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At least 1,531 records · Page 85Linked to original sources
PubMed1995

Erythrocyte lipids in triose-phosphate isomerase deficiency.

Marked hypoalphalipoproteinemia was found together with relatively low serum cholesterol, triacylglycerol, and LDL levels in a triose-phosphate isomerase (TPI; D-glyceraldehyde-3-phosphate ketol-isomerase, EC 5.3.1.1)-deficient Hungarian family, especially in the two compound-heterozygote brothers. Apart from a slight increase in palmitic and stearic acids together with a slight decrease in oleic and linoleic acids, no other changes were found in the fatty acid composition of the erythrocyte phospholipids. Anisotropy measurements with n-(9-anthroyloxy) stearic and -palmitic acid fluorophores revealed increased motional freedom of the fatty acid chains in the external lipid layers of the intact erythrocytes from all members of the TPI-deficient family as compared with normal age-matched controls. This asymmetric increase in membrane fluidity was found to be significantly higher in the propositus than in his compound-heterozygote brother without any neurological disorders. The change in membrane fluidity may result from as-yet-unresolved aspects of the lipid composition of the plasma membrane. Our findings that the differences between the TPI-deficient individuals and normal controls and the differences between the two compound-heterozygote brothers were all absent in the phospholipid extracts of the same erythrocytes favor the assumption that the increased motional freedom of the fatty acid chains in the external surface of the bilayer is caused by the binding of the mutant TPI molecule to the N-terminal sequence of band 3 protein.

Adult↗
PubMed1996

Regulation of stearoyl-CoA desaturase 1 mRNA stability by polyunsaturated fatty acids in 3T3-L1 adipocytes.

The effects of arachidonic acid (20:4, n-6) and other fatty acids on the expression of stearoyl-CoA desaturase gene 1 were investigated in fully differentiated 3T3-L1 adipocytes. Treatment of 3T3-L1 adipocytes with arachidonic acid resulted in a decrease in stearoyl-CoA desaturase (Scd) enzyme activity and scd1 mRNA. Arachidonic acid did not alter the transcription of the scd1 gene, whereas the half-life of the scd1 mRNA was reduced from 25.1 to 8.5 h. Blocking the conversion of arachidonic acid to eicosanoids by pretreatment of the cells with cyclooxygenase, lipoxygenase, or cytochrome P-450 epoxygenase inhibitors did not reverse the inhibition caused by arachidonic acid, indicating that eicosanoid synthesis is not necessary for the repression of scd1 mRNA expression. Treatment of adipocytes with linoleic (18:2, n-6) and linolenic (18:3, n-3) acids also resulted in inhibition of scd1 mRNA accumulation. By contrast, oleic acid (18:1, n-9) and stearic acid (18:0) had no effect on scd1 mRNA levels. Taken together, these results suggest that polyunsaturated fatty acids repress the expression of the scd1 gene in mature adipocytes by reducing the stability of scd1 mRNA.

3T3 Cells↗
PubMed1999

Fatty acid composition and arachidonic acid intake of selected Saudi foods.

Twenty-eight Saudi Arabian common foods were analyzed for their fatty acid contents by gas-liquid chromatography using capillary column. The predominant fatty acids were oleic, palmitic, linoleic and stearic acids. The polyunsaturated to saturated fats ratio (P:S) as well as the n-3:n-6 ratio were generally not compatible with recommended values. Assessment of C20:4 (n-6) content in those foods showed a noticeable variation ranging from 9 mg/100 gm in beef sirloin to 256 mg/100 g in kannad fish. Eicosapentaenoic acid (C20:5) n-3 content was highest in kannad (925 mg/100 g). Applying C20:4 (n-6) values determined in this work to Saudi Balanced Sheet, the mean C20:4 (n-6) intake for a Saudian was estimated as approximately 115 mg/day.

Arachidonic Acids↗
PubMed1981

The application of droplet counter-current chromatography (DCC) for the separation of acidic glycolipids.

