bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diet‐induced alterations in the discoid shape and phospholipid fatty acid compositions of rat erythrocytes
Authors: Ananda Rao G. , Siler Kathleen , Larkin Edward C. 
Published: November 2006

AbstractFor eight weeks young male rats were fed diets rich in 18∶2 (stock diet, or 10% corn oil, CO) or those devoid of 18∶2 (fat free, FF, or 10% hydrogenated coconut oil, HCNO). The CO and HCNO diets were fed in the absence or presence of eicosa‐5,8,11,14‐tetraynoic acid (TYA). When 18∶2 was excluded, an increase in the level of 16∶1, 18∶1 and 20∶3 and a decrease in 18∶2 was observed in the fatty acids of red cells. On feeding TYA, an increase in 18∶2 and in the case of the HCNO+TYA diet, a decrease of 12∶0 and 14∶0 was also observed. In all cases the levels of 20∶4 in erythrocyte fatty acids were similar. Saturated fatty acids were predominant in phosphatidyl choline (PC), lysophosphatidylcholine, (LPC) and sphingomyelin whereas unsaturated acids were predominant in phosphatidyl ethanolamine (PE), (PS), and phosphatidyl inositol (PI). Acids containing three or more double bonds comprised about 90% of the total acids in PI. In all the phospholipids, the characteristic changes in the composition of fatty acids were observed due to the exclusion of 18∶2 from the diet. However, changes due to the feeding of TYA were found only in PC and LPC. In rats fed the 18∶2‐rich diet, about 60% of the red cells were discocytes. In those fed the 18∶2‐free diet, the level of discocytes decreased to about 23%, and the levels of echinocytes II and III increased. The exclusion of 18∶2 for even a few days decreased the proportion of discocytes. The loss of discoid shape was reversed in a few days by feeding an 18∶2‐rich diet. Fatty acid analysis of erythrocytes of rats of the various dietary manipulations showed that the change in the proportion of discocytes followed the change in the level of 18∶2.
Lactobacillic and methyl‐branched olefinic acids inByrsocarpus coccineus seed oil
Authors: Spencer Gayland F. , Payne‐Wahl Kathleen , Plattner Ronald D. , Kleiman Robert 
Published: November 2006

AbstractA detailed investigation of the seed oil ofByrsocarpus coccineus Schum. and Thonn. has disclosedcis‐11,12‐methyleneoctadecanoic (lactobacillic) (13%) and two branched octadecenoic acids (0.1%). Other fatty acids in the oil are those normally associated with seed lipids except for an unusually high proportion (12%) ofcis‐11‐octadecenoic acid. Lactobacillic acid has long been known as a constituent of certain bacterial lipids, but this is the first report of its presence in a seed oil. The branched olefinic acids have not heretofore been found to occur in plants.
Fatty acids and sterols ofCronartium fusiforme basidiospores
Authors: Weete J. D. , Kelley W. D. 
Published: November 2006

AbstractThe hydrocarbons, fatty acids, and sterols ofCronartium fusiforme basidiospores were examined by gas chromatography and mass spectrometry. Trace quantities of aliphatic hydrocarbons were detected, but these were probably not fungal products. Principal nonsubstituted fatty acids were palmitic (11.7%), linoleic (17.2%), and linolenic (16.1%) acids; the predominant acid was 9,10‐cis‐epoxyoctadecanoic acid (40.7%). Four sterols were detected, three of which were identified as stigmast‐7‐enol (57.6%), stigmasta‐5,7‐dienol (22.7%), and ergost‐7‐enol (16.0%). The fourth sterol (4%) is a C28 diene. Lipids of the aeciospores and basidiospores ofC. fusiforme are compared.
The distribution of dietary plant sterols in serum lipoproteins and liver subcellular fractions of rats
Authors: Sugano Michihiro , Morioka Hidekazu , Kida Yoshitaka , Ikeda Ikuo 
Published: November 2006

