Medical Dictionary

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Citrobacter (sit′ro-bak-ter)
A genus of motile bacteria (family Enterobacteriaceae) containing Gram-negative rods which use citrate as a source of carbon; the motile cells are peritrichous. Fermentation of lactose by these organisms is delayed or absent; they produce trimethylene glycol from glycerol. The type species is C. freundii. C. amalonatica a bacterial species found in feces, soil, water, and sewage; isolated from clinical specimens as an opportunistic pathogen. SYN: Levinea amalonatica. C. diversus a bacterial species found in feces, soil, water, sewage, and food; isolated from urine, throat, nose, sputum, and wounds; reported in cases of neonatal meningitis where it frequently is severe, resulting in brain abscess formation. SYN: C. koseri, Levinea diversus, Levinea malonatica. C. freundii a bacterial species found in water, feces, and urine; it is an inhabitant of the normal intestine, but it may occur in alimentary infections and in infections of the urinary tract, gallbladder, middle ear, and meninges; it is the type species of the genus C.. C. koseri SYN: C. diversus.

citronella (sit-ro-nel′a)
Cymbopogon (Andropogon) nardus (family Gramineae); a fragrant grass of Ceylon, from which is distilled a volatile oil (c. oil) used as a perfume and insect repellent.

citronellal (sit′-ro-nel′al)
Principal volatile ingredient of lemon grass and citronella oil. Used in soap perfumes and as an insect repellent.

citrulline (sit′rul-en)
N5-(Aminocarbonyl)-l-ornithine; α-amino-δ-ureidovaleric; 5-ureidonorvaline;an amino acid formed from l-ornithine in the course of the urea cycle as well as a product in nitric oxide biosynthesis; also found in watermelon (Citrullus vulgaris) and in casein. Elevated in individuals with a deficiency of argininosuccinate synthetase or argininosuccinate lyase.

citrullinemia (sit′rul-i-ne′me-a) [MIM*215700]
Urea cycle disorder in which citrulline concentrations in the blood, urine, and cerebrospinal fluid are elevated, because of deficiency of arginosuccinate synthetase (ASS); manifested clinically by lethargy, vomiting, ammonia intoxication, and mental retardation with onset usually in infancy; autosomal recessive inheritance, caused by mutation in the ASS gene on chromosome 9 in some patients.

citrullinuria (sit′rul-i-noo′re-a)
Enhanced urinary excretion of citrulline; a manifestation of citrullinemia.

Civatte
Achille, French dermatologist, 1877-1956. See C. bodies, under body, poikiloderma of C..

Civinini
Filippo, Italian anatomist, 1805–1844. See C. canal, C. ligament, C. process.

CJD
Abbreviation for Creutzfeldt-Jakob disease.

CK
Abbreviation for creatine kinase.

Cl
Symbol for chlorine.

cladiosis (klad-e-o′sis)
A dermatophytosis resembling sporotrichosis, characterized by verrucous lesions and ascending lymphangitis; caused by Scopulariopsis blochii. See Scopulariopsis. [G. klados, branch or root, + -osis, condition]

Clado
Spiro, French gynecologist, 1856–1905. See C. anastomosis, C. band, C. ligament, C. point.

Cladorchis watsoni (kla-dor′kis wat-so′ni)
Incorrect term for Watsonius watsoni.

cladosporiosis (klad′o-spo-re-o′sis)
Infection with a fungus of the genus Cladosporium. cerebral c. cerebral phaeohyphomycosis, a mycotic brain infection usually due to Cladosporium trichoides (Xylohypha bantianum).

