WorldWideScience

Sample records for cholesterol constrains glycolipid

  1. A fluorescent glycolipid-binding peptide probe traces cholesterol dependent microdomain-derived trafficking pathways.

    Directory of Open Access Journals (Sweden)

    Steffen Steinert

    Full Text Available BACKGROUND: The uptake and intracellular trafficking of sphingolipids, which self-associate into plasma membrane microdomains, is associated with many pathological conditions, including viral and toxin infection, lipid storage disease, and neurodegenerative disease. However, the means available to label the trafficking pathways of sphingolipids in live cells are extremely limited. In order to address this problem, we have developed an exogenous, non-toxic probe consisting of a 25-amino acid sphingolipid binding domain, the SBD, derived from the amyloid peptide Abeta, and conjugated by a neutral linker with an organic fluorophore. The current work presents the characterization of the sphingolipid binding and live cell trafficking of this novel probe, the SBD peptide. SBD was the name given to a motif originally recognized by Fantini et al in a number of glycolipid-associated proteins, and was proposed to interact with sphingolipids in membrane microdomains. METHODOLOGY/PRINCIPAL FINDINGS: In accordance with Fantini's model, optimal SBD binding to membranes depends on the presence of sphingolipids and cholesterol. In synthetic membrane binding assays, SBD interacts preferentially with raft-like lipid mixtures containing sphingomyelin, cholesterol, and complex gangliosides in a pH-dependent manner, but is less glycolipid-specific than Cholera toxin B (CtxB. Using quantitative time-course colocalization in live cells, we show that the uptake and intracellular trafficking route of SBD is unlike that of either the non-raft marker Transferrin or the raft markers CtxB and Flotillin2-GFP. However, SBD traverses an endolysosomal route that partially intersects with raft-associated pathways, with a major portion being diverted at a late time point to rab11-positive recycling endosomes. Trafficking of SBD to acidified compartments is strongly disrupted by cholesterol perturbations, consistent with the regulation of sphingolipid trafficking by cholesterol

  2. Cholesterol, sphingolipids, and glycolipids: What do we know about their role in raft-like membranes?

    DEFF Research Database (Denmark)

    Rog, T.; Vattulainen, I.

    2014-01-01

    Lipids rafts are considered to be functional nanoscale membrane domains enriched in cholesterol and sphingolipids, characteristic in particular of the external leaflet of cell membranes. Lipids, together with membrane-associated proteins, are therefore considered to form nanoscale units...... emerged based on recent atomistic and coarse-grained molecular dynamics simulation studies on the key lipid raft components, which include cholesterol, sphingolipids, glycolipids, and the proteins interacting with these classes of lipids. The simulation results are compared to experiments when possible...... with potential specific functions. Although the understanding of the structure of rafts in living cells is quite limited, the possible functions of rafts are widely discussed in the literature, highlighting their importance in cellular functions. In this review, we discuss the understanding of rafts that has...

  3. Glycolipid binding preferences of Shiga toxin variants.

    Directory of Open Access Journals (Sweden)

    Sayali S Karve

    Full Text Available The major virulence factor of Shiga toxin producing E. coli, is Shiga toxin (Stx, an AB5 toxin that consists of a ribosomal RNA-cleaving A-subunit surrounded by a pentamer of receptor-binding B subunits. The two major isoforms, Stx1 and Stx2, and Stx2 variants (Stx2a-h significantly differ in toxicity. The exact reason for this toxicity difference is unknown, however different receptor binding preferences are speculated to play a role. Previous studies used enzyme linked immunosorbent assay (ELISA to study binding of Stx1 and Stx2a toxoids to glycolipid receptors. Here, we studied binding of holotoxin and B-subunits of Stx1, Stx2a, Stx2b, Stx2c and Stx2d to glycolipid receptors globotriaosylceramide (Gb3 and globotetraosylceramide (Gb4 in the presence of cell membrane components such as phosphatidylcholine (PC, cholesterol (Ch and other neutral glycolipids. In the absence of PC and Ch, holotoxins of Stx2 variants bound to mixtures of Gb3 with other glycolipids but not to Gb3 or Gb4 alone. Binding of all Stx holotoxins significantly increased in the presence of PC and Ch. Previously, Stx2a has been shown to form a less stable B-pentamer compared to Stx1. However, its effect on glycolipid receptor binding is unknown. In this study, we showed that even in the absence of the A-subunit, the B-subunits of both Stx1 and Stx2a were able to bind to the glycolipids and the more stable B-pentamer formed by Stx1 bound better than the less stable pentamer of Stx2a. B-subunit mutant of Stx1 L41Q, which shows similar stability as Stx2a B-subunits, lacked glycolipid binding, suggesting that pentamerization is more critical for binding of Stx1 than Stx2a.

  4. Glycolipid biosynthesis in cyanobacteria

    International Nuclear Information System (INIS)

    The biosynthesis of monogalactosyldiacyl-glycerol (MGDG) was studied in five different cyanobacteria. Previous work has shown Anabaena variabilis to synthesize both MGDG and monoglucosyl-diacylglycerol (MG1cDG) with MG1cDG being the precursor of MGDG. They have examined four other cyanobacteria to determine if a similar relationship exists. The cyanobacteria studied were Anabaena variabilis, Chlorogloeopsis sp., Schizothrix calcicola, Anacystis nidulans, and Anacystis marina. Each were grown in liquid culture and lipids were labeled with 14C]CO2 for 20 min., 1.0 hr, 1.0 hr + 10 hr chase. Glycolipids were analyzed by initial separation of MGDG and MG1cDG by TLC followed by further analysis by HPLC. Complete separation of molecular species was obtained isocratically on an ODS column. All of the cyanobacteria labeled 16-C and 18-C fatty acids except for A. marina which labeled only 14-C and 16-C fatty acids. Desaturation of the fatty acids could be observed in the 1.0 hr and chase experiments. All were capable of labeling both MG1cDG and MGDG with the precursor-product relationship being observed. There does not appear to be a direct relationship between the epimerization of the sugar moiety and fatty acid desaturation

  5. What's Cholesterol?

    Science.gov (United States)

    ... Skiing, Snowboarding, Skating Crushes What's a Booger? What's Cholesterol? KidsHealth > For Kids > What's Cholesterol? Print A A ... thing for food to be low in it? Cholesterol and Your Body Cholesterol (say: kuh-LES-tuh- ...

  6. DGDG and Glycolipids in Plants and Algae.

    Science.gov (United States)

    Kalisch, Barbara; Dörmann, Peter; Hölzl, Georg

    2016-01-01

    Photosynthetic organelles in plants and algae are characterized by the high abundance of glycolipids, including the galactolipids mono- and digalactosyldiacylglycerol (MGDG, DGDG) and the sulfolipid sulfoquinovosyldiacylglycerol (SQDG). Glycolipids are crucial to maintain an optimal efficiency of photosynthesis. During phosphate limitation, the amounts of DGDG and SQDG increase in the plastids of plants, and DGDG is exported to extraplastidial membranes to replace phospholipids. Algae often use betaine lipids as surrogate for phospholipids. Glucuronosyldiacylglycerol (GlcADG) is a further glycolipid that accumulates under phosphate deprived conditions. In contrast to plants, a number of eukaryotic algae contain very long chain polyunsaturated fatty acids of 20 or more carbon atoms in their glycolipids. The pathways and genes for galactolipid and sulfolipid synthesis are largely conserved between plants, Chlorophyta, Rhodophyta and algae with complex plastids derived from secondary or tertiary endosymbiosis. However, the relative contribution of the endoplasmic reticulum- and plastid-derived lipid pathways for glycolipid synthesis varies between plants and algae. The genes for glycolipid synthesis encode precursor proteins imported into the photosynthetic organelles. While most eukaryotic algae contain the plant-like galactolipid (MGD1, DGD1) and sulfolipid (SQD1, SQD2) synthases, the red alga Cyanidioschyzon harbors a cyanobacterium-type DGDG synthase (DgdA), and the amoeba Paulinella, derived from a more recent endosymbiosis event, contains cyanobacterium-type enzymes for MGDG and DGDG synthesis (MgdA, MgdE, DgdA).

  7. Lectin affinity chromatography of glycolipids

    Energy Technology Data Exchange (ETDEWEB)

    Torres, B.V.; Smith, D.F.

    1987-05-01

    Since glycolipids (GLs) are either insoluble or form mixed micelles in water, lectin affinity chromatography in aqueous systems has not been applied to their separation. They have overcome this problem by using tetrahydrofuran (THF) in the mobile phase during chromatography. Affinity columns prepared with the GalNAc-specific Helix pomatia agglutinin (HPA) and equilibrated in THF specifically bind the (/sup 3/H)oligosaccharide derived from Forssman GL indicating that the immobilized HPA retained its carbohydrate-binding specificity in this solvent. Intact Forssman GL was bound by the HPA-column equilibrated in THF and was specifically eluted with 0.1 mg/ml GalNAc in THF. Purification of the Forssman GL was achieved when a crude lipid extract of sheep erythrocyte membranes was applied to the HPA-column in THF. Non-specifically bound GLs were eluted from the column using a step gradient of aqueous buffer in THF, while the addition of GalNAc was required to elute the specifically bound GLs. Using this procedure the A-active GLs were purified from a crude lipid extract of type A human erythrocytes in a single chromatographic step. The use of solvents that maintain carbohydrate-binding specificity and lipid solubility will permit the application of affinity chromatography on immobilized carbohydrate-binding proteins to intact GLs.

  8. Natural surfactants used in cosmetics: glycolipids.

    Science.gov (United States)

    Lourith, N; Kanlayavattanakul, M

    2009-08-01

    Cosmetic surfactant performs detergency, wetting, emulsifying, solubilizing, dispersing and foaming effects. Adverse reactions of chemical synthesis surfactant have an effect on environment and humans, particularly severe in long term. Biodegradability, low toxicity and ecological acceptability which are the benefits of naturally derived surfactant that promises cosmetic safety are, therefore, highly on demand. Biosurfactant producible from microorganisms exhibiting potential surface properties suitable for cosmetic applications especially incorporate with their biological activities. Sophorolipids, rhamnolipids and mannosylerythritol lipids are the most widely used glycolipids biosurfactant in cosmetics. Literatures and patents relevant to these three glycolipids reviewed were emphasizing on the cosmetic applications including personal care products presenting the cosmetic efficiency, efficacy and economy benefits of glycolipids biosurfactant. PMID:19496839

  9. About Cholesterol

    Science.gov (United States)

    ... High Blood Pressure Tools & Resources Stroke More About Cholesterol Updated:Aug 10,2016 It may surprise you ... our bodies to keep us healthy. What is cholesterol and where does it come from? Cholesterol is ...

  10. Production of glycolipid biosurfactants by basidiomycetous yeasts.

    Science.gov (United States)

    Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2009-05-01

    BSs (biosurfactants) produced by various micro-organisms show unique properties (e.g. mild production conditions, lower toxicity, higher biodegradability and environmental compatibility) compared with chemically synthesized surfactants. The numerous advantages of BSs have prompted applications not only in the food, cosmetic and pharmaceutical industries but also in environmental protection and energy-saving technology. Among BSs, glycolipid types are the most promising, owing to their high productivity from renewable resources and versatile biochemical properties. MELs (mannosylerythritol lipids), which are glycolipid BSs abundantly produced by basidiomycetous yeasts such as strains of Pseudozyma, exhibit not only excellent interfacial properties, but also remarkable differentiation-inducing activities against human leukaemia cells. MELs also show high binding affinity towards different immunoglobulins and lectins. Recently, a cationic liposome bearing MEL has been demonstrated to increase dramatically the efficiency of gene transfection into mammalian cells. These features of BSs should broaden their application in new advanced technologies. In the present review the current status of research and development on glycolipid BSs, especially their production by Pseudozyma yeasts, is described. PMID:19341364

  11. Cholesterol (image)

    Science.gov (United States)

    Cholesterol is a soft, waxy substance that is present in all parts of the body including the ... and obtained from animal products in the diet. Cholesterol is manufactured in the liver and is needed ...

  12. [Advance in glycolipid biosurfactants--mannosylerythritol lipids].

    Science.gov (United States)

    Fan, Linlin; Zhang, Jun; Cai, Jin; Dong, Yachen; Xu, Tengyang; He, Guoqing; Chen, Qihe

    2013-09-01

    Mannosylerythritol lipids (MELs), mainly produced by Ustilago and Pseudozyma, are surface active compounds that belong to the glycolipid class of biosurfactants. MELs have potential application in food, pharmaceutical and cosmetics industries due to their excellent surface activities and other peculiar bioactivities. In recent years, the research field of MELs has regained much attention abroad. However, MELs are rarely studied in China. In this review, the producing microorganisms and production conditions, diverse structures, biochemical properties, structure-function relationship and biosynthetic pathways of MELs are described. Some research problems and prospects are summarized and discussed as well. PMID:24409686

  13. Stimulation of Natural Killer T Cells by Glycolipids

    Directory of Open Access Journals (Sweden)

    Brian L. Anderson

    2013-12-01

    Full Text Available Natural killer T (NKT cells are a subset of T cells that recognize glycolipid antigens presented by the CD1d protein. The initial discovery of immunostimulatory glycolipids from a marine sponge and the T cells that respond to the compounds has led to extensive research by chemists and immunologists to understand how glycolipids are recognized, possible responses by NKT cells, and the structural features of glycolipids necessary for stimulatory activity. The presence of this cell type in humans and most mammals suggests that it plays critical roles in antigen recognition and the interface between innate and adaptive immunity. Both endogenous and exogenous natural antigens for NKT cells have been identified, and it is likely that glycolipid antigens remain to be discovered. Multiple series of structurally varied glycolipids have been synthesized and tested for stimulatory activity. The structural features of glycolipids necessary for NKT cell stimulation are moderately well understood, and designed compounds have proven to be much more potent antigens than their natural counterparts. Nevertheless, control over NKT cell responses by designed glycolipids has not been optimized, and further research will be required to fully reveal the therapeutic potential of this cell type.

  14. Good vs. Bad Cholesterol

    Science.gov (United States)

    ... Pressure Tools & Resources Stroke More Good vs. Bad Cholesterol Updated:Mar 23,2016 Cholesterol can't dissolve ... test . View an animation of cholesterol . LDL (Bad) Cholesterol LDL cholesterol is considered the “bad” cholesterol because ...

  15. Nitrogen and hydrophosphate affects glycolipids composition in microalgae.

    Science.gov (United States)

    Wang, Xin; Shen, Zhouyuan; Miao, Xiaoling

    2016-01-01

    Glycolipids had received increasing attention because of their uses in various industries like cosmetics, pharmaceuticals, food and machinery manufacture. Microalgae were competitive organisms to accumulate metabolic substance. However, using microalgae to produce glycolipid was rare at present. In this study, glycolipid content of Chlorella pyrenoidosa and Synechococcus sp. under different nitrate and hydrophosphate levels were investigated. The highest glycolipid contents of 24.61% for C. pyrenoidosa and 15.37% for Synechococcus sp. were obtained at nitrate absence, which were 17.19% for C. pyrenoidosa and 10.99% for Synechococcus sp. at 0.01 and 0 g L(-1) hydrophosphate, respectively. Glycolipid productivities of two microalgae could reach at more than 10.59 mg L(-1) d(-1). Nitrate absence induced at least 8.5% increase in MGDG, DGDG and SQDG, while hydrophosphate absence resulted in over 21.2% increase in DGDG and over 48.4% increase in SQDG and more than 22.2% decrease in MGDG in two microalgae. Simultaneous nitrate and hydrophosphate limitation could make further improvement of glycolipid accumulation, which was more than 25% for C. pyrenoidosa and 21% for Synechococcus sp. These results suggest that nitrogen and phosphorus limitation or starvation should be an efficient way to improve microalgal glycolipid accumulation. PMID:27440670

  16. Nitrogen and hydrophosphate affects glycolipids composition in microalgae

    Science.gov (United States)

    Wang, Xin; Shen, Zhouyuan; Miao, Xiaoling

    2016-01-01

    Glycolipids had received increasing attention because of their uses in various industries like cosmetics, pharmaceuticals, food and machinery manufacture. Microalgae were competitive organisms to accumulate metabolic substance. However, using microalgae to produce glycolipid was rare at present. In this study, glycolipid content of Chlorella pyrenoidosa and Synechococcus sp. under different nitrate and hydrophosphate levels were investigated. The highest glycolipid contents of 24.61% for C. pyrenoidosa and 15.37% for Synechococcus sp. were obtained at nitrate absence, which were 17.19% for C. pyrenoidosa and 10.99% for Synechococcus sp. at 0.01 and 0 g L−1 hydrophosphate, respectively. Glycolipid productivities of two microalgae could reach at more than 10.59 mg L−1 d−1. Nitrate absence induced at least 8.5% increase in MGDG, DGDG and SQDG, while hydrophosphate absence resulted in over 21.2% increase in DGDG and over 48.4% increase in SQDG and more than 22.2% decrease in MGDG in two microalgae. Simultaneous nitrate and hydrophosphate limitation could make further improvement of glycolipid accumulation, which was more than 25% for C. pyrenoidosa and 21% for Synechococcus sp. These results suggest that nitrogen and phosphorus limitation or starvation should be an efficient way to improve microalgal glycolipid accumulation. PMID:27440670

  17. Glycolipid biosurfactants: Potential related biomedical and biotechnological applications.

    Science.gov (United States)

    Inès, Mnif; Dhouha, Ghribi

    2015-10-30

    Glycolipids, consisting of a carbohydrate moiety linked to fatty acids, are microbial surface active compounds produced by various microorganisms. They are characterized by highly structural diversity and have the ability to decrease the surface and interfacial tension at the surface and interface respectively. Rhamnolipids, trehalolipids, mannosylerythritol-lipids and cellobiose lipids are among the most popular glycolipids. Moreover, their ability to form pores and destabilize biological membrane permits their use in biomedicine as antibacterial, antifungal and hemolytic agents. Their antiviral and antitumor effects enable their use in pharmaceutic as therapeutic agents. Also, glycolipids can inhibit the bioadhesion of pathogenic bacteria enabling their use as anti-adhesive agents and for disruption of biofilm formation and can be used in cosmetic industry. Moreover, they have great potential application in industry as detergents, wetting agents and for flotation. Furthermore, glycolipids can act at the surface and can modulate enzyme activity permitting the enhancement or the inhibition of the activity of certain enzymes. PMID:26359535

  18. Biosynthesis and skin health applications of antimicrobial glycolipids

    Science.gov (United States)

    Microbial-produced glycolipids (MGLs) such as sophorolipids (SLs), rhamnolipids (RLs), and mannosylerythritol lipids (MELs) are amphiphilic molecules, and thus have been widely explored for use as surfactants/detergents, emulsifiers, and lubricants. One major hindrance to their widespread commercia...

  19. Glycolipids from the red alga Chondria armata (Kutz.) Okamura

    Digital Repository Service at National Institute of Oceanography (India)

    Al-Fadhli, A.; Wahidullah, S.; DeSouza, L.

    Three distinct fractions containing polar glycolipids (PF1–3) were isolated from the chloroform soluble fraction of crude methanolic extract of red alga Chondria armata (Kütz.) Okamura on gel chromatography over Sephadex LH20. Their structure...

  20. Cholesterol Test

    Science.gov (United States)

    ... seen when there is an existing problem like malnutrition , liver disease , or cancer . However there is no ... cholesterol levels include anabolic steroids, beta blockers , epinephrine, oral contraceptives, and vitamin D. ^ Back to top ... Health Professionals Get the Mobile App iTunes | Android | Kindle ...

  1. Cholesterol and Your Child

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth Cholesterol and Your Child KidsHealth > For Parents > Cholesterol and ... child's risk of developing heart disease later. About Cholesterol Cholesterol is a waxy substance produced by the ...

  2. Women and Cholesterol

    Science.gov (United States)

    ... Blood Pressure Tools & Resources Stroke More Women and Cholesterol Updated:Apr 1,2016 The female sex hormone ... Glossary Related Sites Nutrition Center My Life Check Cholesterol • Home • About Cholesterol • Why Cholesterol Matters • Understand Your ...

  3. HDL Cholesterol Test

    Science.gov (United States)

    ... limited. Home Visit Global Sites Search Help? HDL Cholesterol Share this page: Was this page helpful? Also ... HDL; HDL-C Formal name: High-density Lipoprotein Cholesterol Related tests: Cholesterol ; LDL Cholesterol ; Triglycerides ; Lipid Profile ; ...

  4. LDL Cholesterol Test

    Science.gov (United States)

    ... limited. Home Visit Global Sites Search Help? LDL Cholesterol Share this page: Was this page helpful? Also ... LDL; LDL-C Formal name: Low-Density Lipoprotein Cholesterol Related tests: Cholesterol ; HDL Cholesterol ; Triglycerides ; Lipid Profile ; ...

  5. Cholesterol IQ Quiz

    Science.gov (United States)

    ... Pressure High Blood Pressure Tools & Resources Stroke More Cholesterol IQ Quiz Updated:Feb 2,2015 Begin the quiz Cholesterol • Home • About Cholesterol Introduction Good vs. Bad Cholesterol ...

  6. Oligosaccharides and glycolipids addition in charged lamellar phases; Addition d`oligosaccharides et de glycolipides dans des phases lamellaires chargees

    Energy Technology Data Exchange (ETDEWEB)

    Ricoul, F

    1997-09-26

    The aim of this work is to study the addition of oligosaccharides and glycolipids in lamellar phases of the cationic surfactant DDAB (di-dodecyl-dimethyl-ammonium bromide). Two steps have been followed: the determination of phases prisms and the thermodynamic interpretation in terms of molecular interactions. In order to characterize these systems, two new experimental small angle scattering methods have been perfected: 1) a neutron scattering contrast variation method which allows to study the adsorption of aqueous solution in bilayers and 2) a capillary concentration gradient method to establish directly and quantitatively the phases diagrams of ternary systems by X rays scattering. It has been pointed out that the oligosaccharides induce a depletion attractive force on the lamellar-lamellar equilibrium of the DDAB when they are excluded of the most concentrated phase. For the two studied glycolipids: 2-O lauroyl-saccharose and N-lauroyl N-nonyl lactitol, the ternary phase diagrams water-DDAB-glycolipid have been established in terms of temperature. Critical points at ambient temperature have been given. The osmotic pressure in concentrated lamellar phases has been measured. It has been shown that glycolipids increase the hydration repulsion at short distance and that the electrostatic repulsion is outstanding and unchanged at high distance if there is at less 1 mole percent of ionic surfactant. In a dilute solution, glycolipids decrease the maximum swelling of lamellar phases, with a competition between the lamellar phase and the micellae dilute phase for water. (O.M.). 165 refs.

  7. Controlled release of diclofenac sodium in glycolipid incorporated micro emulsions.

    Science.gov (United States)

    Premarathne, E P N; Karunaratne, D N; Perera, A D L Chandani

    2016-09-25

    The effect of the glycolipid, hexadecyl-β-d-glucopyranoside, incorporated in microemulsions (ME(1)) towards the enhancement of skin absorption and skin permeation of Diclofenac sodium (DS(2)) was evaluated. A Franz diffusion cell with a piece of pig's ear epidermis indicated that the optimized ME formulation with glycolipid (0.05wt%) exhibited significantly higher permeability than the conventional formulations. The releasing profiles of DS from ME formulations exhibited first order release kinetics resembling a diffusion controlled release model for the first 8h. Incorporating hexadecyl-β-D glucopyranoside in ME formulations shows significant potential as a delivery vehicle in the cosmetics and pharmaceutical industry. PMID:27477103

  8. Isolation and screening of glycolipid biosurfactant producers from sugarcane.

    Science.gov (United States)

    Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Hirose, Naoto; Kitamoto, Dai

    2012-01-01

    Forty-three fungal producers for glycolipid biosurfactants, mannosylerythritol lipids (MELs), were isolated from leaves and smuts of sugarcane plants. These isolates produced MELs with sugarcane juice as nutrient source. The strains were taxonomically categorized into the genera Pseudozyma and Ustilago on the basis of partial sequences of the ribosomal RNA gene. PMID:22972331

  9. Production of microbial glycolipid biosurfactants and their antimicrobial activity

    Science.gov (United States)

    Microbial glycolipids produced by bacteria or yeast as secondary metabolites, such as sophorolipids (SLs), rhamnolipids (RLs) and mannosylerythritol lipids (MELs) are “green” biosurfactants desirable in a bioeconomy. High cost of production is a major hurdle toward widespread commercial use of bios...

  10. Temperature induced changes in the heterocyst glycolipid composition of N

    NARCIS (Netherlands)

    Bauersachs, T.; Stal, L.J.; Grego, M.; Schwark, L.; Schwark, L.

    2014-01-01

    We investigated the effect of temperature on the heterocyst glycolipid (HG) composition of the diazotrophic heterocystous cyanobacteria Anabaena sp. strain CCY9613 and Nostoc sp. strain CCY9926 grown at 9, 12, 16, 20 and 24 degrees C. Both strains contained an overall similar composition of heterocy

  11. What Is Cholesterol?

    Science.gov (United States)

    ... How Can I Help a Friend Who Cuts? Cholesterol KidsHealth > For Teens > Cholesterol Print A A A ... High Cholesterol? en español ¿Qué es el colesterol? Cholesterol Is a Fat in the Blood Cholesterol (kuh- ...

  12. Cholesterol and lifestyle

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000099.htm Cholesterol and lifestyle To use the sharing features on ... Stroke Serious heart or blood vessel disease Your Cholesterol Numbers All men should have their blood cholesterol ...

  13. Cholesterol testing and results

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000386.htm Cholesterol testing and results To use the sharing features ... can tell you what your goal should be. Cholesterol Tests Some cholesterol is considered good and some ...

  14. Cholesterol Facts and Statistics

    Science.gov (United States)

    ... Blood Pressure Salt Million Hearts® WISEWOMAN Program High Cholesterol Facts Recommend on Facebook Tweet Share Compartir As ... the facts about high cholesterol [PDF-281K] . High Cholesterol in the United States 73.5 million adults ( ...

  15. Glycolipids from macroalgae: potential biomolecules for marine biotechnology?

    Directory of Open Access Journals (Sweden)

    Bianca B. Mattos

    2011-04-01

    Full Text Available Brown, red and green algae from the Southeastern coast of Brazil were successively extracted with chloroform/methanol 2:1 and 1:2 (v/v. The crude lipid extract was partitioned according to Folch and the lower phase enriched in glycolipids was fractionated on a silica gel column chromatography eluted with chloroform, acetone and methanol. Three major orcinol-reactive bands present in the acetone and methanol fractions were detected by thin-layer chromatography with chromatographic mobilities corresponding to sulfoglycolipids and glycosyldiacylglycerols. These fractions exhibited potent antiviral activity against HSV-1-ACVs and HSV-1-ACVr and present low toxicity for cell cultures. Purification and identification of these bioactive glycolipids will be necessary in order to elucidate their primary structures and mechanism of action.

  16. Constrained wormholes

    International Nuclear Information System (INIS)

    The large wormhole problem in Coleman's theory of the cosmological constant is presented in the framework of constrained wormholes. We use semi-classical methods, similar to those used to study constrained instantons in quantum field theory. A scalar field theory serves as a toy model to analyze the problems associated with large constrained instantons. In particular, these large instantons are found to suffer from large quantum fluctuations. In gravity we find the same situation: large quantum fluctuations around large wormholes. In both cases we expect that these large fluctuations are a signal that large constrained solutions are not important in the path integral. Thus, we argue that only small wormholes are important in Coleman's theory. (orig.)

  17. Novel phenolic glycolipids: antioxidant activity and effect on membrane models

    OpenAIRE

    Sainvitu, Pauline; Nasir, Mehmet Nail; Draguet, Florian; Nott, Katherine; Lins, Laurence; Crowet, Jean-Marc; Willems, Luc; Cosse, Jean-Philippe; Jérôme, Christine; Deleu, Magali

    2013-01-01

    Aromatic glycolipids are of both medical as well as pharmaceutical interest. Antimicrobial, antiviraland antiinflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic). Moreover, they are expected to have interesting antioxidant properties when they contain phenolic groups. The alkyl chain should enhance their ability to penetrate into the cellular membrane (Nicolosi, 2002, Journal of Molecular Catalysis B: Enzymatic). The presence of a sugar unit co...

  18. Peroxisomes contribute to biosynthesis of extracellular glycolipids in fungi.

    Science.gov (United States)

    Freitag, Johannes; Ast, Julia; Linne, Uwe; Stehlik, Thorsten; Martorana, Domenica; Bölker, Michael; Sandrock, Björn

    2014-07-01

    Many microorganisms secrete surface-active glycolipids. The basidiomycetous fungus Ustilago maydis produces two different classes of glycolipids, mannosylerythritol lipids (MEL) and ustilagic acids (UAs). Here we report that biosynthesis of MELs is partially localized in peroxisomes and coupled to peroxisomal fatty acid degradation. The acyltransferases, Mac1 and Mac2, which acylate mannosylerythritol with fatty acids of different length, contain a type 1 peroxisomal targeting signal (PTS1). We demonstrate that Mac1 and Mac2 are targeted to peroxisomes, while other enzymes involved in MEL production reside in different compartments. Mis-targeting of Mac1 and Mac2 to the cytosol did not block MEL synthesis but promoted production of MEL species with altered acylation pattern. This is in contrast to peroxisome deficient mutants that produced MELs similar to the wild type. We could show that cytosolic targeting of Mac1 and Mac2 reduces the amount of UA presumably due to competition for overlapping substrates. Interestingly, hydroxylated fatty acids characteristic for UAs appear in MELs corroborating cross-talk between both biosynthesis pathways. Therefore, peroxisomal localization of MEL biosynthesis is not only prerequisite for generation of the natural spectrum of MELs, but also facilitates simultaneous assembly of different glycolipids in a single cell. PMID:24835306

  19. Mannosylerythritol lipid, a yeast extracellular glycolipid, shows high binding affinity towards human immunoglobulin G

    OpenAIRE

    Ikegami Toru; Yanagishita Hiroshi; Nakane Takashi; Im Jae Hong; Kitamoto Dai

    2001-01-01

    Abstract Background There have been many attempts to develop new materials with stability and high affinity towards immunoglobulins. Some of glycolipids such as gangliosides exhibit a high affinity toward immunoglobulins. However, it is considerably difficult to develop these glycolipids into the practical separation ligand due to their limited amounts. We thus focused our attention on the feasible use of "mannosylerythritol lipid A", a yeast glycolipid biosurfactant, as an alternative ligand...

  20. A basidiomycetous yeast, Pseudozyma crassa, produces novel diastereomers of conventional mannosylerythritol lipids as glycolipid biosurfactants.

    Science.gov (United States)

    Fukuoka, Tokuma; Kawamura, Mayo; Morita, Tomotake; Imura, Tomohiro; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2008-11-24

    Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by the yeast strains of the genus Pseudozyma. These compounds show not only excellent surface-active properties, but also versatile biochemical actions. During a survey of new MEL producers, we found that a basidiomycetous yeast, Pseudozyma crassa, extracellularly produces three glycolipids. When glucose and oleic acid were used as the carbon source, the total amount of glycolipids reached approximately 4.6g/L in the culture medium. The structures of these glycolipids were similar to those of well-known MEL-A, -B, and -C, respectively. Very interestingly, in all the present glycolipids, the configuration of the erythritol moiety was entirely opposite to that of conventional MELs. The present glycolipids were identified to have the carbohydrate structure of 4-O-beta-D-mannopyranosyl-(2R,3S)-erythritol, stereochemically different from 4-O-beta-D-mannopyranosyl-(2S,3R)-erythritol of conventional MELs. Furthermore, these new glycolipids possessed both short-chain acids (C(2) or C(4)) and long-chain acids (C(14), C(16), or C(18)) on the mannose moiety. The major component of the present glycolipids clearly showed different interfacial and biological properties, compared to conventional MELs comprising two medium-chain acids on the mannose moiety. Accordingly, the novel MEL diastereomers produced by P. crassa should provide us with different glycolipid functions, and facilitate a broad range of applications of MELs. PMID:18805521

  1. Two-enzyme systems for glycolipid and polyglycerolphosphate lipoteichoic acid synthesis in Listeria monocytogenes

    OpenAIRE

    Webb, Alexander J; Karatsa-Dodgson, Maria; Gründling, Angelika

    2009-01-01

    Lipoteichoic acid (LTA) is an important cell wall polymer in Gram-positive bacteria and often consists a polyglycerolphosphate backbone chain that is linked to the membrane by a glycolipid. In Listeria monocytogenes this glycolipid is Gal-Glc-DAG or Gal-Ptd-6Glc-DAG. Using a bioinformatics approach, we have identified L. monocytogenes genes predicted to be involved in glycolipid (lmo2555 and lmo2554) and LTA backbone (lmo0644 and lmo0927) synthesis. LTA and glycolipid analysis of wild-type an...

  2. Reverse cholesterol transport revisited

    Institute of Scientific and Technical Information of China (English)

    Astrid; E; van; der; Velde

    2010-01-01

    Reverse cholesterol transport was originally described as the high-density lipoprotein-mediated cholesterol flux from the periphery via the hepatobiliary tract to the intestinal lumen, leading to fecal excretion. Since the introduction of reverse cholesterol transport in the 1970s, this pathway has been intensively investigated. In this topic highlight, the classical reverse cholesterol transport concepts are discussed and the subject reverse cholesterol transport is revisited.

  3. Constrained Appropriations

    DEFF Research Database (Denmark)

    Wildermuth, Norbert

    2008-01-01

    their practices of meaning making and consumption are realised ‘under conditions which are not of their own choosing', but constrained by the wider relations of economic and political power which shape their lives. Based, primarily, on the results of my qualitative empirical field research in Recife, I will show...

  4. Recognition of microbial glycolipids by Natural Killer T cells

    Directory of Open Access Journals (Sweden)

    Dirk Michael Zajonc

    2015-08-01

    Full Text Available T cells can recognize microbial antigens when presented by dedicated antigen-presenting molecules. While peptides are presented by classical members of the Major Histocompatibility (MHC family (MHC I and II, lipids, glycolipids and lipopeptides can be presented by the non-classical MHC member CD1. The best studied subset of lipid-reactive T cells are Type I Natural killer T (iNKT cells that recognize a variety of different antigens when presented by the non-classical MHCI homolog CD1d. iNKT cells have been shown to be important for the protection against various microbial pathogens, including B. burgdorferi the causative agents of Lyme disease and S. pneumoniae, which causes pneumococcal meningitis and community-acquired pneumonia. Both pathogens carry microbial glycolipids that can trigger the T cell antigen receptor (TCR, leading to iNKT cell activation. iNKT cells have an evolutionary conserved TCR alpha chain, yet retain the ability to recognize structurally diverse glycolipids. They do so using a conserved recognition mode, in which the TCR enforces a conserved binding orientation on CD1d. TCR binding is accompanied by structural changes within the TCR binding site of CD1d, as well as the glycolipid antigen itself. In addition to direct recognition of microbial antigens, iNKT cells can also be activated by a combination of cytokines (IL-12/IL-18 and TCR stimulation. Many microbes carry TLR antigens and microbial infections can lead to TLR activation. The subsequent cytokine response in turn lower the threshold of TCR mediated iNKT cell activation, especially when weak microbial or even self-antigens are presented during the cause of the infection. In summary, iNKT cells can be directly activated through TCR triggering of strong antigens, while cytokines produced by the innate immune response may be necessary for TCR triggering and iNKT cell activation in the presence of weak antigens. Here we will review the molecular basis of iNKT cell

  5. Get Your Cholesterol Checked

    Science.gov (United States)

    ... You also get cholesterol by eating foods like egg yolks, fatty meats, and regular cheese. If you have too much cholesterol in your body, it can build up inside your blood vessels and make it hard for blood to ...

  6. Cholesterol - drug treatment

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000314.htm Cholesterol - drug treatment To use the sharing features on ... treatment; Hardening of the arteries - statin Statins for Cholesterol Statins reduce your risk of heart disease, stroke, ...

  7. Trehalose Polyphleates Are Produced by a Glycolipid Biosynthetic Pathway Conserved across Phylogenetically Distant Mycobacteria.

    Science.gov (United States)

    Burbaud, Sophie; Laval, Françoise; Lemassu, Anne; Daffé, Mamadou; Guilhot, Christophe; Chalut, Christian

    2016-02-18

    Mycobacteria synthesize a variety of structurally related glycolipids with major biological functions. Common themes have emerged for the biosynthesis of these glycolipids, including several families of proteins. Genes encoding these proteins are usually clustered on bacterial chromosomal islets dedicated to the synthesis of one glycolipid family. Here, we investigated the function of a cluster of five genes widely distributed across non-tuberculous mycobacteria. Using defined mutant analysis and in-depth structural characterization of glycolipids from wild-type or mutant strains of Mycobacterium smegmatis and Mycobacterium abscessus, we established that they are involved in the formation of trehalose polyphleates (TPP), a family of compounds originally described in Mycobacterium phlei. Comparative genomics and lipid analysis of strains distributed along the mycobacterial phylogenetic tree revealed that TPP is synthesized by a large number of non-tuberculous mycobacteria. This work unravels a novel glycolipid biosynthetic pathway in mycobacteria and extends the spectrum of bacteria that produce TPP. PMID:27028886

  8. Common Misconceptions about Cholesterol

    Science.gov (United States)

    ... your doctor recommends. Learn more about eating a healthy diet. Thin people don't have to worry about high cholesterol. A person with any body type can have high cholesterol. Overweight people are more likely to have ... heart-healthy. Have your cholesterol checked regularly regardless of your ...

  9. Thiolactosides: Scaffolds for the Synthesis of Glycolipids in Animal Cells

    Directory of Open Access Journals (Sweden)

    Masako Mori

    2011-01-01

    Full Text Available Various glycolipids were synthesized using thiolactosides as scaffolds for glycosylation in animal cells. The basic building blocks, n-dodecyl β-D-thiolactoside (β-LacSC12 and n-dodecyl α-D-thiolactoside (α-LacSC12, were chemically synthesized in 2 steps: glycosylation followed by deacylation. The thiolactosides were administered to animal cells in culture and served as substrates for cellular enzyme-catalyzed glycosylation. Incubation of mouse melanoma B16 cells in the presence of β-LacSC12 or α-LacSC12 resulted in sialylation of the terminal galactose residue and gave a GM3-type ganglioside. Administration of β-Lac SC12 in Madin-Darby canine kidney (MDCK cells likewise gave a GM3-type ganglioside. On the other hand, introduction of β-LacSC12 in African green monkey kidney (Vero cells gave Gb3- and Gb4-type glycolipids aside from GM3-type ganglioside. In the course of the study, significant changes in B16 cell morphology and elevated secretion of melanin were also observed.

  10. Home-Use Tests - Cholesterol

    Science.gov (United States)

    ... Medical Procedures In Vitro Diagnostics Home Use Tests Cholesterol Share Tweet Linkedin Pin it More sharing options ... a home-use test kit to measure total cholesterol. What cholesterol is: Cholesterol is a fat (lipid) ...

  11. Tangled evolutionary processes with commonality and diversity in plastidial glycolipid synthesis in photosynthetic organisms.

    Science.gov (United States)

    Hori, Koichi; Nobusawa, Takashi; Watanabe, Tei; Madoka, Yuka; Suzuki, Hideyuki; Shibata, Daisuke; Shimojima, Mie; Ohta, Hiroyuki

    2016-09-01

    In photosynthetic organisms, the photosynthetic membrane constitutes a scaffold for light-harvesting complexes and photosynthetic reaction centers. Three kinds of glycolipids, namely monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol, constitute approximately 80-90% of photosynthetic membrane lipids and are well conserved from tiny cyanobacteria to the leaves of huge trees. These glycolipids perform a wide variety of functions beyond biological membrane formation. In particular, the capability of adaptation to harsh environments through regulation of membrane glycolipid composition is essential for healthy growth and development of photosynthetic organisms. The genome analysis and functional genetics of the model seed plant Arabidopsis thaliana have yielded many new findings concerning the biosynthesis, regulation, and functions of glycolipids. Nevertheless, it remains to be clarified how the complex biosynthetic pathways and well-organized functions of glycolipids evolved in early and primitive photosynthetic organisms, such as cyanobacteria, to yield modern photosynthetic organisms like land plants. Recently, genome data for many photosynthetic organisms have been made available as the fruit of the rapid development of sequencing technology. We also have reported the draft genome sequence of the charophyte alga Klebsormidium flaccidum, which is an intermediate organism between green algae and land plants. Here, we performed a comprehensive phylogenic analysis of glycolipid biosynthesis genes in oxygenic photosynthetic organisms including K. flaccidum. Based on the results together with membrane lipid analysis of this alga, we discuss the evolution of glycolipid synthesis in photosynthetic organisms. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. PMID:27108062

  12. Glycolipid biosurfactants: main properties and potential applications in agriculture and food industry.

    Science.gov (United States)

    Mnif, Inès; Ghribi, Dhouha

    2016-10-01

    Glycolipids, consisting of a carbohydrate moiety linked to fatty acids, are microbial surface active compounds produced by various microorganisms. They are characterized by high structural diversity and have the ability to decrease the surface and interfacial tension at the surface and interface, respectively. Rhamnolipids, trehalolipids, mannosylerythritol lipids and cellobiose lipids are among the most popular glycolipids. They have received much practical attention as biopesticides for controlling plant diseases and protecting stored products. As a result of their antifungal activity towards phytopathogenic fungi and larvicidal and mosquitocidal potencies, glycolipid biosurfactants permit the preservation of plants and plant crops from pest invasion. Also, as a result of their emulsifying and antibacterial activities, glycolipids have great potential as food additives and food preservatives. Furthermore, the valorization of food byproducts via the production of glycolipid biosurfactant has received much attention because it permits the bioconversion of byproducts on valuable compounds and decreases the cost of production. Generally, the use of glycolipids in many fields requires their retention from fermentation media. Accordingly, different strategies have been developed to extract and purify glycolipids. © 2016 Society of Chemical Industry. PMID:27098847

  13. The molecular components of phospho- and glycolipid metabolism in plant cell membranes under the phosphorus deficiency

    Directory of Open Access Journals (Sweden)

    Svietlova N. B.

    2012-01-01

    Full Text Available One of the aspects of molecular regulation of phosphorus metabolism in plants, the lipid components of membrane structures, has been reviewed. The refocusing of phosphoand glycolipid metabolism is an indicator of phosphorus accessibility in plants. The compensatory mechanisms of substitution of phospholipids with non-phosphorus containing glycolipids in membranes, allow plants to adapt to the phosphate (Pi starvation. Phospholipids are the reserve pool of cellular phosphorus at reutilization of ions in the donor-acceptor system of plants. The mechanisms of transcriptional regulation of genes involved in the synthesis of phospholipids and glycolipids under Pi deficit have been analyzed.

  14. Properties of glycolipid-enriched membrane rafts in antigen presentation.

    Science.gov (United States)

    Rodgers, William; Smith, Kenneth

    2005-01-01

    Presentation of antigen to T cells represents one of the central events in the engagement of the immune system toward the defense of the host against pathogens. Accordingly, understanding the mechanisms by which antigen presentation occurs is critical toward our understanding the properties of host defense against foreign antigen, as well as insight into other features of the immune system, such as autoimmune disease. The entire antigen-presentation event is complex, and many features of it remain poorly understood. However, recent studies have provided evidence showing that glycolipid-enriched membrane rafts are important for efficient antigen presentation; the studies suggest that one such function of rafts is trafficking of antigen-MHC II complexes to the presentation site on the surface of the antigen-presenting cell. Here, we present a critical discussion of rafts and their proposed functions in antigen presentation. Emerging topics of rafts and antigen presentation that warrant further investigation are also highlighted.

  15. Ethanolamine-phosphate modified glycolipids in Clostridium acetobutylicum that respond to membrane stress

    OpenAIRE

    Tian, Bing; Guan, Ziqiang; Goldfine, Howard

    2013-01-01

    Two phosphorus-containing glycolipids have previously been observed in Clostridium acetobutylicum. We had shown that the concentration of one of them increases in response to increased unsaturation of the membrane lipid hydrocarbon chains, suggesting a potential role in the regulation of lipid polymorphism in this organism. Mass spectrometry shows that these glycolipids are ethanolamine phosphate (Etn-P)-containing derivatives of a mono- and diglycosyldiradylglycerol. The content of both digl...

  16. In Vitro Biosynthesis of Ether-Type Glycolipids in the Methanoarchaeon Methanothermobacter thermautotrophicus▿

    OpenAIRE

    Morii, Hiroyuki; Eguchi, Tadashi; Koga, Yosuke

    2007-01-01

    The biosynthesis of archaeal ether-type glycolipids was investigated in vitro using Methanothermobacter thermautotrophicus cell-free homogenates. The sole sugar moiety of glycolipids and phosphoglycolipids of the organism is the β-d-glucosyl-(1→6)-d-glucosyl (gentiobiosyl) unit. The enzyme activities of archaeol:UDP-glucose β-glucosyltransferase (monoglucosylarchaeol [MGA] synthase) and MGA:UDP-glucose β-1,6-glucosyltransferase (diglucosylarchaeol [DGA] synthase) were found in the methanoarch...

  17. Glycolipid Transfer Protein Interaction with Bilayer Vesicles: Modulation by Changing Lipid Composition

    OpenAIRE

    Rao, Chetan S; Chung, Taeowan; Pike, Helen M.; Brown, Rhoderick E.

    2005-01-01

    Glycosphingolipids (GSLs) are important constituents of lipid rafts and caveolae, are essential for the normal development of cells, and are adhesion sites for various infectious agents. One strategy for modulating GSL composition in lipid rafts is to selectively transfer GSL to or from these putative membrane microdomains. Glycolipid transfer protein (GLTP) catalyzes selective intermembrane transfer of GSLs. To enable effective use of GLTP as a tool to modify the glycolipid content of membra...

  18. Stimulation of adult neural stem cells with a novel glycolipid biosurfactant

    OpenAIRE

    Stipcevic, Tamara; Knight, Christopher P.; Kippin, Tod E.

    2013-01-01

    Glycolipids are amphipatic molecules which are highly expressed on cell membranes in skin and brain where they mediate several key cellular processes. Neural stem cells are defined as undifferentiated, proliferative, multipotential cells with extensive self-renewal and are responsive to brain injury. Di-rhamnolipid: α-L-rhamnopyranosyl-(1-2)α-L-rhamnopyranosyl-3-hydroxydecanoyl-3-hydroxydecanoic acid, also referred to as di-rhamnolipid BAC-3, is a glycolipid isolated from bacteria Pseudomonas...

  19. National Cholesterol Education Month

    Centers for Disease Control (CDC) Podcasts

    2009-09-01

    Do you know your cholesterol numbers? Your doctor can do a simple test to check your cholesterol levels and help you make choices that lower your risk for heart disease and stroke.  Created: 9/1/2009 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 9/9/2009.

  20. Glycosylation of Glycolipids in Cancer: Basis for Development of Novel Therapeutic Approaches

    Directory of Open Access Journals (Sweden)

    Jose Luis Daniotti

    2013-12-01

    Full Text Available Altered networks of gene regulation underlie many pathologies, including cancer. There are several proteins in cancer cells that are turned either on or off, which dramatically alters the metabolism and the overall activity of the cell, with the complex machinery of enzymes involved in the metabolism of glycolipids not being an exception. The aberrant glycosylation of glycolipids on the surface of the majority of cancer cells, associated with increasing evidence about the functional role of these molecules in a number of cellular physiological pathways, has received considerable attention as a convenient immunotherapeutic target for cancer treatment. This has resulted in the development of a substantial number of passive and active immunotherapies, which have shown promising results in clinical trials. More recently, antibodies to glycolipids have also emerged as an attractive tool for the targeted delivery of cytotoxic agents, thereby providing a rationale for future therapeutic interventions in cancer. This review first summarizes the cellular and molecular bases involved in the metabolic pathway and expression of glycolipids, both in normal and tumor cells, paying particular attention to sialosylated glycolipids (gangliosides. The current strategies in the battle against cancer in which glycolipids are key players are then described.

  1. Bile acid sequestrants for cholesterol

    Science.gov (United States)

    ... ency/patientinstructions/000787.htm Bile acid sequestrants for cholesterol To use the sharing features on this page, ... are medicines that help lower your LDL (bad) cholesterol . Too much cholesterol in your blood can stick ...

  2. What Causes High Blood Cholesterol?

    Science.gov (United States)

    ... the NHLBI on Twitter. What Causes High Blood Cholesterol? Many factors can affect the cholesterol levels in your blood. You can control some ... but not others. Factors You Can Control Diet Cholesterol is found in foods that come from animal ...

  3. Hopanoids as functional analogues of cholesterol in bacterial membranes.

    Science.gov (United States)

    Sáenz, James P; Grosser, Daniel; Bradley, Alexander S; Lagny, Thibaut J; Lavrynenko, Oksana; Broda, Martyna; Simons, Kai

    2015-09-22

    The functionality of cellular membranes relies on the molecular order imparted by lipids. In eukaryotes, sterols such as cholesterol modulate membrane order, yet they are not typically found in prokaryotes. The structurally similar bacterial hopanoids exhibit similar ordering properties as sterols in vitro, but their exact physiological role in living bacteria is relatively uncharted. We present evidence that hopanoids interact with glycolipids in bacterial outer membranes to form a highly ordered bilayer in a manner analogous to the interaction of sterols with sphingolipids in eukaryotic plasma membranes. Furthermore, multidrug transport is impaired in a hopanoid-deficient mutant of the gram-negative Methylobacterium extorquens, which introduces a link between membrane order and an energy-dependent, membrane-associated function in prokaryotes. Thus, we reveal a convergence in the architecture of bacterial and eukaryotic membranes and implicate the biosynthetic pathways of hopanoids and other order-modulating lipids as potential targets to fight pathogenic multidrug resistance.

  4. Lifestyle Changes and Cholesterol

    Science.gov (United States)

    ... Pressure High Blood Pressure Tools & Resources Stroke More Lifestyle Changes and Cholesterol Updated:Oct 26,2015 As ... disease and stroke, your doctor may suggest some lifestyle changes. Regardless of whether your plan includes drug ...

  5. Cholesterol in unusual places

    Energy Technology Data Exchange (ETDEWEB)

    Kucerka, N; Nieh, M P; Marquardt, D; Harroun, T A; Wassail, S R; Katsaras, J, E-mail: John.Katsaras@nrc.gc.ca, E-mail: Norbert.Kucerka@nrc.gc.ca

    2010-11-01

    Cholesterol is an essential component of mammalian cells, and is required for building and maintaining cell membranes, regulating their fluidity, and possibly acting as an antioxidant. Cholesterol has also been implicated in cell signaling processes, where it has been suggested that it triggers the formation of lipid rafts in the plasma membrane. Aside from cholesterol's physiological roles, what is also becoming clear is its poor affinity for lipids with unsaturated fatty acids as opposed to saturated lipids, such as sphingomyelin with which it forms rafts. We previously reported the location of cholesterol in membranes with varying degrees of acyl chain unsaturation as determined by neutron diffraction studies (Harroun et al 2006 Biochemistry 45, 1227; Harroun et al 2008 Biochemistry 47, 7090). In bilayers composed of phosphatidylcholine (PC) molecules with a saturated acyl chain at the sn-1 position or a monounsaturated acyl chain at both sn-1 and sn-2 positions, cholesterol was found in its much-accepted 'upright' position. However, in dipolyunsaturated 1,2-diarachidonyl phosphatidylcholine (20:4-20:4PC) membranes the molecule was found sequestered in the center of the bilayers. In further experiments, mixing l-palmitoyl-2-oleoyl phosphatidylcholine (16:0-18:1 PC) with 20:4-20:4PC resulted in cholesterol reverting to its upright orientation at approximately 40 mol% 16:0-18:1 PC. Interestingly, the same effect was achieved with only 5 mol% 1,2-dimyristoyl phosphatidylchoile (14:0-14:0PC).

  6. Characterization of new glycolipid biosurfactants, tri-acylated mannosylerythritol lipids, produced by Pseudozyma yeasts.

    Science.gov (United States)

    Fukuoka, Tokuma; Morita, Tomotake; Konishi, Masaaki; Imura, Tomohiro; Kitamoto, Dai

    2007-07-01

    Mannosylerythritol lipids (MELs) are glycolipid biosurfactants produced by Pseudozyma yeasts. They show not only the excellent interfacial properties but also versatile biochemical actions. In the course of MEL production from soybean oil by P. antarctica and P. rugulosa, some new extracellular glycolipids (more hydrophobic than the previously reported di-acylated MELs) were found in the culture medium. The most hydrophobic one was identified as 1-O-alka(e)noyl-4-O-[(4',6'-di-O-acetyl-2',3'-di-O-alka(e)noyl)-beta-D-mannopyranosyl]-D-erythritol, namely tri-acylated MEL. Others were tri-acylated MELs bearing only one acetyl group. The tri-acylated MEL could be prepared by the lipase-catalyzed esterification of a di-acylated MEL with oleic acid implying that the new glycolipids are synthesized from di-acylated MELs in the culture medium containing the residual fatty acids. PMID:17417694

  7. Pachymoside A - a novel glycolipid isolated from the marine sponge Pachymatisma johnstonia

    Energy Technology Data Exchange (ETDEWEB)

    Warabi, K.; Zimmerman, W.T.; Shen, J. [Univ. of British Columbia, Departments of Chemistry, Earth and Ocean Sciences, Vancouver, British Columbia (Canada); Gauthier, A.; Robertson, M.; Finlay, B.B. [Univ. of British Columbia, Departments of Biochemistry and Microbiology, Vancouver, British Columbia (Canada); Van Soest, R. [Univ. of Amsterdam, Dept. of Coelenterates and Porifera, Zoologisch Museum, Amsterdam (Netherlands); Andersen, R.J. [Univ. of British Columbia, Departments of Chemistry, Earth and Ocean Sciences, Vancouver, British Columbia (Canada)]. E-mail: randersn@interchange.ubc.ca

    2004-02-01

    Crude extracts of the North Sea marine sponge Pachymatisma johnstonia showed promising activity in a new assay for inhibitors of bacterial type III secretion. Bioassay-guided fractionation resulted in the isolation of the pachymosides, a new family of sponge glycolipids. A major part of the structural diversity in this family of glycolipids involves increasing degrees of acetylation and differing positions of acetylation on a common pachymoside glycolipid template. All of the metabolites with these variations in acetylation pattern were converted into the same peracetyl-pachymoside methyl ester (2) for purification and spectroscopic analysis. Pachymoside A (1) is the component of the mixture that has natural acetylation at the eight galactose hydroxyls and at the C-6 hydroxyls of glucose-B and glucose-D. Chemical degradation and transformation in conjunction with extensive analysis of 800 MHz NMR data was used to elucidate the structure of pachymoside A (1). (author)

  8. Production of a novel glycolipid biosurfactant, mannosylmannitol lipid, by Pseudozyma parantarctica and its interfacial properties.

    Science.gov (United States)

    Morita, Tomotake; Fukuoka, Tokuma; Konishi, Masaaki; Imura, Tomohiro; Yamamoto, Shuhei; Kitagawa, Masaru; Sogabe, Atsushi; Kitamoto, Dai

    2009-07-01

    The development of a novel glycolipid biosurfactant was undertaken using the high-level producers of mannosylerythritol lipids (MELs) such as Pseudozyma parantarctica, Pseudozyma antarctica, and Pseudozyma rugulosa. Besides the conventional MELs (MEL-A, MEL-B, and MEL-C), these yeasts produced an unknown glycolipid when they were cultivated in a medium containing 4% (w/v) olive oil and 4% (w/w) mannitol as the carbon source. The unknown glycolipid extracted from the culture medium of P. parantarctica JCM 11752(T) displayed the spot with lower mobility than that of known MELs on TLC and provided mainly two peaks identical to mannose and mannitol on high-performance liquid chromatography after acid hydrolysis. Based on structural analysis by (1)H and (13)C nuclear magnetic resonance, the novel glycolipid was composed of mannose and mannitol as the hydrophilic sugar moiety and was identified as mannosylmannitol lipid (MML). Of the strains tested, P. parantarctica JCM 11752(T) gave the best yield of MML (18.2 g/L), which comprised approximately 35% of all glycolipids produced. We further investigated the interfacial properties of the MML, considering the unique hydrophilic structure. The observed critical micelle concentration (CMC) and the surface tension at CMC of the MML were 2.6 x 10(-6) M and 24.2 mN/m, respectively. In addition, on a water-penetration scan, the MML efficiently formed not only the lamella phase (Lalpha) but also the myelins at a wide range of concentrations, indicating its excellent self-assembling properties and high hydrophilicity. The present glycolipid should thus facilitate the application of biosurfactants as new functional materials. PMID:19296097

  9. The neurite-initiating effect of microbial extracellular glycolipids in PC12 cells

    OpenAIRE

    Isoda, Hiroko; Shinmoto, Hiroshi; Matsumura, Masatoshi; Nakahara, Tadaatsu

    1999-01-01

    The effects of several kinds of microbial extracellular glycolipids on neurite initiation in PC12 cells were examined. Addition of mannosylerythritol lipid-A (MEL-A), MEL-B, and sophorose lipid (SL) to PC12 cells caused significant neurite outgrowth. Other glycolipids, such as polyol lipid (PL), rhamnose lipid (RL), succinoyl trehalose lipid-A (STL-A) and STL-B caused no neurite-initiation. MEL-A increased acetylcholine esterase (AChE) activity to an extent similar to nerve growth factor (NGF...

  10. Binding Sites for Acylated Trehalose Analogs of Glycolipid Ligands on an Extended Carbohydrate Recognition Domain of the Macrophage Receptor Mincle*

    Science.gov (United States)

    Feinberg, Hadar; Rambaruth, Neela D. S.; Jégouzo, Sabine A. F.; Jacobsen, Kristian M.; Djurhuus, Rasmus; Poulsen, Thomas B.; Weis, William I.; Taylor, Maureen E.; Drickamer, Kurt

    2016-01-01

    The macrophage receptor mincle binds to trehalose dimycolate on the surface of Mycobacterium tuberculosis. Signaling initiated by this interaction leads to cytokine production, which underlies the ability of mycobacteria to evade the immune system and also to function as adjuvants. In previous work the mechanism for binding of the sugar headgroup of trehalose dimycolate to mincle has been elucidated, but the basis for enhanced binding to glycolipid ligands, in which hydrophobic substituents are attached to the 6-hydroxyl groups, has been the subject of speculation. In the work reported here, the interaction of trehalose derivatives with bovine mincle has been probed with a series of synthetic mimics of trehalose dimycolate in binding assays, in structural studies by x-ray crystallography, and by site-directed mutagenesis. Binding studies reveal that, rather than reflecting specific structural preference, the apparent affinity of mincle for ligands with hydrophobic substituents correlates with their overall size. Structural and mutagenesis analysis provides evidence for interaction of the hydrophobic substituents with multiple different portions of the surface of mincle and confirms the presence of three Ca2+-binding sites. The structure of an extended portion of the extracellular domain of mincle, beyond the minimal C-type carbohydrate recognition domain, also constrains the way the binding domains may interact on the surface of macrophages. PMID:27542410

  11. Functional role of a glycolipid in directional movements of neurons

    Directory of Open Access Journals (Sweden)

    ROSALIA MENDEZ-OTERO

    2001-06-01

    Full Text Available Migration of neurons from their site of origin to their final destination is a critical and universal step in the formation of the complex structure of the nervous system. The migratory process is thought to be governed in part by genetically and epigenetically defined sequences of signals which are interpreted by migrating cells. The molecular mechanisms that underlie neuronal migration have been the subject of intense investigation. As in other developmental processes, many molecules must participate in neuronal migration. Some molecules, such as cell adhesion molecules and motor proteins, may contribute to discrete steps in the migration act; others, like extracellular signaling molecules, may regulate the activation and/or termination of the migration program. In this article we review findings from our group that demonstrate the functional role(s of a specific glycolipid in neuronal migration and neurite outgrowth in the developing and adult nervous system.A migração de neurônios de seus sítios de origem a seus destinos finais é uma etapa universal e crítica na formação da complexa estrutura do sistema nervoso. Admite-se que o processo migratório seja governado, em parte, por sequências de sinais definidas genetica e epigeneticamente que são interpretadas pelas células migrantes. Os mecanismos moleculares subjacentes à migração neuronal têm sido objeto de intensa investigação. Como em outros processos do desenvolvimento, muitas moléculas devem participar na migração neuronal. Algumas delas, como as moléculas de adesão e proteínas motoras, podem contribuir para etapas discretas no ato de migração; outras, como moléculas extra-celulares de sinalização, podem regular a ativação e/ou o término do programa de migração. Neste artigo nós revisamos achados de nosso grupo que demonstram o(s papel (papéis funcional(ais de um glicolipídeo específico na migração neuronal e no crescimento de neuritos no sistema

  12. CHOLESTEROL AND CHOLESTEROL ESTER CONTENT OF BOVINE COLOSTRUM

    Science.gov (United States)

    Shope, Richard E.; Gowen, John W.

    1928-01-01

    The total amount of cholesterol found in colostrum and milk is comparatively low. The amount of cholesterol found in colostrum declines at an ever decreasing rate as milk secretion develops until at 48 hours the cholesterol is nearly the same as that found in milk 3 months or 7 months after parturition. The morning milk differs from the evening milk in that the cholesterol bound as ester is greater in amount. PMID:19869468

  13. Transintestinal cholesterol efflux

    NARCIS (Netherlands)

    van der Velde, Astrid E.; Brufau, Gemma; Groen, Albert K.

    2010-01-01

    Purpose of review Regulation of cholesterol homeostasis is a complex interplay of a multitude of metabolic pathways situated in different organs. The liver plays a central role and has received most attention of the research community. In this review, we discuss recent progress in the understanding

  14. Regulation of cholesterol homeostasis

    NARCIS (Netherlands)

    van der Wulp, Mariette Y. M.; Verkade, Henkjan J.; Groen, Albert K.

