bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acidic hydrolysis of plasmalogens followed by high‐performance liquid chromatography
Authors: Murphy Eric J. , Stephens Ralph , Jurkowitz‐Alexander Marianne , Horrocks Lloyd A. 
Published: November 2006

AbstractA simple, quantitative method for determining the plasmalogen content of small samples is reported here. The method uses the different susceptibility to acid‐catalyzed hydrolysis of the alkyl, alkenyl and acyl linkages to separate the plasmalogen subclass from the other two non‐labile subclasses. Hydrolysis of plasmenylethanolamine and plasmenylcholine was complete after 4 and 1 min of acid treatment, respectively. The acid‐catalyzed hydrolysis did not alter the phospholipid fatty acid composition, making this method useful for fatty acid compositional analysis of the plasmalogen subclass. High‐performance liquid chromatography was used for separations, and phospholipids were quantitated by assay of lipid phosphorus or by direct quantitation of peak area. Using this method, small amounts (10 nmol) of ethanolamine glycerophospholipid and choline glycerophospholipid are subjected to acid‐catalyzed hydrolysis and subsequent separation of the resulting lysocompounds obtained from plasmalogens from the more acid‐stable alkylacyl and diacyl glycerophospholipid fractions. Our values for plasmalogens from commercial preparations of choline and ethanolamine glycerophospholipids agree with literature values. The usefulness of the method is demonstrated for small glycerophospholipid samples that are equivalent to samples from cultured neural cells.
Dietary lipids modify the fatty acid composition of cartilage, isolated chondrocytes and matrix vesicles
Authors: Xu Hui , Watkins A. , Adkisson Huston D. 
Published: November 2006

AbstractThe effects of dietary lipids on the fatty acid composition of hyaline cartilage, epiphyseal chondrocytes (EC) and matrix vesicles (MV) were evaluated in chicks. A basal semipurified diet was fed to chicks containing one of the following lipid sources at 70 g/kg: soybean oil, butter+corn oil, margarine+corn oil or menhaden oil+corn oil (MEC). Articular and epiphyseal growth cartilage were isolated from the proximal tibiotarsus; EC and MV were subsequently released by trypsin (EC 3.4.21.4) and collagenase (EC 3.4.24.3) digestion followed by ultracentrifugation. The fatty acid composition of polar lipids in chick epiphyseal cartilage at three and six weeks, as well as articular cartilage, EC and MV at eight weeks of age revealed the presence of high levels of saturated and monounsaturated fatty acids (up to 85.5%) but low levels of n−6 polyunsaturated fatty acids (PUFA) (2.6–10.2%). Mead acid (20∶3n−9,>3%) was also present in cartilage, EC and MV lipids, and was unaffected by the dietary lipid treatments. Total n−3 PUFA concentrations were the highest in cartilage, EC and MV of chicks consuming MEC. Feeding MEC lowered the levels of 20∶4n−6 in cartilage, but increased 20∶5n−3 levels. The data are consistent with those reported previously which showed that cartilage tissues are low in n−6 PUFA and that they contain 20∶3n−9. We furthermore demonstrated that the PUFA composition of cartilage can be modified by dietary lipids.
Fatty acid composition of lung, macrophage and surfactant phospholipids after short‐term enteral feeding with n−3 lipids
Authors: Palombo John D. , Lydon Erin E. , Chen Pei‐Linn , Bistrian Bruce R. , Forse R. Armour 
Published: November 2006

AbstractUtilization of enteral feeding modalities may prove clinically relevant for rapid modulation of lung phospholipid polyunsaturated fatty acids (PUFA) that serve as substrates for the formation of vasoactive dienoic eicosanoids. We compared the effects of short‐term enteral feeding with formulations enriched with either fish (n−3) or corn (n−6) oil PUFA on the fatty acid composition of rat lung, alveolar macrophage and surfactant phospholipids. The diets were infused continuously for 72 h through a surgically placed gastroduodenal feeding catheter by a syringe pump. The n−3 PUFA derived from the fish oil enriched diet were readily incorporated into the phospholipid membranes of the alveolar macrophages, lung tissue and pulmonary surfactant. The relative percentages of the n−3 PUFA were significantly higher and individual and total n−6 PUFA significantly lower in the macrophage, lung and surfactant phospholipids from the n−3‐supplemented rats in comparison with those present in the rats infused enterally with the n−6 diet or untreated, chow‐fed rats (baseline). In contrast, there was a significant increase in linoleic acid (18∶2n−6) without modification of arachidonic acid (20∶4n−6) in the alveolar macrophages, lung tissue and surfactant from rats enterally receiving the n−6 diet relative to levels measured in the rats at baseline. The results suggest that short‐term continuous delivery of n−3‐enriched enteral preparations can foster rapid modification of membrane phospholipid PUFA composition of lung tissue, alveolar macrophages and lung surfactant. Utilization of similar infusion modalities to deliver n−3‐enriched enteral formulations may prove beneficial to critically ill or postoperative patients with persistent lung inflammation secondary to uncontrolled formation of vasoactive eicosanoids derived from arachidonic acid.
Sterols of eustigmatophytes
Authors: Patterson G. W. , Tsitsa‐Tzardis E. , Wikfors G. H. , Ghosh P. , Smith B. C. , Gladu P. K. 
Published: November 2006

