Toenail selenium and risk of type 2 diabetes: the ORDET cohort study.

Epidemiologic studies, particularly randomized controlled trials, have shown a direct relation between dietary and environmental exposure to the metalloid selenium and risk of type 2 diabetes. We investigated the association between baseline toenail selenium levels and diabetes occurrence in a case-control study nested in ORDET, a population-based female cohort in Northern Italy. After a median follow-up of 16 years, we identified 226 cases of type 2 diabetes cases and 395 age-matched control women with available toenail samples at baseline.

A case-control study of the risk of cutaneous melanoma associated with three selenium exposure indicators.

Aims And Background: A direct association between exposure to the metalloid selenium and risk of cutaneous melanoma has been suggested by some observational and experimental cohort studies, whereas other studies have yielded inconsistent results. Since some of the inconsistencies may be due to exposure misclassification arising from the use of exposure indicators that do not adequately reflect body tissue selenium content or the levels of the biologically relevant species of this metalloid, we examined this issue using multiple indicators of exposure.

Methods: We analyzed the relation of selenium exposure with risk of cutaneous melanoma using two different biomarkers, plasma and toenail selenium concentration, and estimated dietary selenium intake in a population-based case-control series (54 cases, 56 controls) from an Italian community.

Long-term selenium supplementation of humans: selenium status and relationships between selenium concentrations in skeletal muscle and indicator materials.

Supplementation with elevated doses of l-selenomethionine (SeM) or selenium-enriched yeast that contains SeM as the main selenium species is frequently used as a protective or therapeutic measure. Information on the effects of long-term selenium supplementation on the body selenium status is, however, rather scarce. We therefore investigated fifteen male test persons who had taken selenium yeast and/or SeM supplements in medium doses of 62.

Effects of long-term selenium yeast supplementation on selenium status studied in the rat.

To investigate the selenium status during long-term dietary supply of selenium yeast, 30-day-old male rats were fed for 379 days a methionine-adequate low-selenium diet supplemented with 0.2mgSe/kg (selenium-adequate diet) or 1.5mgSe/kg (high-selenium diet) in the form of selenium yeast that contained 60% of the element as l-selenomethionine.

The brain selenoproteome: priorities in the hierarchy and different levels of selenium homeostasis in the brain of selenium-deficient rats.

The application of radionuclides for the localization of essential trace elements in vivo and the characterization of their binding proteins is a story of intermittently made improvements of the techniques used for their detection. In this study we present the use of neutron activation analysis and different autoradiographic imaging methods including real-time digital autoradiography to reveal new insights in the hierarchy of selenium homeostasis. Selenoproteins containing the essential trace element selenium play important roles in the CNS.

Effects of selenium diet on expression of selenoproteins in the lung of the rat.

In the present article the radiotracer techniques have been combined with biochemical separation procedures to investigate the effects of changes in the selenium status on the expression of the selenium-containing proteins in the lung and their subcellular fractions. Subcellular separation of the lung has been achieved by differential ultracentrifugation. The selenium-containing proteins in these compartments have been investigated by labeling of rats in vivo with (75)Se, gel electrophoretic separation of the proteins, and autoradiographic detection of the tracer.

Environmental exposure to trace elements and risk of cutaneous melanoma.

Purpose: Our aim was to examine the risk of melanoma in association with exposure to trace elements of toxicological and nutritional interest.

Methods: We analyzed the concentrations of cadmium, lead, chromium, selenium, copper and zinc in toenails of 58 patients with newly diagnosed cutaneous melanoma as well as in 58 age- and sex-matched control subjects, randomly selected from the population of Modena province in northern Italy.

Results: Melanoma risk was substantially unrelated to toenail levels of cadmium, chromium, lead and selenium.

Physical and chemical limitations to preparation of beta radioactive stents by direct neutron activation.

Pure beta emitters are the sources of choice for intracoronary irradiations in restenosis prevention. In this work we reconsidered preparation of low activity 32P sources by ion-implantation of stable 31P into highly biocompatible pure titanium stents, followed by neutron activation. Gamma-spectrometrical analysis has shown that during activations with high thermal neutrons flux production of gamma-active long-lived contaminants is much beyond the dosimetrically acceptable limit, mainly due to the competing (n,p) reactions induced by the fast neutrons on isotopes of the bulk stent material, and to a lesser extent due to (n,gamma) reactions on chemical impurities.

Environmental exposure to trace elements and risk of amyotrophic lateral sclerosis: a population-based case-control study.

We analyzed the association between the environmental exposure to trace elements and the risk of sporadic amyotrophic lateral sclerosis (ALS) in a population-based case-control study in the Emilia-Romagna region in northern Italy. We evaluated exposure to selected trace elements by measuring toenail concentrations of the same by means of inductively coupled plasma optical spectrometry and instrumental neutron activation analysis. The final number enrolled in the study was 22 patients and 40 controls.

Adenosine triphosphate-induced electron transfer in 2-hydroxyglutaryl-CoA dehydratase from Acidaminococcus fermentans.

2-hydroxyglutaryl-CoA dehydratase from Acidaminococcus fermentans catalyzes the chemical difficult elimination of water from (R)-2-hydroxyglutaryl-CoA to glutaconyl-CoA. The enzyme consists of two oxygen-sensitive protein components, the homodimeric activator (A) with one [4Fe-4S]1+/2+ cluster and the heterodimeric dehydratase (D) with one nonreducible [4Fe-4S]2+ cluster and reduced riboflavin 5'-monophosphate (FMNH2). For activation, ATP, Mg2+, and a reduced flavodoxin (16 kDa) purified from A.