protiodide - psammous
that one of the series of iodides of the same base which contains the smallest amount of iodine.
a synthetic preparation of thyrotropin-releasing hormone, used in diagnosis of mild hyperthyroidism and Graves' disease, and in differentiating among primary, secondary, and tertiary hypothyroidism.
any member of the kingdom Protista; a single-celled organism.
the higher protists, comprising those organisms having a true nucleus. See Protista.
the lower protists, comprising those organisms lacking a true nucleus. See Monera.
[Gr. prōtista the very first, from prōtos first]
in the classification of living organisms, a kingdom comprising unicellular organisms with distinct nuclei (the eukaryotes), including protozoa, algae (except blue-green “algae,” which are now classified as bacteria), and certain intermediate forms.
protium (pro·ti·um) (1H)
the mass one isotope of hydrogen; ordinary, or light, hydrogen. See hydrogen. Cf. deuterium and tritium.
[Gr. prōtos first]
1. a combining form meaning first or primitive.
2. in chemistry, a prefix denoting the member of a series of compounds with the lowest proportion of the element or radical to
which it is affixed.
a primary proteose.
a toxic, irritating antibiotic substance that results from enzymatic breakdown of ranunculin after certain plants of the family
Ranunculaceae are eaten by an animal; toxic effects include potentially fatal ventricular fibrillation and respiratory failure.
[proto- + bio- + -logy]
the science which deals with the forms of life more minute than bacteria, such as viruses.
[proto- + -blast]
1. a cell with no cell wall; an embryonic cell.
2. the nucleus of an oocyte.
3. a blastomere from which a particular organ or part develops.
pertaining to a protoblast.
[proto- + Gr. brochos mesh]
denoting the first stage in the development of an ovary.
a genus of flies whose larvae feed on nesting birds.
[proto- + karyon]
a cell nucleus formed of a single karyosome in a network of linin.
protocatechuic acid (pro·to·cat·e·chu·ic ac·id)
3,4-dihydroxybenzoic acid, a catabolite of epinephrine.
that one of a series of chlorides of the same element which contains the least amount of chlorine.
a substance in plant tissue which is changed by the action of light into chlorophyll.
pertaining to the protochondrium or to centers of chondrification.
[proto- + Gr. chondros cartilage]
the basophil substance developed from precartilage which constitutes the intermediate stage in cartilage formation.
[proto- + ciliate]
in former systems of classification, a subclass of ciliate protozoa, the members of which have been assigned to the subphylum
[proto- + Gr. kokkos berry]
an order of parasitic protozoa (subclass Coccidia, class Sporozoea) found in invertebrates, the life cycle of which involves
gametogony and sporogony.
1. an explicit, detailed plan of an experiment, procedure, or test.
2. the original notes made on a necropsy, experiment, or case of disease.
, Balke-Ware p.
a procedure for assessing cardiovascular health using a graded treadmill exercise test in which the treadmill speed is held
constant and its slope increased, with the incremental increases in work so closely spaced as to approach continuity.
a procedure for assessing cardiovascular health using uphill treadmill walking in a graded exercise test; each interval is
at a specific load level for three minutes and is followed by another at a prescribed incremental increase in treadmill speed
a procedure for assessing cardiovascular health using a graded treadmill exercise test; over six stages the treadmill speed
is incrementally raised five times and its slope is raised once.
modified Bruce p.
an alteration in the Bruce protocol so that the treadmill is initially horizontal rather than uphill, with the first few intervals
increasing the treadmill slope only.
a procedure for assessing cardiovascular health using a graded treadmill exercise test; the selected treadmill speed remains
constant through the test but the treadmill slope is raised at the end of each two-minute increment.
[proto- + Gr. kōnos cone]
the principal mesiolingual cusp of the upper molar of man and certain mammals, such as the opossum and dog.
[proto- + Gr. kōnos cone + -id]
the mesiobuccal cusp of the lower molars of primitive mammals and man, being greatly modified in many higher mammals and completely
disappearing in some.
1. symbiosis in which both populations (or individuals) gain from the association but are able to survive without it.
