Dictionary

pes Latin word meaning foot.

pes cavus A foot with an arch that is too high.

pes planus Flatfoot.

pest See plague.

pestilence 1 Originally, bubonic plague. See also plague. 2 Any epidemic disease that is highly contagious, infectious, virulent, and devastating.

pestis See plague.

PET scan Positron emission tomography scan, a highly specialized imaging technique that uses short-lived radioactive substances. This technique produces three-dimensional colored images. Unlike computerized tomography (CT) and magnetic resonance imaging (MRI), which look at anatomy or body form, PET studies metabolic activity or body function. PET scanning has been used primarily to evaluate problems of…

petechiae Tiny red spots in the skin or mucous membranes that do not blanch when pressed upon and that result from blood leaking from capillaries. The causes of petachiae include use of aspirin or other medications, allergic reactions, autoimmune disease, viral infection, thrombocythemia (an abnormally high platelet level), idiopathic thrombocytopenic purpura (ITP), leukemia and other…

petit mal See seizure, absence; seizure disorder.

Peutz-Jeghers syndrome A genetic condition that predisposes to an increased risk of developing cancer. The syndrome is characterized by frecklelike spots on the lips, mouth, and fingers and benign polyps in the intestines. Patients with Peutz-Jeghers syndrome are at increased risk for cancer of the esophagus, stomach, colon, rectum, breast, ovary, testis, and pancreas. The…

p53 A specific protein with a mass of 53 kilodaltons that is produced by a tumor-suppressor gene. Like other tumor-suppressor genes, the p53 gene normally controls cell growth. If p53 is physically lost or functionally inactivated, cells can grow without restraint. Many human tumors have mutations in the gene coding for the p53 protein.

PFS Patellofemoral syndrome.