bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of trichloracetic acid‐phosphotungstic acid on the thin layer chromatographic mobility of gangliosides
Authors: Seyfried T. N. , Weber E. J. , Yu R. K. 
Published: November 2006

AbstractTrichloroacetic acid (TCA)‐phosphotungstic acid (PTA) precipitation has been used as a faster procedure than dialysis for the isolation of gangliosides, but the TCA‐PTA treatment causes striking abnormalities in the thin layer chromatographic mobilities of the gangliosides. However, a normal chromatographic pattern can be restored by treating the precipitated gangliosides with the tetrasodium salt of ethylenediamine tetraacetic acid followed by dialysis. Hence, TCA‐PTA treatment does not appear to cause artifacts or hydrolysis of the gangliosides.
Identification of positional isomers of lysophosphatides in butter serum
Authors: Cho B. H. S. , Irvine D. M. , Rattray J. B. M. 
Published: November 2006

AbstractThe separation of individual classes of phospholipids by two‐dimensional thin layer chromatography revealed the presence of lysophosphatides (monoacyl glycerophosphoryl compounds) in minor quantities in butter serum. The naturally occurring lysophosphatidyl ethanolamine (LPE) and lysophosphatidyl choline (LPC) were prepared by the combined use of a diethylaminoethyl (DEAE) cellulose column and thin layer chromatography. Gas chromatographic analysis of methyl esters of LPE and LPC showed that both lysophosphatides contained, in addition to saturated fattya cids, considerable quantities of unsaturated fatty acids. A comparison of the fatty acid pattern of naturally occurring LPE and LPC with that of LPE and LPC prepared by phospholipase A hydrolysis of phosphatidyl ethanolamine (PE) and phosphatidyl choline (PC) suggested that both the 1‐and 2‐forms of positional isomers were present. Hydrolysis of naturally occurring LPE and LPC with phospholipase C, and separation of the monoglycerides formed, confirmed the occurrence of two positional isomers of lysophosphatides.
Effect of polyunsaturated fatty acids of the α‐linolenic series on the development of rat testicles
Authors: Ayala Sixta , Brenner Rodolfo R. , Dumm César Gómez 
Published: November 2006

AbstractThe effect of 22∶6ω3 acid provided by dietary fish oil on the development of germinal tissue of rat testes, fatty acid composition of lipids, and linoleic or α‐linolenic acid Δ6 desaturation capacity was investigated. Results were compared to those obtained in animals fed methyl palmitate and sunflower seed oil (linoleate). At 7 and 9 weeks of age, development of germinal tissue of animals fed fish oil was normal. The fatty acid composition showed a decrease in 22∶5ω6 acid content and an increase in 22∶6ω3 acid in triacylglycerol, phosphatidylcholine, and phosphatidylethanolamine. The fatty acid Δ6 desaturation capacity of testicules microsomes was increased. It is suggested that 22∶6ω3 acid may functionally replace 22∶5ω6 acid in germinal tissue.
p‐Chlorophenoxyisobutyrate enhanced retention of homologous lipoproteins by human aortic smooth muscle cells
Authors: Filipovic Ivan , Buddecke Eckhart 
Published: November 2006

AbstractHuman aortic smooth muscle cells (SMC) specifically bind and take up indiscriminately both the lipid and protein moietics of homologous25I‐very low density lipoproteins (VLDL) and125I‐low density lipoproteins LDL). Sixty‐five to 80% of absorbed lipids are incorporated into the cell lipids, preferentially into the phospholipid fraction. Twenty to 35% of the lipid bound and the protein moiety are eliminated from the cells. Half of the eliminated protein label is recovered as TCA soluble products. Five mM of p‐chlorophenoxyisobutyrate (CPIB) raise the level of intracellular radioactivity derived from the lipid moieties of VLDL and LDL by about 40% via a reduced elimination. The processing of the protein moiety and lipoprotein binding to the cell surface are not affected by 5.0 mM of CPIB. CPIB lowers the incorporation of14C‐acetate,14C‐pyruvate, and32phosphate radioactivity into fatty acids and phospholipids of aortic SMC. Five mM of CPIB reduce the overall palmitic acid synthesis by shifting from de novo synthesis to the mechanism of chain elongation, although the further elongation to saturated C18–C24 fatty acids is also depressed. The CPIB‐enhanced retention of the lipid‐derived lipoprotein radio‐activity is interpreted as a compensatory mechanism providing cellular fatty acids which are deficient as a result of the CPIB inhibited synthetic processes.
Tissue lipid responses to 3‐hydroxy‐3‐methylglutaric acid with different dietary fats
Authors: Yousufzai S. Y. K. , Siddiqi Majid 
Published: November 2006

