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Medical Dictionary


pilosebaceous (pi′lo-se-ba′shus)
Relating to the hair follicles and sebaceous glands. [pilo- + L. sebum, suet]

pilosis (pi-lo′sis)
SYN: hirsutism. [pilo- + G. -osis, condition]

Jan, Polish neurologist, 1870–1931. See P. sign, Westphal-P. phenomenon.

pilula, gen. and pl. pilulae (pil′u-la, -le)
A pill or pilule. [L. dim. of pila, a ball]

pilular (pil′u-lar)
Relating to a pill.

pilule (pil′ul)
A small pill. [L. pilula]

pilus, pl .pili (pi′lus, pi′li) [TA]
1. [TA] SYN: hair (1) . 2. A fine filamentous appendage, somewhat analogous to the flagelium, that occurs on some bacteria. Pili consist only of protein and are shorter, straighter, and much more numerous and may be chemically similar to flagella; specialized pili (F pili, I pili, and other conjugative pili) seem to mediate bacterial conjugation. SYN: fimbria (2) . SEE ALSO: conjugative plasmid. [L.] pili annulati SYN: ringed hair. F pili p. (2) . F p. a structure responsible for attachment of individual male (F+) to female (F−) bacteria, forming conjugal pairs. I pili p. (2) . pili multigemini the presence of several hairs in a single follicle. R pili specialized pili found on bacterial cells, similar to F pili and associated with R plasmids. pili torti a condition in which many hair shafts are twisted on the long axis, congenital or acquired as a result of distortion of the follicles from a scarring inflammatory process, mechanical stress, or cicatrizing alopecia; the hair shafts resemble spangles in reflected light, are brittle, and break at varying lengths with many areas appearing bald with a dark stubble; as a developmental defect it can be manifested in such syndromes as Bjornstad, Crandall, and Menkes. SYN: twisted hairs.

pimaricin (pi-mar′i-sin)
An antifungal antibiotic for topical use, produced by Streptomyces natalensis; effective against Aspergillus, Candida, and Mucor species. SYN: natamycin.

pimelic acid (pi-mel′ik)
Heptanedioic acid;an intermediate in the oxidation of oleic acid in some microorganisms; a precursor of biotin.

Fat, fatty. [G. pimele, soft fat, lard, fr. piar, fat]

pimelorrhea (pim′e-lo-re′a)
SYN: fatty diarrhea. [pimelo- + G. rhoia, a flux]

pimelorthopnea (pim′e-lor-thop′ne-a, -ne′a)
Orthopnea; difficulty breathing in any but the erect posture, due to obesity. SYN: piorthopnea. [pimelo- + G. orthos, straight, + pnoe, breath]

pimenta, pimento (pi-men′ta, -to)
The dried fruit of P. officinalis (family Myrtaceae), a tree native in Jamaica and other parts of tropical America, used as a carminative and aromatic spice; p. oil comprises 3 to 4% of the dried fruit. [Sp. fr. L. pigmentum, paint (Mediev. L. spice)] p. oil comprises 3–4.5% of the dried fruit. SYN: allspice oil.

pimozide (pim′o-zid)
A tranquilizing antipsychotic drug.

pimple (pim′pl)
A papule or small pustule; usually meant to denote an inflammatory lesion of acne.

Abbreviation for prostatic intraepithelial neoplasia.

A metallic implant used in surgical treatment of bone fractures. SEE ALSO: nail. [O.E. pinn, fr. L. pinna, feather] Steinmann p. a p. that is used to transfix bone for traction or fixation.

pinacyanol (pin-a-si′a-nol) [old C.I. 808]
A basic dye, used as a color sensitizer (violet red in water, blue in alcohol) in photography and for vital staining of leukocytes.

Adolphe, French obstetrician, 1844–1934. See P. maneuver.

pincement (pans-mon′)
A pinching manipulation in massage. [Fr. pinching]

occupational therapy Grip between fingers at the most distal joints.

Jens J., Danish oral pathologist, 1921–1995. See P. tumor.

pindolol (pin′do-lol)
A β-adrenergic blocking agent used in the treatment of hypertension; also possesses intrinsic sympathomimetic activity.

pine (pin)
An evergreen coniferous tree of the genus Pinus (family Pinaceae), various species of which yield tar, turpentine, resin, and volatile oils. [L. pinus, a p. tree] p.-needle oil a volatile oil distilled with steam from the fresh leaf of Pinus mugo; has been used by inhalation and spray in catarrhal affections of the air passages, and locally in rheumatism; also used as a flavoring and in perfumery. p. oil the volatile oil from the wood of Pinus palustris and other species of Pinus; used as a deodorant and disinfectant. p. tar obtained by the destructive distillation of the wood of Pinus palustris and other species of Pinus; used internally as an expectorant and externally in the treatment of skin diseases. SYN: liquid pitch. white p. the dried inner bark of Pinus strobus, used as an ingredient in cough syrups.

