R

R R arginine; organic radical; rate; electrical resistance; respiration; rhythm; right; roentgen.

R R resistance (3).

R– R– a stereodescriptor used to specify the absolute configuration of compounds having asymmetric carbon atoms; opposed to S-.

R_A R_χ airway resistance.

[L.] recipe (take); see prescription.

r r ring chromosome.

Ra Ra radium.

rabeprazole rabéprazole a proton pump inhibitor used as the sodium salt to inhibit gastric acid secretion in the treatment of gastroesophageal reflux disease and conditions marked by excessive secretion of gastric acid.

rabid enragé, rabique affected with rabies; pertaining to rabies.

rabies rage an acute, usually fatal, infectious viral disease of the central nervous system of mammals, human infection resulting from the bite of a rabid animal (bats, dogs, etc.). In the later stages, it is marked by paralysis of the muscles of deglutition and glottal spasm provoked by the drinking or the sight of liquids, and by maniacal behavior, convulsions, tetany, and respiratory paralysis. Adj.: rabid.

racemase racémase an enzyme that catalyzes inversion around the asymmetric carbon atom in a substrate having only one center of asymmetry.

racemate racémate a racemic mixture or compound.

racemic racémique optically inactive, being composed of equal amounts of dextrorotatory and levorotatory isomers.

racemization racémisation the transformation of one half of the molecules of an optically active compound into molecules having exactly the opposite configuration, with complete loss of rotatory power because of the statistical balance between the equal numbers of dextro- and levorotatory molecules.

racemose racémeux shaped like grapes on their stem.

racephedrine racéphédrine the racemic form of ephedrine, having the same actions and uses; used as the hydrochloride salt.

rachialgia rachialgie rachiodynia.

rachicentesis rachicentèse lumbar puncture.

rachidial rachidien spinal (1).

rachidian rachidien spinal (1).

rachigraph rachigraphe an instrument for recording the outlines of the spine and back.

rachilysis rachilyse correction of lateral curvature of the spine by combined traction and pressure.

rachi(o)- rachi- word element [Gr.], spine.

rachiodynia rachiodynie pain in the vertebral column.

rachiometer rachimètre an apparatus for measuring spinal curvature.

rachiotomy rachitomie incision of a vertebra or the vertebral column.

rachis rachis vertebral column.

rachischisis rachischisis congenital fissure of the vertebral column. r. posterior r. postérieur spina bifida.

rachitic rachitique pertaining to rickets.

rachitis rachitisme rickets.

rachitogenic rachitigène causing rickets.

rad rad radiation absorbed dose: a unit of measurement of the absorbed dose of ionizing radiation, corresponding to an energy transfer of 100 ergs per gram of any absorbing material.

rad. racine [L.] radix (root).

radectomy radectomie excision of the root of a tooth.

radiad en direction du côté radial toward the radius or radial side.

radial radial 1. pertaining to the radius of the arm or to the radial (lateral) aspect of the arm as opposed to the ulnar (medial) aspect; pertaining to a radius. 2. radiating; spreading outward from a common center.

radialis radialis [L.] radial.

radiatio radiatio pl. radiationes [L.] a radiation or radiating structure.

radiation radiation 1. divergence from a common center. 2. a structure made up of divergent elements, as one of the fiber tracts in the brain. 3. rayonnement energy transmitted by waves through space or through some medium; usually referring to electromagnetic radiation, when used without a modifier. By extension, a stream of particles, such as electrons or alpha particles. acoustic r. r. acoustique a fiber tract arising in the medial geniculate nucleus and passing laterally to terminate in the transverse temporal gyri of the temporal lobe. r. of corpus callosum rayonnement du corps calleux the fibers of the corpus callosum radiating to all parts of the neopallium. corpuscular r. rayonnement corpusculaire streams of subatomic particles emitted in nuclear disintegration, such as protons, neutrons, positrons, and deuterons. electromagnetic r. rayonnement électromagnétique see under wave. ionizing r. rayonnement ionisant corpuscular or electromagnetic radiation capable of producing ionization, directly or indirectly, in its passage through matter. occipitothalamic r., optic r. faisceau thalamo-occipital a fiber tract starting at the lateral geniculate body, passing through the pars retrolentiformis of the internal capsule, and terminating in the striate area on the medial surface of the occipital lobe, on either side of the calcarine sulcus. pyramidal r. rayonnement pyramidal fibers extending from the pyramidal tract to the cortex. tegmental r. faisceau tegmental fibers radiating laterally from the red nucleus. thalamic r’s rayonnement thalamiques fibers which reciprocally connect the thalamus and cerebral cortex by way of the internal capsule, usually grouped into four subradiations (peduncles): anterior, central, inferior, and posterior. ultraviolet r. rayonnement ultraviolet see under ray.

radical radical 1. directed to the root or cause; designed to eliminate all possible extensions of a morbid process. 2. a group of atoms that enters and goes out of chemical combination without change. free r. r. libre a radical that carries an unpaired electron; such radicals are extremely reactive, with a very short half-life.

radicle radicule ramulus; one of the smallest branches of a vessel or nerve.

radicotomy radicotomie rhizotomy.

radiculalgia radiculalgie pain due to disorder of the spinal nerve roots.

radicular radiculaire of or pertaining to a root or radicle.

radiculitis radiculite inflammation of the spinal nerve roots.

radiculoganglionitis ganglioradiculite inflammation of the posterior spinal nerve roots and their ganglia.

radiculomeningomyelitis radiculoméningomyélite meningomyeloradiculitis.

radiculomyelopathy radiculomyélopathie myeloradiculopathy.

radiculoneuritis radiculonévrite acute idiopathic polyneuritis.

radiculoneuropathy radiculoneuropathie disease of the nerve roots and spinal nerves.

radiculopathy radiculopathie disease of the nerve roots. spondylotic caudal r. r. spondylotique caudale compression of the cauda equina due to encroachment upon a congenitally small spinal canal by spondylosis, resulting in neural disorders of the lower limbs.

radi(o)- radi(o)- word element [L.], ray; radiation; emission of radiant energy; radium; radius (bone of the forearm); affixed to the name of a chemical element to designate a radioactive isotope of that element.

radioactivity radioactivité emission of corpuscular or electromagnetic radiations consequent to nuclear disintegration; it is a natural property of all chemical elements of atomic number above 83 and and can be induced in all other known elements. Adj.: radioactive. artificial r., induced r. r. artificielle that produced by bombarding an element with high-velocity particles.

radioallergosorbent radioallergoabsorbant denoting a radioimmunoassay technique for the measurement of specific IgE antibody to a variety of allergens.

radiobicipital radiobicipital pertaining to the radius and the biceps muscle.

radiobiology radiobiologie the branch of science concerned with effects of light and of ultraviolet and ionizing radiations on living tissue or organisms. Adj.: radiobiological.

radiocardiography radiocardiographie graphic recording of variation with time of the concentration, in a selected chamber of the heart, of a radioactive isotope, usually injected intravenously.

radiocarpal radiocarpien pertaining to the radius and carpus.

radiochemistry radiochimie the branch of chemistry dealing with radioactive materials.

radiocolloids radiocolloïdes radioisotopes in pure form in solution; they often behave more like colloids than solutes.

radiocystitis radiocystite radiation cystitis.

radiodensity radiodensité radiopacity.

radiodermatitis radiodermatite a cutaneous inflammatory reaction to exposure to biologically effective levels of ionizing radiation.

radiodiagnosis radiodiagnostic diagnosis by means of x-rays and radiographs.

radiodontics radiodontie dental radiology.

radiodontist radiodontiste a dentist who specializes in dental radiology.

radiogold or radioactif one of the radioactive isotopes of gold, particularly ¹⁹⁸Au; see gold 198.

radiogram radiogramme radiograph.

radiograph radiographie, radio the film produced by radiography.

radiography radiographie the making of film records (radiographs) of internal structures of the body by passing x-rays or gamma rays through the body to act on specially sensitized film. Adj.: radiographic. body section r. r. en coupe tomography. digital r. r. numérique a technique in which x-ray absorption is quantified by assignment of a number to the amount of x-rays reaching the detector; the information is manipulated by a computer to produce an optimal image. electron r. r. électronique a technique in which a latent electron image is produced on clear plastic by passing x-ray photons through a gas with a high atomic number; this image is then developed into a black-and-white picture. mucosal relief r. r. du relief muqueux radiography of the mucosa of the gastrointestinal tract in a double-contrast examination. neutron r. neutronographie that in which a narrow beam of neutrons from a nuclear reactor is passed through tissues, especially useful in visualizing bony tissues. serial r. r. en série the making of several exposures of a particular area at arbitrary intervals. spot-film r. r. visée the making of localized instantaneous radiographic exposures during fluoroscopy.

radiohumeral radiohuméral pertaining to the radius and humerus.

radioimmunity radiorésistance acquise, radio-immunisation diminished sensitivity to radiation.

radioimmunoassay radio-immunoanalyse a highly sensitive and specific assay method that uses the competition between radiolabeled and unlabeled substances in an antigen-antibody reaction to determine the concentration of the unlabeled substance, which may be an antibody or a substance against which specific antibodies can be produced.

radioimmunodiffusion radio-immunodiffusion immunodiffusion conducted with radioisotope-labeled antibodies or antigens.

radioimmunoscintigraphy radio-immunoscintigraphie immunoscintigraphy.

radioimmunosorbent radio-immunosorbent denoting a radioimmunoassay technique for measuring IgE in samples of serum.

radioiodine iode radioactif any radioactive isotope of iodine, particularly ¹²³I, ¹²⁵I, and ¹³¹I; used in diagnosis and treatment of thyroid disease and in scintiscanning.

radioisotope radio-isotope a radioactive isotope; one having an unstable nucleus and emitting characteristic radiation during its decay to a stable form.

radiolabel 1. marqueur radioactive label. 2. marquer to incorporate such a radioactive label into a compound.

radioligand ligand radioactif a radioisotope-labeled substance, e.g., an antigen, used in the quantitative measurement of an unlabeled substance by its binding reaction to a specific antibody or other receptor site.

radiologist radiologue a physician specializing in radiology.

radiology radiologie that branch of the health sciences dealing with radioactive substances and radiant energy and with the diagnosis and treatment of disease by means of both ionizing (e.g., x-rays) and nonionizing (e.g., ultrasound) radiation. Adj.: radiologic, radiological.

radiolucent radioclair permitting the passage of radiant energy, such as x-rays, with little attenuation, the representative areas appearing dark on the exposed film.

radiometer radiomètre an instrument for detecting and measuring radiant energy.

radionecrosis radionécrose tissue destruction due to radiant energy.

radioneuritis radionévrite neuritis from exposure to radiant energy.

radionuclide radionucléide a nuclide that disintegrates with the emission of corpuscular or electromagnetic radiations.

radiopacity radio-opacité the quality or property of obstructing the passage of radiant energy, such as x-rays, the representative areas appearing light or white on the exposed film. Adj.: radiopaque.

radiopathology radiopathologie the pathology of the effects of radiation on tissues.

radiopharmaceutical radiopharmaceutique a radioactive pharmaceutical, nuclide, or other chemical used for diagnostic or therapeutic purposes.

radioprotector radioprotecteur an agent that provides protection against the toxic effects of ionizing radiation.

radioreceptor radiorécepteur 1. a receptor for the stimuli that are excited by radiant energy, such as light or heat. 2. a receptor to which a radioligand can bind.

radioresistance radiorésistance resistance, as of tissue or cells, to irradiation. Adj.: radioresistant.

radioscopy radioscopie fluoroscopy.

radiosensitivity radiosensibilité sensitivity, as of the skin, tumor tissue, etc., to radiant energy, such as x-rays or other radiation. Adj.: radiosensitive.

radiosurgery radiochirurgie surgery in which tissue destruction is performed by means of ionizing radiation rather than by surgical incision. stereotactic r., stereotaxic r. r. stéréotaxique stereotactic surgery in which lesions are produced by ionizing radiation.

radiotherapy radiothérapie treatment of disease by means of ionizing radiation; tissue may be exposed to a beam of radiation, or a radioactive element may be contained in devices (e.g., needles or wire) and inserted directly into the tissues (interstitial r.), or it may be introduced into a natural body cavity (intracavitary r.).

radiotoxemia radiotoxémie toxemia produced by radiant energy.

radiotracer radiotraceur radioactive tracer.

radiotransparent radiotransparent radiolucent.

radiotropic radiotrope influenced by radiation.

radioulnar radiocubital pertaining to the radius and ulna.

radium radium a radioactive element (see Table of Elements), at. no. 88, symbol Ra; it has a half-life of 1622 years, emitting alpha, beta, and gamma radiation. It decays to radon.

radius pl. radii [L.] 1. rayon a line from the center of a circle to a point on its circumference. 2. radius the bone on the outer side of the forearm, articulating proximally with the humerus and ulna and distally with the ulna and carpus. See Plate 1.

radix radix pl. radices [L.] root.

radon radon a gaseous radioactive element (see Table of Elements), at. no. 86, symbol Rn, resulting from decay of radium.

ragocyte ragocyte a polymorphonuclear phagocyte, found in the joints in rheumatoid arthritis, with cytoplasmic inclusions of aggregated IgG, rheumatoid factor, fibrin, and complement.

rajas rajas [Sanskrit] according to ayurveda, one of the three gunas, characterized by activity, stimulation, and movement.

rale râle crackle; a discontinuous sound consisting of a series of short sounds, heard during inhalation. amphoric r. r. amphorique a coarse musical rale due to splashing of fluid in a cavity connected with a bronchus. clicking r. craquement pulmonaire a small sound heard when inhaled air passes through secretions in smaller bronchi. crackling r. crépitation subcrepitant r. crepitant r. r. crépitant a sound like that made by rubbing hairs between the fingers, heard at the end of inhalation. dry r. r. sec a fine sound heard in interstitial lung diseases such as idiopathic pulmonary fibrosis. moist r. r. bulleux a sound heard over fluid in the bronchial tubes. subcrepitant r. r. sous-crépitant a fine moist rale heard over liquid in the smaller tubes.

raloxifene raloxifène a selective activator of estrogen receptors that increases bone mineral density and decreases total and LDL cholesterol without affecting breast and uterine tissue; used as the hydrochloride salt for the prevention of postmenopausal osteoporosis.

Ralstonia Ralstonia a genus of gram-negative, aerobic, rod-shaped bacteria of the family Burkholderiaceae; several species, including R. pickettii, are associated with human infections.

ramal rameux pertaining to a ramus.

ramelteon ramelteon a melatonin receptor agonist used in the treatment of insomnia.

ramification ramification 1. distribution in branches. 2. a branching.

ramify 1. ramifier to branch; to diverge in different directions. 2. ramifier (se) to traverse in branches.

ramipril ramipril an angiotensin-converting enzyme inhibitor used in treatment of hypertension and congestive heart failure and the prevention of a major cardiovascular event in high-risk patients.

ramisection ramisection section of one or more rami communicantes of the sympathetic nervous system.

ramitis ramite inflammation of a ramus.

ramose rameux branching; having many branches.

ramulus ramuscule pl. ramuli [L.] radicle.

ramus rameau pl. rami [L.] a branch, as of a nerve, vein, or artery. r. articularis ramus articularis a branch of a mixed (afferent or efferent) peripheral nerve supplying a joint and its associated structures. r. autonomicus ramus autonomicus any of the branches of the parasympathetic or sympathetic nerves of the autonomic nervous system. r. communicans r. communicant a branch connecting two nerves or two arteries. r. cutaneus ramus cutaneus, r. cutané a branch of a mixed (afferent or efferent) peripheral nerve innervating a region of the skin.

random aléatoire pertaining to a chance-dependent process, particularly one that occurs according to a known probability distribution.

range 1. amplitude the difference between the upper and lower limits of a variable or of a series of values. 2. étendue an interval in which values sampled from a population, or the values in the population itself, are known to lie. r. of motion amplitude articulaire the range, measured in degrees of a circle, through which a joint can be extended and flexed.

ranine 1. batracien pertaining to a frog. 2. ranin ranular. 3. ranin sublingual.

ranitidine ranitidine a histamine H₂ receptor antagonist, used as the hydrochloride salt to inhibit gastric acid secretion in the treatment of gastric and duodenal ulcer, gastroesophageal reflux disease, and conditions that cause gastric hypersecretion.

ranula ranula a cystic tumor beneath the tongue.Adj.: ranular.

rape viol nonconsensual sexual penetration of an individual, obtained by force or threat, or in cases in which the victim is not capable of consent.

raphe raphé pl. raphae a seam; the line of union of the halves of various symmetrical parts. r. of penis r. du pénis a narrow dark streak or ridge continuous posteriorly with the raphe of scrotum and extending forward along the midline on the underside of the penis. perineal r. r. périnéal a ridge along the median line of the perineum that runs forward from the anus; in the male, it is continuous with the raphe of scrotum. r. of scrotum r. du scrotum a ridge along the surface of the scrotum in the median line, continuous with the perineal raphe and the raphe of penis.

rapport rapport a relation of harmony and accord, as between patient and physician.

rarefaction raréfaction condition of being or becoming less dense.

rasayana rasayana any of a group of herbal remedies with antioxidant properties used in ayurveda to promote health, provide defense against disease, and promote longevity.

rash érythème a temporary eruption on the skin. butterfly r. é. en papillon, vespertilio a skin eruption across the nose and adjacent areas of the cheeks in the pattern of a butterfly, as in lupus erythematosus and seborrheic dermatitis. diaper r. é. fessier irritant dermatitis in infants on the areas covered by the diaper, usually due to soiling or fungal contamination. drug r. é. médicamenteux see under eruption. heat r. é. calorique miliaria rubra.

rasp 1. râpe raspatory; a coarse file used in surgery. 2. râper to file with a rasp.

raspatory rugine rasp (1).

