autonomic nervous system
The part of the nervous system that controls muscles of internal organs (such as the heart, blood vessels, lungs, stomach, and intestines) and glands (such as salivary glands and sweat glands). One part of the autonomic nervous system helps the body rest, relax, and digest food and another part helps a person fight or take flight in an emergency. Also called ANS and involuntary nervous system.
autonomic nervous system disorder
A condition that affects the part of the nervous system called the autonomic nervous system (ANS). The ANS controls many important automatic body processes, such as blood pressure, heart rate, breathing, body temperature, digestion, sweating, urination, and sexual response. An autonomic nervous system disorder can affect all or part of the ANS and can cause serious problems, such as heart and blood pressure problems, trouble breathing or swallowing, or impotence in males. There are many different types of autonomic nervous system disorders. They may be inherited or caused by injury or by conditions such as diabetes, Parkinson disease, autoimmune disease, and alcoholism. Sometimes, the cause is not known. Also called dysautonomia.
autophagy
A process by which a cell breaks down and destroys old, damaged, or abnormal proteins and other substances in its cytoplasm (the fluid inside a cell). The breakdown products are then recycled for important cell functions, especially during periods of stress or starvation. Autophagy also helps destroy bacteria and viruses that cause infection and may prevent normal cells from becoming cancer cells. Once cancer has formed, autophagy may protect the cancer cells by providing extra nutrients to them or by keeping anticancer drugs or other substances from destroying them. Autophagy may also affect the body’s immune response against viruses, bacteria, and cancer cells.
autosomal dominant inheritance
One of the ways a genetic trait or a genetic condition can be passed down (inherited) from parent to child. In autosomal dominant inheritance, a genetic condition can occur when the child inherits one copy of a mutated (changed) gene from one parent. A child who has a parent with the mutated gene has a 50% chance of inheriting that mutated gene.
autosomal recessive inheritance
One of the ways a genetic trait or a genetic condition can be passed down (inherited) from parent to child. In autosomal recessive inheritance, a genetic condition occurs when the child inherits one mutated copy of a gene from each parent. The parents usually do not have the condition. The parents are called carriers because they each carry one copy of the mutated gene and can pass it to their children.
Avage
A drug used on the skin to treat several skin conditions. It is also being studied in the treatment of basal cell skin cancer and basal cell nevus syndrome. Avage is related to vitamin A and is made in the laboratory. It turns on a gene that may help stop the growth of skin cancer cells. Avage is a type of synthetic retinoid. Also called tazarotene and Tazorac.
Avandia
A drug that helps control the amount of glucose (sugar) in the blood and is being studied in the prevention and treatment of some types of cancer. Avandia stops cells from growing and may prevent the growth of new blood vessels that tumors need to grow. It is a type of thiazolidinedione and a type of antiangiogenesis agent. Also called rosiglitazone maleate.
avapritinib
A drug used to treat gastrointestinal stromal tumor (GIST) that cannot be removed by surgery or has spread to other parts of the body. It is used in adults whose cancer has certain mutations (changes) in a gene called PDGFRA. It is also being studied in the treatment of other types of cancer. Avapritinib blocks certain proteins made by the mutated PDGFRA gene, which may help keep cancer cells from growing. It is a type of tyrosine kinase inhibitor. Also called Ayvakit.
avascular necrosis
A condition in which there is a loss of blood flow to bone tissue, which causes the bone to die. It is most common in the hips, knees, shoulders, and ankles. It may be caused by long-term use of steroid medicines, alcohol abuse, joint injuries, and certain diseases, such as cancer and arthritis. It may also occur at some point in time after cancer treatment that included methotrexate, bisphosphonates, or corticosteroids. Also called aseptic necrosis, ischemic necrosis, and osteonecrosis.