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Sample records for 85th percentile selenium

  1. 2014 annual summary of the lower Gunnison River Basin Selenium Management Program water-quality monitoring, Colorado

    USGS Publications Warehouse

    Henneberg, Mark F.

    2016-08-10

    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

  2. Selenium.

    PubMed

    Barceloux, D G

    1999-01-01

    The 4 natural oxidation states of selenium are elemental selenium (0), selenide (-2), selenite (+4), and selenate (+6). Inorganic selenate and selenite predominate in water whereas organic selenium compounds (selenomethionine, selenocysteine) are the major selenium species in cereal and in vegetables. The principal applications of selenium include the manufacture of ceramics, glass, photoelectric cells, pigments, rectifiers, semiconductors, and steel as well as use in photography, pharmaceutical production, and rubber vulcanizing. High concentrations of selenium in surface and in ground water usually occur in farm areas where irrigation water drains from soils with high selenium content (Kesterson Reservoir, California) or in lakes receiving condenser cooling water from coal-fired electric power plants (Belews Lake, North Carolina). For the general population, the primary pathway of exposure to selenium is food, followed by water and air. Both selenite and selenate possess substantial bioavailability. However, plants preferentially absorb selenates and convert them to organic compounds. Aquatic organisms (e.g., bivalves) can accumulate and magnify selenium in the food chain. Selenium is an essential component of glutathione peroxidase, which is an important enzyme for processes that protect lipids in polyunsaturated membranes from oxidative degradation. Inadequate concentrations of selenium in the Chinese diet account, at least in part, for the illness called Keshan disease. Selenium deficiency occurs in the geographic areas where Balkan nephropathy appears, but there is no direct evidence that selenium deficiency contributes to the development of this chronic, progressive kidney disease. Several lines of scientific inquiry suggest that an increased risk of cancer occurs as a result of low concentrations of selenium in the diet; however, insufficient evidence exists at the present time to recommend the use of selenium supplements for the prevention of cancer. The

  3. 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

  4. Flow-adjusted trends in dissolved selenium load and concentration in the Gunnison and Colorado Rivers near Grand Junction, Colorado, water years 1986--2008

    USGS Publications Warehouse

    Mayo, John W.; Leib, Kenneth J.

    2012-01-01

    in selenium loads and concentrations during the period of study are of primary interest to the cooperators. Selenium loads for each of the 2 water years were calculated by using normalized mean-daily streamflow, measured selenium concentration, standard linear regression techniques, and data previously collected at the two study sites. Mean-daily streamflow was normalized for each site by averaging the daily streamflow for each day of the year over the 23-year period of record. Thus, for the beginning and ending water years, estimations could be made of loads that would have occurred without the effect of year-to-year streamflow variation. The loads thus calculated are illustrative of the change in loads between water years 1986 and 2008, and are not the actual loads that occurred in those 2 water years. The estimated 50th and 85th percentile selenium concentrations associated with the selenium loads were also calculated for WY 1986 and WY 2008 at each site. Time-trends in selenium concentration at the two sites were charted by using regression techniques for partial residuals for the entire study period (WY 1986 through WY 2008). Annual selenium load for the Gunnison River site was estimated to be 23,196 pounds for WY 1986 and 16,560 pounds for WY 2008, a 28.6 percent decrease. Lower and upper 95-percent confidence levels for WY 1986 annual load were 22,360 and 24,032 pounds. Lower and upper 95-percent confidence levels for WY 2008 annual load were 15,724 and 17,396 pounds. Estimated 50th percentile daily selenium concentrations decreased from 6.41 to 4.57 micrograms/liter from WY 1986 to WY 2008, whereas estimated 85th percentile daily selenium concentrations decreased from 7.21 to 5.13 micrograms/liter from WY 1986 to WY 2008. Annual selenium load for the Colorado River site was estimated to be 56,587 pounds for WY 1986 and 34,344 pounds for WY 2008, a 39.3 percent decrease. Lower and upper 95-percent confidence levels for WY 1986 annual load were 53,785 and 59

  5. 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…

  6. 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 ...

  7. 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

  8. 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.

  9. Comparison of Updated Weight and Height Percentiles with Previous References in 6-17-Year-Old Children in Kayseri, Turkey

    PubMed Central

    Zararsız, Gökmen; Çiçek, Betül; Kondolot, Meda; Mazıcıoğlu, M. Mümtaz; Öztürk, Ahmet; Kurtoğlu, Selim

    2017-01-01

    Objective: To compare updated weight and height percentiles of 6-17-year-old children from all socio-economic levels in Kayseri with previous local references and other national/international data. Methods: The second study “Determination of Anthropometric Measurements of Turkish Children and Adolescents study (DAMTCA II)” was conducted in Kayseri, between October 2007 and April 2008. Weight and height measurements from 4321 (1926 boys, 2395 girls) school children aged between 6 to 17 years were included in this cross-sectional study. Using these data, weight and height percentile curves were produced with generalized additive models for location, scale and shape (GAMLSS) and compared with the most recent references. Results: Smoothed percentile curves including the 3rd, 5th, 10th, 15th, 25th, 50th, 75th, 85th, 90th, 95th, and 97th percentiles were obtained for boys and girls. These results were compared with DAMTCA I study and with two national (İstanbul and Ankara) and international data from Asia and from Europe. Conclusion: This study provides updated weight and height references for Turkish school children aged between 6 and 17 years residing in Kayseri. PMID:27507256

  10. Flux creep and irreversibility in electron-doped Pr 1.85Th 0.15CuO 4- y

    NASA Astrophysics Data System (ADS)

    Peng, J. L.; Greene, R. L.

    1990-12-01

    High-quality crystallites of Pr 1.85Th 0.15CuO 4- y were prepared by a solid state reaction technique and aligned in epoxy by a magnetic field. Magnetic relaxation of the remanent moment was measured with field H parallel to the ab plane. We interpret our data with a thermally activated flux creep model, and show that effective pinning energy U0 increases with increasing T between 2 and 15 K. We find that U0 is not strongly dependent on applied field. The crossover from reversible to irreversible magnetization was found to follow the power law H= H(0)(1- T/ Tc) 1.7. The value of U0 for H parallel to the ab plane is found to vary from ≈8 to ≈40 meV between 2 and 15 K, respectively. Compared to YBCO, pinning in the electron-doped system is rather weak.

  11. 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

  12. 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…

  13. Contrasting OLS and Quantile Regression Approaches to Student "Growth" Percentiles

    ERIC Educational Resources Information Center

    Castellano, Katherine Elizabeth; Ho, Andrew Dean

    2013-01-01

    Regression methods can locate student test scores in a conditional distribution, given past scores. This article contrasts and clarifies two approaches to describing these locations in terms of readily interpretable percentile ranks or "conditional status percentile ranks." The first is Betebenner's quantile regression approach that results in…

  14. Do genes modify the association of selenium and lipid levels?

    PubMed

    Galan-Chilet, Inmaculada; Guallar, Eliseo; Martin-Escudero, J Carlos; De Marco, Griselda; Dominguez-Lucas, Alejandro; Gonzalez-Manzano, Isabel; Lopez-Izquierdo, Raul; Redon, Josep; Chaves, F Javier; Tellez-Plaza, Maria

    2015-05-20

    The interaction of selenium, a component of antioxidant selenoproteins, with genetic variation in lipid-related pathways has not been evaluated earlier as a potential determinant of blood lipid levels. We aimed at evaluating the effects of gene-environment interactions between plasma levels of selenium and polymorphisms in lipid metabolic pathways on plasma lipid levels in a study population from Spain (N=1,315). We observed statistically significant associations between plasma selenium and lipid levels (differences in total, low-density lipoprotein [LDL]-cholesterol, and triglycerides comparing the 80th with the 20th percentiles of plasma selenium levels were, respectively, 12.0 (95% confidence interval 6.3, 17.8), 8.9 (3.7, 14.2), and 9.0 (2.9, 15.2) mg/dl). We also found statistically significant interactions at the Bonferroni-corrected significance level (p=0.0008) between selenium and rs2290201 in FABP4 for total and LDL cholesterol levels and rs1800774 in CETP for elevated LDL cholesterol. Other polymorphisms showed statistically significant differential associations of plasma selenium levels and lipids biomarkers at the nominal p-value of 0.05. Reported statistical interactions with genes involved in lipid transport and transfer provide biological support to the positive associations of selenium with lipids shown in cross-sectional studies and lead to the hypothesis that selenium and lipid levels share common biological pathways that need to be elucidated in mechanistic studies.

  15. Selenium species in selenium fortified dietary supplements.

    PubMed

    Niedzielski, Przemyslaw; Rudnicka, Monika; Wachelka, Marcin; Kozak, Lidia; Rzany, Magda; Wozniak, Magdalena; Kaskow, Zaneta

    2016-01-01

    This article presents a study of dietary supplements available on the Polish market. The supplements comprised a large group of products with selenium content declared by the producer. The study involved determination of dissolution time under different conditions and solubility as well as content and speciation of selenium. The total content was determined as well as organic selenium and the inorganic forms Se(IV) and Se(VI). The organic selenium content was calculated as the difference between total Se and inorganic Se. The values obtained were compared with producers' declarations. The work is the first such study of selenium supplements available on the market of an EU Member State.

  16. 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

  17. 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.

  18. [Selenium deficiency in pregnancy?].

    PubMed

    Lechner, W; Jenewein, I; Ritzberger, G; Sölder, E; Waitz-Penz, A; Schirmer, M; Abfalter, E

    1990-07-15

    Selenium content was investigated by atomic absorbtion spectroscopy in 32 normal pregnant women in the 38th-42, week of pregnancy. In congruence with other investigations from middle and northern Europe, selenium deficiency was stated in all of the patients.

  19. Selenium in diet

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002414.htm Selenium in diet To use the sharing features on this page, please enable JavaScript. Selenium is an essential trace mineral. This means your ...

  20. 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)

  1. 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)

  2. Selenium in bovine spermatozoa.

    PubMed

    Niemi, S M; Kuzan, F B; Senger, P L

    1981-05-01

    This study investigated the association of selenium with ejaculated bovine spermatozoa. Over 75% of the radioactive spermatozoa. Over 75% of the radioactive selenium-75 was released after 30 min of incubation in 2 X 10(-3) dithiothreitol. Of the selenium-75 released by dithiothreitol, 85% was associated with spermatozoal protein. Protein containing selenium-75 was found predominantly in a single band after polyacrylamide gel electrophoresis. Molecular weight was approximately 21,500 daltons.

  3. Anthropometry of height, weight, arm, wrist, abdominal circumference and body mass index, for Bolivian adolescents 12 to 18 years: Bolivian adolescent percentile values from the MESA study.

    PubMed

    Baya Botti, A; Pérez-Cueto, F J A; Vasquez Monllor, P A; Kolsteren, P W

    2009-01-01

    Anthropometry is important as clinical tool for individual follow-up as well as for planning and health policy-making at population level. Recent references of Bolivian Adolescents are not available. The aim of this cross sectional study was to provide age and sex specific centile values and charts of Body Mass Index, height, weight, arm, wrist and abdominal circumference from Bolivian Adolescents. Data from the MEtabolic Syndrome in Adolescents (MESA) study was used. Thirty-two Bolivian clusters from urban and rural areas were selected randomly considering population proportions, 3445 school going adolescents, 12 to 18 y, 45% males; 55% females underwent anthropometric evaluation by trained personnel using standardized protocols for all interviews and examinations. Weight, height, wrist, arm and abdominal circumference data were collected. Body Mass Index was calculated. Smoothed age- and gender specific 3rd, 5th, 10th, 25th, 50th, 75th, 85th, 90th, 95th and 97th Bolivian adolescent percentiles(BAP) and Charts(BAC) where derived using LMS regression. Percentile-based reference data for the antropometrics of for Bolivian Adolescents are presented for the first time.

  4. 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)

  5. 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…

  6. Selenium cytotoxicity in cancer.

    PubMed

    Wallenberg, Marita; Misra, Sougat; Björnstedt, Mikael

    2014-05-01

    Selenium is an essential trace element with growth-modulating properties. Decades of research clearly demonstrate that selenium compounds inhibit the growth of malignant cells in diverse experimental model systems. However, the growth-modulating and cytotoxic mechanisms are diverse and far from clear. Lately, a remarkable tumour selective cytotoxicity of selenium compounds has been shown, indicating the potential of selenium in the treatment of cancer. Of particular interest are the redox-active selenium compounds exhibiting cytotoxic potential to tumour cells. These selenium compounds elicit complex patterns of pharmacodynamics and pharmacokinetics, leading to cell death pathways that differ among compounds. Modern oncology often focuses on targeted ligand-based therapeutic strategies that are specific to their molecular targets. These drugs are initially efficient, but the tumour cells often rapidly develop resistance against these drugs. In contrast, certain redox-active selenium compounds induce complex cascades of pro-death signalling at pharmacological concentrations with superior tumour specificity. The target molecules are often the ones that are important for the survival of cancer cells and often implicated in drug resistance. Therefore, the chemotherapeutic applications of selenium offer great possibilities of multi-target attacks on tumour cells. This MiniReview focuses on the tumour-specific cytotoxic effects of selenium, with special emphasis on cascades of cellular events induced by the major groups of pharmacologically active selenium compounds. Furthermore, the great pharmacological potential of selenium in the treatment of resistant cancers is discussed.

  7. Should we use customized fetal growth percentiles in urban Canada?

    PubMed

    Melamed, Nir; Ray, Joel G; Shah, Prakesh S; Berger, Howard; Kingdom, John C

    2014-02-01

    An increasingly common challenge in antenatal care of the small for gestational age (SGA) fetus is the distinction between the constitutionally (physiologically) small fetus and the fetus affected by pathological intrauterine growth restriction (IUGR). We discuss here the rationale and the evidence for the use of customized growth percentiles for the purpose of distinguishing between the fetus with true IUGR and the fetus with constitutional SGA. We also provide estimates of the potential effects of adopting ethnicity-specific birth weight curves on the rates of SGA and large for gestational age status in multi-ethnic metropolitan cities in North America and Europe, such as the City of Toronto. Using customized growth percentiles would result in a considerable decline in the rate of a false-positive diagnosis of SGA among visible minorities, and improve the detection rate of true large for gestational age fetuses among these groups.

  8. Biomonitoring Equivalents for selenium.

    PubMed

    Hays, Sean M; Macey, Kristin; Nong, Andy; Aylward, Lesa L

    2014-10-01

    Selenium is an essential nutrient for human health with a narrow range between essentiality and toxicity. Selenium is incorporated into several proteins that perform important functions in the body. With insufficient selenium intake, the most notable effect is Keshan disease, an endemic cardiomyopathy in children. Conversely, excessive selenium intake can result in selenosis, manifested as brittle nails and hair and gastro-intestinal disorders. As such, guidance values have been established to protect against both insufficient and excessive selenium exposures. Dietary Reference Intakes (DRIs) have been established as standard reference values for nutritional adequacy in North America. To protect against selenosis resulting from exposure to excessive amounts of selenium, several government and non-governmental agencies have established a range of guidance values. Exposure to selenium is primarily through the diet, but monitoring selenium intake is difficult. Biomonitoring is a useful means of assessing and monitoring selenium status for both insufficient and excessive exposures. However, to be able to interpret selenium biomonitoring data, levels associated with both DRIs and toxicity guidance values are required. Biomonitoring Equivalents (BEs) were developed for selenium in whole blood, plasma and urine. The BEs associated with assuring adequate selenium intake (Estimated Average Requirements - EAR) are 100, 80 and 10μg/L in whole blood, plasma and urine, respectively. The BEs associated with protection against selenosis range from 400 to 480μg/L in whole blood, 180-230μg/L in plasma, and 90-110μg/L in urine. These BE values can be used by both regulatory agencies and public health officials to interpret selenium biomonitoring data in a health risk context.

  9. Serum selenium and lipid levels: Associations observed in the National Health and Nutrition Examination Survey (NHANES) 2011-2012.

    PubMed

    Christensen, Krista; Werner, Mark; Malecki, Kristen

    2015-07-01

    Selenium is an essential micronutrient, and due to its antioxidant activity, is hypothesized to be beneficial to cardiovascular health. However, the evidence for an association between selenium and health markers such as lipid levels has been mixed. This may be due to substantial variability in the level of selenium intake between populations and potential non-linearity of selenium-health outcome associations. We used the 2011-2012 National Health and Nutrition Examination Survey (NHANES) to examine the relationship between serum selenium and lipid levels among participants aged 12 years and older. Associations were evaluated using both linear regression models, as well as ordinal logistic regression and quantile regression models to allow for potential non-linear relationships. In all models, potential confounders of sex, age group, race/ethnicity, educational attainment and cotinine were included. Overall, 40% of participants had total cholesterol levels classified as borderline or elevated, and total cholesterol increased with increasing selenium (p=0.01). A similar pattern was seen for triglycerides (p=0.02). LDL cholesterol was also associated with selenium but not in a linear fashion; HDL cholesterol did not vary with selenium. Multivariate quantile regression showed significant associations between selenium and total cholesterol, LDL cholesterol, and triglycerides. The effect of selenium was stronger with increasing quantile for total cholesterol and for triglycerides. In contrast, for LDL cholesterol the association was positive in the 10th and 50th percentiles, but (non-significant and) negative in the 90th percentile. These results show that while selenium may impact cardiovascular health via effects on lipid levels, the associations may not be linear.

  10. Selenium and human health.

    PubMed

    Rayman, Margaret P

    2012-03-31

    Selenium is incorporated into selenoproteins that have a wide range of pleiotropic effects, ranging from antioxidant and anti-inflammatory effects to the production of active thyroid hormone. In the past 10 years, the discovery of disease-associated polymorphisms in selenoprotein genes has drawn attention to the relevance of selenoproteins to health. Low selenium status has been associated with increased risk of mortality, poor immune function, and cognitive decline. Higher selenium status or selenium supplementation has antiviral effects, is essential for successful male and female reproduction, and reduces the risk of autoimmune thyroid disease. Prospective studies have generally shown some benefit of higher selenium status on the risk of prostate, lung, colorectal, and bladder cancers, but findings from trials have been mixed, which probably emphasises the fact that supplementation will confer benefit only if intake of a nutrient is inadequate. Supplementation of people who already have adequate intake with additional selenium might increase their risk of type-2 diabetes. The crucial factor that needs to be emphasised with regard to the health effects of selenium is the inextricable U-shaped link with status; whereas additional selenium intake may benefit people with low status, those with adequate-to-high status might be affected adversely and should not take selenium supplements.

  11. Mineral Commodity Profiles: Selenium

    USGS Publications Warehouse

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

    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.

  13. 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.

  14. 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.

  15. Evaluation of the growth percentiles of children with congenital heart disease.

    PubMed

    Martins da Silva, Viviane; de Oliveira Lopes, Marcos Venícios; Leite de Araujo, Thelma

    2007-01-01

    The purpose of this study was to evaluate the correlation between anthropometric measures of children with congenital heart disease with percentiles that represent their growth indicators. Anthropometric evaluations of 135 hospitalized children with congenital heart disease were performed in a hospital specialized in cardiac diseases in Fortaleza, CE, Brazil. For the growth evaluation, percentiles of height by age, weight by height and weight by age were calculated. Children's average age was 4.74 months (+ 3.78) and 66.7% of the children were male. The medians of the three percentiles presented values below percentile 10, indicating a high proportion of values considered of risk. The subscapular thickness presented positive correlation with the three percentiles. The values of percentiles studied indicated growth delay.

  16. Selenium and Prostate Cancer: Analysis of Individual Participant Data From Fifteen Prospective Studies

    PubMed Central

    Travis, Ruth C.; Appleby, Paul N.; Albanes, Demetrius; Barnett, Matt J.; Black, Amanda; Bueno-de-Mesquita, H. Bas; Deschasaux, Mélanie; Galan, Pilar; Goodman, Gary E.; Goodman, Phyllis J.; Gunter, Marc J.; Heliövaara, Markku; Helzlsouer, Kathy J.; Henderson, Brian E.; Hercberg, Serge; Knekt, Paul; Kolonel, Laurence N.; Lasheras, Christina; Linseisen, Jakob; Metter, E. Jeffrey; Neuhouser, Marian L.; Olsen, Anja; Pala, Valeria; Platz, Elizabeth A.; Rissanen, Harri; Reid, Mary E.; Schenk, Jeannette M.; Stampfer, Meir J.; Stattin, Pär; Tangen, Catherine M.; Touvier, Mathilde; Trichopoulou, Antonia; van den Brandt, Piet A.; Key, Timothy J.

    2016-01-01

    Background: Some observational studies suggest that a higher selenium status is associated with a lower risk of prostate cancer but have been generally too small to provide precise estimates of associations, particularly by disease stage and grade. Methods: Collaborating investigators from 15 prospective studies provided individual-participant records (from predominantly men of white European ancestry) on blood or toenail selenium concentrations and prostate cancer risk. Odds ratios of prostate cancer by selenium concentration were estimated using multivariable-adjusted conditional logistic regression. All statistical tests were two-sided. Results: Blood selenium was not associated with the risk of total prostate cancer (multivariable-adjusted odds ratio [OR] per 80 percentile increase = 1.01, 95% confidence interval [CI] = 0.83 to 1.23, based on 4527 case patients and 6021 control subjects). However, there was heterogeneity by disease aggressiveness (ie, advanced stage and/or prostate cancer death, Pheterogeneity = .01), with high blood selenium associated with a lower risk of aggressive disease (OR = 0.43, 95% CI = 0.21 to 0.87) but not with nonaggressive disease. Nail selenium was inversely associated with total prostate cancer (OR = 0.29, 95% CI = 0.22 to 0.40, Ptrend < .001, based on 1970 case patients and 2086 control subjects), including both nonaggressive (OR = 0.33, 95% CI = 0.22 to 0.50) and aggressive disease (OR = 0.18, 95% CI = 0.11 to 0.31, Pheterogeneity = .08). Conclusions: Nail, but not blood, selenium concentration is inversely associated with risk of total prostate cancer, possibly because nails are a more reliable marker of long-term selenium exposure. Both blood and nail selenium concentrations are associated with a reduced risk of aggressive disease, which warrants further investigation. PMID:27385803

  17. 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

  18. Wingate Anaerobic Test Percentile Norms in Colombian Healthy Adults.

    PubMed

    Ramírez-Vélez, Robinson; López-Albán, Carlos A; La Rotta-Villamizar, Diego R; Romero-García, Jesús A; Alonso-Martinez, Alicia M; Izquierdo, Mikel

    2016-01-01

    The Wingate Anaerobic Test (WAnT) became one of the most convenient tests used to evaluate anaerobic capacity and the effectiveness of anaerobic training programs for a variety of power sports. However, its use and interpretation as an evaluative measurement are limited because there are few published reference values derived from large numbers of subjects in nonathletic populations. We present reference values for the WAnT in Colombian healthy adults (aged 20-80 years old). The sample comprised 1,873 subjects (64% men) from Cali, Colombia, who were recruited for the study between 2002 and 2012. The 30-second WAnT was performed on a Monark ergometer. The WAnT resistance was set at 0.075 kp · kg(-1) body mass (BM). The mean absolute peak power (PP), relative PP normalized to the BM, and the fatigue index (FI%) were calculated using the LMS method (L [curve Box-Cox], M [curve median], and S [curve coefficient of variation]) and expressed as tabulated percentiles from 3 to 97 and as smoothed centile curves (P3, P10, P25, P50, P75, P90, P97). Mean ± SD values for the patients' anthropometric data were 38.1 ± 11.7 years of age, 72.7 ± 14.2 kg weight, 1.68 ± 0.09 m height, and 25.6 ± 4.2 body mass index. Our results show that mean absolute PP value, relative PP relative values normalized to BM, and FI were 527.4 ± 131.7 W, 7.6 ± 2.3 W · kg(-1), and 29.0 ± 15.7%, respectively. Men performed better than women in terms of PP and FI values. Nevertheless, the mean PP decreased with age and sex. Age-specific PP and FI normative values among healthy Colombian adults are defined. A more specific set of reference values is useful for clinicians and researchers studying anaerobic capacity in healthy adults.

  19. 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…

  20. Reproduction in mallards fed selenium

    USGS Publications Warehouse

    Heinz, G.H.; Hoffman, D.J.; Krynitsky, A.J.; Weller, D.M.G.

    1987-01-01

    Mallards (Anas platyrhynchos) were fed diets containing 1, 5, 10, 25 or 100 ppm selenium as sodium selenite, a diet containing 10 ppm selenium as seleno-DL-methionine or a control diet. There were no effects of 1, 5 or 10 ppm selenium as sodium selenite on either weight or survival of adults or on reproductive success, and there did not appear to be a dose-response relationship at these lower levels. The 100 ppm selenium diet killed 11 of 12 adults; one adult male fed 25 ppm selenium died. Selenium at 25 and 100 ppm caused weight loss in adults. Females fed 25 ppm selenium took longer to begin laying eggs and intervals between eggs were longer than in females in other treatment groups. Hatching success appeared to be reduced in birds fed 10 ppm selenium at selenomethionine, but the reduction was not statistically significant. The survival of ducklings and the mean number of 21-d-old ducklings produced per female were reduced in the 25 ppm selenium as sodium selenite group and the 10 ppm selenium as selenomethionine group. Egg weights were not affected by any selenium treatment, but 25 ppm selenium lowered the Ratcliffe Index. Duckling weights at hatching and at 21 d of age were reduced 28 and 36%, respectively, in birds fed 25 ppm selenium, as compared with controls. Body weights measured on day 21 were lower for ducklings fed 10 ppm selenium as selenomethionine than in some other groups. Selenium in concentrations of 10 and 25 ppm as sodium selenite caused mainly embryotoxic effects, whereas 10 ppm as selenomethionine was more teratogenic, causing hydrocephaly, bill defects, eye defects (microphthalmia and anophthalmia) and foot and toe defects, including ectrodactyly. Selenomethionine was much more readily taken up by mallards and passed into their eggs than was sodium selenite, and a greater proportion of the selenium in the eggs ended up in the white when selenomethionine was fed. Adult males accumulated more selenium than did females, probably because of the

  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. 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

  3. 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...

  4. 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.

  5. 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

  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. Bias and imprecision in posture percentile variables estimated from short exposure samples

    PubMed Central

    2012-01-01

    Background Upper arm postures are believed to be an important risk determinant for musculoskeletal disorder development in the neck and shoulders. The 10th and 90th percentiles of the angular elevation distribution have been reported in many studies as measures of neutral and extreme postural exposures, and variation has been quantified by the 10th-90th percentile range. Further, the 50th percentile is commonly reported as a measure of "average" exposure. These four variables have been estimated using samples of observed or directly measured postures, typically using sampling durations between 5 and 120 min. Methods The present study examined the statistical properties of estimated full-shift values of the 10th, 50th and 90th percentile and the 10th-90th percentile range of right upper arm elevation obtained from samples of seven different durations, ranging from 5 to 240 min. The sampling strategies were realized by simulation, using a parent data set of 73 full-shift, continuous inclinometer recordings among hairdressers. For each shift, sampling duration and exposure variable, the mean, standard deviation and sample dispersion limits (2.5% and 97.5%) of all possible sample estimates obtained at one minute intervals were calculated and compared to the true full-shift exposure value. Results Estimates of the 10th percentile proved to be upward biased with limited sampling, and those of the 90th percentile and the percentile range, downward biased. The 50th percentile was also slightly upwards biased. For all variables, bias was more severe with shorter sampling durations, and it correlated significantly with the true full-shift value for the 10th and 90th percentiles and the percentile range. As expected, shorter samples led to decreased precision of the estimate; sample standard deviations correlated strongly with true full-shift exposure values. Conclusions The documented risk of pronounced bias and low precision of percentile estimates obtained from short

  8. Selenium incorporation using recombinant techniques.

    PubMed

    Walden, Helen

    2010-04-01

    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.

  9. 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.

  10. Selenium in mammalian spermiogenesis.

    PubMed

    Flohé, Leopold

    2007-10-01

    The role of selenium in male fertility is reviewed with special emphasis on selenoprotein P and phospholipid hydroperoxide glutathione peroxidase (GPx4) in spermiogenesis. Inverse genetics reveal that selenoprotein P is required for selenium supply to the testis. GPx4 is abundantly synthesized in spermatids. As a moonlighting protein it is transformed in the later stages of spermiogenesis from an active selenoperoxidase into a structural protein that becomes a constituent of the mitochondrial sheath of spermatozoa. The transformation is paralleled by loss of glutathione. Mechanistically, the process is an alternate substrate inactivation of GPx4 resulting from reactions of its selenenic form with thiols of GPx4 itself and other proteins. Circumstantial evidence and ongoing experimental genetics indicate that the mitochondrially expressed form of the GPx4 gene is the most relevant one in spermiogenesis, with the nuclear form being dispensable for fertility and the role of cytosolic GPx4 remaining unclear. Clinical data reveal a strong association of low sperm GPx4 with infertility. Thus, impaired GPx4 biosynthesis, due to selenium deficiency or to genetic defects in gpx4 itself or in proteins involved in Se distribution and selenoprotein biosynthesis, causes male infertility, but can also be an epiphenomenon due to any perturbation of testicular function.

  11. Using weight-for-age percentiles to screen for overweight and obese children and adolescents.

    PubMed

    Gamliel, Adir; Ziv-Baran, Tomer; Siegel, Robert M; Fogelman, Yacov; Dubnov-Raz, Gal

    2015-12-01

    There are relatively low rates of screening for overweight and obesity among children and adolescents in primary care. A simplified method for such screening is needed. The study objective was to examine if weight-for-age percentiles are sufficiently sensitive in identifying overweight and obesity in children and adolescents. We used data from two distinct sources: four consecutive cycles of the National Health and Nutrition Examination Surveys (NHANES) from the years 2005 to 2012, using participants aged 2-17.9 years for whom data on age, sex, weight, and height were available (n=12,884), and primary care clinic measurements (n=15,152). Primary outcomes were the threshold values of weight-for-age percentiles which best discriminated between normal weight, overweight, and obesity status. Receiver operating characteristic analyses demonstrated that weight-for-age percentiles well discriminated between normal weight and overweight and between non-obese and obese individuals (area under curve=0.956 and 0.977, respectively, both p<0.001). Following Classification and Regression Trees analysis, the 90th and 75th weight-for-age percentiles were chosen as appropriate cutoffs for obesity and overweight, respectively. These cutoffs had high sensitivity and negative predictive value in identifying obese participants (94.3% and 98.6%, respectively, for the 90th percentile) and in identifying overweight participants (93.2% and 95.9%, respectively, for the 75th percentile). The sensitivities and specificities were nearly identical across race and sex, and in the validation data from NHANES 2011 to 2012 and primary care. We conclude that weight-for-age percentiles can discriminate between normal weight, overweight and obese children, and adolescents. The 75th and 90th weight-for-age percentiles correspond well with the BMI cutoffs for pediatric overweight and obesity, respectively.

  12. Selenium, Folate, and Colon Cancer

    PubMed Central

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

    2009-01-01

    Background Selenium is an essential trace element which has been implicated in cancer risk; however, study results have been inconsistent with regard to colon cancer. Our objectives were to 1) investigate the association between selenium and colon cancer 2) evaluate possible effect measure modifiers and 3) evaluate potential biases associated with the use of post-diagnostic serum selenium measures Methods The North Carolina Colon Cancer Study is a large population-based, case-control study of colon cancer in North Carolina between 1996 and 2000 (n=1,691). Nurses interviewed patients about diet and lifestyle and drew blood specimens which were used to measure serum selenium. Results Individuals who had both high serum selenium (>140 mcg/L) and high reported folate (>354 mcg/day), had a reduced relative risk of colon cancer (OR=0.5, 95% CI=0.4,0.8). The risk of colon cancer for those with high selenium and low folate was approximately equal to the risk among those with low selenium and low folate (OR=1.1, 95% CI=0.7,1.5) as was the risk for those with low selenium and high folate (OR=0.9, 95% CI=0.7–1.2). We did not find evidence of bias due to weight loss, stage at diagnosis, or time from diagnosis to selenium measurement. Conclusion High levels of serum selenium and reported folate jointly were associated with a substantially reduced risk of colon cancer. Folate status should be taken into account when evaluating the relation between selenium and colon cancer in future studies. Importantly, weight loss, stage at diagnosis, or time from diagnosis to blood draw did not appear to produce strong bias in our study. PMID:19235033

  13. Reference percentiles for FEV1 and BMI in European children and adults with cystic fibrosis

    PubMed Central

    2012-01-01

    Background The clinical course of Cystic Fibrosis (CF) is usually measured using the percent predicted FEV1 and BMI Z-score referenced against a healthy population, since achieving normality is the ultimate goal of CF care. Referencing against age and sex matched CF peers may provide valuable information for patients and for comparison between CF centers or populations. Here, we used a large database of European CF patients to compute CF specific reference equations for FEV1 and BMI, derived CF-specific percentile charts and compared these European data to their nearest international equivalents. Methods 34859 FEV1 and 40947 BMI observations were used to compute European CF specific percentiles. Quantile regression was applied to raw measurements as a function of sex, age and height. Results were compared with the North American equivalent for FEV1 and with the WHO 2007 normative values for BMI. Results FEV1 and BMI percentiles illustrated the large variability between CF patients receiving the best current care. The European CF specific percentiles for FEV1 were significantly different from those in the USA from an earlier era, with higher lung function in Europe. The CF specific percentiles for BMI declined relative to the WHO standard in older children. Lung function and BMI were similar in the two largest contributing European Countries (France and Germany). Conclusion The CF specific percentile approach applied to FEV1 and BMI allows referencing patients with respect to their peers. These data allow peer to peer and population comparisons in CF patients. PMID:22958330

  14. Waist circumference percentile thresholds for identifying adolescents with insulin resistance in clinical practice.

    PubMed

    Lee, Joyce M; Davis, Matthew M; Woolford, Susan J; Gurney, James G

    2009-08-01

    We formally evaluated waist circumference (WC) percentile cutoffs for predicting insulin resistance (IR) and whether different cutoffs should be used for adolescents of different race/ethnicities. Analysis was performed for 1575 adolescents aged 12-18 yr from the National Health and Nutrition Examination Survey 1999-2002. Adolescents were classified as having IR if they had a homeostasis model assessment-insulin resistance level, a validated measure of IR, of >4.39, and WC percentile was classified according to previously published universal (all races combined) and race/ethnicity-specific WC percentile cutoffs. Receiver operating characteristic curves for predicting IR were constructed comparing the race/ethnicity-specific vs. universal WC percentile cutoffs, and area under the curve (AUC) was calculated. Comparing universal with race/ethnicity-specific WC percentiles, there were no significant differences in AUC for Black, Mexican-American, or White adolescents. Because race/ethnicity-specific thresholds did not discriminate better than universal WC thresholds, universal WC thresholds may be used effectively to identify adolescents with IR in primary care practices. A WC > or =75th or > or =90th percentile for all race/ethnicities combined would be appropriate to apply in clinical practice for identification of adolescents with IR, a risk factor for development of type 2 diabetes.

  15. 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...

  16. 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

  17. Use of Pearson's Chi-Square for Testing Equality of Percentile Profiles across Multiple Populations.

    PubMed

    Johnson, William D; Beyl, Robbie A; Burton, Jeffrey H; Johnson, Callie M; Romer, Jacob E; Zhang, Lei

    2015-08-01

    In large sample studies where distributions may be skewed and not readily transformed to symmetry, it may be of greater interest to compare different distributions in terms of percentiles rather than means. For example, it may be more informative to compare two or more populations with respect to their within population distributions by testing the hypothesis that their corresponding respective 10(th), 50(th), and 90(th) percentiles are equal. As a generalization of the median test, the proposed test statistic is asymptotically distributed as Chi-square with degrees of freedom dependent upon the number of percentiles tested and constraints of the null hypothesis. Results from simulation studies are used to validate the nominal 0.05 significance level under the null hypothesis, and asymptotic power properties that are suitable for testing equality of percentile profiles against selected profile discrepancies for a variety of underlying distributions. A pragmatic example is provided to illustrate the comparison of the percentile profiles for four body mass index distributions.

  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.

  19. 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

  20. Using Percentile Schedules to Increase Eye Contact in Children With Fragile X Syndrome

    PubMed Central

    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. Results showed that although aversion to eye contact is often thought to be unamenable to change in FXS, it can be shaped in some individuals using percentile schedules either alone or in combination with overcorrection. PMID:19721738

  1. Using percentile schedules to increase eye contact in children with Fragile X syndrome.

    PubMed

    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. Results showed that although aversion to eye contact is often thought to be unamenable to change in FXS, it can be shaped in some individuals using percentile schedules either alone or in combination with overcorrection.

  2. [Selenium correction of male subfertility].

    PubMed

    Nikolaev, A A; Lutskiĭ, D L; Lozhkina, L V; Bochanovskiĭ, V A; Goncharova, L A

    1999-01-01

    To study the effect of selenium in subfertile men, three groups of men were studied. Group 1--31 subfertile men living in healthy environment, group 2--25 subfertile men exposed for a long time to low doses of gas containing hydrogen sulfide, group 3--control 43 fertile men. Men of groups 1 and 2 received 3 courses of selenium (3.5 microg/kg/day for 30 days). Before the treatment and after each course ejaculate fertility was assessed by spermogram, enzyme activity of alpha-amylase (EC 3.2.1.1) and lactate dehydrogenase (EC 1.1.1.27), concentrations of prostatic acid phosphatase, sperm-specific inhibitor tripsin and prostate-specific antigen. Selenium proved effective, the response being higher in group 2 than in group 1. The causes of this difference are discussed. It is thought possible to use selenium for correction of some subfertility forms in men.