RAST RAST radioallergosorbent test.

rate taux, pourcentage the speed or frequency with which an event or circumstance occurs per unit of time, population, or other standard of comparison. basal metabolic r. métabolisme basal an expression of the rate at which oxygen is used by body cells, or the calculated equivalent heat production by the body, in a fasting subject at complete rest. Abbreviated BMR. birth r. t. de natalité the number of births in a specified area during a defined period for the total population, often further qualified as to which portion of the population is being examined. case fatality r. t. de létalité the ratio of the number of deaths caused by a specified disease to the number of diagnosed cases of that disease. circulation r. volume-minute du cœur the amount of blood pumped through the body by the heart per unit time. death r. t. de mortalité an expression of the number of deaths in a population at risk during one year. The crude death r. is the ratio of the number of deaths to the total population of an area; the age-specific death r. is the ratio of the number of deaths in a specific age group to the number of persons in that age group; the cause-specific death r. is the ratio of the number of deaths due to a specified cause to the total population. dose r. débit de dose the amount of any agent administered per unit of time. erythrocyte sedimentation r. (ESR) vitesse de sédimentation globulaire the rate at which erythrocytes sediment from a well-mixed specimen of venous blood, as measured by the distance that the top of a column of erythrocytes falls in a specified time interval under specified conditions. fatality r. t. de mortalité clinique case fatality r. fertility r. t. de fécondité a measure of fertility in a specified population over a specified period of time, particularly the general fertility r., the number of live births in a geographic area in a year per 1000 women of childbearing age. fetal death r. t. de mortinatalité the ratio of the number of fetal deaths in one year to the total number of both live births and fetal deaths in that year. five-year survival r. t. de survie à cinq ans an expression of the number of survivors with no trace of disease five years after each has been diagnosed or treated for the same disease. glomerular filtration r. (GFR) filtration glomérulaire an expression of the quantity of glomerular filtrate formed each minute in the nephrons of both kidneys, usually measured by the rate of clearance of creatinine. growth r. t. de croissance an expression of the increase in size of an organic object per unit of time. heart r. fréquence cardiaque the number of contractions of the cardiac ventricles per unit of time. incidence r. t. d’incidence the probability of developing a particular disease during a given period of time; the numerator is the number of new cases during the specified time period and the denominator is the population at risk during the period. morbidity r. t. de morbidité an inexact term that can mean either the incidence rate or the prevalence rate. mortality r. t. de mortalité death r. prevalence r. t. de prévalence the number of people in a population who have a disease at a given time: the numerator is the number of existing cases of disease at a specified time and the denominator is the total population. pulse r. fréquence du pouls the number of pulsations noted in a peripheral artery per unit of time. respiration r. fréquence de la respiration the number of movements of the chest wall per unit of time, indicative of inhalation and exhalation. sedimentation r. vitesse de sédimentation the rate at which a sediment is deposited in a given volume of solution, especially when subjected to the action of a centrifuge. stillbirth r. t. de mortinatalité fetal death r.

ratio quotient [L.] an expression of the quantity of one substance or entity in relation to that of another; the relationship between two quantities expressed as the quotient of one divided by the other. A-G r., albumin-globulin r. rapport albumine, globuline the ratio of albumin to globulin in blood serum, plasma, or urine in various renal diseases. cardiothoracic r. rapport cardiothoracique on a radiograph, the ratio of the transverse diameter of the heart to the internal diameter of the chest at its widest point just above the dome of the diaphragm. lecithin/sphingomyelin r., L/S r. rapport lécithine/sphingomyéline the ratio of lecithin to sphingomyelin concentration in the amniotic fluid, used to predict the degree of pulmonary maturity of the fetus and thus the risk of respiratory distress syndrome (RDS) if the fetus is delivered prematurely. sex r. t. de masculinité the proportion of one sex to another, traditionally the number of males in a population per number of females. ventilation-perfusion r. rapport ventilation-perfusion the ratio of oxygen received in the pulmonary alveoli to the flow of blood through the alveolar capillaries.

rational rationnel based upon reason; characterized by possession of one’s reason.

rationalization rationalisation an unconscious defense mechanism by which one justifies attitudes and behavior that would otherwise be unacceptable.

rattlesnake serpent à sonnette any of the New World pit vipers of the genera Crotalus and Sistrurus, having a series of cornified interlocking segments at the tip of the tail; when disturbed they vibrate the tail to produce the characteristic rattling or buzzing sound. Included are the massasauga, the eastern diamondback r. (C. adamanteus), the Mojave r. (C. scutulatus scutulatus), the prairie r. (C. viridis viridis), the pygmy r. (S. miliarius), the timber r. (C. horridus),and the western diamondback r. (C. atrox).

Rauwolfia Rauwolfia a genus of tropical trees and shrubs, including R. serpentina and over 100 other species, that provide numerous alkaloids, notably reserpine, of medical interest.

rauwolfia rauwolfia 1. any member of the genus Rauwolfia. 2. the dried root of Rauwolfia, or an extract of it. r. serpentina r. serpentina the dried root of Rauwolfia serpentina; used as an antihypertensive; also used in folk medicine and Indian medicine.

RAV RAV Rous-associated virus.

ray rayon 1. a line emanating from a center. 2. rayon, rayonnement a more or less distinct portion of radiant energy (light or heat), proceeding in a specific direction. 3. a distinct portion of electromagnetic radiation that proceeds in a specific direction α-r’s r α high-speed helium nuclei ejected from radioactive substances; they have less penetrating power than beta rays. actinic r’s rayons actiniques light rays that produce chemical action, especially those beyond the violet end of the spectrum. alpha r’s rayon alpha α-ρ σ. β-r’s beta r’s rayons β electrons ejected from radioactive substances with velocities as high as 0.98 of the velocity of light; they have more penetrating power than alpha rays, but less than gamma rays. digital r. crête digitale 1. a digit of the hand or foot and the corresponding portion of the metacarpus or metatarsus, considered as a continuous structural unit. 2. in the embryo, a mesenchymal condensation of the hand or foot plate that outlines the pattern of a future digit. γ-r’s, gamma r’s rayons γ electromagnetic radiation of short wavelengths emitted by an atomic nucleus during a nuclear reaction, consisting of high-energy photons, having no mass and no electric charge, and traveling with the speed of light and with great penetrating power. grenz r’s rayons de Grenz very soft x-rays having wavelengths about 20 nm, lying between x-rays and ultraviolet rays. infrared r’s rayons infrarouges radiations just beyond the red end of the visible spectrum, having wavelengths of 0.75-1000 μm; see also infrared. medullary r’s rayons médullaires the intracortical prolongations of the renal pyramids. roentgen r’s r. de Röntgen x-r’s. ultraviolet r’s rayonnement ultraviolet those invisible rays of the spectrum that are beyond the violet rays; their wavelengths range between 4 and 400 nm; see ultraviolet. x-r’s rayons X electromagnetic vibrations of short wavelengths (about 0.01 to 10 nm), or corresponding quanta produced when electrons moving at high velocity impinge on various substances; they are able to penetrate most substances to some extent, to affect a photographic plate, to cause certain substances to fluoresce, and to strongly ionize tissue.

Rb Rb rubidium.

RBBB BBD right bundle branch block; see bundle branch block, under block.

RBC GR red blood cell.

RBE EBR relative biological effectiveness.

rcp rcp reciprocal translocation.

Re Re rhenium.

re- re- word element [L.], back; again; contrary, etc.

reabsorption réabsorption 1. the act or process of absorbing again, as the absorption by the kidneys of substances (glucose, proteins, sodium, etc.) already secreted into the renal tubules. 2. resorption.

reactant réactif a substance entering into a chemical reaction.

reaction réaction 1. opposite action, or counterreaction; the response to stimuli. 2. a phenomenon caused by the action of chemical agents; a chemical process in which one substance is transformed into another substance or other substances. 3. the mental and/or emotional state that develops in any particular situation. acrosome r. r. acrosomiale structural changes and liberation of acrosomal enzymes occurring in spermatozoa in the vicinity of an oocyte, facilitating entry into the oocyte. alarm r. r. d’alarme the physiologic effects (increase in blood pressure, cardiac output, blood flow to skeletal muscles, rate of glycolysis, and blood glucose concentration; decrease in blood flow to viscera) mediated by sympathetic nervous system discharge and release of adrenal medullary hormones in response to stress, fright, or rage. allergic r. r. allergique hypersensitivity r., sometimes specifically a type I hypersensitivity reaction. anaphylactic r. r. anaphylactique anaphylaxis. anaphylactoid r. r. anaphylactoïde one resembling generalized anaphylaxis but not caused by IgE-mediated allergic reaction. antibody-mediated hypersensitivity r. r. immunitaire de type II 1. type II hypersensitivity r.; see Gell and Coombs classification, under classification. 2. occasionally, any hypersensitivity reaction in which antibodies are the primary mediators, i.e., types I-III. antigen-antibody r. r. antigène-anticorps the reversible binding of antigen to homologous antibody by the formation of weak bonds between antigenic determinants on antigen molecules and antigen binding sites on immunoglobulin molecules. anxiety r. névrose d’angoisse a reaction characterized by abnormal apprehension or uneasiness; see also anxiety disorders, under disorder. Arias-Stella r. phénomène d’Arias-Stella nuclear and cellular hypertrophy of the endometrial epithelium, associated with ectopic pregnancy. Arthus r. p. d’Arthus the development of an inflammatory lesion, with induration, erythema, edema, hemorrhage, and necrosis, a few hours after intradermal injection of antigen into a previously sensitized animal producing precipitating antibody; it is classed as a type III hypersensitivity reaction. biuret r. r. au biuret formation of a chelate having a violet-red color when biuret or compounds having two or more adjacent peptide bonds (e.g., proteins) are reacted with copper sulfate in alkaline solution; used as the basis of a colorimetric method for detection of protein. cell-mediated hypersensitivity r. r. immunitaire de type IV type IV hypersensitivity r.; see Gell and Coombs classification, under classification. conversion r. r. de conversion see under disorder. cross r. r. croisée the interaction of an antigen with an antibody formed against a different antigen with which the first antigen shares identical or closely related antigenic determinants. cytotoxic hypersensitivity r. r. d’hypersensibilité cytotoxique type II hypersensitivity r.; see Gell and Coombs classification, under classification. defense r. r. de défense see under mechanism. delayed hypersensitivity r., delayed-type hypersensitivity r. r. d’hypersensibilité retardée that taking 24 to 72 hours to develop and mediated by T lymphocytes rather than by antibodies; usually denoting the subset of type IV hypersensitivity reactions involving cytokine release and macrophage activation, as opposed to direct cytolysis, but sometimes used more broadly, even as a synonym for type IV hypersensitivity r. (see Gell and Coombs classification, under classification). r. of degeneration r. de dégénérescence the reaction to electrical stimulation of muscles whose nerves have degenerated, consisting of loss of response to a faradic stimulation in a muscle, and to galvanic and faradic stimulation in the nerve. foreign body r. r. à un corps étranger a granulomatous inflammatory reaction evoked by the presence of exogenous material in the tissues, characterized by the formation of foreign body giant cells. hemiopic pupillary r. r. hémiopique de Wernicke in certain cases of hemianopia, light thrown upon one side of the retina causes the iris to contract, while light thrown upon the other side arouses no response. hypersensitivity r. r. d’hypersensibilité one in which the body mounts an exaggerated or inappropriate immune response to a substance perceived as foreign, resulting in local or general tissue damage. Such reactions are usually classified as types I-IV on the basis of the Gell and Coombs classification (q.v.). id r. r. seconde a secondary skin eruption occurring in sensitized patients as a result of circulation of allergenic products from a primary site of infection. immediate hypersensitivity r. r. d’hypersensibilité immédiate 1. type I hypersensitivity r.; see Gell and Coombs classification, under classification. 2. occasionally, any hypersensitivity reaction mediated by antibodies and developing rapidly, generally in minutes to hours (i.e., types I-III), as distinguished from those mediated by T lymphocytes and macrophages and requiring days to develop (type IV, or delayed hypersensitivity r.). immune r. r. immunitaire see under response. immune complex-mediated hypersensitivity r. r. immunitaire de type III type III hypersensitivity r.; see Gell and Coombs classification, under classification. Jarisch-Herxheimer r. r. de Jarisch-Herxheimer a transient immunologic reaction following antibiotic treatment of syphilis and certain other diseases, marked by fever, chills, headache, myalgia, and exacerbation of cutaneous lesions, probably due to release of toxic or antigenic substances by the infecting microorganisms. Jones-Mote r. r. de Jones-Mote a mild skin reaction of the delayed (type IV) hypersensitivity type occurring after challenge with protein antigens. late phase r. phase tardive de la réponse aux IgE an IgE-mediated immune reaction occurring 5 to 8 hours after exposure to antigen, after the wheal and flare reactions of immediate hypersensitivity have diminished, with inflammation peaking around 24 hours, and then subsiding. lengthening r. r. d’allongement reflex elongation of the extensor muscles which permits flexion of a limb. lepra r. r. lépreuse an acute or subacute hypersensitivity reaction occurring either during the course of antileprosy treatment or in untreated cases of leprosy. leukemoid r. r. leucémoïde a peripheral blood picture resembling that of leukemia or indistinguishable from it on the basis of morphologic appearance alone; seen in certain infectious diseases, inflammatory conditions, and intoxications. Neufeld r. r. de Neufeld swelling of the capsules of pneumococci, seen under the microscope, on mixture with specific immune serum, owing to the binding of antibody with the capsular polysaccharide. oxidation-reduction r. r. d’oxydoréduction redox r. Pirquet r. cutiréaction de Von Pirquet appearance of a papule with a red areola 24 to 48 hours after introduction of two small drops of Old tuberculin by slight scarification of the skin; a positive test indicates previous infection. polymerase chain r. (PCR) amplification en chaîne par polymérase génique a rapid technique for in vitro amplification of specific DNA or RNA sequences, allowing small quantities of short sequences to be analyzed without cloning. precipitin r. séroprécipitation the formation of an insoluble precipitate by reaction of antigen and antibody. redox r. oxydoréduction a reaction oxidizing one substrate while reducing another. righting r’s r. de redressement responses of the head and eyes that occur as the body processes sensory input from the visual and vestibular systems. serum r. sérodiagnostic seroreaction. startle r. r. d’alarme the various psychophysiological phenomena, including involuntary motor and autonomic reactions, evidenced by an individual in reaction to a sudden, unexpected stimulus, as a loud noise. stress r. stress any physiological or psychological reaction to physical, mental, or emotional stress that disturbs the organism’s homeostasis. substitution r. r. de substitution a chemical reaction in which one atom or functional group replaces another in a molecule. T cell-mediated hypersensitivity r. r. d’hypersensibilité retardée à médiation cellulaire type IV hypersensitivity r.; see Gell and Coombs classification, under classification. Weil-Felix r. r. de Weil-Félix agglutination by blood serum of typhus patients of a bacillus of the proteus group from the urine and feces. Wernicke r. r. hémiopique de Wernicke hemiopic pupillary r. wheal and erythema r., wheal and flare r. r. papuloérythémateuse a cutaneous sensitivity reaction to skin injury or administration of antigen, due to histamine production and marked by edematous elevation and erythematous flare.

reaction-formation formation réactionnelle an unconscious defense mechanism in which a person assumes an attitude that is the reverse of the wish or impulse actually harbored.

reactive réactif characterized by reaction; readily responsive to a stimulus.

reading lecture understanding of written or printed symbols representing words. lip r., speech r. l. sur les lèvres understanding of speech through observation of the speaker’s lip movements.

reagent réactif a substance used to produce a chemical reaction so as to detect, measure, produce, etc., other substances.

reagin réagine the antibody that mediates immediate hypersensitivity reactions; in humans, IgE. Adj.: reaginic.

reamer alésoir an instrument used in dentistry for enlarging root canals.

rebound rebond a reversed response occurring upon withdrawal of a stimulus. acid r. hyperacidité réflexe an increased rate of stomach acid secretion occurring soon after eating. heparin r. r. héparinique the return of anticoagulant activity following neutralization of heparin in a patient’s blood by protamine. urea r. r. urique a sudden increase in release of urea into the bloodstream by cells and organs that normally store it, seen in the first 15 minutes to an hour after urea has been removed by dialysis.

recanalization recanalisation formation of new canals or paths, especially blood vessels, through an obstruction such as a clot.

receptaculum receptaculum pl. receptacula [L.] a vessel or receptacle. r. chyli citernes terminales cisterna chyli.

receptive réceptif capable of receiving or of responding to a stimulus.

receptor récepteur 1. a molecule on the surface or within a cell that recognizes and binds with specific molecules, producing a specific effect in the cell; e.g., the cell-surface receptors for antigens or cytoplasmic receptors for steroid hormones. 2. a sensory nerve ending that responds to various stimuli. α-adrenergic r’s r. α-adrénergiques adrenergic receptors that respond to norepinephrine and to such blocking agents as phenoxybenzamine. They are subdivided into two types: α₁, found in smooth muscle, heart, and liver, with effects including vasoconstriction, intestinal relaxation, uterine contraction and pupillary dilation, and α₂, found in platelets, vascular smooth muscle, nerve termini, and pancreatic islets, with effects including platelet aggregation, vasoconstriction, and inhibition of norepinephrine release and of insulin secretion. adrenergic r. r. adrénergique receptors for epinephrine or norepinephrine, such as those on effector organs innervated by postganglionic adrenergic fibers of the sympathetic nervous system. Classified as α-adrenergic r’s and β-adrenergic r’s. alphaadrenergic r’s r. α-adrénergiques α-adrenergic r’s. β-adrenergic r’s, beta-adrenergic r’s r. β-adrénergiques adrenergic receptors that respond particularly to epinephrine and to such blocking agents as propranolol. They are subdivided into two basic types: β₁, in myocardium and causing lipolysis and cardiac stimulation, and β₂, in smooth and skeletal muscle and liver and causing bronchodilation and vasodilation. The atypical type β₃ may be involved in lipolysis regulation in adipose tissue. cholinergic r’s r. cholinergiques cell-surface receptor molecules that bind the neurotransmitter acetylcholine and mediate its action on postjunctional cells. complement r’s r. du complément cell-surface receptors for products of complement reactions, playing roles including recognition of pathogens, phagocytosis, adhesion, and clearance of immune complexes. The best characterized are C1-C4, which bind C3 fragments already bound to a surface. cutaneous r. r. cutané any of the various types of sense organs found in the dermis or epidermis, usually a mechanoreceptor, thermoreceptor, or nociceptor. cytokine r’s r. cytokiniques membrane-spanning proteins that bind cytokines via extracellular domains, acting to convert an extracellular signal to an intracellular one. G protein-coupled r’s r. couplés aux protéines G a large superfamily of membrane receptors, specific for a wide range of signals, whose intracellular effects are mediated by G proteins. H₁ r’s, H₂ r’s r. H₁ see histamine. joint r. r. articulaire any of several mechanoreceptors that occur in joint capsules and respond to deep pressure and to other stimuli such as stress or change in position. muscarinic r. r. muscarinique cholinergic receptors that are stimulated by the alkaloid muscarine and blocked by atropine; they are found on automatic effector cells and on central neurons in the thalamus and cerebral cortex. muscle r. r. musculaire a mechanoreceptor found in a muscle or tendon. nicotinic r. r. nicotinique cholinergic receptors that are stimulated initially and blocked at high doses by the alkaloid nicotine and blocked by tubocurarine; they are found on automatic ganglion cells, on striated muscle cells, and on spinal central neurons. nonadapting r. r. à adaptation nulle a mechanoreceptor, such as a nociceptor, that responds to stimulation with a continual steady discharge and little or no accommodation over time. olfactory r. r. olfactif a chemoreceptor in the nasal epithelium that is sensitive to stimulation, giving rise to the sensation of odors. opiate r., opioid r. r. opiacé any of a number of receptors for opiates and opioids, grouped into at least seven types on the basis of their substrates and physiological effects. orphan r. r. orphelin a protein identified as a putative receptor on the basis of its structure but without identification of possible ligands or evidence of function. pain r. r. nociceptif nociceptor. purinergic r’s r. purinergiques membrane receptors widely expressed in the brain, peripheral tissues, and circulating blood cells, that bind purine bases or nucleotides. Most mediate their responses by G proteins. rapidly adapting r. r. à adaptation rapide a mechanoreceptor that responds quickly to stimulation but that rapidly accommodates and stops firing if the stimulus remains constant. sensory r. r. sensoriel receptor (2). slowly adapting r. r. à adaptation lente a mechanoreceptor that responds slowly to stimulation and continues firing as long as the stimulus continues. stretch r. mécanorécepteur a sense organ in a muscle or tendon that responds to elongation. tactile r. r. tactile a mechanoreceptor for the sense of touch. thermal r. r. thermique thermoreceptor.