AbstractThe oyster cannot synthesize sterols from smaller molecules but must obtain them from its diet, which consists of detritus and small organisms, i.e., mostly single‐celled algae. Algae differ widely in their effectiveness as oyster food. Small (<5 μm) algae which are abundant in sterols and polyunsaturated fatty acids appear to be most effective. Recent studies have shown the occurrence of cholesterol in strains of the unicellular algaeTetraselmis, Chaetoceros andSkeletonema, sometimes in large quantities. In the study reported here, six isolates of a recently constructed algal class, the Eustigmatophyceae, have been examined for sterols and fatty acids by gas chromatography and gas chromatography/mass spectrometry. All strains were shown to contain cholesterol as the principal sterol. Two isolates contained large amounts of total sterol (400–1000 fg/cell), and one (Sticho 0–18) also contained large amounts of eicosapentaenoic acid (20∶5n−3). These biochemical characteristics are desirable in a potential food source for oysters.
Purification and characterization of an extracellular lipase from the fungusRhizopus delemar
Authors: Haas Michael J. , Cichowicz David J. , Bailey David G. 
Published: November 2006

AbstractThe complete purification and characterization of an extracellular lipase (acylglycerol acylhydrolase, EC 3.1.1.3) fromR. delemar is described. The final product was homogeneous as judged by electrophoresis in denaturing polyacrylamide gels and by isoelectric focusing, and was shown by means of an activity stain to be lipolytic. The purified enzyme had a monomer molecular weight of 30,300, an isoelectric point of 8.6, and approximately one monosaccharide moiety per molecule.N‐Terminal sequence data (28 residues) and the amino acid composition of the lipase indicated that it corresponds to the product of a lipase‐encoding cDNA previously isolated fromR. delemar. Optimal activity occurred between pH 8.0 and 8.5. The activity and stability of the enzyme were maximum at 30°C. Divalent cations were required for activity, with barium, calcium and manganese conferring maximum activity. Activation by calcium was maximal at and above 10 mM. The lipase was not inactivated by reducing agents, sodium fluoride or phenylmethlsufonyl fluoride. It was resistant toN‐ethylmaleimide, and inactivated byp‐chloromercuribenzoic acid in a manner which was not reversed by cysteine.
Reversible ATP‐dependent inactivation of adipose diacylglycerol acyltransferase
Authors: Rodriguez M. A. , Dias C. , Lau T. E. 
Published: November 2006

AbstractDiacylglycerol acyltransferase from rat adipose tissue is shown to be inactivated by 30 to 40% upon incubation with adenosine 5′‐triphosphate (ATP) and Mg2+. The activity responsible for this inactivation is associated with the cytosolic fraction, specific for ATP, prevented when ATP is substituted by β,γ‐methylene‐ATP, and partially blocked by 1 mM ethylenediaminetetraacetate or 40 mM NaF, but not by inhibitors of adenosine 3′,5′‐cyclic‐monophosphate (cAMP)‐dependent protein kinase and/or protein kinase C (PKC). The cytosolic activity cannot be mimicked by (cAMP)‐protein kinase nor by PKC. Inactivated diacylglycerol acyltransferase from ATP/cytosol‐treated microsomes can be reactivated by incubation with partially purified protein phosphate from rat liver, and can be inactivated again by further addition of ATP in the presence of cytosol. The results suggest the existence in adipose tissue of a protein kinase other than cAMP‐protein kinase or PKC, which may be involved in the regulation of triacylglycerol synthesis.
Increments of dietary linoleate raise liver arachidonate, but markedly reduce heart n−6 and n−3 fatty acids in the rat
Authors: Marangoni Franca , Mosconi Cristina , Galella Gerardina , Galli Claudio 
Published: November 2006

