Studies on the T3 suppression test with reference to the thyrodial 123I uptake in Graves' disease

International Nuclear Information System (INIS)

Yamaguchi, Takahiko; Kobayashi, Isao; Yamaguchi, Yoshiyuki; Iwashita, Akira; Inukai, Toshihiko; Ohshima, Kihachi; Shimomura, Yohnosuke; Kobayashi, Setsuo

1990-01-01

Eighty-three patients with Graves' disease had been treated with methylmercaptoimidazole (MMI). They were prescribed a maintenance dose of antithyroid drug (MMI, 5 mg/day) at the time of a T 3 suppression test. The 3-hour and 24-hour thyroidal 123 I uptake after T 3 administration (75 μg/day, 2 weeks) were measured (post T 3 uptake). In 38 patients whose post T 3 uptake was below 35% in post T 3 24-hour uptake, treatment was stopped. The T 3 suppression test was then repeated 1 and 3 months later. During a one-year follow up, 26 remained well, while 12 relapsed within 6 to 12 months. We have observed a good correlation between 3-hour uptake and 24-hour uptake of 123 I after T 3 administration (r=0.847, p 3 suppression, most patients with MMI withdrawal produced a marked overshoot of post T 3 3-hour and 24-hour uptake at one month. Retrospective analysis indicated that there was no significant difference in circulating thyroid hormone levels between remission and relapse groups. The present study provides evidence that 3-hour uptake values are able to be substituted for 24-hour uptake values during a T 3 suppression test. In addition, overshoot of thyroidal uptake after antithyroid drug withdrawal was observed in 3-hour values, similar to 24-hour values. (author)

Use of 123I in early radioiodide uptake and its suppression in children and adolescents with hyperthyroidism

International Nuclear Information System (INIS)

Lee, W.N.P.; Mpanias, P.D.; Wimmer, R.J.; Greenfield, M.A.; Kaplan, S.A.

1978-01-01

Absolute activity measurement of I-123 by coincidence counting was used to study the early thyroidal iodide uptake in 20 hyperthyroid children. Patients were pretreated either with methimazole or propylthiouracil before injection of Na 123 I. The usual method of analysis of the early uptake was modified to account for a rapidly equilibrating compartment, to give thyroidal iodide trapping rate constant (K 1 ) and absolute iodide uptake (AIU). The suppressibility of the early uptake by triiodothyronine [T 3 ) was evaluated in some patients. The upper limit of normal for K 1 was 0.03 min -1 and for AIU was 0.04 μg/min. In the hyperthyroid subjects, K 1 and AIU were in the hyperthyroid range before and after T 3 suppression. For patients with suppressible uptake, remission from hyperthyroidism was maintained for 6 mo to 2 1 / 2 yr. Only two patients with nonsuppressible uptake achieved remission from hyperthyroidism, perhaps because of coexistence of thyroiditis

Selenium Utilization Strategy by Microalgae

Directory of Open Access Journals (Sweden)

Hiroya Araie

2009-11-01

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

Effect of Sulfate on Selenium Uptake And Chemical Speciation in Convolvulus Arvensis L

Energy Technology Data Exchange (ETDEWEB)

Cruz-Jimenez, G.; Peralta-Video, J.R.; Rosa, G.de la; Meitzner, G.; Parson, J.G.; Gardea-Torresdey, J.L.

2007-08-08

Hydroponic experiments were performed to study several aspects of Se uptake by C. arvensis plants. Ten day old seedlings were exposed for eight days to different combinations of selenate (SeO{sub 4}{sup 2-}), sulfate (SO{sub 4}{sup 2-}), and selenite (SeO{sub 3}{sup 2-}). The results showed that in C. arvensis, SO{sub 4}{sup 2-} had a negative effect (P < 0.05) on SeO{sub 4}{sup 2-} uptake. However, a positive interaction produced a significant increase in SO{sub 4}{sup 2-} uptake when SeO{sub 4}{sup 2-} was at high concentration in the media. X-ray absorption spectroscopy studies showed that C. arvensis plants converted more than 70% of the supplied SeO{sub 3}{sup 2-} into organoselenium compounds. However, only approximately 50% of the supplied SeO{sub 4}{sup 2-} was converted into organoselenium species while the residual 50% remained in the inorganic form. Analysis using LC-XANES fittings confirmed that the S metabolic pathway was affected by the presence of Se. The main Se compounds that resembled those Se species identified in C. arvensis were Se-cystine, Se-cysteine, SeO{sub 3}{sup 2-}, and SeO{sub 4}{sup 2-}, whereas for S the main compounds were cysteine, cystine, oxidized glutathione, reduced glutathione, and SO{sub 4}{sup 2-}. The results of these studies indicated that C. arvensis could be considered as a possible option for the restoration of soil moderately contaminated with selenium even in the presence of sulfate.

Relationship between glutation peroxidase (GSH-PX) activity and the uptake of 75-Se by erytrocytes for practical assesment of selenium status in dairy cows

International Nuclear Information System (INIS)

Danius, J.

1988-01-01

An experiment to study the relationship between glutation peroxidase (GSH-Px) activity and the uptake of 75-Se by erytrocytes was conducted for practical assesment of selenium status in Holstein-Friesian (HF) dairy cows. The blood used in the experiment was stored in refrigerator for 7 and 10 days. Radioselenium with a specific activity at about 0.84 mCi/m was used. A high negative correlatin (r = -0.86 and r = -0.98) was found between red blood cell GSH-Px activity and red blood cell uptake of 75-Se. Results indicated that red blood cell uptake of 75-Se can be used for determination of Se status in dairy cattle, although some factors which might affect red blood cell uptake of 75-Se should be calculated first. (author). 21 refs, 2 figs

Quantification of pharmaceutical peptides using selenium as an elemental detection label

DEFF Research Database (Denmark)

Møller, Laura Hyrup; Gabel-Jensen, Charlotte; Franzyk, Henrik

2014-01-01

analysis of cell samples by LC-ICP-MS showed mainly uptake of the intact peptides, while the amount of intact peptides in cell lysates was semi-quantitatively determined. The selenium-containing penetratin analogues were to some extent degraded in pure cell medium, while an extensive degradation......The aim of the present work was to demonstrate how selenium labelling of a synthetic cell-penetrating peptide may be employed in evaluation of stability and quantitative estimation of cellular uptake by inductively coupled plasma mass spectrometry (ICP-MS). Two analogues of the cell...

Studies on the T sub 3 suppression test with reference to the thyrodial sup 123 I uptake in Graves' disease; Comparison of 24-hour and 3-hour uptake

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, Takahiko; Kobayashi, Isao; Yamaguchi, Yoshiyuki; Iwashita, Akira; Inukai, Toshihiko; Ohshima, Kihachi; Shimomura, Yohnosuke; Kobayashi, Setsuo (Gunma Univ., Maebashi (Japan). School of Medicine)

1990-06-01

Eighty-three patients with Graves' disease had been treated with methylmercaptoimidazole (MMI). They were prescribed a maintenance dose of antithyroid drug (MMI, 5 mg/day) at the time of a T{sub 3} suppression test. The 3-hour and 24-hour thyroidal {sup 123}I uptake after T{sub 3} administration (75 {mu}g/day, 2 weeks) were measured (post T{sub 3} uptake). In 38 patients whose post T{sub 3} uptake was below 35% in post T{sub 3} 24-hour uptake, treatment was stopped. The T{sub 3} suppression test was then repeated 1 and 3 months later. During a one-year follow up, 26 remained well, while 12 relapsed within 6 to 12 months. We have observed a good correlation between 3-hour uptake and 24-hour uptake of {sup 123}I after T{sub 3} administration (r=0.847, p<0.001). In 38 patients who showed positive T{sub 3} suppression, most patients with MMI withdrawal produced a marked overshoot of post T{sub 3} 3-hour and 24-hour uptake at one month. Retrospective analysis indicated that there was no significant difference in circulating thyroid hormone levels between remission and relapse groups. The present study provides evidence that 3-hour uptake values are able to be substituted for 24-hour uptake values during a T{sub 3} suppression test. In addition, overshoot of thyroidal uptake after antithyroid drug withdrawal was observed in 3-hour values, similar to 24-hour values. (author).

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

International Nuclear Information System (INIS)

Munier-Lamy, C.; Deneux-Mustin, S.; Mustin, C.; Merlet, D.; Berthelin, J.; Leyval, C.

2007-01-01

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

Biofortification and phytoremediation of selenium in China

Science.gov (United States)

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

Suppression of phytohemagglutinin-induction of thymidine uptake in guinea pig lymphocytes by methylglyoxal bis(guanylhydrazone) treatment.

Science.gov (United States)

Otani, S; Matsui, I; Morisawa, S

1977-10-18

Treatment with methylglyoxal bis(guanylhydrazone), a specific inhibitor of S-adenosylmethionine decarboxylase (EC 4.1.1.50), suppressed the phytohemagglutinin-induction of [3H]thymidine uptake by guinea pig lymphocytes. The kinetics of [3H]thymidine uptake revealed that the Km value for thymidine was not changed, but the V value was markedly lowered by the methylglyoxal bis(guanylhydrazone) treatment. The induction of ATP: thymidine 5'-phosphotransferase (EC 2.7.1.75) (thymidine kinase) activity by phytohemagglutinin was suppressed to about the same extent as the induction of thymidine uptake. These suppressions were dependent on the methylglyoxal bis(guanylhydrazone) doses and on duration of the methylglyoxal bis(guanylhydrazone) treatment. Analysis of [3H]thymidine labelled compounds of the acid-soluble fraction showed that conversion of thymidine to thymidine 5'-triphosphate was inhibited by the methylglyoxal bis(guanylhydrazone) treatment. DNA polymerase activity was less inhibited by the methylglyoxal bis(guanylhydrazone) treatment in comparison with the methylglyoxal bis(guanylhydrazone) inhibition of thymidine uptake by whole cells. These results strongly suggested that blocking of polyamine accumulation by the methylglyoxal bis(guanylhydrazone) treatment influenced phytohemagglutinin induction of thymidine phosphorylation, resulting in a decrease of thymidine incorporation into DNA.

Nuclear-based methods for the study of selenium

International Nuclear Information System (INIS)

Spyrou, N.M.; Akanle, O.A.; Dhani, A.

1988-01-01

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

Response of selenium changes in blood using cyclic activation analysis

International Nuclear Information System (INIS)

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

1986-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Andrahennadi, R.; Wayland, M.; Pickering, I.J.

2009-05-28

Selenium contamination in the environment is a widespread problem affecting insects and other wildlife. Insects occupy a critical middle link and aid in trophic transfer of selenium in many terrestrial and freshwater food chains, but the mechanisms of selenium uptake through the food chain are poorly understood. In particular, biotransformation of selenium by insects into different chemical forms will greatly influence how toxic or benign the selenium is to that organism or to its predators. We have used X-ray absorption spectroscopy (XAS) to identify the chemical form of selenium in insects inhabiting selenium contaminated streams near Hinton, Alberta (Canada). Selenium K near-edge spectra indicate a variability of selenium speciation among the insects that included mayflies (Ephemeroptera), stoneflies (Plecoptera), caddisflies (Trichoptera), and craneflies (Diptera). Higher percentages of inorganic selenium were observed in primary consumers, detritivores, and filter feeders than in predatory insects. Among the organic forms of selenium, organic selenides constituted a major fraction in most organisms. A species modeled as trimethylselenonium was observed during the pupal stage of caddisflies. These results provide insights into how the insects cope with their toxic cargo, including how the selenium is biotransformed into less toxic forms and how it can be eliminated from the insects. More broadly, this study demonstrates the strengths of XAS to probe the effects of heavy elements at trace levels in insects from the field.

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

Energy Technology Data Exchange (ETDEWEB)

Ruwandi Andrahennadi; Mark Wayland; Ingrid J. Pickering [University of Saskatchewan, Saskatoon, SK (Canada). Department of Geological Sciences

2007-11-15

Selenium contamination in the environment is a widespread problem affecting insects and other wildlife. Insects occupy a critical middle link and aid in trophic transfer of selenium in many terrestrial and freshwater food chains, but the mechanisms of selenium uptake through the food chain are poorly understood. In particular, biotransformation of selenium by insects into different chemical forms will greatly influence how toxic or benign the selenium is to that organism or to its predators. We have used X-ray absorption spectroscopy (XAS) to identify the chemical form of selenium in insects inhabiting selenium contaminated streams near Hinton, Alberta (Canada). Selenium K near-edge spectra indicate a variability of selenium speciation among the insects that included mayflies (Ephemeroptera), stoneflies (Plecoptera), caddisflies (Trichoptera), and craneflies (Diptera). Higher percentages of inorganic selenium were observed in primary consumers, detritivores, and filter feeders than in predatory insects. Among the organic forms of selenium, organic selenides constituted a major fraction in most organisms. A species modeled as trimethylselenonium was observed during the pupal stage of caddisflies. These results provide insights into how the insects cope with their toxic cargo, including how the selenium is biotransformed into less toxic forms and how it can be eliminated from the insects. More broadly, this study demonstrates the strengths of XAS to probe the effects of heavy elements at trace levels in insects from the field.

Inhibition of BRD4 suppresses tumor growth and enhances iodine uptake in thyroid cancer

International Nuclear Information System (INIS)

Gao, Xuemei; Wu, Xinchao; Zhang, Xiao; Hua, Wenjuan; Zhang, Yajing; Maimaiti, Yusufu; Gao, Zairong; Zhang, Yongxue

2016-01-01

Thyroid cancer is a common malignancy of the endocrine system. Although radioiodine "1"3"1I treatment on differentiated thyroid cancer is widely used, many patients still fail to benefit from "1"3"1I therapy. Therefore, exploration of novel targeted therapies to suppress tumor growth and improve radioiodine uptake remains necessary. Bromodomain-containing protein 4 (BRD4) is an important member of the bromodomain and extra terminal domain family that influences transcription of downstream genes by binding to acetylated histones. In the present study, we found that BRD4 was up-regulated in thyroid cancer tissues and cell lines. Inhibition of BRD4 in thyroid cancer cells by JQ1 resulted in cell cycle arrest at G0/G1 phase and enhanced "1"3"1I uptake in vitro and suppressed tumor growth in vivo. Moreover, JQ1 treatment suppressed C-MYC but enhanced NIS expression. We further demonstrated that BRD4 was enriched in the promoter region of C-MYC, which could be markedly blocked by JQ1 treatment. In conclusion, our findings revealed that the aberrant expression of BRD4 in thyroid cancer is possibly involved in tumor progression, and JQ1 is potentially an effective chemotherapeutic agent against human thyroid cancer. - Highlights: • BRD4 is upregulated in thyroid cancer tissues and cell lines. • Inhibition of BRD4 induced cell cycle arrest and enhanced radioiodine uptake in vitro and impaired tumor growth in vivo. • JQ1 suppressed the expression of C-MYC and promoted the expression of NIS and P21. • JQ1 attenuated the recruitment of BRD4 to MYC promoter in thyroid cancer.

Inhibition of BRD4 suppresses tumor growth and enhances iodine uptake in thyroid cancer

Energy Technology Data Exchange (ETDEWEB)

Gao, Xuemei [Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, Hubei Province (China); Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Wu, Xinchao [Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Zhang, Xiao; Hua, Wenjuan; Zhang, Yajing [Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, Hubei Province (China); Maimaiti, Yusufu [Department of Thyroid and Breast Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Gao, Zairong, E-mail: gaobonn@163.com [Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, Hubei Province (China); Zhang, Yongxue [Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei Province (China); Hubei Province Key Laboratory of Molecular Imaging, Wuhan 430022, Hubei Province (China)

2016-01-15

Thyroid cancer is a common malignancy of the endocrine system. Although radioiodine {sup 131}I treatment on differentiated thyroid cancer is widely used, many patients still fail to benefit from {sup 131}I therapy. Therefore, exploration of novel targeted therapies to suppress tumor growth and improve radioiodine uptake remains necessary. Bromodomain-containing protein 4 (BRD4) is an important member of the bromodomain and extra terminal domain family that influences transcription of downstream genes by binding to acetylated histones. In the present study, we found that BRD4 was up-regulated in thyroid cancer tissues and cell lines. Inhibition of BRD4 in thyroid cancer cells by JQ1 resulted in cell cycle arrest at G0/G1 phase and enhanced {sup 131}I uptake in vitro and suppressed tumor growth in vivo. Moreover, JQ1 treatment suppressed C-MYC but enhanced NIS expression. We further demonstrated that BRD4 was enriched in the promoter region of C-MYC, which could be markedly blocked by JQ1 treatment. In conclusion, our findings revealed that the aberrant expression of BRD4 in thyroid cancer is possibly involved in tumor progression, and JQ1 is potentially an effective chemotherapeutic agent against human thyroid cancer. - Highlights: • BRD4 is upregulated in thyroid cancer tissues and cell lines. • Inhibition of BRD4 induced cell cycle arrest and enhanced radioiodine uptake in vitro and impaired tumor growth in vivo. • JQ1 suppressed the expression of C-MYC and promoted the expression of NIS and P21. • JQ1 attenuated the recruitment of BRD4 to MYC promoter in thyroid cancer.

Selenium accumulation and metabolism in algae.

Science.gov (United States)

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

2017-08-01

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

Significant suppression of myocardial (18)F-fluorodeoxyglucose uptake using 24-h carbohydrate restriction and a low-carbohydrate, high-fat diet.

Science.gov (United States)

Kobayashi, Yasuhiro; Kumita, Shin-ichiro; Fukushima, Yoshimitsu; Ishihara, Keiichi; Suda, Masaya; Sakurai, Minoru

2013-11-01

(18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is a useful tool for evaluating inflammation. Because, myocardial-FDG uptake occurs with diverse physiology, it should be suppressed during evaluation of myocardial inflammation by FDG-PET/CT. Diets inducing fat-based metabolism, such as a low-carbohydrate, high-fat diet (LCHF), are used in uptake-suppression protocols. However, a complete suppression of myocardial-FDG uptake has not been established. Hence, we assessed the efficacy of 24-h carbohydrate restriction along with an LCHF diet compared to that of the conventional protocol in suppressing myocardial-FDG uptake and also compared fat and glucose metabolism between these protocols. Fourteen healthy volunteers agreed to undergo >24-h carbohydrate restriction (glucose, vs. 2.98 [1.76-6.43], p=0.001). Target-to-background ratios [myocardium-to-blood ratio (MBR), myocardium-to-lung ratio (MLR), and myocardium-to-liver ratio (MLvR)] were also significantly lower with the diet-preparation protocol [MBR: 0.75 (0.68-0.84) vs. 1.63 (0.98-4.09), pvs. 4.54 (2.53-12.78), p=0.004; MLvR: 0.48 (0.44-0.56) vs. 1.11 (0.63-2.32), p=0.002]. Only insulin levels were significantly different between the subjects in each protocol group (11.3 [6.2-15.1] vs. 3.9 [2.9-6.2]). Carbohydrate restriction together with an LCHF supplement administered 1h before FDG significantly suppressed myocardial-FDG uptake. FFAs and insulin might not directly affect myocardial-FDG uptake. Copyright © 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Uptake and specification of selenium in garlic cultivated in soil amended with symbiotic fungi (mycorrhiza) and selenate

NARCIS (Netherlands)

Larsen, E.H.; Lobinski, R.; Burger-Meijer, K.; Hansen, M.; Ruzik, R.; Mazurowska, L.; Rasmussen, P.H.; Sloth, J.J.; Scholten, O.E.; Kik, C.

2006-01-01

The scope of the work was to investigate the influence of selenate fertilisation and the addition of symbiotic fungi (mycorrhiza) to soil on selenium and selenium species concentrations in garlic. The selenium species were extracted from garlic cultivated in experimental plots by proteolytic

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

Science.gov (United States)

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

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

Removal of dangling bonds and surface states on silicon (001) with a monolayer of selenium

International Nuclear Information System (INIS)

Tao Meng; Udeshi, Darshak; Basit, Nasir; Maldonado, Eduardo; Kirk, Wiley P.

2003-01-01

Dangling bonds and surface states are inherent to semiconductor surfaces. By passivating dangling bonds on the silicon (001) surface with a monolayer of selenium, surface states are removed from the band gap. Magnesium contacts on selenium-passivated silicon (001) behave ohmically, as expected from the work function of magnesium and the electron affinity of silicon. After rapid thermal annealing and hot-plate annealing, magnesium contacts on selenium-passivated silicon (001) show better thermal stability than on hydrogen-passivated silicon (001), which is attributed to the suppression of silicide formation by selenium passivation

Selenium as an alternative peptide label - comparison to fluorophore-labelled penetratin

DEFF Research Database (Denmark)

Hyrup Møller, Laura; Bahnsen, Jesper Søborg; Nielsen, Hanne Mørck

2015-01-01

lysates, primarily the intact peptide (PenMSe, TAMRA-PenMSe or TAMRA-Pen) was observed. Selenium labelling caused minimal alteration of the physicochemical properties of the peptide and allowed for absolute quantitative determination of cellular uptake by inductively coupled plasma mass spectrometry......In the present study, the impact on peptide properties of labelling peptides with the fluorophore TAMRA or the selenium (Se) containing amino acid SeMet was evaluated. Three differently labelled variants of the cell-penetrating peptide (CPP) penetratin (Pen) were synthesized, PenMSe, TAMRA....... Selenium is thus proposed as a promising alternative label for quantification of peptides in general, altering the properties of the peptide to a minor extent as compared to commonly used peptide labels....

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

International Nuclear Information System (INIS)

Edwardly, J.S.

1981-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Burger, Joanna; Gochfeld, Michael; Donio, Mark [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey 08854-8082 (United States); Environmental and Occupational Medicine, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854 (United States); Jeitner, Christian; Pittfield, Taryn [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey 08854-8082 (United States); Consortium for Risk Evaluation with Stakeholder Participation (CRESP), Rutgers University and Vanderbilt University, Nashville, Tennessee 37235 (United States)

2012-07-01

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

Underlying mechanisms and effects of hydrated lime and selenium application on cadmium uptake by rice (Oryza sativa L.) seedlings.

Science.gov (United States)

Huang, Gaoxiang; Ding, Changfeng; Guo, Fuyu; Li, Xiaogang; Zhang, Taolin; Wang, Xingxiang

2017-08-01

A pot experiment was conducted to investigate the effects of selenium (Se) and hydrated lime (Lime), applied alone or simultaneously (Se+Lime), on growth and cadmium (Cd) uptake and translocation in rice seedlings grown in an acid soil with three levels of Cd (slight, mild, and moderate contamination). In the soil with 0.41 mg kg -1 Cd (slight Cd contamination), Se addition alone significantly decreased Cd accumulation in the root and shoot by 35.3 and 40.1%, respectively, but this tendency weakened when Cd level in the soil increased. However, Se+Lime treatment effectively reduced Cd accumulation in rice seedlings in the soil with higher Cd levels. The results also showed that Se application alone strongly increased Cd concentration in the iron plaque under slight Cd contamination, which was suggested as the main reason underlying the inhibition of Cd accumulation in rice seedlings. Se+Lime treatment also increased the ability of the iron plaques to restrict Cd uptake by rice seedlings across all Cd levels and dramatically decreased the available Cd concentration in the soil. These results suggest that Se application alone would be useful in the soil with low levels of Cd, and the effect would be enhanced when Se application is combined with hydrated lime at higher Cd levels.

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

Science.gov (United States)

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

2016-01-01

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

Concentrations of boron, molybdenum, and selenium in chinook salmon

Science.gov (United States)

Hamilton, Steven J.; Wiedmeyer, Raymond H.

1990-01-01

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

Selenium Sulfide

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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 ...

Effect of selenium-enriched organic material amendment on selenium fraction transformation and bioavailability in soil.

Science.gov (United States)

Wang, Dan; Dinh, Quang Toan; Anh Thu, Tran Thi; Zhou, Fei; Yang, Wenxiao; Wang, Mengke; Song, Weiwei; Liang, Dongli

2018-05-01

To exploit the plant byproducts from selenium (Se) biofortification and reduce environmental risk of inorganic Se fertilizer, pot experiment was conducted in this study. The effects of Se-enriched wheat (Triticum aestivum L.) straw (WS + Se) and pak choi (Brassica chinensis L.) (P + Se) amendment on organo-selenium speciation transformation in soil and its bioavailability was evaluated by pak choi uptake. The Se contents of the cultivated pak choi in treatments amended with the same amount of Se-enriched wheat straw and pak choi were 1.7 and 9.7 times in the shoots and 2.3 and 6.3 times in the roots compared with control treatment. Soil respiration rate was significantly increased after all organic material amendment in soil (p organic materials and thus resulted in soluble Se (SOL-Se), exchangeable Se (EX-Se), and fulvic acid-bound Se (FA-Se) fraction increasing by 25.2-29.2%, 9-13.8%, and 4.92-8.28%, respectively. In addition, both Pearson correlation and cluster analysis showed that EX-Se and FA-Se were better indicators for soil Se availability in organic material amendment soils. The Marquardt-Levenberg Model well described the dynamic kinetics of FA-Se content after Se-enriched organic material amendment in soil mainly because of the mineralization of organic carbon and organo-selenium. The utilization of Se in P + Se treatment was significantly higher than those in WS + Se treatment because of the different mineralization rates and the amount of FA-Se in soil. Se-enriched organic materials amendment can not only increase the availability of selenium in soil but also avoid the waste of valuable Se source. Copyright © 2018 Elsevier Ltd. All rights reserved.

Synergistic Effects of SAM and Selenium Compounds on Proliferation, Migration and Adhesion of HeLa Cells.

Science.gov (United States)

Sun, Licui; Zhang, Jianxin; Yang, Qiu; Si, Yang; Liu, Yiqun; Wang, Qin; Han, Feng; Huang, Zhenwu

2017-08-01

To determine the antitumor activities and molecular mechanism of selenium compounds in HeLa cells. Western blotting was used to detect ERK and AKT activation in HeLa cells induced by selenium compounds selenomethionine (SeMet), methylselenocysteine (MeSeCys) and methylseleninic acids (MeSeA). Using MTT, wound-healing and Matrigel adhesion assays, the antitumor effects of SAM and selenium compounds were evaluated in HeLa cells. MeSeA inhibited ERK and AKT signaling pathways and suppressed the proliferation (peffects compared to the other treatments. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Production of urinary selenium metabolites in the rat following 75SeO32- administration

International Nuclear Information System (INIS)

Kiker, K.W.; Burk, R.F.

1974-01-01

Urinary metabolites of 75 Se were studied in male Holtzmann rats fed a Torula yeast diet with either no selenium (basal) or 0.5 ppM selenium (selenium) added as sodium selenite. The animals were anesthetized, a ureter was cannulated, and 20 μCi of 75 SeO 3 2- were injected intraportally. Only a small fraction (1.3 percent) of the injected 75 Se was excreted in 6 h by animals fed the basal diet but 13.3 percent was excreted by animals fed the selenium diet. Paper chromatography showed that both groups excreted mostly inorganic 75 Se in the first 10 min. A decrease in 75 Se excretion followed, and then, 70 min after the collection was started, the selenium diet group had an increase in 75 Se excretion which persisted for the rest of the 6 h and consisted mainly of the organic metabolites trimethylselenonium ion and U-2. 75 Se excretion remained low in the basal diet group. Liver uptake and release of 75 Se in the 1 h following intraperitoneal 75 SeO 3 2- injection was much greater in the selenium diet rats than in the basal diet rats. These results suggest that the greater excretion of 75 Se by rats fed the selenium diet than that by rats fed the basal diet was due to increased production of organic urinary selenium metabolites by the liver. (U.S.)

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

Science.gov (United States)

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

2017-07-01

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

[Selenium treatment in thyreopathies].

Science.gov (United States)

Sotak, Štefan

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

Relationships between selenium and mercury in the fruiting bodies of some mushrooms growing in Poland

Science.gov (United States)

Falandysz, J.; Kubotal, R.; Kunito, T.; Bielawski, L.; Brzostowski, A.; Gucia, M.; Jedrusiak, A.; Lipka, K.; Tanabe, S.

2003-05-01

The relationships between concentrations of total selenium and mercury were investigated for the whole fruiting bodies, caps and/or stalks of King bolete (Boletus edulis), Brown birch scaber stalk (Leccinum scabrum), Parasol mushroom (Macrolepiota procera), Poison pax (Paxillus involutus) and Fly agaric (Amatiita niuscaria) collected from the various sites in Poland. The mushroom species examined varied largely due to the contents and proportions between the total selenium and mercury concentrations, what seems to indicate on species-dependent strategy of co-uptake and accumulation of these elements.

Selenium

Science.gov (United States)

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

Diselenolane-mediated cellular uptake.

Science.gov (United States)

Chuard, Nicolas; Poblador-Bahamonde, Amalia I; Zong, Lili; Bartolami, Eline; Hildebrandt, Jana; Weigand, Wolfgang; Sakai, Naomi; Matile, Stefan

2018-02-21

The emerging power of thiol-mediated uptake with strained disulfides called for a move from sulfur to selenium. We report that according to results with fluorescent model substrates, cellular uptake with 1,2-diselenolanes exceeds uptake with 1,2-dithiolanes and epidithiodiketopiperazines with regard to efficiency as well as intracellular localization. The diselenide analog of lipoic acid performs best. This 1,2-diselenolane delivers fluorophores efficiently to the cytosol of HeLa Kyoto cells, without detectable endosomal capture as with 1,2-dithiolanes or dominant escape into the nucleus as with epidithiodiketopiperazines. Diselenolane-mediated cytosolic delivery is non-toxic (MTT assay), sensitive to temperature but insensitive to inhibitors of endocytosis (chlorpromazine, methyl-β-cyclodextrin, wortmannin, cytochalasin B) and conventional thiol-mediated uptake (Ellman's reagent), and to serum. Selenophilicity, the extreme CSeSeC dihedral angle of 0° and the high but different acidity of primary and secondary selenols might all contribute to uptake. Thiol-exchange affinity chromatography is introduced as operational mimic of thiol-mediated uptake that provides, in combination with rate enhancement of DTT oxidation, direct experimental evidence for existence and nature of the involved selenosulfides.

Thyroid suppression test with dextrothyroxine

International Nuclear Information System (INIS)

Rosenthal, D.; Fridman, J.; Ribeiro, H.B.

1978-01-01

The classic thyroid suppression test with triiodothyronine (l-T 3 ) has been shown to be efficient as an auxiliary method in the diagnosis of thyroid diseases, but should not be performed on elderly patients or on those with heart disease or a tendency to tachycardia. Since these subjects seem able to support a short period of dextro-thyronine (d-T 4 ) feeding, we compared the effect of d-T 4 and l-T 3 on the 24 hours thyroid uptake in euthyroid and hyperthyroid subjects. After basal radio-iodine uptake determination, 99 patients without hyperthyroidism and 27 with Graves' disease were randomly divided in 2 groups; one received 100μg of l-T 3 per day and the other 4 mg of d-T 4 per day, both groups being treated for a period of 10 days. At the end of this suppression period the 24 hours radio-iodine uptake was measured again and the percentual suppression index (S.I.) calculated. Since the comparison of the two groups showed no difference between the suppressive effect of l-T 3 and d-T 4 in euthyroid subjects, while dextro-thyronine, as levo-triiodothyronine, did not suppress the 24 hours uptake of hyperthyroid patients, l-T 3 or d-T 4 can be used interchangeably to test thyroid suppressibility. In the euthyroid subjects the normal range for the post-suppression uptake was 0-17.1% and for the suppression index 54,7.100% [pt

The response of broccoli (Brassica oleracea convar. italica) varieties on foliar application of selenium: uptake, translocation, and speciation.

Science.gov (United States)

Šindelářová, Kristýna; Száková, Jiřina; Tremlová, Jana; Mestek, Oto; Praus, Lukáš; Kaňa, Antonín; Najmanová, Jana; Tlustoš, Pavel

2015-01-01

A model small-scale field experiment was set up to investigate selenium (Se) uptake by four different varieties of broccoli plants, as well as the effect of Se foliar application on the uptake of essential elements for plants calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and zinc (Zn). Foliar application of sodium selenate (Na2SeO4) was carried out at two rates (25 and 50 g Se/ha), and an untreated control variant was included. Analyses of individual parts of broccoli were performed, whereby it was found that Se in the plant accumulates mainly in the flower heads and slightly less in the leaves, stems, and roots, regardless of the Se rate and broccoli variety. In most cases, there was a statistically significant increase of Se content in all parts of the plant, while there was no confirmed systematic influence of the addition of Se on the changing intake of other monitored elements. Selenization of broccoli leads to an effective increase in the Se content at a rate of 25 g/ha, whereas the higher rate did not result in a substantial increase of Se content compared to the lower rate in all varieties. Therefore, the rate of 25 g/ha can be recommended as effective to produce broccoli with an increased Se content suitable for consumption. Moreover, Se application resulted in an adequate increase of the main organic compounds of Se, such as selenocystine (SeCys2), selenomethionine (SeMet), and Se-methylselenocysteine (Se-MeSeCys).

Selenium and Human Health

Directory of Open Access Journals (Sweden)

M Abedi

2013-04-01

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

Suppressive effect of nobiletin and epicatechin gallate on fructose uptake in human intestinal epithelial Caco-2 cells.

Science.gov (United States)

Satsu, Hideo; Awara, Sohei; Unno, Tomonori; Shimizu, Makoto

2018-04-01

Inhibition of excessive fructose intake in the small intestine could alleviate fructose-induced diseases such as hypertension and non-alcoholic fatty liver disease. We examined the effect of phytochemicals on fructose uptake using human intestinal epithelial-like Caco-2 cells which express the fructose transporter, GLUT5. Among 35 phytochemicals tested, five, including nobiletin and epicatechin gallate (ECg), markedly inhibited fructose uptake. Nobiletin and ECg also inhibited the uptake of glucose but not of L-leucine or Gly-Sar, suggesting an inhibitory effect specific to monosaccharide transporters. Kinetic analysis further suggested that this reduction in fructose uptake was associated with a decrease in the apparent number of cell-surface GLUT5 molecules, and not with a change in the affinity of GLUT5 for fructose. Lastly, nobiletin and ECg suppressed the permeation of fructose across Caco-2 cell monolayers. These findings suggest that nobiletin and ECg are good candidates for preventing diseases caused by excessive fructose intake.