recess récessus a small empty space, hollow, or cavity. epitympanic r. r. épitympanique attic or epitympanum; the upper part of the tympanic cavity, above the level of the tympanic membrane, containing part of the incus and malleus. infundibuliform r. r. infundibuliforme pharyngeal r. laryngopharyngeal r. gouttière laryngopharyngée piriform r. pharyngeal r. r. pharyngé latéral a wide, slitlike lateral extension in the wall of the nasopharynx, cranial and dorsal to the pharyngeal orifice of the auditory tube. piriform r. sinus piriforme a pear-shaped fossa in the wall) of the laryngeal pharynx. pleural r’s cul-de-sacs pleuraux the spaces where the different portions of the pleura join at an angle and which are never completely filled by lung tissue. r. of Rosenmüller fossette de Rosenmüller pharyngeal r. sphenoethmoidal r. r. sphénoethmoïdal, ethmoïdosphénoïdal the most superior and posterior part of the nasal cavity, above the superior nasal concha, into which the sphenoidal sinus opens. subpopliteal r. bourse séreuse du poplité, r. subpoplité a prolongation of the synovial tendon sheath of the popliteus muscle outside the knee joint into the popliteal space. superior r. of tympanic membrane poche tympanique supérieure, supérieur de la membrane tympanique Prussak pouch. utricular r. fossette utriculaire utricle (2).

recessive 1. fuyant tending to recede. 2. récessif in genetics, pertaining to phenotypic expression of an allele only in homozygotes (or hemizygotes, for X-linked traits).

recessus récessus pl. recessus [L.] a recess.

recidivation récidive relapse, recurrence, or repetition, as of a disease or condition or of a pattern of behavior, particularly a criminal act.

recidivism récidivité, récidivisme a tendency to relapse, particularly a return to criminal behavior.

recipe [L.] 1. recipe take; used at the head of a prescription, indicated by the symbol R∕. 2. recette a formula for the preparation of a specific combination of ingredients.

recipient receveur one who receives, as a blood transfusion, or a tissue or organ graft. universal r. r. universel a person thought to be able to receive blood of any group without agglutination of the donor cells.

reciprocal réciproque 1. being equivalent or complementary. 2. inversely related; opposing.

reciprocation 1. réciprocité the act of giving and receiving in exchange; the complementary interaction of two distinct entities. 2. mouvement alternatif, mouvement de va-et-vient an alternating back-and-forth movement.

recognition reconnaissance in immunology, the interaction of immunologically competent cells with antigen, involving antigen binding to a specific receptor on the cell surface and resulting in an immune response.

recoil recul a quick pulling back. elastic r. r. élastique the ability of a stretched object or organ, such as the bladder or lung, to return to its resting position.

recombinant recombinant 1. the new entity (e.g., gene, protein, cell, individual) that results from genetic recombination. 2. pertaining or relating to such an entity.

recombination recombinaison 1. the reunion, in the same or different arrangement, of formerly united elements that have been separated. 2. in genetics, the process that creates new combinations of genes by shuffling the linear order of the DNA.

recompression recompression return to normal environmental pressure after exposure to greatly diminished pressure.

reconstruction reconstruction 1. the reassembling or re-forming of something from constituent parts. 2. surgical restoration of function of a body part.

record 1. rapport a permanent or long-lasting account of something (as on film, in writing, etc.). 2. enregistrement in dentistry, a registration. problem-oriented r. (POR) méthode de Weed a method of patient care record keeping that focuses on specific health care problems and a cooperative health care plan designed to cope with the identified problems. The components of the POR are: data base, which contains information required for each patient regardless of diagnosis or presenting problems; problem list, which contains the major problems currently needing attention; plan, which specifies what is to be done with regard to each problem; progress notes, which document the observations, assessments, nursing care plans, physician’s orders, etc., of all health care personnel directly involved in the care of the patient. See also SOAP.

recrement récrément saliva, or other secretion, which is reabsorbed into the blood. Adj.: recrementitious.

recrudescence recrudescence recurrence of symptoms after temporary abatement. Adj.: recrudescent.

recruitment recrutement 1. the gradual increase to a maximum in a reflex when a stimulus of unaltered intensity is prolonged. 2. in audiology, an abnormally rapid increase in the loudness of a sound caused by a slight increase in its intensity. 3. the orderly increase in number of activated motor units with increasing strength of voluntary muscle contractions. 4. the process by which certain primordial ovarian follicles begin growing in a particular menstrual cycle.

rectal rectal pertaining to the rectum.

rectectomy rectectomie proctectomy.

rectification rectification 1. the act of making straight, pure, or correct. 2. redistillation of a liquid to purify it.

rectitis rectite proctitis.

rect(o)- rect(o)- word element [L.], rectum. See also words beginning proct(o)-.

rectoabdominal rectoabdominal pertaining to the rectum and abdomen.

rectocele rectocèle hernial protrusion of part of the rectum into the vagina.

rectocolitis rectocolite proctocolitis.

rectocutaneous rectocutané pertaining to the rectum and the skin.

rectolabial rectolabial relating to the rectum and a labium majus.

rectopexy rectopexie proctopexy.

rectoplasty rectoplastie proctoplasty.

rectoscope rectoscope proctoscope.

rectosigmoid rectosigmoïde the terminal portion of the sigmoid colon and the proximal portion of the rectum.

rectosigmoidectomy rectosigmoïdectomie excision of the rectosigmoid.

rectostomy rectostomie proctostomy.

rectourethral recto-urétral pertaining to or communicating with the rectum and urethra.

rectouterine recto-utérin pertaining to the rectum and uterus.

rectovaginal rectovaginal pertaining to or communicating with the rectum and vagina.

rectovesical rectovésical pertaining to or communicating with the rectum and bladder.

rectum rectum the distal portion of the large intestine.

rectus rectus [L.] straight.

recumbent alité lying down.

recuperation récupération recovery of health and strength.

recurrence récurrence the return of symptoms after a remission. Adj.: recurrent.

recurrent récurrent [L. recurrens returning] 1. running back, or toward the source. 2. returning after remissions.

recurvation recourbure a backward bending or curvature.

red rouge 1. the color produced by the longest waves of the visible spectrum, approximately 630 to 750 nm. 2. a dye or stain with this color. scarlet r. r. écarlate, écarlate de Briebich an azo dye used as a biological stain for fats.

redia rédie pl. rediae a larval stage of certain trematode parasites, which develops in the body of a snail host and gives rise to daughter rediae or to the cercariae.

redintegration rédintégration 1. the restoration or repair of a lost or damaged part. 2. a psychic process in which part of a complex stimulus provokes the complete reaction that was previously made only to the complex stimulus as a whole. 3. reintegration (2).

redox redox oxidation-reduction.

reduce réduire 1. to restore to the normal place or relation of parts, as to reduce a fracture. 2. réduire (se) to undergo reduction. 3. to decrease in weight or size.

reducible réductible capable of being reduced.

reductant réducteur the electron donor in an oxidation-reduction (redox) reaction.

reductase réductase a term used in the names of some of the oxidoreductases, usually specifically those catalyzing reactions important solely for reduction of a metabolite. 5α-r. r. 5α an enzyme that catalyzes the irreversible reduction of testosterone to dihydrotestosterone; enzyme deficiency leads to a form of male pseudohermaphroditism.

reduction réduction 1. the correction of a fracture, luxation, or hernia. 2. the addition of hydrogen to a substance, or more generally, the gain of electrons. closed r. r. orthopédique the manipulative reduction of a fracture without incision. open r. r. sanglante reduction of a fracture after incision into the fracture site.

reduplication 1. réduplication, redoublement, dédoublement a doubling back. 2. réduplication the recurrence of paroxysms of a double type. 3. réduplication duplication (3).

reentry réentrée reexcitation of a region of cardiac tissue by a single impulse, continuing for one or more cycles and sometimes resulting in ectopic beats or tachyarrhythmias; it also requires refractoriness of the tissue to stimulation and an area of unidirectional block to conduction. Adj.: reentrant.

refeeding réalimentation restoration of normal nutrition after a period of fasting or starvation.

referred référé, irradié, projeté of sensory phenomena, perceived at a site other than the one being stimulated.

reflection réflexion 1. a turning or bending back upon a course. 2. reflet, an image produced by reflection. 3. reflet, répercussion in physics, the turning back of a ray of light, sound, or heat when it strikes against a surface that it does not penetrate. 4. a special form of reentry in which an impulse crosses an area of diminished responsiveness to excite distal tissue then returns, retracing its path rather than traversing a circuit, to seesaw back and forth.

reflex réflexe a reflected action or movement; the sum total of any particular automatic response mediated by the nervous system. abdominal r’s r. abdominaux contractions of the abdominal muscles on stimulation of the abdominal skin. accommodation r. r. d’accommodation the coordinated changes that occur when the eye adapts itself to near vision; constriction of the pupil, convergence of the eyes, and increased convexity of the lens. Achilles tendon r. r. achilléen triceps surae r. acoustic r. r. acoustique contraction of the stapedius muscle in response to intense sound. anal r. r. anal contraction of the anal sphincter on irritation of the anal skin. ankle r. r. achilléen triceps surae r. auditory r. r. auditif any reflex caused by stimulation of the vestibulocochlear nerve, especially momentary closure of both eyes produced by a sudden sound. Babinski r. r. de Babinski dorsiflexion of the big toe on stimulation of the sole, occurring in lesions of the pyramidal tract, although a normal reflex in infants. Babkin r. r. de Babkin pressure by the examiner’s thumbs on the palms of both hands of the infant results in opening of the infant’s mouth. baroreceptor r. baroréflexe, r. barorécepteur the reflex response to stimulation of baroreceptors of the carotid sinus and aortic arch, regulating blood pressure by controlling heart rate, strength of heart contractions, and diameter of blood vessels. Bezold r., Bezold-Jarisch r. r. de Bezold reflex bradycardia and hypotension resulting from stimulation of cardiac chemoreceptors by antihypertensive alkaloids and similar substances. biceps r. r. bicipital contraction of the biceps muscle when its tendon is tapped. Brain r. r. de Brain extension of a hemiplegic flexed arm on assumption of a quadrupedal posture. brainstem r’s r. du tronc cérébral those regulated at the level of the brainstem, such as pupillary, pharyngeal, and cough reflexes, and the control of respiration; their absence is one criterion of brain death. bulbospongiosus r. r. bulbocaverneux contraction of the bulbospongiosus muscle in response to a tap on the dorsum of the penis. carotid sinus r. r. sinucarotidien slowing of the heart beat on pressure on the carotid artery at the level of the cricoid cartilage. Chaddock r. r. de Chaddock in lesions of the pyramidal tract, stimulation below the external malleolus causes extension of the great toe. chain r. c. de réflexes a series of reflexes, each serving as a stimulus to the next one, representing a complete activity. ciliary r. r. ciliaire the movement of the pupil in accommodation. ciliospinal r. r. ciliospinal dilation of the ipsilateral pupil on painful stimulation of the skin at the side of the neck. closed loop r. boucle fermée a reflex, such as a stretch reflex, in which the stimulus decreases when it receives feedback from the response mechanism. conditioned r. r. conditionné see under response. conjunctival r. r. conjonctival closure of the eyelid when the conjunctiva is touched. corneal r. r. cornéen closure of the lids on irritation of the cornea. cough r. r. laryngé the events initiated by the sensitivity of the lining of the airways and mediated by the medulla as a consequence of impulses transmitted by the vagus nerve, resulting in coughing. cremasteric r. r. crémastérien stimulation of the skin on the front and inner thigh retracts the testis on the same side. deep r. r. profond tendon r. digital r. r. digital Hoffmann sign (2). diving r. r. de plongée a reflex involving cardiovascular and metabolic adaptations to conserve oxygen occurring in animals during diving into water; observed in reptiles, birds, and mammals, including humans. doll’s eye r. phénomène des « yeux de poupée» oculocephalic r. elbow r. r. tricipital triceps r. embrace r. r. d’embrassement Moro r. finger-thumb r. s. de Hoffman opposition and adduction of the thumb combined with flexion at the metacarpophalangeal joint and extension at the interphalangeal joint on downward pressure of the index finger. gag r. r. nauséeux pharyngeal r. gastrocolic r. r. gastrocolique increase in intestinal peristalsis after food enters the empty stomach. gastroileal r. r. gastro-iléal increase in ileal motility and opening of the ileocecal orifice when food enters the empty stomach. grasp r. r. de préhension flexion or clenching of the fingers or toes on stimulation of the palm or sole, normal only in infancy. Hering-Breuer r. r. de Hering-Breuer the reflex that limits excessive expansion and contraction of the chest during respiration prior to sending impulses to the brain via the vagus nerve. Hoffmann r. signe de Hoffmann see under sign (2). hypogastric r. r. hypogastrique contraction of the muscles of the lower abdomen on stroking the skin on the inner surface of the thigh. jaw r., jaw jerk r. r. massétérin closure of the mouth caused by a downward blow on the passively hanging chin; rarely seen in health but very noticeable in corticospinal tract lesions. knee jerk r. r. patellaire patellar r. light r. reflet, répercussion 1. réflexe à la lumière cone of light. 2. r. pupillaire contraction of the pupil when light falls on the eye. 3. reflet maculaire a spot of light seen reflected from the retina with the retinoscopic mirror. Magnus and de Kleijn neck r’s r. de Magnus et de Kleijn extension of both ipsilateral limbs, or one, or part of a limb, increase of tonus on the side to which the chin is turned when the head is rotated to the side, and flexion with loss of tonus on the side to which the occiput points; sign of decerebrate rigidity except in infants. Mayer r. r. de Mayer finger-thumb r. Mendel-Bekhterev r. r. de Mendel-Bechterev, r. de Bechterew-Mendel dorsal flexion of the second to fifth toes on percussion of the dorsum of the foot; in certain organic nervous disorders, plantar flexion occurs. micturition r. r. de miction any of the reflexes necessary for effortless urination and subconscious maintenance of continence. Moro r. r. de Moro flexion of an infant’s thighs and knees, fanning and then clenching of fingers, with arms first thrown outward and then brought together as though embracing something; produced by a sudden stimulus and seen normally in the newborn. myotatic r. r. myotatique stretch r. neck r’s r. nucaux reflex adjustments in trunk posture and limb position caused by stimulation of proprioceptors in the neck joints and muscles when the head is turned, tending to maintain a constant orientation between the head and body. neck righting r. r. de redressement nucaux rotation of the trunk in the direction in which the head of the supine infant is turned; absent or decreased in infants with spasticity. nociceptive r’s r. nociceptifs reflexes initiated by painful stimuli. oculocardiac r. r. oculocardiaque a slowing of the rhythm of the heart following compression of the eyes; slowing of from 5 to 13 beats per minute is normal. oculocephalic r. r. oculocéphalique when the head is rotated laterally, the eyes deviate synergistically in the opposite direction; assessed in premature infants and coma to test oculomotor nerve and brainstem function. open loop r. boucle ouverte a reflex in which the stimulus causes activity that it does not further control and from which it does not receive feedback. Oppenheim r. r. d’Oppenheim dorsiflexion of the big toe on stroking downward along the medial side of the tibia, seen in pyramidal tract disease. orbicularis oculi r. r. orbiculo-oculaire normal contraction of the orbicularis oculi muscle, with resultant closing of the eye, on percussion at the outer aspect of the supraorbital ridge, over the glabella, or around the margin of the orbit. orbicularis pupillary r. r. orbiculopupillaire unilateral contraction of the pupil followed by dilatation after closure or attempted closure of eyelids that are forcibly held apart. palatal r., palatine r. r. palatin stimulation of the palate causes swallowing. patellar r. r. rotulien contraction of the quadriceps and extension of the leg when the patellar ligament is tapped. peristaltic r. r. péristaltique when a portion of the intestine is distended or irritated, the area just proximal contracts and the area just distal relaxes. pharyngeal r. r. pharyngé contraction of the pharyngeal constrictor muscle elicited by touching the back of the pharynx. pilomotor r. r. pilomoteur the production of goose flesh on stroking the skin. placing r. r. d’enjambement flexion followed by extension of the leg when the infant is held erect and the dorsum of the foot is drawn along the under edge of a table top; it is obtainable in the normal infant up to the age of six weeks. plantar r. r. plantaire irritation of the sole contracts the toes. proprioceptive r. r. proprioceptif one initiated by a stimulus to a proprioceptor. pupillary r. r. pupillaire 1. contraction of the pupil on exposure of the retina to light. 2. any reflex involving the iris, resulting in change in the size of the pupil, occurring in response to various stimuli, e.g., change in illumination or point of fixation, sudden loud noise, or emotional stimulation. quadriceps r. r. quadricipital patellar r. quadrupedal extensor r. r. de Brain Brain r. red r. reflet rétinien a luminous red appearance seen upon the retina in retinoscopy. righting r. r. de redressement the ability to assume an optimal position when there has been a departure from it. Rossolimo r. r. de Rossolimo in pyramidal tract lesions, plantar flexion of the toes on tapping their plantar surface. scratch r. r. de grattement a spinal reflex by which an itch or other irritation of the skin causes a nearby body part to move over and briskly rub the affected area. spinal r. r. médullaire, r. spinal any reflex action mediated through a center of the spinal cord. startle r. r. de tressaillement Moro r. stepping r. r. de la marche automatique movements of progression elicited when the infant is held upright and inclined forward with the soles of the feet touching a flat surface. stretch r.r. médullaire, r. proprioceptif reflex contraction of a muscle in response to passive longitudinal stretching. sucking r. r. de succion sucking movements of the lips of an infant elicited by touching the lips or the skin near the mouth. superficial r. r. superficiel any withdrawal reflex elicited by noxious or tactile stimulation of the skin, cornea, or mucous membrane, including the corneal reflex, pharyngeal reflex, cremasteric reflex, etc. swallowing r. r. de déglutition palatal r. tendon r. r. tendineux one elicited by a sharp tap on the appropriate tendon or muscle to induce brief stretch of the muscle, followed by contraction. tonic neck r. r. tonique du cou extensions of the arm and sometimes of the leg on the side to which the head is forcibly turned, with flexion of the contralateral limbs; seen normally in the newborn. triceps r. r. tricipital contraction of the belly of the triceps muscle and slight extension of the arm when the tendon of the muscle is tapped directly, with the arm flexed and fully supported and relaxed. triceps surae r. r. achilléen plantar flexion caused by a twitchlike contraction of the triceps surae muscle, elicited by a tap on the Achilles tendon, preferably while the patient kneels on a bed or chair, the feet hanging free over the edge. vestibular r’s r. vestibulaires the reflexes for maintaining the position of the eyes and body in relation to changes in orientation of the head. vestibuloocular r. r. vestibulo-oculaire nystagmus or deviation of the eyes in response to stimulation of the vestibular system by angular acceleration or deceleration or when the caloric test is performed. withdrawal r. r. de défense a nociceptive reflex in which a body part is quickly moved away from a painful stimulus.

