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Medical Dictionary


kernicterus (ker-nik′ter-us)
Jaundice associated with high levels of unconjugated bilirubin, or in small premature infants with more modest degrees of bilirubinemia; yellow staining and degenerative lesions are found chiefly in basal ganglia including in the lenticular nucleus, subthalamus, Ammon horn, and other areas; may occur with hemolytic disorder such as Rh or ABO erythroblastosis or G6PD deficiency as well as with neonatal sepsis or Crigler-Najjar syndrome; characterized early clinically by opisthotonus, high-pitched cry, lethargy, and poor sucking, as well as abnormal or absent Moro reflex, and loss of upward gaze; later consequences include deafness, cerebral palsy, other sensineural deficits, and mental retardation. SYN: bilirubin encephalopathy, nuclear jaundice. [Ger. Kern, kernel (nucleus), + Ikterus, jaundice]

Vladimir, Russian physician, 1840–1917. See K. sign.

James W., U.S. pathologist, 1896–1981. See K. notch.

kerosene (ker′o-sen)
A mixture of petroleum hydrocarbons, chiefly of the methane series; the fifth fraction in the distillation of petroleum, used as fuel for lamps and stoves, as a degreaser and cleaner, and in insecticides. Contact on human skin can lead to irritation and infection; inhalation may cause headache, drowsiness, coma; swallowing causes irritation, vomiting, and diarrhea. Vomiting should not be induced, as aspiration of vomitus causes pneumonitis. [G. keros, wax, + -ene]

Harry Hyland, U.S. surgeon, 1881–1963. See Parker-K. suture.

Alfred, U.S. ophthalmologist, 1890–1961. See K. sign, K. number, K. procedure.

ketal (ke′tal)
RC(OR′)(R&dprime;)OR‴;a hydrated ketone in which both hydroxyl groups are esterified with alcohols.

ketamine (ket′a-men)
A parenterally administered anesthetic that produces catatonia, profound analgesia, increased sympathetic activity, and little relaxation of skeletal muscles; side effects include sialorrhea and occasional pronounced dysphoria, especially in adults; chemically related to phencyclidine (PCP), it can produce hallucinations.

ketanserin (ket-an′ser-in)
Specific serotonin 5HT2-receptor antagonist with antihypertensive properties; the drug also reduces platelet aggregation produced by serotonin.

ketene (ke′ten)
1. CH2&dbond;C&dbond;O;a very reactive acetylating agent, used in chemical syntheses. 2. Any substituted k..

ketimine (ke′ta-men)
R&cbond;N&dbond;C(R′)(R′′);a tautomer of an aldimine, formed in many enzyme-catalyze reactions; e.g., aminotransferases.

Combining form denoting a compound containing a ketone group; replaced by oxo- in systematic nomenclature. [Ger.]

keto acid (ke′to)
An acid containing a ketone group (–CO–) in addition to the acid group(s); α-k. refers to a 2-oxo acid ( e.g., pyruvic acid); β-k. refers to a 3-oxo acid ( e.g., acetoacetic acid), etc. SYN: oxo acid. α-k. dehydrogenase one of several distinct multienzyme complexes that catalyzes the formation of an acyl-CoA derivative, CO2, and NADH from an α-k., NAD+, and coenzyme A; maple syrup urine disease results from several different inherited defects in the mitochondrial branched chain α-k. dehydrogenase complex.

3-ketoacid-CoA transferase
SYN: 3-oxoacid-CoA transferase.

ketoacidemia (ke′to-as-id-e′me-a)
SYN: maple syrup urine disease.

ketoacidosis (ke′to-as-i-do′sis)
Acidosis, as in diabetes or starvation, caused by the enhanced production of ketone bodies.

ketoaciduria (ke′to-as-i-doo′re-a)
Excretion of urine having an elevated content of keto acids. branched chain k. SYN: maple syrup urine disease.

3-ketoacyl-CoA thiolase
SYN: acetyl-CoA acyltransferase.

2-ketoadipic acid (ke′to-a-dip′ik)
An intermediate in l-tryptophan and l-lysine catabolism; k. accumulates in certain inherited disorders, probably due to a deficiency of one of the proteins in the α-ketoadipate dehydrogenase complex; 2-oxoadipic acid; 2-oxohexadioic acid. 2-ketoadipic acid dehydrogenase complex the multienzyme complex that reacts k. with coenzyme A and NAD+ to produce glutaryl-CoA, CO2, and NADH + H+ in l-lysine and l-tryptophan catabolism; a deficiency of one of the proteins in this complex results in 2-ketoadipic acidemia.

