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PubMed1981

Sensitization to olive oil (olea europeae).

Sensitization to olive oil is seldom reported in the literature. By use of epicutaneous tests a delayed type of hypersensitivity to pure freshly-prepared olive oil could be demonstrated in two patients. Patch tests with certain major constituents of olive oil; the methyl ester of linoleic acid, the glyceryl ester of palmitic acid, the glyceryl ester of stearic acid, glyceryl trioleate and glycerids of arachidic acid, appeared to be negative. In one patient a weak reaction to balsam of Peru was found. It is concluded that sensitization to olive oil must be taken into consideration, especially when it is used as a vehicle in patch testing.

Aged↗
PubMed2003

Ethanol tolerance in the yeast Saccharomyces cerevisiae is dependent on cellular oleic acid content.

In this investigation, we examined the effects of different unsaturated fatty acid compositions of Saccharomyces cerevisiae on the growth-inhibiting effects of ethanol. The unsaturated fatty acid (UFA) composition of S. cerevisiae is relatively simple, consisting almost exclusively of the mono-UFAs palmitoleic acid (Delta(9)Z-C(16:1)) and oleic acid (Delta(9)Z-C(18:1)), with the former predominating. Both UFAs are formed in S. cerevisiae by the oxygen- and NADH-dependent desaturation of palmitic acid (C(16:0)) and stearic acid (C(18:0)), respectively, catalyzed by a single integral membrane desaturase encoded by the OLE1 gene. We systematically altered the UFA composition of yeast cells in a uniform genetic background (i) by genetic complementation of a desaturase-deficient ole1 knockout strain with cDNA expression constructs encoding insect desaturases with distinct regioselectivities (i.e., Delta(9) and Delta(11)) and substrate chain-length preferences (i.e., C(16:0) and C(18:0)); and, (ii) by supplementation of the same strain with synthetic mono-UFAs. Both experimental approaches demonstrated that oleic acid is the most efficacious UFA in overcoming the toxic effects of ethanol in growing yeast cells. Furthermore, the only other UFA tested that conferred a nominal degree of ethanol tolerance is cis-vaccenic acid (Delta(11)Z-C(18:1)), whereas neither Delta(11)Z-C(16:1) nor palmitoleic acid (Delta(9)Z-C(16:1)) conferred any ethanol tolerance. We also showed that the most ethanol-tolerant transformant, which expresses the insect desaturase TniNPVE, produces twice as much oleic acid as palmitoleic acid in the absence of ethanol and undergoes a fourfold increase in the ratio of oleic acid to palmitoleic acid in response to exposure to 5% ethanol. These findings are consistent with the hypothesis that ethanol tolerance in yeast results from incorporation of oleic acid into lipid membranes, effecting a compensatory decrease in membrane fluidity that counteracts the fluidizing effects of ethanol.

Animals↗
PubMed1996

Characterizations of neutral lipid fatty acids and cis-9,10-epoxy octadecanoic acid in Pneumocystis carinii carinii.

Pneumocystis carinii causes pneumonitis in immunodeficient individuals and is a prevalent opportunistic infection of patients with AIDS. This pathogen resides extracellularly in the hypophase lining the alveolar epithelium, which is highly enriched in lung surfactant lipids. Procedures yielding highly pure organism preparations that enable reliable biochemical analyses of organisms isolated from the lungs of infected laboratory animals have been developed. The results of the present study revealed that the fatty acid profiles of total lipids, the neutral lipid traction, and individual neutral lipid classes of lungs from normal and immunosuppressed rats as well as P. carinii were grossly similar, although some quantitative differences were detected. One qualitative exception found was the detection in P. carinii of the rare fatty acid cis-9,10-epoxy stearic acid, which was not detected in the lipids of rat lungs. The detection of this fatty acid in P. carinii may also have important taxonomic implications. Unlike phospholipids, many of the fatty acids of nonmembrane neutral lipids may be utilized by P. carinii for other cellular functions, such as stored reserves for energy production and precursors for organism-specific membrane lipids. The present study represents the first report of detailed fatty acid analyses of individual neutral lipid classes of this important opportunistic pathogen.

Animals↗
PubMed1979

Purification and characterization of smooth and rough lipopolysaccharides from Brucella abortus.

