Search Results
Results 151 - 200 of 1233
1 2 3 4 5 6 7 8 9 10 >
Murakami Makoto - - 2003
PURPOSE OF REVIEW: Inflammation is an integral feature of atherosclerosis, in which inflammatory processes contribute to the initiation, progression and rupture of lipid-rich atherosclerotic plaques. Recent studies have suggested the involvement of the proinflammatory secretory phospholipase A2 (sPLA2)-IIA in the development of atherosclerosis. This enzyme has been proposed to hydrolyze ...
Brockman Howard L - - 2003
Mammalian synaptic membranes appear to contain high proportions of specific, sn-1-stearoyl-2-docosahexaenoyl- and sn-1-stearoyl-2-arachidonoyl phosphoglycerides, but the structural significance of this is unclear. Here we used a standardized approach to compare the properties of homogeneous monolayers of the corresponding phosphatidylcholines, phosphatidylethanolamines, phosphatidylserines, and phosphatidic acids with those of control monolayers of ...
Hakkarainen Minna - - 2003
A solid-phase microextraction (SPME) method was developed to quantitatively determine the amount of 6-hydroxyhexanoic acid in aqueous solutions. The SPME method in combination with GC-MS was then applied to identify and quantify the low-molecular-mass compounds migrating from a new poly(vinyl chloride) (PVC) material, PVC/polycaprolactone-polycarbonate (PCL-PC) during ageing in water. It ...
Ekroos Kim - - 2003
The molecular composition of phosphatidylcholines (PCs) in total lipid extracts was characterized by a combination of multiple precursor ion scanning on a hybrid quadrupole time-of-flight mass spectrometer and MS3 fragmentation on an ion trap mass spectrometer. Precursor ion spectra for 50 acyl anion fragments of fatty acids (fatty acid scanning) ...
Salto Maria Laura - - 2003
Differentiation of Trypanosoma cruzi trypomastigotes to amastigotes inside myoblasts or in vitro, at low extracellular pH, in the presence of [(3)H]palmitic acid or [(3)H]inositol revealed differential labeling of inositolphosphoceramide and phosphatidylinositol, suggesting that a remodeling process takes place in both lipids. Using (3)H-labeled inositolphosphoceramide and phosphatidylinositol as substrates, we demonstrated ...
Mulder C - - 2003
Choline containing phospholipids are essential for the integrity of the'cell'membrane. Minor changes in the lysophosphatidylcholine (lyso-PC)/phosphatidylcholine (PC) ratio may lead to neuronal damage and cell loss. Several studies have shown protein and lipid oxidation in Alzheimer's disease (AD) affected brain regions. Amyloid-beta peptides may induce free-radical oxidative stress which normally ...
Adibhatla Rao Muralikrishna - - 2003
Neuroprotection by citicoline (CDP-choline) in transient cerebral ischemia has been demonstrated previously. Citicoline has undergone several Phase III clinical trials for stroke, and is being evaluated for treatment of Alzheimer's and Parkinson's diseases. Phospholipid degradation and generation of reactive oxygen species (ROS) are major factors causing neuronal injury in CNS ...
Lin Jianming - - 2003
The qualitative and quantitative aroma composition of heated aqueous dispersions of egg phosphatidylcholine (PC) and egg phosphatidylethanolamine (PE) were characterized by aroma extract dilution analysis and isotope dilution assay. On the basis of FD-factors and odor activity values, trans-4,5-epoxy-(E)-2-decenal was found to be the most potent odorant followed by (E,E)-2,4-decadienal, ...
Sato Norihiro - - 2003
The fatty acid distributions at the sn-1 and sn-2 positions in major chloroplast lipids of Chlorella kessleri 11h, monogalactosyl diacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG), were determined to show the coexistence of both C16 and C18 acids at the sn-2 position, i.e. of prokaryotic and eukaryotic types in these galactolipids. ...
