Dictionary

rejection In transplantation biology, when the body’s immune system attacks transplanted cells, tissues, or organs. For example, a transplanted kidney may be rejected.

Reiter syndrome See reactive arthritis.

rehydrate To restore lost water to the body tissues and fluids. Prompt rehydration is imperative whenever dehydration occurs, whether from diarrhea, exposure, lack of drinking water, or medication use. Rehydration can occur orally or via IV administration of fluids.

rehabilitation The process of helping a person who has suffered an illness or injury restore lost skills and so regain maximum self-sufficiency. For example, rehabilitation work after a stroke may help the patient walk and speak clearly again.

rehab An abbreviation for rehabilitation.

regurgitation A backward flowing. For example, vomiting is a regurgitation of food from the stomach, and the sloshing of blood back into the heart when a heart valve is incompetent is a regurgitation of blood.

regulatory gene A gene that regulates the expression of other genes.

regress To return or go back, particularly to return to a pattern of behavior or level of skill characteristic of a younger age. For example, if a 3-yearold child begins to regress by losing the ability to control his bowels or speak, that is a cause for medical concern.

registry A collection of information. A registry is usually organized so that the data in it can be analyzed. For example, analysis of data in a tumor registry maintained at a hospital may show a rise in lung cancer among women.

regional lymphadenitis See cat scratch fever.

regional enteritis See Crohn’s disease.

regimen A plan or a regulated course, such as a diet, exercise, or treatment, that is designed to give a good result. A low-salt diet is one type of dietary regimen.