Webster's New World Medical Dictionary

ASD
Atrial septal defect.
aseptic
Free from infection, sterile. See also 
anti-
septic.
aseptic necrosis
See 
avascular necrosis.
ASO
Antistreptolysin-O, a blood test that looks for
antibodies to the streptococcus A bacteria. Also
abbreviated ASLO.
aspartate aminotransferase
An enzyme that is
normally present in liver and heart cells that is
released into the blood when the liver or heart is
damaged. Abbreviated AST. Some medications can
also raise blood AST levels. Also known as serum
glutamic oxaloacetic transaminase (SGOT).
Asperger syndrome
A disorder related to
autism characterized by obsessive interests and
behavior, but without speech delay or mental retar-
dation. Other features of Asperger syndrome
include physical clumsiness, and/or moderate to
severe social deficits. Asperger syndrome is the
mildest of and at the highest functioning end of the
spectrum of pervasive developmental disorders (the
autism spectrum). Persons with Asperger syndrome
have deviations or abnormalities in three broad
aspects of development: social relatedness and
social skills, the use of language for communicative
purposes, and certain behavioral and stylistic char-
acteristics that involve repetitive or perseverative
features and a limited but intense range of interests.
See also 
autism.
aspergillosis
Infection with the fungus
Aspergillus, seen especially in people with compro-
mised immune systems in whom there may be inva-
sive lung infection and sometimes spread to other
tissues, including the brain, the skin, and bones.
Aspergillosis also causes allergic sinusitis and aller-
gic bronchopulmonary disease.
Aspergillus
A family of fungal organisms and
molds, some of which can cause disease.