2. the tendency of animals to cluster in groups and thereby to mutually facilitate the survival of individual organisms.
pertaining to early diastole, i.e., immediately following the second heart sound.
the first or proximal portion of the duodenum, extending from the pylorus to the duodenal papilla, and developed embryonically
from the foregut.
the first elongated unit appearing in the process of formation of any type of fiber.
[proto- + gaster]
a primary product formed in the digestion of globulin.
[proto- + gonocyte]
one of the two cells resulting from division of the zygote; in certain lower forms this constitutes the primordial germ cell
from which all gametes derive.
a heme in which the porphyrin is protoporphyrin; an example is protoheme IX, the heme found in hemoglobin.
protoheme in which the iron atom is oxidized to the +3 oxidation state.
[proto- + Gr. mastix whip]
[proto- + Gr. monas unit]
[Gr. prōton, from prōtos first]
an elementary particle of positive charge which forms the nucleus of the ordinary hydrogen atom of mass 1; along with neutrons,
protons form the nuclei of atoms of all other elements. The proton is the unit of positive electricity; it has one quantum
of charge (1.6 ×10-19 coulomb), equivalent to the electron but of opposite polarity, and its mass is 1.67 ×10-27 kilogram, approximately that of the hydrogen ion. Symbol p.
that one of several nitrates of the same base which contains the least amount of nitric acid.
trademark for preparations of pantoprazole sodium.
a normal cellular gene that with alteration, such as by mutation, DNA rearrangement, or nearby insertion of viral DNA, becomes
an active oncogene; most proto-oncogenes are believed to normally function in cell growth and differentiation. See also oncogene.
trademark for preparations of pralidoxime.
[proto- + path- + -ic]
primary; idiopathic. See protopathic sensibility, under sensibility.
any of the precursor polysaccharides from which are derived pectins; they occur in a variety of plants, in the fruits, roots,
leaves, and stems.
a colorless substance which is changed into chlorophyll by the action of air or carbon dioxide.
[proto- + Gr. phyton plant]
in former systems of classification, the lowest division of the plant kingdom, consisting of the algae and variously defined
to include also the blue-green algae, yeasts, fungi, lichens, bacteria, or viruses.
trademark for preparations of tacrolimus.
1. an alkaloid from Eschscholtzia californica, the California poppy, and many other plants; it is an anodyne and hypnotic.
2. a poisonous alkaloid from various species of perennial herbs of the genus Dicentra.
primary formation of tissue.
[proto- + -plasm]
the viscid, translucent, polyphasic colloid with water as the continuous phase that makes up the essential material of all
plant and animal cells. It is composed mainly of nucleic acids, proteins, lipids, carbohydrates, and inorganic salts. The
protoplasm surrounding the nucleus is known as the cytoplasm and that composing the nucleus is the nucleoplasm.
protoplasm having granular inclusions.
pertaining to or consisting of protoplasm.
[proto- + -plast]
a bacterial, yeast, or fungal cell that results after complete removal of the rigid cell wall, which forms a membrane-bound
cell into a spherical shape that is dependent for its integrity on an isotonic or hypertonic medium. Cf. spheroplast.
erythropoietic p. (EPP)
an autosomal dominant disorder caused by a partial deficiency of ferrochelatase, characterized by increased levels of protoporphyrin in the erythrocytes, plasma, liver, and feces and a wide variety of photosensitive skin changes, ranging from a burning or
pruritic sensation to erythema, plaquelike edema, and wheals. It is generally classified as an erythropoietic porphyria, but in classification schemes that include also the category erythrohepatic porphyria, it is classified there.
the porphyrin produced by oxidation of the methylene bridge of protoporphyrinogen. Protoporphyrin IX is the only naturally occurring isomer; it is an intermediate in heme biosynthesis, combining with ferrous
iron to form protoheme IX, the heme prosthetic group of hemoglobin. It is accumulated and excreted excessively in the feces
in erythropoietic protoporphyria and variegate porphyria.
free erythrocyte p. (FEP)
protoporphyrin free in the blood rather than incorporated into erythrocytes; in the absence of iron, most is actually bound
to zinc as zinc protoporphyrin (q.v.).