In an attempt to obtain pure and well characterized smooth lipopolysaccharide (S-LPS) and rough lipopolysaccharide (R-LPS), smooth and rough strains of Brucella abortus were extracted by two different modifications of the phenol-water method. S-LPS was obtained in the phenol phase, and R-LPS was obtained in the aqueous phase. Further purification was accomplished by treatment with enzymes, detergents, NaI as a chaotropic agent to separate non-covalently bound contaminants, and by gel filtration. The degree of purity of the molecules was determined by chemical and immunological analysis and by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Lipid identification by gas-liquid chromatography showed seven major fatty acids. Palmitic acid accounts for about 50%, stearic acid accounts for about 10%, and hydroxylated fatty acids account for less than 5% of total fatty acids. 2-Keto-3-deoxyoctonate but not heptose was detected in the sugar analysis. Protein was found to be firmly bound to S-LPS but not to R-LPS.

Antigens, Bacterial↗
PubMed1976

Influence of litter size on lipid composition in infant mice.

The amount of milk available to each member of the litter was varied by adjusting the number of mice pups to 4, 8 or 12 per dam. The total fatty acid content of the carcass of the young increased for 2 weeks, and there was more in the well-fed groups. The fatty acid contents decreased thereafter transiently in all groups until weaning. The milk diet contributed major quantities of lauric and myristic acids to peripheral tissues but not to the liver. Undernourishment during neonatal life was associated with a relative reduction in palmitoleic, oleic and linoleic acids in lipids of the carcass. In contrast the carcass of the progeny subjected to overall dietary abundance showed relative increase in palmitoleic, oleic and linoleic acids at the expense of stearic acid.

Age Factors↗
PubMed1996

Significance of lymphocyte fatty acid changes in chronic renal failure.

In the present study we describe fatty acid fluctuations in peripheral blood lymphocytes of patients with chronic renal failure who were undergoing maintenance hemodialysis. The decreased concentrations of linoleic acid and arachidonic acid and the increase in stearic acid are discussed in relation to the lymphocyte immune response and lymphocyte membrane enzymic systems in the disease.

Adult↗
PubMed1994

Relationships between serum saturated fatty acids and serum total cholesterol and HDL-cholesterol in humans.

To investigate the effects of serum saturated fatty acids (FAs) on human cholesterol metabolism, total-cholesterol (T-C), HDL-cholesterol (HDL-C), T-C/HDL-C ratio, and FA composition [myristic acid (MA, 14:0), palmitic acid (PA, 16:0) and stearic acid (SA, 18:0)] were determined in serum from 115 men and 120 women (20-70 years old). MA, PA and SA were expressed as percentages of serum total FAs. Using multivariate analysis to account for the confounding effects of age, body mass index, drinking, and smoking it was found that SA was negatively correlated with T-C and T-C/HDL-C ratio in both men and women. In men MA was negatively correlated with HDL-C, and in women SA was positively correlated with HDL-C. Although PA was the major component of serum saturated FAs, PA had no significant relation to any cholesterol indices in either sex. These results suggest that serum MA may aggravate and serum SA may improve cholesterol metabolism, thereby influencing the risk for ischaemic heart disease.

Adult↗
PubMed1984

A competitive ligand binding assay for measurement of thyroid hormone-binding inhibitor in serum and tissues.

A competitive ligand-binding assay (CLBA) is described for measurement of an inhibitor(s) of serum binding of T4 in ether extracts of serum and in homogenates and extracts of tissues. The CLBA is based on the effect of thyroid hormone binding inhibitor (THBI) on partition of a constant amount of radiolabeled ligand [(125I]T4) between fixed amounts of serum and an anti-T4 antibody. The method is convenient, rapid, sensitive, and reproducible. The coefficient of variation averaged 8.9% within an assay and 12.8% between assays. Several fatty acids, e.g. arachidonic acid, lauric acid, linolenic acid, and linoleic acid, had potent THBI activity in the CLBA; arachidonic acid was more potent than the other fatty acids. Since oleic acid cross-reacted substantially with T4-binding sites on anti-T4, its THBI activity was examined by an equilibrium dialysis method; it was about 77% as potent as arachidonic acid. Arachidic, myristic, palmitic, and stearic acids, choleserol, various phospholipids and triglycerides (triolein and tripalmitin) had little or no THBI activity in the CLBA. THBI activity was detected in the sera of 50% (60% when serum T4 was low and 42% when it was normal) of 34 patients with nonthyroid illnesses (NTI) when studied by CLBA and in 59% (67% when serum T4 was low and 53% when it was normal) of patients when determined by the inhibitory ratio (normalized dialysis ratio/normalized binding ratio). THBI values obtained by the CLBA correlated significantly (r = 0.58; P less than 0.001) with those obtained by the inhibitory ratio method. The dose-response curve of an ether extract of pooled sera of hospitalized patients was parallel to that of arachidonic acid in the CLBA. Among various rat tissues, the small intestine had the most THBI activity in both homogenates and ether extracts of homogenates. Ether (2 vol) extracted about 63% of the THBI activity in small intestine homogenate at pH 5.2. THBI activity was demonstrable in all particulate fractions (especially mitochondria and endoplasmic reticulum) of small intestine homogenate; cytosol contained little or no THBI activity. THBI activity changed little after treatment of small intestine homogenate with trypsin or protease inhibitors.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed2002

