bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐fat diets impede the lowering effect of cyclosporine a on rat brain lipids and interact with the expression of apolipoproteins E and J
Authors: Montpied Pascale , Domingo Nicole , Senft Michèle , Portugal Henri , Petit Pierre , Chanussot Françoise 
Published: November 2006

AbstractCyclosporine A (CsA), a common immunosuppressive agent, produces hyperlipidemia and apolipoprotein profile alterations in plasma as well as neurological and psychiatric complications. In rats, 10 mg CsA/kg/d treatments for 3 wk induce alterations of the electroencephalogram, and of the blood and brain lipids. Using this model, we evaluated whether triacylglycerol (TG)‐ and lecithin (PC)‐enriched diets, reported to decrease epileptic episodes (TG) and to improve memory, could modify the effects of CsA treatment on brain lipids and possibly change apolipoprotein (apo) E and apoJ gene expression. To evaluate this hypothesis, three groups of rats were treated for 3 wk with CsA and received a low‐fat, PC, or TG diet. Three other groups were fed the above‐mentioned diets and were treated with the CsA solvent. As a control, one group was fed only the low‐fat diet. The CsA‐mediated decreases in brain cholesterol and PC contents, under a low‐fat diet, were eliminated by the TG and PC diets. These high‐fat diets induced a global increase in hippocampal transcriptional activity, as revealed by elevated polyadenylated RNA levels. The apoE and apoJ mRNA levels in the cortex and hippocampus of rats receiving the solvent were not statistically different between the TG‐ and PC‐enriched diets but showed important variations compared with the low‐fat diet solvent‐treated group. A differential effect between the two high‐fat diets was obsorved in the hippocampus, resulting in a significant increase of the apoE to apoJ ratio with the PC diet. The balance between apoE and apoJ is presumed to be important in encephalopathic mechanisms, by its involvement through low levels of brain cholesterol and PC, that might be associated with mental disorders. Our results therefore suggest that diet enrichment with polyunsaturated fat might be beneficial during CsA therapy. However, if the high levels in PC used here are more beneficial on CsA peripheral side effects than similar enrichment in TG, this does not seem to be the case in the brain. Thus, lower levels in PC should be tested.
Molecular cloning, expression, and characterization of secretory phospholipase A2 in tobacco
Authors: Fujikawa Ritsuko , Fujikawa Yukichi , Iijima Noriaki , Esaka Muneharu 
Published: November 2006

AbstractPhospholipase A2 (PLA2) activity was investigated in various tissues of tobacco (Nicotiana tabacum). PLA2 activity in the flower was 15 times higher than that in the leaf, stem, and root. PLA2 activity in the flower appears to have originated from both Ca2+‐dependent and‐independent PLA2. A cDNA clone for protein with homology to animal secretory PLA2 (sPLA2), denoted as Nt PLA2, was isolated from the tobacco flower. The cDNA of Nt PLA2 encoded a mature protein of 127 amino acid residues with a putative signal peptide of 30 residues. The amino acid sequence for mature Nt PLA2 contains 12 cysteines, a Ca2+ binding loop, and a catalytic domain that are commonly conserved in animal sPLA2. The Nt PLA2 mRNA was mainly expressed in the root and stem of tobacco. The recombinant Nt PLA2 was expressed as a fusion protein with thioredoxin in Escherichia coli. From the bacterial cell lysate, the fusion protein was recovered in soluble form and cleaved by Factor Xa proteinase. Then the recombinant mature Nt PLA2 was purified by ion exchange chromatography. It was discovered that the purified Nt PLA2 essentially requires Ca2+, for the enzyme activity when the activity was determined using mixed‐micellar phospholipid substrates with sodium cholate. The optimal activity of Nt PLA2 was at pH 8–10 when PC was used as a substrate.
Dietary fish oil dose‐response effects on ileal phospholipid fatty acids and contractility
Authors: Patten Glen S. , Adams Michael J. , Dallimore A. , Abeywardena Mahinda Y. 
Published: November 2006

