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At least 919 records · Page 51Linked to original sources
PubMed1979

Fatty acids in female Macracanthorhynchus hirudinaceus (Acanthocephala).

Neutral lipids and phospholipids in the body wall, lemnisci and pseudocoel and neutral lipids of fluid found in the "tube" system of the lemnisci and the lacunar system of the body wall of Macracanthorhynchus hirudinaceus (Acanthocephala) were determined by the technique of thin layer chromatography and gas chromatography (GC). Sixteen different fatty acids from nonpolar lipids were identified as follows: 8:0, 10:0, 11:0, 12:0, 13:0, 14:0, 14:1, 16:0, 18:0, 18:1, 18:2 and/or 20:0, 18:3 and/or 20:1, 20:3, 22:1, 24:1 and 22:6. In addition, there were three unidentified GC peaks corresponding to chain lengths greater than 20 carbons. Sixteen different fatty acids from phospholipids were identified in each of the three fractions analyzed. They were as follows: 10:0, 11:0, 12:0, 13:0, 14:0, 14:1, 16:0, 16:1, 18:0, 18:1, 18:2 and/or 20:0, 20:2, 20:3, 22:1, 24:1 and 22:6. Four unidentified peaks were also observed. There was a significant difference in the percentage of lipid as well as the concentration of particular fatty acids when each fraction was compared. There was also an abundant supply of sterols and glycerides in each fraction.

Acanthocephala↗
PubMed1987

Hepatic lipid abnormalities in a chemical/viral mouse model for Reye's syndrome.

We have examined hepatic lipid profiles in a mouse model for Reye's Syndrome (RS) in which young animals are exposed to nontoxic doses of an industrial pesticide emulsifier and subsequently are infected with sublethal doses of mouse-adapted human Influenza B (Lee) virus (FluB). The purpose of this study was to determine whether liver lipid content was altered in the mice, the time course of any changes, and whether lipid changes were consistent with liver pathology. Neonatal mice exposed dermally to the emulsifier, Toximul MP8 (Tox), had significantly elevated levels of hepatic cholesterol, with otherwise normal lipid composition. Subsequent inoculation of the mice with FluB significantly increased mortality rate. The combined Tox + FluB treatment had several significant effects on liver lipids, including a transient increase in phospholipid (PL) content, a reduction in neutral glycerides and persistently high cholesterol levels. Abnormalities in fatty acid profiles included an apparent elevation in medium chain fatty acids and increased ratios of PL arachidonic to docosahexaenoic acids. Histologically, there was no evidence of fat accumulation in the liver; however, hepatic mitochondria had severe structural abnormalities characteristic of RS. These studies demonstrate that chemical-dependent enhancement of viral virulence is associated with significant alterations of hepatic lipids. We believe that these abnormalities are related to mitochondrial structural damage in RS despite the absence of hepatic steatosis.

Animals↗
PubMed1985

Temperature-induced phase change in a fat. A study by electron spin resonance.

Electron Spin Resonance, Differential Scanning Calorimetry and rheological techniques have been used to study the physical changes induced by temperature in lard and in the solid and liquid fractions obtained by fractionation of lard at 15 C. The mobilization process of a C18 fatty acid nitroxide derivative dispersed in the molten fat has been observed in the temperature range -50 to +70C. The mobilization of the probe seemed to be concomitant with the melting of the low melting point glycerides. Above this temperature, all the probes were in the liquid phase and their mobility reflected the viscosity of their liquid environment, or the viscosity of the bulk fat when crystal was no longer present. Probe mobility was temperature dependent, and it was identical for the three fats at the same temperature, despite their different triglyceride compositions.

Adipose Tissue↗
PubMed1983

Lung lipid synthesis from acetoacetate and glucose in developing rats in vitro.

Acetoacetate (AcAc) and glucose were compared as energy sources and as precursors for lipid synthesis in the lungs of developing rats. Minced lung tissue was incubated with [3-14C]AcAc or [U-14C]glucose and the oxidation of each substrate to CO2 or its incorporation into tissue lipids was quantified. The highest rates of oxidation were obtained during the first 5 days for AcAc and the first 2 days of life for glucose and oxidation of AcAc was 3-4 times greater than that of glucose at all ages. Throughout postnatal development, the rates of nonsaponifiable lipid, fatty acid and hence total lipid (chloroform/methanol extractable) synthesis from AcAc were 2-3 times those of glucose. The highest rates of total lipid synthesis from AcAc and glucose were observed at birth. Glucose was utilized for glyceride-glycerol synthesis at a higher rate than AcAc. Similar patterns of incorporation of AcAc and glucose into various lipid classes were noted. Of the total lipids synthesized from AcAc and glucose, respectively, phospholipid plus monoglyceride accounted for 64% and 77%, triglyceride 13% and 13%, diglyceride plus cholesterol 11% and 4%, fatty acids 9% and 4%, and cholesteryl esters 3% and 1%. AT birth, the specific activities of all lipids except triglyceride derived from AcAc were greater than those from glucose. Rates of synthesis of all complex lipids declined with age. The results of these experiments demonstrate that AcAc is utilized more readily than glucose for energy production and lipid synthesis in developing rat lungs.