    2013-01-01

    Hypercholesterolemia is an important risk factor for cardiovascular disease. It is caused by a disturbed balance between cholesterol secretion into the blood versus uptake. The pathways involved are regulated via a complex interplay of enzymes, transport proteins, transcription factors and non-codin

  15. Cholesterol transport in model membranes

    Science.gov (United States)

    Garg, Sumit; Porcar, Lionel; Butler, Paul; Perez-Salas, Ursula

    2010-03-01

    Physiological processes distribute cholesterol unevenly within the cell. The levels of cholesterol are maintained by intracellular transport and a disruption in the cell's ability to keep these normal levels will lead to disease. Exchange rates of cholesterol are generally studied in model systems using labeled lipid vesicles. Initially donor vesicles have all the cholesterol and acceptor vesicles are devoid of it. They are mixed and after some time the vesicles are separated and cholesterol is traced in each vesicle. The studies performed up to date have significant scatter indicating that the methodologies are not consistent. The present work shows in-situ Time-Resolved SANS studies of cholesterol exchange rates in unsaturated PC lipid vesicles. Molecular dynamics simulations were done to investigate the energetic and kinetic behavior of cholesterol in this system. This synergistic approach will provide insight into our efforts to understand cholesterol traffic.

  16. What Your Cholesterol Levels Mean

    Science.gov (United States)

    ... Blood Pressure Tools & Resources Stroke More What Your Cholesterol Levels Mean Updated:Aug 9,2016 How’s your ... the Terms and Conditions and Privacy Policy Interactive Cholesterol Guide Find videos, trackers and more with our ...

  17. Influence of Working Stress on Glycolipid Metabolism of Military Pilots%飞行人员工作应激对糖脂代谢的影响

    Institute of Scientific and Technical Information of China (English)

    翁庐英; 赵璧; 吴思英

    2012-01-01

    Objective To investigate the status of military pilots' working stress and its influence on glycolipid metabolism,so as to provide theoretical evidence for psychological and physical health of military pilots. Methods By convenience sampling,500 military pilots in Shanghai and Hangzhou were surveyed on their working stress. Simultaneously,the physiological and biochemical indicators (cholesterol,triglycer-ides,high density lipoprotein,and glycated hemoglobin) were measured. The influence of working stress of military pilots' on the glycolipid metabolism were analyzed accordingly. Results For the military pilots,the total score of working stress and the scores of physical condition stress and working interest were higher than those of the national norm(P0. 05). After the adjustment for age factors,the levels of triglyceride,high-density lipoprotein and systolic and diastolic pressures were significantly higher in the high working stress group than in the normal working stress group(P0.05).在调整了年龄因素后,高工作应激组的三酰甘油水平、高密度脂蛋白水平、收缩压和舒张压水平均高于正常工作应激组(P<0.05或P<0.01).结论 工作应激是飞行人员糖脂代谢异常的危险因素,应做好相关的预防及保健工作,以提高飞行人员群体的身心健康水平.

  18. Novel intact glycolipids in sediments from an Antarctic lake (Ace Lake)

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Dongen, B.E. van; Reiss-Schaeffer, C.; Schouten, S.; Volkman, J.K.; Geenevasen, J.A.J.

    2001-01-01

    Two novel glycolipids, docosanyl 3-O-methyl--rhamnopyranoside and docosanyl 3-O-methylxylopyranoside, were identified as the most abundant GC-amenable components of extracts of sediments of Ace Lake, an Antarctic meromictic lake. Docosanyl 3-O-methyl--rhamnopyranoside was identified by isolation and

  19. Long chain glycolipids with pentose head groups as biomarkers for marine endosymbiotic heterocystous cyanobacteria

    NARCIS (Netherlands)

    Bale, N.; Hopmans, E.C.; Zell, C.; Sobrinho, R.; Kim, J.H.; Sinninghe Damsté, J.S.; Villareal, T.A.; Schouten, S.

    2015-01-01

    Marine endosymbiotic heterocystous cyanobacteria make unique heterocyst glycolipids (HGs) containing pentose (C5) moieties. Functionally similar HGs with hexose (C6) moieties found in free-living cyanobacteria occur in the sedimentary record, but C5 HGs have not been documented in the natural enviro

  20. Endosymbiotic heterocystous cyanobacteria synthesize different heterocyst glycolipids than free-living heterocystous cyanobacteria

    NARCIS (Netherlands)

    Schouten, S.; Villareal, T.A.; Hopmans, E.C.; Mets, A.; Swanson, K.M.; Sinninghe Damsté, J.S.

    2013-01-01

    The heterocysts of limnetic nitrogen-fixing filamentous cyanobacteria contain unique glycolipids in their cell wall that create the distinctive gas impermeability of the heterocyst cell wall as well as serve as biomarker lipids for these microbes. It has been assumed that marine free-living and endo

  1. Antifungal Activity of Flocculosin, a Novel Glycolipid Isolated from Pseudozyma flocculosa

    OpenAIRE

    Mimee, Benjamin; Labbé, Caroline; Pelletier, René; Bélanger, Richard R.

    2005-01-01

    Flocculosin, a glycolipid isolated from the yeast-like fungus Pseudozyma flocculosa, was investigated for in vitro antifungal activity. The compound displayed antifungal properties against several pathogenic yeasts. Synergistic activity was observed between flocculosin and amphotericin B, and no significant cytotoxicity was demonstrated when tested against human cell lines.

  2. Reactivity-based One-pot Synthesis of Immunosuppressive Glycolipids from the Caribbean Sponge Plakortis simplex

    Institute of Scientific and Technical Information of China (English)

    L(U), Guokai; WANG, Peng; LIU, Qingchao; ZHANG, Zaihong; ZHANG, Wei; LI, Yingxia

    2009-01-01

    The first synthesis of three natural glycolipid simplexides 1a-1c, which were isolated from the marine sponge Plakortis simplex and claimed to inhibit T cell proliferation, has been concisely accomplished by a reactivity-based one-pot synthetic strategy under the use of p-toluenethioglycoside (STol) donors.

  3. Temperature induced changes in the heterocyst glycolipid composition of N2-fixing heterocystous cyanobacteria

    NARCIS (Netherlands)

    T. Bauersachs; L.J. Stal; M. Grego; L. Schwark

    2014-01-01

    We investigated the effect of temperature on the heterocyst glycolipid (HG) composition of the diazotrophic heterocystous cyanobacteria Anabaena sp. strain CCY9613 and Nostoc sp. strain CCY9926 grown at 9, 12, 16, 20 and 24 °C. Both strains contained an overall similar composition of heterocyst glyc

  4. Self-glycolipids modulate dendritic cells changing the cytokine profiles of committed autoreactive T cells.

    Directory of Open Access Journals (Sweden)

    Karsten Buschard

    Full Text Available The impact of glycolipids of non-mammalian origin on autoimmune inflammation has become widely recognized. Here we report that the naturally occurring mammalian glycolipids, sulfatide and β-GalCer, affect the differentiation and the quality of antigen presentation by monocyte-derived dendritic cells (DCs. In response to sulfatide and β-GalCer, monocytes develop into immature DCs with higher expression of HLA-DR and CD86 but lower expression of CD80, CD40 and CD1a and lower production of IL-12 compared to non-modulated DCs. Self-glycolipid-modulated DCs responded to lipopolysaccharide (LPS by changing phenotype but preserved low IL-12 production. Sulfatide, in particular, reduced the capacity of DCs to stimulate autoreactive Glutamic Acid Decarboxylase (GAD65 - specific T cell response and promoted IL-10 production by the GAD65-specific clone. Since sulfatide and β-GalCer induced toll-like receptor (TLR-mediated signaling, we hypothesize that self-glycolipids deliver a (tolerogenic polarizing signal to differentiating DCs, facilitating the maintenance of self-tolerance under proinflammatory conditions.

  5. Novel Polyoxyethylene-Containing Glycolipids Are Synthesized in Corynebacterium matruchotii and Mycobacterium smegmatis Cultured in the Presence of Tween 80

    Directory of Open Access Journals (Sweden)

    Cindy Wang

    2011-01-01

    Full Text Available The addition of polyoxyethylene sorbitan monooleate (Tween 80 to a culture of mycobacteria greatly influences cell permeability and sensitivity to antibiotics but very little is known regarding the underlying mechanism. Here we show that Corynebacterium matruchotii (surrogate of mycobacteria converts Tween 80 to a structural series of polyoxyethylenic acids which are then used to form novel series-2A and series-2B glycolipids. Minor series-3 glycolipids were also synthesized. The polyoxyethylenic acids replaced corynomycolic acids in the cell wall. Correspondingly the trehalose dicorynomycolate content was reduced. MALDI mass spectrometry, MS-MS, 1H-NMR, and 13C-NMR were used to characterize the series-2 glycolipids. Series-2A glycolipid is trehalose 6-C36:2-corynomycolate-6′-polyoxyethylenate and series-2B glycolipid is trehalose 6-C36:2-corynomycolate-6′-furan ring-containing polyoxyethylenate. Mycobacterium smegmatis grown in the presence of Tween 80 also synthesizes series-2 type glycolipids. The synthesis of these novel glycolipids in corynebacteria and mycobacteria should result in gross changes in the cell wall permeability and drug sensitivity.

  6. Effects of dietary cholesterol on cholesterol and bile acid homeostasis in patients with cholesterol gallstones.

    OpenAIRE

    Kern, F

    1994-01-01

    We examined changes in cholesterol and bile acid metabolism produced by dietary cholesterol in gallstone subjects and matched controls. Healthy women were recruited and, after confirming the presence or absence of radiolucent gallstones, they were studied on regular diets and again on the same diet supplemented with five eggs daily for 15-18 d. Studies included plasma lipids, lipoproteins and apolipoproteins, dietary records, cholesterol absorption, cholesterol synthesis, plasma clearance of ...

  7. Formation of the two novel glycolipid biosurfactants, mannosylribitol lipid and mannosylarabitol lipid, by Pseudozyma parantarctica JCM 11752T.

    Science.gov (United States)

    Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2012-11-01

    In order to develop novel glycolipid biosurfactants, Pseudozyma parantarctica JCM 11752(T), which is known as a producer of mannosylerythritol lipids (MEL), was cultivated using different sugar alcohols with the presence of vegetable oil. When cultivated in a medium containing 4 % (w/v) olive oil and 4 % D-ribitol or D-arabitol, the yeast strain provided different glycolipids, compared to the case of no sugar alcohol. On TLC, both of the extracted glycolipid fractions gave two major spots corresponding to MEL-A (di-acetylated MEL) and MEL-B (mono-acetylated MEL). Based on (1)H NMR analysis, one glycolipid was identified as MEL-A, but the other was not MEL-B. On high-performance liquid chromatography after acid hydrolysis, the unknown glycolipid from the D-ribitol culture provided mainly two peaks identical to D-mannose and D-ribitol, and the other unknown glycolipid from the D-arabitol culture did two peaks identical to D-mannose and D-arabitol. Accordingly, the two unknown glycolipids were identified as mannosylribitol lipid (MRL) and mannosylarabitol lipid (MAL), respectively. The observed critical micelle concentration (CMC) and surface tension at CMC of MRL were 1.6 × 10(-6) M and 23.7 mN/m, and those of MAL were 1.5 × 10(-6) M and 24.2 mN/m, respectively. These surface-tension-lowering activities were significantly higher compared to conventional MEL. Furthermore, on a water-penetration scan, MRL and MAL efficiently formed not only the lamella phase (L(α)) but also the myelins at a wide range of concentrations, indicating their excellent self-assembling properties and high hydrophilicity. The present two glycolipids should thus facilitate the application of biosurfactants as new functional materials. PMID:22722912

  8. Genome Sequence of the Basidiomycetous Yeast Pseudozyma antarctica T-34, a Producer of the Glycolipid Biosurfactants Mannosylerythritol Lipids.

    Science.gov (United States)

    Morita, Tomotake; Koike, Hideaki; Koyama, Yoshinori; Hagiwara, Hiroko; Ito, Emi; Fukuoka, Tokuma; Imura, Tomohiro; Machida, Masayuki; Kitamoto, Dai

    2013-01-01

    The basidiomycetous yeast Pseudozyma antarctica T-34 is an excellent producer of mannosylerythritol lipids (MELs), members of the multifunctional extracellular glycolipids, from various feedstocks. Here, the genome sequence of P. antarctica T-34 was determined and annotated. Analysis of the sequence might provide insights into the properties of this yeast that make it superior for use in the production of functional glycolipids, leading to the further development of P. antarctica for industrial applications. PMID:23558529

  9. Importance of macrophage cholesterol content on the flux of cholesterol mass

    OpenAIRE

    Sankaranarayanan, Sandhya; de la Llera-Moya, Margarita; Drazul-Schrader, Denise; Asztalos, Bela F.; Weibel, Ginny L.; Rothblat, George H.

    2010-01-01

    Net flux of cholesterol represents the difference between efflux and influx and can result in net cell-cholesterol accumulation, net cell-cholesterol depletion, or no change in cellular cholesterol content. We measured radiolabeled cell-cholesterol efflux and cell-cholesterol mass using cholesterol-normal and -enriched J774 and elicited mouse peritoneal macrophage cells. Net cell-cholesterol effluxes were observed when cholesterol-enriched J774 cells were incubated with 3.5% apolipoprotein (a...

  10. Formation of W/O microemulsion based on natural glycolipid biosurfactant, mannosylerythritol lipid-a.

    Science.gov (United States)

    Worakitkanchanakul, Wannasiri; Imura, Tomohiro; Morita, Tomotake; Fukuoka, Tokuma; Sakai, Hideki; Abe, Masahiko; Rujiravanit, Ratana; Chavadej, Sumaeth; Kitamoto, Dai

    2008-01-01

    Mannosylerythritol lipid-A (MEL-A) is a glycolipid biosurfactant abundantly produced from soybean oil by microorganisms at a yield of up to 100 g/L. In this study, the formation of water-in-oil (W/O) microemulsion based on the single component of MEL-A was confirmed using dynamic light scattering (DLS) and freeze fracture electron microscopy (FF-EM). DLS and FF-EM measurements revealed that the diameter of the microemulsion increases with an increase in water-to-surfactant mole ratio (W(0)) ranging from 20 to 60 nm, and the maximum W(0) value was found to be 20, which is as high as that of soybean lecithin. Glycolipid biosurfactant has a great potential for the formation of W/O microemulsion without using any cosurfactants. PMID:18075224

  11. Production of glycolipid biosurfactants, mannosylerythritol lipids, by a smut fungus, Ustilago scitaminea NBRC 32730.

    Science.gov (United States)

    Morita, Tomotake; Ishibashi, Yuko; Fukuoka, Tokuma; Imura, Tomohiro; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2009-03-23

    A smut fungus Ustilago scitaminea NBRC 32730 on sugar cane (Saccharum) was found to accumulate a large amount of glycolipids in the culture medium. As a result of structural characterization, the main glycolipid was identified as MEL-B, 4-O-beta-(2',3'-di-O-alka(e)noyl-6'-O-acetyl-D-mannopyranosyl)-erythritol. The MEL-B was sufficiently produced from a variety of sugars such as sucrose, glucose, fructose, and mannose. Olive oil and methyl oleate were also available as carbon sources to produce MEL-B. However, these residual oils made product recovery very complicated. Under optimal conditions, a maximum MEL yield of 12.8 g/l was achieved by feeding of sucrose. PMID:19270362

  12. Antimycobacterial action of a new glycolipid-peptide complex obtained from extracellular metabolites of Raoultella ornithinolytica.

    Science.gov (United States)

    Fiołka, Marta J; Grzywnowicz, Krzysztof; Mendyk, Ewaryst; Zagaja, Mirosław; Szewczyk, Rafał; Rawski, Michał; Keller, Radosław; Rzymowska, Jolanta; Wydrych, Jerzy

    2015-12-01

    In this paper, an antimycobacterial component of extracellular metabolites of a gut bacterium Raoultella ornithinolytica from D. veneta earthworms was isolated and its antimycobacterial action was tested using Mycobacterium smegmatis. After incubation with the complex obtained, formation of pores and furrows in cell walls was observed using microscopic techniques. The cells lost their shape, stuck together and formed clusters. Surface-enhanced Raman spectroscopy analysis showed that, after incubation, the complex was attached to the cell walls of the Mycobacterium. Analyses of the component performed with Fourier transform infrared spectroscopy demonstrated high similarity to a bacteriocin nisin, but energy dispersive X-ray spectroscopy analysis revealed differences in the elemental composition of this antimicrobial peptide. The component with antimycobacterial activity was identified using mass spectrometry techniques as a glycolipid-peptide complex. As it exhibits no cytotoxicity on normal human fibroblasts, the glycolipid-peptide complex appears to be a promising compound for investigations of its activity against pathogenic mycobacteria. PMID:26547373

  13. Antimycobacterial action of a new glycolipid-peptide complex obtained from extracellular metabolites of Raoultella ornithinolytica.

    Science.gov (United States)

    Fiołka, Marta J; Grzywnowicz, Krzysztof; Mendyk, Ewaryst; Zagaja, Mirosław; Szewczyk, Rafał; Rawski, Michał; Keller, Radosław; Rzymowska, Jolanta; Wydrych, Jerzy

    2015-12-01

    In this paper, an antimycobacterial component of extracellular metabolites of a gut bacterium Raoultella ornithinolytica from D. veneta earthworms was isolated and its antimycobacterial action was tested using Mycobacterium smegmatis. After incubation with the complex obtained, formation of pores and furrows in cell walls was observed using microscopic techniques. The cells lost their shape, stuck together and formed clusters. Surface-enhanced Raman spectroscopy analysis showed that, after incubation, the complex was attached to the cell walls of the Mycobacterium. Analyses of the component performed with Fourier transform infrared spectroscopy demonstrated high similarity to a bacteriocin nisin, but energy dispersive X-ray spectroscopy analysis revealed differences in the elemental composition of this antimicrobial peptide. The component with antimycobacterial activity was identified using mass spectrometry techniques as a glycolipid-peptide complex. As it exhibits no cytotoxicity on normal human fibroblasts, the glycolipid-peptide complex appears to be a promising compound for investigations of its activity against pathogenic mycobacteria.

  14. Fatty alcohols can complement functions of heterocyst specific glycolipids in Anabaena sp. PCC 7120.

    Science.gov (United States)

    Halimatul, Heli Siti Munawaroh; Ehira, Shigeki; Awai, Koichiro

    2014-07-18

    Heterocyst glycolipid synthase (HglT) catalyzes the final step of heterocyst glycolipid (Hgl) biosynthesis, in which a glucose is transferred to the aglycone (fatty alcohol). Here we describe the isolation of hglT null mutants. These mutants lacked Hgls under nitrogen-starved conditions and instead accumulated fatty alcohols. Differentiated heterocyst cells in the mutants were morphologically indistinguishable from those of the wild-type cells. Interestingly, the mutants grew under nitrogen starvation but fixed nitrogen with lower nitrogenase activity than did the wild-type. The mutants had a pale green phenotype with a decreased chlorophyll content, especially under nitrogen-starved conditions. These results suggest that the glucose moiety of the Hgls may be necessary for optimal protection against oxygen influx but is not essential and that aglycones can function as barriers against oxygen influx in the heterocyst cells.

  15. Decay accelerating factor (DAF) is anchored to membranes by a C-terminal glycolipid

    International Nuclear Information System (INIS)

    Purified 70 kDa membrane (m) DAF incorporates into cells when added in vitro. A 2 kDa smaller DAF form which functions extrinsically like C4bp but is unable to incorporate can be isolated from urine (u). Because of common deficits of mDAF and acetylcholinesterase (AChE) in erythrocytes (E) of patients with paroxysmal nocturnal hemoglobinuria (PNH), mDAF was analyzed for a O-terminal glycolipid membrane anchor similar to that in E AChE. Incubation of E with phosphatidylinositol-specific phospholipase C, an enzyme which cleaves a similar glycolipid anchor in trypanosome variant surface glycoproteins (mfVSGs), released 20% of the DAF antigen. The released DAF species resembled uDAF in size, extrinsic model of C4b2a decay, and lack of hydrophobicity. Reductive radiomethylation of mDAF with [14C]HCHO and NaCNBH3 revealed ethanolamine and glucosamine in proportions similar to those in the E AChE glycolipid anchor. Papain cleavage of radiomethylated mDAF released the labeled ethanolamine and glucosamine in small O-terminal fragments from the residual DAF that retained N-terminal Asp. Following labeling of the anchors of mDAF and E AChE with the lipophilic photoreagent 3-trifluoromethyl-3-(m-[125I]iodophenyl)diazirine, cleavage at the glucosamine residue by deamination quantitatively released the label from both proteins. Biosynthetic labeling of Hela cells with [3H]ethanolamine resulted in rapid 3H incorporation into both 48 kDa proDAF and 70 kDa mDAF. These data indicate that mDAF is anchored by a glycolipid similar to that in E AChE, mfVSGs and Thy-1 antigen and raise the possibility that a defect in the assembly or attachment of this structure could account for the deficits of mDAF and E AChE in PNH

  16. Mannosylerythritol lipid, a yeast extracellular glycolipid, shows high binding affinity towards human immunoglobulin G

    Science.gov (United States)

    Im, Jae Hong; Nakane, Takashi; Yanagishita, Hiroshi; Ikegami, Toru; Kitamoto, Dai

    2001-01-01

    Background There have been many attempts to develop new materials with stability and high affinity towards immunoglobulins. Some of glycolipids such as gangliosides exhibit a high affinity toward immunoglobulins. However, it is considerably difficult to develop these glycolipids into the practical separation ligand due to their limited amounts. We thus focused our attention on the feasible use of "mannosylerythritol lipid A", a yeast glycolipid biosurfactant, as an alternative ligand for immunoglobulins, and undertook the investigation on the binding between mannosylerythritol lipid A (MEL-A) and human immunoglobulin G (HIgG). Results In ELISA assay, MEL-A showed nearly the same binding affinity towards HIgG as that of bovine ganglioside GM1. Fab of human IgG was considered to play a more important role than Fc in the binding of HIgG by MEL-A. The bound amount of HIgG increased depending on the attached amount of MEL-A onto poly (2-hydroxyethyl methacrylate) (polyHEMA) beads, whereas the amount of human serum albumin slightly decreased. Binding-amount and -selectivity of HIgG towards MEL-A were influenced by salt species, salt concentration and pH in the buffer solution. The composite of MEL-A and polyHEMA, exhibited a significant binding constant of 1.43 × 106 (M-1) for HIgG, which is approximately 4-fold greater than that of protein A reported. Conclusions MEL-A shows high binding-affinity towards HIgG, and this is considered to be due to "multivalent effect" based on the binding molar ratio. This is the first report on the binding of a natural human antibody towards a yeast glycolipid. PMID:11604104

  17. The challenges of understanding glycolipid functions: An open outlook based on molecular simulations

    DEFF Research Database (Denmark)

    Manna, M.; Rog, T.; Vattulainen, I.

    2014-01-01

    Glycolipids are the most complex lipid type in cell membranes, characterized by a great diversity of different structures and functions. The underlying atomistic/molecular interactions and mechanisms associated with these functions are not well understood. Here we discuss how atomistic and molecu......, and the significant added value that one would gain by bridging molecular simulations with experiments. This article is part of a Special Issue entitled Tools to study lipid functions. (C) 2014 Elsevier B.V. All rights reserved....

  18. Extension of the GLYCAM06 Biomolecular Force Field to Lipids, Lipid Bilayers and Glycolipids

    OpenAIRE

    Tessier, Matthew B; DeMarco, Mari L.; Yongye, Austin B.; Woods, Robert J.

    2008-01-01

    GLYCAM06 is a generalisable biomolecular force field that is extendible to diverse molecular classes in the spirit of a small-molecule force field. Here we report parameters for lipids, lipid bilayers and glycolipids for use with GLYCAM06. Only three lipid-specific atom types have been introduced, in keeping with the general philosophy of transferable parameter development. Bond stretching, angle bending, and torsional force constants were derived by fitting to quantum mechanical data for a c...

  19. Mannosylerythritol lipid, a yeast extracellular glycolipid, shows high binding affinity towards human immunoglobulin G

    Directory of Open Access Journals (Sweden)

    Ikegami Toru

    2001-09-01

    Full Text Available Abstract Background There have been many attempts to develop new materials with stability and high affinity towards immunoglobulins. Some of glycolipids such as gangliosides exhibit a high affinity toward immunoglobulins. However, it is considerably difficult to develop these glycolipids into the practical separation ligand due to their limited amounts. We thus focused our attention on the feasible use of "mannosylerythritol lipid A", a yeast glycolipid biosurfactant, as an alternative ligand for immunoglobulins, and undertook the investigation on the binding between mannosylerythritol lipid A (MEL-A and human immunoglobulin G (HIgG. Results In ELISA assay, MEL-A showed nearly the same binding affinity towards HIgG as that of bovine ganglioside GM1. Fab of human IgG was considered to play a more important role than Fc in the binding of HIgG by MEL-A. The bound amount of HIgG increased depending on the attached amount of MEL-A onto poly (2-hydroxyethyl methacrylate (polyHEMA beads, whereas the amount of human serum albumin slightly decreased. Binding-amount and -selectivity of HIgG towards MEL-A were influenced by salt species, salt concentration and pH in the buffer solution. The composite of MEL-A and polyHEMA, exhibited a significant binding constant of 1.43 × 106 (M-1 for HIgG, which is approximately 4-fold greater than that of protein A reported. Conclusions MEL-A shows high binding-affinity towards HIgG, and this is considered to be due to "multivalent effect" based on the binding molar ratio. This is the first report on the binding of a natural human antibody towards a yeast glycolipid.

  20. A glycolipid-anchored prion protein is endocytosed via clathrin-coated pits

    OpenAIRE

    1994-01-01

    The cellular prion protein (PrPc) is a glycolipid-anchored, cell surface protein of unknown function, a posttranslationally modified isoform of which PrPSc is involved in the pathogenesis of Creutzfeldt- Jakob disease, scrapie, and other spongiform encephalopathies. We have shown previously that chPrP, a chicken homologue of mammalian PrPC, constitutively cycles between the cell surface and an endocytic compartment, with a transit time of approximately 60 min in cultured neuroblastoma cells. ...

  1. Fossilized glycolipids reveal past oceanic N2 fixation by heterocystous cyanobacteria.

    Science.gov (United States)

    Bauersachs, Thorsten; Speelman, Eveline N; Hopmans, Ellen C; Reichart, Gert-Jan; Schouten, Stefan; Damsté, Jaap S Sinninghe

    2010-11-01

    N(2)-fixing cyanobacteria play an essential role in sustaining primary productivity in contemporary oceans and freshwater systems. However, the significance of N(2)-fixing cyanobacteria in past nitrogen cycling is difficult to establish as their preservation potential is relatively poor and specific biological markers are presently lacking. Heterocystous N(2)-fixing cyanobacteria synthesize unique long-chain glycolipids in the cell envelope covering the heterocyst cell to protect the oxygen-sensitive nitrogenase enzyme. We found that these heterocyst glycolipids are remarkably well preserved in (ancient) lacustrine and marine sediments, unambiguously indicating the (past) presence of N(2)-fixing heterocystous cyanobacteria. Analysis of Pleistocene sediments of the eastern Mediterranean Sea showed that heterocystous cyanobacteria, likely as epiphytes in symbiosis with planktonic diatoms, were particularly abundant during deposition of sapropels. Eocene Arctic Ocean sediments deposited at a time of large Azolla blooms contained glycolipids typical for heterocystous cyanobacteria presently living in symbiosis with the freshwater fern Azolla, indicating that this symbiosis already existed in that time. Our study thus suggests that heterocystous cyanobacteria played a major role in adding "new" fixed nitrogen to surface waters in past stratified oceans. PMID:20966349

  2. Food combinations for cholesterol lowering.

    Science.gov (United States)

    Harland, Janice I

    2012-12-01

    Reducing elevated LDL-cholesterol is a key public health challenge. There is substantial evidence from randomised controlled trials (RCT) that a number of foods and food components can significantly reduce LDL-cholesterol. Data from RCT have been reviewed to determine whether effects are additive when two or more of these components are consumed together. Typically components, such as plant stanols and sterols, soya protein, β-glucans and tree nuts, when consumed individually at their target rate, reduce LDL-cholesterol by 3-9 %. Improved dietary fat quality, achieved by replacing SFA with unsaturated fat, reduces LDL-cholesterol and can increase HDL-cholesterol, further improving blood lipid profile. It appears that the effect of combining these interventions is largely additive; however, compliance with multiple changes may reduce over time. Food combinations used in ten 'portfolio diet' studies have been reviewed. In clinical efficacy studies of about 1 month where all foods were provided, LDL-cholesterol is reduced by 22-30 %, whereas in community-based studies of >6 months' duration, where dietary advice is the basis of the intervention, reduction in LDL-cholesterol is about 15 %. Inclusion of MUFA into 'portfolio diets' increases HDL-cholesterol, in addition to LDL-cholesterol effects. Compliance with some of these dietary changes can be achieved more easily compared with others. By careful food component selection, appropriate to the individual, the effect of including only two components in the diet with good compliance could be a sustainable 10 % reduction in LDL-cholesterol; this is sufficient to make a substantial impact on cholesterol management and reduce the need for pharmaceutical intervention.

  3. Production of glycolipid biosurfactants, mannosylerythritol lipids, by Pseudozyma siamensis CBS 9960 and their interfacial properties.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2008-05-01

    The search for a novel producer of glycolipid biosurfactants, mannosylerythritol lipids (MELs), was undertaken on the basis of the analysis of ribosomal DNA sequences of yeast strains of the genus Pseudozyma. In the course of the investigation, Pseudozyma siamensis CBS 9960, which is closely related to Pseudozyma shanxiensis, a known MEL-C producer but with a different morphology, was found to accumulate a large amount of glycolipids. On thin layer chromatography, the extracellular glycolipids showed nearly the same spots as those of the MELs produced by P. shanxiensis. However, the result of high-performance liquid chromatography analysis revealed that the present strain has a much higher glycolipid production yield than P. shanxiensis. From the structural characterization by (1)H and (13)C NMR, the major glycolipid (more than 84% of the total) was identified as a mixture of 4-O-[(2',4'-di-O-acetyl-3'-O-alka(e)noyl)-beta-D-mannopyranosyl]-D-erythritol and 4-O-[(4'-O-acetyl-3'-O-alka(e)noyl-2'-O-butanoyl)-beta-D-mannopyranosyl]-D-erythritol, both of which are types of MEL-C. The present MEL-C possessed a short-chain acid (C(2) or C(4)) at the C-2' position and a long-chain acid (C(16)) at the C-3' position of the mannose moiety, and thus, the hydrophobic part was considerably different from that of conventional MELs, which mainly possess two medium-chain acids (C(10)) at the C-2' and C-3' positions. Under optimal growth conditions with safflower oil in a shake culture, the total amount of MELs reached approximately 19 g/l after 9 d at 25 degrees C. We further investigated the interfacial properties of the present MEL-C, considering its unique hydrophobic structure. The observed critical micelle concentration (CMC) and the surface tension at the CMC of the MEL were 4.5 x 10(-6) M and 30.7 mN/m, respectively. In addition, on a water penetration scan, the MEL efficiently formed the liquid crystal phases such as hexagonal (H) and lamella (L(a)) at a wide range of

  4. Reducing Cholesterol Intake: Are the recommendations valid?

    OpenAIRE

    Chan, Joanna K.; McDonald, Bruce E.

    1991-01-01

    The authors question dietary recommendations for the general public calling for reduced cholesterol intake. Metabolic studies have shown that dietary cholesterol normally induces only small increases in blood cholesterol level. There is evidence that only a portion of the population responds to a change in cholesterol intake; hence lowering dietary cholesterol will be effective for only some.

  5. The interaction of boron with glycolipids is required to increase tolerance to stresses in Anabaena PCC 7120.

    Science.gov (United States)

    Abreu, Isidro; Orús, Isabel; Bolaños, Luis; Bonilla, Ildefonso

    2014-10-01

    Boron (B) is an essential nutrient for heterocystous cyanobacteria growing under diazotrophic conditions. Under B-deficient conditions, the heterocyst envelope is highly disorganized, and the glycolipid layer is predominantly lost. Therefore, we examined whether B is implicated in the regulation of synthesis or processing and/or stability of glycolipids in Anabaena PCC 7120. RT-PCR analysis indicated that the expression of hglE was not significantly changed under B deficiency, suggesting that the synthesis of glycolipids during heterocyst formation was not compromised. In contrast, the overexpression of devB and hepA, encoding a glycolipid and a carbohydrate transporter, respectively, results in the instability of the envelope under B-deficient conditions. The capacity of borate to bind and stabilize molecules is considered the basis of any B biological function. Using a borate-binding-specific resin and thin layer chromatography, we detected the glycolipids that interact with B. Several heterocyst-specific glycolipids were detected as putative B ligands, suggesting a role for B in stabilizing the heterocyst envelope. Moreover, the glycolipids of Anabaena growing in non-diazotrophic conditions were also detected as putative B ligands. Although B is not essential for Anabaena under non-N2-fixing conditions, the presence of this micronutrient increased the tolerance of Anabaena to detergent treatment, salinity and hyperosmotic conditions. Taken together, the results of the present experiment suggest a beneficial role for B in environmental adaptation. Furthermore, we discuss the nutrient requirement for living organisms growing in nature and not under laboratory conditions.

  6. Epigenetic Regulation of Cholesterol Homeostasis

    Directory of Open Access Journals (Sweden)

    Steve eMeaney

    2014-09-01

    Full Text Available Although best known as a risk factor for cardiovascular disease, cholesterol is a vital component of all mammalian cells. In addition to key structural roles, cholesterol is a vital biochemical precursor for numerous biologically important compounds including oxysterols and bile acids, as well as acting as an activator of critical morphogenic systems (e.g. the Hedgehog system. A variety of sophisticated regulatory mechanisms interact to coordinate the overall level of cholesterol in cells, tissues and the entire organism. Accumulating evidence indicates that in additional to the more ‘traditional’ regulatory schemes, cholesterol homeostasis is also under the control of epigenetic mechanisms such as histone acetylation and DNA methylation. The available evidence supporting a role for these mechanisms in the control of cholesterol synthesis, elimination, transport and storage are the focus of this review.

  7. Inhibition of pancreatic cholesterol esterase reduces cholesterol absorption in the hamster

    OpenAIRE

    Heidrich, John E.; Contos, Linda M; Hunsaker, Lucy A; Deck, Lorraine M.; Vander Jagt, David L.

    2004-01-01

    Background Pancreatic cholesterol esterase has three proposed functions in the intestine: 1) to control the bioavailability of cholesterol from dietary cholesterol esters; 2) to contribute to incorporation of cholesterol into mixed micelles; and 3) to aid in transport of free cholesterol to the enterocyte. Inhibitors of cholesterol esterase are anticipated to limit the absorption of dietary cholesterol. Results The selective and potent cholesterol esterase inhibitor 6-chloro-3-(1-ethyl-2-cycl...

  8. Understand Your Risk for High Cholesterol

    Science.gov (United States)

    ... Resources Stroke More Understand Your Risk for High Cholesterol Updated:Apr 1,2016 LDL (bad) cholesterol is ... content was last reviewed on 04/21/2014. Cholesterol Guidelines: Putting the pieces together Myth vs. Truth – ...

  9. Overview of Cholesterol and Lipid Disorders

    Science.gov (United States)

    ... Medical Dictionary Additional Content Medical News Overview of Cholesterol and Lipid Disorders By Anne Carol Goldberg, MD ... Version. DOCTORS: Click here for the Professional Version Cholesterol Disorders Overview of Cholesterol and Lipid Disorders Dyslipidemia ...

  10. Cholesterol - what to ask your doctor

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000211.htm Cholesterol - what to ask your doctor To use the ... this page, please enable JavaScript. Your body needs cholesterol to work properly. When you have extra cholesterol ...

  11. Evolutionary constrained optimization

    CERN Document Server

    Deb, Kalyanmoy

    2015-01-01

    This book makes available a self-contained collection of modern research addressing the general constrained optimization problems using evolutionary algorithms. Broadly the topics covered include constraint handling for single and multi-objective optimizations; penalty function based methodology; multi-objective based methodology; new constraint handling mechanism; hybrid methodology; scaling issues in constrained optimization; design of scalable test problems; parameter adaptation in constrained optimization; handling of integer, discrete and mix variables in addition to continuous variables; application of constraint handling techniques to real-world problems; and constrained optimization in dynamic environment. There is also a separate chapter on hybrid optimization, which is gaining lots of popularity nowadays due to its capability of bridging the gap between evolutionary and classical optimization. The material in the book is useful to researchers, novice, and experts alike. The book will also be useful...

  12. Identification of Ustilago cynodontis as a new producer of glycolipid biosurfactants, mannosylerythritol lipids, based on ribosomal DNA sequences.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2008-01-01

    Mannosylerythritol lipids (MELs) are one of the most promising glycolipid biosurfactants known because of their multifunctionality and biocompatibility. The search for novel producers of MELs was undertaken based on the analysis of ribosomal DNA sequences on basidiomycetous yeasts. The bermuda grass smut fungus Ustilago cynodontis NBRC 7530, which taxonomically relates to Pseudozyma shanxiensis known as a MEL-C producer, was found to accumulate glycolipids in the cultured medium. Under a shake flask culture with soybean oil, the amount of the glycolipids was 1.4 g/L for 7 days at 25 degrees C. As a result of the structural characterization, the main glycolipids was identified as 4-O-[(4'-O-acetyl-3'-O-alka(e)noyl-2'-O-butanoyl)-beta-D-mannopyranosyl]-D-erythritol, and the major fatty acids were C(14) and C(16) ones. The glycolipid was highly hydrophilic MEL-C, and very similar to those produced by P. shanxiensis. The fungi of the genus Ustilago are thus likely to be potential producers of MELs as well as the yeasts of the genus Pseudozyma. PMID:18781055

  13. A single subset of dendritic cells controls the cytokine bias of natural killer T cell responses to diverse glycolipid antigens.

    Science.gov (United States)

    Arora, Pooja; Baena, Andres; Yu, Karl O A; Saini, Neeraj K; Kharkwal, Shalu S; Goldberg, Michael F; Kunnath-Velayudhan, Shajo; Carreño, Leandro J; Venkataswamy, Manjunatha M; Kim, John; Lazar-Molnar, Eszter; Lauvau, Gregoire; Chang, Young-tae; Liu, Zheng; Bittman, Robert; Al-Shamkhani, Aymen; Cox, Liam R; Jervis, Peter J; Veerapen, Natacha; Besra, Gurdyal S; Porcelli, Steven A

    2014-01-16

    Many hematopoietic cell types express CD1d and are capable of presenting glycolipid antigens to invariant natural killer T cells (iNKT cells). However, the question of which cells are the principal presenters of glycolipid antigens in vivo remains controversial, and it has been suggested that this might vary depending on the structure of a particular glycolipid antigen. Here we have shown that a single type of cell, the CD8α(+) DEC-205(+) dendritic cell, was mainly responsible for capturing and presenting a variety of different glycolipid antigens, including multiple forms of α-galactosylceramide that stimulate widely divergent cytokine responses. After glycolipid presentation, these dendritic cells rapidly altered their expression of various costimulatory and coinhibitory molecules in a manner that was dependent on the structure of the antigen. These findings show flexibility in the outcome of two-way communication between CD8α(+) dendritic cells and iNKT cells, providing a mechanism for biasing toward either proinflammatory or anti-inflammatory responses.

  14. Characterization of placental cholesterol transport

    DEFF Research Database (Denmark)

    Lindegaard, Marie L; Wassif, Christopher A; Vaisman, Boris;

    2008-01-01

    circulation might attenuate congenital malformations. The cholesterol transporters Abca1, Abcg1, and Sr-b1 are present in placenta; however, their potential role in placental transport remains undetermined. In mice, expression analyses showed that Abca1 and Abcg1 transcripts increased 2-3-fold between...... embryonic days 13.5 and 18.5 in placental tissue; whereas, Sr-b1 expression decreased. To examine the functional role of Abca1, Abcg1 and Sr-b1 we measured the maternal-fetal transfer of (14)C-cholesterol in corresponding mutant embryos. Disruption of either Abca1 or Sr-b1 decreased cholesterol transfer...

  15. Synthesis of serine-based glycolipids as potential TLR4 activators.

    Science.gov (United States)

    Huang, Li-De; Lin, Hong-Jyune; Huang, Po-Hsiung; Hsiao, Wei-Chen; Reddy, L Vijaya Raghava; Fu, Shu-Ling; Lin, Chun-Cheng

    2011-04-01

    A new series of monosaccharide-based glycolipids devoid of phosphate groups and with two lipid chains were rationally designed by varying the lipid chain lengths and saccharide structure of a α-GalCer-derived lead compound (CCL-34) that is a potent TLR4 agonist. The NF-κB activity of a 60-membered galactosyl serine-based synthetic library containing compounds with various lipid chain lengths was measured in a HEK293 cell line that stably expressed human TLR4, MD2, and CD14 (293-hTLR4/MD2-CD14). The results showed that the optimal carbon chain lengths for the lipid amine and fatty acid to activate TLR4 were 10-11 and 12, respectively. Evaluation of a 20-membered synthetic glycosyl serine-based lipid library containing compounds with various saccharide moieties and fixed lipid chain lengths revealed that the galactose moiety in CCL-34 could be replaced by glucose without loss of activity (CCL-34-S3 and CCL-34-S16). Changing the orientation of the anomeric glycosidic bond of CCL-34 resulted in a complete loss of activity (β-CCL34). Surprisingly, a change in configuration of the anomeric glycosidic bond in a glucosyl glycolipid is tolerable (CCL-34-S14). Another noteworthy observation is that the activity of a l-fucosyl derived glycolipid (CCL-34-S13) was comparable to that of CCL-34. In sum, this study determines the structural features that are crucial for an optimal TLR4-stimulating activity. It also provides several molecules with immunostimulating potential.

  16. Effect of glycolipids of Leishmania parasites on human monocyte activity. Inhibition by lipophosphoglycan.

    Science.gov (United States)

    Frankenburg, S; Leibovici, V; Mansbach, N; Turco, S J; Rosen, G

    1990-12-15

    Lipophosphoglycan (LPG) and glycosyl phosphatidylinositol Ag (GPI), are glycolipids present on the membrane of Leishmania parasites. Both glycolipids have been chemically characterized. LPG is a polysaccharide of repeating phosphorylated units linked to a phosphocarbohydrate core that is anchored to the membrane by lysoalkyl phosphatidylinositol (PI). The GPI are smaller glycolipids with a structure resembling the phosphocarbohydrate core of the LPG. They are anchored to the membrane by alkyl acyl PI. Their relative abundance, uniqueness of structure, and cellular location suggest a role in interactions of the parasites with host cells. In the present study we examined the effect of LPG and GPI on the activation of human peripheral blood monocytes. Three parameters were studied: the production of IL-1, chemotactic locomotion, and oxidative burst. We found that whereas neither GPI nor LPG directly affected monocyte activity, preincubation of the monocytes with LPG strongly inhibited further activation: The production of IL-1, after stimulation with LPS, was decreased in a dose-dependent manner. Previous incubation with LPG also inhibited chemotactic locomotion of monocytes and neutrophils in response to diacylglycerol, zymosan-activated serum, FMLP and LTB4. Luminol-dependent chemiluminiscence caused by stimulation of the monocytes with streptococci and histone was also inhibited. After fragmentation of the LPG into phosphoglycan and 1-O-alkylglycerol by phosphatidylinositol-phospholipase C, only the phosphoglycan retained inhibitory activity. No difference in inhibitory activity was found between LPG prepared from Leishmania major or Leishmania donovani promastigotes. These results show that the phosphoglycan of LPG inhibits the immunologic response of normal human monocytes and neutrophils, and suggest that LPG may influence the nature of the inflammatory response surrounding infected cells. PMID:2147940

  17. Membrane Glycolipids Content Variety in Gastrointestinal Tumors and Transplantable Hepatomas in Mice.

    Science.gov (United States)

    Lv, Jun; Lv, Can Qun; Wang, Bo-Liang; Mei, Ping; Xu, Lei

    2016-01-01

    BACKGROUND The aim of this study was to investigate the variety of plasma contents of membrane glycolipids in 65 gastrointestinal tumors and 31 transplant hepatomas in mice. MATERIAL AND METHODS The experimental model was a transplantable murine hepatoma. Experimental mice were divided into 3 groups. RESULTS The LSA and TSA content in the 2 groups were significantly difference (pTSA are sensitive markers in gastrointestinal tumors. In the transplanted hepatomas in mice, they may be considered as ancillary indicators for judging the therapeutic effect of hepatoma. PMID:27554918

  18. EVALUATION OF GLYCOLIPIDS OF SOME EGYPTIAN MARINE ALGAE AS A SOURCE OF BIOACTIVE SUBSTANCES

    Directory of Open Access Journals (Sweden)

    El Baroty Gamal S

    2011-03-01

    Full Text Available Glycolipids in five species of marine algae: two species of Rhodophyta (Laurencia popillose, Galaxoura cylindriea; and one species of Chlorophyta (Ulva fasciata, and two species of Phaeophyta (Dilophys fasciola, Taonia atomaria collected from Red and Mediterranean sea, respectively were extracted, purified on silica gel column chromatography and identified by liquid chromatography MS/MS. Total glycolipid contents (GL (as % of total lipid were found to be in ranges 10.9 to 28.7%. T. atomaria had the highest level (28.7% followed by L. popillose (22.5 %. GL groups were analyzed for their sugars and fatty acids composition, and the result showed that the highest carbohydrate content of GLs were found in U. fasciata (6.05% and L. popillose (5.8%, and characterized by high content of monosaccharide: mannouronic acid, galactose and rhamnose. Amongst of the glycolipids of algal species, the most predominate fatty acid identified by GC were palmatic (C16:0 19.20 - 65.89% of total fatty acid, ecosatrienoic (C20:3 7.52 - 54.41%. GL analyzed by LC/MS/MS, revealed the peak at m/z 956 corresponding to the molecular formula of C51H104O17 was the most abundant molecular ion among all GLs of algal species and its fragments peaks at m/z 617(C37H58O4 and m/z 337 (C21H58O3, were tentatively identified as digalactosyldiacylglycerol (DGDG. The in vitro anticancer, antimicrobial, and antiviral activities of algal glycolipids were evaluated. GL of all algae species showed a remarkable antiviral activity in dose dependent manner. GL from D. fasciola has shown the most potent effect against HSV1 (IC50 of 10 µg/ml, comparable to that of the current antiviral drug acyclovir (IC50 55 µg/ml. On the other hand, GL of all algal species possessed a moderate antimicrobial activity. GL of T. atomaria exhibited a high inhibition effects against all test microorganisms, with MIC value ranged from 60 to 80 µg/ml. Moreover, all algal GL exhibited remarkable anticancer activities

  19. Imaging appearances of cholesterol pneumonia

    International Nuclear Information System (INIS)

    Objection: To analyze the imaging appearances of cholesterol pneumonia. Methods We retrospectively analyzed the X-ray and CT findings of 3 patients with cholesterol pneumonia confirmed pathologically and reviewed correlative literature. Results: Lesions similar to mass were found in X-ray and CT imaging of three cases. Two of them appeared cavity with fluid-level and one showed multiple ring enhancement after CT contrast. The course of disease was very. long and it had no respond to antibiotic therapy. Amounts of foam cells rich in cholesterol crystal were detected in pathological examination. Conclusions: Cholesterol pneumonia is a rare chronic pulmonary idiopathic disease, and the radiological findings can do some help to its diagnosis. (authors)

  20. Cholesterol testing on a smartphone.

    Science.gov (United States)

    Oncescu, Vlad; Mancuso, Matthew; Erickson, David

    2014-02-21

    Home self-diagnostic tools for blood cholesterol monitoring have been around for over a decade but their widespread adoption has been limited by the relatively high cost of acquiring a quantitative test-strip reader, complicated procedure for operating the device, and inability to easily store and process results. To address this we have developed a smartphone accessory and software application that allows for the quantification of cholesterol levels in blood. Through a series of human trials we demonstrate that the system can accurately quantify total cholesterol levels in blood within 60 s by imaging standard test strips. In addition, we demonstrate how our accessory is optimized to improve measurement sensitivity and reproducibility across different individual smartphones. With the widespread adoption of smartphones and increasingly sophisticated image processing technology, accessories such as the one presented here will allow cholesterol monitoring to become more accurate and widespread, greatly improving preventive care for cardiovascular disease.

  1. Cholesterol's location in lipid bilayers.

    Science.gov (United States)

    Marquardt, Drew; Kučerka, Norbert; Wassall, Stephen R; Harroun, Thad A; Katsaras, John

    2016-09-01

    It is well known that cholesterol modifies the physical properties of lipid bilayers. For example, the much studied liquid-ordered Lo phase contains rapidly diffusing lipids with their acyl chains in the all trans configuration, similar to gel phase bilayers. Moreover, the Lo phase is commonly associated with cholesterol-enriched lipid rafts, which are thought to serve as platforms for signaling proteins in the plasma membrane. Cholesterol's location in lipid bilayers has been studied extensively, and it has been shown - at least in some bilayers - to align differently from its canonical upright orientation, where its hydroxyl group is in the vicinity of the lipid-water interface. In this article we review recent works describing cholesterol's location in different model membrane systems with emphasis on results obtained from scattering, spectroscopic and molecular dynamics studies. PMID:27056099

  2. Formation of cholesterol bilayer domains precedes formation of cholesterol crystals in cholesterol/dimyristoylphosphatidylcholine membranes: EPR and DSC studies.

    Science.gov (United States)

    Mainali, Laxman; Raguz, Marija; Subczynski, Witold K

    2013-08-01

    Saturation-recovery EPR along with DSC were used to determine the cholesterol content at which pure cholesterol bilayer domains (CBDs) and cholesterol crystals begin to form in dimyristoylphosphatidylcholine (DMPC) membranes. To preserve compositional homogeneity throughout the membrane suspension, lipid multilamellar dispersions were prepared using a rapid solvent exchange method. The cholesterol content increased from 0 to 75 mol %. With spin-labeled cholesterol analogues, it was shown that the CBDs begin to form at ~50 mol % cholesterol. It was confirmed by DSC that the cholesterol solubility threshold for DMPC membranes is detected at ~66 mol % cholesterol. At levels above this cholesterol content, monohydrate cholesterol crystals start to form. The major finding is that the formation of CBDs precedes formation of cholesterol crystals. The region of the phase diagram for cholesterol contents between 50 and 66 mol % is described as a structured one-phase region in which CBDs have to be supported by the surrounding DMPC bilayer saturated with cholesterol. Thus, the phase boundary located at 66 mol % cholesterol separates the structured one-phase region (liquid-ordered phase of DMPC with CBDs) from the two-phase region where the structured liquid-ordered phase of DMPC coexists with cholesterol crystals. It is likely that CBDs are precursors of monohydrate cholesterol crystals.

  3. Cholesterol Worships a New Idol

    Institute of Scientific and Technical Information of China (English)

    Ira G. Schulman

    2009-01-01

    The growing worldwide epidemic of cardiovascular disease suggests that new therapeutic strategies are needed to complement statins in the lowering of cholesterol levels. In a recent paper in Science, Tontonoz and colleagues have identified Idol as a protein that can control cholesterol levels by regulating the stability of the low-density lipoprotein receptor; inhibiting the activity of Idol could provide novel approaches for the treatment of cardiovascular disease.

  4. A relation between high-density-lipoprotein cholesterol and bile cholesterol saturation.

    OpenAIRE

    Thornton, J R; Heaton, K. W.; Macfarlane, D G

    1981-01-01

    The association of cholesterol gall stones with coronary artery disease is controversial. To investigate this possible relation at the biochemical level, bile cholesterol saturation and the plasma concentrations of triglycerides, total cholesterol, and high-density-lipoprotein cholesterol (HDL cholesterol) were measured in 25 healthy, middle-aged women. Bile cholesterol saturation index was negatively correlated with HDL cholesterol. It was positively correlated with plasma triglycerides and ...

  5. Choosing health, constrained choices.

    Science.gov (United States)

    Chee Khoon Chan

    2009-12-01

    In parallel with the neo-liberal retrenchment of the welfarist state, an increasing emphasis on the responsibility of individuals in managing their own affairs and their well-being has been evident. In the health arena for instance, this was a major theme permeating the UK government's White Paper Choosing Health: Making Healthy Choices Easier (2004), which appealed to an ethos of autonomy and self-actualization through activity and consumption which merited esteem. As a counterpoint to this growing trend of informed responsibilization, constrained choices (constrained agency) provides a useful framework for a judicious balance and sense of proportion between an individual behavioural focus and a focus on societal, systemic, and structural determinants of health and well-being. Constrained choices is also a conceptual bridge between responsibilization and population health which could be further developed within an integrative biosocial perspective one might refer to as the social ecology of health and disease.

  6. Formation of Cholesterol Bilayer Domains Precedes Formation of Cholesterol Crystals in Cholesterol/Dimyristoylphosphatidylcholine Membranes: EPR and DSC Studies

    OpenAIRE

    Mainali, Laxman; Raguz, Marija; Subczynski, Witold K.

    2013-01-01

    Saturation-recovery EPR along with DSC were used to determine the cholesterol content at which pure cholesterol bilayer domains (CBDs) and cholesterol crystals begin to form in dimyristoylphosphatidylcholine (DMPC) membranes. To preserve compositional homogeneity throughout the membrane suspension, lipid multilamellar dispersions were prepared using a rapid solvent exchange method. The cholesterol content increased from 0 to 75 mol%. With spin-labeled cholesterol analogs it was shown that the...

  7. Facts about...Blood Cholesterol. Revised.

    Science.gov (United States)

    National Heart, Lung, and Blood Inst. (DHHS/NIH), Bethesda, MD.

    This fact sheet on blood cholesterol examines the connection between cholesterol and heart disease, lists risk factors for heart disease that can and cannot be controlled, points out who can benefit from lowering blood cholesterol, distinguishes between blood and dietary cholesterol, describes low density lipoprotein and high density lipoprotein…

  8. Phosphatidylcholine: Greasing the Cholesterol Transport Machinery

    Science.gov (United States)

    Lagace, Thomas A.

    2015-01-01

    Negative feedback regulation of cholesterol metabolism in mammalian cells ensures a proper balance of cholesterol with other membrane lipids, principal among these being the major phospholipid phosphatidylcholine (PC). Processes such as cholesterol biosynthesis and efflux, cholesteryl ester storage in lipid droplets, and uptake of plasma lipoproteins are tuned to the cholesterol/PC ratio. Cholesterol-loaded macrophages in atherosclerotic lesions display increased PC biosynthesis that buffers against elevated cholesterol levels and may also facilitate cholesterol trafficking to enhance cholesterol sensing and efflux. These same mechanisms could play a generic role in homeostatic responses to acute changes in membrane free cholesterol levels. Here, I discuss the established and emerging roles of PC metabolism in promoting intracellular cholesterol trafficking and membrane lipid homeostasis. PMID:27081313

  9. Major surface antigen, P30, of Toxoplasma gondii is anchored by a glycolipid

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, S.D.; Boothroyd, J.C.

    1989-04-05

    P30, the major surface antigen of the parasitic protozoan Toxoplasma gondii, can be specifically labeled with (/sup 3/H)palmitic acid and with myo-(2-/sup 3/H)inositol. The fatty acid label can be released by treatment of P30 with phosphatidylinositol-specific phospholipase C (PI-PLC). Such treatment exposes an immunological cross-reacting determinant first described on Trypanosoma brucei variant surface glycoprotein. PI-PLC cleavage of intact parasites metabolically labeled with (/sup 35/S)methionine results in the release of intact P30 polypeptide in a form which migrates faster in polyacrylamide gel electrophoresis. These results argue that P30 is anchored by a glycolipid. Results from thin layer chromatography analysis of purified (/sup 3/H) palmitate-labeled P30 treated with PI-PLC, together with susceptibility to mild alkali hydrolysis and to cleavage with phospholipase A2, suggest that the glycolipid anchor of T. gondii P30 includes a 1,2-diacylglycerol moiety.

  10. The neurite-initiating effect of microbial extracellular glycolipids in PC12 cells.

    Science.gov (United States)

    Isoda, H; Shinmoto, H; Matsumura, M; Nakahara, T

    1999-09-01

    The effects of several kinds of microbial extracellular glycolipids on neurite initiation in PC12 cells were examined. Addition of mannosylerythritol lipid-A (MEL-A), MEL-B, and sophorose lipid (SL) to PC12 cells caused significant neurite outgrowth. Other glycolipids, such as polyol lipid (PL), rhamnose lipid (RL), succinoyl trehalose lipid-A (STL-A) and STL-B caused no neurite-initiation. MEL-A increased acetylcholine esterase (AChE) activity to an extent similar to nerve growth factor (NGF). However, MEL-A induced one or two long neurites from the cell body, while NGF induced many neurites. In addition, MEL-A-induced differentiation was transient, and after 48 h, percentage of cells with neurites started to decrease in contrast to neurons induced by NGF, which occurred in a time-dependent manner. MEL-A could induce neurite outgrowth after treatment of PC12 cells with an anti-NGF receptor antibody that obstructed NGF action. These results indicate that MEL-A and NGF induce differentiation of PC12 cells through different mechanisms. PMID:19003137

  11. Aqueous-phase behavior of natural glycolipid biosurfactant mannosylerythritol lipid A: sponge, cubic, and lamellar phases.

    Science.gov (United States)

    Imura, Tomohiro; Hikosaka, Yusuke; Worakitkanchanakul, Wannasiri; Sakai, Hideki; Abe, Masahiko; Konishi, Masaaki; Minamikawa, Hiroyuki; Kitamoto, Dai

    2007-02-13

    The aqueous-phase behavior of mannosylerythritol lipid A (MEL-A), which is a glycolipid biosurfactant produced from vegetable oils by yeast strains of the genus Pseudozyma, was investigated using polarized optical microscopy, small-angle X-ray scattering (SAXS), and differential scanning calorimetry (DSC). MEL-A was found to self-assemble into a variety of distinctive lyotropic liquid crystals including sponge (L3), bicontinuous cubic (V2), and lamella (Lalpha) phases. On the basis of SAXS measurements, we determined the structure of the liquid crystals. The estimated lattice constant for Lalpha was 3.58 nm. DSC measurement revealed that the phase transition enthalpies from the liquid crystal to the fluid isotropic phase were in the range of 0.22-0.44 kJ/mol. Although the present MEL-A phase diagram closely resembled that obtained from relatively hydrophobic poly(oxyethylene) or fluorinated surfactants, the MEL-A L3 region was spread considerably over a wide temperature range (20-65 degrees C) compared to L3 of those surfactants: this is probably due to the unique structure which is molecularly engineered by microorganisms. In this paper, we clarify the aqueous phase diagram of the natural glycolipid biosurfactant MEL-A, and we suggest that the obtained lyotropic crystals are potentially useful as novel nanostructured biomaterials. PMID:17279642

  12. The moisturizing effects of glycolipid biosurfactants, mannosylerythritol lipids, on human skin.

    Science.gov (United States)

    Yamamoto, Shuhei; Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Yanagidani, Shusaku; Sogabe, Atsushi; Kitamoto, Dai; Kitagawa, Masaru

    2012-01-01

    Glycolipid biosurfactants, such as mannosylerythritol lipids (MELs), are produced by different yeasts belonging to the genus Pseudozyma and have been attracting much attention as new cosmetic ingredients owing to their unique liquid-crystal-forming and moisturizing properties. In this study, the effects of different MEL derivatives on the skin were evaluated in detail using a three-dimensional cultured human skin model and an in vivo human study. The skin cells were cultured and treated with sodium dodecyl sulfate (SDS), and the effects of different lipids on the SDS-damaged cells were evaluated on the basis of cell viability. Most MEL derivatives efficiently recovered the viability of the cells and showed high recovery rates (over 80%) comparable with that of natural ceramide. It is interesting that the recovery rate with MEL-A prepared from olive oil was significantly higher than that of MEL-A prepared from soybean oil. The water retention properties of MEL-B were further investigated on human forearm skin in a preliminary study. Compared with the control, the aqueous solution of MEL-B (5 wt%) was estimated to considerably increase the stratum corneum water content in the skin. Moreover, perspiration on the skin surface was clearly suppressed by treatment with the MEL-B solution. These results suggest that MELs are likely to exhibit a high moisturizing action, by assisting the barrier function of the skin. Accordingly, the yeast glycolipids have a strong potential as a new ingredient for skin care products. PMID:22790172

  13. Enzymatic synthesis of a novel glycolipid biosurfactant, mannosylerythritol lipid-D and its aqueous phase behavior.

    Science.gov (United States)

    Fukuoka, Tokuma; Yanagihara, Takashi; Imura, Tomohiro; Morita, Tomotake; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2011-02-01

    Mannosylerythritol lipids (MELs) produced by yeasts are one of the most promising glycolipid biosurfactants. In this study, we succeeded in the preparation of a novel MEL homolog having no acetyl groups, namely MEL-D. MEL-D was synthesized by lipase-catalyzed hydrolysis of acetyl groups from a known MEL, and identified as 4-O-[2',3'-di-O-alka(e)noyl-β-d-mannopyranosyl]-(2R,3S)-erythritol. The obtained MEL-D showed a higher critical aggregation concentration (CAC=1.2 × 10(-5)M) and hydrophilicity compared to known MELs, retaining an excellent surface tension lowering activity (the surface tension at the CAC was 24.5mN/m). In addition, we estimated the binary phase diagram of the MEL-D-water system based on a combination of visual inspection, polarized optical microscopy, and SAXS measurement. From these results, MEL-D was found to self-assemble into a lamellar (L(α)) structure over all ranges of concentration. Meanwhile, the one-phase L(α) region of MEL-D was extended wider than those of known MELs. MEL-D might keep more water between the polar layers in accordance with the extension of the interlayer spacing (d). These results suggest that the newly obtained MEL-D would facilitate the application of MELs in various fields as a lamellar-forming glycolipid with higher hydrate ability. PMID:21163471

  14. Extension of the GLYCAM06 Biomolecular Force Field to Lipids, Lipid Bilayers and Glycolipids.

    Science.gov (United States)

    Tessier, Matthew B; Demarco, Mari L; Yongye, Austin B; Woods, Robert J

    2008-01-01

    GLYCAM06 is a generalisable biomolecular force field that is extendible to diverse molecular classes in the spirit of a small-molecule force field. Here we report parameters for lipids, lipid bilayers and glycolipids for use with GLYCAM06. Only three lipid-specific atom types have been introduced, in keeping with the general philosophy of transferable parameter development. Bond stretching, angle bending, and torsional force constants were derived by fitting to quantum mechanical data for a collection of minimal molecular fragments and related small molecules. Partial atomic charges were computed by fitting to ensemble-averaged quantum-computed molecular electrostatic potentials.In addition to reproducing quantum mechanical internal rotational energies and experimental valence geometries for an array of small molecules, condensed-phase simulations employing the new parameters are shown to reproduce the bulk physical properties of a DMPC lipid bilayer. The new parameters allow for molecular dynamics simulations of complex systems containing lipids, lipid bilayers, glycolipids, and carbohydrates, using an internally consistent force field. By combining the AMBER parameters for proteins with the GLYCAM06 parameters, it is also possible to simulate protein-lipid complexes and proteins in biologically relevant membrane-like environments. PMID:22247593

  15. Proteomic analysis of the metabolic adaptation of the biocontrol agent Pseudozyma flocculosa leading to glycolipid production

    Directory of Open Access Journals (Sweden)

    Bélanger Richard R

    2010-02-01

    Full Text Available Abstract The yeast-like epiphytic fungus Pseudozyma flocculosa is known to antagonize powdery mildew fungi through proliferation on colonies presumably preceded by the release of an antifungal glycolipid (flocculosin. In culture conditions, P. flocculosa can be induced to produce or not flocculosin through manipulation of the culture medium nutrients. In order to characterize and understand the metabolic changes in P. flocculosa linked to glycolipid production, we conducted a 2-DE proteomic analysis and compared the proteomic profile of P. flocculosa growing under conditions favoring the development of the fungus (control or conducive to flocculosin synthesis (stress. A large number of protein spots (771 were detected in protein extracts of the control treatment compared to only 435 matched protein spots in extracts of the stress cultures, which clearly suggests an important metabolic reorganization in slow-growing cells producing flocculosin. From the latter treatment, we were able to identify 21 protein spots that were either specific to the treatment or up-regulated significantly (2-fold increase. All of them were identified based on similarity between predicted ORF of the newly sequenced genome of P. flocculosa with Ustilago maydis' available annotated sequences. These proteins were associated with the carbon and fatty acid metabolism, and also with the filamentous change of the fungus leading to flocculosin production. This first look into the proteome of P. flocculosa suggests that flocculosin synthesis is elicited in response to specific stress or limiting conditions.

