bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipids in human milk
Authors: Jensen Robert G. 
Published: November 2006

AbstractI have reviewed recent (March 1995–December 1997) papers on human milk lipids including many on fatty acid (FA) composition. The effects of maternal diets on the profiles are apparent. However, more data on the composition of milk lipids are needed. It is noteworthy that so few papers on milk FA composition have reported analyses using high‐resolution gas‐liquid chromatography columns. Two of these were on milk from women in North America. The diets in North America are varied and the number of analyses few. We do not have a reliable data base showing the ranges of biologically important acids. Except for the gangliosides, few new data on the other lipids appeared during this period.
Cerebrospinal fluid lipoproteins are more vulnerable to oxidation in Alzheimer's disease and are neurotoxic when oxidized ex vivo
Authors: Bassett Casey N. , Neely M. Diana , Sidell Kathrin R. , Markesbery William R. , Switt Larry L. , Montine Thomas J. 
Published: November 2006

AbstractBrain regional oxidative damage is thought to be a central mechanism in the pathogenesis of Alzheimer's disease (AD). Recent studies of cerebrospinal fluid (CSF) have suggested that increased lipid peroxidation of CSF and CSF lipoproteins also may occur in AD patients. In the present study, we determined the susceptibility of human CSF to ex vivo lipid peroxidation and tested the hypothesis that oxidized CSF lipoproteins may be neurotoxic. Whole CSF or a CSF lipoprotein fraction (d<1.210 g/mL) was oxidized with 2,2′‐azobis(2‐amidino‐propane)dihydrochloride (AAPH), a hydrophilic free‐radical generator. Kinetics of CSF lipid peroxidation were followed by a standard fluorescence product accumulation assay. Oxidation of AD CSF yielded significantly shorter fluorescent lag times than controls, indicating reduced antioxidant capacity. Electrophoretic mobilities of CSF apolipoproteins were specifically reduced upon oxidation of CSF with AAPH, suggesting that lipoproteins are primary targets of CSF lipid peroxidation. Cultured neuronal cells were exposed to physiological concentrations of isolated CSF lipoproteins oxidized with increasing concentrations of AAPH; the resulting neurotoxicity showed a significant linear AAPH concentration‐response relationship. These results suggest that oxidized CSF lipoproteins may contribute to the pathogenesis of neurodegeneration in AD.
Effect of eicosapentaenoic acid on the proliferation and incidence of apoptosis in the colorectal cell line HT29
Authors: Clarke Rosemary G. , Lund Elizabeth K. , Latham Peter , Pinder Andrew C. , Johnson Ian T. 
Published: November 2006

AbstractFish oil has been shown to reduce the induction of colorectal cancer in animal models by a mechanism which may involve suppression of mitosis, increased apoptosis, or both. We used the human colonic adenocarcinoma cell line HT29 to explore the effects of the long‐chain n‐3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) on cell proliferation and death in vitro. Cells were cultured in media containing EPA at 5, 10, and 15 μg/mL. Cell number and thymidine incorporation were used to quantify proliferation, and cell cycle effects were studied using flow cytometry. Gel electrophoresis, annexin‐V binding, and morphological criteria were used to characterize apoptosis. Adherent cells and freely floating detached cells were treated as two distinct populations. In the presence of EPA at 10 and 15 μg/mL there was a marked reduction in the growth rate of adherent HT29 colonies, owing to an increased detachment of adherent cells. After treatment with 10 or 15 μg/mL EPA the proportion of adherent cells in S‐phase increased, indicating either a block in late S‐phase or early G2. Floating cells showed evidence of extensive DNA cleavage, but the proportion of floating cells with sub G0 DNA content declined on treatment with 10 or 15 μg/mL EPA even though the number of floating cells increased. We conclude that EPA does not inhibit mitosis of adherent cells, but increases the rate at which they become detached from the substrate, probably at an early stage in the initiation of apoptosis. This mechanism may be analogous to “anoikis”, or induction of apoptosis in response to loss of cell contact, and may contribute to the anticarcinogenic effects of fish oil in vivo.
Effect of peanut oil and randomized peanut oil on cholesterol and oleic acid absorption, transport, and distribution in the lymph of the rat
Authors: Satchithanandam Subramaniam , Flynn Thomas J. , Calvert Richard J. , Kritchevsky David 
Published: November 2006

