bluuebunny/crossref_metadata_2025_split huggingface dataset:
cis‐Enediyne chromophore of isano oil
Authors: Miller Roger W. , Weisleder David , Plattner Ronald D. , Smith C. R. 
Published: November 2006

AbstractThe nonpolar fatty acids from isano oil have been reinvestigated to determine the source of the UV absorption long attributed to conjugatedcis‐enediyne groupings. Proton magnetic resonance and mass spectra of certain fractions supported the occurrence of such structures, but discrete compounds with this grouping were not isolated. Part of this ubiquituous UV absorption ascribed to enediyne was found to be due instead to the same conjugated diynones identified previously in the oxygenated acid fraction of isano oil. The structures of methyl octadeca‐9,11‐diynoate and methyl isanate were correlated with their proton magnetic resonance, (PMR), carbon‐13 magnetic resonance, and mass spectra.
Effects of cyanide on peanut lipoxygenase
Authors: St. Angelo Allen J. , Kuck James C. 
Published: November 2006

AbstractAcidic and alkaline lipoxygenase isozymes were separated and assayed for activity while incubated in the presence of various concentrations of cyanide. Inhibition due to cyanide per se was not found. Instead, cyanide caused an increase in pH, which decreased the activity of the acidic isozyme to a rate corresponding to the same pH on the activity curve for the cyanide‐free reaction.
Trans fatty acids: Positional specificity in brain lecithin
Authors: Karney Rona I. , Dhopeshwarkar Govind A. 
Published: November 2006

AbstractFifteen‐day‐old rats were divided into three groups: one group received an intracerebral injection of 5 μ Ci of 9‐trans, 12‐trans [1‐14C] octadecadienoic acid; the second group was given 5 μCi of the same compound plus an equal wt of nonradioactive allcis arachidonic acid; the third group was given 5 μCi of 9‐trans [1‐14C] octadecenoic acid. All animals were sacrificed 8 hr after injection. Glycerophosphocholine (GPC) was isolated and partically deacylated with phospholipase A2 fromCrotalus Adamanteus venom. The results of this study were as follows: 1) aftert [1‐14C] 18∶1 injection, there was twice as much radioactivity in the 1‐position as in the 2‐position; 2) whentt [1‐14C] 18∶2 was injected, more than 90% of the total radioactivity was found in the 2‐position; 3) followingtt[1‐14C]‐18∶2 +nonradioactive arachidonate injection, ca. 75% of the total radioactivity still remained in the 2‐position; and 4) all of the injected [1‐14C]‐tracers showed evidence of undergoing β‐oxidation to form acetyl‐CoA, which was converted to radioactive palmitate. The possibility is discussed that the observed distribution pattern of the injected radioactive tracers may be attributed to tissue metabolic specificity. Ramifications of the deposition of dietarytrans fatty acids in the brain during the developmental stage of the central nervous system are also discussed.
A comparative study of the lipid composition of isolated rat sertoli and germinal cells
Authors: Beckman J. K. , Coniglio J. G. 
Published: November 2006

AbstractThe lipid composition of enriched preparations of sertoli cells and of germinal cells, isolated from the testes of mature rats, has been investigated. Sertoli cells contained a much lower content of phospholipids (in particular, much less phosphatidylcholine and phosphatidylethanolamine) and a higher content of triacylglycerols than did germinal cells. In addition, the Sertoli cells had a higher ratio of esterified to unesterified cholesterol than did germinal cells. Total lipids of Sertoli cells contained considerably lower levels of palmitic and docosa‐4,7,10,13,16‐pentaenoic acids and higher levels of stearic and oleic acids than did the total lipids of germinal less palmitic and docosa‐4,7,10,13,16‐pentaenoic acids, more stearic and oleic acids and also more arachidonic acid than did the corresponding lipid classes of the germinal cells. Minor differences between cell types were also noted for the content of palmitoleic, linoleic, docosa‐7,10,13,16‐tetraenoic, docosa‐4,7,10,13,16,19‐hexaenoic and tetracosa‐9,12,15,18‐tetraenoic acids.
Sterols and fatty acids ofEpifagus virginiana, a nonphotosynthetic angiosperm
Authors: Nes W. David , Patterson Glenn W. , Southall M. Anne , Stanley June L. 
Published: November 2006

