Tympanic membrane retraction the nose with laser or balloon dilatation is being evaluated as a potential treatment for tympanic membrane retraction. Excision of the retracted segment of an eardrum, with or without placement of a tympanostomy tube has been advocated. Healing of the area can result in a more normal eardrum. Laser therapy has been used to shrink and stiffen retraction pockets. Tympanoplasty is the surgical technique of removal of the retracted area from the middle ear and reconstruction of the tympanic membrane. Some surgeons use cartilage (taken from the outer ear) to stiffen the eardrum with the aim of preventing further retraction.
Biological membrane fatty acid composition in accordance with differing temperatures. In animal cells, membrane fluidity is modulated by the inclusion of the sterol cholesterol. This molecule is present in especially large amounts in the plasma membrane, where it constitutes approximately 20% of the lipids in the membrane by weight. Because cholesterol molecules are short and rigid, they fill the spaces between neighboring phospholipid molecules left by the kinks in their unsaturated hydrocarbon tails. In this way, cholesterol tends to stiffen the bilayer, making it more rigid and less permeable. For all cells, membrane fluidity is important for many reasons. It enables membrane