Selenium
An essential mineral that is a component of a key antioxidant enzyme, glutathione reductase, in tissue respiration. Deficiency of selenium causes Keshan disease, a fatal form of cardiomyopathy (disease of the heart muscle) first observed in Keshan province in China and since found elsewhere. According to the National Academy of Sciences, the Recommended Dietary Allowances of selenium are 70 milligrams per day for men and 55 milligrams per day for women. Food sources of selenium include seafoods, some meats such as kidney and liver, and some grains and seeds. Too much selenium may cause reversible changes in the hair (balding) and nails, garlic odor to the breath, intestinal distress, weakness and slower mentation (slowed mental functioning).
* * *
A metallic element chemically similar to sulfur, atomic no. 34, atomic wt. 78.96; an essential trace element toxic in large quantities; required for glutathione peroxidase and a few other enzymes; 75Se (half-life equal to 119.78 days) is used in scintography of the pancreas and parathyroid glands. [G. selene, moon]
- s. sulfide a mixture of crystalline s. monosulfide and solid solutions of s. and sulfur in an amorphous form, containing 52–55.5% Se; used in the treatment of seborrhea of the scalp or dandruff; it is applied to the scalp as a suspension.

* * *

se·le·ni·um sə-'lē-nē-əm n a nonmetallic element that resembles sulfur and tellurium chemically, causes poisoning in range animals when ingested by eating some plants growing in soils in which it occurs in quantity, and occurs in allotropic forms of which a gray stable form varies in electrical conductivity with the intensity of its illumination and is used in electronic devices symbol Se see ELEMENT (table)

* * *

n.
a trace element that is an essential component of the enzyme glutathione peroxidase, which catalyses the oxidation of glutathione by hydrogen peroxide. It thus has important antioxidant properties. Dietary deficiency of selenium results in cardiomyopathy. Symbol: Se.

* * *

se·le·ni·um (Se) (sə-leґne-əm) [Gr. selēnē moon] a nonmetallic element resembling sulfur; atomic number, 34; atomic weight, 78.96. It is an essential mineral, being a constituent of the enzyme glutathione peroxidase, and believed to be closely associated with vitamin E in its functions. Selenium occurs in toxic levels in certain plants growing in soil with high concentrations of it, causing selenium poisoning (q.v.) in grazing animals. Dietary deficiency, occurring where the soil has a low sodium content, results in cardiomyopathy (see Keshan disease, under disease).

Medical dictionary. 2011.

Look at other dictionaries:

  • Selenium — (pronEng|səˈliniəm) is a chemical element with the atomic number 34, represented by the chemical symbol Se, an atomic mass of 78.96. It is a nonmetal, chemically related to sulfur and tellurium, and rarely occurs in its elemental state in nature …   Wikipedia

  • Sélenium — Sélénium Sélénium Arsenic …   Wikipédia en Français

  • SÉLÉNIUM — Le sélénium a été découvert en 1817 par Jöns Jacob Berzelius dans les boues des chambres de plomb utilisées pour la préparation de l’acide sulfurique. C’est un élément rare, présent très souvent à l’état de traces dans les sulfures naturels où il …   Encyclopédie Universelle

  • Selenium — Entwickler ThoughtWorks Aktuelle Version 2.11.0 (28. Oktober 2011) Betriebssystem Microsoft Windows, Linux, Mac OS X, Solaris, FreeBSD und andere Unix Varianten (basiert auf …   Deutsch Wikipedia

  • selenium — SELÉNIUM s.n. v. seleniu. Trimis de LauraGellner, 13.09.2007. Sursa: DEX 98  SELÉNIUM s.n. v. seleniu. Trimis de LauraGellner, 13.09.2007. Sursa: DN …   Dicționar Român

  • Selenium — Se*le ni*um, n. [NL., from Gr. selh nh the moon. So called because of its chemical analogy to tellurium (from L. tellus the earth), being, as it were, a companion to it.] (Chem.) A nonmetallic element of the sulphur group of atomic number 34,… …   The Collaborative International Dictionary of English

  • Selenĭum — (Chem.), so v.w. Selen …   Pierer's Universal-Lexikon

  • selenium — Symbol: Se Atomic number: 34 Atomic weight: 78.96 Metalloid element, belongs to group 16 of the periodic table. Multiple allotropic forms exist. Chemically resembles sulphur. Discovered in 1817 by Jons J. Berzelius …   Elements of periodic system

  • selenium — (n.) element name, Modern Latin, from Gk. selene moon (see SELENE (Cf. Selene)). Named by Berzelius (1818), on analogy of TELLURIUM (Cf. tellurium), with which it had been at first confused, and which was named for the earth. Despite the ium… …   Etymology dictionary

  • selenium — [sə lē′nē əm] n. [ModL: so named (1818) by BERZELIUS Baron Jöns Jakob < Gr selēnē, the moon (see SELENE) + IUM, by analogy with TELLURIUM, with which it was assoc. in the ore] a nonmetallic chemical element with several allotropic forms, used… …   English World dictionary

  • Sélénium — Pour les articles homonymes, voir Selenium. Sélénium Arsenic ← Sélénium → …   Wikipédia en Français

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”