Scientific opinion on the relationship between selenium and the risk of cancer has undergone radical change over the years, with selenium first viewed as a possible carcinogen in the 1940s then as a possible cancer preventive agent in the 1960s-2000s. More recently, randomized controlled trials have found no effect on cancer risk but suggest possible low-dose dermatologic and endocrine toxicity...

The present studies demonstrate that the ability of supplemental selenite to alter the in vitro growth of canine mammary tumor cell line 13 was dependent on the quantity and duration of selenium exposure and on the culture density. Exposure to 3.2 microM selenite did not significantly alter growth but led to an increase in intracellular glutathione (GSH). The severity of growth inhibition betwe...

INTRODUCTION Iron cardiomyopathy is a lethal complication of transfusion therapy in thalassemia major. Nutritional supplements decreasing cardiac iron uptake or toxicity would have clinical significance. Murine studies suggest taurine may prevent oxidative damage and inhibit Ca2+-channel-mediated iron transport. We hypothesized that taurine supplementation would decrease cardiac iron-overloaded...

The essential nature of selenium as well as its toxicity depend on the concentration and the chemical forms in which this element is present in environmental and biological samples. Dissolved inorganic selenium can be found in natural waters and soils as selenides, selenite and selenate. Organoselenium compounds that may be present in air, soils and plants are volatile methylselenides, trimethy...

Selenium (Se) is an element that has been of environmental concern in aquatic systems that drain arid regions heavily used for agricultural purposes. As hypersaline conditions are associated with these ecosystems, this study examined the effect of hypersaline water on the uptake, biotransformation, and toxicity of seleno-L-methionine (SeMe) in juvenile rainbow trout. Fish were acclimated for 5 ...

During the selenium assimilation pathway, inorganic selenate and selenite are reduced to form selenocysteine (Sec). Tolerance to selenium in plants has long been attributable to minimizing the replacement of cysteine with selenocysteine, which can result in nonspecific selenoproteins that are potentially misfolded. Despite this widely accepted assumption, there is no evidence in higher plants d...

24 25 26 UN CO RR EC TE D PR Abstract. Selenium (Se) and arsenic are next-door neighbors on the periodic table and have similar chemical properties as metalloids. Arsenic antagonizes selenium toxicity in a number of organisms. Inorganic arsenic in drinking water is a human carcinogen while selenium compounds are anticarcinogenic in animals and humans. Our previous work showed that arsenite enha...

Selenium is a very effective cancer-preventive agent, suppressing tumor promotion and early stages of tumor progression. However, the mechanisms by which selenium exerts these cancer-preventive actions are not known. Protein kinase C (PKC) is a receptor for certain tumor promoters and also plays a crucial role in events related to tumor progression. Therefore, it is not only a potential target ...

Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 microg/L from 24-Road, 0.9 microg/L from Horsethief, 5.5 microg/L from Adobe Creek, and 10.7 microg/L from the North Pond. Selenium in dietary items avera...

We coupled intensive population monitoring with collection of blood samples from 383 nesting Pacific common eiders (Somateria mollisima v-nigrum) at two locations in Alaska (USA) from 2002 to 2004. We investigated annual, geographic, and within-season variation in blood concentrations of lead and selenium; compared exposure patterns with sympatrically nesting spectacled eiders (Somateria fische...