|Medical Dictionary - Dictionary of Medicine and Human Biology|
Rarely used term for nucleoplasm.
A cell nucleus surrounded by a narrow band of cytoplasm and a plasma membrane. [karyo- + G. plastos, formed]
The achromatic nuclear material that forms the spindle apparatus.
Cytologic characteristics of the superficial or cornified cells of stratified squamous epithelium in which there is shrinkage of the nuclei and condensation of the chromatin into structureless masses. [karyo- + G. pyknos, thick, crowded, + -osis, condition]
Pertaining to or causing karyopyknosis.
Fragmentation of the nucleus whereby its chromatin is distributed irregularly throughout the cytoplasm; a stage of necrosis usually followed by karyolysis. SYN: karyoclasis. [karyo- + G. rhexis, rupture]
A mass of chromatin often found in the interphase cell nucleus representing a more condensed zone of chromatin filaments. SYN: chromatin nucleolus, chromocenter, false nucleolus, net knot. [karyo- + G. soma, body]
SYN: interphase. [karyo- + G. stasis, a standing still]
SYN: nuclear envelope. [karyo- + G. theke, box, sheath]
The chromosome characteristics of an individual cell or of a cell line, usually presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere. SYN: idiogram (1) , karyogram. [karyo- + G. typos, model]
Denoting a parasite inhabiting the cell nucleus of its host. [karyo- + G. zoon, animal]
Haig H., U.S. physician, 1898–1943. See K.-Merritt syndrome.
Morio, Japanese surgeon. See K. operation.
A form of anemia occurring in the Congo River region, with associated edema of subcutaneous tissues, depigmented regions in the skin, and various gastrointestinal disturbances; thought to result from deficiencies in nutrition. SYN: Belgian Congo anemia.
Nikolai I., Russian orthopedist, 1825–1872. See K.-Bek disease.
Frederick H., U.S. histochemist and cell biologist, *1927. See K. fluorescent Schiff reagents, under reagent, K. fluorescent Feulgen stain, K. fluorescent PAS stain.
Abbreviation for katal.
Alternative spelling for cata-; down. [G. kata, down]
katal (kat) (kat′al)
Unit of catalytic activity equal to 1 mol of product formed (or substrate consumed) per second, as of the amount of enzyme that catalyzes transformation of 1 mol of substrate per second.
An alcohol-filled thermometer of specified design that is heated above ambient temperature and then allowed to cool; the time taken to cool between specified temperatures is a measure of the heat content of the environment that takes into account air movement as well as temperature. The bulb may be silvered to minimize radiation effects or blackened to maximize them.
Kunika, Japanese physician, 1856–1931. See K. fever, K. test.
A rare disorder characterized by bone marrow retention of myeloid elements leading to severe peripheral neutropenia; neutrophils have a distinctly abnormal appearance; Gm-CSF levels are undetectable and administration of this substance is therapeutically effective. SYN: myelokathexis.
Sir Bernard, German-British neurophysiologist and Nobel laureate, *1911. See Goldman-Hodgkin-K. equation.
1. SYN: methysticum. 2. SYN: yaqona. [Tongan and Marquesan, Litter]
Tomisaku, 20th century Japanese pediatrician. See K. disease, K. syndrome.
Herbert D., British biochemist, *1893. See Jenner-K. unit.
Bernhard, German physician, 1869–1954. See K.-Fleischer ring.
Varaztad H., Armenian otorhinolaryngologist in the U.S., 1879–1974. See K. operation.
Abbreviation for kilobase.
K blood group, k blood group
See Kell blood group, Blood Groups appendix.
Abbreviation for kilocycle.
Abbreviation for kilogram calorie; kilocalorie.
Thomas P., U.S. ophthalmologist, *1922. See K.-Sayre syndrome.
Walter V., French physician, 1870–1922. See Keating-Hart method.
Paratyphoid or salmonellosis of ducklings.
William W., U.S. surgeon, 1837–1932. See K. operation.
A.H., 20th century U.S. gynecologist. See K. exercises, under exercise.
Hans, German surgeon, 1862–1916. See K. sign.
Sir Arthur, Scottish anatomist, 1866–1955. See K. bundle, K. node, K. and Flack node.
An instrument used, like the harpoon, to remove a specimen of tumor substance for examination. [G. kele, tumor, + ektome, excision]
Kell blood group
See Blood Groups appendix.
