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Sample records for a-dependent lysophosphatidic acid

  1. [Lysophosphatidic acid and human erythrocyte aggregation].

    Sheremet'ev, Iu A; Popovicheva, A N; Levin, G Ia

    2014-01-01

    The effects of lysophosphatidic acid on the morphology and aggregation of human erythrocytes has been studied. Morphology of erythrocytes and their aggregates were studied by light microscopy. It has been shown that lysophosphatidic acid changes the shape of red blood cells: diskocyte become echinocytes. Aggregation of red blood cells (rouleaux) was significantly reduced in autoplasma. At the same time there is a strong aggregation of echinocytes. This was accompanied by the formation of microvesicles. Adding normal plasma to echinocytes restores shape and aggregation of red blood cells consisting of "rouleaux". A possible mechanism of action of lysophosphatidic acid on erythrocytes is discussed. PMID:25509147

  2. Lysophosphatidic acid effects on atherosclerosis and thrombosis

    Cui, Mei-Zhen

    2011-01-01

    Lysophosphatidic acid (LPA) has been found to accumulate in high concentrations in atherosclerotic lesions. LPA is a bioactive phospholipid produced by activated platelets and formed during the oxidation of LDL. Accumulating evidence suggests that this lipid mediator may serve as an important risk factor for development of atherosclerosis and thrombosis. The role of LPA in atherogenesis is supported by the evidence that LPA: stimulates endothelial cells to produce adhesion molecules and chemo...

  3. Lysophosphatidic Acid (LPA) Signaling in Vertebrate Reproduction

    Ye, Xiaoqin; Chun, Jerold

    2010-01-01

    Lysophosphatidic acid (LPA) is a cell membrane phospholipid metabolite that can act as an extracellular signal. Its effects are mediated through at least five G protein-coupled receptors (GPCRs), LPA1-5, and likely others as well. Studies in multiple species including LPA receptor-deficient mice and humans have identified or implicated important roles for receptor-mediated LPA signaling in multiple aspects of vertebrate reproduction. These include ovarian function, spermatogenesis, fertilizat...

  4. Spiroguanidine rhodamines as fluorogenic probes for lysophosphatidic acid

    Wang, Lei; Sibrian-Vazquez, Martha; Escobedo, Jorge O.; Wang, Jialu; Moore, Richard G.; Strongin, Robert M.

    2015-01-01

    Direct determination of total lysophosphatidic acid (LPA) was accomplished using newly developed spiroguanidines derived from rhodamine B as universal fluorogenic probes. Optimum conditions for the quantitative analysis of total LPA were investigated. The linear range for the determination of total LPA is up to 5 μM with a limit of detection of 0.512 μM.

  5. Lysophosphatidic acid is a chemoattractant for Dictyostelium discoideum amoebae.

    Jalink, K.; Moolenaar, W H; Duijn, B., Van

    1993-01-01

    The naturally occurring phospholipid lysophosphatidic acid (LPA) can induce a number of physiological responses in vertebrate cells, including platelet aggregation, smooth muscle contraction, and fibroblast proliferation. LPA is thought to activate a specific G-protein-coupled receptor, thereby triggering classic second messenger pathways such as stimulation of phospholipase C and inhibition of adenylate cyclase. Here we report that 1-oleoyl-LPA, at submicromolar concentrations, evokes a chem...

  6. Simple enrichment and analysis of plasma lysophosphatidic acids

    Wang, Jialu; Sibrian-Vazquez, Martha; Escobedo, Jorge O.; Lowry, Mark; Wang, Lei; Chu, Yu-Hsuan; Moore, Richard G.; Strongin, Robert M.

    2013-01-01

    A simple and highly efficient technique for the analysis of lysophosphatidic acid (LPA) subspecies in human plasma is described. The streamlined sample preparation protocol furnishes the five major LPA subspecies with excellent recoveries. Extensive analysis of the enriched sample reveals only trace levels of other phospholipids. This level of purity not only improves MS analyses, but enables HPLC post-column detection in the visible region with a commercially available fluorescent phospholip...

  7. Lysophosphatidic Acid Signaling through the Lysophosphatidic Acid-1 Receptor Is Required for Alveolarization.

    Funke, Manuela; Knudsen, Lars; Lagares, David; Ebener, Simone; Probst, Clemens K; Fontaine, Benjamin A; Franklin, Alicia; Kellner, Manuela; Kühnel, Mark; Matthieu, Stephanie; Grothausmann, Roman; Chun, Jerold; Roberts, Jesse D; Ochs, Matthias; Tager, Andrew M

    2016-07-01

    Lysophosphatidic acid (LPA) signaling through one of its receptors, LPA1, contributes to both the development and the pathological remodeling after injury of many organs. Because we found previously that LPA-LPA1 signaling contributes to pulmonary fibrosis, here we investigated whether this pathway is also involved in lung development. Quantitative assessment of lung architecture of LPA1-deficient knock-out (KO) and wild-type (WT) mice at 3, 12, and 24 weeks of age using design-based stereology suggested the presence of an alveolarization defect in LPA1 KO mice at 3 weeks, which persisted as alveolar numbers increased in WT mice into adulthood. Across the ages examined, the lungs of LPA1 KO mice exhibited decreased alveolar numbers, septal tissue volumes, and surface areas, and increased volumes of the distal airspaces. Elastic fibers, critical to the development of alveolar septa, appeared less organized and condensed and more discontinuous in KO alveoli starting at P4. Tropoelastin messenger RNA expression was decreased in KO lungs, whereas expression of matrix metalloproteinases degrading elastic fibers was either decreased or unchanged. These results are consistent with the abnormal lung phenotype of LPA1 KO mice, being attributable to reduced alveolar septal formation during development, rather than to increased septal destruction as occurs in the emphysema of chronic obstructive pulmonary disease. Peripheral septal fibroblasts and myofibroblasts, which direct septation in late alveolarization, demonstrated reduced production of tropoelastin and matrix metalloproteinases, and diminished LPA-induced migration, when isolated from LPA1 KO mice. Taken together, our data suggest that LPA-LPA1 signaling is critically required for septation during alveolarization. PMID:27082727

  8. Spontaneous curvature of phosphatidic acid and lysophosphatidic acid.

    Kooijman, Edgar E; Chupin, Vladimir; Fuller, Nola L; Kozlov, Michael M; de Kruijff, Ben; Burger, Koert N J; Rand, Peter R

    2005-02-15

    The formation of phosphatidic acid (PA) from lysophosphatidic acid (LPA), diacylglycerol, or phosphatidylcholine plays a key role in the regulation of intracellular membrane fission events, but the underlying molecular mechanism has not been resolved. A likely possibility is that PA affects local membrane curvature facilitating membrane bending and fission. To examine this possibility, we determined the spontaneous radius of curvature (R(0p)) of PA and LPA, carrying oleoyl fatty acids, using well-established X-ray diffraction methods. We found that, under physiological conditions of pH and salt concentration (pH 7.0, 150 mM NaCl), the R(0p) values of PA and LPA were -46 A and +20 A, respectively. Thus PA has considerable negative spontaneous curvature while LPA has the most positive spontaneous curvature of any membrane lipid measured to date. The further addition of Ca(2+) did not significantly affect lipid spontaneous curvature; however, omitting NaCl from the hydration buffer greatly reduced the spontaneous curvature of PA, turning it into a cylindrically shaped lipid molecule (R(0p) of -1.3 x 10(2) A). Our quantitative data on the spontaneous radius of curvature of PA and LPA at a physiological pH and salt concentration will be instrumental in developing future models of biomembrane fission. PMID:15697235

  9. Lysophosphatidic Acid (LPA Signaling in Human and Ruminant Reproductive Tract

    Izabela Wocławek-Potocka

    2014-01-01

    Full Text Available Lysophosphatidic acid (LPA through activating its G protein-coupled receptors (LPAR 1–6 exerts diverse cellular effects that in turn influence several physiological processes including reproductive function of the female. Studies in various species of animals and also in humans have identified important roles for the receptor-mediated LPA signaling in multiple aspects of human and animal reproductive tract function. These aspects range from ovarian and uterine function, estrous cycle regulation, early embryo development, embryo implantation, decidualization to pregnancy maintenance and parturition. LPA signaling can also have pathological consequences, influencing aspects of endometriosis and reproductive tissue associated tumors. The review describes recent progress in LPA signaling research relevant to human and ruminant reproduction, pointing at the cow as a relevant model to study LPA influence on the human reproductive performance.

  10. Inhibition of lysophospholipase D activity by unsaturated lysophosphatidic acids or seed extracts containing 1-linoleoyl and 1-oleoyl lysophosphatidic acid.

    Liu, Xi-Wen; Sok, Dai-Eun; Yook, Hong-Sun; Sohn, Cheon-Bae; Chung, Young-Jin; Kim, Mee Ree

    2007-10-17

    Lysophospholipase D (lysoPLD), generating lipid mediator lysophosphatidic acid (LPA) from lysophosphatidyclcholine (LPC), is known to be inhibited by lysophosphatidic acids. Meanwhile, some plant lipids are known to contain lysophospholipids as minor components. Therefore, it is interesting to test whether edible seed samples, rich in phospholipids, may contain lysophospholipids, which express a strong inhibition of lysoPLD activity. First, the structural importance of fatty acyl group in LPAs was examined by determining the inhibitory effect of various LPAs on bovine lysoPLD activity. The most potent in the inhibition of lysoPLD activity was linoleoyl-LPA ( K i, 0.21 microM), followed by arachidonoyl-LPA ( K i, 0.55 microM), oleoyl-LPA ( K i, 1.2 microM), and palmitoyl-LPA ( K i, 1.4 microM), based on the fluoresecent assay. The same order of inhibitory potency among LPA analogs with different acyl chains was also found in the spectrophotometric assay. Subsequently, the extracts of 12 edible seeds were screened for the inhibition of lysoPLD activity using both spectrophotometric and fluorescent assays. Among seed extracts tested, the extract from soybean seed, sesame seed, or sunflower seed (30 mg seed weight/mL) was found to exhibit a potent inhibition (>80%) of lysoPLD activity. In further study employing ESI-MS/MS analysis, major LPA components in seed extracts were identified to be 1-linoleoyl LPA, 1-oleoyl LPA, and 1-palmitoyl LPA with 1-linoleoyl LPA being more predominant. Thus, the potent inhibition of lysoPLD activity by seed extracts might be ascribed to the presence of LPA with linoleoyl group rather than other acyl chains. PMID:17887800

  11. Lysophosphatidic acid metabolism and elimination in cardiovascular disease

    Salous, Abdelghaffar Kamal

    The bioactive lipids lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P) are present in human and mouse plasma at a concentration of ~0.1-1 microM and regulate physiological and pathophysiological processes in the cardiovascular system including atherothrombosis, intimal hyperplasia, and immune function, edema formation, and permeability. PPAP2B, the gene encoding LPP3, a broad activity integral membrane enzyme that terminates LPA actions in the vasculature, has a single nucleotide polymorphism that been recently associated with coronary artery disease risk. The synthesis and signaling of LPA and S1P in the cardiovascular system have been extensively studied but the mechanisms responsible for their elimination are less well understood. The broad goal of this research was to examine the role of LPP3 in the termination of LPA signaling in models of cardiovascular disease involving vascular wall cells, investigate the role of LPP3 in the elimination of plasma LPA, and further characterize the elimination of plasma LPA. The central hypothesis is that LPP3 plays an important role in attenuating the pathological responses to LPA signaling and that it mediates the elimination of exogenously applied bioactive lipids from the plasma. These hypotheses were tested using molecular biological approaches, in vitro studies, synthetic lysophospholipid mimetics, modified surgical procedures, and mass spectrometry assays. My results indicated that LPP3 played a critical role in attenuating LPA signaling mediating the pathological processes of intimal hyperplasia and vascular leak in mouse models of disease. Additionally, enzymatic inactivation of lysophospholipids by LPP and PLA enzymes in the plasma was not a primary mechanism for the rapid elimination of plasma LPA and S1P. Instead, evidence strongly suggested a transcellular uptake mechanism by hepatic non-parenchymal cells as the predominant mechanism for elimination of these molecules. These results support a model in

  12. What makes the bioactive lipids phosphatidic acid and lysophosphatidic acid so special?

    Kooijman, Edgar E; Carter, Karen M; van Laar, Emma G; Chupin, Vladimir; Burger, Koert N J; de Kruijff, Ben

    2005-12-27

    Phosphatidic acid and lysophosphatidic acid are minor but important anionic bioactive lipids involved in a number of key cellular processes, yet these molecules have a simple phosphate headgroup. To find out what is so special about these lipids, we determined the ionization behavior of phosphatidic acid (PA) and lysophosphatidic acid (LPA) in extended (flat) mixed lipid bilayers using magic angle spinning 31P NMR. Our data show two surprising results. First, despite identical phosphomonoester headgroups, LPA carries more negative charge than PA when present in a phosphatidylcholine bilayer. Dehydroxy-LPA [1-oleoyl-3-(phosphoryl)propanediol] behaves in a manner identical to that of PA, indicating that the difference in negative charge between LPA and PA is caused by the hydroxyl on the glycerol backbone of LPA and its interaction with the phosphomonoester headgroup. Second, deprotonation of phosphatidic acid and lysophosphatidic acid was found to be strongly stimulated by the inclusion of phosphatidylethanolamine in the bilayer, indicating that lipid headgroup charge depends on local lipid composition and will vary between the different subcellular locations of (L)PA. Our findings can be understood in terms of a hydrogen bond formed within the phosphomonoester headgroup of (L)PA and its destabilization by competing intra- or intermolecular hydrogen bonds. We propose that this hydrogen bonding property of (L)PA is involved in the various cellular functions of these lipids. PMID:16363814

  13. Pleiotropic activity of lysophosphatidic acid in bone metastasis.

    Peyruchaud, Olivier; Leblanc, Raphael; David, Marion

    2013-01-01

    Bone is a common metastatic site for solid cancers. Bone homeostasis is tightly regulated by intimate cross-talks between osteoblast (bone forming cells) and osteoclasts (bone resorbing cells). Once in the bone microenvironment, metastatic cells do not alter bone directly but instead perturb the physiological balance of the bone remodeling process controlled by bone cells. Tumor cells produce growth factors and cytokines stimulating either osteoclast activity leading to osteolytic lesions or osteoblast function resulting in osteoblastic metastases. Growth factors, released from the resorbed bone matrix or throughout osteoblastic bone formation, sustain tumor growth. Therefore, bone metastases are the sites of vicious cycles wherein tumor growth and bone metabolism sustain each other. Lysophosphatidic acid (LPA) promotes the growth of primary tumors and metastatic dissemination of cancer cells. We have shown that by acting on cancer cells via the contribution of blood platelets and the LPA-producing enzyme Autotaxin (ATX), LPA promotes the progression of osteolytic bone metastases in animal models. In the light of recent reports it would appear that the role of LPA in the context of bone metastases is complex involving multiple sources of lipid combined with direct and indirect effects on target cells. This review will present our current knowledge on the LPA/ATX axis involvement in osteolytic and osteoblastic skeletal metastases and will discuss the potential activity of LPA upstream and downstream metastasis seeding of cancer cells to bone as well as its implication in cancer induced bone pain. This article is part of a Special Issue entitled Advances in Lysophospholipid Research. PMID:22710393

  14. The autotaxin-lysophosphatidic acid–lysophosphatidic acid receptor cascade: proposal of a novel potential therapeutic target for treating glioblastoma multiforme

    Tabuchi, Sadaharu

    2015-01-01

    Glioblastoma multiforme (GBM) is the most malignant tumor of the central nervous system (CNS). Its prognosis is one of the worst among all cancer types, and it is considered a fatal malignancy, incurable with conventional therapeutic strategies. As the bioactive multifunctional lipid mediator lysophosphatidic acid (LPA) is well recognized to be involved in the tumorigenesis of cancers by acting on G-protein-coupled receptors, LPA receptor (LPAR) antagonists and LPA synthesis inhibitors have b...

  15. Mechanisms of lysophosphatidic acid (LPA) mediated stimulation of intestinal apical Cl−/OH− exchange

    Singla, Amika; Dwivedi, Alka; Saksena, Seema; Gill, Ravinder K.; Alrefai, Waddah A.; RAMASWAMY, KRISHNAMURTHY; Dudeja, Pradeep K.

    2009-01-01

    Lysophosphatidic acid (LPA), a potent bioactive phospholipid, is a natural component of food products like soy and egg yolk. LPA modulates a number of epithelial functions and has been shown to inhibit cholera toxin-induced diarrhea. Antidiarrheal effects of LPA are known to be mediated by inhibiting chloride secretion. However, the effects of LPA on chloride absorption in the mammalian intestine are not known. The present studies examined the effects of LPA on apical Cl−/OH− exchangers known...

  16. G-Protein-Coupled Lysophosphatidic Acid Receptors and Their Regulation of AKT Signaling

    Anjum Riaz; Ying Huang; Staffan Johansson

    2016-01-01

    A hallmark of G-protein-coupled receptors (GPCRs) is their ability to recognize and respond to chemically diverse ligands. Lysophospholipids constitute a relatively recent addition to these ligands and carry out their biological functions by activating G-proteins coupled to a large family of cell-surface receptors. This review aims to highlight salient features of cell signaling by one class of these receptors, known as lysophosphatidic acid (LPA) receptors, in the context of phosphatidylinos...

  17. Adipose-specific disruption of autotaxin enhances nutritional fattening and reduces plasma lysophosphatidic acid

    Dusaulcy, Rodolphe; Rancoule, Chloé; Grès, Sandra; Wanecq, Estelle; Colom, André; Guigné, Charlotte; van Meeteren, Laurens A.; Moolenaar, Wouter H.; Valet, Philippe; Saulnier-Blache, Jean Sébastien

    2011-01-01

    Autotaxin (ATX) is a secreted lysophospholipase D that generates the lipid mediator lysophosphatidic acid (LPA). ATX is secreted by adipose tissue and its expression is enhanced in obese/insulin-resistant individuals. Here, we analyzed the specific contribution of adipose-ATX to fat expansion associated with nutritional obesity and its consequences on plasma LPA levels. We established ATXF/F/aP2-Cre (FATX-KO) transgenic mice carrying a null ATX allele specifically in adipose tissue. FATX-KO m...

  18. Lysophosphatidic Acid Receptor Is a Functional Marker of Adult Hippocampal Precursor Cells

    Tara L. Walker; Rupert W. Overall; Steffen Vogler; Alex M. Sykes; Susann Ruhwald; Daniela Lasse; Muhammad Ichwan; Klaus Fabel; Gerd Kempermann

    2016-01-01

    Summary Here, we show that the lysophosphatidic acid receptor 1 (LPA1) is expressed by a defined population of type 1 stem cells and type 2a precursor cells in the adult mouse dentate gyrus. LPA1, in contrast to Nestin, also marks the quiescent stem cell population. Combining LPA1-GFP with EGFR and prominin-1 expression, we have enabled the prospective separation of both proliferative and non-proliferative precursor cell populations. Transcriptional profiling of the isolated proliferative pre...

  19. Lysophosphatidic Acid Stimulates MCP-1 Secretion from C2C12 Myoblast

    Tamotsu Tsukahara; Hisao Haniu

    2012-01-01

    Chemokines are regulatory proteins that play an important role in muscle cell migration and proliferation. In this study, C2C12 cells treated with lysophosphatidic acid (LPA) showed an increase in endogenous monocyte chemotactic protein-1 (MCP-1) expression and secretion. LPA is a naturally occurring bioactive lysophospholipid with hormone- and growth-factor-like activities. LPA is produced by activated platelets, cytokine-stimulated leukocytes, and possibly by other cell types. However, the ...

  20. Platelet activation and platelet-monocyte aggregate formation by the atherosclerotic plaque lipid lysophosphatidic acid

    Haserück, Nadine

    2007-01-01

    Oxidized LDL and platelets play a central role in the pathogenesis of atherosclerosis and ischemic cardiovascular diseases. Lysophosphatidic acid (LPA) is a thrombogenic substance that accumulates in mildly-oxidized LDL and in human atherosclerotic lesions, and is responsible for the initial platelet activation, shape change, induced by mildly-oxidized LDL and extracts of lipid-rich atherosclerotic plaques (Siess et al., 1999 Proc Natl Acad Sci USA 1999). LPA directly induced platelet shape c...

  1. Lysophosphatidic Acid Signaling in Late Cleavage and Blastocyst Stage Bovine Embryos

    Ana Catarina Torres; Dorota Boruszewska; Mariana Batista; Ilona Kowalczyk-Zieba; Patricia Diniz; Emilia Sinderewicz; Jean Sebastian Saulnier-Blache; Izabela Woclawek-Potocka; Luis Lopes-da-Costa

    2014-01-01

    Lysophosphatidic acid (LPA) is a known cell signaling lipid mediator in reproductive tissues. In the cow, LPA is involved in luteal and early pregnancy maintenance. Here, we evaluated the presence and role of LPA in bovine early embryonic development. In relevant aspects, bovine embryos reflect more closely the scenario occurring in human embryos than the mouse model. Transcription of mRNA and protein expression of enzymes involved in LPA synthesis (ATX and cPLA2) and of LPA receptors (LPAR1–...

  2. Mutations of lysophosphatidic acid receptor-1 gene during progression of lung tumors in rats

    Lysophosphatidic acid (LPA) is a bioactive phospholipid that stimulates cell proliferation, migration, and protects cells from apoptosis. It interacts with specific G protein-coupled transmembrane receptors. In this study, mutations of lysophosphatidic acid receptor-1 (LPA1) gene were investigated to clarify the possible molecular mechanisms underlying the development of lung tumors induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats. Male Wistar rats, 6 weeks of age, were given 2000 ppm BHP in their drinking water for 12 weeks and then maintained without further treatment until sacrifice at 25 weeks. Genomic DNAs were extracted from paraffin-embedded tissues and exons 2-4 were examined for mutations, using polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. No LPA1 mutations were detected in 15 hyperplasias, but 2 out of 12 adenomas (16.7%) and 7 out of 17 adenocarcinomas (41.2%). These results suggest that mutations of LPA1 gene may be involved in the acquisition of growth advantage from adenomas to adenocarcinomas in lung carcinogenesis induced in rats by BHP.

  3. Lysophosphatidic acid regulates adhesion molecules and enhances migration of human oral keratinocytes.

    Thorlakson, Hong H; Schreurs, Olav; Schenck, Karl; Blix, Inger J S

    2016-04-01

    Oral keratinocytes are connected via cell-to-cell adhesions to protect underlying tissues from physical and bacterial damage. Lysophosphatidic acids (LPAs) are a family of phospholipid mediators that have the ability to regulate gene expression, cytoskeletal rearrangement, and cytokine/chemokine secretion, which mediate proliferation, migration, and differentiation. Several forms of LPA are found in saliva and gingival crevicular fluid, but it is unknown how they affect human oral keratinocytes (HOK). The aim of the present study was therefore to examine how different LPA forms affect the expression of adhesion molecules and the migration and proliferation of HOK. Keratinocytes were isolated from gingival biopsies obtained from healthy donors and challenged with different forms of LPA. Quantitative real-time RT-PCR, immunocytochemistry, and flow cytometry were used to analyze the expression of adhesion molecules. Migration and proliferation assays were performed. Lysophosphatidic acids strongly promoted expression of E-cadherin and occludin mRNAs and translocation of E-cadherin protein from the cytoplasm to the membrane. Occludin and claudin-1 proteins were up-regulated by LPA. Migration of HOK in culture was increased, but proliferation was reduced, by the addition of LPA. This indicates that LPA can have a role in the regulation of the oral epithelial barrier by increasing the expression of adhesion molecules of HOK, by promotion of migration and by inhibition of proliferation. PMID:26913569

  4. Lysophosphatidic Acid Receptor Is a Functional Marker of Adult Hippocampal Precursor Cells

    Tara L. Walker

    2016-04-01

    Full Text Available Here, we show that the lysophosphatidic acid receptor 1 (LPA1 is expressed by a defined population of type 1 stem cells and type 2a precursor cells in the adult mouse dentate gyrus. LPA1, in contrast to Nestin, also marks the quiescent stem cell population. Combining LPA1-GFP with EGFR and prominin-1 expression, we have enabled the prospective separation of both proliferative and non-proliferative precursor cell populations. Transcriptional profiling of the isolated proliferative precursor cells suggested immune mechanisms and cytokine signaling as molecular regulators of adult hippocampal precursor cell proliferation. In addition to LPA1 being a marker of this important stem cell population, we also show that the corresponding ligand LPA is directly involved in the regulation of adult hippocampal precursor cell proliferation and neurogenesis, an effect that can be attributed to LPA signaling via the AKT and MAPK pathways.

  5. Cloning and identification of the human LPAAT-zeta gene, a novel member of the lysophosphatidic acid acyltransferase family.

    Li, Dan; Yu, Long; Wu, Hai; Shan, Yuxi; Guo, Jinhu; Dang, Yongjun; Wei, Youheng; Zhao, Shouyuan

    2003-01-01

    Lysophosphatidic acid (LPA) is a naturally occurring component of phospholipid and plays a critical role in the regulation of many physiological and pathophysiological processes including cell growth, survival, and pro-angiogenesis. LPA is converted to phosphatidic acid by the action of lysophosphatidic acid acyltransferase (LPAAT). Five members of the LPAAT gene family have been detected in humans to date. Here, we report the identification of a novel LPAAT member, which is designated as LPAAT-zeta. LPAAT-zeta was predicted to encode a protein consisting of 456 amino acid residues with a signal peptide sequence and the acyltransferase domain. Northern blot analysis showed that LPAAT-zeta was ubiquitously expressed in all 16 human tissues examined, with levels in the skeletal muscle, heart, and testis being relatively high and in the lung being relatively low. The human LPAAT-zeta gene consisted of 13 exons and is positioned at chromosome 8p11.21. PMID:12938015

  6. Lysophosphatidic Acid Alters the Expression Profiles of Angiogenic Factors, Cytokines, and Chemokines in Mouse Liver Sinusoidal Endothelial Cells

    Chia-Hung Chou; Shou-Lun Lai; Cheng-Maw Ho; Wen-Hsi Lin; Chiung-Nien Chen; Po-Huang Lee; Fu-Chuo Peng; Sung-Hsin Kuo; Szu-Yuan Wu; Hong-Shiee Lai

    2015-01-01

    Background and Aims Lysophosphatidic acid (LPA) is a multi-function glycerophospholipid. LPA affects the proliferation of hepatocytes and stellate cells in vitro, and in a partial hepatectomy induced liver regeneration model, the circulating LPA levels and LPA receptor (LPAR) expression levels in liver tissue are significantly changed. Liver sinusoidal endothelial cells (Lsecs) play an important role during liver regeneration. However, the effects of LPA on Lsecs are not well known. Thus, we ...

  7. Lysophosphatidic acid stimulates gastric cancer cell proliferation via ERK1-dependent upregulation of sphingosine kinase 1 transcription

    Ramachandran, Subramaniam; Shida, Dai; Nagahashi, Masayuki; Fang, Xianjun; Milstien, Sheldon; Takabe, Kazuaki; Spiegel, Sarah

    2010-01-01

    In MKN1 gastric cancer cells, lysophosphatidic acid (LPA) upregulates expression of sphingosine kinase 1 (SphK1) and its downregulation or inhibition suppresses LPA-mediated proliferation. Although LPA activates numerous signaling pathways downstream of its receptors, including ERK1/2, p38, JNK, and Akt, and the transactivation of the EGF receptor, pharmacological and molecular approaches demonstrated that only activation of ERK1, in addition to the CCAAT/enhancer-binding protein β (C/EBPβ) t...

  8. New metabolically stabilized analogues of lysophosphatidic acid: agonists, antagonists and enzyme inhibitors.

    Prestwich, G D; Xu, Y; Qian, L; Gajewiak, J; Jiang, G

    2005-12-01

    Lysophosphatidic acid (LPA) is a metabolically labile natural phospholipid with a bewildering array of physiological effects. We describe herein a variety of long-lived receptor-specific agonists and antagonists for LPA receptors. Several LPA and PA (phosphatidic acid) analogues also inhibit LPP (lipid phosphate phosphatase). The sn-1 or sn-2 hydroxy groups have been replaced by fluorine, difluoromethyl, difluoroethyl, O-methyl or O-hydroxyethoxy groups to give non-migrating LPA analogues that resist acyltransferases. Alkyl ether replacement of acyl esters produced lipase and acyltransferase-resistant analogues. Replacement of the bridging oxygen in the monophosphate by an alpha-monofluoromethylene-, alpha-bromomethylene- or alpha,alpha-difluoromethylenephosphonate gave phosphatase-resistant analogues. Phosphorothioate analogues with O-acyl and O-alkyl chains are potent, long-lived agonists for LPA1 and LPA3 receptors. Most recently, we have (i) prepared stabilized O-alkyl analogues of lysobisphosphatidic acid, (ii) explored the structure-activity relationship of stabilized cyclic LPA analogues and (iii) synthesized neutral head group trifluoromethylsulphonamide analogues of LPA. Through collaborative studies, we have collected data for these stabilized analogues as selective LPA receptor (ant)agonists, LPP inhibitors, TREK (transmembrane calcium channel) K+ channel agonists, activators of the nuclear transcription factor PPAR-gamma (peroxisome-proliferator-activated receptor-gamma), promoters of cell motility and survival, and radioprotectants for human B-cells. PMID:16246118

  9. Toluene diisocyanate: Induction of the autotaxin-lysophosphatidic acid axis and its association with airways symptoms

    Diisocyanates are industrial chemicals which have a wide range of applications in developed and developing countries. They are notorious lung toxicants and respiratory sensitizers. However, the mechanisms behind their adverse effects are not adequately characterized. Autotaxin (ATX) is an enzyme producing lysophosphatidic acid (LPA), and the ATX-LPA axis has been implicated in lung related inflammatory conditions and diseases, including allergic asthma, but not to toxicity of environmental low-molecular-weight chemicals. We investigated effects of toluene diisocyanate (TDI) on ATX induction in human lung epithelial cell models, and we correlated LPA-levels in plasma to biomarkers of TDI exposure in urine collected from workers exposed to < 5 ppb (parts per billion). Information on workers' symptoms was collected through interviews. One nanomolar TDI robustly induced ATX release within 10 min in vitro. A P2X7- and P2X4-dependent microvesicle formation was implicated in a rapid ATX release and a subsequent protein synthesis. Co-localization between purinergic receptors and ATX was documented by immunofluorescence and confocal microscopy. The release was modulated by monocyte chemoattractant protein-1 (MCP-1) and by extracellular ATP. In workers, we found a dose–response relationship between TDI exposure biomarkers in urine and LPA levels in plasma. Among symptomatic workers reporting “sneezing”, the LPA levels were higher than among non-symptomatic workers. This is the first report indicating induction of the ATX-LPA axis by an environmental low-molecular-weight chemical, and our data suggest a role for the ATX-LPA axis in TDI toxicity. - Highlights: • Human epithelial cells release autotaxin in response to 1 nM toluene diisocyanate (TDI). • The release involves P2X4 and P2X7 receptors and is modulated by ATP and MCP-1. • Lysophosphatidic acid (LPA) was measured in workers exposed to < 5 ppb TDI. • LPA in plasma correlated to TDI exposure

  10. Blockade of lysophosphatidic acid receptors LPAR1/3 ameliorates lung fibrosis induced by irradiation

    Highlights: → Lysophosphatidic acid (LPA) levels and its receptors LPAR1/3 transcripts were elevated during the development of radiation-induced lung fibrosis. → Lung fibrosis was obviously alleviated in mice treated with the dual LPAR1/3 antagonist, VPC12249. → VPC12249 administration effectively inhibited radiation-induced fibroblast accumulation in vivo, and suppressed LPA-induced fibroblast proliferation in vitro. → LPA-LPAR1/3 signaling regulated TGFβ1 and CTGF expressions in radiation-challenged lungs, but only influenced CTGF expression in cultured fibroblasts. → LPA-LPAR1/3 signaling induced fibroblast proliferation through a CTGF-dependent pathway, rather than through TGFβ1 activation. -- Abstract: Lung fibrosis is a common and serious complication of radiation therapy for lung cancer, for which there are no efficient treatments. Emerging evidence indicates that lysophosphatidic acid (LPA) and its receptors (LPARs) are involved in the pathogenesis of fibrosis. Here, we reported that thoracic radiation with 16 Gy in mice induced development of radiation lung fibrosis (RLF) accompanied by obvious increases in LPA release and LPAR1 and LPAR3 (LPAR1/3) transcripts. RLF was significantly alleviated in mice treated with the dual LPAR1/3 antagonist, VPC12249. VPC12249 administration effectively prolonged animal survival, restored lung structure, inhibited fibroblast accumulation and reduced collagen deposition. Moreover, profibrotic cytokines in radiation-challenged lungs obviously decreased following administration of VPC12249, including transforming growth factor β1 (TGFβ1) and connective tissue growth factor (CTGF). In vitro, LPA induced both fibroblast proliferation and CTGF expression in a dose-dependent manner, and both were suppressed by blockade of LPAR1/3. The pro-proliferative activity of LPA on fibroblasts was inhibited by siRNA directed against CTGF. Together, our data suggest that the LPA-LPAR1/3 signaling system is involved in the

  11. Blockade of lysophosphatidic acid receptors LPAR1/3 ameliorates lung fibrosis induced by irradiation

    Gan, Lu [State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu (China); Xue, Jian-Xin [Department of Thoracic Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu (China); Laboratory of Stem Cell Biology, West China Hospital, Sichuan University, Chengdu (China); Li, Xin [Department of Thoracic Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu (China); Liu, De-Song [Department of Pediatrics, Sichuan Provincial Hospital of Women and Children, Chengdu (China); Ge, Yan; Ni, Pei-Yan; Deng, Lin [State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu (China); Lu, You, E-mail: radyoulu@hotmail.com [State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu (China); Department of Thoracic Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu (China); Jiang, Wei, E-mail: wcumsjw72@hotmail.com [State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu (China); Molecular Medicine Research Center, West China Hospital, Sichuan University, Chengdu (China)

    2011-05-27

    Highlights: {yields} Lysophosphatidic acid (LPA) levels and its receptors LPAR1/3 transcripts were elevated during the development of radiation-induced lung fibrosis. {yields} Lung fibrosis was obviously alleviated in mice treated with the dual LPAR1/3 antagonist, VPC12249. {yields} VPC12249 administration effectively inhibited radiation-induced fibroblast accumulation in vivo, and suppressed LPA-induced fibroblast proliferation in vitro. {yields} LPA-LPAR1/3 signaling regulated TGF{beta}1 and CTGF expressions in radiation-challenged lungs, but only influenced CTGF expression in cultured fibroblasts. {yields} LPA-LPAR1/3 signaling induced fibroblast proliferation through a CTGF-dependent pathway, rather than through TGF{beta}1 activation. -- Abstract: Lung fibrosis is a common and serious complication of radiation therapy for lung cancer, for which there are no efficient treatments. Emerging evidence indicates that lysophosphatidic acid (LPA) and its receptors (LPARs) are involved in the pathogenesis of fibrosis. Here, we reported that thoracic radiation with 16 Gy in mice induced development of radiation lung fibrosis (RLF) accompanied by obvious increases in LPA release and LPAR1 and LPAR3 (LPAR1/3) transcripts. RLF was significantly alleviated in mice treated with the dual LPAR1/3 antagonist, VPC12249. VPC12249 administration effectively prolonged animal survival, restored lung structure, inhibited fibroblast accumulation and reduced collagen deposition. Moreover, profibrotic cytokines in radiation-challenged lungs obviously decreased following administration of VPC12249, including transforming growth factor {beta}1 (TGF{beta}1) and connective tissue growth factor (CTGF). In vitro, LPA induced both fibroblast proliferation and CTGF expression in a dose-dependent manner, and both were suppressed by blockade of LPAR1/3. The pro-proliferative activity of LPA on fibroblasts was inhibited by siRNA directed against CTGF. Together, our data suggest that the LPA-LPAR1

  12. Toluene diisocyanate: Induction of the autotaxin-lysophosphatidic acid axis and its association with airways symptoms

    Broström, Julia M. [Division of Occupational and Environmental Medicine, Lund University, SE 221 85 Lund (Sweden); Ye, Zhi-wei [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77 Stockholm (Sweden); Axmon, Anna; Littorin, Margareta; Tinnerberg, Håkan; Lindh, Christian H. [Division of Occupational and Environmental Medicine, Lund University, SE 221 85 Lund (Sweden); Zheng, Huiyuan; Ghalali, Aram; Stenius, Ulla [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77 Stockholm (Sweden); Jönsson, Bo A.G. [Division of Occupational and Environmental Medicine, Lund University, SE 221 85 Lund (Sweden); Högberg, Johan, E-mail: johan.hogberg@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE 171 77 Stockholm (Sweden)

    2015-09-15

    Diisocyanates are industrial chemicals which have a wide range of applications in developed and developing countries. They are notorious lung toxicants and respiratory sensitizers. However, the mechanisms behind their adverse effects are not adequately characterized. Autotaxin (ATX) is an enzyme producing lysophosphatidic acid (LPA), and the ATX-LPA axis has been implicated in lung related inflammatory conditions and diseases, including allergic asthma, but not to toxicity of environmental low-molecular-weight chemicals. We investigated effects of toluene diisocyanate (TDI) on ATX induction in human lung epithelial cell models, and we correlated LPA-levels in plasma to biomarkers of TDI exposure in urine collected from workers exposed to < 5 ppb (parts per billion). Information on workers' symptoms was collected through interviews. One nanomolar TDI robustly induced ATX release within 10 min in vitro. A P2X7- and P2X4-dependent microvesicle formation was implicated in a rapid ATX release and a subsequent protein synthesis. Co-localization between purinergic receptors and ATX was documented by immunofluorescence and confocal microscopy. The release was modulated by monocyte chemoattractant protein-1 (MCP-1) and by extracellular ATP. In workers, we found a dose–response relationship between TDI exposure biomarkers in urine and LPA levels in plasma. Among symptomatic workers reporting “sneezing”, the LPA levels were higher than among non-symptomatic workers. This is the first report indicating induction of the ATX-LPA axis by an environmental low-molecular-weight chemical, and our data suggest a role for the ATX-LPA axis in TDI toxicity. - Highlights: • Human epithelial cells release autotaxin in response to 1 nM toluene diisocyanate (TDI). • The release involves P2X4 and P2X7 receptors and is modulated by ATP and MCP-1. • Lysophosphatidic acid (LPA) was measured in workers exposed to < 5 ppb TDI. • LPA in plasma correlated to TDI exposure

  13. Lysophosphatidic Acid Stimulates MCP-1 Secretion from C2C12 Myoblast.

    Tsukahara, Tamotsu; Haniu, Hisao

    2012-01-01

    Chemokines are regulatory proteins that play an important role in muscle cell migration and proliferation. In this study, C2C12 cells treated with lysophosphatidic acid (LPA) showed an increase in endogenous monocyte chemotactic protein-1 (MCP-1) expression and secretion. LPA is a naturally occurring bioactive lysophospholipid with hormone- and growth-factor-like activities. LPA is produced by activated platelets, cytokine-stimulated leukocytes, and possibly by other cell types. However, the LPA analog cyclic phosphatidic acid (cPA) had no effect on the expression and secretion of MCP-1. LPA, although similar in structure to cPA, had potent inducing effects on MCP-1 expression in C2C12 cells. In this study, we showed that LPA enhanced MCP-1 mRNA expression and protein secretion in a dose-dependent manner. Taken together, these results suggest that LPA enhances MCP-1 secretion in C2C12 cells and thus may play an important role in cell proliferation. PMID:24049655

  14. The autotaxin-lysophosphatidic acid-lysophosphatidic acid receptor cascade: proposal of a novel potential therapeutic target for treating glioblastoma multiforme.

    Tabuchi, Sadaharu

    2015-01-01

    Glioblastoma multiforme (GBM) is the most malignant tumor of the central nervous system (CNS). Its prognosis is one of the worst among all cancer types, and it is considered a fatal malignancy, incurable with conventional therapeutic strategies. As the bioactive multifunctional lipid mediator lysophosphatidic acid (LPA) is well recognized to be involved in the tumorigenesis of cancers by acting on G-protein-coupled receptors, LPA receptor (LPAR) antagonists and LPA synthesis inhibitors have been proposed as promising drugs for cancer treatment. Six LPARs, named LPA1-6, are currently recognized. Among them, LPA1 is the dominant LPAR in the CNS and is highly expressed in GBM in combination with the overexpression of autotaxin (ATX), the enzyme (a phosphodiesterase, which is a potent cell motility-stimulating factor) that produces LPA.Invasion is a defining hallmark of GBM. LPA is significantly related to cell adhesion, cell motility, and invasion through the Rho family GTPases Rho and Rac. LPA1 is responsible for LPA-driven cell motility, which is attenuated by LPA4. GBM is among the most vascular human tumors. Although anti-angiogenic therapy (through the inhibition of vascular endothelial growth factor (VEGF)) was established, sufficient results have not been obtained because of the increased invasiveness triggered by anti-angiogenesis. As both ATX and LPA play a significant role in angiogenesis, similar to VEGF, inhibition of the ATX/LPA axis may be beneficial as a two-pronged therapy that includes anti-angiogenic and anti-invasion therapy. Conventional approaches to GBM are predominantly directed at cell proliferation. Recurrent tumors regrow from cells that have invaded brain tissues and are less proliferative, and are thus quite resistant to conventional drugs and radiation, which preferentially kill rapidly proliferating cells. A novel approach that targets this invasive subpopulation of GBM cells may improve the prognosis of GBM. Patients with GBM that

  15. A novel highly potent autotaxin/ENPP2 inhibitor produces prolonged decreases in plasma lysophosphatidic acid formation in vivo and regulates urethral tension.

    Hiroshi Saga

    Full Text Available Autotaxin, also known as ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2, is a secreted enzyme that has lysophospholipase D activity, which converts lysophosphatidylcholine to bioactive lysophosphatidic acid. Lysophosphatidic acid activates at least six G-protein coupled recpetors, which promote cell proliferation, survival, migration and muscle contraction. These physiological effects become dysfunctional in the pathology of cancer, fibrosis, and pain. To date, several autotaxin/ENPP2 inhibitors have been reported; however, none were able to completely and continuously inhibit autotaxin/ENPP2 in vivo. In this study, we report the discovery of a highly potent autotaxin/ENPP2 inhibitor, ONO-8430506, which decreased plasma lysophosphatidic acid formation. The IC50 values of ONO-8540506 for lysophospholipase D activity were 6.4-19 nM for recombinant autotaxin/ENPP2 proteins and 4.7-11.6 nM for plasma from various animal species. Plasma lysophosphatidic acid formation during 1-h incubation was almost completely inhibited by the addition of >300 nM of the compound to human plasma. In addition, when administered orally to rats at a dose of 30 mg/kg, the compound demonstrated good pharmacokinetics in rats and persistently inhibited plasma lysophosphatidic acid formation even at 24 h after administration. Smooth muscle contraction is a known to be promoted by lysophosphatidic acid. In this study, we showed that dosing rats with ONO-8430506 decreased intraurethral pressure accompanied by urethral relaxation. These findings demonstrate the potential of this autotaxin/ENPP2 inhibitor for the treatment of various diseases caused by lysophosphatidic acid, including urethral obstructive disease such as benign prostatic hyperplasia.

  16. The effects of aspirin on platelet function and lysophosphatidic acids depend on plasma concentrations of EPA and DHA

    Block, Robert C.; Abdolahi, Amir; Tu, Xin; Georas, Steve N.; Brenna, J. Thomas; Phipps, Richard P.; Lawrence, Peter; Mousa, Shaker A.

    2014-01-01

    Aspirin’s prevention of cardiovascular disease (CVD) events in individuals with type 2 diabetes mellitus is controversial. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and aspirin all affect the cyclooxygenase enzyme. The relationship between plasma EPA and DHA and aspirin’s effects has not been determined. Thirty adults with type 2 diabetes mellitus ingested aspirin (81 mg/day) for 7 days, then EPA+DHA (2.6 g/day) for 28 days, then both for another 7 days. Lysophosphatidic acid...

  17. Lysophosphatidic acid stimulates thrombomodulin lectin-like domain shedding in human endothelial cells

    Thrombomodulin (TM) is an anticoagulant glycoprotein highly expressed on endothelial cell surfaces. Increased levels of soluble TM in circulation have been widely accepted as an indicator of endothelial damage or dysfunction. Previous studies indicated that various proinflammatory factors stimulate TM shedding in various cell types such as smooth muscle cells and epithelial cells. Lysophosphatidic acid (LPA) is a bioactive lipid mediator present in biological fluids during endothelial damage or injury. In the present study, we first observed that LPA triggered TM shedding in human umbilical vein endothelial cells (HUVECs). By Cyflow analysis, we showed that the LPA-induced accessibility of antibodies to the endothelial growth factor (EGF)-like domain of TM is independent of matrix metalloproteinases (MMPs), while LPA-induced TM lectin-like domain shedding is MMP-dependent. Furthermore, a stable cell line expressing TM without its lectin-like domain exhibited a higher cell proliferation rate than a stable cell line expressing full-length TM. These results imply that LPA induces TM lectin-like domain shedding, which might contribute to the exposure of its EGF-like domain for EGF receptor (EGFR) binding, thereby stimulating subsequent cell proliferation. Based on our findings, we propose a novel mechanism for the exposure of TM EGF-like domain, which possibly mediates LPA-induced EGFR transactivation

  18. Lysophosphatidic acid mediates myeloid differentiation within the human bone marrow microenvironment.

    Denis Evseenko

    Full Text Available Lysophosphatidic acid (LPA is a pleiotropic phospholipid present in the blood and certain tissues at high concentrations; its diverse effects are mediated through differential, tissue specific expression of LPA receptors. Our goal was to determine if LPA exerts lineage-specific effects during normal human hematopoiesis. In vitro stimulation of CD34+ human hematopoietic progenitors by LPA induced myeloid differentiation but had no effect on lymphoid differentiation. LPA receptors were expressed at significantly higher levels on Common Myeloid Progenitors (CMP than either multipotent Hematopoietic Stem/Progenitor Cells (HSPC or Common Lymphoid Progenitors (CLP suggesting that LPA acts on committed myeloid progenitors. Functional studies demonstrated that LPA enhanced migration, induced cell proliferation and reduced apoptosis of isolated CMP, but had no effect on either HSPC or CLP. Analysis of adult and fetal human bone marrow sections showed that PPAP2A, (the enzyme which degrades LPA was highly expressed in the osteoblastic niche but not in the perivascular regions, whereas Autotaxin (the enzyme that synthesizes LPA was expressed in perivascular regions of the marrow. We propose that a gradient of LPA with the highest levels in peri-sinusoidal regions and lowest near the endosteal zone, regulates the localization, proliferation and differentiation of myeloid progenitors within the bone marrow marrow.

  19. Lysophosphatidic acid-functionalised titanium as a superior surface for supporting human osteoblast (MG63 maturation

    JP Mansell

    2012-05-01

    Full Text Available Covalent modifications of titanium with small molecules known to promote human osteoblast maturation are especially attractive in developing superior biomaterials. An important step in securing competent bone formation at implant sites is promoting the formation of mature osteoblasts, either from committed pre-osteoblasts or from their mesenchymal progenitors. To this end our research has focussed on identifying molecules that enhance human osteoblast formation and maturation and to develop ways of covalently attaching these molecules to implant surfaces so that they are more likely to withstand the rigors of the implantation process whilst still retaining their bioactivity. Herein we report the novel production of lipid-functionalised titanium using lysophosphatidic acid or a related compound, (3S 1-fluoro-3-hydroxy-4-butyl-1-phosphonate. Both lipids were especially effective at co-operating with calcitriol to promote human osteoblast maturation at these modified Ti surfaces in vitro. The novel findings presented offer enticing new developments towards the fabrication of next-generation implant devices with the potential to significantly enhance the osseointegration process and with it improvements in future prosthesis performance and longevity.

  20. Brown recluse spider (Loxosceles reclusa) venom phospholipase D (PLD) generates lysophosphatidic acid (LPA).

    Lee, Sangderk; Lynch, Kevin R

    2005-10-15

    Envenomation by the brown recluse spider (Loxosceles reclusa) may cause local dermonecrosis and, rarely, coagulopathies, kidney failure and death. A venom phospholipase, SMaseD (sphingomyelinase D), is responsible for the pathological manifestations of envenomation. Recently, the recombinant SMaseD from Loxosceles laeta was demonstrated to hydrolyse LPC (lysophosphatidylcholine) to produce LPA (lysophosphatidic acid) and choline. Therefore activation of LPA signalling pathways may be involved in some manifestations of Loxosceles envenomation. To begin investigating this idea, we cloned a full-length cDNA encoding L. reclusa SMaseD. The 305 amino acid sequence of the L. reclusa enzyme is 87, 85 and 60% identical with those of L. arizonica, L. intermedia and L. laeta respectively. The recombinant enzyme expressed in bacteria had broad substrate specificity. The lysophospholipids LPC, LPI (18:1-1-oleyol lysophosphatidylinositol), LPS, LPG (18:1-1-oleoyl-lysophosphatidylglycerol), LBPA (18:1-1-oleoyl-lysobisphosphatidic acid) (all with various acyl chains), lyso-platelet-activating factor (C16:0), cyclic phosphatidic acid and sphingomyelin were hydrolysed, whereas sphingosylphosphorylcholine, PC (phosphatidylcholine; C22:6, C20:4 and C6:0), oxidized PCs and PAF (platelet-activating factor; C16:0) were not hydrolysed. The PAF analogue, edelfosine, inhibited enzyme activity. Recombinant enzyme plus LPC (C18:1) induced the migration of A2058 melanoma cells, and this activity was blocked by the LPA receptor antagonist, VPC32183. The recombinant spider enzyme was haemolytic, but this activity was absent from catalytically inactive H37N (His37-->Asn) and H73N mutants. Our results demonstrate that Loxosceles phospholipase D hydrolyses a wider range of lysophospholipids than previously supposed, and thus the term 'SMaseD' is too limited in describing this enzyme. PMID:15926888

  1. Structurally divergent lysophosphatidic acid acyltransferases with high selectivity for saturated medium chain fatty acids from Cuphea seeds.

