(n.) A selenide containing two atoms of selenium in each molecule.
Example Sentences:
(1) We described a production of IFN-gamma and TNF-alpha by various subsets of PBL stimulated with 2-phenyl-1,2-benzisoselenazol-3(2H)-one (ebselen) or bis [2-(N-phenyl-carbamoyl)]phenyl diselenide.
(2) SR that had been extensively labeled with the diselenide spin label was resistant to ATPase inactivation by potent oxidants that arise when myoglobin reacts with hydroperoxides.
(3) The riductive scission of a diselenide (selenocystamine) produced by disulfide gives the perselenosulfide, a new compound.
(4) After reaction between ebselen and L(SH)2 the diselenide of ebselen was immediately detected.
(5) 5-Selenium-substituted derivatives (diselenides) or uracil, 2'-deoxyuridine, and 2'-deoxyuridylic acid were synthesized via the addition of methyl hypobromite to the 5,6 double bond, followed by reaction of the adducts with sodium diselenide.
(6) Furthermore, it is likely that a selenol is an intermediate in diselenide formation.
(7) This glutathione oxidase activity required the heterolytic reduction of the diselenide bond, which produced two equivalents of the selenolate derivative selenocysteamine (RSe-), via the transient formation of a selenenylsulfide intermediate (RSe-SG).
(8) The second order rate constants for the reaction of ebselen (0.29 mM-1 min-1), ebselen-glutathione selenosulfide (less than or equal to 0.01 mM-1 min-1), ebselen selenol (2.8 mM-1 min-1) and ebselen diselenide (0.32 mM-1 min-1) with hydrogen peroxide reveal that the selenol is particularly active in this respect.
(9) We tested the antiproliferative effects of Diheptyl Diselenide (DHDSe) on several different human cancer cell lines.
(10) Under these conditions, BSC was partially converted to dibenzyl diselenide (DDS) and phenylmethaneseleninic acid.
(11) No additional cytotoxicity due to the selenium atom was observed, with the exception of diselenide (-SeSe-) compounds.
(12) These observations suggest that electrostatic interactions affect the reductive cleavage of diselenide and selenenylsulfide linkages.
(13) Specificity studies reveal that variation of the N-substituent in the benzisoselenazolone system does not influence cytochrome P-450 inactivation, whereas ebselen derivatives with methylated or glucuronidated selenium moiety as well as diselenides do not convert cytochrome P-450 to P-420.
(14) On the other hand, membranes that had been extensively treated with the diselenide spin label and were then subjected to these peroxide treatments were fully active after mercaptoethanol-mediated cleavage of the thioselenides.
(15) Sodium dodecyl sulfate gel electrophoresis showed that peroxide-mediated crosslinking of ATPase observed in unmodified SR membranes did not occur in the diselenide-modified SR membranes.
(16) The determination of the relative amounts of ebselen selenol and diselenide under typical peroxidase assay conditions implies that the selenol is the predominant molecular species responsible for the glutathione--(70%)--and dithiothreitol--(96%)--dependent peroxidase activity of ebselen.
(17) The most active cytokine inducers were: 2-phenyl-1,2-benzisoselenazol-3(2H)-one (1, ebselen), bis [2-(N-phenylcarbamoyl)]phenyl diselenide (7) and bis (2-[N-(2-pyridyl)carbamoyl])phenyl diselenide (8).
(18) Protein mixed thioselenides formed by reaction of sarcoplasmic reticulum (SR) with diselenide biradical spin labels were quantified by ESR.
(19) The fast formation of the diselenide with L(SH)2 versus the slow formation of the diselenide with GSH accounts for our observation that L(SH)2 is a better cofactor than GSH in the peroxidase activity of ebselen.
(20) Finally the diselenide reacts with a peroxide and ebselen is regenerated.