AbstractRats were fed plant sterols containing campesterol and β‐sitosterol in the different proportions, and their distribution in serum lipoproteins and in liver subcellular fractions was determined. In serum lipoproteins, the percentage as well as the concentration of plant sterols increased with the increase in the density of lipoproteins. Thus, high density lipoprotein (HDL) contained the highest and very low density lipoprotein (VLDL), the lowest. Also, there were distinct differences in the ratio of campesterol to sitosterol among lipoproteins, it was the highest in VLDL and lowest in HDL. Quantitatively, more than 75% of campesterol and 80% of sitosterol were carried in HDL; the values were significantly different from those of cholesterol (ca. 70%) in relation to total cholesterol. The distribution of plant sterols in liver subcellular fractions was virtually the same with that of cholesterol. Both nuclei and microsomes contained approximately 40% of total plant stetols.
The terpenyl pyrophosphates of wild type and tetraterpene mutants ofNeurospora crassa
Authors: Kushwaha S. C. , Kates M. , Renaud R. L. , Subden R. E. 
Published: November 2006

AbstractMutations to two albino loci ofNeurospora (al‐2 andal‐3) are known to block tetraterpene synthesis prior to phytoene but after farnesyl pyrophosphate. Analysis of the terpenyl pyrophosphates labeled with [214C] mevalonic acid revealed the presence of radioactive prephytoene, pyrophosphate in both albino mutants and in the corresponding wild type strain. Theal‐2 andal‐3 mutations are thus associated with lesions between prephytoene pyrophosphate and phytoene.
The effect of arylsulfonate esters on cholesterol‐aggravated atherosclerosis in white carneau pigeons
Authors: Macnintch John E. , Clair Richard W. St. , Lofland Hugh B. , Clarkson Thomas B. 
Published: November 2006

AbstractThe arylsulfonate esters of linoleyl, stearyl, and decyl alcohols were found to reduce significantly the accumulation of cholesterol in the plasma and livers of White Carneau pigeons subjected to a diet of Purina pigeon pellets coated with 0.25% cholesterol and 10% lard when fed for periods ranging from 9–12 months; no effects were observed in normocholesterolemic pigeons. These compounds produced no toxic side effects and were found to significantly attenuate the development of aortic atherosclerosis. The effect on aortic atherosclerosis was most likely the result of the lowering of plasma cholesterol concentrations. Linoleyl p‐toluenesulfonate appeared to be the most effective of the three arylsulfonates tested, both with respect to the reduction of plasma and liver cholesterol accumulation and attenuation of the atherosclerotic process.
Bile acid composition of rainbow trout,Salmo gairdneri
Authors: Denton J. E. , Yousef M. K. , Yousef I. M. , Kuksis A. 
Published: November 2006

AbstractThe bile acid composition and metabolism of rainbow troutSalmo gairdneri has been investigated by thin layer chromatography, gas liquid chromatography, and radio gas liquid chromatography methods. For this purpose gallbladder bile was collected from fed fish at 6 and 13 months and from starved fish at 12 months of age. Cholic acid was found to be the main component and constituted over 85% of total. Chenodeoxycholic acid accounted for 14% or less and the 3α, 12α‐7‐keto‐ and 7α, 12α‐3‐keto‐5β‐cholanoates for 1% or less of total. The bile acids were conjugated mainly with taurine, only small amounts of glycocholic acid being detected. Ca. 5% of the taurocholate was sulfated, as were trace amounts of cholic and glycocholic acids. The size of the bile acid pool was found to increase in the older fish and to decrease in starved fish. Unlike mammalian livers, the livers of the trout converted radioactive chenodeoxycholic acid into cholic acid.
Liver and serum lipids and lipoproteins of rats fed 5% L‐lysine
Authors: Hevia P. , Visek W. J. 
Published: November 2006

