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Medical Dictionary


chiropractic (ki-ro-prak′tik)
A system that, in theory, uses the recuperative powers of the body and the relationship between the musculoskeletal structures and functions of the body, particularly of the spinal column and the nervous system, in the restoration and maintenance of health. [chiro- + G. praktikos, efficient]

chiropractor (ki-ro-prak′tor)
One who is licensed and certified to practice chiropractic.

A genus of the invertebrate phylum Cnidaria that includes the sea wasp. C. quadrumanus the sea wasp, the most venomous jellyfish inhabiting the waters surrounding the United States. SEE ALSO: jellyfish. SYN: box jelly, sea wasp.

Chiroptera (ki-rop′ter-a)
The bats, an order of placental mammals of worldwide distribution, characterized by a modification of the forelimbs that enables them to fly. They are capable of emitting ultrasonic sounds that enable them to echolocate, find flying insect prey, and avoid objects in the dark. Though mostly insectivorous, some species feed on nectar, fruit, fish, and blood; the blood-feeding and insectivorous species are important reservoir hosts of rabies. [chiro- + G. pteron, wing]

chiroscope (ki′ro-skop)
A haploscopic instrument used for coordinating hand and eye as the patient draws while looking through it. [chiro- + G. skopeo, to view]

chirospasm (ki′ro-spazm)
SYN: cheirospasm.

Abbreviation for L. chirurgicalis, surgical.

chirurgeon (ki-rer′jon)
Obsolete term for surgeon. [G. cheirourgos, fr. cheir, hand, + ergon, work]

chirurgery (ki-rer′jer-e)
Obsolete term for surgery. [G. cheirourgia]

chirurgical (ki-rer′ji-kal)
Obsolete term for surgical. [L. surgical, fr. chirurgia, surgery, fr. G. cheirourgia, handicraft, fr. cheir, hand + ergon, work]

chisel (chiz′l)
A single beveled end-cutting blade with a straight or angled shank used with a thrust along the axis of the handle for cutting or splitting dentin and enamel. binangle c. a c. with an angled shank to which a second angle is added in order to bring the cutting edge nearly in line with the axis of the handle so as to restore balance and to prevent it from turning about the axis; used when a c. must be angled for access.

chi-square (ki′ skwar)
A statistical technique whereby variables are categorized to determine whether a distribution of scores is due to chance or experimental factors.

chitin (ki′tin)
A linear polymer of N-acetyl-d-glucosamine, linked β(1→4), similar in structure to cellulose and the second most abundant polysaccharide in nature, comprising the horny substance in the exoskeleton of beetles, crabs, certain microorganisms, etc., as well as in some plants and fungi.

chitinase (ki′ti-nas)
An enzyme catalyzing the random hydrolysis of β(1→4) linkages in chitin (ultimately releasing N-acetyl-d-glucosamine); some enzymes of this type display lysozyme activity. SYN: poly-β-glucosaminidase.

chitinous (ki′tin-us)
Of or relating to chitin.

chitobiose (ki-to-bi′os)
The disaccharide repeating unit in chitin; differs from cellobiose only in the presence of an N-acetylamino group on carbon-2 in place of the hydroxyl group. However, the nonacetylated form is also referred to as c..

chitosamine (ki-to′sa-men)
d-Glucosamine. See glucosamine.

chiufa (che-oo′fa)
An acute gangrenous proctitis and colitis with high fever, seen in southern Africa and South America at high altitudes; in women, the vulva and vagina may be affected. SYN: kanyemba.

Abbreviation for crown-heel length.