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

Directory of Open Access Journals (Sweden)

LIU Yuan-yuan

2014-12-01

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

Treating chronic arsenic toxicity with high selenium lentil diets

Energy Technology Data Exchange (ETDEWEB)

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

2013-10-01

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

Treating chronic arsenic toxicity with high selenium lentil diets

International Nuclear Information System (INIS)

Sah, Shweta; Vandenberg, Albert; Smits, Judit

2013-01-01

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

Selenium content of mushrooms.

Science.gov (United States)

Stijve, T

1977-07-29

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

Selenium in edible mushrooms.

Science.gov (United States)

Falandysz, Jerzy

2008-01-01

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

Ecological aspects of selenium and tellurium in human and animal health

Energy Technology Data Exchange (ETDEWEB)

Frost, D V; Ingvoldstad, D

1975-01-01

Animal and human studies indicate that selenium inadequacy, in part, underlies various chronic diseases. Epidemiologic evidence suggests that cancer and heart disease are most common where ambient Se availability is low. Plant Se uptake and Se blood levels are inverse to human cancer mortality. As the active group in glutathione peroxidase, Se/sup -2/ inhibits aberrant oxidations which lead to chronic diseases. It binds heavy metals, and with tocopherol maintains tissue integrity. Sulfur dioxide fallout from the atmosphere, resulting from fossil fuel burning, may diminish the nutritional availability of selenium by diminishing plant uptake. Intensive ruminant grazing returns unavailable Se/sup 0/ to soils. Trimethyl selenium ion, as excreted by animals, also appears to be unavailable to plants. Modern fertilization practices and the effect of buildup of sulfates in the soil, due to acid rains, both appear to lessen the availability of Se to plants. SeO/sub 2/ added to the atmosphere from combustion and volcanic activity react with SO/sub 2/ to yield Se/sup 0/. This is presumed to fall out as particles from the air. How traces of Se are otherwise carried in air, explaining its enrichment in some areas, is unknown. The New Zealand experience with Se inadequacy in animals and man may be repeated in other parts of the world. Se inadequacy is far more of a human health problem than Se toxicity. There are no known adverse health effects from tellurium, other than tellurium breath. 164 references, 5 figures, 3 tables.

Determination of sub-microgram amounts of selenium in geological materials by atomic-absorption spectrophotometry with electrothermal atomisation after solvent extraction

Science.gov (United States)

Sanzolone, R.F.; Chao, T.T.

1981-01-01

An atomic-absorption spectrophotometric method with electrothermal atomisation has been developed for the determination of selenium in geological materials. The sample is decomposed with a mixture of nitric, perchloric and hydrofluoric acids and heated with hydrochloric acid to reduce selenium to selenium (IV). Selenium is then extracted into toluene from a hydrochloric acid - hydrobromic acid medium containing iron. A few microlitres of the toluene extract are injected into a carbon rod atomiser, using a nickel solution as a matrix modifier. The limits of determination are 0.2-200 p.p.m. of selenium in a geological sample. For concentrations between 0.05 and 0.2 p.p.m., back-extraction of the selenium into dilute hydrochloric acid is employed before atomisation. Selenium values for reference samples obtained by replicate analysis are in general agreement with those reported by other workers, with relative standard deviations ranging from 4.1 to 8.8%. Recoveries of selenium spiked at two levels were 98-108%. Major and trace elements commonly encountered in geological materials do not interfere. Arsenic has a suppressing effect on the selenium signals, but only when its concentration is greater than 1000 p.p.m. Nitric acid interferes seriously with the extraction of selenium and must be removed by evaporation in the sample-digestion step.

Impacts of phosphate mining on trophic level- and spatial variation of selenium and radium-226 on Florida waterbirds

International Nuclear Information System (INIS)

Myers, O.B.; O'Meara, T.E.

1993-01-01

More than 74,000 ha of the Florida landscape have been disturbed by phosphate mining operations. These operations redistribute radionuclides in the uranium-238 decay series and other potentially toxic trace elements contained in the ore matrix, making them more available for uptake by wetland birds. The authors inventoried levels of radium-226 and selenium in the tissue of wood ducks, mottled ducks, common moorhens, and double-crested cormorants collected from reference areas and from phosphate-mine wetlands. Bones of waterfowl contained from 3--4 times more radium-226 than in individuals collected at reference areas. Radium-226 in moorhen and cormorant bones were less strongly affected by mining. Waterfowl muscle tissue contained 1-2 orders of magnitude less radium-226 than in bone. Selenium concentrations were significantly higher in avian liver and kidney tissues collected from phosphate-mine wetlands compared to reference wetlands. Cormorants accumulated up to 80 ppm selenium in liver. As many as 20% of cormorants from phosphate-mine wetlands contained liver selenium concentrations at levels which have caused reproduction problems in other avian species. Waterfowl and moorhens tissues contained less selenium than cormorants, but phosphate-mine birds contained significantly more selenium than reference area birds

Binary mixtures of mercury/ selenium, and lead/selenium

African Journals Online (AJOL)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-06-04

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

The fungistatic activity of organic selenium and its application to the production of cultivated mushrooms Agaricus bisporus and Pleurotus spp.

Directory of Open Access Journals (Sweden)

Savic Milena

2012-01-01

Full Text Available The activity of organic selenium against pathogenic molds and its use as a potential selenium source in the production of enriched mushrooms were examined. The effect of commercial selenized yeast on mycelia growth was examined using a method with mycelia disks and a well diffusion method. For mushroom enrichment, different concentrations of selenium were added to a growth substrate. The results presented in this paper suggest that the most suitable concentration of selenized yeast that inhibits the growth of the mycopathogenic molds is 70-100 mg/kg of selenium. With the addition of this concentration to the substrate, mushroom fruit bodies will uptake a high level of selenium, about 100 μg/g for Pleurotus spp., and 200 μg/g for Agaricus bisporus in dry weight of the mushroom. Thereby a double effect in the cultivation of mushrooms is achieved. [Projekat Ministarstva nauke Republike Srbije, br. III 46010 and br. III46001

Uptake of 32P and 86Rb as influenced by temperature, transpiration suppress and shading treatment in rice plants

International Nuclear Information System (INIS)

Lee, G.B.; Hong, Y.P.; Im, J.N.; Chung, K.W.

1989-01-01

This study was carried out to know the uptake pattern of phosphorous and potassium in rice plants using by two radioisotopes, 32P and 86Rb as tracers for two years, 1987 and 1988. Rice plants were grown in the hydroponic culture with Yoshida's solution, and treated with different temperatures, transpiration suppress, shading, and phosphorous and potassium deletions. The uptake amount of 32P and 86Rb were increased with the increasing temperature in root sphere of rice plant, particularly remarkable increase of 86Rb uptake at 35deg C. The uptake of 32P tended to be promoted at the treatment of low air-high water temperature (17-30deg C), while that of 86Rb was not significantly differenced from different temperature treatments. The effect of transpiration on the uptake of 32P and 86Rb was extremely low. This phenomenon may suggest that the absorption be depending on active uptake rather than passive one by transpiration stream. The total carbohydrate contents of rice root were decreased by shading treatment, resulting significant reduction in the uptake of 32P and 86Rb. The uptake of 86Rb was remarkably increased in the treatment of potassium deletion, but that of 32P was not significantly increased in the delection of phosphorous

Uptake of 32P and 86Rb as influenced by temperature, transpiration suppress and shading treatment in rice plants

Energy Technology Data Exchange (ETDEWEB)

Lee, G. B.; Hong, Y. P.; Im, J. N.; Chung, K. W.

1989-07-01

This study was carried out to know the uptake pattern of phosphorous and potassium in rice plants using by two radioisotopes, 32P and 86Rb as tracers for two years, 1987 and 1988. Rice plants were grown in the hydroponic culture with Yoshida's solution, and treated with different temperatures, transpiration suppress, shading, and phosphorous and potassium deletions. The uptake amount of 32P and 86Rb were increased with the increasing temperature in root sphere of rice plant, particularly remarkable increase of 86Rb uptake at 35deg C. The uptake of 32P tended to be promoted at the treatment of low air-high water temperature (17-30deg C), while that of 86Rb was not significantly differenced from different temperature treatments. The effect of transpiration on the uptake of 32P and 86Rb was extremely low. This phenomenon may suggest that the absorption be depending on active uptake rather than passive one by transpiration stream. The total carbohydrate contents of rice root were decreased by shading treatment, resulting significant reduction in the uptake of 32P and 86Rb. The uptake of 86Rb was remarkably increased in the treatment of potassium deletion, but that of 32P was not significantly increased in the delection of phosphorous.

Selenium essentials

CERN Document Server

Sams, Prashanth

2015-01-01

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

Selenium for preventing cancer

Directory of Open Access Journals (Sweden)

Gabriele Dennert

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

A Study on Pancreas Scanning with Selenium75-Selenomethionine

International Nuclear Information System (INIS)

Shin, Hyun Chan; Toh, Sang Hee; Ra, Woo Youn; Suh, Chul Sung

1968-01-01

Radiographic visualization of the pancreas is a difficult problem, but the direct visualization of the pancreas is possible by the injection of the amino-acid methionine tagged with selenium 75 (Se 75 ). In order to know the diagnostic value of pancreas scanning, scans were performed on 23 cases using selenium 75 -Selenomethionine. These cases were also given egg white, probanthine and morphine. 1) Good visualization of the pancreas scanning was observed on 19 cases, presumably with normal pancreas. 2) A case which showed diffusely decreased uptake on pancreas scanning was proven to have lesions in the bile duct and the gall bladder. 3) Of those two cases which showed localized cold area, one had pancreas cyst and the other one was not explored. 4) A case which showed no visualization of the pancreas was proven to have pancreatic carcinoma. 5) Two cases which showed widened duodenal loop by upper gastro-intestinal series revealed normal pancreas scanning, and no pancreatic disease was found in both cases.

Saponarin activates AMPK in a calcium-dependent manner and suppresses gluconeogenesis and increases glucose uptake via phosphorylation of CRTC2 and HDAC5.

Science.gov (United States)

Seo, Woo-Duck; Lee, Ji Hae; Jia, Yaoyao; Wu, Chunyan; Lee, Sung-Joon

2015-11-15

This study investigated the molecular mechanism of saponarin, a flavone glucoside, in the regulation of insulin sensitivity. Saponarin suppressed the rate of gluconeogenesis and increased cellular glucose uptake in HepG2 and TE671 cells by regulating AMPK. Using an in vitro kinase assay, we showed that saponarin did not directly interact with the AMPK protein. Instead, saponarin increased intracellular calcium levels and induced AMPK phosphorylation, which was diminished by co-stimulation with STO-609, an inhibitor of CAMKKβ. Transcription of hepatic gluconeogenesis genes was upregulated by nuclear translocation of CRTC2 and HDAC5, coactivators of CREB and FoxO1 transcription factors, respectively. This nuclear translocation was inhibited by increased phosphorylation of CRTC2 and HDAC5 by saponarin-induced AMPK in HepG2 cells and suppression of CREB and FoxO1 transactivation activities in cells stimulated by saponarin. The results from a chromatin immunoprecipitation assay confirmed the reduced binding of CRTC2 on the PEPCK and G6Pase promoters. In TE671 cells, AMPK phosphorylated HDAC5, which suppressed nuclear penetration and upregulated GLUT4 transcription, leading to enhanced glucose uptake. Collectively, these results suggest that saponarin activates AMPK in a calcium-dependent manner, thus regulating gluconeogenesis and glucose uptake. Copyright © 2015 Elsevier Ltd. All rights reserved.

Review on Nano SeleniumProduced by Bacteria

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LI Ji-xiang

2014-12-01

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

Why Nature Chose Selenium.

Science.gov (United States)

Reich, Hans J; Hondal, Robert J

2016-04-15

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

Arsenic-phosphorus interactions in the soil-plant-microbe system: Dynamics of uptake, suppression and toxicity to plants.

Science.gov (United States)

Anawar, Hossain M; Rengel, Zed; Damon, Paul; Tibbett, Mark

2018-02-01

High arsenic (As) concentrations in the soil, water and plant systems can pose a direct health risk to humans and ecosystems. Phosphate (Pi) ions strongly influence As availability in soil, its uptake and toxicity to plants. Better understanding of As(V)-Pi interactions in soils and plants will facilitate a potential remediation strategy for As contaminated soils, reducing As uptake by crop plants and toxicity to human populations via manipulation of soil Pi content. However, the As(V)-Pi interactions in soil-plant systems are complex, leading to contradictory findings among different studies. Therefore, this review investigates the role of soil type, soil properties, minerals, Pi levels in soil and plant, Pi transporters, mycorrhizal association and microbial activities on As-Pi interactions in soils and hydroponics, and uptake by plants, elucidate the key mechanisms, identify key knowledge gaps and recommend new research directions. Although Pi suppresses As uptake by plants in hydroponic systems, in soils it could either increase or decrease As availability and toxicity to plants depending on the soil types, properties and charge characteristics. In soil, As(V) availability is typically increased by the addition of Pi. At the root surface, the Pi transport system has high affinity for Pi over As(V). However, Pi concentration in plant influences the As transport from roots to shoots. Mycorrhizal association may reduce As uptake via a physiological shift to the mycorrhizal uptake pathway, which has a greater affinity for Pi over As(V) than the root epidermal uptake pathway. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-01

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

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

Science.gov (United States)

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

2015-07-01

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

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

Science.gov (United States)

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

2012-01-01

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

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

Directory of Open Access Journals (Sweden)

Ingibjorg Gunnarsdottir

2012-08-01

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

Microbial selenium sulfide reduction for selenium recovery from wastewater

NARCIS (Netherlands)

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

2017-01-01

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

Influence of Se concentrations and species in hydroponic cultures on Se uptake, translocation and assimilation in non-accumulator ryegrass.

Science.gov (United States)

Versini, Antoine; Di Tullo, Pamela; Aubry, Emmanuel; Bueno, Maïté; Thiry, Yves; Pannier, Florence; Castrec-Rouelle, Maryse

2016-11-01

The success of biofortification and phytoremediation practices, addressing Se deficiency and Se pollution issues, hinges crucially on the fate of selenium in the plant media in response to uptake, translocation and assimilation processes. We investigate the fate of selenium in root and shoot compartments after 3 and 6 weeks of experiment using a total of 128 plants grown in hydroponic solution supplied with 0.2, 2, 5, 20 and 100 mg L -1 of selenium in the form of selenite, selenate and a mixture of both species. Selenate-treated plants exhibited higher root-to-shoot Se translocation and total Se uptake than selenite-treated plants. Plants took advantage of the selenate mobility and presumably of the storage capacity of leaf vacuoles to circumvent selenium toxicity within the plant. Surprisingly, 28% of selenate was found in shoots of selenite-treated plants, questioning the ability of plants to oxidize selenite into selenate. Selenomethionine and methylated organo-selenium amounted to 30% and 8% respectively in shoots and 35% and 9% in roots of the identified Se, suggesting that selenium metabolization occurred concomitantly in root and shoot plant compartments and demonstrating that non-accumulator plants can synthesize notable quantities of precursor compound for volatilization. The present study demonstrated that non-accumulator plants can develop the same strategies as hyper-accumulator plants to limit selenium toxicity. When both selenate and selenite were supplied together, plants used selenate in a storage pathway and selenite in an assimilation pathway. Plants might thereby benefit from mixed supplies of selenite and selenate by saving enzymes and energy required for selenate reduction. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

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

International Nuclear Information System (INIS)

Zhang Jinsong; Wang Huali; Yu Hanqing

2007-01-01

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

Trace metal uptake by garden herbs and vegetables.

Science.gov (United States)

Shariatpanahi, M; Anderson, A C; Mather, F

1986-12-01

In many regions of Iran, crops are irrigated with municipal and industrial wastewater that contain a variety of metals. The purpose of this study was to simulate the level of metals that may be presented to plants over a growing season in a controlled laboratory setting. Cadmium, lead, arsenic, chromium, mercury, nickel, copper, zinc, and selenium were applied to plants at the high rate of 200 g metal/ha/wk. The following plants were examined for metal accumulation and effects on yield: garden cress (Lipidium sativum), leek (Allium porrum L.), basil (Ocimum basilicum L.), mint (Mentha arvensis L.), onion (Allium capa L.), radish (Raphanus sativus L.), and tarragon (Artemisia draculus L.). All plants showed significant uptake of all metals when compared to control (p=0.05), and growth was significantly reduced (p=0.05). Cadmium and chromium levels of 85±7.4 and 47.6±8.9 μg/g); selenium levels were highest in tarragon (16.5±5.8 μg/g). Zinc levels were similar (p=0.05) in all species tested, as were mercury and lead. The remaining metals (nickel and copper) showed significant differences in uptake, depending on plant species.

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-04-17

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

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

Science.gov (United States)

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

2012-01-01

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

Biological selenium removal from wastewaters

NARCIS (Netherlands)

Lenz, M.

2008-01-01

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

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

Directory of Open Access Journals (Sweden)

Zoran Pavlovic

2018-02-01

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

Selenium in diet

Science.gov (United States)

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

Variation of the distribution coefficient (Kd) of selenium in soils under various microbial states

International Nuclear Information System (INIS)

Fevrier, L.; Martin-Garin, A.; Leclerc, E.

2007-01-01

This study aimed to (i) evaluate whether the K d value of selenium is dependent upon the soil microbial activity and (ii) define the limitation of the use of the K d concept to describe selenium behaviour in soils when assessing the long-term radiological waste disposal risk. K d coefficients, as well as information on selenite speciation in the soil-solution, were derived from short- and long-term batch experiments with a calcareous silty clay soil in various microbial states. Soil microbial activity induced (i) an increase of the K d value from 16 l kg -1 in sterile conditions to 130 l kg -1 when the soil was amended with glucose and nitrate, and (ii) changes in selenium speciation both in the solution (presence of seleno-species other than free Se(IV)) and in the solid phase (Se linked to microorganisms). Although the K d coefficient adequately reflects the initial fractionation between soil-solid and soil-solution, it does not allow for speciation and microbial processes, which could affect reversibility, mobility and the long-term accumulation and uptake into crops

Long-term selenium status in humans

International Nuclear Information System (INIS)

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

2001-01-01

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

Mechanism of Selenium Loss in Copper Slag

Science.gov (United States)

Desai, Bhavin; Tathavadkar, Vilas; Basu, Somnath

2018-03-01

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

Mechanism of Selenium Loss in Copper Slag

Science.gov (United States)

Desai, Bhavin; Tathavadkar, Vilas; Basu, Somnath

2018-06-01

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

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

Science.gov (United States)

Nicastro, Holly L.; Dunn, Barbara K.

2013-01-01

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

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

Directory of Open Access Journals (Sweden)

Holly L. Nicastro

2013-04-01

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

Selenium for preventing cancer.

Science.gov (United States)

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

2018-01-29

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

Selenium in human mammary carcinogenesis

DEFF Research Database (Denmark)

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

1991-01-01

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

Selenium in food and health

National Research Council Canada - National Science Library

Reilly, Conor

2006-01-01

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Selective uptake measurements of thyroid nodules with 132I before and after pituitary suppression with T4 and T3, comparison with the TRH assay

International Nuclear Information System (INIS)

Eitenmueller, K.

1977-01-01

75 patients with suspected hormone-producing autonomous adenoma were examined by the extended TRH assay (BTSH determination, TSH rise 30 min. p.i., and T3 rise 120 min. p.i. 400 μg TRH i.v.) and selective uptake measurements of three different areas of the thyroid using 132 I. The TRH stimulation test alone or the 132 I uptake test alone before and after suppression do not give a clear diagnosis. A clear differentiation of thyroid diseases is only possible if both tests are applied and their results combined. For a differential diagnosis of nodular hyperthyroidism resp. autonomous adenoma, also the TSH stimulation test is necessary in addition to the combination of TRH test and suppression test. (orig./AJ) [de

Selenium for preventing cancer

Science.gov (United States)

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

2015-01-01

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

21 CFR 573.920 - Selenium.

Science.gov (United States)

2010-04-01

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

Dietary selenium in the Glasgow area

International Nuclear Information System (INIS)

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

1978-01-01

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

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

Science.gov (United States)

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

2016-01-01

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

Aquatic Life Criterion - Selenium

Science.gov (United States)

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

A Study on Pancreas Scanning with Selenium{sup 75}-Selenomethionine

Energy Technology Data Exchange (ETDEWEB)

Shin, Hyun Chan; Toh, Sang Hee; Ra, Woo Youn; Suh, Chul Sung [Presbyterian Hospital, Deagu (Korea, Republic of)

1968-03-15

Radiographic visualization of the pancreas is a difficult problem, but the direct visualization of the pancreas is possible by the injection of the amino-acid methionine tagged with selenium{sup 75} (Se{sup 75}). In order to know the diagnostic value of pancreas scanning, scans were performed on 23 cases using selenium{sup 75}-Selenomethionine. These cases were also given egg white, probanthine and morphine. 1) Good visualization of the pancreas scanning was observed on 19 cases, presumably with normal pancreas. 2) A case which showed diffusely decreased uptake on pancreas scanning was proven to have lesions in the bile duct and the gall bladder. 3) Of those two cases which showed localized cold area, one had pancreas cyst and the other one was not explored. 4) A case which showed no visualization of the pancreas was proven to have pancreatic carcinoma. 5) Two cases which showed widened duodenal loop by upper gastro-intestinal series revealed normal pancreas scanning, and no pancreatic disease was found in both cases.

Chemical form of selenium affects its uptake, transport, and glutathione peroxidase activity in the human intestinal Caco-2 cell model.

Science.gov (United States)

Zeng, Huawei; Jackson, Matthew I; Cheng, Wen-Hsing; Combs, Gerald F

2011-11-01

Determining the effect of selenium (Se) chemical form on uptake, transport, and glutathione peroxidase activity in human intestinal cells is critical to assess Se bioavailability at nutritional doses. In this study, we found that two sources of L-selenomethionine (SeMet) and Se-enriched yeast each increased intracellular Se content more effectively than selenite or methylselenocysteine (SeMSC) in the human intestinal Caco-2 cell model. Interestingly, SeMSC, SeMet, and digested Se-enriched yeast were transported at comparable efficacy from the apical to basolateral sides, each being about 3-fold that of selenite. In addition, these forms of Se, whether before or after traversing from apical side to basolateral side, did not change the potential to support glutathione peroxidase (GPx) activity. Although selenoprotein P has been postulated to be a key Se transport protein, its intracellular expression did not differ when selenite, SeMSC, SeMet, or digested Se-enriched yeast was added to serum-contained media. Taken together, our data show, for the first time, that the chemical form of Se at nutritional doses can affect the absorptive (apical to basolateral side) efficacy and retention of Se by intestinal cells; but that, these effects are not directly correlated to the potential to support GPx activity.

Selenium in Graves' disease

Directory of Open Access Journals (Sweden)

Jadwiga Kryczyk

2013-05-01

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

The effect of catch crop species on selenium availability for succeeding crops

DEFF Research Database (Denmark)

Stavridou, Eleftheria; Young, Scott D.; Thorup-Kristensen, Kristian

2012-01-01

2007–10 investigated the ability of catch crops (Italian ryegrass, fodder radish and hairy vetch) under different fertiliser regimes to reduce soil Se content in the autumn and to increase its availability in spring to the succeeding crop. Results and Conclusions The catch crops (Italian ryegrass...... and fodder radish) increased water-extractable Se content in the 0.25–0.75msoil layer in only one of the experiments. Selenium uptake by the catch crops varied between 65 and 3263 mg ha−1, depending on species, year and fertilisation treatment; this corresponded to 0.1–3.0% of the water-extractable soil Se......Background and Aims Selenium (Se) is an essential nutrient for humans and animals. In order to ensure an optimal concentration of Se in crops, Se fertilisers are applied. Catch crops may be an alternative way to increase Se concentrations in vegetables. Methods Three experiments in Denmark between...

Does selenium supplementation affect thyroid function?

DEFF Research Database (Denmark)

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

2015-01-01

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

Acute selenium poisoning in lambs

Energy Technology Data Exchange (ETDEWEB)

Gabbedy, B J; Dickson, J

1969-10-01

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

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

Science.gov (United States)

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

2007-01-01

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

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

Science.gov (United States)

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

2009-01-01

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

The Cultivation and SeleniumEnrichment of SeleniumEnriched Earthworm

Directory of Open Access Journals (Sweden)

SUN Xiao-fei

2014-12-01

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

Trace Element Analysis of Selenium

International Nuclear Information System (INIS)

Soliman, M.S.A.

2010-01-01

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

Acute selenium poisoning in cattle

Energy Technology Data Exchange (ETDEWEB)

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

1971-01-01

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

In vitro uptake of 75Se-selenite by lens of young and adult rats

International Nuclear Information System (INIS)

Sladkova, J.; Ostadalova, I.; Babicky, A.; Obenberger, J.

1988-01-01

The uptake was observed of 75 Se-selenite by the lens in Wistar strain rats in adult animals, in 17-day old rats kept with their mothers and in prematurely weaned rats. Also measured was the excretion of 75 Se by the lens of young and adult rats following incubation in the medium with radioselenium. The metabolites were analysed which were discharged by the lens containing 75 Se. In Brattleboro rats the uptake of 75 Se-selenite was also measured by the lens in young and adult rats. The uptake of 75 Se-selenite by the lens in young Wistar rats was found to be 1.6 times higher than by the lens of adult rats and the time course of the radioselenium uptake was slightly different. In the lens of prematurely weaned rats no significant difference was found in the uptake of radioselenium after 4 hours as compared with rats of the same age kept with their mothers. In homozygous Brattleboro rats, a higher uptake of 75 Se-selenite was found as compared with both young and adult heterozygous rats. The time course and the quantity of 75 Se efflux from the lens of young and adult Wistar rats differed significantly after 0.5 hour of pre-incubation. From metabolites containing 75 Se excreted by the lens following preincubation, glutathione selenotrisulfide and a not yet accurately determined fraction with a large share of radioactivity were isolated. The stated results provide yet more proof that selenium cataract is a manifestation of the ontogenic dependence of selenium metabolism in the lens and in the entire organism. (author). 4 tabs., 30 refs

Selenistasis: Epistatic Effects of Selenium on Cardiovascular Phenotype

Directory of Open Access Journals (Sweden)

Joseph Loscalzo

2013-01-01

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

Murine remote preconditioning increases glucose uptake and suppresses gluconeogenesis in hepatocytes via a brain-liver neurocircuit, leading to counteracting glucose intolerance.

Science.gov (United States)

Kurabayashi, Atsushi; Tanaka, Chiharu; Matsumoto, Waka; Naganuma, Seiji; Furihata, Mutsuo; Inoue, Keiji; Kakinuma, Yoshihiko

2018-05-01

Our previous study revealed that cyclic hindlimb ischaemia-reperfusion (IR) activates cardiac acetylcholine (ACh) synthesis through the cholinergic nervous system and cell-derived ACh accelerates glucose uptake. However, the mechanisms regulating glucose metabolism in vivo remain unknown. We investigated the effects and mechanisms of IR in mice under pathophysiological conditions. Using IR-subjected male C57BL/6J mice, the effects of IR on blood sugar (BS), glucose uptake, central parasympathetic nervous system (PNS) activity, hepatic gluconeogenic enzyme expression and those of ACh on hepatocellular glucose uptake were assessed. IR decreased BS levels by 20% and increased c-fos immunoreactivity in the center of the PNS (the solitary tract and the dorsal motor vagal nucleus). IR specifically downregulated hepatic gluconeogenic enzyme expression and activities (glucose-6-phosphatase and phosphoenolpyruvate carboxykinase) and accelerated hepatic glucose uptake. Transection of a hepatic vagus nerve branch decreased this uptake and reversed BS decrease. Suppressed gluconeogenic enzyme expression was reversed by intra-cerebroventricular administration of a choline acetyltransferase inhibitor. Moreover, IR significantly attenuated hyperglycaemia in murine model of type I and II diabetes mellitus. IR provides another insight into a therapeutic modality for diabetes mellitus due to regulating gluconeogenesis and glucose-uptake and advocates an adjunctive mode rectifying disturbed glucose metabolism. Copyright © 2018 Elsevier B.V. All rights reserved.

A proteomic analysis of green and white sturgeon larvae exposed to heat stress and selenium

Science.gov (United States)

Silvestre, Frédéric; Linares-Casenave, Javier; Doroshov, Serge I.; Kültz, Dietmar

2012-01-01

Temperature and selenium are two environmental parameters that potentially affect reproduction and stock recruitment of sturgeon in the San Francisco Bay / Delta Estuary. To identify proteins whose expression is modified by these environmental stressors, we performed a proteomic analysis on larval green and white sturgeons exposed to 18 or 26°C and micro-injected with Seleno-L-Methionine to reach 8 μg g-1 selenium body burden, with L-Methionine as a control. Selenium and high temperature induced mortalities and abnormal morphologies in both species, with a higher mortality in green sturgeon. Larval proteins were separated by two-dimensional gel electrophoresis and differential abundances were detected following spot quantitation and hierarchical cluster analysis. In green sturgeon, 34 of 551 protein spots detected on gels showed a variation in abundance whereas in white sturgeon only 9 of 580 protein spots were differentially expressed (P<0.01). Gel replicates were first grouped according to heat treatment. Fifteen of these spots were identified using MALDI TOF/TOF mass spectrometry. Proteins involved in protein folding, protein synthesis, protein degradation, ATP supply and structural proteins changed in abundance in response to heat and/or selenium. 40S ribosomal protein SA, FK506-binding protein 10, 65 kDa regulatory subunit A of protein phosphatase 2, protein disulfide isomerase, stress-induced-phosphoprotein 1, suppression of tumorigenicity 13 and collagen type II alpha 1, were differentially expressed in high temperature treatment only. Serine/arginine repetitive matrix protein 1, creatine kinase, serine peptidase inhibitor Kazal type 5 and HSP90 were sensitive to combined temperature and selenium exposure. Valosin-containing protein, a protein involved in aggresome formation and in protein quality control decreased more than 50% in response to selenium treatment. Potential use of such proteins as biomarkers of environmental stressors in larval sturgeons

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

Science.gov (United States)

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

2009-01-01

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

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

Science.gov (United States)

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

2008-01-01

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

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

Science.gov (United States)

2014-01-01

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

Joint refinery selenium treatability study

International Nuclear Information System (INIS)

Meyer, C.L.; Folwarkow, S.

1993-01-01

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

Selenium content of foods purchased or produced in Ohio.

Science.gov (United States)

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

1987-06-01

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

Recovery of stream communities from experimental selenium exposure

Energy Technology Data Exchange (ETDEWEB)

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

1994-12-31

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

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

Science.gov (United States)

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

2015-05-01

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

Distribution and mode of occurrence of selenium in US coals

Science.gov (United States)

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

1993-01-01

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

The relationship between selenium and gastric cancer

International Nuclear Information System (INIS)

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

1993-01-01

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

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

Science.gov (United States)

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

Selenium plating of aluminium and nickel surfaces

International Nuclear Information System (INIS)

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

1993-01-01

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

Is selenium supplementation in autoimmune thyroid diseases justified?

Science.gov (United States)

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

2017-10-01

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

Selenium Sequestration in a Cationic Layered Rare Earth Hydroxide: A Combined Batch Experiments and EXAFS Investigation.

Science.gov (United States)

Zhu, Lin; Zhang, Linjuan; Li, Jie; Zhang, Duo; Chen, Lanhua; Sheng, Daopeng; Yang, Shitong; Xiao, Chengliang; Wang, Jianqiang; Chai, Zhifang; Albrecht-Schmitt, Thomas E; Wang, Shuao

2017-08-01

Selenium is of great concern owing to its acutely toxic characteristic at elevated dosage and the long-term radiotoxicity of 79 Se. The contents of selenium in industrial wastewater, agricultural runoff, and drinking water have to be constrained to a value of 50 μg/L as the maximum concentration limit. We reported here the selenium uptake using a structurally well-defined cationic layered rare earth hydroxide, Y 2 (OH) 5 Cl·1.5H 2 O. The sorption kinetics, isotherms, selectivity, and desorption of selenite and selenate on Y 2 (OH) 5 Cl·1.5H 2 O at pH 7 and 8.5 were systematically investigated using a batch method. The maximum sorption capacities of selenite and selenate are 207 and 124 mg/g, respectively, both representing the new records among those of inorganic sorbents. In the low concentration region, Y 2 (OH) 5 Cl·1.5H 2 O is able to almost completely remove selenium from aqueous solution even in the presence of competitive anions such as NO 3 - , Cl - , CO 3 2- , SO 4 2- , and HPO 4 2- . The resulting concentration of selenium is below 10 μg/L, well meeting the strictest criterion for the drinking water. The selenate on loaded samples could be desorbed by rinsing with concentrated noncomplexing NaCl solutions whereas complexing ligands have to be employed to elute selenite for the material regeneration. After desorption, Y 2 (OH) 5 Cl·1.5H 2 O could be reused to remove selenate and selenite. In addition, the sorption mechanism was unraveled by the combination of EDS, FT-IR, Raman, PXRD, and EXAFS techniques. Specifically, the selenate ions were exchanged with chloride ions in the interlayer space, forming outer-sphere complexes. In comparison, besides anion exchange mechanism, the selenite ions were directly bound to the Y 3+ center in the positively charged layer of [Y 2 (OH) 5 (H 2 O)] + through strong bidentate binuclear inner-sphere complexation, consistent with the observation of the higher uptake of selenite over selenate. The results presented in

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

OpenAIRE

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

2012-01-01

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

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

OpenAIRE

Azadeh SAFFARYAZDI; Mehrdad LAHOUTI; Ali GANJEALI; Hassan BAYAT

2012-01-01

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

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

Science.gov (United States)

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

2017-09-01

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

Influence of selenite and selenate supplementation on the chromium uptake and translocation in Allium cepa

International Nuclear Information System (INIS)

Karuna Shanker; Setia, Seema; Srivastava, Shalini; Dass, Sahab; Srivastava, Rohit; Satya Prakash; Srivastava, M.M.