AbstractPeanut oil was shown to be atherogenic in cholesterol‐fed rats, rabbits, and monkeys. However, after randomization, a process in which the fatty acids in peanut oil are randomly rearranged, its atherogenicity was significantly reduced in cholesterol‐fed rabbits and monkeys. The mechanism for this effect remains unknown. This study was designed to investigate whether the absorption, transport and distribution of dietary cholesterol and oleic acid in the lymph were altered in the presence of peanut oil or randomized peanut oil. Previous investigators collected lymph through the mesenteric duct for 6 h and analyzed lymph for cholesterol. In the present study, lymph fluids were collected at timed intervals for up to 8 h and then at 24 h via the thoracic duct. Cholesterol and oleic acid (fatty acid) were estimated not only in the whole lymph but also in lymph lipoprotein fractions and in major lipid fractions. A 24‐h lymph collection will enhance accuracy as short‐term fluctuations in lipid absorption will not affect the results. Thoracic duct lymph collection is quantitative compared to mesenteric duct lymph collection, which provides only a fraction of the total lymph. Rats were given a lipid emulsion containing either peanut oil or randomized peanut oil. The emulsion also contained cholesterol, oleic acid, and sodium taurocholate in saline and was given through a duodenal catheter. Results show that absorption, transport, and distribution of cholesterol and oleic acid in the lymph fluids were similar in both dietary groups. These results suggest that the atherogenicity of peanut oil may be due to other events taking place subsequent to the release of cholesterol‐containing chylomicrons and very low density lipoprotein by the small intestinal epithelial cells into the blood or may be due to the triglyceride structure itself.
Dietary phospholipid alters biliary lipid composition in formula‐fed piglets
Authors: Devlin Angela M. , Innis Sheila M. 
Published: November 2006

AbstractPlasma cholesterol, arachidonic acid (AA, 20∶4n−6), and docosahexaenoic acid (DHA, 22∶6n−3) are higher in breast‐fed infants than in infants fed formula without cholesterol, AA, or DHA. This study investigated differences in plasma, hepatic, and bile lipids and phospholipid fatty acids, and expression of hepatic proteins involved in sterol metabolism that result from feeding formula with cholesterol with egg phospholipid to provide AA and DHA. For this study, three groups of piglets were evaluated: piglets fed formula with 0.65 mmol/L cholesterol, the same formula with 0.8% AA and 0.2% DHA from egg phospholipid, and piglets fed sow milk. Piglets fed the formula with phospholipid AA and DHA had higher plasma high density lipoprotein, but not apoprotein (apo) B cholesterol or triglyceride; higher bile acid and phospholipid concentrations in bile; and higher liver and bile phospholipid AA and DHA than piglets fed formula without AA and DHA (P<0.05). Hydroxy methylglutaryl (HMG)‐CoA reductase and 7‐α‐hydroxylase, the rate‐limiting enzymes of cholesterol and bile acid synthesis, respectively, and low density lipoprotein receptor mRNA levels were not different between piglets fed formula without and with phospholipid AA and DHA, but HMG‐CoA reductase and 7α‐hydroxylase mRNA were higher, and plasma apo B containing lipoprotein cholesterol was lower in all piglets fed formula than in piglets fed milk. These studies show that supplementing formula with AA and DHA from egg phospholipid alters bile metabolism by increasing the bile AA and DHA, and bile acid and phospholipid.
Geometry of conjugated double bonds of CLA isomers in a commercial mixture and in their hepatic 20∶4 metabolites
Authors: Sébédio J. L. , Juanéda P. , Grégoire S. , Chardigny J. M. , Martin J. C. , Ginies C. 
Published: November 2006

AbstractRats were fed a fat‐free diet for 2 wk. After this period, while maintaining the animals on the same diet, the rats were given intragastrically 180 mg per day of a mixture of conjugated linoleic acids (CLA) as triacylglycerols. Gas chromatography‐mass spectrometry (GC‐MS) analyses of this mixture, as well as hydrazine reduction and GC‐MS and GC‐Fourier transform infrared analyses of the resulting monoenes, revealed the presence of two major isomers, the 9c, 11t‐and the 10t, 12c‐18∶2 accompanied by smaller amounts of the 8t, 10c and the 11c,13t−18∶2 isomers. Minor quantities of cis,cis and trans,trans conjugated isomers also were detected. The total fatty acid methyl esters from the liver lipids were fractionated by reversed‐phase high‐performance liquid chromatography, and the fraction containing the 20∶4 isomers was further fractionated by silver nitrate thin‐layer chromatography. A band containing two 20∶4 conjugated isomers was submitted to hydrazine reduction and the resulting monoenes analyzed by GC‐MS as dimethyl‐oxazoline derivatives. The two conjugated isomers were tentatively identified as 5c,8c,11c,13t–20∶4 and 5c,8c,12t,14c−20∶4. These could be formed by desaturation and elongation of the 9c,11t‐and 10t,12c−18∶2 present in the commerical CLA mixture.
Synthesis of acetyl, docosahexaenoyl‐glycerophosphocholine and its characterization using nuclear magnetic resonance
Authors: Polette A. , Deshayes C. , Chantegrel B. , Croset M. , Armstrong J. M. , Lagarde M. 
Published: November 2006