Identification and expression of a rat fatty acid elongase involved in the biosynthesis of C18 fatty acids.

A major part of the palmitic acid (C16:0) generated by fatty acid synthase is converted into stearic acid (C18:0) via carbon chain elongation. Here, we describe the cloning and expression of a rat hepatic enzyme, rELO2, responsible for the elongation of C16:0, presumably at the condensing reaction. Heterologous expression experiments in a yeast, Saccharomyces cerevisiae, demonstrated the elongation activity of rELO2 on C16:0 and to a lesser extent, C18:0 and fatty acids with low desaturation degree. This was distinct from that rELO1, a rat homolog of HELO1, which preferably catalyzed the elongation of mono- and polyunsaturated fatty acids of C16-C20. The Northern analysis showed that the expression of rELO2, but not rELO1, in hepatocytes was activated by the cycles of fasting and refeeding rats on a fat-free diet. Under these conditions, the rELO1 was expressed constitutively in various tissues but the rELO2 transcripts were detected predominantly in liver.

Acetyltransferases↗
PubMed1985

Isolation and characterization of gangliosides from pig lymphocytes.

Two major gangliosides from pig spleen lymphocytes, accounting for 57% of the total lipid-bound sialic acids, were isolated and purified to homogeneity by column chromatography on DEAE-Sephadex and silica gel. They were identified as GM3 (II3Neu5GcLacCer), and GD3 (II3(Neu5Gc)2LacCer), by thin-layer chromatography in comparison with standards and by analysis of the constituent sugars. The major fatty acids of these gangliosides were stearic acid and myristic acid, respectively. In addition to these gangliosides, GD2 and bands comigrating on thin-layer chromatography with authentic GM2, GM1, GD1a and GD1b were found. These compounds also occur in pig peripheral blood lymphocytes, where, however, GD3 represents about 70% of the total lipid-bound sialic acid.

Animals↗
PubMedDate not supplied

Differences in membrane order between C3H 10 T1/2 cells and their transformed counterparts as measured by EPR.

Membrane order of mouse embryo fibroblasts and their ionizing radiation and chemically transformed counterparts was investigated using EPR spectroscopy after labeling the membrane of the cells with the fatty acid spin label, 5-nitroxy stearic acid. The EPR spectra were recorded at temperatures ranging from 18 to 38 degrees C for both control and transformed cells. The distance between the outer hyperfine splitting (2T' parallel), which is used as indicator of membrane order, varies in these two cell types. Below 28 degrees C. 2T' parallel is higher in transformed fibroblasts than in normal cells, whereas above this temperature membrane order is the same. Lipid analysis as carried out by the measurement of the cholesterol/membrane proteins and sphingomyelin/lecithin ratios, showed no difference in the amounts of the main membrane rigidifiers. These findings suggest that cell transformation of mouse fibroblasts induced by radiation or chemicals may produce alterations in the cell membrane, as evidenced by variations in its order at low temperature. These measured differences are presumably not attributable to its fatty acids composition but to its glycoproteins content, since changes in membrane rigidifiers were not observed between normal and transformed cells.

Animals↗
PubMed1978

Effect of dietary oil, cholesterol, and soysterols on the lipid concentration and fatty acid composition of egg yolk, liver and serum of laying hens.