Droplet counter-current chromatography (DCC) a novel liquid-liquid partition technique, is a useful method for the separation of glycolipids. After a series of investigations on suitable experimental conditions for DDC, mouse brain chloroform-methanol-0.5% CaCl2-n-propanol (50:60:40:6) by the ascending method with 500 standard columns. GM1 and cerebroside sulfuric ester (CSE) from whale brain glycolipid fraction were separated by DCC into two peaks and three peaks, respectively, with chloroform-methanol-water-n-propanol (50:60:40:2) and 500 standard columns. The occurrence of two peaks of GM1 was due to the differences of sphingenine and fatty acid compositions. In the former peak of GM1, the majority of long chain base and fatty acid were 18:1 sphingenine and stearic acid, respectively, while the latter contained 18:1 (32%), 20:1 (68%) sphingenine and 16:0 (14.5%), 18:0 (61.4%), and 20:0 (21.0%) fatty acids. The three peaks of CSE were due to the difference of carbon chain length and to the presence or absence of a hydroxyl group in fatty acids. The first polar fraction (CSE-I) had hydroxy 23:0 (34%) and 24.1 (53.4%) fatty acids and the second fraction (CSE-II) contained hydroxy 24:0 (70.5%) and 25:1 (12.8%) fatty acids, while the third fraction (CSE-III) had normal 23:0 (11.9%), 24:1 (56.4%), hydroxy 25:0 (11.4%) and 26:1 (9.7%) fatty acids. Preparative DCC was also applied to the glycolipid fraction from Tay-Sachs' brain to give 242 mg of practically pure GM2 from 700 mg of crude brain extract without any preliminary purification.

Animals↗
PubMed2001

The use of near-infrared reflectance spectroscopy in the prediction of the chemical composition of goose fatty liver.

The use of near-infrared reflectance spectroscopy (NIRS) on a meat product is described in this report. The aim of the study was to develop calibration equations to predict the chemical composition of goose fatty liver (foie gras) with lipid contents greater than 40% of the fresh pate. Spectra of 52 foie gras samples were collected in the visible and NIR region (400 to 2,498 nm). Calibration equations were computed for DM, CP, lipids and fatty acids using modified partial least-squares regression. R2 values were high for the total lipid content (0.805) and DM (0.908) but were low for ash (0.151) and relatively low for protein content (0.255). For the major fatty acids, R2 ranged from 0.886 for palmitic acid to 0.988 for oleic acid. Oleic acid, the main fatty acid of the liver, and the stearic acid had higher R2 values than the less represented fatty acids. This study suggests that the NIRS technique can be used to predict lipid content and the fatty acid composition of goose fatty livers, but calibration must be built on a larger number of samples to generate accurate predictions.

Animals↗
PubMed1990

Glutathione-protein mixed disulfide decreases the affinity of rat liver fatty acid-binding protein for unsaturated fatty acid.

.16 +/- 0.062% of the fatty acid-binding protein purified from 50 mM N-ethylmaleimide-treated rat liver (L-FABP) was determined as a form S-thiolated by glutathione (L-FABP-SSG). L-FABP-SSG, which was prepared in vitro through thiol-disulfide exchange reaction, showed more acidic pI (approximately 5.0) than the pI (approximately 7.0) of reduced L-FABP. S-thiolation of L-FABP by glutathione decreased the affinity of the protein for unsaturated fatty acids without changing the equimolar maximum binding. The changes in Kd were from 0.63 +/- 0.054 microM to 1.03 +/- 0.14 microM for oleic acid, from 0.63 +/- 0.028 microM to 0.97 +/- 0.12 microM for linoleic acid and from 0.85 +/- 0.050 microM to 1.45 +/- 0.024 microM for arachidonic acid. This modification did not alter the affinity nor the maximum binding for saturated fatty acids, which were determined to be Kd of approximately 1.0 microM for palmitic acid and approximately 0.9 microM for stearic acids, and equimolar maximum binding for both fatty acids. The binding affinity of L-FABP for unsaturated fatty acid may be regulated by redox state of the liver.

