bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stable‐isotope method for determining the gastrointestinal handling of [1‐13C]Palmitic acid
Authors: Stolinski Michael , Murphy Jane L. , Jones Amanda E. , Jackson Alan A. , Wootton Stephen A. 
Published: November 2006

AbstractThe 13C enrichment in individual fatty acids extracted from human feces following the oral administration of [1‐13C]palmitic acid has been determined using a novel approach based upon gas chromatography‐isotope ratio mass spectrometry. The method was established and tested for precision and repeatability. Analytical precision was determined from 10 repeated injections of a sample containing 16∶0 and 18∶0 with levels of δ13C abundance measured at −34.01±0.60 and −23.62±0.95 delta per mil (parts per thousand) (‰), respectively (mean±SD). For the repeatability study, measurement of enrichment of the same mixture of unlabeled fatty acid methyl ester (FAME) standards (13∶0, 14∶0, 16∶0, and 18∶0) was found to have standard deviations (0.45, 0.56, 1.46 and 1.54‰ respectively). When labeled [1‐13C]palmitic acid was serially diluted with naturally enriched palmitic acid, a linear relationship was obtained to a dilution of 10% enriched compound (530‰). FAME were prepared from two fecal samples from a normal healthy adult; the first, a baseline specimen, containing no added label and the second, followed a single oral dose of [1‐13C]palmitic acid and was enriched. Enrichment in 13C was confined to the solvent‐soluble fraction following lipid extraction, and was only identified with prior acidification. The enrichments were measured in triplicate, baseline sample −32.66±0.5‰ enriched sample +268.61±8.0‰ Enrichment was restricted to the labeled species consumed, 16∶0. The methodology described here allows for the separation of compounds prior to the determination of enrichment and can be utilized to contribute to a more complete description of the gastrointestinal handling of labeled substrates than previously obtained.
Dietary docosahexaenoic acid as a source of eicosapentaenoic acid in vegetarians and omnivores
Authors: Conquer Julie A. , Holub Bruce J. 
Published: November 2006

AbstractThe utilization of dietary docosahexaenoic acid (DHA; 22:6n−3) as a source of eicosapentaenoic acid (EPA; 20:5n−3) via retroconversion was investigated in both vegetarians and omnivores. For this purpose, an EPA‐free preparation of DHA was given as a daily supplement (1.62 g DHA) over a period of 6 wk. The dietary supplement provided for a marked increase in DHA levels in both serum phospholipid (from 2.1 to 7.1 mol% in vegetarians and 2.2 to 7.6 mol% in omnivores) and platelet phospholipid (from 1.1 to 3.4 mol% in vegetarians and 1.4 to 3.9 mol% in omnivores). EPA levels rose to a significant but much lesser extent, while 20:4n−6, 22:5n−6, and 22:5n−3 all decreased. Based on the serum phospholipid data, the retroconversion of DHA to EPA in vivo was estimated to be 9.4% overall with no significant difference between omnivores and vegetarians.
Bile acid metabolism in young‐old parabiotic rats
Authors: Uchida Kiyohisa , Takase Haruto , Nomura Yasuharu , Satoh Takashi , Igimi Hirotsune , Takeuchi Nozomu 
Published: November 2006

AbstractSerum cholesterol, triglyceride and phospholipid levels, liver cholesterol concentration, bile flow, biliary cholesterol, phospholipid and bile acid secretion rates, fecal sterol and bile acid levels and their bile acid compositions were examined in young‐old parabiotic rats and compared with those in young and old control rats and young‐young parabiotic rats. Bile acid composition was expressed in terms of the cholic acid group/chenodeoxycholic acid group (CA/CDCA) ratio. Body weight (BW) gain decreased after parabiosis especially in old rats, but the liver weight (g/100 g BW), diet‐intake, feces dry weight, liver cholesterol concentration and fecal sterol level were almost the same in all the groups. The biliary bile acid secretion rate was higher and the fecal bile acid level was lower in old rats than those in young rats but both the levels became comparable with those in young rats after parabiosis of old rats with young rats. Young rats, however, showed no changes in these levels after parabiosis. The serum cholesterol level and the biliary and fecal CA/CDCA ratios in old rats were higher than those in young rats but decreased after parabiosis with young rats, although they were still higher than those in young rats. The serum cholesterol level in young rats increased after parabiosis with old rats, but not after parabiosis with young rats, and the fecal bile acid level and the CA/CDCA ratio were not changed in either case. It is concluded from these findings that the serum cholesterol level and the CA/CDCA ratio increased with age and that these increases were prevented after parabiosis with young rats, while young rats, although their serum cholesterol level was increased, showed no increase in the CA/CDCA ratio after parabiosis with old rats.
Comparative hypocholesterolemic effects of capybara (Hydrochoerus hydrochaeris dabbenei) oil, horse oil, and sardine oil in cholesterol‐fed rats
Authors: Fukushima Michihiro , Takayama Yasuyoshi , Habaguchi Tsuyoshi , Nakano Masuo 
Published: November 2006

