bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunochemical quantification of human plasma Lp(a) lipoprotein
Authors: Albers John J. , Hazzard William R. 
Published: November 2006

AbstractThe Lp(a) lipoprotein was purified from human plasma by ultracentrifugation and gel filtration on 6% agarose. It contained 27% protein, 65% lipid, and 8% carbohydrate. Quantification of the Lp(a) lipoprotein was performed by radial immunodiffusion. Both within‐assay and between‐assay coefficients of variation were inversely concentration dependent, decreasing from 20% and 27%, respectively, at 3 mg/100 ml to 7% and 12%, respectively, at concentrations above 8 mg/100 ml. The lower limit of sensitivity of the assay was 1.5 mg/100 ml. Of 340 unrelated fasting subjects tested, 81% had levels of the Lp(a) lipoprotein exceeding this lower limit. The distribution of Lp(a) concentrations in this population was skewed with a mean of 14 mg/100 ml and a median of 8 mg/100 ml. Lp(a) lipoprotein was not significantly correlated with age, sex, or cholesterol or glyceride concentrations.
Nutritional effects of partially hydrogenated low erucic rapeseed oils
Authors: Beare‐Rogers J. L. , Nera E. A. 
Published: November 2006

AbstractThe incidence of cardiac lesions in male rats fed rapeseed oil (Brassica campestris, cultivar ‘Span’) was lower with partially hydrogenated oil (iodine value 78) than with the liquid oil which had been treated in various ways. Another rapeseed oil (Brassica napus, cultivar ‘Tower’) was similarly improved when hydrogenated to iodine value 76.6, but not at iodine value 97.1, as demonstrated in both Sprague‐Dawley and Wistar rats. The improved nutritional quality of hydrogenated oil appeared not to be related to the decreased concentration of linolenic acid, because that fatty acid in linseed oil with or without erucic acid did not increase the incidence of lesions. A relatively high concentration of docosahexaenoic acid in the cardiac fatty acids was observed in adversely affected groups, but a lower concentration was found with the appropriately hydrogenated rapeseed oil.
Analytical13C NMR: Detection, quantitation, and positional analysis of butyrate in butter oil
Authors: Pfeffer P. E. , Sampugna Joseph , Schwartz Daniel P. , Shoolery James N. 
Published: November 2006

AbstractThe amount of butyrate contained in a complex mixture of butter oil triglycerides was 10.3 mole % as determined by natural abundance13C Fourier transform pulse nuclear magnetic resonance (NMR) spectroscopy. This NMR technique also demonstrated the primary isomeric positioning (>97%) of the butyrl group without the need for altering or fractionating the fat mixture.
Ether‐linked glycerolipids in human brain tumors
Authors: Albert Daniel H. , Anderson Carl E. 
Published: November 2006

AbstractIn this investigation, the lipid composition of a number of human brain tumors was determined and compared to that of normal adult brain. Glioblastomas (11 samples), astrocytomas (4 samples), an acoustic neurinoma, an oligodendroglioma, and a meningioma were analyzed. All of the tumors had substantial levels (0.8–3.4% of total phospholipids) of choline plasmalogen which was present in only trace amounts in normal brain. With the exception of the acoustic neurinoma and the meningioma, the concentration of alkylacylglycerophosphorylcholine was also higher in the tumors than in normal brain. Neutral lipids of brain tumors also contained high concentrations of both alkyl (1.6–4.8% of total neutral glycerolipids) and alkenyl diacyl glycerol (3.8–10.1%). The results from this investigation indicate that increases in etherlinked glycerolipids may be characteristic of human brain tumors.
The effect of lipids on taurocholate absorption from intestinal loops in the rat
Authors: Sklan D. , Budowski P. 
Published: November 2006

