| UGIS | upper gastrointestinal series |
|---|---|
| ACS | acrocallosal syndrome; acrocephalosyndactyly; acute chest syndrome; acute confusional state; Alcon C... |
| AHS | Academy of Health Sciences; African horse sickness; alveolar hypoventilation syndrome; American Hear... |
| AOS | American Ophthalmological Society; American Otological Society; anodal opening sound; anterior [o]es... |
| ARS | acquiescence response scale; adult Reye's syndrome; alcohol-related seizures; alizarin red S; Americ... |
| SAEM | Society for Academic Emergency Medicine |
|---|---|
| S.I.O.P. | Society of Paediatric Oncology |
| SIOP | Society of Pediatric Oncology |
| STS | Society of Thoracic Surgeons |