1997-01-01

Pot experiments were conducted on onion plant to study the effects of selenite and selenate treatments (0.5-6.0) μg ml -1 on the uptake and translocation of root absorbed chromium irrigated with 2 and 5 μg ml -1 of chromium in sand and soil. Both the form of selenium (SeO 3 2- , and SeO 4 2- ) were found equally effective in reducing the chromium burden of the plant. No significant difference (p>0.05) in dry matter yields among various selenium treatments exist suggesting no salt injury occurred in the plants under prevailing conditions. (author). 10 refs., 1 tab

Absorption and retention of selenium from shrimps in man

DEFF Research Database (Denmark)

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

2001-01-01

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

Arsenic and selenium in microbial metabolism

Science.gov (United States)

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

2006-01-01

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

Selenium Level and Dyslipidemia in Rural Elderly Chinese

Science.gov (United States)

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

2015-01-01

Objective Higher selenium level has been hypothesized to have the potential to reduce the risk of cardiovascular diseases including dyslipidemia. However, results from previous studies are inconsistent. This study aims to determine the association between selenium level and dyslipidemia in elderly Chinese with relatively low selenium status. Methods A cross-sectional study of 1859 participants aged 65 or older from four rural counties in China was conducted. Serum total cholesterol (TC), triglycerides (TG), high density lipoprotein-cholesterol (HDLC) and low-density lipoprotein-cholesterol (LDLC), nail selenium concentration and APOE genotype were measured in all subjects. The four types of dyslipidemia were defined as >5.17mmol/L for High-TC, >1.69 mmol/L for High-TG, >3.36 mmol/L for High-LDLC, and selenium levels and the risk of dyslipidemia. Results Mean nail selenium concentration was 0.465μg/gin this sample. Rates for High-TC, High-LDLC, High-TG, Low-HDLC were 18.13%, 13.23%, 12.21% and 32.76% respectively. Results from logistic models indicated that higher selenium levels were significantly associated with higher risk of High-TC, High-LDLC and lower risk of Low-HDLC adjusting for covariates (p selenium quartile group, participants in selenium quartile groups 2, 3 and 4 had significantly higher rates of High-TC, High-LDLC, High-TG, and lower rate of Low-HDLC adjusting for covariates. No significant association was observed between selenium level and the risk of High-TG. APOEε4 carriers had higher rates of High-TC and High-LDLC. There was no interaction between selenium level and APOE with the rates of dyslipidemia. Conclusions Our results suggest long-term selenium exposure level may be associated with the risk of dyslipidemia in elderly population. Future studies are needed to examine the underlying mechanism of the association. PMID:26380972

Selenium in human milk: An Australian study

International Nuclear Information System (INIS)

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

1991-01-01

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

Is selenium supplementation in autoimmune thyroid diseases justified?

DEFF Research Database (Denmark)

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

2017-01-01

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

Determination of total selenium and selenium distribution in the milk phases in commercial cow's milk by HG-AAS

Energy Technology Data Exchange (ETDEWEB)

Muniz-Naveiro, Oscar; Dominguez-Gonzalez, Raquel; Bermejo-Barrera, Adela; Bermejo-Barrera, Pilar [University of Santiago de Compostela, Department of Analytical Chemistry, Nutrition and Bromatology, Santiago de Compostela (Spain); Cocho, Jose A. [University Clinical Hospital, Laboratory of Metabolic and Nutritional Disorders, Santiago de Compostela (Spain); Fraga, Jose M. [University Clinical Hospital, Department of Pediatrics, Santiago de Compostela (Spain)

2005-03-01

A procedure has been developed for determining the selenium in cow's milk using hydride generation-atomic absorption spectrometry (HG-AAS) following microwave-assisted acid digestion. The selenium distributions in milk whey, fat and micellar casein phases were studied after separating the different phases by ultracentrifugation and determining the selenium in all of them. The detection limits obtained by HG-AAS for the whole milk, milk whey and micellar casein were 0.074, 0.065 and 0.075 {mu}g l{sup -1}, respectively. The accuracy for the whole milk was checked by using a Certified Reference Material CRM 8435 whole milk powder from NIST, and the analytical recoveries for the milk whey and casein micelles were 100.9 and 96.9%, respectively. A mass balance study of the determination of selenium in the different milk phases was carried out, obtaining values of 95.5-100.8%. The total content of selenium was determined in 37 milk samples from 15 different manufacturers, 19 whole milk samples and 18 skimmed milk samples. The selenium levels found were within the 8.5-21 {mu}g l{sup -1} range. The selenium distributions in the different milk phases were studied in 14 whole milk samples, and the highest selenium levels were found in milk whey (47.2-73.6%), while the lowest level was found for the fat phase (4.8-16.2%). A strong correlation was found between the selenium levels in whole milk and the selenium levels in the milk components. (orig.)

Determinants of selenium in the toenail biomonitor

International Nuclear Information System (INIS)

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

2006-01-01

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

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

NARCIS (Netherlands)

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

2012-01-01

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

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

Science.gov (United States)

Zhao, Changhui; Zeng, Huawei; Wu, Ryan T Y; Cheng, Wen-Hsing

2016-01-01

Selenium-binding protein 1 (SBP1) is not a selenoprotein but structurally binds selenium. Loss of SBP1 during carcinogenesis usually predicts poor prognosis. Because genome instability is a hallmark of cancer, we hypothesize that SBP1 sequesters cellular selenium and sensitizes cancer cells to DNA-damaging agents. To test this hypothesis, we knocked down SBP1 expression in HeLa cervical cancer cells by employing a short hairpin RNA (shRNA) approach. Reduced sensitivity to hydrogen peroxide, paraquat and camptothecin, reactive oxygen species content, and intracellular retention of selenium after selenomethionine treatment were observed in SBP1 shRNA HeLa cells. Results from Western analyses showed that treatment of HeLa cells with selenomethionine resulted in increased SBP1 protein expression in a dose-dependent manner. Knockdown of SBP1 rendered HeLa cells increased expression of glutathione peroxidase-1 but not glutathione peroxidase-4 protein levels and accelerated migration from a wound. Altogether, SBP1 retains supplemental selenium and sensitizes HeLa cancer cells to clastogens, suggesting a new cancer treatment strategy by sequestering selenium through SBP1.

[The role of selenium in endocrine system diseases].

Science.gov (United States)

Balázs, Csaba; Rácz, Károly

2013-10-13

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

Effects of selenium supplementation on four agricultural crops.

Science.gov (United States)

Carvalho, Kathleen M; Gallardo-Williams, Maria T; Benson, Robert F; Martin, Dean F

2003-01-29

Agricultural crops can be used either to remediate selenium-contaminated soils or to increase the daily selenium intake of consumers after soil supplementation using inorganic or organic selenium sources. In this study, four agricultural crops were examined for potential selenium enhancement. Soils containing tomato, strawberry, radish, and lettuce plants were supplemented with either an inorganic or an organic form of selenium. Two different soils, i.e., low Se and high Se containing, were also used. Statistically significant differences in appearance, fruit production, and fresh weights of the fruit produced were studied. Next, the amount of selenium retained in the edible fruits, nonedible plant, and soil for each was analyzed by acid digestion followed by hydride generation atomic absorption analysis. Finally, inhibition effects on the seeds of the agricultural plants were studied. The results show that supplementation with an inorganic form of selenium led to higher retention in the plants, with a maximum of 97.5% retained in the edible portion of lettuce plants.

Does mercury vapor exposure increase urinary selenium excretion

Energy Technology Data Exchange (ETDEWEB)

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

1985-01-01

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

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

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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

Selenium nanoparticles: potential in cancer gene and drug delivery.

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Maiyo, Fiona; Singh, Moganavelli

2017-05-01

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

Preliminary Study on the Standard of Selenium Content in Agricultural Products

Institute of Scientific and Technical Information of China (English)

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

2012-01-01

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

Selenium deficiency and the effects of supplementation on preterm infants

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Renata Germano B. O. N. Freitas

2014-03-01

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

Selenium accumulation in lettuce germplasm

Science.gov (United States)

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

SELENIUM ACCUMULATION BY BASIL PLANTS (OCINUM BASILICUM L.

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N. A. Golubkina

2014-01-01

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

A Study of Selenium in Leprosy

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Donna Partogi

2018-03-01

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

Selenium's importance in regulatory issues regarding mercury

Energy Technology Data Exchange (ETDEWEB)

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

2009-11-15

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

[Pharmaconutrition with parenteral selenium in sepsis].

Science.gov (United States)

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

2014-04-01

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

Selecting Lentil Accessions for Global Selenium Biofortification

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Dil Thavarajah

2017-08-01

Full Text Available The biofortification of lentil (Lens culinaris Medikus. has the potential to provide adequate daily selenium (Se to human diets. The objectives of this study were to (1 determine how low-dose Se fertilizer application at germination affects seedling biomass, antioxidant activity, and Se uptake of 26 cultivated lentil genotypes; and (2 quantify the seed Se concentration of 191 lentil wild accessions grown in Terbol, Lebanon. A germination study was conducted with two Se treatments [0 (control and 30 kg of Se/ha] with three replicates. A separate field study was conducted in Lebanon for wild accessions without Se fertilizer. Among cultivated lentil accessions, PI533690 and PI533693 showed >100% biomass increase vs. controls. Se addition significantly increased seedling Se uptake, with the greatest uptake (6.2 µg g−1 by PI320937 and the least uptake (1.1 µg g−1 by W627780. Seed Se concentrations of wild accessions ranged from 0 to 2.5 µg g−1; accessions originating from Syria (0–2.5 µg g−1 and Turkey (0–2.4 µg g−1 had the highest seed Se. Frequency distribution analysis revealed that seed Se for 63% of accessions was between 0.25 and 0.75 µg g−1, and thus a single 50 g serving of lentil has the potential to provide adequate dietary Se (20–60% of daily recommended daily allowance. As such, Se application during plant growth for certain lentil genotypes grown in low Se soils may be a sustainable Se biofortification solution to increase seed Se concentration. Incorporating a diverse panel of lentil wild germplasm into Se biofortification programs will increase genetic diversity for effective genetic mapping for increased lentil seed Se nutrition and plant productivity.

Selecting Lentil Accessions for Global Selenium Biofortification.

Science.gov (United States)

Thavarajah, Dil; Abare, Alex; Mapa, Indika; Coyne, Clarice J; Thavarajah, Pushparajah; Kumar, Shiv

2017-08-26

The biofortification of lentil ( Lens culinaris Medikus.) has the potential to provide adequate daily selenium (Se) to human diets. The objectives of this study were to (1) determine how low-dose Se fertilizer application at germination affects seedling biomass, antioxidant activity, and Se uptake of 26 cultivated lentil genotypes; and (2) quantify the seed Se concentration of 191 lentil wild accessions grown in Terbol, Lebanon. A germination study was conducted with two Se treatments [0 (control) and 30 kg of Se/ha] with three replicates. A separate field study was conducted in Lebanon for wild accessions without Se fertilizer. Among cultivated lentil accessions, PI533690 and PI533693 showed >100% biomass increase vs. Se addition significantly increased seedling Se uptake, with the greatest uptake (6.2 µg g -1 ) by PI320937 and the least uptake (1.1 µg g -1 ) by W627780. Seed Se concentrations of wild accessions ranged from 0 to 2.5 µg g -1 ; accessions originating from Syria (0-2.5 µg g -1 ) and Turkey (0-2.4 µg g -1 ) had the highest seed Se. Frequency distribution analysis revealed that seed Se for 63% of accessions was between 0.25 and 0.75 µg g -1 , and thus a single 50 g serving of lentil has the potential to provide adequate dietary Se (20-60% of daily recommended daily allowance). As such, Se application during plant growth for certain lentil genotypes grown in low Se soils may be a sustainable Se biofortification solution to increase seed Se concentration. Incorporating a diverse panel of lentil wild germplasm into Se biofortification programs will increase genetic diversity for effective genetic mapping for increased lentil seed Se nutrition and plant productivity.

Effect of long-term selenium supplementation on mortality

DEFF Research Database (Denmark)

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

2018-01-01

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

Biogeochemical studies of selenium in the Indian Ocean

International Nuclear Information System (INIS)

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

1999-01-01

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

Production of selenium-enriched milk and dairy products

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Csapó J.

2015-01-01

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

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

Science.gov (United States)

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

2017-03-04

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

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

Science.gov (United States)

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

2013-01-01

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

Selenium: its potential role in male infertility

International Nuclear Information System (INIS)

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

2009-01-01

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

Selenium Level and Dyslipidemia in Rural Elderly Chinese.

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Liqin Su

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

Selenium supplementation for critically ill adults

DEFF Research Database (Denmark)

Allingstrup, Mikkel; Afshari, Arash

2015-01-01

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

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

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Azadeh SAFFARYAZDI

2012-11-01

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

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

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Azadeh SAFFARYAZDI

2012-11-01

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

The role of selenium in predicting preeclampsia

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Z Ghaemi

2013-10-01

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

Genome-wide association study of serum selenium concentrations

DEFF Research Database (Denmark)

Gong, Jian; Hsu, Li; Harrison, Tabitha

2013-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Selenium Nanoparticles for Stress-Resilient Fish and Livestock

Science.gov (United States)

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

2015-09-01

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

Substoichiometric determination of selenium with potassium ethyl xanthate

International Nuclear Information System (INIS)

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

1989-01-01

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

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

Science.gov (United States)

Dhere, Neelkanth G.; Kadam, Ankur A.

2009-12-15

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

Determination of human and Sprague-Dawley rat trimethylseleonium ion and total selenium urine concentrations from endogenous body selenium pool by neutron activation analysis

International Nuclear Information System (INIS)

Blotcky, A.J.; Claassen, J.P.; Rack, E.P.

1992-01-01

This study determined trimethylselenonium ion [TMSe,(CH 3 ) 3 Se + ] and total organic selenium cationic species urinary excretion values for healthy human subjects and Sprague-Dawley rats fed regular diets. The only source of TMSe was from the endogenous selenium body pool. Total selenium concentration in urine was determined by instrumental neutron activation analysis. TMSe and total selenium cationic species concentrations and percent of total selenium urine excretion were determined by chemical neutron activation analysis and coupled anion-cation exchange chromatography and anion-exchange chromatography, respectively. Within experimental error, mean values for TMSe and cationic species as percent selenium were comparable for both human subjects and Sprague-Dawley rats. This study suggested that TMSe excreated in urine by healthy human subjects and Sprague-Dawley rats fed a normal diet is not a minor but a general metabolite of selenium ingested in a normal diet. (author) 27 refs.; 1 fig.; 2 tabs

Selenium accumulation by plants

Science.gov (United States)

White, Philip J.

2016-01-01

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

NAIL KERATIN AS MONITOR-TISSUE FOR SELENIUM EXPOSURE

NARCIS (Netherlands)

VANNOORD, PAH; MAAS, MJ; DEBRUIN, M

1992-01-01

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

Lignosulfonate-stabilized selenium nanoparticles and their deposition on spherical silica.

Science.gov (United States)

Modrzejewska-Sikorska, Anna; Konował, Emilia; Klapiszewski, Łukasz; Nowaczyk, Grzegorz; Jurga, Stefan; Jesionowski, Teofil; Milczarek, Grzegorz

2017-10-01

We report a novel room-temperature synthesis of selenium nanoparticles, which for the first time uses lignosulfonate as a stabilizer. Various lignosulfonates obtained both from hardwood and softwood were tested. Selenium oxide was used as the precursor of zero-valent selenium. Three different reducers were tested - sodium borohydride, hydrazine and ascorbic acid - and the latter proved most effective in terms of the particle size and stability of the final colloid. The lignosulfonate-stabilized selenium nanoparticles had a negative zeta potential, dependent on pH, which for some lignosulfonates reached -50mV, indicating the excellent stability of the colloid. When spherical silica particles were introduced to the synthesis mixture, selenium nanoparticles were deposited on their surface. Additionally, star-like structures consisting of sharp selenium needles with silica cores were observed. After drying, the selenium-functionalized silica had a grey metallic hue. The method reported here is simple and cost-effective, and can be used for the preparation of large quantities of selenium colloids or the surface modification of other materials with selenium. Copyright © 2017 Elsevier B.V. All rights reserved.

Reproduction in eastern screech-owls fed selenium

Science.gov (United States)

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

1996-01-01

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

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

Science.gov (United States)

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

2017-10-23

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

Advanced prostate cancer risk in relation to toenail selenium levels

NARCIS (Netherlands)

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

2013-01-01

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

Bio-induced solid selenium for recovery from water

NARCIS (Netherlands)

Hageman, S.P.W.

2015-01-01

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

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Investigation of electrical noise in selenium-immersed thermistor bolometers

Science.gov (United States)

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

1980-01-01

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

Selenium inhibits the phytotoxicity of mercury in garlic (Allium sativum)

International Nuclear Information System (INIS)

Zhao, Jiating; Gao, Yuxi; Li, Yu-Feng; Hu, Yi; Peng, Xiaomin; Dong, Yuanxing; Li, Bai; Chen, Chunying; Chai, Zhifang

2013-01-01

To investigate the influence of selenium on mercury phytotoxicity, the levels of selenium and mercury were analyzed with inductively coupled plasma-mass spectrometry (ICP-MS) in garlic tissues upon exposure to different dosages of inorganic mercury (Hg 2+ ) and selenite (SeO 3 2− ) or selenate (SeO 4 2− ). The distributions of selenium and mercury were examined with micro-synchrotron radiation X-ray fluorescence (μ-SRXRF), and the mercury speciation was investigated with micro-X-ray absorption near edge structure (μ-XANES). The results show that Se at higher exposure levels (>1 mg/L of SeO 3 2− or SeO 4 2− ) would significantly inhibit the absorption and transportation of Hg when Hg 2+ levels are higher than 1 mg/L in culture media. SeO 3 2− and SeO 4 2− were found to be equally effective in reducing Hg accumulation in garlic. The inhibition of Hg uptake by Se correlates well with the influence of Se on Hg phytotoxicity as indicated by the growth inhibition factor. Elemental imaging using μ-SRXRF also shows that Se could inhibit the accumulation and translocation of Hg in garlic. μ-XANES analysis shows that Hg is mainly present in the forms of Hg–S bonding as Hg(GSH) 2 and Hg(Met) 2 . Se exposure elicited decrease of Hg–S bonding in the form of Hg(GSH) 2 , together with Se-mediated alteration of Hg absorption, transportation and accumulation, may account for attenuated Hg phytotoxicity by Se in garlic. -- Highlights: ► Hg phytotoxicity can be mitigated by Se supplement in garlic growth. ► Se can inhibit the accumulation and transportation of Hg in garlic tissues. ► Localization and speciation of Hg in garlic can be modified by Se

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

Science.gov (United States)

Alexander, Jan; Aaseth, Jan

2016-01-01

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

Understanding selenium biogeochemistry in engineered ecosystems

NARCIS (Netherlands)

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

2017-01-01

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

Effects of Interaction between Cadmium (Cd) and Selenium (Se) on Grain Yield and Cd and Se Accumulation in a Hybrid Rice (Oryza sativa) System.

Science.gov (United States)

Huang, Baifei; Xin, Junliang; Dai, Hongwen; Zhou, Wenjing

2017-11-01

A pot experiment was conducted to investigate the interactive effects of cadmium (Cd) and selenium (Se) on their accumulation in three rice cultivars, which remains unclear. The results showed that Se reduced Cd-induced growth inhibition, and increased and decreased Se and Cd concentrations in brown rice, respectively. Cadmium concentrations in all tissues of the hybrid were similar to those in its male parent yet significantly lower than those in its female parent. Selenium reduced Cd accumulation in rice when Cd concentration exceeded 2.0 mg kg -1 ; however Se accumulation depended on the levels of Cd exposure. Finally, Cd had minimal effect on Se translocation within the three cultivars. We concluded that Cd concentration in brown rice is a heritable trait, making crossbreeding a feasible method for cultivating high-yield, low-Cd rice cultivars. Selenium effectively decreased the toxicity and accumulation of Cd, and Cd affected Se uptake but not translocation.

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

Directory of Open Access Journals (Sweden)

Carina Benstoem

2015-04-01

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

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

Science.gov (United States)

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

2015-01-01

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

Biological effects of selenium and relationships with carcinogenesis

Energy Technology Data Exchange (ETDEWEB)

Diplock, A.T.

1984-01-01

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

Molecular neutron activation analysis of selenium metabolites in urine

International Nuclear Information System (INIS)

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

1988-01-01

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

Nuclear transformations studies in selenium isotopes

International Nuclear Information System (INIS)

Lopez M, B.E.

1976-01-01

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

Serum selenium level and risk of lung cancer mortality

DEFF Research Database (Denmark)

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

2011-01-01

Serum selenium has been implicated as a risk factor for lung cancer, but the issue remains unsettled. We tested in a cohort of 3,333 males aged 53 to 74 years the hypothesis that a low serum selenium would be associated with an increased risk of lung cancer mortality.During 16 years, 167 subjects(5.......1%) died from lung cancer; 48 males (5.0%) among males with low serum selenium, 0.4-1.0 μmol·l(-1), n=965, 57 males (5.1%) among males with medium serum selenium, 1.1-1.2 μmol·l(-1), n=1,141, and 62 males (5.1%) among males with high serum selenium, 1.3-3.0 μmol·l(-1), n=1,227. After adjustment for age...... (chronic bronchitis and peak flow), referencing the lowest level of serum selenium HRs were 1.17(0.79-1.75), and 1.43(0.96-2.14), respectively. Among heavy smokers a high serum selenium was associated with a significantly increased risk of lung cancer mortality after taking into account all potential...

Recycling of high purity selenium from CIGS solar cell waste materials

Energy Technology Data Exchange (ETDEWEB)

Gustafsson, Anna M.K., E-mail: anna.gustafsson@chalmers.se; 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.

Gypsum amendment to soil can reduce selenium uptake by alfalfa grown in the presence of coal fly ash

International Nuclear Information System (INIS)

Arthur, M.A.; Rubin, G.; Woodbury, P.B.; Weinstein, L.H.

1993-01-01

Experiments in the field and greenhouse were conducted in the presence of coal fly ash to determine whether gypsum can reduce Se concentration in alfalfa (Medicago sativa L.). In the field experiment, conducted at a coal fly ash landfill, 11.2 t ha -1 gypsum was applied to soil as a top dressing to test the effect of gypsum in reducing selenium (Se) concentration in aboveground plant tissue. There were four treatment combinations of gypsum over a two year period, 1990, and 1991: (0, 0), (0, 11.2) (11.2, 0) and (11.2, 11.2). In 1991, the Se concentration was lower in alfalfa grown with gypsum, regardless of whether the gypsum was applied in both years or in only one year, indicating that the effect of gypsum application in the first year persisted into the second year. Since there was no increase in aboveground biomass with added gypsum, differences in Se concentration reflect a competitive interaction between S and Se. In the greenhouse experiment, 12 soil treatments were tested: three levels of fly ash (0, 10 and 20%) in combination with each of four levels of gypsum (0, 2.5, 5 and 7.5%). The Se concentration in alfalfa grown in 10% fly ash declined linearly with increasing gypsum dose, resulting in a reduction in Se concentration of 0.04 ± 0.02 μg g -1 for each 1% gypsum added for the first harvest and 0.06 ± 0.03 μg g -1 for each 1% gypsum added in the second harvest. Based on these results, gypsum may prove useful as a management tool to reduce the uptake of Se by plants growing on coal fly ash landfills

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

Czech Academy of Sciences Publication Activity Database

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

2004-01-01

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

Biomarkers of Selenium Chemoprevention of Prostate Cancer

National Research Council Canada - National Science Library

Dong, Yan

2003-01-01

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

Soil ingestion may be an important route for the uptake of contaminants by some reptiles.

Science.gov (United States)

Rich, C Nelson; Talent, Larry G

2009-02-01

Some species of reptiles regularly ingest soil in the wild. Therefore, we evaluated the importance of soil ingestion as a route for the uptake of contaminants in lizards. We used sand as a substitute for soil during the present study. Different groups of leopard geckos (Eublepharis macularius) were provided with a control and five sodium selenite-spiked sand mixtures during a 28-d study. Twenty lizards were assigned to a control group and to each of five selenium-spiked sand mixtures that consisted of nominal selenium (Se) concentrations of 0.05, 0.46, 4.57, 11.41, and 22.83 mg Se/kg dry sand. Leopard geckos readily ingested the Se-spiked sand. We observed concentration-related effects in several endpoints. Overall growth in body mass was the most sensitive endpoint and was significantly (p leopard geckos appear to be as sensitive to sodium selenite as birds and mammals. The present study suggests that ingestion of soil could be an important potential route for the uptake of soil contaminants in some reptiles and should be evaluated in ecotoxicological studies and risk analyses of reptiles.

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

DEFF Research Database (Denmark)

Outzen, Malene; Tjønneland, Anne; Larsen, Erik Huusfeldt

2015-01-01

Selenium status of the Danish population is below that assumed optimal for the suggested protective effects against chronic diseases, including certain cancers. Fish and shellfish are important dietary sources of selenium in Denmark. We investigated the effect of increased fish and mussel intake...... on selenium blood concentrations in a population with relatively low habitual dietary selenium intake. We randomly assigned 102 healthy men and women (all non-smokers) aged 48-76 years to an intervention group (n = 51) or a control group (n = 51). Intervention participants received 1000 g fish and mussels....../week for 26 weeks (similar to 50 mu g selenium/day). Controls received no intervention. Non-fasting blood samples were taken and whole blood selenium was determined using inductively coupled plasma-mass spectrometry (ICP-MS), and plasma selenoprotein P (SelP) was determined by high performance liquid...

Genome-Wide Association Study of Serum Selenium Concentrations

Directory of Open Access Journals (Sweden)

Ulrike Peters

2013-05-01

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

Erythrocytic glutathione peroxidase: Its relationship to plasma selenium in man

International Nuclear Information System (INIS)

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

1977-01-01

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

Selenium-containing indolyl compounds

DEFF Research Database (Denmark)

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

2017-01-01

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

Effect of irradiation on sod activity and selenium content in garlic

International Nuclear Information System (INIS)

Xu Weimin; Zheng Anjian; Yan Jianmin; Cao Qingsui; Wu Haihong; Cao Shifeng

2006-01-01

The effects of irradiation at 0.1 kGy, 1.0 kGy on SOD activity and the content of total selenium, inorganic selenium, organic selenium in garlic (Allium sativum L.) stored at 10 degree C or 25 degree C were investigated. The results indicated that irradiation treatment with 0.1 kGy, 1 kGy significantly slowed the reduction of SOD activities in garlic stored at 10 degree C or 25 degree C, while the treatment irradiation had no influence on the content of all kinds of selenium. But the garlic stored at 25 degree C had higher content of total selenium, inorganic selenium, organic selenium than that in garlic stored at 10 degree C. (authors)

Thyroid hormones regulate selenoprotein expression and selenium status in mice.

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Jens Mittag

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

EURRECA—Estimating Selenium Requirements for Deriving Dietary Reference Values

NARCIS (Netherlands)

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

2013-01-01

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

Ecological Importance of Insects in Selenium Biogenic Cycling

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Nadezhda Golubkina

2014-01-01

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

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

Science.gov (United States)

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

2015-01-01

Selenium status of the Danish population is below that assumed optimal for the suggested protective effects against chronic diseases, including certain cancers. Fish and shellfish are important dietary sources of selenium in Denmark. We investigated the effect of increased fish and mussel intake on selenium blood concentrations in a population with relatively low habitual dietary selenium intake. We randomly assigned 102 healthy men and women (all non-smokers) aged 48–76 years to an intervention group (n = 51) or a control group (n = 51). Intervention participants received 1000 g fish and mussels/week for 26 weeks (~50 μg selenium/day). Controls received no intervention. Non-fasting blood samples were taken and whole blood selenium was determined using inductively coupled plasma-mass spectrometry (ICP-MS), and plasma selenoprotein P (SelP) was determined by high performance liquid chromatography coupled to ICP-MS. All available observations were included in linear multiple regression analysis to evaluate the effect of the intervention. The difference in mean change for intervention compared with control persons was 14.9 ng/mL (95% CI: 10.2, 19.7) for whole blood selenium, and 7.0 ng/mL (95% CI: 3.1, 10.9) for plasma SelP (Weeks 0–26). Selenium concentrations were significantly increased after 26 weeks of intervention, albeit to a lower degree than expected. PMID:25599275

Sulfur, selenium, tellurium and polonium

International Nuclear Information System (INIS)

Berry, F.J.

1987-01-01

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

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

Science.gov (United States)

Schomburg, Lutz

2011-10-18

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

Toenail mercury and dyslipidemia: Interaction with selenium.

Science.gov (United States)

Park, Kyong; Seo, Eunmin

2017-01-01

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

[Is plasma selenium correlated to transthyretin levels in critically ill patients?

Science.gov (United States)

Freitas, Renata G B O N; Nogueira, Roberto Jose Negrão; Cozzolino, Silvia Maria Franciscato; Vasques, Ana Carolina Junqueira; Ferreira, Matthew Thomas; Hessel, Gabriel

2017-06-05

Selenium is an essential trace element, but critically ill patients using total parenteral nutrition (PN) do not receive selenium because this mineral is not commonly offered. Threfore, the eval uation of plasma selenium levels is very important for treating or preventing this deficiency. Recent studies have shown that transthyretin may reflect the selenium intake and could be considered a biomarker. However, this issue is still little explored in the literature. This study aims to investigate the correlation of transthyretin with the plasma selenium of critically ill patients receiving PN. This was a prospective cohort study with 44 patients using PN without selenium. Blood samples were carried out in 3 stages: initial, 7th and 14th day of PN. In order to evaluate the clinical condition and the inflammatory process, albumin, C-reactive protein (CRP), transthyretin, creatinine and HDL cholesterol levels were observed. To assess the selenium status, plasma selenium and glutathione peroxidase (GPx) in whole blood were measured. Descriptive analyses were performed and the ANOVA, Mann-Whitney and Spearman's coefficient tests were conducted; we assumed a significance level of 5%. A positive correlation of selenium with the GPx levels (r = 0.46; p = 0.03) was identified. During two weeks, there was a positive correlation of transthyretin with plasma selenium (r = 0.71; p = 0.05) regardless of the CRP values. Transthyretin may have reflected plasma selenium, mainly because the correlation was verified after the acute phase.

Search for relevant indications for selenium supplementation in thyroid diseases.

Science.gov (United States)

Wojciechowska-Durczynska, Katarzyna; Lewinski, Andrzej

2017-08-01

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

Selenium Speciation and Management in Wet FGD Systems

Energy Technology Data Exchange (ETDEWEB)

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

2012-02-29

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

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

NARCIS (Netherlands)

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

2010-01-01

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

Analyses of Selenotranscriptomes and Selenium Concentrations in Response to Dietary Selenium Deficiency and Age Reveal Common and Distinct Patterns by Tissue and Sex in Telomere-Dysfunctional Mice.

Science.gov (United States)

Cao, Lei; Zhang, Li; Zeng, Huawei; Wu, Ryan Ty; Wu, Tung-Lung; Cheng, Wen-Hsing

2017-10-01

Background: The hierarchies of tissue selenium distribution and selenotranscriptomes are thought to critically affect healthspan and longevity. Objective: We determined selenium status and selenotranscriptomes in response to long-term dietary selenium deficiency and age in tissues of male and female mice. Methods: Weanling telomerase RNA component knockout C57BL/6 mice were fed a selenium-deficient (0.03 mg Se/kg) Torula yeast-based AIN-93G diet or a diet supplemented with sodium selenate (0.15 mg Se/kg) until age 18 or 24 mo. Plasma, hearts, kidneys, livers, and testes were collected to assay for selenotranscriptomes, selected selenoproteins, and tissue selenium concentrations. Data were analyzed with the use of 2-factor ANOVA (diet × age) in both sexes. Results: Dietary selenium deficiency decreased ( P ≤ 0.05) selenium concentrations (65-72%) and glutathione peroxidase (GPX) 3 (82-94%) and selenoprotein P (SELENOP) (17-41%) levels in the plasma of both sexes of mice and mRNA levels (9-68%) of 4, 4, and 12 selenoproteins in the heart, kidney, and liver of males, respectively, and 5, 16, and 14 selenoproteins, respectively, in females. Age increased selenium concentrations and SELENOP levels (27% and 30%, respectively; P ≤ 0.05) in the plasma of males only but decreased (12-46%; P selenium deficiency and age in ≥1 tissue or sex, or both. Dietary selenium deficiency upregulated (40-160%; P ≤ 0.05) iodothyronine deiodinase 2 ( Dio2 ) and selenoprotein N ( Selenon ) in the kidneys of males. Age upregulated (11-44%; P selenium status and selenotranscriptomes because of dietary selenium deficiency and age. © 2017 American Society for Nutrition.

Mechanisms of Selenium Enrichment and Measurement in Brassicaceous Vegetables, and Their Application to Human Health

Directory of Open Access Journals (Sweden)

Melanie Wiesner-Reinhold

2017-08-01

Full Text Available Selenium (Se is an essential micronutrient for human health. Se deficiency affects hundreds of millions of people worldwide, particularly in developing countries, and there is increasing awareness that suboptimal supply of Se can also negatively affect human health. Selenium enters the diet primarily through the ingestion of plant and animal products. Although, plants are not dependent on Se they take it up from the soil through the sulphur (S uptake and assimilation pathways. Therefore, geographic differences in the availability of soil Se and agricultural practices have a profound influence on the Se content of many foods, and there are increasing efforts to biofortify crop plants with Se. Plants from the Brassicales are of particular interest as they accumulate and synthesize Se into forms with additional health benefits, such as methylselenocysteine (MeSeCys. The Brassicaceae are also well-known to produce the glucosinolates; S-containing compounds with demonstrated human health value. Furthermore, the recent discovery of the selenoglucosinolates in the Brassicaceae raises questions regarding their potential bioefficacy. In this review we focus on Se uptake and metabolism in the Brassicaceae in the context of human health, particularly cancer prevention and immunity. We investigate the close relationship between Se and S metabolism in this plant family, with particular emphasis on the selenoglucosinolates, and consider the methodologies available for identifying and quantifying further novel Se-containing compounds in plants. Finally, we summarize the research of multiple groups investigating biofortification of the Brassicaceae and discuss which approaches might be most successful for supplying Se deficient populations in the future.

