Both drugs had been previously recommended for approval 14-0 by members of FDA's Anti-Infective Drugs Advisory Committee. The significance of two new antibiotics in four weeks? We've recently been averaging one antibiotic every three years.
Skin color is due primarily to the presence of a pigment called melanin, which is controlled by at least 6 genes. Both light and dark complexioned people have melanin. However, two forms are produced--pheomelanin, which is red to yellow in color, and eumelanin, which is dark brown to black.
Pigments that contribute to skin color are called carotene, a yellowish hemoglobin, in blood vessels (pink-red), and melanin (black, brown, red). Darker skins are dominated by melanin, which is produced from the amino acid tyrosine, by pigment cells (melanocytes) in the skin.igments that contribute to skin color are called carotene, a yellowish hemoglobin, in blood vessels (pink-red), and melanin (black, brown, red). Darker skins are dominated by melanin, which is produced from the amino acid tyrosine, by pigment cells (melanocytes) in the skin.