Amino Acids↗
PubMed1982

The influence of bicuculline-induced seizures on free fatty acid concentrations in cerebral cortex, hippocampus, and cerebellum.

Using ventilated rats maintained on N2O-O2 (70:30, vol/vol) we induced continuous seizures with i.v. bicuculline and analysed free fatty acids (FFA) in cerebral cortex, hippocampus, and cerebellum after seizures durations of 1-120 min. In the cerebral cortex, peak FFA concentrations were observed after 5 min, with a threefold increase in total FFA content. The values then remained unchanged for the next 15-20 min, but decreased thereafter. At 60 and 120 min, total FFA contents were only moderately increased above control. In the initial period, arachidonic acid increased about 10-fold and stearic acid 2- to 3-fold, with little change in palmitic acid and linoleic acid concentrations. At all times, the docosahexenoic acid concentration was markedly increased. Following its massive accumulation at 1 min, arachidonic acid gradually decreased in concentration. Pretreatment of animals with indomethacin did not alter this behaviour. After 20 and 120 min of seizure activity, changes in total and individual FFA concentrations in the hippocampus were similar to those observed in the cerebral cortex. The cerebellum behaved differently. Thus, at 20 min the only significant change was a 5- to 10-fold increase in arachidonic acid concentration and, after 120 min, total and individual FFA concentrations were similar to control values. Furthermore, since the control values for arachidonic acid were much lower in the cerebellum, the 20-min values were only about 20% of those observed in the cerebral cortex and the hippocampus.

Animals↗
PubMed1987

Large alterations in ganglioside and neutral glycosphingolipid patterns in brains from cases with infantile neuronal ceroid lipofuscinosis/polyunsaturated fatty acid lipidosis.

Lipid composition was studied on cerebral tissue from nine children who had died of a progressive encephalopathy called the infantile form of neuronal ceroid lipofuscinosis (INCL) or polyunsaturated fatty acid lipidosis (PFAL). In the terminal stage of the disease, the concentrations of all lipid classes were found to be significantly reduced in the cerebral and cerebellar cortex and white matter. The concentration of gangliosides of the cerebral cortex was 15% and that of cerebrosides (galactosylceramide) in white matter 0.2-5% of the normal values for the children's ages. The reduction of gangliosides mainly affected those of the gangliotetraose series, particularly GD1a. The fatty acids of the linolenic acid series were strongly reduced in ethanolamine and serine phosphoglycerides. A very large increase up to 100-fold of oligoglycosphingolipids of the globo series and two fucose-containing lipids of the neolacto series was found in the forebrain of the three advanced cases examined. The brain tissue also contained very high concentrations of mono-, di-, and trisialogangliosides of the lacto and neolacto series, gangliosides with type 1 chain dominating. The structures of the gangliosides were tentatively identified by gas chromatography-mass spectrometry and monoclonal antibodies with carefully determined epitope specificity. The gangliosides and neutral glycosphingolipids had very similar fatty acid composition, consisting of about 40% stearic acid and 40% C24-acids.

Brain↗
PubMed1978

Preparations used for the artificial feeding of infants.

Cow's milk differs from human milk in a number of important ways, and manufactures of dried milk preparations for infants have used various methods to make the composition of the diluted product more like that of human milk. The first was to add lactose, or to recommend the mother to add sucrose. This not only increased the carbohydrate, but also 'diluted' the protein and inorganic constituents which are more concentrated in cow's than in human milk. The second was to replace all or part of the cow's milk fat with animal and vegetable fats, and so make the fatty acid composition more like that of human milk fat. In particular the proportion of linoleic acid was increased and that of stearic acid decreased, and this made the fat more easily digested and absorbed by the young infant. The third modification of cow's milk has been more fundamental. Its aim has been to make a product containing less sodium and phosphorus than cow's milk and with a higher lactalbumin: casein ratio. Whey, which contains lactalbumin but not casein, is used as the starting material. This is dialysed to remove soluble inorganic constituents. Some skimmed milk is then added to supply casein and some minerals, and the composition is adjusted as required with further minerals and vitamins. Lactose is added and a mixture of animal and vegetable fats. Dried milks on sale in Britain contain added vitamins A,D, and C and also iron. Some have added copper and zinc.