free erythrocyte protoporphyrin that is bound to zinc; levels of this chelated form are elevated in iron deficiency and lead poisoning while it is the nonchelated
form that is elevated in erythropoietic protoporphyria, and neither is elevated in thalassemia.
a porphyrinogen (q.v.) in which two pyrrole rings each have one methyl and one propionate side chain and the other two pyrrole rings each
have one methyl and one vinyl side chain. Fifteen isomers are possible but only one, type IX, occurs naturally, produced by
oxidative decarboxylation of coproporphyrinogen; it is an intermediate in heme biosynthesis.
protoporphyrinogen oxidase (pro·to·por·phy·rin·o·gen ox·i·dase)
[EC 220.127.116.11] an enzyme of the oxidoreductase class that catalyzes the oxidation of protoporphyrinogen IX to protoporphyrin IX, the penultimate
step in heme and porphyrin synthesis. Deficiency of the enzyme, an autosomal dominant trait, causes variegate porphyria.
the presence of protoporphyrin in the blood; see also protoporphyria.
a primary proteose.
that one of a series of salts of the same base which contains the smallest amount of the substance combining with the base.
a genus of nematodes of the family Spiruridae. P. gra´cilis is found in the stomachs of cats.
the first product of progressive cleavage, a multinucleate mass of cytoplasm surrounded by cleavage planes.
trademark for a preparation of metronidazole.
[proto- + Gr. stoma mouth]
an individual of the Protostomia.
a series of the Eucoelomata, including the mollusks, annelids, and arthropods, in all of which the mouth arises from the blastopore.
a family of nematodes that includes the genera Cystocaulus, Muellerius, Neostrongylus, Parelaphostrongylus, and Protostrongylus. Several species are lungworms that infect sheep, goats, and other mammals.
a genus of nematode lungworms of the family Protostrongylidae. P. rufes´cens causes hoose or verminous bronchitis in sheep, goats, deer, and rabbits.
that one of several sulfates of the same base which contains the smallest proportion of sulfate ion.
[proto- + Gr. thēkē sheath]
a genus of ubiquitous yeastlike organisms generally considered to be achloric algae, occurring as a spherical, ovoid, or elliptical
cell containing several thick-walled autospores. P. wickerha´mii and P. zop´fii cause protothecosis in humans and domestic animals.
[proto- + theca + -osis]
infection of humans or domestic animals by organisms of the genus Prototheca, especially P. wickerhamii or P. zopfii, varying from cutaneous and subcutaneous lesions to systemic invasion involving several internal organs; in cows it may be
manifested as mastitis. It may occur as an opportunistic infection or as a result of traumatic implantation of the pathogen
into the tissues.
[proto- + Gr. thērion beast, animal]
in some systems of classification, a subclass of the Mammalia, including the order Monotremata, the egg-laying mammals.
[proto- + Gr. trophē nourishment]
a prototrophic organism.
having the same growth factor requirements as the ancestral or prototype strain; said of microbial mutants.
proton tautomerism. Cf. anionotropy.
in fungal taxonomy, a series of the subphylum Ascomycotina, consisting of those having a prototunicate ascus. Orders in this
series that contain human pathogens are Eurotiales and Onygenales.
[proto- + type]
1. the original type or form after which other types or forms are developed.
2. in microbiology, the standard reference strain to which other strains are compared.
an ester alkaloid obtained from the liliaceous plant Veratrum album L. It occurs in two forms, designated A and B, both of which have antihypertensive properties. Protoveratrine A is said to
be more active than the B form; the two are usually administered in combination.
2. the caudal half of a somite that forms most of a vertebra.
that one of a series of oxides of the same metal which contains the smallest amount of oxygen.
[proto- + Gr. zoon animal]
a subkingdom (formerly a phylum) comprising the simplest organisms of the animal kingdom, consisting of unicellular organisms
that range in size from submicroscopic to macroscopic; most are free living, but some lead commensalistic, mutualistic, or
parasitic existences. According to newer classifications, Protozoa is divided into seven phyla: Sarcomastigophora, Labyrinthomorpha,
Apicomplexa, Microspora, Acetospora, Myxozoa, and Ciliophora. Cf. Metazoa.
