selenium

selenium /se·le·ni·um/ (se-le´ne-um) a chemical element, at. no. 34, symbol Se; it is an essential mineral nutrient, being a constituent of the enzyme glutathione peroxidase.

---

selenium sulfide  a topical antiseborrheic and antifungal, used in the treatment of seborrheic dermatitis and dandruff of the scalp and of tinea versicolor.

---

se·le·ni·um (s-ln-m)

n. Symbol Se

A nonmetallic essential trace element used in its disulfide form as an antiseborrheic and as a radioisotope to image the pancreas and parathyroid glands. Atomic number 34.

---

selenium (s·lēˑ·nē·m),

n an essential element/mineral found in most vegetables, breads, and meats. Has been used in AIDS, asthma, car-diovascular conditions, cataracts, cervical dysplasia, multiple sclerosis, osteoarthritis, and rheumatism. No known precautions, but selenium supplementation is toxic at daily doses greater than 750 μg.

---

selenium (Se) (slē´nēum),

n a trace element used in the treatment of seborrhea and dandruff of the scalp. Selenium is toxic in large amounts.

Selenomonas

n a genus of gram-negative, anaerobic, rod-shaped bacteria found in the oral cavity.

---

selenium

a chemical element, atomic number 34, atomic weight 78.96, symbol Se. See Table 6. It is an essential mineral nutrient and a very potent poison.

---

selenium-75

a radioisotope of selenium having a half-life of 120 days and a principal gamma ray photon energy of 265 keV; used in the radiopharmaceutical selenomethionine. Symbol ⁷⁵Se.

selenium accumulator plants

see accumulator plants.

selenium converter plants

see converter plants.

selenium indicator plants

see indicator plants.

selenium-induced infection resistance

selenium deficiency in the diet may increase the patient's susceptibility to infection.

selenium nutritional deficiency

there are well-defined deficiency and poorly defined selenium responsive diseases. A nutritional deficiency of vitamin E has many of the same effects of selenium deficiency and it is often difficult to separate the two. See also enzootic muscular dystrophy, mulberry heart disease, hepatosis dietetica, iron poisoning, weaner illthrift.

selenium poisoning

can occur on pasture growing on selenium rich soil, especially if there are selenium indicator plants growing in it. Also when selenium supplementation is carried out carelessly and there is accidental access to poisonous amounts. Acute poisoning features diarrhea, dyspnea and death. Subacute poisoning is hallmarked by blind staggers (see dummy). Chronic poisoning produces a syndrome of stiff gait, loss of haircoat and separation, perhaps sloughing, of the hooves. Called also alkali disease.

Coronary separation caused by selenium poisoning. By permission from Knottenbelt DC, Pascoe RR, Diseases and Disorders of the Horse, Saunders, 2003

selenium-responsive diseases

diseases such as reproductive inefficiency and illthrift in sheep and cattle respond in some situations to dietary supplementation with selenium but the diseases are not proven to be caused by nutritional deficiency of the element.

selenium sulfide, selenium disulfide

a commonly used keratolytic in medicated shampoos employed in the treatment of skin disease in dogs and cats.

selenium weed

see neptunia amplexicaulis.