  16. Constrained Jastrow calculations

    International Nuclear Information System (INIS)

    An alternative to Pandharipande's lowest order constrained variational prescription for dense Fermi fluids is presented which is justified on both physical and strict variational grounds. Excellent results are obtained when applied to the 'homework problem' of Bethe, in sharp contrast to those obtained from the Pandharipande prescription. (Auth.)

  17. Constrained superfields in Supergravity

    CERN Document Server

    Dall'Agata, Gianguido

    2015-01-01

    We analyze constrained superfields in supergravity. We investigate the consistency and solve all known constraints, presenting a new class that may have interesting applications in the construction of inflationary models. We provide the superspace Lagrangians for minimal supergravity models based on them and write the corresponding theories in component form using a simplifying gauge for the goldstino couplings.

  18. Microbial conversion of glycerol into glycolipid biosurfactants, mannosylerythritol lipids, by a basidiomycete yeast, Pseudozyma antarctica JCM 10317(T).

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2007-07-01

    Microbial conversion of glycerol into functional bio-based materials was investigated, aiming to facilitate the utilization of waste glycerol. A basidiomycete yeast, Pseudozyma antarctica JCM 10317, efficiently produced mannosylerythritol lipids (MELs) as glycolipid biosurfactants from glycerol. The amount of MEL yield reached 16.3 g l(-1) by intermittent feeding of glycerol. PMID:17697987

  19. Draft Genome Sequence of the Yeast Pseudozyma antarctica Type Strain JCM10317, a Producer of the Glycolipid Biosurfactants, Mannosylerythritol Lipids.

    Science.gov (United States)

    Saika, Azusa; Koike, Hideaki; Hori, Tomoyuki; Fukuoka, Tokuma; Sato, Shun; Habe, Hiroshi; Kitamoto, Dai; Morita, Tomotake

    2014-01-01

    The basidiomycetous yeast Pseudozyma antarctica is known as a producer of industrial enzymes and the extracellular glycolipids, mannosylerythritol lipids. Here, we report the draft genome sequence of the type strain JCM10317. The draft genome assembly has a size of 18.1 Mb and a G+C content of 60.9%, and it consists of 197 scaffolds. PMID:25291760

  20. Transcytosis of immunoglobulin A in the mouse enterocyte occurs through glycolipid raft- and rab17-containing compartments

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Niels-Christiansen, L L; Immerdal, Lissi;

    1999-01-01

    BACKGROUND & AIMS: Glycolipid "rafts" have been shown to play a role in apical membrane trafficking in the enterocyte. The present study characterized the membrane compartments of the enterocyte involved in transepithelial transport of small intestinal immunoglobulin A (IgA). Methods: Immunogold ...

  1. Cholesterol confusion and statin controversy

    Institute of Scientific and Technical Information of China (English)

    Robert; Du; Broff; Michel; de; Lorgeril

    2015-01-01

    The role of blood cholesterol levels in coronary heart disease(CHD) and the true effect of cholesterollowering statin drugs are debatable. In particular,whether statins actually decrease cardiac mortality and increase life expectancy is controversial. Concurrently,the Mediterranean diet model has been shown to prolong life and reduce the risk of diabetes,cancer,and CHD. We herein review current data related to both statins and the Mediterranean diet. We conclude that the expectation that CHD could be prevented or eliminated by simply reducing cholesterol appears unfounded. On the contrary,we should acknowledge the inconsistencies of the cholesterol theory and recognize the proven benefits of a healthy lifestyle incorporating a Mediterranean diet to prevent CHD.

  2. Sharp spatially constrained inversion

    DEFF Research Database (Denmark)

    Vignoli, Giulio G.; Fiandaca, Gianluca G.; Christiansen, Anders Vest C A.V.C.;

    2013-01-01

    We present sharp reconstruction of multi-layer models using a spatially constrained inversion with minimum gradient support regularization. In particular, its application to airborne electromagnetic data is discussed. Airborne surveys produce extremely large datasets, traditionally inverted...... by using smoothly varying 1D models. Smoothness is a result of the regularization constraints applied to address the inversion ill-posedness. The standard Occam-type regularized multi-layer inversion produces results where boundaries between layers are smeared. The sharp regularization overcomes......, the results are compatible with the data and, at the same time, favor sharp transitions. The focusing strategy can also be used to constrain the 1D solutions laterally, guaranteeing that lateral sharp transitions are retrieved without losing resolution. By means of real and synthetic datasets, sharp...

  3. Polarizable multipolar electrostatics for cholesterol

    Science.gov (United States)

    Fletcher, Timothy L.; Popelier, Paul L. A.

    2016-08-01

    FFLUX is a novel force field under development for biomolecular modelling, and is based on topological atoms and the machine learning method kriging. Successful kriging models have been obtained for realistic electrostatics of amino acids, small peptides, and some carbohydrates but here, for the first time, we construct kriging models for a sizeable ligand of great importance, which is cholesterol. Cholesterol's mean total (internal) electrostatic energy prediction error amounts to 3.9 kJ mol-1, which pleasingly falls below the threshold of 1 kcal mol-1 often cited for accurate biomolecular modelling. We present a detailed analysis of the error distributions.

  4. Regulation of biliary cholesterol secretion and reverse cholesterol transport

    NARCIS (Netherlands)

    Dikkers, Arne

    2016-01-01

    According to the World Health Organization the number one cause of death throughout the world is cardiovascular disease. Therefore, there is an urgent need for new therapeutic strategies to prevent and treat cardiovascular disease. One possible way is to target the HDL-driven reverse cholesterol tra

  5. Expression of α2,6-sialic acid-containing and Lewis-active glycolipids in several types of human ovarian carcinomas

    OpenAIRE

    Tanaka, Kyoko; Mikami, Mikio; Aoki, Daisuke; Kiguchi, Kazushige; Ishiwata, Isamu; IWAMORI, MASAO

    2010-01-01

    To identify glycolipid antigens associated with histologically defined types of ovarian carcinomas, we determined the amounts of α2,6-sialyl and Lewis-active glycolipids, the specific activities of the α2,3- and α2,6-sialyltransferases, and the gene expression of sugar transferases in mucinous and serous cystadenocarcinoma, clear cell adenocarcinoma and endometrioid carcinoma tissues and cell lines derived from them. α2,6-sialyl glycolipid IV6NeuAcα-nLc4Cer detected with a newly developed mon...

  6. Reverse vesicle formation from the yeast glycolipid biosurfactant mannosylerythritol lipid-D.

    Science.gov (United States)

    Fukuoka, Tokuma; Yanagihara, Takashi; Ito, Seya; Imura, Tomohiro; Morita, Tomotake; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2012-01-01

    Mannosylerythritol lipids (MELs) are secreted by yeasts and are promising glycolipid biosurfactants. In our study on the non-aqueous phase behaviors of MEL homologues, we found that MEL-D (4-O-[2',3'-di-O-alka(e)noyl-β-D-mannopyranosyl]-(2R,3S)-erythritol) forms aggregates in decane. The microscopic observation and the X-ray scattering measurement of these aggregates revealed that they are reverse vesicles that consist of bilayers whose hydrophilic domains are located in the interior of the bilayers. In addition, MEL-D formed reverse vesicles without co-surfactants and co-solvents in various oily solutions, such as n-alkanes, cyclohexane, squalane, squalene, and silicone oils at a concentration below 10 mM. This is the first report on the reverse vesicle formation from biosurfactants. PMID:22531056

  7. Membrane Cholesterol Modulates Superwarfarin Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Marangoni, M. Natalia; Martynowycz, Michael W.; Kuzmenko, Ivan; Braun, David; Polak, Paul E.; Weinberg, Guy; Rubinstein, Israel; Gidalevitz, David; Feinstein, Douglas L.

    2016-04-26

    Superwarfarins are modified analogs of warfarin with additional lipophilic aromatic rings, up to 100-fold greater potency, and longer biological half-lives. We hypothesized that increased hydrophobicity allowed interactions with amphiphilic membranes and modulation of biological responses. We find that superwarfarins brodifacoum and difenacoum increase lactate production and cell death in neuroblastoma cells. In contrast, neither causes changes in glioma cells that have higher cholesterol content. After choleterol depletion, lactate production was increased and cell viability was reduced. Drug-membrane interactions were examined by surface X-ray scattering using Langmuir monolayers of dipalmitoylphosphatidylcholine and/or cholesterol. Specular X-ray reflectivity data revealed that superwarfarins, but not warfarin, intercalate between dipalmitoylphosphatidylcholine molecules, whereas grazing incidence X-ray diffraction demonstrated changes in lateral crystalline order of the film. Neither agent showed significant interactions with monolayers containing >20% cholesterol. These findings demonstrate an affinity of superwarfarins to biomembranes and suggest that cellular responses to these agents are regulated by cholesterol content.

  8. The ABC of cholesterol transport

    NARCIS (Netherlands)

    Plösch, Torsten

    2004-01-01

    Cholesterol fulfills an indispensable role in mammalian physiology. It is an important constituent of all cell membranes. Furthermore, it is the precursor of steroid hormones, which regulate a variety of physiological functions, and of bile salts, which are necessary for the generation of bile flow

  9. Membrane Cholesterol Modulates Superwarfarin Toxicity.

    Science.gov (United States)

    Marangoni, M Natalia; Martynowycz, Michael W; Kuzmenko, Ivan; Braun, David; Polak, Paul E; Weinberg, Guy; Rubinstein, Israel; Gidalevitz, David; Feinstein, Douglas L

    2016-04-26

    Superwarfarins are modified analogs of warfarin with additional lipophilic aromatic rings, up to 100-fold greater potency, and longer biological half-lives. We hypothesized that increased hydrophobicity allowed interactions with amphiphilic membranes and modulation of biological responses. We find that superwarfarins brodifacoum and difenacoum increase lactate production and cell death in neuroblastoma cells. In contrast, neither causes changes in glioma cells that have higher cholesterol content. After choleterol depletion, lactate production was increased and cell viability was reduced. Drug-membrane interactions were examined by surface X-ray scattering using Langmuir monolayers of dipalmitoylphosphatidylcholine and/or cholesterol. Specular X-ray reflectivity data revealed that superwarfarins, but not warfarin, intercalate between dipalmitoylphosphatidylcholine molecules, whereas grazing incidence X-ray diffraction demonstrated changes in lateral crystalline order of the film. Neither agent showed significant interactions with monolayers containing >20% cholesterol. These findings demonstrate an affinity of superwarfarins to biomembranes and suggest that cellular responses to these agents are regulated by cholesterol content. PMID:27119638

  10. Decay accelerating factor of complement is anchored to cells by a C-terminal glycolipid

    International Nuclear Information System (INIS)

    Membrane-associated decay accelerating factor (DAF) of human erythrocytes (E/sup hu/) was analyzed for a C-terminal glycolipid anchoring structure. Automated amino acid analysis of DAF following reductive radiomethylation revealed ethanolamine and glucosamine residues in proportions identical with those present in the E/sup hu/ acetylcholinesterase (AChE) anchor. Cleavage of radiomethylated 70-kilodalton (kDa) DAF with papain released the labeled ethanolamine and glucosamine and generated 61- and 55-kDa DAF products that retained all labeled Lys and labeled N-terminal Asp. Incubation of intact E/sup hu/ with phosphatidylinositol-specific phospholipase C (PI-PLC), which cleaves the anchors in trypanosome membrane form variant surface glycoproteins (mfVSGs) and murine thymocyte Thy-1 antigen, released 15% of the cell-associated DAF antigen. The released 67-kDa PI-PLC DAF derivative retained its ability to decay the classical C3 convertase C4b2a but was unable to membrane-incorporate and displayed physicochemical properties similar to urine DAF, a hydrophilic DAF form that can be isolated for urine. Nitrous acid deamination cleavage of E/sup hu/ DAF at glucosamine following labeling with the lipophilic photoreagent 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine ([125I]TID) released the [125I]TID label in a parallel fashion as from [125I]TID-labeled AChE. Biosynthetic labeling of HeLa cells with [3H] ethanolamine resulted in rapid 3H incorporation into both 48-kDa pro-DAF and 72-kDa mature epithelial cell DAF. The findings indicate that DAF and AChE are anchored in E/sup hu/ by the same or a similar glycolipid structure and that, like VSGs, this structure is incorporated into DAF early in DAF biosynthesis prior to processing of pro-DAF in the Golgi

  11. Th1-skewed tissue responses to a mycolyl glycolipid in mycobacteria-infected rhesus macaques

    International Nuclear Information System (INIS)

    Highlights: •Glucose monomycolate (GMM) is a marker glycolipid for active tuberculosis. •Tissue responses to GMM involved up-regulation of Th1-attracting chemokines. •Th1-skewed local responses were mounted at the GMM-injected tissue. -- Abstract: Trehalose 6,6′-dimycolate (TDM) is a major glycolipid of the cell wall of mycobacteria with remarkable adjuvant functions. To avoid detection by the host innate immune system, invading mycobacteria down-regulate the expression of TDM by utilizing host-derived glucose as a competitive substrate for their mycolyltransferases; however, this enzymatic reaction results in the concomitant biosynthesis of glucose monomycolate (GMM) which is recognized by the acquired immune system. GMM-specific, CD1-restricted T cell responses have been detected in the peripheral blood of infected human subjects and monkeys as well as in secondary lymphoid organs of small animals, such as guinea pigs and human CD1-transgenic mice. Nevertheless, it remains to be determined how tissues respond at the site where GMM is produced. Here we found that rhesus macaques vaccinated with Mycobacterium bovis bacillus Calmette–Guerin mounted a chemokine response in GMM-challenged skin that was favorable for recruiting T helper (Th)1 T cells. Indeed, the expression of interferon-γ, but not Th2 or Th17 cytokines, was prominent in the GMM-injected tissue. The GMM-elicited tissue response was also associated with the expression of monocyte/macrophage-attracting CC chemokines, such as CCL2, CCL4 and CCL8. Furthermore, the skin response to GMM involved the up-regulated expression of granulysin and perforin. Given that GMM is produced primarily by pathogenic mycobacteria proliferating within the host, the Th1-skewed tissue response to GMM may function efficiently at the site of infection

  12. Th1-skewed tissue responses to a mycolyl glycolipid in mycobacteria-infected rhesus macaques

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Daisuke; Miyamoto, Ayumi; Hattori, Yuki; Komori, Takaya [Laboratory of Cell Regulation, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Nakamura, Takashi [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Igarashi, Tatsuhiko, E-mail: tigarash@virus.kyoto-u.ac.jp [Laboratory of Primate Model, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Harashima, Hideyoshi, E-mail: harasima@pharm.hokudai.ac.jp [Faculty of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo, Hokkaido 060-0812 (Japan); Sugita, Masahiko, E-mail: msugita@virus.kyoto-u.ac.jp [Laboratory of Cell Regulation, Institute for Virus Research, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan)

    2013-11-08

    Highlights: •Glucose monomycolate (GMM) is a marker glycolipid for active tuberculosis. •Tissue responses to GMM involved up-regulation of Th1-attracting chemokines. •Th1-skewed local responses were mounted at the GMM-injected tissue. -- Abstract: Trehalose 6,6′-dimycolate (TDM) is a major glycolipid of the cell wall of mycobacteria with remarkable adjuvant functions. To avoid detection by the host innate immune system, invading mycobacteria down-regulate the expression of TDM by utilizing host-derived glucose as a competitive substrate for their mycolyltransferases; however, this enzymatic reaction results in the concomitant biosynthesis of glucose monomycolate (GMM) which is recognized by the acquired immune system. GMM-specific, CD1-restricted T cell responses have been detected in the peripheral blood of infected human subjects and monkeys as well as in secondary lymphoid organs of small animals, such as guinea pigs and human CD1-transgenic mice. Nevertheless, it remains to be determined how tissues respond at the site where GMM is produced. Here we found that rhesus macaques vaccinated with Mycobacterium bovis bacillus Calmette–Guerin mounted a chemokine response in GMM-challenged skin that was favorable for recruiting T helper (Th)1 T cells. Indeed, the expression of interferon-γ, but not Th2 or Th17 cytokines, was prominent in the GMM-injected tissue. The GMM-elicited tissue response was also associated with the expression of monocyte/macrophage-attracting CC chemokines, such as CCL2, CCL4 and CCL8. Furthermore, the skin response to GMM involved the up-regulated expression of granulysin and perforin. Given that GMM is produced primarily by pathogenic mycobacteria proliferating within the host, the Th1-skewed tissue response to GMM may function efficiently at the site of infection.

  13. Aqueous-phase behavior and vesicle formation of natural glycolipid biosurfactant, mannosylerythritol lipid-B.

    Science.gov (United States)

    Worakitkanchanakul, Wannasiri; Imura, Tomohiro; Fukuoka, Tokuma; Morita, Tomotake; Sakai, Hideki; Abe, Masahiko; Rujiravanit, Ratana; Chavadej, Sumaeth; Minamikawa, Hiroyuki; Kitamoto, Dai

    2008-08-01

    Mannosylerythritol lipids (MELs) are one of the most promising glycolipid biosurfactants produced by yeast strains of the genus Pseudozyma. In this study, the aqueous-phase behavior of a new monoacetyl MEL derivative, 1-O-beta-(2',3'-di-O-alka(e)noyl-6'-O-acetyl-d-mannopyranosyl)-d-erythritol (MEL-B), was investigated using polarized optical microscopy, small-angle X-ray scattering (SAXS), confocal laser scanning microscopy (CLSM), and differential scanning calorimetry (DSC). The present MEL-B was found to self-assemble into a lamellar (L(alpha)) phase over remarkably wide concentration and temperature ranges. According to SAXS measurement, the interlayer spacing (d) was estimated to be almost constant (about 4.7 nm) at the low MEL-B concentration (60 wt.%) region, the d-spacing gradually decreased to 3.1 nm with an increase in the MEL-B concentration. The thermal stability of the liquid crystalline phase was investigated by DSC measurement. The obtained L(alpha) phase was found to be stable up to 95 degrees C below a MEL-B concentration of 85 wt.%; then, the melting temperature of the liquid crystalline phase dramatically decreased with an increase in MEL-B concentration (above 85 wt.%). Furthermore, we found relatively large vesicles (1-5 microm) at the low MEL-B concentration using CLSM observation. The trapped volume of the obtained MEL-B vesicle was estimated to be about 0.42 microL/mumol by glucose dialysis method. These results suggest that the natural glycolipid biosurfactant, the newly found MEL-B, would be useful in various fields of applications as an L(alpha) phase- and/or vesicle-forming lipid. PMID:18456469

  14. pH-Driven Self-Assembly of Acidic Microbial Glycolipids.

    Science.gov (United States)

    Baccile, Niki; Selmane, Mohamed; Le Griel, Patrick; Prévost, Sylvain; Perez, Javier; Stevens, Christian V; Delbeke, Elisabeth; Zibek, Susanne; Guenther, Michael; Soetaert, Wim; Van Bogaert, Inge N A; Roelants, Sophie

    2016-06-28

    Microbial glycolipids are a class of well-known compounds, but their self-assembly behavior is still not well understood. While the free carboxylic acid end group makes some of them interesting stimuli-responsive compounds, the sugar hydrophilic group and the nature of the fatty acid chain make the understanding of their self-assembly behavior in water not easy and highly unpredictable. Using cryo-transmission electron microscopy (cryo-TEM) and both pH-dependent in situ and ex situ small angle X-ray scattering (SAXS), we demonstrate that the aqueous self-assembly at room temperature (RT) of a family of β-d-glucose microbial glycolipids bearing a saturated and monounsaturated C18 fatty acid chain cannot be explained on the simple basis of the well-known packing parameter. Using the "pH-jump" process, we find that the molecules bearing a monosaturated fatty acid forms vesicles below pH 6.2, as expected, but the derivative with a saturated fatty acid forms infinite bilayer sheets below pH 7.8, instead of vesicles. We show that this behavior can be explained on the different bilayer membrane elasticity as a function of temperature. Membranes are either flexible or stiff for experiments performed at a temperature respectively above or below the typical melting point, TM, of the lipidic part of each compound. Finally, we also show that the disaccharide-containing acidic cellobioselipid forms a majority of chiral fibers, instead of the expected micelles. PMID:27307097

  15. Constraining entropic cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Koivisto, Tomi S. [Institute for Theoretical Physics and the Spinoza Institute, Utrecht University, Leuvenlaan 4, Postbus 80.195, 3508 TD Utrecht (Netherlands); Mota, David F. [Institute of Theoretical Astrophysics, University of Oslo, 0315 Oslo (Norway); Zumalacárregui, Miguel, E-mail: t.s.koivisto@uu.nl, E-mail: d.f.mota@astro.uio.no, E-mail: miguelzuma@icc.ub.edu [Institute of Cosmos Sciences (ICC-IEEC), University of Barcelona, Marti i Franques 1, E-08028 Barcelona (Spain)

    2011-02-01

    It has been recently proposed that the interpretation of gravity as an emergent, entropic phenomenon might have nontrivial implications to cosmology. Here several such approaches are investigated and the underlying assumptions that must be made in order to constrain them by the BBN, SneIa, BAO and CMB data are clarified. Present models of inflation or dark energy are ruled out by the data. Constraints are derived on phenomenological parameterizations of modified Friedmann equations and some features of entropic scenarios regarding the growth of perturbations, the no-go theorem for entropic inflation and the possible violation of the Bekenstein bound for the entropy of the Universe are discussed and clarified.

  16. Lectures on Constrained Systems

    CERN Document Server

    Date, Ghanashyam

    2010-01-01

    These lecture notes were prepared as a basic introduction to the theory of constrained systems which is how the fundamental forces of nature appear in their Hamiltonian formulation. Only a working knowledge of Lagrangian and Hamiltonian formulation of mechanics is assumed. These notes are based on the set of eight lectures given at the {\\em Refresher Course for College Teachers} held at IMSc during May-June, 2005. These are submitted to the arxiv for an easy access to a wider body of students.

  17. Symmetrically Constrained Compositions

    CERN Document Server

    Beck, Matthias; Lee, Sunyoung; Savage, Carla D

    2009-01-01

    Given integers $a_1, a_2, ..., a_n$, with $a_1 + a_2 + ... + a_n \\geq 1$, a symmetrically constrained composition $\\lambda_1 + lambda_2 + ... + lambda_n = M$ of $M$ into $n$ nonnegative parts is one that satisfies each of the the $n!$ constraints ${\\sum_{i=1}^n a_i \\lambda_{\\pi(i)} \\geq 0 : \\pi \\in S_n}$. We show how to compute the generating function of these compositions, combining methods from partition theory, permutation statistics, and lattice-point enumeration.

  18. Active membrane cholesterol as a physiological effector.

    Science.gov (United States)

    Lange, Yvonne; Steck, Theodore L

    2016-09-01

    Sterols associate preferentially with plasma membrane sphingolipids and saturated phospholipids to form stoichiometric complexes. Cholesterol in molar excess of the capacity of these polar bilayer lipids has a high accessibility and fugacity; we call this fraction active cholesterol. This review first considers how active cholesterol serves as an upstream regulator of cellular sterol homeostasis. The mechanism appears to utilize the redistribution of active cholesterol down its diffusional gradient to the endoplasmic reticulum and mitochondria, where it binds multiple effectors and directs their feedback activity. We have also reviewed a broad literature in search of a role for active cholesterol (as opposed to bulk cholesterol or lipid domains such as rafts) in the activity of diverse membrane proteins. Several systems provide such evidence, implicating, in particular, caveolin-1, various kinds of ABC-type cholesterol transporters, solute transporters, receptors and ion channels. We suggest that this larger role for active cholesterol warrants close attention and can be tested easily. PMID:26874289

  19. Do You Know Your Cholesterol Levels?

    Science.gov (United States)

    ... The Health Information Center Do You Know Your Cholesterol Levels? Print-friendly Version (PDF, 6.1 MB) ... Eat Smart Did you know that high blood cholesterol is a serious problem among Latinos? About one ...

  20. Analysis of Cholesterol Trafficking with Fluorescent Probes

    DEFF Research Database (Denmark)

    Maxfield, Frederick R.; Wustner, Daniel

    2012-01-01

    Cholesterol plays an important role in determining the biophysical properties of biological membranes, and its concentration is tightly controlled by homeostatic processes. The intracellular transport of cholesterol among organelles is a key part of the homeostatic mechanism, but sterol transport...... that can bind to cholesterol to reveal its distribution in cells. We also discuss the use of intrinsically fluorescent sterols that closely mimic cholesterol, as well as some minimally modified fluorophore-labeled sterols. Methods for imaging these sterols by conventional fluorescence microscopy...

  1. Cerebral cholesterol granuloma in homozygous familial hypercholesterolemia

    OpenAIRE

    Francis, Gordon A; Johnson, Royce L.; Findlay, J. Max; Wang, Jian; Hegele, Robert A.

    2005-01-01

    Familial hypercholesterolemia (FH) is characterized by the accumulation of excess cholesterol in tissues including the artery wall and tendons. We describe a patient with homozygous FH who presented with asymptomatic cholesterol granuloma of the brain. The patient's plasma low-density lipoprotein cholesterol level was remarkably responsive to combination hypolipidemic therapy with statin plus ezetimibe. This case illustrates another potential complication of whole-body cholesterol excess and ...

  2. Space Constrained Dynamic Covering

    CERN Document Server

    Antonellis, Ioannis; Dughmi, Shaddin

    2009-01-01

    In this paper, we identify a fundamental algorithmic problem that we term space-constrained dynamic covering (SCDC), arising in many modern-day web applications, including ad-serving and online recommendation systems in eBay and Netflix. Roughly speaking, SCDC applies two restrictions to the well-studied Max-Coverage problem: Given an integer k, X={1,2,...,n} and I={S_1, ..., S_m}, S_i a subset of X, find a subset J of I, such that |J| <= k and the union of S in J is as large as possible. The two restrictions applied by SCDC are: (1) Dynamic: At query-time, we are given a query Q, a subset of X, and our goal is to find J such that the intersection of Q with the union of S in J is as large as possible; (2) Space-constrained: We don't have enough space to store (and process) the entire input; specifically, we have o(mn), sometimes even as little as O((m+n)polylog(mn)) space. The goal of SCDC is to maintain a small data structure so as to answer most dynamic queries with high accuracy. We present algorithms a...

  3. Intestinal cholesterol secretion : future clinical implications

    NARCIS (Netherlands)

    Jakulj, L.; Besseling, J.; Stroes, E. S. G.; Groen, A. K.

    2013-01-01

    Together with the liver, the intestine serves as a homeostatic organ in cholesterol metabolism. Recent evidence has substantiated the pivotal role of the intestine in reverse cholesterol transport (RCT). RCT is a fundamental antiatherogenic pathway, mediating the removal of cholesterol from tissues

  4. Isolation of Cholesterol from an Egg Yolk

    Science.gov (United States)

    Taber, Douglass F.; Li, Rui; Anson, Cory M.

    2011-01-01

    A simple procedure for the isolation of the cholesterol, by hydrolysis and extraction followed by column chromatography, is described. The cholesterol can be further purified by complexation with oxalic acid. It can also be oxidized and conjugated to cholestenone. The source of the cholesterol is one egg yolk, which contains about 200 mg of…

  5. Public health aspects of serum cholesterol

    NARCIS (Netherlands)

    S. Houterman (Saskia)

    2001-01-01

    textabstractIn the beginning of this century Anitschkow and De Langen started pioneering work concerning the relation between cholesterol and coronary heart disease. Both showed that there was a possible relation between cholesterol in the diet, blood cholesterol levels and atherosclerosis. It took

  6. Remnant cholesterol and ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G

    2014-01-01

    PURPOSE OF REVIEW: To review recent advances in the field of remnant cholesterol as a contributor to the development of ischemic heart disease (IHD). RECENT FINDINGS: Epidemiologic, mechanistic, and genetic studies all support a role for elevated remnant cholesterol (=cholesterol in triglyceride...

  7. High Cholesterol: Medicines to Help You

    Science.gov (United States)

    ... risks of taking these medicines. Talk to your doctor or pharmacist about all of the risks of taking your ... 20 should have their cholesterol checked by a doctor. Most people do not show ... Good vs. Bad Cholesterol Not all cholesterol in your blood ...

  8. Cholesterol Screening: A Practical Guide to Implementation.

    Science.gov (United States)

    Kingery, Paul M.

    1995-01-01

    Dry-chemistry cholesterol analysis has made screening feasible in a variety of settings. The article provides practical tips for the implementation of mass cholesterol screening using a portable dry-chemistry analyzer and discusses issues involved in conducting effective cholesterol screening programs from start to finish. (SM)

  9. Non-cholesterol sterols and cholesterol metabolism in sitosterolemia.

    Science.gov (United States)

    Othman, Rgia A; Myrie, Semone B; Jones, Peter J H

    2013-12-01

    Sitosterolemia (STSL) is a rare autosomal recessive disease, manifested by extremely elevated plant sterols (PS) in plasma and tissue, leading to xanthoma and premature atherosclerotic disease. Therapeutic approaches include limiting PS intake, interrupting enterohepatic circulation of bile acid using bile acid binding resins such as cholestyramine, and/or ileal bypass, and inhibiting intestinal sterol absorption by ezetimibe (EZE). The objective of this review is to evaluate sterol metabolism in STSL and the impact of the currently available treatments on sterol trafficking in this disease. The role of PS in initiation of xanthomas and premature atherosclerosis is also discussed. Blocking sterols absorption with EZE has revolutionized STSL patient treatment as it reduces circulating levels of non-cholesterol sterols in STSL. However, none of the available treatments including EZE have normalized plasma PS concentrations. Future studies are needed to: (i) explore where cholesterol and non-cholesterol sterols accumulate, (ii) assess to what extent these sterols in tissues can be mobilized after blocking their absorption, and (iii) define the factors governing sterol flux.

  10. Cholesterol Depletion from a Ceramide/Cholesterol Mixed Monolayer: A Brewster Angle Microscope Study

    KAUST Repository

    Mandal, Pritam

    2016-06-01

    Cholesterol is crucial to the mechanical properties of cell membranes that are important to cells’ behavior. Its depletion from the cell membranes could be dramatic. Among cyclodextrins (CDs), methyl beta cyclodextrin (MβCD) is the most efficient to deplete cholesterol (Chol) from biomembranes. Here, we focus on the depletion of cholesterol from a C16 ceramide/cholesterol (C16-Cer/Chol) mixed monolayer using MβCD. While the removal of cholesterol by MβCD depends on the cholesterol concentration in most mixed lipid monolayers, it does not depend very much on the concentration of cholesterol in C16-Cer/Chol monolayers. The surface pressure decay during depletion were described by a stretched exponential that suggested that the cholesterol molecules are unable to diffuse laterally and behave like static traps for the MβCD molecules. Cholesterol depletion causes morphology changes of domains but these disrupted monolayers domains seem to reform even when cholesterol level was low.

  11. Relationship between plasma cholesterol levels and cholesterol esterification in isolated human mononuclear cells

    Energy Technology Data Exchange (ETDEWEB)

    Dallongeville, J.; Davignon, J.; Lussier-Cacan, S. (Clinical Research Institute of Montreal, Quebec (Canada))

    1990-01-01

    The authors studied the relationship between plasma lipoprotein concentrations and cholesterol esterification in freshly isolated human mononuclear cells from 27 normolipidemic and 32 hyperlipidemic individuals. Cells were either incubated for 5 hours with radiolabeled oleate immediately after isolation or were preincubated for 18 hours in the presence of exogenous cholesterol, and then incubated with ({sup 14}C)sodium-oleate-albumin complex. In the absence of exogenous cholesterol, control and hypercholesterolemic subjects had similarly low values of intracellular cholesterol esterification. In the presence of exogenous cholesterol, both hypertriglyceridemic and hypercholesterolemic subjects had higher cholesterol esterification than controls. There was a significant correlation between the rate of cholesterol esterification and plasma total cholesterol. These results suggest that plasma cholesterol levels may regulate mononuclear cell intra-cellular cholesterol esterification in humans.

  12. Biliary cholesterol secretion : More than a simple ABC

    NARCIS (Netherlands)

    Dikkers, Arne; Tietge, Uwe J. F.

    2010-01-01

    Biliary cholesterol secretion is a process important for 2 major disease complexes, atherosclerotic cardiovascular disease and cholesterol gallstone disease With respect to cardiovascular disease, biliary cholesterol secretion is regarded as the final step for the elimination of cholesterol originat

  13. Fish protein hydrolysates affect cholesterol metabolism in rats fed non-cholesterol and high-cholesterol diets.

    Science.gov (United States)

    Hosomi, Ryota; Fukunaga, Kenji; Arai, Hirofumi; Kanda, Seiji; Nishiyama, Toshimasa; Yoshida, Munehiro

    2012-03-01

    Fish consumption is well known to provide health benefits in both experimental animals and human subjects. Numerous studies have demonstrated the beneficial effects of various protein hydrolysates on lipid metabolism. In this context, this study examined the effect of fish protein hydrolysates (FPH) on cholesterol metabolism compared with the effect of casein. FPHs were prepared from Alaska pollock meat using papain as a protease. Male Wistar rats were divided into the following four dietary groups of seven rats each: either casein (20%) or FPH (10%) + casein (10%), with or without 0.5% cholesterol and 0.1% sodium cholate. Serum and liver lipid levels, fecal cholesterol and bile acid excretions, and the hepatic expression of genes encoding proteins involved in cholesterol homeostasis were examined. In rats fed the FPH diets compared with casein diets with or without cholesterol and sodium cholate, the indexes of cholesterol metabolism-namely, serum cholesterol, triglyceride, and low-density lipoprotein-cholesterol levels-were significantly lower, whereas fecal cholesterol and bile acid excretions were higher. Rats fed the FPH diets compared with casein with cholesterol exhibited a lower liver cholesterol level via an increased liver cholesterol 7α-hydroxylase (CYP7A1) expression level. This study demonstrates that the intake of FPH has hypocholesterolemic effects through the enhancement of fecal cholesterol and bile acid excretions and CYP7A1 expression levels. Therefore, fish peptides prepared by papain digestion might provide health benefits by decreasing the cholesterol content in the blood, which would contribute to the prevention of circulatory system diseases such as arteriosclerosis. PMID:22181072

  14. How cholesterol homeostasis is regulated by plasma membrane cholesterol in excess of phospholipids

    OpenAIRE

    Lange, Yvonne; Ye, Jin; Steck, Theodore L.

    2004-01-01

    How do cells sense and control their cholesterol levels? Whereas most of the cell cholesterol is located in the plasma membrane, the effectors of its abundance are regulated by a small pool of cholesterol in the endoplasmic reticulum (ER). The size of the ER compartment responds rapidly and dramatically to small changes in plasma membrane cholesterol around the normal level. Consequently, increasing plasma membrane cholesterol in vivo from just below to just above the basal level evoked an ac...

  15. Peptide mediators of cholesterol efflux

    Energy Technology Data Exchange (ETDEWEB)

    Bielicki, John K.; Johansson, Jan

    2013-04-09

    The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABAC1 that parallels that of full-length apolipoproteins. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

  16. Epididymis cholesterol homeostasis and sperm fertilizing ability

    Institute of Scientific and Technical Information of China (English)

    Fabrice Saez; Aurélia Ouvrier; Jo(e)l R Drevet

    2011-01-01

    Cholesterol, being the starting point of steroid hormone synthesis, is a long known modulator of both female and male reproductive physiology especially at the level of the gonads and the impact cholesterol has on gametogenesis. Less is known about the effects cholesterol homeostasis may have on postgonadic reproductive functions. Lately, several data have been reported showing how imbalanced cholesterol levels may particularly affect the post-testicular events of sperm maturation that lead to fully fertile male gametes. This review will focus on that aspect and essentially centers on how cholesterol is important for the physiology of the mammalian epididymis and spermatozoa.

  17. Density constrained TDHF

    CERN Document Server

    Oberacker, V E

    2015-01-01

    In this manuscript we provide an outline of the numerical methods used in implementing the density constrained time-dependent Hartree-Fock (DC-TDHF) method and provide a few examples of its application to nuclear fusion. In this approach, dynamic microscopic calculations are carried out on a three-dimensional lattice and there are no adjustable parameters, the only input is the Skyrme effective NN interaction. After a review of the DC-TDHF theory and the numerical methods, we present results for heavy-ion potentials $V(R)$, coordinate-dependent mass parameters $M(R)$, and precompound excitation energies $E^{*}(R)$ for a variety of heavy-ion reactions. Using fusion barrier penetrabilities, we calculate total fusion cross sections $\\sigma(E_\\mathrm{c.m.})$ for reactions between both stable and neutron-rich nuclei. We also determine capture cross sections for hot fusion reactions leading to the formation of superheavy elements.

  18. Constrained space camera assembly

    Science.gov (United States)

    Heckendorn, Frank M.; Anderson, Erin K.; Robinson, Casandra W.; Haynes, Harriet B.

    1999-01-01

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

  19. Endogenous cholesterol synthesis, fecal steroid excretion and serum lanosterol in subjects with high or low response of serum cholesterol to dietary cholesterol

    OpenAIRE

    A. C. Beynen; Katan, M B; Gent, van, H.

    1986-01-01

    In this study we addressed the question whether hypo- and hyper-responders to dietary cholesterol differ with regard to the flexibility of endogenous cholesterol synthesis after changes in cholesterol intake. Whole-body cholesterol synthesis was measured as faecal excretion of neutral steroids and bile acids minus cholesterol intake. In addition, we determined serum concentrations of lanosterol, a precursor of cholesterol and a possible indicator of cholesterol biosynthetic activity. The stud...

  20. Intracellular transport of cholesterol in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Brasaemle, D.L.

    1989-01-01

    The erythrocyte was selected as a simple cell for the study of transbilayer movement of cholesterol. Cholesterol oxidase was used to measure the distribution of ({sup 3}H)cholesterol across the erythrocyte membrane. Cholesterol oxidase was also used to estimate the rate of transport of low density lipoprotein (LDL) cholesterol to the plasma membrane of cultured Chinese hamster ovary (CHO) fibroblasts; the half-time of this process was 42 minutes. The rate of transport of LDL cholesterol to the plasma membrane was confirmed by a second procedure using amphotericin B. Amphotericin B was also used to estimate the rate of transport of endogenously synthesized cholesterol to the plasma membrane of CHO cells. New methodology was developed including improvements of the previously published cholesterol oxidase assay for plasma membrane cholesterol. A new method for detecting transport of cholesterol to the plasma membrane in cultured cells was developed using amphotericin B. Preliminary studies investigated the use of fluorescent polyenes, pimaricin and etruscomycin, as probes for plasma membrane cholesterol in transport studies. Finally, a modification of a previously published cell staining protocol yielded a simple, quantitative assay for cell growth.

  1. Phenolic glycolipid-1 of Mycobacterium leprae binds complement component C3 in serum and mediates phagocytosis by human monocytes

    OpenAIRE

    1991-01-01

    Previous studies from this laboratory have demonstrated that Mycobacterium leprae, an obligate intracellular bacterial parasite, enters human mononuclear phagocytes via complement receptors on these host cells and bacterium-bound C3. The present study investigates the role of M. leprae surface molecules in C3 fixation and phagocytosis. By enzyme-linked immunosorbent assay, C3 binds selectively to phenolic glycolipid-1 (PGL-1), a major surface molecule of the leprosy bacillus. C3 fixation to P...

  2. Production of glycolipid biosurfactants, mannosylerythritol lipids, using sucrose by fungal and yeast strains, and their interfacial properties.

    Science.gov (United States)

    Morita, Tomotake; Ishibashi, Yuko; Fukuoka, Tokuma; Imura, Tomohiro; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2009-10-01

    Glycolipid biosurfactants, mannosylerythritol lipids (MELs), were produced from glucose and sucrose without vegetable oils. Pseudozyma antarctica JCM 10317, Ustilago maydis NBRC 5346, U. scitaminea NBRC 32730, and P. siamensis CBS 9960 produced mainly MEL-A, MEL-A, MEL-B, and MEL-C respectively. The sucrose-derived MELs showed excellent interfacial properties: low critical micelle concentration as well as that of oil-derived MELs. PMID:19809166

  3. Human sperm motility stimulating activity of a sulfono glycolipid isolated from Sri Lankan marine red alga Gelidiella acerosa

    Institute of Scientific and Technical Information of China (English)

    G. A.S. Premakumara; W.D. Ratnasooriya; L.M.V. Tillekeratne; A. S. Amarasekare; Atta-Ur-Rahman

    2001-01-01

    To evaluate the sperm motility stimulating activity of a sulfono glycolipid (S-ACT-l) isolated from Gelidiella acerosa, a Sri Lankan marine red algae. Methods: S-ACT-l, a white amorphous powder was separated from more polar fractions of the hexane soluble of 1:1 CH2Cl2/MeOH extract and subjected to 1H, 1 3C NMR and IR Spectroscopy after reverse phase HPLC for identification. Effects of S-ACT-1 on human sperm motility was assessed in vitro at 10,100 and 1000μg/Ml concentrations at 37℃ for 0, 5, 15, 30 and 60 min. Results: S-ACT-1 was identified as a glycolipid sulfate. The lower dose increased the sperm motility slightly, whilst the medium dose significantly increased the motility ( P < 0.05) from 5 min of incubation reaching a peak at 15 min and the stimulant effect was sustained throughout the experimental period. Furthermore, the medium dose rendered 80% of the immotile viable sperm motile.In contrast, the highest dose impaired the sperm motility. The sperm stimulating activity of S-ACT-1 was dose-depen dent and had a bell-shaped dose response curve for all the 5 incubation periods. Conclusion: S-ACT-1 of Gelidiella acerosa is a Sulfono glycolipid. S-ACT-1 has a potent sperm motility stimulating activity in vitro and has the potential to be developed into a sperm stimulant.

  4. Functions and potential applications of glycolipid biosurfactants--from energy-saving materials to gene delivery carriers.

    Science.gov (United States)

    Kitamoto, Dai; Isoda, Hiroko; Nakahara, Tadaatsu

    2002-01-01

    Biosurfactants (BS) produced by various microorganisms show unique properties (e.g., mild production conditions, lower toxicity, higher biodegradability and environmental compatibility) compared to their chemical counterparts. The numerous advantages of BS have prompted applications not only in the food, cosmetic, and pharmaceutical industries but in environmental protection and energy-saving technology as well. Glycolipid BS are the most promising, due to high productivity from renewable resources and versatile biochemical properties. Mannosylerythritol lipids (MEL), which are glycolipid BS produced by a yeast Candida antarctrica, exhibit not only excellent interfacial properties but also remarkable differentiation-inducing activities against human leukemia cells. MEL also show a potential anti-agglomeration effect on ice particles in ice slurry used for cold thermal storage. Recently, the cationic liposome bearing MEL has been demonstrated to increase dramatically the efficiency of gene transfection into mammalian cells. These features of BS should broaden its applications in new advanced technologies. The current status of research and development on glycolipid BS, especially their function and potential applications, is discussed. PMID:16233292

  5. Specific tumor delivery of paclitaxel using glycolipid-like polymer micelles containing gold nanospheres.

    Science.gov (United States)

    You, Jian; Wang, Zuhua; Du, Yongzhong; Yuan, Hong; Zhang, Peizun; Zhou, Jialin; Liu, Fei; Li, Chun; Hu, Fuqiang

    2013-06-01

    It is difficult for most of the drug delivery systems to really display a temporal and spatial release of entrapped drug once the systems are iv administrated. We hypothesized that the photothermal effect, mediated by a near-infrared (NIR) laser and hollow gold nanospheres (HAuNS), can modulate paclitaxel (PTX) release from polymer micelles, and further result in the enhanced antitumor activity of the micelles. We loaded PTX and HAuNS, which display strong plasmon absorption in the NIR region, into glycolipid-like polymer micelles with an excellent cell internalization capability. The surface of the micelles was conjugated successfully with a peptide, which has the specific-binding with EphB4, a member of the Eph family of receptor tyrosine kinases overexpressed on cell membrane of numerous tumors, to increase the delivery of PTX into tumor cells. Rapid and repetitive drug release from our polymer (HP-TCS) micelles could be readily achieved upon NIR laser irradiation. Our data demonstrated the specific delivery of HP-TCS micelles into positive-EphB4 tumors using a duel-tumor model after iv administration during the whole experiment process (1-48 h). Interestingly, significantly higher uptake of the micelles by SKOV3 tumors (positive-EphB4) than A549 tumors (negtive-EphB4) was observed, with increased ratio on experiment time. However, the specific cell uptake was observed only during the short incubation time (1-4 h) in vitro. Our data also indicated the treatment of tumor cells with the micelles followed by NIR laser irradiation showed significantly greater toxicity activity than the treatment with the micelles alone, free PTX and the micelles (without PTX loading) plus NIR laser irradiation. The enhanced toxicity activity to tumor cells should be attributed to the enhanced drug cellular uptake mediated by the glycolipid-like micelles, chemical toxicity of the released drug from the micelles due to the trigger of NIR laser, and the photothermal ablation under NIR

  6. Identification of Pseudozyma graminicola CBS 10092 as a producer of glycolipid biosurfactants, mannosylerythritol lipids.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Yamamoto, Shuhei; Kitagawa, Masaru; Sogabe, Atsushi; Kitamoto, Dai

    2008-01-01

    A basidiomycetous yeast, Pseudozyma graminicola CBS 10092, was found to accumulate a large amount of glycolipids in the cultured medium when grown on soybean oil as the sole carbon source. Based on thin layer chromatography, the extracellular glycolipids gave spots corresponding to those of mannosylerythritol lipids (MELs), which are highly functional and promising biosurfactants. From the structural characterization by 1H and 13C NMR, the main product was identified as 4-O-[(4'-mono-O-acetyl-2', 3'-di-O-alka(e)noyl)-beta-D-mannopyranosyl]-D-erythritol, which is a highly hydrophilic derivative of MELs known as MEL-C. According to high-performance liquid chromatography analysis, the main product, MEL-C, comprised approximately 85% of all the MELs, and the total amount reached approximately 10 g/L for 7 days. The fatty acids of the present MEL-C consisted of mainly C6, C8 and C14 acids, considerably different from those of MEL-C produced by other Pseudozyma strains such as P. antarctica and P. shanxiensis. The observed critical micelle concentration (CMC) and the surface-tension at CMC of the MEL-C were 4.0 x 10(-6) M and 24.2 mN/m, respectively, while those of MEL-A, the most intensively studied MEL, were 2.7 x 10(-6) M and 28.4 mN/m, respectively. This implied that the MEL-C has higher hydrophilicity than conventional MELs hitherto reported. In addition, on a water-penetration scan, the MEL-C efficiently formed the lamella phase (Lalpha) at a wide range of concentrations, indicating its excellent self-assembling properties. From these results, the newly identified MELs produced by P. graminicola are likely to have great potential for use in oil-in-water type emulsifiers and/or washing detergents, and would thus facilitate a broad range of applications for the promising yeast biosurfactants. PMID:18198469

  7. The Role of Cholesterol in Cancer.

    Science.gov (United States)

    Kuzu, Omer F; Noory, Mohammad A; Robertson, Gavin P

    2016-04-15

    The roles played by cholesterol in cancer development and the potential of therapeutically targeting cholesterol homeostasis is a controversial area in the cancer community. Several epidemiologic studies report an association between cancer and serum cholesterol levels or statin use, while others suggest that there is not one. Furthermore, the Cancer Genome Atlas (TCGA) project using next-generation sequencing has profiled the mutational status and expression levels of all the genes in diverse cancers, including those involved in cholesterol metabolism, providing correlative support for a role of the cholesterol pathway in cancer development. Finally, preclinical studies tend to more consistently support the role of cholesterol in cancer, with several demonstrating that cholesterol homeostasis genes can modulate development. Because of space limitations, this review provides selected examples of the epidemiologic, TCGA, and preclinical data, focusing on alterations in cholesterol homeostasis and its consequent effect on patient survival. In melanoma, this focused analysis demonstrated that enhanced expression of cholesterol synthesis genes was associated with decreased patient survival. Collectively, the studies in melanoma and other cancer types suggested a potential role of disrupted cholesterol homeostasis in cancer development but additional studies are needed to link population-based epidemiological data, the TCGA database results, and preclinical mechanistic evidence to concretely resolve this controversy. Cancer Res; 76(8); 2063-70. ©2016 AACR. PMID:27197250

  8. Early Cosmology Constrained

    CERN Document Server

    Verde, Licia; Pigozzo, Cassio; Heavens, Alan F; Jimenez, Raul

    2016-01-01

    We investigate our knowledge of early universe cosmology by exploring how much additional energy density can be placed in different components beyond those in the $\\Lambda$CDM model. To do this we use a method to separate early- and late-universe information enclosed in observational data, thus markedly reducing the model-dependency of the conclusions. We find that the 95\\% credibility regions for extra energy components of the early universe at recombination are: non-accelerating additional fluid density parameter $\\Omega_{\\rm MR} < 0.006$ and extra radiation parameterised as extra effective neutrino species $2.3 < N_{\\rm eff} < 3.2$ when imposing flatness. Our constraints thus show that even when analyzing the data in this largely model-independent way, the possibility of hiding extra energy components beyond $\\Lambda$CDM in the early universe is seriously constrained by current observations. We also find that the standard ruler, the sound horizon at radiation drag, can be well determined in a way ...

  9. Swelling of Bicontinuous Cubic Phases in Guerbet Glycolipid: Effects of Additives.

    Science.gov (United States)

    Salim, Malinda; Wan Iskandar, Wan Farah Nasuha; Patrick, Melonney; Zahid, N Idayu; Hashim, Rauzah

    2016-06-01

    Inverse bicontinuous cubic phases of lyotropic liquid crystal self-assembly have received much attention in biomedical, biosensing, and nanotechnology applications. An Ia3d bicontinuous cubic based on the gyroid G-surface can be formed by the Guerbet synthetic glucolipid 2-hexyl-decyl-β-d-glucopyranoside (β-Glc-OC6C10) in excess water. The small water channel diameter of this cubic phase could provide nanoscale constraints in encapsulation of large molecules and crystallization of membrane proteins, hence stresses the importance of water channel tuning ability. This work investigates the swelling behavior of lyotropic self-assembly of β-Glc-OC6C10 which could be controlled and modulated by different surfactants as a hydration-modulating agent. Our results demonstrate that addition of nonionic glycolipid octyl-β-d-glucopyranoside (β-Glc-OC8) at 20 and 25 mol % gives the largest attainable cubic water channel diameter of ca. 62 Å, and formation of coacervates which may be attributed to a sponge phase were seen at 20 mol % octyl-β-d-maltopyranoside (β-Mal-OC8). Swelling of the cubic water channel can also be attained in charged surfactant-doped systems dioctyl sodium sulfosuccinate (AOT) and hexadecyltrimethylammonium bromide (CTAB), of which phase transition occurred from cubic to a lamellar phase. Destabilization of the cubic phase to an inverse hexagonal phase was observed when a high amount of charged lecithin (LEC) and stearylamine (SA) was added to the lipid self-assembly. PMID:27183393

  10. Characterization of the genus Pseudozyma by the formation of glycolipid biosurfactants, mannosylerythritol lipids.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Hiroko K; Kitamoto, Dai

    2007-03-01

    Pseudozyma antarctica is one of the best producers of the glycolipid biosurfactants known as mannosylerythritol lipids (MELs), which show not only excellent surface-active properties but also versatile biochemical actions. In order to obtain a variety of producers, all the species of the genus were examined for their production of MELs from soybean oil. Pseudozyma fusiformata, P. parantarctica and P. tsukubaensis were newly identified to be MEL producers. Of the strains tested, P. parantarctica gave the best yield of MELs (30 g L(-1)). The obtained yield corresponded to those of P. antarctica, P. aphidis and P. rugulosa, which are known high-level MEL producers. Interestingly, P. parantarctica and P. fusiformata produced mainly 4-O-[(4',6'-di-O-acetyl-2',3'-di-O-alkanoyl)-beta-d-mannopyranosyl]-meso-erythritol (MEL-A), whereas P. tsukubaensis produced mainly 4-O-[(6'-mono-O-acetyl-2',3'-di-O-alkanoyl)-beta-d-mannopyranosyl]-meso-erythritol (MEL-B). Consequently, six of the nine species clearly produced MELs. Based on the MEL production pattern, the nine species seemed to fall into four groups: the first group produces large amounts of MELs; the second produces both MELs and other biosurfactants; the third mainly produces MEL-B; and the fourth is non-MEL-producing. Thus, MEL production may be an important taxonomic index for the Pseudozyma yeasts. PMID:17328742

  11. Activation of fibroblast and papilla cells by glycolipid biosurfactants, mannosylerythritol lipids.

    Science.gov (United States)

    Morita, Tomotake; Kitagawa, Masaru; Yamamoto, Shuhei; Suzuki, Michiko; Sogabe, Atsushi; Imura, Tomohiro; Fukuoka, Tokuma; Kitamoto, Dai

    2010-01-01

    Mannosylerythritol lipids (MELs), the extracellular glycolipids produced from feedstock by yeasts belonging to the genus Pseudozyma, are the most promising biosurfactants known due to its versatile interfacial and biochemical actions. In order to broaden the application in cosmetics, the cell activating property of MELs was investigated using cultured fibroblast and papilla cells, and a three-dimensional cultured human skin model. The di-acetylated MEL (MEL-A) produced from soybean oil significantly increased the viability of the fibroblast cells over 150% compared with that of control cells. On the other hand, no cell activation was observed by the treatment with MEL-A produced from olive oil. The mono-acetylated MEL (MEL-B) hardly increased the cell viability. The viability of the fibroblast cells decreased with the addition of more than 1 microg/L of MELs, whereas the cultured human skin cells showed high viability with 5 microg/L of MELs. Interestingly, the papilla cells were dramatically activated with 0.001 microg/L of MEL-A produced from soybean oil: the cell viability reached at 150% compared with that of control cells. Consequently, the present MEL-A produced from soybean oil should have a potential as a new hair growth agent stimulating the papilla cells. PMID:20625237

  12. Lipidomic Approaches towards Deciphering Glycolipids from Microalgae as a Reservoir of Bioactive Lipids

    Directory of Open Access Journals (Sweden)

    Elisabete da Costa

    2016-05-01

    Full Text Available In recent years, noteworthy research has been performed around lipids from microalgae. Among lipids, glycolipids (GLs are quite abundant in microalgae and are considered an important source of fatty acids (FAs. GLs are rich in 16- and 18-carbon saturated and unsaturated fatty acids and often contain polyunsaturated fatty acids (PUFAs like n-3 α-linolenic (ALA 18:3, eicosapentaenoic (EPA, 20:5 and docosahexaenoic (DHA, 22:6. GLs comprise three major classes: monogalactosyldiacyl glycerolipids (MGDGs, digalactosyl diacylglycerolipids (DGDGs and sulfoquinovosyl diacylglycerolipids (SQDGs, whose composition in FA directly depends on the growth conditions. Some of these lipids are high value-added compounds with antitumoral, antimicrobial and anti-inflammatory activities and also with important nutritional significance. To fully explore GLs’ bioactive properties it is necessary to fully characterize their structure and to understand the relation between the structure and their biological properties, which can be addressed using modern mass spectrometry (MS-based lipidomic approaches. This review will focus on the up-to-date FA composition of GLs identified by MS-based lipidomics and their potential as phytochemicals.

  13. Glycolipid-based TLR4 Modulators and Fluorescent Probes: Rational Design, Synthesis, and Biological Properties.

    Science.gov (United States)

    Ciaramelli, Carlotta; Calabrese, Valentina; Sestito, Stefania E; Pérez-Regidor, Lucia; Klett, Javier; Oblak, Alja; Jerala, Roman; Piazza, Matteo; Martín-Santamaría, Sonsoles; Peri, Francesco

    2016-08-01

    The cationic glycolipid IAXO-102, a potent TLR4 antagonist targeting both MD-2 and CD14 co-receptors, has been used as scaffold to design new potential TLR4 modulators and fluorescent labels for the TLR4 receptor complex (membrane TLR4.MD-2 dimer and CD14). The primary amino group of IAXO-102, not involved in direct interaction with MD-2 and CD14 receptors, has been exploited to covalently attach a fluorescein (molecules 1 and 2) or to link two molecules of IAXO-102 through diamine and diammonium spacers, obtaining 'dimeric' molecules 3 and 4. The structure-based rational design of compounds 1-4 was guided by the optimization of MD-2 and CD14 binding. Compounds 1 and 2 inhibited TLR4 activation, in a concentration-dependent manner, and signaling in HEK-Blue TLR4 cells. The fluorescent labeling of murine macrophages by molecule 1 was inhibited by LPS and was also abrogated when cell surface proteins were digested by trypsin, thus suggesting an interaction of fluorescent probe 1 with membrane proteins of the TLR4 receptor system.

  14. Mycoplasma fermentans glycolipid-antigen as a pathogen of rheumatoid arthritis

    International Nuclear Information System (INIS)

    Mycoplasma fermentans has been suspected as one of the causative pathogenic microorganisms of rheumatoid arthritis (RA) however, the pathogenic mechanism is still unclear. We, previously, reported that glycolipid-antigens (GGPL-I and III) are the major antigens of M. fermentans. Monoclonal antibody against the GGPL-III could detect the existence of the GGPL-III antigens in synovial tissues from RA patients. GGPL-III antigens were detected in 38.1% (32/84) of RA patient's tissues, but not in osteoarthritis (OA) and normal synovial tissues. Immunoelectron microscopy revealed that a part of GGPL-III antigens are located at endoplasmic reticulum. GGPL-III significantly induced TNF-α and IL-6 production from peripheral blood mononulear cells, and also proliferation of synovial fibroblasts. Further study is necessary to prove that M. fermentans is a causative microorganism of RA; however, the new mechanisms of disease pathogenesis provides hope for the development of effective and safe immunotherapeutic strategies based on the lipid-antigen, GGPL-III, in the near future

  15. Constraining neutrinoless double beta decay

    International Nuclear Information System (INIS)

    A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude.

  16. Phase I study to evaluate toxicity and feasibility of intratumoral injection of α-gal glycolipids in patients with advanced melanoma.

