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
Ectopic salivary gland tissue the salivary glands, including cancer, may also occur within an accessory salivary gland tissue. "Salivary gland heterotopia" is where salivary gland acini cells are present in an abnormal location without any duct system. The most common location is the cervical lymph nodes. Other reported sites of heterotopic salivary gland tissue are the middle ear, parathyroid glands, thyroid gland, pituitary gland, cerebellar pontine angle, soft tissue medial to sternocleidomastoid, stomach, rectum and vulva. Salivary gland neoplasm occurrence within heterotopic salivary gland tissue is rare. Ectopic salivary gland tissue Ectopic salivary gland tissue which is located in sites other than the normal