|Medical Dictionary - Dictionary of Medicine and Human Biology|
A woman who has never borne a child. [L. nullus, none, + pario, to bear]
Condition of having borne no children.
Never having borne a child. SYN: nonparous.
1. A symbol expressive of a certain value or of a specific quantity determined by count. 2. The place of any unit in a series. atomic n. (Z) the n. of protons in the nucleus of an atom; it indicates the position of the element in the periodic system. Avogadro n. (Λ, NA) the n. of molecules in 1 gram-molecular weight (1 mol) of any compound; defined as the n. of atoms in 0.0120 kg of pure carbon-12; equivalent to 6.0221367 × 1023. SYN: Avogadro constant. Brinell hardness n. (BHN) a n. related to the size of the permanent impression made by a ball indenter of specified size (usually 10 mm in diameter) pressed into the surface of the material under a specified load: where P = applied load in kg, D = diameter of the ball in mm, and d = diameter of the impression in mm. CT n. a normalized value of the calculated x-ray absorption coefficient of a pixel (picture element) in a computed tomogram, expressed in Hounsfield units, where the CT n. of air is −1000 and that of water is 0. SYN: Hounsfield n.. electronic n. the n. of electrons in the outermost orbit (valence shell) of an element. gold n. SYN: gold equivalent. Hehner n. the weight or percentage of the nonvolatile fatty acids yielded by 5 g of a saponified fat or oil. SYN: Hehner value. Hogben n. unique personal identifying n. constructed by using a sequence of digits for birth date, sex, birthplace, and other identifiers; invented by and named for Lancelot Hogben, British mathematician; Hogben numbers are the basis for identification numbers in many primary care facilities and are used in many record linkage systems. Hounsfield n. SYN: CT n.. hydrogen n. the quantity of hydrogen that 1 g of fat will absorb; it is a measurement of the amount of unsaturated fatty acids in the fat. SEE ALSO: iodine n.. iodine n. an indication of the quantity of unsaturated fatty acids present in a fat; it represents the n. of grams of iodine absorbed by each 100 g of fat. SEE ALSO: hydrogen n.. SYN: iodine value. Kestenbaum n. the difference between the two pupil diameters when each eye is measured in bright light with the other eye tightly covered; an indicator of the relative afferent pupillary defect in patients with two normally innervated irises. Knoop hardness n. (KHN) a n. obtained by dividing the load in kg applied to a pyramid-shaped diamond of specific size divided by the projected area of the impression: KHN = L/A, where A= the projected area of the impression in mm2 and L = the load in kg; used for measurements of hardness of any materials, especially very hard and brittle substances such as tooth dentin and enamel. Koettstorfer n. SYN: saponification n.. linking n. (L) a property of a long biopolymer (such as duplex DNA) equal to the n. of twists (related to the frequency of turns around the central axis of the helix) plus the writhing n.. Loschmidt n. (n0) the n. of molecules in 1 cm3 of ideal gas at 0°C and 1 atm of pressure; Avogadro n. divided by 22,414 ( i.e., 2.6868 × 1019 cm−3). Mach n. a n. representing the ratio between the speed of an object moving through a fluid medium, such as air, and the speed of sound in the same medium. mass n. the mass of the atom of a particular isotope relative to hydrogen-1 (or to 112 the mass of carbon-12), generally very close to the whole n. represented by the sum of the protons and neutrons in the atomic nucleus of the isotope (indicated in the name or symbol of the isotope; e.g., oxygen-16, 16O); not to be confused with the atomic weight of an element, which may include a n. of isotopes in natural proportion. MIM n. the catalog assignment for a mendelian trait in the MIM system. If the initial digit is 1, the trait is deemed autosomal dominant; if 2, autosomal recessive; if 3, X-linked. Wherever a trait defined in this dictionary has a MIM n., the n. from the 12th edition of MIM, is given in square brackets with or without an asterisk (asterisks indicate that the mode of inheritance is known; a n. symbol (#) before an entry n. means that the phenotype can be caused by mutation in any of 2 or more genes) as appropriate e.g., Pelizaeus-Merzbacher disease [MIM*169500] is a well-established, autosomal, dominant, mendelian disorder. Polenské n. the n. of milliliters of 0.1 n KOH required to neutralize the nonvolatile fatty acids obtained from 5 g of a saponified fat or