Selenium

About: Selenium is a research topic. Over the lifetime, 21192 publications have been published within this topic receiving 429715 citations. The topic is also known as: Se & selen.

A prospective cohort study on selenium status and the risk of lung cancer.

Abstract: Selenium has been suggested to be anticarcinogenic and to play a role in the cellular defense against oxidative stress. The association between toenail selenium (a marker of long-term selenium status) and lung cancer was investigated in a cohort study of diet and cancer that started in 1986 among 120,852 Dutch men and women aged 55–69 years. After 3.3 years of follow-up, 550 incident cases of lung carcinoma were detected. Toenail selenium data were available for 370 lung cancer cases and 2459 members of a randomly selected subcohort. The rate ratio of lung cancer for subjects in the highest compared to the lowest quintile of toenail selenium, after controlling for age, gender, smoking, and education, was 0.50 (95% confidence interval, 0.30–0.81), with a significant inverse trend across quintiles ( P = 0.006). The protective effect of selenium was concentrated in subjects with a relatively low dietary intake of β-carotene or vitamin C. The rate ratio in the highest compared to the lowest quintile of selenium was 0.45 in the low β-carotene group (95% confidence interval, 0.22–0.92; trend P = 0.028) and 0.36 in the low vitamin C group (95% confidence interval, 0.17–0.75; trend P < 0.001). The results of this study support an inverse association between selenium status and lung cancer and suggest a modification of the effect of selenium by the antioxidants β-carotene and vitamin C.

Studies in Selenious Acid Reduction and CdSe Film Deposition

Abstract: The reaction sequence for the reduction of in at various surfaces and the formation of selenide films in this medium with and without metal ions present have been investigated by rotating disk and ring‐disk electrode techniques. The system is complicated by competitive paths leading to selenium formation from Se(−2)‐Se(+4) chemical reactions and the result is sensitive both to the nature of the substrate with the possibility of metal selenide formation and to the concentration of solution species. The implications for cathodic deposition of semiconductors like , from voltammetric and photospectral data, are discussed.

Speciation of selenoamino acids and organoselenium compounds in selenium-enriched yeast using high-performance liquid chromatography-inductively coupled plasma mass spectrometry

Abstract: As part of an ongoing study to identify selenium compounds with cancer chemopreventive activity, selenium-enriched yeast was analyzed by HPLC–ICP-MS. More than twenty selenium-containing species were found in hot water and enzymatic hydrolysis extracts of the yeast. Trifluoroacetic acid was used as an ion-pairing agent in a water–methanol mobile phase with reversed-phase chromatography on an octylsilane stationary phase. The presence of selenocystine, selenomethionine and methylselenocysteine was confirmed by comparative retention of standards. The column efficiency was 8500 theoretical plates and the mobile phase was compatible with standard ICP-MS operating conditions.

Binding of simultaneously administered inorganic selenium and mercury to a rat plasma protein.

Abstract: SummarySimultaneous administration of 5 μmoles of HgCl2 and of SeO32-/kg along with traces of 203HgCl2 and 75SeO32- to a rat radically alters plasma protein binding of 75Se and 203Hg from that found when each element is given alone. After simultaneous administration both elements are present in the plasma in much greater quantities due to their binding to a single plasma protein. When the doses of the elements are varied the molar ratio of selenium to mercury in the protein remains close to 1. Dialysis data suggest that selenium is attached to a sulfhydryl group of the protein and that mercury is attached to selenium. This protein may play a role in preventing acute inorganic mercury toxicity by preventing a large part of the mercury dose from reaching target tissues.