AbstractThe hypocholesterolemic efficacy of various polyunsaturated fatty acids was compared in rats given cholesterol‐enriched diets. Capybara oil (CO, linoleic+α‐linolenic acids), horse oil (HO, α‐linolenic acid), and sardine oil (SO, eicosapentaenoic+docosahexaenoic acids) were added to diets at 50 g/kg. The weight gain, food intake, and liver weight in the CO‐fed group were significantly higher than those in other groups during the 6‐wk experimental period. The serum total and very low density lipoprotein (VLDL)+intermediate density lipoprotein (IDL)+low density lipoprotein (LDL) cholesterol concentrations of the CO‐fed and SO‐fed groups were significantly lower than in the HO‐fed group after 6 wk. The serum high density lipoprotein cholesterol concentration in the SO‐fed group was significantly higher than that in the CO‐fed and HO‐fed groups. The fecal neutral sterol concentration in the CO‐fed group was reduced significantly compared with the other groups, and the fecal bile acid concentration in the HO‐fed group was significantly higher than that in the SO‐fed group. The results of this study demonstrate that CO lowers the serum total cholesterol and VLDL+IDL+LDL‐cholesterol concentrations in the presence of excess cholesterol in the diet as well as SO.
High levels of dietary arachidonic acid triglyceride exhibit no subchronic toxicity in rats
Authors: Koskelo E. ‐K. , Boswell K. , Carl L. , Lanoue S. , Kelly C. , Kyle D. 
Published: November 2006

AbstractArachidonic acid (AA), an n−6 long‐chain polyunsaturated fatty acid (LC‐PUFA), serves an important role in the body as a structural fatty acid of many tissues including neurological tissues. It is also a precursor of the n−6 class of eicosanoids and is the most abundant n−6 LC‐PUFA found in human breast milk. We have optimized the production of a microfungal source of a triglyceride oil (ARASCO®) which is enriched in AA to about 40% by weight. To establish the safety of this oil as a food, we evaluated the effect of ARASCO® in Sprague‐Dawley rats (20/sex/group) gavaged at dose levels of 1.0 and 2.5 g/kg/d for a period of 90 d, paying special attention to any potential neurotoxicity of the oil. Two groups of control animals received either untreated standard laboratory diet (untreated control) or the same diet and vehicle oil at the same dose volume administered to the treated animals (vehicle control). Physical observations, ophthalmoscopic examinations, body weight, food consumption, clinical chemistry, hematology parameters, neurobehavioral assessments, and macroscopic as well as microscopic postmortem evaluations were performed. Tissue fatty acid analyses indicated that the AA levels in the brain, heart, and liver of the high‐dose ARASCO®‐fed animals increased by 8, 59, and 76%, respectively, indicating that the AA in the oil was readily incorporated into tissue lipids. In spite of this high elevation in tissue AA levels, no developmental, histopathological, or neuropathological differences were seen in the animals administered ARASCO® compared with the vehicle control animals. Being highly enriched in AA, ARASCO® offers the means to study the effect of this fatty acid in experimental settings and in human metabolic studies.
Possible fatty acyl pheromone precursors in Spodoptera littoralis. Search for 11‐ and 12‐hydroxytetradecanoic acids in the pheromone gland
Authors: Navarro Isabel , Fabriàs Gemma , Camps Francisco 
Published: November 2006