Effect of dietary lipid factors (saturated and unsaturated oil, zoo and phytosterols) on the lipid concentration and fatty acid composition of egg yolk, liver and serum of the laying hen were studied. Single Comb White Leghorn laying hens, at 30 weeks of age, were fed two basal diets containing 8.0% hydrogenated coconut oil (HCO) or safflower oil (SFO), with or without supplemental cholesterol (1.0%), soysterols (2.0%) or combination of both. When HCO basal diet was fed, both liver weight and lipid content were significantly (P less than .01) increased as compared to hens fed the SFO diet. Cholesterol feeding increased total lipid content in liver and serum, whereas soysterol feeding reduce or diminish lipid accumulation caused by the cholesterol treatment. Both dietary cholesterol and soysterols alter the fatty acid composition of liver, serum and egg yolk lipids by increasing oleic acid and decreasing palmitic and/or stearic acids. These changes were significantly greater upon feeding cholesterol than soysterols. However, the simultaneous feeding of cholesterol with soysterols exerted the least effect on the fatty acid composition.

Animals↗
PubMedDate not supplied

Variations in fat and fatty acid intakes of adult males from three regions of India.

Fat and fatty acid intakes of 25 healthy adult urban males from Ghaziabad, U.P.; Goa and Kolkata, W.Bengal, respectively were studied. Fat intakes were estimated using dietary records, food frequency questionnaires and chemical analysis of the diets consumed. Fatty acid intakes were estimated by gas chromatography. Total fat intakes ranged from 26.9 g/day to 163.2g/ day. Percent subjects having intakes above the desirable level were 72% in Kolkata, 36% in Ghaziabad, U.P. and only 10% in Goa. Visible fat constituted more than 60 percent of total fat. In all 3 areas, SFA intakes were higher and MUFA lower than desirable levels. Palmitic acid constituted at least 50% of SFA intakes. In Goa, lauric acid, in Ghaziabad and Kolkata, stearic acid and myristic acid were major dietary SFAs, In Kolkata, erucic acid was 17.3+/-8.3%. Overall 60% of subjects had n-6:n-3 intakes close to the desirable ratio. Linoleic acid constituted almost the entire n-6 intake. Alpha linolenic acid constituted most of the n-3 intakes in Ghaziabad, U.P. and Kolkata. The ratios of SFA:MUFA--PUFA vaned widely and percent subjects with intakes close to the desirable ratios were 12% in Goa, 23% in Ghaziabad and 40% in Kolkata. The data highlights the need for limiting fat intakes and modifying diets to provide fatty acids in desirable ratios.

Adult↗
PubMed1985

[Fatty acid composition of Fusidium coccineum lipids].

The fatty acid composition of the lipids synthesized de novo or during growth of the organism producing fusidic acid, Fusidium coccineum on complex media was studied. The content of the total extractable lipids in the mycelium did not exceed 10-11 per cent ty the biomass dry weight. Unsaturated fatty acids with 18 carbon atoms in the chain, mainly oleinic and linoleic acids and saturated fatty acids such as palmitic and stearic acids predominated. The ratio of the main fatty acids and the content of the minor acids were subject to strains and conditions of their cultivation. However, linoleic and oleinic acids predominated in all the lipids except the lipids from submerged cultures growing in the form of unusually large clots. Such lipids contained up to 60 per cent of palmitic acid.

Chromatography, Gas↗
PubMed1978

Studies in Tetrahymena membranes substrates for desaturation of fatty acyl chains in Tetrahymena pyriformis microsomes.

[1-14-C]Palmitoyl-Co A was incubated with Tetrahymena microsomes containing the complete enzyme system for desaturation during various time periods. The level of [1-14C]palmitoleoyl-CoA increased to a maximum during the 1--3 min incubation time, while [1-14C]palmitoleic acid in the phospholipid reached a maximum level during 6--7 min incubation time. The radioactivity of [1-14C]palmitoleic acid in free fatty acid and the triglyceride fraction was not significantly observed upon 3 min incubation. Incubation of [1-14C]palmitoyl-CoA with microsomes in the absence of NADH produced [1-14C]palmitoyl lipid without desaturation. Radioactive palmitic acids in the microsomal lipids were not converted to palmitoleic acids after addition of NADH by the complete enzyme system. When microsomes prepared from cells labeled with [1-14C]palmitic acid or [1-14C]stearic acid were incubated alone in the presence of O2 and NADH, no significant increase in [1-14C]palmitoleic acid in the phospholipid was observed, wherease an increase in [1-14C]linoleic acid and gamma-[1-14C]linolenic acid did occur at the expense of [1-14C]oleic acid in the phospholipid. From these results it can be concluded that the enzyme involving desaturation of palmitic acid to palmitoleic acid requires palmitoyl-CoA as the substrate. However, the possibility of oleoyl and linoleoyl phospholipids being substrates in the desaturation of Tetrahymena microsomes was suggested.

