|Medical Dictionary - Dictionary of Medicine and Human Biology|
To make or become rancid.
The state of being rancid.
Gertrude, U.S. visual psychologist, 1886–1970. See Hardy-R.-Ritter test.
M.J., 20th century pharmacologist. See Burn and R. theory.
Alexander, U.S. urologist, *1883. See R. stone forceps.
Governed by chance; used of a process in which the outcome is indeterminate but may assume any of a set of values (the domain) with probabilities specifiable in advance. While the r. process is widely used in probability theory, empiric justification for the term is more complicated. The minimum requirement is that repeated realization of the process will settle down to a stable distribution or, if not metrical, a stable set of frequencies if the trait is classifiable only. See r. mechanism. [M.E. randon, speed, errancy, fr. O. Fr. randir, to run, fr. Germanic]
Allocation of individuals to groups, e.g., for experimental and control regimens, by chance.
Proprietary name for a finely powdered nickel catalyst made from Raney alloy by dissolving out the aluminum with alkali; used in the hydrogenation of organic substances. SYN: Raney catalyst.
A statistical measure of the dispersion or variation of values determined by the endpoint values themselves or the difference between them; e.g., in a group of children aged 6, 8, 9, 10, 13, and 16, the r. would be from 6 to 16 or, alternately, 10 (16 minus 6). [O.Fr. rang, line fr. Germanic] therapeutic r. refers to either the dosage r. or blood plasma or serum concentration usually expected to achieve desired therapeutic effects. Some patients will require doses (or concentrations) above or below this r.. Some patients will experience drug toxicity within this r..
1. Relating to the frog. 2. Relating to the undersurface of the tongue. [L. rana, a frog]
A histamine H2 antagonist used in the treatment of duodenal and gastric ulcers and gastroesophageal reflux, where it reduces hydrochloric acid secretion.
1. The ordinal position of an observation in the set of observations of which it is a member. 2. To order a set of observations according to their r..
Karl E. von, German chemist, 1870–1926. See R. formula.
Johannes, German anthropologist and physician, 1836–1916. See R. angle.
Fred Wharton, U.S. surgeon, 1886–1954. See R. clamp.
William J. McQ., Scottish physicist, 1820–1870. See R. scale.
Joseph, U.S. surgeon, 1853–1921. See R. sign.
A member of the interleukin-8 superfamily of cytokines. This cytokine is an 8-kD protein that is a selective chemoattractant for memory T lymphocytes and monocytes. [Regulated on activation, normal T expressed and secreted]
1. Hypoglottis. 2. Obsolete term for any cystic tumor of the undersurface of the tongue or floor of the mouth, especially one of the floor of the mouth due to obstruction of the duct of the sublingual glands. SYN: ptyalocele, ranine tumor, sialocele, sublingual cyst. [L. tadpole, dim. of rana, frog]
Relating to a ranula.
Louis A., French pathologist, 1835–1922. See R. crosses, under cross, R. disks, under disk, node of R., R. plexus, R. segment.
Abbreviation for right anterior oblique, a radiographic projection.
François, M., French physicist, 1830–1899. See R. law.
Abbreviation for rapid analysis of polymorphic DNA.
1. Sexual intercourse by force, duress, intimidation, or without legal consent (as with a minor). 2. The performance of such an act. [L. rapio, to seize, to drag away]
rapeseed oil (rap′sed)
The compressed oil from the seeds of Brassica campestris (family Cruciferae); used in the manufacture of soaps, margarine, and lubricants. [L. rapa, turnip]
A spasmodic disease supposed to be due to poisoning by the seeds of Rhaphanus rhaphanistrum, the wild radish. SYN: rhaphania.
