Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «N»:
Needle stick: See: Needlestick injury....
Needlestick injury: A penetrating stab wound from a needle (or other sharp object) that may result in exposure to blood or other body fluids. The main concern is exposure to the blood or other body fluids of another person who may be carrying infectious disease. The pathogens of primary concern are ...
Nef gene: Short for negative factor gene, a gene the absence (or defect) of which diminishes the strength of a disease.
The term Nef gene was coined in 1989 in respect to HIV (the human immunodeficiency virus) and AIDS. The Nef gene in this situation is a gene in HIV the absence (or defect) of whi...
Negative calorie diet
Negative calorie diet: The
Negative calorie diet is a weight loss concept
based upon the premise that consumption of foods with a "negative caloric
effect" (meaning that the calories burned by chewing,
digesting, and eliminating the food are greater than those contained in the food
Negative clinical trial
Negative clinical trial: A clinical trial that shows that a new treatment is inferior to standard treatment. See: Clinical trials. See also:
Inconclusive clinical trial;
Non-inferior clinical trial;
Positive clinical trial....
Negative, false: A result that appears negative but fails to reveal a
situation. An example of a false negative: a particular test designed to detect cancer of
the toenail is negative but the person has toenail cancer....
Negative-strand RNA virus
Negative-strand RNA virus: Also known as an antisense-strand RNA virus, a virus whose genetic information consists of a single strand of RNA that is the negative or antisense strand which does not encode mRNA (messenger RNA). Examples of negative-strand RNA viruses include influenza virus, measles v...
Neglect, child: Child neglect is the most frequently reported form of child abuse (60% of all cases) and the most lethal.
Child neglect is the failure to provide for the shelter, safety, supervision and nutritional needs of the child. Child neglect may be physical, educational, or emotional negle...
NEI: Stands for National Eye
Institute, one of the US National Institutes of Health.
mission is to "conduct and support research, training,
health information dissemination, and other programs with
respect to blinding eye diseases, visual disorders,
mechanisms of visual function, preser...
Neisseria: Group of bacteria that includes the cause of
Neisseria infection: See: Meningococcal infection....
NEJM: The New England Journal of Medicine....
Nematodes: Roundworms. ...
Neo- (prefix): Prefix meaning new. From the
Greek "neos", new, young, fresh, recent.
Examples of terms starting with "neo-" include neonatal and
neonate (the newborn), neoplasia and neoplasm (new growth = tumor),
The opposite of neo- is paleo-. Although paleo- does enter
occasionally into ...
Neocortex: The newer portion of the cerebral cortex that serves as the center of higher mental functions for humans. The neocortex contains some 100 billion cells, each with 1,000 to 10,000 synapses (connections), and has roughly 100 million meters of wiring, all packed into a structure the size and...