    Kim, Hae Jin; Silva, Jillian E; Iskandarov, Umidjon; Andersson, Mariette; Cahoon, Rebecca E; Mockaitis, Keithanne; Cahoon, Edgar B

    2015-12-01

    Lysophosphatidic acid acyltransferase (LPAT) catalyzes acylation of the sn-2 position on lysophosphatidic acid by an acyl CoA substrate to produce the phosphatidic acid precursor of polar glycerolipids and triacylglycerols (TAGs). In the case of TAGs, this reaction is typically catalyzed by an LPAT2 from microsomal LPAT class A that has high specificity for C18 fatty acids containing Δ9 unsaturation. Because of this specificity, the occurrence of saturated fatty acids in the TAG sn-2 position is infrequent in seed oils. To identify LPATs with variant substrate specificities, deep transcriptomic mining was performed on seeds of two Cuphea species producing TAGs that are highly enriched in saturated C8 and C10 fatty acids. From these analyses, cDNAs for seven previously unreported LPATs were identified, including cDNAs from Cuphea viscosissima (CvLPAT2) and Cuphea avigera var. pulcherrima (CpuLPAT2a) encoding microsomal, seed-specific class A LPAT2s and a cDNA from C. avigera var. pulcherrima (CpuLPATB) encoding a microsomal, seed-specific LPAT from the bacterial-type class B. The activities of these enzymes were characterized in Camelina sativa by seed-specific co-expression with cDNAs for various Cuphea FatB acyl-acyl carrier protein thioesterases (FatB) that produce a variety of saturated medium-chain fatty acids. CvLPAT2 and CpuLPAT2a expression resulted in accumulation of 10:0 fatty acids in the Camelina sativa TAG sn-2 position, indicating a 10:0 CoA specificity that has not been previously described for plant LPATs. CpuLPATB expression generated TAGs with 14:0 at the sn-2 position, but not 10:0. Identification of these LPATs provides tools for understanding the structural basis of LPAT substrate specificity and for generating altered oil functionalities. PMID:26505880

  2. Lysophosphatidic acid (LPA 18:1 transcriptional regulation of primary human gingival fibroblasts

    D. Roselyn Cerutis

    2014-12-01

    Full Text Available The pleiotropic, bioactive lipid lysophosphatidic acid [(LPA, 1-acyl-sn-glycerol-3-phosphate] exerts critical regulatory actions in physiology and pathophysiology in many systems. It is present in normal bodily fluids, and is elevated in pathology (1. In vivo, “LPA” exists as distinct molecular species, each having a single fatty acid of varying chain length and degree of unsaturation covalently attached to the glycerol backbone via an acyl, alkyl, or alkenyl link. These species differ in affinities for the individual LPA receptors [(LPARs, LPA1-6] and coupling to G proteins (2. However, LPA 18:1 has been and continues to be the most commonly utilized species in reported studies. The actions of “LPA” remain poorly defined in oral biology and pathophysiology. Our laboratory has addressed this knowledge gap by studying in vitro the actions of the major human salivary LPA species [18:1, 18:0, and 16:0 (3] in human oral cells (4–7. This includes gingival fibroblasts (GF, which our flow cytometry data from multiple donors found that they express LPA1-5 (6. We have also reported that these species are ten-fold elevated to pharmacologic levels in the saliva and gingival crevicular fluid obtained from patients with moderate–severe periodontitis (8. As the potential of LPA to regulate transcriptional activity had not been examined in the oral system, this study used whole human genome microarray analysis to test the hypothesis that LPA 18:1-treated human GF would show significant changes in gene transcripts relevant to their biology, wound-healing, and inflammatory responses. LPA 18:1 was found to significantly regulate a large, complex set of genes critical to GF biology in these categories and to periodontal disease. The raw data has been deposited at NCBI's GEO database as record GSE57496.

  3. Mechanisms of lysophosphatidic acid (LPA) mediated stimulation of intestinal apical Cl-/OH- exchange.

    Singla, Amika; Dwivedi, Alka; Saksena, Seema; Gill, Ravinder K; Alrefai, Waddah A; Ramaswamy, Krishnamurthy; Dudeja, Pradeep K

    2010-02-01

    Lysophosphatidic acid (LPA), a potent bioactive phospholipid, is a natural component of food products like soy and egg yolk. LPA modulates a number of epithelial functions and has been shown to inhibit cholera toxin-induced diarrhea. Antidiarrheal effects of LPA are known to be mediated by inhibiting chloride secretion. However, the effects of LPA on chloride absorption in the mammalian intestine are not known. The present studies examined the effects of LPA on apical Cl(-)/OH(-) exchangers known to be involved in chloride absorption in intestinal epithelial cells. Caco-2 cells were treated with LPA, and Cl(-)/OH(-) exchange activity was measured as DIDS-sensitive (36)Cl(-) uptake. Cell surface biotinylation studies were performed to evaluate the effect of LPA on cell surface levels of apical Cl(-)/OH(-) exchangers, downregulated in adenoma (DRA) (SLC26A3), and putative anion transporter-1 (SLC26A6). Treatment of Caco-2 cells with LPA (100 muM) significantly stimulated Cl(-)/OH(-) exchange activity. Specific agonist for LPA2 receptor mimicked the effects of LPA. LPA-mediated stimulation of Cl(-)/OH(-) exchange activity was dependent on activation of phosphatidylinositol 3-kinase/Akt signaling pathway. Consistent with the functional activity, LPA treatment resulted in increased levels of DRA on the apical membrane. Our results demonstrate that LPA stimulates apical Cl(-)/OH(-) exchange activity and surface levels of DRA in intestinal epithelial cells. This increase in Cl(-)/OH(-) exchange may contribute to the antidiarrheal effects of LPA. PMID:19910524

  4. Ginseng pharmacology: a new paradigm based on gintonin-lysophosphatidic acid receptor interactions

    Seung-Yeol eNah

    2015-10-01

    Full Text Available Ginseng, the root of Panax ginseng, is used as a traditional medicine. Despite the long history of the use of ginseng, there is no specific scientific or clinical rationale for ginseng pharmacology besides its application as a general tonic. The ambiguous description of ginseng pharmacology might be due to the absence of a predominant active ingredient that represents ginseng pharmacology. Recent studies show that ginseng abundantly contains lysophosphatidic acids (LPAs, which are phospholipid-derived growth factor with diverse biological functions including those claimed to be exhibited by ginseng. LPAs in ginseng form a complex with ginseng proteins, which can bind and deliver LPA to its cognate receptors with a high affinity. As a first messenger, gintonin produces second messenger Ca2+ via G protein-coupled LPA receptors. Ca2+ is an intracellular mediator of gintonin and initiates a cascade of amplifications for further intercellular communications by activation of Ca2+-dependent kinases, receptors, gliotransmitter and neurotransmitter release. Ginsenosides, which have been regarded as primary ingredients of ginseng, cannot elicit intracellular [Ca2+]i transients, since they lack specific cell surface receptor. However, ginsenosides exhibit non-specific ion channel and receptor regulations. This is the key characteristic that distinguishes gintonin from ginsenosides. Although the current discourse on ginseng pharmacology is focused on ginsenosides, gintonin can definitely provide a mode of action for ginseng pharmacology that ginsenosides cannot. This review article introduces a novel concept of ginseng ligand-LPA receptor interaction and proposes to establish a paradigm that shifts the focus from ginsenosides to gintonin as a major ingredient representing ginseng pharmacology.

  5. Tubular cell phenotype in HIV-associated nephropathy: role of phospholipid lysophosphatidic acid.

    Ayasolla, Kamesh R; Rai, Partab; Rahimipour, Shai; Hussain, Mohammad; Malhotra, Ashwani; Singhal, Pravin C

    2015-08-01

    Collapsing glomerulopathy and microcysts are characteristic histological features of HIV-associated nephropathy (HIVAN). We have previously reported the role of epithelial mesenchymal transition (EMT) in the development of glomerular and tubular cell phenotypes in HIVAN. Since persistent tubular cell activation of NFκB has been reported in HIVAN, we now hypothesize that HIV may be contributing to tubular cell phenotype via lysophosphatidic acid (LPA) mediated downstream signaling. Interestingly, LPA and its receptors have also been implicated in the tubular interstitial cell fibrosis (TIF) and cyst formation in autosomal dominant polycystic kidney disease (PKD). Primary human proximal tubular cells (HRPTCs) were transduced with either empty vector (EV/HRPTCs), HIV (HIV/HRPTCs) or treated with LPA (LPA/HRPTC). Immunoelectrophoresis of HIV/HRPTCs and LPA/HRPTCs displayed enhanced expression of pro-fibrotic markers: a) fibronectin (2.25 fold), b) connective tissue growth factor (CTGF; 4.8 fold), c) α-smooth muscle actin (α-SMA; 12 fold), and d) collagen I (5.7 fold). HIV enhanced tubular cell phosphorylation of ILK-1, FAK, PI3K, Akt, ERKs and P38 MAPK. HIV increased tubular cell transcriptional binding activity of NF-κB; whereas, a LPA biosynthesis inhibitor (AACOCF3), a DAG kinase inhibitor, a LPA receptor blocker (Ki16425), a NF-κB inhibitor (PDTC) and NFκB-siRNA not only displayed downregulation of a NFκB activity but also showed attenuated expression of profibrotic/EMT genes in HIV milieu. These findings suggest that LPA could be contributing to HIV-induced tubular cell phenotype via NFκB activation in HIVAN. PMID:26079546

  6. Expression of lysophosphatidic acid and its receptor in human pancreatic cancer and its clinical evaluation of diagnosis and therapy

    WANG Shao-kai; TAO Chen-jie; WANG Wei-dong; L(U)Guang-mei; GONG Yong-ling

    2011-01-01

    Lysophosphatidic acid(LPA) is a naturally occurring phospholipid with diverse effects in various cells, ranging from immediate morphological alteration to long lasting cellular function changes, such as induction of stimulation of cell proliferation, survival, drug resistance and motility. Like many other biomediators, LPA interacts with cells through specific cell surface receptors(G protein-coupled receptors). LPA1/Edg-2,LPA2/Edg-4 and LPA3/Edg-7, named as Edg/LP subfamily, are the three most common lysophosphatidic acid receptors. LPA plays a critical role as a general growth, survival and pro-angiogenic factor in the regulation of pathophysiological processes in vivo and in vitro. Recent literatures suggest that abnormalities in LPA metabolism and function in pancreatic cancer patients may contribute to the initiation and progression of the disease. Thus, LPA might be a potential target for clinical pancreatic cancer diagnosis and therapy. Herein we review the expression of LPA and its receptors in the carcinogenesis of human malignancies, with focus on human pancreatic cancer, and also clinical diagnosis and treatment has been evaluated.

  7. Clinical significance of plasma lysophosphatidic acid levels in the differential diagnosis of ovarian cancer

    Yun-Jie Zhang

    2015-01-01

    Full Text Available Objective: To investigate the value of lysophosphatidic acid (LPA in the diagnosis of ovarian cancer. Materials and Methods: We first performed a hospital-based, case-control study involving 123 ovarian cancer patients and 101 benign ovarian tumor patients, and then conducted a meta-analysis with 19 case-control studies to assess the correlation between ovarian cancer and plasma LPA levels. Results: The case-control study results demonstrated that ovarian cancer patients have increased LPA and cancer antigen (CA-125 levels compared to patients with benign ovarian tumor (LPA: Ovarian cancer vs benign ovarian tumor: 5.28 ± 1.52 vs 1.82 ± 0.77 μmol/L; CA-125: Ovarian cancer vs benign ovarian tumor: 87.17 ± 45.81 vs. 14.03 ± 10.14 U/mL, which showed statistically significant differences (both P < 0.05. LPA with advanced sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate of diagnosis excelled CA-125 in the diagnosis of ovarian cancer (both P < 0.05. The areas under the receiver operating characteristic (ROC curve in the diagnosis of ovarian cancer (LPA: 0.983; CA-125: 0.910 were statistically significant compared with the reference (both P < 0.001 and the difference of the areas of ROC curve between LPA and CA-125 in the diagnosis of ovarian cancer showed statistically significant difference (P < 0.05. The meta-analysis results suggested that plasma LPA levels were higher in ovarian cancer tissues than in benign tissues (standardized mean difference (SMD =2.36, 95% confidence interval (CI: 1.61-3.11, P < 0.001 and normal tissues (SMD = 2.32, 95% CI: 1.77-2.87, P < 0.001. Conclusion: LPA shows greater value in the diagnosis of ovarian cancer compared to CA-125 and may be employed as a biological index to diagnose ovarian cancer.

  8. Lysophosphatidic acid receptor-5 negatively regulates cellular responses in mouse fibroblast 3T3 cells

    Highlights: • LPA5 inhibits the cell growth and motile activities of 3T3 cells. • LPA5 suppresses the cell motile activities stimulated by hydrogen peroxide in 3T3 cells. • Enhancement of LPA5 on the cell motile activities inhibited by LPA1 in 3T3 cells. • The expression and activation of Mmp-9 were inhibited by LPA5 in 3T3 cells. • LPA signaling via LPA5 acts as a negative regulator of cellular responses in 3T3 cells. - Abstract: Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors (LPA1–LPA6) mediates a variety of biological functions, including cell migration. Recently, we have reported that LPA1 inhibited the cell motile activities of mouse fibroblast 3T3 cells. In the present study, to evaluate a role of LPA5 in cellular responses, Lpar5 knockdown (3T3-L5) cells were generated from 3T3 cells. In cell proliferation assays, LPA markedly stimulated the cell proliferation activities of 3T3-L5 cells, compared with control cells. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3-L5 cells were significantly higher than those of control cells. The activity levels of matrix metalloproteinases (MMPs) were measured by gelatin zymography. 3T3-L5 cells stimulated the activation of Mmp-2, correlating with the expression levels of Mmp-2 gene. Moreover, to assess the co-effects of LPA1 and LPA5 on cell motile activities, Lpar5 knockdown (3T3a1-L5) cells were also established from Lpar1 over-expressing (3T3a1) cells. 3T3a1-L5 cells increased the cell motile activities of 3T3a1 cells, while the cell motile activities of 3T3a1 cells were significantly lower than those of control cells. These results suggest that LPA5 may act as a negative regulator of cellular responses in mouse fibroblast 3T3 cells, similar to the case for LPA1

  9. Lysophosphatidic acid receptor-5 negatively regulates cellular responses in mouse fibroblast 3T3 cells

    Dong, Yan; Hirane, Miku; Araki, Mutsumi [Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Fukushima, Nobuyuki [Division of Molecular Neurobiology, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Tsujiuchi, Toshifumi, E-mail: ttujiuch@life.kindai.ac.jp [Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan)

    2014-04-04

    Highlights: • LPA{sub 5} inhibits the cell growth and motile activities of 3T3 cells. • LPA{sub 5} suppresses the cell motile activities stimulated by hydrogen peroxide in 3T3 cells. • Enhancement of LPA{sub 5} on the cell motile activities inhibited by LPA{sub 1} in 3T3 cells. • The expression and activation of Mmp-9 were inhibited by LPA{sub 5} in 3T3 cells. • LPA signaling via LPA{sub 5} acts as a negative regulator of cellular responses in 3T3 cells. - Abstract: Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors (LPA{sub 1}–LPA{sub 6}) mediates a variety of biological functions, including cell migration. Recently, we have reported that LPA{sub 1} inhibited the cell motile activities of mouse fibroblast 3T3 cells. In the present study, to evaluate a role of LPA{sub 5} in cellular responses, Lpar5 knockdown (3T3-L5) cells were generated from 3T3 cells. In cell proliferation assays, LPA markedly stimulated the cell proliferation activities of 3T3-L5 cells, compared with control cells. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3-L5 cells were significantly higher than those of control cells. The activity levels of matrix metalloproteinases (MMPs) were measured by gelatin zymography. 3T3-L5 cells stimulated the activation of Mmp-2, correlating with the expression levels of Mmp-2 gene. Moreover, to assess the co-effects of LPA{sub 1} and LPA{sub 5} on cell motile activities, Lpar5 knockdown (3T3a1-L5) cells were also established from Lpar1 over-expressing (3T3a1) cells. 3T3a1-L5 cells increased the cell motile activities of 3T3a1 cells, while the cell motile activities of 3T3a1 cells were significantly lower than those of control cells. These results suggest that LPA{sub 5} may act as a negative regulator of cellular responses in mouse fibroblast 3T3 cells, similar to the case for LPA{sub 1}.

  10. Golgi membrane fission requires the CtBP1-S/BARS-induced activation of lysophosphatidic acid acyltransferase δ.

    Pagliuso, Alessandro; Valente, Carmen; Giordano, Lucia Laura; Filograna, Angela; Li, Guiling; Circolo, Diego; Turacchio, Gabriele; Marzullo, Vincenzo Manuel; Mandrich, Luigi; Zhukovsky, Mikhail A; Formiggini, Fabio; Polishchuk, Roman S; Corda, Daniela; Luini, Alberto

    2016-01-01

    Membrane fission is an essential cellular process by which continuous membranes split into separate parts. We have previously identified CtBP1-S/BARS (BARS) as a key component of a protein complex that is required for fission of several endomembranes, including basolateral post-Golgi transport carriers. Assembly of this complex occurs at the Golgi apparatus, where BARS binds to the phosphoinositide kinase PI4KIIIβ through a 14-3-3γ dimer, as well as to ARF and the PKD and PAK kinases. We now report that, when incorporated into this complex, BARS binds to and activates a trans-Golgi lysophosphatidic acid (LPA) acyltransferase type δ (LPAATδ) that converts LPA into phosphatidic acid (PA); and that this reaction is essential for fission of the carriers. LPA and PA have unique biophysical properties, and their interconversion might facilitate the fission process either directly or indirectly (via recruitment of proteins that bind to PA, including BARS itself). PMID:27401954

  11. Hydrophilic interaction liquid chromatography-mass spectrometry of (lyso)phosphatidic acids, (lyso)phosphatidylserines and other lipid classes.

    Cífková, Eva; Hájek, Roman; Lísa, Miroslav; Holčapek, Michal

    2016-03-25

    The goal of this work is a systematic optimization of hydrophilic interaction liquid chromatography (HILIC) separation of acidic lipid classes (namely phosphatidic acids-PA, lysophosphatidic acids-LPA, phosphatidylserines-PS and lysophosphatidylserines-LPS) and other lipid classes under mass spectrometry (MS) compatible conditions. The main parameters included in this optimization are the type of stationary phases used in HILIC, pH of the mobile phase, the type and concentration of mobile phase additives. Nine HILIC columns with different chemistries (unmodified silica, modified silica using diol, 2-picolylamine, diethylamine and 1-aminoanthracene and hydride silica) are compared with the emphasis on peak shapes of acidic lipid classes. The optimization of pH is correlated with the theoretical calculation of acidobasic equilibria of studied lipid classes. The final method using the hydride column, pH 4 adjusted by formic acid and the gradient of acetonitrile and 40mmol/L of aqueous ammonium formate provides good peak shapes for all analyzed lipid classes including acidic lipids. This method is applied for the identification of lipids in real samples of porcine brain and kidney extracts. PMID:26858118

  12. Regulation of gene expression and subcellular protein distribution in MLO-Y4 osteocytic cells by lysophosphatidic acid: Relevance to dendrite outgrowth

    Waters, Katrina M.; Jon M Jacobs; Gritsenko, Marina A.; Karin, Norman J.

    2011-01-01

    Osteoblastic and osteocytic cells are highly responsive to the lipid growth factor lysophosphatidic acid (LPA) but the mechanisms by which LPA alters bone cell functions are largely unknown. A major effect of LPA on osteocytic cells is the stimulation of dendrite membrane outgrowth, a process that we predicted to require changes in gene expression and protein distribution. We employed DNA microarrays for global transcriptional profiling of MLO-Y4 osteocytic cells grown for 6 and 24 hours in t...

  13. Lipid phosphate phosphatases regulate lysophosphatidic acid production and signaling in platelets: studies using chemical inhibitors of lipid phosphate phosphatase activity.

    Smyth, Susan S; Sciorra, Vicki A; Sigal, Yury J; Pamuklar, Zehra; Wang, Zuncai; Xu, Yong; Prestwich, Glenn D; Morris, Andrew J

    2003-10-31

    Blood platelets play an essential role in ischemic heart disease and stroke contributing to acute thrombotic events by release of potent inflammatory agents within the vasculature. Lysophosphatidic acid (LPA) is a bioactive lipid mediator produced by platelets and found in the blood and atherosclerotic plaques. LPA receptors on platelets, leukocytes, endothelial cells, and smooth muscle cells regulate growth, differentiation, survival, motility, and contractile activity. Definition of the opposing pathways of synthesis and degradation that control extracellular LPA levels is critical to understanding how LPA bioactivity is regulated. We show that intact platelets and platelet membranes actively dephosphorylate LPA and identify the major enzyme responsible as lipid phosphate phosphatase 1 (LPP1). Localization of LPP1 to the platelet surface is increased by exposure to LPA. A novel receptor-inactive sn-3-substituted difluoromethylenephosphonate analog of phosphatidic acid that is a potent competitive inhibitor of LPP1 activity potentiates platelet aggregation and shape change responses to LPA and amplifies LPA production by agonist-stimulated platelets. Our results identify LPP1 as a pivotal regulator of LPA signaling in the cardiovascular system. These findings are consistent with genetic and cell biological evidence implicating LPPs as negative regulators of lysophospholipid signaling and suggest that the mechanisms involve both attenuation of lysophospholipid actions at cell surface receptors and opposition of lysophospholipid production. PMID:12909631

  14. Lipid transmitter signaling as a new target for treatment of cocaine addiction: new roles for acylethanolamides and lysophosphatidic acid.

    Orio, Laura; Pavón, Francisco Javier; Blanco, Eduardo; Serrano, Antonia; Araos, Pedro; Pedraz, María; Rivera, Patricia; Calado, Montserrat; Suárez, Juan; de Fonseca, Fernando Rodríguez

    2013-01-01

    This review analyzes the roles of lipid transmitters, especially those derived from the cleavage of membrane phospholipids, in cocaine-associated behaviors. These lipid signals are important modulators of information processing in the brain, affecting transmitter release, neural plasticity, synaptogenesis, neurogenesis, and cellular energetics. This broad range of actions makes them suitable targets for pharmaceutical development of cocaine addiction therapies because they participate in the main cellular processes underlying the neuroadaptations associated with chronic use of this psychostimulant. The main lipid transmitters reviewed here include a) acylethanolamides and acylglycerols acting on cannabinoid receptors, such as anandamide and 2-arachidonoylglycerol; b) acylethanolamides that do not act on cannabinoid receptors, such as oleoylethanolamide; c) eicosanoids derived from arachidonic acid, including prostaglandins; and d) lysophosphatidic acid, focusing on the role of its LPA-1 receptor. Direct experimental evidence for the significance of these lipids in cocaine-related behaviors is presented and discussed. Additionally, the roles for both their biosynthesis and degradation pathways, as well as the participation of their receptors, are examined. Overall, lipid transmitter signaling can offer new targets for the development of therapies for cocaine addiction. PMID:23574441

  15. Transgenic Expression of Human Lysophosphatidic Acid Receptor LPA2 in Mouse Intestinal Epithelial Cells Induces Intestinal Dysplasia.

    Michihiro Yoshida

    Full Text Available Lysophosphatidic acid (LPA acts on LPA2 receptor to mediate multiple pathological effects that are associated with tumorigenesis. The absence of LPA2 attenuates tumor progression in rodent models of colorectal cancer, but whether overexpression of LPA2 alone can lead to malignant transformation in the intestinal tract has not been studied. In this study, we expressed human LPA2 in intestinal epithelial cells (IECs under control of the villin promoter. Less than 4% of F1-generation mice had germline transmission of transgenic (TG human LPA2; as such only 3 F1 mice out of 72 genotyped had TG expression. These TG mice appeared anemic with hematochezia and died shortly after birth. TG mice were smaller in size compared with the wild type mouse of the same age and sex. Morphological analysis showed that TG LPA2 colon had hyper-proliferation of IECs resulting in increased colonic crypt depth. Surprisingly, TG small intestine had villus blunting and decreased IEC proliferation and dysplasia. In both intestine and colon, TG expression of LPA2 compromised the terminal epithelial differentiation, consistent with epithelial dysplasia. Furthermore, we showed that epithelial dysplasia was observed in founder mouse intestine, correlating LPA2 overexpression with epithelial dysplasia. The current study demonstrates that overexpression of LPA2 alone can lead to intestinal dysplasia.

  16. Lysophosphatidic acid induces reactive oxygen species generation by activating protein kinase C in PC-3 human prostate cancer cells

    Lin, Chu-Cheng; Lin, Chuan-En; Lin, Yueh-Chien [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Ju, Tsai-Kai [Instrumentation Center, National Taiwan University, Taipei, Taiwan, ROC (China); Technology Commons, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Huang, Yuan-Li [Department of Biotechnology, Asia University, Taichung, Taiwan, ROC (China); Lee, Ming-Shyue [Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC (China); Chen, Jiun-Hong [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Lee, Hsinyu, E-mail: hsinyu@ntu.edu.tw [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Center for Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan, ROC (China)

    2013-11-01

    Highlights: •LPA induces ROS generation through LPA{sub 1} and LPA{sub 3}. •LPA induces ROS generation by activating PLC. •PKCζ mediates LPA-induced ROS generation. -- Abstract: Prostate cancer is one of the most frequently diagnosed cancers in males, and PC-3 is a cell model popularly used for investigating the behavior of late stage prostate cancer. Lysophosphatidic acid (LPA) is a lysophospholipid that mediates multiple behaviors in cancer cells, such as proliferation, migration and adhesion. We have previously demonstrated that LPA enhances vascular endothelial growth factor (VEGF)-C expression in PC-3 cells by activating the generation of reactive oxygen species (ROS), which is known to be an important mediator in cancer progression. Using flow cytometry, we showed that LPA triggers ROS generation within 10 min and that the generated ROS can be suppressed by pretreatment with the NADPH oxidase (Nox) inhibitor diphenylene iodonium. In addition, transfection with LPA{sub 1} and LPA{sub 3} siRNA efficiently blocked LPA-induced ROS production, suggesting that both receptors are involved in this pathway. Using specific inhibitors and siRNA, phospholipase C (PLC) and protein kinase C (PKC) were also suggested to participate in LPA-induced ROS generation. Overall, we demonstrated that LPA induces ROS generation in PC-3 prostate cancer cells and this is mediated through the PLC/PKC/Nox pathway.

  17. Lysophosphatidic acid induces reactive oxygen species generation by activating protein kinase C in PC-3 human prostate cancer cells

    Highlights: •LPA induces ROS generation through LPA1 and LPA3. •LPA induces ROS generation by activating PLC. •PKCζ mediates LPA-induced ROS generation. -- Abstract: Prostate cancer is one of the most frequently diagnosed cancers in males, and PC-3 is a cell model popularly used for investigating the behavior of late stage prostate cancer. Lysophosphatidic acid (LPA) is a lysophospholipid that mediates multiple behaviors in cancer cells, such as proliferation, migration and adhesion. We have previously demonstrated that LPA enhances vascular endothelial growth factor (VEGF)-C expression in PC-3 cells by activating the generation of reactive oxygen species (ROS), which is known to be an important mediator in cancer progression. Using flow cytometry, we showed that LPA triggers ROS generation within 10 min and that the generated ROS can be suppressed by pretreatment with the NADPH oxidase (Nox) inhibitor diphenylene iodonium. In addition, transfection with LPA1 and LPA3 siRNA efficiently blocked LPA-induced ROS production, suggesting that both receptors are involved in this pathway. Using specific inhibitors and siRNA, phospholipase C (PLC) and protein kinase C (PKC) were also suggested to participate in LPA-induced ROS generation. Overall, we demonstrated that LPA induces ROS generation in PC-3 prostate cancer cells and this is mediated through the PLC/PKC/Nox pathway

  18. Involvement of aberrant DNA methylation on reduced expression of lysophosphatidic acid receptor-1 gene in rat tumor cell lines

    Lysophosphatidic acid (LPA) is a bioactive phospholipid that stimulates cell proliferation, migration, and protects cells from apoptosis. It interacts with specific G protein-coupled transmembrane receptors. Recently, it has been reported that alterations of LPA receptor expression might be important in the malignant transformation of tumor cells. Therefore, to assess an involvement of DNA methylation in reduced expression of the LPA receptor-1 (lpa1) gene, we investigated the expression of the lpa1 gene and its DNA methylation patterns in rat tumor cell lines. Both rat brain-derived neuroblastoma B103 and liver-derived hepatoma RH7777 cells used in this study indicated no expression of lpa1. For the analysis of methylation status, bisulfite sequencing was performed with B103 and RH7777 cells, comparing with other lpa1 expressed cells and normal tissues of brain and liver. The lpa1 expressed cells and tissues were all unmethylated in this region of lpa1. In contrast, both B103 and RH7777 cells were highly methylated, correlating with reduced expression of the lpa1. Treatment with 5-aza 2'-deoxycytidine induced expression of lpa1 gene in B103 and RH7777 cells after 24 h. In RH7777 cells treated with 5-aza 2'-deoxycytidine, stress fiber formation was also observed in response to LPA in RH7777 cells, but not in untreated RH7777 cells. These results suggest that aberrant DNA methylation of the lpa1 gene may be involved in its reduced expression in rat tumor cells

  19. Lysophosphatidic acid receptor 1 antagonist ki16425 blunts abdominal and systemic inflammation in a mouse model of peritoneal sepsis.

    Zhao, Jing; Wei, Jianxin; Weathington, Nathaniel; Jacko, Anastasia M; Huang, Hai; Tsung, Allan; Zhao, Yutong

    2015-07-01

    Lysophosphatidic acid (LPA) is a bioactive lipid mediator of inflammation via the LPA receptors 1-6. We and others have previously described proinflammatory and profibrotic activities of LPA signaling in bleomycin- or lipopolysaccharide (LPS)-induced pulmonary fibrosis or lung injury models. In this study, we investigated if LPA signaling plays a role in the pathogenesis of systemic sepsis from an abdominal source. We report here that antagonism of the LPA receptor LPA1 with the small molecule ki16425 reduces the severity of abdominal inflammation and organ damage in the setting of peritoneal endotoxin exposure. Pretreatment of mice with intraperitoneal ki16425 eliminates LPS-induced peritoneal neutrophil chemokine and cytokine production, liver oxidative stress, liver injury, and cellular apoptosis in visceral organs. Mice pretreated with ki16425 are also protected from LPS-induced mortality. Tissue myeloperoxidase activity is not affected by LPA1 antagonism. We have shown that LPA1 is associated with LPS coreceptor CD14 and the association is suppressed by ki16425. LPS-induced phosphorylation of protein kinase C δ (PKCδ) and p38 mitogen-activated protein kinase (p38 MAPK) in liver cells and interleukin 6 production in Raw264 cells are likewise blunted by LPA1 antagonism. These studies indicate that the small molecule inhibitor of LPA1, ki16425, suppresses cytokine responses and inflammation in a peritoneal sepsis model by blunting downstream signaling through the LPA1-CD14-toll-like receptor 4 receptor complex. This anti-inflammatory effect may represent a therapeutic strategy for the treatment of systemic inflammatory responses to infection of the abdominal cavity. PMID:25701366

  20. Progesterone produces antinociceptive and neuroprotective effects in rats with microinjected lysophosphatidic acid in the trigeminal nerve root

    Kim Min

    2012-03-01

    Full Text Available Abstract Background In our present study, we studied the role of demyelination of the trigeminal nerve root in the development of prolonged nociceptive behavior in the trigeminal territory. Results Under anesthesia, the Sprague-Dawley rats were mounted onto a stereotaxic frame and 3 μL of lysophosphatidic acid (LPA, 1 nmol was injected into the trigeminal nerve root to produce demyelination. This treatment decreased the air-puff thresholds, persisted until postoperative day 130, and then returned to the preoperative levels 160 days after LPA injection. The LPA-treated rats also showed a significant hyper-responsiveness to pin-prick stimulation. We further investigated the antinociceptive and neuroprotective effects of progesterone in rats undergoing demyelination of the trigeminal nerve root. Progesterone (8, 16 mg/kg/day was administered subcutaneously, beginning on the operative day, for five consecutive days in the LPA-treated rats. Treatment with progesterone produced significant early anti-allodynic effects and delayed prolonged anti-allodynic effects. The expression of protein zero (P0 and peripheral myelin protein 22 (PMP22 were significantly down-regulated in the trigeminal nerve root on postoperative day 5 following LPA injection. This down-regulation of the P0 and PMP22 levels was blocked by progesterone treatment. Conclusions These results suggest that progesterone produces antinociceptive effects through neuroprotective action in animals with LPA-induced trigeminal neuropathic pain. Moreover, progesterone has potential utility as a novel therapy for trigeminal neuropathic pain relief at an appropriate managed dose and is therefore a possible future treatment strategy for improving the recovery from injury.

  1. Derivatives of Dictyostelium differentiation-inducing factors inhibit lysophosphatidic acid-stimulated migration of murine osteosarcoma LM8 cells.

    Kubohara, Yuzuru; Komachi, Mayumi; Homma, Yoshimi; Kikuchi, Haruhisa; Oshima, Yoshiteru

    2015-08-01

    Osteosarcoma is a common metastatic bone cancer that predominantly develops in children and adolescents. Metastatic osteosarcoma remains associated with a poor prognosis; therefore, more effective anti-metastatic drugs are needed. Differentiation-inducing factor-1 (DIF-1), -2, and -3 are novel lead anti-tumor agents that were originally isolated from the cellular slime mold Dictyostelium discoideum. Here we investigated the effects of a panel of DIF derivatives on lysophosphatidic acid (LPA)-induced migration of mouse osteosarcoma LM8 cells by using a Boyden chamber assay. Some DIF derivatives such as Br-DIF-1, DIF-3(+2), and Bu-DIF-3 (5-20 μM) dose-dependently suppressed LPA-induced cell migration with associated IC50 values of 5.5, 4.6, and 4.2 μM, respectively. On the other hand, the IC50 values of Br-DIF-1, DIF-3(+2), and Bu-DIF-3 versus cell proliferation were 18.5, 7.2, and 2.0 μM, respectively, in LM8 cells, and >20, 14.8, and 4.3 μM, respectively, in mouse 3T3-L1 fibroblasts (non-transformed). Together, our results demonstrate that Br-DIF-1 in particular may be a valuable tool for the analysis of cancer cell migration, and that DIF derivatives such as DIF-3(+2) and Bu-DIF-3 are promising lead anti-tumor agents for the development of therapies that suppress osteosarcoma cell proliferation, migration, and metastasis. PMID:26056940

  2. The mouse lp(A3)/Edg7 lysophosphatidic acid receptor gene: genomic structure, chromosomal localization, and expression pattern.

    Contos, J J; Chun, J

    2001-04-18

    The extracellular signaling molecule, lysophosphatidic acid (LPA), mediates proliferative and morphological effects on cells and has been proposed to be involved in several biological processes including neuronal development, wound healing, and cancer progression. Three mammalian G protein-coupled receptors, encoded by genes designated lp (lysophospholipid) receptor or edg (endothelial differentiation gene), mediate the effects of LPA, activating similar (e.g. Ca(2+) release) as well as distinct (neurite retraction) responses. To understand the evolution and function of LPA receptor genes, we characterized lp(A3)/Edg7 in mouse and human and compared the expression pattern with the other two known LPA receptor genes (lp(A1)/Edg2 and lp(A2)/Edg4non-mutant). We found mouse and human lp(A3) to have nearly identical three-exon genomic structures, with introns upstream of the coding region for transmembrane domain (TMD) I and within the coding region for TMD VI. This structure is similar to lp(A1) and lp(A2), indicating a common ancestral gene with two introns. We localized mouse lp(A3) to distal Chromosome 3 near the varitint waddler (Va) gene, in a region syntenic with the human lp(A3) chromosomal location (1p22.3-31.1). We found highest expression levels of each of the three LPA receptor genes in adult mouse testes, relatively high expression levels of lp(A2) and lp(A3) in kidney, and moderate expression of lp(A2) and lp(A3) in lung. All lp(A) transcripts were expressed during brain development, with lp(A1) and lp(A2) transcripts expressed during the embryonic neurogenic period, and lp(A3) transcript during the early postnatal period. Our results indicate both overlapping as well as distinct functions of lp(A1), lp(A2), and lp(A3). PMID:11313151

  3. Autotaxin and lysophosphatidic acid1 receptor-mediated demyelination of dorsal root fibers by sciatic nerve injury and intrathecal lysophosphatidylcholine

    Aoki Junken

    2010-11-01

    Full Text Available Abstract Background Although neuropathic pain is frequently observed in demyelinating diseases such as Guillain-Barré syndrome and multiple sclerosis, the molecular basis for the relationship between demyelination and neuropathic pain behaviors is poorly understood. Previously, we found that lysophosphatidic acid receptor (LPA1 signaling initiates sciatic nerve injury-induced neuropathic pain and demyelination. Results In the present study, we have demonstrated that sciatic nerve injury induces marked demyelination accompanied by myelin-associated glycoprotein (MAG down-regulation and damage of Schwann cell partitioning of C-fiber-containing Remak bundles in the sciatic nerve and dorsal root, but not in the spinal nerve. Demyelination, MAG down-regulation and Remak bundle damage in the dorsal root were abolished in LPA1 receptor-deficient (Lpar1-/- mice, but these alterations were not observed in sciatic nerve. However, LPA-induced demyelination in ex vivo experiments was observed in the sciatic nerve, spinal nerve and dorsal root, all which express LPA1 transcript and protein. Nerve injury-induced dorsal root demyelination was markedly attenuated in mice heterozygous for autotaxin (atx+/-, which converts lysophosphatidylcholine (LPC to LPA. Although the addition of LPC to ex vivo cultures of dorsal root fibers in the presence of recombinant ATX caused potent demyelination, it had no significant effect in the absence of ATX. On the other hand, intrathecal injection of LPC caused potent dorsal root demyelination, which was markedly attenuated or abolished in atx+/- or Lpar1-/- mice. Conclusions These results suggest that LPA, which is converted from LPC by ATX, activates LPA1 receptors and induces dorsal root demyelination following nerve injury, which causes neuropathic pain.

  4. Lysophosphatidic acid induced nuclear translocation of nuclear factor-κB in Panc-1 cells by mobilizing cytosolic free calcium

    Yoshiyuki Arita; Tetsuhide Ito; Takamasa Pond; Ken Kawabe; Terumasa Hisano; Ryoichi Takayanagi

    2008-01-01

    AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer.METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout the study. The expression of LPA receptors was confirmed by reverse-transcript polymerase chain reaction (RT-PCR). Cytosolic free calcium was measured by fluorescent calcium indicator fura-2, and the localization of NF-κB was visualized by immunofluorescent method with or without various agents, which effect cell signaling.RESULTS: Panc-1 expressed LPA receptors, LPAA1,LPA2 and LPA3. LPA caused the elevation of cytosolic free calcium dose-dependently. LPA also caused the nuclear translocation of NF-κB. Cytosolic free calcium was attenuated by pertussis toxin (PTX) and U73122,an inhibitor of phospholipase C. The translocation of NF-κB was similarly attenuated by PTX and U73122,but phorbol ester, an activator of protein kinase C,alone did not translocate NF-κB. Furthermore, the transtocation of NF-κB was completely blocked by Ca2+ chelator BAPTA-AM. Thapsigargin, an endoplasmic-reticulum Ca2+-ATPase pump inhibitor, also promoted the translocation of NF-κB. Staurosporine, a protein kinase C inhibitor, attenuated translocation of NF-κB induced by LPA.CONCLUSlON: These findings suggest that protein kinase C is activated endogenously in Panc-1, and protein kinase C is essential for activating NF-κB with cytosolic calcium and that LPA induces the nuclear translocation of NF-κB in Panc-1 by mobilizing cytosolic free calcium.

  5. Heart-type fatty-acid-binding protein (FABP3) is a lysophosphatidic acid-binding protein in human coronary artery endothelial cells

    Tsukahara, Ryoko; Haniu, Hisao; Matsuda, Yoshikazu; Tsukahara, Tamotsu

    2014-01-01

    Fatty-acid-binding protein 3, muscle and heart (FABP3), also known as heart-type FABP, is a member of the family of intracellular lipid-binding proteins. It is a small cytoplasmic protein with a molecular mass of about 15 kDa. FABPs are known to be carrier proteins for transporting fatty acids and other lipophilic substances from the cytoplasm to the nucleus, where these lipids are released to a group of nuclear receptors such as peroxisome proliferator-activated receptors (PPARs). In this study, using lysophosphatidic acid (LPA)-coated agarose beads, we have identified FABP3 as an LPA carrier protein in human coronary artery endothelial cells (HCAECs). Administration of LPA to HCAECs resulted in a dose-dependent increase in PPARγ activation. Furthermore, the LPA-induced PPARγ activation was abolished when the FABP3 expression was reduced using small interfering RNA (siRNA). We further show that the nuclear fraction of control HCAECs contained a significant amount of exogenously added LPA, whereas FABP3 siRNA-transfected HCAECs had a decreased level of LPA in the nucleus. Taken together, these results suggest that FABP3 governs the transcriptional activities of LPA by targeting them to cognate PPARγ in the nucleus. PMID:25426414

  6. Heart-type fatty-acid-binding protein (FABP3 is a lysophosphatidic acid-binding protein in human coronary artery endothelial cells

    Ryoko Tsukahara

    2014-01-01

    Full Text Available Fatty-acid-binding protein 3, muscle and heart (FABP3, also known as heart-type FABP, is a member of the family of intracellular lipid-binding proteins. It is a small cytoplasmic protein with a molecular mass of about 15 kDa. FABPs are known to be carrier proteins for transporting fatty acids and other lipophilic substances from the cytoplasm to the nucleus, where these lipids are released to a group of nuclear receptors such as peroxisome proliferator-activated receptors (PPARs. In this study, using lysophosphatidic acid (LPA-coated agarose beads, we have identified FABP3 as an LPA carrier protein in human coronary artery endothelial cells (HCAECs. Administration of LPA to HCAECs resulted in a dose-dependent increase in PPARγ activation. Furthermore, the LPA-induced PPARγ activation was abolished when the FABP3 expression was reduced using small interfering RNA (siRNA. We further show that the nuclear fraction of control HCAECs contained a significant amount of exogenously added LPA, whereas FABP3 siRNA-transfected HCAECs had a decreased level of LPA in the nucleus. Taken together, these results suggest that FABP3 governs the transcriptional activities of LPA by targeting them to cognate PPARγ in the nucleus.

  7. Autotaxin, a synthetic enzyme of lysophosphatidic acid (LPA, mediates the induction of nerve-injured neuropathic pain

    Chun Jerold

    2008-02-01

    Full Text Available Abstract Recently, we reported that lysophosphatidic acid (LPA induces long-lasting mechanical allodynia and thermal hyperalgesia as well as demyelination and upregulation of pain-related proteins through one of its cognate receptors, LPA1. In addition, mice lacking the LPA1 receptor gene (lpa1-/- mice lost these nerve injury-induced neuropathic pain behaviors and phenomena. However, since lpa1-/- mice did not exhibit any effects on the basal nociceptive threshold, it is possible that nerve injury-induced neuropathic pain and its machineries are initiated by LPA via defined biosynthetic pathways that involve multiple enzymes. Here, we attempted to clarify the involvement of a single synthetic enzyme of LPA known as autotaxin (ATX in nerve injury-induced neuropathic pain. Wild-type mice with partial sciatic nerve injury showed robust mechanical allodynia starting from day 3 after the nerve injury and persisting for at least 14 days, along with thermal hyperalgesia. On the other hand, heterozygous mutant mice for the autotaxin gene (atx+/-, which have 50% ATX protein and 50% lysophospholipase D activity compared with wild-type mice, showed approximately 50% recovery of nerve injury-induced neuropathic pain. In addition, hypersensitization of myelinated Aβ˜ MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGacaGaaiaabeqaaeqabiWaaaGcbaGafqOSdiMbaGaaaaa@2D83@- or Aδ-fiber function following nerve injury was observed in electrical stimuli-induced paw withdrawal tests using a Neurometer®. The hyperalgesia was completely abolished in lpa1-/- mice, and reduced by 50% in atx+/- mice. Taken together, these findings suggest that LPA biosynthesis through ATX is the source of LPA for LPA1 receptor-mediated neuropathic pain. Therefore, targeted inhibition of ATX-mediated LPA biosynthesis as well as

  8. Cancer cell expression of autotaxin controls bone metastasis formation in mouse through lysophosphatidic acid-dependent activation of osteoclasts.

    Marion David

    Full Text Available BACKGROUND: Bone metastases are highly frequent complications of breast cancers. Current bone metastasis treatments using powerful anti-resorptive agents are only palliative indicating that factors independent of bone resorption control bone metastasis progression. Autotaxin (ATX/NPP2 is a secreted protein with both oncogenic and pro-metastatic properties. Through its lysosphospholipase D (lysoPLD activity, ATX controls the level of lysophosphatidic acid (LPA in the blood. Platelet-derived LPA promotes the progression of osteolytic bone metastases of breast cancer cells. We asked whether ATX was involved in the bone metastasis process. We characterized the role of ATX in osteolytic bone metastasis formation by using genetically modified breast cancer cells exploited on different osteolytic bone metastasis mouse models. METHODOLOGY/PRINCIPAL FINDINGS: Intravenous injection of human breast cancer MDA-B02 cells with forced expression of ATX (MDA-B02/ATX to immunodeficiency BALB/C nude mice enhanced osteolytic bone metastasis formation, as judged by increased bone loss, tumor burden, and a higher number of active osteoclasts at the metastatic site. Mouse breast cancer 4T1 cells induced the formation of osteolytic bone metastases after intracardiac injection in immunocompetent BALB/C mice. These cells expressed active ATX and silencing ATX expression inhibited the extent of osteolytic bone lesions and decreased the number of active osteoclasts at the bone metastatic site. In vitro, osteoclast differentiation was enhanced in presence of MDA-B02/ATX cell conditioned media or recombinant autotaxin that was blocked by the autotaxin inhibitor vpc8a202. In vitro, addition of LPA to active charcoal-treated serum restored the capacity of the serum to support RANK-L/MCSF-induced osteoclastogenesis. CONCLUSION/SIGNIFICANCE: Expression of autotaxin by cancer cells controls osteolytic bone metastasis formation. This work demonstrates a new role for LPA as a

  9. Lysophosphatidic acid alters the expression profiles of angiogenic factors, cytokines, and chemokines in mouse liver sinusoidal endothelial cells.

    Chia-Hung Chou

    Full Text Available Lysophosphatidic acid (LPA is a multi-function glycerophospholipid. LPA affects the proliferation of hepatocytes and stellate cells in vitro, and in a partial hepatectomy induced liver regeneration model, the circulating LPA levels and LPA receptor (LPAR expression levels in liver tissue are significantly changed. Liver sinusoidal endothelial cells (Lsecs play an important role during liver regeneration. However, the effects of LPA on Lsecs are not well known. Thus, we investigated the effects of LPA on the expression profiles of angiogenic factors, cytokines, and chemokines in Lsecs.Mouse Lsecs were isolated using CD31-coated magnetic beads. The mRNA expression levels of LPAR's and other target genes were determined by quantitative RT-PCR. The protein levels of angiogenesis factors, cytokines, and chemokines were determined using protein arrays and enzyme immunoassay (EIA. Critical LPAR related signal transduction was verified by using an appropriate chemical inhibitor.LPAR1 and LPAR3 mRNA's were expressed in mouse LPA-treated Lsecs. Treating Lsecs with a physiological level of LPA significantly enhanced the protein levels of angiogenesis related proteins (cyr61 and TIMP-1, cytokines (C5/C5a, M-CSF, and SDF-1, and chemokines (MCP-5, gp130, CCL28, and CXCL16. The LPAR1 and LPAR3 antagonist ki16425 significantly inhibited the LPA-enhanced expression of cyr61, TIMP-1, SDF-1, MCP-5, gp130, CCL28, and CXCL16, but not that of C5/C5a or M-CSF. LPA-induced C5/C5a and M-CSF expression may have been through an indirect regulation mechanism.LPA regulated the expression profiles of angiogenic factors, cytokines, and chemokines in Lsecs that was mediated via LPAR1 and LPAR3 signaling. Most of the factors that were enhanced by LPA have been found to play critical roles during liver regeneration. Thus, these results may prove useful for manipulating LPA effects on liver regeneration.

  10. Lysophosphatidic Acid Alters the Expression Profiles of Angiogenic Factors, Cytokines, and Chemokines in Mouse Liver Sinusoidal Endothelial Cells

    Chou, Chia-Hung; Lai, Shou-Lun; Ho, Cheng-Maw; Lin, Wen-Hsi; Chen, Chiung-Nien; Lee, Po-Huang; Peng, Fu-Chuo; Kuo, Sung-Hsin; Wu, Szu-Yuan; Lai, Hong-Shiee

    2015-01-01

    Background and Aims Lysophosphatidic acid (LPA) is a multi-function glycerophospholipid. LPA affects the proliferation of hepatocytes and stellate cells in vitro, and in a partial hepatectomy induced liver regeneration model, the circulating LPA levels and LPA receptor (LPAR) expression levels in liver tissue are significantly changed. Liver sinusoidal endothelial cells (Lsecs) play an important role during liver regeneration. However, the effects of LPA on Lsecs are not well known. Thus, we investigated the effects of LPA on the expression profiles of angiogenic factors, cytokines, and chemokines in Lsecs. Methods Mouse Lsecs were isolated using CD31-coated magnetic beads. The mRNA expression levels of LPAR’s and other target genes were determined by quantitative RT-PCR. The protein levels of angiogenesis factors, cytokines, and chemokines were determined using protein arrays and enzyme immunoassay (EIA). Critical LPAR related signal transduction was verified by using an appropriate chemical inhibitor. Results LPAR1 and LPAR3 mRNA’s were expressed in mouse LPA-treated Lsecs. Treating Lsecs with a physiological level of LPA significantly enhanced the protein levels of angiogenesis related proteins (cyr61 and TIMP-1), cytokines (C5/C5a, M-CSF, and SDF-1), and chemokines (MCP-5, gp130, CCL28, and CXCL16). The LPAR1 and LPAR3 antagonist ki16425 significantly inhibited the LPA-enhanced expression of cyr61, TIMP-1, SDF-1, MCP-5, gp130, CCL28, and CXCL16, but not that of C5/C5a or M-CSF. LPA-induced C5/C5a and M-CSF expression may have been through an indirect regulation mechanism. Conclusion LPA regulated the expression profiles of angiogenic factors, cytokines, and chemokines in Lsecs that was mediated via LPAR1 and LPAR3 signaling. Most of the factors that were enhanced by LPA have been found to play critical roles during liver regeneration. Thus, these results may prove useful for manipulating LPA effects on liver regeneration. PMID:25822713

  11. Identification of Heparin-Binding EGF-Like Growth Factor (HB-EGF) as a Biomarker for Lysophosphatidic Acid Receptor Type 1 (LPA1) Activation in Human Breast and Prostate Cancers

    David, Marion; Sahay, Debashish; Mege, Florence; Descotes, Françoise; Leblanc, Raphaël; Ribeiro, Johnny; Clézardin, Philippe; Peyruchaud, Olivier

    2014-01-01

    Lysophosphatidic acid (LPA) is a natural bioactive lipid with growth factor-like functions due to activation of a series of six G protein-coupled receptors (LPA1–6). LPA receptor type 1 (LPA1) signaling influences the pathophysiology of many diseases including cancer, obesity, rheumatoid arthritis, as well as lung, liver and kidney fibrosis. Therefore, LPA1 is an attractive therapeutic target. However, most mammalian cells co-express multiple LPA receptors whose co-activation impairs the vali...

  12. Quantitative Phosphoproteome Analysis of Lysophosphatidic Acid Induced Chemotaxis applying Dual-step ¹⁸O Labeling Coupled with Immobilized Metal-ion Affinity Chromatography

    Ding, Shi-Jian; Wang, Yingchun; Jacobs, Jon M.; Qian, Weijun; Yang, Feng; Tolmachev, Aleksey V.; Du, Xiuxia; Wang, Wei; Moore, Ronald J.; Monroe, Matthew E.; Purvine, Samuel O.; Waters, Katrina M.; Heibeck, Tyler H.; Adkins, Joshua N.; Camp, David G.; Klemke, Richard L.; Smith, Richard D.

    2008-10-01

    Reversible protein phosphorylation is a central cellular regulatory mechanism in modulating protein activity and propagating signals within cellular pathways and networks. Development of more effective methods for the simultaneous identification of phosphorylation sites and quantification of temporal changes in protein phosphorylation could provide important insights into molecular signaling mechanisms in a variety of different cellular processes. Here we present an integrated quantitative phosphoproteomics approach and its applications for comparative analysis of Cos-7 cells in response to lysophosphatidic acid (LPA) gradient stimulation. The approach combines trypsin-catalyzed 16O/18O labeling plus 16O/18O-methanol esterification labeling for quantitation, a macro- Immobilized Metal-ion Affinity Chromatography trap for phosphopeptide enrichment, and a monolithic capillary column with integrated electrospray emitter. LC separation and MS/MS is followed by neutral loss-dependent MS/MS/MS for phosphopeptide identification using a linear ion trap (LTQ)-FT mass spectrometer and complementary searching algorithms for interpreting MS/MS spectra. Protein phosphorylation involved in various signaling pathways of cell migration were identified and quantified, such as mitogen-activated protein kinase 1, dual-specificity mitogen-activated protein kinase kinase 2, and dual-specificity tyrosine-phosphorylation regulated kinase 1b, and a number of Rho GTPase-activating proteins. These results demonstrate the efficiency of this quantitative phosphoproteomics approach and its application for rapid discovery of phosphorylation events associated with gradient sensing and cell chemotaxis.

