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Medical Dictionary


SYN: endopeptidase.

protein hydrolysate
A sterile solution of amino acids and soft-chain peptides prepared from a suitable protein by acid or enzymatic hydrolysis; used intravenously for the maintenance of positive nitrogen balance in severe illness, and after surgery involving the alimentary tract; or used orally in the diets of infants allergic to milk or as a supplement when high protein intake from ordinary foods cannot be accomplished.

proteinogenic (pro′ten-o-jen′ik)
SYN: proteogenic.

proteinoids (pro′ten-oydz; pro′te-in-oyds)
Artificially synthesized heteropoly(amino acids).

proteinosis (pro-te-no′sis, pro′te-i-no′sis)
A state characterized by disordered protein formation and distribution, particularly as manifested by the deposition of abnormal proteins in tissues. [protein + G. -osis, condition] lipoid p. [MIM*247100] a disturbance of lipid metabolism in which there are deposits of a protein-lipid complex on the tongue and sublingual and faucial areas leading to hoarseness, and translucent keratotic papillomatous eyelid lesions; autosomal recessive inheritance, frequently with specific intracranial calcifications. SYN: hyalinosis cutis et mucosae, lipoidosis cutis et mucosae, Urbach-Wiethe disease. pulmonary alveolar p. a chronic progressive lung disease of adults, characterized by alveolar accumulation of granular proteinaceous material that is PAS-positive and lipid- rich, with little inflammatory cellular exudate; the cause is unknown.

proteinuria (pro-te-noo′re-a, pro′te-i-noo′re-a)
1. Presence of urinary protein in amounts greater than 0.3 g in a 24-hour urine collection or in concentrations greater than 1 g/L (1+ to 2+ by standard turbidometric methods) in a random urine collection on two or more occasions at least 6 hours apart; specimens must be clean, voided midstream, or obtained by catheterization. 2. SYN: albuminuria. [protein + G. ouron, urine] Bence Jones p. presence of Bence Jones proteins in the urine, usually indicative of a neoplastic process such as multiple myeloma, amyloidosis, or Waldenström macroglobulinemia. gestational p. the presence of p. during or under the influence of pregnancy in the absence of hypertension, edema, renal infection, or known intrinsic renovascular disease. isolated p. p. in a patient who is asymptomatic, has normal renal function and urinary sediment, and has no manifestation of systemic disease upon initial examination. nonisolated p. p. associated with other abnormalities. orthostatic p., postural p. SYN: orthostatic albuminuria.

protensity (pro-ten′si-te)
The time attribute of a mental process; the attribute of a mental process characterized by its temporality or movement forward in time. [L. protendo (-tensum), to extend]

proteo-, prot-

proteoclastic (pro′te-o-klas′tik)
SYN: proteolytic. [proteo- + G. klastos, broken]

proteogenic (pro′te-o-jen-ik)
Capable of producing proteins. SYN: proteinogenic.

proteoglycan I
SYN: biglycan.

proteoglycans (pro′te-o-gli′kanz)
Glycoaminoglycans (mucopolysaccharides) bound to protein chains in covalent complexes; occur in the extracellular matrix of connective tissue.

proteohormone (pro′te-o-hor′mon)
Obsolete term for a hormone possessing a protein structure.

proteolipids (pro′te-o-lip′idz)
A class of lipid-soluble proteins found in brain tissue, insoluble in water but soluble in chloroform-methanol-water mixtures.

proteolysis (pro-te-ol′i-sis)
The decomposition of protein; primarily via the hydrolysis of peptide bonds, both enzymatically and nonenzymatically. [proteo- + G. lysis, dissolution]

proteolytic (pro′te-o-lit′ik)
Relating to or effecting proteolysis. SYN: proteoclastic.

proteometabolic (pro′te-o-met′a-bol′ik)
Relating to the metabolism of proteins.

proteometabolism (pro′te-o-me-tab′o-lizm)
SYN: protein metabolism.

Proteomyxidia (pro′te-o-mik-sid′e-a)
Former name for Eumycetozoea. [Proteus + G. myxa, mucus]

proteopectic, proteopexic (pro′te-o-pek′tik, -pek′sik)
Relating to proteopexis.

proteopepsis (pro′te-o-pep′sis)
The digestion of protein. [proteo- + G. pepsis, digestion]

proteopexis (pro′te-o-pek′sis)
The fixation of protein in the tissues. [proteo- + G. pexis, fixation]

proteose (pro′te-os)
A nondescript mixture of intermediate products of proteolysis between protein and peptone. primary p. the first result of hydrolysis of metaprotein; two stages, protoproteose and heteroproteose, have been distinguished. secondary p. p. derived from primary p. by further hydrolysis.

