median effective dose
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the quantity to be administered at one time, as a specified amount of medication or a given quantity of radiation.
absorbed dose that amount of energy from ionizing radiations absorbed per unit mass of matter, expressed in rads.
air dose the intensity of an x-ray or gamma-ray beam in air, expressed in roentgens.
booster dose an amount of immunogen (vaccine, toxoid, or other antigen preparation), usually smaller than the original amount, injected at an appropriate interval after primary immunization to sustain the immune response to that immunogen.
curative dose (CD) a dose that is sufficient to restore normal health. See also median curative dose.
divided dose fractionated dose.
effective dose (ED) that quantity of a drug that will produce the effects for which it is administered. See also median effective dose.
erythema dose that amount of radiation that, when applied to the skin, causes erythema (temporary reddening).
fatal dose lethal dose.
fractionated dose a fraction of the total dose prescribed, as of chemotherapy or radiation therapy, to be given at intervals, usually during a 24-hour period.
infective dose (ID) that amount of a pathogenic agent that will cause infection in susceptible subjects. See also median infective dose and tissue culture infective dose.
lethal dose (LD) that quantity of an agent that will or may be sufficient to cause death. See also median lethal dose and minimum lethal dose.
loading dose a dose of medication, often larger than subsequent doses, administered for the purpose of establishing a therapeutic level of the medication.
maintenance dose the amount of a medication administered to maintain a desired level of the medication in the blood.
maximum tolerated dose tolerance dose.
maximum permissible dose the largest amount of ionizing radiation that one may safely receive within a specified period according to recommended limits in current radiation protection guides. The specific amounts vary with age and circumstance.
median curative dose (CD50) a dose that abolishes symptoms in 50 per cent of test subjects.
median effective dose (ED50) a dose that produces the desired effect in 50 per cent of a population.
median infective dose (ID50) that amount of pathogenic microorganisms that will produce demonstrable infection in 50 per cent of the test subjects.
median lethal dose (LD50) the quantity of an agent that will kill 50 per cent of the test subjects; in radiology, the amount of radiation that will kill, within a specified period, 50 per cent of individuals in a large group or population.
median tissue culture infective dose (TCID50) that amount of a pathogenic agent that will produce infection in 50 per cent of cell cultures inoculated.
minimum lethal dose
1. the amount of toxin that will just kill an experimental animal.
2. the smallest quantity of diphtheria toxin that will kill a guinea pig of 250-gm weight in 4 to 5 days when injected subcutaneously.
reference dose an estimate of the daily exposure to a substance for humans that is assumed to be without appreciable risk; it is calculated using the no observed adverse effect level and is more conservative than the older margin of safety.
skin dose (SD)
1. the air dose of radiation at the skin surface, comprising the primary radiation plus backscatter.
2. the absorbed dose in the skin.
threshold dose the minimum dose of ionizing radiation, a chemical, or a drug that will produce a detectable degree of any given effect.
threshold erythema dose (TED) the single skin dose that will produce, in 80 per cent of those tested, a faint but definite erythema within 30 days, and in the other 20 per cent, no visible reaction.
tissue culture infective dose (TCID) that amount of a pathogenic agent that will produce infection when inoculated on tissue cultures; used with a numeric qualifier.
tolerance dose the largest quantity of an agent that may be administered without harm. Called also maximum tolerated dose.
ef·fec·tive dose (ED),
1. the dose that produces a specific effect; when followed by a subscript (generally "ED50"), it denotes the dose having such an effect on a certain percentage (for example, 50%) of the test animals; ED50 is the median effective dose;
2. in radiation protection, the sum of the equivalent doses in all tissues and organs of the body weighted for tissue effects of radiation. The SI unit of effective dose is the sievert (Sv) (=100 rem).
3. in diagnostic radiology, if a patient weighing W absorbs A joules of energy, and the experimentally derived ratio of effective dose to energy absorbed in an anthropomorphic phantom with mass M is R, then the effective dose is A·R·M:W. This formula results in a larger value for children despite their lesser absorption of radiation.
median effective dose (ED50)
the dose of a drug that may be expected to cause a specific intensity of effect in half of the patients to whom it is given.
ef·fec·tive dose(ED) (e-fek'tiv dōs)
1. The dose that produces the desired effect; when followed by a subscript (generally "ED50"), it denotes the dose having such an effect on a certain percentage (e.g., 50%) of the test animals; ED50 is the median effective dose.
2. In radiation protection, the sum of the equivalent doses in all tissues and organs of the body weighted for tissue effects of different types of radiation. The unit of effective dose is the sievert (Sv) or rem.
ef·fec·tive dose(ED) (e-fek'tiv dōs)
Dose that produces a specific result; when followed by a subscript (generally "ED50"), it denotes the dose having such an effect on a given percentage (e.g., 50%) of the test animals; ED50 is the median effective dose.