  13. Expression of lysophosphatidic acid receptor 1 and relation with cell proliferation, apoptosis, and angiogenesis on preneoplastic changes induced by cadmium chloride in the rat ventral prostate.

    Riánsares Arriazu

    Full Text Available BACKGROUND: Lysophosphatidic acid (LPA is a phospholipid growth factor involved in cell proliferation, differentiation, migration, inflammation, angiogenesis, wound healing, cancer invasion, and survival. This study was directed to evaluate the immunoexpression of LPA-1, cell proliferation, apoptosis, and angiogenesis markers in preneoplastic lesions induced with cadmium chloride in rat prostate. METHODS: The following parameters were calculated in ventral prostate of normal rats and rats that received Cd in drinking water during 24 months: percentages of cells immunoreactive to LPA-1 (LILPA1, PCNA (LIPCNA, MCM7 (LIMCM7, ubiquitin (LIUBI, apoptotic cells (LIAPO, and p53 (LIp53; volume fraction of Bcl-2 (VFBcl-2; and length of microvessels per unit of volume (LVMV/mm3. Data were analyzed using Student's t-test and Pearson correlation test. RESULTS: The LILPA1 in dysplastic lesions and normal epithelium of Cd-treated rats was significantly higher than those in the control group. Markers of proliferation were significantly increased in dysplastic lesions, whereas some apoptotic markers were significantly decreased. No significant differences between groups were found in VFBcl-2. Dysplastic lesions showed a significant increase of LIp53. The length of microvessels per unit of volume was elevated in dysplastic acini. Statistically significant correlations were found only between LILPA1 and LIUBI. CONCLUSIONS: Our results suggest that LPA-1 might be implicated in dysplastic lesions induced by cadmium chloride development. More studies are needed to confirm its potential contribution to the disease.

  14. Mechanism of sphingosine 1-phosphate- and lysophosphatidic Acid-induced up-regulation of adhesion molecules and eosinophil chemoattractant in nerve cells.

    Costello, Richard W

    2012-02-01

    The lysophospholipids sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) act via G-protein coupled receptors S1P(1-5) and LPA(1-3) respectively, and are implicated in allergy. Eosinophils accumulate at innervating cholinergic nerves in asthma and adhere to nerve cells via intercellular adhesion molecule-1 (ICAM-1). IMR-32 neuroblastoma cells were used as an in vitro cholinergic nerve cell model. The G(i) coupled receptors S1P(1), S1P(3), LPA(1), LPA(2) and LPA(3) were expressed on IMR-32 cells. Both S1P and LPA induced ERK phosphorylation and ERK- and G(i)-dependent up-regulation of ICAM-1 expression, with differing time courses. LPA also induced ERK- and G(i)-dependent up-regulation of the eosinophil chemoattractant, CCL-26. The eosinophil granule protein eosinophil peroxidase (EPO) induced ERK-dependent up-regulation of transcription of S1P(1), LPA(1), LPA(2) and LPA(3), providing the situation whereby eosinophil granule proteins may enhance S1P- and\\/or LPA- induced eosinophil accumulation at nerve cells in allergic conditions.

  15. Mechanism of sphingosine 1-phosphate- and lysophosphatidic Acid-induced up-regulation of adhesion molecules and eosinophil chemoattractant in nerve cells.

    Costello, Richard W

    2011-05-01

    The lysophospholipids sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) act via G-protein coupled receptors S1P(1-5) and LPA(1-3) respectively, and are implicated in allergy. Eosinophils accumulate at innervating cholinergic nerves in asthma and adhere to nerve cells via intercellular adhesion molecule-1 (ICAM-1). IMR-32 neuroblastoma cells were used as an in vitro cholinergic nerve cell model. The G(i) coupled receptors S1P(1), S1P(3), LPA(1), LPA(2) and LPA(3) were expressed on IMR-32 cells. Both S1P and LPA induced ERK phosphorylation and ERK- and G(i)-dependent up-regulation of ICAM-1 expression, with differing time courses. LPA also induced ERK- and G(i)-dependent up-regulation of the eosinophil chemoattractant, CCL-26. The eosinophil granule protein eosinophil peroxidase (EPO) induced ERK-dependent up-regulation of transcription of S1P(1), LPA(1), LPA(2) and LPA(3), providing the situation whereby eosinophil granule proteins may enhance S1P- and\\/or LPA- induced eosinophil accumulation at nerve cells in allergic conditions.

  16. Aromatic hydrocarbon receptor inhibits lysophosphatidic acid-induced vascular endothelial growth factor-A expression in PC-3 prostate cancer cells

    Wu, Pei-Yi; Lin, Yueh-Chien; Lan, Shun-Yan [Institute of Zoology, National Taiwan University, Taipei, Taiwan (China); Huang, Yuan-Li [Department of Biotechnology, Asia University, Taichung, Taiwan (China); Lee, Hsinyu, E-mail: hsinyu@ntu.edu.tw [Institute of Zoology, National Taiwan University, Taipei, Taiwan (China); Department of Life Science, National Taiwan University, Taipei, Taiwan (China)

    2013-08-02

    Highlights: •LPA-induced VEGF-A expression was regulated by HIF-1α and ARNT. •PI3K mediated LPA-induced VEGF-A expression. •AHR signaling inhibited LPA-induced VEGF-A expression in PC-3 cells. -- Abstract: Lysophosphatidic acid (LPA) is a lipid growth factor with multiple biological functions and has been shown to stimulate cancer cell secretion of vascular endothelial growth factor-A (VEGF-A) and trigger angiogenesis. Hypoxia-inducible factor-1 (HIF-1), a heterodimer consisting of HIF-1α and HIF-1β (also known as aromatic hydrocarbon receptor nuclear translocator (ARNT)) subunits, is an important regulator of angiogenesis in prostate cancer (PC) through the enhancement of VEGF-A expression. In this study, we first confirmed the ability of LPA to induce VEGF-A expression in PC-3 cells and then validated that LPA-induced VEGF-A expression was regulated by HIF-1α and ARNT through phosphatidylinositol 3-kinase activation. Aromatic hydrocarbon receptor (AHR), a receptor for dioxin-like compounds, functions as a transcription factor through dimerization with ARNT and was found to inhibit prostate carcinogenesis and vanadate-induced VEGF-A production. Since ARNT is a common dimerization partner of AHR and HIF-1α, we hypothesized that AHR might suppress LPA-induced VEGF-A expression in PC-3 cells by competing with HIF-1α for ARNT. Here we demonstrated that overexpression and ligand activation of AHR inhibited HIF-1-mediated VEGF-A induction by LPA treatment of PC-3 cells. In conclusion, our results suggested that AHR activation may inhibit LPA-induced VEGF-A expression in PC-3 cells by attenuating HIF-1α signaling, and subsequently, suppressing angiogenesis and metastasis of PC. These results suggested that AHR presents a potential therapeutic target for the prevention of PC metastasis.

  17. β-Arrestin2 regulates lysophosphatidic acid-induced human breast tumor cell migration and invasion via Rap1 and IQGAP1.

    Mistre Alemayehu

    Full Text Available β-Arrestins play critical roles in chemotaxis and cytoskeletal reorganization downstream of several receptor types, including G protein-coupled receptors (GPCRs, which are targets for greater than 50% of all pharmaceuticals. Among them, receptors for lysophosphatidic acid (LPA, namely LPA(1 are overexpressed in breast cancer and promote metastatic spread. We have recently reported that β-arrestin2 regulates LPA(1-mediated breast cancer cell migration and invasion, although the underlying molecular mechanisms are not clearly understood. We show here that LPA induces activity of the small G protein, Rap1 in breast cancer cells in a β-arrestin2-dependent manner, but fails to activate Rap1 in non-malignant mammary epithelial cells. We found that Rap1A mRNA levels are higher in human breast tumors compared to healthy patient samples and Rap1A is robustly expressed in human ductal carcinoma in situ and invasive tumors, in contrast to the normal mammary ducts. Rap1A protein expression is also higher in aggressive breast cancer cells (MDA-MB-231 and Hs578t relative to the weakly invasive MCF-7 cells or non-malignant MCF10A mammary cells. Depletion of Rap1A expression significantly impaired LPA-stimulated migration of breast cancer cells and invasiveness in three-dimensional Matrigel cultures. Furthermore, we found that β-arrestin2 associates with the actin binding protein IQGAP1 in breast cancer cells, and is necessary for the recruitment of IQGAP1 to the leading edge of migratory cells. Depletion of IQGAP1 blocked LPA-stimulated breast cancer cell invasion. Finally, we have identified that LPA enhances the binding of endogenous Rap1A to β-arrestin2, and also stimulates Rap1A and IQGAP1 to associate with LPA(1. Thus our data establish novel roles for Rap1A and IQGAP1 as critical regulators of LPA-induced breast cancer cell migration and invasion.

  18. Regulation of gene expression and subcellular protein distribution in MLO-Y4 osteocytic cells by lysophosphatidic acid: Relevance to dendrite outgrowth.

    Waters, Katrina M.; Jacobs, Jon M.; Gritsenko, Marina A.; Karin, Norman J.

    2011-02-26

    Osteoblastic and osteocytic cells are highly responsive to the lipid growth factor lysophosphatidic acid (LPA) but the mechanisms by which LPA alters bone cell functions are largely unknown. A major effect of LPA on osteocytic cells is the stimulation of dendrite membrane outgrowth, a process that we predicted to require changes in gene expression and protein distribution. We employed DNA microarrays for global transcriptional profiling of MLO-Y4 osteocytic cells grown for 6 and 24h in the presence or absence of LPA. We identified 932 transcripts that displayed statistically significant changes in abundance of at least 1.25-fold in response to LPA treatment. Gene ontology (GO) analysis revealed that the regulated gene products were linked to diverse cellular processes, including DNA repair, response to unfolded protein, ossification, protein-RNA complex assembly, and amine biosynthesis. Gene products associated with the regulation of actin microfilament dynamics displayed the most robust expression changes, and LPA-induced dendritogenesis in vitro was blocked by the stress fiber inhibitor cytochalasin D. Mass spectrometry-based proteomic analysis of MLO-Y4 cells revealed significant LPA-induced changes in the abundance of 284 proteins at 6h and 844 proteins at 24h. GO analysis of the proteomic data linked the effects of LPA to cell processes that control of protein distribution and membrane outgrowth, including protein localization, protein complex assembly, Golgi vesicle transport, cytoskeleton-dependent transport, and membrane invagination/endocytosis. Dendrites were isolated from LPA-treated MLO-Y4 cells and subjected to proteomic analysis to quantitatively assess the subcellular distribution of proteins. Sets of 129 and 36 proteins were enriched in the dendrite fraction as compared to whole cells after 6h and 24h of LPA exposure, respectively. Protein markers indicated that membranous organelles were largely excluded from the dendrites. Highly represented among

  19. 偏头痛急性期患者溶血磷脂酸与TCD的变化%Changes of lysophosphatidic acid and TCD in patients with migraine during acute stage

    宋叶华; 牛建平; 汤婷; 叶良灶; 何倪靖

    2013-01-01

    Objective Observation the changesof plasma lysophosphatidic acid (LPA) 、lysophosphatidic acid similar levels of phospholipids(AP) and Transcranial Doppler ultrasound (TCD) in acute migraine patients. Methodes Determination plasma LPA and AP in migraine patients with acute period (migraine without aura and migraine with aura group) ,at the same time,were examined by TCD, compared with normal patients. Results Migraine patients with LPA 、AP increased significantly, especial y for migraine with aura group increased more significantly, suggesting that platelet activation in patients with acute migraine attacks, and blood flow velocity in patients with migraine acute stage significantly increased in patients with migraine.The results support functions - vascular nerve disorder in patients with migraine.%目的观察偏头痛急性发作期患者血浆溶血磷脂酸(LPA)及溶血磷脂酸相似磷脂水平(AP)、经颅多普勒超声(TCD)的变化。方法测定偏头痛急性期患者(无先兆偏头痛组及有先兆偏头痛组)血浆LPA及AP水平,同时对患者行TCD检查,与正常患者进行对照。结果偏头痛组血浆LPA水平高于对照组,尤其是有先兆偏头痛组,且偏头痛急性期TCD以血流速度增快为主,尤其是患侧大脑中动脉血流速度。结论偏头痛发作期患者LPA、AP明显升高,尤其是有先兆偏头痛组升高更明显,提示偏头痛急性发作期患者存在血小板活化过程,同时偏头痛急性期患者血流速度常明显增快,支持偏头痛患者存在神经-血管功能紊乱。

  20. Apicoplast-Localized Lysophosphatidic Acid Precursor Assembly Is Required for Bulk Phospholipid Synthesis in Toxoplasma gondii and Relies on an Algal/Plant-Like Glycerol 3-Phosphate Acyltransferase.

    Amiar, Souad; MacRae, James I; Callahan, Damien L; Dubois, David; van Dooren, Giel G; Shears, Melanie J; Cesbron-Delauw, Marie-France; Maréchal, Eric; McConville, Malcolm J; McFadden, Geoffrey I; Yamaryo-Botté, Yoshiki; Botté, Cyrille Y

    2016-08-01

    Most apicomplexan parasites possess a non-photosynthetic plastid (the apicoplast), which harbors enzymes for a number of metabolic pathways, including a prokaryotic type II fatty acid synthesis (FASII) pathway. In Toxoplasma gondii, the causative agent of toxoplasmosis, the FASII pathway is essential for parasite growth and infectivity. However, little is known about the fate of fatty acids synthesized by FASII. In this study, we have investigated the function of a plant-like glycerol 3-phosphate acyltransferase (TgATS1) that localizes to the T. gondii apicoplast. Knock-down of TgATS1 resulted in significantly reduced incorporation of FASII-synthesized fatty acids into phosphatidic acid and downstream phospholipids and a severe defect in intracellular parasite replication and survival. Lipidomic analysis demonstrated that lipid precursors are made in, and exported from, the apicoplast for de novo biosynthesis of bulk phospholipids. This study reveals that the apicoplast-located FASII and ATS1, which are primarily used to generate plastid galactolipids in plants and algae, instead generate bulk phospholipids for membrane biogenesis in T. gondii. PMID:27490259

  1. Identification of heparin-binding EGF-like growth factor (HB-EGF as a biomarker for lysophosphatidic acid receptor type 1 (LPA1 activation in human breast and prostate cancers.

    Marion David

    Full Text Available Lysophosphatidic acid (LPA is a natural bioactive lipid with growth factor-like functions due to activation of a series of six G protein-coupled receptors (LPA₁₋₆. LPA receptor type 1 (LPA₁ signaling influences the pathophysiology of many diseases including cancer, obesity, rheumatoid arthritis, as well as lung, liver and kidney fibrosis. Therefore, LPA₁ is an attractive therapeutic target. However, most mammalian cells co-express multiple LPA receptors whose co-activation impairs the validation of target inhibition in patients because of missing LPA receptor-specific biomarkers. LPA₁ is known to induce IL-6 and IL-8 secretion, as also do LPA₂ and LPA₃. In this work, we first determined the LPA induced early-gene expression profile in three unrelated human cancer cell lines expressing different patterns of LPA receptors (PC3: LPA₁,₂,₆; MDA-MB-231: LPA1,2; MCF-7: LPA₂,₆. Among the set of genes upregulated by LPA only in LPA₁-expressing cells, we validated by QPCR and ELISA that upregulation of heparin-binding EGF-like growth factor (HB-EGF was inhibited by LPA₁-₃ antagonists (Ki16425, Debio0719. Upregulation and downregulation of HB-EGF mRNA was confirmed in vitro in human MDA-B02 breast cancer cells stably overexpressing LPA₁ (MDA-B02/LPA₁ and downregulated for LPA₁ (MDA-B02/shLPA1, respectively. At a clinical level, we quantified the expression of LPA₁ and HB-EGF by QPCR in primary tumors of a cohort of 234 breast cancer patients and found a significantly higher expression of HB-EGF in breast tumors expressing high levels of LPA₁. We also generated human xenograph prostate tumors in mice injected with PC3 cells and found that a five-day treatment with Ki16425 significantly decreased both HB-EGF mRNA expression at the primary tumor site and circulating human HB-EGF concentrations in serum. All together our results demonstrate that HB-EGF is a new and relevant biomarker with potentially high value in

  2. Dual Action of Lysophosphatidate-Functionalised Titanium: Interactions with Human (MG63) Osteoblasts and Methicillin Resistant Staphylococcus aureus

    Skindersø, Mette Elena; Krogfelt, Karen Angeliki; Blom, Ashley;

    2015-01-01

    design. One way of realising improvements in implant quality is to coat the Ti surface with small biological agents known to support human osteoblast formation and maturation at Ti surfaces. Lysophosphatidic acid (LPA) and certain LPA analogues offer potential solutions as Ti coatings in reducing aseptic...

  3. Tetracyclines increase lipid phosphate phosphatase expression on plasma membranes and turnover of plasma lysophosphatidate.

    Tang, Xiaoyun; Zhao, Yuan Y; Dewald, Jay; Curtis, Jonathan M; Brindley, David N

    2016-04-01

    Extracellular lysophosphatidate and sphingosine 1-phosphate (S1P) are important bioactive lipids, which signal through G-protein-coupled receptors to stimulate cell growth and survival. The lysophosphatidate and S1P signals are terminated partly by degradation through three broad-specificity lipid phosphate phosphatases (LPPs) on the cell surface. Significantly, the expression of LPP1 and LPP3 is decreased in many cancers, and this increases the impact of lysophosphatidate and S1P signaling. However, relatively little is known about the physiological or pharmacological regulation of the expression of the different LPPs. We now show that treating several malignant and nonmalignant cell lines with 1 μg/ml tetracycline, doxycycline, or minocycline significantly increased the extracellular degradation of lysophosphatidate. S1P degradation was also increased in cells that expressed high LPP3 activity. These results depended on an increase in the stabilities of the three LPPs and increased expression on the plasma membrane. We tested the physiological significance of these results and showed that treating rats with doxycycline accelerated the clearance of lysophosphatidate, but not S1P, from the circulation. However, administering 100 mg/kg/day doxycycline to mice decreased plasma concentrations of lysophosphatidate and S1P. This study demonstrates a completely new property of tetracyclines in increasing the plasma membrane expression of the LPPs. PMID:26884614

  4. Lysophosphatidate induces chemo-resistance by releasing breast cancer cells from taxol-induced mitotic arrest.

    Nasser Samadi

    Full Text Available BACKGROUND: Taxol is a microtubule stabilizing agent that arrests cells in mitosis leading to cell death. Taxol is widely used to treat breast cancer, but resistance occurs in 25-69% of patients and it is vital to understand how Taxol resistance develops to improve chemotherapy. The effects of chemotherapeutic agents are overcome by survival signals that cancer cells receive. We focused our studies on autotaxin, which is a secreted protein that increases tumor growth, aggressiveness, angiogenesis and metastasis. We discovered that autotaxin strongly antagonizes the Taxol-induced killing of breast cancer and melanoma cells by converting the abundant extra-cellular lipid, lysophosphatidylcholine, into lysophosphatidate. This lipid stimulates specific G-protein coupled receptors that activate survival signals. METHODOLOGY/PRINCIPAL FINDINGS: In this study we determined the basis of these antagonistic actions of lysophosphatidate towards Taxol-induced G2/M arrest and cell death using cultured breast cancer cells. Lysophosphatidate does not antagonize Taxol action in MCF-7 cells by increasing Taxol metabolism or its expulsion through multi-drug resistance transporters. Lysophosphatidate does not lower the percentage of cells accumulating in G2/M by decreasing exit from S-phase or selective stimulation of cell death in G2/M. Instead, LPA had an unexpected and remarkable action in enabling MCF-7 and MDA-MB-468 cells, which had been arrested in G2/M by Taxol, to normalize spindle structure and divide, thus avoiding cell death. This action involves displacement of Taxol from the tubulin polymer fraction, which based on inhibitor studies, depends on activation of LPA receptors and phosphatidylinositol 3-kinase. CONCLUSIONS/SIGNIFICANCE: This work demonstrates a previously unknown consequence of lysophosphatidate action that explains why autotaxin and lysophosphatidate protect against Taxol-induced cell death and promote resistance to the action of this

  5. An ultra-high performance liquid chromatography-tandem mass spectrometric assay for quantifying 3-ketocholanoic acid: Application to the human liver microsomal CYP3A-dependent lithocholic acid 3-oxidation assay.

    Bansal, Sumit; Chai, Swee Fen; Lau, Aik Jiang

    2016-06-15

    Lithocholic acid (LCA), a hepatotoxic and carcinogenic bile acid, is metabolized to 3-ketocholanoic acid (3-KCA) by cytochrome P450 3A (CYP3A). In the present study, the objectives were to develop and validate an ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method to quantify 3-KCA and apply it to the human liver microsomal CYP3A-dependent LCA 3-oxidation assay. Chromatographic separation was achieved on a Waters ACQUITY™ UPLC C18 column (50×2.1mm, 1.7μm) with a gradient system consisting of 0.1% v/v formic acid in water (solvent A) and 0.1% v/v formic acid in acetonitrile (solvent B). The retention time was 3.73min for 3-KCA and 2.73min for cortisol (internal standard). Positive electrospray ionization with multiple reaction monitoring (MRM) mode was used to quantify 3-KCA (m/z 375.4→135.2) and cortisol (m/z 363.5→121.0). The limit of detection of 3-KCA was 10μM, the lower limit of quantification was 33.3μM, and the calibration curve was linear from 0.05-10μM with r(2)>0.99. Intra-day and inter-day accuracy and precision were LCA 3-oxidation assay was linear with respect to the amount of microsomal protein (up to 40μg) and incubation time (5-30min). Enzyme kinetics experiment indicated that LCA 3-oxidation followed the Michaelis-Menten model with an apparent Km of 26±7μM and Vmax of 303±50pmol/min/mg protein. This novel UPLC-MS/MS method for quantifying 3-KCA offers a specific, sensitive, and fast approach to determine liver microsomal LCA 3-oxidation. PMID:27153105

  6. Tauroursodeoxycholate Protects Rat Hepatocytes from Bile Acid-Induced Apoptosis via β1-Integrin- and Protein Kinase A-Dependent Mechanisms

    Annika Sommerfeld

    2015-05-01

    Full Text Available Background/Aims: Ursodeoxycholic acid, which in vivo is rapidly converted into its taurine conjugate, is frequently used for the treatment of cholestatic liver disease. Apart from its choleretic effects, tauroursodeoxycholate (TUDC can protect hepatocytes from bile acid-induced apoptosis, but the mechanisms underlying its anti-apoptotic effects are poorly understood. Methods: These mechanisms were investigated in perfused rat liver and isolated rat hepatocytes. Results: It was found that TUDC inhibited the glycochenodeoxycholate (GCDC-induced activation of the CD95 death receptor at the level of association between CD95 and the epidermal growth factor receptor. This was due to a rapid TUDC-induced β1-integrin-dependent cyclic AMP (cAMP signal with induction of the dual specificity mitogen-activated protein (MAP kinase phosphatase 1 (MKP-1, which prevented GCDC-induced phosphorylation of mitogen-activated protein kinase kinase 4 (MKK4 and c-jun-NH2-terminal kinase (JNK activation. Furthermore, TUDC induced a protein kinase A (PKA-mediated serine/threonine phosphorylation of the CD95, which was recently identified as an internalization signal for CD95. Furthermore, TUDC inhibited GCDC-induced CD95 targeting to the plasma membrane in a β1-integrin-and PKA-dependent manner. In line with this, the β1-integrin siRNA knockdown in sodium taurocholate cotransporting polypeptide (Ntcp-transfected HepG2 cells abolished the protective effect of TUDC against GCDC-induced apoptosis. Conclusion: TUDC exerts its anti-apoptotic effect via a β1-integrin-mediated formation of cAMP, which prevents CD95 activation by hydrophobic bile acids at the levels of JNK activation and CD95 serine/threonine phosphorylation.

  7. Derivatives of Dictyostelium differentiation-inducing factors inhibit lysophosphatidic acid–stimulated migration of murine osteosarcoma LM8 cells

    Osteosarcoma is a common metastatic bone cancer that predominantly develops in children and adolescents. Metastatic osteosarcoma remains associated with a poor prognosis; therefore, more effective anti-metastatic drugs are needed. Differentiation-inducing factor-1 (DIF-1), −2, and −3 are novel lead anti-tumor agents that were originally isolated from the cellular slime mold Dictyostelium discoideum. Here we investigated the effects of a panel of DIF derivatives on lysophosphatidic acid (LPA)-induced migration of mouse osteosarcoma LM8 cells by using a Boyden chamber assay. Some DIF derivatives such as Br-DIF-1, DIF-3(+2), and Bu-DIF-3 (5–20 μM) dose-dependently suppressed LPA-induced cell migration with associated IC50 values of 5.5, 4.6, and 4.2 μM, respectively. On the other hand, the IC50 values of Br-DIF-1, DIF-3(+2), and Bu-DIF-3 versus cell proliferation were 18.5, 7.2, and 2.0 μM, respectively, in LM8 cells, and >20, 14.8, and 4.3 μM, respectively, in mouse 3T3-L1 fibroblasts (non-transformed). Together, our results demonstrate that Br-DIF-1 in particular may be a valuable tool for the analysis of cancer cell migration, and that DIF derivatives such as DIF-3(+2) and Bu-DIF-3 are promising lead anti-tumor agents for the development of therapies that suppress osteosarcoma cell proliferation, migration, and metastasis. - Highlights: • LPA induces cell migration (invasion) in murine osteosarcoma LM8 cells. • DIFs are novel lead anti-tumor agents found in Dictyostelium discoideum. • We examined the effects of DIF derivatives on LPA-induced LM8 cell migration in vitro. • Some of the DIF derivatives inhibited LPA-induced LM8 cell migration

  8. Derivatives of Dictyostelium differentiation-inducing factors inhibit lysophosphatidic acid–stimulated migration of murine osteosarcoma LM8 cells

    Kubohara, Yuzuru, E-mail: ykuboha@juntendo.ac.jp [Department of Molecular and Cellular Biology, Institute for Molecular and Cellular Regulation (IMCR), Gunma University, Maebashi 371-8512 (Japan); Department of Health Science, Juntendo University Graduate School of Health and Sports Science, Inzai 270-1695 (Japan); Komachi, Mayumi [Department of Molecular and Cellular Biology, Institute for Molecular and Cellular Regulation (IMCR), Gunma University, Maebashi 371-8512 (Japan); Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi 371-8511 (Japan); Homma, Yoshimi [Department of Biomolecular Science, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima 960-1295 (Japan); Kikuchi, Haruhisa; Oshima, Yoshiteru [Laboratory of Natural Product Chemistry, Tohoku University Graduate School of Pharmaceutical Sciences, Aoba-yama, Aoba-ku, Sendai 980-8578 (Japan)

    2015-08-07

    Osteosarcoma is a common metastatic bone cancer that predominantly develops in children and adolescents. Metastatic osteosarcoma remains associated with a poor prognosis; therefore, more effective anti-metastatic drugs are needed. Differentiation-inducing factor-1 (DIF-1), −2, and −3 are novel lead anti-tumor agents that were originally isolated from the cellular slime mold Dictyostelium discoideum. Here we investigated the effects of a panel of DIF derivatives on lysophosphatidic acid (LPA)-induced migration of mouse osteosarcoma LM8 cells by using a Boyden chamber assay. Some DIF derivatives such as Br-DIF-1, DIF-3(+2), and Bu-DIF-3 (5–20 μM) dose-dependently suppressed LPA-induced cell migration with associated IC{sub 50} values of 5.5, 4.6, and 4.2 μM, respectively. On the other hand, the IC{sub 50} values of Br-DIF-1, DIF-3(+2), and Bu-DIF-3 versus cell proliferation were 18.5, 7.2, and 2.0 μM, respectively, in LM8 cells, and >20, 14.8, and 4.3 μM, respectively, in mouse 3T3-L1 fibroblasts (non-transformed). Together, our results demonstrate that Br-DIF-1 in particular may be a valuable tool for the analysis of cancer cell migration, and that DIF derivatives such as DIF-3(+2) and Bu-DIF-3 are promising lead anti-tumor agents for the development of therapies that suppress osteosarcoma cell proliferation, migration, and metastasis. - Highlights: • LPA induces cell migration (invasion) in murine osteosarcoma LM8 cells. • DIFs are novel lead anti-tumor agents found in Dictyostelium discoideum. • We examined the effects of DIF derivatives on LPA-induced LM8 cell migration in vitro. • Some of the DIF derivatives inhibited LPA-induced LM8 cell migration.

  9. Cell Shrinkage is Essential in Lysophosphatidic Acid Signaling in Ehrlich Ascites

    Pedersen, Susanne; Hoffmann, Else Kay; Hougaard, Charlotte;

    2000-01-01

    ; (ii) a subsequent cell shrinkage and increased polymerization of F-actin, and (iii) activation of a Na(+)/H(+) exchange, resulting in a concentration-dependent intracellular alkalinization. The EC(50) value for the LPA-induced rate of alkalinization was estimated at 0. 37 nm LPA. When cell shrinkage...

  10. Lysophosphatidic acid (LPA) signaling in neuropathic pain development and Schwann cell biology

    Lin, Mu-En

    2012-01-01

    Neuropathic pain is a chonic pain state caused by lesions or diseases in the nervous system. Unlike acute pain, neuropathic pain persists without obvious injury or stimuli and can severely interfere with normal daily life for those who suffer from it. Despite numerous efforts on studying its mechanism and possible treatments, there is no effective treatment currently available to remove or alleviate this symptom. This dissertation aims to provide further understanding into the relationship be...

  11. Spinal cord injury: Role of endothelial differentiation gene family lysophosphatidic acid receptors

    Santos Nogueira, Eva

    2014-01-01

    El daño tisular secundario que se produce tras una lesión de la médula espinal contribuye de manera significativa a las pérdidas funcionales que se observan pacientes que padecen este tipo de afectación. Aunque la regeneración axonal y la sustitución de las neuronas dañadas tras el traumatismo medular son objetivos importantes para reparar estas lesiones, el desarrollo de estrategias experimentales que tengan como meta evitar el daño secundario sobre axones, neuronas, mielina y las células gl...

  12. L-histidine inhibits production of lysophosphatidic acid by the tumor-associated cytokine, autotaxin

    Schiffmann Elliott

    2005-02-01

    Full Text Available Abstract Background Autotaxin (ATX, NPP-2, originally purified as a potent tumor cell motility factor, is now known to be the long-sought plasma lysophospholipase D (LPLD. The integrity of the enzymatic active site, including three crucial histidine moieties, is required for motility stimulation, as well as LPLD and 5'nucleotide phosphodiesterase (PDE activities. Except for relatively non-specific chelation agents, there are no known inhibitors of the ATX LPLD activity. Results We show that millimolar concentrations of L-histidine inhibit ATX-stimulated but not LPA-stimulated motility in two tumor cell lines, as well as inhibiting enzymatic activities. Inhibition is reversed by 20-fold lower concentrations of zinc salt. L-histidine has no significant effect on the Km of LPLD, but reduces the Vmax by greater than 50%, acting as a non-competitive inhibitor. Several histidine analogs also inhibit the LPLD activity of ATX; however, none has greater potency than L-histidine and all decrease cell viability or adhesion. Conclusion L-histidine inhibition of LPLD is not a simple stoichiometric chelation of metal ions but is more likely a complex interaction with a variety of moieties, including the metal cation, at or near the active site. The inhibitory effect of L-histidine requires all three major functional groups of histidine: the alpha amino group, the alpha carboxyl group, and the metal-binding imidazole side chain. Because of LPA's involvement in pathological processes, regulation of its formation by ATX may give insight into possible novel therapeutic approaches.

  13. Expression of Castor LPAT2 Enhances Ricinoleic Acid Content at the sn-2 Position of Triacylglycerols in Lesquerella Seed

    Grace Q. Chen; Harrie van Erp; Jose Martin-Moreno; Kumiko Johnson; Eva Morales; John Browse; Peter J. Eastmond; Jiann-Tsyh Lin

    2016-01-01

    Lesquerella is a potential industrial oilseed crop that makes hydroxy fatty acid (HFA). Unlike castor its seeds are not poisonous but accumulate lesquerolic acid mostly at the sn-1 and sn-3 positions of triacylglycerol (TAG), whereas castor contains ricinoleic acid (18:1OH) at all three positions. To investigate whether lesquerella can be engineered to accumulate HFAs in the sn-2 position, multiple transgenic lines were made that express castor lysophosphatidic acid acyltransferase 2 (RcLPAT2...

  14. A dependence of nuclear structure functions

    We show that clustering of nucleons, with confinement-size changes, naturally explains and accurately describes recent data on the A dependence of deep-inelastic nuclear cross sections. Predictions for gluon distributions in nuclei are given

  15. Analysis of the ligand binding properties of recombinant bovine liver-type fatty acid binding protein

    Rolf, B; Oudenampsen-Krüger, E; Börchers, T;

    1995-01-01

    The coding part of the cDNA for bovine liver-type fatty acid binding protein (L-FABP) has been amplified by RT-PCR, cloned and used for the construction of an Escherichia coli (E. coli) expression system. The recombinant protein made up to 25% of the soluble E. coli proteins and could be isolated...... by a simple two step protocol combining ion exchange chromatography and gel filtration. Dissociation constants for binding of oleic acid, arachidonic acid, oleoyl-CoA, lysophosphatidic acid and the peroxisomal proliferator bezafibrate to L-FABP have been determined by titration calorimetry. All ligands were...... bound in a 2:1 stoichiometry, the dissociation constants for the first ligand bound were all in the micro molar range. Oleic acid was bound with the highest affinity and a Kd of 0.26 microM. Furthermore, binding of cholesterol to L-FABP was investigated with the Lipidex assay, a liposome binding assay...

  16. The Effect of Lysophosphatidic Acid during In Vitro Maturation of Bovine Oocytes: Embryonic Development and mRNA Abundances of Genes Involved in Apoptosis and Oocyte Competence

    Dorota Boruszewska; Ana Catarina Torres; Ilona Kowalczyk-Zieba; Patricia Diniz; Mariana Batista; Luis Lopes-da-Costa; Izabela Woclawek-Potocka

    2014-01-01

    In the present study we examined whether LPA can be synthesized and act during in vitro maturation of bovine cumulus oocyte complexes (COCs). We found transcription of genes coding for enzymes of LPA synthesis pathway (ATX and PLA2) and of LPA receptors (LPAR 1–4) in bovine oocytes and cumulus cells, following in vitro maturation. COCs were matured in vitro in presence or absence of LPA (10−5 M) for 24 h. Supplementation of maturation medium with LPA increased mRNA abundance of FST and GDF9 i...

  17. Gene : CBRC-RMAC-15-0027 [SEVENS

    Full Text Available PREDICTED: similar to endothelial differentiation, lysophosphatidic acid G-protein-coupled receptor, 2 isofo...rm 1 [Macaca mulatta] ref|XP_001106110.1| PREDICTED: similar to endothelial differentiation, lysophosphatidic acid...1| PREDICTED: similar to endothelial differentiation, lysophosphatidic acid G-protein-coupled receptor, 2 is...33369948 PREDICTED: Macaca mulatta similar to endothelial differentiation, lysophosphatidic acid... G-protein-coupled receptor, 2, transcript variant 3 (LOC709208), mRNA /cds=p(427,1521) /gb=X

  18. The effect of charge reversal mutations in the alpha-helical region of liver fatty acid binding protein on the binding of fatty-acyl CoAs, lysophospholipids and bile acids.

    Hagan, Robert M; Davies, Joanna K; Wilton, David C

    2002-10-01

    Liver fatty acid binding protein (LFABP) is unique among the various types of FABPs in that it can bind a variety of ligands in addition to fatty acids. LFABP is able to bind long chain fatty acids with a 2:1 stoichiometry and the crystal structure has identified two fatty acid binding sites in the binding cavity. The presumed primary site (site 1) involves the fatty acid binding with the carboxylate group buried in the cavity whereas the fatty acid at site 2 has the carboxylate group solvent-exposed within the ligand portal region and in the vicinity of alpha-helix II. The alpha-helical region contains three cationic residues, K20, K31, K33 and modelling studies suggest that K31 on alpha-helix II could make an electrostatic contribution to anionic ligands binding to site 2. The preparation of three charge reversal mutants of LFABP, K20E, K31E and K33E has allowed an investigation of the role of site 2 in ligand binding, particularly those ligands with a bulky anionic head group. The binding of oleoyl CoA, lysophosphatidic acid, lysophosphatidylcholine, lithocholic acid and taurolithocholate 3-sulphate to LFABP has been studied using the alpha-helical mutants. The results support the concept that such ligands bind at site 2 of LFABP where solvent exposure allows the accommodation of their bulky anionic group. PMID:12479568

  19. Consequencs of a Dependence of GRB Properties on Local Metallicity

    Ramirez-Ruiz, Enrico; Blain, Andrew W.; Lazzati, Davide

    2003-01-01

    We report a correlation between the isotropic equivalent energy of GRBs and their position offset from their host galaxies. This is possibly due to a dependence of the end point of massive stellar evolution on metallicity. If confirmed in further host observations, this correlation will both complicate interpretation of GRBs as tracers of cosmic star formation, and potentially allow a new probe of the astrophysics in high-redshift galaxies.

  20. Expression of Castor LPAT2 Enhances Ricinoleic Acid Content at the sn-2 Position of Triacylglycerols in Lesquerella Seed

    Chen, Grace Q.; van Erp, Harrie; Martin-Moreno, Jose; Johnson, Kumiko; Morales, Eva; Browse, John; Eastmond, Peter J.; Lin, Jiann-Tsyh

    2016-01-01

    Lesquerella is a potential industrial oilseed crop that makes hydroxy fatty acid (HFA). Unlike castor its seeds are not poisonous but accumulate lesquerolic acid mostly at the sn-1 and sn-3 positions of triacylglycerol (TAG), whereas castor contains ricinoleic acid (18:1OH) at all three positions. To investigate whether lesquerella can be engineered to accumulate HFAs in the sn-2 position, multiple transgenic lines were made that express castor lysophosphatidic acid acyltransferase 2 (RcLPAT2) in the seed. RcLPAT2 increased 18:1OH at the sn-2 position of TAGs from 2% to 14%–17%, which resulted in an increase of tri-HFA-TAGs from 5% to 13%–14%. Our result is the first example of using a LPAT to increase ricinoleic acid at the sn-2 position of seed TAG. This work provides insights to the mechanism of HFA-containing TAG assembly in lesquerella and directs future research to optimize this plant for HFA production. PMID:27058535

  1. Clinical study on lysophospholipids acid, D_dimers detection in the prediction of progress and application effect of cerebral apoplexy%溶血磷脂酸、D-二聚体检测预测进展性脑卒中的临床应用研究

    胡红晓

    2014-01-01

    Objective:To study the lysophospholipids acid , D_dimers detection in the prediction of progress and application effect of cerebral apoplexy .Methods:Our hospital in April 2012 to April 2013 were 35 patients with progressive stroke ( research group ) , physical examination, 35 cases (control group) as the research object, research on two groups of objects of D -dimer, lysophosphatide acid level testing and comparison .Results:The group D -dimer level of patients >75 mu g/L, positive;Control the research object of D -dimer level <75 mu g/L, negative;Group patients were lysophospholipids , D -dimer acid average levels were significantly higher than that of control group, P <0.05).Conclusion:D -dimer, lysophosphatide acid was an important molecular markers of early thrombosis in vivo, by detecting D -dimer, lysophosphatide acid levels , could provide effective basis for clinical prediction progress sex stroke .%目的:探讨溶血磷脂酸、D-二聚体检测在预测进展性脑卒中的应用效果。方法:选取我院在2012年4月~2013年4月收治的进展性脑卒中患者35例(研究组)、健康体检者35例(对照组)作为研究对象,对2组研究对象的D-二聚体、溶血磷脂酸水平进行检测、比较。结果:研究组患者的D-二聚体水平均>75μg/L,呈阳性;对照组研究对象的D-二聚体水平均<75μg/L,呈阴性;研究组患者的溶血磷脂酸、D-二聚体平均水平均显著高于对照组,P<0.05。结论:D-二聚体、溶血磷脂酸是体内早期血栓形成的重要分子标志物,通过检测D-二聚体、溶血磷脂酸水平,可为临床预测进展性脑卒中提供有效依据。

  2. Age-related changes in retinoic, docosahexaenoic and arachidonic acid modulation in nuclear lipid metabolism.

    Gaveglio, Virginia L; Pascual, Ana C; Giusto, Norma M; Pasquaré, Susana J

    2016-08-15

    The aim of this work was to study how age-related changes could modify several enzymatic activities that regulate lipid mediator levels in nuclei from rat cerebellum and how these changes are modulated by all-trans retinoic acid (RA), docosahexaenoic acid (DHA) and arachidonic acid (AA). The higher phosphatidate phosphohydrolase activity and lower diacylglycerol lipase (DAGL) activity observed in aged animals compared with adults could augment diacylglycerol (DAG) availability in the former. Additionally, monoacylglycerol (MAG) availability could be high due to an increase in lysophosphatidate phosphohydrolase (LPAPase) activity and a decrease in monocylglycerol lipase activity. Interestingly, RA, DHA and AA were observed to modulate these enzymatic activities and this modulation was found to change in aged rats. In adult nuclei, whereas RA led to high DAG and MAG production through inhibition of their hydrolytic enzymes, DHA and AA promoted high MAG production by LPAPase and DAGL stimulation. In contrast, in aged nuclei RA caused high MAG generation whereas DHA and AA diminished it through LPAPase activity modulation. These results demonstrate that aging promotes a different nuclear lipid metabolism as well as a different type of non-genomic regulation by RA, DHA and AA, which could be involved in nuclear signaling events. PMID:27355428

  3. Metabolic engineering of medium-chain fatty acid biosynthesis in Nicotiana benthamiana plant leaf lipids.

    Reynolds, Kyle B; Taylor, Matthew C; Zhou, Xue-Rong; Vanhercke, Thomas; Wood, Craig C; Blanchard, Christopher L; Singh, Surinder P; Petrie, James R

    2015-01-01

    Various research groups are investigating the production of oil in non-seed biomass such as leaves. Recently, high levels of oil accumulation have been achieved in plant biomass using a combination of biotechnological approaches which also resulted in significant changes to the fatty acid composition of the leaf oil. In this study, we were interested to determine whether medium-chain fatty acids (MCFA) could be accumulated in leaf oil. MCFA are an ideal feedstock for biodiesel and a range of oleochemical products including lubricants, coatings, and detergents. In this study, we explore the synthesis, accumulation, and glycerolipid head-group distribution of MCFA in leaves of Nicotiana benthamiana after transient transgenic expression of C12:0-, C14:0-, and C16:0-ACP thioesterase genes. We demonstrate that the production of these MCFA in leaf is increased by the co-expression of the WRINKLED1 (WRI1) transcription factor, with the lysophosphatidic acid acyltransferase (LPAAT) from Cocos nucifera being required for the assembly of tri-MCFA TAG species. We also demonstrate that the newly-produced MCFA are incorporated into the triacylglycerol of leaves in which WRI1 + diacylglycerol acyltransferase1 (DGAT1) genes are co-expressed for increased oil accumulation. PMID:25852716

  4. Amino acids

    Amino acids are organic compounds that combine to form proteins . Amino acids and proteins are the building blocks of life. When proteins are digested or broken down, amino acids are left. The human body uses amino acids ...

  5. A Dependent Hidden Markov Model of Credit Quality

    Małgorzata Wiktoria Korolkiewicz

    2012-01-01

    Full Text Available We propose a dependent hidden Markov model of credit quality. We suppose that the "true" credit quality is not observed directly but only through noisy observations given by posted credit ratings. The model is formulated in discrete time with a Markov chain observed in martingale noise, where "noise" terms of the state and observation processes are possibly dependent. The model provides estimates for the state of the Markov chain governing the evolution of the credit rating process and the parameters of the model, where the latter are estimated using the EM algorithm. The dependent dynamics allow for the so-called "rating momentum" discussed in the credit literature and also provide a convenient test of independence between the state and observation dynamics.

  6. Fatty acid composition of muscle fat and enzymes of storage lipid synthesis in whole muscle from beef cattle.

    Kazala, E Chris; Lozeman, Fred J; Mir, Priya S; Aalhus, Jennifer L; Schmutz, Sheila M; Weselake, Randall J

    2006-11-01

    Enhanced intramuscular fat content (i.e., marbling) in beef is a desirable trait, which can result in increased product value. This study was undertaken with the aim of revealing biochemical factors associated with the marbling trait in beef cattle. Samples of longissimus lumborum (LL) and pars costalis diaphragmatis (PCD) were taken from a group of intact crossbred males and females at slaughter, lipids extracted, and the resulting FAME examined for relationships with marbling fat deposition. For LL, significant associations were found between degree of marbling and myristic (14:0, r = 0.55, P muscle were assayed for diacylglycerol acyltransferase (DGAT), lysophosphatidic acid acyltransferase (LPAAT), and phosphatidic acid phosphatase-1 (PAP-1) activity, and the results examined for relationships with degree of intramuscular fat deposition. None of the enzyme activities from PCD displayed an association with marbling fat content, but DGAT specific activity showed significant positive associations with LPAAT (r = 0.54, P muscle tissues provide insight into possible enzyme action associated with the production of specific FA. The increased proportion of oleic acid associated with enhanced lipid content of whole muscle is noteworthy given the known health benefits of this FA. PMID:17263304

  7. Acid Rain.

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  8. Folic Acid

    ... found naturally in some foods, including leafy vegetables, citrus fruits, beans (legumes), and whole grains. Folic acid ... mcg of folic acid every day for good health. But older adults need to be sure they ...

  9. Ibotenic acid and thioibotenic acid

    Hermit, Mette B; Greenwood, Jeremy R; Nielsen, Birgitte;

    2004-01-01

    In this study, we have determined and compared the pharmacological profiles of ibotenic acid and its isothiazole analogue thioibotenic acid at native rat ionotropic glutamate (iGlu) receptors and at recombinant rat metabotropic glutamate (mGlu) receptors expressed in mammalian cell lines....... Thioibotenic acid has a distinct pharmacological profile at group III mGlu receptors compared with the closely structurally related ibotenic acid; the former is a potent (low microm) agonist, whereas the latter is inactive. By comparing the conformational energy profiles of ibotenic and thioibotenic acid with...... the conformations preferred by the ligands upon docking to mGlu1 and models of the other mGlu subtypes, we propose that unlike other subtypes, group III mGlu receptor binding sites require a ligand conformation at an energy level which is prohibitively expensive for ibotenic acid, but not for...

  10. [Gastric Acid].

    Ruíz Chávez, R

    1996-01-01

    Gastric acid, a product of parietal cells secretion, full fills multiple biological roles which are absolutely necessary to keep corporal homeostasis. The production of the acid depends upon an effector cellular process represented in the first step by histamine, acetilcholine and gastrin, first messengers of the process. These interact with specific receptors than in sequence activate second messengers -cAMP and the calcium-calmodulin system- which afterwards activate a kinase. An specific protein is then phosphorilated by this enzyme, being the crucial factor that starts the production of acid. Finally, a proton bomb, extrudes the acid towards the gastric lumen. The secretion process mentioned above, is progressive lyactivated in three steps, two of which are stimulators -cephalic and gastric phases- and the other one inhibitor or intestinal phase. These stages are started by mental and neurological phenomena -thought, sight, smell or memory-; by food, drugs or other ingested substances; and by products of digestion. Changes in regulation of acid secretion, in the structure of gastro-duodenal mucosal barrier by a wide spectrum of factors and agents including food, drugs and H. pylori, are the basis of acid-peptic disease, entity in which gastric acid plays a fundamental role. From the therapeutic point of view, so at the theoretical as at the practical levels, t is possible to interfere with the secretion of acid by neutralization of some of the steps of the effector cellular process. An adequate knowledge of the basics related to gastric acid, allows to create strategies for the clinical handling of associated pathology, specifically in relation to peptic acid disease in all of the known clinical forms. PMID:12165790

  11. Folic acid

    ... include leafy vegetables (such as spinach, broccoli, and lettuce), okra, asparagus, fruits (such as bananas, melons, and ... Pyrimethamine (Daraprim)Pyrimethamine (Daraprim) is used to treat parasite infections. Folic acid might decrease the effectiveness of ...

  12. Folic Acid

    Full Text Available ... March of Dimes Premature Birth Report Card Grades Cities, Counties; Focuses on Racial and Ethnic Disparities March ... your baby. Learn how you can get the right amout of folic acid before and during pregnancy ...

  13. ACID RAIN

    Acid precipitation has become one of the major environmental problems of this decade. It is a challenge to scientists throughout the world. Researchers from such diverse disciplines as plant pathology, soil science, bacteriology, meteorology and engineering are investigating diff...

  14. Folic Acid

    Full Text Available ... Just a moment, please. You've saved this page It's been added to your dashboard . Folic acid ... Map Premature birth report card Careers Archives Health Topics Pregnancy Before or between pregnancies Nutrition, weight & fitness ...

  15. Folic Acid

    Full Text Available ... Folic acid Description | Related videos | Most played video E-mail to a friend Please fill in all fields. Please enter a valid e-mail address. Your information: Your recipient's information: Your ...

  16. Okadaic acid

    Danielsen, E Michael; Hansen, Gert H; Severinsen, Mai C K

    2014-01-01

    Okadaic acid (OA) is a polyether fatty acid produced by marine dinoflagellates and the causative agent of diarrhetic shellfish poisoning. The effect of OA on apical endocytosis in the small intestine was studied in organ cultured porcine mucosal explants. Within 0.5-1 h of culture, the toxin caused...... endosomes (TWEEs) occurred unimpeded in the presence of OA, FM condensed in larger subapical structures by 1 h, implying a perturbed endosomal trafficking/maturation. The fluorescent lysosomotropic agent Lysotracker revealed induction of large lysosomal structures by OA. Endocytosis from the brush border...

  17. Perfluorooctanoic acid

    P. de Voogt

    2014-01-01

    Perfluorooctanoic acid (PFOA, 335-67-1) is used in fluoropolymer production and firefighting foams and persists in the environment. Human exposure to PFOA is mostly through the diet. PFOA primarily affects the liver and can cause developmental and reproductive toxic effects in test animals.

  18. Ascorbic Acid

    Cevi-Bid® ... If you become pregnant while taking ascorbic acid, call your doctor. ... In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call ...

  19. Stearic Acid

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) is presented for the chemical, stearic acid. The profile lists the chemical's physical and harmful characteristics, exposure limits, and symptoms of major exposure, for the benefit of teachers and students, who use the chemical in the laboratory.

  20. Mefenamic Acid

    Mefenamic acid comes as a capsule to take by mouth. It is usually taken with food every 6 hours as needed for up to 1 week. Follow ... pain vomit that is bloody or looks like coffee grounds black, tarry, or bloody stools slowed breathing ...

  1. Metabolism of β-valine via a CoA-dependent ammonia lyase pathway

    Otzen, Marleen; Crismaru, Ciprian G.; Postema, Christiaan P.; Wijma, Hein J.; Heberling, Matthew M.; Szymanski, Wiktor; de Wildeman, Stefaan; Janssen, Dick B.

