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Medical Dictionary


coagulative (ko-ag′u-la-tiv)
Causing coagulation. SYN: coagulant (2) .

coagulopathy (ko-ag-u-lop′a-the)
A disease affecting the coagulability of the blood. consumption c. a disorder in which marked reductions develop in blood concentrations of platelets with exhaustion of the coagulation factors in the peripheral blood; often used as a synonym for disseminated intravascular coagulation.

coagulum, pl .coagula (ko-ag′u-lum, -la)
A clot or a curd; a soft, nonrigid, insoluble mass formed when a sol. undergoes coagulation. [L. a means of coagulating, rennet]

co-alcoholic (ko-al-ko-hol′ik)
1. The person(s) who enables an alcoholic by assuming responsibilities on the alcoholic's behalf, minimizing or denying the problem drinking, or making amends for the alcoholic's behavior. 2. Pertaining to the c. or to co-alcoholism. SEE ALSO: splinting.

co-alcoholism (ko-al′ko-hol-izm)
The constellation of attitudes, attributes, and behaviors of the person who enables the alcoholic, which are necessary for the attainment of a symbiotic balance between alcoholic and co-alcoholic. SEE ALSO: symbiosis.

coalescence (ko-a-les′ens)
Fusion of originally separate parts. SYN: concrescence (1) .

coal oil (kol)
SYN: petroleum.

coal tar
A by-product obtained during the destructive distillation of bituminous coal; a very dark semisolid of characteristic naphthalenelike odor and a sharp, burning taste; used in the treatment of skin diseases.

coapt (ko′apt)
To join or fit together.

coaptation (ko-ap-ta′shun)
Joining or fitting together of two surfaces; e.g., the lips of a wound or the ends of a broken bone. [L. co-apto, pp. -aptatus, to fit together]

coarct (ko-arkt′)
To restrict or press together. SYN: coarctate (1) . [L. co-arcto, pp. -arctatus, to press together]

coarctate (ko-ark′tat)
1. SYN: coarct. 2. Pressed together.

coarctation (ko-ark-ta′shun)
A constriction, stricture, or stenosis. aortic c. congenital narrowing of the aorta, usually located just distal to the left subclavian artery, causing upper-extremity hypertension, excess left ventricular workload, and diminished blood flow to the lower extremities and abdominal viscera. reversed c. aortic arch syndrome in which blood pressure in the arms is lower than in the legs.

coarctectomy (ko′ark-tek′to-me)
Excision of a coarctation (of the aorta).

coarctotomy (ko-ark-tot′o-me)
Division of a stricture. [coarct + G. tome, cutting]

CoAS&cbond;, CoASH
Symbols for the coenzyme A radical and reduced coenzyme A, respectively.

coat (kot)
1. The outer covering or envelope of an organ or part. 2. One of the layers of membranous or other tissues forming the wall of a canal or hollow organ. See tunic. buffy c. the upper, lighter portion of the blood clot (coagulated plasma and white blood cells), occurring when coagulation is delayed so that the red blood cells have had time to settle; the portion of centrifuged, anticoagulated blood which contains leukocytes and platelets. SYN: crusta inflammatoria, crusta phlogistica, leukocyte cream. muscular c. muscular layer. muscular c. of bronchi muscular layer of bronchi. muscular c. of colon muscular layer of colon. muscular c. of ductus deferens muscular layer of ductus deferens. muscular c. of esophagus muscular layer of esophagus. muscular c. of female urethra muscular layer of female urethra. muscular c. of gallbladder muscular layer of gallbladder. muscular c. of intermediate part of male urethra muscular layer of intermediate part of (male) urethra. muscular c. of intermediate part of male urethra muscular layer of prostatic urethra. muscular c. of large intestine muscular layer of large intestine. muscular c. of male urethra SYN: muscular layer of male urethra. muscular c. of pharynx muscular layer of pharynx. muscular c. of prostatic urethra SYN: muscular layer of prostatic urethra. muscular c. of rectum muscular layer of rectum. muscular c. of small intestine muscular layer of small intestine. muscular c. of spongy part of male urethra muscular layer of spongy (male) urethra. muscular c. of stomach muscular layer of stomach. SEE ALSO: oblique fibers of muscular layer of stomach, under fiber. muscular c. of trachea muscular layer of trachea. muscular c. of ureter muscular layer of ureter. muscular c. of urinary bladder muscular layer of urinary bladder. muscular c. of uterine tube muscular layer of uterine tube. muscular c. of uterus SYN: myometrium. muscular c. of vagina muscular layer of vagina. sclerotic c. SYN: sclera. serous c. serosa. serous c. of peritoneum serosa of peritoneum.

coating (kot′ing)
A covering; a layer of some substance spread over a surface. antireflection c. a film of magnesium fluoride spread on a lens to minimize reflections.

