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.
What is it used for? 1  Urea is used to treat chronic dry skin conditions, such as eczema. 2  It is also used to treat skin conditions that cause dry, thickened, scaly, flaky and cracked skin (ichthyosis, xeroderma) and thickening of the outermost layer of the skin (hyperkeratosis).