years, and the mean retirement time after the end of exposure 7.2 years. Lung cancer appeared in the workers with the lowest selenium lung tissue levels (selenium median value 71 micrograms/kg wet weight), as compared with both the controls (rural group, median value 110; urban group, median value 136) and other causes of death among the workers (median value 158). The quotient between the metals and selenium was used for comparison: a high quotient indicating a low protective effect of selenium and vice versa. The median values of the quotients between antimony, arsenic, cadmium, lanthanum, lead, chromium, and cobalt versus selenium were all numerically higher among the cases of lung cancer, the first five significantly higher (p less than 0.05) in 28 of the 35 comparisons between the lung cancer group and all other groups of smelter workers and controls. The different lung metal concentrations for each person were weighted according to their carcinogenic potency (Crx4 + Asx3 + Cdx2 + Sbx1 + Cox1 + Lax1 + Pbx1) against their corresponding selenium concentrations. From these calculations the protective effect of selenium was even more pronounced. PMID:4041390

  9. Cytotoxicity of selenium nanoparticles in rat dermal fibroblasts

    PubMed Central

    Ramos, Joseph F; Webster, Thomas J

    2012-01-01

    Background: Ventilator-associated pneumonia is a deadly nosocomial infection caused by contaminated endotracheal tubes. It has been shown that polyvinyl chloride (PVC, the endotracheal tube substrate) coated with elemental selenium nanoparticles reduces bacterial adherence and proliferation on PVC by over 99%. However, it is not known if selenium nanoparticles elicit a cytotoxic effect in vitro. The purpose of this study was to investigate the cytotoxic effects of PVC coated with selenium nanoparticles on fibroblasts, which are mammalian cells central to endotracheal tube intubation. Methods: Different concentrations of selenium nanoparticles were precipitated onto the PVC surface by reduction of selenium salts using glutathione. Characterization of PVC coated with selenium nanoparticles was done by scanning electron microscopy, energy dispersive x-ray, and contact angle measurements. For the cytotoxicity experiments, fibroblasts were seeded at a density of 5000 cm2 onto PVC coated with three different concentrations of selenium nanoparticles (high, medium, low) and incubated for 4 hours (adhesion) as well as for 24 hours and 72 hours (proliferation). The half-maximal inhibitory concentration (IC50) value was determined after 72 hours using an ultrahigh concentration. MTT assays were used to assess cell viability at the indicated time points. Results: The three concentrations of selenium nanoparticles did not elicit a cytotoxic effect after 72 hours (P < 0.01, n = 3). It was found that the IC50value was at the ultrahigh concentration of selenium nanoparticles. The nanoparticulate elemental selenium concentration previously shown to decrease the function of bacteria was shown not to cause a cytotoxic effect on fibroblasts in vitro. Conclusion: These findings demonstrate great selectivity between bacteria and healthy cells, and are a viable option for coating endotracheal tubes in order to prevent ventilator-associated pneumonia. PMID:22915842

  10. Strategic Selenium Management: Natural Biofortification of Grazing Livestock with Selenium to Avert Selenium Deficiency and Enhance the Nutritional Value of Food Products.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Efficient and effective management of Se deficiency is required to sustain profitability of grazing-based livestock operations. Selenium deficiency increases morbidity and mortality rates, reduces reproduction rates, and reduces yield and quality of marketable products. Therefore, producers must p...

  11. Cadmium Selenium Testing for Microbial Contaminants

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Cadmium selenium Quantum Dots (QDs) are metal nanoparticles that fluoresce in a variety of colors determined by their size. QDs are solid state structures made of semiconductors or metals that confine a countable, small number of electrons into a small space. The confinement of electrons is achieved by the placement of some insulating material(s) around a central, well conducted region. Coupling QDs with antibodies can be used to make spectrally multiplexed immunoassays that test for a number of microbial contaminants using a single test.

  12. Distinct reactivities on segmented selenium nanorods.

    PubMed

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

    2015-09-18

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

  13. Spectrum of sodiumlike selenium - Se XXIV

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  14. Dosimetric impacts of microgravity: an analysis of 5th, 50th and 95th percentile male and female astronauts

    NASA Astrophysics Data System (ADS)

    Bahadori, Amir A.; Van Baalen, Mary; Shavers, Mark R.; Semones, Edward J.; Bolch, Wesley E.

    2012-02-01

    Computational phantoms serve an important role in organ dosimetry and risk assessment performed at the National Aeronautics and Space Administration (NASA). A previous study investigated the impact on organ dose equivalents and effective doses from the use of the University of Florida hybrid adult male (UFHADM) and adult female (UFHADF) phantoms at differing height and weight percentiles versus those given by the two existing NASA phantoms, the computerized anatomical man (CAM) and female (CAF) (Bahadori et al 2011 Phys. Med. Biol. 56 1671-94). In the present study, the UFHADM and UFHADF phantoms of different body sizes were further altered to incorporate the effects of microgravity. Body self-shielding distributions are generated using the voxel-based ray tracer (VoBRaT), and the results are combined with depth dose data from the NASA codes BRYNTRN and HZETRN to yield organ dose equivalents and their rates for a variety of space radiation environments. It is found that while organ dose equivalents are indeed altered by the physiological effects of microgravity, the magnitude of the change in overall risk (indicated by the effective dose) is minimal for the spectra and simplified shielding configurations considered. The results also indicate, however, that UFHADM and UFHADF could be useful in designing dose reduction strategies through optimized positioning of an astronaut during encounters with solar particle events.

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

    PubMed

    Hamilton, Steven J

    2005-07-01

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

  16. Selenium Nanoparticles for Stress-Resilient Fish and Livestock

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

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

    2015-05-01

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

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

    USGS Publications Warehouse

    Hamilton, Steven J.

    2005-01-01

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

  19. Selenium Nanoparticles for Stress-Resilient Fish and Livestock.

    PubMed

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

    2015-12-01

    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. PMID:26400834

  20. Aquatic selenium pollution is a global environmental safety issue.

    PubMed

    Lemly, A Dennis

    2004-09-01

    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 rainforests, and from the Arctic to the tropics. Human activities that increase waterborne concentrations of selenium are on the rise and the threat of widespread impacts to aquatic life is greater than ever before. Important sources of selenium contamination in aquatic habitats are often overlooked by environmental biologists and ecological risk assessors due to preoccupation with other, higher priority pollutants, yet selenium may pose the most serious long-term risk to aquatic habitats and fishery resources. Failure to include selenium in the list of constituents measured in contaminant screening/monitoring programs is a major mistake, both from the hazard assessment aspect and from the pollution control aspect. Once selenium contamination begins, a cascade of bioaccumulation events is set into motion which makes meaningful intervention nearly impossible. However, this cascade of events need not happen if adequate foresight and planning are exercised. Early evaluation and action are key. Prudent risk management based on environmentally sound hazard assessment and water quality goals can prevent biological impacts. PMID:15261722

  1. Using a Spreadsheet to Compute the Maximum Wind Sector 99.5th Percentile X/Q Value in Accordance with DOE-STD-3009-2014.

    PubMed

    Vickers, Linda

    2016-05-01

    The U.S. Department of Energy Standard 3009-2014 requires one of two methods to determine the simple Gaussian relative concentration (X/Q) of pollutant at plume centerline downwind to a receptor for a 2-h exposure duration from a ground-level release (i.e., less than 10 m height) which are (1) the 99.5th percentile X/Q for the directionally-dependent method and (2) the 95th percentile X/Q for the directionally-independent method. This paper describes how to determine the simple Gaussian 99.5th percentile X/Q for the directionally-dependent method using an electronic spreadsheet. Refer to a previous paper to determine the simple Gaussian 95th percentile X/Q for the directionally-independent method using an electronic spreadsheet (Vickers 2015). The method described herein is simple, quick, accurate, and transparent because all of the data, calculations, and results are visible for validation and verification. PMID:27023153

  2. Bacterial respiration of arsenic and selenium

    USGS Publications Warehouse

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

    1999-01-01

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

  3. Selenium toxicosis in wild aquatic birds.

    PubMed

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

    1988-01-01

    Severe gross and microscopic lesions and other changes were found in adult aquatic birds and in embryos from Kesterson Reservoir (a portion of Kesterson National Wildlife Refuge), Merced County, Calif., during 1984. Adult birds from that area were emaciated, had subacute to extensive chronic hepatic lesions, and had excess fluid and fibrin in the peritoneal cavity. Biochemical changes in their livers included elevated glycogen and non-protein-bound sulfhydryl concentrations and glutathione peroxidase activity but lowered protein, total sulfhydryl, and protein-bound sulfhydryl concentrations. Congenital malformations observed grossly in embryos were often multiple and included anophthalmia, microphthalmia, abnormal beaks, amelia, micromelia, ectrodactyly, and hydrocephaly. Mean concentrations of selenium in livers (94.4 ppm, dry weight) and kidneys (96.6 ppm) of birds collected at the Kesterson ponds were about 10 times those found at a nearby control area (8.3 and 12.2 ppm). We conclude that selenium present in the agricultural drainage water supplied to the Kesterson ponds accumulated in the food chain of aquatic birds to toxic concentrations and caused the lesion and other changes observed. PMID:3373565

  4. Histopathological changes in selenium-exposed fish

    SciTech Connect

    Sorensen, E.M.; Bell, J.S.; Harlan, C.W.

    1983-06-01

    Redear sunfish (Lepomis microlophus) were collected from Martin Lake in east Texas. For at least 8 months, 1 year earlier, aqueous selenium-laden effluent from man-made sources was released into this 5,000-acre reservoir (unpublished data). Redear sunfish from a reference lake, 8 km upstream, were collected for comparison to Martin Lake fish. The hepatopancreas (i.e., liver and associated, disseminated exocrine pancrease), mesonephros (i.e., kidney), gonads, heart, spleen, stomach, and gill arches were preserved for histopathological examination using optical and/or transmission electron microscopy. Livers from Martin Lake redear sunfish (which had accumulated approximately 20 ppm selenium in the liver) showed central necrosis, reduced quantities of rough endoplasmic reticulum and glycogen particles, and increased numbers of lysosome-like structures. Kidneys showed proliferative glomerulonephritis, and exocrine pancreas showed marked hypertrophy at the optical level. Ultrastructurally, architectural disorganization, reduced rough endoplasmic reticulum, increased cisternal space, and proliferation of smooth endoplasmic reticulum were evident. The stomach, spleen, gill, heart, and gonads showed no abnormalities.

  5. Selenium Metabolism in Neptunia amplexicaulis1

    PubMed Central

    Burnell, James N.

    1981-01-01

    ATP sulfurylase (EC 2.7.7.4), cysteinyl-tRNA synthetase (EC 6.1.1.16), and methionyl-tRNA synthetase (EC 6.1.1.10) from Neptunia amplexicaulis have been purified approximately 162-, 140- and 185-fold, respectively. Purified ATP sulfurylase in the presence of purified inorganic pyrophosphatase catalyzed the incorporation of sulfate into adenosine 5′-phosphosulfate; evidence of an analogous reaction with selenate is presented. Crude extracts catalyzed both the sulfate- and the adenosine 5′-phosphosulfate-dependent NADH oxidation in the adenosine 5′-phosphosulfate kinase assay of Burnell and Whatley (1977 Biochim Biophys Acta 481: 266-278), but an analogous reaction with selenate could not be detected. Both purified cysteinyl-tRNA synthetase and methionyl-tRNA synthetase used selenium-containing analogs as substrates in both the ATP-pyrophosphate exchange and the aminoacylation assays. It seems that selenium-containing amino acids are excluded from proteins by a mechanism(s) other than substrate discrimination at the amino acid activation stage of protein synthesis. PMID:16661667

  6. Selenium for the Prevention of Cutaneous Melanoma

    PubMed Central

    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

  7. Selenium toxicosis in wild aquatic birds

    SciTech Connect

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

    1988-01-01

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

  8. Selenium for the prevention of cutaneous melanoma.

    PubMed

    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

    2013-03-01

    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

  9. Selenium and tellurium as carbon substitutes

    SciTech Connect

    Knapp, Jr., F. F.

    1980-01-01

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

  10. Re-evaluation of selenium toxicity in grazing mammals

    SciTech Connect

    Raisbeck, M.F.; O`Toole, D.; Sanchez, D.A.

    1995-09-01

    The potential uptake and concentration of selenium by vegetation grown on abandoned coal mine lands has been the focus of many restrictions governing the reclamation of such sites. While there is little question that selenium is very toxic, recent research suggests that much of what has been anecdotally attributed to selenium in the past, is, in fact, due to other environmental factors. This presentation will summarize research undertaken by the authors during the last 6 years to more clearly define the effects of selenosis on herbivores in Wyoming.

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

    PubMed

    Falandysz, Jerzy

    2003-01-01

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

  12. Transport pathways for arsenic and selenium: A miniriew

    PubMed Central

    Liu, Zijuan

    2009-01-01

    Summary Arsenic and selenium are metalloids found in the environment. Arsenic is considered to pose the most significant potential threat to human health based on frequency of occurrence, toxicity and human exposure. Selenium, on the other hand, ranks only 147th in toxicity but, in contrast to arsenic, is also a required micronutrient. Whether a toxin or micronutrient, their metabolism requires that cells to accumulate these metalloids. In this review we discuss the membrane proteins that transport arsenic and selenium into cells, from bacteria to humans, as well as some the efflux proteins involved in detoxification. PMID:18789529

  13. Percentile Distributions of Median Nitrite Plus Nitrate as Nitrogen, Total Nitrogen, and Total Phosphorus Concentrations in Oklahoma Streams, 1973-2001

    USGS Publications Warehouse

    Haggard, Brian E.; Masoner, Jason R.; Becker, Carol J.

    2003-01-01

    Nutrients are one of the primary causes of water-quality impairments in streams, lakes, reservoirs, and estuaries in the United States. The U.S. Environmental Protection Agency has developed regional-based nutrient criteria using ecoregions to protect streams in the United States from impairment. However, nutrient criteria were based on nutrient concentrations measured in large aggregated nutrient ecoregions with little relevance to local environmental conditions in states. The Oklahoma Water Resources Board is using a dichotomous process known as Use Support Assessment Protocols to define nutrient criteria in Oklahoma streams. The Oklahoma Water Resources Board is modifying the Use Support Assessment Protocols to reflect nutrient informa-tion and environmental characteristics relevant to Oklahoma streams, while considering nutrient information grouped by geographic regions based on level III ecoregions and state boundaries. Percentile distributions of median nitrite plus nitrate as nitrogen, total nitrogen, and total phosphorous concentrations were calculated from 563 sites in Oklahoma and 4 sites in Arkansas near the Oklahoma and Arkansas border to facilitate development of nutrient criteria for Oklahoma streams. Sites were grouped into four geographic regions and were categorized into eight stream categories by stream slope and stream order. The 50th percentiles of median nitrite plus nitrate as nitrogen, total nitrogen, and total phosphorus concentrations were greater in the Ozark Highland ecoregion and were less in the Ouachita Mountains ecoregion when compared to other geographic areas used to group sites. The 50th percentiles of median concentrations of nitrite plus nitrate as nitrogen, total nitrogen, and total phosphorus were least in first, second, and third order streams. The 50th percentiles of median nitrite plus nitrate as nitrogen, total nitrogen and total phosphorus concentrations in the Ozark Highland and Ouachita Mountains ecoregions were least in

  14. Selenium Speciation and Management in Wet FGD Systems

    SciTech Connect

    Searcy, K; Richardson, M; Blythe, G; Wallschlaeger, D; Chu, P; Dene, C

    2012-02-29

    This report discusses results from bench- and pilot-scale simulation tests conducted to determine the factors that impact selenium speciation and phase partitioning in wet FGD systems. The selenium chemistry in wet FGD systems is highly complex and not completely understood, thus extrapolation and scale-up of these results may be uncertain. Control of operating parameters and application of scrubber additives have successfully demonstrated the avoidance or decrease of selenite oxidation at the bench and pilot scale. Ongoing efforts to improve sample handling methods for selenium speciation measurements are also discussed. Bench-scale scrubber tests explored the impacts of oxidation air rate, trace metals, scrubber additives, and natural limestone on selenium speciation in synthetic and field-generated full-scale FGD liquors. The presence and concentration of redox-active chemical species as well as the oxidation air rate contribute to the oxidation-reduction potential (ORP) conditions in FGD scrubbers. Selenite oxidation to the undesirable selenate form increases with increasing ORP conditions, and decreases with decreasing ORP conditions. Solid-phase manganese [Mn(IV)] appeared to be the significant metal impacting the oxidation of selenite to selenate. Scrubber additives were tested for their ability to inhibit selenite oxidation. Although dibasic acid and other scrubber additives showed promise in early clear liquor (sodium based and without calcium solids) bench-scale tests, these additives did not show strong inhibition of selenite oxidation in tests with higher manganese concentrations and with slurries from full-scale wet FGD systems. In bench-tests with field liquors, addition of ferric chloride at a 250:1 iron-to-selenium mass ratio sorbed all incoming selenite to the solid phase, although addition of ferric salts had no impact on native selenate that already existed in the field slurry liquor sample. As ORP increases, selenite may oxidize to selenate more

  15. Defining the Optimal Selenium Dose for Prostate Cancer Risk Reduction: Insights from the U-Shaped Relationship Between Selenium Status, DNA Damage, and Apoptosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our work in dogs has revealed a U-shaped dose response between selenium status and prostatic DNA damage that remarkably parallels the relationship between dietary selenium and prostate cancer risk in men, suggesting that more selenium is not necessarily better. Herein, we extend this canine work to ...

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

    SciTech Connect

    Davidson, W.B.; McMurray, C.H.

    1988-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  18. Selenium and Mercury in the Brazilian Amazon: Opposing Influences on Age-Related Cataracts

    PubMed Central

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

    2010-01-01

    Background Age-related cataracts (ARCs) are an important cause of blindness in developing countries. Although antioxidants may be part of the body’s defense to prevent ARC, environmental contaminants may contribute to cataractogenesis. In fish-eating populations of the lower Tapajós region, elevated exposure to mercury (Hg) has been reported, and blood levels of selenium (Se) range from normal to very high (> 1,000 μg/L). Objectives We examined ARCs in relation to these elements among adults (≥ 40 years of age) from 12 riverside communities. Methods Participants (n = 211) provided blood samples and underwent an extensive ocular examination. Inductively coupled plasma mass spectrometry was used to assess Hg and Se in blood and plasma. Results One-third (n = 69; 32.7%) of the participants had ARC. Lower plasma Se (P-Se; < 25th percentile, 110 μg/L) and higher blood Hg (B-Hg; ≥ 25th percentile, 25 μg/L) were associated with a higher prevalence odds ratio (POR) of ARC [adjusted POR (95% confidence interval), 2.69 (1.11–6.56) and 4.45 (1.43–13.83), respectively]. Among participants with high P-Se, we observed a positive but nonsignificant association with high B-Hg exposure, whereas among those with low B-Hg, we observed no association for P-Se. However, compared with the optimum situation (high P-Se, low B-Hg), the POR for those with low P-Se and high B-Hg was 16.4 (3.0–87.9). This finding suggests a synergistic effect. Conclusion Our results suggest that persons in this population with elevated Hg, the cataractogenic effects of Hg may be offset by Se. Because of the relatively small sample size and possible confounding by other dietary nutrients, additional studies with sufficient power to assess multiple nutrient and toxic interactions are required to confirm these findings. PMID:20716509

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

    PubMed

    Yanardağ, R; Orak, H

    1999-04-01

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

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

    PubMed Central

    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

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

    SciTech Connect

    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.

  2. Behavior of mallard ducklings from adults exposed to selenium

    USGS Publications Warehouse

    Heinz, G.H.; Gold, L.G.

    1987-01-01

    Pairs of adult mallards (Anas platyrhynchos) were fed a control diet or a diet containing 1, 2, 4 or 8 ppm selenium in the form of seleno-DL-methionine. Ducklings from these pairs were fed an untreated diet from hatching through 6 d of age, at which time their avoidance of a fright stimulus was tested. Selenium had no effect on the ducklings' response to the fright stimulus.

  3. Selenium in the Blackfoot, Salt, and Bear river watersheds.

    PubMed

    Hamilton, S J; Buhl, K J

    2005-05-01

    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 microg/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 microg/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 eleated in several ecosystem components to cause adverse effects to aquatic resources in southeastern Idaho. PMID:15931994

  4. Selenium suppresses leukemia through the action of endogenous eicosanoids.

    PubMed

    Gandhi, Ujjawal H; Kaushal, Naveen; Hegde, Shailaja; Finch, Emily R; Kudva, Avinash K; Kennett, Mary J; Jordan, Craig T; Paulson, Robert F; Prabhu, K Sandeep

    2014-07-15

    Eradicating cancer stem-like cells (CSC) may be essential to fully eradicate cancer. Metabolic changes in CSC could hold a key to their targeting. Here, we report that the dietary micronutrient selenium can trigger apoptosis of CSC derived from chronic or acute myelogenous leukemias when administered at supraphysiologic but nontoxic doses. In leukemia CSC, selenium treatment activated ATM-p53-dependent apoptosis accompanied by increased intracellular levels of reactive oxygen species. Importantly, the same treatment did not trigger apoptosis in hematopoietic stem cells. Serial transplantation studies with BCR-ABL-expressing CSC revealed that the selenium status in mice was a key determinant of CSC survival. Selenium action relied upon the endogenous production of the cyclooxygenase-derived prostaglandins Δ(12)-PGJ2 and 15d-PGJ2. Accordingly, nonsteroidal anti-inflammatory drugs and NADPH oxidase inhibitors abrogated the ability of selenium to trigger apoptosis in leukemia CSC. Our results reveal how selenium-dependent modulation of arachidonic acid metabolism can be directed to trigger apoptosis of primary human and murine CSC in leukemia. PMID:24872387

  5. Reproduction in eastern screech-owls fed selenium

    USGS Publications Warehouse

    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 < 0.05) relative to controls. Parents given 4.4 ppm selenium produced no malformed nestlings, but femur lengths of young were shorter (P = 0.015) than those of controls. Liver 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).

  6. Nuclear-based methods for the study of selenium

    SciTech Connect

    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.

  7. Selenium in the environment, metabolism and involvement in body functions.

    PubMed

    Mehdi, Youcef; Hornick, Jean-Luc; Istasse, Louis; Dufrasne, Isabelle

    2013-01-01

    Selenium (Se³⁴₇₉) is a metalloid which is close to sulfur (S) in terms of properties. The Se concentration in soil varies with type, texture and organic matter content of the soil and with rainfall. Its assimilation by plants is influenced by the physico-chemical properties of the soil (redox status, pH and microbial activity). The presence of Se in the atmosphere is linked to natural and anthropogenic activities. Selenoproteins, in which selenium is present as selenocysteine, present an important role in many body functions, such as antioxidant defense and the formation of thyroid hormones. Some selenoprotein metabolites play a role in cancer prevention. In the immune system, selenium stimulates antibody formation and activity of helper T cells, cytotoxic T cells and Natural Killer (NK) cells. The mechanisms of intestinal absorption of selenium differ depending on the chemical form of the element. Selenium is mainly absorbed in the duodenum and caecum by active transport through a sodium pump. The recommended daily intake of selenium varies from 60 μg/day for women, to 70 μg/day for men. In growing ruminants the requirements are estimated at 100 μg/kg dry matter and 200 μg/Kg for pregnant or lactating females. A deficiency can cause reproductive disorders in humans and animals. PMID:23486107

  8. Electronic states and stability of selenium clusters

    NASA Astrophysics Data System (ADS)

    Li, Z. Q.; Yu, J. Z.; Ohno, K.; Gu, B. L.; Czajka, R.; Kasuya, A.; Nishina, Y.; Kawazoe, Y.

    1995-07-01

    Electronic structures and stability of Sen (n=3,4,5,6,7,8) clusters have been studied by using the discrete variational method in the framework of the local-density approximation. Binding energy, ionization potential, affinity energy, and other electronic properties using the structure models of Hohl et al. [Chem. Phys. Lett. 139, 540 (1987)] are presented and compared with the available experiments. In addition, a rectangular lattice arrangement of selenium clusters has been fabricated on highly oriented pyrolytic graphite, and examined by the scanning tunnel microscope image which was found to consist of a 0.72×0.85 nm2 lattice spacing with individual molecules of 0.53+/-0.05 nm in diameter. Theoretical calculations reproduce well the experimental observations.

  9. Controlled introduction of selenium into Chlorella cells.

    PubMed

    de Alcantara, S; Lopes, C C; Wagener, K

    1998-12-01

    Selenium (Se) is an important element in the antioxidant system of the human body, and Chlorella, well-known for its therapeutic effects, is the ideal carrier to offer it in the wanted organic form. The kinetics of Se absorption by growing algal cells and its distribution in the cells are studied using radioactive 75Se labelled solutions. There is a rapid Se absorption within the first few minutes at the cell surfaces where it is irreversibly fixed and cannot be absorbed by the human body. In the final state, reached after 24-48 hr, about 40% of the total fixed Se is inside the cells in the wanted organic-bound form. PMID:10093514

  10. Plant selenium from soil and the atmosphere

    SciTech Connect

    Haygarth, P.M.; Jones, K.C.; Harrison, A.F.

    1995-07-01

    Transfer of selenium (Se) to pasture is important for prevention of Se deficiency in livestock, yet little is known about the relative importance of inputs to pasture from soil and the atmosphere. An isotope dilution method was used to assess quantitatively the importance of these inputs to ryegrass. Soil was labelled with {sup 75}Se and subjected to two field treatments that were untreated (pH 6.0) and limed (pH 7.0). After an initial period of equilibration, the specific activity of Se associated with unwashed leaves became lower than that of soil. This indicated that atmospheric Se had been deposited onto and possibly incorporated into the ryegrass. The percent contribution of {sup 75}Se in pasture leaves derived from the soil was 47% (pH 6.0) and 70% (pH 7.0), with, by inference, the remainder coming from the atmosphere. 23 refs., 1 fig., 4 tabs.

  11. The evolving versatility of selenium in biology.

    PubMed

    Brigelius-Flohé, Regina

    2015-10-01

    This editorial shortly summarizes the highlights described in the Forum, novelties about selenoproteins. Two articles describe the selenoprotein biosynthesis and the role of so far identified proteins involved, including that of selenocysteine-β-lyase, which also may link selenoproteins to energy metabolism. Novel and, in part, unexpected functions are reviewed. Thioredoxin reductase 1 (TrxR1) can change from an anti- to a pro-oxidant and appears to be involved in the regulation of the Nrf2/Keap1 system. Methionine sulfoxide reductase B1 (MsrB1) catalyzes a novel posttranslational protein modification. The membrane proteins, Sel K,S,T,N, and I, form selenylsulfide bonds leading to the formation and stabilization of protein complexes required for protein trafficking. By this mechanism, selenoprotein K (SelK) supports palmitoylation of membrane-associated proteins. Thus, selenium and selenoproteins obviously have functions by far exceeding that of counteracting oxidative stress and even also catalyzing oxidoreductive processes. PMID:26406357

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

    PubMed

    Pedersen, K B; Simesen, M G

    1977-01-01

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

  13. Selenium Uptake and Volatilization by Marine Algae

    NASA Astrophysics Data System (ADS)

    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

  14. A bacterial process for selenium nanosphere assembly

    PubMed Central

    Debieux, Charles M.; Dridge, Elizabeth J.; Mueller, Claudia M.; Splatt, Peter; Paszkiewicz, Konrad; Knight, Iona; Florance, Hannah; Love, John; Titball, Richard W.; Lewis, Richard J.; Richardson, David J.; Butler, Clive S.