2-ketoadipic acidemia (ke′to-a-dip′ik)
Elevated levels of 2-ketoadipic acid in the serum.

ketoconazole (ke-to-ko′na-zol)
A broad spectrum antifungal agent used to treat systemic and topical fungal infections.

ketogenesis (ke-to-jen′e-sis)
Metabolic production of ketones or ketone bodies.

ketogenic (ke-to-jen′ik)
Giving rise to ketone bodies in metabolism.

ketoheptose (ke-to-hep′tos)
A seven-carbon sugar possessing a ketone group. SYN: heptulose.

ketohexose (ke-to-heks′os)
A six-carbon sugar possessing a ketone group; e.g., fructose. SYN: hexulose.

ketohydroxyestrin (ke′to-hi-drok-se-es′trin)
SYN: estrone.

ketol (ke′tol)
A ketone that has an OH group near the CO group. In an α-k., the OH is attached to a carbon atom that is attached to the CO carbon atom; in a β-k., one carbon atom intervenes.

ketole (ke′tol)
SYN: indole (1) .

ketole group
Carbons 1 and 2 of a 2-ketose (HOCH2CO&cbond;); trans-ketolation from d-xylose 5-phosphate to C-1 of aldoses is important in various metabolic pathways involving carbohydrates ( e.g., photosynthesis, Dickens shunt); the two-carbon unit is transferred as α,β-dihydroxyethylthiamin pyrophosphate.

ketolytic (ke-to-lit′ik)
Causing the dissolution of ketone or acetone substances, referring usually to oxidation products of glucose and allied substances.

ketone (ke′ton)
A substance with the carbonyl group linking two carbon atoms; the most important in medicine and the simplest k. is dimethyl k. (acetone).

ketone alcohol
A compound containing a carbonyl or ketone group as well as a hydroxyl group; e.g., dihydroxyacetone.

ketone-aldehyde mutase
SYN: lactoylglutathione lyase.

ketonemia (ke-to-ne′me-a)
The presence of recognizable concentrations of ketone bodies in the plasma. [ketone + G. haima, blood]

ketonic (ke-ton′ik)
Pertaining to, or possessing the characteristics of, a ketone.

ketonization (ke-to-ni-za′shun)
Conversion into a ketone.

ketonuria (ke-to-noo′re-a)
Enhanced urinary excretion of ketone bodies. branched chain k. SYN: maple syrup urine disease.

ketopantoic acid (ke′to-pan-to′ik)
Oxidized precursor of pantoic acid, intermediate on the synthetic pathway between α-ketoisovaleric acid and pantothenic acid.

ketopentose (ke-to-pen′tos)
A five-carbon sugar in which carbons 2, 3, or 4 make up part of a carbonyl group; e.g., ribulose.

A pyrrolo-pyrrole nonsteroidal antiinflammatory agent with antipyretic and analgesic properties; similar in actions to ibuprofen but substantially more potent and capable of relieving severe pain. Often used by injection.

ketose (ke′tos)
A carbohydrate containing the characteristic carbonyl group of the ketones; i.e., a polyhydroxyketone; e.g., fructose, ribulose, sedoheptulose; the majority of the naturally occurring ketoses have the carbonyl group on the second carbon.

ketose-1-phosphate aldolase
Fructose bisphosphate aldolase.

ketose reductase
SYN: d-sorbitol-6-phosphate dehydrogenase.

ketosis (ke-to′sis)
A condition characterized by the enhanced production of ketone bodies, as in diabetes mellitus or starvation. [ketone + -osis, condition] bovine k. a common metabolic disease of cows which appears as a rule within a few weeks after parturition; characterized by hypoglycemia, ketonuria, loss of appetite, lethargy, loss of milk production, and rapid emaciation.

17-ketosteroids (17-KS) (ke-to-ster′oydz)
Nominally, any steroid with a carbonyl group on C-17; commonly used to designate urinary C19 steroidal metabolites of androgenic and adrenocortical hormones that possess this structural feature. SYN: 17-oxosteroids.

ketosuccinic acid (ke-to-suk′si-nik)
SYN: oxaloacetic acid.

ketosuria (ke′to-su′re-a′)
The presence of ketones in the urine.

ketotetrose (ke′to-tet′ros)
A four-carbon sugar possessing a ketone group; E.G., erythrulose.

ketotic (ke′tot-ik)
Pertaining to ketone bodies; presence of acidosis due to excess ketone body production such as occurs in uncontrolled insulin-dependent diabetes.

ketotriose (ke′to-tri′os)
A three-carbon sugar possessing a ketone group; I.E., dihydroxyacetone.