Acyl Coenzyme A↗
PubMed1982

Asymmetric metabolism of phosphatidylethanolamine in the human red cell membrane.

The incorporation of labeled fatty acids into phosphatidylethanolamine (PE) on the two sides of the human red cell membrane was studied by use of the vectorial probe trinitrobenzene sulfonate (TNBS). A small population of PE molecules on the outer surface of the membrane has a 4-fold higher turnover rate than the remaining PE molecules. This effect is greatest with palmitic acid, less with linoleic and linolenic acids, and not seen with stearic acid. By use of the hydrophobic penetrating probe fluorodinitrobenzene (FDNB), we find a second larger population of PE and phosphatidylserine (PS) molecules which reacts with FDNB and has a higher specific activity than the PE and PS molecules which do not react. With human polymorphonuclear cells, the labeled PE molecules inside the cell have a higher specific activity than the PE molecules located on the outer cell surface. These results suggest that there are heterogeneous populations of PE and PS on both halves of the red cell membrane which show different metabolic turnover rates of their fatty acids.

Carbon Radioisotopes↗
PubMed1980

[Comparative digestive utilization and forms of fecal excretion in the rat of erucic and brassidic acids esterified in different glyceride structures].

The digestibility and fecal excretion patterns of erucic (cis n-9 docosenoic) and brassidic (trans n-9 docosenoic) acids, esterified in triglycerides of different structure, were compared in the rat. Synthetic triglycerides were prepared either by mixing or interesterifying trierucin or tribrassidin with an equal amount of corn oil. Rapeseed and peanut oils were used as references. The apparent digestibility of trierucin mixed or interesterified with corn oil was similar to that of peanut oil but higher than that of rapeseed oil. The high amount of 2-monoerucin resulting from diets containing trierucin explained the improved digestibility of erucic acid as compared to that of rapeseed oil which had a very small erucic acid content on the 2-position. It also seemed that 2-monoerucin enhanced the digestibility of saturated fatty acids. Tribrassidin mixed with corn oil had a poor digestibility because pancreatic lipase hydrolysis was delayed in the intestinal lumen. The high melting point of the homogeneous triglyceride was responsible for that phenomenon. The interesterification of tribrassidin with corn oil, which drastically lowered the melting point of the mixture from 52 to 37 degrees C, improved both the hydrolysis of the triglycerides and the digestibility of the C22: 1 trans fatty acid as well as that of the other fatty acids in the diets. Nevertheless, the unabsorbed brassidic acid in every case was principally excreted in the form of a compound insoluble in organic neutral solvent. In that respect, brassidic acid behaved like shorter chain saturated fatty acids such as palmitic and stearic acids.

Animals↗
PubMedDate not supplied

[Fatty acids contained in 4 pejibaye palm species, Bactris gasipaes (Palmae)].

Cooked and uncooked samples from four pejibaye palm races were analyzed to determine the moisture content, ether extract and the content of six fatty acids (C16:0 to C18:3). There was an increase in moisture and a decrease in ether extract (p < 0.05) in the cooked samples in comparison with the uncooked ones. No significant differences were found in fatty acid content between cooked and uncooked samples, but there were differences (p < 0.05) among races concerning the content of four fatty acids. Pejibaye fat is mainly mono-unsaturated (45.6%) and has a low poly-unsaturated to saturated fatty acid ratio (0.5). The fatty acid profile of uncooked pejibaye samples was: oleic acid, 32.6 to 47.8%; palmitic acid, 30.5 to 40.3%; linoleic acid, 11.2 to 21.1%; palmitoleic acid, 5.7 to 7.1%; linoleic acid, 1.5 to 5.5%; and stearic acid, 1.7 to 2.4%.

Fatty Acids↗