CoA transferases [EC 2.8.3.x]
Thiaphorases;enzymes transferring CoA from acetyl-CoA or succinyl-CoA to other acyl radicals.

George, British ophthalmologist, 1876–1915. See C. disease.

cobalamin (Cbl) (ko-bal′a-min)
General term for compounds containing the dimethylbenzimidazolylcobamide nucleus of vitamin B12. ATP c. adenoxyltransferase an enzyme that catalyzes the reaction of ATP, water, and c. to form orthophosphate, pyrophosphate, and adenoxylcobalamin. Adenosylcobalamin is required by methylmalonyl-CoA mutase. A deficiency of ATP c. adenosyltransferase will lead to methylmalonic acidemia. c. concentrate the dried, partially purified product resulting from the growth of selected Streptomyces cultures or other c.-producing microorganisms; contains at least 500 μg of c. in each gram.

cobalt (Co) (ko′bawlt)
A steel-gray metallic element, atomic no. 27, atomic wt. 58.93320; a bioelement and a constituent of vitamin B12; certain of its compounds are pigments, e.g., c. blue. [Ger. kobalt, goblin or evil spirit]

cobalt-57 (57Co)
Half-life, 271.8 days; decays by electron capture with emission of a medium energy (122.06 keV) gamma ray. Used as a diagnostic aid with some metabolic disorders.

cobalt-58 (58Co)
Positron emitter with half-life of 70.88 days.

cobalt-60 (60Co)
Half-life, 5.271 years; emits beta particles and energetic gamma rays, for which reason it is used in radiation teletherapy and diagnostics in place of radium (radon) or x-rays. It is also used as a diagnostic aid in vitamin B12-related problems.

cobaltous chloride (ko-bawl′tus)
Used in the treatment of various types of refractory anemia to improve the hematocrit, hemoglobin, and erythrocyte count.

Stanley, U.S. neuropathologist, 1887–1968. See C. syndrome.

cobra (ko′bra)
Most cobras are members of the highly venomous snake genus, Naja (family Elapidae); six species are recognized, all African except for the Asiatic c.; typical behavior includes spreading of the neck (hood), rearing one-third of the body off of the ground, and, in some species, the spitting of venom, which is primarily neurotoxic. There are also cobras that belong to the genera Pseudohaje, Hemachatus, and Ophiophagus. [Port. snake, from L. coluber, snake]

cobrotoxin (ko′bro-tok-sin)
A polypeptide of 62 residues; action on cells is similar to that of melittin in that it promotes disruption of membranes; used as an investigational antirheumatic agent. SYN: cobra toxin, direct lytic factor of cobra venom.

cobyric acid (ko-bir′ik)
The hexa-amide of cobyrinic acid; a part of the vitamin B12 structure. SYN: cobyrinamide, factor V1a.

cobyrinamide (ko-bir-in′a-mid)
SYN: cobyric acid.

cobyrinic acid (ko-bir-in′ik)
Corrin with 8 methyl groups at positions 1, 2, 5, 7, 12 (2), 15, and 17; &cbond;CH2COOH groups at positions 2, 7, and 18; &cbond;CH2CH2COOH groups at positions 3, 8, 13, and 17; and divalent cobalt centered among the four nitrogens. The acid side chains are designated, in numeric order, a, b, c, d, e, f, and g. It is a part of the vitamin B12 structure.

Abbreviation for cathodal opening contraction.

coca (ko′ka)
The dried leaves of Erythroxylon c., yielding not less than 0.5% of ether-soluble alkaloids; the source of cocaine and several other alkaloids. [S. Am.]