Abbreviation for kiloelectron volts, a unit of energy in diagnostic radiography and nuclear medicine, equivalent to the kinetic energy gained by an electron falling through a potential of 1 volt.

Charles Alston, English physician, 1793–1849.

Ernst A.H., Swedish anatomist and physician, 1832–1901. See foramen of K.-Retzius, sheath of K. and Retzius.

keyway (ke′wa)
The female portion of a precision attachment.

Abbreviation for kilogram.

khat (kot)
The tender fresh parts of Catha edulis.

khellin (kel′in)
The active principle in extracts of Ammi visnaga, an umbelliferous plant growing in the Near East; used in angina pectoris and asthma. [Ar. khella]

Abbreviation for Knoop hardness number.

kick (kik)
A brisk mechanical stimulus. atrial k. the priming force contributed by atrial contraction immediately before ventricular systole to increase the efficiency of ventricular ejection due to acutely increased preload. idioventricular k. the increased contractility of the initially contracting ventricular fibers which, by stretching the later contracting fibers, increases their force of contraction.

Kidd blood group
See Blood Groups appendix.

kidney (kid′ne)
One of the paired organs that excrete urine. The kidneys are bean-shaped organs (about 11 cm long, 5 cm wide, and 3 cm thick) lying on either side of the vertebral column, posterior to the peritoneum, about opposite the twelfth thoracic and first three lumbar vertebrae. SYN: nephros, ren. [A.S. cwith, womb, belly, + neere, k. (L. ren, G. nephros)] amyloid k. a k. in which amyloidosis has occurred, usually in association with some chronic illness such as multiple myeloma, tuberculosis, osteomyelitis, or other chronic suppurative inflammation; such kidneys are moderately enlarged and grossly manifest a waxy appearance, with amyloid deposited beneath the endothelium in the glomerular loops and in the arterioles, apparently beginning as foci of thickening of the basement membranes. SYN: waxy k.. Armanni-Ebstein k. glycogen vacuolization of the loops of Henle, seen in diabetics before the introduction of insulin. SYN: Armanni-Ebstein change. arteriolosclerotic k. a k. in which there is sclerosis of the arterioles, i.e., arteriolar nephrosclerosis resulting from long-standing benign hypertension. Such kidneys tend to be pale red-brown or relatively gray, moderately reduced in size, and firmer than normal organs; the capsular surfaces are uniformly finely granular. Most of the arterioles are thickened and hyalinized, thereby resulting in varying degrees of narrowing of the lumens, ischemia, and fibrosis in the interstitial tissue, leading to uniform contraction of the cortex. arteriosclerotic k. a k. in which there is sclerosis of arterial vessels larger than arterioles. Such kidneys are usually not significantly reduced in size, but are likely to be paler than usual; the capsular surface may be marked by a few, possibly several, conical, relatively deep V-shaped scars that result from fibrosis and ischemic atrophy of the region supplied by the affected vessel. artificial k. SYN: hemodialyzer. Ask-Upmark k. true renal hypoplasia with decreased lobules and deep transverse grooving of the cortical surfaces of the k.. atrophic k. a k. that is diminished in size because of inadequate circulation and/or loss of nephrons. cake k. a solid, irregularly lobed organ of bizarre shape, usually situated in the pelvis toward the midline, produced by fusion of the renal anlagen. contracted k. a diffusely scarred k. in which the relatively large amount of abnormal fibrous tissue and ischemic atrophy leads to a moderate or great reduction in the size of the organ, as in arteriolar nephrosclerosis and chronic glomerulonephritis. cow k. a k. containing an abnormally large number of minor calices, resembling normal bovine renal anatomy. crush k. acute oliguric renal failure following crushing injuries of muscle; kidneys show the changes of hypoxic tubular damage, plus pigment casts in renal tubules that contain myoglobin. cystic k. a general term used to indicate a k. that contains one or more cysts, including polycystic disease, solitary cyst, multiple simple cysts, and retention cysts (associated with parenchymal scarring). disk k. SYN: pancake k.. duplex k. a k. in which two pelviocaliceal systems are present. fatty k. a k. in which there is fatty metamorphosis of the parenchymal cells, especially fatty