Medical Dictionary

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noncariogenic (non-ka′re-o-jen′ik)
Not caries-producing.

noncellular (non-sel′u-lar)
1. Lacking cellular organization, as applied to viruses, which can only replicate within a cell, whether prokaryotic or eukaryotic. SYN: subcellular. 2. SYN: acellular (1) .

nonchromogens (non-kro′mo-jenz)
SYN: Runyon group III mycobacteria.

noncomedogenic (non-kom′e-do-jen′ik)
Tending not to promote the formation of comedones.

non compos mentis (non kom′pos men′tis)
Not of sound mind; mentally incapable of managing one's affairs. [L. non, not, + compos, participating, competent, + mens, gen. mentis, mind]

nondisease (non′dis-ez)
Absence of disease when a specific disease is suspected but not found.

nondisjunction (non-dis-junk′shun)
Failure of one or more pairs of chromosomes to separate at the meiotic stage of karyokinesis, with the result that both chromosomes are carried to the one daughter cell and none to the other. primary n. n. occurring in a previously normal cell. secondary n. n. occurring in an aneuploid cell that was the result of a primary n..

nonelectrolyte (non-e-lek′tro-lit)
A substance with molecules that do not, in solution, dissociate to ions and, therefore, do not carry an electric current.

nonestrogenic (non-es-tro-jen′ik)
1. Not causing estrus in animals. 2. Not having an action similar to that of an estrogen. Cf.:nonuterotropic. SYN: nonoestrogenic.

nonimmune (non-i-mun′)
Pertaining to an individual that is not immune or to a serum from such an individual.

nonimmunity (non-i-mun′i-te)
SYN: aphylaxis.

noninfectious (non′in-fek′shus)
Not infectious; not able to spread disease.

noninvasive (non-in-va′siv)
Denoting a procedure that does not require insertion of an instrument or device through the skin or a body orifice for diagnosis or treatment.

nonionic (non-i-on′ik)
A class of radiographic contrast media that do not ionize in solution, thereby decreasing effective osmolarity and toxicity. SEE ALSO: low osmolar contrast agent.

nonmaleficence (non-mal′ef-i-sens)
The ethical principle of doing no harm, based on the Hippocratic maxim, primum non nocere, first do no harm. [non- + L. maleficencia, evildoing, fr. male, badly, wrongly, + facio, to do, act]

nonmedullated (non-med′u-lat-ed)
SYN: unmyelinated.

nonmyelinated (non-mi′e-li-nat′ed)
SYN: unmyelinated.

nonneoplastic (non′ne-o-plas′tik)
Not neoplastic.

non-nucleated (non-noo′kle-a-ted)
Having no nucleus.

nonocclusion (non-o-kloo′shun)
Failure of a tooth to contact an opposing tooth.

nonoestrogenic
SYN: nonestrogenic.

nonose (non′os)
A sugar with nine carbon atoms. [L. nonus, ninth]

nonoxynol 9 (non′noks-i-nol)
A group of compounds that are surface-acting agents, used in spermicidal preparations such as contraceptive foam and diaphragm jelly.

nonparametric (non-par′a-met′rik)
A group of statistical maneuvers that can be applied effectively to data nonnormal or non-Gaussian in distribution.

nonparous (non-par′us)
SYN: nulliparous.

nonpenetrance (non-pen′e-trans)
The state in which a genetic trait, although present in the appropriate genotype ( i.e., homozygous, hemizygous, or heterozygous according to the state of dominance and mode of inheritance), fails to manifest itself in the phenotype because of modifying factors. Cf.:hypostasis.

nonproprietary name (non-pro-pri′e-tar-e)
A short name (often called a generic name) of a chemical, drug, or other substance that is not subject to trademark (proprietary) rights but is, in contrast to a trivial name, recognized or recommended by government agencies ( e.g., Federal Food and Drug Administration) and by quasi-official organizations ( e.g., U.S. Adopted Names Council) for general public use. Like a proprietary name, it is almost always a coined designation derived without using set criteria. Cf.:trivial name, proprietary name, semisystematic name, systematic name.

nonproteogenic (non-pro′te-o-jen′ik)
Not leading to the production of proteins.

nonreset nodus sinuatrialis (non-re′set no′dus si′noo-a-tre-a′lis)
Nonreset of the sinoatrial node produced by a premature atrial depolarizaton when the sum of the duration of the premature cycle and the return cycle is fully compensatory, i.e., twice the duration of the spontaneous cycle length. Cf.:reset nodus sinuatrialis.

