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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.
the promotion of carbon dioxide dissociation in blood by an increase in the oxygenation of hemoglobin.
Hal·dane ef·fect(hawl'dān e-fekt')
The promotion of carbon dioxide dissociation by oxygenation of hemoglobin.
Haldane,John S., Scottish physiologist at Oxford, 1860-1936.
Haldane apparatus - a device used for analyzing respiratory gases.
Haldane chamber - an obsolete chamber for metabolic studies on animals.
Haldane effect - the promotion of carbon dioxide dissociation by oxygenation of hemoglobin.
Haldane relationship - a mathematical relationship between the equilibrium constant of an enzyme-catalyzed reaction and all of that enzyme's kinetic parameters.
Haldane transformation - multiplication of inspired oxygen concentration by the ratio of expired to inspired nitrogen concentration in the calculation of oxygen consumption or respiratory quotient by the open circuit method.
Haldane tube - a tube for securing human alveolar air samples.
Haldane-Priestley sample - an approximation of alveolar gas obtained from the end of a sudden maximal expiration into a Haldane tube.
oxygen loss from hemoglobin makes the hemoglobin more basic and enhances the absorption of CO2.