bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyunsaturated fatty acid changes suggesting a new enzymatic defect in Zellweger Syndrome
Authors: Martinez Manuela 
Published: November 2006

AbstractThe fatty acid composition of red blood cells, fibroblasts, forebrain, liver and kidney were studied in a 3‐month‐old infant who died from Zellweger Syndrome, and the results were compared with those of age‐matched controls. Besides a typical increase in the very long chain fatty acids 26∶0 and 26∶1 and a great reduction in the plasmalogen levels, confirming the diagnosis of Zellweger Syndrome, some striking changes in the polyunsaturated fatty acid patterns were discovered. The most important was a very drastic decrease in the values of 22∶6ω3 and 22∶5ω6, the two products of Δ4‐desaturation. In the kidney, the level of 22∶6ω3 fell below that of 26∶0. Consequently, the ratio 26∶0/22∶6ω3 (and 26∶1/22∶6ω3) was most useful in emphasizing the fatty acid anomalies, especially in renal tissue, where the 26∶0/22∶6ω3 ratio increased to almost 200 times the normal values. Other significant, although less consistent fatty acid alterations were increases in 18∶2ω6, 18∶3ω6, 20∶3ω6, 18∶4ω3 and 20∶4ω3, and a decrease in 20∶4ω6 in some tissues. The existence is proposed of a new enzyme defect in peroxisomal disorders, involving the desaturase system of long chain polyunsaturated fatty acids.
Oxidation of vitamin E in red cell membranes by fatty acids, hydroperoxides and selected oxidants
Authors: Vatassery G. T. 
Published: November 2006

AbstractOur laboratory previously reported that vitamin E (tocopherol) in human blood platelets was oxidizedin vitro by various oxidants. This paper shows that diamide, superoxide, hydroperoxides and polyunsaturated fatty acids induced oxidation of tocopherols in red cell membranes. In contrast to platelets, red cell membrane tocopherol was oxidized by hydrogen peroxide and tertiary butyl hydroperoxide. Alpha tocopherolquinone was one of the products of oxidation. Among the fatty acids, thecis polyunsaturated acids were the most potent oxidizing agents with monounsaturated andtrans compounds relatively ineffective. The oxidation is not a detergent effect of the fatty acids since neither the detergents Brij and Lubrol, when present in concentrations under 0.5 mM, nor sodium arachidate (1.25 mM), could oxidize the membrane tocopherol. When red cell membrane samples were incubated with 0.5 mM arachidonate, 47±11% (S.D.) of the tocopherol lost was converted to tocopherolquinone. Unlike arachidonate, oxidants such as diamide, hydrogen peroxide and tertiary butylhydroperoxide are unable to oxidize all of the membrane tocopherol and produce less tocopherolquinone from oxidation (10–15%) under the experimental conditions of this study. Linoleic acid hydroperoxide is a much more potent oxidant and produces less quinone than arachidonate. The mechanisms of tocopherol oxidations induced by the various compounds seem to be different since the yields of quinone during oxidation vary with the nature of the oxidant. Tocopherol is consumed by oxidation as it protects the membrane from oxidant damage induced by compounds such as unsaturated fatty acids and hydroperoxides.
Environmental temperature and metabolism of the molecular species of phosphatidylcholine in the tissues of the rainbow trout
Authors: Malak Nabil Abdul , Brichon Gerard , Meister Roger , Zwingelstein Georges 
Published: November 2006

AbstractThe phospholipid composition and the fatty acid pattern of phosphatidylcholine from major tissues of the rainbow trout acclimated to 11° and 21°C were analyzed. A significant difference in the level of 20∶5ω3 fatty acid between gill, kidney, intestine and liver phosphatidylcholine is observed in both groups of animals. These differences correlate with a modification of the molecular species distribution in the phosphatidylcholine in these organs. In vivo incorporation of32P into phospholipids of gills, kidney, intestine, liver and muscle was determined in trout acclimated to 11° and 21°C. Temperature acclimation specifically modify the relative specific radioactivity of the monoene and hexaene molecular species of phosphatidylcholine in gills, intestine, kidney and liver. It can be concluded from these results, that the metabolism of the diacylglycerol moiety and the coupled fatty acids of phosphatidylcholine differs with the tissue and the temperature. It is suggested that different associated mechanisms specific for each organ determine the fatty acid composition of phophatidylcholine required for its physiological functions at each temperature.
Sterol metabolism in the nematodePanagrellus redivivus
Authors: Salt Thomas A. , Chitwood David J. , Lusby William R. 
Published: November 2006

