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PubMed1992

The mode of action of lipid-soluble antioxidants in biological membranes. Relationship between the effects of ubiquinol and vitamin E as inhibitors of lipid peroxidation in submitochondrial particles.

The effects of ubiquinol and vitamin E on ascorbate- and ADP-Fe(3+)-induced lipid peroxidation were investigated in beef heart submitochondrial particles before and after extraction of ubiquinone and vitamin E, and after reincorporation of either or both of these components. It is concluded that ubiquinol is capable of inhibiting lipid peroxidation without the mediation of vitamin E, but may also amplify the antioxidant effect of the latter. It is pointed out that ubiquinol is the only known lipid-soluble antioxidant that can be synthesized de novo in animal cells, and for which there exists an enzymic mechanism--the mitochondrial electron-transport system--that can regenerate the antioxidant from its oxidized form resulting from its inhibitory effect on lipid peroxidation. These features, together with its high degree of hydrophobicity and its general occurrence in biological membrane and in low-density lipoprotein, suggest a highly important role of ubiquinol in cellular defense against oxidative damage.

Animals↗
PubMed2003

Life style and cardiovascular risk factors in the Japanese population--from an epidemiological survey on serum lipid levels in Japan 1990 part 2: association of lipid parameters with hypertension.

The importance of metabolic syndrome as a risk factor of coronary artery disease (CAD) has recently become more and more recognized. In view of such a background, changes in cholesterol and other lipid parameters in the Japanese population associated with excess body weight and hypertension were analyzed in this study based on data obtained in an epidemiological survey carried out in 1990. Hypertension was closely associated with a higher body mass index (BMI). Among the lipid parameters, triglyceride (TG) and non-HDL-C (total cholesterol minus HDL-cholesterol) levels showed remarkable differences between hypertensive and normotensive subjects, with a greater statistical significance than LDL-cholesterol (LDL-C) levels. Changes in lipid parameters in the presence of hypertension were mostly associated with an increase in BMI in younger men aged 20-39, while increases in TG levels took place independently of excess body weight in middle-aged (40-59-year old) men. Considering that hypertension is a common and the greatest risk factor in the Japanese population, TG and non-HDL-C appear to be more important than LDL-C as major lipid parameters related to atherogenesis.

Adult↗
PubMed1996

Current state of and recent trends in serum lipid levels in the general Japanese population. Research Committee on Serum Lipid Level Survey 1990 in Japan.

To determine the recent serum lipid levels in the general Japanese population and trends in their changes over the past 30 years, a nationwide survey of serum lipid levels was conducted in 39 institutes from various districts around Japan. The total number of subjects were 34,815, consisting of 20,279 men and 14,536 women aged 4 through 99 years. All the serum samples were collected and analyzed within one week at the Special Research Laboratory (Tokyo, Japan). In males, the mean serum cholesterol level showed a gradually increase from 170 mg/dl in the 0- to 9-year-old age group to 198 mg/dl in the 50- to 59-year-old age group. There was a slight decrease after age 60 years. In females, the mean cholesterol level gradually rose with age from 173 mg/dl in the 0- to 9-year-old age group to 210 mg/dl in the 60- to 69-year-old age group, and fell to 207 mg/dl after 80 years of age. The mean HDL-cholesterol level in men gradually decreased with age from 60 mg/dl in the 0- to 9-year-old age group to 51 mg/dl in the 30- to 39-year-old age group, remained at this level up to 69 years of age, and then increased to 54 mg/dl for the above 80 years old group. The mean HDL-cholesterol level in women increased from 57 mg/dl in the 0- to 9-year-old age group to 62 mg/dl for the 20- to 29-year-old age group: then gradually decreased with age to 54 mg/dl in the 60- to 79-year-old age group. The mean LDL-cholesterol level in men gradually increased with age from 98 mg/dl in the 0- to 19-year-old age group to 122 mg/dl at 70-79 years of age. The mean LDL-cholesterol level in women was low at 101-103 mg/dl up to 29 years of age, then it increased with age to 135 mg/dl in the 60- to 69-year-old age group. The serum cholesterol levels in 1970 and 1980 were higher than that in 1960, but in 1990 values similar to those in 1960 were observed in both men and women. The present results will become the standard serum lipid level data for the Japanese people, and succeeding 10-year surveys will clarify the trends of lipid levels in this country.