COMPARISON OF DETERMINING METHODS REGARDING SELENIUM CONTENT IN WHEAT PLANT

Directory of Open Access Journals (Sweden)

Mihaela Monica Stanciu-Burileanu

2010-01-01

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

Selenium and the thyroid: A close-knit connection

Directory of Open Access Journals (Sweden)

Ashok K Bhuyan

2012-01-01

Full Text Available Introduction: In areas with severe selenium deficiency higher incidence of thyroiditis has been reported due to a decreased activity of selenium-dependent glutathione peroxidase enzyme within thyroid cells. Aims and Objective: To study the effect of selenium supplementation in patients with autoimmune thyroid disease. Materials and Methods: This is a blinded placebo-controlled prospective study done in 60 patients with autoimmune thyroid disease (as defined by an anti-thyroid peroxidase antibody (TPOAb level more than 150 IU/ml irrespective of the baseline thyroid status. Patients with overt hyperthyroidism who are on antithyroid drugs, patients on any other medication, which may alter the immunity status of the patients, and pregnant patients were excluded from the study. Patients were randomized into two age and TPOAb-matched groups; 30 patients received 200 μg of sodium selenite/day, orally, for 3 months, and 30 patients received placebo. All hypothyroid patients were given l-thyroxine replacement. Results: Of 30 patients in the selenium treated group, 6 patients were overtly hypothyroid, 15 were subclinical hypothyroid, 6 were euthyroid, and 3 were subclinical hyperthyroid. The mean TPOAb concentration decreased significantly by 49.5% (P < 0.013 in the selenium treated group versus 10.1% (P < 0.95 in the placebo-treated group. Conclusion: Selenium substitution has a significant impact on inflammatory activity in thyroid-specific autoimmune disease. It would be of interest to determine whether early treatment with selenium in patients with newly developed autoimmune thyroiditis may delay or even prevent the natural course of these diseases.

Hypothalamic and Striatal Insulin Action Suppresses Endogenous Glucose Production and May Stimulate Glucose Uptake During Hyperinsulinemia in Lean but Not in Overweight Men.

Science.gov (United States)

Heni, Martin; Wagner, Robert; Kullmann, Stephanie; Gancheva, Sofiya; Roden, Michael; Peter, Andreas; Stefan, Norbert; Preissl, Hubert; Häring, Hans-Ulrich; Fritsche, Andreas

2017-07-01

Intranasal spray application facilitates insulin delivery to the human brain. Although brain insulin modulates peripheral metabolism, the mechanisms involved remain elusive. Twenty-one men underwent two hyperinsulinemic-euglycemic clamps with d-[6,6- 2 H 2 ]glucose infusion to measure endogenous glucose production and glucose disappearance. On two separate days, participants received intranasal insulin or placebo. Insulin spillover into circulation after intranasal insulin application was mimicked by an intravenous insulin bolus on placebo day. On a different day, brain insulin sensitivity was assessed by functional MRI. Glucose infusion rates (GIRs) had to be increased more after nasal insulin than after placebo to maintain euglycemia in lean but not in overweight people. The increase in GIRs was associated with regional brain insulin action in hypothalamus and striatum. Suppression of endogenous glucose production by circulating insulin was more pronounced after administration of nasal insulin than after placebo. Furthermore, glucose uptake into tissue tended to be higher after nasal insulin application. No such effects were detected in overweight participants. By increasing insulin-mediated suppression of endogenous glucose production and stimulating peripheral glucose uptake, brain insulin may improve glucose metabolism during systemic hyperinsulinemia. Obese people appear to lack these mechanisms. Therefore, brain insulin resistance in obesity may have unfavorable consequences for whole-body glucose homeostasis. © 2017 by the American Diabetes Association.

Recent trends in selenium regulation and management

International Nuclear Information System (INIS)

Sobolewski, A.

2010-01-01

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

Selenium accumulation by plants.

Science.gov (United States)

White, Philip J

2016-02-01

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

Learning selenium testing tools with Python

CERN Document Server

Gundecha, Unmesh

2014-01-01

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

Comparison between selenium and tellurium clusters

International Nuclear Information System (INIS)

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

1991-01-01

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

Selenium Accumulating Leafy Vegetables Are a Potential Source of Functional Foods

Directory of Open Access Journals (Sweden)

Petro E. Mabeyo

2015-01-01

Full Text Available 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.

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

Science.gov (United States)

Gramm, H J; Kopf, A; Brätter, P

1995-03-01

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

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

DEFF Research Database (Denmark)

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

2013-01-01

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

Artificial Neural Network (ANN) design for Hg-Se interactions and their effect on reduction of Hg uptake by radish plant

International Nuclear Information System (INIS)

Kumar Rohit Raj; Abhishek Kardam; Shalini Srivastava; Jyoti Kumar Arora

2010-01-01

The tendency of selenium to interact with heavy metals in presence of naturally occurring species has been exploited for the development of green bioremediation of toxic metals from soil using Artificial Neural Network (ANN) modeling. The cross validation of the data for the reduction in uptake of Hg(II) ions in the plant R. sativus grown in soil and sand culture in presence of selenium has been used for ANN modeling. ANN model based on the combination of back propagation and principal component analysis was able to predict the reduction in Hg uptake with a sigmoid axon transfer function. The data of fifty laboratory experimental sets were used for structuring single layer ANN model. Series of experiments resulted into the performance evaluation based on considering 20% data for testing and 20% data for cross validation at 1,500 Epoch with 0.70 momentums The Levenberg-Marquardt algorithm (LMA) was found as the best of BP algorithms with a minimum mean squared error at the eighth place of the decimal for training (MSE) and cross validation. (author)

Effects of organic selenium in broiler feed on the content of selenium and fatty acid profile in lipids of thigh muscle tissue

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Zlata Kralik

2013-01-01

Full Text Available The aim of our study was to determine the effects of selenium supplementation to broiler feed on the content of selenium, total fatty acids in lipids and on the oxidative stability of broiler thigh muscle tissue. The experiment involved 40 broilers fattened for 42 days. During the first three weeks, all broilers consumed starter diet containing 22% crude protein. After three weeks, broilers were divided into two groups and fed finisher diets containing 18% crude protein and supplemented with 3% sunflower oil and 3% linseed oil. Group 1 was not administered artificial selenium; Group 2 was supplemented with organic selenium at the amount of 0.5 mg Se/kg of feed. Significantly higher (P P P > 0.05 and increase of linolenic acid and total n-3 polyunsaturated fatty acids (P < 0.05 in thigh muscle tissue of broilers. Since selenium and n-3 polyunsaturated fatty acids are nutricines, our results show that the produced broiler meat may be considered as functional food.

Optimization of Selenium-enriched Candida utilis by Response Surface Methodology

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ZHANG Fan

2014-12-01

Full Text Available The fermentation conditions of selenium enrichment by Candida utilis were studied. Based on the results of the single factor experiment, three factors including the concentration of sodium selenite, inital pH and incubation temperature were selected. The response surface method was used to optimize the various factors. The optimal conditions were obtained as follows: incubation time was 30 h, time of adding selenium was mid-logarithmic, the sodium selenite concentration was 35 mg·L-1 with inital pH of 6.6, incubation concentration of 10%, incubation temperature of 27 ℃, the medium volume of 150 mL/500 mL, respectively. Under the optimal condition, the biomass was 6.87 g·L-1. The total selenium content of Candida utilis was 12 639.7 μg·L-1, and the selenium content of the cells was 1 839.8 μg·g-1, in which sodium selenite conversion rate was 79.1% and the organic selenium was higher than 90%. The actual value of selenium content was substantially consistent with the theoretical value, and the response surface methodology was applicable for the fermentation conditions of selenium enriched by Candida utilis.

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

Energy Technology Data Exchange (ETDEWEB)

Nicholas Ralston; Laura Raymond

2008-03-01

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

Selenium toxicity: cause and effects in aquatic birds

Science.gov (United States)

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

2002-01-01

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

Dietary Selenium in Adjuvant Therapy of Viral and Bacterial Infections12

Science.gov (United States)

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

2015-01-01

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

Selenium inhibits the phytotoxicity of mercury in garlic (Allium sativum)

Energy Technology Data Exchange (ETDEWEB)

Zhao, Jiating [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Gao, Yuxi, E-mail: gaoyx@ihep.ac.cn [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Li, Yu-Feng; Hu, Yi; Peng, Xiaomin [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Dong, Yuanxing [Department of Physics, Xinzhou Teachers University, Xinzhou 034000 (China); Li, Bai; Chen, Chunying [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chai, Zhifang, E-mail: chaizf@ihep.ac.cn [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2013-08-15

To investigate the influence of selenium on mercury phytotoxicity, the levels of selenium and mercury were analyzed with inductively coupled plasma-mass spectrometry (ICP-MS) in garlic tissues upon exposure to different dosages of inorganic mercury (Hg{sup 2+}) and selenite (SeO{sub 3}{sup 2−}) or selenate (SeO{sub 4}{sup 2−}). The distributions of selenium and mercury were examined with micro-synchrotron radiation X-ray fluorescence (μ-SRXRF), and the mercury speciation was investigated with micro-X-ray absorption near edge structure (μ-XANES). The results show that Se at higher exposure levels (>1 mg/L of SeO{sub 3}{sup 2−} or SeO{sub 4}{sup 2−}) would significantly inhibit the absorption and transportation of Hg when Hg{sup 2+} levels are higher than 1 mg/L in culture media. SeO{sub 3}{sup 2−} and SeO{sub 4}{sup 2−} were found to be equally effective in reducing Hg accumulation in garlic. The inhibition of Hg uptake by Se correlates well with the influence of Se on Hg phytotoxicity as indicated by the growth inhibition factor. Elemental imaging using μ-SRXRF also shows that Se could inhibit the accumulation and translocation of Hg in garlic. μ-XANES analysis shows that Hg is mainly present in the forms of Hg–S bonding as Hg(GSH){sub 2} and Hg(Met){sub 2}. Se exposure elicited decrease of Hg–S bonding in the form of Hg(GSH){sub 2}, together with Se-mediated alteration of Hg absorption, transportation and accumulation, may account for attenuated Hg phytotoxicity by Se in garlic. -- Highlights: ► Hg phytotoxicity can be mitigated by Se supplement in garlic growth. ► Se can inhibit the accumulation and transportation of Hg in garlic tissues. ► Localization and speciation of Hg in garlic can be modified by Se.

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

Science.gov (United States)

Spiller, Henry A

2018-05-01

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

Reduced selenium-binding protein 1 in breast cancer correlates with poor survival and resistance to the anti-proliferative effects of selenium.

Directory of Open Access Journals (Sweden)

Sheng Zhang

Full Text Available Supplemental dietary selenium is associated with reduced incidence of many cancers. The antitumor function of selenium is thought to be mediated through selenium-binding protein 1 (SELENBP1. However, the significance of SELENBP1 expression in breast cancer is still largely unknown. A total of 95 normal and tumor tissues assay and 12 breast cancer cell lines were used in this study. We found that SELENBP1 expression in breast cancer tissues is reduced compared to normal control. Low SELENBP1 expression in ER(+ breast cancer patients was significantly associated with poor survival (p<0.01, and SELENBP1 levels progressively decreased with advancing clinical stages of breast cancer. 17-β estradiol (E2 treatment of high SELENBP1-expressing ER(+ cell lines led to a down-regulation of SELENBP1, a result that did not occur in ER(- cell lines. However, after ectopic expression of ER in an originally ER(- cell line, down-regulation of SELENBP1 upon E2 treatment was observed. In addition, selenium treatment resulted in reduced cell proliferation in endogenous SELENBP1 high cells; however, after knocking-down SELENBP1, we observed no significant reduction in cell proliferation. Similarly, selenium has no effect on inhibition of cell proliferation in low endogenous SELENBP1 cells, but the inhibitory effect is regained following ectopic SELENBP1 expression. Furthermore, E2 treatment of an ER silenced high endogenous SELENBP1 expressing cell line showed no abolishment of cell proliferation inhibition upon selenium treatment. These data indicate that SELENBP1 expression is regulated via estrogen and that the cell proliferation inhibition effect of selenium treatment is dependent on the high level of SELENBP1 expression. Therefore, the expression level of SELENBP1 could be an important marker for predicting survival and effectiveness of selenium supplementation in breast cancer. This is the first study to reveal the importance of monitoring SELENBP1 expression

Suppression of LPS-induced inflammatory responses in macrophages infected with Leishmania

Directory of Open Access Journals (Sweden)

Kelly Ben L

2010-02-01

Full Text Available Abstract Background Chronic inflammation activated by macrophage innate pathogen recognition receptors such as TLR4 can lead to a range of inflammatory diseases, including atherosclerosis, Crohn's disease, arthritis and cancer. Unlike many microbes, the kinetoplastid protozoan pathogen Leishmania has been shown to avoid and even actively suppress host inflammatory cytokine responses, such as LPS-induced IL-12 production. The nature and scope of Leishmania-mediated inflammatory cytokine suppression, however, is not well characterized. Advancing our knowledge of such microbe-mediated cytokine suppression may provide new avenues for therapeutic intervention in inflammatory disease. Methods We explored the kinetics of a range of cytokine and chemokine responses in primary murine macrophages stimulated with LPS in the presence versus absence of two clinically distinct species of Leishmania using sensitive multiplex cytokine analyses. To confirm that these effects were parasite-specific, we compared the effects of Leishmania uptake on LPS-induced cytokine expression with uptake of inert latex beads. Results Whilst Leishmania uptake alone did not induce significant levels of any cytokine analysed in this study, Leishmania uptake in the presence of LPS caused parasite-specific suppression of certain LPS-induced pro-inflammatory cytokines, including IL-12, IL-17 and IL-6. Interestingly, L. amazonensis was generally more suppressive than L. major. We also found that other LPS-induced proinflammatory cytokines, such as IL-1α, TNF-α and the chemokines MIP-1α and MCP-1 and also the anti-inflammatory cytokine IL-10, were augmented during Leishmania uptake, in a parasite-specific manner. Conclusions During uptake by macrophages, Leishmania evades the activation of a broad range of cytokines and chemokines. Further, in the presence of a strong inflammatory stimulus, Leishmania suppresses certain proinflammatory cytokine responses in a parasite

Influence of dietary sodium selenite on tissue selenium levels of growing pigs

International Nuclear Information System (INIS)

Moksnes, K.; Tollersrud, S.; Larsen, H.J.

1982-01-01

Twenty Norwegian Landrace pigs were divided into 5 groups and fed a basal diet consisting of a mixture of dried skim milk and whey powder together with ground barley. The diet was supplemented with 0, 0.2, 0.8, 1.2, and 2.2 μg/g selenium as sodium selenite and was fed for 12 weeks. The muscle selenium level was increased by a factor of about 4 and the liver selenium by a factor of about 12 when the dietary selenium supplement was increased from zero to 2.2μg/g. There was a significant linear correlation between dietary selenium and selenium concentrations in tissues. Possible benefit for humans consuming meat from animals having received the selenium doses used in this experiment are discussed. (author)

Low selenium and reduced cognitive function in a cohort elderly study

Institute of Scientific and Technical Information of China (English)

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

2010-01-01

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

Selenium as an essential micronutrient: roles in cell cycle and apoptosis.

Science.gov (United States)

Zeng, Huawei

2009-03-23

Selenium is an essential trace element for humans and animals, and selenium deficiency is associated with several disease conditions such as immune impairment. In addition, selenium intakes that are greater than the recommended daily allowance (RDA) appear to protect against certain types of cancers. In humans and animals, cell proliferation and death must be regulated to maintain tissue homeostasis, and it has been well documented that numerous human diseases are directly related to the control of cell cycle progression and apoptosis. Thus, the elucidation of the mechanisms by which selenium regulates the cell cycle and apoptosis can lead to a better understanding of the nature of selenium's essentiality and its role in disease prevention. This article reviews the status of knowledge concerning the effect of selenium on cell cycle and apoptosis.

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

Energy Technology Data Exchange (ETDEWEB)

Dubois, Maitee [Institut national de la recherche scientifique - Eau, Terre et Environnement, Universite du Quebec, Quebec City, Quebec, G1K 9A9 (Canada); Hare, Landis [Institut national de la recherche scientifique - Eau, Terre et Environnement, Universite du Quebec, Quebec City, Quebec, G1K 9A9 (Canada)], E-mail: landis@ete.inrs.ca

2009-03-15

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

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

International Nuclear Information System (INIS)

Dubois, Maitee; Hare, Landis

2009-01-01

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

Quantitative evaluation of contrast agent uptake in standard fat-suppressed dynamic contrast-enhanced MRI examinations of the breast.

Science.gov (United States)

Kousi, Evanthia; Smith, Joely; Ledger, Araminta E; Scurr, Erica; Allen, Steven; Wilson, Robin M; O'Flynn, Elizabeth; Pope, Romney J E; Leach, Martin O; Schmidt, Maria A

2018-01-01

To propose a method to quantify T 1 and contrast agent uptake in breast dynamic contrast-enhanced (DCE) examinations undertaken with standard clinical fat-suppressed MRI sequences and to demonstrate the proposed approach by comparing the enhancement characteristics of lobular and ductal carcinomas. A standard fat-suppressed DCE of the breast was performed at 1.5 T (Siemens Aera), followed by the acquisition of a proton density (PD)-weighted sequence, also fat suppressed. Both sequences were characterized with test objects (T 1 ranging from 30 ms to 2,400 ms) and calibration curves were obtained to enable T 1 calculation. The reproducibility and accuracy of the calibration curves were also investigated. Healthy volunteers and patients were scanned with Ethics Committee approval. The effect of B 0 field inhomogeneity was assessed in test objects and healthy volunteers. The T 1 of breast tumors was calculated at different time points (pre-, peak-, and post-contrast agent administration) for 20 patients, pre-treatment (10 lobular and 10 ductal carcinomas) and the two cancer types were compared (Wilcoxon rank-sum test). The calibration curves proved to be highly reproducible (coefficient of variation under 10%). T 1 measurements were affected by B 0 field inhomogeneity, but frequency shifts below 50 Hz introduced only 3% change to fat-suppressed T 1 measurements of breast parenchyma in volunteers. The values of T 1 measured pre-, peak-, and post-contrast agent administration demonstrated that the dynamic range of the DCE sequence was correct, that is, image intensity is approximately directly proportional to 1/T 1 for that range. Significant differences were identified in the width of the distributions of the post-contrast T 1 values between lobular and ductal carcinomas (P contrast T 1 values, potentially related to their infiltrative growth pattern. This work has demonstrated the feasibility of fat-suppressed T 1 measurements as a tool for clinical studies. The

Selenium intake and metabolic syndrome: A systematic review.

Science.gov (United States)

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

2018-03-02

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

Activation analysis of selenium in odorous vegetable foods

International Nuclear Information System (INIS)

Suzuki, Shogo; Hirai, Shoji; Noda, Katsuhiko.

1981-01-01

The selenium in odorous vegetables was analyzed by nondestructive neutron activation analysis using 75 Se, by the γ-ray coincidence method with a Ge(Li) and a NaI(Tl) detectors of definite energy ranges. By means of the coincidence counting, the background spectrum in 75 Se in the vicinity of 265 KeV was able to be reduced to about 1/20 of that by the former detector alone, so that the 75 Se detection sensitivity was raised over fourfold. Thus the selenium in odorous vegetables was able to be determined down to the content as low as 0.02 μg/g. The selenium content in garlic bulbs was 0.02 - 0.31 μg/g, and in onion bulbs 0.02 - 0.05 μg/g, both of which agreed well with those by fluorometry. In other odorous vegetables, the selenium content was as little as 0.1 μg/g or lower. It has been said that the selenium content is relatively large along with sulfur because of the same group, but it was found to be fairly small in the odorous vegetables. (Mori, K.)

[Plasma selenium and peripartum cardiomyopathy in Bamako, Mali].

Science.gov (United States)

Cénac, A; Touré, K; Diarra, M B; Sergeant, C; Jobic, Y; Sanogo, K; Dembele, M; Fayol, V; Simonoff, M

2004-01-01

Peripartum heart failure due to unexplained dilated cardiomyopathy is a common disorder as Savannak-Sahelian Africa. One of the many suspected risk factors identified is selenium deficiency. The purpose of this study was to measure plasma selenium levels in patients with peripartum heart failure due to cardiomyopathy in Bamako, Republic of Mali and compare data with healthy Sahalian women with the same obstetrical status. Plasma selenium was measured in a patient group consisting of 28 Malian women presenting peripartum heart failure and in a control group of 28 healthy breast-feeding Nigerien women of comparable age. The criteria for matching the two groups was parity (similar number of deliveries) since multiparity is a risk factor for peripartum cardiomyopathy. The Wilcoxon test (nonparametric) was used to compare the 2 groups considering up value < 0.05 as significant. Plasma selenium was significantly lower in patients from Mali than in controls from Niger (65 +/- 17 ng/ml vs. 78 +/- 17 ng/ml, p = 0.01). The results of this study showing lower plasma selenium in Bamako patients with peripartum cardiomyopathy than in a matching healthy control population confirms the previous data from the Niamey study.

Selenium and Lung Cancer: A Systematic Review and Meta Analysis

Science.gov (United States)

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

2011-01-01

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

Mixed Surfactant Template Method for Preparation of Nanometer Selenium

Directory of Open Access Journals (Sweden)

Zhi-Lin Li

2009-01-01

Full Text Available Selenium nanoparticles have been synthesized in an aqueous solution by using sodium dodecyl sulfate and polyvinyl alcohol as a soft template. The factors on synthesis, such as reaction time, concentration of reactants and ultrasonic irradiation were studied. The uniform stable selenium nanospheres were obstained in the conditions of 1.0 (mass fraction sodium dodecyl sulfate, 1.0 (mass fraction polyvinyl alcohol, n(Vc:n(H2SeO3=7:1 and 7 minutes after the initiation of the reaction at room temperature. The average particle size of selenium is about 30 nm. The product was characterized by UV and TEM. Finally the applications of the red element nanometer selenium in anti-older cosmetics are presented.

Effects of selenium oxyanions on the white-rot fungus Phanerochaete chrysosporium

KAUST Repository

Espinosa-Ortiz, Erika J.

2014-10-24

The ability of Phanerochaete chrysosporium to reduce the oxidized forms of selenium, selenate and selenite, and their effects on the growth, substrate consumption rate, and pellet morphology of the fungus were assessed. The effect of different operational parameters (pH, glucose, and selenium concentration) on the response of P. chrysosporium to selenium oxyanions was explored as well. This fungal species showed a high sensitivity to selenium, particularly selenite, which inhibited the fungal growth and substrate consumption when supplied at 10 mg L−1 in the growth medium, whereas selenate did not have such a strong influence on the fungus. Biological removal of selenite was achieved under semi-acidic conditions (pH 4.5) with about 40 % removal efficiency, whereas less than 10 % selenium removal was achieved for incubations with selenate. P. chrysosporium was found to be a selenium-reducing organism, capable of synthesizing elemental selenium from selenite but not from selenate. Analysis with transmission electron microscopy, electron energy loss spectroscopy, and a 3D reconstruction showed that elemental selenium was produced intracellularly as nanoparticles in the range of 30–400 nm. Furthermore, selenite influenced the pellet morphology of P. chrysosporium by reducing the size of the fungal pellets and inducing their compaction and smoothness.

The expression of selenium-binding protein 1 is decreased in uterine leiomyoma

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Quddus M Ruhul

2010-12-01

Full Text Available Abstract Background Selenium has been shown to inhibit cancer development and growth through the mediation of selenium-binding proteins. Decreased expression of selenium-binding protein 1 has been reported in cancers of the prostate, stomach, colon, and lungs. No information, however, is available concerning the roles of selenium-binding protein 1 in uterine leiomyoma. Methods Using Western Blot analysis and immunohistochemistry, we examined the expression of selenium-binding protein 1 in uterine leiomyoma and normal myometrium in 20 patients who had undergone hysterectomy for uterine leiomyoma. Results and Discussion The patient age ranged from 34 to 58 years with a mean of 44.3 years. Proliferative endometrium was seen in 8 patients, secretory endometrium in 7 patients, and atrophic endometrium in 5 patients. Two patients showed solitary leiomyoma, and eighteen patients revealed 2 to 5 tumors. Tumor size ranged from 1 to 15.5 cm with a mean of 4.3 cm. Both Western Blot analysis and immunohistochemistry showed a significant lower level of selenium-binding protein 1 in leiomyoma than in normal myometrium. Larger tumors had a tendency to show a lower level of selenium-binding protein 1 than smaller ones, but the difference did not reach a statistical significance. The expression of selenium-binding protein 1 was the same among patients with proliferative, secretory, and atrophic endometrium in either leiomyoma or normal myometrium. Also, we did not find a difference of selenium-binding protein 1 level between patients younger than 45 years and older patients in either leiomyoma or normal myometrium. Conclusions Decreased expression of selenium-binding protein 1 in uterine leiomyoma may indicate a role of the protein in tumorigenesis. Our findings may provide a basis for future studies concerning the molecular mechanisms of selenium-binding protein 1 in tumorigenesis as well as the possible use of selenium in prevention and treatment of uterine

HORMONAL REGULATION OF SELENIUM ACCUMULATION BY PLANTS

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N. A. Golubkina

2015-01-01

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

Assessment of dissolved-selenium concentrations and loads in the lower Gunnison River Basin, Colorado, as part of the Selenium Management Program, from 2011 to 2016

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Henneberg, Mark F.

2018-04-23

The Gunnison Basin Selenium Management Program implemented a water-quality monitoring network in 2011 in the lower Gunnison River Basin in Colorado. Selenium is a trace element that bioaccumulates in aquatic food chains and can cause reproductive failure, deformities, and other harmful effects. This report presents the percentile values of selenium because regulatory agencies in Colorado make decisions based on the U.S. Environmental Protection Agency (EPA) Clean Water Act Section 303(d) that uses percentile values of concentration. Also presented are dissolved-selenium loads at 18 sites in the lower Gunnison River Basin for water years (WYs) 2011–2016 (October 1, 2010, through September 30, 2016). Annual dissolved-selenium loads were calculated for five sites with continuous U.S. Geological Survey (USGS) streamflow-gaging stations. Annual dissolved-selenium loads for WY 2011 through WY 2016 ranged from 179 and 391 pounds (lb) at Uncompahgre River at Colona to 11,100 and 17,300 lb at Gunnison River near Grand Junction (herein called Whitewater), respectively. Instantaneous loads were calculated for five sites with continuous U.S. Geological Survey (USGS) streamflow-gaging stations and 13 ancillary sites where discrete water-quality sampling also took place, using discrete water-quality samples and the associated discharge measurements collected during the period. Median instantaneous loads ranged from 0.01 pound per day (lb/d) at Smith Fork near Lazear to 33.0 lb/d at Whitewater. Mean instantaneous loads ranged from 0.06 lb/d at Smith Fork near Lazear to 36.2 lb/d at Whitewater. Most tributary sites in the basin had a median instantaneous dissolved-selenium load of less than 20.0 lb/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

Determination of selenium status using the nail biologic monitor in a canine model

International Nuclear Information System (INIS)

Steven Morris, J.; Spate, V.L.; Ruth Ann Ngwenyama; Waters, D.J.

2012-01-01

Toenails and fingernails are routinely used to estimate selenium status in epidemiological studies; however, literature validating nail selenium concentration as a surrogate for critical organs is limited. In this study diets of intact male dogs were selenium supplemented at two physiological levels (3 and 6 μg/kg/day) in two different forms, selenomethionine and selenium-enriched bioformed yeast. The selenium-adequate basal diet consumed by the treatment and control groups during the 4-week run-in period and throughout the trial contained 0.3 ppm selenium. After 7 months the dogs in the two treatment groups and the control group were euthanized. Representative tissue samples from prostate, brain, liver, heart and skeletal muscle were collected, rinsed and frozen. Toenail clippings from multiple toes were also collected. Selenium was determined by neutron activation analysis using Se77m (half life = 17.4 s) at the University of Missouri Research Reactor Center. NIST SRM 1577, Bovine Liver was analyzed as a quality control. The analysts were blinded to control and treatment group assignments. As expected, tissue selenium levels increased proportionally with supplementation. A slightly greater increase in tissue selenium was observed for the purified selenomethionine compared to the bioformed yeast; however this trend was significant only for brain tissue. Toenail selenium concentrations and tissue selenium were highly correlated (p < 0.003) with Pearson coefficients of 0.759 (skeletal muscle), 0.745 (heart), 0.729 (brain), 0.723 (prostate), and 0.632 (liver). The toenail biologic monitor accurately assesses selenium status in skeletal muscle, heart, brain, prostate, and liver in the canine model. (author)

Supplementation of Merino ewes with vitamin E plus selenium increases α-tocopherol and selenium concentrations in plasma of the lamb but does not improve their immune function.

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Sterndale, S; Broomfield, S; Currie, A; Hancock, S; Kearney, G A; Lei, J; Liu, S; Lockwood, A; Scanlan, V; Smith, G; Thompson, A N

2018-05-01

Vitamin E and selenium have been reported to improve immune function across a range of species. Ewes lambing on poor-quality dry pasture in autumn in Western Australia are at risk of being deficient in vitamin E and selenium at lambing thus predisposing their lambs to deficiencies and increasing the risk of infection and disease. This study tested the hypotheses that (i) supplementation of autumn-lambing ewes with vitamin E plus selenium in late gestation will increase the concentrations of vitamin E and selenium in plasma in the ewe and lamb and (ii) that the increased concentrations of vitamin E and selenium in plasma in the lambs will improve their innate and adaptive immune responses and thus survival. Pregnant Merino ewes were divided into a control group (n=58) which received no supplementation or a group supplemented with vitamin E plus selenium (n=55). On days 111, 125 and 140 of pregnancy ewes in the vitamin E plus selenium group were given 4 g all-rac-α-tocopherol acetate orally. On day 111 the ewes were also given 60 mg of selenium as barium selenate by subcutaneous injection. The concentrations of α-tocopherol and selenium were measured in ewes and/or lambs from day 111 of pregnancy to 14 weeks of age±10 days (weaning). Immune function of the lamb was assessed by analysing the numbers and phagocytic capacities of monocytes and polymorphonuclear leucocytes and plasma IgG and anti-tetanus toxoid antibody concentrations between birth and 14 weeks of age±10 days. Maternal supplementation with vitamin E plus selenium increased the concentration of α-tocopherol in plasma (1.13 v. 0.67 mg/l; P<0.001) and selenium in whole blood (0.12 v. 0.07 mg/l; P<0.01) of the ewes at lambing compared with controls. Supplementation also increased the concentration of α-tocopherol (0.14 v. 0.08 mg/l; P<0.001) and selenium (0.08 v. 0.05 mg/l; P<0.01) in lambs at birth compared with controls. There was no significant effect of supplementation on immune function or

Mining-Related Selenium Contamination in Alaska, and the State of Current Knowledge

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Aibyek Khamkhash

2017-03-01

Full Text Available Selenium pollution has been a topic of extensive research dating back further than the last decade and has attracted significant attention from several environmental and regulatory agencies in order to monitor and control its discharge from myriad industrial sources. The mining industry is a prime contributor of hazardous selenium release in the aquatic systems and is responsible for both acute and chronic impacts on living organisms. Herein we provide an overview of selenium contamination issues, with a specific focus on selenium release from mining industries, including a discussion of various technologies commonly employed to treat selenium-impacted waters from mining discharge. Different cases pertaining to selenium release from Alaskan mines (during years 2000–2015 are also presented, along with measures taken to mitigate high concentration releases. For continued resource exploration and economic development activities, as well as environmental preservation, it is important to fundamentally understand such emerging and pressing issues as selenium contamination and investigate efficient technological approaches to counter these challenges.

Serum selenium levels and the risk of progression of laryngeal cancer.

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Lubiński, Jan; Marciniak, Wojciech; Muszynska, Magdalena; Jaworowska, Ewa; Sulikowski, Mieczyslaw; Jakubowska, Anna; Kaczmarek, Katarzyna; Sukiennicki, Grzegorz; Falco, Michal; Baszuk, Piotr; Mojsiewicz, Magdalena; Kotsopoulos, Joanne; Sun, Ping; Narod, Steven A; Lubiński, Jan A

2018-01-01

Observational studies have reported an inverse relationship between selenium status (blood or toenail) and the risk of laryngeal cancer; however, the impact of low serum selenium level on survival has not been evaluated. We conducted a prospective study of 296 patients diagnosed with laryngeal cancer in Szczecin, Poland. Serum selenium was measured at diagnosis and prior to treatment. Patients were followed from the date of diagnosis to death at five years. Vital status was obtained by linkage to the Polish National Death Registry. The five-year survival after diagnosis was 82.0% (95% CI: 68% to 91%) for individuals in the highest quartile of serum selenium (> 66.8 μg/L) and was 28.6% (95% CI 19% to 42%) for individuals in the lowest quartile (selenium, compared to those in the highest quartile. The corresponding multivariate HR was 3.07 (95% CI 1.59 to 5.94). This study suggests that a selenium level in excess of 70 μg/L is associated with improved outcome among patients undergoing treatment for laryngeal cancer. Further studies are needed to evaluate if selenium supplementation to achieve this level might improve overall prognosis.

The effect of newer water-soluble contrast media on I-131 uptake by the thyroid gland

International Nuclear Information System (INIS)

Starinsky, R.; Horne, T.; Barr, J.; Ramot, Y.

2006-01-01

The aim of this study was to evaluate the effect of two water-soluble contrast media (nonionic and Dimer) on iodine uptake by the thyroid gland. Twenty-eight euthyroid patients (16 females and 12 males) were subjected to 24hrs radioiodine uptake (RAIU) studies following brain CT examinations using the above cited two water-soluble contrast media. Radioiodine uptake studies were done at one (Group-1), two (Group-2) and four (Group-3) weeks following performance of contrast enhanced CT scans. The effect of both contrast media on the thyroid uptake was found to be identical. The radio active iodine uptake (RAIU) was observed to be suppressed in 30% of patients in Group-1, 33% of patients in Group-2 and in none of the patients belonging to Group-3. On the basis of this pilot study on a limited number of patients it was concluded that dimer and non-ionic water soluble contrast media cause suppression of radio iodine uptake by the thyroid gland in a significant proportion of patients. It has also been observed that both contrast media have similar suppressive effects on radio iodine uptake by the thyroid gland. This effect is transient and does not persist beyond a period of four weeks following the administration of the contrast media. (author)

Selenium content of tissues in Finnish infants and adults with various diseases, and studies on the effects of selenium supplementation in neuronal ceroid lipofuscinosis patients

International Nuclear Information System (INIS)

Westermarck, T.