    Science.gov (United States)

    Albertini, Mark R; Ranheim, Erik A; Zuleger, Cindy L; Sondel, Paul M; Hank, Jacquelyn A; Bridges, Alan; Newton, Michael A; McFarland, Thomas; Collins, Jennifer; Clements, Erin; Henry, Mary Beth; Neuman, Heather B; Weber, Sharon; Whalen, Giles; Galili, Uri

    2016-08-01

    Effective uptake of tumor cell-derived antigens by antigen-presenting cells is achieved pre-clinically by in situ labeling of tumor with α-gal glycolipids that bind the naturally occurring anti-Gal antibody. We evaluated toxicity and feasibility of intratumoral injections of α-gal glycolipids as an autologous tumor antigen-targeted immunotherapy in melanoma patients (pts). Pts with unresectable metastatic melanoma, at least one cutaneous, subcutaneous, or palpable lymph node metastasis, and serum anti-Gal titer ≥1:50 were eligible for two intratumoral α-gal glycolipid injections given 4 weeks apart (cohort I: 0.1 mg/injection; cohort II: 1.0 mg/injection; cohort III: 10 mg/injection). Monitoring included blood for clinical, autoimmune, and immunological analyses and core tumor biopsies. Treatment outcome was determined 8 weeks after the first α-gal glycolipid injection. Nine pts received two intratumoral injections of α-gal glycolipids (3 pts/cohort). Injection-site toxicity was mild, and no systemic toxicity or autoimmunity could be attributed to the therapy. Two pts had stable disease by RECIST lasting 8 and 7 months. Tumor nodule biopsies revealed minimal to no change in inflammatory infiltrate between pre- and post-treatment biopsies except for 1 pt (cohort III) with a post-treatment inflammatory infiltrate. Two and four weeks post-injection, treated nodules in 5 of 9 pts exhibited tumor cell necrosis without neutrophilic or lymphocytic inflammatory response. Non-treated tumor nodules in 2 of 4 evaluable pts also showed necrosis. Repeated intratumoral injections of α-gal glycolipids are well tolerated, and tumor necrosis was seen in some tumor nodule biopsies after tumor injection with α-gal glycolipids. PMID:27207605

  17. Toxin A from Clostridium difficile binds to rabbit erythrocyte glycolipids with terminal Gal alpha 1-3Gal beta 1-4GlcNAc sequences

    International Nuclear Information System (INIS)

    The binding of Toxin A isolated from Clostridium difficile to rabbit erythrocyte glycolipids has been studied. Total lipid extracts from rabbit erythrocytes were subjected to thin-layer chromatography and toxin-binding glycolipids detected by using 125I-labeled Toxin A in a direct binding overlay technique. Two major and several minor toxin-binding glycolipids were detected in rabbit erythrocytes by this method. The results of structural analyses of the major toxin-binding glycolipids were consistent with a pentasaccharide-ceramide (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer) and a branched decasaccharide-ceramide (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3[Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-6]Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer) previously identified as the two most abundant glycolipids in rabbit erythrocytes. 125I-Toxin A binding to these glycolipids could be inhibited by bovine thyroglobulin, monospecific antiserum to the toxin, or by treatment of the glycolipids with alpha-galactosidase. The absence of toxin interaction with isoglobotriaosylceramide (Gal alpha 1-3Gal beta 1-4Glc-Cer) isolated from canine intestine suggested that the GlcNAc residue present in the terminal Gal alpha 1-3Gal beta 1-4GLcNAc sequence common to all known toxin binding glycoconjugates is required for carbohydrate-specific recognition by Toxin A. These observations are consistent with the proposed carbohydrate binding specificity of Toxin A for the nonreducing terminal sequence, Gal alpha 1-3Gal beta 1-4GlcNAc

  18. Toxin A from Clostridium difficile binds to rabbit erythrocyte glycolipids with terminal Gal alpha 1-3Gal beta 1-4GlcNAc sequences

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.F.; Krivan, H.C.; Wilkins, T.D.; Smith, D.F.

    1987-08-15

    The binding of Toxin A isolated from Clostridium difficile to rabbit erythrocyte glycolipids has been studied. Total lipid extracts from rabbit erythrocytes were subjected to thin-layer chromatography and toxin-binding glycolipids detected by using /sup 125/I-labeled Toxin A in a direct binding overlay technique. Two major and several minor toxin-binding glycolipids were detected in rabbit erythrocytes by this method. The results of structural analyses of the major toxin-binding glycolipids were consistent with a pentasaccharide-ceramide (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer) and a branched decasaccharide-ceramide (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3(Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-6)Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-Cer) previously identified as the two most abundant glycolipids in rabbit erythrocytes. /sup 125/I-Toxin A binding to these glycolipids could be inhibited by bovine thyroglobulin, monospecific antiserum to the toxin, or by treatment of the glycolipids with alpha-galactosidase. The absence of toxin interaction with isoglobotriaosylceramide (Gal alpha 1-3Gal beta 1-4Glc-Cer) isolated from canine intestine suggested that the GlcNAc residue present in the terminal Gal alpha 1-3Gal beta 1-4GLcNAc sequence common to all known toxin binding glycoconjugates is required for carbohydrate-specific recognition by Toxin A. These observations are consistent with the proposed carbohydrate binding specificity of Toxin A for the nonreducing terminal sequence, Gal alpha 1-3Gal beta 1-4GlcNAc.

  19. Power-constrained supercomputing

    Science.gov (United States)

    Bailey, Peter E.

    As we approach exascale systems, power is turning from an optimization goal to a critical operating constraint. With power bounds imposed by both stakeholders and the limitations of existing infrastructure, achieving practical exascale computing will therefore rely on optimizing performance subject to a power constraint. However, this requirement should not add to the burden of application developers; optimizing the runtime environment given restricted power will primarily be the job of high-performance system software. In this dissertation, we explore this area and develop new techniques that extract maximum performance subject to a particular power constraint. These techniques include a method to find theoretical optimal performance, a runtime system that shifts power in real time to improve performance, and a node-level prediction model for selecting power-efficient operating points. We use a linear programming (LP) formulation to optimize application schedules under various power constraints, where a schedule consists of a DVFS state and number of OpenMP threads for each section of computation between consecutive message passing events. We also provide a more flexible mixed integer-linear (ILP) formulation and show that the resulting schedules closely match schedules from the LP formulation. Across four applications, we use our LP-derived upper bounds to show that current approaches trail optimal, power-constrained performance by up to 41%. This demonstrates limitations of current systems, and our LP formulation provides future optimization approaches with a quantitative optimization target. We also introduce Conductor, a run-time system that intelligently distributes available power to nodes and cores to improve performance. The key techniques used are configuration space exploration and adaptive power balancing. Configuration exploration dynamically selects the optimal thread concurrency level and DVFS state subject to a hardware-enforced power bound

  20. Biliary cholesterol secretion: More than a simple ABC

    Institute of Scientific and Technical Information of China (English)

    Arne; Dikkers; Uwe; JF; Tietge

    2010-01-01

    Biliary cholesterol secretion is a process important for 2 major disease complexes, atherosclerotic cardiovascular disease and cholesterol gallstone disease. With respect to cardiovascular disease, biliary cholesterol secretion is regarded as the f inal step for the elimination of cholesterol originating from cholesterol-laden macrophage foam cells in the vessel wall in a pathway named reverse cholesterol transport. On the other hand, cholesterol hypersecretion into the bile is considered the main pathophys...

  1. Raising HDL cholesterol in women

    Directory of Open Access Journals (Sweden)

    Danny J Eapen

    2009-11-01

    Full Text Available Danny J Eapen1, Girish L Kalra1, Luay Rifai1, Christina A Eapen2, Nadya Merchant1, Bobby V Khan11Emory University School of Medicine, Atlanta, GA, USA; 2University of South Florida School of Medicine, Tampa, FL, USAAbstract: High-density lipoprotein cholesterol (HDL-C concentration is essential in the determination of coronary heart disease (CHD risk in women. This is especially true in the postmenopausal state, where lipid profiles and CHD risk mimic that of age-matched men. Thus, interventions designed to reduce CHD risk by raising HDL-C levels may have particular significance during the transition to menopause. This review discusses HDL-C-raising therapies and the role of HDL in the primary prevention of CHD in women. Lifestyle-based interventions such as dietary change, aerobic exercise regimens, and smoking cessation are initial steps that are effective in raising HDL-C, and available data suggest women respond similarly to men with these interventions. When combined with pharmacotherapy, the effects of these lifestyle alterations are further amplified. Though studies demonstrating gender-specific differences in therapy are limited, niacin continues to be the most effective agent in raising HDL-C levels, especially when used in combination with fibrate or statin therapy. Emerging treatments such as HDL mimetic therapy show much promise in further raising HDL-C levels and improving cardiovascular outcomes.Keywords: high-density lipoprotein, HDL, women, cholesterol, heart disease

  2. Structure of Cholesterol in Lipid Rafts

    Science.gov (United States)

    Toppozini, Laura; Meinhardt, Sebastian; Armstrong, Clare L.; Yamani, Zahra; Kučerka, Norbert; Schmid, Friederike; Rheinstädter, Maikel C.

    2014-11-01

    Rafts, or functional domains, are transient nano-or mesoscopic structures in the plasma membrane and are thought to be essential for many cellular processes such as signal transduction, adhesion, trafficking, and lipid or protein sorting. Observations of these membrane heterogeneities have proven challenging, as they are thought to be both small and short lived. With a combination of coarse-grained molecular dynamics simulations and neutron diffraction using deuterium labeled cholesterol molecules, we observe raftlike structures and determine the ordering of the cholesterol molecules in binary cholesterol-containing lipid membranes. From coarse-grained computer simulations, heterogenous membranes structures were observed and characterized as small, ordered domains. Neutron diffraction was used to study the lateral structure of the cholesterol molecules. We find pairs of strongly bound cholesterol molecules in the liquid-disordered phase, in accordance with the umbrella model. Bragg peaks corresponding to ordering of the cholesterol molecules in the raftlike structures were observed and indexed by two different structures: a monoclinic structure of ordered cholesterol pairs of alternating direction in equilibrium with cholesterol plaques, i.e., triclinic cholesterol bilayers.

  3. Black pepper and piperine reduce cholesterol uptake and enhance translocation of cholesterol transporter proteins.

    Science.gov (United States)

    Duangjai, Acharaporn; Ingkaninan, Kornkanok; Praputbut, Sakonwun; Limpeanchob, Nanteetip

    2013-04-01

    Black pepper (Piper nigrum L.) lowers blood lipids in vivo and inhibits cholesterol uptake in vitro, and piperine may mediate these effects. To test this, the present study aimed to compare actions of black pepper extract and piperine on (1) cholesterol uptake and efflux in Caco-2 cells, (2) the membrane/cytosol distribution of cholesterol transport proteins in these cells, and (3) the physicochemical properties of cholesterol micelles. Piperine or black pepper extract (containing the same amount of piperine) dose-dependently reduced cholesterol uptake into Caco-2 cells in a similar manner. Both preparations reduced the membrane levels of NPC1L1 and SR-BI proteins but not their overall cellular expression. Micellar cholesterol solubility of lipid micelles was unaffected except by 1 mg/mL concentration of black pepper extract. These data suggest that piperine is the active compound in black pepper and reduces cholesterol uptake by internalizing the cholesterol transporter proteins.

  4. Potential of BODIPY-cholesterol for analysis of cholesterol transport and diffusion in living cells

    DEFF Research Database (Denmark)

    Wüstner, Daniel; Lund, Frederik Wendelboe; Röhrl, Clemens;

    2016-01-01

    Cholesterol is an abundant and important lipid component of cellular membranes. Analysis of cholesterol transport and diffusion in living cells is hampered by the technical challenge of designing suitable cholesterol probes which can be detected for example by optical microscopy. One strategy...... is to use intrinsically fluorescent sterols, as dehydroergosterol (DHE), having minimal chemical alteration compared to cholesterol but giving low fluorescence signals in the UV region of the spectrum. Alternatively, one can use dye-tagged cholesterol analogs and in particular BODIPY-cholesterol (BChol......), whose synthesis and initial characterization was pioneered by Robert Bittman. Here, we give a general overview of the properties and applications but also limitations of BODIPY-tagged cholesterol probes for analyzing intracellular cholesterol trafficking. We describe our own experiences...

  5. Intracellular cholesterol-binding proteins enhance HDL-mediated cholesterol uptake in cultured primary mouse hepatocytes

    OpenAIRE

    Storey, Stephen M.; McIntosh, Avery L.; Huang, Huan; Landrock, Kerstin K.; Martin, Gregory G.; Landrock, Danilo; Payne, H. Ross; Atshaves, Barbara P.; Kier, Ann B.; Schroeder, Friedhelm

    2012-01-01

    A major gap in our knowledge of rapid hepatic HDL cholesterol clearance is the role of key intracellular factors that influence this process. Although the reverse cholesterol transport pathway targets HDL to the liver for net elimination of free cholesterol from the body, molecular details governing cholesterol uptake into hepatocytes are not completely understood. Therefore, the effects of sterol carrier protein (SCP)-2 and liver fatty acid-binding protein (L-FABP), high-af...

  6. Oxidised LDL, HDL cholesterol, LDL cholesterol levels in patients of coronary artery disease

    OpenAIRE

    Ghosh, Joya; T K Mishra; Rao, Y. N.; Aggarwal, S. K.

    2006-01-01

    Coronary artery disease is a major cause of morbidity and has various risk factors. Lipid profile i.e. low HDL-cholesterol, high LDL cholesterol, high total cholesterol, high triglycerides playing important role in its causation. Recently interest has been shown in the oxidized fraction of LDL as one of the risk factors. In the present study 60 age and sex matched normal healthy individuals were taken as controls and 60 patients of CAD were taken. Cholesterol was measured by enzymatic method,...

  7. Mast Cells and HDL Studies on Cholesterol Efflux and Reverse Cholesterol Transport

    OpenAIRE

    Kareinen, Ilona

    2015-01-01

    Atherosclerosis is an inflammatory disease characterized by the accumulation of cholesterol in the arterial intima and consequently the formation of atherosclerotic plaques. Formation of these plaques is initiated by the appearance of macrophage foam cell in the arterial intima. Foam cells are formed as excessive cholesterol accumulates in the cytosol of macrophages and finally the net influx exceeds the efflux of cholesterol. Excessive accumulation of chemically modified cholesterol in foam ...

  8. Dietary cholesterol and fats at a young age : do they influence cholesterol metabolism in adult life?

    NARCIS (Netherlands)

    Temmerman, A M; Vonk, R J; Niezen-Koning, K; Berger, R.; Fernandes, J

    1989-01-01

    The effects of dietary cholesterol and fats on cholesterol metabolism later in life were studied in Mongolian gerbils. Three groups were given a basic diet with soybean oil, palm kernel oil amounting to 8.75% (w/w), or the basic diet only. In three other groups, cholesterol (0.05%) was added to the

  9. From blood to gut : Direct secretion of cholesterol via transintestinal cholesterol efflux

    NARCIS (Netherlands)

    Vrins, Carlos L. J.

    2010-01-01

    The reverse cholesterol transport pathway (RCT) is the focus of many cholesterol lowering therapies By way of this pathway, excess cholesterol is collected from peripheral tissues and delivered back to the liver and gastrointestinal tract for excretion from the body For a long time this removal via

  10. Statins increase hepatic cholesterol synthesis and stimulate fecal cholesterol elimination in mice

    NARCIS (Netherlands)

    Schonewille, Marleen; de Boer, Jan Freark; Mele, Laura; Wolters, Henk; Bloks, Vincent W; Wolters, Justina C; Kuivenhoven, Jan Albert; Tietge, Uwe J.F.; Brufau Dones, Gemma; Groen, Albert K

    2016-01-01

    Statins are competitive inhibitors of HMG-CoA reductase, the rate-limiting enzyme of cholesterol synthesis. Statins reduce plasma cholesterol levels, but whether this is actually caused by inhibition of de novo cholesterol synthesis has not been clearly established. Using three different statins we

  11. Production of glycolipidic bio surfactants by environment bacteria: diversity and physiological part; Production de biosurfactants glycolipidiques par les bacteries de l`environnement: diversite et role physiologique

    Energy Technology Data Exchange (ETDEWEB)

    Arino, S.

    1996-10-09

    About a hundred bacterial strains, isolated from soils, polluted or not by hydrocarbons, were tested for their capacity to excrete glycosides. The biggest productions were obtained for a soluble carbon source (glycerol) in a culture medium limited in the nitrogen source. In these conditions, 18 g/l of rhamnose lipids were produced by train Pseudomonas aeruginosa GL1 in a 200 h culture. Pseudomonas aeruginosa GL1, Cellulomonas celulans SA43 and Rhodococcus erythropolis DSM 43060 were studied in detail. The bio-surfactants produced were identified respectively as rhamnose lipids, oligosaccharide lipids and trehalose lipids, using various original analytical methods. Sugars and fatty acids composing these glycolipids had been shown to be usual components of the outer part of the cell wall in these microbial species. Moreover, cell hydrophobicity of the producing bacteria varied in time during culture. These results showed that both the cell wall and the extracellular glycolipids take part in the process of hydrocarbon uptake in the polluted environments. As other bacteria of the same species from different origins present the same characteristics, it may be concluded that glycolipid excretion does not constitute a specific response for hydrocarbon assimilation. In fact, a more general physiological role of glycolipids, concerning modifications of hydrophobic interfaces between the producing bacteria and their surrounding environment, could explain the production of glycolipids, and could also be utilized in hydrocarbon uptake. (author)

  12. Structural Characterization and Anti-HSV-1 and HSV-2 Activity of Glycolipids from the Marine Algae Osmundaria obtusiloba Isolated from Southeastern Brazilian Coast

    Directory of Open Access Journals (Sweden)

    Lauro M. de Souza

    2012-04-01

    Full Text Available Glycolipids were extracted from the red alga Osmundaria obtusiloba from Southeastern Brazilian coast. The acetone insoluble material was extracted with chloroform/methanol and the lipids, enriched in glycolipids, were fractionated on a silica gel column eluted with chloroform, acetone and then methanol. Three major orcinol-positive bands were found in the acetone and methanol fractions, being detected by thin layer chromatography. The structures of the corresponding glycolipids were elucidated by ESI-MS and 1H/13C NMR analysis, on the basis of their tandem-MS behavior and HSQC, TOCSY fingerprints. For the first time, the structure of sulfoquinovosyldiacylglycerol from the red alga Osmundaria obtusiloba was characterized. This molecule exhibited potent antiviral activity against HSV-1 and HSV-2 with EC50 values of 42 µg/mL to HSV-1 and 12 µg/mL to HSV-2, respectively. Two other glycolipids, mono- and digalactosyldiacylglycerol, were also found in the alga, being characterized by ESI-MS/MS. The structural elucidation of algae glycolipids is a first step for a better understanding of the relation between these structures and their biological activities.

  13. Structural Characterization and Anti-HSV-1 and HSV-2 Activity of Glycolipids from the Marine Algae Osmundaria obtusiloba Isolated from Southeastern Brazilian Coast

    Directory of Open Access Journals (Sweden)

    Eliana Barreto-Bergter

    2012-04-01

    Full Text Available Glycolipids were extracted from the red alga Osmundaria obtusiloba from Southeastern Brazilian coast. The acetone insoluble material was extracted with chloroform/methanol and the lipids, enriched in glycolipids, were fractionated on a silica gel column eluted with chloroform, acetone and then methanol. Three major orcinol-positive bands were found in the acetone and methanol fractions, being detected by thin layer chromatography. The structures of the corresponding glycolipids were elucidated by ESI-MS and 1H/13C NMR analysis, on the basis of their tandem-MS behavior and HSQC, TOCSY fingerprints. For the first time, the structure of sulfoquinovosyldiacylglycerol from the red alga Osmundaria obtusiloba was characterized. This molecule exhibited potent antiviral activity against HSV-1 and HSV-2 with EC50 values of 42 µg/mL to HSV-1 and 12 µg/mL to HSV-2, respectively. Two other glycolipids, mono- and digalactosyldiacylglycerol, were also found in the alga, being characterized by ESI-MS/MS. The structural elucidation of algae glycolipids is a first step for a better understanding of the relation between these structures and their biological activities.

  14. Genome and transcriptome analysis of the basidiomycetous yeast Pseudozyma antarctica producing extracellular glycolipids, mannosylerythritol lipids.

    Directory of Open Access Journals (Sweden)

    Tomotake Morita

    Full Text Available Pseudozyma antarctica is a non-pathogenic phyllosphere yeast known as an excellent producer of mannosylerythritol lipids (MELs, multi-functional extracellular glycolipids, from vegetable oils. To clarify the genetic characteristics of P. antarctica, we analyzed the 18 Mb genome of P. antarctica T-34. On the basis of KOG analysis, the number of genes (219 genes categorized into lipid transport and metabolism classification in P. antarctica was one and a half times larger than that of yeast Saccharomyces cerevisiae (140 genes. The gene encoding an ATP/citrate lyase (ACL related to acetyl-CoA synthesis conserved in oleaginous strains was found in P. antarctica genome: the single ACL gene possesses the four domains identical to that of the human gene, whereas the other oleaginous ascomycetous species have the two genes covering the four domains. P. antarctica genome exhibited a remarkable degree of synteny to U. maydis genome, however, the comparison of the gene expression profiles under the culture on the two carbon sources, glucose and soybean oil, by the DNA microarray method revealed that transcriptomes between the two species were significantly different. In P. antarctica, expression of the gene sets relating fatty acid metabolism were markedly up-regulated under the oily conditions compared with glucose. Additionally, MEL biosynthesis cluster of P. antarctica was highly expressed regardless of the carbon source as compared to U. maydis. These results strongly indicate that P. antarctica has an oleaginous nature which is relevant to its non-pathogenic and MEL-overproducing characteristics. The analysis and dataset contribute to stimulate the development of improved strains with customized properties for high yield production of functional bio-based materials.

  15. Genome and transcriptome analysis of the basidiomycetous yeast Pseudozyma antarctica producing extracellular glycolipids, mannosylerythritol lipids.

    Science.gov (United States)

    Morita, Tomotake; Koike, Hideaki; Hagiwara, Hiroko; Ito, Emi; Machida, Masayuki; Sato, Shun; Habe, Hiroshi; Kitamoto, Dai

    2014-01-01

    Pseudozyma antarctica is a non-pathogenic phyllosphere yeast known as an excellent producer of mannosylerythritol lipids (MELs), multi-functional extracellular glycolipids, from vegetable oils. To clarify the genetic characteristics of P. antarctica, we analyzed the 18 Mb genome of P. antarctica T-34. On the basis of KOG analysis, the number of genes (219 genes) categorized into lipid transport and metabolism classification in P. antarctica was one and a half times larger than that of yeast Saccharomyces cerevisiae (140 genes). The gene encoding an ATP/citrate lyase (ACL) related to acetyl-CoA synthesis conserved in oleaginous strains was found in P. antarctica genome: the single ACL gene possesses the four domains identical to that of the human gene, whereas the other oleaginous ascomycetous species have the two genes covering the four domains. P. antarctica genome exhibited a remarkable degree of synteny to U. maydis genome, however, the comparison of the gene expression profiles under the culture on the two carbon sources, glucose and soybean oil, by the DNA microarray method revealed that transcriptomes between the two species were significantly different. In P. antarctica, expression of the gene sets relating fatty acid metabolism were markedly up-regulated under the oily conditions compared with glucose. Additionally, MEL biosynthesis cluster of P. antarctica was highly expressed regardless of the carbon source as compared to U. maydis. These results strongly indicate that P. antarctica has an oleaginous nature which is relevant to its non-pathogenic and MEL-overproducing characteristics. The analysis and dataset contribute to stimulate the development of improved strains with customized properties for high yield production of functional bio-based materials. PMID:24586250

  16. Direct xylan conversion into glycolipid biosurfactants, mannosylerythritol lipids, by Pseudozyma antarctica PYCC 5048(T).

    Science.gov (United States)

    Faria, Nuno Torres; Marques, Susana; Fonseca, César; Ferreira, Frederico Castelo

    2015-04-01

    Mannosylerythritol lipids (MEL) are glycolipid biosurfactants, produced by Pseudozyma spp., with increasing commercial interest. While MEL can be produced from d-glucose and d-xylose, the direct conversion of the respective lignocellulosic polysaccharides, cellulose and xylan, was not reported yet. The ability of Pseudozyma antarctica PYCC 5048(T) and Pseudozyma aphidis PYCC 5535(T) to use cellulose (Avicel(®)) and xylan (beechwood) as carbon and energy source has been assessed along with their capacity of producing cellulolytic and hemicellulolytic enzymes, toward a consolidated bioprocess (CBP) for MEL production. The yeasts assessed were neither able to grow in medium containing Avicel(®) nor produce cellulolytic enzymes under the conditions tested. On contrary, both yeasts were able to efficiently grow in xylan, but MEL production was only detected in P. antarctica PYCC 5048(T) cultures. MEL titers reached 1.3g/l after 10 days in batch cultures with 40g/l xylan, and 2.0g/l in fed-batch cultures with xylan feeding (additional 40g/l) at day 4. High levels of xylanase activities were detected in xylan cultures, reaching 47-62U/ml (31-32U/mg) at 50°C, and still exhibiting more than 10U/ml under physiological temperature (28°C). Total β-xylosidase activities, displayed mainly as wall-bounded and extracellular activity, accounted for 0.154 and 0.176U/ml in P. antarctica PYCC 5048(T) and P. aphidis PYCC 5535(T) cultures, respectively. The present results demonstrate the potential of Pseudozyma spp. for using directly a fraction of lignocellulosic biomass, xylan, and combining in the same bioprocess the production of xylanolytic enzymes with MEL production. PMID:25765311

  17. Animal ice-binding (antifreeze) proteins and glycolipids: an overview with emphasis on physiological function.

    Science.gov (United States)

    Duman, John G

    2015-06-01

    Ice-binding proteins (IBPs) assist in subzero tolerance of multiple cold-tolerant organisms: animals, plants, fungi, bacteria etc. IBPs include: (1) antifreeze proteins (AFPs) with high thermal hysteresis antifreeze activity; (2) low thermal hysteresis IBPs; and (3) ice-nucleating proteins (INPs). Several structurally different IBPs have evolved, even within related taxa. Proteins that produce thermal hysteresis inhibit freezing by a non-colligative mechanism, whereby they adsorb onto ice crystals or ice-nucleating surfaces and prevent further growth. This lowers the so-called hysteretic freezing point below the normal equilibrium freezing/melting point, producing a difference between the two, termed thermal hysteresis. True AFPs with high thermal hysteresis are found in freeze-avoiding animals (those that must prevent freezing, as they die if frozen) especially marine fish, insects and other terrestrial arthropods where they function to prevent freezing at temperatures below those commonly experienced by the organism. Low thermal hysteresis IBPs are found in freeze-tolerant organisms (those able to survive extracellular freezing), and function to inhibit recrystallization - a potentially damaging process whereby larger ice crystals grow at the expense of smaller ones - and in some cases, prevent lethal propagation of extracellular ice into the cytoplasm. Ice-nucleator proteins inhibit supercooling and induce freezing in the extracellular fluid at high subzero temperatures in many freeze-tolerant species, thereby allowing them to control the location and temperature of ice nucleation, and the rate of ice growth. Numerous nuances to these functions have evolved. Antifreeze glycolipids with significant thermal hysteresis activity were recently identified in insects, frogs and plants. PMID:26085662

  18. Inherited Cholesterol Disorder Significantly Boosts Heart Risks

    Science.gov (United States)

    ... leaves her cholesterol untreated, her risk of coronary heart disease death or nonfatal heart attack would be comparable to ... Recent Health News Related MedlinePlus Health Topics Cholesterol Heart Diseases--Prevention ... Us Get email updates Subscribe to RSS Follow us ...

  19. Computational model for monitoring cholesterol metabolism.

    Science.gov (United States)

    Selvakumar, R; Rashith Muhammad, M; Poornima Devi, G

    2014-12-01

    A non-deterministic finite automaton is designed to observe the cholesterol metabolism with the states of acceptance and rejection. The acceptance state of the automaton depicts the normal level of metabolism and production of good cholesterol as an end product. The rejection state of this machine shows the inhibition of enzymatic activity in cholesterol synthesis and removal of free fatty acids. The deficiency in human cholesterol metabolism pathway results in abnormal accumulation of cholesterol in plasma, arterial tissues leading to diseases such as hypercholesterolemia, atherosclerosis respectively and formation of gallstones. The designed machine can be used to monitor the cholesterol metabolism at molecular level through regulation of enzymes involved in the biosynthesis and metabolism of cholesterol for the treatment of diseases incident due to the respective metabolic disorder. In addition, an algorithm for this machine has been developed to compare the programmed string with the given string. This study demonstrates the construction of a machine that is used for the development of molecular targeted therapy for the disorders in cholesterol metabolism. PMID:26396654

  20. Cholesterol, the central lipid of mammalian cells

    NARCIS (Netherlands)

    Maxfield, F. R.; van Meer, G.

    2010-01-01

    Despite its importance for mammalian cell biology and human health, there are many basic aspects of cholesterol homeostasis that are not well understood. Even for the well-characterized delivery of cholesterol to cells via lipoproteins, a novel regulatory mechanism has been discovered recently, invo

  1. Cholesterol modulates bitter taste receptor function.

    Science.gov (United States)

    Pydi, Sai Prasad; Jafurulla, Md; Wai, Lisa; Bhullar, Rajinder P; Chelikani, Prashen; Chattopadhyay, Amitabha

    2016-09-01

    Bitter taste perception in humans is believed to act as a defense mechanism against ingestion of potential toxic substances. Bitter taste is perceived by 25 distinct bitter taste receptors (T2Rs) which belong to the family of G protein-coupled receptors (GPCRs). In the overall context of the role of membrane lipids in GPCR function, we show here that T2R4, a representative member of the bitter taste receptor family, displays cholesterol sensitivity in its signaling function. In order to gain further insight into cholesterol sensitivity of T2R4, we mutated two residues Tyr114(3.59) and Lys117(3.62) present in the cholesterol recognition amino acid consensus (CRAC) motif in T2R4 with alanines. We carried out functional characterization of the mutants by calcium mobilization, followed by cholesterol depletion and replenishment. CRAC motifs in GPCRs have previously been implicated in preferential cholesterol association. Our analysis shows that the CRAC motif represents an intrinsic feature of bitter taste receptors and is conserved in 22 out of 25 human T2Rs. We further demonstrate that Lys117, an important CRAC residue, is crucial in the reported cholesterol sensitivity of T2R4. Interestingly, cholesterol sensitivity of T2R4 was observed at quinine concentrations in the lower mM range. To the best of our knowledge, our results represent the first report addressing the molecular basis of cholesterol sensitivity in the function of taste receptors. PMID:27288892

  2. A Novel Glycolipid Biosurfactant Confers Grazing Resistance upon Pantoea ananatis BRT175 against the Social Amoeba Dictyostelium discoideum.

    Science.gov (United States)

    Smith, Derek D N; Nickzad, Arvin; Déziel, Eric; Stavrinides, John

    2016-01-01

    Pantoea is a versatile genus of bacteria with both plant- and animal-pathogenic strains, some of which have been suggested to cause human infections. There is, however, limited knowledge on the potential determinants used for host association and pathogenesis in animal systems. In this study, we used the model host Dictyostelium discoideum to show that isolates of Pantoea ananatis exhibit differential grazing susceptibility, with some being resistant to grazing by the amoebae. We carried out a high-throughput genetic screen of one grazing-resistant isolate, P. ananatis BRT175, using the D. discoideum pathosystem to identify genes responsible for the resistance phenotype. Among the 26 candidate genes involved in grazing resistance, we identified rhlA and rhlB, which we show are involved in the biosynthesis of a biosurfactant that enables swarming motility in P. ananatis BRT175. Using liquid chromatography-mass spectrometry (LC-MS), the biosurfactant was shown to be a glycolipid with monohexose-C10-C10 as the primary congener. We show that this novel glycolipid biosurfactant is cytotoxic to the amoebae and is capable of compromising cellular integrity, leading to cell lysis. The production of this biosurfactant may be important for bacterial survival in the environment and could contribute to the establishment of opportunistic infections. IMPORTANCE The genetic factors used for host interaction by the opportunistic human pathogen Pantoea ananatis are largely unknown. We identified two genes that are important for the production of a biosurfactant that confers grazing resistance against the social amoeba Dictyostelium discoideum. We show that the biosurfactant, which exhibits cytotoxicity toward the amoebae, is a glycolipid that incorporates a hexose rather than rhamnose. The production of this biosurfactant may confer a competitive advantage in the environment and could potentially contribute to the establishment of opportunistic infections. PMID:27303689

  3. Lightweight cryptography for constrained devices

    DEFF Research Database (Denmark)

    Alippi, Cesare; Bogdanov, Andrey; Regazzoni, Francesco

    2014-01-01

    Lightweight cryptography is a rapidly evolving research field that responds to the request for security in resource constrained devices. This need arises from crucial pervasive IT applications, such as those based on RFID tags where cost and energy constraints drastically limit the solution...... complexity, with the consequence that traditional cryptography solutions become too costly to be implemented. In this paper, we survey design strategies and techniques suitable for implementing security primitives in constrained devices....

  4. Prosopis farcta beans increase HDL cholesterol and decrease LDL cholesterol in ostriches (Struthio camelus).

    Science.gov (United States)

    Omidi, Arash; Ansari nik, Hossein; Ghazaghi, Mahmood

    2013-02-01

    Ten blue-neck male ostriches (Struthio camelus) were fed Prosopis farcta beans throughout a 30-day experiment. Blood samples were collected from ostriches on days 0 and 30 to measure levels of high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglyceride, total serum protein, albumin, globulin, cholesterol, calcium, inorganic phosphorus, the activity of aspartate aminotransferase, alanine aminotransferase, and γ-glutamyl transferase (γ-GT). From days 0 to 30, HDL cholesterol, total protein, and globulins levels increased significantly whereas LDL cholesterol, inorganic phosphorus, and γ-GT activity decreased significantly.

  5. Biliary cholesterol excretion: A novel mechanism that regulates dietary cholesterol absorption

    OpenAIRE

    Sehayek, Ephraim; Ono, Jennie G.; Shefer, Sarah; Nguyen, Lien B.; Wang, Nan; Batta, Ashok K.; Salen, Gerald; Smith, Jonathan D.; Tall, Alan R.; Breslow, Jan L.

    1998-01-01

    The regulation of dietary cholesterol absorption was examined in C57BL/6 and transgenic mice with liver overexpression of the scavenger receptor BI (SR-BI Tg). In C57BL/6 animals, feeding 0.02 to 1% (wt/wt) dietary cholesterol resulted in a dose-dependent decrease in the percentage of dietary cholesterol absorbed. A plot of total daily mass of dietary cholesterol absorbed versus the percentage by weight of cholesterol in the diet yielded a curve suggesting a saturable process with a Km of 0.4...

  6. The Structure of Cholesterol in Lipid Rafts

    CERN Document Server

    Toppozini, Laura; Armstrong, Clare L; Yamani, Zahra; Kucerka, Norbert; Schmid, Friederike; Rheinstaedter, Maikel C

    2014-01-01

    Rafts, or functional domains, are transient nano- or mesoscopic structures in the plasma membrane and are thought to be essential for many cellular processes such as signal transduction, adhesion, trafficking and lipid/protein sorting. Observations of these membrane heterogeneities have proven challenging, as they are thought to be both small and short-lived. With a combination of coarse-grained molecular dynamics simulations and neutron diffraction using deuterium labeled cholesterol molecules we observe raft-like structures and determine the ordering of the cholesterol molecules in binary cholesterol-containing lipid membranes. From coarse-grained computer simulations, heterogenous membranes structures were observed and characterized as small, ordered domains. Neutron diffraction was used to study the lateral structure of the cholesterol molecules. We find pairs of strongly bound cholesterol molecules in the liquid-disordered phase, in accordance with the umbrella model. Bragg peaks corresponding to orderin...

  7. Trapping crystal nucleation of cholesterol monohydrate

    DEFF Research Database (Denmark)

    Solomonov, I.; Weygand, M.J.; Kjær, K.;

    2005-01-01

    Crystalline nucleation of cholesterol at the air-water interface has been studied via grazing incidence x-ray diffraction using synchrotron radiation. The various stages of cholesterol molecular assembly from monolayer to three bilayers incorporating interleaving hydrogen-bonded water layers...... in a monoclinic cholesterol . H2O phase, has been monitored and their structures characterized to near atomic resolution. Crystallographic evidence is presented that this multilayer phase is similar to that of a reported metastable cholesterol phase of undetermined structure obtained from bile before...... transformation to the triclinic phase of cholesterol . H2O, the thermodynamically stable macroscopic form. According to grazing incidence x-ray diffraction measurements and crystallographic data, a transformation from the monoclinic film structure to a multilayer of the stable monohydrate phase involves...

  8. Analysis of NMR spectra of sugar chains of glycolipids by 1D homonuclear Hartmann-Hahn and NOE experiments

    International Nuclear Information System (INIS)

    The authors applied 1D homonuclear Hartmann-Hahn (1D-HOHAHA) and difference NOE experiments to determine the chemical structure of Forssman's antigen, a glycolipid purified from sheep red blood cells. The subspectra corresponding to the individual sugar components were extracted from overlapping proton resonances by selective excitation of the anomeric proton resonances, so that unambiguous assignments of the sugar proton resonances were accomplished. Then, difference NOE experiments were performed to determine the linkage of the sugar units. The present procedure was found to be useful for the structure determination of glycoconjugates and also reduces the amount of samples and machine time. 8 refs.; 3 figs

  9. Strong IgG antibody responses to Borrelia burgdorferi glycolipids in patients with Lyme arthritis, a late manifestation of the infection.

    Science.gov (United States)

    Jones, Kathryn L; Seward, Robert J; Ben-Menachem, Gil; Glickstein, Lisa J; Costello, Catherine E; Steere, Allen C

    2009-07-01

    In this study, the membrane lipids of B. burgdorferi were separated into 16 fractions; the components in each fraction were identified, and the immunogenicity of each fraction was determined by ELISA using sera from Lyme disease patients. Only the 2 glycolipids, acylated cholesteryl galactoside (ACG, BbGL-I) and monogalactosyl diacylglycerol (MgalD, BbGL-II), were immunogenic. Early in the infection, 24 of 84 patients (29%) who were convalescent from erythema migrans and 19 of the 35 patients (54%) with neuroborreliosis had weak IgG responses to purified MgalD, and a smaller percentage of patients had early responses to synthetic ACG. However, almost all of 75 patients with Lyme arthritis, a late disease manifestation, had strong IgG reactivity with both glycolipids. Thus, almost all patients with Lyme arthritis have strong IgG antibody responses to B. burgdorferi glycolipid antigens.

  10. Major Risk Factors for Heart Disease: High Blood Cholesterol

    Science.gov (United States)

    ... Major Risk Factors for Heart Disease High Blood Cholesterol High blood cholesterol is another major risk factor for heart disease ... can do something about. The higher your blood cholesterol level, the greater your risk for developing heart ...

  11. High Blood Cholesterol: What You Need to Know

    Science.gov (United States)

    ... Audiences Contact The Health Information Center High Blood Cholesterol: What You Need To Know Table of Contents ... Lifestyle Changes (TLC) Drug Treatment Resources Why Is Cholesterol Important? Your blood cholesterol level has a lot ...

  12. Endogenous cholesterol synthesis, fecal steroid excretion and serum lanosterol in subjects with high or low response of serum cholesterol to dietary cholesterol

    NARCIS (Netherlands)

    Beynen, A.C.; Katan, M.B.; Gent, van C.M.

    1986-01-01

    In this study we addressed the question whether hypo- and hyper-responders to dietary cholesterol differ with regard to the flexibility of endogenous cholesterol synthesis after changes in cholesterol intake. Whole-body cholesterol synthesis was measured as faecal excretion of neutral steroids and b

  13. Absence of lactobacilli containing glycolipids with the α-galactose epitope and the enhanced fucosylation of a receptor glycolipid GA1 in the digestive tracts of immune-deficient scid mice.

    Science.gov (United States)

    Iwamori, Masao; Tanaka, Kyoko; Adachi, Shigeki; Aoki, Daisuke; Nomura, Taisei

    2015-07-01

    The Lactobacillus species in the digestive tracts of immune-deficient scid mice was distinct from that in control mice, i.e. Lactobacillus murinus in scid and L. johnsonii in control mice, according to their 16S-rRNA, indicating that a symbiotic relationship between lactobacilli and a host is established under pressure from the immune system. The caecal and colonal contents rich in L. murinus of scid mice were loose with a strong sour smell, resulting in diarrhoea, and those with L. johnsonii in control mice included abundant solid materials. Lactobacillus glycolipids were revealed to be recognized by the immune system, and by TLC-immunostaining, LacTetH-DG (Galα1-6Galα1-6Galα1-2Glcα1-3'DG) of L. johnsonii was detected in the stomach, caecum and colon of control mice, but not in those of scid ones, in which fucosylation of a receptor GA1 for L. johnsonii was enhanced more than 4-fold compared with in the control mice. Thus, structural modification of receptor glycolipids was revealed to occur in the process of establishment of a symbiotic relationship between lactobacilli and a host. LacTetH-DG was also immunogenic to human, because of the presence of natural antibodies against it, and the antibody binding to it was comparable to that of blood group- and species-related glycosphingolipids.

  14. The Structural Basis of Cholesterol Accessibility in Membranes

    OpenAIRE

    Olsen, Brett N.; Bielska, Agata A.; Lee, Tiffany; Daily, Michael D.; Covey, Douglas F.; Schlesinger, Paul H.; Baker, Nathan A.; Ory, Daniel S.

    2013-01-01

    Although the majority of free cellular cholesterol is present in the plasma membrane, cholesterol homeostasis is principally regulated through sterol-sensing proteins that reside in the cholesterol-poor endoplasmic reticulum (ER). In response to acute cholesterol loading or depletion, there is rapid equilibration between the ER and plasma membrane cholesterol pools, suggesting a biophysical model in which the availability of plasma membrane cholesterol for trafficking to internal membranes mo...

  15. Perturbed cholesterol homeostasis in aging spinal cord.

    Science.gov (United States)

    Parkinson, Gemma M; Dayas, Christopher V; Smith, Doug W

    2016-09-01

    The spinal cord is vital for the processing of sensorimotor information and for its propagation to and from both the brain and the periphery. Spinal cord function is affected by aging, however, the mechanisms involved are not well-understood. To characterize molecular mechanisms of spinal cord aging, microarray analyses of gene expression were performed on cervical spinal cords of aging rats. Of the metabolic and signaling pathways affected, cholesterol-associated pathways were the most comprehensively altered, including significant downregulation of cholesterol synthesis-related genes and upregulation of cholesterol transport and metabolism genes. Paradoxically, a significant increase in total cholesterol content was observed-likely associated with cholesterol ester accumulation. To investigate potential mechanisms for the perturbed cholesterol homeostasis, we quantified the expression of myelin and neuroinflammation-associated genes and proteins. Although there was minimal change in myelin-related expression, there was an increase in phagocytic microglial and astrogliosis markers, particularly in the white matter. Together, these results suggest that perturbed cholesterol homeostasis, possibly as a result of increased inflammatory activation in spinal cord white matter, may contribute to impaired spinal cord function with aging. PMID:27459933

  16. Physiological and pathological implications of cholesterol.

    Science.gov (United States)

    Cortes, Victor A; Busso, Dolores; Maiz, Alberto; Arteaga, Antonio; Nervi, Flavio; Rigotti, Attilio

    2014-01-01

    Cholesterol has evolved to fulfill sophisticated biophysical, cell signaling and endocrine requirements of animal systems. At a cellular level, cholesterol is found in membranes, where it increases both bilayer stiffness and impermeability to water and ions. Furthermore, cholesterol is integrated into specialized lipid-protein membrane microdomains with critical topographical and signaling functions. At an organismal level, cholesterol is the precursor for all steroid hormones, including gluco- and mineralo-corticoids, sex hormones and vitamin D, all of which regulate carbohydrate, sodium, reproductive and bone homeostasis, respectively. This sterol is also the precursor for bile acids, which are important for intestinal absorption of dietary lipids as well as energy and glucose metabolic regulation. Importantly, complex mechanisms maintain cholesterol within physiological ranges and the disregulation of these mechanisms results in embryonic or adult diseases, caused by either excessive or reduced tissue cholesterol levels. The causative role of cholesterol in these diseases has been demonstrated by diverse genetic and pharmacologic animal models that are commented in this review. PMID:24389193

  17. Seasonal lake surface water temperature trends reflected by heterocyst glycolipid-based molecular thermometers

    Science.gov (United States)

    Bauersachs, T.; Rochelmeier, J.; Schwark, L.

    2015-06-01

    It has been demonstrated that the relative distribution of heterocyst glycolipids (HGs) in cultures of N2-fixing heterocystous cyanobacteria is largely controlled by growth temperature, suggesting a potential use of these components in paleoenvironmental studies. Here, we investigated the effect of environmental parameters (e.g., surface water temperatures, oxygen concentrations and pH) on the distribution of HGs in a natural system using water column filtrates collected from Lake Schreventeich (Kiel, Germany) from late July to the end of October 2013. HPLC-ESI/MS (high-performance liquid chromatography coupled to electrospray ionization-mass spectrometry) analysis revealed a dominance of 1-(O-hexose)-3,25-hexacosanediols (HG26 diols) and 1-(O-hexose)-3-keto-25-hexacosanol (HG26 keto-ol) in the solvent-extracted water column filtrates, which were accompanied by minor abundances of 1-(O-hexose)-3,27-octacosanediol (HG28 diol) and 1-(O-hexose)-3-keto-27-octacosanol (HG28 keto-ol) as well as 1-(O-hexose)-3,25,27-octacosanetriol (HG28 triol) and 1-(O-hexose)-3-keto-25,27-octacosanediol (HG28 keto-diol). Fractional abundances of alcoholic and ketonic HGs generally showed strong linear correlations with surface water temperatures and no or only weak linear correlations with both oxygen concentrations and pH. Changes in the distribution of the most abundant diol and keto-ol (e.g., HG26 diol and HG26 keto-ol) were quantitatively expressed as the HDI26 (heterocyst diol index of 26 carbon atoms) with values of this index ranging from 0.89 in mid-August to 0.66 in mid-October. An average HDI26 value of 0.79, which translates into a calculated surface water temperature of 15.8 ± 0.3 °C, was obtained from surface sediments collected from Lake Schreventeich. This temperature - and temperatures obtained from other HG indices (e.g., HDI28 and HTI28) - is similar to the one measured during maximum cyanobacterial productivity in early to mid-September and suggests that HGs

  18. Seasonal lake surface water temperature trends reflected by heterocyst glycolipid based molecular thermometers

    Science.gov (United States)

    Bauersachs, T.; Rochelmeier, J.; Schwark, L.

    2015-01-01

    It has been demonstrated that the relative distribution of heterocyst glycolipids (HGs) in cultures of N2-fixing heterocystous cyanobacteria is largely controlled by growth temperature, suggesting a potential use of these components in paleoenvironmental studies. Here, we investigated the effect of environmental parameters (e.g. surface water temperatures, oxygen concentrations and pH) on the distribution of HGs in a natural system using water column filtrates collected from Lake Schreventeich (Kiel, Germany) from late July to the end of October 2013. HPLC-ESI/MS analysis revealed a dominance of 1-(O-hexose)-3,25-hexacosanediols (HG26 diols) and 1-(O-hexose)-3-keto-25-hexacosanol (HG26 keto-ol) in the solvent extracted water column filtrates, which were accompanied by minor abundances of 1-(O-hexose)-3,27-octacosanediol (HG28 diol) and 1-(O-hexose)-3-keto-27-octacosanol (HG28 keto-ol) as well as 1-(O-hexose)-3,25,27-octacosanetriol (HG28 triol) and 1-(O-hexose)-3-keto-25,27-octacosanediol (HG28 keto-diol). Fractional abundances of alcoholic and ketonic HGs generally showed strong linear correlations with surface water temperatures and no or only weak linear correlations with both oxygen concentrations and pH. Changes in the distribution of the most abundant diol and keto-ol (e.g., HG26 diol and HG26 keto-ol) were quantitatively expressed as the HDI26 (heterocyst diol index of 26carbon atoms) with values of this index ranging from 0.89 in mid-August to 0.66 in mid-October. An average HDI26 value of 0.79, which translates into a calculated surface water temperature of 15.8 ± 0.3 °C, was obtained from surface sediments collected from Lake Schreventeich. This temperature - and temperatures obtained from other HG indices (e.g., HDI28 and HTI28) - is similar to the one measured during maximum cyanobacterial productivity in early to mid-September and suggests that HGs preserved in Lake Schreventeich sediments record summer surface water temperatures. As N2-fixing

  19. Detecting Protein-Glycolipid Interactions Using Glycomicelles and CaR-ESI-MS

    Science.gov (United States)

    Han, Ling; Kitova, Elena N.; Klassen, John S.

    2016-08-01

    This study reports on the use of the catch-and-release electrospray ionization mass spectrometry (CaR-ESI-MS) assay, combined with glycomicelles, as a method for detecting specific interactions between water-soluble proteins and glycolipids (GLs) in aqueous solution. The B subunit homopentamers of cholera toxin (CTB5) and Shiga toxin type 1 B (Stx1B5) and the gangliosides GM1, GM2, GM3, GD1a, GD1b, GT1b, and GD2 served as model systems for this study. The CTB5 exhibits broad specificity for gangliosides and binds to GM1, GM2, GM3, GD1a, GD1b, and GT1b; Stx1B5 does not recognize gangliosides. The CaR-ESI-MS assay was used to analyze solutions of CTB5 or Stx1B5 and individual gangliosides (GM1, GM2, GM3, GD1a, GD1b, GT1b, and GD2) or mixtures thereof. The high affinity interaction of CTB5 with GM1 was successfully detected. However, the apparent affinity, as determined from the mass spectra, is significantly lower than that of the corresponding pentasaccharide or when GM1 is presented in model membranes such as nanodiscs. Interactions between CTB5 and the low affinity gangliosides GD1a, GD1b, and GT1b, as well as GD2, which served as a negative control, were detected; no binding of CTB5 to GM2 or GM3 was observed. The CaR-ESI-MS results obtained for Stx1B5 reveal that nonspecific protein-ganglioside binding can occur during the ESI process, although the extent of binding varies between gangliosides. Consequently, interactions detected for CTB5 with GD1a, GD1b, and GT1b are likely nonspecific in origin. Taken together, these results reveal that the CaR-ESI-MS/glycomicelle approach for detecting protein-GL interactions is prone to false positives and false negatives and must be used with caution.

  20. HDL: More Than Just Cholesterol

    Directory of Open Access Journals (Sweden)

    Anna Meilina

    2010-12-01

    Full Text Available BACKGROUND: Plasma concentration of high density lipoprotein cholesterol (HDL-C are strongly, consistenly, and independently inversely associated with risk of atheroschlerotic cardiovascular disease (CVD. However, the last decade has seen several observations that do not follow this simple script. CONTENT: A proteomic analysis of HDL has given us an intriguing glimpse into novel components of HDL. HDL isolated from normal humans contains several classes of proteins, including not only apolipoproteins, but also complement regulatory proteins, endopeptidase inhibitors, hemopexin, and acute phase response proteins. These observations raise the possibility of unsuspected roles for HDL. HDL delivery of complement proteins would implicate HDL in innate immunity. Serine proteinase inhibitors would enable HDL to modulate proteolysis of the vessel wall. HDL from patients with coronary artery disease was enriched in apoE, apoC-IV, apoA-IV, Paraoxonase (PON, and complement factor C3. Highlighted additional mechanisms through which HDL protects the vessel wall are: HDL improves vascular function, decreases vascular inflammation, detoxifies radicals, and limits thrombosis. SUMMARY: Both inter- and intra-organ desynchrony may be involved in the pathogenesis of cardiometabolic disease attributable to effects in brain and multiple metabolic tissues including heart, liver, fat, muscle, pancreas, and gut. Efforts to dissect the molecular mediators that coordinate circadian, metabolic, and cardiovascular systems may ultimately lead to both improved therapeutics and preventive interventions. KEYWORDS: HDL, Apo–A1, RCT, inflammation, HDL dysfunction, HDL proteome, HDL & Apo-A1 mimetics.

  1. Antibody to endotoxin core glycolipid reverses reticuloendothelial system depression in an animal model of severe sepsis and surgical injury

    International Nuclear Information System (INIS)

    To study the effect of severe sepsis on the function of the reticuloendothelial system (RES) we have measured the clearance kinetics and organ distribution of both low-dose technetium tin colloid (TTC) and 75selenomethionine-labelled E. coli in rabbits 24 hours after either sham laparotomy or appendix devascularization. Sepsis resulted in similar delayed blood clearance and reduced liver (Kupffer cell) uptake of both TTC and E. coli. To investigate the ability of polyclonal antibody to E. coli-J-5 (core glycolipid) to improve RES function in the same model of sepsis, further animals were pretreated with either core glycolipid antibody or control serum (10 ml IV) 2 hours before induction of sepsis. TTC clearance kinetics were determined 24 hours later. Antibody pretreated animals showed: a reduced incidence of bacteremia; normalization of the rate of blood clearance and liver uptake of TTC; and a 'rebound' increase in splenic uptake of TTC. We conclude that antibody to E. coli-J-5 enhances bacterial clearance by the RES

  2. Isolation of Pseudozyma churashimaensis sp. nov., a novel ustilaginomycetous yeast species as a producer of glycolipid biosurfactants, mannosylerythritol lipids.

    Science.gov (United States)

    Morita, Tomotake; Ogura, Yuki; Takashima, Masako; Hirose, Naoto; Fukuoka, Tokuma; Imura, Tomohiro; Kondo, Yukishige; Kitamoto, Dai

    2011-08-01

    An ustilaginomycetous anamorphic yeast species isolated from the leaves of Saccharum officinarum (sugarcane) in Okinawa, Japan, was identified as a novel Pseudozyma species based on morphological and physiological aspects and molecular taxonomic analysis using the D1/D2 domains of the large subunit (26S) rRNA gene and the internal transcribed spacer 1 (ITS1)-5.8S-ITS2 regions. The name Pseudozyma churashimaensis sp. nov. was proposed for the novel species, with JCM 16988(T) as the type strain. Interestingly, P. churashimaensis was found to produce glycolipid biosurfactants, a mixture of mannosylerythritol lipids (MELs), including a novel tri-acetylated derivative (MEL-A2), from glucose. The observed critical micelle concentration (CMC) and the surface tension at CMC of MEL-A2 were 1.7 × 10⁻⁶ M and 29.2 mN/m, respectively. Moreover, on a water-penetration scan, MEL-A2 efficiently formed different lyotropic liquid crystalline phases, including the lamella phase at a wide range of concentrations, indicating its excellent surface-active and self-assembling properties. The novel strain of the genus Pseudozyma should thus facilitate the application of glycolipid biosurfactants in combination with other MEL producers. PMID:21606002

  3. Antibody to endotoxin core glycolipid reverses reticuloendothelial system depression in an animal model of severe sepsis and surgical injury

    Energy Technology Data Exchange (ETDEWEB)

    Aldridge, M.C.; Chadwick, S.J.; Cheslyn-Curtis, S.; Rapson, N.; Dudley, H.A.

    1987-10-01

    To study the effect of severe sepsis on the function of the reticuloendothelial system (RES) we have measured the clearance kinetics and organ distribution of both low-dose technetium tin colloid (TTC) and /sup 75/selenomethionine-labelled E. coli in rabbits 24 hours after either sham laparotomy or appendix devascularization. Sepsis resulted in similar delayed blood clearance and reduced liver (Kupffer cell) uptake of both TTC and E. coli. To investigate the ability of polyclonal antibody to E. coli-J-5 (core glycolipid) to improve RES function in the same model of sepsis, further animals were pretreated with either core glycolipid antibody or control serum (10 ml IV) 2 hours before induction of sepsis. TTC clearance kinetics were determined 24 hours later. Antibody pretreated animals showed: a reduced incidence of bacteremia; normalization of the rate of blood clearance and liver uptake of TTC; and a 'rebound' increase in splenic uptake of TTC. We conclude that antibody to E. coli-J-5 enhances bacterial clearance by the RES.

  4. Diet serum cholesterol and coronary diseases

    Directory of Open Access Journals (Sweden)

    Narindar Nath

    1961-07-01

    Full Text Available The probable sequence of events leading to atherosclerotic disease of the coronary artery and heart attack are briefly described. Blood cholesterol as a casual agent in atherosclerosis and how blood cholesterol can be modified are discussed. The effects of various dietary components particularly quality and quantity of fat and protein on the blood cholesterol concentration are discussed and it is emphasized that more work needs to be done to ascertain the role of individual components of the diet and their relative importance in atherogenesis.

  5. The role of cholesterol in membrane fusion.

    Science.gov (United States)

    Yang, Sung-Tae; Kreutzberger, Alex J B; Lee, Jinwoo; Kiessling, Volker; Tamm, Lukas K

    2016-09-01

    Cholesterol modulates the bilayer structure of biological membranes in multiple ways. It changes the fluidity, thickness, compressibility, water penetration and intrinsic curvature of lipid bilayers. In multi-component lipid mixtures, cholesterol induces phase separations, partitions selectively between different coexisting lipid phases, and causes integral membrane proteins to respond by changing conformation or redistribution in the membrane. But, which of these often overlapping properties are important for membrane fusion?-Here we review a range of recent experiments that elucidate the multiple roles that cholesterol plays in SNARE-mediated and viral envelope glycoprotein-mediated membrane fusion. PMID:27179407

  6. Turbulence as a constrained system

    CERN Document Server

    Mendes, A C R; Takakura, F I

    2000-01-01

    Hydrodynamic turbulence is studied as a constrained system from the point of view of metafluid dynamics. We present a Lagrangian description for this new theory of turbulence inspired from the analogy with electromagnetism. Consequently it is a gauge theory. This new approach to the study of turbulence tends to renew the optimism to solve the difficult problem of turbulence. As a constrained system, turbulence is studied in the Dirac and Faddeev-Jackiw formalisms giving the Dirac brackets. An important result is that we show these brackets are the same in and out of the inertial range, giving the way to quantize turbulence.

  7. What Do My Cholesterol Levels Mean?

    Science.gov (United States)

    ... goes beyond cholesterol levels alone and considers overall risk assessment and reduction. It's still important to know your numbers, but work with your healthcare provider to treat your risk. What numbers do ...

  8. How to Get Your Cholesterol Tested

    Science.gov (United States)

    ... six years as part of a cardiovascular risk assessment. You may need to have your cholesterol and other risk factors assessed more often if your risk is elevated. Your healthcare provider will talk with you about what your ...

  9. Cholesterol oxidation products and their biological importance.

    Science.gov (United States)

    Kulig, Waldemar; Cwiklik, Lukasz; Jurkiewicz, Piotr; Rog, Tomasz; Vattulainen, Ilpo

    2016-09-01

    The main biological cause of oxysterols is the oxidation of cholesterol. They differ from cholesterol by the presence of additional polar groups that are typically hydroxyl, keto, hydroperoxy, epoxy, or carboxyl moieties. Under typical conditions, oxysterol concentration is maintained at a very low and precisely regulated level, with an excess of cholesterol. Like cholesterol, many oxysterols are hydrophobic and hence confined to cell membranes. However, small chemical differences between the sterols can significantly affect how they interact with other membrane components, and this in turn can have a substantial effect on membrane properties. In this spirit, this review describes the biological importance and the roles of oxysterols in the human body. We focus primarily on the effect of oxysterols on lipid membranes, but we also consider other issues such as enzymatic and nonenzymatic synthesis processes of oxysterols as well as pathological conditions induced by oxysterols. PMID:26956952

  10. A new framework for reverse cholesterol transport: Non-biliary contributions to reverse cholesterol transport

    Institute of Scientific and Technical Information of China (English)

    Ryan; E; Temel; J; Mark; Brown

    2010-01-01

    Reduction of low-density lipoprotein-cholesterol through statin therapy has only modestly decreased coronary heart disease (CHD)-associated mortality in developed countries, which has prompted the search for alternative therapeutic strategies for CHD. Major efforts are now focused on therapies that augment high-density lipoprotein (HDL)-mediated reverse cholesterol transport (RCT), and ultimately increase the fecal disposal of cholesterol. The process of RCT has long been thought to simply involve HDL-media...

  11. From blood to gut: Direct secretion of cholesterol via transintestinal cholesterol efflux

    Institute of Scientific and Technical Information of China (English)

    Carlos; LJ; Vrins

    2010-01-01

    The reverse cholesterol transport pathway (RCT) is the focus of many cholesterol-lowering therapies. By way of this pathway, excess cholesterol is collected from peripheral tissues and delivered back to the liver and gastrointestinal tract for excretion from the body. For a long time this removal via the hepatobiliary secretion was considered to be the sole route involved in the RCT. However, observations from early studies in animals and humans already pointed towards the possibility of another route. In t...

  12. Assessing possible hazards of reducing serum cholesterol.

    OpenAIRE

    Law, M. R.; Thompson, S. G.; Wald, N J

    1994-01-01

    OBJECTIVE--To assess whether low serum cholesterol concentration increases mortality from any cause. DESIGN--Systematic review of published data on mortality from causes other than ischaemic heart disease derived from the 10 largest cohort studies, two international studies, and 28 randomised trials, supplemented by unpublished data on causes of death obtained when necessary. MAIN OUTCOME MEASURES--Excess cause specific mortality associated with low or lowered serum cholesterol concentration....

  13. Dietary Phospholipids and Intestinal Cholesterol Absorption

    OpenAIRE

    Sally Tandy; Chung, Rosanna W. S.; Elaine Wat; Alvin Kamili; Cohn, Jeffrey S.

    2010-01-01

    Experiments carried out with cultured cells and in experimental animals have consistently shown that phospholipids (PLs) can inhibit intestinal cholesterol absorption. Limited evidence from clinical studies suggests that dietary PL supplementation has a similar effect in man. A number of biological mechanisms have been proposed in order to explain how PL in the gut lumen is able to affect cholesterol uptake by the gut mucosa. Further research is however required to establish whether the abili...

