(n.) An alkaloid extracted from the bark of several species of cinchona (esp. Cinchona Calisaya) as a bitter white crystalline substance, C20H24N2O2. Hence, by extension (Med.), any of the salts of this alkaloid, as the acetate, chloride, sulphate, etc., employed as a febrifuge or antiperiodic. Called also quinia, quinina, etc.
Example Sentences:
(1) The influence of the hexylsalicylic acid (2) on the pharmacokinetic of the quinine (1), was studied using rabbits.
(2) Concomitant with the inhibition of K+ and Na+ transport, quinine stimulates ATP hydrolysis by 57%.
(3) those that had entered the G1 phase) expressed an increased amount of Fc gamma RII and (b) blocking the entry of activated cells into the S phase (with the ion channel blocker quinine) did not affect the Fc gamma RII induction by LPS.
(4) It was found that DI rats responded less than LE rats on the progressive-ratio schedule and that DI rats suppressed drinking as much as LE rats at each concentration of quinine used on the drinking-suppression test.
(5) Microsomal metabolites were also isolated from quinine and quinidine incubations with rabbit or guinea pig liver fractions.
(6) A nearly complete blockade of channel current was observed at 100 nM quinine and above.
(7) Treatment may be delayed because the therapy recommended for severe or complicated disease, intravenous quinine dihydrochloride, is available only from the Centers for Disease Control.
(8) Cell proliferation was equally sensitive to quinine regardless of mitogen.
(9) The responses to quinine and mefloquine or halofantrine showed no correlation with each other.
(10) The CGRP-IR levels in the rostral (gustatory) part of the insular cortex were increased significantly by strongly aversive taste stimuli such as quinine hydrochloride and conditioned taste stimuli (NaCl and sucrose) which animals had been taught to avoid.
(11) Quinidine, the stereoisomer of quinine, had no effect on either cells from the patient or normal cells.
(12) Despite the presence in the region of an important resistance of Plasmodium falciparum to chloroquine (80% specimens), one can conclude to a satisfying susceptibility of this parasite to quinine, provided posology and divided doses are respected.
(13) The clinical application of the method for routine drug monitoring and for estimating the pharmacokinetics of quinine and quinidine in man are discussed.
(14) The resistance of Plasmodium falciparum, the cause of tertian malaria, to synthetic antimalarials, together with the resistance of the vector mosquitoes to insecticides, has resulted in a resurgence in the use of quinine and a search for new antimalarial agents.
(15) all infections were sensitive to quinine plus tetracycline.
(16) Quinine applied on the intracellular side of the membrane in micromolar concentrations chopped the unitary K+ currents into bursts of brief openings.
(17) This was shown by a dye exclusion test and by mitogen stimulation after exposure and removal of quinine from the medium.
(18) These are insensitive to quinine, suggesting that they are not caused by an intracellular Ca accumulation.
(19) The spread of chloroquine-resistant malaria has led to a resurgence of quinine in clinical use.
(n.) A crystalline substance, C6H4O2 (called also benzoketone), first obtained by the oxidation of quinic acid and regarded as a double ketone; also, by extension, any one of the series of which quinone proper is the type.
Example Sentences:
(1) The thiol-conjugating capacity of quinones may, however, be applied to reduce the tissue-damaging effects of stimulated neutrophils.
(2) The effect of dicoumarol on glucuronidation of 3-OH-benzo(a)pyrene (BP) appears to be due to inhibition of UDPglucuronosyltransferase (UDPGT) and not to an inhibited DT-diaphorase (NAD(P)H:quinone oxidoreductase); to date the only enzyme known to be inhibited by dicoumarol.
(3) The coupled dienone-phenol re-arrangement and keto-enol tautomerism of this quinone methide produce the observed 3,4-dihydroxybenzaldehyde.
(4) Moreover, it seems unlikely that quinones are involved directly (e.g.
(5) The second-order rate constants appear to be at least 3 orders of magnitude lower than the second-order constants for quenching of the fluorescent probes; this is taken as a clear indication that ubiquinone diffusion is not the rate-determining step in the quinone-enzyme interaction.
(6) 15 human tumour cell lines (lung, breast and colon) have been evaluated for their sensitivity to the quinone based anti-cancer drugs Mitomycin C, Porfiromycin, and EO9 (3-hydroxymethyl-5-aziridinyl-1-methyl-2-(IH-indole-4,7-dione)prop-beta- en-alpha-ol).
(7) These studies provide evidence that GHB exerts cytotoxicity specifically for cells that by their content of tyrosinase convert the phenol to the quinone.
(8) Comparison of these two activities for both the quinone and hydroquinone showed that the hydroquinone form had superior activities.
(9) Bis(alkylthio)quinones 4a-d and 5a-d, and corresponding hydroquinones 9b-d exhibited high activities both in vitro and in vivo.
(10) It seems that quinone pigments, especially 2-oxyjuglone, react with complex I faster than it follows from their approximate values of one-electron reduction potential calculated from their reactivities with flavocychrome b2 and adrenodoxin.
(11) Formation of catechol from quinone by cyst extracts was observed spectrophotometrically and chromatographically.
(12) The present studies were conducted to evaluate the relative effect of the parent chemical BHT and two of its major oxidative metabolites, 2,6-di-tert-butyl-4-hydroxymethylphenol (BHT-BzOH) and 2,6-di-tert-butyl-1,4-benzoquinone (BHT-quinone), on DMBA-induced rat mammary tumorigenesis and on the formation of rat mammary DMBA-DNA adducts in vivo.
(13) Quinones play a major role in allergic contact dermatitis caused by plants.
(14) The urushiol analogs 5-pentadecylresorcinol (PDR) and 3-heptadecylveratrole (HDV) which cannot form o-quinones were found to be ineffective sensitizers as well.
(15) Toxicity of quinone(di)imines to hepatocytes and CHO cells was not related to superoxide anion radical formation, and toxicity to CHO cells was not affected by exclusion of oxygen during exposure of the cells to the compounds.
(16) The activity of cytochrome P-450 reductase, which reduces quinones to hydroquinones in the estrogen redox cycle, was 6-fold higher in liver than in kidney of both control and estrogen-treated animals.
(17) The interaction of pyrroloquinoline quinone (PQQ) with amino groups was followed by measuring the capacity of adducts to reduce nitroblue tetrazolium (NBT).
(18) The menadione-induced quinone reductase was isolated from the cytoplasmic fraction of induced cells.
(19) Hepa 1c1c7 murine hepatoma cells are plated in 96-well microtiter plates, grown for 24 h, and exposed to inducing agents for another 24 h. The cells are then lysed and quinone reductase activity is assayed by the addition of a reaction mixture containing an NADPH-generating system, menadione (2-methyl-1,4-naphthoquinone), and MTT [3-(4,-5-dimethylthiazo-2-yl)-2,5-diphenyltetrazolium bromide].
(20) quinone complex (X) was chemically reduced (state [PIX-]; P is the reaction center bacteriochlorophyll dimer, I is the long wavelength bacteriopheophytin), and compares these with the fluorescence observed when all the traps are open (state [PIX]) and with the fluorescence observed when all the traps are closed (state [P+IX]).