Selenium
Its Molecular Biology and Role in Human Health
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Selenium status influences a number of endocrine processes, most notably those involved in thyroid hormone synthesis and metabolism. Thyroid follicular cells maintain a highly oxidative environment as required...
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Selenium appears to have a multifactorial role in HIV-1 infection. Selenium status affects HIV disease progression and mortality [1] through various potential mechanisms. Selenium protects against oxidative st...
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UGA has a dual role in the genetic code serving as a signal for termination and a codon for selenocysteine (Sec). Sec appears to have been added to the already existing genetic code and its use has accumulated...
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The beneficial role of selenium became apparent in the 1950’s, when it was shown to prevent a variety of diseases in animals, often when these animals were already exhibiting vitamin E deficiency. In humans, t...
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Selenium deficiency has long been documented to result in impaired male fertility of rats, mice and boars. The prominent feature of selenium-deficient spermatozoa is a distorted architecture of the midpiece, w...
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An overview of the evolution of human dietary standards for selenium in the United States is presented beginning with the Estimated Safe and Adequate Daily Dietary Intakes (ESADDIs) in 1980, followed by the Re...
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The biosynthesis and specific incorporation of selenocysteine into protein in bacteria requires the function of two cis and four trans elements. The cis elements are a UGA codon determining the position of seleno...
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Selenoprotein P is the major plasma selenoprotein. It is a heparin binding protein and associates with endothelial cells throughout the body. Selenoprotein P contains multiple selenocysteine residues and is gl...
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Monoselenophosphate has been identified as the activated selenium donor in Escherichia coli that is required for both the biosynthesis of selenocysteine in selenium-dependent enzymes and for the conversion of 2-t...
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The 15 kDa selenoprotein (Sep15) is one of several recently identified selenoproteins. It contains a single selenocysteine residue in the middle of a 162-amino acid open reading frame and has no detectable hom...
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The 3′-untranslated regions (UTRs) of selenoprotein mRNAs contain a stable stem-loop termed the selenocysteine insertion sequence (SECIS) element. Among the trans-acting factors that are thought to be required fo...
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Human and mammalian thioredoxin reductases are selenoproteins containing an essential catalytically active selenocysteine (Sec) residue. In contrast to the enzymes from bacteria, yeast and plants, the mammalia...
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Studies on selenoprotein expression are revealing three distinct patterns of selenium regulation. In rats, selenium deficiency can result in >90% decreases in both glutathione peroxidase-1 (GPx1) activity and ...
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A confluence of different types of evidence indicates that the essential nutrient selenium can affect cancer risk. Most epidemiological studies have shown inverse associations of selenium status and cancer ris...
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It has been recognized from the 1970s that an adequate selenium intake is necessary for the optimum function of both cellular and humoral immune processes. This chapter reviews the effects of selenium on immun...
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Recent work with selenium has demonstrated that a deficiency in this trace mineral will lead to increased viral pathogenesis. Selenium-deficient animals infected with a viral pathogen demonstrate immune dysfun...
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Most ingested forms of selenium ultimately are metabolized to low molecular weight inorganic and organic compounds that play a central role in human health either via incorporation into selenoproteins or bindi...
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Important unresolved questions raised by the contributors of this book and addressing roles of selenium in biology and human health are discussed. Resolving major scientific controversies in the field should f...
Book
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Historically, the image of selenium has changed dramatically over the last century. Initially, selenium was widely considered to be a toxic agent in mammals. In the 1930s, this element was found to be responsi...