Medical Dictionary

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praziquantel (pra-zi-kwahn′tel)
A pyrazinoisoquinoline derivative; a synthetic heterocyclic broad-spectrum anthelmintic agent effective against all schistosome species parasitic of humans as well as most other trematodes and adult cestodes.

prazosin hydrochloride (pra′zo-sin)
An antihypertensive agent, which is an α1-specific adrenergic blocking drug.

pre-
Anterior; before (in time or space). SEE ALSO: ante-, pro- (1) . [L. prae]

preagonal (pre-ag′o-nal)
Immediately preceding death. [pre- + G. agon, struggle (agony)]

prealbumin (pre-al-bu′min)
1. A protein component of plasma having a molecular weight of about 55,000 and containing 1.3% carbohydrate; estimated plasma concentration is 0.3 g per 100 mL; abnormal levels of p. are found in cases of familial amyloidosis. SYN: transthyretin. 2. The protein-containing zone observed in zone electrophoresis of serum that migrates more rapidly than serum albumin. thyroxine-binding p. (TBPA) a protein located in the “p.” zone upon electrophoretic analysis of plasma proteins; its affinity for binding thyroxine is less than that of thyroxine-binding globulin but greater than that of albumin. SYN: thyroxine-binding protein (2) .

preanal (pre-a′nal)
Anterior to the anus.

preanesthetic (pre-an-es-thet′ik)
Before anesthesia.

preantiseptic (pre′an-ti-sep′tik)
Denoting the period, especially in relation to surgery, before the adoption of the principles of antisepsis.

preaortic (pre′a-or′tik)
Anterior to the aorta; denoting certain lymph nodes so situated.

preaseptic (pre-a-sep′tik)
Denoting the period, especially the early antiseptic period in relation to surgery, before the principles of asepsis were known or adopted.

preauricular (pre-aw-rik′u-lar)
Anterior to the auricle of the ear; denoting lymphatic nodes so situated.

preaxial (pre-ak′se-al)
1. Anterior to the axis of the body or a limb, the latter being in the anatomical position. 2. Denoting the portion of a limb bud that lies cranial to the axis of the limb: the radial aspect of the upper limb and the tibial aspect of the lower limb.

precalciferol (pre-kal-si′fer-ol)
The immediate precursor of ergocalciferol and lumisterol.

precancer (pre-kan′ser)
A lesion from which a malignant neoplasm is believed to develop in a significant number of instances, and which may or may not be recognizable clinically or by microscopic changes in the affected tissue.

precancerous (pre-kan′ser-us)
Pertaining to any lesion that is interpreted as precancer. SYN: premalignant.

precapillary (pre-kap′i-lar-e)
Preceding a capillary;an arteriole or venule.

precardiac (pre-kar′de-ak)
Anterior to the heart.

precardinal (pre-kar′di-nal)
Relating to the anterior cardinal veins.

precartilage (pre-kar′ti-lij)
A closely packed aggregation of mesenchymal cells just prior to their differentiation into embryonic cartilage.

precautions

precava (pre-ka′va)
SYN: superior vena cava.

precentral (pre-sen′tral)
Referring to the cerebral convolution immediately anterior to the central sulcus: p. gyrus.

prechordal (pre-kor′dal)
SYN: prochordal.

prechroming (pre-krom′ing)
Treatment of a tissue or fabric first with a metal mordant, followed by a dye.

precipitable (pre-sip′i-ta-bl)
Capable of being precipitated.

precipitant (pre-sip′i-tant)
Anything causing a precipitation from a solution.

precipitate (pre-sip′i-tat)
1. To cause a substance in solution to separate as a solid. 2. A solid separated out from a solution or suspension; a floc or clump, such as that resulting from the mixture of a specific antigen and its antibody. 3. Accumulation of inflammatory cells on the corneal endothelium in uveitis (keratic precipitates). [L. praecipito, pp. -atus, to cast headlong] keratic precipitates inflammatory cells on the corneal endothelium. SYN: punctate keratitis, keratitis punctata. mutton-fat keratic precipitates coalescent precipitates forming small plaques that gradually become more translucent. pigmented keratic precipitates precipitates that occur in eyes with brown irides or after prolonged inflammation. red p. SYN: mercuric oxide, red. sweet p. SYN: calomel. white mercuric p. SYN: ammoniated mercury. yellow p. SYN: mercuric oxide, yellow.