Click here to view image
■Cysts of intestinal protozoa: (A), Entamoeba coli; (B), E. histolytica or E. dispar; (C), E. nana; (D), Iodamoeba bütschlii.
plural of protozoon.
destructive to protozoa; an agent destructive to protozoa.
protozoan (def. 2).
1. any individual of the Protozoa; called also protozoon.
2. of or pertaining to the Protozoa; called also protozoal.
any disease caused by protozoa.
the study of protozoa.
[proto- + Gr. zōon animal]
protozoan (def. 1).
[protozoa + -phage]
a cell which has a phagocytic action on protozoa.
[L. protrahere to drag forth]
1. drawing out or lengthening.
2. extension or protrusion.
3. a condition in which the teeth or other maxillary or mandibular structures are situated anterior to their normal position.
1. the protrusive movement of the mandible initiated by the lateral and medial pterygoid muscles acting simultaneously. Cf. mandibular retraction.
2. a facial anomaly in which the gnathion lies anterior to the orbital plane.
a facial anomaly in which the subnasion is anterior to the orbital plane.
[pro- + L. trahere to draw]
an instrument for extracting bits of bone, bullets, or other foreign material from wounds.
the proenzyme of protein-glutamine γ-glutamyltransferase (transglutaminase). It is the inactive precursor form of coagulation factor XIII.
protriptyline hydrochloride (pro·trip·ty·line hy·dro·chlo·ride)
[USP] a tricyclic antidepressant of the dibenzocycloheptadiene class; it is also used in the treatment of attention-deficit/hyperactivity disorder and of narcolepsy and associated cataplexy. Administered orally.
trademark for a preparation of somatrem.
a sinking in or subsidence of the floor of the acetabulum with protrusion of the femoral head through it (intrapelvic protrusion) resulting in limitation of movement of the hip joint. Called also arthrokatadysis and Otto disease.
[L. protrudere to push forward]
the state of being thrust forward or laterally, as in masticatory movements of the mandible; see also projection (def. 3).
the projection of both the maxilla and the mandible beyond normal limits in relation to the cranial base.
bimaxillary dentoalveolar p.
the positioning of the entire dentition forward with respect to the facial profile.
herniation of intervertebral disk.
see protrusio acetabuli.
[pro- + L. tuber bulge]
a projecting part, or prominence; an apophysis, process, or swelling.
p. of chin
occipital p., external
protuberantia occipitalis externa.
occipital p., internal
protuberantia occipitalis interna.
occipital p., transverse
gen. and pl. protuberan´tiae
[L., from pro- + tuber bulge]
[TA] protuberance: a projecting part, or prominence.
mental protuberance: a more or less distinct and triangular prominence on the anterior surface of the body of the mandible, on or near the median
p. occipita´lis exter´na
external occipital protuberance: a prominence at the center of the outer surface of the squama of the occipital bone which gives attachment to the ligamentum
p. occipita´lis inter´na
internal occipital protuberance: the projection of bone at the midpoint of the cruciform eminence, on the internal surface of the squama of the occipital
bone, sometimes presenting as a ridge (crista occipitalis interna).
prourokinase (pro·uro·ki·nase) (pro-UK)
the single-chain proenzyme cleaved by plasmin to form u-plasminogen activator (urokinase); it is found circulating in plasma and urine. Although it is inactive in plasma, it is slowly activated in the presence
of fibrin clots, which it lyses via fibrin-dependent plasminogen activation. It resembles t-plasminogen activator in having both a higher specific thrombolytic activity and better fibrin specificity than does u-plasminogen activator, and it has been used for therapeutic thrombolysis. Called also single-chain urokinase-type plasminogen activator.
trademark for a preparation of protoveratrines A and B.
trademark for preparations of albuterol.
[pro- + ventriculus]
1. the glandular first portion of the stomach of birds, in which food from the crop is mixed with peptic enzymes and passed to
2. the portion of the foregut in certain invertebrates, e.g., some insects, which may function as a gizzard or as a valve into
trademark for a preparation of medroxyprogesterone acetate.
