Search Results
Results 201 - 250 of 1214
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Sakamoto T - - 2000
BACKGROUND AND AIMS: Phospholipase D (PLD) hydrolyzes phosphatidylcholine and produces lipid second messengers. Although cellular PLD has recently been recognized as an important signal-transmitting enzyme, the role of PLD in pathophysiologic conditions is largely unknown. In particular, the regulation of PLD in intestinal inflammation has not been previously investigated. The ...
Miyashita M - - 2000
BACKGROUND/AIMS: Phospholipase A2 activity is reported to be related to the physiology of various disorders, and the activity is modified by deoxycholic acid. METHODOLOGY: Serum phospholipase A2 activity was measured by counting the radioactivity of 14C-palmitic acid released from L-3-phosphatidylcholine (1-palmitoyl-2-14C-palmitoyl) in 40 patients with hyperbilirubinemia due to malignant neoplasms ...
El Maghraby G M - - 2000
The aim of this study was to investigate the importance of liposome structure in oestradiol skin delivery as a tool for understanding the delivery mechanism from lipid vesicles. Liposomes of phosphatidylcholine (PC) (1), PC, sodium cholate; 86:14 w/w (II), PC, Span 80; 86.7:13.3 w/w (III) and PC, oleic acid: 84:16 ...
Nishiyama A - - 2000
The proliferation of concanavalin A (Con A)-stimulated rat lymphocytes was markedly inhibited by phosphatidylcholine containing arachidonic and stearic acids (PC(A-S)), but not by phosphatidylcholine containing oleic and stearic acids or phosphatidylinositol containing arachidonic and stearic acids. The concentration of PC(A-S) which inhibited Con A-stimulated proliferation by 50% was 31 microM ...
Saini S S - - 2000
Synthetic melittin mediated the release of [3H]-oleic acid ([3H]-OA) or its acylated lipids from [3H]-OA-labeled E. coli cells exposed to human serum. This phenomenon was not observed in the absence of serum and was calcium independent. The addition of serum was not required for melittin-mediated lysis of erythrocytes, although lysis ...
Chang C Y - - 2000
The synthesis of inflammation mediators produced from arachidonic acid is regulated primarily by the cellular concentration of free arachidonic acid. Since intracellular arachidonic acid is almost totally present as phospholipid esters, the concentration of intracellular arachidonic acid is primarily dependent on the balance between the release of arachidonic acid from ...
Fuly A L - - 2000
An acidic phospholipase A2 isolated from Lachesis muta snake venom denoted LM-PLA2, showed neither toxic nor anticoagulant activities in contrast to a potent inhibitory effect of collagen-induced platelet aggregation [Fuly, A.L., Machado. O.L.T., Alves, E.W. and Carlini, C.R., 1997. Thromb. Haemost 78, 1372-1380.]. Now, the myotoxicity induced by LM-PLA2 was ...
Savitsky A A - - 2000
Covalently bound conjugates of alpha-fetoprotein (AFP) and epidermal growth factor (EGF) with photoheme (PH), 3-desvinyl-3-formylchlorine p6 (Chl p6), chlorine e6 (Chl e6), aluminum disulfochloride phthalocyanine (PC(Al)), and cobalt octa-4,5-carboxyphthalocyanine (teraphthal, TP(Co)) were synthesized. Their molar ratios were 1:4 for AFP-cytotoxin conjugates (cf. 1:10 for AFP-TP(Co)) and 1:2 for EGF conjugates ...
Narita K - - 2000
To better define a therapeutic time window for reducing the extent of damage in ischemic penumbra, the time courses of changes in the glycerophospholipid and free fatty acid (FFA) levels were determined in the rat cerebral cortex following induction of the permanent focal ischemia. Focal ischemia induced a biphasic increase ...
