Those originally employed were based either on the fusion of the PCE to a tumour specific antibody (Antibody-Directed Prodrug Therapy, ADEPT) or on the delivery of the gene encoding the PCE using viral or non-viral vectors (Gene-Directed Enzyme Prodrug Therapy, GDEPT).
Urea is widely used in fertilizers as a source of nitrogen and is an important raw material for the chemical industry. Friedrich WÃ¶hler's discovery in 1828 that urea can be produced from inorganic starting materials was an important conceptual milestone in chemistry.
Other LOW concerns: Enhanced skin absorption, Data gaps. About UREA: Urea is a naturally occuring compound and normal metabolic constituent in biological organisms; byproduct of protein metabolism; manufactured synthetically on large scale. This ingredient may be derived from animals. From PETA's Caring Consumer: Excreted from urine and other bodily fluids. In deodorants, ammoniated dentifrices, mouthwashes, hair colorings, hand creams, lotions, shampoos, etc. Used to brown baked goods, such as pretzels. Derivatives: Imidazolidinyl Urea, Uric Acid.