  3. 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.

  4. 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…

  5. Stature-for-Age and Weight-for-Age Percentiles: Boys, 2 to 20 Years

    MedlinePlus

    2 to 20 years: Boys NAME Stature-for-age and Weight-for-age percentiles RECORD # Mother’s Stature Date Age in cm 160 62 S 155 60 T 150 ... 14 15 16 17 18 19 20 BMI* AGE (YEARS) cm 95 190 90 185 75 180 ...

  6. 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…

  7. 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…

  8. Empirical Percentile Growth Curves with Z-scores Considering Seasonal Compensatory Growths for Japanese Thoroughbred Horses

    PubMed Central

    ONODA, Tomoaki; YAMAMOTO, Ryuta; SAWAMURA, Kyohei; MURASE, Harutaka; NAMBO, Yasuo; INOUE, Yoshinobu; MATSUI, Akira; MIYAKE, Takeshi; HIRAI, Nobuhiro

    2013-01-01

    Percentile growth curves are often used as a clinical indicator to evaluate variations of children’s growth status. In this study, we propose empirical percentile growth curves using Z-scores adapted for Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Individual horses and residual effects were included as random effects in the growth curve equation model and their variance components were estimated. Based on the Z-scores of the estimated variance components, empirical percentile growth curves were constructed. A total of 5,594 and 5,680 body weight and age measurements of male and female Thoroughbreds, respectively, and 3,770 withers height and age measurements were used in the analyses. The developed empirical percentile growth curves using Z-scores are computationally feasible and useful for monitoring individual growth parameters of body weight and withers height of young Thoroughbred horses, especially during compensatory growth periods. PMID:24834004

  9. 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.…

  10. Covariate Measurement Error Correction for Student Growth Percentiles Using the SIMEX Method

    ERIC Educational Resources Information Center

    Shang, Yi; VanIwaarden, Adam; Betebenner, Damian W.

    2015-01-01

    In this study, we examined the impact of covariate measurement error (ME) on the estimation of quantile regression and student growth percentiles (SGPs), and find that SGPs tend to be overestimated among students with higher prior achievement and underestimated among those with lower prior achievement, a problem we describe as ME endogeneity in…

  11. 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.

  12. Acculturation determines BMI percentile and noncore food intake in Hispanic children.

    PubMed

    Wiley, James F; Cloutier, Michelle M; Wakefield, Dorothy B; Hernandez, Dominica B; Grant, Autherene; Beaulieu, Annamarie; Gorin, Amy A

    2014-03-01

    Hispanic children in the United States are disproportionately affected by obesity. The role of acculturation in obesity is unclear. This study examined the relation between child obesity, dietary intake, and maternal acculturation in Hispanic children. We hypothesized that children of more acculturated mothers would consume more unhealthy foods and would have higher body mass index (BMI) percentiles. A total of 209 Hispanic mothers of children aged 2-4 y (50% female, 35.3 ± 8.7 mo, BMI percentile: 73.1 ± 27.8, 30% obese, 19% overweight) were recruited for an obesity prevention/reversal study. The associations between baseline maternal acculturation [Brief Acculturation Rating Scale for Mexican Americans-II (Brief ARSMA-II)], child BMI percentile, and child diet were examined. Factor analysis of the Brief ARSMA-II in Puerto Rican mothers resulted in 2 new factors, which were named the Hispanic Orientation Score (4 items, loadings: 0.64-0.81) and U.S. Mainland Orientation Score (6 items, loadings: -0.61-0.92). In the total sample, children who consumed more noncore foods were more likely to be overweight or obese (P < 0.01). Additionally, children of mothers with greater acculturation to the United States consumed more noncore foods (P < 0.0001) and had higher BMI percentiles (P < 0.04). However, mothers with greater Hispanic acculturation served fewer noncore foods (P < 0.0001). In the Puerto Rican subgroup of mothers, Puerto Rican mothers with greater acculturation to the United States served more noncore foods (P < 0.0001), but there was no association between acculturation and child BMI percentile in this subgroup. These mothers, however, served fewer sugar-sweetened beverages (P < 0.01) compared with non-Puerto Rican mothers, and this may have negated the effect of noncore food consumption on BMI percentile. These data suggest a complex relation between acculturation, noncore food consumption, and child BMI percentile in Puerto Rican and non-Puerto Rican

  13. 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.

  14. 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.

  15. Selenium availability in Texas: possible clinical significance

    SciTech Connect

    Cech, I.; Holguin, A.; Sokolow, H.; Smith, V.

    1984-11-01

    In light of recent reports that have indicated that selenium is an essential micronutrient and possible natural cancer inhibitor, data on the geographic distributions of selenium in Texas were gathered and compared with the distribution of age-adjusted cancer mortality rates. We considered concentrations of selenium measured in ground and surface water to be indicators of its presence in rocks, soil, and locally grown crops. Texas water sources were found to be poor in selenium, except for the Panhandle and the West Texas regions, where soil consists of erosion products from the selenium-rich Rocky Mountains. In general, lower cancer mortality was observed for the selenium-rich regions of Texas compared with cancer mortality for the selenium poor regions. Even though the risks from cancer-provoking factors also differed geographically, the observed pattern was sufficiently suggestive to warrant further attention to selenium. 13 references, 4 figures, 2 tables.

  16. 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.

  17. [Selenium deficiency and infertility. Andrologic aspects].

    PubMed

    Szöllosi, János; Závaczki, Zoltán; Pál, Attila

    2008-09-14

    Absolute selenium deficiency in human is very rare, although suboptimal daily selenium intake may lead to an unrecognized relative deficiency. Among the many consequences ascribed to decreased selenium level, the effect on male fertility is summarised by the authors. Implications from biochemical, animal experimental and human research are discussed.

  18. 21 CFR 573.920 - Selenium.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Selenium. 573.920 Section 573.920 Food and Drugs... Listing § 573.920 Selenium. (a) Public Law 103-354 enacted October 13, 1994 (the 1994 Act), states that... Act; unless the Commissioner of Food and Drugs makes a determination that: (1) Selenium additives...

  19. 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... Listing § 573.920 Selenium. (a) Public Law 103-354 enacted October 13, 1994 (the 1994 Act), states that... Act; unless the Commissioner of Food and Drugs makes a determination that: (1) Selenium additives...

  20. 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... Listing § 573.920 Selenium. (a) Public Law 103-354 enacted October 13, 1994 (the 1994 Act), states that... Act; unless the Commissioner of Food and Drugs makes a determination that: (1) Selenium additives...

  1. Generation of selenium-enriched rice with enhanced grain yield, selenium content and bioavailability through fertilisation with selenite.

    PubMed

    Wang, Yu-Dong; Wang, Xu; Wong, Yum-Shing

    2013-12-01

    To fulfill the natural human needs of selenium, selenium biofortification has been carried out in rice (Oryza sativa) in recent years. Despite some improvements have been made, the increase of selenium content in rice was still limited and a large amount of fertilisers are often required, which may cause environmental pullution. In this study, we further improved the selenium biofortification of rice by using less selenium fertilisers (10.5 g selenium/hectare) whereas, largely increasing selenium content in rice grains (up to 51 times vs. control). Furthermore, selenium speciation analysis, in vitro gastrointestinal digestion and antioxidant assays were performed to evaluate the selenium bioaccessibility and bioavailability in selenium-enriched rice grains. The major selenium species found were readily absorbable selenomethionine. Meanwhile, the selenium-enriched rice grains have significantly higher antioxidant bioactivities. In conclusion, this selenium-enriched rice has enormous potential for selenium supplementation in humans.

  2. Selenium accumulation by plants

    PubMed Central

    White, Philip J.

    2016-01-01

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

  3. Plotting equation for gaussian percentiles and a spreadsheet program for generating probability plots

    USGS Publications Warehouse

    Balsillie, J.H.; Donoghue, J.F.; Butler, K.M.; Koch, J.L.

    2002-01-01

    Two-dimensional plotting tools can be of invaluable assistance in analytical scientific pursuits, and have been widely used in the analysis and interpretation of sedimentologic data. We consider, in this work, the use of arithmetic probability paper (APP). Most statistical computer applications do not allow for the generation of APP plots, because of apparent intractable nonlinearity of the percentile (or probability) axis of the plot. We have solved this problem by identifying an equation(s) for determining plotting positions of Gaussian percentiles (or probabilities), so that APP plots can easily be computer generated. An EXCEL example is presented, and a programmed, simple-to-use EXCEL application template is hereby made publicly available, whereby a complete granulometric analysis including data listing, moment measure calculations, and frequency and cumulative APP plots, is automatically produced.

  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 and immune responses

    SciTech Connect

    Kiremidjian-Schumacher, L.; Stotzky, G.

    1987-04-01

    Selenium (Se) affects all components of the immune system, i.e., the development and expression of nonspecific, humoral, and cell-mediated responses. In general, a deficiency in Se appears to result in immunosuppression, whereas supplementation with low doses of Se appears to result in augmentation and/or restoration of immunologic functions. A deficiency of Se has been shown to inhibit (1) resistance to microbial and viral infections, (2) neutrophil function, (3) antibody production, (4) proliferation of T and B lymphocytes in response to mitogens, and (5) cytodestruction by T lymphocytes and NK cells. Supplementation with Se has been shown to stimulate (1) the function of neutrophils, (2) production of antibodies, (3) proliferation of T and B lymphocytes in response to mitogens, (4) production of lymphokines, (5) NK cell-mediated cytodestruction, (6) delayed-type hypersensitivity reactions and allograft rejection, and (7) the ability of a host to reject transplanted malignant tumors. The mechanism(s) whereby Se affects the immune system is speculative. The effects of Se on the function of glutathione peroxidase and on the cellular levels of reduced glutathione and H/sub 2/Se, as well as the ability of Se to interact with cell membranes, probably represent only a few of many regulatory mechanisms. The manipulation of cellular levels of Se may be significant for the maintenance of general health and for the control of immunodeficiency disorders and the chemoprevention of cancer.

  6. Percentile Analysis for Goodness-of-Fit Comparisons of Models to Data

    DTIC Science & Technology

    2014-07-01

    Science, 1, 11-38. Roberts, S., & Pashler, H. (2000). How persuasive is a good fit ? A comment on theory testing . Psychological Review, 107, 358-367...Percentile analysis for goodness -of- fit comparisons of models to data Sangeet Khemlani and J. Gregory Trafton skhemlani@gmail.com, trafton...modeling, it is routine to report a goodness -of- fit index (e.g., R2 or RMSE) between a putative model’s predictions and an observed dataset

  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 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.

  9. 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.

  10. Resulting Shifts in Percentile and Standard Placements after Comparison of the BOD POD and DXA

    PubMed Central

    HEDEN, TIMOTHY; SHEPARD, STEVE; SMITH, JOHN; COVINGTON, KAY; LECHEMINANT, JAMES

    2008-01-01

    The purpose of this study was to determine the validity of the BOD POD® when compared to the DXA and if placement on a percentile chart and standard table is affected by any differences between the two measures. A total of 244 (27.7 ± 10.8 yrs, 77.3 ± 16.1 kg, 171.4 ± 10.1 cm, 26.31 ± 5.42 BMI) males and females between the ages of 18 and 52 were recruited to participate in this study. The participant’s body fat percentage (%BF) was tested in random order on the BOD POD® and DXA during a 30-minute session following manufacturer’s guidelines and procedures. Dependent t-test indicated the %BF measured by the BOD POD® (23.4% ± 12.8) was significantly lower when compared to the DXA (29.5% ± 12.1), p = .001. The Pearson’s Product moment correlation was 0.95 (p = .001), indicating a very strong relationship between the two instruments. Using estimates of %BF from the BOD POD® also resulted in more favorable shifts on a percentile chart and standard table. Since a high correlation was evident between the two, the BOD POD® can be used as an instrument to track %BF changes over time during a diet and/or exercise intervention. However, caution should be made when classifying %BF with percentile charts or standard tables using the BOD POD® %BF estimates. PMID:27182302

  11. Adaptive urn designs for estimating several percentiles of a dose--response curve.

    PubMed

    Mugno, Raymond; Zhus, Wei; Rosenberger, William F

    2004-07-15

    Dose--response experiments are crucial in biomedical studies. There are usually multiple objectives in such experiments and among the goals is the estimation of several percentiles on the dose--response curve. Here we present the first non-parametric adaptive design approach to estimate several percentiles simultaneously via generalized Pólya urns. Theoretical properties of these designs are investigated and their performance is gaged by the locally compound optimal designs. As an example, we re-investigated a psychophysical experiment where one of the goals was to estimate the three quartiles. We show that these multiple-objective adaptive designs are more efficient than the original single-objective adaptive design targeting the median only. We also show that urn designs which target the optimal designs are slightly more efficient than those which target the desired percentiles directly. Guidelines are given as to when to use which type of design. Overall we are pleased with the efficiency results and hope compound adaptive designs proposed in this work or their variants may prove to be a viable non-parametric alternative in multiple-objective dose--response studies.

  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. 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.

  14. Selenium status in Greenland Inuit.

    PubMed

    Hansen, Jens C; Deutch, Bente; Pedersen, Henning Sloth

    2004-09-20

    In Greenland, the human intake of selenium has always been relatively high and is closely connected to intake of the traditional food of marine origin. Analyses of historic and present day human and animal hair samples have indicated that the selenium level in the marine environment has been constant over time, while the levels in humans have declined corresponding to a decrease in intake of traditional food. The Inuit population in Greenland is in dietary transition where western-style food will increasingly dominate. As a consequence, the ample supply of selenium may not be sustained in the future. We report here the selenium status in three Greenlandic population groups, Ittoqqortoormiit and Tasiilaq on the east coast and Uummannaq on the west coast. Mean whole blood concentrations ranged from 178 microg/l in Tasiilaq men to 488 microg/l in Uummannaq men. Plasma concentrations ranged from 79 microg/l in Tasiilaq women to 113 microg/l in Uummannaq men. With increasing Se concentrations in whole blood, the plasma concentrations increased but tended to stabilise a level approximately 140 microg/l. Selenium blood levels were highly significantly correlated with long chain marine fatty acids. Dietary survey and food composition data from the west coast showed that whale skin, muktuk, is the main source of Se followed by birds, seal meat and organs, and fish. Terrestrial animals contributed only insignificantly to the selenium intake. In West Greenland, daily Se intake (235 microg/day) was estimated by dietary survey; it corresponded well with a calculated intake (220 microg/day) based on the mean blood concentration.

  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. Selenium and endocrine systems.

    PubMed

    Beckett, Geoffrey J; Arthur, John R

    2005-03-01

    The trace element selenium (Se) is capable of exerting multiple actions on endocrine systems by modifying the expression of at least 30 selenoproteins, many of which have clearly defined functions. Well-characterized selenoenzymes are the families of glutathione peroxidases (GPXs), thioredoxin reductases (TRs) and iodothyronine deiodinases (Ds). These selenoenzymes are capable of modifying cell function by acting as antioxidants and modifying redox status and thyroid hormone metabolism. Se is also involved in cell growth, apoptosis and modifying the action of cell signalling systems and transcription factors. During thyroid hormone synthesis GPX1, GPX3 and TR1 are up-regulated, providing the thyrocytes with considerable protection from peroxidative damage. Thyroidal D1 in rats and both D1 and D2 in humans are also up-regulated to increase the production of bioactive 3,5,3'-tri-iodothyronine (T3). In the basal state, GPX3 is secreted into the follicular lumen where it may down-regulate thyroid hormone synthesis by decreasing hydrogen peroxide concentrations. The deiodinases are present in most tissues and provide a mechanism whereby individual tissues may control their exposure to T3. Se is also able to modify the immune response in patients with autoimmune thyroiditis. Low sperm production and poor sperm quality are consistent features of Se-deficient animals. The pivotal link between Se, sperm quality and male fertility is GPX4 since the enzyme is essential to allow the production of the correct architecture of the midpiece of spermatozoa. Se also has insulin-mimetic properties, an effect that is probably brought about by stimulating the tyrosine kinases involved in the insulin signalling cascade. Furthermore, in the diabetic rat, Se not only restores glycaemic control but it also prevents or alleviates the adverse effects that diabetes has on cardiac, renal and platelet function.

  17. Radioprotection by metals: Selenium

    NASA Astrophysics Data System (ADS)

    Weiss, J. F.; Srinivasan, V.; Kumar, K. S.; Landauer, M. R.

    The need exists for compounds that will protect individuals from high-dose acute radiation exposure in space and for agents that might be less protective but less toxic and longer acting. Metals and metal derivatives provide a small degree of radioprotection (dose reduction factor <= 1.2 for animal survival after whole-body irradiation). Emphasis is placed here on the radioprotective potential of selenium (Se). Both the inorganic salt, sodium selenite, and the organic Se compound, selenomethionine, enhance the survival of irradiated mice (60Co, 0.2 Gy/min) when injected IP either before (-24 hr and -1 hr) or shortly after (+15 min) radiation exposure. When administered at equitoxic doses (one-fourth LD10; selenomethionine = 4.0 mg/kg Se, sodium selenite = 0.8 mg/kg Se), both drugs enhanced the 30-day survival of mice irradiated at 9 Gy. Survival after 10-Gy exposure was significantly increased only after selenomethionine treatment. An advantage of selenomethionine is lower lethal and behavioral toxicity (locomotor activity depression) compared to sodium selenite, when they are administered at equivalent doses of Se. Sodium selenite administered in combination with WR-2721, S-2-(3-aminopropylamino)ethylphosphorothioic acid, enhances the radioprotective effect and reduces the lethal toxicity, but not the behavioral toxicity, of WR-2721. Other studies on radioprotection and protection against chemical carcinogens by different forms of Se are reviewed. As additional animal data and results from human chemoprevention trials become available, consideration also can be given to prolonged administration of Se compounds for protection against long-term radiation effects in space.

  18. In vitro bioavailability of total selenium and selenium species from seafood.

    PubMed

    Moreda-Piñeiro, Jorge; Moreda-Piñeiro, Antonio; Romarís-Hortas, Vanessa; Domínguez-González, Raquel; Alonso-Rodríguez, Elia; López-Mahía, Purificación; Muniategui-Lorenzo, Soledad; Prada-Rodríguez, Darío; Bermejo-Barrera, Pilar

    2013-08-15

    In vitro bioavailability of total selenium and selenium species from different raw seafood has been assessed by using a simulated gastric and intestinal digestion/dialysis method. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to assess total selenium contents after a microwave assisted acid digestion, and also to quantify total selenium in the dialyzable and non-dialyzable fractions. Selenium speciation in the dialyzates was assessed by high performance liquid chromatography (HPLC) coupled with ICP-MS detection. Major Se species (selenium methionine and oxidized selenium methionine) from dialyzate were identified and characterized by HPLC coupled to mass spectrometry (HPLC-MS). Selenocystine was detected at low concentrations while Se-(Methyl)selenocysteine and inorganic selenium species (selenite and selenate) were not detected in the dialyzate. Low bioavailability percentages for total selenium (6.69±3.39 and 5.45±2.44% for fish and mollusk samples, respectively) were obtained. Similar bioavailability percentages was achieved for total selenium as a sum of selenium species (selenocystine plus oxidized selenium methionine and selenium methionine, mainly). HPLC-MS data confirmed SeMet oxidation during the in vitro procedure.

  19. Entrapped elemental selenium nanoparticles affect physicochemical properties of selenium fed activated sludge.

    PubMed

    Jain, Rohan; Seder-Colomina, Marina; Jordan, Norbert; Dessi, Paolo; Cosmidis, Julie; van Hullebusch, Eric D; Weiss, Stephan; Farges, François; Lens, Piet N L

    2015-09-15

    Selenite containing wastewaters can be treated in activated sludge systems, where the total selenium is removed from the wastewater by the formation of elemental selenium nanoparticles, which are trapped in the biomass. No studies have been carried out so far on the characterization of selenium fed activated sludge flocs, which is important for the development of this novel selenium removal process. This study showed that more than 94% of the trapped selenium in activated sludge flocs is in the form of elemental selenium, both as amorphous/monoclinic selenium nanospheres and trigonal selenium nanorods. The entrapment of the elemental selenium nanoparticles in the selenium fed activated sludge flocs leads to faster settling rates, higher hydrophilicity and poorer dewaterability compared to the control activated sludge (i.e., not fed with selenite). The selenium fed activated sludge showed a less negative surface charge density as compared to the control activated sludge. The presence of trapped elemental selenium nanoparticles further affected the spatial distribution of Al and Mg in the activated sludge flocs. This study demonstrated that the formation and subsequent trapping of elemental selenium nanoparticles in the activated sludge flocs affects their physicochemical properties.

  20. Metabolic interrelationships between arsenic and selenium

    PubMed Central

    Levander, Orville A.

    1977-01-01

    In 1938, Moxon discovered that arsenic protected against selenium toxicity. Since that time it has been shown that this protective effect of arsenic against selenium poisoning can be demonstrated in many different animal species under a wide variety of conditions. Antagonistic effects between arsenic and selenium have also been noted in teratologic experiments. Early metabolic studies showed that arsenic inhibited the expiration of volatile selenium compounds by rats injected with acutely toxic doses of both elements. This was puzzling since pulmonary excretion had long been regarded as a means by which animals could rid themselves of excess selenium. However, later work demonstrated that arsenic increased the biliary excretion of selenium. Not only did arsenic stimulate the excretion of selenium in the bile, but selenium also stimulated the excretion of arsenic in the bile. This increased biliary excretion of selenium caused by arsenic provides a reasonable rationale for the ability of arsenic to counteract the toxicity of selenium, although the chemical mechanism by which arsenic does this is not certain. The most satisfactory explanation is that these two elements react in the liver to form a detoxication conjugate which is then excreted into the bile. This is consistent with the fact that both arsenic and selenium each increase the biliary excretion of the other. Several other metabolic interactions between arsenic and selenium have been demonstrated in vitro, but their physiological significance is not clear. Although arsenic decreased selenium toxicity under most conditions, there is a pronounced synergistic toxicity between arsenic and two methylated selenium metabolites, trimethylselenonium ion or dimethyl selenide. The ecological consequences of these synergisms are largely unexplored, although it is likely that selenium methylation occurs in the environment. All attempts to promote or prevent selenium deficiency diseases in animals by feeding arsenic have

  1. Selenium in soybeans: bioavailability and form

    SciTech Connect

    Mason, A.C.

    1984-01-01

    Experiments are presented which evaluate the bioavailability of different forms of selenium from intrinsically and extrinsically labeled isolated soy protein and soy flour. The bioavailability of selenium from soy and egg is compared and some characteristics of selenium are described as it exists in soybeans. The metabolism of selenium was measured by whole-body and tissue radioactivity retention and selenium excretion. Selenium-75 was well absorbed from an isolated soy protein diet by rats. Selenium-75 from isolated soy protein labeled intrinsically and extrinsically with /sup 75/Se selenate was better absorbed than from protein labeled extrinsically with /sup 75/Se selenite or /sup 75/Se selenomethionine. Bioavailability of selenium from soy flour and egg was measured by whole-body and tissue radioactivity retention and glutathione peroxidase (GSH-Px) activity regeneration. Selenium-75 from soy flour intrinsically labeled with selenite was better absorbed than /sup 75/Se from flour intrinsically labeled with selenate. GSH-Px levels in the liver, kidney, platelets and heart fell when rats were fed a selenium deficient diet, but were not significantly raised on 0.0825 ppm Se repletion diets.

  2. 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.

  3. 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.

  4. Chemical form of selenium in naturally selenium-rich lentils (Lens culinaris L.) from Saskatchewan.

    PubMed

    Thavarajah, Dil; Vandenberg, Albert; George, Graham N; Pickering, Ingrid J

    2007-09-05

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

  5. 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

  6. Individual variability in preference for energy-dense foods fails to predict child BMI percentile.

    PubMed

    Potter, Christina; Griggs, Rebecca L; Ferriday, Danielle; Rogers, Peter J; Brunstrom, Jeffrey M

    2017-04-01

    Many studies show that higher dietary energy density is associated with greater body weight. Here we explored two propositions: i) that child BMI percentile is associated with individual differences in children's relative preference for energy-dense foods, ii) that child BMI percentile is associated with the same individual differences between their parents. Child-parent dyads were recruited from a local interactive science center in Bristol (UK). Using computerized tasks, participants ranked their preference and rated their liking for a range of snack foods that varied in energy density. Children (aged 3-14years, N=110) and parents completed the tasks for themselves. Parents also completed two further tasks in which they ranked the foods in the order that they would prioritize for their child, and again, in the order that they thought their child would choose. Children preferred (t(109)=3.91, p<0.001) and better liked the taste of (t(109)=3.28, p=0.001) higher energy-dense foods, and parents correctly estimated this outcome (t(109)=7.18, p<0.001). Conversely, lower energy-dense foods were preferred (t(109)=-4.63, p<0.001), better liked (t(109)=-2.75, p=0.007) and served (t(109)=-15.06, p<0.001) by parents. However, we found no evidence that child BMI percentile was associated with child or parent preference for, or liking of, energy-dense foods. Therefore, we suggest that the observed relationship between dietary energy density and body weight is not explained by individual differences in preference for energy density.

  7. Waist circumference percentiles among Turkish children under the age of 6 years.

    PubMed

    Hatipoglu, Nihal; Mazicioglu, M Mumtaz; Poyrazoglu, Serpil; Borlu, Arda; Horoz, Duygu; Kurtoglu, Selim

    2013-01-01

    Waist circumference, a proxy measure of abdominal obesity, is associated with cardio-metabolic risk factors in childhood and adolescence. Although there are numerous studies about waist circumference percentiles in children, only a few studies cover preschool children. The aim of this study was to develop age- and gender-specific waist circumference smoothed reference curves in Turkish preschool children to determine abdominal obesity prevalence and to compare them with reference curves obtained from different countries. The design of the study was cross-sectional. A total of 2,947 children (1,471 boys and 1,476 girls) aged 0-6 years were included in the study. The subjects were divided according to their gender. Waist circumference was measured by using a standardized procedure. The age- and gender-specific waist circumference reference curves were constructed and smoothed with LMS method. The reference values of waist circumference, including 3rd, 10th 25th, 50th, 75th, 90th, and 97th percentiles, and standard deviations were given for preschool children. Waist circumference values increased with age, and there were differences between genders. The prevalence of abdominal obesity was calculated as 10.1 % for boys and 10.7 % for girls. Having compared our data with two other countries' data, we found that our waist circumference data were significantly lower. This is the first cross-sectional study for age- and gender-specific references of 0- to 6-year-old Turkish children. The gender- and age-specific waist circumference percentiles can be used to determine the risk of central obesity.

  8. 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...

  9. 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.

  10. Evaluation of short neck: new neck length percentiles and linear correlations with height and sitting height.

    PubMed

    Mahajan, P V; Bharucha, B A

    1994-10-01

    Qualitative impressions of neck length are often used as aids to dysmorphology in syndromes like Turner, Noonan, Klippel-Feil and in craniovertebral anomalies, some of which have serious neurological implications. There are no national or international standards for neck length. The present study attempted to create standards and percentile charts for Indian children and compute age-independent correlations of neck length with linear measurements such as standing and sitting height. A total of 2724 children of both sexes between 3 and 15 years, whose heights and weights conformed to ICMR standards were inducted. Neck length was measured by a modified two-point discriminator between two fixed bony points-inion and spinous process of C7 with the head held in neutral position. Percentiles (5th-95th) were constructed for both sexes. Growth was rapid from 3 to 6 years. Neck length formed a mean of 12.7 +/- 4.58% of height and 20.1 +/- 6.73% of sitting height. Age independent linear regression equations: Neck length = 10 + (0.035 x height) and Neck length = 9.65 + (0.07 x sitting height) were highly significant (p < 0.001). Neck length relationships of 30 randomly selected normal children clustered around the regression lines and 16 with genetic syndromes fell below the regression lines.

  11. 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.

  12. 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.

  13. Protocol for aquatic hazard assessment of selenium

    SciTech Connect

    Lemly, A.D.

    1995-05-24

    A procedure is described for conducting an aquatic hazard assessment of selenium. Hazard is characterized in terms of the potential for food-chain bioaccumulation and reproductive impairment in fish and aquatic birds, which are the most sensitive biological responses for estimating ecosystem-level impacts of selenium contamination. Five degrees of hazard are possible depemding on the expected environmental concentrations of selenium, exposure of fish and aquatic birds to toxic concentrations, and resultant potential for reproductive impairment. An example is given to illustrate how the protocol is applied to selenium data from a typical contaminant monitoring program.

  14. Increased hair selenium concentration in hyperlipidemic patients

    PubMed Central

    Fülöp, Péter; Seres, Ildikó; Jenei, Zoltán; Juhász, Imre; Paragh, György

    2013-01-01

    Selenium is an essential trace element with potential anti-atherogenic and antioxidant effects. Experimental data suggest that selenium might be beneficial in the prevention of atherosclerosis and its complications, whereas human epidemiological studies have yielded conflicting results. Data on hair selenium status in hyperlipidemic patients are still lacking. Therefore, we analysed selenium concentrations by X-ray fluorescence in the hair of 81 statin-naïve patients with newly diagnosed Fredrickson-type IIa and IIb hyperlipoproteinemia and compared their data with 43 healthy volunteers. We also assessed the frequency of other classical risk factors of atherosclerosis. Hair selenium levels were found to be significantly higher in hyperlipidemic patients compared with volunteers with normal lipid levels. Also, a significantly increased number of traditional atherosclerosis risk factors were observed in hyperlipidemic patients with hair selenium concentrations above the median in contrast to those with below. Our results suggest that high hair selenium status might be associated with adverse blood lipid profile together with an increased number of traditional risk factors in a selenium-deplete population. These findings warrant further investigations to study the impact of selenium supplementation on the incidence of cardiovascular events. PMID:23402643

  15. Kinetic determination of selenium in biological material

    SciTech Connect

    Efremenko, O.A.; Krasnyuk, I.I.; Kudrin, A.N.; Rudenko, B.A.

    1986-05-10

    A very promising method for selenium determination is a kinetic analytical procedure that combines the simplicity and availability of physical instrumentation with a low analyte detection limit. This paper reports a modification of the method to enable the determination of selenium in rat blood and involves decomposing the sample with a mixture of nitric and perchloric acids, separation of the selenium (IV) from other decomposition products, and quantitatively determining selenium by the described kinetic method using the indicator reaction of iron (II) edetate oxidation by sodium nitrate.

  16. Selenium in ruminant nutrition: a review.

    PubMed

    Ammerman, C B; Miller, S M

    1975-10-01

    The early interest in selenium related primarily to its toxicity, but since 1957 the element has been recognized as a dietary essential. The dietary requirement for selenium by most species is about .1 ppm. Deficiencies of selenium in cattle and sheep have been confirmed under natural grazing conditions in many countries of the world. Overt signs of inadequacy such as white muscle disease (nutritional muscular dystrophy) occur primarily in young calves or lambs born to selenium deficient dams. Infertility has increased in ewes grazing pastures low in selenium. In general, signs of deficiency have not occurred in older animals such as finishing beef cattle and lactating dairy cows. Subclinical deficiencies of selenium are not determined easily, however, and thus an inadequacy of the element may be limiting maximum animal performance under certain circumstances of drylot feeding. The current nutritional status of ruminant animals in many geographical areas and involving various feeding programs with this element has not been established. The recent widespread deficiency problems with nonruminants suggest that such an assessment should be made. Concentration of selenium in tissue, particularly in the liver, has been used in establishing selenium status of the animal. With lambs glutathione peroxidase activity in certain tissues may be a more accurate indicator of selenium adequacy than is selenium content of the tissue. Supplemental sodium selenite and sodium selenate by either oral administration or parenteral injection have prevented clinical signs of selenium deficiency and animal losses in both ruminant and nonruminant animals. Heavy pellets containing elemental selenium for placement in the rumen have proved effective. In general, organic forms of selenium are absorbed more readily by animals than are inorganic compounds. The dietary requirements for selenium and its metabolism are influenced by many nutrient interrelationships, including its interactions with

  17. 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

  18. 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.

  19. Producing selenium-enriched eggs and meat to improve the selenium status of the general population.

    PubMed

    Fisinin, Vladimir I; Papazyan, Tigran T; Surai, Peter F

    2009-01-01

    The role of selenium (Se) in human health and diseases has been discussed in detail in several recent reviews, with the main conclusion being that selenium deficiency is recognised as a global problem which urgently needs resolution. Since selenium content in plant-based food depends on its availability from soil, the level of this element in food and feeds varies among regions. In general, eggs and meat are considered to be good sources of selenium in human diet. When considering ways to improve human selenium intake, there are several potential options. These include direct supplementation, soil fertilisation and supplementation of food staples such as flour, and production of functional foods. Analysing recent publications related to functional food production, it is evident that selenium-enriched eggs can be used as an important delivery system of this trace mineral for humans. In particular, developments and commercialisation of organic forms of selenium have initiated a new era in the availability of selenium-enriched products. It has been shown that egg selenium content can easily be manipulated to give increased levels, especially when organic selenium is included in hens' diet at levels that provide 0.3-0.5 mg/kg selenium in the feed. As a result, technology for the production of eggs delivering approximately 50% (30-35 microg) of the human selenium RDA have been developed and successfully tested. Currently companies all over the world market selenium-enriched eggs including the UK, Ireland, Mexico, Columbia, Malaysia, Thailand, Australia, Turkey, Russia and the Ukraine. Prices for enriched eggs vary from country to country, typically being similar to free-range eggs. Selenium-enriched chicken, pork and beef can also be produced when using organic selenium in the diet of poultry and farm animals. The scientific, technological and other advantages and limitations of producing designer/modified eggs as functional foods are discussed in this review.

  20. 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.

  1. 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

  2. The effects of percentile versus fixed criterion schedules on smoking with equal incentive magnitude for initial abstinence.

    PubMed

    Romanowich, Paul; Lamb, R J

    2014-08-01

    Incentives have been successfully used to reduce smoking in hard-to-treat (HTT) smokers by progressively reinforcing lower levels of breath carbon monoxide (CO). When compared with schedules only providing incentives for smoking abstinence, using a progressive (percentile) criterion facilitates longer periods of smoking abstinence. However, participants receiving incentives for lower breath CO levels on percentile schedules typically earn more for their first abstinent breath CO sample relative to participants receiving incentives only for smoking abstinence. Many studies show that larger incentive magnitude increases abstinence rates. The present study tested the effects of different incentive schedules on rates of abstinence maintenance while holding the initial incentive magnitude constant for 93 HTT smokers to eliminate initial abstinence incentive magnitude as a potential confound. Smokers were randomized to percentile, fixed criterion, or random incentive schedules. The incentive magnitude for the first abstinent breath CO sample (<3 ppm) was $5 for percentile and fixed criterion incentive participants, and then increased by $0.50 for each consecutive abstinent breath CO sample. All groups had similar patterns of meeting the abstinence criterion for at least 1 visit. However, once this abstinence criterion was met, abstinence was more likely to be maintained by fixed criterion incentive participants. Unlike previous studies comparing percentile and fixed criterion schedules, percentile incentive schedules were not associated with longer periods of abstinence relative to fixed criterion incentive schedules. Further studies that manipulate initial incentive magnitude are needed to test whether the difference between the current and previous studies was due to initial incentive magnitude.

  3. Review of selenium thermodynamic data

    NASA Astrophysics Data System (ADS)

    Cowan, C. E.

    1988-02-01

    This report assesses the accuracy and completeness of available thermodynamic data on selenium. A review of experimental methods from published literature on selenium thermodynamic data focused on chemical reactions responsible for the formation of both aqueous complexes and solid phases of selenate, selenite, and selenide. The reviewer selected best data values, based on the methods used for estimating thermodynamic data. After inclusion of these values into the MINTEQ model, a validation study evaluated model performance for selenite and selenide solid phases. Lack of selenate data precluded model validation for this compound. The review furnished data on 22 aqueous complexes of selenite, 15 of selenide, and 17 of selenate, as well as 21 solid phases of selenite, 20 of selenide and 8 of selenate. These data proved inadequate to represent the formation of species in the solid phase. The validation study gave inconclusive predictions of selenite and selenide solubility and could not be used to assess the accuracy or completeness of the thermodynamic data.

