bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of brain long‐chain acylcarnitines during cerebral ischemia
Authors: Deutsch J. , Kalderon B. , Purdon A. D. , Rapoport S. I. 
Published: November 2006

AbstractConcentration and distribution of long‐chain acylcarnitines in control microwaved and ischemic (decapitated) rat brain were measured by electrospray ionization tandem mass spectrometry. The total acylcarnitine concentration from control rat brains equaled 7–8 nmol/g wet weight brain, about one‐fourth the total concentration of long‐chain acyl‐CoA, indicating a small role in buffering the total acyl‐CoA pool concentration. Furthermore, acylcarnitine did not differ between ischemic and control rat brain with regard to total concentration or concentrations of molecular species of acylcarnitine. Therefore, the size of the acylcarnitine pool in brain is not affected by the dramatic increase in unesterified fatty acids (∼4×) that occurs in ischemia.
Follow‐up of the Δ4 to Δ16 trans‐18∶1 isomer profile and content in French processed foods containing partially hydrogenated vegetable oils during the period 1995–1999. Analytical and nutritional implications
Authors: Wolff Robert L. , Combe Nicole A. , Destaillats Frédéric , Boué Carole , Precht Dietz , Molkentin Joachim , Entressangles Bernard 
Published: November 2006

AbstractA survey of the total content of trans‐18∶1 acids and their detailed profile in French food lipids was conducted in 1995–1996, and 1999. For this purpose, 37 food items were chosen from their label indicating the presence of partially hydrogenated vegetable oils (PHVO) in their ingredients. The content as well as the detailed profile of these isomers was established by a combination of argentation thin‐layer chromatography and gas‐liquid chromatography (GLC) on long polar capillary columns. With regard to the mean trans‐18∶1 acid contents of extracted PHVO, a significant decrease was observed between the two periods, i.e., from 26.9 to 11.8% of total fatty acids. However, only minor differences were noted in the mean relative distribution profiles of individual trans‐18∶1 isomers with ethylenic bonds between positions Δ4 and Δ16 for the two periods. The predominant isomer was Δ9–18∶1 (elaidic) acid, in the wide range 15.2–46.1% (mean, 27.9±7.2%) of total trans‐18∶1 acids, with the Δ10 isomer ranked second, with a mean of 21.3% (range, 11.6 to 27.4%). The content of the unresolved Δ6 to Δ8 isomer group was higher than the Δ11 isomer (vaccenic acid), representing on average 17.5 and 13.3%, respectively. Other isomers Δ4, Δ5, Δ12, Δ13/Δ14, Δ15, and Δ16, were less than 10% each: 1.0, 1.6, 7.4, 7.1, 1.8, and 1.0%, respectively. However, considering individual food items, it was noted that none of the extracted PHVO were identical to one another, indicating a considerable diversity of such fats available to the food industry. A comparison of data for French foods with similar data recently established for Germany indicates that no gross differences occur in PHVO used by food industries in both countries. Estimates for the absolute mean consumption of individual isomers from ruminant fats and PHVO are made for the French population and compared to similarly reconstructed hypothetical profiles for Germany and North America. Differences occur in the total intake of trans‐18∶1 acids, but most important, in individual trans‐18∶1 isomer intake, with a particular increase of the Δ6–Δ8 to Δ10 isomers with increasing consumption of PHVO. It is inferred from the present and earlier data that direct GLC of fatty acids is a faulty procedure that results (i) in variable underestimates of total trans‐18∶1 acids, (ii) in a loss of information as regards the assessment of individual isomeric trans‐18∶1 acids, and (iii) in the impossibility of comparing data obtained from human tissues if the relative contribution of dietary PHVO and ruminant fats is not known.
Variablity of the intestinal uptake of lipids is genetically determined in mice
Authors: Keelan M. , Hui D. Y. , Wild G. , Clandinin M. T. , Thomson A. B. R. 
Published: November 2006