AbstractSimultaneous administration of 3‐hydroxy‐3‐methylglutaric acid (HMG) for 4 weeks to rats fed 20% saturated fats prevented rise of serum cholesterol, triglycerides, and phospholipids. Except phospholipids, other liver lipids were significantly decreased. HMG administration for 4 weeks along with atherogenic diet significantly decreased cholesterol and phospholipids of serum, liver, aorta, and heart. The phospholipids of epididymal fat and brain were also significantly lowered. The triglyceride levels in serum, liver, and epididymal fat were significantly decreased. The maximal hypolipidemic effect of HMG was observed in serum.
Glycerokinase in human adipose tissue
Authors: Ryall Rosemary L. , Goldrick R. B. 
Published: November 2006

AbstractThe presence of glycerokinase has been demonstrated in human omental and subcutaneous adipose tissue. The enzyme reaction showed a linear time course for 5 min at 30 C and pH optima at pH 7.6 and 9.0. Saturation of the enzyme was observed at 1.8 mM adenosine triphosphate (ATP) and the double reciprocal plot of activity vs. ATP concentration was nonlinear giving two apparent Km values of 0.094 and 0.518 mM. The apparent Km for glycerol, 0.112 mM, was obtained from a linear double reciprocal plot, and the enzyme was saturated at about 0.4 mM glycerol. The activity of glycerokinase in human adipose tissue excised under general anaesthesia was low and was unrelated to adipose cell size or the degree of obesity of the subject from whom the fat was obtained.
A comparison of simplified methods for lipoprotein quantification using the analytic ultracentrifuge as a standard
Authors: Lindgren F. T. , Silvers A. , Jutagir R. , Layshot L. , Bradley D. D. 
Published: November 2006

AbstractTwo simplified methods for quantitative lipoprotein analysis have been calibrated and compared with each other using analytic ultracentrifugation as a standard reference procedure. The first method was the Friedewald procedure and the second was an automated agarose gel electrophoresis system. Both procedures offer comparable quantitative lipoprotein analysis with potential for large scale screening purposes at low cost ($4.00–$5.00 per analysis). There were advantages and limitations to both procedures. The Friedwald procedure can be used on frozen sera but requires 3 ml sera. In contrast, the electrophoresis system must be used with fresh serum but requires only 50 μl serum and the electrophoretic slides may be quantitatively analyzed several years retrospectively.
Sterol composition and phytosterol utilization and metabolism in the milkweed bug
Authors: Svoboda J. A. , Dutky S. R. , Robbins W. E. , Kaplanis J. N. 
Published: November 2006

AbstractAnalysis of the sterols of the milkweed bug,Oncopeltus fasciatus (Dallas) and dietary sunflowerseeds revealed that there is little, if any, conversion of dietary C28 or C29 phytosterols to cholesterol in this phytophagous insect. The dietary sterols are apparently utilized with little alteration both during development to the adult stage and egg production, and cholesterol comprises <1% of the sterols in either adult males and females or in the eggs. The significance of these findings are discussed in light of the recent discovery that the C28‐ecdysone, makisterone A, is the predominant molting hormone in the enbryonated egg of the milkweed bug.
Measurement in vitro of the esterification of yeast sterols
Authors: Parks L. W. , Stromberg V. K. 
Published: November 2006

AbstractA highly reproducible and rapid procedure is described for isolating free sterols and sterol esters from cell‐free extracts of yeast. Using this technique, the sterol esterifying enzyme has been studied. Sterol ester hydrolase has also been demonstrated. In agreement with whole cell experiments, the enzyme activity for sterol ester synthesis has been found to increase on entrance of the culture into the stationary phase of growth.
Nutritional and metabolic studies of distillable fractions from fresh and thermally oxidized corn oil and olive oil
Authors: Gabriel H. G. , Alexander J. C. , Valli V. E. 
Published: November 2006

AbstractA semisynthetic diet containing 15% by weight of dietary fat was fed to six groups of male Wistar rats for 28 days. Two groups received the distilable fraction of fresh corn oil (DCO) or fresh olive oil (DOO), two groups the distillable fraction of the thermally oxidized fats (OCO,OOO), and two groups received the respective fresh fats as controls (FCO, FOO). Substantial changes in the fatty acid composition occurred in the fats upon thermal oxidation. Only the rats that received OOO showed overt symptoms of heated fat toxicity. This was reflected in the histological scores of these animals, with the liver sustaining the most numerous and severe lesions. Tissue fatty acid changes of any significance were confined largely to the polar liver lipids of the rats that were fed OCO or OOO. The results of this study would suggest that the relatively greater toxicity of OOO, compared to OCO, may in part be due to the high oleic:linoleic acid ratio of the fresh olive oil and in part to a higher tocopherol content of the corn oil.
Composition and synthesis of three higher ganglioside homologs in bovine mammary tissue
Authors: Bushway Alfred A. , Keenan T. W. 
Published: November 2006