  4. Evolution of selenium utilization traits

    PubMed Central

    Romero, Héctor; Zhang, Yan; Gladyshev, Vadim N; Salinas, Gustavo

    2005-01-01

    Background The essential trace element selenium is used in a wide variety of biological processes. Selenocysteine (Sec), the 21st amino acid, is co-translationally incorporated into a restricted set of proteins. It is encoded by an UGA codon with the help of tRNASec (SelC), Sec-specific elongation factor (SelB) and a cis-acting mRNA structure (SECIS element). In addition, Sec synthase (SelA) and selenophosphate synthetase (SelD) are involved in the biosynthesis of Sec on the tRNASec. Selenium is also found in the form of 2-selenouridine, a modified base present in the wobble position of certain tRNAs, whose synthesis is catalyzed by YbbB using selenophosphate as a precursor. Results We analyzed completely sequenced genomes for occurrence of the selA, B, C, D and ybbB genes. We found that selB and selC are gene signatures for the Sec-decoding trait. However, selD is also present in organisms that do not utilize Sec, and shows association with either selA, B, C and/or ybbB. Thus, selD defines the overall selenium utilization. A global species map of Sec-decoding and 2-selenouridine synthesis traits is provided based on the presence/absence pattern of selenium-utilization genes. The phylogenies of these genes were inferred and compared to organismal phylogenies, which identified horizontal gene transfer (HGT) events involving both traits. Conclusion These results provide evidence for the ancient origin of these traits, their independent maintenance, and a highly dynamic evolutionary process that can be explained as the result of speciation, differential gene loss and HGT. The latter demonstrated that the loss of these traits is not irreversible as previously thought. PMID:16086848

  5. Selenium and prostate cancer prevention: insights from the selenium and vitamin E cancer prevention trial (SELECT).

    PubMed

    Nicastro, Holly L; Dunn, Barbara K

    2013-04-03

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

  6. Preparation of selenium yeasts I. Preparation of selenium-enriched Saccharomyces cerevisiae.

    PubMed

    Suhajda, A; Hegóczki, J; Janzsó, B; Pais, I; Vereczkey, G

    2000-04-01

    Selenium (Se) is an essential micronutrient for human and animal organisms. Organic selenium complexes and selenium-containing amino acids are considered the most bioavailable. Under appropriate conditions yeasts are capable of accumulating large amounts of trace elements, such as selenium, and incorporating them into organic compounds. It has been found that introduction of water-soluble selenium salt as a component of the culture medium for yeasts produced by conventional batch processing results in a substantial amount of selenium being absorbed by the yeast. Using a culture medium supplemented with 30 microg/mL sodium-selenite added during the exponential growth phase results in selenium-accumulation in the range of 1200-1400 microg/g dried baker's yeast (Saccharomyces cerevisiae) measured by ICP-AES method. In our previous studies it was shown that higher amounts of sodium-selenite in the culture medium have a strong inhibitory effect on the growth of this yeast. As a consequence of variations in cultivation conditions we obtained selenium yeast with different inorganic selenium content. The most important parameters influencing incorporated forms of selenium are pH value and dissolved oxygen level in the culture medium, and depending on these the selenium consumption rate of the yeast. A 0.40-0.50 mg/g h-1 specific selenium consumption rate was found to be appropriate to obtain selenium-enriched bakers' yeast of a high quality. Under suitable conditions the undesirable inorganic selenium content of the yeast could be suppressed to as low as 5-6% at the expense, however, of approximately a 20% decrease in the final biomass.

  7. Regression Equations for Monthly and Annual Mean and Selected Percentile Streamflows for Ungaged Rivers in Maine

    USGS Publications Warehouse

    Dudley, Robert W.

    2015-12-03

    The largest average errors of prediction are associated with regression equations for the lowest streamflows derived for months during which the lowest streamflows of the year occur (such as the 5 and 1 monthly percentiles for August and September). The regression equations have been derived on the basis of streamflow and basin characteristics data for unregulated, rural drainage basins without substantial streamflow or drainage modifications (for example, diversions and (or) regulation by dams or reservoirs, tile drainage, irrigation, channelization, and impervious paved surfaces), therefore using the equations for regulated or urbanized basins with substantial streamflow or drainage modifications will yield results of unknown error. Input basin characteristics derived using techniques or datasets other than those documented in this report or using values outside the ranges used to develop these regression equations also will yield results of unknown error.

  8. 21 CFR 573.920 - Selenium.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Selenium. 573.920 Section 573.920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS... Act; unless the Commissioner of Food and Drugs makes a determination that: (1) Selenium additives...

  9. 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 ...

  10. Development of a simplified finite element model of the 50th percentile male occupant lower extremity.

    PubMed

    Schwartz, Doron; Moreno, Daniel P; Stitzel, Joel D; Gayzik, F Scott

    2014-01-01

    A simplified lower extremity model was developed using the geometry from the Global Human Body Models Consortium (GHBMC) 50th percentile male occupant model v4.1.1 (M50) as a base. This simplified model contains 31.4x103 elements and has structures that represent bone (assumed rigid) and soft tissue. This element total is substantially reduced compared to 117.7x103 elements in the original M50 lower extremity. The purpose of this simplified computational model is to output rapid kinematic and kinetic data when detailed structural response or injury prediction data is not required. The development process included evaluating the effects of element size, material properties, and contact definitions on total run time and response. Two simulations were performed to analyze this model; a 4.9 m/s knee bolster impact and a 6.9 m/s lateral knee impact using LS-DYNA R6.1.1. The 40 ms knee bolster impact and lateral knee impact tests required 5 and 7 minutes to run, respectively on 4 cores. The original detailed M50 lower extremity model required 94 and 112 minutes to run the same boundary conditions, on the same hardware, representing a reduction in run time of on average 94%. A quantitative comparison was made by comparing the peak force of the impacts between the two models. This simplified leg model will become a component in a simplified full body model of the seated, 50th percentile male occupant. The significantly reduced run time will be valuable for parametric studies with a full body finite element model.

  11. Arsenic and selenium in microbial metabolism

    USGS Publications Warehouse

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

    2006-01-01

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

  12. Selenium toxicosis in three California sea lions (Zalophus californianus).

    PubMed

    Edwards, W C; Whitenack, D L; Alexander, J W; Solangi, M A

    1989-12-01

    Selenium poisoning occurs worldwide in nearly all domestic animals. Acute selenium poisoning is associated with feeding high levels or injecting excessive amounts of selenium and is usually fatal. The acute poisoning may cause gastrointestinal disturbance, muscle weakness, depression of the central nervous system, prostration and death (1-2). Chronic selenium poisoning in cattle, sheep and horses may result from the consumption of seleniferous plants over an extended period of time. Chronic selenium results in ataxia, incoordination, partial blindness, paralysis, loss of hair or wool, abnormal hoof growth and possibly abnormal changes in behavior (1). There is little information regarding the clinical signs and pathology of selenium toxicosis in marine mammals. Likewise, there is little information regarding normal tissue levels or toxicologically significant levels of selenium in these species. The results of these investigations in sea lions, based on clinical signs, pathologic findings and tissue levels of selenium, suggest subacute or chronic selenium poisoning was most likely from dietary fish high in selenium.

  13. Evaluation of selenium in dietary supplements using elemental speciation.

    PubMed

    Kubachka, Kevin M; Hanley, Traci; Mantha, Madhavi; Wilson, Robert A; Falconer, Travis M; Kassa, Zena; Oliveira, Aline; Landero, Julio; Caruso, Joseph

    2017-03-01

    Selenium-enriched dietary supplements containing various selenium compounds are readily available to consumers. To ensure proper selenium intake and consumer confidence, these dietary supplements must be safe and have accurate label claims. Varying properties among selenium species requires information beyond total selenium concentration to fully evaluate health risk/benefits A LC-ICP-MS method was developed and multiple extraction methods were implemented for targeted analysis of common "seleno-amino acids" and related oxidation products, selenate, selenite, and other species relatable to the quality and/or accuracy of the labeled selenium ingredients. Ultimately, a heated water extraction was applied to recover selenium species from non-selenized yeast supplements in capsule, tablet, and liquid forms. For selenized yeast supplements, inorganic selenium was monitored as a means of assessing selenium yeast quality. A variety of commercially available selenium supplements were evaluated and discrepancies between labeled ingredients and detected species were noted.

  14. Control over response number by a targeted percentile schedule: reinforcement loss and the acute effects of d-amphetamine.

    PubMed Central

    Galbicka, G; Fowler, K P; Ritch, Z J

    1991-01-01

    Two fixed-consecutive-number-like procedures were used to examine effects of acute d-amphetamine administration on control over response number. In both procedures, rats were required to press the left lever at least once and then press the right lever to complete a trial. The consecutive left-lever presses on each trial comprised a "run." Under the targeted percentile schedule, reinforcement was provided if the current run length was closer to the target length (16) than half of the most recent 24 runs. This differentially reinforced run length while holding reinforcement probability constant at .5. A second group acquired the differentiation under the targeted percentile schedule, but were then shifted to a procedure that yoked reinforcement probability by subject and run length to that obtained under the targeted percentile schedule. The two procedures generated practically identical control run lengths, response rates, reinforcement probabilities, and reinforcement rates. Administration of d-amphetamine disrupted percentile responding to a greater degree than yoked control responding. This disruption decreased reinforcement frequency less in the former than the latter procedure. The similar baseline responding under these two procedures suggests that this difference in sensitivity was due to behavioral adjustments to drug prompted by reduction of reinforcement density in the yoked control but not the percentile schedule. These adjustments attenuate the drug's effects under the former, but not the latter, procedure. PMID:1955813

  15. Selenium: a brief review and a case report of selenium responsive cardiomyopathy

    PubMed Central

    2013-01-01

    Background The authors review the role of selenium and highlight possible low selenium levels in soil that may result in deficient states in Saudi Arabia. Case presentation The authors report a case of selenium-responsive cardiomyopathy in a 15-month old Saudi Arabian boy. This case of selenium deficiency causing dilated cardiomyopathy is presented with failure to thrive, prolonged fever and respiratory distress. The investigations revealed selenium deficiency. Selenium supplementation along with anti-failure therapy [Furosimide, Captopril] was administered for 6 months. Following therapy the cardiac function, hair, skin and the general health of the patient improved significantly. Conclusion The patient with dilated cardiomyopathy of unknown etiology, not responding to usual medication may be deficient in selenium. Serum selenium measurements should be included in the diagnostic work-up to ensure early detection and treatment of the disease. The selenium level in the Saudi population needs be determined. Vulnerable populations have to undergo regular selenium measurements and supplementation if indicated. Dependence on processed foods suggests that the Saudi population fortify themselves with nutrient and micronutrient supplements in accordance to the RDA. PMID:23530936

  16. 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.

  17. [Health resort "Marfinskiy" celebrates the 85th anniversary].

    PubMed

    Titov, I G; Kozyrev, P V

    2015-05-01

    The history of foundation of the military health resort Marfinskiyo is represented in the article. Particular attention is paid to the organization and content of medical diagnostic work sanatorium, modern methods of treatment in a sanatorium.

  18. Selenium in oncology: from chemistry to clinics.

    PubMed

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

    2009-10-12

    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

  19. Selenium in Cattle: A Review.

    PubMed

    Mehdi, Youcef; Dufrasne, Isabelle

    2016-04-23

    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.

  20. 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.

  1. Selenium in human male reproductive organs.

    PubMed

    Oldereid, N B; Thomassen, Y; Purvis, K

    1998-08-01

    The objective of the study was to obtain information on the concentration and distribution of selenium throughout the human male reproductive tract. Material was removed at autopsy from 41 men who had died suddenly and unexpectedly. Semen samples were also provided from 184 men attending an andrology clinic for fertility investigation and from 32 healthy volunteers. Significant positive correlations in the selenium concentration were demonstrated between the different reproductive organs, the testis having the highest concentrations. No correlation was found between the concentration of selenium in the genital organs and liver, kidney or blood, suggesting that its uptake and/or biochemical activity in the reproductive organs may be controlled by similar mechanisms not shared by the other organs. No significant age-dependent changes could be detected in tissue selenium concentrations. In a group of men under fertility investigation, a significant positive correlation was obtained between seminal plasma concentrations of selenium and concentrations of spermatozoa in the same ejaculate. A significant positive correlation between concentrations of zinc and selenium in the same ejaculates indicated that selenium may arise largely from the prostate gland.

  2. 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.

  3. In Situ Immobilization of Selenium in Sediment

    SciTech Connect

    Moore, Robert C.; Stewart, Thomas Austin

    2014-09-01

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

  4. Parental Activity as Influence on Children`s BMI Percentiles and Physical Activity.

    PubMed

    Erkelenz, Nanette; Kobel, Susanne; Kettner, Sarah; Drenowatz, Clemens; Steinacker, Jürgen M

    2014-09-01

    Parents play a crucial role in the development of their children's lifestyle and health behaviour. This study aims to examine associations between parental physical activity (PA) and children's BMI percentiles (BMIPCT), moderate to vigorous PA (MVPA) as well as participation in organised sports. Height and body weight was measured in 1615 in German children (7.1 ± 0.6 years, 50.3% male) and converted to BMIPCT. Parental BMI was calculated based on self-reported height and body weight. Children's MVPA and sports participation as well as parental PA were assessed via parental questionnaire. Analysis of covariance (ANCOVA), controlling for age and family income was used to examine the association between parental and children's PA levels as well as BMIPCT. 39.7% of the parents classified themselves as physically active and 8.3% of children were classified as overweight or obese. Lower BMIPCT were observed with both parents being physically active (44.5 ± 26.3 vs. 50.2 ± 26.9 and 52.0 ± 28.4, respectively). There was no association between parental and children's PA levels but children with at least one active parent displayed a higher participation in organised sports (102.0 ± 96.6 and 117.7 ± 123.6 vs. 73.7 ± 100.0, respectively). Children of active parents were less likely to be overweight and obese. The lack of association between subjectively assessed parental PA and child MVPA suggests that parental support for PA in children is more important than parents being a role model. More active parents, however, may be more likely to facilitate participation in organised sports. These results underline the importance of the inclusion of parents in health promotion and obesity prevention programmes in children. Key pointsA higher prevalence of overweight or obese children was found with inactive parents.Children's BMI percentiles were lower if both parents were physically active compared to children whose parents were both inactive or only had one physically

  5. Parental Activity as Influence on Childrenˋs BMI Percentiles and Physical Activity

    PubMed Central

    Erkelenz, Nanette; Kobel, Susanne; Kettner, Sarah; Drenowatz, Clemens; Steinacker, Jürgen M.

    2014-01-01

    Parents play a crucial role in the development of their children’s lifestyle and health behaviour. This study aims to examine associations between parental physical activity (PA) and children’s BMI percentiles (BMIPCT), moderate to vigorous PA (MVPA) as well as participation in organised sports. Height and body weight was measured in 1615 in German children (7.1 ± 0.6 years, 50.3% male) and converted to BMIPCT. Parental BMI was calculated based on self-reported height and body weight. Children’s MVPA and sports participation as well as parental PA were assessed via parental questionnaire. Analysis of covariance (ANCOVA), controlling for age and family income was used to examine the association between parental and children’s PA levels as well as BMIPCT. 39.7% of the parents classified themselves as physically active and 8.3% of children were classified as overweight or obese. Lower BMIPCT were observed with both parents being physically active (44.5 ± 26.3 vs. 50.2 ± 26.9 and 52.0 ± 28.4, respectively). There was no association between parental and children’s PA levels but children with at least one active parent displayed a higher participation in organised sports (102.0 ± 96.6 and 117.7 ± 123.6 vs. 73.7 ± 100.0, respectively). Children of active parents were less likely to be overweight and obese. The lack of association between subjectively assessed parental PA and child MVPA suggests that parental support for PA in children is more important than parents being a role model. More active parents, however, may be more likely to facilitate participation in organised sports. These results underline the importance of the inclusion of parents in health promotion and obesity prevention programmes in children. Key points A higher prevalence of overweight or obese children was found with inactive parents. Children’s BMI percentiles were lower if both parents were physically active compared to children whose parents were both inactive or only had one

  6. 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.

  7. 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.

  8. 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.

  9. Red selenium nanoparticles and gray selenium nanorods as antibacterial coatings for PEEK medical devices.

    PubMed

    Wang, Qi; Mejía Jaramillo, Alejandra; Pavon, Juan J; Webster, Thomas J

    2016-10-01

    Bacterial infections are commonly found on various poly(ether ether ketone) (PEEK) medical devices (such as orthopedic instruments, spinal fusion devices, and segments in dialysis equipment), and thus, there is a significant need for introducing antibacterial properties to such materials. The objective of this in vitro study was to introduce antibacterial properties to PEEK medical devices by coating them with nanosized selenium. In this study, red selenium (an elemental form of selenium) nanoparticles were coated on PEEK medical devices through a quick precipitation method. Furthermore, with heat treatment at 100°C for 6 days, red selenium nanoparticles were transferred into gray selenium nanorods on the PEEK surfaces. Bacteria test results showed that both red and gray selenium-coated PEEK medical devices significantly inhibited the growth of Pseudomonas aeruginosa compared with uncoated PEEK after either 1, 2, or 3 days. Red selenium nanoparticle-coated PEEK showed less bacteria growth on its surface than gray selenium nanorod-coated PEEK after 3 days. This study demonstrated that red, and to a lesser extent gray, nanosized selenium could be used as potential antibacterial coatings to prevent bacteria function on PEEK medical devices. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1352-1358, 2016.

  10. 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.

  11. Pregnancy prognosis in women with anti-Müllerian hormone below the tenth percentile.

    PubMed

    Koshy, Aby Kottal; Gudi, Anil; Shah, Amit; Bhide, Priya; Timms, Peter; Homburg, Roy

    2013-07-01

    Although serum anti-Müllerian hormone (AMH) is considered a good predictor of ovarian response during in vitro fertilisation (IVF), pregnancies have been reported with low values, questioning its usefulness as a predictor of treatment outcome. A retrospective study was therefore carried out to assess the IVF treatment outcomes in women with AMH below the tenth percentile of the study population. In all, 134 women with AMH ≤ 3 pmol/L underwent 180 IVF cycles. The mean age at the time of treatment was 37 ± 5 years. Fifty-three (29.4%) cycles were abandoned because of poor response to gonadotrophins, 12 (6.7%) due to absence of eggs at oocyte retrieval and 18 (10%) due to fertilisation failure. Seven (3.8%) had a biochemical pregnancy, 4 (2.2%) had a missed miscarriage and 8 (4.4%) had a live birth. When stratified by age, women older than 42 years had less number of follicles (p < 0.05) and those older than 39 years had less oocytes (p < 0.01) compared to those 35 years and younger. Live births declined with increasing age, when age was assessed as a continuous variable (p = 0.023). Women with low AMH levels have a high probability of treatment cancellation, failure to proceed to embryo transfer and a low chance of achieving a viable pregnancy.

  12. Percentile benchmarks in patients with rheumatoid arthritis: Health Assessment Questionnaire as a quality indicator (QI)

    PubMed Central

    Krishnan, Eswar; Tugwell, Peter; Fries, James F

    2004-01-01

    Physicians are in need of a simple objective, standardized tool to compare their patients with rheumatoid arthritis, as a group and individually, with national standards. The Disability Index of the Health Assessment Questionnaire (HAQ-DI) is a simple, robust tool that can fulfill these needs. However, use of this tool as a quality indicator (QI) is hampered by the unavailability of national reference values or benchmarks based on large, multicentric, heterogenous longitudinal patient cohorts. We utilized the 20-year longitudinal prospective data from 11 data banks of Arthritis Rheumatism and Aging Medical Information to calculate reference values for HAQ-DI. Overall, 6436 patients with rheumatoid arthritis were longitudinally followed for 32,324 person-years over the 20 years from 1981 to 2000. There were 64,647 HAQ-DI measurements, with an average of 19 measurements per person. Overall, 75% of patients were women and 89% were Caucasian; the median baseline age was 58.4 years and the median baseline HAQ-DI was 1.13. Few patients were treated with biologics. The HAQ-DI values had a Gaussian distribution except for the approximately 10% of observations showing no disability. Percentile benchmarks allow disability outcomes to be compared and contrasted between different patient populations. Reference values for the HAQ-DI, presented here numerically and graphically, can be used in clinical practice as a QI measure to track functional disability outcomes and to measure response to therapy, and by arthritis patients in self-management programs. PMID:15535828

  13. 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...

  14. 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.

  15. 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

  16. 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…

  17. Comparisons of infant mortality using a percentile-based method of standardization for birthweight or gestational age.

    PubMed

    Hertz-Picciotto, I; Din-Dzietham, R

    1998-01-01

    Comparisons of infant, perinatal, or neonatal mortality across populations with different birthweight or gestational age distributions are problematic. Summary measures with adjustment for birthweight or gestational age frequently are invalid or lack interpretability. We propose a percentile-based method of standardization for comparing infant, perinatal, or neonatal mortality across populations that have different distributions of birthweight and/or gestational age. The underlying concept is a simple one: comparable health for two population groups will be expressed as equal rates of disease or mortality at equal quantiles in the two distributions of birthweight or gestational age. We describe this method mathematically and present an example comparing mortality rates for African-American vs European-American infants in North Carolina. When gestational age is transformed to its rank, the well-known crossover in mortality rates, in which preterm African-American infants die at lower rates but term infants at higher rates, disappears: African-Americans show higher mortality rates at any percentile of gestational age. With homogeneous mortality rate ratios, a summary statistic becomes meaningful. We also demonstrate adjustment for percentile-transformed gestational age or birthweight in multiple logistic regression models. Percentile standardization is easily implemented, has advantages over other methods of internal standardization such as that of Wilcox and Russell, and communicates an intuitive public health-based concept of equality of mortality across populations.

  18. 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…

  19. Development of THOR-FLx: A Biofidelic Lower Extremity for Use with 5th Percentile Female Crash Test Dummies.

    PubMed

    Shams, Tariq; Beach, David; Huang, Tsai-Jeon; Rangarajan, N; Haffner, Mark

    2002-11-01

    A new lower leg/ankle/foot system has been designed and fabricated to assess the potential for lower limb injuries to small females in the automotive crash environment. The new lower extremity can be retrofitted at present to the distal femur of the 5th percentile female Hybrid III dummy. Future plans are for integration of this design into the 5th percentile female THOR dummy now under development. The anthropometry of the lower leg and foot is based mainly on data developed by Robbins for the 5th percentile female, while the biomechanical response requirements are based upon scaling of 50th percentile male THOR-Lx responses. The design consists of the knee, tibia, ankle joints, foot, a representation of the Achilles tendon, and associated flesh/skins. The new lower extremity, known as THOR-FLx, is designed to be biofidelic under dynamic axial loading of the tibia, static and dynamic dorsiflexion, static plantarflexion and inversion/eversion. Instrumentation includes accelerometers, load cells, and rotary potentiometers to capture relevant kinematic and dynamic information from the foot and tibia. This paper will describe the performance requirements for THOR-FLx, the methodology used in its' development, results of component tests, and the biofidelity tests conducted on the full assembly.

  20. Arsenic-Selenium And Mercury-Selenium Bonds in Biology

    SciTech Connect

    Gailer, Jurgen; /Calgary U.

    2007-07-10

    When rabbits are simultaneous injected with arsenite and selenite or mercuric chloride and selenite, compounds with As-Se and Hg-Se bonds are formed in the bloodstream. The combined application of liquid chromatography-inductively coupled plasma atomic emission spectrometry (ICP-AES) and X-ray absorption spectroscopy (XAS) has revealed the molecular structure of these toxicologically important compounds and provided insight into their mechanism of formation. The glutathione-driven formation of these compounds in the bloodstream fundamentally links the metabolism of the environmental pollutants mercuric mercury and arsenite with that of the essential ultratrace element selenium, which establishes a feasible mechanism by which the chronic low-level exposure of various human populations to these toxic metals and metalloid compounds is linked to human diseases, including cancer and neurodegenerative diseases.

  1. 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.

  2. Studies on selenium in top athletes.

    PubMed

    Drâgan, I; Ploeşteanu, E; Cristea, E; Mohora, M; Dinu, V; Troescu, V S

    1988-01-01

    The authors performed a controlled trial in 18 top athletes (9 weight lifters and 9 rowers, girls) in order to make evident some chronic and acute effects (antioxidant) of selenium. Nonprotein--SH (essential glutathione), lipid peroxides (MDA-malondialdehyde), glucose-6-phosphate dehydrogenases (G-6-PDH) and fructose-1,6-diphosphate aldolase in serum, have been recorded initially on basal conditions, after 3 weeks of treatment (100 micrograms/day selenium or placebo) and again after 3 weeks of treatment, also on basal conditions, when crossing over the groups (between a free interval of 10 days). In another trial we registered these parameters on basal conditions and after two hours of hard training accompanied by a per oral administration of 150 micrograms selenium (respectively placebo). The results show significant changes under selenium treatment of the peroxides, G-6-PDH and light changes, not significant of the nonprotein--SH, changes which could suggest an antioxidant effect of this element.

  3. 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.

  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. 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

  6. Waist-to-Height Ratio Percentiles and Cutoffs for Obesity: A Cross-sectional Study in Brazilian Adolescents

    PubMed Central

    Zanetti Passos, Maria Aparecida; dos Santos, Luana Caroline; da Costa Machado, Helymar; Fisberg, Mauro

    2014-01-01

    ABSTRACT This study aimed to describe the distribution of waist-to-height ratio (WHtR) percentiles and cutoffs for obesity in Brazilian adolescents. A cross-sectional study including adolescents aged 10 to 15 years was conducted in the city of São Paulo, Brazil; anthropometric measurements (weight, height, and waist-circumference) were taken, and WHtRs were calculated and then divided into percentiles derived by using Least Median of Squares (LMS) regression. The receiver operating characteristic (ROC) curve was used in determining cutoffs for obesity (BMI ≥97th percentile) and Mann-Whitney and Kruskal-Wallis tests were used for comparing variables. The study included 8,019 adolescents from 43 schools, of whom 54.5% were female, and 74.8% attended public schools. Boys had higher mean WHtR than girls (0.45±0.06 vs 0.44±0.05; p=0.002) and higher WHtR at the 95th percentile (0.56 vs 0.54; p<0.05). The WHtR cutoffs according to the WHO criteria ranged from 0.467 to 0.506 and 0.463 to 0.496 among girls and boys respectively, with high sensitivity (82.8-95%) and specificity (84-95.5%). The WHtR was significantly associated with body adiposity measured by BMI. Its age-specific percentiles and cutoffs may be used as additional surrogate markers of central obesity and its co-morbidities. PMID:25395904

  7. Zinc, copper and selenium in reproduction.

    PubMed

    Bedwal, R S; Bahuguna, A

    1994-07-15

    Of the nine biological trace elements, zinc, copper and selenium are important in reproduction in males and females. Zinc content is high in the adult testis, and the prostate has a higher concentration of zinc than any other organ of the body. Zinc deficiency first impairs angiotensin converting enzyme (ACE) activity, and this in turn leads to depletion of testosterone and inhibition of spermatogenesis. Defects in spermatozoa are frequently observed in the zinc-deficient rat. Zinc is thought to help to extend the functional life span of the ejaculated spermatozoa. Zinc deficiency in the female can lead to such problems as impaired synthesis/secretion of (FSH) and (LH), abnormal ovarian development, disruption of the estrous cycle, frequent abortion, a prolonged gestation period, teratogenicity, stillbirths, difficulty in parturition, pre-eclampsia, toxemia and low birth weights of infants. The level of testosterone in the male has been suggested to play a role in the severity of copper deficiency. Copper-deficient female rats are protected against mortality due to copper deficiency, and the protection has been suggested to be provided by estrogens, since estrogens alter the subcellular distribution of copper in the liver and increase plasma copper levels by inducing ceruloplasmin synthesis. The selenium content of male gonads increases during pubertal maturation. Selenium is localized in the mitochondrial capsule protein (MCP) of the midpiece. Maximal incorporation in MCP occurs at steps 7 and 12 of spermatogenesis and uptake decreases by step 15. Selenium deficiency in females results in infertility, abortions and retention of the placenta. The newborns from a selenium-deficient mother suffer from muscular weakness, but the concentration of selenium during pregnancy does not have any effect on the weight of the baby or length of pregnancy. The selenium requirements of a pregnant and lactating mother are increased as a result of selenium transport to the fetus via

  8. 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.

  9. 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.

  10. 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.

  11. 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).

  12. Removal of trapped charge in selenium detectors

    NASA Astrophysics Data System (ADS)

    Lee, Denny; Maidment, Andrew D. A.

    2010-04-01

    Flat panel selenium detectors (1) have been commercially available since 1998 (2). The MTF of these detectors can approach the theoretical SINC function for the pixel size (3). Detectors can be designed with selenium thickness suitable for absorption of the range of x-ray energy for the modality (4, 5). For higher energy x rays, the thickness of the selenium layer can be increased without greatly degrading the spatial resolution. The non-spreading nature of the signal allows the detector to detect very weak x-ray signal in the vicinity of strong signal. Selenium detectors can therefore be designed to produce very high dynamic range images when needed. However, as a photo-conducting material, selenium also comes with some less than ideal properties. For example, charge trapping, long settling time for with bias electric field, and interface charge injection (6). These adverse properties must be included in detector design for optimal performance in each application. This paper describes a novel method for interfacial charge removal using lateral conductivity of selenium.

  13. 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.

  14. Dietary Selenium and Human Health

    PubMed Central

    Schomburg, Lutz

    2016-01-01

    Next year (2017), the micronutrient Selenium (Se) is celebrating its birthday—i.e., 200 years after first being identified by the Swedish chemist Jöns Jakob Berzelius. Despite its impressive age, research into the functions of this essential trace element is very alive and reaching out for new horizons. This special issue presents some recent fascinating, exciting, and promising developments in Se research in the form of eight original contributions and seven review articles. Collectively, aspects of Se supply, biochemical, physiological, and chemotherapeutic effects, and geobiological interactions are covered by leading scientists in the areas of nutritional, basic, and clinical research. It is obvious from the contributions that the bicentennial anniversary will celebrate a micronutrient still in its infancy with respect to being understood in terms of its biomedical importance. PMID:28042811

  15. 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

  16. Updates on clinical studies of selenium supplementation in radiotherapy.

    PubMed

    Puspitasari, Irma M; Abdulah, Rizky; Yamazaki, Chiho; Kameo, Satomi; Nakano, Takashi; Koyama, Hiroshi

    2014-05-29

    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.

  17. Natural selenium-rich feeds manage selenium deficiency in Oregon sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A natural selenium-rich feed product (SePR) was developed by the USDA, ARS, U.S. Sheep Experiment Station for the purposes of enhancing the long-term selenium status of grazing livestock. In cooperation with Intermountain Farmers Association (Salt Lake City, UT), a bulk amount of SePR was manufactur...

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

    SciTech Connect

    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.

  19. 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 475 nm. A specific surface area of 30.5 m(2) g(-1) is observed for selenium nanoparticles. The selenium nanoparticles hold mesopores in the range of 1.39 nm, 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 21.98 F g(-1) with 91% electrochemical stability.

  20. Vitamin E, Selenium Don't Cut Colon Cancer Risk

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_162669.html Vitamin E, Selenium Don't Cut Colon Cancer Risk: ... 2016 WEDNESDAY, Dec. 21, 2016 (HealthDay News) -- Taking vitamin E and selenium does not appear to reduce ...

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

    PubMed

    Yan, Lin; Johnson, LuAnn K

    2011-06-08

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

  2. 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.

  3. Molecular targets of selenium in prostate cancer prevention (Review).

    PubMed

    Abdulah, Rizky; Kobayashi, Kenji; Yamazaki, Chiho; Koyama, Hiroshi

    2011-08-01

    Prostate cancer is one of the leading causes of cancer-related deaths among males. Although use of the micro-nutrient selenium in prostate cancer clinical trials is limited, the outcomes indicate that selenium is a promising treatment. Furthermore, selenium inhibits prostate cancer through multiple mechanisms, and it is beneficial in controlling the development of this disease. This review highlights the latest epidemiological and biomolecular research on selenium in prostate cancer, as well as its prospects for future clinical use.

  4. 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.

  5. 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

  6. Selenium deficiency, reversible cardiomyopathy and short-term intravenous feeding.

    PubMed Central

    Levy, J. B.; Jones, H. W.; Gordon, A. C.

    1994-01-01

    We report the case of a patient with Crohn's disease receiving short-term postoperative parenteral nutrition supplemented with trace elements who nevertheless became selenium deficient with evidence of a cardiomyopathy. This was fully reversible with oral selenium supplementation. Current parenteral feeding regimes may not contain enough selenium for malnourished patients. PMID:8183763

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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,...

  13. 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,...

  14. 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,...

  15. 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,...

  16. 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,...

  17. Toxicity of organic and inorganic selenium to mallard ducklings

    USGS Publications Warehouse

    Heinz, G.H.; Hoffman, D.J.; Gold, L.G.

    1988-01-01

    The toxicity of selenomethionine and sodium selenite to mallard ducklings (Anas platyrhynchos) was measured by feeding each form from hatching to six weeks of age at dietary concentrations of 0, 10, 20, 40, and 80 ppm selenium. At 80 ppm selenium, sodium selenite caused 97.5% mortality by six weeks and selenomethionine caused 100% mortality. At 40 ppm, these two forms of selenium caused 25 and 12.5% mortality. No mortality occurred at 10 or 20 ppm. Diets containing 20, 40, or 80 ppm selenium in both forms caused decreases in food consumption and growth. The only statistically significant effect of 10 ppm selenium was with sodium selenite, which resulted in larger livers than controls. Selenomethionine was more readily stored in the liver than sodium selenite at levels above 10 ppm selenium in the diet. Based on comparisons of residues of selenium in livers of surviving and dead ducklings, concentrations in the liver were not diagnostic of death due to selenium poisoning. Because both forms of selenium resulted in severe reductions in food consumption, selenium-induced starvation may have been related to duckling mortality. It was not clear whether either form of selenium at 10 ppm in the diet resulted in a leveling off of selenium concentrations in the liver within six weeks.

  18. 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…

  19. Dual functional selenium-substituted hydroxyapatite

    PubMed Central

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

    2012-01-01

    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

  20. Serum selenium levels and prostate cancer risk

    PubMed Central

    Cui, Zhigang; Liu, Dezhong; Liu, Chun; Liu, Gang

    2017-01-01

    Abstract Some observational studies have shown that elevated serum selenium levels are associated with reduced prostate cancer risk; however, not all published studies support these results. A literature search of PubMed, Embase, Medline, and the Cochrane Library up until September 2016 identified 17 studies suitable for further investigation. A meta-analysis was conducted on these studies to investigate the association between serum selenium levels and subsequent prostate cancer risk. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the overall OR of prostate cancer for the highest versus the lowest levels of serum selenium. We found a pooled OR (95% CI) of 0.76 (0.64, 0.91; P < 0.05). In subgroup analysis, an inverse association between serum selenium levels and prostate cancer risk was found in each of case–control studies, current and former smokers, high-grade cancer cases, advanced cancer cases, and different populations. Such correlations were not found for subgroups containing each of cohort studies, nonsmokers, low-grade cancer cases, and early stage cancer cases. In conclusion, our study suggests an inverse relationship between serum selenium levels and prostate cancer risk. However, further cohort studies and randomized control trials based on non-Western populations are required. PMID:28151881

  1. [Pharmaconutrition with parenteral selenium in sepsis].

    PubMed

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

    2014-04-01

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

  2. Assessment of selenium effects in lotic ecosystems.

    PubMed

    Hamilton, S J; Palace, V P

    2001-11-01

    The selenium literature has grown substantially in recent years to encompass new information in a variety of areas. Correspondingly, several different approaches to establishing a new water quality criterion for selenium have been proposed since establishment of the national water quality criterion in 1987. Diverging viewpoints and interpretations of the selenium literature have lead to opposing perspectives on issues such as establishing a national criterion based on a sediment-based model, using hydrologic units to set criteria for stream reaches, and applying lentic-derived effects to lotic environments. This Commentary presents information on the lotic verse lentic controversy. Recently, an article was published that concluded that no adverse effects were occurring in a cutthroat trout population in a coldwater river with elevated selenium concentrations (C. J. Kennedy, L. E. McDonald, R. Loveridge, and M. M. Strosher, 2000, Arch. Environ. Contam. Toxicol. 39, 46-52). This article has added to the controversy rather than provided further insight into selenium toxicology. Information, or rather missing information, in the article has been critically reviewed and problems in the interpretations are discussed.

  3. Assessment of selenium effects in lotic ecosystems

    USGS Publications Warehouse

    Hamilton, Steven J.; Palace, Vince

    2001-01-01

    The selenium literature has grown substantially in recent years to encompass new information in a variety of areas. Correspondingly, several different approaches to establishing a new water quality criterion for selenium have been proposed since establishment of the national water quality criterion in 1987. Diverging viewpoints and interpretations of the selenium literature have lead to opposing perspectives on issues such as establishing a national criterion based on a sediment-based model, using hydrologic units to set criteria for stream reaches, and applying lentic-derived effects to lotic environments. This Commentary presents information on the lotic verse lentic controversy. Recently, an article was published that concluded that no adverse effects were occurring in a cutthroat trout population in a coldwater river with elevated selenium concentrations (C. J. Kennedy, L. E. McDonald, R. Loveridge, and M. M. Strosher, 2000, Arch. Environ. Contam. Toxicol. 39, 46–52). This article has added to the controversy rather than provided further insight into selenium toxicology. Information, or rather missing information, in the article has been critically reviewed and problems in the interpretations are discussed.

  4. 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

  5. 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 ...

  6. Improved selenium recovery from tissue with modified sample decomposition

    USGS Publications Warehouse

    Brumbaugh, W. G.; Walther, M.J.

