(dĭ-fūz′) 1. To remove a fuse from an explosive device. 2. To make a crisis or other situation less dangerous or inflammatory.
The ability of structurally differing molecules to perform overlapping, redundant, or equivalent functions. This ability is a characteristic of some nucleic acid codons (which code for the same amino acid despite having differing base pairs) and some molecules used by the immune system.
(dē-jĕn′ĕ-rāt″) [L. degenerare, to fall from one’s ancestral quality] 1. To deteriorate. 2. Pert. to deterioration.
(dē-jen″ĕ-rā′shŏn) [de- + generation] Structural or functional breakdown, e.g., of a protein, a cell, a tissue, an organ, or an organism. SEE: regeneration. degenerative (de-jen′ĕ-rāt″iv, de-jen′ĕ-ră-tiv), adj.
age-related macular d. Macular d.
amyloid d. Degeneration of organs or tissues when amyloid, a protein/polysaccharide complex, deposits in them. On microscopic examination, the deposits are waxy and translucent and have a hyaline appearance. The liver, spleen, and kidneys are usually involved, but any tissue may be infiltrated.
ballooning d. Ballooning.
corticobasal d. A neurological disorder in which brain cells atrophy and die in the basal ganglia and the cortex of the brain. The disease produces symptoms similar to those found in Parkinson’s disease but does not respond to parkinsonian medications.
cystic d. Formation of cysts accompanied by degeneration.
fatty d. of the heart An abnormal accumulation of triglycerides in the myocardium, seen on biopsy specimens as clear vacuoles or droplets. SYN: fatty infiltration of the heart.
frontotemporal lobar d. Pick disease.
granulovacuolar d. A pathological finding in the brain cells of some patients with Alzheimer dementia in which the neuronal cytoplasm is partly replaced by cavities that contain particles resembling grit or sand.
hepatolenticular d. Wilson disease.
hyaline d. Degeneration in which the tissues assume a homogeneous, glassy appearance. It is caused by hyaline deposits replacing musculoelastic elements of blood vessels with a firm, transparent substance that causes loss of elasticity. It is responsible for hardening of the arteries and is often followed by calcification or deposit of lime salts in dead tissue. Calcification also may result in concretions. SYN: vitreous degeneration.
hydropic d. Degeneration in cells marked by the appearance of water droplets in the cytoplasm.
lattice d. Degeneration or thinning of the retina at its margins, a common condition that affects about 10% of the population. The condition is usually bilateral and is often asymptomatic although affected people may complain of seeing ...