Acetoacetates↗
PubMed1985

Pulmonary surfactant lipid synthesis from ketone bodies, lactate and glucose in newborn rats.

The contribution of acetoacetate (AcAc), beta-hydroxybutyrate (beta OHB), lactate and glucose to pulmonary surfactant lipid synthesis in three- to five-day-old rats was measured. Minced lung tissue was incubated with 3H2O and [3-14C]AcAc, [3-14C]beta OHB, [U-14C]lactate or [U-14C]glucose, and the radioactivity incorporated into surfactant lipids was measured. When expressed as nmol of substrate incorporated/g lung tissue per four hr, lactate was incorporated more rapidly than other substrates into total surfactant lipids and phosphatidylcholine (PC). There was no difference in the rates of incorporation of lactate, AcAc or glucose into disaturated PC (DSPC). Substrates other than glucose were incorporated almost exclusively into fatty acids, whereas 60-80% of glucose incorporated into surfactant phospholipids was found in fatty acids, with the remaining in glyceride-glycerol. When expressed as nmol acetyl units incorporated/g lung tissue per four hr, the rates of AcAc, lactate and glucose incorporation into total surfactant fatty acids were comparable. Glucose incorporation into DSPC and PC was greater than that of AcAc and lactate. When glucose was the only exogenous substrate added to the incubation medium, it contributed 37% of total surfactant fatty acids synthesized de novo. In the presence of other substrates, the contribution of glucose to de novo fatty acid synthesis dropped to 14-20%. In the presence of unlabeled glucose, 14C-labeled AcAc, lactate and beta OHB contributed 52%, 40% and 19%, respectively, of the total fatty acids synthesized de novo. The rate of beta OHB incorporation into surfactant lipids was only about 50% that of other substrates and was accompanied by low activity of beta-hydroxybutyrate dehydrogenase measured for newborn lung.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxybutyric Acid↗
PubMed1984

Effect of ingestion of thermally oxidized frying oil on peroxidative criteria in rats.

Thermally oxidized rapeseed oils (4 levels of deterioration; used by a manufacturer of fried fish paste in a conventional manner) were fed to rats at a practical level of concentration. Rats were fed a diet ad libitum for 13 weeks that contained 15% of a test oil. The effects of the diet on several biochemical criteria related to peroxidative alterations were investigated. In groups given thermally oxidized oils relative liver weight, relative kidney weight, thiobarbituric acid-reactive substances (TBA-RS) in the liver and reduced glutathione content were increased significantly in proportion to the degree of deterioration of the oil, compared with the group given fresh oil. Tocopherol contents in both serum and liver were decreased considerably in proportion to the deterioration level of the supplied oils. The above criteria correlated well with various deterioration indices of the oil. For instance, TBA-RS was well correlated (p less than 0.001) with petroleum ether-insoluble oxidized fatty acid (r = 0.9191), column chromatographically separated polar fraction (r = 0.9056), glyceride dimer fraction (r = 0.9023) and carbonyl value (r = 0.8647).

Animals↗
PubMed1986

Serum lipid abnormalities in a chemical/viral mouse model for Reye's syndrome.

Neonatal mice given nontoxic dermal applications of an industrial surfactant, Toximul MP8 (Tox), and subsequently infected with sublethal doses of mouse-adapted human Influenza B (Lee) virus (FluB) develop many of the biochemical features of Reye's Syndrome (RS). To determine whether these also include abnormal circulating lipid, we examined serum lipid profiles in the mouse model throughout the treatment course using Iatroscan-TH10. Following 10 days of exposure to surfactant, serum phospholipid and cholesterol levels were significantly reduced relative to control animals. These reductions were transient; however, four days following virus administration, significant differences in serum lipid were again evident. These abnormalities coincided and correlated with increased animal mortality. Animals that received combined Tox + virus treatment had significant decreases in serum total lipids relative to control animals, a reflection of a reduction in all lipid classes, including phospholipid, cholesterol, neutral glycerides (triglycerides plus diglycerides) and free fatty acids. Phospholipid (specifically phosphatidylcholine and lysophosphatidylcholine) and free fatty acid levels in the Tox + virus group were also significantly lower than those in animals that received virus alone. This study has demonstrated that suckling mice given chemical/viral treatment have the serum hypopanlipidemia but not the freefattyacidemia that are characteristic of RS.