Morita Y S - - 2000
Glycosyl phosphatidylinositol (GPI) anchors in the bloodstream form of Trypanosoma brucei are unusual in that their two fatty acids are myristate. The myristates are added in the final stages of GPI biosynthesis in a remodeling reaction. Remodeling occurs first at the sn-2 position of glycerol, involving removal of a longer ...
Trotter P J - - 2000
Phosphatidic acid is a central intermediate of biosynthetic lipid metabolism as well as an important signaling molecule in the cell. These studies assess the internalization, or retrograde transport, and metabolism of phosphatidic acid in yeast using a fluorescent analog. An analog of phosphatidic acid fluorescently labeled at the sn-2 position ...
Sapirstein A - - 2000
Phospholipases A2 (PLA2s) regulate hydrolysis of fatty acids, including arachidonic acid, from the sn-2 position of phospholipid membranes. PLA2 activity has been implicated in neurotoxicity and neurodegenerative processes secondary to ischemia and reperfusion and other oxidative stresses. The PLA2s constitute a superfamily whose members have diverse functions and patterns of ...
Leondaritis G - - 2000
The unicellular eukaryote Tetrahymena is a popular model for the study of lipid metabolism. Less attention, however, has been given to the inositol phospholipids of the cell, although it is known that this class of lipids plays an important role in eukaryotic cell signaling. Tetrahymena pyriformis phosphatidylinositol was isolated, purified, ...
Ishikawa T - - 2000
Several isozymes of mammalian type 2, Mg(2+)-independent phosphatidic acid phosphatase (PAP-2) have recently been cloned, and they are predicted to have their catalytic sites exposed at the cell surface membranes. We investigated the mode of utilization of extracellular lipid substrates by the human PAP-2b expressed in HEK293 cells as a ...
Utzmann C M - - 2000
While the Maillard reaction of free amino acids and proteins is a well-established process, no defined structures from the nonenzymatic browning of aminophospholipids in foodstuffs have been described so far. Phosphatidylethanolamine (PE)-linked glucosylamines (Schiff-PE), Amadori products (Amadori-PE), 5-hydroxymethylpyrrole-2-carbaldehydes (Pyrrole-PE), and carboxymethyl (CM-PE) as well as carboxyethyl (CE-PE) derivatives were detected ...
Liu J J - - 2000
Digestion of dietary sphingomyelin (SM) is catalyzed by intestinal alkaline sphingomyelinase (SMase) and may have important implications in colonic tumorigenesis. Previous studies demonstrated that the digestion and absorption of dietary SM was slow and incomplete and that the colon was exposed to SM and its hydrolytic products including ceramide. In ...
Parks J S - - 2000
The purpose of this study was to test the hypothesis that lipid fluidity regulates lecithin:cholesterol acyltransferase (LCAT) activity. Phosphatidylcholine (PC) species were synthesized that varied in fluidity by changing the number, type (cis vs. trans), or position of the double bonds in 18 or 20 carbon sn-2 fatty acyl chains ...
Orlati S - - 2000
Sphingosine-1-phosphate (SPP) acts as a first messenger in immortalized human airway epithelial cells (CFNPE9o(-)), possibly interacting with an Edg family receptor. Expression of the SPP receptors Edg-1 and Edg-3, as well as a low level of Edg-5/H218, was detected in these cells, in agreement with their ability to specifically bind ...
Chauhan A - - 2000
Fibrillar amyloid beta-protein (Abeta) is the major protein of amyloid plaques in the brains of patients with Alzheimer's disease (AD). The mechanism by which normally produced soluble Abeta gets fibrillized in AD is not clear. We studied the effect of neutral, zwitterionic, and anionic lipids on the fibrillization of Abeta ...
Grossmann E M - - 2000
Eicosanoids are involved in gallbladder inflammation, epithelial water transport, and mucous secretion. Phospholipase Asubscript2 enzymes liberate arachidonic acid from membrane phospholipids for the synthesis of eicosanoids. The purpose of this study was to determine the effect of selective cytoplasmic and secretory phospholipase A2 inhibitors on basal and stimulated arachidonic acid ...