AbstractDocosahexaenoic acid (DHA) circulates in mammals in lipoproteins and bound to serum albumin as a nonesterified fatty acid as well as esterified in lysophosphatidylcholine (lysoPC). 1‐Lyso,2‐DHA‐glycerophosphocholine (GPC) is an unstable isomer because of a primary alcohol at the sn‐1 position. To keep DHA at the sn‐2 position of lysoPC, its usual position for the corresponding lysoPC to be acylated into PC in tissues, we synthesized 1‐acetyl,2‐DHA‐GPC and confirmed its structure by use of nuclear magnetic resonance (NMR) spectroscopy in comparison with its positional isomer, 1‐DHA,2‐acetyl‐GPC. 1‐Lyso,2‐DHA‐GPC was prepared from 1‐stearoyl,2‐DHA‐GPC by enzymatic hydrolysis and purified by high‐performance liquid chromatography. The isomerization of 1‐lyso,2‐DHA‐GPC into 1‐DHA,2‐lyso‐GPC was obtained by keeping the former overnight at room temperature under nitrogen. Both lysoPC isomers were acetylated by acetic anhydride into 1‐acetyl,2‐DHA‐GPC and 1‐DHA,2‐acetyl‐GPC, respectively, and the resulting phospholipids were fully characterized by NMR. In particular, the 1,2 substitution pattern of the acetyl and DHA chains could be easily detected by 2D heteronuclear multibond correlation. We conclude that 1‐acetyl,2‐DHA‐GPC might be considered as a stable form of 1‐lyso,2‐DHA‐GPC for its delivery to tissues, if the latter exhibits acetyl hydrolase activity.
n−3 and n−6 fatty acid enrichment by dietary fish oil and phospholipid sources in brain cortical areas and nonneural tissues of formula‐fed piglets
Authors: Goustard‐Langelier Bénédicte , Guesnet Philippe , Durand Georges , Antoine Jean‐Michel , Alessandri Jean‐Marc 
Published: November 2006

AbstractSufficient availability of both n‐3 and n‐6 long‐chain polyunsaturated fatty acids (LCPUFA) is required for optimal structural and functional development in infancy. The question has been raised as to whether infant formulae would benefit from enrichment with 20 and 22 carbon fatty acids. To address this issue, we determined the effect of fish oil and phospholipid (LCPUFA) sources on the fatty acid composition of brain cortical areas and nonneural tissues of newborn piglets fed artificially for 2 wk. They were fed sow milk, a control formula, or the formula enriched with n‐3 fatty acids from a low‐20:5n‐3 fish oil added at a high or a low concentration, or the formula enriched with n‐3 and n‐6 fatty acids from either egg yolk‐ or pig brain‐phospholipids. Both the fish oil‐ and the phospholipid‐enriched formula produced significantly higher plasma phospholipid 22:6n‐3 concentrations than did the control formula. The 22:6n‐3 levels in the brain, hepatic, and intestinal phospholipids were significantly correlated with plasma values, whereas cardiac 22:6n‐3 content appeared to follow a saturable dose‐response. Feeding sow milk resulted in a much higher 20:4n‐6 content in nonneural tissues than did feeding formula. Supplementation with egg phospholipid increased the 20:4n‐6 content in the heart, red blood cells, plasma, and intestine in comparison to the control formula, while pig brain phospholipids exerted this effect in the heart only. The addition of 4.5% fish oil in the formula was associated with a decline in 20:4n‐6 in the cortex, cerebellum, heart, liver, and plasma phospholipids, whereas using this source at 1.5% limited the decline to the cerebellum, liver, and plasma. Whatever the dietary treatment, the phosphatidylethanolamine 20:4n‐6 level was 10–20% higher in the brain temporal lobe than in the parietal, frontal, and occipital lobes in the temporal lobe by administering the formula enriched with egg or brain phospholipids.In conclusion, feeding egg phospholipids to neonatal pigs increased both the 22:6n‐3 content in the brain and the 20:4n‐6 content in the temporal lobe cortex. This source also increased the 22:6n‐3 levels in nonneural tissues with only minor alterations of 20:4n‐6. These data support the notion that infant formulae should be supplemented with both 22:6n‐3 and 20:4n‐6 rather than with 22:6n‐3 alone.
Abnormal serum lysophospholipids in multiple myeloma patients
Authors: Sasagawa Takayo , Okita Misako , Murakami Jun , Kato Tsutomu , Watanabe Akiharu 
Published: November 2006

