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Sample records for cellular cholesterol export

  1. 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

  2. Effect of cellular cholesterol depletion on rabies virus infection.

    Science.gov (United States)

    Hotta, Kozue; Bazartseren, Boldbarrtar; Kaku, Yoshihiro; Noguchi, Akira; Okutani, Akiko; Inoue, Satoshi; Yamada, Akio

    2009-01-01

    Although there are several reports on candidates for rabies virus (RABV) receptor, possible roles played by these receptor candidates in determination of highly neurotropic nature of RABV have not been well understood. Since these candidate receptors for RABV were reported to be frequently associated with cholesterol-rich microdomains characterized by lipid rafts and caveolae structures, we attempted to determine whether the disturbance of microdomains caused by the cholesterol depletion showed any effects on RABV infection. When the cellular cholesterol was depleted by methyl-beta-cyclodextrin (MBCD) treatment, increase in RABV adsorption and infection, but not multiplication rather than suppression was observed in both BHK-21 and HEp-2 cells. These effects exerted by MBCD treatment on RABV infection could be reversed by cholesterol reconstitution. These results suggest that RABV enters BHK-21 or HEp-2 cells through ports of entry other than those located on cholesterol-rich microdomains and raise the possibility that RABV uses different mechanisms to enter the non-neuronal cells. PMID:19010362

  3. Membrane plasmalogen composition and cellular cholesterol regulation: a structure activity study

    OpenAIRE

    Su-Myat Khine K; Khan Mohamed A; Ritchie Shawn A; Jayasinghe Dushmanthi; Ma Hong; Ahiahonu Pearson WK; Mankidy Rishikesh; Wood Paul L; Goodenowe Dayan B

    2010-01-01

    Abstract Background Disrupted cholesterol regulation leading to increased circulating and membrane cholesterol levels is implicated in many age-related chronic diseases such as cardiovascular disease (CVD), Alzheimer's disease (AD), and cancer. In vitro and ex vivo cellular plasmalogen deficiency models have been shown to exhibit impaired intra- and extra-cellular processing of cholesterol. Furthermore, depleted brain plasmalogens have been implicated in AD and serum plasmalogen deficiencies ...

  4. Detectors for evaluating the cellular landscape of sphingomyelin- and cholesterol-rich membrane domains.

    Science.gov (United States)

    Kishimoto, Takuma; Ishitsuka, Reiko; Kobayashi, Toshihide

    2016-08-01

    Although sphingomyelin and cholesterol are major lipids of mammalian cells, the detailed distribution of these lipids in cellular membranes remains still obscure. However, the recent development of protein probes that specifically bind sphingomyelin and/or cholesterol provides new information about the landscape of the lipid domains that are enriched with sphingomyelin or cholesterol or both. Here, we critically summarize the tools to study distribution and dynamics of sphingomyelin and cholesterol. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon. PMID:26993577

  5. 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

  6. 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....

  7. Membrane plasmalogen composition and cellular cholesterol regulation: a structure activity study

    Directory of Open Access Journals (Sweden)

    Su-Myat Khine K

    2010-06-01

    Full Text Available Abstract Background Disrupted cholesterol regulation leading to increased circulating and membrane cholesterol levels is implicated in many age-related chronic diseases such as cardiovascular disease (CVD, Alzheimer's disease (AD, and cancer. In vitro and ex vivo cellular plasmalogen deficiency models have been shown to exhibit impaired intra- and extra-cellular processing of cholesterol. Furthermore, depleted brain plasmalogens have been implicated in AD and serum plasmalogen deficiencies have been linked to AD, CVD, and cancer. Results Using plasmalogen deficient (NRel-4 and plasmalogen sufficient (HEK293 cells we investigated the effect of species-dependent plasmalogen restoration/augmentation on membrane cholesterol processing. The results of these studies indicate that the esterification of cholesterol is dependent upon the amount of polyunsaturated fatty acid (PUFA-containing ethanolamine plasmalogen (PlsEtn present in the membrane. We further elucidate that the concentration-dependent increase in esterified cholesterol observed with PUFA-PlsEtn was due to a concentration-dependent increase in sterol-O-acyltransferase-1 (SOAT1 levels, an observation not reproduced by 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA reductase inhibition. Conclusion The present study describes a novel mechanism of cholesterol regulation that is consistent with clinical and epidemiological studies of cholesterol, aging and disease. Specifically, the present study describes how selective membrane PUFA-PlsEtn enhancement can be achieved using 1-alkyl-2-PUFA glycerols and through this action reduce levels of total and free cholesterol in cells.

  8. Control of cellular cholesterol efflux by the nuclear oxysterol receptor LXRα

    OpenAIRE

    Venkateswaran, Asha; Laffitte, Bryan A.; Joseph, Sean B.; Mak, Puiying A.; Wilpitz, Damien C.; Edwards, Peter A.; Tontonoz, Peter

    2000-01-01

    LXRα is a nuclear receptor that has previously been shown to regulate the metabolic conversion of cholesterol to bile acids. Here we define a role for this transcription factor in the control of cellular cholesterol efflux. We demonstrate that retroviral expression of LXRα in NIH 3T3 fibroblasts or RAW264.7 macrophages and/or treatment of these cells with oxysterol ligands of LXR results in 7- to 30-fold induction of the mRNA encoding the putative cholesterol/phospholi...

  9. A comparative study on fluorescent cholesterol analogs as versatile cellular reporters

    DEFF Research Database (Denmark)

    Sezgin, Erdinc; Betul Can, Fatma; Schneider, Falk;

    2016-01-01

    for their performance in cellular assays: 1) plasma membrane incorporation, specifically the preference for more ordered membrane environments in phase separated giant unilamellar vesicles (GUVs) and giant plasma membrane vesicles (GPMVs); 2) cellular trafficking, specifically subcellular localization in Niemann-Pick C......Cholesterol is a crucial component of cellular membranes, but knowledge of its intracellular dynamics is scarce. Thus, it is of utmost interest to develop tools for visualization of cholesterol organization and dynamics in cells and tissues. For this purpose, many studies make use of fluorescently......-labeled cholesterol analogs. Unfortunately, the introduction of the label may influence the characteristics of the analog, such as its localization, interaction and trafficking in cells, hence it is important to get knowledge of such bias. In this report, we compared different fluorescent lipid analogs...

  10. Cellular Cholesterol Distribution Influences Proteolytic Release of the LRP-1 Ectodomain

    Science.gov (United States)

    Dekky, Bassil; Wahart, Amandine; Sartelet, Hervé; Féré, Michaël; Angiboust, Jean-François; Dedieu, Stéphane; Piot, Olivier; Devy, Jérôme; Emonard, Hervé

    2016-01-01

    Low-density lipoprotein receptor-related protein-1 (LRP-1) is a multifunctional matricellular receptor composed of a large ligand-binding subunit (515-kDa α-chain) associated with a short trans-membrane subunit (85-kDa β-chain). LRP-1, which exhibits both endocytosis and cell signaling properties, plays a key role in tumor invasion by regulating the activity of proteinases such as matrix metalloproteinases (MMPs). LRP-1 is shed at the cell surface by proteinases such as membrane-type 1 MMP (MT1-MMP) and a disintegrin and metalloproteinase-12 (ADAM-12). Here, we show by using biophysical, biochemical, and cellular imaging approaches that efficient extraction of cell cholesterol and increased LRP-1 shedding occur in MDA-MB-231 breast cancer cells but not in MDA-MB-435 cells. Our data show that cholesterol is differently distributed in both cell lines; predominantly intracellularly for MDA-MB-231 cells and at the plasma membrane for MDA-MB-435 cells. This study highlights the relationship between the rate and cellular distribution of cholesterol and its impact on LRP-1 shedding modulation. Altogether, our data strongly suggest that the increase of LRP-1 shedding upon cholesterol depletion induces a higher accessibility of the sheddase substrate, i.e., LRP-1, at the cell surface rather than an increase of expression of the enzyme. PMID:26903870

  11. EFFECT OF ACUPUNCTURE TREATMENT ON CELLULAR HEMORHEOLOGY,CHOLESTEROL AND TRIGLYCERIDE OF SIMPLE OBESITY PATIENTS

    Institute of Scientific and Technical Information of China (English)

    赵宁侠; 郭瑞林; 任秦有; 张周良; 史恒军

    2004-01-01

    Objective: To observe the effect of acupuncture on simple obesity and cellular hemorheology. Methods: Thirty-two cases of simple obesity patients were enrolled into this study. Acupoints of the Stomach Meridian and Spleen Meridian as Zhongwan (中脘CV 12), Liangmen (梁门ST 21), Tianshu (天枢ST 25), Guanyuan (关元CV 4), etc. were punctured, once daily in the first 5 days, and once every other day afterwards, with 10 sessions being a therapeutic course. Before treatment and after 3 courses of treatment, the body weight, waistline, weight index, serum cholesterol (CH), triglyceride and aggregation index of red blood cell (RBC) were detected. Results: After acupuncture treatment, all the indexes of body weight, waistline, weight index, serum CH, triglyceride and aggregation index of RBC decreased significantly in comparison with those of pre-treatment (P<0.05). Conclusion: Acupuncture can apparently improve cellular hemorheology, reduce body weight, serum cholesterol and TG levels in simple obesity patients.

  12. A comparative study on fluorescent cholesterol analogs as versatile cellular reporters.

    Science.gov (United States)

    Sezgin, Erdinc; Can, Fatma Betul; Schneider, Falk; Clausen, Mathias P; Galiani, Silvia; Stanly, Tess A; Waithe, Dominic; Colaco, Alexandria; Honigmann, Alf; Wüstner, Daniel; Platt, Frances; Eggeling, Christian

    2016-02-01

    Cholesterol (Chol) is a crucial component of cellular membranes, but knowledge of its intracellular dynamics is scarce. Thus, it is of utmost interest to develop tools for visualization of Chol organization and dynamics in cells and tissues. For this purpose, many studies make use of fluorescently labeled Chol analogs. Unfortunately, the introduction of the label may influence the characteristics of the analog, such as its localization, interaction, and trafficking in cells; hence, it is important to get knowledge of such bias. In this report, we compared different fluorescent lipid analogs for their performance in cellular assays: 1) plasma membrane incorporation, specifically the preference for more ordered membrane environments in phase-separated giant unilamellar vesicles and giant plasma membrane vesicles; 2) cellular trafficking, specifically subcellular localization in Niemann-Pick type C disease cells; and 3) applicability in fluorescence correlation spectroscopy (FCS)-based and super-resolution stimulated emission depletion-FCS-based measurements of membrane diffusion dynamics. The analogs exhibited strong differences, with some indicating positive performance in the membrane-based experiments and others in the intracellular trafficking assay. However, none showed positive performance in all assays. Our results constitute a concise guide for the careful use of fluorescent Chol analogs in visualizing cellular Chol dynamics. PMID:26701325

  13. Uptake of dexamethasone incorporated into liposomes by macrophages and foam cells and its inhibitory effect on cellular cholesterol ester accumulation.

    Science.gov (United States)

    Chono, Sumio; Morimoto, Kazuhiro

    2006-09-01

    To confirm the efficacy of dexamethasone incorporated into liposomes in the treatment of atherosclerosis, the uptake of dexamethasone-liposomes by macrophages and foam cells and its inhibitory effect on cellular cholesterol ester accumulation in these cells were investigated in-vitro. Dexamethasone-liposomes were prepared with egg yolk phosphatidylcholine, cholesterol and dicetylphosphate in a lipid molar ratio of 7/2/1 by the hydration method. This was adjusted to three different particle sizes to clarify the influence of particle size on the uptake by the macrophages and foam cells, and the inhibitory effect on cellular cholesterol ester accumulation. The distribution of particle sizes of dexamethasone-liposomes were 518.7+/-49.5 nm (L500), 202.2+/-23.1 nm (L200), and 68.6+/-6.5 nm (L70), respectively. For each size, dexamethasone concentration and dexamethasone/lipid molar ratio in dexamethasone-liposome suspension were 1 mg dexamethasone mL-1 and 0.134 mol dexamethasone mol-1 total lipids, respectively. The zeta potential was approximately -70 mV for all sizes. Dexamethasone-liposomes or free dexamethasone were added to the macrophages in the presence of oxidized low density lipoprotein (oxLDL) and foam cells, and then incubated at 37 degrees C. The uptake amount of dexamethasone by the macrophages and foam cells after a 24-h incubation was L500>L200>free dexamethasone>L70. The macrophages in the presence of oxLDL and foam cells were incubated with dexamethasone-liposomes or free dexamethasone for 24 h at 37 degrees C to evaluate the inhibitory effect on the cellular cholesterol ester accumulation. The cellular cholesterol ester level in the macrophages treated with oxLDL was significantly increased compared with that in macrophages without additives. L500, L200 and free dexamethasone significantly inhibited this cholesterol ester accumulation. L500, L200 and free dexamethasone also significantly reduced cellular cholesterol ester accumulation in foam cells. In

  14. Translocation Biosensors – Cellular System Integrators to Dissect CRM1-Dependent Nuclear Export by Chemicogenomics

    Directory of Open Access Journals (Sweden)

    Roland H. Stauber

    2009-07-01

    Full Text Available Fluorescent protein biosensors are powerful cellular systems biology tools for dissecting the complexity of cellular processes with high spatial and temporal resolution. As regulated nucleo-cytoplasmic transport is crucial for the modulation of numerous (pathophysiological cellular responses, a detailed understanding of its molecular mechanism would open up novel options for a rational manipulation of the cell. In contrast to genetic approaches, we here established and employed high-content cellular translocation biosensors applicable for dissecting nuclear export by chemicogenomics. A431 cell lines, stably expressing a translocation biosensor composed of glutathione S-transferase, GFP and a rational combination of nuclear import and export signals, were engineered by antibiotic selection and flow cytometry sorting. Using an optimized nuclear translocation algorithm, the translocation response could be robustly quantified on the Cellomics Arrayscan® VTI platform. Subsequent to assay optimization, the assay was developed into a higher density 384-well format high-content assay and employed for the screening of the 17K ChemBioNet compound collection. This library was selected on the basis of a genetic algorithm used to identify maximum common chemical substructures in a database of annotated bioactive molecules and hence, is well-placed in the chemical space covered by bioactive compounds. Automated multiparameter data analysis combined with visual inspection allowed us to identify and to rationally discriminate true export inhibitors from false positives, which included fluorescent compounds or cytotoxic substances that dramatically affected the cellular morphology. A total of 120 potential hit compounds were selected for Cellomics Arrayscan® VTI based rescreening. The export inhibitory activity of 20 compounds effective at concentrations < 25 μM were confirmed by fluorescence microscopy in several cell lines. Interestingly, kinetic analysis

  15. The interaction of the cellular export adaptor protein Aly/REF with ICP27 contributes to the efficiency of herpes simplex virus 1 mRNA export.

    Science.gov (United States)

    Tian, Xiaochen; Devi-Rao, Gayathri; Golovanov, Alexander P; Sandri-Goldin, Rozanne M

    2013-07-01

    Herpes simplex virus 1 (HSV-1) protein ICP27 enables viral mRNA export by accessing the cellular mRNA export receptor TAP/NXF, which guides mRNA through the nuclear pore complex. ICP27 binds viral mRNAs and interacts with TAP/NXF, providing a link to the cellular mRNA export pathway. ICP27 also interacts with the mRNA export adaptor protein Aly/REF, which binds cellular mRNAs and also interacts with TAP/NXF. Studies using small interfering RNA (siRNA) knockdown indicated that Aly/REF is not required for cellular mRNA export, and similar knockdown studies during HSV-1 infection led us to conclude that Aly/REF may be dispensable for viral RNA export. Recently, the structural basis of the interaction of ICP27 with Aly/REF was elucidated at atomic resolution, and it was shown that three ICP27 residues, W105, R107, and L108, interface with the RNA recognition motif (RRM) domain of Aly/REF. Here, to determine the role the interaction of ICP27 and Aly/REF plays during infection, these residues were mutated to alanine, and a recombinant virus, WRL-A, was constructed. Virus production was reduced about 10-fold during WRL-A infection, and export of ICP27 protein and most viral mRNAs was less efficient. We conclude that interaction of ICP27 with Aly/REF contributes to efficient viral mRNA export.

  16. Macrophage ABCA5 deficiency influences cellular cholesterol efflux and increases susceptibility to atherosclerosis in female LDLr knockout mice

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Dan, E-mail: y.dan@lacdr.leidenuniv.nl [Division of Biopharmaceutics, LACDR, Leiden University (Netherlands); Meurs, Illiana [Division of Biopharmaceutics, LACDR, Leiden University (Netherlands); Ohigashi, Megumi [Department of Cell Membrane Biology, Institute of Scientific and Industrial Research, Osaka University (Japan); Calpe-Berdiel, Laura; Habets, Kim L.L.; Zhao, Ying [Division of Biopharmaceutics, LACDR, Leiden University (Netherlands); Kubo, Yoshiyuki [Division of Pharmaceutical Sciences, Graduate School of Natural Science and Technology, Kanazawa University (Japan); Yamaguchi, Akihito [Department of Cell Membrane Biology, Institute of Scientific and Industrial Research, Osaka University (Japan); Van Berkel, Theo J.C. [Division of Biopharmaceutics, LACDR, Leiden University (Netherlands); Nishi, Tsuyoshi [Department of Cell Membrane Biology, Institute of Scientific and Industrial Research, Osaka University (Japan); Van Eck, Miranda [Division of Biopharmaceutics, LACDR, Leiden University (Netherlands)

    2010-05-07

    Objectives: To determine the role of macrophage ATP-binding cassette transporter A5 (ABCA5) in cellular cholesterol homeostasis and atherosclerotic lesion development. Methods and results: Chimeras with dysfunctional macrophage ABCA5 (ABCA5{sup -M/-M}) were generated by transplantation of bone marrow from ABCA5 knockout (ABCA5{sup -/-}) mice into irradiated LDLr{sup -/-} mice. In vitro, bone marrow-derived macrophages from ABCA5{sup -M/-M} chimeras exhibited a 29% (P < 0.001) decrease in cholesterol efflux to HDL, whereas a 21% (P = 0.07) increase in cholesterol efflux to apoA-I was observed. Interestingly, expression of ABCA1, but not ABCG1, was up-regulated in absence of functional ABCA5 in macrophages. To induce atherosclerosis, the transplanted LDLr{sup -/-} mice were fed a high-cholesterol Western-type diet (WTD) for 6, 10, or 18 weeks, allowing analysis of effects on initial as well as advanced lesion development. Atherosclerosis development was not affected in male ABCA5{sup -M/-M} chimeras after 6, 10, and 18 weeks WTD feeding. However, female ABCA5{sup -M/-M} chimeras did develop significantly (P < 0.05) larger aortic root lesions as compared with female controls after 6 and 10 weeks WTD feeding. Conclusions: ABCA5 influences macrophage cholesterol efflux, and selective disruption of ABCA5 in macrophages leads to increased atherosclerotic lesion development in female LDLr{sup -/-} mice.

  17. Identification of multidrug resistance protein 1 (MRP1/ABCC1) as a molecular gate for cellular export of cobalamin

    DEFF Research Database (Denmark)

    Beedholm-Ebsen, Rasmus; van de Wetering, Koen; Hardlei, Tore;

    2010-01-01

    Cobalamin (Cbl, vitamin B(12)) deficiency in humans is a cause of hematologic and neurologic disorders. We show here that the cellular export of Cbl, in contrast to the carrier- and receptor-dependent cellular import of Cbl, occurs by transmembrane transport of "free" Cbl. Screening of candidate...... and kidney. In contrast, Cbl accumulates in the terminal part of the intestine of these mice, suggesting a functional malabsorption because of a lower epithelial basolateral Cbl efflux. The identification of this Cbl export mechanism now allows the delineation of a coherent pathway for Cbl trafficking from...

  18. Curcumin inhibits cellular cholesterol accumulation by regulating SREBP-1/caveolin-1 signaling pathway in vascular smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    Hao-yu YUAN; Shuang-yu KUANG; Xing ZHENG; Hong-yan LING; Yun-bo YANG; Peng-ke YAN; Kai LI; Duan-fang LIAO

    2008-01-01

    Aim: To investigate the protective effect and the possible mechanism of curcumin on anti-atherosclerosis. Methods: Morphological changes of atherosclerotic le-sions taken from apoE knockout (apoE-/-) mice were determined by hematoxylin-eosin staining. Intracellular lipid droplets and lipid levels were assayed by oil red O staining and HPLC. The protein expression of caveolin-1 was quantified by West-ern blotting. Translocation and the expression of sterol response element-bind-ing protein-1 (SREBP-1) were indirectly detected by an immunofluorescence analysis. Results: The administration of 20 mg.kg-1.d-1 curcumin to apoE-/1 mice for 4 months induced a 50% reduction of atherosclerotic lesions and yielded a 5-fold increase in the caveolin-1 expression level as compared to the model group. Rat vascular smooth muscle cells (VSMC) pretreated with 50 mg.L-1 ox-lipid den-sity lipoprotein(ox-LDL) for 48 h increased cellular lipid contents, and stimulated SREBP-1 translocation, but decreased the caveolin-1 expression level. Lipid-loaded cells exposed to curcumin at various concentrations (12.5, 25, and 50 μmol.L-1) for different durations (0, 6, 12, 24, and 48 h) significantly diminished the number and area of cellular lipid droplets, total cholesterol, cholesterol ester, and free choles-terol accompanying the elevation of the caveolin-1 expression level (approximately 3-fold); the translocation of SREBP-1 from the cytoplasm to the nucleus was inhibited compared with the models. Lipid-loaded VSMC exposed to N-acetyl-Leu-Leu-norleucinal, a SREBP-1 protease inhibitor, showed increased nuclear trans-location of SREBP-1, reduced caveolin-1 expression level, and upregulated cellu-lar lipid levels. Conclusion: Curcumin inhibits ox-LDL-induced cholesterol accu-mulation in cultured VSMC through increasing the caveolin-1 expression via the inhibition of nuclear translocation of SREBP-1.

  19. ABCC6 : a new player in cellular cholesterol and lipoprotein metabolism?

    OpenAIRE

    Kuzaj, Patricia; Kuhn, Joachim; Dabisch-Ruthe, Mareike; Faust, Isabel; Götting, Christian; Knabbe, Cornelius; Hendig, Doris

    2014-01-01

    Background Dysregulations in cholesterol and lipid metabolism have been linked to human diseases like hypercholesterolemia, atherosclerosis or the metabolic syndrome. Many ABC transporters are involved in trafficking of metabolites derived from these pathways. Pseudoxanthoma elasticum (PXE), an autosomal-recessive disease caused by ABCC6 mutations, is characterized by atherogenesis and soft tissue calcification. Methods In this study we investigated the regulation of cholesterol biosynthesis ...

  20. Incorporation of cholesterol into the cellular membrane of Lactobacillus acidophilus ATCC 43121

    International Nuclear Information System (INIS)

    Cholesterol that was assimilated by Lactobacillus acidophilus ATCC 43121 was not metabolically degraded; most of it was recovered with the cells. Cells that were grown in the presence of cholesterol micelles and bile salts were more resistant to lysis by sonication than were those grown in their absence, suggesting a possible alteration of the cell wall or membrane. Cholesterol assimilation occurred during growth at pH 6.0 as well as during growth without pH control. Part of the cholesterol that was assimilated by cells was recovered in the membrane fractions of cells grown under both conditions. There was no difference in the amount taken up from cholesterol micelles that were prepared using dioleoyl L-alpha-phosphatidylcholine or distearoyl L-alpha-phosphatidylcholine. Thus, the type of fatty acid (unsaturated or saturated) in the phospholipid did not influence the assimilation. As the amount of Tween 80 in the growth media increased beyond 0.05%, cholesterol uptake decreased, and the amount of growth remained the same. The higher concentrations of Tween 80 may have adversely affected the permeability of the cells

  1. In silico analyses of dystrophin Dp40 cellular distribution, nuclear export signals and structure modeling

    Directory of Open Access Journals (Sweden)

    Alejandro Martínez-Herrera

    2015-09-01

    Full Text Available Dystrophin Dp40 is the shortest protein encoded by the DMD (Duchenne muscular dystrophy gene. This protein is unique since it lacks the C-terminal end of dystrophins. In this data article, we describe the subcellular localization, nuclear export signals and the three-dimensional structure modeling of putative Dp40 proteins using bioinformatics tools. The Dp40 wild type protein was predicted as a cytoplasmic protein while the Dp40n4 was predicted to be nuclear. Changes L93P and L170P are involved in the nuclear localization of Dp40n4 protein. A close analysis of Dp40 protein scored that amino acids 93LEQEHNNLV101 and 168LLLHDSIQI176 could function as NES sequences and the scores are lost in Dp40n4. In addition, the changes L93/170P modify the tertiary structure of putative Dp40 mutants. The analysis showed that changes of residues 93 and 170 from leucine to proline allow the nuclear localization of Dp40 proteins. The data described here are related to the research article entitled “EF-hand domains are involved in the differential cellular distribution of dystrophin Dp40” (J. Aragón et al. Neurosci. Lett. 600 (2015 115–120 [1].

  2. Synthesis of the oxysterol, 24(S), 25-epoxycholesterol, parallels cholesterol production and may protect against cellular accumulation of newly-synthesized cholesterol

    OpenAIRE

    Brown Andrew J; Quinn Carmel M; Wong Jenny

    2007-01-01

    Abstract Aim The effects of 24(S),25-epoxycholesterol (24,25EC) on aspects of cholesterol homeostasis is well-documented. When added to cells, 24,25EC decreases cholesterol synthesis and up-regulates cholesterol efflux genes, including ABCA1. Synthesis of 24,25EC occurs in a shunt of the mevalonate pathway which also produces cholesterol. Therefore, 24,25EC synthesis should be subject to the same negative feedback regulation as cholesterol synthesis. To date, no role has been ascribed to 24,2...

  3. Glucosylated cholesterol in mammalian cells and tissues: formation and degradation by multiple cellular β-glucosidases.

    Science.gov (United States)

    Marques, André R A; Mirzaian, Mina; Akiyama, Hisako; Wisse, Patrick; Ferraz, Maria J; Gaspar, Paulo; Ghauharali-van der Vlugt, Karen; Meijer, Rianne; Giraldo, Pilar; Alfonso, Pilar; Irún, Pilar; Dahl, Maria; Karlsson, Stefan; Pavlova, Elena V; Cox, Timothy M; Scheij, Saskia; Verhoek, Marri; Ottenhoff, Roelof; van Roomen, Cindy P A A; Pannu, Navraj S; van Eijk, Marco; Dekker, Nick; Boot, Rolf G; Overkleeft, Herman S; Blommaart, Edward; Hirabayashi, Yoshio; Aerts, Johannes M

    2016-03-01

    The membrane lipid glucosylceramide (GlcCer) is continuously formed and degraded. Cells express two GlcCer-degrading β-glucosidases, glucocerebrosidase (GBA) and GBA2, located in and outside the lysosome, respectively. Here we demonstrate that through transglucosylation both GBA and GBA2 are able to catalyze in vitro the transfer of glucosyl-moieties from GlcCer to cholesterol, and vice versa. Furthermore, the natural occurrence of 1-O-cholesteryl-β-D-glucopyranoside (GlcChol) in mouse tissues and human plasma is demonstrated using LC-MS/MS and (13)C6-labeled GlcChol as internal standard. In cells, the inhibition of GBA increases GlcChol, whereas inhibition of GBA2 decreases glucosylated sterol. Similarly, in GBA2-deficient mice, GlcChol is reduced. Depletion of GlcCer by inhibition of GlcCer synthase decreases GlcChol in cells and likewise in plasma of inhibitor-treated Gaucher disease patients. In tissues of mice with Niemann-Pick type C disease, a condition characterized by intralysosomal accumulation of cholesterol, marked elevations in GlcChol occur as well. When lysosomal accumulation of cholesterol is induced in cultured cells, GlcChol is formed via lysosomal GBA. This illustrates that reversible transglucosylation reactions are highly dependent on local availability of suitable acceptors. In conclusion, mammalian tissues contain GlcChol formed by transglucosylation through β-glucosidases using GlcCer as donor. Our findings reveal a novel metabolic function for GlcCer. PMID:26724485

  4. Specific Cellular Incorporation of a Pyrene-Labelled Cholesterol: Lipoprotein-Mediated Delivery toward Ordered Intracellular Membranes

    OpenAIRE

    Gérald Gaibelet; Sophie Allart; François Tercé; Vincent Azalbert; Justine Bertrand-Michel; Safouane Hamdi; Xavier Collet; Stéphane Orlowski

    2015-01-01

    In the aim of testing tools for tracing cell trafficking of exogenous cholesterol, two fluorescent derivatives of cholesterol, 22-nitrobenzoxadiazole-cholesterol (NBD-Chol) and 21-methylpyrenyl-cholesterol (Pyr-met-Chol), with distinctive chemico-physical characteristics, have been compared for their cell incorporation properties, using two cell models differently handling cholesterol, with two incorporation routes. In the Caco-2 cell model, the cholesterol probes were delivered in bile salt ...

  5. Cellular Functions and X-ray Structure of Anthrolysin O, a Cholesterol-dependent Cytolysin Secreted by Bacillus anthracis

    Energy Technology Data Exchange (ETDEWEB)

    Bourdeau, Raymond W.; Malito, Enrico; Chenal, Alexandre; Bishop, Brian L.; Musch, Mark W.; Villereal, Mitch L.; Chang, Eugene B.; Mosser, Elise M.; Rest, Richard F.; Tang, Wei-Jen; (CNRS-UMR); (Drexel-MED); (UC)

    2009-06-02

    Anthrolysin O (ALO) is a pore-forming, cholesterol-dependent cytolysin (CDC) secreted by Bacillus anthracis, the etiologic agent for anthrax. Growing evidence suggests the involvement of ALO in anthrax pathogenesis. Here, we show that the apical application of ALO decreases the barrier function of human polarized epithelial cells as well as increases intracellular calcium and the internalization of the tight junction protein occludin. Using pharmacological agents, we also found that barrier function disruption requires increased intracellular calcium and protein degradation. We also report a crystal structure of the soluble state of ALO. Based on our analytical ultracentrifugation and light scattering studies, ALO exists as a monomer. Our ALO structure provides the molecular basis as to how ALO is locked in a monomeric state, in contrast to other CDCs that undergo antiparallel dimerization or higher order oligomerization in solution. ALO has four domains and is globally similar to perfringolysin O (PFO) and intermedilysin (ILY), yet the highly conserved undecapeptide region in domain 4 (D4) adopts a completely different conformation in all three CDCs. Consistent with the differences within D4 and at the D2-D4 interface, we found that ALO D4 plays a key role in affecting the barrier function of C2BBE cells, whereas PFO domain 4 cannot substitute for this role. Novel structural elements and unique cellular functions of ALO revealed by our studies provide new insight into the molecular basis for the diverse nature of the CDC family.

  6. Specific cellular incorporation of a pyrene-labelled cholesterol: lipoprotein-mediated delivery toward ordered intracellular membranes.

    Directory of Open Access Journals (Sweden)

    Gérald Gaibelet

    Full Text Available In the aim of testing tools for tracing cell trafficking of exogenous cholesterol, two fluorescent derivatives of cholesterol, 22-nitrobenzoxadiazole-cholesterol (NBD-Chol and 21-methylpyrenyl-cholesterol (Pyr-met-Chol, with distinctive chemico-physical characteristics, have been compared for their cell incorporation properties, using two cell models differently handling cholesterol, with two incorporation routes. In the Caco-2 cell model, the cholesterol probes were delivered in bile salt micelles, as a model of intestinal absorption. The two probes displayed contrasting behaviors for cell uptake characteristics, cell staining, and efflux kinetics. In particular, Pyr-met-Chol cell incorporation involved SR-BI, while that of NBD-Chol appeared purely passive. In the PC-3 cell model, which overexpresses lipoprotein receptors, the cholesterol probes were delivered via the serum components, as a model of systemic delivery. We showed that Pyr-met-Chol-labelled purified LDL or HDL were able to specifically deliver Pyr-met-Chol to the PC-3 cells, while NBD-Chol incorporation was independent of lipoproteins. Observations by fluorescence microscopy evidenced that, while NBD-Chol readily stained the cytosolic lipid droplets, Pyr-met-Chol labelling led to the intense staining of intracellular structures of membranous nature, in agreement with the absence of detectable esterification of Pyr-met-Chol. A 48 h incubation of PC-3 cells with either Pyr-met-Chol-labelled LDL or HDL gave same staining patterns, mainly colocalizing with Lamp1, caveolin-1 and CD63. These data indicated convergent trafficking downwards their respective receptors, LDL-R and SR-BI, toward the cholesterol-rich internal membrane compartments, late endosomes and multivesicular bodies. Interestingly, Pyr-met-Chol staining of these structures exhibited a high excimer fluorescence emission, revealing their ordered membrane environment, and indicating that Pyr-met-Chol behaves as a fair

  7. Specific cellular incorporation of a pyrene-labelled cholesterol: lipoprotein-mediated delivery toward ordered intracellular membranes.