reflexogenic réflexogène producing or increasing reflex action.

reflexogenous réflexogène reflexogenic.

reflexograph réflexographe an instrument for recording a reflex.

reflexology réflexologie 1. the science or study of reflexes. 2. a therapeutic technique based on the premise that areas in the hands or feet correspond to the organs and systems of the body and stimulation of these areas by pressure can affect the corresponding organ or system.

reflexometer réflexomètre an instrument for measuring the force required to produce myotatic contraction.

reflux reflux a backward or return flow. duodenogastric r. r. duodénogastrique reflux of the contents of the duodenum into the stomach; it may occur normally, especially during fasting. gastroesophageal r. r. gastro œsophagien reflux of the stomach and duodenal contents into the esophagus. hepatojugular r. r. hépatojugulaire distention of the jugular vein induced by applying manual pressure over the liver; it suggests insufficiency of the right heart. intrarenal r. r. intrarénal reflux of urine into the renal parenchymal tissue. valvular r. r. valvulaire backflow of blood past a venous valve in the lower limb due to venous insufficiency. vesicoureteral r., vesicoureteric r. r. vésico-urétéral backward flow of urine from the bladder into a ureter.

refract réfracter 1. to cause to deviate. 2. to ascertain errors of ocular refraction.

refraction réfraction 1. the act or process of refracting; specifically, the determination of the refractive errors of the eye and their correction with lenses. 2. the deviation of light in passing obliquely from one medium to another of different density. Adj.: refractive. double r. double r. refraction in which incident rays are divided into two refracted rays, so as to produce a double image. dynamic r. r. dynamique the normal accommodation of the eye which is continually exerted without conscious effort.

refractionist réfractionniste one skilled in determining the refracting power of the eyes and correcting refracting defects.

refractometer réfractomètre 1. an instrument for measuring the refractive power of the eye. 2. an instrument for determining the indexes of refraction of various substances, particularly for determining the strength of lenses for spectacles.

refractory réfractaire 1. resistant to treatment. 2. not responding to a stimulus.

refrangible réfrangible susceptible to being refracted.

refresh rafraîchir to denude an epithelial wound to enhance tissue repair.

refrigeration réfrigération therapeutic application of low temperature.

refusion réinjection the return of blood to the circulation after temporary removal or stoppage of flow.

regeneration régénération, régénérescence the natural renewal of a structure, as of a lost tissue or part. guided tissue r. r. tissulaire guidée treatment of wound tissue using microporous membranes as barriers, so that only specific, desired types of cells can enter the wound and regenerate.

regimen régime a strictly regulated scheme of diet, exercise, or other activity designed to achieve certain ends.

regio regio pl. regiones [L.] region.

region région a plane area with more or less definite boundaries. Adj.: regional. r’s of back r. dorsales the areas into which the back is divided, including the vertebral, sacral, scapular, infrascapular, and lumbar. facial r. r. faciale that comprising the various anatomical regions of the face: buccal (side of oral cavity), infraorbital (below eye), mental (chin), nasal (nose), oral (lips), orbital (eye), parotid (angle of jaw), and zygomatic (cheek bone) regions. homogeneously staining r’s (HSR) r. de coloration homogène long unbanded regions of chromosomes created by gene amplification; they are tumor markers indicative of solid neoplasms with poor prognosis. pectoral r. r. pectorale the aspect of the chest bounded by the pectoralis major muscle, and including the lateral pectoral, mammary, and inframammary regions. perineal r. r. périnéale the region overlying the pelvic outlet, including the anal and genitourinary regions. precordial r. r. précordiale the part of the anterior surface of the body covering the heart and the pit of the stomach.

registrant infirmier d’astreinte a nurse listed on the books of a registry as available for duty.

registrar 1. commis aux inscriptions an official keeper of records. 2. in British hospitals, a resident specialist who acts as assistant to the chief or attending specialist.

registration enregistrement in dentistry, the making of a record of the jaw relations present or desired, or the record so produced.

registry 1. service des astreintes an office where a nurse’s name may be listed as being available for duty. 2. registre a central agency for the collection of pathologic material and related data in a specified field of pathology.

regression régression 1. return to a former or earlier state. 2. subsidence of symptoms or of a disease process. 3. the statistical tendency in successive generations to exhibit values closer and closer to the mean. 4. defensive retreat to an earlier, often infantile, pattern of behavior or thought. 5. a functional relationship between a random variable and the corresponding values of one or more independent variables. Adj.: regressive.

regular régulier [L. regularis; regula rule] normal or conforming to rule; occurring at proper or fixed intervals.

regulation régulation 1. the act of adjusting or state of being adjusted to a certain standard. 2. in biology, the adaptation of form or behavior of an organism to changed conditions. 3. the power to form a whole embryo from stages before the gastrula. Adj.: regulatory.

regulator régulateur a mechanism or process that controls another mechanism or process. cystic fibrosis transmembrane r. (CFTR) r. de la conductance transmembranaire de la mucoviscidose a transmembrane protein primarily functioning as a cAMP-regulated chloride channel that also regulates other ion channels, and found in cell membranes of the respiratory epithelium, pancreas, salivary glands, sweat glands, intestines, and reproductive tract. Mutations have been associated with cystic fibrosis.

regurgitant régurgitant flowing backward.

regurgitation régurgitation 1. flow in the opposite direction from normal. 2. movement of undigested or partially digested food upward through the esophagus, as in vomiting or rumination. aortic r. (AR) r. aortique backflow of blood from the aorta into the left ventricle due to aortic valve insufficiency. mitral r. (MR) r. mitrale backflow of blood from the left ventricle into the left atrium due to mitral valve insufficiency. pulmonic r. (PR) r. pulmonaire backflow of blood from the pulmonary artery into the right ventricle due to pulmonary valve insufficiency. tricuspid r. (TR) r. tricuspidienne the backflow of blood from the right ventricle into the right atrium due to tricuspid valve insufficiency. valvular r. r. valvulaire backflow of blood through the orifices of the heart valves due to imperfect closing of the valves.

rehabilitation 1. réadaptation the restoration of normal form and function after illness or injury. 2. r. rééducation the restoration of the ill or injured patient to optimal functional level in all areas of activity.

rehydration réhydratation the restoration of water or fluid content to a patient or to a substance that has become dehydrated.

reiki reiki [Japanese] a healing tradition of Eastern origin whose purpose is to rebalance the complex energy systems that compose the body when they have become out of balance, using channeling of energy from an unlimited universal energy source through the hands of the practitioner.

reimplantation réimplantation replacement of tissue or a structure in the site from which it was previously lost or removed. ureteral r. r. urétérale ureteroneocystostomy.

reinfection réinfection a second infection by the same agent or a second infection of an organ with a different agent.

reinforcement renforcement in behavioral science, the presentation of a stimulus following a response that increases the frequency of subsequent responses, whether positive to desirable events, or negative to undesirable events which are reinforced in their removal.

reinforcer renforçateur any stimulus that produces reinforcement, a positive r. being a desirable event strengthening responses preceding its occurrence and a negative r. being an undesirable event strengthening responses leading to its termination.

reinfusate liquide de réinfusion fluid for reinfusion into the body, usually after being subjected to a treatment process.

reinfusion réinfusion infusion of body fluid that has previously been withdrawn from the same individual, e.g., reinfusion of ascitic fluid after ultrafiltration.

reinnervation réinnervation restoration of nerve supply to a part from which it has been lost; it may occur spontaneously or by nerve grafting.

reintegration réintégration 1. biological integration after a state of disruption. 2. restoration of harmonious mental function after disintegration of the personality in mental illness.

rejection rejet an immune reaction against grafted tissue that results in failure of the graft to survive.

relapse 1. rechute the return of a disease after its apparent cessation. 2. rechuter to fall back into an illness after a period of remission.

relapsing récidivant recurrent; likely to have periods of remission alternating with attacks of symptomatic disease.

relation relation the condition or state of one object or entity when considered in connection with another. Adj.: relative. object r’s r. d’objets the emotional bonds formed between one person and another, as contrasted with love for and interest in oneself.

relaxant relaxant 1. lessening or reducing tension. 2. an agent that so acts. muscle r. myorelaxant an agent that specifically aids in reducing muscle tension.

reline regarnir, rebaser to resurface the tissue side of a denture with new base material in order to achieve a more accurate fit.

REM MOR rapid eye movements (see under sleep).

rem rem roentgen-e quivalent-man: the amount of any ionizing radiation that has the same biological effectiveness as 1 rad of xrays; 1 rem = 1 rad × RBE (relative biological effectiveness).

remedy remède anything that cures, palliates, or prevents disease. Adj.: remedial. concordant r’s r. alliés in homeopathy, remedies of similar action but of dissimilar origin. inimic r’s r. ennemis in homeopathy, remedies whose actions are antagonistic. tissue r’s r. tissulaires the twelve remedies which, according to the biochemical school of homeopathy, form the mineral bases of the body.

remifentanil rémifentanil an opioid analgesic used as the hydrochloride salt as an anesthesia adjunct.

remineralization reminéralisation restoration of mineral elements, as of calcium salts to bone.

remission rémission diminution or abatement of the symptoms of a disease; the period during which such diminution occurs.

remittent rémittent having periods of abatement and of exacerbation.

remodeling remaniement reorganization or renovation of an old structure. bone r. r. osseux absorption of bone tissue and simultaneous deposition of new bone; in normal bone the two processes are in dynamic equilibrium.

remotivation remotivation any of various group therapy techniques used with long-term, withdrawn patients in mental hospitals to stimulate their communication, vocational, and social skills and interest in their environment.

ren ren pl. renes [L.] kidney.

renal rénal pertaining to the kidney.

reniform réniforme kidney-shaped.

renin rénine a proteolytic enzyme synthesized, stored, and secreted by the juxtaglomerular cells of the kidney; it plays a role in regulation of blood pressure by catalyzing the conversion of angiotensinogen to angiotensin I.

reninism réninisme a condition marked by overproduction of renin. primary r. r. primaire a syndrome of hypertension, hypokalemia, hyperaldosteronism, and elevated plasma renin activity, due to proliferation of juxtaglomerular cells.

renipelvic rénopelvien pertaining to the pelvis of the kidney.

rennin rennine chymosin.

renogastric rénogastrique pertaining to the kidney and stomach.

renography rénographie radiography of the kidney.

renointestinal réno-intestinal pertaining to the kidney and intestine.

renoprival rénoprive pertaining to or caused by lack of kidney function.

renovascular rénovasculaire pertaining to or affecting the blood vessels of the kidney.

renule groupe caliciel an area of kidney supplied by a branch of the renal artery, usually consisting of three or four medullary pyramids and their corresponding cortical substance.

Reoviridae Reoviridae the reoviruses: a family of RNA viruses with a linear double-stranded RNA genome; it includes the genera Orbivirus, Orthoreovirus,Rotavirus, and Coltivirus.

reovirus réovirus 1. any virus belonging to the family Reoviridae. 2. any virus belonging to the genus Orthoreovirus.

reoxygenation réoxygénation in radiobiology, the phenomenon in which hypoxic (and thus radioresistant) tumor cells become more exposed to oxygen (and thus more radiosensitive) by coming into closer proximity to capillaries after death and loss of other tumor cells due to previous irradiation.

repaglinide répaglinide an oral hypoglycemic agent used in the treatment of type 2 diabetes mellitus.

repair réparation the physical or mechanical restoration of damaged or diseased tissues by the growth of healthy new cells or by surgical apposition. Adj.: reparative. Cooper ligament r., McVay r. r. du ligament de Cooper repair of an inguinal hernia by suturing the inguinal falx to the pectineal (Cooper) and inguinal ligaments.

repeat répétition something done or occurring more than once, particularly over and over. long terminal r’s (LTR) r. terminales longues identical DNA sequences, usually several hundred base pairs long, occurring at each end of an integrated retrovirus and essential for integration of the molecule into host DNA. short tandem r. (STR) r. en tandem courte microsatellite. tandem r. r. en tandem 1. arrangement of two or more copies of a nucleotide sequence adjacent to each other within a segment of DNA. 2. arrangement of two or more copies of a gene or two or more copies of a segment of a chromosome adjacent to each other on a chromosome. triplet r. r. de triplets an unstable DNA sequence of three nucleotides, occurring in some human genes and normally repeated in tandem 5 to 50 times. variable number tandem r’s (VNTR) nombre variable de r. en tandem different numbers of tandemly repeated oligonucleotide sequences in the alleles of a gene; such polymorphism can be useful in genetic mapping. See also minisatellite.

replacement remplacement 1. substitution; see also replacement therapy, under therapy. 2. arthroplasty. joint r. r. articulaire arthroplasty.

replantation réimplantation reimplantation.

replicase réplicase 1. a polymerase synthesizing RNA from an RNA template. 2. more generically, any enzyme that replicates nucleic acids, i.e., a DNA or RNA polymerase.

replication réplication 1. a turning back of a part so as to form a duplication. 2. repetition of an experiment to ensure accuracy. 3. the process of duplicating or reproducing, as the replication of an exact copy of a strand of DNA or RNA. Adj.: replicative.

repolarization repolarisation the reestablishment of polarity, especially the return of cell membrane potential to resting potential after depolarization.

repositor levier de reposition an instrument used in returning a displaced organ or tissue to the normal position.

repository dépôt a place where something is stored, in pharmacology referring to the injection, usually intramuscularly, of a long-acting drug, which is slowly absorbed and is therefore prolonged in its action.

repressible répressible capable of undergoing repression.

repression répression 1. the act of restraining, inhibiting, or suppressing. 2. in psychiatry, an unconscious defense mechanism in which unacceptable ideas, fears, and impulses are thrust out or kept out of consciousness. 3. gene r. enzyme r. r. enzymatique interference, usually by the endproduct of a pathway, with synthesis of the enzymes of that pathway. gene r. r. génétique the inhibition of gene transcription of an operon; in prokaryotes repressor binding to the operon is involved.

repressor répresseur in genetics, a protein produced by a regulator gene that binds to the operator region of a structural gene to block initiation of transcription of the gene or operon.

reproduction reproduction 1. the production of offspring by organized bodies. 2. the creation of a similar object or situation; duplication; replication. Adj.: reproductive. asexual r. r. asexuée reproduction without the fusion of sexual cells. cytogenic r. r. cytogénétique production of a new individual from a single germ cell or zygote. sexual r. r. sexuée reproduction by the fusion of a female gamete and a male gamete(bisexual r.) or by development of an unfertilized egg (unisexual r.). somatic r. r. somatique production of a new individual from a multicellular fragment by fission or budding.

reptilase reptilase an enzyme from Russell viper venom used in determining blood clotting time.

repulsion répulsion 1. the act of driving apart or away; a force that tends to drive two bodies apart. 2. in genetics, the occurrence on opposite chromosomes in a double heterozygote of the two mutant alleles of interest.