    2015-01-01

    Pseudomonas species strain SBV1 can rapidly grow on medium containing β-valine as a sole nitrogen source. The tertiary amine feature of β-valine prevents direct deamination reactions catalyzed by aminotransferases, amino acid dehydrogenases, and amino acid oxidases. However, lyase- or aminomutase-me

  2. Hydroxycarboxylic acids and salts

    Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

    2015-02-24

    Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

  3. Gene : CBRC-CFAM-11-0034 [SEVENS

    Full Text Available DICTED: similar to endothelial differentiation, lysophosphatidic acid G-protein-coupled receptor, 2 isoform 2 [Can...is familiaris] ref|XP_532031.2| PREDICTED: similar to endothelial differentiation, lysophosphatidic acid...#S22754747 PREDICTED: Canis familiaris similar to endothelial differentiation, lysophosphatidic acid G-prote...in-coupled receptor, 2, transcript variant 1 (LOC474800), mRNA /cds=p(92,1132) /gb=XM_532031 /gi=73971553 /u...CBRC-CFAM-11-0034 11 A Lysolipids receptors EDG2_SHEEP 0.0 98% ref|XP_853534.1| PRE

  4. Angiomodulin is a specific marker of vasculature and regulates VEGF-A dependent neo-angiogenesis

    Hooper, Andrea T.; Shmelkov, Sergey V.; Gupta, Sunny; Milde, Till; Bambino, Kathryn; Gillen, Kelly; Goetz, Mollie; Chavala, Sai; Baljevic, Muhamed; Murphy, Andrew J.; Valenzuela, David M; Gale, Nicholas W.; Thurston, Gavin; Yancopoulos, George D.; Vahdat, Linda

    2009-01-01

    Blood vessel formation is controlled by the balance between pro- and anti-angiogenic pathways. Although much is known about the factors that drive sprouting of neovessels, the factors that stabilize and pattern neovessels are undefined. The expression of angiomodulin (AGM), a VEGF-A binding protein, was increased in the vasculature of several human tumors as compared to normal tissue, raising the hypothesis that AGM may modulate VEGF-A-dependent vascular patterning. To elucidate the expressio...

  5. Understanding Acid Rain

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  6. Dehydroabietic acid

    Xiao-Ping Rao

    2009-10-01

    Full Text Available The title compound [systematic name: (1R,4aS,10aR-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthrene-1-carboxylic acid], C20H28O2, has been isolated from disproportionated rosin which is obtained by isomerizing gum rosin with a Pd-C catalyst.. Two crystallographically independent molecules exist in the asymmetric unit. In each molecule, there are three six-membered rings, which adopt planar, half-chair and chair conformations. The two cyclohexane rings form a trans ring junction with the two methyl groups in axial positions. The crystal structure is stabilized by intermolecular O—H...O hydrogen bonds.

  7. Retarded acid emulsion

    Fast, C.R.; Rixe, F.H.; Duffield, E.L. Jr.

    1972-08-01

    Compositions for use in acidizing hydrocarbon-bearing formations are described. Retarded acid emulsions of prolonged stability make it possible for the acid in this form to be displaced substantial distances out into the formation before becoming spent. The action of acid emulsions for use in acidizing hydrocarbon-bearing formations is prolonged by employing as the principal emulsifying agent an amine salt of dodecylbenzene sulfonic acid. Acid emulsions employing the amine salt of dodecylbenzene sulfonic acid exhibit greater stability than those employing the free acid. (8 claims)

  8. PUMA promotes Bax translocation in FOXO3a-dependent pathway during STS-induced apoptosis

    Zhang, Yingjie; Chen, Qun

    2009-08-01

    PUMA (p53 up-regulated modulator of apoptosis, also called Bbc3) was first identified as a BH3-only Bcl-2 family protein that is transcriptionally up-regulated by p53 and activated upon p53-dependent apoptotic stimuli, such as treatment with DNA-damaging drugs or UV irradiation. Recently studies have been shown that Puma is also up-regulated in response to certain p53-independent apoptotic stimuli, such as growth factor deprivation or treatment with glucocorticoids or STS (staurosporine). However, the molecular mechanisms of PUMA up-regulation and how PUMA functions in response to p53-independent apoptotic stimuli remain poorly understood. In this study, based on real-time single cell analysis, flow cytometry and western blotting technique, we investigated the function of PUMA in living human lung adenocarcinoma cells (ASTC-a-1) after STS treatment. Our results show that FOXO3a was activated by STS stimulation and then translocated from cytosol to nucleus. The expression of PUMA was up-regulated via a FOXO3a-dependent manner after STS treatment, while p53 had little function in this process. Moreover, cell apoptosis and Bax translocation induced by STS were not blocked by Pifithrin-α (p53 inhibitor), which suggested that p53 was not involved in this signaling pathway. Taken together, these results indicate that PUMA promoted Bax translocation in a FOXO3a-dependment pathway during STS-induced apoptosis, while p53 was dispensable in this process.

  9. RNA G-quadruplexes cause eIF4A-dependent oncogene translation in cancer

    Wolfe, Andrew L.; Singh, Kamini; Zhong, Yi; Drewe, Philipp; Rajasekhar, Vinagolu K.; Sanghvi, Viraj R.; Mavrakis, Konstantinos J.; Jiang, Man; Roderick, Justine E.; van der Meulen, Joni; Schatz, Jonathan H.; Rodrigo, Christina M.; Zhao, Chunying; Rondou, Pieter; de Stanchina, Elisa; Teruya-Feldstein, Julie; Kelliher, Michelle A.; Speleman, Frank; Porco, John A.; Pelletier, Jerry; Rätsch, Gunnar; Wendel, Hans-Guido

    2014-09-01

    The translational control of oncoprotein expression is implicated in many cancers. Here we report an eIF4A RNA helicase-dependent mechanism of translational control that contributes to oncogenesis and underlies the anticancer effects of silvestrol and related compounds. For example, eIF4A promotes T-cell acute lymphoblastic leukaemia development in vivo and is required for leukaemia maintenance. Accordingly, inhibition of eIF4A with silvestrol has powerful therapeutic effects against murine and human leukaemic cells in vitro and in vivo. We use transcriptome-scale ribosome footprinting to identify the hallmarks of eIF4A-dependent transcripts. These include 5' untranslated region (UTR) sequences such as the 12-nucleotide guanine quartet (CGG)4 motif that can form RNA G-quadruplex structures. Notably, among the most eIF4A-dependent and silvestrol-sensitive transcripts are a number of oncogenes, superenhancer-associated transcription factors, and epigenetic regulators. Hence, the 5' UTRs of select cancer genes harbour a targetable requirement for the eIF4A RNA helicase.

  10. Plasma amino acids

    Amino acids blood test ... types of methods used to determine the individual amino acid levels in the blood. ... test is done to measure the level of amino acids in the blood. An increased level of a ...

  11. Acid Lipase Disease

    ... Enhancing Diversity Find People About NINDS NINDS Acid Lipase Disease Information Page Synonym(s): Cholesterol Ester Storage Disease, ... Related NINDS Publications and Information What is Acid Lipase Disease ? Acid lipase disease or deficiency occurs when ...

  12. POLYELEOSTEARIC ACID VESICLES

    LI Zichen; XIE Ximng; FAN Qinghua; FANG Yifei

    1992-01-01

    α-Eleostearic acid and β-eleostearic acid formed vesicles in aqueous medium when an ethanol solutionofeleostearic acid was injected rapidly into a vigorously vortexed aqueous phase. Formation of the vesicles was demonstrated by electron microscopic observation and bromothymol blue encapsulation experiments. Polymerizations of the eleostearic acids in the formed vesicles carried out by UV irradiation produced poly-α-eleostearic acid and poly-β-eleostearic acid vesicles.

  13. $A$-dependence of coherent electroproduction of $\\rho^{0}$ mesons on nuclei in forward direction

    Akopov, N; Aslanyan, G; Grigoryan, L

    2007-01-01

    This article presents the $A$-dependence of the differential cross section for the coherent electroproduction of vector mesons on nuclei in forward direction, at fixed values of longitudinal momentum transfer $q_{L}$. It is shown that such cross section has complicated behavior over the atomic mass number $A$ with local minimums and maximums. It is also shown that a ratio of the real to the imaginary parts of the forward coherent amplitude on nuclei $\\alpha_{A} = \\Re e{f_{A}} / \\Im m{f_{A}}$ has breaking points at some values of $A$. Comparison of the behaviors of the normalized cross section $\\Big(\\frac{d\\sigma}{d\\Omega}\\Big)_{A}\\Big/\\Big(\\frac{d\\sigma}{d\\Omega}\\Big)_{N}$ and $\\alpha_{A}$ over $A$ shows that the location of minimums of the cross section are very close to the breaking points of $\\alpha_{A}$.

  14. A-dependence of the Spectra of the F Isotopes from ab initio Calculations

    Barrett, Bruce R.; Dikmen, Erdal; Maris, Pieter; Vary, James P.; Shirokov, Andrey M.

    2016-03-01

    Using a succession of Okubo-Lee-Suzuki transformations within the No Core Shell Model (NCSM) formalism, we derive an ab initio, non-perturbative procedure for calculating the input for standard shell-model (SSM) calculations within one major shell. We have used this approach for calculating the spectra of the F isotopes from A=18 to A=25, so as to study the A-dependence of the results. In particular, we are interested in seeing if the theoretical input is weak enough, so that a single set of two-body effective interactions can be used for all of the F isotopes investigated. We will present results from SSM calculations based on input obtained with the JISP16 nucleon-nucleon interaction in an initial 4 ℏΩ NCSM basis space. This work supported in part by TUBITAK-BIDEB, the US DOE, the US NSF, NERSC, and the Russian Ministry of Education and Science.

  15. Measurement of the $Z/A$ dependence of neutrino charged-current total cross-sections

    Kayis-Topaksu, A; Van Dantzig, R; De Jong, M; Konijn, J; Melzer, O; Oldeman, R G C; Pesen, E; Van der Poel, C A F J; Spada, F R; Visschers, J L; Güler, M; Serin-Zeyrek, M; Kama, S; Sever, R; Tolun, P; Zeyrek, M T; Armenise, N; Catanesi, M G; De Serio, M; Ieva, M; Muciaccia, M T; Radicioni, E; Simone, S; Bülte, A; Winter, Klaus; El-Aidi, R; Van de Vyver, B; Vilian, P; Wilquet, G; Saitta, B; Di Capua, E; Ogawa, S; Shibuya, H; Artamonov, A V; Brunner, J; Chizhov, M; Cussans, D G; Doucet, M; Fabre, Jean-Paul; Hristova, I R; Kawamura, T; Kolev, D; Litmaath, M; Meinhard, H; Panman, J; Papadopoulos, I M; Ricciardi, S; Rozanov, A; Saltzberg, D; Tsenov, R V; Uiterwijk, J W E; Zucchelli, P; Goldberg, J; Chikawa, M; Arik, E; Song, J S; Yoon, C S; Kodama, K; Ushida, N; Aoki, S; Hara, T; Delbar, T; Favart, D; Grégoire, G; Kalinin, S; Makhlyoueva, I V; Gorbunov, P; Khovanskii, V D; Shamanov, V V; Tsukerman, I; Bruski, N; Frekers, D; Rondeshagen, D; Wolff, T; Hoshino, K; Kawada, J; Komatsu, M; Miyanishi, M; Nakamura, M; Nakano, T; Narita, K; Niu, K; Niwa, K; Nonaka, N; Sato, O; Toshito, T; Buontempo, S; Cocco, A G; D'Ambrosio, N; De Lellis, G; De Rosa, G; Di Capua, F; Ereditato, A; Fiorillo, G; Marotta, A; Messina, M; Migliozzi, P; Pistillo, C; Santorelli, R; Scotto-Lavina, L; Strolin, P; Tioukov, V; Nakamura, K; Okusawa, T; Dore, U; Loverre, P F; Ludovici, L; Maslennikov, A L; Righini, P; Rosa, G; Santacesaria, R; Satta, A; Barbuto, E; Bozza, C; Grella, G; Romano, G; Sirignano, C; Sorrentino, S; Sato, Y; Tezuka, I

    2003-01-01

    A relative measurement of total cross-sections is reported for polyethylene, marble, iron, and lead targets for the inclusive charged-current reaction nu_mu + N -> mu^- + X. The targets, passive blocks of ~100kg each, were exposed simultaneously to the CERN SPS wide-band muon-neutrino beam over a period of 18 weeks. Systematics effects due to differences in the neutrino flux and detector efficiency for the different target locations were minimised by changing the position of the four targets on their support about every two weeks. The relative neutrino fluxes on the targets were monitored within the same experiment using charged-current interactions in the calorimeter positioned directly downstream of the four targets. From a fit to the Z/A dependence of the total cross-sections a value is deduced for the effective neutron-to-proton cross-section ratio.

  16. Measurement of the Z/A dependence of neutrino charged-current total cross-sections

    Kayis-Topasku, A; Dantzig, R V

    2003-01-01

    A relative measurement of total cross-sections is reported for polyethylene, marble, iron, and lead targets for the inclusive charged-current reaction nu submu + N -> mu sup - + X. The targets, passive blocks of propor to 100 kg each, were exposed simultaneously to the CERN SPS wide-band muon-neutrino beam over a period of 18 weeks. Systematic effects due to differences in the neutrino flux and detector efficiency for the different target locations were minimised by changing the position of the four targets on their support about every two weeks. The relative neutrino fluxes on the targets were monitored within the same experiment using charged-current interactions in the calorimeter positioned directly downstream of the four targets. From a fit to the Z/A dependence of the total cross-sections a value is deduced for the effective neutron-to-proton cross-section ratio. (orig.)

  17. A-dependence of differential multiplicity at 7 GeV/c

    Particle production in the inelastic proton-nucleus interactions have been investigated at the initial momentum psub(0)=7 GeV/c for Be, Al, C, Cu, Cd and Pb nuclei. A-dependences of both π- and p differential multiplicities are parametrized as approximately Asup(α(sub(i)))i. Similar parametrization seems to be also suitable for the normalized topological cross-section Wsup(n-)(A) of the processes with nsup(-) forward emitted negative pions. The dependence of αsub(i) on the secondary particle type and its kinematic region for (A) and on n- for Wsup(n-)(A) has been obtained. These experimental data indicate to secondary interactions of the produced particles inside nucleus. The total multiplicity distribution is observed to obey KNO scaling

  18. Acid distribution in phosphoric acid fuel cells

    Okae, I.; Seya, A.; Umemoto, M. [Fuji Electric Co., Ltd., Chiba (Japan)

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  19. Nuclear Envelope Protein SUN2 Promotes Cyclophilin-A-Dependent Steps of HIV Replication

    Lahaye, Xavier; Satoh, Takeshi; Gentili, Matteo; Cerboni, Silvia; Silvin, Aymeric; Conrad, Cécile; Ahmed-Belkacem, Abdelhakim; Rodriguez, Elisa C.; Guichou, Jean-François; Bosquet, Nathalie; Piel, Matthieu; Le Grand, Roger; King, Megan C.; Pawlotsky, Jean-Michel; Manel, Nicolas

    2016-01-01

    Summary During the early phase of replication, HIV reverse transcribes its RNA and crosses the nuclear envelope while escaping host antiviral defenses. The host factor Cyclophilin A (CypA) is essential for these steps and binds the HIV capsid; however, the mechanism underlying this effect remains elusive. Here, we identify related capsid mutants in HIV-1, HIV-2, and SIVmac that are restricted by CypA. This antiviral restriction of mutated viruses is conserved across species and prevents nuclear import of the viral cDNA. Importantly, the inner nuclear envelope protein SUN2 is required for the antiviral activity of CypA. We show that wild-type HIV exploits SUN2 in primary CD4+ T cells as an essential host factor that is required for the positive effects of CypA on reverse transcription and infection. Altogether, these results establish essential CypA-dependent functions of SUN2 in HIV infection at the nuclear envelope. PMID:27149839

  20. Gene : CBRC-CFAM-06-0034 [SEVENS

    Full Text Available gnl|UG|Cfa#S22754747 PREDICTED: Canis familiaris similar to endothelial differentiation, lysophosphatidic acid...ICTED: similar to Lysophosphatidic acid receptor Edg-7 (LPA receptor 3) (LPA-3) [Canis familiaris] 0.0 100% ... G-protein-coupled receptor, 2, transcript variant 1 (LOC474800), mRNA /cds=p(9...CBRC-CFAM-06-0034 6 A Lysolipids receptors EDG7_HUMAN 0.0 93% ref|XP_547308.2| PRED

  1. Gene : CBRC-RMAC-01-0033 [SEVENS

    Full Text Available REDICTED: endothelial differentiation, lysophosphatidic acid G-protein-coupled receptor, 7 [Macaca mulatta] ...0.0 100% gnl|UG|Mmu#S33369948 PREDICTED: Macaca mulatta similar to endothelial differentiation, lysophosphatidic acid... G-protein-coupled receptor, 2, transcript variant 3 (LOC709208), mRNA /cds...CBRC-RMAC-01-0033 1 A Lysolipids receptors EDG7_HUMAN 0.0 96% ref|XP_001107923.1| P

  2. Charge-dependent and A-dependent effects in isotope shifts of Coulomb displacement energies

    Coulomb displacement energies in a series of isotopes generally decrease with A. This decrease can arise from an increase with A of the average distance of interaction between pairs of protons. In the shell model a decrease can also result from charge-independence-breaking effects if the neutron-proton interaction for the valence nucleons is more attractive than the neutron-neutron interaction. Using the model recently proposed by Sherr and Talmi for the 1d/sub 3/2/ shell, existing data for this shell and also the 1d/sub 5/2/ and 1f/sub 7/2/ shells were analyzed allowing all matrix elements to vary as A/sup -lambda/3/. Least squares calculations of the rms deviation sigma were carried out for varying values of lambda from -2 to +2. It was found that although there was a minimum in sigma vs lambda it was too shallow to exclude any lambda for -1 to +1 in the 1d/sub 3/2/ and 1f/sub 7/2/ shells or 0 to +1 in the 1d/sub 5/2/ shell. It is therefore not possible to distinguish between A dependence and charge dependence in this model. The magnitude of the latter as expressed in terms of (np-nn) matrix elements depends strongly on the former. As lambda increases from -1 to +1, these (np-nn) matrix elements decrease roughly linearly in absolute magnitude and eventually change sign. For lambda = 0 they have appreciable and reasonable magnitudes for the 1d/sub 3/2/ and 1f/sub 7/2/ shells but for the 1d/sub 5/2/ shell the values are too small to be considered significant

  3. Acid Thunder: Acid Rain and Ancient Mesoamerica

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  4. Acid Deposition Phenomena

    Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Rain and snow are already naturally acidic, but are only considered problematic when less than a ph of 5.0 The main chemical precursors leading to acidic conditions are atmospheric concentrations of sulfur dioxide (SO2) and nitrogen oxides (NOx). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H2SO4) and nitric acids (HNO3), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

  5. Omega-6 Fatty Acids

    ... Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean oils. Other ... ACIDS are as follows:Improving mental development or growth in infants. Adding arachidonic acid (an omega-6 ...

  6. Zoledronic Acid Injection

    ... experience a reaction during the first few days after you receive a dose of zoledronic acid injection. Symptoms ... symptoms may begin during the first 3 days after you receive a dose of zoledronic acid injection and ...

  7. Catalytic Synthesis Lactobionic Acid

    V.G. Borodina

    2014-07-01

    Full Text Available Gold nanoparticles are obtained, characterized and deposited on the carrier. Conducted catalytic synthesis of lactobionic acid from lactose. Received lactobionic acid identify on the IR spectrum.

  8. Plasma amino acids

    Plasma amino acids is a screening test done on infants that looks at the amounts of amino ... Laboratory error High or low amounts of individual plasma amino acids must be considered with other information. ...

  9. Omega-3 Fatty Acids

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount ... the blood in people with very high triglycerides. Omega-3 fatty acids are in a class of medications ...

  10. The Acid Rain Reader.

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  11. Acid Rain Study Guide.

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  12. Immunoglobulin and fatty acids

    2009-01-01

    The present invention relates to a composition comprising 0.1-10 w/w % immunoglobulin (Ig), 4-14 w/w % saturated fatty acids, 4-14 w/w % mono-unsaturated fatty acids and 0-5 w/w % poly-unsaturated fatty acids, wherein the weight percentages are based on the content of dry matter in the composition...

  13. Interpretation of the EMC-SLAC effect and its A dependence in self-consistent approach without exotics

    Possibility of interpretation of the self-consistent description of the EMC-SLAC effect A-dependence on the basis of standard representation of nuclear structure is discussed. Different models suggested for description of the EMC effect satisfying the following requirements: conservation of energy-momentum; conservation of baryon charge; self-consistent description of static, spectroscopic an dynamic characteristics of nucleus; account of space-time picture of the process; absence of free parameters in description of EMC effect A-dependence, are discussed. Results of self-consistent calculations of structure functions for d, 12C, 56Fe, 108Ag are presented. The carried out consideration permitted to conclude that EMC effect and its A dependence are not critical to selection of meson or quark phenomenology and the latter is not applied as exotics at the background of usual description

  14. Cleavage of nucleic acids

    Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor L. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

    2007-12-11

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  15. Cleavage of nucleic acids

    Prudent, James R. (Madison, WI); Hall, Jeff G. (Waunakee, WI); Lyamichev, Victor I. (Madison, WI); Brow; Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

    2010-11-09

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  16. Nucleic acid detection compositions

    Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann (Madison, WI); Dahlberg, James L. (Madison, WI)

    2008-08-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  17. Nucleic acid detection assays

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James E.

    2005-04-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  18. Cleavage of nucleic acids

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann D.; Dahlberg, James E.

    2000-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  19. Acidizing carbonate reservoirs with chlorocarboxylic acid salt solutions

    Richardson, E.A.; Scheuerman, R.F.; Templeton, C.C.

    1978-10-31

    A carbonate reservoir is acidized slowly by injecting an aqueous solution of a chlorocarboxylic acid salt so that the rate of the acidization is limited to the rate at which an acid is formed by the hydrolyzing of the chlorocarboxylate ions. The rate at which a chlorocarboxylic acid salt hydrolyzes to form an acid provides the desired rate of acid-release. A more complete acid-base reaction by chloroacetic acid, as compared to formic, acetic, and proprionic, is due to its being a much stronger acid. The pKa of chloroacetic acid is 2.86, whereas that of formic acid is 3.75, and that of acetic acid is 4.75. The pKa of a solution of a weak acid is the pH exhibited when the concentration of undissociated acid equals the concentration of the acid anion. 14 claims.

  20. Nucleic acid detection kits

    Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann; Kwiatkowski, Robert W.; Vavra, Stephanie H.

    2005-03-29

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of nucleic acid from various viruses in a sample.

  1. Acidic Ionic Liquids.

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition. PMID:27175515

  2. Microorganisms for producing organic acids

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  3. Bile acid sequestrants

    Hansen, Morten; Sonne, David P; Knop, Filip K

    2014-01-01

    Bile acids are synthesized in the liver from cholesterol and have traditionally been recognized for their role in absorption of lipids and in cholesterol homeostasis. In recent years, however, bile acids have emerged as metabolic signaling molecules that are involved in the regulation of lipid and...... glucose metabolism, and possibly energy homeostasis, through activation of the bile acid receptors farnesoid X receptor (FXR) and TGR5. Bile acid sequestrants (BASs) constitute a class of drugs that bind bile acids in the intestine to form a nonabsorbable complex resulting in interruption of the...... enterohepatic circulation. This increases bile acid synthesis and consequently reduces serum low-density lipoprotein cholesterol. Also, BASs improve glycemic control in patients with type 2 diabetes. Despite a growing understanding of the impact of BASs on glucose metabolism, the mechanisms behind their glucose...

  4. Docosahexaenoic Acid Neurolipidomics

    Niemoller, Tiffany D.; Bazan, Nicolas G.

    2009-01-01

    Mediator lipidomics is a field of study concerned with the characterization, structural elucidation and bioactivity of lipid derivatives generated by enzymatic activity. Omega-3 fatty acids have beneficial effects for vision, brain function, cardiovascular function, and immune-inflammatory responses. Docosahexaenoic acid [DHA; 22:6(n-3)], the most abundant essential omega-3 fatty acid in the human body, is selectively enriched and avidly retained in the central nervous system as an acyl chain...

  5. Fatty acids and epigenetics

    Burdge, Graham C; Lillycrop, Karen A.

    2014-01-01

    Purpose of review The purpose of this review is to assess the findings of recent studies on the effects of fatty acids on epigenetic process and the role of epigenetics in regulating fatty acid metabolism. Recent findings The DNA methylation status of the Fads2 promoter was increased in the liver of the offspring of mice fed an ?-linolenic acid-enriched diet during pregnancy. In rats, increasing total maternal fat intake during pregnancy and lactation induced persistent hypermethyl...

  6. USGS Tracks Acid Rain

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  7. Azetidinic amino acids

    Bräuner-Osborne, Hans; Bunch, Lennart; Chopin, Nathalie;

    2005-01-01

    A set of ten azetidinic amino acids, that can be envisioned as C-4 alkyl substituted analogues of trans-2-carboxyazetidine-3-acetic acid (t-CAA) and/or conformationally constrained analogues of (R)- or (S)-glutamic acid (Glu) have been synthesized in a diastereo- and enantiomerically pure form from...... two diastereoisomers that were easily separated and converted in two steps into azetidinic amino acids. Azetidines 35-44 were characterized in binding studies on native ionotropic Glu receptors and in functional assays at cloned metabotropic receptors mGluR1, 2 and 4, representing group I, II and III...

  8. Halogenated fatty acids

    Mu, Huiling; Wesén, Clas; Sundin, Peter

    1997-01-01

    Chlorinated fatty acids have been found to be major contributors to organohalogen compounds in fish, bivalves, jellyfish, and lobster, and they have been indicated to contribute considerably to organohalogens in marine mammals. Brominated fatty acids have been found in marine sponges. Also....... However, a natural production of halogenated fatty acids is also possible. In this paper we summarize the present knowledge of the occurrence of halogenated fatty acids in lipids and suggested ways of their formation. In Part II (Trends Anal. Chem. 16 (1997) 274) we deal with methods of their...

  9. The acid rain primer

    Acid rain continues to be a major problem in North America, and particularly in eastern Canada. This report introduced the topic of acid rain and discussed its formation, measurement, sources, and geographic distribution. The major sources of sulphur dioxide in Canada are smelting metals, burning coal for electrical power generation, industrial emissions (e.g., pulp and paper, petroleum and aluminum industry), and oil and gas extraction and refining. In Canada, the largest source of nitrogen oxide is the burning of fossil fuels by the transportation sector. Problem areas for acid rain in Canada were identified. The effects of acid rain were examined on lakes and aquatic ecosystems, forests and soils, human-made structures and materials, human health, and on visibility. Acid rain policies and programs were then presented from a historical and current context. Ecosystem recovery from acid rain was discussed with reference to acid rain monitoring, atmospheric response to reductions in acid-causing emissions, and ecosystem recovery of lakes, forests, and aquatic ecosystems. Challenges affecting ecosystem recovery were also presented. These challenges include drought and dry weather, decrease of base cations in precipitation, release of sulphate previously stored in soil, mineralization and immobilization of sulphur/sulphates. Last, the report discussed what still needs to be done to improve the problem of acid rain as well as future concerns. These concerns include loss of base cations from forested watersheds and nitrogen deposition and saturation. 21 refs., 2 tabs., 17 figs

  10. THIN-LAYER SEPARATION OF CITRIC ACID CYCLE INTERMEDIATES, LACTIC ACID, AND THE AMINO ACID TAURINE

    This paper describes a two-dimensional mixed-layer method for separating citric acid cycle intermediates, lactic acid and the amino acid taurine. The method cleanly separates all citric acid cycle intermediates tested, excepting citric acid and isocitric acid. The solvents are in...

  11. Molecular Interaction of Pinic Acid with Sulfuric Acid

    Elm, Jonas; Kurten, Theo; Bilde, Merete;

    2014-01-01

    We investigate the molecular interactions between the semivolatile α-pinene oxidation product pinic acid and sulfuric acid using computational methods. The stepwise Gibbs free energies of formation have been calculated utilizing the M06-2X functional, and the stability of the clusters is evaluated...... from the corresponding ΔG values. The first two additions of sulfuric acid to pinic acid are found to be favorable with ΔG values of -9.06 and -10.41 kcal/mol. Addition of a third sulfuric acid molecule is less favorable and leads to a structural rearrangement forming a bridged sulfuric acid-pinic acid...... without the further possibility for attachment of either sulfuric acid or pinic acid. This suggests that pinic acid cannot be a key species in the first steps in nucleation, but the favorable interactions between sulfuric acid and pinic acid imply that pinic acid can contribute to the subsequent growth of...

  12. Amino Acid Crossword Puzzle

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  13. Science of acid rain

    In this report, the mechanism of forming acid rain in the atmosphere and the process of its fall to ground, the mechanism of withering forests by acid substances, and the process of acidifying lakes and marshes are explained. Moreover, the monitoring networks for acid rain and the countermeasures are described. Acid rain is the pollution phenomena related to all environment, that is, atmosphere, hydrosphere, soilsphere, biosphere and so on, and it is a local environmental pollution problem, and at the same time, an international, global environmental pollution problem. In Japan, acid rain has fallen, but the acidification of lakes and marshes is not clear, and the damage to forests is on small scale. However in East Asia region, the release of sulfur oxides and nitrogen oxides is much, and the increase of the effects of acid rain is expected. It is necessary to devise the measures for preventing the damage due to acid rain. The global monitoring networks of World Meteorological Organization and United Nations Environment Program, and those in Europe, USA and Japan are described. The monitoring of acid rain in Japan is behind that in Europe and USA. (K.I.)

  14. Peptide Nucleic Acid Synthons

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  15. Peptide Nucleic Acids

    2004-01-01

    A novel class of compounds known as peptide nucleic acids, bind complementary DNA and RNA strands, and generally do so more strongly than the corresponding DNA or RNA strands while exhibiting increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a...

  16. Locked nucleic acid

    Jepsen, Jan Stenvang; Sørensen, Mads D; Wengel, Jesper;

    2004-01-01

    Locked nucleic acid (LNA) is a class of nucleic acid analogs possessing very high affinity and excellent specificity toward complementary DNA and RNA, and LNA oligonucleotides have been applied as antisense molecules both in vitro and in vivo. In this review, we briefly describe the basic...

  17. Peptide Nucleic Acids

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  18. Peptide Nucleic Acids

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  19. Peptide Nucleic Acids (PNA)

    2002-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  20. Fatty Acid Biosynthesis IX

    Carey, E. M.; Hansen, Heinz Johs. Max; Dils, R.

    1972-01-01

    # 1. I. [I-14C]Acetate was covalently bound to rabbit mammary gland fatty acid synthetase by enzymic transacylation from [I-14C]acetyl-CoA. Per mole of enzyme 2 moles of acetate were bound to thiol groups and up to I mole of acetate was bound to non-thiol groups. # 2. 2. The acetyl-fatty acid...

  1. Characterization of acid tars

    Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain.

  2. Halogenated fatty acids

    Mu, Huiling; Wesén, Clas; Sundin, Peter

    1997-01-01

    . However, a natural production of halogenated fatty acids is also possible. In this paper we summarize the present knowledge of the occurrence of halogenated fatty acids in lipids and suggested ways of their formation. In Part II (Trends Anal. Chem. 16 (1997) 274) we deal with methods of their...

  3. Instrumental Role of Helicobacter pylori γ-Glutamyl Transpeptidase in VacA-Dependent Vacuolation in Gastric Epithelial Cells

    Ling, Samantha Shi Min; Khoo, Lawrence Han Boon; Hwang, Le-Ann; Yeoh, Khay Guan; Ho, Bow

    2015-01-01

    Helicobacter pylori causes cellular vacuolation in host cells, a cytotoxic event attributed to vacuolating cytotoxin (VacA) and the presence of permeant weak bases such as ammonia. We report here the role of γ-glutamyl transpeptidase (GGT), a constitutively expressed secretory enzyme of H. pylori, in potentiating VacA-dependent vacuolation formation in H. pylori-infected AGS and primary gastric cells. The enhancement is brought about by GGT hydrolysing glutamine present in the extracellular m...

  4. Canadian acid rain policy

    On March 13 of 1991, the Prime Minister of Canada, Brian Mulroney and the President of the United States of America, George Bush, signed an Agreement on Air Quality. This agreement enshrines Principle 21 of the 1972 Stockholm Declaration which states that countries are to ensure that activities within their jurisdiction do not cause damage to the environment of another country. This agreement also includes provisions for controlling acid rain. The Agreement on Air Quality followed years of discussion between the two countries and is a significant milestone in the history of Canadian acid rain policy. This paper begins by describing Canadian acid rain policy and its evolution. The paper also outlines the Canada-United States Air Quality Agreement and the effect of the acid rain provisions on deposition in Canada. Finally, it considers the future work that must be undertaken to further resolve the acid rain problem. 8 refs., 5 figs., 1 tab

  5. Synthesis of aminoaldonic acids

    Jørgensen, Christel Thea

    With the aim of synthesising aminoaldonic acids, two 2-acetamido-2-deoxyaldonolactones with D-galacto (6) and D-arabino (11) configuration were prepared from acetylated sugar formazans in analogy with a known procedure. Empolying the same procedure to acetylated sugar phenylhydrazones gave mixtures...... of 2,5-anhydrides and not the expected 2-acetamido-2-deoxy aldose phenylhydrazones. The acetylated phenylhydrazones were found to eliminate acetic acid when heated in aqueous ethanol and 1-phenylazoalkenes could be isolated by crystallisation. By this method the 17, 20, 23 and 25 were prepared from...... aziridino amides 43 and 51 were reductively cleaved with hydrazine to give 3-amino-2,3-dideoxyhexonhydrazides 83 and 85, which were easily converted into the corresponding lactone 84 and acid 86. The aziridine ring of 43 and 51 was also opened with acetic acid to give the 3-amino-3-deoxyhexonic acids 79 and...

  6. Fusidic acid in dermatology

    Schöfer, Helmut; Simonsen, Lene

    1995-01-01

    Studies on the clinical efficacy of fusidic acid in skin and soft-tissue infections (SSTIs), notably those due to Staphylococcus aureus, are reviewed. Oral fusidic acid (tablets dosed at 250 mg twice daily, or a suspension for paediatric use at 20 mg/kg/day given as two daily doses) has shown good...... efficacy and tolerability. Similarly, plain fusidic acid cream or ointment used two or three times daily in SSTIs such as impetigo are clinically and bacteriologically effective, with minimal adverse events. Combination formulations of fusidic acid with 1% hydrocortisone or 0.1% betamethasone achieve...... excellent results in infected eczema by addressing both inflammation and infection. A new lipid-rich combination formulation provides an extra moisturizing effect. Development of resistance to fusidic acid has remained generally low or short-lived and can be minimized by restricting therapy to no more than...

  7. Sulfuric Acid on Europa

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain. This image is based on data gathered by Galileo's near infrared mapping spectrometer.Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks. Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  8. Difficult Decisions: Acid Rain.

    Miller, John A.; Slesnick, Irwin L.

    1989-01-01

    Discusses some of the contributing factors and chemical reactions involved in the production of acid rain, its effects, and political issues pertaining to who should pay for the clean up. Supplies questions for consideration and discussion. (RT)

  9. Folic acid in diet

    ... green leafy vegetables Dried beans and peas (legumes) Citrus fruits and juices Fortified means that vitamins have ... A.D.A.M. Editorial team. Related MedlinePlus Health Topics Folic Acid Browse the Encyclopedia A.D. ...

  10. Citric acid urine test

    ... usually done while you are on a normal diet. Ask your provider for more information. ... acidosis and a tendency to form calcium kidney stones. The ... acid levels: A high carbohydrate diet Estrogen therapy Vitamin D

  11. Stomach acid test

    Gastric acid secretion test ... The test is done after you have not eaten for a while so fluid is all that remains in ... injected into your body. This is done to test the ability of the cells in the stomach ...

  12. Azelaic Acid Topical

    ... pores and by decreasing production of keratin, a natural substance that can lead to the development of ... acid controls acne and rosacea but does not cure these conditions. It may take 4 weeks or ...

  13. Acid rain: An overview

    US Fish and Wildlife Service, Department of the Interior — Summary of the effects of acid rain and related processes, sources, issues, corrective actions, research, current law, potential solutions, political solutions,...

  14. Ethylenediaminetetraacetic acid in endodontics

    Mohammadi, Zahed; Shalavi, Sousan; Jafarzadeh, Hamid

    2013-01-01

    Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA. EDTA reacts with the calcium ions in dentine and forms soluble calcium chelates. A review of the literature and a discussion of the different indications and considerations for...

  15. Utilization of acid tars

    Frolov, A.F.; Denisova, T.L.; Aminov, A.N.

    1987-01-01

    Freshly produced acid tar (FPAT), obtained as refinery waste in treating petroleum oils with sulfuric acid and oleum, contains 80% or more sulfuric acid. Of such tars, pond acid tars, which contain up to 80% neutral petroleum products and sulfonated resins, are more stable, and have found applications in the production of binders for paving materials. In this article the authors are presenting results obtained in a study of the composition and reactivity of FPAT and its stability in storage in blends with asphalts obtained in deasphalting operations, and the possibility of using the FPAT in road construction has been examined. In this work, wastes were used which were obtained in treating the oils T-750, KhF-12, I-8A, and MS-14. Data on the change in group chemical composition of FPAT are shown, and the acidity, viscosity, needle penetration, and softening point of acid tars obtained from different grades of oils are plotted as functions of the storage time. It is also shown that the fresh and hardened FPATs differ in their solubilities in various solvents.

  16. Fatty Acid Biosynthesis IX

    Carey, E. M.; Hansen, Heinz Johs. Max; Dils, R.

    1972-01-01

    # 1. I. [I-14C]Acetate was covalently bound to rabbit mammary gland fatty acid synthetase by enzymic transacylation from [I-14C]acetyl-CoA. Per mole of enzyme 2 moles of acetate were bound to thiol groups and up to I mole of acetate was bound to non-thiol groups. # 2. 2. The acetyl-fatty acid...... synthetase complex was isolated free from acetyl-CoA. It was rapidly hydrolysed at 30°C, but hydrolysis was greatly diminished at o°C and triacetic lactone synthesis occurred. In the presence of malonyl-CoA and NADPH, all the acetate bound to fatty acid synthetase was incorporated into long-chain fatty acids....... Hydrolysis of bound acetate and incorporation of bound acetate into fatty acids were inhibited to the same extent by guanidine hydrochloride. # 3. 3. Acetate was also covalently bound to fatty acid synthetase by chemical acetylation with [I-14C]acetic anhydride in the absence of CoASH. A total of 60 moles of...

  17. Neutron Nucleic Acid Crystallography.

    Chatake, Toshiyuki

    2016-01-01

    The hydration shells surrounding nucleic acids and hydrogen-bonding networks involving water molecules and nucleic acids are essential interactions for the structural stability and function of nucleic acids. Water molecules in the hydration shells influence various conformations of DNA and RNA by specific hydrogen-bonding networks, which often contribute to the chemical reactivity and molecular recognition of nucleic acids. However, X-ray crystallography could not provide a complete description of structural information with respect to hydrogen bonds. Indeed, X-ray crystallography is a powerful tool for determining the locations of water molecules, i.e., the location of the oxygen atom of H2O; however, it is very difficult to determine the orientation of the water molecules, i.e., the orientation of the two hydrogen atoms of H2O, because X-ray scattering from the hydrogen atom is very small.Neutron crystallography is a specialized tool for determining the positions of hydrogen atoms. Neutrons are not diffracted by electrons, but are diffracted by atomic nuclei; accordingly, neutron scattering lengths of hydrogen and its isotopes are comparable to those of non-hydrogen atoms. Therefore, neutron crystallography can determine both of the locations and orientations of water molecules. This chapter describes the current status of neutron nucleic acid crystallographic research as well as the basic principles of neutron diffraction experiments performed on nucleic acid crystals: materials, crystallization, diffraction experiments, and structure determination. PMID:26227050

  18. Method for isolating nucleic acids

    Hurt, Jr., Richard Ashley; Elias, Dwayne A.

    2015-09-29

    The current disclosure provides methods and kits for isolating nucleic acid from an environmental sample. The current methods and compositions further provide methods for isolating nucleic acids by reducing adsorption of nucleic acids by charged ions and particles within an environmental sample. The methods of the current disclosure provide methods for isolating nucleic acids by releasing adsorbed nucleic acids from charged particles during the nucleic acid isolation process. The current disclosure facilitates the isolation of nucleic acids of sufficient quality and quantity to enable one of ordinary skill in the art to utilize or analyze the isolated nucleic acids for a wide variety of applications including, sequencing or species population analysis.

  19. Acidification and Acid Rain

    Norton, S. A.; Veselã½, J.

    2003-12-01

    Air pollution by acids has been known as a problem for centuries (Ducros, 1845; Smith, 1872; Camuffo, 1992; Brimblecombe, 1992). Only in the mid-1900s did it become clear that it was a problem for more than just industrially developed areas, and that precipitation quality can affect aquatic resources ( Gorham, 1955). The last three decades of the twentieth century saw tremendous progress in the documentation of the chemistry of the atmosphere, precipitation, and the systems impacted by acid atmospheric deposition. Chronic acidification of ecosystems results in chemical changes to soil and to surface waters and groundwater as a result of reduction of base cation supply or an increase in acid (H+) supply, or both. The most fundamental changes during chronic acidification are an increase in exchangeable H+ or Al3+ (aluminum) in soils, an increase in H+ activity (˜concentration) in water in contact with soil, and a decrease in alkalinity in waters draining watersheds. Water draining from the soil is acidified and has a lower pH (=-log [H+]). As systems acidify, their biotic community changes.Acidic surface waters occur in many parts of the world as a consequence of natural processes and also due to atmospheric deposition of strong acid (e.g., Canada, Jeffries et al. (1986); the United Kingdom, Evans and Monteith (2001); Sweden, Swedish Environmental Protection Board (1986); Finland, Forsius et al. (1990); Norway, Henriksen et al. (1988a); and the United States (USA), Brakke et al. (1988)). Concern over acidification in the temperate regions of the northern hemisphere has been driven by the potential for accelerating natural acidification by pollution of the atmosphere with acidic or acidifying compounds. Atmospheric pollution ( Figure 1) has resulted in an increased flux of acid to and through ecosystems. Depending on the ability of an ecosystem to neutralize the increased flux of acidity, acidification may increase only imperceptibly or be accelerated at a rate that

  20. Acid Rain, pH & Acidity: A Common Misinterpretation.

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  1. Amino acids in the sedimentary humic and fulvic acids

    Sardessai, S.

    Humic and fulvic acids isolated from a few sediment samples from Arabian Sea and Bay of Bengal were analysed for total hydrolysable amino acids concentration and their composition. The amono acids content of fulvic acids was higher than in the humic...

  2. Synthesis and anticonvulsant activity of novel bicyclic acidic amino acids

    Conti, Paola; De Amici, Marco; Joppolo Di Ventimiglia, Samuele;

    2003-01-01

    Bicyclic acidic amino acids (+/-)-6 and (+/-)-7, which are conformationally constrained homologues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested toward ionotropic and metabotropic glutamate receptor subtypes; both of them...

  3. EFFECT OF ACIDITY ON ACID-SENSITIVE UV CURING SYSTEM

    Qi-dao Chen; Bing Wu; Xiao-yin Hong

    1999-01-01

    By using diphenyliodonium salts with different counterions as photo acid generators (PAGs), the effect of acidity on ring-opening polymerization of epoxy monomers and polycondensation of polyol with hexamethoxymethyl melamine (HMMM) was studied. The result shows that the rate of ring-opening polymerization is evidently dependent on the acidity of the acid and strong photo-generated acid is required.However, there is a leveling effect in the polycondensation system; if the photo-generated acid is stronger than protonated HMMM, the acidity does not obviously affect the polycondensation rate.

  4. Determination of Sialic Acids by Acidic Ninhydrin Reaction

    Yao,Kenzabroh

    1987-12-01

    Full Text Available A new acidic ninhydrin method for determining free sialic acids is described. The method is based on the reaction of sialic acids with Gaitonde's acid ninhydrin reagent 2 which yields a stable color with an absorption maximum at 470 nm. The standard curve is linear in the range of 5 to 500 nmol of N-acetylneuraminic acid per 0.9 ml of reaction mixture. The reaction was specific only for sialic acids among the various sugars and sugar derivatives examined. Some interference of this method by cysteine, cystine and tryptophan was noted, although their absorption maxima differed from that of sialic acids. The interference by these amino acids was eliminated with the use of a small column of cation-exchange resin. The acidic ninhydrin method provides a simple and rapid method for the determination of free sialic acids in biological materials.

  5. Chemistry and electrochemistry in trifluoroacetic acid. Comparison with acetic acid

    As the trifluoroacetic acid is, with the acetic acid, one of most often used carboxylic acids as solvent, notably in organic chemistry, this research thesis addresses some relatively simple complexing and redox reactions to highlight the peculiar feature of this acid, and to explain its very much different behaviour with respect to acetic acid. The author develops the notion of acidity level in solvents of low dielectric constant. The second part addresses a specific solvent: BF3(CH3COOH)2. The boron trifluoride strengthens the acidity of acetic acid and modifies its chemical and physical-chemical properties. In the third part, the author compares solvent properties of CF3COOH and CH3COOH. Noticed differences explain why the trifluoroacetic acid is a more interesting reaction environment than acetic acid for reactions such as electrophilic substitutions or protein solubilisation

  6. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances

    Je Min Lee; Hyungjae Lee; SeokBeom Kang; Woo Jung Park

    2016-01-01

    Polyunsaturated fatty acids (PUFAs) are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human phys...

  7. Domoic Acid Epileptic Disease

    John S. Ramsdell

    2014-03-01

    Full Text Available Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis.

  8. A Demonstration of Acid Rain

    Fong, Man Wai

    2004-01-01

    A demonstration showing acid rain formation is described. Oxides of sulfur and nitrogen that result from the burning of fossil fuels are the major pollutants of acid rain. In this demonstration, SO[subscript 2] gas is produced by the burning of matches. An acid-base indicator will show that the dissolved gas turns an aqueous solution acidic.

  9. Biological properties of lipoic acid

    Anna Bilska; Lidia Włodek

    2002-01-01

    Lipoic acid is a prostetic group of H-protein of the glycine cleavage system and the dihydrolipoamide acyltransferases (E2) of the pyruvate, alpha-ketoglutarate and branched-chain alpha-keto acid dehydrogenase complexes. Lipoic acid and its reduced form, dihydrolipoic acid, reacts with oxygen reactive species. This paper reviews the beneficial effects in oxidative stress models or clinical conditions.

  10. Amino acid analysis.

    Crabb, J W; West, K A; Dodson, W S; Hulmes, J D

    2001-05-01

    Amino acid analysis (AAA) is one of the best methods to quantify peptides and proteins. Two general approaches to quantitative AAA exist, namely, classical postcolumn derivatization following ion-exchange chromatography and precolumn derivatization followed by reversed-phase HPLC (RP-HPLC). Excellent instrumentation and several specific methodologies are available for both approaches, and both have advantages and disadvantages. This unit focuses on picomole-level AAA of peptides and proteins using the most popular precolumn-derivatization method, namely, phenylthiocarbamyl amino acid analysis (PTC-AAA). It is directed primarily toward those interested in establishing the technology with a modest budget. PTC derivatization and analysis conditions are described, and support and alternate protocols describe additional techniques necessary or useful for most any AAA method--e.g., sample preparation, hydrolysis, instrument calibration, data interpretation, and analysis of difficult or unusual residues such as cysteine, tryptophan, phosphoamino acids, and hydroxyproline. PMID:18429107

  11. Halogenated fatty acids

    Mu, Huiling; Sundin, Peter; Wesén, Clas

    1997-01-01

    Halogenated fatty acids are the major contributors to organohalogen compounds in lipids of marine mammals, fish, and bivalves. For the initial characterization of these recently noticed compounds, a determination of the halogen concentration has usually been combined with some lipid isolation and...... separation method. This review covers separation by solid phase chromatography, gel permeation chromatography, and liquid-liquid extraction, followed by halogen determination. All studies performed according to this outline have indicated that the major organohalogen compounds are chlorinated fatty acids...... bound in different lipids. For the detection and identification of individual, halogenated fatty acid methyl esters (FAMEs) liberated from the lipids, gas chromatography (GC) has been employed together with detection methods such as electron capture detection, electrolytic conductivity detection (ELCD...

  12. [Nicotinic acid and nicotinamide].

    Kobayashi, M; Shimizu, S

    1999-10-01

    Nicotinic acid and nicotinamide are called niacin. They are the antipellagra vitamin essential to many animals for growth and health. In human being, niacin is believed necessary together with other vitamins for the prevention and cure of pellagra. Niacin is widely distributed in nature; appreciable amounts are found in liver, fish, yeast and cereal grains. Nicotinamide is a precursor of the coenzyme NAD and NADP. Some of the most understood metabolic processes that involve niacin are glycolysis, fatty acid synthesis and respiration. Niacin is also related to the following diseases: Hartnup disease; blue diaper syndrome; tryptophanuria; hydroxykynureninuria; xanthurenic aciduria; Huntington's disease. PMID:10540864

  13. Whither Acid Rain?

    Peter Brimblecombe

    2000-01-01

    Acid rain, the environmental cause célèbre of the 1980s seems to have vanished from popular conscience. By contrast, scientific research, despite funding difficulties, has continued to produce hundreds of research papers each year. Studies of acid rain taught much about precipitation chemistry, the behaviour of snow packs, long-range transport of pollutants and new issues in the biology of fish and forested ecosystems. There is now evidence of a shift away from research in precipitation and s...

  14. A very acid rocket

    Benoit Browaeys, D.

    1996-04-01

    The french rocket Ariane is the cause of environmental pollution. These effects are discussed in this article. Chloric acid and aluminium are in question: chloric acid is responsible of leaves necrosis and pulmonary diseases among the rats. For the man, the danger would be that drinking water could be contaminated by aluminium, which is neuro toxic with serious chronic effects. It is implicated in Alzheimer disease. But no studies has been made to search aluminium in drinking water of Sinnamary and Kourou. (N.C.). 8 refs., 2 figs.

  15. Ethylenediaminetetraacetic acid in endodontics.

    Mohammadi, Zahed; Shalavi, Sousan; Jafarzadeh, Hamid

    2013-09-01

    Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA. EDTA reacts with the calcium ions in dentine and forms soluble calcium chelates. A review of the literature and a discussion of the different indications and considerations for its usage are presented. PMID:24966721

  16. Whither Acid Rain?

    Peter Brimblecombe

    2000-01-01

    Full Text Available Acid rain, the environmental cause célèbre of the 1980s seems to have vanished from popular conscience. By contrast, scientific research, despite funding difficulties, has continued to produce hundreds of research papers each year. Studies of acid rain taught much about precipitation chemistry, the behaviour of snow packs, long-range transport of pollutants and new issues in the biology of fish and forested ecosystems. There is now evidence of a shift away from research in precipitation and sulfur chemistry, but an impressive theoretical base remains as a legacy.

  17. Boric acid concentration monitoring

    Boric acid concentration was measured by thermal neutron absorption in the study of the boric acid sorption and desorption curves on an anion exchange resin. Ra-Be 18.5 GBq and Am-Be 111 GBq sources and water as a moderator were used. The SNM 12 cylindrical corona detector with 10B placed in the middle of the measuring cell was used for neutron flux measurement. The HP 9600 E computer system was used for measured data collection and evaluation. (Ha)

  18. Polyunsaturated fatty acids and inflammation

    Calder Philip C

    2004-01-01

    The n-6 polyunsaturated fatty acid arachidonic acid gives rise to the eicosanoid family of inflammatory mediators (prostaglandins, leukotrienes and related metabolites) and through these regulates the activities of inflammatory cells, the production of cytokines and the various balances within the immune system. Fish oil and oily fish are good sources of long chain n-3 polyunsaturated fatty acids. Consumption of these fatty acids decreases the amount of arachidonic acid in cell membranes and ...