    Science.gov (United States)

    Gaibelet, Gérald; Allart, Sophie; Tercé, François; Azalbert, Vincent; Bertrand-Michel, Justine; Hamdi, Safouane; Collet, Xavier; Orlowski, Stéphane

    2015-01-01

    In the aim of testing tools for tracing cell trafficking of exogenous cholesterol, two fluorescent derivatives of cholesterol, 22-nitrobenzoxadiazole-cholesterol (NBD-Chol) and 21-methylpyrenyl-cholesterol (Pyr-met-Chol), with distinctive chemico-physical characteristics, have been compared for their cell incorporation properties, using two cell models differently handling cholesterol, with two incorporation routes. In the Caco-2 cell model, the cholesterol probes were delivered in bile salt micelles, as a model of intestinal absorption. The two probes displayed contrasting behaviors for cell uptake characteristics, cell staining, and efflux kinetics. In particular, Pyr-met-Chol cell incorporation involved SR-BI, while that of NBD-Chol appeared purely passive. In the PC-3 cell model, which overexpresses lipoprotein receptors, the cholesterol probes were delivered via the serum components, as a model of systemic delivery. We showed that Pyr-met-Chol-labelled purified LDL or HDL were able to specifically deliver Pyr-met-Chol to the PC-3 cells, while NBD-Chol incorporation was independent of lipoproteins. Observations by fluorescence microscopy evidenced that, while NBD-Chol readily stained the cytosolic lipid droplets, Pyr-met-Chol labelling led to the intense staining of intracellular structures of membranous nature, in agreement with the absence of detectable esterification of Pyr-met-Chol. A 48 h incubation of PC-3 cells with either Pyr-met-Chol-labelled LDL or HDL gave same staining patterns, mainly colocalizing with Lamp1, caveolin-1 and CD63. These data indicated convergent trafficking downwards their respective receptors, LDL-R and SR-BI, toward the cholesterol-rich internal membrane compartments, late endosomes and multivesicular bodies. Interestingly, Pyr-met-Chol staining of these structures exhibited a high excimer fluorescence emission, revealing their ordered membrane environment, and indicating that Pyr-met-Chol behaves as a fair cholesterol tracer

  8. Inhibition of cellular protein secretion by norwalk virus nonstructural protein p22 requires a mimic of an endoplasmic reticulum export signal.

    Directory of Open Access Journals (Sweden)

    Tyler M Sharp

    Full Text Available Protein trafficking between the endoplasmic reticulum (ER and Golgi apparatus is central to cellular homeostasis. ER export signals are utilized by a subset of proteins to rapidly exit the ER by direct uptake into COPII vesicles for transport to the Golgi. Norwalk virus nonstructural protein p22 contains a YXΦESDG motif that mimics a di-acidic ER export signal in both sequence and function. However, unlike normal ER export signals, the ER export signal mimic of p22 is necessary for apparent inhibition of normal COPII vesicle trafficking, which leads to Golgi disassembly and antagonism of Golgi-dependent cellular protein secretion. This is the first reported function for p22. Disassembly of the Golgi apparatus was also observed in cells replicating Norwalk virus, which may contribute to pathogenesis by interfering with cellular processes that are dependent on an intact secretory pathway. These results indicate that the ER export signal mimic is critical to the antagonistic function of p22, shown herein to be a novel antagonist of ER/Golgi trafficking. This unique and well-conserved human norovirus motif is therefore an appealing target for antiviral drug development.

  9. The cellular RNA export receptor TAP/NXF1 is required for ICP27-mediated export of herpes simplex virus 1 RNA, but the TREX complex adaptor protein Aly/REF appears to be dispensable.

    Science.gov (United States)

    Johnson, Lisa A; Li, Ling; Sandri-Goldin, Rozanne M

    2009-07-01

    Herpes simplex virus 1 (HSV-1) protein ICP27 has been shown to shuttle between the nucleus and cytoplasm and to bind viral RNA during infection. ICP27 was found to interact with the cellular RNA export adaptor protein Aly/REF, which is part of the TREX complex, and to relocalize Aly/REF to viral replication sites. ICP27 is exported to the cytoplasm through the export receptor TAP/NXF1, and ICP27 must be able to interact with TAP/NXF1 for efficient export of HSV-1 early and late transcripts. We examined the dynamics of ICP27 movement and its localization with respect to Aly/REF and TAP/NXF1 in living cells during viral infection. Recombinant viruses with a yellow fluorescent protein (YFP) tag on the N or C terminus of ICP27 were constructed. While the N-terminally tagged ICP27 virus behaved like wild-type HSV-1, the C-terminally tagged virus was defective in viral replication and gene expression, and ICP27 was confined to the nucleus, suggesting that the C-terminal YFP tag interfered with ICP27's C-terminal interactions, including the interaction with TAP/NXF1. To assess the role of Aly/REF and TAP/NXF1 in viral RNA export, these factors were knocked down using small interfering RNA. Knockdown of Aly/REF had little effect on the export of ICP27 or poly(A)(+) RNA during infection. In contrast, a decrease in TAP/NXF1 levels severely impaired export of ICP27 and poly(A)(+) RNA. We conclude that TAP/NXF1 is essential for ICP27-mediated export of RNA during HSV-1 infection, whereas Aly/REF may be dispensable.

  10. Synthesis and validation of novel cholesterol-based fluorescent lipids designed to observe the cellular trafficking of cationic liposomes.

    Science.gov (United States)

    Kim, Bieong-Kil; Seu, Young-Bae; Choi, Jong-Soo; Park, Jong-Won; Doh, Kyung-Oh

    2015-09-15

    Cholesterol-based fluorescent lipids with ether linker were synthesized using NBD (Chol-E-NBD) or Rhodamine B (Chol-E-Rh), and the usefulnesses as fluorescent probes for tracing cholesterol-based liposomes were validated. The fluorescent intensities of liposomes containing these modified lipids were measured and observed under a microscope. Neither compound interfered with the expression of GFP plasmid, and live cell images were obtained without interferences. Changes in the fluorescent intensity of liposomes containing Chol-E-NBD were followed by flow cytometry for up to 24h. These fluorescent lipids could be useful probes for trafficking of cationic liposome-mediated gene delivery. PMID:26243368

  11. Structural basis for the recognition of cellular mRNA export factor REF by herpes viral proteins HSV-1 ICP27 and HVS ORF57.

    Science.gov (United States)

    Tunnicliffe, Richard B; Hautbergue, Guillaume M; Kalra, Priti; Jackson, Brian R; Whitehouse, Adrian; Wilson, Stuart A; Golovanov, Alexander P

    2011-01-06

    The herpesvirus proteins HSV-1 ICP27 and HVS ORF57 promote viral mRNA export by utilizing the cellular mRNA export machinery. This function is triggered by binding to proteins of the transcription-export (TREX) complex, in particular to REF/Aly which directs viral mRNA to the TAP/NFX1 pathway and, subsequently, to the nuclear pore for export to the cytoplasm. Here we have determined the structure of the REF-ICP27 interaction interface at atomic-resolution and provided a detailed comparison of the binding interfaces between ICP27, ORF57 and REF using solution-state NMR. Despite the absence of any obvious sequence similarity, both viral proteins bind on the same site of the folded RRM domain of REF, via short but specific recognition sites. The regions of ICP27 and ORF57 involved in binding by REF have been mapped as residues 104-112 and 103-120, respectively. We have identified the pattern of residues critical for REF/Aly recognition, common to both ICP27 and ORF57. The importance of the key amino acid residues within these binding sites was confirmed by site-directed mutagenesis. The functional significance of the ORF57-REF/Aly interaction was also probed using an ex vivo cytoplasmic viral mRNA accumulation assay and this revealed that mutants that reduce the protein-protein interaction dramatically decrease the ability of ORF57 to mediate the nuclear export of intronless viral mRNA. Together these data precisely map amino acid residues responsible for the direct interactions between viral adaptors and cellular REF/Aly and provide the first molecular details of how herpes viruses access the cellular mRNA export pathway.

  12. 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...

  13. Niemann-pick variant disorders: comparison of errors of cellular cholesterol homeostasis in group D and group C fibroblasts.

    OpenAIRE

    Butler, J D; Comly, M E; Kruth, H. S.; Vanier, M; Filling-Katz, M; Fink, J.; Barton, N.; Weintroub, H; Quirk, J M; Tokoro, T

    1987-01-01

    Fluorescence microscopic examination of filipin-stained cultured skin fibroblasts derived from two brothers with group D Niemann-Pick disease revealed abnormal storage of low density lipoprotein (LDL)-derived cholesterol. LDL stimulation of intracellular cholesteryl ester synthesis was severely compromised in the Niemann-Pick D fibroblasts, as it also was in fibroblasts obtained from Niemann-Pick C patients. Cholesteryl ester synthesis was intermediately deficient in cells derived from an obl...

  14. Antidiabetogenic Effects of Chromium Mitigate Hyperinsulinemia-Induced Cellular Insulin Resistance via Correction of Plasma Membrane Cholesterol Imbalance

    OpenAIRE

    Horvath, Emily M.; Tackett, Lixuan; McCarthy, Alicia M.; Raman, Priya; Brozinick, Joseph T.; Elmendorf, Jeffrey S.

    2007-01-01

    Previously, we found that a loss of plasma membrane (PM) phosphatidylinositol 4,5-bisphosphate (PIP2)-regulated filamentous actin (F-actin) structure contributes to insulin-induced insulin resistance. Interestingly, we also demonstrated that chromium picolinate (CrPic), a dietary supplement thought to improve glycemic status in insulin-resistant individuals, augments insulin-regulated glucose transport in insulin-sensitive 3T3-L1 adipocytes by lowering PM cholesterol. Here, to gain mechanisti...

  15. Construction of a novel cationic polymeric liposomes formed from PEGlated octadecyl-quaternized lysine modified chitosan/cholesterol for enhancing storage stability and cellular uptake efficiency.

    Science.gov (United States)

    Wang, Hanjie; Zhao, Peiqi; Liang, Xiaofei; Song, Tao; Gong, Xiaoqun; Niu, Ruifang; Chang, Jin

    2010-08-15

    The design and construction of delivery vectors with high stability and effective cellular uptake efficiency is very important. In this study, a novel polymeric liposomes (PLs) formed from PEGlated octadecyl-quaternized lysine modified chitosan (OQLCS) and cholesterol with higher size stability and cellular uptake efficiency has been synthesized successfully. Compared to conventional liposomes (CLs; phosphatidyl choline/cholesterol), the calcein-loaded PLs exhibited a multi-lamellar structure with homogenous size diameter (200 nm) and high calcein encapsulation efficiency (about 92%). PLs could be stored at different temperature (25, 4, and -20 degrees C) and different medium (deionized water, phosphate-buffered saline, and human plasma solution) for up to 4 weeks without significant size change. The spectrophotometer fluorometry analysis and the flow cytometry analysis indicated that in comparison with CL, PLs with positive zeta potential facilitates the uptake of calcein by MCF-7 tumor cells. The data suggests that PLs may provide a new method to overcome the stability and enhance the uptake efficiency of CLs. PMID:20506161

  16. 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

  17. 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.

  18. 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- ...

  19. Binding of cellular export factor REF/Aly by Kaposi's sarcoma-associated herpesvirus (KSHV) ORF57 protein is not required for efficient KSHV lytic replication.

    Science.gov (United States)

    Li, Da-Jiang; Verma, Dinesh; Swaminathan, Sankar

    2012-09-01

    Kaposi's sarcoma-associated herpesvirus (KSHV) ORF57 protein is expressed early during lytic KSHV replication, enhances expression of many KSHV genes, and is essential for virus production. ORF57 is a member of a family of proteins conserved among all human and many animal herpesviruses that are multifunctional regulators of gene expression and act posttranscriptionally to increase accumulation of their target mRNAs. The mechanism of ORF57 action is complex and may involve effects on mRNA transcription, stability, and export. ORF57 directly binds to REF/Aly, a cellular RNA-binding protein component of the TREX complex that mediates RNA transcription and export. We analyzed the effects of an ORF57 mutation known to abrogate REF/Aly binding and demonstrate that the REF-binding mutant is impaired in activation of viral mRNAs and noncoding RNAs confined to the nucleus. Although the inability to bind REF leads to decreased ORF57 activity in enhancing gene expression, there is no demonstrable effect on nuclear export of viral mRNA or the ability of ORF57 to support KSHV replication and virus production. These data indicate that REF/Aly-ORF57 interaction is not essential for KSHV lytic replication but may contribute to target RNA stability independent of effects on RNA export, suggesting a novel role for REF/Aly in viral RNA metabolism.

  20. Cellular uptake mechanism and comparative evaluation of antineoplastic effects of paclitaxel–cholesterol lipid emulsion on triple-negative and non-triple-negative breast cancer cell lines

    Science.gov (United States)

    Ye, Jun; Xia, Xuejun; Dong, Wujun; Hao, Huazhen; Meng, Luhua; Yang, Yanfang; Wang, Renyun; Lyu, Yuanfeng; Liu, Yuling

    2016-01-01

    There is no effective clinical therapy for triple-negative breast cancers (TNBCs), which have high low-density lipoprotein (LDL) requirements and express relatively high levels of LDL receptors (LDLRs) on their membranes. In our previous study, a novel lipid emulsion based on a paclitaxel–cholesterol complex (PTX-CH Emul) was developed, which exhibited improved safety and efficacy for the treatment of TNBC. To date, however, the cellular uptake mechanism and intracellular trafficking of PTX-CH Emul have not been investigated. In order to offer powerful proof for the therapeutic effects of PTX-CH Emul, we systematically studied the cellular uptake mechanism and intracellular trafficking of PTX-CH Emul and made a comparative evaluation of antineoplastic effects on TNBC (MDA-MB-231) and non-TNBC (MCF7) cell lines through in vitro and in vivo experiments. The in vitro antineoplastic effects and in vivo tumor-targeting efficiency of PTX-CH Emul were significantly more enhanced in MDA-MB-231-based models than those in MCF7-based models, which was associated with the more abundant expression profile of LDLR in MDA-MB-231 cells. The results of the cellular uptake mechanism indicated that PTX-CH Emul was internalized into breast cancer cells through the LDLR-mediated internalization pathway via clathrin-coated pits, localized in lysosomes, and then released into the cytoplasm, which was consistent with the internalization pathway and intracellular trafficking of native LDL. The findings of this paper further confirm the therapeutic potential of PTX-CH Emul in clinical applications involving TNBC therapy. PMID:27601899

  1. Cellular uptake mechanism and comparative evaluation of antineoplastic effects of paclitaxel-cholesterol lipid emulsion on triple-negative and non-triple-negative breast cancer cell lines.

    Science.gov (United States)

    Ye, Jun; Xia, Xuejun; Dong, Wujun; Hao, Huazhen; Meng, Luhua; Yang, Yanfang; Wang, Renyun; Lyu, Yuanfeng; Liu, Yuling

    2016-01-01

    There is no effective clinical therapy for triple-negative breast cancers (TNBCs), which have high low-density lipoprotein (LDL) requirements and express relatively high levels of LDL receptors (LDLRs) on their membranes. In our previous study, a novel lipid emulsion based on a paclitaxel-cholesterol complex (PTX-CH Emul) was developed, which exhibited improved safety and efficacy for the treatment of TNBC. To date, however, the cellular uptake mechanism and intracellular trafficking of PTX-CH Emul have not been investigated. In order to offer powerful proof for the therapeutic effects of PTX-CH Emul, we systematically studied the cellular uptake mechanism and intracellular trafficking of PTX-CH Emul and made a comparative evaluation of antineoplastic effects on TNBC (MDA-MB-231) and non-TNBC (MCF7) cell lines through in vitro and in vivo experiments. The in vitro antineoplastic effects and in vivo tumor-targeting efficiency of PTX-CH Emul were significantly more enhanced in MDA-MB-231-based models than those in MCF7-based models, which was associated with the more abundant expression profile of LDLR in MDA-MB-231 cells. The results of the cellular uptake mechanism indicated that PTX-CH Emul was internalized into breast cancer cells through the LDLR-mediated internalization pathway via clathrin-coated pits, localized in lysosomes, and then released into the cytoplasm, which was consistent with the internalization pathway and intracellular trafficking of native LDL. The findings of this paper further confirm the therapeutic potential of PTX-CH Emul in clinical applications involving TNBC therapy. PMID:27601899

  2. 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 ...

  3. A low-saturated-fat, low-cholesterol diet decreases plasma CETP activity and pre beta-HDL formation but does not affect cellular cholesterol efflux to plasma from type 1 diabetic patients

    NARCIS (Netherlands)

    De Vries, R; Beusekamp, BJ; Kerstens, MN; Groen, AK; Van Tol, A; Dullaart, RPF

    2005-01-01

    The aim of this study was to evaluate the effect of a low-saturated-fat, low-cholesterol diet on plasma lipopoproteins, pre beta-high density lipoprotein (HDL) formation, lecithin: cholesterol acyltransferase (LCAT), cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP)

  4. Nuclear Factor 90, a cellular dsRNA binding protein inhibits the HIV Rev-export function

    Directory of Open Access Journals (Sweden)

    St-Laurent Georges

    2006-11-01

    Full Text Available Abstract Background The HIV Rev protein is known to facilitate export of incompletely spliced and unspliced viral transcripts to the cytoplasm, a necessary step in virus life cycle. The Rev-mediated nucleo-cytoplasmic transport of nascent viral transcripts, dependents on interaction of Rev with the RRE RNA structural element present in the target RNAs. The C-terminal variant of dsRNA-binding nuclear protein 90 (NF90ctv has been shown to markedly attenuate viral replication in stably transduced HIV-1 target cell line. Here we examined a mechanism of interference of viral life cycle involving Rev-NF90ctv interaction. Results Since Rev:RRE complex formations depend on protein:RNA and protein:protein interactions, we investigated whether the expression of NF90ctv might interfere with Rev-mediated export of RRE-containing transcripts. When HeLa cells expressed both NF90ctv and Rev protein, we observed that NF90ctv inhibited the Rev-mediated RNA transport. In particular, three regions of NF90ctv protein are involved in blocking Rev function. Moreover, interaction of NF90ctv with the RRE RNA resulted in the expression of a reporter protein coding sequences linked to the RRE structure. Moreover, Rev influenced the subcellular localization of NF90ctv, and this process is leptomycin B sensitive. Conclusion The dsRNA binding protein, NF90ctv competes with HIV Rev function at two levels, by competitive protein:protein interaction involving Rev binding to specific domains of NF90ctv, as well as by its binding to the RRE-RNA structure. Our results are consistent with a model of Rev-mediated HIV-1 RNA export that envisions Rev-multimerization, a process interrupted by NF90ctv.

  5. 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 ...

  6. Cholesterol Regulates Syntaxin 6 Trafficking at trans-Golgi Network Endosomal Boundaries

    Directory of Open Access Journals (Sweden)

    Meritxell Reverter

    2014-05-01

    Full Text Available Inhibition of cholesterol export from late endosomes causes cellular cholesterol imbalance, including cholesterol depletion in the trans-Golgi network (TGN. Here, using Chinese hamster ovary (CHO Niemann-Pick type C1 (NPC1 mutant cell lines and human NPC1 mutant fibroblasts, we show that altered cholesterol levels at the TGN/endosome boundaries trigger Syntaxin 6 (Stx6 accumulation into VAMP3, transferrin, and Rab11-positive recycling endosomes (REs. This increases Stx6/VAMP3 interaction and interferes with the recycling of αVβ3 and α5β1 integrins and cell migration, possibly in a Stx6-dependent manner. In NPC1 mutant cells, restoration of cholesterol levels in the TGN, but not inhibition of VAMP3, restores the steady-state localization of Stx6 in the TGN. Furthermore, elevation of RE cholesterol is associated with increased amounts of Stx6 in RE. Hence, the fine-tuning of cholesterol levels at the TGN-RE boundaries together with a subset of cholesterol-sensitive SNARE proteins may play a regulatory role in cell migration and invasion.

  7. 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 ...

  8. 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...

  9. 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.

  10. Nuclear export of human hepatitis B virus core protein and pregenomic RNA depends on the cellular NXF1-p15 machinery.

    Science.gov (United States)

    Yang, Ching-Chun; Huang, Er-Yi; Li, Hung-Cheng; Su, Pei-Yi; Shih, Chiaho

    2014-01-01

    Hepatitis B virus (HBV) core protein (HBc) can shuttle between nucleus and cytoplasm. Cytoplasm-predominant HBc is clinically associated with severe liver inflammation. Previously, we found that HBc arginine-rich domain (ARD) can associate with a host factor NXF1 (TAP) by coimmunoprecipitation. It is well known that NXF1-p15 heterodimer can serve as a major export receptor of nuclear mRNA as a ribonucleoprotein complex (RNP). In the NXF1-p15 pathway, TREX (transcription/export) complex plays an important role in coupling nuclear pre-mRNA processing with mRNA export in mammalian cells. Here, we tested the hypothesis whether HBc and HBV specific RNA can be exported via the TREX and NXF1-p15 mediated pathway. We demonstrated here that HBc can physically and specifically associate with TREX components, and the NXF1-p15 export receptor by coimmunoprecipitation. Accumulation of HBc protein in the nucleus can be induced by the interference with TREX and NXF1-p15 mediated RNA export machinery. HBV transcripts encodes a non-spliced 3.5 kb pregenomic RNA (pgRNA) which can serve as a template for reverse transcription. Cytoplasmic HBV pgRNA appeared to be reduced by siRNA treatment specific for the NXF1-p15 complex by quantitative RT-qPCR and Northern blot analyses. This result suggests that the pgRNA was also exported via the NXF1-p15 machinery. We entertain the hypothesis that HBc protein can be exported as an RNP cargo via the mRNA export pathway by hijacking the TREX and NXF1-p15 complex. In our current and previous studies, HBc is not required for pgRNA accumulation in the cytoplasm. Furthermore, HBc ARD can mediate nuclear export of a chimeric protein containing HBc ARD in a pgRNA-independent manner. Taken together, it suggests that while both pgRNA and HBc protein exports are dependent on NXF1-p15, they are using the same export machinery in a manner independent of each other.

  11. 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

  12. 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 ...

  13. 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 ...

  14. 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 ...

  15. 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 ...

  16. 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 ; ...

  17. 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 ; ...

  18. 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 ...

  19. 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.

  20. 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...

  1. Deficiency in the Lipid Exporter ABCA1 Impairs Retrograde Sterol Movement and Disrupts Sterol Sensing at the Endoplasmic Reticulum.

    Science.gov (United States)

    Yamauchi, Yoshio; Iwamoto, Noriyuki; Rogers, Maximillian A; Abe-Dohmae, Sumiko; Fujimoto, Toyoshi; Chang, Catherine C Y; Ishigami, Masato; Kishimoto, Takuma; Kobayashi, Toshihide; Ueda, Kazumitsu; Furukawa, Koichi; Chang, Ta-Yuan; Yokoyama, Shinji

    2015-09-25

    Cellular cholesterol homeostasis involves sterol sensing at the endoplasmic reticulum (ER) and sterol export from the plasma membrane (PM). Sterol sensing at the ER requires efficient sterol delivery from the PM; however, the macromolecules that facilitate retrograde sterol transport at the PM have not been identified. ATP-binding cassette transporter A1 (ABCA1) mediates cholesterol and phospholipid export to apolipoprotein A-I for the assembly of high density lipoprotein (HDL). Mutations in ABCA1 cause Tangier disease, a familial HDL deficiency. Several lines of clinical and experimental evidence suggest a second function of ABCA1 in cellular cholesterol homeostasis in addition to mediating cholesterol efflux. Here, we report the unexpected finding that ABCA1 also plays a key role in facilitating retrograde sterol transport from the PM to the ER for sterol sensing. Deficiency in ABCA1 delays sterol esterification at the ER and activates the SREBP-2 cleavage pathway. The intrinsic ATPase activity in ABCA1 is required to facilitate retrograde sterol transport. ABCA1 deficiency causes alternation of PM composition and hampers a clathrin-independent endocytic activity that is required for ER sterol sensing. Our finding identifies ABCA1 as a key macromolecule facilitating bidirectional sterol movement at the PM and shows that ABCA1 controls retrograde sterol transport by modulating a certain clathrin-independent endocytic process.

  2. Export spillovers

    DEFF Research Database (Denmark)

    Choquette, Eliane; Meinen, Philipp

    2015-01-01

    This paper studies the importance of export spillovers in a firm's decision to enter specific export markets and extends the current state of the literature by assessing different mechanisms through which they may occur, namely (i) labour movement, (ii) intra-industry spillovers and (iii) inter...... of different size and export markets....

  3. 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

  4. 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

  5. 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- ...

  6. 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.

  7. 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 ...

  8. 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 ...

  9. 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 ( ...

  10. 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

  11. 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.

  12. 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.

  13. 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...

  14. Export strategy

    DEFF Research Database (Denmark)

    Knudsen, Thorbjørn; Koed Madsen, Tage

    2002-01-01

    It is argued here that traditional export strategy research (encompassing the study of internationalization processes and export performance) is characterized by weak theoretical foundations and could benefit from a reorientation towards a dynamic capabilities perspective (DCP). We seek to draw...... on insights from DCP in order to devise a theoretical basis that could enrich export strategy research. Although our development of DCP insights builds on previous work, it also adds a crucial distinction between knowledge stocks and informational architecture. Changes in architecture are of greater...

  15. Molecular View of Cholesterol Flip-Flop and Chemical Potential in Different Membrane Environments

    NARCIS (Netherlands)

    Bennett, W. F. Drew; MacCallum, Justin L.; Hinner, Marlon J.; Marrink, Siewert J.; Tieleman, D. Peter

    2009-01-01

    The relative stability of cholesterol in cellular membranes and the thermodynamics of fluctuations from equilibrium have important consequences for sterol trafficking and lateral domain formation. We used molecular dynamics computer simulations to investigate the partitioning of cholesterol in a sys

  16. 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.

  17. 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

  18. The nuclear-cytoplasmic shuttling of virion host shutoff RNase is enabled by pUL47 and an embedded nuclear export signal and defines the sites of degradation of AU-rich and stable cellular mRNAs.

    Science.gov (United States)

    Shu, Minfeng; Taddeo, Brunella; Roizman, Bernard

    2013-12-01

    The herpes simplex virus host shutoff RNase (VHS-RNase) is the major early block of host responses to infection. VHS-RNase is introduced into cells during infection and selectively degrades stable mRNAs made before infection and the normally short-lived AU-rich stress response mRNAs induced by sensors of innate immunity. Through its interactions with pUL47, another tegument protein, it spares from degradation viral mRNAs. Analyses of embedded motifs revealed that VHS-RNase contains a nuclear export signal (NES) but not a nuclear localization signal. To reconcile the potential nuclear localization with earlier studies showing that VHS-RNase degrades mRNAs in polyribosomes, we constructed a mutant in which NES was ablated. Comparison of the mutant and wild-type VHS-RNases revealed the following. (i) On infection, VHS-RNase is transported to the nucleus, but only the wild-type protein shuttles between the nucleus and cytoplasm. (ii) Both VHS-RNases localized in the cytoplasm following transfection. On cotransfection with pUL47, a fraction of VHS-RNase was translocated to the nucleus, suggesting that pUL47 may enable nuclear localization of VHS-RNase. (iii) In infected cells, VHS-RNase lacking NES degraded the short-lived AU-rich mRNAs but not the stable mRNAs. In transfected cells, both wild-type and NES mutant VHS-RNases effectively degraded cellular mRNAs. Our results suggest that the stable mRNAs are degraded in the cytoplasm, whereas the AU-rich mRNAs may be degraded in both cellular compartments. The selective sparing of viral mRNAs may take place during the nuclear phase in the course of interaction of pUL47, VHS-RNase, and nascent viral mRNAs.

  19. 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 ...

  20. 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, ...

  1. 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 ...

  2. 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) ...

  3. 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

  4. 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

  5. Antagonism of betulinic acid on LPS-mediated inhibition of ABCA1 and cholesterol efflux through inhibiting nuclear factor-kappaB signaling pathway and miR-33 expression.

    Science.gov (United States)

    Zhao, Guo-Jun; Tang, Shi-Lin; Lv, Yun-Cheng; Ouyang, Xin-Ping; He, Ping-Ping; Yao, Feng; Chen, Wu-Jun; Lu, Qian; Tang, Yan-Yan; Zhang, Min; Fu, Yuchang; Zhang, Da-Wei; Yin, Kai; Tang, Chao-Ke

    2013-01-01

    ATP-binding cassette transporter A1 (ABCA1) is critical in exporting cholesterol from macrophages and plays a protective role in the development of atherosclerosis. The purpose of this study was to investigate the effects of betulinic acid (BA), a pentacyclic triterpenoid, on ABCA1 expression and cholesterol efflux, and to further determine the underlying mechanism. BA promoted ABCA1 expression and cholesterol efflux, decreased cellular cholesterol and cholesterol ester content in LPS-treated macrophages. Furthermore, we found that BA promoted ABCA1 expression via down-regulation of miR-33s. The inhibition of LPS-induced NF-κB activation further decreased miR-33s expression and enhanced ABCA1 expression and cholesterol efflux when compared with BA only treatment. In addition, BA suppressed IκB phosphorylation, p65 phosphorylation and nuclear translocation, and the transcription of NF-κB-dependent related gene. Moreover, BA reduced atherosclerotic lesion size, miR-33s levels and NF-κB activation, and promoted ABCA1 expression in apoE(-/-) mice. Taken together, these results reveal a novel mechanism for the BA-mediated ABCA1 expression, which may provide new insights for developing strategies for modulating vascular inflammation and atherosclerosis. PMID:24086374

  6. Antagonism of betulinic acid on LPS-mediated inhibition of ABCA1 and cholesterol efflux through inhibiting nuclear factor-kappaB signaling pathway and miR-33 expression.

    Directory of Open Access Journals (Sweden)

    Guo-Jun Zhao

    Full Text Available ATP-binding cassette transporter A1 (ABCA1 is critical in exporting cholesterol from macrophages and plays a protective role in the development of atherosclerosis. The purpose of this study was to investigate the effects of betulinic acid (BA, a pentacyclic triterpenoid, on ABCA1 expression and cholesterol efflux, and to further determine the underlying mechanism. BA promoted ABCA1 expression and cholesterol efflux, decreased cellular cholesterol and cholesterol ester content in LPS-treated macrophages. Furthermore, we found that BA promoted ABCA1 expression via down-regulation of miR-33s. The inhibition of LPS-induced NF-κB activation further decreased miR-33s expression and enhanced ABCA1 expression and cholesterol efflux when compared with BA only treatment. In addition, BA suppressed IκB phosphorylation, p65 phosphorylation and nuclear translocation, and the transcription of NF-κB-dependent related gene. Moreover, BA reduced atherosclerotic lesion size, miR-33s levels and NF-κB activation, and promoted ABCA1 expression in apoE(-/- mice. Taken together, these results reveal a novel mechanism for the BA-mediated ABCA1 expression, which may provide new insights for developing strategies for modulating vascular inflammation and atherosclerosis.

  7. Cholesterol Accumulation Sequesters Rab9 and Disrupts Late Endosome Function in NPC1-deficient Cells*

    OpenAIRE

    Ganley, Ian G.; Pfeffer, Suzanne R

    2006-01-01

    Niemann-Pick type C disease is an autosomal recessive disorder that leads to massive accumulation of cholesterol and glycosphingolipids in late endosomes and lysosomes. To understand how cholesterol accumulation influences late endosome function, we investigated the effect of elevated cholesterol on Rab9-dependent export of mannose 6-phosphate receptors from this compartment. Endogenous Rab9 levels were elevated 1.8-fold in Niemann-Pick type C cells relative to wild type cells, and its half-l...

  8. 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.

  9. 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.

  10. 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 ...

  11. 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 ...

  12. US exports

    International Nuclear Information System (INIS)

    This paper reports on the past, present, and future of US coal exports. It is expected that in the 1990's, the following factors will be evident: Significant increases in coal production and port capacity in Australia and South Africa, but little in Canada; Potentially significant increase in coal production and port capacity in Colombia, Venezuela and Indonesia; Continued movement away from subsidized indigenous coal production in Europe and Japan. A substantial growth in world coal trade; Stronger growth in energy demand in the 1990s than in the 1980s; Significantly fewer additions to nuclear generating capacity in the 1990s than in the 1980s; Reduced coal production in Eastern Europe from that of the 1980s; Greater caution will be exercised in putting in new coal production capacity

  13. 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

  14. 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 ...

  15. Demand Uncertainty: Exporting Delays and Exporting Failures

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen

    2012-01-01

    This paper presents a model of trade that explains why firms wait to export and why many exporters fail. Firms face uncertain demands that are only realized after the firm enters the destination. The model retools the timing of the resolution of uncertainty found in models with heterogeneity....... This prediction reconciles the high rate of exit seen in the first years of exporting. Finally, when faced with multiple destinations to which they can export, many firms will choose to sequentially export in order to slowly learn more about its chances for success in untested markets....

  16. 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).

  17. The liver X receptor : Control of cellular lipid homeostasis and beyond Implications for drug design

    NARCIS (Netherlands)

    Oosterveer, Maaike H.; Grefhorst, Aldo; Groen, Albert K.; Kuipers, Folkert

    2010-01-01

    Liver X receptor (LXR) alpha and beta are nuclear receptors that control cellular metabolism. LXRs modulate the expression of genes involved in cholesterol and lipid metabolism in response to changes in cellular cholesterol status. Because of their involvement in cholesterol homeostasis, LXRs have e

  18. 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

  19. 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

  20. Cholesterol transfer from normal and atherogenic low density lipoproteins to Mycoplasma membranes

    International Nuclear Information System (INIS)

    The purpose of this study was to determine whether the free cholesterol of hypercholesterolemic low density lipoprotein from cholesterol-fed nonhuman primates has a greater potential for surface transfer to cell membranes than does the free cholesterol of normal low density lipoprotein. The low density lipoproteins were isolated from normal and hypercholesterolemic rhesus and cynomolgus monkeys, incubated with membranes from Acholeplasma laidlawii, a mycoplasma species devoid of cholesterol in its membranes, and the mass transfer of free cholesterol determined by measuring membrane cholesterol content. Since these membranes neither synthesize nor esterify cholesterol, nor degrade the protein or cholesterol ester moieties of low density lipoprotein, they are an ideal model with which to study differences in the cholesterol transfer potential of low density lipoprotein independent of the uptake of the intact low density lipoprotein particle. These studies indicate that, even though there are marked differences in the cholesterol composition of normal and hypercholesterolemic low density lipoproteins, this does not result in a greater chemical potential for surface transfer of free cholesterol. Consequently, if a difference in the surface transfer of free cholesterol is responsible for the enhanced ability of hypercholesterolemic low density lipoprotein to promote cellular cholesterol accumulation and, perhaps, also atherosclerosis, it must be the result of differences in the interaction to the hypercholesterolemic low density lipoprotein with the more complicated mammalian cell membranes, rather than differences in the chemical potential for cholesterol transfer

  1. 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...

