| arrhythmias, rapid | Abnormally rapid heart rhythms, medically termed tachycardia. (12 Dec 1998) |
|---|---|
| rapid canities | Whitening of hair overnight or over a few days; in the latter case, may be seen in alopecia areata, when surviving pigmented hairs are preferentially shed from gray hair. (05 Mar 2000) |
| rapid decompression | Sudden severe expansion of gases due to a reduction in ambient pressure. Synonym: explosive decompression. (05 Mar 2000) |
| rapid demineralization | <radiology> Immobilization atrophy, Sudeck's atrophy (reflex sympathetic dystrophy), rheumatoid or psoriatic (rarely in inflammatory states) see also: vanishing bone (spontaneous osteolysis) syndromes (12 Dec 1998) |
| rapid eye movements | Symmetrical quick scanning movement's of the eyes occurring many times during sleep in clusters for 5 to 60 minutes; associated with dreaming. (05 Mar 2000) |
| rapid eye movement sleep | REM sleep, that state of deep sleep in which rapid eye movements, alert EEG pattern, and dreaming occur; several central and autonomic functions are distinctive during this state. (05 Mar 2000) |
| rapid film changer | A device that moves film for radiographic studies that require rapid serial X-ray exposures, such as angiography. Synonym: rapid film changer, serial film changer. (05 Mar 2000) |
| rapid plasma reagin | <investigation> The rapid plasma reagin test is similar to the VDRL test for diagnosing syphilis. This blood test is designed to detect an antibody substance in the bloodstream when syphilis infection is present. Early syphilis infections may be RPR negative. See: VDRL (17 Dec 1997) |
| rapid plasma reagin test | A group of serologic test's for syphilis in which unheated serum or plasma is reacted with a standard test antigen containing charcoal particles; positive test's yield a flocculation. A modification, called the RPR (circle) card test, is widely used as a screening test. Synonym: RPR test. (05 Mar 2000) |
| non-rapid eye movement | Slow oscillation of the eyes during sleep. (05 Mar 2000) |
| Field's rapid stain | <technique> A stain to permit rapid positive diagnosis of malaria in endemic areas by using thick films; it employs methylene blue and azure B in a phosphate buffer, with the preparation counterstained by eosin in a phosphate buffer. (05 Mar 2000) |
| abortion rate | The number of abortions per 1000 terminated pregnancies during a given period of time. (05 Mar 2000) |
| age-specific rate | A rate for a specified age group, in which the numerator and denominator refer to the same age group. (05 Mar 2000) |
| attack rate | A cumulative incidence rate used for particular groups observed for limited periods under special circumstances, such as during an epidemic. (05 Mar 2000) |
| average flow rate | <physiology> The flow rate determined by dividing the total volume passed in a time period divided by the time period, usually quoted in mls per minute. (05 Mar 2000) |