RES RES reticuloendothelial system.

rescinnamine rescinnamine an alkaloid from various species of Rauwolfia; used as an antihypertensive.

resect réséquer to excise part or all of an organ or other structure.

resection résection excision. root r. r. apicale apicoectomy. transurethral r. of the prostate (TURP) r. transurétrale de la prostate resection of the prostate by means of an instrument passed through the urethra. wedge r. r. cunéiforme périphérique removal of a triangular mass of tissue.

resectoscope résectoscope an instrument with a wide-angle telescope and an electrically activated wire loop for transurethral removal or biopsy of lesions of the bladder, prostate, or urethra.

reserpine réserpine an alkaloid from various species of Rauwolfia; used as an antihypertensive.

reserve 1. réserver to hold back for future use. 2. réserve a supply, beyond that ordinarily used, which may be utilized in emergency. alkali r., alkaline r. r. alcaline the amount of conjugate base components of the blood buffers, the most important being bicarbonate. cardiac r. r. cardiaque potential ability of the heart to perform work beyond that necessary under basal conditions. ovarian r. r. ovarienne the number and quality of oocytes in the ovaries of a woman of childbearing age.

reservoir réservoir 1. a storage place or cavity. 2. cistern. 3. réservoir d’infection an alternate host or passive carrier of a pathogenic organism or parasite. continent ileal r. r. iléocæcal continent 1. a valved intra-abdominal pouch that maintains continence of the feces and is emptied by a catheter when full. 2. a neobladder made from a section of ileum. continent urinary r. r. urinaire continent neobladder. ileoanal r. r. iléoanal a pouch for the retention of feces, formed by suturing together multiple limbs of ileum and connected to the anus by a short conduit of ileum; used with colectomy and ileoanal anastomosis to maintain continence in the treatment of ulcerative colitis. Pecquet r. citerne de Pecquet cisterna chyli.

resident interne 1. resident physician. 2. being or pertaining to such a physician.

residue résidu 1. a remainder; that remaining after removal of other substances. 2. in biochemistry, that portion of a monomer that is incorporated in a polymer. Adj.: residual.

resin résine 1. a solid or semisolid organic substance exuded by plants or by insects feeding on plants, or produced synthetically; they are insoluble in water but mostly soluble in alcohol or ether. 2. a compound made by condensation or polymerization of low-molecular-weight organic compounds. Adj.: resinous. acrylic r’s r. acryliques a class of thermoplastic resins produced by polymerization of acrylic or methacrylic acid or their derivatives; used in a variety of medical and dental applications. anion exchange r. r. échangeuse d’anions see ion exchange r. cation exchange r. r. échangeuse de cations see ion exchange r. cholestyramine r. r. de cholestyramine a synthetic, strongly basic anion exchange resin in the chloride form which chelates bile acids in the intestine, thus preventing their reabsorption; used as an adjunctive therapy to diet in management of certain hypercholesterolemias and in the symptomatic relief of pruritus associated with bile stasis. composite r. ciment dentaire composite a synthetic resin, usually acrylic based, to which a high percentage of inert filler has been added, e.g., coated glass or silica; used chiefly in dental restorations. epoxy r. r. époxy a heat-set resin with toughness, adhesibility, chemical resistance, dielectric properties, and dimensional stability; several modified types are used as denture base material. ion exchange r. r. échangeuse d’ions a high-molecular-weight insoluble polymer of simple organic compounds capable of exchanging its attached ions for other ions in the surrounding medium; classified as (a)cation or anion exchange r’s, depending on which ions the resin exchanges; and (b) carboxylic, sulfonic, etc., depending on the nature of the active groups. podophyllum r. r. de podophyllum podophyllin; a mixture of resins from podophyllum, used as a topical caustic in the treatment of certain papillomas, condylomata acuminata, keratoses, and other epitheliomas.

resistance résistance 1. opposition, or counteracting force. 2. the natural ability of an organism to resist microorganisms or toxins produced in disease. 3. the opposition to the flow of electrical current between two points of a circuit. Symbol R or R. 4. in psychiatry, conscious or unconscious defenses that prevent material in the unconscious from coming into awareness. airway r. r. des voies aériennes the opposition of the tracheobronchial tree to air flow. Symbols R_A, R_AW. androgen r. r. androgénique resistance of target organs to the action of androgens; the result is any of a spectrum of defects. In mild to incomplete types the person may have a definite male phenotype but infertility, or may have ambiguous genitalia. In the complete type the person has a female phenotype but XY chromosomes. drug r. pharmacorésistance the ability of a microorganism to withstand the effects of a drug that are lethal to most members of its species. electrical r. r. électrique resistance (3). multidrug r., multiple drug r. multirésistance aux médicaments in some malignant cell lines, resistance to many structurally unrelated chemotherapy agents in cells that have developed natural resistance to a single cytotoxic compound. vascular r. r. vasculaire the opposition to blood flow in a vascular bed.

resistin résistine an adipocytokine that has been implicated in the development of insulin resistance; it has been suggested that it may be the link between obesity and insulin resistance, but its role remains unclear.

resistive résistif pertaining to or characterized by resistance.

resolution résolution 1. subsidence of a pathologic state. 2. perception as separate of two adjacent points; in microscopy, the smallest distance at which two adjacent objects can be distinguished as separate. 3. définition a measure of the fineness of detail that can be discerned in an image.

resolvent 1. résolvant, résolutif promoting resolution or the dissipation of a pathologic growth. 2. résolutif an agent that promotes resolution.

resonance résonance 1. the prolongation and intensification of sound produced by transmission of its vibrations to a cavity, especially such a sound elicited by percussion. 2. a vocal sound heard on auscultation. 3. the existence of organic chemical structures that can not be accurately represented by a single structural formula, the actual formula lying intermediate between several possible representations differing only in electron position. amphoric r. souffle amphorique an auscultatory sound like that produced by blowing over the mouth of an empty bottle. nuclear magnetic r. r. magnétique nucléaire a measure, by means of applying an external magnetic field to a solution in a constant radiofrequency field, of the magnetic moment of atomic nuclei to determine the structure of organic compounds; the technique is used in magnetic resonance imaging. skodaic r. bruit skodique increased percussion resonance at the upper part of the chest, with flatness below it. tympanitic r. son tympanique 1. the percussion sound heard on an abdomen with tympanites. 2. tenaculum the drumlike reverberation of a cavity full of air. vocal r. (VR) r. vocale the sound of ordinary speech as heard through the chest wall.

resonator résonateur 1. an instrument used to intensify sounds. 2. an electric circuit in which oscillations of a certain frequency are set up by oscillations of the same frequency in another circuit.

resorb résorber to take up or absorb again.

resorcinol résorcinol a bactericidal, fungicidal, keratolytic, exfoliative, and antipruritic agent, used especially as a topical keratolytic in the treatment of acne and other dermatoses.

resorption résorption 1. the lysis and assimilation of a substance, as of bone. 2. reabsorption.

respirable respirable 1. suitable for respiration. 2. small enough to be inhaled.

respiration respiration 1. the exchange of oxygen and carbon dioxide between the atmosphere and the body cells, including ventilation (inhalation and exhalation); diffusion of oxygen from alveoli to blood and of carbon dioxide from blood to alveoli; and transport of oxygen to and carbon dioxide from body cells. 2. ventilation (1). 3. the metabolic processes by which cells generate energy, chiefly in the form of ATP, by the oxidation of organic molecules such as glucose, with the release of carbon dioxide, water, and other oxidized products. abdominal r. r. abdominale breathing accomplished mainly by the abdominal muscles and diaphragm. aerobic r. r. aérobie the oxidative transformation of certain substrates into secretory products, the released energy being used in the process of assimilation. anaerobic r. r. anaérobie respiration in which energy is released from chemical reactions in which free oxygen takes no part. artificial r. r. artificielle that which is maintained by force applied to the body, by stimulation of the phrenic nerve by an electric current, or by mouth-to-mouth method (resuscitation of an apneic victim by direct application of the mouth to his, regularly taking a deep breath and blowing into the victim’s lungs). Biot r. r. de Biot rapid, short breathing with pauses of several seconds, indicating increased intracranial pressure. Cheyne-Stokes r. r. de Cheyne-Stokes breathing with rhythmic waxing and waning of depth of breaths and regularly recurring apneic periods. cogwheel r. r. saccadée breathing with jerky inhalation. electrophrenic r. r. électrophrénique diaphragmatic pacing; induction of respiration by electric stimulation of the phrenic nerve. external r. r. externe exchange of gases between the lungs and blood. internal r. r. interne exchange of gases between the body cells and blood. Kussmaul r., Kussmaul-Kien r. r. de Kussmaul air hunger; deep rapid breathing as seen in respiratory acidosis. paradoxical r. r. paradoxale that in which all or part of a lung is deflated during inhalation and inflated during exhalation, such as in flail chest or paralysis of the diaphragm. tissue r. r. tissulaire internal r.

respirator respirateur ventilator (2). cuirass r. r. cuirasse see under ventilator. Drinker r. r. de Drinker popularly, “iron lung”: an apparatus formerly in wide use for producing artificial respiration over long periods of time, consisting of a metal tank, enclosing the patient’s body, with the head outside, and within which artificial respiration is maintained by alternating negative and positive pressure.

respiratory respiratoire pertaining to respiration.

respirometer respiromètre an instrument for determining the nature of respiration.

response réaction, réponse any action or change of condition evoked by a stimulus. Adj.: responsive. acute phase r. réaction de phase aiguë a group of physiological processes occurring soon after the onset of infection, trauma, inflammatory processes, and some malignant conditions; it includes increase in acute phase proteins in serum, fever, increased vascular permeability, and metabolic and pathologic changes. anamnestic r. réaction anamnestique secondary immune r. autoimmune r. réaction auto-immunitaire the immune response against an autoantigen. conditioned r. réflexe conditionné a response evoked by a conditioned stimulus; a response to a stimulus that was incapable of evoking it before conditioning. galvanic skin r. réflexe psychogalvanique the alteration in the electrical resistance of the skin associated with sympathetic nerve discharge. immune r. réponse immunitaire, réaction immunitaire any response of the immune system to an antigenic stimulus, including antibody production, cell-mediated immunity, and immunological tolerance. inflammatory r. réaction inflammatoire the various changes that tissue undergoes when it becomes inflamed; see inflammation. primary immune r. réponse immunitaire primaire the immune response occurring on the first exposure to an antigen, with specific antibodies appearing in the blood after a multiple day latent period. relaxation r. réponse de relaxation a group of physiologic changes that cause decreased activity of the sympathetic nervous system and consequent relaxation after stimulation of certain regions of the hypothalamus. They may be self-induced through techniques such as meditation and biofeedback. secondary immune r. réponse immunitaire secondaire the immune response occurring on second and subsequent exposures to an antigen, with a stronger response to a lesser amount of antigen, and a shorter lag time compared to the primary immune response. triple r. temps de Lewis a triphasic skin reaction to being stroked with a blunt instrument: first a red line develops at the site due to histamine release, then a flare develops around the red line, and lastly a wheal is formed as a result of local edema. unconditioned r. réponse inconditionnelle an unlearned response, i.e., one that occurs naturally to an unconditioned stimulus.

rest 1. repos repose after exertion. 2. débris a fragment of embryonic tissue retained within the adult organism. 3. appui an extension that helps support a removable partial denture. adrenal r’s inclusions surrénaliennes accessory adrenal glands. incisal r., lingual r., occlusal r. a. incisif a metallic part or extension from a removable partial denture to aid in supporting the prosthesis. suprarenal r’s glandes surrénales accessoires accessory adrenal glands.

restenosis resténose recurrent stenosis, especially of a cardiac valve after surgical correction of the primary condition. Adj.: restenotic.

restiform restiforme shaped like a rope.

restitution restitution the spontaneous realignment of the fetal head with the fetal body, after delivery of the head.

restoration restauration 1. induction of a return to a previous state, as a return to health or replacement of a part to normal position. 2. partial or complete reconstruction of a body part, or the device used in its place. Adj.: restorative.

restraint contrainte the forcible confinement or control of a subject.

restriction restriction 1. a limitation. 2. a thing or process that limits. Adj.: restrictive. intrauterine growth r. (IUGR) r. de croissance intra-utérine see under retardation.

resuscitation résurrection restoration to life of one apparently dead. cardiopulmonary r. (CPR) réanimation cardiopulmonaire the reestablishing of heart and lung action after cardiac arrest or apparent sudden death resulting from electric shock, drowning, respiratory arrest, and other causes. The two major components of CPR are artificial ventilation and closed chest cardiac massage.

resuscitator réanimateur an apparatus for initiating respiration in persons whose breathing has stopped.

retainer ancrage an appliance or device that keeps a tooth or partial denture in proper position.

retardation débilité mentale delay; hindrance; delayed development. fetal growth r., intrauterine growth r. (IUGR) r. de croissance fœtale birth weight below the tenth percentile for gestational age for infants born in a given population, defined as symmetric (both weight and length below normal) or asymmetric (weight below normal, length normal). mental r. retard mental a mental disorder characterized by significantly subaverage general intellectual functioning associated with impairment in adaptive behavior and manifested in the developmental period; classified according to IQ as mild (50–70), moderate (35–50), severe (20–35), and profound (less than 20). psychomotor r. retard psychomoteur generalized slowing of mental and physical activity.

retching nausée strong involuntary effort to vomit.

rete réseau pl. retia [L.] a network or meshwork, especially of blood vessels. r. arteriosum r. artériel an anastomotic network of minute arteries, just before they become arterioles or capillaries. articular r. r. articulaire a network of anastomosing blood vessels in or around a joint. r. mirabile répulsion 1. a vascular network formed by division of an artery or vein into many smaller vessels that reunite into a single vessel. 2. arterial anastomosis of the brain occurring between the external and internal carotid arteries due to longstanding thrombosis of the latter. r. ovarii r. ovarien a homologue of the rete testis, developed in the early female fetus but vestigial in the adult. r. subpapillare r. sous-papillaire the network of arteries at the boundary between the papillary and reticular layers of the dermis. r. testis r. testiculaire a network formed in the mediastinum testis by the seminiferous tubules. r. venosum r. veineux an anastomotic network of small veins.

retention rétention the process of holding back or keeping in position, as persistence in the body of material normally excreted, or maintenance of a dental prosthesis in proper position in the mouth.

reteplase retéplase a recombinant form of tissue plasminogen activator; used as a thrombolytic agent in the treatment of myocardial infarction.

reticula reticula [L.] plural of reticulum.

reticular réticulaire resembling a net.

reticulated réticulé reticular.

reticulation réticulation the formation or presence of a network.

reticulin réticuline a scleroprotein from the connective fibers of reticular tissue.

reticulocyte réticulocyte a young erythrocyte showing a basophilic reticulum under vital staining.

reticulocytopenia réticulocytopénie deficiency of reticulocytes in the blood.

reticulocytosis réticulocytose an excess of reticulocytes in the peripheral blood.

reticuloendothelial réticuloendothélial pertaining to the reticuloendothelium or to the reticuloendothelial system.

reticuloendotheliosis réticuloendothéliose hyperplasia of reticuloendothelial tissue.

reticuloendothelium réticuloendothélium the tissue of the reticuloendothelial system.

reticulohistiocytic réticulohistiocytaire pertaining to or of the nature of a reticulohistiocytoma; see under granuloma.

reticulohistiocytoma réticulohistiocytome a granulomatous aggregation of lipid-laden histiocytes and multinucleated giant cells with pale eosinophilic cytoplasm having a ground glass appearance. It occurs in two forms, reticulohistiocytic granuloma and multicentric reticulohistiocytosis.

reticulohistiocytosis réticulohistiocytose the formation of multiple reticulohistiocytomas. multicentric r. r. multicentrique a systemic disease of polyarthritis of the hands and large joints with nodular reticulohistiocytomas in the skin, bone, and mucous and synovial membranes; it may progress to polyvisceral involvement and death.

reticulopenia réticulopénie reticulocytopenia.

reticulosis réticulose an abnormal increase in cells derived from or related to the reticuloendothelial cells. familial histiocytic r., histiocytic medullary r. r. familiale lymphohistiocytaire a hereditary disorder, usually fatal in infancy, marked by anemia, granulocytopenia, thrombocytopenia, phagocytosis of blood cells, diffuse proliferation of histiocytes, and enlargement of the liver, spleen, and lymph nodes. malignant midline r., polymorphic r. r. maligne médiane a form of angiocentric immunoproliferative lesion involving midline structures of the nose and face.

reticulospinal réticulospinal pertaining to a reticular formation and the spinal cord.

reticulum réticulum pl. reticula [L.] 1. a small network, especially a protoplasmic network in cells. 2. reticular tissue. endoplasmic r. r. endoplasmique an ultramicroscopic organelle of all eukaryotic cells, consisting of an interconnecting network of tubules, flat saccules, and vesicles, extending from the nuclear envelope to the cell surface. There are three compartments: rough, bearing ribosomes on its outer surface of its membrane and specialized for protein synthesis; smooth, which lacks ribosomes and is associated with many metabolic processes; and transitional, from which vesicles bud during the transport of proteins to the Golgi complex. sarcoplasmic r. r. sarcoplasmique a form of agranular reticulum in the sarcoplasm of striated muscle, comprising a system of smoothsurfaced tubules surrounding each myofibril. stellate r. r. étoilé the soft, middle part of the enamel organ of a developing tooth.

retiform rétiforme plexiform.

retina rétine [L.] the innermost tunic of the eyeball, containing the neural elements for reception and transmission of visual stimuli.

retinaculum pl. retinacula [L.] 1. rétinaculum a structure that retains an organ or tissue in place. 2. tenaculum an instrument for retracting tissues during surgery. extensor r. of foot, inferior lame inférieure du ligament annulaire antérieur du tarse a Y-shaped band of fascia passing from the lateral side of the upper surface of the calcaneus across the foot to attach by one arm to the medial malleolus and by the other to the medial side of the plantar aponeurosis. extensor r. of foot, superior lame supérieure du ligament annulaire antérieur du tarse the thickened lower portion of the fascia on the front of the leg, attached to the tibia on one side and the fibula on the other, and holding in place the extensor tendons that pass beneath it. extensor r. of hand ligament annulaire antérieur du carpe the distal part of the antebrachial fascia, overlying the extensor tendons. fibular r., inferior r. r. inférieur des fibulaires inferior peroneal r. fibular r., superior r. r. supérieur des fibulaires superior peroneal r. flexor r. of foot ligament annulaire interne du tarse a strong band of fascia that extends from the medial malleolus down onto the calcaneus, holding in place the tendons of the posterior tibial and flexor muscles as they pass to the sole of the foot, and protecting the posterior tibial vessels and tibial nerve. flexor r. of hand ligament annulaire antérieur du carpe a fibrous band forming the carpal canal through which pass the tendons of the flexor muscles of the hand and fingers. peroneal r., inferior r. intérieur des péroniers a fibrous band that arches over the tendons of the peroneal muscles and holds them in position on the lateral side of the calcaneus. peroneal r., superior supérieur des péroniers a fibrous band that arches over the tendons of the peroneal muscles and helps to hold them in place below and behind the lateral malleolus. r. tendinum l. annulaire a tendinous restraining structure, such as an annular ligament.

retinal 1. rétinien pertaining to the retina. 2. rétinal the aldehyde of retinol, derived from absorbed dietary carotenoids or esters of retinol and having vitamin A activity. In the retina, retinal combines with opsins to form visual pigments. The two isomers 11-cis retinal and all-trans retinal are interconverted in the visual cycle.

retinitis rétinite inflammation of the retina. r. circinata, circinate r. r. circinée circinate retinopathy. exudative r. r. exsudative see under retinopathy. r. pigmentosa r. pigmentaire a group of diseases, often hereditary, marked by progressive loss of retinal response, retinal atrophy, attenuation of retinal vessels, clumping of pigment, and contraction of the visual field. r. proliferans, proliferating r. r. proliférante a condition sometimes due to intraocular hemorrhage, with neovascularization and the formation of fibrous tissue extending into the vitreous from the retinal surface; retinal detachment may be a sequel. suppurative r. r. purulente that due to pyemic infection.

retinoblastoma rétinoblastome a malignant congenital blastoma, hereditary or sporadic, composed of tumor cells arising from the retinoblasts. endophytic r., r. endophytum r. endophytique a retinoblastoma that begins in the inner layers of the retina and spreads toward the center of the globe. exophytic r., r. exophytum r. exophytique a retinoblastoma that begins in the outer layers of the retina and spreads away from the center of the globe.

retinocerebral rétinocérébral affecting both the retina and cerebrum.

retinochoroiditis rétinochoroïdite inflammation of the retina and choroid. r. juxtapapillaris r. juxtapapillaire a small area of inflammation on the fundus near the papilla; seen in young healthy individuals.