  2. Protein complexes and cholesterol in the control of late endosomal dynamicsCholesterol and multi-protein complexes in the control of late endosomal dynamics

    NARCIS (Netherlands)

    Kant, Rik Henricus Nicolaas van der

    2013-01-01

    Late endosomal transport is disrupted in several diseases such as Niemann-Pick type C, ARC syndrome and Alzheimer’s disease. This thesis describes the regulation of late endosomal dynamics by cholesterol and multi-protein complexes. We find that cholesterol acts as a cellular tomtom that steers the

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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 ...

  8. Markups and Exporting Behavior

    DEFF Research Database (Denmark)

    De Loecker, Jan; Warzynski, Frederic Michel Patrick

    2012-01-01

    estimates of plant- level markups without specifying how firms compete in the product market. We rely on our method to explore the relationship be- tween markups and export behavior. We find that markups are estimated significantly higher when controlling for unobserved productivity; that exporters charge......, on average, higher markups and that markups increase upon export entry....

  9. 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.

  10. 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 ...

  11. Learning by Exporting

    DEFF Research Database (Denmark)

    Cruz, Antonio; Newman, Carol; Rand, John;

    2016-01-01

    In this article, we analyse the learning-by-exporting (LBE) hypothesis in the Mozambican context. Due to the presence of the ‘Born-Global’ phenomenon among exporters, we address the endogeneity introduced by self-selection, combining a generalised Blinder–Oaxaca approach with results from...... traditional matching techniques. Our results show that very few manufacturing firms export, and that export participation is highly persistent. There is also evidence supporting the LBE hypothesis and the results suggest a significant export premium of between 17 and 21%, controlling for differences...

  12. 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.

  13. Local Export spillovers in France

    OpenAIRE

    Koenig, Pamina; Mayneris, Florian; Poncet, Sandra

    2010-01-01

    International audience; This paper investigates the presence of local export spillovers on both the extensive (the decision to start exporting) and the intensive (the export volume) margins of trade, using data on French individual export flows, at the product-level and by destination country, between 1998 and 2003. We investigate whether the individual decision to start exporting and exported volume are influenced by the presence of nearby product and/or destination specific exporters, using...

  14. 豚鼠胆囊胆固醇结石形成过程中肠道传输功能下降的细胞及分子机制探讨%Cellular and molecular mechanism of slow intestinal transit during formation of cholesterol gallstones in guinea pig model

    Institute of Scientific and Technical Information of China (English)

    范莹; 吴硕东; 殷振华; 付倍蓓

    2013-01-01

    目的 探讨豚鼠胆囊胆固醇结石形成过程中肠道传输功能下降的细胞和分子机制及其与胆石形成的关系.方法 健康雄性豚鼠40只,4周龄,体质量120~ 125 g.将其随机分为实验组与对照组,每组20只.实验组给予致石饲料(胆固醇含量2%),对照组给予正常颗粒饲料.8周造模结束后,用逆转录聚合酶链反应(RT-PCR)检测小肠组织中c-kit及scf的mRNA的表达情况,利用末端回肠全层铺片免疫荧光化学染色及激光共聚焦显微镜观察各组Cajal样间质细胞(ICCs)数量的变化.结果 RT-PCR结果显示,与对照组相比,实验组豚鼠小肠c-kit(0.316±0.056 vs 0.912±0.103;t=6.582,P<0.01)和scf(0.499±0.012 vs 0.899±0.124;t=6.163,P<0.01)的mRNA水平的表达量下降;对照组豚鼠回肠ICCs平均阳性面积为(56.24±2.68)%,实验组为(22.26±1.14)%,较对照组明显降低(t=15.256,P<0.01).结论 饮食诱导的豚鼠胆囊胆固醇结石形成过程中,小肠c-kit和scf基因mRNA表达水平下降,ICCs数量明显减少.c-kit/scf通路抑制可能参与胆囊胆固醇结石的形成过程中肠道传输功能下降的发生.%Objective To investigate the cellular and molecular mechanism of slow intestinal transit during the formation of cholesterol gallstones in guinea pig model, and study its relationship with gallstone formation. Methods Forty healthy male guinea pigs of 4-week old and 120 - 150 g body weight were randomly divided into 2 groups, namely experimental group and control group(n= 20). The experimental group was fed high cholesterol diet (cholesterol 2 %), and control group fed normal diet. The guinea pigs were sacrificed after 8 weeks. Reverse transcription polymerase chain reaction(RT-PCR) was used to determine the expression of c-kit and scf mRNA. Change in the numbers of interstitial Cajal cells(ICCs) in terminal ileum was observed by immunohistochemical method. Results Compared with the control group, the mRNA expression of c-kit(0

  15. 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

  16. Export destinations and learning-by-exporting : Evidence from Belgium

    OpenAIRE

    Mauro Pisu

    2008-01-01

    This paper evaluates the causal effects of exports to different destination countries using a comprehensive dataset on Belgian manufacturing firms from 1998 to 2005. Initial evidence suggests that, before export market entry, exporters to more developed economies have superior productivity levels than non-exporters and firms exporting to less developed countries. Moreover, they seem to experience higher productivity growth rates in the post-entry period, suggesting learning-by-exporting effec...

  17. Export destinations and learning-by-exporting: Evidence from Belgium

    OpenAIRE

    Pisu, Mauro

    2008-01-01

    This paper evaluates the causal effects of exports to different destination countries using a comprehensive dataset on Belgian manufacturing firms from 1998 to 2005. Initial evidence suggests that, before export market entry, exporters to more developed economies have superior productivity levels than non-exporters and firms exporting to less developed countries. Moreover, they seem to experience higher productivity growth rates in the post-entry period, suggesting learning-by-exporting effec...

  18. 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.

  19. Export Diversification in Africa

    OpenAIRE

    Huria, Ankur; Brenton, Paul

    2015-01-01

    Economic activity in many African countries remains highly concentrated and exports are often dominated by mineral resources or a few primary products. The World Bank’s 2011 report on light manufacturing in Africa identified poor trade logistics performance as a constraint that especially penalized African exporters that relied on imported inputs, very often making them uncompetitive. The ...

  20. Developing Refractories for Exporting

    Institute of Scientific and Technical Information of China (English)

    PANShang-xin

    1996-01-01

    The total output of China refractory products and export volume of China refractory raw materials rank the first in the world,In future the task is to improve the quality of the products to enlarge the variety and to expand export.

  1. Exports to Imports

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China covers ground as it attempts to balance imports and exports after a trade deficit in the first quarter As China gears up to rebalance its economy,a key factor will be weaning its reliance on exports.The vigorous efforts are paying off as the country reported a trade deficit in the first

  2. Strong Support for Exporters

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ The sweeping international financial crisis has taken its toll on the Chinese economy,especially in the export sector.On the one hand,overseas demand has plummeted,while on the other,with the worsening credit environment and emerging trade protectionism,export enterprises are suffering from rising credit risks to the point where some dare not even accept orders.

  3. 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.

  4. Up-regulation of cholesterol associated genes as novel resistance mechanism in glioblastoma cells in response to archazolid B

    Energy Technology Data Exchange (ETDEWEB)

    Hamm, Rebecca; Zeino, Maen [Institute of Pharmacy and Biochemistry, Department of Pharmaceutical Biology, Johannes Gutenberg University, Staudinger Weg 5, 55128 Mainz (Germany); Frewert, Simon [Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Saarbrücken (Germany); Efferth, Thomas, E-mail: efferth@uni-mainz.de [Institute of Pharmacy and Biochemistry, Department of Pharmaceutical Biology, Johannes Gutenberg University, Staudinger Weg 5, 55128 Mainz (Germany)

    2014-11-15

    Treatment of glioblastoma multiforme (GBM), the most common and aggressive lethal brain tumor, represents a great challenge. Despite decades of research, the survival prognosis of GBM patients is unfavorable and more effective therapeutics are sorely required. Archazolid B, a potent vacuolar H{sup +}-ATPase inhibitor influencing cellular pH values, is a promising new compound exerting cytotoxicity in the nanomolar range on wild-type U87MG glioblastoma cells and U87MG.∆EGFR cells transfected with a mutant epidermal growth factor receptor (EGFR) gene. Gene expression profiling using microarray technology showed that archazolid B caused drastic disturbances in cholesterol homeostasis. Cholesterol, a main component of cellular membranes, is known to be essential for GBM growth and cells bearing EGFRvIII mutation are highly dependent on exogenous cholesterol. Archazolid B caused excessive accumulation of free cholesterol within intracellular compartments thus depleting cellular cholesterol and leading to up-regulation of SREBP targeted genes, including LDLR and HMGCR, the key enzyme of cholesterol biosynthesis. This cholesterol response is considered to be a novel resistance mechanism induced by archazolid B. We surmise that re-elevation of cholesterol levels in archazolid B treated cells may be mediated by newly synthesized cholesterol, since the drug leads to endosomal/lysosomal malfunction and cholesterol accumulation.

  5. Up-regulation of cholesterol associated genes as novel resistance mechanism in glioblastoma cells in response to archazolid B

    International Nuclear Information System (INIS)

    Treatment of glioblastoma multiforme (GBM), the most common and aggressive lethal brain tumor, represents a great challenge. Despite decades of research, the survival prognosis of GBM patients is unfavorable and more effective therapeutics are sorely required. Archazolid B, a potent vacuolar H+-ATPase inhibitor influencing cellular pH values, is a promising new compound exerting cytotoxicity in the nanomolar range on wild-type U87MG glioblastoma cells and U87MG.∆EGFR cells transfected with a mutant epidermal growth factor receptor (EGFR) gene. Gene expression profiling using microarray technology showed that archazolid B caused drastic disturbances in cholesterol homeostasis. Cholesterol, a main component of cellular membranes, is known to be essential for GBM growth and cells bearing EGFRvIII mutation are highly dependent on exogenous cholesterol. Archazolid B caused excessive accumulation of free cholesterol within intracellular compartments thus depleting cellular cholesterol and leading to up-regulation of SREBP targeted genes, including LDLR and HMGCR, the key enzyme of cholesterol biosynthesis. This cholesterol response is considered to be a novel resistance mechanism induced by archazolid B. We surmise that re-elevation of cholesterol levels in archazolid B treated cells may be mediated by newly synthesized cholesterol, since the drug leads to endosomal/lysosomal malfunction and cholesterol accumulation

  6. Cellular automata

    CERN Document Server

    Codd, E F

    1968-01-01

    Cellular Automata presents the fundamental principles of homogeneous cellular systems. This book discusses the possibility of biochemical computers with self-reproducing capability.Organized into eight chapters, this book begins with an overview of some theorems dealing with conditions under which universal computation and construction can be exhibited in cellular spaces. This text then presents a design for a machine embedded in a cellular space or a machine that can compute all computable functions and construct a replica of itself in any accessible and sufficiently large region of t

  7. 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.

  8. 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...

  9. Nuclear imprisonment: viral strategies to arrest host mRNA nuclear export.

    Science.gov (United States)

    Kuss, Sharon K; Mata, Miguel A; Zhang, Liang; Fontoura, Beatriz M A

    2013-07-01

    Viruses possess many strategies to impair host cellular responses to infection. Nuclear export of host messenger RNAs (mRNA) that encode antiviral factors is critical for antiviral protein production and control of viral infections. Several viruses have evolved sophisticated strategies to inhibit nuclear export of host mRNAs, including targeting mRNA export factors and nucleoporins to compromise their roles in nucleo-cytoplasmic trafficking of cellular mRNA. Here, we present a review of research focused on suppression of host mRNA nuclear export by viruses, including influenza A virus and vesicular stomatitis virus, and the impact of this viral suppression on host antiviral responses.

  10. Clinically used selective estrogen receptor modulators affect different steps of macrophage-specific reverse cholesterol transport.

    Science.gov (United States)

    Fernández-Suárez, María E; Escolà-Gil, Joan C; Pastor, Oscar; Dávalos, Alberto; Blanco-Vaca, Francisco; Lasunción, Miguel A; Martínez-Botas, Javier; Gómez-Coronado, Diego

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are widely prescribed drugs that alter cellular and whole-body cholesterol homeostasis. Here we evaluate the effect of SERMs on the macrophage-specific reverse cholesterol transport (M-RCT) pathway, which is mediated by HDL. Treatment of human and mouse macrophages with tamoxifen, raloxifene or toremifene induced the accumulation of cytoplasmic vesicles of acetyl-LDL-derived free cholesterol. The SERMs impaired cholesterol efflux to apolipoprotein A-I and HDL, and lowered ABCA1 and ABCG1 expression. These effects were not altered by the antiestrogen ICI 182,780 nor were they reproduced by 17β-estradiol. The treatment of mice with tamoxifen or raloxifene accelerated HDL-cholesteryl ester catabolism, thereby reducing HDL-cholesterol concentrations in serum. When [(3)H]cholesterol-loaded macrophages were injected into mice intraperitoneally, tamoxifen, but not raloxifene, decreased the [(3)H]cholesterol levels in serum, liver and feces. Both SERMs downregulated liver ABCG5 and ABCG8 protein expression, but tamoxifen reduced the capacity of HDL and plasma to promote macrophage cholesterol efflux to a greater extent than raloxifene. We conclude that SERMs interfere with intracellular cholesterol trafficking and efflux from macrophages. Tamoxifen, but not raloxifene, impair M-RCT in vivo. This effect is primarily attributable to the tamoxifen-mediated reduction of the capacity of HDL to promote cholesterol mobilization from macrophages. PMID:27601313

  11. 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 – ...

  12. 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 ...

  13. 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 ...

  14. Iran, a gas exporter?

    International Nuclear Information System (INIS)

    The development of the gas sector has not allowed, up to now, Iran to become one of the main gas actors, whether it is on the regional or international market. This under-development of the gas sector finds expression, each winter, through the Iranian incapability to satisfy its domestic demand as well as its exportation commitments to Turkey or Armenia. In this study, the author tries to examine the origins of Iranian difficulties to increase its gas production and to abide by its commitments to export gas to other countries. The possibility of gas exportation from Iran to the European Union is also discussed

  15. Guide to software export

    CERN Document Server

    Philips, Roger A

    2014-01-01

    An ideal reference source for CEOs, marketing and sales managers, sales consultants, and students of international marketing, Guide to Software Export provides a step-by-step approach to initiating or expanding international software sales. It teaches you how to examine critically your candidate product for exportability; how to find distributors, agents, and resellers abroad; how to identify the best distribution structure for export; and much, much more!Not content with providing just the guidelines for setting up, expanding, and managing your international sales channels, Guide to Software

  16. The Observation of Highly Ordered Domains in Membranes with Cholesterol

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Clare L [McMaster University; Marquardt, Drew [Brock University, St. Catharines, ON, Canada; Dies, Hannah [McMaster University; Kucerka, Norbert [Canadian Neutron Beam Centre and Comelius University (Slovakia); Yamani, Zahra [Canadian Neutron Beam Centre, National Research Council, Chalk River Laboratorie; Harroun, Thad [Brock University, St. Catharines, ON, Canada; Katsaras, John [ORNL; Shi, A-C [McMaster University; Rheinstadter, Maikel C [McMaster University

    2013-01-01

    Rafts, or functional domains, are transient nano- or mesoscopic structures in the exoplasmic leaflet of the plasma membrane, and are thought to be essential for many cellular processes. Using neutron diffraction and computer modelling, we present evidence for the existence of highly ordered lipid domains in the cholesterol-rich (32.5 mol%) liquid-ordered (lo) phase of dipalmitoylphosphatidylcholine membranes. The liquid ordered phase in one-component lipid membranes has previously been thought to be a homogeneous phase. The presence of highly ordered lipid domains embedded in a disordered lipid matrix implies non-uniform distribution of cholesterol between the two phases. The experimental results are in excellent agreement with recent computer simulations of DPPC/cholesterol complexes [Meinhardt, Vink and Schmid (2013). Proc Natl Acad Sci USA 110(12): 4476 4481], which reported the existence of nanometer size lo domains in a liquid disordered lipid environment.

  17. Restoring Mitochondrial Function: A Small Molecule-mediated Approach to Enhance Glucose Stimulated Insulin Secretion in Cholesterol Accumulated Pancreatic beta cells.

    Science.gov (United States)

    Asalla, Suman; Girada, Shravan Babu; Kuna, Ramya S; Chowdhury, Debabrata; Kandagatla, Bhaskar; Oruganti, Srinivas; Bhadra, Utpal; Bhadra, Manika Pal; Kalivendi, Shasi Vardhan; Rao, Swetha Pavani; Row, Anupama; Ibrahim, A; Ghosh, Partha Pratim; Mitra, Prasenjit

    2016-01-01

    Dyslipidemia, particularly the elevated serum cholesterol levels, aggravate the pathophysiology of type 2 diabetes. In the present study we explored the relationship between fasting blood sugar and serum lipid parameters in human volunteers which revealed a significant linear effect of serum cholesterol on fasting blood glucose. Short term feeding of cholesterol enriched diet to rodent model resulted in elevated serum cholesterol levels, cholesterol accumulation in pancreatic islets and hyperinsulinemia with modest increase in plasma glucose level. To explore the mechanism, we treated cultured BRIN-BD11 pancreatic beta cells with soluble cholesterol. Our data shows that cholesterol treatment of cultured pancreatic beta cells enhances total cellular cholesterol. While one hour cholesterol exposure enhances insulin exocytosis, overnight cholesterol accumulation in cultured pancreatic beta cells affects cellular respiration, and inhibits Glucose stimulated insulin secretion. We further report that (E)-4-Chloro-2-(1-(2-(2,4,6-trichlorophenyl) hydrazono) ethyl) phenol (small molecule M1) prevents the cholesterol mediated blunting of cellular respiration and potentiates Glucose stimulated insulin secretion which was abolished in pancreatic beta cells on cholesterol accumulation. PMID:27282931

  18. 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...

  19. Exploitative Learning by Exporting

    DEFF Research Database (Denmark)

    Golovko, Elena; Lopes Bento, Cindy; Sofka, Wolfgang

    Decisions on entering foreign markets are among the most challenging but also potentially rewarding strategy choices managers can make. In this study, we examine the effect of export entry on the firm investment decisions in two activities associated with learning about new technologies...... and learning about new markets ? R&D investments and marketing investments, in search of novel insights into the content and process underlying learning by exporting. We draw from organizational learning theory for predicting changes in both R&D and marketing investment patterns that accompany firm entry......, it is predominantly the marketing-related investment decisions associated with starting to export that lead to increases in firm productivity. We conclude that learning-by-exporting might be more properly characterized as ?learning about and exploiting new markets? rather than ?learning about new technologies...

  20. Valie EXPORT Society Rooseumis

    Index Scriptorium Estoniae

    2002-01-01

    Malmös Rooseumi Kaasaegse Kunsti Keskuses näitus "Baltic Babel". Projekt koosneb Läänemeremaade linnades tegutsevate innovatiivsete gruppide aktsioonidest. Kuraator Charles Esche. Esinejatest (Eestist Valie Export Society: Kadi Estland, Killu Sukmit)

  1. Slowed Exports Growth

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Ⅲ. Slowed export recovery in the second half Since the beginning of this year, global trade has maintained a recovery growth thanks to the worldwide economic rally.From January to April, the imports of three major Economics--the United States, the euro zone and Japan--rose 17.5 percent on average from a year ago. Import growths for the United States, the euro zone and Japan were 20.9 percent, 4.8 percent and 29 percent, respectively, which spurred China's exports to those regions. From January to June this year, China's exports totaled $705.09 billion, up 35.2 percent from the same period in 2009 and were 5.8 percent higher than the first half of 2008 when the crisis had yet to begin. Those figures indicated China's exports had rebounded to precrisis levels.

  2. Valie EXPORT Society. Overlok

    Index Scriptorium Estoniae

    2001-01-01

    Valie EXPORT Society asutasid 23. okt. 1999. a. Frankfurdis Kadi Estland, Killu Sukmit ja Mari Laanemets, kui olid külastanud austria naiskunstniku Valie Exporti näitust. Rühmituse aktsioonide kirjeldus

  3. Illegal Weapons Exports?

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Amnesty International, a human rights organization, released a report on June 11 accusing China of facilitating regional conflicts and human rights violations by exporting a large quantity of weapons to Sudan, Nepal, Myanmar and the Great Lakes countries of Africa. Responding to such charges, Teng Jianqun, a researcher with the China Arms Control and Disarmament Association, told the official Xinhua News Agency that China has always put its limited arms exports under strict control and surveillance, deno...

  4. Endosomal cholesterol trafficking: protein factors at a glance

    Institute of Scientific and Technical Information of China (English)

    Ximing Du; Hongyuan Yang

    2013-01-01

    The delivery of low-density lipoprotein-derived cholesterol (LDL-C) from endosomal compartments to the plasma membrane and the endoplasmic reticulum (ER) is an important yet poorly understood cellular process.NiemannPick C1 (NPC1),a multi-pass integral membrane protein on the limiting membranes of late endosomes (LE)/lysosomes (Ly),is known to insert lumenal LDL-C to the limiting membrane of LE/Ly.Recent progress has identified novel cytoplasmic proteins that regulate the exit of LDL-C from LE/Ly,such as ORP5,a member of the oxysterolbinding protein-related protein (ORPs) family,and Hrs/VPS27,a well-established regulator of the endosomal sorting complex required for transport pathway.Whereas ORP5/ORPs may serve as cytosolic cholesterol carriers and deliver cholesterol in a non-vesicular manner,how Hrs/VPS27 regulate endosomal cholesterol sorting remains enigmatic.We discuss the functional relationship between NPC1,Hrs,and ORP5,and formulate possible schemes on how LDL-C may be moved from endosomal compartments to other cellular organelles.

  5. 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)

  6. 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.

  7. 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

  8. 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.

  9. Intracellular cholesterol transport proteins: roles in health and disease.

    Science.gov (United States)

    Soffientini, Ugo; Graham, Annette

    2016-11-01

    Effective cholesterol homoeostasis is essential in maintaining cellular function, and this is achieved by a network of lipid-responsive nuclear transcription factors, and enzymes, receptors and transporters subject to post-transcriptional and post-translational regulation, whereas loss of these elegant, tightly regulated homoeostatic responses is integral to disease pathologies. Recent data suggest that sterol-binding sensors, exchangers and transporters contribute to regulation of cellular cholesterol homoeostasis and that genetic overexpression or deletion, or mutations, in a number of these proteins are linked with diseases, including atherosclerosis, dyslipidaemia, diabetes, congenital lipoid adrenal hyperplasia, cancer, autosomal dominant hearing loss and male infertility. This review focuses on current evidence exploring the function of members of the 'START' (steroidogenic acute regulatory protein-related lipid transfer) and 'ORP' (oxysterol-binding protein-related proteins) families of sterol-binding proteins in sterol homoeostasis in eukaryotic cells, and the evidence that they represent valid therapeutic targets to alleviate human disease. PMID:27660308

  10. Constitutive hippocampal cholesterol loss underlies poor cognition in old rodents.

    Science.gov (United States)

    Martin, Mauricio G; Ahmed, Tariq; Korovaichuk, Alejandra; Venero, Cesar; Menchón, Silvia A; Salas, Isabel; Munck, Sebastian; Herreras, Oscar; Balschun, Detlef; Dotti, Carlos G

    2014-05-30

    Cognitive decline is one of the many characteristics of aging. Reduced long-term potentiation (LTP) and long-term depression (LTD) are thought to be responsible for this decline, although the precise mechanisms underlying LTP and LTD dampening in the old remain unclear. We previously showed that aging is accompanied by the loss of cholesterol from the hippocampus, which leads to PI3K/Akt phosphorylation. Given that Akt de-phosphorylation is required for glutamate receptor internalization and LTD, we hypothesized that the decrease in cholesterol in neuronal membranes may contribute to the deficits in LTD typical of aging. Here, we show that cholesterol loss triggers p-Akt accumulation, which in turn perturbs the normal cellular and molecular responses induced by LTD, such as impaired AMPA receptor internalization and its reduced lateral diffusion. Electrophysiology recordings in brain slices of old mice and in anesthetized elderly rats demonstrate that the reduced hippocampal LTD associated with age can be rescued by cholesterol perfusion. Accordingly, cholesterol replenishment in aging animals improves hippocampal-dependent learning and memory in the water maze test.

  11. 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.

  12. 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 ...

  13. Rethinking the National Export Initiative

    OpenAIRE

    Caroline Freund

    2014-01-01

    Four years ago, President Barack Obama set the goal of doubling exports within five years and creating 2 million new export-related jobs. The strategy put in place, however, has failed to achieve superior growth. Freund argues that the emphasis on small and medium enterprises in the National Export Initiative, while attractive, was misguided and recommends a specific set of policies that the administration should concentrate on to boost exports. An export boom requires a system that encourage...

  14. FLIM studies of 22- and 25-NBD-cholesterol in living HEK293 cells: plasma membrane change induced by cholesterol depletion.

    Science.gov (United States)

    Ostašov, Pavel; Sýkora, Jan; Brejchová, Jana; Olżyńska, Agnieszka; Hof, Martin; Svoboda, Petr

    2013-01-01

    HEK293 cells stably expressing δ-opioid receptor were labeled first with fluorescent analog of cholesterol, 22-NBD-cholesterol, exposed to cholesterol-depleting agent β-cyclodextrin (β-CDX) and analyzed by fluorescence lifetime imaging microscopy (FLIM). In accordance with chemical analysis of cholesterol level, the total cellular signal of this probe was decreased to half. Distribution of lifetime (τtot) values of 22-NBD-cholesterol, however, when screened over the whole cell area indicated no significant difference between control (τtot=4.9±0.1 ns) and β-CDX-treated (τtot=4.8±0.1 ns) cells. On the contrary, comparison of control (τtot=5.1±0.1 ns) and β-CDX-treated (τtot=4.4±0.1 ns) cells by analysis of 25-NBD-cholesterol fluorescence implied highly significant decrease of lifetime values of this probe. The observation that 22-NBD-cholesterol appears to be indifferent to the changes in the membrane packing in living cells is in agreement with previous studies in model membranes. However, our data indicate that the alternation of plasma membrane structure induced by decrease of cholesterol level by β-CDX makes the membrane environment of NBD moiety of 25-NBD-cholesterol probe a significantly more hydrated. This finding not only encourages using 25-NBD-cholesterol in living cells, but also demonstrates that previously drawn discouraging conclusions on the use of 25-NBD-cholesterol in model membranes are not valid for living cells. PMID:23466534

  15. Molecular mechanisms underlying the cholesterol-lowering effect of Ginkgo biloba extract in hepatocytes: a comparative study with Iovastatin

    Institute of Scientific and Technical Information of China (English)

    Zuo-quan XIE; Gai LIANG; Lu ZHANG; Qi WANG; Yi QU; Yang GAO; Li-bo LIN; Sai YE; Ji ZHANG; Hui WANG; Guo-ping ZHAO; Qing-hua ZHANG

    2009-01-01

    Aim: To explore the molecular mechanisms underlying the cholesterol-lowering effect of a Ginkgo biloba extract (GBE). Methods: Enzyme activity, cholesterol flux and changes in gene expression levels were assessed in cultured hepatocytes treated with GBE or Iovastatin. Results: GBE decreased the total cholesterol content in cultured hepatocytes and inhibited the activity of HMG-CoA reductase, as determined by an in vitro enzyme activity assay. In addition, GBE decreased cholesterol influx, whereas Iovastatin increased choles-terol influx. GBE treatment induced significant increases in the expression of cholesterogenic genes and genes involved in cholesterol metabolism, such as SREBF2, as determined by cDNA microarray and real-time RT-PCR. Furthermore, INSIG2, LDLR, LRP1, and LRP10 were differentially regulated by GBE and Iovastatin. The data imply that the two compounds modulate cholesterol metabolism through distinct mechanisms. Conclusion: By using a gene expression profiling approach, we were able to broaden the understanding of the molecular mechanisms by which GBE lowers cellular cholesterol levels. Specifically, we demonstrated that GBE exhibited dual effects on the cellular choles-terol pool by modulating both HMG-CoA reductase activity and inhibiting cholesterol influx.

  16. 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...

  17. Luminol electrochemiluminescence for the analysis of active cholesterol at the plasma membrane in single mammalian cells.

    Science.gov (United States)

    Ma, Guangzhong; Zhou, Junyu; Tian, Chunxiu; Jiang, Dechen; Fang, Danjun; Chen, Hongyuan

    2013-04-16

    A luminol electrochemiluminescence assay was reported to analyze active cholesterol at the plasma membrane in single mammalian cells. The cellular membrane cholesterol was activated by the exposure of the cells to low ionic strength buffer or the inhibition of intracellular acyl-coA/cholesterol acyltransferase (ACAT). The active membrane cholesterol was reacted with cholesterol oxidase in the solution to generate a peak concentration of hydrogen peroxide on the electrode surface, which induced a measurable luminol electrochemiluminescence. Further treatment of the active cells with mevastatin decreased the active membrane cholesterol resulting in a drop in luminance. No change in the intracellular calcium was observed in the presence of luminol and voltage, which indicated that our analysis process might not interrupt the intracellular cholesterol trafficking. Single cell analysis was performed by placing a pinhole below the electrode so that only one cell was exposed to the photomultiplier tube (PMT). Twelve single cells were analyzed individually, and a large deviation on luminance ratio observed exhibited the cell heterogeneity on the active membrane cholesterol. The smaller deviation on ACAT/HMGCoA inhibited cells than ACAT inhibited cells suggested different inhibition efficiency for sandoz 58035 and mevastatin. The new information obtained from single cell analysis might provide a new insight on the study of intracellular cholesterol trafficking. PMID:23527944

  18. 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…

  19. Liver X Receptor β and Peroxisome Proliferator-Activated Receptor δ regulate cholesterol transport in cholangiocytes

    Science.gov (United States)

    Xia, Xuefeng; Jung, Dongju; Webb, Paul; Zhang, Aijun; Zhang, Bin; Li, Lifei; Ayers, Stephen D.; Gabbi, Chiara; Ueno, Yoshiyuki; Gustafsson, Jan-Åke; Alpini, Gianfranco; Moore, David D.; LeSage, Gene D.

    2012-01-01

    Nuclear receptors (NRs) play crucial roles in regulation of hepatic cholesterol synthesis, metabolism and conversion to bile acids, but their actions in cholangiocytes have not been examined. In this study, we investigated the roles of NRs in cholangiocyte physiology and cholesterol metabolism and flux. We examined the expression of NRs and other genes involved in cholesterol homeostasis in freshly isolated and cultured rodent cholangiocytes and found that these cells express a specific subset of NRs which includes Liver X Receptor β (LXRβ) and Peroxisome Proliferator-Activated Receptor δ (PPARδ). Activation of LXRβ and/or PPARδ in cholangiocytes induces ATP-binding cassette cholesterol transporter A1 (ABCA1) and increases cholesterol export at the basolateral compartment in polarized cultured cholangiocytes. In addition, PPARδ induces Niemann Pick C1 Like L1 (NPC1L1), which imports cholesterol into cholangiocytes and is expressed on the apical cholangiocyte membrane, via specific interaction with a PPRE within the NPC1L1 promoter. Based on these studies, we propose that (i) LXRβ and PPARδ coordinate NPC1L1/ABCA1 dependent vectorial cholesterol flux from bile through cholangiocytes and (ii) manipulation of these processes may influence bile composition with important applications in cholestatic liver disease and gallstone disease, serious health concerns for humans. PMID:22729460

  20. 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

  1. Cholesterol Depletion Reduces the Internalization of β-Amyloid Peptide in SH-SY5Y Cells

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qinghua; HE Li; SUI Senfang

    2006-01-01

    Deposition of amyloid in the brain is a critical step in the pathogenesis of Alzheimer's disease. The endocytosis of β-amyloid peptide (Aβ) is an important factor among the many factors that contribute to the genesis of amyloid deposits. Since cholesterol participates in many important physiological processes, the present work investigated the relationship between the cellular cholesterol content and the endocytosis of the exogenic Aβ, and found that reduction of the cholesterol content by methyl-β-cyclodextrin could reduce the endocytosis of Aβ. The study indicates that the endocytosis of Aβ is partly mediated by cholesterol.

