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Medical Dictionary


Max A., U.S. dentist, 1903–1965. See P. curve.

plectridium (plek-trid′e-um)
A bacterial rod-shaped cell that contains a spore at one end, imparting a drumstick shape to the cell, such as the spore-containing cells in the organism causing tetanus, Clostridium tetani. [Mod. L. dim. of G. plektron, an instrument to strike with]

pledget (plej′et)
A tuft of wool, cotton, or lint.

Paralysis. [G. plege, stroke]

Rarely used alternative spelling for pleo-.

pleiotropic (pli-o-trop′ik)
Denoting, or characterized by, pleiotropy. SYN: polyphenic.

pleiotropy, pleiotropia (pli-ot′ro-pe, pli′o-tro′pe-a)
Production by a single mutant gene of apparently unrelated multiple effects at the clinical or phenotypic level. [pleio- + G. tropos, turning] functional p. the p. due to the participation of the same allelic change in multiple otherwise distinct processes; e.g., heparin is active in many body reactions including coagulation and the metabolism of fat. structural p. a p. that occurs when two or more regions of a polypeptide may have quite distinct and unrelated biologic functions that share nothing in common except that they are transcribed and translated at the same time.

Pleistophora (plis-tof′er-ah)
A genus of microsporidians in the protozoan phylum Microspora, commonly found in fish and insects, with mononucleate, thick-walled spores in clusters of more than eight. An undescribed but distinct species of P. was implicated as the cause of a disseminated microsporidial myositis in an immunocompromised male patient.

more. [G. pleion]

pleochroic (ple-o-kro′ik)
SYN: pleochromatic. [pleo- + G. chroa, color]

pleochroism (ple-ok′ro-izm)
SYN: pleochromatism.

pleochromatic (ple-o-kro-mat′ik)
Relating to pleochromatism. SYN: pleochroic.

pleochromatism (ple-o-kro′ma-tizm)
Property of showing changes of color when illuminated along different axes, as certain crystals or liquids. SYN: pleochroism. [pleo- + G. chroma, color]

pleocytosis (ple′o-si-to′sis)
Presence of more cells than normal, often denoting leukocytosis and especially lymphocytosis or round cell infiltration; orginally applied to the lymphocytosis of the cerebrospinal fluid present in syphilis of the central nervous system. [pleo- + G. kytos, cell, + -osis, condition]

pleomastia, pleomazia (ple-o-mas′te-a, -ma′ze-a)
SYN: polymastia. [pleo- + G. mastos, breast]

pleomorphic (ple-o-mor′fik)
1. SYN: polymorphic. 2. Among fungi, having two or more spore forms; also used to describe a sterile mutant dermatophyte resulting from degenerative changes in culture.

pleomorphism (ple-o-mor′fizm)
SYN: polymorphism. [pleo- + G. morphe, form]

pleomorphous (ple-o-mor′fus)
SYN: polymorphic.

pleonasm (ple′o-nazm)
Excess in number or size of parts. [G. pleonasmos, exaggeration, excessive, fr. pleion, more]

pleonosteosis (ple′on-os-te-o′sis)
Superabundance of bone formation. [pleo- + G. osteon, bone, + -osis, condition] Leri p. SYN: dyschondrosteosis.

pleoptics (ple-op′tiks)
A term introduced by Bangerter to include all forms of treatment for amblyopia, particularly that associated with eccentric fixation. [pleo- + optics]

pleoptophor (ple-op′to-for)
An instrument for the treatment of amblyopia. [pleo- + G. optos, visible, + phoros, bearing]

plerocercoid (ple-ro-ser′koyd)
A stage in the development of a tapeworm following the procercoid stage, which develops in an animal serving as the second or subsequent intermediate host; a wormlike nonsegmented larva with an invaginated scolex at one end, usually unencysted in the flesh of various fishes, reptiles, or amphibians, the ingestion of which transmits the parasite to the final host. SEE ALSO: Diphyllobothrium latum. [G. pleres, full, complete, + kerkos, tail]

Nearness, similarity. [G. plesios, close, near]

A genus of Gram-negative, facultatively anaerobic, chemoorganotropic, rod-shaped, motile bacteria. It possesses the enterobacterial common antigen. This genus is found in fish and other aquatic animals and in some other animals. Associated with diarrhea and occasional opportunistic infection in humans. P. shigelloides species that is an enteric pathogen and an etiologic agent of various extraintestinal infections transmitted to humans in contaminated food or water or as a colonizer of various animals. This is the only species in the genus and has also been referred to as Pseudomonas s., Aeromonas s., C57, and Vibrio s.

plesiomorphic (ple′se-o-mor′fik)
Similar in form. SYN: plesiomorphous.

plesiomorphism (ple′se-o-mor′fizm)
Similarity in form. [plesio- + G. morphe, form]

plesiomorphous (ple′se-o-mor′fus)
SYN: plesiomorphic.