Animals↗
PubMed1992

Lipids of the earthworm Lumbricus terrestris.

The lipid composition of the earthworm Lumbricus terrestris has been reexamined under conditions intended to avoid enzymatic and chemical alterations during storage, extraction, and fractionation procedures. The simple lipids included aliphatic hydrocarbons, steryl esters, glycerides, and at least nine different sterols, all thought to be derived from the diet. Free fatty acids, previously considered to be major components of worm lipids, comprised only 0.3% of the total lipid weight. Phospholipids included (in order of relative abundance) phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol, as well as sphingomyelin. Glycolipids included cerebrosides and sulfatides containing both glucose and galactose, and gangliosides containing glucosamine and sialic acid. The fatty acid compositions of these lipid classes appeared to be a mixture of what are considered typical plant, bacterial, and animal acids. Several fatty acids found in the worms, including cis-vaccenic and eicosapentaenoic acids, were essentially absent from the dietary components, and it is concluded that these acids were synthesized in the worms. The earthworm derives much of its lipid adventitiously, but exerts at least some control over its tissue lipid composition.

Animals↗
PubMed1992

The absorption of fish oils and concentrates.

Both preventive and curative therapies have created a considerable demand for eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. The most common sources for omega 3 fatty acids are fish oil. The concentrations of EPA and DHA in commercial oils, after modest enrichment, reach about 300 mg/g; alternative technologies can produce reasonably priced fish oils containing 400 or even 500 mg/g of omega 3 acids. When the acids are liberated from the glycerides, concentrates of ethyl esters or free acids with 65 to 70% total omega 3 fatty acids (at least 50% EPA + DHA) are readily prepared. Difficulties have arisen because most clinical trials have used fish oils of unspecified composition, and some trials are now based on either ethyl esters or free acids. There are at least three different, but not mutually exclusive, absorption routes in humans, namely the preduodenal route, the lymphatic route via chylomicrons, and the route via the portal vein to the liver. This makes it difficult to compare results. The difficulty in obtaining dose-related clinical data may in part be due to the form in which the omega 3 acids are offered and due in part to the natural presence of these fatty acids in the body. The nontriglyceride forms, especially the free acids, have been advocated for standardization of trials to facilitate interlaboratory comparisons.

Absorption↗
PubMed1988

Lipid abnormalities in pancreatic tissue of streptozotocin-induced diabetic rats.

Pancreatic lipid and fatty acid composition was determined in streptozotocin-induced diabetic rats and compared to control and insulin-treated diabetic rats. A pronounced decrease of total fatty acids was recorded and mainly accounted for by a drop of fatty acids in glycerides. Cholesterol, on the other hand, was significantly increased two- to three-fold, leading to an elevated cholesterol/phospholipid ratio. Morpho-cytochemical studies confirmed these findings because the multiple lipid droplets present in acinar cells of diabetic animals were found to be of cholesterol nature. The major alterations in phospholipid-fatty acid composition were characterized by an increase of linoleate coupled to a decrease of monounsaturates and arachidonate, suggesting defective metabolism of saturates and of linoleate. This was further supported by fatty acid ratios that suggested low delta 5 and delta 9 desaturation. Daily administration of insulin for 10 days restored and overcorrected the various lipid alterations. This study suggests that there are alterations in lipid composition and metabolism in the exocrine pancreas of chronic streptozotocin-induced diabetic rats. Their possible role in the mechanism regulating pancreatic function and secretion remains to be elucidated.

Animals↗
PubMed1987

Medium chain triglycerides and structured lipids.

Lipids are an essential component of our body composition and necessary in our daily food intake. Conventional fats and oils are composed of glycerides of long chain fatty acids and are designated as long chain triglycerides (LCT). Body fat as well as the fats and oils in our daily intake fall into this category. In enteral and parenteral hyperalimentation, we can identify such LCT fats and oils. Soy, corn, safflower and sunflowerseed oils are typical of the LCT oils. In the search for alternative noncarbohydrate fuels, medium chain triglycerides (MCT) are unique and have established themselves in the areas of malabsorption syndrome cases and infant care and as a high energy, rapidly available fuel. Structure lipids with a MCT backbone and linoleic acid built into the triglyceride molecule have been developed to optimize the triglyceride structure that is best for patients, particularly the critically ill. Structured lipids with built-in essential fatty acid components or other polyunsaturated fatty acids promise greater flexibility in patient care and nitrogen support.