precipitation (pre-sip-i-ta′shun)
1. The process of formation of a solid previously held in solution or suspension in a liquid. 2. The phenomenon of clumping of proteins in serum produced by the addition of a specific precipitin. [see precipitate] double antibody p. a method of separating antibody-bound antigen ( e.g., insulin) from free antigen by precipitating the former with antibody specific for immunoglobulin. SYN: double antibody immunoassay, double antibody method. immune p. SYN: immunoprecipitation.

precipitin (pre-sip′i-tin)
An antibody that under suitable conditions combines with and causes its specific and soluble antigen to precipitate from solution. SYN: precipitating antibody.

precipitinogen (pre-sip-i-tin′o-jen)
1. An antigen that stimulates the formation of specific precipitin when injected into an animal body. 2. A precipitable soluble antigen. SYN: precipitogen. [precipitin + G. -gen, producing]

precipitinogenoid (pre-sip-i-tin′o-je-noyd)
A precipitinogen that is altered by means of heating, thereby resulting in a substance that combines with the specific precipitin, but does not lead to the formation of a precipitate.

precipitogen (pre-sip′i-to-jen)
SYN: precipitinogen.

precipitoid (pre-sip′i-toyd)
A heat-treated precipitin that when mixed with specific precipitinogen does not cause a precipitate and also interferes with the precipitating effect of additional nonheated precipitin. [precipitin + G. eidos, resemblance]

precipitophore (pre-sip′i-to-for)
In Ehrlich side chain theory, the portion of a precipitin molecule that is required in the formation of a precipitate, as distinguished from the haptophore group. [precipitin + G. phoros, bearing]

precision (pre-si′zhun)
1. The quality of being sharply defined or stated; one measure of p. is the number of distinguishable alternatives to a measurement. 2. In statistics, the inverse of the variance of a measurement or estimate. 3. Reproducibility of a quantifiable result; an indication of the random error.

preclinical (pre-klin′i-kal)
1. Before the onset of disease. 2. A period in medical education before the student becomes involved with patients and clinical work.

precocious (pre-ko′shus)
Developing unusually early or rapidly. [L. praecox, premature]

precocity (pre-kos′i-te)
Unusually early or rapid development of mental or physical traits. [see precocious]

precognition (pre-kog-nish′un)
Advance knowledge, by means other than the normal senses, of a future event; a form of extrasensory perception. [L. praecogito, to ponder before]

preconscious (pre-kon′shus)
In psychoanalysis, one of the three divisions of the psyche according to Freud's topographic psychology, the other two being the conscious and unconscious; includes all ideas, thoughts, past experiences, and other memory impressions that with effort can be consciously recalled. Cf.:foreconscious.

preconvulsive (pre-kon-vul′siv)
Denoting the stage in an epileptic paroxysm preceding convulsions ( e.g., aura).

precordia (pre-kor′de-a)
The epigastrium and anterior surface of the lower part of the thorax. SYN: antecardium. [L. praecordia (ntr. pl. only), the diaphragm, the entrails, fr. prae, before, + cor (cord-), heart]

precordial (pre-kor′de-al)
Relating to the precordia.

precordialgia (pre′kor-de-al′je-a)
Pain in the precordial region. [precordia + G. algos, pain]

precordium (pre-kor′de-um)
Singular of precordia.

precostal (pre-kos′tal)
Anterior to the ribs. [pre- + L. costa, rib]

precritical (pre-krit′i-kal)
Relating to the phase before a crisis.

precuneal (pre-koo′ne-al)
Anterior to the cuneus.

precuneate (pre-koo′ne-at)
Relating to the precuneus.