cocaine (ko-kan′)
C17H21NO4; Benzoylmethylecgonine;a crystalline alkaloid obtained from the leaves of Erythroxylon coca (family Erythroxylaceae) and other species of Erythroxylon, or by synthesis from ecgonine or its derivatives; a potent central nervous system stimulant, vasoconstrictor, and topical anesthetic, widely abused as a euphoriant and associated with the risk of severe adverse physical and mental effects.The coca bush is indigenous to Bolivia and Peru, where for centuries natives have chewed its leaves along with limestone pellets or plant ashes in order to withstand hunger, thirst, and fatigue. During the 19th century c. was widely used in medicine as a stimulant, antidepressant, and topical anesthetic, but because of its strong potential for inducing dependency it is no longer administered systemically. Its popularity as a recreational drug waned slightly after amphetamines became available in the 1920s but returned in the 1960s. C. is generally sold on the street as the hydrochloride salt, a fine white powder known as “coke,” “C,” “snow,” “flake,” or “blow.” Street dealers cut or adulterate it with inert substances such as cornstarch, talcum powder, and sugar, or with active drugs such as procaine and benzocaine. In powder form it is usually “snorted” into the nostrils, although it may also be absorbed through the buccal, vaginal, or rectal mucosa or injected. A smokable form of c. can be prepared from the hydrochloride by a process called “free-basing.” Production of pure free-base c. is hazardous because it employs highly flammable solvents. The drug commonly called “crack” is a crude form of free base prepared from c. hydrochloride with ammonia or sodium bicarbonate and water. The hardened product of this process is cracked into irregular fragments called “rock,” “ready rock,” “french fries,” or “teeth.” Street use of crack exploded upon its introduction in the 1980s, causing increases in emergency department admissions for c. overdose, drug-related deaths, and births of c.-dependent babies. Administration of c. quickly produces intense euphoria, accompanied by a sense of increased energy, alertness, and self-confidence and diminished need for food and sleep. Pulse, blood pressure, and respiratory rate are increased. Higher doses can lead to bizarre or violent behavior, paranoia, chest pain, tremors, seizures, coma, and death due to coronary artery spasm or respiratory arrest. Smoked crack c. reaches the brain more quickly than snorted c.. The effects of either form wear off in less than 30 minutes, to be succeeded by profound depression, irritability, and fatigue (“coke crash”). Prolonged use of c. leads to chronic symptoms including restlessness, irritability, depression, insomnia, and a reversible psychosis characterized by paranoia, hallucinations, and delusions. Repeated snorting of c. causes rhinitis, which can culminate in perforation of the nasal septum. C. is not truly addictive because tolerance does not develop; in fact, some regular users note increasing sensitivity to its physical and psychologic effects. But psychological dependency can develop in less than 2 weeks. Withdrawal is associated with intense craving for another dose; sustained abstinence may lead to anxiety, depression, and disorders of appetite and sleep. crack c. a derivative of c., usually smoked, resulting in a brief, intense high. Crack is relatively inexpensive and extremely addictive. See street drug. c. hydrochloride a water-soluble salt used for local anesthesia of the eye or mucous membranes.

cocainization (ko′kan-i-za′shun)
Production of topical anesthesia of mucous membranes by the application of cocaine.

cocarboxylase (ko-kar-boks′i-las)
SYN: thiamin pyrophosphate.

cocarcinogen (ko-kar′si-no-jen)
A substance that works symbiotically with a carcinogen in the production of cancer.

Coccaceae (kok-ka′se-e)
An obsolete term for a family of Eubacteriales which included all the spherical cells dividing in one (Streptococcus), two (Micrococcus), or three (Sarcina) planes, then forming cells, pairs, tetrads, cubes or larger packets, or chains. [G. kokkos, a berry]

coccal (kok′al)
Relating to cocci.

cocci (kok′si)
Plural of coccus.

Coccidia (kok-sid′e-a)
A subclass of important protozoa (class Sporozoea, phylum Apicomplexa) in which the mature trophozoites are small and typically intracellular; schizogony and sporogony can occur in the same host, in contrast to the gregarines (subclass Gregarinia of class Sporozoea), which have large extracellular trophozoites in various invertebrates and do not reproduce by schizogony. SYN: Coccidiasina. [Mod. L., fr. G. kokkos, berry]

coccidia (kok-sid′e-a)
Plural of coccidium.

coccidial (kok-sid′e-al)
Relating to coccidia.

Coccidiasina (kok-sid′e-a-si′na)
SYN: Coccidia.

coccidioidal (kok-sid-e-oy′dal)
Referring to the disease or to the infecting organism of coccidioidomycosis.