Adolescent↗
PubMedDate not supplied

[Determination of the cercarial lipids and relations with superficial human cutaneous lipids (author's transl)].

The lipid class composition of cercariae of Schistosoma mansoni and skin surface has been examined by thin lager chromatography. Free sterols, sterol esters, triglycerides, phospholipids were major components of cercarial lipids, triglycerides, wax esters, free fatty acids, squalen were major components of skin surface lipids. An examination of fatty acids of total cercarial and skin surface lipids revealed that C16, C18, C18=, C16=, C18= were major components.

Chromatography, Gas↗
PubMed2001

[Effects of nutritional intervention on anthropometric variables, intake, serum lipids concentrations and plasma lipids and lipoproteins in dyslipidemic children].

The purpose of this study was to evaluate the effect of the individualized nutritional intervention on: 1) Anthropometric variables; 2) Changes in lipid intake variables; 3) Changes in plasma lipids concentrations. The relationship between the initial and final difference in plasma lipid concentrations and the quality of the intake was analyzed. The nutritional intervention was provided in a four-month period to a 27 dyslipidemic children. The results indicate that individualized nutritional intervention favors weight loss and reduction of fat indicators in overweight children with adequate proteic and caloric reserves, not affecting the normal growing process. Those children with normal weight and caloric reserves maintained them without affecting growth. The nutritional intervention also had a beneficial effect on those variables related to dietary intake. The reduction of the saturated fat and cholesterol intake in dyslipidemic children resulted in a significant decrease in total plasma concentration of cholesterol and LDL-C lipoproteins (11% and 17%, respectively). These results show the importance of nutritional intervention in dyslipidemic children since it seems an efficient way for prevention, control and treatment of lipid metabolic disorders over lipemic reducing drugs.

Anthropometry↗
PubMed2002

Macrophages are associated with lipid-rich carotid artery plaques, echolucency on B-mode imaging, and elevated plasma lipid levels.

OBJECTIVE: Atherosclerosis may be regarded as an inflammatory disease dominated by macrophages. We tested whether macrophages in carotid artery atherosclerotic plaques are associated with echolucency on B-mode ultrasound imaging, lipid levels, inflammatory markers, and aspirin use. METHODS: We studied 106 patients undergoing carotid endarterectomy having >/=50% carotid artery stenosis and previous ipsilateral hemispheric neurologic symptoms. RESULTS: Macrophages were particularly common in plaques with a high content of lipid and hemorrhage and, conversely, rare in plaques dominated by calcification and fibrous tissue. Macrophage density in carotid artery plaques classified by B-mode ultrasound imaging as echolucent (n = 56), intermediate (n = 25), or echorich (n = 25) was 1.8% +/- 0.2%, 1.5% +/- 0.4%, and 1.0% +/- 0.2% (+/-SE), respectively (analysis of variance, P =.02). A computer-generated measure of plaque echolucency, gray-scale median, was associated with increased macrophage density (r = -0.31; P =.002). Furthermore, plasma and low-density lipoprotein cholesterol levels were associated with carotid artery macrophage density (r = 0.26, P =.008 and r = 0.23, P =.02); this was most pronounced in patients with lipid-rich plaques. Macrophage density was not associated with plasma levels of acute-phase reactants. Finally, macrophage density in carotid artery plaques of users (n = 55) and nonusers of aspirin (n = 51) was 1.2% +/- 0.2% and 1.8% +/- 0.2% (t test, P =.01). CONCLUSIONS: Increased macrophage density in carotid atherosclerotic plaques was associated with lipid content, plaque echolucency, and increased plasma and low-density lipoprotein cholesterol levels. Furthermore, use of aspirin was associated with reduced macrophage density in carotid artery plaques.

Analysis of Variance↗
PubMed2001

Anion binding to lipid bilayers: a study using fluorescent lipid probes.