AbstractSoybean protein and casein supplemented with 1% Arg were compared for their ability to prevent fatty livers caused by excess dietary Lys. The concentrations of serum lipids and lipoproteins of rats fed 5% Lys and having vatty livers were also compared with those of rats fed the identical diet but lacking fatty livers when killed. The total liver lipids, triglycerides and cholesterol of rats fed 15% casein +5% Lys were 3.9, 12.4 and 2 times control values, respectively. Rats fed 5% Lys +1% Arg or 5% Lys with 15% soybean protein had liver lipid concentrations similar to controls fed no supplemental Lys. Serum total lipids, triglycerides, cholesterol, phospholipids and free fatty acids also did not change, and serum ketone bodies were slightly elevated with Lys feeding whether the rats had fatty livers or not. The concentrations of circulating HDL were slightly depressed in all rats fed 5% Lys while LDL were significantly elevated, particularly in rats without fatty livers. Serum VLDL did not change with 5% dietary Lys. Overall, excessive dietary Lys caused fatty livers which were prevented by varying the diet or length of feeding. Excess Lys feeding altered lipoprotein metabolism shown by decreased serum HDL and a substantial elevation in LDL. The latter was more apparent when the fat accumulation in liver was less severe or absent. The data suggest that the fatty liver from Lys excess is probably unrelated to increased fat mobilization from storage, decreased fat oxidation or to a major block in the transport of triglycerides from the liver to the circulation.
Lipid composition of SV40‐induced transplantable hamster tumor
Authors: Fallani A. , Ruggieri S. 
Published: November 2006

AbstractThe analysis of the lipid composition of the SV40‐induced transplantable hamster tumor has shown that: (a) the total phospholipid content in the tumor is lower than that usually found in normal tissues and similar to that reported for other neoplasms; (b) except for a lower percentage of diphosphatidylglycerol, the phospholipid composition is comparable with that reported for normal tissues; (c) the fatty acid profiles of the various glycerophospholipid classes are characterized by high proportions of oleic acid; and (d) phosphatidylethanolamine contains proportions of alkenyl side chains which are consistent with the amounts of plasmalogenic phospholipids found in other neoplasms.
Cholesterol interaction with recombinant human sterol carrier protein‐2
Authors: Colles S. M. , Woodford J. K. , Moncecchi D. , Myers‐Payne S. C. , McLean L. R. , Billheimer J. T. , Schroeder F. 
Published: November 2006

AbstractThe interaction of human recombinant sterol carrier protein‐2 (SCP‐2) with sterols was examined. Two independent ligand binding methods, Lipidex 1000 binding of [3H]cholesterol and a fluorescent dehydroergosterol binding assay, were used to determine the affinity of SCP‐2 for sterols. Binding analysis indicated SCP‐2 bound [3H]cholesterol and dehydroergosterol with aKd of 0.3 and 1.7 μM, respectively, and suggested the presence of a single binding site. Phase fluorometry and circular dichroism were used to characterize the SCP‐2 sterol binding site. Alterations in dehydroergosterol lifetime, SCP‐2 tryptophan lifetime, and SCP‐2 tryptophan quenching by acrylamide upon cholesterol binding demonstrated a shielding of the SCP‐2 tryptophan from the aqueous solvent by bound sterol. Differential polarized phase fluorometry revealed decreased SCP‐2 tryptophan rotational correlation time upon cholesterol binding. Circular dichroism of SCP‐2 indicated that cholesterol elicited a small decrease in SCP‐2 alpha helical content. The data suggest that SCP‐2 binds sterols with affinity consistent with a lipid transfer protein that may act either as an aqueous carrier or at a membrane surface to enhance sterol desorption.
Resistant starch is more effective than cholestyramine as a lipid‐lowering agent in the rat
Authors: Younes Hassan , Levrat Marie‐Anne , Demigné Christian , Rémésy Christian 
Published: November 2006