    2011-01-01

    During selenate respiration by Thauera selenatis, the reduction of selenate results in the formation of intracellular selenium (Se) deposits that are ultimately secreted as Se nanospheres of approximately 150 nm in diameter. We report that the Se nanospheres are associated with a protein of approximately 95 kDa. Subsequent experiments to investigate the expression and secretion profile of this protein have demonstrated that it is up-regulated and secreted in response to increasing selenite concentrations. The protein was purified from Se nanospheres, and peptide fragments from a tryptic digest were used to identify the gene in the draft T. selenatis genome. A matched open reading frame was located, encoding a protein with a calculated mass of 94.5 kDa. N-terminal sequence analysis of the mature protein revealed no cleavable signal peptide, suggesting that the protein is exported directly from the cytoplasm. The protein has been called Se factor A (SefA), and homologues of known function have not been reported previously. The sefA gene was cloned and expressed in Escherichia coli, and the recombinant His-tagged SefA purified. In vivo experiments demonstrate that SefA forms larger (approximately 300 nm) Se nanospheres in E. coli when treated with selenite, and these are retained within the cell. In vitro assays demonstrate that the formation of Se nanospheres upon the reduction of selenite by glutathione are stabilized by the presence of SefA. The role of SefA in selenium nanosphere assembly has potential for exploitation in bionanomaterial fabrication. PMID:21808043

  15. Comparison of selenium distribution in mice organs after the supplementation with inorganic and organic selenium compound selenosemicarbazide.

    PubMed

    Musik, Irena; Kozioł-Montewka, Maria; Toś-Luty, Sabina; Donica, Helena; Pasternak, Kazimierz; Wawrzycki, Sławomir

    2002-01-01

    Studies on selenium organ content and its function in living organisms just like studies on other elements provide interesting results although their interpretation is not always clear. The aim of our study was to determine the concentration and distribution of selenium in several organs and tissues in mice after supplementation with our newly synthesized organic compound of selenium selenosemicarbazide (4-o-tolyl-selenosemicarbazide of o-chlorobenzoic acid) as compared to the effects of the supplementation with inorganic compounds. SWISS mice were fed with both types of compounds at the dose of 10(-3) g Se per kg for the period of 10 days. The concentrations of selenium in brains of mice treated with selenocarbazide and sodium selenite were higher than in controls (38.04 micrograms g-1 and 32.00 micrograms g-1 vs. 26.18 micrograms g-1). There was a statistically significant increase in the selenium contents in lungs after supplementation with selenosemicarbazide and sodium selenite (11.81 micrograms g-1 and 6.79 micrograms g-1 vs. 1.75 micrograms g-1 in controls). We found a statistically insignificant increase in selenium contents in intercostal muscles after supplementation with inorganic selenium compounds and a statistically significant increase after the supplementation with selenosemicarbazide (10.13 micrograms g-1; 14.21 micrograms g-1 and 28.84 micrograms g-1, respectively). Our investigations lead to a conclusion that 4-o-tolyl-seleno-semicarbazide of o-chlorobenzoic acid, an organic selenium compound may be more easily absorbed than inorganic sodium IV selenite. PMID:12898900

  16. Bioactivity of selenium from Brazil nut for cancer prevention and selenoenzyme maintenance.

    PubMed

    Ip, C; Lisk, D J

    1994-01-01

    Brazil nut (Bertholletia excelsa) is one of very few consumable products with exceptionally high levels of selenium. The mean selenium concentrations of two shipments of Brazil nut used in the present study were determined to be 16 and 30 micrograms/g. In contrast, most common foods contain much less selenium, from 0.01 to 1 micrograms/g. Previous research on selenium cancer chemoprevention invariably used a pure compound, whereas little information is available on the efficacy of selenium delivered naturally in a food form. This paper reports the results of two mammary cancer prevention experiments in the rat dimethylbenz[a]anthracene model by continuous feeding of selenium-rich Brazil nut (processed to a smooth-textured nut material for mixing in the diet). A dose-dependent inhibitory response was observed at dietary selenium concentrations of 1-3 micrograms/g. Interestingly, Brazil nut was found to be just as powerful as sodium selenite, if not more so, at similar levels of dietary selenium intake. Mammary cancer protection gland, and plasma. The magnitude of tissue selenium accumulation was proportional to the amount of Brazil nut added to the diet. The nutritional biopotency of selenium in Brazil nut was also evaluated by the repletion of two selenoenzymes, glutathione peroxidase and type I 5'-deiodinase, in selenium-deficient rats. Supplementation with Brazil nut as the sole source of selenium produced an efficient gradient of enzyme restoration at 0.05-0.2 microgram/g of dietary selenium. A parallel comparison with sodium selenite indicated that the selenium in Brazil nut and selenite selenium were equally bioactive. Although at this point it can only be inferred that the above biologic effects are likely to be attributable to the high selenium content of Brazil nut, there is persuasive evidence to suggest that the models under investigation are responding to the selenium rather than to the other components of Brazil nut. PMID:8072875

  17. Defining the Optimal Selenium Dose for Prostate Cancer Risk Reduction: Insights from the U-Shaped Relationship between Selenium Status, DNA Damage, and Apoptosis.

    PubMed

    Chiang, Emily C; Shen, Shuren; Kengeri, Seema S; Xu, Huiping; Combs, Gerald F; Morris, J Steven; Bostwick, David G; Waters, David J

    2009-01-01

    Our work in dogs has revealed a U-shaped dose response between selenium status and prostatic DNA damage that remarkably parallels the relationship between dietary selenium and prostate cancer risk in men, suggesting that more selenium is not necessarily better. Herein, we extend this canine work to show that the selenium dose that minimizes prostatic DNA damage also maximizes apoptosis-a cancer-suppressing death switch used by prostatic epithelial cells. These provocative findings suggest a new line of thinking about how selenium can reduce cancer risk. Mid-range selenium status (.67-.92 ppm in toenails) favors a process we call "homeostatic housecleaning"-an upregulated apoptosis that preferentially purges damaged prostatic cells. Also, the U-shaped relationship provides valuable insight into stratifying individuals as selenium-responsive or selenium-refractory, based upon the likelihood of reducing their cancer risk by additional selenium. By studying elderly dogs, the only non-human animal model of spontaneous prostate cancer, we have established a robust experimental approach bridging the gap between laboratory and human studies that can help to define the optimal doses of cancer preventives for large-scale human trials. Moreover, our observations bring much needed clarity to the null results of the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and set a new research priority: testing whether men with low, suboptimal selenium levels less than 0.8 ppm in toenails can achieve cancer risk reduction through daily supplementation. PMID:20877485

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

    PubMed

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

    2014-09-01

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

  19. Association of selenium status and blood glutathione concentrations in blacks and whites

    PubMed Central

    Richie, John P.; Muscat, Joshua E.; Ellison, Irina; Calcagnotto, Ana; Kleinman, Wayne; El-Bayoumy, Karam

    2011-01-01

    Selenium deficiency has been linked with increased cancer risk and, in some studies, selenium supplementation was protective against certain cancers. Previous studies suggest that selenium chemoprevention may involve reduced oxidative stress through enhanced glutathione (GSH). Our objectives were to examine the relationships between selenium and GSH in blood and modifying effects of race and sex in free living adults and individuals supplemented with selenium. Plasma selenium concentrations and free and bound GSH concentrations and γ-glutamyl cysteine ligase (GCL) activity in blood were measured in 336 healthy adults, (161 blacks, 175 whites). Plasma selenium and blood GSH were also measured in 36 healthy men from our previously conducted placebo-controlled trial of selenium-enriched yeast (247 μg/day for 9 months). In free-living adults, selenium concentrations were associated with increased blood GSH concentration and GCL activity (P<0.05). Further, selenium was significantly higher in whites than in blacks (P<0.01). After 9 months of supplementation, plasma selenium was increased 114% in whites and 50% in blacks (P<0.05) and blood GSH was increased 35% in whites (P<0.05) but was unchanged in blacks. These results indicate a direct association between selenium and GSH in blood of both free-living and selenium-supplemented individuals, with race being an important modifying factor. PMID:21462082

  20. Green synthesis and structural characterization of selenium nanoparticles and assessment of their antimicrobial property.

    PubMed

    Srivastava, Nishant; Mukhopadhyay, Mausumi

    2015-09-01

    In the present study, selenium nanoparticles were biologically synthesized by non-pathogenic, economic and easy to handle bacterium Ralstonia eutropha. The selenium oxo anion was reduced to selenium nanoparticles in the presence of the bacterium. The bacterium was grown aerobically in the reaction mixture. An extracellular, stable, uniform, spherical selenium nanoparticle was biosynthesized. The TEM analysis revealed that the biosynthesized selenium nanoparticles were spherical in shape with size range of 40-120 nm. XRD and SAED analysis showed that nanocrystalline selenium of pure hexagonal phase was synthesized. The formation of actinomorphic trigonal selenium nanorods was also observed. A mechanism of biosynthesis of selenium nanoparticles by R. eutropha was proposed. The biosynthesized selenium nanoparticles were investigated for their antimicrobial activity against potential pathogens. Selenium nanoparticles showed excellent antimicrobial activity. The 100, 100, 250 and 100 µg/ml selenium nanoparticles were found to inhibit 99 % growth of Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Streptococcus pyogenes, respectively. Similarly, the 500 µg/ml of selenium nanoparticles was found to inhibit the growth of pathogenic fungi Aspergillus clavatus. The antimicrobial efficacy of selenium nanoparticle was comparable with commercially available antibiotic drug Ampicillin. PMID:25972036

  1. Characterization of selenium in the lower Gunnison River basin, Colorado, 1988-2000

    USGS Publications Warehouse

    Butler, David L.; Leib, Kenneth J.

    2002-01-01

    Selenium concentrations in certain water bodies in the lower Gunnison River Basin, including the lower Gunnison River and lower Uncompahgre River, have exceeded the Colorado water-quality standard of 5 micrograms per liter for selenium. A task force was formed in 1998 that consists of various government agencies, private irrigation companies, and local residents to address the selenium concerns in the lower Gunnison River Basin. The task force, working with the National Irrigation Water Quality Program, needed more detailed information on selenium loading in the basin to develop viable alternatives for remediating selenium in the lower Gunnison River Basin. In 1999-2000, the U.S. Geological Survey collected selenium data for tributaries of the Gunnison River downstream from the North Fork of the Gunnison and in the North Fork Basin. The largest selenium load in a tributary stream was in the Uncompahgre River, which accounted for about 38 percent of the selenium load in the Gunnison River at Whitewater. The North Fork of the Gunnison River accounted for about 7 percent of the selenium load in the Gunnison River. Two tributaries east of Delta, Sunflower Drain and Bonafide Ditch, consist primarily of irrigation return flows and were other major selenium sources to the Gunnison River. Some tributaries in the lower North Fork Basin had selenium concentrations exceeding 5 micrograms per liter. Except for several streams draining the Uncompahgre Plateau, many tributaries to the Gunnison River downstream from the North Fork had selenium concentrations exceeding 5 micrograms per liter. Except during occasional rain and snowmelt events, selenium loading from nonirrigated desert areas was minimal. Detailed characterization studies were done in 1999-2000 on Cedar Creek and Loutzenhizer Arroyo, which contribute the largest tributary selenium loads to the Uncompahgre River. Selenium concentrations in Cedar Creek downstream from Miguel Road ranged from 12 to 28 micrograms per

  2. Loss of Selenium-Binding Protein 1 Decreases Sensitivity to Clastogens and Intracellular Selenium Content in HeLa Cells.

    PubMed

    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. PMID:27404728

  3. Loss of Selenium-Binding Protein 1 Decreases Sensitivity to Clastogens and Intracellular Selenium Content in HeLa Cells

    PubMed Central

    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. PMID:27404728

  4. Low selenium status in the elderly influences thyroid hormones.

    PubMed

    Olivieri, O; Girelli, D; Azzini, M; Stanzial, A M; Russo, C; Ferroni, M; Corrocher, R

    1995-12-01

    1. Iodothyronine 5'-deiodinase, which is mainly responsible for peripheral triiodothyronine (T3) production, has recently been demonstrated to be a selenium-containing enzyme. In the elderly, reduced peripheral conversion of thyroxine (T4) to T3 and overt hypothyroidism are frequently observed. 2. We measured serum selenium and erythrocyte glutathione peroxidase (as indices of selenium status), thyroid hormones and thyroid-stimulating hormone in 109 healthy euthyroid subjects (52 women, 57 men), carefully selected to exclude abnormally low thyroid hormone levels induced by acute or chronic diseases or calorie restriction. The subjects were subdivided into three age groups. To avoid conditions of under-nutrition or malnutrition, dietary records were obtained for a sample of 24 subjects, randomly selected and representative of the whole population for age and sex. 3. In order to properly assess the influence of selenium status on iodothyronine 5'-deiodinase type I activity, a double-blind placebo-controlled trial was also carried out on 36 elderly subjects, resident at a privately owned nursing home. 4. In the free-living population, a progressive reduction of the T3/T4 ratio (due to increased T4 levels) and of selenium and erythrocyte glutathione peroxidase activity was observed with advancing age. A highly significant linear correlation between T4, T3/T4 and selenium was observed in the population as a whole (for T4, R = -0.312, P < 0.002; for T3/T4 ratio, R = 0.32, P < 0.01) and in older subjects (for T4, R = -0.40, P < 0.05; for T3/T4 ratio, R = 0.54, P < 0.002). 5. The main result of the double-blind placebo-controlled trial was a significant improvement of selenium indices and a decrease in the T4 level in selenium-treated subjects; serum selenium, erythrocyte glutathione peroxidase activity and thyroid hormones did not change in placebo-treated subjects. 6. We concluded that selenium status influences thyroid hormones in the elderly, mainly modulating T4

  5. Determination of selenium and its compounds in marine organisms.

    PubMed

    Bryszewska, Małgorzata Anita; Måge, Amund

    2015-01-01

    In this study, we investigate the type and quantity of selenium compounds in fish and marine organisms, using ion-pair reversed phase LC–ICP-MS, developed and applied for the analysis of Atlantic cod, Atlantic salmon, Greenland halibut, Atlantic herring, blue mussel, common crab, scallop, calanus, and Euphasia super. Of the samples examined, the lowest level of selenium was found in farmed Atlantic salmon (0.17 mg Se kg(−1) dm). The total selenium extraction efficiency by phosphate buffer was 2.5 times higher in sea plankton and shellfish samples than in fish samples. Analysis of Se species in each hydrolysate obtained by proteolysis showed the presence of selenomethionine, which constituted 41.5% of the selenium compounds detected in hydrolysates of Atlantic herring and 98.4% of those in extracts of Atlantic salmon. Inorganic compounds, such as selenates and selenites, were detected mainly in sea plankton and shellfish samples (<0.13 mg Se kg(−1) wm), although no correlation was found between the presence of inorganic compounds and total selenium concentration. The accuracy of the total selenium determination was validated using a certified reference material (oyster tissue (NIST 1566b)). A lyophilised powder of cod (Gadus morhua) was used to validate speciation analysis, enzymatic hydrolysis of lyophilised powder of cod recovered 54 ± 6% of total selenium, and SeMet constituted 83.5 ± 5.28% of selenium detected in hydrolysates. The chromatographic detection limits were, respectively, 0.30 ng mL(−1), 0.43 ng mL(−1), 0.54 ng mL(−1), 0.55 ng mL(−1), 0.57 ng mL(−1) and 0.72 ng mL(−1) for selenate, selenomethionine, selenite, Se-methyl-selenocysteine, selenocystine and selenomethionine selenoxide.The data on selenium concentrations and speciation presented here could be useful in estimating levels of selenium intake by seafood consumption. PMID:25468190

  6. Selenium pollution: Occurrence and environmental fate. (Latest citations from Pollution abstracts). Published Search

    SciTech Connect

    1997-05-01

    The bibliography contains citations concerning sources and abatement of pollution caused by selenium and selenium compounds. The citations examine the effects of selenium on the reproductive success of birds and fish, uptake of selenium in plants, and bioaccumulation in the food chain. Other topics include selenium chemistry and persistence in soil, water, and the atmosphere; the relative toxicities of selenium and selenium compounds; and decontamination of polluted environments. Special attention is given to agricultural effluent as a source of selenium pollution and to the development of long-term monitoring programs to determine the rate at which pollution declines.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

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

    SciTech Connect

    Kuzmin, P G; Shafeev, Georgii A; Voronov, Valerii V; Raspopov, R V; Arianova, E A; Trushina, E N; Gmoshinskii, I V; Khotimchenko, S A

    2012-11-30

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

  8. SELENIUM TREATMENT/REMOVAL ALTERNATIVES DEMONSTRATION PROJECT - MINE WASTE TECHNOLOGY PROGRAM ACTIVITY III, PROJECT 20

    EPA Science Inventory

    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...

  9. Selenium pollution: Occurrence and environmental fate. (Latest citations from Pollution abstracts). Published Search

    SciTech Connect

    Not Available

    1994-09-01

    The bibliography contains citations concerning sources and abatement of pollution caused by selenium and selenium compounds. The citations examine the effects of selenium on the reproductive success of birds and fish, uptake of selenium in plants, and bioaccumulation in the food chain. Other topics include selenium chemistry and persistence in soil, water, and the atmosphere; the relative toxicities of selenium and selenium compounds; and decontamination of polluted environments. Special attention is given to agricultural effluent as a source of selenium pollution and to the development of long-term monitoring programs to determine the rate at which pollution declines. (Contains a minimum of 143 citations and includes a subject term index and title list.)

  10. Reduction of selenate and selenite to elemental selenium by a Pseudomonas stutzeri isolate

    SciTech Connect

    Lortie, L.; Gould, W.D.; Rajan, S. ); McCready, R.G.L. ); Cheng, K.J. )

    1992-12-01

    Agricultural drainage, smelter effluents, fly ash, sewage sludge, and gases from fossil fuel burning are all sources of selenium. Some selenium compounds are toxic, but selenium is also an essential nutrient. This study characterizes a Pseudomonas stutzeri isolate capable of reducing the selenate ion to elemental selenium and evaluates the effects of selenium concentration, temperature, and pH on selenium reduction. Reduction increased with increasing concentration up to 19.0 mM; little or no reduction occurred below pH 5.5 or above pH 9.5; optimum reduction temperature was 25-30[degree]C. There appears to be no evidence for dissimilatory selenium reduction so the reductive pathway in this organism may function as a system for detoxification of selenium oxyanions.

  11. Treating chronic arsenic toxicity with high selenium lentil diets

    SciTech Connect

    Sah, Shweta; Vandenberg, Albert; Smits, Judit

    2013-10-01

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

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

    PubMed

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

    1987-10-01

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

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

    PubMed

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

    1997-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Martínez, M.; Giménez, J.; de Pablo, J.; Rovira, M.; Duro, L.

    2006-03-01

    In this work, we have studied the sorption of selenium ( 79Se is one of the main radionuclides in a spent nuclear fuel repository) on magnetite (Fe 3O 4), a mineral present in the near-field of a nuclear waste repository that might represent an important retardation factor for the mobility of many radionuclides. The sorption of both Se(IV) and Se(VI) onto magnetite has been fitted by a non-competitive Langmuir isotherm with Γmax = (3.13 ± 0.07) × 10 -6 mol m -2 and KL = (1.19 ± 0.07) × 10 6 dm 3 mol -1 for Se(IV) and Γmax = (3.5 ± 0.2) × 10 -6 mol m -2 and KL = (3.0 ± 0.1) × 10 5 dm 3 mol -1 for Se(VI). The variation of the sorption of selenium with pH has been modeled using the Triple Layer Surface Complexation Model and the equilibrium constants between selenium and magnetite have been obtained using the FITEQL program. For the case of Se(IV), the best fitting has been obtained using two inner-sphere complexes, lbond2 FeOHSeO 32- and lbond2 FeHSeO 3, while for Se(VI), the best fitting has been obtained considering only an outer-sphere complex, lbond2 FeOH 2+sbnd SeO 42-. The surface complexation reactions derived in this work are in agreement with those stated by other authors for sorption of Se(IV) and Se(VI) on hydrous iron oxides.

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

    PubMed Central

    Hamre, Kristin; Ellingsen, Ståle

    2015-01-01

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

  16. Effect of subcutaneous selenium injection and supplementary selenium source on blood selenium and glutathione peroxidase in feedlot heifers

    PubMed Central

    Chorfi, Younes; Girard, Vincent; Fournier, Alain; Couture, Yvon

    2011-01-01

    This study measured the effect on glutathione peroxidase (GSH-Px) and selenium (Se) in whole blood and plasma associated with subcutaneous Se injections in beef heifers fed organic or inorganic Se. Heifers (n = 120) were randomly divided into 2 groups, 1 of which received subcutaneous Se injections. Both groups were given the same total mixed ration with 3 mg of organic or inorganic Se daily. Until week 2, heifers that had received Se injections showed higher concentrations of plasma Se and GSH-Px and whole blood Se (P < 0.001) than those having had no injections. Concentrations of plasma Se and GSH-Px were higher in the group receiving organic Se than the group receiving inorganic Se. Whole blood GSH-Px concentrations increased significantly (P < 0.001) throughout a 12-week period but were not affected by Se source. Combination of Se injections and supplementation could help maintain normal Se and GSH-Px blood status in beef heifers during the first few weeks in the feedlot. PMID:22467963

  17. Involvement of a broccoli COQ5 methyltransferase in the production of volatile selenium compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium plays an indispensable role in human nutrition and health, but becomes toxic at higher concentrations. Therefore, selenium volatilization is of great interest because it provides important means for cleanup of selenium polluted environments. To identify novel genes whose products are involv...

  18. Speciation of selenium in stream insects using X-ray absorption spectroscopy

    SciTech Connect

    Ruwandi Andrahennadi; Mark Wayland; Ingrid J. Pickering

    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.

  19. Speciation of Selenium in Stream Insects Using X-Ray Absorption Spectroscopy

    SciTech Connect

    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.

  20. Isotopic Fractionation of Selenium Oxyanions in Wetlands

    NASA Astrophysics Data System (ADS)

    Clark, S. K.; Johnson, T. M.

    2004-05-01

    As oxic surface waters pass through aquatic macrophytes and over anoxic sediments in wetlands and lakes, the dissolved Se load often decreases; and, Se isotope ratio measurements can provide information about the mechanisms involved. Previous work on microbially induced isotopic fractionation of Se oxyanions under nearly natural conditions using wetland sediments shows consistent Se isotopic shifts during reduction of Se(VI) and Se(IV) to insoluble Se(0). However, previous isotopic studies of total dissolved selenium in wetlands found little to no isotopic shift as dissolved selenium concentrations decreased. This suggests that plant/algal uptake, followed by deposition and degradation, is the primary route of Se transfer into sediments. However, it is possible that the effective isotopic fractionation between Se in the surface water and Se deposited into sediments is somehow much less than the fractionation induced by the reduction reaction, or that cycling of organically bound Se is involved. In this study, we report Se isotope data for Se(VI), Se(IV) and total dissolved Se, Se(T), in surface waters from three wetland/lake sites: Sweitzer Lake, CO; 33-Mile Reservoir, WY; and, a small pond adjacent to Benton Lake, MT. We isolated Se(IV) via hydride generation, and Se(VI) via ion exchange. Se(T), including any organic components, was also analyzed. Isotope analysis was performed on an Isoprobe MC-ICPMS, using a method modified from that of Rouxel et al. (2002). We used the 82Se + 74Se double spike approach, and spiked samples before species separation. Our results for all three locations indicate similar trends in concentration changes and isotopic shifts between the inflow and outflow waters. Se(T) concentrations decrease by 45-70%, and Se(VI) concentrations decrease by 60-90%, whereas Se(IV) concentrations increase by 60-150%. Concomitant 80Se/76Se shifts are +0.5-0.8‰ for Se(T); -0.1-0.5‰ for Se(VI); and +0.4-6.5‰ for Se(IV). These data provide greater

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

    NASA Astrophysics Data System (ADS)

    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

  2. Hydrological and geochemical investigations of selenium behavior at Kesterson Reservoir

    SciTech Connect

    Benson, S.M.; Tokunaga, T.K.; Zawislanski, P.; Yee, A.W.; Daggett, J.S.; Oldfather, J.M.; Tsao, L.; Johannis, P.W.

    1990-10-01

    From 1985 to the present we have studied the behavior of selenium in various habitats and environments at Kesterson reservoir, shifting emphasis as remedial actions altered the physical setting. Investigations have evaluated the efficacy of several remedial alternatives, from innovative techniques relying on the complex geochemical behavior of selenium alternatives, from innovative techniques relying on the complex geochemical behavior of selenium in aquatic environments to conventional excavation schemes. Results of these studies supported two cost-effective remedial measures; drain water deliveries were terminated in 1986 and, in 1988, 1 million cubic yards of soil were imported and used to fill the low lying areas of the former Kesterson Reservoir. To date, these two actions appear to have eliminated the aquatic habitat that caused waterfowl death and deformity at Kesterson from the early 1980's to 1987. Biological, surface water and groundwater monitoring data collected by the USBR indicate that Kesterson is now a much safer environment than in past years when drainage water containing 300{mu}g/l of selenium was delivered to the Reservoir. The continued presence of a large inventory of selenium within the upper portions of unfilled areas of Kesterson Reservoir and immediately below the fill material requires that a continued awareness of the status of this inventory be maintained and improved upon. 83 refs., 130 figs., 19 tabs.

  3. Think outside of the box: selenium volatilization altered by a broccoli gene in the ubiquinone biosynthetic pathway

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium metabolism has been an area of active research because of the essentiality as well as toxicity of selenium to animals and humans. Biologically based selenium volatilization has been a particular area of interest for its potential in making detoxification of selenium pollution highly effecti...

  4. Antioxidant and cytotoxic effect of biologically synthesized selenium nanoparticles in comparison to selenium dioxide.