AbstractLipidic extracts of Spodoptera littoralis pheromone glands submitted to acid methanolysis using: (i) sulfuric acid/methanol/benzene (0.1∶4∶2, by vol) at 90°C for 1 h; (ii) 12 N HCl/methanol (1∶2; vol/vol) at 90°C for 1 h, or (iii) 14% BF3‐MeOH at 90°C for 1 h did not reveal the presence of either 11‐ or 12‐hydroxytetradecanoic acid in the extracts, as concluded from the gas chromatography‐mass spectrometry analyses. Under the above methanolysis conditions, a synthetic sample of methyl (14, 14, 15‐2H3) 12‐hydroxytetradecanoate remained unaltered. These results may indicate that formation of (E)‐11‐tetradecenoic acid from tetradecanoic acid does not occur in the pheromone gland by dehydration of an intermediate hydroxyacid. Acid methanolysis of a lipidic extract using BF3‐MeOH led to the formation of a mixture of methoxy fatty acid methyl esters, identified by gas chromatography‐mass spectrometry. These methoxy derivatives should arise from BF3‐catalyzed addition of methanol to the double bond of the natural monounsaturated fatty acyl derivatives present in the gland. Thus, under the same conditions, a synthetic sample of methyl (Z)‐11‐tetradecenoate was partially transformed into methyl 11‐methoxytetradecanoate and methyl 12‐methoxytetradecanoate. This reaction might be a useful alternative procedure to obtain methoxy derivatives of olefins, which are very helpful for the structural characterization of the parent alkenes.
A human dietary arachidonic acid supplementation study conducted in a metabolic research unit: Radionale and design
Authors: Nelson G. J. , Kelly D. S. , Emken E. A. , Phinney S. D. , Kyle David , Ferretti Aldo 
Published: November 2006

AbstractWhile there are many reports of studies that fed arachidonic acid (AA) to animals, there are very few reports of AA feeding to humans under controlled conditions. This 130‐d study was conceived as a controlled, symmetrical crossover design with healthy, adult male volunteers. They lived in the metabolic research unit (MRU) of the Western Human Nutrition Research (WHNRC) for the entire study. All food was prepared by the WHNRC kitchen. The basal (low‐AA) diet consisted of natural foods (30 en% fat, 15 en% protein, and 55 en% carbohydrate), containing 210 mg/d of AA, and met the recommended daily allowance for all nutrients. The high‐AA (intervention) diet was similar except that 1.5 g/d of AA in the form of a triglyceride containing 50% AA replaced an equal amount of high‐oleic safflower oil in the basal diet. The subjects (ages 20 to 39) were within −10 to +20% of ideal body weight, nonsmoking, and not allowed alcohol in the MRU. Their exercise level was constant, and their body weights were maintained within 2% of entry level. Subjects were initially fed the low‐AA diet for 15 d. On day 16, half of the subjects (group A) were placed on the high‐AA diet, and the other group (B) remained on the low‐AA diet. On day 65, the two groups switched diets. On day 115, group B returned to the low‐AA diet. This design, assuming no carryover effect, allowed us to merge the data from the two groups, with the data comparison days being 65 (low‐AA) and 115 (high‐AA) for group B and 130 (low‐AA) and 65 (high‐AA) for group A. The main indices studied were the fatty acid composition of the plasma, red blood cells, platelets, and adipose tissue; in vitro platelet aggregation, bleeding times, clotting factors; immune response as measured by delayed hypersensitivity skin tests, cellular proliferation of peripheral blood mononuclear cells in response to various mitogene and antigens, natural killer cell activity, and response to measles/mumps/rubella and influenza vaccines; the metabolic conversion of deuterated linoleic acid to AA and the metabolic fate of deuterated AA in the subjects on and off the high‐AA diet; and the production of eicosanoids as measured by excretion of 11‐DTXB2 and PGI2‐M in urine. The results of these studies with be presented in the next five papers from this symposium.
The effect of dietary arachidonic acid on plasma lipoprotein distributions, apoproteins, blood lipid levels, and tissue fatty acid composition in humans
Authors: Nelson G. J. , Schmidt P. C. , Bartolini G. , Kelley D. S. , Phinney S. D. , Kyle David , Silbermann Steven , Schaefer Ernst J. 
Published: November 2006

