| naive T-cell | A T-cell arising from the immune system's production of fresh cells in the bone marrow. Naive T-cells respond to newly encountered pathogens containing antigens the immune system has not processed before. The naive T-cells' activation and proliferation create an acquired immune response to the newly encountered pathogenic agent. After the disease is eradicated, a portion of the T-cell population engendered by the activated naive T-cells constitutes a reservoir of memory cells, which proliferate and respond very quickly to any recurrence of the disease. See: both Memory T-Cell and Immune System. (09 Oct 1997) |
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| Najjar, Victor | <person> U.S. Physician and biochemist, *1914. See: Crigler-Najjar syndrome. (05 Mar 2000) |
| Nakanishi | K., Japanese physician. See: Nakanishi's stain. (05 Mar 2000) |
| Nakanishi's stain | <technique> A method for vital staining of bacteria in which a slide is treated with hot methylene blue solution until it acquires a sky-blue colour, after which a drop of an emulsion of the bacteria is put on the cover glass and the latter laid on the slide; the bacteria are stained differentially, some parts more intensely than others. (05 Mar 2000) |
| naked | 1. Having no clothes on; uncovered; nude; bare; as, a naked body; a naked limb; a naked sword. 2. Having no means of defense or protection; open; unarmed; defenseless. "Thy power is full naked." (Chaucer) "Behold my bosom naked to your swords." (Addison) 3. Unprovided with needful or desirable accessories, means of sustenance, etc.; destitute; unaided; bare. "Patriots who had exposed themselves for the public, and whom they say now left naked." (Milton) 4. Without addition, exaggeration, or excuses; not concealed or disguised; open to view; manifest; plain. "The truth appears so naked on my side, That any purblind eye may find it out." (Shak) "All things are naked and opened unto the eyes of him with whom we to do." (Heb. Iv. 13) 5. Mere; simple; plain. "The very naked name of love." (Shak) 6. <botany> Without pubescence; as, a naked leaf or stem; bare, or not covered by the customary parts, as a flower without a perianth, a stem without leaves, seeds without a pericarp, buds without bud scales. 7. Not having the full complement of tones; said of a chord of only two tones, which requires a third tone to be sounded with them to make the combination pleasing to the ear; as, a naked fourth or fifth. Naked bed, a bed the occupant of which is naked, no night linen being worn in ancient times. Naked eye, the eye alone, unaided by glasses, or by telescope, microscope, or the like. Naked-eyed medusa. <medicine> A nudibranch. <botany> Naked wood, a large rhamnaceous tree (Colibrina reclinata) of Southern Florida and the West Indies, having a hard and heavy heartwood, which takes a fine polish. Synonym: Nude, bare, denuded, uncovered, unclothed, exposed, unarmed, plain, defenseless. Origin: AS. Nacod; akin to D. Naakt, G. Nackt, OHG. Nacchot, nahhot, Icel. Nokvir, nakinn, Sw. Naken, Dan. Nogen, Goth. Naqas, Lith. Ngas, Russ. Nagii, L. Nudus, Skr. Nagna. Cf. Nude. Source: Websters Dictionary (01 Mar 1998) |
| naked virus | A virus consisting only of a nucleocapsid; i.e., one that does not possess an enclosing envelope. (05 Mar 2000) |
| nakedness | 1. The condition of being naked. 2. The privy parts; the genitals. "Ham .. Saw the nakedness of his father." (Gen. Ix. 22) Source: Websters Dictionary (01 Mar 1998) |
| naker | <zoology> Same as Nacre. Source: Websters Dictionary (01 Mar 1998) |
| nakoo | <zoology> The gavial. Alternative forms: nako. Origin: From the native name. Source: Websters Dictionary (01 Mar 1998) |
| nalbuphine | <chemical> A narcotic used as a pain medication. It appears to be an agonist at kappa opioid receptors and an antagonist or partial agonist at mu opioid receptors. Pharmacological action: analgesics, opioid, narcotic antagonists, narcotics. Chemical name: Morphinan-3,6,14-triol, 17-(cyclobutylmethyl)-4,5-epoxy-, (5alpha,6alpha)- (12 Dec 1998) |
| nalbuphine hydrochloride | 17-(Cyclobutylmethyl)4,5a-epoxymorphinan-3,6a,14-triol hydrochloride;a synthetic opioid analgesic chemically related to oxymorphone, a narcotic, and to naloxone, a narcotic antagonist, with both agonist and antagonist narcotic properties. (05 Mar 2000) |
| naled | <chemical> An organophosphate cholinesterase inhibitor that is used as an insecticide and as an acaricide. Pharmacological action: cholinesterase inhibitor, insecticide, organophosphate. Chemical name: Phosphoric acid, 1,2-dibromo-2,2-dichloroethyl dimethyl ester (12 Dec 1998) |
| nalidixic acid | <drug> Synthetic antibiotic that interferes with DNA gyrase and inhibits prokaryotic replication. Often used in selective media. (18 Nov 1997) |
| nalorphine | <chemical> (5 alpha,6 alpha)-7,8-didehydro-4,5-epoxy-17-(2-propenyl)morphinan-3,6-diol. A narcotic antagonist with some agonist properties. It is an antagonist at mu opioid receptors and an agonist at kappa opioid receptors. Given alone it produces a broad spectrum of unpleasant effects and it is considered to be clinically obsolete. Pharmacological action: narcotic antagonists. Chemical name: Morphinan-3,6-diol, 7,8-didehydro-4,5-epoxy-17-(2-propenyl)-, (5alpha,6alpha)- (12 Dec 1998) |
| naloxone | <drug> An alkaloid antagonist of morphine and of the opiate peptides. (18 Nov 1997) |