pineal (pin′e-al)
1. Shaped like a pine cone. SYN: piniform. 2. Pertaining to the p. body. [L. pineus, relating to the pine, pinus]

pinealectomy (pin′e-a-lek′to-me)
Removal of the pineal body. [pineal + G. ektome, excision]

pinealocyte (pin-e′al-o-sit)
A cell of the pineal body with long processes ending in bulbous expansions. Pinealocytes receive a direct innervation from sympathetic neurons that form recognizable synapses. The club-shaped endings of p. processes terminate in perivascular spaces surrounding capillaries. SYN: chief cell of corpus pineale, parenchymatous cell of corpus pineale. [pineal + G. kytos, cell]

pinealoma (pin′e-a-lo′ma)
A term that has been variably used to designate germ cell tumors, pineocytomas, and pineoblastomas of the pineal gland. [pineal + G. -oma, tumor] ectopic p. an obsolete term for an undifferentiated neoplasm resembling a p., usually found near the pituitary gland; believed by some to be an undifferentiated teratoma. extrapineal p. obsolete term for ectopic p..

pinealopathy (pin′e-a-lop′a-the)
Disease of the pineal gland. [pineal + G. pathos, disease]

pineapple (pin′ap-el)
The fruit of Ananas sativa or Bromelia ananas (family Bromeliaceae); it contains a proteolytic and milk-clotting enzyme, bromelain.

Philippe, French psychiatrist, 1745–1826. See P. system.

pineoblastoma (pin′e-o-blas-to′ma)
A poorly differentiated tumor of the pineal gland most frequently occurring in the first three decades of life consisting of small cells with a scant amount of cytoplasm and often forming pseudorosettes; histologically resembles a medulloblastoma; a type of primitive neuroectodermal tumor. [pineal + G. blastos, germ, + -oma, tumor]

pineocytoma (pin′e-o-ci′to′ma)
A tumor arising in the pineal gland that resembles normal pineal parenchyma.

ping-pong (ping′pong)
See ping-pong mechanism. [Ping-Pong, trademark for table tennis]

pinguecula, pinguicula (ping-gwek′u-la)
A yellowish accumulation of connective tissue that thickens the conjunctiva; occurs in the aged. [L. pinguiculus, fattish, fr. pinguis, fat]

piniform (pin′i-form, pi′ni-)
SYN: pineal (1) . [L. pinus, pine, + forma, form]

pinkeye (pink′i)
SYN: acute contagious conjunctivitis.

pinledge (pin′ledj)
A cast metal dental restoration or technique that employs parallel pins as part of the casting to increase retention of the restoration.

pinna, pl .pinnae (pin′a, pin′e)
1. SYN: auricle (1) . 2. A feather, wing, or fin. [L. p. or penna, a feather, in pl. a wing] p. nasi SYN: ala of nose.

pinnal (pin′al)
Relating to the pinna.

pinniped (pin′i-ped)
A member of the suborder Pinnipedia, aquatic carnivorous mammals with all four limbs modified into flippers ( e.g., seal, walrus). [L. pinna, feather (wing), + pes (ped-), foot]

pinocyte (pin′o-sit, pi′no-)
A cell that exhibits pinocytosis. [G. pineo, to drink, + kytos, cell]

pinocytosis (pin′o-si-to′sis, pi′no-)
The cellular process of actively engulfing liquid, a phenomenon in which minute incuppings or invaginations are formed in the surface of the cell membrane and close to form fluid-filled vesicles; it resembles phagocytosis. [pinocyte + G. -osis, condition]

pinosome (pin′o-som, pi′no-)
A fluid-filled vacuole formed by pinocytosis. [G. pineo, to drink, + soma, body]

Emil, Austrian physician, 1845–1913. See P. sign, P. syndrome.

pint (pint)
A measure of quantity (U.S. liquid), containing 16 fluid ounces, 28.875 cubic inches; 473.1765 cc. An imperial p. contains 20 British fluid ounces, 34.67743 cubic inches; 568.2615 cc.

pinta (pin′ta, pen′ta)
A disease caused by a spirochete, Treponema carateum, endemic in Mexico and Central America, and characterized by a small primary papule followed by an enlarging plaque and disseminated secondary macules of varying color called pintids that finally become white. SEE ALSO: nonvenereal syphilis. SYN: azul, carate, mal del pinto. [Sp. painted]

Eruptions of plaque-like lesions in the secondary phase of pinta; the lesions, which vary in color (hypochromic, hyperchromic, and erythematosquamous), result in depigmentation. [pinta + -id(1)]

pinus (pi′nus)
SYN: pineal body. [L. a pine tree]

pinworm (pin′werm)
A member of the genus Enterobius or related genera of nematodes in the family Oxyuridae, abundant in a large variety of vertebrates, including such species as Oxyuris equi (the horse p.), Enterobius vermicularis (the human p.), Syphacia and Aspiculuris species (the mouse p.), Passalurus ambiguus (the rabbit p.), and Syphacia muris (the rat p.). SYN: seatworm.