Animals↗
PubMed1976

[Leukocyte lipids in mature cell leukemia].

The total lipid content and the lipid pattern of normal and leukemic leukocytes showed no significant difference except the fact, that lymphocytes of chronic lymphatic leukemia have a lower content of triglycerides and sphingomyeline. Lecithin of leukemic lymphocytes contained more palmitinic acid and oleic acid and a lower level of stearic acid than the same fraction in normal lymphocytes. The lipid pattern of normal and leukemic granulocytes was identical.

Cholesterol↗
PubMed1983

A comparative study of the distribution and fatty acid composition of the lipoproteins in the fetal and maternal plasma of sheep.

Fetal plasma contained significantly lower amounts of lipoproteins than the mother. In both mother and fetus, high density lipoprotein (HDL) was the major fraction. Very low density lipoprotein (VLDL) accounted for 12% of total plasma lipid in the mother but only 4% in the fetus. Maternal and fetal plasmas showed similar distributions of lipids in their HDL and low density lipoprotein (LDL) with cholesteryl esters comprising the major lipid of both and LDL having a higher level of triglycerides and lower level of phospholipids than HDL. Low levels of triglycerides were present in fetal VLDL. There were pronounced increases in levels of unsaturated fatty acids with increasing lipoprotein density. In the mother, levels of linoleic acid increased and in the fetus palmitoleic and oleic acids increased. The major saturated fatty acids in the fetal lipoproteins was palmitic acid and in the maternal lipoproteins stearic acid. In contrast to the mother, LDL and HDL of the fetus showed similar fatty acid compositions.

Animals↗
PubMed1981

The effect of oxygen exposure on erythrocyte phospholipid composition.

Phospholipids in plasma and erythrocytes of rats exposed to 100% oxygen for 3 days were analyzed. Exposed rats contained lower quantities of several phospholipids in both plasma and erythrocytes than in matched controls. Pronounced decreases were found in phosphatidylcholine and lysophosphatidyl choline. The proportion of disaturated species in erythrocyte phosphatidylcholine was significantly greater after oxygen exposure. There was an increase in percentage of saturated fatty acids with a proportionate decrease in percentage of unsaturated fatty acids. The increase in saturation was associated primarily with palmitate while decreased unsaturation involved primarily linoleic acid. In plasma the proportions of stearic acid increased while those of linoleic, arachidonic and docosahexaenoic acids decreased in phosphatidylcholine. Damage to cell lipids may account for increased hemolysis which occurs after exposure to high oxygen concentrations. Erythrocytes recovered following oxygen exposure contained phospholipid species commonly found in immature red blood cells.

Animals↗
PubMedDate not supplied

5-Fluorouracil-loaded chitosan microspheres: preparation and release characteristics.

Cross-linked chitosan microspheres containing 5-Fluorouracil (5-FU) were prepared. Variables believed to be important for microsphere properties were examined; these included: drug and chitosan concentrations, cross-linking process, the type of oil, stirring rate and also additives. Initial 5-FU concentration, the type and concentration of chitosan, the viscosity of oil phase and glutaraldehyde concentration affected drug release from chitosan microspheres. 5-FU release from cross-linked chitosan microspheres is characterized by an initial rapid release of drug. Addition of substances such as alginic acid, chitin, agar, sodium caprylate and stearic acid changed the release properties of 5-FU microspheres.

Chitin↗
PubMed2006

Growth-inhibiting activity of active component isolated from Terminalia chebula fruits against intestinal bacteria.