Krasilnikova O A - - 2003
The role of calcium ions in the L-thyroxine-induced initiation of hydrolysis of phosphatidylinositol 4,5-bisphosphate (PtdInsP2) and also the course of releasing individual fractions of inositol phosphates and diacylglycerides (DAG) were studied in liver cells during early stages of the hormone effect. L-Thyroxine stimulated a rapid hydrolysis in hepatocytes of PtdInsP2 ...
Wenk Markus R MR Howard Hughes Medical Institute, Department of Cell Biology, Yale University School of Medicine, Boyer Center for Molecular Medicine, 295 Congress Avenue, New Haven, Connecticut 06511, USA. - - 2003
Phosphoinositides (phosphorylated derivatives of phosphatidylinositol, PI) are versatile intracellular signaling lipids whose occurrence in low concentrations complicates direct mass measurements. Here we present a sensitive method to detect, identify and quantify phosphatidylinositol phosphate (PIP) and phosphatidylinositol bisphosphate (PIP(2)) with different fatty acid compositions (phosphoinositide profiles) in total lipid extracts by ...
Jouhet Juliette - - 2003
In plants, phosphate deprivation is normally known to decrease the phospholipid content consistent with a mobilization of the phosphate reserve, and conversely to increase non-phosphorous membrane lipids such as digalactosyldiacylglycerol. We report here that unexpectedly, at an early stage of phosphate starvation, phosphatidylcholine (PC) increases transiently. We also show that ...
Arisz Steven A - - 2003
In response to various environmental stress conditions, plants rapidly form the intracellular lipid second messenger phosphatidic acid (PA). It can be generated by two independent signalling pathways via phospholipase D (PLD) and via phospholipase C (PLC) in combination with diacylglycerol kinase (DGK). In the green alga Chlamydomonas, the phospholipid substrates ...
Ichihara Ken'ichi - - 2003
In developing seeds of Perilla frutescens var. crispa, the triacylglycerol fraction was found to accumulate between 15 and 19 days after flowering. Of this, 65% of the total fatty acids was alpha-linolenic acid in the mature seeds, with the latter being esterified in comparable amounts at all positions (sn-1, 2 ...
Hsu Fong-Fu - - 2003
We applied low-energy collisionally activated dissociation (CAD) tandem quadrupole mass spectrometry to study the fragmentation pathways of the [M + H](+) and [M + Li](+) ions of phosphatidylcholine (PC), generated by electrospray ionization (ESI). It is revealed that the fragmentation pathways leading to loss of the polar head group and ...
Al-Saad Khalid A - - 2003
The utility of post-source decay (PSD) matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was investigated for the structural analysis of phosphatidylcholine (PC). PC did not produce detectable negative molecular ion from MALDI, but positive ions were observed as both [PC+H](+) and [PC+Na](+). The PSD spectra of the protonated PC species ...
Fang Xiang - - 2003
Epoxyeicosatrienoic acids (EETs) are readily incorporated into phospholipids of smooth muscle cells (SMC) and endothelial cells (EC). Incorporation of EETs into intact porcine coronary arteries potentiates EC-dependent relaxation, but not vasorelaxation induced by agents that act solely on SMC. To explore the potential mechanisms responsible for this difference, porcine coronary ...
Kooijman Edgar E - - 2003
The local generation of phosphatidic acid plays a key role in the regulation of intracellular membrane transport through mechanisms which are largely unknown. Phosphatidic acid may recruit and activate downstream effectors, or change the biophysical properties of the membrane and directly induce membrane bending and/or destabilization. To evaluate these possibilities, ...
Kubiak Robert J - - 2003
Studies of cellular signal transduction mechanisms involving receptor-mediated generation of inositol phosphates and phosphorylated phosphatidylinositols require easy access to these naturally occurring products. Although numerous synthetic methods have been developed during the past decade, most of these methods suffer from excessive length and lack of generality. In this work we ...
Sorger D - - 2003
Triacylglycerol (TAG) is the major storage component for fatty acids, and thus for energy, in eukaryotic cells. In this mini-review, we describe recent progress that has been made with the yeast Saccharomyces cerevisiae in understanding formation of TAG and its cell biological role. Formation of TAG involves the synthesis of ...
