Tympanic membrane retraction caused by erosion of the ossicles (hearing bones). Discharge from the ear often indicates that the retraction pocket has developed into a cholesteatoma. Three factors must occur for the tympanic membrane to become retracted: When gas pressure within the middle ear is less than atmospheric pressure, the eardrum can become sucked into the middle ear space. This is caused by inadequate opening of the Eustachian tube and absorption of air from the middle ear space. People with a patulous Eustachian tube may also cause negative middle ear pressure by repeatedly sniffing to try to keep their Eustachian tube closed. The
Plasma membrane Ca2+ ATPase to involve the lymph nodes, and are more common among young women, which could help explain their worse prognosis compared with postmenopausal women. PMCAs were first discovered in the 1960s in the membranes of red blood cells. The presence of an ATPase was discovered in the membranes in 1961, and then in 1966 it was discovered that these ATPases pump Ca out of the cytosol. PMCA was first purified from red blood cell membranes in 1979. Plasma membrane Ca2+ ATPase The plasma membrane Ca ATPase (PMCA) is a transport protein in the plasma membrane of cells and functions to remove