raphe (ra′fe) [TA]
The line of union of two contiguous, bilaterally symmetrical structures. SYN: rhaphe. [G. rhaphe, suture, seam] amnionic r. the line of fusion of the amnionic folds over the embryo in reptiles, birds, and certain mammals. r. anococcygea SYN: anococcygeal ligament. anogenital r. in the male embryo the line of closure of the genital folds and swellings extending from the anus to the glans of the penis; it is differentiated in the adult into three regions: perineal r., scrotal r., and penile r.. r. corporis callosi a slight anteroposterior furrow on the median line of the upper surface of the corpus callosum. iliococcygeal r. [TA] portion of anococcygeal body formed by the attachment of the right and left halves of the iliococcygeus (muscle) to each other in the midline, posterior to the anal canal. SYN: r. musculi iliococcygeus [TA] . lateral palpebral r. a narrow fibrous band in the lateral part of the orbicularis oculi muscle formed by the interlacing of fibers passing through the upper and lower eyelids. SYN: palpebral r., r. palpebralis lateralis. r. linguae SYN: median sulcus of tongue. median longitudinal r. of tongue SYN: median sulcus of tongue. r. of medulla oblongata SYN: r. medullae oblongatae. r. medullae oblongatae [TA] the seamlike median zone of the medulla oblongata, marked by intercrossing fiber bundles among which lie scattered neuronal cell bodies. SYN: r. of medulla oblongata. r. musculi iliococcygeus [TA] SYN: iliococcygeal r.. r. palati [TA] SYN: palatine r.. palatine r. [TA] a rather narrow, low elevation in the center of the hard palate that extends from the incisive papilla posteriorly over the entire length of the mucosa of the hard palate. SYN: r. palati [TA] , palatine ridge. palpebral r. SYN: lateral palpebral r.. r. palpebralis lateralis SYN: lateral palpebral r.. penile r. SYN: r. of penis. r. penis [TA] SYN: r. of penis. r. of penis [TA] the continuation of the r. of the scrotum onto the underside of the penis. SYN: r. penis [TA] , penile r.. perineal r. [TA] the central anteroposterior line of the perineum, most marked in the male, being continuous with the r. of the scrotum. SYN: r. perinei [TA] . r. perinei [TA] SYN: perineal r.. pharyngeal r. [TA] the central line of the pharynx posteriorly where the muscular fibers meet and partly interlace. SYN: r. pharyngis [TA] . r. pharyngis [TA] SYN: pharyngeal r.. r. of pons SYN: r. pontis. r. pontis [TA] the continuation of the r. medullae oblongatae into the pars dorsalis (or tegmentum) pontis. SYN: r. of pons. pterygomandibular r. [TA] a tendinous thickening of the buccopharyngeal fascia, separating and giving origin to the buccinator muscle anteriorly and the superior constrictor of the pharynx posteriorly. SYN: r. pterygomandibularis [TA] , pterygomandibular ligament. r. pterygomandibularis [TA] SYN: pterygomandibular r.. r. retinae the horizontal line separating the superior and inferior portions of the temporal retina over which the retinal nerve fibers do not course. scrotal r. SYN: r. of scrotum. r. scroti [TA] SYN: r. of scrotum. r. of scrotum [TA] a central line, like a cord, running over the scrotum from the anus to the root of the penis; it marks the position of the septum scroti. SYN: r. scroti [TA] , scrotal r., Vesling line. Stilling r. the transverse interdigitations of fiber bundles across the anterior median fissure of the medulla oblongata at the decussation of the pyramidal tracts.
Samuel Mitja, Russian biochemist, 1912–1977. See R.-Luebering shunt.
Abraham, Canadian urologist, *1926. See R. test.
Henry, U.S. pathologist, *1913. See R. classification.
1. A feeling of relationship, especially when characterized by emotional affinity. 2. A conscious feeling of harmonious accord, trust, empathy, and mutual responsiveness between two or more persons ( e.g., physician and patient) that fosters the therapeutic process. [Fr.]
rapture of the deep (rap′choor)
SYN: nitrogen narcosis (2) .
1. The process of becoming light or less dense; the condition of being light; opposed to condensation. 2. In vascular physiology, the process that results in a reduction in the density of capillaries in a tissue. [L. rarus, thin, scanty + facio, to make]
To become light or less dense.
Abbreviation for reticular activating system.