Chlamydia (kla-mid′e-a)
The only genus of the family Chlamydiaceae, including all the agents of the psittacosis-lymphogranuloma-trachoma disease groups; c. are obligatory intracellular spherical or ovoid bacteria with a complex intracellular life cycle; the infective form is the elementary body, which penetrates the host cell, replicating as the rediculate body by binary fission; replication occurs in a vacuole called the inclusion body; c. lack peptidoglycan in their cell walls; the type species is C. trachomitis. Formerly called Betsonia. SYN: Chlamydozoon. [G. chlamys, cloak] C. pneumoniae a bacterial species first isolated in 1986 and currently recognized as a common cause of pneumonia, bronchitis, rhinosinusitis, and pharyngitis in both adults and children. SYN: TWAR.C. pneumoniae is responsible for about 25% of cases of acute bronchitis and 10% of community-acquired pneumonia. Recent studies have suggested that it may also play a role in the genesis of cardiovascular disease and late-onset Alzheimer dementia. Like C. trachomatis and C. psittaci, this organism is an occasional cause of myocarditis and endocarditis. Elevated levels of antibody to C. pneumoniae are found in persons with acute myocardial infarction (MI), and in persons showing significant atheroma formation at autopsy, significantly more often than in control groups. The organism has been detected by immunocytochemistry, polymerase chain reaction, and electron microscopy in macrophages and smooth muscle cells of atheromatous plaques of the aorta, coronary arteries, and carotid arteries (surgical and autopsy specimens), but not in normal arteries. The incidence of acute infection in MI patients, as detected by throat culture, is higher than in the general public. A retrospective review of medical records of persons with acute MI showed that they were less likely than matched controls to have been treated during the preceding 3 years with tetracycline or quinolone antibiotics, which are active against C. pneumoniae. To date, however, prospective studies have not shown an association between the presence of IgG antibody to C. pneumoniae and an increased risk of atherothrombotic disease. Researchers have speculated that infection with C. pneumoniae may be one of several factors capable of initiating changes that culminate in atherosclerosis, or that reinfection may trigger coronary atherothrombosis. Antibody to C. pneumoniae is also found in persons with severe hypertension at about twice the incidence rate for the general public. In addition, the organism has been detected in microglia and astroglia of the hippocampus and temporal cortex in persons with late-onset Alzheimer disease with much greater frequency than in normal brains. C. psittaci bacterial organisms that resemble C. trachomatis, but that form loosely bound intracytoplasmic microcolonies up to 12 μm in diameter, do not produce glycogen in sufficient quantity to be detected by iodine stains, and are not susceptible to sulfadiazine. Various strains of this species cause psittacosis in humans and ornithosis in nonpsittacine birds; pneumonitis in cattle, sheep, swine, cats, goats, and horses; enzootic abortion of ewes; bovine sporadic encephalomyelitis; enteritis of calves; epizootic chlamydiosis of muskrats and hares; encephalitis of opossum; and conjunctivitis of cattle, sheep, and guinea pigs. C. trachomatis spherical nonmotile bacteria that are obligatory intracellular organisms; they form compact intracytoplasmic microcolonies up to 10 μm in diameter which (by division) give rise to infectious spherules 0.3 μm or more in diameter, accumulate glycogen for a limited period in sufficient quantity to be detected by iodine stain, and are usually susceptible to sulfadiazine, tetracycline, and quinalones; various strains of this species cause trachoma, inclusion and neonatal conjunctivitis, lymphogranuloma venereum, mouse pneumonitis, nonspecific urethritis, epididymitis, cervicitis, salpingitis, proctitis, and pneumonia; chief agent of bacterial sexually transmitted diseases in the U.S.; the type species of the genus Chlamy dia.

chlamydia, pl .chlamydiae (kla-mid′e-a, -mid′e-e)
A vernacular term used to refer to any member of the genus C..

Chlamydiaceae (kla-mid′e-a′se-e)
A family of the order Chlamydiales (formerly included in the order Rickettsiales) that includes the agents of the psittacosis-lymphogranuloma-trachoma group. The family contains small, coccoid, Gram-negative bacteria that resemble rickettsiae but that differ from them significantly by possessing a unique, obligately intracellular developmental cycle; intracytoplasmic microcolonies give rise to infectious forms by division. The classification of these organisms previously was in a state of flux, but they are now placed in a single genus, Chlamydia, the type genus of the family.

chlamydial (kla-mid′e-al)
Relating to or caused by any bacterium of the genus Chlamydia.

chlamydiosis (kla-mid-e-o′sis)
General term for diseases caused by Chlamydia species. SEE ALSO: ornithosis, psittacosis.

chlamydoconidium (klam′i-do-ko-nid′e-um)
A thallic conidium that is thick-walled and may be terminal or intercalary. Seen in a form of asexual reproduction. [G. chlamys, cloak, + conidium]

Chlamydophrys (kla-mid′o-fris)
A genus of shelled amebas, commonly found as fecal protozoans. [G. chlamys, cloak, + ophrys, brow]