nonrotation (non-ro-ta′shun)
Failure of normal rotation. n. of intestine a developmental anomaly resulting in the small intestine being on the right of the abdomen and the colon on the left. n. of kidney a developmental anomaly in which the hilum of the kidney retains its original position, with the renal pelvis lying ventrally.

nonsaponifiable (non-sa-pon-i-fi′a-bl)
Not subject to saponification; E.G., triacylglycerols are saponifiable but cholesterol is n..

nonsecretor (non-se-kre′tor, -tor)
An individual whose saliva does not contain antigens of the ABO blood group. SEE ALSO: secretor.

nonsense
As used in genetics, relating to a mutation that causes a sequence such that the growing peptide chain terminates, often after several incorrect amino acid residues are incorporated. n. suppression mutant tRNAs that read a chain termination codon as the signal for incorporation of a specific amino acid residue.

nonunion (non′un-yun)
Failure of normal healing of a fractured bone.

nonuterotropic (non-u-ter-o-tro′pik)
Not causing an effect on the uterus. Cf.:nonestrogenic.

nonvalent (non-va′lent)
Having no valency; not capable of entering into chemical composition.

nonvascular (non-vas′ku-lar)
SYN: avascular.

nonverbal (non-ver′bl)
Denoting communication without words, e.g., by signs, symbols, facial expressions, gestures, posture.

nonviable (non-vi′a-bl)
1. Incapable of independent existence; often denoting a prematurely born fetus. 2. Denoting a microorganism or parasite incapable of metabolic or reproductive activity.

Noonan
Jacqueline A., U.S. pediatric cardiologist, *1921. See N. syndrome.

nor-
1. Chemical prefix denoting 1) elimination of one methylene group from a chain, the highest permissible locant being used; 2) contraction of a (steroid) ring by one CH2 unit, the locant being the capital letter identifying the ring. Elimination of two methylene groups is denoted by the prefix dinor-; three groups, by trinor-, etc. 2. Chemical prefix denoting “normal,” i.e., unbranched chain of carbon atoms in aliphatic compounds, as opposed to branched with the same number of carbon atoms; e.g., norleucine vs. leucine.

noradrenaline (nor-a-dren′a-lin)
SYN: norepinephrine. n. acid tartrate SYN: norepinephrine bitartrate. n. bitartrate SYN: norepinephrine bitartrate.

nordazepam (nor′daz-pam)
An active sedative/hypnotic of the benzodiazepine class; an active metabolite of diazepam, chlorazepate, and several other benzodiazepines; has a long biologic half-life (40–80 hours).

nordefrin hydrochloride (nor-def′rin)
A sympathomimetic and vasoconstrictor.

norepinephrine (nor′ep-i-nef′rin)
l-(−)-α-(aminomethyl)-3,4-dihydroxybenzyl alcohol;a catecholamine hormone of which the natural form is d, although the l form has some activity; the base is considered to be the postganglionic adrenergic mediator, acting on α and β receptors; it is stored in chromaffin granules in the adrenal medulla, in much smaller amounts than epinephrine, and secreted in response to hypotension and physical stress; in contrast to epinephrine it has little effect on bronchial smooth muscle, metabolic processes, and cardiac output, but has strong vasoconstrictive effects and is used pharmacologically as a vasopressor, primarily as the bitartrate salt. SYN: levarterenol, noradrenaline. n. bitartrate (-)-α-(aminomethyl)-3,4-dihydroxybenzyl alcohol tartrate. For actions and uses, see n.. SYN: levarterenol bitartrate, noradrenaline acid tartrate, noradrenaline bitartrate.

norethandrolone (nor-eth-an′dro-lon)
An androgenic steroid similar chemically and pharmacologically to testosterone.

norethindrone (nor-eth′in-dron)
A potent orally effective progestational agent with some estrogenic and androgenic activity; used as a substitute for progesterone and, in combination with an estrogen, as an oral contraceptive. SYN: norethisterone. n. acetate an orally active progestin with some estrogenic and androgenic activity, used to treat endometriosis and, with an estrogen, as an oral contraceptive.

norethisterone (nor-eth-is′ter-on)
SYN: norethindrone.