  2. Mathematical Modeling of Cellular Metabolism.

    Science.gov (United States)

    Berndt, Nikolaus; Holzhütter, Hermann-Georg

    2016-01-01

    Cellular metabolism basically consists of the conversion of chemical compounds taken up from the extracellular environment into energy (conserved in energy-rich bonds of organic phosphates) and a wide array of organic molecules serving as catalysts (enzymes), information carriers (nucleic acids), and building blocks for cellular structures such as membranes or ribosomes. Metabolic modeling aims at the construction of mathematical representations of the cellular metabolism that can be used to calculate the concentration of cellular molecules and the rates of their mutual chemical interconversion in response to varying external conditions as, for example, hormonal stimuli or supply of essential nutrients. Based on such calculations, it is possible to quantify complex cellular functions as cellular growth, detoxification of drugs and xenobiotic compounds or synthesis of exported molecules. Depending on the specific questions to metabolism addressed, the methodological expertise of the researcher, and available experimental information, different conceptual frameworks have been established, allowing the usage of computational methods to condense experimental information from various layers of organization into (self-) consistent models. Here, we briefly outline the main conceptual frameworks that are currently exploited in metabolism research.

  3. Cellular Telephone

    Institute of Scientific and Technical Information of China (English)

    杨周

    1996-01-01

    Cellular phones, used in automobiles, airliners, and passenger trains, are basically low-power radiotelephones. Calls go through radio transmitters that are located within small geographical units called cells. Because each cell’s signals are too weak to interfere with those of other cells operating on the same fre-

  4. Human immunodeficiency virus impairs reverse cholesterol transport from macrophages.

    Directory of Open Access Journals (Sweden)

    Zahedi Mujawar

    2006-10-01

    Full Text Available 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 cholesterol efflux from human macrophages, a condition previously shown to be highly atherogenic. In HIV-1-infected cells, this effect was mediated by Nef. Transfection of murine macrophages with Nef impaired cholesterol efflux from these cells. At least two mechanisms were found to be responsible for this phenomenon: first, HIV infection and transfection with Nef induced post-transcriptional down-regulation of ABCA1; and second, Nef caused redistribution of ABCA1 to the plasma membrane and inhibited internalization of apolipoprotein A-I. Binding of Nef to ABCA1 was required for down-regulation and redistribution of ABCA1. HIV-infected and Nef-transfected macrophages accumulated substantial amounts of lipids, thus resembling foam cells. The contribution of HIV-infected macrophages to the pathogenesis of atherosclerosis was supported by the presence of HIV-positive foam cells in atherosclerotic plaques of HIV-infected patients. Stimulation of cholesterol efflux from macrophages significantly reduced infectivity of the virions produced by these cells, and this effect correlated with a decreased amount of virion-associated cholesterol, suggesting that impairment of cholesterol efflux is essential to ensure proper cholesterol content in nascent HIV particles. These results reveal a previously unrecognized dysregulation of intracellular lipid metabolism in HIV-infected macrophages and identify Nef and ABCA1 as the key players responsible for this effect. Our findings

  5. Cholesterol transport via ABCA1: new insights from solid-phase binding assay.

    Science.gov (United States)

    Reboul, Emmanuelle; Dyka, Frank M; Quazi, Faraz; Molday, Robert S

    2013-04-01

    It is now well established that the ATP-binding cassette transporter A1 (ABCA1) plays a pivotal role in HDL metabolism, reverse cholesterol transport and net efflux of cellular cholesterol and phospholipids. We aimed to resolve some uncertainties related to the putative function of ABCA1 as a mediator of lipid transport by using a methodology developed in the laboratory to isolate a protein and study its interactions with other compounds. ABCA1 was tagged with the 1D4 peptide at the C terminus and expressed in human HEK 293 cells. Preliminary experiments showed that the tag modified neither the protein expression/localization within the cells nor the ability of ABCA1 to promote cholesterol cellular efflux to apolipoprotein A-I. ABCA1-1D4 was then purified and reconstituted in liposomes. ABCA1 displayed an ATPase activity in phospholipid liposomes that was significantly decreased by cholesterol. Finally, interactions with either cholesterol or apolipoprotein A-I were assessed by binding experiments with protein immobilized on an immunoaffinity matrix. Solid-phase binding assays showed no direct binding of cholesterol or apolipoprotein A-I to ABCA1. Overall, our data support the hypothesis that ABCA1 is able to mediate the transport of cholesterol from cells without direct interaction and that apo A-I primarily binds to membrane surface or accessory protein(s). PMID:23201557

  6. Mechanism of the hepatic lipase induced accumulation of high-density lipoprotein cholesterol by cells in culture

    International Nuclear Information System (INIS)

    Hepatic lipase can enhance the delivery of high-density lipoprotein (HDL) cholesterol to cells by a process which does not involve apoprotein catabolism. The incorporation of HDL-free (unesterified) cholesterol, phospholipid, and cholesteryl ester by cells has been compared to establish the mechanism of this delivery process. Human HDL was reconstituted with 3H-free cholesterol and [14C]sphingomyelin, treated with hepatic lipase in the presence of albumin to remove the products of lipolysis, reisolated, and then incubated with cultured rat hepatoma cells. Relative to control HDL, modification of HDL with hepatic lipase stimulated both the amount of HDL-free cholesterol taken up by the cell and the esterification of HDL-free cholesterol but did not affect the delivery of sphingomyelin. Experiments utilizing HDL reconstituted with 14C-free cholesterol and [3H]cholesteryl oleoyl ether suggest that hepatic lipase enhances the incorporation of HDL-esterified cholesterol. However, the amount of free cholesterol delivered as a result of treatment with hepatic lipase was 4-fold that of esterified cholesterol. On the basis of HDL composition, the cellular incorporation of free cholesterol was about 10 times that which would occur by the uptake and degradation of intact particles. The preferential incorporation of HDL-free cholesterol did not require the presence of lysophosphatidylcholine. To correlate the events observed at the cellular level with alterations in lipoprotein structure, high-resolution, proton-decoupled 13C nuclear magnetic resonance spectroscopy (90.55 MHz) was performed on HDL3 in which the cholesterol molecules were replaced with [4-13C]cholesterol by particle reconstitution

  7. 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.

  8. Urotensin II promotes atherosclerosis in cholesterol-fed rabbits.

    Directory of Open Access Journals (Sweden)

    Yafeng Li

    Full Text Available Urotensin II (UII is a vasoactive peptide composed of 11 amino acids that has been implicated to contribute to the development of cardiovascular disease. The purpose of this study was to investigate whether UII affects the development of atherosclerosis in cholesterol-fed rabbits. UII was infused for 16 weeks through an osmotic mini-pump into male Japanese White rabbits fed on a high-cholesterol diet. Plasma lipids and body weight were measured every 4 weeks. Aortic atherosclerotic lesions along with cellular components, collagen fibers, matrix metalloproteinase-1 and -9 were examined. Moreover, vulnerability index of atherosclerotic plaques was evaluated. UII infusion significantly increased atherosclerotic lesions within the entire aorta by 21% over the control (P = 0.013. Atherosclerotic lesions were increased by 24% in the aortic arch (P = 0.005, 11% in the thoracic aorta (P = 0.054 and 18% in the abdominal aorta (P = 0.035. These increases occurred without changes in plasma levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides or body weight. Immunohistochemical staining revealed that macrophages and matrix metalloproteinase-9 were significantly enhanced by 2.2-fold and 1.6-fold in UII group. In vitro studies demonstrated that UII up-regulated the expression of vascular cell adhesion protein-1 and intercellular adhesion molecule-1 in human umbilical vein endothelial cells, which was inhibited by the UII receptor antagonist urantide. In conclusion, our results showed that UII promotes the development of atherosclerotic lesions and destabilizes atherosclerotic plaques in cholesterol-fed rabbits.

  9. 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.

  10. 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

  11. Export of textile machinery products

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In 2007, the export of textile machinery products continued to keep a rapidly increasing trend. In accordance with the statistics from the custom, as of December this year, the value of exported textile machinery products was USD1.528 billion, increased by 23.54% over the previous year. Except that the export of nonwoven cloth machinery products reduced to a certain degree compared with that in 2006, the export of other varieties of products increased greatly. The export of textile machinery products had been remaining relatively rapid growth since 2000. During this period, the structure of exported products has changed continuously, so do export enterprises. There are still many problems in export of textile machinery products, and manufacturers of textile machinery products should improve and advance continuously. However, on the whole, the integrated and international competitiveness of textile machinery products is enhanced, so is the internationalization level of manufacturers of textile machinery products.

  12. Improved Coarse-Grained Modeling of Cholesterol-Containing Lipid Bilayers

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-24

    In mammalian cells cholesterol is essential for membrane function, but in excess can be cytototoxic. The cellular response to acute cholesterol loading involves biophysical-based mechanisms that regulate cholesterol levels, through modulation of the “activity” or accessibility of cholesterol to extra-membrane acceptors. Experiments and united atom (UA) simulations show that at high concentrations of cholesterol, lipid bilayers thin significantly and cholesterol availability to external acceptors increases substantially. Such cholesterol activation is critical to its trafficking within cells. Here we aim to reduce the computational cost to enable simulation of large and complex systems involved in cholesterol regulation, such as those including oxysterols and cholesterol-sensing proteins. To accomplish this, we have modified the published MARTINI coarse-grained force field to improve its predictions of cholesterol-induced changes in both macroscopic and microscopic properties of membranes. Most notably, MARTINI fails to capture both the (macroscopic) area condensation and membrane thickening seen at less than 30% cholesterol and the thinning seen above 40% cholesterol. The thinning at high concentration is critical to cholesterol activation. Microscopic properties of interest include cholesterol-cholesterol radial distribution functions (RDFs), tilt angle, and accessible surface area. First, we develop an “angle-corrected” model wherein we modify the coarse-grained bond angle potentials based on atomistic simulations. This modification significantly improves prediction of macroscopic properties, most notably the thickening/thinning behavior, and also slightly improves microscopic property prediction relative to MARTINI. Second, we add to the angle correction a “volume correction” by also adjusting phospholipid bond lengths to achieve a more accurate volume per molecule. The angle + volume correction substantially further improves the quantitative

  13. Exporting to Russia?

    DEFF Research Database (Denmark)

    Thomsen, Lotte

    2016-01-01

    This article draws on extensive fieldwork conducted in Central Asia to explore food exports to Russia. It takes its theoretical starting point in global value chain theory and pinpoints chain entry barriers relating to financing, transportation and standards. The article also proposes rethinking...

  14. Export oriented industrialization strategies

    OpenAIRE

    Karunaratne, Neil Dias

    1980-01-01

    Disappointment about the results of import substituting industrialization strategies as well as the spectacular performance of a few newly industrialised countries have led many developing countries to switch in the 1970s to export oriented industrialization. This analysis cautions against any misplaced euphoria with regard to this strategy in a neo-mercantilistic and hegemonic world.

  15. China Reshuffles Export Incentives

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    What it means for China's economy... Last month, the Chinese Government made sweeping changes to the export tax breaks that domestic companies receive. Here's what happened: On September 14, the Ministry of Finance, the General Administration of Customs, the National Development and Reform Commission, the Ministry of

  16. Benchmarking Nordic Music Export Operations

    OpenAIRE

    Koponen, Arto

    2016-01-01

    Increasing export is necessary for companies and organizations in order to make profit in more globalized business environment. The field of exporting is also ever changing, especially regarding music exporting. The aim of this research project was to explore and improve the joint music export operations in the Nordics. It was assigned by Music Finland which administrates the umbrella organization for a Nordic co-operation called NOMEX. Thus, the author set to discover favorable practices...

  17. Export Restructuring on Rebates Change

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Again, the Chinese governmenthas recently adjusted the export tax rebates upon 2831 categories of goods, accounting for 37% of the nation's total export products. Export rebates on most products have decreased by 2% to 4%, and some have had an even steeper reduction. For instance,the export tax rebate has plummeted from 11% or 13% to zero on cement and chemical products, which are called "high-energy-consumption.

  18. The membrane as the gatekeeper of infection: Cholesterol in host-pathogen interaction.

    Science.gov (United States)

    Kumar, G Aditya; Jafurulla, Md; Chattopadhyay, Amitabha

    2016-09-01

    The cellular plasma membrane serves as a portal for the entry of intracellular pathogens. An essential step for an intracellular pathogen to gain entry into a host cell therefore is to be able to cross the cell membrane. In this review, we highlight the role of host membrane cholesterol in regulating the entry of intracellular pathogens using insights obtained from work on the interaction of Leishmania and Mycobacterium with host cells. The entry of these pathogens is known to be dependent on host membrane cholesterol. Importantly, pathogen entry is inhibited either upon depletion (or complexation), or enrichment of membrane cholesterol. In other words, an optimum level of host membrane cholesterol is necessary for efficient infection by pathogens. In this overall context, we propose a general mechanism, based on cholesterol-induced conformational changes, involving cholesterol binding sites in host cell surface receptors that are implicated in this process. A therapeutic strategy targeting modulation of membrane cholesterol would have the advantage of avoiding the commonly encountered problem of drug resistance in tackling infection by intracellular pathogens. Insights into the role of host membrane cholesterol in pathogen entry would be instrumental in the development of novel therapeutic strategies to effectively tackle intracellular pathogenesis. PMID:26902688

  19. The cholesterol-dependent cytolysin family of gram-positive bacterial toxins.

    Science.gov (United States)

    Heuck, Alejandro P; Moe, Paul C; Johnson, Benjamin B

    2010-01-01

    The cholesterol-dependent cytolysins (CDCs) are a family of beta-barrel pore-forming toxins secreted by Gram-positive bacteria. These toxins are produced as water-soluble monomeric proteins that after binding to the target cell oligomerize on the membrane surface forming a ring-like pre-pore complex, and finally insert a large beta-barrel into the membrane (about 250 A in diameter). Formation of such a large transmembrane structure requires multiple and coordinated conformational changes. The presence of cholesterol in the target membrane is absolutely required for pore-formation, and therefore it was long thought that cholesterol was the cellular receptor for these toxins. However, not all the CDCs require cholesterol for binding. Intermedilysin, secreted by Streptoccocus intermedius only binds to membranes containing a protein receptor, but forms pores only if the membrane contains sufficient cholesterol. In contrast, perfringolysin O, secreted by Clostridium perfringens, only binds to membranes containing substantial amounts of cholesterol. The mechanisms by which cholesterol regulates the cytolytic activity of the CDCs are not understood at the molecular level. The C-terminus of perfringolysin O is involved in cholesterol recognition, and changes in the conformation of the loops located at the distal tip of this domain affect the toxin-membrane interactions. At the same time, the distribution of cholesterol in the membrane can modulate toxin binding. Recent studies support the concept that there is a dynamic interplay between the cholesterol-binding domain of the CDCs and the excess of cholesterol molecules in the target membrane. PMID:20213558

  20. Competitive and Cooperative Interactions Mediate RNA Transfer from Herpesvirus Saimiri ORF57 to the Mammalian Export Adaptor ALYREF

    OpenAIRE

    Tunnicliffe, Richard B.; Hautbergue, Guillaume M.; Wilson, Stuart A.; Priti Kalra; Golovanov, Alexander P.

    2014-01-01

    The essential herpesvirus adaptor protein HVS ORF57, which has homologs in all other herpesviruses, promotes viral mRNA export by utilizing the cellular mRNA export machinery. ORF57 protein specifically recognizes viral mRNA transcripts, and binds to proteins of the cellular transcription-export (TREX) complex, in particular ALYREF. This interaction introduces viral mRNA to the NXF1 pathway, subsequently directing it to the nuclear pore for export to the cytoplasm. Here we have used a range o...

  1. Cytomegalovirus Restructures Lipid Rafts via a US28/CDC42-Mediated Pathway, Enhancing Cholesterol Efflux from Host Cells.

    Science.gov (United States)

    Low, Hann; Mukhamedova, Nigora; Cui, Huanhuan L; McSharry, Brian P; Avdic, Selmir; Hoang, Anh; Ditiatkovski, Michael; Liu, Yingying; Fu, Ying; Meikle, Peter J; Blomberg, Martin; Polyzos, Konstantinos A; Miller, William E; Religa, Piotr; Bukrinsky, Michael; Soderberg-Naucler, Cecilia; Slobedman, Barry; Sviridov, Dmitri

    2016-06-28

    Cytomegalovirus (HCMV) contains cholesterol, but how HCMV interacts with host cholesterol metabolism is unknown. We found that, in human fibroblasts, HCMV infection increased the efflux of cellular cholesterol, despite reducing the abundance of ABCA1. Mechanistically, viral protein US28 was acting through CDC42, rearranging actin microfilaments, causing association of actin with lipid rafts, and leading to a dramatic change in the abundance and/or structure of lipid rafts. These changes displaced ABCA1 from the cell surface but created new binding sites for apolipoprotein A-I, resulting in enhanced cholesterol efflux. The changes also reduced the inflammatory response in macrophages. HCMV infection modified the host lipidome profile and expression of several genes and microRNAs involved in cholesterol metabolism. In mice, murine CMV infection elevated plasma triglycerides but did not affect the level and functionality of high-density lipoprotein. Thus, HCMV, through its protein US28, reorganizes lipid rafts and disturbs cell cholesterol metabolism.

  2. 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

  3. Intracellular transport of low density lipoprotein-derived cholesterol is defective in Niemann-Pick type C fibroblasts

    International Nuclear Information System (INIS)

    Niemann-Pick disease type C (NPC) is characterized by substantial intracellular accumulation of unesterified cholesterol. The accumulation of unesterified cholesterol in NPC fibroblasts cultured with low density lipoprotein (LDL) appears to result from the inability of LDL to stimulate cholesterol esterification in addition to impaired LDL-mediated downregulation of LDL receptor activity and cellular cholesterol synthesis. Although a defect in cholesterol transport in NPC cells has been inferred from previous studies, no experiments have been reported that measure the intracellular movement of LDL-cholesterol specifically. We have used four approaches to assess intracellular cholesterol transport in normal and NPC cells and have determined the following: (a) mevinolin-inhibited NPC cells are defective in using LDL-cholesterol for growth. However, exogenously added mevalonate restores cell growth equally in normal and NPC cells; (b) the transport of LDL-derived [3H]cholesterol to the plasma membrane is slower in NPC cells, while the rate of appearance of [3H]acetate-derived, endogenously synthesized [3H]cholesterol at the plasma membrane is the same for normal and NPC cells; (c) in NPC cells, LDL-derived [3H]cholesterol accumulates in lysosomes to higher levels than normal, resulting in defective movement to other cell membranes; and (d) incubation of cells with LDL causes an increase in cholesterol content of NPC lysosomes that is threefold greater than that observed in normal lysosomes. Our results indicate that a cholesterol transport defect exists in NPC that is specific for LDL-derived cholesterol

  4. Intracellular transport of low density lipoprotein-derived cholesterol is defective in Niemann-Pick type C fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Liscum, L.; Ruggiero, R.M.; Faust, J.R.

    1989-05-01

    Niemann-Pick disease type C (NPC) is characterized by substantial intracellular accumulation of unesterified cholesterol. The accumulation of unesterified cholesterol in NPC fibroblasts cultured with low density lipoprotein (LDL) appears to result from the inability of LDL to stimulate cholesterol esterification in addition to impaired LDL-mediated downregulation of LDL receptor activity and cellular cholesterol synthesis. Although a defect in cholesterol transport in NPC cells has been inferred from previous studies, no experiments have been reported that measure the intracellular movement of LDL-cholesterol specifically. We have used four approaches to assess intracellular cholesterol transport in normal and NPC cells and have determined the following: (a) mevinolin-inhibited NPC cells are defective in using LDL-cholesterol for growth. However, exogenously added mevalonate restores cell growth equally in normal and NPC cells; (b) the transport of LDL-derived (3H)cholesterol to the plasma membrane is slower in NPC cells, while the rate of appearance of (3H)acetate-derived, endogenously synthesized (3H)cholesterol at the plasma membrane is the same for normal and NPC cells; (c) in NPC cells, LDL-derived (3H)cholesterol accumulates in lysosomes to higher levels than normal, resulting in defective movement to other cell membranes; and (d) incubation of cells with LDL causes an increase in cholesterol content of NPC lysosomes that is threefold greater than that observed in normal lysosomes. Our results indicate that a cholesterol transport defect exists in NPC that is specific for LDL-derived cholesterol.

  5. ABCG5/ABCG8-independent biliary cholesterol excretion in lactating rats

    OpenAIRE

    Coy, Donna J.; Wooton-Kee, Clavia R.; Yan, Baoxiang; Sabeva, Nadezhda; Su, Kai; Graf, Gregory; Vore, Mary

    2010-01-01

    Lactation is associated with increased expression of bile acid transporters and an increased size and hydrophobicity of the bile acid pool in rats. ATP-binding cassette (ABC) transporters multidrug resistance protein 2 (Mdr2), Abcb11 [bile salt export pump (Bsep)], and Abcg5/Abcg8 heterodimers are essential for the biliary secretion of phospholipids, bile acids, and cholesterol, respectively. We investigated the expression of these transporters and secretion of their substrates in female cont...

  6. Akt inhibition promotes ABCA1-mediated cholesterol efflux to ApoA-I through suppressing mTORC1.

    Directory of Open Access Journals (Sweden)

    Fumin Dong

    Full Text Available ATP-binding cassette transporter A1 (ABCA1 plays an essential role in mediating cholesterol efflux to apolipoprotein A-I (apoA-I, a major housekeeping mechanism for cellular cholesterol homeostasis. After initial engagement with ABCA1, apoA-I directly interacts with the plasma membrane to acquire cholesterol. This apoA-I lipidation process is also known to require cellular signaling processes, presumably to support cholesterol trafficking to the plasma membrane. We report here that one of major signaling pathways in mammalian cells, Akt, is also involved. In several cell models that express ABCA1 including macrophages, pancreatic beta cells and hepatocytes, inhibition of Akt increases cholesterol efflux to apoA-I. Importantly, Akt inhibition has little effect on cells expressing non-functional mutant of ABCA1, implicating a specific role of Akt in ABCA1 function. Furthermore, we provide evidence that mTORC1, a major downstream target of Akt, is also a negative regulator of cholesterol efflux. In cells where mTORC1 is constitutively activated due to tuberous sclerosis complex 2 deletion, cholesterol efflux to apoA-I is no longer sensitive to Akt activity. This suggests that Akt suppresses cholesterol efflux through mTORC1 activation. Indeed, inhibition of mTORC1 by rapamycin or Torin-1 promotes cholesterol efflux. On the other hand, autophagy, one of the major pathways of cholesterol trafficking, is increased upon Akt inhibition. Furthermore, Akt inhibition disrupts lipid rafts, which is known to promote cholesterol efflux to apoA-I. We therefore conclude that Akt, through its downstream targets, mTORC1 and hence autophagy, negatively regulates cholesterol efflux to apoA-I.

  7. 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 ...

  8. Exports of petroleum products, 1987

    International Nuclear Information System (INIS)

    A summary is presented of exports of motor gasoline, middle distillate, aviation turbine fuel, heavy fuel oil, and partially processed oil from Canada for the 1987 calendar year. A discussion of petroleum product imports is included in order to put exports in the context of the overall trade. Exports of the above petroleum products averaged 22,200 m3/d in 1987, up 15% from 1986 levels. Exports of middle distillates and aviation fuel had the largest gains in 1987. Export prices for light petroleum products stayed relatively close to USA spot prices. The heavy fuel oil price was below the New York spot price in the beginning of 1987 but remained close for the rest of the year. Canada's petroleum products exports were made to 5 countries while imports came from at least 13 countries. The USA remained Canada's largest trading partner in petroleum products. Exports to Japan and the Far East rose ca 60% over 1986. Product outturns for export were 9% of total Canadian refinery throughput. Exports of aviation turbine fuel from Ontario began in April 1987. The top single exporter in Canada was Irving Oil Ltd. with 2,485,000 m3. Irving was also the top exporter in 1986. 11 figs., 4 tabs

  9. 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...

  10. 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 ...

  11. 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

  12. 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…

  13. 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

  14. 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...

  15. 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 ...

  16. 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)

  17. 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.

  18. Gas Exports in Turkmenistan

    International Nuclear Information System (INIS)

    The Caspian region has been at the center of attention since Europe began seeking alternative routes to natural-gas resources. Turkmenistan has the potential to become an important gas exporter to Europe. As a landlocked country, Turkmenistan until recently has relied on post-Soviet pipeline infrastructures. The Central Asian republic has been at the mercy of Moscow's energy policy, which overlaps its foreign policy. At the same time, the revenue from gas exports is an essential part of the Turkmen national budget. This prompted Ashgabat to look for energy partners bypassing Russian territories. It started to convey natural gas first to Iran and then to China. This gave Turkmenistan strong leverage vis-a-vis Moscow. Ashgabat has not decided to export every gas molecule eastward, but, in jeopardizing its relations with Moscow, it expects more than empty pledges from Europe. On the other hand, a simple question emerges: Does Europe really need alternative sources? The answer is in the hands of Gazprom and Russian policy-makers

  19. An Interaction between KSHV ORF57 and UIF Provides mRNA-Adaptor Redundancy in Herpesvirus Intronless mRNA Export

    OpenAIRE

    Jackson, Brian R.; Boyne, James R.; Marko Noerenberg; Adam Taylor; Hautbergue, Guillaume M.; Walsh, Matthew J; Rachel Wheat; Blackbourn, David J.; Wilson, Stuart A.; Adrian Whitehouse

    2011-01-01

    Author Summary Herpesviruses hijack cellular components to enhance viral gene expression. This is particularly important for the efficient nuclear export of herpesvirus intronless mRNAs to allow the production of viral proteins. We have previously demonstrated that Kaposi's sarcoma-associated herpesvirus encodes a conserved protein, ORF57, which recruits essential cellular mRNA export proteins onto the viral intronless mRNAs to form an export competent viral ribonucleoprotein particle. Specif...

  20. Maintaining cholesterol homeostasis:Sterol regulatory element-binding proteins

    Institute of Scientific and Technical Information of China (English)

    Lutz W. Weber; Meinrad Boll; Andreas Stampfl

    2004-01-01

    The molecular mechanism of how hepatocytes maintain cholesterol homeostasis has become much more transparent with the discovery of sterol regulatory element binding proteins (SREBPs) in recent years. These membrane proteins are members of the basic helix-loop-helix-leucine zipper (bHLHZip) family of transcription factors. They activate the expression of at least 30 genes involved in the synthesis of cholesterol and lipids. SREBPs are synthesized as precursor proteins in the endoplasmic reticulum (ER), where they form a complex with another protein, SREBP cleavage activating protein (SCAP).The SCAP molecule contains a sterol sensory domain. In the presence of high cellular sterol concentrations SCAP confines SREBP to the ER. With low cellular concentrations, SCAP escorts SREBP to activation in the Golgi. There, SREBP undergoes two proteolytic cleavage steps to release the mature, biologically active transcription factor, nuclear SREBP (nSREBP). nSREBP translocates to the nucleus and binds to sterol response elements (SRE) in the promoter/enhancer regions of target genes. Additional transcription factors are required to activate transcription of these genes. Three different SREBPs are known, SREBPs-1a, -1c and -2. SREBP-1a and -1c are isoforms produced from a single gene by alternate splicing. SREBP-2is encoded by a different gene and does not display any isoforms. It appears that SREBPs alone, in the sequence described above, can exert complete control over cholesterol synthesis, whereas many additional factors (hormones,cytokines, etc.) are required for complete control of lipid metabolism. Medicinal manipulation of the SREBP/SCAP system is expected to prove highly beneficial in the management of cholesterol-related disease.

  1. 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.

  2. 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

  3. 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

  4. Risk Taking Propensity and Export Performance of Croatian Exporters

    Directory of Open Access Journals (Sweden)

    Mirna Leko-Simic

    2006-12-01

    Full Text Available Export performance is today one of the most widely used measures of a company’s success, due to the globalization and market liberalization processes. The rather bad export performance of Croatian exporters can be explained by a number of factors, one of which is assumed to be the low level of risk taking propensity, which is one of the three major dimensions of entrepreneurial behavior. The aim of this paper is to analyze company age, size and type of business as determinants of risk taking propensity in Croatian exporting companies. Cluster analysis based on four variable criteria was used in order to determine risk and non-risk takers’ clusters and analyze the significant differences between them in relation to their export performance. The paper is based on research of 88 Croatian exporters.

  5. 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...

  6. 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.

  7. 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.

  8. Examining the role of export competitive advantages on export performance

    OpenAIRE

    Yeganeh Alimohammadi; Reza Aghamousa; Fataneh Alizadeh Meshkani

    2014-01-01

    This paper investigates the role of export competitive advantage on export performance in food industry. The proposed study designs a questionnaire in Likert scale and distributes it among 280 randomly selected experts in food industry and Cronbach alpha has been calculated as 0.827. The study has applied factor analysis to find important factors influencing export performance. Kaiser-Meyer-Olkin Measure of Sampling Adequacy and Bartlett's Test of Sphericity have been performed to validate th...

  9. Voluntary export restraints and resource allocation in exporting countries

    OpenAIRE

    De Melo, Jaime; WINTERS, L Alan

    1990-01-01

    Most literature on voluntary export restraints ( VERs ) analyzes the welfare costs of VERs to consumers in the importing country. The authors propose a method for measuring the effects of a VER on the productivity of factors employed in the exporting industry. Their model measures how a VER affects both revenues and efficiency in an exporting industry. They used the model to estimate the effects of the U.S. Orderly Marketing Agreement ( OMA ) on Korean producers of leather footwear ( 1977 - 8...

  10. 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...

  11. An Anatomy Of The Export Expansion Process

    OpenAIRE

    Reid, S

    1986-01-01

    This paper examines the export market strategies and export modes used by small and medium sized Italian manufacturing firms. The firms vary extensively in their extent and type of export dependence on different channel arrangements and export markets. Moreover, the exporting modes used do show some peculiar links with export objectives specifically higher dependence on direct sales is associated with planned export expansion and higher dependence on agent/representatives and distributors is ...

  12. Export policy of the Czech Republic

    OpenAIRE

    Tomišková, Dominika

    2009-01-01

    This thesis focuses on the export policy of the Czech Republic. It describes the Export strategy of the Czech Republic for 2012--2020 and covers a number of institutions that currently support Czech exporters. The thesis includes a review of the export policy of Slovakia and its comparison with the current Czech export policy. In conclusion, pros and cons of the Czech export policy are highlighted. There are also suggestions to improve the Czech export support in the future.

  13. Managerial and learning skills in exporting SMEs

    OpenAIRE

    RUBÉN FERNÁNDEZ ORTIZ; JOSÉ IGNACIO CASTRESANA RUIZ-CARRILLO

    2005-01-01

    The relevance of the perception of exports in the field of business management can have a key impact on the exporting behavior of SMEs. In particular, it can determine the decision to implement an export policy, as well as the policies applied to consolidate exports. This paper covers two main aspects. First, the extent to which managerial perceptions of exports affect the decision to export, and second, for these SMEs which are already exporters, we study the managerial perceptions that can ...

  14. Phospholipid liposomes acquire apolipoprotein E in atherogenic plasma and block cholesterol loading of cultured macrophages.

    OpenAIRE

    Williams, K J; Tall, A.R.; Bisgaier, C; Brocia, R

    1987-01-01

    A single infusion of phospholipid liposomes promptly and persistently abolished the ability of hypercholesterolemic rabbit plasma to cause cholesteryl ester loading in cultured macrophages. This phospholipid enrichment of plasma caused moderate stimulation of cellular cholesterol efflux and, unexpectedly, almost complete inhibition of cellular uptake of beta-very low density lipoprotein (beta-VLDL), the major cholesteryl ester-rich particle in hypercholesterolemic rabbit plasma. Cell viabilit...

  15. Lysosomal acid lipase: At the crossroads of normal and atherogenic cholesterol metabolism

    Directory of Open Access Journals (Sweden)

    Joshua A Dubland

    2015-02-01

    Full Text Available Unregulated cellular uptake of apolipoprotein B-containing lipoproteins in the arterial intima leads to the formation of foam cells in atherosclerosis. Lysosomal acid lipase (LAL plays a crucial role in both lipoprotein lipid catabolism and excess lipid accumulation as it is the primary enzyme that hydrolyzes cholesteryl esters derived from both low density lipoprotein (LDL and modified forms of LDL. Evidence suggests that as atherosclerosis progresses, accumulation of excess free cholesterol in lysosomes leads to impairment of LAL activity, resulting in accumulation of cholesteryl esters in the lysosome as well as the cytosol in foam cells. Impaired metabolism and release of cholesterol from lysosomes can lead to downstream defects in ATP-binding cassette transporter A1 regulation, needed to offload excess cholesterol from plaque foam cells. This review focuses on the role LAL plays in normal cholesterol metabolism and how the associated changes in its enzymatic activity may ultimately contribute to atherosclerosis progression.

  16. 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.

  17. China's Export Expansion, Export Structure and Energy Consumption

    Institute of Scientific and Technical Information of China (English)

    Lan Yisheng; Ning Xuemin

    2011-01-01

    Since the reform and opening up, China's export trade has maintained a rapid growth; meanwhile, China's energy consumption has been increasing sharply. "High export and high energy consumption" has become the feature of China's trade and economic development. In this paper, based on the input-output analysis approach, the authors have conducted an empirical study on the export trade and energy consumption of 21 trade industrial sectors. The results show that, China is a big net exporter of embodied energy. Assuming that the export growth rate of embodied energy maintains to be about 23.6%, the average annual growth rate of the past 32 years, and based on the input-output data of 2005, by 2030 China's net export of embodied energy would be over eight times more than the aggregate energy production, which is obviously infeasible. As a country of very low per capita en- ergy, China must change its export pattern, encourage or restrain the export of different industrial sectors according to their energy consumption intensity, and promote structural change of energy- efficient exported products, so as to achieve the sustainable development. Accordingly, the authors put forward some suggestions.