Chlamydozoon (klam′i-do-zo′on)
SYN: Chlamydia.

chloasma (klo-az′ma)
Melanoderma or melasma characterized by the occurrence of extensive brown patches of irregular shape and size on the skin of the face and elsewhere; the pigmented facial patches if confluent are also called the mask of pregnancy, and are associated most commonly with pregnancy and use of oral contraceptives. SEE ALSO: melasma. [G. chloazo, to become green] c. bronzinum a bronze-colored pigmentation, probably produced by hormone imbalance, occurring in gradually increasing areas on the face, neck, and chest in persons exposed continuously to the tropical sun; similar to c. of the temperate zone, but intensified because of strong sunlight. SYN: tropical mask.

chlophedianol hydrochloride (klo-fe-di′a-nol)
An antitussive agent related chemically to the antihistamines.

chlor-, chloro-
1. Combining form denoting green. 2. Combining form denoting association with chlorine. [G. chloros, green]

chloracetic acid (klor-a-se′tik)
SYN: chloroacetic acid.

chloracne (klor-ak′ne)
An acnelike eruption due to occupational contact, by inhalation or ingestion or through the skin, with certain chlorinated compounds (naphthalenes and diphenyls) used as insulators, insecticides, fungicides, and herbicides, including Agent Orange; keratinous plugs (comedones) form in the pilosebaceous orifices, and variously sized small papules (2 to 4 mm) develop. SYN: tar acne.

chloral (klor′al)
A thin oily liquid with a pungent odor, formed by the action of chlorine gas on alcohol. SYN: anhydrous c.. anhydrous c. SYN: c.. c. betaine the adduct formed by c. hydrate and betaine; it is slowly hydrolyzed in the alimentary tract to c. hydrate; used as a hypnotic and sedative. c. hydrate a hypnotic, sedative, and anticonvulsant; it is also used externally as a rubefacient, anesthetic, and antiseptic.

chloral alcoholate
A complex of chloral and ethanol. Prepared by refluxing trichloroacetaldehyde (chloral) or chloral hydrate with alcohol. Alleged to be an active constituent of a &dquor;Mickey Finn.&dquor;

chloralism (klor′al-izm)
Habitual use of chloral compounds as an intoxicant, or the symptoms caused thereby.

chlorambucil (klor-am′bu-sil)
A nitrogen mustard derivative that depresses lymphocytic proliferation and maturation. SYN: chloraminophene, chloroambucil.

chloramine B (klor′a-men)
A nontoxic antiseptic substance used in wound irrigation as a substitute for chloramine T.

chloramine T
A nontoxic but strong antiseptic used in the irrigation of wounds and infected cavities. SYN: chlorazene.

chloraminophene (klor-am′i-no-fen)
SYN: chlorambucil.

chloramiphene (klor-am′i-fen)
SYN: clomiphene citrate.

chloramphenicol (klor-am-fen′i-kol)
An antibiotic originally obtained from Streptomyces venezuelae. It is effective against a number of pathogenic microorganisms including Staphylococcus aureus, Brucella abortus, Friedländer bacillus, and the organisms of typhoid, typhus, and Rocky Mountain spotted fever; active by mouth. A serious reaction resulting in marrow damage with agranulocytosis or aplastic anemia may occur. Gray baby syndrome may occur in newborns due to a lack of glucoronyltransferase needed to metabolize the drug. c. acetyl transferase (CAT) a bacterial enzyme often used as a marker for examining the control of eucaryotic gene expression. c. palmitate same action and use as c.; was widely used in suspension for pediatric injections. c. sodium succinate the water-soluble sodium succinate derivative of c., suitable for parenteral administration; antibacterial activity, uses, and side effects are similar to those of the parent compound.

chlorate (klor′at)
A salt of chloric acid.

chlorazanil (klo-raz′a-nil)
A diuretic.

chlorazene (klor′a-zen)
SYN: chloramine T.

chlorazol black E (klor′a-zol) [C.I. 30235]
An acid dye, used as a fat and general tissue stain, and to stain protozoa in fecal smears or in tissues.

chlorbenzoxamine (klor-ben-zok′sa-men)
An anticholinergic agent. SYN: chlorbenzoxyethamine.