    1991-01-01

    The present paper describes a simple modification of a recently reported decomposition method for determination of selenium in biological tissue by hydride generation atomic absorption. The modified method yielded slightly higher selenium recoveries (3-4%) for selected reference tissues and fish tissue spiked with selenomethionine. Radiotracer experiments indicated that the addition of a small volume of hydrochloric acid to the wet digestate mixture reduced slight losses of selenium as the sample initially went to dryness before ashing. With the modified method, selenium spiked as selenomethionine behaved more like the selenium in reference tissues than did the inorganic spike forms when this digestion modification was used.

  7. 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.

  8. Selenium and selenocysteine: roles in cancer, health, and development.

    PubMed

    Hatfield, Dolph L; Tsuji, Petra A; Carlson, Bradley A; Gladyshev, Vadim N

    2014-03-01

    The many biological and biomedical effects of selenium are relatively unknown outside the selenium field. This fascinating element, initially described as a toxin, was subsequently shown to be essential for health and development. By the mid-1990s selenium emerged as one of the most promising cancer chemopreventive agents, but subsequent human clinical trials yielded contradictory results. However, basic research on selenium continued to move at a rapid pace, elucidating its many roles in health, development, and in cancer prevention and promotion. Dietary selenium acts principally through selenoproteins, most of which are oxidoreductases involved in diverse cellular functions.

  9. 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.

  10. 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.

  11. [The importance of selenium in Hashimoto's disease].

    PubMed

    Zagrodzki, Paweł; Kryczyk, Jadwiga

    2014-09-12

    The aim of this study was to present the current state of knowledge on the role of selenium in the treatment of Hashimoto's disease. In recent years, the number of cases of autoimmune Hashimoto's thyroiditis - a chronic disease that usually leads to hypothyroidism - has increased. Most patients have elevated levels of anti-TPO antibodies. The presence of these antibodies has an effect on subsequent thyroid damage. So far we have not developed an effective, standard therapy of this disease. However, more attention is being paid to the relationship between supplementation of selenium deficiency and inhibition of production of anti-TPO antibodies in patients with Hashimoto's thyroiditis. Therefore, selenium supplementation may be an effective option in the treatment of this disease.

  12. Bioaccumulation and distribution of selenium in Enterococcus durans.

    PubMed

    Pieniz, Simone; Andreazza, Robson; Mann, Michele Bertoni; Camargo, Flávio; Brandelli, Adriano

    2017-03-01

    Selenium is an essential nutrient for all living organisms. Under appropriate conditions lactic acid bacteria (LAB) are capable for accumulating large amounts of trace elements, such as selenium, and incorporating them into organic compounds. In this study, the capacity of selenium bioaccumulation by Enterococcus durans LAB18s was evaluated. The distribution of organic selenium in selenium-enriched E. durans LAB18s biomass was analyzed, and the highest percentage of organic selenium was found in the fraction of total protein, followed by the fractions of polysaccharides and nucleic acids. When the protein fraction was obtained by different extractions (water, NaCl, ethanol and NaOH) it was demonstrated that alkali-soluble protein showed the higher Selenium content. Analysis of protein fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that selenium was present in the proteins ranging from 23 to 100kDa. The cells were analyzed by scanning electron microscopy (SEM); scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) and transmission electron microscopy (TEM). SEM, TEM and SEM/EDS showed the morphology, the selenium particles bioaccumulated into and on the cells and the amounts of selenium present into the cells, respectively. Thus, the isolate E. durans LAB18s can be a promising probiotic to be used as selenium-enriched biomass in feed trials.

  13. Selenium and Thyroid Disease: From Pathophysiology to Treatment

    PubMed Central

    Ventura, Mara; Carrilho, Francisco

    2017-01-01

    Introduction. Selenium is a micronutrient embedded in several proteins. In adults, the thyroid is the organ with the highest amount of selenium per gram of tissue. Selenium levels in the body depend on the characteristics of the population and its diet, geographic area, and soil composition. In the thyroid, selenium is required for the antioxidant function and for the metabolism of thyroid hormones. Methods. We performed a review of the literature on selenium's role in thyroid function using PubMed/MEDLINE. Results. Regarding thyroid pathology, selenium intake has been particularly associated with autoimmune disorders. The literature suggests that selenium supplementation of patients with autoimmune thyroiditis is associated with a reduction in antithyroperoxidase antibody levels, improved thyroid ultrasound features, and improved quality of life. Selenium supplementation in Graves' orbitopathy is associated with an improvement of quality of life and eye involvement, as well as delayed progression of ocular disorders. The organic form of selenium seems to be the preferable formulation for supplementation or treatment. Conclusion. Maintaining a physiological concentration of selenium is a prerequisite to prevent thyroid disease and preserve overall health. Supplementation with the organic form is more effective, and patients with autoimmune thyroiditis seem to have benefits in immunological mechanisms. Selenium supplementation proved to be clinically beneficial in patients with mild to moderate Graves' orbitopathy. PMID:28255299

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

    PubMed

    Balázs, Csaba; Rácz, Károly

    2013-10-13

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

  15. Reproduction of mallards following overwinter exposure to selenium

    USGS Publications Warehouse

    Heinz, G.H.; Fitzgerald, M.A.

    1993-01-01

    Forty pairs of mallards (Anas platyrhynchos) were fed 15 ppm selenium as selenomethionine for about 21 weeks during winter. Twenty pairs served as controls. At the end of 21 weeks, which coincided with the onset of the reproductive season, selenium treatment was ended. Four birds died while on selenium treatment. Treated females lost weight, and their egg-laying was delayed. Hatching success of some of the first eggs laid by selenium-treated females was lower than that of controls, and a few of these early eggs contained deformed embryos, but, after a period of about two weeks off the selenium-treated diet, reproductive success returned to a level comparable with that of controls. The return to normal reproductive success was the result of a corresponding decrease in selenium concentrations in eggs once selenium treatment ended.

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

    PubMed

    Muecke, Ralph; Micke, Oliver; Schomburg, Lutz; Kisters, Klaus; Buentzel, Jens; Huebner, Jutta; Kriz, Jan

    2014-12-16

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

  17. 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...

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

    PubMed

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

    2017-03-04

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

  19. Factors affecting the selenium intake of people in Transbaikalian Russia.

    PubMed

    Aro, A; Kumpulainen, J; Alfthan, G; Voshchenko, A V; Ivanov, V N

    1994-03-01

    The selenium concentration in foods grown and consumed and in plasma, red blood cells, and toenails of people living in the district of Chita in the transbaikalian part of Russia were studied in August 1991. Preliminary results from the area have suggested low selenium intakes and the possible occurrence of cardiomyopathy (Keshan disease) in the population. A low selenium concentration in foods grown locally was found: mean selenium concentration in wheat grains was 1, 5, and 28 micrograms/kg, respectively, in three villages studied, that of oats was between 3-6 micrograms/kg, and of cow's milk 10-27 micrograms/kg dry matter. The selenium concentration of bread was considerably higher, between 87-337 micrograms/kg dry wt, presumably because wheat imported from the US had been used for baking. Occasional samples of pork, beef, and mutton contained between 32-218 micrograms selenium/kg dry wt. Low selenium concentrations were observed in samples of soil and river water. The mean plasma selenium concentration of 52 persons was 1.02 mumol/L, including 33 children and 19 adult subjects. The selenium concentrations in red blood cells and toenails were 1.95 mumol/L and 0.61 mg/kg, respectively. No symptoms of heart disease caused by selenium deficiency were observed. It is concluded that the selenium status of people was fairly good thanks to the contribution to dietary intake of imported wheat with a high selenium content. As the selenium concentration was very low in foods grown in the area, the selenium intake of the population will be reduced to a very low level if only locally produced foods are consumed.

  20. 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.

  1. 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.

  2. The Outcome of Selenium and Vitamin E Cancer Prevention Trial (SELECT) reveals the need for better understanding of selenium biology.

    PubMed

    Hatfield, Dolph L; Gladyshev, Vadim N

    2009-02-01

    The recently completed Selenium and Vitamin E Cancer Prevention Trial (SELECT) was one of the largest human cancer prevention trials ever undertaken. Its purpose was to assess the role of selenium and vitamin E in prostate cancer prevention, but SELECT found no decline in prostate cancer. Comparison of this study to other clinical trials involving selenium and to the results of animal studies suggests that the source of the selenium supplement, L-selenomethionine, and the relatively high initial levels of selenium in the enrolled men may have contributed to this outcome. Further analysis of the clinical and animal data highlights the need for mechanistic studies to better understand selenium biology in order to target dietary selenium to appropriate subsets of the human population: those individuals most likely to benefit from this micronutrient.

  3. The Relationship between Selenium and T3 in Selenium Supplemented and Nonsupplemented Ewes and Their Lambs

    PubMed Central

    Hefnawy, Abd Elghany; Youssef, Seham; Aguilera, P. Villalobos; Rodríguez, C. Valverde; Pérez, J. L. Tórtora

    2014-01-01

    Twenty pregnant ewes were selected and classified into two groups. The first group received subcutaneous selenium supplementation (0.1 mg of sodium selenite/kg BW) at the 8th and 5th weeks before birth and 1st week after birth while the other was control group without selenium injection. Maternal plasma and serum samples were collected weekly from the 8th week before birth until the 8th week after birth and milk samples were taken from ewes weekly, while plasma and serum samples were collected at 48 hours, 1st, 2nd, 3rd, 5th, and 8th weeks after birth from the newborn lambs. Results demonstrated significant positive relationship between maternal plasma selenium and serum T3 in supplemented and control ewes (r = 0.69 to 0.72, P < 0.05). There was significant (P < 0.001) increase in T3 in supplemented ewes and their lambs until the 8th week after birth. There was positive relationship between milk, selenium concentration, and serum T3 in the newborn lambs of the supplemented group (r = 0.84, P < 0.01), while the relationship was negative in the control one (r = −0.89, P < 0.01). Muscular and thyroid pathological changes were independent of selenium supplementation. Selenium supplementation was important for maintaining T3 in ewes and newborn lambs until the 8th week after birth. PMID:24660087

  4. Selenium proteins in ovine tissues: III. Distribution of selenium and glutathione peroxidases in tissue cytosols.

    PubMed

    Black, R S; Tripp, M J; Whanger, P D; Weswig, P H

    1978-01-01

    Three 6 week-old lambs were injected with carrier-free selenium-75 as sodium selenite initially and again after 6 days. One lamb received no further injections whereas the other two received injections of either vitamin E or unlabeled Na2SeO3 when the first selenium-75 injection was given. Selected tissues were removed at autopsy 10 days after the first injection. The cytosol from homogenates of these tissues was subjected to gel chromatography, and the elution profiles determined for radioactivity, protein content, and glutathione peroxidase activity using either hydrogen peroxide or cumene hydroperoxide as substrates. The selenium-75 was found to be distributed mainly between 2 different MW peaks. The larger MW seleno-peak (90,000) possessed both glutathione:hydrogen peroxide oxidoreductase, and glutathione:cumene hydroperoxide oxidoreductase activities, but the smaller MW seleno-peak (about 10,000) possessed no glutathione peroxidase activity. A peak of about 60,000 daltons containing only glutathione:cumene hydroperoxide oxidoreductase activity and no selenium-75 was found primarily in the liver and kidney. Vitamin E had no effect on the elution profiles. Selenium status of the animal had only a minor effect on the selenium-75 distribution in the cytosol, but had a marked effect on the absolute amount of the label taken up by tissues.

  5. 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.

  6. 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...

  7. 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).

  8. 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.

  9. 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...

  10. Selenium, selenoproteins and human health: a review.

    PubMed

    Brown, K M; Arthur, J R

    2001-04-01

    Selenium is of fundamental importance to human health. It is an essential component of several major metabolic pathways, including thyroid hormone metabolism, antioxidant defence systems, and immune function. The decline in blood selenium concentration in the UK and other European Union countries has therefore several potential public health implications, particularly in relation to the chronic disease prevalence of the Western world such as cancer and cardiovascular disease. Ten years have elapsed since recommended dietary intakes of selenium were introduced on the basis of blood glutathione peroxidase activity. Since then 30 new selenoproteins have been identified, of which 15 have been purified to allow characterisation of their biological function. The long term health implications in relation to declining selenium intakes have not yet been thoroughly examined, yet the implicit importance of selenium to human health is recognised universally. Selenium is incorporated as selenocysteine at the active site of a wide range of selenoproteins. The four glutathione peroxidase enzymes (classical GPx1, gastrointestinal GPx2, plasma GPx3, phospholipid hydroperoxide GPx4)) which represent a major class of functionally important selenoproteins, were the first to be characterised. Thioredoxin reductase (TR) is a recently identified seleno-cysteine containing enzyme which catalyzes the NADPH dependent reduction of thioredoxin and therefore plays a regulatory role in its metabolic activity. Approximately 60% of Se in plasma is incorporated in selenoprotein P which contains 10 Se atoms per molecule as selenocysteine, and may serve as a transport protein for Se. However, selenoprotein-P is also expressed in many tissues which suggests that although it may facilitate whole body Se distribution, this may not be its sole function. A second major class of selenoproteins are the iodothyronine deiodinase enzymes which catalyse the 5'5-mono-deiodination of the prohormone thyroxine (T4

  11. Selenium and the thyroid gland: more good news for clinicians.

    PubMed

    Drutel, Anne; Archambeaud, Françoise; Caron, Philippe

    2013-02-01

    The thyroid is the organ with the highest selenium content per gram of tissue because it expresses specific selenoproteins. Since the discovery of myxoedematous cretinism and thyroid destruction following selenium repletion in iodine- and selenium-deficient children, data on links between thyroid metabolism and selenium have multiplied. Although very minor amounts of selenium appear sufficient for adequate activity of deiodinases, thus limiting the impact of its potential deficiency on synthesis of thyroid hormones, selenium status appears to have an impact on the development of thyroid pathologies. The value of selenium supplementation in autoimmune thyroid disorders has been emphasized. Most authors attribute the effect of supplementation on the immune system to the regulation of the production of reactive oxygen species and their metabolites. In patients with Hashimoto's disease and in pregnant women with anti-TPO antibodies, selenium supplementation decreases anti-thyroid antibody levels and improves the ultrasound structure of the thyroid gland. Although clinical applications still need to be defined for Hashimoto's disease, they are very interesting for pregnant women given that supplementation significantly decreases the percentage of postpartum thyroiditis and definitive hypothyroidism. In Graves' disease, selenium supplementation results in euthyroidism being achieved more rapidly and appears to have a beneficial effect on mild inflammatory orbitopathy. A risk of diabetes has been reported following long-term selenium supplementation, but few data are available on the side effects associated with such supplementation and further studies are required.

  12. Review - Selenium - Its metabolism and relation to exercise.

    PubMed

    Baltaci, Abdulkerim Kasim; Mogulkoc, Rasim; Akil, Mustafa; Bicer, Mursel

    2016-09-01

    Selenium (Se), which is commonly found in nature, is one of the essential trace elements necessary for the normal development of human and animal organisms. Selenium was first defined in 1818 by the Swedish chemist Berzelius in sulfuric acid residues. At the end of 1960s, the role of selenium in human health began to attract attention and human diseases that resembled animal diseases responding to selenium was started to be investigated. Selenium, which is highly important for human health, is necessary for a variety of metabolic processes, including thyroid hormone metabolism, protection against oxidative stress and immunity functions. Selenium is a molecule that activates glutathione peroxidase, and thus, it is involved in the antioxidant mechanisms that prevent oxidant damage. Exhaustive physical exercise is known to cause oxidant damage, probably by promoting free radical production in many tissues, including muscle, liver, heart and lungs in animals. The increase in oxidative stress during exercise and recognition of selenium's stimulation of antioxidant activity inevitably suggest a relation between selenium and exercise. The present review aims to provide information on selenium metabolism and the relation between selenium and exercise.

  13. 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

  14. 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.

  15. 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.

  16. Electrochemical cell utilizing selenium as an electrode-reactant

    SciTech Connect

    Virkar, A.V.; Miller, G.R.; Rasmussen, J.R.

    1990-01-23

    This patent describes an electrochemical cell. It comprises: an anolyte containing substantially a molten alkali metal; a solid beta-alumina electrolyte possessing mobile alkali metal ions of the same alkali metal as is present in the anolyte; and a catholyte comprising a mixture of molten selenium and molten sulfur in a molar ration of about 3:1 to about 30:1 selenium to sulfur, wherein at least a portion of the selenium and sulfur is present in elemental form.

  17. 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.

  18. 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...

  19. [Studies on the assimilation of inorganic selenium by yeast].

    PubMed

    Xie, L; Ouyang, Z; Xie, X

    1990-02-01

    In the process of assimilation of inorganic selenium by yeast to the organic-selenium, some rules on the relation of the kinds of culture medium, concentration of sodium selenite and methionine to the total selenium and selenomethionine content in the yeast formed have been found; and a new, accurate procedure--modified acid hydrolysis-ion exchange chromatography for determining the content of seleno-amino acid in biological materials has been established.

  20. Erythrocyte selenium and breast cancer risk: brief reports

    SciTech Connect

    Meyer, F.; Verreault, R.

    1987-05-01

    Animal experiments and ecologic studies suggest that low dietary selenium intake is associated with an increased risk of some types of cancer. However, studies assessing the relation of indicators of selenium intake in subjects to site-specific cancer incidence are few. This paper reports the results of a case-control study of erythrocyte selenium in relation to breast carcinoma in premenopausal women. 1 figure, 1 table.

  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. Selenium and the control of thyroid hormone metabolism.

    PubMed

    Köhrle, Josef

    2005-08-01

    Thyroid hormone synthesis, metabolism and action require adequate availability of the essential trace elements iodine and selenium, which affect homeostasis of thyroid hormone-dependent metabolic pathways. The three selenocysteine-containing iodothyronine deiodinases constitute a novel gene family. Selenium is retained and deiodinase expression is maintained at almost normal levels in the thyroid gland, the brain and several other endocrine tissues during selenium deficiency, thus guaranteeing adequate local and systemic levels of the active thyroid hormone T(3). Due to their low tissue concentrations and their mRNA SECIS elements deiodinases rank high in the cellular and tissue-specific hierarchy of selenium distribution among various selenoproteins. While systemic selenium status and expression of abundant selenoproteins (glutathione peroxidase or selenoprotein P) is already impaired in patients with cancer, disturbed gastrointestinal resorption, unbalanced nutrition or patients requiring intensive care treatment, selenium-dependent deiodinase function might still be adequate. However, disease-associated alterations in proinflammatory cytokines, growth factors, hormones and pharmaceuticals modulate deiodinase isoenzyme expression independent from altered selenium status and might thus pretend causal relationships between systemic selenium status and altered thyroid hormone metabolism. Limited or inadequate supply of both trace elements, iodine and selenium, leads to complex rearrangements of thyroid hormone metabolism enabling adaptation to unfavorable conditions.

  3. Review of selenium toxicity in the aquatic food chain.

    PubMed

    Hamilton, Steven J

    2004-06-29

    In many environmental contaminant situations selenium has become the primary element of concern because of its bioaccumulative nature in food webs. Initial concerns about selenium were related to fish kills at Belews Lake, NC, Martin Lake, TX, and Kesterson Reservoir, CA, and to bird deformities at Kesterson Reservoir. Additional concerns were identified under the National Irrigation Water Quality Program at Salton Sea, CA, Kendrick, WY, Stewart Lake, UT, and Grand Valley and Uncompahgre Valley, CO. Recent studies have raised concerns about selenium impacts on aquatic resources in Southeastern Idaho and British Columbia. The growing discomfort among the scientific community with a waterborne criterion has lead the US Environment Protection Agency to consider a tissue-based criterion for selenium. Some aquatic ecosystems have been slow to recover from selenium contamination episodes. In recent years, non-governmental researchers have been proposing relatively high selenium thresholds in diet and tissue relative to those proposed by governmental researchers. This difference in opinions is due in part to the selection of datasets and caveats in selecting scientific literature. In spite of the growing selenium literature, there are needs for additional research on neglected organisms. This review also discusses the interaction of selenium with other elements, inconsistent effects of selenium on survival and growth of fish, and differences in depuration rates and sensitivity among species.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Re-exposure of mallards to selenium after chronic exposure

    USGS Publications Warehouse

    Heinz, G.H.

    1993-01-01

    Adult male mallards (Anas platyrhynchos) were fed a control diet or a diet containing 15 ppm selenium as seleno-D,L-methionine for 21 weeks. After this initial exposure, the mallards were fed untreated food for 12 weeks, then were re-exposed to selenium at 100 ppm for five weeks. During re-exposure to 100 ppm selenium, the birds that had previously been exposed to 15 ppm selenium and those that had not previously been exposed did not differ in percentage of mortality (14.7 and 14.3%), weight loss in survivors (39.3 and 41.20%), selenium concentrations in the livers of survivors (35 and 53 ppm, wet weight), or selenium concentrations in the livers of birds that died (35 and 40 ppm, respectively). When the data from the birds that had previously been exposed to 15 ppm selenium were combined with the data from the birds that had not previously been exposed, selenium concentrations in the livers of birds that had died on the 100-ppm selenium treatment (38 ppm) did not differ from the concentrations in the livers of birds that had survived (43 ppm).

  9. 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.

  10. 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.

  11. Role of oceans as biogenic sources of selenium

    NASA Astrophysics Data System (ADS)

    Amouroux, David; Liss, Peter S.; Tessier, Emmanuel; Hamren-Larsson, Marie; Donard, Olivier F. X.

    2001-07-01

    The pathways leading to the volatilisation and atmospheric transfer of selenium from oceanic environments are poorly understood. They may however affect the global distribution of selenium and its impact on marine and terrestrial ecosystems. In this paper we describe the results of experiments which provide a reasonable estimate of the global selenium budget. Gaseous selenium compounds were determined in the North Atlantic Ocean during a Spring bloom of phytoplankton species which are known to be a large source of atmospheric sulphur. The results demonstrate that significant concentrations of gaseous selenium species occur in surface ocean waters, and their production is closely linked to the gaseous sulphur species turnover. Selective uptake and biotransformation of dissolved selenium in seawater by phytoplankton is a major pathway for the production of gaseous selenium compounds in marine environments and their emission to the atmosphere. It is therefore suggested that such a major selenium source supplies the terrestrial environment with selenium that can be used as an essential nutrient for animal and human life.

  12. [Selenium toxicity in domestic animals].

    PubMed

    Mihajlović, M

    1992-01-01

    The earliest written report of selenium poisoning is thought to be the description by Marco Polo of a necrotic hoof disease of horses that occurred in China in 13. century. However recognition of Se as toxic principle come in the early 1930s. Severity of Se poisoning depends on chemical forms of the element, species of animals and routes of administration. The soluble Se salts (Na2SeO3 and Na2SeO4) appear to be among the more toxic compounds; the Se inherent in grains and selenoamino acids (selenomethionine and selenocystine) appear to have relative moderate toxicity; the poorly soluble forms (e.g., elemental Se, Na2Se, SeS2 and diphenyl selenide) are among the least toxic of the Se compounds. In general, toxicity of Se compounds are substantially less when they are administered orally than when they are given parenterally. Rosenfeld and Beath described three clinical types of Se intoxication: acute selenosis, subacute selenosis (i.e., blind staggers type), and chronic selenosis (i.e., alkali disease type). Acute poisoning occurs when high Se content plants are consumed in large quantities within short period. Accidental acute poisoning occurs as consequence of errors in formulation of a Se supplemented diet. The most characteristic sign of acute selenosis is garlic breath due to the pulmonary excretion of volatile Se metabolites. Other signs include lethargy, excessive salivation, vomiting, dyspnea, muscle tremors and respiratory distress. Pathological findings are: congestion of the liver and kidney, fatty degeneration and focal necrosis of the liver, endocarditis and myocarditis. Subacute selenosis ("blind staggers") occurs as a consequence of exposure to large doses of Se over a longer period of time and manifests with neurological signs (e.g., blindness, ataxia, disorientation) and respiratory distress. This form of selenosis is most frequently observed in grazing animals that have consumed Se-accumulated plants. Chronic selenosis ("alkali disease") comes

  13. Selenium quantum dots: Preparation, structure, and properties

    NASA Astrophysics Data System (ADS)

    Qian, Fuli; Li, Xueming; Tang, Libin; Lai, Sin Ki; Lu, Chaoyu; Lau, Shu Ping

    2017-01-01

    An interesting class of low-dimensional nanomaterials, namely, selenium quantum dots (SeQDs), which are composed of nano-sized selenium particles, is reported in this study. The SeQDs possess a hexagonal crystal structure. They can be synthesized in large quantity by ultrasound liquid-phase exfoliation using NbSe2 powders as the source material and N-Methyl-2-pyrrolidone (NMP) as the dispersant. During sonication, the Nb-Se bonds dissociate; the SeQDs are formed, while niobium is separated by centrifugation. The SeQDs have a narrow diameter distribution from 1.9 to 4.6 nm and can be dispersed with high stability in NMP without the need for passivating agents. They exhibit photoluminescence properties that are expected to find useful applications in bioimaging, optoelectronics, as well as nanocomposites.

  14. Selenium uptake and assessment of the biochemical changes in Arthrospira (Spirulina) platensis biomass during the synthesis of selenium nanoparticles.

    PubMed

    Zinicovscaia, I; Chiriac, T; Cepoi, L; Rudi, L; Culicov, O; Frontasyeva, M; Rudic, V

    2017-01-01

    The process of selenium uptake by biomass of the cyanobacterium Arthrospira (Spirulina) platensis was investigated by neutron activation analysis at different selenium concentrations in solution and at different contact times. Experimental data showed good fit with the Freundlich adsorption isotherm model, with a regression coefficient value of 0.99. In terms of absorption dependence on time, the maximal selenium content was adsorbed in the first 5 min of interaction without significant further changes. It was also found that A. platensis biomass forms spherical selenium nanoparticles. Biochemical analysis was used to assess the changes in the main components of spirulina biomass (proteins, lipids, carbohydrates, and phycobilin) during nanoparticle formation.

  15. Clearance of absorbed selenium by the liver

    SciTech Connect

    Kato, Tatsuko; Read, R.; Rozga, J.; Burk, R.F. )

    1991-03-11

    The liver plays a central role in the metabolism of selenium. It secretes plasma selenoproteins, contains a major fraction of the glutathione peroxidase in the body, and synthesizes excretory metabolites. The role of the liver in processing newly absorbed selenium was studied. Male chow-fed rats were fasted overnight and given 24 ng of selenium as {sup 75}SeO{sub 3}{sup 2{minus}} by stomach tube. Animals were exsanguinated at 15, 30, 45, 60, 90, 120, and 180 min after dosing. Comparison of {sup 75}Se uptake by liver, kidney, heart, muscle, testis, brain, and spleen indicated an earlier uptake by liver than by any other tissue. At 15 min, {sup 75}Se in the portal vein blood was 2.6 times that in the hepatic vein blood. Gel filtration analysis suggested a loose association of {sup 75}Se with protein in plasma at 15 min, but immunoprecipitation indicated it was largely in the form of selenoprotein P after 30 min. End-to-side portacaval shunts (PCS) were constructed in rats and sham-operated animals were used as controls. When {sup 75}SeO{sub 3}{sup 2{minus}} was given to animals with PCS, uptake of {sup 75}Se by liver did not precede uptake by other tissues. Also no gradient was detected across the lungs or kidney. {sup 75}Se content of the kidney was higher in PCS rats than in sham-operated rats. This is consistent with removal of the first-pass effect of the liver facilitating uptake of {sup 75}Se by systemic tissues. These results suggest that the preferential uptake of absorbed selenium by the liver is due both to its position in the portal circulation and to an intrinsic high uptake capacity.

  16. [Selenium and oxidative stress in cancer patients].

    PubMed

    Gorozhanskaia, É G; Sviridova, S P; Dobrovol'skaia, M M; Zybrikhina, G N; Kashnia, Sh R

    2013-01-01

    In order to identify the features of violations of free-radical processes in blood serum of 94 untreated cancer patients with different localization of the tumor (cancer of the stomach, colon, breast, ovarian, hemoblastoses) were determined selenium levels and indicators of oxidative stress (sum of metabolites of nitrogen--NOx, the level of superoxide dismutase--Cu/ZnSOD and malondiialdehyde-MDA, and the activity of catalase). In addition, 40 patients with malignant liver disease and clinical signs of liver failure in the early postoperative period was carried out a comparative evaluation of the efficacy of selenium-containing drug "Selenaze" (sodium selenite pentahydrate). It was found that selenium levels in cancer patients by 25-30% below the norm of 110-120 mg/l at a rate of 73.0 +/- 2.6 mg/l. Low levels of NOx was detected in patients with all tumor localizations (22.1 +/- 1.1 microM, with normal range 28.4 +/- 0.9 microM). The exceptions were patients with extensive malignant process in the liver, in which the NOx levels were significantly higher than normal (p < 0.001). The high level of NOx has a toxic effect on the hepatocyte, causing metabolic disorders and inflammatory-necrotic changes in the liver. Elevated levels of SOD and MDA in normal values of catalase activity was detected in all patients. The use of "Selenaze" in postoperative patients with tumors of the liver increased selenium levels by 10-12%, which was accompanied by a decrease in the content of SOD and NOx, and contributed to earlier recovery of detoxic and synthetic liver function. These findings point to an intensification of oxidative stress and metabolic disorders in the malignant process, which is the basis for metabolic correction.

  17. 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.

  18. 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.

  19. 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.

  20. Selenium binding to human hemoglobin via selenotrisulfide.

    PubMed

    Haratake, Mamoru; Fujimoto, Katsuyoshi; Ono, Masahiro; Nakayama, Morio

    2005-05-25

    Selenotrisulfide (e.g., glutathione selenotrisulfide (GSSeSG)) is an important intermediate in the metabolism of selenite. However, its reactivity with biological substances such as peptides and proteins in the subsequent metabolism is still far from clearly understood, because of its chemical instability under physiological conditions. Penicillamine (Pen) is capable of generating a chemically stable and isolatable selenotrisulfide, PenSSeSPen. To explore the metabolic fate of selenite in red blood cells (RBC), we investigated the reaction of selenotrisulfide with human hemoglobin (Hb) using PenSSeSPen as a model. PenSSeSPen rapidly reacted with Hb under physiological conditions. From the analysis of selenium binding using the Langmuir type binding equation, the apparent binding number of selenium per Hb tetramer almost corresponded to the number of reactive thiol groups of Hb. The thiol group blockade of Hb by iodoacetamide treatment completely inhibited the reaction of PenSSeSPen with Hb. In addition, MALDI-TOF mass spectrometric analysis of the selenium-bound Hb revealed that PenSSe moiety binds to the beta subunits of Hb. Overall, the reaction of PenSSeSPen with Hb appears to involve the thiol exchange between Pen and the cysteine residues on the beta subunit of Hb.

  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. Incorporation of selenium into egg proteins from dietary selenite.

    PubMed

    Davis, R H; Fear, J

    1996-03-01

    1. The deposition of selenium in egg components has been investigated in two experiments in which sodium selenite was added to a conventional cereal-based layer diet. 2. Addition of graded amounts of selenite up to 4 mg Se/kg resulted in linear increases in the selenium content of egg white and yolk, and in protein fractions derived from them. The presence of selenium in yolk phosvitin indicates that deposition is not dependent upon the presence of cysteine. 3. Addition of sodium nitroprusside at 0.l5 and 0.3 g/kg to diets having an addition of selenite at the highest concentration, 4 mg Se/kg, resulted in substantial reductions in the selenium concentration in egg components. 4. Samples from eggs laid by hens receiving a diet containing an additional 8 mg selenite Se/kg were subjected to dialysis against sodium hydroxide or cysteine, or subjected to reduction with hydrochloric acid and zinc under anaerobic conditions. Comparisons were made with similar samples prepared from eggs laid by hens on the control diet. 5. Both sodium hydroxide and cysteine were more effective at extracting additional diet-derived selenium from whole white than from whole yolk. The proportion of selenium that could be extracted from the water-soluble or the high density fractions of yolk by either reagent was similar for both control and high selenium samples. However, neither reagent was effective at removing selenium from the ovalbumin or globin fractions of white from control eggs but substantial amounts were extracted from high selenium samples. 6. Most of the selenium was present in non-reducible forms in all samples. There was significantly more reducible selenium in ovalbumin from control eggs than from all other samples but even so non-reducible selenium accounted for two thirds of the selenium present. 7. The differential responses to chemical treatment suggest that selenium can be deposited in eggs in an unspecified number of different forms. These have still to be characterised

  3. 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.

  4. 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... of vitamin E (68 I.U.) (as d-alpha tocopheryl acetate). (2) Sponsor. See No. 000061 in §...

  5. 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... of vitamin E (68 I.U.) (as d-alpha tocopheryl acetate). (2) Sponsor. See No. 000061 in §...

  6. 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... of vitamin E (68 I.U.) (as d-alpha tocopheryl acetate). (2) Sponsor. See No. 000061 in §...

  7. 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... of vitamin E (68 I.U.) (as d-alpha tocopheryl acetate). (2) Sponsor. See No. 000061 in §...

  8. 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...

  9. Microbial Transformations of Selenium Species of Relevance to Bioremediation

    PubMed Central

    Eswayah, Abdurrahman S.; Smith, Thomas J.

    2016-01-01

    Selenium species, particularly the oxyanions selenite (SeO32−) and selenate (SeO42−), 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

  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.

  11. 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...

  12. 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...

  13. 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...

  14. Urinary selenium excretion in patients with cervical uterine cancer.

    PubMed

    Navarrete, M; Gaudry, A; Revel, G; Martínez, T; Cabrera, L

    2001-02-01

    In this work, we report on a relationship between urinary selenium and the development of cervical uterine cancer. A simple chemical method was developed to concentrate trace amounts of selenium from relatively large urine samples by use of small activated carbon filters. When these filters are irradiated with thermal neutrons, selenium can be determined either by 77mSe (t1/2 = 17.5 s) or 75Se (t1/2 = 120 d). In this article, we report the results for 82 urine samples from women with cervical uterine cancer in several stages of development and from healthy controls. These results show a statistically significant increase of selenium excretion in cancer patients as compared to controls. Urinary selenium excretion is highest for patients in the intermediate stages of the disease.

  15. Effect of exogenous selenium on nicotine induced hyperlipidemia in rats.

    PubMed

    Sreekala, S; Indira, M

    2008-01-01

    The effect of two different doses (1 microg Se/Kg and 50 microg Se/Kg Body wt) of selenium on nicotine induced hyperlipidemia was investigated in rats. Results revealed that nicotine intake caused an increase in concentration of cholesterol, triglycerides, free fatty acids, phospholipids and low density lipoprotein compared to control group. Coadministration of selenium along with nicotine reduced the levels of lipids compared to nicotine group. This reduction was due to reduction in the biosynthesis of lipids as evidenced by the reduced activity of HMGCoA reductase and lipogenic enzymes. Nicotine intake also reduced the absorption of selenium in the intestine. Histopathological studies revealed that selenium at a dose of 1 microg was more effective in reducing lipid levels and higher dose of selenium was toxic.

  16. Urinary selenium levels in Japanese males and females

    SciTech Connect

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

    1990-04-01

    In the investigation of selenium metabolism, the analysis of urinary selenium is essential, since selenium is excreted primarily via urine. To elucidate the relationship between urinary selenium level and age or sex, the authors collected 789 single-void urine samples from inhabitants of Sagamihara area, nearby Tokyo. More than 30 samples constituted each age class of 10 year-interval for both sexes. To analyze such a large number of samples, they have developed a microfluorometric method. Researchers have found remarkable differences in urinary selenium levels due to the locality of the samples in their countries. Therefore, the authors examined urine samples from 9 districts throughout Japan and found significant differences among districts examined.

  17. Removal of arsenic and selenium from wastewaters - a review

    SciTech Connect

    Mirza, A.H.; Ramachandran, V.

    1996-12-31

    Arsenic and selenium are found in low quantities together with other metals in several nonferrous metallurgical process streams such as scrubber blowdown solution, acid plant wastewater, gas cleaning plant water, etc. Normally, the other metals in these streams are present as cations and can be precipitated by conventional lime treatment and sulfide polishing. However, arsenic and selenium are invariably present as anions, AsO{sub 3}{sup 3-} and AsO{sub 4}{sup 3-} in the case of arsenic and SeO{sub 3}{sup 2-} and SeO{sub 4}{sup 2-} for selenium. Conventional lime treatment removes most of the arsenic, but it does not remove selenium. The present paper reviews the processes and technologies developed to date on the removal of arsenic and selenium from metallurgical process streams. 58 refs., 4 figs., 1 tab.

  18. 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.

  19. 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.

  20. 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...