AbstractPanagrellus redivivus was propagated in media containing three structurally different sterols: 7‐dehydrocholesterol, campesterol or stigmastanol. Nematodes propagated with 7‐dehydrocholesterol contained mostly lathosterol and 7‐dehydrocholesterol. Nematodes propagated with campesterol contained mostly cholesterol and cholestanol. Nematodes propagated with stigmastanol contained mostly cholestanol. The sterol ester fraction was enriched with 4α‐methylsterols and contained the same sterols as the free sterol fraction except for nematodes propagated with 7‐dehydrocholesterol, where no dietary sterol was found in the ester fraction.P. redivivus is capable of reducing the Δ5‐bond, C−24 dealkylation and methylating the sterol nucleus at C−4.
Dietary saturated fat level alters the competition between α‐linolenic and linoleic acid
Authors: Garg M. L. , Wierzbicki A. A. , Thomson A. B. R. , Clandinin M. T. 
Published: November 2006

AbstractMale weanling rats were fed semi‐synthetic diets high in saturated fat (beef tallow) vs high in linoleic acid (safflower oil) with or without high levels of α‐linolenic acid (linseed oil) for a period of 28 days. The effect of feeding these diets on cholesterol content and fatty acid composition of serum and liver lipids was examined. Feeding linseed oil with beef tallow or safflower oil had no significant effect on serum levels of cholesterol. Serum cholesterol concentration was higher in animals fed the safflower oil diet than in animals fed the beef tallow diet without linseed oil. Feeding linseed oil lowered the cholesterol content in liver tissue for all dietary treatments tested. Consumption of linseed oil reduced the arachidonic acid content with concomitant increase in linoleic acid in serum and liver lipid fractions only when fed in combination with beef tallow, but not when fed with safflower oil. Similarly, ω3 fatty acids (18∶3ω3, 20∶5ω3, 22∶5ω3, 22∶6ω3) replaced ω6 fatty acids (20∶4ω6, 22∶4ω6) in serum and liver lipid fractions to a greater extent when linseed oil was fed with beef tallow than with safflower oil. The results suggest that the dietary ratio of linoleic acid to saturated fatty acids or of 18∶3ω3 to 18∶2ω6 may be important to determine the cholesterol and arachidonic acid lowering effect of dietary α‐linolenic acid.
On‐line hydrogenation in GC‐MS analysis of cyclic fatty acid monomers isolated from heated linseed oil
Authors: Le Quéré J. L. , Sémon E. , Lanher B. , Sébédio J. L. 
Published: November 2006

AbstractA simple on‐line hydrogenation method in GC‐MS analysis of unsaturated fatty acid esters is described. Using hydrogen as carrier gas, hydrogenation takes place in a capillary reactor connected to the outlet of the analytical column in the oven of the gas chromatograph. The reactor is a fused silica tube (60 cm×0.32 mm i.d.) coated with palladium acetylacetonate. Selective hydrogenation of olefinic bonds is achieved after a normal chromatographic run. Structural information (carbon‐skeleton, double bond equivalents) can thus be deduced, and structural correlations between the saturated and unsaturated components can be obtained. Structures of cyclic fatty acid esters isolated from heated linseed oil were elucidated using this simple method which was found very useful for structural investigations on unsaturated compounds by GC‐MS.
The effect of dietary fish oil on muscle and adipose tissue lipoprotein lipase
Authors: Herzberg Gene R. , Rogerson Maria 
Published: November 2006

