Discovery and development of direct Xa inhibitors Xa was identified as a promising target for the development of new anticoagulants in the early 1980s. In 1987 the first factor Xa inhibitor, the naturally occurring compound antistasin, was isolated from the salivary glands of the Mexican leech "Haementeria officinalis". Antistasin is a polypeptide and a potent Xa inhibitor. In 1990 another naturally occurring Xa inhibitor was isolated, tick anticoagulant peptide (TAP) from extracts of the tick "Ornithodoros moubata". TAP and antistasin were used to estimate factor Xa as a drug target. Blood coagulation is a complex process by which the blood forms clots. It is an essential part
Krause's glands Krause's glands Krause's glands are small, mucous accessory lacrimal glands that are found underneath the eyelid where the upper and lower conjuctivae meet. Their ducts unite into a rather long sinus which open into the fornix conjunctiva. There are approximately forty Krause glands in the region of the upper eyelid, and around 6 to 8 in the region of the lower lid. The function of these glands are to produce tears which are secreted onto the surface of the conjuctiva. There are rare instances of tumors associated with Krause's glands. They usually occur as retention cysts in cicatricial conditions of