AbstractAmylase‐resistant starch (RS) represents a substrate for the bacterial flora of the colon, and the question arises as whether RS shares with soluble fibers common mechanisms for their lipid‐lowering effects. It is uncertain whether a cholesterol‐lowering effect depends basically on an enhanced rate of steroid excretion or whether colonic fermentations also play a role in this effect. In the present study, the effect of RS (25% raw potato starch), of a steroid sequestrant (0.8% cholestyramine), or both were compared on bile acid excretion and lipid metabolism in rats fed semipurified diets. RS diets led to a marked rise in cecal size and the cecal pool of short‐chain fatty acids (SCFA), as well as SCFA absorption; cholestyramine did not noticeably affect cecal fermentation. Whereas cholestyramine was particularly effective at enhancing bile acid excretion, RS was more effective in lowering plasma cholesterol (−32%) and triglycerides (−29%). The activity of 3‐hydroxy‐3‐methylglutaryl‐CoA reductase was increased fivefold by cholestyramine and twofold by RS. This induction in rats fed RS diets was concomittant to a depressed fatty acid synthase activity. In rats fed the RS diet, there was a lower concentration of cholesterol in all lipoprotein fractions, especially the (d=1.040−1.080) fraction high‐density lipoprotein (HDL1), while those fed cholestyramine had only a significant reduction of HDL1cholesterol. In contrast to cholestyramine, RS also depressed the concentration of triglycerides in the triglyceride‐rich lipoprotein fraction. There was no noticeable synergy between the effects of RS and cholestyramine when both were present in the diet. This suggests that the cholesterol‐lowering effect of RS is not limited to its capacity to enhance bile acids excretion. The difference between RS and cholestyramine could relate to the capacity of fermentation end‐products to counteract the upregulation of cholesterol and bile acid biosynthesis. Thus, in the absence of fermentation in the large intestine, a high rate of bile acids excretion is not always sufficient to elicit a cholesterol‐lowering effect.
Lipid oxidation: Biologic effects and antioxidants—A review
Authors: Logani M. K. , Davies R. E. 
Published: November 2006

AbstractThe detection and measurement of lipid oxidation in biological systems and some biologic effects of this oxidation are reviewed. The role of lipid oxidation in the process of photocarcinogenesis and the protective effect of antioxidants against this process also are discussed. The mechanism of such protection is unknown and studies directed at elucidating the mechanism of antioxidant effect in photocarcinogenesis and in some other pathological conditions believed to involve, lipid oxidation are needed. In addition to this, epoxidation of lipids observed in monolayer studies requires further investigation, particularly in the presence of some other unsaturated molecules. The possible significance of such a study—particularly in the presence of polycyclic aromatic hydrocarbon carcinogens, where formation of epoxides is generally accepted as active intermediates‐is also discussed. In addition, present knowledge on the role of lipid peroxides in the destruction of proteins and biomembranes, in chemically induced toxicity and in generation of singlet oxygen is presented.
Dealkylation of 24‐ethylsterols byTetrahymena pyriformis
Authors: Nes William R. , Alcaide Antonio , Mallory Frank B. , Landrey Josephine R. , Conner Robert L. 
Published: November 2006

AbstractWhenTetrahymena pyriformis was incubated with sitosterol ([24R]‐24‐ethylcholest‐5‐en‐3β‐ol]) or itstrans‐Δ22‐derivative (stigmasterol), the C‐24‐dealkylated product, cholesta‐5,7,trans‐22‐trien‐3β‐ol, was obtained in both cases. 24(S)‐24‐Ethylcholesta‐5,7,trans‐22‐trien‐3β‐ol also was found to be a metabolite. When sitosterol was the substrate, 24(R)‐24‐ethylcholesta‐5,7‐dien‐3β‐ol was obtained as a third product. Identifications were made by mass spectroscopy, quantitative chromatography, labeling with14C, and by other means. The dealkylated product (cholestratrienol) represented 30% of the sterols isolable after incubation. The administration of sterols to this organism did not induce sterol biosynthesis, since 2‐14C‐mevalonate failed to yield radioactive sterol in the presence of added stigmasterol.
New application of high pressure reversed‐phase liquid chromatography in lipids
Authors: Pei Patrick T‐S. , Henly Robert S. , Ramachandran S. 
Published: November 2006