Selenium
Definition:
(n.) A nonmetallic element of the sulphur group, and analogous to sulphur in its compounds. It is found in small quantities with sulphur and some sulphur ores, and obtained in the free state as a dark reddish powder or crystalline mass, or as a dark metallic-looking substance. It exhibits under the action of light a remarkable variation in electric conductivity, and is used in certain electric apparatus. Symbol Se. Atomic weight 78.9.
Example Sentences:
(1) It was tested for recovery and separation from other selenium moieties present in urine using both in vivo-labeled rat urine and human urine spiked with unlabeled TMSe.
(2) Dietary factors affect intestinal P450s markedly--iron restriction rapidly decreased intestinal P450 to beneath detectable values; selenium deficiency acted similarly but was less effective; Brussels sprouts increased intestinal AHH activity 9.8-fold, ECOD activity 3.2-fold, and P450 1.9-fold; fried meat and dietary fat significantly increased intestinal EROD activity; a vitamin A-deficient diet increased, and a vitamin A-rich diet decreased intestinal P450 activities; and excess cholesterol in the diet increased intestinal P450 activity.
(3) Mice exhibiting this suppression of immunity had levels of blood glutathione peroxidase, serum selenium, and liver DNA, RNA and protein similar to mice receiving selenium only.
(4) Excess levels of selenium (2.5 and 5 ppm) in the vitamin E-deficient diet had little or no effect on spleen size or hematocrit of rats not receiving lead, but partially prevented the splenomegaly and anemia of red cells from either non-poisoned or lead-oisoned vitamin E-deficient rats, but not as effectively as vitamin E. These results show that vitamin E status of rats is more important that selenium status in determining response to toxic levels of lead.
(5) Plasma selenium concentration and glutathione peroxidase activity in the subjects who died within 1 year of screening were 89% and 88%, respectively, of the values among survivors (p less than 0.01).
(6) Although selenium deficiency in livestock is consequently now rare in Oregon, selenium-deficient soils and attendant selenium deficiency conditions have been reported near the Kesterson Wildlife Refuge in the Northern part of the San Joaquin Valley, California, where, paradoxically, selenium toxicity in wildfowl, nesting near evaporation ponds, occurred and attracted wide attention.
(7) The synthetic "C" nucleoside, tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide), its selenium analogue selenazofurin, and the related inhibitor of inosine 5'-phosphate (IMP) dehydrogenase, mycophenolic acid, are effective inducers of the terminal differentiation of HL-60 promyelocytic leukemia cells.
(8) Thus, in this population with intermediate selenium intake, low serum selenium is not associated with an excess risk of myocardial infarction.
(9) Liver, blood, kidney and lungs were found to contain most of the selenium, here also a two-phased elimination was observed.
(10) These findings suggest that neither serum levels of selenium nor those of retinol have an appreciable effect on the risk of cancer.
(11) The incidences of esophageal tumors were statistically not significant among rats on normal, high and low selenium intake (P greater than 0.05).
(12) Alteration of guinea pig erythrocyte superoxide dismutase activity by the dietary antioxidants ascorbic acid and selenium was investigated.
(13) The more severe was the PIH the lower was the selenium level.
(14) Significantly lower selenium values were observed in blood from colorectal cancer patients than from normal individuals (0.1349 ppm vs. 0.1502 ppm.
(15) Selenium-deficient rats were used to examine the nature of the oxidant stress.
(16) Although treatment with beta-carotene tended to decrease the incidence and number of large intestinal carcinomas, beta-carotene, selenium, esculin and eugenol all decreased the incidence of kidney nephroblastomas, the differences were not statistically significant.
(17) These studies were designed to measure leukotriene B4 (LTB4) production by polymorphonuclear leukocytes (PMN) from selenium (Se)-deficient and Se-adequate goats.
(18) Copper deficiency impairs cell-mediated immunity, as does selenium deficiency when it is associated with vitamin E lack.
(19) Many forms of selenium supplement are commercialized.
(20) The possibility that a sub-clinical deficiency of the trace element selenium might exist in a sample of the British population was examined by giving a selenium supplemented for 5 weeks.