AbstractThe rates of uptake and serosal trans‐fer of [14C]‐labelled taurocholate (7.77 mM in bicarbonate buffer, pH 6.5) were determined in situ in ligated segments of rat intestine in the presence of lipids. Oleic acid, monoolein, lecithin, and lysolecithin enhanced taurocholate uptake and transfer in the jejunum, each lipid exhibiting and optimal concentration at which the bile acid fluxes were maximal. The maximal rates of bile acid uptake observed with the various lipids were close to four times the uptake rates found with the lipid‐free taurocholate medium, whereas serosal transfer rates under optimal conditions were enhanced about six‐fold. The optimal concentrations differed widely among the various lipids, being inversely related to the lipids' polarity. Simultaneous measurement of taurocholate and [3H]‐labelled oleic acid showed that under optimal conditions, when the molar concentration of oleic acid was about equal to that of the bile acid, the fatty aicd and bile acid also exhibited closely similar rates of absorption. At other fatty acid concentrations, the fractional rate of absorption of the bile acid was much lower than that of the fatty acid. The rates of uptake and serosal transfer of pure taurocholate by the ileum exceeded those of the jejunum by factors of about 7 and 15, respectively, but in the presence of lipids this difference in absorptive capacity for bile acid between the distal and proximal segment largely disappeared.
Involvement of cytochrome b5 in the oxidative desaturation of linoleic acid to γ‐linolenic acid in rat liver microsomes
Authors: Okayasu Takako , Ono Teruo , Shinojima Kazunori , Imai Yoh 
Published: November 2006

AbstractThe effects of antibodies against microsomal electron‐transport components on the in vitro activity of Δ6‐desaturation of linoleic acid to γ‐linolenic acid have been studied in intact microsomal membranes of rat liver. Reduced nicotinamide adenine dinucleotide (NADH) or reduced nicotinamide adenine dinucleotide phosphate (NADPH) (0.87 mM) served as electron donors, and effectively prompted the Δ6‐desaturase activities with yields of about 1.1 to 1.3 nmol per mg of protein in 10 min. Of the two antibodies studied under the same in vitro conditions, i.e., rabbit antisera preparations against rat liver microsomal hydrophilic parts of cytochrome b5 and NADPH‐cytochrome c reductase, only the antibody against cytochrome b5 demonstrated a marked ability to inhibit the Δ6‐desaturase activity. This evidence supports a participation of cytochrome b5 in the Δ6‐desaturation of linoleic acid and suggests a pathway analogous to the Δ9‐desaturation of stearyl‐CoA.
Changes in rat heart phospholipid composition after rapeseed oil feeding
Authors: Dewailly P. , Sezille G. , Nouvelot A. , Fruchart J. C. , Jaillard J. 
Published: November 2006

AbstractThe influence of long duration rapeseed oil feeding with high or low levels of erucic acid has been investigated on rat heart phospholipids. The rats treated for 20 wk with rapeseed oil containing 46.2% erucic acid showed a twofold increase in the sphingomyelin content of the heart. Treatment with primor rapeseed oil (3.7% erucic acid) for 20 wk did not modify phospholipid composition of rat heart. The fatty acid patterns of phosphatidylethanolamine and phosphatidylcholine were slightly influenced by the high erucic rapeseed oil; eicosenoic acid was incorporated preferentially into position one, but erucic acid showed a random distribution in both. After high erucic rapeseed oil feeding, 22∶1 was incorporated into cardiolipin (5.6%) and sphingomyelin (10.5%). The incorporation of 22∶1 into sphingomyelin was associated with an increase of the percentage of 24∶1 (14.6%) and a decrease of saturated long chain fatty acid (22∶0, 24∶0) percentages. Primor rapeseed oil caused a slight increase of 24∶1 and a decrease of 22∶0 and 24∶0 in rat heart sphingomyelin. As cardiolipin is localized in the inner membrane of mitochondria and sphingomyelin in plasma and microsomal membranes, the acyl‐moiety alterations of both phospholipids might be correlated to the pathological lesions of rat heart after a long duration of rapeseed oil feeding.
Sterol composition ofNeurospora crassa
Authors: Renaud R. L. , Subden R. E. , Pierce A. M. , Oehlschlager A. C. 
Published: November 2006

