Selenium incorporation into the polynucleotide structures of tRNAs has been documented in several microorganisms. In the present study, selenium-containing species were isolated from bulk tRNA preparations from 75Se-labeled mouse leukemia cells. The major 75Se-labeled species was similar in size and exhibited the same sensitivity to ribonuclease as did Escherichia coli tRNAs. The chromatographi...

We have used a cloned cDNA for the major human selenoprotein, glutathione peroxidase (GPx), to assess the mode of regulation of human GPx gene (GPX-1) expression by selenium. When the HL-60 human myeloid cell line is grown in a selenium-deficient medium, GPx enzymatic activity decreases 30-fold compared with selenium-replete cells. Upon return to a medium containing selenium in the form of sele...

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 ...

BACKGROUND Selenium is one of the trace minerals whose deficiency is known to lead to complications of female reproduction. The identified gaps in researches regarding selenium and pregnancy include optimizing the dosage of selenium supplementation, timing of supplementation, finding the best form and type of selenium, and selenium administration combined with other antioxidants. Hence, this st...

Fischer 344 rats fed on a diet that is deficient in selenium are more resistant to the hepatocarcinogen aflatoxin B1 (AFB1) than those fed on a selenium-sufficient diet. Hepatic cytosol from either selenium-deficient Fischer 344 rats or Hooded Lister rats possesses a marked increase in both reductase activity toward AFB1-dialdehyde and glutathione S-transferase (GST) activity toward AFB(1)-8,9-...

Prevention trials showed that selenium reduced prostate cancer incidence by 50%, establishing selenium as a promising chemopreventive agent for prostate cancer. Selenium inhibited human prostate cancer cell growth, blocked cell cycle progression at multiple transition points, and induced apoptotic cell death. Previous studies showed a novel mechanism of selenium anticancer action in which selen...

A method to estimate the content of selenium in organics was introduced based on reversed phase-high performance liquid chromatography (RP-HPLC).The maximum absorption peak of piazselenol was at 330 nm and the optimized temperature and pH value were 40 degrees C and 2.8, respectively. The minimum detection concentration of selenium(IV) was 0.06 microg/mL and the measurable range was 0.12-12.0 m...

Two concepts are often currently applied to selenium in adult men in the United States: • Intake is generally enough to maximize blood glutathione peroxidase activities. • In such men, selenium supplementation does not reduce risk of prostate cancer. In contrast to these concepts, 30 healthy middle-aged men were studied to test the following hypothesis: 6-week supplementation of 200 μg of selen...

Selenium deficiency in rats for a period of up to 6 weeks inhibited both the production of 3,3',5-tri-iodothyronine (T3) from thyroxine (T4) (5'-deiodination) and also the catabolism of T3 to 3,3'-di-iodothyronine (5-deiodination) in liver homogenates. The hepatic stores of T3 were decreased by only 8% in selenium deficiency, despite the T3 production rate from T4 being only 7% of the rate foun...

BACKGROUND Evidence that selenium affects the risk of type-2 diabetes is conflicting, with observational studies and a few randomized trials showing both lower and higher risk linked to the level of selenium intake and status. We investigated the effect of selenium supplementation on the risk of type-2 diabetes in a population of relatively low selenium status as part of the UK PRECISE (PREvent...