  19. TRIP6 antagonizes the recruitment of A20 and CYLD to TRAF6 to promote the LPA2 receptor-mediated TRAF6 activation

    Lin, Fang-Tsyr; Lin, Vivian Y; Lin, Victor TG; Lin, Weei-Chin

    2016-01-01

    The elevated lysophosphatidic acid signaling has been causally linked to cancer-associated inflammation and tumorigenesis through upregulation of nuclear factor-κB signaling. However, how this signaling event is regulated has not yet been fully understood. Here we demonstrate that TRIP6, an LPA2 receptor-interacting adaptor protein, functions as a positive regulator of nuclear factor-κB and JNK signaling through direct binding to and activation of the E3 ligase TRAF6. Upon lysophosphatidic acid stimulation, TRIP6 recruits TRAF6 to the LPA2 receptor and promotes lysophosphatidic acid-induced JNK and nuclear factor-κB activation in a TRAF6-dependent manner. TRIP6 antagonizes the recruitment of deubiquitinases A20 and CYLD to TRAF6, thus sustaining the E3 ligase activity of TRAF6 and augmenting lysophosphatidic acid-activated nuclear factor-κB signaling. In contrast, depletion of TRIP6 by TRIP6-specific shRNA or Cas9/sgRNA greatly enhances the association of TRAF6 with A20 and CYLD, and attenuates lysophosphatidic acid-induced muclear factor-κB and JNK/p38 activation in ovarian cancer cells. On the other hand, TRAF6 also regulates TRIP6 by facilitating its binding to nuclear factor-κB p65 and phosphorylation by c-Src. Together, TRIP6 cooperates with TRAF6 to regulate the LPA2 receptor signaling, which may ultimately contribute to chronic inflammation, apoptotic resistance and cell invasion.

  20. Acid Rain Investigations.

    Hugo, John C.

    1992-01-01

    Presents an activity in which students investigate the formation of solid ammonium chloride aerosol particles to help students better understand the concept of acid rain. Provides activity objectives, procedures, sample data, clean-up instructions, and questions and answers to help interpret the data. (MDH)

  1. Acid Rain Classroom Projects.

    Demchik, Michael J.

    2000-01-01

    Describes a curriculum plan in which students learn about acid rain through instructional media, research and class presentations, lab activities, simulations, design, and design implementation. Describes the simulation activity in detail and includes materials, procedures, instructions, examples, results, and discussion sections. (SAH)

  2. The Acid Rain Game.

    Rakow, Steven J.; Glenn, Allen

    1982-01-01

    Provides rationale for and description of an acid rain game (designed for two players), a problem-solving model for elementary students. Although complete instructions are provided, including a copy of the game board, the game is also available for Apple II microcomputers. Information for the computer program is available from the author.…

  3. The Acid Rain Debate.

    Oates-Bockenstedt, Catherine

    1997-01-01

    Details an activity designed to motivate students by incorporating science-related issues into a classroom debate. Includes "The Acid Rain Bill" and "Position Guides" for student roles as committee members, consumers, governors, industry owners, tourism professionals, senators, and debate directors. (DKM)

  4. Hyaluronic Acid Assays

    Itenov, Theis S; Kirkby, Nikolai S; Bestle, Morten H;

    2015-01-01

    BACKGROUD: Hyaluronic acid (HA) is proposed as a marker of functional liver capacity. The aim of the present study was to compare a new turbidimetric assay for measuring HA with the current standard method. METHODS: HA was measured by a particle-enhanced turbidimetric immunoassay (PETIA) and enzyme...

  5. Koetjapic acid chloroform hemisolvate

    Z. D. Nassar

    2010-06-01

    Full Text Available The asymmetric unit of the title compound, C30H46O4·0.5CHCl3, consists of one koetjapic acid [systematic name: (3R,4aR,4bS,7S,8S,10bS,12aS-7-(2-carboxyethyl-3,4b,7,10b,12a-pentamethyl-8-(prop-1-en-2-yl-1,2,3,4,4a,4b,5,6,7,8,9,10,10b,11,12,12a-hexadecahydrochrysene-3-carboxylic acid] molecule and one half-molecule of chloroform solvent, which is disordered about a twofold rotation axis. The symmetry-independent component is further disordered over two sites, with occupancies of 0.30 and 0.20. The koetjapic acid contains a fused four-ring system, A/B/C/D. The A/B, B/C and C/D junctions adopt E/trans/cis configurations, respectively. The conformation of ring A is intermediate between envelope and half-chair and ring B adopts an envelope conformation whereas rings C and D adopt chair conformations. A weak intramolecular C—H...O hydrogen bond is observed. The koetjapic acid molecules are linked into dimers by two pairs of intermolecular O—H...O hydrogen bonds. The dimers are stacked along the c axis.

  6. Lactic acid and lactates

    Schreurs, V.V.A.M.

    2010-01-01

    This review aims to integrate the present state of knowledge on lactate metabolism in human and mammalian physiology as far as it could be subject to nutritional interventions. An integrated view on the nutritional, metabolic and physiological aspects of lactic acid and lactates might open a perspec

  7. Acid dip for dosemeter

    Background signal in a PTFE based dosemeter caused by impurities in the PTFE and in the active component such as lithium fluoride is substantially reduced by treating the dosemeter with acid. The optimum treatment involves use of hydrofluoric acid at room temperature for approximately one minute, followed by thorough washing with methanol, and finally drying. This treatment is best applied after the original manufacture of the dosemeters. It may also be applied to existing dosemeters after they have been in use for some time. The treatment produces a permanent effect in reducing both the light induced signal and the non-light induced signal. The process may be applied to all types of dosemeter manufactured from PTFE or other plastics or resins which are able to resist brief exposure to acid. The treatment works particularly well with dosemeters based on PTFE and lithium fluoride. It is also applicable to dosemeters based on calcium sulphate, lithium borate and magnesium borate. Acids which may be used include hydrofluoric, hydrochloric, nitric, phosphoric and sulphuric. (author)

  8. Accidents with sulfuric acid

    Rajković Miloš B.

    2006-01-01

    Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

  9. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  10. The biosynthesis of erucic acid in developing embryos of Brassica rapus

    The prevailing hypothesis on the biosynthesis of erucic acid in developing seeds is that oleic acid, produced in the plastid, is activated to oleoyl-coenzyme A (CoA) for malonyl-CoA-dependent elongation to erucic acid in the cytosol. Several in vivo-labeling experiments designed to probe and extend this hypothesis are reported here. To examine whether newly synthesized oleic acid is directly elongated to erucic acid in developing seeds of Brassica rapa L., embryos were labeled with [14C]acetate, and the ratio of radioactivity of carbon atoms C-5 to C-22 (de novo fatty acid synthesis portion) to carbon atoms C-1 to C-4 (elongated portion) of erucic acid was monitored with time. If newly synthesized 18:1 (oleate) immediately becomes a substrate for elongation to erucic acid, this ratio would be expected to remain constant with incubation time. However, if erucic acid is produced from a pool of preexisting oleic acid, the ratio of 14C in the 4 elongation carbons to 14C in the methyl-terminal 18 carbons would be expected to decrease with time. This labeling ratio decreased with time and, therefore, suggests the existence of an intermediate pool of 18:1, which contributes at least part of the oleoyl precursor for the production of erucic acid. The addition of 2-[(3-chloro-5-(trifluromethyl)-2-pyridinyl) oxyphenoxy]propanoic acid, which inhibits the homodimeric acetyl-CoA carboxylase, severely inhibited the synthesis of [14C]erucic acid, indicating that essentially all malonyl-CoA for elongation of 18:1 to erucate was produced by homodimeric acetyl-CoA carboxylase. Both light and 2-[(3-chloro-5(trifluromethyl)-2-pyridinyl) oxyphenoxy]-propanoic acid increased the accumulation of [14C]18:1 and the parallel accumulation of [14C]phosphatidylcholine. Taken together, these results show an additional level of complexity in the biosynthesis of erucic acid

  11. Origin of fatty acids

    The appearance of fatty acids and membranes is one of the most important events of the prebiotic world because genesis of life required the compartmentalization of molecules. Membranes allowed cells to become enriched with molecules relevant for their evolution and gave rise to gradients convertible into energy. By virtue of their hydrophobic/hydrophilic interface, membranes developed certain enzymatic activities impossible in the aqueous phase. A prebiotic cell is an energy unit but it is also an information unit. It has a past, a present and a future. The biochemistry of fatty acids involves acetylCoA, malonylCoA and an enzyme, acyl synthetase, which joins both molecules. After substitution of the acetyl group in place of the carboxyl group of malonyl derivatives, the chain is reduced and dehydrated to crotonyl derivatives. These molecules can again react with malonylCoA to form unsaturated chain; they can also undergo a new reduction step to form butyryl derivatives which can react with malonylCoA to form a longer aliphatic chain. The formation of malonylCoA consumes ATP. The reduction step needs NADPH and proton. Dehydration requires structural information because the reduction product is chiral (D configuration). It is unlikely that these steps were possible in a prebiotic environment. Thus we have to understand how fatty acids could appear in the prebiotic era. This hypothesis about the origin of fatty acids is based on the chemistry of sulfonium ylides and sulfonium salts. The most well-known among these molecules are S-melthyl-methionine and S-adenosyl methionine. The simplest sulfonium cation is the trimethylsulfonium cation. Chemists have evidence that these products can produce olefin when they are heated or flashed with UV light in some conditions. I suggest that these volatile products can allow the formation of fatty acids chains in atmospheric phase with UV and temperature using methanol as starting material. Different synthetic pathways will be

  12. Photostabilization of ascorbic acid with citric acid, tartaric acid and boric acid in cream formulations.

    Ahmad, I; Ali Sheraz, M; Ahmed, S; Shad, Z; Vaid, F H M

    2012-06-01

    This study involves the evaluation of the effect of certain stabilizers, that is, citric acid (CT), tartaric acid (TA) and boric acid (BA) on the degradation of ascorbic acid (AH(2) ) in oil-in-water cream formulations exposed to the UV light and stored in the dark. The apparent first-order rate constants (0.34-0.95 × 10(-3) min(-1) in light, 0.38-1.24 × 10(-2) day(-1) in dark) for the degradation reactions in the presence of the stabilizers have been determined. These rate constants have been used to derive the second-order rate constants (0.26-1.45 × 10(-2) M(-1) min(-1) in light, 3.75-8.50 × 10(-3) M(-1) day(-1) in dark) for the interaction of AH(2) and the individual stabilizers. These stabilizers are effective in causing the inhibition of the rate of degradation of AH(2) both in the light and in the dark. The inhibitory effect of the stabilizers is in the order of CT > TA > BA. The rate of degradation of AH(2) in the presence of these stabilizers in the light is about 120 times higher than that in the dark. This could be explained on the basis of the deactivation of AH(2) -excited triplet state by CT and TA and by the inhibition of AH(2) degradation through complex formation with BA. AH(2) leads to the formation of dehydroascorbic acid (A) by chemical and photooxidation in cream formulations. PMID:22296174

  13. Arterial Blood Carbonic Acid Inversely Determines Lactic and Organic Acids

    Aiken, Christopher Geoffrey Alexander

    2013-01-01

    Objective: To establish that arterial blood carbonic acid varies inversely with lactic acid in accordance with bicarbonate exchanging for lactate across cell membranes through the anion exchange mechanism to maintain the Gibbs-Donnan equilibrium.

  14. Boswellic acid inhibits expression of acid sphingomyelinase in intestinal cells

    Duan Rui-Dong

    2009-12-01

    Full Text Available Abstract Background Boswellic acid is a type of triterpenoids with antiinflammatory and antiproliferative properties. Sphingomyelin metabolism generates multiple lipid signals affecting cell proliferation, inflammation, and apoptosis. Upregulation of acid sphingomyelinase (SMase has been found in several inflammation-related diseases such as inflammatory bowel diseases, atherosclerosis, and diabetes. Methods The present study is to examine the effect of 3-acetyl-11-keto-β-boswellic acids (AKBA, a potent boswellic acid, on acid SMase activity and expression in intestinal cells. Both transformed Caco-2 cells and non-transformed Int407 cells were incubated with AKBA. After incubation, the change of acid SMase activity was assayed biochemically, the enzyme protein was examined by Western blot, and acid SMase mRNA was quantified by qPCR. Results We found that AKBA decreased acid SMase activity in both intestinal cell lines in dose and time dependent manners without affecting the secretion of the enzyme to the cell culture medium. The effect of AKBA was more effective in the fetal bovine serum-free culture medium. Among different types of boswellic acid, AKBA was the most potent one. The inhibitory effect on acid SMase activity occurred only in the intact cells but not in cell-free extract in the test tubes. At low concentration, AKBA only decreased the acid SMase activity but not the quantity of the enzyme protein. However, at high concentration, AKBA decreased both the mass of acid SMase protein and the mRNA levels of acid SMase in the cells, as demonstrated by Western blot and qPCR, respectively. Under the concentrations decreasing acid SMase activity, AKBA significantly inhibited cell proliferation. Conclusion We identified a novel inhibitory effect of boswellic acids on acid SMase expression, which may have implications in human diseases and health.

  15. [Lipid synthesis by an acidic acid tolerant Rhodotorula glutinis].

    Lin, Zhangnan; Liu, Hongjuan; Zhang, Jian'an; Wang, Gehua

    2016-03-01

    Acetic acid, as a main by-product generated in the pretreatment process of lignocellulose hydrolysis, significantly affects cell growth and lipid synthesis of oleaginous microorganisms. Therefore, we studied the tolerance of Rhodotorula glutinis to acetic acid and its lipid synthesis from substrate containing acetic acid. In the mixed sugar medium containing 6 g/L glucose and 44 g/L xylose, and supplemented with acetic acid, the cell growth was not:inhibited when the acetic acid concentration was below 10 g/L. Compared with the control, the biomass, lipid concentration and lipid content of R. glutinis increased 21.5%, 171% and 122% respectively when acetic acid concentration was 10 g/L. Furthermore, R. glutinis could accumulate lipid with acetate as the sole carbon source. Lipid concentration and lipid yield reached 3.20 g/L and 13% respectively with the initial acetic acid concentration of 25 g/L. The lipid composition was analyzed by gas chromatograph. The main composition of lipid produced with acetic acid was palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid, including 40.9% saturated fatty acids and 59.1% unsaturated fatty acids. The lipid composition was similar to that of plant oil, indicating that lipid from oleaginous yeast R. glutinis had potential as the feedstock of biodiesel production. These results demonstrated that a certain concentration of acetic acid need not to be removed in the detoxification process when using lignocelluloses hydrolysate to produce microbial lipid by R. glutinis. PMID:27349116

  16. Augmenting acid with affective details to assess credibility

    Roland Fleck

    2011-07-01

    Full Text Available There is a need within the criminal justice systems of many countries to create a valid and applicable system of investigative interviewing and credibility assessment. The present study assesses the general validity one such system, called Assessment Criteria Indicative of Deception (ACID. ACID comprises interviewing strategies that facilitate the detection of deception and content criteria that highlight differences in verbal behavior. Sixty university undergraduates performed a staged theft under time pressure and with incentives designed to increase external validity. The participants were interviewed and assessed using the ACID procedure. Half of them were instructed to answer honestly and the other half to deny his/her participation in the theft. Results showed that honest statements were longer, more vividly detailed, and more spontaneously structured than deceptive statements. Also, the addition of affective details as a dependent measure significantly improved the ACID system. Overall, 48 of 60 statements were accurately classified (26 of 30 honest statements and 22 of 30 deceptive statements. The ACID procedure was effective and benefited from the addition of affective details. The strengths and weaknesses of this study are discussed in light of basic research into deception and potential forensic application.

  17. Acetic acid extraction from aqueous solutions using fatty acids

    IJmker, H.M.; Gramblicka, M.; Kersten, S.R.A.; Ham, van der A.G.J.; Schuur, B.

    2014-01-01

    A major challenge for production of acetic acid via bio-based routes is cost-effective concentration and purification of the acetic acid from the aqueous solutions, for which liquid–liquid extraction is a possible method. A main challenge in extraction of acetic acid from dilute aqueous solutions is

  18. College Chemistry Students' Mental Models of Acids and Acid Strength

    McClary, LaKeisha; Talanquer, Vicente

    2011-01-01

    The central goal of this study was to characterize the mental models of acids and acid strength expressed by advanced college chemistry students when engaged in prediction, explanation, and justification tasks that asked them to rank chemical compounds based on their relative acid strength. For that purpose we completed a qualitative research…

  19. Jmjd2C increases MyoD transcriptional activity through inhibiting G9a-dependent MyoD degradation.

    Jung, Eun-Shil; Sim, Ye-Ji; Jeong, Hoe-Su; Kim, Su-Jin; Yun, Ye-Jin; Song, Joo-Hoon; Jeon, Su-Hee; Choe, Chungyoul; Park, Kyung-Tae; Kim, Chang-Hoon; Kim, Kye-Seong

    2015-08-01

    Skeletal muscle cell differentiation requires a family of proteins called myogenic regulatory factors (MRFs) to which MyoD belongs. The activity of MyoD is under epigenetic regulation, however, the molecular mechanism by which histone KMTs and KDMs regulate MyoD transcriptional activity through methylation remains to be determined. Here we provide evidence for a unique regulatory mechanism of MyoD transcriptional activity through demethylation by Jmjd2C demethylase whose level increases during muscle differentiation. G9a decreases MyoD stability via methylation-dependent MyoD ubiquitination. Jmjd2C directly associates with MyoD in vitro and in vivo to demethylate and stabilize MyoD. The hypo-methylated MyoD due to Jmjd2C is significantly more stable than hyper-methylated MyoD by G9a. Cul4/Ddb1/Dcaf1 pathway is essential for the G9a-mediated MyoD degradation in myoblasts. By the stabilization of MyoD, Jmjd2C increases myogenic conversion of mouse embryonic fibroblasts and MyoD transcriptional activity with erasing repressive H3K9me3 level at the promoter of MyoD target genes. Collectively, Jmjd2C increases MyoD transcriptional activity to facilitate skeletal muscle differentiation by increasing MyoD stability through inhibiting G9a-dependent MyoD degradation. PMID:26149774

  20. Group boundary permeability moderates the effect of a dependency meta-stereotype on help-seeking behaviour.

    Zhang, Lange; Kou, Yu; Zhao, Yunlong; Fu, Xinyuan

    2016-08-01

    Previous studies have found that when low-status group members are aware that their in-group is stereotyped as dependent by a specific out-group (i.e. a dependency meta-stereotype is salient), they are reluctant to seek help from the high-status out-group to avoid confirming the negative meta-stereotype. However, it is unclear whether low-status group members would seek more help in the context of a salient dependency meta-stereotype when there is low (vs. high) group boundary permeability. Therefore, we conducted two experiments to examine the moderating effect of permeability on meta-stereotype confirmation with a real group. In study 1, we manipulated the salience of the dependency meta-stereotype, measured participants' perceived permeability and examined their help-seeking behaviour in a real-world task. Participants who perceived low permeability sought more help when the meta-stereotype was salient (vs. not salient), whereas participants who perceived high permeability sought the same amount of help across conditions. In study 2, we manipulated the permeability levels and measured the dependency meta-stereotype. Participants who endorsed a high-dependency meta-stereotype sought more help than participants who endorsed a low-dependency meta-stereotype; this effect was particularly strong in the low-permeability condition. The implications of these results for social mobility and intergroup helping are discussed. PMID:25885332

  1. Compression regulates gene expression of chondrocytes through HDAC4 nuclear relocation via PP2A-dependent HDAC4 dephosphorylation.

    Chen, Chongwei; Wei, Xiaochun; Wang, Shaowei; Jiao, Qiang; Zhang, Yang; Du, Guoqing; Wang, Xiaohu; Wei, Fangyuan; Zhang, Jianzhong; Wei, Lei

    2016-07-01

    Biomechanics plays a critical role in the modulation of chondrocyte function. The mechanisms by which mechanical loading is transduced into intracellular signals that regulate chondrocyte gene expression remain largely unknown. Histone deacetylase 4 (HDAC4) is specifically expressed in chondrocytes. Mice lacking HDAC4 display chondrocyte hypertrophy, ectopic and premature ossification, and die early during the perinatal period. HDAC4 has a remarkable ability to translocate between the cell's cytoplasm and nucleus. It has been established that subcellular relocation of HDAC4 plays a critical role in chondrocyte differentiation and proliferation. However, it remains unclear whether subcellular relocation of HDAC4 in chondrocytes can be induced by mechanical loading. In this study, we first report that compressive loading induces HDAC4 relocation from the cytoplasm to the nucleus of chondrocytes via stimulation of Ser/Thr-phosphoprotein phosphatases 2A (PP2A) activity, which results in dephosphorylation of HDAC4. Dephosphorylated HDAC4 relocates to the nucleus to achieve transcriptional repression of Runx2 and regulates chondrocyte gene expression in response to compression. Our results elucidate the mechanism by which mechanical compression regulates chondrocyte gene expression through HDAC4 relocation from the cell's cytoplasm to the nucleus via PP2A-dependent HDAC4 dephosphorylation. PMID:27106144

  2. N-(3-Methylphenylsuccinamic acid

    B. Thimme Gowda

    2010-02-01

    Full Text Available In the crystal structure of the title compound, C11H13NO3, the conformations of the N—H and C=O bonds in the amide segment are anti to each other, and that of the amide H atom is anti to the meta-methyl group in the benzene ring. Furthermore, the conformations of the amide oxygen and the carbonyl O atom of the acid segment are also anti to the adjacent –CH2 groups. The C=O and O—H bonds of the acid group are syn to each other. In the crystal, the molecules are packed into infinite chains through intermolecular N—H...O and O—H...O hydrogen bonds.

  3. [Progress in glucaric acid].

    Qiu, Yuying; Fang, Fang; Du, Guocheng; Chen, Jian

    2015-04-01

    Glucaric acid (GA) is derived from glucose and commonly used in chemical industry. It is also considered as one of the "Top value-added chemicals from biomass" as carbohydrate monomers to produce various synthetic polymers and bioenergy. The demand for GA in food manufacture is increasing. GA has also attracted public attentions due to its therapeutic uses such as regulating hormones, increasing the immune function and reducing the risks of cancers. Currently GA is produced by chemical oxidation. Research on production of GA via microbial synthesis is still at preliminary stage. We reviewed the advances of glucaric acid applications, preparation and quantification methods. The prospects on production of GA by microbial fermentation were also discussed. PMID:26380405

  4. Studies on terreic acid.

    Yamamoto, H; Moriyama, K; Jinnouchi, H; Yagishita, K

    1980-03-01

    It was found that Aspergillus sp. No. Y-8980 which was isolated from a soil sample collected at Yoron Island in Kagoshima Prefecture belonged to Aspergillus terreus group by morphological observation. The active substance produced by the strain was obtained with a high yield in sucrose-yeast extract medium and extracted by chloroform, ethyl acetate and n-butanol at pH 2.4 approximately 2.6 from the culture broth. The substance was crystallized from chloroform and ethyl acetate after charcoal treatment of the crude crystal. From various physico-chemical properties, it was found that the substance was identical to terreic acid. Terreic acid showed MICs of 25 approximately 100 mcg/ml, 12.5 mcg/ml and 50 mcg/ml against Gram-positive and Gram-negative bacteria, Xanthomonas oryzae and Xanthomonas citri, respectively, but it did not control Pseudomonas, fungi and yeast. The LD50 was 75 mg/kg i.p. and i.v. in mice. With regards to the anti-tumor effect, the morphological degeneration on HeLa cells (human carcinoma cells) was observed in the concentrations of more than 6.25 mcg/ml of terreic acid. An increase of body weight of mice caused by Ehrlich ascites carcinoma cells was not definitely observed by the daily administration of 150 mcg of terreic acid per mouse for 8 consecutive days. Above showed the enough survival effect in dd mice implanted with Ehrlich ascites carcinoma cells, and the effect also was demonstrated by anatomies of mice. PMID:7190624

  5. Electrochemistry of nucleic acids

    Paleček, Emil; Bartošík, Martin

    2012-01-01

    Roč. 112, č. 6 (2012), s. 3427-3481. ISSN 0009-2665 R&D Projects: GA ČR(CZ) GAP301/11/2055; GA MŠk(CZ) ME09038; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : nucleic acids electrochemistry * DNA biosensors * DNA damage Subject RIV: BO - Biophysics Impact factor: 41.298, year: 2012

  6. Bile acids for viral hepatitis

    Chen, Weikeng; Liu, J; Gluud, C

    2007-01-01

    Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness.......Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness....

  7. Pantothenic acid (Vitamin B5)

    ... niacinamide), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B12 (cyanocobalamin), and folic acid. However, some products do ... for dandruff, depression, diabetic nerve pain, enhancing immune function, improving athletic performance, tongue infections, gray hair, headache, ...

  8. ACID ROCK DRAINAGE

    Anca Ionce

    2010-10-01

    Full Text Available Acid rock drainage (ARD is an particularly important aspect for the evaluation of the decantation ponds’ safety, and which has been only once taken into consideration at the Tarnicioara decantation pond, year 2002, as a consequence of the apparition of a strong seepage on the deposit’s dump, that has chemically de-purified the water from the river Brateasa. We have observed ARD, which implies the release of acid solutions from the mining sterile deposits, from the underground mining works and from the quarries, in the following tailings dams: Tarnicioara, Valea Strajii, Poarta Veche- which served Tarniţa Preparation Enterprise and in the Dealu Negru and Paraul Cailor ponds- which, at their time served Fundu Moldovei Preparation Enterprise, both during the period of their functioning and the period after their closure. For the decantation pond Dumitrelu which served the Calimani preparation enterprise, acid seepages from the deposit were mentioned in a study made by SC ICPM SA Baia Mare in 1993. Subsequently to the closure of the objective such seepage did not take place anymore. Instead, by raining, there is a frequent plant sterile dragging from the contour retaining wall down to the trouble pond, situated upstream.

  9. Study of the A-dependence of the deep inelastic scattering of leptons and its implications for understanding of the EMC effect

    It is suggested to determine A dependence of distortions of the nucleon structure function summing up the distortions found in some interval. All the available data evidence for the saturation of the distortion magnitude with A rising

  10. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    NEENA GARG

    2015-01-01

    Lactic acid bacteria (LAB) is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LA...

  11. Retinoic acid and cancer treatment

    Chen, Mei-Chih; Hsu, Shih-Lan; Lin, Ho; Yang, Tsung-Ying

    2014-01-01

    Retinoic acid which belongs to the retinoid class of chemical compounds is an important metabolite of vitamin A in diets. It is currently understood that retinoic acid plays important roles in cell development and differentiation as well as cancer treatment. Lung, prostate, breast, ovarian, bladder, oral, and skin cancers have been demonstrated to be suppressed by retinoic acid. Our results also show that low doses and high doses of retinoic acid may respectively cause cell cycle arrest and a...

  12. Biological properties of lipoic acid

    Anna Bilska

    2002-06-01

    Full Text Available Lipoic acid is a prostetic group of H-protein of the glycine cleavage system and the dihydrolipoamide acyltransferases (E2 of the pyruvate, alpha-ketoglutarate and branched-chain alpha-keto acid dehydrogenase complexes. Lipoic acid and its reduced form, dihydrolipoic acid, reacts with oxygen reactive species. This paper reviews the beneficial effects in oxidative stress models or clinical conditions.

  13. Sedimentation of sulfuric acid in acid tars from current production

    Denisova, T.L.; Frolov, A.F.; Aminov, A.N.; Novosel' tsev, S.P.

    1987-09-01

    Acid tars obtained in treating T-750, KhF-12, and I-8A oils were investigated for purposes of recovering sulfuric acid and asphalt binders from the compositions and of determining the effects of storage time on the recovery. The consumption and sedimentation levels of sulfuric acid during storage for different periods and at different temperatures were assessed. The characteristics of an asphalt binder obtained by neutralizing acid tar with a paste consisting of asphalts from deasphalting operations and slaked lime, followed by oxidation of the mixture with atmospheric air, were determined. The sulfuric acid recovered in the settling process could be burned in order to purify it of organic contaminants.

  14. Acids and bases solvent effects on acid-base strenght

    Cox, Brian G

    2013-01-01

    Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

  15. An Umbrella for Acid Rain.

    Randal, Judith

    1979-01-01

    The Environmental Protection Agency has awarded several grants to study effects of and possible solutions to the problem of "acid rain"; pollution from atmospheric nitric and sulfuric acids. The research program is administered through North Carolina State University at Raleigh and will focus on biological effects of acid rain. (JMF)

  16. Excitatory amino acid receptor antagonists

    Johansen, T N; Frydenvang, Karla Andrea; Ebert, B;

    1997-01-01

    We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation...

  17. Pantothenic acid biosynthesis in zymomonas

    Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

    2014-07-01

    Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.

  18. Acid Rain Limits Global Warming

    Will Knight; 张林玲

    2004-01-01

    @@ Acid rain restricts global warming by reducing methane① emissions from natural wetland areas, suggests a global climate study. Acid rain is the result of industrial pollution,which causes rainwater to carry small quantities of acidic compoumds② such as sulphuric and nitric acid③. Contaminated rainwater can upset rivers and lakes, killing fish and other organisms and also damage plants, trees and buildings.

  19. Self-neutralizing well acidizing

    Richardson, E.A.; Scheuerman, R.F.

    1974-07-30

    A process for acidizing a subterranean region by contacting it with an acidic solution is improved by dissolving in the solution a pH-increasing reactant that subsequently adjusts the pH of the solution to a selected relatively neutral value. Urea is an example of the acid neutralizer. (10 claims)

  20. Cyp1a-dependent activation of xenobiotics in endothelial linings of the chorioallantoic membrane (CAM) in birds

    Metabolic activation of the heterocyclic amine 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 7-ethoxyresorufin O-deethylase (EROD) activity were examined in the chorioallantoic membrane (CAM) of 15-day-old chicken and 18-day-old eider duck embryos. The embryos were pretreated with an Ah receptor agonist, i.e. β-naphthoflavone (BNF) or 3,3',4,4',5-pentachlorobiphenyl (PCB 126), or vehicle in ovo. BNF and PCB 126 induced EROD activity and covalent binding of [3H]Trp-P-1 seven- to tenfold in the CAM of chicken embryos. In the CAM of eider duck embryos, which are known to be nonresponsive to coplanar PCBs, PCB 126 treatment had no effect on EROD activity or covalent binding of [3H]Trp-P-1 whereas BNF treatment increased these activities five- and threefold, respectively. Light microscopic autoradiography was used to identify the cellular localization of covalent binding of [3H]Trp-P-1 in the CAM. Preferential binding was observed in endothelial cells in intraepithelial capillaries in the chorionic epithelium and in blood vessels in the mesenchymal layer. The addition of the CYP1A inhibitor ellipticine abolished the covalent binding of [3H]Trp-P-1 in the CAM of BNF- and PCB 126-treated chicken and eider duck embryos. The results suggest that CYP1A-dependent metabolic activity can be induced in blood vessel endothelia in the CAM of bird embryos following exposure to Ah receptor agonists and that the CAM may be a target tissue for CYP1A-activated environmental pollutants. Furthermore, the highly vascularized CAM could be used as a model for studies of Ah receptor-mediated alterations in the vasculature. (orig.)

  1. Ionic liquid supported acid-catalysed esterification of lauric acid

    Ionic Liquid (IL) based on 1-n-butyl-3-methylimidazolium bis(trifluoro methylsulfonyl)imide (BMI.NTf2) under acidic condition was used as catalyst for the esterification reaction of fatty acid. Various acids namely sulphuric acid, perchloric acid, p-toulene sulphonic acid and various chloride salts such as zinc chloride (ZnCl2) and iron (III) chloride (FeCl3) immobilized in ionic liquid BMI.NTf2 gave acidic ILs. These acidic ILs were tested as catalysts for esterification reactions. Esterification of alcohol (methanol) with fatty acid (lauric acid) using ionic liquid BMI.NTf2 combined with H2SO4 (BMI.NTf2(H2SO4)) gave high activity (>85 %) and selectivity (100 %) observed over a period of 2 hours reaction with reaction temperature 70 degree Celsius. The ester became easily separated due to IL forming biphasic with product after the reaction where ester accumulated as the upper phase and IL with water produced after reaction at lower phase. Catalytic activities comparison also be studied between acidic ionic liquid BMI.NTf2 with acidic ionic liquid ChCl.2ZnCl2 and conventional acid catalyst. These ILs were characterised by using FTIR, NMR and TGA. Results from FTIR were showed no significant difference between ILs with ILs in acidic condition. The TGA curve show BMI.NTf2 thermals decomposition is ≥400 degree Celsius but when BMI.NTf2 combination with H2SO4, TGA curve show weight loss increase and becomes unstable. The advantages of ILs as catalyst are clean process and green chemistry due to its behaviour such as non-volatile, no loss of solvent through evaporation and reduced environmentally impact. This ILs-catalyst system can be recycle for further reaction. (author)

  2. Invasive cleavage of nucleic acids

    Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)

    2002-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  3. Invasive cleavage of nucleic acids

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann D.; Dahlberg, James E.

    1999-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  4. Tested Demonstrations: Color Oscillations in the Formic Acid-Nitric Acid-Sulfuric Acid System.

    Raw, C. J. G.; And Others

    1983-01-01

    Presented are procedures for demonstrating the production of color oscillations when nitric acid is added to a formic acid/concentrated sulfuric acid mixture. Because of safety considerations, "Super-8" home movie of the color changes was found to be satisfactory for demonstration purposes. (JN)

  5. Polyunsaturated fatty acids and inflammation

    Calder Philip C.

    2004-01-01

    Full Text Available The n-6 polyunsaturated fatty acid arachidonic acid gives rise to the eicosanoid family of inflammatory mediators (prostaglandins, leukotrienes and related metabolites and through these regulates the activities of inflammatory cells, the production of cytokines and the various balances within the immune system. Fish oil and oily fish are good sources of long chain n-3 polyunsaturated fatty acids. Consumption of these fatty acids decreases the amount of arachidonic acid in cell membranes and so available for eicosanoid production. Thus, n-3 polyunsaturated fatty acids act as arachidonic acid antagonists. Components of both natural and acquired immunity, including the production of key inflammatory cytokines, can be affected by n-3 polyunsaturated fatty acids. Although some of the effects of n-3 fatty acids may be brought about by modulation of the amount and types of eicosanoids made, it is possible that these fatty acids might elicit some of their effects by eicosanoid-independent mechanisms. Such n-3 fatty acid-induced effects may be of use as a therapy for acute and chronic inflammation, and for disorders that involve an inappropriately-activated immune response.

  6. Waste acid detoxification and reclamation

    Economically feasible processes that reduce the volume, quantity, and toxicity of metal-bearing waste acids by reclaiming, reusing, and recycling spent acids and metal salts are being developed and demonstrated. The acids used in the demonstrations are generated during metal-finishing operations used in nuclear fuel fabrication; HF-HNO3, HNO3, and HNO3-H2SO4 wastes result from Zr etching, Cu stripping, and chemical milling of U. At discharge, wastes contain high concentrations of acid and one major metal impurity. The waste minimization process used to reclaim acid from these three streams incorporates three processes for acid regeneration and reclamation. Normally, HNO3 remains in the bottoms when an aqueous acid solution is distilled; however, in the presence of H2SO4, HNO3 will distill to the overhead stream. In this process, nitrates and fluorides present as free acid and metal salts can be reclaimed as acid for recycle to the metal-finishing processes. Uranium present in the chemical milling solution can be economically recovered from distillation bottoms and refined. Using acid distillation, the volume of chemical milling solution discharged as waste can be reduced by as much as 60% depending on the H2SO4 concentration. A payback period of 2.2 years has been estimated for this process. The development and demonstration of precipitation and distillation processes for detoxification and reclamation of waste acid is supported by the US Department of Energy's Hazardous Waste Remedial Actions Program (HAZWRAP)

  7. Labeled bile acids

    A general short procedure for the introduction of 13C to the side chain of bile acids is described. Suitable (Z)-pregn-17(20)-enes are key intermediates, while the isotope is introduced by an ene reaction with [1,2,3-13C3]-methyl propiolate. For the labeling with tritium, the unlabeled product of the ene synthesis, a Δsup(5,16,22)-triene was saturated selectively at 16,17 and 22,23 with tritium gas. (author)

  8. N-(4-Isocyanophenylsuccinamic acid

    Lauren E. Burnham

    2012-07-01

    Full Text Available In the crystal structure of the title compound, C11H10N2O3, inversion-related molecules are connected by pairs of O—H...O hydrogen bonds. With the exception of the atoms in the carboxylic acid group, the non-H atoms are roughly coplanar with a maximum deviation from the mean plane of 0.270 (1 Å for the C atom to which the carboxylic group is attached. The C atom of the carboxylic group lies 1.730 (2 Å from the mean plane.

  9. Nucleic Acid Vaccines

    LU Shan

    2004-01-01

    @@ Anew method of immunization was discovered in the early 1990s. Several research groups independently demonstrated that direct inoculation of DNA plasmids coding for a specific protein antigen could elicit immune responses against that antigen[1-4].Since in theory the mRNA molecules also have the potential to be translated into the protein antigen, this vaccination approach was officially named by WHO as the nucleic acid vaccination even though the term DNA vaccine has been used more commonly in the literature. This novel approach is considered the fourth generation of vaccines after live attenuated vaccines, killed or inactivated vaccines and recombinant protein based subunit vaccines.

  10. Kinetics and Mechanism of Oxidation of Phenyl Acetic Acid and Dl-Mandelic Acid by Permanganate in Acid Medium

    B. Syama Sundar; P.S.Radhakrishna murti

    2014-01-01

    Kinetics of oxidation of phenyl acetic acid and DL- Mandelic acid by potassium permanganate in aqueous acetic acid and perchloric acid mixture reveals that the kinetic orders are first order in oxidant, first order in H+ and zero order in substrate for phenyl acetic acid. DL-Mandelic acid exhibits first order in oxidant and zero order in substrate. The results are rationalised by a mechanism involving intermediate formation of mandelic acid in case of Phenyl acetic acid and ester formation wi...

  11. Cryoprotection from lipoteichoic acid

    Rice, Charles V.; Middaugh, Amy; Wickham, Jason R.; Friedline, Anthony; Thomas, Kieth J.; Johnson, Karen; Zachariah, Malcolm; Garimella, Ravindranth

    2012-10-01

    Numerous chemical additives lower the freezing point of water, but life at sub-zero temperatures is sustained by a limited number of biological cryoprotectants. Antifreeze proteins in fish, plants, and insects provide protection to a few degrees below freezing. Microbes have been found to survive at even lower temperatures, and with a few exceptions, antifreeze proteins are missing. Survival has been attributed to external factors, such as the high salt concentration of brine veins and adhesion to particulates or ice crystal defects. We have discovered an endogenous cryoprotectant in the cell wall of bacteria, lipoteichoic acid biopolymers. Adding 1% LTA to bacteria cultures immediately prior to freezing provides 50% survival rate, similar to the results obtained with 1% glycerol. In the absence of an additive, bacterial survival is negligible as measured with the resazurin cell viability assay. The mode of action for LTA cryoprotection is unknown. With a molecular weight of 3-5 kDa, it is unlikely to enter the cell cytoplasm. Our observations suggest that teichoic acids could provide a shell of liquid water around biofilms and planktonic bacteria, removing the need for brine veins to prevent bacterial freezing.

  12. Growth of nitric acid hydrates on thin sulfuric acid films

    Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

    1994-05-01

    Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1 - 3 × 10-4 Torr H2O and 1 - 2.5 × 10-6 Torr HNO3) and subjected to cooling and heating cycles. FTIR spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

  13. Growth of nitric acid hydrates on thin sulfuric acid films

    Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

    1994-01-01

    Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1-3 x 10(exp -4) Torr H2O and 1-2.5 x 10(exp -6) Torr HNO3) and subjected to cooling and heating cycles. Fourier Transform Infrared (FTIR) spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

  14. Caro's acid - its introduction to uranium acid leaching in Australia

    After extensive testing and plant trials to establish the benefits of Caro's acid (H2SO5) as an alternative oxidant, Queensland Mines Limited decided to replace pyrolusite with Caro's acid in its acid leach uranium treatment plant at Nabarlek. The decision was based on the reagent savings and environmental gains associated with the removal of manganese from the process liquors, as well as the labour savings and improved oxidation reduction potential control possible in leaching using the Caro's acid system. Some changes in operating parameters were necessary with the introduction of Caro's acid to the treatment plant. Operating results have confirmed the relationship between oxidant demand and uranium content of ore established during the trials. Acid savings have been as predicted from the plant trials. The major saving has been of hydrated lime required for tailings neutralisation

  15. Solid acid catalysis from fundamentals to applications

    Hattori, Hideshi

    2014-01-01

    IntroductionTypes of solid acid catalystsAdvantages of solid acid catalysts Historical overviews of solid acid catalystsFuture outlookSolid Acids CatalysisDefinition of acid and base -Brnsted acid and Lewis acid-Acid sites on surfacesAcid strengthRole of acid sites in catalysisBifunctional catalysisPore size effect on catalysis -shape selectivity-Characterization of Solid Acid Catalysts Indicator methodTemperature programmed desorption (TPD) of ammoniaCalorimetry of adsorption of basic moleculesInfrare

  16. Amino Acid Decarboxylase Activity of Some Lactic Acid Bacteria

    Pelin ERTÜRKMEN; Turhan, İlkay; Öner, Zübeyde

    2015-01-01

    Microorganisms which have decarboxylase activity can form biogenic amine by enzymatic decarboxylation of amino acids in foods. Histamine poisoning results from consumption of foods typically certain types of fish and cheeses that contain unusually high levels of histamine. Therefore, decarboxylase activity is an important problem at the selection of lactic acid bacteria as a starter culture in fermented products. In this study, decarboxylase activities of 161 lactic acid bacteria (LAB) strain...

  17. Synthesis of stearic acid triethanolamine ester over solid acid catalysts

    Tao Geng; Qiu Xiao Li; Ya Jie Jiang; Wei Wang

    2010-01-01

    The synthesis of stearic acid triethanolamine ester over solid acid catalysts was investigated.The results showed that the catalytic activity and selectivity of zirconium sulfate supported on SBA-15(6)(pore diameter 6 nm)is better than that of commonly used hypophosphorous acid,zirconium sulfate supported on MCM-41 and zirconium sulfate supported on SBA-15(9)(pore diameter 9 nm).

  18. Bile acid interactions with cholangiocytes

    Xuefeng Xia; Heather Francis; Shannon Glaser; Gianfranco Alpini; Gene LeSage

    2006-01-01

    Cholangiocytes are exposed to high concentrations of bile acids at their apical membrane. A selective transporter for bile acids, the Apical Sodium Bile Acid Cotransporter (ASBT) (also referred to as Ibat; gene name Slc10a2)is localized on the cholangiocyte apical membrane. On the basolateral membrane, four transport systems have been identified (t-ASBT, multidrug resistance (MDR)3,an unidentified anion exchanger system and organic solute transporter (Ost) heteromeric transporter, OstαOstβ. Together, these transporters unidirectionally move bile acids from ductal bile to the circulation. Bile acids absorbed by cholangiocytes recycle via the peribiliaryplexus back to hepatocytes for re-secretion into bile.This recycling of bile acids between hepatocytes and cholangiocytes is referred to as the cholehepatic shunt pathway. Recent studies suggest that the cholehepatic shunt pathway may contribute in overall hepatobiliary transport of bile acids and to the adaptation to chronic cholestasis due to extrahepatic obstruction. ASBT is acutely regulated by an adenosine 3', 5'-monophosphate (cAMP)-dependent translocation to the apical membrane and by phosphorylation-dependent ubiquitination and proteasome degradation. ASBT is chronically regulated by changes in gene expression in response to biliary bile acid concentration and inflammatory cytokines.Another potential function of cholangiocyte ASBT is to allow cholangiocytes to sample biliary bile acids in order to activate intracellular signaling pathways. Bile acids trigger changes in intracellular calcium, protein kinase C (PKC), phosphoinositide 3-kinase (PI3K), mitogenactivated protein (MAP) kinase and extracellular signalregulated protein kinase (ERK) intracellular signals.Bile acids significantly alter cholangiocyte secretion,proliferation and survival. Different bile acids have differential effects on cholangiocyte intracellular signals,and in some instances trigger opposing effects on cholangiocyte secretion

  19. Molecular Simulation of Naphthenic Acid Removal on Acidic Catalyst Ⅱ. Experimental results of catalytic decarboxylation over acidic catalysts

    Fu Xiaoqin; Tian Songbai; Hou Shuandi; Longjun; Wang Xieqing

    2008-01-01

    The energy barriers of thermal decarboxylation reactions of petroleum acids and catalytic decarboxylation reactions of Br(o)nsted acid and Lewis acid were analyzed using molecular simulation technology.Compared with thermal decarboxylation reactions of petroleum acids, the decarboxylation reactions by acid catalysts were easier to occur. The decarboxylaton effect by Lewis acid was better than Br(o)nsted acid. The mechanisms of catalytic decarboxylation over acid catalyst were also verified by experiments on a fixed bed and a fluidized bed, the experimental results showed that the rate of acid removal could reach up to 97% over the acidic catalyst at a temperature above 400℃.

  20. Halogenated fatty acids

    Mu, Huiling; Sundin, Peter; Wesén, Clas

    1997-01-01

    bound in different lipids. For the detection and identification of individual, halogenated fatty acid methyl esters (FAMEs) liberated from the lipids, gas chromatography (GC) has been employed together with detection methods such as electron capture detection, electrolytic conductivity detection (ELCD......), atomic emission spectrometry, and mass spectrometry. For most environmental samples, chlorinated FAMEs must be enriched prior to GC. ELCD is a useful detection method for indicating halogenated FAMEs in the chromatograms, and tentative identification of the halogenated species can be obtained by...... calculation of retention indices. For closer identification of halogenated FAMEs, mass spectrometry (MS) is very useful, in particular when employing the chemical ionisation mode. MS identification, however, is highly facilitated if halogenated species are first indicated by element-selective methods....

  1. Polyunsaturated Fatty Acids in Children

    Lee, Ji-Hyuk

    2013-01-01

    Polyunsaturated fatty acids (PUFAs) are the major components of brain and retina, and are the essential fatty acids with important physiologically active functions. Thus, PUFAs should be provided to children, and are very important in the brain growth and development for fetuses, newborn infants, and children. Omega-3 fatty acids decrease coronary artery disease and improve blood flow. PUFAs have been known to have anti-inflammatory action and improved the chronic inflammation such as auto-im...

  2. Allelopathic Interactions Involving Phenolic Acids

    Blum, U.

    1996-01-01

    A major concern regarding allelopathic interactions involving phenolic acids in no-till systems pertains to the fact that concentrations of individual phenolic acids recoverable from field soils are well below levels required for inhibition of germination and seedling growth in laboratory bioassays. Field soils contain a variety of phenolic acids as well as other toxic and nontoxic organic compounds that are available to interact with seeds and roots; whereas in laboratory bioassays, with few...

  3. Fatty acid biosynthesis in actinomycetes

    Gago, Gabriela; Diacovich, Lautaro; Arabolaza, Ana; Tsai, Shiou-Chuan; Gramajo, Hugo

    2011-01-01

    All organisms that produce fatty acids do so via a repeated cycle of reactions. In mammals and other animals, these reactions are catalyzed by a type I fatty acid synthase (FAS), a large multifunctional protein to which the growing chain is covalently attached. In contrast, most bacteria (and plants) contain a type II system in which each reaction is catalyzed by a discrete protein. The pathway of fatty acid biosynthesis in Escherichia coli is well established and has provided a foundation fo...

  4. Kojic acid in organic synthesis

    ZIRAK, MARYAM; Eftekhari-Sis, Bagher

    2015-01-01

    The reactions of kojic acid in organic synthesis are reviewed. The aim of this review is to cover the literature up to the end of 2014, showing the distribution of publications involving kojic acid chemistry in the synthesis of various pyrone containing compounds, pyridine and pyridone heterocycles, and also other organic compounds. First, introductory text about the preparation, biological, and industrial applications, and the chemical properties of kojic acid is given. Then its uses in orga...

  5. [Total synthesis of nordihydroguaiaretic acid].

    Wu, A X; Zhao, Y R; Chen, N; Pan, X F

    1997-04-01

    beta-Keto ester(5) was obtained from vanilin through etherification, oxidation and condensation with acetoacetic ester, (5) on oxidative coupling reaction by NaOEt/I2 produced dimer (6) in high yield. Acid catalyzed cyclodehydration of (6) gave the furan derivative(7), and by a series of selective hydrogenation nordihydroguaiaretic acid, furoguaiacin dimethyl ether and dihydroguaiaretic acid dimethyl ether were synthesized. PMID:11499030

  6. Main: MPB3 [TP Atlas

    Full Text Available d its complexes with lysophosphatidic acids (LPAs) produced by NPP2 - We have identified compounds that inhibit the acti...ng - Our NPP2 inhibitors have exhibited striking therapeutic efficacy in lung and kidney fibrosis models NPP (Ectonucleotid... (LPA). Because of its ability to stimulate cell proliferation, aberrant LPA-signaling has been linked to can...cer. NPP6 produces choline that is an essential nutrient. Since choline and its metabolites ...ct. NPP1 regulates physiologic calcification. NPP2 (Autotaxin) generates the lipid signaling molecule lysophosphatidic acid

  7. ACETIC ACID AND A BUFFER

    2009-01-01

    The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

  8. Valproic Acid Induced Hyperammonaemic Encephalopathy

    Objective: To observe clinical and laboratory features of valproic acid-induced hyperammonaemic encephalopathy in patients taking valproic acid. Methods: Observational study was conducted at the Neurology Department, Dow University of Health Sciences, Civil Hospital, Karachi, from February 26, 2010 to March 20, 2011. Ten patients on valproic acid therapy of any age group with idiopathic or secondary epilepsy, who presented with encephalopathic symptoms, were registered and followed up during the study. Serum ammonia level, serum valproic acid level, liver function test, cerebrospinal fluid examination, electroencephalogram and brain imaging of all the patients were done. Other causes of encephalopathy were excluded after clinical and appropriate laboratory investigations. Microsoft Excel 2007 was used for statistical analysis. Results: Hyperammonaemia was found in all patients with encephalopathic symptoms. Rise in serum ammonia was independent of dose and serum level of valproic acid. Liver function was also found to be normal in 80% (n=8) of the patients. Valproic acid was withdrawn in all patients. Three (30%) patients improved only after the withdrawal of valproic acid. Six (60%) patients improved after L-Carnitine replacement, one (10%) after sodium benzoate. On followup, serum ammonia had reduced to normal in five (50%) patients and to more than half of the baseline level in two (20%) patients. Three (30%) patients were lost to followup after complete clinical improvement. Conclusion: Within therapeutic dose and serum levels, valproic acid can cause symptomatic hyperammonaemia resulting in encephalopathy. All patients taking valproic acid presenting with encephalopathic symptoms must be monitored for the condition. (author)

  9. Synthesis of Asymmetric Propanetriol Analogues

    2002-01-01

    From natural tartaric acid, (R)-2-benzyloxy-3-(2-tetrahydropyranyloxy) propanol 3 was designed and synthesized, and (R)-2-benzyloxy-3-(4-methoxybenzyloxy) propanol 7 was prepared in a new method. They can be used as chiral synthons of lysophosphatidic acid and other compounds with asymmetric propanetriol backbone.