AbstractThe activity of lipoprotein lipase (LPL) in the adipose tissue and skeletal muscle of rats fed glucose‐ or fructose‐based diets containing fish oil, corn oil or tallow was examined. In addition, heart LPL activity was measured in rats fed a glucose‐based diet containing either corn oil or fish oil. Adipose tissue LPL activity was unaffected by dietary fat. In both heart and skeletal muscle, LPL activity was higher in rats fed the fish oil diet. These results suggest that increased removal of triglyceride by muscle may contribute to the blood triglyceride lowering effect of dietary fish oil.
Isolation and characterization of ganglioside 9‐O‐acetyl‐GD3 from bovine buttermilk
Authors: Bonafede Daniela M. , Macala Lawrence J. , Costantine‐Paton Martha , Yu Robert K. 
Published: November 2006

AbstractBovine buttermilk contains a unique ganglioside, 9‐O‐acetyl‐GD3. In order to isolate large quantities of this ganglioside, a simplified isolation scheme which consists of several ion‐exchange and silica gel column chromatographic procedures was devised. The isolated 9‐O‐acetyl‐GD3 was characterized on the basis of its thin‐layer chromatographic behavior, its immunoreactivity with a specific monoclonal antibody, JONES, and by conversion to authentic GD3 by mild base treatment.
Lipid characteristics of RSV‐transformed Balb/c 3T3 cell lines with different spontaneous metastatic potentials
Authors: Calorini Lido , Fallani Anna , Tombaccini Donatella , Barletta Emanuela , Mugnai Gabriele , Di Renzo Maria F. , Comoglio Paolo M. , Ruggieri Salvatore 
Published: November 2006

AbstractTo determine whether a metastatic phenotype may be corelated with a characteristic lipid pattern, we compared the lipid composition of low metastasizing Balb/c 3T3 cells transformed by the B77 strain of Rous sarcoma virus (B77‐3T3 cells) with that of a subclone isolated by growth in 0.6% agar, the B77‐AA6 cells, which exhibit a high capacity for spontaneous metastasis. B77‐3T3 cells revealed characteristics in their lipid composition common to other systems of transformed cells, i.e., an accumulation of ether‐linked lipids, a reduction of the more complex gangliosides, an increase of oleic acid (18∶1) and a decrease of arachidonic (20∶4) and C22 polyunsaturated fatty acids in phospholipids. High metastatic B77‐AA6 cells showed: a) an even more marked decrease of complex gangliosides; b) a more pronounced increase of 18∶1 and decrease of 20∶4 and 22 polyunsaturated fatty acids in certain phospholipid classes; and c) a higher percentage of alkyl‐acyl subfractions in both phosphatidylcholine and phosphatidylethanolamine than B77‐3T3 cells.Comparing the data for other systems of metastatic cells with those of lipid studies of spontaneously metastasizing B77‐AA6 cell system leads us to conclude that the metastatic phenotype is characterized by a change in ether‐linked lipids, rather than in fatty acids.
An evaluation of NBD‐phospholipids as substrates for the measurement of phospholipase and lipase activities
Authors: Moreau Robert A. 
Published: November 2006

AbstractBecause most of the existing assays of phospholipase activity are quite laborious, the use of 1‐acyl‐2‐[6‐(7‐nitro‐1,3‐benzoxadiazol‐4‐yl)amino]caproyl labeled phospholipids (NBD phospholipids) was investigated to determine whether they could be used as substrates in the routine assay of various phospholipases and lipases. NBD‐labeled analogues of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, and phosphatidic acid were evaluated. There was about a 50‐fold increase in fluorescence upon hydrolysis of the NBD hexanoic acid from the NBD phospholipid, confirming an earlier report. This change in fluorescence was constant over the normal physiological pH range (pH 5–9). Detergents and bovine serum albumin interfered with the assay in a concentration dependent manner. An increase in fluorescence and a concomitant increase in NBD hexanoic acid was detected with the two phospholipase A2 enzymes. Although a change in fluorescence was detected with a phospholipase C, careful evaluation revealed that the rate of increase in fluorescence was not proportional to the rate of production of diacylglycerol product. Neither of the two phospholipase D enzymes which were tested were able to cause an increase in fluorescence when incubated with NBD phospholipids. A small increase in fluorescence was detected with each of the four lipases. Of the five NBD lipids tested, the highest rates of hydrolysis were consistently obtained with NBD‐phosphatidylglycerol followed by NBD‐phosphatidylcholine.
Activation of rat liver cholesterol ester hydrolase by cAMP‐dependent protein kinase and protein kinase C
Authors: Ghosh Shobha , Grogan W. McLean 
Published: November 2006