[Providence, Rhode Island]
a genus of gram-negative, facultatively anaerobic, motile, rod-shaped bacteria of the family Enterobacteriaceae, occurring
in normal urine and feces. The organisms are potential pathogens associated with urinary tract and secondary tissue infections.
It was formerly classified as a species of the genus Proteus (P. inconstans).
a species that does not ferment trehalose or myo-inositol; isolated especially from stools of children with diarrhea. Called also Proteus inconstans subgroup A.
a species isolated from human clinical specimens and from chicken feces, a possible cause of nosocomial infections. Called
also Proteus rettgeri.
a species that ferments trehalose and myo-inositol. It causes nosocomial infections and is a major agent in burn infections. Called also Proteus inconstans subgroup B.
trademark for a preparation of modafinil.
in homeopathy, the administration of a medicinal substance to healthy persons in doses large enough to elicit a symptomatic response without
causing irreversible toxicity in order to determine its therapeutic properties.
the genome of an animal virus integrated (by crossing over) into the chromosome of the host cell, and thus replicated in all
of its daughter cells. It can be activated, spontaneously or by induction, to produce a complete virus; it can also cause
transformation of the host cell.
formed or performed for temporary purposes; temporary.
a precursor of a vitamin.
usually β-carotene; however, the term is sometimes used more broadly to denote any of the provitamin A carotenoids.
challenge (def. 3).
see under challenge.
see under challenge.
stimulating the appearance of a sign, reflex, reaction, or therapeutic effect.
trademark for a preparation of methacholine chloride.
Prowazek's bodies (Pro·wa·zek's bodies)
[Stanislas Joseph Matthias von Prowazek, German zoologist, 18751915]
see under body.
Prowazek-Greeff bodies (Pro·wa·zek-Greeff bodies)
[S.J.M. von Prowazek; Carl Richard Greeff, German ophthalmologist, 18621938]
Pro-X dipeptidase (Pro-X di·pep·ti·dase)
[EC 18.104.22.168] a dipeptidase that catalyzes the cleavage of an N-terminal proline or another imino acid from imidodipeptides. Called also
prolinase and prolyl dipeptidase.
the study of the effects of spatial distance between persons interacting with each other, and of their orientation toward
toward the proximal end or in a proximal direction.
[L. proximus next]
nearest; closer to any point of reference: opposed to distal.
[TA] proximal; a term denoting proximity to the point of origin or attachment of an organ or part.
[L. proximatus drawn near]
immediate or nearest.
ataxia affecting the proximal part of a limb.
pertaining to the proximal and buccal surfaces of a posterior tooth.
pertaining to the proximal and labial surfaces of an anterior tooth.
pertaining to the proximal and lingual surfaces of a tooth.
trademark for preparations of fluoxetine hydrochloride.
1. situated before a sclerozone.
2. pertaining to a prozone.
[pro- + zone]
in an agglutination or precipitation reaction, the zone of relatively high antibody concentrations within which no reaction
occurs. As the antibody concentration is lowered below the prozone, the reaction occurs. This phenomenon may be due simply
to antibody excess (see precipitin reaction, under reaction), or it may be due to blocking antibody or to nonspecific inhibitors in serum. Called also prezone.
peripheral resistance unit.
trademark for a preparation of doxepin hydrochloride.
[L. pruina hoarfrost]
having the appearance of being covered with hoarfrost.
trademark for a preparation of oxyphenisatin acetate.
a genus of herbs of the family Labiatae, native to Europe and Asia. P. vulga´ris L. is called heal-all or self-heal and is astringent and tonic.
a genus of trees and shrubs of the family Rosaceae, including many that are cultivated for their fruit; the seeds or pits
of many varieties contain cyanogenetic compounds such as amygdalin and may cause fatal cyanide poisoning if eaten in large quantities. P. cera´sus L. is the sour cherry, a source of cherry juice. P. dul´cis Mill. is the almond, a source of almond oil and bitter almond oil. P. seroti´na Ehrh. is the wild cherry and P. virginia´na L. is the choke cherry. The pits of P. armeni´aca L. (the apricot) and P. per´sica (L.) Bastch. (the peach) yield persic oil. P. africa´na (the African plum) is the source of pygeum.
of the nature of or tending to cause prurigo.