oil. Reichert-Meissl n. an index of the volatile acid content of a fat; the n. of milliliters of 0.1 n KOH required to neutralize the soluble volatile fatty acids in 5 g of fat that has been saponified, acidified to liberate the fatty acids, and then steam-distilled. SYN: volatile fatty acid n.. Reynolds n. a dimensionless n. that describes the tendency for a flowing fluid, such as blood, to change from laminar flow to turbulent flow or vice versa. saponification n. the n. of milligrams of KOH required to saponify 1 g of fat; an approximate measure of the average molecular weight of a fat, with which it varies inversely. SYN: Koettstorfer n.. stoichiometric n. (ν) the n. associated with a reactant or product participating in a defined chemical reaction; usually an integer. thiocyanogen n. the n. of grams of thiocyanogen taken up by 100 g of fat; analogous to the iodine n., except that thiocyanogen will not add to all the double bonds in polyunsaturated fatty acids, as will iodine. SYN: thiocyanogen value. transport n. the fraction of the total current carried through a solution by a particular type of ion present in that solution. turnover n. (kcat) the n. of substrate molecules converted into product in an enzyme-catalyzed reaction under saturating conditions per unit time per unit quantity of enzyme; e.g., kcat = Vmax/[Etotal]. volatile fatty acid n. SYN: Reichert-Meissl n.. wave n. the n. of waves (of any waveform such as light or sound) per unit length. writhing n. the n. of times a DNA duplex axis crosses over itself in space.
Indefinite term for abnormal sensation, including absent or reduced sensory perception as well as paresthesias.
1. Discoid or coin-shaped; denoting the thick mucous or mucopurulent sputum in certain respiratory diseases, so called because of the disc shape assumed when it is flattened on the bottom of a sputum mug containing water or transparent disinfectant. 2. Arranged like stacks of coins, denoting the lining up of the red blood cells into rouleaux formation. SYN: nummiform. [ L. nummulus, small coin, dim. of nummus, coin]
Formation of nummular masses.
A speech disorder in which the n sound is given to other consonants. [Ar. nun, the letter n.]
1. To breast feed. 2. To provide care of the sick. 3. One who is educated in the scientific basis of nursing under defined standards of education and is concerned with the diagnosis and treatment of human responses to actual or potential health problems. [O. Fr. nourice, fr. L. nutrix, wet-n., n., fr. nutrio, to sucke, to tend] certified registered n. anesthetist (C.R.N.A.) a registered professional n. with additional education in the administration of anesthetics. Certification achieved through a program of study recognized by the American Association of N. Anesthetists. charge n. a n. administratively responsible for a designated hospital unit, usually on an 8-hour basis. SYN: head n. (2) . clinical n. specialist a registered n. with at least a master's degree who has advanced education in a particular area of clinical practice such as oncology or psychiatry. Usually employed in a hands-on clinical setting such as a hospital. community n. SYN: public health n.. community health n. SYN: public health n.. dry n. a woman who cares for newborn infants without breast feeding them, as opposed to a wet n.. n. epidemiologist a registered n. with additional education in the monitoring and prevention of nosocomial infections in the client population in an agency. SYN: infection control n.. flight n. a n. who cares for clients during transport in any type of aircraft. general duty n. n. who accepts assignment to any unit of a hospital other than an intensive care unit. graduate n. a n. who has received a degree, most often a bachelor's degree, from a school or college of nursing. head n. 1. a n. administratively responsible for a designated hospital unit on a 24 hour basis; 2. SYN: charge n.. home health n. a n. who is responsible for a group of clients in the home setting. Visits clients on a routine basis to assist client and family with care as needed and to teach family the care needed so that the client may remain in his/her home. SYN: visiting n.. hospital n. a registered n. working in a hospital. infection control n. SYN: n. epidemiologist. licensed practical n. (L.P.N.) a n. who has graduated from an accredited school of practical (vocational) nursing, passed the state examination for licensure, and been licensed to practice by a state authority. Program is generally 1 year in length. SYN: licensed