Anion-induced fluorescence quenching of lipid probes incorporated into the liposomal membrane was used to study the binding of anions to the lipid membrane. Lipid derivatives bearing nonpolar fluorophore located either in the proximity of the polar headgroups (anthrylvinyl-labelled phosphatidylcholine, ApPC; methyl 4-pyrenylbutyrate, MPB) or in the polar region (rhodamine 19 oleyl ester, OR19) of the bilayer were used as probes. The binding of iodide to the bilayers of different compositions was studied. Based on the anion-induced quenching of the fluorescence, the isotherm of adsorption of the quencher (iodide) to the membrane was plotted. For anions, which are non-quenchers or weak quenchers (thiocyanate, perchlorate or trichloroacetate), the binding parameters were obtained from the data of the competitive displacement of iodide by these anions. The association constants of the anion binding to the bilayer (Ka) were determined for the stoichiometry of 1 ion/1 lipid and also for the case of independent anion binding. At the physiological concentration of the salt, which does not bind noticeably to the membrane (150 mM NaCl), anion binding could be satisfactorily described by the Langmuir isotherm. The approach applied here offers new possibilities for the studies of ion-membrane interactions using fluorescent probes.

Anions↗
PubMed1992

Protein deficiency and excess lipid synergistically augmented lipid peroxidation in growing rats.

The influence of dietary protein and lipid on superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (GSH) and tissue lipid peroxidation, as measured by thiobarbituric acid-reactive substances (TBARS), was investigated in post-weaning male Wistar rats, fed either a diet containing 5% or 20% corn oil with 5%, 10% or 20% soy protein isolate (SPI) for four weeks. TBARS concentrations in 5% corn oil group was highest in 5% SPI group for all organs, followed by 10 and 20% SPI groups in the liver and 10 and 20% SPI groups in other organs. High lipid diet significantly increased TBARS formation in the liver of 10% SPI group. The liver and kidney SOD and GPx activities were higher in 5% and 10% SPI groups than in 20% SPI group, suggesting an augmented formation of radical substrates for these enzymes in low protein groups. Organ GSH concentrations did not show a linear correlation with dietary protein level. These results suggest that protein deficiency along with high lipid intake accelerates the peroxidative damage of the tissues by increasing oxy-radical formations and/or decreasing the defense mechanism.

Animals↗
PubMed2006

Preparation, characterization and physico-chemical properties of solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC): their benefits as colloidal drug carrier systems.

Solid lipid nanoparticles (SLN) have attracted increasing attention by various research groups and companies since the early 1990s. Their advantages over existing traditional carriers have been clearly documented. In addition, modified SLN have been described which are nanostructured lipid carriers (NLC) composed of liquid lipid blended with a solid lipid to form a nanostructured solid particle matrix. NLC combine controlled release characteristics with some advantages over SLN. This paper reviews the production techniques, characterization and physical stability of these systems including destabilizing factors and principles of drug loading, then considers aspects and benefits of SLN and NLC as colloidal drug carriers.

Chemical Phenomena↗
PubMed1977

Lipid A mutants of Salmonella typhimurium. Purification and characterization of a lipid A precursor produced by a mutant in 3-deoxy-D-mannooctulosonate-8-phosphate synthetase.

We describe here the isolation, purification, and structural characterization of a lipid A precursor synthesized under nonpermissive conditions by a mutant of Salmonella typhimurium conditionally defective in the synthesis of the 3-deoxy-D-mannoctulosonate (2-keto-3-deoxyoctonate, KDO) region of the lipopolysaccharide. The precursor was isolated free from lipopolysaccharide, murein, and phospholipids by extraction of delipidated cells with 90% phenol/CHCL3/petroleum ether. The molecule was recovered from the phenol phase after precipitation of lipopolysaccharide with H2O and subsequently purified by DEAE-cellulose chromatography. Structural analyses showed that the lipid A precursor is a phosphorylated glucosamine disaccharide containing one ester and two amide-linked residues of beta-hydroxymyristate. In contrast to lipid A, the precursor disaccharide lacks ester-linked 12:0 and 14:0 fatty acids as well as KDO. The molecule contains 2 phosphate residues both of which were identified as phosphomonoesters by 31P NMR spectroscopy. One of the phosphomonoesters is located in position 1 of the reducing terminal glucosamine residue; the location of the other phosphomonoester was not determined. The structure of the precursor provides strong support for the conclusion that KDO incorporation occurs at an early stage in lipid A biosynthesis prior to the incorporation of ester-linked saturated fatty acids.

Aldehyde-Lyases↗
PubMed1991

[Relation between hepatic lipid metabolism and the formation of lipid plaques in the rabbit aorta in an experimental model of atherosclerosis].