AbstractHigh pressure reverse‐phase liquid chromatography has been used to separate saturated fatty acids, their methyl esters, polyunsaturated fatty acids, and triglycerides. Rapid separation of fatty acids differing in chain length and number of double bonds has been accomplished. Analysis time was less than 10 min in most cases. The high pressure reverse chromatography resulted in better separations of polyenoic acids than can be accomplished by conventional argentation silicic acid column chromatography. The analyses were carried out on a chemically bonded reverse phase packing, VYDAC reverse phase.
Comparative studies of triacylglycerol structure of very low density lipoproteins and chylomicrons of normolipemic subjects and patients with type II hyperlipoproteinemia
Authors: Myher J. J. , Kuksis A. , Breckenridge W. C. , McGuire V. , Little J. A. 
Published: November 2006

AbstractThe triacylglycerols of very low density lipoproteins (VLDL) and of chylomicrons were analyzed in the fasting and postabsorptive states from normolipemic subjects and patients with Frederickson's Type II hyperlipoproteinemia, who subsisted on free choice diets, standard diets excluding lard, or were given a breakfast enriched in lard. The VLDL and chylomicrons were obtained by conventional ultracentrifugation, and the triacylglycerols were isolated by thin‐layer chromatography (TLC). Representative sn‐1,2, 2n‐2‐3‐ and sn‐1,3‐diacylglycerols were generated by partial Grignard degradation of the triacylglycerols and a stereospecific hydrolysis by phospholipase C of the mixed sn‐1,2(2,3)‐diacyl phosphatidylcholines prepared as intermediates. Representative sn‐2‐acylglycerols were obtained by hydrolysis with pancreatic lipase. Positional distribution of the fatty acids was established by subtracting in turn the fatty acid composition of the sn‐2‐position from the fatty acid composition of the sn‐1,2‐ and sn‐2,3‐diacylglycerols. The molecular association of the fatty acids in the diacylglycerol moieties was determined by gas‐liquid chromatography with mass spectrometry (GC/MS) of the tertiary‐butyldimethylsilyl (t‐BDMS) ethers. The molecular association of the fatty acids in the triacylglycerols was determined by 1‐random 2‐random 3‐random calculation following experimental validation of the distribution. The results confirm a marked asymmetry in the positional distribution of the fatty acids in all triacylglycerol samples, with the palmitic acid predominantly in the sn‐1‐position, the unsaturated acids about equally divided between the sn‐2‐and sn‐3‐positions, and the stearic acid divided about equally between the sn‐1‐ and sn‐3‐positions. The overall structure of the VLDL and chylomicron triacylglycerols from patients and control subjects was characterized by a noncorrelative distribution of fatty acids under all dietary conditions.
Determination of the amounts of free arachidonic acid in resident and activated rabbit alveolar macrophages by fluorometric high performance liquid chromatography
Authors: Nakagawa Yasuhito , Waku Keizo 
Published: November 2006

AbstractAn improved method of high performance liquid chromatography (HPLC) has been developed for the separation and quantitation of low levels of free fatty acids as they occur in mammalian tissues. The fatty acid analysis is based on the esterification of the carboxylic group with 9‐anthryldiazomethane (ADAM). HPLC separation and fluorescence measurement of fatty acid ADAM esters allow the determination of pmole amounts of fatty acids.The amounts of free fatty acids of resident and activated alveolar macrophages were determined by the fluorometric HPLC method. There were approximately 2 μg/106 cells of free fatty acids. In resident macrophages, free 20∶4 was a minor component (0.8% of total free fatty acids), while significant amounts of 20∶4 were found in the total glycerophospholipids, representing 16.6% of the total fatty acids. A marked increase in amounts of 20∶4 (8 times) occurred in activated macrophages stimulated for 1 hr with opsonized zymosan. Small but significant increases (1.5 times) also occurred in other fatty acids. These results show that the release reaction of fatty acids was not selective for 20∶4 in alveolar macrophages after the challenge with opsonized zymosan.
Phosphorylation of chloroform soluble compounds in plasma membranes of human epidermoid carcinoma A431 cells
Authors: Brautigan David L. , Randazzo Paul , Shriner Carol , Fain John N. 
Published: November 2006

