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(nī′ĭ-lizm, nē′ĭ-lizm) [L. nihil, nothing + -ism] 1. Disbelief in efficacy of medical therapy. SYN: therapeutic pessimism. 2. In psychiatry, a delusion in which everything is unreal or does not exist. SEE: Cotard delusion.

Nikolsky sign

(nĭ-kol′skē) [Pyotr Nikolsky, Russian dermatologist, 1855–1940] A condition seen in pemphigus, where the external layer of the skin can be detached from the basal layer and rubbed off by slight friction or injury.


National Institute of Mental Health.


National Institute of Neurological and Communicative Disorders and Stroke.


National Institute of Neurological Diseases and Blindness, a division of the National Institutes of Health of the U.S. Department of Health and Human Services.


National Institute of Neurological Disorders.

Nine-Hole Peg Test

ABBR: 9-HPT. A timed performance test in which a subject places nine dowels in nine holes and then removes them, first with the dominant hand and then with the nondominant one. The more rapidly the test is performed, the greater the dexterity of the subject.

ninhydrin test

(nĭn-hī′drĭn) A neurological test of sensation following peripheral nerve injury; used to detect a sympathetic response as indicated by sweat.


National Institute of Nursing Research.

ninth cranial nerve

Glossopharyngeal nerve.


(nī-ō′bē-um) [Niobe, a character in Gr. mythology + -ium] SYMB: Nb. A chemical element, atomic number 41, atomic weight (mass) 92.906.


National Institute of Occupational Safety and Health.


(nip′it) [Acronym from Nursing Initiative Promoting Immunization Training] A Web-based curriculum designed to educate nurses and nursing students about vaccine-preventable illnesses and contemporary immunization practices. Website:


(nip′ĕl) 1. The erectile protuberance at the tip of each breast from which the lactiferous ducts discharge. The nipple projects from the center of the more heavily pigmented areola. Both the nipple and the areola contain small sebaceous glands (Montgomery glands) that secrete a protective oily substance. SYN: mammae papilla; teat. SEE: breast for illus.

PATIENT CARE: Assessment: Instructions and demonstrations to help patients examine their own breasts should include inspecting the nipples and areolae for symmetry of shape, size, color, and texture and reporting any sign of retraction or evidence of discharge.

Pregnancy-related: Prenatal instructions about breast-feeding and postpartum breast care emphasize the signs to report promptly to the health care provider, e.g., nipple cracking, inversion, ...

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