Nanjundan Meera - - 2003
The lung contains two distinct forms of phosphatidic acid phosphatase (PAP). PAP1 is a cytosolic enzyme that is activated through fatty acid-induced translocation to the endoplasmic reticulum, where it converts phosphatidic acid (PA) to diacylglycerol (DAG) for the biosynthesis of phospholipids and neutral lipids. PAP1 is Mg(2+) dependent and sulfhydryl ...
Sugiura Takayuki - - 2002
Lysophosphatidic acid is a multifunctional phospholipid mediator and elicits a variety of biological responses in vitro and in vivo. Evidence is accumulating that lysophosphatidic acid plays important physiological roles in diverse mammalian tissues and cells. In the present study, we first examined whether lysophosphatidic acid is present in human saliva. ...
Araseki Mina - - 2002
Synthesized PCs containing docosahexaenoic acid (DHA), arachidonic acid (AA), linoleic acid (LA), and palmitic acid (PA) at known positions in the glycerol moiety were oxidized in liposomes, bulk, and organic solvent. In bulk and organic solvent, the oxidative stability of PC decreased with increasing degrees of unsaturation. However, the degree ...
Hird Geoffrey S - - 2002
A novel carbohydrate-based phospholipid containing a phosphatidic acid head group, bis-(2,3-lauroyl)-1-methoxy-5-ribo-phosphatidic acid (DLRPA), was synthesized and characterized by 1H NMR, 13C NMR, and 31P NMR. This molecule is an analog of dilauroyl phosphatidic acid (DLPA). The T(m) of DLRPA decreases with increasing pH in a similar pattern to DLPA, as ...
Xu Fred Y - - 2003
We examined the effect of etomoxir treatment on de novo cardiolipin (CL) biosynthesis in H9c2 cardiac myoblast cells. Etomoxir treatment did not affect the activities of the CL biosynthetic and remodeling enzymes but caused a reduction in [1-14C]palmitic acid or [1-14C]oleic acid incorporation into CL. The mechanism was a decrease ...
Shen Ein-Yiao - - 2002
To investigate the basic mechanism of epileptogenecity in children, we undertook a study of application of penicillin (PC) to the brain of an animal model. Different doses of PC were injected into the hippocampus of Spraque-Dawley rats subjected to microdialysis to observe in vivo changes of excitatory amino acid (EAA) ...
Hunt Alan N - - 2002
Deuterated choline-d(9) labelling of IMR-32 cells enabled comparison of the molecular specificities of whole cell and endonuclear phosphatidylcholine synthesis after 96 h polyunsaturated fatty acid supplementation. Surprisingly, while cell phosphatidylcholine synthesis and remodelling reflected a pattern of polyunsaturated fatty acid accretion, the saturated endonuclear phosphatidylcholine pool was only transiently labelled ...
Poveda José A - - 2002
Purified Acetylcholine Receptor (AcChR) from Torpedo has been reconstituted at low (approximately 1:3500) and high (approximately 1:560) protein to phospholipid molar ratios into vesicles containing egg phosphatidylcholine, cholesterol, and different dimyristoyl phospholipids (dimyristoyl phosphatidylcholine, phosphatidylserine, phosphatidylglycerol and phosphatidic acid) as probes to explore the effects of the protein on phospholipid ...
Lin Jiann-Tsyh - - 2002
As part of a program to elucidate castor oil biosynthesis, we have identified 36 molecular species of PC and 35 molecular species of PE isolated from castor microsomes after incubations with [14C]-labeled FA. The six [14C]FA studied were ricinoleate, stearate, oleate, linoleate, linolenate, and palmitate, which were the only FA ...
Wang Xuemin - - 2002
Phospholipase D (PLD) is a family of diverse enzymes that are differentially regulated by Ca(2+), polyphosphoinositides, free fatty acids, G-proteins, N-acylethanolamines, and membrane lipid environments. Two new types of PLDs were identified in the past year: one is activated by oleic acid and the other requires no cation for activity. ...