    PubMed

    Forootanfar, Hamid; Adeli-Sardou, Mahboubeh; Nikkhoo, Maryam; Mehrabani, Mitra; Amir-Heidari, Bagher; Shahverdi, Ahmad Reza; Shakibaie, Mojtaba

    2014-01-01

    The present study was designed to evaluate antioxidant and cytotoxic effect of selenium nanoparticles (Se NPs) biosynthesized by a newly isolated marine bacterial strain Bacillus sp. MSh-1. An organic-aqueous partitioning system was applied for purification of the biogenic Se NPs and the purified Se NPs were then investigated for antioxidant activity using DPPH scavenging activity and reducing power assay. Cytotoxic effect of the biogenic Se NPs and selenium dioxide (SeO2) on MCF-7 cell line was assesed by MTT assay. Tranmission electron micrograph (TEM) of the purified Se NPs showed individual and spherical nanostructure in size range of about 80-220nm. The obtained results showed that, at the same concentration of 200μg/mL, Se NPs and SeO2 represented scavenging activity of 23.1±3.4% and 13.2±3.1%, respectively. However, the data obtained from reducing power assay revealed higher electron-donating activity of SeO2 compared to Se NPs. Higher IC50 of the Se NPs (41.5±0.9μg/mL) compared to SeO2 (6.7±0.8μg/mL) confirmed lower cytotoxicity of the biogenic Se NPs on MCF-7 cell line. PMID:24074651

  5. Removal of colloidal biogenic selenium from wastewater.

    PubMed

    Staicu, Lucian C; van Hullebusch, Eric D; Oturan, Mehmet A; Ackerson, Christopher J; Lens, Piet N L

    2015-04-01

    Biogenic selenium, Se(0), has colloidal properties and thus poses solid-liquid separation problems, such as poor settling and membrane fouling. The separation of Se(0) from the bulk liquid was assessed by centrifugation, filtration, and coagulation-flocculation. Se(0) particles produced by an anaerobic granular sludge are normally distributed, ranging from 50 nm to 250 nm, with an average size of 166±29 nm and a polydispersity index of 0.18. Due to its nanosize range and protein coating-associated negative zeta potential (-15 mV to -23 mV) between pH 2 and 12, biogenic Se(0) exhibits colloidal properties, hampering its removal from suspension. Centrifugation at different centrifugal speeds achieved 22±3% (1500 rpm), 73±2% (3000 rpm) and 91±2% (4500 rpm) removal. Separation by filtration through 0.45 μm filters resulted in 87±1% Se(0) removal. Ferric chloride and aluminum sulfate were used as coagulants in coagulation-flocculation experiments. Aluminum sulfate achieved the highest turbidity removal (92±2%) at a dose of 10(-3) M, whereas ferric chloride achieved a maximum turbidity removal efficiency of only 43±4% at 2.7×10(-4) M. Charge repression plays a minor role in particle neutralization. The sediment volume resulting from Al2(SO3)4 treatment is three times larger than that produced by FeCl3. PMID:25559175

  6. High performance amorphous selenium lateral photodetector

    NASA Astrophysics Data System (ADS)

    Abbaszadeh, Shiva; Allec, Nicholas; Karim, Karim S.

    2012-03-01

    Lateral amorphous selenium (a-Se) detectors based on the metal-semiconductor-metal (MSM) device structure have been studied for indirect detector medical imaging applications. These detectors have raised interest due to their simple structure, ease of fabrication, high-speed, low dark current, low capacitance per unit area and better light utilization. The lateral device structure has a benefit that the electrode spacing may be easily controlled to reduce the required bias for a given desired electric field. In indirect conversion x-ray imaging, the scintillator is coupled to the top of the a-Se MSM photodetector, which itself is integrated on top of the thin-film-transistor (TFT) array. The carriers generated at the top surface of the a-Se layer experience a field that is parallel to the surface, and does not initially sweep them away from the surface. Therefore these carriers may recombine or get trapped in surface states and change the field at the surface, which may degrade the performance of the photodetector. In addition, due to the finite width of the electrodes, the fill factor of the device is less than unity. In this study we examine the effect of lateral drift of carriers and the fill factor on the photodetector performance. The impact of field magnitude on the performance is also investigated.

  7. Selenium speciation in flue desulfurization residues.

    PubMed

    Zhong, Liping; Cao, Yan; Li, Wenying; Xie, Kechang; Pan, Wei-Ping

    2011-01-01

    Flue gas from coal combustion contains significant amounts of volatile selenium (Se). The capture of Se in the flue gas desulfurization (FGD) scrubber unit has resulted in a generation of metal-laden residues. It is important to determine Se speciation to understand the environmental impact of its disposal. A simple method has been developed for selective inorganic Se(IV), Se(VI) and organic Se determination in the liquid-phase FGD residues by hydride generation atomic fluorescence spectrometry (AFS). It has been determined that Se(IV), Se(VI) and organic Se can be accurately determined with detection limits (DL) of 0.05, 0.06 and 0.06 microg/L, respectively. The accuracy of the proposed method was evaluated by analyzing the certified reference material, NIST CRM 1632c, and also by analyzing spiked tap-water samples. Analysis indicates that the concentration of Se is high in FGD liquid residues and primarily exists in a reduced state as selenite (Se(IV)). The toxicity of Se(IV) is the strongest of all Se species. Flue gas desulfurization residues pose a serious environmental risk. PMID:21476358

  8. Mercury-selenium interactions in the environment

    SciTech Connect

    Saroff, L.; Lipfert, W.; Moskowitz, P.D.

    1996-02-01

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

  9. Selenium and diabetes - evidence from animal studies

    PubMed Central

    Zhou, Jun; Huang, Kaixun; Lei, Xin Gen

    2013-01-01

    Whereas selenium was found to act as an insulin-mimic and to be anti-diabetic in earlier studies, recent animal experiments and human trials have shown unexpected risk of prolonged high Se intake in potentiating insulin resistance and type 2 diabetes. Elevating dietary Se intakes (0.4 to 3.0 mg/kg of diet) above the nutrient requirements, similar to overproduction of selenoproteins, led to insulin resistance and(or) diabetes-like phenotypes in mice, rats, and pigs. Although its diabetogenic mechanism remains unclear, the high Se intake elevated activity or production of selenoproteins including GPx1, MsrB1, SelS, and SelP. This up-regulation diminished intracellular reactive oxygen species (ROS) and then dys-regulated key regulators of β cells and insulin synthesis and secretion, leading to chronic hyperinsulinaemia. Over-scavenging intracellular H2O2 also attenuated oxidative inhibition of protein tyrosine phosphatases and suppressed insulin signaling. High Se intake might affect expression and(or) function of key regulators for glycolysis, gluconeogenesis, and lipogenesis. Future research is needed to find out if certain forms of Se metabolites in addition to selenoproteins and if mechanisms other than intracellular redox control mediate the diabetogenic effect of high Se intakes. Furthermore, a potential interactive role of high Se intakes in the interphase of carcinogenesis and diabetogenesis should be explored to make the optimal use of Se in human nutrition and health. PMID:23867154

  10. Antioxidant and anticancer properties and mechanisms of inorganic selenium, oxo-sulfur, and oxo-selenium compounds.

    PubMed

    Ramoutar, Ria R; Brumaghim, Julia L

    2010-09-01

    Inorganic selenium and oxo-sulfur compounds are widely available in dietary supplements and have been extensively studied for their antioxidant and anticancer properties. Although many in vivo and clinical trials have been conducted using these compounds, their biochemical and chemical mechanisms of efficacy are the focus of much current research. This review discusses the ability of inorganic selenium compounds, such as selenite, and selenate, to prevent damage from reactive oxygen species as well as their ability to promote cell death by reactive oxygen species generation. Oxo-sulfur and selenium compounds, such as allicin, dimethyl sulfone, methionine sulfoxide, and methylselenenic acid also have similar abilities to act as both antioxidants and pro-oxidants, but the mechanisms for these behaviors are distinctly different from those of the inorganic selenium compounds. The antioxidant and pro-oxidant properties of these small-molecule sulfur and selenium compounds are extremely complex and often greatly depend on experimental conditions, which may explain contradictory literature reports of their efficacy. PMID:20632128

  11. Deposition of selenium coatings on beryllium foils. Revision 1

    SciTech Connect

    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.

  12. Epigenetic regulation of inflammatory gene expression in macrophages by selenium.

    PubMed

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

    2015-02-01

    Acetylation of histone and non-histone proteins by histone acetyltransferases plays a pivotal role in the expression of proinflammatory 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 assays and immunoblotting. Our results indicated that selenium supplementation, as selenite, decreased acetylation of histone H4 at K12 and K16 in COX-2 and TNFα 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 down-regulation 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 Trsp(fl/fl)Cre(LysM) 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 contributes, in part, to their ability to inhibit histone acetylation. In summary, our studies suggest a new role for selenoproteins in the epigenetic modulation of proinflammatory genes. PMID:25458528

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

    SciTech Connect

    Nicholas Ralston; Laura Raymond

    2009-03-30

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

  14. Selenium accumulation in mammals exposed to contaminated California irrigation drainwater

    USGS Publications Warehouse

    Clark, D.R., Jr.

    1987-01-01

    In May 1984, 332 mammals of 10 species were collected at Kesterson Reservoir (San Joaquin Valley, Merced Co., CA), which had received selenium-laden irrigation drainwater, and at the nearby Volta Wildlife Area, which had not. The study concentrated on the California vole (Microtus californicus); 88 were taken at Kesterson, 89 at Volta. Mean selenium concentrations in livers were as much as 522 times higher at Kesterson. There were species-to-species differences at Kesterson; higher selenium concentrations occurred in carnivorous species and/or species that feed on foods closely linked to pond water. There were also pond-to-pond differences at Kesterson; drainwater historically was delivered to Ponds 1 and 2, where concentrations in 1984 were higher, with subsequent flow to other ponds, where they were lower. Whereas none of 50 adult female voles from Kesterson was pregnant, 12 of 41 (29%) from Volta were pregnant. However, this cessation of reproductive activity at Kesterson was probably not due to selenium toxicity but could have resulted because drying conditions at Kesterson forced voles to a seed diet earlier than at Volta. One malformation was found among five embryonic litters of three species from Kesterson. Mammals seem much less susceptible to selenium-induced embryonic abnormalities than birds. No adverse impacts of selenium on wild mammals were demonstrated; however, some sensitive species might have been extirpated from Kesterson before this study began. In addition, high concentrations in small mammal species at Kesterson may threaten predatory birds and mammals that feed on them, with the endangered San Joaquin kit fox (Vulpes macrotis mutica) of particular concern.

  15. Probing for the Activities of Arsenic and Selenium Metabolizing Microbes

    NASA Astrophysics Data System (ADS)

    Stolz, J. F.

    2007-12-01

    Microbial activities can directly impact the mobility and toxicity of arsenic and selenium in the environment. Arsenic is cycled through oxidation/reduction and methylation/demethylation reactions as part of resistance and respiratory processes. The requirement for selenium is primarily for incorporation into selenocysteine and its function in selenoenzymes. Selenium oxyanions can also serve as an electron acceptor in anaerobic respiration. Both culture and culture-independent methods have been developed to detect the presence and activity of organisms capable of arsenic and selenium transformations. Enrichment media have been successful at cultivating arsenate respiring bacteria from a variety of environments, however, both electron donor and the concentration of arsenic can exert strong selective pressure. Thus, the organisms in the enrichment culture may not be the dominant organisms in the environment. Culture-independent methods, including immunological approaches (e.g., polyclonal antibodies to ArrA) and PCR-based technologies, have also had mixed success. PCR-primers designed to amplify portions of genes involved in resistance (e.g., arsC, acr3), respiration (e.g., arrA), and oxidation (e.g., aoxB) have been useful in several environments. Applications include T-RFLP, rt-PCR, and DGGE analyses. Nevertheless, these primers do not work with certain organisms suggesting the existence of additional enzymes and pathways. Although the biosynthetic pathway (and the proteins involved) for selenocysteine has been described in detail, much less is known about selenium methylation, assimilation and respiration. Only one respiratory selenate reductase has been characterized and its close sequence identity with chlorate and perchlorate reductases has complicated efforts to design a functional probe. Thus many aspects of the biogeochemical cycle of selenium remains to be explored.

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

    PubMed Central

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

    2013-01-01

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

  17. Biochemical and Biophysical Characterization of the Selenium-binding and Reducing Site in Arabidopsis thaliana Homologue to Mammals Selenium-binding Protein 1*

    PubMed Central

    Schild, Florie; Kieffer-Jaquinod, Sylvie; Palencia, Andrés; Cobessi, David; Sarret, Géraldine; Zubieta, Chloé; Jourdain, Agnès; Dumas, Renaud; Forge, Vincent; Testemale, Denis; Bourguignon, Jacques; Hugouvieux, Véronique

    2014-01-01

    The function of selenium-binding protein 1 (SBP1), present in almost all organisms, has not yet been established. In mammals, SBP1 is known to bind the essential element selenium but the binding site has not been identified. In addition, the SBP family has numerous potential metal-binding sites that may play a role in detoxification pathways in plants. In Arabidopsis thaliana, AtSBP1 over-expression increases tolerance to two toxic compounds for plants, selenium and cadmium, often found as soil pollutants. For a better understanding of AtSBP1 function in detoxification mechanisms, we investigated the chelating properties of the protein toward different ligands with a focus on selenium using biochemical and biophysical techniques. Thermal shift assays together with inductively coupled plasma mass spectrometry revealed that AtSBP1 binds selenium after incubation with selenite (SeO32−) with a ligand to protein molar ratio of 1:1. Isothermal titration calorimetry confirmed the 1:1 stoichiometry and revealed an unexpectedly large value of binding enthalpy suggesting a covalent bond between selenium and AtSBP1. Titration of reduced Cys residues and comparative mass spectrometry on AtSBP1 and the purified selenium-AtSBP1 complex identified Cys21 and Cys22 as being responsible for the binding of one selenium. These results were validated by site-directed mutagenesis. Selenium K-edge x-ray absorption near edge spectroscopy performed on the selenium-AtSBP1 complex demonstrated that AtSBP1 reduced SeO32− to form a R-S-Se(II)-S-R-type complex. The capacity of AtSBP1 to bind different metals and selenium is discussed with respect to the potential function of AtSBP1 in detoxification mechanisms and selenium metabolism. PMID:25274629

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

    PubMed Central

    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

  19. [Importance of selenium homeostasis in chronic and end-stage kidney diseases].

    PubMed

    Kiss, István

    2013-10-13

    Selenium is an essential trace element for the human body with a significant antioxidant effect. Selenium deficiency and excess are both detrimental for proper functioning of the human body. The possible association between selenium deficiency and acute or chronic renal disease, along with their complications has been less intensively investigated, however, there are firm data showing that selenium deficiency and renal failure increase the risk of both coronary artery disease and total mortality. Further studies revealed that selenium deficiency increases the risk of death due to infection in patients treated with hemodialysis through dysfunction of the immune system. However, there are no data whether the imbalance of selenium metabolism, especially selenium deficiency, could cause chronic kidney disease or renal failure. As far as results of selenium measurements, there is convincing evidence that protein loss and renal replacement treatment reduce serum selenium levels. Despite some contradictory results obtained from various studies regarding selenium deficiency in chronic kidney diseases, it seems that selenium supplementation may be beneficial in many patients with severe or end-stage kidney disease including those treated with dialysis. PMID:24095914

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

    PubMed

    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. PMID:8846151

  1. A turn-on fluorescent nanoprobe for selective determination of selenium(IV).

    PubMed

    Liang, Song; Chen, Jiao; Pierce, David T; Zhao, Julia Xiaojun

    2013-06-12

    A turn-on fluorescent nanoprobe was developed for selective determination of selenium(IV). A trace amount of selenium, as an essential nutrient, plays an important role in human health. It has been proven that a selenium deficiency will result in serious health problems. The developed nanoprobe is capable of in situ detection of selenium with target-induced signaling, and no separation step is needed. The nanoprobe consists of a silica nanoparticle core and a coating layer containing selenium(IV)-induced fluorescent molecules, 3,3'-diaminobenzidine (DAB). The nanoprobes have no fluorescence signals if they are not exposed to selenium(IV). However, the nanoprobes will be "turned on", with fluorescence, when they bind to the targets of selenium(IV). With this strategy, the selenium(IV) are first collected and enriched on a small domain of the nanoprobes. Then, with an excitation at 420 nm, the nanoprobes emit fluorescence signals at 530 nm. The fluorescence intensity is proportional to the selenium concentration. A fluorescence microscope was used to monitor the process of enriching and collecting of the selenium(IV) by the nanoprobes. The optimal conditions for the determination of selenium(IV) using the nanoprobe were investigated including pH, solvent, and linear range. The interference from common metal ions was studied as well. This study is expected to shed light on how to design turn-on fluorescent nanoprobes for in situ monitoring of a wide variety of targets in biological processes. PMID:23676764

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

    PubMed Central

    Zhang, Jinsong; Taylor, Ethan W; Wan, Xiaochun; Peng, Dungeng

    2012-01-01

    Background Elemental selenium nanoparticles have emerged as a novel selenium source with the advantage of reduced risk of selenium toxicity. The present work investigated whether heat treatment affects the size, structure, and bioactivity of selenium nanoparticles. Methods and results After a one-hour incubation of solution containing 80 nm selenium particles in a 90°C water bath, the nanoparticles aggregated into larger 110 nm particles and nanorods (290 nm × 70 nm), leading to significantly reduced bioavailability and phase II enzyme induction in selenium-deficient mice. When a solution containing 40 nm selenium nanoparticles was treated under the same conditions, the nanoparticles aggregated into larger 72 nm particles but did not transform into nanorods, demonstrating that the thermostability of selenium nanoparticles is size-dependent, smaller selenium nanoparticles being more resistant than larger selenium nanoparticles to transformation into nanorods during heat treatment. Conclusion The present results suggest that temperature and duration of the heat process, as well as the original nanoparticle size, should be carefully selected when a solution containing selenium nanoparticles is added to functional foods. PMID:22359458

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

    PubMed

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

    1986-10-01

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

  4. Accelerated aqueous leaching of selenium and arsenic from coal associated rock samples with selenium speciation using ultrasound extraction

    NASA Astrophysics Data System (ADS)

    Pumure, I.; Renton, J. J.; Smart, R. B.

    2009-01-01

    Ultrasound extraction was used to compare the accelerated release rates of selenium and arsenic from three rocks (BT700, BT 571 and BT 60) that are associated with mountaintop mining and valley fill coal mining practiced in southern parts of West Virginia, USA. The concentrations of arsenic released from rocks were found to be three orders of magnitude higher than that of selenium. The accelerated leaching rate constants were ten times higher for arsenic compared to selenium. Se (IV) was found to be stable under ultrasound extraction conditions used whereas As (III) was quickly oxidized to As (V). BT700 was found to have more Se (IV) compared to BT571 while BT60 did not have any significant Se (IV) concentrations. Such compositional and kinetic information becomes important when determining suitable mining waste treatment protocols that have to be undertaken to different types of overburden before it is dumped in valleys.

  5. Is the 90th Percentile Adequate? The Optimal Waist Circumference Cutoff Points for Predicting Cardiovascular Risks in 124,643 15-Year-Old Taiwanese Adolescents

    PubMed Central

    Ho, ChinYu; Chen, Hsin-Jen; Huang, Nicole; Yeh, Jade Chienyu; deFerranti, Sarah

    2016-01-01

    Adolescent obesity has increased to alarming proportions globally. However, few studies have investigated the optimal waist circumference (WC) of Asian adolescents. This study sought to establish the optimal WC cutoff points that identify a cluster of cardiovascular risk factors (CVRFs) among 15-year-old ethnically Chinese adolescents. This study was a regional population-based study on the CVRFs among adolescents who enrolled in all the senior high schools in Taipei City, Taiwan, between 2011 and 2014. Four cross-sectional health examinations of first-year senior high school (grade 10) students were conducted from September to December of each year. A total of 124,643 adolescents aged 15 (boys: 63,654; girls: 60,989) were recruited. Participants who had at least three of five CVRFs were classified as the high-risk group. We used receiver-operating characteristic curves and the area under the curve (AUC) to determine the optimal WC cutoff points and the accuracy of WC in predicting high cardiovascular risk. WC was a good predictor for high cardiovascular risk for both boys (AUC: 0.845, 95% confidence interval [CI]: 0.833–0.857) and girls (AUC: 0.763, 95% CI: 0.731–0.795). The optimal WC cutoff points were ≥78.9 cm for boys (77th percentile) and ≥70.7 cm for girls (77th percentile). Adolescents with normal weight and an abnormal WC were more likely to be in the high cardiovascular risk group (odds ratio: 3.70, 95% CI: 2.65–5.17) compared to their peers with normal weight and normal WC. The optimal WC cutoff point of 15-year-old Taiwanese adolescents for identifying CVRFs should be the 77th percentile; the 90th percentile of the WC might be inadequate. The high WC criteria can help health professionals identify higher proportion of the adolescents with cardiovascular risks and refer them for further evaluations and interventions. Adolescents’ height, weight and WC should be measured as a standard practice in routine health checkups. PMID:27389572

  6. Is the 90th Percentile Adequate? The Optimal Waist Circumference Cutoff Points for Predicting Cardiovascular Risks in 124,643 15-Year-Old Taiwanese Adolescents.

    PubMed

    Lee, Jason Jiunshiou; Ho, ChinYu; Chen, Hsin-Jen; Huang, Nicole; Yeh, Jade Chienyu; deFerranti, Sarah

    2016-01-01

    Adolescent obesity has increased to alarming proportions globally. However, few studies have investigated the optimal waist circumference (WC) of Asian adolescents. This study sought to establish the optimal WC cutoff points that identify a cluster of cardiovascular risk factors (CVRFs) among 15-year-old ethnically Chinese adolescents. This study was a regional population-based study on the CVRFs among adolescents who enrolled in all the senior high schools in Taipei City, Taiwan, between 2011 and 2014. Four cross-sectional health examinations of first-year senior high school (grade 10) students were conducted from September to December of each year. A total of 124,643 adolescents aged 15 (boys: 63,654; girls: 60,989) were recruited. Participants who had at least three of five CVRFs were classified as the high-risk group. We used receiver-operating characteristic curves and the area under the curve (AUC) to determine the optimal WC cutoff points and the accuracy of WC in predicting high cardiovascular risk. WC was a good predictor for high cardiovascular risk for both boys (AUC: 0.845, 95% confidence interval [CI]: 0.833-0.857) and girls (AUC: 0.763, 95% CI: 0.731-0.795). The optimal WC cutoff points were ≥78.9 cm for boys (77th percentile) and ≥70.7 cm for girls (77th percentile). Adolescents with normal weight and an abnormal WC were more likely to be in the high cardiovascular risk group (odds ratio: 3.70, 95% CI: 2.65-5.17) compared to their peers with normal weight and normal WC. The optimal WC cutoff point of 15-year-old Taiwanese adolescents for identifying CVRFs should be the 77th percentile; the 90th percentile of the WC might be inadequate. The high WC criteria can help health professionals identify higher proportion of the adolescents with cardiovascular risks and refer them for further evaluations and interventions. Adolescents' height, weight and WC should be measured as a standard practice in routine health checkups. PMID:27389572

  7. Fractionation of selenium isotopes during bacterial respiratory reduction of selenium oxyanions

    USGS Publications Warehouse

    Herbel, M.J.; Johnson, T.M.; Oremland, R.S.; Bullen, T.D.

    2000-01-01

    Reduction of selenium oxyanions by microorganisms is an important process in the biogeochemical cycling of selenium. Numerous bacteria can reduce Se oxyanions, which are used as electron acceptors during the oxidation of organic matter in anoxic environments. In this study, we used a double spike (82Se and 74Se) thermal ionization mass spectrometry technique to quantify the isotopic fractionation achieved by three different species of anaerobic bacteria capable of accomplishing growth by respiratory reduction of selenate [SeO42- or Se(VI)] or selenite [SeO32- or Se(IV)] to Se(IV) or elemental selenium [Se(0)] coupled with the oxidation of lactate. Isotopic discrimination in these closed system experiments was evaluated by Rayleigh fractionation equations and numerical models. Growing cultures of Bacillus selenitireducens, a haloalkaliphile capable of growth using Se(IV) as an electron acceptor, induced a 80Se/76Se fractionation of -8.0 ?? 0.4??? (instantaneous ?? value) during reduction of Se(IV) to Se(0). With Bacillus arsenicoselenatis, a haloalkaliphile capable of growth using Se(VI) as an electron acceptor, fractionations of -5.0 ?? 0.5??? and -6.0 ?? 1.0??? were observed for reduction of Se(VI) to Se(IV) and reduction of Se(IV) to Se(0), respectively. In growing cultures of Sulfurospirillum barnesii, a freshwater species capable of growth using Se(VI), fractionation was small initially, but near the end of the log growth phase, it increased to -4.0 ?? 1.0??? and -8.4 ?? 0.4??? for reduction of Se(VI) to Se(IV) and reduction of Se(IV) to Se(O), respectively. Washed cell suspensions of S. barnesii induced fractionations of -1.1 ?? 0.4??? during Se(VI) reduction, and -9.1 ?? 0.5% for Se(IV) reduction, with some evidence for smaller values (e.g., -1.7???) in the earliest-formed Se(0) results. These results demonstrate that dissimilatory reduction of selenate or selenite induces significant isotopic fractionation, and suggest that significant Se isotope ratio

  8. Recycling of high purity selenium from CIGS solar cell waste materials

    SciTech Connect

    Gustafsson, Anna M.K. Foreman, Mark R.StJ.; Ekberg, Christian

    2014-10-15

    Highlights: • A new method for recycling of selenium from CIGS solar cell materials is presented. • Separation of selenium as selenium dioxide after heating in oxygen atmosphere. • Complete selenium separation after oxidation of <63 μm particles at 800 °C for 1 h. • After reduction of selenium dioxide the selenium purity was higher than 99.999 wt%. - Abstract: Copper indium gallium diselenide (CIGS) is a promising material in thin film solar cell production. To make CIGS solar cells more competitive, both economically and environmentally, in comparison to other energy sources, methods for recycling are needed. In addition to the generally high price of the material, significant amounts of the metals are lost in the manufacturing process. The feasibility of recycling selenium from CIGS through oxidation at elevated temperatures was therefore examined. During oxidation gaseous selenium dioxide was formed and could be separated from the other elements, which remained in solid state. Upon cooling, the selenium dioxide sublimes and can be collected as crystals. After oxidation for 1 h at 800 °C all of the selenium was separated from the CIGS material. Two different reduction methods for reduction of the selenium dioxide to selenium were tested. In the first reduction method an organic molecule was used as the reducing agent in a Riley reaction. In the second reduction method sulphur dioxide gas was used. Both methods resulted in high purity selenium. This proves that the studied selenium separation method could be the first step in a recycling process aimed at the complete separation and recovery of high purity elements from CIGS.