  10. Peptide Nucleic Acids Having Amino Acid Side Chains

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than the corresponding DNA or RNA strands, and exhibit increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a group consisting of...

  11. Are Strong Bronsted Acids Necessarily Strong Lewis Acids?

    Sen-Gupta, K; Roy, D R; Subramanian, V

    2006-01-01

    The Broensted and Lowry acid base theory is based on the capacity of proton donation or acceptance (in the presence or absence of a solvent) whereas the Lewis acid base theory is based on the propensity of electron pair acceptance or donation. We explore through DFT calculation the obvious question whether these two theories are in conformity with each other. We use pKa as the descriptor for the Broensted and Lowry acidity. The DFT descriptors like ionization potential, electron affinity, electronegativity, hardness and global electrophilicity are computed for 58 organic and inorganic acids. The fractional electron transfer, del(N) and the associated energy change, del(E) for the reaction of these acids with trimethyl amine (a strong base) are used as the possible descriptors for the Lewis acidity. A near exponential decrease in del(N) and (-del(E)) values is observed in general with an increase in pKa values. The findings reveal that a stronger Broensted acid in most cases behaves as a stronger Lewis acid as...

  12. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances

    Je Min Lee

    2016-01-01

    Full Text Available Polyunsaturated fatty acids (PUFAs are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism.

  13. A comparison of chromic acid and sulfuric acid anodizing

    Danford, M. D.

    1992-01-01

    Because of federal and state mandates restricting the use of hexavalent chromium, it was deemed worthwhile to compare the corrosion protection afforded 2219-T87 aluminum alloy by both Type I chromic acid and Type II sulfuric acid anodizing per MIL-A-8625. Corrosion measurements were made on large, flat 2219-T87 aluminum alloy sheet material with an area of 1 cm(exp 2) exposed to a corrosive medium of 3.5-percent sodium chloride at pH 5.5. Both ac electrochemical impedance spectroscopy and the dc polarization resistance techniques were employed. The results clearly indicate that the corrosion protection obtained by Type II sulfuric acid anodizing is superior, and no problems should result by substituting Type II sulfuric acid anodizing for Type I chromic acid anodizing.

  14. Carbonic Acid Retreatment of Biomass

    Baylor university

    2003-06-01

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. (1) Solidify the theoretical understanding of the binary CO{sub 2}/H{sub 2}O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. (2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. (3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. (4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. (5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for

  15. Carbonic Acid Pretreatment of Biomass

    G. Peter van Walsum; Kemantha Jayawardhana; Damon Yourchisin; Robert McWilliams; Vanessa Castleberry

    2003-05-31

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. 1) Solidify the theoretical understanding of the binary CO2/H2O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. 2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. 3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. 4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. 5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic

  16. Ghrelin and gastric acid secretion

    Koji Yakabi; Junichi Kawashima; Shingo Kato

    2008-01-01

    Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in-vivo experiment. In the studies, the mechanism for the action of ghrelin was also investigated. It was shown that vagotomy completely inhibited the action of ghrelin on the secretion of gastric acid suggesting that vagal nerve is involved in the mechanism for the action of ghrelin on acid secretion. As famotidine did not inhibit ghrelin-in-duced acid secretion in the study by Masuda et al, they concluded that histamine was not involved in the action of ghrelin on acid secretion. However, we have shown that famotidine completely inhibited ghrelin-induced acid secretion and histidine decarboxylase (HDC) mRNA was increased in gastric mucosa by ghrelin injection which is inhibited by vagotomy Our results indicate that histamine is involved in the action of ghrelin on acid secretion. Furthermore synergistic action of gastrin and ghrelin on gastric add secretion was shown. Although gastrin has important roles in postprandial secretion of gastric acid, ghrelin may be related to acid secretion during fasting period or at night. However, further studies are needed to elucidate the physiological role of ghrelin in acid secretion.

  17. Origin of nucleic acids

    The appearance of nucleic acids is the first event after the birth of membranes which made it possible to assure the perenniality of information. The complexity of these molecules has led some scientists to propose that they were not prebiotic but rather derived a more simple and achiral primitive ancestor. This hypothesis suggests that ribose possesses properties that allowed the formation of certain polysaccharides which evolved to RNA. The first step of the hypothesis is the selection and concentration of ribofuranose. This sugar has chelating properties and its alpha-ribofuranose is favoured in the chelating position. The density of the sugar with a heavy cation is greater than water and thus the complex can escape the UV radiation at the surface of the ocean. The particularity of ribose is to be able to form a homochiral regular array of these basic chelating structures with pyrophosphite. These arrays evolve towards the formation of polysaccharides (poly ribose phosphate) which have a very organized structure. These polysaccharides in turn evolve to RNA by binding of adenine and deoxyguanine which are HCN derivatives that can react with the polysaccharides. The primitive RNA is methylated and oxidized to form prebiotic RNA with adenosine, cytidine, 7methyl-guanosine and ribothymidine as nucleic bases. The pathway of biosynthesis of DNA form RNA will be studied. I suggest that the appearance of DNA results form the interaction between prebiotic double stranded RNA and proteins. DNA could be a product of RNA degradation by proteins. The catabolism of RNA to DNA requires a source of free radicals, protons and hydrides. RNA cannot produce free radicals, which are provided by the phenol group of the amino acid tyrosien. Protons are provided by the medium and hydrides are provided by 7-methyl-guanosine which can fix hydrides coming from hydrogen gas and donate them for the transformation of a riboside to a deoxyriboside. This pathway suggests that DNA appeared at

  18. Cocrystals of fenamic acids with nicotinamide

    Fábián, László; Hamill, Noel; Eccles, Kevin S; Moynihan, Humphrey A; Maguire, Anita R.; McCausland, Linda; Lawrence, Simon E.

    2011-01-01

    Cocrystal formation between nicotinamide and five fenamic acid derivative drugs (flufenamic acid, niflumic tolfenamic acid, mefenamic acid and meclofenamic acid) was investigated using solution-based and solid-state preparation methods. It was anticipated that the well-known acid-aromatic nitrogen heterosynthon would provide a sufficient driving force for cocrystallization. The experiments yielded cocrystals with four of the five acids. Although the structures of these molecules are similar, ...

  19. Caffeic acid derivatives from Bupleurum chinense

    Haghi, G.; Hatami, A.; Mehran, M.; Hosseini, H

    2014-01-01

    In this study, caffeic acid (CA) and its three derivatives including 3-caffeoylquinic acid (3-CQA, neochlorogenic acid), 4-caffeoylquinic acid (4-CQA, cryptochlorogenic acid), and 5-caffeoylquinic acid (5-CQA, chlorogenic acid) were identified in Bupleurum chinense aerial parts using reverse-phase high-performance liquid chromatography (RP-HPLC) with photodiode array (PDA) detector, reference compounds and chemical reactions. Separation was performed on a C18 column using gradient elution wit...

  20. Acid Tests and Basic Fun.

    McBride, John W.

    1995-01-01

    Explores acids and bases using different indicators, such as turmeric, purple grape juice, and lichens. Because some of these indicators are not as sensitive as cabbage juice or litmus paper, determining to which acids and bases each indicator is sensitive presents an enjoyable, problem-solving challenge for students. Presents directions for…

  1. Acid Rain: The Scientific Challenge.

    Godfrey, Paul J.

    1991-01-01

    Documents the workings and findings of the Massachusetts Acid Rain Monitoring Project, which has pooled the volunteer efforts of more than 1,000 amateur and professional scientists since 1983. Reports on the origins of air pollution, the prediction of acid rain, and its effects on both water life and land resources. (JJK)

  2. Acid Rain: An Educational Opportunity?

    Marion, James I.

    1984-01-01

    Deals with how educators can handle the subject of acid rain; illustrates suggestions with experiences of grade nine students visiting Frost Valley Environmental Education Center (Oliverea, New York) to learn scientific concepts through observation of outdoor phenomena, including a stream; and discusses acid rain, pH levels, and pollution control…

  3. Acid Rain: What's the Forecast?

    Bybee, Rodger

    1984-01-01

    Discusses various types of acid rain, considered to be a century-old problem. Topics include: wet and dry deposition, effects on a variety of environments, ecosystems subject to detrimental effects, and possible solutions to the problem. A list of recommended resources on acid rain is provided. (BC)

  4. Pantothenic acid (Vitamin B5)

    ... suggests that taking pantothenic acid in combination with pantethine and thiamine does not improve muscular strength or ... Pantothenic Acid, D-Pantothenyl Alcohol, Dexpanthenol, Dexpanthénol, Dexpanthenolum, ... Pantothenate, Pantothénate, Pantothénate de Calcium, Pantothenol, ...

  5. Bile acids for viral hepatitis

    Chen, Weikeng; Liu, J; Gluud, C

    2003-01-01

    The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness.......The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness....

  6. Folic Acid: Data and Statistics

    ... acid fortification in the United States Recently, the American Journal of Preventive Medicine published a new study looking at the costs ... acid fortification and spina bifida in the U.S. American Journal of Preventive Medicine. January 2016 [epub ahead of print]. Related Links ...

  7. Kinetics and Mechanism of Oxidation of Phenyl Acetic Acid and Dl-Mandelic Acid by Permanganate in Acid Medium

    B.Syama Sundar

    2014-06-01

    Full Text Available Kinetics of oxidation of phenyl acetic acid and DL- Mandelic acid by potassium permanganate in aqueous acetic acid and perchloric acid mixture reveals that the kinetic orders are first order in oxidant, first order in H+ and zero order in substrate for phenyl acetic acid. DL-Mandelic acid exhibits first order in oxidant and zero order in substrate. The results are rationalised by a mechanism involving intermediate formation of mandelic acid in case of Phenyl acetic acid and ester formation with Mn (VII in case of DL-Mandelic acid. The following order of reactivity is observed: DL-Mandelic acid > Phenyl acetic acid. The high reactivity of DL-Mandelic acid over phenyl acetic acid may be due to different mechanisms operating with the two substrates and benzaldehyde is the final product in both the cases.

  8. N-(3-Nitrophenylmaleamic acid

    B. Thimme Gowda

    2010-07-01

    Full Text Available In the title compound, C10H8N2O5, the molecule is slightly distorted from planarity. The molecular structure is stabilized by two intramolecular hydrogen bonds. The first is a short O—H...O hydrogen bond (H...O distance = 1.57 Å within the maleamic acid unit and the second is a C—H...O hydrogen bond (H...O distance = 2.24 Å which connects the amide group with the benzene ring. The nitro group is twisted by 6.2 (2° out of the plane of the benzene ring. The crystal structure manifests a variety of hydrogen bonding. The packing is dominated by a strong intermolecular N—H...O interaction which links the molecules into chains running along the b axis. The chains within a plane are further assembled by three additional types of intermolecular C—H...O hydrogen bonds to form a sheet parallel to the (overline{1}01 plane.

  9. Lactic Acid Bacteria

    ToddKlaenhammer

    2013-04-01

    Full Text Available Lactic acid bacteria (LAB are a diverse group of Gram-positive bacteria found in a vast array of environments including dairy products and the human gastrointestinal tract. In both niches, surface proteins play a crucial role in mediating interactions with the surrounding environment. The sortase enzyme is responsible for covalently coupling a subset of surface dependent proteins (SDPs to the cell wall of Gram-positive organisms through recognition of a conserved C-terminal LPXTG motif. Genomic sequencing of LAB and annotation has allowed for the identification of sortase and SDPs. Historically, sortase and SDPs were predominately investigated for their role in mediating pathogenesis. Identification of these proteins in LAB has shed light on their important roles in mediating nutrient acquisition through proteinase P as well as positive probiotic attributes including adhesion, mucus barrier function, and immune signaling. Furthermore, sortase expression signals in LAB have been exploited as a means to develop oral vaccines targeted to the gastrointestinal tract. In this review, we examine the collection of studies which evaluate sortase and SDPs in select species of dairy associated and health promoting LAB.

  10. Microfluidics in amino acid analysis.

    Pumera, Martin

    2007-07-01

    Microfluidic devices have been widely used to derivatize, separate, and detect amino acids employing many different strategies. Virtually zero-dead volume interconnections and fast mass transfer in small volume microchannels enable dramatic increases in on-chip derivatization reaction speed, while only minute amounts of sample and reagent are needed. Due to short channel path, fast subsecond separations can be carried out. With sophisticated miniaturized detectors, the whole analytical process can be integrated on one platform. This article reviews developments of lab-on-chip technology in amino acid analysis, it shows important design features such as sample preconcentration, precolumn and postcolumn amino acid derivatization, and unlabeled and labeled amino acid detection with focus on advanced designs. The review also describes important biomedical and space exploration applications of amino acid analysis on microfluidic devices. PMID:17542043

  11. Molten fatty acid based microemulsions.

    Noirjean, Cecile; Testard, Fabienne; Dejugnat, Christophe; Jestin, Jacques; Carriere, David

    2016-06-21

    We show that ternary mixtures of water (polar phase), myristic acid (MA, apolar phase) and cetyltrimethylammonium bromide (CTAB, cationic surfactant) studied above the melting point of myristic acid allow the preparation of microemulsions without adding a salt or a co-surfactant. The combination of SANS, SAXS/WAXS, DSC, and phase diagram determination allows a complete characterization of the structures and interactions between components in the molten fatty acid based microemulsions. For the different structures characterized (microemulsion, lamellar or hexagonal phases), a similar thermal behaviour is observed for all ternary MA/CTAB/water monophasic samples and for binary MA/CTAB mixtures without water: crystalline myristic acid melts at 52 °C, and a thermal transition at 70 °C is assigned to the breaking of hydrogen bounds inside the mixed myristic acid/CTAB complex (being the surfactant film in the ternary system). Water determines the film curvature, hence the structures observed at high temperature, but does not influence the thermal behaviour of the ternary system. Myristic acid is partitioned in two "species" that behave independently: pure myristic acid and myristic acid associated with CTAB to form an equimolar complex that plays the role of the surfactant film. We therefore show that myristic acid plays the role of a solvent (oil) and a co-surfactant allowing the fine tuning of the structure of oil and water mixtures. This solvosurfactant behaviour of long chain fatty acid opens the way for new formulations with a complex structure without the addition of any extra compound. PMID:27241163

  12. Hypocholesterolemic Effects of Eicosapentaenoic Acid and Docosahexaenoic Acid in Rats

    KANAZAWA, Akio; TESHIMA, Shin-ichi; TOKIWA, Shigeru; IMATANAKA, Nobuya; カナザワ, アキオ; テシマ, シンイチ; トキワ, シゲル; イマタナカ, ノブヤ; 金沢, 昭夫; 手島, 新一; 常盤, 繁; 今田中, 伸哉

    1984-01-01

    Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) methylesters (ME) were preparedfrom a squid-liver oil and their hypocholesterolemic activities examined with rats. The supplementof 0.3% EPA-ME to the diet containing 1.0% cholesterol and 4.0% butter as lipids reduced a serum-cholesterollevel markedly, whereas DHA-ME gave almost no effect on the serum-cholesterol level.Both EPA-ME and DHA-ME reduced the liver-cholesterol level as effectively as linoleic acid did.The supplement of smal...

  13. Analytical application of aminohydroxamic acids

    Anthranilic hydroxamic acid was prepared by coupling of methylanthranilate (prepared by esterification of anthranilic acid with methyl alcohol using the fisher-speir method) with freshly prepared hydroxylamine. The lignad was characterized by the usual reaction of hydroxamic acid with acidic V(V) and Fe(III) solutions that gives blood-red colour in amyl alcohol and deep-violet colour in aqueous solution, respectively. The absorbance of Fe(III)-hydroxamic acids complexes increases with increase of pH. In this study, the effect of pH on the absorbance of Fe(III)-anthranilic hydroxamic acid was in accordance with this trend. The maximum absorbance was obtained at pH 5.0 at maximum wavelength of 482 nm. For Cu(II)-anthranilic hydroxamic acid complex, the use of acidic basic pH lead to precipitation of Cu(II)-ligand complex. But when using buffer pH (acetic acid/sodium acetate) a clear green colour of Cu(II)-ligand complex was obtained. The maximum wavelength of 390 nm. V(V)-anthranilic hydroxamic acid complex was extracted in acidic medium in amyl alcohol at pH 2.0 because in aqueous solution V(V)-anthranilic hydroxamic acid complex has not clear colour. It was observed the the maximum extraction in acidic medium decrease sharply with the increasing of pH value. The maximum wavelength for maximum absorbance was recorded at 472 nm. V(V) interfered with determination of Fe(III)) above concentration of 2 ppm, whereas Cu(II) interferes slightly with the determination of Fe(III) ions even at a high concentration of the Cu(II) ions. Both Cu(II) and Ni(II) do not interfere with the determination of V(V) ions even at high concentrations, Fe(III) ion produced slight interference, while Mo(VI) ions have a pronounced interference. Both V(V) and Fe(III) ions interfered markedly with the determination of Cu(II) ions, and made impractical under conditions. However, the calibration curves for the three metal ions produced a practical linear dynamic range.(Author)

  14. The Property and Application of Arachidonic Acid

    王相勤; 姚建铭; 袁成凌; 王纪; 余增亮

    2002-01-01

    Arachidonic acid (AA) is one of the most important PUFAs (polyunsaturated fatty acids) in human body. A high-yield arachidonic acid-producing strain (mortierella alpina) was selected by ion implantation (the relative content of arachidonic acid is 70.2% among all fatty acids). This paper mainly introduced the structure, distribution, source, physiologic healthcare function and application of AA.

  15. The property and application of arachidonic acid

    Arachidonic acid (AA) is one of the most important PUFAs (polyunsaturated fatty acids) in human body. A high-yield arachidonic acid-producing strain (mortierella alpina) was selected by ion implantation (the relative content of arachidonic acid is 70.2% among all fatty acids). The author mainly introduced the structure, distribution, source, physiologic health care function and application of AA

  16. Diabetes and alpha lipoic acid

    IssyLaher

    2011-11-01

    Full Text Available Diabetes mellitus is a multi-faceted metabolic disorder where there is increased oxidative stress that contributes to the pathogenesis of this debilitating disease. This has prompted several investigations into the use of antioxidants as a complementary therapeutic approach. Alpha lipoic acid, a naturally occurring dithiol compound which plays an essential role in mitochondrial bioenergetic reactions, has gained considerable attention as an antioxidant for use in managing diabetic complications. Lipoic acid quenches reactive oxygen species, chelates metal ions, and reduces the oxidized forms of other antioxidants such as vitamin C, vitamin E and glutathione. It also boosts antioxidant defense system through Nrf2-mediated antioxidant gene expression and by modulation of peroxisome proliferator activated receptors-regulated genes. ALA inhibits nuclear factor kappa B and activates AMPK in skeletal muscles, which in turn have a plethora of metabolic consequences. These diverse actions suggest that a lipoic acid acts by multiple mechanisms, many of which have only been uncovered recently. In this review we briefly summarize the known biochemical properties of lipoic acid and then discussed the oxidative mechanisms implicated in diabetic complications and the mechanisms by which lipoic acid may ameliorate these reactions. The findings of some of the clinical trials in which lipoic acid administration has been tested in diabetic patients during the last 10 years are summarized. It appears that the clearest benefit of lipoic acid supplementation is in patients with diabetic neuropathy.

  17. Boronic acid-based autoligation of nucleic acids

    Barbeyron, R.; Vasseur, J.-J.; Smietana, M.;

    2013-01-01

    Abstract: The development of synthetic systems displaying dynamic and adaptive characteristics is a formidable challenge with wide applications from biotechnology to therapeutics. Recently, we described a dynamic and programmable nucleic acid-based system relying on the formation of reversible...

  18. Docosahexaenoic acid affects arachidonic acid uptake in megakaryocytes

    Schick, P.K.; Webster, P.

    1987-05-01

    Dietary omega 3 fatty acids are thought to prevent atherosclerosis, possibly by modifying platelet (PT) function and arachidonic acid (20:4) metabolism. The study was designed to determine whether omega 3 fatty acids primarily affect 20:4 metabolism in megakaryocytes (MK), bone marrow precursors of PT, rather than in circulating PT. MK and PT were isolated from guinea pigs and incubated with (/sup 14/C)-20:4 (0.13uM). Docosahexaenoic acid (22:6) is a major omega 3 fatty acid in marine oils. The incubation of MK with 22:6 (0.1, 1.0 uM) resulted in the decrease of incorporation of (/sup 14/C)-20:4 into total MK phospholipids, 16% and 41% respectively. Alpha-linolenic acid (18:3), a major omega 3 fatty acid present in American diets, had no effect on 20:4 uptake in MK. 22:6 primarily affected the uptake of (/sup 14/C)-20:4 into phosphatidylethanolamine (PE) and phosphatidylserine (PS) in MK. In MK, 22:6 (0.1, 1.0 uM) caused a decrease of incorporation of (/sup 14/C)-20:4 into PE, 21% and 55% respectively; a decrease into PS, 16% and 48% respectively; but only a decrease of 4% and 18%, respectively, into phosphatidylcholine; and a decrease of 3% and 21% into phosphatidylinositol 22:6 (3.0 uM) had no effect on the uptake of AA into PT phospholipids. The study shows that 22:6 has a selective effect on AA uptake in MK and that the acylation or transacylation of PE and PS are primarily affected. 22:6 and other marine omega 3 fatty acids appear to primarily affect megakaryocytes which may result in the production of platelets with abnormal content and compartmentalization of AA.

  19. Amino Acids from a Comet

    Cook, Jamie Elisla

    2009-01-01

    NASA's Stardust spacecraft returned samples from comet 81P/Wild 2 to Earth in January 2006. Examinations of the organic compounds in cometary samples can reveal information about the prebiotic organic inventory present on the early Earth and within the early Solar System, which may have contributed to the origin of life. Preliminary studies of Stardust material revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds (cometary- vs. terrestrial contamination) could not be identified. We have recently measured the carbon isotopic ratios of these amino acids to determine their origin, leading to the first detection of a coetary amino acid.

  20. PHARMACOLOGICAL ACTIVITIES OF PROTOCATECHUIC ACID.

    Khan, Abida Kalsoom; Rashid, Rehana; Fatima, Nighat; Mahmood, Sadaf; Mir, Sadullah; Khan, Sara; Jabeen, Nyla; Murtaza, Ghulam

    2015-01-01

    Protocatechuic acid (3,4-dihydroxybenzoic acid, PCA) is a simple phenolic acid. It is found in a large variety of edible plants and possesses various pharmacological activities. This article aims to review the modern trends in phytochemical isolation and extraction of PCA from plants and other natural resources. Moreover, this article also encompasses pharmacological and biological activities of PCA. It is well known to have anti-inflammatory, antioxidant, anti-hyperglycemia, antibacterial, anticancer, anti-ageing, anti-athro- genic, anti-tumoral, anti-asthma, antiulcer, antispasmodic and neurological properties. PMID:26647619

  1. Treatment of acid mine wastewaters

    Acid mine drainage often results from the oxidation sulfide minerals to form sulfuric acid. As a consequence, high concentrations of metals in the both the suspended and dissolved state result from the low pH water. This paper discusses several of the more common treatment methods for acid mine drainage including the use of chemical precipitation agents, pH correction agents, filtration methods, and biodegradation methods. Advanced treatment technologies are also briefly described and include microfiltration, reverse osmosis, ion exchange, and electrodialysis

  2. Macromolecular organic acids in the Murchison meteorite

    Watson, J.S.; Sephton, M.A.; Gilmour, I.

    2005-01-01

    This study has detected bound organic acids within the Murchison meteorite organic macromolecule. Benzoic acid was the most abundant compound; other abundant compounds include C1 and C2 benzoic acids. Their origin and significance will be discussed.

  3. Molar extinction coefficients of some fatty acids

    Sandhu, G.K.; Singh, K.; Lark, B.S.;

    2002-01-01

    ) and stearic acid (C18H36O2), has been measured at the photon energies 81, 356, 511, 662, 1173 and 1332 keV. Experimental values for the molar extinction coefficient, the effective atomic number and the electron density have been derived and compared with theoretical calculations. There is good......The attenuation of gamma rays in some fatty acids, viz. formic acid (CH2O2), acetic acid (C2H4O2), propionic acid (C3H6O2), butyric acid (C4H8O2), n-hexanoic acid (C6H12O2), n-caprylic acid (C8H16O2), lauric acid (C12H24O2), myristic acid (C14H28O2), palmitic acid (C16H32O2), oleic acid (C18H34O2...

  4. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    NEENA GARG

    2015-10-01

    Full Text Available Lactic acid bacteria (LAB is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LAB are used as starter culture, consortium members and bioprotective agents in food industry that improve food quality, safety and shelf life. A variety of probiotic LAB species are available including Lactobacillus acidophilus, L. bulgaricus, L. lactis, L. plantarum, L. rhamnosus, L. reuteri, L. fermentum, Bifidobacterium longum, B. breve, B. bifidum, B. esselnsis, B. lactis, B. infantis that are currently recommended for development of functional food products with health-promoting capacities.

  5. Treatment of hydrofluoric acid burns

    Thiele, B.; Winter, U.J.; Mahrle, G.; Steigleder, G.K.

    1986-01-31

    A chemical-plant worker sustained hydrofluoric acid burns during cleaning procedures. Intra-arterial perfusion and intralesional injections of calcium gluconate solution prevented progression of the burns into deeper tissue layers.

  6. [Treatment of hydrofluoric acid burns].

    Thiele, B; Winter, U J; Mahrle, G; Steigleder, G K

    1986-01-31

    A chemical-plant worker sustained hydrofluoric acid burns during cleaning procedures. Intra-arterial perfusion and intralesional injections of calcium gluconate solution prevented progression of the burns into deeper tissue layers. PMID:3943470

  7. Main: Amino acid Analysis [KOME

    Full Text Available Amino acid Analysis UniProt search ... blastx result Result of blastx search ... against UniProt protein ... database kome_uniprot_search _blastx_result.zip kome_uniprot_search _blastx_resul ...

  8. Main: Amino acid Analysis [KOME

    Full Text Available Amino acid Analysis SwissProt search ... result Result of blastx search ... against SwissProt protein da ... tabase kome_swissprot_search _result.zip kome_swissprot_search _result ...

  9. Biotechnological production of citric acid

    Belén Max

    2010-12-01

    Full Text Available This work provides a review about the biotechnological production of citric acid starting from the physicochemical properties and industrial applications, mainly in the food and pharmaceutical sectors. Several factors affecting citric acid fermentation are discussed, including carbon source, nitrogen and phosphate limitations, pH of culture medium, aeration, trace elements and morphology of the fungus. Special attention is paid to the fundamentals of biochemistry and accumulation of citric acid. Technologies employed at industrial scale such as surface or submerged cultures, mainly employing Aspergillus niger, and processes carried out with Yarrowia lipolytica, as well as the technology for recovering the product are also described. Finally, this review summarizes the use of orange peels and other by-products as feedstocks for the bioproduction of citric acid.

  10. The Nucleic Acid Database (NDB)

    Berman, H. M.; Feng, Z.; Schneider, Bohdan; Westbrook, J.; Zardecki, C.

    Vol. F. Dordrecht : Kluwer Academic, 2001 - (Rossmann, M.; Arnold, E.), s. 657-682 Institutional research plan: CEZ:AV0Z4040901 Keywords : database * nucleic acid Subject RIV: CF - Physical ; Theoretical Chemistry

  11. Structural features of lignohumic acids

    Novák, František; Šestauberová, Martina; Hrabal, R.

    2015-01-01

    Roč. 1093, August (2015), s. 179-185. ISSN 0022-2860 Institutional support: RVO:60077344 Keywords : C-13 NMR * FTIR * humic acids * lignohumate * lignosulfonate * structure Subject RIV: DF - Soil Science Impact factor: 1.602, year: 2014

  12. Acid Rain - Acidification and Recovery

    Norton, S. A.; Kopáček, Jiří; Fernandez, I. J.

    2. Elsevier, 2014 - (Holland., H.; Turekian, K.), s. 379-414 Institutional support: RVO:60077344 Keywords : acid ification * nitrogen * nutrients * sulfur * trace metals Subject RIV: DJ - Water Pollution ; Quality

  13. Uranium extraction from phosphoric acid

    A study has been carried out for the extraction of uranium from phosphoric acid produced in Algeria. First of all, the Algerian phosphoric acid produced in Algeria by SONATRACH has been characterised. This study helped us to synthesize a phosphoric acid that enabled us to pass from laboratory tests to pilot scale tests. We have then examined extraction and stripping parameters: diluent, DZEPHA/TOPO ratio and oxidising agent. The laboratory experiments enabled us to set the optimum condition for the choice of diluent, extractant concentration, ratio of the synergic mixture, oxidant concentration, redox potential. The equilibrium isotherms lead to the determination of the number of theoretical stages for the uranium extraction and stripping of uranium, then the extraction from phosphoric acid has been verified on a pilot scale (using a mixer-settler)

  14. Bile acid sequestrants for cholesterol

    ... 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 ...

  15. MedlinePlus: Folic Acid

    ... Tests Homocysteine Test (American Association for Clinical Chemistry) Vitamin B12 and Folate Test (American Association for Clinical Chemistry) Related Issues Folic Acid Supplements: Can They Slow Cognitive Decline? (Mayo Foundation for Medical Education and Research) Genetics ...

  16. Branched-Chain Amino Acids

    Pátek, Miroslav

    Berlin : Springer-Verlag Berlin Heidelberg, 2007, s. 129-162. ISBN 978-3-540-48595-7 Institutional research plan: CEZ:AV0Z50200510 Keywords : amino acids * homologous reactions Subject RIV: EE - Microbiology, Virology

  17. Gene Expression Analysis of a Panel of Cell Lines That Differentially Restrict HIV-1 CA Mutants Infection in a Cyclophilin A-Dependent Manner

    Shah, Vaibhav B.; Aiken, Christopher

    2014-01-01

    HIV-1 replication is dependent on binding of the viral capsid to the host protein cyclophilin A (CypA). Interference with cyclophilin A binding, either by mutations in the HIV-1 capsid protein (CA) or by the drug cyclosporine A (CsA), inhibits HIV-1 replication in cell culture. Resistance to CsA is conferred by A92E or G94D substitutions in CA. The mutant viruses are also dependent on CsA for their replication. Interestingly, infection of some cell lines by these mutants is enhanced by CsA, while infection of others is not affected by the drug. The cells are thus termed nonpermissive and permissive, respectively, for infection by CsA-dependent mutants. The mechanistic basis for the cell type dependence is not well understood, but has been hypothesized to result from a dominant-acting host factor that blocks HIV-1 infection by a mechanism that requires CypA binding to the viral capsid. In an effort to identify a CypA-dependent host restriction factor, we adopted a strategy involving comparative gene expression analysis in three permissive and three non-permissive cell types. We ranked the genes based on their relative overexpression in non-permissive cell types compared to the permissive cell types. Based on specific selection criteria, 26 candidate genes were selected and targeted using siRNA in nonpermissive (HeLa) cells. Depletion of none of the selected candidate genes led to the reversal of CsA-dependent phenotype of the A92E mutant. Our data suggest that none of the 26 genes tested is responsible for the dependence of the A92E mutant on CsA. Our study provides gene expression data that may be useful for future efforts to identify the putative CypA-dependent HIV-1 restriction factor and in studies of other cell-specific phenotypes. PMID:24663101

  18. Acid diffusion through polymer films

    Zhang, P. Linda; Eckert, Andrew R.; Willson, C. Grant; Webber, Stephen E.; Byers, Jeffrey D.

    1997-07-01

    In order to perform 0.2 micrometer processes, one needs to study the diffusion of photoacid generators within the photoresist system, since diffusion during post exposure bake time has an influence on the critical dimension (CD). We have developed a new method to study the diffusion of photoacid generators within a polymer film. This new method is based on monitoring the change of the fluorescence intensity of a pH- sensitive fluorescent dye caused by the reaction with photoacid. A simplified version of this experiment has been conducted by introducing acid vapor to quench the fluorescence intensity of this pH sensor. A thin polymer film is spin cast onto the sensor to create a barrier to the acid diffusion process. During the acid diffusion process, the fluorescence intensity of this pH sensor is measured in situ, using excitation and emission wavelengths at 466 nm and 516 nm, respectively. Fluoresceinamine, the pH sensitive fluorescent dye, is covalently bonded onto the treated quartz substrate to form a single dye layer. Poly(hydroxystyrene) (Mn equals 13k, Tg equals 180 degrees Celsius) in PGMEA (5% - 18% by weight) is spin cast onto this quartz substrate to form films with varying thickness. The soft bake time is 60 seconds at 90 degrees Celsius and a typical film has a thickness of 1.4 micrometers. Trifluoroacetic acid is introduced into a small chamber while the fluorescence from this quartz window is observed. Our study focuses on finding the diffusion constant of the vaporized acid (trifluoroacetic acid) in the poly(hydroxystyrene) polymer film. By applying the Fick's second law, (It - Io)/(I(infinity ) - Io) equals erfc [L/(Dt)1/2] is obtained. The change of fluorescence intensity with respect to the diffusion time is monitored. The above equation is used for the data analysis, where L represents the film thickness and t represents the average time for the acid to diffuse through the film. The diffusion constant is calculated to be at the order of 10

  19. Simultaneous analysis of small organic acids and humic acids using high performance size exclusion chromatography

    Qin, X.P.; Liu, F.; Wang, G.C.; Weng, L.P.

    2012-01-01

    An accurate and fast method for simultaneous determination of small organic acids and much larger humic acids was developed using high performance size exclusion chromatography. Two small organic acids, i.e. salicylic acid and 2,3-dihydroxybenzoic acid, and one purified humic acid material were used

  20. Nucleic Acid Aptamers Against Proteases

    Dupont, D M; Andersen, L M; Bøtkjær, Kenneth Alrø;

    2011-01-01

    Proteases are potential or realized therapeutic targets in a wide variety of pathological conditions. Moreover, proteases are classical subjects for studies of enzymatic and regulatory mechanisms. We here review the literature on nucleic acid aptamers selected with proteases as targets. Designing...... strategies and of new principles for regulating the activity of the inhibitory action of aptamers of general interest to researchers working with nucleic acid aptamers...

  1. Piperidine nucleoside phosphonic acid derivatives

    Kovačková, Soňa; Dračínský, Martin; Rejman, Dominik

    Praha : Institute of Organic Chemistry and Biochemistry AS CR, v. v. i., 2011 - (Hocek, M.), s. 372-374 ISBN 978-80-86241-37-1. - (Collection Symposium Series. 12). [Chemistry of Nucleic Acid Components /15./. Český Krumlov (CZ), 05.06.2011-10.06.2011] Institutional research plan: CEZ:AV0Z40550506 Keywords : piperidine nucleoside * nucleoside phosphonic acids * nucleoside diphosphate analogs * nucleotide analogs Subject RIV: CC - Organic Chemistry

  2. Aqueous Photochemistry of Glyoxylic Acid.

    Eugene, Alexis J; Xia, Sha-Sha; Guzman, Marcelo I

    2016-06-01

    Aerosols affect climate change, the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. While the formation of secondary organic aerosols (SOA) from gas phase precursors is relatively well understood, studying aqueous chemical reactions contributing to the total SOA budget is the current focus of major attention. Field measurements have revealed that mono-, di-, and oxo-carboxylic acids are abundant species present in SOA and atmospheric waters. This work explores the fate of one of these 2-oxocarboxylic acids, glyoxylic acid, which can photogenerate reactive species under solar irradiation. Additionally, the dark thermal aging of photoproducts is studied by UV-visible and fluorescence spectroscopies to reveal that the optical properties are altered by the glyoxal produced. The optical properties display periodicity in the time domain of the UV-visible spectrum of chromophores with absorption enhancement (thermochromism) or loss (photobleaching) during nighttime and daytime cycles, respectively. During irradiation, excited state glyoxylic acid can undergo α-cleavage or participate in hydrogen abstractions. The use of (13)C nuclear magnetic resonance spectroscopy (NMR) analysis shows that glyoxal is an important intermediate produced during direct photolysis. Glyoxal quickly reaches a quasi-steady state as confirmed by UHPLC-MS analysis of its corresponding (E) and (Z) 2,4-dinitrophenylhydrazones. The homolytic cleavage of glyoxylic acid is proposed as a fundamental step for the production of glyoxal. Both carbon oxides, CO2(g) and CO(g) evolving to the gas-phase, are quantified by FTIR spectroscopy. Finally, formic acid, oxalic acid, and tartaric acid photoproducts are identified by ion chromatography (IC) with conductivity and electrospray (ESI) mass spectrometry (MS) detection and (1)H NMR spectroscopy. A reaction mechanism is proposed based on all experimental observations. PMID:27192089

  3. Deoxyribonucleic acid methylation in mycobacteria.

    R. Srivastava; Gopinathan, K P; Ramakrishnan, T.

    1981-01-01

    Deoxyribonucleic acid modification in six strains of mycobacteria was investigated. The presence of 5-methylcytosine in the virulent strain Mycobacterium tuberculosis H37Rv and its absence in the avirulent strain M. tuberculosis H37Ra and other saprophytic, fast-growing mycobacteria appear to be the salient features. However, deoxyribonucleic acid from M. smegmatis SN2 lysogenized with the temperature phage I3 showed the presence of 5-methylcytosine. All of the strains had N6-methyladenine.

  4. Bacillus subtilis Deoxyribonucleic Acid Gyrase

    Sugino, A; Bott, K F

    1980-01-01

    Bacillus subtilis 168 was shown to contain a deoxyribonucleic acid (DNA) gyrase activity which closely resembled those of the enzymes isolated from Escherichia coli and Micrococcus luteus in its enzymatic requirements, substrate specificity, and sensitivity to several antibiotics. The enzyme was purified from the wild type and nalidixic acid-resistant and novobiocin-resistant mutants of B. subtilis and was functionally characterized in vitro. The genetic loci nalA and novA but not novB were s...

  5. Regulatory aspects of acid rain

    On November 15, 1990, President Bush signed the 1990 Clean Air Act (CAA) amendments into law. This was a historical document which marked the beginning of a concerted effort to address a most pressing environmental problem of this century, namely acid rain. Acid rain is the generic term used to describe the phenomenon by which sulfur dioxides (SO2) and nitrogen oxides (NOx) react in the atmosphere in the presence of sunlight to form acids which are scrubbed out of the atmosphere during a precipitation event. When this happens the pH of the precipitation falls considerably below 7.0. Years of research have shown that acid rain has a very detrimental effect on soils, vegetation, and marine life. The large amounts of SO2 and NOx being released by coal-fired utility boilers have largely incriminated utility companies as being the culprits. Most of the research work has been in Canada because the direction of the jet stream across the US is such that the emissions from the midwestern and northeastern US are carried into southeastern Canada. An interim report from the National Acid Precipitation Assessment Program (NAPAP) has assessed that power plants contribute up to 65% of the national annual emissions of SO2, and up to 29% of the NOx emissions. It is for these reasons that acid rain control has been given such a priority by legislators

  6. Specific bile acid radioimmunoassays for separate determinations of unconjugated cholic acid, conjugated cholic acid and conjugated deoxycholic acid in serum and their clinical application

    Specific radioimmunoassays have been developed for separate determinations of unconjugated cholic acid, conjugated cholic acid and conjugated deoxycholic acid in serum. Before carrying out the radioimmunoassay, the serum bile acids were extracted with Amberlite XAD-2. Unconjugated cholic acid was separated from glyco- and taurocholic acids by thin-layer chromatography. At 50% displacement of bound labelled glyco-[3H]-cholic acid, using antiserum obtained after immunization with cholic acid-bovine serum albumin-conjugate, the cross-reactivity of taurocholic acid was 100%, cholic acid 80%, glycochenodeoxycholic acid 10%, chenodeoxycholic acid 7%, conjugated deoxycholic acid 3% and conjugated lithocholic acid 3H]-cholic acid in the solid-phase radioimmunoassay was linear on a logit-log plot from 5 to 200 pmol of unlabelled cholic acid. The coefficient of variation between samples was 5%. The clinical application of these bile acid radioimmunoassays is shown by an ''oral cholate tolerance test'', which is a sensitive indicator of liver function, and by an ''oral cholylglycine tolerance test'' which is a useful test for bile acid absorption. (author)

  7. Performance of Different Acids on Sandstone Formations

    M. A. Zaman

    2013-12-01

    Full Text Available Stimulation of sandstone formations is a challenging task, which involves several chemicals and physical interactions of the acid with the formation. Some of these reactions may result in formation damage. Mud acid has been successfully used to stimulate sandstone reservoirs for a number of years. It is a mixture of hydrofluoric (HF and hydrochloric (HCl acids designed to dissolve clays and siliceous fines accumulated in the near-wellbore region. Matrix acidizing may also be used to increase formation permeability in undamaged wells. The change may be up to 50% to 100% with the mud acid. For any acidizing process, the selection of acid (Formulation and Concentration and the design (Pre-flush, Main Acid, After-flush is very important. Different researchers are using different combinations of acids with different concentrations to get the best results for acidization. Mainly the common practice is combination of Hydrochloric Acid – Hydrofluoric with Concentration (3% HF – 12% HCl. This paper presents the results of a laboratory investigation of Orthophosphoric acid instead of hydrochloric acid in one combination and the second combination is Fluoboric and formic acid and the third one is formic and hydrofluoric acid. The results are compared with the mud acid and the results calculated are porosity, permeability, and FESEM Analysis and Strength tests. All of these new combinations shows that these have the potential to be used as acidizing acids on sandstone formations.

  8. An Efficient Procedure for Esterification of Aryloxyacetic Acid and Arylthioacetic Acid Catalyzed by Silica Sulfuric Acid

    LI,Hong-Ya; LI,Ji-Tai; LI,Hui-Zhang

    2004-01-01

    @@ Aryloxyacetate and arylthioacetate are wildly used in herbicides, plant regulator and insecticides. Recently, Wille et al. have reported that methyl aryloxyacetate is an efficient agent to prevent and treat allergic contact dermatitis.[1] The most popular synthesis is by heating sodium phenoxide (mercaptide) with ethyl chloroacetate in DMF,[2] or by the esterification of acid with alcohol using concentrated H2SO4 as catalyst.[3] In this paper, synthesis of aryloxyacetate and aryl thioacetate from aryloxyacetic acid and arylthioacetic acid respectively in ether catalyzed by silica sulfuric acid in 83%~94% yields is described. The catalyst is reused for 3 times without significant loss of activity (Entry 4). Compared with common procedures, the present procedure possesses the advantages of the operational simplicity, short reaction time,less-corrosion, high yield and reusable catalyst.

  9. Maleic acid and succinic acid in fermented alcoholic beverages are the stimulants of gastric acid secretion

    Teyssen, Stephan; González-Calero, Gloria; Schimiczek, Michael; Singer, Manfred V.

    1999-01-01

    Alcoholic beverages produced by fermentation (e.g., beer and wine) are powerful stimulants of gastric acid output and gastrin release in humans. The aim of this study was to separate and specify the gastric acid stimulatory ingredients in alcoholic beverages produced by fermentation. Yeast-fermented glucose was used as a simple model of fermented alcoholic beverages; it was stepwise separated by different methods of liquid chromatography, and each separated solution was tested in human volunt...

  10. Diagnostic value of glycocholic acid for intrahepatic cholestasis in pregnancy

    The content of glycocholic acid (CG) in pregnant women's sera is detected with CG radioimmunoassay (RIA). The content of CG in sera of normal pregnant women after 32 weeks is ascended slightly with the increasing of pregnant month. It is less than 7.0 μmol/l before 31 weeks in pregnancy and less than 9.4 μmol/l after 32 weeks. The serum CG content of patients with intrahepatic cholestasis in pregnancy (ICP) is increased by 100%. The CG value of about half patients appears earlier than pruritus and ALT rise, the earliest CG increasing appears in the 20th pregnant week. It is the most sensitive method for ICP early diagnosis. 136 cases of ICP patients are observed and the results show that the higher the CG content, the higher the rate of intrauterine fetal anoxia; therefore, the dynamic observation of CG content in ICP patients is a dependable objective for surveillance fetal prognosis

  11. Thermal Stability of Acetohydroxamic Acid/Nitric Acid Solutions

    The transmutation of transuranic actinides and long-lived fission products in spent commercial nuclear reactor fuel has been proposed as one element of the Advanced Accelerator Applications Program. Preparation of targets for irradiation in an accelerator-driven subcritical reactor would involve dissolution of the fuel and separation of uranium, technetium, and iodine from the transuranic actinides and other fission products. The UREX solvent extraction process is being developed to reject and isolate the transuranic actinides in the acid waste stream by scrubbing with acetohydroxamic acid (AHA). To ensure that a runaway reaction will not occur between nitric acid and AHA, an analogue of hydroxyl amine, thermal stability tests were performed to identify if any processing conditions could lead to a runaway reaction

  12. Structural features of lignohumic acids

    Novák, František; Šestauberová, Martina; Hrabal, Richard

    2015-08-01

    The composition and structure of humic acids isolated from lignohumate, which is produced by hydrolytic-oxidative conversion of technical lignosulfonates, were characterized by chemical and spectral methods (UV/VIS, FTIR, and 13C NMR spectroscopy). As comparative samples, humic acids (HA) were isolated also from lignite and organic horizon of mountain spruce forest soil. When compared with other HA studied, the lignohumate humic acids (LHHA) contained relatively few carboxyl groups, whose role is partly fulfilled by sulfonic acid groups. Distinctive 13C NMR signal of methoxyl group carbons, typical for lignin and related humic substances, was found at the shift of 55.9 ppm. Other alkoxy carbons were present in limited quantity, like the aliphatic carbons. Due to the low content of these carbon types, the LHHA has high aromaticity of 60.6%. Comparison with the natural HA has shown that lignohumate obtained by thermal processing of technical lignosulfonate can be regarded as an industrially produced analog of natural humic substances. Based on the chemical and spectral data evaluation, structural features of lignohumate humic acids were clarified and their hypothetical chemical structure proposed, which described typical "average" properties of the isolated fraction.

  13. Branched-Chain Amino Acids

    Matteo Ghiringhelli

    2015-07-01

    Full Text Available Our study is focused on evaluation and use of the most effective and correct nutrients. In particular, our attention is directed to the role of certain amino acids in cachectic patients.During parenteral nutrition in humans, physician already associates in the PN-bags different formulations including amino acids, lipids and glucose solutions or essential amino acids solution alone or exclusively branched-chain amino acids (BCAA. Studies investigated the effects of dietary BCAA ingestion on different diseases and conditions such as obesity and metabolic disorders, liver disease, muscle atrophy, cancer, impaired immunity or injuries (surgery, trauma, burns, and sepsis. BCAAs have been shown to affect gene expression, protein metabolism, apoptosis and regeneration of hepatocytes, and insulin resistance. They have also been shown to inhibit the proliferation of liver cancer cells in vitro, and are essential for lymphocyte proliferation and dendritic cell maturation. Oral or parenteral administration of these three amino acids will allow us to evaluate the real efficacy of these compounds during a therapy to treat malnutrition in subjects unable to feed themselves.

  14. Fixation Status of Acid Soils

    Six acid soil series from different benchmark sites; Rangsit soil (Sulfic Tropaquepts) (two acid sulfate soils), Pakchong soil (Oxic Paleustults) Korat soil (Oxic Paleustults), Warin soil (Oxic Paleustults), Mae Taeng soil (Typic paleustults) and Boundary grey soil and two Thai phosphate rocks (P R) (Lampun P R and Ratchabuie P R) had been characterized in the laboratory by isotope techniques (E, value Part 1). Triple superphosphate (TSP) was used as a standard fertilizer. R P and TSP with 50 mg P Kg-1 soil were incubated for 30 days to examine the fixing capacity of the acid soils. The results showed that Rangsit Soil which is acid sulfate had high fixing capacity. Pakchong soil retained higher P fixation ability than Korat and Warin soil series. The highest fixation capacity among 7 acid soils were Grey Soil and Mae Taeng soil series. The solubility of TSP was decreased when incorporated with soil after incubation for 30 days. P R from Ratchaburi showed higher effectiveness than Lamphun P R

  15. Protein crystallographic studies of CoA-dependent proteins: new insight into the binding mode and exchange mechanism of acyl-CoA

    Taskinen, J. (Jukka)

    2006-01-01

    Abstract Multifunctional enzyme type 1 (MFE-1) is a monomeric member of the hydratase/isomerase superfamily (H/I) involved in the β-oxidation of fatty acids. MFE-1 has 2-enoyl-CoA hydratase-1, Δ3-Δ2-enoyl-CoA isomerase, and several other enoyl-CoA isomerase activities at the N-terminus. The C-terminus has (3S)-hydroxyacyl-CoA dehydrogenase activity. MFE-1 can also convert certain hydroxylated C27 bile acid synthesis intermediates. In these studies, a domain assignment of MFE-1 by sequ...

  16. Conjugated Linoleic Acid Accumulation via 10-Hydroxy-12-Octadecaenoic Acid during Microaerobic Transformation of Linoleic Acid by Lactobacillus acidophilus

    Ogawa, Jun; Matsumura, Kenji; Kishino, Shigenobu; Omura, Yoriko; Shimizu, Sakayu

    2001-01-01

    Specific isomers of conjugated linoleic acid (CLA), a fatty acid with potentially beneficial physiological and anticarcinogenic effects, were efficiently produced from linoleic acid by washed cells of Lactobacillus acidophilus AKU 1137 under microaerobic conditions, and the metabolic pathway of CLA production from linoleic acid is explained for the first time. The CLA isomers produced were identified as cis-9, trans-11- or trans-9, cis-11-octadecadienoic acid and trans-9, trans-11-octadecadie...

  17. Definition of a Dependent Child

    Human Resources Department

    2005-01-01

    The Department of Human Resources wishes to remind members of the personnel that, under the provisions of § 6 of Administrative Circular No. 5 “Dependent child”, in the case of a child over 18 years of age the status of dependent child comes to an end once a course of studies is completed. Consequently, the payment of the dependent child allowance and the child's membership of the CERN Health Insurance Scheme terminate with effect from the last day of the month in which the course of study concerned ends. In this connection, members of the personnel are reminded that children who are no longer dependent according to the Staff Rules and Regulations and who are less than 26 years of age can nevertheless opt for membership of the normal health insurance under the terms and conditions laid down in the CERN Health Insurance Rules. The Department of Human Resources also wishes to remind members of the personnel that, pursuant to Article R IV 1.17 of the Staff Regulations, a member of the personnel is requ...

  18. A Dependency Parser for Tweets

    Kong, Lingpeng; Schneider, Nathan; Swayamdipta, Swabha; Bhatia, Archna; Dyer, Chris; Smith, Noah A.

    2014-01-01

    We describe a new dependency parser for English tweets, TWEEBOPARSER. The parser builds on several contributions: new syntactic annotations for a corpus of tweets (TWEEBANK), with conventions informed by the domain; adaptations to a statistical parsing algorithm; and a new approach to exploiting out-of-domain Penn Treebank data. Our experiments show that the parser achieves over 80% unlabeled attachment accuracy on our new, high-quality test set and measure the benefit of our contributions.Ou...

  19. New nalidixic acid resistance mutations related to deoxyribonucleic acid gyrase activity.

    Yamagishi, J; Furutani, Y; Inoue, S.; Ohue, T; Nakamura, S; Shimizu, M

    1981-01-01

    In Escherichia coli K-12 mutants which had a new nalidixic acid resistance mutation at about 82 min on the chromosome map, cell growth was resistant to or hypersusceptible to nalidixic acid, oxolinic acid, piromidic acid, pipemidic acid, and novobiocin. Deoxyribonucleic acid gyrase activity as tested by supercoiling of lambda phage deoxyribonucleic acid inside the mutants was similarly resistant or hypersusceptible to the compounds. The drug concentrations required for gyrase inhibition were ...

  20. 49 CFR 173.158 - Nitric acid.