AbstractThe sterol and fatty acid compositions ofEpifagus virginiana, which is a nonphotosynthetic flowering plant, have been examined by combined gas liquid chromatography‐mass spectrometry (GLC‐MS) and nuclear magnetic resonance (NMR). The organism exhibited a typical higher plant Δ5‐sterol profile with the C‐24 alkyl group oriented “α” for the major sterol Trace amounts of 24‐methylenecycloartanol and cycloeucalenol established connection with the first cyclic intermediate (cycloartenol) in photosynthetic plant sterol biosynthesis. In a separate in vitro experiment, excised root and stem tissue were incubated with two labeled triterpenoid precursors, [2‐3H] lanosterol and [2‐3H]cycloartenol. Both the radioactive compounds were converted to labeled [3H]sitosterol indicating the presence of an active biosynthetic pathway inEpifagus. Characteristic photosynthetic higher plant fatty acids were also present, and the polyenic acid was identified as α‐linolenic acid.
Metabolism of naphthenic hydrocarbons. Utilization of a monocyclic paraffin, dodecylcyclohexane, by rat
Authors: Tulliez Jacques E. , Bories Georges F. 
Published: November 2006

Abstract3H‐Dodecylcyclohexane was incorporated in rat diet in order to study the metabolic utilization by mammals of a monocycloparaffin chosen as a typical naphthenic constituent of mineral oils. Dodecylcyclohexane was largely absorbed. No elimination of the hydrocabon was observed in urine while an extended excretion of3H occurred via this route. About 7% of absorbed dodecylcyclohexane was stored in the carcass, while the rest was ω‐oxidized to cyclohexyldodecanoic acid, which incorporated into neutral lipids and phospholipids. The aliphatic chain of this unusual fatty acid underwent the normal fatty acid degradation pathways, leading to even fatty acids, squalene, cholesterol and nonlipid resynthesis, while the cyclohexyl ring was eliminated as urinary metabolites. Incorporation of ω‐cyclohexyl fatty acids in phospholipids may raise a point of toxicological significance which is to be investigated.
Distribution of hydrocarbons in bovine tissues
Authors: Lintas C. , Balduzzi A. M. , Bernardini M. P. , Di Muccio A. 
Published: November 2006

AbstractLiver, heart, kidneys, muscle and adipose (perirenal and subcutaneous) tissues were collected from six animals for analysis of their hydrocarbon composition. Qualitative and quantitative determinations were carried out by gas chromatography and combined gas chromatography‐mass spectrometry. Although differing in the proportions, a homologous series of n‐alkanes ranging from n‐C12 to n‐C31 was found in all the samples examined. The isoprenoid hydrocarbons phytane and phytene (phyt‐1‐ene and phyt‐2‐ene) were also identified.
Reaction of thiobarbituric acid with saturated aldehydes
Authors: Kosugi Hiroko , Kikugawa Kiyomi 
Published: November 2006

AbstractThe reaction of thiobarbituric acid (TBA) with saturated aldehydes, i.e., 1‐butanal, 1‐hexanal and 1‐heptanal, produced a 455‐nm yellow and a 532‐nm red pigment. Formation of the pigments depended on the reaction conditions. The yellow pigment was unstable in the presence of excess amounts of the saturated aldehydes. The red pigment was formed only when the reaction was performed at a TBA/aldehyde ratio of 1∶1 in aqueous acetic acid. Formation of the yellow and red pigments required molecular oxygen. The colorless adducts, intermediates for the yellow and the red pigments, were isolated from the reaction mixtures. Aldol condensation and dehydration of 2 mol of the saturated aldehydes initially gave the α,β‐unsaturated aldehydes, which in turn reacted with TBA to form the colorless adducts, pyranopyrimidine derivatives. The adducts were then converted into the yellow and red pigments under aerobic conditions.
Absorption and distribution of deuterium‐labeledtrans‐ andcis‐11‐octadecenoic acid in human plasma and lipoprotein lipids
Authors: Emken E. A. , Rohwedder W. K. , Adlof R. O. , DeJarlais W. J. , Gulley R. M. 
Published: November 2006