retinoic acid acide rétinoïque an oxidized derivative of retinol, believed to be the form of vitamin A that plays a role in the development and growth of bone and in the maintenance of normal epithelial structures. In pharmacology, it often denotes the all-trans isomer (tretinoin); the 13-cis isomer is usually called isotretinoin.

retinoid rétinoïde 1. resembling the retina. 2. retinal, retinol, or any structurally similar natural derivative or synthetic compound, with or without vitamin A activity.

retinol rétinol vitamin A₁; a 20-carbon primary alcohol in several isomers that is the form of vitamin A found in mammals and that can be converted to the metabolically active forms retinal and retinoic acid.

retinomalacia rétinomalacie softening of the retina.

retinopapillitis rétinopapillite inflammation of the retina and optic papilla.

retinopathy rétinopathie any noninflammatory disease of the retina. circinate r. r. circinée a condition in which a circle of white spots encloses the macula, leading to complete foveal blindness. diabetic r. r. diabétique retinopathy associated with diabetes mellitus, which may be of the background type, progressively characterized by microaneurysms, intraretinal punctate hemorrhages, yellow, waxy exudates, cotton-wool patches, and macular edema, or of the proliferative type, characterized by neovascularization of the retina and optic disk, which may project into the vitreous, proliferation of fibrous tissue, vitreous hemorrhage, and retinal detachment. exudative r. r. exsudative that marked by masses of white or yellowish exudate in the posterior part of the fundus oculi, with deposit of cholesterin and blood debris from retinal hemorrhage, and leading to destruction of the macula and blindness. hypertensive r. r. hypertensive that associated with essential or malignant hypertension; changes may include irregular narrowing of the retinal arterioles, hemorrhages in the nerve fiber layers and the outer plexiform layer, exudates and cotton-wool patches, arteriosclerotic changes, and, in malignant hypertension, papilledema. r. of prematurity r. des prématurés a bilateral retinopathy typically occurring in premature infants treated with high concentrations of oxygen, characterized by vascular dilatation, proliferation, tortuosity, edema, retinal detachment, and fibrous tissue behind the lens. proliferative r. r. proliférante the proliferative type of diabetic retinopathy. renal r. r. rénale a retinopathy associated with renal and hypertensive disorders and presenting the same symptoms as hypertensive retinopathy. stellate r. r. stellaire a retinopathy not associated with hypertensive, renal, or arteriosclerotic disorders, but presenting the same symptoms as hypertensive retinopathy.

retinopexy rétinopexie restoring of the retina to its proper anatomical location. pneumatic r. r. pneumatique treatment of retinal detachment by injection of gas into the posterior vitreous cavity such that the gas bubble presses against the area of torn retina, forcing it back into place.

retinoschisis rétinoschisis splitting of the retina, occurring in the nerve fiber layer (juvenile form), or in the external plexiform layer (adult form).

retinoscope rétinoscope an instrument for performing retinoscopy.

retinoscopy rétinoscopie observation of the pupil under a beam of light projected into the eye, as a means of determining refractive errors.

retinosis rétinose any degenerative, noninflammatory condition of the retina.

retinotopic rétinotopique relating to the organization of the visual pathways and visual area of the brain.

retothelium rétothélium reticuloendothelium.

retractile rétractile able to be drawn back.

retraction rétraction the act of drawing back, or condition of being drawn back. clot r. r. du caillot the drawing away of a blood clot from the wall of a vessel, a stage of wound healing caused by contraction of platelets.

retractor 1. écarteur an instrument for holding open the lips of a wound. 2. rétracteur a muscle that retracts.

retrieval remémoration in psychology, the process of obtaining memory information from wherever it has been stored.

retr(o)- rétr(o)- word element [L.], behind; backward.

retroaction rétroaction action in a reversed direction.

retrobulbar rétrobulbaire 1. behind the medulla oblongata. 2. behind the eyeball.

retrocervical rétrocervical behind the cervix uteri.

retrocession rétrocession a going backward; backward displacement.

retrocochlear rétrocochléaire 1. behind the cochlea. 2. denoting the eighth cranial nerve and cerebellopontine angle as opposed to the cochlea.

retrocollic rétrocolique nuchal.

retrocollis rétrocolis spasmodic torticollis in which the head is drawn back.

retrocursive rétrocursif marked by stepping backward.

retrodeviation rétrodéviation retrodisplacement; any displacement backwards, such as retroversion or retroflexion.

retrodisplacement rétrodéplacement retrodeviation.

retroflexion rétroflexion the bending of an organ or part so that its top is thrust backward, particularly, the bending posteriorly of the body of the uterus toward the cervix.

retrogasserian rétrogassérien pertaining to the sensory (posterior) root of the trigeminal (gasserian) ganglion.

retrognathism rétrognathisme, rétrognathie retrusion of the mandible. Adj.: retrognathic.

retrograde rétrograde going backward; retracing a former course; catabolic.

retrogression rétrogression, régression degeneration; deterioration; regression; return to an earlier, less complex condition.

retrolabyrinthine rétrolabyrinthique posterior to the labyrinth.

retrolental rétrolental behind the lens of the eye.

retromolar rétromolaire behind a molar.

retroperitoneal rétropéritonéal posterior to the peritoneum.

retroperitoneum rétropéritoine retroperitoneal space.

retroperitonitis rétropéritonite inflammation of the retroperitoneal space.

retropharyngeal rétropharyngien 1. pertaining to the posterior part of the pharynx. 2. posterior to the pharynx.

retropharyngitis rétropharyngite inflammation of the posterior part of the pharynx.

retroplasia rétroplasie retrograde metaplasia; degeneration of a tissue or cell into a more primitive type.

retroposed rétropositionné displaced backward.

retroposition rétroposition retrodeviation.

retropubic rétropubien posterior to the pubic arch.

retropulsion rétropulsion 1. a driving back, as of the fetal head in labor. 2. tendency to walk backward, as in some cases of tabes dorsalis. 3. an abnormal gait in which the body is bent backward.

retrosigmoidal rétrosigmoïde posterior to the sigmoid sinus.

retrospective rétrospectif looking backward, or directed toward the past.

retrouterine rétro-utérin behind the uterus.

retroversion rétroversion the tipping backward of an entire organ or part.

retrovesical rétrovésical posterior to the urinary bladder.

retrovirus rétrovirus a large group of RNA viruses that includes the leukoviruses and lentiviruses; so called because they carry reverse transcriptase.

retrusion rétrusion the state of being located posterior to the normal position, such as the mandible or a tooth displaced in the line of occlusion. Adj.: retrusive.

reuptake réabsorption reabsorption of a previously secreted substance.

revascularization revascularisation 1. the restoration of blood supply, as after a wound. 2. the restoration of an adequate blood supply to a part by means of a blood vessel graft, as in aortocoronary bypass.

reverberation réverbération duration of neuronal activity well beyond an initial stimulus due to transmission of impulses along branches of nerves arranged in a circle, permitting positive feedback.

reverse transcriptase transcriptase inverse, transcriptase réverse an enzyme that catalyzes the template-directed, step-by-step addition of deoxyribonucleotides to the end of a DNA or RNA primer or growing DNA chain, using a single-stranded RNA template; it occurs in retroviruses and the DNA formed is an intermediate in the formation of progeny RNA.

reversion réversion 1. regression (1). 2. in genetics, the mutation of a mutant phenotype so that the original function is restored, as by mutation of the DNA back to the parental base sequence (reverse mutation) or by suppression.

RF RF rheumatoid factor.

RFA NIDA right frontoanterior (position of the fetus).

RFLP RFLP restriction fragment length polymorphism.

RFP NIDP right frontoposterior (position of the fetus).

RFT NIDT right frontotransverse (position of the fetus).

Rh Rh rhodium.

Rh_null Rh_nul symbol for a rare blood type in which all Rh factors are lacking.

Rhabditis Rhabditis a genus of minute nematodes found mostly in damp earth, and as an accidental parasite in humans.

rhabd(o)- rhabd(o)- word element [Gr.], rod; rod-shaped.

rhabdoid rhabdoïde resembling a rod; rod-shaped.

rhabdomyoblast rhabdomyoblaste a pathologic racket-shaped or spindle-shaped myoblast occurring in rhabdomyosarcoma. Adj.: rhabdomyoblastic.

rhabdomyoblastoma rhabdomyoblastome rhabdomyosarcoma.

rhabdomyolysis rhabdomyolyse disintegration of striated muscle fibers with excretion of myoglobin in the urine.

rhabdomyoma rhabdomyome a benign tumor derived from striated muscle; the cardiac form is considered to be a hamartoma and is often associated with tuberous sclerosis.

rhabdomyosarcoma rhabdomyosarcome a highly malignant tumor of striated muscle derived from primitive mesenchymal cells. alveolar r. r. alvéolaire a type having dense proliferations of small round cells among fibrous septa that form alveoli, seen mainly in adolescents and young adults. embryonal r. r. embryonnaire a type having alternating loosely cellular areas with myxoid stroma and densely cellular areas with spindle cells, seen mainly in infants and small children. pleomorphic r. r. polymorphe a type having large cells with bizarre hyperchromatic nuclei, seen in the skeletal muscles, usually in the limbs of adults.

rhabdosphincter rhabdosphincter a sphincter consisting of striated muscle fibers.

Rhabdoviridae Rhabdoviridae the rhabdoviruses: a family of RNA viruses with a negative-sense single-stranded RNA genome, including the genera Vesiculovirus and Lyssavirus.

rhabdovirus rhabdovirus any virus of the family Rhabdoviridae.

rhachi- rhachi- for words beginning thus, see those beginning rachi-.

rhagades rhagades fissures, cracks, or fine linear scars in the skin, such as around the mouth or in other regions where the skin moves frequently.

Rhamnus Rhamnus [L.] a genus of trees and shrubs often having a cathartic bark and fruit. R. purshiana D.C. is the source of cascara sagrada.

rhaphe rhaphe raphe.

rhegma rhegma a rupture, rent, or fracture.

rhegmatogenous rhegmatogène arising from or caused by a rhegma or tear.

rhenium rhénium chemical element (see Table of Elements), at. no. 75, symbol Re.

rhe(o)- rhé(o)- word element [Gr.], electric current; flow (as of fluids).

rheology rhéologie the science of the deformation and flow of matter, such as the flow of blood through the heart and blood vessels.

rheostosis mélorhéostose a condition of hyperostosis marked by the presence of streaks in the bones; see also melorheostosis.

rheotaxis rhéotaxisme the orientation of an organism in a stream of liquid, with its long axis parallel with the direction of flow, designated negative (moving in the same direction) or positive (moving in the opposite direction).

rheum chassie any watery or catarrhal discharge.

rheumatalgia rhumatalgie chronic rheumatic pain.

rheumatism rhumatisme any of a variety of disorders marked by inflammation, degeneration, or metabolic derangement of the connective tissue structures, especially the joints and related structures, and attended by pain, stiffness, or limitation of motion. Adj.: rheumatic. muscular r. r. musculaire fibrositis. palindromic r. r. palindromique repeated attacks of arthritis and periarthritis without fever and without causing irreversible joint changes.

rheumatoid rhumatoïde 1. resembling rheumatism. 2. associated with rheumatoid arthritis.

rheumatologist rhumatologue a specialist in rheumatology.

rheumatology rhumatologie the branch of medicine dealing with rheumatic disorders, their causes, pathology, diagnosis, treatment, etc.

rhexis rhexis the rupture of a blood vessel or of an organ.

rhigosis perception du froid (par les corpuscules de Krause) [Gr.] the ability to feel cold.

rhinalgia rhinalgie rhinodynia; pain in the nose.

rhinencephalon rhinencéphale 1. the part of the brain once thought to be concerned entirely with olfactory mechanisms, including olfactory nerves, bulbs, tracts, and subsequent connections (all olfactory in function) and the limbic system (not primarily olfactory in function); homologous with olfactory portions of the brain in certain other animals. 2. formerly, the area of the brain comprising the anterior perforated substance, band of Broca, subcallosal area, and paraterminal gyrus. 3. one of the portions of the embryonic telencephalon.

rhinion rhinion [Gr.] the lower end of the suture between the nasal bones.

rhinitis rhinite inflammation of the nasal mucous membrane. allergic r. r. allergique any allergic reaction of the nasal mucosa, occurring perennially (nonseasonal allergic r.) or seasonally (hay fever). atrophic r. r. atrophique, ozène chronic rhinitis with wasting of the mucous membrane and glands. r. caseosa r. caséeuse that with a caseous, gelatinous, and fetid discharge. fibrinous r. r. fibrineuse membranous r. hypertrophic r. r. hypertrophique that with thickening and swelling of the mucous membrane. membranous r. r. membraneuse fibrinous r.; chronic rhinitis with the formation of a false membrane, as in nasal diphtheria. nonseasonal allergic r., perennial r. r. allergique apériodique allergic rhinitis occurring continuously or intermittently all year round, due to exposure to a more or less ever-present allergen, marked by sudden attacks of sneezing, swelling of the nasal mucosa with profuse watery discharge, itching of the eyes, and lacrimation. seasonal allergic r. r. allergique saisonnière hay fever. vasomotor r. r. vasomotrice 1. nonallergic rhinitis in which symptoms like those of allergic rhinitis are brought on by such stimuli as chilling, fatigue, anger, or anxiety. 2. any condition of allergic or nonallergic rhinitis, as opposed to infectious rhinitis.

rhin(o)- rhin(o)- word element [Gr.], nose; noselike structure.

rhinoantritis rhinoantrite inflammation of the nasal cavity and maxillary sinus.

rhinocanthectomy canthectomie interne rhinommectomy.

rhinocele ventricule du bulbe olfactif rhinocoele.

rhinocephaly rhinocéphalie, rhinencéphalie a developmental anomaly characterized by the presence of a proboscis-like nose above eyes partially or completely fused into one.

rhinocheiloplasty rhinochéiloplastie plastic surgery of the lip and nose.

rhinocoele cavité ventriculaire du bulbe olfactif the ventricle of the olfactory lobe of the brain.

rhinodynia rhinodynie rhinalgia.

rhinogenous rhinogène arising in the nose.

rhinokyphosis rhinocyphose an abnormal hump on the ridge of the nose.

rhinolalia rhinolalie rhinophonia; a nasal quality of the voice from some disease or defect of the nasal passages, such as undue patency (r. aperta) or undue closure (r. clausa) of the posterior nares.

rhinolaryngitis rhinolaryngite inflammation of the mucosa of the nose and larynx.

rhinolith rhinolithe a nasal stone or concretion.

rhinolithiasis rhinolithiase a condition associated with formation of rhinoliths.

rhinologist rhinologiste a specialist in rhinology.

rhinology rhinologie the medical specialty that deals with the nose and its diseases.

rhinomanometry rhinomanométrie measurement of the airflow and pressure within the nose during respiration; nasal resistance or obstruction can be calculated from the figures obtained.

rhinommectomy canthectomie interne excision of the inner canthus of the eye.

rhinomycosis rhinomycose fungal infection of the nasal mucosa.

rhinonecrosis rhinonécrose necrosis of the nasal bones.

rhinopathy rhinopathie any disease of the nose.

rhinopharyngitis rhinopharyngite nasopharyngitis.

rhinophonia rhinophonie rhinolalia.

rhinophycomycosis rhinophycomycose a fungal disease caused by Entomophthora coronata, marked by formation of large polyps in the subcutaneous tissues of the nose and paranasal sinuses; orbital involvement and unilateral blindness may follow. Cerebral involvement is common.

rhinophyma rhinophyma a form of rosacea marked by redness, sebaceous hyperplasia, and nodular swelling and congestion of the skin of the nose.

rhinoplasty rhinoplastie plastic surgery of the nose.

rhinorrhagia rhinorragie epistaxis.

rhinorrhea rhinorrhée the free discharge of a thin nasal mucus. cerebrospinal fluid r. r. cérébrospinale discharge of cerebrospinal fluid through the nose.

rhinosalpingitis rhinosalpingite inflammation of the mucosa of the nose and eustachian tube.

rhinoscleroma rhinosclérome a granulomatous disease, ascribed to Klebsiella rhinoscleromatis, involving the nose and nasopharynx; the growth forms hard patches or nodules, which tend to enlarge and are painful to the touch.

rhinoscope rhinoscope a speculum for use in nasal examination.

rhinoscopy rhinoscopie examination of the nose with a speculum, either through the anterior nares (anterior r.) or the nasopharynx (posterior r.).

rhinosinusitis rhinosinusite inflammation of the paranasal sinuses.

rhinosporidiosis rhinosporidiose a fungal disease caused by Rhinosporidium seeberi, marked by large polyps on the mucosa of the nose, eyes, ears, and sometimes the penis and vagina.

rhinotomy rhinotomie incision into the nose.

Rhinovirus Rhinovirus a genus of viruses of the family Picornaviridae that infect the upper respiratory tract and cause the common cold. Over 100 antigenically distinct varieties infect humans.

rhinovirus rhinovirus any virus belonging to the genus Rhinovirus.

Rhipicephalus Rhipicephalus a genus of cattle ticks, many species of which transmit disease-producing organisms, such as Babesia ovis, B. canis, Rickettsia rickettsii, and R. conorii.

rhiz(o)- rhiz(o)- word element [Gr.], root.

rhizoid rhizoïde 1. resembling a root. 2. a filamentous structure of fungi and some algae that extends into the substrate.

Rhizobiaceae Rhizobiaceae a phenotypically diverse family of bacteria of the order Rhizobiales.

Rhizobiales Rhizobiales a heterogeneous order of gram-negative bacteria of the class Alphaproteobacteria.

Rhizobium Rhizobium a genus of gram-negative, aerobic, rod-shaped bacteria of the family Rhizobiaceae; organisms are symbionts that produce nodules on the roots of leguminous plants and fix free nitrogen. R. radiobacter is an occasional opportunistic human pathogen.

rhizolysis rhizolyse percutaneous radiofrequency rhizotomy; percutaneous rhizotomy performed using radio waves.

rhizomelic rhizomélique pertaining to the hips and shoulders (the roots of the limbs).

Rhizopoda Rhizopoda a superclass of protozoa of the subphylum Sarcodina, comprising the amebae.

Rhizopus Rhizopus a genus of fungi (order Mucorales); some species, including R. arrhizus and R. rhizopodoformis, cause mucormycosis.

rhizotomy rhizotomie interruption of a cranial or spinal nerve root, such as by chemicals or radio waves. percutaneous r. r. percutanée that performed without brain surgery, such as by means of glycerol or radio waves.

rhodamine rhodamine any of a group of red fluorescent dyes used to label proteins in various immunofluorescence techniques.

rhodium rhodium chemical element (see Table of Elements), at. no. 45, symbol Rh.

