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a result produced by an action.
additive effect the combined effect produced by the action of two or more agents, being equal to the sum of their separate effects.
adverse effect a symptom produced by a drug or therapy that is injurious to the patient.
Bainbridge effect Bainbridge reflex.
Bohr effect decreased affinity of hemoglobin for oxygen caused by an increase of carbon dioxide; the oxyhemoglobin dissociation curve is displaced to the right because of higher partial pressure of carbon dioxide and lower pH. See also Haldane effect.
Crabtree effect the inhibition of oxygen consumption on the addition of glucose to tissues or microorganisms having a high rate of aerobic glycolysis; the converse of the Pasteur effect.
cumulative effect the action of a drug or treatment resulting from repeated use.
Doppler effect see doppler effect.
experimenter e's demand characteristics.
extrapyramidal e's the side effects caused by neuroleptic medications, including dystonias, parkinsonism, akathisia, and tardive dyskinesia.
Haldane effect increased oxygenation of hemoglobin promotes dissociation of carbon dioxide; see also Bohr effect.
Hawthorne effect a psychological response in which the subjects in a research study change their behavior simply because they are subjects in a study, not because of the research treatment.
heel effect variation in x-ray beam intensity and projected focal spot size along the long axis of the x-ray tube from cathode to anode.
parallax effect the position of the image on each emulsion of dual emulsion film; it is accentuated by tube-angled x-ray techniques.
Pasteur effect the decrease in the rate of glycolysis and the suppression of lactate accumulation by tissues or microorganisms in the presence of oxygen.
photoelectric effect ejection of electrons from matter as a result of interaction with photons from high frequency electromagnetic radiation, such as x-rays; the ejected electrons may be energetic enough to ionize multiple additional atoms.
placebo effect the total of all nonspecific effects, both good and adverse, of treatment; it refers primarily to psychological and psychophysiological effects associated with the caregiver-patient relationship and the patient's expectations and apprehensions concerning the treatment. See also placebo.
position effect in genetics, the changed effect produced by alteration of the relative positions of various genes on the chromosomes.
pressure effect the sum of the changes that are due to obstruction of tissue drainage by pressure.
proarrhythmic effect any new, more advanced form of arrhythmia caused by an antiarrhythmic agent, especially those that produce hemodynamically important symptoms. These arrhythmias occur less than 30 days after initiation of treatment and are not due to a new event such as acute myocardial infarction or hypokalemia.
side effect a consequence other than that for which an agent is used, especially an adverse effect on another organ system.
Somogyi effect see somogyi effect.
a change in the phenotypic expression of one or more genes due to a change in its physical location with respect to other genes; may result from change in chromosome structure or from crossing-over.
Variation in the expression of a gene resulting from changes in its location within a chromosome or genome.
po·si·tion ef·fect(pŏ-zish'ŏn e-fekt')
A change in the phenotypic expression of one or more genes due to a change in physical location with respect to other genes; may result from change in chromosome structure or from crossing over.
position effectThe effect on the expression of a gene resulting from its translocation to a different part of the genome. A gene may, for instance, be inactivated if moved to a region that is permanently in a highly condensed condition (heterochromation).
position effectan alteration to the expression of a gene due to a change in its location within the GENOME.
a result produced by an action. The relationship between the two can be expressed in linear form. The total association between them may be the sum of a number of effects. The effect may be direct when it is exerted without being transmitted through intervening factors, or indirect when it is. It may also be a spurious effect when the observed changes are due to causes and correlations common to both.
the combined effect produced by the action of two or more agents, being equal to the sum of their separate effects.
the stimulation of sexual behavior in a male animal upon exposure to a new female.
demand characteristics; the characteristics supplied by the experimental subject in response to what it perceives are the demands of the experimenter.
a factor which modifies the effect of a causal factor under study. Called also interaction.
in genetics, the changed effect produced by alteration of the relative positions of various genes on the chromosomes.
the sum of the changes that are due to obstruction of tissue drainage by pressure.
a consequence other than that for which an agent is used, especially an adverse effect on another organ system.