Animals↗
PubMed2006

Enhanced transdermal delivery of pranoprofen from the bioadhesive gels.

Percutaneous delivery of NSAIDs has advantages of avoiding hepatic first pass effect and delivering the drug for extended period of time at a sustained, concentrated level at the inflammation site that mainly acts at the joint and the related regions. To develop the new topical formulations of pranoprofen that have suitable bioadhesion, the gel was formulated using hydroxypropyl methylcellulose (HPMC) and poloxamer 407. The effects of temperature on drug release was performed at 32 degrees C, 37 degrees C and 42 degrees C according to drug concentration of 0.04%, 0.08%, 0.12%, 0.16%, and 0.2% (w/w) using synthetic cellulose membrane at 37+/-0.5 degrees C. The increase of temperature showed the increased drug release. The activation energy (Ea), which were calculated from the slope of lop P versus 1000/T plots was 11.22 kcal/ mol for 0.04%, 10.79 kcal/mol for 0.08%, 10.41 kcal/mol for 0.12% and 8.88 kcal/mol for 0.16% loading dose from the pranoprofen gel. To increase the drug permeation, some kinds of penetration enhancers such as the ethylene glycols, the propylene glycols, the glycerides, the non-ionic surfactants and the fatty acids were incorporated in the gel formulation. Among the various enhancers used, propylene glycol mono laurate showed the highest enhancing effects with the enhancement factor of 2.74. The results of this study suggest that development of topical gel formulation of pranoprofen containing an enhancer is feasible.

Adhesives↗
PubMedDate not supplied

Cardiovascular actions of cannabinoids and their generation during shock.

Marijuana is a widely abused recreational drug well known for its psychoactive properties. Cannabinoids, the active ingredients of marijuana, elicit their neurobehavioral effects by interacting with the CB1 cannabinoid receptor subtype, expressed primarily in the brain but also present in some peripheral tissues. A second receptor subtype, the CB2 receptor, is expressed on cells of the immune system and is thought to be responsible for the immunosuppressant effects of cannabinoids. Recently, endogenous lipidlike substances have been identified, including arachidonyl ethanolamide (anandamide) and 2-arachidonyl glyceride, that bind to cannabinoid receptors and mimic many of the neurobehavioral effects of plant-derived cannabinoids. Both plant-derived cannabinoids and the endogenous ligands have been shown to elicit hypotension and bradycardia via activation of peripherally located CB1 receptors. Possible underlying mechanisms include presynaptic CB1 receptor mediated inhibition of norepinephrine release from peripheral sympathetic nerve terminals, and/or direct vasodilation via activation of vascular cannabinoid receptors. The latter may also be the target of endocannabinoids of vascular endothelial origin. Recent studies indicate that a peripheral endogenous cannabinoid system in circulating macrophages and platelets is activated in hemorrhagic and septic shock and may contribute to the hypotension associated with these conditions via activation of vascular cannabinoid receptors. The potential role of this mechanism in human shock conditions is under investigation.

Animals↗
PubMed2006

Anandamide absorption by direct hemoperfusion with polymixin B-immobilized fiber improves the prognosis and organ failure assessment score in patients with sepsis.

PURPOSE: Direct hemoperfusion (DHP) with polymixin B-immobilized fiber (PMX) has been reported to be effective for patients with septic shock. The aim of this study was to clarify the mechanism of PMX-DHP effect on septic shock. METHODS: The following parameters were measured in septic shock patients who were treated with PMX-DHP: survival rate, sepsis-related organ failure assessment (SOFA) score, acute physiology and chronic health evaluation II (APACHE-II) score, and plasma concentrations of cannabinoids [anandamide (ANA) and 2-arachidonyl glyceride (2-AG)], cytokines [interleukin (IL)-6, IL-8, IL-10], transforming growth factor beta (TGF-beta), and calcitonin gene-related peptide (CGRP)]. The primary end point was mortality from all causes at day 28 after intensive care unit (ICU) admission or discharge. RESULTS: The survival rate of all patients at 28 days after ICU admission was 37.5% (9/24). The survival group showed significantly lower SOFA and APACHE-II scores than the nonsurvival group after PMX-DHP treatment (P = 0.008 and 0.028, respectively). The improved SOFA score group showed a better survival rate than the nonimproved SOFA score group (71.4% versus 23.5%, P = 0.028). Plasma ANA level significantly decreased after PMX-DHP treatment both in the improved SOFA score group and in the survival group. The level of 2-AG, however, showed no significant change in either group. CONCLUSION: ANA, an intrinsic cannabinoid that induces hypotension in septic shock, is inferred to be the main mechanism of the PMX-DHP effect. Removal of ANA by PMX-DHP could be key to successful septic shock treatment.

