DEGENERATION

n. De-jean-u5r-a's hu3n. Gr.,vo0aea. Lat., degeneratio (from degenerare, to degenerate). Fr., degeneration, degenerescence. Ger., D., Entartung. It., degenerazione. Sp., degeneration. Lo of race characteristics; of ti ue, structural impairment; in botany, the transformation of parts so as to render a plant asymmetrical or irregular in form (as when undeveloped stamens become filiform bodies or scales; stamens and pistils, petals; or florets, leaves). [B, 77 (a, 24).] Acute fatty d. A disease rarely observed in man, but not infrequently seen among animals. In colts it is known as foot-halt. It occurs in puerperal women in the form of acute yellow atrophy of the liver, [a, 25.] Adipose d. SeeFattyd. Albuminoid d. SeeAmyloidd. Albuminous d. Ger., album i nose Enlartung. Albuminous infiltration. [D, 3.] Amyloid d. Lat., morbus amyloides (seu lardaceus, seucereus). Fr.,dardacee, maladie amylo'ide. Ger.,speckige (oder amylo'ide, oder wachsartige) D., Sneckentartung, Amylo'identartung. It., degenerazione lardacea,mal att i a a milo idea. Sp., degeneration a milo idea (6 larddcea). Lardaceous [Portal and Abercrombie] or waxy d. (or disease). A lesion in which the normal textural elements are transformed into, or infiltrated with, a peculiar substance suggesting, on the one hand, an alliance (in some respects only) with the chemical characters of amyloid compounds, and, on the other, with albuminous substances similar to those which pervade the ti ues 9f fostal life. The Royal College of Physicians of London regards it as a substantive disease. Called also bacon-like or lardaceous (by Hodgkin and Bright, albuminous) infiltration; by Budd, scrofulous enlargement (of the liver); by Oppolzer and Schrant, colloid d.; by Meckel, cholesterin disease; by various British writers, waxy d.; and by others hyaloid d. and vitreous d. [D.] Cf. AMYLOID (4th def.). Atheromatous d. Replacement of a ti ue by a material resembling atheroma (2d def.). Bacony d. See Amyloid d. Black d. See ANTHRACOSIS (4th def.) and MELANOSIS. Calcareous d. Fr., degenerescence calcaire. Ger., Verkalkung, Verst eine rung, Verkreidung. It., degenerazione calcure. Sp., degeneration calcdrea. The impregnation of the ti ues and the gland secretions with calcium or magnesium salts, especially carbonates and phosphates. [D.] See CRETIFACTION and CALCIFICATION. Caseous d. See CASSATION. Cellulose d. Fr., degenerescence cellule use. Ger., Cellulosentartung. It., degenerazione cellulosa. Sp., degeneration celulosa. See Amyloid d. Cheesy d. See CASSATION. Cholesterin d. Fr., degenerescence cholesterique. Ger., Cholesterinentartung. It., degenerazione cole steric a. Sp., degeneration cole steric a. Meckel's term for waxy d., on account of the abundance of cholesterin in the waxy'material, and the similarity of the reaction. [D, 3.] Colloid d. Fr., degenerescence collo'ide. Ger., Collo'identartung, colloide D. D. into colloid (3d def.). See also Amyloid d. Cystic d. Fr., degenerescence kystique. Ger., cystische D. The formation of a number of di eminated cysts in an organ or its enlargement in the form of a cyst (as in the kidney). In the chorion it forms the so-called vesicular mole. Cystoid d. of the retina [Nettle ship], Fr., degeneration kysto'ide de la retine. Ger., cysto'ide Entartung der Netzhaut. It., degenerazione cis to idea dell a retina. Sp., degeneration cis to idea de la retina. (Edema of the retina as described by Iwanoff. Similar changes are found in the retina at all ages and at all portions of the retina. Cystoid spaces are found in both granule layers, are round or oval, and are surrounded by hypertrophied radial fibres. [" Roy. Lond. Ophth. Hosp. Rep.," vii, p. 3(F).] Descending secondary d. Fr., degeneration descendente second a ire. Ger., secund are absteigende D. In neuropathology, the destruction and disintegration of nerve-fibres from above downward, i. e., from the central or cerebral extremity of such fibres toward their peripheral extremity. This proce is caused by the presence of some lesion (called primary) which interrupts the continuity of the degenerating fibres and marks the upper limit of the degeneration. The myehn of each fibre first, and the axis cylinder later, become broken up into irregular ma es which are subsequently subdivided into small, fatty, granular globules which ultimately become absorbed. The d. is due to the separation of the fibre from its trophic centre (q. v.) and involves the motor fibres of the encephalon and spinal cord. [Bastian, "Paralysis" (a, 18).] Earthy d. See CRETIFACTION, Calcareous d., and CALCIFICATION. Fascicular d. Fr., degeneration fasciculaire. Ger., Fascicularentartung. It., degenerazione fasci col are. Sp., degeneration fascicular. An atrophic proce in paralyzed muscles due to injury or disease of the motor ganglion-cells of the central tube of gray matter of the spinal cord or of the efferent fibres which connect them with the muscles. [D, 35.] Fatty d. Lat., degeneratio livamotodes. Fr.,degenerescencegrai euse. Ger., Fettentartung, Fettd\ fettige D., Verfettung. It., degenerazione gra osa. Sp., degeneration grasosa. The replacement of normal histological elements by fat. In the muscular fibres of the heart the albuminoid constituents are split up, and within them microscopic particles of fat are deposited. The transverse striae at length disappear, and functional activity is lost in the affected fibres, fa, 25.] Fettd' (Ger.). See Fatty d. Fibro-fatty d. of the placenta [Robin]. Fr., degenerescence fibro-grai euse du placenta, fibro me des villosites et de la serotine [Ercolani]. Ger.,fettig-faserartige D. des Mutter kuchens. It., degenerazione fibro-gra osa del la placenta. Sp., degeneration fibro-grasosa de la placenta. Fatty d. of the placenta a ociated with fibromatous d. of the chorionic villi and of the decidua serotina. [A, 15.] Fibroid d. Fr., degenerescence fibro'ide. Ger., flbro'ide Entartung. A very gradual transformation of ti ue, with scarcely any perceptible exudation of material capable of growth, into a material having a fibre-like appearance. [A, 2.] Fibrous d. of the heart. A connective-ti ue hyperplasia, due to chronic interstitial inflammation. [Hayden (a, 25).] Gelatin i form d. Fr., degeneration gelatin i for me [Cruveilhier]. See Colloid d. Granular d. Fr., degenerescence granulaire. Ger., kornige D. It., degenerazione granulosa. Sp., degeneration granular. Parenchymatous d. or albuminous metamorphosis in which the distinguishing feature is that the granular cloudine seen under the microscope is due to A. apo; AS, at; A>, ah: A, all; Ch, chin: Ch, loch (Scottish); [s. 520]