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

    USGS Publications Warehouse

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

    2008-01-01

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

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

    USGS Publications Warehouse

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

    2009-01-01

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

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

    USGS Publications Warehouse

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

    2009-01-01

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

  4. 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

  5. Serum Selenium Levels in Euthyroid Nodular Thyroid Diseases.

    PubMed

    Sakız, Davut; Kaya, Ahmet; Kulaksizoglu, Mustafa

    2016-11-01

    The thyroid gland is susceptible to nodulation. The mechanism responsible for the growth of only some follicular cells, which results in nodule formation, is not yet clear. Selenium deficiency may be a risk factor in the development of thyroid nodules. The aim of this study was to investigate the relationship between selenium levels in patients with euthyroid nodular thyroid disease. Seventy patients with a solitary euthyroid thyroid nodule, 70 patients with more than one euthyroid nodule, and 60 healthy patients without thyroid nodules were included in the study. Venous serum samples were stored at -80°C and analyzed the same day using spectrometry. The selenium levels of patients with multiple thyroid nodules, solitary nodules, and patients without nodules were 57.3 ± 14.8 μg/L; 58.8 ± 15.1 μg/L; and 57.6 ± 13.3 μg/L, respectively. The mean serum selenium level of all patients included in the study was 57.9 ± 14.4 μg/L. Although serum selenium levels were slightly higher in men, a statistically significant difference was not observed. In our study, a significant relationship between serum selenium levels and nodular thyroid disease was not seen. Our study was undertaken in an iodine sufficient region. Mean serum selenium levels were lower compared with many other studies, which may be associated with the low selenium content of the soil. Nodular thyroid disease shows multifactorial features. When our study is considered together with previous studies, serum selenium levels may considered to be effective on structural thyroid diseases if combined with additional factors such as severe iodine deficiency. Further studies are required to assess the role of selenium in thyroid nodule formation.

  6. 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.

  7. 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...

  8. Associated Factors and Standard Percentiles of Blood Pressure among the Adolescents of Jahrom City of Iran, 2014

    PubMed Central

    Sarikhani, Yaser; Emamghorashi, Fatemeh; Jafari, Fatemeh; Tabrizi, Reza; Karimpour, Saeed; Kalateh sadati, Ahmad; Akbari, Maryam

    2017-01-01

    Background. High blood pressure in adults is directly correlated with increased risk of cardiovascular diseases. Hypertension in childhood and adolescence could be considered among the major causes of this problem in adults. This study aimed to investigate the factors associated with hypertension among the adolescents of Jahrom city in Iran and also standard percentiles of blood pressure were estimated for this group. Methods. In this community-based cross-sectional study 983 high school students from different areas of the city were included using a multistage random cluster sampling method in 2014. Blood pressure, weight, and height of each student measured using standard methods. Data were analyzed by statistical software SPSS 16. Results. In total, 498 male and 454 female students were included in this study. Average systolic blood pressure of students was 110.27 mmHg with a variation range of 80.6–151.3. Average diastolic blood pressure was 71.76 mmHg with the variation range of 49.3–105. Results of this study indicated that there was a significant relationship between gender, body mass index, and parental education level with systolic and diastolic blood pressure of the students (P < 0.05). Conclusions. Body mass index was one of the most important changeable factors associated with blood pressure in adolescents. Paying attention to this factor in adolescence could be effective in prevention of cardiovascular diseases in adulthood. PMID:28191019

  9. Associated Factors and Standard Percentiles of Blood Pressure among the Adolescents of Jahrom City of Iran, 2014.

    PubMed

    Sarikhani, Yaser; Heydari, Seyed Taghi; Emamghorashi, Fatemeh; Jafari, Fatemeh; Tabrizi, Reza; Karimpour, Saeed; Kalateh Sadati, Ahmad; Akbari, Maryam

    2017-01-01

    Background. High blood pressure in adults is directly correlated with increased risk of cardiovascular diseases. Hypertension in childhood and adolescence could be considered among the major causes of this problem in adults. This study aimed to investigate the factors associated with hypertension among the adolescents of Jahrom city in Iran and also standard percentiles of blood pressure were estimated for this group. Methods. In this community-based cross-sectional study 983 high school students from different areas of the city were included using a multistage random cluster sampling method in 2014. Blood pressure, weight, and height of each student measured using standard methods. Data were analyzed by statistical software SPSS 16. Results. In total, 498 male and 454 female students were included in this study. Average systolic blood pressure of students was 110.27 mmHg with a variation range of 80.6-151.3. Average diastolic blood pressure was 71.76 mmHg with the variation range of 49.3-105. Results of this study indicated that there was a significant relationship between gender, body mass index, and parental education level with systolic and diastolic blood pressure of the students (P < 0.05). Conclusions. Body mass index was one of the most important changeable factors associated with blood pressure in adolescents. Paying attention to this factor in adolescence could be effective in prevention of cardiovascular diseases in adulthood.

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

    PubMed

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

    2012-02-21

    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 ofmicrogravity, 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 UFHADMand UFHADF could be useful in designing dose reduction strategies through optimized positioning of an astronaut during encounters with solar particle events.

  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. Spectrum of sodiumlike selenium - Se XXIV

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  13. 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.

  14. Serum selenium and ceruloplasmin in nigerians with peripartum cardiomyopathy.

    PubMed

    Karaye, Kamilu M; Yahaya, Isah A; Lindmark, Krister; Henein, Michael Y

    2015-04-07

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

  15. The Content of Plasma Selenium in Early Admitted Septic Patients

    PubMed Central

    Moghaddam, Omid Moradi; Lahiji, Mohammad Niakan; Moghaddas, Azadeh; Farasatinasab, Maryam; Nasiripour, Somayyeh

    2017-01-01

    Objective: Selenium depletion has been reported in critical illness correlates with an increase in mortality and morbidity. In this study, we aimed to access the selenium plasma levels of septic patients early at the Intensive Care Unit (ICU) admission in order to compare with reference range. Methods: We conducted a cross-sectional study in a university affiliated hospital aiming to assess the early plasma level of selenium in ICU admitted patients. eighty patients diagnoses with sepsis were included and considered for characteristic evaluation, monitoring criteria assessment and also blood sampling. All blood sampling was performed during 48 hours of the ICU admission in order to determined the plasma Selenium level by atomic absorption method. Findings: The mean plasma levels of selenium in male and female was 98.14 ± 23.52 and 78.1 ± 24.46 μ/L, respectively. Although selenium plasma levels was higher in the ICU male patients significantly, both had near normal range (80 μ/L). Conclusion: In this study we found that in early admitted Iranian ICU patients in Tehran, selenium deficiency has not routinely seen but probably will happen during ICU hospitalization. PMID:28331867

  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. Serum Selenium and Ceruloplasmin in Nigerians with Peripartum Cardiomyopathy

    PubMed Central

    Karaye, Kamilu M.; Yahaya, Isah A.; Lindmark, Krister; Henein, Michael Y.

    2015-01-01

    The study aimed to determine if selenium deficiency, serum ceruloplasmin and traditional birth practices are risk factors for peripartum cardiomyopathy (PPCM), in Kano, Nigeria. This is a case-control study carried out in three hospitals, and PPCM patients were followed up for six months. Critically low serum selenium concentration was defined as <70 µg/L. A total of 39 PPCM patients and 50 controls were consecutively recruited after satisfying the inclusion criteria. Mean serum selenium in patients (61.7 ± 14.9 µg/L) was significantly lower than in controls (118.4 ± 45.6 µg/L) (p < 0.001). The prevalence of serum selenium <70 µg/L was significantly higher among patients (76.9%) than controls (22.0%) (p < 0.001). The mean ceruloplasmin and prevalence of socio-economic indices, multiparity, pregnancy-induced hypertension, obesity and twin pregnancy were not different between the groups (p > 0.05). Logistic regression showed that rural residency significantly increased the odds for serum selenium <70 µg/L by 2.773-fold (p = 0.037). Baseline serum levels of selenium and ceruloplasmin were not associated with six-month mortality. This study has shown that selenium deficiency is a risk factor for PPCM in Kano, Nigeria, and is related to rural residency. However, serum ceruloplasmin, customary birth practices and some other characteristics were not associated with PPCM in the study area. PMID:25853263

  18. A prospective study of selenium status and breast cancer risk

    SciTech Connect

    Hunter, D.J.; Stampfer, M.J.; Colditz, G.A.; Speizer, F.E.; Willett, W.C. ); Morris, J.S. )

    1990-09-05

    Low dietary intake of selenium has been proposed as a risk factor for breast cancer. To address this hypothesis, the authors collected toenail clippings from 62,641 women in the Nurses' Health Study cohort who were free from cancer in 1982 and 1983. The selenium concentration in nails has been shown to reflect dietary intake of selenium. During 53 months of follow-up, 434 cases of breast cancer were diagnosed among women who had submitted a set of toenail clippings, and they matched one control free from breast and other cancers to each case. The mean selenium level in toenails in the cases was almost identical to that of the controls. After controlling for known breast cancer risk factors, the relative risk for women in the highest quintile of selenium as compared with the lowest quintile was 1.10 and there was not trend across quintiles. Results were similar for both premenopausal and postmenopausal women. Although these data do not exclude a possible influence of selenium intake before adulthood on subsequent risk of breast cancer, selenium intake later in life is not likely to be an important factor in the etiology of breast cancer.

  19. Iodine and Selenium Intakes of Postmenopausal Women in New Zealand.

    PubMed

    Brough, Louise; Gunn, Caroline A; Weber, Janet L; Coad, Jane; Jin, Ying; Thomson, Jasmine S; Mauze, Mathilde; Kruger, Marlena C

    2017-03-09

    Iodine and selenium are required for thyroid function. This study investigated iodine and selenium intakes in healthy, women aged 50-70 years (n = 97) from three cities in the North Island of New Zealand, after mandatory fortification of bread with iodised salt. Iodine and selenium concentrations were determined in 24-h urine samples; daily intakes were extrapolated from amounts in urine (90% and 55% of daily intake, respectively). Three day diet diaries (3DDD) also estimated selenium and iodine (excluding iodised salt) intake. Median urinary iodine concentration (UIC) was 57 (41, 78) µg/L, indicating mild iodine deficiency. Estimated median iodine intake based on urine was 138 (100, 172) µg/day, below Recommended Dietary Intake (RDI) (150 µg/day) with 25% below Estimated Average Requirement (EAR) (100 µg/day). Estimated median selenium intake was 50 (36, 71) µg/day based on urine and 45 (36, 68) µg/day using 3DDD, below RDI (60 µg/day) with 49%-55% below EAR (50 µg/day). Median bread intakes were low at 1.8 (1.1, 2.7) serves/day; 25% consumed ≤1 serve/day. Although population iodine intakes improved following mandatory fortification, some had low intakes. Selenium intakes remain low. Further research should investigate thyroid function of low consumers of iodine fortified bread and/or selenium in New Zealand.

  20. Iodine and Selenium Intakes of Postmenopausal Women in New Zealand

    PubMed Central

    Brough, Louise; Gunn, Caroline A.; Weber, Janet L.; Coad, Jane; Jin, Ying; Thomson, Jasmine S.; Mauze, Mathilde; Kruger, Marlena C.

    2017-01-01

    Iodine and selenium are required for thyroid function. This study investigated iodine and selenium intakes in healthy, women aged 50–70 years (n = 97) from three cities in the North Island of New Zealand, after mandatory fortification of bread with iodised salt. Iodine and selenium concentrations were determined in 24-h urine samples; daily intakes were extrapolated from amounts in urine (90% and 55% of daily intake, respectively). Three day diet diaries (3DDD) also estimated selenium and iodine (excluding iodised salt) intake. Median urinary iodine concentration (UIC) was 57 (41, 78) µg/L, indicating mild iodine deficiency. Estimated median iodine intake based on urine was 138 (100, 172) µg/day, below Recommended Dietary Intake (RDI) (150 µg/day) with 25% below Estimated Average Requirement (EAR) (100 µg/day). Estimated median selenium intake was 50 (36, 71) µg/day based on urine and 45 (36, 68) µg/day using 3DDD, below RDI (60 µg/day) with 49%–55% below EAR (50 µg/day). Median bread intakes were low at 1.8 (1.1, 2.7) serves/day; 25% consumed ≤1 serve/day. Although population iodine intakes improved following mandatory fortification, some had low intakes. Selenium intakes remain low. Further research should investigate thyroid function of low consumers of iodine fortified bread and/or selenium in New Zealand. PMID:28282932

  1. 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.

  2. Prevention of rat breast cancer by genistin and selenium.

    PubMed

    Hamdy, Soha M; Latif, Abdel Karim M Abdel; Drees, Ehab A; Soliman, Sahar M

    2012-09-01

    Breast cancer is the second leading cause of cancer death among women and the third most common cancer. In this study, we investigated the chemoprevention efficacy of each of soy genistin, selenium or a combination of them against breast cancer. Seventy-five female rats were divided into five groups : control group (I); 7,12-dimethylbenz(a)anthracene (DMBA) group (II); DMBA treated with genistin group (III); DMBA treated with selenium group (IV); and DMBA treated with genistin combined with selenium group (V). The treatments were daily administered for 3 months. There were a significant decrease in body weight and serum total antioxidant, while a significant elevation in serum total sialic acid, carcinoembryonic antigen, prolactin, estradiol, nitric oxide, and malondialdhyde of DMBA injected rats compared with control group. Administration of genistin and selenium was associated with decreasing levels of tumorigenicity, endocrine derangement, and oxidative stress. Formation of breast carcinoma in DMBA-induced rats and abnormal changes were ameliorated in the rats treated with genistin/selenium or genistin alone. Supplementation of genistin alone or with selenium provided antioxidant defense with high-potential chemopreventive activity against DMBA-induced mammary tumors more than selenium alone.

  3. Correlation of mercury and selenium in the human kidney.

    PubMed

    Drasch, G; Wanghofer, E; Roider, G; Strobach, S

    1996-12-01

    The total mercury (Hg) and selenium (Se) concentrations were determined in kidney cortex samples of 195 deceased, non-occupationally burdened individuals. Mercury was determined by means of Cold-vapour Atomic Absorption Spectrometry (CV-AAS) and selenium by Graphite-Furnace Atomic Absorption Spectrometry (GF-AAS). The molar Se/Hg ratio is high (up to (a) 300) in cases with relatively low mercury concentrations [Hg]. The ratio decreases with increasing [Hg]. At [Hg] of 700-1000 ng/g it reaches unity, where it remains constant even at larger [Hg]. Since in vitro mercury and selenium form relatively stable adducts, our results suggest the formation of a 1:1 Hg-Se compound that may explain mercury detoxification by selenium. This effect also results in the trapping of available selenium by mercury, too. Decreasing the reserve of free (i.e. not Hg-bound) selenium. The effect of this decrease of free selenium is under further investigation.

  4. 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.

  5. 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.

  6. Nanostructured selenium for preventing biofilm formation on polycarbonate medical devices.

    PubMed

    Wang, Qi; Webster, Thomas J

    2012-12-01

    Biofilms are a common cause of persistent infections on medical devices as they are easy to form and hard to treat. The objective of this study was for the first time to coat selenium (a natural element in the body) nanoparticles on the surface of polycarbonate medical devices (such as those used for medical catheters) and to examine their effectiveness at preventing biofilm formation. The size and distribution of selenium coatings were characterized using scanning electron microscopy and atomic force microscopy. The strength of the selenium coating on polycarbonate was assessed by tape-adhesion tests followed by atomic absorption spectroscopy. Results showed that selenium nanoparticles had a diameter of 50-100 nm and were well distributed on the polycarbonate surface. In addition, more than 50% of the selenium coating survived the tape-adhesion test as larger nanoparticles had less adhesion strength to the underlying polycarbonate substrate than smaller selenium nanoparticles. Most significantly, the results of this in vitro study showed that the selenium coatings on polycarbonate significantly inhibited Staphylococcus aureus growth to 8.9% and 27% when compared with an uncoated polycarbonate surface after 24 and 72 h, respectively. Importantly, this was accomplished without using antibiotics but rather with an element (selenium) that is natural to the human body. Thus, this study suggests that coating polymers (particularly, polycarbonate) with nanostructured selenium is a fast and effective way to reduce bacteria functions that lead to medical device infections. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 3205-3210, 2012.

  7. Selenium in San Francisco Bay - 30 Years of Surprises

    NASA Astrophysics Data System (ADS)

    Cutter, G. A.

    2015-12-01

    The trace element selenium exists in multiple oxidation states (VI, IV, 0, -II) and chemical forms within an oxidation state, and this chemical speciation affects its bio-availability and geochemical cycling. The interactions between the physical circulation and riverine inputs, changing ecosystem components, and industrial inputs to the San Francisco Bay have had profound and surprising influences on the biogeochemical behavior of selenium in this estuary. In the mid-1980s dissolved selenium was relatively elevated and enriched in selenite (SeIV) in the mid-estuary, occurrences that were quantitatively linked to inputs from oil refinery effluents. Suspended particulate selenium concentrations were at a level considered problematic for filter feeding clams with high assimilation efficiencies. By 1999 oil refineries had implemented selenium removal processes that dramatically dropped the concentrations of total dissolved selenium and selenite by over 65% in the estuarine water column. Surprisingly, the concentrations of selenium in suspended particles did not drop as dramatically. We suspect that changes in the ecosystem, including the abundance of certain phytoplankton species and changes in benthic grazing affect the abundance of selenium in suspended particles. These and other changes within the San Francisco Bay system have been simulated in numerical models that reveal other surprising aspects of selenium cycling in this estuary. Data and models will be discussed in this presentation, and implications for other trace elements presented.

  8. Comparison of 3 methods of selenium assessment in cattle.

    PubMed Central

    Waldner, C; Campbell, J; Jim, G K; Guichon, P T; Booker, C

    1998-01-01

    Three tests are routinely done to assess blood status of selenium in cattle: serum selenium, whole blood selenium, and glutathione peroxidase. The objective of this study was to compare the various analytical methods for determining blood selenium status in groups of mature cows and beef calves. Twenty to 30 blood samples per herd were collected from 8 beef herds in central Alberta and 1 dairy in Alberta herd twice a year from the spring of 1992 through the fall of 1995, and once from 185 spring calves in 2 beef herds in Saskatchewan. Serum and whole blood samples were submitted to 1 laboratory and whole blood samples were submitted to a 2nd laboratory. Samples for glutathione peroxidase determinations were submitted to a 3rd laboratory. Pearson's correlation coefficients and Cohen's kappa were calculated for each possible comparison among the different measures. The best agreement was observed between serum and whole blood analysis within Laboratory A. The remaining comparisons reflected poor agreement. Comparison of herd-level assessment resulted in better agreement than comparison of individual sample results among laboratories and procedures for all combinations tested. Serum selenium analysis was the only laboratory procedure for which external reference material was utilized. Serum selenium, whole blood selenium, and glutathione peroxidase measure different compartments of the blood selenium pool. The time frame of interest, supplementation practices, and the stability of recent dietary intake determine the optimum assessment method for individual animals or herds. Determination of the serum status or of blood selenium is more consistently measured at the herd-level than for individual samples. PMID:9559213

  9. Teratogenic effects of selenium in natural populations of freshwater fish.

    PubMed

    Lemly, A D

    1993-10-01

    The prevalence of abnormalities and associated tissue selenium residues were assessed for the fish population of Belews Lake, North Carolina, and two reference lakes in 1975, 1978, 1982, and 1992. Teratogenic defects identified included lordosis, kyphosis, scoliosis, and head, mouth, and fin deformities. Many fish exhibited multiple malformations and some were grossly deformed and distorted in appearance. Other abnormalities observed were edema, exophthalmus, and cataracts. Whole-body tissue residues of selenium in the fishes of Belews Lake were up to 130 times those in the reference lakes and the incidence of abnormalities was some 7 to 70 times greater. Teratogenic defects increased as selenium levels rose between 1975 and 1982 and fell with declining selenium levels between 1982 and 1992 as selenium inputs into Belews Lake were curtailed. The relationship between selenium residues and prevalence of malformations approximated an exponential function (R2 = 0.881, P < 0.01; cubic model) for centrarchids over the range of 1-80 micrograms/g dry wt selenium and 0-70% deformities. This relationship could be useful in evaluating the role of teratogenic effects in warm-water fish populations suspected of having selenium-related reproductive failure. Unique conditions may have existed in Belews Lake which led to the high frequency and persistence of deformities in juvenile and adult fish. In other, less-contaminated locations competition and predation may eliminate malformed individuals in all but the larval life stage. Teratogenesis could be an important, but easily overlooked phenomenon contributing to fishery reproductive failure in selenium-contaminated aquatic habitats.

  10. The selenium-rich C-terminal domain of mouse selenoprotein P is necessary for the supply of selenium to brain and testis but not for the maintenance of whole body selenium.

    PubMed

    Hill, Kristina E; Zhou, Jiadong; Austin, Lori M; Motley, Amy K; Ham, Amy-Joan L; Olson, Gary E; Atkins, John F; Gesteland, Raymond F; Burk, Raymond F

    2007-04-13

    Selenoprotein P (Sepp1) has two domains with respect to selenium content: the N-terminal, selenium-poor domain and the C-terminal, selenium-rich domain. To assess domain function, mice with deletion of the C-terminal domain have been produced and compared with Sepp1-/- and Sepp1+/+ mice. All mice studied were males fed a semipurified diet with defined selenium content. The Sepp1 protein in the plasma of mice with the C-terminal domain deleted was determined by mass spectrometry to terminate after serine 239 and thus was designated Sepp1Delta240-361. Plasma Sepp1 and selenium concentrations as well as glutathione peroxidase activity were determined in the three types of mice. Glutathione peroxidase and Sepp1Delta240-361 accounted for over 90% of the selenium in the plasma of Sepp1Delta240-361 mice. Calculations using results from Sepp1+/+ mice revealed that Sepp1, with a potential for containing 10 selenocysteine residues, contained an average of 5 selenium atoms per molecule, indicating that shortened and/or selenium-depleted forms of the protein were present in these wild-type mice. Sepp1Delta240-361 mice had low brain and testis selenium concentrations that were similar to those in Sepp1-/- mice but they better maintained their whole body selenium. Sepp1Delta240-361 mice had depressed fertility, even when they were fed a high selenium diet, and their spermatozoa were defective and morphologically indistinguishable from those of selenium-deficient mice. Neurological dysfunction and death occurred when Sepp1Delta240-361 mice were fed selenium-deficient diet. These phenotypes were similar to those of Sepp1-/- mice but had later onset or were less severe. The results of this study demonstrate that the C terminus of Sepp1 is critical for the maintenance of selenium in brain and testis but not for the maintenance of whole body selenium.

  11. Selenium as an antidote in the treatment of mercury intoxication.

    PubMed

    Bjørklund, Geir

    2015-08-01

    Selenium (Se) is an essential trace element for humans. It is found in the enzyme glutathione peroxidase. This enzyme protects the organism against certain types of damage. Some data suggest that Se plays a role in the body's metabolism of mercury (Hg). Selenium has in some studies been found to reduce the toxicity of Hg salts. Selenium and Hg bind in the body to each other. It is not totally clear what impact the amount of Se has in the human body on the metabolism and toxicity of prolonged Hg exposure.

  12. Selenium Level and Dyslipidemia in Rural Elderly Chinese

    PubMed Central

    Su, Liqin; Gao, Sujuan; Unverzagt, Frederick W.; Cheng, Yibin; Hake, Ann M.; Xin, Pengju; Chen, Chen; Liu, Jingyi; Ma, Feng; Bian, Jianchao; Li, Ping; Jin, Yinlong

    2015-01-01

    Objective Higher selenium level has been hypothesized to have the potential to reduce the risk of cardiovascular diseases including dyslipidemia. However, results from previous studies are inconsistent. This study aims to determine the association between selenium level and dyslipidemia in elderly Chinese with relatively low selenium status. Methods A cross-sectional study of 1859 participants aged 65 or older from four rural counties in China was conducted. Serum total cholesterol (TC), triglycerides (TG), high density lipoprotein-cholesterol (HDLC) and low-density lipoprotein-cholesterol (LDLC), nail selenium concentration and APOE genotype were measured in all subjects. The four types of dyslipidemia were defined as >5.17mmol/L for High-TC, >1.69 mmol/L for High-TG, >3.36 mmol/L for High-LDLC, and <1.04 mmol/L for Low-HDLC according to Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults. Logistic models adjusting for age, gender, APOE genotype, body mass index, alcohol consumption, smoking, physical activity, medication use for cardiovascular diseases were used to examine the relationship between selenium levels and the risk of dyslipidemia. Results Mean nail selenium concentration was 0.465μg/gin this sample. Rates for High-TC, High-LDLC, High-TG, Low-HDLC were 18.13%, 13.23%, 12.21% and 32.76% respectively. Results from logistic models indicated that higher selenium levels were significantly associated with higher risk of High-TC, High-LDLC and lower risk of Low-HDLC adjusting for covariates (p < 0.0001). Compared with the lowest selenium quartile group, participants in selenium quartile groups 2, 3 and 4 had significantly higher rates of High-TC, High-LDLC, High-TG, and lower rate of Low-HDLC adjusting for covariates. No significant association was observed between selenium level and the risk of High-TG. APOEε4 carriers had higher rates of High-TC and High-LDLC. There was no interaction between selenium level and APOE with the rates of

  13. [Correction of selenium deficiency in patients with pneumonia].

    PubMed

    Bakulin, I G; Novozhenov, V G; Orlov, A M; Gmoshinskiĭ, I V; Mazo, V K

    2004-01-01

    The estimation of selenium (Se) safety in patients with pneumonia is important for evaluation of antioxidant defense system capacity and the immune status of the patients. The research has been carried out on the serum Se levels in patients with pneumonia at standard treatment and at treatment with the usage of selenium enriched food supplement (Se-spirulina). The results of research have shown that application of additional selenium in amount providing physiological requirement leads to full varnishing its deficiency cases and to restoration in the majority of patients the suboptimum Se level.

  14. 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

  15. 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.

  16. 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.

  17. Selenium toxicosis in wild aquatic birds

    USGS Publications Warehouse

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

  18. Serum selenium assay following serum ferritin assay

    SciTech Connect

    Stevens, R.G.; Morris, J.S.; Hann, H.L.; Pulsipher, B.; Stahlhut, M.W.

    1986-08-01

    Stored serum samples can be an important research resource into the etiology of cancer. These sera cannot be replaced and should therefore be used to best advantage. In previous epidemiologic studies, only single serum constituents have been assayed in individual serum samples. For example, serum ferritin has been examined in samples stored for as long as 10 years at -20C for a possible relation with general mortality (1) and cancer death (2). Ferritin is the tissue iron-storage protein and is therefore subject to denaturation. Serum selenium has also been examined in relation to cancer risk in a prospective manner by using stored frozen serum samples (3, 4). The interactions of a variety of serum factors in relation to cancer risk would be a desirable research goal, except that the amounts of serum typically available in frozen serum banks are less than 1 ml. It was the purpose of this investigation to determine if a radioimmunoassay for ferritin affected a subsequent neutron activation assay for selenium on the same 0.1 ml serum sample.

  19. 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.

  20. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, April and July 2007

    USGS Publications Warehouse

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

    2007-01-01

    This report presents the results for two sampling periods during a 4-year monitoring survey to provide a characterization of selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species, and total suspended solids were determined in water samples, and total selenium was determined in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species-western mosquitofish (Gambusia affinis), and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Total selenium concentrations in water for both sampling periods ranged from 1.43 to 47.1 micrograms per liter, predominately as selenate, which is typical of waters leached out of selenium-contaminated marine shales under alkaline and oxidizing conditions. Total selenium concentrations ranged from 0.88 to 20.2 micrograms per gram in biota, and from 0.15 to 28.9 micrograms per gram in detritus and sediment.

  1. Plasma selenium levels and dietary selenium intakes of formula-fed (FF) and cow's milk-fed (CMF) infants

    SciTech Connect

    Gropper, S.; Anderson, K.; Landing, W.; Acosta, P. Florida State Univ., Tallahassee Ross Labs., Columbus, OH )

    1990-02-26

    The plasma selenium concentrations of 57 infants eight to 12 months of age ingesting either cow's milk or milk-based infant formula as their primary beverage as part of a mixed diet for at least three months was assessed using flameless atomic absorption spectrophotometry. The mean ({plus minus}SD) daily dietary selenium intake of 26 cow's milk-fed infants (34{plus minus} 13 ug) was significantly greater than that of 31 formula-fed infants (22{plus minus}11 ug). The mean ({plus minus}SD) plasma selenium concentration of infants fed cow's mild (39{plus minus}11 ug/L) was also significantly greater than that of infants fed formula (31{plus minus}12 ug/L). Both groups of infants ingested similar total energy intakes; however, the infants fed cow's milk received more total protein and selenium and a greater percentage of protein and selenium from their primary beverage than the infants receiving formula. Both groups of infants were consuming a mixed diet with similar sources of selenium. These data suggest that cow's milk is a richer source of selenium than infant formulas.

  2. 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 ...

  3. Effects of Dietary Selenium, Sulphur and Copper Levels on Selenium Concentration in the Serum and Liver of Lamb

    PubMed Central

    Netto, Arlindo Saran; Zanetti, Marcus Antonio; Correa, Lisia Bertonha; Del Claro, Gustavo Ribeiro; Salles, Márcia Saladini Vieira; Vilela, Flávio Garcia

    2014-01-01

    Thirty-two lambs were distributed in eight treatments under 2×2×2 factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning. PMID:25083101

  4. Effects of dietary selenium, sulphur and copper levels on selenium concentration in the serum and liver of lamb.

    PubMed

    Netto, Arlindo Saran; Zanetti, Marcus Antonio; Correa, Lisia Bertonha; Del Claro, Gustavo Ribeiro; Salles, Márcia Saladini Vieira; Vilela, Flávio Garcia

    2014-08-01

    Thirty-two lambs were distributed in eight treatments under 2×2×2 factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning.

  5. Selenium accumulation in captive American kestrels (Falco sparverius) fed selenomethionine and naturally incorporated selenium

    SciTech Connect

    Yamamoto, J.T.; Wilson, B.W.; Santolo, G.M.

    1998-12-01

    Male-female pairs of kestrels were maintained for 11 weeks on diets containing 5 or 9 ppm selenium (Se) (dry weight) as seleno-L-methionine, or naturally incorporated Se in the form of mammals collected at Kesterson Reservoir, CA, USA. Selenium concentrations in blood and excreta of male and female kestrels within groups were similar. Near-maximal mean Se concentrations in blood were observed after the 5th week of treatment in the seleno-L-methionine-treated kestrels, and an approximately 1:1 ratio was observed between maximal blood concentrations and dietary concentrations. All treatment groups exhibited reduction of Se concentration in excreta, but not in blood, to baseline values 4 weeks after treatment ended. No birds were observed to exhibit signs of general illness or Se toxicity during the study.

  6. Electronic Structure of Pure Selenium and Tellurium Chains and Selenium Rings and with Impurities

    NASA Astrophysics Data System (ADS)

    Maharjan, N. B.; Cho, Hwa-Suck; Scheicher, R. H.

    2005-03-01

    We have studied the electronic structures of pure chain-structured Selenium and Tellurium and with chalcogen impurities as well as ring-structured Selenium both pure and with Tellurium impurity atoms. The Hartree-Fock Cluster Theory procedure combined with many-body perturbation theory procedure has been used. The accuracy of the calculated electronic wave functions is tested by the investigation of ^77Se and ^125Te nuclear quadrupole interaction parameters. Good agreement is found with experiment for the pure systems. For the impurity systems, the agreement is reasonable but suggests the need for inclusion of more extensive relaxation around the impurity atoms. (*) Current Address: Dept. of Physics, Uppsala University, Sweden (**) Also: Dept. of Physics, University of Central Florida, Orlando, Florida

  7. /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.

  8. Evaluation of the inorganic selenium biotransformation in selenium-enriched yogurt by HPLC-ICP-MS.

    PubMed

    Alzate, Adriana; Cañas, Benito; Pérez-Munguía, Sandra; Hernández-Mendoza, Hector; Pérez-Conde, Concepción; Gutiérrez, Ana Maria; Cámara, Carmen

    2007-11-28

    Selenium is an essential element in the human diet. Interestingly, there has been an increased consumption of dietary supplements containing this element in the form of either inorganic or organic compounds. The effect of using selenium as a dietary supplement in yogurt has been evaluated. For this purpose, different concentrations of inorganic Se (ranging from 0.2 to 5000 microg g(-1)) have been added to milk before the fermentation process. Biotransformation of inorganic Se into organic species has been carefully evaluated by ion-exchange, reversed-phase, or size-exclusion chromatography, coupled to inductively coupled plasma mass spectrometry (ICP-MS). Yogurt fermentation in the presence of up to 2 microg g(-1) of Se(IV) produces a complete incorporation of this element into proteins as has been demonstrated applying a dialysis procedure. Analysis by SEC-ICP-MS showed that most of them have a molecular mass in the range of 30-70 kDa. Species determination after enzymatic hydrolysis has allowed the identification of Se-cystine using two different chromatographic systems. The biotransformation process that takes place during yogurt fermentation is very attractive because yogurt can act as a source of selenium supplementation.

  9. 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.

  10. Inhibition of Selenium Metabolism in the Oral Pathogen Treponema denticola▿

    PubMed Central

    Jackson-Rosario, Sarah; Self, William T.

    2009-01-01

    In this report we provide evidence that the antimicrobial action of stannous salts and a gold drug, auranofin, against Treponema denticola is mediated through inhibition of the metabolism of selenium for synthesis of selenoproteins. PMID:19363113

  11. Decrease in selenium status in relation to coal dust exposure.

    PubMed

    Oryszczyn, M P; Godin, J; Frette, C; Hellier, G; Bertrand, J P; Pham, Q T; Kauffmann, F

    1996-09-01

    Selenium (Se) plasma levels were studied in 222 coal miners to assess whether selenium is decreased in relation to coal dust exposure, taking age, alcohol, and tobacco consumption into account. Selenium levels decreased significantly with age and current tobacco consumption, among miners aged 34-50. Long-term and current exposure to coal dust were studied. The lowest Se values were observed for those with both long-term and current exposure (60.2 ng/ml), the highest for those never or slightly exposed (64.1 ng/ml); those with long-term exposure not currently exposed fell in an intermediate position (61.3 ng/ml). No relation was observed with alcohol consumption. The association of coal dust with low selenium remained significant after adjustment for age and smoking.

  12. 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

  13. Selenium toxicity: cause and effects in aquatic birds.

    PubMed

    Spallholz, Julian E; Hoffman, David J

    2002-04-01

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

  14. 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.

  15. Mechanism of Selenium Chemoprevention and Therapy in Prostate Cancer

    DTIC Science & Technology

    2007-11-01

    Prevention of Cancer study initiated by Clark et al. (8). Supplementa- tion of people with selenized yeast was capable of reducing the overall cancer...such as selenate or selenite, are known to produce genotoxic effects. Organic selenium-containing com- pounds, such as selenomethionine and...people with selenized yeast was capable of reducing the overall cancer morbidity by nearly 50%. Although selenium treatment did not significantly

  16. Therapeutic potential of selenium and tellurium compounds: opportunities yet unrealised.

    PubMed

    Tiekink, Edward R T

    2012-06-07

    Despite being disparaged for their malodorous and toxic demeanour, compounds of selenium, a bio-essential element, and tellurium, offer possibilities as therapeutic agents. Herein, their potential use as drugs, for example, as anti-viral, anti-microbial, anti-inflammatory agents, etc., will be surveyed along with a summary of the established biological functions of selenium. The natural biological functions of tellurium remain to be discovered.

  17. Selenium toxicity: cause and effects in aquatic birds

    USGS Publications Warehouse

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

    2002-01-01

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

  18. An accurate determination of the surface energy of solid selenium

    NASA Astrophysics Data System (ADS)

    Guisbiers, G.; Arscott, S.; Snyders, R.

    2012-12-01

    Selenium is currently a key element for developing nano and micro-technologies. Nevertheless, the surface energy of solid selenium (γSe) reported in the literature is still questionable. In this work, we have measured γSe = 0.291 ± 0.025 J/m2 at 293 K using the sessile drop technique with different probe liquids, namely ethylene glycol, de-ionized water, mercury, and gallium. This value is in excellent agreement with theoretical predictions.

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

    SciTech Connect

    Ho, S.Y.

    1981-01-01

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

  20. Acute Selenium Toxicity Associated With a Dietary Supplement

    PubMed Central

    MacFarquhar, Jennifer K.; Broussard, Danielle L.; Melstrom, Paul; Hutchinson, Richard; Wolkin, Amy; Martin, Colleen; Burk, Raymond F.; Dunn, John R.; Green, Alice L.; Hammond, Roberta; Schaffner, William; Jones, Timothy F.