AbstractNormal healthy male volunteers (n=10) were fed diets (high‐AA) containing 1.7 g/d of arachidonic acid (AA) for 50 d. The control (low‐AA) diet contained 210 mg/d of AA. Dietary AA had no statistically significant effect on the blood cholesterol levels, lipoprotein distribution, or apoprotein levels. Adipose tissue fatty acid composition was not influenced by AA feeding. The plasma total fatty acid composition was markedly enriched in AA after 50 d (P<0.005). The fatty acid composition of plasma lipid fractions, cholesterol esters, triglycerides, free fatty acids, and phospholipid (PL) showed marked differences in the degree of enrichment in AA. The PL plasma fraction from the subjects consuming the low‐AA diet contained 10.3% AA while the subjects who consumed the high‐AA diet had plasma PL fractions containing 19.0% AA. The level of 22:4n‐6 also was different (0.67 to 1.06%) in the plasma PL fraction after 50 d of AA feeding. After consuming the high‐AA diet, the total red blood cell fatty acid composition was significantly enriched in AA which mainly replaced linoleic acid. These results indicate that dietary AA is incorporated into tissue lipids, but selectively into different tissues and lipid classes. Perhaps more importantly, the results demonstrate that dietary AA does not alter blood lipids or lipoprotein levels or have obvious adverse health effects at this level and duration of feeding.
Effects of dietary arachidonic acid on human immune response
Authors: Kelley Darshan S. , Taylor Peter C. , Nelson Gary J. , Schmidt Perla C. , Mackey Bruce E. , Kyle David 
Published: November 2006

AbstractArachidonic acid (AA) is a precursor of eicosanoids, which influence human health and the in vitro activity of immune cells. We therefore examined the effects of dietary AA on the immune response (IR) of 10 healthy men living at our metabolic suite for 130 d. All subjects were fed a basal diet containing 27 energy percentage (en%) fat, 57 en% carbohydrate, and 16 en% protein (AA, 200 mg/d) for the first and last 15 d of the study. Additional AA (1.5 g/d) was incorporated into the diet of six men from day 16 to 65 while the remaining four subjects continued to eat the basal diet. The diets of the two groups were crossed‐over from day 66 to 115. In vitro indexes of IR were examined using the blood samples drawn on days 15, 58, 65, 108, 115, and 127. The subjects were immunized with the measles/mumps/rubella vaccine on day 35 and with the influenza vaccine on day 92. Dietary AA did not influence many indexes of IR (peripheral blood mononuclear cell proliferation in response to phytohemagglutinin, Concanavalin A, pokeweed, measles/mumps/rubella, and influenza vaccines prior to immunization, and natural killer cell activity). The postimmunization proliferation in response to influenza vaccine was about fourfold higher in the group receiving high‐AA diet compared to the group receiving low‐AA diet (P=0.02). Analysis of variance of the data pooled from both groups showed that the number of circulating granulocytes was significantly (P=0.03) more when the subjects were fed the high‐AA diet than when they were fed the low‐AA diet. The small increases in granulocyte count and the in vitro proliferation in response to influenza vaccine caused by dietary AA may not be of clinical significance. However, the lack of any adverse effects on IR indicates that supplementation with AA may be done safely when needed for other health reasons.
Age‐related changes in catalytic activity, enzyme mass, mRNA, and subcellular distribution of hepatic neutral cholesterol ester hydrolase in female rats
Authors: Natarajan Ramesh , Ghosh Shobha , McLean Grogan W. 
Published: November 2006

AbstractActivity and protein mass of hepatic neutral cholesteryl ester hydrolase (CEH) were measured in liver cytosol and washed microsomes of female Sprague‐Dawley rats aged 3, 4, 7, 9, 12, and 16 wk. CEH mRNA was also measured. The microsomal component varied with age and contributed a greater fraction of total activity in females than previously reported in males. Nevertheless, the cytosolic component accounted for 62–80% of activity and 77–94% of immunoreactive protein in postmitochondrial fractions. Cytosolic and microsomal CEH specific activities, relative to total protein, decreased 94 and 83%, respectively, from 3 to 4 wk, prior to onset of puberty at 5 wk, and increased 360 and 137%, respectively, from 12 to 16 wk. These results contrast with an earlier study, in which cytosolic CEH activity of males increased with puberty and declined after 12 wk. Although cytosolic CEH was activated by protein kinase A and inhibited by alkaline phosphatase treatment at all ages, protein kinase activation peaked at 4 wk, coinciding with the initial decrease, in specific activity. Specific activity in cytosol and microsomes correlated with CEH mass at all ages, suggesting that this CEH accounts for most variation in cellular activity. In contrast, CEH mRNA varied little from 3–16 wk, indicating that transcriptional regulation does not make a major contribution to the variation in CEH activity and mass in females, although it may make an important contribution to male‐female differences in CEH expression. Specific activities of cytosolic and microsomal CEH, relative to immunoreactive CEH protein mass, exhibited changes consistent with posttranslational regulation. These results indicate gender‐specific multivalent regulation of hepatic CEH by posttranslational mechanisms during development of female rats.
Biosynthesis of medium‐chain triacylglycerols and phospholipids by HepG‐2 cells
Authors: Pakula Ronit , Rubin Moshe , Moser Asher Moshe , Lichtenberg Dov , Tietz Alisa 
Published: November 2006