vocational n.. licensed vocational n. (L.V.N.) SYN: licensed practical n.. practical n. a graduate of a specific educational program that prepares the individual for a career in nursing with less responsibility than a graduate or registered n.. private n. SYN: private duty n.. private duty n. 1. a n. who is not a member of a hospital staff, but is hired by the client or his/her family on a fee-for-service basis to care for the client; 2. a n. who specializes in the care of patients with diseases of a particular class, e.g., surgical cases, tuberculosis, children's diseases. SYN: private n.. public health n. a n. who provides care to individuals or groups in a community outside of institutions. Usually works through the auspices of a state or city health department. SYN: community health n., community n.. registered n. (R.N.) a n. who has graduated from an accredited nursing program, has passed the state examination for licensure, and has been registered and licensed to practice by a state authority. school n. a n., usually an RN, working in a school or similar institution. scrub n. a n. who has scrubbed arms and hands, donned sterile gloves and, usually, a sterile gown, and assists an operating surgeon, primarily by passing instruments. special n. a n., who might be a registered n. or a practical n., assigned to limited, specialized functions; usually synonymous with private duty n.. student n. a student in a program leading to certification in a form of nursing; usually applied to students in an RN or practical n. program. visiting n. SYN: home health n.. wet n. a woman who breast feeds a child not her own.
nurse practitioner (ners prak-tish′u-ner)
A registered nurse with at least a master's degree in nursing and advanced education in the primary care of particular groups of clients; capable of independent practice in a variety of settings.Nurse practitioners have been recognized in the U.S. since 1955. State laws regulate their scope of practice and degree of autonomy. By assuming responsibility for preventive care, health education, routine surveillance, and the management of chronic disorders, nurse practitioners free physicians to render more sophisticated or elaborate diagnostic and therapeutic services. In thinly populated areas they enable patients to receive treatment for most medical problems without having to travel long distances. Some observers have noted that the pursuit by nurse practitioners of increasing autonomy and their popularity with managed care organizations threaten to diminish the quality of primary medical care.
1. Feeding an infant at the breast; tending and caring for a child. 2. The scientific application of principles of care related to prevention of illness and care during illness. n. assignment the method(s) by which the patient care load is distributed among the n. personnel available to provide care. n. audit a defined procedure used to evaluate the quality of n. care provided within an agency to its clients. n. model a set of abstract and general statements about the concepts that serve to provide a framework for organizing ideas about clients, their environment, health, and n.. n. plan of care the written framework that provides direction for the delivery of n. care. n. process a five-part systematic decision-making method focusing on identifying and treating responses of individuals or groups to actual or potential alterations in health. Includes assessment, n. diagnosis, planning, implementation, and evaluation. The first phase of the n. process is assessment, which consists of data collection by such means as interviewing, physical examination, and observation. It requires collection of both objective and subjective data. The second phase is n. diagnosis, a clinical judgment about individual, family or community n. responses to actual or potential health problems/life processes. Provides the basis for selection of n. intervention to achieve outcomes for which the nurse is accountable (NANDA, 1990). The third phase is planning, which requires establishment of outcome criteria for the client's care. The fourth phase is implementation (intervention). This phase involves demonstrating those activities that will be provided to and with the client to allow achievement of the expected outcomes of care. Evaluation is the fifth and final phase of the n. process. It requires comparison of client's current state with the stated expected outcomes and results in revision of the plan of care to enhance progress toward the stated outcomes.
