| PASA | para-aminosalicylic acid; primary acquired sideroblastic anemia; proximal articular set angle |
|---|---|
| POS | periosteal osteosarcoma; physician order set; point of service; polycystic ovary syndrome; psychoorg... |
| PUMS | patient utility measurement set; permanently unfit for military service |
| RISC | reduced-instruction-set computer |
| SET | surrogate embryo transfer; systolic ejection time |
low blood pressure
| t-lymphocytopenia, idiopathic CD4-positive | Reproducible depletion of CD4+ lymphocytes below 300 per cubic millimeter in the absence of HIV infection or other known causes of immunodeficiency. This is a rare, heterogeneous syndrome and does not appear to be caused by a transmissible agent. (12 Dec 1998) |
|---|---|
| eyepiece, positive | <microscopy> An eyepiece in which the real image of the object is formed below the lower lens element, of the eyepiece. (05 Aug 1998) |
| false positive | <statistics> A test result that is read as positive when it is really negative. (27 Sep 1997) |
| false-positive reaction | <statistics> An erroneous or mistakenly positive response. Positive test results in subjects who do not possess the attribute for which the test is conducted. The labeling of healthy persons as diseased when screening in the detection of disease. (05 Mar 2000) |
| leukaemia, calla-positive | Acute leukaemia in which lymphocytes are positive for the common acute lymphoblastic leukaemia antigen (calla). (12 Dec 1998) |
| abdominal pressure | Pressure surrounding the bladder; estimated from rectal, gastric, or intraperitoneal pressure. (05 Mar 2000) |
| absolute pressure | Pressure measured with respect to zero pressure. Compare: gauge pressure. (05 Mar 2000) |
| acoustic pressure | In ultrasound, the instantaneous value of the total pressure minus the ambient pressure; unit is pascal (Pa). (05 Mar 2000) |
| air pressure | The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment. (12 Dec 1998) |
| atmospheric pressure | The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned. (12 Dec 1998) |
| back pressure | Pressure exerted upstream in the circulation as a result of obstruction to forward flow, as when congestion in the pulmonary circulation results from stenosis of the mitral valve or failure of the left ventricle. (05 Mar 2000) |
| back-pressure renal atrophy | <radiology> Caliectasis without obstruction, due to repeated episodes of obstruction, gradual loss of renal pyramids (12 Dec 1998) |
| barometric pressure | The absolute pressure of the ambient atmosphere, varying with weather, altitude, etc.; expressed in millibars (meteorology) or mm Hg or torr (respiratory physiology); at sea level, one atmosphere (atm, 760 mm Hg or torr) is equivalent to: 14.69595 lb/sq in, 1013.25 millibars, 1013.25 × 106 dynes/cm2, and, in SI units, 101,325 pascals (Pa). Synonym: atmospheric pressure. (05 Mar 2000) |
| bile duct pressure | <radiology> Normal: 15-20 cm H2O (12 Dec 1998) |
| biting pressure | Any force exerted upon the occlusal surfaces of teeth. Synonym: biting pressure. (05 Mar 2000) |