    2010-10-01

    ... 2.5 L (0.66 gallon) capacity each. (f) Nitric acid of 70 percent or less concentration, when offered... 49 Transportation 2 2010-10-01 2010-10-01 false Nitric acid. 173.158 Section 173.158... Nitric acid. (a) Nitric acid exceeding 40 percent concentration may not be packaged with any...

  1. Veal fatty acid composition of different breeds

    Ivica Kos; Jelena Ramljak; Ante Ivanković; Miljenko Konjačić; Nikolina Kelava

    2010-01-01

    Veal fatty acid composition in M. Longissimus thoracis was investigated in different calf breeds (Simmental, Holstein, Simmental x Holstein). Calves were reared on the same farm under identical feeding and handling conditions. Simmental calves had higher polyunsaturated fatty acid (PUFA) but lower saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) values than Holstein and crossbreed calves (P

  2. How does Listeria monocytogenes combat acid conditions?

    Listeria monocytogenes, a major foodborne pathogen, possesses a number of mechanisms which enable it to combat the challenges posed by acidic environments such as acidic foods and the acidity in the gastrointestinal tract. These mechanisms include the acid tolerance response, a two-component regula...

  3. 21 CFR 184.1061 - Lactic acid.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactic acid. 184.1061 Section 184.1061 Food and... Substances Affirmed as GRAS § 184.1061 Lactic acid. (a) Lactic acid (C3H6O3, CAS Reg. Nos.: dl mixture, 598... hydrogen cyanide and subsequent hydrolysis to lactic acid. (b) The ingredient meets the specifications...

  4. Influence of acidified acidity to uranium bioleaching

    The relationship between the acidified acidity and the acid consumption and uranium leaching rate in the process of uranium bioleaching is investigated. Results indicate that higher uranium leaching rate is obtained when the relatively high acidity was applied at beginning. For different minerals, although the original acidity should be different, lower original acidity was not better for shortening leaching period and improving uranium leaching rate. It confirms 30-40 g/L sulfuric acid as the original acidity was more suitable and more than 30 g/ L should be applied if the mineral particle sizes were larger. (authors)

  5. Uranium extraction in phosphoric acid

    Uranium is recovered from the phosphoric liquor produced from the concentrate obtained from phosphorus-uraniferous mineral from Itataia mines (CE, Brazil). The proposed process consists of two extraction cycles. In the first one, uranium is reduced to its tetravalent state and then extracted by dioctylpyrophosphoric acid, diluted in Kerosene. Re-extraction is carried out with concentrated phosphoric acid containing an oxidising agent to convert uranium to its hexavalent state. This extract (from the first cycle) is submitted to the second cycle where uranium is extracted with DEPA-TOPO (di-2-hexylphosphoric acid/tri-n-octyl phosphine oxide) in Kerosene. The extract is then washed and uranium is backextracted and precipitated as commercial concentrate. The organic phase is recovered. Results from discontinuous tests were satisfactory, enabling to establish operational conditions for the performance of a continuous test in a micro-pilot plant. (Author)

  6. Nitric Acid Poisoning: Case Report

    Nitric acid (HNO3) is a corrosive fluid that, when in contact with reducing agents, generates nitrogen oxides that are responsible for inhalation poisoning. We present two cases of poisoning from nitric acid gas inhalation resulting from occupational exposure. Imaging findings were similar in both cases, consistent with adult respiratory distress syndrome (ARDS): bilaterally diffuse alveolar opacities on the chest X-ray and a cobblestone pattern on computed tomography (CT).one of the patients died while the other evolved satisfactorily after treatment with n-acetyl cysteine and mechanical ventilation. The diagnosis of nitric acid poisoning was made on the basis of the history of exposure and the way in which the radiological findings evolved.

  7. Toxicologic Study of Monochloroacetic Acid

    Lu Bo; Zhan Ping

    2006-01-01

    @@ Monochloroacetic Acid (MCA) is a chlorinated analog of acetic acids. MCA and its sodium salt (SMCA) are widely used as a chemical intermediate (primarily in the manufacture of chlorophenoxy herbicides,carboxymethylcelluose, glycine and indigoid dyes).Moreover, MCA has been found as a common by-product of the chlorination of drinking water. Chloroacetates are ubiquitous in the environment, and MCA is the most abundant among chloroacetates. A background level of 0.1 - 1μg/L is expected to occur in precipitation[1]. Total world wide annual production of MCA reported was about 400 000 tons[2]. Many studies have showed that MCA not only caused acute or chronic damage to the skin , liver, kidney, heart, brain and other organs, but also caused acute death systemically under high concentration[2,3]. So this article will discuss the toxic effect of Monochloroacetic Acid in Toxicology.

  8. Tumor Acidity as Evolutionary Spite

    Most cancer cells shift their metabolic pathway from a metabolism reflecting the Pasteur-effect into one reflecting the Warburg-effect. This shift creates an acidic microenvironment around the tumor and becomes the driving force for a positive carcinogenesis feedback loop. As a consequence of tumor acidity, the tumor microenvironment encourages a selection of certain cell phenotypes that are able to survive in this caustic environment to the detriment of other cell types. This selection can be described by a process which can be modeled upon spite: the tumor cells reduce their own fitness by making an acidic environment, but this reduces the fitness of their competitors to an even greater extent. Moreover, the environment is an important dimension that further drives this spite process. Thus, diminishing the selective environment most probably interferes with the spite process. Such interference has been recently utilized in cancer treatment

  9. The acid rain differential game

    Countries emit sulphur which is partly transferred to other countries. Depositions above critical loads ultimately destroy the soil. Countries face a trade-off between the costs of emission reductions and the damage to the soil due to the depletion of the acid buffers. Because of the transboundary externalities the outcome will depend on whether the countries cooperate or not. This paper presents the cooperative outcome and the open-loop and Markov-perfect Nash equilibria of the acid rain differential game. It will be shown that the depositions always converge to the critical loads but the steady-state levels of the buffer stocks differ. The theory is used to analyse the acid rain differential game for sulphur between Great Britain and Ireland. Finally, some results are given for the whole of Europe. 20 refs

  10. Fusidic acid betamethasone lipid cream.

    Girolomoni, G; Mattina, R; Manfredini, S; Vertuani, S; Fabrizi, G

    2016-05-01

    Bacterial infections of the skin and soft tissues are frequent disorders. They can be primitive infections (e.g. impetigo, folliculitis) or secondary infections complicating other diseases, particularly atopic dermatitis. The most common aetiologic agent is Staphylococcus aureus. Topical antibiotic therapy may be sufficient in many instances to control these infections. Fusidic acid is an antibiotic used topically on the skin which is very active against S. aureus, including methicillin-resistant strains, and other Gram-positive bacteria. Resistance rates to fusidic acid are stably low. A fusidic acid and betamethasone formulation in a lipid-enriched cream (lipid cream) has been recently developed in order to provide effective antibacterial and anti-inflammatory activities in conjunction with a powerful emollient and moisturising effect. This preparation may be especially useful in patients with atopic-infected eczema. PMID:27121235

  11. Solid–liquid equilibria measurements for binary systems comprising (butyric acid + propionic or pentanoic acid) and (heptanoic acid + propionic or butyric or pentanoic or hexanoic acid)

    Highlights: ► Binary SLE measurement for butyric acid + {propionic or pentanoic acid}. ► Binary SLE measurements for heptanoic acid + {propionic or butyric or pentanoic or hexanoic acid}. ► Measurements undertaken using a synthetic method using two new apparati. - Abstract: Solid–liquid equilibria (SLE) measurements have been undertaken for carboxylic acid systems comprising (butyric acid + propionic or pentanoic acid) and (heptanoic acid + propionic or butyric or pentanoic or hexanoic acid) via a synthetic method using two complementary pieces of equipment. The measurements have been obtained at atmospheric pressure and over the temperature range of (225.6 to 270.7) K. All the acid mixtures exhibit a eutectic point in their respective phase diagrams, which have been determined experimentally. The estimated maximum uncertainties in the reported temperatures and compositions are ±1 K and ±0.0006 mole fraction, respectively. The experimental data have been satisfactorily correlated with the Wilson and NRTL activity coefficient models.

  12. Hydroxamic acids in asymmetric synthesis.

    Li, Zhi; Yamamoto, Hisashi

    2013-02-19

    Metal-catalyzed stereoselective reactions are a central theme in organic chemistry research. In these reactions, the stereoselection is achieved predominantly by introducing chiral ligands at the metal catalyst's center. For decades, researchers have sought better chiral ligands for asymmetric catalysis and have made great progress. Nevertheless, to achieve optimal stereoselectivity and to catalyze new reactions, new chiral ligands are needed. Because of their high metal affinity, hydroxamic acids play major roles across a broad spectrum of fields from biochemistry to metal extraction. Dr. K. Barry Sharpless first revealed their potential as chiral ligands for asymmetric synthesis in 1977: He published the chiral vanadium-hydroxamic-acid-catalyzed, enantioselective epoxidation of allylic alcohols before his discovery of Sharpless asymmetric epoxidation, which uses the titanium-tartrate complex as the chiral reagent. However, researchers have reported few highly enantioselective reactions using metal-hydroxamic acid as catalysts since then. This Account summarizes our research on metal-catalyzed asymmetric epoxidation using hydroxamic acids as chiral ligands. We designed and synthesized a series of new hydroxamic acids, most notably the C2-symmetric bis-hydroxamic acid (BHA) family. V-BHA-catalyzed epoxidation of allylic and homoallylic alcohols achieved higher activity and stereoselectivity than Sharpless asymmetric epoxidation in many cases. Changing the metal species led to a series of unprecedented asymmetric epoxidation reactions, such as (i) single olefins and sulfides with Mo-BHA, (ii) homoallylic and bishomoallylic alcohols with Zr- and Hf-BHA, and (iii) N-alkenyl sulfonamides and N-sulfonyl imines with Hf-BHA. These reactions produce uniquely functionalized chiral epoxides with good yields and enantioselectivities. PMID:23157425

  13. Production of LPA by autotaxin and toxic phospholipases D : biochemical characterization and physiological implications

    Meeteren, Laurens Arend van

    2007-01-01

    Lysophosphatidic acid (LPA) is a lipid mediator with a wide variety of biological actions, particularly as an inducer of cell proliferation, migration and survival. LPA binds to at least five distinct G protein-coupled receptors and thereby activates multiple signal transduction pathways, including

  14. Sequence Classification: 407089 [

    Full Text Available NSFERASE (1-AGP ACYLTRANSFERASE) (1-AGPAT) (LYSOPHOSPHATIDIC ACID ACYLTRANSFERASE) (LPAAT) || http://www.ncbi.nlm.nih.gov/protein/15828585 ... ...TMB Non-TMH Non-TMB TMB Non-TMB Non-TMB >gi|15828585|ref|NP_325945.1| 1-ACYL-SN-GLYCEROL-3-PHOSPHATE ACYLTRA

  15. Rac controls PIP5K localisation and PtdIns(4,5)P-2 synthesis, which modulates vinculin localisation and neurite dynamics

    J.R. Halstead; N.E. Savaskan; I. van den Bout; F. van Horck; A. Hajdo-Milasinovic; M. Snell; W.J. Keune; J.P.T. Klooster; P.L. Hordijk; N. Divecha

    2010-01-01

    In N1E-115 cells, neurite retraction induced by neurite remodelling factors such as lysophosphatidic acid, sphingosine 1-phosphate and semaphorin 3A require the activity of phosphatidylinositol 4-phosphate 5-kinases (PIP5Ks). PIP5Ks synthesise the phosphoinositide lipid second messenger phosphatidyl

  16. Biophysical properties of phenyl succinic acid derivatised hyaluronic acid

    Neves-Petersen, Maria Teresa; Klitgaard, Søren; Skovsen, Esben;

    2010-01-01

    Modification of hyaluronic acid (HA) with aryl succinic anhydrides results in new biomedical properties of HA as compared to non-modified HA, such as more efficient skin penetration, stronger binding to the skin, and the ability to blend with hydrophobic materials. In the present study, hyaluronic...

  17. Solubilities of Isophthalic Acid in Acetic Acid + Water Solvent Mixtures

    CHENG Youwei; HUO Lei; LI Xi

    2013-01-01

    The solubilities of isophthalic acid (1) in binary acetic acid (2) + water (3) solvent mixtures were determined in a pressurized vessel.The temperature range was from 373.2 to 473.2K and the range of the mole fraction of acetic acid in the solvent mixtures was from x2 =0 to 1.A new method to measure the solubility was developed,which solved the problem of sampling at high temperature.The experimental results indicated that within the temperature range studied,the solubilities of isophthalic acid in all mixtures showed an increasing trend with increasing temperature.The experimental solubilities were correlated by the Buchowski equation,and the calculate results showed good agreement with the experimental solubilities.Furthermore,the mixed solvent systems were found to exhibit a maximum solubility effect on the solubility,which may be attributed to the intermolecular association between the solute and the solvent mixture.The maximum solubility effect was well modeled by the modified Wilson equation.

  18. Enrichment of decanoic acid in cuphea fatty acids via distillation

    The introduction of a new crop often requires the development of new products and purification techniques of either the oil or fatty acids. Most new crops enter the cosmetic market first due to their high rates of returns. However, the cosmetic market often demands high purity and colorless materi...

  19. Acidity of carboxylic acids: a rebuttal and redefinition

    Exner, Otto; Čársky, Petr

    2001-01-01

    Roč. 123, č. 39 (2001), s. 9564-9570. ISSN 0002-7863 R&D Projects: GA ČR GA203/99/1454 Institutional research plan: CEZ:AV0Z4055905 Keywords : carboxylic acids Subject RIV: CC - Organic Chemistry Impact factor: 6.079, year: 2001

  20. Acid Sulfate Alteration on Mars

    Ming, D. W.; Morris, R. V.

    2016-01-01

    A variety of mineralogical and geochemical indicators for aqueous alteration on Mars have been identified by a combination of surface and orbital robotic missions, telescopic observations, characterization of Martian meteorites, and laboratory and terrestrial analog studies. Acid sulfate alteration has been identified at all three landing sites visited by NASA rover missions (Spirit, Opportunity, and Curiosity). Spirit landed in Gusev crater in 2004 and discovered Fe-sulfates and materials that have been extensively leached by acid sulfate solutions. Opportunity landing on the plains of Meridiani Planum also in 2004 where the rover encountered large abundances of jarosite and hematite in sedimentary rocks. Curiosity landed in Gale crater in 2012 and has characterized fluvial, deltaic, and lacustrine sediments. Jarosite and hematite were discovered in some of the lacustrine sediments. The high elemental abundance of sulfur in surface materials is obvious evidence that sulfate has played a major role in aqueous processes at all landing sites on Mars. The sulfate-rich outcrop at Meridiani Planum has an SO3 content of up to 25 wt.%. The interiors of rocks and outcrops on the Columbia Hills within Gusev crater have up to 8 wt.% SO3. Soils at both sites generally have between 5 to 14 wt.% SO3, and several soils in Gusev crater contain around 30 wt.% SO3. After normalization of major element compositions to a SO3-free basis, the bulk compositions of these materials are basaltic, with a few exceptions in Gusev crater and in lacustrine mudstones in Gale crater. These observations suggest that materials encountered by the rovers were derived from basaltic precursors by acid sulfate alteration under nearly isochemical conditions (i.e., minimal leaching). There are several cases, however, where acid sulfate alteration minerals (jarosite and hematite) formed in open hydrologic systems, e.g., in Gale crater lacustrine mudstones. Several hypotheses have been suggested for the

  1. Acid-functionalized polyolefin materials and their use in acid-promoted chemical reactions

    Oyola, Yatsandra; Tian, Chengcheng; Bauer, John Christopher; Dai, Sheng

    2016-06-07

    An acid-functionalized polyolefin material that can be used as an acid catalyst in a wide range of acid-promoted chemical reactions, wherein the acid-functionalized polyolefin material includes a polyolefin backbone on which acid groups are appended. Also described is a method for the preparation of the acid catalyst in which a precursor polyolefin is subjected to ionizing radiation (e.g., electron beam irradiation) of sufficient power and the irradiated precursor polyolefin reacted with at least one vinyl monomer having an acid group thereon. Further described is a method for conducting an acid-promoted chemical reaction, wherein an acid-reactive organic precursor is contacted in liquid form with a solid heterogeneous acid catalyst comprising a polyolefin backbone of at least 1 micron in one dimension and having carboxylic acid groups and either sulfonic acid or phosphoric acid groups appended thereto.

  2. Risk and Health Effect of Boric Acid

    Ang S. See

    2010-01-01

    Full Text Available Problem statement: Boric acid is a pesticide usually used to kill mites, fungi, plants and insect including fleas, termites, cockroaches and wood decay fungi. Besides, it was also used in many fields such as food preservative, in newborn baby’s nurseries and antiseptic. Many reports indicated that boric acid poisoning occurred due to the misuse of household product and illegal use of boric acid in food product. In this study, the concern issue was the usage of boric acid that may lead to boric acid poisoning. Approach: This review had shown some information for boric acid such as its usage, the existent method for detection of boric acid in food. Besides, this review also discussed about the toxicology and pharmacokinetic of boric acid and the health impact of boric acid on human and animal. Result: Previous studies showed that food products such as yellow noodles contain boric acid. The boric acid level in most foods was different among the factory and the production period. It is due to the lack of standard measurement during the processing. Conclusion: Since boric acid was harmful to human health and may cause poisoning, hence, the control and the awareness of the usage of boric acid especially in food should be increased. There are numerous methods available for quantification of boric acid such as mannitol titration technique, colorimetric method. Accordingly, the analysis of boric acid is essential.

  3. Citric Acid Passivation of Stainless Steel

    Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

    2009-01-01

    Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

  4. [Alpha-linolenic acid and cardiovascular diseases].

    Ristić-Medić, Danijela; Ristić, Gordana; Tepsić, Vesna

    2003-01-01

    IMPORTANCE AND METABOLISM OF ALPHA-LINOLENIC ACID: Alpha-linolenic acid is an essential fatty acid which cannot be produced in the body and must be taken by food. Both in animals and humans, alpha-linolenic acid is desaturated and elongated into eicosapentaenoic and docosahexaenoic acid. It is also incorporated into plasma and tissue lipids and its conversion is affected by levels of linoleic acid. POTENTIAL ROLE IN PATHOGENESIS OF CARDIOVASCULAR DISEASES: Diet enriched in n-3 fatty acids, especially alpha-linolenic acid, reduces the incidence of cardiac death. Studies have shown that alpha linolenic acid prevents ventricular fibrillation which is the main cause of cardiac death. Studies in rats suggest that alpha-linolenic acid may be more effective in preventing ventricular fibrillations than eicosapentaenoic and docosahexaenoic acid. Furthermore, alpha-linolenic acid is the main fatty acid decreasing platalet aggregation which is an important step in thrombosis i.e. non-fatal myocardial infarction and stroke. DIETARY SOURCES AND NUTRITION RECOMMENDATIONS: Dietary sources include flaxseed and flaxseed oil, canola oil, soybean and soybean oil, pumpkin seed and pumpkin oil, walnuts and walnut oil. Strong evidence supports beneficial effects of alpha-linolenic acid and its dietary sources should be incorporated into balanced diet for prevention of cardiovascular diseases. The recommended daily intake is 2 g with a ratio of 5/1 for linoleic/alpha-linolenic acid. PMID:15510909

  5. Acid Rain: What It Is -- How You Can Help!

    National Wildlife Federation, Washington, DC.

    This publication discusses the nature and consequences of acid precipitation (commonly called acid rain). Topic areas include: (1) the chemical nature of acid rain; (2) sources of acid rain; (3) geographic areas where acid rain is a problem; (4) effects of acid rain on lakes; (5) effect of acid rain on vegetation; (6) possible effects of acid rain…

  6. Peptide Nucleic Acids Complexes of Two Peptide Nucleic Acid Strands and One

    1999-01-01

    Peptide nucleic acids and analogues of peptide nucleic acids are used to form duplex, triplex, and other structures with nucleic acids and to modify nucleic acids. The peptide nucleic acids and analogues thereof also are used to modulate protein activity through, for example, transcription arrest...

  7. 40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Coco acid triamine condensate... Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid salts. (a... coco acid triamine condensate, poly-car-box-ylic acid salts. (PMN P-92-446) is subject to...

  8. Determination of acetylsalicylic acid and salicylic acid in foods, using HPLC with fluorescence detection.

    Venema, D.P.; Hollman, P.C.H.; Janssen, P.L.T.M.K.; Katan, M.B.

    1996-01-01

    We developed a specific and sensitive HPLC method with fluorescence detection for the determination of free acetylsalicylic acid, free salicylic acid, and free salicylic acid plus salicylic acid after alkaline hydrolysis (free-plus-bound) in foods. Acetylsalicylic acid was detected after postcolumn

  9. Astaxanthin can alter CYP1A-dependent activities via two different mechanisms: induction of protein expression and inhibition of NADPH P450 reductase dependent electron transfer.

    Ohno, Marumi; Darwish, Wageh S; Ikenaka, Yoshinori; Miki, Wataru; Ishizuka, Mayumi

    2011-06-01

    Astaxanthin (Ax), a xanthophyll carotenoid, is reported to induce cytochrome P450 (CYP) 1A-dependent activity. CYP1A is one of the most important enzymes participating in phase I metabolism for chemicals, and it can activate various mutagens. To investigate the effect of Ax on the metabolic activation of a typical promutagen, benzo[a]pyrene by CYP1A, we orally administrated Ax-containing oil (100 mg Ax/kg body weight/day for 3 days) to male Wistar rats. In the treated rat liver, expression of CYP1A1 mRNA, protein, and its activity were significantly increased (5.5-, 8.5-, and 2.5-fold, respectively). In contrast, the activities of phase II enzymes (glutathione S-transferase and glucuronosyl-transferase) were not modulated by Ax-containing oil. As a consequence, the mutagenicity of benzo[a]pyrene was more enhanced in Ax-treated rats, compared with controls in the Ames assay. On the other hand, NADPH P450 reductase activity was decreased in liver microsomes from the treated group. This result suggests the possibility that Ax inhibits the electron supply necessary for CYP catalytic activities and decreases CYP1A activity indirectly. In conclusion, Ax-containing oil intake can alter CYP1A-dependent activities through two different mechanisms: (1) induction of CYP1A1 mRNA, protein expression, and activity; and (2) inhibition of the electron supply for the enzyme. PMID:21414371

  10. Acid evaporation property in chemically amplified resists

    Hashimoto, Shuichi; Itani, Toshiro; Yoshino, Hiroshi; Yamana, Mitsuharu; Samoto, Norihiko; Kasama, Kunihiko

    1997-07-01

    The lithographic performance of a chemically amplified resist system very much depends on the photo-generated acid structure. In a previous paper, we reported the molecular structure dependence of two typical photo-generated acids (aromatic sulfonic acid and alkyl sulfonic acid) from the viewpoints of lithographic performance and acid characteristics such as acid generation efficiency, acid diffusion behavior and acid evaporation property. In this paper, we evaluate the effect of the remaining solvent in a resist film on the acid evaporation property. Four types of two-component chemically amplified positive KrF resists were prepared consisting of tert-butoxycarbonyl (t-BOC) protected polyhydroxystyrene and sulfonic acid derivative photo-acid generator (PAG). Here, a different combination of two types of PAGs [2,4-dimethylbenzenesulfonic acid (aromatic sulfonic acid) derivative PAG and cyclohexanesulfonic acid (alkyl sulfonic acid) derivative PAG] and two types of solvents (propylene glycol monomethyl ether acetate; PGMEA and ethyl lactate; EL) were evaluated. The aromatic sulfonic acid was able to evaporate easily during post exposure bake (PEB) treatment, but the alkyl sulfonic acid was not. The higher evaporation property of aromatic sulfonic acid might be due to the higher vapor pressure and the longer acid diffusion length. Furthermore, the amount of aromatic sulfonic acid in the PGMEA resist was reduced by more than that in the EL resist. The amount of acid loss also became smaller at a higher prebake temperature. The concentration of the remaining solvent in the resist film decreased with the increasing prebake temperature. We think that the acid evaporation property was affected by the remaining solvent in the resist, film; the large amount of remaining solvent promoted the acid diffusion and eventually accelerated the acid evaporation from the resist film surface in the PGMEA resist. In summary, the acid evaporation property depends on both the acid

  11. 2-(3-Hydroxybenzylaminoacetic acid

    Li-Hua Zhi

    2011-07-01

    Full Text Available There are two independent 2-(3-hydroxybenzylaminoacetic acid molecules, C9H11NO3, in the asymmetric unit of the title compound. The dihedral angle between the benzene rings of the two independent molecules is 58.12 (4°. The crystal packing is stablized by intermolecular O—H...O and N—H...O hydrogen bonds.

  12. Hyaluronic acid and tendon lesions

    Kaux, Jean-François; Samson, Antoine; Crielaard, Jean-Michel

    2015-01-01

    Summary Introduction recently, the viscoelastic properties of hyaluronic acid (HA) on liquid connective tissue have been proposed for the treatment of tendinopathies. Some fundamental studies show encouraging results on hyaluronic acid’s ability to promote tendon gliding and reduce adhesion as well as to improve tendon architectural organisation. Some observations also support its use in a clinical setting to improve pain and function. This literature review analyses studies relating to the use of hyaluronic acid in the treatment of tendinopathies. Methods this review was constructed using the Medline database via Pubmed, Scopus and Google Scholar. The key words hyaluronic acid, tendon and tendinopathy were used for the research. Results in total, 28 articles (in English and French) on the application of hyaluronic acid to tendons were selected for their relevance and scientific quality, including 13 for the in vitro part, 7 for the in vivo animal part and 8 for the human section. Conclusions preclinical studies demonstrate encouraging results: HA permits tendon gliding, reduces adhesions, creates better tendon architectural organisation and limits inflammation. These laboratory observations appear to be supported by limited but encouraging short-term clinical results on pain and function. However, controlled randomised studies are still needed. PMID:26958533

  13. Combinatorics of aliphatic amino acids.

    Grützmann, Konrad; Böcker, Sebastian; Schuster, Stefan

    2011-01-01

    This study combines biology and mathematics, showing that a relatively simple question from molecular biology can lead to complicated mathematics. The question is how to calculate the number of theoretically possible aliphatic amino acids as a function of the number of carbon atoms in the side chain. The presented calculation is based on earlier results from theoretical chemistry concerning alkyl compounds. Mathematical properties of this number series are highlighted. We discuss which of the theoretically possible structures really occur in living organisms, such as leucine and isoleucine with a chain length of four. This is done both for a strict definition of aliphatic amino acids only involving carbon and hydrogen atoms in their side chain and for a less strict definition allowing sulphur, nitrogen and oxygen atoms. While the main focus is on proteinogenic amino acids, we also give several examples of non-proteinogenic aliphatic amino acids, playing a role, for instance, in signalling. The results are in agreement with a general phenomenon found in biology: Usually, only a small number of molecules are chosen as building blocks to assemble an inconceivable number of different macromolecules as proteins. Thus, natural biological complexity arises from the multifarious combination of building blocks. PMID:21120449

  14. Abscisic Acid Signaling in Plants

    Vaňková, Radomíra

    NEW YORK : Springer, 2012 - (Ahmad, P.; Prasad, M.), s. 359-368 ISBN 978-1-4614-0633-4 R&D Projects: GA ČR GA522/09/2058 Institutional research plan: CEZ:AV0Z50380511 Keywords : PP2C * PYR/PYL/RCAR proteins * Abscisic acid Subject RIV: ED - Physiology

  15. Antibiofilm Properties of Acetic Acid

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup;

    2014-01-01

    infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram...

  16. An assessment of acid fog

    Airborne particles have long been associated with adverse effects on public health, begin with the notorious air pollution disasters of several decades ago. Although H2SO4 was identified early on as a potential causal factors during these episodes (in part because of concern for potential health effects of particle acidity per se has intensified only recently. Most of the recent aerometric research in the US on acid fog has focused on the ability of clouds and fog to deliver acidity to vegetation and ecosystems. Strong acids are characterized chemically by their pH or H+ concentration. For fog, concentrations are referred to the droplet liquid content; for other (i.e., ''clear air'') aerosols, to the volume of air sampled. A useful measure of the relationship between aerosol and fog is obtained by comparing their mass concentrations on the basis of the same volume of air, by multiplying fogwater concentrations by liquid water content (LWC). This paper reviews fog measurement capability, physical properties and chemistry, and presents a simple urban airshed model which is used to simulate the evolution of fog and aerosol concentrations under urban stagnation conditions

  17. Engineering robust lactic acid bacteria

    Bron, P.A.; Bokhorst-van de Veen, van H.; Wels, M.; Kleerebezem, M.

    2011-01-01

    For centuries, lactic acid bacteria (LAB) have been industrially exploited as starter cultures in the fermentation of foods and feeds for their spoilage-preventing and flavor-enhancing characteristics. More recently, the health-promoting effects of LAB on the consumer have been widely acknowledged,

  18. Uric acid in multiple sclerosis

    Koch, M; De Keyser, J

    2006-01-01

    Peroxynitrite, a reactive oxidant formed by the reaction of nitric oxide with superoxide at sites of inflammation in multiple sclerosis (MS), is capable of damaging tissues and cells. Uric acid, a natural scavenger of peroxynitrite, reduces inflammatory demyelination in experimental allergic encepha

  19. Radiolabeled derivatives of folic acid

    Derivatives of folic acid are described, in which the α-carboxyl group is substituted with an amino compound having an aromatic or heterocyclic ring substituent which is capable of being radiolabelled. Particularly mentioned as a radiolabel is 125I. (author)

  20. Modulating the electronic structure of amino acids: interaction of model lewis acids with anthranilic acid

    Tareq Irshaidat

    2014-01-01

    On the basis of theoretical B3LYP calculations, Yáñez and co-workers (J. Chem. Theory Comput. 2012, 8, 2293) illustrated that beryllium ions are capable of significantly modulating (changing) the electronic structures of imidazole. In this computational organic chemistry study, the interaction of this β-amino acid and five model Lewis acids (BeF1+, Be2+, AlF2(1+), AlF2+, and Al3+) were investigated. Several aspects were addressed: natural bond orbitals, including second order perturbation ana...

  1. Benzylidene Acetal Protecting Group as Carboxylic Acid Surrogate: Synthesis of Functionalized Uronic Acids and Sugar Amino Acids.

    Banerjee, Amit; Senthilkumar, Soundararasu; Baskaran, Sundarababu

    2016-01-18

    Direct oxidation of the 4,6-O-benzylidene acetal protecting group to C-6 carboxylic acid has been developed that provides an easy access to a wide range of biologically important and synthetically challenging uronic acid and sugar amino acid derivatives in good yields. The RuCl3 -NaIO4 -mediated oxidative cleavage method eliminates protection and deprotection steps and the reaction takes place under mild conditions. The dual role of the benzylidene acetal, as a protecting group and source of carboxylic acid, was exploited in the efficient synthesis of six-carbon sialic acid analogues and disaccharides bearing uronic acids, including glycosaminoglycan analogues. PMID:26572799

  2. Omega-3 Fatty Acids and Inflammatory Processes

    Philip C. Calder

    2010-03-01

    Full Text Available Long chain fatty acids influence inflammation through a variety of mechanisms; many of these are mediated by, or at least associated with, changes in fatty acid composition of cell membranes. Changes in these compositions can modify membrane fluidity, cell signaling leading to altered gene expression, and the pattern of lipid mediator production. Cell involved in the inflammatory response are typically rich in the n-6 fatty acid arachidonic acid, but the contents of arachidonic acid and of the n-3 fatty acids eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA can be altered through oral administration of EPA and DHA. Eicosanoids produced from arachidonic acid have roles in inflammation. EPA also gives rise to eicosanoids and these often have differing properties from those of arachidonic acid-derived eicosanoids. EPA and DHA give rise to newly discovered resolvins which are anti-inflammatory and inflammation resolving. Increased membrane content of EPA and DHA (and decreased arachidonic acid content results in a changed pattern of production of eicosanoids and resolvins. Changing the fatty acid composition of cells involved in the inflammatory response also affects production of peptide mediators of inflammation (adhesion molecules, cytokines etc.. Thus, the fatty acid composition of cells involved in the inflammatory response influences their function; the contents of arachidonic acid, EPA and DHA appear to be especially important. The anti-inflammatory effects of marine n-3 PUFAs suggest that they may be useful as therapeutic agents in disorders with an inflammatory component.

  3. Digestion and absorption of lipids and bile acids in sheep fed stearic acid, oleic acid, or tristearin

    Sheep were fed diets containing 7.5% added stearic acid, oleic acid, or tristearin for 21 days. In addition, 50 microCi/kg cerium-141 was included for the last 10 days on experimental diets as an unabsorbed reference substance. In the rumen dietary triglycerides were approximately 50% hydrolyzed, and hydrogenation resulted in saturation of the free fatty acid fraction. Some net synthesis of phospholipids, presumably microbial phospholipids, occurred in the rumen. In the intestine immediately distal to the pylorus, extensive secretion of bile acids, cholesterol, phospholipids, triglycerides, free fatty acids, and lipase occurred. This resulted in doubling of fatty acid fluxes through the duodenum. These endogenous secretions were reabsorbed rapidly however, with the major site of lipid and bile acid absorption in the region .6 to 4 m distal to the pylorus. Additional but less absorption occurred in the more distal segments of the small intestine. Overall absorption of stearic acid, oleic acid, and tristearin supplements was in the range 60 to 70%, and no differences were apparent between fats. Unsaturated fatty acids were over 90% absorbed as compared with 55 to 65% for saturated fatty acids. No significant effect of any of the supplements was observed on ruminal total volatile fatty acids, ratios of volatile fatty acids, or on overall cellulose or caloric digestion

  4. Crystal growth and physical characterization of picolinic acid cocrystallized with dicarboxylic acids

    Somphon, Weenawan; Haller, Kenneth J.

    2013-01-01

    Pharmaceutical cocrystals are multicomponent materials containing an active pharmaceutical ingredient with another component in well-defined stoichiometry within the same unit cell. Such cocrystals are important in drug design, particularly for improving physicochemical properties such as solubility, bioavailability, or chemical stability. Picolinic acid is an endogenous metabolite of tryptophan and is widely used for neuroprotective, immunological, and anti-proliferative effects within the body. In this paper we present cocrystallization experiments of a series of dicarboxylic acids, oxalic acid, succinic acid, DL-tartaric acid, pimelic acid, and phthalic acid, with picolinic acid. Characterization by FT-IR and Raman spectroscopy, DSC and TG/DTG analysis, and X-ray powder diffraction show that new compounds are formed, including a 1:1 picolinium tartrate monohydrate, a 2:1 monohydrate adduct of picolinic acid and oxalic acid, and a 2:1 picolinic acid-succinic acid monohydrate cocrystal.

  5. Acidic lakes and streams in the United States: The role of acidic deposition

    A statistically designed survey of lakes and streams in acid-sensitive areas of the United States, the National Surface Water Survey (NSWS), was used to identify the role of acidic deposition, relative to other factors, in causing acidic conditions in 1,181 lakes and 4,668 streams. Atmospheric deposition is the dominant source of acid anions in 75% of the acidic lakes and 47% of the acidic streams. Organic anions are dominant in one-fourth of the acidic lakes and streams; acidic mine drainage is the dominant acid source in 25% of the acidic streams. Other causes of acidic conditions are relatively unimportant on a regional scale. Nearly all the deposition-dominated acidic systems were found in six well-delineated subpopulations that represent about one-fourth of the NSWS lake population and one-third of the NSWS stream population

  6. Chemical peeling - Glycolic acid versus trichloroacetic acid in melasma

    Kalla G

    2001-01-01

    Full Text Available Melasma continues to be a therapeutic challenge. 100 patients of melasma not responding to conventional depigmenting agents were divided into 2 groups, one treated with 55 - 75% glycolic acid (68 patients and the other with 10-15% trichloroacetic acid (32 patients. Applications were made after every 15 days and response assessed clinically along with relapse or hyperpigmentation after 3 month follow up period. More than 75% improvement was seen in 30%, and 50-75% improvement in 24% patients. Response with TCA was more rapid as compared to GA. Chronic pigmentation responded more favourably to TCA. Relapse and hyperpigmentation was more-25% in TCA as compared to 5.9% GA. Sun exposure was the most important precipitating factor followed by pregnancy and drugs.

  7. Uric Acid Inhibits Placental System A Amino Acid Uptake☆

    Bainbridge, S.A.; von Versen-Höynck, F.; Roberts, J M

    2008-01-01

    Hyperuricemia, a common clinical characteristic of preeclamptic pregnancies, has historically been considered a marker of reduced renal function in preeclamptic women. More recently it has been suggested that uric acid may directly contribute to pathological cell signaling events involved in disease progression as well as maternal and fetal pregnancy outcomes including fetal growth restriction. We hypothesize that the increased frequency of restricted fetal growth seen in relation to increasi...

  8. Endocrine and paracrine role of bile acids

    Verena Keitel, Ralf Kubitz, Dieter Häussinger

    2008-10-01

    Full Text Available Bile acids are not only important for the absorption of dietary lipids and fat soluble vitamins but are signalling molecules with diverse endocrine and paracrine functions. Bile acids regulate bile acid, lipid and glucose metabolism and modulate temperature and energy homeostasis. Furthermore, bile acids can not only promote cell proliferation and liver regeneration but can also induce programmed cell death. Bile acid functions are mediated through different pathways which comprise the activation of nuclear hormone receptors, of intracellular kinases and of the plasma membrane-bound, G-protein coupled bile acid receptor TGR5/Gpbar-1.

  9. Bile acid metabolism in tupaias (lemurs)

    The goal of this work is to study biliary elimination and the metabolism of the most important primary bile acids, cholic acid and chenodesoxycholic acid, and the toxic secondary bile acid, lithocholic acid, which is formed in the intestine as a result of chenodesoxycholate therapy for the dissolving of gall stones. This work herewith offers a contribution to the answering of the question whether tupaias are a relevant animal model for the study of gall stone formation and their medicamentous dissolution by means of bile acids. (orig./MG)

  10. Determination of titratable acidity in white wine

    Rajković Miloš B.; Novaković Ivana D.; Petrović Aleksandar

    2007-01-01

    The amount of titration acid in must is in the largest number of cases with in the range 5.0-8.0 g/dm3. Wines, as a rule, contain less acids than must, and according to Regulations, titratable acidity is in the range of 4.0-8.0 g/dm3 expressed in tartaric acid, because a part of tartaric acid is deposited in the form of salts (tartar or argol) during alcohol fermentation. For wines that contain less than 4 g/dm3 of titratable acids there arises a suspicion about their origin, that is, that du...

  11. Uncarilic Acid and Secouncarilic Acid, Two New Triterpenoids from Uucaria sessilifructus

    Yan Li; De-Qiang Feng; You-Kai Xu; Shang-Gao Liao; Mao-Juan Zhang; Bing Liu; Kai-Long Ji

    2013-01-01

    Two new compounds, the 6-oxo oleanane-type triterpenoid uncarilic acid, and its 5,6-secotriterpenoid derivative, secouncarilic acid, were isolated from the hooks and stems of Uucaria sessilifructus together with seven known ursane-type triterpenoids. Uncarilic acid is the second 6-oxo oleanane-type triterpenoid ever reported, while secouncarilic acid is the first oleanane-type 5,6-secotriterpenoid. A plausible biosynthetic pathway from uncarilic acid to secouncarilic acid was also postulated....

  12. Oxidation-reduction reactions of simple hydroxamic acids and plutonium(IV) ions in nitric acid

    Carrott, M. J.; Fox, O. D.; LeGurun, G.; Jones, C J; Mason, C; Taylor, Robin; Andrieux, Fabrice; Boxall, Colin

    2008-01-01

    Simple hydroxamic acids such as formo- and aceto-hydroxamic acids have been proposed as suitable reagents for the separation of either Pu and/or Np from U in modified or single cycle Purex based solvent extraction processes designed to meet the emerging requirements of advanced fuel cycles. The stability of these hydroxamic acids is dominated by their decomposition through acid hydrolysis. Kinetic studies of the acid hydrolysis of formo- and acetohydroxamic acids are reported in the absence a...

  13. Nitric acid uptake by sulfuric acid solutions under stratospheric conditions - Determination of Henry's Law solubility

    Reihs, Christa M.; Golden, David M.; Tolbert, Margaret A.

    1990-01-01

    The uptake of nitric acid by sulfuric acid solutions representative of stratospheric particulate at low temperatures was measured to determine the solubility of nitric acid in sulfuric acid solutions as a function of H2SO4 concentration and solution temperature. Solubilities are reported for sulfuric acid solutions ranging from 58 to 87 wt pct H2SO4 over a temperature range from 188 to 240 K, showing that, in general, the solubility of nitric acid increases with decreasing sulfuric acid concentration and with decreasing temperature. The measured solubilities indicate that nitric acid in the global stratosphere will be found predominantly in the gas phase.

  14. A Dependence Study of $\\Xi^{*0}$ and $\\bar{\\Xi}^{*0}$ in 250 GeV/c $\\pi^-$. $K^-$ -nucleon Interactions

    Seixas de Rezende, Fabio Antonio; /Rio de Janeiro, CBPF

    2005-04-01

    A direct measurement of the mass number (A) dependence of the production of the hyperon {Xi}*{sup 0} and its opposite {bar {Xi}}*{sup 0} in {pi}{sup -}, K{sup -} beam-nucleon interactions at 250 GeV/c is reported. The data derive from the experiment E769 at Fermilab. The results were obtained for different targets: Be, Al, Cu and W. It was observed the data are found to be well described by the parametrization {sigma}{sub A} = {sigma}{sub 0}A{sup {alpha}}, {alpha} being calculated for different beams. The results obtained are compared with those results of E769 experiment. The results shown here are preliminary.

  15. Complex formation of calcium with humic acid and polyacrylic acid

    In order to understand the migration behavior of radionuclides in the underground, it is also important to estimate the effect of the competing cations originally present in the groundwater. In this connection, the complexation of Ca(II) with Aldrich humic acid has been examined. For the study at trace concentrations (∝ 10-10 M) of Ca(II), the solvent extraction of 45Ca with TTA and TOPO in cyclohexane has been used. At macro concentrations (10-4 M) of Ca(II), the measurement of the free Ca2+ ion concentration with a calcium selective electrode has been conducted. To estimate the polyelectrolyte effect of humic acid separately from its heterogeneous composition effect, polyacrylic acid ([-CH2CH(COOH)-]n) has been selected as a representative of the homogeneous polymeric weak acids and its complexation with Ca(II) has also been examined. The values of log βα have been obtained at pH 5 ∝ 7 in 0.1, 0.4 and 1.0 M NaCl, where βα is the apparent formation constants defined by βα = [ML]/([M][R]). In this definition, [ML] and [M] are the concentrations of bound and free Ca2+ respectively, [R] is the concentration of dissociated proton exchanging sites. log βα of humate decreases from 2.19 ∝ 2.92 (depending on pH and ionic strength 1.0 α of polyacrylate (1.36 ∝ 3.24 for I = 0.1 ∝ 1.0). For both humate and polyacrylate, log βα decreases linearly with log[Na+], where [Na+] is the bulk concentration of sodium ion. Their dependences of log βα on ionic strength are stronger than those of log β of monomeric carboxylates such as oxalate and EDTA, indicating the large electrostatic effect of crowded negative charges on the macromolecules of humic or polyacrylic acid. (orig.)

  16. Thermochemistry of aqueous pyridine-3-carboxylic acid (nicotinic acid)

    Goncalves, Elsa M. [Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade de Lisboa, 1749-016 Lisboa (Portugal); Instituto Politecnico de Setubal, ESTBarreiro, Rua Americo da Silva Marinho, 2839-001 Lavradio (Portugal); Rego, Talita S. [Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade de Lisboa, 1749-016 Lisboa (Portugal); Minas da Piedade, Manuel E., E-mail: memp@fc.ul.p [Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade de Lisboa, 1749-016 Lisboa (Portugal)

    2011-06-15

    Research highlights: {yields} We determined the {Delta}{sub sol}H{sub m} of solid nicotinic acid (NA) in water by solution calorimetry. {yields} We determined {Delta}{sub dil}H{sub m} of an aqueous nicotinic acid solution by flow calorimetry. {yields} We determined (aq, {infinity}) for the 3 NA species involved in acid/base equilibria. {yields} We determined the enthalpy of formation of NA(aq) under saturation conditions.. - Abstract: The molar enthalpy of solution of solid nicotinic acid (NA) at T = 298.15 K, to give an aqueous solution of molality m = 3.748 . 10{sup -3} mol {center_dot} kg{sup -1}, was determined as {Delta}{sub sol}H{sub m} = (19,927 {+-} 48) J {center_dot} mol{sup -1}, by solution calorimetry. Enthalpies of dilution, {Delta}{sub dil}H{sub m}, of 0.1005 mol {center_dot} kg{sup -1} aqueous nicotinic acid to yield final solutions with molality in the approximate range (0.03 to 0.09) mol {center_dot} kg{sup -1} were also measured by flow calorimetry. Combining the two sets of data and the results of pH measurements, with values of proton dissociation enthalpies and {Delta}{sub f}H{sub m}{sup 0}(NA, cr) selected from the literature, it was possible to derive the standard molar enthalpies of formation of the three nicotinic acid species involved in protonation/deprotonation equilibria, at infinite dilution: {Delta}{sub f}H{sub m}{sup 0}(HN{sup +}C{sub 5}H{sub 4}COOH.{infinity}H{sub 2}O,aq) = (328.2 {+-} 1.2) kJ {center_dot} mol{sup -1}, {Delta}{sub f}H{sub m}{sup 0}(HN{sup +}C{sub 5}H{sub 4}COO{sup -}.{infinity}H{sub 2}O,aq) = (325.0 {+-} 1.2) kJ {center_dot} mol{sup -1}, and {Delta}{sub f}H{sub m}{sup 0}(NC{sub 5}H{sub 4}COO{sup -}.{infinity}H{sub 2}O,aq) = (313.7 {+-} 1.2) kJ {center_dot} mol{sup -1}. Finally, the enthalpy of solution of nicotinic acid at T = 298.15 K, under saturation conditions (m = 0.138 mol {center_dot} kg{sup -1}), and the standard molar enthalpy of formation of the corresponding solution could also be obtained as {Delta

  17. Increase of betulinic acid production in Saccharomyces cerevisiae by balancing fatty acids and betulinic acid forming pathways.

    Li, Jing; Zhang, Yansheng

    2014-04-01

    Betulinic acid is a plant-based triterpenoid that has been recognized for its antitumor and anti-HIV activities. The level of betulinic acid in its natural hosts is extremely low. In the present study, we constructed betulinic acid biosynthetic pathway in Saccharomyces cerevisiae by metabolic engineering. Given the betulinic acid forming pathways sharing the common substrate acetyl-CoA with fatty acid synthesis, the metabolic fluxes between the two pathways were varied by changing gene expressions, and their effects on betulinic acid production were investigated. We constructed nine S. cerevisiae strains representing nine combinations of the flux distributions between betulinic acid and fatty acid pathways. Our results demonstrated that it was possible to improve the betulinic acid production in S. cerevisiae while keeping a desirable growth phenotype by optimally balancing the carbon fluxes of the two pathways. Through modulating the expressions of the key genes on betulinic acid and fatty acid pathways, the difference in betulinic acid yield varied largely in the range of 0.01-1.92 mg L(-1) OD(-1). The metabolic engineering approach used in this study could be extended for synthesizing other triterpenoids in S. cerevisiae. PMID:24389702

  18. Effect of supplementation of arachidonic acid (AA) or a combination of AA plus docosahexaenoic acid on breastmilk fatty acid composition

    Smit, EN; Koopmann, M; Boersma, ER; Muskiet, FAJ

    2000-01-01

    We investigated whether supplementation with arachidonic acid (20:4 omega 6; AA), ora combination of AA and docosahexaenoic acid (22:6 omega 3; DHA) would affect human milk polyunsaturated fatty acid (PUFA) composition. Ten women were daily supplemented with 300 mg AA, eight with 300 mg AA, 110 mg e

  19. Palmitic Acid and Health: Introduction.

    Agostoni, Carlo; Moreno, Luis; Shamir, Raanan

    2016-09-01

    Interest in the dietary role and metabolic effect of saturated fatty acids has been recently renewed on the basis of epidemiologic observations and economical approach to health and well-being. Saturated fats may favorably increase blood HDL-Cholesterol levels without significant changes of the total cholesterol/HDL-Cholesterol ratio. Also, the negative effect of saturated fat on cardiovascular diseases risk has recently been challenged. Palmitic acid, among all, may have special structural and functional roles in utero and in infancy, and indeed is it is being delivered in a unique form in human milk. Future research should include objective cost-benefit analyses when disentangling the role of saturated fats in dietary recommendations. PMID:25764181

  20. [Inherited amino acid transport disorders].

    Igarashi, Y; Tada, K

    1992-07-01

    Disorders due to inherited amino acids transport defect are reviewed. The disorders were categorized into three types of transport defects, namely, brush-border membrane of epithelial cells of small intestine and kidney tubules (Hartnup disease, blue diaper syndrome, cystinuria, iminoglycinuria and lysine malabsorption syndrome), basolateral membrane (lysinuric protein intolerance) and membrane of intracellular organelles (cystinosis and hyperornitinemia-hyperammonemia-homocitrullinuria syndrome). Pathogenesis, clinical feature, laboratory findings, diagnosis, genetics and treatment of these disorders are described, briefly. There is not much data for the transport systems themselves, so that further investigation in molecular and gene levels for transport systems is necessary to clarify the characteristics of the transport and heterogeneity of phenotypes in inherited amino acids transport disorders. PMID:1404888

  1. Europium complexes with trifluoroacetic acid

    Synthesis conditions and spectra-luminescent properties of different-ligand europium complexes of the composition Eu (TFA)2x2D, where TFA = anion of trifluoroacetic acid, D = 1,10-phenanthroline, 2,2-dipyridyl, triphenylphosphinoxide, hexamethyl-phosphotriamide, were studied. The compounds prepared have been characterized by the methods of elementary chemical analysis, IR and luminescence spectroscopy. It is shown that in the complex compounds two methods of coordination of the acid residue functional groups are realized, i.e. monodentate and bridge functions. The compounds were tested for resistance to UV light effect and to heating in the air. Complex with 2,2-dipyridyl proved the most thermally stable complex in the series studied, its decomposition temperature being 240 deg C

  2. Ursodeoxycholic acid and superoxide anion

    Predrag Ljubuncic; Omar Abu-Salach; Arieh Bomzon

    2005-01-01

    AIM: To investigate the ability of ursodeoxycholic acid (UDCA) to scavenge superoxide anion (O2-).METHODS: We assessed the ability of UDCA to scavenge (O2-) generated by xanthine-xanthine oxidase (X-XO) in a cell-free system and its effect on the rate of O2--induced ascorbic acid (AA) oxidation in hepatic post-mitochondrial supernatants.RESULTS: UDCA at a concentration as high as 1 mmol/Ldid not impair the ability of the X-XO system to generate O2-, but could scavenge O2- at concentrations of 0.5 and 1 mmol/L, and decrease the rate of AA oxidation at a concentration of 100 μmol/L.CONCLUSION: UDCA can scavenge O2-, an action that may be beneficial to patients with primary biliary cirrhosis.