AbstractThe sterols extracted from freeze‐dried, log‐phase cultures ofNeurospora crassa were separated by thin layer and analyzed by capillary gas liquid chromatography and mass spectrometry. Ergosterol, episterol, and ergosta‐7,22 dienol were the major sterols of the free sterol fraction. The major esterified sterols, which constituted 4.95% of the total sterol fraction, were ergosterol, episterol, and ergosta‐ 7,22,24(28)‐trienol, with lesser quantities of 4α‐methyl‐ergosta‐8,24(28)‐dienol. With the exception of lanosterol, all sterols were alkylated at the C‐24 position.
Fatty acid metabolism of the calanoid copepodParacalanus parvus: 2. Palmitate, stearate, oleate and acetate
Authors: Moreno Victor J. , de Moreno Julia E. A. , Brenner Rodolfo R. 
Published: November 2006

AbstractThe de novo biosynthesis of fatty acids in the wild, calanoid copepodParacalanus parvus was studied. The incubation of labeled acetate proved the de novo biosynthesis of saturated and monounsaturated even fatty acids from 14 to 20 carbons and the 22∶1 acid. Saturated and monounsaturated uneven fatty acids from 15 to 21 carbons were also synthesized. The copepod could not synthesize linoleic and α‐linolenic acids. By administration of [1‐14C]palmitate, [1‐14C] stearate and [1‐14C]oleate, it was possible to elucidate the general pattern of the de novo biosynthesis of fatty acids in the wildP. parvus.
The use of essential fatty acid deficient rats to study pathophysiological roles of prostaglandins. Comparison of prostaglandin production with some parameters of deficiency
Authors: Parnham M. J. , Vincent J. E. , Zijlstra F. J. , Bonta I. L. 
Published: November 2006

AbstractIn a retrospective study on essential fatty acid deficient, (EFAD) rats used to study pathophysiological roles of prostaglandins (PGs) slight increases in the linoleic acid content of the diet were found to gradually restore the depressed growth rate and to increase the reduced endogenous PG production. These apparently poorly deficient animals had a serum triene tetraene (ω9:ω6) ratio much higher than the value of 0.4 used as a criterion for EFA deficiency by nutritionists. Changes in body weight, serum ω9∶ω6 and platelet PG production were not correlated with each other. Feeding rats on a diet containing <0.1 mg/g/linoleic acid led to decreasing platelet PG production as the degree of EFA deficiency increased. At this high level of deficiency, a serum ω9∶ω6 ratio of 6 or over was achieved. This high ratio may be taken as anindicator of the degree of EFA deficiency required for studies of PG deprivation, but PG production by the tissue investigated or by plalets should preferentially be measured.
Metabolism of linoleic acid in the cat
Authors: Sinclair A. J. , McLean J. G. , Monger E. A. 
Published: November 2006

AbstractCats fed a diet containing linoleate as the only polyunsaturated fatty acid showed extremely low levels of arachidonate in the plasma lipids, as well as an increase in linoleate, eicosadienoate and an unknown fatty acid. Administration of [1‐14C] linoleic acid and [2‐14C] eicosa‐8,11,14‐trienoic acid to cats showed that in the liver there was no conversion of the [1‐14C] 18∶2 to arachidonate, whereas there was significant metabolism of [2‐14C] 20∶3 to arachidonate. It was found when methyl‐γ‐linolenate was fed to cats that the level of 20∶3ω6 and 20∶4ω6 in the erythrocytes increased significantly. These results show that there is no significant Δ6 desaturase activity in the cat, whereas chain elongation and Δ5 desaturase enzymes are operative. The unknown fatty acid was isolated from the liver lipids and shown to be a 20‐carbon fatty acid with 3 double bonds and which by gas liquid chromatography could be separated from 20∶3ω9 and 20∶3ω6. The presence of the Δ5‐desaturase activity and the results of the ozonolysis studies indicated that this unknown fatty acid was eicosa‐5,11,14‐trienoic acid.
The formation of phosphatidylinositol by acylation of 2‐acyl‐sn‐glycero‐3‐phosphorylinositol in rat liver microsomes
Authors: Holub Bruce J. , Piekarski Jerry 
Published: November 2006