AbstractThe response of the plasma cholesterol concentration to changes in dietary lipids varies widely in humans and animals. There are variations in the in vivo absorption of cholesterol between different strains of mice. This study was undertaken in three strains of inbred mice to test the hypotheses that: (i) there are strain differences in the in vitro uptake of fatty acids and cholesterol and (ii) the adaptability of the intestine to respond to variations in dietary lipids is genetically determined. An in vitro intestinal ring technique was used to assess the uptake of medium‐ and long‐chain fatty acids and cholesterol into jejunum and ileum of adult DBA/2, C57BL6, and C57L/J mice. The jejunal uptake of cholesterol was similar in C57L/J, DBA/2, or C57BL6 fed ad libitum a low‐fat (5.7% fat, no cholesterol) chow diet. This is in contrast to a previous demonstration that in vivo cholesterol absorption was lower in C57L/J than in the other murine strains. The jejunal uptake of several long‐chain fatty acids was greater in DBA/2 fed for 4 wk the high‐fat (15.8% fat and 1.25% cholesterol) as compared with the low‐fat diet. Furthermore, on the high‐fat diet, the uptake of many long‐chain fatty acids was higher in DBA/2 than in C57BL6 or C57L/J. The differences in cholesterol and fatty acid uptake were not explained by variations in food uptake, body weight gain, or the weight of the intestine. In summary: (i) there are strain differences in the in vitro intestinal uptake of fatty acids but not of cholesterol; (ii) a high‐fat diet enhances the uptake of long‐chain fatty acids in only one of the three strains examined in this study; and (iii) the pattern of strain‐ and diet‐associated alterations in the in vivo absorption of cholesterol differs from the pattern of changes observed in vitro. We speculate that genetic differences in cholesterol and fatty acid uptake are explained by variations in the expression of protein‐mediated components of lipid uptake.
Response of urinary lipophilic aldehydes and related carbonyl compounds to factors that stimulate lipid peroxidation in vivo
Authors: Csallany A. Saari , Kim Song‐Suk , Gallaher Daniel D. 
Published: November 2006

AbstractPeroxidation of lipids results in the formation of a number of aldehydic and other carbonyl‐containing secondary degradation products. The effect of peroxidative stimuli mediated by vitamin E deficiency, a diet high in polyunsaturated fatty acids (containing cod liver oil), and carbon tetrachloride administration on urinary excretion of a number of lipophilic aldehydes and related carbonyl compounds was examined in rats. These secondary lipid peroxidation products were measured as 2,4‐dinitrophenylhydrazine derivatives. All three treatments increased urinary excretion of secondary lipid peroxidation products, although the pattern of excretion of these products varied somewhat among the treatments. Significant increases were found in butanal, hexanal, octanal. butan‐2‐one, pentan‐2‐one, hex‐2‐enal, hepta‐2,4‐dienal, 4‐hydroxyhex‐2‐enal, 4‐hydroxyoct‐2‐enal, 4‐hydroxynon‐2‐enal, and a number of unidentified carbonyl compounds. These results suggest that urinary excretion of these lipophilic secondary lipid peroxidation products is a useful and noninvasive marker of whole‐body lipid peroxidation.
n−3 Fatty acid deficiency decreases phosphatidylserine accumulation selectively in neuronal tissues
Authors: Hamilton Jillonne , Greiner Rebecca , Salem Norman , Kim Hee‐Yong 
Published: November 2006