[L. “the itch”]
any of various itchy skin eruptions of unknown cause, in which the characteristic lesion (prurigo papule) is dome-shaped with
a small transient vesicle on top, followed by crusting or lichenification; specific types are usually indicated by a modifying
a severe, chronic pruriginous dermatosis characterized chiefly by hard excoriated prurigo papules and lichenification. Called
also p. ferox.
, p. of Besnier
Besnier's p. of pregnancy
p. gestationis of Besnier.
p. chro´nica multifor´mis
a pruriginous dermatosis characterized by prurigo papules, patches of lichenification and eczematization, enlarged regional
lymph nodes, and eosinophilia.
a papular dermatosis regarded as a form of polymorphous light eruption, usually occurring in childhood during the summer months,
and sometimes improving or resolving after puberty. Called also summer p. of Hutchinson.
, p. gestationis of Besnier
an extremely pruritic condition of unknown etiology occurring in the third trimester of pregnancy, characterized by tiny crust-covered
excoriated papules mainly on the extensor surfaces of the limbs but also on the upper trunk and other areas of the body, which
leave postinflammatory residua after they resolve. It tends to clear after delivery but may recur with subsequent pregnancies.
Called also Besnier's p. of pregnancy.
p. of Hebra
a form associated with primary biliary cirrhosis in women, characterized by reticulated hyperpigmentation and intense itching.
an extremely pruritic, chronic pruriginous dermatosis beginning in early childhood, characterized by excoriations, lichenification,
and eczematization that become progressively more pronounced, and accompanied by enlarged glands and associated constitutional
symptoms. The condition may be the same as papular urticaria. Called also p. of Hebra.
a chronic, intensely pruritic form of neurodermatitis, usually occurring in women, located chiefly on the limbs, especially
the anterior thighs and legs, with single or multiple, pea-sized or larger, firm, and erythematous or brownish nodules that
become verrucous or fissured.
a form in which the prurigo papules are present in various stages of development, usually in crops, especially on the trunk
and extensor surfaces of the limbs in middle-aged persons.
summer p. of Hutchinson
1. p. estivalis.
2. hydroa vacciniforme.
pertaining to or characterized by pruritus.
capable of causing or tending to cause pruritus.
[L., from prurire to itch]
1. an unpleasant cutaneous sensation that provokes the desire to rub or scratch the skin to obtain relief. Called also itching.
2. any of various conditions marked by this sensation, the specific site or type being indicated by a modifying term. See also
intense chronic itching in the anal region.
pruritus and other skin sensations, such as burning, lasting for 30 minutes to two hours, after contact with water, without
the overt skin changes seen in aquagenic urticaria. The etiology is usually unknown, although it is sometimes seen accompanying
polycythemia vera and in other cases it may be familial. A similar condition is seen in elderly women but lasts only 10 to
20 minutes and is relieved by emollients.
intense itching in the scrotal area.
, p. seni´lis
an itching in the aged, possibly due to dryness of the skin occurring as a result of decreased sweat and sebum secretion,
or bathing too frequently, or both.
generalized itching associated with chronic renal failure and not attributable to other internal or skin disease.
intense itching of the external genitals of the female, as in lichen sclerosus.
Stanley B., born 1942. American neurologist; winner of the Nobel prize for medicine or physiology in 1997 for his discovery
Prussak's fibers, pouch, space (Prus·sak's fibers, pouch, space)
[Alexander Prussak, Russian otologist, 18391897]
see under fiber, and see recessus superior membranae tympanicae.
prussic acid (prus·sic ac·id)
phosphatidylserine; pulmonary stenosis.
pertaining to the psalterium.
[L., from Gr. psaltērion harp]
1. commissura fornicis.
2. the omasum.
a genus of blister beetles (family Meloidae). P. fus´ca and P. substriga´ta of Africa produce a severe vesicular dermatitis.
[Gr. psammos sand]
a combining form meaning sandlike or denoting relationship to sand.
[psammo- + carcinoma]
carcinoma containing calcareous matter.
[psamm- + -oma]
1. any tumor that contains psammoma bodies.
2. psammomatous meningioma.
characterized by the presence of or containing psammoma bodies.