A convalescent home or private facility for the care of individuals who do not require hospitalization and who cannot be cared for at home.
Johann H.R. von, German surgeon, 1829–1890.
The act of nodding, especially involuntary nodding. [L. annuo, to nod]
An excrescence on the oak, Quercus infectoria (family Fagaceae) and other species of Quercus, caused by the deposit of the ova of a fly, Cynips gallae tinctorae; an astringent and styptic, by virtue of the tannin it contains. SYN: gall (3) , galla, oak apple.
The dried ripe seed of Myristica fragrans (family Myristicaceae), deprived of its seed coat and arillode; an aromatic stimulant, carminative, condiment, and source of volatile and expressed n. oils; it is consumed for its bizarre central nervous system effects. SEE ALSO: myristicin. SYN: myristica.
The volatile oil distilled from the dried kernels of the ripe seeds of Myristica fragrans; used as a flavoring agent and a carminative; in large quantities, it may produce narcosis and delirium; the fixed oil expressed from M. fragrans is used as a rubefacient. SYN: myristica oil.
A constituent of food necessary for normal physiologic function. [L. nutriens, fr. nutrio, to nourish] essential nutrients nutritional substances required for optimal health. These must be in the diet, because they are not formed metabolically within the body. trace n. SYN: micronutrients.
Essential nutritional factors. [L. nutrio, to suckle, nourish]
1. A function of living plants and animals, consisting in the taking in and metabolism of food material whereby tissue is built up and energy liberated. SYN: trophism (2) . 2. The study of the food and liquid requirements of human beings or animals for normal physiologic function, including energy, need, maintenance, growth, activity, reproduction, and lactation. [L. nutritio, fr. nutrio, to nourish] total parenteral n. (TPN) n. maintained entirely by central intravenous injection or other nongastrointestinal route.
1. Pertaining to nutrition. 2. Capable of nourishing. SYN: alible.
State or condition of the nutrition of the body; state of the body with regard to nourishment. [L. nutritura, a nursing, fr. nutrio, to nourish]
G. H. F., U.S. biologist, 1862–1937. See Nuttallia.
Former name for Babesia.
nux vomica (nuks vom′i-ka)
Poison nut or Quaker button, the seed of Strychnos nux-vomica (family Logeniaceae), a tree of tropical Asia; it contains two alkaloids, strychnine and brucine; it has been used as a bitter tonic and central nervous system stimulant. [Mod. L. emetic nut, fr. L. nux, nut, + vomo, to vomit]
Abbreviation for norvaline.
Denoting especially the osteocopic pains of syphilis occurring at night. SYN: night pain. [nyct- + G. algos, pain]
Decreased ability to see in reduced illumination. Seen in patients with impaired rod function; often associated with a deficiency of vitamin A. SYN: day sight, night blindness, nocturnal amblyopia, nyctanopia. [nyct- + G. alaos, obscure, + ops, eye] n. with congenital myopia [MIM*310500] an abnormality of X-linked inheritance characterized by low visual acuity, strabismus, or nystagmus.
SYN: nyctalopia. [nyct- + G. an- priv. + opsis, sight]
nycterine (nik′ter-in, -in)
1. By night. 2. Dark or obscure. [G. nykterinos]
SYN: nyctohemeral. [G. nykteros, by night, nightly, + hemera, day]
Night, nocturnal. SEE ALSO: noct-. [G. nyx]
Both daily and nightly. SYN: nycterohemeral. [nycto- + G. hemera, day]
Preference for the night or darkness. SYN: scotophilia. [nycto- + G. philos, fond]
Morbid fear of night or of the dark. SYN: scotophobia. [nycto- + G. phobos, fear]
A genus of Ciliophora, one species of which, N. faba, has been reported, though rarely, from the human intestine; it is generally found in amphibia. [G. nyktotheras, one who hunts by night, fr. therao, to hunt, fr. ther, wild beast]
William L. U.S. pediatrician, *1926. See Lesch-N. syndrome.
nylidrin hydrochloride (ni′li-drin, nil′)
A sympathomimetic agent, similar to isoproterenol, that produces vasodilation of arterioles of skeletal muscles and increases muscle blood flow; used in the treatment of peripheral vascular diseases.