  9. Sorption and diffusion of selenium oxyanions in granitic rock.

    PubMed

    Ikonen, Jussi; Voutilainen, Mikko; Söderlund, Mervi; Jokelainen, Lalli; Siitari-Kauppi, Marja; Martin, Andrew

    2016-09-01

    The processes controlling diffusion and sorption of radionuclides have been studied extensively in the laboratory, whereas, only a few in-situ experiments have been carried out in order to study in-situ diffusion over the long-term (several years). This is largely due to the fact that in-situ experiments are typically time consuming and cost intensive, and it is commonly accepted that laboratory scale tests are well-established approaches to characterizing the properties of geological media. In order to assess the relevance of laboratory experiments, the Swiss National Cooperative for Disposal of Radioactive Waste (Nagra) have been conducting extensive experiments in the Underground Rock Laboratory (URL) at the Grimsel Test Site (GTS) in order to study radionuclide transport and retention in-situ. One of the elements used in these experiments is non-radioactive selenium, as an analog for the radiotoxic isotope Se-79, which is present in radioactive waste. In this work, two laboratory through-diffusion experiments using selenium as a tracer were carried out in block (decimeter) scale rock specimens to support one of the ongoing radionuclide transport and retention in-situ experiment at the GTS mentioned above. The though-diffusion tests of selenium were performed under atmospheric conditions in both Kuru grey granite (KGG) and Grimsel granodiorite (GG). The decrease of selenium concentration in an inlet hole drilled into each of the rock samples and the breakthrough of selenium into sampling holes drilled around the inlet were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The effective diffusion (De) and distribution coefficients (Kd) of selenium were then determined from the changes of selenium concentration in the inlet and sampling holes using a Time-Domain Diffusion (TDD) simulations. In addition, Kd of selenium was measured by batch sorption experiments as a function of pH and Se concentration in atmospheric conditions and nitrogen

  10. Total selenium and selenium (IV) in the James River estuary and southern Chesapeake Bay

    NASA Astrophysics Data System (ADS)

    Takayanagi, Kazufumi; Wong, George T. F.

    1984-01-01

    The concentrations of total selenium (Se) and Se (IV) were determined in the surface waters of 30 stations located in the James River and southern Chesapeake Bay. The concentrations of total Se and Se (IV) ranged from 0·28 to 1·91 nM and from 0·07 to 1·36 nM, respectively, between salinities of 31·78 and 0·06‰. The concentration of Se (VI), calculated as the difference between the concentrations of total Se and Se (IV), ranged from 0·08 to 0·67 nM. While total Se seemed to be conservative in this study area at salinities above 0·36‰, Se (IV) might have been removed during estuarine mixing. The removal of Se (IV) occurred primarily at salinities below 4‰ possibly via the oxidation of Se (IV) to Se (VI).

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

    PubMed

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

    2015-11-01

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

  12. Novel selenium-doped hydroxyapatite coatings for biomedical applications.

    PubMed

    Rodríguez-Valencia, C; López-Álvarez, M; Cochón-Cores, B; Pereiro, I; Serra, J; González, P

    2013-03-01

    Nowadays there is a short-term need of investigating in orthopedic implants with a greater functionality, including an improved osseointegration and also antibacterial properties. The coating of metallic implants with hydroxyapatite (HA) remains to be the main proposal, but superior quality HA coatings with compositions closer to natural bone apatites, including carbonates, trace elements are required. Selenium is an essential nutrient in biological tissues and, at the same time, it also presents antibacterial properties. A pioneering study on the fabrication of selenium-doped carbonated hydroxyapatite (iHA:Se) coatings by Pulsed Laser Deposition (PLD) is presented. Different proportions of selenium were incorporated to obtain the iHA:Se coatings. Their physicochemical characterization, performed by SEM/EDS, FTIR, FT-Raman, Interferometric Profilometry and XPS, revealed typical columnar growth of HA in globular aggregates and the efficient incorporation of selenium into the HA coatings by the, most probably, substitution of SeO(3)(2-) groups in the CO(3)(2-) sites. Biological evaluation illustrated the absence of cytotoxicity when an amount of 0.6 at.% of Se was added to the iHA:Se coatings and excellent proliferation of the MC3T3-E1 preosteoblasts. Antibacterial properties were also proved with the inhibition of P. aeruginosa and S. aureus from establishing bacterial biofilms. PMID:22968925

  13. Predicting Boron, Molybdenum, Selenium, and Arsenic Adsorption in Soil Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A chemical surface complexation model was applied to boron, molybdenum, selenium, and arsenic adsorption on up to 49 soils selected for variation in soil properties. The surface complexation model was able to fit boron, molybdenum, selenite, and arsenate adsorption on the soils. General regression...

  14. BIOTRANSFER POSSIBILITIES OF SELENIUM FROM PLANTS USED IN PHYTOREMEDIATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytoremediation is the use of plants to remediate soils and water that are contaminated with organic and/or inorganic pollutants, e.g., Se. Selenium at high concentrations is not only potentially harmful to a biological system, but is also an essential trace element for normal nutrition and health...

  15. SELENIUM REMOVAL FROM DRINKING WATER BY ION EXCHANGE

    EPA Science Inventory

    Strong-base anion exchangers were shown to remove selenate and selenite ions from drinking water. Because selenium species are usually present at low concentrations, the efficiency of removal is controlled by the concentration of the common drinking water anions, the most importa...

  16. Selenium and the regulation of cell cycle and apoptosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium was discovered by Berzelius in 1817, and the essentiality of Se was demonstrated that trace amounts of Se protected against liver necrosis in vitamin E deficient rats in the mid-1950s. The benefits of Se are many including protection against cancer, heart diseases, muscle disorders, immunit...

  17. Grain Accumulation of Selenium Species in Rice (Oryza sativa L.)

    EPA Science Inventory

    Selenium (Se) is an essential micronutrient in which up to 1 billion people worldwide are deficient, causing a range of health disorders and potentially an increased risk of certain cancers. Consequently, there is much interest in Se biofortification of rice, the staple food for...

  18. Enhancing nutritiousness of lamb meat and preventing selenium deficiency.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lamb meat is a naturally flavorful and nutritious product. Our research indicates that feeding a specific wheat-milling coproduct will enhance the nutritiousness of lamb, potentially add monetary value to lamb, and prevent Se deficiency. Selenium is an essential micromineral, and Se supplementation ...

  19. Selenium impacts on razorback sucker, Colorado River, Colorado: II. Eggs

    USGS Publications Warehouse

    Hamilton, S.J.; Holley, K.M.; Buhl, K.J.; Bullard, F.A.

    2005-01-01

    Effects on hatching and development of fertilized eggs in adult razorback sucker (Xyrauchen texanus) exposed to selenium in flooded bottomland sites near Grand Junction, Colorado, were determined. After 9 months exposure, fish were collected and induced to spawn and eggs collected for inorganic element analyses. A 9-day egg study was conducted with five spawns from Horsethief ponds, six spawns from Adobe Creek channel, and four spawns from North Pond using a reference water and site waters. Selenium concentrations in eggs were 6.5 ??g/g from Horsethief, 46 ??g/g from Adobe Creek, 38 ??g/g from North Pond, and 6.0 ??g/g from brood stock. Eggs from young adults had a smaller diameter and higher moisture content than brood stock. There were no differences among the four sources in viability, survival, hatch, hatchability, or mortality of deformed embryos or larvae. Adobe Creek larvae had more deformed embryos in eggs held in site water than held in reference water. There were significant negative correlations between selenium concentrations in adult muscle plugs and percent hatch, egg diameter, and deformities in embryos. Results from this study suggest that selenium contamination in parts of the upper basin of the Colorado River should be a major concern to recovery efforts for endangered fish.

  20. Selenium status of a cohort of healthy Americans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies have indicated that few, if any, healthy Americans show signs of selenium (Se) deficiency; however, evidence exists that supplemental Se may reduce cancer risks at some sites in those of lower-Se status. To determine the dose-response relationship of Se intake and Se status in a healthy, no...

  1. Rumen microorganisms decrease bioavailability of inorganic selenium supplements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the availaility of selenium (Se)-enriched trace mineral supplements, we have observed low Se status in cattle and sheep offered traditional inorganic Se supplements. Reasons for this may include inadequate intake or low bioavailability of inorganic Se sources. The objective of this study w...

  2. Selenium impacts on razorback sucker, Colorado River, Colorado II. Eggs.

    PubMed

    Hamilton, Steven J; Holley, Kathy M; Buhl, Kevin J; Bullard, Fern A

    2005-05-01

    Effects on hatching and development of fertilized eggs in adult razorback sucker (Xyrauchen texanus) exposed to selenium in flooded bottomland sites near Grand Junction, Colorado, were determined. After 9 months exposure, fish were collected and induced to spawn and eggs collected for inorganic element analyses. A 9-day egg study was conducted with five spawns from Horsethief ponds, six spawns from Adobe Creek channel, and four spawns from North Pond using a reference water and site waters. Selenium concentrations in eggs were 6.5 microg/g from Horsethief, 46 microg/g from Adobe Creek, 38 microg/g from North Pond, and 6.0 microg/g from brood stock. Eggs from young adults had a smaller diameter and higher moisture content than brood stock. There were no differences among the four sources in viability, survival, hatch, hatchability, or mortality of deformed embryos or larvae. Adobe Creek larvae had more deformed embryos in eggs held in site water than held in reference water. There were significant negative correlations between selenium concentrations in adult muscle plugs and percent hatch, egg diameter, and deformities in embryos. Results from this study suggest that selenium contamination in parts of the upper basin of the Colorado River should be a major concern to recovery efforts for endangered fish. PMID:15814308

  3. Uptake, metabolism, and volatilization of selenium by terrestrial plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The green technology of phytoremediation has being developed for the management of metal(loid)-contaminated soils and waters via the processes of phytoextraction, and phytovolatilization. Based upon these processes a plant management remediation strategy for selenium (Se) has been developed for the ...

  4. Selenium reverses Pteridium aquilinum-induced immunotoxic effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have previously shown that bracken fern (Pteridium aquilinum) has immunomodulatory effects on mouse natural killer (NK) cells by reducing cytotoxicity. Alternatively, it has been demonstrated that selenium can enhance NK cell activity. Therefore, the aims of the present study were to evaluate if ...

  5. Selenium adsorption to aluminum-based water treatment residuals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum-based water treatment residuals (WTR) can adsorb water- and soil-borne P, As(V), As(III), and perchlorate, and may be able to adsorb excess environmental selenium. WTR, clay minerals, and amorphous aluminum hydroxide were shaken for 24 hours in selenate or selenite solutions at pH values o...

  6. Metabolic production of methylated selenium species requires adequate methylation status

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Obesity negatively impacts methylation status and markers of methylation status vary according to selenium status in supplemented subjects. We have proposed that disruptions in methylation capacity induced by obesity compromise demonstrable anti-cancer effects of Se supplementation. In order to addr...

  7. Selenium Accumulation in Flowers and its Effects on Pollination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium, both an essential micronutrient and a potential toxin, is hyperaccumulated by some plants up to 1% of dry weight. The functional significance of this rare phenomenon may be an elemental defense against herbivores and pathogens. In this first of its kind study, we investigate Se distributio...

  8. A role for p53 in selenium-induced senescence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The tumor suppressor p53 and the ataxia-telangiectasia mutated (ATM) kinase play important roles in the senescence response to oncogene activation and DNA damage. We have previously shown that selenium-containing compounds can activate an ATM-dependent senescence response in MRC-5 normal fibroblasts...

  9. Selenium mass balance in the Great Salt Lake, Utah

    USGS Publications Warehouse

    Diaz, X.; Johnson, W.P.; Naftz, D.L.

    2009-01-01

    A mass balance for Se in the south arm of the Great Salt Lake was developed for September 2006 to August 2007 of monitoring for Se loads and removal flows. The combined removal flows (sedimentation and volatilization) totaled to a geometric mean value of 2079??kg Se/yr, with the estimated low value being 1255??kg Se/yr, and an estimated high value of 3143??kg Se/yr at the 68% confidence level. The total (particulates + dissolved) loads (via runoff) were about 1560??kg Se/yr, for which the error is expected to be ?? 15% for the measured loads. Comparison of volatilization to sedimentation flux demonstrates that volatilization rather than sedimentation is likely the major mechanism of selenium removal from the Great Salt Lake. The measured loss flows balance (within the range of uncertainties), and possibly surpass, the measured annual loads. Concentration histories were modeled using a simple mass balance, which indicated that no significant change in Se concentration was expected during the period of study. Surprisingly, the measured total Se concentration increased during the period of the study, indicating that the removal processes operate at their low estimated rates, and/or there are unmeasured selenium loads entering the lake. The selenium concentration trajectories were compared to those of other trace metals to assess the significance of selenium concentration trends. ?? 2008 Elsevier B.V.

  10. Selenium Adsorption To Aluminum-Based Water Treatment Residuals

    EPA Science Inventory

    Aluminum-based water treatment residuals (WTR) can adsorb water-and soil-borne P, As(V), As(III), and perchlorate, and may be able to adsorb excess environmental selenium. WTR, clay minerals, and amorphous aluminum hydroxide were shaken for 24 hours in selenate or selenite solut...

  11. Selenium and mercury interactions wtih emphasis on fish tissue

    EPA Science Inventory

    This review addresses the effects of mercury (Hg) in fish as it relates to the health of the fish themselves as well as potential risks of toxicity in wildlife and humans that consume fish. In particular, it addresses selenium (Se) as a bioindicator of susceptibility to harmful e...

  12. Selenium Characterization In The Global Rice Supply Chain

    EPA Science Inventory

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

  13. BACTERIAL RESPIRATION OF ARSENIC AND SELENIUM. (R826105)

    EPA Science Inventory

    Abstract

    Oxyanions of arsenic and selenium can be used in microbial anaerobic respiration as terminal electron acceptors. The detection of arsenate and selenate respiring bacteria in numerous pristine and contaminated environments and their rapid appearance in enrichme...

  14. Decreased reproductive rates in sheep fed a high selenium diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High Se-containing forages grow on seleniferous soils in many parts of the United States and throughout the world. Selenium is an essential trace element that is required for many physiological processes but can also be either acutely or chronically toxic to livestock. Anecdotal reports of decrease...

  15. Absence of Diabetes Indicators in a Selenium-Supplementation Trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conducted a yr-long intervention with selenium (Se) to characterize dose-response relationships of biomarkers of Se status. Volunteers from Grand Forks, ND, were screened by interview, medical history and clinical biochemistry; individuals with liver or renal dysfunction, uncontrolled hypertensio...

  16. Selenium deficiency, toxicity and biofortification for human health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The melatloid selenium (Se) is ubiquitous in the environment and its concentrations vary from below 0.1 to 10 µg/g or above; although Se concentrations as high as 1200 mg/kg have been reported in some seleniferous regions soil Se concentrations and bioavailability vary with parent material and envir...

  17. Conditional effect of selenium on the mammalian hind gut microbiota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) status is linked to cancer risk in humans and other mammals. Because Se is used by certain microbial species which contain selenoproteins, and because hind gut microfloral composition is linked to cancer development, we proposed that supranutritional Se could reduce tumorigenisis by af...

  18. Selenium bond decreases ON resistance of light-activated switch

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Vitrified amorphous selenium bond decreases the ON resistance of a gallium arsenide-silicon light-activated, low-level switch. The switch is used under a pulse condition to prolong switch life and minimize errors due to heating, devitrification, and overdrawing.

  19. Determination of selenium in the environment and in biological material.

    PubMed Central

    Bem, E M

    1981-01-01

    This paper reviews the following problems, sampling, decomposition procedures and most important analytical methods used for selenium determination, e.g., neutron activation analysis, atomic absorption spectrometry, gas-liquid chromatography, spectrophotometry, fluorimetry, and x-ray fluorescence. This review covers the literature mainly from 1975 to 1977. PMID:7007035

  20. Organo-Selenium-containing Dental Sealant Inhibits Bacterial Biofilm

    PubMed Central

    Tran, P.; Hamood, A.; Mosley, T.; Gray, T.; Jarvis, C.; Webster, D.; Amaechi, B.; Enos, T.; Reid, T.

    2013-01-01

    Oral bacteria, including Streptococcus mutans and Streptococcus salivarius, contribute to tooth decay and plaque formation; therefore, it is essential to develop strategies to prevent dental caries and plaque formation. We recently showed that organo-selenium compounds covalently attached to different biomaterials inhibited bacterial biofilms. Our current study investigates the efficacy of an organo-selenium dental sealant (SeLECT-DefenseTM sealant) in inhibiting S. mutans and S. salivarius biofilm formation in vitro. The organo-selenium was synthesized and covalently attached to dental sealant material via standard polymer chemistry. By colony-forming unit (CFU) assay and confocal microscopy, SeLECT-DefenseTM sealant was found to completely inhibit the development of S. mutans and S. salivarius biofilms. To assess the durability of the anti-biofilm effect, we soaked the SeLECT-DefenseTM sealant in PBS for 2 mos at 37°C and found that the biofilm-inhibitory effect was not diminished after soaking. To determine if organo-selenium inhibits bacterial growth under the sealant, we placed SeLECT-Defense sealant over a lawn of S. mutans. In contrast to a control sealant, SeLECT-DefenseTM sealant completely inhibited the growth of S. mutans. These results suggest that the inhibitory effect of SeLECT-DefenseTM sealant against S. mutans and S. salivarius biofilms is very effective and durable. PMID:23475900

  1. SPECIATION OF SELENIUM AND ARSENIC COMPOUNDS BY CAPILLARY...

    EPA Science Inventory

    Capillary electrophoresis (CE) with hydride generation inductively coupled plasma mass spectrometry was used to determine four arsenicals and two selenium species. Selenate (SeVI) was reduced on-line to selenite (SeIV) by mixing the CE effluent with concentrated HCl. A microporou...

  2. Global advances in selenium research from theory to application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium is without question one of the most influential natural-occurring trace elements for biological systems worldwide. The multi-faceted connections between the environment, food crops, human and animal health and selenium’s function through selenoprotein activity, have been well characterized....

  3. Interspecific and intraspecific variation in selenium:mercury molar ratios in saltwater fish from the Aleutians: Potential protection on mercury toxicity by selenium

    PubMed Central

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

    2014-01-01

    A number of factors affect the consumption risk from mercury in fish, including mercury levels, seasonal patterns of mercury concentrations, human consumption patterns, and sensitive populations (e.g. pregnant women, fetuses, young children, and yet unknown genetic factors). Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for saltwater fish. We examine levels of mercury and selenium in several species of fish and seabirds from the Aleutians (Alaska), determine selenium:mercury molar ratios, and examine species-specific and individual variation in the ratios as a means of exploring the use of the ratio in risk assessment and risk management. Variation among species was similar for mercury and selenium. There was significant inter-specific and intraspecific variation in selenium:mercury molar ratios for fish, and for birds. The mean selenium:mercury molar ratios for all fish and bird species were above 1, meaning there was an excess of selenium relative to mercury. It has been suggested that an excess of selenium confers some protective advantage for salt water fish, although the degree of excess necessary is unclear. The selenium:mercury molar ratio was significantly correlated negatively with total length for most fish species, but not for dolly varden. Some individuals of Pacific cod, yellow irish lord, rock greenling, Pacific halibut, dolly varden, and to a lesser extent, flathead sole, had selenium:mercury ratios below 1. No bird muscle had an excess of mercury (ratio below 1), and only glaucous-winged gull and pigeon guillemot had ratios between 1 and 5. There was a great deal of variation in selenium:mercury molar ratios within fish species, and within bird species, making it difficult and impractical to use these ratios in risk assessment or management, for fish advisories, or for consumers, particularly given the difficulty of interpreting the ratios. PMID:22664537

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

    SciTech Connect

    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

  5. Geologic and Anthropogenic Controls on Selenium and Nitrate Loading to Southern California Streams

    NASA Astrophysics Data System (ADS)

    Hibbs, B. J.; Ellis, A. S.

    2009-12-01

    We have identified three urban watersheds with elevated selenium concentrations in the Los Angeles Basin. These include San Diego Creek Watershed of Orange County, Malibu Creek Watershed of Los Angeles County, and tributaries to the Los Angeles River. All of these provide ecological habitat to migratory waterfowl. Dry weather surface flows in these watersheds contain 20 to 35 ug/L dissolved selenium. Shallow groundwater in these watersheds contains 30 to 300 ug/L dissolved selenium. Concentrations exceed the USEPA chronic criterion for selenium of 5 ug/L for protection of aquatic life. Miocene marine shales and siltstones in the Monterrey-Modelo-Puente formation appear to be the original sources of selenium in these watersheds. Selenium is leached into groundwater from these low-permeability strata, along with standard inorganic constituents (primarily sulfate) and phosphorous. Elevated selenium concentrations develop in shallow groundwater, and baseflows carry selenium into urban surface streams. Groundwater baseflows account for most of the selenium loading to streams. Positive correlations are observed between nitrate and selenium in both groundwater and surface water in the watersheds we investigated. Previous theoretical calculations showed favorable Gibbs free energies for oxidation of selenium by dissolved nitrate. Empirical batch studies support theoretical calculations for mobilization of selenium by nitrate in marine shales. Positive correlation between nitrate and selenium in our studies appears to be related to nitrate sourced from atmospheric fallout, agriculture, and treated wastewater application. Laboratory leaching experiments carried out on weathered and unweathered Monterrey rocks from the Malibu Creek Watershed showed high selenium concentrations only when nitrate was leached from the rocks in high concentrations. Selenium concentrations were non-detectable or very dilute when nitrate was not leached from rocks. Weathered rock generally had high

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

    PubMed

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

    2016-05-01

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

  7. Uptake, distribution, and turnover rates of selenium in barley.

    PubMed

    Huang, K X; Clausen, J

    1994-03-01

    The present communication elucidates initially the topographic distribution of selenium in barley grains. Then by the fluorimetric method the uptake of selenium (selenite) in 8-16 d old germinating barley was estimated. Finally by means of 75Se the anabolic and catabolic rates (turnover) of 75Se (selenite) was compared. The distribution of selenium in barley was evaluated after micro-dissection of barley grains. In dried grains the highest concentration was found in husk and pericarp with about 0.6 ppm Se. Then followed Scutellum with 0.4 and 0.3 ppm in embryon. The aleurone layer, embryonic leaves, and initial root did only have 0.2 ppm Se. In order to know more about the uptake and distribution of selenium in 8-d-old barley, the plants were cultivated for a further 8 d in the culture medium with variation in selenite concentration. In roots and leaves, the uptake did not arrive at saturation during the period studied since the dose-response curve increased up to 0.34 mM selenite in the medium, whereas the selenium levels were about 200 ppm in roots and 30 ppm in leaves. However, the uptake was linear, with concentration during 8 d of cultivation up to 0.84 microM selenite for grain and stem. At higher concentrations the dose-response curve diminished its slope. At 0.34 mM selenite the concentration in grain increased to 6.87 ppm and in the stem to 8.13 ppm. The uptake, distribution, and catabolic rate of selenium components in germinating barley were further evaluated by exposing the plants to 0.0492 microCi 75Se (12.6 microM selenite) for up to 4 d. Then the plants were moved to a selenium deficient medium for further 4 d. Then finally the medium was supplemented with high doses of cold selenite (0.126 mM selenite) for further 4 d. The first third period made it possible to estimate the rate of uptake. It was highest in roots (313 fmol/h/mg dw), i.e., about 10 times those of grains, stems, and leaves. The intermediate period where the barley was transferred to a

  8. Phytoremediation of selenium-contaminated soils and waters: fundamentals and future prospects.

    PubMed

    Bañuelos, G S; Lin, Z Q; Wu, L; Terry, N

    2002-01-01

    Interest in selenium pollution and remediation technology has escalated during the past two decades. Although not known to be essential for plants, selenium is an essential micronutrient for humans and animals, having important benefits for their nutrition. At high concentrations, however, selenium becomes toxic to animals and humans. A major selenium controversy in the 1980s emerged in California at the Kesterson National Wildlife Refuge; hence, scientists, environmental regulators, politicians, and the general public in the United States became aware of selenium's potential as an environmental contaminant. Consequently, extensive research has been conducted in the western United States, and a vast amount of financial resources have been allocated to develop management strategies and remediation technologies for reducing the impact of naturally occurring selenium on the biological environment. A plant-based technology, defined as 'phytoremediation', has received increasing recognition as a low-cost, environmentally friendly approach for managing the toxic effects of selenium. Plants have the ability to absorb and sequester selenium and to convert inorganic selenium to volatile forms of organic compounds that are released harmlessly into the atmosphere. The present review summarizes recent research findings and information about strategies on using phytoremediation systems to detoxify selenium-contaminated soils and waters in natural and agricultural ecosystems. PMID:12611471

  9. Mitochondrial Protein Profile in Mice with Low or Excessive Selenium Diets.

    PubMed

    Hu, Lianmei; Wang, Congcong; Zhang, Qin; Yan, Hao; Li, Ying; Pan, Jiaqiang; Tang, Zhaoxin

    2016-01-01

    Dietary selenium putatively prevents oxidative damage, whereas excessive selenium may lead to animal disorder. In this study, we investigated the effects of low and excessive levels of dietary selenium on oxidative stress and mitochondrial proteins in mouse liver. Six to eight week old mice were fed a diet with low, excessive, or moderate (control) levels of selenium (sodium selenite). The selenium concentration and oxidative stress-related parameters in hepatic mitochondria were evaluated. Two-dimensional electrophoresis and mass spectrometry were applied to identify the differentially-expressed proteins associated with dietary selenium. The selenium content of the livers in mice with the low selenium diet was significantly lower than that of the control, while that of mice fed excessive levels was significantly higher. In both groups oxidative stress in hepatic mitochondria was found; accompanied by lower superoxide dismutase (SOD) and glutathione peroxidase (GPX) levels and higher malondialdehyde (MDA) content, compared with the control group. Furthermore, ten proteins in the hepatic mitochondria of the selenium-low or -excessive groups with more than two-fold differences in abundance compared with the control group were identified. The differentially-expressed proteins in hepatic mitochondria may be associated with dietary (low or excessive) selenium-induced oxidative stress. PMID:27428959

  10. Mitochondrial Protein Profile in Mice with Low or Excessive Selenium Diets

    PubMed Central

    Hu, Lianmei; Wang, Congcong; Zhang, Qin; Yan, Hao; Li, Ying; Pan, Jiaqiang; Tang, Zhaoxin

    2016-01-01

    Dietary selenium putatively prevents oxidative damage, whereas excessive selenium may lead to animal disorder. In this study, we investigated the effects of low and excessive levels of dietary selenium on oxidative stress and mitochondrial proteins in mouse liver. Six to eight week old mice were fed a diet with low, excessive, or moderate (control) levels of selenium (sodium selenite). The selenium concentration and oxidative stress-related parameters in hepatic mitochondria were evaluated. Two-dimensional electrophoresis and mass spectrometry were applied to identify the differentially-expressed proteins associated with dietary selenium. The selenium content of the livers in mice with the low selenium diet was significantly lower than that of the control, while that of mice fed excessive levels was significantly higher. In both groups oxidative stress in hepatic mitochondria was found; accompanied by lower superoxide dismutase (SOD) and glutathione peroxidase (GPX) levels and higher malondialdehyde (MDA) content, compared with the control group. Furthermore, ten proteins in the hepatic mitochondria of the selenium-low or -excessive groups with more than two-fold differences in abundance compared with the control group were identified. The differentially-expressed proteins in hepatic mitochondria may be associated with dietary (low or excessive) selenium-induced oxidative stress. PMID:27428959

  11. Selenium Accumulating Leafy Vegetables Are a Potential Source of Functional Foods

    PubMed Central

    Mabeyo, Petro E.; Manoko, Mkabwa L. K.; Gruhonjic, Amra; Fitzpatrick, Paul A.; Landberg, Göran; Erdélyi, Máté; Nyandoro, Stephen S.