The transverse wrinkling on the anterior surface of the wrist. [Mod. L. raseta, fr. Ar. rahah, the palm of the hand]
Lay term for a cutaneous eruption. [O. Fr. rasche, skin eruption, fr. L. rado, pp. rasus, to scratch, scrape] antitoxin r. a cutaneous manifestation of serum sickness. black currant r. the cutaneous eruption of lentigines seen in xeroderma pigmentosum. butterfly r. SYN: butterfly (2) . caterpillar r. SYN: caterpillar dermatitis. crystal r. SYN: miliaria crystallina. diaper r. SYN: diaper dermatitis. heat r. SYN: miliaria rubra. hydatid r. a toxic eruption occasionally following the rupture of a hydatid cyst. Murray Valley r. SYN: epidemic polyarthritis. serum r. a cutaneous manifestation of serum sickness. summer r. SYN: miliaria rubra. wildfire r. SYN: miliaria rubra.
The subdivision of a crude drug by a rasp to prepare it for extraction. [L. rasio, a scraping, fr. rado, pp. rasus, to scrape, shave]
Grant L., American neuroanatomist, *1904. See bundle of R., r. encephalitis, R. syndrome.
Fritz W., Danish physician, 1834–1881. See R. aneurysm.
A surgical instrument used to smooth the edges of a divided bone. [L. raspatorium]
Acronym for radioallergosorbent test.
Gian C. See R. operation.
A rodent of the genus Rattus (family Muridae), involved in the spread of some diseases, including bubonic plague. albino rats rats with white fur and pink eyes; used extensively in laboratory experiments. Wistar rats an inbred strain of rats, homozygous at most loci, produced by strict brother-sister inbreeding over many generations to develop animals for research with the same general genetic composition. [Wistar Institute]
1. A record of the measurement of an event or process in terms of its relation to some fixed standard; measurement is expressed as the ratio of one quantity to another ( e.g., velocity, distance per unit time). 2. A measure of the frequency of an event in a defined population; the components of a r. are: the numerator (number of events); the denominator (population at risk of experiencing the event); and the specified time in which the events occur. [L. ratum, a reckoning (see ratio)] abortion r. 1. the number of induced abortions per 1000 preganancies that resulted in a livebirth, stillbirth, or induced termination. 2. the number of terminations ×1000 ÷ the female population ages 15–44 years. age-specific r. a r. for a specified age group, in which the numerator and denominator refer to the same age group. attack r. a cumulative incidence r. used for particular groups observed for limited periods under special circumstances, such as during an epidemic. average flow r. the flow r. determined by dividing the total volume of urine passed by the time of voiding. basal metabolic r. (BMR) SYN: basal metabolism. baseline fetal heart r. the average heart r. for a particular fetus during the diastolic phase of uterine contractions. birth r. a summary r. based on the number of live births in a population over a given period, usually 1 year; the numerator is the number of live births, the denominator is the midyear population. case fatality r. the proportion of individuals contracting a disease that die of that disease. concordance r. the proportion of a random sample of pairs that are concordant for a trait of interest. A high r. of concordance may be generated in several ways, many of which may result from irrelevant bias; but broadly it is taken as evidence of causal connection ( e.g., in the case of identical twins, a genetic component or in spouses of assortative mating). critical r. a heart r. at which aberration or incomplete block will occur; a result of shortening of cycle length so that it barely includes the refractory period. death r. an estimate of the proportion of the population that dies during a specified period, usually a year; the numerator is the number of people dying, the denominator is the number in the population, usually an estimate of the number at the midperiod. SYN: crude death r., lethality r., mortality r., mortality (2) . erythrocyte sedimentation r. (ESR) the r. of settling of red blood cells in anticoagulated blood; increased rates are often associated with anemia or inflammatory states. fatality r. the death r. observed in a designated series of persons affected by a simultaneous event such as a disaster. fetal death r. the number of fetal deaths divided by the sum of live births and fetal deaths occurring in the same population during the same time period. SYN: stillbirth r.. fetal heart r. in the fetus, the number of heart beats per minute, normally 120–160. five-year survival r. the proportion of patients still alive five years after a diagnosis or form of treatment is completed. Usually applied to statistics of survival of cancer patients, since, after five years, recurrences are much less likely to occur. general fertility r. a refined measure of fertility in a population; the numerator is the number of live births in a year, the denominator is the number of females of child-bearing age, usually defined as ages 15–44 (but increasingly recognized as extending to age 49). glomerular filtration r. (GFR) the volume of water filtered