1. The earliest series of stages in metamorphosis following hatching in the development of hemimetabolous insects ( e.g., locusts); the n. resembles the adult in many respects, but lacks full wing or genitalia development; it grows through successive instars without any intermediate or pupal stage into the imago or adult form. SEE ALSO: incomplete metamorphosis, complete metamorphosis. 2. The third stage in the life cycle of a tick, between the larva and the adult. [G. nymphe, maiden]
nympha, pl .nymphae (nim′fa, nim′fe)
One of the labia minora. [Mod. L., fr. G. nymphe, a bride]
1. Pertaining to a nymph. 2. Pertaining to the labia minora (nymphae).
Surgical removal of hypertrophied labia minora. [nympha + G. ektome, excision]
Inflammation of the labia minora. [nympha + G. -itis, inflammation]
The nymphae (labia minora). [L. nympha]
Relating to the labia minora (nymphae) and the labia majora; denoting a furrow between the two labia on each side.
Demoniac frenzy, especially of an erotic nature. [nympho- + G. lepsis, a seizure]
An insatiable impulse to engage in sexual behavior in a female; the counterpart of satyriasis in a male. [nympho- + G. mania, frenzy]
A female exhibiting nymphomania.
Pertaining to, or exhibiting, nymphomania.
Swelling or hypertrophy of one or both labia minora. [nympho- + G. onkos, tumor]
Incision into the labia minora or the clitoris. [nympho- + G. tome, incision]
Relating to or suffering from nystagmus.
The tracing produced by a nystagmograph.
An apparatus for measuring the amplitude, periodicity, and velocity of ocular movements in nystagmus, by measuring the change in the resting potential of the eye as the eye moves. [nystagmus + G. grapho, to write]
The technique of recording nystagmus.
Resembling nystagmus. SYN: nystagmiform. [nystagmus + G. eidos, resemblance]
Involuntary rhythmic oscillation of the eyeballs, either pendular or with a slow and fast component. [G. nystagmos, a nodding, fr. nystazo, to be sleepy, nod] after-n. n. occurring after the abrupt cessation of rotation in the opposite direction of the rotatory n.. amaurotic n. SYN: ocular n.. Bruns n. a fine, jerking (vestibular) n. on horizontal gaze in one direction, together with a slower, larger amplitude (gaze, paretic) n. on looking in the opposite direction; due to lateral brainstem compression, usually by a cerebellar-pontine angle mass such as an acoustic neuroma. caloric n. n. with slow and fast components induced by labyrinthine stimulation with warm or cool water in the ear. SEE ALSO: Bárány sign. cervical n. n. arising from a lesion of the proprioceptive mechanism of the neck. compressive n. a jerky n. resulting from unilateral changes of pressure in semicircular canals. congenital n. 1. n. present at birth or caused by lesions sustained in utero or at the time of birth; 2. inherited n., usually X-linked, without associated neurologic lesions and nonprogressive; all three patterns of mendelian inheritance may occur: autosomal dominant [MIM*164100, *164150], autosomal recessive [MIM*257400], or X-linked recessive [MIM*310800, *310700]; 3. the n. associated with albinism, achromatopsia, and hypoplasia of the macula. conjugate n. a n. in which the two eyes move simultaneously in the same direction. convergence-retraction n. irregular, jerky n. combining convergence and retraction of the eye into the orbit, especially on attempting an upward gaze. SYN: Koerber-Salus-Elschnig syndrome. deviational n. SYN: end-point n.. dissociated n. a n. in which the movements of the two eyes are dissimilar in direction, amplitude, and periodicity. SYN: dysjunctive n., incongruent n., irregular n.. downbeat n. a vertical n. with a rapid component downward, occurring