Piophila casei (pi-of′i-la ka′se-i)
The cheese fly, a species of muscoid flies whose eggs are deposited on exposed cheese, cured meats, and other foods and are thus ingested, sometimes giving rise to temporary intestinal myiasis, with diarrhea, colicky pains, and vomiting. [L., fr. G. pion, fat, + philos, fond; L. caseus, cheese]

piorthopnea (pi-or-thop′ne-a, -ne′a)
SYN: pimelorthopnea. [G. pion, fat, + orthos, straight, + pnoe, breath]

Abbreviation for phosphatidylinositol 4,5-bisphosphate.

pipamazine (pi-pam′a-zen)
A phenothiazine analogue with antiemetic and tranquilizing properties.

pipamperone (pi-pam′per-on)
An antipsychotic tranquilizer.

pipazethate (pi-paz′e-that)
An antitussive agent.

pipecolic acid (pip′e-ko′lik, -kol′ik)
Dihydrobaikiaine; 2-piperidinecarboxylic acid; saturated picolinic acid;the l-isomers of the Δ1- and Δ6-dehydropipecolic acids are intermediates in the catabolism of l-lysine; p. accumulates in disorders of the peroxisomes. SYN: homoproline, pipecolinic acid.

pipecolinic acid (pip-e-ko-lin′ik, -kol′i-nik)
SYN: pipecolic acid.

pipecuronium (pip′e-kur-o′ne-um)
A nondepolarizing steroid muscle relaxant structurally related to pancuronium and characterized by long duration of action.

pipecuronium bromide (pi-pe-kur-o′ne-um bro′mid)
A neuromuscular blocking agent with nondepolarizing properties, thus resembling d-tubocurarine but having a shorter duration of paralytic action.

pipenzolate methylbromide (pi-pen′zo-lat)
An anticholinergic drug.

E.B., U.S. obstetrician-gynecologist, 1881–1935. See P. forceps.

piper (pi′per)
Black pepper, the dried unripe fruit of P. nigrum (family Piperaceae), a climbing plant of the East Indies; used as a condiment, diaphoretic, stimulant, and carminative, and locally as a counterirritant. [L. pepper]

piperacillin sodium (pi-per′a-sil′in)
A semisynthetic extended spectrum penicillin active against a wide variety of Gram-positive and Gram-negative bacteria.

piperazine (pi-per′a-zen, -zin)
Its former use in gout was based upon its property of dissolving uric acid in vitro, but it is ineffective in increasing uric acid excretion; its compounds are now used as anthelmintics in oxyuriasis and ascariasis. SYN: diethylenediamine. p. adipate a veterinary anthelmintic and filaricide. p. calcium edetate an anthelmintic. p. citrate a vermifuge for pinworms and roundworms. p. estrone sulfate a purified preparation of natural estrone sulfate; the p. acts as a buffer to increase the stability of estrone sulfate. p. tartrate an anthelmintic useful in the treatment of nematode infestation.

piperazine diethanesulfonic acid (PIPES)
One of several aminosulfonic acids (like HEPES) used in biologic buffers; active range, 6.0–8.5.

piperidine (pi′per-i-den)
1. Hexahydropyridine;a compound from which are derived phenothiazine antipsychotics such as thioridazine hydrochloride and mesoridazine besylate. 2. One of a class of alkaloids containing a p. (1) moiety.

piperidolate hydrochloride (pi-per′i-do-lat)
An anticholinergic agent.

piperocaine hydrochloride (pip′er-o-kan, pi′per-)
A rapidly acting local anesthetic for infiltration and nerve blocks.

piperoxan hydrochloride (pip-er-ok′san)
An adrenergic (α-receptor blocking agent of the Fourneau series of benzodioxanes); used as a diagnostic test for pheochromocytoma. SYN: Fourneau 933.

Abbreviation for piperazine diethanesulfonic acid.

pipette, pipet (pi-pet′, pi-pet′)
A graduated tube (marked in mL) used to transport a definite volume of a gas or liquid in laboratory work. [Fr. dim. of pipe, pipe] blowout p. a p. calibrated to deliver its nominal volume by permitting it first to drain and then blowing out the last drop held in the tip. graduated p. a p. with a plain, narrow tube drawn out to a tip and graduated uniformly along its length. Calibration marks may be confined to the stem (Mohr p.) or extend to the tip (serologic p.). Mohr p. See graduated p.. Pasteur p. a cotton-plugged, glass tube drawn out to a fine tip, used for the sterile transfer of small volumes of fluid. serologic p. See graduated p..

pipobroman (pip-o-bro′man)
An alkylating agent used in polycythemia vera and chronic granulocytic leukemia.


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