  14. Cholesterol suppresses antimicrobial effect of statins

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Haeri

    2015-12-01

    Full Text Available Objective(s:Isoprenoid biosynthesis is a key metabolic pathway to produce a wide variety of biomolecules such as cholesterol and carotenoids, which target cell membranes. On the other hand, it has been reported that statins known as inhibitors of isoprenoid biosynthesis and cholesterol lowering agents, may have a direct antimicrobial effect on the some bacteria. The exact action of statins in microbial metabolism is not clearly understood. It is possible that statins inhibit synthesis or utilization of some sterol precursor necessary for bacterial membrane integrity. Accordingly, this study was designed in order to examine if statins inhibit the production of a compound, which can be used in the membrane, and whether cholesterol would replace it and rescue bacteria from toxic effects of statins. Materials and Methods: To examine the possibility we assessed antibacterial effect of statins with different classes; lovastatin, simvastatin, and atorvastatin, alone and in combination with cholesterol on two Gram-positive (Staphylococcus aureus and Enterococcus faecalis and two Gram-negative (Pseudomonas aeruginosa and Escherichia coli bacteria using gel diffusion assay. Results: Our results showed that all of the statins except for lovastatin had significant antibacterial property in S. aureus, E. coli, and Enter. faecalis. Surprisingly, cholesterol nullified the antimicrobial action of effective statins in statin-sensitive bacteria. Conclusion: It is concluded that statins may deprive bacteria from a metabolite responsible for membrane stability, which is effectively substituted by cholesterol.

  15. Dietary cholesterol modulates pathogen blocking by Wolbachia.

    Directory of Open Access Journals (Sweden)

    Eric P Caragata

    Full Text Available The bacterial endosymbiont Wolbachia pipientis protects its hosts from a range of pathogens by limiting their ability to form infections inside the insect. This "pathogen blocking" could be explained by innate immune priming by the symbiont, competition for host-derived resources between pathogens and Wolbachia, or the direct modification of the cell or cellular environment by Wolbachia. Recent comparative work in Drosophila and the mosquito Aedes aegypti has shown that an immune response is not required for pathogen blocking, implying that there must be an additional component to the mechanism. Here we have examined the involvement of cholesterol in pathogen blocking using a system of dietary manipulation in Drosophila melanogaster in combination with challenge by Drosophila C virus (DCV, a common fly pathogen. We observed that flies reared on cholesterol-enriched diets infected with the Wolbachia strains wMelPop and wMelCS exhibited reduced pathogen blocking, with viral-induced mortality occurring 2-5 days earlier than flies reared on Standard diet. This shift toward greater virulence in the presence of cholesterol also corresponded to higher viral copy numbers in the host. Interestingly, an increase in dietary cholesterol did not have an effect on Wolbachia density except in one case, but this did not directly affect the strength of pathogen blocking. Our results indicate that host cholesterol levels are involved with the ability of Wolbachia-infected flies to resist DCV infections, suggesting that cholesterol contributes to the underlying mechanism of pathogen blocking.

  16. CHOLESTEROL ASSIMILATION BY COMMERCIAL YOGHURT STARTER CULTURES

    Directory of Open Access Journals (Sweden)

    Małgorzata Ziarno

    2007-03-01

    Full Text Available The ability to in vitro cholesterol level reduction in laboratory media has been shown for numerous strains of lactic acid bacteria, but not for all strains of lactic bacteria used in the dairy industry. The aim of this work was the determination of the ability of selected thermophilic lactic acid bacteria to cholesterol assimilation during 24 h culture in MRS broth. Commercial starter cultures showed various ability to cholesterol assimilation from laboratory medium. In case of starter cultures used for production of traditional yoghurt, consisting of Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, the quantity of assimilated cholesterol did not exceed 27% of its initial contents (0.7 g in 1 dm3. Starter cultures used for bioyoghurt production, containing also probiotic strains (came from Lactobacillus acidophilus species or Bifidobacterium genus assimilated from almost 18% to over 38% of cholesterol. For one monoculture of Lb. acidophilus, cholesterol assimilation ability of 49-55% was observed, despite that the number of bacterial cells in this culture was not different from number of bacteria in other cultures.

  17. Statin-induced chronic cholesterol depletion inhibits Leishmania donovani infection: Relevance of optimum host membrane cholesterol.

    Science.gov (United States)

    Kumar, G Aditya; Roy, Saptarshi; Jafurulla, Md; Mandal, Chitra; Chattopadhyay, Amitabha

    2016-09-01

    Leishmania are obligate intracellular protozoan parasites that invade and survive within host macrophages leading to leishmaniasis, a major cause of mortality and morbidity worldwide, particularly among economically weaker sections in tropical and subtropical regions. Visceral leishmaniasis is a potent disease caused by Leishmania donovani. The detailed mechanism of internalization of Leishmania is poorly understood. A basic step in the entry of Leishmania involves interaction of the parasite with the host plasma membrane. In this work, we have explored the effect of chronic metabolic cholesterol depletion using lovastatin on the entry and survival of Leishmania donovani in host macrophages. We show here that chronic cholesterol depletion of host macrophages results in reduction in the attachment of Leishmania promastigotes, along with a concomitant reduction in the intracellular amastigote load. These results assume further relevance since chronic cholesterol depletion is believed to mimic physiological cholesterol modulation. Interestingly, the reduction in the ability of Leishmania to enter host macrophages could be reversed upon metabolic replenishment of cholesterol. Importantly, enrichment of host membrane cholesterol resulted in reduction in the entry and survival of Leishmania in host macrophages. As a control, the binding of Escherichia coli to host macrophages remained invariant under these conditions, thereby implying specificity of cholesterol requirement for effective leishmanial infection. To the best of our knowledge, these results constitute the first comprehensive demonstration that an optimum content of host membrane cholesterol is necessary for leishmanial infection. Our results assume relevance in the context of developing novel therapeutic strategies targeting cholesterol-mediated leishmanial infection. PMID:27319380

  18. Binding of fluorescently labeled cholera toxin subunit B to glycolipids in the human submandibular gland and inhibition of binding by periodate oxidation and by galactose

    DEFF Research Database (Denmark)

    Kirkeby, S

    2016-01-01

    to the internal galactose residue linked to GalNAc, as in the GM1 glycolipid. Inhibition of the GM1 receptor binding to cholera toxin has potential for protection of humans against cholera. Galactose and agents that modify sialic acid inhibit the accessibility of the toxin to the GM1 carbohydrate receptor. Human...

  19. Toxin a from Clostridium difficile binds to rabbit erythrocyte glycolipids with therminal Gal. cap alpha. 1-3Gal. beta. 1-4GlcNaC sequences

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.F.; Krivan, H.; Wilkins, T.; Smith, D.F.

    1987-05-01

    Toxin A is one of two clostridial toxins implicated as the causative agent of pseudomembranous colitis in patients undergoing postoperative antibiotic therapy. Evidence that the carbohydrate binding determinant for this toxin is a glycoconjugate(s) with non-reducing Gal..cap alpha..1-3Gal..beta..1-4GlcNAc has recently been reported. Specific agglutination of rabbit erythrocytes by Toxin A is inhibited by bovine thyroglobulin and prevented by pretreatment of cells with ..cap alpha..-galactosidase. Total lipid extracts from rabbit erythrocytes were subjected to thin layer chromatography and the chromatogram overlaid with purified /sup 125/I-labeled Toxin A. Two major and several minor toxin-binding glycolipids were detected following autoradiography. The major toxin-binding glycolipids were identified as pentasaccharide- and decasaccharide-ceramides expressing terminal Gal..cap alpha..1-3Gal..beta..1-4GlcNAc sequences. Treatment of the toxin-binding glycolipids with ..cap alpha..-galactosidase abolished binding. Forsmann glycolipid, globoside, Gal..cap alpha..1-4 Gal..beta..1-4Glc-cer, and Gal..cap alpha..1-3Gal..beta..1-4Glc-cer did not bind the toxin. These observations are consistent with the proposed carbohydrate specificity of the toxin for the non-reducing terminal sequence, Gal..cap alpha..1-3Gal..beta..1-4GlcNAc.

  20. Lipoarabinomannan, and its related glycolipids, induce divergent and opposing immune responses to Mycobacterium tuberculosis depending on structural diversity and experimental variations.

    Science.gov (United States)

    Källenius, Gunilla; Correia-Neves, Margarida; Buteme, Helen; Hamasur, Beston; Svenson, Stefan B

    2016-01-01

    Exposure to Mycobacterium tuberculosis (Mtb) may lead to active or latent tuberculosis, or clearance of Mtb, depending essentially on the quality of the host's immune response. This response is initiated through the interaction of Mtb cell wall surface components, mostly glycolipids, with cells of the innate immune system, particularly macrophages (Mφs) and dendritic cells (DCs). The way Mφs and DC alter their cytokine secretome, activate or inhibit different microbicidal mechanisms and present antigens and consequently trigger the T cell-mediated immune response impacts the host immune response against Mtb. Lipoarabinomannan (LAM) is one of the major cell wall components of Mtb. Mannosyl-capped LAM (ManLAM), and its related cell wall-associated types of glycolipids/lipoglycans, namely phosphatidylinositol mannosides (PIMs) and lipomannan (LM), exhibit important and distinct immunomodulatory properties. The structure, internal heterogeneity and abundance of these molecules vary between Mtb strains exhibiting distinct degrees of virulence. Thus ManLAM, LM and PIMs may be considered crucial Mtb-associated virulence factors in the pathogenesis of tuberculosis. Of particular relevance for this review, there is controversy about the specific immunomodulatory properties of these distinct glycolipids, particularly when tested as purified molecules in vitro. In addition to the variability in the glycolipid composition conflicting reports may also result from differences in the protocols used for glycolipid isolation and for in vitro experiments including immune cell types and procedures to generate them. Understanding the immunomodulatory properties of these cell wall glycolipids, how they differ between distinct Mtb strains, and how they influence the degree of Mtb virulence, is of utmost relevance to understand how the host mounts a protective or otherwise pathologic immune response. This is essential for the design of preventive strategies against tuberculosis. Thus

  1. The Structural Basis of Cholesterol Activity in Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Brett N.; Bielska, Agata; Lee, Tiffany; Daily, Michael D.; Covey, Douglas F.; Schlesinger, Paul H.; Baker, Nathan A.; Ory, Daniel S.

    2013-10-15

    Although the majority of free cellular cholesterol is present in the plasma membrane, cholesterol homeostasis is principally regulated through sterol-sensing proteins that reside in the cholesterol-poor endoplasmic reticulum (ER). In response to acute cholesterol loading or depletion, there is rapid equilibration between the ER and plasma membrane cholesterol pools, suggesting a biophysical model in which the availability of plasma membrane cholesterol for trafficking to internal membranes modulates ER membrane behavior. Previous studies have predominantly examined cholesterol availability in terms of binding to extramembrane acceptors, but have provided limited insight into the structural changes underlying cholesterol activation. In this study, we use both molecular dynamics simulations and experimental membrane systems to examine the behavior of cholesterol in membrane bilayers. We find that cholesterol depth within the bilayer provides a reasonable structural metric for cholesterol availability and that this is correlated with cholesterol-acceptor binding. Further, the distribution of cholesterol availability in our simulations is continuous rather than divided into distinct available and unavailable pools. This data provide support for a revised cholesterol activation model in which activation is driven not by saturation of membrane-cholesterol interactions but rather by bulk membrane remodeling that reduces membrane-cholesterol affinity.

  2. The glycoinositol phospholipids of Leishmania mexicana promastigotes. Evidence for the presence of three distinct pathways of glycolipid biosynthesis.

    Science.gov (United States)

    McConville, M J; Collidge, T A; Ferguson, M A; Schneider, P

    1993-07-25

    Most macromolecules at the cell surface of parasitic protozoa of the genus Leishmania, including the major surface glycoproteins and a complex lipophosphoglycan (LPG), are attached to the plasma membrane via glycosyl-phosphatidylinositol (GPI) anchors. Free glycoinositol phospholipids (GIPLs) which are not linked to protein or phosphoglycan have also been found. In this study, we show that L. mexicana promastigotes synthesize two distinct GIPL lineages, comprising at least 10 glycolipid species. These structures were characterized using a combination of gas-liquid chromatography-mass spectrometry, methylation linkage analysis, and chemical and exoglycosidase sequencing. The major lineage contains GIPLs with the glycan structures Man alpha 1-3Man alpha 1-4GlcN (iM2), Man alpha 1-6(Man alpha 1-3)Man alpha 1-4GlcN (iM3), and Man alpha 1-2Man alpha 1-6(Man alpha 1-3)Man alpha 1-4GlcN (iM4), which are linked to alkylacyl-PI containing predominantly C16:0 and C18:0 fatty acids and C18:0 alkyl chains (referred to as the hybrid type GIPLs). A proportion of the iM3 and iM4 species (32 and 4%, respectively) are substituted with an ethanolamine-phosphate residue. The location of this residue on the core glucosamine residue was inferred from the results of methylation analyses and alpha-mannosidase digestion. The minor GIPL lineage contains GIPLs with the same glycan sequences as the glycolipid anchor of LPG (referred to as the type-2 GIPLs). The alkylacyl-PI or lyso-alkyl-PI lipid moieties of these GIPLs differ from those of the hybrid type GIPLs and from the main pool of alkylacyl-PI in containing significant levels of C24:0 and C26:0 alkyl chains. The most polar of these GIPLs, LPGp, has the properties expected of a biosynthetic precursor to the LPG, having the structure, [formula: see text] Finally, the GPI anchors of the major promastigote proteins were found to contain the glycan sequence Man alpha 1-2Man alpha 1-6Man alpha 1-4GlcN, and an alkylacyl-PI lipid moiety which

  3. Chromatographic separation of cholesterol in foods.

    Science.gov (United States)

    Fenton, M

    1992-10-30

    Based on the current literature and on experience gained in the laboratory, a simplified procedure using direct saponification (0.4 M potassium hydroxide in ethanol and heating at 60 degrees C for 1 h) is the most appropriate method for the determination of total cholesterol in foods. Extraction of the unsaponifiable matter with hexane is efficient and no extra clean-up is required before quantification. An internal standard, 5 alpha-cholestane or epicoprostanol, should be added to the sample prior to saponification and, together with reference standards, carried through the entire procedure to ensure accurate results. A significant improvement in cholesterol methodology has been achieved by decreasing the sample size and performing all the sample preparation steps in a single tube. The method has the advantages of elimination of an initial solvent extraction for total lipids and errors resulting from multiple extractions, transfers, filtration and wash steps after saponification. The resulting hexane extract, which contains a variety of sterols and fat soluble vitamins, requires an efficient capillary column for complete resolution of cholesterol from the other compounds present. The development of fused-silica capillary columns using cross-linked and bonded liquid phases has provided high thermal stability, inertness and separation efficiency and, together with automated cold on-column gas chromatographic injection systems, has resulted in reproducible cholesterol determinations in either underivatized or derivatized form. If free cholesterol and its esters need to be determined separately, they are initially extracted with other lipids with chloroform-methanol followed by their separation by column or thin-layer chromatography and subsequently analysed by gas or liquid chromatography. Although capillary gas chromatography offers superior efficiency in separation, the inherent benefits of liquid chromatography makes it a potential alternative. Isotope dilution

  4. Dairy products and plasma cholesterol levels

    Directory of Open Access Journals (Sweden)

    Lena Ohlsson

    2010-08-01

    Full Text Available Cholesterol synthesized in the body or ingested is an essential lipid component for human survival from our earliest life. Newborns ingest about 3–4 times the amount per body weight through mother's milk compared to the dietary intake of adults. A birth level of 1.7 mmol/L plasma total cholesterol will increase to 4–4.5 mmol/L during the nursing period and continue to increase from adulthood around 40% throughout life. Coronary artery disease and other metabolic disorders are strongly associated with low-density lipoprotein (LDL and high-density lipoprotein (HDL cholesterol as well as triacylglycerol concentration. Milk fat contains a broad range of fatty acids and some have a negative impact on the cholesterol rich lipoproteins. The saturated fatty acids (SFAs, such as palmitic acid (C16:0, myristic acid (C14:0, and lauric acid (C12:0, increase total plasma cholesterol, especially LDL, and constitute 11.3 g/L of bovine milk, which is 44.8% of total fatty acid in milk fat. Replacement of dairy SFA and trans-fatty acids with polyunsaturated fatty acids decreases plasma cholesterol, especially LDL cholesterol, and is associated with a reduced risk of cardiovascular disease. Available data shows different effects on lipoproteins for different dairy products and there is uncertainty as to the impact a reasonable intake amount of dairy items has on cardiovascular risk. The aim of this review is to elucidate the effect of milk components and dairy products on total cholesterol, LDL, HDL, and the LDL/HDL quotients. Based on eight recent randomized controlled trials of parallel or cross-over design and recent reviews it can be concluded that replacement of saturated fat mainly (but not exclusively derived from high-fat dairy products with low-fat dairy products lowers LDL/HDL cholesterol and total/HDL cholesterol ratios. Whey, dairy fractions enriched in polar lipids, and techniques such as fermentation, or fortification of cows feeding can be used

  5. Cholesterol and ocular pathologies: focus on the role of cholesterol-24S-hydroxylase in cholesterol homeostasis

    Directory of Open Access Journals (Sweden)

    Fourgeux Cynthia

    2015-03-01

    Full Text Available The retina is responsible for coding the light stimulus into a nervous signal that is transferred to the brain via the optic nerve. The retina is formed by the association of the neurosensory retina and the retinal pigment epithelium that is supported by Bruch’s membrane. Both the physical and metabolic associations between these partners are crucial for the functioning of the retina, by means of nutrient intake and removal of the cell and metabolic debris from the retina. Dysequilibrium are involved in the aging processes and pathologies such as age-related macular degeneration, the leading cause of visual loss after the age of 50 years in Western countries. The retina is composed of several populations of cells including glia that is involved in cholesterol biosynthesis. Cholesterol is the main sterol in the retina. It is present as free form in cells and as esters in Bruch’s membrane. Accumulation of cholesteryl esters has been associated with aging of the retina and impairment of the retinal function. Under dietary influence and in situ synthesized, the metabolism of cholesterol is regulated by cell interactions, including neurons and glia via cholesterol-24S-hydroxylase. Several pathophysiological associations with cholesterol and its metabolism can be suggested, especially in relation to glaucoma and age-related macular degeneration.

  6. Cholesterol efflux analyses using stable isotopes and mass spectrometry

    OpenAIRE

    Robert J Brown; Shao, Fei; Baldán, Ángel; Albert, Carolyn J.; Ford, David A.

    2012-01-01

    Cholesterol efflux from macrophages and the vascular wall is the initial step of the cardiovascular protective reverse cholesterol transport process. This study demonstrates a mass spectrometry based assay to measure the cellular and media content of [d7]-cholesterol and unlabeled cholesterol that can be used to measure cholesterol efflux from cell lines. Using a triple quadrupole ESI-MS instrument in direct infusion mode, product ion scanning for m/z 83, neutral loss (NL) 375.5 scanning and ...

  7. A novel alkyne cholesterol to trace cellular cholesterol metabolism and localization.

    Science.gov (United States)

    Hofmann, Kristina; Thiele, Christoph; Schött, Hans-Frieder; Gaebler, Anne; Schoene, Mario; Kiver, Yuriy; Friedrichs, Silvia; Lütjohann, Dieter; Kuerschner, Lars

    2014-03-01

    Cholesterol is an important lipid of mammalian cells and plays a fundamental role in many biological processes. Its concentration in the various cellular membranes differs and is tightly regulated. Here, we present a novel alkyne cholesterol analog suitable for tracing both cholesterol metabolism and localization. This probe can be detected by click chemistry employing various reporter azides. Alkyne cholesterol is accepted by cellular enzymes from different biological species (Brevibacterium, yeast, rat, human) and these enzymes include cholesterol oxidases, hydroxylases, and acyl transferases that generate the expected metabolites in in vitro and in vivo assays. Using fluorescence microscopy, we studied the distribution of cholesterol at subcellular resolution, detecting the lipid in the Golgi and at the plasma membrane, but also in the endoplasmic reticulum and mitochondria. In summary, alkyne cholesterol represents a versatile, sensitive, and easy-to-use tool for tracking cellular cholesterol metabolism and localization as it allows for manifold detection methods including mass spectrometry, thin-layer chromatography/fluorography, and fluorescence microscopy. PMID:24334219

  8. Emerging roles of the intestine in control of cholesterol metabolism

    Institute of Scientific and Technical Information of China (English)

    Janine K Kruit; Albert K Groen; Theo J van Berkel; Folkert Kuipers

    2006-01-01

    The liver is considered the major "control center" for maintenance of whole body cholesterol homeostasis. This organ is the main site for de novo cholesterol synthesis,clears cholesterol-containing chylomicron remnants and low density lipoprotein particles from plasma and is the major contributor to high density lipoprotein (HDL; good cholesterol) formation. The liver has a central position in the classical definition of the reverse cholesterol transport pathway by taking up peripheryderived cholesterol from lipoprotein particles followed by conversion into bile acids or its direct secretion into bile for eventual removal via the feces. During the past couple of years, however, an additional important role of the intestine in maintenance of cholesterol homeostasis and regulation of plasma cholesterol levels has become apparent. Firstly, molecular mechanisms of cholesterol absorption have been elucidated and novel pharmacological compounds have been identified that interfere with the process and positively impact plasma cholesterol levels. Secondly, it is now evident that the intestine itself contributes to fecal neutral sterol loss as a cholesterol-secreting organ. Finally, very recent work has unequivocally demonstrated that the intestine contributes significantly to plasma HDL cholesterol levels.Thus, the intestine is a potential target for novel antiatherosclerotic treatment strategies that, in addition to interference with cholesterol absorption, modulate direct cholesterol excretion and plasma HDL cholesterol levels.

  9. Trends in PDE constrained optimization

    CERN Document Server

    Benner, Peter; Engell, Sebastian; Griewank, Andreas; Harbrecht, Helmut; Hinze, Michael; Rannacher, Rolf; Ulbrich, Stefan

    2014-01-01

    Optimization problems subject to constraints governed by partial differential equations (PDEs) are among the most challenging problems in the context of industrial, economical and medical applications. Almost the entire range of problems in this field of research was studied and further explored as part of the Deutsche Forschungsgemeinschaft (DFG) priority program 1253 on “Optimization with Partial Differential Equations” from 2006 to 2013. The investigations were motivated by the fascinating potential applications and challenging mathematical problems that arise in the field of PDE constrained optimization. New analytic and algorithmic paradigms have been developed, implemented and validated in the context of real-world applications. In this special volume, contributions from more than fifteen German universities combine the results of this interdisciplinary program with a focus on applied mathematics.   The book is divided into five sections on “Constrained Optimization, Identification and Control”...

  10. Production and characterization of a glycolipid biosurfactant, mannosylerythritol lipid B, from sugarcane juice by Ustilago scitaminea NBRC 32730.

    Science.gov (United States)

    Morita, Tomotake; Ishibashi, Yuko; Hirose, Naoto; Wada, Koji; Takahashi, Makoto; Fukuoka, Tokuma; Imura, Tomohiro; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2011-01-01

    Mannosylerythritol lipids (MELs) are glycolipid biosurfactants excreted by fungal strains. They show not only excellent surface-active properties but also versatile biochemical actions. Ustilago scitaminea NBRC 32730 has been reported mainly to produce a mono-acetylated and di-acylated MEL, MEL-B, from sucrose as sole carbon source. In order to make biosurfactant production more efficient, we focused our attention on the use of sugarcane juice, one of the most economical resources. The fungal strain produced MEL-B at the yield of 12.7 g/L from only sugarcane juice containing 22.4% w/w sugars. Supplementation with organic (yeast extract, peptone, and urea) and inorganic (sodium nitrate and ammonium nitrate) nitrogen sources markedly enhanced the production yield. Of the nitrogen sources, urea gave the best yield. Under optimum conditions, the strain produced 25.1 g/L of MEL-B from the juice (19.3% sugars) supplemented with 1 g/L of urea in a jar fermenter at 25 °C over 7 d. The critical micelle concentration (CMC) and the surface-tension at the CMC for the present MEL-B were 3.7×10(-6) M and 25.2 mN/m respectively. On water-penetration scan, the biosurfactant efficiently formed the lamella phase (L(α)) and myelins over a wide range of concentrations, indicating excellent surface-active and self-assembling properties. More significantly, the biosurfactant showed a ceramide-like skin-care property in a three-dimensional cultured human skin model. Thus, sugarcane juice is likely to be effective in glycolipid production by U. scitaminea NBRC 32730, and should facilitate the application of MELs. PMID:21737925

  11. Dynamic micelles of mannoside glycolipids are more efficient than polymers for inhibiting HIV-1 trans-infection.

    Science.gov (United States)

    Schaeffer, Evelyne; Dehuyser, Laure; Sigwalt, David; Flacher, Vincent; Bernacchi, Serena; Chaloin, Olivier; Remy, Jean-Serge; Mueller, Christopher G; Baati, Rachid; Wagner, Alain

    2013-11-20

    Mannoside glycolipid conjugates are able to inhibit human immunodeficiency virus type 1 (HIV-1) trans-infection mediated by human dendritic cells (DCs). The conjugates are formed by three building blocks: a linear or branched mannose head, a hydrophilic linker, and a 24-carbon lipid chain. We have shown that, even as single molecules, these compounds efficiently target mannose-binding lectins, such as DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN) important for HIV-1 transmission. With the goal to optimize their inhibitory activity by supramolecular structure formation, we have compared saturated and unsaturated conjugates, as single molecules, self-assemblies of dynamic micelles, and photopolymerized cross-linked polymers. Surface plasmon resonance showed that, unexpectedly, polymers of trivalent conjugates did not display a higher binding affinity for DC-SIGN than single molecules. Interactions on a chip or in solution were independent of calcium; however, binding to DCs was inhibited by a calcium chelator. Moreover, HIV-1 trans-infection was mostly inhibited by dynamic micelles and not by rigid polymers. The inhibition data revealed a clear correlation between the structure and molecular assembly of a conjugate and its biological antiviral activity. We present an interaction model between DC-SIGN and conjugates-either single molecules, micelles, or polymers-that highlights that the most effective interactions by dynamic micelles involve both mannose heads and lipid chains. Our data reveal that trivalent glycolipid conjugates display the highest microbicide potential for HIV prophylaxis, as dynamic micelles conjugates and not as rigid polymers. PMID:24134734

  12. IDENTIFICATION OF PSEUDOZYMA HUBEIENSIS Y10BS025 AS A POTENT PRODUCER OF GLYCOLIPID BIOSURFACTANT MANNOSYLERYTHRITOL LIPIDS

    Directory of Open Access Journals (Sweden)

    Martha Sari

    2013-01-01

    Full Text Available Mannosylerythritol Lipids (MEL’s are glycolipid biosurfactants that contain 4-O-β-D-mannopyranosyl-meso-erythritol as a hydrophilic moiety and fatty acids as a hydrophobic moiety. MEL’s are abundantly produced by several kinds of microorganism and are one of the most promising biosurfactants currently known. The search for a novel endogenous producer of MEL’s was undertaken based on the available collection of the yeast strains from the genus Pseudozyma. Using thin layer chromatography and based on morphological and molecular taxonomic analysis using the D1/D2 domains of the large subunit 26S rRNA gene, Pseudozyma hubeiensis Y10BS025 was found to be a potential producer of MEL’s from soybean oil. The structure of the major glycolipid produced by the strain was analyzed by 1H and 13C nuclear magnetic resonance and was found to be similar to those of well known MEL-A, -B and -C respectively. Under improved shaking culture conditions, using yeast extract as nitrogen source and soybean oil as substrate, a maximum yield of 115±3.2 g.L-1 of MEL’s for 8 days of fermentation was achieved. The major fatty acids of MEL’s produced by P. hubeiensis Y10BS025 were C-18 acids, considerably different from those of MEL-C produced by other Pseudozyma strains such as P. antarctica and P. shanxiensis. The main product, MEL-C produced by P. hubeiensis Y10BS025 exhibited surface-tension-lowering activity. The results demonstrated that the newly isolated P. hubeiensis Y10BS025 provided high efficiency in MEL’s production and would thus be highly advantageous in commercial production of promising biosurfactants.

  13. [Trans-intestinal cholesterol excretion (TICE): a new route for cholesterol excretion].

    Science.gov (United States)

    Blanchard, Claire; Moreau, François; Cariou, Bertrand; Le May, Cédric

    2014-10-01

    The small intestine plays a crucial role in dietary and biliary cholesterol absorption, as well as its lymphatic secretion as chylomicrons (lipoprotein exogenous way). Recently, a new metabolic pathway called TICE (trans-intestinal excretion of cholesterol) that plays a central role in cholesterol metabolism has emerged. TICE is an inducible way, complementary to the hepatobiliary pathway, allowing the elimination of the plasma cholesterol directly into the intestine lumen through the enterocytes. This pathway is poorly characterized but several molecular actors of TICE have been recently identified. Although it is a matter of debate, two independent studies suggest that TICE is involved in the anti-atherogenic reverse cholesterol transport pathway. Thus, TICE is an innovative drug target to reduce -cardiovascular diseases.

  14. Impulsive differential inclusions with constrains

    Directory of Open Access Journals (Sweden)

    Tzanko Donchev

    2006-05-01

    Full Text Available In the paper, we study weak invariance of differential inclusions with non-fixed time impulses under compactness type assumptions. When the right-hand side is one sided Lipschitz an extension of the well known relaxation theorem is proved. In this case also necessary and sufficient condition for strong invariance of upper semi continuous systems are obtained. Some properties of the solution set of impulsive system (without constrains in appropriate topology are investigated.

  15. Constrained ballistics and geometrical optics

    OpenAIRE

    Epstein, Marcelo

    2014-01-01

    The problem of constant-speed ballistics is studied under the umbrella of non-linear non-holonomic constrained systems. The Newtonian approach is shown to be equivalent to the use of Chetaev's rule to incorporate the constraint within the initially unconstrained formulation. Although the resulting equations are not, in principle, obtained from a variational statement, it is shown that the trajectories coincide with those of geometrical optics in a medium with a suitably chosen refractive inde...

  16. Lipoproteins, cholesterol homeostasis and cardiac health

    Directory of Open Access Journals (Sweden)

    Tyler F. Daniels, Karen M. Killinger, Jennifer J. Michal, Raymond W. Wright Jr., Zhihua Jiang

    2009-01-01

    Full Text Available Cholesterol is an essential substance involved in many functions, such as maintaining cell membranes, manufacturing vitamin D on surface of the skin, producing hormones, and possibly helping cell connections in the brain. When cholesterol levels rise in the blood, they can, however, have dangerous consequences. In particular, cholesterol has generated considerable notoriety for its causative role in atherosclerosis, the leading cause of death in developed countries around the world. Homeostasis of cholesterol is centered on the metabolism of lipoproteins, which mediate transport of the lipid to and from tissues. As a synopsis of the major events and proteins that manage lipoprotein homeostasis, this review contributes to the substantial attention that has recently been directed to this area. Despite intense scrutiny, the majority of phenotypic variation in total cholesterol and related traits eludes explanation by current genetic knowledge. This is somewhat disappointing considering heritability estimates have established these traits as highly genetic. Thus, the continued search for candidate genes, mutations, and mechanisms is vital to our understanding of heart disease at the molecular level. Furthermore, as marker development continues to predict risk of vascular illness, this knowledge has the potential to revolutionize treatment of this leading human disease.

  17. LDL cholesterol: controversies and future therapeutic directions.

    Science.gov (United States)

    Ridker, Paul M

    2014-08-16

    Lifelong exposure to raised concentrations of LDL cholesterol increases cardiovascular event rates, and the use of statin therapy as an adjunct to diet, exercise, and smoking cessation has proven highly effective in reducing the population burden associated with hyperlipidaemia. Yet, despite consistent biological, genetic, and epidemiological data, and evidence from randomised trials, there is controversy among national guidelines and clinical practice with regard to LDL cholesterol, its measurement, the usefulness of population-based screening, the net benefit-to-risk ratio for different LDL-lowering drugs, the benefit of treatment targets, and whether aggressive lowering of LDL is safe. Several novel therapies have been introduced for the treatment of people with genetic defects that result in loss of function within the LDL receptor, a major determinant of inherited hyperlipidaemias. Moreover, the usefulness of monoclonal antibodies that extend the LDL-receptor lifecycle (and thus result in substantial lowering of LDL cholesterol below the levels achieved with statins alone) is being assessed in phase 3 trials that will enrol more than 60,000 at-risk patients worldwide. These trials represent an exceptionally rapid translation of genetic observations into clinical practice and will address core questions of how low LDL cholesterol can be safely reduced, whether the mechanism of LDL-cholesterol lowering matters, and whether ever more aggressive lipid-lowering provides a safe, long-term mechanism to prevent atherothrombotic complications.

  18. Increased plasma membrane cholesterol in cystic fibrosis cells correlates with CFTR genotype and depends on de novo cholesterol synthesis

    OpenAIRE

    Sonawane Nitin D; Previs Stephen F; Jiang Dechen; Ruddy Jennifer; Manson Mary E; West Richard H; Fang Danjun; Burgess James D; Kelley Thomas J

    2010-01-01

    Abstract Background Previous observations demonstrate that Cftr-null cells and tissues exhibit alterations in cholesterol processing including perinuclear cholesterol accumulation, increased de novo synthesis, and an increase in plasma membrane cholesterol accessibility compared to wild type controls. The hypothesis of this study is that membrane cholesterol accessibility correlates with CFTR genotype and is in part influenced by de novo cholesterol synthesis. Methods Electrochemical detectio...

  19. Elevated Remnant Cholesterol Causes Both Low-Grade Inflammation and Ischemic Heart Disease, Whereas Elevated Low-Density Lipoprotein Cholesterol Causes Ischemic Heart Disease Without Inflammation

    DEFF Research Database (Denmark)

    Varbo, Anette; Tybjærg-Hansen, Anne; Nordestgaard, Børge G;

    2013-01-01

    Elevated nonfasting remnant cholesterol and low-density lipoprotein (LDL) cholesterol are causally associated with ischemic heart disease (IHD), but whether elevated nonfasting remnant cholesterol and LDL cholesterol both cause low-grade inflammation is currently unknown....

  20. Dietary cholesterol from eggs increases the ratio of total cholesterol to high-density lipoprotein cholesterol in humans : a meta-analysis

    NARCIS (Netherlands)

    Weggemans, R.M.; Zock, P.L.; Katan, M.B.

    2001-01-01

    Several epidemiologic studies found no effect of egg consumption on the risk of coronary heart disease. It is possible that the adverse effect of eggs on LDL-cholesterol is offset by their favorable effect on HDL cholesterol. Objective: The objective was to review the effect of dietary cholesterol o

  1. CHOBIMALT: A Cholesterol-Based Detergent†

    Science.gov (United States)

    Howell, Stanley C.; Mittal, Ritesh; Huang, Lijun; Travis, Benjamin; Breyer, Richard M.; Sanders, Charles R.

    2010-01-01

    Cholesterol and its hemisuccinate and sulfate derivatives are widely used in studies of purified membrane proteins, but are difficult to solubilize in aqueous solution, even in the presence of detergent micelles. Other cholesterol derivatives do not form conventional micelles and lead to viscous solutions. To address these problems a cholesterol-based detergent, CHOBIMALT, has been synthesized and characterized. At concentrations above 3–4μM, CHOBIMALT forms micelles without the need for elevated temperatures or sonic disruption. Diffusion and fluorescence measurements indicated that CHOBIMALT micelles are large (210 ± 30 kDa). The ability to solubilize a functional membrane protein was explored using a G-protein coupled receptor, the human kappa opioid receptor type 1 (hKOR1). While CHOBIMALT alone was not found to be effective as a surfactant for membrane extraction, when added to classical detergent micelles CHOBIMALT was observed to dramatically enhance the thermal stability of solubilized hKOR1. PMID:20919740

  2. CHOBIMALT: a cholesterol-based detergent.

    Science.gov (United States)

    Howell, Stanley C; Mittal, Ritesh; Huang, Lijun; Travis, Benjamin; Breyer, Richard M; Sanders, Charles R

    2010-11-01

    Cholesterol and its hemisuccinate and sulfate derivatives are widely used in studies of purified membrane proteins but are difficult to solubilize in aqueous solution, even in the presence of detergent micelles. Other cholesterol derivatives do not form conventional micelles and lead to viscous solutions. To address these problems, a cholesterol-based detergent, CHOBIMALT, has been synthesized and characterized. At concentrations above 3−4 μM, CHOBIMALT forms micelles without the need for elevated temperatures or sonic disruption. Diffusion and fluorescence measurements indicated that CHOBIMALT micelles are large (210±30 kDa). The ability to solubilize a functional membrane protein was explored using a G-protein coupled receptor, the human kappa opioid receptor type 1 (hKOR1). While CHOBIMALT alone was not found to be effective as a surfactant for membrane extraction, when added to classical detergent micelles CHOBIMALT was observed to dramatically enhance the thermal stability of solubilized hKOR1.

  3. Aspirin Increases the Solubility of Cholesterol in Lipid Membranes

    Science.gov (United States)

    Alsop, Richard; Barrett, Matthew; Zheng, Sonbo; Dies, Hannah; Rheinstadter, Maikel

    2014-03-01

    Aspirin (ASA) is often prescribed for patients with high levels of cholesterol for the secondary prevention of myocardial events, a regimen known as the Low-Dose Aspirin Therapy. We have recently shown that Aspirin partitions in lipid bilayers. However, a direct interplay between ASA and cholesterol has not been investigated. Cholesterol is known to insert itself into the membrane in a dispersed state at moderate concentrations (under ~37.5%) and decrease fluidity of membranes. We prepared model lipid membranes containing varying amounts of both ASA and cholesterol molecules. The structure of the bilayers as a function of ASA and cholesterol concentration was determined using high-resolution X-ray diffraction. At cholesterol levels of more than 40mol%, immiscible cholesterol plaques formed. Adding ASA to the membranes was found to dissolve the cholesterol plaques, leading to a fluid lipid bilayer structure. We present first direct evidence for an interaction between ASA and cholesterol on the level of the cell membrane.

  4. Increased plasma membrane cholesterol in cystic fibrosis cells correlates with CFTR genotype and depends on de novo cholesterol synthesis

    Directory of Open Access Journals (Sweden)

    Sonawane Nitin D

    2010-05-01

    Full Text Available Abstract Background Previous observations demonstrate that Cftr-null cells and tissues exhibit alterations in cholesterol processing including perinuclear cholesterol accumulation, increased de novo synthesis, and an increase in plasma membrane cholesterol accessibility compared to wild type controls. The hypothesis of this study is that membrane cholesterol accessibility correlates with CFTR genotype and is in part influenced by de novo cholesterol synthesis. Methods Electrochemical detection of cholesterol at the plasma membrane is achieved with capillary microelectrodes with a modified platinum coil that accepts covalent attachment of cholesterol oxidase. Modified electrodes absent cholesterol oxidase serves as a baseline control. Cholesterol synthesis is determined by deuterium incorporation into lipids over time. Incorporation into cholesterol specifically is determined by mass spectrometry analysis. All mice used in the study are on a C57Bl/6 background and are between 6 and 8 weeks of age. Results Membrane cholesterol measurements are elevated in both R117H and ΔF508 mouse nasal epithelium compared to age-matched sibling wt controls demonstrating a genotype correlation to membrane cholesterol detection. Expression of wt CFTR in CF epithelial cells reverts membrane cholesterol to WT levels further demonstrating the impact of CFTR on these processes. In wt epithelial cell, the addition of the CFTR inhibitors, Gly H101 or CFTRinh-172, for 24 h surprisingly results in an initial drop in membrane cholesterol measurement followed by a rebound at 72 h suggesting a feedback mechanism may be driving the increase in membrane cholesterol. De novo cholesterol synthesis contributes to membrane cholesterol accessibility. Conclusions The data in this study suggest that CFTR influences cholesterol trafficking to the plasma membrane, which when depleted, leads to an increase in de novo cholesterol synthesis to restore membrane content.

  5. The cholesterol system of the swine

    International Nuclear Information System (INIS)

    The purpose of this work was to characterize the dynamic system of adult female Large White swine. The content of this system and its relationships with both the external environment and between the different parts of the system were explained. The analysis of these results in terms of compared physiology showed that the structure of the cholesterol system was the same in man and in the swine. Consequently, the swine constitutes a good biological tool to study human cholesterol indirectly and to foresee the changes that might be induced in various physio-pathological cases. (author)

  6. Ordering effects of cholesterol and its analogues

    DEFF Research Database (Denmark)

    Róg, Tomasz; Pasenkiewicz-Gierula, Marta; Vattulainen, Ilpo;

    2009-01-01

    . In this review, we discuss the biophysical effects of cholesterol on the lipid bilayer, in particular the ordering and condensing effects, concentrating on the molecular level or inter-atomic interactions perspective, starting from two-component systems and proceeding to many-component ones e.g., modeling lipid...... rafts. Particular attention is paid to the roles of the methyl groups in the cholesterol ring system, and their possible biological function. Although our main research methodology is computer modeling, in this review we make extensive comparisons between experiments and different modeling approaches....

  7. Electron Transfer Pathways in Cholesterol Synthesis.

    Science.gov (United States)

    Porter, Todd D

    2015-10-01

    Cholesterol synthesis in the endoplasmic reticulum requires electron input at multiple steps and utilizes both NADH and NADPH as the electron source. Four enzymes catalyzing five steps in the pathway require electron input: squalene monooxygenase, lanosterol demethylase, sterol 4α-methyl oxidase, and sterol C5-desaturase. The electron-donor proteins for these enzymes include cytochrome P450 reductase and the cytochrome b5 pathway. Here I review the evidence for electron donor protein requirements with these enzymes, the evidence for additional electron donor pathways, and the effect of deletion of these redox enzymes on cholesterol and lipid metabolism. PMID:26344922

  8. Intestinal SR-BI does not impact cholesterol absorption or transintestinal cholesterol efflux in mice.

    Science.gov (United States)

    Bura, Kanwardeep S; Lord, Caleb; Marshall, Stephanie; McDaniel, Allison; Thomas, Gwyn; Warrier, Manya; Zhang, Jun; Davis, Matthew A; Sawyer, Janet K; Shah, Ramesh; Wilson, Martha D; Dikkers, Arne; Tietge, Uwe J F; Collet, Xavier; Rudel, Lawrence L; Temel, Ryan E; Brown, J Mark

    2013-06-01

    Reverse cholesterol transport (RCT) can proceed through the classic hepatobiliary route or through the nonbiliary transintestinal cholesterol efflux (TICE) pathway. Scavenger receptor class B type I (SR-BI) plays a critical role in the classic hepatobiliary route of RCT. However, the role of SR-BI in TICE has not been studied. To examine the role of intestinal SR-BI in TICE, sterol balance was measured in control mice and mice transgenically overexpressing SR-BI in the proximal small intestine (SR-BI(hApoCIII-ApoAIV-Tg)). SR-BI(hApoCIII-ApoAIV-Tg) mice had significantly lower plasma cholesterol levels compared with wild-type controls, yet SR-BI(hApoCIII-ApoAIV-Tg) mice had normal fractional cholesterol absorption and fecal neutral sterol excretion. Both in the absence or presence of ezetimibe, intestinal SR-BI overexpression had no impact on the amount of cholesterol excreted in the feces. To specifically study effects of intestinal SR-BI on TICE we crossed SR-BI(hApoCIII-ApoAIV-Tg) mice into a mouse model that preferentially utilized the TICE pathway for RCT (Niemann-Pick C1-like 1 liver transgenic), and likewise found no alterations in cholesterol absorption or fecal sterol excretion. Finally, mice lacking SR-BI in all tissues also exhibited normal cholesterol absorption and fecal cholesterol disposal. Collectively, these results suggest that SR-BI is not rate limiting for intestinal cholesterol absorption or for fecal neutral sterol loss through the TICE pathway.

  9. Cholesterol homeostasis: How do cells sense sterol excess?

    Science.gov (United States)

    Howe, Vicky; Sharpe, Laura J; Alexopoulos, Stephanie J; Kunze, Sarah V; Chua, Ngee Kiat; Li, Dianfan; Brown, Andrew J

    2016-09-01

    Cholesterol is vital in mammals, but toxic in excess. Consequently, elaborate molecular mechanisms have evolved to maintain this sterol within narrow limits. How cells sense excess cholesterol is an intriguing area of research. Cells sense cholesterol, and other related sterols such as oxysterols or cholesterol synthesis intermediates, and respond to changing levels through several elegant mechanisms of feedback regulation. Cholesterol sensing involves both direct binding of sterols to the homeostatic machinery located in the endoplasmic reticulum (ER), and indirect effects elicited by sterol-dependent alteration of the physical properties of membranes. Here, we examine the mechanisms employed by cells to maintain cholesterol homeostasis. PMID:26993747

  10. Remnant cholesterol as a cause of ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Nordestgaard, Børge G

    2014-01-01

    levels of remnant cholesterol may cause atherosclerosis same way as elevated levels of low-density lipoprotein (LDL) cholesterol, by cholesterol accumulation in the arterial wall. Genetic studies of variants associated with elevated remnant cholesterol levels show that an increment of 1mmol/L (39mg....... However, elevated levels of LDL cholesterol are associated with IHD, but not with low-grade inflammation. Such results indicate that elevated LDL cholesterol levels cause atherosclerosis without a major inflammatory component, whereas an inflammatory component of atherosclerosis is driven by elevated...

  11. Histone deacetylase inhibition decreases cholesterol levels in neuronal cells by modulating key genes in cholesterol synthesis, uptake and efflux.

    Directory of Open Access Journals (Sweden)

    Maria João Nunes

    Full Text Available Cholesterol is an essential component of the central nervous system and increasing evidence suggests an association between brain cholesterol metabolism dysfunction and the onset of neurodegenerative disorders. Interestingly, histone deacetylase inhibitors (HDACi such as trichostatin A (TSA are emerging as promising therapeutic approaches in neurodegenerative diseases, but their effect on brain cholesterol metabolism is poorly understood. We have previously demonstrated that HDACi up-regulate CYP46A1 gene transcription, a key enzyme in neuronal cholesterol homeostasis. In this study, TSA was shown to modulate the transcription of other genes involved in cholesterol metabolism in human neuroblastoma cells, namely by up-regulating genes that control cholesterol efflux and down-regulating genes involved in cholesterol synthesis and uptake, thus leading to an overall decrease in total cholesterol content. Furthermore, co-treatment with the amphipathic drug U18666A that can mimic the intracellular cholesterol accumulation observed in cells of Niemman-Pick type C patients, revealed that TSA can ameliorate the phenotype induced by pathological cholesterol accumulation, by restoring the expression of key genes involved in cholesterol synthesis, uptake and efflux and promoting lysosomal cholesterol redistribution. These results clarify the role of TSA in the modulation of neuronal cholesterol metabolism at the transcriptional level, and emphasize the idea of HDAC inhibition as a promising therapeutic tool in neurodegenerative disorders with impaired cholesterol metabolism.

  12. Constraining Lorentz violation with cosmology.

    Science.gov (United States)

    Zuntz, J A; Ferreira, P G; Zlosnik, T G

    2008-12-31

    The Einstein-aether theory provides a simple, dynamical mechanism for breaking Lorentz invariance. It does so within a generally covariant context and may emerge from quantum effects in more fundamental theories. The theory leads to a preferred frame and can have distinct experimental signatures. In this Letter, we perform a comprehensive study of the cosmological effects of the Einstein-aether theory and use observational data to constrain it. Allied to previously determined consistency and experimental constraints, we find that an Einstein-aether universe can fit experimental data over a wide range of its parameter space, but requires a specific rescaling of the other cosmological densities. PMID:19113765

  13. Constrained Stochastic Extended Redundancy Analysis.

    Science.gov (United States)

    DeSarbo, Wayne S; Hwang, Heungsun; Stadler Blank, Ashley; Kappe, Eelco

    2015-06-01

    We devise a new statistical methodology called constrained stochastic extended redundancy analysis (CSERA) to examine the comparative impact of various conceptual factors, or drivers, as well as the specific predictor variables that contribute to each driver on designated dependent variable(s). The technical details of the proposed methodology, the maximum likelihood estimation algorithm, and model selection heuristics are discussed. A sports marketing consumer psychology application is provided in a Major League Baseball (MLB) context where the effects of six conceptual drivers of game attendance and their defining predictor variables are estimated. Results compare favorably to those obtained using traditional extended redundancy analysis (ERA). PMID:24327066

  14. The Success Story of LDL Cholesterol Lowering.

    Science.gov (United States)

    Pedersen, Terje R

    2016-02-19

    We can look back at >100 years of cholesterol research that has brought medicine to a stage where people at risk of severe or fatal coronary heart disease have a much better prognosis than before. This progress has not come about without resistance. Perhaps one of the most debated topics in medicine, the cholesterol controversy, could only be brought to rest through the development of new clinical research methods that were capable of taking advantage of the amazing achievements in basic and pharmacological science after the second World War. It was only after understanding the biochemistry and physiology of cholesterol synthesis, transport and clearance from the blood that medicine could take advantage of drugs and diets to reduce the risk of atherosclerotic diseases. This review points to the highlights of the history of low-density lipoprotein-cholesterol lowering, with the discovery of the low-density lipoprotein receptor and its physiology and not only the development of statins as the stellar moments but also the development of clinical trial methodology as an effective tool to provide scientifically convincing evidence. PMID:26892969

  15. Mitochondria, cholesterol and cancer cell metabolism.

    Science.gov (United States)

    Ribas, Vicent; García-Ruiz, Carmen; Fernández-Checa, José C

    2016-12-01

    Given the role of mitochondria in oxygen consumption, metabolism and cell death regulation, alterations in mitochondrial function or dysregulation of cell death pathways contribute to the genesis and progression of cancer. Cancer cells exhibit an array of metabolic transformations induced by mutations leading to gain-of-function of oncogenes and loss-of-function of tumor suppressor genes that include increased glucose consumption, reduced mitochondrial respiration, increased reactive oxygen species generation and cell death resistance, all of which ensure cancer progression. Cholesterol metabolism is disturbed in cancer cells and supports uncontrolled cell growth. In particular, the accumulation of cholesterol in mitochondria emerges as a molecular component that orchestrates some of these metabolic alterations in cancer cells by impairing mitochondrial function. As a consequence, mitochondrial cholesterol loading in cancer cells may contribute, in part, to the Warburg effect stimulating aerobic glycolysis to meet the energetic demand of proliferating cells, while protecting cancer cells against mitochondrial apoptosis due to changes in mitochondrial membrane dynamics. Further understanding the complexity in the metabolic alterations of cancer cells, mediated largely through alterations in mitochondrial function, may pave the way to identify more efficient strategies for cancer treatment involving the use of small molecules targeting mitochondria, cholesterol homeostasis/trafficking and specific metabolic pathways. PMID:27455839

  16. [Giant cholesterol cysts of the petrous apex].

    Science.gov (United States)

    Pellet, W; Valenzuela, S; Malca, S; Cannoni, M; Perez-Castillo, A M

    1992-01-01

    In connection with their two own cases, the authors deal about the giant cholesterol cysts of the petrous apex. The lesions which are to be differentiated from epidermoid cysts are cholesterol granulomas. Their petrous apex location explains their characteristic large appearance. As each cholesterol granuloma, they occur when a bony cell is obstructed. This chronic obstruction induces mucosal edema then bleedings which lead to the formation and, by the lack of drainage, to the accumulation of cholesterol crystals. These crystals initiate a non specific reaction to foreign bodies, a granuloma, which also can bleed. Thus, a continuous cycle perpetuates the growth of the lesion. This lesion, when it is localized in the petrous apex, can reach a big size before the appearance of some signs. Usually, these are otologic (sensorineural hearing loss, tinnitus, vertigo) and/or cranial nerve palsies (V, VI, VII). C.T. scan (well defined, sharply marginated bony expansible lesion with isodense to the brain central part) and M.R.I. (central region of increased intensity on both T1 and T2 weighted images and peripheral rim of markedly decreased signal intensity in all instances) features are characteristic enough to allow diagnose with other petrous apex lesions (cholesteatoma, mucocele, epithelial cyst, histiocytosis X, ...). Surgical treatment must try to evacuate and to aerate the cavity or perhaps to obliterate it with fatty pieces in order to prevent the recurrence. PMID:1299772

  17. Quantum Annealing for Constrained Optimization

    Science.gov (United States)

    Hen, Itay; Spedalieri, Federico M.

    2016-03-01

    Recent advances in quantum technology have led to the development and manufacturing of experimental programmable quantum annealers that promise to solve certain combinatorial optimization problems of practical relevance faster than their classical analogues. The applicability of such devices for many theoretical and real-world optimization problems, which are often constrained, is severely limited by the sparse, rigid layout of the devices' quantum bits. Traditionally, constraints are addressed by the addition of penalty terms to the Hamiltonian of the problem, which, in turn, requires prohibitively increasing physical resources while also restricting the dynamical range of the interactions. Here, we propose a method for encoding constrained optimization problems on quantum annealers that eliminates the need for penalty terms and thereby reduces the number of required couplers and removes the need for minor embedding, greatly reducing the number of required physical qubits. We argue the advantages of the proposed technique and illustrate its effectiveness. We conclude by discussing the experimental feasibility of the suggested method as well as its potential to appreciably reduce the resource requirements for implementing optimization problems on quantum annealers and its significance in the field of quantum computing.

  18. Fluorimetric determination of cholesterol in hypercholesterolemia serum

    Science.gov (United States)

    Lan, Xiufeng; Liu, Jiangang; Liu, Ying; Luo, Xiaosen; Lu, Jian; Ni, Xiaowu

    2005-01-01

    With the increase of people"s living standard and the changes of living form, the number of people who suffer from hypercholesterolemia is increasing. It is not only harmful to heart and blood vessel, but also leading to obstruction of cognition. The conventional blood detection technology has weakness such as complex operation, long detecting period, and bad visibility. In order to develop a new detection method that can checkout hypercholesterolemia conveniently, spectroscopy of cholesterol in hypercholesterolemia serum is obtained by the multifunctional grating spectrograph. The experiment results indicate that, under the excitation of light-emitting diode (LED) with the wavelength at 407 nm, the serum from normal human and the hypercholesterolemia serum emit different fluorescence spectra. The former can emit one fluorescence region with the peak locating at 516 nm while the latter can emit two more regions with peaks locating at 560 nm and 588 nm. Moreover, the fluorescence intensity of serum is non-linear increasing with the concentration of cholesterol increases when the concentration of cholesterol is lower than 13.8 mmol/L, and then, with the concentration of cholesterol increase, the fluorescence intensity decreases. However, the fluorescence intensity is still much higher than that of serum from normal human. Conclusions can be educed from the experiments: the intensity and the shape of fluorescence spectra of hypercholesterolemia serum are different of those of normal serum, from which the cholesterol abnormal in blood can be judged. The consequences in this paper may offer an experimental reference for the diagnosis of the hypercholesterolemia.

  19. Enzymatic Quantification of Cholesterol and Cholesterol Esters from Silicone Hydrogel Contact Lenses

    OpenAIRE

    Pucker, Andrew D.; Thangavelu, Mirunalni; Nichols, Jason J.

    2010-01-01

    There is significant interest in lipid deposition associated with current silicone hydrogel contact lens materials. This work describes the application of a cholesterol assay used to examine this question.

  20. Increased Synthesis of Anti-Tuberculous Glycolipid Immunoglobulin G (IgG) and IgA with Cavity Formation in Patients with Pulmonary Tuberculosis▿

    OpenAIRE

    Mizusawa, Masako; Kawamura, Mizuoho; Takamori, Mikio; Kashiyama, Tetsuya; Fujita, Akira; Usuzawa, Motoki; Saitoh, Hiroki; Ashino, Yugo; Yano, Ikuya; Hattori, Toshio

    2008-01-01

    Tuberculous glycolipid (TBGL) antigen is a cell wall component of Mycobacterium tuberculosis and has been used for the serodiagnosis of tuberculosis. We investigated correlations between the levels of anti-TBGL antibodies and a variety of laboratory markers that are potentially influenced by tuberculous infection. Comparisons between patients with cavitary lesions and those without cavitary lesions were also made in order to determine the mechanism underlying the immune response to TBGL. Bloo...

  1. Analysis of NMR spectra of sugar chains of glycolipids by multiple relayed COSY and 2D homonuclear Hartman-Hahn spectroscopy

    International Nuclear Information System (INIS)

    The authors applied multiple relayed COSY and 2D homonuclear Hartman-Hahn spectroscopy to globoside, a glycolipid purified from human red blood cells. The subspectra corresponding to individual sugar components were extracted even from overlapping proton resonances by taking the cross sections of 2D spectra parallel to the F2 axis at anomeric proton resonances, so that unambiguous assignments of sugar proton resonances were accomplished. (Auth.)

  2. Hearing Outcomes after Surgical Drainage of Petrous Apex Cholesterol Granuloma

    OpenAIRE

    Rihani, Jordan; Kutz, J. Walter; Isaacson, Brandon

    2014-01-01

    Objective This study aims to assess the hearing outcomes of patients undergoing surgical management of petrous apex cholesterol granuloma and to discuss the role of otic capsule–sparing approaches in drainage of petrous apex cholesterol granulomas.

  3. Plasma Ubiquinone, Alpha-Tocopherol and Cholesterol in Man

    DEFF Research Database (Denmark)

    Karlsson, Jan; Diamant, Bertil; Edlund, Per Olof;

    1992-01-01

    Farmakologi, Coenzyme Q10, free cholesterol, vitamin E, antioxidants, Alpha-Tocopherol, vitamin Q, plasma, LDL-particle......Farmakologi, Coenzyme Q10, free cholesterol, vitamin E, antioxidants, Alpha-Tocopherol, vitamin Q, plasma, LDL-particle...

  4. Nonfasting triglycerides, cholesterol, and ischemic stroke in the general population

    DEFF Research Database (Denmark)

    Varbo, Anette; Nordestgaard, Børge G; Tybjaerg-Hansen, Anne;

    2011-01-01

    Current guidelines on stroke prevention have recommendations on desirable cholesterol levels, but not on nonfasting triglycerides. We compared stepwise increasing levels of nonfasting triglycerides and cholesterol for their association with risk of ischemic stroke in the general population....

  5. Trans Fat Now Listed With Saturated Fat and Cholesterol

    Science.gov (United States)

    ... Trans Fat Now Listed With Saturated Fat and Cholesterol Share Tweet Linkedin Pin it More sharing options ... I Do About Saturated Fat, Trans Fat, and Cholesterol? When comparing foods, look at the Nutrition Facts ...

  6. Talk with Your Health Care Provider about High Cholesterol

    Science.gov (United States)

    ... you do? Always ask your provider what your cholesterol numbers are and write them down. Discuss these ... provider may prescribe medicine to help lower your cholesterol. y y Take your medicine every day, or ...

  7. Ezetimibe and Simvastatin Reduce Cholesterol Levels in Zebrafish Larvae Fed a High-Cholesterol Diet

    Directory of Open Access Journals (Sweden)

    Ji Sun Baek

    2012-01-01

    Full Text Available Cholesterol-fed zebrafish is an emerging animal model to study metabolic, oxidative, and inflammatory vascular processes relevant to pathogenesis of human atherosclerosis. Zebrafish fed a high-cholesterol diet (HCD develop hypercholesterolemia and are characterized by profound lipoprotein oxidation and vascular lipid accumulation. Using optically translucent zebrafish larvae has the advantage of monitoring vascular pathology and assessing the efficacy of drug candidates in live animals. Thus, we investigated whether simvastatin and ezetimibe, the principal drugs used in management of hypercholesterolemia in humans, would also reduce cholesterol levels in HCD-fed zebrafish larvae. We found that ezetimibe was well tolerated by zebrafish and effectively reduced cholesterol levels in HCD-fed larvae. In contrast, simvastatin added to water was poorly tolerated by zebrafish larvae and, when added to food, had little effect on cholesterol levels in HCD-fed larvae. Combination of low doses of ezetimibe and simvastatin had an additive effect in reducing cholesterol levels in zebrafish. These results suggest that ezetimibe exerts in zebrafish a therapeutic effect similar to that in humans and that the hypercholesterolemic zebrafish can be used as a low-cost and informative model for testing new drug candidates and for investigating mechanisms of action for existing drugs targeting dyslipidemia.

  8. Bacterial CD1d-restricted glycolipids induce IL-10 production by human regulatory T cells upon cross-talk with invariant NKT cells.

    Science.gov (United States)

    Venken, Koen; Decruy, Tine; Aspeslagh, Sandrine; Van Calenbergh, Serge; Lambrecht, Bart N; Elewaut, Dirk

    2013-09-01

    Invariant NKT (iNKT) cells and CD4(+)CD25(+)FOXP3(+) regulatory T cells (Tregs) are important immune regulatory T cells with Ag reactivity to glycolipids and peptides, respectively. However, the functional interplay between these cells in humans is poorly understood. We show that Tregs suppress iNKT cell proliferation induced by CD1d-restricted glycolipids, including bacterial-derived diacylglycerols, as well as by innate-like activation. Inhibition was related to the potency of iNKT agonists, making diacylglycerol iNKT responses very prone to suppression. Cytokine production by iNKT cells was differentially modulated by Tregs because IL-4 production was reduced more profoundly compared with IFN-γ. A compelling observation was the significant production of IL-10 by Tregs after cell contact with iNKT cells, in particular in the presence of bacterial diacylglycerols. These iNKT-primed Tregs showed increased FOXP3 expression and superior suppressive function. Suppression of iNKT cell responses, but not conventional T cell responses, was IL-10 dependent, suggesting that there is a clear difference in mechanism between the Treg-mediated inhibition of these cell types. Our data highlight a physiologically relevant interaction between human iNKT and Tregs upon pathogen-derived glycolipid recognition that has a significant impact on the design of iNKT cell-based therapeutics.

  9. Polymer sorbent with the properties of an artificial cholesterol receptor

    Science.gov (United States)

    Polyakova, I. V.; Ezhova, N. M.; Osipenko, A. A.; Pisarev, O. A.

