Diseases Keshan

Keshan disease Keshan Disease Keshan disease Kessco... 

Selenium is an essential element and is beneficial at low concentrations, serving as an antioxidant. Lack of selenium affects thyroid function, and selenium deficiencies have been linked to Keshan Disease (34). Selenium at high levels, however, is toxic. Hydrogen selenide (which is used in semiconductor manufacturing) is extremely toxic, affecting the mucous membranes and respiratory system. However, the toxicity of most organ oselenium compounds used as donor compounds for organic semiconductors is not weU studied. 

Pure selenium deficiency, without concurrent vitamin E deficiency, is not generally seen except in animals on experimental diets (113). In China, selenium deficiency in humans has been associated with Keshan disease, a cardiomyopathy seen in children and in women of child-bearing ages, and Kashin-Beck disease, an endemic osteoarthritis in adolescents (113). 

Selenium deficiency has been identified iu humans iu a broad area of China, stretching from the northeast to the southwest. Two syndromes are evident Keshan disease, an endemic cardiomyopathy which affects children, and Kashin-Beck disease, an edemic osteoarthropathy (big-joiat), also mainly involving children, which occurs iu eastern Siberia and parts of China. As a result of these observations, a protective effect for selenium has been proposed, and various selenium-containing preparations have been appHed to preserve animal and human health. 

Keshan disease (selenium deficiency) Sickle cell anaemia... 

At the end of the 1960s the biogeochemical studies of selenium were initiated in China to determine the causes of two endemic human diseases, Keshan disease and Kachin-Beck disease. The former is an endemic cardiomyopathy, and the latter is an endemic osteoarthrosis (Tan et al., 1994). 

Figure 3. Distribution map of annual average incidences of Keshan disease (acute and subacute) in China (Tan et al., 1994).

Keshan disease, selenium and, 22 101 Kessener brush aerators, 26 162 Kestner-Johnson dissolver, 22 672 Kestner process, 2 723 Ketals, aroma chemicals, 3 253 Ketazine processes, 13 576, 579—581 disadvantages of, 13 581 Ketene(s), 10 484... 

Seleninm in this form is present in three enzymes glutathione peroxidase, iodothyronine deiodinase and thio-redoxin rednctase. Deficiency of selenium therefore decreases the activity of these three enzymes and resnlts, at least in experimental animals, in liver necrosis and mns-cnlar dystrophy. In hnmans, it is known to be a canse of a particnlar form of cardiomyopathy known as Keshan disease which affects children and women. This cardiomyopathy was first described in China in 1979. It is also considered that a deficiency of selenium is a risk factor for cancer. 

In 1957, Schwartz and associates showed that the toxic element selenium was also a nutritional factor essential for prevention of the death of liver cells in rats.527 Liver necrosis would be prevented by as little as 0.1 ppm of selenium in the diet. Similar amounts of selenium were shown to prevent a muscular dystrophy called "white muscle disease" in cattle and sheep grazing on selenium-deficient soil. Sodium selenite and other inorganic selenium compounds were more effective than organic compounds in which Se had replaced sulfur. Keshan disease, an often fatal heart condition that is prevalent among childen in Se-deficient regions of China, can be prevented by supplementation of the diet with NaSe03.528 Even the little crustacean "water flea" Daphnia needs 0.1 part per billion of Se in its water.529... 

Keratan sulfate 175-177,176s disulfide bridges 115 AT-linked 185 terminal units 181 Keratin 70, 369 Keratinocytes 439 Keshan disease 822 Kethoxal 253... 

Keshan disease -from selenium deficiency [MINERAL NUTRIENTS] (Vol 16)... 

In addition to Keshan disease, a dilative cardiomyopathy first described in the Keshan Province of China, Se deficiency has been associated with an increase in various malignant diseases. Thus, well over 50 studies have demonstrated significant reductions in experimental cancer in laboratory animals supplemented with Se. Moreover, reports from Finland and the United States support the hypothesis that Se deficiency results in decreased cellular GPx activity, increases oxidative stress, and increases the incidence of cancer, particularly carcinoma of the breast, prostate, and colon (K13). 

Se has a greatly uneven distribution in the world. For example, there are Se-deficient places with the Keshan disease due to scant Se intake in Keshan (China) while by contrast, in other places of China, the levels of Se concentration are toxic to humans and animals. The Se accumulation and distribution in plants hence varies among species, and as a function of chemical forms and concentrations of Se supplied. In general, with an elemental abundance of 0.08 J,g g in the Earth s crust and 13 4g g in the Earth s interior, the existence and speciation of Se in nature is so dispersive that it commonly does not reach a threshold abundance warranting industrial... 

In the Se-deficient areas of China, Finland, and New Zealand, the Keshan disease occurs because of a low Se intake from local food. To correct soil Se deficiency in Finland, the government initiated a national program to amend agricultural soils with Se to elevate the Se content in agricultural products. As a result, the daily dietary Se intake of residents in Finland increased from approximately 30 ag (a low value as compared to the recommended US National Research Council value of 55 J,g) to 80 4g. Therefore, seleniferous soils considered as potentially Se-contaminated sites... 

Selenium has been recognized as an essential trace element in the diets of man and animals for many years (1) Another strong indication of its essentiality is the fact that it is an essential component of the enzyme glutathione peroxidase (2) Recently, scientists from the People s Republic of China demonstrated that Keshan disease (a cardiomyopathy in children) was correlated with low dietary selenium Intakes ( ) and could largely be prevented with supplementation Similarly, poor selenium nutrition in patients receiving total parenteral nutrition has been linked to muscular discomfort (4) and cardiomyopathy ( ) ... 

Keshan Disease Research Group of the Chinese Academy of Medical Sciences Chin Med J 1979, 92, 471-482 ... 

In contrast, selenium deficiency has been implicated in several human diseases, most notably Keshan disease (KD) and Kashin-Beck disease (KBD). KD is an endemic selenium-responsive cardiomyopathy that mainly affects children and women of child-bearing age and is named after... 

Johnson C. C., Ge X., Green K. A., andEiuX. (2000) Selenium distribution in the local environment of selected villages of the Keshan Disease belt, Zhangjiakou District, Hebei Province, People s Republic of China. Appl. Geochem. 15, 385-401. 

High prevalence of enteroviral genomic sequences in myocardium from cases of endemic cardiomyopathy (Keshan disease) in China. Heart 83, 696-701. 

RNA genome codes for four proteins. Three of these proteins are virus capsule proteins (they coat the RNA), and one of these proteins is a viral protease. The virus can cause temporary fever and sore throats in children however, about 5% of infections in adults and children result in damage to the heart, It is thought that Keshan disease In China, which is associated with selenium-deficient populations, is due to some influence of the selenium deficiency on the activation of coxsackievirus Studies with nrtice have revealed an interesting phenomenon. One particular strain of coxsackievirus can infect mice, but does not result in much hann to the mice. However, when the mice arc raised on an Sc-deficient diet, the virus acquires mutations in its genome and produces damage to the mouse s heart (Beck t ai., 1995). 

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