Mazereeuw-Hautier J - - 2000
Phospholipases A2 (PLA2) catalyse the release of fatty acids from the sn-2 position of phospholipids and have been suggested to play a key part in permeability barrier homeostasis. Using a sensitive and versatile fluorometric method, significant PLA2 activity has been detected in both human skin homogenates and tape strippings of ...
Mongrand S - - 2000
Plastids rely on the import of extraplastidial precursor for the synthesis of their own lipids. This key phenomenon in the formation of plastidial phosphatidylcholine (PC) and of the most abundant lipids on earth, namely galactolipids, is poorly understood. Various suggestions have been made on the nature of the precursor molecule(s) ...
Florin-Christensen J - - 2000
This work examines the lipid composition and metabolism of bovine red blood cells infected by apicomplexan Babesia parasites, organisms closely related to Plasmodium sp. We found that erythrocytes infected with Babesia bovis (i-RBC) accumulate lipids and show striking increases in phosphatidylcholine, phosphatidic acid, diacylglycerol and cholesteryl esters as compared to ...
Baker R R - - 2000
Neuronal nuclei isolated from rabbit cerebral cortex were found to be enriched in an NEM-insensitive lysophosphatidic acid (lysoPA) phosphohydrolase activity. LysoPA is an inhibitor of the nuclear lysophosphatidylcholine (lysoPC) lysophospholipase, and by preserving lysoPC levels, lysoPA boosted the nuclear production of the acyl analogue of platelet-activating factor by promoting the ...
Haftendorn R - - 2000
A series of 1,3-diacylglycero-2-phosphocholines (1,3-PCs) with acyl chain lengths of C8-C18 were synthesised by chemical introduction of the phosphocholine moiety into the regioisomerically pure 1,3-diacylglycerols, which were obtained from glycerol and the vinyl esters of fatty acid by means of lipase from Rhizomucor mihei. The 1,3-PCs being regioisomers of the ...
Kashiwagi T - - 2000
Retinal lipids of crayfish, kept at 4 degrees C under continuous darkness for 3 weeks, consisted mainly of phosphatidylcholine (PC) and phosphatidylethanolamine (PE); sphingomyelin (SM), phosphatidylinositol (PI) and phosphatidylserine (PS) were minor contributors. PI, involved in the phototransduction cascade, never reached greater concentrations than 7% of the total. High concentrations ...
Bertello L E - - 2000
The lipid moiety in the glycosylphosphatidylinositol anchors of glycoproteins of Trypanosoma cruzi consists of an alkylacylglycerol, a lysoalkylglycerol or a ceramide. Previously, we showed that the inositolphosphoceramides (IPCs) are the major components in the precursor inositolphospholipids of epimastigote and trypomastigote forms. Using (3)H-labelled subfractions of IPC, phosphatidylinositol (PI) and glycoinositolphospholipids ...
Florin-Christensen J - - 1999
Phospholipases A(1) and A(2) frequently coexist in biological systems. Generation of lysophosphatidylcholine (LPC) in such systems cannot be assigned to any of these types of enzymes unless the position of the fatty acid in the lysocompound can be unambiguously determined. We here present a simple method to achieve this purpose. ...
Kitsiouli E I - - 1999
The purpose of the present study was the development and evaluation of a fluorimetric method for the screening and differential determination of phospholipase A(2) and PAF-acetylhydrolase in bronchoalveolar lavage (BAL) fluid and serum. Phospholipase A(2) was determined using C(12)-NBD-PC in the presence of Ca(2+), from the slope of the fluorescence ...
Fortes-Dias C L - - 1999
A phospholipase A2 inhibitor has been previously purified and cloned from the blood plasma of the South American rattlesnake, Crotalus durissus terrificus. This inhibitor, named CNF for Crotalus neutralizing factor, interacts with crotoxin, the main neurotoxin from C. d. terrificus venom, abolishing its phospholipase A2 activity. Crotoxin is a heterodimer ...
