bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of environmental medium on fatty acid composition of human cells: Leukocytes and fibroblasts
Authors: Delplanque B. , Jacotot B. 
Published: November 2006

AbstractFibroblasts in culture and leukocytes have been widely used to study fatty acid and lipoprotein cellular metabolism. The present investigations were designed to study the role of nutritional and environmental factors on lipid metabolism in these two types of cells. Leukocytes freshly isolated from human blood and fibroblasts cultured in media enriched in human serum (HS) have relatively similar fatty acid distributions. However, more important differences are observed in fibroblasts cultured in media enriched with HS or with fetal bovine serum (FBS). It is obvious that the quantity and quality of fatty acids are very different in FBS and HS, but intracellular regulation ensures relative homogeneity of saturated (SFA) and monounsaturated fatty acids (MUFA) in the cells, particularly in phospholipids.The first modifications induced by different media (FBS or HS) are detected on cellular growth; the differences seem to be due more to the fatty acid (FA) quantitative supply than to the FA quality of each culture medium. The major modifications in FA composition induced by different culture media concern the polyunsaturated fatty acids (PUFA) of phospholipids, especially the n−6 family. The intracellular linoleic acid level depends on the level in the medium, but intracellular n−6 metabolite levels depend both on the level in the medium and on the growth state of the cells. The n−3 family seems to be less affected by the quality of the medium in our experiment, and the cells maintain a stable docosahexaenoic acid (22∶6n−3) level. A higher content of the n−3 family in the medium induces a higher level of eicosa‐or docosapentaenoic acid, rather than docosahexaenoic acid itself.Finally, the FA quality of the medium influences the cellular PUFA content but, with a low FA quantitative supply, the FA quality of the medium has less influence on the cellular PUFA quality, and apparently has no effect on the SFA content of phospholipids. Modification of the quantitative supply of the medium and of the quality of the cells (strain and growing state) are more important for the distribution of SFA and MUFA in the neutral lipids of the cells.
1‐Acyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine from stimulated human polymorphonuclear leukocytes
Authors: Satouchi Kiyoshi , Oda Makoto , Saito Kunihiko 
Published: November 2006

Abstract1‐Acyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine (1‐acyl‐2‐acetyl GPC) was found in the fraction of platelet‐activating factor obtained from stimulated human polymorphonuclear leukocytes (PMN). The amount of 1‐acyl‐2‐acetyl GPC obtained from 1×107 PMN stimulated with ionophore A23187 at 37 C for 15 min ranged from 8 to 56 pmol (32±10 pmol, mean±standard error; n=4). The main species was 16∶0 palmitoyl (17±5 pmol), followed by 18∶0 stearoyl (8±3 pmol) and 18∶1 oleoyl (7±3 pmol).Although the physiological significance is unknown, 1‐acyl‐2‐acetyl GPC was always detected when 1‐alkyl‐2‐acetyl GPC was detected.
Rapid analysis of jojoba wax fatty acids and alcohols after derivatization using Grignard reagents
Authors: Pina M. , Pioch D. , Graille J. 
Published: November 2006

AbstractThis method, based on the action of Grignard reagents, is an original approach to wax derivatization and differs from the methods previously described, which were essentially based on wax alcoholysis. Grignard reagents, especially magnesium ethyl bromide, react on ester functions to turn the wax constituents into primary and tertiary alcohols, the latter being the fatty acid derivatives. The mixture of these alcohols is analyzed by a single gas chromatographic injection. The overall time, about 1.5 hr, makes this method suitable for routine analysis. It could be also considered for analyzing low carbon condensation organic acid esters.
Biosynthesis of hydrocarbons by algae: Decarboxylation of stearic acid to N‐heptadecane inAnacystis nidulans determined by13C‐ and2H‐labeling and13C nuclear magnetic resonance
Authors: McInnes A. Gavin , Walter John A. , Wright Jeffrey L. C. 
Published: November 2006

AbstractThe distribution of isotopic labels inn‐heptadecane enriched from [1,2‐13C] and [2‐13C, 2‐2H3) acetates byAnacystis nidulans has been determined by13C nuclear magnetic resonance (13C NMR). Labeling with [1,2‐13C] acetate is consistent with assembly from13C−13C units derived from an acetate “starter” group and 8 malonate units, as in fatty acid biosynthesis, followed by production of a methyl group through bond cleavage of the terminal13C−13C unit. A comparison of the hydrocarbon with palmitic acid (the only fatty acid produced in sufficient amount for NMR analysis) enriched from [2‐13C,2‐2H3]acetate by the same culture shows that they have retained the same fraction of2H at corresponding sites, and have therefore undergone identical biosynthetic and hydrogen‐deuterium exchange processes, as would be expected ifn‐heptadecane originates from de novo‐synthesized stearic acid.
Lipoprotein lipid and protein synthesis in experimental nephrosis and plasmapheresis: II. Perfused rat liver
Authors: Brenner Talma , Shafrir Eleazar 
Published: November 2006

