Dictionary

stereotactic Referring to precise positioning in three-dimensional space. For example, biopsies, surgery, or radiation therapy can be done stereotactically.

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…

stenosis A narrowing. For example, aortic stenosis is a narrowing of the aortic valve in the heart.

stem cell transplantation The use of stem cells as a treatment for cancer or other illness. The stem cells are removed (or obtained from a donor) first. Before the transplant is done, the patient receives high-dose chemotherapy and/or radiation therapy to destroy diseased cells. Then the stem cells are returned to the patient, where they…

stem cell harvest, peripheral blood A technique for obtaining stem cells from the patient’s blood for use in bone marrow transplantation. The stem cells are lured out of the bone marrow with a special regimen of drugs. The blood is then filtered through a machine, and the stem cells are skimmed off. They can be…

stem cell harvest Obtaining stem cells for use in cancer or other treatment. Usually the cells are removed from the patient’s own bone marrow. Stem cells can be harvested from the blood or bone marrow. Umbilical cords have been saved as a future source of stem cells for the baby.

stem cell One of the human body’s master cells, with the ability to grow into any one of the body’s more than 200 cell types. Stem cells are unspecialized (undifferentiated) cells that are characteristically of the same family type (lineage). They retain the ability to divide throughout life and give rise to cells that can…

Stein-Leventhal syndrome See polycystic ovarian syndrome.

STDs in women See sexually transmitted disease in women.

STDs in men See sexually transmitted disease in men.

STD Sexually transmitted disease.

status epilepticus An epileptic seizure that lasts more than 30 minutes or a constant or near-constant state of having seizures. Status epilepticus is a health crisis and requires immediate treatment with antiseizure medications. See also epilepsy; seizure disorder.