degeneration. flea-bitten k. the k. seen at autopsy in some cases of bacterial endocarditis, the appearance being caused by diffuse petechial hemorrhages resulting from focal glomerulonephritis. floating k. the abnormally mobile k. that frequently descends to the brim of the pelvis when the patient assumes the erect position; nephroptosis. SYN: movable k., wandering k.. Formad k. an enlarged and deformed k. sometimes seen in chronic alcoholism. fused k. a single, anomalous organ produced by fusion of the renal anlagen. Goldblatt k. a k. whose arterial blood supply has been compromised, as a consequence of which arterial (renovascular) hypertension develops. granular k. a k. in which fairly uniform, diffusely and evenly situated foci of scarring of the interstitial tissue of the cortex (and sometimes scarring of glomeruli), and the associated slight degree of bulging of groups of dilated tubules, leads to the development of a minutely bosselated surface; such kidneys are seen in arteriolar nephrosclerosis or chronic glomerulonephritis. SYN: sclerotic k.. head k. SYN: pronephros (1) . hind k. SYN: metanephros. horseshoe k. union of the lower or occasionally the upper extremities of the two kidneys by a band of tissue extending across the vertebral column. medullary sponge k. cystic disease of the renal pyramids associated with calculus formation and hematuria; differs from cystic disease of the renal medulla in that renal failure does not usually develop. middle k. SYN: mesonephros. mortar k. SYN: putty k.. movable k. SYN: floating k.. pancake k. a disk-shaped organ produced by fusion of both poles of the contralateral k. anlagen. SYN: disk k.. pelvic k. a congenital abnormality in which the k. is in the pelvis; usually the arterial blood supply comes off the bifurcation of the aorta or the iliac artery. polycystic k. a progressive disease characterized by formation of multiple cysts of varying size scattered diffusely throughout both kidneys, resulting in compression and destruction of renal parenchyma, usually with hypertension, gross hematuria, and uremia leading to progressive renal failure. There are two major types: 1) with onset in infancy or early childhood, usually of autosomal recessive inheritance [MIM*263200]; 2) with onset in adulthood, of autosomal dominant inheritance with genetic heterogeneity [MIM*173900, 173910, and 600666]; may be caused by mutation in either polycystin-1 gene on chromosome 16p, polycystin-2 gene on 4q, or gene(s) not identified yet. SYN: polycystic disease of kidneys. primordial k. SYN: pronephros. putty k. a k. containing caseous material trapped by stricture of the ureter due to tuberculous granulations in renal tuberculosis. SYN: mortar k.. pyelonephritic k. a k. deformed by multiple scars as a result of chronic or recurrent renal infection. Rose-Bradford k. a form of fibrotic k. of inflammatory origin found in young persons. sclerotic k. SYN: granular k.. sigmoid k. upper pole of one k. fused with the lower pole of the other. supernumerary k. a k., in addition to the two usually present, developed from the splitting of the nephrogenic blastema or from a separate metanephric blastema, into which a partial or complete duplication of the ureteral stalk enters to form a separate, capsulated k.; in some cases, the separation of the duplicated organ is incomplete. thoracic k. ectopic k. that partially lies above the diaphragm in the posterior mediastinum. wandering k. SYN: floating k.. waxy k. SYN: amyloid k..

Kiel classification
See under classification.

See Kjelland.

Alphonse M.J., 19th century German physician. See Kussmaul-K. respiration.

Robert, Austrian roentgenologist, 1871–1953. See K. disease, K. dislocation, K. unit.

Francis, English physician, 1800–1874. See K. space.

Wilhelm, German laryngologist, 1839–1902. See K. area.

M, 20th century Japanese hematologist. See K. disease.

Hermann F., German gynecologist, 1800–1863. See K. line.

H., chemist, 1855–1945. See K.-Fischer synthesis, K.-Fischer reaction.

Gustav J., German laryngologist, 1860–1921. See K. bundle, K. operation, K. triangle.

kilo- (k)
Prefix used in the SI and metric system to signify one thousand (103). [G. chilioi, one thousand]

kilobase (kb) (kil′o-bas)
Unit used in designating the length of a nucleic acid sequence; 1 kb equals a sequence of 1000 purine or pyrimidine bases.


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