Coccidioides (kok-sid-e-oy′dez)
A genus of fungi found in the soil of the semi-arid areas of the Southwestern U.S. and smaller areas throughout Central and South America, but has not been found elsewhere. The only pathogenic species, C. immitis, causes coccidioidomycosis. [coccidium + G. eidos, resemblance]

coccidioidin (kok-sid-e-oy′din)
A sterile solution containing the by-products of growth of Coccidioides immitis; used as an intracutaneous skin test, diagnostically more valuable in non-endemic areas.

coccidioidoma (kok-sid′e-oy-do′ma)
A benign localized residual granulomatous lesion or scar in a lung following primary coccidioidomycosis.

coccidioidomycosis (kok-sid-e-oy′do-mi-ko′sis)
A variable, benign, severe, or sometimes fatal systemic mycosis due to inhalation of arthroconidia of Coccidioides immitis. In benign forms of the infection, the lesions are limited to the upper respiratory tract, lungs, and near lymph nodes; in a low percentage of cases, the disease disseminates to other visceral organs, meninges, bones, joints, and skin and subcutaneous tissues. SYN: Posadas disease. [coccidioides + G. mykes, fungus, + -osis, condition] disseminated c. a severe, chronic, and progressive form of c. with spread from the lung to other organs. Patients with this disease are usually significantly immunocompromised. primary c. a disease common in the San Joaquin Valley of California and certain additional areas in the southwestern U.S. as well as the Chaco region of Argentina, caused by inhalation of the arthroconidia of Coccidioides immitis; acute onset of respiratory symptoms accompanied by fever, aches, malaise, arthralgia, headache, and occasionally an early erythematous or papular eruption; erythema multiforme or erythema nodosum may appear. SYN: desert fever, San Joaquin fever, San Joaquin Valley disease, San Joaquin Valley fever, valley fever. primary extrapulmonary c. a rare form of c. presenting near the site of local trauma with painless firm nodules occurring at one to two weeks, accompanied by regional adenopathy, with spontaneous healing in a few weeks. secondary c. progressive or disseminated extrapulmonary granulomatous lesions following primary c.. SYN: coccidioidal granuloma. subclinical c. a form of c. that does not come to medical attention because respiratory symptoms are mild and self-limited.

coccidiosis (kok-sid-e-o′sis)
Group name for diseases due to any species of coccidia; a common and serious protozoan disease of many species of domestic animals and birds and many wild animals kept in captivity; both intestinal and pulmonary c. have been reported in humans with AIDS.

coccidiostat (kok-sid′e-o-stat)
A chemical agent generally added to animal feed to partially inhibit or delay the development of coccidiosis.

coccidium, pl .coccidia (kok-sid′e-um, -e-a)
Common name given to protozoan parasites (order Eucoccidiida) in which schizogony occurs within epithelial cells, generally in the intestine, but in some species in the bile ducts and kidney; the final product of sexual fusion and differentiation that occurs within the host, the oocyst, generally passes to the soil in the feces, undergoes sporulation, and then acts as the infective form for another host. Coccidia are parasitic in most domestic and wild birds and mammals, occasionally in humans, and are highly host-specific; the majority are nonpathogenic, but certain species rank among the most serious and economically important pathogens, causing coccidiosis in birds and mammals. See Isospora, Cryptosporidium. [Mod. L. dim. of G. kokkos, berry]

coccinella (kok-sin-el′a)
SYN: cochineal.

coccinellin (kok-si-nel′in)
The coloring principle derived from cochineal.

coccobacillary (kok′o-bas′i-lar-e)
1. Relating to a coccobacillus. 2. Of organisms exhibiting coccal, bacillary, and intermediate forms.

coccobacillus (kok′o-ba-sil′us)
A short, thick bacterial rod of the shape of an oval or slightly elongated coccus. [G. kokkos, berry]

coccoid (kok′oyd)
Resembling a coccus. [G. kokkos, berry, + eidos, resemblance]

cocculin (kok′u-lin)
SYN: picrotoxin.

coccus, pl .cocci (kok′us, kok′si)
1. A bacterium of round, spheroidal, or ovoid form. 2. SYN: cochineal. [G. kokkos, berry] Neisser c. SYN: Neisseria gonorrhoeae. Weichselbaum c. SYN: Neisseria meningitidis.

coccycephaly (kok′si-sef′a-le)
A malformation in which the cephalic profile suggests a beak. [G. kokkyx, cuckoo, + kephale, head]

coccydynia (kok-se-din′e-a)
Pain in the coccygeal region. SYN: coccygodynia, coccyodynia. [coccyx + G. odyne, pain]

coccygeal (Co) (kok-sij′e-al)
Relating to the coccyx.

coccygectomy (kok-se-jek′to-me)
Removal of the coccyx. [coccyx + G. ektome, excision]

See c. muscle.


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