Cancer various, selenium

Sirianni SR, Huang CC. 1983. Induction of sister chromatid exchange by various selenium compounds in Chinese hamster cells in the presence and absence of S9 mixture. Cancer Lett 18 109-116. 

Various aspects of selenium have been reviewed, including its toxicology and selenium deficiency (5-7) and its protective effects against cancer (8). 

Exposure duration was not clearly identified, although fishermen were reported to consume fish at twice the rate of the reference population. East coast fishermen had higher blood levels of RGBs than the reference populations, but they also had higher levels of dioxins and furans (Svensson et al. 1995b) mercury and selenium were also higher in fishermen than in referents. Analyses of cancer incidence at various specific sites also did not show statistically significant Increased risk. 

Samples such as hair, nails, blood, urine, and various tissues are analyzed by NAA for both essential and toxic trace elements (Bhandari et al. 1987, Lai et al. 1987). The analysis can be related to determine their effect on disease outcomes. These authors have reported that the diet and environment contribute largely towards the trace elements in the human body. It is has been demonstrated in other works that the selenium concentration in human nails is an accurate monitor of the dietary intake of selenium. As a consequence, the nail monitor has been extensively used to study the protective effect of dietary selenium against cancer and heart disease in numerous prospective case-control studies. In another study by Kanabrocki et al. (1979) on human thumbnails in USA, using thermal NAA technique, the average concentration of metals studied in clinically symptom-free adult female and male subjects were found to be zinc, 184 vs. 153 ppm chromium, 6.8 vs. 4.2 selenium, 0.9 vs. 0.6 gold, 2.6 vs. 0.4 mercury, 1.9 vs. 0.4 silver 0.7 vs. 0.3 cobalt, 0.07 vs. 0.04. In another study, the fluorine concentration in bone biopsy samples was... 

Selenium availability from various foodstuffs has been reviewed [43 ], as has its role in the management of cancers [44 ]. 

Selenoproteins seem to have a number of functions, comprising various catalytic roles (glutathione peroxidases, thioredoxin reductases, and iodothyronine deiodinases), structural roles, detoxifying functions (e.g., selenoprotein P), and storage and transport activities. Many of these functions are incompletely understood, and advances in this area should help to clarify uncertainties about human requirements and the role of selenoproteins in disease, especially in multifactorial conditions such as cancers. Several controlled intervention trials involving selenium are under way, and these should provide evidence to underpin public health programs in the near future. 

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