Willow active extract of the bark, called salicin, was isolated to its crystalline form in 1828 by Henri Leroux, a French pharmacist, and Raffaele Piria, an Italian chemist, who then succeeded in separating out the compound in its pure state. In 1897, Felix Hoffmann created a synthetically altered version of salicin (in his case derived from the "Spiraea" plant), which caused less digestive upset than pure salicylic acid. The new drug, formally acetylsalicylic acid, was named Aspirin by Hoffmann's employer Bayer AG. This gave rise to the hugely important class of drugs known as nonsteroidal anti-inflammatory drugs (NSAIDs). Some of humans'
Lymphatic endothelium vessels considered less important. Later it was discovered that VEGF-R3 and VEGF-C/VEGF-D were the key growth factors controlling lymphatic endothelial proliferation. Markers of lymphatic endolthelium were not discovered until relatively recently. These being LYVE-1 (Jackson et al.,1999) and podoplanin (Kerjaschki,1999). Endothelium Lymphatic endothelium The lymphatic endothelium is a specialised form of epithelium, distinct from but similar to vascular endothelium. A lymph capillary endothelial cell is distinct from other endothelial cells in that collagen fibers are directly attached to its plasma membrane. Although lymphatics were first described by Hippocrates in 400BC and rediscovered as "milky veins in the gut of a