William Lordan, U.S. surgeon, 1874–1959. See K. bunionectomy.
George, 18th century Scottish anatomist. See Monro-K. doctrine.
Howard A., U.S. gynecologist, 1858–1943. See K. clamp, K. operation, K. rectal speculum.
Adam B., British otolaryngologist, 1865–1941. See Paterson-K. syndrome, Paterson-Brown-K. syndrome.
A nodular, firm, movable, nonencapsulated, often linear mass of hyperplastic scar tissue, tender and frequently painful, consisting of wide irregularly distributed bands of collagen; occurs in the dermis and adjacent subcutaneous tissue, usually after trauma, surgery, a burn, or severe cutaneous disease such as cystic acne, and is more common in blacks. SYN: cheloid. [G. kele, a tumor (or kelis, a spot), + eidos, appearance] acne k. a chronic eruption of fibrous papules that develop at the site of deep folliculitis, usually on the back of the neck at the hairline. SYN: folliculitis keloidalis.
Lord William Thomson, Scottish physicist, 1824–1907. See k., K. scale.
A unit of thermodynamic temperature equal to 273.16−1 of the thermodynamic temperature of the triple point of water. See K. scale. [Lord K.]
J., 20th century U.S. pathologist. See Abell-K. method.
See Abell-K. method.
Edward, U.S. dentist, *1883. See K. classification.
Robert Foster, U.S. neurologist, 1884–1952. See K. syndrome, Foster K. syndrome.
William, U.S. neurologist. See K. disease.
Elizabeth, Australian nurse, 1880–1952. See K. treatment.
See ceno- (3) . [G. kenos, empty]
Albert F.S., English physiologist, 1863–1958. See K. bundle, K.-His bundle.
Jean F., French physician, 1873–1934. See K. sign.
Obsolete term for glucocerebroside. SYN: cerasin.
keratan sulfate (ker′a-tan)
A type of sulfated mucopolysaccharide containing d-galactose in place of the uronic acid of hyaluronic acid or chondroitin; also containing unsulfated and 6-sulfated N-acetyl-d-glucosamine; found in cartilage, bone, connective tissue, the cornea, aorta, and in the intervertebral disks; accumulates in Morquio syndrome; k. I is abundant in cornea and is attached to a protein via an asparaginyl residue; k. II is found in loose connective tissue and bone and is linked to a seryl or threonyl residue. SYN: keratosulfate.
SYN: keratoectasia. [kerato- + G. ektasis, extrusion]
An operation done to change the refraction of the cornea; a crescentic piece of corneal stroma is removed and the resultant corneal wound is sutured. This steepens the cornea and increases its power in that axis. SEE ALSO: keratotomy. [kerato- + G. ektome, excision] automated lamellar k. resection of a disk of corneal tissue using a precise machine to alter the refractive power of the eye. photorefractive k. (PRK) removal of part of the cornea with a laser to change its shape, and thus to modify the refractive error of the eye (reduce its myopia, for example). phototherapeutic k. (PTK) ablation of diseased corneal tissue using an excimer laser.
The easily digested reduction product of keratin, in which the disulfide links are reduced to SH groups, the individual peptide chains being separated.
Collective name for a group of proteins that form the intermediate filaments in epithelial cells. Keratins have a molecular weight between 40 kd and 68 kd, and are separated one from another by electrophoresis and isoelectric focusing; thus separated, they are sequentially numbered from 1–20, and also subdivided into low, intermediate, and high molecular weight proteins. According to their isoelectric mobility they are either acidic or basic. In general, each acidic k. protein has its basic equivalent with which it is paired to form the intermediate filaments; some k. proteins, however, occur unpaired. Various epithelial cells contain different k. proteins, in a tissue-specific manner. Antibodies to k. proteins are widely used for histologic typing of tumors, and are especially useful for distinguishing carcinomas from sarcomas, lymphomas, and melanomas. SYN: ceratin, cytokeratin. [G. keras (kerat-), horn, + -in]
Hydrolases catalyzing the hydrolysis of keratin; each having slightly different specificities.
Keratin formation or development of a horny layer; may also apply to premature formation of keratin. SYN: cornification.
Having become horny. SYN: cornified.
A cell of the living epidermis and certain oral epithelium that produces keratin in the process of differentiating into the dead and fully keratinized cells of the stratum corneum.
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