Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «E»:
Evidence based medicine
Evidence based medicine: See: Evidence-based medicine....
Evolution: The continuing process of change, especially in reference to natural selection.
Charles Darwin (1809-82) noted that successful species produce more offspring in each generation than are needed to replace the adults who die. Not all offspring survive. Some creatures or plants struggle to s...
Evolution, biologic: Biologic evolution was
contrasted with cultural (social) evolution in 1968 by A.G. Motulsky
who pointed out that biologic evolution is mediated by genes, shows a
slow rate of change, employs random variation (mutations) and
selection as agents of change, new variants are of...
Evolutionarily conserved gene
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Evolutionarily conserved sequence
Evolutionarily conserved sequence: A base sequence in a DNA
molecule (or an amino acid sequence in a protein) that has remained
largely unchanged throughout evolution....
Ewing sarcoma: A type of bone tumor that occurs in children and adolescents, most often in the large bones of the arms and legs and the flat bones of the pelvis, spine and ribs. The tumor is caused by a chromosome abnormality, called a translocation (an exchange of material), most commonly between c...
Exacerbate: To make worse. For example, smoking may exacerbate systemic lupus erythematosus....
Exacerbation: A worsening. In medicine, exacerbation may refer to an increase in the severity of a disease or its signs and symptoms. For example, exacerbation of asthma is one of the serious effects of air pollution.....
Exaggerated startle disease
Exaggerated startle disease: A genetic disorder also known as hyperexplexia in which babies have an exaggerated startle reflex (reaction).
This disorder was not recognized until 1962 when it was described by Drs. Kok and Bruyn as a disease with the onset at birth of hypertonia (stiffness), exaggerat...
Examination, digital rectal (DRE)
Examination, digital rectal (DRE): An exam done to detect abnormalities that can be felt (palpated) from within the rectum. The doctor inserts a lubricated, gloved finger into the rectum and feels for anything that is not normal.
The digital rectal exam is an important screening test for the detec...
Examination, postmortem: An autopsy. Also called a necropsy.
Postmortem examinations have been done for more than 2,000 years but during most of this time they were rarely done, and then only for legal purposes. The Roman physician Antistius performed one of the earliest autopsies on record. In 44 ...
Exanthem: A rash. The word
"exanthem" comes from the Greek "exanthema" which means "a
breaking out." "Anthos" in Greek is "a flower,"
particularly a flower blossom, so a child breaking out with
an rash is likened to a flower bursting into bloom.
Exanthem subitum: Means a sudden rash. A
viral disease of infants and young children with sudden onset of high fever which lasts
several days and then suddenly subsides leaving in its wake a fine red rash. The causative
agent is herpesvirus type 6 so the disease is known as Sixth Disease. Also calle...
Excess iron: Iron overload can damage the heart, liver, gonads and other organs.
Iron overload is a particular risk for:
People with certain genetic conditions such as hemochromatosis; and
People receiving repeated blood transfusions.
According to the National Academy of Sciences, the
Excess selenium: Too much selenium
(selenosis) which may
cause reversible balding and brittle nails, give a garlic odor to the breath, and cause intestinal distress, weakness and slowed mental functioning. People who chronically consume more than the tolerable upper intake level (UL) of selenium -...