Category: N

  • Nontropical sprue

    Malabsorption/diarrhea due to localized reaction to certain foods. This ailment affects individuals who have never resided in tropical regions, and although it shares many similarities with sprue, it is actually the adult form of celiac disease. The underlying issue involves the disruption of small intestine function, linked to an intolerance to gluten, which hinders the…

  • Noninvasive technique

    A medical treatment or procedure that does not involve surgery. X-rays, for example, are in this category of techniques.  

  • Noninsulin-dependent diabetes mellitus

    Outdated term for type 2 Diabetes Mellitus.  

  • Nonimmunological defense mechanism

    One of the defense mechanisms is the digestive tract, which forms a physical barrier against unwanted effects of food. The mucus membrane of the gut forms a protective barrier against penetration of pathogenic microorganisms and allergens. Also, the secretion of certain enzymes and gastric acid (which may lead to degradation of unwanted substances) and the…

  • Nonheme iron

    Iron in the body not associated with the heme of hemoglobin. Some of the cytochromes have iron as part of their structures.  

  • Nonexperimental studies

    Studies in which the exposure is “chosen” by the subjects themselves. The investigator confines himself or herself to observe the subjects and to collect data on their exposure and disease, without interfering with their way of life. Also known as observational studies.  

  • Noncaloric sweeteners

    Non-nutritive sweeteners, cyclamate, saccharine, and aspartame, compounds that elicit the sweet taste without contributing to the energy intake.  

  • Nitroprusside sodium

    A vasodilator that is used as an antihypertensive agent.  

  • Nisoldipine

    A calcium channel blocker that is used as an antihypertensive drug.  

  • Nick translation

    A technique for labeling DNA based on the ability of the DNA polymerase from E. coli to degrade a strand of DNA that has been nicked and then resynthesized; if a radioactive nucleotide is used, the rebuilt strand becomes labeled and can be used as a probe.