Nigou Jérôme - - 2002
Recent studies have demonstrated that, during infection of macrophages by mycobacteria, phospholipids (PLs) are released from the mycobacterial cell wall within infected macrophages and transported out of this compartment into intracellular vesicles. The release of these PLs may have functions that influence the outcome of mycobacterial infections. Despite their important ...
Panasenko O M - - 2002
The interaction between unsaturated phosphatidylcholines and either exogenous or endogenous (produced by the enzyme system involving myeloperoxidase (MPO), H2O2, and Cl-) hypochlorite was studied in multilayer liposomes containing oleic, linoleic, and arachidonic acid residues using MALDI-TOF mass spectrometry. At pH 7.4, hypochlorite reacts with the double bond of the oleic ...
Laxalt Ana M - - 2002
Phospholipid-derived molecules are emerging as novel second messengers in plant defence signalling. Recent research has begun to reveal the signals produced by the enzymes phospholipase C, phospholipase D and phospholipase A2 and their putative downstream targets. These include the activation of a MAP kinase cascade and triggering of an oxidative ...
Pillai Manoj G - - 2002
The incorporation of radiolabeled lipid precursors into triacylglycerol (TG) molecular species in Mortierella ramanniana var. angulispora, an oleaginous fungus, was studied to determine the biosynthetic pathways for TG molecular species. Radiolabeled TG molecular species were separated and quantified by reverse-phase high performance liquid chromatography with a radioisotope detector. The major ...
Balsinde Jesús - - 2002
In the present study the lysophospholipid sources for arachidonic (AA) and eicosapentaenoic acid (EPA) incorporation into and redistribution within the phospholipids of phorbol-ester-differentiated U937 cells was investigated. Initially, AA incorporated primarily into choline glycerophospholipids (PC), whereas EPA incorporated mainly into ethanolamine glycerophospholipids (PE). Bromoenol lactone (BEL), an inhibitor of the ...
Lund Eric D - - 2002
Perkinsus marinus is a protozoan parasite that causes high mortality in its commercially and ecologically important host, the Eastern oyster Crassostrea virginica. In order to understand the host-parasite relationship in lipid metabolism, the ability of P. marinus to synthesize phospholipids from polar headgroup precursors was investigated. Pulse/chase experiments were conducted ...
Morales Rogelio - - 2002
The interfacial activation of porcine pancreatic phospholipase A(2) (PLA(2)) during the hydrolysis of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine liposomes at different temperatures has been monitored by fluorescence changes of the 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) lipid derivatives 1-palmitoyl-2-[6-[(7-nitro-2-1,3-benzoxadiazol-4-yl)amino]dodecanoyl]-sn-glycero-3-phosphocholine (C(12)-NBD-PC) and 12-[(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)]dodecanoic acid (C(12)-NBD-FA) inserted in the substrate vesicles. These long-chain monitors, in contrast to the previously used ...
Bigogno Chiara - - 2002
The fresh-water green alga Parietochloris incisa is the richest plant source of the PUFA arachidonic acid (20:4n-6, AA). To elucidate the biosynthesis of AA in this alga we labeled cultures of P. incisa with radioactive precursors. Pulse chase labeling with acetate resulted in its incorporation via the de novo biosynthesis ...
Lindberg Jan - - 2002
New efficient routes to enantiopure phospholipids, starting from (S)-glycidol, are described. Lysophosphatidic acids and phosphatidic acids were obtained in good overall yields from (S)-glycidol, in only three and four steps, respectively. Moreover, the strategy can also be used to produce phosphatidylcholines in three steps. Using dialkylphosphoramidites, (S)-glycidol was phosphorylated to ...
Hoffman D R - - 2001
BACKGROUND: With the increase in commercial vegetable production in greenhouses, occupational sensitization to bumblebee venom is becoming more common. Studies using sera from subjects thus sensitized allow evaluation of the allergenic specificity of bumblebee sensitization. OBJECTIVE: The purposes of this study were to determine the degree of species group specificity ...