1977-01-01

A low blood selenium level has previously been observed in healthy inhabitants of Finland. In this study even lower blood selenium values were observed in patients with acrodermatitis enteropathica, dystrophia musculorum progressiva (Duchenne), infantile and juvenile type of neuronal ceroid lipofuscinosis (NCL), severe mental retardation caused by various factors, and myocardial infarction. The selenium content of the brain, heart, kidney and liver in patients of different ages was also determined. The highest selenium level was found in the kidney. The mean liver selenium concentrations in stillborn, premature and full-term neonates were 1.11 plus minus 0.23 (8), 1.21 plus minus 0.17 (12) and 0.93 plus minus 0.16 μg/g dry weight (12) respectively (the number of subjects in parentheses). The selenium values are considerably higher than those in infants of from one to nine months of age and adults, whose liver selenium values were 0.58 plus minus 0.21 (8) and 0.67 plus minus 0.08 μg/g dry weight (8) respectively. The vitamin E levels of serum in patients with NCL, as well as in subjects with severe mental retardation (controls), were low compared with values in healthy normal subjects. Sodium selenite supplementation in patients with NCL produced at least a transitory improvement without causing any toxic effects during one year of administration. (author)

Enhanced Iron and Selenium Uptake in Plants by Volatile Emissions of Bacillus amyloliquefaciens (BF06

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Jianfei Wang

2017-01-01

Full Text Available Volatile organic compounds (VOCs released by plant growth-promoting rhizobacteria (PGPR are involved in promoting growth and triggering systemic resistance (ISR in plants. Importantly, the release of VOCs by some PGPR strains confers improved plant uptake of nutrient elements from the soil. However, the underlying mechanisms of VOCs-regulated nutrient acquisition remain elusive. In this study, VOCs were extracted and identified from Bacillus amyloliquefaciens (strain BF06 using gas chromatography–mass spectrometry (GC–MS. BF06 VOCs exposure significantly promoted the growth and photosynthesis of Arabidopsis plants. To explore how microbial VOCs stimulate growth in plants, gene expression profiles of Arabidopsis seedlings exposed to BF06 VOCs were examined using transcriptomic analyses. In screening differentially expressed genes (DEGs, most upregulated DEGs were found to be related to amino acid transport, iron (Fe uptake and homeostasis, and sulfate transport. Furthermore, BF06 VOCs significantly enhanced Fe absorption in plants under Fe-limited conditions. However, when nitric oxide (NO synthesis was inhibited, BF06 VOCs exposure could not substantially augment Fe acquisition in plants under alkaline stress, indicating that VOCs-mediated plant uptake of Fe was required for induction of root NO accumulation. In addition, BF06 VOCs exposure led to a marked increase in some genes encoding for sulfate transporters, and further increased Se accumulation in plants. Intriguingly, BF06 VOCs exposure failed to increase Se uptake in sultr1;2 mutants, which may indicate that high-level transcription of these sulfate transporters induced by BF06 VOCs was essential for enhancing Se absorption by plants. Taken together, our results demonstrated the potential of VOCs released by this strain BF06 to increase Fe and Se uptake in plants.

The Thermodynamics of Selenium Minerals in Near-Surface Environments

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Vladimir Krivovichev

2017-10-01

Full Text Available Selenium compounds are relatively rare as minerals; there are presently only 118 known mineral species. This work is intended to codify and systematize the data of mineral systems and the thermodynamics of selenium minerals, which are unstable (selenides or formed in near-surface environments (selenites, where the behavior of selenium is controlled by variations of the redox potential and the acidity of solutions at low temperatures and pressures. These parameters determine the migration of selenium and its precipitation as various solid phases. All selenium minerals are divided into four groups—native selenium, oxide, selenides, and oxysalts—anhydrous selenites (I and hydrous selenites and selenates (II. Within each of the groups, minerals are codified according to the minimum number of independent elements necessary to define the composition of the mineral system. Eh–pH diagrams were calculated and plotted using the Geochemist’s Workbench (GMB 9.0 software package. The Eh–pH diagrams of the Me–Se–H2O systems (where Me = Co, Ni, Fe, Cu, Pb, Zn, Cd, Hg, Ag, Bi, As, Sb, Al and Ca were plotted for the average contents of these elements in acidic waters in the oxidation zones of sulfide deposits. The possibility of the formation of Zn, Cd, Ag and Hg selenites under natural oxidation conditions in near surface environments is discussed.

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

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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.

Selenium transformation in coal mine spoils: Its environmental impact assessment

Energy Technology Data Exchange (ETDEWEB)

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

1991-12-31

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

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

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

2009-01-01

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

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

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Doucha Jiří

2009-05-01

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

Removal of Selenium and Nitrate in Groundwater Using Organic Carbon-Based Reactive Mixtures

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An, Hyeonsil; Jeen, Sung-Wook

2016-04-01

Treatment of selenium and nitrate in groundwater was evaluated through column experiments. Four columns consisting of reactive mixtures, either organic carbon-limestone (OC-LS) or organic carbon-zero valent iron (OC-ZVI), were used to determine the removal efficiency of selenium with different concentrations of nitrate. The source waters were collected from a mine site in Korea or were prepared artificially based on the mine drainage water or deionized water, followed by spiking of elevated concentrations of Se (40 mg/L) and nitrate (100 or 10 mg/L as NO3-N). The results for the aqueous chemistry showed that selenium and nitrate were effectively removed both in the mine drainage water and deionized water-based artificial input solution. However, the removal of selenium was delayed when selenium and nitrate coexisted in the OC-LS columns. The removal of selenium was not significant when the influent nitrate concentration was 100 mg/L as NO3-N, while most of nitrate was gradually removed within the columns. In contrast, 94% of selenium was removed when the influent nitrate concentration was reduced to 10 mg/L as NO3-N. In the OC-ZVI column, selenium and nitrate was removed almost simultaneously and completely even with the high nitrate concentration; however, a high concentration of ammonia was produced as a by-product of abiotic reaction between ZVI and nitrate. The elemental analysis for the solid samples after the termination of the experiments showed that selenium was accumulated in the reactive materials where removal of aqueous-phase selenium mostly occurred. The X-ray absorption near-edge structure (XANES) study indicated that selenium existed in the forms of SeS2 and Se(0) in the OC-LS column, while selenium was present in the forms of FeSe, SeS2 and absorbed Se(IV) in the OC-ZVI column. This study shows that OC-based reactive mixtures have an ability to remove selenium and nitrate in groundwater. However, the removal of selenium was influenced by the high

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

International Nuclear Information System (INIS)

Ho, S.Y.

1981-01-01

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

Selenium containing clays minerals as additive for the discoloration of glass

NARCIS (Netherlands)

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

2010-01-01

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

Designing the selenium and bladder cancer trial (SELEBLAT, a phase lll randomized chemoprevention study with selenium on recurrence of bladder cancer in Belgium

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Goossens Maria E

2012-03-01

Full Text Available Abstract Background In Belgium, bladder cancer is the fifth most common cancer in males (5.2% and the sixth most frequent cause of death from cancer in males (3.8%. Previous epidemiological studies have consistently reported that selenium concentrations were inversely associated with the risk of bladder cancer. This suggests that selenium may also be suitable for chemoprevention of recurrence. Method The SELEBLAT study opened in September 2009 and is still recruiting all patients with non-invasive transitional cell carcinoma of the bladder on TURB operation in 15 Belgian hospitals. Recruitment progress can be monitored live at http://www.seleblat.org. Patients are randomly assigned to selenium yeast (200 μg/day supplementation for 3 years or matching placebo, in addition to standard care. The objective is to determine the effect of selenium on the recurrence of bladder cancer. Randomization is stratified by treatment centre. A computerized algorithm randomly assigns the patients to a treatment arm. All study personnel and participants are blinded to treatment assignment for the duration of the study. Design The SELEnium and BLAdder cancer Trial (SELEBLAT is a phase III randomized, placebo-controlled, academic, double-blind superior trial. Discussion This is the first report on a selenium randomized trial in bladder cancer patients. Trial registration ClinicalTrials.gov identifier: NCT00729287

Ecologic study of serum selenium and upper gastrointestinal cancers in Iran.

Science.gov (United States)

Nouarie, Mehdi; Pourshams, Akram; Kamangar, Farin; Sotoudeh, Masood; Derakhshan, Mohammad Hossein; Akbari, Mohammad Reza; Fakheri, Hafez; Zahedi, Mohammad Javad; Caldwell, Kathleen; Abnet, Christian C; Taylor, Philip R; Malekzadeh, Reza; Dawsey, Sanford M

2004-09-01

Both observational and experimental studies have shown that higher selenium status reduces the risk of upper gastrointestinal cancers in selenium deficient populations. Recent cancer registry data have shown very different rates of esophageal cancer (EC) and gastric cancer (GC) in four Provinces of Iran, namely Ardabil, Mazandaran, Golestan, and Kerman. The aim of this study was to have a preliminary assessment of the hypothesis that high rates of EC in Golestan and high rates of GC in Ardabil may be partly attributable to selenium deficiency. We measured serum selenium in 300 healthy adults from Ardabil (n = 100), Mazandaran (n = 50), Golestan (n = 100), and Kerman (n = 50), using inductively coupled plasma, with dynamic reaction cell, mass spectrometry (ICP-DRC-MS) at the US Centers for Disease Control (Atlanta, Georgia). The median serum selenium concentrations were very different in the four Provinces. The medians (IQR) for selenium in Ardabil, Mazandarn, Golestan, and Kerman were 82 (75-94), 123 (111-132), 155 (141-173), and 119 (110-128) microg/L, respectively (P<0.001). The results of linear regression showed that the Province variable, by itself, explained 76% of the variance in log selenium (r2 = 0.76). The proportion of the populations with a serum selenium more than 90 microg/L (the concentration at which serum selenoproteins are saturated) was 100% in Golestan, Kerman, and Mazandaran but only 29% in Ardabil. Our findings suggest that selenium deficiency is not a major contributor to the high incidence of EC seen in northeastern Iran, but it may play a role in the high incidence of GC in Ardabil Province. Copyright 2004 The WJG Press ISSN

Plasma and breast-milk selenium in HIV-infected Malawian mothers are positively associated with infant selenium status but are not associated with maternal supplementation: results of the Breastfeeding, Antiretrovirals, and Nutrition study.

Science.gov (United States)

Flax, Valerie L; Bentley, Margaret E; Combs, Gerald F; Chasela, Charles S; Kayira, Dumbani; Tegha, Gerald; Kamwendo, Debbie; Daza, Eric J; Fokar, Ali; Kourtis, Athena P; Jamieson, Denise J; van der Horst, Charles M; Adair, Linda S

2014-04-01

Selenium is found in soils and is essential for human antioxidant defense and immune function. In Malawi, low soil selenium and dietary intakes coupled with low plasma selenium concentrations in HIV infection could have negative consequences for the health of HIV-infected mothers and their exclusively breastfed infants. We tested the effects of lipid-based nutrient supplements (LNS) that contained 1.3 times the Recommended Dietary Allowance of sodium selenite and antiretroviral drugs (ARV) on maternal plasma and breast-milk selenium concentrations. HIV-infected Malawian mothers in the Breastfeeding, Antiretrovirals, and Nutrition study were randomly assigned at delivery to receive: LNS, ARV, LNS and ARV, or a control. In a subsample of 526 mothers and their uninfected infants, we measured plasma and breast-milk selenium concentrations at 2 or 6 (depending on the availability of infant samples) and 24 wk postpartum. Overall, mean (± SD) maternal (range: 81.2 ± 20.4 to 86.2 ± 19.9 μg/L) and infant (55.6 ± 16.3 to 61.0 ± 15.4 μg/L) plasma selenium concentrations increased, whereas breast-milk selenium concentrations declined (14.3 ± 11.5 to 9.8 ± 7.3 μg/L) from 2 or 6 to 24 wk postpartum (all P milk selenium from 2 or 6 to 24 wk postpartum (both P milk selenium, but maternal selenium concentrations were positively associated with infant plasma selenium at 2 or 6 and 24 wk postpartum (P milk selenium concentrations. Future research should examine effects of more readily incorporated forms of selenium (ie, selenomethionine) in HIV-infected breastfeeding women.

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

Czech Academy of Sciences Publication Activity Database

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

2007-01-01

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

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

Science.gov (United States)

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

2014-08-01

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

Use of sodium hydroxide treated selenium deficient barley to induce vitamin E and selenium deficiency in yearling cattle.

Science.gov (United States)

Rice, D A; McMurray, C H

1986-02-15

Selenium deficient barley grown in Northern Ireland was treated with sodium hydroxide to deplete it of vitamin E. Housed cattle fed a complete diet based on this treated barley developed nutritional degenerative myopathy, showing that spontaneous myopathy in yearling cattle can be the result of vitamin E and selenium deficiency alone. The diet used is as effective and cheaper than others presently in use for inducing degenerative myopathy.

Loss of selenium in drying and storage of agronomic plant species

DEFF Research Database (Denmark)

Nielsen, Gunnar Gissel

1970-01-01

In two experiments with Se75, loss of selenium from agricultural species was noted during both drying and storage. The loss of selenium during drying was to some extent overshadowed by the influence of self-absorption caused by the water in the fresh material. The results showed that even plant...... material of non-indicator plantslose volatile selenium at drying temperatures of 60°C or higher, and in some cases even at temperatures below 60°C. The results also showed that storage as briquettes gives the lowest storage loss of selenium....

Comparison of Selenium Toxicity in Sunflower and Maize Seedlings Grown in Hydroponic Cultures.

Science.gov (United States)

Garousi, Farzaneh; Veres, Szilvia; Kovács, Béla

2016-11-01

Several studies have demonstrated that selenium (Se) at low concentrations is beneficial, whereas high Se concentrations can induce toxicity. Controlling Se uptake, metabolism, translocation and accumulation in plants is important to decrease potential health risks and helping to select proper biofortification methods to improve the nutritional content of plant-based foods. The uptake and distribution of Se, changes in Se content, and effects of various concentrations of Se in two forms (sodium selenite and sodium selenate) on sunflower and maize plants were measured in nutrient solution experiments. Results revealed the Se content in shoots and roots of both sunflower and maize plants significantly increased as the Se level increased. In this study, the highest exposure concentrations (30 and 90 mg/L, respectively) caused toxicity in both sunflower and maize. While both Se forms damaged and inhibited plant growth, each behaved differently, as toxicity due to selenite was observed more than in the selenate treatments. Sunflower demonstrated a high Se accumulation capacity, with higher translocation of selenate from roots to shoots compared with selenite. Since in seleniferous soils, a high change in plants' capability exists to uptake Se from these soils and also most of the cultivated crop plants have a bit tolerance to high Se levels, distinction of plants with different Se tolerance is important. This study has tried to discuss about it.

Association between Toenail Mercury and Metabolic Syndrome Is Modified by Selenium

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Kyong Park

2016-07-01

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

Inter-individual variation of selenium in maternal plasma, cord plasma and placenta

International Nuclear Information System (INIS)

Lee, Anne M.; Huel, Guy; Godin, Jean; Hellier, Georgette; Sahuquillo, Josiane; Moreau, Thierry; Blot, Phillipe

1994-01-01

Selenium (Se) in high doses has been known to cause injury to the fetus and newborn. The major difficulty in assessing the effects of selenium on human reproduction stems from the need for a suitable means of estimating maternal and fetal exposure. The present investigation, therefore, examines the respective reliability of maternal plasma, cord plasma and placenta as epidemiological indicators as well as inter-individual variation of this trace element. An unselected population of 128 pregnancies was studied. Obstetrical characteristics were noted. Selenium concentrations were determined for maternal plasma, cord plasma, and placental tissue by fluorometric analysis. Maternal plasma selenium concentrations (Se-Bm) were significantly greater than fetal concentrations (Se-Bc). Placental selenium (Se-Pl) levels were four times that of fetal levels. Variability of Se-Bc is best explained by placental concentrations. Maternal weight and ethnic origin are significantly correlated with Se-Bc. Female newborn have higher selenium levels than male newborn. The present study demonstrates the significance of the placenta as an indicator of fetal selenium exposure

Preparation and characterization of a laboratory scale selenomethionine-enriched bread. Selenium bioaccessibility.

Science.gov (United States)

Sánchez-Martínez, María; Pérez-Corona, Teresa; Caímara, Carmen; Madrid, Yolanda

2015-01-14

This study focuses on the preparation at lab scale of selenomethionine-enriched white and wholemeal bread. Selenium was supplemented either by adding selenite directly to the dough or by using lab-made selenium-enriched yeast. The best results were obtained when using fresh selenium-enriched yeast. The optimum incubation time for selenomethionine-enriched yeast preparation, while keeping formation of selenium byproducts to a minimum, was 96 h. Selenium content measured by isotope dilution analysis (IDA)-ICP-MS in Se-white and Se-wholemeal bread was 1.28 ± 0.02 μg g–1 and 1.16 ± 0.02 μg g–1 (expressed as mean ± SE, 3 replicates), respectively. HPLC postcolumn IDA-ICP-MS measurements revealed that selenomethionine was the main Se species found in Se-enriched bread, which accounted for ca. 80% of total selenium. In vitro gastrointestinal digestion assay provided selenium bioaccessibility values of 100 ± 3% and 40 ± 1% for white and wholemeal Se-enriched bread, respectively, being selenomethionine the main bioaccessible Se species in white bread, while in wholemeal bread this compound was undetectable.

Recent Microextraction Techniques for Determination and Chemical Speciation of Selenium

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Ibrahim Ahmed S. A.

2017-05-01

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

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

Science.gov (United States)

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

Selenium status and cancer mortality in subjects residing in four Canadian provinces

International Nuclear Information System (INIS)

Morris, J.S.; Horsman, T.L.; Spate, V.L.; Baskett, C.K.; Mason, M.M.; Nichols, T.A.; Rohan, T.; Soskolne, C.L.; Jain, M.

2001-01-01

Selenium status in male and female Canadian subjects was measured relative to cancer mortality in their respective provinces. Toenail specimens from 755 subjects, 377 males and 378 females, living in Vancouver (186), Edmonton (188), Toronto (197) and Montreal (184) were analyzed by instrumental neutron activation analysis giving means of 0.968 ± 0.177, 0.950 ± 0.148, 0.932 ± 0.135 and 0.896 ± 0.127 ppm Se, respectively. The effect of selenium determinants such as gender, selenium supplementation and smoking on selenium status is presented. Details of the observed inverse relationship of selenium status and cancer mortality are discussed. (author)

Characterization of selenium doped silica glasses synthesized by sol-gel method

International Nuclear Information System (INIS)

Kobayashi, R.A.; Toffoli, S.M.

2012-01-01

Selenium is a rare element in nature. It is used in the food, pharmaceutical, and glass industries. In commercial glasses, selenium is the element responsible for most of the pink or light red color, but its effect is primarily dependent on the oxidation state of the element in the glassy matrix. Besides, selenium is highly volatile, and as high as 80 wt% may be lost in the furnace during the industrial glass elaboration. The sol– gel method yields synthesized materials of high purity and homogeneity, and uses low processing temperatures. Samples of silica glass were obtained by sol-gel method, incorporating precursors of selenium, with the main objective of reducing selenium losses during its heating. The results of optical absorption, XRD and thermal analysis (TGA, DSC) of the glasses are presented and discussed. (author)

Selenium in the Blackfoot, Salt, and Bear River Watersheds

Science.gov (United States)

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

2005-01-01

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

Selenium Treatment Technologies

Science.gov (United States)

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

Effect of selenium on malignant tumor cells of brain.

Science.gov (United States)

Zhu, Z; Kimura, M; Itokawa, Y; Nakatsu, S; Oda, Y; Kikuchi, H

1995-07-01

Some reports have demonstrated that selenium can inhibit tumorigenesis in some tissues of animal. However, little is known about the inhibitory effect on malignant tumor cells of brain. The purpose of our study was to determine the biological effect of selenium on growth of rat glioma and human glioblastoma cell lines. Cell lines C6 and A172 were obtained from Japanese Cancer Research Resources Bank, Tokyo, Japan (JCRB). Cells were cultured in Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% fetal calf serum at 37 degrees C in a humidified atmosphere of air and 5% CO2. Antiproliferative effects of selenium were evaluated using growth rate assay quantifying cell number by MTT assay. An antiproliferative effect of selenium was found in two cell lines, which was more effective on human A172 glioblastoma and less effective on rat C6 glioma.

Radiation protection effect of selenium on the Rat's prostate

Energy Technology Data Exchange (ETDEWEB)

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

2017-06-15

High-tech medical equipment has increased the utilization of radiation in the medical field. As a result, research on radiation protection using natural materials has become an important social issue. Selenium is a natural substance that is highly expressed in prostate known that an essential role in prostate cells. Selenium was orally administered to Rat and irradiated with 10 Gy of radiation. Then, the prostate tissue was used as a target organ for 1 day, 7 days and 21 days to investigate the radiation protection effect of selenium through changes of blood components, Superoxide Dismutase and histological changes. As a result, there was a significant protective effect of hematopoietic immune system(hemoglobin concentration, neutrophil, platelet) in the group irradiated with selenium(p<0.05). The observation of tissue changes selenium is an effective component to increase Superoxide Dismutase activity, and it was confirmed that it has an effect of inhibiting the expression of hypertrophy of prostate by irradiation. Therefore, it is considered that selenium can be utilized as a radioprotective agent by inducing prevention of prostate-related diseases.

EFFECT OF SELENIUM SUPPLEMENTATION ON PIG PRODUCTION PROPERTIES, ANTIOXIDANT STATUS AND MEAT QUALITY

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Tomislav Šperanda

2013-12-01

Full Text Available Food containing functional ingredients to achieve a positive effect on health and reducing the risk of infection is increasing production. It is also very important to improve the quality of pork with respect to change the genetic makeup of pigs that raised leanness, being inversely correlated with the quality of meat. This study monitored the effectiveness of addition of higher doses of organic selenium in the diet of fattening pigs in relation to their growth, immunity, antioxidant power, the quality of meat and possibility of meat enriching with selenium. The experiment was carried out on 100 pigs (crossbred WJxSLxP of both sexes, from 28 kg to 98 kg body weight during a period of 98 days. Piglets fed the finished feed mixture for fattening up to 60 kg (ST-1 and a mixture for fattening up to 100 kg (DM-2 in addition, by the groups as follows: K-0. 3 mg/kg organic selenium, P1-0.5 mg/kg inorganic selenium, P2-0.5 mg/kg organic selenium, P3-0.5 mg/ kg organic selenium +0.2% zeolite clinoptilolite treated vibrotehnology and P4-gradual increase in selenium so that the concentration of the last month was 0.7 mg/ kg diet of organic selenium. All groups of pigs fed high concentration of organic selenium had a higher proportion of lymphocytes, especially CD4 T lymphocytes. Glutathione peroxidase activity was higher in all groups fed elevated selenium levels and significantly higher in the P3 and P4 groups 71st and 98th days of the trials. Glutathione reductase was significantly higher in the P3 and P4 group 98th days compared to the control. Antioxidant indicators suggested increased antioxidant protection in groups supplemented with 0.5 ppm organic selenium and selenium formulations of the same with the addition of zeolite under stress intensive pig production. No differences were found in the products of lipid peroxidation (TBARS in raw meat or in meat after a week in refrigerator storage. By histological examination statistically higher level of

Total selenium in irrigation drain inflows to the Salton Sea, California, April 2009

Science.gov (United States)

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

2009-01-01

This report presents the results for the final sampling period (April 2009) of a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium and total suspended solids were determined in water samples. Total selenium, percent total organic carbon, and particle size were determined in sediments. Mean total selenium concentrations in water ranged from 0.98 to 22.9 micrograms per liter. Total selenium concentrations in sediment ranged from 0.078 to 5.0 micrograms per gram dry weight.

Effects on the accumulation of calcium, magnesium, iron, manganese, copper and zinc of adding the two inorganic forms of selenium to solution cultures of Zea mays.

Science.gov (United States)

Longchamp, M; Angeli, N; Castrec-Rouelle, M

2016-01-01

The addition of selenate or selenite to common fertilizers for crop production could be an effective way of producing selenium-rich food and feed. However, this would be feasible only if the increase in plant selenium (Se) content did not negatively influence the uptake of other essential elements. We therefore need to understand the interactions between Se and other major and trace elements during uptake by the plant. This study aimed to evaluate the influence of inorganic forms of Se on the accumulation of selected macronutrients (Ca and Mg) and micronutrients (Fe, Zn, Mn and Cu). Those essential elements are involved in the oxidative balance of cells. Zea mays seedlings were grown hydroponically in growth chambers in nutrient solutions to which we added 10, 50 or 1000 μg.L(-1) of selenate and/or selenite. Cation accumulation was significantly affected by the addition of 50 μg.L(-1) or 1000 μg.L(-1) Se, but not by the presence of 10 μg.L(-1) of Se in the nutrient solution. The highest concentration (1000 μg.L(-1)) of Se in the nutrient solution affected the accumulation of essential cations in Zea mays: selenate tended to increase the accumulation of Mg, Zn and Mn, whereas a selenate/selenite mixture tended to decrease the accumulation of Ca, Mg, Zn and Mn. Only Fe accumulation was unaffected by Se whatever its form or concentration. Selenium may also affect the distribution of cations on Zea mays. For example, levels of Mg and Zn translocation to the shoots were lower in the presence of selenite. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Shape coexistence in selenium isotopes

International Nuclear Information System (INIS)

Liu Ying; Cao Zhongbin; Xu Furong

2010-01-01

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

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

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Sougat Misra

2015-05-01

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

Selenite -Se(4)- uptake mechanisms in the unicellular green alga Chlamydomonas reinhardtii: bioaccumulation and effects induced on growth and ultrastructure

International Nuclear Information System (INIS)

Morlon, H.

2005-03-01

Selenium is an essential element, but becomes very toxic at higher concentrations. It occurs in the environment at concentrations ranging from nM to μM and selenium pollution is a worldwide phenomenon. This works aims at improving the knowledge on the interactions between selenite - Se(IV) - and a freshwater phyto-planktonic organism: the unicellular green algae Chlamydomonas reinhardtii. The aim of the performed experiments were: i) to investigate selenite -Se(IV)- uptake mechanisms in C. reinhardtii, using Se 75 as a tracer in short term exposures ( -2 .nM -1 .h -1 . The uptake was proportional to ambient levels in a broad range of intermediate concentrations (from nM to μM). However, fluxes were higher at very low concentrations ( μM), suggesting that a high affinity but rapidly saturated transport mechanism could be used at low concentrations, in parallel with a low affinity mechanism that would only saturate at high concentrations (∼mM). The latter could involve transporters used by sulphate and nitrates, as suggested by the inhibition of selenite uptake by those element. Se(IV) speciation changes with pH did not induce significant effect on bioavailability. On the basis of the relationship between Se concentration and maximal cell density achieved, an EC50 of 80 μM ([64; 98]) was derived. No adaptation mechanism were observed as the same the same toxicity was quantified for Se-pre-exposed algae. Observations by TEM suggested chloroplasts as the first target of selenite cytotoxicity, with effects on the stroma, thylakoids and pyrenoids. At higher concentrations, we could observe an increase in the number and volume of starch grains. For the cell collected at 96 h, electron-dense granules were observed. Energy-dispersive X-ray microanalysis revealed that they contained selenium and were also rich in calcium and phosphorus. Finally, growth inhibition was highly correlated to the bioaccumulation of selenite. The latter was inhibited by increasing

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

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Marek Kieliszek

2017-02-01

Full Text Available 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 Se4+∙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 Se4+∙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 Se4+∙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

Selenium supplementation for Hashimoto's thyroiditis.

Science.gov (United States)

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

2013-06-06

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

Responses of Portulaca oleracea Linn. to selenium exposure.

Science.gov (United States)

Prabha, D; Sivakumar, S; Subbhuraam, C V; Son, H K

2015-05-01

The present study was investigated to evaluate the uptake and accumulation of selenium (Se) by the stem cuttings of Portulaca oleracea L. grown in alfisol amended with various concentrations of Se. P. oleracea accumulated a maximum of 63.4 µg g(-1) dry weight in a short growth period of 42 days. The order of accumulation of Se among the plant parts was leaves (31.5 μg g(-1)) > stems (16.4 μg g(-1)) > roots (15.5 μg g(-1)). The accumulation potential was fourfold higher than the plant available concentration of 15.2 μg g(-1) of Se g(-1) of soil (diethylenetriaminepentaacetic acid extracted). Although the plant was able to accumulate Se in their tissues, increase in Se concentrations in soil caused a concentration-dependent decrease in the growth rate of plants (regeneration of leaves, number of leaves, number of roots, root length, stem length and biomass). © The Author(s) 2013.

Microgravimetric Studies of Selenium Electrodeposition Onto Different Substrates

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Kowalik R.

2014-10-01

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

Selenium Poisoning of Wildlife and Western Agriculture: Cause and Effect

Energy Technology Data Exchange (ETDEWEB)

Korte, N.E.

2000-02-01

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

21 CFR 522.2100 - Selenium, vitamin E injection.

Science.gov (United States)

2010-04-01

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

Identification and characterization of a selenium-dependent glutathione peroxidase in Setaria cervi

International Nuclear Information System (INIS)

Singh, Anchal; Rathaur, Sushma

2005-01-01

Setaria cervi a bovine filarial parasite secretes selenium glutathione peroxidase during in vitro cultivation. A significant amount of enzyme activity was detected in the somatic extract of different developmental stages of the parasite. Among different stages, microfilariae showed a higher level of selenium glutathione peroxidase activity followed by males then females. However, when the activity was compared in excretory secretory products of these stages males showed higher activity than microfilariae and female worms. The enzyme was purified from female somatic extract using a combination of glutathione agarose and gel filtration chromatography, which migrated as a single band of molecular mass ∼20 kDa. Selenium content of purified enzyme was estimated by atomic absorption spectroscopy and found to be 3.5 ng selenium/μg of protein. Further, inhibition of enzyme activity by potassium cyanide suggested the presence of selenium at the active site of enzyme. This is the first report of identification of selenium glutathione peroxidase from any filarial parasite

Selenium and tellurium reagents in organic synthesis

International Nuclear Information System (INIS)

Comasseto, J.V.

1984-01-01

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

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

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Arlindo Saran Netto

2013-01-01

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

Preliminary study of daily selenium level intake in algeria

International Nuclear Information System (INIS)

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

1992-10-01

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

Distribution and retention of inhaled selenium compounds in the rat

International Nuclear Information System (INIS)

Burkstaller, M.A.; Cuddihy, R.G.

1978-01-01

Selenium containing compounds released into the atmosphere during coal combustion are principally of the elemental form or the dioxide. These compounds differ greatly in their chemical properties. Fischer-344 rats were exposed via inhalation to both the dioxide and the red elemental form of selenium. Subsequently, measurements were made of internal absorption, organ distribution and retention, and modes of excretion. A radiotracer, 75 Se, was incorporated into the aerosol to facilitate these measurements. Retention of both aerosols in the total body showed long term components with half lives of 43 and 15 days accounting for 25 to 35% of the initially deposited selenium. Excretion occurred principally by way of urine. For both aerosols, selenium absorbed into the systemic circulation was mainly found in the liver, kidney, blood, gastrointestinal tract and bone

21 CFR 520.2100 - Selenium, vitamin E capsules.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Selenium, vitamin E capsules. 520.2100 Section 520... to 1 milligram of selenium) and 56.2 milligrams of vitamin E (68 I.U.) (as d-alpha tocopheryl acid... of vitamin E (17 I.U.) (as d-alpha tocopheryl acid succinate.) (b) Sponsor. See No. 000061 in § 510...

Comparison of pre-treatment and post-treatment use of selenium in retinal ischemia reperfusion injury

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Alper Yazici

2015-04-01

Full Text Available AIM: To investigate the effects of selenium in rat retinal ischemia reperfusion (IR model and compare pre-treatment and post-treatment use. METHODS: Selenium pre-treatment group (n=8 was treated with intraperitoneal (i.p. selenium 0.5 mg/kg for 7d and terminated 24h after the IR injury. Selenium post-treatment group (n=8 was treated with i.p. selenium 0.5 mg/kg for 7d after the IR injury with termination at the end of the 7d period. Sham group (n=8 received i.p. saline injections identical to the selenium volume for 7d with termination 24h after the IR injury. Control group (n=8 received no intervention. Main outcome measures were retina superoxide dismutase (SOD, glutathione (GSH, total antioxidant status (TAS, malondialdehyde (MDA, DNA fragmentation levels, and immunohistological apoptosis evaluation. RESULTS: Compared to the Sham group, selenium pre-treatment had a statistical difference in all parameters except SOD. Post-treatment selenium also resulted in statistical differences in all parameters except the MDA levels. When comparing selenium groups, the pre-treatment selenium group had a statistically higher success in reduction of markers of cell damage such as MDA and DNA fragmentation. In contrast, the post-selenium treatment group had resulted in statistically higher levels of GSH. Histologically both selenium groups succeeded to limit retinal thickening and apoptosis. Pre-treatment use was statistically more successful in decreasing apoptosis in ganglion cell layer compared to post-treatment use. CONCLUSION: Selenium was successful in retinal protection in IR injuries. Pre-treatment efficacy was superior in terms of prevention of tissue damage and apoptosis.

Influence of Selenium on the Production of T-2 Toxin by Fusarium poae.

Science.gov (United States)

Cheng, Bolun; Zhang, Yan; Tong, Bei; Yin, Hong

2017-07-01

The objective of this study was to investigate the effects of selenium on the production of T-2 toxin by a Fusarium poae strain cultured in a synthetic medium containing different concentrations of selenium. The T-2 toxin contents in fermentative products were evaluated by a high performance liquid chromatography (HPLC). The results showed that the production of T-2 toxin was correlated with the concentration of selenium added to the medium. In all three treatments, the addition of 1 mg/L selenium to the medium resulted in a lower toxin yield than the control (0 mg/L); the yield of the toxin began to increase when selenium concentration was 10 mg/L, while it decreased again at 20 mg/L. In summary, T-2 toxin yield in the fermentative product was affected by the addition of selenium to the medium, and a selenium concentration of 20 mg/L produced the maximum inhibitory effect of T-2 toxin yield in the fermentative product of F. poae.

Selenium recovery from kiln powder of cement manufacturing by chemical leaching and bioreduction.

Science.gov (United States)

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.

Selenium Enrichment of Horticultural Crops.

Science.gov (United States)

Puccinelli, Martina; Malorgio, Fernando; Pezzarossa, Beatrice

2017-06-04

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

Selenium Enrichment of Horticultural Crops

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Martina Puccinelli

2017-06-01

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

Determination of molybdenum and selenium in bioenvironmental samples using neutron activation analysis

International Nuclear Information System (INIS)

Abu-Samra, A.; Morris, J.S.; Koirtyohann, S.R.; Vogt, J.R.