    2015-01-01

    Selenium deficiency in humans has been associated with various diseases, the risks of which can be reduced through dietary supplementation. Selenium accumulating plants may provide a beneficial nutrient for avoiding such illnesses. Thus, leafy vegetables such as Amaranthus hybridus, Amaranthus sp., Cucurbita maxima, Ipomoea batatas, Solanum villosum, Solanum scabrum, and Vigna unguiculata were explored for their capabilities to accumulate selenium when grown on selenium enriched soil and for use as a potential source of selenium enriched functional foods. Their selenium contents were determined by spectrophotometry using the complex of 3,3′-diaminobenzidine hydrochloride (DABH) as a chromogen. The mean concentrations in the leaves were found to range from 7.90 ± 0.40 to 1.95 ± 0.12 μg/g dry weight (DW), with C. maxima accumulating the most selenium. In stems, the accumulated selenium content ranged from 1.12 ± 0.10 μg/g in Amaranthus sp. to 5.35 ± 0.78 μg/g DW in C. maxima and was hence significantly different (P < 0.01). The cancer cell line MDA-MB-231 was used in cytotoxicity assays to determine the anticancer potential of these extracts. With exception of S. scabrum and S. villosum, no cytotoxicity was detected for the selenium enriched vegetable extracts up to 100 μg/mL concentration. Hence, following careful evaluation the studied vegetables may be considered as selenium enriched functional foods. PMID:26955635

  12. Selenium Accumulating Leafy Vegetables Are a Potential Source of Functional Foods.

    PubMed

    Mabeyo, Petro E; Manoko, Mkabwa L K; Gruhonjic, Amra; Fitzpatrick, Paul A; Landberg, Göran; Erdélyi, Máté; Nyandoro, Stephen S

    2015-01-01

    Selenium deficiency in humans has been associated with various diseases, the risks of which can be reduced through dietary supplementation. Selenium accumulating plants may provide a beneficial nutrient for avoiding such illnesses. Thus, leafy vegetables such as Amaranthus hybridus, Amaranthus sp., Cucurbita maxima, Ipomoea batatas, Solanum villosum, Solanum scabrum, and Vigna unguiculata were explored for their capabilities to accumulate selenium when grown on selenium enriched soil and for use as a potential source of selenium enriched functional foods. Their selenium contents were determined by spectrophotometry using the complex of 3,3'-diaminobenzidine hydrochloride (DABH) as a chromogen. The mean concentrations in the leaves were found to range from 7.90 ± 0.40 to 1.95 ± 0.12 μg/g dry weight (DW), with C. maxima accumulating the most selenium. In stems, the accumulated selenium content ranged from 1.12 ± 0.10 μg/g in Amaranthus sp. to 5.35 ± 0.78 μg/g DW in C. maxima and was hence significantly different (P < 0.01). The cancer cell line MDA-MB-231 was used in cytotoxicity assays to determine the anticancer potential of these extracts. With exception of S. scabrum and S. villosum, no cytotoxicity was detected for the selenium enriched vegetable extracts up to 100 μg/mL concentration. Hence, following careful evaluation the studied vegetables may be considered as selenium enriched functional foods. PMID:26955635

  13. Effect of selenium on the lipids of two unicellular marine algae

    SciTech Connect

    Gennity, J.M.

    1983-01-01

    The incorporation of selenium into the lipids of two unicellar marine algae has been investigated. Axenic cultures of the green algae Dunaliella primolecta and the red algae Porphyridium cruentum were grown in the presence of sublethal quantities of selenium (10 ppm) as selenite. Both algae were found to contain selenium bound to all purified lipids, except for saturated hydrocarbons. Of the lipids which contain selenium, carotenoid pigments show the greatest selenium concentration (..beta..-carotene: 1.3..mu..gSe/mg lipid; zeaxanthin: 1.1..mu..gSe/mg lipid) in both algae. P. cruentum contains about ten times as much lipid-associated selenium as D. primolecta, even though the lipids of both algae were very similar. This selenium has been shown to be incorporated non-metabolically into the lipid molecule. The lipid-associated selenium is probably non-covalently bound to the lipid molecule and may interact with double bonds. Selenite does not affect the lipid composition of D. primolecta, as compared with algae grown in the absence of added selenium. A selenium-induced 40% decrease in the cell content of eicosapentaenoic acid (20:5omega3) and 20% decrease in arachidonic acid (20:4omega6) in polar lipids (glycolipids plus phospholipids) was observed in P. cruentum. A 25% decrease in the chlorophyll a content of this red algae also occurred. The cell content of other fatty acids, phospholipids and glycolipids was unaltered by selenium. These results are consistent with a selenite-induced oxidation of P. cruentum lipids. Selenium is able to increase the antioxidant potential of algal cells. However, no in vivo selenium-induced protection of algal lipids from oxidation was apparent.

  14. Plasma selenium levels and oxidative stress biomarkers: a gene-environment interaction population-based study.

    PubMed

    Galan-Chilet, Inmaculada; Tellez-Plaza, Maria; Guallar, Eliseo; De Marco, Griselda; Lopez-Izquierdo, Raul; Gonzalez-Manzano, Isabel; Carmen Tormos, M; Martin-Nuñez, Gracia M; Rojo-Martinez, Gemma; Saez, Guillermo T; Martín-Escudero, Juan C; Redon, Josep; Javier Chaves, F

    2014-09-01

    The role of selenium exposure in preventing chronic disease is controversial, especially in selenium-repleted populations. At high concentrations, selenium exposure may increase oxidative stress. Studies evaluating the interaction of genetic variation in genes involved in oxidative stress pathways and selenium are scarce. We evaluated the cross-sectional association of plasma selenium concentrations with oxidative stress levels, measured as oxidized to reduced glutathione ratio (GSSG/GSH), malondialdehyde (MDA), and 8-oxo-7,8-dihydroguanine (8-oxo-dG) in urine, and the interacting role of genetic variation in oxidative stress candidate genes, in a representative sample of 1445 men and women aged 18-85 years from Spain. The geometric mean of plasma selenium levels in the study sample was 84.76 µg/L. In fully adjusted models the geometric mean ratios for oxidative stress biomarker levels comparing the highest to the lowest quintiles of plasma selenium levels were 0.61 (0.50-0.76) for GSSG/GSH, 0.89 (0.79-1.00) for MDA, and 1.06 (0.96-1.18) for 8-oxo-dG. We observed nonlinear dose-responses of selenium exposure and oxidative stress biomarkers, with plasma selenium concentrations above ~110 μg/L being positively associated with 8-oxo-dG, but inversely associated with GSSG/GSH and MDA. In addition, we identified potential risk genotypes associated with increased levels of oxidative stress markers with high selenium levels. Our findings support that high selenium levels increase oxidative stress in some biological processes. More studies are needed to disentangle the complexity of selenium biology and the relevance of potential gene-selenium interactions in relation to health outcomes in human populations. PMID:25017966

  15. Assessment of selenium pollution in agricultural soils in the Xuzhou District, Northwest Jiangsu, China.

    PubMed

    Huang, Shunsheng; Hua, Ming; Feng, Jinshun; Zhong, Xinyong; Jin, Yang; Zhu, Baiwan; Lu, Hua

    2009-01-01

    Xuzhou City is an important base for coal production and coal-fired power. To evaluate selenium contamination in this area, we sampled agricultural soil, soil profile, irrigation water, bedrock, coal, fly ash, paddy rice, and vegetables from the north of Xuzhou City, and determined their selenium contents. The background level of selenium in the soil profile was 0.08 mg/kg. The selenium concentrations in agricultural soils and irrigation water were in the range of 0.21-4.08 mg/kg and 0.002-0.29 mg/L, respectively. Soils with high selenium content were located closely to coalmines and power plants. The average selenium concentrations in coal and coal fly ash were 5.46 and 2.81 mg/kg, respectively. In contrast, the concentrations of selenium in bedrock and in the soil profile were very low. These results imply that the high selenium level in agricultural soils is mainly caused by anthropogenic activities, rather than by parent material. The arithmetic mean of selenium concentration in paddy rice was 0.116 mg/kg, and in cabbage was 0.05 mg/kg. The selenium concentration in rice was positively correlated with total selenium concentration in soil, suggesting that selenium in soil is readily transferred into the crops. Furthermore, the estimated dietary intake (88.8 microg) of selenium from paddy rice and cabbage exceeds the recommended dietary allowance (55 microg). Therefore, there is a potential health risk from consumption of local staple food in the study area. PMID:19634423

  16. Selenium impacts on razorback sucker, Colorado River, Colorado: I. Adults

    USGS Publications Warehouse

    Hamilton, S.J.; Holley, K.M.; Buhl, K.J.; Bullard, F.A.; Weston, L.K.; McDonald, S.F.

    2005-01-01

    Adult razorback sucker (Xyrauchen texanus) were exposed to various selenium concentrations in ponds and isolated river channels of the Colorado River near Grand Junction, CO, to determine effects on their growth and residue accumulation over an 11-month period. Adults at Horsethief ponds were fed a commercial diet, whereas fish at Adobe Creek channel and North Pond foraged on natural food items. Selenium concentrations at Horsethief were 2.2 ??g/L in water, 0.1-1.4 ??g/g in sediment, and 2.3-3.1 ??g/g in food organisms (1.1 ??g/g in commercial fish food), at Adobe Creek were 3.8 ??g/L in water, 0.5-2.1 ??g/g in sediment, and 4-56 ??g/g in food organisms, and at North Pond were 9.5 ??g/L in water, 7-55 ??g/g in sediment, and 20-81 ??g/g in food organisms. The selenium concentrations in muscle plugs from adults at Adobe Creek (11.7 ??g/g, SD=0.4, n=6) and North Pond (16.6 ??g/g, SD=1.0, n=6) were greater than at Horsethief (4.5 ??g/g, SD=0.2, n=6). During a depuration period adults from Adobe Creek and North Pond lost 1-2% of their selenium burden in 32 days and 14-19% in 66 days. Selenium accumulated in razorback sucker above toxic thresholds reported in other studies, yet those residues were less than those reported in muscle plugs of 40% of wild razorback sucker caught in the Green River, Utah.

  17. Selenium impacts on razorback sucker, Colorado River, Colorado I. Adults.

    PubMed

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

    2005-05-01

    Adult razorback sucker (Xyrauchen texanus) were exposed to various selenium concentrations in ponds and isolated river channels of the Colorado River near Grand Junction, CO, to determine effects on their growth and residue accumulation over an 11-month period. Adults at Horsethief ponds were fed a commercial diet, whereas fish at Adobe Creek channel and North Pond foraged on natural food items. Selenium concentrations at Horsethief were 2.2 microg/L in water, 0.1-1.4 microg/g in sediment, and 2.3-3.1 microg/g in food organisms (1.1 microg/g in commercial fish food), at Adobe Creek were 3.8 microg/L in water, 0.5-2.1 microg/g in sediment, and 4-56 microg/g in food organisms, and at North Pond were 9.5 microg/L in water, 7-55 microg/g in sediment, and 20-81 microg/g in food organisms. The selenium concentrations in muscle plugs from adults at Adobe Creek (11.7 microg/g, SD = 0.4, n = 6) and North Pond (16.6 microg/g, SD = 1.0, n = 6) were greater than at Horsethief (4.5 microg/g, SD = 0.2, n = 6). During a depuration period adults from Adobe Creek and North Pond lost 1-2% of their selenium burden in 32 days and 14-19% in 66 days. Selenium accumulated in razorback sucker above toxic thresholds reported in other studies, yet those residues were less than those reported in muscle plugs of 40% of wild razorback sucker caught in the Green River, Utah. PMID:15814307

  18. Diagnostic criteria for selenium toxicosis in aquatic birds: histologic lesions

    USGS Publications Warehouse

    Green, D.E.; Albers, P.H.

    1997-01-01

    Chronic selenium toxicosis was induced in 1-year-old male mallard ducks (Anas platyrhynchos) by feeding selenium, as seleno-DL-methionine, in amounts of 0, 10, 20, 40, and 80 parts per million (ppm) to five groups of 21 ducks each for 16 wk during March to July 1988. All mallards in the 80 ppm group, three in the 40 ppm group, and one in the 20 ppm group died. Histologic lesions in mallards that died of selenosis were hepatocellular vacuolar degeneration progressing to centrolobular and panlobular necrosis, nephrosis, apoptosis of pancreatic exocrine cells, hypermaturity and avascularity of contour feathers of the head with atrophy of feather follicles, lymphocytic necrosis and atrophy of lymphoid organs (spleen, gut-associated lymphoid tissue, and lumbar lymph nodes), and severe atrophy and degeneration of fat. Histologic lesions in surviving mallards in the 40 ppm group, which had tissue residues of selenium comparable to mallards that died, were fewer and much milder than mallards that died; lesions consisted of atrophy of lymphoid tissue, hyalinogranular swelling of hepatocytes, atrophy of seminiferous tubules, and senescence of feathers. No significant histologic lesions were detected in euthanized mallards in the 0, 10 and 20 ppm groups. Based on tissue residues and histologic findings, primarily in the liver, there was a threshold of selenium accumulation above which pathophysiologic changes were rapid and fatal. Pathognomonic histologic lesions of fatal and nonfatal selenosis were not detected. Criteria for diagnosis of fatal selenosis in aquatic birds include consistent histologic lesions in the liver, kidneys, and organs of the immune system. Although histologic changes were present in cases of chronic non-fatal selenosis, these were inconsistent. Consistent features of fatal and non-fatal chronic selenosis were marked weight loss and elevated concentrations of selenium in organs.

  19. Selenium. Role of the Essential Metalloid in Health

    PubMed Central

    Kurokawa, Suguru; Berry, Marla J.

    2015-01-01

    Selenium is an essential micronutrient in mammals, but is also recognized as toxic in excess. It is a non-metal with properties that are intermediate between the chalcogen elements sulfur and tellurium. Selenium exerts its biological functions through selenoproteins. Selenoproteins contain selenium in the form of the 21st amino acid, selenocysteine (Sec), which is an analog of cysteine with the sulfur-containing side chain replaced by a Se-containing side chain. Sec is encoded by the codon UGA, which is one of three termination codons for mRNA translation in non-selenoprotein genes. Recognition of the UGA codon as a Sec insertion site instead of stop requires a Sec insertion sequence (SECIS) element in selenoprotein mRNAs and a unique selenocysteyl-tRNA, both of which are recognized by specialized protein factors. Unlike the 20 standard amino acids, Sec is biosynthesized from serine on its tRNA. Twenty-five selenoproteins are encoded in the human genome. Most of the selenoprotein genes were discovered by bioinformatics approaches, searching for SECIS elements downstream of in-frame UGA codons. Sec has been described as having stronger nucleophilic and electrophilic properties than cysteine, and Sec is present in the catalytic site of all selenoenzymes. Most selenoproteins, whose functions are known, are involved in redox systems and signaling pathways. However, several selenoproteins are not well characterized in terms of their function. The selenium field has grown dramatically in the last few decades, and research on selenium biology is providing extensive new information regarding its importance for human health. PMID:24470102

  20. RESPONSE OF SELENIUM STATUS INDICATORS TO SUPPLEMENTATION OF HEALTHY NORTH AMERICAN MEN WITH HIGH-SELENIUM YEAST

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a prior study, we observed decreased serum 3,3’,5-triiodothyronine (t3), increased serum thyrotropin and increased body weight in 5 men fed 297 'g/d of selenium (Se) in foods naturally high in Se while confined in a metabolic research unit. In an attempt to replicate and confirm those observation...

  1. SPECIATION OF SELENIUM(IV) AND SELENIUM(VI) USING COUPLED ION CHROMATOGRAPHY: HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROMETRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simple method was developed to speciate inorganic selenium in the microgram per liter range using coupled ion chromatography-hydride generation atomic absorption spectrometry. Because of the differences in toxicity and adsorption behavior, determination of the redox states selenite, Se(IV), and s...

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

    PubMed Central

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

    2015-01-01

    Selenium status of the Danish population is below that assumed optimal for the suggested protective effects against chronic diseases, including certain cancers. Fish and shellfish are important dietary sources of selenium in Denmark. We investigated the effect of increased fish and mussel intake on selenium blood concentrations in a population with relatively low habitual dietary selenium intake. We randomly assigned 102 healthy men and women (all non-smokers) aged 48–76 years to an intervention group (n = 51) or a control group (n = 51). Intervention participants received 1000 g fish and mussels/week for 26 weeks (~50 μg selenium/day). Controls received no intervention. Non-fasting blood samples were taken and whole blood selenium was determined using inductively coupled plasma-mass spectrometry (ICP-MS), and plasma selenoprotein P (SelP) was determined by high performance liquid chromatography coupled to ICP-MS. All available observations were included in linear multiple regression analysis to evaluate the effect of the intervention. The difference in mean change for intervention compared with control persons was 14.9 ng/mL (95% CI: 10.2, 19.7) for whole blood selenium, and 7.0 ng/mL (95% CI: 3.1, 10.9) for plasma SelP (Weeks 0–26). Selenium concentrations were significantly increased after 26 weeks of intervention, albeit to a lower degree than expected. PMID:25599275

  3. Effects of Dietary Selenium and Vitamin E on Growth Performance, Meat Yield, and Selenium Content and Lipid Oxidation of Breast Meat of Broilers Reared Under Heat Stress.

    PubMed

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

    2016-01-01

    This study was conducted using 360 broiler chickens to evaluate the effects of dietary vitamin E (0, 125, and 250 mg/kg), selenium (0, 0.5, and 1 mg/kg), or their different combinations on performance, meat yield, and selenium content and lipid oxidation of breast meat of broilers raised under either a thermoneutral (TN, 24 °C constant) or heat stress (HS, 24 to 37 °C cycling) condition. There was a reduction (P < 0.05) in body weight and feed intake and an increase (P < 0.05) in feed conversion ratio when broilers exposed to HS. In the overall period of the study (1 to 49 days), growth performance of TN broilers was not affected (P < 0.05) by vitamin E and selenium supplementation. However, under HS condition, broilers receiving 250 mg/kg vitamin E and 0.5 mg/kg selenium consumed more (P < 0.05) feed than that of broilers receiving 250 mg/kg vitamin E alone, but similar (P > 0.05) to that of broilers receiving 250 mg/kg vitamin E and 1 mg/kg selenium. The malondialdehyde (MDA) content of the breast meat was increased (P < 0.05), but its selenium content was decreased (P < 0.05) by exposure to HS. The breast meat selenium content was increased (P < 0.05) by selenium supplementation. The breast meat selenium content was decreased (P < 0.05) by supplementation of 250 mg/kg vitamin E to diet of TN birds. However, the breast meat selenium content was increased (P < 0.05) by supplementation of vitamin E under HS condition. The breast meat MDA content was not affected (P > 0.05) by dietary treatments under TN condition. However, the breast meat MDA content was decreased (P < 0.05) by both vitamin E and selenium supplementation under HS condition, and the lowest MDA content was observed in the breast meat of broilers receiving combination of 125 mg/kg vitamin E and 1 mg/kg selenium. The results showed that supplementation of selenium and vitamin E was capable of increasing the selenium content of the breast meat and could improve the lipid

  4. An original discovery: selenium deficiency and Keshan disease (an endemic heart disease).

    PubMed

    Chen, Junshi

    2012-01-01

    This is a review article telling a 50-years old story about the studies on selenium deficiency and Keshan disease in China, an endemic heart disease with high case-fatality, as an example of translational research. Extensive cross-sectional epidemiological studies showed that low selenium concentrations in cereal grains and low selenium status of local residents were associated with the occurrence of Keshan disease. Several large population based intervention trials using oral administration of sodium selenite tablets showed significant reduction of Keshan disease incidence. Based on the above evidence, it was concluded that selenium deficiency is the major cause of Keshan disease, although other etiological factors could not be ruled out. The implications of the findings include: provided critical scientific evidence for selenium being an essential trace element for humans; as scientific basis for identifying minimum requirement and RDA/RNI for selenium; and as solid reference for the formulation of effective preventive measures for Keshan disease in China. PMID:22705420

  5. Biosynthesis of selenium nanoparticles using Klebsiella pneumoniae and their recovery by a simple sterilization process

    PubMed Central

    Fesharaki, Parisa Jafari; Nazari, Pardis; Shakibaie, Mojtaba; Rezaie, Sassan; Banoee, Maryam; Abdollahi, Mohammad; Shahverdi, Ahmad Reza

    2010-01-01

    The use of biologically derived metal nanoparticles for various proposes is going to be an issue of considerable importance; thus, appropriate methods should be developed and tested for the biological synthesis and recovery of these nanoparticles from bacterial cells. In this research study, a strain of Klebsiella pneumoniae was tested for its ability to synthesize elemental selenium nanoparticles from selenium chloride. A broth of Klebsiella pneumoniae culture containing selenium nanoparticles was subjected to sterilization at 121oC and 17 psi for 20 minutes. Released selenium nanoparticles ranged in size from 100 to 550 nm, with an average size of 245 nm. Our study also showed that no chemical changes occurred in selenium nanoparticles during the wet heat sterilization process. Therefore, the wet heat sterilization process can be used successfully to recover elemental selenium from bacterial cells. PMID:24031517

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

    PubMed Central

    Misra, Sougat; Boylan, Mallory; Selvam, Arun; Spallholz, Julian E.; Björnstedt, Mikael

    2015-01-01

    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. PMID:25984742

  7. Selenium recovery from kiln powder of cement manufacturing by chemical leaching and bioreduction.

    PubMed

    Soda, S; Hasegawa, A; Kuroda, M; Hanada, A; Yamashita, M; Ike, M

    2015-01-01

    A novel process by using chemical leaching followed by bacterial reductive precipitation was proposed for selenium recovery from kiln powder as a byproduct of cement manufacturing. The kiln powder at a slurry concentration of 10 w/v% with 0.25 M Na2CO3 at 28°C produced wastewater containing about 30 mg-Se/L selenium. The wastewater was diluted four-fold and adjusted to pH 8.0 as preconditioning for bioreduction. A bacterial strain Pseudomonas stutzeri NT-I, capable of reducing selenate and selenite into insoluble elemental selenium, could recover about 90% selenium from the preconditioned wastewater containing selenium of 5 mg-Se/L when supplemented with lactate or glycerol. The selenium concentrations in the treated wastewater were low around the regulated effluent concentration of 0.1 mg-Se/L in Japan. PMID:26465298

  8. Effect of chemical form of selenium on tissue glutathione peroxidase activity in developing rats

    NASA Technical Reports Server (NTRS)

    Lane, Helen W.; Strength, Ralph; Johnson, Janet; White, Marguerite T.

    1991-01-01

    The hypothesis that the stage of development of rats may affect the availability of various forms of selenium for the activity of glutathione peroxidase (GSHPx) in the rat was experimentally investigated. One experiment evaluated the availability of selenium as selenite or selenomethionine for GSPHx activity during three developmental states in rats: fetus and 7-day old and 14-day old nursing pups. In all tissues studied, GSHPx activity was highest in the 14-day-old pups whose dams were in the selenomethionine group. Rat pups given intraperitoneal selenite had higher liver and kidney GSHPx activity than pups given the same amount of selenium as intraperitoneal selenomethionine. In a second experiment, all dams were fed the same basal diet and pups were weaned to diets containing one of two levels of selenium and one of three forms of selenium (selenite, selenomethionine, or selenocystine). The results also supported the hypothesis these dietary forms of selenium are differentially available for GSHPx activity.

  9. Selenium Exposure and Cancer Risk: an Updated Meta-analysis and Meta-regression

    PubMed Central

    Cai, Xianlei; Wang, Chen; Yu, Wanqi; Fan, Wenjie; Wang, Shan; Shen, Ning; Wu, Pengcheng; Li, Xiuyang; Wang, Fudi

    2016-01-01

    The objective of this study was to investigate the associations between selenium exposure and cancer risk. We identified 69 studies and applied meta-analysis, meta-regression and dose-response analysis to obtain available evidence. The results indicated that high selenium exposure had a protective effect on cancer risk (pooled OR = 0.78; 95%CI: 0.73–0.83). The results of linear and nonlinear dose-response analysis indicated that high serum/plasma selenium and toenail selenium had the efficacy on cancer prevention. However, we did not find a protective efficacy of selenium supplement. High selenium exposure may have different effects on specific types of cancer. It decreased the risk of breast cancer, lung cancer, esophageal cancer, gastric cancer, and prostate cancer, but it was not associated with colorectal cancer, bladder cancer, and skin cancer. PMID:26786590

  10. Current Knowledge on the Importance of Selenium in Food for Living Organisms: A Review.

    PubMed

    Kieliszek, Marek; Błażejak, Stanisław

    2016-01-01

    Selenium is one of the elements classified within the group of micronutrients which are necessary in trace amounts for the proper functioning of organisms. Selenium participates in the protection of cells against excess H₂O₂, in heavy metal detoxification, and regulation of the immune and reproductive systems as well. It also ensures the proper functioning of the thyroid gland. Selenium induces the occurrence of the selenoprotein synthesis process involved in the antioxidant defense mechanism of the organism. Recent years have brought much success in the studies on selenium. Anticarcinogenic properties of selenium against some cancers have been reported. Supplementation is increasingly becoming a solution to this problem. A large number of different supplementation methods are promoting studies in this area. Slight differences in the selenium content can result in excess or deficiency, therefore supplementation has to be done carefully and cautiously. PMID:27171069

  11. Antioxidant and antiproliferative activities in different maturation stages of broccoli (Brassica oleracea Italica) biofortified with selenium.