The objective of the work was to follow up on a model of experimental atherosclerosis induced in rabbits by a 1% cholesterol diet the mutual relationship of the deposition of total cholesterol as well as esterified and free fatty acids in the liver and the formation of lipid plaques in the rabbit aorta. The authors investigated also the influence exerted on this process by the s.c. administration of calcium antagonists--Verapamil 0.25 mg.kg-1.day-1 (Lek Ljubl., Jugoslavia), Dilthiazem 2 mg.kg-1.day-1 (Lachema CSFR) and Isradipine 2.5 mg.kg-1.day-1 (Isradipine--N Sandoz, Ltd, Switzerland). The interference of calcium antagonists with the lipid metabolism in the liver as well as the transport mechanism of lipids in the blood stream is differentiated. Verapamil administered in therapeutic doses promotes HDL-cholesterol formation and thus hastens the cholesterol transport from the blood stream into the liver where the latter cumulates. This may be one of the mechanisms of the antiatherogenic action of verapamil. On the other hand, isradipine and in particular dilthiazem administered in treble doses, as compared with therapeutic doses, slightly potentiated the formation of lipid plaques in the rabbit aorta and reduced the HDL-cholesterol level and thus also the cholesterol shift to the liver.

Animals↗
PubMedDate not supplied

[Respiratory organ lipids in fishes and mammals. A model representation of the area of the lipid component].

Studies have been made on lipid composition of the gills in 19 species of fishes and of the lungs in 8 mammalian species. It was shown that the arbitrary "unit fragment" of the lipid component of the respiratory organs in all the investigated animals exhibits similar qualitative composition, but contains different quantity of lipid molecules, i. e. approximately 19 in fishes and 42 in mammals. Theoretical conformational analysis revealed predominant conformations of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin and cholesterol; projections of these molecules on the surface which is parallel to membrane surface were composed. It was shown that projectional areas for the main phospholipid molecules differ only by 2-3%. These data indicate that the surface of a model of the lipid component in the membranes of respiratory organs in mammals is twice larger than in fishes. These differences presumably account for more effective oxygen transfer in mammals.

Animals↗
PubMed1976

The action of arterial hypertension on lipid and lipoprotein metabolism. II. Qualitative and quantitative alterations of blood serum, liver and aortic lipids and lipoproteins in Okamoto-Aoki rats with spontaneous hypertension.

The purpose of the study was to investigate alterations in the content of the basic lipid fractions, and of the low density lipoproteins (LDL) in the liver, the blood serum and aorta, as well as to determine by acrylamide disc electrophoresis the hyperlipoproteinaemic type of spontaneously hypertensive rats (SHR) which are considered as the most suitable model of essential hypertension. The experiments were carried out on 25 normotensive control Wistar rats and 30 SHR (Okamoto-Aoki strain). An augmentation of lipid metabolism in the liver and a moderate hyperlipidaemia mainly due to an increase in triglycerides was found. The quantitative alterations of the lipid fractions corresponded with the qualitative alterations of the lipoproteins, an intensive and permanent pre-beta-LP fraction being established. In all the SHR a peculiar pattern of hyperlipoproteinaemia differing from the basic Fredickson-Lees patterns by a LP-fraction located between tha alpha- and beta-LP fractions was also established. The alterations in the lipid and lipoprotein metabolism in SHR are considered as connected with the hypertensive state itself since no accompanying atherosclerosis was observed.

Animals↗
PubMed1991

Activation of 5-[125I]iodonaphthyl-1-azide via excitation of fluorescent (N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)) lipid analogs in living cells. A potential tool for identification of compartment-specific proteins and proteins involved in intracellular transport and metabolism of lipids.

We describe a new technique for analysis of proteins located near fluorescent lipid analogs in intact living cells using the membrane-permeant, photoactivatable probe, 5-[125I]iodonaphthyl-1-azide ([125I]INA). [125I] INA can be activated directly with UV light or indirectly through excitation of adjacent fluorophores (photosensitizers) with visible light to modify nearby proteins covalently with 125I. In this report we demonstrate that fluorescent phospholipids and sphingolipids containing N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-6-aminocaproic acid serve as appropriate photosensitizers for [125I]INA. Using Chinese hamster ovary fibroblasts, we optimized the labeling conditions with respect to lipid concentration and time of irradiation and then examined the profiles of cellular proteins that were labeled when fluorescent analogs of ceramide, sphingomyelin, and phosphatidic acid were used as photosensitizers in living cells. The use of different fluorescent lipids, which label different subcellular compartments of cells as determined by fluorescence microscopy, derivatized different sets of cellular proteins with 125I. The labeled proteins were subsets of the total set of proteins available for derivatization as determined by direct activation of [125I]INA. Most proteins labeled by this procedure were pelleted by centrifugation of cell lysates at high speed (260,000 x g), but several soluble proteins were also labeled under these conditions. The implications of using this technique for identification of compartment-specific proteins and proteins involved in lipid metabolism and transport are discussed.