AbstractFour diets containing 20% of energy (en%) as fat and with linoleic acid contents of 1.9, 3.1, 7.7 and 10.1 en%, respectively, were fed to one‐month‐old male rats for three months. The fatty acid profiles and the levels of the major n−6 and n−3 fatty acids in the lipids of plasma, liver, heart and kidney were measured. We found that with increasing concentrations of 18∶2n−6 in the diet, linoleic acid rose in plasma and in all organs, but long‐chain n−6 and n−3 fatty acids responded differently. In liver, arachidonic acid increased and n−3 fatty acids were not significantly affected; in heart, both arachidonic and docosahexaenoic acids were progressively reduced; and in kidney, there was no change of n−6 and n−3. The results indicate that incremental changes in dietary, linoleate affect the levels of polyunsaturated fatty acids in liver and extrahepatic organs differently.
Incorporation of n−3 fatty acids of fish oil into tissue and serum lipids of ruminants
Authors: Ashes John R. , Siebert Brian D. , Gulati Suresh K. , Cuthbertson Abla Z. , Scott Trevor W. 
Published: November 2006

AbstractThis study examines the biohydrogenation and utilization of the C20 and C22 polyenoic fatty acids in ruminants. Eicosapentaenoic (20∶5n−3) and docosahexaenoic (22∶6n−3) acids were not biohydrogenated to any significant extent by rumen microorganisms, whereas C18 polyenoic fatty acids were extensively hydrogenated. The feeding of protected fish oil increased the proportion of 20∶5 from 1% to 13–18% and 22∶6 from 2% to 7–9% in serum lipids and there were reductions in the proportion of stearic (18∶0) and linoleic (18∶2) acids. The proportion of 20∶5 in muscle phospholipids (PL) increased from 1.5% to 14.7% and 22∶6 from 1.0% to 4.2%; these acids were not incorporated into muscle or adipose tissue triacylglycerols (TAG). In the total PL of muscle, the incorporated 20∶5 and 22∶6 substituted primarily for oleic (18∶1) and/or linoleic (18∶2) acid, and there was no consistent change in the porportion of arachidonic (20∶4) acid.
Positional analyses of triacylglycerol fatty acids in the milk fat of the antarctic fur seal (Arctocephalus gazella)
Authors: Puppione Donald L. , Kuehlthau Cindy M. , Jandacek Ronald J. , Costa Daniel P. 
Published: November 2006

AbstractThe positional distribution of fatty acids has been determined for the milk triacylglycerols of the Antarctic fur seal,Arctocephalus gazella. Of particular interest was the positional distribution of the polyunsaturated n−3 fatty acids in milk triacylglycerols (TG). In adipocytes of pinnipeds, TG are synthesized with the n−3 fatty acids primarily in thesn‐1,3 positions. To determine the positional distribution, extracts of enzymatically digested lipids were separated by thin‐layer chromatography, and the constituent fatty acids were separated and quantified by gas‐liquid chromatography. Monoenoic and saturated fatty acids comprised over 75% of the total, the ratio of monoenoic to saturated fatty acids being 2∶1. The percent content of the long‐chain n−3 fatty acids, 20∶5, 22∶5 and 22∶6, ranged between 15–20%. The positional analyses revealed that at thesn‐2 position of milk TG, saturated fatty acids were in excess (57%), and the content of n−3 fatty acids was less than 5%. More than 80% of the n−3 fatty acids in milk were located in thesn‐1,3 positions. The data indicate that in pinnipeds TG are synthesized in the mammary gland and adipose tissue with fatty acids having similar positional distributions.
Preparation, chromatography and mass spectrometry of cholesteryl ester and glycerolipid‐bound aldehydes
Authors: Kamido H. , Kuksis A. , Marai L. , Myher J. J. , Pang H. 
Published: November 2006

AbstractTo identify lipid ester core aldehydes (aldehydes still bound to parent lipid molecules) among the secondary products of peroxidation, we have prepared reference standards of cholesteryl esters, diacylglycerols and the common glycerophospholipids (GPL) containing an aldehyde function. We subjected the unsaturated lipid esters to hydroxylation with osmium tetroxide and to carbon‐carbon bond cleavage with periodic acid. The resulting aldehyde esters (mainly 5‐oxovalerates and 9‐oxononanoates of cholesterol and the glycerolipids) were isolated and purified by thin‐layer chromatography (TLC) and reverse‐phase high‐performance liquid chromatography (HPLC). Liquid chromatography/mass spectrometry (LC/MS) was used to identify the cholesteryl and other neutral lipid ester aldehydes as the dinitrophenylhydrazones (DNPH). The choline (CGPL) and ethanolamine (EGPL) glycerophospholipids containing core aldehydes were identified by fast atom bombardment mass spectrometry (FAB‐MS) and by gas chromatography/mass spectrometry (GC/MS) of the aldehyde‐containing diacylglycerol moieties following dephosphorylation with phospholipase C and preparation of the methoximes (MOX) and the trimethylsilyl (TMS) ethers. The lipid esters containing the C5 and C9 aldehydes are chemically stable compounds with excellent chromatographic properties yielding mass spectra characteristic of the parent compounds. The overall yield of the core aldehydes was 10–20% of the unsaturated starting material.
Seawater fatty acids and lipid classes in an urban and a rural Nova Scotia inlet
Authors: Parrish Christopher C. , Bodennec Guy , Macpherson Ena J. , Ackman Robert G. 
Published: November 2006