    2011-01-01

    Background Selenium is an element necessary for normal cellular function, but it can have toxic effects at high doses. We investigated an outbreak of acute selenium poisoning. Methods A case was defined as the onset of symptoms of selenium toxicity in a person within 2 weeks after ingesting a dietary supplement manufactured by “Company A,” purchased after January 1, 2008. We conducted case finding, administered initial and 90-day follow-up questionnaires to affected persons, and obtained laboratory data where available. Results The source of the outbreak was identified as a liquid dietary supplement that contained 200 times the labeled concentration of selenium. Of 201 cases identified in 10 states, 1 person was hospitalized. The median estimated dose of selenium consumed was 41 749 μg/d (recommended dietary allowance is 55 μg/d). Frequently reported symptoms included diarrhea (78%), fatigue (75%), hair loss (72%), joint pain (70%), nail discoloration or brittleness (61%), and nausea (58%). Symptoms persisting 90 days or longer included fingernail discoloration and loss (52%), fatigue (35%), and hair loss (29%). The mean initial serum selenium concentration of 8 patients was 751 μg/L (reference range, ≤125 μg/L). The mean initial urine selenium concentration of 7 patients was 166 μg/24 h (reference range, ≤55 μg/24 h). Conclusions Toxic concentrations of selenium in a liquid dietary supplement resulted in a widespread outbreak. Had the manufacturers been held to standards used in the pharmaceutical industry, it may have been prevented. PMID:20142570

  1. Selenium and human health implications in California's San Joaquin Valley.

    PubMed

    Fan, A M; Book, S A; Neutra, R R; Epstein, D M

    1988-01-01

    An evaluation was conducted on the human health impacts of elevated levels of selenium in the Kesterson National Wildlife Refuge and its surroundings in Merced County, California. Investigative activities of various agencies were summarized and assessed. Agricultural waste water not intended for human use showed elevated selenium concentrations of up to 1400 ppb. Levels of selenium in fish (up to 96 ppm, wet weight), aquatic birds (up to 130 ppm in liver, dry weight), and waterfowl (up to 5.3 ppm flesh, wet weight) were unsafe for unrestricted human consumption. Data on selenium in drinking water (less than 10 ppb), animals (mean values: beef liver 0.3-0.35 ppm, wet weight; milk, 0.01-0.02 ppm), and air (particulate, 14.8 ng/m3; gaseous, less than 1080 ng/m3) did not suggest a high level of exposure. Selenium concentrations in soil were highly variable and suggested a potential source of high exposure. Selenium values in blood and urine of workers were within normal range. A community health survey did not show any trend of adverse health effects in the local population.

  2. Selenium concentrations of selected medicinal and aromatic plants in Turkey.

    PubMed

    Ozkutlu, Faruk; Sekeroglu, Nazim; Koca, Ufuk; Yazici, Gizem

    2011-10-01

    Recent scientific studies have proven the importance of trace elements on human health. The main food supplies are plants and animals, which are significant sources of these minerals. Studies on determining mineral compositions of herbs, spices and some other crops have increased all over the world. Published works revealed that spices, herbs and medicinal plants should be consumed to obtain beneficial trace elements. Selenium (Se), one of the most vital trace elements, has a significant role in human diet acting as a preventative agent against some serious illnesses. Despite numerous scientific works on mineral compositions of medicinal and aromatic plants, investigations of selenium content in these foods could not be successfully studied until recently due to the lack of suitable analytical methods for selenium analysis. Thus, publications on selenium concentrations of foods are recent. In this regard, selenium contents of some medicinal and aromatic plants commonly used as spices, herbal teas and traditional medicines in Turkey were studied in the present research. Selenium contents of the most used parts of these plants were analyzed by ICP-OES (Varian Vista-Pro, Australia). Of the analyzed 26 medicinal and aromatic plants, the highest Se concentration (1133 microg kg-1) was found in sweet basil (Ocimum basilicum L.) and the lowest in sumac (Rhus coriaria L.) fruits (11 microg kg(-1)).

  3. Hepatic metabolite profiles in mice with a suboptimal selenium status.

    PubMed

    Geillinger, Kerstin E; Rathmann, Daniel; Köhrle, Josef; Fiamoncini, Jarlei; Daniel, Hannelore; Kipp, Anna P

    2014-09-01

    Selenium is an essential trace element and mediates its functions via various selenoproteins such as glutathione peroxidases or thioredoxin reductases. A suboptimal selenium supply causes metabolic disturbances and is associated with an increased risk to develop different disorders, including cancer or cardiovascular diseases. This study aimed to assess the impact of a suboptimal selenium status on the hepatic metabolome of male mice analyzed by a targeted liquid chromatography/tandem mass spectrometry and a method based on non-targeted gas chromatography hyphenated with mass spectrometry. Feeding animals a diet with about half of the recommended selenium content supplied as selenomethionine caused liver glutathione peroxidase and thioredoxin reductase activities to decline and lipid peroxidation to increase. Serum T3 thyroid hormone concentration also declined via a reduced hepatic deiodinase activity. Metabolite profiling revealed predominantly changes in cysteine and carbon-1 metabolism as well as in selected lipid subclasses. In particular the concentrations of palmitoylcarnitines and oleoylcarnitines (C18:1 and C16:1) and various phosphatidylcholine species containing saturated fatty acids were elevated. Increased taurine levels suggested an enhanced cysteine flux through the salvage pathway whereas increased homocysteine levels appeared to be a consequence of a massive down-regulation of cystathionine β lyase (cystathionine β synthase) and a reduced flux through the transsulfuration pathway. The findings demonstrate that a suboptimal selenium status causes alterations in lipid and carbon-1 metabolism in mouse liver. These changes may contribute to the development of diseases associated with a suboptimal selenium status.

  4. 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).

  5. Selenium in the Blackfoot, Salt, and Bear River Watersheds

    USGS Publications Warehouse

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

    2005-01-01

    Nine stream sites in the Blackfoot River, Salt River, and Bear River watersheds in southeast Idaho, USA were sampled in May 2001 for water, surficial sediment, aquatic plants, aquatic invertebrates, and fish. Selenium was measured in these aquatic ecosystem components, and a hazard assessment was performed on the data. Water quality characteristics such as pH, hardness, and specific conductance were relatively uniform among the nine sites. Of the aquatic components assessed, water was the least contaminated with selenium because measured concentrations were below the national water quality criterion of 5 ??g/L at eight of the nine sites. In contrast, selenium was elevated in sediment, aquatic plants, aquatic invertebrates, and fish from several sites, suggesting deposition in sediments and food web cycling through plants and invertebrates. Selenium was elevated to concentrations of concern in fish at eight sites (> 4 ??g/g in whole body). A hazard assessment of selenium in the aquatic environment suggested a moderate hazard at upper Angus Creek (UAC) and Smoky Creek (SC), and high hazard at Little Blackfoot River (LiB), Blackfoot River gaging station (BGS), State Land Creek (SLC), upper (UGC) and lower Georgetown Creek (LGC), Deer Creek (DC), and Crow Creek (CC). The results of this study indicate that selenium concentrations from the phosphate mining area of southeast Idaho were sufficiently elevated in several ecosystem components to cause adverse effects to aquatic resources in southeastern Idaho. ?? Springer Science + Business Media, Inc. 2005.

  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. Trace nutrients. Selenium in British food.

    PubMed

    Thorn, J; Robertson, J; Buss, D H; Bunton, N G

    1978-03-01

    1. The amount of selenium in nationally representative samples of prepared and cooked groups of foods, and in a variety of raw individual foods, was determined fluorimetrically. 2. The average British diet was calculated to provide approximately 60 microgram Se/d, of which half was derived from cereals and cereal products and another 40% from meat and fish. Milk, table fats, fruit and vegetables provided little or no Se. 3. Individual foods which were particularly rich in Se (greater than 0.2 mg/kg) included 'bread-making' and wholemeal flours, kidney, fatty fish, brazil nuts (Bertholletia excelsa) and several other varieties of nut. In contrast, breast milk and other foods for babies (except some cereal products) contained little Se. 4. The total intake, and the amounts of Se in major foods, were lower than in most other studies. This is probably the result of the comparatively low levels of this element in British soil.

  8. [Selenium and cancer: from prevention to treatment].

    PubMed

    Brozmanová, J

    2011-01-01

    Selenium (Se) is an essential dietary component for all animals, including human beings, that is regarded as a protective agent against cancer. Although the mode of its anticancer action is not yet fully understood, several mechanisms, such as antioxidant protection through selenoenzymes, stimulation of DNA repair, and apoptosis in tumor prestages have all been proposed. Despite the unsupported results of the last "SELECT" trial, the cancer-preventing activity of Se has been demonstrated in a majority of epidemiological studies. Moreover, recent studies suggest that Se has a potential to be used not only in cancer prevention but also in cancer treatment, where in combination with other anticancer drugs or radiation it may increase the efficacy of cancer therapy. In combating cancer cells, Se acts as a prooxidant rather than an antioxidant, inducing apoptosis through the generation of oxidative stress. Thus, inorganic Se compounds, having high redox potency, represent a promising option in cancer therapy.

  9. Lithium ion beam impact on selenium nanowires

    NASA Astrophysics Data System (ADS)

    Panchal, Suresh; Chauhan, R. P.

    2017-03-01

    This study is structured on Li3+ ion irradiation effect on the different properties of selenium (Se) nanowires (NW's) (80 nm). Template technique was employed for the synthesis of Se nanowires. Exploration of the effect of 10 MeV Li3+ ions on Se NW's was done for structural and electrical analysis with the help of characterization tools. X-ray diffraction revealed the variation in peak intensity only, with no peak shifting. The grain size and texture coefficients of various planes were also found to vary. Current-Voltage characteristics (IVC) show an increment in the conductivity up to a fluence of 1×1012 ions/cm2 and a decrease at the next two fluences. The effects of irradiation are presented in this paper and possible reasons for the variation in properties are also discussed in this study.

  10. 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.

  11. Intraruminal selenium pellet for control of nutritional muscular dystrophy in cattle.

    PubMed

    Hidiroglou, M; Proulx, J; Jolette, J

    1985-01-01

    Administration of an intraruminal selenium pellet to a herd of pregnant crossbred cows was evaluated for controlling nutritional muscular dystrophy in an area of northern Ontario with numerous losses of calves. Cows were winter-fed grass silage. Each spring cows and calves went to pasture. A single dose of intraruminal selenium pellet was given to 80 cows during last 3 mo of pregnancy the 1st yr only while the remaining 80 were controls. During 3 consecutive years, efficacy of intraruminal selenium pellet was evaluated by selenium status of recipient cows and their offspring as well by the incidence of nutritional muscular dystrophy. Selenium in plasma, as well as glutathione peroxidase in whole blood, in the cows administered intraruminal selenium pellet, were higher than in the deficient controls. Ten months after intraruminal selenium pellet treatment, selenium in tissues was higher in treated than in untreated cows but within normal ranges. Before cows were turned out to pasture the 1st yr, milk selenium of intraruminal selenium pellet cows were higher than controls. This technique of selenium dosing was effective in raising the selenium status of the progeny. There was no evidence of nutritional muscular dystrophy in calves from selenium-dosed cows, while 15 calves born of the untreated cows showed clinical symptoms of nutritional muscular dystrophy.

  12. [Placental weight percentiles and its relationship with fetal weight according to gestational age in an urban area of Buenos Aires].

    PubMed

    Grandi, Carlos; Roman, Estela; Dipierri, Jose

    2015-01-01

    Antecedentes: El peso placentario (PP) y los índices de su relación con el peso al nacer (PN) (PN/PP, PP/PN) predicen morbi-mortalidad perinatal y resultados alejados de la salud. Objetivos: Calcular percentilos del PP e índices por sexo y edad gestacional correspondientes a 867 RNV de la Maternidad Sardá de Buenos Aires, Argentina y compararlos con referencias internacionales. Material y métodos: Se excluyeron feto muerto, embarazo múltiple, edad gestacional <22 y >42 semanas y PP<100g y >2500g. Características maternas y fetales: edad, educación, tabaco, paridad, diabetes, preeclampsia, corioamnionitis, restricción del crecimiento, malformación congénita y prematurez. Se calcularon estadísticos de resumen y percentilos con el método LMS. Las comparaciones se realizaron con test t-Student, ANOVA y referencias internacionales. Resultados: Edad materna media 24 años, educación 10.1 años, 24.5% primíparas, 12.6% fumadoras, 4.9% presentaron diabetes, 8.7% preeclampsia, 7.9% corioamnionitis y 13.0% restricción del crecimiento fetal. El 55.3% de los RN fueron varones, 51.6% prematuros, 18.9% PEG y 7.1% malformados. El PN y EG promedio fue de 2581g y 35.6 semanas respectivamente. Elevada correlación positiva de la EG con PP y PN/PP y negativa con PP/PN (p%lt;0.001); el peso de la placenta e índices fueron mayores en varones. Se presentan los percentiles de PP, PN/PP y PP/PN. Las diferencias con las referencias oscilaron de 0.46% -13%, 4.91% -12.1% y 5.81% -14% para el PP, PN/PP y PP/PN respectivamente. Conclusiones: los percentilos generados son aplicables en investigaciones sobre la relación de la placenta con resultados perinatales y la salud durante el ciclo vital.

  13. 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

  14. 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

  15. Selenium and vitamin E for prostate cancer: post-SELECT (Selenium and Vitamin E Cancer Prevention Trial) status.

    PubMed

    Ledesma, Mark C; Jung-Hynes, Brittney; Schmit, Travis L; Kumar, Raj; Mukhtar, Hasan; Ahmad, Nihal

    2011-01-01

    Various formulations of selenium and vitamin E, both essential human dietary components, have been shown to possess a therapeutic and preventive effect against prostate cancer. Fortuitous results of clinical trials also implied a risk-reduction effect of selenium and vitamin E supplements. The Selenium and Vitamin E Cancer Prevention Trial (SELECT), using oral selenium and vitamin E supplementation in disease-free volunteers, was designed to test a prostate cancer chemoprevention hypothesis. SELECT was terminated early because of both safety concerns and negative data for the formulations and doses given. Here, we review and discuss the studies done before and since the inception of SELECT, as well as the parameters of the trial itself. We believe that there is a lack of appropriate in vivo preclinical studies on selenium and vitamin E despite many promising in vitro studies on these agents. It seems that the most effective doses and formulations of these agents for prostate cancer chemoprevention have yet to be tested. Also, improved understanding of selenium and vitamin E biology may facilitate the discovery of these doses and formulations.

  16. Effect of foliar application of selenium on the antioxidant activity of aqueous and ethanolic extracts of selenium-enriched rice.

    PubMed

    Xu, Juan; Hu, Qiuhui

    2004-03-24

    Selenium fertilizer was foliar applied to determine the effects of antioxidant activity of selenium-enriched rice assessed by alpha,alpha-diphenyl-beta-picylhydrazyl (DPPH) radical scavenging and the ferric thiocyanate (FTC) method. Results showed that selenium concentration in rice was significantly enhanced dose dependently. Aqueous or ethanolic extracts of rice displayed significantly higher antioxidant activity against lipid peroxidation. The activities of aqueous extracts were significantly higher than those of ethanolic extracts and increased with the increasing selenium concentration in rice. The DPPH assay showed that the kinetic behaviors of aqueous extracts were complex and slow, while ethanolic extracts reacted quickly with DPPH radical. Aqueous extracts of rice exhibited higher antiradical efficiencies than ethanolic extracts, and rice (1.275 mg Se kg(-)(1)) presented the lowest EC(50) values of 533.46 +/- 0.58 microg mL(-)(1). As compared to rice extracts, all of the reference antioxidants showed more than 4-fold antiradical efficiencies than rice extracts. This radical scavenging activity was significantly correlated with selenium concentrations in rice (R = 0.862, p < 0.05), while ethanolic extracts were inversely correlated with selenium concentration in rice.

  17. Comparison of changes in growth percentiles of US children on CDC 2000 growth charts with corresponding changes on WHO 2006 growth charts.

    PubMed

    Mei, Zuguo; Grummer-Strawn, Laurence M

    2011-05-01

    Longitudinal data with 37 964 length and weight measurements from 10 844 children who participated in the California Child Health and Development Study was used to compare the proportion of children aged ≤24 months who crossed major percentile lines on the Centers for Disease Control and Prevention (CDC) 2000 growth charts with the percentage who crossed corresponding lines on the World Health Organization (WHO) 2006 growth charts. Percentage of children aged ≤24 months who crossed at least 2 major percentile lines for length-for-age, weight-for-age, and weight-for-length according to CDC 2000 charts were compared with the percentage who did so according to WHO 2006 charts. The results from this analysis suggest that pediatricians who monitor children's growth on the basis of WHO 2006 growth charts may be more likely to refer children aged <6 months and less likely to refer those aged 6 to 12 months for further evaluation for failure to thrive.

  18. Sedimentary selenium as a causal factor for adverse biological effects: Toxicity thresholds and stream modeling

    SciTech Connect

    Va Derveer, W.; Canton, S.

    1995-12-31

    Selenium (Se) in the aquatic environment exhibits a strong association with particulate organic matter and as a result, measurements of waterborne concentration can be an unreliable predictor of bioaccumulation and adverse effects. Particulate-bound Se, typically measured as sedimentary Se, has been repeatedly implicated as a causal factor for Se bioaccumulation and subsequent potential for reproductive failures in fish and/or birds at sites receiving coal-fired power plant and refinery effluents as well as irrigation drainage. In fact, the premise that adverse biological effects are largely induced by sedimentary Se satisfies all of Hill`s criteria for a causal association. Despite these findings, most efforts to control Se continue to focus on waterborne concentrations because sedimentary toxicity thresholds are largely unknown. Sedimentary Se and associated biological effects data from studies of Se-bearing industrial effluent and irrigation drainage were compiled to initiate development of biological effects thresholds, The probability of adverse effects on fish or birds appears to be low up to a sedimentary Se concentration of about 2.8 {micro}g/g dry weight and high at 6.4 {micro}g/g dry weight (10th and 50th percentile of effects data, respectively). In addition, a preliminary regression model was derived for predicting dissolved to sedimentary Se transfer in streams as an interactive function of site-specific sedimentary organic carbon content (R{sup 2} = 0,870, p < 0.001) based on irrigation drainage studies in Colorado. This dissolved Se interaction with sedimentary organic carbon provides a possible explanation for the variable biological response to waterborne Se-organic-rich sites are predisposed to greater Se bioaccumulation and subsequent biological effects than organic-poor sites.

  19. Selenium and Vitamin E Cancer Prevention Trial (SELECT): Questions and Answers

    MedlinePlus

    ... Research Selenium and Vitamin E Cancer Prevention Trial (SELECT): Questions and Answers On This Page What is ... supplement in SELECT prevent prostate cancer? What is SELECT? SELECT stands for the Selenium and Vitamin E ...

  20. 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.)

  1. 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)

  2. Vitamin E, Selenium Supplements Won't Curb Men's Dementia Risk

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_164174.html Vitamin E, Selenium Supplements Won't Curb Men's Dementia ... 20, 2017 (HealthDay News) -- A daily dose of vitamin E or selenium supplements won't keep dementia ...

  3. 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...

  4. Biological and chemical investigation of Allium cepa L. response to selenium inorganic compounds.

    PubMed

    Michalska-Kacymirow, M; Kurek, E; Smolis, A; Wierzbicka, M; Bulska, E

    2014-06-01

    The aim of this study was to evaluate the biological and chemical response of Allium cepa L. exposed to inorganic selenium compounds. Besides the investigation of the total content of selenium as well as its chemical speciation, the Allium test was used to evaluate the growth of onion roots and mitotic activity in the roots' meristem. The total content of selenium was determined by inductively coupled plasma mass spectrometry (ICP MS). High-performance liquid chromatography (HPLC), coupled to ICP MS, was used for the selenium chemical speciation. Results indicated that A. cepa plants are able to biotransform inorganic selenium compounds into their organic derivatives, e.g., Se-methylselenocysteine from the Se(IV) inorganic precursor. Although the differences in the biotransformation of selenium are due mainly to the oxidation state of selenium, the experiment has also shown a fine effect of counter ions (H(+), Na(+), NH4 (+)) on the response of plants and on the specific metabolism of selenium.

  5. Selenium Concentrations in Irrigation Drain Inflows to the Salton Sea, California, October 2006 and January 2007

    USGS Publications Warehouse

    May, Thomas W.; Walther, Mike W.; Brumbaugh, William G.

    2007-01-01

    This report presents raw data on selenium concentrations in samples of water, sediment, detritus, and selected food-chain matrices collected from selected agricultural drains in the southern portion of the Salton Sea during October 2006 and January 2007. Total selenium and selenium species were determined in water samples, whereas total selenium was determined in sediment, detritus, algae, plankton, midge larvae (Family Chironomidae), and two fish species (western mosquitofish, Gambusia affinis, and sailfin molly, Poecilia latipinna).

  6. Selenium toxicity in breeding ring-necked pheasants (Phasianus colchicus).

    PubMed

    Latshaw, J D; Morishita, T Y; Sarver, C F; Thilsted, J

    2004-12-01

    A flock of breeding ring-necked pheasants received feed with a high selenium content. Within 4 days of eating the toxic feed, the rate of egg production began to decrease, and bird aggression increased. Approximately 12% of the hens died within a week. Necropsy of the hens revealed colorless fluid around the heart and a friable, but otherwise normal, liver. The rapid onset of the problem and signs noted at necropsy suggested toxicosis. Based on analysis, the feed contained 9.3 ppm of selenium. Selenium toxicity was consistent with the histologic diagnosis of degenerative cardiomyopathy, vacuolar degeneration of hepatocytes, and centrilobular hepatic necrosis. After 8 days, the toxic feed was removed and replaced with fresh feed. Egg production, which had dropped to 50%, returned to normal within 10 days of feed replacement. Hatchability of eggs laid from days 8 to 14 after delivery of the toxic feed was 35%. Approximately 10% of the chicks that hatched had deformed beaks and abnormal eyes. Many of the chicks that died in the shell had deformities, bringing the total to more than 50% of all embryos that developed. The selenium content of eggs that had no embryonic development was 2.05 ppm. Hatchability of eggs laid from days 21 to 28 after the toxic feed was delivered was almost 80%, which was slightly lower than normal. The selenium content of these eggs was 0.30 ppm. These results show the rapid onset and correction of selenium toxicity and suggest that specific embryologic defects are diagnostic for selenium toxicity.

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

    USGS Publications Warehouse

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

    1987-01-01

    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.

  8. 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

  9. Toxicity of organic selenium in the diet to chinook salmon

    USGS Publications Warehouse

    Hamilton, Steven J.; Buhl, Kevin J.; Faerber, Neil L.; Bullard, Fern A.; Wiedmeyer, Raymond H.

    1990-01-01

    The toxicity of two organoselenium diets was evaluated in 90- to 120-d partial life cycle tests with two life stages of chinook salmon (Oncorhynchus tshawytscha Walbaum). One of the diets contained fish meal made from high-selenium mosquitofish (Gambusia affinis Baird and Girard) collected from the selenium-laden San Luis Drain, California (here termed SLD diet) and the other contained meal made from low-selenium mosquitofish (collected from a reference site) fortified with selenomethionine. A 90-d study was conducted with swim-up larvae in a water-simulating dilution of San Luis Drain water in a standardized fresh water; and a 120-d study was conducted with fingerlings 70-mm long in a water of similar quality but prepared with a standardized brackish water. After 90 d of exposure in the freshwater study, survival was reduced in fish fed ≥9.6 μg Se/g of either diet, and growth was reduced in fish fed ≥5.3 μg Se/g of SLD diet or ≥18.2 μg Se/g of selenomethionine diet. Reduced fish growth, whole-body concentrations of selenium and survival were strongly correlated to concentrations of selenium in both diets. After 120 d of exposure in the brackish-water study, survival was unaffected but growth was reduced in fish fed ≥18.2 μg Se/g of SLD diet or 35.4 μg Se/g of selenomethionine diet. After 120 d of dietary exposure, survival during a 10-d seawater challenge test was reduced in fish fed 35.4 μg Se/g of either diet. In this second dietary study, concentration—response relations were observed in both dietary treatments between the dietary concentrations of selenium and all three characteristics — fish growth, whole-body concentrations of selenium and survival in seawater.

  10. Molybdenum accumulation, tolerance and molybdenum-selenium-sulfur interactions in Astragalus selenium hyperaccumulator and nonaccumulator species.

    PubMed

    DeTar, Rachael Ann; Alford, Élan R; Pilon-Smits, Elizabeth A H

    2015-07-01

    Some species hyperaccumulate selenium (Se) upwards of 0.1% of dry weight. This study addressed whether Se hyperaccumulators also accumulate and tolerate more molybdenum (Mo). A field survey revealed on average 2-fold higher Mo levels in three hyperaccumulator Astragali compared to three nonaccumulator Astragali, which were not significantly different. Next, a controlled study was performed where hyperaccumulators Astragalus racemosus and Astragalus bisulcatus were compared with nonaccumulators Astragalus drummondii and Astragalus convallarius for Mo accumulation and tolerance, alone or in the presence of Se. When grown on agar media with 0, 12, 24 or 48 mg L(-1) molybdate and/or 0, 1.6 or 3.2 mg L(-1) selenate, all species decreased in biomass with increasing Mo supply. Selenium did not impact biomass at the supplied levels. All Astragali accumulated Mo upwards of 0.1% of dry weight. Selenium levels were up to 0.08% in Astragalus racemosus and 0.04% Se in the other species. Overall, there was no correlation between Se hyperaccumulation and Mo accumulation capacity. However, the hyperaccumulators and nonaccumulators differed in some respects. While none of the species had a higher tissue Mo to sulfur (S) ratio than the growth medium, nonaccumulators had a higher Mo/S ratio than hyperaccumulators. Also, while molybdate and selenate reduced S accumulation in nonaccumulators, it did not in hyperaccumulators. Furthermore, A. racemosus had a higher Se/S ratio than its medium, while the other species did not. Additionally, Mo and Se treatment affected S levels in nonaccumulators, but not in hyperaccumulators. In conclusion, there is no evidence of a link between Se and Mo accumulation and tolerance in Astragalus. Sulfate transporters in hyperaccumulating Astragali appear to have higher sulfate specificity over other oxyanions, compared to nonaccumulators, and A. racemosus may have a transporter with enhanced selenate specificity relative to sulfate or molybdate.

  11. 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.

  12. 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.

  13. 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

  14. Selenium concentration and speciation in biofortified flour and bread: Retention of selenium during grain biofortification, processing and production of Se-enriched food.

    PubMed

    Hart, D J; Fairweather-Tait, S J; Broadley, M R; Dickinson, S J; Foot, I; Knott, P; McGrath, S P; Mowat, H; Norman, K; Scott, P R; Stroud, J L; Tucker, M; White, P J; Zhao, F J; Hurst, R

    2011-06-15

    The retention and speciation of selenium in flour and bread was determined following experimental applications of selenium fertilisers to a high-yielding UK wheat crop. Flour and bread were produced using standard commercial practices. Total selenium was measured using inductively coupled plasma-mass spectrometry (ICP-MS) and the profile of selenium species in the flour and bread were determined using high performance liquid chromatography (HPLC) ICP-MS. The selenium concentration of flour ranged from 30ng/g in white flour and 35ng/g in wholemeal flour from untreated plots up to >1800ng/g in white and >2200ng/g in wholemeal flour processed from grain treated with selenium (as selenate) at the highest application rate of 100g/ha. The relationship between the amount of selenium applied to the crop and the amount of selenium in flour and bread was approximately linear, indicating minimal loss of Se during grain processing and bread production. On average, application of selenium at 10g/ha increased total selenium in white and wholemeal bread by 155 and 185ng/g, respectively, equivalent to 6.4 and 7.1μg selenium per average slice of white and wholemeal bread, respectively. Selenomethionine accounted for 65-87% of total extractable selenium species in Se-enriched flour and bread; selenocysteine, Se-methylselenocysteine selenite and selenate were also detected. Controlled agronomic biofortification of wheat crops for flour and bread production could provide an appropriate strategy to increase the intake of bioavailable selenium.

  15. Relationship of selenium concentrations in blood of calves to blood selenium of the dam and supplemental selenium

    SciTech Connect

    Kincaid, R.L.; Hodgson, A.S. )

    1989-01-01

    Selenium status of dam, injected Se, and dietary Ca on calf blood Se concentrations were determined in two trials. Blood was collected from heifer calf and dam pairs at parturition. Half of the calves were injected intramuscularly with .0825 mg Se/kg body weight at birth while the other half received no Se injection. The concentration of Se in the blood of the dam had a significant effect on blood Se of calves at wk 0, 1, and 3, whereas injected Se did not significantly affect blood Se concentrations in the calf until wk 10. In a separate trial, whole blood and plasma Se were significantly correlated at birth in calves, but plasma Se was only about one-third the concentration of whole blood. The concentration of dietary Ca in the calf starter did not significantly affect blood Se, but a quadratic relationship was suggested. Plasma Zn in calves was elevated at birth and then declined with age whereas plasma inorganic P increased with age. Early postnatal concentrations of Se in blood of calves are largely a function of the dam; thus, in areas of low Se intakes, Se supplements for the dam are important.

  16. 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

  17. 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

  18. 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.

  19. Effect of selenium supplementation on spermatogenic cells of goats.

    PubMed

    Ganabadi, S; Halimatun, Y; Amelia Choong, K L; Nor Jawahir, A; Mohammed Hilmi, A

    2010-04-01

    Selenium is an essential trace mineral that is required for many physiological functions in animals and the potential relevance of selenium to the reproductive system of livestock has been considered by many researchers. The objective of this study was to examine the effect of selenium supplementation on the spermatogenic cells of goat. Eight young male crossbred (Katjang x Boer) goats, aged between 9 to 11 months, were used in this study. The control group (CON; n = 4) was fed with a diet consisting of 60% Guinea grass and 40% concentrates while the treatment group (Se-SUP; n = 4) was fed with the same diet as the goats in the control group but with supplementation of 0.6mg selenium (sodium selenite powder) per goat daily for 100 days and were slaughtered on the 101st day. There were no significant differences (p>0.05) in the mean number of spermatogonium, spermatocytes, spermatozoa and the total number of spermatogenic cells between the CON and Se-SUP goat respectively. However, there was a significant increase (p< 0.05) of spermatid in Se-SUP goats. The mean percentage of spermatids was significantly increased (p< 0.05) while spermatozoa was significantly decreased (p< 0.05) in Se-SUP goats. In conclusion, selenium supplementation increased the percentages of spermatids and decreased the percentages of spermatozoa in the seminiferous tubules in goats.

  20. Selenium in blood, semen, seminal plasma and spermatozoa of stallions and its relationship to sperm quality.

    PubMed

    Bertelsmann, H; Keppler, S; Höltershinken, M; Bollwein, H; Behne, D; Alber, D; Bukalis, G; Kyriakopoulos, A; Sieme, H

    2010-01-01

    The essential trace element selenium is indispensable for male fertility in mammals. Until now, little data existed regarding the relationship between selenium and sperm quality in the stallion. Selenium, or selenium-dependent glutathione peroxidase activity, was determined in red blood cells, semen, seminal plasma and spermatozoa, and the percentages of spermatozoa with progressive motility (PMS), intact membranes (PMI), altered (positive) acrosomal status (PAS) and detectable DNA damage, determined by the sperm chromatin structure assay, were evaluated in 41 healthy stallions (three samples each). The pregnancy rate per oestrus cycle (PRC) served as an estimation of fertility. An adverse effect on stallion fertility caused by low dietary selenium intake was excluded, as all stallions had sufficient selenium levels in their blood. Interestingly, no significant correlations (P > 0.05) between the selenium level in blood and the selenium level in seminal plasma or spermatozoa were found, suggesting that the selenium level in blood is no indicator of an adequate selenium supply for spermatogenesis. The selenium level in spermatozoa (nmol billion(-1)) was correlated with PMI, PMS and PAS (r = 0.40, r = 0.31 and r = -0.42, respectively; P selenium concentration in spermatozoa (nmol g(-1)) was correlated with PRC (r = 0.40, P < 0.03). The results of the present study show that the determination of an adequate selenium status for the male equine reproduction requires the analysis of selenium in spermatozoa. Furthermore, selenium is associated with improved sperm quality and fertility in the stallion.

  1. Non-linear uptake and hormesis effects of selenium in red-winged blackbirds (Agelaius phoeniceus).

    PubMed

    Harding, Lee E

    2008-01-25

    Effects of selenium on reproductive success were assessed in red-winged blackbirds (Agelaius phoeniceus). Mean egg selenium (MES) ranged from 2.96 to 21.7 mg/kg dry weight with individual eggs up to 40 mg/kg. Uptake was non-linear: increments in MES declined as aqueous selenium increased; the asymptote was approximately 23 mg/kg. Eggs were heavier and more were laid in 2004 compared to 2005, a year of record rainfall and below-normal temperatures. Mortality of embryos that were incubated to full term was low (2.6% in 2004 and 3.2% in 2005), as was the prevalence of embryonic defects (2.7% in 2004 and 5.1% in 2005). Abnormalities in nestlings were also rare. Egg mortality was caused by predation, weather, and parental abandonment. Nestlings died from predation, starvation, and hypothermia associated with rain and cold, drowning, and bacterial infections. Nestling liver concentrations reached 81 mg/kg dry wt. selenium and were highest at the most highly selenium-exposed sites. Blood glutathione peroxidase (a selenium-dependent enzyme indicative of selenium exposure) was unrelated to liver selenium concentrations, egg selenium, or ambient selenium exposure. The selenium concentration in prey that parents fed to nestlings was higher at the selenium-exposed sites (up to 37 mg/kg dry wt. Se) compared to reference sites. Aqueous selenate:selenite ratios were related to redox differences and were much higher at the site with the highest MES, liver selenium, and prey item selenium concentrations. Hatchability showed U-shaped, or hormesis, relationships with MES: productivity increased with selenium concentrations at low exposures and decreased at high exposures. The effects threshold was approximately 22 mg/kg dry wt. MES.

  2. Chemical characterisation and speciation of organic selenium in cultivated selenium-enriched Agaricus bisporus.

    PubMed

    Maseko, Tebo; Callahan, Damien L; Dunshea, Frank R; Doronila, Augustine; Kolev, Spas D; Ng, Ken

    2013-12-15

    The selenium concentration in Agaricus bisporus cultivated in growth compost irrigated with sodium selenite solution increased by 28- and 43-fold compared to the control mushroom irrigated solely with water. Selenium contents of mushroom proteins increased from 13.8 to 60.1 and 14.1 to 137 μgSe/g in caps and stalks from control and selenised mushrooms, respectively. Selenocystine (SeCys; detected as [SeCys]2 dimer), selenomethionine (SeMet), and methyl-selenocysteine (MeSeCys) were separated, identified and quantified by liquid chromatography-electrospray ionisation-mass spectrometry from water solubilised and acetone precipitated proteins, and significant increases were observed for the selenised mushrooms. The maximum selenoamino acids concentration in caps and stalks of control/selenised mushrooms was 4.16/9.65 μg/g dried weight (DW) for SeCys, 0.08/0.58 μg/g DW for SeMet, and 0.031/0.10 μg/g DW for MeSeCys, respectively. The most notable result was the much higher levels of SeCys accumulated by A. bisporus compared to SeMet and MeSeCys, for both control and selenised A. bisporus.

  3. Effects of selenium source on measures of selenium status and immune function in horses.

    PubMed

    Montgomery, Julia B; Wichtel, Jeffrey J; Wichtel, Maureen G; McNiven, Mary A; McClure, J T; Markham, Fred; Horohov, David W

    2012-10-01

    The effects of selenium (Se) supplementation and source on equine immune function have not been extensively studied. This study examined the effects of oral Se supplementation and Se source on aspects of innate and adaptive immunity in horses. Fifteen horses were assigned to 1 of 3 groups (5 horses/group): control, inorganic Se (sodium selenite), organic Se (Se yeast). Immune function tests performed included: lymphocyte proliferation in response to mitogen concanavalin A, neutrophil phagocytosis, antibody production after rabies vaccination, relative cytokine gene expression in stimulated lymphocytes [interferon gamma (IFNγ), interleukin (IL)-2, IL-5, IL-10, tumor necrosis factor alpha (TNFα)], and neutrophils (IL-1, IL-6, IL-8, IL-12, TNFα). Plasma, red blood cell Se, and blood glutathione peroxidase activity were measured. Plasma and red blood cell Se were highest in horses in the organic Se group, compared with that of inorganic Se or control groups. Organic Se supplementation increased the relative lymphocyte expression of IL-5, compared with inorganic Se or no Se. Selenium supplementation increased relative neutrophil expression of IL-1 and IL-8. Other measures of immune function were unaffected. Dietary Se content and source appear to influence immune function in horses, including alterations in lymphocyte expression of IL-5, and neutrophil expression of IL-1 and IL-8.

  4. Stability of total selenium and selenium species in lyophilised oysters and in their enzymatic extracts.

    PubMed

    Moreno, P; Quijano, M A; Gutiérrez, A M; Pérez-Conde, M C; Cámara, C

    2002-10-01

    To obtain reliable information on speciation analysis it is necessary to previously evaluate the stability of the species in the sample of interest. Furthermore, in those cases in which sample treatment to extract the species is time-consuming, an evaluation of how to maintain species integrity in the extracts is paramount. Thus, the present paper reports the stability of total Se, SeMet and TMSe+ in freeze-dried oyster and in the enzymatic extracts stored in Pyrex and polyethylene containers at different temperatures (-18, 4 and 20 degrees C). Total selenium determinations and Se speciation were carried out by HG-AAS after acid digestion in a microwave oven and by on-line coupling of cation exchange HPLC-ICP-MS after enzymatic hydrolysis, respectively. The results obtained for the freeze-dried sample showed that total Se and the selenium species evaluated are stable for at least 12 months, under all the conditions tested. However, Se species in the enzymatic extracts are only stable for 10 days if stored at 4 degrees C in Pyrex containers. These results show that the extracts do not necessarily have to be analysed just after sample treatment.

  5. Chemical Form and Distribution of Selenium and Sulfur in the Selenium Hyperaccumulator Astragalus bisulcatus1

    PubMed Central

    Pickering, Ingrid J.; Wright, Carrie; Bubner, Ben; Ellis, Danielle; Persans, Michael W.; Yu, Eileen Y.; George, Graham N.; Prince, Roger C.; Salt, David E.

