Manganese is also used in portland cement mixtures. Manganese is an important element for human health, essential for development, metabolism, and the antioxidant system. Nevertheless, excessive exposure or intake may lead to a condition known as manganism, a neurodegenerative disorder that causes dopaminergic neuronal death and symptoms similar to Parkinson's disease. The classes of enzymes that have manganese cofactors is large and includes oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases, lectins, and integrins. The reverse transcriptases of many retroviruses (though not lentiviruses such as HIV) contain manganese. The best-known manganese-containing polypeptides may be arginase, the diphtheria toxin, and Mn-containing superoxide dismutase (Mn-SOD).
Manganese, Minnesota crack through the concrete sidewalks. In the 1990s, a majority of the land was purchased. It is now privately owned and has a "no trespassing" sign posted on the gate of the southeastern part of the city. Presently, the area is consumed entirely by the growth of natural vegetation. Although the grid pattern of roads remains, the roads have either disintegrated or have been completely overtaken by grass, trees, and shrubs. The sheer height of the trees expose what has become of land once occupied by numerous buildings. Manganese is a classic example of a "ghost town." Manganese, Minnesota Manganese