Lee J Y - - 1999
Brain glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD)-catalyzed conversion of amphiphilic form of Zn2+ -glycerophosphocholine cholinephosphodiesterase (Amp-GPC PDE) into hydrophilic form was investigated in the presence of natural amphiphiles. Monoacylglycerols enhanced considerably the conversion by GPI-PLD of Amp-GPC PDE to hydrophilic form, with the enhancing effect of monoacylglycerols being dependent on the size ...
Rao A M - - 1999
CDP-choline is a rate-limiting intermediate in the biosynthesis of phosphatidylcholine (PtdCho), an important component of the neural cell membrane. The ability of CDP-choline to alter phospholipid metabolism is an important function in the treatment of ischemic injury. Exogenous treatment with CDP-choline stimulates PtdCho synthesis and prevents release of free fatty ...
Pagès C - - 1999
In the present study, we studied the involvement of A2 phospholipases (PLA2) in alpha2-adrenergic receptor-control of preadipocyte actin cytoskeleton. For that, various PLA2 inhibitors were tested on the ability of the selective alpha2-adrenergic agonist UK14304 to induce the spreading in alpha2AF2 preadipocytes. We observed that, whereas several Ca(2+)-dependent PLA2 blockers ...
Sciorra V A - - 1999
Phosphatidylcholine (PC) is a major source of lipid-derived second messenger molecules that function as both intracellular and extracellular signals. PC-specific phospholipase D (PLD) and phosphatidic acid phosphohydrolase (PAP) are two pivotal enzymes in this signaling system, and they act in series to generate the biologically active lipids phosphatidic acid (PA) ...
Chakraborty T R - - 1999
The topography of formation and migration of phosphatidic acid (PA) in the transverse plane of rat liver mitochondrial outer membrane (MOM) were investigated. Isolated mitochondria and microsomes, incubated with sn-glycerol 3-phosphate and an immobilized substrate palmitoyl-CoA-agarose, synthesized both lyso-PA and PA. The mitochondrial and microsomal acylation of glycerophosphate with palmitoyl-CoA-agarose ...
Merkel O - - 1999
The yeast genome contains two genes, designated as PLB2 and PLB3, that are 67% and 62% identical, respectively, to PLB1, which codes for a phospholipase B/lysophospholipase in yeast (Lee, S. K., Patton, J. L., Fido, M., Hines, L. K., Kohlwein, S. D., Paltauf, F., Henry, S. A., and Levin, D. ...
Yin J J - - 1999
The effect of conjugated linoleic acid (CLA) on the relation between structure and function of membranes is described in this paper. Electron spin resonance (ESR) spin-label oximetry was used in the present study to evaluate if oxygen transport and oxygen depletion were affected by incorporation of CLA instead of linoleic ...
Ahn T - - 1999
The mixing properties of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were examined in liquid-crystalline phase using fluorescent probes incorporated into lipid bilayers. The excimer to monomer (E/M) fluorescence ratio of 1-hexadecanoyl-2-(1-pyrenedecanoyl)-sn-glycero-3-phosphocholine (PPC) versus PPC concentration was higher for binary mixtures containing phosphatidylcholine (PC)/phosphatidylethanolamine (PE) (1:1) compared to PC matrix. When POPC ...
Khozin-Goldberg I - - 1999
Treatment of the microalga Porphyridium cruentum with salicylhydroxamic acid (SHAM) inhibited growth and affected fatty acid composition. At a relatively low concentration (40 microM) SHAM predominantly inhibits Delta6 desaturation. The effect of the inhibitor was most intense in phosphatidylcholine (PC) and phosphatidylethanolamine, in which the proportions of the downstream products ...