norethynodrel (nor-e-thi′no-drel)
An orally active progestin with some estrogenic activity; used as a progestational agent and, in combination with mestranol, as an oral contraceptive.

norfloxacin (nor-floks′a-sin)
An oral broad-spectrum quinoline antibacterial agent used in the treatment of urinary tract infections.

norgestrel (nor-jes′trel)
A progestin used in oral contraceptive products.

norleucine (Nle) (nor-loo′sin)
α-Amino-n-caproic acid; 2-aminohexanoic acid;an α-amino acid, isomer of leucine and isoleucine, but not found in proteins; a deamination product of l-lysine, to which it is linked in collagens. SYN: glycoleucine.

norm
1. The usual value. 2. The desirable value or behavior.

norma, pl .normae (nor′ma, nor′me)
1. SYN: aspect. 2. SYN: profile (1) . 3. SYN: projection. [L. a carpenter's square] n. anterior SYN: facial aspect. n. basilaris SYN: external surface of cranial base. n. facialis [TA] SYN: facial aspect. n. frontalis facial aspect. n. inferior SYN: external surface of cranial base. n. lateralis [TA] SYN: lateral aspect. n. occipitalis [TA] SYN: occipital aspect. n. posterior SYN: occipital aspect. n. sagittalis the outline of a sagittal section through the skull. n. superior [TA] SYN: superior aspect. n. temporalis SYN: lateral aspect. n. ventralis SYN: external surface of cranial base. n. verticalis superior aspect.

normal (N) (nor′mal)
1. Typical; usual; according to the rule or standard. 2. In bacteriology, nonimmune; untreated; denoting an animal, or the serum or substance contained therein, that has not been experimentally or naturally immunized against a microorganism or its products. 3. Denoting a solution containing 1 eq of replaceable hydrogen or hydroxyl per liter; e.g., 1 mol/L HCl is 1 n, but 1 mol/L H2SO4 is 2 n. 4. In psychiatry and psychology, denoting a level of effective functioning that is satisfactory both to persons and to their social milieus. 5. Referring to a straight line (or plane) at a right angle to another line (or plane). 6. Not diseased or having been subjected to an experimental procedure. [L. normalis, according to pattern]

normalization (nor′mal-i-za′shun)
1. Making normal or according to the standard. 2. Reducing or strengthening of a solution to make it normal. 3. Adjusting one curve to another by multiplication of the points of the one by some arbitrary factor.

normalize (nor′mal-iz)
To effect normalization.

normative
Pertaining to the normal or usual.

normeperidine (nor-mep′er-i-din)
A metabolite of meperidine in which the N-methyl group has been removed. The compound possesses convulsant properties.

normetanephrine (nor-met′a-nef′rin)
A catabolite of norepinephrine found, together with metanephrine, in the urine and some tissues, resulting from the action of catechol-O-methyltransferase on norepinephrine; has no sympathomimetic actions.

normethadone (nor-meth′a-don)
An antitussive with narcotic properties.

normo-
Normal, usual. [L. normalis, according to pattern]

normobaric (nor-mo-bar′ik)
Denoting a barometric pressure equivalent to sea level pressure. [normo- + G. baros, weight]

normoblast (nor′mo-blast)
A nucleated red blood cell, the immediate precursor of a normal erythrocyte in humans. Its four stages of development are: 1) pronormoblast, 2) basophilic n., 3) polychromatic n., and 4) orthochromatic n. See erythroblast. [normo- + G. blastos, sprout, germ]

normoblastosis
Excessive production of normoblasts by the bone marrow.

normocapnia (nor-mo-kap′ne-a)
A state in which the arterial carbon dioxide pressure is normal, about 40 mm Hg. SEE ALSO: eucapnia. [normo- + G. kapnos, vapor]

normocephalic (nor′mo-se-fal′ik)
SYN: mesocephalic. [normo- + G. kephale, head]

normochromia (nor-mo-kro′me-a)
Normal color; referring to blood in which the amount of hemoglobin in the red blood cells is normal. [normo- + G. chroma, color]

normochromic (nor-mo-kro′mik)
Being normal in color; referring especially to red blood cells that possess the normal quantity of hemoglobin.

normocyte (nor′mo-sit)
A nonnucleated erythrocyte of normal size (average 7.5 μm); a normal, healthy red blood cell. SYN: normoerythrocyte. [normo- + G. kytos, cell]

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