in lesions of the lower part of the brainstem or cerebellum. dysjunctive n. SYN: dissociated n.. end-point n. a jerky, physiologic n. occurring in a normal individual when attempts are made to fixate a point at the limits of the field of fixation. SYN: deviational n.. fast component of n. compensatory movement of the eyes in the vestibuloocular reflex. fixation n. n. aggravated or induced by ocular fixation, arising as optokinetic n., or resulting from midbrain lesions. galvanic n. n. involving galvanic stimulation of the labyrinth. gaze paretic n. a n. occurring in partial gaze paralysis when an attempt is made to look in the direction of the gaze paresis. incongruent n. SYN: dissociated n.. irregular n. SYN: dissociated n.. jerky n. n. in which there is a slow drift of the eyes in one direction, followed by a rapid recovery movement, always described in the direction of the recovery movement; it usually arises from labyrinthine or neurologic lesions or stimuli. labyrinthine n. SYN: vestibular n.. latent n. jerky n. that is brought out by covering one eye. The fast phase is always away from the covered eye. miner's n. n. occurring in 19th century coal miners and thought at the time to be related to lack of illumination as well as other factors. SYN: miner's disease (1) . minimal amplitude n. SYN: micronystagmus. ocular n. the pendular or, rarely, jerky n. seen in severely reduced vision. SYN: amaurotic n.. opticokinetic n. SYN: optokinetic n.. optokinetic n. n. induced by looking at moving visual stimuli. SYN: opticokinetic n., railroad n.. palatal n. a clonic spasm of the levator palati muscle, causing an audible click. SEE ALSO: palatal myoclonus. pendular n. a n. that, in most positions of gaze, has oscillations equal in speed and amplitude, usually arising from a visual disturbance. positional n. n. occurring only when the head is in a particular position. railroad n. SYN: optokinetic n.. rotational n. jerky n. arising from stimulation of the labyrinth by rotation of the head around any axis and induced by change of motion. rotatory n. a movement of the eyes around the visual axis. seesaw n. a n. in which one eye moves upward as the other moves downward, often combined with a torsional rotation (down and out, up and in—as in a see-saw). slow component of n. the fundamental movement of the eyes in the vestibuloocular reflex. upbeat n. a vertical jerky n. with a rapid component upward, occurring with brainstem lesions. vertical n. an up-and-down oscillation of the eyes. vestibular n. n. resulting from physiological stimuli to the labyrinth that may be rotatory, linear, caloric, compressive, or galvanic, or due to labyrinthal lesions. SEE ALSO: Bárány sign. SYN: labyrinthine n.. voluntary n. pendular n. in which the individual causes an extremely fine and rapid horizontal oscillation of the eyes. The nystagamus consists of back-to-back saccades and is seldom done for more than a few seconds at a time.
nystatin (ni-stat′in, nis′ta-tin)
An antibiotic substance isolated from cultures of Streptomyces noursei, effective in the treatment of all forms of candidiasis, particularly candidal infections of the intestine, skin, and mucous membranes. SYN: fungicidin. [New York State + -in]
Pierre H., French physician, 1771–1818. See N. law.
N-succinyladenylic acid (suk-sin-il-ad-e-nil′ik)
SYN: adenylosuccinic acid.
n-tetracosanoic acid (tet′ra-ko-sa-no′ik)
SYN: lignoceric acid.
An amino acid residue found in a number of proteins by the action of S-adenosyl-l-methionine on l-lysyl residues; upon release by proteolysis, Nε-trimethyllysine becomes the precursor of carnitine.
A pricking; paracentesis. [G.]
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