Alanine aminotransferase (ALT): An enzyme that is normally present in liver and heart cells. ALT is released into blood when the liver or heart is damaged. The blood ALT levels are thus elevated with liver damage (for example, from viral hepatitis) or with an insult to the heart (for example, from a heart attack). Some medications can also raise ALT levels. ALT is also called serum glutamic pyruvic transaminase (SGPT).
- Alarm clock headache
Alarm clock headache: A relatively rare form of headache in which the patient is awakened from sleep at the same time every night, usually between 1 and 3 o’clock, with intense dull or throbbing pain over the whole head. Each episode may last up to 1 hour and be associated with nausea. Similar episodes may […]
Alb-: Prefix from the Latin “albus” meaning “white.” As in albino and albinism. The term “albino” was first applied by the Portuguese to “white” people they encountered in West Africa. Those “white” people probably had partial or complete albinism, an inherited lack of pigment in the skin, hair, and eyes.
Albinism: A group of genetic disorders in which there is partial or total lack of the pigment melanin in the eyes, skin, and hair. See also: Albinism, oculocutaneous; Hermansky-Pudlak syndrome.
- Albinism and hemorrhagic diathesis
Albinism with hemorrhagic diathesis and pigmented reticuloendothelial cells: See: Hermansky-Pudlak syndrome.
- Albinism, oculocutaneous
Albinism, oculocutaneous: An hereditary disorder characterized by deficiency of the pigment melanin in the eyes, skin and hair. The lack of eye pigment causes photophobia (sensitivity to light), nystagmus, and decreased visual acuity. Oculocutaneous albinism is conventionally classified as to whether it is tyrosinase-negative or tyrosinase-positive. In the tyrosinase-negative class, there is absence of the […]