Dictionary

encephalopathy, mitochondrial See MELAS syndrome.

electrolysis Permanent removal of body hair, including the hair root, with an electronic device. Although electrolysis is promoted as a permanent process, many people find that hair does grow back (albeit slowly) after electrolysis. Electrolysis may be done by a dermatologist, by an electrolysis technician, or by a facial technologist or esthetician.

electrolyte A substance that dissociates into ions in solution and acquires the capacity to conduct electricity. Sodium, potassium, chloride, calcium, and phosphate are examples of electrolytes, informally known as lytes. Electrolyte replacement is needed when a patient has prolonged vomiting or diarrhea, and as a response to strenuous athletic activity. Commercial electrolyte solutions are available,…

electromyogram A test that records the electrical activity of muscles. Normal muscles produce a typical pattern of electrical current that is usually proportional to the level of muscle activity. Diseases of muscle and/or nerves can produce abnormal electromyogram patterns. Abbreviated EMG. Also known as a myogram.

electron microscope A microscope in which an electron beam replaces light to form the image. An electron microscope permits greater magnification and resolution than an optical microscope, but the electron densities of objects are shown rather than their actual images. Abbreviated EM.

electron microscopy See electron microscope.

electrophoresis A method used in clinical and research laboratories for separating molecules according to their size and electrical charge. An electric current is passed through a medium that contains the mixture of molecules. Each kind of molecule travels through the medium at a different rate, depending on its electrical charge and molecular size. Separation of…

electroretinography A test in which the electrical potentials generated by the retina of the eye are measured when the retina is stimulated by light. Abbreviated ERG. In an ERG, an electrode is placed on the cornea at the front of the eye that measures the electrical response of the rods and cones, the visual cells…

electroshock therapy See electroconvulsive therapy.

elephant nails See pachyonychia congenita.

ELISA Enzyme-linked immunosorbent assay, a rapid immunochemical test that involves an enzyme used for measuring a wide variety of tests of body fluids. ELISA tests detect substances that have antigenic properties, primarily proteins rather than small molecules and ions, such as glucose and potassium. Some of these substances include hormones, bacterial antigens, and antibodies. ELISA…

elliptocytosis A blood disorder characterized by elliptically shaped red blood cells with variable breakup of red cells (hemolysis) and varying degrees of anemia. Inherited as a dominant trait, elliptocytosis is due to the mutation of one of the genes that encodes proteins of the red cell membrane skeleton. There are several forms of elliptocytosis caused…