Dictionary

ALT Alanine aminotransferase.

ALS Amyotropic lateral sclerosis, Lou Gehrig’s disease.

Alport syndrome A hereditary condition characterized by kidney disease, deafness, and sometimes eye defects. Alport syndrome involves inflammation of the kidney (nephritis), often progressing to kidney failure, and sensory nerve hearing loss. Progression to kidney failure is gradual and usually occurs in males before 50 years of age.

alpha-fetoprotein A plasma protein normally produced by a fetus, principally in the fetus’s liver, the fetal gastrointestinal tract, and the yolk sac, a structure temporarily present during embryonic development. Abbreviated AFP. The level of AFP is typically high in the fetus’s blood. It goes down after birth. By 1 year of age, it is virtually…

alpha-1 antitrypsin deficiency An inherited disorder characterized by a lack of the alpha-1 antitrypsin protease inhibitor. Alpha-1 antitrypsin deficiency leads to damage of various organs, especially the lung and liver. Symptoms may become apparent at a very early age or anytime later, manifesting as shortness of breath due to emphysema or as liver symptoms such…

Alpha Omega Alpha An honor society, the medical school equivalent of Phi Beta Kappa of undergraduate school.

alpha interferon One of the three main classes of interferons, which are specialized proteins (lymphokines) produced by the body in response to microbial infection that interfere with the multiplication of viruses in cells. The other two main classes are called beta interferon and gamma interferon. See also interferon; interferon therapy.

alpha error The statistical error made in testing a hypothesis when it is concluded that a result is positive, but it really is not. Also known as false positive.

alpha cell, pancreatic A type of cell found in areas within the pancreas called the islets of Langerhans. Alpha cells make and release glucagon, which raises the level of glucose (sugar) in the blood.

alopecia universalis Loss of all hair on the entire body.

alopecia capitis totalis Loss of all scalp hair, with normal hair elsewhere on the body remaining.

alopecia areata Patchy baldness that typically begins with rapid hair loss on discrete areas of the scalp and sometimes progresses to complete baldness and even loss of body hair. The characteristic diagnostic finding is short, broken hairs called “exclamation point” hairs. Alopecia areata affects both males and females and, most often, children and young adults….