    PubMed

    Bachiega, Patricia; Salgado, Jocelem Mastrodi; de Carvalho, João Ernesto; Ruiz, Ana Lúcia T G; Schwarz, Kélin; Tezotto, Tiago; Morzelle, Maressa Caldeira

    2016-01-01

    In this work, three different broccoli maturity stages subjected to biofortification with selenium were evaluated for antioxidant and antiproliferative activities. Antioxidant trials have shown that the maturation stages biofortified with selenium had significantly higher amounts of phenolic compounds and antioxidant activity, especially seedlings. Although non-polar extracts of all samples show antiproliferative activity, the extract of broccoli seedlings biofortified with selenium stood out, presenting cytocidal activity for a glioma line (U251, GI50 28.5 mg L(-1)). PMID:26213037

  12. Protective effects of selenium on cadmium toxicity in rats: Role of altered toxicokinetics and metallothionein

    SciTech Connect

    Wahba, Z.Z.; Coogan, T.P.; Rhodes, S.W.; Waalkes, M.P. )

    1993-02-01

    Selenium prevents the toxicity of the carcinogenic metal cadmium through undefined mechanisms. In this study, the authors determined the effects of selenium on cadmium toxicokinetics and on the ability of cadmium to induce metallothionein, a metal-binding protein that is thought to confer tolerance to cadmium toxicity. To assess the acute protective effects of selenium, male Wistar (WF/NCr) rats were given selenium (as SeO[sub 2]; 10 [mu]mol/kg, sc) at [minus]24, 0, and +24 h relative to cadmium (as CdCl[sub 2]; 45 [mu]mol/kg, sc). Over a 14-d period this dose of cadmium killed 6 out of 10 rats, while 100% of the cadmium-treated rats given concurrent selenium treatments survived. The acute increases in testicular weight that were seen with cadmium, indicative of edematous damage, were also prevented by concurrent selenium treatments. Further studies assessed the distribution and excretion of cadmium and its ability to induce metallothionein in rats given 40 [mu]mol Cd/kg, sc, at time 0 and selenium (10 [mu]mol/kg, sc) at [minus]24 and 0 h. Selenium treatments enhanced cadmium accumulation at 24 h in the liver (23%), testes (145%), and epididymis (35%) but reduced renal accumulation by more than half. Urine samples, collected at 0-3, 3-6, and 6-24 h following cadmium administration, indicted a markedly reduced excretion of cadmium in selenium treated rats during all time periods. The synthesis of metallothionein was stimulated to a much lesser extent by cadmium in selenium-treated rat kidney (41% decrease) but was unaffected in liver. The levels of cadmium-binding proteins within the testes were markedly reduced by cadmium treatment, an effect unmodified by selenium treatments. These results suggest selenium prevents acute cadmium toxicity through a mechanism that does not involve induction of metallothionein and in spite of a markedly enhanced retention of cadmium. 50 refs., 1 fig., 4 tabs.

  13. The glutaredoxin GLRX-21 functions to prevent selenium-induced oxidative stress in Caenorhabditis elegans.

    PubMed

    Morgan, Kathleen L; Estevez, Annette O; Mueller, Catherine L; Cacho-Valadez, Briseida; Miranda-Vizuete, Antonio; Szewczyk, Nathaniel J; Estevez, Miguel

    2010-12-01

    Selenium is an essential micronutrient that functions as an antioxidant. Yet, at higher concentrations, selenium is pro-oxidant and toxic. In extreme cases, exposures to excess selenium can lead to death or selenosis, a syndrome characterized by teeth, hair and nail loss, and nervous system alterations. Recent interest in selenium as an anti- tumorigenic agent has reemphasized the need to understand the mechanisms underlying the cellular consequences of increased selenium exposure. We show here, that in the nematode, Caenorhabditis elegans, selenium has a concentration range in which it functions as an antioxidant, but beyond this range it exhibits a dose- and time-dependent lethality. Oxidation-induced fluorescence emitted by the dye, carboxy-H(2)DCFDA, indicative of reactive oxygen species formation was significantly higher in animals after a brief exposure to 5mM sodium selenite. Longer-term exposures lead to a progressive selenium-induced motility impairment that could be partially prevented by coincident exposure to the cellular antioxidant-reduced glutathione. The C elegans glrx-21 gene belongs to the family of glutaredoxins (glutathione-dependent oxidoreductases) and the glrx-21(tm2921) allele is a null mutation that renders animals hypersensitive for the selenium-induced motility impairment, but not lethality. In addition, the lethality of animals with the tm2921 mutation exposed to selenium was unaffected by the addition of reduced glutathione, suggesting that GLRX-21 is required for glutathione to moderate this selenium-induced lethality. Our findings provide the first description of selenium-induced toxicity in C elegans and support its use as a model for elucidating the mechanisms of selenium toxicity. PMID:20833709

  14. Multicenter, Phase 3 Trial Comparing Selenium Supplementation With Observation in Gynecologic Radiation Oncology

    SciTech Connect

    Muecke, Ralph; Schomburg, Lutz; Glatzel, Michael; Berndt-Skorka, Regina; Baaske, Dieter; Reichl, Berthold; Buentzel, Jens; Kundt, Guenter; Prott, Franz J.; Vries, Alexander de; Stoll, Guenther; Kisters, Klaus; Bruns, Frank; Schaefer, Ulrich; Willich, Norman; Micke, Oliver

    2010-11-01

    Purpose: We assessed whether adjuvant supplementation with selenium improves the selenium status and reduces side effects of patients treated by radiotherapy (RT) for cervical and uterine cancer. Methods and Materials: Whole-blood selenium concentrations were measured in patients with cervical cancer (n = 11) and uterine cancer (n = 70) after surgical treatment, during RT, at the end of RT, and 6 weeks after RT. Patients with initial selenium concentrations of less than 84{mu}g/L were randomized before RT either to receive 500 {mu}g of selenium (in the form of sodium selenite [selenase (registered) , biosyn Arzneimittel GmbH, Fellbach, Germany]) by mouth on the days of RT and 300 {mu}g of selenium on the days without RT or to receive no supplement during RT. The primary endpoint of this multicenter Phase 3 study was to assess the efficiency of selenium supplementation during RT; the secondary endpoint was to decrease radiation-induced diarrhea and other RT-dependent side effects. Results: A total of 81 patients were randomized. We enrolled 39 in the selenium group (SG) and 42 in the control group (CG). Selenium levels did not differ between the SG and CG upon study initiation but were significantly higher in the SG at the end of RT. The actuarial incidence of diarrhea of Grade 2 or higher according to Common Toxicity Criteria (version 2) in the SG was 20.5% compared with 44.5% in the CG (p = 0.04). Other blood parameters, Eastern Cooperative Oncology Group performance status, and self-reported quality of life were not different between the groups. Conclusions: Selenium supplementation during RT is effective in improving blood selenium status in selenium-deficient cervical and uterine cancer patients and reduces the number of episodes and severity of RT-induced diarrhea.

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

    PubMed Central

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

    2007-01-01

    Background Human health may be improved if dietary intakes of selenium and omega-3 fatty acids are increased. Consumption of broiler meat is increasing, and the meat content of selenium and omega-3 fatty acids are affected by the composition of broiler feed. A two-way analyses of variance was used to study the effect of feed containing omega-3 rich plant oils and selenium enriched yeast on broiler meat composition, antioxidation- and sensory parameters. Four different wheat-based dietary treatments supplemented with 5% rapeseed oil or 4% rapeseed oil plus 1% linseed oil, and either 0.50 mg selenium or 0.84 mg selenium (organic form) per kg diet was fed to newly hatched broilers for 22 days. Results The different dietary treatments gave distinct different concentrations of selenium and fatty acids in thigh muscle; one percent linseed oil in the diet increased the concentration of the omega-3 fatty acids 18:3, 20:5 and 22:5, and 0.84 mg selenium per kg diet gave muscle selenium concentration at the same level as is in fish muscle (0.39 mg/kg muscle). The high selenium intake also resulted in increased concentration of the long-chain omega-3 fatty acids EPA (20:5), DPA (22:5) and DHA (22:6), thus it may be speculated if high dietary selenium might have a role in increasing the concentration of EPA, DPA and DHA in tissues after intake of plant oils contning omega-3 fatty acids. Conclusion Moderate modifications of broiler feed may give a healthier broiler meat, having increased content of selenium and omega-3 fatty acids. High intakes of selenium (organic form) may increase the concentration of very long-chain omega-3 fatty acids in muscle. PMID:17967172

  16. Consequences of vapor enhancement on selenium speciation analysis by HPLC/ICPMS.

    PubMed

    Juresa, Dijana; Kuehnelt, Doris; Francesconi, Kevin A

    2006-12-15

    Recent work has shown the presence of volatile selenium metabolites in human urine and suggested that these compounds could compromise quantitative selenium analyses by ICPMS. We show that with a commonly used sample introduction system (pneumatic nebulizer and spray chamber), two volatile selenium species recently identified in urine, namely, dimethyl selenide and dimethyl diselenide, gave greatly increased ICPMS responses (up to 58-fold) relative to selenite, an effect related to their volatilization in the spray chamber resulting in enhanced transport to the plasma. The quantitative consequences of this effect were demonstrated by measurement of total selenium and selenium species in certified reference material, NIES CRM 18 human urine. Direct flow injection analysis of the urine gave a total selenium concentration more than 2-fold higher than the certified value. These data suggested that NIES CRM 18 may contain part of its selenium as volatile species, and subsequent reversed-phase HPLC/ICPMS showed the presence of dimethyl selenide in addition to selenosugars and trimethylselenonium ion. Although the practice of quantifying unidentified chromatographic peaks against those of known compounds is common in speciation analysis, this approach when applied to NIES CRM 18 gave a value for the sum of selenium species which was twice the certified total selenium concentration. This work shows that the presence of volatile selenium species in urine precludes the use of flow injection analysis for total selenium measurements and imposes severe restrictions on the quantification of urinary selenium metabolites. In addition, it raises broader issues of the validity of the "dilute and shoot" approach to the determination of metals in clinical analysis of biological fluids. PMID:17165855

  17. Association of percentile ranking with citation impact and productivity in a large cohort of de novo NIMH-funded R01 grants.

    PubMed

    Doyle, J M; Quinn, K; Bodenstein, Y A; Wu, C O; Danthi, N; Lauer, M S

    2015-09-01

    Previous reports from National Institutes of Health and National Science Foundation have suggested that peer review scores of funded grants bear no association with grant citation impact and productivity. This lack of association, if true, may be particularly concerning during times of increasing competition for increasingly limited funds. We analyzed the citation impact and productivity for 1755 de novo investigator-initiated R01 grants funded for at least 2 years by National Institute of Mental Health between 2000 and 2009. Consistent with previous reports, we found no association between grant percentile ranking and subsequent productivity and citation impact, even after accounting for subject categories, years of publication, duration and amounts of funding, as well as a number of investigator-specific measures. Prior investigator funding and academic productivity were moderately strong predictors of grant citation impact. PMID:26033238

  18. Thoracic response targets for a computational model: a hierarchical approach to assess the biofidelity of a 50th-percentile occupant male finite element model.

    PubMed

    Poulard, David; Kent, Richard W; Kindig, Matthew; Li, Zuoping; Subit, Damien

    2015-05-01

    Current finite element human thoracic models are typically evaluated against a limited set of loading conditions; this is believed to limit their capability to predict accurate responses. In this study, a 50th-percentile male finite element model (GHBMC v4.1) was assessed under various loading environments (antero-posterior rib bending, point loading of the denuded ribcage, omnidirectional pendulum impact and table top) through a correlation metric tool (CORA) based on linearly independent signals. The load cases were simulated with the GHBMC model and response corridors were developed from published experimental data. The model was found to be in close agreement with the experimental data both qualitatively and quantitatively (CORA ratings above 0.75) and the response of the thorax was overall deemed biofidelic. This study also provides relevant corridors and an objective rating framework that can be used for future evaluation of thoracic models. PMID:25681717

  19. Sulfur and Selenium in Chondritic Meteorites

    NASA Astrophysics Data System (ADS)

    Dreibus, G.; Palme, H.; Spettel, B.; Wanke, H.

    1993-07-01

    Selenium is the only truly chalcophile element in chondritic meteorites. It has no other host phases except sulfides. Since Se-volatility is similar to S-volatility one may expect constant S/Se ratios. To test this hypothesis chondritic meteorites were analyzed for Se and S. To avoid problems from inhomogeneous distribution of sulfides the same samples that had been analyzed for Se by INAA were analyzed for S (see Table 1) using a Leybold Heraeus Carbon and Sulfur Analyser (CSA 2002). Solar System Abundances of S and Se: The average S-content of CI- meteorites is with 5.41% in agreement with an earlier average of 5.25% for Orgueil [1], but not with higher S-contents for Ivuna, Alais, and Tonk. Inclusion of these data led to an average CI- content of 6.25% in the Anders and Grevesse compilation [2]. The essentially constant average S/Se ratio in all groups of carbonaceous chondrites of 2563 +- 190 suggests that our Orgueil S-content provides a reliable estimate for the average solar system. The new solar S/Se ratio and the CI-value of Se of 21.3 ppm [3] yield an atomic S/Se ratio of 6200 +- 170, 24% below that calculated from [2]. Weathering Effects: Some of the carbonaceous chondrite finds have similar S/Se ratios as falls (see Table 1). However the badly- weathered Arch (CVR) and Colony (CO) and the two C4-chondrites Mulga West and Maralinga have much lower S and somewhat lower Se contents compared to unweathered meteorites. Their S/Se ratios of 1000-230 indicate higher losses of S--probably by oxidation--as of Se. The low Na-contents in Arch and Colony rel. to CV3 and CO3 may also reflect weathering. Low S/Se ratios in the Sahara meteorites are also indicative of weathering processes. The depletion factors for the CV3- chondrite Acfer086 are, relative to average CV, 10 (S), 5 (Se), 6 (Na), and 4 (Ni). Lower absolute depletions, but the same depletion sequence are found for the CO-meteorite Acfer 202. In the CO/CM Acfer 094 only S and Na are depleted. The

  20. The two faces of selenium-deficiency and toxicity--are similar in animals and man.

    PubMed Central

    Koller, L D; Exon, J H

    1986-01-01

    The purpose of this review article is to demonstrate the close parallelism of daily requirements, biological activity and minimum and maximum tolerable levels of selenium for animals and man. In addition, the carcinogenic/anticarcinogenic properties of selenium are discussed and a postulate of how these dichotomous effects may occur in accordance with selenium-induced immunomodulation is presented. A review of pertinent literature pertaining to the biological action of selenium in animals and man, including deficiency, toxicity, carcinogenicity and effects on immunity, is included to support these concepts. The predominant biochemical action of selenium in both animals and man is to serve as an antioxidant via the selenium-dependent enzyme, glutathione peroxidase, and thus protect cellular membranes and organelles from peroxidative damage. The signs and symptoms of selenium deficiency closely simulate each other for animals and man. Severe deficiency is characterized by cardiomyopathy while moderate deficiency results in less severe, myodegenerative syndromes such as muscular weakness and pain as well as a variety of other selenium-associated diseases. Clinical manifestations of many of these disorders require contributory factors, such as stress, to precipitate symptoms which are documented for animals and implicated for humans. Current evidence suggests that a daily selenium consumption for man of approximately 30 micrograms is necessary to prevent the selenium-deficient syndrome, Keshan disease, while approximately 90 micrograms/day/adult should be the minimum daily requirement for optimum biological performance. Recognizing that humans in several countries do not meet the proposed minimum daily requirement of 90 micrograms, several compelling reasons are presented in deriving this minimal daily nutritional intake. Selenosis can occur in laboratory animals, livestock, and humans following long-term exposure to selenium concentrations as low as 5 mg selenium

  1. A STUDY OF THE ASSOCIATION BETWEEN SELENIUM AND CARDIOVASCULAR DISEASE IN LAMPUNG, INDONESIA.

    PubMed

    Mutakin; Rivai, Ida F; Setiawan, Andi; Abdulah, Rizky; Kobayashi, Kenji; Yamazaki, Chiho; Kameo, Satomi; Nakazawa, Minato; Koyama, Hiroshi

    2016-03-01

    Selenium deficient areas have been associated with a higher prevalence of cardiovascular disease in some countries. In this study, we investigated the correlation between cardiovascular disease prevalence and selenium concentration in paddy soil and rice grains, the main staple food in Lampung, Indonesia. Paddy soil and rice samples (n(s) = 35) from eight regencies (n(d) = 8) in Lampung were analyzed for selenium content. The prevalences of heart disease, stroke, and hypertension in those regencies were obtained from the Ministry of Health of Indonesia. The Shapiro-Wilk's test was used to examine the data distribution. The Pearson's correlation was used to examine the correlation between cardiovascular disease prevalence and selenium concentration in the paddy soil and rice grains. Heart disease prevalence was negatively correlated with the selenium concentration in the paddy soil (r = -0.77, p = 0.02) and rice grain (r = -0.71, p = 0.05). A negative correlation was seen for stroke prevalence and selenium concentration in paddy soil (r = -0.76, p = 0.02). Hypertension prevalence was negatively correlated with the selenium concentration in the rice grains (r = -0.83, p = 0.01). These findings suggest that the selenium concentration in paddy soil and rice grains in the Lampung area may play a role in the fact the area has the lowest cardiovascular disease prevalence in Indonesia. Keywords: selenium, cardiovascular diseases, paddy soil, rice grain, Indonesia PMID:27244968

  2. Selenium accumulation by raccoons exposed to irrigation drainwater at Kesterson National Wildlife Refuge, California, 1986

    USGS Publications Warehouse

    Clark, D.R., Jr.; Ogasawara, P.A.; Smith, G.J.; Ohlendorf, H.M.

    1989-01-01

    Selenium concentrations in liver, hair, feces, and blood of Kesterson raccoons exceeded Volta concentrations by 12, 30, 21 and 10 times, respectively. Selenium concentrations in hair provided the strongest statistical separation between areas. Selenium concentrations in livers of Kesterson raccoons were less than those found in five of nine other species of mammals sampled in 1984. Hence, the raccoon did not appear unusual in its accumulation of selenium. Based on our sample of 12 raccoons, we found no evidence that contamination by irrigation drainwater had negative effects on the raccoon population at Kesterson.

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

    USGS Publications Warehouse

    Franson, J.C.; Hoffman, D.J.; Schmutz, J.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 feathera??molting 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.

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

    USGS Publications Warehouse

    Franson, J.C.; Hoffman, D.J.; Schmutz, J.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.

  5. Ionoregulatory responses of the crayfish Orconectes immunis to selenium in fresh water

    SciTech Connect

    Short, T.M.

    1983-01-01

    The purpose of this study was to investigate the effects of chronic exposure to sublethal concentrations of selenium on fluid and tissue electrolyte balance of the crayfish Orconcectes immunis. An ionic profile of O. immunis was obtained from measurements of hemolymph sodium, potassium, calcium, magnesium, and copper in several populations of crayfish in eastern Colorado. The bioassay portion of the study consisted of groups of crayfish maintained in reconstituted fresh water while exposed for 30 days to concentrations of 0.01 mg/liter, 0.10 mg/liter, or 1.00 mg/liter selenium as sodium selenite. Exposure to selenium resulted in various branchial histopathologies to include hypertrophy, necrosis, and sloughing of the cuticular membrane. Hemolymph potassium and copper, however, were significantly reduced in crayfish exposed for 10 days to 1.00 mg/liter selenium and 30 days to 0.10 mg/liter selenium. Copper appeared to be the more responsive to selenium toxicity with reductions of 47.4%-53.7% in hemolymph levels after exposure for 30 days to 1.00 mg/liter selenium. Selenium-induced changes in tissue ionic content (abdominal muscle and carapace) were most evident with respect to muscle levels of potassium and calcium. It is suggested that the observed alterations in fluid and tissue ionic content are largely in response to changes in concentration or electrochemical potential gradients brought about by selenium-induced disturbance of membrance permeability and ionic transport characteristics.

  6. Microarray Data Mining for Potential Selenium Targets in Chemoprevention of Prostate Cancer

    PubMed Central

    ZHANG, HAITAO; DONG, YAN; ZHAO, HONGJUAN; BROOKS, JAMES D.; HAWTHORN, LESLEYANN; NOWAK, NORMA; MARSHALL, JAMES R.; GAO, ALLEN C.; IP, CLEMENT

    2008-01-01

    Background A previous clinical trial showed that selenium supplementation significantly reduced the incidence of prostate cancer. We report here a bioinformatics approach to gain new insights into selenium molecular targets that might be relevant to prostate cancer chemoprevention. Materials and Methods We first performed data mining analysis to identify genes which are consistently dysregulated in prostate cancer using published datasets from gene expression profiling of clinical prostate specimens. We then devised a method to systematically analyze three selenium microarray datasets from the LNCaP human prostate cancer cells, and to match the analysis to the cohort of genes implicated in prostate carcinogenesis. Moreover, we compared the selenium datasets with two datasets obtained from expression profiling of androgen-stimulated LNCaP cells. Results We found that selenium reverses the expression of genes implicated in prostate carcinogenesis. In addition, we found that selenium could counteract the effect of androgen on the expression of a subset obtained from androgen-regulated genes. Conclusions The above information provides us with a treasure of new clues to investigate the mechanism of selenium chemoprevention of prostate cancer. Furthermore, these selenium target genes could also serve as biomarkers in future clinical trials to gauge the efficacy of selenium intervention. PMID:18548127

  7. Selenium in a Wyoming grassland community receiving wastewater from an in situ uranium mine.

    PubMed

    Ramirez, P; Rogers, B P

    2002-05-01

    Water, soil, vegetation, grasshoppers, bird eggs, and bird livers collected at a 23.5-ha (58 acres) grassland irrigated with wastewater from an in situ uranium mine (study area) and a reference site in 1998 were analyzed for selenium and other trace elements. Selenium concentrations in the uranium mine wastewater applied onto the grassland ranged from 340 to 450 microg/L. Selenium in the upper 15 cm (6 in) of soil from the irrigated grassland at the mine ranged from 2.6 to 4.2 microg/g dry weight (DW). Mean selenium concentrations in soil and water were 5 and 15 times higher at the study area than at the reference site. Selenium concentrations in grasses and grasshoppers ranged from 6.8 to 24 microg/g and 11 to 20 microg/g DW, respectively. Selenium in red-winged blackbird eggs and livers collected from the study area ranged from 13.2 to 22 microg/g and 33 to 53 microg/g DW, respectively, and concentrations were well in excess of toxic thresholds. Mean selenium concentrations in grasses, grasshoppers, and bird eggs and livers were 5.8 to 30 times higher at the study area than at the reference site. Elevated selenium concentrations in water, soil, grasshoppers, and red-winged blackbird eggs and livers collected from the study area demonstrate that selenium is being mobilized and is bioaccumulating in the food chain. PMID:11994784

  8. Occurrence of selenium in sulfides from some sedimentary rocks of the western United States

    USGS Publications Warehouse

    Coleman, Robert G.; Delevaux, Maryse

    1956-01-01

    Investigations of the minor- and trace-element content of sulfides associated with uranium ore deposits from sandstone-type deposits have shown that selenium commonly substitutes for sulfur. The Morrison formation and Entrada sandstone of Jurassic age and the Wind River formation of Eocene age seem to be seleniferous stratigraphic zones; sulfides deposited within these formations generally contain abnormal amounts of selenium. The selenium content of the pyrite, marcasite, and chalcocite is much greater than that reported in previously published data. Under the prevailing temperatures and pressures of formation of the Colorado Plateau uranium deposits the maximum amount of Se substituting for S in the pyrite structure was found to be 3 percent by weight. Ferroselite, the iron selenide (FeSe2), was found in two deposits on the Colorado Plateau and it was also established that galena (PbS) forms an isomorphous series with clausthalite (PbSe) in nature. During oxidation of the selenium-bearing sulfides and selenides in the Colorado Plateau and Wyoming, the selenium forms pinkish crusts of either monoclinic or hexagonal native selenium intergrown with soluble sulfates, suggesting that under "normal" oxidizing conditions native selenium is more stable than selenites or selenates. The above-normal selenium content of these sulfides from sedimentary rocks of Mesozoic and Tertiary age is significant. The high selenium in these sulfides is related to periods of volcanic and intrusive activity penecontemporaneous with the formation of the containing sediments.

  9. Temporal measurements and kinetics of selenium release during coal combustion and gasification in a fluidized bed.

    PubMed

    Shen, Fenghua; Liu, Jing; Zhang, Zhen; Yang, Yingju

    2016-06-01

    The temporal release of selenium from coal during combustion and gasification in a fluidized bed was measured in situ by an on-line analysis system of trace elements in flue gas. The on-line analysis system is based on an inductively coupled plasma optical emission spectroscopy (ICP-OES), and can measure concentrations of trace elements in flue gas quantitatively and continuously. The results of on-line analysis suggest that the concentration of selenium in flue gas during coal gasification is higher than that during coal combustion. Based on the results of on-line analysis, a second-order kinetic law r(x)=0.94e(-26.58/RT)(-0.56 x(2) -0.51 x+1.05) was determined for selenium release during coal combustion, and r(x)=11.96e(-45.03/RT)(-0.53 x(2) -0.56 x+1.09) for selenium release during coal gasification. These two kinetic laws can predict respectively the temporal release of selenium during coal combustion and gasification with an acceptable accuracy. Thermodynamic calculations were conducted to predict selenium species during coal combustion and gasification. The speciation of selenium in flue gas during coal combustion differs from that during coal gasification, indicating that selenium volatilization is different. The gaseous selenium species can react with CaO during coal combustion, but it is not likely to interact with mineral during coal gasification. PMID:26897573

  10. Selenium in mainstream and sidestream smoke of cigarettes containing fly ash-grown tobacco

    SciTech Connect

    Gutenmann, W.H.; Lisk, D.J.; Shane, B.S.; Hoffmann, D.; Adams, J.D.

    1987-01-01

    The quantities of selenium, tar and nicotine present in mainstream (MS) and sidestream (SS) smoke of machine-smoked cigarettes was studied. The cigarettes were prepared from tobacco purposely cultured on fly ash-amended soil so as to increase its selenium concentration. Selenium concentration was found to be the same in the gaseous phase of both MS and SS smoke, but its concentration was significantly higher (p less than 0.05) in the particulate matter of the MS smoke. Tar was higher in MS smoke and nicotine in SS smoke. Factors affecting selenium concentrations in tobacco and its possible environmental significance are discussed.

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

    PubMed Central

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

    2015-01-01

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

  12. Selenium in mainstream and sidestream smoke of cigarettes containing fly ash-grown tobacco.

    PubMed

    Gutenmann, W H; Lisk, D J; Shane, B S; Hoffmann, D; Adams, J D

    1987-01-01

    The quantities of selenium, tar and nicotine present in mainstream (MS) and sidestream (SS) smoke of machine-smoked cigarettes was studied. The cigarettes were prepared from tobacco purposely cultured on fly ash-amended soil so as to increase its selenium concentration. Selenium concentration was found to be the same in the gaseous phase of both MS and SS smoke, but its concentration was significantly higher (p less than 0.05) in the particulate matter of the MS smoke. Tar was higher in MS smoke and nicotine in SS smoke. Factors affecting selenium concentrations in tobacco and its possible environmental significance are discussed. PMID:3428180

  13. Field-Measured Oxidation Rates of Biologically Reduced Selenium in Sludge

    SciTech Connect

    Benson, Sally M.; Daggett, John; Zawislansi, Peter

    1999-05-01

    Sludge generated during surface-water transport or biological treatment of selenium laden agricultural drainage water contains high concentrations (20-100 mg/kg) of selenium. Finding safe and economical sludge disposal methods requires understanding of the biogeochemical processes that change selenium speciation (after placed at a disposal site). Two experiments, each comparing 3 treatments for sludge disposal has resulted in data on changes in selenium speciation spanning an eight year period. Treatments included direct application to upland soils and application with tillage to depths of 15 cm and 30 cm. Soil cores, soil water samples and groundwater monitoring were used to track changes in selenium speciation and transport of re-oxidized forms of selenium. Measurements demonstrate the slow re-oxidation of reduced forms of selenium, largely elemental and organically associated forms, to selenate and selenite. Downward transport of these re-oxidized forms of selenium are driven by winter rains. Field measured re-oxidation rates for these field trials are presented and compared to selenium re-oxidation rates in formerly ponded areas at Kesterson Reservoir, California.