AbstractLivers from rats with experimental hypoproteinemia induced by aminonucleoside‐nephrosis or plasmapheresis were perfused with a [14C]‐labeled amino acid mixture at physiological concentration. Compared to control rats, a significantly increased incorporation of the amino acid label was found in the apolipoproteins of the ultracentrifugally separated very low and high density lipoproteins (VLDL, HDL), and into albumin secreted into the perfusate. However, no increase in the amino acid‐derived label was detected in VLDL‐ or HDL‐borne lipids in nephrosis or plasmapheresis. Perfusion with U‐[14C] leucine as a lipogenesis precursor at >10 times higher than physiological concentration resulted in 5‐fold increase in the label incorporation into perfusate proteins in nephrosis but only in a slightly significant increase in perfusate lipids. In contrast, the incorporation of a preformed fatty acid, 9,10‐[3H] oleate into VLDL and HDL lipids increased 3‐ to 4‐fold in nephrosis. Both with leucine and oleate as precursors, the increments in the label appearing in perfusate proteins or lipids, respectively, were markedly greater than the increases in hepatic tissue proteins or lipids. The results indicate that amino acids are preferentially directed by the liver into the synthesis of circulating apolipoproteins and albumin in hypoproteinemia and do not seem to constitute an important precursor of the lipoprotein lipids. The increased production of apolipoproteins is associated with an increased incorporation of preformed fatty acids into lipoprotein lipids in addition to the previously reported stimulation of hepatic de novo lipid synthesis from precursors other than amino acids.
Analysis and physiologic significance of cholesterol epoxide in animal tissues
Authors: Black Homer S. 
Published: November 2006

AbstractThe presence of 5α,6α‐epoxy‐cholestan‐3β‐ol, an oxidation product of cholesterol, has been demonstrated in a variety of animal tissues. No definitive biologic role for this sterol has been forthcoming, although the physiologic implications of its occurrence are many. The presence of the epoxide in ultraviolet (UV)‐irradiated skin was detected by a combination of thin layer chromatography (TLC) and gas liquid radiochromatographic (radio‐GLC) techniques in 1971 and led to the suggestion that it might be responsible for the carcinogenic properties of UV. Subsequently, in vivo levels of this sterol in the skin of UV‐irradiated animals were quantitated by radio‐GLC after TLC separation and preparation of the radiolabeled acetate ester. Presence of the compound in mouse liver was detected by GLC of the trimethylsilyl (TMS) ether and confirmed by mass spectrometry (MS). In all cases, however, in vivo quantitations were complicated by substrate induction of sterol epoxide hydrase, an enzyme that hydrates the epoxide to form cholestan‐3β,5α,6β‐triol (triol). Consequently, the relationship of the sterol epoxide to UV‐carcinogenesis is as yet unclear and recent studies suggest that if this sterol is involved, then further metabolism of the compound must be required. A practical means of examining the metabolites of the epoxide was developed, employing radio‐TLC scanning. Using this procedure, the relationships of substrate concentration, time of reaction and pH optimum to reaction rate were determined. Although in short term in vitro incubations of liver homogenates the bulk of epoxide is hydrated to triol, several other metabolites are detectable by TLC autoradiography. Even though the case for direct involvement of cholesterol epoxide in the etiology of carcinogenesis or other diseases is equivocal, the epoxide or its metabolites may yet prove valuable as a diagnostic aid in revealing abnormal function associated with certain diseases.
Utilization of polyunsaturated fatty acids by human diploid cells aging in vitro
Authors: Lynch Robert D. 
Published: November 2006