AbstractSeawater samples collected in the summer of 1989 in Nova Scotia inlets were analyzed for lipid content to examine water quality. One inlet, the Northwest Arm, is located adjacent to an urban center, while the other, Ship Harbour, is located in an uninhabited area and contains three commercial mollusk farms. Lipids in the dissolved and particulate fractions were measured by Chromarod‐Iatroscan thin‐layer chromatography with flame ionization detection and by gas chromatography. Samples collected near the urban center had higher levels of particulate hydrocarbons (28±15 μg/L) than those collected in the relatively pristine environment (11±1 μg/L). The urban center samples also had higher levels of particulate free aliphatic alcohols (14±5vs. 8±1 μg/L) and free fatty acids (5±1vs.<0.5 μg/L), suggesting degradation of wax esters and other fatty acid esters. Dissolved and particulate matter fatty acids contained a higher proportion of monounsaturated acids near the urban center (33–35vs. 25–29% of the total fatty acids). The essential fatty acids 20∶5n−3 (eicosapentaenoic acid) and 22∶6n−3 (docosahexaenoic acid), presumably of algal origin, were more prominent in the pristine environment (up to 3.5%), where mollusk aquaculture is practiced. Fatty acid markers of toxic algae were virtually absent (<0.2%) in samples taken from both locations.
5c, 11c, 14c‐Eicosatrienoic acid and 5c, 11c, 14c, 17c‐eicosatetraenoic acid ofBiota orientalis seed oil affect lipid metabolism in the rat
Authors: Ikeda Ikuo , Oka Takayuki , Koba Kazunori , Sugano Michihiro , Lie Ken Jie Marcel S. F. 
Published: November 2006

AbstractThe effects of 5c, 11c, 14c‐eicosatrienoic acid (20∶3BSO) and 5c, 11c, 14c, 17c‐eicosatetraenoic acid (20∶4BSO), polyunsaturated fatty acids (PUFA) contained inBiota orientalis seed oil (BSO), on lipid metabolism in rats were compared to the effects of fats rich in linoleic acid (LA) or α‐linolenic acid (ALA) under similar conditions. The potential effect of ethyl 20∶4BSO as an essential fatty acid also was examined in comparison with the ethyl esters of LA. ALA and γ‐linolenic acid (GLA). BSO‐ and ALA‐rich fat decreased the concentration of plasma total cholesterol, high density lipoprotein cholesterol, triglyceride and phospholipid as compared to LA‐rich fat. BSO was more effective in reducing plasma cholesterol concentrations than was the ALA‐rich fat. Dietary BSO markedly decreased the hepatic triglyceride concentration as compared to the LA‐rich or ALA‐rich fats. Aortic production of prostaglandin I2 tended to decrease in rats fed BSO or ALA‐rich fat compared to those fed the LA‐rich fat. Adenosine diphosphate‐induced platelet aggregation was similar in the three groups. The proportion of arachidonic acid (AA) in liver phosphatidylcholine (PC) of rats fed BSO was lowest compared to that of rats fed ALA‐rich or LA‐rich fats. Administration of 20∶4BSO, ALA or GLA to essential fatty acid‐deficient rats decreased the ratio of 20∶3n−9 to AA in liver PC to the same extent; administration of LA was more effective. The results indicate that the effects of specific PUFA contained in BSO on lipid metabolism are different from those of LA and ALA. It is also suggested that 20∶4BSO may exhibit some essential fatty acid effects.
Inhibitory effect of curcumin on fatty acid desaturation inMortierella alpina 1S‐4 and rat liver microsomes
Authors: Shimizu Sakayu , Jareonkitmongkol Saeree , Kawashima Hiroshi , Akimoto Kengo , Yamada Hideaki 
Published: November 2006