AbstractLysophosphatidylcholine (LPC) and lysophosphatidic acid (LPA) mediate various kinds of biological activities and play an important role in cellular signal transduction. We analyzed serum phospholipids obtained from 16 multiple myeloma (MM) patients and observed that serum LPA level was significantly higher in MM patients (5.3±0.5 nmol/mL) than in normal controls (1.7±0.3 nmol/mL). LPC level was also higher than that in normal controls, and it correlated significantly with the concentration of LPA (r=0.678, P<0.01). In MM patients, palmitic acid/linoleic acid ratios in phosphatidylcholine and LPC were higher than those in normal controls. In the 12‐mon follow‐up study of two patients with the immune globulin G type, we recognized that the increase of LPC, LPA, and arachidonic acid/linoleic acid ratio in phosphatidylinositol corresponded with a decline in the serum albumin level and choline esterase activity.
Differential effect of N‐ethyl maleimide on Δ6‐desaturase activity in human fetal liver toward fatty acids of the n−6 and n−3 series
Authors: Rodriguez Annie , Sarda Pierre , Boulot Pierre , Leger Claude Louis , Descomps Bernard 
Published: November 2006

AbstractThe effect of N‐ethyl‐maleimide (NEM) on Δ5‐and Δ6‐desaturase activities and the incorporation of substrates and products into different microsomal lipid classes and phospholipid (PL) subclasses were studied in human fetal liver microsomes, obtained after legally approved therapeutic abortion. Desaturase activities were measured by a radiochemical method using reversed‐phase high‐performance liquid chromatography (HPLC). After nonphospholipid (NPL) and PL separation on silica cartridges, the radioactivity in different lipids of the NPL group was assessed by two‐dimensional thin‐layer chromatography, and their fatty acid (FA) composition by gas‐liquid chromatography. The PL subclasses were separated, and the distribution of radioactivity between products and substrates was determined in PL subclasses. NEM inhibited the Δ5‐ and Δ6‐desaturase activities in the n−6 series of FA but not the Δ6‐desaturase activity in the n−3 series, which suggests the existence of two distinct Δ6‐desaturases, one for the n−6 series and another for the n−3 series. Whether NEM was present or absent, most of the radioactivity was recovered in the free FA form (about 80%). The desaturation products, obtained in the presence or absence of NEM, were preferentially incorporated into PL, suggesting a channeling of the newly synthesized FA toward microsomal PL. The comparison of the distribution of substrates and products incorporated into the different PL classes showed that most of the labeled FA were incorporated into phosphatidylcholine and to a lesser degree into phosphatidylethanolamine.
Biosynthesis and localization of phosphatidyl‐scyllo‐inositol in barley aleurone cells
Authors: Carstensen Sven , Pliska‐Matyshak Gay , Bhuvarahamurthy Narasimhan , Robbins Kim M. , Murthy Pushpalatha P. N. 
Published: November 2006

AbstractA novel isomer of phosphatidylinositol (PI), phosphatidyl‐scyllo‐inositol, was characterized in the aleurone cells of barley seeds. In this investigation, the subcellular localization of scyllo‐PI and the relative rates of biosynthesis and accumulation of [32P]phosphoric acid ([32Pi])‐labeled scyllo‐ and myo‐phosphoinositides in the plasma membrane and intracellular membrane pools were investigated. About 25% of the [32Pi]‐labeled phospholipids were present in plasma membrane and 75% in intracellular membranes. Incorporation of [32Pi] into scyllo‐PI was greater than into myo‐PI in both the plasma membranes and intracellular membranes at all time points investigated, thus suggesting a higher rate of biosynthesis; however, the data do not preclude reduced breakdown of labeled scyllo‐PI as a contributing factor. In vitro studies were conducted to investigate the presence of cytidinediphosphate diacylglycerol (CDP‐DG):scyllo‐inositol 3‐phosphatidyltransferase (scyllo‐PI synthase) and to optimize enzymatic activity. The inclusion of nonionic detergents (Brij 58 and Triton X‐100) effected significant enhancement in the biosynthesis of scyllo‐PI, whereas anionic, cationic, and zwitterionic detergents had little or no effect. This is the first evidence for CDP‐DG:scyllo‐inositol 3‐phosphatidyltransferase activity.
The isolation and characterization of right‐side‐out plasma membrane vesicles from barley aleurone cells
Authors: Robbins Kim M. , Bhuvarahamurthy Narasimhan , Pliska‐Matyshak Gay , Murthy Pushpalatha P. N. 
Published: November 2006