pless-, plessi-
A striking, especially percussion. [G. plesso, to strike]

plessesthesia (ples-es-the′ze-a)
SYN: palpatory percussion. [G. plesso, to strike, + aisthesis, sensation]

plessimeter (ple-sim′e-ter)
An oblong flexible plate used in mediate percussion by being placed against the surface and struck with the plessor. SYN: pleximeter, plexometer. [G. plesso, to strike, + metron, measure]

plessimetric (ples-i-met′rik)
Relating to a plessimeter.

plessor (ples′er)
A small hammer, usually with soft rubber head, used to tap the part directly, or with a plessimeter, in percussion of the chest or other part. SYN: percussor, plexor. [G. plesso, to strike]

plethora (pleth′o-ra)
1. SYN: hypervolemia. 2. An excess of any of the body fluids. [G. plethore, fullness, fr. pletho, to become full]

plethoric (ple-thor′ik, pleth′o-rik)
Relating to plethora. SYN: sanguine (1) , sanguineous (2) .

plethysmograph (ple-thiz′mo-graf)
A device for measuring and recording changes in volume of a part, organ, or whole body. [G. plethysmos, increase, + grapho, to write] body p. a chamber apparatus surrounding the entire body, commonly used in studies of respiratory function. digital p. p. applied to a digit of a hand or foot to measure skin blood flow. pressure p. 1. a p. applied to part of the body, e.g., a limb segment, and arranged so that volume is measured during temporary application of sufficient pressure to the part to empty its blood vessels; 2. a body p. in which changes of body volume are measured in terms of the consequent changes in air pressure in the body p.. volume-displacement p. a p., usually a body p., in which changes in volume displace a corresponding volume into or out of a very compliant measuring device, such as a Krogh spirometer or integrating flowmeter.

plethysmography (pleth-iz-mog′ra-fe)
Measuring and recording changes in volume of an organ or other part of the body by a plethysmograph. [G. plethysmos, increase, + graphe, a writing] impedance p. recording changes in electrical impedance between electrodes placed on opposite sides of a part of the body, as a measure of volume changes in the path of the current. SYN: dielectrography. venous occlusion p. measurement of the rate of arterial inflow into an organ or limb segment by measuring its initial rate of increase in volume when its venous outflow is suddenly occluded.

plethysmometry (pleth-iz-mom′e-tre)
Measuring the fullness of a hollow organ or vessel, as of the pulse. [G. plethysmos, increase, + metron, measure]

pleur-, pleura-, pleuro-
Rib, side, pleura. [G. pleura; a rib, the side]

pleura, gen. and pl. pleurae (ploor′a, ploor′e) [TA]
The serous membrane enveloping the lungs and lining the walls of the pleural cavity. SYN: membrana succingens. [G. p., a rib, pl. the side] cervical p. [TA] the dome-shaped roof of the pleural cavity extending up through the superior aperture of the thorax. SYN: cupula pleurae [TA] , dome of p.&star, pleural cupula&star. costal p. SYN: costal part of parietal p.. p. costalis SYN: costal part of parietal p.. diaphragmatic p. SYN: diaphragmatic part of parietal p.. p. diaphragmatica SYN: diaphragmatic part of parietal p.. mediastinal p. SYN: mediastinal part of parietal p.. p. mediastinalis SYN: mediastinal part of parietal p.. parietal p. [TA] that which lines the different parts of the wall of the pleural cavity; called costal, diaphragmatic, and mediastinal, according to the parts invested. SYN: p. parietalis [TA] . p. parietalis [TA] SYN: parietal p.. p. pericardiaca, pericardial p. that portion of the mediastinal p. that is fused with the pericardium. phrenic p. SYN: diaphragmatic part of parietal p.. p. phrenica SYN: diaphragmatic part of parietal p.. p. pulmonalis visceral p.. pulmonary p. visceral p.. visceral p. [TA] the layer investing the lungs and dipping into the fissures between the several lobes. SYN: p. visceralis [TA] , p. pulmonalis&star, pulmonary p.&star. p. visceralis [TA] SYN: visceral p..

pleuracentesis (ploor′a-sen-te′sis)
SYN: thoracentesis.

pleural (ploor′al)
Relating to the pleura.

pleural crackles (krak′lz)
Sounds heard on auscultation of the chest as a result of inflammation of the pleura with fibrinous exudate.

pleuralgia (ploo-ral′je-a)
Rarely used synonym for pleurodynia (2). [pleur- + G. algos, pain]

pleurapophysis (ploor′a-pof′i-sis)
A rib, or the process on a cervical or lumbar vertebra corresponding thereto. Cf.:superior articular process. [pleur- + G. apophysis, process, offshoot]

pleurectomy (ploo-rek′to-me)
Excision of pleura, usually parietal. [pleur- + G. ektome, excision]

