(a.) Acting; -- opposed to patient, or sustaining, action.
(n.) One who exerts power, or has the power to act; an actor.
(n.) One who acts for, or in the place of, another, by authority from him; one intrusted with the business of another; a substitute; a deputy; a factor.
(n.) An active power or cause; that which has the power to produce an effect; as, a physical, chemical, or medicinal agent; as, heat is a powerful agent.
Example Sentences:
(1) Combinations of maximum amounts of glucagon and the cyclic nucleotide did not produce a greater effect than either agent alone.
(2) Assessment of the likelihood of replication in humans has included in vitro exposure of human cells to the potential pesticidal agent.
(3) In addition, intravenous injection of complexes into rabbits showed optimal myocardial images with agents of intermediate lipophilicity.
(4) This study examined the [3H]5-HT-releasing properties of 3,4-methylenedioxymethamphetamine (MDMA) and related agents, all of which cause significant release of [3H]5-HT from rat brain synaptosomes.
(5) The quaternary structure of ribonucleotide reductase of Escherichia coli was investigated, with the use of purified B1 and B2 proteins and bifunctional cross-linking agents.
(6) Rapid overgrowth of all cultures with the E. coli necessitated the use of selective media containing antimicrobial agents to which the E. coli was sensitive.
(7) These membrane perturbation effects not observed with bleomycin-iron in the presence of a hydroxyl radical scavenger, dimethyl thiourea, or a chelating agent, desferrioxamine, were correlated with the ability of the complex to generate highly reactive oxygen species.
(8) of PLA2 caused marked degranulation of mast cells in the rat mesentery which was facilitated by addition of calcium ion (10 mM) but antagonized by pretreating with three antiinflammatory agents.
(9) We report a series of experiments designed to determine if agents and conditions that have been reported to alter sodium reabsorption, Na-K-ATPase activity or cellular structure in the rat distal nephron might also regulate the density or affinity of binding of 3H-metolazone to the putative thiazide receptor in the distal nephron.
(10) Acquired drug resistance to INH, RMP, and EMB can be demonstrated in M. kansasii, and SMX in combination with other agents chosen on the basis of MIC determinations are effective in the treatment of disease caused by RMP-resistant M. kansasii.
(11) The secondary leukemia that occurred in these patients could be distinguished from the secondary leukemia that occurs after treatment with alkylating agents by the following: a shorter latency period; a predominance of monocytic or myelomonocytic features; and frequent cytogenetic abnormalities involving 11q23.
(12) The agent present in the serum which causes dissolution of the fibrin clot was isolated and identified as pepsinogen.
(13) The active agents modestly improved treadmill exercise duration time until 1 mm ST segment depression (3%), and only propranolol and diltiazem had significant effects.
(14) Maximal covalent binding of [4,5-14C]ronidazole to DNA also required four-electron reduction, consistent with previous studies of the covalent binding of this agent to immobilized sulfhydryl groups [Kedderis et al.
(15) Since interferon alfa-2b (Intron A) is useful as a single agent, it is important to determine if interferon can be combined with standard chemotherapy to improve both response and survival in patients with cancer.
(16) Median effect analysis was applied for the evaluation of in vitro effect by the growth inhibition, and the in vivo effect by comparison of the increase of life span (ILS) in a combined group with the sum of ILS's in 2 single agent groups.
(17) Noradrenaline (NA) was released from sympathetic nerve endings in the tissue by electrical stimulation of the mesenteric nerves or by the indirect sympathomimetic agent tyramine.
(18) Helsby, who joined the estate agent in 1980, saw his basic salary unchanged at £225,000, but gains a £610,000 windfall in shares, available from May, as well as a £363,000 increase in cash and shares under the company profits-sharing scheme.
(19) Combining maximally effective concentrations of each of these stimulating agents produces an additive increase in both the level of 32P incorporation into tyrosine hydroxylase and the degree of activation of the enzyme.
(20) The review provides an update of drug-induced pulmonary disorders, focusing on newer agents whose effects on the lung have been studied recently.
Principal
Definition:
(a.) Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a state; the principal productions of a country; the principal arguments in a case.
(a.) Of or pertaining to a prince; princely.
(n.) A leader, chief, or head; one who takes the lead; one who acts independently, or who has controlling authority or influence; as, the principal of a faction, a school, a firm, etc.; -- distinguished from a subordinate, abettor, auxiliary, or assistant.