AbstractThe conversion of 2‐acyl‐sn‐glycero‐3‐phosphorylinositol into phosphatidylinositol via acyl‐CoA: 2‐acyl‐sn‐glycero‐3‐phosphorylinositol acyltransferase activity was found to occur in rat liver microsomes. Over a wide range of conditions, stearic acid was preferred over palmitate by the acyltransferase when these acids were presented in mixtures as acyl‐CoA derivatives. The potential importance of this enzyme activity for the entry of stearic acid into the 1‐position of hepatic phosphatidylinositol is further supported by its greater preference for stearate relative to the acyl‐CoA: 2‐acyl‐sn‐glycero‐3‐phosphorylcholine acyltransferase under certain assay conditions.
Hydroxy acids and estolide triglycerides ofHeliophila amplexicaulis L.f. Seed oil
Authors: Plattner Ronald D. , Payne‐Wahl Kathleen , Tjarks Larry W. , Kleiman Robert 
Published: November 2006

AbstractThirty percent of the fatty acids fromHeliophila amplexicaulis seed oil are hydroxy acids, primarily lesquerolic acid (14‐hydroxy‐cis‐11‐eicosenoic acid) with a trace of a new fatty acid, 16‐hydroxy‐cis‐13‐docosenoic acid. The hydroxy acids in the oil are found exclusively in the 1 and/or 3 positions of the triglycerides and are completely acylated with C20 or C22 saturated or monoenoic acids.
Hypolipidemic effects in monkeys of ML‐236B, a competitive inhibitor of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase
Authors: Kuroda Masao , Tsujita Yoshio , Tanzawa Kazuhiko , Endo Akira 
Published: November 2006

AbstractThe fungal metabolite ML‐236B, a competitive inhibitor of 3‐hydroxy‐3‐methylglutaryl CoA reductase, has been shown to be significantly effective in lowering serum cholesterol levels in cynomolgus monkeys at doses of 20–50 mg/kg per day. Levels of serum phospholipids and triglycerides were, however, not significantly changed by the administration of the drug. Of the serum lipoprotein fractions, a β‐lipoprotein corresponding to low density lipoprotein was preferentially reduced by the drug treatment. Fecal excretion of neutral sterols was unaffected but that of bile acids was slightly elevated by the administration of ML‐236B.
The adsorption of bile salts on activated carbon
Authors: Krasopoulos J. C. , De Bari V. A. , Needle M. A. 
Published: November 2006

AbstractActivated carbon (AC) has been shown to be effective in reducing serum cholesterol and triglycerides. The mechanism for this action is proposed to be a result of the removal of bile salts in the gut. In this paper, the adsorption of cholate, glycocholate, taurocholate, chenodeoxycholate and deoxycholate on AC is studied in vitro. The results indicate that AC has a high capacity for bile salts, completely removing them from solutions of up to 5 mM and at a rate consistent with physiological activity. Of the 2 types of AC tested, one was shown to exhibit greater capacity and selectivity over the other. A negligible effect was seen with variation of pH through the range 7–9. Desorption occurs in the presence of bile salt‐free buffer, but to a minimal extent. Based on these data, the adsorption of bile salts by AC appears to be a likely mechanism for AC‐induced reduction of serum lipids.
Sterol composition of ungerminated and germinated spores of the Vesicular‐Arbuscular Mycorrhizal fungus,Glomus caledonius
Authors: Beilby J. P. , Kidby D. K. 
Published: November 2006