1974-01-01

Because of the increasing interest as to their roles in biological systems, a procedure has been developed by which molybdenum and selenium can be determined at nanogram levels in these types of samples. Results from the analysis of orchard leaves and bovine liver are presented. The samples are packaged in pre-cleaned quartz vials prepared from GE-204 tubing. If both selenium and molybdenum are to be determined, the samples are irradiated for 40 or more hours at a thermal neutron flux of 8 x 10 13 n cm -2 sec -1 . After the samples have decayed for approximately 48 hours the vials are unpackaged, cleaned in aqua-regia, and broken. The irradiation period can be reduced to 24 hours if molybdenum is to be determined individually or if the selenium content is known to be 1 microgram or more. The sample is digested with carriers and the selenium is then distilled as a volatile selenium halide. Elemental selenium is precipitated by reduction with SO 2 produced through the protonation of the hydrogen sulfite ion and subsequent decomposition of the resulting sulfurous acid. The 401 keV summation peak of 75 Se is normally used for quantitative determination. The chemical yield is determined by drying and weighing the elemental selenium

Production of selenium-72 and arsenic-72

Science.gov (United States)

Phillips, D.R.

1994-12-06

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

Study of selenocompounds from selenium-enriched culture of edible sprouts.

Science.gov (United States)

Funes-Collado, Virginia; Morell-Garcia, Albert; Rubio, Roser; López-Sánchez, José Fermín

2013-12-15

Selenium is recognised as an essential micronutrient for humans and animals. One of the main sources of selenocompounds in the human diet is vegetables. Therefore, this study deals with the Se species present in different edible sprouts grown in Se-enriched media. We grew alfalfa, lentil and soy in a hydroponic system amended with soluble salts, containing the same proportion of Se, in the form of Se(VI) and Se(IV). Total Se in the sprouts was determined by acidic digestion in a microwave system and by ICP/MS. Se speciation was carried out by enzymatic extraction (Protease XIV) and measured by LC-ICP/MS. The study shows that the Se content of plants depends on the content in the growth culture, and that part of the inorganic Se was biotransformed mainly into SeMet. These results contribute to our understanding of the uptake of inorganic Se and its biotransformation by edible plants. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

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Huang Hui-Ying

2010-05-01

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

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

African Journals Online (AJOL)

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

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

African Journals Online (AJOL)

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

Removal of selenium species from waters using various surface-modified natural particles and waste materials

Energy Technology Data Exchange (ETDEWEB)

Yigit, Nevzat O.; Tozum, Seda [Department of Environmental Engineering, Suleyman Demirel University, Isparta (Turkey)

2012-07-15

Waste red mud and natural pumice/volcanic slag particles were surface modified and their selenium adsorption from waters was investigated. Acid activation/heat treatment of original red mud (ORM) particles significantly increased their micropore and external surface area and cumulative volume of pores. Iron oxide coating of pumice/slags and acid activation of ORM decreased their pH{sub pzc} values and increased surface acidity. Selenite/selenate adsorption on iron oxide surfaces and acid activated red mud (AARM) was very fast with approximately first-order adsorption kinetics. Iron oxide coating of pumice/slag and acid activation of ORM particles significantly enhanced their selenite and selenate uptakes. Maximum Se adsorption capacities as high as 6.3 (mg Se/g adsorbent) were obtained by AARM. The extent of selenate uptakes by the surface modified particles was generally lower than those of selenite. Due to competition among Se species and other background water matrix for iron oxide adsorption sites, reduced selenite/selenate uptakes were found in natural water compared to single solute tests. Higher Se uptakes by iron oxide surfaces were found at pH 7.5 compared to pH 8.9, due to increased electrostatic repulsion among iron oxides and Se species at higher pH. The most effective adsorbents among the tested 17 different particles for Se uptake were AARM and iron oxide coated pumice. Se concentrations less than drinking water standards (5-10 {mu}g/L) can be achieved by these particles. These low-cost, natural, or recyclable waste particles appear to be promising adsorbents for Se removal after their surface modification. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Effect of Se-enriched Organic Fertilizers on Selenium Accumulation in Corn and Soil

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LI Sheng-nan

2015-12-01

Full Text Available The effect of two Se-enriched organic fertilizers (cow dung and rice straw biochar on selenium accumulation of corn growing in selenium deficient soil was studied with pot experiment. The results showed that corn accumulated more selenium and the selenium was much easier to convert from root to shoot in the corn plant with the application of Se-enriched cow dung than Se-enriched rice straw biochar. With the application of more organic fertilizer such as 25 t·hm-2 Se-enriched cow dung or 40 t·hm-2 Se-enriched rice straw biochar, the accumulation of selenium and growth status of corn were getting better than the other treatments. At the same time, as the application amount of Se-enriched organic fertilizers (cow dung and rice straw biochar increased, the total selenium content in the soil also increased, which positively correlated with each other.

Selenium. Role of the Essential Metalloid in Health

Science.gov (United States)

Kurokawa, Suguru; Berry, Marla J.

2015-01-01

Selenium is an essential micronutrient in mammals, but is also recognized as toxic in excess. It is a non-metal with properties that are intermediate between the chalcogen elements sulfur and tellurium. Selenium exerts its biological functions through selenoproteins. Selenoproteins contain selenium in the form of the 21st amino acid, selenocysteine (Sec), which is an analog of cysteine with the sulfur-containing side chain replaced by a Se-containing side chain. Sec is encoded by the codon UGA, which is one of three termination codons for mRNA translation in non-selenoprotein genes. Recognition of the UGA codon as a Sec insertion site instead of stop requires a Sec insertion sequence (SECIS) element in selenoprotein mRNAs and a unique selenocysteyl-tRNA, both of which are recognized by specialized protein factors. Unlike the 20 standard amino acids, Sec is biosynthesized from serine on its tRNA. Twenty-five selenoproteins are encoded in the human genome. Most of the selenoprotein genes were discovered by bioinformatics approaches, searching for SECIS elements downstream of in-frame UGA codons. Sec has been described as having stronger nucleophilic and electrophilic properties than cysteine, and Sec is present in the catalytic site of all selenoenzymes. Most selenoproteins, whose functions are known, are involved in redox systems and signaling pathways. However, several selenoproteins are not well characterized in terms of their function. The selenium field has grown dramatically in the last few decades, and research on selenium biology is providing extensive new information regarding its importance for human health. PMID:24470102

AN ANALYTICAL METHOD FOR CHEMICAL SPECIATION OF SELENIUM IN SOIL

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Constantin Luca

2010-10-01

Full Text Available Selenium is an essential microelement, sometimes redoubtable, through its beneficial role - risk depending on its concentration in the food chain, at low dose is an important nutrient in the life of humans and animals, contrary at high doses, it becomes toxic. Selenium may be find itself in the environment (soil, sediment, water in many forms (oxidized, reduced, organometallic which determine their mobility and toxicity. Determination of chemical speciation (identification of different chemical forms provides much more complete information for a better understanding of the behavior and the potential impact on the environment. In this work we present the results of methodological research on the extraction of sequential forms of selenium in the soil and the coupling of analytical methods capable of identifying very small amounts of selenium in soils An efficient scheme of sequential extractions forms of selenium (SES consisting in atomic absorption spectrometry coupled with hydride generation (HGAAS has been developed into five experimental steps, detailed in the paper. This operational scheme has been applied to the analysis of chemical speciation in the following areas: the Bărăgan Plain and Central Dobrogea of Romania.

Polarographic determination of selenium and tellurium in silver-gold alloys

International Nuclear Information System (INIS)

Gornostaeva, T.D.; Shmargun, S.V.

1986-01-01

The determination of selenium and tellurium is of importance in monitoring the composition of silver-gold alloys (SGA) since these elements are harmful impurities in the pure metals. Tellurium is determined in silver alloys by atomic absorption and atomic emmission methods; selenium determination is made by atomic absorption methods. This paper examines the polarographic determination of silver and tellurium in SGA containing platinum metals and copper. Copper and the bulk of the platinum and palladium were removed by precipitating selenium and tellurium with potassium hypophosphite in the elementary state from 6 M HC1. The results of an analysis of samples of SGA according to the proposed method were compared with the results obtained by the atomic absorption method. the relative deviation in the determination of 0.02-1.0% by weight selenium and tellurium does not exceed 0.12 (n = 5)

Hypercholesterolemia and apolipoprotein B expression: Regulation by selenium status

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Bansal Mohinder P

2005-11-01

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

Morphology and thermodynamic characteristics of selenium-containing nanostructures based on polymethacrylic acid

Science.gov (United States)

Valueva, S. V.; Borovikova, L. N.; Vylegzhanina, M. E.; Sukhanova, T. E.

2010-09-01

The morphology and thermodynamic characteristics of nanostructures formed as a result of the reduction of the selenium ion in a selenite-ascorbate redox system in water solutions of polymethacrylic acid were studied by molecular optics and atomic-force microscopy. The dependence of the morphology of the selenium-containing nanostructures on the mass selenium-to-polymer ratio (ν) in solution was determined. It was established that a large number of macromolecules (up to 4300) is adsorbed on the selenium nanoparticles, leading to the formation of nanostructures with super-high molecular mass and an almost spherical form. It was shown that the density of the nanostructures, as calculated on the basis of the experimental data on the size and molecular mass of the nanocomposite, depends substantially on the selenium concentrations in the solution. The thermodynamic state of the solutions of nanostructures is described.

Aquatic selenium pollution is a global environmental safety issue

Science.gov (United States)

A. Dennis Lemly

2004-01-01

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

Enrichment of African catfish with functional selenium originating from garlic

NARCIS (Netherlands)

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

2008-01-01

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

Selenium enrichment pattern in flowering Chinese cabbage, cabbage and asparagus

NARCIS (Netherlands)

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

2006-01-01

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

Cross sectional study of serum selenium concentration and esophageal squamous dysplasia in western Kenya.

Science.gov (United States)

Pritchett, Natalie R; Burgert, Stephen L; Murphy, Gwen A; Brockman, John D; White, Russell E; Lando, Justus; Chepkwony, Robert; Topazian, Mark D; Abnet, Christian C; Dawsey, Sanford M; Mwachiro, Michael M

2017-12-08

Low serum selenium status has been associated with increased risk of esophageal squamous cell carcinoma (ESCC). East Africa is a region of high ESCC incidence and is known to have low soil selenium levels, but this association has not previously been evaluated. In this study we assessed the association of serum selenium concentration and the prevalence of esophageal squamous dysplasia (ESD), the precursor lesion of ESCC, in a cross-sectional study of subjects from Bomet, Kenya. 294 asymptomatic adult residents of Bomet, Kenya completed questionnaires and underwent endoscopy with Lugol's iodine staining and biopsy for detection of ESD. Serum selenium concentrations were measured by instrumental neutron activation analysis. Odds ratios (OR) and confidence intervals (95% CI) for associations between serum selenium and ESD were calculated using unconditional logistic regression. The mean serum selenium concentration was 85.5 (±28.3) μg/L. Forty-two ESD cases were identified (14% of those screened), including 5 (12%) in selenium quartile 1 (Q1), 5 (12%) in Q2, 15 (36%) in Q3, and 17 (40%) in Q4. Higher serum selenium was associated with prevalence of ESD (Q4 vs Q1: OR: 3.03; 95% CI: 1.05-8.74) and this association remained after adjusting for potential confounders (Q4 vs Q1: OR: 3.87; 95% CI: 1.06-14.19). This is the first study to evaluate the association of serum selenium concentration and esophageal squamous dysplasia in an African population at high risk for ESCC. We found a positive association between higher serum selenium concentration and prevalence of ESD, an association contrary to our original hypothesis. Further work is needed to better understand the role of selenium in the etiology of ESCC in this region, and to develop effective ESCC prevention and control strategies.

Neutron activation analysis applied to the determination of selenium in bovine plasma

International Nuclear Information System (INIS)

Hevia, Sonia E.; Resnizky, Sara M.; Gil, Susana B.; Pawlak, Eva

1999-01-01

The procedure used to determine selenium in bovine plasma by neutron irradiation of the samples, followed by a radiochemical separation, is described. This procedure allows the direct determination of the value of the selenium plasmatic level, instead of the indirect conventional method that determines the blood glutathion peroxidase enzyme, as an indicator of the selenium content in the blood. (author)

Mobilization of selenium from the Mancos Shale and associated soils in the lower Uncompahgre River Basin, Colorado

Science.gov (United States)

Mast, M. Alisa; Mills, Taylor J.; Paschke, Suzanne S.; Keith, Gabrielle; Linard, Joshua I.

2014-01-01

This study investigates processes controlling mobilization of selenium in the lower part of the Uncompahgre River Basin in western Colorado. Selenium occurs naturally in the underlying Mancos Shale and is leached to groundwater and surface water by limited natural runoff, agricultural and domestic irrigation, and leakage from irrigation canals. Soil and sediment samples from the study area were tested using sequential extractions to identify the forms of selenium present in solid phases. Selenium speciation was characterized for nonirrigated and irrigated soils from an agricultural site and sediments from a wetland formed by a leaking canal. In nonirrigated areas, selenium was present in highly soluble sodium salts and gypsum. In irrigated soils, soluble forms of selenium were depleted and most selenium was associated with organic matter that was stable under near-surface weathering conditions. Laboratory leaching experiments and geochemical modeling confirm that selenium primarily is released to groundwater and surface water by dissolution of highly soluble selenium-bearing salts and gypsum present in soils and bedrock. Rates of selenium dissolution determined from column leachate experiments indicate that selenium is released most rapidly when water is applied to previously nonirrigated soils and sediment. High concentrations of extractable nitrate also were found in nonirrigated soils and bedrock that appear to be partially derived from weathered organic matter from the shale rather than from agricultural sources. Once selenium is mobilized, dissolved nitrate derived from natural sources appears to inhibit the reduction of dissolved selenium leading to elevated concentrations of selenium in groundwater. A conceptual model of selenium weathering is presented and used to explain seasonal variations in the surface-water chemistry of Loutzenhizer Arroyo, a major tributary contributor of selenium to the lower Uncompahgre River.

Selenium status, thyroid volume, and multiple nodule formation in an area with mild iodine deficiency

DEFF Research Database (Denmark)

Rasmussen, Lone Banke; Schomburg, Lutz; Kohrle, Josef

2011-01-01

) introduction of iodine fortification. Serum selenium concentration and urinary iodine were measured, and the thyroid gland was examined by ultrasonography in the same subjects. Associations between serum selenium concentration and thyroid parameters were examined in multiple linear regression models...... or logistic regression models.Results: Serum selenium concentration was found to be significantly, negatively associated with thyroid volume (P=0.006), and a low selenium status significantly increased the risk for thyroid enlargement (P=0.007). Furthermore, low serum selenium status had a tendency...

Biomarkers of selenium status

Science.gov (United States)

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

Monitoring of selenium in macrophytes - the case of Slovenia.

Science.gov (United States)

Mechora, Špela; Germ, Mateja; Stibilj, Vekoslava

2014-09-01

This paper examines macrophytes from various locations in Slovenian streams for selenium (Se) content in an attempt to discover if Se contamination is present and if Se uptake varies between sampling sites. For this purpose, macrophytes and water from ten locations in the Notranjska and Central regions (Slovenia) with different land use in the catchment were sampled. To assess the environmental conditions of the streams the Riparian, Channel, and Environment (RCE) inventory was applied, which revealed that investigated stretches of streams fall into RCE classes III, IV and V. The concentration of Se in water at all locations was less than 1μgSeL(-1). The Se content in macrophytes differed between sampling sites, with the highest content of Se in samples from Žerovniščica stream and the lowest in samples from Lipsenjščica stream. The content of Se was the highest in moss samples (3038ngSeg(-1) DM) and in the amphibious species Veronica anagallis-aquatica (1507ngSeg(-1) DM). Copyright © 2014 Elsevier Ltd. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

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

1991-12-31

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

Enhanced osteoblast adhesion on nanostructured selenium compacts for anti-cancer orthopedic applications

Directory of Open Access Journals (Sweden)

Phong Tran

2008-10-01

Full Text Available Phong Tran1, Thomas J Webster21Physics Department; 2Division of Engineering and Department of Orthopedics, Brown University, Providence, USAAbstract: Metallic bone implants possess numerous problems limiting their long-term efficacy, such as poor prolonged osseointegration, stress shielding, and corrosion under in vivo environments. Such problems are compounded for bone cancer patients since numerous patients receive orthopedic implants after cancerous bone resection. Unfortunately, current orthopedic materials were not originally developed to simultaneously increase healthy bone growth (as in traditional orthopedic implant applications while inhibiting cancerous bone growth. The long-term objective of the present research is to investigate the use of nano-rough selenium to prevent bone cancer from re-occurring while promoting healthy bone growth for this select group of cancer patients. Selenium is a well known anti-cancer chemical. However, what is not known is how healthy bone cells interact with selenium. To determine this, selenium, spherical or semispherical shots, were pressed into cylindrical compacts and these compacts were then etched using 1N NaOH to obtain various surface structures ranging from the micron, submicron to nano scales. Changes in surface chemistry were also analyzed. Through these etching techniques, results of this study showed that biologically inspired surface roughness values were created on selenium compacts to match that of natural bone roughness. Moreover, results showed that healthy bone cell adhesion increased with greater nanometer selenium roughness (more closely matching that of titanium. In this manner, this study suggests that nano-rough selenium should be further tested for orthopedic applications involving bone cancer treatment.Keywords: selenium, nano-rough, osteoblast, cancer, chemopreventive

Selenium poisoning of fish by coal ash wastewater in Herrington Lake, Kentucky.

Science.gov (United States)

Lemly, A Dennis

2018-04-15

Selenium pollution from the E.W. Brown Electric Generating Station was investigated in Herrington Lake, KY. Coal ash wastewater is discharged as surface water overflow from ash disposal ponds into the lake via a National Pollutant Discharge Elimination System permit issued by the Kentucky Division of Water, but the permit does not restrict or limit the amount of selenium released. Unpermitted discharges occur from seeps and drainage through leaks in ash pond dams. Together, these discharges have resulted in selenium concentrations in water, sediment, benthic macroinvertebrates, and fish that are 2-9 times the level that is toxic for fish reproduction and survival. A large proportion (12.2%, or 25 times background) of juvenile largemouth bass (Micropterus salmoides, the only species examined) exhibited spinal and/or craniofacial malformations that are consistent with selenium poisoning. Teratogenic Deformity Index values indicated a 3.05% population-level impact on the bass fishery, with total selenium-induced mortality (including pre-swimup mortality) estimated to be in excess of 25% per year. These findings confirm that coal ash discharges into Herrington Lake are contributing selenium to the Lake that is poisoning fish. Copyright © 2017 Elsevier Inc. All rights reserved.

Inhibition of the NLRP3 inflammasome attenuates foam cell formation of THP-1 macrophages by suppressing ox-LDL uptake and promoting cholesterol efflux.

Science.gov (United States)

Chen, Liang; Yao, Qiying; Xu, Siwei; Wang, Hongyan; Qu, Peng

2018-01-01

The NOD-like receptor family, pyrin domain-containing protein 3 (NLRP3) inflammasome plays an important role in the development of atherosclerosis. The activated NLRP3 inflammasome has been reported to promote macrophage foam cell formation, but not all studies have obtained the same result, and how NLRP3 inflammasome is involved in the formation of foam cells remains elusive. We used selective NLRP3 inflammasome inhibitors and NLRP3-deficient THP-1 cells to assess the effect of NLRP3 inflammasome inhibition on macrophage foam cell formation, oxidized low-density lipoprotein (ox-LDL) uptake, esterification, and cholesterol efflux, as well as the expression of associated proteins. Inhibition of the NLRP3 inflammasome attenuated foam cell formation, diminished ox-LDL uptake, and promoted cholesterol efflux from THP-1 macrophages. Moreover, it downregulated CD36, acyl coenzyme A: cholesterol acyltransferase-1 and neutral cholesterol ester hydrolase expression; upregulated ATP-binding cassette transporter A1 (ABCA1) and scavenger receptor class B type I (SR-BI) expression; but had no effect on the expression of scavenger receptor class A and ATP-binding cassette transporter G1. Collectively, our findings show that inhibition of the NLRP3 inflammasome decreases foam cell formation of THP-1 macrophages via suppression of ox-LDL uptake and enhancement of cholesterol efflux, which may be due to downregulation of CD36 expression and upregulation of ABCA1 and SR-BI expression, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

Plasma Selenium Biomarkers in Low Income Black and White Americans from the Southeastern United States

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Hargreaves, Margaret K.; Liu, Jianguo; Buchowski, Maciej S.; Patel, Kushal A.; Larson, Celia O.; Schlundt, David G.; Kenerson, Donna M.; Hill, Kristina E.; Burk, Raymond F.; Blot, William J.

2014-01-01

Biomarkers of selenium are necessary for assessing selenium status in humans, since soil variation hinders estimation of selenium intake from foods. In this study, we measured the concentration of plasma selenium, selenoprotein P (SEPP1), and glutathione peroxidase (GPX3) activity and their interindividual differences in 383 low-income blacks and whites selected from a stratified random sample of adults aged 40–79 years, who were participating in a long-term cohort study in the southeastern United States (US). We assessed the utility of these biomarkers to determine differences in selenium status and their association with demographic, socio-economic, dietary, and other indicators. Dietary selenium intake was assessed using a validated food frequency questionnaire designed for the cohort, matched with region-specific food selenium content, and compared with the US Recommended Dietary Allowances (RDA) set at 55 µg/day. We found that SEPP1, a sensitive biomarker of selenium nutritional status, was significantly lower among blacks than whites (mean 4.4±1.1 vs. 4.7±1.0 mg/L, p = 0.006), with blacks less than half as likely to have highest vs. lowest quartile SEPP1 concentration (Odds Ratio (OR) 0.4, 95% Confidence Interval (CI) 0.2–0.8). The trend in a similar direction was observed for plasma selenium among blacks and whites, (mean 115±15.1 vs. 118±17.7 µg/L, p = 0.08), while GPX3 activity did not differ between blacks and whites (136±33.3 vs. 132±33.5 U/L, p = 0.320). Levels of the three biomarkers were not correlated with estimated dietary selenium intake, except for SEPP1 among 10% of participants with the lowest selenium intake (≤57 µg/day). The findings suggest that SEPP1 may be an effective biomarker of selenium status and disease risk in adults and that low selenium status may disproportionately affect black and white cohort participants. PMID:24465457

Selenium deficiency and pregnancy outcome in pregnant women with HIV in Lagos, Nigeria.

Science.gov (United States)

Okunade, Kehinde S; Olowoselu, Olusola F; Osanyin, Gbemisola E; John-Olabode, Sarah; Akanmu, Sulaimon A; Anorlu, Rose I

2018-04-16

To investigate the prevalence of maternal selenium deficiency and its effects on pregnancy outcomes in pregnant women with HIV in Lagos, Nigeria. The present descriptive cross-sectional study enrolled women aged 15-49 years with HIV who were at 14-26 weeks of a singleton pregnancy and were attending Lagos University Teaching Hospital, Lagos, Nigeria, between August 1, 2016, and April 30, 2017. Participants were selected by consecutive sampling and baseline data were collected through interviews. Venous blood samples were obtained to measure selenium concentrations, and associations between low maternal selenium concentrations (defined as <0.89 μmol/L) and pregnancy outcomes were examined using bivariate and multivariate analysis. The final analysis included 113 patients; selenium deficiency was recorded in 23 (20.4%) patients. Women with selenium deficiency had an approximately eight-fold higher risk of preterm delivery (adjusted odds ratio 7.61, 95% confidence interval 4.37-18.89; P=0.031) and of delivering a term neonate with a low delivery weight (adjusted odds ratio 8.11, 95% confidence interval 3.27-17.22; P=0.012), compared with women with a normal selenium concentration. The prevalence of selenium deficiency among pregnant women with HIV in Lagos was relatively high. The significant associations observed between maternal selenium deficiency and adverse pregnancy outcomes could have implications for the future management of HIV in pregnancy. © 2018 International Federation of Gynecology and Obstetrics.

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

Science.gov (United States)

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

2002-01-01

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

Radio protective effects of selenium on rats

International Nuclear Information System (INIS)

Bakir, A.; Alya, G

2005-11-01

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

Evaluation of Selenium Content of Plant Samples Collected from Indigenous Sources for Se-supplementation

International Nuclear Information System (INIS)

Mahmud, T.; Sosan, A.; Rehman, R.; Abbas, A.

2010-01-01

Selenium contents were evaluated in different plant species such as Canola (Brassica napus), Sunflower (Helianthus annus), Turmeric (Curcuma longa), Soyabean Seeds (Glycine max) and Akk (Calotropis procera) in order to access their possibility for Se-supplementation. The dry ash of bulb of Turmeric and seeds of Canola, Sunflower, and Soyabean were digested in concentrated HNO/sub 3/, HClO/sub 4/ and HCl to obtain selenium (IV). After adding different reagents, stable blue colored complex was formed. From this colored complex, selenium (IV) was determined by UV/visible spectrophotometer. This work was carried out in an attempt to obtain information concerning the amount of selenium present in different plants. It was observed that Akk is a good accumulator of selenium as it contains almost 30 mu g selenium per gram and can be used for different medicinal applications. (author)

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

Science.gov (United States)

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.

An Introduction to Testing Web Applications with twill and Selenium

CERN Document Server

Brown, Titus; Huggins, Jason

2007-01-01

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

Toenail selenium level among healthy residents of two Polish Districts

International Nuclear Information System (INIS)

Zukowska, J.; Biziuk, M.; Bode, P.

2009-01-01

The goal of this study was to evaluate the selenium mass fraction in toenail clippings taken from random inhabitants living in various areas of the Pomeranian (Northern Poland) and Lubuskie (Western Poland) Districts. Toenail clippings were analyzed by instrumental neutron activation analysis (INAA) giving means of 0.57±0.10 and 0.60±0.16 mg x kg -1 for the two areas, respectively, but the difference was statistically not significant. In additional, it was found that gender, age, body mass index (BMI), smoking, and selenium supplementation are factors with apparent effects to the selenium levels in toenail clippings. (author)

Clinically relevant strategies for lowering cardiomyocyte glucose uptake for 18F-FDG imaging of myocardial inflammation in mice

International Nuclear Information System (INIS)

Thackeray, James T.; Bankstahl, Jens P.; Bengel, Frank M.; Wang, Yong; Wollert, Kai C.

2015-01-01

Myocardial inflammation is an emerging target for novel therapies and thus for molecular imaging. Positron emission tomography (PET) with 18 F-fluorodeoxyglucose (FDG) has been employed, but requires an approach for suppression of cardiomyocyte uptake. We tested clinically viable strategies for their suitability in mouse models in order to optimize preclinical imaging protocols. C57BL/6 mice (n = 56) underwent FDG PET under various conditions. In healthy animals, the effect of low-dose (5 units/kg) or high-dose (500 units/kg, 15 min prior) intravenous heparin, extended fasting (18 h) and the impact of conscious injection with limited, late application of isoflurane anaesthesia after 40 min of conscious uptake were examined in comparison to ketamine/xylazine anaesthesia. Conscious injection/uptake strategies were further evaluated at 3 days after permanent coronary artery occlusion. Under continuous isoflurane anaesthesia, neither heparin administration nor extended fasting significantly impacted myocardial 18 F-FDG accumulation. Injection with 40 min uptake in awake mice resulted in a marked reduction of global myocardial 18 F-FDG uptake compared to standard isoflurane anaesthesia (5.7 ± 1.1 %ID/g vs 30.2 ± 7.9 %ID/g, p < 0.01). Addition of heparin and fasting further reduced uptake compared to conscious injection alone (3.8 ± 1.5 %ID/g, p < 0.01) similar to ketamine/xylazine (2.4 ± 2.2 %ID/g, p < 0.001). In the inflammatory phase, 3 days after myocardial infarction, conscious injection/uptake with and without heparin/fasting identified a marked increase in myocardial 18 F-FDG accumulation that was similar to that observed under ketamine/xylazine. Continuous isoflurane anaesthesia obscures any suppressive effect of heparin or fasting on cardiomyocyte glucose utilization. Conscious injection of FDG in rodents significantly reduces cardiomyocyte uptake and enables further suppression by heparin and fasting, similar to clinical observations. In contrast to

Nanosized Selenium: A Novel Platform Technology to Prevent Bacterial Infections

Science.gov (United States)

Wang, Qi

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

Potential reproduction and response of selenium and zinc mineral supplementation on quality of goat samosir semen

Science.gov (United States)

Siswoyo, P.; Tafsin, M.; Handarini, R.

2018-02-01

The present study was conducted to investigate the effect of suppllementattion of selenium and zinc on semen quality and growth of samosir goat. The experimental design used latin square design (4x4). The treatment supplementation mineral on multi nutrient block (MNB) composed of without sipplementation (p0), +10ppm selenium (p1), +10ppm zinc (p2), +10ppm selenium and +10ppm zinc (p3). The result showed that supplementation mineral selenium and zinc increased significantly (pgoat were supplemented by selenium and zinc influenced motility, viability, volume concentration, and responding hypo osmotic swelling (HOS). Combination supplementation selenium and zinc significanly had higher semen quality than ither treatment. It is concluded that supplementation selenium and zinc improve growth and semen quality of samosir goat.

In vitro antioxidant and antiproliferative activities of selenium-containing phycocyanin from selenium-enriched Spirulina platensis.

Science.gov (United States)

Chen, Tianfeng; Wong, Yum-Shing

2008-06-25

Both selenium and phycocyanin have been reported to show potent cancer chemopreventive activities. In this study, we investigated the in vitro antioxidant and antiproliferative activities of selenium-containing phycocyanin (Se-PC) purified from selenium-enriched Spirulina platensis. The antioxidant activity of Se-PC was evaluated by using four different free radical scavenging assays, namely, the 2,2'-azinobis-3-ethylbenzothiazolin-6-sulfonic acid (ABTS) assay, 1,1-diphenyl-2-picryhydrazyl (DPPH) assay, superoxide anion scavenging assay, and erythrocyte hemolysis assay. The results indicated that Se-PC exhibited stronger antioxidant activity than phycocyanin by scavenging ABTS, DPPH, superoxide anion, and 2,2'-azobis-(2-amidinopropane)dihydrochloride free radicals. Se-PC also showed dose-dependent protective effects on erythrocytes against H 2O 2-induced oxidative DNA damage as evaluated by the Comet assay. Moreover, Se-PC was identified as a potent antiproliferative agent against human melanoma A375 cells and human breast adenocarcinoma MCF-7 cells. Induction of apoptosis in both A375 and MCF-7 cells by Se-PC was evidenced by accumulation of sub-G1 cell populations, DNA fragmentation, and nuclear condensation. Further investigation on intracellular mechanisms indicated that depletion of mitochondrial membrane potential (DeltaPsi m) was involved in Se-PC-induced cell apoptosis. Our findings suggest that Se-PC is a promising organic Se species with potential applications in cancer chemoprevention.

Manganese and selenium concentrations in cerebrospinal fluid of seriously ill children.

Science.gov (United States)

Franěk, Tomáš; Kotaška, Karel; Průša, Richard

2017-11-01

The homeostasis of essential trace elements such as selenium and manganese may be altered in patients with severe diseases of various etiologies (trauma brain injuries, tumors, leukemias, lymphomas, neurological diseases). Concentration of manganese and selenium were determined in cerebrospinal fluid by electrothermal atomic absorption spectrometry in 50 hospitalized children with various clinical ethiologies including oncological, neurological, and brain related diseases. The concentrations of manganese in cerebrospinal fluid of children were 0.97±0.67 μg/L. The concentrations of selenium were 13.3±3.5 μg/L. The concentrations were similar as published in adults. The values did not correlated with the age, gender and severity of the disease. We evaluated values of selenium and manganese in cerebrospinal fluid of seriously diseased children. © 2017 Wiley Periodicals, Inc.

Selenium and breast cancer risk: A prospective nested case-control study on serum selenium levels, smoking habits and overweight.

Science.gov (United States)

Sandsveden, Malte; Manjer, Jonas

2017-11-01

Previous research has not been conclusive regarding the association between selenium (Se) and breast cancer. This study was conducted to clarify if there is an association between prediagnostic serum Se levels and breast cancer risk. A population based cohort, the Malmö Diet and Cancer Study, was used and linked with the Swedish cancer registry up to 31 December 2013. Our study included 1,186 women with breast cancer and an equal number of controls. Selenium levels were analysed from stored serum samples. The included individuals were divided into quartiles based on Se value and we compared breast cancer cases with controls using logistic regression yielding odds ratios (OR) with 95% confidence intervals. Serum Se was also analysed as a continuous variable regarding breast cancer risk. The analyses were adjusted for established risk factors and stratified on smoking status and body mass index (BMI). When comparing the highest Se quartile with the lowest, the adjusted OR for breast cancer was 0.98 (0.75-1.26). With selenium as a continuous variable the adjusted OR was 1.00 (1.00-1.01) per 10 ng/ml. When comparing the highest with the lowest Se quartile in women with BMI > 25 kg/m 2 the adjusted OR was 0.77 (0.53-1.14). We conclude that it is unlikely that prediagnostic serum selenium is overall associated with breast cancer risk and no modifying effect from BMI or smoking was seen. © 2017 UICC.

Calcium oxalate druses affect leaf optical properties in selenium-treated Fagopyrum tataricum.

Science.gov (United States)

Golob, Aleksandra; Stibilj, Vekoslava; Nečemer, Marijan; Kump, Peter; Kreft, Ivan; Hočevar, Anja; Gaberščik, Alenka; Germ, Mateja

2018-03-01

Plants of the genus Fagopyrum contain high levels of crystalline calcium oxalate (CaOx) deposits, or druses, that can affect the leaf optical properties. As selenium has been shown to modify the uptake and accumulation of metabolically important elements such as calcium, we hypothesised that the numbers of druses can be altered by selenium treatment, and this would affect the leaf optical properties. Tartary buckwheat (Fagopyrum tataricum Gaertn.) was grown outdoors in an experimental field. At the beginning of flowering, plants were foliarly sprayed with sodium selenate solution at 10 mg selenium L -1 or only with water. Plant morphological, biochemical, physiological and optical properties were examined, along with leaf elemental composition and content. Se spraying did not affect leaf biochemical and functional properties. However, it increased leaf thickness and the contents of Se in the leaves, and decreased the density of calcium oxalate druses in the leaves. Except Se content, Se spraying did not affect contents of other elements in leaves, including total calcium per dry mass of leaf tissue. Redundancy analysis showed that of all parameters tested, only the calcium oxalate druses parameters were significant in explaining the variability of the leaf reflectance and transmittance spectra. The density of CaOx druses positively correlated with the reflectance in the blue, green, yellow and UV-B regions of the spectrum, while the area of CaOx druses per mm 2 of leaf transection area positively correlated with the transmittance in the green and yellow regions of the spectrum. Copyright © 2018 Elsevier B.V. All rights reserved.