    2015-02-01

    A cholesterol-imprinted polymer sorbent and the corresponding reticular control copolymer were synthesized from hydroxyethyl methacrylate and ethyleneglycol dimethacrylate. The sorption isotherms of cholesterol were analyzed using the generalized Langmuir and Freundlich equations. In the case of the imprinted reticular polymer, cholesterol sorption occurred on the energetically homogeneous binding centers, forming one monolayer, while the nonspecific sorption of cholesterol on the control copolymer occurred with energetically nonhomogeneous binding of the sorbate and depended on the physicochemical conditions of sorption.

  10. Immobilization of cholesterol esterase and cholesterol oxidase onto sol-gel films for application to cholesterol biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Suman [Central Mechanical Engineering Research Institute, G. Avenue, Durgapur 713209, West Bengal (India); Singhal, Rahul [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Malhotra, B.D. [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India)]. E-mail: bansi.malhotra@gmail.com

    2007-01-23

    Cholesterol oxidase (ChOx) and cholesterol esterase (ChEt) have been covalently immobilized onto tetraethylorthosilicate (TEOS) sol-gel films. The tetraethylorthosilicate sol-gel/ChEt/ChOx enzyme films thus prepared have been characterized using scanning electron microscopic (SEM), UV-vis spectroscopic, Fourier-transform-infrared (FTIR) spectroscopic and amperometric techniques, respectively. The results of photometric measurements carried out on tetraethylorthosilicate sol-gel/ChEt/ChOx reveal thermal stability up to 55 deg. C, response time as 180 s, linearity up to 780 mg dL{sup -1} (12 mM), shelf life of 1 month, detection limit of 12 mg dL{sup -1} and sensitivity as 5.4 x 10{sup -5} Abs. mg{sup -1} dL{sup -1}.

  11. Moderate alcohol consumption increases cholesterol efflux mediated by ABCA1

    NARCIS (Netherlands)

    Beulens, J.W.J.; Sierksma, A.; Tol, van A.; Fournier, C.

    2004-01-01

    Moderate alcohol consumption increases HDL cholesterol, which is involved in reverse cholesterol transport (RCT). The aim of this study was to investigate the effect of moderate alcohol consumption on cholesterol efflux, using J774 mouse macrophages and Fu5AH cells, and on other parameters in the RC

  12. Emerging roles of the intestine in control of cholesterol metabolism

    NARCIS (Netherlands)

    Kruit, Janine K.; Groen, Albert K.; van Berkel, Theo J.; Kuipers, Folkert

    2006-01-01

    The liver is considered the major "control center" for maintenance of whole body cholesterol homeostasis. This organ is the main site for de novo cholesterol synthesis, clears cholesterol-containing chylomicron remnants and low density lipoprotein particles from plasma and is the major contributor t

  13. Understanding Lipoproteins as Transporters of Cholesterol and Other Lipids

    Science.gov (United States)

    Biggerstaff, Kyle D.; Wooten, Joshua S.

    2004-01-01

    A clear picture of lipoprotein metabolism is essential for understanding the pathophysiology of atherosclerosis. Many students are taught that low-density lipoprotein-cholesterol is "bad" and high-density lipoprotein-cholesterol is "good." This misconception leads to students thinking that lipoproteins are types of cholesterol rather than…

  14. Cholesterol Assimilation by Lactobacillus Probiotic Bacteria: An In Vitro Investigation

    OpenAIRE

    Catherine Tomaro-Duchesneau; Mitchell L. Jones; Divya Shah; Poonam Jain; Shyamali Saha; Satya Prakash

    2014-01-01

    Excess cholesterol is associated with cardiovascular diseases (CVD), an important cause of mortality worldwide. Current CVD therapeutic measures, lifestyle and dietary interventions, and pharmaceutical agents for regulating cholesterol levels are inadequate. Probiotic bacteria have demonstrated potential to lower cholesterol levels by different mechanisms, including bile salt hydrolase activity, production of compounds that inhibit enzymes such as 3-hydroxy-3-methylglutaryl coenzyme A, and ch...

  15. Hypercholesterolemia: The Role of Schools in Cholesterol Screening.

    Science.gov (United States)

    Price, James H.; Casler, Suzanne M.

    1997-01-01

    Examines the prevalence of cardiovascular disease risk factors among children and adolescents, the pros and cons of cholesterol screening among youth, cholesterol assessments of at-risk youth, and the role of schools in cholesterol education and screening (focusing on comprehensive school health education and services). (SM)

  16. CHROMATOGRAPHIC METHODS IN THE ANALYSIS OF CHOLESTEROL AND RELATED LIPIDS

    NARCIS (Netherlands)

    HOVING, EB

    1995-01-01

    Methods using thin-layer chromatography, solid-phase extraction, gas chromatography, high-performance liquid chromatography and supercritical fluid chromatography are described for the analysis of single cholesterol, esterified and sulfated cholesterol, and for cholesterol in the context of other li

  17. HDL Cholesterol and Risk of Type 2 Diabetes

    DEFF Research Database (Denmark)

    Haase, Christiane L; Tybjærg-Hansen, Anne; Nordestgaard, Børge G;

    2015-01-01

    Observationally, low levels of HDL cholesterol are consistently associated with increased risk of type 2 diabetes. Therefore, plasma HDL cholesterol increasing has been suggested as a novel therapeutic option to reduce the risk of type 2 diabetes. Whether levels of HDL cholesterol are causally as...

  18. Carbon Inverse Opal Rods for Nonenzymatic Cholesterol Detection.

    Science.gov (United States)

    Zhong, Qifeng; Xie, Zhuoying; Ding, Haibo; Zhu, Cun; Yang, Zixue; Gu, Zhongze

    2015-11-18

    Carbon inverse opal rods made from silica photonic crystal rods are used for nonenzymatic cholesterol sensing. The characteristic reflection peak originating from the physical periodic structure works as sensing signals for quantitatively estimating cholesterol concentrations. Carbon inverse opal rods work both in cholesterol standard solutions and human serum. They are suitable for practical use in clinical diagnose.

  19. Porcine artery elastin preparation reduces serum cholesterol level in rats

    OpenAIRE

    Liyanage, Ruvini; Nakamura, Yumi; Shimada, Ken-ichiro; SEKIKAWA, Mitsuo; Jayawardana, Barana Chaminda; HAN, Kyu-Ho; Tomoko, Okada; Ohba, Kiyoshi; Takahata, Yoshihisa; Morimatsu, Fumiki; FUKUSHIMA, Michihiro; 福島, 道広; 島田, 謙一郎; 関川, 三男; 韓, 圭鎬

    2009-01-01

    The effect of porcine artery elastin on serum cholesterol level was investigated in rats fed a cholesterol-free diet. Rats were fed for 4 weeks, with a diet (ED) containing 15% casein and 5% of porcine artery elastin in comparison with a diet (CD) containing 20% casein. The total serum and non-HDL-cholesterol concentrations were lower (P

  20. 25-Hydroxycholesterol Increases the Availability of Cholesterol in Phospholipid Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Brett N.; Schlesinger, Paul H.; Ory, Daniel S.; Baker, Nathan A.

    2011-02-01

    Side-chain oxysterols are enzymatically generated oxidation products of cholesterol that serve a central role in mediating cholesterol homeostasis. Recent work has shown that side-chain oxysterols, such as 25-hydroxycholesterol (25-HC), alter membrane structure in very different ways from cholesterol, suggesting a possible mechanism for how these oxysterols regulate cholesterol homeostasis. Here we extend our previous work, using molecular dynamics simulations of 25-HC and cholesterol mixtures in 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) bilayers to examine interactions between 25-HC and cholesterol in the same bilayer. When added to cholesterol-containing membranes, 25-HC causes larger changes in membrane structure than when added to cholesterol-free membranes, demonstrating interactions between the two sterols. We also find that the presence of 25-HC changes the position, orientation, and solvent accessibility of cholesterol, shifting it into the water interface and therefore its availability to external acceptors. This is consistent with experimental results showing that oxysterols can trigger cholesterol trafficking from the plasma membrane to the endoplasmic reticulum. These interactions provide a potential mechanism for 25-HC-mediated regulation of cholesterol trafficking and homeostasis through direct modulation of cholesterol availability.

  1. On the puzzling distribution of cholesterol in the plasma membrane.

    Science.gov (United States)

    Giang, H; Schick, M

    2016-09-01

    The distribution of cholesterol between the two leaves of the plasma membrane in mammalian cells presents a conundrum; given cholesterol's known affinity for sphingomyelin, which resides predominantly in the exoplasmic leaf, why is it that experiment finds a majority of the cholesterol in the cytoplasmic leaf? This article reviews a recently proposed solution to this puzzle. PMID:26724709

  2. Alcohol consumption stimulates early steps in reverse cholesterol transport

    NARCIS (Netherlands)

    Gaag, M.S. van der; Tol, A. van; Vermunt, S.H.F.; Scheek, L.M.; Schaafsma, G.; Hendriks, H.F.J.

    2001-01-01

    Alcohol consumption is associated with increased HDL cholesterol levels, which may indicate stimulated reverse cholesterol transport. The mechanism is, however, not known. The aim of this study was to evaluate the effects of alcohol consumption on the first two steps of the reverse cholesterol pathw

  3. Effects of Cholesterol-altering Pharmaceuticals on Cholesterol Metabolism, Steroidogenesis, and Gene Expression in the Fathead Minnow (Pimephales promelas)

    Science.gov (United States)

    Pharmaceuticals that target cholesterol biosynthesis and uptake are among the most widely prescribed drugs and have been detected in the aquatic environment. Fibrates are a class of pharmaceuticals that indirectly modulate cholesterol biosynthesis through effects on peroxisome pr...

  4. Constrained Allocation Flux Balance Analysis

    CERN Document Server

    Mori, Matteo; Martin, Olivier C; De Martino, Andrea; Marinari, Enzo

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an "ensemble averaging" procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferr...

  5. Formal language constrained path problems

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, C.; Jacob, R.; Marathe, M.

    1997-07-08

    In many path finding problems arising in practice, certain patterns of edge/vertex labels in the labeled graph being traversed are allowed/preferred, while others are disallowed. Motivated by such applications as intermodal transportation planning, the authors investigate the complexity of finding feasible paths in a labeled network, where the mode choice for each traveler is specified by a formal language. The main contributions of this paper include the following: (1) the authors show that the problem of finding a shortest path between a source and destination for a traveler whose mode choice is specified as a context free language is solvable efficiently in polynomial time, when the mode choice is specified as a regular language they provide algorithms with improved space and time bounds; (2) in contrast, they show that the problem of finding simple paths between a source and a given destination is NP-hard, even when restricted to very simple regular expressions and/or very simple graphs; (3) for the class of treewidth bounded graphs, they show that (i) the problem of finding a regular language constrained simple path between source and a destination is solvable in polynomial time and (ii) the extension to finding context free language constrained simple paths is NP-complete. Several extensions of these results are presented in the context of finding shortest paths with additional constraints. These results significantly extend the results in [MW95]. As a corollary of the results, they obtain a polynomial time algorithm for the BEST k-SIMILAR PATH problem studied in [SJB97]. The previous best algorithm was given by [SJB97] and takes exponential time in the worst case.

  6. Effect of testosterone deficiency on cholesterol metabolism in pigs fed a high-fat and high-cholesterol diet

    OpenAIRE

    Cai, Zhaowei; Xi, Haitao; Pan, Yongming; Jiang, Xiaoling; Chen, Liang; Cai, Yueqin; Zhu, Keyan; Chen, Cheng; XU, XIAOPING; Chen, Minli

    2015-01-01

    Background Testosterone deficiency is associated with increased serum cholesterol levels. However, how testosterone deficiency precisely affects cholesterol metabolism remains unclear. Therefore, in the current study, we examined the effect of testosterone deficiency on cholesterol metabolism and liver gene expression in pigs fed a high-fat and high-cholesterol (HFC) diet. Methods Sexually mature male miniature pigs (6–7 months old) were randomly divided into 3 groups as follows: intact male ...

  7. Accessibility of Cholesterol in Endoplasmic Reticulum Membranes and Activation of SREBP-2 Switch Abruptly at a Common Cholesterol Threshold

    OpenAIRE

    Sokolov, Anna; Radhakrishnan, Arun

    2010-01-01

    Recent studies have shown that cooperative interactions in endoplasmic reticulum (ER) membranes between Scap, cholesterol, and Insig result in switch-like control over activation of SREBP-2 transcription factors. This allows cells to rapidly adjust rates of cholesterol synthesis and uptake in response to even slight deviations from physiological set-point levels, thereby ensuring cholesterol homeostasis. In the present study we directly probe for the accessibility of cholesterol in purified E...

  8. Understanding Cholesterol and Heart Health | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... cholesterol throughout the body: Low-density lipoproteins (LDL): LDL cholesterol sometimes is called "bad" cholesterol. A high LDL ... or even death. The higher the level of LDL cholesterol in your blood, the GREATER your chance is ...

  9. Effects of saturated and unsaturated fats given with and without dietary cholesterol on hepatic cholesterol synthesis and hepatic lipid metabolism.

    Science.gov (United States)

    Bochenek, W; Rodgers, J B

    1978-01-27

    Hepatic cholesterol synthesis was studied in rats after consuming diets of varying neutral lipid and cholesterol content. Cholesterol synthesis was evaluated by measuring 3-hydroxy-3-methylglutaryl-CoA reductase and by determining the rate of 3H-labeled sterol production from [3H]mevalonate. Results were correlated with sterol balance data and hepatic lipid content. Hepatic cholesterol synthesis was relatively great when cholesterol was excluded from the diet. The source of neutral dietary lipids, saturated vs. unsaturated, produced no change in hepatic sterol synthesis. Values for fecal sterol outputs and hepatic cholesterol levels were also similar in rats consuming either saturated or unsaturated fats. When 1% cholesterol was added to the diet, hepatic cholesterol synthesis was suppressed but the degree of suppression was greater in rats consuming unsaturated vs. saturated fats. This was associated with greater accumulation of cholesterol in livers from rats consuming unsaturates and a reduction in fecal neutral sterol output in this group as opposed to results from rats on saturated fats. Cholesterol consumption also altered the fatty acid composition of hepatic phospholipids producing decreases in the percentages of essential polyunsaturated fatty acids. It is concluded that dietary cholesterol alters cholesterol and fatty acid metabolism in the liver and that this effect is enhanced by dietary unsaturated fats.

  10. A cholesterol-free, high-fat diet suppresses gene expression of cholesterol transporters in murine small intestine

    NARCIS (Netherlands)

    Bosch, van den H.M.; Wit, de N.J.W.; Hooiveld, G.J.E.J.; Vermeulen, H.; Veen, van der J.N.; Houten, S.M.; Kuipers, F.; Müller, M.R.; Meer, van der R.

    2008-01-01

    Transporters present in the epithelium of the small intestine determine the efficiency by which dietary and biliary cholesterol are taken up into the body and thus control whole-body cholesterol balance. Niemann-Pick C1 Like Protein 1 (Npc1l1) transports cholesterol into the enterocyte, whereas ATP-

  11. Fibroblast cholesterol efflux to plasma from metabolic syndrome subjects is not defective despite low high-density lipoprotein cholesterol

    NARCIS (Netherlands)

    R.P.F. Dullaart (Robin); A. Groen (Albert); G.M. Dallinga-Thie (Geesje); R. de Vries (Rindert); W. Sluiter (Wim); A. van Tol (Arie)

    2008-01-01

    textabstractObjective: We tested whether in metabolic syndrome (MetS) subjects the ability of plasma to stimulate cellular cholesterol efflux, an early step in the anti-atherogenic reverse cholesterol transport pathway, is maintained despite low high-density lipoprotein (HDL) cholesterol. Design: In

  12. Isolation of basidiomycetous yeast Pseudozyma tsukubaensis and production of glycolipid biosurfactant, a diastereomer type of mannosylerythritol lipid-B.

    Science.gov (United States)

    Morita, Tomotake; Takashima, Masako; Fukuoka, Tokuma; Konishi, Masaaki; Imura, Tomohiro; Kitamoto, Dai

    2010-10-01

    The producers of glycolipid biosurfactant, mannosylerythritol lipid-B (MEL-B), were isolated from leaves of Perilla frutescens on Ibaraki in Japan. Four isolates, 1D9, 1D10, 1D11, and 1E5, were identified as basidiomycetous yeast Pseudozyma tsukubaensis by rDNA sequence and biochemical properties. The structure of MEL-B produced by these strains was analyzed by (1)H nuclear magnetic resonance and gas chromatography-mass spectrometry methods, and was determined to be the same as the diastereomer MEL-B produced by P. tsukubaensis NBRC 1940. Of these isolates, P. tsukubaensis 1E5 (JCM 16987) is capable of producing the largest amount of the diastereomer MEL-B from vegetable oils. In order to progress the diastereomer MEL-B production by strain 1E5, factors affecting the production, such as carbon and organic nutrient sources, were further examined. Olive oil and yeast extract were the best carbon and nutrient sources, respectively. Under the optimal conditions, a maximum yield, productivity, and yield coefficient of 73.1 g/L, 10.4 g L(-1) day(-1), and 43.5 g/g were achieved by feeding of olive oil in a 5-L jar-fermenter culture using strain 1E5. PMID:20652239

  13. A yeast glycolipid biosurfactant, mannosylerythritol lipid, shows high binding affinity towards lectins on a self-assembled monolayer system.

    Science.gov (United States)

    Konishi, Masaaki; Imura, Tomohiro; Fukuoka, Tokuma; Morita, Tomotake; Kitamoto, Dai

    2007-03-01

    Mannosylerythritol lipids (MEL), which are glycolipid biosurfactants secreted by the Pseudozyma yeasts, show not only excellent surface-active properties but also versatile biochemical actions including antitumor and cell-differentiation activities. In order to address the biochemical actions, interactions between MEL-A, the major component of MEL, and different lectins were investigated using the surface plasmon resonance spectroscopy. The monolayer of MEL-A showed high binding affinity to concanavalin A (ConA) and Maackia amurensis lectin-I (MAL-I). The observed affinity constants for ConA and MAL-I were estimated to be 9.48 +/- 1.31 x 10(6) and 3.13 +/- 0.274 x 10(6) M(-1), respectively; the value was comparable to that of Manalpha1-6(Manalpha1-3)Man, which is one of the most specific probe to ConA. Significantly, alpha-methyl-D-mannopyranoside (1 mM) exhibited no binding inhibition between MEL-A and ConA. MEL-A is thus likely to self-assemble to give a high affinity surface, where ConA binds to the hydrophilic headgroup in a different manner from that generally observed in lectin-saccharide interactions. The binding manner should be related with the biochemical actions of MEL toward mammalian cells via protein-carbohydrate interactions. PMID:17205206

  14. Novel Glycolipids Synthesized Using Plant Essential Oils and Their Application in Quorum Sensing Inhibition and as Antibiofilm Agents

    Directory of Open Access Journals (Sweden)

    Ruchira Mukherji

    2014-01-01

    Full Text Available Essential oils (EOs form an important part of traditional medicine so their anti-microbial and, in the recent past, antiquorum sensing activity has been well studied. However it is likely that due to their hydrophobic nature and reduced solubility in aqueous environments full potential of their activity cannot be realized. hence it is only rational to formulate a process to make these molecules more polar in nature. The present paper reports synthesis of sophorolipids using 12 different essential oils as substrates, thus providing surfactant-like properties to these EOs. The synthesis protocol makes the use of Candida bombicola ATCC 22214 as producer organism. The production process required 7 days of incubation at 28°C and 180 rpm. Preliminary characterization of the synthesized essential oil sophorolipids (EOSLs was performed using thin layer chromatography (TLC and Fourier transform infrared spectroscopy (FTIR. Additionally, essential oils that were incapable of mediating quorum sensing inhibition (QSI on their own became potent quorum sensing inhibitors upon conversion into their corresponding EOSLs. Antibiofilm potential of these EOSLs was also demonstrated using V. cholerae as test organism. Use of essential oils as substrates for glycolipid synthesis has not been attempted previously, and hence this is the first report.

  15. Novel glycolipids synthesized using plant essential oils and their application in quorum sensing inhibition and as antibiofilm agents.

    Science.gov (United States)

    Mukherji, Ruchira; Prabhune, Asmita

    2014-01-01

    Essential oils (EOs) form an important part of traditional medicine so their anti-microbial and, in the recent past, antiquorum sensing activity has been well studied. However it is likely that due to their hydrophobic nature and reduced solubility in aqueous environments full potential of their activity cannot be realized. hence it is only rational to formulate a process to make these molecules more polar in nature. The present paper reports synthesis of sophorolipids using 12 different essential oils as substrates, thus providing surfactant-like properties to these EOs. The synthesis protocol makes the use of Candida bombicola ATCC 22214 as producer organism. The production process required 7 days of incubation at 28°C and 180 rpm. Preliminary characterization of the synthesized essential oil sophorolipids (EOSLs) was performed using thin layer chromatography (TLC) and Fourier transform infrared spectroscopy (FTIR). Additionally, essential oils that were incapable of mediating quorum sensing inhibition (QSI) on their own became potent quorum sensing inhibitors upon conversion into their corresponding EOSLs. Antibiofilm potential of these EOSLs was also demonstrated using V. cholerae as test organism. Use of essential oils as substrates for glycolipid synthesis has not been attempted previously, and hence this is the first report.

  16. Playing hide-and-seek with host macrophages through the use of mycobacterial cell envelope phthiocerol dimycocerosates and phenolic glycolipids

    Directory of Open Access Journals (Sweden)

    Ainhoa eARBUES

    2014-12-01

    Full Text Available Mycobacterial pathogens, including Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB, have evolved a remarkable ability to evade the immune system in order to survive and to colonize the host. Among the most important evasion strategies is the capacity of these bacilli to parasitize host macrophages, since these are major effector cells against intracellular pathogens that can be used as long-term cellular reservoirs. Mycobacterial pathogens employ an array of virulence factors that manipulate macrophage function to survive and establish infection. Until recently, however, the role of mycobacterial cell envelope lipids as virulence factors in macrophage subversion has remained elusive. Here, we will address exclusively the proposed role for phthiocerol dimycocerosates (DIM in the modulation of the resident macrophage response and that of phenolic glycolipids (PGL in the regulation of the recruitment and phenotype of incoming macrophage precursors to the site of infection. We will provide a unique perspective of potential additional functions for these lipids, and highlight obstacles and opportunities to further understand their role in the pathogenesis of TB and other mycobacterial diseases.

  17. Novel glycolipids synthesized using plant essential oils and their application in quorum sensing inhibition and as antibiofilm agents.

    Science.gov (United States)

    Mukherji, Ruchira; Prabhune, Asmita

    2014-01-01

    Essential oils (EOs) form an important part of traditional medicine so their anti-microbial and, in the recent past, antiquorum sensing activity has been well studied. However it is likely that due to their hydrophobic nature and reduced solubility in aqueous environments full potential of their activity cannot be realized. hence it is only rational to formulate a process to make these molecules more polar in nature. The present paper reports synthesis of sophorolipids using 12 different essential oils as substrates, thus providing surfactant-like properties to these EOs. The synthesis protocol makes the use of Candida bombicola ATCC 22214 as producer organism. The production process required 7 days of incubation at 28°C and 180 rpm. Preliminary characterization of the synthesized essential oil sophorolipids (EOSLs) was performed using thin layer chromatography (TLC) and Fourier transform infrared spectroscopy (FTIR). Additionally, essential oils that were incapable of mediating quorum sensing inhibition (QSI) on their own became potent quorum sensing inhibitors upon conversion into their corresponding EOSLs. Antibiofilm potential of these EOSLs was also demonstrated using V. cholerae as test organism. Use of essential oils as substrates for glycolipid synthesis has not been attempted previously, and hence this is the first report. PMID:24558341

  18. Production and characterisation of glycolipid biosurfactant by Halomonas sp. MB-30 for potential application in enhanced oil recovery.

    Science.gov (United States)

    Dhasayan, Asha; Kiran, G Seghal; Selvin, Joseph

    2014-12-01

    Biosurfactant-producing Halomonas sp. MB-30 was isolated from a marine sponge Callyspongia diffusa, and its potency in crude oil recovery from sand pack column was investigated. The biosurfactant produced by the strain MB-30 reduced the surface tension to 30 mN m(-1) in both glucose and hydrocarbon-supplemented minimal media. The critical micelle concentration of biosurfactant obtained from glucose-based medium was at 0.25 mg ml(-1) at critical micelle dilution 1:10. The chemical structure of glycolipid biosurfactant was characterised by infrared spectroscopy and proton magnetic resonance spectroscopy. The emulsification activity of MB-30 biosurfactant was tested with different hydrocarbons, and 93.1 % emulsification activity was exhibited with crude oil followed by kerosene (86.6 %). The formed emulsion was stable for up to 1 month. To identify the effectiveness of biosurfactant for enhanced oil recovery in extreme environments, the interactive effect of pH, temperature and salinity on emulsion stability with crude oil and kerosene was evaluated. The stable emulsion was formed at and above pH 7, temperature >80 °C and NaCl concentration up to 10 % in response surface central composite orthogonal design model. The partially purified biosurfactant recovered 62 % of residual crude oil from sand pack column. Thus, the stable emulsifying biosurfactant produced by Halomonas sp. MB-30 could be used for in situ biosurfactant-mediated enhanced oil recovery process and hydrocarbon bioremediation in extreme environments. PMID:25326183

  19. Spatially-Resolved Analysis of Glycolipids and Metabolites in Living Synechococcus sp. PCC7002 Using Nanospray Desorption Electrospray Ionization

    Energy Technology Data Exchange (ETDEWEB)

    Lanekoff, Ingela T.; Geydebrekht, Oleg V.; Pinchuk, Grigoriy E.; Konopka, Allan; Laskin, Julia

    2013-04-07

    Microorganisms release a diversity of organic compounds that couple interspecies metabolism, enable communication, or provide benefits to other microbes. Increased knowledge of microbial metabolite production will contribute to understanding of the dynamic microbial world and can potentially lead to new developments in drug discovery, biofuel production, and clinical research. Nanospray desorption electrospray ionization (nano-DESI) is an ambient ionization technique that enables detailed chemical characterization of molecules from a specific location on a surface without special sample pretreatment. Due to its ambient nature, living bacterial colonies growing on agar plates can be rapidly and non-destructively analyzed. We performed spatially resolved nano-DESI analysis of living Synechococcus sp. PCC 7002 colonies on agar plates. We use high resolution mass spectrometry and MS/MS analysis of the living Synechococcus sp. PCC 7002 colonies to detect metabolites and lipids, and confirm their identities. We found that despite the high salt content of the agar (osmolarity ca. 700 mM), nano-DESI analysis enables detailed characterization of metabolites produced by the colony. Using this technique, we identified several glycolipids found on the living colonies and examined the effect of the age of the colony on the chemical gradient of glucosylglycerol secreted onto agar.

  20. Cholesterol efflux capacity: An introduction for clinicians.

    Science.gov (United States)

    Anastasius, Malcolm; Kockx, Maaike; Jessup, Wendy; Sullivan, David; Rye, Kerry-Anne; Kritharides, Leonard

    2016-10-01

    Epidemiologic studies have shown an inverse correlation between high-density lipoprotein (HDL) cholesterol (HDL-C) levels and cardiovascular disease outcomes. However, the hypothesis of a causal relationship between HDL-C and cardiovascular disease has been challenged by genetic and clinical studies. Serum cholesterol efflux capacity (CEC) is an important measure of HDL function in humans. Recent large clinical studies have shown a correlation between in vitro CEC and cardiovascular disease prevalence and incidence, which appears to be independent of HDL-C concentration. The present review summarizes recent large clinical studies and introduces important methodological considerations. Further studies are required to standardize and establish the reproducibility of this measure of HDL function and clarify whether modulating CEC will emerge as a useful therapeutic target. PMID:27659883

  1. Cholesterol in serum lipoprotein fractions after spaceflight

    Science.gov (United States)

    Leach, Carolyn S.; Johnson, Philip C., Jr.; Krauhs, Jane M.; Cintron, Nitza M.

    1988-01-01

    Results are reported from blood-lipid measurements obtained from 125 Space Shuttle crew members before and after space flight. The data are presented in tables and discussed in detail. The main differences noted between preflight and postflight values are a 12.8-percent decrease in high-density lipoproteins on postflight day 1 and significant decreases in total cholesterol and both high- and low-density lipoproteins later in the 23-day postflight period.

  2. Structure of cholesterol/ceramide monolayer mixtures

    DEFF Research Database (Denmark)

    Scheffer, L.; Solomonov, I.; Weygand, M.J.;

    2005-01-01

    The structure of monolayers of cholesterol/ ceramide mixtures was investigated using grazing incidence x-ray diffraction, immunofluorescence, and atomic force microscopy techniques. Grazing incidence x-ray diffraction measurements showed the existence of a crystalline mixed phase of the two....... As ceramide incorporates the lipid backbone common to all sphingolipids, this arrangement may be relevant to the understanding of the molecular organization of lipid rafts....

  3. Potent and selective mediators of cholesterol efflux

    Energy Technology Data Exchange (ETDEWEB)

    Bielicki, John K; Johansson, Jan

    2015-03-24

    The present invention provides a family of non-naturally occurring polypeptides having cholesterol efflux activity that parallels that of full-length apolipoproteins (e.g., Apo AI and Apo E), and having high selectivity for ABAC1 that parallels that of full-length apolipoproteins. The invention also provides compositions comprising such polypeptides, methods of identifying, screening and synthesizing such polypeptides, and methods of treating, preventing or diagnosing diseases and disorders associated with dyslipidemia, hypercholesterolemia and inflammation.

  4. Common Force Field Thermodynamics of Cholesterol

    OpenAIRE

    Francesco Giangreco; Eiji Yamamoto; Yoshinori Hirano; Milan Hodoscek; Volker Knecht; Matteo di Giosia; Matteo Calvaresi; Francesco Zerbetto; Kenji Yasuoka; Tetsu Narumi; Masato Yasui; Siegfried Höfinger

    2013-01-01

    Four different force fields are examined for dynamic characteristics using cholesterol as a case study. The extent to which various types of internal degrees of freedom become thermodynamically relevant is evaluated by means of principal component analysis. More complex degrees of freedom (angle bending, dihedral rotations) show a trend towards force field independence. Moreover, charge assignments for membrane-embedded compounds are revealed to be critical with s...

  5. [HDL cholesterol as a sensitive diagnostic parameter in malaria].

    Science.gov (United States)

    Kittl, E M; Diridl, G; Lenhart, V; Neuwald, C; Tomasits, J; Pichler, H; Bauer, K

    1992-01-01

    In patients with malaria the lipid parameters triglycerides, cholesterol, and HDL-cholesterol were determined routinely. At the time of admission hypertriglyceridemia, hypocholesterolemia, and an extreme decrease in HDL-cholesterol were found. This dyslipoproteinemia was present in cases of falciparum malaria, as well as in cases of benign tertian malaria. The extent of HDL-cholesterol decrease showed no correlation to the severity of the clinical course of disease. HDL-cholesterol has proven to be an independent diagnostic laboratory finding in cases of suspected malarial infection. This parameter displays high diagnostic sensitivity, but no specificity for malaria. PMID:1546481

  6. Constraining Modified Gravity Theories With Cosmology

    OpenAIRE

    Martinelli, Matteo

    2012-01-01

    We study and constrain the Hu and Sawicki f(R) model using CMB and weak lensing forecasted data. We also use the same data to constrain extended theories of gravity and the subclass of f(R) theories using a general parameterization describing departures from General Relativity. Moreover we study and constrain also a Dark Coupling model where Dark Energy and Dark Matter are coupled toghether.

  7. Astragalus polysaccharides lowers plasma cholesterol through mechanisms distinct from statins.

    Directory of Open Access Journals (Sweden)

    Yunjiu Cheng

    Full Text Available To determine the efficacy and underlying mechanism of Astragalus polysaccharides (APS on plasma lipids in hypercholesterolemia hamsters. The effect of APS (0.25 g/kg/d on plasma and liver lipids, fecal bile acids and neutral sterol, cholesterol absorption and synthesis, HMG-CoA reductase activity, and gene and protein expressions in the liver and small intestine was investigated in twenty-four hypercholesterolemia hamsters. Treatment periods lasted for three months. APS significantly lowered plasma total cholesterol by 45.8%, triglycerides by 30%, and low-density lipoprotein-cholesterol by 47.4%, comparable to simvastatin. Further examinations revealed that APS reduced total cholesterol and triglycerides in the liver, increased fecal bile acid and neutral sterol excretion, inhibited cholesterol absorption, and by contrast, increased hepatic cholesterol synthesis and HMG-CoA reductase activity. Plasma total cholesterol or low-density lipoprotein-cholesterol levels were significantly correlated with cholesterol absorption rates. APS up-regulated cholesterol-7α-hydroxylase and LDL-receptor gene expressions. These new findings identify APS as a potential natural cholesterol lowering agent, working through mechanisms distinct from statins.

  8. Preterm delivery and low maternal serum cholesterol level: Any correlation?

    Directory of Open Access Journals (Sweden)

    Ayodeji A Oluwole

    2014-01-01

    Full Text Available Background: The study assessed whether low maternal serum cholesterol during early pregnancy is associated with preterm delivery. Patients and Methods: It was a prospective observational cohort study involving pregnant women at gestational age of 14-20 weeks over a period of 12 months. Blood samples were obtained to measure total serum cholesterol concentrations and the sera were then analysed enzymatically by the cholesterol oxidase: p-aminophenazone (CHOD PAP method. Results: The study showed an incidence of 5.0% for preterm delivery in the low risk study patients. Preterm birth was 4.83-times more common with low total maternal cholesterol than with midrange total cholesterol (11.8% versus 2.2%, P = 0.024. Conclusion: Low maternal serum cholesterol (hypocholesterolaemia is associated with preterm delivery. Optimal maternal serum cholesterol during pregnancy may have merit, therefore pregnant women should be encouraged to follow a healthy, balanced diet.

  9. Preparation of cholesterol oxidase nanoparticles and their application in amperometric determination of cholesterol

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, Sheetal; Rawal, Rachna; Sonia; Ramrati; Pundir, C. S., E-mail: pundircs@rediffmail.com [M. D. University, Department of Biochemistry (India)

    2013-09-15

    The nanoparticle (NP) aggregates of commercial cholesterol oxidase (ChOx) were prepared by desolvation method. The formation and characterization of ChOxNP aggregates were studied by transmission electron microscopy and scanning electron microscopy. NP aggregates were more stable, active and had a higher shelf life than that of free enzyme. An amperometric cholesterol biosensor was constructed by immobilizing ChOxNPs onto Au electrode. The biosensor showed optimum response within 8 s at pH 6.0 and 35 Degree-Sign C, when polarized at +0.27 V versus Ag/AgCl. The biosensor possesses high sensitivity and measures cholesterol concentrations as low as 1.56 mg/dl. The working linear range was 12.5-700 mg/dl for cholesterol. The biosensor was evaluated and employed for measurement of total cholesterol in human serum. The enzyme electrode lost 50 % of its initial activity during its regular use for 180 times over a period of 90 days when stored in 0.1 M sodium phosphate buffer, pH 7.0 at 4 Degree-Sign C.

  10. Constraining the Europa Neutral Torus

    Science.gov (United States)

    Smith, Howard T.; Mitchell, Donald; mauk, Barry; Johnson, Robert E.; clark, george

    2016-10-01

    "Neutral tori" consist of neutral particles that usually co-orbit along with their source forming a toroidal (or partial toroidal) feature around the planet. The distribution and composition of these features can often provide important, if not unique, insight into magnetospheric particles sources, mechanisms and dynamics. However, these features can often be difficult to directly detect. One innovative method for detecting neutral tori is by observing Energetic Neutral Atoms (ENAs) that are generally considered produced as a result of charge exchange interactions between charged and neutral particles.Mauk et al. (2003) reported the detection of a Europa neutral particle torus using ENA observations. The presence of a Europa torus has extremely large implications for upcoming missions to Jupiter as well as understanding possible activity at this moon and providing critical insight into what lies beneath the surface of this icy ocean world. However, ENAs can also be produced as a result of charge exchange interactions between two ionized particles and in that case cannot be used to infer the presence of neutral particle population. Thus, a detailed examination of all possible source interactions must be considered before one can confirm that likely original source population of these ENA images is actually a Europa neutral particle torus. For this talk, we examine the viability that the Mauk et al. (2003) observations were actually generated from a neutral torus emanating from Europa as opposed to charge particle interactions with plasma originating from Io. These results help constrain such a torus as well as Europa source processes.

  11. Gyrification from constrained cortical expansion

    CERN Document Server

    Tallinen, Tuomas; Biggins, John S; Mahadevan, L

    2015-01-01

    The exterior of the mammalian brain - the cerebral cortex - has a conserved layered structure whose thickness varies little across species. However, selection pressures over evolutionary time scales have led to cortices that have a large surface area to volume ratio in some organisms, with the result that the brain is strongly convoluted into sulci and gyri. Here we show that the gyrification can arise as a nonlinear consequence of a simple mechanical instability driven by tangential expansion of the gray matter constrained by the white matter. A physical mimic of the process using a layered swelling gel captures the essence of the mechanism, and numerical simulations of the brain treated as a soft solid lead to the formation of cusped sulci and smooth gyri similar to those in the brain. The resulting gyrification patterns are a function of relative cortical expansion and relative thickness (compared with brain size), and are consistent with observations of a wide range of brains, ranging from smooth to highl...

  12. Constrained Allocation Flux Balance Analysis

    Science.gov (United States)

    Mori, Matteo; Hwa, Terence; Martin, Olivier C.

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an “ensemble averaging” procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

  13. When cholesterol is not cholesterol: a note on the enzymatic determination of its concentration in model systems containing vegetable extracts

    Directory of Open Access Journals (Sweden)

    Pamplona Reinald

    2010-06-01

    Full Text Available Abstract Background Experimental evidences demonstrate that vegetable derived extracts inhibit cholesterol absorption in the gastrointestinal tract. To further explore the mechanisms behind, we modeled duodenal contents with several vegetable extracts. Results By employing a widely used cholesterol quantification method based on a cholesterol oxidase-peroxidase coupled reaction we analyzed the effects on cholesterol partition. Evidenced interferences were analyzed by studying specific and unspecific inhibitors of cholesterol oxidase-peroxidase coupled reaction. Cholesterol was also quantified by LC/MS. We found a significant interference of diverse (cocoa and tea-derived extracts over this method. The interference was strongly dependent on model matrix: while as in phosphate buffered saline, the development of unspecific fluorescence was inhibitable by catalase (but not by heat denaturation, suggesting vegetable extract derived H2O2 production, in bile-containing model systems, this interference also comprised cholesterol-oxidase inhibition. Several strategies, such as cholesterol standard addition and use of suitable blanks containing vegetable extracts were tested. When those failed, the use of a mass-spectrometry based chromatographic assay allowed quantification of cholesterol in models of duodenal contents in the presence of vegetable extracts. Conclusions We propose that the use of cholesterol-oxidase and/or peroxidase based systems for cholesterol analyses in foodstuffs should be accurately monitored, as important interferences in all the components of the enzymatic chain were evident. The use of adequate controls, standard addition and finally, chromatographic analyses solve these issues.

  14. Determination of optimal gains for constrained controllers

    Energy Technology Data Exchange (ETDEWEB)

    Kwan, C.M.; Mestha, L.K.

    1993-08-01

    In this report, we consider the determination of optimal gains, with respect to a certain performance index, for state feedback controllers where some elements in the gain matrix are constrained to be zero. Two iterative schemes for systematically finding the constrained gain matrix are presented. An example is included to demonstrate the procedures.

  15. Control of Angiogenesis by AIBP-mediated Cholesterol Efflux

    Science.gov (United States)

    Fang, Longhou; Choi, Soo-Ho; Baek, Ji Sun; Liu, Chao; Almazan, Felicidad; Ulrich, Florian; Wiesner, Philipp; Taleb, Adam; Deer, Elena; Pattison, Jennifer; Torres-Vázquez, Jesús; Li, Andrew C.; Miller, Yury I.

    2013-01-01

    Cholesterol is a structural component of the cell, indispensable for normal cellular function, but its excess often leads to abnormal proliferation, migration, inflammatory responses and/or cell death. To prevent cholesterol overload, ATP-binding cassette (ABC) transporters mediate cholesterol efflux from the cells to apolipoprotein A-I (ApoA-I) and to the ApoA-I-containing high-density lipoprotein (HDL)1-3. Maintaining efficient cholesterol efflux is essential for normal cellular function4-6. However, the role of cholesterol efflux in angiogenesis and the identity of its local regulators are poorly understood. Here we show that ApoA-I binding protein (AIBP) accelerates cholesterol efflux from endothelial cells (EC) to HDL and thereby regulates angiogenesis. AIBP/HDL-mediated cholesterol depletion reduces lipid rafts, interferes with VEGFR2 dimerization and signaling, and inhibits VEGF-induced angiogenesis in vitro and mouse aortic neovascularization ex vivo. Remarkably, Aibp regulates the membrane lipid order in embryonic zebrafish vasculature and functions as a non-cell autonomous regulator of zebrafish angiogenesis. Aibp knockdown results in dysregulated sprouting/branching angiogenesis, while forced Aibp expression inhibits angiogenesis. Dysregulated angiogenesis is phenocopied in Abca1/Abcg1-deficient embryos, and cholesterol levels are increased in Aibp-deficient and Abca1/Abcg1-deficient embryos. Our findings demonstrate that secreted AIBP positively regulates cholesterol efflux from EC and that effective cholesterol efflux is critical for proper angiogenesis. PMID:23719382

  16. Cholesterol: Its Regulation and Role in Central Nervous System Disorders

    Directory of Open Access Journals (Sweden)

    Matthias Orth

    2012-01-01

    Full Text Available Cholesterol is a major constituent of the human brain, and the brain is the most cholesterol-rich organ. Numerous lipoprotein receptors and apolipoproteins are expressed in the brain. Cholesterol is tightly regulated between the major brain cells and is essential for normal brain development. The metabolism of brain cholesterol differs markedly from that of other tissues. Brain cholesterol is primarily derived by de novo synthesis and the blood brain barrier prevents the uptake of lipoprotein cholesterol from the circulation. Defects in cholesterol metabolism lead to structural and functional central nervous system diseases such as Smith-Lemli-Opitz syndrome, Niemann-Pick type C disease, and Alzheimer’s disease. These diseases affect different metabolic pathways (cholesterol biosynthesis, lipid transport and lipoprotein assembly, apolipoproteins, lipoprotein receptors, and signaling molecules. We review the metabolic pathways of cholesterol in the CNS and its cell-specific and microdomain-specific interaction with other pathways such as the amyloid precursor protein and discuss potential treatment strategies as well as the effects of the widespread use of LDL cholesterol-lowering drugs on brain functions.

  17. Phytosterol ester constituents affect micellar cholesterol solubility in model bile.

    Science.gov (United States)

    Brown, Andrew W; Hang, Jiliang; Dussault, Patrick H; Carr, Timothy P

    2010-09-01

    Plant sterols and stanols (phytosterols) and their esters are nutraceuticals that lower LDL cholesterol, but the mechanisms of action are not fully understood. We hypothesized that intact esters and simulated hydrolysis products of esters (phytosterols and fatty acids in equal ratios) would differentially affect the solubility of cholesterol in model bile mixed micelles in vitro. Sodium salts of glycine- and taurine-conjugated bile acids were sonicated with phosphatidylcholine and either sterol esters or combinations of sterols and fatty acids to determine the amount of cholesterol solubilized into micelles. Intact sterol esters did not solubilize into micelles, nor did they alter cholesterol solubility. However, free sterols and fatty acids altered cholesterol solubility independently (no interaction effect). Equal contents of cholesterol and either campesterol, stigmasterol, sitosterol, or stigmastanol (sitostanol) decreased cholesterol solubility in micelles by approximately 50% compared to no phytosterol present, with stigmasterol performing slightly better than sitosterol. Phytosterols competed with cholesterol in a dose-dependent manner, demonstrating a 1:1 M substitution of phytosterol for cholesterol in micelle preparations. Unsaturated fatty acids increased the micelle solubility of sterols as compared with saturated or no fatty acids. No differences were detected in the size of the model micelles. Together, these data indicate that stigmasterol combined with saturated fatty acids may be more effective at lowering cholesterol micelle solubility in vivo.

  18. Kinetic studies on the interactions between glycolipid biosurfactant assembled monolayers and various classes of immunoglobulins using surface plasmon resonance.

    Science.gov (United States)

    Ito, Seya; Imura, Tomohiro; Fukuoka, Tokuma; Morita, Tomotake; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2007-08-01

    Kinetic studies on the interactions between self-assembled monolayers of mannosylerythritol lipids (MELs), which are glycolipid biosurfactants abundantly produced by microorganisms, and various classes of immunoglobulins including human IgG, IgA, and IgM were performed using surface plasmon resonance (SPR). The effect of the MEL structure on the binding behavior of HIgG was examined. Assembled monolayers of MEL-A having two acetyl groups on the headgroup gave a high affinity (K(d)=1.7x10(-6)M) toward HIgG, while those of MEL-B or MEL-C having only one acetyl group at C-6' or C-4' position gave little affinity. Our kinetic analysis revealed that the binding manner of HIgG, HIgA (K(d)=2.4x10(-7)M), and HIgM (K(d)=2.2x10(-7)M) to the assembled monolayers of MEL-A is not the monovalent mode but the bivalent mode, and both the first and second rate association constants (k(a1), k(a2)) increase with an increase in the number of antibody binding sites, while those for dissociation (k(d1), k(d2)) changed little. Moreover, we succeeded in directly observing great amounts of HIgG, HIgA, and HIgM bound to MEL-A monolayers using atomic force microscopy (AFM). Finally, we found that MEL-A assembled monolayer binds toward various IgG derived from mouse, pig, rabbit, horse, goat, rat, and bovine as well as human IgG (HIgG), and the only exception was sheep IgG. These results clearly demonstrate that MEL-A assembled monolayers would be useful as noble affinity ligand system for various immunoglobulins. PMID:17428643

  19. Packing density of glycolipid biosurfactant monolayers give a significant effect on their binding affinity toward immunoglobulin G.

    Science.gov (United States)

    Imura, Tomohiro; Masuda, Yuma; Ito, Seya; Worakitkanchanakul, Wannasiri; Morita, Tomotake; Fukuoka, Tokuma; Sakai, Hideki; Abe, Masahiko; Kitamoto, Dai

    2008-01-01

    Mannosylerythritol lipid-A (MEL-A) is one of the most promising glycolipid biosurfactants, and abundantly produced by Pseudozyma yeasts. MEL-A gives not only excellent self-assembling properties but also a high binding affinity toward human immunoglobulin G (HIgG). In this study, three kinds of MEL-A were prepared from methyl myristate [MEL-A (m)], olive oil [MEL-A (o)], and soybean oil [MEL-A (s)], and the effect of interfacial properties of each MEL-A monolayer on the binding affinity toward HIgG was investigated using surface plasmon resonance (SPR) and the measurement of surface pressure (pi)-area (A) isotherms. Based on GC-MS analysis, the main fatty acids were C(8) and C(10) acids in all MEL-A, and the content of unsaturated fatty acids was 0% for MEL-A (m), 9.1% for MEL-A (o), 46.3% for MEL-A (s), respectively. Interestingly, the acid content significantly influenced on their binding affinity, and the monolayer of MEL-A (o) gave a higher binding affinity than that of MEL-A (m) and MEL-A (s). Moreover, the mixed MEL-A (o)/ MEL-A (s) monolayer prepared from 1/1 molar ratio, which comprised of 27.8% of unsaturated fatty acids, indicated the highest binding affinity. At the air/water interface, MEL-A (o) monolayer exhibited a phase transition at 13 degrees C from a liquid condensed monolayer to a liquid expanded monolayer, and the area per molecule significantly expanded above 13 degrees C, while the amount of HIgG bound to the liquid expanded monolayer was much higher than that bound to liquid condensed monolayer. The binding affinity of MEL-A toward HIgG is thus likely to closely relate to the monolayer packing density, and may be partly controlled by temperature. PMID:18622124

  20. Extracellular production of a glycolipid biosurfactant, mannosylerythritol lipid, by Candida sp. SY16 using fed-batch fermentation.

    Science.gov (United States)

    Kim, Hee-Sik; Jeon, Jong-Woon; Kim, Byung-Hyuk; Ahn, Chi-Yong; Oh, Hee-Mock; Yoon, Byung-Dae

    2006-04-01

    Candida sp. strain SY16 produces a glycolipid-type biosurfactant, mannosylerythritol lipid (MEL-SY16), which can reduce the surface tension of a culture broth from 72 to 30 dyne cm(-1) and highly emulsify hydrocarbons when cultured in soybean-oil-containing media. As such, laboratory-scale fermentation for MEL-SY16 production was performed using optimized conditions. In batch fermentation, MEL-SY16 was mainly produced during the stationary phase of growth, and the concentration of MEL-SY16 reached 37 g l(-1) after 200 h. The effect of pH control on the production of MEL-SY16 was also examined in batch fermentation. The highest production yield of MEL-SY16 was when the pH was controlled at 4.0, and the production was significantly improved compared to batch fermentation without pH control. In fed-batch fermentation, glucose and soybean oil (1:1, w/w) were used in combination as the initial carbon sources for cell growth, and soybean oil was used as the feeding carbon source during the MEL production phase. The feeding of soybean oil resulted in the disappearance of any foam and a sharp increase in the MEL production until 200 h, at which point the concentration of MEL-SY16 was 95 g l(-1). Among the investigated culture systems, the highest MEL-SY16 production and volumetric production rate were achieved with fed-batch fermentation. PMID:16133323

  1. Cholesterol Metabolism and Prostate Cancer Lethality.

    Science.gov (United States)

    Stopsack, Konrad H; Gerke, Travis A; Sinnott, Jennifer A; Penney, Kathryn L; Tyekucheva, Svitlana; Sesso, Howard D; Andersson, Swen-Olof; Andrén, Ove; Cerhan, James R; Giovannucci, Edward L; Mucci, Lorelei A; Rider, Jennifer R

    2016-08-15

    Cholesterol metabolism has been implicated in prostate cancer pathogenesis. Here, we assessed the association of intratumoral mRNA expression of cholesterol synthesis enzymes, transporters, and regulators in tumor specimen at diagnosis and lethal prostate cancer, defined as mortality or metastases from prostate cancer in contrast to nonlethal disease without evidence of metastases after at least 8 years of follow-up. We analyzed the prospective prostate cancer cohorts within the Health Professionals Follow-up Study (n = 249) and the Physicians' Health Study (n = 153) as well as expectantly managed patients in the Swedish Watchful Waiting Study (n = 338). The expression of squalene monooxygenase (SQLE) was associated with lethal cancer in all three cohorts. Men with high SQLE expression (>1 standard deviation above the mean) were 8.3 times (95% confidence interval, 3.5 to 19.7) more likely to have lethal cancer despite therapy compared with men with the mean level of SQLE expression. Absolute SQLE expression was associated with lethal cancer independently from Gleason grade and stage, as was a SQLE expression ratio in tumor versus surrounding benign prostate tissue. Higher SQLE expression was tightly associated with increased histologic markers of angiogenesis. Collectively, this study establishes the prognostic value of intratumoral cholesterol synthesis as measured via SQLE, its second rate-limiting enzyme. SQLE expression at cancer diagnosis is prognostic for lethal prostate cancer both after curative-intent prostatectomy and in a watchful waiting setting, possibly by facilitating micrometastatic disease. Cancer Res; 76(16); 4785-90. ©2016 AACR.

  2. Potassium-doped carbon nanotubes toward the direct electrochemistry of cholesterol oxidase and its application in highly sensitive cholesterol biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaorong [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Xu Jingjuan, E-mail: xujj@nju.edu.cn [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Chen Hongyuan [State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China)

    2011-10-30

    We demonstrate herein a newly developed serum total cholesterol biosensor by using the direct electron transfer of cholesterol oxidase (ChOx), which is based on the immobilization of cholesterol oxidase and cholesterol esterase (ChEt) on potassium-doped multi-walled carbon nanotubes (KMWNTs) modified electrodes. The KMWNTs accelerate the electron transfer from electrode surface to the immobilized ChOx, achieving the direct electrochemistry of ChOx and maintaining its bioactivity. As a new platform in cholesterol analysis, the resulting electrode (ChOx/KMWNTs/GCE) exhibits a sensitive response to free cholesterol, with a linear range of 0.050-16.0 {mu}mol L{sup -1} and a detection limit of 5.0 nmol L{sup -1} (S/N = 3). Coimmobilization of ChEt and ChOx (ChEt/ChOx/KMWNTs/GCE) allows the determination of both free cholesterol and esterified cholesterol. The resulting biosensor shows the same linear range of 0.050-16.0 {mu}mol L{sup -1} for free cholesterol and cholesteryl oleate, with the detection limit of 10.0 and 12.0 nmol L{sup -1} (S/N = 3), respectively. The concentrations of total (free and esterified) cholesterol in human serum samples, determined by using the techniques developed in the present study, are in good agreement with those determined by the well-established techniques using the spectrophotometry.

  3. Influence of infant and juvenile diets on serum cholesterol, lipoprotein cholesterol, and apolipoprotein concentrations in juvenile baboons (Papio sp.).

    Science.gov (United States)

    Mott, G E; McMahan, C A; Kelley, J L; Farley, C M; McGill, H C

    1982-11-01

    The long-term effects of infant diet (breast milk or formula containing 2, 30, or 60 mg/dl cholesterol) and subsequent dietary cholesterol (1 mg/kcal) and fat (saturated or unsaturated) on serum lipid and apolipoprotein concentrations were estimated using 82 juvenile baboons 4-6 years of age. A significant interaction of infant diet (breast vs formula) with type of fat (saturated vs unsaturated) at 4-6 years of age was observed on HDL cholesterol and apolipoprotein A-I (apoA-I) concentrations. That is, animals breast-fed as infants had higher HDL cholesterol and apoA-I concentrations when fed unsaturated fat from weaning to 4-6 years of age than those fed saturated fat (77 vs 68 mg/dl). In contrast, animals fed formulas in infancy followed by a diet containing unsaturated fat had lower HDL cholesterol and apoA-I concentrations at 4-6 years of age than did those fed saturated fat (67 vs 78 mg/dl). However, breast feeding or feeding formulas containing various levels of cholesterol for 3 months during infancy did not result in statistically significant differences in total serum cholesterol, VLDL + LDL cholesterol and apolipoprotein B (apoB) concentrations. Dietary cholesterol after infancy significantly increased serum total cholesterol, VLDL + LDL and HDL cholesterol, apoA-I and apoB concentrations. All of these response variables also were higher in animals fed saturated fat compared to those fed unsaturated fat on the same level of cholesterol. At 4-6 years of age, regardless of diet, females had significantly higher serum VLDL + LDL cholesterol (57 vs 43 mg/dl) and apoB concentrations (39 vs 30 mg/dl) than did males.

  4. Discovery of Pseudozyma rugulosa NBRC 10877 as a novel producer of the glycolipid biosurfactants, mannosylerythritol lipids, based on rDNA sequence.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2006-11-01

    The search for a novel producer of glycolipid biosurfactants, mannosylerythritol lipids (MEL) was undertaken based on the analysis of ribosomal DNA sequences on the yeast strains of the genus Pseudozyma. Pseudozyma rugulosa NBRC 10877 was found to produce a large amount of glycolipids from soybean oil. Fluorescence microscopic observation also demonstrated that the strain significantly accumulates polar lipids in the cells. The structure of the glycolipids produced by the strain was analyzed by (1)H and (13)C nuclear magnetic resonance and gas chromatography-mass spectrometry methods, and was determined to be the same as MEL produced by Pseudozyma antarctica, a well-known MEL producer. The major fatty acids of the present MEL consisted of C8 and C10 acids. Based on high performance liquid chromatography, the composition of the produced MEL was as follows: MEL-A (68%), MEL-B (12%), and MEL-C (20%). To enhance the production of MEL by the novel strain, factors affecting the production, such as carbon and nitrogen sources, were further examined. Soybean oil and sodium nitrate were the best carbon and nitrogen sources, respectively. The supplementation of a MEL precursor, such as erythritol, drastically enhanced the production yield from soybean oil at a rate of 70 to 90%. Under the optimal conditions in a shake culture, a maximum yield, productivity, and yield coefficient (on a weight basis to soybean oil supplied) of 142 g l(-1), 5.0 g l(-1) day(-1), and 0.5 g g(-1) were achieved by intermittent feeding of soybean oil and erythritol using the yeast. PMID:16733733

  5. Constrained Deformable-Layer Tomography

    Science.gov (United States)

    Zhou, H.

    2006-12-01

    The improvement on traveltime tomography depends on improving data coverage and tomographic methodology. The data coverage depends on the spatial distribution of sources and stations, as well as the extent of lateral velocity variation that may alter the raypaths locally. A reliable tomographic image requires large enough ray hit count and wide enough angular range between traversing rays over the targeted anomalies. Recent years have witnessed the advancement of traveltime tomography in two aspects. One is the use of finite frequency kernels, and the other is the improvement on model parameterization, particularly that allows the use of a priori constraints. A new way of model parameterization is the deformable-layer tomography (DLT), which directly inverts for the geometry of velocity interfaces by varying the depths of grid points to achieve a best traveltime fit. In contrast, conventional grid or cell tomography seeks to determine velocity values of a mesh of fixed-in-space grids or cells. In this study, the DLT is used to map crustal P-wave velocities with first arrival data from local earthquakes and two LARSE active surveys in southern California. The DLT solutions along three profiles are constrained using known depth ranges of the Moho discontinuity at 21 sites from a previous receiver function study. The DLT solutions are generally well resolved according to restoration resolution tests. The patterns of 2D DLT models of different profiles match well at their intersection locations. In comparison with existing 3D cell tomography models in southern California, the new DLT models significantly improve the data fitness. In comparison with the multi-scale cell tomography conducted for the same data, while the data fitting levels of the DLT and the multi-scale cell tomography models are compatible, the DLT provides much higher vertical resolution and more realistic description of the undulation of velocity discontinuities. The constraints on the Moho depth

  6. Preparation of intravenous cholesterol tracer using current good manufacturing practices.

    Science.gov (United States)

    Lin, Xiaobo; Ma, Lina; Racette, Susan B; Swaney, William P; Ostlund, Richard E

    2015-12-01

    Studies of human reverse cholesterol transport require intravenous infusion of cholesterol tracers. Because insoluble lipids may pose risk and because it is desirable to have consistent doses of defined composition available over many months, we investigated the manufacture of cholesterol tracer under current good manufacturing practice (CGMP) conditions appropriate for phase 1 investigation. Cholesterol tracer was prepared by sterile admixture of unlabeled cholesterol or cholesterol-d7 in ethanol with 20% Intralipid(®). The resulting material was filtered through a 1.2 micron particulate filter, stored at 4°C, and tested at time 0, 1.5, 3, 6, and 9 months for sterility, pyrogenicity, autoxidation, and particle size and aggregation. The limiting factor for stability was a rise in thiobarbituric acid-reacting substances of 9.6-fold over 9 months (P manufacturing methods can be achieved in the academic setting and need to be considered for critical components of future metabolic studies.

  7. Preparation of intravenous cholesterol tracer using current good manufacturing practices.

    Science.gov (United States)

    Lin, Xiaobo; Ma, Lina; Racette, Susan B; Swaney, William P; Ostlund, Richard E

    2015-12-01

    Studies of human reverse cholesterol transport require intravenous infusion of cholesterol tracers. Because insoluble lipids may pose risk and because it is desirable to have consistent doses of defined composition available over many months, we investigated the manufacture of cholesterol tracer under current good manufacturing practice (CGMP) conditions appropriate for phase 1 investigation. Cholesterol tracer was prepared by sterile admixture of unlabeled cholesterol or cholesterol-d7 in ethanol with 20% Intralipid(®). The resulting material was filtered through a 1.2 micron particulate filter, stored at 4°C, and tested at time 0, 1.5, 3, 6, and 9 months for sterility, pyrogenicity, autoxidation, and particle size and aggregation. The limiting factor for stability was a rise in thiobarbituric acid-reacting substances of 9.6-fold over 9 months (P manufacturing methods can be achieved in the academic setting and need to be considered for critical components of future metabolic studies. PMID:26416797

  8. Cholesterol monohydrate nucleation in ultrathin films on water

    DEFF Research Database (Denmark)

    Rapaport, H.; Kuzmenko, I.; Lafont, S.;

    2001-01-01

    The growth of a cholesterol crystalline phase, three molecular layers thick at the air-water interface, was monitored by grazing incidence x-ray diffraction and x-ray reflectivity. Upon compression, a cholesterol film transforms from a monolayer of trigonal symmetry and low crystallinity to a...... trilayer, composed of a highly crystalline bilayer in a rectangular lattice and a disordered top cholesterol layer. This system undergoes a phase transition into a crystalline trilayer incorporating ordered water between the hydroxyl groups of the top and middle sterol layers in an arrangement akin to the...... triclinic 3-D crystal structure of cholesterol . H(2)O. By comparison, the cholesterol derivative stigmasterol transforms, upon compression, directly into a crystalline trilayer in the rectangular lattice. These results may contribute to an understanding of the onset of cholesterol crystallization in...

  9. Apoprotein E genotype and the response of serum cholesterol to dietary fat, cholesterol and cafestol

    NARCIS (Netherlands)

    Weggemans, R.M.; Zock, P.L.; Ordovas, J.M.; Pedro-Botet, J.; Katan, M.B.

    2001-01-01

    Previous studies on the effect of apoprotein E (APOE) polymorphism on the response of serum lipids to diet showed inconsistent results. We therefore studied the effect of apoprotein E polymorphism on responses of serum cholesterol and lipoproteins to various dietary treatments. We combined data on r

  10. Percentage of Adults with High Cholesterol Whose LDL Cholesterol Levels Are Adequately Controlled

    Science.gov (United States)

    ... non-missing response to cholesterol questionnaire. Exclusion Criteria: Pregnant women. Estimates for 18-39 year olds were not ... for only one type of service, such as dental or vision care. Persons covered by ... and Prevention, National Center for Health Statistics from the National ...

