Glossary of Medical Terms

A substance that works against many types of bacteria and includes streptomycin, gentamicin, and neomycin. An aminoglycoside antibiotic is used to treat bacterial infections.

A drug used under the brand names Ameluz and Levulan Kerastick to treat actinic keratosis (a skin condition that may become cancer). It is also used under the brand name Gleolan as an imaging agent during surgery for certain types of brain tumors. Aminolevulinic acid hydrochloride is also being studied in the treatment of other conditions and types of cancer. When aminolevulinic acid hydrochloride is taken up by abnormal cells, including cancer cells, and then exposed to certain types of light, it becomes active and kills the cells. It may also help find some types of cancer cells when they are exposed to certain types of light. Aminolevulinic acid hydrochloride is a type of photosensitizing agent.

An anticancer drug that belongs to the family of drugs called antimetabolites.

A drug used to treat certain types of abnormal heart rhythms that have not gotten better with other drugs. Amiodarone hydrochloride affects the electrical activity of the heart. It is a type of antiarrhythmic agent. Also called Corderone.

A drug that is used to treat depression and may be given to treat anxiety, sleep disorders, and pain. It is also being studied in an oral or gel form in the treatment of nerve pain caused by chemotherapy. Amitriptyline hydrochloride is a type of tricyclic antidepressant.

An aggressive (fast-growing) disease in which too many myeloblasts (immature white blood cells that are not lymphoblasts) are found in the bone marrow and blood. Also called acute myeloblastic leukemia, acute myelogenous leukemia, acute myeloid leukemia, acute nonlymphocytic leukemia, and ANLL.

A type of acute myeloid leukemia in which at least 20% of a patient’s blood or bone marrow is myeloblasts (immature white blood cells) and the patient has one of the following conditions: 1) has had myelodysplastic syndrome (MDS) or a myelodysplastic/myeloproliferative neoplasm (MDS/MPN) before, 2) cells that have changes in certain chromosomes that are similar to those found in MDS, or 3) at least 50% of the cells (of at least two types of blood cells) are abnormal. AML-MRC usually occurs in older adults and has a poor prognosis. Also called acute myeloid leukemia with myelodysplasia-related changes.

A gas made of nitrogen and hydrogen. It has a strong odor and can irritate the skin, eyes, nose, throat, and lungs. Ammonia is made by bacteria and decaying plants and animals and is found in water, soil, and air. Ammonia is also made by the body when proteins break down. In the laboratory, ammonia can be changed to a liquid and used in medicines, fertilizers, household cleaning liquids, and other products. It is also added to cigarettes to increase the effect of nicotine on the body.

A substance being studied in the treatment of many types of cancer. Ammonium tetrathiomolybdate removes extra copper from the body. Removing the copper may prevent the growth of new blood vessels that tumors need to grow and may kill cancer cells. Ammonium tetrathiomolybdate is a type of chelating agent and a type of antiangiogenesis agent.

The clear or slightly yellow fluid that surrounds and protects an unborn baby as it grows during pregnancy. Amniotic fluid cushions the baby and helps keep the temperature in the womb constant. It also helps the growing baby’s lungs, digestive system, and bones develop properly. Amniotic fluid contains some of the baby’s cells and other substances. Samples of amniotic fluid may be taken to check the health of the baby and to test for genetic changes that may be a sign of a genetic disease or condition. Amniotic fluid also may be used to learn the sex of the baby.