AbstractWe have previously shown that the docosahexaenoate (22∶6n−3) status in membrane phospholipids influences the biosynthesis and accumulation of phosphatidylserine (PS) in brain microsomes and C6 glioma cells. In the present study, we investigated whether the observed effect of membrane docosahexaenoic acid status on PS accumulation is universal or occurs specifically in neuronal tissues. We observed that rat brain cortex, brain mitochondria, and olfactory bulb, where 22∶6n−3 is highly concentrated, contain significantly higher levels of PS in comparison to liver and adrenal, where 22∶6n−3 is a rather minor component. Phospholipid molecular species analysis revealed that in brain cortex, mitochondria, and olfactory bulb 18∶0,22∶6n−3 was the most abundant species representing 45–65% of total PS. In nonneuronal tissues such as liver and adrenal, 18∶0,20∶4n−6 was the major PS species. Dietary depletion of n−3 fatty acids during prenatal and postnatal developmental periods decreased the brain 22∶6n−3 content by more than 80%, with a concomitant increase in 22∶5n−6 in all tissues. Under these conditions, an approximately 30–35% reduction in total PS in rat brain cortex, brain mitochondria, and olfactory bulb was observed, while PS levels in liver and adrenal were unchanged. The observed reduction of PS content in neuronal membranes appears to be due to a dramatic reduction of 18∶0,22∶6n−3‐PS without complete replacement by 18∶0,22∶5n−6‐PS. These results establish that variations in membrane 22∶6n−3 fatty acid composition have a profound influence on PS accumulation in neuronal tissues where 22∶6n−3 is abundant. These data have implications in neuronal signaling events where PS is believed to play an important role.
The questionable role of a microsomal °8 acyl‐CoA‐dependent desaturase in the biosynthesis of polyunsaturated fatty acids
Authors: Chen Qi , Yin Feng Qin , Sprecher Howard 
Published: November 2006

AbstractSeveral experimental approaches were used to determine whether rat liver and testes express an acyl‐CoA‐dependent δ8 desaturase. When [1‐14C]5, 11, 14‐eicosatrienoic acid was injected via the tail vein, or directly into testes, it was incorporated into liver and testes phospholipids, but it was not metabolized to other labeled fatty acids. When [1‐14C]11, 14‐eicosadienoic acid was injected, via the tail vein or directly into testes, or incubated with microsomes from both tissues, it was only metabolized to 5,11, 14‐eicosatrienoic acid. When ethyl 5,5,11,11,14,14‐d6‐5,11,14‐eicosatrienoate was fed to rats maintained on a diet devoid of fat, it primarily replaced esteri‐fied 5,8,11‐eicosatrienoic acid, but not arachidonic acid. No labeled linoleate or arachidonate were detected. Dietary ethyl linoleate and ethyl 19,19,20,20‐d4‐1,2‐13C‐11,14‐eicosadienoate were about equally effective as precursors of esterified arachidonate. The doubly labeled 11,14‐eicosadienoate was metabolized primarily by conversion to 17,17,18,18‐d4‐9,12‐ocatdeca‐dienoic acid, followed by its conversion to yield esterified arachidonate, with a mass four units greater than endogenous arachidonate. In addition, the doubly labeled substrate gave rise to a small amount of arachidonate, six mass units greater than endogenous arachidonate. No evidence was obtained, with the radiolabeled substrates, for the presence of a δ8 desaturase. However, the presence of an ion, six mass units greater than endogenous arachidonate when doubly labeled 11, 14‐eicosa‐dienoate was fed, suggests that a small amount of the substrate may have been metabolized by the sequential use of δ8 and δ5 desaturases.
Conjugated linoleic acid suppresses triglyceride accumulation and induces apoptosis in 3T3‐L1 preadipocytes
Authors: Evans M. , Geigerman C. , Cook J. , Curtis L. , Kuebler B. , McIntosh M. 
Published: November 2006