Cladosporium (klad-o-spor′i-um)
A genus of fungi having dematiaceous or dark-colored conidiophores with oval or round spores, commonly isolated in soil or plant residues. [G. klados, a branch, + sporos, seed] C. carrionii a species of fungi that is a cause of chromoblastomycosis in humans. C. cladosporioides a species reported to cause local infection at the site of a skin test in an HIV-infected patient. C. werneckii SYN: Exophiala werneckii. C. (Xylohypha) bantianum a species of fungi that causes cerebral cladosporiosis; probably synonymous with C. trichoides.

clairvoyance (klar-voy′ans)
Perception of objective events (past, present, or future) not ordinarily discernible by the senses; a type of extrasensory perception. [Fr.]

clamoxyquin hydrochloride (klam-ok′si-kwin)
An amebicide.

clamp (klamp)
An instrument for compression or holding a structure. Cf.:forceps. [M.E., fr. Middle Dutch klampe] Cope c. a c. used in excision of colon and rectum. Crafoord c. a c. used in heart, lung, and vascular operations. Crile c. a c. for temporary stoppage of blood flow. Fogarty c. a c. with rubber-shod blades having serrated surfaces, to provide an atraumatic grip on tissues. Gant c. a right-angled c. used in hemorrhoidectomy. Gaskell c. an instrument for crushing the atrioventricular bundle in experimental animals and thus producing heart block. gingival c. a springlike metal piece encircling or grasping the cervix of a tooth and shaped so as to retract the gingival tissue. Kelly c. a curved hemostat without teeth, introduced for gynecological surgery. Kocher c. a heavy, straight hemostat with interlocking teeth on the tip. liver-shod c. a c. with jaws covered by cloth to minimize injury to structures such as bowel when c. is closed. Mikulicz c. a c. used to crush walls between proximal and distal colon in two-stage colectomy. Mixter c. a right angle c.. Mogen c. a circumcision instrument. [Hebrew star] mosquito c. a small hemostat, straight or curved, with or without teeth; used to hold delicate tissue or for hemostasis. SYN: mosquito forceps. Ochsner c. a straight hemostat with teeth. patch c. SYN: patch clamping. Payr c. a large, slightly curved c. used in gastrectomy or enterectomy. Potts c. a fine-toothed, multiple-point, vascular fixation c. that imparts limited trauma to the vessel while securely holding it. Rankin c. a three-bladed c. used in resection of colon. right angle c. a c. with a short 90° bend to its tip frequently used for dissection or passage of ligatures around vessels. rubber dam c. a springlike metal piece encircling or grasping the cervix of a tooth and so shaped as to prevent a rubber dam from coming off the tooth. rubber-shod c. a small rubber-tipped c. that holds sutures in place during surgery.

clamp connection
In fungi, a short hypha which bypasses a hyphal septum and is attached to the two cells adjacent to the septum; characteristic of most members of the phylum Basidiomycetes.

clapotage, clapotement (kla-po-tahz′, kla-pot-mawn′)
The splashing sound heard on succussion of a dilated stomach. [Fr.]

Clapton
Edward, English physician, 1830–1909. See C. line.

Clara
Max, Austrian anatomist, 1899–1966. See C. cell.

clarificant (kla-rif′i-kant)
An agent that makes a turbid liquid clear. [L. clarus, clear, + facio, to make]

clarification (klar′i-fi-ka′shun)
The process of making a turbid liquid clear. SYN: lucidification.

Clark
Leland, Jr., U.S. biochemist, *1918. See C. electrode.

Clark
Eliot R., U.S. anatomist, 1881–1963. See Sandison-C. chamber.

Clark
Alonzo, U.S pharmacologist, 1807–1887. See C. weight rule.

Clark
Wallace H., Jr., U.S. dermatopathologist, *1924. See C. level.

Clarke
Jacob A.L., English anatomist, 1817–1880. See C. column, C. nucleus.

Clarke
Cecil. See C.-Hadfield syndrome.

clasmatocyte (klaz-mat′o-sit)
Obsolete term for macrophage. [G. klasma, a fragment, + kytos, a hollow (cell)]

clasmatosis (klaz-ma-to′sis)
The extension of pseudopodia-like processes in unicellular organisms and blood cells by plasmolysis rather than by a true formation of pseudopodia. [G. klasma, a fragment, + -osis, condition]