AbstractTriglycerides of deuterium‐labeledtrans‐11‐,trans‐11‐cis‐11‐ andcis‐9‐octadecenoic acid (11t‐18∶1‐2H, 11c‐18∶1‐2H) were simultaneously fed to two young adult male subjects. Plasma lipids from blood samples collected periodically for 48 hr were analyzed by gas chromatography‐mass spectroscopy. The results indicate (i) the Δ11‐18∶1‐2H acids and 9c‐18∶1‐2H were equally well absorbed; (ii) relative turnover rates were higher for the Δ11‐18‐1‐2H acids in plasma triglycerides; (iii) incorporation of the Δ11‐18∶1‐2H acids into plasma phosphatidylcholine was similar to 9c‐18∶1‐2H, but distribution at the 1‐and 2‐acyl positions was substantially different; (iv) esterification of cholesterol with 11t‐18∶1 was extremely low; (v) chain shortening of the Δ11‐18∶1‐2H acids was 2–3 times greater than for 9c‐18∶1‐2H; (vi) no evidence for desaturation or elongation of the 18∶1‐2H acids was detected; and (vii) a 40% isotopic dilution of the 18∶1‐2H acids in the chylomicron triglyceride fraction indicated the presence of a substantial intestinal triglyceride pool. Based on our present knowledge, these metabolic results for Δ11‐18∶1 acids present in hydrogenated oils and animal fats indicate that the Δ11 isomers are no more likely than 9c‐18∶1 to contribute to dietary fat‐related health problems.
Correlation between skeletal muscle free fatty acid extraction and vascular decompensation during hemorrhagic hypotension
Authors: Bond Robert F. , Zepp Andrew , Peissner Lorraine C. , Manning Eva S. 
Published: November 2006

AbstractThe objective of this study was to determine whether or not a relationship exists between free fatty acid (FFA) extraction by skeletal muscle and onset of irreversible shock. Hind limb skeletal muscle vasculature of anesthetized dogs was surgically isolated from cutaneous tissue and subjected to a modified Wigger's hemorrhage shock protocol which was divided into five stages (I−V). Since the first signs of irreversibility began in Stage II, this stage of hypovolemic hypotension was subdivided into IIa, IIb and IIc. Arterial and venous blood samples were taken during each stage for subsequent blood gas and FFA analysis. The data indicated that the onset of severe tissue ischemia and metabolic acidosis occurs concurrently with increased uptake of FFA and skeletal muscle vasodilation (decomposition). A possible physiological explanation for these observations could be related to an increased synthesis and release of PGE1. This agent has been shown by others to inhibit adrenergic neurotransmitter release causing loss of vascular tone.
Membrane lipids in bromodeoxyuridine‐differentiated astroglial cells in culture
Authors: Robert J. , Mandel P. , Rebel G. 
Published: November 2006