AbstractThe sterol composition of spores of the Vesicular‐Arbuscular Mycorrhiza,Glomus caledonius, have been examined by combined gas liquid chromatography‐mass spectrometry (GLC‐MS). The sterols identified were cholesterol, 24‐methylcholesterol, 24‐methylenecholesterol and 24‐ethylcholesterol. The sterols 24‐methylcholesterol, 24‐methylenecholesterol and 24‐ethylcholesterol have not previously been reported as components of fungi in the Zygomycotina. The spores were germinated on agar and the major changes in sterol esters, free and bound sterols were studied over a period of 21 days. The total sterol content continually increased during the growth period; 24‐methylcholesterol and cholesterol were shown to be the major sterols.
Occurrence of plant sterols in aquatic vertebrates
Authors: Takagi Toru , Sakai Akira , Hayashi Kenji , Itabashi Yutaka 
Published: November 2006

AbstractPlant sterols were found by gas liquid chromatography in the sterols of five species of aquatic vertebrates; mackerel (Scomber japonicus), rainbow trout (Salmo gairdnerii), smelt (Osmerus dentex), sardine (Sardinops melanosticta) and chimera (Chimera phantasma). The sterols of chimera liver, sardine flesh and sardine viscera contained 9.0, 2.4 and 3.1% of C28 and C29 sterols in addition to 86.7, 96.6 and 95.2% of cholesterol. The occurrence of norcholestandienol, campesterol, β‐sitosterol and C28 stanol was shown by combined gas chromatography‐mass spectrometry. Sperm whale (Physeter catodon) sterols consisted of more than 99% cholesterol with only traces of 22‐dehydrocholesterol.
Analysis of autoxidized fats by gas chromatography‐mass spectrometry. IV. Soybean oil methyl esters
Authors: Frankel E. N. , Neff W. E. 
Published: November 2006

AbstractAn unusual isomeric distribution of hydroperoxides has been found in soybean oil esters oxidized at low levels (peroxide values below 50). The unexpectedly high concentration of the 12‐hydroperoxide isomer is in marked contrast to the isomeric composition of oxidized pure linolenate. The different isomeric hydroperoxides observed at low levels of oxidation may contribute through their decomposition to the unique flavor deterioration of soybean oil. Quantitative gas chromatographymass spectrometry (GC‐MS) used in this study provides for the first time an answer to the basic question of which hydroperoxides contribute to the state of oxidation of soybean oil. Results of GC‐MS were confirmed by capillary gas chromatography. Analyses of highly oxidized soybean esters (peroxide values 468 and 2352) reveal the same main compounds as those found in oxidized pure linoleate, together with small amounts of oleate and linolenate hydroperoxides.
The effect of essential fatty acid‐deficient diet on the levels of prostaglandins and their fatty acid precursors in the rabbit brain
Authors: Hassam A. G. , Willis A. L. , Denton J. P. , Stevens P. , Crawford M. A. 
Published: November 2006

AbstractRabbits were maintained on an EFA‐deficient diet. After eight weeks on this diet, lipid analysis showed no major alterations in the levels of brain dihomo‐gamma‐linolenic and arachidonic acids when compared with animals maintained on the standard laboratory diet. However, there were substantial reductions in the brain prostaglandin contents. It is suggested that the dihomo‐gamma‐linolenic acid and arachidonic acid utilized for prostaglandin production may be more directly related to the dietary essential fatty acid input rather than to the size of the precursor pool in the principal phospholipids.
Improved synthesis of choline phospholipids
Authors: Brockerhoff Hans , Ayengar Narayan K. N. 
Published: November 2006

AbstractCholine phospholipids (diether and dialkyl analogs of phosphatidyl choline, cholesteryl phosphocholine) were prepared, in yields of 72–83%, by condensation of the diglyceride analogs (or cholesterol) with phosphorusoxychloride and choline toluene‐sulfonate.
Effects of estrogens and progestins on high density lipoproteins
Authors: Krauss R. M. , Lindgren F. T. , Wingerd J. , Bradley D. D. , Ramcharan S. 
Published: November 2006