clasp
1. A part of a removable partial denture that acts as a direct retainer and/or stabilizer for the denture by partially surrounding or contacting an abutment tooth. 2. A direct retainer of a removable partial denture, usually consisting of two arms joined by a body which connects with an occlusal rest; at least one arm of a c. usually terminates in the infrabulge (gingival convergence) area of the tooth enclosed. bar c. 1. a c. whose arms are bar-type extensions from major connectors or from within the denture base; the arms pass adjacent to the soft tissues and approach the point of contact on the tooth in a gingivo-occlusal direction; 2. a c. consisting of two or more separate arms located opposite to each other on the tooth; the bar arms arise from the framework or from a connector and may traverse the soft tissue; one arm (bar), the retentive arm, usually terminates in the infrabulge (gingival convergence) area of the tooth; the other, the reciprocal arm, usually terminates on the suprabulge (occlusal convergence) area. SYN: Roach c.. circumferential c. 1. a c. that encircles more than 180° of a tooth, including opposite angles, and which usually contacts the tooth throughout the extent of the c., at least one terminal being in the infrabulge (gingival convergence) area; 2. a c. consisting of two circumferential c. arms, both of which originate from the same minor connector and are located on opposite surfaces of the abutment tooth. continuous c. SYN: continuous bar retainer. extended c. a c. that extends from its minor connector along the lingual and/or facial surface of two or more teeth. Roach c. SYN: bar c..

class (klas)
In biologic classification, the next division below the phylum (or subphylum) and above the order. [L. classis, a c., division]