APACHE↗
PubMed2002

In vitro effects of fat, FA, and cholesterol on sphingomyelin hydrolysis induced by rat intestinal alkaline sphingomyelinase.

Dietary sphingomyelin (SM) may have regulatory effects on cell proliferation and tumorigenesis in the colon. Alkaline sphingomyelinase (SMase) is the major enzyme responsible for hydrolysis of SM in the gut. Previously we purified the enzyme and showed that the presence of glycerophospholipids inhibited SM hydrolysis induced by alkaline SMase in vitro. In the present work, we studied the effects of TG, DG, FA, ceramide, and cholesterol on SM hydrolysis catalyzed by purified alkaline SMase. The results showed that both TG (triolein and tristearin) and DG (1,2-dioleoyl-sn-glycerol and 1,2-distearoyl-rac-glycerol) inhibited the activity of alkaline SMase. 1-Monooleoyl-rac-glycerol, 1-monostearoyl-rac-glycerol, stearic acid, oleic acid, linoleic acid, linolenic acid, and arachidonic acid stimulated the activity of alkaline SMase at 0.4-0.8 mM concentrations but inhibited the enzyme at higher concentrations. There was no difference between the effects induced by saturated and unsaturated FA. A short-chain FA such as lauric acid had a stronger stimulatory effect at low concentrations and weaker inhibitory effect at high concentrations than long-chain FA. Choosing linoleic acid as an example, we found that FA had similar effects on both alkaline SMase and neutral SMase. Cholesterol and ceramide when mixed with FA to increase its solubility in bile salt micelles inhibited SMase activity. In conclusion, glycerides, FA, ceramide, and cholesterol influence SM hydrolysis catalyzed by intestinal alkaline SMase. The presence of lipids in the diet may thus influence the course of SM digestion in the gut and thereby the exposure of colon to SM metabolites.

Animals↗
PubMed1998

Simultaneous quantitation of ceramides and 1,2-diacylglycerol in tissues by Iatroscan thin-layer chromatography-flame-ionization detection.

Ceramides and 1,2-diacylglycerol have been demonstrated in intracellular signaling pathways. A method of simultaneous mass determination of ceramides and 1,2-diacylglycerol in tissues was developed using the latroscan which combines thin layer chromatography and flame ionization detection (TLC/FID) techniques. Because of relatively low amounts of these components in tissues, the fraction of nonpolar lipids, which included ceramides and glycerides, was eluted with chloroform/acetone mixture (3:1, vol/vol) through a silicic acid column to eliminate the polar phospholipids. Development of Chromarods was carried out using three solvent systems in a four-step development technique. The relationship of the peak area ratio to weight ratio compared with cholesteryl acetate added as an internal standard was linear. The amount of ceramides increased with incubation of rat heart homogenate and human erythrocyte membranes in the presence of sphingomyelinase (E.C. 3.1.4.12). The latroscan TLC/FID system provided a quick and reliable assessment of ceramides and 1,2-diacylglycerol.

Animals↗
PubMed1975

Multiple myeloma, cryoglobulinemia and xanthomatosis. Distinct clinical and biochemical syndromes in two patients.

Studies were carried out in two patients with multiple myeloma (immunoglobulin G, [IgG], K light chain), cryoglobulinemia and xanthomatosis with clinical features and lipid transport abnormalities which were quite different. One patient had nodular xanthomatosis and lipemia with delayed triglyceride and apolipoprotein removal. In vivo heparin resistance was present and heparin-paraprotein interaction was shown in vitro. The lipoprotein removal defect may have been due to impaired uptake of the "remnants" of glyceride-rich lipoproteins. Abnormalities were found both in primary platelet aggregation and in the platelet release reaction. The second patient had diffuse plane xanthomatosis with normal lipids. An orange cryoprecipitate contained IgG, beta- and prebeta lipoproteins, albumin, carotenoids and about half of the serumcholesterol. Triglyceride turnover was normal. These observations show that M-proteins may interfere with lipid transport by at least two mechanisms and illustrate the clinical diversity of xanthomatous myeloma.

Adult↗