AbstractWe have reported that dietary fish oil (FO) leads to the incorporation of long‐chain n−3 PUFA into the gut tissue of small animal models, affecting contractility, particularly of rat ileum. This study examined the FO dose response for the incorporation of n−3 PUFA into ileal tissue and how this correlated with in vitro contractility. Groups of ten to twelve 13‐wk‐old Wistar‐Kyoto rats were fed 0, 1, 2.5, and 5% FO‐supplemented diets balanced with sunflower seed oil for 4 wk, after which ileal total phospholipid FA were determined and in vitro contractility assessed. For the total phospholipid fraction, increasing the dietary FO levels led to a significant increase first evident at 1% FO, with a stepwise, nonsaturating six‐fold increase in n−3 PUFA as EPA (20∶5n−3), DPA (docosapentaenoic acid, 22∶5n−3), and DHA, but mainly as DHA (22∶6n−3), replacing the n−6 PUFA linoleic acid (18∶2n−6) and arachidonic acid (20∶4n−6) over the dosage range. There was no difference in KCl‐induced depolarization‐driven contractility. However, a significant increase in receptor‐dependent maximal contractility occurred at 1% FO for carbachol and at 2.5% FO for prostaglandin E2, with a concomitant increase in sensitivity for prostaglandin E2 at 2.5 and 5% FO. These results demonstrate that significant increases in ileal membrane n−3 PUFA occurred at relatively low doses of dietary FO, with differential receptor‐dependent increases in contractility observed for muscarinic and prostanoid agonists.
Techniques for delivery of arachidonic acid to pacific oyster, Crassostrea gigas, spat
Authors: Seguineau C. , Soudant P. , Moal J. , Delaporte M. , Miner P. , Quéré C. , Samain J. ‐F. 
Published: November 2006

AbstractThe present study tested two techniques for dietary supplementation of Crassostrea gigas spat with PUFA, such as arachidonic acid (AA). The first technique consisted of a preliminary enrichment and growth of an algal concentrate (T‐ISO, Isochrysis sp.) with AA dissolved in an ethanol solution, the whole culture then being fed to the spat. This enrichment increased the AA weight percentage in T‐ISO neutral and polar lipids from 0.6 to 22.4% and from 0.4 to 6.8%, respectively. The second delivery technique was direct addition separately of free AA dissolved in ethanol solution and algal concentrate (T‐ISO+AA) to the spat‐rearing tank. To test the efficiency of these delivery techniques, oyster spat were supplemented with AA‐enriched T‐ISO, T‐ISO+AA, and T‐ISO alone. The possible biological impacts of these dietary treatments were assessed by measuring growth, condition index, and TAG content of oyster spat. Dry weight and condition index of spat fed AA‐enriched T‐ISO decreased by 24 and 49%, respectively, after 26 d of feeding; basically, TAG content declined 88% after 34 d of conditioning. When AA was added directly to seawater, spat growth and condition index were comparable with those of oysters fed T‐ISO alone. AA incorporation in oyster tissues was assessed by analysis of the FA compositions in both neutral and polar lipid fractions. After 34 d, AA content in neutral lipids reached 7 and 11.7% in the spat fed, respectively, AA‐enriched T‐ISO and T‐ISO+AA, as compared with 1.1% in spat fed only T‐ISO. AA incorporation was greater in polar lipids than in neutral lipids, reaching 7.8 and 12.5% in spat fed AA‐enriched T‐ISO and T‐ISO+AA, respectively. A direct addition of PUFA along with the food supply represents an effective and promising means to supplement PUFA to oyster spat.
High docosahexaenoic acid levels in both neutral and polar lipids of a highly migratory fish: Thunnus tonggol (Bleeker)
Authors: Saito Hiroaki , Seike Yutaka , Ioka Hisashi , Osako Kazufumi , Tanaka Mikiko , Takashima Akihito , Keriko Joseph M. , Kose Sevim , Souza Juan C. Rodriguez 
Published: November 2006