AbstractExamination of organelle‐ and membrane‐specific processes such as signal transduction necessitates the use of plasma membrane vesicles with cytoplasmic side‐in orientation. we are interested in the structural identity and subcellular localization of in vivo [32P]phosphoric acid ([32Pi])‐labeled phosphoinositides, including the recently discovered phosphatidyl‐scyllo‐inositol, for signal transduction studies. In the first part of this investigation, plasma membrane vesicles from barley aleurone cells were isolated employing the aqueous polymer (Dextran and polyethylene glycol) two‐phase partition method. The membrane vesicles that partitioned into the upper and lower phases of the aqueous polymer two‐phase system were characterized and the purity of the vesicles ascertained by assaying for two marker enzymes, K+‐stimulated, Mg2+‐dependent adenosine triphosphatase (EC 3.6.1.3, ATPase), localized in the plasma membranes, and cytochrome c oxidase, localized in the mitochondria. Inhibitors for ATPases such as azide, molybdate, and vanadate were used to distinguish between plasma membrane‐associated and intracellular membrane‐as‐sociated ATPases. These inhibitor studies suggest that the plasma membrane preparation contained about 7% of intracellular membrane vesicles and the intracellular membrane fraction contained about 6% of plasma membrane vesicles. Orientation of the plasma membrane vesicles was ascertained by measuring the latent ATPase activity. These latency studies suggest that about 95% of the plasma membrane vesicles were of cytoplasmic side‐in orientation. In the second part of this investigation, intracellular distribution and in vivo [32Pi] labeling of phosphoinositides in the plasma membranes and intracellular membranes were investigated. Preferential accumulation of [32Pi]‐labeled phosphatidyl‐myo‐inositol monophosphate (myo‐PIP) and phosphatidyl‐myo‐inositol bisphosphate (myo‐PIP2) was observed in the plasma membrane. However, scyllo‐phosphatidylinositol (scyllo‐PI) was detected in both the plasma membrane and the intracellular membranes. The cellular concentration of myo‐phosphoinositides was determined, and, after 24 h of labeling with [32Pi], the ratio of radiolabel in myo‐PI, PIP, and PIP2 paralleled the relative concentrations in aleurone cells.
Principal component analysis of measured quantities during degradation of hydroperoxides in oxidized vegetable oils
Authors: Héberger Károly , Keszler Ágnes , Gude Michael 
Published: November 2006

AbstractDecomposition of hydroperoxides in sunflower oil under strictly oxygen‐free conditions was followed by measuring peroxide values against time, absorbance values at 232 and 268 nm, para‐anisidine values, and by quantitative analyses of volatile products using various additives. The results were arranged in a matrix form and subjected to principal component analysis. Three principal components explained 89–97% of the total variance in the data. The measured quantities and the effect of additives were closely related. Characteristic plots showed similarities among the measured quantities (loading plots) and among the additives (score plots). Initial decomposition rate of hydroperoxides and the amount of volatile products formed were similar to each other. The outliers, the absorbance values, were similar to each other but carried independent information from the other quantities. Para‐anisidine value (PAV) was a unique parameter. Since PAV behaved differently during the course of hydroperoxide degradation, it served as a kinetic indicator. Most additives were similar in their effects on the mentioned quantities, but two outliers were also observed. Rotation of the principal component axes did not change the dominant patterns observed. The investigations clearly showed which variables were worth measuring to evaluate different additives.
Long‐term behavior of oil‐based varnishes and paints. Photo‐ and thermooxidation of cured linseed oil
Authors: Mallégol Jacky , Gardette Jean‐Luc , Lemaire Jacques 
Published: November 2006

AbstractThermooxidation at 100°C and photooxidation at wavelengths above 300 nm of dried oil films were evaluated. The chemical modifications of the networks were determined by infrared analysis coupled with gaseous treatments (NO, SF4, and NH3). The dried films are rather stable in thermooxidation, whereas in photooxidation, important degradation of the network occurs with many chain scissions. This photoinstability results from the presence of crosslinks that are sensitive to radical attack because of the lability of the hydrogen atom on the tertiary carbons. The photooxidation reactions are fully described in this paper. Yellowing of the cured samples, observed with ultraviolet‐visible and fluorescence spectrometries, rapidly is decreased by irradiation because the oil contaminants that are mainly responsible for the yellowness are photooxidized. On the contrary, yellowing slowly but continuously increases during thermooxidation at 100°C.