| undifferentiated | <embryology, pathology> An immature, embryonic or primitive cell. It has a non-specific appearance with multiple non-specific activities and functions poorly. See: differentiate, dedifferentiate. (16 Dec 1997) |
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| undifferentiated abdominal malignancy | <radiology> Large soft-tissue masses, multiple linear or nodular calcific densities, can coalesce to form conglomerate masses (12 Dec 1998) |
| undifferentiated cell | A primitive cell that has not assumed the morphologic and functional characteristics it will later acquire. (05 Mar 2000) |
| undifferentiated cell adenoma | <tumour> An adenoma of the hypophysis composed of cells for which there is no overt evidence or hormone production, but which usually produces hypopituitarism and visual disturbances by compression of adjacent structures; approximately one third of these tumours have cells with abundant mitochondria (oncocytes) that are somewhat larger than the monocytic null cells. Synonym: undifferentiated cell adenoma. (05 Mar 2000) |
| undifferentiated sarcoma of liver | <radiology> Kiddies, age 4 - 15 yrs, M = F, complex hepatic mass, often hypovascular, most in right lobe, large ( more than 10 cm), ** Differential diagnosis: embryonal rhabdomyosarcoma (12 Dec 1998) |
| undifferentiated type fever | A term applied to illnesses resulting from infection by any one of the arboviruses pathogenic for man, in which the only constant manifestation is fever; rash, lymphadenopathy, or arthralgia (alone or in combination) may occur in some individuals but not in others; some arboviruses may induce infections in which undifferentiated type fever is the only manifestation, whereas other arboviruses may induce in some persons only undifferentiated fever, and in other persons similar fever followed by secondary manifestations, e.g., a haemorrhagic fever or encephalitis. (05 Mar 2000) |
| lymphoma, undifferentiated | A form of lymphoma in which relatively large stem cells with large nuclei, pale, scanty cytoplasm, and indistinct borders are predominant. The cells are undifferentiated, i.e., show no morphologic evidence of maturation toward lymphocytes or histiocytes. (12 Dec 1998) |
| abdomen, acute | Clinical syndrome characterised by abdominal pain of great severity associated with other symptoms and signs, usually those of acute peritonitis, which might well be the result of a ruptured abdominal viscus or a similar abdominal catastrophe requiring urgent surgical operation. (12 Dec 1998) |
| acute | 1. Sharp, poignant. 2. Having a short and relatively severe course. Origin: L. Acutus = sharp (18 Nov 1997) |
| acute abdomen | Any serious acute intra-abdominal condition (such as appendicitis) attended by pain, tenderness, and muscular rigidity, and for which emergency surgery must be considered. Synonym: surgical abdomen. (05 Mar 2000) |
| acute abscess | A recently formed abscess with little or no fibrosis in the wall of the cavity. Synonym: hot abscess. (05 Mar 2000) |
| acute adrenal crisis | <endocrinology> An abrupt life-threatening state which is caused by insufficient production of cortisol by the adrenal gland. A typical finding in Addison's disease. Individuals who have been taking corticosteroids (glucocorticoids) for a prolonged period of time (weeks to months) are at risk for acute adrenal crisis if the medication is stopped abruptly. For this reason, corticosteroid medication are withdrawn slowly on a diminishing dosing schedule. Symptoms include low blood pressure (shock), weakness, headache, vomiting, fever chills, tachycardia and sweating. Treatment includes blood pressure support and intravenous hydrocortisone. (27 Sep 1997) |
| acute adrenocortical insufficiency | Severe adrenocortical insufficiency when an intercurrent illness or trauma causes an increased demand for adrenocortical hormones in a patient with adrenal insufficiency due to disease or use of relatively large amounts of similar hormones as therapy; characterised by nausea, vomiting, hypotension, and frequently hyperthemia, hyponatraemia, hyperkalaemia, and hypoglycaemia; can be fatal if untreated. Synonym: addisonian crisis, adrenal crisis, Bernard-Sergent syndrome. (05 Mar 2000) |
| acute African sleeping sickness | A disease of humans caused by Trypanosoma brucei rhodesiense in eastern Africa from Ethiopia and Uganda south to Zimbabwe; it is clinically similar to Gambian trypanosomiasis but of shorter duration and more acute in form; patients suffer repeated episodes of pyrexia, become anaemic, and die commonly from cardiac failure. Synonym: acute African sleeping sickness, acute trypanosomiasis, East African sleeping sickness, East African trypanosomiasis. (05 Mar 2000) |
| acute alcoholism | A temporary deterioration in mental function, accompanied by muscular incoordination and paresis, induced by the rapid ingestion of alcoholic beverages. Synonym: intoxication. (05 Mar 2000) |