AbstractThree higher gangliosides were identified as constituents of bovine mammary gland. The structures of these three gangliosides were shown to be ceramide‐glucose‐galactose‐(sialic acid)‐N‐acetylgalactosamine‐galactose, ceramide‐glucose‐galactose‐(sialic acid)2‐N‐acetylgalactosamine, and ceramide‐glucose‐galactose‐(sialic acid)2‐N‐acetylgalactosamine‐galactose These gangliosides accounted for only a small fraction (<20%) of the lipid‐bound sialic acid in mammary gland. While fatty acids with even carbon numbers from C14 to C26 were predominant in these gangliosides, they also contained C23 and C25 fatty acids. Mammary gland Golgi apparatus‐rich fractions had all glycosyltransferases required for synthesis of these gangliosides starting with ceramide.
Visualization of primate high density lipoproteins isolated by density gradient ultracentrifugation
Authors: Hojnacki Jerome L. , Nicolosi Robert J. , Llansa Norma , Hayes K. C. 
Published: November 2006

AbstractHigh density lipoproteins (HDL) isolated by density gradient ultracentrifugation from the plasma of monkeys ingesting semipurified diets are barely visible. This creates difficulty in separating HDL from other lower density lipoproteins following centrifugation and necessitates collecting large quantities of background density solution to insure complete recovery of the HDL fraction. A simple procedure is described involving the addition of β‐carotene to nonhuman primate plasma prior to centrifugation which results in the delineation of HDL as a discrete yellow‐orange band without affecting certain physical properties of HDL or interfering with standard lipid and protein assays.
Isotopic labeling of phosphatidylcholine in the choline moiety
Authors: Smith G. A. , Montecucco C. , Bennett J. P. 
Published: November 2006

AbstractTwo simple methods for the synthesis of phosphatidylcholine (lecithin) isotopically labeled in the methyl group of the choline moiety are described. Phosphatidylcholine is converted to phosphatidyl‐ethanolamine by enzymic transphosphatidylation, and this is methylated using either methyl iodide or diazomethane to give a product isotopically enriched in all three choline methyl groups.
Non‐methylene‐interrupted and ω4 dienoic fatty acids of the white shrimpPenaeus setiferus
Authors: Pearce Robert E. , Stillway Lewis W. 
Published: November 2006

AbstractThe total lipid fatty acids from the white shrimpPenaeus setiferus were found to contain several unusual dienoic fatty acid species. These included two methylene‐interrupted species: Δ11, 14‐C18∶2 (18∶2ω4) and δ13, 16‐C20∶2 (20∶2ω4). Also found were several non‐methylene‐interrupted dienoic fatty acids including δ7, 11 and Δ7, 13‐C20∶2, Δ7, 13‐C21∶2, Δ7, 13, Δ7, 15, Δ9, 13, Δ9, 15, and Δ7, 17‐C22∶2. Many minor C20∶2 non‐methylene‐interrupted dienes were found but could not be unequivocally characterized.
Glyceride metabolism in the myopathic hamster
Authors: Barakat Hisham A. , Tapscott Edward B. , Smith Carlton 
Published: November 2006

AbstractAnalysis of plasma lipids of 30‐ and 185‐day‐old BIO 82.62 myopathic hamsters and age‐matched normal controls revealed a decrease in only the concentration of cholesteryl esters of 185‐day‐old diseased animals. Measurement of lipoprotein lipase (LPL) activity in heart, muscle, and adipose tissue showed no difference between the activity of the enzyme in the heart and muscle of the cardiomyopathic hamsters and that of the age‐matched controls. In adipose tissue, however, LPL activity was depressed in the diseased animals in both age groups. No difference was found in the activity of hormone sensitive lipase. Incorporation of sn[U‐14C] glycerol‐3‐phosphate into total lipids was found to be depressed in homogenates of heart, muscle, and adipose tissue but unchanged in liver homogenates of diseased animals. It was concluded that the decrease in the capacity to synthesize glycerides, rather than limiting substrate concentrations, could be the cause of the decrease in the lipid content in some tissues of the cardiomyopathic hamster.
Changes in the fatty acid composition of rat lung lipids during development and following age‐dependent lipid peroxidation
Authors: Kehrer James P. , Autor Anne P. 
Published: November 2006

