Dictionary

pro- A prefix (from both Greek and Latin) with many meanings, including before, in front of, preceding, on behalf of, in place of, and the same as.

pro time Prothrombin time.

probability The likelihood that something will happen. For example, a probability of less than .05 indicates that the likelihood of something occurring by chance alone is less than 5 in 100, or 5 percent. This level of probability is usually taken as the level of biologic significance, so a higher incidence may be considered meaningful….

proband The family member through whom a family’s medical history comes to attention. For example, a proband might be a baby with Down syndrome. The proband may also be called the index case, propositus (if male), or proposita (if female).

probe 1 In surgery, a slender, flexible rod with a blunt end that is used to explore. 2 In molecular genetics, a labeled bit of DNA or RNA that is used to find its complementary sequence or to locate a particular clone.

probiotic A substance that appears to replenish or support the growth of helpful bacteria in the intestinal tract. The most common probiotic is acidophilus, which is present in yogurt, in acidophilus milk, and in supplements. As the name indicates, probiotics have been developed to counter one unfortunate effect of treatment with antibiotics: the decimation of…

process In anatomy, a projection from a structure. For example, the process of the mandible is the part of the lower jaw that projects forward.

proclivity An inclination or a predisposition toward something, especially a strong inherent inclination toward something objectionable. For example, a patient might be said to have a proclivity toward alcohol.

proctitis Inflammation of the rectum. Proctitis may be due to a considerable number of causes, including infectious agents and ulcerative colitis. Infectious proctitis is often due to agents such as Chlamydia trachomatis, Neisseria gonorrheae, and herpes simplex virus, all of which can be acquired during anoreceptive intercourse. Proctitis is also a hallmark of ulcerative colitis,…

proctitis, ulcerative Ulcerative colitis that is limited to the rectum. See also colitis, ulcerative; proctitis.

proctology A medical specialty that deals with disorders of the rectum and anus.

proctosigmoidoscopy An examination of the rectum and the lower part of the colon, using a thin, lighted instrument called a sigmoidoscope.