out of the plasma through glomerular capillary walls into Bowman capsules per unit time; it is considered to be equivalent to inulin clearance. gross reproduction r. the average number of female children a woman would have if she survived to the end of her childbearing years and if, throughout that period, she were subject to a given set of age-specific fertility rates and a given sex ratio at birth; this r. provides a measure of the replacement fertility of a population in the absence of mortality. growth r. absolute or relative growth increase, expressed per unit of time. growth r. of population a measure of population change in the absence of migration, comprising addition of newborns and subtraction of deaths; the result is known as the natural r. of increase of the population; it is the difference between the crude birth r. and the crude death r.. hazard r. theoretical measure of the risk of occurrence of an event, e.g., death, new disease, at a point in time. heart r. r. of the heart's beat, recorded as the number of beats per minute. inception r. the r. at which new spells of illness or cases of a condition occur in a population. incidence r. the r. at which new events occur in a population. The numerator is the number of new events occurring in a defined period; the denominator is the population at risk of experiencing the event during this period. infant mortality r. a measure of the r. of deaths of liveborn infants before their first birthday; the numerator is the number of infants under one year of age born alive in a defined region during a calendar year who die before they are one year old; the denominator is the total number of live births; often quoted as a useful indicator of the level of health in a community. initial r. SYN: initial velocity. lethality r. SYN: death r.. maternal death r. the number of maternal deaths that occur as the direct result of the reproductive process per 100,000 live births. See r.. SEE ALSO: maternal death. SYN: maternal mortality ratio. mitotic r. the proportion of cells in a tissue that are undergoing mitosis, expressed as a mitotic index or, roughly, as the number of cells in mitosis in each microscopic high-power field in tissue sections. morbidity r. the proportion of patients with a particular disease during a given year per given unit of population. mortality r. SYN: death r.. mucociliary clearance r. velocity of movement of the mucus blanket over respiratory epithelium, usually expressed in mm/hour. mutation r. the probability (or proportion) of progeny genes with a particular component of the genome not present in either biologic parent; usually expressed as the number of mutants per generation occurring at one gene or locus. neonatal mortality r. the number of deaths in the first 28 days of life divided by the number of live births occurring in the same population during the same period of time. peak flow r. maximum urinary flow r. during voiding as measured by a uroflowmeter. perinatal mortality r. the number of stillborn infants of 24 completed weeks or more plus the number of deaths occurring under 28 days of life divided by the number of stillborn infants of 24 weeks or more gestation plus all liveborn infants in the same population, regardless of the period of gestation. pulse r. r. of the pulse as observed in an artery; recorded as beats per minute. recurrence r. in genetic counseling, the risk that a future offspring will be affected given some specific set of relatives of whom at least one is already affected. repetition r. the number of pulses per minute, describing an energy output, e.g., ultrasound pulses in echocardiography rather than vascular pulses. respiratory r. frequency of breathing, recorded as the number of breaths per minute. sedimentation r. the r. at which a sediment is deposited from a solution. SEE ALSO: erythrocyte sedimentation r.. shear r. the change in velocity of parallel planes in a flowing fluid separated by unit distance; its units expressed in seconds−1. slew r. in electronic pacemaker function, the maximum r. of change of an amplifier output voltage; important variable affecting heart function as controlled by an electronic pacemaker. Sensing circuits in the pacemaker often respond to the slew r. rather than to the absolute amplitude of the voltage pulse. steady-state r. SYN: steady-state velocity. steroid metabolic clearance r. (MCR) a measure of the r. of metabolism of a given steroid within the body, usually expressed as liters of body fluid that contain the amount of steroid metabolized per day. steroid production r. the total quantity of a given steroid formed in the body, usually expressed as milligrams per day; represents the sum of the glandular secretion of the steroid and extraglandular formation of it from various steroid precursors. steroid secretory r. the r. of glandular secretion of a given steroid, usually expressed as milligrams per day; does not include any amount of the steroid that might be formed extraglandularly. stillbirth r. SYN: fetal death r.. voiding flow r. urinary flow as a function of time during micturition, as graphically recorded by a flow meter.