  18. Fluorescent Sterols and Cholesteryl Esters as Probes for Intracellular Cholesterol Transport

    Science.gov (United States)

    Solanko, Katarzyna A.; Modzel, Maciej; Solanko, Lukasz M.; Wüstner, Daniel

    2015-01-01

    Cholesterol transport between cellular organelles comprised vesicular trafficking and nonvesicular exchange; these processes are often studied by quantitative fluorescence microscopy. A major challenge for using this approach is producing analogs of cholesterol with suitable brightness and structural and chemical properties comparable with those of cholesterol. This review surveys currently used fluorescent sterols with respect to their behavior in model membranes, their photophysical properties, as well as their transport and metabolism in cells. In the first part, several intrinsically fluorescent sterols, such as dehydroergosterol or cholestatrienol, are discussed. These polyene sterols (P-sterols) contain three conjugated double bonds in the steroid ring system, giving them slight fluorescence in ultraviolet light. We discuss the properties of P-sterols relative to cholesterol, outline their chemical synthesis, and explain how to image them in living cells and organisms. In particular, we show that P-sterol esters inserted into low-density lipoprotein can be tracked in the fibroblasts of Niemann–Pick disease using high-resolution deconvolution microscopy. We also describe fluorophore-tagged cholesterol probes, such as BODIPY-, NBD-, Dansyl-, or Pyrene-tagged cholesterol, and eventual esters of these analogs. Finally, we survey the latest developments in the synthesis and use of alkyne cholesterol analogs to be labeled with fluorophores by click chemistry and discuss the potential of all approaches for future applications. PMID:27330304

  19. Fluorescent Sterols and Cholesteryl Esters as Probes for Intracellular Cholesterol Transport.

    Science.gov (United States)

    Solanko, Katarzyna A; Modzel, Maciej; Solanko, Lukasz M; Wüstner, Daniel

    2015-01-01

    Cholesterol transport between cellular organelles comprised vesicular trafficking and nonvesicular exchange; these processes are often studied by quantitative fluorescence microscopy. A major challenge for using this approach is producing analogs of cholesterol with suitable brightness and structural and chemical properties comparable with those of cholesterol. This review surveys currently used fluorescent sterols with respect to their behavior in model membranes, their photophysical properties, as well as their transport and metabolism in cells. In the first part, several intrinsically fluorescent sterols, such as dehydroergosterol or cholestatrienol, are discussed. These polyene sterols (P-sterols) contain three conjugated double bonds in the steroid ring system, giving them slight fluorescence in ultraviolet light. We discuss the properties of P-sterols relative to cholesterol, outline their chemical synthesis, and explain how to image them in living cells and organisms. In particular, we show that P-sterol esters inserted into low-density lipoprotein can be tracked in the fibroblasts of Niemann-Pick disease using high-resolution deconvolution microscopy. We also describe fluorophore-tagged cholesterol probes, such as BODIPY-, NBD-, Dansyl-, or Pyrene-tagged cholesterol, and eventual esters of these analogs. Finally, we survey the latest developments in the synthesis and use of alkyne cholesterol analogs to be labeled with fluorophores by click chemistry and discuss the potential of all approaches for future applications. PMID:27330304

  20. Role of phospholipid transfer protein and pre beta-high density lipoproteins in maintaining cholesterol efflux from Fu5AH cells to plasma from insulin-resistant subjects

    NARCIS (Netherlands)

    Dullaart, RPF; Van Tol, A

    2001-01-01

    Plasma phospholipid transfer protein (PLTP) enhances the generation of pre beta -high density lipoproteins (HDL) that may act as initial accepters of cellular cholesterol, and are likely to play an important role in the antiatherogenic process of reverse cholesterol transport. We: examined the inter

  1. NEW APPROACHES TO EXPORT COMPETITIVENESS

    OpenAIRE

    Alina Petronela NEGREA

    2015-01-01

    The economic literature and the political discourse typically look at international competitiveness mainly by the means of export market shares. However, globalisation, production fragmentation and the growing importance of global value chains (GVCs) increasingly challenge traditional approaches of export competitiveness and call for a more accurate and disaggregated level of analysis. Due to the growing fragmentation of production, a country exports now include a significant amount of import...

  2. Slowed Exports Growth

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The first half of 2010 is showing that the impacts of the financial crisis are still lingering.Zhao Jinping,a researcher at the Development Research Center of the State Council,says that the possible implementation of exit strategies in developed countries may deal a heavy blow to a global rally,and it will certainly result in slowed exports growth for China.Zhao published his opinion in the China Economic Times.The first part was published in issue No.33.Edited excerpts of the second part follow:

  3. Soviet energy export prospects

    Energy Technology Data Exchange (ETDEWEB)

    Scanlan, Tony

    1991-05-01

    The Soviet Union produces 20% of world energy but since 1988 this is in decline. Awakening consumerism and a sea-change in the structure of foreign trade and internal investment are placing this key industry into unprecedented uncertainty. The difference between success and failure goes beyond the 1988 peak of six million barrels daily of exports in oil equivalent. The article quantifies the key areas of energy uncertainty as equal in volume to total OPEC output and sees the long-term changes of success more than ever dependent on coordinated planning and investment as well as on market reality. (Author).

  4. Exports of petroleum products, 1988

    International Nuclear Information System (INIS)

    A summary is presented of exports of motor gasoline, middle distillate, aviation turbine fuel, heavy fuel oil, and partially processed oil from Canada for the 1988 calendar year. A discussion of petroleum product imports is included in order to put exports in the context of the overall trade. Exports of the above petroleum products averaged 32,000 m3/d in 1988, up 44% from 1987 levels. Each product except aviation fuel registered increases in export volumes, which reached the highest total volume of the decade. The main reason for the large increase was the first full year of production from the export-directed refinery at Come By Chance, Newfoundland. Export prices for light petroleum products stayed relatively close to USA spot prices. The heavy fuel oil price was mostly above the USA east coast spot price during 1988. Attractive prices on the USA east coast resulted in a few cargoes of middle distillate and motor gasoline shipped from British Columbia. Petroleum products imports came from 12 countries; Quebec had the largest volume of imports in 1988. The USA remained Canada's largest trading partner in petroleum products. Western exporters view the Far East as an ongoing important market. The top single exporter in Canada was Newfoundland Processing, with 32% of the total export volume. 12 figs., 3 tabs

  5. India’s Services Exports

    OpenAIRE

    Markus Hyvonen; Hao Wang

    2012-01-01

    Exports of services are an important source of demand for the Indian economy and account for a larger share of output than in most major economies. The importance of India’s services exports mirrors that of the broader services sector in India, which is large compared with other countries at a similar stage of development. This article provides an overview of India’s services exports, focusing on their composition and destination, and discusses some of the reasons why services exports are so ...

  6. Export base of czech regions

    OpenAIRE

    Michal Šulc

    2010-01-01

    This article deals with the analysis of structure and size of goods exported from the Czech regions in the period of 2003–2009. The analysis is related to the export base theory. At first there is the export base theory characterised in the beginning of the article. There is a limited data base for the assessing of international flow of goods and services in case of Czech regions, for only the data of exported goods is regionally monitored. Both the presence and the increase of importance of ...

  7. Liver receptor homolog 1 transcriptionally regulates human bile salt export pump expression*

    OpenAIRE

    Song, Xiulong; Kaimal, Rajani; Yan, Bingfang; Deng, Ruitang

    2008-01-01

    The metabolic conversion of cholesterol into bile acids in liver is initiated by the rate-limiting cholesterol 7α-hydroxylase (CYP7A1), whereas the bile salt export pump (BSEP) is responsible for the canalicular secretion of bile acids. Liver receptor homolog 1 (LRH-1) is a key transcriptional factor required for the hepatic expression of CYP7A1. We hypothesized that LRH-1 was also involved in the transcriptional regulation of BSEP. In support of our hypothesis, we found that overexpression o...

  8. 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

  9. Sort1, encoded by the cardiovascular risk locus 1p13.3, is a regulator of hepatic lipoprotein export

    DEFF Research Database (Denmark)

    Kjølby, Mads Fuglsang; Andersen, Olav Michael; Breiderhoff, Tilman;

    2010-01-01

    receptor for apolipoprotein (apo) B100. It interacts with apoB100 in the Golgi and facilitates the formation and hepatic export of apoB100-containing lipoproteins, thereby regulating plasma low-density lipoprotein (LDL) cholesterol. Absence of sortilin in gene-targeted mice reduces secretion...

  10. The mechanism of increased biliary lipid secretion in mice with genetic inactivation of bile salt export pump

    NARCIS (Netherlands)

    Gooijert, K. E. R.; Havinga, R.; Wolters, Henk; Wang, R.; Ling, V.; Tazuma, S.; Verkade, H. J.

    2015-01-01

    Human bile salt export pump (BSEP) mutations underlie progressive familial intrahepatic cholestasis type 2 (PFIC2). In the PFIC2 animal model, Bsep(-/-) mice, biliary secretion of bile salts (BS) is decreased, but that of phospholipids (PL) and cholesterol (CH) is increased. Under physiological cond

  11. Export incentives, exchange rate policy and export growth in Turkey

    NARCIS (Netherlands)

    S.J.G. van Wijnbergen; I. Arslan

    1993-01-01

    The driving forces behind the Turkish export miracle, and in fact its very existence, have remained a matter of debate We show there was a boom. As to contributing factors, import growth in the Middle East in excess of import growth elsewhere made a negative contribution. On exports to non-oil count

  12. Stable assembly of HIV-1 export complexes occurs cotranscriptionally

    DEFF Research Database (Denmark)

    Nawroth, Isabel; Mueller, Florian; Basyuk, Eugenia;

    2014-01-01

    The HIV-1 Rev protein mediates export of unspliced and singly spliced viral transcripts by binding to the Rev response element (RRE) and recruiting the cellular export factor CRM1. Here, we investigated the recruitment of Rev to the transcription sites of HIV-1 reporters that splice either post......- or cotranscriptionally. In both cases, we observed that Rev localized to the transcription sites of the reporters and recruited CRM1. Rev and CRM1 remained at the reporter transcription sites when cells were treated with the splicing inhibitor Spliceostatin A (SSA), showing that the proteins associate with RNA prior...... to or during early spliceosome assembly. Fluorescence recovery after photobleaching (FRAP) revealed that Rev and CRM1 have similar kinetics as the HIV-1 RNA, indicating that Rev, CRM1, and RRE-containing RNAs are released from the site of transcription in one single export complex. These results suggest...

  13. Wind exports markets

    International Nuclear Information System (INIS)

    This paper presents the situation of wind export markets and the principles of firming, shaping and moving. Firming means the conversion of uncertain second to second output into hourly deliveries. Firming of energy is used to make up the difference between the hourly schedule and actual output. Firming of capacity is setting aside generation to stand behind fluctuations in wind output within the hour. Shaping is to convert uncertain hour-to-hour output throughout the year into predetermined deliveries that meet consumer demand. Moving refers to BC's attempts to bring about the transport of clean energy to California. But there are transmission issues involved because the network lines to California are already fully subscribed. One solution would be for IPPs to purchase services from Powerex, or any other service provider, at opportunity cost. Another element is that the market price for wholesale electricity is lower than in recent years. It is safe to say that there are lots of uncertainties involved in wind exports.

  14. 9-cis β-Carotene Increased Cholesterol Efflux to HDL in Macrophages

    Directory of Open Access Journals (Sweden)

    Sapir Bechor

    2016-07-01

    Full Text Available Cholesterol efflux from macrophages is a key process in reverse cholesterol transport and, therefore, might inhibit atherogenesis. 9-cis-β-carotene (9-cis-βc is a precursor for 9-cis-retinoic-acid (9-cis-RA, which regulates macrophage cholesterol efflux. Our objective was to assess whether 9-cis-βc increases macrophage cholesterol efflux and induces the expression of cholesterol transporters. Enrichment of a mouse diet with βc from the alga Dunaliella led to βc accumulation in peritoneal macrophages. 9-cis-βc increased the mRNA levels of CYP26B1, an enzyme that regulates RA cellular levels, indicating the formation of RA from βc in RAW264.7 macrophages. Furthermore, 9-cis-βc, as well as all-trans-βc, significantly increased cholesterol efflux to high-density lipoprotein (HDL by 50% in RAW264.7 macrophages. Likewise, food fortification with 9-cis-βc augmented cholesterol efflux from macrophages ex vivo. 9-cis-βc increased both the mRNA and protein levels of ABCA1 and apolipoprotein E (APOE and the mRNA level of ABCG1. Our study shows, for the first time, that 9-cis-βc from the diet accumulates in peritoneal macrophages and increases cholesterol efflux to HDL. These effects might be ascribed to transcriptional induction of ABCA1, ABCG1, and APOE. These results highlight the beneficial effect of βc in inhibition of atherosclerosis by improving cholesterol efflux from macrophages.

  15. 9-cis β-Carotene Increased Cholesterol Efflux to HDL in Macrophages

    Science.gov (United States)

    Bechor, Sapir; Zolberg Relevy, Noa; Harari, Ayelet; Almog, Tal; Kamari, Yehuda; Ben-Amotz, Ami; Harats, Dror; Shaish, Aviv

    2016-01-01

    Cholesterol efflux from macrophages is a key process in reverse cholesterol transport and, therefore, might inhibit atherogenesis. 9-cis-β-carotene (9-cis-βc) is a precursor for 9-cis-retinoic-acid (9-cis-RA), which regulates macrophage cholesterol efflux. Our objective was to assess whether 9-cis-βc increases macrophage cholesterol efflux and induces the expression of cholesterol transporters. Enrichment of a mouse diet with βc from the alga Dunaliella led to βc accumulation in peritoneal macrophages. 9-cis-βc increased the mRNA levels of CYP26B1, an enzyme that regulates RA cellular levels, indicating the formation of RA from βc in RAW264.7 macrophages. Furthermore, 9-cis-βc, as well as all-trans-βc, significantly increased cholesterol efflux to high-density lipoprotein (HDL) by 50% in RAW264.7 macrophages. Likewise, food fortification with 9-cis-βc augmented cholesterol efflux from macrophages ex vivo. 9-cis-βc increased both the mRNA and protein levels of ABCA1 and apolipoprotein E (APOE) and the mRNA level of ABCG1. Our study shows, for the first time, that 9-cis-βc from the diet accumulates in peritoneal macrophages and increases cholesterol efflux to HDL. These effects might be ascribed to transcriptional induction of ABCA1, ABCG1, and APOE. These results highlight the beneficial effect of βc in inhibition of atherosclerosis by improving cholesterol efflux from macrophages. PMID:27447665

  16. Insurability of export credit risks

    NARCIS (Netherlands)

    Alsem, K.J.; Antufjew, J.; Huizingh, K.R.E.; Koning, Ruud H.; Sterken, E.; Woltil, M.

    2003-01-01

    Firms exporting their goods and services abroad face risks that are different from the risks faced by firms who do not engage in international trade. It is common practice to allow the receiving party to pay in instalments. The exporting firm faces credit risk, but as in most countries, Dutch firms

  17. Tumbling Auto Import and Export

    Institute of Scientific and Technical Information of China (English)

    Yantai Chen

    2009-01-01

    @@ The seemingly rebound global financial crisis has seriously eroded world economy from 2008,of which China's tumbling auto imports and exports business is a good example.At the beginning of 2008 it kicked off as an excellent year for the Chinese automotive market,but ended with the onset of a recession in last quarter both from the perspective of import and export.

  18. Sinosure Helping to Stabilize Exports

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The unfolding international financial crisis is taking its toll on China’s economy, especially China’s exports. On one hand, overseas demand has plummeted, while on the other, with the worsening credit environment and emerging trade protectionism, export enter-prises are suffering from rising credit risks, to the point where some of them dare not even accept orders.

  19. 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...

  20. 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

  1. NEW APPROACHES TO EXPORT COMPETITIVENESS

    Directory of Open Access Journals (Sweden)

    Alina Petronela NEGREA

    2015-04-01

    Full Text Available The economic literature and the political discourse typically look at international competitiveness mainly by the means of export market shares. However, globalisation, production fragmentation and the growing importance of global value chains (GVCs increasingly challenge traditional approaches of export competitiveness and call for a more accurate and disaggregated level of analysis. Due to the growing fragmentation of production, a country exports now include a significant amount of imports of intermediate goods which are part of the export value. In this case, a simple analysis of the evolution of exports can distort the international competitive position of a country. The article suggests a new approach based on the value-added content of international trade measured by means of global value chain analysis.

  2. Cellular uptake of steroid carrier proteins – mechanisms and implications

    OpenAIRE

    Willnow, T E; Nykjaer, A

    2009-01-01

    Abstract Steroid hormones are believed to enter cells solely by free diffusion through the plasma membrane. However, recent studies suggest the existence of cellular uptake pathways for carrier-bound steroids. Similar to the clearance of cholesterol via lipoproteins, these pathways involve the recognition of carrier proteins by endocytic receptors on the surface of target cells, followed by internalization and cellular delivery of the bound sterols. Here, we discuss the emerging co...

  3. Murine Leukemia Virus Uses TREX Components for Efficient Nuclear Export of Unspliced Viral Transcripts

    Directory of Open Access Journals (Sweden)

    Toshie Sakuma

    2014-03-01

    Full Text Available Previously we reported that nuclear export of both unspliced and spliced murine leukemia virus (MLV transcripts depends on the nuclear export factor (NXF1 pathway. Although the mRNA export complex TREX, which contains Aly/REF, UAP56, and the THO complex, is involved in the NXF1-mediated nuclear export of cellular mRNAs, its contribution to the export of MLV mRNA transcripts remains poorly understood. Here, we studied the involvement of TREX components in the export of MLV transcripts. Depletion of UAP56, but not Aly/REF, reduced the level of both unspliced and spliced viral transcripts in the cytoplasm. Interestingly, depletion of THO components, including THOC5 and THOC7, affected only unspliced viral transcripts in the cytoplasm. Moreover, the RNA immunoprecipitation assay showed that only the unspliced viral transcript interacted with THOC5. These results imply that MLV requires UAP56, THOC5 and THOC7, in addition to NXF1, for nuclear export of viral transcripts. Given that naturally intronless mRNAs, but not bulk mRNAs, require THOC5 for nuclear export, it is plausible that THOC5 plays a key role in the export of unspliced MLV transcripts.

  4. Nuclear Imprisonment: Viral Strategies to Arrest Host mRNA Nuclear Export

    Directory of Open Access Journals (Sweden)

    Beatriz M. A. Fontoura

    2013-07-01

    Full Text Available Viruses possess many strategies to impair host cellular responses to infection. Nuclear export of host messenger RNAs (mRNA that encode antiviral factors is critical for antiviral protein production and control of viral infections. Several viruses have evolved sophisticated strategies to inhibit nuclear export of host mRNAs, including targeting mRNA export factors and nucleoporins to compromise their roles in nucleo-cytoplasmic trafficking of cellular mRNA. Here, we present a review of research focused on suppression of host mRNA nuclear export by viruses, including influenza A virus and vesicular stomatitis virus, and the impact of this viral suppression on host antiviral responses.

  5. Mexico: Imports or exports?

    International Nuclear Information System (INIS)

    This presentation provides an overview of Mexico's energy sector. Proven oil reserves place Mexico in ninth position in the world and fourth largest in natural gas reserves. Energy is one of the most important economic activities of the country, representing 3 per cent of Gross Domestic Product (GDP). Oil exports represent 8.4 per cent of total exports. Approximately 40 per cent of total public investment is earmarked for energy projects. The author discusses energy resources and energy sector limitations. The energy sector plan for the period 2001-2006 is discussed. Its goals are to ensure energy supply, to develop the energy sector, to stimulate participation of Mexican enterprises, to promote renewable energy sources, and to strengthen international energy cooperation. The regulatory framework is being adapted to increase private investment. Some graphs are presented, displaying the primary energy production and primary energy consumption. Energy sector reforms are reviewed, as are electricity and natural gas reforms. The energy sector demand for 2000-2010 and investment requirements are reviewed, as well as fuel consumption for power generation. The author discusses the National Pipeline System (SNG) and the bottlenecks caused by pressure efficiency in the northeast, flow restriction on several pipeline segments, variability of the Petroleos Mexicanos (PEMEX) own use, and pressure drop on central regions. The entire prospect for natural gas in the country is reviewed, along with the Strategic Gas Program (PEG) consisting of 20 projects, including 4 non-associated natural gas, 9 exploration and 7 optimization. A section dealing with multiple service contracts is included in the presentation. The authors conclude by stating that the priority is a national energy policy to address Mexico's energy security requirements, to increase natural gas production while promoting the diversification of imports, and a regulatory framework to be updated in light of current

  6. YeeO from Escherichia coli exports flavins.

    Science.gov (United States)

    McAnulty, Michael J; Wood, Thomas K

    2014-01-01

    Multidrug and toxic compound extrusion (MATE) proteins help maintain cellular homeostasis by secreting metabolic wastes. Flavins may occur as cellular waste products, with their production and secretion providing potential benefit for industrial applications related to biofuel cells. Here we find that MATE protein YeeO from Escherichia coli exports both flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). Significant amounts of flavins were trapped intracellularly when YeeO was produced indicating transport limits secretion of flavins. Wild-type E. coli secreted 3 flavins (riboflavin, FMN, and FAD), so E. coli likely produces additional flavin transporters. PMID:25482085

  7. 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...

  8. 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,...

  9. 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 ...

  10. Examining the role of export competitive advantages on export performance

    Directory of Open Access Journals (Sweden)

    Yeganeh Alimohammadi

    2014-04-01

    Full Text Available This paper investigates the role of export competitive advantage on export performance in food industry. The proposed study designs a questionnaire in Likert scale and distributes it among 280 randomly selected experts in food industry and Cronbach alpha has been calculated as 0.827. The study has applied factor analysis to find important factors influencing export performance. Kaiser-Meyer-Olkin Measure of Sampling Adequacy and Bartlett's Test of Sphericity have been performed to validate the results and they both validated the questionnaire. The results of the survey have determined six effective groups including product development, e-commerce, marketing planning, organizational performance, competitiveness and supply chain management.

  11. 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

  12. 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

  13. 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

  14. Proteasome inhibitors attenuated cholesterol-induced cardiac hypertrophy in H9c2 cells

    Science.gov (United States)

    Lee, Hyunjung; Park, Jinyoung; Kim, Eunice EunKyeong; Yoo, Young Sook; Song, Eun Joo

    2016-01-01

    The Ubiquitin proteasome system (UPS) plays roles in protein degradation, cell cycle control, and growth and inflammatory cell signaling. Dysfunction of UPS in cardiac diseases has been seen in many studies. Cholesterol acts as an inducer of cardiac hypertrophy. In this study, the effect of proteasome inhibitors on the cholesterol-induced hypertrophic growth in H9c2 cells is examined in order to observe whether UPS is involved in cardiac hypertrophy. The treatment of proteasome inhibitors MG132 and Bortezomib markedly reduced cellular surface area and mRNA expression of β-MHC in cholesterol-induced cardiac hypertrophy. In addition, activated AKT and ERK were significantly attenuated by MG132 and Bortezomib in cholesterol-induced cardiac hypertrophy. We demonstrated that cholesterol-induced cardiac hypertrophy was suppressed by proteasome inhibitors. Thus, regulatory mechanism of cholesterol-induced cardiac hypertrophy by proteasome inhibitors may provide a new therapeutic strategy to prevent the progression of heart failure. [BMB Reports 2016; 49(5): 270-275] PMID:26592933

  15. LDL Receptor-Related Protein-1 (LRP1 Regulates Cholesterol Accumulation in Macrophages.

    Directory of Open Access Journals (Sweden)

    Anna P Lillis

    Full Text Available Within the circulation, cholesterol is transported by lipoprotein particles and is taken up by cells when these particles associate with cellular receptors. In macrophages, excessive lipoprotein particle uptake leads to foam cell formation, which is an early event in the development of atherosclerosis. Currently, mechanisms responsible for foam cell formation are incompletely understood. To date, several macrophage receptors have been identified that contribute to the uptake of modified forms of lipoproteins leading to foam cell formation, but the in vivo contribution of the LDL receptor-related protein 1 (LRP1 to this process is not known [corrected]. To investigate the role of LRP1 in cholesterol accumulation in macrophages, we generated mice with a selective deletion of LRP1 in macrophages on an LDL receptor (LDLR-deficient background (macLRP1-/-. After feeding mice a high fat diet for 11 weeks, peritoneal macrophages isolated from Lrp+/+ mice contained significantly higher levels of total cholesterol than those from macLRP1-/- mice. Further analysis revealed that this was due to increased levels of cholesterol esters. Interestingly, macLRP1-/- mice displayed elevated plasma cholesterol and triglyceride levels resulting from accumulation of large, triglyceride-rich lipoprotein particles in the circulation. This increase did not result from an increase in hepatic VLDL biosynthesis, but rather results from a defect in catabolism of triglyceride-rich lipoprotein particles in macLRP1-/- mice. These studies reveal an important in vivo contribution of macrophage LRP1 to cholesterol homeostasis.

  16. Cholesterol metabolism: increasingly complex; El metabolismo del colesterol: cada vez mas complejo

    Energy Technology Data Exchange (ETDEWEB)

    Sanhueza, J.; Valenzuela, R.; Valenzuela, A.

    2012-07-01

    Cholesterol is an important molecule; it is necessary for the biosynthesis of steroidal hormones, bile salts and to maintain the stability of biological membranes in animal cells. However, its excess is negative and is responsible for the development of many diseases involving the heart and brain, or in the generation of some types of cancer. For these reasons, the cellular cholesterol levels must be finely regulated and therefore, an infinite number of mechanisms participate in this regulation, which undertake the organism as a whole. These mechanisms should begin to operate efficiently from the intake of cholesterol from the diet, its incorporation into the enterocytes, where are involved carriers such as ABC and NCP1 transporters, PDZ structural motif, to name a few. It is also necessary an adequate regulation of circulating cholesterol and once inside the body, there should be a perfect harmony between the addition of cholesterol to various tissues, its metabolic use, the mechanisms of its tissue deposition, and the synthesis of this lipid. From this perspective, this review offers a general view of the molecular mechanisms that allow the regulation of extra and intracellular cholesterol levels. (Author) 82 refs.

  17. In vitro delivery of curcumin with cholesterol-based cationic liposomes.

    Science.gov (United States)

    Apiratikul, N; Penglong, T; Suksen, K; Svasti, S; Chairoungdua, A; Yingyongnarongkula, B

    2013-01-01

    A new cholesterol-based cationic lipid was synthesized; liposomes prepared on its basis were evaluated as drug delivery vehicles for curcumin. Free and liposome-encapsulated curcumin cytotoxicity against HeLa, A549, HepG2, K562 and 1301 cell lines was assessed. Liposomal curcumin with ED50 values ranging from 2.5-10 microM exhibited 2-8 times higher cytotoxicity than free curcumin. The synthetic cholesterol-based cationic lipid also enhanced cellular uptake of curcumin into tested cells. Cationic liposome alone showed low cytotoxicity at high doses with ED50 values of 90-210 microM.

  18. Learning to export and learning by exporting: The case of Ethiopian manufacturing

    OpenAIRE

    Siba, Eyerusalem; GEBREEYESUS, Mulu

    2014-01-01

    In this study, we investigate the relationship between exporting and firm performance using a longer panel dataset of Ethiopian manufacturing firms for the period 1996 - 2009. We test two hypotheses regarding exporting: selection into exporting versus learning by exporting. According to the selection into exporting hypothesis, more productive firms self-select into exporting due to high entry costs. The learning by exporting hypothesis, on the other hand, emphasizes that firms learn after ent...

  19. 2006 Rare Earth Export Quota

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ According to correlative stipulations in "Goods Import εt Export Administrating Statute of P.R.C", 2006export quota for important industrial products was issued by the Ministry of Commerce of P.R.C. on December 30th of 2005. Export quota of rare earth products is 45,000 tons. It is said the quota will be distributed in two batches. The first batch of quota will reach 70-80% of the total with 21,700 - 24,800tons for domestic companies and 10,500 - 12,000 tons for foreign invested companies. Quota will be distributed to relevant enterprises directly in recent days.

  20. 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 ...

  1. 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

  2. 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

  3. 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

  4. Cellular compartmentalization of secondary metabolism

    Directory of Open Access Journals (Sweden)

    H. Corby eKistler

    2015-02-01

    Full Text Available Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors shared with the most essential processes of the cell (e.g. amino acids, acetyl CoA, NADPH, enzymes for secondary metabolite synthesis are compartmentalized at conserved subcellular sites that position pathway enzymes to use these common biochemical precursors. Co-compartmentalization of secondary metabolism pathway enzymes also may function to channel precursors, promote pathway efficiency and sequester pathway intermediates and products from the rest of the cell. In this review we discuss the compartmentalization of three well-studied fungal secondary metabolite biosynthetic pathways for penicillin G, aflatoxin and deoxynivalenol, and summarize evidence used to infer subcellular localization. We also discuss how these metabolites potentially are trafficked within the cell and may be exported.

  5. 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.

  6. 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...

  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. β-Cyclodextrins Decrease Cholesterol Release and ABC-Associated Transporter Expression in Smooth Muscle Cells and Aortic Endothelial Cells

    Science.gov (United States)

    Coisne, Caroline; Hallier-Vanuxeem, Dorothée; Boucau, Marie-Christine; Hachani, Johan; Tilloy, Sébastien; Bricout, Hervé; Monflier, Eric; Wils, Daniel; Serpelloni, Michel; Parissaux, Xavier; Fenart, Laurence; Gosselet, Fabien

    2016-01-01

    Atherosclerosis is an inflammatory disease that leads to an aberrant accumulation of cholesterol in vessel walls forming atherosclerotic plaques. During this process, the mechanism regulating complex cellular cholesterol pools defined as the reverse cholesterol transport (RCT) is altered as well as expression and functionality of transporters involved in this process, namely ABCA1, ABCG1, and SR-BI. Macrophages, arterial endothelial and smooth muscle cells (SMCs) have been involved in the atherosclerotic plaque formation. As macrophages are widely described as the major cell type forming the foam cells by accumulating intracellular cholesterol, RCT alterations have been poorly studied at the arterial endothelial cell and SMC levels. Amongst the therapeutics tested to actively counteract cellular cholesterol accumulation, the methylated β-cyclodextrin, KLEPTOSE® CRYSMEβ, has recently shown promising effects on decreasing the atherosclerotic plaque size in atherosclerotic mouse models. Therefore we investigated in vitro the RCT process occurring in SMCs and in arterial endothelial cells (ABAE) as well as the ability of some modified β-CDs with different methylation degree to modify RCT in these cells. To this aim, cells were incubated in the presence of different methylated β-CDs, including KLEPTOSE® CRYSMEβ. Both cell types were shown to express basal levels of ABCA1 and SR-BI whereas ABCG1 was solely found in ABAE. Upon CD treatments, the percentage of membrane-extracted cholesterol correlated to the methylation degree of the CDs independently of the lipid composition of the cell membranes. Decreasing the cellular cholesterol content with CDs led to reduce the expression levels of ABCA1 and ABCG1. In addition, the cholesterol efflux to ApoA-I and HDL particles was significantly decreased suggesting that cells forming the blood vessel wall are able to counteract the CD-induced loss of cholesterol. Taken together, our observations suggest that methylated

  9. Clues to the mechanism of cholesterol transfer from the structure of NPC1 middle lumenal domain bound to NPC2.

    Science.gov (United States)

    Li, Xiaochun; Saha, Piyali; Li, Jian; Blobel, Günter; Pfeffer, Suzanne R

    2016-09-01

    Export of LDL-derived cholesterol from lysosomes requires the cooperation of the integral membrane protein Niemann-Pick C1 (NPC1) and a soluble protein, Niemann-Pick C2 (NPC2). Mutations in the genes encoding these proteins lead to Niemann-Pick disease type C (NPC). NPC2 binds to NPC1's second (middle), lumenally oriented domain (MLD) and transfers cholesterol to NPC1's N-terminal domain (NTD). Here, we report the 2.4-Å resolution crystal structure of a complex of human NPC1-MLD and NPC2 bearing bound cholesterol-3-O-sulfate. NPC1-MLD uses two protruding loops to bind NPC2, analogous to its interaction with the primed Ebola virus glycoprotein. Docking of the NPC1-NPC2 complex onto the full-length NPC1 structure reveals a direct cholesterol transfer tunnel between NPC2 and NTD cholesterol binding pockets, supporting the "hydrophobic hand-off" cholesterol transfer model. PMID:27551080

  10. Exports reflect "safety of products"

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Most of the made-in-China products are absolutely safe, and the steady increase in exports despite the recent widespread criticism reflects their safety standards, a Ministry of Commerce official said Thursday.