AbstractFour sets of experiments were conducted to examine the influence of conjugated linoleic acid (CLA) isomers during proliferation and differentiation of cultures of 3T3‐L1 preadipocytes using physiological culturing conditions. Cultures treated with either albumin [bovine serum albumin (BSA) vehicle] or linoleic acid (LA) served as controls. For the proliferation study (Expt. 1), cells were cultured in media containing a crude mixture of CLA isomers or pure LA at 0, 10, 50, or 200 μM for 4 d. Preadipocyte proliferation (cell number, 3H‐thymidine incorporation into DNA) decreased as the level of CLA increased in the cultures. In contrast, LA had no impact on DNA synthesis. In Experiment 2a, postconfluent cultures were grown in media containing a crude mixture of CLA isomers or LA at 0, 10, 50, or 200 μM for the next 6 d. Postconfluent cultures supplemented with 50–200 μM CLA had less triglyceride (TG) and were smaller in size than cultures supplemented with similar amounts of LA. In Experiment 2b, postconfluent cultures supplemented with 200 μM of a crude mixture of CLA isomers or LA were harvested on days 1, 3, 6, or 9. Differences in TG content of cultures supplemented with 200 μM CLA compared to control and LA‐supplemented cultures became apparent after 3 d of culture. Experiments 3a and 3b examined whether the fatty acid vehicle (BSA vs. ethanol) or the vitamin E status (±0.2 mM α‐tocopherol) of the cultures altered CLA's impact on preadipocyte TG content. In Experiment 3a, ethanol‐treated cultures had more TG than non‐ethanol‐treated cultures regardless of the fatty acid treatment. In Experiment 3b, cultures treated with 100 μM of either a crude mixture of CLA or the trans‐10, cis‐12 CLA isomer without supplemental vitamin E for 6 d had less TG than CLA‐treated cultures containing vitamin E. In Experiment 4, postconfluent cultures were grown in media containing 100 μM LA or either a crude mixture of CLA isomers or the trans‐10, cis‐12 CLA isomer for 24–96 h to assess CLA's influence on the cell cycle and indices of apoptosis. Cultures treated with 100 μM CLA for 24–96 h had more apoptotic cells than BSA‐ or LA‐treated cultures. Furthermore, cultures treated for 48 h with CLA had fewer cells in the S‐phase than control cultures. The effects of the trans‐10,cis‐12 CLA isomer were more pronounced than those of the crude mixture of CLA isomers. These data suggest that CLA may exert its antiobesity effects by inhibiting proliferation, attenuating TG content, and/or inducing apoptosis in (pre)adipocytes.
Kinetic properties of Penicillium cyclopium lipases studied with vinyl esters
Authors: Chahinian Henri , Nini Lylia , Boitard Elisabeth , Dubès Jean‐Paul , Sarda Louis , Comeau Louis‐Claude 
Published: November 2006

AbstractPenicillium cyclopium produces two lipases with different substrate specificities. Lipase I is predominantly active on triacylglycerols whereas lipase II hydrolyzes mono‐ and diacylglycerols but not triacylglycerols. In this study, we compared the kinetic properties of P. cyclopium lipases and human pancreatic lipase, a classical triacylglycerol lipase, by using vinyl esters as substrates. Results indicate that P. cyclopium lipases I and II and human pancreatic lipase hydrolyze solutions of vinyl propionate or vinyl butyrate at high relative rates compared with emulsions of the same esters, although, in all cases, maximal activity is reached in the presence of emulsified particles, at substrate concentrations above the solubility limit. It appears that partially water‐soluble short‐chain vinyl esters are suitable substrates for comparing the activity of lipolytic enzymes of different origin and specificity toward esters in solution and in emulsion.
Current methods for the identification and quantitation of ceramides: An overview
Authors: Cremesti Aida E. , Fischl Anthony S. 
Published: November 2006

AbstractCeramides are key compounds in the metabolism of sphingolipids and are emerging as important second messengers for various cellular processes including cell cycle arrest, differentiation, senescence, apoptosis, and others. Because of their important biological functions, exact analysis of their molecular species and concentrations is crucial for elucidating their function and metabolism. Toward this goal, several methods have been developed for the identification and quantitation of cellular ceramide levels. Methods have been developed utilizing thin‐layer or high‐performance liquid chromatography. Mass spectrometry also has become increasingly utilized. The Escherichia coli diacylglycerol kinase assay is one of the most frequently used techniques for ceramide quantitation. This review presents a current summary of methods used for the identification and quantitation of ceramides.
Autoxidation of methyl linoleate: Identification of the bis‐allylic 11‐hydroperoxide
Authors: Brash Alan R. 
Published: November 2006