AbstractAnalyses of the fatty acid content and composition of various lung lipids were conducted in rats 1 day, 5 days, and 12 days after birth and in adult animals in order to define more clearly the specific lipid peroxidizing system found in neonatal rat lungs. Lipid peroxidation occurs in the 900×g supernatant fraction of rat lung homogenates in an age‐dependent manner independent of the addition of any factor and is maximal at 5 days of age. No lipid peroxidation is evident in similar preparations of either newborn or adult lung tissue. As the animals develop, arachidonic and docosahexaenoic acids, fatty acids which are both highly susceptible to lipid peroxidation in the presence of a suitable catalyst, decrease gradually when measured as the percentage of the total fatty acids in the triglyceride fraction of the lung. The total quantity of triglycerides, however, is significantly lower in lungs from 1‐day‐old rats than at any other age. The fatty acid composition and total quantity of both lung phospholipids and lung free fatty acids do not show similar changes. Following in vitro incubation of the 900×g supernatant fraction of peroxidizing lung homogenates, an appreciable decrease in the amount of arachidonic and docosa‐hexaenoic acid could be detected in lung triglycerides. Less extensive decreases were observed in the phospholipid fraction. No changes in these components were observed in newborn or adult animals. The addition of triarachidonin to the 900×g supernatant fraction of lung homogenates resulted in increased malondialdehyde release at all ages tested while added arachidonic acid increased the formation of malondialdehyde only in 5‐ and 12‐day‐old rat lung preparations. The addition of triolein, cholesterol arachidonate, and diarachidonyl phosphatidylcholine had no effect on malondialdehyde formation at any age. The age‐dependent lipid peroxidation observed after in vitro incubation of rat lung homogenate preparations, therefore, may result from the relatively high concentration of triglycerides containing polyunsaturated fatty acids present in the neonatal tissue. As the susceptible polyunsaturated fatty acids of lung triglycerides are replaced by less unsaturated species, this activity may diminish concomitantly.
Composition ofO‐alkyl andO‐alk‐1‐enyl moieties in the glycerolipids of the human adrenal
Authors: Lin Hsiang Ju , Lie Ken Jie M. S. F. , Hing Lee Clara Lai , Seng Lee Daniel Hong 
Published: November 2006

AbstractA comparison of human adult and fetal adrenals with respect to their levels of glyceryl ether lipids and other lipid components is reported. Fetal glands contained significantly lower levels of alk‐1‐enyl phosphoglycerides and of cholesterol. Neutral glyceryl ether diesters, and ethanolamine and choline phosphoglycerides were isolated from adult adrenal tissue. The composition of theO‐alkyl glycerol groups in these lipid fractions was obtained by means of gas chromatography of the trimethylsilyl ethers and diacetyl derivatives;O‐alk‐1‐enyl glycerols were analyzed as their diacetates. About one‐half of the alkyl and alk‐1‐enyl glycerol moieties present in glyceryl ether diesters contained hydrocarbon side chains with 20, 22, or 24 carbon atoms. Long hydrocarbon chains (C19–24) were also found in theO‐alkyl glycerol moieties present in the total lipids of fetal adrenals.
Mass spectrometric identification of C20 fatty acids bovine lens using the pyrrolidide derivative
Authors: Valicenti Anthony J. , Chapman Clifford J. , Holman Ralph T. , Chipault Jacques R. 
Published: November 2006

AbstractUnsaturated C20 fatty acids from bovine lens have been examined via gas chromatography‐mass spectrometry of their pyrrolidine derivatives. The presence of arachidonic acid and 5,8,11‐20∶3 in bovine lens has been confirmed by this study. In addition, the 10‐, 11‐, 12‐, and 13‐isomers of 20∶1 and the 7,13‐, 8,14‐, and 12,15‐isomers of 20∶2 were identified.
Studies on biosynthesis of waxes by developing jojoba seed tissue
Authors: Ohlrogge J. B. , Pollard M. R. , Stumpf P. K. 
Published: November 2006

AbstractSlices of developing jojoba cotyledons incorporated a variety of precursors in to wax, free alcohols, and polar lipids.14C‐Decanoic and14C‐lauric acids were elongated and desaturated, whereas14C‐myristic and14C‐longer chain fatty acids, although incorporated into wax, were insignificantly modified. Exogenously added14C‐acetate contributed mainly to chain elongation of endogenous oleic acid, whereas14C from added glucose was uniformly distributed throughout the acyl chain of the fatty acids. These data suggest the existence of metabolically separate pools of acetate and/or sites for de novo synthesis and elongation of acyl chains.
Changes in the cholesterol and phospholipid content of mouse spleen after Rauscher Leukemia Virus infection
Authors: Montfoort A. , Boere W. A. M. , Van Griensven L. J. L. D. 
Published: November 2006