Rhodnius Rhodnius a genus of winged hemipterous insects of South America. R. prolixus transmits Trypanosoma cruzi, the cause of Chagas disease.

rhod(o)- rhod(o)- word element [Gr.], red.

Rhodococcus Rhodococcus a widespread genus of gram-positive, aerobic bacteria of the family Nocardiaceae; R. equi causes bronchopneumonia in foals and can infect immunocompromised humans.

rhodogenesis rhodogenèse regeneration of rhodopsin after its bleaching by light.

rhodophylaxis rhodophylaxie the ability of the retinal epithelium to regenerate rhodopsin. Adj.: rhodophylactic.

rhodopsin rhodopsine visual purple; a photosensitive purple-red chromoprotein in the retinal rods that is bleached to visual yellow (all-trans retinal) by light, thereby stimulating retinal sensory endings.

Rhodospirillales Rhodospirillales a morphologically, metabolically, and ecologically diverse order of bacteria of the class Alphaproteobacteria.

rhombencephalon rhombencéphale hindbrain. 1. the part of the brain developed from the posterior of the three primary brain vesicles of the embryonic neural tube; it comprises the metencephalon (cerebellum and pons) and myelencephalon (medulla oblongata). 2. the most caudal of the three primary brain vesicles in the embryo, later dividing into the metencephalon and myelencephalon.

rhombocoele dilatation du canal rachidien au niveau de la région sacrale the terminal expansion of the canal of the spinal cord.

rhomboid rhomboïde [Gr. rhombos rhomb + -oid] having a shape similar to a rectangle that has been skewed to one side so that the angles are oblique.

rhonchus ronchus pl. rhonchi [L.] a continuous snorelike sound in the throat or bronchial tubes, due to a partial obstruction. Adj.: rhonchal, rhonchial.

r-HuEPO rHuEPO epoetin (recombinant human erythropoietin).

Rhus Rhus a genus of trees and shrubs; contact with certain species produces a severe dermatitis in sensitive persons. The most important toxic species are: R. diversiloba and R. toxicodendron, or poison oak; R. radicans, or poison ivy; and R. vernix, or poison sumac.

rhythm rythme a measured movement; the recurrence of an action or function at regular intervals. Adj.: rhythmic, rhythmical. alpha r. r. alpha electroencephalographic waves having a uniform rhythm and average frequency of 10 per second, typical of a normal person awake in a quiet resting state. atrial escape r. r. d’échappement auriculaire a cardiac dysrhythmia occurring when sustained suppression of sinus impulse formation causes other atrial foci to act as cardiac pacemakers. atrioventricular (AV) junctional r. r. nodal auriculoventriculaire (AV) the heart rhythm that results when the atrioventricular junction acts as pacemaker. atrioventricular (AV) junctional escape r. r. d’échappement auriculoventriculaire (AV) a cardiac rhythm of four or more AV junctional escape beats at a rate below 60 beats per minute. beta r. r. bêta electroencephalographic waves having a frequency of 18 to 30 per second, typical during periods of intense activity of the nervous system. circadian r. r. circadien the regular recurrence in cycles of approximately 24 hours from one stated point to another, e.g., certain biological activities that occur at that interval regardless of constant darkness or other conditions of illumination. coupled r. r. bigéminé heart beats occurring in pairs, the second beat usually being a ventricular premature beat; see also bigeminal pulse. delta r. r. delta rhythm on the electroencephalogram consisting of delta waves. ectopic r. r. ectopique a heart rhythm initiated by a focus outside the sinoatrial node. escape r. r. d’échappement a heart rhythm initiated by lower centers when the sinoatrial node fails to initiate impulses, when its rhythmicity is depressed, or when its impulses are completely blocked. gallop r. r. de galop an auscultatory finding of three (triple r.) or four (quadruple r.) heart sounds; the extra sounds occur in diastole and are related either to atrial contraction (S₄ gallop), to early rapid filling of a ventricle (S₃ gallop), or to concurrence of both events (summation gallop). idioventricular r. r. idioventriculaire a sustained series of impulses propagated by an independent pacemaker within the ventricles, with a rate of 20 to 50 beats per minute. infradian r. r. infradien the regular recurrence in cycles of more than 24 hours, as certain biological activities which occur at such intervals, regardless of conditions of illumination. nodal r. r. nodal atrioventricular junctional r. pendulum r. r. pendulaire alternation in the rhythm of the heart sounds in which the diastolic and systolic sounds are nearly identical and the heartbeat resembles the tick of a watch. quadruple r. r. quadruple the gallop rhythm cadence produced when all four heart sounds recur in successive cardiac cycles. reciprocal r. r. réciproque a cardiac dysrhythmia established by a sustained reentrant mechanism in which impulses traveling back toward the atria also travel forward to reexcite the ventricles, so that each cycle contains a reciprocal beat, with two ventricular contractions. reciprocating r. r. réciproque a cardiac dysrhythmia in which an impulse initiated in the atrioventricular node travels toward both the atria and ventricles, followed by cycles of bidirectional propagation of the impulse alternately initiating from those impulses traveling up and those traveling down. reentrant r. r. par réentrée an abnormal cardiac rhythm resulting from reentry. sinoatrial r., sinus r. r. sinoatrial the normal heart rhythm originating in the sinoatrial node. supraventricular r. r. supraventriculaire any cardiac rhythm originating above the ventricles. theta r. r. thêta rhythm on the electroencephalogram consisting of theta waves. triple r. r. à trois temps the cadence produced when three heart sounds recur in successive cardiac cycles; see also gallop r. ultradian r. r. ultradien the regular recurrence in cycles of less than 24 hours, as certain biological activities which occur at such intervals, regardless of conditions of illumination. ventricular r. r. ventriculaire 1. idioventricular r. 2. any cardiac rhythm controlled by a focus within the ventricles.

rhythmicity rythmicité 1. the state of having rhythm. 2. automaticity (2).

rhytid ride pl. rhytides a wrinkle in the skin.

rhytidectomy rhytidectomie excision of skin for elimination of wrinkles.

rhytidoplasty ridectomie rhytidectomy.

rhytidosis rhytidosis a wrinkling, as of the cornea.

rib côte any one of the paired bones, 12 on either side, extending from the thoracic vertebrae toward the median line on the ventral aspect of the trunk, forming the major part of the thoracic skeleton. The upper seven are true r’s; the lower five are false r’s, with the lowest two of the latter also called floating r’s. See illustration and Plate 1. abdominal r’s, asternal r’s c. abdominales false r’s. cervical r. c. cervicale a supernumerary rib arising from a cervical vertebra. false r’s fausses c. the five lower ribs on either side, not attached directly to the sternum. floating r’s c. flottantes the two lower false ribs on either side, usually without anterior attachment. slipping r. c. glissante, syndrome de Cyriax one whose attaching cartilage is repeatedly dislocated. true r’s c. vraies the seven upper ribs on either side, connected to the sternum by their costal cartilages.

ribavirin ribavirine a broad-spectrum antiviral used in the treatment of severe viral pneumonia caused by respiratory syncytial virus, particularly in high-risk infants; also used in conjunction with interferon alfa-2b in the treatment of chronic hepatitis C.

riboflavin riboflavine vitamin B₂; a heatstable, water-soluble flavin of the vitamin B complex, found in milk, organ meats, eggs, leafy green vegetables, whole grains and enriched cereals and breads, and various algae; it is an essential nutrient for humans and is a component of two coenzymes, FAD and FMN, of flavoproteins, which function as electron carriers in oxidation-reduction reactions. Deficiency of the vitamin is known as ariboflavinosis.

ribonuclease ribonucléase an enzyme which catalyzes the depolymerization of ribonucleic acid.

ribonucleic acid (RNA) acide ribonucléique the nucleic acid in which the sugar is ribose, constituting the genetic material in the RNA viruses, and playing a role in the flow of genetic information in all cells; it is a linear polymer which on hydrolysis yields adenine, guanine, cytosine, uracil, ribose, and phosphoric acid and which may contain extensive secondary structure. For specific types of RNA, see under RNA.

ribonucleoprotein (RNP) ribonucléoprotéine a complex of protein and ribonucleic acid. small nuclear r. (snRNP) petite r. nucléaire any of a group of ribonucleoproteins, each composed of a small nuclear RNA (snRNA) associated with approximately 10 to 20 polypeptides; involved in posttranscriptional RNA processing

ribonucleoside ribonucléoside a nucleoside in which the purine or pyrimidine base is combined with ribose.

ribonucleotide ribonucléotide a nucleotide in which the purine or pyrimidine base is combined with ribose.

ribose ribose an aldopentose present in ribonucleic acid (RNA).

ribosome ribosome any of the intracellular ribonucleoprotein particles concerned with protein synthesis; they consist of reversibly dissociable units and are found either bound to cell membranes or free in the cytoplasm. They may occur singly or occur in clusters (polyribosomes). Adj.: ribosomal.

ribosyl ribosyl a glycosyl radical formed from ribose.

ribozyme ribozyme an RNA molecule with catalytic activity; the reactions catalyzed may be intramolecular, e.g., self-splicing, or intermolecular.

ricin ricine a phytotoxin in the seeds of the castor oil plant (Ricinus communis), used in the synthesis of immunotoxins.

Ricinus Ricinus a genus of plants, including R. communis, or castor oil plant, whose seeds contain castor oil and ricin.

rickets rachitisme a condition due to vitamin D deficiency, especially in infancy and childhood, with disturbance of normal ossification, marked by bending and distortion of the bones, nodular enlargements on the ends and sides of the bones, delayed closure of the fontanelles, muscle pain, and sweating of the head. adult r. r. adulte osteomalacia. familial hypophosphatemic r. r. hypophosphatémique familial any of several inherited disorders of proximal renal tubule function causing phosphate loss, hypophosphatemia, and skeletal deformities, including rickets and osteomalacia. fetal r. r. fœtal achondroplasia. hereditary hypophosphatemic r. with hypercalciuria r. hypophosphatémique héréditaire avec hypercalciurie a form of familial hypophosphatemic rickets; hypophosphatemia is accompanied by elevated serum 1,25-dihydroxyvitamin D, increased intestinal absorption of calcium and phosphate, and hypercalciuria. hypophosphatemic r. r. hypophosphatémique any of a group of disorders characterized by rickets associated with hypophosphatemia, resulting from dietary phosphorus deficiency or due to defects in renal tubular function; skeletal deformities are present but hypocalcemia, myopathy, and tetany are absent and serum parathyroid hormone is normal. oncogenous r. r. oncogène oncogenous osteomalacia occurring in children. pseudovitamin D-deficiency r. r. par pseudo-carence en vitamine D vitamin D-dependent r., sometimes specifically the type I form. refractory r. syndrome d’Albright-Butler-Bloomberg vitamin D-resistant r. vitamin D-dependent r. r. vitaminodépendant either of two (types I and II) inherited disorders characterized by myopathy, hypocalcemia, moderate hypophosphatemia, secondary hyperparathyroidism, and subnormal serum concentrations of 1,25-dihydroxyvitamin D; type I can be overcome by high doses of vitamin D, but type II cannot. vitamin D-resistant r. r. vitaminorésistant 1. X-linked hypophosphatemia. 2. any of a group of disorders characterized by rickets but not responding to high doses of vitamin D; most are forms of familial hypophosphatemic rickets.

Rickettsia Rickettsia a genus of bacteria of the family Rickettsiaceae, transmitted by lice, fleas, ticks, and mites to humans and other animals, causing various diseases. R. africae R. africae a species occurring southern Africa, spread by the ticks of the genus Amblyomma; it causes African tick-bite fever. R. akari R. akari the etiologic agent of rickettsialpox, transmitted by the mite Allodermanyssus sanguineus from the reservoir of infection in house mice. R. australis R. australis the etiologic agent of Queensland tick typhus, transmitted by Ixodes ticks. R. conorii R. conorii the etiologic agent of boutonneuse fever and possibly other tickborne illnesses; transmitted by Rhipicephalus and Haemaphysalis ticks. R. japonica R. japonica the etiologic agent of Japanese spotted fever, transmitted by Ixodes ticks. R. prowazekii R. prowazekii the etiologic agent of epidemic typhus and Brill-Zinsser disease, transmitted by Pediculus humanus. R. rickettsii R. rickettsii the etiologic agent of Rocky Mountain spotted fever, transmitted by Dermacentor, Rhipicephalus, Haemaphysalis, Amblyomma, and Ixodes ticks.

rickettsia rickettsie pl. rickettsiae an individual organism of the Rickettsiaceae. Adj.: rickettsial.

Rickettsiaceae Rickettsiaceae a family of bacteria of the the order Rickettsiales.

rickettsial rickettsiose pertaining to or caused by rickettsiae.

Rickettsiales Rickettsiales an order of gramnegative bacteria of the class Alphaproteobacteria. Organisms are parasites of vertebrates and invertebrates and multiply only inside cells of the host; some are pathogenic.

rickettsialpox rickettsiose vésiculaire a febrile disease with a vesiculopapular eruption, resembling chickenpox clinically, caused by Rickettsia akari.

rickettsicidal rickettsicide lethal to rickettsiae.

rickettsiosis rickettsiose infection with rickettsiae.

ridge crête a linear projection or projecting structure; a crest. dental r. c. dentaire any linear elevation on the crown of a tooth. dermal r’s c. papillaires cristae cutis. genital r., gonadal r. c. génitale a bulge on the medial side of the embryonic mesonephros; the primordial germ cells become embedded in it, forming the primordium of the testis or ovary. healing r. induration sous-cutanée an indurated ridge that normally forms deep to the skin along the length of a healing wound. interureteric r. bourelet interurétéral a fold of mucous membrane extending across the bladder between the ureteric orifices. mammary r. c. mammaire a ridge of thickened epithelium from axilla to groin on each side in the mammalian embryo, along which nipples and mammary glands develop, all but one pair usually disappearing in the human. mesonephric r. c. de Wolff the more lateral portion of the urogenital ridge, giving rise to the mesonephros. rete r’s c. épidermiques inward projections of the epidermis into the dermis, as seen histologically in vertical sections. synaptic r. c. synaptique a wedge-shaped projection of a cone pedicle or of a rod spherule, on either side of which lie the horizontal cells whose dendrites are inserted into the ridge. urogenital r. c. urogénitale a longitudinal ridge in the embryo, lateral to the mesentery, which later divides into the mesonephric and gonadal ridges.

rifabutin rifabutine an antibacterial used for the prevention of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection.

rifampicin rifampicine rifampin.

rifampin rifampine a semisynthetic derivative of rifamycin, with the antibacterial actions and uses of the rifamycin group.

rifamycin rifamycine any of a family of antibiotics biosynthesized by a strain of Streptomyces mediterranei, effective against a broad spectrum of bacteria, including gram-positive cocci, some gram-negative bacilli, and Mycobacterium tuberculosis and certain other mycobacteria; used for the treatment of tuberculosis and the prophylaxis of meningococcal infections.

rifapentine rifapentine a synthetic rifamycin antibiotic used in the treatment of pulmonary tuberculosis.

rifaximin rifaximine a semisynthetic derivative of rifamycin, used for the treatment of traveler’s diarrhea caused by noninvasive strains of Escherichia coli.

rigidity rigidité inflexibility or stiffness. claspknife r. phénomène du canif increased tension in the extensors of a joint when it is passively flexed, giving way suddenly on exertion of further pressure. cogwheel r. r. pallidale tension in a muscle which gives way in little jerks when the muscle is passively stretched. decerebrate r. r. de décérébration rigid extension of an animal’s legs as a result of decerebration; occurring in humans as a result of lesions in the upper brainstem.

rigor rigor [L.] chill; rigidity. r. mortis rigidité cadavérique the stiffening of a dead body accompanying depletion of adenosine triphosphate in the muscle fibers.

riluzole riluzole a compound used to prolong survival time in the treatment of amyotrophic lateral sclerosis.

rim bord a border or edge. bite r., occlusion r., record r. bourrelet d’occlusion a border constructed on temporary or permanent denture bases in order to record the maxillomandibular relation and for positioning of the teeth.

rima rima pl. rimae [L.] a cleft or crack. r. glottidis r. glottidis, fente glottique the elongated opening between the true vocal cords and between the arytenoid cartilages. r. oris r. oris, orifice buccal the opening of the mouth. r. palpebrarum r. palpebrarum palpebral fissure.

rimantadine rimantadine an antiviral agent used in the prophylaxis and treatment of influenza A.

rimexolone rimexolone a corticosteroid used as a topical antiinflammatory in the treatment of inflammation following eye surgery and of uveitis affecting the anterior structures of the eye.

rimula rimula pl. rimulae [L.] a minute fissure, especially of the spinal cord or brain.

ring anneau 1. any annular or circular organ or area. 2. in chemistry, a collection of atoms united in a continuous or closed chain. Albl r. a. d’Albl a ring-shaped shadow in radiographs of the skull, caused by aneurysm of a cerebral artery. Bandl r. a. de Bandl pathologic retraction r.; see retraction r. benzene r. a. benzénique the closed hexagon of carbon atoms in benzene, from which different benzene compounds are derived by replacement of hydrogen atoms. Cannon r. a. de Cannon a focal contraction seen radiographically at the mid-third of the transverse colon, marking an area of overlap between the superior and inferior nerve plexuses. common tendinous r. a. tendineux commun the annular ligament of origin common to the recti muscles of the eye, attached to the edge of the optic canal and the inner part of the superior orbital fissure. conjunctival r. a. conjonctival a ring at the junction of the conjunctiva and cornea. constriction r. a. de contraction a contracted area of the uterus, where the resistance of the uterine contents is slight, as over a depression in the contour of the fetus, or below the presenting part. femoral r. a. fémoral the abdominal opening of the femoral canal, normally closed by the crural septum and peritoneum. fibrous r’s of heart a. fibreux du cœur see anulus fibrosus (1). greater r. of iris zone ciliaire de l’iris the less coarsely striated outer concentric circle on the anterior surface of the iris. inguinal r., deep a. inguinal profond an aperture in the transverse fascia for the spermatic cord or the round ligament. inguinal r., superficial a. inguinal superficiel an opening in the aponeurosis of the external oblique muscle for the spermatic cord or the round ligament. Kayser-Fleischer r. a. de Kayser-Fleischer a gray-green to red-gold pigmented ring at the outer margin of the cornea, seen in progressive lenticular degeneration and pseudosclerosis. Landolt r’s a. de Landolt broken rings used in testing visual acuity. lesser r. of iris a. de l’iris mineur the more coarsely striated inner concentric circle on the anterior surface of the iris. mitral r. a. mitral see anulus fibrosus. retraction r. a. de rétraction a ringlike thickening and indentation occurring in normal labor at the junction of the isthmus and corpus uteri, delineating the upper contracting portion and the lower dilating portion (physiologic retraction r.), or a persistent retraction ring in abnormal or prolonged labor that obstructs expulsion of the fetus (pathologic retraction r.). Schwalbe r. a. de Schwalbe a circular ridge composed of collagenous fibers surrounding the outer margin of the Descemet membrane. scleral r. a. scléral a white ring seen adjacent to the optic disk in ophthalmoscopy when the retinal pigment epithelium and choroid do not extend to the disk. tracheal r’s a. trachéaux tracheal cartilages: the 16 to 20 incomplete rings which, held together and enclosed by a strong, elastic, fibrous membrane, constitute the wall of the trachea. tricuspid r. a. tricuspide see anulus fibrosus. tympanic r. a. tympanique the bony ring forming part of the temporal bone at birth and developing into the tympanic plate. umbilical r. a. ombilical the aperture in the fetal abdominal wall through which the umbilical cord communicates with the fetus. vascular r. a. vasculaire a developmental anomaly of the aortic arch wherein the trachea and esophagus are encircled by vascular structures, many variations being possible.

ringworm teigne tinea.

risedronate risédronate an inhibitor of bone resorption used as the sodium salt in the treatment of osteitis deformans and for the prevention and treatment of osteoporosis.

risperidone rispéridone an antipsychotic agent, which may act by a combination of dopamine and serotonin antagonism.