AbstractShort term regulation of hepatic cholesterol ester hydrolase by reversible phosphorylation is described. Two different kinase systems seem to be involved in this regulation. The addition of ATP, cyclic AMP and Mg2+ to rat liver 104,000× g supernatant (S104) produced a 100–140% increase in cholesterol ester hydrolase activity. This stimulation was abolished when protein kinase inhibitor was added prior to the addition of ATP, cyclic AMP and Mg2+. Cholesterol ester hydrolase activity was also stimulated when calcium ions, phosphatidylserine, and diolein were added to S104 along with ATP and Mg2+. Diolein in this reaction could be substituted by phorbol 12‐myristate 13‐acetate. Preincubation of S104 with alkaline phosphatase resulted in a deactivation of cholesterol ester hydrolase. The addition of increasing concentrations of Mg2+ to S104 produced increasing inhibition of cholesterol ester hydrolase activity, and this effect was blocked by NaF.It is suggested that rat liver cholesterol ester hydrolase is activated by cyclic AMP dependent protein kinase and protein kinase C. Deactivation is accomplished by dephosphorylation catalyzed by a phosphoprotein phosphatase, dependent on Mg2+.
α‐Oxidation of α‐hydroxyfatty acids in rat brain. Possible involvement of an α‐peroxylactone
Authors: Salim‐Hanna Marta , Campa Ana , Cilento Giuseppe 
Published: November 2006

AbstractCombine—but not individual—microsomal and supernatant fractions obtained from rat brains not only consume oxygen but also provoke emission from added chlorophyll. These results are consistent with literature data (Levis and Mead,J. Biol. Chem. 239, 77 [1964]) for trapping of radioactive14CO2 following addition of α‐hydroxy‐[1‐14C]stearic acid. The most plausible explanation for emission is the interaction of chlorophyll with an α‐peroxylactone. An intermediary α‐peroxylactone in α‐oxidation is consistent with other available data (Salim‐Hanna, Campa and Cilento,Photochem. Photobiol. 45, 849 [1987]; Campa, Salim‐Hanna and Cilento,Photochem. Photobiol. 49, 349 [1989]) and, on chemical grounds, provides a feasible route to the final products.
Incorporation of arachidonic, dihomogamma linolenic and eicosapentaenoic acids into cultured V79 cells
Authors: Weithmann Klaus U. , Peterson Hazel , Sevanian Alex 
Published: November 2006

AbstractThe uptake and distribution of three common dietary polyunsaturated fatty acids was studied using Chinese hamster lung fibroblasts (V79 cells). Treatment of V79 cells with arachidonic (20∶4), eicosapentaenoic (20∶5) and dihomogammalinolenic (20.3) acids for 24 hr produced a marked uptake of 20∶3 and 20∶4, both of which were assimilated to a considerably greater degree than 20∶5. All polyunsaturated fatty acids were incorporated primarily into phospholipids; however, there were considerable differences in their distribution into individual phospholipid species. Although 20∶4 was incorporated primarily into phosphatidylcholine, 20∶3 entered largely into phosphatidylethanolamine and phosphatidylglycerol, and 20∶5 was distributed about equally between phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol. A marked conversion of 20∶3 to 20∶4 was found after 24 hr and, in several phospholipids, there was as much derived‐radiolabeled 20∶4 as there was radiolabeled 20∶3. There was little evidence of 20∶4 and 20∶5 metabolism. V79 cells undergo substantial changes in phospholipid fatty acid composition following supplementation with these polyunsaturated fatty acids; however, these fatty acids are assimilated to different degrees and their distribution among cellular phospholipids is distinct, suggesting incorporation via independent mechanisms.
Effects of fish oil, corn oil and lard diets on lipid peroxidation status and glutathione peroxidase activities in rat heart
Authors: Nalbone Gilles , Leonardi Jeannie , Termine Elise , Portugal Henri , Lechene Paulette , Pauli Anne‐Marie , Lafonf Huguette 
Published: November 2006