AbstractThe lipid and FA compositions of various organs (light muscle, dark muscle, liver, pyloric cecum, and the orbital region) and of the stomach contents of a highly migratory fish species Thunnus tonggol (Bleeker) were analyzed. TAG and phospholipids (PE and PC) were the major lipid classes in the total lipids of T. tonggol. DHA was characteristically the major FA of all the major classes of all its organs except for only one case of liver TAG. The mean DHA contents of the various organs accounted for more than 20% of the total FA (TFA), even though it is a neutral depot lipid. However, DHA in the stomach contents, originating from their prey, fluctuated and was generally low. DHA levels were generally higher in a year (2000) when water temperatures were colder than in one when it was warmer (1998). Furthermore, DHA levels in muscle TAG were consistently high in spite of the fluctuation of those in the visceral TAG, which might be directly influenced by the prey lipids. This phenomenon suggests the physiological selective accumulation of DHA in the muscle, after the migration of the digested FA in the vascular system and absorption of the prey lipids in the intestine. In contrast, the FA composition of other species is generally variable and their DHA contents of TAG are usually less than 20% of TFA.
Sesamol induces nitric oxide release from human umbilical vein endothelial cells
Authors: Chen Pey‐Rong , Tsai Chingmin E. , Chang Hang , Liu Tsuei‐Ling , Lee Chun‐Chung 
Published: November 2006

AbstractSesamol, which is derived from sesame seed lignans, is reportedly an antioxidant. Nitric oxide (NO), the most important vascular relaxing factor, is regulated in the endothelium. In addition, NO is involved in protecting endothelium and has antiatherosclerotic and antithrombotic activities. The endothelium produces NO through the regulation of both endothelial NO synthase (eNOS) expression and activity in endothelial cells. This study sought to investigate the effect of sesamol on NO released from human umbilical vein endothelial cells (HUVEC) and to examine the expression and activity of eNOS. Sesamol induced NO release from endothelial cells in a dose‐dependent manner (from 1 to 10 μM), as measured 24 h after treatment; the expression of the eNOS gene at both transcription and translation levels; and NOS activity in endothelial cells. The content of cGMP was also increased by sesamol through NO signaling. The transcription of eNOS induced by sesamol was confirmed through the activation of PI‐3 kinase‐Akt (protein kinase B) signaling. The results demonstrate that sesamol induces NOS signaling pathways in HUVEC and suggest a role for sesamol in cardiovascular reactivity in vivo.
Trans and positional ethylenic bonds in two dominant isomers of eicosapentaenoic acid from the freshwater sponge Baicalospongia bacillifera
Authors: Imbs Andrey B. , Rodkina Svetlana A. 
Published: November 2006

AbstractReinvestigation of the current FA composition of the regional freshwater sponge Baicalospongia bacillifera showed that the main measured isomer of EPA (14% of the total FA now detected) is, in fact, an unusual 5Z,8Z,11Z,14Z,18E‐EPA. Two other isomers of this acid also present were identified as a novel 5Z,8Z,11Z,15Z,18E‐EPA and the common methylene‐interrupted 5Z,8Z,11Z,14Z,17Z‐EPA (usually written simply as EPA). Isolation of these acids as their methyl ester derivatives was accomplished with the use of a combination of silver‐ion column chromatography and HPLC. The structure of the two new compounds was deduced from GC‐MS and detailed NMR data. Partial hydrazine reduction of all three isolated EPA esters followed by separation of cis/trans isomers of the resulting monoenoic acids and GC‐MS analysis of their dimethyl disulfide adducts were used for determination of the configuration and position of the double bonds. We may assume that the sponge B. bacillifera cannot receive these unusual EPA isomers directly from food sources (e.g., algal diatoms), and accordingly restructuring of ordinary EPA to novel acids may take place in the sponge tissue.
New fatty acid derivatives fromHomaxinellasp., a marine sponge
Authors: Mansoor Tayyab A. , Bae Bok Hee , Hong Jongki , Lee Chong‐O. , Im Kwang Sik , Jung Jee H. 
Published: November 2006