RIST RIST radioimmunosorbent test.

risus rictus [L.] laughter. r. sardonicus risus sardonicus a grinning expression produced by spasm of facial muscles.

ritodrine ritodrine a beta₂-adrenergic agonist used as the hydrochloride salt as a smooth muscle (uterine muscle) relaxant to delay uncomplicated premature labor.

ritonavir ritonavir an HIV protease inhibitor used in treatment of HIV infection and AIDS.

rituximab rituximab a monoclonal antibody that binds the antigen CD20; used as an antineoplastic in the treatment of CD20-positive, B-cell non-Hodgkin lymphoma.

rivalry rivalité a state of competition or antagonism. sibling r. r. fraternelle competition between siblings for the love, affection, and attention of one or both parents or for other recognition or gain.

rivastigmine rivastigmine a cholinesterase inhibitor used as the tartrate salt as an adjunct in the treatment of dementia of the Alzheimer type.

rizatriptan rizatriptan a selective serotonin receptor agonist used as the benzoate salt in the acute treatment of migraine.

riziform riziforme resembling grains of rice.

RLF RLF retinopathy of prematurity (retrolental fibroplasia).

RLL RLL right lower lobe (of lungs).

RMA MIDA right mentoanterior (position of the fetus).

RML RML right middle lobe (of lungs).

RMP MIDP right mentoposterior (position of the fetus).

RMT MIDT right mentotransverse (position of the fetus).

RN IDE registered nurse.

Rn Rn radon.

RNA ARN ribonucleic acid. complementary RNA (cRNA) A. complémentaire viral RNA that is transcribed from negative-sense RNA and serves as a template for protein synthesis. heterogeneous nuclear RNA (hnRNA) A. nucléaire hétérogène a diverse group of long primary transcripts formed in the eukaryotic nucleus, many of which will be processed to mRNA molecules by splicing. messenger RNA (mRNA) A. messager RNA molecules, usually 400 to 10,000 bases long, that serve as templates for protein synthesis (translation). negative-sense RNA A. de sens négatif viral RNA with a base sequence complementary to that of mRNA; during replication it serves as a template for the transcription of viral complementary RNA. positive-sense RNA A. de sens positif viral RNA with the same base sequence as mRNA; during replication it functions as mRNA, serving as a template for protein synthesis. ribosomal RNA (rRNA) A. ribosomique that which together with proteins forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. small nuclear RNA (snRNA) petit ARN nucléaire any of a class of small RNA molecules found in the nucleus, usually as small nuclear ribonucleoproteins (snRNP’s) and involved in posttranscriptional RNA processing. transfer RNA (tRNA) A. de transfert 20 or more varieties of small RNA molecules functioning in translation; each variety carries a specific amino acid to a site specified by an RNA codon, binding to amino acid, ribosome, and to the codon via an anticodon region.

RNase RNase ribonuclease.

RNP RNP ribonucleoprotein.

ROA OIDA right occipitoanterior (position of the fetus).

Rochalimaea Rochalimaea a former genus of bacteria, now merged with Bartonella.

rocuronium rocuronium a nondepolarizing neuromuscular blocking agent, used as the bromide salt as an adjunct in general anesthesia to facilitate endotracheal intubation and as a skeletal muscle relaxant during surgery or mechanical ventilation

rod bâtonnet 1. a straight, slim mass of substance. 2. retinal rod Corti r’s piliers de Corti pillar cells. enamel r’s prismes de l’émail the approximately parallel rods or prisms forming the enamel of the teeth. olfactory r. b. olfactif the slender apical portion of an olfactory bipolar neuron, a modified dendrite extending to the surface of the epithelium. retinal r. b. rétinien a specialized cylindrical segment of the visual cells containing rhodopsin; the rods serve night vision and detection of motion, and together with the retinal cones form the light-sensitive elements of the retina.

rodent 1. rongeur an order of mammals characterized by large chisel-shaped incisors, including the rats, mice, and squirrels, many of which are reservoirs for infectious diseases. 2. rongeant gnawing; corroding.

rodenticide rodenticide 1. destructive to rodents. 2. an agent destructive to rodents.

roentgen röntgen the international unit of x- or γ-radiation; it is the quantity of x- or γ-radiation such that the associated corpuscular emission per 0.001293 g of dry air produces in air ions carrying 1 electrostatic unit of electrical charge of either sign. Symbol R.

roentgenography radiographie radiography. Adj.: roentgenographic.

roentgenologist radiologue radiologist.

roentgenology radiologie radiology.

roentgenoscope appareil de radioscopie fluoroscope.

roentgenoscopy radioscopie fluoroscopy.

rofecoxib rofécoxib a nonsteroidal anti- inflammatory drug used in the treatment of osteoarthritis, acute pain, and dysmenorrhea.

role rôle the behavior pattern that an individual presents to others. gender r. r. sexuel the public expression of gender; the image projected by a person that identifies their maleness or femaleness, which need not correspond to their gender identity.

Rolfing Rolfing service mark for a bodywork technique consisting of systematic manipulation of the connective tissue in order to improve posture and to relieve chronic musculoskeletal pain and stress.

rombergism signe de Romberg Romberg sign.

rongeur pince-gouge [Fr.] a forceps-like instrument for cutting tough tissue, particularly bone.

room salle a place in a building, enclosed and set apart for occupancy or for performance of certain procedures. operating r. s. d’opération one especially equipped for the performance of surgical operations. recovery r. s. de réveil, s. de réanimation postanesthesia care unit.

rooming-in cohabitation the practice of keeping a newborn infant in a crib near the mother’s bed instead of in a nursery during the hospital stay.

root racine that portion of an organ, such as a tooth, hair, or nail, that is buried in the tissues, or by which it arises from another structure. anterior r. of spinal nerve r. rachidienne antérieure the anterior, or motor, division of each spinal nerve, attached centrally to the spinal cord and joining peripherally with the posterior root to form the nerve before it emerges from the intervertebral foramen. motor r. of spinal nerve r. rachidienne motrice anterior r. of spinal nerve. nerve r’s r. rachidiennes the series of paired bundles of nerve fibers that emerge at each side of the spinal cord, termed posterior (or dorsal) or anterior (or ventral) according to their position. There are 31 pairs (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal), each corresponding posterior and anterior root joining to form a spinal nerve. Certain cranial nerves, e.g., the trigeminal, also have nerve roots. posterior r. of spinal nerve r. rachidienne postérieure the posterior, or sensory, division of each spinal nerve, attached centrally to the spinal cord and joining peripherally with the anterior root to form the nerve before it emerges from the intervertebral foramen. sensory r. of spinal nerve r. rachidienne sensitive posterior r. of spinal nerve. r. of tongue r. de la langue the posterior part of the tongue, attached inferiorly to the hyoid bone.

ROP OIDP right occipitoposterior (position of the fetus).

ropinirole ropinirole a dopamine agonist used as the hydrochloride salt as an antidyskinetic in the treatment of Parkinson disease.

ropivacaine ropivacaïne a local anesthetic of the amide type, used as the hydrochloride salt for percutaneous infiltration anesthesia, peripheral nerve block, and epidural block.

rosacea rosacée a chronic condition of the skin of the face, marked by flushing, followed by red coloration due to dilatation of the capillaries, often with papules and acnelike pustules.

rosaniline rosaniline a triphenylmethane derivative, the basis of various dyes and a component of basic fuchsin.

rosary chapelet a structure resembling a string of beads. rachitic r. c. rachitique see under bead.

roseola roséole [L.] 1. any rose-colored rash. 2. exanthema subitum. r. infantum r. infantile exanthema subitum.

Roseomonas Roseomonas a genus of gramnegative, aerobic bacteria of the family Acetobacteraceae that produce a pale pink pigment; members of this genus are occasional pathogens, chiefly in immunocompromised or debilitated patients.

rosette rosette [Fr.] any structure or formation resembling a rose, such as the clusters of polymorphonuclear leukocytes around a globule of lipid nuclear material, as observed in the test for disseminated lupus erythematosus. Flexner- Wintersteiner r. r. de Flexner-Wintersteiner a spoke- and wheel-shaped cell formation seen in retinoblastoma and certain other ophthalmic tumors. Homer Wright r. r. d’Homer Wright a circular or spherical grouping of dark tumor cells around a pale, eosinophilic, central area that contains neurofibrils but lacks a lumen; seen in some medulloblastomas, neuroblastomas, and retinoblastomas or other ophthalmic tumors.

rosiglitazone rosiglitazone an antidiabetic agent that increases insulin sensitivity, used as the maleate salt in the treatment of type 2 diabetes mellitus.

rosin colophane a solid resin obtained from species of Pinus; it is used in preparation of ointments and plasters and in many products such as chewing gum, polishes, and varnishes, but is a common cause of contact allergy.

rostellum rostellum pl. rostellae [L.] a small protuberance of beak, especially the fleshy protuberance of the scolex of a tapeworm, which may or may not bear hooks.

rostrad rostrad 1. toward a rostrum; nearer the rostrum in relation to a specific point of reference. 2. cephalad.

rostral rostral 1. pertaining to or resembling a rostrum; having a rostrum or beak. 2. situated toward a rostrum or toward the beak (oral and nasal region), which may mean superior (in relationships of areas of the spinal cord) or anterior or ventral (in relationships of brain areas).

rostrate rostré having a beaklike process.

rostrum rostre pl. rostra,rostrums [L.] a beak- shaped process.

rot pourriture decay. liver r. grande douve a disease of sheep, and sometimes of humans, due to Fasciola hepatica.

rotablation rotablation an atherectomy technique in which a rotating bur is inserted through a catheter into an artery; the burr rotates and debulks atherosclerotic plaque.

rotation rotation the process of turning around an axis. In obstetrics, the turning of the fetal head (or presenting part) for proper orientation to the pelvic axis. Adj.: rotary, rotatory. optical r. r. optique the quality of certain optically active substances whereby the plane of polarized light is changed, so that it is rotated in an arc the length of which is characteristic of the substance. van Ness r. opération de Van Ness fusion of the knee joint and rotation of the ankle to function as the knee; done to correct a congenitally missing femur.

Rotavirus Rotavirus rotaviruses; a genus of viruses of the family Reoviridae, having a wheel-like appearance, that cause acute infantile gastroenteritis and cause diarrhea in young children and many animal species.

rotavirus rotavirus any member of the genus Rotavirus. Adj.: rotaviral.

rotenone roténone a poisonous compound from derris root and other roots; used as an insecticide.

Rothia Rothia a genus of aerobic, gram-positive, non-spore-forming bacteria of the family Micrococcaceae. R. dentocariosa and R. mucilaginosa are inhabitants of the oral cavity and can cause infective endocarditis.

roughage matière cellulosique indigestible material such as fibers or cellulose in the diet.

rouleau rouleau érythrocytaire pl. rouleaux [Fr.] an abnormal group of red blood cells adhering together like a roll of coins.

roundworm lombric any worm of the class Nematoda; a nematode.

RPF FPR renal plasma flow.

R Ph R Ph Registered Pharmacist.

rpm r/min revolutions per minute.

RQ QR respiratory quotient.

RRA RRA Registered Record Administrator.

-rrhage, -rrhagia -rragie word element [Gr.], excessive flow. Adj.: -rrhagic.

-rrhea -rrhée word element [Gr.], profuse flow. Adj.: -rrheic.

-rrhexis -rrhexis word element [Gr.], breaking; rupturing; splitting.

rRNA ARNr ribosomal RNA.

RSA SIDA right sacroanterior (position of the fetus).

RScA RScA right scapuloanterior (position of the fetus).

RScP RScP right scapuloposterior (position of the fetus).

RSNA RSNA Radiological Society of North America.

RSP SIDP right sacroposterior (position of the fetus).

RST SIDT right sacrotransverse (position of the fetus).

RSV VRS respiratory syncytial virus; Rous sarcoma virus.

RTF FTR resistance transfer factor.

Ru Ru ruthenium.

RU-486 RU-486 mifepristone.

rub 1. frotter to move something over a surface with friction. 2. frottement the action of such movement. 3. frottement friction rub friction r. frottement an auscultatory sound caused by the rubbing together of two serous surfaces, as in pericardial rub. pericardial r., pericardial friction r. f. péricardique a scraping or grating friction rub heard with the heart beat, usually a to-and-fro sound, associated with pericarditis or other pathological condition of the pericardium. pleural r., pleuritic r. f. pleural a friction rub caused by friction between the visceral and costal pleurae.

rubefacient rubéfiant 1. reddening the skin by producing hyperemia. 2. an agent that so acts.

rubella rubéole German measles: a mild viral infection marked by a pink macular rash, fever, and lymph node enlargement most often affecting children and nonimmune young adults; transplacental infection of the fetus in the first trimester may produce death of the conceptus or severe developmental anomalies. See also congenital rubella syndrome, under syndrome.

rubeola rougeole a synonym for measles in English and for German measles in French and Spanish.

rubeosis rubéose redness. r. iridis r. de l’iris a condition characterized by a new formation of vessels and connective tissue on the surface of the iris, frequently seen in diabetics.

ruber ruber [L.] red.

rubescent rubescent growing red; reddish.

rubidium rubidium chemical element (see Table of Elements), at. no. 37, symbol Rb. r. 82 r. 82 a radioactive isotope of rubidium having a halflife of 1.273 minutes and decaying by positron emission; used as a tracer in positron emission tomography.

Rubivirus Rubivirus rubella virus; a genus of viruses of the family Togaviridae containing the causative agent of rubella.

rubor rubor [L.] redness, one of the cardinal signs of inflammation.

rubra rubra [L.] red.

rubriblast proérythroblaste proerythroblast.

rubric rubrique red; specifically, pertaining to the red nucleus.

rubricyte rubricyte polychromatophilic erythroblast.

rubrospinal rubrospinal pertaining to the red nucleus and the spinal cord.

rubrothalamic rubrothalamique pertaining to the red nucleus and the thalamus.

Rubulavirus Rubulavirus a genus of viruses of the subfamily Paramyxovirinae (family Paramyxoviridae) containing a number of species that cause disease in humans and other animals.

rudiment rudiment 1. a structure that has remained undeveloped, or one with little or no function at present but which was functionally developed earlier. 2. primordium.

rudimentary rudimentaire 1. imperfectly developed. 2. vestigial.

rudimentum rudimentum pl. rudimenta [L.] rudiment.

ruga ride pl. rugae [L.] a ridge or fold. Adj.: rugose.

rugosity rugosité 1. a condition of being rugose. 2. a fold, wrinkle, or ruga.

RUL LSD right upper lobe (of lung).

rule règle a statement of conditions commonly observed in a given situation, or of a prescribed procedure to obtain a given result. Durham r. r. de Durham a definition of criminal responsibility from a federal appeals court case, Durham vs. United States, holding that “an accused is not criminally responsible if his unlawful act was the product of mental disease or mental defect.” In 1972 the same court reversed itself and adopted the American Law Institute Formulation. M’Naghten r. r. de M’Naghten a definition of criminal responsibility formulated in 1843 by English judges questioned by the House of Lords as a result of the acquittal of Daniel M’Naghten on grounds of insanity. It holds that “to establish a defense on the ground of insanity, it must be clearly proved that at the time of committing the act the party accused was laboring under such a defect of reason from disease of the mind as not to know the nature and quality of the act he was doing, or, if he did know it, that he did not know that what he was doing was wrong.” Nägele r. r. de Nägele (for predicting day of labor) subtract three months from the first day of the last menstruation and add seven days. r. of nines r. des neuf a method of estimating the extent of body surface that has been burned in an adult, dividing the body into sections of 9 per cent or multiples of 9 per cent. van’t Hoff r. r. de Van’t Hoff the velocity of chemical reactions is increased twofold or more for each rise of 10 °C in temperature; generally true only when temperatures approximate those normal for the reaction.

ruminant ruminant 1. chewing the cud. 2. one of the order of animals, including cattle, sheep, goats, deer, and antelopes, which have a stomach with four complete cavities (rumen, reticulum, omasum, abomasum), through which the food passes in digestion.

rumination rumination 1. the casting up of the food to be chewed thoroughly a second time, as in cattle. 2. in humans, the regurgitation of food after almost every meal, part of it being vomited and the rest swallowed: a condition sometimes seen in infants (rumination disorder) or in mentally retarded individuals. 3. rumination mentale repeated, excessive thinking about an event or situation.

rump croupe the buttock or gluteal region.

rupia rupia thick, dark, raised, lamellated, adherent crusts on the skin, somewhat resembling oyster shells, as in late recurrent secondary syphilis. Adj.: rupial.

rupture rupture 1. tearing or disruption of tissue. 2. déchirer to forcibly disrupt tissue. 3. hernia.

rush vague péristaltique peristaltic rush; a powerful wave of contractile activity that travels very long distances down the small intestine, caused by intense irritation or unusual distention.

ruthenium ruthénium chemical element (see Table of Elements), at. no. 44, symbol Ru.

rutherford rutherford a unit of radioactive disintegration, representing one million disintegrations per second.

RV VR residual volume.

RVA VAA rabies vaccine adsorbed; see rabies vaccine, under vaccine.

RVAD RVAD right ventricular assist device; see ventricular assist device, under device.

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