AbstractIn this study, we investigated the effect of various types of fats on heart lipid peroxidation status and on blood lipid parameters. Rats were fed either a low‐fat diet (2.2% lard plus 2.2% corn oil), a corn oil diet (17%), a salmon oil diet (12.5%) supplemented with 4.5% corn oil, or a lard diet (15%) supplemented with 2% corn oil. All diets were supplemented with 1% cholesterol. Rats were fed for eight weeks. When compared with the low‐fat diet, the salmon oil‐diet intake resulted in a lower blood cholesterol, triglyceride and phospholipid concentrations (−50, −56 and −30%, respectively). Corn oil only tended to lower blood lipids; this decrease was significant for triglycerides only (−40%). The hypocholesterolemic effect of salmon oil diet is even more pronounced, if blood cholesterol values are compared with those of rats fed the lard diet. Heart lipid composition was not affected by dietary manipulations. Fatty acid composition of cardiac phosphatidylcholines and phosphatidylethanolamines, however, were altered by high‐fat diets. In phosphatidylcholine, salmon oil induced a twelvefold decrease in the n−6/n−3 ratio and a 26% increase in the unsaturation index. For phosphatidylethanolamine, the n−6/n−3 ratio decreased 7.7‐fold and the unsaturation index increased by 13%. A 50% decrease of the n−6/n−3 ratio was observed in animals fed the lard diet. Ultramicroscopic examination of ventricles revealed that those of the salmon oil group significantly accumulated lipofuscin‐like or ceroid material, whereas this accumulation was barely detectable in hearts of the other groups. Seleniumdependent glutathione peroxidase activity tended to be the highest in hearts of rats fed the salmon oil diet; this increase is significant (+36% and +54% for total and specific activities, respectively), if values are compared with those of the rats fed the lard diet. Liver glutathione peroxidase and heart glutathione S‐transferases activities remained unchanged. These results indicate that fish oil did not lower the selenium involved in glutathione peroxidase activity. This rules out that a deficiency in this enzyme was at the origin of heart lipofuscinosis. Also, it is concluded that the n−6/n−3 ratio of the diet is likely more determinant in the alteration of heart lipid peroxidation status than is the polyunsaturated/saturated ratio.
Isolation and identification of acetyl‐CoA carboxylase from rainbow trout (Salmo gairdneri) liver
Authors: McKim J. M. , Schaup H. W. , Marien K. , Selivonchick D. P. 
Published: November 2006