AbstractFractionation of the MeOH extract ofHomaxinellasp., a marine sponge, led to the isolation of a sodium salt of a new brominated FA (1), two new MG (2and4), and a new lysoPC (6). The geometry of the double bonds in1and2was defined by comparison of the NMR chemical shifts of the allylic carbons, nuclear Overhauser effect spectroscopy correlations of the allylic protons, and coupling constants of the vinylic protons with those reported. Evidence mainly from NMR and MS analyses established the planar structures of the compounds. Compounds1, 2, 4, and6were evaluated for cytotoxicity against a panel of five human solid tumor cell lines. Only compound1showed moderate activity.
Pathways for fatty acid elongation and desaturation in Neurospora crassa
Authors: McKeon Thomas A. , Goodrich‐Tanrikulu Marta , Lin Jiann‐Tsyh , Stafford Allan 
Published: November 2006

AbstractNeurospora crassa incorporated exogenous deuterated palmitate (16∶0) and 14C‐labeled oleate (18∶1Δ9) into cell lipids. Of the exogenous 18∶1Δ9 incorporated, 59% was desaturated to 18∶2Δ9,12 and 18∶3Δ9,12,15. Of the exogenous 16∶0 incorporated, 20% was elongated to 18∶0, while 37% was elongated and desaturated into 18∶1Δ9, 18∶2Δ9,12, and 18∶3Δ9,12,15. The mass of unsaturated fatty acids in phospholipid and triacylglycerol is 12 times greater than the mass of 18∶0. Deuterium label incorporation in unsaturated fatty acids is only twofold greater than in 18∶0, indicating a sixfold preferential use of 16∶0 for saturated fatty acid synthesis. These results indicate that the release of 16∶0 from fatty acid synthase is a key control point that influences fatty acid composition in Neurospora.
Correlation of ATP/citrate lyase activity with lipid accumulation in developing seeds of Brassica napus L.
Authors: Ratledge Colin , Bowater Moray D. V. , Taylor Philip N. 
Published: November 2006

AbstractThe temporal distribution of ATP/citrate lyase (ACL) activity in developing seeds of Brassica napus L. closely paralleled both that of acetyl‐CoA carboxylase and the overall rate of lipid biosynthesis. Maximum ACL activities (250 nmol acetyl‐CoA formed min−1·g fresh seed) were recorded between 35 to 42 d after pollination and, if the in vitro data could be extrapolated to the situation in vivo, could account for half of the acetyl‐CoA required for the measured rate of fatty acid biosynthesis during seed development. The enzyme appeared to be localized in a subcellular compartment, which was clearly separated from mitochondria on a sucrose gradient and by differential centrifugation, and which corresponded to the chloroplast organelle.
Digestion of the 1‐O‐alkyl diacylglycerol ethers of atlantic dogfish liver oils by Atlantic salmon Salmo salar
Authors: Kang S. ‐J. , Lall S. P. , Ackman R. G. 
Published: November 2006