  11. Activation of human antigen-presenting cells by the mycobacterial cord factor and its glycolipid adjuvant analogue trehalose-6,6’-dibehenate

    OpenAIRE

    Ostrop, Jenny

    2015-01-01

    The mycobacterial cord factor trehalose-6,6’-dimycolate (TDM) is an abundant cell wall glycolipid of Mycobacterium tuberculosis and other mycobacteria. It causes inflammation and adjuvanticity, but it is also a major virulence factor of M. tuberculosis. Its synthetic analogue trehalose-6,6’-dibehenate (TDB) has robust adjuvant activity and induces a Th1/Th17 T cell response in animal models. The TDB-containing liposomal adjuvant formulation Caf01 has entered phase I clinical studies in humans...

  12. Melittin-Lipid Bilayer Interactions and the Role of Cholesterol

    OpenAIRE

    Wessman, Per; Strömstedt, Adam A; Malmsten, Martin; Edwards, Katarina

    2008-01-01

    The membrane-destabilizing effect of the peptide melittin on phosphatidylcholine membranes is modulated by the presence of cholesterol. This investigation shows that inclusion of 40 mol % cholesterol in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine or 1,2-dioleoyl-sn-glycero-3-phosphocholine liposomes reduces melittin's affinity for the membrane. It is significant that the presence of cholesterol does not increase the amount of membrane-associated melittin needed to cause maximum leakage f...

  13. Interaction of Melittin with Membrane Cholesterol: A Fluorescence Approach

    OpenAIRE

    Raghuraman, H.; Chattopadhyay, Amitabha

    2004-01-01

    We have monitored the organization and dynamics of the hemolytic peptide melittin in membranes containing cholesterol by utilizing the intrinsic fluorescence properties of its functionally important sole tryptophan residue and circular dichroism spectroscopy. The significance of this study is based on the fact that the natural target for melittin is the erythrocyte membrane, which contains high amounts of cholesterol. Our results show that the presence of cholesterol inhibits melittin-induced...

  14. A review on lecithin:cholesterol acyltransferase deficiency.

    Science.gov (United States)

    Saeedi, Ramesh; Li, Min; Frohlich, Jiri

    2015-05-01

    Lecithin cholesterol acyl transferase (LCAT) is a plasma enzyme which esterifies cholesterol, and plays a key role in the metabolism of high-density lipoprotein cholesterol (HDL-C). Genetic disorders of LCAT are associated with lipoprotein abnormalities including low levels of HDL-C and presence of lipoprotein X, and clinical features mainly corneal opacities, changes in erythrocyte morphology and renal failure. Recombinant LCAT is being developed for the treatment of patients with LCAT deficiency. PMID:25172171

  15. Cholesterol esterification during differentiation of mouse erythroleukemia (Friend) cells

    Science.gov (United States)

    Mulas, Maria Franca; Mandas, Antonella; Abete, Claudia; Dessì, Sandra; Mocali, Alessandra; Paoletti, Francesco

    2011-01-01

    Cholesterol is an essential constituent of all mammalian cell membranes and its availability is therefore a prerequisite for cellular growth and other functions. Several lines of evidence are now indicating an association between alterations of cholesterol homeostasis and cell cycle progression. However, the role of cholesterol in cell differentiation is still largely unknown. To begin to address this issue, in this study we examined changes in cholesterol metabolism and in the mRNA levels of proteins involved in cholesterol import and esterification (multi-drug resistance, MDR-3) and acylCoA: cholesterol acyltransferase (ACAT) and cholesterol export (caveolin-1) in Friend virus-induced erythroleukemia cells (MELC), in the absence or in the presence of the chemical inducer of differentiation, hexamethylene bisacetamide (HMBA). FBS-stimulated growth of MELC was accompanied by an immediate elevation of cholesterol synthesis and cholesterol esterification, and by an increase in the levels of MDR-3 and ACAT mRNAs. A decrease in caveolin-1 expression was also observed. However, when MELC were treated with HMBA, the inhibition of DNA synthesis caused by HMBA treatment, was associated with a decrease in cholesterol esterification and in ACAT and MDR-3 mRNA levels and an increase in caveolin-1 mRNA. Detection of cytoplasmic neutral lipids by staining MELC with oil red O, a dye able to evidence CE but not FC, revealed that HMBA-treatment also reduced growth-stimulated accumulation of cholesterol ester to approximately the same extent as the ACAT inhibitor, SaH. Overall, these results indicate for the first time a role of cholesterol esterification and of some related genes in differentiation of erythroid cells. PMID:22184540

  16. Cholesterol esterification during differentiation of mouse erythroleukemia (Friend cells

    Directory of Open Access Journals (Sweden)

    Maria Franca Mulas

    2011-10-01

    Full Text Available Cholesterol is an essential constituent of all mammalian cell membranes, and its availability is therefore a prerequisite for cellular growth and other functions. Several lines of evidence are now indicating an association between alterations of cholesterol homeostasis and cell cycle progression. However, the role of cholesterol in cell differentiation is still largely unknown. To begin to address this issue, in this study we examined changes in cholesterol metabolism and in the mRNA levels of proteins involved in cholesterol import and esterification (multi-drug resistance, MDR-3 and acylCoA:cholesterol acyltransferase (ACAT and cholesterol export (caveolin-1 in Friend virus-induced erythroleukemia cells (MELC, in the absence or in the presence of the chemical inducer of differentiation, hexamethylene bisacetamide (HMBA. FBS-stimulated growth of MELC was accompanied by an immediate elevation of cholesterol synthesis and cholesterol esterification, and by an increase in the levels of MDR-3 and ACAT mRNAs. A decrease in caveolin-1 expression was also observed. However, when MELC were treated with HMBA, the inhibition of DNA synthesis caused by HMBA treatment, was associated with a decrease in cholesterol esterification and in ACAT and MDR-3 mRNA levels and an increase in caveolin-1 mRNA. Detection of cytoplasmic neutral lipids by staining MELC with oil red O, a dye able to evidence CE but not FC, revealed that HMBA-treatment also reduced growth-stimulated accumulation of cholesterol ester to approximately the same extent as the ACAT inhibitor, SaH. Overall, these results indicate for the first time a role of cholesterol esterification and of some related genes in differentiation of erythroid cells.

  17. Interaction of G protein coupled receptors and cholesterol.

    Science.gov (United States)

    Gimpl, Gerald

    2016-09-01

    G protein coupled receptors (GPCRs) form the largest receptor superfamily in eukaryotic cells. Owing to their seven transmembrane helices, large parts of these proteins are embedded in the cholesterol-rich plasma membrane bilayer. Thus, GPCRs are always in proximity to cholesterol. Some of them are functionally dependent on the specific presence of cholesterol. Over the last years, enormous progress on receptor structures has been achieved. While lipophilic ligands other than cholesterol have been shown to bind either inside the helix bundle or at the receptor-lipid interface, the binding site of cholesterol was either a single transmembrane helix or a groove between two or more transmembrane helices. A clear preference for one of the two membrane leaflets has not been observed. Not surprisingly, many hydrophobic residues (primarily leucine and isoleucine) were found to be involved in cholesterol binding. In most cases, the rough β-face of cholesterol contacted the transmembrane helix bundle rather than the surrounding lipid matrix. The polar hydroxy group of cholesterol was localized near the water-membrane interface with potential hydrogen bonding to residues in receptor loop regions. Although a canonical motif, designated as CCM site, was detected as a specific cholesterol binding site in case of the β2AR, this site was not found to be occupied by cholesterol in other GPCRs possessing the same motif. Cholesterol-receptor interactions can increase the compactness of the receptor structure and are able to enhance the conformational stability towards active or inactive receptor states. Overall, all current data suggest a high plasticity of cholesterol interaction sites in GPCRs. PMID:27108066

  18. CHOLESTEROL OXIDATION PRODUCTS IN MILK AND MILK PRODUCTS

    Directory of Open Access Journals (Sweden)

    A. Kemal SEÇKİN

    2004-02-01

    Full Text Available Cholesterol oxidation products (COPs are occurred by heat and light factors during processing, improper packaging and storage conditions. COPs are mutagenic, carcinogenity, cytotoxic, angiotoxic and damage to cell membrane and effect biosynthesis cholesterol in the metabolism . So, COPs have potential risk for public health. Also, in milk and milk products that have high cholesterol COPs can be also formed during processing and storage. Therefore it is necessary that measurements must be taken and standards must be in dairy about COPs.

  19. Cholesterol granuloma of the paratesticular tissue: A case report

    Science.gov (United States)

    Unal, Dursun; Kilic, Metin; Oner, Sedat; Erkinuresin, Taskın; Demirbas, Murat; Coban, Soner; Aydos, Mustafa Murat

    2015-01-01

    A 38-year-old man was admitted to our clinic with an enlarging right scrotal mass that had been present for 7 years. Right radical inguinal orchiectomy was performed and a histopathological diagnosis confirmed a very rare case of cholesterol granuloma of the paratesticular tissue. It can be very difficult to preoperatively distinguish testicular tumours from cholesterol granulomas of the testis or epididymis. Cholesterol granuloma should be kept in mind in patients with large and non-tender scrotal masses. PMID:26225185

  20. Alterations of serum cholesterol and serum lipoprotein in breast cancer of women

    OpenAIRE

    Hasija, Kiran; Bagga, Hardeep K.

    2005-01-01

    Fasting blood sample of 50 normal subjects (control) and 100 patients of breast cancer were investigated for serum total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, very low density lipoprotein, high density lipoprotein cholesterol:low density lipoprotein cholesterol ratio and total cholesterol:high density lipoprotein cholesterol ratio during breast cancer of women. Five cancer stages, types, age groups, parity and menopausal status were undertaken...

  1. Development of alimentary cholesterol in the plasma and the plasmatic lipoproteins in man, after ingestion of a meal containing octa-deuterated cholesterol; Devenir du cholesterol alimentaire dans le plasma et les lipoproteines plasmatiques chez l`homme, apres ingestion d`un repas contenant du cholesterol octa-deutere

    Energy Technology Data Exchange (ETDEWEB)

    Becue, T.; Ferezou, J.; Simon, G. [Paris-11 Univ., 91 - Orsay (France); Bernard, P.M.; Portugal, H. [Hopital Sainte-Marguerite, 13 - Marseille (France); Dubois, C.; Lairon, D.

    1994-12-31

    Cholesterol absorbed after a test-meal has two origins with man: the biliary cholesterol and the alimentary cholesterol. In order to understand the mechanism of the modification of cholesterol intestinal absorption by oat bran, the alimentary cholesterol has been labelled with octa-deuterated cholesterol, in test-diets. The kinetics of D-cholesterol in plasma and chylomicrons is described. 1 fig., 6 refs.

  2. Crystallogeny fundamentals of the cholesterol gallstone

    Institute of Scientific and Technical Information of China (English)

    Wu Jie; Zhou Jianli; He Lijun; Qu Xingang; Gu Lin; Yang Haimin

    2007-01-01

    The nucleation mechanism and crystal growth process of the cholesterol gallstone are studied and a systematic theory expounded by crystallogeny is proposed. Normal feed and stone-forming feed were used to raise guinea pigs in the control and stone-causing groups respectively. The state and transformation of liquid crystal vesicles, the appearance of crystal nuclei, and the formation of microcrystal grains were observed under a polarizing microscope during the experimental period. It was found that the liquid crystal vesicles in the bile of the control group were small, scattered, and always existed as single forms, and no shaped gallstone crystals were formed.While in the stone-causing group, liquid crystal vesicles grew to larger ones, and then aggregated to form large liquid crystal cells. Solid crystal growth along the edge of these liquid crystal cells formed microcrystal grains. These demonstrated that bile liquid crystal vesicles form the basic nuclei of cholesterol gallstone. Heterogeneous nucleation is the common process in the formation of crystal nuclei and crystal growth.

  3. High-density lipoprotein cholesterol: How High

    Directory of Open Access Journals (Sweden)

    G Rajagopal

    2012-01-01

    Full Text Available The high-density lipoprotein cholesterol (HDL-C is considered anti-atherogenic good cholesterol. It is involved in reverse transport of lipids. Epidemiological studies have found inverse relationship of HDL-C and coronary heart disease (CHD risk. When grouped according to HDL-C, subjects having HDL-C more than 60 mg/dL had lesser risk of CHD than those having HDL-C of 40-60 mg/dL, who in turn had lesser risk than those who had HDL-C less than 40 mg/dL. No upper limit for beneficial effect of HDL-C on CHD risk has been identified. The goals of treating patients with low HDL-C have not been firmly established. Though many drugs are known to improve HDL-C concentration, statins are proven to improve CHD risk and mortality. Cholesteryl ester transfer protein (CETP is involved in metabolism of HDL-C and its inhibitors are actively being screened for clinical utility. However, final answer is still awaited on CETP-inhibitors.

  4. Specific Ion Effects in Cholesterol Monolayers

    Directory of Open Access Journals (Sweden)

    Teresa Del Castillo-Santaella

    2016-05-01

    Full Text Available The interaction of ions with interfaces and, in particular, the high specificity of these interactions to the particular ions considered, are central questions in the field of surface forces. Here we study the effect of different salts (NaI, NaCl, CaCl2 and MgCl2 on monolayers made of cholesterol molecules, both experimentally (surface area vs. lateral pressure isotherms measured by a Langmuir Film Balance and theoretically (molecular dynamics (MD all-atomic simulations. We found that surface isotherms depend, both quantitatively and qualitatively, on the nature of the ions by altering the shape and features of the isotherm. In line with the experiments, MD simulations show clear evidences of specific ionic effects and also provide molecular level details on ion specific interactions with cholesterol. More importantly, MD simulations show that the interaction of a particular ion with the surface depends strongly on its counterion, a feature ignored so far in most theories of specific ionic effects in surface forces.

  5. A Dynamic Programming Approach to Constrained Portfolios

    DEFF Research Database (Denmark)

    Kraft, Holger; Steffensen, Mogens

    2013-01-01

    This paper studies constrained portfolio problems that may involve constraints on the probability or the expected size of a shortfall of wealth or consumption. Our first contribution is that we solve the problems by dynamic programming, which is in contrast to the existing literature that applies...... the martingale method. More precisely, we construct the non-separable value function by formalizing the optimal constrained terminal wealth to be a (conjectured) contingent claim on the optimal non-constrained terminal wealth. This is relevant by itself, but also opens up the opportunity to derive new solutions...

  6. Cholesterol assimilation by Lactobacillus probiotic bacteria: an in vitro investigation.

    Science.gov (United States)

    Tomaro-Duchesneau, Catherine; Jones, Mitchell L; Shah, Divya; Jain, Poonam; Saha, Shyamali; Prakash, Satya

    2014-01-01

    Excess cholesterol is associated with cardiovascular diseases (CVD), an important cause of mortality worldwide. Current CVD therapeutic measures, lifestyle and dietary interventions, and pharmaceutical agents for regulating cholesterol levels are inadequate. Probiotic bacteria have demonstrated potential to lower cholesterol levels by different mechanisms, including bile salt hydrolase activity, production of compounds that inhibit enzymes such as 3-hydroxy-3-methylglutaryl coenzyme A, and cholesterol assimilation. This work investigates 11 Lactobacillus strains for cholesterol assimilation. Probiotic strains for investigation were selected from the literature: Lactobacillus reuteri NCIMB 11951, L. reuteri NCIMB 701359, L. reuteri NCIMB 702655, L. reuteri NCIMB 701089, L. reuteri NCIMB 702656, Lactobacillus fermentum NCIMB 5221, L. fermentum NCIMB 8829, L. fermentum NCIMB 2797, Lactobacillus rhamnosus ATCC 53103 GG, Lactobacillus acidophilus ATCC 314, and Lactobacillus plantarum ATCC 14917. Cholesterol assimilation was investigated in culture media and under simulated intestinal conditions. The best cholesterol assimilator was L. plantarum ATCC 14917 (15.18±0.55 mg/10(10) cfu) in MRS broth. L. reuteri NCIMB 701089 assimilated over 67% (2254.70±63.33 mg/10(10) cfu) of cholesterol, the most of all the strains, under intestinal conditions. This work demonstrates that probiotic bacteria can assimilate cholesterol under intestinal conditions, with L. reuteri NCIMB 701089 showing great potential as a CVD therapeutic. PMID:25295259

  7. Cholesterol Assimilation by Lactobacillus Probiotic Bacteria: An In Vitro Investigation

    Directory of Open Access Journals (Sweden)

    Catherine Tomaro-Duchesneau

    2014-01-01

    Full Text Available Excess cholesterol is associated with cardiovascular diseases (CVD, an important cause of mortality worldwide. Current CVD therapeutic measures, lifestyle and dietary interventions, and pharmaceutical agents for regulating cholesterol levels are inadequate. Probiotic bacteria have demonstrated potential to lower cholesterol levels by different mechanisms, including bile salt hydrolase activity, production of compounds that inhibit enzymes such as 3-hydroxy-3-methylglutaryl coenzyme A, and cholesterol assimilation. This work investigates 11 Lactobacillus strains for cholesterol assimilation. Probiotic strains for investigation were selected from the literature: Lactobacillus reuteri NCIMB 11951, L. reuteri NCIMB 701359, L. reuteri NCIMB 702655, L. reuteri NCIMB 701089, L. reuteri NCIMB 702656, Lactobacillus fermentum NCIMB 5221, L. fermentum NCIMB 8829, L. fermentum NCIMB 2797, Lactobacillus rhamnosus ATCC 53103 GG, Lactobacillus acidophilus ATCC 314, and Lactobacillus plantarum ATCC 14917. Cholesterol assimilation was investigated in culture media and under simulated intestinal conditions. The best cholesterol assimilator was L. plantarum ATCC 14917 (15.18 ± 0.55 mg/1010 cfu in MRS broth. L. reuteri NCIMB 701089 assimilated over 67% (2254.70 ± 63.33 mg/1010 cfu of cholesterol, the most of all the strains, under intestinal conditions. This work demonstrates that probiotic bacteria can assimilate cholesterol under intestinal conditions, with L. reuteri NCIMB 701089 showing great potential as a CVD therapeutic.

  8. Aspirin inhibits formation of cholesterol rafts in fluid lipid membranes.

    Science.gov (United States)

    Alsop, Richard J; Toppozini, Laura; Marquardt, Drew; Kučerka, Norbert; Harroun, Thad A; Rheinstädter, Maikel C

    2015-03-01

    Aspirin and other non-steroidal anti-inflammatory drugs have a high affinity for phospholipid membranes, altering their structure and biophysical properties. Aspirin has been shown to partition into the lipid head groups, thereby increasing membrane fluidity. Cholesterol is another well known mediator of membrane fluidity, in turn increasing membrane stiffness. As well, cholesterol is believed to distribute unevenly within lipid membranes leading to the formation of lipid rafts or plaques. In many studies, aspirin has increased positive outcomes for patients with high cholesterol. We are interested if these effects may be, at least partially, the result of a non-specific interaction between aspirin and cholesterol in lipid membranes. We have studied the effect of aspirin on the organization of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) membranes containing cholesterol. Through Langmuir-Blodgett experiments we show that aspirin increases the area per lipid and decreases compressibility at 32.5 mol% cholesterol, leading to a significant increase of fluidity of the membranes. Differential scanning calorimetry provides evidence for the formation of meta-stable structures in the presence of aspirin. The molecular organization of lipids, cholesterol and aspirin was studied using neutron diffraction. While the formation of rafts has been reported in binary DPPC/cholesterol membranes, aspirin was found to locally disrupt membrane organization and lead to the frustration of raft formation. Our results suggest that aspirin is able to directly oppose the formation of cholesterol structures through non-specific interactions with lipid membranes.

  9. Transfer of cholesterol from macrophages to lymphocytes in culture.

    Science.gov (United States)

    de Bittencourt Júnior, P I; Curi, R

    1998-02-01

    A major feature of macrophage metabolism is its capacity to produce and export cholesterol. Several reports have shown that the manipulation of lymphocyte cholesterol content elicits important changes in lymphocyte proliferation. These findings lead to an inquiry as to whether macrophage-derived cholesterol released into the lymphocyte surroundings may be transferred to the latter thus affecting lymphocyte function. In this study, cholesterol transfer from macrophages to lymphocytes was examined in vitro using rat cells in culture. The findings indicate that there may be a significant transfer of cholesterol from [4-14C]cholesterol labeled resident peritoneal macrophages to mesenteric lymph node resting lymphocytes (up to 173.9 +/- 2.7 pmol/10(7) lymphocytes/10(7) macrophages when co-cultivated for 48 h), in a lipoprotein-dependent manner. This represents the mass transfer of ca. 17 nmoles of cholesterol molecules per 10(7) lymphocytes from 10(7) macrophages (calculated on the basis of specific radioactivity incorporated into macrophages after the pre-labelling period), which suggests that macrophages are capable of replacing the whole lymphocyte cholesterol pool every 21 h. Moreover, an 111%-increase in the total cholesterol content of lymphocytes was found after co-cultivation with macrophages for 48 h. When compared to peritoneal cells, monocytes/macrophages obtained from circulating blood leukocytes presented a much higher cholesterol transfer capacity to lymphocytes (3.06 +/- 0.10 nmol/10(7) lymphocytes/10(7) macrophages co-cultivated for 24 h). Interestingly, inflammatory macrophages dramatically reduced their cholesterol transfer ability (by up to 91%, as compared to resident macrophages). Cholesterol transfer may involve a humoral influence, since it is not only observed when cells are co-cultivated in a single-well chamber system (cells in direct contact), but also in a two-compartment system (where cells can communicate but not by direct contact). Co

  10. Determination of cholesterol in human biliary calculus by TLC scanning

    Institute of Scientific and Technical Information of China (English)

    Yin Kang Yang; Kai Xiong Qiu; Yu Zhu Zhan; Er Yi Zhan; Hai Ming Yang; Ping Zheng

    2000-01-01

    AIM To study the physico-chemical properties of biliary calculus and the relationship between the calculusformation and the phase change of liquid crystal, providing the best evidence for the biliary calculusprevention and treatment.METHODS The cholesterol contents in thirty one cases of biliary calculus in Kunming were determined bydouble-wave-length TLC scanning with high efficiency silica gel films.RESULTS Under magnifiers, the granular biliary calculus from 31 patients were classified according totheir section structures and colours, as cholesterol cholelith, 25 cases; bilirubin cholelith, 4 cases andcompound cholelith, 2 cases. By TLC scanning, it was found that the content of cholesterol in human biliarycalculus was 71%- 100%, about 80% cholesterol bilestones whose cholesterol content was more than 90%being pure cholesterol bilestones.CONCLUSION Cholesterol bilestone is the main human biliary calculus in Kunming, which was inaccordance with X-ray analysis. Compared with the related reports, it is proved that the proportion ofcholesterol bilestones to biliary calculus is increasing because of the improved life standard and the decreaseof bilirubin bilestones resulted from bile duct ascariasis or bacteria infection in China since 90s, and that theincrease of cholesterol in-take leads to the increase of cholesterol metabolism disorder

  11. Cholesterol granuloma of the petrous apex: CT diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Lo, W.W.M.; Solti-Bohman, L.G.; Brackmann, D.E.; Gruskin, P.

    1984-12-01

    Cholesterol granuloma of the petrous apex is a readily recognizable and treatable entity that is more common than previously realized. Cholesterol granuloma grows slowly in the petrous apex as a mass lesion until it produces hearing loss, tinnitus, vertigo, and facial twitching. Twelve cases of cholesterol granuloma of the petrous apex are illustrated; ten of these analyzed in detail, especially with respect to CT findings. A sharply and smoothly marginated expansile lesion in the petrous apex, isodense with plain and nonenhancing on CT, is in all probability a cholesterol granuloma. Preoperative recognition by CT is important for planning proper treatment.

  12. Cholesterol and Copper Affect Learning and Memory in the Rabbit

    Directory of Open Access Journals (Sweden)

    Bernard G. Schreurs

    2013-01-01

    Full Text Available A rabbit model of Alzheimer’s disease based on feeding a cholesterol diet for eight weeks shows sixteen hallmarks of the disease including beta amyloid accumulation and learning and memory changes. Although we have shown that feeding 2% cholesterol and adding copper to the drinking water can retard learning, other studies have shown that feeding dietary cholesterol before learning can improve acquisition and feeding cholesterol after learning can degrade long-term memory. We explore the development of this model, the issues surrounding the role of copper, and the particular contributions of the late D. Larry Sparks.

  13. New horizons for cholesterol ester transfer protein inhibitors.

    Science.gov (United States)

    Schwartz, Gregory G

    2012-02-01

    High-density lipoprotein (HDL) cholesterol levels bear an inverse relationship to cardiovascular risk. To date, however, no intervention specifically targeting HDL has been demonstrated to reduce cardiovascular risk. Cholesterol ester transfer protein (CETP) mediates transfer of cholesterol ester from HDL to apolipoprotein B-containing particles. Most, but not all observational cohort studies indicate that genetic polymorphisms of CETP associated with reduced activity and higher HDL cholesterol levels are also associated with reduced cardiovascular risk. Some, but not all studies indicate that CETP inhibition in rabbits retards atherosclerosis, whereas transgenic CETP expression in mice promotes atherosclerosis. Torcetrapib, the first CETP inhibitor to reach phase III clinical development, was abandoned due to excess mortality associated with increases in aldosterone and blood pressure. Two other CETP inhibitors have entered phase III clinical development. Anacetrapib is a potent inhibitor of CETP that produces very large increases in HDL cholesterol and large reductions in low-density lipoprotein (LDL) cholesterol, beyond those achieved with statins. Dalcetrapib is a less potent CETP inhibitor that produces smaller increases in HDL cholesterol with minimal effect on LDL cholesterol. Both agents appear to allow efflux of cholesterol from macrophages to HDL in vitro, and neither agent affects blood pressure or aldosterone in vivo. Two large cardiovascular outcomes trials, one with anacetrapib and one with dalcetrapib, should provide a conclusive test of the hypothesis that inhibition of CETP decreases cardiovascular risk. PMID:22083134

  14. Retracted: Advances in the physiological and pathological implications of cholesterol.

    Science.gov (United States)

    Cortes, Victor A; Busso, Dolores; Mardones, Pablo; Maiz, Alberto; Arteaga, Antonio; Nervi, Flavio; Rigotti, Attilio

    2013-11-01

    Cholesterol has evolved to fulfill sophisticated biophysical, cell signalling, and endocrine functions in animal systems. At the cellular level, cholesterol is found in membranes where it increases both bilayer stiffness and impermeability to water and ions. Furthermore, cholesterol is integrated into specialized lipid-protein membrane microdomains with critical topographical and signalling functions. At the organismal level, cholesterol is the precursor of all steroid hormones, including gluco- and mineralo-corticoids, sex hormones, and vitamin D, which regulate carbohydrate, sodium, reproductive, and bone homeostasis, respectively. This sterol is also the immediate precursor of bile acids, which are important for intestinal absorption of dietary lipids as well as energy homeostasis and glucose regulation. Complex mechanisms maintain cholesterol within physiological ranges and the dysregulation of these mechanisms results in embryonic or adult diseases, caused by either excessive or reduced tissue cholesterol levels. The causative role of cholesterol in these conditions has been demonstrated by genetic and pharmacological manipulations in animal models of human disease that are discussed herein. Importantly, the understanding of basic aspects of cholesterol biology has led to the development of high-impact pharmaceutical therapies during the past century. The continuing effort to offer successful treatments for prevalent cholesterol-related diseases, such as atherosclerosis and neurodegenerative disorders, warrants further interdisciplinary research in the coming decades. PMID:23445165

  15. Reconstitution of Cholesterol-Dependent Vaginolysin into Tethered Phospholipid Bilayers

    DEFF Research Database (Denmark)

    Budvytyte, Rima; Pleckaityte, M.; Zvirbliene, A.;

    2013-01-01

    Functional reconstitution of the cholesterol-dependent cytolysin vaginolysin (VLY) from Gardnerella vaginalis into artificial tethered bilayer membranes (tBLMs) has been accomplished. The reconstitution of VLY was followed in real-time by electrochemical impedance spectroscopy (EIS). Changes of the...... EIS parameters of the tBLMs upon exposure to VLY solutions were consistent with the formation of water-filled pores in the membranes. It was found that reconstitution of VLY is a strictly cholesterol-dependent, irreversible process. At a constant cholesterol concentration reconstitution of VLY...... platform for the detection of the activity of VLY and possibly other cholesterol-dependent cytolysins....

  16. Effect of doxazosin on cholesterol synthesis in cell culture

    Energy Technology Data Exchange (ETDEWEB)

    D' Eletto, R.D.; Javitt, N.B.

    1989-01-01

    The effect of doxazosin on cholesterol synthesis was determined by measuring the content of deuterium-enriched cholesterol in rabbit fibroblasts with and without receptors for low-density lipoproteins (LDL) and in hepatoma (Hep G2 cells). Doxazosin, at concentrations of 5-20 mumol/L, increased LDL binding to hepatic cells in a dose-related manner. Also, in these hepatic cells, doxazosin produced dose-related decreases in both newly synthesized cholesterol and cholesterol ester. In rabbit fibroblasts that were LDL receptor negative, de novo cholesterol synthesis was markedly reduced by increasing concentrations of doxazosin. Taken together, these results suggest that doxazosin may have a direct inhibitory effect on cholesterol synthesis independent of the LDL receptor. The inhibition of cholesterol synthesis by doxazosin may cause cells to compensate by upregulating the LDL receptor, thereby increasing the importation of lipoprotein cholesterol and reducing LDL cholesterol in the medium. This hypothesis supports findings in the clinical setting whereby doxazosin has a beneficial effect on the lipid profile, and suggests a useful additional property for this antihypertensive agent.

  17. Apoprotein E phenotype determines serum cholesterol in infants during both high-cholesterol breast feeding and low-cholesterol formula feeding.

    Science.gov (United States)

    Kallio, M J; Salmenperä, L; Siimes, M A; Perheentupa, J; Gylling, H; Miettinen, T A

    1997-04-01

    Our objective was to establish the role of the apoprotein (apo) E phenotype in determining serum cholesterol levels in infants fed exclusively on high-fat, high-cholesterol human milk and in those fed a low-cholesterol, high-unsaturated fat formula. The total and lipoprotein cholesterol, apoB, and triglyceride concentrations in serum were quantified and related to the apoE phenotype in 151 infants at birth and at 2, 6, 9, and 12 months of age. Forty-four had the E3/4 or 4/4 phenotype (E4 group), 94 had the E3/3 phenotype (E3 group), and 13 had the E2/3 or 2/4 phenotype (E2 group). In cord blood, cholesterol concentrations tended to be higher in the E4 than in the E2 group. With exclusive breast-feeding, the concentrations rose significantly faster and higher in the E4 group than in the E3 group or, especially, the E2 group. The values (mmol/L, mean +/- SEM) were 1.6 +/- 0.15, 1.5 +/- 0.05, 1.4 +/- 0.1 (P = n.s.) at birth; 4.2 +/- 0.1, 3.8 +/- 0.08, 3.4 +/- 0.2 (P HDL, HDL2, and HDL3 cholesterol concentrations did not depend on the apoE phenotype. Among infants fed high-fat, high-cholesterol human milk, the total and LDL-cholesterol concentrations and the LDL apoB concentration of those with the apoE phenotype 4/4 or 3/4 rose faster and to higher levels than in other infants. Among formula-fed infants, receiving a low-cholesterol, high-unsaturated fat diet, the differences between the apoE groups were smaller.

  18. Saturated fatty acid (SFA) status and SFA intake exhibit different relations with serum total cholesterol and lipoprotein cholesterol : a mechanistic explanation centered around lifestyle-induced low-grade inflammation

    NARCIS (Netherlands)

    Ruiz Nunez, Begona; Kuipers, Remko S.; Luxwolda, Martine F.; De Graaf, Deti J.; Breeuwsma, Benjamin B.; Dijck-Brouwer, Janneke; Muskiet, Frits A. J.

    2014-01-01

    We investigated the relations between fatty acid status and serum total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein (HDL) cholesterol and total cholesterol/HDL cholesterol ratio in five Tanzanian ethnic groups and one Dutch group. Total cholesterol/HDL cholesterol rati

  19. Asymptotic Likelihood Distribution for Correlated & Constrained Systems

    CERN Document Server

    Agarwal, Ujjwal

    2016-01-01

    It describes my work as summer student at CERN. The report discusses the asymptotic distribution of the likelihood ratio for total no. of parameters being h and 2 out of these being are constrained and correlated.

  20. Cholesterol efflux via ATP-binding cassette transporter A1 (ABCA1) and cholesterol uptake via the LDL receptor influences cholesterol-induced impairment of beta cell function in mice

    NARCIS (Netherlands)

    Kruit, J. K.; Kremer, P. H. C.; Dai, L.; Tang, R.; Ruddle, P.; de Haan, W.; Brunham, L. R.; Verchere, C. B.; Hayden, M. R.

    2010-01-01

    Cellular cholesterol accumulation is an emerging mechanism for beta cell dysfunction in type 2 diabetes. Absence of the cholesterol transporter ATP-binding cassette transporter A1 (ABCA1) results in increased islet cholesterol and impaired insulin secretion, indicating that impaired cholesterol effl

  1. Assessment of modes of action and efficacy of plasma cholesterol-lowering drugs : measurement of cholesterol absorption, cholesterol synthesis and bile acid synthesis and turnover using novel stable isotope techniques

    NARCIS (Netherlands)

    Stellaard, Frans; Kuipers, Folkert

    2005-01-01

    Several processes are involved in control of plasma cholesterol levels, e.g., intestinal cholesterol absorption, endogenous cholesterol synthesis and transport and bile acid synthesis. Adaptation of either of these processes allows the body to adapt to changes in dietary cholesterol intake. Disturba

  2. Constrained school choice : an experimental study

    OpenAIRE

    Calsamiglia, Caterina; Haeringer, Guillaume; Klijn, Flip

    2008-01-01

    The literature on school choice assumes that families can submit a preference list over all the schools they want to be assigned to. However, in many real-life instances families are only allowed to submit a list containing a limited number of schools. Subjects' incentives are drastically affected, as more individuals manipulate their preferences. Including a safety school in the constrained list explains most manipulations. Competitiveness across schools plays an important role. Constraining...

  3. Influence of length and conformation of saccharide head groups on the mechanics of glycolipid membranes: Unraveled by off-specular neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Akihisa, E-mail: ayamamoto@icems.kyoto-u.ac.jp, E-mail: tanaka@uni-heidelberg.de; Tanaka, Motomu, E-mail: ayamamoto@icems.kyoto-u.ac.jp, E-mail: tanaka@uni-heidelberg.de [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8501 (Japan); Abuillan, Wasim; Körner, Alexander [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Burk, Alexandra S. [Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg (Germany); Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany); Ries, Annika [Institute of Organic and Biomolecular Chemistry, University of Göttingen, 37077 Göttingen (Germany); Werz, Daniel B. [Institute of Organic Chemistry, Technische Universität Braunschweig, 38106 Braunschweig (Germany); Demé, Bruno [Institut Laue-Langevin, 38042 Grenoble Cedex 9, Grenoble (France)

    2015-04-21

    The mechanical properties of multilayer stacks of Gb3 glycolipid that play key roles in metabolic disorders (Fabry disease) were determined quantitatively by using specular and off-specular neutron scattering. Because of the geometry of membrane stacks deposited on planar substrates, the scattered intensity profile was analyzed in a 2D reciprocal space map as a function of in-plane and out-of-plane scattering vector components. The two principal mechanical parameters of the membranes, namely, bending rigidity and compression modulus, can be quantified by full calculation of scattering functions with the aid of an effective cut-off radius that takes the finite sample size into consideration. The bulkier “bent” Gb3 trisaccharide group makes the membrane mechanics distinctly different from cylindrical disaccharide (lactose) head groups and shorter “bent” disaccharide (gentiobiose) head groups. The mechanical characterization of membranes enriched with complex glycolipids has high importance in understanding the mechanisms of diseases such as sphingolipidoses caused by the accumulation of non-degenerated glycosphingolipids in lysosomes or inhibition of protein synthesis triggered by the specific binding of Shiga toxin to Gb3.

  4. LDL Cholesterol, Statins And PCSK 9 Inhibitors

    Science.gov (United States)

    Gupta, Sanjiv

    2015-01-01

    Reduction of low density lipoprotein cholesterol (LDLc) is of vital importance for the prevention of atherosclerotic cardiovascular disease (ASCVD). Statin is the most effective therapy today to lower LDLc by inhibiting HMG-CoA-reductase. However despite intensive statin therapy, there remains a residual risk of recurrent myocardial infarction in about 20–30% cases. Moreover a few patients develop statin intolerance. For severe hypercholesterolemia, statins alone or in combination of ezetimibe, niacin and fenofibrate have been advocated. For homozygous familial hypercholesterolemia (HOFH), a microsomal triglyceride transfer protein MTP inhibitor (Lopitamide) and antisense oligonucleotide (ASO) (Mipomersen) have recently been approved by FDA, USA through ‘Risk evaluation and Mitigation Strategy (REMS)’. Possible future therapies include PCSK-9 inhibitors which have excellent lipid lowering properties. Three monoclonal antibodies (PCSK 9 Inhibitors) alirocumab, evolocumab and Bococizumab are under advanced clinical stage IV trials and awaiting approval by FDA and European Medicines Agency. PMID:26432726

  5. Cholesterol interactions with ceramide and sphingomyelin.

    Science.gov (United States)

    García-Arribas, Aritz B; Alonso, Alicia; Goñi, Felix M

    2016-09-01

    Sphingolipids contain in their polar heads chemical groups allowing them to establish a complex network of H-bonds (through different OH and NHgroups) with other lipids in the bilayer. In the recent years the specific interaction of sphingomyelin (SM) with cholesterol (Chol) has been examined, largely in the context of the "lipid raft" hypothesis. Formation of SM-Ceramide (Cer) complexes, proposed to exist in cell membranes in response to stress, has also been described. More recently, a delicate balance of phase formation and transformation in ternary mixtures of SM, Chol and Cer, with mutual displacement of Chol and Cer from their interaction with SM is considered to exist. In addition, data demonstrating direct Chol-Cer interaction are becoming available. PMID:27132117

  6. Serum cholesterol decline and depression in the postpartum period

    NARCIS (Netherlands)

    Dam, van R.M.; Schuit, A.J.; Schouten, E.G.; Vader, H.L.; Pop, V.J.M.

    1999-01-01

    We examined the relation between total serum cholesterol decline and depression in the postpartum period in a prospective study of 266 Dutch women, who were followed until 34 weeks after delivery. The decline in serum cholesterol between week 32 of pregnancy and week 10 postpartum was similar for wo

  7. The ins and outs of reverse cholesterol transport

    NARCIS (Netherlands)

    Groen, AK; Elferink, RPJO; Verkade, HJ; Kuipers, F

    2004-01-01

    It is generally assumed that HDL is the obligate transport vehicle for 'reverse cholesterol transport'. the pathway for removal of excess cholesterol from peripheral tissues via the liver into bile and subsequent excretion via the feces. During the last few years, intensive research has generated ex

  8. CDC Vital Signs: High Blood Pressure and Cholesterol

    Science.gov (United States)

    ... 1.36 MB] Read the MMWR Science Clips High Blood Pressure and Cholesterol Out of Control Recommend on Facebook ... by County http://apps.nccd.cdc.gov/GISCVH2/ High Blood Pressure and High Cholesterol Among US Adults SOURCES: National ...

  9. Low serum cholesterol, serotonin metabolism, and violent death

    NARCIS (Netherlands)

    P.H.A. Steegmans

    1995-01-01

    textabstractA high serum cholesterol level is a well documented risk factor for atherosclerotic cardiovascular disease. Consequently, a low serum cholesterol has in general been viewed as beneficial. However, since the early 70s, results from several cohort studies and randomized trials have suggest

  10. Cholesterol Check (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2015-09-10

    High blood cholesterol is a risk factor for cardiovascular disease. This podcast discusses the importance of a healthy diet and regular cholesterol screening.  Created: 9/10/2015 by MMWR.   Date Released: 9/10/2015.

  11. Composition of and cholesterol in Araucana and commercial eggs.

    Science.gov (United States)

    Peterson, D W; Lilyblade, A; Clifford, C K; Ernst, R; Clifford, A J; Dunn, P

    1978-01-01

    Araucana eggs from six sources and commercial-type white eggs of two major supermarket brands and from the University of California flock were collected and analyzed for cholesterol content of the yolk. The yolks of Araucana eggs were significantly higher in cholesterol than those of commercial white eggs. PMID:563887

  12. Transport of cholesterol autoxidation products in rabbit lipoproteins

    International Nuclear Information System (INIS)

    Radiolabeled pure [4-14C] cholesterol was kept at 600C under air to autoxidize for 5 weeks, after which approximately 12% cholesterol oxidation products were formed. The mixture, suspended in gelatin, was given to rabbits by gastric gavage. Rabbits were killed 4, 24 and 48 h after treatment. Cholesterol and its autoxidation products were separated by thin-layer chromatography into 5 fractions and radioactivities of each fraction were measured. Percentages of each fraction of cholesterol oxidation products and cholesterol in the original mixture before administration and in the rabbit sera after administration were similar, suggesting that the rates of absorption of cholesterol oxidation products are not significantly different from that of cholesterol. Lipoproteins were fractioned by ultracentrifugation into VLDL, LDL and HDL. Radioactivities of each fraction in lipoproteins separated by thin layer chromatography showed that fractions containing cholestane-3β, 5α, 6β-triol, 7α- and 7β-hydroxycholesterol and 7-ketocholesterol were more selectively transported in VLDL, whereas most of the 25-hydroxycholesterol was present in LDL. HDL contained only minute amounts of cholesterol oxidation products. 22 refs

  13. LDL cholesterol still a problem in old age?

    DEFF Research Database (Denmark)

    Postmus, Iris; Deelen, Joris; Sedaghat, Sanaz;

    2015-01-01

    BACKGROUND: Observational studies in older subjects have shown no or inverse associations between cholesterol levels and mortality. However, in old age plasma low-density lipoprotein cholesterol (LDL-C) may not reflect the lifetime level due to reverse causality, and hence the risk may be underes...

  14. Cholesterol and Sphingomyelin-Containing Model Condensed Lipid Monolayers: Heterogeneities Involving Ordered Microdomains Assessed by Two Cholesterol Derivatives.

    Science.gov (United States)

    Lecompte, Marie-France; Gaibelet, Gérald; Lebrun, Chantal; Tercé, François; Collet, Xavier; Orlowski, Stéphane

    2015-11-01

    Lipid monolayers are often considered as model membranes, but they are also the physiologic lipid part of the peripheral envelope of lipoproteins and cytosolic lipid bodies. However, their structural organization is still rather elusive, in particular when both cholesterol and sphingomyelin are present. To investigate such structural organization of hemimembranes, we measured, using alternative current voltammetry, the differential capacitance of condensed phosphatidylcholine-based monolayers as a function of applied potential, which is sensitive to their lipid composition and molecular arrangement. Especially, monolayers containing both sphingomyelin and cholesterol, at 15% w/w, presented specific characteristics of the differential capacitance versus potential curves recorded, which was indicative of specific interactions between these two lipid components. We then compared the behavior of two cholesterol derivatives (at 15% w/w), 21-methylpyrenyl-cholesterol (Pyr-met-Chol) and 22-nitrobenzoxadiazole-cholesterol (NBD-Chol), with that of cholesterol when present in model monolayers. Indeed, these two probes were chosen because of previous findings reporting opposite behaviors within bilayer membranes regarding their interaction with ordered lipids, with only Pyr-met-Chol mimicking cholesterol well. Remarkably, in monolayers containing sphingomyelin or not, Pyr-met-Chol and NBD-Chol presented contrasting behaviors, and Pyr-met-Chol mimicked cholesterol only in the presence of sphingomyelin. These two observations (i.e., optimal amounts of sphingomyelin and cholesterol, and the ability to discriminate between Pyr-met-Chol and NBD-Chol) can be interpreted by the existence of heterogeneities including ordered patches in sphingomyelin- and cholesterol-containing monolayers. Since such monolayer lipid arrangement shares some properties with the raft-type lipid microdomains well-described in sphingomyelin- and cholesterol-containing bilayer membranes, our data thus

  15. Ursodeoxycholic Acid for the Treatment of Cholesterol Gallstones

    International Nuclear Information System (INIS)

    Cholesterol is the principal constituent of more than three quarters of gallstones. Pure cholesterol crystals are quite soft, and protein contributes importantly to the strength of cholesterol stones. The risk of gallstones does not correlate with total serum cholesterol levels, but it does correlate with decreased high-density lipoprotein cholesterol and increased triglyceride levels. At least 10 percent of adults have gallstones where female: male ratio of about 2:1 in the younger age groups with increasing prevalence with age. Nine patients with gallstones (6 females and 3 males) were included in the study. Patients were treated with ursodeoxycholic acids tablets in two oral doses, one after breakfast, and the other after dinner for 9 months. Ultrasound examination was repeated every 3 months. Re-examination by abdominal ultrasonography revealed that gallstone 1 cm or less in diameter disappeared within 6 months, and the largest stone 3.06 cm in diameter disappeared within 9 months.

  16. Enzymatic-fluorometric quantification of cholesterol in bovine milk

    DEFF Research Database (Denmark)

    Larsen, Torben

    2012-01-01

    The present paper describes an enzymatic–fluorometric method for the determination of cholesterol in milk and other opaque matrices. The initial step of the method is to liberate chemically and physically bound cholesterol from the milk fat globule membrane by enzymatic action. The method is able...... to discriminate between esterified and free cholesterol in milk. The analysis is cost effective and is developed to work directly on whole, fresh milk thereby eliminating time consuming and tedious pre-treatment procedures of the sample. More than 1000 milk samples were analysed on the day of sampling. The total...... concentration of milk cholesterol ranged from 80 to 756 μM (n = 1068; mean 351 μM). Milk cholesterol was significantly correlated to milk fat concentration as analysed by mid-infra red spectrometry (r = 0.630; n = 853) and by an enzymatic–fluorometric method (triacylglycerol) (r = 0.611; n = 842)....

  17. Bad cholesterol and good mood: exploring the link

    Directory of Open Access Journals (Sweden)

    Yashaswi Gupta

    2016-01-01

    Full Text Available It is a well-known fact that high cholesterol increases the risks of heart disease. Hence, physicians actively encourage cholesterol-lowering interventions using medications and lifestyle modifications. However, there is considerable evidence that aggressive lowering of cholesterol is associated with depression, bipolar disorders, violent behaviour, and suicidal ideation. It has been hypothesised that low cholesterol leads to low levels of serotonin, a chemical that is responsible for maintaining mood balance. South Korea and India have highest number of suicides in Asia. It is a significant challenge for physicians to search an alternative that will not only maintain healthy level of cholesterol, but also contribute to psychological well-being of the patient. Generally, the role of diet and physical activity is considered secondary to medications. However, dietary supplements like coenzyme Q10 (CoQ10, omega-3 fatty acids, niacin, and physical activity like Yoga are extremely beneficial for improving lipid profile and symptoms of depression.

  18. SND1 overexpression deregulates cholesterol homeostasis in hepatocellular carcinoma.

    Science.gov (United States)

    Navarro-Imaz, Hiart; Rueda, Yuri; Fresnedo, Olatz

    2016-09-01

    SND1 is a multifunctional protein participating, among others, in gene transcription and mRNA metabolism. SND1 is overexpressed in cancer cells and promotes viability and tumourigenicity of hepatocellular carcinoma cells. This study shows that cholesterol synthesis is increased in SND1-overexpressing hepatoma cells. Neither newly synthesised nor extracellularly supplied cholesterol are able to suppress this increase; however, inhibition of cholesterol esterification reverted the activated state of sterol-regulatory element-binding protein 2 (SREBP2) and cholesterogenesis. These results highlight SND1 as a potential regulator of cellular cholesterol distribution and homeostasis in hepatoma cells, and support the rationale for the therapeutic use of molecules that influence cholesterol management when SND1 is overexpressed. PMID:27238764

  19. Helicobacter pylori's cholesterol uptake impacts resistance to docosahexaenoic acid.

    Science.gov (United States)

    Correia, Marta; Casal, Susana; Vinagre, João; Seruca, Raquel; Figueiredo, Ceu; Touati, Eliette; Machado, José C

    2014-05-01

    Helicobacter pylori colonizes half of the world population and is associated with gastric cancer. We have previously demonstrated that docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid known for its anti-inflammatory and antitumor effects, directly inhibits H. pylori growth in vitro and in mice. Nevertheless, the concentration of DHA shown to reduce H. pylori mice gastric colonization was ineffective in vitro. Related to the auxotrophy of H. pylori for cholesterol, we hypothesize that other mechanisms, in addition to DHA direct antibacterial effect, must be responsible for the reduction of the infection burden. In the present study we investigated if DHA affects also H. pylori growth, by reducing the availability of membrane cholesterol in the epithelial cell for H. pylori uptake. Levels of cholesterol in gastric epithelial cells and of cholesteryl glucosides in H. pylori were determined by thin layer chromatography and gas chromatography. The consequences of epithelial cells' cholesterol depletion on H. pylori growth were assessed in liquid cultures. We show that H. pylori uptakes cholesterol from epithelial cells. In addition, DHA lowers cholesterol levels in epithelial cells, decreases its de novo synthesis, leading to a lower synthesis of cholesteryl glucosides by H. pylori. A previous exposition of H. pylori to cholesterol influences the bacterium response to the direct inhibitory effect of DHA. Overall, our results suggest that a direct effect of DHA on H. pylori survival is modulated by its access to epithelial cell cholesterol, supporting the notion that cholesterol enhances the resistance of H. pylori. The cholesterol-dependent resistance of H. pylori to antimicrobial compounds raises new important aspects for the development of new anti-bacterial strategies. PMID:24447914

  20. Bacterial colonization of host cells in the absence of cholesterol.

    Directory of Open Access Journals (Sweden)

    Stacey D Gilk

    2013-01-01

    Full Text Available Reports implicating important roles for cholesterol and cholesterol-rich lipid rafts in host-pathogen interactions have largely employed sterol sequestering agents and biosynthesis inhibitors. Because the pleiotropic effects of these compounds can complicate experimental interpretation, we developed a new model system to investigate cholesterol requirements in pathogen infection utilizing DHCR24(-/- mouse embryonic fibroblasts (MEFs. DHCR24(-/- MEFs lack the Δ24 sterol reductase required for the final enzymatic step in cholesterol biosynthesis, and consequently accumulate desmosterol into cellular membranes. Defective lipid raft function by DHCR24(-/- MEFs adapted to growth in cholesterol-free medium was confirmed by showing deficient uptake of cholera-toxin B and impaired signaling by epidermal growth factor. Infection in the absence of cholesterol was then investigated for three intracellular bacterial pathogens: Coxiella burnetii, Salmonella enterica serovar Typhimurium, and Chlamydia trachomatis. Invasion by S. Typhimurium and C. trachomatis was unaltered in DHCR24(-/- MEFs. In contrast, C. burnetii entry was significantly decreased in -cholesterol MEFs, and also in +cholesterol MEFs when lipid raft-associated α(Vβ(3 integrin was blocked, suggesting a role for lipid rafts in C. burnetii uptake. Once internalized, all three pathogens established their respective vacuolar niches and replicated normally. However, the C. burnetii-occupied vacuole within DHCR24(-/- MEFs lacked the CD63-positive material and multilamellar membranes typical of vacuoles formed in wild type cells, indicating cholesterol functions in trafficking of multivesicular bodies to the pathogen vacuole. These data demonstrate that cholesterol is not essential for invasion and intracellular replication by S. Typhimurium and C. trachomatis, but plays a role in C. burnetii-host cell interactions.

  1. Atorvastatin increases HDL cholesterol by reducing CETP expression in cholesterol-fed APOE*3-Leiden.CETP mice

    NARCIS (Netherlands)

    Haan, W. de; Hoogt, C.C. van der; Westerterp, M.; Hoekstra, M.; Dallinga-Thie, G.M.; Princen, H.M.G.; Romijn, J.A.; Jukema, J.W.; Havekes, L.M.; Rensen, P.C.N.

    2008-01-01

    Objective: In addition to lowering low-density lipoprotein (LDL)-cholesterol, statins modestly increase high-density lipoprotein (HDL)-cholesterol in humans and decrease cholesteryl ester transfer protein (CETP) mass and activity. Our aim was to determine whether the increase in HDL depends on CETP

  2. Function of MRP1/ABCC1 is not dependent on cholesterol or cholesterol-stabilized lipid rafts

    NARCIS (Netherlands)

    Meszaros, Peter; Klappe, Karin; Hummel, Ina; Hoekstra, Dick; Kok, Jan Willem

    2011-01-01

    MRP1 (multidrug-resistance-related protein 1)/ABCC1 (ATP-binding cassette transporter C1) has been localized in cholesterol-enriched lipid rafts, which suggests a role for these lipid rafts and/or cholesterol in MRP1 function. In the present study, we have shown for the first time that nearly comple

  3. A cholesterol-free, high-fat diet suppresses gene expression of cholesterol transporters in murine small intestine

    NARCIS (Netherlands)

    den Bosch, Heleen M. de Vogel-van; de Wit, Nicole J. W.; Hooiveld, Guido J. E. J.; Vermeulen, Hanneke; van der Veen, Jelske N.; Houten, Sander M.; Kuipers, Folkert; Mueller, Michael; van der Meer, Roelof

    2008-01-01

    A cholesterol-free, high-fat diet suppresses gene expression of cholesterol transporters in murine small intestine. Am J Physiol Gastrointest Liver Physiol 294: G1171-G1180, 2008. First published March 20, 2008; doi:10.1152/ajpgi.00360.2007.-Transporters present in the epithelium of the small intest

  4. How cholesterol interacts with membrane proteins: an exploration of cholesterol-binding sites including CRAC, CARC and tilted domains

    Directory of Open Access Journals (Sweden)

    Jacques eFantini

    2013-02-01

    Full Text Available The plasma membrane of eukaryotic cells contains several types of lipids displaying high biochemical variability in both their apolar moiety (e.g. the acyl chain of glycerolipids and their polar head (e.g. the sugar structure of glycosphingolipids. Among these lipids, cholesterol is unique because its biochemical variability is almost exclusively restricted to the oxidation of its polar -OH group. Although generally considered the most rigid membrane lipid, cholesterol can adopt a broad range of conformations due to the flexibility of its isooctyl chain linked to the polycyclic sterane backbone. Moreover, cholesterol is an asymmetric molecule displaying a planar face and a rough  face. Overall, these structural features open up a number of possible interactions between cholesterol and membrane lipids and proteins, consistent with the prominent regulatory functions that this unique lipid exerts on membrane components. The aim of this review is to describe how cholesterol interacts with membrane lipids and proteins at the molecular/atomic scale, with special emphasis on transmembrane domains of proteins containing either the consensus cholesterol-binding motifs CRAC and CARC or a tilted peptide. Despite their broad structural diversity, all these domains bind cholesterol through common molecular mechanisms, leading to the identification of a subset of amino acid residues that are overrepresented in both linear and three-dimensional membrane cholesterol-binding sites.

  5. The influence of cholesterol and biomass concentration on the uptake of cholesterol by Lactobacillus from MRS broth

    Directory of Open Access Journals (Sweden)

    Małgorzata Ziarno

    2007-06-01

    Full Text Available The aim of this study was the determination of some factors influence (i.e. the vitality of bacteria cells and the cholesterol concentration on the ability of selected Lactobacillus sp. to cholesterol uptake during culture in MRS broth. Three Lactobacillus strains (Lb. delbrueckii subsp. bulgaricus, Lb. acidophilus, Lb. casei isolated from commercial single species lyophilized dairy starter cultures and three Lactobacillus strains (Lb. plantarum, Lb. delbrueckii subsp. bulgaricus, Lb. acidophilus originated from commercial pharmaceuticals were used in this study. The uptake of cholesterol from MRS broth during the growth of Lactobacillus sp., expressed as the difference between the final and the initial concentrations of cholesterol, ranged from 0.053 to 0.153 g/dm³, apart from the initial cholesterol content and the origin of Lactobacillus sp. The results confirmed that biomass concentration have a statistically significant effect on uptake of cholesterol. The ten-fold increase of the amount of intact cells biomass caused about 1.5-2-fold increase of the amount of cholesterol removed. The influence of the concentration of biomass of alive cells on the removal of cholesterol was bigger than in case of the heat-sterilized cells.

  6. Regulation of reverse cholesterol transport - a comprehensive appraisal of available animal studies

    NARCIS (Netherlands)

    Annema, Wijtske; Tietge, Uwe J. F.

    2012-01-01

    Plasma levels of high density lipoprotein (HDL) cholesterol are strongly inversely correlated to the risk of atherosclerotic cardiovascular disease. A major recognized functional property of HDL particles is to elicit cholesterol efflux and consequently mediate reverse cholesterol transport (RCT). T

  7. Dose effects of dietary phytosterols on cholesterol metabolism: a controlled feeding study123

    OpenAIRE

    Racette, Susan B.; Lin, Xiaobo; Lefevre, Michael; Spearie, Catherine Anderson; MOST, MARLENE M.; Ma, Lina; Ostlund, Richard E

    2009-01-01

    Background: Phytosterol supplementation of 2 g/d is recommended by the National Cholesterol Education Program to reduce LDL cholesterol. However, the effects of different intakes of phytosterol on cholesterol metabolism are uncertain.

  8. High Blood Cholesterol Q&A Dr. Michael Lauer | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... this page please turn Javascript on. Feature: High Cholesterol High Blood Cholesterol Q&A with Dr. Michael Lauer Past Issues / ... heavier and older, what does recent research on cholesterol and heart health tell us that Americans need ...

  9. LCAT, HDL Cholesterol and Ischemic Cardiovascular Disease: A Mendelian Randomization Study of HDL Cholesterol in 54,500 Individuals

    DEFF Research Database (Denmark)

    Haase, Christiane L; Tybjærg-Hansen, Anne; Ali Qayyum, Abbas;

    2012-01-01

    Background:Epidemiologically, high-density lipoprotein (HDL) cholesterol levels associate inversely with risk of ischemic cardiovascular disease. Whether this is a causal relation is unclear.Methods:We studied 10,281 participants in the Copenhagen City Heart Study (CCHS) and 50,523 participants...... in the Copenhagen General Population Study (CGPS), of which 991 and 1,693 participants, respectively, had developed myocardial infarction (MI) by August 2010. Participants in the CCHS were genotyped for all six variants identified by resequencing lecithin-cholesterol acyltransferase in 380 individuals. One variant......, S208T (rs4986970, allele frequency 4%), associated with HDL cholesterol levels in both the CCHS and the CGPS was used to study causality of HDL cholesterol using instrumental variable analysis.Results:Epidemiologically, in the CCHS, a 13% (0.21 mmol/liter) decrease in plasma HDL cholesterol levels...

  10. Toxin a from Clostridium difficile binds to rabbit erythrocyte glycolipids with therminal Galα1-3Galβ1-4GlcNaC sequences

    International Nuclear Information System (INIS)

    Toxin A is one of two clostridial toxins implicated as the causative agent of pseudomembranous colitis in patients undergoing postoperative antibiotic therapy. Evidence that the carbohydrate binding determinant for this toxin is a glycoconjugate(s) with non-reducing Galα1-3Galβ1-4GlcNAc has recently been reported. Specific agglutination of rabbit erythrocytes by Toxin A is inhibited by bovine thyroglobulin and prevented by pretreatment of cells with α-galactosidase. Total lipid extracts from rabbit erythrocytes were subjected to thin layer chromatography and the chromatogram overlaid with purified 125I-labeled Toxin A. Two major and several minor toxin-binding glycolipids were detected following autoradiography. The major toxin-binding glycolipids were identified as pentasaccharide- and decasaccharide-ceramides expressing terminal Galα1-3Galβ1-4GlcNAc sequences. Treatment of the toxin-binding glycolipids with α-galactosidase abolished binding. Forsmann glycolipid, globoside, Galα1-4 Galβ1-4Glc-cer, and Galα1-3Galβ1-4Glc-cer did not bind the toxin. These observations are consistent with the proposed carbohydrate specificity of the toxin for the non-reducing terminal sequence, Galα1-3Galβ1-4GlcNAc

  11. Serum albumin acts as a shuttle to enhance cholesterol efflux from cells[S

    OpenAIRE

    Sankaranarayanan, Sandhya; de la Llera-Moya, Margarita; Drazul-Schrader, Denise; Phillips, Michael C.; Kellner-Weibel, Ginny; Rothblat, George H.

    2013-01-01

    An important mechanism contributing to cell cholesterol efflux is aqueous transfer in which cholesterol diffuses from cells into the aqueous phase and becomes incorporated into an acceptor particle. Some compounds can enhance diffusion by acting as shuttles transferring cholesterol to cholesterol acceptors, which act as cholesterol sinks. We have examined whether particles in serum can enhance cholesterol efflux by acting as shuttles. This task was accomplished by incubating radiolabeled J774...

  12. Cholesterol organization in membranes at low concentrations: effects of curvature stress and membrane thickness.

    OpenAIRE

    Rukmini, R; Rawat, S S; Biswas, S. C.; Chattopadhyay, A

    2001-01-01

    Cholesterol is often found distributed nonrandomly in domains in biological and model membranes and has been reported to be distributed heterogeneously among various intracellular membranes. Although a large body of literature exists on the organization of cholesterol in plasma membranes or membranes with high cholesterol content, very little is known about organization of cholesterol in membranes containing low amounts of cholesterol. Using a fluorescent cholesterol analog (25-[N-[(7-nitrobe...