AbstractCultures of human diploid cell strain IMR‐90 were supplemented with γ‐linolenic acid, 18∶3ω6, by constant infusion over 72 hr. Cell growth was twice that observed when the same amount of fatty acid was supplied as a single dose at the start of a 72‐hr incubation. Using the infusion method, growth of cells receiving monoenoic or polyenoic fatty acids was compared. The age of these cells in vitro was measured in terms of the culture mean population doubling level (PDL). Population doubling level refers to the mean number of doublings elapsed since establishment of a primary culture. At PDL from 24–53, the growth of cells from cultures supplemented with oleic acid was similar to that of noninfused cultures. Gamma linolenic acid, 18∶3ω6, and to greater extent arachidonic acid, 20∶4ω6, however, caused suppression of cell multiplication at PDL≤32, but not at PDL≥44. The polyunsaturated fatty acid (PUFA) levels in cell phospholipids were reduced by exogenous oleic acid to half that of nonsupplemented cells at all PDL tested. Conversely, the PUFA levels in phospholipids were elevated by a factor of 1.6 at all PDL when cultures were infused with 18∶3ω6. Triglyceride levels at the end of 72 hr were similar, but much higher than the controls, regardless of the fatty acid supplied. Growth inhibition, modification of phospholipid acyl group content and triglyceride levels were not appreciably affected when the amount of monoenoic or polyenoic fatty acid infused into the cultures was doubled. The elongation of 18∶3, as well as the distribution of 18∶3 and its elongation products, between triglyceride and phospholipid, was dependent on whether the 18∶3 was of the ω3 or ω6 family.
Changes in host animal plasma lipids during hepatoma growth
Authors: Matocha Martha , Wood Randall 
Published: November 2006

AbstractThe concentrations of the major neutral lipid and phospholipid classes in the plasma of rats bearing hepatoma 7288CTC were determined at various times after transplantation. The fatty acid composition of each lipid class was also analyzed quantitatively as tumor growth progressed. Generally, most lipid classes exhibited a slight decrease between the third and sixth day after transplantation, returned to near normal levels by the 15th day, increased dramatically and peaked between the 24th and 27th days before plummeting sharply. At peak concentrations, triglycerides were increased 5 times the normal levels, whereas cholesterol, cholesteryl esters and phosphatidylcholines were increased 3‐fold. The percentage of hexadecenoates decreased in all lipid classes as tumor growth progressed and generally, stearate levels increased. In addition to monounsaturated fatty acids, lysophosphatidylcholines and phosphatidylcholines showed relatively large decreases in the percentages of polyunsaturated fatty acids with increased tumor growth. These results indicate that hepatoma 7288CTC can cause perturbation of host animal plasma lipids in the early stages of growth which precedes the massive hyperlipidemia. The interpretation of these results suggests that the early changes in plasma lipids may result from alterations in the normal lipid metabolism of the host, and the hyperlipidemia that develops later may result from the mobilization of lipids to compensate for the altered metabolism.
Lecithin influence on hyperlipemia in rhesus monkeys
Authors: Wong E. K. , Nicolosi R. J. , Low P. A. , Herd J. A. , Hayes K. C. 
Published: November 2006

AbstractPrevious studies in humans have shown that the ingestion of lecithin can alter plasma cholesterol and triglyceride concentrations by mechanism(s) that remain to be elucidated. To further explore this response to lecithin, hyperlipemic rhesus monkeys were selected from a group of animals fed a semipurified diet containing corn oil, casein, sucrose and cholesterol (120 mg/100 Kcal) for 10 years. Soybean lecithin (92% phosphatidylcholine) was supplemented in the diet (0.5 g/100 Kcal) of these monkeys. Measurements of plasma cholesterol, triglycerides and phospholipid were made prior to, during and following 7 wk of lecithin supplementation. In addition, determinations of triglyceride secretion rates following administration of Triton WR1339, triglyceride clearance after intravenous infusion of Intralipid® and plasma lecithin:cholesterol acyl transferase enzyme (LCAT) activity were assessed at the same time intervals. As in other studies, manipulation of lecithin intake elicited a highly variable response, but significant changes were observed in plasma cholesterol and triglycerides as a consequence of supplementing or removing lecithin from the diet. Lecithin had no influence on the absolute plasma phospholipid level or LCAT activity. However, lecithin significantly reduced total lipids, increased the relative concentration of phospholipid and tended to increase the phospholipid/free cholesterol (PL/FC) concentration. While lecithin did not significantly affect triglyceride secretion rates, all animals were able to clear Intralipid® (triglyceride) more efficiently while fed lecithin. These data are interpreted to mean that the reduction in plasma lipids associated with lecithin ingestion may have been mediated via enhanced clearance of lipids transported in lipoproteins of lower density, whereas the rebound following lecithin removal reflected reduced clearance of these lipids.
Effect of colestipol on sterol metabolism in the rat
Authors: Takahashi Makoto , Sarwal Amar N. , Raicht Robert F. , Cohen Bertram I. 
Published: November 2006