AbstractDogfish (Squalus acanthias) liver poses a waste disposal problem in Canada because it is not utilized for any commercial purpose. The liver of Atlantic dogfish, which is often up to 20% of the weight of the fish, contains 40–70% oil. The oil contains about 30–40% 1‐O‐alkyl diacylglycerol ethers (DAGE) which render it unacceptable for human use, and it has also not been considered satisfactory for animal feed use. Polyunsaturated fatty acids (20∶5n−3 and 22∶6n−3) are present in dogfish liver oils at levels comparable to those in herring oil. Dogfish liver oil could be a source of essential fatty acids for Atlantic salmon (Salmo salar), but their ability to hydrolyze DAGE from dogfish oil has not been examined. Experiments were designed to measure the digestibility of fatty acids of DAGE in salmon. The fatty acid moieties were liberated by the digestive enzymes of the fish and made readily available as a source of energy. The 1‐O‐alkylglycerol ether moiety was absorbed to a small extent but should not constitute a health problem in either the fish or the human fish consumer. The long‐chain polyunsaturated fatty acids were particulary well absorbed, with an apparent digestibility in salmon of 87–95% when feeding on dogfish liver oil. The total fatty acids and other lipids were in fact both absorbed to the extent of approximately 85%.
Synthesis of a novel vitamin E derivative, 2‐(α‐d‐glucopyranosyl)methyl‐2,5,7,8‐tetramethylchroman‐6‐ol, by α‐glucosidase‐catalyzed transglycosylation
Authors: Murase Hironobu , Yamauchi Ryo , Kato Koji , Kunieda Tsutomu , Terao Junji 
Published: November 2006

AbstractA novel derivative of vitamin E, vitamin E glucoside, was synthesized from 2‐hydroxymethyl‐2,5,7,8‐tetramethylchroman‐6‐ol and maltose in a solution containing DMSO by transglycosylation with α‐glucosidase from Saccharomyces species. The glycosylated product was identified as 2‐(α‐d‐glucopyranosyl)methyl‐2,5,7,8,‐tetramethylchroman‐6‐ol (TMG) by mass spectrometry and nuclear magnetic resonance spectroscopy. The optimal pH of transglycosylation was 5.5, and the yield of TMG increased as the concentration of maltose increased. IMG has high solubility in water (>1×103 mg/mL). The 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity of TMG was found to be nearly the same as those of α‐tocopherol, Trolox (2‐carboxy‐2,5,7,8‐tetramethylchroman‐6‐ol), and ascorbic acid.
Biotransformations of tocopherols by Streptomyces catenulae
Authors: Rousseau Brigitte , Dostal Larry , Rosazza John P. N. 
Published: November 2006

AbstractStreptomyces catenulae catalyzed the oxidation of α‐tocopherol to α‐tocopherolquinone. Nitrotocopherols isolated from S. catenulae grown in defined culture medium containing δ‐and γ‐tocopherols are formed by a combination of enzymatic nitrate reduction to nitrite, and subsequent nonenzymatic acid‐catalyzed nitration. The incorporation of 15N18O3‐into nitrated tocopherols confirmed the origin of the nitrating species. Structures of chromatographically purified products obtained from S. catenulae transformations of tocopherols were deduced by spectral (mass spectrometry, 1H‐, and 13C‐nuclear magnetic resonance) analyses.
Analysis of hydroxy and keto cholesterols in oxidized brain synaptosomes
Authors: Vatassery Govind T. , Quach Hung T. , Ed Smith W. , Krick Thomas P. , Ungar Frank 
Published: November 2006

AbstractA rapid method for the simultaneous determination of cholesterol and its oxidation products as well as α‐tocopherol and tocopherolquinone in brain subcellular fractions is described. The samples are saponified and extracted with hexane. It is not necessary to remove cholesterol in the sample before analyzing for oxysterols. The hexane extract can be used for the assay of cholesterol compounds by capillary gas chromatography and tocopherol compounds by liquid chromatography using a procedure reported previously. Oxidation of synaptosomes by a mixture of Fe2+ plus ascorbate resulted in the production of 7‐keto‐, 7α‐hydroxy‐, 7β‐hydroxy‐, and 5α, 6α‐epoxycholesterols. The identities of these products were confirmed with gas chromatography/mass spectrometry. Cholesterol oxidase treatment did not result in the formation of any of the above compounds. Thus the types and amounts of the products of oxidation of cholesterol were dependent upon the oxidizing agent. Extraction of the oxysterols under milder conditions without saponification using sodium dodecyl sulfate cannot be used since such treatment results in low recovery of oxysterols. Oxidation of synaptosomes by low concentrations of ferrous iron and ascorbate resulted in (i) low levels of oxidation of cholesterol which could be followed by estimating the production of oxysterols and (ii) oxidation of a substantial percentage of α‐tocopherol. The proposed procedure will be useful in monitoring the oxidation of small quantities of membrane cholesterol in vitro.
The effects of infusion of trieicosapentaenoyl‐glycerol emulsion on extravascular lung water during myocardial ischemia and reperfusion in dogs
Authors: Izuoka Toshio , Kimura Yutaka , Hamazaki Tomohito , Tamura Teruhiro , Kitashiro Shuji , Sugiura Tetsuro , Jikuhara Toshimitsu , Iwasaka Toshiji 
Published: November 2006