proteosome (pro′te-o-som)
A cluster of genes that encode components of the cell cytosolic proteolytic complex, a set of proteins thought to be involved in cellular processing and transport of peptides in the formation of the major histocompatibility complex class I molecules. [proteo- + G. soma, body]

Proteus (pro′te-us)
1. A former genus of the Sarcodina, now termed Amoeba. 2. A genus of motile, peritrichous, nonsporeforming, aerobic to facultatively anaerobic bacteria (family Enterobacteriaceae) containing Gram-negative rods; coccoid forms, large irregular involution forms, filaments, and spheroplasts occur under certain conditions. The metabolism is fermentative, producing acid or acid and visible gas from glucose; lactose is not fermented, and they rapidly decompose urea and deaminate phenylalanine. P. occurs primarily in fecal matter and in putrefying materials. The type species is P. vulgaris. [G. P., a sea god, who had the power to change his form] P. inconstans a bacterial species found in urinary tract infections and in sporadic cases of diarrhea in humans; some strains cause gastroenteritis. P. mirabilis a bacterial species found in putrid meat, infusions, and abscesses; a cause of urinary tract infections associated with formation of renal and bladder calculi. P. morganii former name for Morganella morganii, a bacterial species found in the intestinal canal, and in nosocomial infections. P. rettgeri SYN: Providencia rettgeri. P. vulgaris the type species of the bacterial genus P., found in putrefying materials and in abscesses; it is pathogenic for fish, dogs, guinea pigs, and mice; certain strains, the X strains of Weil and Felix, are agglutinated by typhus serum and are therefore of great importance in the diagnosis of typhus; strain X-19 is strongly agglutinated. SEE ALSO: Weil-Felix reaction.

prothipendyl (pro-thi′pen-dil)
An antipsychotic.

prothrombase (pro-throm′bas)
See factor X.

prothrombin (pro-throm′bin)
A glycoprotein, molecular weight approximately 72,500, formed and stored in the parenchymal cells of the liver and present in blood in a concentration of approximately 20 mg/100 mL. In the presence of thromboplastin and calcium ion, p. is converted to thrombin, which in turn converts fibrinogen to fibrin, this process resulting in coagulation of blood; a deficiency of p. leads to impaired blood coagulation. SYN: serozyme, thrombinogen, thrombogen.

prothrombinase (pro-throm′bi-nas)
SYN: factor X.

prothrombinogen (pro-throm′bi-no-jen)
SYN: factor VII.

prothrombinopenia (pro-throm′bi-no-pe′ne-a)
SYN: hypoprothrombinemia.

prothrombokinase (pro′throm-bo-ki′nas)
SYN: factor V, factor VIII.

protirelin (pro-ti′re-lin)
A synthetic form of thyroliberin.

protist (pro′tist)
A member of the kingdom Protista.

Protista (pro-tis′ta)
A kingdom of both plantlike and animallike eucaryotic unicellular organisms, either in the form of solitary organisms, e.g., protozoa, or colonies of cells lacking true tissues. [G. ntr. pl. of protistos, the first of all]

protium (pro′te-um)
SYN: hydrogen-1.

proto-, prot-
The first in a series; the highest in rank. [G. protos, first]

protoactinium (pro′to-ak-tin′e-um)
SYN: protactinium.

protoalbumose (pro-to-al′bu-mos)
SYN: protalbumose.

protoalkaloid (pro-to-al′ka-loyd)
A biogenic amine serving as a precursor of an alkaloid.

protobiology (pro′to-bi-ol′o-je)
SYN: bacteriophagology.

protocatechuic acid (pro′to-kat′e-choo′ik, -koo′ik)
Oxidation product of epinephrine.

protocol (pro′to-kol)
A precise and detailed plan for the study of a biomedical problem or for a regimen of therapy. Bruce p. a method of graduated, increasingly strenuous exercise testing to determine the severity of coronary artery disease. Bruce p. a standardized p. for electrocardiogram-monitored exercise using increasing speeds and elevations of the treadmill; a test for ischemia usually due to coronary artery disease. SEE ALSO: stress test.

protocone (pro′to-kon)
The mesiolingual cusp of an upper molar tooth in a mammal. [proto- + G. konos, cone]

protoconid (pro-to-kon′id)
The mesiolingual cusp of a lower molar tooth in a mammal.

protocoproporphyria (pro′to-kop′ro-por-fir′e-a)
Enhanced fecal excretion of proto- and coproporphyrins. p. hereditaria SYN: variegate porphyria.