chlorbenzoxyethamine (klor′ben-zok-se-eth′a-men)
SYN: chlorbenzoxamine.

chlorbetamide (klor-bet′a-mid)
An amebicide.

chlorbutol (klor-bu′tol)
SYN: chlorobutanol.

chlorcyclizine hydrochloride (klor-sik′li-zen)
An H1 antihistaminic agent.

chlordane (klor′dan)
A chlorinated hydrocarbon used as an insecticide; it may be absorbed through the skin with resultant severe toxic effects: hyperexcitability of central nervous system, tremors, lack of muscular coordination, convulsions, and death; also causes damage to the liver, kidneys, and spleen. It is only mildly toxic to animals.

chlordantoin (klor-dan′to-in)
A topical antifungal agent.

chlordiazepoxide hydrochloride (klor′di-az-e-pok′sid)
The hydrochloride of 7-chloro-2-methylamino-5-phenyl-3H-1,4-benzodiazepine-4-oxide; an antianxiety agent. An early benzodiazepine.

chloremia (klor-e′-me-a)
1. SYN: chlorosis. 2. SYN: hyperchloremia.

chlorethene homopolymer (klor′eth-en)
SYN: polyvinyl chloride.

chlorguanide hydrochloride (klor-gwah′nid)
SYN: chloroguanide hydrochloride.

chlorhexidine hydrochloride (klor-hek′si-den)
A topical antiseptic.

chlorhydria (klor-hi′dre-a)
SYN: hyperchlorhydria.

chloric acid (klor′ik)
An acid of pentavalent chlorine, HClO3, existing only in solution and as chlorates.

chloride (klor′id)
A compound containing chlorine, at a valence of −1, as in the salts of hydrochloric acid. carbamylcholine c. a cholinomimetic drug that reacts with and activates both muscarinic and nicotinic receptors. It is slowly hydrolyzed and thus its effects far outlast those of acetylcholine. Used medically to stimulate smooth muscle, as in paralytic ileus following surgery.

chloridimetry (klor-i-dim′e-tre)
The process of determining the amount of chlorides in the blood or urine, or in other fluids.

chloridometer (klor-i-dom′e-ter)
An apparatus for determining the amount of chlorides in blood or urine, or other fluids.

chloriduria (klor-i-doo′re-a)
SYN: chloruresis.

chlorin (klor′in)
2,3-Dihydroporphin(e); 2,3-dihydroporphyrin;one of the root structures of the chlorophylls (for structure, see porphyrin). Addition of the two-carbon bridge (see structure of chlorophyll) to c. yields phorbin(e); addition of side chains yields the phorbides, distinguished by a number of arbitrary prefixes (those found in the chlorophylls are pheo- and bacteriopheophorbide); esterification of the propionic group by phytyl yields the respective phytins, and the addition of magnesium yields the chlorophylls (magnesium phytinates). See porphyrins.

chlorinated (klor′in-at-ed)
Having been treated with chlorine.

chlorindanol (klor-in′da-nol)
A spermicide.

chlorine (Cl) (klor′en)
1. A greenish, toxic, gaseous element; atomic no. 17, atomic wt. 35.4527; a halogen used as a disinfectant and bleaching agent in the form of hypochlorite or of c. water, because of its oxidizing power. One of the bioelements. 2. The molecular form of c. (1), Cl2 (dichloride). [G. chloros, greenish yellow]

chlorine group
The halogens.

chloriodized (klor-i′o-dizd)
Containing both chlorine and iodine.

chloriodized oil
Chlorinated and iodized peanut oil formed by the chemical addition of iodine monochloride; formerly used for radiography of sinuses and bronchi. SYN: iodochlorol.

chloriodoquin (klor′e-o-do′kwin)
SYN: iodochlorhydroxyquin.

chlorisondamine chloride (klor-i-son′da-men)
A quaternary ammonium compound with ganglionic blocking action similar to, but more potent than, hexamethonium and pentolinium; was used in the management of severe hypertension, including the malignant phase.

chlorite (klor′it)
A salt of chlorous acid; the radical ClO2−.

chlormadinone acetate (klor-mad′i-non)
A progesterone derivative used in conjunction with estrogen as an oral contraceptive.

chlormerodrin (klor-mer′od-rin)
A mercurial diuretic chemically related to meralluride.


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