  11. ABCG5/ABCG8-independent biliary cholesterol excretion in lactating rats

    Science.gov (United States)

    Coy, Donna J.; Wooton-Kee, Clavia R.; Yan, Baoxiang; Sabeva, Nadezhda; Su, Kai; Graf, Gregory

    2010-01-01

    Lactation is associated with increased expression of bile acid transporters and an increased size and hydrophobicity of the bile acid pool in rats. ATP-binding cassette (ABC) transporters multidrug resistance protein 2 (Mdr2), Abcb11 [bile salt export pump (Bsep)], and Abcg5/Abcg8 heterodimers are essential for the biliary secretion of phospholipids, bile acids, and cholesterol, respectively. We investigated the expression of these transporters and secretion of their substrates in female control and lactating Sprague Dawley rats and C57BL/6 mice. Expression of Abcg5/Abcg8 mRNA was decreased by 97 and 60% by midlactation in rats and mice, respectively; protein levels of Abcg8 were below detection limits in lactating rats. Mdr2 mRNA expression was decreased in lactating rats and mice by 47 and 59%, respectively. Despite these changes in transporter expression, basal concentrations of cholesterol and phospholipid in bile were unchanged in rats and mice, whereas increased Bsep mRNA expression in early lactation coincided with an increased basal biliary bile acid concentration in lactating mice. Following taurocholate infusion, coupling of phospholipid and taurocholate secretion in bile of lactating mice was significantly impaired relative to control mice, with no significant changes in maximal secretion of cholesterol or bile acids. In rats, taurocholate infusion revealed a significantly impaired coupling of cholesterol to taurocholate secretion in bile in lactating vs. control animals. These data reveal marked utilization of an Abcg5/Abcg8-independent mechanism for basal biliary cholesterol secretion in rats during lactation, but a dependence on Abcg5/g8 for maximal biliary cholesterol secretion. PMID:20413720

  12. E-business and small Ghanaian exporters

    DEFF Research Database (Denmark)

    Hinson, Robert; Sørensen, Olav Jull

    2006-01-01

    The arfticle aims to investigate the relationship between export intensity and e-business adoption in Ghana. No clear relationship is found among exporters of non-traditional items.......The arfticle aims to investigate the relationship between export intensity and e-business adoption in Ghana. No clear relationship is found among exporters of non-traditional items....

  13. 31 CFR 592.304 - Exporting authority.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Exporting authority. 592.304 Section... § 592.304 Exporting authority. (a) The term exporting authority means one or more entities designated by a Participant from whose territory a shipment of rough diamonds is being exported as having...

  14. The dynamin chemical inhibitor dynasore impairs cholesterol trafficking and sterol-sensitive genes transcription in human HeLa cells and macrophages.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Girard

    Full Text Available Intracellular transport of cholesterol contributes to the regulation of cellular cholesterol homeostasis by mechanisms that are yet poorly defined. In this study, we characterized the impact of dynasore, a recently described drug that specifically inhibits the enzymatic activity of dynamin, a GTPase regulating receptor endocytosis and cholesterol trafficking. Dynasore strongly inhibited the uptake of low-density lipoprotein (LDL in HeLa cells, and to a lower extent in human macrophages. In both cell types, dynasore treatment led to the abnormal accumulation of LDL and free cholesterol (FC within the endolysosomal network. The measure of cholesterol esters (CE further showed that the delivery of regulatory cholesterol to the endoplasmic reticulum (ER was deficient. This resulted in the inhibition of the transcriptional control of the three major sterol-sensitive genes, sterol-regulatory element binding protein 2 (SREBP-2, 3-hydroxy-3-methyl-coenzymeA reductase (HMGCoAR, and low-density lipoprotein receptor (LDLR. The sequestration of cholesterol in the endolysosomal compartment impaired both the active and passive cholesterol efflux in HMDM. Our data further illustrate the importance of membrane trafficking in cholesterol homeostasis and validate dynasore as a new pharmacological tool to study the intracellular transport of cholesterol.

  15. 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 ...

  16. 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 ...

  17. Do Exporters Gain From VERs?

    OpenAIRE

    De Melo, Jaime; WINTERS, L Alan

    1990-01-01

    Previous literature has concentrated on the rent transfer accruing to exporting countries when a VER is binding. This paper studies the efficiency and distributional effects arising when VERs force factors out of industries in which they are most productive. A theoretical model of the industry under the VER is developed to establish qualitative conditions under which a VER will result in: spillovers of exports to unrestricted markets; industry contraction; and loss in national welfare. Key pa...

  18. Rising Threshold Shows Export Ambition

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Beginning from March 1 of this year,China only allows authorized manufacturers to engage in automobile exports in an effort to raise auto quality.The licensing system,jointly introduced by Ministry of Commerce,National Development and Reform Commission,General Administration of Customs,State Quality Inspection Administration and Certification and Accreditation Administration of China,aims to ensure that only large and credible auto manufacturers take part in auto exports.

  19. 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

  20. Exports of petroleum products, 1989

    International Nuclear Information System (INIS)

    A summary is presented of exports of motor gasoline, middle distillate, aviation turbine fuel, heavy fuel oil, and partially processed oil from Canada for the 1989 calendar year. A discussion of petroleum product imports is included in order to put exports in the context of the overall trade. Exports of the above petroleum products averaged 30,400 m3/d in 1989, down 5% from 1988 levels. Motor gasoline shipments showed the largest decrease, down 1,500 m3 to 7,700 m3/d. Export prices for light petroleum products stayed relatively close to USA spot prices except in June and July 1989, when attractive prices were obtained for shipments from the prairie provinces. The heavy fuel oil export price was similar to the USA east coast spot price in 1989, except in December. Canada's petroleum products imports in 1989 were 21,600 m3/d, compared to 18,400 m3/d in 1988. Imports of heavy fuel oil in eastern Canada rose 36% in 1989 because of industries switching from electricity and the high demand for thermal power generation. The USA remained Canada's largest trading partner in petroleum products. The top single exporter in 1989, as in 1988, was Newfoundland Processing, with a volume of 3,484,500 m3. 24 figs., 4 tabs

  1. BRAZILIAN EXPORTS OF MANUFACTURED WOOD

    Directory of Open Access Journals (Sweden)

    Rafael de Azevedo Calderon

    2010-08-01

    Full Text Available The present work deals with the Brazilian exports of sawnwood of non-coniferous, veneer sheets and plywood, from 1961 to 2002. The data regarding the three studied products, sawnwood of non-coniferous, veneer sheets and plywood, were joined through the method of Fisher so that an econometric evaluation of the market of the three products could be carried out. Supply and demand models of the Brazilian exports were specified. The results were satisfactory and they match with the literature. The supply of exports presented a positive answer in relation to the exporter's remuneration, to the production, to the use of the installed capacity (cycles of domestic economical activity and to the tendency, and negative in relation to the internal demand. The demand for the Brazilian exports was influenced positively by the world income, participation index and tendency, and negatively for the relative price. The low elasticity-price of the found demand can have implications in the conservation of the Brazilian forest resources because the exporters can increase the prices, reduce the amounts and still increase the incomes.

  2. Host cell P-glycoprotein is essential for cholesterol uptake and replication of Toxoplasma gondii.

    Science.gov (United States)

    Bottova, Iveta; Hehl, Adrian B; Stefanić, Sasa; Fabriàs, Gemma; Casas, Josefina; Schraner, Elisabeth; Pieters, Jean; Sonda, Sabrina

    2009-06-26

    P-glycoprotein (P-gp) is a membrane-bound efflux pump that actively exports a wide range of compounds from the cell and is associated with the phenomenon of multidrug resistance. However, the role of P-gp in normal physiological processes remains elusive. Using P-gp-deficient fibroblasts, we showed that P-gp was critical for the replication of the intracellular parasite Toxoplasma gondii but was not involved in invasion of host cells by the parasite. Importantly, we found that the protein participated in the transport of host-derived cholesterol to the intracellular parasite. T. gondii replication in P-gp-deficient host cells not only resulted in reduced cholesterol content in the parasite but also altered its sphingolipid metabolism. In addition, we found that different levels of P-gp expression modified the cholesterol metabolism in uninfected fibroblasts. Collectively our findings reveal a key and previously undocumented role of P-gp in host-parasite interaction and suggest a physiological role for P-gp in cholesterol trafficking in mammalian cells. PMID:19389707

  3. Host Cell P-glycoprotein Is Essential for Cholesterol Uptake and Replication of Toxoplasma gondii*

    Science.gov (United States)

    Bottova, Iveta; Hehl, Adrian B.; Štefanić, Saša; Fabriàs, Gemma; Casas, Josefina; Schraner, Elisabeth; Pieters, Jean; Sonda, Sabrina

    2009-01-01

    P-glycoprotein (P-gp) is a membrane-bound efflux pump that actively exports a wide range of compounds from the cell and is associated with the phenomenon of multidrug resistance. However, the role of P-gp in normal physiological processes remains elusive. Using P-gp-deficient fibroblasts, we showed that P-gp was critical for the replication of the intracellular parasite Toxoplasma gondii but was not involved in invasion of host cells by the parasite. Importantly, we found that the protein participated in the transport of host-derived cholesterol to the intracellular parasite. T. gondii replication in P-gp-deficient host cells not only resulted in reduced cholesterol content in the parasite but also altered its sphingolipid metabolism. In addition, we found that different levels of P-gp expression modified the cholesterol metabolism in uninfected fibroblasts. Collectively our findings reveal a key and previously undocumented role of P-gp in host-parasite interaction and suggest a physiological role for P-gp in cholesterol trafficking in mammalian cells. PMID:19389707

  4. China will Reduce Aluminium Export in 2005

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>Starting from January 1, 2005, China eliminated the 8 per cent export tax rebate for aluminium, and further more, the exporters will have to pay 5 per cent export tax. This is beyond the expectations of the producers, for most of them thought only the 8 per cent export tax rebate would be eliminated and it was still too early to add the export tax.

  5. 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

  6. Quantitative comparison of the efficacy of various compounds in lowering intracellular cholesterol levels in Niemann-Pick type C fibroblasts.

    Directory of Open Access Journals (Sweden)

    Zachary T Wehrmann

    Full Text Available Niemann-Pick Type C disease (NPC is a lethal, autosomal recessive disorder caused by mutations in the NPC1 and NPC2 cholesterol transport proteins. NPC's hallmark symptoms include an accumulation of unesterified cholesterol and other lipids in the late endosomal and lysosomal cellular compartments, causing progressive neurodegeneration and death. Although the age of onset may vary in those affected, NPC most often manifests in juveniles, and is usually fatal before adolescence. In this study, we investigated the effects of various drugs, many of which modify the epigenetic control of NPC1/NPC2 gene expression, in lowering the otherwise harmful elevated intracellular cholesterol levels in NPC cells. Our studies utilized a previously described image analysis technique, which allowed us to make quantitative comparisons of the efficacy of these drugs in lowering cholesterol levels in a common NPC1 mutant model. Of the drugs analyzed, several that have been previously studied (vorinostat, panobinostat, and β-cyclodextrin significantly lowered the relative amount of unesterified cellular cholesterol, consistent with earlier observations. In addition, a novel potential treatment, rapamycin, likewise alleviated the NPC phenotype. We also studied combinations of effective compounds with β-cyclodextrin; the addition of β-cyclodextrin significantly enhanced the cholesterol-lowering activity of vorinostat and panobinostat, but had mixed effects with rapamycin. Collectively, these results may provide a basis for the eventual development of improved NPC therapies.

  7. 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.

  8. 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.

  9. 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

  10. Cellular: Toward personal communications

    Science.gov (United States)

    Heffernan, Stuart

    1991-09-01

    The cellular industry is one of the fastest growing segment of the telecommunications industry. With an estimated penetration rate of 20 percent in the near future, cellular is becoming an ubiquitous telecommunications service in the U.S. In this paper we will examine the major advancements in the cellular industry: customer equipment, cellular networks, engineering tools, customer support, and nationwide seamless service.

  11. The Effect of Export Tax on Indonesia’s Cocoa Export Competitiveness

    OpenAIRE

    Rifin, Amzul; Nauly, Dahlia

    2013-01-01

    The government of Indonesia implemented an export tax policy on cocoa beans since April 2010 in order to develop cocoa processing industry. The objective of this article is to analyze the effect of export tax on Indonesia’s cocoa export competitiveness. The results indicate that with the implementation of export tax, cocoa export product composition shift from cocoa beans to processed cocoa products. On the other hand, Indonesia’s cocoa export growth is lower than the growth of cocoa world de...

  12. International Marketing Strategies and the relationship with the export performance and export marketing orientation

    OpenAIRE

    Marlon Dalmoro

    2010-01-01

    This work aims to identify the relationship between marketing strategies of exporting Taquari Valley firms with the export performance and export market orientation. To achieve the goal sought proposed is the development of theoretical benchmark, made up items strategies for international marketing, export performance and export market orientation. In epistemological level was conducted a survey, applying for a questionnaire to a sample of 25 exporting companies that have industrial activitie...

  13. The Development Of Export Marketing Strategies Between Manufacturer And Merchant Exporters Within The Indian Apparel Industry

    OpenAIRE

    Davar, S C; Rajagopal, S

    1992-01-01

    With the growing apparel exports from India, the development of export marketing strategies for manufacturer and merchant exporters become significant. This study identifies and draws out the major strategy elements used by manufacturer and merchant exporters. The study indicates that manufacturer exporters utilize product diversification, improved quality and differentiation, competitive pricing, better promotion and having diverse market as elements of their export marketing strategies. The...

  14. Guar gum and similar soluble fibers in the regulation of cholesterol metabolism: Current understandings and future research priorities

    Directory of Open Access Journals (Sweden)

    Todd C Rideout

    2008-10-01

    Full Text Available Todd C Rideout1, Scott V Harding1, Peter JH Jones1, Ming Z Fan21Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba, Winnipeg, Manitoba, Canada; 2Centre for Nutrition Modeling, Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, CanadaAbstract: The hypocholesterolemic effects associated with soluble fiber consumption are clear from animal model and human clinical investigations. Moreover, the modulation of whole-body cholesterol metabolism in response to dietary fiber consumption, including intestinal cholesterol absorption and fecal sterol and bile acid loss, has been the subject of many published reports. However, our understanding of how dietary fibers regulate molecular events at the gene/protein level and alter cellular cholesterol metabolism is limited. The modern emphasis on molecular nutrition and rapid progress in ‘high-dimensional’ biological techniques will permit further explorations of the role of genetic polymorphisms in determining the variable interindividual responses to soluble fibers. Furthermore, with traditional molecular biology tools and the application of ‘omic’ technology, specific insight into how fibers modulate the expression of genes and proteins that regulate intestinal cholesterol absorption and alter hepatic sterol balance will be gained. Detailed knowledge of the molecular mechanisms by which soluble fibers reduce plasma cholesterol concentrations is paramount to developing novel fiber-based “cocktails” that target specific metabolic pathways to gain maximal cholesterol reductions.Keywords: dietary fiber, cholesterol, bile acids, gene, protein

  15. PEG-lipid micelles enable cholesterol efflux in Niemann-Pick Type C1 disease-based lysosomal storage disorder.

    Science.gov (United States)

    Brown, Anna; Patel, Siddharth; Ward, Carl; Lorenz, Anna; Ortiz, Mauren; DuRoss, Allison; Wieghardt, Fabian; Esch, Amanda; Otten, Elsje G; Heiser, Laura M; Korolchuk, Viktor I; Sun, Conroy; Sarkar, Sovan; Sahay, Gaurav

    2016-01-01

    2-Hydroxy-propyl-β-cyclodextrin (HPβCD), a cholesterol scavenger, is currently undergoing Phase 2b/3 clinical trial for treatment of Niemann Pick Type C-1 (NPC1), a fatal neurodegenerative disorder that stems from abnormal cholesterol accumulation in the endo/lysosomes. Unfortunately, the extremely high doses of HPβCD required to prevent progressive neurodegeneration exacerbates ototoxicity, pulmonary toxicity and autophagy-based cellular defects. We present unexpected evidence that a poly (ethylene glycol) (PEG)-lipid conjugate enables cholesterol clearance from endo/lysosomes of Npc1 mutant (Npc1(-/-)) cells. Herein, we show that distearyl-phosphatidylethanolamine-PEG (DSPE-PEG), which forms 12-nm micelles above the critical micelle concentration, accumulates heavily inside cholesterol-rich late endosomes in Npc1(-/-) cells. This potentially results in cholesterol solubilization and leakage from lysosomes. High-throughput screening revealed that DSPE-PEG, in combination with HPβCD, acts synergistically to efflux cholesterol without significantly aggravating autophagy defects. These well-known excipients can be used as admixtures to treat NPC1 disorder. Increasing PEG chain lengths from 350 Da-30 kDa in DSPE-PEG micelles, or increasing DSPE-PEG content in an array of liposomes packaged with HPβCD, improved cholesterol egress, while Pluronic block copolymers capable of micelle formation showed slight effects at high concentrations. We postulate that PEG-lipid based nanocarriers can serve as bioactive drug delivery systems for effective treatment of lysosomal storage disorders. PMID:27572704

  16. Guar gum and similar soluble fibers in the regulation of cholesterol metabolism: Current understandings and future research priorities

    Directory of Open Access Journals (Sweden)

    Todd C Rideout

    2008-08-01

    Full Text Available Todd C Rideout1, Scott V Harding1, Peter JH Jones1, Ming Z Fan21Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba, Winnipeg, Manitoba, Canada; 2Centre for Nutrition Modeling, Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, CanadaAbstract: The hypocholesterolemic effects associated with soluble fiber consumption are clear from animal model and human clinical investigations. Moreover, the modulation of whole-body cholesterol metabolism in response to dietary fiber consumption, including intestinal cholesterol absorption and fecal sterol and bile acid loss, has been the subject of many published reports. However, our understanding of how dietary fibers regulate molecular events at the gene/protein level and alter cellular cholesterol metabolism is limited. The modern emphasis on molecular nutrition and rapid progress in ‘high-dimensional’ biological techniques will permit further explorations of the role of genetic polymorphisms in determining the variable interindividual responses to soluble fibers. Furthermore, with traditional molecular biology tools and the application of ‘omic’ technology, specific insight into how fibers modulate the expression of genes and proteins that regulate intestinal cholesterol absorption and alter hepatic sterol balance will be gained. Detailed knowledge of the molecular mechanisms by which soluble fibers reduce plasma cholesterol concentrations is paramount to developing novel fiber-based “cocktails” that target specific metabolic pathways to gain maximal cholesterol reductions.Keywords: dietary fiber, cholesterol, bile acids, gene, protein

  17. 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 ...

  18. 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 ...

  19. 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

  20. Niacin and cholesterol: role in cardiovascular disease (review).

    Science.gov (United States)

    Ganji, Shobha H; Kamanna, Vaijinath S; Kashyap, Moti L

    2003-06-01

    Niacin has been widely used as a pharmacologic agent to regulate abnormalities in plasma lipid and lipoprotein metabolism and in the treatment of atherosclerotic cardiovascular disease. Although the use of niacin in the treatment of dyslipidemia has been reported as early as 1955, only recent studies have yielded an understanding about the cellular and molecular mechanism of action of niacin on lipid and lipoprotein metabolism. In brief, the beneficial effect of niacin to reduce triglycerides and apolipoprotein-B containing lipoproteins (e.g., VLDL and LDL) are mainly through: a) decreasing fatty acid mobilization from adipose tissue triglyceride stores, and b) inhibiting hepatocyte diacylglycerol acyltransferase and triglyceride synthesis leading to increased intracellular apo B degradation and subsequent decreased secretion of VLDL and LDL particles. The mechanism of action of niacin to raise HDL is by decreasing the fractional catabolic rate of HDL-apo AI without affecting the synthetic rates. Additionally, niacin selectively increases the plasma levels of Lp-AI (HDL subfraction without apo AII), a cardioprotective subfraction of HDL in patients with low HDL. Using human hepatocytes (Hep G2 cells) as an in vitro model system, recent studies indicate that niacin selectively inhibits the uptake/removal of HDL-apo AI (but not HDL-cholesterol ester) by hepatocytes, thereby increasing the capacity of retained HDL-apo AI to augment cholesterol efflux through reverse cholesterol transport pathway. The studies discussed in this review provide evidence to extend the role of niacin as a lipid-lowering drug beyond its role as a vitamin.

  1. Managerial and learning skills in exporting SMEs

    Directory of Open Access Journals (Sweden)

    RUBÉN FERNÁNDEZ ORTIZ

    2005-12-01

    Full Text Available The relevance of the perception of exports in the field of business management can have a key impact on the exporting behavior of SMEs. In particular, it can determine the decision to implement an export policy, as well as the policies applied to consolidate exports. This paper covers two main aspects. First, the extent to which managerial perceptions of exports affect the decision to export, and second, for these SMEs which are already exporters, we study the managerial perceptions that can help to consolidate their commitment to exports. To this aim, some scales based on structural equations to measure the perception of the advantages and disadvantages of exporting are developed and validated. Both analyses are carried out considering whether the SMEs involved are family businesses or not, so that the results obtained can also explain the potential impact of this fact.

  2. China's coal export and inspection

    International Nuclear Information System (INIS)

    With the development of world's business and trade, coal has become a large part of the import and export goods in the international market. The total amount of coal trade has risen a lot. China is rich in coal resources. According to the estimate made by some experts, the reserve which has been explored recently could be exploited hundreds of years. China's output of raw coal has risen a lot during the past forty years. China coal industry has developed rapidly since the 1980s. It is possible for China to become a big coal export country since it has rich resources and increasing output. The paper suggests four steps which must be taken to expand coal exports in China: improve the level of management and administration of coal mines so as to raise the economic benefit; the follow-up production capacity of the present mines must be enhanced rapidly; step up construction of new large-scale mines; and China's coal washing capacity must be improved speedily since the low capacity has seriously influenced the improvement of coal quality. The paper describes the inspection bureaus and companies that have developed to perform inspection of exports in order to guarantee the quality of export coal

  3. Transcriptome profiling unveils the role of cholesterol in IL-17A signaling in psoriasis.

    Science.gov (United States)

    Varshney, Pallavi; Narasimhan, Aarti; Mittal, Shankila; Malik, Garima; Sardana, Kabir; Saini, Neeru

    2016-01-01

    Psoriasis is a chronic inflammatory skin disease characterized by altered proliferation and differentiation of keratinocytes as well as infiltration of immune cells. Increased expression of Th17 cells and cytokines secreted by them provides evidence for its central role in the pathogenesis of psoriasis. IL-17A, signature cytokine of Th17 cells was found to be highly differentially expressed in psoriatic lesional skin. However, cellular and molecular mechanism by which IL-17A exerts its function on keratinocyte is incompletely understood. To understand IL-17A mediated signal transduction pathways, gene expression profiling was done and differentially expressed genes were analysed by IPA software. Here, we demonstrate that during IL-17A signaling total cholesterol levels were elevated, which in turn resulted in the suppression of genes of cholesterol and fatty acid biosynthesis. We found that accumulation of cholesterol was essential for IL-17A signaling as reduced total cholesterol levels by methyl β cyclodextrin (MBCD), significantly decreased IL-17A induced secretion of CCL20, IL-8 and S100A7 from the keratinocytes. To our knowledge this study for the first time unveils that high level of intracellular cholesterol plays a crucial role in IL-17A signaling in keratinocytes and may explain the strong association between psoriasis and dyslipidemia. PMID:26781963

  4. 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...

  5. 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...

  6. 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....

  7. 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...

  8. Export of the HR eliciting protein, Harpin(Es), of the maize pathogen Erwinia stewartii is species-specific but is independent of the growth temperature.

    Science.gov (United States)

    Ahmad, Musharaf; Alam, Syed Sartaj; Alam, Shah; Usman, Amjad; Coplin, David L

    2007-01-01

    The extra-cellular export of the HR-eliciting protein, Harpin(Es) of the maize pathogen Erwinia stewartii was studied to find out if the protein needs any species-specific signal for its export and to determine if the export of the protein to the medium is affected in any way by the growth temperature. Based upon the experimental evidence, it was proved that the protein (i.e., Harpin(Es)) does require its own export system (species-specific) to get out of the bacterial cell and can not be exported by the export system of even the very closely related bacterium, Erwinia amylovora. It was also found that the export of Harpin(Es) is, unlike the case of Harpin(Ea) (HR-eliciting protein of Erwinia amylovora), independent of the growth temperature.

  9. 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.

  10. 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.

  11. 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

  12. Identification of ABCA1 and ABCG1 in milk fat globules and mammary cells - Implications for milk cholesterol secretion

    DEFF Research Database (Denmark)

    Mani, O; Körner, M; Ontsouka, C E;

    2011-01-01

    The ATP-binding cassette (ABC) transporters ABCA1 and ABCG1 play an important role in cellular cholesterol homeostasis, but their function in mammary gland (MG) tissue remains elusive. A bovine MG model that allows repeated MG sampling in identical animals at different functional stages was used...

  13. The effect of dietary phytosphingosine on cholesterol levels and insulin sensitivity in subjects with the metabolic syndrome

    NARCIS (Netherlands)

    Snel, M.; Sleddering, M.A.; Pijl, H.; Nieuwenhuizen, W.F.; Frölich, M.; Havekes, L.M.; Romijn, J.A.; Jazet, I.M.

    2010-01-01

    Background: Sphingolipids, like phytosphingosine (PS) are part of cellular membranes of yeasts, vegetables and fruits. Addition of PS to the diet decreases serum cholesterol and free fatty acid (FFA) levels in rodents and improves insulin sensitivity.Objective:To study the effect of dietary suppleme

  14. 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.

  15. Second Thoughts on Exporter Productivity

    DEFF Research Database (Denmark)

    Sørensen, Allan; Schröder, Philipp J.H.

    Empirical literature has established a positive link between firm productivity and export status, yet notable exceptions exist. The present paper shows that the underlying theory (Melitz, 2003) is in fact able to accommodate the rule as well as the exception. The fulcrum of the argument is the te......Empirical literature has established a positive link between firm productivity and export status, yet notable exceptions exist. The present paper shows that the underlying theory (Melitz, 2003) is in fact able to accommodate the rule as well as the exception. The fulcrum of the argument...

  16. 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

  17. 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

  18. 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.

  19. CHITINASE-B FROM SERRATIA-MARCESCENS-BJL200 IS EXPORTED TO THE PERIPLASM WITHOUT PROCESSING

    NARCIS (Netherlands)

    BRURBERG, MB; EIJSINK, VGH; HAANDRIKMAN, AJ; VENEMA, G; NES, IF

    1995-01-01

    A gene encoding a chitinase from Serratia marcescens BJL200 was cloned and expressed in Escherichia coli and S. marcescens. Nucleotide sequencing revealed an open reading frame encoding a 55.5 kDa protein of 499 amino acids without a typical signal peptide for export. The cellular localization of th

  20. Acyl-CoA:cholesterol acyltransferases (ACATs/SOATs): Enzymes with multiple sterols as substrates and as activators.

    Science.gov (United States)

    Rogers, Maximillian A; Liu, Jay; Song, Bao-Liang; Li, Bo-Liang; Chang, Catherine C Y; Chang, Ta-Yuan

    2015-07-01

    Cholesterol is essential to the growth and viability of cells. The metabolites of cholesterol include: steroids, oxysterols, and bile acids, all of which play important physiological functions. Cholesterol and its metabolites have been implicated in the pathogenesis of multiple human diseases, including: atherosclerosis, cancer, neurodegenerative diseases, and diabetes. Thus, understanding how cells maintain the homeostasis of cholesterol and its metabolites is an important area of study. Acyl-coenzyme A:cholesterol acyltransferases (ACATs, also abbreviated as SOATs) converts cholesterol to cholesteryl esters and play key roles in the regulation of cellular cholesterol homeostasis. ACATs are most unusual enzymes because (i) they metabolize diverse substrates including both sterols and certain steroids; (ii) they contain two different binding sites for steroidal molecules. In mammals, there are two ACAT genes that encode two different enzymes, ACAT1 and ACAT2. Both are allosteric enzymes that can be activated by a variety of sterols. In addition to cholesterol, other sterols that possess the 3-beta OH at C-3, including PREG, oxysterols (such as 24(S)-hydroxycholesterol and 27-hydroxycholesterol, etc.), and various plant sterols, could all be ACAT substrates. All sterols that possess the iso-octyl side chain including cholesterol, oxysterols, various plant sterols could all be activators of ACAT. PREG can only be an ACAT substrate because it lacks the iso-octyl side chain required to be an ACAT activator. The unnatural cholesterol analogs epi-cholesterol (with 3-alpha OH in steroid ring B) and ent-cholesterol (the mirror image of cholesterol) contain the iso-octyl side chain but do not have the 3-beta OH at C-3. Thus, they can only serve as activators and cannot serve as substrates. Thus, within the ACAT holoenzyme, there are site(s) that bind sterol as substrate and site(s) that bind sterol as activator; these sites are distinct from each other. These features form

  1. Cholesterol Metabolism in Brain and Skin Fibroblasts from Sarda Breed Sheep With Scrapie-resistant and Scrapie-susceptible Genotypes

    Directory of Open Access Journals (Sweden)

    Alessandra Pani

    2007-01-01

    Full Text Available Scrapie is a fatal spongiform encephalopathy of sheep, a transmissible form of prion disease caused by neuronal accumulation of the aberrantly conformed prion protein (PrPsc. Currently, no ante-mortem diagnostic tests are available to detect this untreatable disease in the pre-clinical stage, thus making difficult to control its spread. Recent evidence suggests that the production of PrPsc can be modulated by the levels of membrane cholesterol in neuronal cells. Since cholesterol levels in cell membranes are dependent on cholesterol homeostasis in the whole organism, we studied cholesterol metabolism in brain tissues, plasma and skin fibroblasts of Sarda breed sheep with scrapie-resistant (ARR/ARR and scrapie-susceptible (ARQ/ARQ prion protein genotypes, both not infected (ARQ/ARQ- and infected (ARQ/ARQ+ with scrapie. We found that, the levels of cytoplasmic cholesterol esters (CE in brains and skin fibroblasts from sheep with the ARQ/ARQ genotype were consistently higher than those from sheep with the ARR/ARR genotype. Conversely, the levels of free cholesterol (FC were lower in ARQ/ARQ, as compared to ARR/ARR sheep, thus resulting in a sharp reduction of the FC/CE ratio. Moreover, both uninfected and infected ARQ/ARQ sheep showed abnormally low levels of high density lipoprotein-cholesterol (HDL-C in their plasma, as compared to ARR/ARR sheep. These data other than adding new strength to the notion that altered levels of intracellular cholesterol may indicate the presence of a lipid metabolic state that predisposes to infection with, and accumulation of, PrPsc in the brain, discriminate for the first time between two distinct but related cellular pools of cholesterol, namely membrane FC on one hand and cytoplasmic CE on the other.

  2. Home Textile Exports Show Recovery Signs

    Institute of Scientific and Technical Information of China (English)

    Yao Lan; Guoyun

    2010-01-01

    @@ In this article we have analysed the export performance of Chinese main home textile products, including bedding products, carpet, curtain and towel based on official export data during the first eight months of 2010.

  3. 2006 RE Export Enterprises List Announced

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ According to "Requirement for RE Export Enterprises and Application Procedure in 2006", the Ministry of Commerce P.R.C announced "2006 Rare Earth Export Enterprises List "on December 30th of 2005. The enterprises are listed below.

  4. 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.

  5. On American Cultural Exportation Strategy

    Institute of Scientific and Technical Information of China (English)

    李德俊

    2015-01-01

    American government has been attaching great importance to the role that cultural values plays in international relationships and Culture Exportation has gradually become one of the important parts of American diplomatic strategy.This strategy,which is propelled by a variety of impetuses and conducted by different approaches,is mainly aimed to serve the overall national interests of the United States.

  6. On American Cultural Exportation Strategy

    Institute of Scientific and Technical Information of China (English)

    李德俊

    2015-01-01

    American government has been attaching great importance to the role that cultural values plays in international relationships and Culture Exportation has gradually become one of the important parts of American diplomatic strategy. This strategy,which is propelled by a variety of impetuses and conducted by different approaches,is mainly aimed to serve the overall national interests of the United States.

  7. A Strong Backbone For Export

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    China Export & Credit Insurance Corp., founded in 2001, is the country’s only policy-oriented credit insurance company. In line with the state’s diplomatic, foreign trade and industrial policies, it supports the country’s commodity, technology and servic

  8. JOINT VENTURES AMONG EXPORTING FIRMS

    OpenAIRE

    CHAUDHURI, Prabal Ray

    2000-01-01

    In this paper we examine the incentive for joint venture formation among exporting firms. We show that an increase in domestic demand increases the incentive for joint venture formation. An increase in world price, however, can either increase or decrease the incentive for joint venture formation.

  9. Enhancement of interaction of BSEP and HAX-1 on the canalicular membrane of hepatocytes in a mouse model of cholesterol cholelithiasis

    OpenAIRE

    Kong, Jing; Liu, Bin-Bin; Wu, Shuo-Dong; Wang, Yu; Jiang, Qing-Quan; Guo, En-Ling

    2014-01-01

    We induced gallstones in C57L mice fed with a high cholesterol diet and examined the expression of bile salt export pump (BSEP) on the canalicular membrane of hepatocytes and its relation with PKCα and HAX-1.Twenty-four gallstone-prone C57L mice were randomly assigned to receive a high cholesterol diet or a regular diet. Gallstone formation was recorded. BSEP, PKCα and phospho-PKCα expression was examined by immunoblotting assays. Co-expression of BSEP and HAX-1 was studied by immunofluoresce...

  10. Branch being forced to work for export

    International Nuclear Information System (INIS)

    Evaluation of efficiency of export of the Tyumen' oil and oil products in February-April 1996 is given. Effect of export taxes reduction and changes of the situation at the internal and external oil market on the export of oil and oil products is considered. Possible prospects on the export development as well as consequences of the newly-adopted tax code for the oil industry are discussed

  11. Export channel pricing management for integrated solutions

    OpenAIRE

    Roine, Henna; Sainio, Liisa-Maija; Saarenketo, Sami

    2012-01-01

    This article studies systems integrators' export channel pricing management for integrated solutions. We find support from our empirical case study for the notion that a systems integrator's export channel pricing strategy is multidimensional and dependent on international pricing environment and partner characteristics and that export partnerships have unique implications on a systems integrator's pricing process. The results show that giving up pricing control in export channel context may ...