    2003-01-01

    In its natural habitat, Astragalus bisulcatus can accumulate up to 0.65% (w/w) selenium (Se) in its shoot dry weight. X-ray absorption spectroscopy has been used to examine the selenium biochemistry of A. bisulcatus. High concentrations of the nonprotein amino acid Se-methylseleno-cysteine (Cys) are present in young leaves of A. bisulcatus, but in more mature leaves, the Se-methylseleno-Cys concentration is lower, and selenate predominates. Seleno-Cys methyltransferase is the enzyme responsible for the biosynthesis of Se-methylseleno-Cys from seleno-Cys and S-methyl-methionine. Seleno-Cys methyltransferase is found to be expressed in A. bisulcatus leaves of all ages, and thus the biosynthesis of Se-methylseleno-Cys in older leaves is limited earlier in the metabolic pathway, probably by an inability to chemically reduce selenate. A comparative study of sulfur (S) and Se in A. bisulcatus using x-ray absorption spectroscopy indicates similar trends for oxidized and reduced Se and S species, but also indicates that the proportions of these differ significantly. These results also indicate that sulfate and selenate reduction are developmentally correlated, and they suggest important differences between S and Se biochemistries. PMID:12644695

  6. Selenium-fortified wheat: potential of microbes for biofortification of selenium and other essential nutrients.

    PubMed

    Yasin, Muhammad; El-Mehdawi, Ali Farag; Pilon-Smits, Elizabeth A H; Faisal, Muhammad

    2015-01-01

    Selenium (Se) is an essential micronutrient for humans and animals, and Se deficiency is a worldwide problem. Plants are a main dietary source of Se for humans and livestock. In this study we investigated the effect of two selenium-tolerant bacterial strains Bacillus cereus-YAP6 and Bacillus licheniformis-YAP7, on the growth and Se uptake by wheat plants. The bacteria-inoculated plants exhibited a significant increase in spike length, shoot length and dry biomass. Inoculated Se-treated plants also showed increased stem Se, S, Ca and Fe concentrations, by up to 375%, 40%, 55%, and 104%, respectively, and increased kernel Se, S, Ca and Fe concentrations by up to 154%, 85%, 60%, and 240%, respectively, compared to un-inoculated Se-treated plants. In conclusion, inoculation with strains YAP6 andYAP7 is a good Se biofortification strategy for wheat. Both strains showed resistance to other toxic elements, i.e., As, Cd, Co, Cr, Cu, Mn and Zn. Optimal growth temperature and pH for both strains were 37°C and pH7, respectively, but both strains can grow very well at different temperatures (28-45°C) and at alkaline pH. Both strains have high Se reduction potential: strains YAP6 and YAP7 converted 92% and 32% of selenite into elemental Se within 48 h, respectively.

  7. Selenium status in soils in Yugoslavia.

    PubMed

    Jović, V

    1998-01-01

    In the last 8 years, a number of data on selenium (Se) content and distribution in the soil of Yugoslavia (Serbia and Montenegro) became available. The Se content of the soil in Yugoslavia varies in a broad range 39 to 440 microg/kg (mean value 230 microg/kg; n = 284). The soil clay fraction is rich in Se (range 146 to 586 microg/kg) in relation to sand and silt fractions. The available Se content (after extraction with ammonium acetate and EDTA) varies in the range of 1.2 to 28.2% of the total Se content. The speciation of Se is shown for the soils derived from volcanic rocks in Serbia. In addition, the influence of some soil properties on the Se content, as well as its content in the rocks, sediment, and wild plants in Yugoslavia, is discussed. The geographical distribution of Se in the soil of Yugoslavia shows that it is found in inadequate amounts in many agricultural regions. Its low content in soil has been thought to be associated with a higher incidence of some diseases. The Se content of the soil in Yugoslavia is not fully known. There is a great need to make a systematic geochemical mapping for Se and other trace elements in the soil.

  8. Volatilization of Selenium by Alternaria alternata

    PubMed Central

    Thompson-Eagle, E. T.; Frankenberger, W. T.; Karlson, U.

    1989-01-01

    Seleniferous water continues to be a serious problem to wildlife in the central valley of California. Water samples collected from Kesterson Reservoir, Peck Ranch, and Lost Hills evaporation pond facilities contained between 0.005 and 5 mg of Se per liter. The objective of this study was to isolate Se-methylating organisms in evaporation pond water and to assess, through enrichment and manipulation of their optimal growth parameters, the environmental factors which govern microbial Se methylation. Alternaria alternata was isolated as an active Se-methylating organism. The volatile product was identified as dimethylselenide. The effects of pH, temperature, Se substrates, and methyl donors on the ability of A. alternata to methylate Se were investigated in liquid medium containing 100 mg of Se per liter. The optimum pH and temperature for methylation were 6.5 and 30°C, respectively. Selenate and selenite were methylated more rapidly than selenium sulfide and various organic Se compounds (6-selenoguanosine, 6-selenoinosine, seleno-dl-methionine, and 6-selenopurine). l-Methionine and methyl cobalamine (0.1 μM) stimulated dimethylselenide production. This study demonstrates that Se-methylating organisms are present in evaporation pond water and are capable of liberating substantial quantities of Se in the volatile dimethylselenide form. By determining the optimum environmental conditions which stimulate volatilization, it may be possible to design a way to remove Se from seleniferous water in situ. PMID:16347933

  9. Whole blood selenium concentrations in endurance horses.

    PubMed

    Haggett, Emily; Magdesian, K Gary; Maas, John; Puschner, Birgit; Higgins, Jamie; Fiack, Ciara

    2010-11-01

    Exercise causes an increase in the production of reactive oxygen species, which can result in oxidant/antioxidant disequilibrium. Deficiency of antioxidants can further alter this balance in favor of pro-oxidation. Selenium (Se) is one of many antioxidant catalysts, as a component of the glutathione peroxidase enzymes. Soils and forages vary widely in Se concentration and a deficient diet can lead to sub-clinical or clinical deficiency in horses. Endurance horses are prone to oxidative stress during long periods of aerobic exercise and their performance could be affected by Se status. This study investigated the blood Se concentration in a group of endurance horses (n=56) residing and competing in California, a state containing several regions that tend to produce Se-deficient forages. The rate of Se deficiency in this group of horses was low, with only one horse being slightly below the reference range. Higher blood Se concentrations were not associated with improved performance in terms of ride time. There was no significant difference in Se concentration between horses that completed the ride and those that were disqualified, although blood Se concentrations were significantly higher in horses that received oral Se supplementation. An increase in blood Se concentration was observed following exercise and this warrants further study.

  10. Selenium Biofortification and Phytoremediation Phytotechnologies: A Review.

    PubMed

    Schiavon, Michela; Pilon-Smits, Elizabeth A H

    2017-01-01

    The element selenium (Se) is both essential and toxic for most life forms, with a narrow margin between deficiency and toxicity. Phytotechnologies using plants and their associated microbes can address both of these problems. To prevent Se toxicity due to excess environmental Se, plants may be used to phytoremediate Se from soil or water. To alleviate Se deficiency in humans or livestock, crops may be biofortified with Se. These two technologies may also be combined: Se-enriched plant material from phytoremediation could be used as green fertilizer or as fortified food. Plants may also be used to "mine" Se from seleniferous soils. The efficiency of Se phytoremediation and biofortification may be further optimized. Research in the past decades has provided a wealth of knowledge regarding the mechanisms by which plants take up, metabolize, accumulate, and volatilize Se and the role plant-associated microbes play in these processes. Furthermore, ecological studies have revealed important effects of plant Se on interactions with herbivores, detrivores, pollinators, neighboring vegetation, and the plant microbiome. All this knowledge can be exploited in phytotechnology programs to optimize plant Se accumulation, transformation, volatilization, and/or tolerance via plant breeding, genetic engineering, and tailored agronomic practices.

  11. 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.

  12. Selenium and cancer prevention: observations and complexity.

    PubMed

    Glattre, Eystein; Nygård, Jan F; Aaseth, Jan

    2012-06-01

    Early case-control and intervention studies suggested that selenium (Se) species might reduce the risk of cancer and in a pre-diagnostic case-control study from 1986 [1] we found that the higher the serum Se concentration, the lower was the odds ratio of thyroid cancer. Our data showed, however, that this observation occurred late in the pre-diagnostic period indicating that low serum Se was simply a consequence of thyroid cancer. In 1986 we therefore concluded that the only way to get an indisputable and lasting answer to the question was to carry out properly designed intervention studies. Great was our frustration therefore when we in 2003 [2] discovered that thyroid cancer morbidity is a fractal variable powered by such complexity that we may never find a definite and enduring answer: Even the best, randomised, controlled trial comparing the incidence rate among exposed and controls can only produce temporary answers due to the complexity background. The only possible way to come up with a lasting solution seems to be by means of reductionist experiments, but they have to be tested on man and then one is back to square one.

  13. 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.

  14. Effect of selenium deficiency on gene transcription

    SciTech Connect

    Christensen, M.J.; Burgener, K.W. )

    1991-03-11

    To investigate the general effects of dietary selenium (Se) deficiency on gene transcription, weanling male Sprague-Dawley rats were fed a basal Se-deficient Torula yeast-based diet or the same diet supplemented with 0.5 ppm Se as sodium selenite for 40 days. At that time three rats in each dietary group were sacrificed. Livers were excised and divided into two portions for isolation of nuclei and for assay of cytosolic Se-glutathione peroxidase (Se-GPX) activity. Se-GPX activity was 279 {plus minus} 4 (mean {plus minus} SEM) mUnits/mg protein in Se-adequate livers, and 10 {plus minus} 2 mUnits/mg protein in Se-deficient livers. One aliquot of nuclei from each dietary group was used in a run-on transcription assay, employing {alpha}-{sup 32}P-UTP to label nascent transcripts. Equal quantities of radioactivity from these nuclei were hybridized with cDNA probes bound to nitrocellulose. Message bound to each probe was quantitated by laser densitometry of autoradiographs, and by scintillation counting of dot blotted nitrocellulose. Transcription of most genes tested, including Se-GPX, was not significantly affected by dietary Se intake. However, the amount of hybridization to a murine oncogene probe (v-fos) was increased in Se deficiency.

  15. Study of selenium distribution in the protein fractions of the Brazil nut, Bertholletia excelsa.

    PubMed

    Chunhieng, Thavarith; Pétritis, Konstantinos; Elfakir, Claire; Brochier, José; Goli, Thierry; Montet, Didier

    2004-06-30

    The high selenium content of the Brazil nut, Bertholletia excelsa, makes this seed a healthy food qualified as an antiradical protector. The studied nut contained 126 ppm of selenium. Selenium was found to be distributed in the nut protein fractions. The water-extracted fraction, which represented 17.7% of the cake protein, was the richest in selenium with 153 ppm. Analysis by HPLC-MS showed that selenium was linked by a covalent bond to two amino acids to form selenomethionine and selenocystine. The selenomethionine represented a little less than 1% of the total amount of methionine.

  16. The biological selenium status of livestock in Britain as indicated by sheep erythrocyte glutathione peroxidase activity.

    PubMed

    Anderson, P H; Berrett, S; Patterson, D S

    1979-03-17

    The reliability of erythrocyte glutathione peroxidase activity as an indicator of selenium status in livestock is discussed. Based on this measurement, a survey is described of the biological selenium status of sheep on each of 329 farms in Britain. Results showed that 47 per cent of these farms were probably unable to provide grazing livestock with sufficient selenium to maintain blood levels greater than 0.075 microgram per ml. Increased selenium deficiency from the increasing use of home grown feeds as a major constituent of livestock rations may be causally related to the increase of white muscle disease and other selenium responsive diseases in Britain.

  17. Blood selenium status in normal Punjabi population of Pakistan.

    PubMed

    Alvi, Farrakh M; Chaudhri, Mohammad Anwar; Watling, John; Hasnain, Shahida

    2011-10-01

    Selenium concentrations in the blood of 112 (56 females and 56 males) normal subjects, from different regions of the Punjab (Pakistan), have been determined using the technique of inductively coupled plasma-mass spectrometry. The whole blood selenium concentrations were found to be 452 ± 12 ppb (parts per billion or nano-gram of Se per gram freeze-dried blood or 96 ± 3 μg/L ), with 470 ± 16 ppb (or 100 ± 4 μg/L) in female and 435 ± 16 ppb (or 92 ± 4 μg/L) in male population. Compared with other populations of the world [corrected] these levels are similar with the exception of the low-selenium-region of China. [corrected].

  18. Epigenetic effects of selenium and their implications for health.

    PubMed

    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.

  19. Dilated Cardiomyopathy Induced by Chronic Starvation and Selenium Deficiency

    PubMed Central

    2016-01-01

    Protein energy malnutrition (PEM) has been rarely documented as a cause of cardiovascular abnormalities, including dilated cardiomyopathy. Selenium is responsible for antioxidant defense mechanisms in cardiomyocytes, and its deficiency in the setting of PEM and disease related malnutrition (DRM) may lead to exacerbation of the dilated cardiomyopathy. We report a rare case of a fourteen-year-old boy who presented with symptoms of congestive heart failure due to DRM and PEM (secondary to chronic starvation) along with severe selenium deficiency. An initial echocardiogram showed severely depressed systolic function consistent with dilated cardiomyopathy. Aggressive nutritional support and replacement of selenium and congestive heart failure medications that included diuretics and ACE inhibitors with the addition of carvedilol led to normalization of the cardiac function within four weeks. He continues to have significant weight gain and is currently completely asymptomatic from a cardiovascular standpoint. PMID:27994905

  20. An Overview of Selenium Uptake, Metabolism, and Toxicity in Plants

    PubMed Central

    Gupta, Meetu; Gupta, Shikha

    2017-01-01

    Selenium (Se) is an essential micronutrient for humans and animals, but lead to toxicity when taken in excessive amounts. Plants are the main source of dietary Se, but essentiality of Se for plants is still controversial. However, Se at low doses protects the plants from variety of abiotic stresses such as cold, drought, desiccation, and metal stress. In animals, Se acts as an antioxidant and helps in reproduction, immune responses, thyroid hormone metabolism. Selenium is chemically similar to sulfur, hence taken up inside the plants via sulfur transporters present inside root plasma membrane, metabolized via sulfur assimilatory pathway, and volatilized into atmosphere. Selenium induced oxidative stress, distorted protein structure and function, are the main causes of Se toxicity in plants at high doses. Plants can play vital role in overcoming Se deficiency and Se toxicity in different regions of the world, hence, detailed mechanism of Se metabolism inside the plants is necessary for designing effective Se phytoremediation and biofortification strategies. PMID:28123395

  1. 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.

  2. Investigation of biotransformation of selenium in plants using spectrometric methods

    NASA Astrophysics Data System (ADS)

    Ruszczyńska, Anna; Konopka, Anna; Kurek, Eliza; Torres Elguera, Julio Cesar; Bulska, Ewa

    2017-04-01

    The aim of this research was to study the processes of biotransformation of selenium in plants such as garlic, radish sprouts and sunflower sprouts via identification of selenium-containing compounds as metabolites of inorganic selenium using mass spectrometry. Speciation analysis of selenium in extracts from plant samples was performed with the use of hyphenated high performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS) method. Matching the retention times of sample compounds with standards allowed identification of Se-methyl-selenocysteine, selenomethionine, γ-glutamyl-Se-methylselenocysteine and inorganic SeO32 -. However, registered chromatograms included additional 82Se signals which couldn't be identified due to the lack of standards. Qualitative analysis of unknown compounds was achieved using high-resolution mass spectrometer equipped with mass analyzer Orbitrap coupled to high performance liquid chromatography. Since selenium has six stable isotopes of different abundance in nature, mass spectra of have a very characteristic isotopic pattern. In order to elucidate the structure of unknown Se compounds, selected ions were subjected to the fragmentation. Following selenocompounds were identified an inorganic selenium metabolites in garlic, sunflower sprouts and/or radish sprouts: selenohomolanthionine, Se-methyl-selenocysteine, selenomethionine, selenomethionine oxide, deaminohydroxy-selenohomolanthionine, N-acetylcysteine-selenomethionine, γ-glutamyl-Se-methyl-selenocysteine, methylseleno-Se-pentose-hexose, Se-methyl-selenoglutathione, 2,3-dihydroxy-propionyl-selenocysteine-cysteine, methyltio-selenoglutathione, 2,3-dihydroxypropionyl-selenolanthionine and two Se-containing compounds with proposed molecular formula C10H18N2O6Se and C10H13N5O3Se. Moreover, the structure was proposed for one selenocompound found in sunflower sprouts which has not been reported so far.

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

    USGS Publications Warehouse

    Clark, D.R.

    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.

  4. 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.

  5. Reduction of selenite to elemental selenium nanoparticles by activated sludge.

    PubMed

    Jain, Rohan; Matassa, Silvio; Singh, Satyendra; van Hullebusch, Eric D; Esposito, Giovanni; Lens, Piet N L

    2016-01-01

    Total selenium removal by the activated sludge process, where selenite is reduced to colloidal elemental selenium nanoparticles (BioSeNPs) that remain entrapped in the activated sludge flocs, was studied. Total selenium removal efficiencies with glucose as electron donor (2.0 g chemical oxygen demand (COD) L(-1)) at neutral pH and 30 °C gave 2.9 and 6.8 times higher removal efficiencies as compared to the electron donors lactate and acetate, respectively. Total selenium removal efficiencies of 79 (±3) and 86 (±1) % were achieved in shake flasks and fed batch reactors, respectively, at dissolved oxygen (DO) concentrations above 4.0 mg L(-1) and 30 °C when fed with 172 mg L(-1) (1 mM) Na2SeO3 and 2.0 g L(-1) COD of glucose. Continuously operated reactors operating at neutral pH, 30 °C and a DO >3 mg L(-1) removed 33.98 and 36.65 mg of total selenium per gram of total suspended solids (TSS) at TSS concentrations of 1.3 and 3.0 g L(-1), respectively. However, selenite toxicity to the activated sludge led to failure of a continuously operating activated sludge reactor at the applied loading rates. This suggests that a higher hydraulic retention time (HRT) or different reactor configurations need to be applied for selenium-removing activated sludge processes. Graphical Abstract Scheme representing the possible mechanisms of selenite reduction at high and low DO levels in the activated sludge process.

  6. 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.

  7. 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.

  8. Selenium toxicity to aquatic life: An argument for sediment-based water quality criteria

    SciTech Connect

    Canton, S.P.; Van Derveer, W.D.

    1997-06-01

    A number of streams in Colorado were found to contain waterborne selenium concentrations that consistently exceeded the current US EPA chronic criterion of 5 {micro}g/L and often exceeded the acute criterion of 210 {micro}g/L. Despite these elevated concentrations, no biological impact was observed. These findings led to a review of selenium exposure pathways in freshwater. The literature strongly indicates that chronic selenium toxicity can result from accumulation of selenium in the sediment, movement into the food chain, and resulting dietary uptake. Chronic toxicity does not appear to be strictly a result of waterborne selenium concentrations. In fact, dissolved selenium concentrations are a poor predictor of potential chronic toxicity to freshwater organisms, when evaluated with Hill`s criteria for causal association. To develop a more reliable chronic waterborne criterion, a sediment-based method is needed to describe accurately potential chronic toxicity of selenium on a site-specific basis.

  9. The importance of selenium in the prenatal and postnatal development of calves and lambs.

    PubMed

    Bostedt, H; Schramel, P

    1990-02-01

    Selenium deficiency is responsible for Zenker type muscle degeneration in calves, lambs, and foals in the prenatal and postnatal stages of development. Investigations have shown that the selenium GSH Px, and vitamin E content of the maternal and fetal parts of the placenta in cattle are different. Similarly, low concentrations of selenium are present in milk from cows and sheep. In addition to an inadequate supply of selenium and vitamin E as a contributory cause of fetal nutritive muscular dystrophy (FNMD), it is assumed that a placental transport block and/or impaired selenium metabolism in the placenta are also responsible. Postnatal nutritive muscular dystrophy, however, is attributed to either acute selenium and vitamin E deficiency in basic feed or impaired plant absorption of selenium as a result of antagonistic elements, such as sulphur.

  10. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Pine River Project area, Southern Ute Indian Reservation, southwestern Colorado and northwestern New Mexico, 1988-89

    USGS Publications Warehouse

    Butler, D.L.; Krueger, R.P.; Osmundson, B.C.; Thompson, A.L.; Formea, J.J.; Wickman, D.W.

    1993-01-01

    During 1988-89, water, bottom sediment, biota, soil, and plants were sampled for a reconnaissance investigation of the Pine River Project area in southwestern Colorado. Irrigation drainage does not seem to be a major source of dissolved solids in streams. Concentrations of manganese, mercury, and selenium exceeded drinking-water regulations in some streams. The maximum selenium concentration in a stream sample was 94 microg/L in Rock Creek. Irrigation drainage and natural groundwater are sources of some trace elements to streams. Water from a well in a nonirrigated area had 4,800 microg/L of selenium. Selenium concentrations in soil on the Oxford Tract were greater in areas previously or presently irrigated than in areas never irrigated. Some forage plants on the Oxford Tract had large selenium concentrations, including 180 mg/km in alfalfa. Most fish samples had selenium concentrations greater than the National Contaminant Biomonitoring Program 85th percentile. Selenium concentrations in aquatic plants, aquatic inverte- brates, and small mammals may be of concern to fish and wildlife because of possible food-chain bioconcentration. Selenium concentrations in bird samples indicate selenium contamination of biota on the Oxford Tract. Mallard breasts had selenium concentrations exceeding a guideline for human consumption. The maximum selenium concentration in biota was 50 microg/g dry weight in a bird liver from the Oxford Tract. In some fish samples, arsenic, cadmium, copper, and zinc exceeded background concentrations, but concentrations were not toxic. Mercury concentrations in 16 fish samples exceeded the background concentration. Ten mercury concentrations in fish exceeded a guideline for mercury in food for consumption by pregnant women.

  11. Fourth-grade children's dietary recall accuracy for energy intake at school meals differs by social desirability and body mass index percentile in a study concerning retention interval.

    PubMed

    Guinn, Caroline H; Baxter, Suzanne D; Royer, Julie A; Hardin, James W; Mackelprang, Alyssa J; Smith, Albert F

    2010-05-01

    Data from a study concerning retention interval and school-meal observation on children's dietary recalls were used to investigate relationships of social desirability score (SDS) and body mass index percentile (BMI%) to recall accuracy for energy for observed (n = 327) children, and to reported energy for observed and unobserved (n = 152) children. Report rates (reported/observed) correlated negatively with SDS and BMI%. Correspondence rates (correctly reported/observed) correlated negatively with SDS. Inflation ratios (overreported/observed) correlated negatively with BMI%. The relationship between reported energy and each of SDS and BMI% did not depend on observation status. Studies utilizing children's dietary recalls should assess SDS and BMI%.

  12. Selenium metabolism in cancer cells: the combined application of XAS and XFM techniques to the problem of selenium speciation in biological systems.

    PubMed

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

    2013-05-21

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

  13. Selenium species determination in selenium-enriched pumpkin (Cucurbita pepo L.) seeds by HPLC-UV-HG-AFS.

    PubMed

    Smrkolj, Polona; Stibilj, Vekoslava; Kreft, Ivan; Kapolna, Emese

    2005-12-01

    Pumpkins were treated by spraying the leaves in the flowering period with a water solution containing 1.5 mg Se per liter in the form of Na2SeO4. The average total selenium content of seeds was found to be 0.19 microg g(-1) in nontreated pumpkins and 1.1 microg g(-1) in exposed ones. For speciation analysis, enzymatic hydrolysis with different amounts of Protease XIV was carried out. Under optimal conditions of enzymatic hydrolysis, 90% of the total selenium was found in soluble forms. Separation of species was performed using HPLC on anion and cation exchange columns and for detection UVHG-AFS was applied. In enzymatic hydrolysis extracts, the main fraction of selenium was bound as selenomethionine (SeMet), representing on average of 81 +/- 8% of the total Se content in the sample.

  14. 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.

  15. 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

  16. Sorption and diffusion of selenium oxyanions in granitic rock

    NASA Astrophysics Data System (ADS)

    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

  17. 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

  18. Biochemical Comparison of Commercial Selenium Yeast Preparations.

    PubMed

    Fagan, Sheena; Owens, Rebecca; Ward, Patrick; Connolly, Cathal; Doyle, Sean; Murphy, Richard

    2015-08-01

    The trace mineral selenium (Se) is an essential element for human and animal nutrition. The addition of Se to the diet through dietary supplements or fortified food/feed is increasingly common owing to the often sub-optimal content of standard diets of many countries. Se supplements commercially available include the inorganic mineral salts such as sodium selenite or selenate, and organic forms such as Se-enriched yeast. Today, Se yeast is produced by several manufacturers and has become the most widely used source of Se for human supplementation and is also widely employed in animal nutrition where approval in all species has been granted by regulatory bodies such as the European Food Safety Authority (EFSA). Characterisation and comparison of Se-enriched yeast products has traditionally been made by quantifying total selenomethionine (SeMet) content. A disadvantage of this approach, however, is that it does not consider the effects of Se deposition on subsequent digestive availability. In this study, an assessment was made of the water-soluble extracts of commercially available Se-enriched yeast samples for free, peptide-bound and total water-soluble SeMet. Using LC-MS/MS, a total of 62 Se-containing proteins were identified across four Se yeast products, displaying quantitative/qualitative changes in abundance relative to the certified reference material, SELM-1 (P value <0.05; fold change ≥2). Overall, the study indicates that significant differences exist between Se yeast products in terms of SeMet content, Se-containing protein abundance and associated metabolic pathways.

  19. Clinical assessment of selenium status of livestock.

    PubMed

    Stowe, H D; Herdt, T H

    1992-12-01

    Assessment of the selenium status of livestock is an important aspect of production medicine, but variations in reported values between laboratories and between methods may be > 30%. Reliable interpretations require considerable experience with an assay and an extensive database from field and research case samples of a variety of species. The Michigan State University Animal Health Diagnostic Laboratory (MSU-ADHL) has offered Se analyses by acid-digestion and fluorometric detection since 1982. This laboratory expects serum Se values (nanograms per milliliter) of livestock to increase gradually with age from starting ranges for neonates of 50 to 80 for calves and sheep and 70 to 90 for foals and pigs. Expected or "normal" values for the adults are in the ranges of 70 to 100 for cattle, 120 to 150 for sheep, 130 to 160 for horses, and 180 to 220 for swine. Normal liver Se concentrations are considered to range between 1.2 and 2.0 micrograms/g on a dry weight basis, regardless of the species or age. Based on samples submitted to MSU-AHDL between September 1990 and August 1991, contemporary feeding practices in the Michigan area resulted in mean serum Se values (nanograms per milliliter) of 75 +/- 19 for adult Holsteins, 170 +/- 27 for adult swine (mixed breeds), and 137 +/- 30 for adult race horses. Within that period of time, two field cases of Se toxicity were diagnosed. One involved feeder pigs with a recorded high serum Se value of 1,525 ng/mL due to a commercial premix manufacturing error.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Determination of the selenium requirement in kittens.

    PubMed

    Wedekind, K J; Howard, K A; Backus, R C; Yu, S; Morris, J G; Rogers, Q R

    2003-10-01

    The purpose of this study was to determine the selenium (Se) requirement in kittens. Thirty-six specific-pathogen-free kittens (9.8 weeks old) were utilized in a randomized complete block design to determine the Se requirement in cats with gender and weight used as blocking criteria. Kittens were fed a low Se (0.02 mg/kg Se) torula yeast-based diet for 5 weeks (pre-test) after which an amino acid-based diet (0.027 mg Se/kg diet) was fed for 8 weeks (experimental period). Six levels of Se (0, 0.05, 0.075, 0.10, 0.20 and 0.30 mg Se/kg diet) as Na2SeO3 were added to the diet and were used to construct a response curve. Response variables included Se concentrations and Se-dependent glutathione peroxidase activities (GSHpx) in plasma and red blood cells (RBC) as well as plasma total T3 (TT3) and total T4 (TT4). No significant changes in food intake, weight gain or clinical signs of Se deficiency were noted. Estimates of the kitten's Se requirement (i.e. breakpoints) were determined for RBC and plasma GSHpx (0.12 and 0.15 mg Se/kg diet, respectively), but no definitive breakpoint was determined for plasma Se. Plasma TT3 increased linearly, whereas plasma TT4 and the ratio of TT4 : TT3 decreased in a quadratic fashion to dietary Se concentration. The requirement estimate determined in this study (0.15 mg Se/kg) for kittens is in close agreement with other species. As pet foods for cats contain a high proportion of animal protein with a Se bioavailability of 30%, it is recommended that commercial diets for cats contain 0.5 mg Se/kg DM.

  1. Selenium enrichment of broccoli: interactions between selenium and secondary plant compounds.

    PubMed

    Finley, John W; Sigrid-Keck, Anna; Robbins, Rebecca J; Hintze, Korry J

    2005-05-01

    Multiple components of broccoli, such as sulforaphane (Sf) and phenolic acids, may inhibit cancer. Additionally, broccoli can accumulate selenium (Se), and Se has been demonstrated to reduce the risk of cancer. Studies were conducted to determine whether enhancement of broccoli with Se would produce a plant with superior health benefits. Although increasing the concentration of Se in broccoli from <1.0 to >800 microg/g resulted in inhibition of colon cancer in rats, it also decreased the Sf content by >80% and inhibited production of most phenolic acids. The inclusion of Se-enriched broccoli in the diet of rats induced the activity of the selenoprotein thioredoxin reductase beyond the maximum activity induced by Se alone. These results emphasize the complex interactions of bioactive chemicals in a food; attempts to maximize one component may affect accumulation of another, and consumption of high amounts of multiple bioactive compounds may result in unexpected metabolic interactions within the body.

  2. Soil-type influences human selenium status and underlies widespread selenium deficiency risks in Malawi.

    PubMed

    Hurst, Rachel; Siyame, Edwin W P; Young, Scott D; Chilimba, Allan D C; Joy, Edward J M; Black, Colin R; Ander, E Louise; Watts, Michael J; Chilima, Benson; Gondwe, Jellita; Kang'ombe, Dalitso; Stein, Alexander J; Fairweather-Tait, Susan J; Gibson, Rosalind S; Kalimbira, Alexander A; Broadley, Martin R

    2013-01-01

    Selenium (Se) is an essential human micronutrient with critical roles in immune functioning and antioxidant defence. Estimates of dietary Se intakes and status are scarce for Africa although crop surveys indicate deficiency is probably widespread in Malawi. Here we show that Se deficiency is likely endemic in Malawi based on the Se status of adults consuming food from contrasting soil types. These data are consistent with food balance sheets and composition tables revealing that >80% of the Malawi population is at risk of dietary Se inadequacy. Risk of dietary Se inadequacy is >60% in seven other countries in Southern Africa, and 22% across Africa as a whole. Given that most Malawi soils cannot supply sufficient Se to crops for adequate human nutrition, the cost and benefits of interventions to alleviate Se deficiency should be determined; for example, Se-enriched nitrogen fertilisers could be adopted as in Finland.

  3. Soil-type influences human selenium status and underlies widespread selenium deficiency risks in Malawi

    PubMed Central

    Hurst, Rachel; Siyame, Edwin W. P.; Young, Scott D.; Chilimba, Allan D. C.; Joy, Edward J. M.; Black, Colin R.; Ander, E. Louise; Watts, Michael J.; Chilima, Benson; Gondwe, Jellita; Kang'ombe, Dalitso; Stein, Alexander J.; Fairweather-Tait, Susan J.; Gibson, Rosalind S.; Kalimbira, Alexander A.; Broadley, Martin R.

    2013-01-01

    Selenium (Se) is an essential human micronutrient with critical roles in immune functioning and antioxidant defence. Estimates of dietary Se intakes and status are scarce for Africa although crop surveys indicate deficiency is probably widespread in Malawi. Here we show that Se deficiency is likely endemic in Malawi based on the Se status of adults consuming food from contrasting soil types. These data are consistent with food balance sheets and composition tables revealing that >80% of the Malawi population is at risk of dietary Se inadequacy. Risk of dietary Se inadequacy is >60% in seven other countries in Southern Africa, and 22% across Africa as a whole. Given that most Malawi soils cannot supply sufficient Se to crops for adequate human nutrition, the cost and benefits of interventions to alleviate Se deficiency should be determined; for example, Se-enriched nitrogen fertilisers could be adopted as in Finland. PMID:23478344

  4. Body fat percentile curves for Korean children and adolescents: a data from the Korea National Health and Nutrition Examination Survey 2009-2010.

    PubMed

    Kim, Kirang; Yun, Sung Ha; Jang, Myoung Jin; Oh, Kyung Won

    2013-03-01

    A valid assessment of obesity in children and adolescents is important due to significant change in body composition during growth. This study aimed to develop percentile curves of body fat and fat free mass using the Lambda, Mu, and Sigma method, and to examine the relationship among body mass index (BMI), fat mass and fat free mass in Korean children and adolescents, using the Korea National Health and Nutrition Examination Survey (KNHANES) 2009-2010. The study subjects were 834 for boys and 745 for girls aged between 10 and 18 yr. Fat mass and fat free mass were measured by dual-energy x-ray absorptiometry. The patterns of development in body fat percentage, fat mass and fat free mass differed for boys and girls, showing a decreased fat mass with an increased fat free mass in boys but gradual increases with age in girls. The considerable proportion of boys and girls with relatively normal fat mass appeared to be misclassified to be at risk of overweight based on the BMI criteria. Therefore, the information on the percentiles of body fat and fat free mass with their patterns would be helpful to complement assessment of overweight and obesity based on BMI for Korean children and adolescents.

  5. Subacute toxicity of nano-selenium compared to other selenium species in mice.

    PubMed

    Benko, Ilona; Nagy, Gabor; Tanczos, Bence; Ungvari, Eva; Sztrik, Attila; Eszenyi, Peter; Prokisch, Jozsef; Banfalvi, Gaspar

    2012-12-01

    Sixteen groups of mice were fed diets containing different selenium species to compare their toxicity. Inorganic sodium selenate and sodium hydroselenite, elementary nanoSe, organic Sel-Plex, and Lacto-MicroSelenium were administered for 14 d at concentrations of 0.5, 5, and 50 ppm Se, equivalent to 0.5, 5, and 50 mg Se/kg food, corresponding to an estimated 4, 40, and 400 µg/kg body weight/d Se uptake, respectively. At the end of the treatment, body, liver, spleen, kidney, heart, and brain weights were measured, mice were subjected to necropsy, and histological examinations were performed on the liver. At lower Se doses (0.5 and 5 ppm) a moderate reduction was observed in the number of bone marrow and white blood cells and in granulocyte-macrophage colony-forming units (GM-CFUs) relative to the untreated control group of mice. A comparison of lowest toxic doses of sodium selenite in mice (0.5 ppm) and mallard (10 ppm) indicates that birds are more resistant to Se than rodents. In mice, a small but measurable weight loss was observed after 5 ppm selenate and LactoMicroSe treatment. The most significant changes took place after 50-ppm administration in body and spleen weight, hematology, and liver histology. Toxicity was more pronounced when inorganic Se was applied than after subacute application of Sel-Plex, nanoSe, or LactoMicroSe. To summarize the effects, the authors' 14-d murine subacute toxicity study showed that the toxicity of Se species decreased in the following order: selenate > selenite > nanoSe > Sel-Plex > LactoMicroSe.

  6. Choice feeding of selenium-deficient laying hens affects diet selection, selenium intake and body weight.

    PubMed

    Zuberbuehler, Christine A; Messikommer, Ruth E; Wenk, Caspar

    2002-11-01

    Inadequate selenium (Se) supply often in combination with low vitamin E status causes deficiency symptoms in many species. It is likely that a vague discomfort or sickness is perceived before clear deficiency signs become apparent. We investigated whether Se-deficient hens reduce their Se deficit by selecting a diet containing more selenium when offered two diets with different Se concentrations. A Low-Se diet (0.07 mg Se/kg) was supplemented with Se-enriched yeast (Sel-Plex 50) to produce Medium-Se (0.20 mg Se/kg) and High-Se (1.50 mg Se/kg) diets. Each of two consecutive study parts (I and II) with the same hens and treatments began with a 6-wk baseline period (Medium-Se diet), subsequently followed a 9-wk depletion period (Low-Se diet or Medium-Se diet), then a 6-wk choice feeding period in which two diets with different Se concentrations (Low-Se and Medium-Se, Medium-Se and High-Se, or Low-Se and High-Se) were offered. A control group received the Medium-Se diet throughout the study. Daily Se intake, calculated from daily feed intake, followed similar patterns in both parts of the study, but Se-deficient hens preferred (P < 0.05) the High-Se diet to the Low-Se diet during the first 3 wk of choice feeding only in part I. We conclude that young Se-deficient laying hens reduce their Se deficit if they have a choice between a Low-Se and a High-Se diet by preferentially selecting the High-Se diet, possibly based on learned place preference and/or learned taste aversion to the Low-Se diet, presumably in response to discomfort due to Se-deficiency.