AbstractEmbryonic hamster astroblasts (NN strain) grown in continuous line were cultivated in the presence of bromodeoxyuridine (BrdU). A decrease in the growth rate of the cells and striking changes in their morphology were observed, the morphology of the cells resembling that of mature astrocytes. Membrane lipids of BrdU‐differentiated and standard cells were compared. No modification of the lipid/protein ratio was observed. Phospholipids and cholesterol were increased in the same proprotions in the cells, and no modification of the phospholipid distribution was observed. Ganglioside sialic acid remained at the same level, but the ganglioside distribution was highly modified. Complex gangliosides appeared (GM1 and GD1a), while the proportion of simple gangliosides (GM3 and GD3) decreased. However, neither GT1 nor GQ1 were detected in differentiated cells. The distribution of phosphoglyceride acyl groups was highly modified, the proportion of arachidonic and docosapentaenoic acids being 2 to 3 times higher in BrdU‐treated cells than in proliferating ones. These results were compared to those obtained with another clonal line of glial cells (C6) which exhibited no morphological differentiation in the presence of BrdU; the lipids of these cells were not modified by such a treatment.
Composition of wax esters and triacylglycerols in the melon and blubber fats of a young Sowerby's whaleMesoplodon bidens
Authors: Lok C. M. , Folkersma B. 
Published: November 2006

AbstractThe blubber fat of a yearling Sowerby's Whale,Mesoplodon bidens, stranded on the Dutch coast, contained 59% triacylglycerols. This is quite unexpected because low levels (0–6%) of triacylglycerols are characteristic ofZiphiidae whales. In addition, the chain lengths of the fatty acids of the melon were longer than those of previously studied related species. As young Sowerby's Whales undergo a change in diet from mainly triacylglycerols in milk to wax ester containing food during their development from infancy to independence, these findings could reflect the age of the animal.
Composition of plasma and nascent very low density lipoprotein from perfused livers of hypercholesterolemic squirrel monkeys
Authors: Nicolosi R. J. , Hayes K. C. 
Published: November 2006

AbstractThe composition of circulating very low density lipoprotein (VLDL) was compared with the composition and secretion of nascent VLDL from perfused livers of squirrel monkeys that were fed unsaturated or saturated fat diets to elicit different degrees of plasma hypercholesterolemia. All squirrel monkeys studied had cholesteryl ester‐rich plasma VLDL, although greater enrichment occurred in hypercholesterolemic animals fed saturated fat. Livers from hypercholesterolemic animals were capable of secreting VLDL particles enriched in cholesteryl ester, suggesting hepatic origin for a portion of this circulating lipid moiety. Total VLDL lipid, but not protein output by perfused livers of hypercholesterolemic monkeys, was greater than that by livers from hypocholesterolemic animals. These results indicate that saturated fat‐induced hypercholesterolemia is associated with changes in the composition of hepatic VLDL in the squirrel monkey.
Inhibition of rat hepatic sterol formation from squalene by plasma lipoproteins
Authors: Srikantaiah M. V. , Lew D. W. , Morin R. J. 
Published: November 2006

AbstractThe conversion of3H‐squalene to sterols by rat liver microsomes and cytosol was inhibited by individual rat and human plasma lipoproteins at various concentrations. This inhibition was also observed with added human high density apolipoprotein, but triglycerides, cholesterol or cholesteryl esters had no inhibitory effects. Lipoproteins and apo high density lipoprotein (HDL) were demonstrated to bind3H‐squalene in vitro. The binding of3H‐squalene by apo HDL could be reversed by increasing concentration of liver cytosol containing sterol carrier protein.
The use of 13‐methyltetradecanoic acid as an indicator of adipose tissue turnover
Authors: Klein Roger A. , Halliday David , Pittet Philippe G. 
Published: November 2006

AbstractWe show in this paper that 13‐methyltetradecanoic acid (13‐MTD) can be used as a structurally labeled marker for investigating the mobility of fatty acyl chains in adipose tissue in the rat. The presence of an ω‐1 methyl group allows easy quantitation by gas liquid chromatography (GLC) and permits an assessment to be made of any oxidation and chain elongation reactions with reincorporation of the label into the adipose tissue, since the iso‐acyl chain is well resolved from odd or even‐numbered homologous fatty acids with straight chains. The kinetics of uptake and loss of the structural label were different for adipose tissue taken from the various sites which were sampled, namely post abdominal, mesenteric, perirenal, pericardiac and subcutaneous adipose tissue as well as the epidydimal fat pads. We also report preliminary results in man which confirm that the method is applicable to human clinical studies and that 13‐MTD kinetics differ for adipose tissue taken from the 3 different subcutaneous sites‐waist, arm and thigh.
Quantitative analyses of hydroxystearate isomers from hydroperoxides by high pressure liquid chromatography of autoxidized and photosensitized‐oxidized fatty esters
Authors: Neff W. E. , Frankel E. N. 
Published: November 2006