  3. Production of p-hydroxybenzoic acid from p-coumaric acid by Burkholderia glumae BGR1.

    Jung, Da-Hye; Kim, Eun-Jung; Jung, Eunok; Kazlauskas, Romas J; Choi, Kwon-Young; Kim, Byung-Gee

    2016-07-01

    p-Coumaric acid (pCA) is abundant in biomass with low lignin content, such as straw and stubble from rye, wheat, and barley. pCA can be isolated from biomass and used for the synthesis of aromatic hydrocarbons. Here, we report engineering of the natural pathway for conversion of pCA into p-hydroxybenzoic acid (pHBA) to increase the amount of pHBA that accumulates more than 100-fold. Burkholderia glumae strain BGR1 (BGR1) grows efficiently on pCA as a sole carbon source via a CoA-dependent non-β-oxidation pathway. This pathway removes two carbons from pCA as acetyl-CoA yielding p-hydroxybenzaldehyde and subsequently oxidizes it to pHBA. To increase the amount of accumulated pHBA in BGR1, we first deleted two genes encoding enzymes that degrade pHBA in the β-ketoadipate pathway. At 10 mM of pCA, the double deletion mutant BGR1_PB4 (Δphb3hΔbcl) accumulated pHBA with 95% conversion, while the control BGR1 accumulated only with 11.2% conversion. When a packed bed reactor containing immobilized BGR1_PB4 cells was operated at a dilution rate 0.2 h(-1) , the productivity of pHBA was achieved at 9.27 mg/L/h for 134 h. However, in a batch reactor at 20 mM pCA, growth of BGR1_PB4 was strongly inhibited, resulting in a low conversion of 19.3%. To further increase the amount of accumulated pCA, we identified the first enzyme in the pathway, p-hydroxcinnmaoyl-CoA synthetase II (phcs II), as the rate-limiting enzyme. Over expression of phcs II using a Palk promoter in a batch reaction at 20 mM of pCA yielded 99.0% conversion to pHBA, which is the highest concentration of pHBA ever reported using a biological process. Biotechnol. Bioeng. 2016;113: 1493-1503. © 2015 Wiley Periodicals, Inc. PMID:26693833

  4. Nucleic Acid Aptamers Against Proteases

    Dupont, D M; Andersen, L M; Bøtkjær, Kenneth Alrø; Andreasen, P A

    2011-01-01

    Proteases are potential or realized therapeutic targets in a wide variety of pathological conditions. Moreover, proteases are classical subjects for studies of enzymatic and regulatory mechanisms. We here review the literature on nucleic acid aptamers selected with proteases as targets. Designing small molecule protease inhibitors of sufficient specificity has proved a daunting task. Aptamers seem to represent a promising alternative. In our review, we concentrate on biochemical mechanisms of...

  5. Ions in hyaluronic acid solutions

    Horkay, Ferenc; Basser, Peter J.; Londono, David J.; Hecht, Anne-Marie; Geissler, Erik

    2009-01-01

    Hyaluronic acid (HA) is an anionic biopolymer that is almost ubiquitous in biological tissues. An attempt is made to determine the dominant features that account for both its abundance and its multifunctional role, and which set it apart from other types of biopolymers. A combination of osmotic and scattering techniques is employed to quantify its dynamic and static properties in near-physiological solution conditions, where it is exposed both to mono- and divalent counterions. An equation of...

  6. Rechargeable lead-acid batteries.

    1990-09-01

    Batteries used in medical equipment, like their counterparts in consumer products, attract little attention until they fail to function effectively. In some applications, such as in emergency medical devices, battery failure can have fatal consequences. While modern batteries are usually quite reliable, ECRI has received 53 written problem reports and countless verbal reports or questions related to battery problems in hospitals during the past five years. This large number of reports is due, at least in part, to the enormous quality of batteries used to operate or provide backup power in contemporary hospital equipment. As part of an ongoing evaluation of rehabilitation assistive equipment, ECRI has been studying the performance of 12 V rechargeable deep-cycle lead-acid batteries used in powered wheelchairs. During the course of this evaluation, it has become apparent that many professionals, both clinical and industrial, regard batteries as "black box" devices and know little about proper care and maintenance--and even less about battery selection and purchase. Because equipment performance and reliability can be strongly influenced by different battery models, an understanding of battery characteristics and how they affect performance is essential when selecting and purchasing batteries. The types of rechargeable batteries used most commonly in hospitals are lead-acid and nickel-cadmium (nicad), which we compare below; however, the guidance we provide in this article focuses on lead-acid batteries. While the examples given are for high-capacity 12 V deep-cycle batteries, similar analyses can be applied to smaller lead-acid batteries of different voltages. PMID:2211174

  7. Perfluorooctanoic Acid for Shotgun Proteomics

    Kadiyala, Chandra Sekhar Rao; Tomechko, Sara E.; Miyagi, Masaru

    2010-01-01

    Here, we describe the novel use of a volatile surfactant, perfluorooctanoic acid (PFOA), for shotgun proteomics. PFOA was found to solubilize membrane proteins as effectively as sodium dodecyl sulfate (SDS). PFOA concentrations up to 0.5% (w/v) did not significantly inhibit trypsin activity. The unique features of PFOA allowed us to develop a single-tube shotgun proteomics method that used all volatile chemicals that could easily be removed by evaporation prior to mass spectrometry analysis. ...

  8. Electrochemical analysis of nucleic acids

    Paleček, Emil; Fojta, Miroslav; Jelen, František; Vetterl, Vladimír

    Weinheim : WileyVCH, 2002 - (Bard, A.; Stratmann, M.; Wilson, G.), s. 365-429 ISBN 3-527-30401-0 R&D Projects: GA ČR GV204/97/K084; GA AV ČR IBS5004107; GA AV ČR IAA4004901; GA AV ČR IAA4004002 Institutional research plan: CEZ:AV0Z5004920 Keywords : nucleic acid s * electrochemical analysis * DNA biosensors Subject RIV: BO - Biophysics

  9. Diabetes and alpha lipoic acid

    IssyLaher

    2011-01-01

    Diabetes mellitus is a multi-faceted metabolic disorder where there is increased oxidative stress that contributes to the pathogenesis of this debilitating disease. This has prompted several investigations into the use of antioxidants as a complementary therapeutic approach. Alpha lipoic acid, a naturally occurring dithiol compound which plays an essential role in mitochondrial bioenergetic reactions, has gained considerable attention as an antioxidant for use in managing diabetic complicatio...

  10. Diabetes and Alpha Lipoic Acid

    Golbidi, Saeid; Badran, Mohammad; Laher, Ismail

    2011-01-01

    Diabetes mellitus is a multi-faceted metabolic disorder where there is increased oxidative stress that contributes to the pathogenesis of this debilitating disease. This has prompted several investigations into the use of antioxidants as a complementary therapeutic approach. Alpha lipoic acid, a naturally occurring dithiol compound which plays an essential role in mitochondrial bioenergetic reactions, has gained considerable attention as an antioxidant for use in managing diabetic complicatio...

  11. Acid Rain: The Silent Environmental Threat.

    Zmud, Mia

    1992-01-01

    Describes the silent environmental threat posed by acid rain. Caused mainly by manmade pollutants, acid rain damages water and trees, decreases visibility, corrodes monuments, and threatens public health. The article includes guidelines for action. (SM)

  12. Nature in the Classroom: Acid Rain.

    Doyle, Charles

    1982-01-01

    As a lesson topic, acid rain is defined, its chemistry given, and its development since the 1950s described. The worldwide effects of acid rain are discussed along with the available technology for controlling the problem. (CM)

  13. How Acid Reflux Disease Damages Teeth

    ... more Seniors' Oral Health How to Keep Your Teeth for a Lifetime Tooth loss is simply the ... your desktop! more... How Acid Reflux Disease Damages Teeth Article Chapters How Acid Reflux Disease Damages Teeth ...

  14. Recovery of mercury from acid waste residues

    Greenhalgh, Wilbur O.

    1989-01-01

    Mercury can be recovered from nitric acid-containing fluids by reacting the fluid with aluminum metal to produce mercury metal, and then quenching the reactivity of the nitric acid prior to nitration of the mercury metal.

  15. Histidine-Containing Peptide Nucleic Acids

    2000-01-01

    Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics.......Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics....

  16. RETINOIC ACID ALTERS EPITHELIAL DIFFERENTIATION DURING PALATOGENESIS

    Retinoids are teratogenic in humans and animals, producing a syndrome of craniofacial malformations which includes cleft palate. his study investigates the mechanism through which retinoic acid induces cleft palate. urine palatogenesis after exposure to retinoic acid in utero is ...

  17. Role of succinic acid in chemical evolution

    Negron-Mendoza, A.; Ponnamperuma, C.

    1982-01-01

    Succinic acid is converted into other carboxylic acids by ionizing radiation. The results obtained have been correlated with the ready formation of this compound in prebiotic experiments. Its role in biological systems may be related to its prebiotic occurrence.

  18. Acid rain information book. Second edition

    Potential consequences of widespread acid precipitation are reviewed through an extensive literature search. Major aspects of the acid rain phenomena are discussed, areas of uncertainty identified, and current research summarized

  19. Stereochemistry of a Rhododaurichromanic Acid Derivative.

    Swamy, Mahadeva M M; Mándi, Attila; Anetai, Masaki; Monde, Kenji

    2016-02-01

    A rhododaurichromanic acid A derivative was synthesized from the naturally occurring daurichromenic acid in enantiomeric pure form. Its absolute configuration was elucidated by applying VCD, ECD and DFT calculations. PMID:27032199

  20. Thermal Stability Of Formohydroxamic Acid

    Fondeur, F. F.; Rudisill, T. S.

    2011-10-21

    The thermal stability of formohydroxamic acid (FHA) was evaluated to address the potential for exothermic decomposition during storage and its use in the uranium extraction process. Accelerating rate calorimetry showed rapid decomposition at a temperature above 65 {degree}C; although, the rate of pressure rise was greater than two orders of magnitude less than the lower bound for materials which have no explosive properties with respect to transportation. FHA solutions in water and nitric acid did not reach runaway conditions until 150 {degree}C. Analysis by differential scanning calorimetry showed that FHA melted at 67 {degree}C and thermally decomposed at 90 {degree}C with an enthalpy of -1924 J/g. The energics of the FHA thermal decomposition are comparable to those measured for aqueous solutions of hydroxylamine nitrate. Solid FHA should be stored in a location where the temperature does not exceed 20-25 {degree}C. As a best practice, the solid material should be stored in a climate-controlled environment such as a refrigerator or freezer. FHA solutions in water are not susceptible to degradation by acid hydrolysis and are the preferred way to handle FHA prior to use.

  1. Oleic acid biosynthesis in cyanobacteria

    The biosynthesis of fatty acids in cyanobacteria is very similar to the well characterized system found in green plants. However, the initial desaturation of stearic acid in cyanobacteria appears to represent a significant departure from plant systems in which stearoyl-ACP is the exclusive substrate for desaturation. In Anabaena variabilis, the substrate appears to be monoglucosyldiacylglycerol, a lipid not found in plants. The authors examined five different cyanobacteria to determine if the pathway in A. variabilis was generally present in other cyanobacteria. The cyanobacteria studied were A. variabilis, Chlorogloeopsis sp., Schizothrix calcicola, Anacystis marina, and Anacystis nidulans. Each were grown in liquid culture, harvested, and examined for stearoyl-ACP desaturase activity or incubated with 14CO2. None of the cyanobacteria contained any stearoyl-ACP desaturase activity in whole homogenates or 105,000g supernatants. All were capable of incorporating 14CO2 into monoglucosyldiacylglycerol and results from incubations of 20 min, 1 hr, 1 hr + 10 hr chase were consistent with monoglucosyldiacylglycerol serving as precursor for monogalctosyldiacylglycerol. Thus, initial evidence is consistent with oleic acid biosynthesis occurring by desaturation of stearoyl-monoglucosyldiacylglycerol in all cyanobacteria

  2. Incorporation of conjugated linoleic acid (CLA and α-linolenic acid (LNA in pacu fillets

    Deoclécio José Barilli

    2014-03-01

    Full Text Available The objective of this study was to evaluate the incorporation of conjugated linoleic acid and α-linolenic acid in fillets of pacu fish raised in net cages and fed diets enriched with these acids. The fish were fed for 49 days, and at the end of this period the fatty acid content in the fillets was determined by gas chromatography. Concentrations of α-linolenic acid, eicosapentaenoic acid, and the total omega-3 (n-3 fatty acid in the fillets increased, improving the n-6/n-3 ratio. In addition, the incorporation of conjugated linoleic acid in the fish fillets proved well established. This study showed that the use of diets enriched with conjugated linoleic acid and α-linolenic acid results in the incorporation of these acids in the of pacu fish fillets, improving their nutritional quality.

  3. Capture and release of acid-gasses with acid-gas binding organic compounds

    Heldebrant, David J; Yonker, Clement R; Koech, Phillip K

    2015-03-17

    A system and method for acid-gas capture wherein organic acid-gas capture materials form hetero-atom analogs of alkyl-carbonate when contacted with an acid gas. These organic-acid gas capture materials include combinations of a weak acid and a base, or zwitterionic liquids. This invention allows for reversible acid-gas binding to these organic binding materials thus allowing for the capture and release of one or more acid gases. These acid-gas binding organic compounds can be regenerated to release the captured acid gasses and enable these organic acid-gas binding materials to be reused. This enables transport of the liquid capture compounds and the release of the acid gases from the organic liquid with significant energy savings compared to current aqueous systems.

  4. Analysis of the apple fruit acid/low-acid trait by SSR markers

    Yuxin YAO; Heng ZHAI; Lingling ZHAO; Kai YI; Zhi LIU; Ye SONG

    2008-01-01

    It is necessary to find out the genetic character-istics of malic acid in the course of apple genomic research and breeding. In this study, the SSR marker linked to the acid/low-acid trait in apple fruit was identified from 140 SSR primer pairs, using 91 F1 population hybrids from the intra-specific cross between apple cultivar 'Dongguang' and 'Fuji' as the experimental materials. Of 140 SSR primer pairs, only primer SDY085 produced a polymorphic band linked to acid trait, and the linkage distance was 8.89 cM. Also, the titrated acid and malic acid in different developmental stages were determined. The SSR marker analysis, coupled with the change of the total acid and malic acid contents, revealed that the acid/low-acid trait was governed by a major gene and acid trait was completely dominant.

  5. Transformation of chenodeoxycholic acid to ursodeoxycholic acid in patients with Crohn's disease

    In vivo 7 beta-epimerization of chenodeoxycholic acid to ursodeoxycholic acid and the role of 7-ketolithocholic acid as an intermediate in this biotransformation were studied in 11 patients with Crohn's disease and in 5 healthy volunteers. The incorporation of deuterium into biliary ursodeoxycholic acid and 7-ketolithocholic acid was determined by computed gas chromatography-mass fragmentography after ingestion of a dideuterated chenodeoxycholic acid, chenodeoxycholic-11,12-d2 acid. The incorporation of deuterium into ursodeoxycholic acid increased to a peak level at 48 h in the patients with Crohn's disease, but was delayed in healthy volunteers. In 8 patients and 2 healthy controls there were small amounts of 7-ketolithocholic acid in bile. The incorporation of deuterium into 7-ketolithocholic acid was confirmed in only 2 patients and the peak level was noted at 48 h. These observations suggest that 7-ketolithocholic acid is an intermediate of this biotransformation in patients with Crohn's disease

  6. Profile of Fatty Acids, Amino Acids, Carotenoid Total, and α-Tocopherol from Flying Fish Eggs

    Aulia Azka

    2015-12-01

    Full Text Available Flying fish are found in waters of eastern Indonesia, which until now is still limited information about nutritional content. The purpose of this research was determine the composition of fatty acids, amino acids, total carotenoids, α-tocopherol flying fish eggs (Hyrundicthys sp.. The composition of fatty acid was measured by gas chromatography (GC, while amino acids, total carotenoids, α-tocopherol was measured by High performanced Liquid Chromatography (HPLC. Egg contained 22 fatty acids such as saturated fatty acid 29.71%, monounsaturated fatty acid 7.86%, and polysaturated fatty acid 13.64%. The result showed that eggs flying fish contained 17 amino acids, such as essential amino acid 14.96% and non-essential amino acids 20.27%. Eggs contained a total carotenoid of 245.37 ppm. α-tocopherol content of flying fish eggs by 1.06 ppm.

  7. Study of americium sorption by humic acids

    The results of investigation of influence of the cation content and acidity of soil solution on americium sorption by the humic acids have been shown. The most influence on the interphase distribution coefficient in the system 'humic acid - model soil solution' is caused by the presence of the iron (III), calcium ions and acidity of the solution. The increase of the sodium ions concentration in the solution makes an insignificant impact on the americium sorption. (Authors)

  8. Recovery of boric acid from ion exchangers

    The recovery of boric acid from an anion exchange resin is improved by eluting the boric acid with an aqueous solution of ammonium bicarbonate. The boric acid can be readily purified and concentrated by distilling off the water and ammonium bicarbonate. This process is especially useful for the recovery of boric acid containing a high percentage of 10B which may be found in some nuclear reactor coolant solutions. 10 claims

  9. CLIMATE CHANGE ADAPTATION IN ACID SULFATE LANDSCAPES

    Chuxia Lin

    2012-01-01

    Oxidation of sulfide minerals produces sulfuric acid and consequently creates Acid Sulfate Landscapes (ASLs), which represent one of the most degraded types of land-surface environments. Although acid sulfate-producing weathering is a naturally occurring process, it is markedly facilitated by human intervention. Mining is by far the dominant anthropogenic cause for the creation of inland acid sulfate footprints while land reclamation in coastal lowlands is the driver for the formation of coas...

  10. Direct Channeling of Retinoic Acid between Cellular Retinoic Acid-Binding Protein II and Retinoic Acid Receptor Sensitizes Mammary Carcinoma Cells to Retinoic Acid-Induced Growth Arrest

    Budhu, Anuradha S.; Noy, Noa

    2002-01-01

    Cellular retinoic acid-binding protein II (CRABP-II) is an intracellular lipid-binding protein that associates with retinoic acid with a subnanomolar affinity. We previously showed that CRABP-II enhances the transcriptional activity of the nuclear receptor with which it shares a common ligand, namely, the retinoic acid receptor (RAR), and we suggested that it may act by delivering retinoic acid to this receptor. Here, the mechanisms underlying the effects of CRABP-II on the transcriptional ac...

  11. Folic acid derivatives for use in radioimmunoassay

    The chemical preparation of two folic acid derivatives, labelled with 125I or 131I, is described for use in radioimmunoassay of folic acid and its metabolites in biological fluids such as blood serum. Labelled compounds of the present invention more closely resemble folic acid in that they have glutamic acid in the terminal position. Examples of the use of these compounds in three different assays are given. (U.K.)

  12. Microbial production of natural poly amino acid

    SHI Feng; XU ZhiNan; CEN PeiLin

    2007-01-01

    Three kinds of poly amino acids, poly-γ-glutamic acid, poly(ε-L-lysine) and multi-L-arginyl-poly (L-aspartic acid) can be synthesized by enzymatic process independently from ribosomal protein biosynthesis pathways in microorganism. These biosynthesized polymers have attracted more and more attentions because of their unique properties and various applications. In this review, the current knowledge on the biosynthesis, biodegradations and applications of these three poly amino acids are summarized.

  13. Enhancement of colposcopic image by sulphosalicylic acid.

    Khilnani P

    1993-01-01

    Full Text Available Acetic acid is used conventionally for enhancement of the colposcopic image. We used sulphosalicylic acid instead of acetic acid in 50 normal cases. The normal appearance was enhanced in all cases. The image was also enhanced in 70% cases of cervical intraepithelial neoplasia and 90% cases of cervical condyloma accuminata. The image was not inferior to that with acetic acid in any of the cases.

  14. Complicated Composting: Persistent Pyridine Carboxylic Acid Herbicides

    Reimer, Julie

    2013-01-01

    This paper reviews pyridine carboxylic acid herbicide impacts on compost. Pyridine carboxylic acid herbicides are not completely broken down during grass growth, harvest and drying of hay, in the digestive tract of livestock, or during composting. These herbicides are a popular choice for broadleaf weed control because of this persistence: they remain effective for months or years. Pyridine carboxylic acids are also more effective than the common herbicide 2, 4-dichlorophenoxyacetic acid and ...

  15. 21 CFR 172.320 - Amino acids.

    2010-04-01

    ...-Cysteine L-Cystine L-Glutamic acid L-Glutamine Aminoacetic acid (glycine) L-Histidine L-Isoleucine L... following: L-Asparagine L-Aspartic acid L-Glutamine L-Histidine (c) The additive(s) is used or intended for....4 Aminoacetic acid (glycine) 3.5 L-Histidine 2.4 L-Isoleucine 6.6 L-Leucine 8.8 L-Lysine 6.4 L-...

  16. Removal of lactobionic acid by electrodialysis

    J. B. Severo Júnior; ALVES T. L. M.; H. C. Ferraz

    2014-01-01

    Lactobionic acid has a number of applications, such as in cosmetic formulations and detergents, as well as in the medical field, where it is used for the preservation of organs destined for transplantation. Previous studies have reported that a promising alternative procedure for the production of lactobionic acid is the biotechnological route, using permeabilized cells of Zymomonas mobilis to produce sorbitol and lactobionic acid from fructose and lactose. However, the acid produced during t...

  17. Drug Nanoparticle Formulation Using Ascorbic Acid Derivatives

    Kunikazu Moribe; Waree Limwikrant; Kenjirou Higashi; Keiji Yamamoto

    2011-01-01

    Drug nanoparticle formulation using ascorbic acid derivatives and its therapeutic uses have recently been introduced. Hydrophilic ascorbic acid derivatives such as ascorbyl glycoside have been used not only as antioxidants but also as food and pharmaceutical excipients. In addition to drug solubilization, drug nanoparticle formation was observed using ascorbyl glycoside. Hydrophobic ascorbic acid derivatives such as ascorbyl mono- and di-n-alkyl fatty acid derivatives are used either as drugs...

  18. Fatty Acid Composition of Agaricus bisporus (Lange) Sing.

    Aktümsek, Abdurrahman; ÖZTÜRK, Celâleddin; KAŞIK, Giyasettin

    1998-01-01

    Fatty acid compositions of fruit body, stem, lamellae and total of Agaricus bisporus were seperately analysed by GLC. In the all fatty acid compositions of A. bisporus, linoleic acid were predominant. Percentages of linoleic acid were varied between 53.45 - 68.78%. It was showed that the other major fatty acids were palmitic, oleic and stearic acid in the fatty acid compositions.

  19. Acid Rain: What We Must Do.

    Gorham, Eville

    1983-01-01

    Addresses questions about the nature, source, and history of acid rain. In addition, discusses the questions: Why is acid rain a problem? Is acid rain getting worse? What is the threat of further problems? Concludes that it is time to act on the problem and recommends an appropriate course of action. (JN)

  20. Acid Rain. LC Science Tracer Bullet.

    Hollmann, Pauline, Comp.

    The term "acid rain," also called "acid precipitation," generally refers to any precipitation having a pH value of less than 5.6. This guide to the literature on acid rain in the collections of the Library of Congress is not necessarily intended to be a comprehensive bibliography. It is designed to provide the reader with a set of resources that…

  1. Acid Rain Students Do Original Research.

    Outdoor Communicator, 1984

    1984-01-01

    At Park Senior High School (Cottage Grove, Minnesota), 46 juniors and seniors planted 384 red pine seedlings in connection with their original research on acid rain, with advice from Dr. Harriet Stubbs, director of the Acid Precipitation Awareness Program (West Saint Paul), which has been developing acid rain teaching materials. (MH)

  2. Genetics of proteinases of lactic acid bacteria

    Kok, Jan; Venema, Gerhardus

    1988-01-01

    Because it is essential for good growth with concomitant rapid acid production, and for the production of flavorous peptides and amino acids, the proteolytic ability of lactic acid bacteria is of crucial importance for reliable dairy product quality. In view of this importance, considerable research

  3. Allelochemical phenolic acids from Gypsophila paniculata

    Bioassay-guided fractionation of Gypsophila paniculata L. (Caryophyllaceae) resulted in the isolation of the phenolics p-coumaric acid (1), dihydroferulic acid (2), and syringic acid (3). In addition to their noted weak antimicrobial activity, compounds 1 and 3 are known to be potent exuded alleloc...

  4. Acrylic Acid and Esters Will Be Oversupply

    Zheng Chengwang

    2007-01-01

    @@ Drastic capacity growth The production capacity of acrylic acid in China has grown drastically in recent years. With the completion of the 80 thousand t/a acrylic acid and 130 thous and t/a acrylic ester project in Shenyang Paraffin Chemical Industrial Co., Ltd., (CCR2006,No. 31) the capacity of acrylic acid in China has reached 882 thousand t/a.

  5. Dietary arachidonic acid in perinatal nutrition

    Lauritzen, Lotte; Fewtrell, Mary; Agostoni, Carlo

    2015-01-01

    Arachidonic acid (AA) is supplied together with docosahexaenoic acid (DHA) in infant formulas, but we have limited knowledge about the effects of supplementation with either of these long-chain polyunsaturated fatty acids (LCPUFA) on growth and developmental outcomes. AA is present in similar lev...

  6. Lipoxygenase inhibitory activity of anacardic acids.

    Ha, Tae Joung; Kubo, Isao

    2005-06-01

    6[8'(Z)-pentadecenyl]salicylic acid, otherwise known as anacardic acid (C15:1), inhibited the linoleic acid peroxidation catalyzed by soybean lipoxygenase-1 (EC 1.13.11.12, type 1) with an IC50 of 6.8 microM. The inhibition of the enzyme by anacardic acid (C15:1) is a slow and reversible reaction without residual activity. The inhibition kinetics analyzed by Dixon plots indicates that anacardic acid (C15:1) is a competitive inhibitor and the inhibition constant, KI, was obtained as 2.8 microM. Although anacardic acid (C15:1) inhibited the linoleic acid peroxidation without being oxidized, 6[8'(Z),11'(Z)-pentadecadienyl]salicylic acid, otherwise known as anacardic acid (C15:2), was dioxygenated at low concentrations as a substrate. In addition, anacardic acid (C15:2) was also found to exhibit time-dependent inhibition of lipoxygenase-1. The alk(en)yl side chain of anacardic acids is essential to elicit the inhibitory activity. However, the hydrophobic interaction alone is not enough because cardanol (C15:1), which possesses the same side chain as anacardic acid (C15:1), acted neither as a substrate nor as an inhibitor. PMID:15913294

  7. 21 CFR 582.1095 - Sulfuric acid.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is...

  8. Tranexamic acid for upper gastrointestinal bleeding

    Gluud, Lise Lotte; Klingenberg, Sarah Louise; Langholz, Ebbe

    2012-01-01

    Tranexamic acid reduces haemorrhage through its antifibrinolytic effects. In a previous version of the present review, we found that tranexamic acid may reduce mortality. The present review includes updated searches of randomised trials on tranexamic acid versus placebo, cimetidine or lansoprazole....

  9. Unnatural reactive amino acid genetic code additions

    Deiters, Alexander; Cropp, Ashton T; Chin, Jason W; Anderson, Christopher J; Schultz, Peter G

    2013-05-21

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  10. Unnatural reactive amino acid genetic code additions

    Deiters, Alexander; Cropp, T. Ashton; Chin, Jason W.; Anderson, J. Christopher; Schultz, Peter G.

    2014-08-26

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  11. Acid rain and the NAPAP study

    This article reports on preliminary state of science and technology reports on acidic deposition released by the National Acid Precipitation Assessment Program. These are part of the integrated assessment of acidic deposition and related air pollutants to be released at a later date. SO2 and NOx emissions and effects are discussed

  12. More on Effects Controlling Carboxylic Acidity.

    Schwartz, Lowell M.

    1981-01-01

    Gas phase acidity data shown are offered to writers of elementary organic chemistry texts for replacement of the aqueous phase data that are universally used. Relative acidities in the gas phase are controlled virtually exclusively by enthalpic factors. Structural-energetic explanations of acidic trends can therefore be used. (SK)

  13. 21 CFR 582.1061 - Lactic acid.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lactic acid. 582.1061 Section 582.1061 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1061 Lactic acid. (a) Product. Lactic acid. (b) Conditions of use. This substance is...

  14. Solid-state actinide acid phosphites from phosphorous acid melts

    Oh, George N. [Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Burns, Peter C., E-mail: pburns@nd.edu [Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2014-07-01

    The reaction of UO{sub 3} and H{sub 3}PO{sub 3} at 100 °C and subsequent reaction with dimethylformamide (DMF) produces crystals of the compound (NH{sub 2}(CH{sub 3}){sub 2})[UO{sub 2}(HPO{sub 2}OH)(HPO{sub 3})]. This compound crystallizes in space group P2{sub 1}/n and consists of layers of uranyl pentagonal bipyramids that share equatorial vertices with phosphite units, separated by dimethylammonium. In contrast, the reaction of phosphorous acid and actinide oxides at 210 °C produces a viscous syrup. Subsequent dilution in solvents and use of standard solution-state methods results in the crystallization of two polymorphs of the actinide acid phosphites An(HPO{sub 2}OH){sub 4} (An=U, Th) and of the mixed acid phosphite–phosphite U(HPO{sub 3})(HPO{sub 2}OH){sub 2}(H{sub 2}O)·2(H{sub 2}O). α- and β-An(HPO{sub 2}OH){sub 4} crystallize in space groups C2/c and P2{sub 1}/n, respectively, and comprise a three-dimensional network of An{sup 4+} cations in square antiprismatic coordination corner-sharing with protonated phosphite units, whereas U(HPO{sub 3})(HPO{sub 2}OH){sub 2}(H{sub 2}O){sub 2}·(H{sub 2}O) crystallizes in a layered structure in space group Pbca that is composed of An{sup 4+} cations in square antiprismatic coordination corner-sharing with protonated phosphites and water ligands. We discuss our findings in using solid inorganic reagents to produce a solution-workable precursor from which solid-state compounds can be crystallized. - Graphical abstract: Reaction of UO{sub 3} and H{sub 3}PO{sub 3} at 100 °C and subsequent reaction with DMF produces crystals of (NH{sub 2}(CH{sub 3}){sub 2})[UO{sub 2}(HPO{sub 2}OH)(HPO{sub 3})] with a layered structure. Reaction of phosphorous acid and actinide oxides at 210 °C produces a viscous syrup and further solution-state reactions result in the crystallization of the actinide acid phosphites An(HPO{sub 2}OH){sub 4} (An=U, Th), with a three-dimensional network structure, and the mixed acid phosphite

  15. Structure of seven organic salts assembled from 2,6-diaminopyridine with monocarboxylic acids, dicarboxylic acids, and tetracarboxylic acids

    Gao, Xingjun; Zhang, Huan; Wen, Xianhong; Liu, Bin; Jin, Shouwen; Wang, Daqi

    2015-08-01

    Studies concentrating on non-covalent interactions between the organic base of 2,6-diaminopyridine, and carboxylic acids have led to an increased understanding of the role 2,6-diaminopyridine in binding with carboxylic acid derivatives. Here anhydrous and hydrated multi-component organic acid-base salts of 2,6-diaminopyridine have been prepared with the carboxylic acids as nicotinic acid, o-chlorobenzoic acid, 1,3-benzodioxole-5-carboxylic acid, 3,5-dinitrosalicylic acid, 4-nitro-phthalic acid, 1,4-cyclohexanedicarboxylic acid, and butane-1,2,3,4-tetracarboxylic acid. The seven crystalline compounds were characterized by X-ray diffraction analysis, infrared (IR), melting point (mp), and elemental analysis. All structures adopted the hetero R22(8) supramolecular synthons. The supramolecular architectures bear extensive Nsbnd H⋯N, Osbnd H⋯N, Osbnd H⋯O, Nsbnd H⋯O, and CH⋯O associations as well as other nonbonding contacts as CHsbnd N, CH2sbnd O, π-π, C-π, O-π, Cl-π, Clsbnd O, and Osbnd O interactions. The role of weak and strong hydrogen bonding in the crystal packing is ascertained.

  16. SEM ANALYSIS OF THE ACID-ETCHED ENAMEL PATTERNS PROMOTED BY ACIDIC MONOMERS AND PHOSPHORIC ACIDS

    Mirela Sanae Shinohara; Marcelo Tavares de Oliveira; Vinícius Di Hipólito; Marcelo Giannini; Mario Fernando de Goes

    2006-01-01

    ABSTRACT OBJECTIVE: Although self-etching bonding systems (SES) are indicated to prepare dental enamel for bonding, concerns have been expressed regarding their effectiveness. The aim of this study was to analyze the etching pattern (EP) of nine SES in comparison with 35% and 34% phosphoric acid etchants (FA) on intact (IN) and ground (GR) enamel surface. MATERIALS AND METHODS: Twenty-two human third molars were sectioned in mesial-distal and buccal-lingual directions, and four dental fragmen...

  17. Radiolysis of Sulfuric Acid, Sulfuric Acid Monohydrate, and Sulfuric Acid Tetrahydrate and Its Relevance to Europa

    Loeffler, M. J.; Hudson, R. L.; Moore, M. H.; Carlson, R. W.

    2011-01-01

    We report laboratory studies on the 0.8 MeV proton irradiation of ices composed of sulfuric acid (H2SO4), sulfuric acid monohydrate (H2SO4 H2O), and sulfuric acid tetrahydrate (H2SO4 4H2O) between 10 and 180 K. Using infrared spectroscopy, we identify the main radiation products as H2O, SO2, (S2O3)x, H3O+, HSO4(exp -), and SO4(exp 2-). At high radiation doses, we find that H2SO4 molecules are destroyed completely and that H2SO4 H2O is formed on subsequent warming. This hydrate is significantly more stable to radiolytic destruction than pure H2SO4, falling to an equilibrium relative abundance of 50% of its original value on prolonged irradiation. Unlike either pure H2SO4 or H2SO4 H2O, the loss of H2SO4 4H2O exhibits a strong temperature dependence, as the tetrahydrate is essentially unchanged at the highest irradiation temperatures and completely destroyed at the lowest ones, which we speculate is due to a combination of radiolytic destruction and amorphization. Furthermore, at the lower temperatures it is clear that irradiation causes the tetrahydrate spectrum to transition to one that closely resembles the monohydrate spectrum. Extrapolating our results to Europa s surface, we speculate that the variations in SO2 concentrations observed in the chaotic terrains are a result of radiation processing of lower hydration states of sulfuric acid and that the monohydrate will remain stable on the surface over geological times, while the tetrahydrate will remain stable in the warmer regions but be destroyed in the colder regions, unless it can be reformed by other processes, such as thermal reactions induced by diurnal cycling.

  18. Simultaneous detection of ascorbic acid, uric acid and homovanillic acid at copper modified electrode

    Selvaraju, T. [Centre for Photoelectrochemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625021 (India); Ramaraj, R. [Centre for Photoelectrochemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625021 (India)]. E-mail: ramarajr@yahoo.com

    2007-02-15

    The copper was deposited on glassy carbon (GC) and indium tin oxide (ITO) electrodes by electrochemical method. The copper structures on electrode were characterized by atomic force microscope, X-ray diffractometeric pattern and differential pulse voltammetric studies. Optimal conditions for uniform growth of copper structures on the electrode were established. Voltammetric sensor was fabricated using the copper deposited GC electrode for the simultaneous detection and determination of uric acid (UA) and homovanillic acid (HVA) in the presence of excess concentrations of ascorbic acid (AA). The voltammetric signals due to AA and UA oxidation were well separated with a potential difference of 400 mV and AA did not interfere with the measurement of UA and HVA at the GC/Cu electrode. Linear calibration curves were obtained in the concentration range 1-40 {mu}M for AA and 20-50 {mu}M for UA at physiological pH and a detection limit of 10 nM of UA in the presence of 10-fold excess concentrations of AA was achieved. The simultaneous detection of submicromolar concentrations of AA, UA and HVA was achieved at the GC/Cu electrode. The practical utility of the present GC/Cu modified electrode was demonstrated by measuring the AA content in Vitamin C tablet, UA content in human urine and blood serum samples with satisfactory results.

  19. Desaturation of fatty acids in Trypanosoma cruzi

    Uptake and metabolism of saturated (16:0, 18:0) and unsaturated [18:1(n-9), 18:2(n-6), 18:3(n-3)] fatty acids by cultured epimastigotes of Trypanosoma cruzi were studied. Between 17.5 and 33.5% of the total radioactivity of [1-14C]labeled fatty acids initially added to the culture medium was incorporated into the lipids of T. cruzi and mostly choline and ethanolamine phospholipids. As demonstrated by argentation thin layer chromatography, gas liquid chromatography and ozonolysis of the fatty acids synthesized, exogenous palmitic acid was elongated to stearic acid, and the latter was desaturated to oleic acid and 18:2 fatty acid. The 18:2 fatty acid was tentatively identified as linoleic acid with the first bond in the delta 9 position and the second bond toward the terminal methyl end. Exogenous stearic acid was also desaturated to oleic and 18:2 fatty acid, while oleic acid was only converted into 18:2. All of the saturated and unsaturated fatty acids investigated were also converted to a small extent (2-4%) into polyunsaturated fatty acids. No radioactive aldehyde methyl ester fragments of less than nine carbon atoms were detected after ozonolysis of any of the fatty acids studied. These results demonstrate the existence of delta 9 and either delta 12 or delta 15 desaturases, or both, in T. cruzi and suggest that delta 6 desaturase or other desaturases of the animal type are likely absent in cultured forms of this organism

  20. Uptake of actinides by sulphonated phosphinic acid resin from acid medium

    The removal of uranium and americium from nitric acid solutions by sulphonated phosphinic acid resin has been investigated. The capacity of the sulphonated resin exceeds the capacities of phosphinic acid resin and commercial cation exchange resin. Other advantages of the sulphonated resin for uranium and americium removal include reduced sensitivity to acidity and inert salt concentration. (author)

  1. The corrosion protection of several aluminum alloys by chromic acid and sulfuric acid anodizing

    Danford, M. D.

    1994-01-01

    The corrosion protection afforded 7075-T6, 7075-T3, 6061-T6, and 2024-T3 aluminum alloys by chromic acid and sulfuric acid anodizing was examined using electrochemical techniques. From these studies, it is concluded that sulfuric acid anodizing provides superior corrosion protection compared to chromic acid anodizing.

  2. Molecular pharmacology of 4-substituted glutamic acid analogues at ionotropic and metabotropic excitatory amino acid receptors

    Bräuner-Osborne, Hans; Nielsen, B; Stensbøl, T B; Johansen, T N; Skjaerbaek, N; Krogsgaard-Larsen, P

    The pharmacology of (2S,4R)-4-methylglutamic acid, (2S,4S)-4-methylglutamic acid and (S)- and (R)-4-methyleneglutamic acids (obtained in high chemical and enantiomeric purity from racemic 4-methyleneglutamic acid by chiral HPLC using a Crownpak CR(+) column), was examined in binding experiments u...

  3. Device for the detection of acid vapors and particularly hydrofluoric acid vapors

    This device concerns the detection of acid vapors contained in a gaseous environment which have to be controlled. It uses a detector with a calorimetric material. It can be used to detect acid vapors, but it detects particularly hydrofluoric acid vapors. In nuclear industry, this device can detect hydrofluoric acid from UF6, even at high temperature. (TEC)

  4. Kinetic study on the acid-catalyzed hydrolysis of cellulose to levulinic acid

    Girisuta, B.; Janssen, L. P. B. M.; Heeres, H. J.

    2007-01-01

    A variety of interesting bulk chemicals is accessible by the acid-catalyzed hydrolysis of cellulose. An interesting example is levulinic acid, a versatile precursor for fuel additives, polymers, and resins. A detailed kinetic study on the acid-catalyzed hydrolysis of cellulose to levulinic acid is r

  5. Interference effects from coexisting fatty acids on elaidic acid separation by fractionating crystallization: A model study

    Jala, Ram Chandra Reddy; Guo, Zheng; Bjerring, Thomas;

    2010-01-01

    A multi-stage temperature-programmed fractionating crystallization process was carried out to examine the effects of the presence of stearic acid (SA), oleic acid (OA), and linoleic acid (LA) on the separation of elaidic acid (EA). The results showed that the efficiency of fractionating...

  6. Separation and identification of amino acids from lignite humic acids by thin layer chromatography

    Damian, L.; Marutoiu, C.; Niac, G.

    1985-07-01

    Thin layer chromatography with and without temperature gradient was used to identify ten amino acids in the humic acid hydrolysate of Rovinari lignite, using cellulose and volcanic tuff as stationary phases. The acids found were L-leucine, isoleucine, phenylalanine, L-valine, tyrosine, proline, L-alanine, glutamic acid, threonine and L-lysine. 8 references.

  7. The Effects of EPA, DHA, and Aspirin Ingestion on Plasma Lysophospholipids and Autotaxin

    Block, RC; Duff, R; Lawrence, P.; Kakinami, L.; Brenna, JT; Shearer, GC; Meednu, N; Mousa, S; Friedman, A.; Harris, WS; Larson, Mark; Georas, S

    2010-01-01

    Lysophophatidylcholine (LPC) and lysophosphatidic acid (LPA) are potent lysolipid mediators increasingly linked with atherosclerosis and inflammation. A current model proposing that plasma LPA is produced when LPC is hydrolyzed by the enzyme autotaxin has not been rigorously investigated in human subjects. We conducted a clinical trial of eicosapentaenoic acid/docosahexaenoic acid (EPA/DHA) and aspirin ingestion in normal volunteers. Fasting blood samples were drawn at baseline and after 4-we...

  8. Determination of bile acids by radioimmunoassays

    The present paper, based on the current literature, considers the practical aspects of bile acid radioimmunoassays. The problems assoziated with the raising of specific antisera and their characterization are discussed. Features of assay design for bile acids are considered. Solid-phase radioimmunoassays are described for separate determination of unconjugated cholic acid and conjugated cholic acid in serum. The clinical application of specific bile acid radioimmunoassays is shown by an 'oral cholate tolerance test' as a sensitive indicator of liver function and by an 'oral cholylglycine tolerance test' for characterization of intenstinal function in diarrheal states. (orig.)

  9. Formation constants of mixed ligand complexes of oxovanadium(IV) with salicylic acid/5-sulphosalicylic acid/8-hydroxyquinoline-5-sulphonic acid and hippuric acid

    Equilibrium studies are described on the interaction of oxovanadium(IV) with salicylic acid (SA)/5-sulphosalicylic acid (SSA)/8-hydroxyquinoline-5-sulphonic acid (HQSA) in presence of hippuric acid. The formation of 1:1:1 mixed ligand complexes and their hydroxo derivatives inferred from the pH-metric titration curves and formation constants of 1:1:1 ternary complexes have been evaluated at 30 +- 0.5deg (μ = 0.1 M KNO3). The order of stability of ternary complexes has been found to be the same as that of 1:1 binary complexes involving hydroxy acids. (author)

  10. Bile acids in regulation of intestinal physiology.

    Keating, Niamh

    2009-10-01

    In addition to their roles in facilitating lipid digestion and absorption, bile acids are recognized as important regulators of intestinal function. Exposure to bile acids can dramatically influence intestinal transport and barrier properties; in recent years, they have also become appreciated as important factors in regulating cell growth and survival. Indeed, few cells reside within the intestinal mucosa that are not altered to some degree by exposure to bile acids. The past decade saw great advances in the knowledge of how bile acids exert their actions at the cellular and molecular levels. In this review, we summarize the current understanding of the role of bile acids in regulation of intestinal physiology.

  11. Solvent extraction of metals with hydroxamic acids.

    Vernon, F; Khorassani, J H

    1978-07-01

    Solvent extraction with hydroxamic acids has been investigated. with comparison of aliphatic and aromatic reagents for the extraction of iron, copper, cobalt and nickel. Caprylohydroxamic acid has been evaluated for use in extraction systems for titanium, vanadium, chromium, molybdenum and uranium, both in terms of acidity of aqueous phase and oxidation state of the metal. It has been established that caprylohydroxamic acid in 1-hexanol is a suitable extractant for the removal of titanium(IV), vanadium(V), chromium(VI), molybdenum(VI) and uranium(VI) from 6M hydrochloric acid. PMID:18962288

  12. Chicoric acid: chemistry, distribution, and production

    Jungmin eLee

    2013-12-01

    Full Text Available Though chicoric acid was first identified in 1958, it was largely ignored until recent popular media coverage cited potential health beneficial properties from consuming food and dietary supplements containing this compound. To date, plants from at least 63 genera and species have been found to contain chicoric acid, and while the compound is used as a processing quality indicator, it may also have useful health benefits. This review of chicoric acid summarizes research findings and highlights gaps in research knowledge for investigators, industry stakeholders, and consumers alike. Additionally, chicoric acid identification and quantification methods, biosynthesis, processing improvements to increase chicoric acid retention, and potential areas for future research are discussed.

  13. DOES JASMONIC ACID PREVENT THE GERMINATION

    ÇAVUŞOĞLU, Kürşat

    2009-01-01

    Abstract: Effect of jasmonic acid on seed germination and seedling growth of barley (Hordeum vulgare L. cv. Bülbül 89) was investigated in the present study. Jasmonic acid concentrations less than 1500 µM have not inhibited the seed germination, while 1500 and 2000 µM jasmonic acid levels caused atypical germination. The germination was completely inhibited at 3000 µM level of jasmonic acid. However, the seedling growth clearly slowed down with increasing concentrations of jasmonic acid. Furt...

  14. The Specifications for Monitoring of Acid Rain

    Tang Jie

    2011-01-01

    Background Since China is a country seriously affected by acid rain pollution,it is a long-term fundamental work for acid rain pollution prevention and control in China by getting well informed of the characteristics of spatial and temporal changes in acid rain and long-term trends of these changes.In order to reach the national demand for acid rain monitoring data,the China Meteorological Administration (CMA) began to construct the network of acid rain monitoring stations in 1992.By the end of 2010,the total number of monitoring stations has exceeded 340.

  15. Lactobionic and cellobionic acid production profiles of the resting cells of acetic acid bacteria.

    Kiryu, Takaaki; Kiso, Taro; Nakano, Hirofumi; Murakami, Hiromi

    2015-01-01

    Lactobionic acid was produced by acetic acid bacteria to oxidize lactose. Gluconobacter spp. and Gluconacetobacter spp. showed higher lactose-oxidizing activities than Acetobacter spp. Gluconobacter frateurii NBRC3285 produced the highest amount of lactobionic acid per cell, among the strains tested. This bacterium assimilated neither lactose nor lactobionic acid. At high lactose concentration (30%), resting cells of the bacterium showed sufficient oxidizing activity for efficient production of lactobionic acid. These properties may contribute to industrial production of lactobionic acid by the bacterium. The bacterium showed higher oxidizing activity on cellobiose than that on lactose and produced cellobionic acid. PMID:25965080

  16. Study of Synthesis of Copoly (lactic acid/glycolic acid) by Direct Melt Polycondensation

    LAN Ping; GAO Qin-wei; SHAO Hui-li; HU Xue-chao

    2005-01-01

    A two steps direct copolymerisation process was developed. The first step is to produce oligomer and then the oligomer of lactic acid/glycolic acid (90/10) is polymerized with binary catalyst tin chloride dihydrate/ptoluenesulfonic acid. In this way, the direct synthesis of copoly (lactic acid/glycolic acid) without any organic solvent was investigated. The properties and structures of products were characterized by nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), X-ray diffraction and so on. The results show that comparatively high molecular weight copolymer of lactic acid and glycolic acid can be prepared by direct processing under appropriate technological conditions.

  17. Evolution of retinoic acid receptors and retinoic acid signaling.

    Gutierrez-Mazariegos, Juliana; Schubert, Michael; Laudet, Vincent

    2014-01-01

    Retinoic acid (RA) is a vitamin A-derived morphogen controlling important developmental processes in vertebrates, and more generally in chordates, including axial patterning and tissue formation and differentiation. In the embryo, endogenous RA levels are controlled by RA synthesizing and degrading enzymes and the RA signal is transduced by two retinoid receptors: the retinoic acid receptor (RAR) and the retinoid X receptor (RXR). Both RAR and RXR are members of the nuclear receptor superfamily of ligand-activated transcription factors and mainly act as heterodimers to activate the transcription of target genes in the presence of their ligand, all-trans RA. This signaling pathway was long thought to be a chordate innovation, however, recent findings of gene homologs involved in RA signaling in the genomes of a wide variety of non-chordate animals, including ambulacrarians (sea urchins and acorn worms) and lophotrochozoans (annelids and mollusks), challenged this traditional view and suggested that the RA signaling pathway might have a more ancient evolutionary origin than previously thought. In this chapter, we discuss the evolutionary history of the RA signaling pathway, and more particularly of the RARs, which might have experienced independent gene losses and duplications in different animal lineages. In sum, the available data reveal novel insights into the origin of the RA signaling pathway as well as into the evolutionary history of the RARs. PMID:24962881

  18. Composition of acid tars from sulfuric acid treatment of petroleum oils

    Frolov, A.F.; Denisova, T.L.; Karpova, I.V.; Titova, T.S.

    1986-01-01

    This paper examines the composition of freshly produced acid tars and pond tars, gives an analysis of the acid part of the tars, and obtains data on the change in composition of the acid tar in the course of storage--data that are needed in developing methods for utilizing the tar. The acid-pond tars consist of a mixture of hydrocarbons with a very low content of acids, whereas the freshly produced acid tars consist mainly of sulfuric acid, sulfonic acids, and carboxylic acids. In the course of storage, hardening of acid tars in the volume proceeds through reactions of polymerization, condensation, and oxidation of the surface layer that is in contact with air.

  19. CLIMATE CHANGE ADAPTATION IN ACID SULFATE LANDSCAPES

    Chuxia Lin

    2012-01-01

    Full Text Available Oxidation of sulfide minerals produces sulfuric acid and consequently creates Acid Sulfate Landscapes (ASLs, which represent one of the most degraded types of land-surface environments. Although acid sulfate-producing weathering is a naturally occurring process, it is markedly facilitated by human intervention. Mining is by far the dominant anthropogenic cause for the creation of inland acid sulfate footprints while land reclamation in coastal lowlands is the driver for the formation of coastal ASLs. The projected climate change highlights the possibility of an increase in the frequency and severity of extreme weather events such as droughts and heavy rains, which is likely to accelerate the acid generation in some circumstances and increase the frequency and magnitude of acid discharge. Sea level rise as a result of global warming will cause additional problems with the coastal ASLs. This is a review article. The following aspects are covered: (a the overriding biogeochemical processes leading to acid sulfate-producing weathering, (b a brief introduction to the inland acid sulfate landscapes, (c a brief introduction to the coastal acid sulfate landscapes, (d the likely impacts of climate change on ASLs and (e the possible measures to combat climate change-induced environmental degradation in the identified key acid sulfate footprints. The projected climate change is like to significantly affect the acid sulfate landscapes in different ways. Appropriate management strategies and cost-effective technologies need to be developed in order to minimize the climate change-induced ecological degradation.

  20. Amino acid properties conserved in molecular evolution.

    Witold R Rudnicki

    Full Text Available That amino acid properties are responsible for the way protein molecules evolve is natural and is also reasonably well supported both by the structure of the genetic code and, to a large extent, by the experimental measures of the amino acid similarity. Nevertheless, there remains a significant gap between observed similarity matrices and their reconstructions from amino acid properties. Therefore, we introduce a simple theoretical model of amino acid similarity matrices, which allows splitting the matrix into two parts - one that depends only on mutabilities of amino acids and another that depends on pairwise similarities between them. Then the new synthetic amino acid properties are derived from the pairwise similarities and used to reconstruct similarity matrices covering a wide range of information entropies. Our model allows us to explain up to 94% of the variability in the BLOSUM family of the amino acids similarity matrices in terms of amino acid properties. The new properties derived from amino acid similarity matrices correlate highly with properties known to be important for molecular evolution such as hydrophobicity, size, shape and charge of amino acids. This result closes the gap in our understanding of the influence of amino acids on evolution at the molecular level. The methods were applied to the single family of similarity matrices used often in general sequence homology searches, but it is general and can be used also for more specific matrices. The new synthetic properties can be used in analyzes of protein sequences in various biological applications.