AbstractSterol metabolism studies using isotopic and chromatographic techniques were performed on rats fed diets supplemented with colestipol (Upjohn). Compared to controls, colestipol altered sterol metabolism dramatically. Bile acid output increased from 7.0 mg/day to 12.2 mg/day (0.42% colestipol) and 39.6 mg/day (1.67% colestipol). Daily fecal neutral sterol output and daily endogenous neutral sterol output increased 36% and 55%, respectively, on the 1.67% colestipol diet. Cholesterol absorption was reduced by colestipol feeding. Cholesterol balance increased dramatically with 1.67% colestipol administration (43.5 mg/day vs −1.0 mg/day in controls). Colestipol exerts its effect by binding bile acids and by bile acid depletion interfering with cholesterol absorption.
Carotene in bovine milk fat globules: Observations on origin and high content in tissue mitochondria
Authors: Patton Stuart , Kelly John J. , Keenan Thomas W. 
Published: November 2006

AbstractThe location and origin of carotenoids in bovine milk fat globules was investigated using spectral absorption of lipid solutions at 461 nm to quantitate carotene. Release of membrane from globules as a result of churning to butter or by freezing and thawing of the globules yielded membrane preparations which were devoid of carotene. Globule cores from these procedures exhibited carotene concentrations comparable to those in total milk lipids. Fractionation of lactating bovine tissue and analysis of lipid extracts revealed that the intracellular fat droplets have carotene concentrations approximating those of secreted blobules. However, intracellular membranes of the tissue, particularly the mitochondria, are much richer in carotenoids than formative or secreted fat globules. The evidence indicates that bovine milk fat globules acquire carotene during their formation in the cell, but that some minor fraction of the total carotene may be extracted from the enveloping secretory membrane. Mean carotene values (μg/g of lipid) for fractions from three samples of lactating tissue were: whole tissue 47, mitochondria 461, microsomes 69, cytosol 67, fat droplets 8, milk 9. One tissue analysis indicated that Golgi membranes contain somewhat more carotene than do microsomes.
The effect of oral contraceptives on mononuclear cell cholesteryl ester hydrolase activity
Authors: Hagemenas F. C. , Yatsu F. M. , Manaugh L. C. 
Published: November 2006

AbstractThe influence of sex steroids on mononuclear cell cholesteryl ester hydrolase (CEH) activity in premenopausal women and women on combined estrogen‐progestin oral contraceptives has been studied. In addition, plasma and mononuclear cell cholesterol and esters were measured along with plasma estrogen and progesterone levels. Mononuclear cell CEH activity in control women is highest on Day 20 of their menstrual cycle. The control women had significantly higher CEH activities than women on oral contraceptives. Plasma esters were higher in the oral contraceptive group. However, in mononuclear cells free cholesterol but not cholesteryl esters were higher in women on oral contraceptives.
Sterols of scallop. III. Characterization of some C‐24 epimeric sterols by high resolution (220 MHz) nuclear magnetic resonance spectroscopy
Authors: Khalil M. W. , Idler D. R. , Patterson G. W. 
Published: November 2006

AbstractAlkyl sterols epimeric at C‐24 isolated from the Atlantic scallop,Placopecten magellanicus, were analyzed by high resolution (220 MHz) nuclear magnetic resonance spectrometry, and their spectra compared with authentic samples. This technique was used to assign absolute stereochemistry in epimeric mixtures of 24 R and S 24‐methylcholest‐5‐en‐3β‐ol, (22E)‐24‐methylcholesta‐5,22‐dien‐3β‐ol and 24‐ethylcholest‐5‐en‐3β‐ol. It also allowed a semiquantitative estimate of the R/S isomers present in the mixture.
Polar lipids ofMacrophomina phaseolina
Authors: Wassef Momtaz K. , Ammon Vernon , Wyllie T. D. 
Published: November 2006

AbstractMacrophomina phaseolina was grown on a defined medium at three different carbon/nitrogen ratios. The lipids of the mycelia and the sclerotia were extracted; fractionated into polarity groups; and separated by thin layer, column, and gas liquid chromatographies. Sclerotia contained higher levels of neutral lipids and lower amounts of polar lipids than mycelia. The neutral lipid content of sclerotia increased, up to 77% of total lipids, and phospholipids decreased as carbon/nitrogen ratio increased from 10 to 320. The glycolipid content was not altered significantly by changes in carbon/nitrogen ratios. Although cardiolipin could not be detected in sclerotial polar lipids, both sclerotia and mycelia contained similar phospholipid profiles with major quantitative differences. Phosphatidic acid and phosphatidyl glycerol were major components of sclerotia, whereas phosphatidyl ethanolamine and phosphatidyl inositol were the major phosphatides of mycelia. Phosphatidyl choline was present in both mycelia and sclerotia. The fatty acid distribution did not show any particular pattern of saturation or unsaturation due to differences in carbon/nitrogen ratio. However, mycelial lipids tended to contain C24∶1, C18∶3, and C22∶1 as major fatty acids, whereas the major fatty acids in sclerotial lipids were C18∶2, C18∶1, C22∶1, C20∶0, and C16∶1. Saturated fatty acids were present in lesser concentrations.
Hepatoma, host liver, and normal rat liver neutral lipids as affected by diet
Authors: Wood Randall , Falch John , Wiegand Rex D. 
Published: November 2006