AbstractA high pressure liquid chromatography (HPLC) method is described for the determination of the isomeric hydroxysterates from hydroperoxides of oxidized fatty esters. The samples are hydrogenated and the mixtures of hydroxystearates are concentrated by partial removal of unoxidized esters and complete removal of polar materials. Isomeric hydroxystearates are then separated on a porous microparticulate adsorption (10 μ) column and elution with 0.25% isopropyl alcohol inn‐hexane is monitored at 212 nm. The 8‐OH, 9‐OH, 10‐OH, 11‐OH and 16‐OH isomers were completely separated, but the 12‐OH, 13‐OH and 15‐OH were only partly resolved by HPLC. The relative percentages of isomeric hydroxy esters were analyzed quantitatively by a computer integration method. Accuracy of the method was checked with known mixtures of synthetic hydroxystearates. The isomeric hydroperoxide composition of oxidized methyl oleate, linoleate, linolenate and soybean methyl esters determined by HPLC were in good agreement with previous analyses by gas chromatography‐mass spectrometry.
Species variation in serum levels of prostaglandins and their precursor acids
Authors: Hwang D. W. , Godke R. A. , Rings R. W. 
Published: November 2006

AbstractLevels of prostaglandin (PG) precursor acids, and PGE2, PGF2α and TXB2 in sera of adult animals (5/species) were determined by gas chromatography and radioimmunoassay, respectively. The level of arachidonic acid in horse serum lipids was the lowest (0.61±0.03%), and that in dog serum lipids was the highest (18.1±1.8%). Bovine serum lipids contained considerable amounts of 20∶3ω6 (precursor of monoene PG) and 20∶5ω3 (precursor of triene PG) in addition to arachidonic acid. Thromboxane B2 was not the major species of endoperoxide metabolite synthesized by platelets from arachidonic acid in male ruminants and pig. The concentration of TXB2 in the serum of the lactating cow was more than 50 times greater than that of ovariectomized cows or of bulls. Although TXB2 was the major species of endoperoxide metabolite synthesized by human platelets, its serum concentration was much lower than that of nonruminant animals except the pig. These results showed that there were considerable variations in levels of PG and their precursors among various species of animals. The species variation in PG and TXB2 concentrations was not simply attributed to the differences in platelet concentration blood.
Effects of different dietary intake of essential fatty acids on C20∶3ω6 and C20∶4ω6 serum levels in human adults
Authors: Lasserre M. , Mendy F. , Spielmann D. , Jacotot B. 
Published: November 2006