The growth-inhibitory activity of materials derived from the fruit of Terminalia chebula was evaluated against six intestinal bacteria by means of an impregnated paper disk agar diffusion method. The butanol fraction of T. chebula extract had profound growth-inhibitory activity at a concentration of 5 mg per disk. The biologically active component isolated from the T. chebula fruits was identified with a variety of spectroscopic analyses as ethanedioic acid. The growth responses varied in accordance with the bacterial strain, chemical, and dosage tested. In a test with concentrations of 2 and 1 mg per disk, ethanedioic acid had strong and moderate inhibitory activity against Clostridium perfringens and Escherichia coli, respectively, with no associated adverse effects on the growth of the four tested lactic acid-producing bacteria. Ellagic acid derived from T. chebula fruits exerted a potent inhibitory effect against C. perfringens and E. coli, but little or no inhibition was observed with treatments of behenic acid, P-caryophyllene, eugenol, isoquercitrin, oleic acid, ca-phellandrene, 3-sitosterol, stearic acid, a-terpinene, terpinen-4-ol, terpinolene, or triacontanoic acid. These results may be an indication of at least one of the pharmacological properties of T. chebula fruits.

Clostridium perfringens↗
PubMed1998

Lipid composition and vitamin E content in human colostrum and mature milk.

Lipidic components, as well as fatty acid composition and vitamin E content were determined in colostrum (days 3-5 of postpartum) and mature milk (day 21) in 8 women from Murcia (Spain). Triglycerides concentration was higher and cholesterol and esterified cholesterol were lower in mature milk than in colostrum, whereas phospholipid content was similar. These differences indicate that the diameter of milk fat globules increases in mature milk. The percentage of medium-chain fatty acids (12:0 and 14:0) increased in mature milk as compared to colostrum, reflecting de novo synthesis of fatty acids. With the only exception of stearic acid which was lower in mature milk than in colostrum, the remaining long-chain fatty acids was similar. The proportion of both linoleic (18:2) and eicosapentaenoic (20:5) acids found in mature milk and colostrum is higher than in studies from other countries and may reflect the intake of high proportions of polyunsaturated fat from vegetable oils and fish in the studied women. Both vitamin E content and vitamin E/linoleic acid ratio in mature milk are lower than in colostrum, evidencing the efficient mechanism of mammary gland vitamin E uptake around parturition.

Adult↗
PubMed1999

[The compositional analysis of phospholipids and their fatty acids in rabbit sarcoplasmic reticulum].

Phospholipids were extracted from the sarcoplasmic reticulum of rabbit skeletal muscle, and separated by high performance thin layer chromatography. The mole fraction of individual phospholipids were determined by assaying phosphorus of each band. Main phospholipids were scraped and extracted, and subjected to esterification by alkaline methanol, and then the composition and content of fatty acids were determined by gas chromatography. The results show that the main phospholipid components were PC (phosphatidylcholine) and PE (phosphatidylethanolamine). They account for 66.5% and 15.5%, respectively. The main fatty acid in PC is palmitic acid and those in PE are stearic acid and arachidic acid.

Animals↗
PubMedDate not supplied

Leaching of organic acids from irradiated EVA plastic as a function of solution pH and polarity.

The leaching of several target organic acids from an irradiated ethylene vinyl acetate material, such as those used as a solution product container, is examined as a function of solution pH and polarity. The targeted compounds included highly soluble weak acids such as acetic and formic acids, and larger, more lipophillic acids such as myristic, palmitic, and stearic acids. The leaching of these compounds was examined over a pH range of 3 to 11 and in various ethanol/water proportions. While pH and solution polarity had only a modest impact on the accumulation of the acetic and formic acids, the accumulation of the fatty acids was greatly affected by both factors. It is suggested that the accumulation of these leachables at high pH is influenced by two processes. The first process, partitioning, the speciation of the acidic leachables (protonated versus dissociated form) contributes to the pH trends observed. In this case, entities that already exist in the plastic partition themselves between the plastic and solution via migration. A second, more important, contributor to the leaching of these acids is a pH-dependent increase in their availability arising from an unspecified reactive process.

Acids↗