Ho C L - - 1999
The yellow-legged hornet, Vespa verutina, is widely distributed in both the mountain area and the suburbs of Taiwan and possesses highly toxic venom (LD50=0.02 microl/g mouse). By gel filtration on Fractogel (TSK HW 50f) followed by cation-exchange chromatography on Mono S column, three toxins designated as verutoxin 1, 2a and ...
Martini W Z - - 1999
The primary goal of this study was to determine the contributions of plasma free fatty acids (FFA) and de novo synthesized fatty acids (FA) to lung surfactant phosphatidylcholine (PC) synthesis. A new stable isotope tracer model was developed in which [1, 2-(13)C(2)]acetate and uniformly labeled [U-(13)C(16)]palmitate were infused in nine ...
Jones D R - - 1999
Phosphatidic acid generation through activation of diacylglycerol kinase alpha has been implicated in interleukin-2-dependent T-lymphocyte proliferation. To investigate this lipid signaling in more detail, we characterized the molecular structures of the diradylglycerols and phosphatidic acids in the murine CTLL-2 T-cell line under both basal and stimulated conditions. In resting cells, ...
Mashima R - - 1999
We have previously isolated two proteins which can reduce phosphatidylcholine hydroperoxide (PC-OOH) from human blood plasma and identified one of the proteins as apolipoprotein A-I (Mashima, R. , et al. (1998) J. Lipid Res. 39, 1133-1140). In the present study we have identified the other protein as apolipoprotein B-100 (apo ...
Baker R R - - 1999
Neuronal nuclei were isolated from immature rabbit cerebral cortex and nuclear lysophospholipase activities studied using two different 1-acyl lysophospholipids: lysophosphatidylcholine (lysoPC) and lysophosphatidic acid (lysoPA). Our interest in these two lysolipids arose from the observation that lysoPA could promote the acetylation of lysoPC by substantially inhibiting a very active nuclear ...
Bogdanov M - - 1999
Escherichia coli-derived phosphatidylethanolamine (PE) or PE with fully saturated fatty acids was able to correct in vitro a defect in folding in the lipid-dependent epitope 4B1 of lactose permease (LacY) resulting from in vivo assembly in the absence of PE. PE plasmalogen, PE with two unsaturated fatty acids, and lyso-PE, ...
Liu X - - 1999
A cDNA encoding a basic-acidic hybrid phospholipase A2-II from Agkistrodon halys Pallas with an N-terminus highly homologous to that of BPLA2 and a C-terminus sequence almost the same as that of APLA2 was inserted into a bacterial expression vector and effectively expressed in Escherichia coli RR1. The protein was produced ...
Knapp S - - 1999
Cytidine and choline, present in cytidine 5'-diphosphate choline (CDP-choline), are major precursors of the phosphatidylcholine found in cell membranes and important regulatory elements in phosphatide biosynthesis. Administration of CDP-choline to rats increases blood and brain cytidine and choline levels; this enhances the production of endogenous CDP-choline which then combines with ...
Athenstaedt K - - 1999
In the yeast Saccharomyces cerevisiae lipid particles harbor two acyltransferases, Gat1p and Slc1p, which catalyze subsequent steps of acylation required for the formation of phosphatidic acid. Both enzymes are also components of the endoplasmic reticulum, but this compartment contains additional acyltransferase(s) involved in the biosynthesis of phosphatidic acid (K. Athenstaedt ...
Li J - - 1999
We previously showed indirectly that the increase in diacylglycerol (DAG) levels caused by exposing differentiating PC12 cells to nerve growth factor (NGF) must derive mainly from de novo synthesis and, to a lesser and transient extent, from the hydrolysis of [3H]phosphatidylinositol (PI). To explore further the biochemical mechanisms of this ...
Cogo P E - - 1999
Little is known about endogenous surfactant metabolism in infants, because radioactive isotopes used for this purpose in animals cannot be used in humans. We developed a novel and safe method to measure the endogenous surfactant kinetics in vivo in humans by using stable isotope labeled fatty acids. We infused albumin-bound ...
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