AbstractIn an attempt to understand the metabolism by the liver of fatty acids (FA) of different chain length, we have studied the incorporation of [1‐14C]‐labeled C2, C8, C10, C12, and C16 into cellular lipids by HepG‐2 cells. Over 90% of the radiolabeled FA were detected in phospholipids (PL) and triacylglycerols (TAG). The incorporation of C12 and C16 was three to four times higher than that of C8 and C10 (and reached 35 nmoles per mg protein after 1.5 h). The radioactivity of C2, C8, and C10 was recovered mainly in PL. C12 and C16 were incorporated at approximately equal amounts into PL and TAG. The radioactivity of both C2 and C8 was recovered exclusively in long‐chain FA, suggesting oxidation of C8 into C2 units prior to FA synthesis. C10 likewise yielded mainly long‐chain FA. However 10% of unchanged C10 was found in PL and up to 30% in TAG. 14C–C12 was largely incorporated unchanged. Under these conditions, the presence of C10 and C12 in PL and TAG was shown also by gas‐liquid chromatography. In the presence of either C2, C8, or C10, up to 30% of 14C‐monounsaturated FA were detected in PL and TAG. With C12 and C16, the fraction of 14C‐monounsaturated FA was much smaller suggesting that extensive desaturation occurred during de novo synthesis.
Molecular species of phosphoglycerides in liver microsomes of rats fed a fat‐free diet
Authors: Garda Horacio A. , Bernasconi Ana M. , Tricerri M. Alejandra , Brenner Rodolfo R. 
Published: November 2006

AbstractThe influence of a fat‐free diet on the molecular species composition of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI) of rat liver microsomes was studied by using reversed‐phase high‐pressure liquid chromatography. In the three phosphoglyceride classes analyzed, the fat‐free diet produced a large decrease in the 18:0/20:4n−6 species but less important changes were found in the 16:0/20:4n−6 species. In PC, the most abundant phosphoglyceride class of rat liver microsomes, the fall in the 18:0/20:4n−6 species was counterbalanced mainly by an enhancement in the 16:0/18:1n−9 species although it was not evident in PE. In PI, the decrease in the 18:0/20:4n−6 species was counterbalanced by an increase in the 18:0/20:3n−9 species. Fluorescence polarization measurements of 1,6‐diphenyl‐1,3,5‐hexatriene in liposomes of 16:0/18:1n−9‐, 18:0/18:1n−9‐, 16:0/20:4n−6‐, and 18:0/20:4n−6‐PC indicated that the change in the saturated fatty acid in the sn‐1 position accompanying the replacement of 20:4n−6 by 18:1n−9 could be very important for a homeoviscous compensation, maintaining the membrane physical properties without large alterations in spite of the essential fatty acid deficiency due to the fat‐free diet.
Lipid peroxidation during n−3 fatty acid and vitamin E supplementation in humans
Authors: Allard Johane P. , Kurian Regina , Aghdassi Elaheh , Muggli Reto , Royall Dawna 
Published: November 2006

AbstractThe purpose of this study was to investigate in healthy humans the effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake, alone or in combination with dL‐α‐tocopherol acetate (vitamin E) supplements on lipid peroxidation. Eightly men were randomly assigned in a double‐blind fashion to take daily for 6 wk either menhaden oil (6.26 g, n−3 fatty acids) or olive oil supplements with either vitamin E (900 IU) or its placebo. Antioxidant vitamins, phospholipid composition, malondialdehyde (MDA), and lipid peroxides were measured in the plasma at baseline and week 6. At the same time, breath alkane output was measured. Plasma α‐tocopherol concentration increased in those receiving vitamin E (P<0.0001). In those supplemented with n−3 fatty acids, EPA and DHA increased in plasma phospholipids (P<0.0001) and plasma MDA and lipid peroxides increased (P<0.001 and P<0.05, respectively). Breath alkane output did not change significantly and vitamin E intake did not prevent the increase in lipid peroxidation during menhaden oil supplementation. The results demonstrate that supplementing the diet with n−3 fatty acids resulted in an increase in lipid peroxidation, as measured by plasma MDA release and lipid peroxide products, which was not suppressed by vitamin E supplementation.