(n.) The chief actor in a crime, or an abettor who is present at it, -- as distinguished from an accessory.
(n.) A chief obligor, promisor, or debtor, -- as distinguished from a surety.
(n.) One who employs another to act for him, -- as distinguished from an agent.
(n.) A thing of chief or prime importance; something fundamental or especially conspicuous.
(n.) A capital sum of money, placed out at interest, due as a debt or used as a fund; -- so called in distinction from interest or profit.
(n.) The construction which gives shape and strength to a roof, -- generally a truss of timber or iron, but there are roofs with stone principals. Also, loosely, the most important member of a piece of framing.
(n.) In English organs the chief open metallic stop, an octave above the open diapason. On the manual it is four feet long, on the pedal eight feet. In Germany this term corresponds to the English open diapason.
(n.) A heirloom; a mortuary.
(n.) The first two long feathers of a hawk's wing.
(n.) One of turrets or pinnacles of waxwork and tapers with which the posts and center of a funeral hearse were formerly crowned.
(n.) A principal or essential point or rule; a principle.
Example Sentences:
(1) In addition to their involvement in thrombosis, activated platelets release growth factors, most notably a platelet-derived growth factor (PDGF) which may be the principal mediator of smooth muscle cell migration from the media into the intima and of smooth muscle cell proliferation in the intima as well as of vasoconstriction.
(2) While stereology is the principal technique, particularly in its application to the parenchyma, other compartments such as the airways and vasculature demand modifications or different methods altogether.
(3) Chromatography and immunoassays are the two principal techniques used in research and clinical laboratories for the measurement of drug concentrations in biological fluids.
(4) This paper reports, principally, the caries results of the first three surveys of 5, 12 and 5-year-olds undertaken at the end of 1987, 1988 and 1989, respectively.
(5) Rigidly fixing the pubic symphysis stiffened the model and resulted in principal stress patterns that did not reflect trabecular density or orientations as well as those of the deformable pubic symphysis model.
(6) The binding parameters indicate that the principal activating effect of UMP is not simply to increase the affinity of the enzyme for glucose.
(7) Mononuclear phagocytic cells from patients with either principal form of leprosy functioned similarly to normal monocytes in phagocytosis while their fungicidal activity for C. pseudotropicalis was statistically significantly altered and was more evident in the lepromatous than in the tuberculoid type.
(8) In the terminal segment of the hamster epididymidis there was some evidence of micro-merocrine protein secretion a the level of the principal cells and clear evidence of granular secretion in the light cells, presumable of glycoproteins.
(9) In the analysis of background fluorescence, the principal components were, as for the two-step technique, autofluorescence and propidium spectral overlap.
(10) However, at Period B, neutrophil numbers in the BAL fluid were increased in the principal but not in the control animals.
(11) Principal conclusions are: 1) rapid change to predominantly heterosexual HIV transmission can occur in North America, with serious societal impact; 2) gender-specific clinical features can lead to earlier diagnosis of HIV infection in women; 3) HIV infection in women does not pursue an inherently more rapid course than that observed in men.
(12) The concentrations of the principal extratesticular androgens and estradiol do not seem to have a quantitative influence on these androphilic proteins either.
(13) A principal function of GPIb is its attachment to von Willebrand Factor (vWF) on injured blood vessels which leads to the adhesion of platelets to these vessels.
(14) The principal variables influencing a particular configuration and their effects are indicated.
(15) The principal form of HMTs produced by these human peripheral blood monocytes has been subjected to biochemical, functional, and serological characterization.
(16) Micronutrient antioxidants such as alpha-tocopherol, the principal lipid-soluble antioxidant, assume potential significance because levels can be manipulated by dietary measures without resulting in side effects.
(17) Cytochrome oxidase histochemistry revealed patchy patterns of the enzyme activity in transverse sections through the caudal part of the ventral subnucleus of the principal sensory trigeminal nucleus, interpolar spinal trigeminal nucleus, and layer IV of the caudal spinal trigeminal nucleus in the cat.
(18) 3. an up-to-date review of the principal methods and systems used to measure the sedimentation rate--Automation of the Westergren initial methodology.
(19) • Queen Margaret Union, one of the University of Glasgow's two student unions, says 200 students there are marching on the principal's office at the moment to present an anti-cuts petition.
(20) This observation provides corroboration for the identification of the principal CCK-I neuron in the rat olfactory bulb as the centrally projecting middle tufted cell.