stent A tube designed to be inserted into a vessel or passageway to keep it open. Stents are inserted into narrowed coronary arteries to help keep them open after balloon angioplasty. The stent then allows the normal flow of blood and oxygen to the heart. Stents placed in narrowed carotid arteries (the vessels in the…
stereotactic Referring to precise positioning in three-dimensional space. For example, biopsies, surgery, or radiation therapy can be done stereotactically.
stereotactic surgery Surgery in which a system of three-dimensional coordinates is used to locate the site to be operated on.
stereotaxis Use of a computer and scanning devices to create three-dimensional pictures. Stereotaxis can be used to direct a biopsy, external radiation, or the insertion of radiation implants.
sternotomy A surgical incision made through the breastbone (sternum), for example, as performed for access to the heart during surgery.
squamous cell One type of epithelial, or lining, cell that has a flat appearance resembling a fish scale when viewed microscopically. Squamous cells make up most of the outer layer of the skin (epidermis). They are also found in the oral cavity, espohagus, vagina, and uterine cervix.
squamous intraepithelial lesion An abnormal growth of the squamous cells that normally are found on the uterine cervix. Abbreviated SIL. The changes are described as low grade (LGSIL) or high grade (HGSIL), depending upon how abnormal the cells look. Squamous intraepithelial lesions can be a precursor of cervical cancer; treatment of high grade SIL is…
SSPE Subacute sclerosing panencephalitis.
SSRI Selective serotonin reuptake inhibitor, one of a family of antidepressant medications (brand names: Celexa, Luvox, Paxil, Prozac, Zoloft) that affect the neurotransmitter serotonin.
St. Anthony’s fire One of several conditions characterized by intense inflammation of the skin, such as from erysipelas or ergotism. Erysipelas is a type of spreading hot, bright-red strep skin infection. Ergotism is an intensely painful burning sensation in the limbs and extremities caused by ergotamines from a fungus (Claviceps purpurea) that can contaminate rye…
St. John’s wort A flowering plant, Hypericum perforatum, also known as Perforate St. John’s wort, that has long been believed to have medicinal qualities. There is some evidence that St. John’s wort may be useful in diminishing depression, but it is not a proven remedy for depression. Sun sensitivity, fatigue, stomach upset, and allergic reactions…
stage 1 A distinct phase in the course of a disease (or any biological process). 2 The extent of a cancer, and especially whether the disease has spread from the original site to other parts of the body. See also staging.