Cataract, primary: A cataract that develops independently of other diseases. A primary cataract is in contrast to a secondary cataract, one that is secondary to another disease.
- Cataract, secondary
Cataract, secondary: A cataract that develops secondary to another disease or surgery. The other disease may, for example, be glaucoma or retinal detachment. A secondary cataract is in contrast to a primary cataract, one that develops independently of any other disease.
- Cataract, supranuclear
Cataract, supranuclear: A cataract just above the center (the nucleus) of the lens. See: Cataract.
Catatonic: 1. Characterized by marked motor abnormalities including immobility (catalepsy or stupor), excessive motor activity (purposeless agitation), extreme negativism, mutism, posturing or stereotyped movements, echolalia, and/or echopraxia. 2. A person with catatonia or catatonic schizophrenia.
Catechol-O-methyltransferase: COMT. An enzyme that catalyzes the degradation of catecholamines, including the neurotransmitters dopamine, epinephrine, and norepinephrine. COMT is also important in the metabolism of catechol drugs used in the treatment of hypertension, asthma, and Parkinson disease. A genetic polymorphism (a common normal variant) in COMT contributes to the responses to pain and stress.
Catecholamine: Pronounced cat·e·chol·amine. An amine derived from the amino acid tyrosine — examples include epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine — that act as hormones or neurotransmitters. There are a number of disorders involving catecholamines, including neuroblastoma, pheochromocytoma, chemodectina, the familial paraganglioma syndrome, dopamine-�-hydroxalase deficiency, and tetrahydrobiopterin deficiency Neuroblastoma is the second most common solid […]