Martin H., German anatomist, physiologist, and pathologist, 1793–1860. See R. bundles, under bundle, R. cleft cyst, R. diverticulum, R. pocket, R. pouch, R. pouch tumor.
rating of perceived exertion
Subjective numerical rating (range 6–19) of exercise intensity based on how an individual feels in relation to level of physiologic stress. An RPE of 13 or 14 (exercise that feels “somewhat hard”) coincides with an exercise heart rate of about 70% maximum.
An expression of the relation of one quantity to another ( e.g., of a proportion or rate). SEE ALSO: index (2) , quotient. [L. r. (ration-) a reckoning, reason, fr. reor, pp. ratus, to reckon, compute] absolute terminal innervation r. the number of motor endplates divided by the number of terminal axons related to them. accommodative convergence-accommodation r. (AC/A) the amount of convergence (measured in prism diopters of convergence) divided by the amount of accommodation (measured in diopters) required to direct both eyes upon an object. A/G r. abbreviation for albumin-globulin r.. albumin-globulin r. (A/G r.) the r. of albumin to globulin in the serum or in the urine in kidney disease; the normal r. in the serum is approximately 1.55. ALT:AST r. the r. of serum alanine aminotransferase to serum aspartate aminotransferase; elevated serum levels of both enzymes characterize hepatic disease; when both levels are abnormally elevated and the ALT:AST r. is greater than 1.0, severe hepatic necrosis or alcoholic hepatic disease is likely; when the r. is less than 1.0, an acute nonalcoholic hepatic condition is favored. amylase-creatinine clearance r. a test for the diagnosis of acute pancreatitis; it is determined by measuring amylase and creatinine in serum and urine; in apparently healthy individuals the renal clearance of amylase is less than 5% that of creatinine; in acute pancreatitis the r. is said to be greater than 5%. body-weight r. body weight (in grams) divided by stature (in centimeters). cardiothoracic r. the r. of the horizontal diameter of the heart to the inner diameter of the rib cage at its widest point as determined on a chest roentgenogram. case fatality r. the mortality rate of a disease, usually expressed per 100 cases. r. of decayed and filled surfaces (RDFS) an index of decayed and filled permanent surfaces per person, per full complement of 122 tooth surfaces. r. of decayed and filled teeth (RDFT) an index of decayed and filled permanent teeth per person, per full complement of 28 teeth. extraction r. (E) the fraction of a substance removed from the blood flowing through the kidney; it is calculated from the formula (A —V)/A, where A and V, respectively, are the concentrations of the substance in arterial and renal venous plasma. fertility r. a measure of the fertility of a population based on the female population in the child-bearing age group, defined as ages 15–49 years. flux r. the r. of the two unidirectional fluxes through a particular boundary layer or membrane. functional terminal innervation r. the number of muscle fibers divided by the number of axons that innervate them. grid r. in a radiographic scatter-absorbing grid, the r. of the height to the width of the gaps between lead strips; a higher grid r. removes more scattered radiation but requires more careful x-ray tube positioning to avoid grid cutoff of the primary radiation beam. gyromagnetic r. in nuclear magnetic resonance, the r. of the magnetic dipole moment of the nucleus to the nuclear spin angular momentum; the gyromagnetic r. is a unique value for each type of nucleus. SYN: magnetogyric r.. hand r. the r. of the length of the hand (measured on the dorsum from the styloid process of the ulna to the tip of the third finger) to the width across the knuckles. international normalized r. (INR) the prothrombin time r. that would have been obtained if a standard reagent had been used in a prothrombin time determination; the prothrombin time r. is expressed as the patient prothrombin time divided by the mean of the prothrombin time reference interval; the prothrombin time r. is obtained for a working reagent in the laboratory through use of a parameter designated the international sensitivity index. SEE ALSO: international sensitivity index. IRI/G r. the r. of immunoreactive insulin to serum or plasma glucose; in hypoglycemic states a r. of less than 0.3 is usual, with the exception of the hypoglycemia due to insulinoma, where the r. is often higher than 0.3. K:A r. abbreviation for ketogenic-antiketogenic r.. ketogenic-antiketogenic r. (K:A r.) the proportion between substances that form ketones in the body and those that form d-glucose. lecithin/sphingomyelin r. (L/S r.) a r. used to determine fetal pulmonary