Dictionary

AZT Azidothymidine, now renamed zidovudine, but still best known by the abbreviation AZT. This antiviral drug is prescribed, usually in combination with protease inhibitors and other drugs, to treat HIV infection in patients with AIDS.

B cell A type of white blood cell that has an important role in producing antibodies for the immune system. B cells are lymphocytes that mature in the bone marrow (as opposed to T cells, lymphocytes that mature in the thymus). Many B cells go on to become plasma cells and produce antibodies (immunoglobulins); some…

B variant GM2-gangliosidosis See Tay-Sachs disease.

B. quintana See Bartonella quintana.

Babinski reflex A reflex used to determine adequacy of the higher (central) nervous system. The Babinski reflex is obtained by stimulating the outside of the sole of the foot, causing extension of the big toe while fanning the other toes. The examiner begins the stimulation at the heel and goes forward to the base of…

baby teeth See primary teeth.

auscultate To listen, for diagnostic purposes, to the sounds made by the internal organs of the body. For example, nurses and physicians auscultate the lungs and heart of a patient by using a stethoscope placed on the patient’s chest or back.

autism A spectrum of neuropsychiatric disorders characterized by deficits in social interaction and communication and by unusual and repetitive behavior. Some, but not all, people with autism are nonverbal. Autism is normally diagnosed before age 6, and it may be diagnosed in infancy in some cases. The cause of autism is currently unknown, although it…

autistic disorder Autism, particularly the most serious form of autism.

autoantibody An antibody that is directed against the patient’s own body. Autoantibodies play a causative role in a number of diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and Hashimoto disease. See also autoimmune disorder.

autoclave A chamber for sterilizing with steam under pressure. The original autoclave was essentially a pressure cooker in which steam tightened the lid.

autogenous Self-produced.