Keshan Disease Areas Research Articles

The changes of myocardial respiratory function in rats kept on Keshan disease area grain

The changes of myocardial respiratory function in rats kept on Keshan disease area grain

Effect of the grain from Keshan disease areas on myocardial ATP contents inexperimental rats

Effect of the grain from Keshan disease areas on myocardial ATP contents inexperimental rats

The changes in myocardial structural proteins of rats fed on Keshan disease area grain and its significance

The changes in myocardial structural proteins of rats fed on Keshan disease area grain and its significance

Selenium interactions with carcinogens

Although selenium was once considered to be a toxic, undesirable and carcinogenic element, it is now recognized as an essential element with anticarcinogenic properties. Epidemiological studies in the United States have shown an inverse relationship between selenium intake and certain forms of cancer in humans, but other factors must be considered since cancer is not higher in people living in selenium-deficient areas of the world (Finland, New Zealand, and Keshan disease area, China). Under most dietary conditions, selenium has been shown to reduce the spontaneous mammary tumor incidence in an inbred strain of mice. In general, selenium will counteract to various degrees, the chemical carcinogens used to produce lesions of the skin [coaltar, 3-methylcholanthrene, α-pyrene, and 7,12 dimethylbenz(a) anthracene (DMBA)], liver (3-methyl-4-dimethyl-aminoazobenzene, aflatoxin B 1, and 2-acetylaminofluorene), mammary gland (DMBA and N-methyl-N-nitrosurea), and intestinal tract [1,2-dimethylhydrazine,bis(2-oxopropyl) nitrosamine, and azoxymethane]. Dietary factors, such as fat, will modify the protective effects of selenium. High dietary unsaturated fats, for example, markedly increase the mammary tumors in rats treated with DMBA, and selenium will reduce the tumor incidence but not to the level of rats fed a low fat diet. Other factors known to affect the anticarcinogenic effects of selenium include synthetic antioxidants, vitamin E, vitamin A and ascorbic acid. The mechanisms of selenium counteraction of carcinogens remain unknown.

Endemic selenium intoxication of humans in China

AbstractAn endemic disease was discovered in 1961 in parts of the population of Enshi County, Hubei Province of the People's Republic of China. During the years of the highest prevalence, from 1961 to 1964, the morbidity was almost 50% in the 248 inhabitants of the five most heavily affected villages; its cause was determined to be selenium intoxication. The most common sign of the poisoning was loss of hair and nails. In areas of high incidence, lesions of the skin, nervous system, and possibly teeth may have been involved. A case is reported of a middle-aged, female hemiplegic, whose illness and death apparently were related to selenosis. Daily dietary intakes of selenium, estimated after the peak prevalence had subsided, averaged 4.99 (range 3.20 to 6.69) mg and hair and blood selenium levels averaged 32.2 and 3.2 μg/ml, respectively. Up to l000× differences occurred when selenium contents of vegetables, cereals, scalp hair, blood, and urine from the selenosis areas were compared with those from Keshan disease (selenium deficiency) areas. The ultimate environmental source of selenium was a stony coal of very high selenium content (average more than 300 μg/g; one sample exceeded 80,000 μg/g). Selenium from the coal entered the soil by weathering and was available for uptake by crops because of the traditional use of lime as fertilizer in that region. This particular outbreak of human selenosis was due to a drought that caused failure of the rice crop, forcing the villagers to eat more high-selenium vegetables and maize and fewer protein foods.