classification (klas′i-fi-ka′shun)
A systematic arrangement into classes or groups based on perceived common characteristics; a means of giving order to a group of disconnected facts. adansonian c. the c. of organisms based on giving equal weight to every character of the organism; this principle has its greatest application in numerical taxonomy. [M. Adanson] Angle c. of malocclusion a c. of different types of malocclusion, based on the mesiodistal relationship of the permanent molars upon their eruption and locking, and comprised of three classes; Class I: normal relationship of the jaws, wherein the mesiobuccal cusp of the maxillary first molar occludes in the buccal groove of the mandibular first permanent molar; Class II: distal relationship of the mandible, wherein the distobuccal cusp of the maxillary first permanent molar occludes in the buccal groove of the mandibular first molar, and further classified as Division 1, labioversion of maxillary incisor teeth, and Division 2, linguoversion of maxillary central incisors, both of which may be unilateral conditions; Class III: mesial relationship of the mandible, wherein the mesiobuccal cusp of the maxillary first molar occludes in the embrasure between the mandibular first and second permanent molars, further classified as a unilateral condition. Arneth c. a c. of the polymorphonuclear neutrophils according to the number of their nuclear lobes. See Arneth stages, under stage. Astler-Coller c. a staging system that is a modification of Dukes c. for colon cancer. Bethesda c. SYN: Bethesda system. Black c. a c. of cavities of the teeth based upon the tooth surface(s) involved. Caldwell-Moloy c. a c. of the variations in the female pelvis; namely gynecoid, android, anthropoid, and platypelloid pelvis, based on the type of the posterior and anterior segments of the inlet. Cummer c. a listing of several types of removable partial dentures in accordance with the distribution of direct retainers. DeBakey c. consists of three types: Type I extends into the transverse arch and distal aorta and type II is confined to the ascending aorta; type III dissections begin in the descending aorta, with type IIIA extending toward the diaphragm and type IIIB extending below it. Denver c. a system of nomenclature for human mitotic chromosomes, based on length and position of the centromere. [Denver, Colorado, where agreed upon] Dukes c. a c. of the extent of invasion of a resected adenocarcinoma of the colon or rectum commonly modified as follows: A (Dukes A), confined to the mucosa; B1, into the muscularis mucosae; B2, through the muscularis mucosae; C1, limited to the bowel wall, with nodal metastases; C2, through the bowel wall, with nodal metastases. FAB c. French-American-British c. of acute leukemias based on the study of microscopic features and cytochemistry of blast cells; it subdivides acute myelogenous leukemias into 8 groups (M0–M7) and acute lymphoblastic leukemias into 3 groups (L1–L3); widely used in clinical practice. SYN: French-American-British c.. French-American-British c. SYN: FAB c.. Gell and Coombs C. (gel koomz) a c. system that differentiates the 4 types of hypersensitivity reactions: Type I: anaphylactic reactions, Type II: cytotoxic reactions, Type III: immune complex reactions, and Type IV: cell-mediated/delayed hypersensitivity reactions. International Labour Organization C. ILO 1980 International C. of Radiographs of the Pneumoconioses; a system for qualitative and semiquantitative description of the chest radiographic findings caused by pneumoconiosis, designed for epidemiologic studies; supersedes classifications of 1950, 1958, 1968, and 1971. Jansky c. the c. of human blood groups now designated O, A, B, and AB. Kennedy c. a listing of several forms of partially edentulous jaws in accordance with the distribution of the missing teeth. Kiel c. c. of non-Hodgkin lymphoma into low-grade malignancy (lymphocytic, lymphoplasmacytoid, centrocytic, and centroblastic-centrocytic types) and high-grade malignancy (centroblastic, lymphoblastic of Burkitt or convoluted cell, and immunoblastic types). SYN: Lennert c.. Lancefield c. a serologic c. dividing hemolytic streptococci into groups (A to O) which bear a definite relationship to their sources, based upon precipitation tests depending upon group-specific substances that are carbohydrate in nature; e.g., Group A contains strains most pathogenic for humans; B, strains from mastitis in cows and from normal milk, including strains from the human throat and vagina; C, strains from various lower animals, including a number from cattle and the human throat; D, strains from cheese and humans; E, strains from certified milk; F, strains mainly from the human throat, associated with tonsillitis; G, strains from humans, a few from monkeys and dogs; and H, K, and O, nonpathogenic strains occasionally from normal human respiratory tracts. Lennert c. SYN: Kiel c.. Lukes-Collins c. a c. of lymphomas according to the immunologic nature of the cell of origin, based on histologic and clinical data. multiaxial c. a procedure used in DSM-III-R for diagnosing patients on five axes: 1) psychiatric syndrome present; 2) patient's history of personality and developmental disorders; 3) possible nonmental medical disorders; 4) severity of psychosocial stressors; 5) highest level of adaptive functioning in the past year. New York Heart Association c. a functional c. to assess cardiovascular disability. Class I: patients with cardiac disease without limitation of physical activity. Ordinary activity does not cause symptoms. Class II: patients with cardiac disease with slight limitation of activity; comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnea or angina. Class III: patients with cardiac disease producing marked limitation of activity: comfortable at rest. Less than ordinary physical activity causes symptoms. Class IV: patients with cardiac disease resulting in inability to carry on any physical activity without discomfort. Symptoms may be present even at rest. Rappaport c. a histologic c. of lymphomas in use before the availability of recent methods for identification of B- and T-type lymphocytes. REAL c. a c. of lymphoma first published in 1994 and based on the correlation of clinical features of lymphomas with their histopathology and immunophenotype and genotype of neoplastic cells; groups lymphoproliferative diseases into chronic leukemia/lymphoma, nodal or extranodal lymphoma, acute leukemia lymphoma, plasma cell disorders, and Hodgkin disease. [Revised European-American llymphoma c.] Runyon c. a c. scheme for mycobacteria other than Mycobacterium tuberculosis that divides species into four categories: 1) photochromogens, species that produce a yellow to brown carotene pigment when grown in the presence of light; 2) scotochromogens, which produce pigment in presence or absence of light; 3) nonpigmented, which do not produce pigment; and 4) rapid growers, which grow on solid media in 5–10 days rather than 4–8 weeks. This c. has no clinical or genetic significance but remains of limited value in identification of some clinical isolates. Rye c. c. of Hodgkin disease according to lymphocyte predominance, nodular sclerosing, mixed cellularity, and lymphocyte depletion types. [Rye, NY, 1965] Salter-Harris c. of epiphysial plate injuries the c. of epiphysial plate injuries into five groups (I to V), according to the pattern of damage to epiphysis, physis, and/or metaphysis; the c. correlates with different prognoses regarding the effects of the injury on subsequent growth and subsequent deformity of the epiphysis. Tessier c. an anatomical c. of facial, craniofacial, and laterofacial clefts that utilizes the orbit as the primary structure for reference. Fifteen locations for clefts are differentiated.

class switch
Change in the isotype of antibody produced after a B cell has encountered an antigen.