AbstractTo test the effects of eicosapentaenoic acid (EPA) infusion on pulmonary edema induced by coronary ligation and reperfusion, extravascular lung water (EVLW) was measured in situ by the thermal‐dye double indicator dilution method in dogs. In the control group of five dogs, 30 mL of a 10% soybean oil emulsion was infused through a leg vein. One hour after infusion, the left anterior descending coronary artery below the first diagonal branch was ligated for 15 min and then reperfused for 30 min. In the EPA group, six dogs were similarly treated with an emulsion of a 10% trieicosapentaenoyl‐glycerol (90% pure). EVLW, pulmonary capillary wedge pressure, mean pulmonary artery pressure, mean blood pressure, and cardiac index were measured before and 15 min after coronary ligation, and 15 min and 30 min after coronary reperfusion. There were no significant differences in the hemodynamic indices between the two groups. EVLW significantly increased up to two times of baseline during coronary ligation in the control group (P< 0.05) and more during reperfusion (P<0.01), whereas EVLW did not increase in the EPA group. In conclusion, EPA inhibited EVLW accumulation and may be useful for ameliorating one of the ischemia‐reperfusion‐induced complications, pulmonary edema.
Altered acyl chain length specificity of Rhizopus delemar lipase through mutagenesis and molecular modeling
Authors: Klein Robert R. , King Gregory , Moreau Robert A. , Haas Michael J. 
Published: November 2006

AbstractThe acyl binding site of Rhizopus delemar prolipase and mature lipase was altered through site‐directed mutagenesis to improve lipase specificity for short‐or medium‐chain length fatty acids. Computer‐generated structural models of R. delemar lipase were used in mutant protein design and in the interpretation of the catalytic properties of the resulting recombinant enzymes. Molecular dynamics simulations of the double mutant, val209trp+phe112trp, predicted that the introduction of trp112 and trp209 in the acyl binding groove would sterically hinder the docking of fatty acids longer than butyric acid. Assayed against a mixture of triacylglycerol substrates, the val209trp+phe112trp mature lipase mutant showed an 80‐fold increase in the hydrolysis of tributyrin relative to the hydrolysis of tricaprylin while no triolein hydrolysis was detected. By comparison, the val94Trp mutant, predicted to pose steric or geometric constraints for docking fatty acids longer than caprylic acid in the acyl binding groove, resulted in a modest 1.4‐fold increase in tricaprylin hydrolysis relative to the hydrolysis of tributyrin. Molecular models of the double mutant phe95asp+phe214arg indicated the creation of a salt bridge between asp95 and arg214 across the distal end of the acyl binding groove. When challenged with a mixture of triacylglycerols, the phe95asp+phe214arg substitutions resulted in an enzyme with 3‐fold enhanced relative activity for tricaprylin compared to triolein, suggesting that structural determinants for medium‐chain length specificity may reside in the distal end of the acyl binding groove. Attempts to introduce a salt bridge within 8 Å of the active site by the double mutation leu146lys+ser115asp destroyed catalytic activity entirely. Similarly, the substitution of polar Gln at the rim of the acyl binding groove for phe 112 largely eliminated catalytic activity of the lipase.