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

Directory of Open Access Journals (Sweden)

А. Sobolev

2017-07-01

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

The application of Fe–Mn hydrous oxides based adsorbent for removing selenium species from water

KAUST Repository

Szlachta, Małgorzata

2013-02-01

In this study, the adsorptive removal of selenium(IV) and selenium(VI) from water by a newly developed ion exchange adsorbent, based on Fe(III) and Mn(III) hydrous oxides, was examined. This study was conducted to determine the influence of various operating parameters, such as initial anion concentration, contact time, adsorbent dose, pH, solution temperature, and the presence of competitive anions, on the treatment performance. The high Se(IV) adsorptive capacity of the adsorbent (up to 41.02. mg/g at pH 4) was due to its high affinity for selenite, as reflected in the fast rate of uptake (batch studies) and an efficient long-term removal (column experiments). Although adsorption of anions traditionally decreases as pH increases, the mixed adsorbent was capable of purifying large volumes of Se(IV)-containing water (at pH 7) to reach concentrations lower than 10 μg/L, which meets the European Commission standards. The presence of sulphate and carbonate did not influence Se(IV) adsorption. However, high phosphate and silicate concentrations may have decreased the removal efficiency of Se(IV). Data from the batch and column adsorption experiments were fitted with a number of approved models, which revealed the adsorption mechanism and allowed for a comparison of the results. © 2012 Elsevier B.V.

Selenium level in the environment and the population of Zhoukoudian area, Beijing, China

Energy Technology Data Exchange (ETDEWEB)

Li Na [Department of Epidemiology and Biostatistics, Peking University Health Science Center, 38 Xue Yuan Road, Hai, Dian District, Beijing 100083 (China); Gao Zhidong [Department of Epidemiology and Biostatistics, Peking University Health Science Center, 38 Xue Yuan Road, Hai, Dian District, Beijing 100083 (China); Luo Degang [Department of Epidemiology and Biostatistics, Peking University Health Science Center, 38 Xue Yuan Road, Hai, Dian District, Beijing 100083 (China); Tang Xun [Department of Epidemiology and Biostatistics, Peking University Health Science Center, 38 Xue Yuan Road, Hai, Dian District, Beijing 100083 (China); Chen Dafang [Department of Epidemiology and Biostatistics, Peking University Health Science Center, 38 Xue Yuan Road, Hai, Dian District, Beijing 100083 (China); Hu Yonghua [Department of Epidemiology and Biostatistics, Peking University Health Science Center, 38 Xue Yuan Road, Hai, Dian District, Beijing 100083 (China)]. E-mail: yhhu@bjmu.edu.cn

2007-08-01

The objective of this study was to detect the selenium level in the environment and the population of Zhoukoudian area, Beijing, and to discuss the influence of various factors on serum selenium level. The soil, drinking water, and foodstuff samples and venous blood samples of 401 individuals were obtained to determine the selenium level by gas chromatograph equipped with a {sup 63}Ni electron capture detector (ECD). The selenium level was 0.210 {+-} 0.013 {mu}g/g in soil, 0.017 {mu}g/L {+-} 0.002 in drinking water, 0.034 {+-} 0.002 {mu}g/g in rice, and 0.034 {+-} 0.012 {mu}g/g in wheat flour. This index showed that the Zhoukoudian area of Beijing was a moderate or marginal level selenium ecological landscape. The mean serum selenium level of the population was 75.01 {+-} 28.35 {mu}g/L, ranging between 35.2 and 160.4 {mu}g/L. A total of 279 (69.6%) individuals exhibited serum selenium level below 80 {mu}g/L, which is the lowest threshold for the activity of glutathione peroxidases (GPx) in vivo. A total of 35 (8.5%) individuals exhibited serum selenium level below 45 {mu}g/L. It is widely recommended that below this value (45 {mu}g/L) there is an increased risk of cardiovascular disease and cancer. Multiple linear regression analysis showed that serum selenium level was positively associated with body mass index ({beta} = 0.137; P = 0.011), serum total cholesterol TC ({beta} = 0.785; P = 0.000), however, negatively associated with systolic blood pressure ({beta} = - 0.172; P = 0.023), serum triglyceride ({beta} = - 0.170; P = 0.007), high density lipoprotein-cholesterol ({beta} = - 0.121; P = 0.027), and low high density lipoprotein-cholesterol ({beta} = - 0.568; P = 0.027)

Selenium level in the environment and the population of Zhoukoudian area, Beijing, China

International Nuclear Information System (INIS)

Li Na; Gao Zhidong; Luo Degang; Tang Xun; Chen Dafang; Hu Yonghua

2007-01-01

The objective of this study was to detect the selenium level in the environment and the population of Zhoukoudian area, Beijing, and to discuss the influence of various factors on serum selenium level. The soil, drinking water, and foodstuff samples and venous blood samples of 401 individuals were obtained to determine the selenium level by gas chromatograph equipped with a 63 Ni electron capture detector (ECD). The selenium level was 0.210 ± 0.013 μg/g in soil, 0.017 μg/L ± 0.002 in drinking water, 0.034 ± 0.002 μg/g in rice, and 0.034 ± 0.012 μg/g in wheat flour. This index showed that the Zhoukoudian area of Beijing was a moderate or marginal level selenium ecological landscape. The mean serum selenium level of the population was 75.01 ± 28.35 μg/L, ranging between 35.2 and 160.4 μg/L. A total of 279 (69.6%) individuals exhibited serum selenium level below 80 μg/L, which is the lowest threshold for the activity of glutathione peroxidases (GPx) in vivo. A total of 35 (8.5%) individuals exhibited serum selenium level below 45 μg/L. It is widely recommended that below this value (45 μg/L) there is an increased risk of cardiovascular disease and cancer. Multiple linear regression analysis showed that serum selenium level was positively associated with body mass index (β = 0.137; P = 0.011), serum total cholesterol TC (β = 0.785; P = 0.000), however, negatively associated with systolic blood pressure (β = - 0.172; P = 0.023), serum triglyceride (β = - 0.170; P = 0.007), high density lipoprotein-cholesterol (β = - 0.121; P = 0.027), and low high density lipoprotein-cholesterol (β = - 0.568; P = 0.027)

Selenium enrichment on Cordyceps militaris link and analysis on its main active components.

Science.gov (United States)

Dong, Jing Z; Lei, C; Ai, Xun R; Wang, Y

2012-03-01

To investigate the effects of selenium on the main active components of Cordyceps militaris fruit bodies, selenium-enriched cultivation of C. militaris and the main active components of the fruit bodies were studied. Superoxide dismutase (SOD) activity and contents of cordycepin, cordycepic acid, and organic selenium of fruit bodies were sodium selenite concentration dependent; contents of adenosine and cordycep polysaccharides were significantly enhanced by adding sodium selenite in the substrates, but not proportional to sodium selenite concentrations. In the cultivation of wheat substrate added with 18.0 ppm sodium selenite, SOD activity and contents of cordycepin, cordycepic acid, adenosine, cordycep polysaccharides, and total amino acids were enhanced by 121/145%, 124/74%, 325/520%, 130/284%, 121/145%, and 157/554%, respectively, compared to NS (non-selenium-cultivated) fruit bodies and wild Cordyceps sinensis; organic selenium contents of fruit bodies reached 6.49 mg/100 g. So selenium-enriched cultivation may be a potential way to produce more valuable medicinal food as a substitute for wild C. sinensis.

Marginal selenium deficiency down-regulates inflammation-related genes in splenic leukocytes of the mouse

NARCIS (Netherlands)

Kipp, A.P.; Banning, A.; Schothorst, van E.M.; Meplan, C.; Coort, S.L.; Evelo, C.; Keijer, J.; Hesketh, J.; Brigelius, R.

2012-01-01

Moderate selenium deficiency may lead to an impaired capacity to cope with health challenges. Functional effects of suboptimal selenium intake are not fully known, and biomarkers for an insufficient selenium supply are inadequate. We therefore fed mice diets of moderately deficient or adequate

Selenium speciation influences bioaccumulation in Limnodynastes peronii tadpoles

Energy Technology Data Exchange (ETDEWEB)

Lanctôt, C.M., E-mail: c.lanctot@griffith.edu.au [Central Queensland University, School of Medical and Applied Sciences, Gladstone, QLD 4680 (Australia); Australian Rivers Institute, School of Environment, Griffith University, Southport, QLD 4215 (Australia); Melvin, S.D., E-mail: s.melvin@griffith.edu.au [Australian Rivers Institute, School of Environment, Griffith University, Southport, QLD 4215 (Australia); Cresswell, T., E-mail: tom.cresswell@ansto.gov.au [Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia)

2017-06-15

Highlights: • Differences in SeIV and SeVI bioaccumulation and biodistribution were assessed. • Limnodynastes peronii tadpoles accumulated more selenite than selenate. • Selenium depuration kinetics was similar for both forms. • Tadpoles accumulated Se predominantly in the digestive and excretory organs. - Abstract: Despite being essential for animal health and fitness, Se has a relatively narrow range between deficiency and toxicity, and excess Se can cause a variety of adverse effects in aquatic organisms. Amphibians are particularly vulnerable to contaminants during larval aquatic life stage, because they can accumulate toxic ions through various routes including skin, gills, lungs and digestive tract. Few attempts have been made to understand the tissue-specific accumulation of trace elements, including the impacts of chemical speciation in developing amphibian larvae. We used radiolabelled {sup 75}Se to explore the biokinetics and tissue distributions of the two dominant forms occurring in surface waters, selenite (SeIV) and selenate (SeVI). Tadpoles of the native Australian frog Limnodynastes peronii were exposed to Se in both forms, and live-animal gamma spectroscopy was used to track accumulation and retention over time. Tissue biodistributions were also quantified at the end of the uptake and depuration phases. Results showed the bioconcentration of SeIV to be 3 times greater compared to SeVI, but rates of elimination were similar for both forms. This suggests a change of Se speciation within the organism prior to excretion. Depuration kinetics were best described by a one-phase exponential decay model, and tadpoles retained approximately 19% of the accumulated Se after 12 days of depuration in clean water. Selenium bioaccumulation was greatest in digestive and excretory organs, as well as the eye, which may directly relate to previously reported Se-induced impairments. Results demonstrate how the use of radiotracing techniques can significantly

Selenium homeostasis and induction of thioredoxin reductase during long term selenite supplementation in the rat

DEFF Research Database (Denmark)

Erkhembayar, Suvd; Mollbrink, Annelie; Eriksson, Malin

2011-01-01

-dependent increase in blood and liver selenium levels, with plateaus at 6 and 8weeks, respectively. These plateaus were reached at the same level of selenium regardless of dose, and no further accumulation was observed. A selenium-dependent increase in the activity of TrxR1 in parallel with the increase in liver...... selenium levels was also seen, and the induction of TrxR1 mRNA was seen only during the first three days of treatment, when the levels of selenium in the liver were increasing. Sodium selenite at 1 and 5μg/mL did not affect body weight or relative liver mass. We concluded that long-term treatment...... with selenite did not cause accumulation of selenium and that the activity of TrxR1 in the liver rose with the selenium levels. We therefore suggest that sodium selenite at doses up to 5μg/mL could be used for long-term tumour prevention....

Comparative effect of selenium and selenium tolerant microbes on brachiaria reptans l. growth

International Nuclear Information System (INIS)

Yasin, M.; Faisal, M.

2014-01-01

Brachiaria reptans L. is an annual grass. It is good fodder grass which is distributed in tropical Asia, Kenya, Pakistan and India and introduced throughout the tropics. In present study we determine the growth correlation among B. reptans, selenium (Se) and two Se tolerant bacteria (Bacillus licheniformis-YAP7 and Bacillus cereus-YAP6). Plants treated with Se showed a significant decrease in shoot length (33%) and fresh biomass (41%) compared to control. When plants were co-cultivated in the presence of bacteria or Se and bacteria both the shoot length increased (16-34%) significantly compared to control. B. reptans plants treated with Se have shown a significant decrease in peroxidase contents (59%) compared to control. However, bacterial inoculation of Se treated plants resulted in significant increase in peroxidase contents (113-171%). Selenium treatment caused increase in leaf soluble protein contents compared to control. In conclusion, bacteria can enhance B. reptans growth under Se stress. (author)

Mechanisms of selenium hyperaccumulation in plants: A survey of molecular, biochemical and ecological cues.

Science.gov (United States)

Lima, Leonardo Warzea; Pilon-Smits, Elizabeth A H; Schiavon, Michela

2018-04-04

Selenium (Se) is a micronutrient required for many life forms, but toxic at higher concentration. Plants do not have a Se requirement, but can benefit from Se via enhanced antioxidant activity. Some plant species can accumulate Se to concentrations above 0.1% of dry weight and seem to possess mechanisms that distinguish Se from its analog sulfur (S). Research on these so-called Se hyperaccumulators aims to identify key genes for this remarkable trait and to understand ecological implications. This review gives a broad overview of the current knowledge about Se uptake and metabolism in plants, with a special emphasis on hypothesized mechanisms of Se hyperaccumulation. The role of Se in plant defense responses and the associated ecological implications are discussed. Hyperaccumulators have enhanced expression of S transport and assimilation genes, and may possess transporters with higher specificity for selenate over sulfate. Genes involved in antioxidant reactions and biotic stress resistance are also upregulated. Key regulators in these processes appear to be the growth regulators jasmonic acid, salicylic acid and ethylene. Hyperaccumulation may have evolved owing to associated ecological benefits, particularly protection against pathogens and herbivores, and as a form of elemental allelopathy. Understanding plant Se uptake and metabolism in hyperaccumulators has broad relevance for the environment, agriculture and human and animal nutrition and may help generate crops with selenate-specific uptake and high capacity to convert selenate to less toxic, anticarcinogenic, organic Se compounds. Copyright © 2018 Elsevier B.V. All rights reserved.

Determination of selenium in food matrices by replicate sample neutron activation analysis

International Nuclear Information System (INIS)

Ventura, M.G.; Freitas, M.C.; Ventura, M.G.; Pacheco, A.M.G.

2009-01-01

The replicate sample instrumental neutron activation method was optimized and used for the determination of selenium in foodstuffs. The method was reliable, yielding accurate results. Lower detections limits were obtained after each successive irradiation. Different irradiation conditions were used depending on the type of sample. For samples with higher selenium contents (meat, fish, eggs), the measured selenium in the first replicate is in all cases larger than the detection limit, but a better accuracy was obtained with a larger number of replicates (2-3 replicates). For samples with extremely low selenium contents (vegetable samples), at least seven replicates were necessary to obtain a concentration value two times larger than the detection limit. (author)

Selenium, selenoprotein genes and Crohn's disease in a case-control population from Auckland, New Zealand.

Science.gov (United States)

Gentschew, Liljana; Bishop, Karen S; Han, Dug Yeo; Morgan, Angharad R; Fraser, Alan G; Lam, Wen Jiun; Karunasinghe, Nishi; Campbell, Bobbi; Ferguson, Lynnette R

2012-09-01

New Zealand has one of the highest incidence rates of Crohn's Disease (CD), whilst the serum selenium status of New Zealanders is amongst the lowest in the world. A prospective case-control study in Auckland, New Zealand considered serum selenium as a potential CD risk factor. Serum selenium levels were significantly lower in CD patients compared to controls (101.8 ± 1.02 vs. 111.1 ± 1.01 ng/mL) (p = 5.91 × 10(-8)). Recent detailed studies in the United Kingdom have suggested an optimal serum level around 122 ng/mL, making the average CD patient in New Zealand selenium deficient. Of the 29 single nucleotide polymorphisms (SNPs) tested, 13 were found to significantly interact with serum selenium on CD. After adjustment for multiple testing, a significant interaction with serum selenium on CD was found for three SNPs, namely rs17529609 and rs7901303 in the gene SEPHS1, and rs1553153 in the gene SEPSECS. These three SNPs have not been reported elsewhere as being significantly associated with selenium or CD. It is unclear as to whether lower selenium levels are a cause or an effect of the disease.

Examination of the selenium content of wheat grasses produced in different soil types in Csik Basin

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Tamás M.

2015-01-01

Full Text Available In the course of the research, we determined selenium and dry matter content of 35 wheat grass and 35 wheat seed samples. The selenium content of the preparation plant probes was measured by spectrofluorimetric determination (λexcitation = 380 nm, λemission = 519 nm of the resulted piazselenol complex. It was established that between the selenium content of the wheat grass and wheat seed the correlation coefficient was 0.36 at p = 0.05 level, which indicates a medium-close correlation. Similarly, there was a medium-close correlation between the selenium content of the wheat grass calculated on dry-matter basis and total selenium content of the wheat, with a correlation coefficient of 0.40 at p = 0.02 level. Afterwards, beside the selenium content, we measured the selenomethionine content by ion-exchange chromatography and highperformance liquid chromatography, and the organic selenium content was calculated. A very close correlation was established between the total selenium, selenomethionine and calculated organic selenium content of wheat (the correlation coefficients were between 0.92 and 0.99 at p = 0.01 level. The correlation between the selenomethionine content of wheat grass and wheat seed was very weak (r = 0.23.

Epigenetic Regulation of Inflammatory Gene Expression in Macrophages by Selenium

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

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

2014-10-01

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

Sulfur and selenium isotope separation by distillation

International Nuclear Information System (INIS)

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

1988-01-01

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

Sulfur and selenium isotope separation by distillation

International Nuclear Information System (INIS)

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

1989-01-01

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

Direct solution-phase synthesis of Se submicrotubes using Se powder as selenium source

International Nuclear Information System (INIS)

Yan Shancheng; Wang Haitao; Zhang Yuping; Li Shuchun; Xiao Zhongdang

2009-01-01

The selenium submicrotubes were directly prepared using Se powder as selenium source by microwave-assisted method. Field-emission scan electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were adopted to characterize the as-prepared products. The results of high-resolution transmission electron microscopy (HRTEM) and XRD pattern proved that the selenium submicrotubes were single crystalline in nature and [0 0 1] oriented. A possible growth mechanism of the selenium submicrotubes was proposed. The effects of the experimental conditions, such as alkaline concentration and solvent properties, on the morphology and dimension of the products have also been discussed

Structure of amorphous selenium studied by neutron diffraction

DEFF Research Database (Denmark)

Hansen, Flemming Yssing; Knudsen, Torben Steen; Carneiro, K.

1975-01-01

Neutron diffraction measurements on amorphous selenium have been performed at 293 and 80 K. Careful analyses of the instrumental corrections were made to avoid systematic errors in the measured structure factor S (kappa) in the wave vector region 0 ? kappa ? 12 Å−1. As a result of the data...... treatment, the neutron scattering cross sections of selenium are determined to be sigmacoh = 8.4±0.1 b and sigmainc = 0.1±0.1 b. Using the fact that S (kappa) for large kappa's is determined by the short distances in the sample, a new method for extrapolation of the experimental S (kappa) until convergence....... Finally, we give a brief discussion of the different models for the structure of amorphous selenium, taking both diffraction measurements and thermodynamic considerations into account. The Journal of Chemical Physics is copyrighted by The American Institute of Physics....

Green synthesis of selenium nanoparticles by excimer pulsed laser ablation in water

OpenAIRE

O. Van Overschelde; G. Guisbiers; R. Snyders

2013-01-01

Pure selenium nanoparticles were successfully synthesized by Liquid Phase - Pulsed Laser Ablation (LP-PLA) in de-ionized water. Excimer laser (248 nm) operating at low fluence (F ∼ 1 J/cm2) was used to generate colloidal solutions of selenium nanoparticles. The obtained selenium nanoparticles were characterized by UV-visible spectroscopy, Raman spectroscopy, Dynamic Light Scattering, and Transmission Electron Microscopy. We describe the multi-modal size distributions generated and use the cen...

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

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Josip Novoselec

2013-12-01

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

Serum selenium concentration in maternal and umbilical cord blood. Relation to course and outcome of pregnancy

DEFF Research Database (Denmark)

Bro, S; Berendtsen, H; Nørgaard, J

1988-01-01

The present knowledge of the role of selenium in human fetal and neonatal development is sparse. In this study we measured serum selenium concentrations in maternal and umbilical cord blood from 500 Danish mothers at delivery, looking for a relationship between various maternal and fetal complica......The present knowledge of the role of selenium in human fetal and neonatal development is sparse. In this study we measured serum selenium concentrations in maternal and umbilical cord blood from 500 Danish mothers at delivery, looking for a relationship between various maternal and fetal...... complications and selenium values. In mothers with uncomplicated pregnancies and deliveries serum selenium concentrations were 0.84 +/- 0.19 mumol/l (mean +/- SD), whereas in cord blood from full-term babies born adequate for gestational age and with no malformations serum selenium concentrations were 0...

Clinically relevant strategies for lowering cardiomyocyte glucose uptake for {sup 18}F-FDG imaging of myocardial inflammation in mice

Energy Technology Data Exchange (ETDEWEB)

Thackeray, James T.; Bankstahl, Jens P.; Bengel, Frank M. [Hanover Medical School, Department of Nuclear Medicine, Hanover (Germany); Wang, Yong; Wollert, Kai C. [Hanover Medical School, Department of Cardiology and Angiology, Hanover (Germany)

2015-04-01

Myocardial inflammation is an emerging target for novel therapies and thus for molecular imaging. Positron emission tomography (PET) with {sup 18}F-fluorodeoxyglucose (FDG) has been employed, but requires an approach for suppression of cardiomyocyte uptake. We tested clinically viable strategies for their suitability in mouse models in order to optimize preclinical imaging protocols. C57BL/6 mice (n = 56) underwent FDG PET under various conditions. In healthy animals, the effect of low-dose (5 units/kg) or high-dose (500 units/kg, 15 min prior) intravenous heparin, extended fasting (18 h) and the impact of conscious injection with limited, late application of isoflurane anaesthesia after 40 min of conscious uptake were examined in comparison to ketamine/xylazine anaesthesia. Conscious injection/uptake strategies were further evaluated at 3 days after permanent coronary artery occlusion. Under continuous isoflurane anaesthesia, neither heparin administration nor extended fasting significantly impacted myocardial {sup 18}F-FDG accumulation. Injection with 40 min uptake in awake mice resulted in a marked reduction of global myocardial {sup 18}F-FDG uptake compared to standard isoflurane anaesthesia (5.7 ± 1.1 %ID/g vs 30.2 ± 7.9 %ID/g, p < 0.01). Addition of heparin and fasting further reduced uptake compared to conscious injection alone (3.8 ± 1.5 %ID/g, p < 0.01) similar to ketamine/xylazine (2.4 ± 2.2 %ID/g, p < 0.001). In the inflammatory phase, 3 days after myocardial infarction, conscious injection/uptake with and without heparin/fasting identified a marked increase in myocardial {sup 18}F-FDG accumulation that was similar to that observed under ketamine/xylazine. Continuous isoflurane anaesthesia obscures any suppressive effect of heparin or fasting on cardiomyocyte glucose utilization. Conscious injection of FDG in rodents significantly reduces cardiomyocyte uptake and enables further suppression by heparin and fasting, similar to clinical observations. In

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

Science.gov (United States)

Yan, Lin; Johnson, LuAnn K

2011-06-08

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

Novel selenium-doped hydroxyapatite coatings for biomedical applications.

Science.gov (United States)

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

2013-03-01

Nowadays there is a short-term need of investigating in orthopedic implants with a greater functionality, including an improved osseointegration and also antibacterial properties. The coating of metallic implants with hydroxyapatite (HA) remains to be the main proposal, but superior quality HA coatings with compositions closer to natural bone apatites, including carbonates, trace elements are required. Selenium is an essential nutrient in biological tissues and, at the same time, it also presents antibacterial properties. A pioneering study on the fabrication of selenium-doped carbonated hydroxyapatite (iHA:Se) coatings by Pulsed Laser Deposition (PLD) is presented. Different proportions of selenium were incorporated to obtain the iHA:Se coatings. Their physicochemical characterization, performed by SEM/EDS, FTIR, FT-Raman, Interferometric Profilometry and XPS, revealed typical columnar growth of HA in globular aggregates and the efficient incorporation of selenium into the HA coatings by the, most probably, substitution of SeO(3)(2-) groups in the CO(3)(2-) sites. Biological evaluation illustrated the absence of cytotoxicity when an amount of 0.6 at.% of Se was added to the iHA:Se coatings and excellent proliferation of the MC3T3-E1 preosteoblasts. Antibacterial properties were also proved with the inhibition of P. aeruginosa and S. aureus from establishing bacterial biofilms. Copyright © 2012 Wiley Periodicals, Inc.

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

Directory of Open Access Journals (Sweden)

Hetland Harald

2007-10-01

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

Accumulation of selenium in aquatic systems downstream of a uranium mining operation in northern Saskatchewan, Canada

International Nuclear Information System (INIS)

Muscatello, J.R.; Belknap, A.M.; Janz, D.M.

2008-01-01

The objective of this study was to investigate the accumulation of selenium in lakes downstream of a uranium mine operation in northern Saskatchewan, Canada. Selenium concentrations in sediment and biota were elevated in exposure areas even though water concentrations were low (<5 μg/L). The pattern (from smallest to largest) of selenium accumulation was: periphyton < plankton and filterer invertebrates < detritivore and predator invertebrates < small bodied (forage) fish and predatory fish. Biomagnification of selenium resulted in an approximately 1.5-6 fold increase in the selenium content between plankton, invertebrates and forage fish. However, no biomagnification was observed between forage fish and predatory fish. Selenium content in organisms from exposure areas exceeded the proposed 3-11 μg/g (dry weight) dietary toxicity threshold for fish, suggesting that the selenium released into these aquatic systems has the potential to bioaccumulate and reach levels that could impair fish reproduction. - Selenium bioaccumulation patterns in a north temperate, cold water aquatic ecosystem were similar to those reported from warm water systems

Pigmentation, anesthesia, behavioral factors, and salicylate uptake.

Science.gov (United States)

Jastreboff, P J; Issing, W; Brennan, J F; Sasaki, C T

1988-02-01

In four experiments, 54 pigmented rats were used to examine the time course of sodium salicylate uptake in serum, cerebrospinal fluid, and perilymph. Subjects were tested under sodium pentobarbital anesthesia or while conscious. Compared with previously reported data from albino rats, pigmented subjects generally showed increased salicylate uptake. Moreover, the data suggested two different, time-dependent clearance mechanisms in conscious animals not observed in anesthetized rats. Daily injections of salicylate did not produce an accumulation of salicylate in serum. Systematically higher levels of salicylate were observed in perilymph compared with cerebrospinal fluid. Behavioral procedures, including water deprivation and conditioned suppression of ongoing drinking levels, had no effect on salicylate levels.

Relationship of dietary intake of fish and non-fish selenium to serum lipids in Japanese rural coastal community.

Science.gov (United States)

Miyazaki, Yukiko; Koyama, Hiroshi; Nojiri, Masami; Suzuki, Shosuke

2002-01-01

Several studies have suggested that dietary selenium deficiency may be associated with an increased risk of coronary heart disease (CHD). In the present study, 55 men and 71 women were selected from participants in a health examination in a rural coastal community in Japan. The mean dietary selenium intake calculated from the simple food frequency questionnaire (SFFQ) was 127.5 micrograms/day. Fish was the major source of dietary selenium and it contributed to 68.7% of the daily total. HDL cholesterol was higher in the middle selenium intake group and in the high selenium intake group than in the low selenium intake group in all subjects and for males, and a significant difference was found between the middle selenium intake group and the low selenium intake group. The atherogenic index was significantly higher in the low selenium intake group than in the middle selenium intake group and in the high selenium intake group in males. GPx activity, total cholesterol and triacylglycerols did not show any significant differences among the three different selenium intake groups. Dietary intake of non-fish Se had a positive correlation with HDL cholesterol, and an inverse correlation with the atherogenic index in all subjects and for females. On the other hand, dietary intake of fish-Se had no relationship with any serum lipids. Non-fish Se is an important factor in selenium status for the prevention of CHD.

The Effect of Red Pepper Waste Added to Compost on Selenium Content of Pleurotus citrinopileatus Singer

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Fatih Kalyoncu

2016-03-01

Full Text Available In this study, selenium levels of P.citrinopileatus added different rates of red pepper waste to compost as a source of selenium were determined. For this purpose, six different compost groups were prepared and inoculated with P.citrinopileatus mycelia. Selenium levels of harvested mushrooms were analysed. In conclusion, 0.338 µg/g selenium were determined in one gram dry mushroom that red pepper waste added to compost at 5%. Mycelia growth and selenium accumulation were negatively affected by higher rates of red pepper waste.

Soil-applied zinc and copper suppress cadmium uptake and improve the performance of cereals and legumes.

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Murtaza, Ghulam; Javed, Wasim; Hussain, Amir; Qadir, Manzoor; Aslam, Muhammad

2017-02-01

The present study aimed to evaluate the effect of soil-applied Zn and Cu on absorption and accumulation of Cd applied through irrigation water in legume (chickpea and mung bean) and cereal (wheat and maize) crops. The results revealed that Cd in irrigation water at higher levels (2 and 5 mg L -1 ) significantly (p soil application of Zn and Cu, singly or combined, favored the biomass production. Plant tissue Cd concentration increased linearly with the increasing application of Cd via irrigation water. While Cd application caused a redistribution of metals in grains, straw, and roots with the highest concentration of Cd, Zn, and Cu occurred in roots followed by straw and grains. Zinc addition to soil alleviated Cd toxicity by decreasing Cd concentration in plant tissues due to a possible antagonistic effect. The addition of Cu to the soil had no consistent effects on Zn and Cd contents across all crops. Inhibitory effects of Cd on the uptake and accumulation of Zn and Cu have also been observed at higher Cd load. Thus, soil-applied Zn and Cu antagonized Cd helping the plant to cope with its toxicity and suppressed the toxic effects of Cd in plant tissues, thus favoring plant growth.

Distribution of Iodine and Selenium in Selected Food Commodities

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Strapáč I.

2016-03-01

Full Text Available The aim of this study was to investigate the distribution of the contents of iodine and selenium in selected food commodities. Fresh food commodities were mineralized and analysed for their iodine and selenium content by Inductively Coupled Plasma-Mass Spectrometry using the calibration curve as the method for determining the contents of the elements. The average fruit and vegetables concentrations of iodine were very low. The cow’s milk, other dairy products, eggs, poultry, fresh water fish, beef, liver, and mushrooms are frequently regarded as the most important natural source of dietary iodine from common foods. The higher concentrations of selenium were recorded in the kidney, liver, pork, beef, poultry, fresh water fish, hen’s eggs, cow’s milk, other dairy products, wheat flour, fats, coffee, peppers, mushrooms and potatoes.

Deposition of selenium coatings on beryllium foils. Revision 1

International Nuclear Information System (INIS)

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

1984-01-01

A technique for preparing selenium films on 50.8 micrometers thick beryllium foils is described. The selenium was deposited in vacuum from a resistance heated evaporation source. A water-cooled enclosure was used to minimize contamination of the vacuum system and to reduce the exposure of personnel to toxic and obnoxious materials. Profilometry measurements of the coatings indicated selenium thicknesses of 5.5, 12.9, 37.5, 49.8 and 74.5 micrometers. The control of deposition rate and of coating thickness was facilitated using a commercially available closed-loop programmable deposition controller. The x-ray transmission of the coated substrates was measured using a tritiated zirconium source. The transmissivities of the film/substrate combination are presented for the range of energies from 4 to 20 keV

Optimised selenium enrichment of Artemia sp. feed to improve red drum (Sciaenops ocellatus) larvae rearing.

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Juhász, Péter; Lengyel, Szvetlana; Udvari, Zsolt; Sándor, Alex Nagy; Stündl, László

2017-09-01

Selenium is an essential microelement for the normal functioning of life processes. Moreover, it is a component of enzymes with antioxidant effects. However, it has the smallest window of any micronutrient between requirement and toxicity. Selenium is a regularly used element in fish feeds; moreover, enriching zooplankton with selenium to rear larvae is also a well-known technology. It is accepted that the most common starter foods of fish larvae, natural rotifers contain the smallest dosage of selenium, but providing selenium enriched Artemia sp. instead could increase survival and growth rate of fish. However, no such references are available for the red drum (Sciaenops ocellatus) larvae. Therefore, in this study, Artemia sp. was enriched with nano-selenium of verified low toxicity and easy availability in 5 treatments (1, 5, 10, 50, 100 mg/l Se), and then, fish larvae were fed with four of these enriched Artemia stocks (1, 5, 10, 50 mg/l Se) and a control group. At the end of the 9-day-long experiment, survival rate (S) and growth parameters (SL, W, K-factor, SGR) of fish larvae were calculated as well as their selenium retention and glutathione peroxidase enzyme activity were analysed. It was revealed that a moderate level of selenium enrichment (~4 mg/kg dry matter) of Artemia sp. positively influences the rearing efficiency (i.e. survival and growth) of fish larvae, but higher dosages of selenium could cause adverse effects.

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

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

2017-12-01

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

The Evolving Role of Selenium in the Treatment of Graves' Disease and Ophthalmopathy

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Leonidas H. Duntas

2012-01-01

Full Text Available Graves' disease (GD and ophthalmopathy (GO are organ-specific autoimmune-inflammatory disorders characterized by a complex pathogenesis. The inflammatory process is dominated by an imbalance of the antioxidant-oxidant mechanism, increased production of radical oxygen species (ROS, and cytokines which sustain the autoimmune process and perpetuate the disease. Recently, selenium, which is a powerful antioxidant, has been successfully applied in patients with mild GO, slowing the progression of disease, decreasing the clinical activity score, and appreciably improving the quality of life. The mechanisms of selenium action are variable. The aim of this review is to summarize the actions of selenium in GD and GO. Selenium as selenocysteine is incorporated in selenoproteins, such as glutathione peroxidase which catalyzes the degradation of hydrogen peroxide and lipid hydroperoxide that are increasingly produced in hyperthyroidism. Moreover, selenium decreases the formation of proinflammatory cytokines, while it contributes, in synergy with antithyroid drugs, to stabilization of the autoimmune process in GD and alleviation of GO. It is now to be clarified whether enforced nutritional supplementation has the same results and whether prolonging selenium administration may have an impact on the prevention of disease.

