| Sanarelli-Shwartzman phenomenon | When both the primary injection of endotoxin-containing filtrate and the secondary injection are given intravenously 24 hours apart, the animal usually dies within 24 hours after the second inoculation; the characteristic lesions in the rabbit include widespread haemorrhages in the lung, liver, and other organs and bilateral cortical necrosis of the kidney. This reaction has no immunological basis. Synonym: Sanarelli phenomenon, Sanarelli-Shwartzman phenomenon. (05 Mar 2000) |
|---|---|
| Schellong-Strisower phenomenon | A reduction of the systolic blood pressure, accompanied sometimes by vertigo, on rising from the horizontal to the erect posture. (05 Mar 2000) |
| Schiff-Sherrington phenomenon | When the spinal cord is transected in the midthoracic region or a little lower, the stretch and other postural reflexes of the upper extremity become exaggerated; if the transection is made in the sacral cord, a similar effect is observed in the lower limbs. The effect is regarded as a release phenomenon, i.e., release from an inhibitory influence normally exerted by the spinal segments below the transection. (05 Mar 2000) |
| Schuller's phenomenon | In cases of functional hemiplegia the patient usually turns to the sound side in walking, but to the affected side in case of an organic lesion. (05 Mar 2000) |
| Schultz-Charlton phenomenon | The specific blanching of a scarlatinal rash at the site of intracutaneous injection of scarlatina antiserum. Synonym: Schultz-Charlton phenomenon. (05 Mar 2000) |
| pseudo-Graefe's phenomenon | Retraction of the upper eyelid on downward movement of the eyes. (05 Mar 2000) |
| Hill's phenomenon | <clinical sign> In aortic insufficiency, greater systolic blood pressure in the legs than in the arms; normal arterial systolic pressure in the leg is 10 to 20 mm of Hg above that in the arm, whereas in aortic insufficiency the difference may be 60 to 100 mm of Hg. Synonym: Hill's phenomenon. (05 Mar 2000) |
| hip-flexion phenomenon | When a hemiplegic attempts to rise from a lying posture, the hip on the paralysed side is flexed first; the same movement takes place on lying down. (05 Mar 2000) |
| hip phenomenon | Twitching of the glutei muscles when firm pressure is made on the nates, in cases of spastic paralysis. Synonym: hip phenomenon. (05 Mar 2000) |
| psi phenomenon | A phenomenon that includes both psychokinesis and extrasensory perception; the extrasensory mental processes involved in the alleged ability to send or receive telepathic messages. (05 Mar 2000) |
| Hoffmann's phenomenon | Excessive irritability of the sensory nerves to electrical or mechanical stimuli in tetany. (05 Mar 2000) |
| Purkinje's phenomenon | <ophthalmology> In the light-adapted eye, the region of maximal brightness is in the yellow; in the dark-adapted eye, the region of maximal brightness is in the green. Synonym: Purkinje effect, Purkinje shift. (05 Mar 2000) |
| hunting phenomenon | An unusual reaction of digital blood vessels exposed to cold; vasoconstriction is alternated with vasodilation in irregular repeated sequences, in an apparent hunting of equilibrium of skin temperature. Synonym: hunting phenomenon. (05 Mar 2000) |
| Hunt's paradoxical phenomenon | In dystonia musculorum deformans, if an attempt is made at plantar flexion of the foot when the foot is in dorsal spasm the only response is an increase of the extensor, or dorsal, spasm; if, however, the patient is told to extend the foot which is already in a state of strong dorsal flexion, there will be a sudden movement of plantar flexion; the same phenomenon, mutatis mutandis, is observed when there is a condition of strong plantar flexion. (05 Mar 2000) |
| Sherrington phenomenon | After the muscles of the leg have been deprived of their motor innervation by sectioning the ventral roots containing fibres for the sciatic nerve, and allowing time for the degeneration of the fibres to occur, stimulation of the sciatic nerve causes slow contraction of the muscles. (05 Mar 2000) |