AbstractAn extract of rhizomes ofCurcuma longta L. (turmeric) inhibited the desaturation of dihomo‐γ‐linolenic acid (DGLA) in the arachidonic acid (AA) producing fungusMortierella alpina 1S‐4. The factor responsible for this phenomenon was isolated and identified as curcumin (diferuloyl methane). Mycelial DGLA levels increased about two‐fold (22.3 mg/g dry weight) with a concomitant decrease in AA levels when the fungus was cultivated with curcumin. The 50% inhibitory concentration against Δ5 desaturase was 27.2 μM. Curcumin also inhibited rat liver microsomal Δ5 and Δ6 desaturases.
Dietary fat and fatty acids modulate cholesterol cholelithiasis in the hamster
Authors: Cohen Bertram I. , Mosbach Erwin H. , Ayyad Nariman , Miki Shigeo , McSherry Charles K. 
Published: November 2006

AbstractWe tested two hypotheses, i) whether the type and the amount of fat in the diet will affect the formation of cholesterol gallstones in the hamsters, and ii) whether palmitic acid, a major fatty acid component of butterfat, can act as a potentiator of cholesterol cholelithiasis in the hamster. Young, male golden Syrian hamsters (Sasco) were fed a semipurified diet containing casein, corn starch, cellulose and cholesterol (0.3%) to which various types and amounts of fat (butterfat, olive oil, menhaden oil, corn oil) were added. All diets contained 2% corn oil to supply essential fatty acids to the growing hamsters. No deaths or illness occurred during the experiment. Animals fed the semipurified diet plus 4% butterfat (group 1) had a gallstone incidence of 63%. Replacement of butterfat with either olive oil, corn oil or menhaden oil prevented the formation of cholesterol gallstones entirely (groups 2–4). When total butterfat was increased from 4% to 8% (group 8), the incidence of cholesterol gallstones increased to 80%. Substitution of 4% olive oil (group 5), corn oil (group 6), or menhaden oil (group 7) for the additional 4% butterfat significantly reduced gallstones to 35%, 45% and 30%, respectively. The replacement of 4% butterfat with 1.2% palmitic acid gave the highest incidence of cholesterol gallstones (95%). These results suggest that butterfat (and one of its components, palmitic acid) intensifies gallstone formation in this model whereas mono‐ and polyunsaturated fats act as inhibitors of cholesterol cholelithiasis. A fatty acid, possibly palmitic acid, appears to act as lithogen in our model.
Changes in blood lipids and fibrinogen with a note on safety in a long term study on the effects of n−3 fatty acids in subjects receiving fish oil supplements and followed for seven years
Authors: Saynor Reginald , Gillott Timothy 
Published: November 2006

AbstractThe present study was designed to assess the effectiveness of the n−3 fatty acids in modifying serum total, low density lipoprotein and high density lipoprotein (HDL) cholesterol, as well as serum triglycerides, over a seven‐year period. Changes in plasma fibrinogen were recorded and long term safety assessed. A total of 365 subjects with ischemic heart disease (IHD), hyperlipidemia or a strong family history of IHD had their diet supplemented with MaxEPA (Seven Seas Ltd., Hull, England) fish oil containing 18–19% eicosapentaenoic acid. Venous blood samples were taken at regular intervals for lipid and fibrinogen assays and routine clinical chemistry and hematological profiling. Current medication was recorded and no further dietary modification was attempted. Triglyceride and fibrinogen were significantly reduced, whereas a significant reduction in total cholesterol occurred only in the subjects with a pre‐oil level>6.5 mmol/L. HDL cholesterol significantly increased over the study period. Clinical chemistry and hematological profiles were not adversely affected, and platelet count did not change significantly. The type of lipid changes observed were those usually considered antiatherogenic. Reducing fibrinogen may result in beneficial changes in the pathological processes leading to thrombotic occlusion. The consumption of MaxEPA by our patients over a seven‐year period did not indicate any adverse effects.
Production of eicosapentaenoic acid by freshwaterVibrio
Authors: Ringø Einar , Jøstensen Jens Petter , Olsen Rolf Erik 
Published: November 2006

AbstractArctic charr,Salvelinus alpinus (L.), were fed a moist pellet diet based on casein, dextrin and coconut oil in fresh water. The diet contained substantial amounts of saturated fatty acids, especially 12∶0. Polyunsaturated fatty acids in the n−3 series were not detected in the diet, but analysis of the intestinal liquor stripped from the charr showed that eicosapentaenoic acid (EPA, 20∶5n−3) accounted for 3.5% of fatty acids in total lipid. Colony forming units (CFU) of aerobic microorganisms were approximately 104 per mL intestinal liquor. Seventeen bacterial strains isolated from the intestinal liquor were screened for EPA production. Four isolates contained a high proportion of EPA in their total lipid. These isolates belong to the speciesVibrio.