Wang C - - 2001
Oleate-dependent phospholipase D (PLD; EC 3.1.4.4) has been reported in animal systems, but its molecular nature is unkown. Multiple PLDs have been characterized in plants, but none of the previously cloned PLDs exhibits the oleate-activated activity. Here, we describe the biochemical and molecular identification and characterization of an oleate-activated PLD ...
Wongkajornsilp A - - 2001
The somatic genetic defect in paroxysmal nocturnal haemoglobinuria (PNH) involves a block in the transfer of GlcNAc from UDP-GlcNAc to phosphatidylinositol (PI), the first step in the biosynthetic pathway for glycosylphosphatidylinositols (GPIs). We asked whether an exogenous lipid corresponding to an early intermediate in this pathway can be taken up ...
Mizuguchi H - - 2001
The mechanism by which p-chlorophenoxyisobutyric acid (clofibric acid) induces striking changes in the proportion of the molecular species of phosphatidylcholine (PC) in rat liver was studied. Treatment of rats with clofibric acid strikingly increased the content of 1-palmitoyl-2-oleoyl (16:0-18:1) PC, but decreased the contents of 1-palmitoyl-2-docosahexaenoyl (16:0-22:6), 1-stearoyl-2-arachidonoyl (18:0-20:4), and ...
Sugiura Shinji - - 2001
The formation of reversed micellar systems composed of phosphatidylcholine (PC) and fatty acid was newly demonstrated by a significant increase in water content in the organic ethyl oleate phase when the micelles were prepared by the contact method. The solubilized water concentration in the reversed micellar organic phase reached 3 ...
Christian Printzen
A taxonomic study of corticolous species of Lecanora in the Sonoran Desert region containing usnic acids and not belonging to Lecanora s. str. is presented. Descriptions, notes on the ecology and distribution and a key to the 17 species recognized within the area are included. Lecanora coniferarum Printzen, L. latens ...
Selishcheva A A - - 2001
Liposomes made from phosphatidylcholine (PC) or PC-fatty acid ester mixtures have been shown to induce an activation of the respiratory burst in human blood monocytes and alveolar macrophages (AM). Incorporation of 1,2-diacylglycerol or arachidonic acid into PC liposomes significantly enhanced the effect. In the case of AM, the effect of ...
Roque M E - - 2001
The synthesis of phosphatidylcholine (PC) in rod outer segments (ROS) catalysed by lysophosphatidylcholine acyltransferase and phosphatidylethanolamine N-methyltransferase (PE N-MTase) was studied and the effects of natural (FA and lysophospholipids) and synthetic (Triton X-100, deoxycholate and CHAPS) surfactants was evaluated. In all experimental conditions used, incorporation of labelled oleate into lysophosphatidylcholine ...
Nomura T - - 2001
Phospholipase A2, which is linked to a protein kinase C pathway, hydrolyzes phosphatidylcholine into cis-unsaturated free fatty acids and lysophosphatidylcholine (lysoPC). The present study investigated the effect of the free fatty acids, such as arachidonic, oleic, linoleic, and linolenic acid, and lysoPC on neurotransmission by monitoring population spikes (PSs) from ...
Sawai T - - 2001
The activity of phospholipase A2 (PLA2) is elevated in the intestinal epithelia of patients with inflammatory bowel disease (IBD). We recently reported that PLA2 mediates hydrolysis of phosphatidylcholine (PC) to lysophosphatidylcholine (L-PC) when both are applied to the apical surface of cultured EC monolayers, resulting in increased bacterial translocation (BT) ...
Munnik T - - 2001
Evidence is accumulating that phosphatidic acid is a second messenger. Its level increases within minutes of a wide variety of stress treatments including ethylene, wounding, pathogen elicitors, osmotic and oxidative stress, and abscisic acid. Enhanced signal levels are rapidly attenuated by phosphorylating phosphatidic acid to diacylglycerol pyrophosphate. Phosphatidic acid is ...
1 2 3 4 5 6 7 8 9 10 >