  12. EXPORT MARKETING IN INDIA: PROSPECTS AND CHALLENGES

    OpenAIRE

    S. G. Sagar

    2015-01-01

    In export marketing, goods are sent abroad as per the formalities and procedures framed by the home countries as well as by the importing countries. Export marketing is certainly more complicated as compared to domestic marketing particularly due to severe international competition, lengthy procedures and formalities and the quality and cost factors involved. Along with this, export marketing offers ample opportunities for earning high profits. In addition, export marketing has wider economic...

  13. 75 FR 11842 - Export Trade Certificate of Review

    Science.gov (United States)

    2010-03-12

    ... on trade opportunities; marketing; negotiations; joint ventures; shipping; export management; export... marketing activities; b. Collect information on trade opportunities in the Export Markets and distribute... International Trade Administration Export Trade Certificate of Review ACTION: Notice of Application (...

  14. [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.

  15. 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.

  16. 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.

  17. 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...

  18. 27 CFR 7.60 - Exports.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Exports. 7.60 Section 7.60... TREASURY LIQUORS LABELING AND ADVERTISING OF MALT BEVERAGES General Provisions § 7.60 Exports. This part shall not apply to malt beverages exported in bond....

  19. 27 CFR 28.223 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.223... Export marks. In addition to the marks and brands required to be placed on kegs, barrels, cases, crates... “Export” on each container or case before removal for export, for use on vessels or aircraft, or...

  20. 27 CFR 16.31 - Exports.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Exports. 16.31 Section 16... TREASURY LIQUORS ALCOHOLIC BEVERAGE HEALTH WARNING STATEMENT General Provisions § 16.31 Exports. The..., bottled, or labeled for export from the United States, or for delivery to a vessel or aircraft,...

  1. 22 CFR 120.17 - Export.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Export. 120.17 Section 120.17 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.17 Export. (a) Export means: (1) Sending or taking a defense article out of the United States in any manner, except...

  2. 27 CFR 28.154 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.154..., for Exportation or Transfer to a Foreign-Trade Zone § 28.154 Export marks. In addition to the marks... provisions of part 19 of this chapter, the proprietor shall mark the word “Export” on the Government side...

  3. 27 CFR 4.80 - Exports.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Exports. 4.80 Section 4.80... TREASURY LIQUORS LABELING AND ADVERTISING OF WINE General Provisions § 4.80 Exports. The regulations in this part shall not apply to wine exported in bond....

  4. 27 CFR 28.193 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.193... Drawback Filing of Notice and Removal § 28.193 Export marks. In addition to the marks and brands required... chapter, the exporter shall mark the word “Export” on the Government side of each case or Government...

  5. 19 CFR 351.520 - Export insurance.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Export insurance. 351.520 Section 351.520 Customs... Identification and Measurement of Countervailable Subsidies § 351.520 Export insurance. (a) Benefit—(1) In general. In the case of export insurance, a benefit exists if the premium rates charged are inadequate...

  6. Export growth slowdown from January to April

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    January to April this year, the economic operation of China’s textile industry overall in slowdown trend, the growth rate of output of major products fell significantly, exports and profits were greatly affected, the textile industry is facing great operating pressure. The export side, Japan, EU, U.S. textile and garment export growth has slowed down, the market share

  7. 7 CFR 966.18 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 966.18 Section 966.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... Handling Definitions § 966.18 Export. Export means shipment of tomatoes beyond the boundaries of the...

  8. 7 CFR 927.12 - Export market.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export market. 927.12 Section 927.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Order Regulating Handling Definitions § 927.12 Export market. Export market means any destination...

  9. 7 CFR 923.15 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 923.15 Section 923.15 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... IN WASHINGTON Order Regulating Handling Definitions § 923.15 Export. Export means to ship...

  10. 7 CFR 948.17 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 948.17 Section 948.17 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... Regulating Handling Definitions § 948.17 Export. Export means the shipment of potatoes to any...

  11. 7 CFR 924.15 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 924.15 Section 924.15 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... WASHINGTON AND IN UMATILLA COUNTY, OREGON Order Regulating Handling Definitions § 924.15 Export. Export...

  12. 7 CFR 947.17 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 947.17 Section 947.17 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... Definitions § 947.17 Export. Export means shipment of potatoes beyond the boundaries of continental...

  13. 7 CFR 946.15 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 946.15 Section 946.15 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... Regulating Handling Definitions § 946.15 Export. Export means shipment of potatoes beyond the boundaries...

  14. 7 CFR 915.12 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 915.12 Section 915.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... Regulating Handling Definitions § 915.12 Export. Export means to ship avocados to any destination which...

  15. 7 CFR 959.18 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 959.18 Section 959.18 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... Handling Definitions § 959.18 Export. Export means to ship onions to any destination which is not...

  16. 7 CFR 922.15 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 922.15 Section 922.15 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... WASHINGTON Order Regulating Handling Definitions § 922.15 Export. Export means to ship apricots beyond...

  17. Export market potential for selected horticultural crops

    International Nuclear Information System (INIS)

    This paper examines the feasibility of utilising an irradiation plant to disinfest fresh fruit and vegetables destined for export markets. It examines the export market potential of selected crops with the prime view of estimating likely trends in export markets in the future. These trends will have a significant bearing on throughput levels, and hence on the economic viability of an ionising energy plant

  18. In Situ Probing of Cholesterol in Astrocytes at the Single Cell Level using Laser Desorption Ionization Mass Spectrometric Imaging with Colloidal Silver

    Energy Technology Data Exchange (ETDEWEB)

    Perdian, D.C.; Cha, Sangwon; Oh, Jisun; Sakaguchi, Donald S.; Yeung, Edward S.; and Lee, Young Jin

    2010-03-18

    Mass spectrometric imaging has been utilized to localize individual astrocytes and to obtain cholesterol populations at the single-cell level in laser desorption ionization (LDI) with colloidal silver. The silver ion adduct of membrane-bound cholesterol was monitored to detect individual cells. Good correlation between mass spectrometric and optical images at different cell densities indicates the ability to perform single-cell studies of cholesterol abundance. The feasibility of quantification is confirmed by the agreement between the LDI-MS ion signals and the results from a traditional enzymatic fluorometric assay. We propose that this approach could be an effective tool to study chemical populations at the cellular level.

  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. Resource-Based and Institutional Perspectives on Export Channel Selection and Export Performance

    OpenAIRE

    He, X; Brouthers, K. D.; Filatotchev, I.

    2012-01-01

    Exporting is a critically important strategy for firms to grow, yet research in this area has tended to ignore how firms can leverage resource-based capabilities to improve export performance. Building on the resource-based view and institutional theory, the authors develop a novel perspective to explain how a firm can improve export performance by aligning its export channel with its level of market orientation capabilities, contingent on the institutional distance between home and export ma...

  4. 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.

  5. 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.

  6. 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)

  7. 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....

  8. 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

  9. Human Capital and Wages in Exporting Firms

    DEFF Research Database (Denmark)

    Munch, Jakob Roland; Skaksen, Jan Rose

    . Using a very rich matched worker-firm longitudinal dataset we find that firms with high export intensities pay higher wages. However, an interaction term between export intensity and skill intensity has a positive impact on wages and it absorbs the direct effect of the export intensity. That is, we find......This paper studies the link between a firms education level, export performance and wages of its workers. We argue that firms may escape intense competition in international markets by using high skilled workers to differentiate their products. This story is consistent with our empirical results...... an export wage premium, but it accrues to workers in firms with high skill intensities...

  10. Cytomegalovirus Restructures Lipid Rafts via a US28/CDC42-Mediated Pathway, Enhancing Cholesterol Efflux from Host Cells

    Directory of Open Access Journals (Sweden)

    Hann Low

    2016-06-01

    Full Text Available Cytomegalovirus (HCMV contains cholesterol, but how HCMV interacts with host cholesterol metabolism is unknown. We found that, in human fibroblasts, HCMV infection increased the efflux of cellular cholesterol, despite reducing the abundance of ABCA1. Mechanistically, viral protein US28 was acting through CDC42, rearranging actin microfilaments, causing association of actin with lipid rafts, and leading to a dramatic change in the abundance and/or structure of lipid rafts. These changes displaced ABCA1 from the cell surface but created new binding sites for apolipoprotein A-I, resulting in enhanced cholesterol efflux. The changes also reduced the inflammatory response in macrophages. HCMV infection modified the host lipidome profile and expression of several genes and microRNAs involved in cholesterol metabolism. In mice, murine CMV infection elevated plasma triglycerides but did not affect the level and functionality of high-density lipoprotein. Thus, HCMV, through its protein US28, reorganizes lipid rafts and disturbs cell cholesterol metabolism.

  11. The anti‑dengue virus properties of statins may be associated with alterations in the cellular antiviral profile expression.

    Science.gov (United States)

    Bryan-Marrugo, Owen Lloyd; Arellanos-Soto, Daniel; Rojas-Martinez, Augusto; Barrera-Saldaña, Hugo; Ramos-Jimenez, Javier; Vidaltamayo, Roman; Rivas-Estilla, Ana María

    2016-09-01

    Dengue virus (DENV) susceptibility to cholesterol depleting treatments has been previously reported. There are numerous questions regarding how DENV seizes cellular machinery and cholesterol to improve viral production and the effect of cholesterol sequestering agents on the cellular antiviral response. The aim of the present study was to evaluate the mechanisms involved in the negative regulation of DENV replication induced by agents that diminish intracellular cholesterol levels. Cholesterol synthesis was pharmacologically (fluvastatin, atorvastatin, lovastatin, pravastatin and simvastatin treatment) and genetically (HMGCR‑RNAi) inhibited, in uninfected and DENV2‑infected hepatoma Huh‑7 cells. The cholesterol levels, DENV titer and cellular antiviral expression profile were evaluated. A reduction in the DENV titer, measured as plaque forming units, was observed in DENV‑infected cells following 48 h treatment with 10 µM fluvastatin, 10 µM atorvastatin, 20 µM lovastatin and 20 µM simvastatin, which achieved 70, 70, 65 and 55% DENV2 inhibition, respectively, compared with the untreated cells. In addition, the cytopathic effect was reduced in the statin‑treated DENV‑infected cells. Statins simultaneously reduced cholesterol levels at 48 h, with the exception of DENV2 infected cells. Genetic inhibition of cholesterol synthesis was performed using RNA interference for 3‑hydroxy‑3‑methylglutaryl‑CoA reductase (HMGCR‑siRNA), which indicated a slight reduction in DENV2 titer at 48 h post‑infection, however, with no significant reduction in cholesterol levels. In addition, DENV2 infection was observed to augment the intracellular cholesterol levels in all experimental conditions. Comparison between the cellular antiviral response triggered by DENV2 infection, statin treatment and HMGCR‑siRNA in infected, uninfected, treated and untreated Huh7 cells, showed different expression profiles for the antiviral genes evaluated. All

  12. 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.

  13. 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

  14. 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...

  15. 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.

  16. Export Rebates on Grain Finished

    Institute of Scientific and Technical Information of China (English)

    Liu; Xinwen

    2008-01-01

      According to the State Statistics Bureau, China's consumer price index (CPI) jumped by 6.9 percent year-on-year last November, approaching the high levels seen at the end of 1996, one of the largest areas of increase was the price of grain,which rose by 6.6 percent. There is no doubt the growth in CPI can be mainly attributed to soaring food prices and the diffusion effect of oil price adjustments. Large orders for grain exports have put Chinese grain suppliers under tremendous pressure. In order to solve this problem, the Finance Ministry and State Administration of Taxation together announced that 84 categories of export tax rebates on major types of grain will be eliminated.……

  17. Export Rebates on Grain Finished

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ According to the State Statistics Bureau, China's consumer price index (CPI) jumped by 6.9 percent year-on-year last November, approaching the high levels seen at the end of 1996, one of the largest areas of increase was the price of grain,which rose by 6.6 percent. There is no doubt the growth in CPI can be mainly attributed to soaring food prices and the diffusion effect of oil price adjustments. Large orders for grain exports have put Chinese grain suppliers under tremendous pressure. In order to solve this problem, the Finance Ministry and State Administration of Taxation together announced that 84 categories of export tax rebates on major types of grain will be eliminated.

  18. Quality, Export and Economic Growth

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Pedersen, Kurt

    1998-01-01

    Growth rates in Far Eastern economies have, until recently, been one of the most debated international features. At the same time, quality focus has spread from the same region, notably Japan. It seems only natural to include the concept of quality in an attempt to understand economic growth...... in an international context. The paper, therefore, addresses the complicated interactions between economic growth, export performance and quality. The contribution of the paper, compared to other growth accounting research, is the inclusion of quality data, quality being a significant mirror of technological...... development. The countries covered by the research represent a wide variation in terms of economic development, from poor LDC's to the most developed industrial nations. The empirical results reveal a probable strong relationship between quality/price and export growth as well as economic growth. This new...

  19. Creative destruction and export patterns

    DEFF Research Database (Denmark)

    Hansen, Jørgen Drud; Kvedaras, Virmantas; Nielsen, Jørgen Ulff-Møller

    2014-01-01

    behavior. The model highlights a process of creative destruction, which allows firms to produce in a finite span of periods determined by the intensity of product and process innovations. The model predicts a wide range of export behavior of the individual firm during its life cycle depending......This paper presents an international trade model based on a market structure with monopolistic competition and age dependent quality and productivity in producing each product variety. Due to innovations new product varieties of a still higher quality enter the market every period rendering old...... varieties obsolete. For a given technology (variety) production costs decrease after an infant period due to learning. While all firms are assumed to be symmetric in a life-cycle perspective, at a given point in time firms of different ages differ in productivity, firm size, product quality, and export...

  20. Export Intermediation and the Internet

    DEFF Research Database (Denmark)

    Andersen, Poul Houman

    2005-01-01

    may not necessarily outperform intermediaries, as physical distribution channels still hold several positional advantages compared to virtually organised ones and the Internet provides organisational and managerial challenges as well. Although reduced market friction may beget some activities......It is claimed that the remarkable growth in numbers of connected firms to the Internet marks a radical shift in current organisation of international business channels. For export intermediaries these new possibilities pose a threat to their current market position. However, virtual market presence...

  1. Globalization and Distribution of Exports

    OpenAIRE

    Johansson, Börje; Nilsson, Desirée

    2007-01-01

    During the 1980s many economists started to use the term globalisation as a catchword for  an increased interaction between countries in world trade. The literature does not provide a clear definition of globalisation. We set up a number of criteria and formulate hypotheses about globalisation that we explore for Swedish export flows during the years 1965-2000. Globalisation, in this study, is referred to as increases in country diversity, extended transport radii, less effect of distance on ...

  2. Chinese Rebalancing and Australian Exports

    OpenAIRE

    Gerard Kelly

    2014-01-01

    The Chinese authorities plan to gradually rebalance the composition of Chinese economic growth from investment towards household consumption. This article uses the World Input-Output Database (WIOD) to give a general sense of how this rebalancing might affect Australian exports and economic activity. Dollar for dollar, Chinese investment appears to absorb more than twice as much Australian value-added output as Chinese household consumption. This largely reflects the significant role of resou...

  3. SR-BI: Linking Cholesterol and Lipoprotein Metabolism with Breast and Prostate Cancer

    Science.gov (United States)

    Gutierrez-Pajares, Jorge L.; Ben Hassen, Céline; Chevalier, Stéphan; Frank, Philippe G.

    2016-01-01

    Studies have demonstrated the significant role of cholesterol and lipoprotein metabolism in the progression of cancer. The SCARB1 gene encodes the scavenger receptor class B type I (SR-BI), which is an 82-kDa glycoprotein with two transmembrane domains separated by a large extracellular loop. SR-BI plays an important role in the regulation of cholesterol exchange between cells and high-density lipoproteins. Accordingly, hepatic SR-BI has been shown to play an essential role in the regulation of the reverse cholesterol transport pathway, which promotes the removal and excretion of excess body cholesterol. In the context of atherosclerosis, SR-BI has been implicated in the regulation of intracellular signaling, lipid accumulation, foam cell formation, and cellular apoptosis. Furthermore, since lipid metabolism is a relevant target for cancer treatment, recent studies have focused on examining the role of SR-BI in this pathology. While signaling pathways have initially been explored in non-tumoral cells, studies with cancer cells have now demonstrated SR-BI's function in tumor progression. In this review, we will discuss the role of SR-BI during tumor development and malignant progression. In addition, we will provide insights into the transcriptional and post-transcriptional regulation of the SCARB1 gene. Overall, studying the role of SR-BI in tumor development and progression should allow us to gain useful information for the development of new therapeutic strategies.

  4. NAS Panel faults export controls

    Science.gov (United States)

    Katzoff, Judith A.

    A study prepared by a top-level panel says that current export controls on militarily sensitive U.S. technology may be “overcorrecting” previous weaknesses in that system, resulting in “a complex and confusing control system” that makes it more difficult for U.S. businesses to compete in international markets. Moreover, this control system has “an increasingly corrosive effect” on U.S. relations with allies. The panel recommended that the United States concentrate more effort on bringing about uniformity in the export control policies of countries belonging to the Coordinating Committee on Multilateral Export Controls (CoCom), i.e., most of the member nations in NATO (the North Atlantic Treaty Organization) and Japan.The 21-member panel was appointed by the Committee on Science, Engineering, and Public Policy (COSEPUP), a joint unit of the National Academy of Sciences (NAS), the National Academy of Engineering (NAE), and the Institute of Medicine (IOM). The panel, composed of administrators, researchers, and former government officials, was chaired by AGU member Lew Allen, Jr., director of the Jet Propulsion Laboratory (Pasadena, Calif.) and former chief of staff of the U.S. Air Force. Their report was supported by NAS funds, by a number of private organizations (including AGU), by the U.S. Departments of Commerce, Defense, Energy, and State, by the National Science Foundation, and by the National Aeronautics and Space Administration.

  5. 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

  6. 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

  7. [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

  8. 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.

  9. Nuclear export controls - Closing the gaps

    International Nuclear Information System (INIS)

    Concerns over a nuclear 'black market' have focused international attention on the effectiveness of nuclear export controls. IAEA Director General Mohamed ElBaradei has stated that the emergence of a multinational illicit network demonstrated the inadequacy of the present export control system, that international cooperation on export controls lay on informal arrangements that were not only not binding but also limited in membership, and that export control information was not systematically shared with the IAEA. This criticism, often heard on the political level, does not really do justice to the work of export control groups. The emergence of a multinational illicit network does not necessarily prove failures in export control systems. Criminal activities, by definition, try to circumvent existing rules and regulations, or they exploit the absence of such rules on State level. To fight such individual cases is not so much a task of regular export control systems, whose function lies primarily in establishing standards and procedures for export controls on State level, but rather the task for intelligence services and their international cooperation. The basis of the export control regime is the Nuclear Non-Proliferation Treaty (NPT). Export controls can - and do - play an important role in fostering this universality goal by demanding the implementation of internationally agreed security standards in recipient countries before export licenses are granted. Drawn from the deliberations in the NPT conferences, the current standards to be demanded as conditions of supply are the following: Safeguards, Physical Protection, National export control provisions. According to the NPT system, export controls require IAEA verification in the recipient country. In addition, export controls enable States to provide information to the IAEA on exports and imports as required by the Additional Protocol. The 2005 NPT Review Conference will be an opportunity to review developments

  10. 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.

  11. Chronic intermittent psychological stress promotes macrophage reverse cholesterol transport by impairing bile acid absorption in mice.

    Science.gov (United States)

    Silvennoinen, Reija; Quesada, Helena; Kareinen, Ilona; Julve, Josep; Kaipiainen, Leena; Gylling, Helena; Blanco-Vaca, Francisco; Escola-Gil, Joan Carles; Kovanen, Petri T; Lee-Rueckert, Miriam

    2015-05-11

    Psychological stress is a risk factor for atherosclerosis, yet the pathophysiological mechanisms involved remain elusive. The transfer of cholesterol from macrophage foam cells to liver and feces (the macrophage-specific reverse cholesterol transport, m-RCT) is an important antiatherogenic pathway. Because exposure of mice to physical restraint, a model of psychological stress, increases serum levels of corticosterone, and as bile acid homeostasis is disrupted in glucocorticoid-treated animals, we investigated if chronic intermittent restraint stress would modify m-RCT by altering the enterohepatic circulation of bile acids. C57Bl/6J mice exposed to intermittent stress for 5 days exhibited increased transit through the large intestine and enhanced fecal bile acid excretion. Of the transcription factors and transporters that regulate bile acid homeostasis, the mRNA expression levels of the hepatic farnesoid X receptor (FXR), the bile salt export pump (BSEP), and the intestinal fibroblast growth factor 15 (FGF15) were reduced, whereas those of the ileal apical sodium-dependent bile acid transporter (ASBT), responsible for active bile acid absorption, remained unchanged. Neither did the hepatic expression of cholesterol 7α-hydroxylase (CYP7A1), the key enzyme regulating bile acid synthesis, change in the stressed mice. Evaluation of the functionality of the m-RCT pathway revealed increased fecal excretion of bile acids that had been synthesized from macrophage-derived cholesterol. Overall, our study reveals that chronic intermittent stress in mice accelerates m-RCT specifically by increasing fecal excretion of bile acids. This novel mechanism of m-RCT induction could have antiatherogenic potential under conditions of chronic stress. PMID:25969465

  12. Export Marketing of Croatian Baby Beef

    Directory of Open Access Journals (Sweden)

    Ante Kolega

    2003-09-01

    Full Text Available Croatia has traditionally been the exporter of livestock and beef. In 1988 Croatia exported a record of 35,7 thousand tons of livestock, worth almost 60 million US $. During the period between 1981 and 1991, the export of beef and processed meat was somewhat smaller, about 12,8 thousand tons, 40 million US $ worth. The most important export destinations were Italy, with almost 90% of all volume and monetary value of export, and Greece. In March 1993 EU has banned the import of livestock and beef from Croatia, due to a scandal with infected cattle. In spite of the subsequent abolition of this ban, Croatian export never really recovered, so today the export of beef amounts to less than a thousand tons. Even though the conditions on the export markets and in the domestic cattle breeding industry have changed, we think that it is possible to achieve the export expansion of Croatian baby beef in the foreign market. This article describes the results of the research conducted on the Italian and Greek market. According to expert opinions and the results of our survey it is evident that, with a certain quality of the product, it would be possible to renew the export of Croatian baby beef to the target markets.

  13. 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.

  14. 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...

  15. 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....

  16. 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 ...

  17. 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 ...

  18. 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.

  19. An overview of the certified organic export sector in Uganda

    OpenAIRE

    Gibbon, Peter

    2006-01-01

    This paper reports the results of a survey of almost all certified and in-conversion organic export operations in Uganda in late 2005. It covers products exported, company size and ownership, standards exported to, certification costs, total export values, value-added in Uganda, marketing channels, crop procurement systems, management of organic operations and the main challenges experienced by exporters. Findings include that numbers of certified exporters are growing rapidly. Export values ...

  20. 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.

  1. Modelling cellular behaviour

    Science.gov (United States)

    Endy, Drew; Brent, Roger

    2001-01-01

    Representations of cellular processes that can be used to compute their future behaviour would be of general scientific and practical value. But past attempts to construct such representations have been disappointing. This is now changing. Increases in biological understanding combined with advances in computational methods and in computer power make it possible to foresee construction of useful and predictive simulations of cellular processes.

  2. 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}.

  3. 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

  4. 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

  5. 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…

  6. 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...

  7. 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)

  8. 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

  9. 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...

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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

  15. Reversible quantum cellular automata

    CERN Document Server

    Schumacher, B

    2004-01-01

    We define quantum cellular automata as infinite quantum lattice systems with discrete time dynamics, such that the time step commutes with lattice translations and has strictly finite propagation speed. In contrast to earlier definitions this allows us to give an explicit characterization of all local rules generating such automata. The same local rules also generate the global time step for automata with periodic boundary conditions. Our main structure theorem asserts that any quantum cellular automaton is structurally reversible, i.e., that it can be obtained by applying two blockwise unitary operations in a generalized Margolus partitioning scheme. This implies that, in contrast to the classical case, the inverse of a nearest neighbor quantum cellular automaton is again a nearest neighbor automaton. We present several construction methods for quantum cellular automata, based on unitaries commuting with their translates, on the quantization of (arbitrary) reversible classical cellular automata, on quantum c...

  16. 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...

  17. An investigation into internationalization motives, export barriers and the export marketing strategies that effect exporting performance of Thai textile SME Company

    OpenAIRE

    Eowpittayakul, Pongsakorn

    2007-01-01

    This dissertation looks at the experiences of exporting textile SME Company in Thailand. The aims of this project are to get an insight view into how Thai firm's export motivation. Moreover, the study is to find the export barriers that affect the firm export performance in different ways. This study further investigated into firm export marketing strategies that affect the firm export performance in a particular area. The project involved gauging reactions from Jong Pattana Co., LTD., wh...

  18. 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...

  19. Human Capital and Wages in Exporting Firms

    DEFF Research Database (Denmark)

    Munch, Jakob Roland; Skaksen, Jan Rose

    2006-01-01

    . Osing a very rich matched worker-firm longitudinal dataset we find that firms with high export intensities pay higher wages. However, an interaction term between export intensity and skill intensity has a positive impact on wages and it absorbs the direct effect of the export intensity. That is, we find......This paper studies the link between a firms education level, export performance and wages of its workers. We argue that firms may escape intence competition in international markets by using high skilled workers to differentiate their products. This story is consistent with our empirical results...... an export wage premium, but it accrues to workers in firms with high skill intensities.Keywords: Exports, Wages, Human Capital, Rent Sharing, Matched Worker-Firm DataJEL Classification: J30, F10, I20...

  20. Price and Income Elasticities of Russian Exports

    Directory of Open Access Journals (Sweden)

    Bernardina Algieri

    2004-12-01

    Full Text Available The paper gauges export demand elasticities for Russia using an Error Correction technique within a cointegration framework. An extended version of the Imperfect Substitutes Model has been implemented to estimate the sensitivity of Russian exports without oil components to price and to Russian and world income. Our results suggest a robust and negative long run cointegration relationship between the real effective exchange rate, defined as the weighted average of the rouble’s exchange rates versus a basket of the three currencies with the largest share in the trade turnover adjusted to incorporate inflation rate differences (the ratio of the domestic price indices to the foreign price indices, and Russian exports. An increase in exports by 24% is caused by a real depreciation by 10%. Furthermore, a 10% growth in world income leads to a 33% rise in exports. Finally, exports drop by 14% whenever a 10% increase in domestic income occurs

  1. Price and Income Elasticities of Iranian Exports

    Science.gov (United States)

    Atrkar Roshan, Sedigheh

    This study investigates the export demand elasticities at the aggregate and disaggregated levels over the period 1977 to 2001 for Iran. By utilizing an export demand model and using time series techniques that account for the nonstationarity in the data, the price and income elasticities of demand are estimated by commodity class. As the elasticities of demand for various categories of exports are different, while they are crucial for policy determination. Based upon the estimated results, price and income elasticities are almost similar to those obtained in earlier studies in the case of developing countries. The main findings of this paper demonstrate that, price elasticities are smaller than -1 for all exports categories, whereas the income elasticities are found to be greater than one. The results also suggested, the income elasticities of industrial goods are higher compared to other export categories, while the lower elasticities are found in primary exports. The price and income elasticity estimates have also good statistical properties.

  2. Promoting exports in the energy technology area

    International Nuclear Information System (INIS)

    This report for the Swiss Federal Office of Energy (SFOE) examines the position of Switzerland as a leader in the investment goods markets for energy-efficiency products and for technologies for using renewable forms of energy. The report quotes figures for exports in these areas and discusses the difficulty of extracting useful data on these products from normal statistical data. Analyses made by a group of experts from the export-oriented technology field, energy service providers and representatives of export promotion institutions are presented and figures are quoted for various product categories. Factors promoting the competitiveness of Swiss products are discussed as well as those impeding it. An analysis of export potential is presented and measures to promote export are discussed. The report also discusses the aids and promotion activities that are considered necessary by companies in the field and the macro-economic perspectives of increased export promotion

  3. 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 ...

  4. 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...

  5. Should Australia Export its Native Birds?

    OpenAIRE

    Kingwell, Ross S.

    1994-01-01

    Commercial export from Australia of native birds, wild or captive bred, is prohibited. This paper firstly describes the current legislation and regulations that restrict the export of native birds and discusses why governments have adopted such a regulatory approach to bird species preservation. Secondly, the paper reviews the debate concerning the export ban, pointing out strengths and weaknesses in arguments and indicating the important role of CITES. Lastly, the paper outlines a new case f...

  6. India's Export of Livestock and Allied Products

    OpenAIRE

    J K Sachdeva

    2005-01-01

    One of the main objectives of the governments’ export policy is to maximise agricultural exports in order to earn foreign exchange. It also seeks to provide remunerative prices to the farmers while ensuring adequate availability of essential commodities to the domestic consumers at reasonable prices. This paper analyses the India’s exports of livestock and allied products to principal groups of countries in the light of world trade. The direction of trade has been analysed to explore the area...

  7. Natural gas exports and macroeconomic performance

    International Nuclear Information System (INIS)

    Alberta, in volumetric terms, is Canada's leading exporter of natural gas, crude oil, bitumen, and coal. Alberta natural gas shipments to other Canadian provinces and exports to the United States have developed into an increasingly important component of Alberta economy. This article attempts to measure the impact of gas production and exports on different sectors of the Alberta economy as the energy producing province of Canada

  8. Tax Exportability in Tourism Market

    Directory of Open Access Journals (Sweden)

    Mohammad Mohebi

    2011-01-01

    Full Text Available Problem statement: Tax incidence is a basic topic in public economics as the tourism industry is an increasingly major contributor to government revenue. Generally, government taxation objectives are for the purpose of financing programs that improve people’s lives and economic prosperity, accelerate economic growth and allow for access to sustainable development. In the first view, tax policy decisions by government are based on their effects on the distribution of economic welfare. Therefore, to provide incentives for governments to select a suitable tax policy, exportability of tax is important. Hotel room tax is one of the main parts of tourism tax. Despite the importance of tax for government, it seems that the exportability of hotel room tax is still not well known. Therefore, understanding the counteraction of foreign visitors with respect to its main factors is important for the Malaysian government and tourism management. To achieve these aims, this study examines tax incidence effects on the tourism market. Approach: We use hotel room as representative of tourism market. Quarterly data from 1995-2009 are used and a dynamic model of simultaneous equation is employed. Results: Our results indicate that in the short run supply is elastic and demand is inelastic.But in the long run both demand and supply are elastic to price. Conclusion: Based the results if the government imposes one ringgit (Malaysian currency tax on hotel room price, the tourist contribution is more than 89 and 74% in the short run and long run respectively. Hence, we conclude that the Malaysian tourism market is exportable. Our results also indicate that tax on hotel has no negative social effects in the short run.

  9. International Marketing Strategies and the relationship with the export performance and export marketing orientation

    Directory of Open Access Journals (Sweden)

    Marlon Dalmoro

    2010-04-01

    Full Text Available This work aims to identify the relationship between marketing strategies of exporting Taquari Valley firms with the export performance and export market orientation. To achieve the goal sought proposed is the development of theoretical benchmark, made up items strategies for international marketing, export performance and export market orientation. In epistemological level was conducted a survey, applying for a questionnaire to a sample of 25 exporting companies that have industrial activities, chosen in a not probabilistic manner. Finally, it was observed that the key decisions on how to act in various markets in terms of strategies for international marketing - satisfaction with the internal market, international consistency, adaptation and localization level of the strategies - have relationship with the export market orientation and the export performance of studied companies.

  10. A perspective on energy exports

    International Nuclear Information System (INIS)

    Based on New Brunswick Power's energy export experience over the past two decades, it appears that Canada could have a very special and unique opportunity to input into the US energy market over the coming decades. The CANDU reactor can offer one of these opportunities. Such business opportunities can be of very real benefit to both countries and to the particular regions involved. Like any other form of business, this one must be carefully planned and must be conducted in an environment conducive to the achievement of the objectives of the business

  11. 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 ...

  12. Human capital and wages in exporting firms

    DEFF Research Database (Denmark)

    Munch, Jakob Roland; Skaksen, Jan Rose

    2008-01-01

    a very rich matched worker-firm longitudinal dataset, we find that there is a weak negative direct effect of exporting on wages, but an interaction term between export intensity and skill intensity has a positive impact on wages. That is, we find an export wage premium, but only in firms where the skill......This paper studies the link between the education level of workers, export performance and wages. We argue that firms may escape intense competition in international markets by using high skilled workers to differentiate their products. This story is consistent with our empirical results. Using...

  13. ROMANIAN EXPORT COMPETITIVENESS ON THE EUROPEAN MARKET

    Directory of Open Access Journals (Sweden)

    Paul Clipa

    2011-12-01

    Full Text Available Exports of a nation can form a large part of its commercial card on the international market. Global consumer, according to the quality of exports, may associate a certain image about the country of origin. This article aims at explaining the relationship between exports and competitiveness of a nation, the analysis focuses on the nature and intensity of intra-Community exports of Romania. To this end we considered a number of performance indicators that are able to reveal the positioning of trade from Romania to the EU.

  14. FDI as an Export-Platform

    DEFF Research Database (Denmark)

    Hajderllari, Luljeta; Karantininis, Konstantinos; Lawson, Lartey Godwin

    towards countries with large exports of agri-food, thereby supporting the hypothesis that FDI is used as an export-platform. FDI is coupled with high exports from Denmark, probably of raw or semi-processed food products for further processing and exports. We also find that FDI is higher in countries......We investigate factors affecting Foreign Direct Investment (FDI) outflow from Danish agrifood firms to the rest of the world. We develop a conceptual model and subsequently use a gravity model based on data from 127 countries receiving Danish FDI in agri-food in 2004-2008. We find higher Danish FDI...