  13. Constraining Ceres' interior from its Rotational Motion

    CERN Document Server

    Rambaux, Nicolas; Dehant, Véronique; Kuchynka, Petr

    2011-01-01

    Context. Ceres is the most massive body of the asteroid belt and contains about 25 wt.% (weight percent) of water. Understanding its thermal evolution and assessing its current state are major goals of the Dawn Mission. Constraints on internal structure can be inferred from various observations. Especially, detailed knowledge of the rotational motion can help constrain the mass distribution inside the body, which in turn can lead to information on its geophysical history. Aims. We investigate the signature of the interior on the rotational motion of Ceres and discuss possible future measurements performed by the spacecraft Dawn that will help to constrain Ceres' internal structure. Methods. We compute the polar motion, precession-nutation, and length-of-day variations. We estimate the amplitudes of the rigid and non-rigid response for these various motions for models of Ceres interior constrained by recent shape data and surface properties. Results. As a general result, the amplitudes of oscillations in the r...

  14. Continuation of Sets of Constrained Orbit Segments

    DEFF Research Database (Denmark)

    Schilder, Frank; Brøns, Morten; Chamoun, George Chaouki;

    Sets of constrained orbit segments of time continuous flows are collections of trajectories that represent a whole or parts of an invariant set. A non-trivial but simple example is a homoclinic orbit. A typical representation of this set consists of an equilibrium point of the flow and a trajectory...... that starts close and returns close to this fixed point within finite time. More complicated examples are hybrid periodic orbits of piecewise smooth systems or quasi-periodic invariant tori. Even though it is possible to define generalised two-point boundary value problems for computing sets of...... constrained orbit segments, this is very disadvantageous in practice. In this talk we will present an algorithm that allows the efficient continuation of sets of constrained orbit segments together with the solution of the full variational problem....

  15. Towards weakly constrained double field theory

    Science.gov (United States)

    Lee, Kanghoon

    2016-08-01

    We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon) transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

  16. Towards weakly constrained double field theory

    Directory of Open Access Journals (Sweden)

    Kanghoon Lee

    2016-08-01

    Full Text Available We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

  17. Towards Weakly Constrained Double Field Theory

    CERN Document Server

    Lee, Kanghoon

    2015-01-01

    We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon) transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X- ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

  18. Resveratrol Protects Rabbits Against Cholesterol Diet-Induced Hyperlipidaemia.

    Science.gov (United States)

    Tanko, Y; Jimoh, A; Ahmed, A; Mohammed, A; Ayo, J O

    2016-01-01

    The excessive consumption of high cholesterol diet has been associated with an increased incidence oflipidaemia. Lipidaemia is enhanced by formation of oxidative stress, lipid peroxidation and hyperglycaemia. The aim ofthese experiments was to investigate the protective effect of resveratrol co-administered with cholesterol diet inducedhyperlipidaemia in rabbits. Thirty rabbits divided into six groups of five animal (group= 5) each: group 1 = normal control,group 2 = cholesterol diet/high fat diet group only (HFD), group 3 = resveratrol 200 mg/kg (R200), group 4 = resveratrol400 mg/kg (R400), group 5 = HFD + R200 and group 6 = HFD + R400. The normal group was fed with standard animalfeeds only; while the HFD groups were fed with standard animal feeds + cholesterol diet (10% Groundnut oil, 20%Groundnut mill and 2% cholesterol). Resveratrol-treated rabbits received resveratrol suspended in 10 g/Lcarboxymethylcellulose (CMC) and the control group received the vehicle only, CMC. The preparations were administeredfor 8 weeks of experimental protocol. At the end of the study period, the animals were sacrificed. Blood and plasma sampleswere collected. Serum evaluation of lipid profile such as total cholesterol (TC), triacylglycerol (Tg), low density lipoproteincholesterol (LDP-c) and high density lipoprotein cholesterol (HDL-c) were also assessed. The results obtained showsignificant (P resveratrol treated groups compared to HFD group only.In conclusion, the findings indicated that Resveratrol may contain polar products able to lower plasma lipid concentrationsand might be beneficial in treatment of hyperlipidemia and atherosclerosis. PMID:27574767

  19. CHOLESTEROL LEVELS AND SUICIDAL BEHAVIOR: A CASE CONTROL STUDY

    Directory of Open Access Journals (Sweden)

    Nikhil

    2014-06-01

    Full Text Available BACKGROUND: In modern psychiatry, there is a movement to understand mental health, not solely based on behaviors and subjective report, but also based on objective markers of illness. Several studies have focused on a relationship between serum cholesterol levels and aggressive behaviors including suicide. AIM: To identify a potential link between cholesterol and suicidal behavior. MATERIAL AND METHODS: 150 patients with psychiatry diagnosis were divided into three equal groups (50 each: those who had a recent suicidal attempt, those who had suicidal ideations but no attempts and those with psychiatry diagnosis but no suicidal ideations and attempts. Blood sample for total cholesterol level was on IPD or OPD basis. The study was started after taking approval from institute ethical committee. Analysis was done using Chi square test. OBSERVATIONS AND RESULTS: It was found that maximum patients who attempted suicide belonged to major depression and schizophrenia followed by substance dependence and bipolar affective disorder (BPAD with major depression and there was statistical difference in cholesterol levels of patients with suicide attempt, with suicidal ideations and control group. 42% and 44% of major depression and schizophrenia cases respectively had low total serum cholesterol levels (below 160 mg%. CONCLUSION: There is a potential link between serum total cholesterol levels and suicidal behavior. Taking the literature as a whole there is substantial evidence that low cholesterol levels are found in suicidal behaviors of various psychiatric illnesses especially major depressive disorder, schizophrenia, substance dependence and bipolar depressive disorder

  20. Effect of insulin and metformin on methylation and glycolipid metabolism of peroxisome proliferator-activated receptor γcoactivator-1A of rat offspring with gestational diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    Ai-Qin Song; Li-Rong Sun; Yan-Xia Zhao; Yan-Hua Gao; Lei Chen

    2016-01-01

    Objective: To discuss the effect of insulin and metformin on amethylation and glycolipid metabolism of peroxisome proliferator-activated receptor γ coactivator-1A (PPARGC1A) ofrat offspring with gestational diabetes mellitus (GDM). Methods: A total of 45 pregnant rats received the intraperitoneal injection of streptozotocin to establish the pregnant rat model of GDM. A total of 21 pregnant rats with GDM were randomly divided into three groups, with 7 rats in each group, namely the insulin group, metformin group and control group. Rats in the insulin group received the abdominal subcutaneous injection of 1 mL/kg recombinant insulin glargine at 18: 00 every day. Rats in the metformin group received the intragastric infusion of metformin hydrochloride at 18: 00 every day, with the first dose of 300 mg/kg. The doses of two groups were adjusted every 3 d to maintain the blood glucose level at 2.65-7.62 mmol/L. Rats in the control group received the intragastric infusion of 1 mL normal saline at 18:00 every day. After the natural delivery of pregnant rats, 10 offspring rats were randomly selected from each group. At birth, 4 wk and 8 wk after the birth of offspring rats, the weight of offspring rats was measured. The blood glucose level of offspring rats was measured at 4 wk and 8 wk, while the level of serum insulin, triglyceride and leptin was measured at 8 wk.Results: The weight of offspring rats at birth in the insulin group and metformin group was significantly lower than the one in the control group (P0.05). The fasting blood glucose and random blood glucose in the insulin group and metformin group at 4 wk and 8 wk were all significantly lower than ones in the control group (P0.05). The expression of PPARGC1A mRNA in the insulin group and metformin group was significantly higher and the methylation level of PPARGC1A was significantly lower than the one in the control group (P0.05). Insulin and leptin at 8 wk in the insulin group and metformin group were

  1. Constraining Initial Vacuum by CMB Data

    CERN Document Server

    Chandra, Debabrata

    2016-01-01

    We demonstrate how one can possibly constrain the initial vacuum using CMB data. Using a generic vacuum without any particular choice a priori, thereby keeping both the Bogolyubov coefficients in the analysis, we compute observable parameters from two- and three-point correlation functions. We are thus left with constraining four model parameters from the two complex Bogolyubov coefficients. We also demonstrate a method of finding out the constraint relations between the Bogolyubov coefficients using the theoretical normalization condition and observational data of power spectrum and bispectrum from CMB. We also discuss the possible pros and cons of the analysis.

  2. Constrained instanton and black hole creation

    Institute of Scientific and Technical Information of China (English)

    WU; Zhongchao; XU; Donghui

    2004-01-01

    A gravitational instanton is considered as the seed for the creation of a universe. However, there exist too few instantons. To include many interesting phenomena in the framework of quantum cosmology, the concept of constrained gravitational instanton is inevitable. In this paper we show how a primordial black hole is created from a constrained instanton. The quantum creation of a generic black hole in the closed or open background is completely resolved. The relation of the creation scenario with gravitational thermodynamics and topology is discussed.

  3. Library Support for Resource Constrained Accelerators

    DEFF Research Database (Denmark)

    Brock-Nannestad, Laust; Karlsson, Sven

    2014-01-01

    Accelerators, and other resource constrained systems, are increasingly being used in computer systems. Accelerators provide power efficient performance and often provide a shared memory model. However, it is a challenge to map feature rich APIs, such as OpenMP, to resource constrained systems....... In this paper, we present a lightweight system where an accelerator can remotely execute library functions on a host processor. The implementation takes up 750 bytes but can replace arbitrary library calls leading to significant savings in memory foot print. We evaluate with a set of SPLASH-2 applications...

  4. Cholesterol induces fetal rat enterocyte death in culture

    Directory of Open Access Journals (Sweden)

    Gazzola J.

    2004-01-01

    Full Text Available The effect of cholesterol on fetal rat enterocytes and IEC-6 cells (line originated from normal rat small intestine was examined. Both cells were cultured in the presence of 20 to 80 µM cholesterol for up to 72 h. Apoptosis was determined by flow cytometric analysis and fluorescence microscopy. The expression of HMG-CoA reductase and peroxisome proliferator-activated receptor gamma (PPARgamma was measured by RT-PCR. The addition of 20 µM cholesterol reduced enterocyte proliferation as early as 6 h of culture. Reduction of enterocyte proliferation by 28 and 41% was observed after 24 h of culture in the presence and absence of 10% fetal calf serum, respectively, with the effect lasting up to 72 h. Treatment of IEC-6 cells with cholesterol for 24 h raised the proportion of cells with fragmented DNA by 9.7% at 40 µM and by 20.8% at 80 µM. When the culture period was extended to 48 h, the effect of cholesterol was still more pronounced, with the percent of cells with fragmented DNA reaching 53.5% for 40 µM and 84.3% for 80 µM. Chromatin condensation of IEC-6 cells was observed after treatment with cholesterol even at 20 µM. Cholesterol did not affect HMG-CoA reductase expression. A dose-dependent increase in PPARgamma expression in fetal rat enterocytes was observed. The expression of PPAR-gamma was raised by 7- and 40-fold, in the presence and absence of fetal calf serum, respectively, with cholesterol at 80 mM. The apoptotic effect of cholesterol on enterocytes was possibly due to an increase in PPARgamma expression.

  5. Low HDL cholesterol, aggression and altered central serotonergic activity.

    Science.gov (United States)

    Buydens-Branchey, L; Branchey, M; Hudson, J; Fergeson, P

    2000-03-01

    Many studies support a significant relation between low cholesterol levels and poor impulse, aggression and mood control. Evidence exists also for a causal link between low brain serotonin (5-HT) activity and these behaviors. Mechanisms linking cholesterol and hostile or self-destructive behavior are unknown, but it has been suggested that low cholesterol influences 5-HT function. This study was designed to explore the relationship between plasma cholesterol, measures of impulsivity and aggression, and indices of 5-HT function in personality disordered cocaine addicts. Thirty-eight hospitalized male patients (age 36.8+/-7.1) were assessed with the DSM-III-R, the Buss-Durkee Hostility Inventory (BDHI), the Barratt Impulsiveness Scale (BIS) and the Brown-Goodwin Assessment for Life History of Aggression. Fasting basal cholesterol (total, LDL and HDL) was determined 2 weeks after cocaine discontinuation. On the same day 5-HT function was assessed by neuroendocrine (cortisol and prolactin) and psychological (NIMH and 'high' self-rating scales) responses following meta-chlorophenylpiperazine (m-CPP) challenges. Reduced neuroendocrine responses, 'high' feelings and increased 'activation-euphoria' following m-CPP have been interpreted as indicating 5-HT alterations in a variety of psychiatric conditions. Significantly lower levels of HDL cholesterol were found in patients who had a history of aggression (P=0.005). Lower levels of HDL cholesterol were also found to be significantly associated with more intense 'high' and 'activation-euphoria' responses as well as with blunted cortisol responses to m-CPP (P=0.033, P=0.025 and P=0.018, respectively). This study gives further support to existing evidence indicating that in some individuals, the probability of exhibiting impulsive and violent behaviors may be increased when cholesterol is low. It also suggests that low cholesterol and alterations in 5-HT activity may be causally related.

  6. Statins: Cholesterol guidelines and Indian perspective

    Directory of Open Access Journals (Sweden)

    Anil S Menon

    2015-01-01

    Full Text Available Statins have become an important drug in preventing the occurrence of atherosclerotic cardiovascular disease (ASCVD. The effectiveness of statins in reducing ASCVD has been established in large-scale clinical trials. The lipid management guidelines have been periodically modified due to accumulating evidence about the proportionate benefit achieved with a progressive reduction in cholesterol levels with higher doses of statins and even in those at low risk of development of ASCVD. The current American College of Cardiology/American Heart Association guidelines have based its recommendations from data gathered exclusively from randomized controlled trials. It has simplified the use of statins, but also raised questions regarding the validity of its cardiovascular event risk prediction tool. Epidemiology of cardiovascular disease in India differs from the western population; there is an increased the prevalence of metabolic syndrome and atherogenic dyslipidemia phenotype a group not addressed in the current guidelines. The guidelines are based on trials, which do not have a representative South Asian population. This article reviews the relevant literature, and examines the issues involved in adopting the guidelines to the Indian population.

  7. Does fat in milk, butter and and cholesterol differently?

    DEFF Research Database (Denmark)

    Tholstrup, T,; Høy, Carl-Erik; Andersen, L.N.;

    2004-01-01

    and 8 hours following intake of the meals. Results: Fasting LDL cholesterol concentration was significantly higher after butter than cheese diet (p 0.037), with a borderline significant difference in total cholesterol (p = 0.054) after the experimental periods of three weeks. Postprandial glucose showed...... a higher response after cheese diet than after milk diet (p = 0.010, diet X time interaction). Conclusions: A different effect of fat in milk and butter could not be confirmed in this study. The moderately lower LDL cholesterol after cheese diet compared to butter diet should be investigated further....

  8. Reverse cholesterol transport: From classical view to new insights

    Institute of Scientific and Technical Information of China (English)

    Astrid; E; van; der; Velde

    2010-01-01

    Cholesterol is of vital importance for the human body. It is a constituent for most biological membranes, it is needed for the formation of bile salts, and it is the pre- cursor for steroid hormones and vitamin D. However, the presence of excess cholesterol in cells, and in particular in macrophages in the arterial vessel wall, might be harmful. The accumulation of cholesterol in arteries can lead to atherosclerosis, and in turn, to other cardiovascular diseases. The route that is primarily thought to be re...

  9. Assessing Cholesterol Storage in Live Cells and C. elegans by Stimulated Raman Scattering Imaging of Phenyl-Diyne Cholesterol

    Science.gov (United States)

    Lee, Hyeon Jeong; Zhang, Wandi; Zhang, Delong; Yang, Yang; Liu, Bin; Barker, Eric L.; Buhman, Kimberly K.; Slipchenko, Lyudmila V.; Dai, Mingji; Cheng, Ji-Xin

    2015-01-01

    We report a cholesterol imaging method using rationally synthesized phenyl-diyne cholesterol (PhDY-Chol) and stimulated Raman scattering (SRS) microscope. The phenyl-diyne group is biologically inert and provides a Raman scattering cross section that is 88 times larger than the endogenous C = O stretching mode. SRS microscopy offers an imaging speed that is faster than spontaneous Raman microscopy by three orders of magnitude, and a detection sensitivity of 31 μM PhDY-Chol (~1,800 molecules in the excitation volume). Inside living CHO cells, PhDY-Chol mimics the behavior of cholesterol, including membrane incorporation and esterification. In a cellular model of Niemann-Pick type C disease, PhDY-Chol reflects the lysosomal accumulation of cholesterol, and shows relocation to lipid droplets after HPβCD treatment. In live C. elegans, PhDY-Chol mimics cholesterol uptake by intestinal cells and reflects cholesterol storage. Together, our work demonstrates an enabling platform for study of cholesterol storage and trafficking in living cells and vital organisms.

  10. Comparison of biosensors based on entrapment of cholesterol oxidase and cholesterol esterase in electropolymerized films of polypyrrole and diaminonaphthalene derivatives for amperometric determination of cholesterol.

    Science.gov (United States)

    Vidal, J C; Garcia-Ruiz, E; Espuelas, J; Aramendia, T; Castillo, J R

    2003-09-01

    Cholesterol amperometric biosensors constructed with enzymes entrapped in electropolymerized layers of polypyrrole and poly-naphthalene derivative polymers are compared. The biosensors are based on entrapment of cholesterol oxidase and/or cholesterol esterase in monolayer or multilayer films electrochemically synthesised from pyrrole, 1,8-diaminonaphthalene (1,8-DAN), and 1,5-diaminonaphthalene (1,5-DAN) monomers. Seven configurations were assayed and compared, and different analytical properties were obtained depending on the kind of polymer and the arrangement of the layers. The selectivity properties were evaluated for the different monolayer and bilayer configurations proposed as a function of the film permeation factor. All the steps involved in the preparation of the biosensors and determination of cholesterol were carried out in a flow system. Sensitivity and selectivity depend greatly on hydrophobicity, permeability, compactness, thickness, and the kind of the polymer used. In some cases a protective outer layer of non-conducting poly( o-phenylenediamine) polymer improves the analytical characteristics of the biosensor. A comparative study was made of the analytical performance of each of the configurations developed. The biosensors were also applied to the flow-injection determination of cholesterol in a synthetic serum. PMID:12923606

  11. General Relativity as a constrained Gauge Theory

    OpenAIRE

    Cianci, R.; Vignolo, S.; Bruno, D

    2006-01-01

    The formulation of General Relativity presented in math-ph/0506077 and the Hamiltonian formulation of Gauge theories described in math-ph/0507001 are made to interact. The resulting scheme allows to see General Relativity as a constrained Gauge theory.

  12. Neutron Powder Diffraction and Constrained Refinement

    DEFF Research Database (Denmark)

    Pawley, G. S.; Mackenzie, Gordon A.; Dietrich, O. W.

    1977-01-01

    The first use of a new program, EDINP, is reported. This program allows the constrained refinement of molecules in a crystal structure with neutron diffraction powder data. The structures of p-C6F4Br2 and p-C6F4I2 are determined by packing considerations and then refined with EDINP. Refinement...

  13. PRICING AND HEDGING OPTION UNDER PORTFOLIO CONSTRAINED

    Institute of Scientific and Technical Information of China (English)

    魏刚; 陈世平

    2001-01-01

    The authors employ convex analysis and stochastic control approach to study the question of hedging contingent claims with portfolio constrained to take values in a given closed, convex subset of RK, and extend the results of Gianmario Tessitore and Jerzy Zabczyk[6] on pricing options in multiasset and multinominal model.

  14. Constrained Optimization in Simulation : A Novel Approach

    NARCIS (Netherlands)

    Kleijnen, J.P.C.; van Beers, W.C.M.; van Nieuwenhuyse, I.

    2008-01-01

    This paper presents a novel heuristic for constrained optimization of random computer simulation models, in which one of the simulation outputs is selected as the objective to be minimized while the other outputs need to satisfy prespeci¯ed target values. Besides the simulation outputs, the simulati

  15. Nonlinear wave equations and constrained harmonic motion

    OpenAIRE

    Deift, Percy; Lund, Fernando; Trubowitz, Eugene

    1980-01-01

    The study of the Korteweg-deVries, nonlinear Schrödinger, Sine-Gordon, and Toda lattice equations is simply the study of constrained oscillators. This is likely to be true for any nonlinear wave equation associated with a second-order linear problem.

  16. Serological tests in leprosy. The sensitivity, specificity and predictive value of ELISA tests based on phenolic glycolipid antigens, and the implications for their use in epidemiological studies.

    Science.gov (United States)

    Burgess, P J; Fine, P E; Ponnighaus, J M; Draper, C

    1988-08-01

    This paper examines the sensitivity and specificity of two ELISA assays for IgM antibodies to Mycobacterium leprae, one employing natural phenolic glycolipid and the other employing a synthetic disaccharide glycoconjugate as antigen. Estimates of sensitivity and specificity are derived, based on a panel of sera from leprosy cases in Malawi and various non-leprosy controls from the UK. Though both assays were able to identify a high proportion of multibacillary patients, neither was able to detect a high proportion of paucibacillary patients without considerable loss of specificity. The implications of the inverse relationship between sensitivity and specificity are discussed with reference to the predictive value of such tests in such areas as Malawi, where the large majority of cases are paucibacillary.

  17. Structure-function analysis of the ATP-driven glycolipid efflux pump DevBCA reveals complex organization with TolC/HgdD.

    Science.gov (United States)

    Staron, Peter; Forchhammer, Karl; Maldener, Iris

    2014-01-31

    In Gram-negative bacteria, trans-envelope efflux pumps have periplasmic membrane fusion proteins (MFPs) as essential components. MFPs act as mediators between outer membrane factors (OMFs) and inner membrane factors (IMFs). In this study, structure-function relations of the ATP-driven glycolipid efflux pump DevBCA-TolC/HgdD from the cyanobacterium Anabaena sp. PCC 7120 were analyzed. The binding of the MFP DevB to the OMF TolC absolutely required the respective tip-regions. The interaction of DevB with the IMF DevAC mainly involved the β-barrel and the lipoyl domain. Efficient binding to DevAC and TolC, substrate recognition and export activity by DevAC were dependent on stable DevB hexamers. PMID:24361095

  18. Structural characterization and surface-active properties of a new glycolipid biosurfactant, mono-acylated mannosylerythritol lipid, produced from glucose by Pseudozyma antarctica.

    Science.gov (United States)

    Fukuoka, Tokuma; Morita, Tomotake; Konishi, Masaaki; Imura, Tomohiro; Sakai, Hideki; Kitamoto, Dai

    2007-09-01

    Mannosylerythritol lipids (MELs), which are glycolipid biosurfactants produced by Pseudozyma yeasts, show not only excellent interfacial properties but also versatile biochemical actions. In the course of MEL production from glucose as the sole carbon source, P. antarctica was found to produce unknown glycolipids more hydrophilic than conventional "di-acylated MELs," which have two fatty acyl esters on the mannose moiety. Based on a detailed characterization, the most hydrophilic one was identified as 4-O-(3'-O-alka(e)noyl-beta-D: -mannopyranosyl)-D: -erythritol namely, "mono-acylated MEL." The mono-acylated MEL reduced the surface tension of water to 33.8 mN/m at a critical micelle concentration (CMC) of 3.6 x 10(-4) M, and its hydrophilic-lipophilic balance was tentatively calculated to be 12.15. The observed CMC was 100-fold higher than that of the MELs hitherto reported. Interestingly, of the yeast strains of the genus Pseudozyma, only P. antarctica and P. parantarctica gave the mono-acylated MEL from glucose, despite a great diversity of di-acylated MEL producers in the genus. These strains produced MELs including the mono-acylated one at a rate of 20-25%. From these results, the new MEL is likely to have great potential for use in oil-in-water-type emulsifiers and washing detergents because of its higher water solubility compared to conventional MELs and will thus contribute to facilitating a broad range of applications for the environmentally advanced surfactants. PMID:17607573

  19. Three cases of cholesterol granuloma in the mandible

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Min Jung; Huh, Kyung Hoe; Yi, Won Jin; Moon, Je Woon; Choi, Soon Chul [Seoul National Univ. School of Dentitry, Seoul (Korea, Republic of); Shin, Jae Myung [Inje Univ. College of Medicine, Kimhae (Korea, Republic of)

    2007-12-15

    Cholesterol granuloma is an unusual clinical entity described as an inflammatory granulation in response to the deposit of cholesterol crystals. It can develop in any portion of air cells within the temporal bone as a result of a lack of aeration and inadequate drainage, especially in the middle ear cavity. Here, we report very unusual three cases of cholesterol granuloma developed in mandible. In the first case a 68-year-old male with a large mass arising from the mandible was observed. Panoramic radiograph and computed tomography scans revealed a huge expanding lesion in the mandible. In the second case a 47-years-old female with a cystic lesion in the mandible was observed. And in the third case a 19-year-old male complaining atypical facial pain had a large lesion in the mandibular ramous. The histopathologic examinations of the cases showed numerous cholesterol crystal surrounded by multinucleated foreign body giant cells.

  20. Preterm delivery and low maternal serum cholesterol level: any correlation?

    Directory of Open Access Journals (Sweden)

    Ayodeji A. Oluwole

    2014-04-01

    Results: The study showed an incidence of 5.0% for preterm delivery in the low risk study patients. Preterm birth was 4.83-times more common with low total maternal cholesterol than with midrange total cholesterol (11.8% versus 2.2%, P = 0.024. Conclusions: We can infer from the study that the low maternal serum cholesterol (hypocholesterolaemia is associated with preterm delivery. We can therefore recommend on this basis that the concept of an optimal range for maternal serum cholesterol during pregnancy may have merit and pregnant women should be encouraged to follow a healthy, balanced diet and ensure regular antenatal visit to their healthcare provider. [Int J Reprod Contracept Obstet Gynecol 2014; 3(2.000: 442-446

  1. Interaction between cholesterol and chitosan in Langmuir monolayers

    Directory of Open Access Journals (Sweden)

    Felippe J. Pavinatto

    2005-06-01

    Full Text Available Chitosan incorporated in the aqueous subphase is found to affect the Langmuir monolayers of cholesterol, causing the surface pressure and the surface potential isotherms to become more expanded. The mean molecular area per cholesterol molecule in the condensed monolayer increases from 53 Ų in the absence of chitosan to 61 Ų for a concentration of 0.100 mg/mL of chitosan in the subphase. If additional chitosan is incorporated in the subphase, no change is noted, which points to saturation in the effects from chitosan. The interaction between chitosan and cholesterol probably occurs via hydrogen bonding. The monolayer expansion is also manifested in the monolayer morphology, as indicated by Brewster angle microscopy measurements, where larger cholesterol domains are visualized when chitosan is present in the subphase.

  2. Alternative to decrease cholesterol in sheep milk cheeses.

    Science.gov (United States)

    Gómez-Cortés, P; Viturro, E; Juárez, M; de la Fuente, M A

    2015-12-01

    The presence of cholesterol in foods is of nutritional interest because high levels of this molecule in human plasma are associated with an increasing risk of cardiovascular disease and nowadays consumers are demanding healthier products. The goal of this experiment was to diminish the cholesterol content of Manchego, the most popular Spanish cheese manufactured from ewes milk. For this purpose three bulk milks coming from dairy ewe fed with 0 (Control), 3 and 6% of linseed supplement on their diet were used. Nine cheeses (3 per bulk milk) were manufactured and ripened for 3 months. Cholesterol of ewes milk cheese from 6% to 12% linseed supplemented diets decreased by 9.6% and 16.1% respectively, therefore supplying a healthier profile. In a second experiment, different sources of unsaturated fatty acids (rich in oleic, linoleic and α-linolenic acids) were supplemented to dairy ewes and no significant differences were found on cheese cholesterol levels. PMID:26041199

  3. Cellular Cholesterol Directly Activates Smoothened in Hedgehog Signaling.

    Science.gov (United States)

    Huang, Pengxiang; Nedelcu, Daniel; Watanabe, Miyako; Jao, Cindy; Kim, Youngchang; Liu, Jing; Salic, Adrian

    2016-08-25

    In vertebrates, sterols are necessary for Hedgehog signaling, a pathway critical in embryogenesis and cancer. Sterols activate the membrane protein Smoothened by binding its extracellular, cysteine-rich domain (CRD). Major unanswered questions concern the nature of the endogenous, activating sterol and the mechanism by which it regulates Smoothened. We report crystal structures of CRD complexed with sterols and alone, revealing that sterols induce a dramatic conformational change of the binding site, which is sufficient for Smoothened activation and is unique among CRD-containing receptors. We demonstrate that Hedgehog signaling requires sterol binding to Smoothened and define key residues for sterol recognition and activity. We also show that cholesterol itself binds and activates Smoothened. Furthermore, the effect of oxysterols is abolished in Smoothened mutants that retain activation by cholesterol and Hedgehog. We propose that the endogenous Smoothened activator is cholesterol, not oxysterols, and that vertebrate Hedgehog signaling controls Smoothened by regulating its access to cholesterol. PMID:27545348

  4. Cholesterol granuloma of the orbit: An atypical presentation

    Directory of Open Access Journals (Sweden)

    Syed A R Rizvi

    2014-01-01

    Full Text Available Cholesterol granuloma is a rare, well-defined lesion of the orbit. In the orbit, diploe of the frontal bone is involved almost exclusively. We report an atypical case of cholesterol granuloma involving superomedial quadrant of orbit. A 42-year-old male presented with progressive, painless, proptosis with infero-temporal displacement of left eye. A large mass was felt beneath the bony orbital margin in the superomedial quadrant of the left orbit. Computerized tomography (CT scan revealed an extraconal superomedial, heterogeneous enhancing mass which was isodense with brain and pushing the globe inferolaterally and anteriorly. Excision biopsy of the tumor revealed the typical features of a cholesterol granuloma without any epithelial elements. Cholesterol granuloma of the orbit is a rare entity, but it can be diagnosed and differentiated from other lesions of the superior orbit by its characteristic clinical, radiological and histopathological features. An appropriate intervention in time carries a good prognosis with almost no recurrence.

  5. Cholesterol-Lowering Probiotics as Potential Biotherapeutics for Metabolic Diseases

    Directory of Open Access Journals (Sweden)

    Manoj Kumar

    2012-01-01

    Full Text Available Cardiovascular diseases are one of the major causes of deaths in adults in the western world. Elevated levels of certain blood lipids have been reported to be the principal cause of cardiovascular disease and other disabilities in developed countries. Several animal and clinical trials have shown a positive association between cholesterol levels and the risks of coronary heart disease. Current dietary strategies for the prevention of cardiovascular disease advocate adherence to low-fat/low-saturated-fat diets. Although there is no doubt that, in experimental conditions, low-fat diets offer an effective means of reducing blood cholesterol concentrations on a population basis, these appear to be less effective, largely due to poor compliance, attributed to low palatability and acceptability of these diets to the consumers. Due to the low consumer compliance, attempts have been made to identify other dietary components that can reduce blood cholesterol levels. Supplementation of diet with fermented dairy products or lactic acid bacteria containing dairy products has shown the potential to reduce serum cholesterol levels. Various approaches have been used to alleviate this issue, including the use of probiotics, especially Bifidobacterium spp. and Lactobacillus spp.. Probiotics, the living microorganisms that confer health benefits on the host when administered in adequate amounts, have received much attention on their proclaimed health benefits which include improvement in lactose intolerance, increase in natural resistance to infectious disease in gastrointestinal tract, suppression of cancer, antidiabetic, reduction in serum cholesterol level, and improved digestion. In addition, there are numerous reports on cholesterol removal ability of probiotics and their hypocholesterolemic effects. Several possible mechanisms for cholesterol removal by probiotics are assimilation of cholesterol by growing cells, binding of cholesterol to cellular surface

  6. Emerging Roles for Cholesterol and Lipoproteins in Lung Disease

    OpenAIRE

    Gowdy, Kymberly M; Fessler, Michael B.

    2012-01-01

    Dyslipidemia, the condition of elevated serum triglycerides, elevated low-density lipoprotein cholesterol, and/or low high-density lipoprotein cholesterol, is a public health problem of growing concern. Dyslipidemia clusters with other disorders of the metabolic syndrome that together influence, and may derive from, chronic inflammation. While best recognized as a risk factor for atherosclerotic cardiovascular disease, lipid dysregulation has recently been shown to influence a variety of dise...

  7. Cholesterol Check (A Minute of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2015-09-10

    Heart disease and stroke are among the leading causes of death in the U.S. One of the main risk factors is high blood cholesterol. In this podcast, Dr. Carla Mercado discusses the importance of a healthy diet and regular screening to prevent high blood cholesterol.  Created: 9/10/2015 by MMWR.   Date Released: 9/10/2015.

  8. Preterm delivery and low maternal serum cholesterol level: any correlation?

    OpenAIRE

    Oluwole, Ayodeji A.; Maymunah A. Adegbesan-Omilabu; Kehinde S. Okunade

    2014-01-01

    Background: Preterm birth is a major challenge in perinatal health care with prematurity accounting for 40-60% of all perinatal deaths in Nigeria. The physiologic hypercholesterolaemia of later pregnancy suggests an adaptive function for pregnancy maintenance or fetal growth. Decreased levels of maternal total cholesterol and low-density lipoprotein cholesterol have been reported in association with preterm delivery. Methods: This was a prospective observational cohort study designed to a...

  9. Tissue cholesterol content alterations in streptozotocin-induced diabetic rats

    Institute of Scientific and Technical Information of China (English)

    Xin-ting WANG; Jia LI; Li LIU; Nan HU; Shi JIN; Can LIU; Dan MEI; Xiao-dong LIU

    2012-01-01

    Aim:Diabetes is associated with elevated serum total cholesterol level and disrupted lipoprotein subfractions.The aim of this study was to examine alterations in the tissue cholesterol contents closely related to diabetic complications.Methods:Intraperitoneal injection of streptozotocin was used to induce type 1 diabetes in adult male Sprague-Dawley rats.On d 35 after the injection,liver,heart,intestine,kidney,pancreas,cerebral cortex and hippocampus were isolated from the rats.The content of total and free cholesterol in the tissues was determined using HPLC.The ATP-binding cassette protein A1 (ABCA1) protein and ApoE mRNA were measured using Western blot and QT-PCR analyses,respectively.Results:In diabetic rats,the level of free cholesterol was significantly decreased in the peripheral tissues,but significantly elevated in hippocampus,as compared with those in the control rats.Diabetic rats showed a trend of decreasing the total cholesterol level in the peripheral tissues,but significant change was only found in kidney and liver.In diabetic rats,the level of the ABCA1 protein was significantly increased in the peripheral tissues and cerebral cortex; the expression of ApoE mRNA was slightly decreased in hippocampus and cerebral cortex,but the change had no statistical significance.Conclusion:Type 1 diabetes decreases the free cholesterol content in the peripheral tissues and increases the free cholesterol content in hippocampus.The decreased free cholesterol level in the peripheral tissues may be partly due to the increased expression of the ABCA1 protein.

  10. Optimizing Conditions to Cholesterol Adsorbed with Carboxymethyl Chitosan

    OpenAIRE

    Mardiyah Kurniasih; Dwi Kartika; Riyanti Riyanti

    2016-01-01

    A research on optimizing conditions to cholesterol adsorbed have been performed. Optimization was performed by varying: contact time, adsorbent weight and temperature of the system's. A full factorial experimental design was used in this study. Characterization performed on the synthesized chitosan and carboxymethyl chitosan including FTIR, water content, ash content, solubility, porosity, and swelling effect. The results showed that carboxymethyl chitosan able to adsorb cholesterol under con...

  11. HIV-Cholesterol Connection Suggests a New Antiretroviral Strategy

    OpenAIRE

    Zahedi Mujawar; Honor Rose; Morrow, Matthew P.; Tatiana Pushkarsky; Larisa Dubrovsky; Nigora Mukhamedova; Ying Fu; Anthony Dart; Orenstein, Jan M.; Bobryshev, Yuri V.; Michael Bukrinsky; Dmitri Sviridov

    2006-01-01

    Several steps of HIV-1 replication critically depend on cholesterol. HIV infection is associated with profound changes in lipid and lipoprotein metabolism and an increased risk of coronary artery disease. Whereas numerous studies have investigated the role of anti-HIV drugs in lipodystrophy and dyslipidemia, the effects of HIV infection on cellular cholesterol metabolism remain uncharacterized. Here, we demonstrate that HIV-1 impairs ATP-binding cassette transporter A1 (ABCA1)-dependent chole...

  12. Cholesterol depletion disorganizes oocyte membrane rafts altering mouse fertilization.

    Directory of Open Access Journals (Sweden)

    Jorgelina Buschiazzo

    Full Text Available Drastic membrane reorganization occurs when mammalian sperm binds to and fuses with the oocyte membrane. Two oocyte protein families are essential for fertilization, tetraspanins and glycosylphosphatidylinositol-anchored proteins. The firsts are associated to tetraspanin-enriched microdomains and the seconds to lipid rafts. Here we report membrane raft involvement in mouse fertilization assessed by cholesterol modulation using methyl-β-cyclodextrin. Cholesterol removal induced: (1 a decrease of the fertilization rate and index; and (2 a delay in the extrusion of the second polar body. Cholesterol repletion recovered the fertilization ability of cholesterol-depleted oocytes, indicating reversibility of these effects. In vivo time-lapse analyses using fluorescent cholesterol permitted to identify the time-point at which the probe is mainly located at the plasma membrane enabling the estimation of the extent of the cholesterol depletion. We confirmed that the mouse oocyte is rich in rafts according to the presence of the raft marker lipid, ganglioside GM1 on the membrane of living oocytes and we identified the coexistence of two types of microdomains, planar rafts and caveolae-like structures, by terms of two differential rafts markers, flotillin-2 and caveolin-1, respectively. Moreover, this is the first report that shows characteristic caveolae-like invaginations in the mouse oocyte identified by electron microscopy. Raft disruption by cholesterol depletion disturbed the subcellular localization of the signal molecule c-Src and the inhibition of Src kinase proteins prevented second polar body extrusion, consistent with a role of Src-related kinases in fertilization via signaling complexes. Our data highlight the functional importance of intact membrane rafts for mouse fertilization and its dependence on cholesterol.

  13. Apolipoprotein M promotes mobilization of cellular cholesterol in vivo

    DEFF Research Database (Denmark)

    Elsøe, Sara; Christoffersen, Christina; Luchoomun, Jayraz;

    2013-01-01

    The HDL associated apolipoprotein M (apoM) protects against experimental atherosclerosis but the mechanism is unknown. ApoM increases prebeta-HDL formation. We explored whether plasma apoM affects mobilization of cholesterol from peripheral cells in mice.......The HDL associated apolipoprotein M (apoM) protects against experimental atherosclerosis but the mechanism is unknown. ApoM increases prebeta-HDL formation. We explored whether plasma apoM affects mobilization of cholesterol from peripheral cells in mice....

  14. Cholesterol granuloma of the right epididymis mimicking an acute scrotum

    Institute of Scientific and Technical Information of China (English)

    Borislav Spajic; Hrvoje Cupic; Goran Stimac; Ivica Brigic; Bozo Kruslin; Ognjen Kraus

    2006-01-01

    @@ Dear Sir, I am B. Spajic, the urologist from Clinical Department of Urology, Sestre Milosrdnice University Hospital,Zagreb, Croatia. Recently, we had a rare case of a cholesterol granuloma of the right epididymis at our department, showing clinical signs of acute scrotum. The case described here appears to be the second reporting cholesterol granuloma in the epididymis and the first one presenting with clinical signs of acute scrotum.

  15. Elastic deformation and failure of lipid bilayer membranes containing cholesterol.

    OpenAIRE

    Needham, D; Nunn, R. S.

    1990-01-01

    Giant bilayer vesicles were reconstituted from several lipids and lipid/cholesterol (CHOL) mixtures: stearolyloleoylphosphatidylcholine (SOPC), bovine sphingomyelin (BSM), diarachidonylphosphatidylcholine (DAPC), SOPC/CHOL, BSM/CHOL, DAPC/CHOL, and extracted red blood cell (RBC) lipids with native cholesterol. Single-walled vesicles were manipulated by micropipette suction and several membrane material properties were determined. The properties measured were the elastic area compressibility m...

  16. Cholesterol-dependent hemolytic activity of Passiflora quadrangularis leaves

    Directory of Open Access Journals (Sweden)

    L.N. Yuldasheva

    2005-07-01

    Full Text Available Plants used in traditional medicine are rich sources of hemolysins and cytolysins, which are potential bactericidal and anticancer drugs. The present study demonstrates for the first time the presence of a hemolysin in the leaves of Passiflora quadrangularis L. This hemolysin is heat stable, resistant to trypsin treatment, has the capacity to froth, and acts very rapidly. The hemolysin activity is dose-dependent, with a slope greater than 1 in a double-logarithmic plot. Polyethylene glycols of high molecular weight were able to reduce the rate of hemolysis, while liposomes containing cholesterol completely inhibited it. In contrast, liposomes containing phosphatidylcholine were ineffective. The Passiflora hemolysin markedly increased the conductance of planar lipid bilayers containing cholesterol but was ineffective in cholesterol-free bilayers. Successive extraction of the crude hemolysin with n-hexane, chloroform, ethyl acetate, and n-butanol resulted in a 10-fold purification, with the hemolytic activity being recovered in the n-butanol fraction. The data suggest that membrane cholesterol is the primary target for this hemolysin and that several hemolysin molecules form a large transmembrane water pore. The properties of the Passiflora hemolysin, such as its frothing ability, positive color reaction with vanillin, selective extraction with n-butanol, HPLC profile, cholesterol-dependent membrane susceptibility, formation of a stable complex with cholesterol, and rapid erythrocyte lysis kinetics indicate that it is probably a saponin.

  17. Europium tetracycline biosensor for the determination of cholesterol

    Science.gov (United States)

    Courrol, Lilia Coronato; Silva, Flávia Rodrigues de Oliveira; Samad, Ricardo Elgul; Mansano, Ronaldo Domingues; Vieira, Nilson Dias, Jr.

    2007-02-01

    Development of cholesterol biosensors is of great importance in clinical analysis because the concentration of cholesterol in blood is a fundamental parameter for the prevention and diagnosis of a number of clinical disorders such as heart disease, hypertension and arteriosclerosis. In general, determination of cholesterol is based on spectrophotometry; but this method involves complicated procedures and the cost is high because expensive enzyme must be used in each assay. We report here the observation, for the first time, of the enhancement of Europium-Tetracycline complex emission in cholesterol solutions. This enhancement was initially observed with the addition of the enzyme cholesterol oxidase, which produces H IIO II, the agent driver of the Europium tetracycline complex, to the solution. However, it was found that the enzyme is not needed to enhance the luminescence. A calibration curve was determined, resulting in an easy-handling immobilization method with a cheap stable material. This method shows that the complex can be used as a sensor to determine cholesterol in biological systems with good selectivity, fast response, miniature size, and reproducible results.

  18. The Role of Cholesterol in Driving IAPP-Membrane Interactions.

    Science.gov (United States)

    Sciacca, Michele F M; Lolicato, Fabio; Di Mauro, Giacomo; Milardi, Danilo; D'Urso, Luisa; Satriano, Cristina; Ramamoorthy, Ayyalusamy; La Rosa, Carmelo

    2016-07-12

    Our knowledge of the molecular events underlying type 2 diabetes mellitus-a protein conformational disease characterized by the aggregation of islet amyloid polypeptide (IAPP) in pancreatic β cells-is limited. However, amyloid-mediated membrane damage is known to play a key role in IAPP cytotoxicity, and therefore the effects of lipid composition on modulating IAPP-membrane interactions have been the focus of intense research. In particular, membrane cholesterol content varies with aging and consequently with adverse environmental factors such as diet and lifestyle, but its role in the development of the disease is controversial. In this study, we employ a combination of experimental techniques and in silico molecular simulations to shed light on the role of cholesterol in IAPP aggregation and the related membrane disruption. We show that if anionic POPC/POPS vesicles are used as model membranes, cholesterol has a negligible effect on the kinetics of IAPP fibril growth on the surface of the bilayer. In addition, cholesterol inhibits membrane damage by amyloid-induced poration on membranes, but enhances leakage through fiber growth on the membrane surface. Conversely, if 1:2 DOPC/DPPC raft-like model membranes are used, cholesterol accelerates fiber growth. Next, it enhances pore formation and suppresses fiber growth on the membrane surface, leading to leakage. Our results highlight a twofold effect of cholesterol on the amyloidogenicity of IAPP and help explain its debated role in type 2 diabetes mellitus. PMID:27410742

  19. Cholesterol-dependent Conformational Plasticity in GPCR Dimers.

    Science.gov (United States)

    Prasanna, Xavier; Sengupta, Durba; Chattopadhyay, Amitabha

    2016-01-01

    The organization and function of the serotonin1A receptor, an important member of the GPCR family, have been shown to be cholesterol-dependent, although the molecular mechanism is not clear. We performed a comprehensive structural and dynamic analysis of dimerization of the serotonin1A receptor by coarse-grain molecular dynamics simulations totaling 3.6 ms to explore the molecular details of its cholesterol-dependent association. A major finding is that the plasticity and flexibility of the receptor dimers increase with increased cholesterol concentration. In particular, a dimer interface formed by transmembrane helices I-I was found to be sensitive to cholesterol. The modulation of dimer interface appears to arise from a combination of direct cholesterol occupancy and indirect membrane effects. Interestingly, the presence of cholesterol at the dimer interface is correlated with increased dimer plasticity and flexibility. These results represent an important step in characterizing the molecular interactions in GPCR organization with potential relevance to therapeutic interventions. PMID:27535203

  20. Remnant Cholesterol, Low-Density Lipoprotein Cholesterol, and Blood Pressure as Mediators From Obesity to Ischemic Heart Disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Smith, George Davey;

    2015-01-01

    RATIONALE: Obesity leads to increased ischemic heart disease (IHD) risk, but the risk is thought to be mediated through intermediate variables and may not be caused by increased weight per se. OBJECTIVE: To test the hypothesis that the increased IHD risk because of obesity is mediated through...... variables and using genetic variants associated with these. During ≤22 years of follow-up 13 945 participants developed IHD. The increased IHD risk caused by obesity was partly mediated through elevated levels of nonfasting remnant cholesterol and low-density lipoprotein cholesterol, through elevated blood...... obesity were low-density lipoprotein cholesterol with 8%, systolic blood pressure with 7%, and remnant cholesterol with 7% excess risk of IHD. Corresponding observational excess risks using conventional body mass index were 21%, 11%, and 20%, respectively. CONCLUSIONS: The increased IHD risk because...

  1. Effect of Moderate Alcohol Consumption on Parameters of Reverse Cholesterol Transport in Postmenopausal Women

    NARCIS (Netherlands)

    Sierksma, A.; Vermunt, S.H.F.; Lankhuizen, I.M.; Gaag, M.S. van der; Scheek, L.M.; Grobbee, D.E.; Tol, A. van; Hendriks, H.F.J.

    2004-01-01

    Background: Alcohol consumption is associated with increased high-density lipoprotein (HDL) cholesterol levels. One of the main antiatherogenic functions of HDL is reverse cholesterol transport. Three early steps of reverse cholesterol transport are (1) cellular cholesterol efflux, (2) plasma choles

  2. Plasma plant sterols serve as poor markers of cholesterol absorption in man

    NARCIS (Netherlands)

    Jakulj, Lily; Mohammed, Hussein; van Dijk, Theo H.; Boer, Theo; Turner, Scott; Groen, Albert K.; Vissers, Maud N.; Stroes, Erik S. G.

    2013-01-01

    The validation of the use of plasma plant sterols as a marker of cholesterol absorption is frail. Nevertheless, plant sterol concentrations are routinely used to describe treatment-induced changes in cholesterol absorption. Their use has also been advocated as a clinical tool to tailor cholesterol-l

  3. Trans-intestinal cholesterol effl ux is not mediated through high density lipoprotein

    NARCIS (Netherlands)

    Vrins, C.L.; Ottenhoff, R.; Oever, K. van den; Waart, D.R. de; Kruyt, J.K.; Zhao, Y.; Berkel, T.J. van; Havekes, L.M.; Aerts, J.M.; Eck, M. van; Rensen, P.C.; Groen, A.K.

    2012-01-01

    Transintestinal cholesterol efflux (TICE) provides an attractive target to increase body cholesterol excretion. At present, the cholesterol donor responsible for direct delivery of plasma cholesterol to the intestine is unknown. In this study, we investigated the role of HDL in TICE. ATP-binding cas

  4. Atorvastatin treatment lowers fasting remnant-like particle cholesterol and LDL subfraction cholesterol without affecting LDL size in type 2 diabetes mellitus : Relevance for non-HDL cholesterol and apolipoprotein B guideline targets

    NARCIS (Netherlands)

    Kappelle, Paul J. W. H.; Dallinga-Thie, Geesje M.; Dullaart, Robin P. F.

    2010-01-01

    The extent to which atorvastatin treatment affects LDL size, LDL subfraction levels and remnant-like particle cholesterol (RLP-C) was determined in type 2 diabetes. We also compared LDL size and RLP-C in relation to guideline cut-off values for LDL cholesterol, non-HDL cholesterol and apolipoprotein

  5. Atorvastatin treatment lowers fasting remnant-like particle cholesterol and LDL subfraction cholesterol without affecting LDL size in type 2 diabetes mellitus: Relevance for non-HDL cholesterol and apolipoprotein B guideline targets

    NARCIS (Netherlands)

    P.J.W.H. Kappelle; G.M. Dallinga-Thie; R.P.F. Dullaart

    2010-01-01

    The extent to which atorvastatin treatment affects LDL size, LDL subfraction levels and remnant-like particle cholesterol (RLP-C) was determined in type 2 diabetes. We also compared LDL size and RLP-C in relation to guideline cut-off values for LDL cholesterol, non-HDL cholesterol and apolipoprotein

  6. Hydrophobic ionic liquid immoblizing cholesterol oxidase on the electrodeposited Prussian blue on glassy carbon electrode for detection of cholesterol

    International Nuclear Information System (INIS)

    A novel cholesterol biosensor was fabricated on hydrophobic ionic liquid (IL)/aqueous solution interface. The hydrophobic IL thin film played a signal amplification role because it not only enriched the cholesterol from the aqueous solution, but also immobilized matrix for cholesterol oxidase (ChOx). Prussian blue (PB) as advanced sensing materials was used as effective low-potential electron transfer mediation toward hydrogen peroxide (H2O2). The fabricated IL-ChOx/PB/Glassy carbon electrode (GCE) was characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammogram (CV), respectively. And it exhibited a linear response to cholesterol in the range of 0.01–0.40 mM with a detection limit of 4.4 μM. In addition, the kinetics behavior of cholesterol at IL-Chox/PB/GCE electrode was examined, and the electrocatalytic mechanism was proposed as shown in first scheme. ChOx immobilized in hydrophobic IL thin film was used as the first electrocatalyst for the cholesterol into H2O2, and the PB film onto the GCE was used as the second electrocatalyst for the 2e− reduction of the produced H2O2 into H2O

  7. The origin of cholesterol in chyle demonstrated by nuclear indicator methods

    International Nuclear Information System (INIS)

    In order to obtain information about the mechanism of the intestinal absorption of cholesterol, rats having a lymphatic abdominal fistula are used. The animals receive either 4-14C- cholesterol subcutaneously or orally, or the 1-14C acetate. The study of the specific radio-activities of the cholesterol in chyle, in serum, in the lining, and in the intestinal contents makes it possible to define the roles played by the transfer cholesterol from the serum, by the cholesterol synthesised intestinally, and by the absorption cholesterol, in the formations of the lymph and of the chylomicrons. A new theory is proposed for the mechanism of cholesterol absorption. (author)

  8. Effects of lovastatin and dietary cholesterol on sterol homeostasis in healthy human subjects.

    OpenAIRE

    Duane, W C

    1993-01-01

    We measured biliary and fecal sterol outputs in 12 human subjects on a metabolic ward in four randomly allocated, 6-7 wk periods: (a) lovastatin (40 mg b.i.d.) + low cholesterol diet (mean 246 mg/d), (b) lovastatin + high cholesterol diet (mean 1,071 mg/d), (c) low cholesterol diet alone, (d) high cholesterol diet alone. In addition to lowering serum LDL cholesterol, lovastatin significantly lowered biliary secretion of cholesterol, fecal output of endogenous neutral sterols, cholesterol bala...

  9. Cosmogenic photons strongly constrain UHECR source models

    CERN Document Server

    van Vliet, Arjen

    2016-01-01

    With the newest version of our Monte Carlo code for ultra-high-energy cosmic ray (UHECR) propagation, CRPropa 3, the flux of neutrinos and photons due to interactions of UHECRs with extragalactic background light can be predicted. Together with the recently updated data for the isotropic diffuse gamma-ray background (IGRB) by Fermi LAT, it is now possible to severely constrain UHECR source models. The evolution of the UHECR sources especially plays an important role in the determination of the expected secondary photon spectrum. Pure proton UHECR models are already strongly constrained, primarily by the highest energy bins of Fermi LAT's IGRB, as long as their number density is not strongly peaked at recent times.

  10. Global marine primary production constrains fisheries catches.

    Science.gov (United States)

    Chassot, Emmanuel; Bonhommeau, Sylvain; Dulvy, Nicholas K; Mélin, Frédéric; Watson, Reg; Gascuel, Didier; Le Pape, Olivier

    2010-04-01

    Primary production must constrain the amount of fish and invertebrates available to expanding fisheries; however the degree of limitation has only been demonstrated at regional scales to date. Here we show that phytoplanktonic primary production, estimated from an ocean-colour satellite (SeaWiFS), is related to global fisheries catches at the scale of Large Marine Ecosystems, while accounting for temperature and ecological factors such as ecosystem size and type, species richness, animal body size, and the degree and nature of fisheries exploitation. Indeed we show that global fisheries catches since 1950 have been increasingly constrained by the amount of primary production. The primary production appropriated by current global fisheries is 17-112% higher than that appropriated by sustainable fisheries. Global primary production appears to be declining, in some part due to climate variability and change, with consequences for the near future fisheries catches.

  11. Doubly Constrained Robust Blind Beamforming Algorithm

    Directory of Open Access Journals (Sweden)

    Xin Song

    2013-01-01

    Full Text Available We propose doubly constrained robust least-squares constant modulus algorithm (LSCMA to solve the problem of signal steering vector mismatches via the Bayesian method and worst-case performance optimization, which is based on the mismatches between the actual and presumed steering vectors. The weight vector is iteratively updated with penalty for the worst-case signal steering vector by the partial Taylor-series expansion and Lagrange multiplier method, in which the Lagrange multipliers can be optimally derived and incorporated at each step. A theoretical analysis for our proposed algorithm in terms of complexity cost, convergence performance, and SINR performance is presented in this paper. In contrast to the linearly constrained LSCMA, the proposed algorithm provides better robustness against the signal steering vector mismatches, yields higher signal captive performance, improves greater array output SINR, and has a lower computational cost. The simulation results confirm the superiority of the proposed algorithm on beampattern control and output SINR enhancement.

  12. Efficient caching for constrained skyline queries

    DEFF Research Database (Denmark)

    Mortensen, Michael Lind; Chester, Sean; Assent, Ira;

    2015-01-01

    Constrained skyline queries retrieve all points that optimize some user’s preferences subject to orthogonal range constraints, but at significant computational cost. This paper is the first to propose caching to improve constrained skyline query response time. Because arbitrary range constraints...... are unlikely to match a cached query exactly, our proposed method identifies and exploits similar cached queries to reduce the computational overhead of subsequent ones. We consider interactive users posing a string of similar queries and show how these can be classified into four cases based on how...... they overlap cached queries. For each we present a specialized solution. For the general case of independent users, we introduce the Missing Points Region (MPR), that minimizes disk reads, and an approximation of the MPR. An extensive experimental evaluation reveals that the querying for an (approximate) MPR...

  13. Constraining the braneworld with gravitational wave observations.

    Science.gov (United States)

    McWilliams, Sean T

    2010-04-01

    Some braneworld models may have observable consequences that, if detected, would validate a requisite element of string theory. In the infinite Randall-Sundrum model (RS2), the AdS radius of curvature, l, of the extra dimension supports a single bound state of the massless graviton on the brane, thereby reproducing Newtonian gravity in the weak-field limit. However, using the AdS/CFT correspondence, it has been suggested that one possible consequence of RS2 is an enormous increase in Hawking radiation emitted by black holes. We utilize this possibility to derive two novel methods for constraining l via gravitational wave measurements. We show that the EMRI event rate detected by LISA can constrain l at the approximately 1 microm level for optimal cases, while the observation of a single galactic black hole binary with LISA results in an optimal constraint of l < or = 5 microm. PMID:20481929

  14. Patterns of cholesterol metabolism: pathophysiological and therapeutic implications for dyslipidemias and the metabolic syndrome.

    Science.gov (United States)

    Lupattelli, G; De Vuono, S; Mannarino, E

    2011-09-01

    Investigating cholesterol metabolism, which derives from balancing cholesterol synthesis and absorption, opens new perspectives in the pathogenesis of dyslipidemias and the metabolic syndrome (MS). Cholesterol metabolism is studied by measuring plasma levels of campesterol, sitosterol and cholestanol, that is, plant sterols which are recognised as surrogate cholesterol-absorption markers and lathosterol or squalene, that is, cholesterol precursors, which are considered surrogate cholesterol-synthesis markers. This article presents current knowledge on cholesterol synthesis and absorption, as evaluated by means of cholesterol precursors and plant sterols, and discusses patterns of cholesterol balance in the main forms of primary hyperlipidaemia and MS. Understanding the mechanism(s) underlying these patterns of cholesterol synthesis and absorption will help to predict the response to hypolipidemic treatment, which can then be tailored to ensure the maximum clinical benefit for patients.

  15. Constraining RRc candidates using SDSS colours

    CERN Document Server

    Bányai, E; Molnár, L; Dobos, L; Szabó, R

    2016-01-01

    The light variations of first-overtone RR Lyrae stars and contact eclipsing binaries can be difficult to distinguish. The Catalina Periodic Variable Star catalog contains several misclassified objects, despite the classification efforts by Drake et al. (2014). They used metallicity and surface gravity derived from spectroscopic data (from the SDSS database) to rule out binaries. Our aim is to further constrain the catalog using SDSS colours to estimate physical parameters for stars that did not have spectroscopic data.

  16. NEW SIMULATED ANNEALING ALGORITHMS FOR CONSTRAINED OPTIMIZATION

    OpenAIRE

    LINET ÖZDAMAR; CHANDRA SEKHAR PEDAMALLU

    2010-01-01

    We propose a Population based dual-sequence Non-Penalty Annealing algorithm (PNPA) for solving the general nonlinear constrained optimization problem. The PNPA maintains a population of solutions that are intermixed by crossover to supply a new starting solution for simulated annealing throughout the search. Every time the search gets stuck at a local optimum, this crossover procedure is triggered and simulated annealing search re-starts from a new subspace. In both the crossover and simulate...

  17. NTRU software implementation for constrained devices

    OpenAIRE

    Monteverde Giacomino, Mariano

    2008-01-01

    The NTRUEncrypt is a public-key cryptosystem based on the shortest vector problem. Its main characteristics are the low memory and computational requirements while providing a high security level. This document presents an implementation and optimization of the NTRU public-key cryptosys- tem for constrained devices. Speci cally the NTRU cryptosystem has been implemented on the ATMega128 and the ATMega163 microcontrollers. This has turned in a major e ort in order to reduce t...

  18. Performance Characteristics of Active Constrained Layer Damping

    OpenAIRE

    A. Baz; J. Ro

    1995-01-01

    Theoretical and experimental performance characteristics of the new class of actively controlled constrained layer damping (ACLD) are presented. The ACLD consists of a viscoelastic damping layer sandwiched between two layers of piezoelectric sensor and actuator. The composite ACLD when bonded to a vibrating structure acts as a “smart” treatment whose shear deformation can be controlled and tuned to the structural response in order to enhance the energy dissipation mechanism and improve the vi...

  19. Murder and Self-constrained Modernity

    DEFF Research Database (Denmark)

    Hansen, Kim Toft

    with metaphysical assumptions. These trends are as well in evidence in the writings of the Swedish author Henning Mankell where he opens up discussions of inapproachable violence – a certain type of violence that he designates ‘the Swedish uneasiness’ – especially the brief short story “Sprickan” (“The Fracture......-constrained. The meeting ground between modernity and religion is, then, a metaphysics of uncertainty....

  20. Constrained simulation of the Bullet Cluster

    International Nuclear Information System (INIS)

    In this work, we report on a detailed simulation of the Bullet Cluster (1E0657-56) merger, including magnetohydrodynamics, plasma cooling, and adaptive mesh refinement. We constrain the simulation with data from gravitational lensing reconstructions and the 0.5-2 keV Chandra X-ray flux map, then compare the resulting model to higher energy X-ray fluxes, the extracted plasma temperature map, Sunyaev-Zel'dovich effect measurements, and cluster halo radio emission. We constrain the initial conditions by minimizing the chi-squared figure of merit between the full two-dimensional (2D) observational data sets and the simulation, rather than comparing only a few features such as the location of subcluster centroids, as in previous studies. A simple initial configuration of two triaxial clusters with Navarro-Frenk-White dark matter profiles and physically reasonable plasma profiles gives a good fit to the current observational morphology and X-ray emissions of the merging clusters. There is no need for unconventional physics or extreme infall velocities. The study gives insight into the astrophysical processes at play during a galaxy cluster merger, and constrains the strength and coherence length of the magnetic fields. The techniques developed here to create realistic, stable, triaxial clusters, and to utilize the totality of the 2D image data, will be applicable to future simulation studies of other merging clusters. This approach of constrained simulation, when applied to well-measured systems, should be a powerful complement to present tools for understanding X-ray clusters and their magnetic fields, and the processes governing their formation.