AbstractBased on the understanding of lipid peroxidation as a free radical chain reaction, over 50 yr ago the three primary products of linoleic acid autoxidation were predicted to be the 9‐, 11‐, and 13‐hydroperoxides. The 9‐ and 13‐hydroperoxides were found at the time, but formation of 11‐hydroperoxylinoleate or any other bis‐allylic fatty acid hydroperoxide has not been reported hetetofore as a product of lipid peroxidation reactions. In vitamin E‐controlled autoxidation of methyl linoleate, the 11‐hydroperoxy derivative was identified as the next most prominent primary peroxidation product after the 9‐and 13‐hydroperoxides. It was present in approximately 5–10% of the abundance of the 9‐ or 13‐hydroperoxide. The structures of 11‐hydroperoxylinoleate and its 11‐hydroxy derivative were established by high‐pressure liquid chromatography, ultraviolet spectroscopy, gas chromatography‐mass spectroscopy, and 1H nuclear magnetic resonance spectroscopy. The 11‐hydroperoxide was not detectable in the absence of α‐tocopherol, indicating that efficient trapping of the 11‐peroxyl radical as the hydroperoxide is critical to permitting its accumulation.
Formation of 8‐oxo‐2′‐deoxyguanosine in the DNA of human diploid fibroblasts by treatment with linoleic acid hydroperoxide and ferric ion
Authors: Kaneko Takao , Tahara Shoichi 
Published: November 2006

AbstractLipid peroxides are suggested to be related to the occurrence of a variety of diseases including cancer and atherosclerosis. We examined whether lipid peroxides cause oxidative damage to DNA in intact cells. Linoleic acid hydroperoxide (LOOH) and ferric chloride were used at concentrations at which separate treatment had no effect on the formation of 8‐oxo‐2′‐deoxyguanosine (8‐oxodG) in DNA or the survival rate of cultured human diploid fibroblasts, TIG‐7. The amount of 8‐oxodG in the cellular DNA increased significantly when TIG‐7 cells were treated concurrently with LOOH and ferric chloride. In a LOOH concentration‐dependent manner 8‐oxodG was formed. However, no significant induction of the activities of superoxide dismutases, catalase, or glutathione peroxidase was observed under these conditions. The formation of 8‐oxodG by lipid hydroperoxides seems to be due to the generation of reactive species other than superoxide radicals and hydrogen peroxide. These results indicate that some species formed during the reaction of lipid hydroperoxides with ferric ion can cause oxidative damage to DNA.
Lipid peroxidation as determined by plasma isoprostanes is related to disease severity in mild asthma
Authors: Wood Lisa G. , Fitzgerald Dominic A. , Gibson Peter C. , Cooper David M. , Garg Manohar L. 
Published: November 2006

AbstractOxidative stress is believed to play an important role in the pathophysiology of asthma. Recently discovered F2‐isoprostanes, of which 8‐iso‐PGF2αis the most well‐known isomer, have emerged as the most reliable marker ofin vivooxidative stress. The aim of this study was to examine 8‐iso‐PGF2αas a biomarker of oxidative stress in mild asthma in relation to endogenous and dietary antioxidant protection. Total (free and esterified) plasma 8‐iso‐PGF2α, plasma dietary antioxidants (vitamins E and C,β‐carotene, Zn, and Se), and erythrocyte antioxidant enzyme activities (glutathione peroxidase and superoxide dismutase) were measured in 15 mild asthmatics and 15 age‐and sex‐matched controls. Total plasma 8‐iso‐PGF2αlevels [median (quartile 1‐quartile 3)] were significantly increased in the sthmatics [213 pg/mL (122–455) vs. 139 pg/mL (109–174),P=0.042]. The 8‐iso‐PGF2αlevels were found to be associated with clinical asthma severity (P=0.044) and inhaled corticosteroid use (P=0.027) in asthmatics. No differences were observed in the plasma dietary antioxidant vitamins. The asthmatics had significantly lower plasma levels of Zn (P=0.027) and Se (P=0.006). Plasma Se correlated negatively with 8‐iso‐PGF2α(r=−0.725,P=0.002). No differences between the groups were observed for glutathione peroxidase or superoxide dismutase, however, superoxide dismutase activity was negatively associated with asthma severity (P=0.042). In conclusion, oxidative stress is increased in mild asthmatics, as reflected by increased plasma levels of 8‐iso‐PGF2αand a deficiency in plasma Zn and Se. The isoprostane 8‐iso‐PGF2αmay provide a useful tool in intervention studies aimed at improving clinical status in asthma.
Calcium deficiency modifies polyunsaturated fatty acid metabolism in growing rats
Authors: Marra Carlos A. , de Alaniz María J. T. 
Published: November 2006