AbstractAcetyl‐CoA carboxylase is the pivotal enzyme in the de novo synthesis of fatty acids and is the only carboxylase with a biotin‐containing subunit greater than 200,000 daltons. The biotin moiety is covalently linked to the active site and has a high affinity (Kd=10−15 M) for the protein avidin. This relationship has been used in previous studies to identify acetyl‐CoA carboxylase isolated from mammalian species. However, acetyl‐CoA carboxylase has not been isolated and characterized in a poikilothermic species such as the rainbow trout. The present study describes the isolation and identification of acetyl‐CoA carboxylase in the cytosol of rainbow trout (Salmo gairdneri) liver. The enzyme was isolated using two distinct procedures—polyethylene glycol precipitation and avidin‐Sepharose affinity chromatography. Identification of the isolated protein as acetyl‐CoA carboxylase was made by the following: (1) sodium dodecyl sulfate‐polyacrylamide gel electrophoresis; (2) avidin binding; (3) in vivo labeling with [14C]biotin; and (4) acetyl‐CoA carboxylase‐specific activity. The subunit molecular weight of the major protein was 230,000 daltons ±3.3%. This protein was shown to bind avidin (Mr=16,600) prior to sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, indicating the presence of biotin. In addition, protein isolated from fish that had previously received intraperitoneal injections of [14C]biotin, showed the majority of radioactivity associated with the 230,000 dalton protein. The polyethylene glycol precipitation yielded 200 μg protein (4.4 μg/g liver), with a specific activity of 5 nmol malonyl‐CoA/min/mg protein, whereas avidin affinity chromatography yielded 1.75±1.1 mg protein (9.0 μg/g liver), with a specific activity of 1.37±0.18 μmol malonyl‐CoA/min/mg protein. The enzyme was citrate dependent showing maximum activity between 10 and 20 mM. Acetyl‐CoA carboxylase‐specific activity decreased by 50% in the presence of 0.2 M NaCl. These findings suggest that the major protein (Mr=230,000) purified from rainbow trout liver is acetyl‐CoA carboxylase with enzyme characteristics comparable to mammalian acetyl‐CoA carboxylase.
Reaction products of α‐tocopherol with a free radical initiator, 2,2′‐azobis(2,4‐dimethylvaleronitrile)
Authors: Yamauchi Roy , Matsui Tomoatsu , Satake Yasuko , Kato Koji , Ueno Yoshimitsu 
Published: November 2006

Abstractα‐Tocopherol wss reacted with an alkylperoxyl radical at 37°C in ethanol. 2,2′‐Azobis(2,4‐dimethylvaleronitrile) was used to generate the alkylperoxyl radicals. The reaction products of α‐tocopherol were isolated by reverse‐phase and normal‐phase high performance liquid chromatography, and their structures were characterized by infrared, ultraviolet,1H and13C nuclear magnetic resonances and mass spectrometry. They were 8aS‐hydroperoxy‐α‐tocopherone, 8aR‐hydroperoxy‐α‐tocopherone, a mixure of 7,8‐epoxy‐8aS‐ethoxy‐α‐tocopherone, and 7,8‐epoxy‐8aR‐ethoxy‐α‐tocopherone, 8aS‐(1R‐cyano‐1,3‐dimethyl)butylperoxy‐α‐tocopherone, 8aS‐(1S‐cyano‐1,3‐dimethyl)butylperoxy‐α‐tocopherone, a mixture of 8aR‐(1S‐cyano‐1,3‐dimethyl)butylperoxy‐α‐tocopherone and 8aR‐(1S‐cyano‐1,3‐dimethyl)butylperoxy‐α‐tocopherone, 4aR,5S‐epoxy‐8aS‐ethoxy‐α‐tocopherone, 4aS,5R‐epoxy‐8aS‐ethoxy‐α‐tocopherone and 4aR,5S‐epoxy‐8aR‐ethoxy‐α‐tocopherone.
The distribution of lipids and sterols in cell types from the marine spongePseudaxinyssa sp
Authors: Zimmerman Mary P. , Thomas Frances C. , Thompson Janice E. , Djerassi Carl , Streiner Heidi , Evans Elizabeth , Murphy Peter T. 
Published: November 2006

AbstractThe spongePseudaxinyssa sp., unique in sterol and fatty acid composition, was cellularly dissected into fractions enriched in each of the major cell types present in the sponge: microbial symbionts (cyanobacteria), small sponge cells (pinacocytes and choanocytes), and large sponge cells (archeocytes and cyanophytes). Three phototrophic microbial symbionts were also isolated from the cell fractions and grown in culture. An unsymmetrical distribution of fatty acids and sterols was observed for the sponge cells: small cells contained larger quantities of long chain fatty acids (> C24) and smaller quantities of sterols than were present in the larger sponge cells. Moreover, the rare sterols 24‐isopropylcholesterol predominated in the smaller sponge cells, whereas its 22‐dehydro analog predominated in the larger sponge cells. Long chain fatty acids and sterols were not detected in the cultured microbial symbionts. This constitutes the first report of lipid variability according to cell type for this most primitive group of Metazoa.