clastic (klas′tik)
Breaking up into pieces, or exhibiting a tendency so to break or divide. [G. klastos, broken]

clastogen (klas′to-jen)
An agent ( e.g., certain chemicals, x-rays, ultraviolet light) that causes breaks in chromosomes. [G. klastos, broken, + genos, birth]

clastogenic (klas-to-jen′ik)
Relating to the action of a clastogen.

clathrate (klath′rat)
A type of inclusion compound in which small molecules are trapped in the cagelike lattice of macromolecules. [L. clathrare, pp. -atus, to furnish with a lattice]

clathrin (klath′rin)
The principal constituent of a polyhedral protein lattice that coats eukaryotic cell membranes (vesicles) and coated pits and appears to be involved in protein secretion. This protein also occurs in synaptic vesicles. [L. clathri, lattice]

Clauberg
Karl W., German bacteriologist, *1893. See C. test, C. unit.

Claude
Henri, French psychiatrist, 1869–1945. See C. syndrome.

claudication (klaw-di-ka′shun)
Limping, usually referring to intermittent c.. [L. claudicatio, fr. claudico, to limp] intermittent c. a condition caused by ischemia of the muscles; characterized by attacks of lameness and pain, brought on by walking, chiefly in the calf muscles; however, the condition may occur in other muscle groups. SYN: Charcot syndrome, myasthenia angiosclerotica. neurogenic c. c. with neurologic injury, usually in association with lumbar spinal stenosis.

claudicatory (klaw′di-ka-tor-e)
Relating to claudication, especially intermittent claudication.

Claudius
Friedrich M., German anatomist, 1822–1869. See C. cells, under cell, C. fossa.

Clausen
J., Danish physician. See Dyggve-Melchior-C. syndrome.

claustra (klaws′tra)
Plural of claustrum.

claustral (klaws′tral)
Relating to the claustrum.

claustrophobia (klaw-stro-fo′be-a)
A morbid fear of being in a confined place. [L. claustrum, an enclosed space, + G. phobos, fear]

claustrophobic (klaw-stro-fo′bik)
Relating to or suffering from claustrophobia.

claustrum, pl .claustra (klaws′trum, klaws′tra)
1. One of several anatomic structures bearing a resemblance to a barrier. 2. [TA] A thin, vertically placed lamina of gray matter lying close to the putamen, from which it is separated by the external capsule. C. consists of two parts: 1) an insular part and 2) a temporal part between putamen and the temporal lobe. Cells of the c. have reciprocal connections with sensory areas of the cerebral cortex. [L. barrier] c. gutturis, c. oris obsolete term for soft palate. c. virginale an obsolete term for hymen.

clausura (klaw-soo′ra)
SYN: atresia. [L. a lock, bolt, fr. claudo, to close]

clava (kla′va)
SYN: gracile tubercle. [L. a club]

claval (kla′val)
Relating to the clava.

clavate (kla′vat)
Club-shaped. [L. clava, a club]

Claviceps purpurea (klav′i-seps poor-poo′re-a)
See ergot. [L. clava, club, + caput, head]

clavicle (klav′i-kl) [TA]
A doubly curved long bone that forms part of the shoulder girdle. Its medial end articulates with the manubrium sterni at the sternoclavicular joint, its lateral end with the acromion of the scapula at the acromioclavicular joint. SYN: clavicula [TA] , collar bone.

clavicula, pl .claviculae (kla-vik′oo-la, -li) [TA]
SYN: clavicle. [L. c., a small key, fr. clavis, key]

clavicular (kla-vik′u-lar)
Relating to the clavicle.

claviculus, pl .claviculi (kla-vik′u-lus, -li)
One of the perforating collagen fibers of bone. [Mod. L. dim. of L. clavus, a nail]

clavulanic acid (klav-u-lan′ik)
A beta-lactam structurally related to the penicillins that inactivate β-lactamase enzymes in penicillin-resistant organisms; usually used in combination with penicillins to enhance and broaden the spectrum of the penicillins.

clavus, pl .clavi (kla′vus, -vi)
1. A small conical callosity caused by pressure over a bony prominence, usually on a toe. SYN: corn. [L. a nail, wart, corn]

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