Day sight: Night blindness. Listed in medical dictionaries under “Nyctalopia” from the Greek “nyct’ (night) + “aloas” (obscure or blind) + “opsis” (vision), the condition involves impaired vision in dim light and in the dark (but normal sight in bright light), due to impaired function of specific vision cells (the “rods”) in the retina. Day sight (night blindness) is a classic symptom resulting from deficiency of vitamin A. It was discovered by the English physician William Heberden (1710-1801) who described other medical disorders of importance including angina pectoris (chest pain that is often severe and crushing, due to an inadequate supply of oxygen to the heart muscle) and osteoarthritis of the small joints with nodules (Heberden’s nodes) in and about the last joint of the finger. Day sight (night blindness) is also called nocturnal amblyopia and nyctanopia.
DBT: Dialectical behavioral therapy. Developed by Marsha Linehan for treatment of borderline personality disorder.
DCIS: Ductal carcinoma in situ. A precancerous condition characterized by the clonal proliferation of malignant-looking cells in the lining of a breast duct without evidence of spread outside the duct to other tissues in the breast or outside the breast. DCIS is clearly the precursor (forerunner) of invasive breast cancer. This is evident from the […]
- DDH (developmental dislocation of the hip)
DDH (developmental dislocation of the hip): The abnormal formation of the hip joint in which the ball at the top of the thighbone (the femoral head) is not stable within the socket (the acetabulum). The ligaments of the hip joint may also be loose and stretched. The degree of instability or looseness varies. A baby […]
- de Lange syndrome
de Lange syndrome: Is a rare genetic disorder with multiple malformations and mental retardation of unknown origin. de Lange syndrome is recognized by the presence of: Prenatal and postnatal growth retardation; Delayed development and mental retardation; Abnormally small head (microcephaly); Hair low on the nape of the neck; Characteristic facial appearance with Low-set ears, Hair […]
- de Musset sign
de Musset sign: Rhythmic nodding or bobbing of the head in synchrony with the heart beat, a sign of aortic insufficiency –incompetence of the aortic valve with aortic regurgitation. The causes include syphilitic aortitis, rheumatic fever, and aortic aneurysm. Named after the French Romantic poet and playwright Alfred de Musset (1810-1857).