AbstractThis study investigated a possible role for the epidermal growth factor (EGF) receptor protein tyrosine kinase in phosphoinositide metabolism with plasma membrane vesicles from human epidermoid carcinoma (A431) cells. We found a novel chloroform‐soluble product radiolabeled with [gamma‐32P] ATP that did not migrate from the origin in the thin layer system designed to separate the phosphoinositides, appeared as a single band of Mr=3500 on polyacrylamide gels in the presence of dodecyl sulfate, had an ultraviolet absorbance spectrum with a maximum at 275 nm and stained with Coomassie dye. Based on these properties this phosphorylation product is referred to as a proteolipid. The32P label was not detected in phosphotyrosine [Tyr(P)], phosphoserine [Ser(P)] or phosphothreonine [Thr(P)] and was lost during acid or base hydrolysis. Phosphorylation of proteolipid was increased significantly by EGF, whereas phosphorylation of phosphatidic acid was decreased and labeling of phosphoinositides was unaffected. Thus, it appears that in A431 membranes the EGF receptor/ kinase does not utilize phosphatidylinositol as a substrate, but does phosphorylate a membrane proteolipid.
Biosynthesis and isomerization of 11‐hydroperoxylinoleates by manganese‐ and iron‐dependent lipoxygenases
Authors: Oliw Ernst H. , Cristea Mirela , Hamberg Mats 
Published: November 2006

AbstractManganese lipoxygenase (Mn‐LO) oxygenates linoleic acid (LA) to a mixture of the hydroperoxides—11(S)‐hydroperoxy‐9Z,12Z‐octadecadienoic acid [11(S)‐HPODE] and 13(R)‐hydroperoxy‐9Z,11E‐octadecadienoic acid [13(R)‐HPODE]‐ and also catalyzes the conversion of 11(S)‐HPODE to 13(R)‐HPODE via oxygen‐centered (LOO•) and carbon‐centered (L•) radicals [Hamberg, M., Su, C., and Oliw, E. (1998) Manganese Lipoxygenase. Discovery of a Bis‐allylic Hydroperoxide as Product and Intermediate in a Lipoxygenase Reaction, J. Biol. Chem. 273, 13080–13088]. The aims of the present work were to investigate whether 11‐HPODE can also be produced by iron‐dependent lipoxygenases and to determine the enzymatic transformations of stereoisomers of 11‐HPODE by lipoxygenases. Rice leaf pathogen‐inducible lipoxygenase, but not soybean lipoxygenase‐1 (sLO‐1), generated a low level of 11‐HPODE (0.4%) besides its main hydroperoxide, 13(S)‐HPODE, on incubation with LA. Steric analysis revealed that 11‐HPODE was enriched with respect to the R enantiomer [74% 11(R)]. In agreement with previous results, 11(S)‐HPODE incubated with Mn‐LO provided 13(R)‐HPODE, and the same conversion also took place with the methyl ester of 11(S)‐HPODE. 11(R,S)‐HPODE was metabolized biphasically in the presence of Mn‐LO, i.e., by a rapid phase during which the 11(S)‐enantiomer was converted into 13(R)‐HPODE and a slow phase during which the 11(R)‐enantiomer was converted into 9(R)‐HPODE. sLO‐1 catalyzed a slow conversion of 11(S)‐HPODE into a mixture of 13(R)‐HPODE (75%), 9(S)‐HPODE (10%), and 13(S)‐HPODE (10%), whereas 11(R,S)‐HPODE produced a mixture of nearly racemic 13‐HPODE (≈70%) and 9‐HPODE (≈30%). The results showed that 11‐HPODE can also be produced by an iron‐dependent LO and suggested that the previously established mechanism of isomerization of 11(S)‐HPODE involving suprafacial migration of O2 is valid also for the isomerizations of 11(R)‐HPODE by Mn‐LO and of 11(S)‐HPODE by sLO‐1.