precuneus (pre-koo′ne-us) [TA]
A division of the medial surface of each cerebral hemisphere between the cuneus and the paracentral lobule; it lies above the subparietal sulcus and is bounded anteriorly by the marginal branch of the cingulate sulcus and posteriorly by the parietooccipital sulcus. SYN: lobulus quadratus (2) , quadrate lobe (3) , quadrate lobule (2) . [pre- + L. cuneus, a wedge]

precursor (pre-ker′ser)
That which precedes another or from which another is derived, applied especially to a physiologically inactive substance that is converted to an active enzyme, vitamin, hormone, etc., or to a chemical substance that is built into a larger structure in the course of synthesizing the latter. [L. praecursor, fr. prae-, pre- + curro, to run]

predentin (pre-den′tin)
The organic fibrillar matrix of the dentin before its calcification.

prediabetes (pre′di-a-be′tez)
A state of potential diabetes mellitus, with normal glucose tolerance but with an increased risk of developing diabetes, ( e.g., family history). Term declared obsolete by American Diabetes Association.

prediastole (pre-di-as′to-le)
The interval in the cardiac rhythm immediately preceding diastole. SYN: late systole.

prediastolic (pre-di-a-stol′ik)
Late systolic, relating to the interval preceding cardiac diastole.

predicrotic (pre-di-krot′ik)
Preceding the dicrotic notch.

predigestion (pre-di-jes′chun)
The artificial initiation of digestion of proteins (proteolysis) and starches (amylolysis) before they are eaten.

predispose (pre′dis-poz)
To render susceptible.

predisposition (pre′dis-po-zish′un)
A condition of special susceptibility to a disease.

prednisolone (pred-nis′o-lon)
A dehydrogenated analog of cortisol with the same actions and uses as cortisol; a potent glucocorticoid. p. acetate same uses as p.; suitable for intramuscular administration. p. butylacetate SYN: p. tebutate. p. sodium phosphate more soluble than p. and the other p. esters and useful when a rapid onset or a short duration of action is desired; suitable for intrasynovial, parenteral, and topical administration. p. succinate p. compound suitable for intramuscular, intravenous, or rectal administration. p. tebutate same actions and uses as p. but with longer duration of action and suitable for intrasynovial and soft tissue injection. SYN: p. butylacetate.

prednisone (pred′ni-son)
A dehydrogenated analogue of cortisone with the same actions and uses; must be converted to prednisolone before active; inhibits proliferation of lymphocytes.

prednylidene (pred-nil′i-den)
A glucocorticoid.

predormital (pre-dor′mi-tal)
Pertaining to the predormitum.

predormitum (pre-dor′mi-tum)
The stage of semi-unconsciousness preceding actual sleep. [pre- + L. dormio, to sleep]

preductal (pre-duk′tal)
Relating to that part of the aorta proximal to the aortic opening of the ductus arteriosus.

preeclampsia (pre-e-klamp′se-a)
Development of hypertension with proteinuria or edema, or both, due to pregnancy or the influence of a recent pregnancy; it usually occurs after the 20th week of gestation, but may develop before this time in the presence of trophoblastic disease. [pre- + G. eklampsis, a shining forth (eclampsia)] superimposed p. the development of p. in a patient with chronic hypertensive vascular or renal disease; when the hypertension antedates the pregnancy as established by previous blood pressure recordings, a rise in the systolic pressure of 30 mmHg or a rise in the diastolic pressure of 15 mmHg and the development of proteinuria or edema, or both, are required during pregnancy to establish the diagnosis.

preepiglottic (pre′ep-i-glot′ik)
Anterior to the epiglottis.

preeruptive (pre-e-rup′tiv)
Denoting the stage of an exanthematous disease preceding the eruption.

preexcitation (pre′ek-si-ta′shun)
Premature activation of part of the ventricular myocardium by an impulse that travels by an anomalous path and so avoids physiologic delay in the atrioventricular junction; an intrinsic part of the Wolff-Parkinson-White syndrome. ventricular p. See Wolff-Parkinson-White syndrome.

preformation
See p. theory.

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