AbstractHigh density lipoprotein (HDL) levels are known to be higher in women than in men, and to increase with estrogen use. To assess the effects of estrogens on HDL subspecies, analytic ultracentrifuge measurements of HDL were compared in 11 menopausal estrogen users and 16 controls. The difference in mean schlieren patterns between the groups showed a significantly higher level of HDL with flotation rate (F1.20o)>1.5 (predominantly HDL2) in the users. This was similar to the difference in HDL seen between nonusers of hormones and age‐matched males. A previous study had shown that users of combination oral contraceptives had increased levels of HDL with F1.20o≤3.5 (primarily HDL3) suggesting that the estrogen effect on HDL is altered by the presence of added progestin. The progrestin effect was studied here in more detail in two women with type V hyperlipoproteinemia treated with norethindrone acetate. Reduction in serum triglyceride was accompanied by a reduction in HDL, predominantly in the less dense species (HDL2). Among groups of oral contraceptive and noncontraceptive estrogen and progestin users whose HDL‐cholesterol levels have been reported recently, there was a direct correlation (r=0.86, p<.001) between mean HDL‐cholesterol and triglyceride levels. Endogenous hormonal influences on HDL were assessed by serum hormone and lipoprotein measurements at weekly intervals during two consecutive menstrual cycles in four healthy females. An increase in HDL of highest flotation rate (F1.20o 5–9) was seen, which corresponded with the time of ovulation raising the possibility of pituitary as well as gonadal hormone effects on HDL.
Diet‐induced changes in the fatty acid composition of mouse hepatocyte plasma membranes
Authors: Hopkins G. J. , West C. E. 
Published: November 2006

AbstractHepatocyte plasma membranes were isolated from the livers of mice fed either a low fat diet or high fat diets containing polyunsaturated or saturated fat. The combined rate and isopycnic ultracentrifugation technique which was used produced highly purified hepatocyte plasma membrane fractions. The efficacy of the procedure was checked by electron microscopy and the assay of marker enzymes for the different subcellular organelles. Mice were maintained on a low fat diet until 60–70 days of age, when they were fed high fat diets containing polyunsaturated or saturated fat. The hepatocyte plasma membrane lipids of mice fed the polyunsaturated fat diet for 4 wk contained increased proportions of the major dietary unsaturated fatty acid, linoleic acid, and increased proportions of arachidonic acid. The proportion of linoleic and arachidonic acids decreased with continued feeding of the polyunsaturated fat diet. The hepatocyte plasma membrane lipids of mice fed the saturated fat diet contained increased proportions of oleic acid.
Antioxidants in neoplastic cells: I. Changes in the antioxidative capacity of mouse neuroblastoma cells measured by a single‐phase assay
Authors: Arneson Richard M. , Aloyo Vincent J. , Germain Glen S. , Chenevey James E. 
Published: November 2006

AbstractCultured mouse neuroblastoma cells exhibit a striking increase in antioxidative capacity during the transition from logarithmically dividing cells to nondividing, neurite‐bearing cells. Two physically separable phenomena are involved: (a) the membrane pellet of neurite‐bearing cells is highly resistant to lipid peroxidation, and (b) the postmicrosomal supernatant of these cells inhibits peroxidation in rat liver mitochondria and other biological membranes. A precise, single‐phase assay has been developed for assessing antioxidant levels in lipid extracts. By means of this assay, the increase in membrane resistance to lipid peroxidation has been correlated with a threefold increase in the antioxidant activity of the neuroblastoma neutral lipid fraction. This finding implies that generation of a neutral lipid antioxidant (or antioxidants) is involved in the profound increase in antioxidative capacity which occurs in differentiating neuroblastoma cells.