AbstractGroups of normal and hepatoma (7288CTC) bearing rats were maintained on normal chow and fat‐free diets for 4 weeks. Normal liver, host liver, and hepatoma neutral lipids were examined in detail and compared. Water content, unaffected by diet was: hepatoma, 82%; host liver, 71%; and normal liver, 67%. The fat‐free diet had no effect upon the hepatoma neutral lipids but elevated the triglyceride level in normal and host liver, shifted the triglyceride carbon number distribution to lower mol wt, and elevated the percentage of monoenoic acids in triglycerides and cholesteryl esters. Host triglyceride concentrations were ca. half, and cholesterol levels were reduced moderately relative to normal liver values. Hepatoma cholesterol levels were higher and triglyceride concentrations lower than normal and host liver values. Hepatoma triglycerides differed dramatically from liver and were characterized by increased concentrations of high mol wt species and a fivefold increase in the percentage of C‐20 and C‐22 fatty acids. The percentage of C‐20 and C‐22 fatty acids in hepatoma cholesteryl esters also increased ca. fivefold relative to liver. The data indicate that the systems that regulate triglyceride and cholesteryl ester fatty acid composition in liver do not control the compositions of these lipid classes in this hepatoma. The unchanged high level of essential fatty acids in the hepatoma lipids from the fat‐free fed animals demonstrates the hepatoma's ability to absorb and conserve specific fatty acids.
Further studies on sphingolipids in wheat grain
Authors: Fujino Yasuhiko , Ohnishi Masao , Ito Seisuke 
Published: November 2006

AbstractThe principal molecular species of sphingolipids in wheat grain were confirmed to beN‐2′‐hydroxylignoceroyl‐4‐hydroxysphinganine for ceramide, and 1‐O‐β‐glucosyl‐, 1‐O‐[β‐mannosyl(1→4)‐O‐β‐glucosyl]‐, 1‐O‐[β‐mannosyl(1→4)‐O‐β‐mannosyl(1→4)‐O‐β‐glucosyl]‐and 1‐O[β‐mannosyl(1→4)‐O‐β‐mannosyl(1→4)‐O‐β‐mannosyl(1→4)‐O‐β‐glucosyl]‐N‐2′‐hydroxypalmitoyl (or hydroxyarachidoyl)‐cis‐8‐sphingenine for mono‐, di‐, tri‐ and tetraglycosylceramide, respectively. A novel glycolipid, cellobiosylceramide, was found as the minor diglycosylceramide; the major species was characterized to be 1‐O‐[β‐glucosyl(1→4)‐O‐β‐glucosyl]‐N‐2′‐hydroxypalmitoyl (or hydroxyarachidoyl)‐cis‐8‐sphingenine. It was observed in these sphingolipids that the dihydroxy bases were combined mainly with C16 and C20 acids, whereas the trihydroxy bases combined mostly with acids of chain length of 20 or more.
New long‐chain hydroxy acids fromGrevillea decora
Authors: Kleiman R. , Wolf R. B. , Plattner R. D. 
Published: November 2006

AbstractIn addition to the ω‐5 olefinic acids found in otherGrevillea species, about 10% of the acyl groups ofG. decora seed oil contain a hydroxy group and an ω‐5 double bond. The chainlengths of these acids are from C22 to C30, with the largest concentration at the C26 and C28 chainlengths. The hydroxy group is located on odd carbons from carbon‐5 through carbon‐13. These acids previously were unknown in nature. The most abundant of these are 7‐hydroxy‐cis‐17‐docosenoic, 7‐hydroxy‐cis‐19‐tetracosenoic, 9‐hydroxy‐cis‐19‐tetracosenoic, 9‐hydroxy‐cis‐21‐hexacosenoic, 11‐hydroxy‐cis‐21‐hexacosenoic, and 13‐hydroxy‐cis‐23‐octacosenoic acids. The oil also contains the largest known concentration of the unoxygenated C26 and C28 ω‐5 monoenes.