AbstractFatty acid desaturase activities were determined in liver microsomes from calcium‐deficient rats and compared to calcium‐sufficient ones. The calcium‐deprived diet (0.5 g/kg) administered for 60 d caused a 30% inhibition in the Δ5 desaturase activity and a 45–55% decrease in Δ6 and Δ9, respectively, facts that cannot be attributed to a reduction in food intake. In vitro addition of calcium, ethyleneglycol‐bis(β‐aminoethyl ether)N,N‐tetraacetic acid, and/or cytosol fractions from control or calcium‐deficient rats to microsomes from both groups of animals indicates that the reduced desaturase capacities would be the consequence of an indirect effect of calcium deprivation. The present work shows that the reduced unsaturated fatty acid biosynthesis might be the result of modifications in the physicochemical properties of microsomal membranes. Such changes could also be derived from the inhibition of phospholipase A2 activity induced by calcium deficiency.
The effect of low α‐linolenic acid diet on glycerophospholipid molecular species in guinea pig brain
Authors: Kurvinen J. ‐P. , Kuksis A. , Sinclair A. J. , Abedin L. , Kallio H. 
Published: November 2006

AbstractThe changes in guinea pig brain (cerebrum) glycerophospholipid molecular species resulting from a low α‐linolenic acid (ALA) diet are described. Two groups of six guinea pigs were raised from birth to 16 wk of age on either an n‐3 deficient diet containing 0.01 g ALA/100 g diet or n‐3 sufficient diet containing 0.71 g AlA/100 g diet. Molecular species of diradyl glycerophosphoethanolamine. (GroPEtn), glycerophosphocholine, glycerophosphoserine, and glycerophosphoinositol were analyzed by high‐performance liquid chromatography with on‐line electrospray ionization mass spectrometry (HPLC/ESI/MS). Alkenylacyl GroPEtn species were determined by comparing spectra before and after mild acid treatment while diacyl‐ and alkylacyl species were distinguished by HPLC/ ESI/MS. The proportions of phospholipid classes and of the diradyl GroPEtn subclasses were not altered by diet changes. The main polyunsaturated molecular species of diradyl GroPEtn subclasses and of phosphatidylcholine and phosphatidylserine (PtdSer) contained 16∶0, 18∶0, or 18∶1 in combination with docosahexaenoic acid (DHA, 22∶6n‐3), docosapentaenoic (DPA, 22∶5n‐6), or arachidonic acid (ARA, 20∶4n‐6). A significant proportion of DPA containing species were present in both diet groups, but in n‐3 fatty acid deficiency, the proportion of DPA increased and DHA was primarily replaced by DPA. The combined value of main DHA and DPA containing species in the n‐3 deficient group ranged from 91‐111% when compared with the n‐3 sufficient group, indicating a nearly quantitative replacement. The n‐3 fatty acid deficiency did not lower the content of ARA containing molecular species of PtdSer of the guinea pig brain as reported previously for the rat brain. The molecular species of phosphatidylinositol were not altered by n‐3 fatty acid deficiency. The present data show that the main consequence of a low ALA diet is the preferential replacement of DHA‐containing molecular species by DPA‐containing molecular species in alkenylacyl‐ and diacyl GroPEtn and PtdSer of guinea pig brain.