4-Chloro-7-nitrobenzofurazan↗
PubMed1991

[A study of lipid peroxidation in neonates--(1) Daily change of serum lipid peroxides in full term neonates].

Lipid peroxide has been highlighted as a possible marker of cell destruction by oxygen derived free radical reactions. We, therefore, examined serum lipid peroxides, malondialdehydes (MDA) in 106 healthy full term neonates (aged 0.5 to 317 hrs, averaged 79.3 +/- 69.9 hrs). Their lipid peroxides in capillary blood were determined by the luminescence method (Yagi method). Based on our data, we conclude as follows: 1) MDA concentrations were influenced by the serum bilirubin concentrations. We, therefore, adjusted our data according to the serum bilirubin concentrations. 2) We found significantly higher values of MDA (4.76 +/- 1.35 nmol.ml-1) than those in adult (3.12 +/- 0.35 nmol.ml-1). In fact, these values increased gradually on the second day, and the high values were maintained until the fifth day. 3) The values of MDA and total bilirubin concentrations in the vaginally delivered neonates were significantly higher than those delivered by Cesarean section (P less than 0.05). 4) There were no correlations between the values of MDA and values of other serum lipid and bilirubin.

Humans↗
PubMed1990

[The lipids of mycelial fungi and the prospects for the development of microbial oleo-biotechnology. I. The lipids of mycelial fungi].

The importance of mycelial fungi as a source of lipids for development of modern oleo biotechnology is considered. For this purpose the data on fungal lipid composition and the main enzymes of fatty acid synthesis in fungi as compared with procaryotes and higher eucaryotes as well the data on the effect of a number of physicochemical factors on the yield and composition of the lipids of the micromycetes are presented. The information on the fungi producers according to the lipid composition able to substitute the vegetable oil and be the source of linolic, linolenic and arachidonic acids is put forward.

Biotechnology↗
PubMed1979

Biosynthesis of lipid-linked oligosaccharides. Isolation and structure of a second lipid-linked oligosaccharide in Chinese hamster ovary cells.

Previous work has shown that vesicular stomatitis virus-infected Chinese hamster ovary cells contain a major high molecular weight lipid-linked oligosaccharide which is transferred en bloc to protein during the formation of the asparagine-linked complex-type oligosaccharides of the vesicular stomatitis virus G protein (Tabas, I., Schlesinger, S., and Kornfeld, S. (1978) J. Biol. Chem. 253, 716-722). We now report the characterization of a second, lower molecular weight lipid-linked oligosaccharide. The oligosaccharide portion of this molecule was isolated and its structure was determined by methylation analysis, digestion with exoglycosidases, acetolysis and Smith periodate degradation to be: (formula: see text). Several lines of evidence are presented which indicate that this lipid-linked oligosaccharide is primarily involved in the assembly of the major lipid-linked oligosaccharide rather than in the direct glycosylation of proteins.

Animals↗
PubMed1985

Activation of murine spleen cells by lipid A: negative modulation of lipid A mitogenic activity by O-antigen polysaccharide.

We have investigated the regulatory effects of polysaccharide-rich subunits upon lipid A activity with the use of hybrid LPS macromolecules of defined subunit composition. Hybrid LPS were constructed with polysaccharide-rich LPS from Escherichia coli O55:B5 and lipid A-rich LPS from Salmonella minnesota R595 by dissociation of the two parental LPS species to monomeric solutions with deoxycholate, admixing these LPS in various proportions and reassociation into high m.w. LPS hybrid aggregates by removal of the deoxycholate. Isopycnic densities of LPS hybrids were intermediate to those of the two parental LPS species, confirming the formation of true hybrids. Murine spleen cell proliferative responses induced by hybrid LPS macromolecules were also intermediate to those obtained with parental LPS but significantly less than would be anticipated on the basis of total lipid A content. These results demonstrate that the polysaccharide portion of LPS can negatively regulate the expression of lipid A in LPS micellar aggregates.

Animals↗