AbstractFour diets which differed in fatty acid composition were provided for five months each to a group of 24 healthy nun volunteers. The diets contained 54% carbohydrates, 16% proteins and 30% lipids. One‐third of the lipid part remained unchanged during the whole study, and two‐thirds were modified during each period. For this latter portion, one of the following dietary fats was used: sunflower oil, peanut oil, low erucic acid rapeseed (LEAR) oil or milk fats. This procedure allowed an evaluation of the effects of various amounts of dietary linoleic acid (C18∶2ω6) and alpha‐linolenic acid (C18∶3ω3) on the serum level of their metabolites. A diet providing a large amount of linoleic acid (14% of the total caloric intake) resulted in low levels of dihomo‐gamma‐linolenic acid (C20∶3ω6) and arachidonic acid (C20∶4ω6) in serum phospholipids and cholesteryl esters. A diet providing a small amount of linoleic acid (0.6% to 1.3% of the total caloric intake) induced high levels of ω6 fatty acid derivatives. Intermediate serum levels of C20∶3ω6 and C20∶4ω6 were found with a linoleic acid supply of about 6.5% of the total caloric intake. Serum levels of ω6 metabolites were not different after two diets providing a similar supply of C18∶2ω6 (4.5% to 6.5% of the total caloric intake), although in one of them the supply of C18∶3ω3 was higher (1.5% for LEAR oil versus 0.13% for peanut oil).Under our experimental conditions (healthy human adults fed on a normo‐caloric diet with 30% lipids), we tried to determine PUFA (linoleic and linolenic acid) allowances which should be recommended for adults. The aim of the study was to obtain a hypocholesterolemic or normocholesterolemic effect while keeping normal 20∶3ω6 and 20∶4ω6 serum levels which would evidence a normal linoleic acid metabolism. The amounts recommended are: linoleic acid 5 to 6% of the total calories; alpha‐linolenic acid 0.5 to 1% of the total calories.
Hydrolysis of 4‐methylumbelliferyl butyrate: A convenient and sensitive fluorescent assay for lipase activity
Authors: Roberts Ingram M. 
Published: November 2006

AbstractA rapid, sensitive and convenient fluorescent assay was developed to screen for lipase activity. The non‐fluorescent substrate, 4‐methylumbelliferyl butyrate (4‐MUB), solubilized in either liposomal dispersions or bile salt/lecithin mixed micelles, is hydrolyzed to butyric acid and the highly fluorescent compound, 4‐methylumbelliferone (4‐MU). Assays are run at 37 C for 10 min, terminated, and the changes in fluorescence quantitated with a Turner III fluorometer. Both lingual and pancreatic lipases exhibit activity against this artificial substrate. The assay has several advantages: nmoles 4 MU/ml/hr are measured allowing the detection of very low lipolytic activity; multiple samples may be simultaneously assayed, and only a brief incubation period is required.
Pulmonary lipid peroxides and fatty acids of rats fed different lipids and exposed to oxygen at hyperbaric pressure
Authors: Alam Syed Q. , Alam Bassima S. 
Published: November 2006

AbstractSemipurified diets containing different lipids were fed to rat dams during lactation and subsequently to their pups for 33 weeks post‐weaning. Some rats within each group were exposed to oxygen at hyperbaric pressure (OHP). Lipid peroxide levels were lower in lungs of rats fed 7% hydrogenated coconut oil or 10% butter as compared with their controls, fed 7% corn oil or 10% safflower oil, respectively. Exposure to OHP increased lung peroxide levels. This increase varied with the type of fat in the diet. Studies of the fatty acid composition indicate that lipid peroxide levels generally increased with an increase in the levels of 18∶2 in lung total lipids. The results suggest that the type of dietary lipid may alter the susceptibility of the animal to pulmonary oxygen toxicity.
Increases in serum sphingomyelin by 17β‐estradiol
Authors: Merrill Alfred H. , Wang Elaine , Innis Wendy S. A. , Mullins Richard 
Published: November 2006

AbstractThe effects of estrogens on plasma sphingomyelin and the hepatic activity of the initial enzyme of sphingomyelin synthesis were examined using immature chicks. After three days of 17β‐estradiol administration, serum sphingomyelin, total phospholipids, and cholesterol doubled, and triacylglycerol levels increased 7.5 fold. The sphingomyelin content and percentage of total phospholipids of liver were unaffected by estrogen treatment. The specific activity of serine palmitoyltransferase (EC 2.3.1.50) was unchanged, but the total activity appeared slightly higher due to increased liver weights. The higher spingomyelin may, therefore, be due less to increased levels of biosynthetic enzymes than to factors such as the substrate (i.e., fatty acid) supply or decreased clearance of plasma sphingomyelin. These results are similar to earlier findings with key enzymes of cholesterol and glycerolipid biosynthesis and suggest that the three lipid pathways may be coordinated during estrogen treatment and enhanced very‐low density lipoprotein (VLDL) synthesis.