  7. Effect of dietary sulfur and selenium concentrations on selenium balance of lactating Holstein cows.

    PubMed

    Ivancic, J; Weiss, W P

    2001-01-01

    The effects of dietary sulfate and selenium concentrations on selenium balance in dairy cows were investigated. Midlactation Holstein cows (n = 30) were fed diets containing either 0.1 or 0.3 mg of supplemental Se (from sodium selenate)/kg of dry matter and 0, 0.2, or 0.4% added S from a mix of calcium and magnesium sulfate in a factorial arrangement. The experiment lasted 112 d. Dry matter intake was linearly reduced with increasing S, but the effect was greater when 0.3 mg/kg of Se was fed (significant interaction). Treatment effects for yields of milk, milk fat, and milk protein were similar to those for dry matter intake. Increased dietary S linearly reduced plasma Se concentrations. Increasing dietary S linearly reduced apparent (42.7, 33.1, and 30.1%) and estimated true (50.5, 46.0, and 42.3%) Se digestibility. Excretion of Se via feces (1.6 vs. 2.8 mg/d) and urine (0.5 vs. 1.3 mg/d) was higher and output in milk (0.4 vs. 0.3 mg/d) was lower for cows fed 0.3 mg/kg of Se compared with 0.1 mg/kg, but no Se effect was found for estimated true Se digestibility. Dietary S from sulfate reduced Se balance especially when cows were fed diets with less than 0.3 mg of Se/kg of diet dry matter.

  8. 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.

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

    PubMed

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

    2012-08-01

    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 interspecific 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.

  10. [Selenium supplementation trials for cancer prevention and the subsequent risk of type 2 diabetes mellitus: selenium and vitamin E cancer prevention trial and after].

    PubMed

    Koyama, Hiroshi; Mutakin; Abdulah, Rizky; Yamazaki, Chiho; Kameo, Satomi

    2013-01-01

    The essential trace element selenium has long been considered to exhibit cancer-preventive, antidiabetic and insulin-mimetic properties. However, recent epidemiological studies have indicated that supranutritional selenium intake and high plasma selenium levels are not necessarily preventive against cancer, and are possible risk factors for developing type 2 diabetes mellitus. The results of the SELECT, Selenium and Vitamin E Cancer Prevention Trial, in which it is hypothesized that the supplementations with selenium and/or vitamin E decrease the prostate cancer incidence among healthy men in the U.S., showed that the supplementation did not prevent the development of prostate cancer and that the incidence of newly diagnosed type 2 diabetes mellitus increased among the selenium-supplemented participants. The Nutritional Prevention of Cancer (NPC) trial showed a decreased risk of prostate cancer among participants taking 200 μg of selenium daily for 7.7 years. However, the results of the NPC trial also showed an increased risk of type 2 diabetes mellitus in the participants with plasma selenium levels in the top tertile at the start of the study. Recently, the association of serum selenium with adipocytokines, such as TNF-α, VCAM-1, leptin, FABP-4, and MCP-1, has been observed. Selenoprotein P has been reported to associated with adiponectin, which suggests new roles of selenoprotein P in cellular energy metabolism, possibly leading to the increased risk of type 2 diabetes mellitus and also the development of cancer. Further studies are required to elucidate the relationship between selenium and adipocytokines and the role of selenoprotein P in the development of type 2 diabetes mellitus and cancer at high levels of selenium.

  11. 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

  12. 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

  13. 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.

  14. Xanthotrichia (yellow hair) due to selenium sulfide and dihydroxyacetone.

    PubMed

    Prevost, Noel; English, Joseph C

    2008-07-01

    Hair shaft discoloration has been documented to be caused by disease states, medications, and exogenous chemicals. After researching the literature, xanthotrichia or yellow hair has been determined to be caused predominately by exogenous chemicals. Two cases of new chemicals causing yellow hair shaft discoloration are reported. The chemicals include selenium sulfide 2.5% shampoo and dihydroxyacetone.

  15. Biological effects of a nano red elemental selenium.

    PubMed

    Zhang, J S; Gao, X Y; Zhang, L D; Bao, Y P

    2001-01-01

    A novel selenium form, nano red elemental selenium (Nano-Se) was prepared by adding bovine serum albumin to the redox system of selenite and glutathione. Nano-Se has a 7-fold lower acute toxicity than sodium selenite in mice (LD(50) 113 and 15 mg Se/kg body weight respectively). In Se-deficient rat, both Nano-Se and selenite can increase tissue selenium and GPx activity. The biological activities of Nano-Se and selenite were compared in terms of cell proliferation, enzyme induction and protection against free racial-mediated damage in human hepatoma HepG2 cells. Nano-Se and selenite are similarly cell growth inhibited and stimulated synthesis of glutathione peroxidase (GPx), phospholipid hydroperoxide glutathione peroxidase (PHGPx) and thioredoxin reductase (TR). When HepG2 cells were co-treated with selenium and glutathione, Nano-Se showed less pro-oxidative effects than selenite, as measured by cell growth. These results demonstrate that Nano-Se has a similar bioavailability in the rat and antioxidant effects on cells.

  16. 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.

  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. 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.

  19. 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...

  20. Selenium status of children living in seleniferous areas of Venezuela.

    PubMed

    Brätter, P; Negretti de Brätter, V E; Jaffé, W G; Mendez Castellano, H

    1991-12-01

    Selenium was measured in red blood cells, serum and hair of children and in breast milk of mothers in seleniferous areas of Venezuela by means of neutron activation analysis. Signs of selenosis were observed only in a few cases. Reduction in the rate of growth is discussed with respect to unequal local nutritional conditions during the growth period.

  1. Water-sediment controversy in setting environmental standards for selenium

    USGS Publications Warehouse

    Hamilton, Steven J.; Lemly, A. Dennis

    1999-01-01

    A substantial amount of laboratory and field research on selenium effects to biota has been accomplished since the national water quality criterion was published for selenium in 1987. Many articles have documented adverse effects on biota at concentrations below the current chronic criterion of 5 μg/L. This commentary will present information to support a national water quality criterion for selenium of 2 μg/L, based on a wide array of support from federal, state, university, and international sources. Recently, two articles have argued for a sediment-based criterion and presented a model for deriving site-specific criteria. In one example, they calculate a criterion of 31 μg/L for a stream with a low sediment selenium toxicity threshold and low site-specific sediment total organic carbon content, which is substantially higher than the national criterion of 5 μg/L. Their basic premise for proposing a sediment-based method has been critically reviewed and problems in their approach are discussed.

  2. 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...

  3. 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...

  4. 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 ...

  5. Microbial transformation of elements: the case of arsenic and selenium

    USGS Publications Warehouse

    Stolz, J.; Basu, P.; Oremland, R.

    2002-01-01

    Microbial activity is responsible for the transformation of at least one third of the elements in the periodic table. These transformations are the result of assimilatory, dissimilatory, or detoxification processes and form the cornerstones of many biogeochemical cycles. Arsenic and selenium are two elements whose roles in microbial ecology have only recently been recognized. Known as "essential toxins", they are required in trace amounts for growth and metabolism but are toxic at elevated concentrations. Arsenic is used as an osmolite in some marine organisms while selenium is required as selenocysteine (i.e. the twenty-first amino acid) or as a ligand to metal in some enzymes (e.g. FeNiSe hydrogenase). Arsenic resistance involves a small-molecular-weight arsenate reductase (ArsC). The use of arsenic and selenium oxyanions for energy is widespread in prokaryotes with representative organisms from the Crenarchaeota, thermophilic bacteria, low and high G+C gram-positive bacteria, and Proteobacteria. Recent studies have shown that both elements are actively cycled and play a significant role in carbon mineralization in certain environments. The occurrence of multiple mechanisms involving different enzymes for arsenic and selenium transformation indicates several different evolutionary pathways (e.g. convergence and lateral gene transfer) and underscores the environmental significance and selective impact in microbial evolution of these two elements.

  6. [SELENIUM EFFICIENCY IN PROPHYLAXIS AND COMPLEX TREATMENT OF DIFFUSE GOITER].

    PubMed

    Osadtsiv, O I; Kravchenko, V I; Andrusyshyna, I M

    2014-01-01

    Efficiency of the combined prophylaxis and treatment of a diffuse goiter by preparations of sele- nium and iodine at 54 patients--men at the age of 41-50 years with the diagnosis of a diffuse goiter of 1st and 2nd degree was investigated. The diagnosis of a diffuse goiter was based on palpatory and ultrasonic research of the thyroid gland, which volume was compared with a body surface area. All surveyed have been divided into three groups. Patients of the first group accepted preparations of selenium and the iodine throughout three months, the second group--iodine preparations, in control group only dynamic supervision was spent. Thyroid gland volume at men who constantly used iodated salt and had no palpatory signs of a goiter was also measured for control. In the group which members accepted selenium and iodine preparations, at 11,8 % of patients was noted reduction of thyroid volume to normal and was revealed more expressed reduction of thyroid volume (for 2.15 sm3/M2 ± 0.07 sm3/M2), than at monotherapy by iodine preparations (for 0.92 sm3/M2 ± 0.17 sm3/M2). The conclusion was made that it is possible to recommend selenium preparations in a dose of 100 mkg a day together with preparations of iodine for prophylaxis and treatment of a diffuse goiter in conditions of the combined insufficiency in consumption of selenium and light deficiency of iodine.

  7. 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...

  8. 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...

  9. 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...

  10. Microbial transformation of elements: the case of arsenic and selenium.

    PubMed

    Stolz, J F; Basu, P; Oremland, R S

    2002-12-01

    Microbial activity is responsible for the transformation of at least one third of the elements in the periodic table. These transformations are the result of assimilatory, dissimilatory, or detoxification processes and form the cornerstones of many biogeochemical cycles. Arsenic and selenium are two elements whose roles in microbial ecology have only recently been recognized. Known as "essential toxins", they are required in trace amounts for growth and metabolism but are toxic at elevated concentrations. Arsenic is used as an osmolite in some marine organisms while selenium is required as selenocysteine (i.e. the twenty-first amino acid) or as a ligand to metal in some enzymes (e.g. FeNiSe hydrogenase). Arsenic resistance involves a small-molecular-weight arsenate reductase (ArsC). The use of arsenic and selenium oxyanions for energy is widespread in prokaryotes with representative organisms from the Crenarchaeota, thermophilic bacteria, low and high G+C gram-positive bacteria, and Proteobacteria. Recent studies have shown that both elements are actively cycled and play a significant role in carbon mineralization in certain environments. The occurrence of multiple mechanisms involving different enzymes for arsenic and selenium transformation indicates several different evolutionary pathways (e.g. convergence and lateral gene transfer) and underscores the environmental significance and selective impact in microbial evolution of these two elements.

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

    PubMed

    Diaz, Ximena; Johnson, William P; Naftz, David L

    2009-03-15

    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.

  12. 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...

  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. Mechanism of Selenium Chemoprevention and Therapy in Prostate Cancer

    DTIC Science & Technology

    2006-11-01

    NUMBER E-Mail: allen.gao@roswellpark.org 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION...Epidemiol Biomarkers Prev 2000;9:883–7. 7. Yoshizawa K, Willett WC, Morris SJ, et al. Study of prediagnostic selenium level in toenails and the risk of

  15. 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

  16. 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...

  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. 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....

  19. 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...

  20. Reducing bone cancer cell functions using selenium nanocomposites.

    PubMed

    Stolzoff, Michelle; Webster, Thomas J

    2016-02-01

    Cancer recurrence at the site of tumor resection remains a major threat to patient survival despite modern cancer therapeutic advances. Osteosarcoma, in particular, is a very aggressive primary bone cancer that commonly recurs after surgical resection, radiation, and chemotherapeutic treatment. The objective of the present in vitro study was to develop a material that could decrease bone cancer cell recurrence while promoting healthy bone cell functions. Selenium is a natural part of our diet which has shown promise for reducing cancer cell functions, inhibiting bacteria, and promoting healthy cells functions, yet, it has not been widely explored for osteosarcoma applications. For this purpose, due to their increased surface area, selenium nanoparticles (SeNP) were precipitated on a very common orthopedic tissue engineering material, poly-l-lactic acid (or PLLA). Selenium-coated PLLA materials were shown to selectively decrease long-term osteosarcoma cell density while promoting healthy, noncancerous, osteoblast functions (for example, up to two times more alkaline phosphatase activity on selenium coated compared to osteoblasts grown on typical tissue culture plates), suggesting they should be further studied for replacing tumorous bone tissue with healthy bone tissue. Importantly, results of this study were achieved without the use of chemotherapeutics or pharmaceutical agents, which have negative side effects.

  1. 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.

  2. Molecular structure of vapor-deposited amorphous selenium

    NASA Astrophysics Data System (ADS)

    Goldan, A. H.; Li, C.; Pennycook, S. J.; Schneider, J.; Blom, A.; Zhao, W.

    2016-10-01

    The structure of amorphous selenium is clouded with much uncertainty and contradictory results regarding the dominance of polymeric chains versus monomer rings. The analysis of the diffraction radial distribution functions are inconclusive because of the similarities between the crystalline allotropes of selenium in terms of the coordination number, bond length, bond angle, and dihedral angle. Here, we took a much different approach and probed the molecular symmetry of the thermodynamically unstable amorphous state via analysis of structural phase transformations. We verified the structure of the converted metastable and stable crystalline structures using scanning transmission electron microscopy. In addition, given that no experimental technique can tell us the exact three-dimensional atomic arrangements in glassy semiconductors, we performed molecular-dynamic simulations using a well-established empirical three-body interatomic potential. We developed a true vapor-deposited process for the deposition of selenium molecules onto a substrate using empirical molecular vapor compositions and densities. We prepared both vapor-deposited and melt-quenched samples and showed that the simulated radial distribution functions match very well to experiment. The combination of our experimental and molecular-dynamic analyses shows that the structures of vapor- and melt-quenched glassy/amorphous selenium are quite different, based primarily on rings and chains, respectively, reflecting the predominant structure of the parent phase in its thermodynamic equilibrium.

  3. 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 ...

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

    NASA Astrophysics Data System (ADS)

    Kausch, M. F.; Pallud, C. E.

    2013-03-01

    Soil aggregates are mm- to cm-sized microporous structures separated by macropores. Whereas fast advective transport prevails in macropores, advection is inhibited by the low permeability of intra-aggregate micropores. This can lead to mass transfer limitations and the formation of aggregate scale concentration gradients affecting the distribution and transport of redox sensitive elements. Selenium (Se) mobilized through irrigation of seleniferous soils has emerged as a major aquatic contaminant. In the absence of oxygen, the bioavailable oxyanions selenate, Se(VI), and selenite, Se(IV), can be microbially reduced to solid, elemental Se, Se(0), and anoxic microzones within soil aggregates are thought to promote this process in otherwise well-aerated soils. To evaluate the impact of soil aggregate size on selenium retention, we developed a dynamic 2-D reactive transport model of selenium cycling in a single idealized aggregate surrounded by a macropore. The model was developed based on flow-through-reactor experiments involving artificial soil aggregates (diameter: 2.5 cm) made of sand and containing Enterobacter cloacae SLD1a-1 that reduces Se(VI) via Se(IV) to Se(0). Aggregates were surrounded by a constant flow providing Se(VI) and pyruvate under oxic or anoxic conditions. In the model, reactions were implemented with double-Monod rate equations coupled to the transport of pyruvate, O2, and Se species. The spatial and temporal dynamics of the model were validated with data from experiments, and predictive simulations were performed covering aggregate sizes 1-2.5 cm in diameter. Simulations predict that selenium retention scales with aggregate size. Depending on O2, Se(VI), and pyruvate concentrations, selenium retention was 4-23 times higher in 2.5 cm aggregates compared to 1 cm aggregates. Under oxic conditions, aggregate size and pyruvate concentrations were found to have a positive synergistic effect on selenium retention. Promoting soil aggregation on

  5. An investigation of dynamic processes in selenium based chalcogenide glasses

    NASA Astrophysics Data System (ADS)

    Gulbiten, Ozgur

    Owing to their excellent infrared transmittance and good rheological properties, selenium based chalcogenide glasses have been materials of choice for a number of technological applications. However, chalcogenide glasses can undergo substantial structural relaxation even at room temperature due to their low glass transition temperatures. The origins of these dynamic processes and their correlation to the glass structure is therefore of fundamental and practical interest. In particular, a deep understanding of the dynamic response near the glass transition region could help elucidate the mechanism of these structural relaxation processes. The correlation between structure and dynamic properties of selenium based glass systems were therefore investigated. NMR and Raman spectroscopy measurements reveal that the structure of Asx Se1-x glass follow the chain crossing model in selenium-rich glasses but contain increasing amounts of cage molecules in arsenic-rich compositions. This structural pattern leads to systematic extrema in physical properties at the stoichiometric composition As40Se60. The dynamic response of AsxSe1-x glasses investigated by heat capacity spectroscopy shows two minima in melt fragility as a function of composition which correlate well with the dimensionality of the glassy network. The structure evolves from 2D to 3D during crosslinking of selenium chains by arsenic but reduces into a 2D layer-like structure at the stoichiometric composition. Upon precipitation of arsenic-rich cages the network first reverts back to 3D and eventually becomes a mix of 2D and 0D structural units. The presence of molecular clusters in the network is evidenced by a strong bimodal dynamic response at high arsenic contents. NMR and Raman spectroscopy measurements of GexSe1-x glasses suggest a structure composed of aggregated tetrahedral units and long selenium chains with little or no connectivity. Distinct dynamic responses of these two separated structural motifs are

  6. Selenium mobilization in a surface coal mine, Powder River Basin, Wyoming, U.S.A.

    USGS Publications Warehouse

    Dreher, G.B.; Finkelman, R.B.

    1992-01-01

    Elevated concentrations (0.6-0.9 mg/l) of selenium were detected in the groundwater of a small backfill area at a surface mine in the Powder River Basin, Wyoming. This report focuses on the source of selenium, its modes of occurrence in overburden deposits and backfill groundwater, and its fate. The immediate source of the selenium appeared to be the dissolution of preexisting soluble salts from the unsaturated zone of the overburden. The ultimate source of selenium was probably the oxidation of selenium-bearing pyrite in the geologic past. Overburden was placed partially in the saturated zone of the backfill where, upon resaturation, soluble salts dissolved in the groundwater. Water standing in the pit at the time of backfilling might have contributed to the elevated concentrations of selenium and other solutes. Selenium was found in an ash-rich coal and in clastic sediments in seven different modes of occurrence. The concentration of soluble selenium in the groundwater at this site has been decreasing since monitoring began in late 1982, and at the present rate of decrease, the concentration should drop below the State of Wyoming guideline of 0.05 mg/l for selenium in water intended for use by livestock by about mid-1992. The decrease in soluble selenium concentration may in part be due to microbially assisted reduction of selenate followed by sorption on clays and other sorbents. ?? 1992 Springer-Verlag New York Inc.

  7. 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

  8. 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.

  9. Effect of dietary selenium deficiency on the in vitro fertilizing ability of mice spermatozoa.

    PubMed

    Sánchez-Gutiérrez, M; García-Montalvo, E A; Izquierdo-Vega, J A; Del Razo, L M

    2008-08-01

    Selenium is an essential micronutrient for mammals, being integral part of antioxidant system. The aim of the study was to evaluate the effect of selenium deficiency on in vitro fertilization (IVF) capacity of spermatozoa and on oxidative stress in these cells. Male C57BL/6N mice were maintained on selenium-deficient or selenium-sufficient diets (0.02 or 0.2 ppm of selenium as selenomethionine, respectively) for 4 months. Liver glutathione peroxidase activity measurements were used to confirm selenium deficiency. Sperm quality and IVF capability among both groups were evaluated. To assess oxidative damage, lipid peroxidation as malondialdehyde production was determined in spermatozoa as well as the testes. Ultrastructural analyses of spermatozoa nuclei using transmission electron microscopy were also performed. The percentage of eggs fertilized with sperm from selenium-deficient mice was significantly decreased by approximately 67%. This reduced fertilization capacity was accompanied by increased levels of lipid peroxidation in both the testes and sperm, indicating that selenium deficiency induced oxidative stress. Consistent with this finding, spermatozoa from selenium-deficient animals exhibited altered chromatin condensation. Deficiency in dietary selenium decreases the reproductive potential of male mice and is associated with oxidative damage in spermatozoa.

  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. 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

    2016-07-15

    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.

  12. 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

  13. The effect of dietary selenium source on embryonic development in Turkeys.

    PubMed

    Stepińska, Monika; Mróz, Emilia; Jankowski, Jan

    2012-01-01

    The objective of this study was to determine the effect of dietary selenium source on the growth and development of turkey embryos, and egg hatchability. White broad-breasted BUT Big 6 turkeys (1800 females and 150 males) were placed under optimum management conditions. Turkey diets were supplemented with organic selenium, and in the other with inorganic selenium, in the amount of 0.3 ppm. Eggs intended for incubation and examination were collected in week 2, 10, 18 and 23 of the laying season. The average egg weight was higher (p < or = 0.05) in laying hens fed a diet with organic selenium than in layers receiving inorganic selenium. The rate of yolk sac retraction was faster in embryos from the group fed a diet with inorganic selenium, and it reached 0.59 of the complete yolk sac on day 25 of incubation (p < or = 0.05). Selenium source had no effect on the hatching rates of fertilized eggs, which reached 79.61% and 79.84% in laying hens fed organic and inorganic selenium, respectively. In the flocks fed diets supplemented with organic selenium, dead embryos were more frequently characterized by problems with protein utilization (19.28%) and delayed pipping (10.83%). Embryo death rates at the first mortality peak were higher in layers fed inorganic selenium than in those receiving organic selenium (15% vs. 13.5%). The second embryo mortality peak occurred earlier (day 26) in laying hens fed inorganic selenium than in those fed organic selenium (day 28).

  14. Binding and Conversion of Selenium in Candida utilis ATCC 9950 Yeasts in Bioreactor Culture.

    PubMed

    Kieliszek, Marek; Błażejak, Stanisław; Kurek, Eliza

    2017-02-25

    Selenium is considered an essential component of all living organisms. The use of yeasts as a selenium supplement in human nutrition has gained much interest over the last decade. The accumulation and biochemical transformation of selenium in yeast cells is particularly interesting to many researchers. In this article, we present the results of the determination of selenium and selenomethionine content in the biomass of feed yeast Candida utilis ATCC 9950 obtained from the culture grown in a bioreactor. The results indicated that C. utilis cells performed the biotransformation of inorganic selenium(IV) to organic derivatives (e.g., selenomethionine). Selenium introduced (20-30 mg Se(4+)∙L(-1)) to the experimental media in the form of sodium(IV) selenite (Na₂SeO₃) salt caused a significant increase in selenium content in the biomass of C. utilis,irrespective of the concentration. The highest amount of selenium (1841 μg∙gd.w.(-1)) was obtained after a 48-h culture in media containing 30 mg Se(4+)∙L(-1). The highest content of selenomethionine (238.8 μg∙gd.w.(-1)) was found after 48-h culture from the experimental medium that was supplemented with selenium at a concentration of 20 mg Se(4+)∙L(-1). Biomass cell in the cultures supplemented with selenium ranged from 1.5 to 14.1 g∙L(-1). The results of this study indicate that yeast cell biomass of C. utilis enriched mainly with the organic forms of selenium can be a valuable source of protein. It creates the possibility of obtaining selenium biocomplexes that can be used in the production of protein-selenium dietary supplements for animals and humans.

  15. Effects of selenium status and supplementary seleno-chemical sources on mouse T-cell mitogenesis.

    PubMed

    Ueno, Hitoshi; Hasegawa, Gohki; Ido, Ryoko; Okuno, Tomofumi; Nakamuro, Katsuhiko

    2008-01-01

    Although selenium is thought to be essential for various immune responses, the excess supplementation may have an adverse effect on certain immunological functions. The present study was designed to determine the effective chemical forms of selenium and their optimal levels on T-cell mitogenesis with splenic cells from mice given a selenium-deficient diet for 8 weeks to avoid effects of cellular selenium sources. Although selenium in tissues, except for spleen and thymus, was almost depleted by feeding selenium-deficient diet, the lymphoid organs still contained low levels of selenium. Both activities of cellular glutathione peroxidase (cGPx) and thioredoxin reductase (TR) in liver and splenic cells showed a tendency to decrease by selenium deficiency. However, splenic cells were tolerant against decrease of the selenoenzyme activities, and TR was also more tolerant than cGPx. T-cell proliferation of the selenium-insufficient splenic cells induced by concanavalin A was increased by addition of Na2SeO3, Na2SeO4, Na2Se, seleno-DL-cystine, seleno-L-methionine and selenocystamine. Their promoting action was observed at levels lower than 0.1 micromol/L and was completely suppressed at the highest concentration (1 micromol/L), except for selenocystamine. Na2SeO3 was one of the efficient selenocompounds for the mitogenesis, which was concomitant with the significant induction of cGPx and TR. However, recovery of cGPx activity in the selenium-insufficient cells by supplementary Na2SeO3 was only partial,while TR activity was readily recovered from selenium deficiency. These results therefore indicate that only low levels of selenium is essential for T-cell mitogenesis even in selenium-insufficient splenic cells, and TR, which is readily recovered by Na2SeO3, may be the critical enzyme.

  16. A survey of the selenium status of beef cows in Alberta.

    PubMed Central

    Campbell, J R; Jim, G K; Booker, C W; Guichon, P T

    1995-01-01

    An epidemiological survey was conducted in Alberta to measure the selenium status in blood of beef cows during the fall and to determine the risk of selenium deficiency among specific geographic regions of Alberta. Three census divisions of Alberta based on the Statistics Canada Census of Agriculture were chosen as the study areas for the project. Soils and plants in area A (Edmonton area) and area B (Calgary area) were known to be deficient in selenium, while soils and plants in area C (southeast corner of Alberta) were known to have adequate levels of selenium. Blood samples were collected from 335 cows on 29 farms from the 3 study areas. These samples were collected from cows that had recently been removed from pasture in October and November 1992. Answers to a short questionnaire pertaining to various herd characteristics and management practices were also obtained for each herd. The average value of selenium for all cows sampled was 2.20 mumol/L. The average value of selenium of cows in areas A and B was 1.93 mumol/L. The average value of selenium of cows in area C was significantly (P < 0.05) higher at 2.70 mumol/L. Nine percent of the cows in the study were considered marginal or deficient in selenium (< 1.27 mumol/L selenium). Herds located in area C, herds that were provided with supplemental feed on pasture, and herds that were pregnancy checked had higher average herd selenium values than did other herds. Cow-calf producers located in areas with selenium-deficient soils should pay particular attention to selenium supplementation for their cows. Some of the negative "geographic" effects on selenium values can be overcome by more progressive management practices. Images Figure 1. PMID:8590424

  17. 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.

  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. Investigation of the selenium metabolism in cancer cell lines.

    PubMed

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

    2011-02-01

    The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line (Jurkat E6-1) were incubated with five selenium compounds representing inorganic as well as organic Se compounds in different oxidation states. Selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), methylseleninic acid (MeSeA), selenite and selenate in the concentration range 5-100 μM were incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size exclusion chromatography and ICP-MS detection. The selenium compounds exhibited large differences in their ability to induce cell death in the three cell lines and the susceptibilities of the cell lines were different. Full recovery of selenium in the cellular fractions was observed for all Se compounds except MeSeA. Speciation analysis showed that MeSeA was completely transformed during the incubations, while metabolic conversion of the other Se compounds was limited. Production of volatile dimethyl diselenide was observed for MeSeA and MeSeCys. MeSeA, MeSeCys and selenite showed noticeable protein binding. Correlations between cell death induction and the Se compounds transformations could not be demonstrated.

  20. 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.

  1. Selenium hyperaccumulation - Astragalus bisulcatus, Cardamine hupingshanensis and Stanleya pinnata - may be useful for agromining selenium-rich soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium hyperaccumulator plants like Stanleya pinnata, Astragalus bisulcatus and the newly discovered Se-accumulator Cardamine hupingshanensis may play an important role in the Se cycle from soil to plant to human in China. Se-hyperaccumulators can be used for agromining or for phytoremediation of ...

  2. [1-(Phenylseleno)alkyl]stannanes-mixed selenium/tin analogs of acetals: preparation from alpha-hydroxystannanes and use for generating selenium-stabilized carbanions.

    PubMed

    Fernandopulle, Shimal C; Clive, Derrick L J; Yu, Maolin

    2008-08-01

    Selenium-stabilized carbanions are available by a route that does not involve acid-catalyzed formation of selenoacetals. Aldehydes are converted first into alpha-hydroxystannanes and then into alpha-(phenylseleno)stannanes. Treatment with BuLi affords selenium-stabilized carbanions by preferential Sn/Li exchange.

  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. 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

  5. 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.

  6. Selenium Exposure and Cancer Risk: an Updated Meta-analysis and Meta-regression.

    PubMed

    Cai, Xianlei; Wang, Chen; Yu, Wanqi; Fan, Wenjie; Wang, Shan; Shen, Ning; Wu, Pengcheng; Li, Xiuyang; Wang, Fudi

    2016-01-20

    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.

  7. 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

  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. Current Knowledge on the Importance of Selenium in Food for Living Organisms: A Review.

    PubMed

    Kieliszek, Marek; Błażejak, Stanisław

    2016-05-10

    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.

  10. Evaluation of selenium species in selenium-enriched pakchoi (Brassica chinensis Jusl var parachinensis (Bailey) Tsen & Lee) using mixed ion-pair reversed phase HPLC-ICP-MS.

    PubMed

    Thosaikham, Witphon; Jitmanee, Kritsana; Sittipout, Rossukon; Maneetong, Sarunya; Chantiratikul, Anut; Chantiratikul, Piyanete

    2014-02-15

    HPLC-ICP-MS based on ion-paired reversed phase chromatography for the selenium speciation using the mixture of 1-butanesulfonic acid (BA) and trifluoroacetic acid (TFA) as the mixed ion-pairing reagents was developed and applied to selenium-enriched pakchoi (Brassica chinensis Jusl var parachinensis (Bailey) Tsen & Lee). Several conditions of ion-paired reversed phase HPLC-ICP-MS, such as pH of the mobile phase, concentration of ion pairing reagents, types and length of analytical column, and flow rate of the mobile phase, were optimised for five selenium species; selenate (Se(VI)), Selenite (se(IV)), selenocysteine (SeC), Se-methylselenocysteine (SeMC) and selenomethionine (SeM). The results showed that the optimum conditions for pH, BA and TFA condition, type of separating column and flow rate, were 4.5, 8mM, 4mM, C18 (250 mm length × 4.6mm I.D) and 1.2 mL min(-1), respectively. These conditions archived separation of the organic selenium species. The limits of detection (LOD) and quantitation (LOQ) of each selenium species were lower than 5 and 16 ng Se mL(-1), respectively. Furthermore, the recoveries of most selenium species were good, except for SeC. In this research, selenium-enriched pakchoi was cultivated by supplementing inorganic selenium from selenate into sand. The result showed that inorganic selenium, SeMC, SeM and several unknown species were found in selenium-enriched pakchoi sprouts by using the proposed method. Thereby, the biotransformation of selenate in pakchoi was similar to other Brassicaceae plants such as kale and broccoli.

  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)).

  12. Prostate cancer risk and DNA damage: translational significance of selenium supplementation in a canine model.

    PubMed

    Waters, David J; Shen, Shuren; Glickman, Lawrence T; Cooley, Dawn M; Bostwick, David G; Qian, Junqi; Combs, Gerald F; Morris, J Steven

    2005-07-01

    Daily supplementation with the essential trace mineral selenium significantly reduced prostate cancer risk in men in the Nutritional Prevention of Cancer Trial. However, the optimal intake of selenium for prostate cancer prevention is unknown. We hypothesized that selenium significantly regulates the extent of genotoxic damage within the aging prostate and that the relationship between dietary selenium intake and DNA damage is non-linear, i.e. more selenium is not necessarily better. To test this hypothesis, we conducted a randomized feeding trial in which 49 elderly beagle dogs (physiologically equivalent to 62-69-year-old men) received nutritionally adequate or supranutritional levels of selenium for 7 months, in order to mimic the range of dietary selenium intake of men in the United States. Our results demonstrate an intriguing U-shaped dose-response relationship between selenium status (toenail selenium concentration) and the extent of DNA damage (alkaline Comet assay) within the prostate. Further, we demonstrate that the concentration of selenium that minimizes DNA damage in the aging dog prostate remarkably parallels the selenium concentration in men that minimizes prostate cancer risk. By studying elderly dogs, the only non-human animal model of spontaneous prostate cancer, we have established a new approach to bridge the gap between laboratory and human studies that can be used to select the appropriate dose of anticancer agents for large-scale human cancer prevention trials. From the U-shaped dose-response, it follows that not all men will necessarily benefit from increasing their selenium intake and that measurement of baseline nutrient status should be required for all individuals in prevention trials to avoid oversupplementation.

  13. 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.

  14. GKLF as a Novel Target in Selenium Chemoprevention of Prostate Cancer

    DTIC Science & Technology

    2008-02-01

    AD_________________ Award Number: W81XWH-04-1-0009 TITLE: GKLF as a Novel Target in Selenium ...Novel Target in Selenium Chemoprevention of Prostate Cancer 5b. GRANT NUMBER W81XWH-04-1-0009 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...transcription factor gut-enriched krüppel-like factor (GKLF) in mediating selenium action in the androgen receptor (AR)-null PC-3 human prostate cancer cells

  15. The Effect of Selenium Treatment on the Weight Gains of Lambs.

    PubMed

    Dale, D G; Lloyd, L E; Moxley, J E

    1962-05-01

    Two trials were conducted with lambs to evaluate the growth promoting effects of selenium administered orally at a level of 5 mg per month during the pasture season. No statistically significant effect on weight gains was found to be attributable to selenium administration in either the single lamb or the twin lamb experiment. In both trials there was a trend in the data that suggested a deleterious effect of selenium on weight gains.

  16. The Glutaredoxin GLRX-21 Functions to Prevent Selenium-Induced Oxidative Stress in Caenorhabditis elegans

    PubMed Central

    Morgan, Kathleen L.; Estevez, Annette O.; Mueller, Catherine L.; Cacho-Valadez, Briseida; Miranda-Vizuete, Antonio; Szewczyk, Nathaniel J.; Estevez, Miguel

    2010-01-01

    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-H2DCFDA, 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

  17. 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.

  18. 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.

  19. [WHO child growth standards for children 0-5 years. Percentile charts of length/height, weight, body mass index and head circumference].

    PubMed

    Woynarowska, Barbara; Palczewska, Iwona; Oblacińska, Anna

    2012-01-01

    The aim of this paper was to present the growth standards for children aged 0-5 years - which is a new tool for the assessment of health, growth and nutritional status recommended by WHO for use all over the world. These standards were elaborated in 2006 on the basis of the results of the WHO Multicentre Growth Reference Study (a longitudinal and cross-sectional survey) carried out between 1997-2003 in Brazil, Ghana, India, Norway, Oman and the USA. An innovative approach to developing growth reference was applied. Healthy children living under conditions allowing them to achieve their full genetic potential were the sample of children under study. The results showed that the growth pattern of children in their early childhood in different countries, ethnic groups and of different socioeconomic status was the same when their health and care needs were met. The new standards indicate how children should grow in all countries, rather than merely describing how they grew at a particular place and time. The WHO Child Growth Standards for Children 0-5 years were adapted and used in over 100 countries. Activities designed to adapt WHO standards in Poland were undertaken in 2009. The comparison between the growth reference for Warsaw children and WHO standards showed no differences, or very small ones. Following discussion with the participation of many experts, in 2011 recommendations concerning the implementation of these standards were signed by the Committee of Human Development and the Committee of Anthropology of the Polish Academy of Science, the Main Board of the Polish Anthropological Society, the Institute of Mother and Child, and the Institute of Food and Nutrition. The percentile charts were adapted to the set of percentiles hitherto used in Poland.

  20. Reference data and percentile curves of body composition measured with dual energy X-ray absorptiometry in healthy Chinese children and adolescents.

    PubMed

    Guo, Bin; Xu, Yi; Gong, Jian; Tang, Yongjin; Shang, Jingjie; Xu, Hao

    2015-09-01

    Measurements of body composition by dual-energy X-ray absorptiometry (DXA) have evident value in evaluating skeletal and muscular status in growing children and adolescents. This study aimed to generate age-related trends for body composition in Chinese children and adolescents, and to establish gender-specific reference percentile curves for the assessment of muscle-bone status. A total of 1541 Chinese children and adolescents aged from 5 to 19 years were recruited from southern China. Bone mineral content (BMC), lean mass (LM) and fat mass (FM) were measured for total body and total body less head (TBLH). After 14 years, total body LM was significantly higher in boys than girls (p < 0.001). However, total body FM was significantly higher in girls than boys in age groups 13-19 years (p < 0.01). Both LM and FM were consistent independent predictors of total body and subcranial bone mass in both sexes, even after adjustment for the well-known predictors of BMC. The results of multiple linear regression identified LM as the stronger predictor of total body and subcranial skeleton BMC while the fat mass contributed less. For all the subjects, significant positive correlations were observed between total body LM, height, total body BMC and subcranial BMC (p < 0.01). Subcranial BMC had a better correlation with LM than total body BMC. We have also presented gender-specific percentile curves for LM-for-height and BMC-for-LM which could be used to evaluate and follow various pediatric disorders with skeletal manifestations in this population.