pleurisy (ploor′i-se)
Inflammation of the pleura. SYN: pleuritis. [L. pleurisis, fr. G. pleuritis] adhesive p. SYN: dry p.. benign dry p. SYN: epidemic pleurodynia. bilateral p. inflammation of the pleura on both sides of the thorax. SYN: double p.. chronic p. vague or indefinite term for long-standing inflammation of the pleura of any etiology ( e.g., tuberculosis). costal p. inflammation of the pleura lining the thoracic walls. diaphragmatic p. SYN: epidemic pleurodynia. double p. SYN: bilateral p.. dry p. p. with a fibrinous exudation, without an effusion of serum, resulting in adhesion between the opposing surfaces of the pleura. SYN: adhesive p., fibrinous p., plastic p.. encysted p. a form of serofibrinous p., in which adhesions occur at various points, circumscribing the serous effusion. epidemic benign dry p. SYN: epidemic pleurodynia. epidemic diaphragmatic p. SYN: epidemic pleurodynia. fibrinous p. SYN: dry p.. hemorrhagic p. p. with an effusion of blood-stained serum. interlobular p. inflammation limited to the pleura in the sulci between the pulmonary lobes. mediastinal p. inflammation of the portion of the pleura lining the mediastinal surface of the lung. plastic p. SYN: dry p.. productive p. SYN: pachypleuritis. proliferating p. p. with a tendency for the proliferation of inflammatory exudate. pulmonary p. inflammation of the pleura covering the lungs. SYN: visceral p.. purulent p. p. with empyema. SYN: suppurative p.. sacculated p. p. with the inflammatory exudate divided into separate regions by adhesions or inflammatory changes. serofibrinous p. the more common form of p., characterized by a fibrinous exudate on the surface of the pleura and an extensive effusion of serous fluid into the pleural cavity. serous p. SYN: p. with effusion. suppurative p. SYN: purulent p.. typhoid p. obsolete term for acute or subacute p. with typhoid symptoms (confusion or dementia). visceral p. SYN: pulmonary p.. wet p. SYN: p. with effusion. p. with effusion p. accompanied by serous exudation. SYN: serous p., wet p..

pleuritic (ploo-rit′ik)
Pertaining to pleurisy.

pleuritis (ploo-ri′tis)
SYN: pleurisy. [G. fr. pleura, side, + -itis, inflammation]

pleuritogenous (ploor-i-toj′e-nus)
Tending to produce pleurisy. [G. pleuritis, pleurisy, + genesis, origin]

See pleur-.

pleurocele (ploor′o-sel)
SYN: pneumonocele. [pleuro- + G. kele, hernia]

pleurocentesis (ploor′o-sen-te′sis)
SYN: thoracentesis. [pleuro- + G. kentesis, puncture]

pleurocentrum (ploor′o-sen′trum)
One of the lateral halves of the body of a vertebra. [pleuro- + G. kentron, center]

pleuroclysis (ploor-ok′li-sis)
Washing out of the pleural cavity. [pleuro- + G. klysis, a washing out]

pleurodesis (ploor-od′e-sis)
The creation of a fibrous adhesion between the visceral and parietal layers of the pleura, thus obliterating the pleural cavity; it is performed surgically by abrading the pleura or by inserting a sterile irritant into the pleural space, and applied as treatment in cases of malignant pleural effusion, recurrent spontaneous pneumothorax, and chylothorax. [pleuro- + G. desis, a binding together]

pleurodynia (ploor-o-din′e-a)
1. Pleuritic pain in the chest. 2. A painful affection of the tendinous attachments of the thoracic muscles, usually of one side only. SYN: costalgia. [pleuro- + G. odyne, pain] epidemic p. an acute infectious disease usually occurring in epidemic form, characterized by paroxysms of pain, usually in the chest, and associated with strains of Enterovirus coxsackievirus type B. SYN: benign dry pleurisy, Bornholm disease, Daae disease, devil grip, diaphragmatic pleurisy, epidemic benign dry pleurisy, epidemic diaphragmatic pleurisy, epidemic myalgia, epidemic myositis, myositis epidemica acuta, epidemic transient diaphragmatic spasm, Sylvest disease.

pleurogenic (ploor-o-jen′ik)
Of pleural origin; beginning in the pleura. SYN: pleurogenous (1) . [pleuro- + G. -gen, producing]

pleurogenous (ploor-oj′e-nus)
1. SYN: pleurogenic. 2. In fungi, denoting spores or conidia developed on the sides of a conidiophore or hypha.

pleurography (ploor-og′ra-fe)
Radiography of the pleural cavity after injecting contrast medium. [pleuro- + G. grapho, to write]

pleurohepatitis (ploor′o-hep-a-ti′tis)
Hepatitis with extension of the inflammation to the neighboring portion of the pleura. [pleuro- + G. hepar, liver, + -itis, inflammation]

pleurolith (ploor′o-lith)
A concretion in the pleural cavity. SYN: pleural calculus. [pleuro- + G. lithos, stone]

pleurolysis (ploor-ol′i-sis)
Locating pleural adhesions by the aid of an endoscope and then dividing them with the electric cautery. [pleuro- + G. lysis, dissolution]

pleuropericardial (ploor′o-per-i-kar′de-al)
Relating to both pleura and pericardium.

pleuropericarditis (ploor′o-per-i-kar-di′tis)
Combined inflammation of the pericardium and of the pleura. [pleuro- + pericardium + G. -itis, inflammation]

pleuroperitoneal (ploor′o-per-i-to-ne′al)
Relating to both pleura and peritoneum.


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