  15. Prioritization and Ranking Problems Exporting Iranian Saffron

    Directory of Open Access Journals (Sweden)

    Reza Askandari

    2013-10-01

    Full Text Available The main objective of this study is to prioritize and rank problems exporting Iranian saffron. Based on a comprehensive review of the literature on issues related to data and information collected from questionnaires, with 816% reliability is used. In this study, the sample of managers and sales and marketing company is exporting Iranian saffron is the sample size of 231 subjects. The results of this study are positive and significant relationship between the dependent variable and the independent variables of export performance of export barriers exist.

  16. 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.

  17. 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-

  18. Cholesterol-induced suppression of membrane elastic fluctuations at the atomistic level.

    Science.gov (United States)

    Molugu, Trivikram R; Brown, Michael F

    2016-09-01

    Applications of solid-state NMR spectroscopy for investigating the influences of lipid-cholesterol interactions on membrane fluctuations are reviewed in this paper. Emphasis is placed on understanding the energy landscapes and fluctuations at an emergent atomistic level. Solid-state (2)H NMR spectroscopy directly measures residual quadrupolar couplings (RQCs) due to individual C-(2)H labeled segments of the lipid molecules. Moreover, residual dipolar couplings (RDCs) of (13)C-(1)H bonds are obtained in separated local-field NMR spectroscopy. The distributions of RQC or RDC values give nearly complete profiles of the order parameters as a function of acyl segment position. Measured equilibrium properties of glycerophospholipids and sphingolipids including their binary and tertiary mixtures with cholesterol show unequal mixing associated with liquid-ordered domains. The entropic loss upon addition of cholesterol to sphingolipids is less than for glycerophospholipids and may drive the formation of lipid rafts. In addition relaxation time measurements enable one to study the molecular dynamics over a wide time-scale range. For (2)H NMR the experimental spin-lattice (R1Z) relaxation rates follow a theoretical square-law dependence on segmental order parameters (SCD) due to collective slow dynamics over mesoscopic length scales. The functional dependence for the liquid-crystalline lipid membranes is indicative of viscoelastic properties as they emerge from atomistic-level interactions. A striking decrease in square-law slope upon addition of cholesterol denotes stiffening relative to the pure lipid bilayers that is diminished in the case of lanosterol. Measured equilibrium properties and relaxation rates infer opposite influences of cholesterol and detergents on collective dynamics and elasticity at an atomistic scale that potentially affects lipid raft formation in cellular membranes. PMID:27154600

  19. 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

  20. Foreign Direct Investment and Electronics Exports: Exploratory Empirical Evidence from Malaysia's Top Five Electronics Exports

    OpenAIRE

    Tuck Cheong Tang; Koi Nyen Wong

    2007-01-01

    The foreign direct investment (FDI) has contributed significantly to Malaysia's electronics exports as well as the growth and development of the electronics industry as a result of the export-oriented industrialization initiatives undertaken since 1970s. The aim of this study is to explore the causation between FDI and electronics exports by using Malaysia''s top five electronics exports by SITC (Standard International Trade Classification) product groups. The findings show a bi-directional c...

  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. 10 CFR 590.208 - Small volume exports.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Small volume exports. 590.208 Section 590.208 Energy... WITH RESPECT TO THE IMPORT AND EXPORT OF NATURAL GAS Applications for Authorization To Import or Export Natural Gas § 590.208 Small volume exports. Any person may export up to 100,000 cubic feet of natural...

  6. 21 CFR 1312.23 - Issuance of export permit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Issuance of export permit. 1312.23 Section 1312.23... CONTROLLED SUBSTANCES Exportation of Controlled Substances § 1312.23 Issuance of export permit. (a) The... regulation in § 1312.30 of this part be exported only pursuant to the issuance of an export permit....

  7. 50 CFR 14.63 - Export declaration requirements.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Export declaration requirements. 14.63... PLANTS IMPORTATION, EXPORTATION, AND TRANSPORTATION OF WILDLIFE Wildlife Declarations § 14.63 Export... exporter's agent, shall be filed with the Service prior to the export of any wildlife at the port...

  8. Exporter Behavior, Country Size and Stage of Development

    OpenAIRE

    Ana M. Fernandes; Freund, Caroline; Pierola, Martha Denisse

    2015-01-01

    This paper presents new data on the micro structure of the export sector for 45 countries and studies how exporter behavior varies with country size and stage of development. Larger countries and more developed countries have more exporters, larger exporters, and a greater share of exports controlled by the top 5 percent. The extensive margin (more firms) plays a greater role than the inte...

  9. 75 FR 44761 - Export Trade Certificate of Review

    Science.gov (United States)

    2010-07-29

    ... opportunities for sales of canned salmon in the Export Markets, selling strategies for the Export Markets, sales... International Trade Administration Export Trade Certificate of Review ACTION: Notice of Application for an Export Trade Certificate of Review From Canned Wild Salmon Export Council, LLC (``CWSEC''). SUMMARY:...

  10. 75 FR 35441 - Export Trade Certificate of Review

    Science.gov (United States)

    2010-06-22

    ...; joint ventures; shipping; export management; export licensing; advertising; documentation and services... International Trade Administration Export Trade Certificate of Review ACTION: Notice of Issuance of an Export Trade Certificate of Review to EFS International Corporation/DBA: EFS Global Trade and Export...

  11. [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

  12. The Hypolipidemic Agent Guggulsterone Regulates the Expression of Human Bile Salt Export Pump: Dominance of Transactivation over Farsenoid X Receptor-Mediated Antagonism

    OpenAIRE

    Deng, Ruitang; Yang, Dongfang; Radke, Amy; Yang, Jian; Yan, Bingfang

    2006-01-01

    Conversion of cholesterol to bile acids in the liver is initiated by the rate-limiting enzyme cholesterol 7α-hydroxylase (CYP7A1) and excretion of bile acids from the liver is mediated by the bile salt export pump (BSEP). The expression of CYP7A1 and BSEP is coordinately regulated by a negative feedback and positive feed-forward mechanism, respectively, through bile acid-mediated activation of farsenoid X receptor (FXR). It is well established that hypolipidemic agent guggulsterone is an FXR ...

  13. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  14. 78 FR 18814 - Amendment to the Export Administration Regulations: List of Items Classified Under Export Control...

    Science.gov (United States)

    2013-03-28

    ... controlled for export because the items provide at least a significant military or intelligence advantage to... Bureau of Industry and Security 15 CFR Part 774 RIN 0694-AF73 Amendment to the Export Administration Regulations: List of Items Classified Under Export Control Classification 0Y521 Series--Biosensor...

  15. 78 FR 12719 - President's Export Council: Meeting of the President's Export Council

    Science.gov (United States)

    2013-02-25

    ... expansion of U.S. exports. Topics may include the Administration's ``Doing Business in Africa'' campaign... International Trade Administration President's Export Council: Meeting of the President's Export Council AGENCY: International Trade Administration, U.S. Department of Commerce. ACTION: Notice of an Open Meeting. SUMMARY:...

  16. 15 CFR 30.3 - Electronic Export Information filer requirements, parties to export transactions, and...

    Science.gov (United States)

    2010-01-01

    ... that all information needed for reporting to the AES, including correct export licensing information... requirements set forth in 15 CFR 758.3 of the EAR. (2) Authorized agent responsibilities. In a routed export... applicant on the license in certain routed export transactions (see 15 CFR 758.3 of the EAR). Therefore,...

  17. Threshold effects and cellular recognition. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Rando, R R

    1980-01-01

    In the first year we focused on developing the techniques required for the successful incorporation of synthetic glycolipids into cells. To these ends a new water-soluble spacer group (8-amino-3-6-dioxaoctanoic acid) was developed and incorporated into the cholesterol based synthetic glycolipids. These glycolipids could be incorporated into liposomes, rendering them susceptible to aggregation by the appropriate lectin. They also allowed us to define the minimal distance between the sugar moiety and membrane required for agglutination. Finally and most importantly, we were able to functionally incorporate these new glycolipids in cells and render them agglutinable with the appropriate lectins. Functional incorporation does not occur with glycolipids bearing hydropholic spacer groups. We are now in a position to begin using the new glycolipids to answer questions about the roles of cell surface sugars in cellular recognition, which is the subject of this renewal proposal.

  18. Probing the effect of elevated cholesterol on the mechanical properties of membrane-cytoskeleton by optical tweezers

    Science.gov (United States)

    Rajkumar, Arun S.; Muley, Ajit; Chatterjee, Suvro; Jaffar Ali, B. M.

    2010-08-01

    The composition of the cell membrane and the surrounding physiological factors determine the nature and dynamics of membrane-cytoskeleton coupling. Mechanical strength of a cell is mainly derived from such coupling. In this article, we investigate the effect of extra cellular cholesterol on the membrane-cytoskelaton connectivity of single cell endothelium and consequent remodeling of its mechanical properties. Using optical tweezers as a force probe, we have measured membrane stiffness (km), membrane microviscosity (ηeff ) and the two-dimensional shear modulus (G'(f)) as a function of extracellular cholesterol in the range of 0.1mM to 6mM. We find that membrane stiffness and shear modulus are dependent on cholesterol-induced membrane-cytoskeletal organization. Further, by disrupting the membranecytoskeletal connectivity with Cytochalasin D, an actin delpolymerizing molecule, we recover pure membrane behaviour devoid of any cytoskeleton attachment. However, behaviour of ηeff was found to be unaffected by disruption of membrane-cytoskeleton organization. We infer that cholesterol is playing a distinct role in modulating membrane organization and membrane-cytoskeleton connectivity independently. We further discuss implications of our approach in characterizing cellular mechanics.

  19. Nuclear exports and international cooperation

    International Nuclear Information System (INIS)

    Canada's nuclear export policy together with its non-proliferation and safeguards policy embrace both the country's desire to promote international cooperation in the peaceful uses of nuclear energy and its effort to minimize the risk of further proliferation of nuclear weapons. This policy reflects the belief that only if Canadian parliamentary and public opinion can be convinced that Canada's nuclear exports will not contribute to nuclear proliferation will the long-term health of the country's nuclear industry be assured. Canada requires a political commitment to non-proliferation from its nuclear partners, and looks to the IAEA to administer safeguards on nuclear material of Canadian origin to guarantee that commitment. Agreements reached with its nuclear partners are in accordance with provisions of the non-proliferation treaty and include a contingency provision for fall-back safeguards if the other state should withdraw from the NPT. Provision is made for mutual agreement on reprocessing and enrichment of nuclear material. Agreements have been reached with some twenty nuclear partners, and efforts are continuing to come to new international understanding on reprocessing, enrichment, and plutonium storage

  20. Package power stations for export

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    The cheap and efficient generation of power is an essential requirement for the success and prosperity of any community and is especially important to third world countries. It is therefore logical that the more technologically advanced nations should seek to produce power stations for the developing countries. Power plant can now be designed into a packaged form that may be readily exported and commissioned. This valuable and interesting collection of papers were originally presented at a seminar organised by the Power Industries Division of the Institution of Mechanical Engineers. Topics considered include the developing world market for packaged power stations using indigenous fuels; multi-fuel systems for power generation; packaging, modularisation, and containerisation of equipment for power boilers for export; compact coal-fired industrial plant; rural woodburning power stations; biomass gasification based power generation technology and potential; gas fed reciprocating engine development; packaged heavy duty gas turbines for power generation; and criteria for assessing the appropriateness of package power technologies in developing countries.

  1. 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.

  2. 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.

  3. PEG-lipid micelles enable cholesterol efflux in Niemann-Pick Type C1 disease-based lysosomal storage disorder

    Science.gov (United States)

    Brown, Anna; Patel, Siddharth; Ward, Carl; Lorenz, Anna; Ortiz, Mauren; Duross, Allison; Wieghardt, Fabian; Esch, Amanda; Otten, Elsje G.; Heiser, Laura M.; Korolchuk, Viktor I.; Sun, Conroy; Sarkar, Sovan; Sahay, Gaurav

    2016-08-01

    2-Hydroxy-propyl-β-cyclodextrin (HPβCD), a cholesterol scavenger, is currently undergoing Phase 2b/3 clinical trial for treatment of Niemann Pick Type C-1 (NPC1), a fatal neurodegenerative disorder that stems from abnormal cholesterol accumulation in the endo/lysosomes. Unfortunately, the extremely high doses of HPβCD required to prevent progressive neurodegeneration exacerbates ototoxicity, pulmonary toxicity and autophagy-based cellular defects. We present unexpected evidence that a poly (ethylene glycol) (PEG)-lipid conjugate enables cholesterol clearance from endo/lysosomes of Npc1 mutant (Npc1‑/‑) cells. Herein, we show that distearyl-phosphatidylethanolamine-PEG (DSPE-PEG), which forms 12-nm micelles above the critical micelle concentration, accumulates heavily inside cholesterol-rich late endosomes in Npc1‑/‑ cells. This potentially results in cholesterol solubilization and leakage from lysosomes. High-throughput screening revealed that DSPE-PEG, in combination with HPβCD, acts synergistically to efflux cholesterol without significantly aggravating autophagy defects. These well-known excipients can be used as admixtures to treat NPC1 disorder. Increasing PEG chain lengths from 350 Da-30 kDa in DSPE-PEG micelles, or increasing DSPE-PEG content in an array of liposomes packaged with HPβCD, improved cholesterol egress, while Pluronic block copolymers capable of micelle formation showed slight effects at high concentrations. We postulate that PEG-lipid based nanocarriers can serve as bioactive drug delivery systems for effective treatment of lysosomal storage disorders.

  4. PEG-lipid micelles enable cholesterol efflux in Niemann-Pick Type C1 disease-based lysosomal storage disorder

    Science.gov (United States)

    Brown, Anna; Patel, Siddharth; Ward, Carl; Lorenz, Anna; Ortiz, Mauren; DuRoss, Allison; Wieghardt, Fabian; Esch, Amanda; Otten, Elsje G.; Heiser, Laura M.; Korolchuk, Viktor I.; Sun, Conroy; Sarkar, Sovan; Sahay, Gaurav

    2016-01-01

    2-Hydroxy-propyl-β-cyclodextrin (HPβCD), a cholesterol scavenger, is currently undergoing Phase 2b/3 clinical trial for treatment of Niemann Pick Type C-1 (NPC1), a fatal neurodegenerative disorder that stems from abnormal cholesterol accumulation in the endo/lysosomes. Unfortunately, the extremely high doses of HPβCD required to prevent progressive neurodegeneration exacerbates ototoxicity, pulmonary toxicity and autophagy-based cellular defects. We present unexpected evidence that a poly (ethylene glycol) (PEG)-lipid conjugate enables cholesterol clearance from endo/lysosomes of Npc1 mutant (Npc1−/−) cells. Herein, we show that distearyl-phosphatidylethanolamine-PEG (DSPE-PEG), which forms 12-nm micelles above the critical micelle concentration, accumulates heavily inside cholesterol-rich late endosomes in Npc1−/− cells. This potentially results in cholesterol solubilization and leakage from lysosomes. High-throughput screening revealed that DSPE-PEG, in combination with HPβCD, acts synergistically to efflux cholesterol without significantly aggravating autophagy defects. These well-known excipients can be used as admixtures to treat NPC1 disorder. Increasing PEG chain lengths from 350 Da-30 kDa in DSPE-PEG micelles, or increasing DSPE-PEG content in an array of liposomes packaged with HPβCD, improved cholesterol egress, while Pluronic block copolymers capable of micelle formation showed slight effects at high concentrations. We postulate that PEG-lipid based nanocarriers can serve as bioactive drug delivery systems for effective treatment of lysosomal storage disorders. PMID:27572704

  5. 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.

  6. Effects of cholesterol on plasma membrane lipid order in MCF-7 cells by two-photon microscopy

    Science.gov (United States)

    Zeng, Yixiu; Chen, Jianling; Yang, Hongqin; Wang, Yuhua; Li, Hui; Xie, Shusen

    2014-09-01

    Lipid rafts are cholesterol- and glycosphingolipids- enriched microdomains on plasma membrane surface of mammal cells, involved in a variety of cellular processes. Depleting cholesterol from the plasma membrane by drugs influences the trafficking of lipid raft markers. Optical imaging techniques are powerful tools to study lipid rafts in live cells due to its noninvasive feature. In this study, breast cancer cells MCF-7 were treated with different concentrations of MβCD to deplete cholesterol and an environmentally sensitive fluorescence probe, Laurdan was loaded to image lipid order by two-photon microscopy. The generalized polarization (GP) values were calculated to distinguish the lipid order and disorder phase. GP images and GP distributions of native and cholesterol-depleted MCF-7 cells were obtained. Our results suggest that even at low concentration (0.5 mM) of MβCD, the morphology of the MCF-7 cells changes. Small high GP areas (lipid order phase) decrease more rapidly than low GP areas (lipid disorder phase), indicating that lipid raft structure was altered more severely than nonraft domains. The data demonstrates that cholesterol dramatically affect raft coverage and plasma membrane fluidity in living cells.

  7. The deleterious effect of cholesterol and protection by quercetin on mitochondrial bioenergetics of pancreatic β-cells, glycemic control and inflammation: In vitro and in vivo studies

    Directory of Open Access Journals (Sweden)

    Catalina Carrasco-Pozo

    2016-10-01

    Full Text Available Studying rats fed high cholesterol diet and a pancreatic β-cell line (Min6, we aimed to determine the mechanisms by which quercetin protects against cholesterol-induced pancreatic β-cell dysfunction and impairments in glycemic control. Quercetin prevented the increase in total plasma cholesterol, but only partially prevented the high cholesterol diet-induced alterations in lipid profile. Quercetin prevented cholesterol-induced decreases in pancreatic ATP levels and mitochondrial bioenergetic dysfunction in Min6 cells, including decreases in mitochondrial membrane potentials and coupling efficiency in the mitochondrial respiration (basal and maximal oxygen consumption rate (OCR, ATP-linked OCR and reserve capacity. Quercetin protected against cholesterol-induced apoptosis of Min6 cells by inhibiting caspase-3 and -9 activation and cytochrome c release. Quercetin prevented the cholesterol-induced decrease in antioxidant defence enzymes from pancreas (cytosolic and mitochondrial homogenates and Min6 cells and the cholesterol-induced increase of cellular and mitochondrial oxidative status and lipid peroxidation. Quercetin counteracted the cholesterol-induced activation of the NFκB pathway in the pancreas and Min6 cells, normalizing the expression of pro-inflammatory cytokines. Quercetin inhibited the cholesterol-induced decrease in sirtuin 1 expression in the pancreas and pancreatic β-cells. Taken together, the anti-apoptotic, antioxidant and anti-inflammatory properties of quercetin, and its ability to protect and improve mitochondrial bioenergetic function are likely to contribute to its protective action against cholesterol-induced pancreatic β-cell dysfunction, thereby preserving glucose-stimulated insulin secretion (GSIS and glycemic control. Specifically, the improvement of ATP-linked OCR and the reserve capacity are important mechanisms for protection of quercetin. In addition, the inhibition of the NFκB pathway is an important

  8. Nanostructured cellular networks.

    Science.gov (United States)

    Moriarty, P; Taylor, M D R; Brust, M

    2002-12-01

    Au nanocrystals spin-coated onto silicon from toluene form cellular networks. A quantitative statistical crystallography analysis shows that intercellular correlations drive the networks far from statistical equilibrium. Spin-coating from hexane does not produce cellular structure, yet a strong correlation is retained in the positions of nanocrystal aggregates. Mechanisms based on Marangoni convection alone cannot account for the variety of patterns observed, and we argue that spinodal decomposition plays an important role in foam formation.

  9. Cellular Cardiomyoplasty: Clinical Application

    OpenAIRE

    Chachques, J. (J.); Acar, C; J. Herreros; Trainini, J. (Jorge); Prosper, F.; D’Attellis, N. (N.); Fabiani, J. N.; Carpentier, A

    2004-01-01

    Myocardial regeneration can be induced with the implantation of a variety of myogenic and angiogenic cell types. More than 150 patients have been treated with cellular cardiomyoplasty worldwide, 18 patients have been treated by our group. Cellular cardiomyoplasty seems to reduce the size and fibrosis of infarct scars, limit postischemic remodelling, and restore regional myocardial contractility. Techniques for skeletal myoblasts culture and ex vivo expansion using auto...

  10. Effect of cholesterol liposomes on calcium mobilization in muscle cells from the rabbit sphincter of Oddi

    Institute of Scientific and Technical Information of China (English)

    Xin-Jiang Wang; Jing-Guo Wei; Chun-Mei Wang; Yao-Cheng Wang; Qiu-Zhen Wu; Jia-Kuan Xu; Xiang-Xin Yang

    2002-01-01

    AIM: To analyze the influence of cholesterol liposomes onthe Ca2 + mobilization of cultured muscle cells in the rabbitsphincter of Oddi.METHODS: New Zealand rabbit was sacrificed and thesphincter of Oddi (SO) segement wes obtained aseptically.The SO segment was cut into pieces and cultured in DMEMsolution. Then the smooth muscle cells were subcultured,and the 4th-7th passage cells were used for furtherinvestigation. The intracellular Ca2 + increase was measuredunder confocal microscope after the addition of 20mmol@ L- 1KCl, 10-7 mol @ L-1 acetylcholine and 10-7 mol @ L-1cholecystokinin, and different antagonists were added toanalyze the Ca2+ mobilization pathway. After the cells wereincubated with 1g@ L-1 cholesterol liposome (CL) (rnoarratio wes ~ 2: 1 ), the intracellular Ca2+ increase wasmeasured again to determine the effect of CL on cellularCa2+ mobilization.RESULTS: The resting cellular calcium concentration ofcultured SO cell was 108 ± nmol @ L-1 21 nmol @ L-1. Theintracellular Ca2 + increases induced by 20rmmol@ L- 1 KCl, 10-7mol@ L- 1 ACh and 10-7 mol@ L- 1 CCK were 183% ± 56%, 161%± 52% and 130% ± 43%, respectively. When theextracellular Ca2+ was eliminated by 2mmol@ L-1 EGTA and5μrnol@L-1 verapamil, the intracellular Ca2+ increasesinduced by KCl, ACh and CCK were 20% ± 14%, 82% ± 21%and 104% ± 23%, respectively. After the preincubation withheparin, the Ca2+ increases were 62% ± 23% and 23% ± 19%induced by ACh and CCK, as for preincubation withprocaine they were 72% ± 28% and 85% ± 37% induced byACh and CCK, respectively. Pretreatment with CL for 18h,the resting cellular Ca2 + concentration elevated to 152nmol@L-1 ± 26nmol@ L-1, however, the cellular Ca2+ increasepercentages in response to these agonists were 67% ± 32%,56% ± 33% and 34% ± 15%.CONCLUSION: KCl elicites the SO cellular Ca2+ increasedepends on influx of extracellular Ca2+ , ACh evoked the SOcelllular Ca2+ increase is through the mobilization ofintracellular Ca2+ pool and

  11. 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.

  12. Export - led growth or growth – driven exports? Evidence from Nigeria

    OpenAIRE

    Alimi, Santos R.; Muse, Bernard O.

    2012-01-01

    This paper examined the role of export in the economic growth process in Nigeria. Time series data ranging from 1970 to 2009 was used and the study employs unit root testing, co-integration analysis and VAR Granger Causality/Exogeneity Wald Tests to analyze annual time series data from Nigeria. The study uses three measures of export namely, Total export, Oil export and Non-Oil export. This enhances the stability and robustness of results. The unit root test showed that both economic growth a...

  13. Apical Localization of Sodium-Dependent Glucose Transporter SGLT1 is Maintained by Cholesterol and Microtubules

    OpenAIRE

    Suzuki, Takeshi; Matsuzaki, Toshiyuki; Hagiwara, Haruo; Aoki, Takeo; Tajika-Takahashi, Yukiko; Takata, Kuniaki

    2006-01-01

    A GFP-labeled sodium-dependent glucose transporter SGLT1 (SGLT-GFP) was transfected into MDCK cells. SGLT-GFP was localized at the apical membrane in confluent cells. When cellular cholesterol was depleted by methyl-β-cyclodextrin (MβCD) treatment, the localization of SGLT-GFP gradually switched from apical to whole plasma membrane. Time-lapse microscopy revealed that the effect of MβCD appeared within 30 min, and that the transition of SGLT-GFP to the whole plasma membrane was completed with...

  14. Following Intracellular Cholesterol Transport by Linear and Non-Linear Optical Microscopy of Intrinsically Fluorescent Sterols

    DEFF Research Database (Denmark)

    Wustner, D.

    2012-01-01

    analysis like pixel-wise bleach rate fitting and multiphoton image correlation spectroscopy are introduced. Several applications of the new technology including observation of vectorial sterol trafficking in polarized human hepatoma cells for investigation of reverse cholesterol transport are presented....... the cellular movement of this essential lipid molecule. In this article, a survey of the various methods being used for analysis of sterol trafficking is given. Various classical biochemical methods are presented and their suitability for analysis of sterol trafficking is assessed. Special emphasis...

  15. 77 FR 13990 - Export Sales Reporting Requirements

    Science.gov (United States)

    2012-03-08

    ... quantity, destination, and marketing year of all pork and DDG export sales, changes in sales, and shipments... public to obtain information on export sales activity until the actual shipments had taken place... length(s) of cotton. Mixed wheat shall be considered to be the predominant wheat class of the blend....

  16. China Not the Only Rare Earth Exporter

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Since China announced it was reducing exports of rare earth,there have been continuous voices in the international community demanding China expand exports or seek alternative resources.The United States has also complained to the WTO that China is hoarding the commodity.

  17. 27 CFR 28.144 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.144... § 28.144 Export marks. (a) General Requirement. In addition to the marks and brands required to be... brewer shall mark the word “Export” on each container or case of beer, or the words “Beer concentrate...

  18. 27 CFR 28.123 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.123..., or Transportation to a Manufacturing Bonded Warehouse § 28.123 Export marks. (a) General. In addition... filled under the provisions of part 24 of this chapter, the proprietor shall mark the word “Export”...

  19. The Export Quotas for Next Year

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>China’s Ministry of Commerce recently announced the 2006 export quotas for some metals commodities. According to the document, China’s export quotas for tungsten and its products will be 15,800 tons. For antimony and its products, the quotas will be

  20. The Decline in China Textile Exports Narrowed

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This is a crucial moment for China’s textile export industry, which is in the midst of deep economic downturn. In the January-Novem- ber 2009 period, the decline in accumulated textile and apparel exports was being constantly reduced and the tendency of rebound is

  1. 9 CFR 352.16 - Exports.

    Science.gov (United States)

    2010-01-01

    ... CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.16 Exports. This shall be conducted in accordance with the provisions contained in 9 CFR 322.1 through 322.5. ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Exports. 352.16 Section 352.16...

  2. 27 CFR 28.216 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.216... Export marks. In addition to the marks and brands required to be placed on packages or other bulk... “Export” on the Government side of each case or Government head of each container before removal...

  3. 26 CFR 52.4682-5 - Exports.

    Science.gov (United States)

    2010-04-01

    ... prescribed by the Environmental Protection Agency (40 CFR part 82). (ii) The aggregate tax that would (but... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Exports. 52.4682-5 Section 52.4682-5 Internal... (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-5 Exports. (a) Overview. This section provides rules relating...

  4. 27 CFR 28.103 - Export marks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export marks. 28.103... Manufacturing Bonded Warehouse § 28.103 Export marks. (a) General. In addition to the marks and brands required... provisions of part 19 of this chapter, the proprietor shall mark the word “Export” on the Government side...

  5. 78 FR 45168 - Acquisition Regulations: Export Control

    Science.gov (United States)

    2013-07-26

    ... of Energy (DOE) published a proposed rulemaking in the Federal Register (78 FR 35195) to amend the Department of Energy Acquisition Regulation (DEAR) to add export control requirements applicable to the... Parts 925, 952 and 970 RIN 1991-AB99 Acquisition Regulations: Export Control AGENCY: Department...

  6. 27 CFR 28.30 - Export status.

    Science.gov (United States)

    2010-04-01

    ... under the appropriate provision of 19 CFR chapter I, and the required certification of deposit has been... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Export status. 28.30... Export status. (a) Distilled spirits and wines manufactured, produced, bottled in bottles packed...

  7. Home Textile Exports Show Recovery Signs

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this article we have analysed the export performance of Chinese main home textile products, including bedding products, carpet, curtain and towel based on official export data during the first eight months of 2010.Let’s first look at the background. The growth in China’s manufacturing

  8. The Silver Export Quota for 2005

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>China’s Ministry of Commerce recently announced the first lot of silver export quota for 2005. According to report, the first lot of silver export quota amounts to 2,443 tons which is 252 tons more on 2004 basis. There are 37 en-

  9. Export potential of Brazilian industrial firms

    Directory of Open Access Journals (Sweden)

    Bruno César Pino Oliveira de Araújo

    2010-12-01

    Full Text Available Most of the recent astonishing export growth in Brazil came from firms which already exported. The export base was not able to grow at the same pace. Since expanding the export base may have several positive effects on firms' productivity and size, in this paper we provide a four-level classification of Brazilian industrial firms according to their potential to export, and we identify a subset of non-exporting firms which are potential exporters. The effects of export stimulating policies may be improved by focusing more closely on these firms.O recente crescimento das exportações no Brasil se baseou fortemente naquelas firmas já exportadoras, e a base exportadora não conseguiu acompanhar o mesmo ritmo de crescimento. Considerando que expandir a base exportadora pode ter efeitos positivos sobre a produtividade e tamanho das firmas, neste artigo classificamos as firmas industriais brasileiras em quatro níveis de acordo com o potencial exportador, e especialmente identificamos um subconjunto de firmas que não exportam mas que são potenciais exportadoras. Os efeitos das políticas de promoção às exportações podem ser maximizados se elas forem focalizadas nestas firmas.

  10. Entrepreneurship, export orientation, and economic growth

    NARCIS (Netherlands)

    S.J.A. Hessels (Jolanda); A.J. van Stel (André)

    2009-01-01

    textabstractIn this paper the relationship between a country’s prevalence of new ventures and its rate of economic growth is investigated, while taking into account new ventures’ export orientation. It is generally acknowledged that new venture creation as well as export activity may both be importa

  11. Risk in A Concentrated Export Market

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The export destination of China’s home textile products are considered to be highly concentrated. This is reflected by the statistical data of the past couple of years when, the top export destination of the following products-bedding products, curtain and towel- is United States.

  12. Fixed export cost heterogeneity, trade and welfare

    DEFF Research Database (Denmark)

    Jørgensen, Jan Guldager; Schröder, Philipp J.H.

    2008-01-01

    -country intra-industry trade model where firms are of two different marginal costs types and where fixed export costs are heterogeneous across firms. This model traces many of the stylized facts of international trade. However, we find that with heterogeneous fixed export costs there exists a positive bilateral...

  13. 19 CFR 18.43 - Indirect exportation.

    Science.gov (United States)

    2010-04-01

    ... loading, sealing or labeling, and affixing of TIR plates. He shall remove one voucher from the carnet... container or road vehicle to the port of actual exportation. (c) At the port of actual exportation, the carnet and the container (or heavy or bulky goods) or road vehicle shall be presented to the...

  14. 27 CFR 24.292 - Exported wine.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Exported wine. 24.292... OF THE TREASURY LIQUORS WINE Removal, Return and Receipt of Wine Removals Without Payment of Tax § 24.292 Exported wine. (a) General. Wine may be removed from a bonded wine premises without payment of...

  15. Potentials in Asian Export Credit Cooperation

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    "Mekong River Regional Development Project advocated by Asian Development Bank (ADB) has been implemented. Trans-Asia Railway and Trans-Asia Highway are being discussed. It is a good opportunity for Asian Export Credit Agencies (ECAs) to cooperate and financing these large crossboarder projects."On May 11, at the 10th Annual Meeting of Asian Export Credit Agencies,

  16. 75 FR 69573 - Export Enforcement Coordination Center

    Science.gov (United States)

    2010-11-15

    ..., employees, or agents, or any other person. (Presidential Sig.) THE WHITE HOUSE, November 9, 2010. [FR Doc... Documents#0;#0; ] Executive Order 13558 of November 9, 2010 Export Enforcement Coordination Center By the... Homeland Security for administrative purposes, an interagency Federal Export Enforcement...

  17. Export Specialisation and Local Economic Growth

    NARCIS (Netherlands)

    Naude, Wim; Bosker, Maarten; Matthee, Marianne

    2010-01-01

    This paper aims to provide empirical evidence on whether export specialization or diversification is better for local economic growth. Using export data from 354 magisterial districts of South Africa for 1996 and 2001 we estimate spatial growth regressions that include measures of the degree of expo

  18. Textile Exports to Japan Witnessing a Downturn

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    China textile and apparel exports to Japan was witnessing a downturn in all statistics of China Customs and Japan METI in the Jan.-Apr. 2010 period. Exports to Japan this year later will face more pressure as gains in Japan’s consumption could moderate due to a lackluster jobs market and debt crisis.

  19. 7 CFR 945.14 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 945.14 Section 945.14 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... COUNTIES IN IDAHO, AND MALHEUR COUNTY, OREGON Order Regulating Handling Definitions § 945.14 Export....

  20. 7 CFR 958.14 - Export.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Export. 958.14 Section 958.14 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... IN IDAHO, AND MALHEUR COUNTY, OREGON Order Regulating Handling Definitions § 958.14 Export....