(n.) A gastropod shell belonging to the family Cerithiidae; -- so called from its hornlike form.
(n.) A mineral of a brownish of cherry-red color, commonly massive. It is a hydrous silicate of cerium and allied metals.
Example Sentences:
(1) The most common device used in Japan is an alcohol detector tube, in which cerite particles coated with chromate are packed.
Cerote
Definition:
(n.) See Cerate.
Example Sentences:
(1) The peroxisomal oxidation of the long chain fatty acid palmitate (C16:0) and the very long chain fatty acids lignocerate (C24:0) and cerotate (C26:0) was studied in freshly prepared homogenates of cultured skin fibroblasts from control individuals and patients with peroxisomal disorders.
(2) In fibroblasts from patients with X-linked adrenoleukodystrophy the peroxisomal oxidation of lignocerate and cerotate is impaired, but not that of palmitate.
(3) In microsomes and peroxisomes similar apparent Km values for palmitic acid were found (15 microM and 22.8 microM, respectively), whereas apparent Km values for cerotic acid were 8.4 microM and 1.0 microM in microsomes and peroxisomes, respectively.
(4) We have investigated the palmitic acid (C16:0) and cerotic acid (C26:0) activating activities in rat-liver microsomes and peroxisomes.
(5) We have investigated the contribution of peroxisomes and mitochondria to the beta-oxidation of palmitate (C16:0) and cerotate (C26:0) in intact human skin fibroblasts.
(6) When 2-[5-(4-chlorophenyl)pentyl]-oxirane-2-carboxylate (POCA) was used to specifically block carnitine palmitoyltransferase I, it was found that palmitate beta-oxidation was inhibited almost completely whereas cerotate beta-oxidation was not affected.
(7) However, the dependency of the oxidation of palmitate on the concentration of the cofactors differs markedly from that of the oxidation of lignocerate and cerotate.
(8) In this paper we show that cultured chorionic villous fibroblasts efficiently catalyse the peroxisomal beta-oxidation of hexacosanoic acid (cerotic acid), a saturated very long chain fatty acid containing 26 carbon atoms.
(9) No deficiency of the crude mitochrondrial (pH 4.2), the microsomal (pH 6.0), or the myelin-localized cholesterol ester hydrolases was detected, although the activities of the myelin-localized cholesterol ester hydrolase against cholesteryl lignocerate and cerotate were too low for reliable assays.
(10) From the observation that P10 activation is not affected by palmitic acid and cerotic acid, we conclude that P10 is activated by a distinct enzyme.
(11) These results indicate that rat brain peroxisomes contribute only little (about 15%) to palmitic acid oxidation and provide conclusive evidence that cerotic acid is oxidized exclusively in rat brain peroxisomes.
(12) Competition experiments indicate that in fibroblasts, as in rat liver, distinct enzyme systems are responsible for the oxidation of palmitate on the one hand and lignocerate and cerotate on the other hand.
(13) Fractionation studies indicate that in rat liver activation of cerotate and lignocerate to cerotoyl-CoA and lignoceroyl-CoA, respectively, occurs in two subcellular fractions, the endoplasmic reticulum and the peroxisomes but not in the mitochondria.
(14) Neither did the distribution of the label among individual lipids reveal differences between the controls and adrenoleukodystrophy, although there were interesting and dramatic differences in the metabolism of lignoceric acid and cerotic acid.
(15) Cerotic acid appeared largely inert with 90--95% remaining intact over eight days, while lignoceric acid was mostly incorporated into complex lipids.
(16) The inhibition by P10 of palmitic acid activation and cerotic acid activation was non-competitive in both organelles.
(17) In cultured glial cells as well as in dissociated brain cells from adult rats palmitic acid (16:0) oxidation was inhibited by about 85% of control values when 25 microM POCA was added to the medium, whereas no inhibition of cerotic acid (26:0) oxidation was observed.
(18) Postmortem brain tissues from three patients were assayed for activities of the three distinct cholesterol ester hydrolases, using [4-14C]cholesterol oleate, lignocerate and cerotate as the substrates.
(19) Furthermore, omission of carnitine from the culture medium resulted in a 57.7% decrease in palmitic acid oxidation in cultured glial cells, whereas cerotic acid oxidation was not influenced.
(20) The activation of cerotic acid was found to be inhibited to a progressively greater extent by increasing concentrations of 1-pyrenedecanoic acid (P10) as compared to the activation of palmitic acid, both in microsomes and peroxisomes.