  14. [Assessment of efficiency of use of the developed supplement containing selenium on laboratory animals].

    PubMed

    Bazhenova, B A; Aslaliev, A D; Danilov, M B; Badmaeva, T M; Vtorushina, I A

    2015-01-01

    The article presents the results of a study of the effectiveness of wheat flour containing selenium in organic form. The organic form of trace element was achieved by transformation of selenium in selenium-methionine (Se-Met) at germination of wheat grains, moistened with a solution of sodium selenite. To determine the effectiveness of selenium- containing supplements experimental investigations were carried out on Long white rats with initial body weight 50 ± 2 g. The duration of the experiment was 30 days. The research model included four groups of animals: control group--animals were fed a complete vivarium diet; group 1--a model of selenium deficiency, which was achieved by feeding selenium-deficient food (grain growh in the Chita region of the Trans-Baikal Territory Zabaikalsky Krai); group 2--animals were administered selenium supplement in the form of enriched flour (0.025 µg Se per 50 g body weight of the animal) on the background of selenium-deficient diet; group 3--animals were treated with a high dose of selenium in the form of a solution of sodium selenite intragastrically through a tube (0.15 µg Se per 50 g body weight). Selenium-containing additive on the background of selenium-deficient diet had a positive impact on the appearance and behavior of animals, the body weight gain per head after 10 days in group 2 amounted to 47.9 g that was 4 fold larger than in rats of group 1. The study of selenium content showed that in the blood, liver, lungs and heart of rats treated with the additive on the background of selenium-deficient diet (group 2), selenium level did not differ from those in the control group and was within physiological norms. The experiment showed that selenium deficiency and rich in selenium rich diet has a significantly different effect on the studied parameters of oxidative-antioxidative status. The activity of blood glutathione peroxidase in animals of group 2 (did not differ from that in group 3) was almost 2 fold higher than in

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

    PubMed Central

    Stoffaneller, Rita; Morse, Nancy L.

    2015-01-01

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

  16. Prepartum supplementation of selenium and vitamin E to dairy cows: assessment of selenium and reproductive performance

    SciTech Connect

    Hidiroglou, M.; McAllister, A.J.; Williams, C.J.

    1987-06-01

    Incidence of retained placenta in dairy cows was evaluated in 627 parturitions. The herd was divided prepartum into three groups: (1) control, no treatment (n = 217 cows); (2) cows injected intramuscularly (n = 190) 21 to 10 d prior parturition with 45 mg Se and 2040 IU of vitamin E; and (3) cows intraruminally administered (n = 220) with two 30-g pellets containing 10% elemental selenium 2 mo prior to expected calving. Incidence of retained placenta (22.1%) was not reduced by Se in combination with vitamin E injection or intraruminal Se pellet nor were other measures of reproduction improved for cows fed a prepartum diet adequate in Se. At parturition the blood plasma Se concentrations were higher in treated postpartum with Se than in untreated cows. No difference in blood plasma Se was observed at parturition between cows with or without placenta retention. Cows dosed intraruminally with Se had a significant increase in milk Se, but this was to small to be a danger to human health. The present results on placenta retention suggest that this disorder is not a Se responsive disease in the dairy cow.

  17. Effects of selenium biofortification on crop nutritional quality

    PubMed Central

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

    2015-01-01

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

  18. The Role of Iodine and Selenium in Autoimmune Thyroiditis.

    PubMed

    Duntas, L H

    2015-09-01

    Iodine and selenium (Se) are both essential elements to thyroid hormone economy, while they represent key players in the development of autoimmune thyroiditis.Chronic high iodine intake has been associated in various studies with increased frequency of autoimmune thyroiditis. In susceptible individuals, iodine excess increases intra-thyroid infiltrating Th17 cells and inhibits T regulatory (TREG) cells development, while it triggers an abnormal expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in thyrocytes, thus inducing apoptosis and parenchymal destruction. As was shown in a mouse model, high iodine supply leads to changes in the immunogenicity of the thyroglobulin molecule, upregulation of vascular intercellular adhesion molecule-1 (ICAM-1), and reactive oxygen species (ROS) generation in the thyrocytes. Serum Se levels were found decreased in Hashimoto thyroiditis and especially in Graves' disease as well as in thyroid-associated ophthalmopathy patients, the levels being related to the pathogenesis and outcome. Selenium is strongly involved, via the variable selenoproteins, in antioxidant, redox, and anti-inflammatory processes. Selenium enhances CD4+/CD25 FOXP3 and T regulatory cells activity while suppressing cytokine secretion, thus preventing apoptosis of the follicular cells and providing protection from thyroiditis. Selenium supplementation may be useful in autoimmune thyroid diseases, though, while usually well-tolerated, it should not be universally recommended, and it is also likely to be helpful for those with low Se status and autoimmunity. Broadly speaking, the achievement and maintenance of "selenostasis" as well as adequate urinary iodine excretion are mandatory to control disease, while, putatively, they may additionally be critical to preventing disease. PMID:26361258

  19. Differing views of the role of selenium in thioredoxin reductase

    PubMed Central

    Ruggles, Erik L.

    2010-01-01

    This review covers three different chemical explanations that could account for the requirement of selenium in the form of selenocysteine in the active site of mammalian thioredoxin reductase. These views are the following: (1) the traditional view of selenocysteine as a superior nucleophile relative to cysteine, (2) the superior leaving group ability of a selenol relative to a thiol due to its significantly lower pKa and, (3) the superior ability of selenium to accept electrons (electrophilicity) relative to sulfur. We term these chemical explanations as the “chemico-enzymatic” function of selenium in an enzyme. We formally define the chemico-enzymatic function of selenium as its specific chemical property that allows a selenoenzyme to catalyze its individual reaction. However we, and others, question whether selenocysteine is chemically necessary to catalyze an enzymatic reaction since cysteine-homologs of selenocysteine-containing enzymes catalyze their specific enzymatic reactions with high catalytic efficiency. There must be a unique chemical reason for the presence of selenocysteine in enzymes that explains the biological pressure on the genome to maintain the complex selenocysteine-insertion machinery. We term this biological pressure the “chemico-biological” function of selenocysteine. We discuss evidence that this chemico-biological function is the ability of selenoenzymes to resist inactivation by irreversible oxidation. The way in which selenocysteine confers resistance to oxidation could be due to the superior ability of the oxidized form of selenocysteine (Sec-SeO2−, seleninic acid) to be recycled back to its parent form (Sec-SeH, selenocysteine) in comparison to the same cycling of cysteine-sulfinic acid to cysteine (Cys-SO2− to Cys-SH). PMID:20397034

  20. Selenazolidine: a selenium containing proline surrogate in peptide science.

    PubMed

    Cordeau, E; Cantel, S; Gagne, D; Lebrun, A; Martinez, J; Subra, G; Enjalbal, C

    2016-09-14

    In the search for new peptide ligands containing selenium in their sequences, we investigated l-4-selenazolidine-carboxylic acid (selenazolidine, Sez) as a proline analog with the chalcogen atom in the γ-position of the ring. In contrast to proteinogenic selenocysteine (Sec) and selenomethionine (SeMet), the incorporation within a peptide sequence of such a non-natural amino acid has never been studied. There is thus a great interest in increasing the possibility of selenium insertion within peptides, especially for sequences that do not possess a sulfur containing amino acid (Cys or Met), by offering other selenated residues suitable for peptide synthesis protocols. Herein, we have evaluated selenazolidine in Boc/Bzl and Fmoc/tBu strategies through the synthesis of a model tripeptide, both in solution and on a solid support. Special attention was paid to the stability of the Sez residue in basic conditions. Thus, generic protocols have been optimized to synthesize Sez-containing peptides, through the use of an Fmoc-Xxx-Sez-OH dipeptide unit. As an example, a new analog of the vasopressin receptor-1A antagonist was prepared, in which Pro was replaced with Sez [3-(4-hydroxyphenyl)-propionyl-d-Tyr(Me)-Phe-Gln-Asn-Arg-Sez-Arg-NH2]. Both proline and such pseudo-proline containing peptides exhibited similar pharmacological properties and endopeptidase stabilities indicating that the presence of the selenium atom has minimal functional effects. Taking into account the straightforward handling of Sez as a dipeptide building block in a conventional Fmoc/tBu SPPS strategy, this result suggested a wide range of potential uses of the Sez amino acid in peptide chemistry, for instance as a viable proline surrogate as well as a selenium probe, complementary to Sec and SeMet, for NMR and mass spectrometry analytical purposes. PMID:27506250

  1. Characterization of photodeposited selenium planar structures by scanning force microscopy

    NASA Astrophysics Data System (ADS)

    Peled, A.; Baranauskas, V.; Rodrigues, C.; Art-Weisman, D.; Grantman, L.; Friesem, A. A.

    1995-06-01

    This article describes the results of a surface morphology study of photodeposited thin film devices of Selenium by scanning force microscopy (SFM). First, the structures of the photodeposited films were investigated at device level dimensions of the order of visible wavelength. Specifically, ultrathin sinusoidal holographic gratings with spatial periods in the range 480-514 nm were visually identified from SFM nanograph images. Second, grain level structural investigation was performed using image processing techniques such as filtering and one- and two-dimensional Fourier transforms analysis. The variation of the surface grain structure was sampled across the Gaussian profiles of the laser photodeposited patterns. It was found that the random amorphous clustering at the perimeter of the deposited structures becomes progressively grainy towards the center, creating protrusions above the surface with trigonal Selenium (t-Se) crystalline features. Third, performing image enhancement analysis at high magnification—the nanometer level structure was investigated for amorphous Selenium (a-Se) and the laser thermally induced structural transformations of the a-Se films. It was found that the atomic solid-state structure of a-Se films, previously deduced only by indirect methods, consists mainly of a random mixture of Sex branched chains containing also a small concentration of imperfect ring structures characteristic of the α- and β-monoclinic phases. The triclinic crystalline phase (t-Se) was identified in the center of the laser overheated regions of the film Gaussian profile. The results enable us to conclude about the debate in the literature regarding the crystalline and amorphous structure of Selenium thin films.

  2. Selenium Distribution and Fractionation in a Managed Urban Watershed

    NASA Astrophysics Data System (ADS)

    Papelis, C.; Boettcher, T. M.; Harris-Burr, R. D.

    2006-12-01

    Metals, and metalloids, are common contaminants of concern in arid and semi-arid watersheds in the Southwestern U.S. Because of the dramatic population growth in this part of the U.S., the potential for contamination of urban watersheds has also increased over the last few decades. Streams in urban watersheds receive storm water, urban runoff, shallow groundwater, and treated wastewater. In addition, urban watersheds are often heavily managed to mitigate flood events and sediment-related impacts. Clearly, sediment transport can have a profound effect on the water quality of affected bodies of water, not only by affecting water clarity, but also by facilitating the transport of chemical constituents, as well as microbiological components. The Las Vegas Wash (Wash) is the lowest point in the Las Vegas Valley Watershed and receives storm water, urban runoff, and treated wastewater from the entire Las Vegas Valley. To minimize erosion, caused by the dramatic wastewater flow increase during the last few decades, several erosion control structures are being built. In addition, wetlands being constructed in the Wash area receive most of the water from the Wash. The construction of these ponds has the potential to alter the distribution of metals and metalloids in bodies of water used by wildlife. An element of particular concern is selenium, a metalloid commonly found at elevated concentrations in soils of the U.S. Southwest. To assess the potential adverse impact on water quality, sediment samples were collected along the Wash, upstream and downstream of erosion control structures, and around current and future constructed wetlands. The sediments were characterized by particle size distribution, specific surface area, mineralogical composition, organic carbon content, and scanning electron microscopy. The total selenium, as well as the percentages associated with exchangeable, organic, carbonate, and oxide sediment fractions were determined. The distribution of selenium

  3. Environmental impact assessment of selenium from coal mine spoils

    SciTech Connect

    Atalay, A.

    1990-10-01

    The development of environmental impact assessment of selenium from coal mine spoils will provide a useful guideline to predict the environmental impact of Se from abandoned coal mine operations. Information obtained from such a study can be applied in areas where coal mining has not yet begun in order to predict and identify the geochemistry of rocks, soils, surface waters and groundwaters likely to be disturbed by coal mining operation.

  4. Plasma selenium concentrations are sufficient and associated with protease inhibitor use in treated HIV-infected adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Selenium (Se) is an essential constituent of selenoproteins which play significant roles in antioxidant defense and inflammatory cascades. Selenium deficiency is associated with disease states characterized by inflammation including cardiovascular disease (CVD). While HIV infection has b...

  5. Serum selenium concentrations and diabetes in U.S. adults: National Health and Nutrition Examination Survey (NHANES) 2003-2004

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Increasing evidence suggests that high selenium levels are associated with diabetes and other cardiometabolic risk factors. OBJECTIVES: We evaluated the association of serum selenium concentrations with fasting plasma glucose, glycosylated hemoglobin levels, and diabetes in the most rec...

  6. Adsorption mechanism of selenium(VI) onto maghemite

    NASA Astrophysics Data System (ADS)

    Jordan, N.; Ritter, A.; Foerstendorf, H.; Scheinost, A. C.; Weiß, S.; Heim, K.; Grenzer, J.; Mücklich, A.; Reuther, H.

    2013-02-01

    In this study, the sorption properties of maghemite (γ-Fe2O3) towards selenium(VI) were studied for the first time both on the macroscopic and the molecular level. Using batch experiments, we found that the retention reaction was very fast. Both increase of pH and ionic strength led to a decrease of selenium(VI) sorption. Electrophoretic mobility measurements showed that selenium(VI) sorption had no significant effect on the isoelectric point of maghemite. These macroscopic results strongly suggested the formation of outer-sphere complexes across the investigated pH range (3.5-8.0). At the molecular level, the structure of the sorbed surface species was elucidated in situ using Attenuated Total Reflection Fourier-Transform Infrared (ATR FT-IR) spectroscopy and Extended X-ray Absorption Fine-Structure (EXAFS) spectroscopy. The ATR FT-IR results suggested the formation of outer-sphere complexes showing an unexpected bidentate symmetry, which possibly revealed the lack of accuracy of the actual widely-used classification of inner- and outer-sphere coordination for anionic species. EXAFS results revealed, that in addition to outer-sphere complexes, there is also a small (15%) contribution of an inner-sphere complex in binuclear corner-sharing geometry present.

  7. Thiolated eggshell membranes sorb and speciate inorganic selenium.

    PubMed

    Yang, Ting; Chen, Ming-Li; Hu, Xian-Wei; Wang, Zhao-Wen; Wang, Jian-Hua; Dasgupta, Purnendu K

    2011-01-01

    Eggshell membranes (ESMs) provide a unique, disulfide bond-rich surface. Thioglycolate reduction was used to generate thiol (-SH) groups on the ESM surface by S-S bond cleavage. The thiol-bearing ESMs (TESMs) were characterized by scanning electron microscopy and Raman spectroscopy. The fibrous network structure of the ESM is retained in the TESMs. TESMs adsorb both Se(IV) and Se(VI) but by different mechanisms: Se(VI) is retained reversibly, possibly via ionic interactions, while Se(IV) is reduced to Se(0) and deposited. We thus demonstrate speciation of selenium species, by using samples (a) as such and after prior oxidation to Se(VI), (b) preconcentration on a TESM microcolumn, (c) elution by 0.5 M HNO(3) that only elutes Se(VI) and (d) detection by graphite furnace atomic absorption spectrometry (GFAAS). The Se(IV) amount is determined by difference. For a 1.0 mL sample, the enrichment factor was 17.2, the S/N = 3 detection limit was 0.06 μg L(-1) and the precision was 3.3% at 0.50 μg L(-1). The linear range was 0.25-2.50 μg L(-1). The procedure was validated by analyzing selenium in certified reference materials of human hair (GBW 09101) and rice (GBW 10010). We further demonstrate utility by speciation of inorganic selenium in a series of water samples. PMID:20877887

  8. Epigenetic effects of selenium and their implications for health

    PubMed Central

    Speckmann, Bodo; Grune, Tilman

    2015-01-01

    Alterations of epigenetic marks are linked to normal development and cellular differentiation as well as to the progression of common chronic diseases. The plasticity of these marks provides potential for disease therapies and prevention strategies. Macro- and micro-nutrients have been shown to modulate disease risk in part via effects on the epigenome. The essential micronutrient selenium affects human health outcomes, e.g., cancers, cardiovascular and autoimmune diseases, via selenoproteins and through a range of biologically active dietary selenocompounds and metabolism products thereof. This review provides an assessment of the current literature regarding epigenetic effects of dietary and synthetic selenocompounds, which include the modulation of marks and editors of epigenetic information and interference with one-carbon metabolism, which provides the methyl donor for DNA methylation. The relevance of a selenium-epigenome interaction for human health is discussed, and we also indicate where future studies will be helpful to gain a deeper understanding of epigenetic effects elicited by selenium. PMID:25647085

  9. Recovery of adriamycin induced mitochondrial dysfunction in liver by selenium.

    PubMed

    Taskin, E; Dursun, N

    2015-12-01

    Adriamycin (ADR) is a chemotherapeutic drug. Its toxicities may associate with mitochondriopathy. Selenium (Se) is a trace element for essential intracellular antioxidant enzymes. However, there is lack of data related to the effect of selenium on the liver tissue of ADR-induced mitochondrial dysfunction. The study was to investigate whether Se could restore mitochondrial dysfunction of liver-exposed ADR. Rats were divided into four groups as a control, ADR, Se, co-treated ADR with Se groups. The biochemical measurements of the liver were made in mitochondrial and cytosol. ATP level and mitochondria membrane potential (MMP) were measured. Total oxidant (TOS), total antioxidant (TAS) status were determined and oxidative stress index (OSI) was calculated by using TOS and TAS. ADR increased TOS in mitochondria and also oxidative stress in mitochondria. ADR sligtly decreased MMP, and ATP level. Partial recovery of MMP by Se was able to elevate the ATP production in cotreatment of ADR with Se. TOS in mitochondria and cytosol was diminished, as well as OSI. We concluded that selenium could potentially be used against oxidative stress induced by ADR in liver, resulting from the restoration of MMP and ATP production and prevention of mitochondrial damage in vivo. PMID:25322894

  10. The synthesis of elemental selenium particles by Synechococcus leopoliensis.

    PubMed

    Hnain, Antoine; Brooks, Jordan; Lefebvre, Daniel D

    2013-12-01

    Exposure of Synechococcus leopoliensis to selenite in the light resulted in orange-colored granules associated with the cells. No such particles were made in dark grown cells or when selenite was replaced by selenate. Light and scanning electron microscopy revealed that the particles formed inside the cells. Furthermore, these were easily extracted and shown to be composed of selenium as determined by energy-dispersive X-ray spectroscopy. During selenium particle synthesis there was a concurrent loss of organic pigments in the cyanobacteria. Cells also become heavier as they produced and accumulated particles which were on average 220 nm in diameter and generally spherical in shape. The decline in selenite concentration in the culture media can be accounted for by the formation of cellular elemental selenium (Se(0)) during particle formation, although synthesis of small amounts of other Se compounds cannot be entirely discounted. Photosynthetic activity is required for the formation of Se(0), implicating the involvement of thylakoids. It is possible that an intimate association between the nascent particles and the thylakoids occurred. However, Se(0) granule formation did not occur peripherally between the thylakoid and the cytoplasmic membranes, but inside the thylakoid bands towards the center of the cells. It then appears that the particles are mobilized to the periphery and expelled from the cells, causing irreparable damage to the cell walls. PMID:24146080

  11. Cytotoxicity and therapeutic effect of irinotecan combined with selenium nanoparticles.

    PubMed

    Gao, Fuping; Yuan, Qing; Gao, Liang; Cai, Pengju; Zhu, Huarui; Liu, Ru; Wang, Yaling; Wei, Yueteng; Huang, Guodong; Liang, Jian; Gao, Xueyun

    2014-10-01

    Although chemotherapeutic drugs are widely applied for clinic tumor treatment, severe toxicity restricts their therapeutic efficacy. In this study, we reported a new form of selenium, selenium nanoparticles (Nano Se) which have significant lower toxicity and acceptable bioavailability. We investigated Nano Se as chemotherapy preventive agent to protect against toxicities of anticancer drug irinotecan and synergistically enhance the anti-tumor treatment effect in vitro and in vivo. The underlying mechanisms were also investigated. The combination of Nano Se and irinotecan showed increased cytotoxic effect with HCT-8 tumor cells likely by p53 mediated apoptosis. Nano Se inhibited growth of HCT-8 tumor cells partially through caspases mediated apoptosis. In vivo experiment showed Nano Se at a dose of 4 mg/kg/day significantly alleviated adverse effects induced by irinotecan (60 mg/kg) treatment. Nano Se alone treatment did not induce any toxic manifestations. The combination of Nano Se and irinotecan dramatically inhibited tumor growth and significantly induced apoptosis of tumor cells in HCT-8 cells xenografted tumor. Tumor inhibition rate was about 17.2%, 48.6% and 62.1% for Nano Se, irinotecan and the combination of Nano Se and irinotecan, respectively. The beneficial effects of Nano Se for tumor therapy were mainly ascribed to selectively regulating Nrf2-ARE (antioxidant responsive elements) pathway in tumor tissues and normal tissues. Our results suggest Nano Se is a promising selenium species with potential application in cancer treatment. PMID:25064805

  12. Removal of Selenium and Nitrate in Groundwater Using Organic Carbon-Based Reactive Mixtures

    NASA Astrophysics Data System (ADS)

    An, Hyeonsil; Jeen, Sung-Wook

    2016-04-01

    Treatment of selenium and nitrate in groundwater was evaluated through column experiments. Four columns consisting of reactive mixtures, either organic carbon-limestone (OC-LS) or organic carbon-zero valent iron (OC-ZVI), were used to determine the removal efficiency of selenium with different concentrations of nitrate. The source waters were collected from a mine site in Korea or were prepared artificially based on the mine drainage water or deionized water, followed by spiking of elevated concentrations of Se (40 mg/L) and nitrate (100 or 10 mg/L as NO3-N). The results for the aqueous chemistry showed that selenium and nitrate were effectively removed both in the mine drainage water and deionized water-based artificial input solution. However, the removal of selenium was delayed when selenium and nitrate coexisted in the OC-LS columns. The removal of selenium was not significant when the influent nitrate concentration was 100 mg/L as NO3-N, while most of nitrate was gradually removed within the columns. In contrast, 94% of selenium was removed when the influent nitrate concentration was reduced to 10 mg/L as NO3-N. In the OC-ZVI column, selenium and nitrate was removed almost simultaneously and completely even with the high nitrate concentration; however, a high concentration of ammonia was produced as a by-product of abiotic reaction between ZVI and nitrate. The elemental analysis for the solid samples after the termination of the experiments showed that selenium was accumulated in the reactive materials where removal of aqueous-phase selenium mostly occurred. The X-ray absorption near-edge structure (XANES) study indicated that selenium existed in the forms of SeS2 and Se(0) in the OC-LS column, while selenium was present in the forms of FeSe, SeS2 and absorbed Se(IV) in the OC-ZVI column. This study shows that OC-based reactive mixtures have an ability to remove selenium and nitrate in groundwater. However, the removal of selenium was influenced by the high

  13. A new class of lithium and sodium rechargeable batteries based on selenium and selenium-sulfur as a positive electrode.

    PubMed

    Abouimrane, Ali; Dambournet, Damien; Chapman, Karena W; Chupas, Peter J; Weng, Wei; Amine, Khalil

    2012-03-14

    A new class of selenium and selenium-sulfur (Se(x)S(y))-based cathode materials for room temperature lithium and sodium batteries is reported. The structural mechanisms for Li/Na insertion in these electrodes were investigated using pair distribution function (PDF) analysis. Not only does the Se electrode show promising electrochemical performance with both Li and Na anodes, but the additional potential for mixed Se(x)S(y) systems allows for tunable electrodes, combining the high capacities of S-rich systems with the high electrical conductivity of the d-electron containing Se. Unlike the widely studied Li/S system, both Se and Se(x)S(y) can be cycled to high voltages (up to 4.6 V) without failure. Their high densities and voltage output offer greater volumetric energy densities than S-based batteries, opening possibilities for new energy storage systems that can enable electric vehicles and smart grids. PMID:22364225

  14. Mobilization of selenium from the Mancos Shale and associated soils in the lower Uncompahgre River Basin, Colorado

    USGS Publications Warehouse

    Mast, M. Alisa; Mills, Taylor J.; Paschke, Suzanne S.; Keith, Gabrielle; Linard, Joshua I.

    2014-01-01

    This study investigates processes controlling mobilization of selenium in the lower part of the Uncompahgre River Basin in western Colorado. Selenium occurs naturally in the underlying Mancos Shale and is leached to groundwater and surface water by limited natural runoff, agricultural and domestic irrigation, and leakage from irrigation canals. Soil and sediment samples from the study area were tested using sequential extractions to identify the forms of selenium present in solid phases. Selenium speciation was characterized for nonirrigated and irrigated soils from an agricultural site and sediments from a wetland formed by a leaking canal. In nonirrigated areas, selenium was present in highly soluble sodium salts and gypsum. In irrigated soils, soluble forms of selenium were depleted and most selenium was associated with organic matter that was stable under near-surface weathering conditions. Laboratory leaching experiments and geochemical modeling confirm that selenium primarily is released to groundwater and surface water by dissolution of highly soluble selenium-bearing salts and gypsum present in soils and bedrock. Rates of selenium dissolution determined from column leachate experiments indicate that selenium is released most rapidly when water is applied to previously nonirrigated soils and sediment. High concentrations of extractable nitrate also were found in nonirrigated soils and bedrock that appear to be partially derived from weathered organic matter from the shale rather than from agricultural sources. Once selenium is mobilized, dissolved nitrate derived from natural sources appears to inhibit the reduction of dissolved selenium leading to elevated concentrations of selenium in groundwater. A conceptual model of selenium weathering is presented and used to explain seasonal variations in the surface-water chemistry of Loutzenhizer Arroyo, a major tributary contributor of selenium to the lower Uncompahgre River.