In-vitro use of radiominerals to determine mineral imbalances in farm animals. Part of a coordinated programme on the use of isotopes to diagnose moderate mineral imbalances in farm animals

International Nuclear Information System (INIS)

Goksoy, K.

1981-01-01

This research programme involved the use of in vitro radioisotopic procedures as well as stable element analysis and enzyme determinations to evaluate selenium, copper and zinc deficiency states in sheep in Turkey. Uptake of radioactive selenium by red blood cells was effective in determining the selenium status of sheep. Animals on a selenium deficient diet had red cell selenium uptakes significantly greater than those of sheep fed normal levels of selenium. When sheep on a selenium deficient diet were tested and then supplemented with selenium for several weeks, the red cell uptakes of radioselenium after supplementation were significantly less than before supplementation. A similar technique was used to study the zinc status of sheep. Uptake of radioactive zinc by red cells was greater in deficient sheep than in zinc-supplemented animals. Zinc deficient sheep also had lower serum zinc levels than in supplemented animals, and alkaline phosphatase activity levels. Assays of erythrocyte uptake, using a scintillation counter may be useful in the absence of equipment for total mineral analysis or enzyme assays. In another study the serum copper levels of sheep of different genetic types were compared to serum ceruloplasmin levels and to the incidence of enzootic ataxia in offspring of these animals. A definite correlation was found between haemoglobulin type, serum copper level and ceruloplasmin level. Comparisons of these parameters in sheep with copper and molybdenum levels in forage samples indicated that copper deficiency in sheep in Turkey is apparently a secondary copper deficiency due to high levels of molybdenum in forage

Effectiveness of 131I nor-cholesterol uptake per unit volume of adrenal adenoma in the diagnosis of aldosteronoma

International Nuclear Information System (INIS)

Kita, Tamotsu; Tomita, Hiroko; Sakaguchi, Chiharu

2010-01-01

Diagnosis of adrenal adenomas for patients with primary aldosteronism is sometimes difficult only by referring to the visualization pattern in adrenocortical scintigraphy without regards to standard scintigraphy or suppression scintigraphy with dexamethasone. We studied if quantitative evaluation of the standard scintigraphy without dexamethasone suppression can be useful to diagnose aldosteronomas. Twenty-nine patients who had undergone adrenalectomy with different clinical manifestations (16 patients with primary aldosteronism, 6 patients with Cushing's syndrome and 7 patients without hormonal abnormality) were included in the study. Volume of the adrenocortical adenomas, 131 I nor-cholesterol uptake of the adrenocortical adenomas, and 131 I nor-cholesterol uptake per unit volume of the adrenocortical adenomas were compared between the 3 groups. The volume of adrenocortical adenomas in the patients with primary aldosteronism was significantly lower than those in the other two groups (Cushing's syndrome p 131 I nor-cholesterol uptake of adrenocortical adenoma. The 131 I nor-cholesterol uptake per unit volume of adrenocortical adenomas was significantly higher in the patients with primary aldosteronism than those in the other two groups (Cushing's syndrome p 131 I nor-cholesterol uptake per unit volume of adenoma obtained from adrenocortical scintigraphy without dexamethasone suppression can be useful in the diagnosis of aldosteronoma. (author)

Selenium prevents tumor development in a rat model for chemical carcinogenesis

DEFF Research Database (Denmark)

Bjorkhem-Bergman, L.; Torndal, U. B.; Eken, S.

2005-01-01

Previous studies in animals and humans have shown that selenium compounds can prevent cancer development. In this work we studied the tumor preventive effect of selenium supplementation, administrated as selenite, in the initiation, promotion and progression phases in a synchronized rat model for...

Ameliorative effects of selenium and zinc

African Journals Online (AJOL)

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

Low selenium status affects arsenic metabolites in an arsenic exposed population with skin lesions.

Science.gov (United States)

Huang, Zhi; Pei, Qiuling; Sun, Guifan; Zhang, Sichum; Liang, Jiang; Gao, Yi; Zhang, Xinrong

2008-01-01

The antagonistic effects between selenium (Se) and arsenic (As) suggest that low selenium status plays important roles in arsenism development. However, no study has been reported for humans suffering from chronic arsenic exposure with low selenium status. Sixty-three subjects were divided into 2 experimental groups by skin lesions (including hyperkeratosis, depigmentation, and hyperpigmentation). Total urine and serum concentrations of arsenic and selenium were determined by ICP-MS with collision/reaction cell. Arsenic species were analysed by ICP-MS coupled with HPLC. The mean concentration of As in the drinking waters was 41.5 microg/l. The selenium dietary intake for the studied population was 31.7 microg Se/d, and which for the cases and controls were 25.9 and 36.3 microg Se/d, respectively. Compared with the controls, the skin lesions cases had lower selenium concentrations in serum and urine (41.4 vs 49.6 microg/l and 71.0 vs 78.8 microg/l, respectively), higher inorganic arsenic (iAs) in serum (5.2 vs 3.4 microg/l, PiAs in serum and urine (20.2) vs 16.9% and 18.3 vs 14.5%, respectively, PiAs and its inhibition to be biotransformed to DMA occurred in human due to chronic exposure of low selenium status.

Mercury and selenium in blue shark (Prionace glauca, L. 1758) and swordfish (Xiphias gladius, L. 1758) from two areas of the Atlantic Ocean

Energy Technology Data Exchange (ETDEWEB)

Branco, Vasco [National Institute for Agronomy and Fisheries Research (INIAP/IPIMAR), Avenida de Brasilia, 1449-006 Lisbon (Portugal)], E-mail: vbranco@ipimar.pt; Vale, Carlos; Canario, Joao [National Institute for Agronomy and Fisheries Research (INIAP/IPIMAR), Avenida de Brasilia, 1449-006 Lisboa (Portugal); Santos, Miguel Neves dos [National Institute for Agronomy and Fisheries Research (INIAP/IPIMAR), South Regional Center for Fisheries Research (IPIMAR/CRIPSul), Avenida 5 de Outubro s/n, 8700-305 Olhao (Portugal)

2007-12-15

Muscle, liver and stomach contents of 64 blue sharks and 52 swordfishes, caught between September 2004 and February 2005 near the Azores (area A) and the Equator (area E), were analysed for mercury and selenium. Levels of mercury were relatively high (blue shark: 0.032-2.5 {mu}g g{sup -1}; swordfish: 0.031-9.8 {mu}g g{sup -1}) and comparable to values reported in the literature. However, mercury and organic mercury concentrations in muscle and liver of specimens from E were significantly higher than those from A. A similar trend was registered in stomach contents, suggesting higher uptake of Hg in specimens from E. This difference was also observed in the relationship between concentration in muscle and size, indicating a higher accumulation rate in specimens from E. The accumulation of Se in the liver of both species showed a positive correlation with inorganic mercury concentrations, pointing to a detoxifying mechanism of organic mercury in these species through Se-Hg liaisons. - Mercury levels differ in Azores and Equator, and detoxification by selenium occurs.

Mercury and selenium in blue shark (Prionace glauca, L. 1758) and swordfish (Xiphias gladius, L. 1758) from two areas of the Atlantic Ocean

International Nuclear Information System (INIS)

Branco, Vasco; Vale, Carlos; Canario, Joao; Santos, Miguel Neves dos

2007-01-01

Muscle, liver and stomach contents of 64 blue sharks and 52 swordfishes, caught between September 2004 and February 2005 near the Azores (area A) and the Equator (area E), were analysed for mercury and selenium. Levels of mercury were relatively high (blue shark: 0.032-2.5 μg g -1 ; swordfish: 0.031-9.8 μg g -1 ) and comparable to values reported in the literature. However, mercury and organic mercury concentrations in muscle and liver of specimens from E were significantly higher than those from A. A similar trend was registered in stomach contents, suggesting higher uptake of Hg in specimens from E. This difference was also observed in the relationship between concentration in muscle and size, indicating a higher accumulation rate in specimens from E. The accumulation of Se in the liver of both species showed a positive correlation with inorganic mercury concentrations, pointing to a detoxifying mechanism of organic mercury in these species through Se-Hg liaisons. - Mercury levels differ in Azores and Equator, and detoxification by selenium occurs

The APOE ε4 Allele Is Associated with Lower Selenium Levels in the Brain: Implications for Alzheimer's Disease.

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R Cardoso, Bárbara; Hare, Dominic J; Lind, Monica; McLean, Catriona A; Volitakis, Irene; Laws, Simon M; Masters, Colin L; Bush, Ashley I; Roberts, Blaine R

2017-07-19

The antioxidant activity of selenium, which is mainly conferred by its incorporation into dedicated selenoproteins, has been suggested as a possible neuroprotective approach for mitigating neuronal loss in Alzheimer's disease. However, there is inconsistent information with respect to selenium levels in the Alzheimer's disease brain. We examined the concentration and cellular compartmentalization of selenium in the temporal cortex of Alzheimer's disease and control brain tissue. We found that Alzheimer's disease was associated with decreased selenium concentration in both soluble (i.e., cytosolic) and insoluble (i.e., plaques and tangles) fractions of brain homogenates. The presence of the APOE ε4 allele correlated with lower total selenium levels in the temporal cortex and a higher concentration of soluble selenium. Additionally, we found that age significantly contributed to lower selenium concentrations in the peripheral membrane-bound and vesicular fractions. Our findings suggest a relevant interaction between APOE ε4 and selenium delivery into brain, and show changes in cellular selenium distribution in the Alzheimer's disease brain.

The Effect of Ketogenic Diet on Serum Selenium Levels in Patients with Intractable Epilepsy.

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Arslan, Nur; Kose, Engin; Guzel, Orkide

2017-07-01

The aim of the present study was to evaluate serum selenium levels in children receiving olive oil-based ketogenic diet (KD) for intractable seizures for at least 1 year. Out of 320 patients who were initiated on KD, patients who continued receiving KD for at least 12 months were enrolled. Sixteen patients who had selenium deficiency at the time of starting KD were excluded. Finally, a total of 110 patients (mean age 7.3 ± 4.2 years) were included. Serum selenium levels were measured at baseline and at 3, 6, and 12 months after treatment initiation by using atomic absorption spectroscopy. Selenium deficiency was defined as a serum selenium level ketogenic diet suggests that patients on this highly prescriptive dietary treatment need close monitoring of this trace element.

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

Science.gov (United States)

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

2013-01-01

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

Selenium in the upper Blackfoot River watershed, southeastern Idaho, 2001-12

Science.gov (United States)

Mebane, Christopher A.; Mladenka, Greg; Van Every, Lynn; Williams, Marshall L.; Hardy, Mark A.; Garbarino, John R.

2014-11-05

The upper Blackfoot River in southeastern Idaho receives runoff from 12 large phosphate mines. Waste shales that are removed to access the phosphate ore are highly enriched with selenium, resulting in elevated selenium in runoff from the mine waste dumps. In 2001, in cooperation with the Bureau of Land Management, the U.S. Geological Survey (USGS) began monitoring streamflow, selenium, and other water-quality parameters at a single location near the outlet of the upper Blackfoot River to the Blackfoot Reservoir. Water samples primarily were collected by a flow triggered, automated pump sampler, supplemented by manual point and equal-width integrated manual samples.

Plasma Selenium Concentrations Are Sufficient and Associated with Protease Inhibitor Use in Treated HIV-Infected Adults123

Science.gov (United States)

Hileman, Corrilynn O; Dirajlal-Fargo, Sahera; Lam, Suet Kam; Kumar, Jessica; Lacher, Craig; Combs, Gerald F; McComsey, Grace A

2015-01-01

Background: Selenium is an essential constituent of selenoproteins, which play a substantial role in antioxidant defense and inflammatory cascades. Selenium deficiency is associated with disease states characterized by inflammation, including cardiovascular disease (CVD). Although HIV infection has been associated with low selenium, the role of selenium status in HIV-related CVD is unclear. Objectives: We sought to assess associations between plasma selenium and markers of inflammation, immune activation, and subclinical vascular disease in HIV-infected adults on contemporary antiretroviral therapy (ART) and to determine if statin therapy modifies selenium status. Methods: In the Stopping Atherosclerosis and Treating Unhealthy bone with RosuvastatiN trial, HIV-infected adults on stable ART were randomly assigned 1:1 to rosuvastatin or placebo. Plasma selenium concentrations were determined at entry, week 24, and week 48. Spearman correlation and linear regression analyses were used to assess relations between baseline selenium, HIV-related factors and markers of inflammation, immune activation, and subclinical vascular disease. Changes in selenium over 24 and 48 wk were compared between groups. Results: One hundred forty-seven HIV-infected adults were included. All participants were on ART. Median current CD4+ count was 613, and 76% had HIV-1 RNA ≤48 copies/mL (range: selenium concentration was 122 μg/L (range: 62–200). At baseline, higher selenium was associated with protease inhibitor (PI) use, lower body mass index, and a higher proportion of activated CD8+ T cells (CD8+CD38+human leukocyte antigen-DR+), but not markers of inflammation or subclinical vascular disease. Over 48 wk, selenium concentrations increased in the statin group (P selenium concentrations were within the normal range for the background population and were not associated with subclinical vascular disease in HIV-infected adults on contemporary ART. The association between current PI use

Epigallocatechin-3-gallate enhances key enzymatic activities of hepatic thioredoxin and glutathione systems in selenium-optimal mice but activates hepatic Nrf2 responses in selenium-deficient mice

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Ruixia Dong

2016-12-01

Full Text Available Selenium participates in the antioxidant defense mainly through a class of selenoproteins, including thioredoxin reductase. Epigallocatechin-3-gallate (EGCG is the most abundant and biologically active catechin in green tea. Depending upon the dose and biological systems, EGCG may function either as an antioxidant or as an inducer of antioxidant defense via its pro-oxidant action or other unidentified mechanisms. By manipulating the selenium status, the present study investigated the interactions of EGCG with antioxidant defense systems including the thioredoxin system comprising of thioredoxin and thioredoxin reductase, the glutathione system comprising of glutathione and glutathione reductase coupled with glutaredoxin, and the Nrf2 system. In selenium-optimal mice, EGCG increased hepatic activities of thioredoxin reductase, glutathione reductase and glutaredoxin. These effects of EGCG appeared to be not due to overt pro-oxidant action because melatonin, a powerful antioxidant, did not influence the increase. However, in selenium-deficient mice, with low basal levels of thioredoxin reductase 1, the same dose of EGCG did not elevate the above-mentioned enzymes; intriguingly EGCG in turn activated hepatic Nrf2 response, leading to increased heme oxygenase 1 and NAD(PH:quinone oxidoreductase 1 protein levels and thioredoxin activity. Overall, the present work reveals that EGCG is a robust inducer of the Nrf2 system only in selenium-deficient conditions. Under normal physiological conditions, in selenium-optimal mice, thioredoxin and glutathione systems serve as the first line defense systems against the stress induced by high doses of EGCG, sparing the activation of the Nrf2 system.

Cathodic electrodeposition of amorphous elemental selenium from an air- and water-stable ionic liquid.

Science.gov (United States)

Redman, Daniel W; Murugesan, Sankaran; Stevenson, Keith J

2014-01-14

Electrodeposition of selenium from 1-propyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide is reported. In situ UV-vis spectroelectrochemistry was used to investigate the reduction of diethyl selenite to form elemental selenium thin films from an ionic liquid-acetonitrile medium. Three reduction peaks of diethyl selenite were observed via cyclic voltammetry and are attributed to the stepwise reduction of the selenium precursor adsorbed on the electrode. The electrodeposition mechanism is influenced by both potential and time. Electrodeposition at -1.7 V vs Pt QRE resulted in the deposition of elemental selenium nanoparticles that with time coalesced to form a continuous film. At reduction potentials more negative than -1.7 V the morphology of the deposit changed significantly due to the reduction of elemental Se to Se(2-). In addition, p-type photoconductivity of the films was observed during the spectroelectrochemical measurements. X-ray diffraction and Raman spectroscopy confirmed that the deposited selenium films were amorphous. X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy confirm the films consisted of pure selenium with minor residual contamination from the precursor and ionic liquid.

Derivation of site-specific selenium criteria for a Kentucky stream receiving fly ash effluent

International Nuclear Information System (INIS)

Reash, R.J.; Van Hassel, J.H.

1993-01-01

Blaine Creek, a fifth-order tributary to the Big Sandy River in eastern Kentucky, receives fly ash effluent from Kentucky Power Company's Big Sandy Plant fly ash pond near the creek's mouth. Long-term biosurvey/physicochemical data and speciation studies were used to derive proposed site-specific selenium water quality criteria. Biosurvey results from 1982--1990 were consistent in showing no adverse effects of fly ash discharge, even during low flow conditions when the effluent comprised 75% of creek flow. Five macroinvertebrate parameters (taxa richness, total abundance, EPT taxa, number caddisflies and chironomids) were significantly correlated with % effluent, indicating enhanced communities at high instream waste concentrations. Several fish metrics similarly showed greater enhancement at high % effluent conditions. Selenium speciation studies indicated that selenite (Se 4+ ) represented 100% of total selenium in the effluent. Total selenium concentrations were low at fully mixed downstream reaches. US EPA's Recalculation Procedure was used to calculate site-specific selenium criteria based on Se 4+ toxicity data for resident species. These criteria are higher than statewide criteria which are based on selenium, effects at waterbodies having low turnover rates

Selenium, Selenoprotein Genes and Crohn’s Disease in a Case-Control Population from Auckland, New Zealand

Science.gov (United States)

Gentschew, Liljana; Bishop, Karen S.; Han, Dug Yeo; Morgan, Angharad R.; Fraser, Alan G.; Lam, Wen Jiun; Karunasinghe, Nishi; Campbell, Bobbi; Ferguson, Lynnette R.

2012-01-01

New Zealand has one of the highest incidence rates of Crohn’s Disease (CD), whilst the serum selenium status of New Zealanders is amongst the lowest in the world. A prospective case-control study in Auckland, New Zealand considered serum selenium as a potential CD risk factor. Serum selenium levels were significantly lower in CD patients compared to controls (101.8 ± 1.02 vs. 111.1 ± 1.01 ng/mL) (p = 5.91 × 10−8). Recent detailed studies in the United Kingdom have suggested an optimal serum level around 122 ng/mL, making the average CD patient in New Zealand selenium deficient. Of the 29 single nucleotide polymorphisms (SNPs) tested, 13 were found to significantly interact with serum selenium on CD. After adjustment for multiple testing, a significant interaction with serum selenium on CD was found for three SNPs, namely rs17529609 and rs7901303 in the gene SEPHS1, and rs1553153 in the gene SEPSECS. These three SNPs have not been reported elsewhere as being significantly associated with selenium or CD. It is unclear as to whether lower selenium levels are a cause or an effect of the disease. PMID:23112913

Effect of gamma irradiation, evaporation retardants and transpiration suppressants on grain yield, nutrient uptake and moisture-use efficiency on bread wheat (Triticum aestivum)

International Nuclear Information System (INIS)

Dash, D.K.; Sen, Avijit; Misra, N.M.

1988-01-01

A field trial was conducted on 'Malaviya 37' bread wheat (Triticum aestivum Linn. emend. Fiori and Paol.) in 1982-83 and 1983-84. It included 4 dos es of gamma irradiation of seeds (0, 2.5, 4.5 and 6.5 kR) and 5 treatments of evaporation retardants and transpiration suppressants, viz. control, rice (Oryza sativa Linn.) straw, wheat straw, rice straw + phenyl mercuric acetate (150 ppm) and wheat straw + kaolin (6 per cent). Seed irradiation with gamma-rays at 6.5 kR and wheat straw + kaolin gave 11.76 and 61.37 per cent higher yield than the control respectively. For moisture-use efficiency and NPK uptake these treatments also showed the same trend. (author). 12 refs

Maternal selenium status during early gestation and risk for preterm birth

NARCIS (Netherlands)

Rayman, M.P.; Wijnen, H.A.; Vader, H.; Kooistra, L.; Pop, V.

2011-01-01

Background Preterm birth occurs in 5%-13% of pregnancies. It is a leading cause of perinatal mortality and morbidity and has adverse long-term consequences for the health of the child. Because of the role selenium plays in attenuating inflammation, and because low concentrations of selenium have

Maternal selenium status during early gestation and risk for preterm birth

NARCIS (Netherlands)

Rayman, Margaret P.; Wijnen, Hennie; Vader, Huib; Kooistra, Libbe; Pop, Victor

2011-01-01

Background: Preterm birth occurs in 5%-13% of pregnancies. It is a leading cause of perinatal mortality and morbidity and has adverse long-term consequences for the health of the child. Because of the role selenium plays in attenuating inflammation, and because low concentrations of selenium have

Selenium-Enriched Foods Are More Effective at Increasing Glutathione Peroxidase (GPx) Activity Compared with Selenomethionine: A Meta-Analysis

Science.gov (United States)

Bermingham, Emma N.; Hesketh, John E.; Sinclair, Bruce R.; Koolaard, John P.; Roy, Nicole C.

2014-01-01

Selenium may play a beneficial role in multi-factorial illnesses with genetic and environmental linkages via epigenetic regulation in part via glutathione peroxidase (GPx) activity. A meta-analysis was undertaken to quantify the effects of dietary selenium supplementation on the activity of overall GPx activity in different tissues and animal species and to compare the effectiveness of different forms of dietary selenium. GPx activity response was affected by both the dose and form of selenium (p selenium supplementation on GPx activity (p selenium supply include red blood cells, kidney and muscle. The meta-analysis identified that for animal species selenium-enriched foods were more effective than selenomethionine at increasing GPx activity. PMID:25268836

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

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

2017-08-01

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

Dietary habits and selenium intake of residents in mountain and coastal communities in Japan.

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Miyazaki, Yukiko; Koyama, Hiroshi; Sasada, Yoko; Satoh, Hiroshi; Nojiri, Masami; Suzuki, Shosuke

2004-10-01

We used a Simple Food Frequency Questionnaire (SFFQ) in combination with other dietary approaches to estimate the selenium intake from different food groups based on the average long-term diet, in two rural communities in Japan, one in a mountain area and the other in a coastal area. The intake frequencies of rice and wheat products were significantly different in the two districts. The intake frequencies of fish, meat, and eggs, which are rich in selenium, were not significantly different. The mean dietary selenium intake, estimated from the SFFQ and the 24-h recall method, was 82.7 microg/d (n=234) (range 19.2-180.1 microg/d) in the mountain community. The mean dietary selenium intake estimated from the SFFQ and average value of the normal portion size was 118.0 microg/d (n=123) (range 22.6-255.3 microg/d) in the coastal community. These estimated mean values exceeded the Japanese RDA, although the range of daily selenium intake was large. In the mountain community, fish made the largest contribution to dietary selenium intake (48.2% of daily total), followed by eggs (24.3%), and meat (17.0%). In the coastal community, fish accounted for 57.7% of daily total selenium intake, followed by meat (17.5%), and eggs (16.1%). In both districts, the total contribution of rice and wheat products was around 10%. It was found that the contribution of fish to dietary selenium intake was high and the contribution of cereals was low among Japanese.

Antioxidant activity of water extracts from fruit body of Lentinus edodes enriched with selenium

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Savić Milena D.

2011-01-01

Full Text Available Shiitake (Lentinus edodes belongs to medically important and delicious fungi. It is recognizable for its healing properties, excellent taste and rich aroma. According to the traditional Japanese and Chinese medicine, shiitake mushroom significantly increases the strength and vitality of the body. Shiitake contains immunostimulants, compounds that lower cholesterol, prevents clogging of blood vessels, regulates the pressure, balances blood sugar levels, regulates digestion, and improves the performance of respiratory organs by its antirheumatic and antiallergic activities. Shiitake is recommended to use as food, prevention and cure, usually in a form of a spice (dried and ground or tea. It can be consumed fresh, too. The objective of this study was to test the effect of enrichment in selenium on antioxidant, reducing and free radical scavenging activity of water extracts from fruit body of Lentinus edodes. The fungus was enhanced by adding organic selenium, zinc (II complex with the ligand 2.6-bis diacetylpyridine (selenosemicarbazon and inorganic compounds (Na2SeO3 of selenium in nutritional substrate where the fungus was grown. The total selenium content in fruit body was around 50 ppm for the sample enriched with selenium originating from organic sources, and 80 ppm for the sample enriched with selenium from inorganic sources. Samples were prepared by extraction of fruiting bodies in heated water. The results indicated that water extracts of whole fruit bodies, from both control and mushrooms supplemented with selenium, had quite good antioxidant activity. However, there was no significant difference between the samples supplemented with selenium content and those that were not.

BLOOD SELENIUM CONCENTRATION AFFECT MASTITIS AND MILK QUALITY IN DAIRY COWS

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Davidov Ivana

2013-02-01

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

Optimal serum selenium concentrations are associated with lower depressive symptoms and negative mood among young adults.

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Conner, Tamlin S; Richardson, Aimee C; Miller, Jody C

2015-01-01

There is evidence that low, and possibly high, selenium status is associated with depressed mood. More evidence is needed to determine whether this pattern occurs in young adults with a wide range of serum concentrations of selenium. The aim of this study was to determine if serum selenium concentration is associated with depressive symptoms and daily mood states in young adults. A total of 978 young adults (aged 17-25 y) completed the Center for Epidemiological Studies-Depression scale and reported their negative and positive mood daily for 13 d using an Internet diary. Serum selenium concentration was determined by inductively coupled plasma mass spectrometry. ANCOVA and regression models tested the linear and curvilinear associations between decile of serum selenium concentration and mood outcomes, controlling for age, gender, ethnicity, BMI, and weekly alcohol intake. Smoking and childhood socioeconomic status were further controlled in a subset of participants. The mean ± SD serum selenium concentration was 82 ± 18 μg/L and ranged from 49 to 450 μg/L. Participants with the lowest serum selenium concentration (62 ± 4 μg/L; decile 1) and, to a lesser extent, those with the highest serum selenium concentration (110 ± 38 μg/L; decile 10) had significantly greater adjusted depressive symptoms than did participants with midrange serum selenium concentrations (82 ± 1 to 85 ± 1 μg/L; deciles 6 and 7). Depressive symptomatology was lowest at a selenium concentration of ∼85 μg/L. Patterns for negative mood were similar but more U-shaped. Positive mood showed an inverse U-shaped association with selenium, but this pattern was less consistent than depressive symptoms or negative mood. In young adults, an optimal range of serum selenium between ∼82 and 85 μg/L was associated with reduced risk of depressive symptomatology. This range approximates the values at which glutathione peroxidase is maximal, suggesting that future research should investigate

Suppression of [sup 125]I-uptake in mouse thyroid by seaweed feeding; Possible preventative effect of dietary seaweed on internal radiation injury of the thyroid by radioactive iodine

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Maruyama, Hiroko; Yamamoto, Ichiro (Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Hygienic Sciences)

1992-12-01

We conducted an animal experiment to determine how dietary seaweeds rich in iodine and dietary fibers suppress radioactive iodine uptake by the thyroid, using mice and four kinds of experimental diets, three with 1% or 2% powdered fronds of the kelp Laminaria religiosa and 2% powdered laver Porphyra yezoensis, and one with cellulose. Iodine content of a hot-water extract of the kelp was 0.530[+-]0.001%, and its dietary fiber (DF) values were 52.8[+-]1.2%. Iodine in an extract of the laver was 0.008[+-]0.001%, and its DF values were 41.4%[+-]0.7%. A statistically significant reduction of [sup 125]I uptake by the thyroid, 3 hours after intragastric administration of the radionuclide at a dosage of 18.5 kBq or 185 kBq in 0.3 ml aqueous solution per mouse, was observed in mice previously fed the experimental diets containing 1% and 2% kelp during periods varying from 24 hours to 7 days. The degree of the suppression was observed to depend on the amount of iodine in the diet or in the injected sample, no matter whether organic or inorganic, judging from the results of an additional experiment. Thus, we conclude that previously fed iodine-rich material, especially dietary seaweeds rich in iodine and other minerals, vitamins, and [beta]-carotene, such as kelps or laver supplemented with inorganic iodine, may be effective in prevention of internal radiation injury of the thyroid. (author).

Green synthesis of selenium nanoparticles by excimer pulsed laser ablation in water

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O. Van Overschelde

2013-10-01

Full Text Available Pure selenium nanoparticles were successfully synthesized by Liquid Phase - Pulsed Laser Ablation (LP-PLA in de-ionized water. Excimer laser (248 nm operating at low fluence (F ∼ 1 J/cm2 was used to generate colloidal solutions of selenium nanoparticles. The obtained selenium nanoparticles were characterized by UV-visible spectroscopy, Raman spectroscopy, Dynamic Light Scattering, and Transmission Electron Microscopy. We describe the multi-modal size distributions generated and use the centrifugation method to isolate the smallest nanoparticles (∼60 nm in diameter.

Effect of Selenium Supplementation on Recurrent Hyperthyroidism Caused by Graves' Disease: A Prospective Pilot Study.

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Wang, L; Wang, B; Chen, S R; Hou, X; Wang, X F; Zhao, S H; Song, J Q; Wang, Y G

2016-09-01

The effect of selenium supplementation on recurrent hyperthyroidism caused by Graves' disease is unclear. Our study aimed to assess the efficacy of selenium supplementation therapy on recurrent Graves' disease. Forty-one patients with recurrent Graves' disease were enrolled in this study. All patients received the routine treatment using methimazole (MMI), while patients allocated to the selenium group received additional selenium therapy for 6 months. The influence of selenium supplementation on the concentrations of thyroid stimulating hormone (TSH), anti-TSH-receptor antibodies (TRAb), free thyroxine (FT4), and free triiodothyronine (FT3) were assessed. The remission rate was also compared between 2 groups. There was no obvious difference in the demographic data and the levels of serum FT4, FT3, TSH, and TRAb between the 2 groups at baseline. Both FT4 and FT3 decreased more at 2 months in the selenium group than the controls, while the TSH level increased more in patients receiving selenium supplementation (pGraves' disease. Randomized trials with large number of participants are needed to validate the finding above. © Georg Thieme Verlag KG Stuttgart · New York.

Preparation of selenium coatings onto beryllium foils

International Nuclear Information System (INIS)

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

1984-09-01

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

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

DEFF Research Database (Denmark)

Burney, P; Potts, J; Makowska, J

2008-01-01

BACKGROUND: There is evidence that selenium levels are relatively low in Europe and may be falling. Low levels of selenium or low activity of some of the enzymes dependent on selenium have been associated with asthma. METHODS: The GA(2)LEN network has organized a multicentre case-control study...... in Europe to assess the relation of plasma selenium to asthma. The network compared 569 cases in 14 European centres with a diagnosis of asthma and reporting asthma symptoms in the last 12 months with 576 controls from the same centres with no diagnosis of asthma and no asthmatic symptoms in the last 12......-analysis of the results from the centres showed no overall association between asthma and plasma selenium [odds ratio (OR)/10 microg/l increase in plasma selenium: 1.04; 95% confidence interval (CI): 0.89-1.21] though there was a significantly protective effect in Lodz (OR: 0.48; 95% CI: 0.29-0.78) and a marginally...

Blood selenium content determination by X-ray fluorescence

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Mainardi, R.T.

1987-01-01

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

The influence of selenium and deiodinases blockers on juvenile rats body weight

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Milanović Svetlana

2014-01-01

Full Text Available In this work there was investigated the influence of selenium and deodinases blockers on juvenile rats body weight during three months. The experiment was carried out on 64 rats divided into eight groups with eight individual animals per group. Following groups were formed: 1. Se+PTU-IA- (control group, 2. Se+PTU+IA+, 3. Se+PTU+IA-, 4. Se+PTU- IA+, 5. Se-PTU-IA-, 6. Se-PTU+IA+, 7. Se-PTU+IA- and 8. Se-PTU-IA+. The groups labeled (Se+ were selenium adequate and they were fed with food that contained 0.334 mg Se/kg. The groups labeled (Se- were selenium deficient and obtained food with 0.031 mg Se/kg. As deiodinases blockers there were used propylthiouracil (PTU+ in a dose of 150 mg/L of drinking water and iopanoic acid (IA+ in a dose of 6 mg/100 g TM intraperitoneally. Body weight of experimental rats was measured every seven days. After three weeks of treatment there were taken blood samples of animals from all experimental groups and following parameters were determined: selenium concentration in blood, thyroxine (T4, triiodothyronine (T3 and thyroidstimulating hormone (TSH in blood plasma. Analysis of the samples showed that the animals from the groups treated with PTU had lower body weight in regard to the control group, as well as lower concentration of T3 and T4 in plasma. Selenium deficient rats had lower average body weight compared to the selenium adequate ones after three weeks, but there were no differences in thyroid hormones concentration. The lowest average body weight was noticed in selenium deficient rats groups treated with PTU. [Projekat Ministartsva nauke Republike Srbije, br. TR31050 i br. TR31003

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

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

2012-01-01

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

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

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

2012-09-01

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

Lag and ghosting in a clinical flat-panel selenium digital mammography system

International Nuclear Information System (INIS)

Bloomquist, Aili K.; Yaffe, Martin J.; Mawdsley, Gordon E.; Hunter, David M.; Beideck, Daniel J.

2006-01-01

We present measurements of lag and ghosting in a FDA-approved digital mammography system that uses a dielectric/selenium based detector structure. Lag is the carryover of signal from a previous image, whereas ghosting is the reduction of sensitivity caused by previous exposure history of the detector. Data from six selenium units were acquired. For the type of selenium detector tested, and under typical clinical usage conditions, the lag was as high as 0.15% of source signal and the ghosting could be as high as 15%. The amount of lag and ghosting varied from unit to unit. Results were compared with data acquired on a phosphor-based full-field digital mammography system. Modifications in the technology of the selenium detectors appear to have resulted in a marked decrease in both lag and ghosting effects in more recent systems

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

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

2018-05-17

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

An Assessment of the Selenium Status of Iodine-Deficient and Non-Iodine Deficient Filipino Children

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