maturity, found by testing the amniotic fluid; when the lungs are mature, lecithin exceeds sphingomyelin by 2 to 1. L/S r. abbreviation for lecithin/sphingomyelin r.. magnetogyric r. (mag′ne-to-gy-rik) SYN: gyromagnetic r.. mass-action r. the r. of the product of all of the product concentrations divided by the product of all of the reactant concentrations of a particular reaction; when the reaction has been completed ( i.e., t = ∞), then this r. is equal to the equilibrium constant. maternal mortality r. SYN: maternal death rate. M:E r. the r. of myeloid to erythroid precursors in bone marrow; normally it varies from 2:1 to 4:1; an increased r. is found in infections, chronic myelogenous leukemia, or erythroid hypoplasia; a decreased r. may mean a depression of leukopoiesis or normoblastic hyperplasia depending on the overall cellularity of the bone marrow. mendelian r. the r. of progeny with particular phenotypes or genotypes expected in accordance with Mendel law among the offspring of matings specified as to genotype or phenotype. molecular weight r. (Mr) SYN: molecular weight. nuclear-cytoplasmic r. r. of volume of nucleus to volume of cytoplasm, fairly constant for a particular cell type and usually increased in malignant neoplasms. nucleolar-nuclear r. r. of volume of nucleolus to volume of nucleus, usually increased in malignant neoplasms. P/O r. a measure of oxidative phosphorylation; the r. of phosphate radicals esterified (forming adenosine 5′-triphosphate from adenosine 5′-diphosphate) to atoms of oxygen consumed by mitochondria; normally, the r. is 3 (starting from NADH). SYN: P/O quotient. respiratory exchange r. the r. of the net output of carbon dioxide to the simultaneous net uptake of oxygen at a given site, both expressed as moles or STPD volumes per unit time; in the steady state, respiratory exchange r. is equal to the respiratory quotient of metabolic processes. segregation r. in genetics, the proportion of progeny of a particular genotype or phenotype from actual matings of specified genotypes. The test of a mendelian hypothesis is the comparison of the segregation rate with the mendelian rate. sex r. 1. the r. of male to female progeny at some specified stage of the life cycle, notably at conception (primary), at birth (secondary), or at any stage between birth and death (tertiary); 2. the r. of the numbers of males to females affected by a particular disease or trait. signal-to-noise r. the relative intensity of a signal to the random variation in signal intensity, or noise; used to evaluate many imaging techniques and electronic systems. standardized mortality r. the r. of the number of events observed in a population to the number that would be expected if the population had the same distribution as a standard or reference population. systolic/diastolic r. a calculation from pulsed Doppler ultrasound determinations of blood flow velocities that reflects intrinsic resistance in an arterial blood vessel. therapeutic r. the r. of the maximally tolerated dose of a drug to the minimal curative or effective dose; LD50 divided by ED50. variance r. (F) the distribution of the r. of two independent estimates of the same variance from a gaussian distribution based on samples of sizes (n + 1) and (m + 1), respectively. Estimates are usually based on one such sample analyzed in such a way as to make them independent, e.g., analysis of variance, and F may be used to test a null hypothesis that the observed differences among sample means is no greater than could readily be accounted for by chance. ventilation/perfusion r. (Va/Q) the r. of alveolar ventilation to simultaneous alveolar capillary blood flow in any part of the lung; because both ventilation and perfusion are expressed per unit volume of tissue and per unit time, which cancel, the units become liters of gas per liter of blood. waist-hip r. r. of the abdominal circumference at the navel to maximum hip and buttocks circumference. zeta sedimentation r. (ZSR) the r. of the zetacrit to the hematocrit, normally 0.41–0.54 (41–54%); it is a sensitive indicator of the erythrocyte sedimentation rate (ESR) and, unlike the latter, is unaffected by anemia, which tends to elevate the ESR.
1. Pertaining to reasoning or to the higher thought processes; based on objective or scientific knowledge, in contrast to empiric (1). 2. Influenced by reasoning rather than by emotion. 3. Having the reasoning faculties; not delirious or comatose. [L. rationalis, fr. ratio, reason]
A postulated psychoanalytic defense mechanism through which irrational behavior, motives, or feelings are made to appear reasonable. [L. ratio, reason]
See Kurzrok-R. test.
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