  15. Investigating the intra-individual variability in the human metabolic profile of urinary selenium.

    PubMed

    Lajin, Bassam; Kuehnelt, Doris; Jensen, Kenneth B; Francesconi, Kevin A

    2016-09-01

    Selenium is an essential micronutrient widely present in our diet. It plays its role through the selenoproteins. Previous reports have shown marked variation between individuals in the excretion of this trace element, but the intra-individual variability in selenium excretion has not been specifically investigated. The present study investigates the intra-individual variation in the urinary excretion of selenium in a group of healthy volunteers. We also discuss inter-individual variability trends. Urine samples were collected from healthy volunteers without selenium supplementation twice a day for 7 days and then once a week for an additional 7 weeks. A total of 168 urine samples were collected and analyzed for total selenium and individual selenium species using elemental mass spectrometry and HPLC/mass spectrometry, respectively. We found only modest day-to-day and week-to-week intra-individual variation of selenium excretion. Two commonly reported urine metabolites, selenosugar 1 and selenosugar 3, were detected in all urine samples, and our data suggest that selenosugar 3 is a deacetylated product of selenosugar 1 produced in a manner dependent on selenium intake. Trimethylselenonium displayed no intra-individual variability but considerable inter-individual variability in agreement with the involvement of genetic polymorphisms, as recently reported. Se-methylselenoneine was consistently detected in the urine of all volunteers and was a significant metabolite in one volunteer contributing up to 24% of total urinary selenium. Our data indicate that selenium urinary excretion is consistent within an individual, and that intra-individual variation in selenium excretion is unlikely to complicate future inter-individual variation studies. PMID:27473829

  16. Effects of piping irrigation laterals on selenium and salt loads, Montrose Arroyo Basin, western Colorado

    USGS Publications Warehouse

    Butler, D.L.

    2001-01-01

    Selenium and salinity are water-quality issues in the Upper Colorado River Basin. Certain water bodies in the lower Gunnison River Basin, including the lower Gunnison River and the Uncompahgre River, exceed the State standard for selenium of 5 micrograms per liter. Remediation methods to reduce selenium and salt loading in the lower Gunnison River Basin were examined. A demonstration project in Montrose Arroyo, located in the Uncompahgre River Basin near Montrose, was done during 1998-2000 to determine the effects on selenium and salt loads in Montrose Arroyo from replacing 8.5 miles of open-ditch irrigation laterals with 7.5 miles of pipe. The participants in the project were the National Irrigation Water Quality Program, the Colorado River Basin Salinity Control Program, the Uncompahgre Valley Water Users Association, and the U.S. Geological Survey. The placing of five laterals in pipe significantly decreased selenium loads in Montrose Arroyo. The selenium load at the outflow monitoring site was about 194 pounds per year less (28-percent decrease) in the period after the laterals were placed in pipe. More than 90 percent of the decrease in selenium load was attributed to a decrease in ground-water load. Salt loads also decreased because of the lateral project, but by a smaller percentage than the selenium loads. The salt load at the outflow site on Montrose Arroyo was about 1,980 tons per year less in the post-project period than in the pre-project period. All of the effects of the demonstration project on selenium and salt loads probably were not measured by this study because some of the lateral leakage that was eliminated had not necessarily discharged to Montrose Arroyo upstream from the monitoring sites. A greater decrease in selenium loads relative to salt loads may have been partially the result of decreases in selenium concentrations in ground water in some areas.

  17. Influence of domestic processing on the bioaccessibility of selenium from selected food grains and composite meals.

    PubMed

    Khanam, Anjum; Platel, Kalpana

    2016-03-01

    Selenium, an ultra trace element with several health beneficial attributes, should be mainly derived from dietary sources. Since food processing is likely to alter the bioavailability of micronutrients, the influence of such processing such as germination and fermentation on selenium content and bioaccessibility, information on which is lacking, was examined in this study. Bioaccessibility of selenium from four cereal-based composite meals was also studied. Chickpea, green gram and finger millet were employed to study the effect of germination, and for effect of fermentation, batters used in preparation dosa, idli and dhokla were used. Soaking the grains in water as a part of germination and fermentation brought about a decrease in selenium content, while its bioaccessibility was not affected. The information on the loss of selenium during soaking and heat processing of the germinated grains is novel. Fermentation resulted in a further decrease in selenium content, the percent decrease ranging from 26 to 47 in the batters. Similar decreases were seen in the bioaccessible selenium content as a result of soaking and fermentation. Cooking of the fermented batters, however, significantly enhanced the bioaccessibility of selenium from dosa and dhokla by 44 and 71 %, respectively. Selenium content of the four meals ranged from 150 to 228.8 ng/g. Bioaccessible selenium was highest in the finger millet-based meal (32.8 ng/g), followed by sorghum, wheat and rice-based meals. The present investigation thus provides vital and novel information on selenium content and bioaccessibility from foods subjected to processing as is commonly practiced in Indian households. PMID:27570288

  18. Selenium deficiency abrogates inflammation-dependent plasma cell tumors in mice.

    PubMed

    Felix, Klaus; Gerstmeier, Simone; Kyriakopoulos, Antonios; Howard, O M Zack; Dong, Hui-Fang; Eckhaus, Michael; Behne, Dietrich; Bornkamm, Georg W; Janz, Siegfried

    2004-04-15

    The role of the micronutrient, selenium, in human cancers associated with chronic inflammations and persistent infections is poorly understood. Peritoneal plasmacytomas (PCTs) in strain BALB/c (C), the premier experimental model of inflammation-dependent plasma cell transformation in mice, may afford an opportunity to gain additional insights into the significance of selenium in neoplastic development. Here, we report that selenium-depleted C mice (n = 32) maintained on a torula-based low-selenium diet (5-8 micro g of selenium/kg) were totally refractory to pristane induction of PCT. In contrast, 11 of 26 (42.3%) control mice maintained on a selenium adequate torula diet (300 micro g of selenium/kg) and 15 of 40 (37.5%) control mice fed standard Purina chow (440 micro g of selenium/kg) developed PCT by 275 days postpristane. Abrogation of PCT was caused in part by the striking inhibition of the formation of the inflammatory tissue in which PCT develop (pristane granuloma). This was associated with the reduced responsiveness of selenium-deficient inflammatory cells (monocytes and neutrophils) to chemoattractants, such as thioredoxin and chemokines. Selenium-deficient C mice exhibited little evidence of disturbed redox homeostasis and increased mutant frequency of a transgenic lacZ reporter gene in vivo. These findings implicate selenium, via the selenoproteins, in the promotion of inflammation-induced PCT and suggest that small drug inhibitors of selenoproteins might be useful for preventing human cancers linked with chronic inflammations and persistent infections. PMID:15087411

  19. Selenium exposure and depressive symptoms: the Coronary Artery Risk Development in Young Adults Trace Element Study

    PubMed Central

    Colangelo, Laura A; He, Ka; Whooley, Mary A; Daviglus, Martha L.; Morris, Steven; Liu, Kiang

    2014-01-01

    Selenium is an essential trace element important to neurotransmission, but toxic at high levels. Some studies suggest beneficial effects on mood. We assessed the association of selenium exposure with presence of depressive symptoms. Selenium exposure was measured in toenail samples collected in 1987 from 3,735 US participants (age 20–32 years) and depressive symptoms assessed in 1990, 1995, 2000, 2005, and 2010 using the Center for Epidemiologic Studies Depression Scale (CES-D). Binary and polytomous logistic regression models were used to assess the relation of log2(selenium) and selenium quintiles with presence of depressive symptoms (CES-D score ≥ 27 or on antidepressant medication). Relative to selenium quintile 1, the adjusted odds ratio (OR) for having depressive symptoms in 1990 for quintile 5 was 1.59 (95% CI: 1.01, 2.51) and a unit increase in log2(selenium), which represents a doubling of the selenium level, was associated with an OR=2.03 (95% CI: 1.12, 3.70). When examining 1, 2 or 3+ exams vs no exams with symptoms, the OR for quintile 5 was 1.73 (1.04, 2.89) for 3+ exams and for one exam and two exams, there were no associations. In a generalized estimating equations longitudinal model, a doubling of the selenium level was associated with a 56% higher odds of having depressive symptoms at an exam. Contrary to previously reported findings related to mood, higher level of selenium exposure was associated with presence of elevated depressive symptoms. More research is needed to elucidate the role of selenium in depressive disorders. PMID:24560993

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

    SciTech Connect

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

    1991-12-01

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

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

    PubMed

    Wu, L; Huang, Z Z

    1991-12-01

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

  2. 78 FR 22442 - Infant Formula: The Addition of Minimum and Maximum Levels of Selenium to Infant Formula and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-16

    ... biological functions of selenium include defense against oxidative stress, regulation of thyroid hormone action, and regulation of the oxidation/reduction status of vitamin C and other molecules. Plant foods... nuts. The selenium content of a food depends on the selenium content of the soil where the plant...

  3. Production of Submicron-Sized Elemental Selenium Spheres by Anaerobic Bacteria that Respire Oxyanions of Selenium

    NASA Astrophysics Data System (ADS)

    Oremland, R. S.; Herbel, M. J.; Switzer Blum, J.; Oscarson, R.

    2002-12-01

    Since the phenomenon of dissimilatory selenate reduction (DSeR) was first reported in (Macy et al., 1989; Oremland et al., 1989) at least 13 phylogenetically and physiologically diverse species of prokaryotes have been isolated from both the Bacterial and Archaeal domains that are capable of growth via DSeR. These microbes link the oxidation of various electron donors (e.g, lactate, acetate, hydrogen) to the terminal electron acceptors selenate, or in some cases selenite. The reduction product is amorphous, elemental selenium [Se(0)] that accumulates in large quantities in the medium as a bright orange-red precipitate. It was not clear to us how this precipitate was first formed on the cell surface. We first noted the accumulation of sub-micron sized spheres of Se(0) on the surface of Bacillus selenitireducens (Switzer Blum et al., 1998) grown on selenite. Here we report that this phenomenon occurs in at least 3 other species, including another haloalkaliphile B. arsenicoselenatis, the moderate halophile Selenihalanaerobacter shriftii, and the fresh water isolate Sulfurosprillum barnseii. Cell suspensions of all four species examined by scanning electron microscopy were noted to form spheres of Se(0) on their surfaces that sometimes accumulated in clusters. In general, the diameter of these spheres uniformly ranged in size between 100 - 200 nm. These results imply that most, if not all species of prokaryotes that respire via DSeR form these spheres. Although Se(0) spheres have not been as yet looked for as in anoxic sediments via imaging techniques, we would predict that they occur therein. Moreover, the emerging field of nanotechnology could find some application for uniformly-sized spheres of these dimensions because Se(0) is both a semiconductor and photoconductor. Macy et al. 1989, FEMS Microbiol. Lett. 61: 195 - 198. Oremland et al., 1989. Appl. Environ. Microbiol. 55: 2333 - 2343. Switzer Blum et al., 1998. Arch. Microbiol. 171: 19 - 30.

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

    SciTech Connect

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

    1995-12-01

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

  5. Analysis of Sulfur And Selenium Assimilation in 'Astragalus' Plants With Varying Capacities to Accumulate Selenium

    SciTech Connect

    Sors, T.G.; Ellis, D.R.; Na, G.Nam.; Lahner, B.; Lee, S.; Leustek, T.; Pickering, I.J.; Salt, D.E.; /Purdue U. /Rutgers U., Piscataway /Saskatchewan U.

    2007-08-08

    Several Astragalus species have the ability to hyperaccumulate selenium (Se) when growing in their native habitat. Given that the biochemical properties of Se parallel those of sulfur (S), we examined the activity of key S assimilatory enzymes ATP sulfurylase (ATPS), APS reductase (APR), and serine acetyltransferase (SAT), as well as selenocysteine methyltransferase (SMT), in eight Astragalus species with varying abilities to accumulate Se. Se hyperaccumulation was found to positively correlate with shoot accumulation of S-methylcysteine (MeCys) and Se-methylselenocysteine (MeSeCys), in addition to the level of SMT enzymatic activity. However, no correlation was observed between Se hyperaccumulation and ATPS, APR, and SAT activities in shoot tissue. Transgenic Arabidopsis thaliana overexpressing both ATPS and APR had a significant enhancement of selenate reduction as a proportion of total Se, whereas SAT overexpression resulted in only a slight increase in selenate reduction to organic forms. In general, total Se accumulation in shoots was lower in the transgenic plants overexpressing ATPS, PaAPR, and SAT. Root growth was adversely affected by selenate treatment in both ATPS and SAT overexpressors and less so in the PaAPR transgenic plants. Such observations support our conclusions that ATPS and APR are major contributors of selenate reduction in planta. However, Se hyperaccumulation in Astragalus is not driven by an overall increase in the capacity of these enzymes, but rather by either an increased Se flux through the S assimilatory pathway, generated by the biosynthesis of the sink metabolites MeCys or MeSeCys, or through an as yet unidentified Se assimilation pathway.

  6. Light dependence of selenium uptake by phytoplankton and implications for predicting selenium incorporation into food webs

    USGS Publications Warehouse

    Baines, S.B.; Fisher, N.S.; Doblin, M.A.; Cutter, G.A.; Cutter, L.S.; Cole, B.

    2004-01-01

    The potentially toxic element selenium is first concentrated from solution to a large but highly variable degree by algae and bacteria before being passed on to consumers. The large loads of abiotic and detrital suspended particles often present in rivers and estuaries may obscure spatial and temporal patterns in Se concentrations at the base of the food web. We used radiotracers to estimate uptake of both selenite (Se(IV)) and C by intact plankton communities at two sites in the Sacramento/San Joaquin River Delta. Our goals were to determine (1) whether C and Se(IV) uptake were coupled, (2) the role of bacteria in Se(IV) uptake, and (3) the Se:C uptake ratio of newly produced organic material. Se(IV) uptake, like C uptake, was strongly related to irradiance. The shapes of both relationships were very similar except that at least 42-56% of Se(IV) uptake occurred in the dark, whereas C uptake in the dark was negligible. Of this dark Se(IV) uptake, 34-67% occurred in the 0.2-1.0-??m size fraction, indicating significant uptake by bacteria. In addition to dark uptake, total Se(IV) uptake consisted of a light-driven component that was in fixed proportion to C uptake. Our estimates of daily areal Se(IV):C uptake ratios agreed very well with particulate Se:C measured at a site dominated by phytoplankton biomass. Estimates of bacterial Se:C were 2.4-13 times higher than for the phytoplankton, suggesting that bacteriovores may be exposed to higher dietary Se concentrations than herbivores.

  7. The use of the percentile method for searching empirical relationships between compression strength (UCS), Point Load (Is50) and Schmidt Hammer (RL) Indices

    NASA Astrophysics Data System (ADS)

    Bruno, Giovanni; Bobbo, Luigi; Vessia, Giovanna

    2014-05-01

    Is50 and RL indices are commonly used to indirectly estimate the compression strength of a rocky deposit by in situ and in laboratory devices. The widespread use of Point load and Schmidt hammer tests is due to the simplicity and the speediness of the execution of these tests. Their indices can be related to the UCS by means of the ordinary least square regression analyses. Several researchers suggest to take into account the lithology to build high correlated empirical expressions (R2 >0.8) to draw UCS from Is50 or RL values. Nevertheless, the lower and upper bounds of the UCS ranges of values that can be estimated by means of the two indirect indices are not clearly defined yet. Aydin (2009) stated that the Schmidt hammer test shall be used to assess the compression resistance of rocks characterized by UCS>12-20 MPa. On the other hand, the Point load measures can be performed on weak rocks but upper bound values for UCS are not suggested. In this paper, the empirical relationships between UCS, RL and Is50 are searched by means of the percentile method (Bruno et al. 2013). This method is based on looking for the best regression function, between measured data of UCS and one of the indirect indices, drawn from a subset sample of the couples of measures that are the percentile values. These values are taken from the original dataset of both measures by calculating the cumulative function. No hypothesis on the probability distribution of the sample is needed and the procedure shows to be robust with respect to odd values or outliers. In this study, the carbonate sedimentary rocks are investigated. According to the rock mass classification of Dobereiner and De Freitas (1986), the UCS values for the studied rocks range between 'extremely weak' to 'strong'. For the analyzed data, UCS varies between 1,18-270,70 MPa. Thus, through the percentile method the best empirical relationships UCS-Is50 and UCS-RL are plotted. Relationships between Is50 and RL are drawn, too

  8. Selenium homeostasis and antioxidant selenoproteins in brain: implications for disorders in the central nervous system.

    PubMed

    Steinbrenner, Holger; Sies, Helmut

    2013-08-15

    The essential trace element selenium, as selenocysteine, is incorporated into antioxidant selenoproteins such as glutathione peroxidases (GPx), thioredoxin reductases (TrxR) and selenoprotein P (Sepp1). Although comparatively low in selenium content, the brain exhibits high priority for selenium supply and retention under conditions of dietary selenium deficiency. Liver-derived Sepp1 is the major transport protein in plasma to supply the brain with selenium, serving as a "survival factor" for neurons in culture. Sepp1 expression has also been detected within the brain. Presumably, astrocytes secrete Sepp1, which is subsequently taken up by neurons via the apolipoprotein E receptor 2 (ApoER2). Knock-out of Sepp1 or ApoER2 as well as neuron-specific ablation of selenoprotein biosynthesis results in neurological dysfunction in mice. Astrocytes, generally less vulnerable to oxidative stress than neurons, are capable of up-regulating the expression of antioxidant selenoproteins upon brain injury. Occurrence of neurological disorders has been reported occasionally in patients with inadequate nutritional selenium supply or a mutation in the gene encoding selenocysteine synthase, one of the enzymes involved in selenoprotein biosynthesis. In three large trials carried out among elderly persons, a low selenium status was associated with faster decline in cognitive functions and poor performance in tests assessing coordination and motor speed. Future research is required to better understand the role of selenium and selenoproteins in brain diseases including hepatic encephalopathy. PMID:23500141

  9. Surveying selenium speciation from soil to cell—forms and transformations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this review was to present and evaluate the present knowledge on which selenium species are available to the general population in form of food and common supplements and how these species are metabolized in mammals. The overview of the selenium sources is taking a horizontal approach, w...

  10. Seed Priming with Selenium: Consequences for Emergence, Seedling Growth, and Biochemical Attributes of Rice.

    PubMed

    Khaliq, Abdul; Aslam, Farhena; Matloob, Amar; Hussain, Saddam; Geng, Mingjian; Wahid, Abdul; ur Rehman, Hafeez

    2015-08-01

    The present study was undertaken to appraise the role of selenium priming for improving emergence and seedling growth of basmati rice. Seeds of two fine rice cultivars (Super and Shaheen Basmati) were primed with concentrations of 15, 30, 45, 60, 75, 90, and 105 μmol L(-1) selenium. Untreated dry- and hydro-primed seeds were maintained as the control and positive control, respectively. Selenium priming resulted in early commencement of emergence, triggered seedling growth irrespective of rice cultivar over untreated control, and was more effective than hydro-priming except at higher concentrations. Lower electrical conductivity of seed leachates, reduced lipid peroxidation, greater α-amylase activity, higher soluble sugars, and enhanced activities of enzymatic antioxidants (superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and glutathione peroxidase (GPX)) were observed in seeds primed with selenium. Rice seedlings derived from selenium-primed seeds exhibited more chlorophyll contents, while total phenolics were comparable with those of the control seedlings. The improved starch metabolism, greater membrane stability, and increased activity of antioxidants were considered as possible mechanisms responsible for such improvements in emergence and seedling vigor of rice mediated by selenium priming. Priming with selenium (15-60 μmol L(-1)) favored rice emergence and seedling growth. Nevertheless, soaking seeds in relatively concentrated (90 and 105 μmol L(-1)) selenium solution had overall detrimental effects. PMID:25690516

  11. Recycling of high purity selenium from CIGS solar cell waste materials.

    PubMed

    Gustafsson, Anna M K; Foreman, Mark R StJ; Ekberg, Christian

    2014-10-01

    Copper indium gallium diselenide (CIGS) is a promising material in thin film solar cell production. To make CIGS solar cells more competitive, both economically and environmentally, in comparison to other energy sources, methods for recycling are needed. In addition to the generally high price of the material, significant amounts of the metals are lost in the manufacturing process. The feasibility of recycling selenium from CIGS through oxidation at elevated temperatures was therefore examined. During oxidation gaseous selenium dioxide was formed and could be separated from the other elements, which remained in solid state. Upon cooling, the selenium dioxide sublimes and can be collected as crystals. After oxidation for 1h at 800°C all of the selenium was separated from the CIGS material. Two different reduction methods for reduction of the selenium dioxide to selenium were tested. In the first reduction method an organic molecule was used as the reducing agent in a Riley reaction. In the second reduction method sulphur dioxide gas was used. Both methods resulted in high purity selenium. This proves that the studied selenium separation method could be the first step in a recycling process aimed at the complete separation and recovery of high purity elements from CIGS. PMID:24472714

  12. An evaluation of selenium concentrations in water, sediment, invertebrates, and fish from the Solomon River Basin.

    PubMed

    May, Thomas W; Fairchild, James F; Petty, Jim D; Walther, Michael J; Lucero, Jeff; Delvaux, Mike; Manring, Jill; Armbruster, Mike

    2008-02-01

    The Solomon River Basin is located in north-central Kansas in an area underlain by marine geologic shales. Selenium is an indigenous constituent of these shales and is readily leached into the surrounding groundwater. Portions of the Basin are irrigated primarily through the pumping of selenium-contaminated groundwater from wells onto fields in agricultural production. Water, sediment, macroinvertebrates, and fish were collected from various sites in the Basin in 1998 and analyzed for selenium. Selenium concentrations were analyzed spatially and temporally and compared to reported selenium toxic effect thresholds for specific ecosystem components: water, sediments, food-chain organisms, and wholebody fish. A selenium aquatic hazard assessment for the Basin was determined based on protocol established by Lemly. Throughout the Basin, water, macroinvertebrate, and whole fish samples exceeded levels suspected of causing reproductive impairment in fish. Population structures of several fish species implied that successful reproduction was occurring; however, the influence of immigration of fish from low-selenium habitats could not be discounted. Site-specific fish reproduction studies are needed to determine the true impact of selenium on fishery resources in the Basin. PMID:17587192

  13. An Azospira oryzae (syn Dechlorosoma suillum) Strain the Reduces Selenate and Selenite to Elemental Red Selenium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A bacterium that reduces the soluble selenium oxyanions, selenate and selenite, to insoluble elemental red selenium (Se0) was isolated from a laboratory reactor developed to remove selenate from groundwater. Gene sequence alignment of the 16S rRNA allowed identification of the isolate as Azospira o...

  14. Matrix modification with silver for the electrothermal atomization of arsenic and selenium

    USGS Publications Warehouse

    Sanzolone, R.F.; Chao, T.T.

    1981-01-01

    Silver as a matrix modifier is shown to improve the carbon-rod atomization of both arsenic and selenium for atomic absorption spectrometry. Compared to nickel, the efficiency of silver is greater for arsenic and about the same for selenium. Silver fulfils two functions in its reaction, namely stabilization during the ashing stage and enhancement of absorbance in the final atomization. ?? 1981.

  15. Selenium Supplementation Does Not Improve Vascular Responsiveness in Healthy North American Men

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium is an essential trace element that is an integral part of many selenoproteins, such as glutathione peroxidase and thioredoxin reductase, which may be important in inflammation and cardiovascular disease. In animal studies, selenium deficiency is associated with cardiomyopathy and sudden dea...

  16. Selenium status in workers handling aromatic nitro-amino compounds in a chemical factory

    SciTech Connect

    Yoshida, M.; Sunaga, M.; Hara, I. )

    1990-09-01

    The selenium status of workers handling aromatic nitro-amino (ANA) compounds was evaluated by measurement of their blood and urinary selenium concentrations and blood glutathione peroxidase (GSH-Px) activities. Forty-seven healthy Japanese male workers (42.7 +/- 12.1 yr) handling ANA compounds routinely in a chemical factory were studied as exposed workers, and 107 nonindustrial healthy Japanese males (39.3 +/- 10.0 yr) in the same region served as a control group. Urinary diazoreaction-positive metabolites and methemoglobin, both of which have been used as indices of exposure to ANA compounds, were significantly elevated in the exposed workers. Both plasma and erythrocyte selenium in the exposed workers showed 20% lower values compared to the control group. GSH-Px activities in plasma and erythrocytes were also significantly decreased in the exposed workers, but urinary selenium excretions were similar between the two groups. Questionnaire information obtained from each subject regarding intake habits of selenium-rich foods (bread, eggs, meat, and fish) indicated that the average dietary selenium intake was similar for the control group and the exposed workers. These results indicate that (1) the workers handling ANA compounds were surely exposed to these chemicals; (2) their selenium status was lower than that of the nonindustrial controls; and (3) the low selenium status was not associated with any dietary factor.

  17. Pinto beans as a course of bioavailable selenium to support bone structure in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is an essential trace mineral for animals and humans. The deficiency of Se has been linked to increased oxidative stress with increased levels of reactive oxygen species (ROS). Oxidative stress and ROS have been shown to stimulate bone resorption and osteoclast activity. Selenium, a ch...

  18. Short communication: inhibiting biofilm formation on paper towels through the use of selenium nanoparticles coatings.

    PubMed

    Wang, Qi; Webster, Thomas J

    2013-01-01

    Bacterial infections are commonly found on paper towels and other paper products, leading to the potential spread of bacteria and consequent health concerns. The objective of this in vitro study was to introduce antibacterial properties to standard paper towel surfaces by coating them with selenium nanoparticles. Scanning electron microscopy was used to measure the size and distribution of the selenium coatings on the paper towels. Atomic force microscopy was used to measure the surface roughness of paper towels before and after they were coated with selenium nanoparticles. The amount of selenium precipitated on the paper towels was measured by atomic absorption spectroscopy. In vitro bacterial studies with Staphylococcus aureus were conducted to assess the effectiveness of the selenium coating at inhibiting bacterial growth. Results showed that the selenium nanoparticles coated on the paper towel surface were well distributed with semispherical geometries about 50 nm in diameter. Most importantly, the selenium nanoparticle-coated paper towels inhibited S. aureus growth by 90% after 24 and 72 hours compared with the uncoated paper towels. Thus, the study showed that nanoparticle selenium-coated paper towels may lead to an increased eradication of bacteria in a wider range of clinical environments and in the food industry, thus improving human health. PMID:23378762

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Occurrence of selenium-containing tRNAs in mouse leukemia cells.

    PubMed Central

    Ching, W M

    1984-01-01

    Selenium incorporation into the polynucleotide structures of tRNAs has been documented in several microorganisms. In the present study, selenium-containing species were isolated from bulk tRNA preparations from 75Se-labeled mouse leukemia cells. The major 75Se-labeled species was similar in size and exhibited the same sensitivity to ribonuclease as did Escherichia coli tRNAs. The chromatographic properties of the intact major selenium-containing tRNA species indicated it to be very hydrophobic in character. The selenium component that is unstable at neutral-to-alkaline pH but is relatively stable at acid pH is not an esterified selenoamino acid. HPLC analysis of enzymic digests of the major selenium-containing species detected selenium-containing hydrophobic products (probably selenonucleosides ). These properties strongly suggest that the selenium in the mouse leukemia-cell tRNAs is present in the form of a selenium-modified nucleoside. PMID:6587339