Protoctista (pro-tok-tis′ta)
A kingdom of eukaryotes incorporating the algae and the protozoans that comprise the presumed ancestral stocks of the fungi, plant, and animal kingdoms; they lack the developmental pattern stemming from a blastula, typical of animals, the pattern of embryo development typical of plants, and development from spores as in the fungi. Included in P. are the nucleated algae and seaweeds, the flagellated water molds, slime molds, and slime nets, and the protozoa; unicellular, colonial, and multicellular organisms are included, but the complex development of tissues and organs of plants and animals is absent. The term P. replaces the term Protista, which connotes single-celled or acellular organisms, whereas the basal pre-plant (Protophyta) and pre-animal (Protozoa) assemblages incorporated in P. include many multicellular forms, since multicellularity appears to have evolved independently a number of times within these primitive groups. [G. protos, the first, + ktizo, to establish]

protoderm (pro′to-derm)
The undifferentiated cells of very young embryos, from which the primary germ layers will evolve. [proto- + G. derma, skin]

protodiastolic (pro′to-di-a-stol′ik)
Early diastolic, relating to the beginning of cardiac diastole.

protoduodenum (pro′to-doo-o-de′num, -doo-od′e-num)
The first part of the duodenum, which extends from the gastroduodenal pylorus as far as the major duodenal papilla and develops from the caudal foregut of the embryo; it has no plicae circulares and is the seat of the duodenal glands.

protoerythrocyte (pro′to-e-rith′ro-sit)
A primitive erythroblast.

protofilament (pro-to-fil′a-ment)
Basic element of a contractile flagellar microtubule, approximately 5 nm thick. [proto- + L. filum, a thread]

protogen, protogen A (pro′to-jen)
SYN: lipoic acid.

protogonoplasm (pro-to-gon′o-plazm)
A differentiated mass of cytoplasm in a protozoan, which forms the substance of later developing reproductive bodies. [proto- + G. gonos, seed, + plasma, a thing formed]

protokylol hydrochloride (pro-to-ki′lol)
A derivative of isoproterenol with the selective β-receptor–stimulating activity of the parent compound; it is effective orally and is more stable in the body than isoproterenol; used as a bronchodilator in the treatment of bronchial asthma and status asthmaticus.

protoleukocyte (pro-to-loo′ko-sit)
A primitive leukocyte; a leukocyte of the bone marrow.

protolysate (pro-tol′i-sat)
Rarely used term for a protein hydrolysate.

protomer (pro′to-mer)
A structural subunit of a larger structure. Protomers may themselves consist of subunits. For example, tubulin, an αβ dimer, is the p. for microtubules. [G. protos, first, + -mer 1]

protomerite (pro-tom′e-rit, pro′to-mer′it)
The second segment (lacking a nucleus) of a septate gregarine, between the epimerite and the deutomerite; it becomes the anterior end of the gamont after it has broken free of its host cell, leaving the epimerite embedded (usually in the gut wall of an infected invertebrate). SYN: primerite. [proto- + G. meros, part]

protometrocyte (pro-to-me′tro-sit)
The ancestor cell of the protoleukocyte and protoerythrocyte, or of the cells of the leukocytic and erythrocytic series. [proto- + G. meter, mother, + kytos, cell]

proton (p) (pro′ton)
The positively charged unit of the nuclear mass; protons form part (or in hydrogen-1 the whole) of the nucleus of the atom around which the negative electrons revolve. [G. ntr. of protos, first]

protoneuron (pro-to-noor′on)
Hypothetical primitive neuron lacking polarization. [proto- + G. neuron, nerve]

protonymph (pro′to-nimf)
In mites, the second instar.

protooncogene (pro-to-on′ko-jen)
A gene conserved long on the evolutionary scale present in the normal human genome, that appears to have a role in normal cellular physiology and is often involved in regulation of normal cell growth or proliferation; as a result of somatic mutations, these genes may become oncogenic; products of proto-oncognes may have important roles in normal cellular differentiation.

protopathic (pro-to-path′ik)
Denoting a supposedly primitive set or system of peripheral sensory nerve fibers conducting a low order of pain and temperature sensibility that is poorly localized. Cf.:epicritic. [proto- + G. pathos, suffering]

protopectin (pro-to-pek′tin)
See pectin.

protopianoma (pro′to-pe-an-o′ma)
SYN: mother yaw.

protoplasm (pro′to-plazm)
1. Living matter, the substance of which animal and vegetable cells are formed. SEE ALSO: cytoplasm, nucleoplasm. 2. The total cell material, including cell organelles. Cf.:cytoplasm, cytosol, hyaloplasm. SYN: plasmogen. [proto- + G. plasma, thing formed] totipotential p. living matter with the least recognizable differentiation of structure but with the greatest potential, all cell organs being formable by it.

protoplasmatic, protoplasmic (pro′to-plaz-mat′ik, -plaz′mik)
Relating to protoplasm.

protoplasmolysis (pro′to-plaz-mol′i-sis)
SYN: plasmolysis.


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