AbstractThe effect of Rauscher Leukemia Virus (MuLV‐R) infection on the lipid composition of mouse spleen from BALB/c mice was investigated. Drastic changes in the lipid composition of the spleen as a result of tumor growth induced by the virus could be demonstrated at 21 days after infection. The molar ratio of cholesterol to phospholipids was found to be low, while a shift within the choline containing phospholipid classes resulted into a lower sphingomyelin and a higher phosphatidyl choline content of the MuLV‐R infected spleen. The cholesterol ester content increased more than two‐fold during tumor growth, and shifts in the fatty acid patterns of the lipids were demonstrated.
Retarding effects of DNA on the autoxidation of liposomal suspensions
Authors: Pietronigro Dennis D. , Seligman Myron L. , Jones W. Barrie G. , Demopoulos Harry B. 
Published: November 2006

AbstractDeoxyribonucleic acid (DNA) is associated with the cell membrane of prokaryotes and the inner nuclear membrane of eukaryotes. The unsaturated fatty acids of phospholipids, which constitute the bilaminar structure of membranes, undergo autoxidation in the presence of O2. Calf thymus DNA was incubated with methyl archidonate‐enriched phosphatidyl choline liposomes in order to study the effect of DNA upon the oxidation of phospholipids while present in their natural in vivo bilayer configuration. DNA retarded the rate of lipid oxidation and the TBA test, but it did not alter the induction period. These results suggest that DNA is scavenging free radicals produced within the phospholipid bilayer.
Blood sampling techniques for studying rapidly turning over metabolic fuels in mice
Authors: Baker Nome , Morris Daniel , Sandborg Christy 
Published: November 2006

AbstractExperiments were carried out in control and Ehrlich ascites carcinomatous mice to determine whether orbital venous sinus blood could be used to reflect blood in the systemic circulation (decapitation blood) in the case of a rapidly turning over metabolic fuel such as free fatty acids. The early time course of intravenously injected, labeled free fatty acids was measured using [9,10‐3H]palmitic acid and [1‐14C]linoleate complexed to mouse serum. No significant differences between decapitation and orbital sinus blood were found at early times in either group of mice. The orbital sinus clearly contains blood that is not stagnant and is replaced so rapidly that it is suitable for studying very rapidly turning over, circulating metabolites.
Influence of elevated levels of linoleic acid on the thermal properties of bovine milk fat
Authors: Morrison I. M. , Hawke J. C. 
Published: November 2006

AbstractThe thermal properties of bovine milk fat containing 15.5% linoleic acid have been compared with those of milk fat containing a normal level (1.8%) of linoleic acid in order to examine the influence of altered triglyceride (TG) composition on their physical characteristics. The total TGs of 18∶2‐rich milk fat melted over the range −38 to 30 C compared with the range −33 to 34 C for control milk fat. Polymorphism exhibited by the high mol wt TGs of control milk fat was absent in the same fraction of 18∶2‐rich milk fat. Similarly, the complex melting thermogram of the low mol wt TGs of control milk fat and its obvious polymorphic behavior contrasted with the single broad melting peak of the low mol wt TGs of 18∶2‐rich milk fat. This solid miscibility in the 18∶2‐rich milk fat could be a consequence of the lower proportion of saturated TGs or the presence of high proportions of diene and triene TGs containing 18∶2 instead of monoene and diene TGs containing 18∶1.
Effect of lecithin on jejunal absorption of micellar lipids in man and on their monomer activity in vitro
Authors: Ammon H. V. , Thomas P. J. , Phillipis S. F. 
Published: November 2006

AbstractThe effect of lecithin on jejunal absorption of fatty acids and octadecenoylglycerol was studied in healthy volunteers with a jejunal perfusion system which excluded pancreatic and biliary secretions from the test segment. Lecithin significantly reduced the absorption of oleic acid (P<0.05) and octadecenoylglycerol (P<0.01), while it had no effect on the absorption of ricinoleic acid. In vitro, lecithin reduced monomer activities of all three lipids; the changes were greater for oleic acid and octadecenoylglycerol than for ricinoleic acid (P<0.02). From these data it is concluded that lecithin reduces monomer activity of fatty acids in mixed micellar solutions and that it can thereby reduce the absorption rates of micellar lipids. Intact lecithin is not absorbed under these conditions. Maldigestion of lecithin in pancreatic insufficiency may, therefore, aggravate the steatorrhea observed in this condition.